1. No category

program
MS Research Days 2015
May 28 - 29, 2015 • CORPUS, Oegstgeest
MS Research in past, present and future
What’s in it for patients?
content
Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Short program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Instructions speed dates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Complete program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Keynote Speakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Abstracts sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Poster overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Abstracts posters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
1
A warm welcome
On behalf of all colleagues involved with our foundation I’d like to wish you a
very warm welcome at the MS Research Days 2015.
This time a special touch is added by the start of the Foundation’s 35th
anniversary.
Together with you, we are looking forward to an inspiring program; last year
results will be shared and future views will be discussed. Also there will be
great keynote speakers, surprising presentations, debates, guest speakers, speed dating
sessions and much more. We hope that these MS Research Days will fulfill your expectations.
Afterwards we are looking forward to your feedback, so in 2016, we can serve you and the
research to MS even better.
Special thanks to Jeroen Geurts, Jan Meilof and Annette van der Goes, who have made
many extra efforts to compose these days.
And of course our thanks as well to all others who have contributed to the establishment
of these days.
Dorinda Roos
CEO Dutch MS Research Foundation
2
Introduction
Dear colleagues,
A warm welcome to the MS Research Days 2015!
As the Dutch MS Research Foundation celebrates its 35th anniversary, we
focus this year on past, present and future MS research and more particularly
on what patients have gained by 35 years of research.
Undeniably, we have learned a lot about MS as a disease in recent decades.
Different abnormalities in white and grey matter have been characterized
and MS is no longer considered a ‘typical white matter disease’. Various
hypotheses concerning its origin circulate and are currently under study. Also,
major steps have been made in making a diagnosis early in the course of the
disease. And finally, in the past 20 years, the choice and number of therapies
has been importantly increased. In short, we have seen, and are still seeing,
tremendous progress in the field. And that makes MS research both fascinating and rewarding.
We hope that the program for the MS Research Days 2015 will give new
impetus to MS research. It contains three keynote lectures, nine scientific
sessions and a hot topic session. We are fortunate that nine principal investigators were
willing to chair a session; they proposed the line-up of researchers within their own
session. As a fixed element, presenters have been asked to end their presentation with
a statement regarding the significance of their work for other researchers and especially
for patients with MS. The special Hot Topic session will focus on cognition in MS: from
molecules and images towards cognitive interventions.
In the first keynote lecture you will be taken on a short journey through time across the
main results in MS research from the past 35 years. The second keynote, on Friday morning, will point out current and upcoming treatment options for people with MS and especially new research opportunities associated with these treatments. The third keynote will
illustrate the dynamics of science policy discussions in the Netherlands and will explore
opportunities for young researchers looking for a career in science in the (near) future.
We all know why MS research is necessary. However, to provide you with a sense of what
MS actually means for people experiencing the disease, we would like to draw your attention to Dit is mijn leven, a film presented on Thursday afternoon.
Two new parts of the program are the MS-interactief and the MS speed dates. We hope
that these new ways of discussing research will spark new insights and promote new
collaborations within the MS research field.
MS research in past, present and future. What’s in it for patients? On behalf of the Scientific Advisory Board of the Dutch MS Research Foundation, we wish you enlightening
Research Days.
Jeroen Geurts and Jan Meilof,
Scientific Committee MS Research Days
3
Location
Corpus, Oegstgeest
Directions by car
CORPUS is located on the A44 motorway in Oegstgeest. Our address is Willem Einthoven­
straat 1, 2342 BH Oegstgeest. However, the Willem Einthovenstraat is not recognized
by all navigation systems. If your system does not recognize this street, use the following
address: Ingenieur G. Tjalmaweg, Leiden. When you arrive here, you will already be able
to see the CORPUS building.
From the A44 coming from Amsterdam
Exit for Leiden, nr 8.
At the traffic lights turn right towards Katwijk.
Then take the first road for CORPUS.
From the A44 coming from The Hague/Wassenaar
Exit for Leiden, nr 8.
At the traffic lights turn left towards Katwijk.
Go under the viaduct and straight on.
The first road immediately after the crossroads is for CORPUS.
From the N11 coming from Utrecht/Bodegraven
Take the A4 heading towards The Hague. Take the first exit on the A4 for Leiden/Zoeterwoude (exit nr 7). Drive towards Leiden via the N206 heading to Katwijk.
After about 3.5 km go under the viaduct of the A44 and straight on.
The first road immediately after the crossroads is for CORPUS.
4
Location
Directions by public transport
CORPUS is located on the A44 motorway in Oegstgeest. Our address is Willem Einthovenstraat 1, 2342 BH Oegstgeest. CORPUS is easy to reach by public transport. Below you
will find some suggested routes.
From Leiden CS, option 1
From the south side of the Central Station (bus station and centre) you can take bus 38
or 33 (for Katwijk ZH) or bus 35 (for Katwijk ZH). Get off at the Transferium A44. This
bus stop is located in the Ingenieur G. Tjalmaweg. From here, it is approximately a 7 minute walk to CORPUS. From the bus stop, follow the bicycle signs which show the route of
the path (red dotted line on the map) which runs alongside the A44 motorway towards the
CORPUS building which is located along this motorway.
From Leiden CS, option 2
From the north side of the Central Station (LUMC stop), you can take bus 57 (for Lisse/
Hoofddorp). Get off at the stop for CORPUS, which is located at the end of the Wassenaarseweg before it becomes the Endegeesterstraatweg after the bend to the right. From
the stop for CORPUS, you walk under the viaduct of the A44 to the CORPUS building.
From Leiden CS, option 3
From the south side of the Central Station (bus station and centre) you can take bus
43 (for The Hague). Get off at the stop for Universiteitsterrein (university campus) and
take the Einsteinweg in the direction of the A44. At the end of the Einsteinweg, turn right
into the Niels Borhweg and continue until you reach the Wassenaarseweg. Then turn left
and walk under the viaduct of the A44 to the CORPUS building.
From The Hague CS
From the Central Station bus platform, you can take the Qliner 386 (for Oegstgeest) or Qliner 385 (for Noordwijk). Get off at theTransferium A44. This bus stop is
located in the Ingenieur G. Tjalmaweg. From here, it is approximately a 7 minute walk to
CORPUS. From the bus stop, follow the bicycle signs which show the route of the path
which runs alongside the A44 motorway towards the CORPUS building which is located
along this motorway.
From Oegstgeest
Take bus 57 for Leiden and get off at the stop for CORPUS. From this stop, you walk
under the viaduct of the A44 to the CORPUS building.
5
Short program MS Research Days 2015
MS research in past, present and future. What’s in it for patients?
Corpus, Oegstgeest, Conference room
Hosts
prof.dr. Jeroen Geurts and dr. Jan Meilof
Thursday, 28 May 2015
Time
09.00
Registration and Coffee
09.30
Opening
prof.dr. Jeroen Geurts en dr. Jan Meilof
09.35
Keynote 1
prof.dr. Frederik Barkhof
35 years of MS research
10.20
Session 1
What drives the T- and B-cells in the CNS?
Chair: prof.dr. Rogier Hintzen
11.05
11.30
Break
MSinteractief
12.30
Lunch and poster viewing
13.30
Speed dates
Speed dates for PhD students and post-docs
Chair: dr. Wia Baron
14.15
Session 2
From microglia to lymphocyte
Chair: prof.dr. Jon Laman
15.00
Session 3
Microglia: how the brain talks back to the immune system
Chair: dr. Jeffrey Bajramovic
15.45
MS-biopic
Tessa
Dit is mijn leven
16.00
6
Toekomst van MS-onderzoek
Moderator: Peter van der Geer
Break
16.15
Session 4*
Inflammation at the barriers of the central nervous system in MS
Chair: prof.dr. Elga de Vries
17.00
Session 5*
Progressive MS Alliance
Chair: Ceri Angood Napier
18.00
Drinks
19.00
Dinner
22.30
End
*session in Breakout room
Short program MS Research Days 2015
Friday, 29 May 2015
08.30
Welcome and coffee
09.00
Session 6
Remyelination in MS: from basic science to therapy?
Chair: dr. Wia Baron
09.45
Keynote 2
dr. Joep Killestein
Therapies now and in the future
10.30
Break
11.00
Session 7
Imaging
Chair: dr.ir. Hugo Vrenken
11.45
Hot topic
Cognition in MS: from molecules and imaging towards cognitive
interventions
Chair: prof.dr. Jeroen Geurts
12.15
Lunch
12.45
Session 8
Latest insights from UHasselt
Chair: prof.dr. Jack van Horssen
13.30
Session 9
Grey Matter tissue in MS
Chair: dr. Inge Huitinga
14.15
Keynote 3
dr. Barend van der Meulen
Future science and opportunities for PhD students
15.00
MS-overseas
dr. Tessel Runia
Travel grant
15.15
Speed dates
Presentations of the nominees
15.45
Awards and closing
16.00
End
7
Instructions for MS speed date session
The speed dates are meant for young MS researchers (PhD students and post-docs) to
stimulate the collaborations between the different institutes and within the different
disciplines. Every participant has three speed dates and will write a short research proposal with the best match speed date partner. Only PhD students and post-docs that are
present on both the Thursday and the Friday can take part.
Program
Thursday 1.30 – 2.15 pm: Speed dates
Wia Baron will give a short introduction. Subsequently, every participant has 3 speed
dates of each 10 minutes. After 10 minutes the horn will give the signal that you can
go to your next speed date. Together with your speed date partner you will discuss which
research you are doing and whether you can come up with a joint research proposal.
Thursday until Friday 9 am: write research proposal
With the speed date partner you have the best match, you will write a short research
proposal. For this you use the MS-speed date form, that you can fill in with pen. Remember to hand in your proposal by 9 am on Friday morning in the box at the registration desk
(one copy).
Friday 12.15 pm: announcement nominees
Nominated 3 speed date couples will be announced.
Friday 3.15 pm: presentations nominees
The 3 nominated speed date couples will have 5 minutes per couple to present their
research proposal (elevator pitch, no slides, flip-over is available).
Friday 3.30: award ceremony
The speed date couple with the best research proposal and presentation will be rewarded
with a gift voucher of 150 euro per person.
Guidelines
- Only one research proposal per person;
- A multidisciplinary approach is preferred;
- Feasibility should be taken into account.
The jury consists of
- Wia Baron (chair)
- Jeffrey Bajramovic
- Anne-Marie van Dam
8
Complete program MS Research Days 2015
MS research in past, present and future. What’s in it for patients?
Corpus, Oegstgeest, Conference room
Hosts
prof.dr. Jeroen Geurts and dr. Jan Meilof
Thursday, 28 May 2015
Time
09.00
Registration and Coffee
09.30
Opening
prof.dr. Jeroen Geurts en dr. Jan Meilof
09.35
Keynote 1
p14
35 years of MS research
prof.dr. Frederik Barkhof
10.20
Session 1
p17
What drives the T- and B-cells in the CNS?
Chair: prof.dr. Rogier Hintzen
Identification of novel mechanisms controlling peripheral T-cell
activation in MS
Marvin van Luijn (ErasMS)
Local T-cell responses in MS
Gijsbert van Nierop (ErasMS)
11.05
Break
11.30
MS-interactief##
Toekomst van MS-onderzoek
Moderator: Peter van der Geer
Thema’s:
1. Is MS een immunologisch of neurodegeneratief probleem?
2. Patiënten moeten kunnen mee beslissen over het onderzoek
dat gefinancierd wordt?
3. Is RRMS een controleerbare ziekte?
4. Thema n.a.v. een peiling onder de deelnemers
12.30
Poster overview
from p57
Lunch and poster viewing
13.30
Speed dates
Speed dates for PhD students and post-docs
Peter van der Geer, gespreksleider (Debat.nl)
Marc van Bijsterveldt, wetenschapsjournalist
##
9
Complete program MS Research Days 2015
14.15
Session 2
p20
From microglia to lymphocyte
Chair: prof.dr. Jon Laman
Peripheral inflammation alters microglia function
Bart Eggen (UMCG)
The later stages of mouse EAE, a role for microglia
Ilia Vainchtein (UMCG)
Dichotomous outcome of IL-7 receptor (CD127) blockade in
non-human primate experimental autoimmune encephalomyelitis
Jordon Dunham (EMC)
15.00
Session 3
p24
Microglia: how the brain talks back to the immune system
Chair: dr. Jeffrey Bajramovic
Genome-wide approaches to study (micro) glia in health and
disease: 1) Glia Open Access Database (GOAD; www.goad.education) and 2) a co-expression meta-analysis of primed microglia
Inge Holtman (UMCG)
Innate immune activation in macrophages and microglia
Saskia Burm (BPRC)
Microglia show an intermediate activation status in early lesion
formationin multiple sclerosis
Laura Peferoen (VUmc)
15.45
MS-biopic
16.00
16.15
Dit is mijn leven
Tessa
Break
Session 4*
p28
Inflammation at the barriers of the central nervous system in MS
Chair: prof.dr. Elga de Vries
The role of the choroid plexus in MS
Gijs Kooij (VUmc)
Relation between LXR activation and blood-brain barrier function
during neuroinflammation in multiple sclerosis
Jasmine Vanmol (UHasselt)
Molecular regulation of the blood-brain barrier phenotype
Claudio Derada Troletti (VUmc)
10
*session in Breakout room
Complete program MS Research Days 2015
17.00
Session 5*
p32
Progressive MS Alliance
Chair: Ceri Angood Napier (MSIF, UK)
Immune-primed microglia: a factor underlying progressive
­multiple sclerosis
Sandra Amor (VUmc)
Inflammation drives mitochondrial dysfunction and associated
neurodegeneration in multiple sclerosis
Philip Nijland (VUmc)
Discovery of biomarkers reflecting progression pathophysiology
for primary progressive MS subtype by applying next generation
sequencing and novel multiplex aptamer approach
Arjan Malekzadeh (VUmc)
Towards a shared data repository to enhance the standards of
rehabilitation in MS: feasibility, capacity building and proof-ofconcept on exercise therapy & mobility measures
Peter Feys (UHasselt)
18.00
Drinks
19.00
Dinner
An award ceremony and a special cabaret act will be part of the
program. The evening will be musically entertained by “A night
like this”.
Besides participants of the MS Research Days 2015, the
Scientific Advisory Board, Board members and colleagues of the
Dutch MS Research Foundation, people with MS, donors and
many others will be present.
11
Complete program MS Research Days 2015
friday, 29 May 2015
08.30
09.00
Welcome and coffee
Session 6
p36
Remyelination in MS: from basic science to therapy?
Chair: dr. Wia Baron
Nrf2 activators: a novel strategy to promote oligodendrocyte
survival in multiple sclerosis?
Jamie Lim (VUmc)
Distinct modulation of myelination efficiency by cortical and
non-cortical astrocytes
Inge Werkman (UMCG)
Functionality of human induced pluripotent stem cell-derived
oligodendrocytes in an MS primate model
Arun Thiruvalluvan (UMCG)
09.45
Keynote 2
p15
Therapies now and in the future
dr. Joep Killestein
Session 7
p41
Imaging
Chair: dr.ir. Hugo Vrenken
10.30
11.00
Break
Understanding the relation of gray matter atrophy patterns in
multiple sclerosis with other MS pathology
Martijn Steenwijk (VUmc)
Timing of retinal neuronal and axonal loss in MS; a longitudinal
OCT study
Lisanne Balk (VUmc)
Longitudinal monitoring of microglia activation and CNS myelin
with [11C]PK11195 and [11C]MEDAS PET imaging in the
cuprizone mouse model for Multiple Sclerosis
Ate Boerema (UMCG)
11.45
Hot topic
p53
Cognition in MS: from molecules and imaging towards cognitive
interventions
Chair: prof.dr. Jeroen Geurts
Understanding cognitive impairment in MS – brain imaging and
histopathology
Menno Schoonheim (VUmc) & Geert Schenk (VUmc)
Treating cognitive impairment in MS – how to move forward?
Neeltje Kant (Nieuw Unicum) & Hanneke Hulst (VUmc)
12.15
12
Lunch
Complete program MS Research Days 2015
12.45
Session 8
p47
Latest insights from UHasselt
Chair: prof.dr. Jack van Horssen
Disturbed skeletal muscle cell biochemistry and composition in
multiple sclerosis
Inez Wens (UHasselt)
Does CMV trigger CD4+CD28null T-cell expansion in the context
of MS?
Marjan Vanheusden (UHasselt)
The role of LXRb in neuroinflammation
Tim Vanmierlo (UHasselt)
13.30
Session 9
p50
Grey Matter tissue in MS
Chair: dr. Inge Huitinga
Experimental demyelination causes neuronal hyperexcitability
Maarten Kole (NIN)
Complement C1q-C3 associated synaptic changes in multiple
sclerosis hippocampus
Valeria Ramaglia (NIN)
14.15
Keynote 3
p16
Future science and opportunities for PhD students
dr. Barend van der Meulen (Rathenau Instituut)
15.00
MS-overseas
Travel grant
dr. Tessel Runia
15.15
Speed dates
Presentations of the nominees
15.45
Awards and closing
13
Keynote 1
Frederik Barkhof
Frederik Barkhof received his MD from VU University, Amsterdam, the
Netherlands in 1988 and defended his PhD thesis in 1992, for which he
received the Philips Prize for Radiology in 1992 and the Lucien Appel Prize
for Neuroradiology in 1994. Since 2001 he serves as a full Professor in
Neuroradiology at the department of Radiology & Nuclear Medicine at the
VU University Medical Center (VUmc). He is a senior staff member of the MS
Center Amsterdam, and senior consultant of the Alzheimer Center, VUmc.
He is the Scientific Director of the Image Analysis Centre (IAC), involved in analysis of
multicentre drug trials. Prof. Barkhof was the chairman of the Dutch Society of Neuroradiology and the MAGNIMS study group for many years. He serves on the Editorial boards
of Radiology, Brain, European Radiology (section editor for Neuroradiology), Multiple
Sclerosis Journal, Neuroradiology and Neurology.
Prof. Barkhof’s research interests focus on childhood white matter disease, on multiple
sclerosis (spinal cord MRI, grey matter, atrophy, histopathology correlations), on ageing
(white matter lesions and microbleeds) and dementia (hippocampal atrophy in Alzheimer
and functional MR). He (co)authored >750 papers referenced in PubMed, has an H-factor
of 86 and is author of the books “Neuroimaging in Dementia” and “Clinical applications
of functional brain MRI”.
Cumulatively, he has received >10 million euro grant money from various national and
international funding agencies and performed contract research for all major pharmaceutical companies with cumulative contract value of > 15 million euro. More than 30 PhD
students graduated under his supervision and 2 of them have subsequently attained a full
professorship.
In his keynote lecture at the MS Research Days, he will take you on a short journey
through time along the main MS results in MS research from the past 35 years. During
this period the diagnosis of MS has been revolutionized by the advent of MRI while many
new treatments have been introduced that are increasingly effective.
Some selected publications
1. Barkhof F, Ciccarelli O. Daclizumab in multiple sclerosis: a high-yield extension study.
Lancet Neurol. 2014 May;13(5):443-4.
2. Barkhof, F. & Wattjes, M.P. (2013). Multiple sclerosis: CCSVI deconstructed and discarded. Nature Reviews Neurology, 9, 661-662.
3. Barkhof F, Calabresi PA, Miller DH, Reingold SC. Imaging outcomes for neuroprotection and repair in multiple sclerosis trials. Nat Rev Neurol. 2009 May;5(5):256-66
4. Geurts JJ, Barkhof F. Grey matter pathology in multiple sclerosis. Lancet Neurol.
2008;7(9):841-51
5. Jasperse B, Vrenken H, Sanz-Arigita E, de Groot V, Smith SM, Polman CH, Barkhof F.
Regional brain atrophy development is related to specific aspects of clinical dysfunction in multiple sclerosis. Neuroimage. 2007 Nov 15;38(3):529-37
14
Keynote 2
Joep Killestein
Joep Killestein, MD, PhD, is a Staff Neurologist at Vrije Universiteit University Medical Centre and the MS Centre Amsterdam since 2006. He completed
his PhD training on T-cell functions in treated and untreated MS patients in
2002. The main focus of his current research is on the correlation between
biomarkers and response to disease modifying therapies in MS, e.g. the
response to interferon-beta (IFNb), fingolimod and natalizumab, including
immunogenicity issues. Another important domain of his work comprises
complications of therapy like natalizumab-associated progressive multifocal leukoencephalopathy (PML). He has been involved in several clinical trials in Multiple Sclerosis,
including those testing safety and efficacy of IFNb, T and B cell depletion, natalizumab,
cladribine, dimethylfumarate, laquinimod, fingolimod, vitamin D and cannabinoids.
Dr Killestein is a member of the European Committee for Treatment and Research in MS
(ECTRIMS) council, the Medical Ethics Review Committee of VUmc, company advisory
boards, trial steering committees and adjudication committees. He is program leader of
the research program ‘Neuroinflammation’ of the Neuroscience Campus Amsterdam. A
member of the CBO committee which developed treatment guidelines for MS in the Netherlands and a board member of the MS taskforce of the Netherlands Society of Neurology.
In his keynote lecture at the MS Research Days he will talk about the current and upcoming treatment options for people with MS, hopes and hazards. He will focus especially on
new research opportunities associated with response to these treatments, personalized
medicine and pharmacovigilance.
Some selected publications
1. Vennegoor A, van Rossum JA, Polman CH, Wattjes MP, Killestein J. Longitudinal JCV
serology in multiple sclerosis patients preceding natalizumab-associated progressive
multifocal leukoencephalopathy. Mult Scler. 2015 [Epub ahead of print]
2. van Oosten BW, Killestein J, Barkhof F, Polman CH, Wattjes MP. PML in a patient
treated with dimethyl fumarate from a compounding pharmacy. N Engl J Med. 2013
Apr 25;368(17):1658-9.
3. Vennegoor A, Rispens T, Strijbis EM, Seewann A, Uitdehaag BM, Balk LJ, Barkhof F,
Polman CH, Wolbink G, Killestein J. Clinical relevance of serum natalizumab concentration and anti-natalizumab antibodies in multiple sclerosis. Mult Scler. 2013
Apr;19(5):593-600.
4. Killestein J, Rudick RA, Polman CH.Oral treatment for multiple sclerosis. Lancet Neurol. 2011 Nov;10(11):1026-34.
5. Killestein J, Polman CH. Determinants of interferon b efficacy in patients with multiple
sclerosis. Nat Rev Neurol. 2011 Apr;7(4):221-8.
15
Keynote 3
Barend van der Meulen
Barend van der Meulen is head of the dept Science System Assessment of
the Rathenau Instituut. The Rathenau Instituut is an institute of the Netherlands Royal Academy of Arts and Sciences (KNAW), with a mission to support policy making and public debate on issues of science and technology.
Barend van der Meulen has a long time experience in science policy studies
on the interaction between policy making and the dynamics of the research
system, on science policy instruments, dynamics of research organisations
and evaluation of research.
In his key note he will assess the issue of the future PhD education at universities, given
the changes in labour markets for higher educated and development of academic careers.
He will assess such issues against the backdrop of scenarios for the Dutch universities
and the national research system more general. These scenarios are a result of a joint
project of Rathenau Instituut and the Association of Dutch Universities. Universities are
facing three key uncertainties for future strategies. First of all whether scientific knowledge is considered a private or a public good. Second, whether critically resources are
rather certain or have to be earned on a (hyper)competitive market and thirdly, what the
geographical space is in which they operate. Strategic options are different for each of the
scenario’s.
Some selected publications
1. Vizier Vooruit, 4 toekomstscenario’s voor Nederlandse universiteiten. Rathenau Instituut 2013
2. Talent Centraal, Ontwikkeling en selectie van wetenschappers in Nederland. Rathenau
Instituut 2013
3. Valuable-indicators for valoriation. Rathenau Instituut 2013
16
Session 1
What drives the T- and B-cells in the CNS?
Chair: prof.dr. Rogier Q. Hintzen
Department of Neurology, MS Center ErasMS, Erasmus MC, Rotterdam, The Netherlands
Abstract
We are currently in the peculiar situation that the only medications that work in MS are
drugs that interact with activated T and B cells. But what we don’t know is what signals
are responsible for activation of these adaptive immune cells in MS. This may be due
to direct recognition of auto antigens or via infection induced bystander effects, super
antigens or mimicry. Evidence will be discussed as to why research on the background of
the antigen specific stimulation deserves more attention.
Marvin van Luijn
Identification of novel mechanisms controlling peripheral T-cell activation in MS
Authors Marvin M. van Luijn1, Liza Rijvers1, Roos M. van der Vuurst-de Vries2, Jeanet
Hogervorst1, Malou Janssen2, Annet F. Wierenga-Wolf1, Marie-José Melief1,
Jon D. Laman2 and Rogier Q. Hintzen2
Affiliation 1Department of Immunology, MS Center ErasMS, Erasmus MC, Rotterdam
2
Department of Neurology, MS Center ErasMS, Erasmus MC, Rotterdam
Abstract
BACKGROUND+OBJECTIVE: A central dogma in MS pathogenesis is that autoreactive T
cells are activated in the periphery to mediate inflammatory events in the CNS. Although
HLA, non-HLA genetic risk factors and EBV are considered to play critical roles in T-cell
activation, exact underlying mechanisms remain poorly understood. We see a central role
for the B-cell as a key antigen presenting cell in MS pathogenesis. Our aim is to specify if
and how some novel genetic MS risk factors functionally link to the interactive pathways
between antigen-presentation (APC) and T-cell activation. Some main topics: 1) genetic
influence on HLA-II antigen presentation (with a specific focus on B cells), 2) EBV and
B-cell immune escape, and 3) functional phenotyping of B- and T-cell subsets during MS
disease course, and the association with MS risk alleles.
METHODS: Novel genes coming from MS genome-wide association studies show direct
links to the function of the major MS genetic factor, HLA-II. We use different human
APC models (i.e. melanoma cells, primary monocyte-derived dendritic cells and B cells)
to silence these genes and assess their role in HLA-II biology using RNAi and high-resolution microscopy. Additionally, 12-13 color flow cytometry and high-speed cell sorting
equipment is used to assess functional markers and isolate B- and T-cell blood subsets of
several cohorts of MS cases and healthy controls. We also take advantage of the in-house
designed molecular assays to explore antigen- or EBV-driven maturation of sorted B-cell
subsets (e.g. KREC assay, EBV qPCR).
17
RESULTS: Previously, we showed that of the candidate risk genes, CLEC16A, is upregulated in MS and is a key regulator of endosomal formation to control HLA-II expression in
monocyte-derived dendritic cells. Our current research on the function of such risk genes
in the HLA-II pathway zooms in on B cells, for which increased HLA-II surface expression
was found on different subsets in MS. Differential EBV loads receptor expression in sorted
B-cell subsets indicate a selective role of EBV in B cell development in MS. An interim
finding in our study on functional T-cell markers and subsets is the strongly reduced
frequency of highly activated effector Th1/17 (CXCR3+CCR6+) and for example not Th17
(CXCR3-CCR6+) in MS compared to control blood. These Th1/17 frequencies correlate
with the time of CIS to MS conversion.
CONCLUSIONS: This ongoing work provides evidence that the function of peripheral B
and T cells is selectively regulated in MS. The reduced frequency of activated Th1/17
cells in MS blood implicate either differences in Th skewing, or their preferential migration to the CNS. We argue that HLA genetics and EBV integrate to selectively control B-T
cell interaction, leading to impaired peripheral tolerance checkpoints in MS.
Gijsbert van Nierop
Local T-cell responses in MS
Authors Gijsbert P. van Nierop1,2, Josef Mautner3, Malou Janssen1, Johanna G.
­Mitterreiter2,4, Rik L de Swart2, Bart L Haagmans2, Albert D.M.E. Osterhaus2,
Georges M.G.M. Verjans1,4 and Rogier Q. Hintzen1
1
Affiliation MS centre ErasMS at the department of Neurology of the Erasmus MC, Rotterdam, the Netherlands
2
Department of Viroscience at the Erasmus MC, Rotterdam, the Netherlands
3
Helmholtz Zentrum München & Technical University, Munich, Germany
4
Research Center for Emerging Infections and Zoonosis, University of Veteri
nary Medicine, Hannover, Germany
Abstract
BACKGROUND+OBJECTIVE: There is reason to believe that local intrathecal antigen
recognition is instrumental in MS neuropathology. There are indirect signs of an aberrant
response either auto- or foreign antigens (such as EBV), but the exact triggers remain
to be elucidated. This project aims to study function, phenotype and fine specificity of
locally derived intrathecal T cells, from cerebrospinal fluid (CSF) of early MS patients and
controls or from post-mortem MS-tissues.
METHODS: For early MS, CSF-derived T-cell lines (TCL) were generated by mitogenic
stimulation from 29 MS and 13 other neurological disease (OND) patients. For chronically progressed MS, paired post-mortem tissues including MS lesion, normal appearing
18
white matter (NAWM) and CSF were obtained. Tissues were partly snap-frozen for in situ
analysis and partly dispersed for T-cell phenotyping using flow cytometry and generation
of TCL. CSF and tissue-derived TCL were analysed for clonal enrichment and antigen
specificity. From blood, EBV-transformed B-cells (BLCL) were generated and used as
autologous antigen presenting cell (APC) to simultaneously determine the frequency of
EBV-specific CD4 and CD8 T-cells. Next, cognate CD8 T-cell antigens were identified
using HLA-I negative monkey cells as artificial APC co-transfected with individual EBV
antigens and the corresponding patient’s HLA-I alleles involved in T-cell reactivity. BLCL
were stably transduced using a novel vector system for endogenous expression of eight
MS-associated antigens (MSAg) used as APC in co-culture experiments.
RESULTS: Early MS patients show an elevated oligoclonal BLCL-specific CD4 and CD8
T-cells response in CSF directed to lytic EBV antigens. No reactivity to MSAg is detected.
In situ analysis of end stage MS lesions reveals extravasated T-cells, mainly CD8, expressing Ki67 and granzyme B, indicating local proliferation of antigen-experienced T-cells.
Flow cytometric analysis shows a similar, mainly effector memory T-cell phenotype in MS
lesions and NAWM but with distinct oligoclonal T-cell receptor Vß repertoires. BLCL-reactive T-cells are selectively detected in lesions of 2/7 MS patients.
CONCLUSIONS: Enhanced intrathecal BLCL-specific T-cell reactivity, selectively directed
towards lytic EBV proteins in CSF-TCL, suggest a local T-cell response to EBV early in MS.
Inability to detect T-cells specific for eight MSAg questions their role as prominent target
antigens in MS. Selective retention of BLCL-reactive CD8 T-cells in MS lesions indicate
involvement of EBV-specific T-cells in at least part of the MS patients.
19
Session 2
From microglia to lymphocyte
Chair: prof.dr. Jon laman
Dept. of Neuroscience, section Medical Physiology, University of Groningen, University
Medical Center Groningen, Groningen, The Netherlands
Bart Eggen
Peripheral inflammation alters microglia function
Authors Wandert Schaafsma, Xiaoming Zhang, Erik Boddeke, Bart Eggen
Affiliation Dept. of Neuroscience, section Medical Physiology, University of Groningen,
University Medical Center Groningen, Groningen, The Netherlands
Abstract
BACKGROUND+OBJECTIVE: Microglia are the innate immune cells of the CNS involved
in homeostasis maintenance. Microglia activation has been observed in a variety of neurodegenerative diseases, including Multiple Sclerosis, Alzheimer’s Disease and Amyotrophic
Lateral Sclerosis. The aim of this study was to determine if peripheral inflammation
altered microglia function and microglia activation in response to subsequent challenges.
METHODS: Microglia were stimulated by lipopolysaccharides (LPS) and other TLR
ligands, and the effect on microglia activation and function was determined in vitro
and in vivo. Epigenetic changes in microglia were determined using chromatin immune
precipitation experiments. Microglia function was assessed in view of cytokine secretion,
electrophysiological parameters, and phagocytic activity.
RESULTS: A single inflammatory insult by LPS resulted in a suppressed pro-inflammatory
microglia phenotype. This reduced responsiveness to subsequent LPS challenges was persistent and accompanied by epigenetic silencing of inflammatory genes. LPS-challenged
microglia displayed enhanced phagocytic activity and reduced inflammatory cytokine
secretion after additional challenges.
CONCLUSIONS: Microglia activation can be altered by a single peripheral inflammatory
challenge, and result in long-term changes in microglia function.
20
Ilia Vainchtein
The later stages of mouse EAE, a role for microglia.
Authors Ilia Vainchtein, Martine Stevelink, Erik Boddeke, Bart Eggen
Affiliation Department of Neuroscience, section Medical Physiology, University Medical
Center Groningen, Groningen, The Netherlands
Abstract
BACKGROUND+OBJECTIVE: Multiple Sclerosis is a chronic, neurodegenerative inflammatory disorder where lesions are often associated with the presence of inflammatory immune cells. Using experimental autoimmune encephalomyelitis (EAE), an animal model
for MS, infiltrated macrophages have been identified as the main driving force behind the
progression of EAE. However, the role of microglia and other components of the infiltrating myeloid immune compartment remain under examined. Here, we studied microglia
and infiltrating myeloid immune cells in more detail, in particular at the less well defined,
later stages of EAE.
MATERIALS+METHODS: EAE was induced in C57BL/6 mice using MOG35-55/CFA and
pertussis toxin. Mice were terminated when their hind legs were paralyzed (acute phase)
or 4-5 days after this time point when their EAE symptoms started to decline (slight remission). Subsequently, spinal cords were fixed and processed for immunohistochemistry
or mechanically dissociated for cell isolation and subsequent FACS experiments. Using
antibodies against CD11b, CD45, Ly-6C, Ly-6G, CD11c, and MHCII we have sorted pure
microglia (CD11b+, CD45+ Ly-6C-) and various myeloid immune cell populations and
analyzed their RNA expression profiles with quantitative RT-PCR.
RESULTS: Immunohistochemistry results showed that Iba1-positive cells are always Ly6C negative, indicating that Iba1 positive cells are microglia. During EAE dense Ly-6C
positive clusters appeared, which represent infiltrated myeloid cells. Microglia numbers
extensively increased during EAE and displayed an activated morphology, not only around
dense Ly-6C positive clusters, but throughout the spinal cord. Interestingly, at the slight
remission stage, the Ly-6C positive clusters were no longer present. Instead very dense
Iba1 positive microglia nodules were observed. Flow cytometry indicated that microglia
upregulated their expression of MHCII during EAE, while the highest MHCII expression
was detected in CD11c+ dendritic cells at the acute phase. Apart from these dendritic
cells we have sorted macrophages and granulocytes. Macrophages and dendritic cells
upregulated antigen presentation and myelin uptake related gene expression, whereas
specifically the granulocytes have very high RNA expression of IL-1β and IL-10, indicating that these cells are actively involved EAE-related inflammation.
CONCLUSIONS: During EAE, various peripheral immune cells infiltrate and although
macrophages and dendritic cells have shown to be involved in EAE, granulocytes also
21
seem to play a major role. Microglia upregulate MHCII and cluster together at the later
stages of EAE when the infiltrates have disappeared. This suggests an unidentified role for
microglia during later stages of EAE, when mice display slight improvement in EAE score.
Jordon Dunham
Dichotomous outcome of IL-7 receptor (CD127) blockade in non-human primate experimental
autoimmune encephalomyelitis.
Authors Jordon Dunham1,2,3,5, Li-Fen Lee4, Nikki van Driel1, Jon D. Laman5, John C.
Lin4, Jan Bauer6, Bert A. ‘t Hart1,2,3,5, and Yolanda S. Kap1
Affiliation 1Department of Immunobiology, Biomedical Primate Research Centre,
Rijswijk, The Netherlands;
2
MS Centre Erasmus, Rotterdam, The Netherlands;
3
Department of Immunology, Erasmus MC, University Medical Center,
Rotterdam, The Netherlands;
4
Rinat, Pfizer Inc, South San Francisco, CA;
5
University Groningen, University Medical Center, Department of
Neuroscience, Groningen, The Netherlands;
6
Medical University of Vienna, Center for Brain Research, Vienna, Austria
Abstract
Background & Objective: Interleukin-7 (IL-7) has complex biology with numerous
functions, including T cell survival and proliferation, growth promotion of B cell progenitors, and enhancement of macrophage migration. Antibody blockade or deletion of the
IL-7 receptor a (CD127) in mouse models of experimental autoimmune encephalomyelitis (EAE) ameliorates disease, demonstrating an important pathogenic function of IL-7.
Evidence also suggests the IL-7/CD127 pathway may play an important role in multiple
sclerosis (MS). Enhanced expression of both IL-7 protein and IL-7 mRNA is found in
the cerebrospinal fluid of MS patients, with T cells isolated from the periphery and CNS
exhibiting increased IL-7R expression. Here, we investigated whether CD127 blockade
modulates EAE in a non-human primate model.
Methods: EAE was induced in seven female marmoset twins by immunization with a
23-mer peptide from recombinant human myelin oligodendrocyte glycoprotein (MOG3456) emulsified in incomplete Freund’s adjuvant. Treatment with the anti-CD127 mAb or
PBS as control was started 21 days after immunization followed by weekly intravenous
administration.
Results: The anti-CD127 mAb caused functional blockade as shown by reduced phosphorylation of STAT5 upon stimulation with IL-7. Despite functional blockade of CD127,
we report that contrary to a profound clinical effect on EAE of CD127 blocking described
22
in mice, blockade of CD127 in the outbred marmoset could not entirely replicate effects
on the clinical course of EAE. Treatment was associated with reductions of B cells
(CD20+CD40+) and rescuing of CD27 expression on T cells. No treatment-associated
changes were observed in MOG peptide-specific proliferation or IL-17A production by
mononuclear cells. Although we observed no general effect in survival, treatment delayed
disease onset in three fast EAE progressor twins. In this subgroup of marmosets that responded to treatment, a reduction of the percentages of B cells (CD3-CD20+CD40+) and
programmed death receptor 1 (PD1)+ T cells were noted.
Conclusions: The aforementioned heterogeneous responses highlight the complex
nature of IL-7 biology and difficulties translating results obtained in genetically inbred
models to genetically outbred populations.
23
Session 3
Microglia: how the brain talks to the immune system
Chair: dr. Jeffrey Bajramovic
Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
Abstract
For years microglia have been regarded as the macrophages of the brain. It was appreciated that microglia differ from other macrophages in some important aspects as reflected by
the fact microglia were often referred to as ‘immature’ or ‘suppressed’ macrophages.
However, we have learned recently that microglia derive from a different progenitor than
macrophages do and we are learning rapidly about the characteristics of this fascinating
cell type. This session will focus on what distinguishes microglia from other macrophages, both in terms of expressed proteins as in terms of functionality. In addition, we will
discuss the necessity and the possibilities to study microglia biology for the pathogenesis
of multiple sclerosis.
-G
inhoux F, Greter M, Leboeuf M, Nandi S, See P, Gokhan S, Mehler MF, Conway SJ, Ng
LG, Stanley ER, Samokhvalov IM, Merad M. Science. 2010. 330(6005):841-5.
- Butovsky O, Jedrychowski MP, Moore CS, Cialic R, Lanser AJ, Gabriely G, Koeglsperger
T, Dake B, Wu PM, Doykan CE, Fanek Z, Liu L, Chen Z, Rothstein JD, Ransohoff RM,
Gygi SP, Antel JP, Weiner HL. Nat Neurosci. 2014. (1):131-43.
- Gosselin D, Link VM, Romanoski CE, Fonseca GJ, Eichenfield DZ, Spann NJ, Stender
JD, Chun HB, Garner H, Geissmann F, Glass CK. Cell. 2014.159(6):1327-40.
- Holtman IR, Noback M, Bijlsma M, Duong KN, van der Geest MA, Ketelaars PT, Brouwer
N, Vainchtein ID, Eggen BJ, Boddeke HW. Glia. 2015 Mar 25.
- Szulzewsky F, Pelz A, Feng X, Synowitz M, Markovic D, Langmann T, Holtman IR, Wang
X, Eggen BJ, Boddeke HW, Hambardzumyan D, Wolf SA, Kettenmann H. PLoS One.
2015. 10(2)
- Burm SM, Zuiderwijk-Sick EA, ‘t Jong AE, van der Putten C, Veth J, Kondova I, Bajramovic JJ. J Neurosci. 2015. 35(2):678-87.
- Peferoen LA, Vogel DY, Ummenthum K, Breur M, Heijnen PD, Gerritsen WH, Peferoen-Baert RM, van der Valk P, Dijkstra CD, Amor S. J Neuropathol Exp Neurol. 2015.
74(1):48-63.
24
Inge Holtman
Genome-wide approaches to study (micro) glia in health and disease: 1) Glia Open Access
Database (GOAD; www.goad.education) and 2) a co-expression meta-analysis of primed
microglia
Authors I.R. Holtman1, H.W.G.M. Boddeke1*, B.J.L. Eggen1*
Affiliation 1Medical Physiology, University of Groningen, University Medical Center
Groningen, Groningen, The Netherlands
Abstract
Recently a remarkable number of genome-wide transcriptome profiles from pure populations of glia cells has come available. This results in an unprecedented amount of data
that can be used to study glia cells in health and disease. We recently developed the
Glia Open Access Database (GOAD), to make this data easily available (url: www.goad.
education). Moreover, we have done an extensive co-expression meta-analysis of microglia
from different mouse models such as aging, Alzheimer’s Disease and Amyotrophic Lateral
Sclerosis. A highly consistent consensus transcriptional profile of up-regulated genes
was identified in all models of primed microglia, which prominently differed from the
acute inflammatory gene network induced by lipopolysaccharide (LPS). Where the acute
inflammatory network was significantly enriched for NF-kB signaling, the primed microglia
profile contained key features related to phagosome, lysosome, antigen presentation, and
AD signaling. To summarize, genome-wide approaches offer new data-driven opportunities
to study (micro) glia in health and disease.
Saskia Burm
Innate immune activation in macrophages and microglia
Authors Saskia Burm*, Ella Zuiderwijk-Sick*, Anke ‘t Jong*, Laura Peferoen#, Jan
Bauer§, Celine van der Putten*, Jennifer Veth*, Ivanela Kondova‡, Sandra
Amor#, Jeffrey Bajramovic*
Affiliation *Alternatives Unit, Biomedical Primate Research Centre, Rijswijk, The Netherlands
#
Department of Pathology, VU Medical Centre, Amsterdam, The Netherlands
§
Department of Neuroimmunology, Medical University of Vienna, Vienna, Austria
‡
Animal Science Department, Biomedical Primate Research Centre, Rijswijk,
The Netherlands
Abstract
BACKGROUND+OBJECTIVE: Activated innate immune cells are a prominent hallmark
in multiple sclerosis (MS) lesions and include tissue-resident microglia and infiltrating
macrophages. These cells can be activated via innate immune receptors by pathogens
or by more general cellular stress, for example caused by neuronal degeneration. Recent
studies have implicated NOD-like receptor (NLR)-mediated activation of microglia in
25
several neurodegenerative and infectious brain diseases. Upon activation, NLR can form
multiprotein complexes with inflammatory caspases, called inflammasomes. Inflammasomes link pathogen recognition and cellular stress to the processing of the pro-inflammatory cytokine interleukin (IL)-1β. Whereas inflammasome-mediated activation is heavily
studied in hematopoietic macrophages, much less is known about microglia. Although
microglia resemble hematopoietic macrophages in phenotype and function, they originate
from a distinct progenitor. The objectives of this study were to characterize involvement
of the inflammasome in MS lesion development and to compare inflammasome-mediated
activation in microglia and hematopoietic macrophages.
METHODS: We studied IL-1β expression in well-characterized MS lesions, including
preactive and (chronic) active lesions. To directly compare inflammasome-mediated
activation in different types of macrophages, we isolated primary microglia and hematopoietic macrophages from adult, healthy rhesus macaques. We analyzed the expression
profile of NLR and inflammatory caspases and characterized inflammasome activation and
regulation in detail.
RESULTS: We here demonstrate that IL-1β expression is only observed in microglial cells
in pre-active MS lesions. In contrast, other MS lesion types, that also include infiltrating
macrophages, are devoid of IL-1β expression. Furthermore, we demonstrate that in vitro
primary microglia respond to the same innate stimuli as hematopoietic macrophages.
However, microglial responses are more persistent due to lack of negative regulation on
pro-IL-1β expression. In addition, we show that while caspase 1, 4 and 5 activation is pivotal for inflammasome-induced IL-1β secretion by hematopoietic macrophages, microglial
secretion of IL-1β is only partially dependent on these inflammatory caspases.
CONCLUSIONS: These results indicate involvement of the inflammasome in early MS
lesions. Furthermore, we identify key cell type-specific differences between microglia
and hematopoietic macrophages that may aid the development of strategies to modulate
innate immune responses in the brain.
Laura Peferoen
Microglia show an intermediate activation status in early lesion formationin multiple sclerosis
Authors Laura A.N. Peferoen1*, Daphne Y.S. Vogel1,2*, Kimberley Ummenthum1,
Marjolein Breur2, Wouter Gerritsen1, Christien D Dijkstra2, Sandra Amor1,3
Affiliation 1Department of Pathology, VU University Medical Center, the Netherlands
2
Department of Molecular Cell Biology and Immunology, VU University
Medical Center, the Netherlands
3
Department of Neuroimmunology Unit, Blizard Institute, Queen Mary
University of London, UK
26
Abstract
BACKGROUND+OBJECTIVE: Microglia play an important role during lesion formation in
multiple sclerosis (MS). Well before the peripheral immune systems is involved and any
sign of myelin damage is noticeable, foci of activated microglia appear in the normal
appearing white matter (NAWM). Many of these so called preactive lesions are suggested
to spontaneously resolve rather than developing into destructive lesions. This suggest that
intrinsic regulation exists, which can stop lesion progression at an early stage.
Activated microglia fulfil a broad range of functions both beneficial and harmful to the
environment. Environmental signals are widely considered to contribute to the ‘switch’
between an immunoregulatory (M2) and a pro-inflammatory (M1) phentotype, in preactive
lesions such signal might be the key to the developemt of active MS lesions.
METHODS: Immunohistochemistry was used to determine the activation status of microglia in preactive lesions. First we screened primary human microglia polarized in a M1 or
M2 phenotype for distinctive markers in vitro. To investigate whether a polarized phenotype is susceptible to changes in the microenvironment and thus switch between M1 and
M2, polarized microglia were stimulated with the opposing treatment and qPCR for the
most distinctive markers was performed.
RESULTS: Our data showed that CD40, CD80 and CD74 were the most distinctive markers for M1, and mannose receptor (MR) for M2. Additionally, M1 microglia produce higher
levels of pro-inflammatory chemokines CXCL10 and CCL2, whereas M2 phenotypes also
produce CCL22. Using immunocytochemitry with antibodies directed to these markers
revealed that all preactive lesions express an intermediate expression pattern; no preactive lesions were comprised specifically of M1 or M2 microglia. All activated microglia
abundantly express M1 markers CD40, CD86, CD74 and the M2 cytokine CCL22. This
indicates an intermediate activation status of microglia in preactive lesions. Furthermore,
we showed that polarization of human microglia, in vitro, is not static, but a dynamic
process in which microglia can switch from a M1 to a M2 phenotype and vice versa.
CONCLUSIONS: Taken together, our data delineate the versatility of microglia, both in
vitro and in vivo, in response to inflammatory signals from the CNS, already in early MS
lesion formation.
27
Session 4
Inflammation at the barriers of the central nervous system
in MS
Chair: prof.dr. Elga de Vries
Department of Molecular Cell Biology and Immunology, Neuroscience Campus
Amsterdam, VU University Medical Center, MS Center Amsterdam, The Netherlands
Abstract
Leukocyte migration into the central nervous system (CNS) is a key stage in the development of multiple sclerosis (MS). In this process, inflammation and impaired function
of the barriers of the CNS play a prominent role. Active participation of cells composing
the blood-brain barrier (endothelial cells forming the BBB)) and the blood-cerebrospinal
fluid barrier (epithelial cells of the choroid plexus forming the BCSFB) is critical to allow
immune cells to pass these barriers of the CNS and induce severe and irreversible tissue
damage. To fully grasp this process, the understanding of the key regulators of the brain
endothelial and choroid plexus epithelial cell dynamics is essential.
Within the current session, the altered cellular dynamics and interactions of the brain
endothelial cells that form the BBB and the epithelial cells of the BCSFB that permit leukocyte migration into the CNS will be addressed. A better understanding of CNS barrier
alterations in neuroinflammation might lead to new ways to promote their function in MS.
Gijs Kooij
The role of the choroid plexus in MS
Authors G. Kooij, S.M.A. van der Pol, W.W. Kamphuis, C.D. Dijkstra, H.E. de Vries
Affiliation Department of Molecular Cell Biology and Immunology, Neuroscience Campus
Amsterdam, VU University Medical Center, MS Center Amsterdam, The
Netherlands
Abstract
Background and objectives: Multiple sclerosis (MS) is a chronic neuro-inflammatory disorder, which is marked by the invasion of the central nervous system by monocyte-derived macrophages and auto-reactive T cells across the brain vasculature. Data
from experimental animal models recently implied that the passage of leukocytes across
the brain vasculature is preceded by their traversal across the blood-cerebrospinal fluid
barrier (BCSFB) of the choroid plexus. The correlation between the presence of leukocytes in the CSF of patients suffering from MS and the number of inflammatory lesions as
detected by magnetic resonance imaging suggests that inflammation at the choroid plexus
contributes to the disease, although in a yet unknown fashion.
Methods: Immunohistochemistry on human post-mortem choroid plexus brain tissues,
real-time PCR, Western Blotting, deep sequencing and experimental autoimmune encephalomyelitis (EAE) using cldn3-/- mice.
28
Results: We here provide first insights into the involvement of the choroid plexus in the
onset and severity of the disease and in particular address the role of the tight junction
protein claudin-3 (CLDN3) in this process. Detailed analysis of human post-mortem brain
tissue revealed a selective loss of CLDN3 at the choroid plexus in MS patients compared
to control tissues. Importantly, mice that lack CLDN3 have an impaired BCSFB and experience a more rapid onset and exacerbated clinical signs of EAE, which coincides with
enhanced levels of infiltrated leukocytes in their CSF. To provide a comprehensive view
on CP alterations in MS, we used a deep sequencing approach (7 secondary progressive
(SP-) MS patients and age/sex-matched controls), which revealed a large amount of differentially expressed genes.
Conclusions: Together, this study highlights a profound role for the choroid plexus in
the pathogenesis of multiple sclerosis, and implies that CLDN3 may be regarded as a
crucial and novel determinant of BCSFB integrity.
Jasmine Vanmol
Relation between LXR activation and blood-brain barrier function
during neuroinflammation in multiple sclerosis
Authors J. Vanmol1, T. Vanmierlo1, J.F.J. Bogie1, S.M.A. van der Pol2, M.Mizee2,
P. Stinissen1, N. Hellings1, H.E. de Vries2, J.J.A. Hendriks1
1
Affiliation Hasselt University, Biomedical Research Institute, School of Life Sciences,
Diepenbeek, Belgium
2
Department of Molecular Cell Biology and Immunology, Neuroscience
Campus Amsterdam, VU University Medical Center, Amsterdam, the
Netherlands
Abstract
Background and objective: Multiple sclerosis (MS) is a demyelinating disease
of the central nervous system (CNS), featured by an early disruption of the blood-brain
barrier (BBB). Brain endothelial cells (BECs) tightly regulate BBB function and are
regarded as the gatekeepers of the CNS. Changes in BBB properties comprise alterations
in the tight and adherent junctions, differences in BEC adhesion molecule expression,
and modulated chemoattraction of leukocytes. At the crossroads of linking metabolic and
inflammatory responses are the liver X receptors (LXRs). In this study, the effect of LXR
activation on BEC function was determined.
Methods: The effect of inflammatory stimuli (interferon (IFN) gamma and tumor necrosis factor (TNF) alpha in combination with the LXR agonist GW3965 was studied in vitro
in the human brain endothelial cell line hCMEC/D3 and ex vivo in primary CECs isolated
from wild type and LXRalpha or LXRbeta isoform knockout mice using dextran gradient
29
centrifugation. Modulation of BBB properties and pro-inflammatory chemoattractants
were quantified by qPCR.
Results: In vitro, LXR activation in hCMEC/D3 suppressed the cell surface expression of
the adhesion molecules ICAM-1 and VCAM-1 in a dose-dependent manner. Furthermore,
the expression of CXC chemokines was reduced in hCMEC/D3 following LXR activation.
Ex vivo, LXR response genes (ABCA1 and ABCG1) showed less upregulation after LXR
activation in BECs isolated from LXRbeta isoform knockout mice compared to LXRalpha
isoform knockout and wild type mice.
Conclusions: Under inflammatory conditions, BBB properties are positively affected
by the activation of LXRs in BECs. The suppression of adhesion molecule expression and
chemoattraction by an LXR agonist provides an anti-inflammatory environment and may
lead to reduced leukocyte extravasation into the CNS. LXRbeta appears the main LXR isoform in brain endothelial cells of the BBB confirming the importance of LXR subtype-specific research.
Claudio Derada Troletti
Molecular regulation of the blood-brain barrier phenotype
Authors C. Derada Troletti1, W.W Kamphuis1, A. Reijerkerk2, B. Van Het Hof AJ1,
I.A. Romero3 and H.E de Vries1
1
Affiliation Blood-brain barrier research group, Department of Molecular Cell Biology and
Immunology, Neuroscience Campus Amsterdam, VU Medical Centre, P.O. Box
7057, 1007 MB Amsterdam, The Netherlands
2
Pluriomics therapeutics, Galileiweg 8, 2333 BD Leiden, The Netherlands
3
Biomedical Research Network, The Open University, Walton Hall, Milton
Keynes MK7 6AA, UK
Abstract
Background + objective: An early event in MS is the impairment function of the
blood-brain barrier (BBB) which consists of specialized brain endothelial cells (BECs)
supported by surrounding glial cells. Both inflammation and BBB dysfunction are pathological hallmarks of MS and affect brain homeostasis.
Endothelial to mesenchymal transition (EndoMT) is a dynamic process that has been
linked to pathological setting like cancer and fibrosis. During EndoMT, endothelial cells
dedifferentiate into mesenchymal cells and as a result loose their tight and adherent
junction, which are essential for the BBB function. The EndoMT process is known to be
induced by transforming growth factor (TGF)-β which activates two important transcription factors: Snail1 and Snail2. Furthermore, recent discoveries unravelled a critical role
for microRNAs (miRNA) in controlling the barrier properties of the endothelium in the
30
brain. Interestingly, both Snail1 and Snail2 are both predicted targets of miRNA-30c, of
which we have previously shown that this miRNA is significantly downregulated both in
MS patients post-mortem material as well as in inflamed human brain endothelial cells
(hCMEC/D3). We believe that TGF-β can induced EndoMT in BECs and this event can
play an important role in the alteration of the BBB phenotype. Moreover, we think that a
miRNA based approach could restore the normal BBB phenotype by inhibiting the dedifferentiation of the BECs via targeting Snail1 and Snail2.
Methods: To investigate the EndoMT process, hCMEC/D3 were stimulated for 48 hours
with 10ng/ml of TGF-β and interleukin (IL)-1β. qPCR and western blot were used to analyze gene and protein expression.
Results: Our preliminary data show that TGF-β and IL-1β can induce EndoMT in
hCMEC/D3 which can be demonstrated by the loss of expression of brain endothelial
markers and a gain in expression of mesenchymal markers. Moreover, Snail1 and Snail2
were upregulated in treated hCMEC/D3.
Conclusions: Our findings suggest that EndoMT can be involved in the BBB breakdown and participate in the pathogenesis of MS. Moreover, repair of a disturbed BBB
through a specific miRNA approach may represent a novel avenue for effective treatment
of MS.
31
Session 5
Progressive MS Alliance
Chair: Ceri Angood Napier
Director of Programmes, Multiple Sclerosis International Federation
Sandra Amor
Immune-primed microglia: a factor underlying progressive multiple sclerosis
Authors Sandra Amor
Affiliation Department of Pathology, VU University Medical Center, 1007MB,
Amsterdam, The Netherlands.
Abstract
This team aims to investigate the specific role of brain cells called “microglia” on MS progression. Both primary and secondary progressive MS start around 35 years, irrespective
of relapses, suggesting that age may be a factor. Microglia help to activate the immune
system (which attacks the brain and spinal cord in MS), but also dampen inflammation,
producing substances that promote repair. A subtle balance exists between these two
opposing functions. With increasing age, this balance shifts, and microglia become less
effective in their protective functions, and more active stimulating damage, possibly
explaining why progression increases with age. This team proposes to examine microglia
from people with different types of MS, and people without neurological disease, taking
into account their ages. This may reveal differences between “young” and “old” microglia, and differences between people with and without MS. They are extending these
experiments in mice with relapsing-remitting MS-like disease that later becomes progressive.
32
Philip Nijland
Inflammation drives mitochondrial dysfunction and associated neurodegeneration in multiple
sclerosis
Authors Philip G. Nijland1, Andreia Carvalho1, Maarten E. Witte2, Tim Muntslag1,
Susanne MA van der Pol1, Helga E. de Vries1, Richard Reynolds3 and Jack van
Horssen1
Affiliation 1Department of Molecular Cell Biology and Immunology, VU University
Medical Center, 1007MB, Amsterdam, The Netherlands.
2
Institute of Clinical Neuroimmunology, Ludwig-Maximilians University
Munich, Munich, Germany
3
Division of Brain Sciences, Faculty of Medicine, Imperial College London,
Hammersmith Hospital, London, UK.
Abstract
In progressive MS patients, the steady rise in clinical disability is the direct result of
neuronal tissue loss. However, remarkably little is known about the pathological processes
leading to neurodegeneration. A better understanding of the mechanisms that drive neuronal injury and loss in progressive MS patients is required for the development of novel
therapeutic treatment strategies aimed at limiting neurodegeneration. In the last decade,
we and others have shown that neuronal mitochondrial dysfunction is closely associated
with neuronal damage and loss in progressive MS patients. Our recent data using brain
tissue samples from progressive MS patients and a novel animal model of MS suggest
that inflammatory processes in the meninges and cortex of MS patients contribute to
neuronal mitochondrial alterations. Moreover, we show that key inflammatory mediators
produced by activated cortical microglia and meningeal infiltrates induce mitochondrial
defects. Our preliminary studies will provide important new insights in the pathogenic
mechanisms that drive progressive MS and might ultimately lead to the identification of
putative therapeutic targets.
Charlotte Teunissen
Discovery of biomarkers reflecting progression pathophysiology for primary progressive MS
subtype by applying next generation sequencing and novel multiplex aptamer approach.
Authors A. Malekzadeh, J. Kuhle, C. Leurs, C. Oudejans, J. Killestein, CE Teunissen
Affiliation VU University Medical Center Amsterdam
Abstract
Background: The heterogeneity in MS disease mechanisms is observed at both the
patho-histological level and clinical disease course. The need for plasma based biomarkers for MS is required due to relative ease of access to blood. To attain new leads
to unravel the mechanisms and predict MS progression, we previously selected plasma
33
samples of PPMS (n=10) patients, relapse-onset rapid progressors (RO-rapid, n=10) and
relapse-onset slow progressors (RO-slow n=10) based on their disease course during ~4
years of follow-up and performed novel multiplex aptamer proteomics (SomaScan).
Aim: The aim of the current proposal was to validate these proteomics results in plasma samples of MS patients with relapse-onset (RO) slow, RO-rapid disease course and
primary progressive (PP), by aptamer proteomics. Two independent cohorts (Basel and
Amsterdam) were selected, based on similar clinical characteristics as the previous study.
In parallel, we used the same plasma samples for next generation sequencing, this to gain
insight into to the epigenetic and transcriptomic pathways associated with these progression mechanisms.
Results: Group comparisons between RO-slow and RO-rapid showed interesting markers
that are associated with neuroprotection and inflammation. Group comparisons between
RO-all and PP yielded several interesting markers associated with inflammatory pathways,
cell motility, cytoskeleton and cell cycle related pathways.
Lastly, similar pathways were observed by next generation seqeuncing on plasma for
comparisons between RO-slow to RO-rapid and RO-all compared to PP. We also observed
several regulatory non-coding RNAs and transcription factors differentiating the groups.
The significant markers derived from sequencing are currently analyzed in an independent
cohort by RT-PCR
Conclusion: This innovative approach will lead to the discovery of marker(s) that potentially reflect PP and RO MS disease progression and aid in subtype diagnostics. Moreover, we will gain insight into pathophysiological mechanisms by means of proteomics,
transcriptomics and epigenetic mechanisms that are involved in PP and RO progression.
Peter Feys
Towards a shared data repository to enhance the standards of rehabilitation in MS: feasibility,
capacity building and proof-of-concept on exercise therapy & mobility measures.
Authors Feys P1, Held Bradford E2, Baert I1, Wagner J2
Affiliation 1Hasselt University, REVAL rehabilitation Research Center, BIOMED, Diepenbeek, Belgium
2
Saint Louis University, Doisy College of Health Sciences, St Louis, United
States
Abstract
Persons with progressive MS show overall more disability than those with the relapsing
remitting type. Exercise therapy is a potentially effective treatment modality. However,
despite an explosion of research on physical rehabilitation and exercise, it is not yet clear
34
whether beneficial effects are equally present in progressive compared to relapsing-remitting type of MS, and to what degree effects are dependent on severity level and the
intervention (modality, duration and intensity). Also, it is not well-known which outcome
measures are the best to measure changes in mobility that are meaningful to the person
with MS.
The development of this knowledge, specifically on exercise but also generally on rehabilitation, has been delayed in part by four issues: 1) small sample sizes that do not
allow distinction of effects according to MS type or disability level, 2) limited systematic
description of the intervention content (so-called ‘black box’ of rehabilitation), 3)inconsistent inclusion of multi-dimensional outcome measures with insufficient knowledge on
their accuracy and values of meaningful change and 4) limited efforts to determine the
dosage-response of different rehabilitation strategies.
The long-term goal is to provide answers to research questions on the multi-dimensional
effects of rehabilitation according to type of MS or disability level. This project concerns
preparing the construction of a large shared data repository that will be established by 1)
retrospective data retrieval of individual patient data of published studies and 2) prospective data entry by clinical and research centers. This will allow researchers to investigate
questions on the (comparative) effects of specific interventions and settings, or on the
appropriateness of different outcome measures. Ultimately, this will lead to improved
standards in MS rehabilitation practice.
This study will allow us to investigate 1) the legal regulation of repositories in Europe and
the United States, 2) knowledge transfer of existing registries, 3) researcher’s perceived
barriers and facilitators to data sharing, 4) clinician’s willingness and ability to provide
data in a registry, 5) engagement of experts to collaborate in workgroups to define the
outcome measures for the registry, and opinion on classification systems for treatment.
Proof-of-concept studies will be performed in the domain of exercise therapy and mobility
outcome measures. A platform will be established for information and communication.
35
Session 6
Remyelination in MS: from basic science to therapy?
Chair: dr. Wia Baron
Department of Cell Biology, University Medical Center Groningen, University of Groningen,
Antonius Deusinglaan 1, 9713 AV Groningen, the Netherlands
Abstract
Multiple sclerosis (MS) is a chronic demyelinating disease of unknown etiology affecting
the central nervous system. Clinical symptoms are manifested in a relapsing-remitting
or progressive course, leading to an ultimate decline in neurological activity. Current approved MS therapies are primarily directed against the immune system, which is effective
in relapsing-remitting MS but not in the progressive stages. A major challenge in the field
is to address the progressive types of MS with regenerative and neuroprotective strategies.
Indeed, remyelination following demyelination is essential for axonal survival and restoration of saltatory conduction, and its failure is a major cause of the neurological deficits
in MS. Therefore, restoring remyelination should provide an effective treatment in halting
disease progression and reversing disability. For the development of such a therapy, an
understanding of molecular and cellular mechanisms that contribute to failure or restoration of remyelination is imperative.
Remyelination of denuded axons requires the generation of new oligodendrocytes from
oligodendrocyte progenitor cells (OPCs). The decline of remyelination in progressive MS
is in part attributed to inadequate OPC migration towards the lesion and/or decreased
OPC survival or in most cases to failure of OPC differentiation within the demyelinated
areas. In this session, Jamie Lim (VUmc) will show evidence that Nrf2 activators protect
oligodendrocyte from oxidative damage, and promote OPC differentiation. Inge Werkman
(UMCG) will focus on the role of micro-environmental signals and present data on the
distinct modulation of (re)myelination efficiency by cortical and non-cortical astrocytes,
Finally, Arun Thiruvalluvan (UMCG) will speak on the remyelination potential of human
iPSC-derived OPCs. All speakers will highlight how their findings on basic science (cel)
biology will provide possibilities for improved and targeted remyelination in MS.
Jamie Lim
Nrf2 activators: a novel strategy to promote oligodendrocyte survival in multiple sclerosis?
Authors Jamie Lim, Susanne van der Pol, Joost Drexhage, Elga de Vries, Jack van
Horssen
Affiliation Department of Molecular Cell Biology and Immunology, VU University Medical
Center Amsterdam, the Netherlands
Abstract
BACKGROUND: Oligodendrocyte damage and loss are key features of multiple sclerosis
(MS) pathology and oligodendrocytes appear to be particularly vulnerable to reactive
36
oxygen species (ROS). In vitro studies showed that ROS induce cell death and prevent
the differentiation of oligodendrocyte precursor cells (OPCs) into mature myelin-producing oligodendrocytes. Hence, a potential therapeutic strategy to protect these cells from
ROS-mediated damage is urgently needed. Here we investigated the efficacy of several
compounds that are able to boost antioxidant enzyme production, including monomethyl
fumarate (MMF), sulforaphane (SFN) and Protandim. These compounds are thought to
exert their protective function via activation of the nuclear-factor-E2-related factor-2
(Nrf2) transcriptional pathway, which is involved in the production of antioxidant enzymes
necessary for oxidative stress defense.
OBJECTIVE: To investigate the potential of different Nrf2 activators to boost antioxidant
enzyme expression in oligodendrocytes, protect them from ROS-mediated cell death and
promote the differentiation of OPCs under inflammatory and oxidative conditions.
METHODS: Primary rat oligodendrocytes were treated with different concentrations of
MMF, SFN and Protandim. Expression of antioxidant enzymes was analyzed by PCR
and Western blot analyses. To study the beneficial effects of the different Nrf2 activators, oligodendrocytes were incubated with Nrf2 activators and subsequently exposed to
various concentrations of hydrogen peroxide. Oligodendrocyte cell survival was measured
by live/death viability assay. Moreover, to investigate whether Protandim can promote the
differentiation of OPCs under inflammatory or oxidative conditions, OPCs were treated
with Protandim or vehicle control prior to exposing them to sub-lethal concentrations of
tumor necrosis factor or hydrogen peroxide for 5 days. OPC differentiation was determined
by comparing the ratio of MBP-positive to MBP-negative oligodendrocytes.
RESULTS: SFN, MMF and Protandim are well-tolerated and induce Nrf2-driven antioxidant enzyme production in oligodendrocytes. Protandim was the most potent compound
with regard to antioxidant enzyme induction and protected oligodendrocytes against
ROS-induced cytotoxicity. Moreover, Protandim reduced the inhibitory effects of tumor
necrosis factor and hydrogen peroxide on OPC differentiation.
CONCLUSIONS: Nrf2 activators, particularly Protandim, are able to induce antioxidant
enzyme production and protect oligodendrocytes against inflammatory and oxidative
insults making them interesting therapeutic compounds.
37
Inge Werkman
Distinct modulation of myelination efficiency by cortical and non-cortical astrocytes
Authors Inge Werkman, Dick Hoekstra, Wia Baron
Affiliation Department of Cell Biology, University Medical Center Groningen, University of
Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, the Netherlands
Abstract
BACKGROUND+OBJECTIVE: Multiple sclerosis (MS) is an inflammation-mediated demyelinating disease of the central nervous system, which eventually results in axonal degeneration due to failure of remyelination. Functional remyelination depends, among others,
on carefully regulated signalling events, and requires sequential activation, recruitment
and maturation of oligodendrocyte progenitor cells (OPCs). In addition to demyelination
in the non-cortical areas of the brain, also cortical demyelination has been recognized
as a feature of MS pathology. Intriguingly, remyelination is more efficient in cortical MS
lesions. Underlying mechanisms of this remarkable difference in remyelination efficiency
are likely related to cellular and environmental differences of cortical and non-cortical lesions. Here, we investigated how cortical, as opposed to non-cortical astrocytes modulate
myelination efficiency.
METHODS: In vitro myelinating cultures were placed on a feeding layer of either cortical
or non-cortical astrocytes. In addition, the effect of astrocyte-derived secreted factors,
extracellular matrix (ECM) factors or cues that dependent on cell-cell interaction on OPC
behaviour were examined in primary oligodendrocyte monocultures.
RESULTS: Our data reveal that in vitro myelination is more pronounced on a feeding layer
of adult cortical than on non-cortical astrocytes. Secreted factors from cortical astrocytes
slightly increased myelin-like membrane formation as compared to secreted factors from
non-cortical astrocytes, while no effect on OPC differentiation was observed. In addition, secreted factors from cortical astrocytes promoted the viability of oligodendrocytes.
However, OPC viability was significantly increased in the presence of conditioned-medium
obtained from either astrocyte as compared to normal medium. No significant differences
in OPC maturation were observed, as induced by cell-cell contact and astrocyte deposited
ECM-mediated signals, derived from either cortical or non-cortical astrocytes.
CONCLUSIONS: These findings thus further highlight that cortical astrocytes are more
supportive to (re)myelination than non-cortical astrocytes, however, via which means
remains to be established. Astrocyte derived conditioned media, ECM and direct cellcell contact had minimal effects on OPC behaviour. Therefore, it seems likely that the
enhanced myelination efficiency by cortical astrocytes is caused by an indirect effect on
myelination, presumably via neurons.
38
Arun Thiruvalluvan
Functionality of human induced pluripotent stem cell-derived oligodendrocytes in an MS
primate model
Authors Arun Thiruvalluvan, Marcin Czepiel, Yolanda Kap, Ilia Vainchtein, Jeroen
Kuipers, Marjolein Bijlard, Wia Baron, Ben Giepmans, Wolfgang Brück,
Bert ’t Hart, Erik Boddeke, Sjef Copray
Affiliation Department of Neurosciences, University Medical Centre Groningen, Groningen, the Netherlands.
Abstract
BACKGROUND+OBJECTIVE: Fast remyelination by endogenous oligodendrocyte precursor
cells (OPCs) is essential to prevent axonal and subsequent retrograde neuronal degeneration in demyelinating lesions in Multiple sclerosis (MS). In chronic lesions, however, the
remyelination capacity of OPCs becomes insufficient. Cell therapy with exogenous remyelinating cells has been forwarded as a potential strategy to replace the failing endogenous OPCs, but the absence of a suitable autologous source for such cells has hampered
such an approach so far. Induced pluripotent stem cells (iPSCs) have provided a unique
autologous source for remyelinating cells. In previous studies in rodents we have demonstrated the efficacy of implanted iPSC-derived OPCs to remyelinate demyelinated axons
and to reduce symptoms in the EAE mouse model for MS. In the present study, we aim to
investigate the functionality of iPSC-derived OPCs in a nonhuman primate model for MS.
METHODS: We have generated human iPSCs by nonvirally reprogramming fibroblasts
isolated from a small skin biopt and developed a protocol to differentiate them into
OPCs. After characterization and validation of their myelin-forming capacity in vitro (DRG
co-culture) as well as in vivo (cuprizone mice), we have implanted the human iPSC-derived OPCs stereotactically in the cortex of a nonhuman primate model for MS: the EAE
marmoset model. This primate model is considered the most adequate animal model for
RR-MS as it accurately mimics the relapsing-remitting disease course and the occurrence of typical demyelinated, inflammation-invested lesions as found in the brain of MS
patients. We have examined the fate and functionality of human iPSC-derived OPCs up to
40 days after implantation in extensive immunohistochemical analyses.
RESULTS:
Our results show that:
- the human iPSC-derived OPCs survive after stereotactic implantation within the marmoset brain
- they selectively migrate to the demyelination lesions in the corpus callosum
- they differentiate and maturate into myelin-forming oligodendrocytes
- they form new myelin around denuded axons in the MS-lesion.
39
CONCLUSIONS: Our findings in the nonhuman primate model for MS are the first ones
indicating that human iPSC-derived OPCs may be novel candidates for a remyelination
therapy for MS patients.
40
Session 7
Imaging
Chair: dr.ir. Hugo Vrenken
Department of Radiology and Nuclear Medicine and Department of Physics and Medical
Technology, Neuroscience Campus Amsterdam, VU University Medical Center, The
Netherlands
Abstract
This session is dedicated to studies of MS through imaging, including but not limited to
magnetic resonance imaging (MRI). MRI has played an important role in MS research already
for a long time. Recent work shows that MRI could improve accuracy of clinical prognosis:
clinical worsening is related to whole-brain MRI outcome measures such as lesion volume
change and whole-brain volume change (Popescu 2013), but also ventricle volume change
(Lukas 2010, Popescu 2013) and upper cervical spinal cord volume loss (Lukas 2015).
MRI has also contributed to understanding disease evolution. Gray matter volume loss,
or atrophy, has become an important outcome measure, and much work has been done
to improve its measurement (e.g. Popescu 2014) and understand its development (e.g.
Steenwijk 2014). The first talk of this session highlights how, by combining different
MRI techniques, we may disentangle different contributions to the GM atrophy patterns
observed in MS.
Beyond MRI, important recent imaging work has focused on optical coherence tomography (OCT) of the retina (e.g., Balk 2014a, Balk 2015), which has been aptly termed “a
window to the brain”. OCT can provide rapid, non-invasive assessment of retinal pathology (review in Balk 2014b). The second talk of this session focuses on retinal pathology in
MS patients assessed through OCT in a longitudinal study.
Imaging also plays an important role in studies of animal models of MS, whether to
improve the understanding of disease processes or in the development of new treatment
agents for MS. Recent work combining different disease models and different imaging
methods studied the relations between (among other) microglial activation and de- and
remyelination (de Paula Faria 2014a,b,c; Olah 2012). The third talk in this session highlights some recent advances in this field, focusing on PET imaging of microglial activation
and of myelin in the cuprizone mouse model of MS.
-B
alk L, Tewarie P, Killestein J, Polman C, Uitdehaag B, Petzold A. Disease course heterogeneity and OCT in multiple sclerosis. Mult Scler. 2014a;20(9):1198-1206.
- Balk LJ, Petzold A. Current and future potential of retinal optical coherence tomography
in multiple sclerosis with and without optic neuritis. Neurodegener Dis Manag. 2014b;
4(2):165-76. Review.
- Balk LJ, Steenwijk MD, Tewarie P, Daams M, Killestein J, Wattjes MP, Vrenken H,
Barkhof F, Polman CH, Uitdehaag BM, Petzold A. Bidirectional trans-synaptic axonal
degeneration in the visual pathway in multiple sclerosis. J Neurol Neurosurg Psychiatry.
2015;86(4):419-24.
41
-d
e Paula Faria D, Vlaming ML, Copray SC, Tielen F, Anthonijsz HJ, Sijbesma JW, Buchpiguel CA, Dierckx RA, van der Hoorn JW, de Vries EF. PET Imaging of Disease Progression and Treatment Effects in the Experimental Autoimmune Encephalomyelitis Rat
Model. J Nucl Med. 2014a;55(8):1330-1335.
- de Paula Faria D, de Vries EF, Sijbesma JW, Buchpiguel CA, Dierckx RA, Copray SC. PET
imaging of glucose metabolism, neuroinflammation and demyelination in the lysolecithin
rat model for multiple sclerosis. Mult Scler. 2014b;20(11):1443-52.
- de Paula Faria D, de Vries EF, Sijbesma JW, Dierckx RA, Buchpiguel CA, Copray S.
PET imaging of demyelination and remyelination in the cuprizone mouse model for
multiple sclerosis: a comparison between [11C]CIC and [11C]MeDAS. Neuroimage.
2014c;87:395-402.
- Lukas C, Minneboo A, de Groot V, Moraal B, Knol DL, Polman CH, Barkhof F, Vrenken H.
Early central atrophy rate predicts 5 year clinical outcome in multiple sclerosis. J Neurol
Neurosurg Psychiatry. 2010;81(12):1351-6.
- Lukas C, Knol DL, Sombekke MH, Bellenberg B, Hahn HK, Popescu V, Weier K, Radue
EW, Gass A, Kappos L, Naegelin Y, Uitdehaag BM, Geurts JJ, Barkhof F, Vrenken H.
Cervical spinal cord volume loss is related to clinical disability progression in multiple
sclerosis. J Neurol Neurosurg Psychiatry. 2015;86(4):410-8.
- Olah M, Amor S, Brouwer N, Vinet J, Eggen B, Biber K, Boddeke HW. Identification of a
microglia phenotype supportive of remyelination. Glia. 2012;60(2):306-21.
- Popescu V, Agosta F, Hulst HE, Sluimer IC, Knol DL, Sormani MP, Enzinger C, Ropele
S, Alonso J, Sastre-Garriga J, Rovira A, Montalban X, Bodini B, Ciccarelli O, Khaleeli Z,
Chard DT, Matthews L, Palace J, Giorgio A, De Stefano N, Eisele P, Gass A, Polman CH,
Uitdehaag BM, Messina MJ, Comi G, Filippi M, Barkhof F, Vrenken H; MAGNIMS Study
Group. Brain atrophy and lesion load predict long term disability in multiple sclerosis. J
Neurol Neurosurg Psychiatry. 2013;84(10):1082-91.
- Popescu V, Ran NC, Barkhof F, Chard DT, Wheeler-Kingshott CA, Vrenken H. Accurate
GM atrophy quantification in MS using lesion-filling with co-registered 2D lesion masks.
Neuroimage Clin. 2014;4:366-73.
- Steenwijk MD, Daams M, Pouwels PJ, Balk LJ, Tewarie PK, Killestein J, Uitdehaag BM,
Geurts JJ, Barkhof F, Vrenken H. What explains gray matter atrophy in long-standing
multiple sclerosis? Radiology. 2014;272(3):832-42.
42
Martijn Steenwijk
Understanding the relation of gray matter atrophy patterns in multiple sclerosis with other MS
pathology
Authors Martijn D. Steenwijk MSc1, Marita Daams MSc1,2, Petra J.W. Pouwels PhD3,
Lisanne Balk MSc4, Prejaas K. Tewarie MD4, Jeroen J. G. Geurts PhD2,
Frederik Barkhof PhD1, Hugo Vrenken PhD1,3
Affiliation Neuroscience Campus Amsterdam, VU University Medical Center,
The Netherlands
1
Department of Radiology and Nuclear Medicine
2
Department of Anatomy and Neurosciences
3
Department of Physics and Medical Technology
4
Department of Neurology
Abstract
Introduction: Gray matter (GM) atrophy is common in multiple sclerosis (MS), but the
relationship with white matter (WM) pathology is largely unknown. Some studies found
a co-occurrence in specific systems, but a regional analysis across the brain in different
clinical phenotypes is necessary to further understand the disease mechanism underlying
GM atrophy in MS. Therefore we investigated the association between regional GM atrophy and pathology in anatomically connected WM tracts.
Methods: Conventional and diffusion tensor imaging was performed at 3T in 208 patients with long-standing MS and 60 healthy controls. Deep and cortical GM regions were
segmented and quantified, and both lesion volumes and normal appearing WM fractional
anisotropy of their associated tracts were derived using an atlas obtained by probabilistic
tractography in the controls. Linear regression was then performed to quantify the amount
of regional GM atrophy that can be explained by WM pathology in the connected tract.
Results: MS patients showed extensive deep and cortical GM atrophy. Cortical atrophy
was particularly present in frontal and temporal regions. Pathology in connected WM
tracts statistically explained both regional deep and cortical GM atrophy in relapsing-remitting (RR) patients, but only deep GM atrophy in secondary-progressive (SP) patients.
Conclusion: In RRMS patients, both deep and cortical GM atrophy were associated
with pathology in connected WM tracts. In SPMS patients, only regional deep GM atrophy
could be explained by pathology in connected WM tracts. This suggests that in SPMS
patients cortical GM atrophy and WM damage are (at least partly) independent disease
processes.
43
Lisanne Balk
Timing of retinal neuronal and axonal loss in MS; a longitudinal OCT study
Authors Lisanne J. Balk, PhD,1 Andres Cruz-Herranz, MD,2 Philipp Albrecht, MD,3 Sam
Arnow, BS,2 Jeffrey M. Gelfand, MD, MAS,2 Prejaas Tewarie, MD, PhD,1 Joep
Killestein, MD, PhD,1 Bernard M.J. Uitdehaag, MD, PhD,1 Axel Petzold, MD,
PhD1 and Ari J. Green, MD2
1
Affiliation Department of Neurology, VU University Medical Center, Amsterdam, the
Netherlands
2
Department of Neurology, University of California San Francisco, San
Francisco, United States
3
Department of Neurology, Heinrich-Heine University, Düsseldorf, Germany
Abstract
Background: The timing of retinal and axonal atrophy in multiple sclerosis remains unknown. It has often been presumed that the pace of central nervous system tissue atrophy
in MS is consistent throughout the course of disease.
Objective: To investigate the timing of central nervous system tissue atrophy in MS by
evaluating longitudinal retinal volume changes in a broadly representative cohort with
disease duration across the entire arc of disease.
Methods: In this longitudinal study, 135 patients with MS and 16 healthy reference
subjects underwent spectral-domain optical coherence tomography (OCT) at baseline
and two years later. Following OCT quality control, automated segmentation of the the
peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell-inner plexiform layer
(mGCIPL) and macular inner nuclear layer (mINL) was performed. Generalized estimation equations were used to analyze longitudinal changes and associations with disease
duration and clinical measures.
Results: Participants had a median disease duration at baseline of 16.4 years (range
0.1-45.4). Nearly half (44%) of the MS patients had previously experienced MS related optic neuritis (MSON) greater than 6 months prior. The MS patients demonstrated a
significant decrease over two years of the pRNFL (-1.1 µm, 95%CI 1.4 to 0.7,p<0.001)
and mGCIPL (-1.1 µm, 95% CI -1.4 to -0.8,p<0.001), however, this thinning was most
pronounced early in the course of disease. These findings were irrespective of previous
episodes of MSON. No consistent pattern of change was observed for the mINL (-0.03
µm, 95%CI -0.2 to 0.2,p=0.795).
Conclusion: This longitudinal study showed that retinal injury in MS occurs most
rapidly during early stages of disease. The attenuation of atrophy with longer disease duration is suggestive of a plateau effect. These findings emphasize the importance of early
intervention to prevent such injury.
44
Ate Boerema
Longitudinal monitoring of microglia activation and CNS myelin with [11C]PK11195 and [11C]
MEDAS PET imaging in the cuprizone mouse model for Multiple Sclerosis.
Authors Boerema AS1, de Paula Faria D1,2,3, Kurtys E1, Verkuijl M4, Broersen LM4,
Doorduin J1, Klein HC1, Eisel ULM5, Dierckx RAJO1, Copray JCVM2, de Vries
EFJ1
Affiliation Departments of 1Nuclear Medicine & Molecular Imaging and 2Neuroscience,
University of Groningen, University Medical Center Groningen, Groningen, the
Netherlands
3
Center of Nuclear Medicine, University of Sao Paulo, University of Sao Paulo
Medical School, Sao Paulo, Brazil
4
Nutricia Advanced Medical Nutrition, Nutricia Research, Utrecht, the
Netherlands
5
Department of Molecular Neurobiology, University of Groningen, Groningen,
the Netherlands
Abstract
Objectives: Multiple Sclerosis (MS) is an inflammatory neurodegenerative disease
characterized by inflammatory and demyelinated lesions in the brain. Microglia Activation
(MA) occurs during both de- and remyelination. Traditionally MA is associated with myelin
loss, but recent evidence suggests a supportive function of MA during remyelination.1
Monitoring MA and myelin content in vivo would provide a powerful tool to assess remyelination enhancing treatments during MS. In this study we aim to investigate whether it
is possible to monitor MA and myelin status, over time, during de- and remyelination, in
vivo, in the cuprizone mouse model for MS.
Methods: Eight-week-old male C57BL6/J mice were exposed to 0.2% cuprizone for 5.5
weeks to induce demyelination. Thereafter remyelination was allowed to occur. MA was
measured by [11C]PK11195 PET imaging at 7 time points: just before the start of cuprizone exposure (baseline); 3, 4 and 5 weeks after the onset of cuprizone exposure (demyelination); and 1, 2 and 5 weeks after the end of cuprizone exposure (remyelination).
[11C]MEDAS scans were performed at the end, and 5 weeks after the end of cuprizone
exposure, to measure CNS myelin content. Control [11C]MEDAS uptake was measured in
an age matched control group.2
Results: We found a strong and significant increase in brain [11C]PK11195 uptake
during demyelination, peaking 5 weeks after the onset of cuprizone exposure. During remyelination [11C]PK11195 uptake was initially still increased, but progressively
decreased. Five weeks after remyelination onset [11C]PK11195 uptake was statistically
indistinguishable from baseline. The [11C]MEDAS scans confirmed de- and remyelination
in the CNS.
45
Conclusion: We show that [11C]PK11195 PET imaging can be used to longitudinally
monitor MA during demyelination and remyelination in the mouse brain. We also show
that MA associated with remyelination is present and detectable at least 3 weeks into
the remyelination phase. This provides a window for neuroinflammation modulating
treatments, aimed at enhancing remyelination. Combination of [11C]PK11195 and [11C]
MEDAS PET imaging may be a powerful instrument for monitoring MS disease progression and treatment effects on MA and CNS myelin content in MS.
Research support: STW project 11650
References:
1
Olah, M. et al., Glia 60, 306–321 (2012).
2
De Paula Faria, D. et al., NeuroImage doi:10.1016/j.neuroimage.2013.10.057
46
Session 8
Latest insights form UHasselt
Chair: Prof.dr. Jack van Horssen
Department of Molecular Cell Biology and Immunology, VU University Medical Center,
1007MB, Amsterdam, The Netherlands.
Inez Wens
Disturbed skeletal muscle cell biochemistry and composition in multiple sclerosis
Authors Inez Wens, Dominique Hansen, Kenneth Verboven, Frank Vandenabeele, Bert
O. Eijnde
Affiliation REVAL Rehabilitation research center, BIOMED Biomedical research center,
Hasselt University, Martelarenlaan 42, 3590 Hasselt, Belgium
Abstract
BACKGROUND+OBJECTIVE: MS patients are confronted with reduced muscle strength,
decreased aerobic capacity and impaired muscle oxidative capacity. In accordance, a
smaller m. vastus lateralis type I and II skeletal muscle fiber cross sectional area and
a selective type II(a) atrophy were recently reported by our research group. Preliminary
data suggest that this type II atrophy may be associated with a fiber type specific decline
in satellite cells in MS patients. AMP-activated protein kinase (AMPK) is one of the key
skeletal muscle kinases which mediates muscle biochemistry and composition in humans.
To explore the etiology for the development of the MS muscle phenotype, muscle AMPK
phosphorylation was researched.
METHODS: After assessment of body composition, muscle strength and exercise tolerance, muscle fiber type and muscle phospho-AMPKa (m.vastus lateralis biopsy) were
assessed in 14 MS patients and 10 healthy controls.
RESULTS: Increased muscle phospho-AMPKa concentrations were present in MS
(p<0.01) and independently related to MS, despite decreased exercise tolerance and
muscle fiber characteristics. Correlations between muscle phospho-AMPKa and wholebody fat mass, peak oxygen uptake, and expanded disability status scale (p<0.05) were
found.
CONCLUSIONS: Based on these results, it could be hypothesized that inappropriate
downstream signalling after muscle AMPKa phosphorylation occurs in MS. In addition,
muscle signalling cascades for mitochondrial biogenesis seems altered in MS and related
to the impairment and disability level. These findings indicate a link between muscle
signalling cascades and the level of disability and impairment, and thus may open a new
area for the development of novel therapies for peripheral muscle impairment in MS.
47
Marjan Vanheusden
Does CMV trigger CD4+CD28null T-cell expansion in the context of MS?
Authors Marjan Vanheusden1, Suzanne Welten², Bieke Broux1, Liesbet M. Peeters1,
Ramon Arens², An Goris3, Piet Stinissen1, Niels Hellings1
Affiliation 1Hasselt University, Biomedisch Onderzoeksinstituut, School of Life Sciences,
Diepenbeek, Belgium.
2
Leiden University Medical Center, Department of Immunohematology and
Blood Transfusion, Leiden, The Netherlands.
3
KULeuven, Laboratory for Neuroimmunology, Section of Experimental
Neurology, Leuven, Belgium.
Abstract
BACKGROUND: Cytotoxic CD4+CD28null T-cells arise during chronic activation of the
immune system, in a subset of healthy controls (HC) and patients with multiple sclerosis
(MS), a disabling autoimmune disease of the central nervous system. CD4+CD28null T-cells
may contribute to MS, since they accumulate in active lesions and at least a subpopulation is autoreactive in nature.
OBJECTIVE: Investigate whether CMV triggers CD4+CD28null T-cell expansion and what
their role is in the context of MS.
METHODS: An association study between CMV serology and CD4+CD28null T-cells in MS
patients and HC was performed. In an in vitro assay, PBMCs from HC were stimulated with
CMVpp65 and/or IL-2 to mimic chronic CMV stimulation. In vivo, splenocytes from CMV-infected mice were isolated at different time points and analysed via flow cytometry. Furthermore, CD4+CD28null T-cells were studied in experimental autoimmune encephalomyelitis
(EAE) and the role of CMV and these cells in CMV infected EAE mice was examined.
RESULTS: The association study showed that CD4+CD28null T-cells are increased in
CMV+ donors (p<0.0001) and CMV IgG titers correlated with these cells (ρs=0.6,
p<0.0001).
In vitro stimulation of PBMCs with CMVpp65 +/- IL-2 led to increased CD4+CD28null
T-cells in CMV+ HC with in vivo expanded CD4+CD28null T-cells. In CMV infected mice,
there is a significant increase of CD4+CD28null T-cells over time (p<0.001).
In EAE, CD4+CD28null T-cells were significantly higher compared to control mice. Furthermore, CD4+CD28null T-cells positively correlated with clinical score (ρs=0.42, p=0.008).
CMV infected EAE mice had a worse disease course compared to EAE alone (mean cumulative score, p<0.01). At day 30, the percentage of CD4+CD28null T-cells was higher in the
CMV+EAE group compared to CMV or EAE alone. CD4+ T-cell responses against MOG are
higher in the CMV+EAE group compared to EAE alone (p<0.01).
48
CONCLUSIONS: CMV expands CD4+CD28null T-cells via repeated antigenic challenge
and thereby aggravates MS disease. Further studies are warranted, but CMV vaccination
to prevent CMV infection and these expansions might be beneficial for people at risk of
developing MS.
Tim Vanmierlo
The role of LXRβ in neuroinflammation
Authors T. Vanmierlo*, J. Vanmol* J.F.J. Bogie*, S. Timmermans, K. Nelissen,
K. Wouters, H.E. de Vries, J.Å. Gustafsson, K.R. Steffensen, P. Stinissen,
N. Hellings, and J.J.A. Hendriks
*equal contribution
Affiliation Hasselt University
Abstract
Liver-X-receptors (LXRs) are master regulators of cholesterol turnover and of inflammatory responses. Whereas LXRa is mainly expressed in liver, adipocytes, and immune
cells, LXRβ is ubiquitously expressed, being the most prominent isoform in the CNS.
Recent findings demonstrated that pan-LXR agonists ameliorate the disease course of
experimental autoimmune encephalomyelitis (EAE), the animal model for inflammatory
demyelination in multiple sclerosis (MS). Moreover, we previously reported that activation
of LXRs by myelin induces a beneficial phenotype in macrophages by suppressing pro-­
inflammatory mediator production. Here, we determined the contribution of endogenous
LXR activation to a neuroinflammatory response by inducing EAE in mice deficient for
the LXRa or the LXRβ isoform. Surprisingly, in mice deficient for LXRβ, disease severity
and neuroinflammation were strongly reduced in the early disease stages, which was not
seen in LXRa deficient mice. This indicates that LXRβ activation can promote neuroinflammation. LXRb deficient mice subjected to EAE display less immune cell infiltration
as well as a reduced chemokine production in the CNS. Moreover, this phenotype was
independent of LXRb expression in peripheral immune cells. In line with these findings,
an LXR agonist induced the expression of chemokines in a microglia, pointing towards a
prominent role for microglia in the effect LXRb has on neuroinflammation. These findings
indicate that endogenous LXRb activation controls immune cell infiltration into the CNS
by inducing chemokine expression in microglia.
49
Session 9
Grey Matter Pathology in MS
Chair: dr. Inge Huitinga
Department of Neuroimmunology, Netherlands Institute for Neuroscience, Meibergdreef
47, 1105 BA, Amsterdam, The Netherlands
Abstract
Analysis of more than 4000 tissue blocks sampled through the brains of more than 200
MS patient that came to autopsy in the framework of the NBB revealed a high heterogeneity in lesions distribution and lesion activity between MS patients. Many patients
have both white matter and cortical grey matter MS lesions, but some have no cortical
grey matte lesions. Interestingly, we found profound gender differences in MS pathology. Significantly more male MS patients have cortical grey matter lesions and a higher
active white matter lesion load as compared to females. These pathological features are
compatible with the clinical finding that, although less males as compared to females
develop MS, males develop more clinically severe MS and males also have more frequently cognitive impairment. Analysis of tissue blocks dissected from the brain stem and hippocampus revealed the presence of a high incidence of mixed white-grey matter lesions.
These findings urge further investigation of MS pathology in the cortex and the deep grey
matter. Maarten Kole will present a study on changes in axon excitability and expression
in anchoring markers (Ankyrin-G, bIV-spectrin) as well as the main axonal voltage-gated
ion channels (Nav1.6, Nav1.2, Pan-Nav and Kv7.3) in cortical layer V in cuprizone induced demyelination.1-4 Valeria Ramaglia will present a study on complement associated
changes in neurons, axons and synapses in deep grey matter lesions in MS.5,6
1
2
3
4
5
6
50
attefeld A, Tran BT, Gavrilis J, Cooper EC, Kole MH.Heteromeric Kv7.2/7.3 channels
B
differentially regulate action potential initiation and conduction in neocortical myelinated axons. J Neurosci. 2014; 34:3719-32
Hallermann S, de Kock CP, Stuart GJ, Kole MH. State and location dependence of
action potential metabolic cost in cortical pyramidal neurons. Nat Neurosci. 2012 Jun
3;15(7):1007-14.
Kole MH, Stuart GJ. Signal processing in the axon initial segment. Neuron. 2012;
73:235-47.
Kole MH. First node of Ranvier facilitates high-frequency burst encoding. Neuron.
2011;71:671-82.
Michailidou I1, Willems JG, Kooi EJ, van Eden C, Gold SM, Geurts JJ, Baas F, Huitinga
I, Ramaglia V.Complement C1q-C3 associated synaptic changes in multiple sclerosis
hippocampus. Ann Neurol. 2015 Feb 27.[Epub ahead of print]
Ramaglia V, Jackson SJ, Hughes TR, Neal JW, Baker D, Morgan BP. Complement activation and expression during chronic relapsing experimental autoimmune encephalomyelitis in the Biozzi ABH mouse. Clin Exp Immunol. 2015 Jan 23. [Epub ahead of print]
Maarten Kole
Experimental demyelination causes neuronal hyperexcitability
Authors Mustafa S. Hamada1 and Maarten H.P. Kole1,2
Affiliation 1Department of Axonal Signaling, Netherlands Institute for Neuroscience,
Royal Netherlands Academy of Arts and Sciences, 1105 BA, Amsterdam, The
Netherlands.
2
Cell Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The
Netherlands
Abstract
BACKGROUND+OBJECTIVE: Axonal myelination and voltage-gated ion channel clustering
at the nodes of Ranvier are key components for the rapid saltatory conduction of action
potentials. Whether myelination also influences the structural organization of the axon
initial segment (AIS) and action potential initiation is, however, poorly understood. Since
layer 5 axons in the gray matter of the sensory cortex are typically densely ensheathed
with myelin we investigated their structural and functional properties in a toxin demyelination model.
METHODS: Male mice were fed 0.2% – 0.3% cuprizone for 5 – 9 weeks to induce demyelination. Layer 5 pyramidal neurons in acute brain slices of the neocortex were filled
with Alexa Fluor or biocytin during whole-cell recording and intrinsic excitability including
action potential firing was measured. Slices were subsequently stained for intracellular
markers, myelin protein (MBP), anchoring markers (Ankyrin-G, bIV-spectrin) as well as the
main axonal voltage-gated ion channels (Nav1.6, Nav1.2, Pan-Nav and Kv7.3) allowing
correlative analysis of ion channels with the functional recordings.
RESULTS: Layer 5 neurons with demyelinated axons showed increased intrinsic excitability, characterized by larger amplitude and increased frequency of spontaneous
suprathreshold depolarizations (P < 0.0003) as well as antidromically propagating action
potentials ectopically generated in distal parts of the axon (P < 0.005, 27 out of 178 axons). Immunofluorescence examination of demyelinated axons showed that bIV-spectrin,
Nav1.6 and the Kv7.3 channels in nodes of Ranvier either dissolved or extended into the
paranodal domains. In contrast, anchoring proteins and ion channel expression in AISs
were maintained and the intrinsic capacity for single action potential generation was only
marginally affected.
CONCLUSIONS: These results suggest that myelin loss has a differential impact on AISs
and nodes, even within the same demyelinated axon. The functional implications of
demyelination is an hyperexcitability of single cells and neural circuits. We hypothesize
that myelin loss-induced aberrant excitability comprises a cellular correlate of cognitive
impairments in MS.
51
Valeria Ramaglia
Complement C1q-C3 associated synaptic changes in multiple sclerosis hippocampus
Authors Iliana Michailidou1, Janske G.P. Willems1,2, Evert-Jan Kooi3, Corbert van
Eden2, Stefan M. Gold4,5, Jeroen J.G. Geurts3, Frank Baas1, Inge Huitinga2,
Valeria Ramaglia1,2*
Affiliation 1Department of Genome Analysis, Academic Medical Center, Meibergdreef 9,
1105 AZ Amsterdam, The Netherlands;
2
Department of Neuroimmunology, Netherlands Institute for Neuroscience,
Meibergdreef 47, 1105 BA, Amsterdam, The Netherlands;
3
Department of Anatomy & Neurosciences, VU University Medical Center, De
Boelelaan 1118, 1081 HV, Amsterdam The Netherlands;
4
Center for Molecular Neurobiology, University Medical Center Hamburg
Eppendorf, Hamburg, Germany;
5
Department of Psychiatry, Charité, Berlin, Germany
Abstract
BACKGROUND+OBJECTIVE: Multiple sclerosis (MS) is a demyelinating disease of the
central nervous system, leading to memory impairment in up to 65% of patients. Memory
dysfunction in MS has been associated with loss of synapses in the hippocampus, but
its molecular basis is unknown. Accumulating evidence suggest that components of the
complement system, C1q and C3, can mediate elimination of synapses.
METHODS: To investigate the involvement of complement in synaptic changes in MS,
gene and protein expression and localization of C1q and C3 were analyzed in relation to
neuropathological changes in myelinated and demyelinated hippocampi from post-mortem MS brains. Findings were compared to hippocampi of Alzheimer’s disease (AD) and
non-neurological controls.
RESULTS: C1q expression and C3 activation were increased in myelinated and demyelinated MS hippocampi, mainly in the CA3/2 and CA1 subfields, which also showed a marked
decrease in synaptic density and increased neuronal staining for the mitochondrial heat
shock protein 70 (mtHSP70) stress marker. Neurons were the major source of C1q mRNA.
C1q protein and activated C3 localized at synapses within HLA-positive cell processes
and lysosomes, suggesting engulfment of complement-tagged synapses by microglia. A
significant association (p<0.0001) between the density of C1q and synaptophysin-positive
synapses or mtHSP70 was seen in myelinated MS hippocampi, further pointing towards a
link between the complement pathway and synaptic changes. In contrast to AD, MS hippocampi were consistently negative for the terminal complement activation complex C5b9.
CONCLUSIONS: These data support a role for the C1q-C3 complement axis in synaptic
alterations in the MS hippocampus.
52
HOT TOPIC
Cognition in MS: From molecules and imaging towards cognitive
interventions
Chair: Prof.dr. Jeroen Geurts
Department of Anatomy and Neuroscience, Neuroscience Campus Amsterdam, VU University Medical Center, The Netherlands
Abstract
Cognitive impairment occurs in up to 70% of all patients with MS. These cognitive symptoms can influence the patients’ life significantly, varying from minor impairments in daily
living to social isolation and unemployment.
The neurobiological changes that cause cognitive impairment in MS are still largely
unknown. Conventional MRI (i.e. white matter lesion volume, overall brain volume) is too
unspecific to understand the presence of cognitive impairment. Stronger correlations can
be detected between cognitive impairment and grey matter pathology (i.e. the number of
cortical lesions and (deep) grey matter atrophy).
Additionally, the use of more advanced imaging techniques, such as functional MRI (i.e.
brain activation, brain connectivity) has helped to better understand cognitive decline
in MS. These studies suggest that structural damage in the brain may induce a variable
extent of functional reorganisation as a token of brain plasticity, which may ‘mask’ clinical
symptoms. Additionally, we can now measure the brain network efficiency of individual
patients, which strongly relates to cognitive performance.
Although the understanding of cognitive impairment in MS has advanced substantially
over the last years, at least two major challenges need to be addressed so that we can
move from the current situation towards actual cognitive rehabilitation:
1. Further understanding of cognitive decline in MS
To improve our understanding of cognitive decline in MS even further, we have to study
histopathological correlates of network efficiency, such as synapses, glutamate and
GABA. Additionally, we need to study the time course of cognitive impairment in MS, by
obtaining longitudinal follow-up information in vivo. Together, these research lines may
provide us with more information on what induces the ‘tipping point’, i.e. the moment
that cognitively preserved MS patients become cognitively impaired, which could lead to
future intervention studies.
2. Start cognitive rehabilitation
While we need to expand our understanding of the temporal dynamics and histopathological changes suggestive for cognitive decline in MS, we should simultaneously start
exploring potential candidates for cognitive rehabilitation. The key question will be
53
whether it is possible to influence cognitive performance beneficially via several rehabilitation strategies, such as cognitive training, pharmacological intervention and transcranial
magnetic stimulation.
-B
enedict RH, Zivadinov R. Risk factors for and management of cognitive dysfunction in
multiple sclerosis. Nat Rev Neurol 2011 Jun;7:332-342.
- Rao SM, Leo GJ, Bernardin L, Unverzagt F. Cognitive dysfunction in multiple sclerosis. I.
Frequency, patterns, and prediction. Neurology 1991;41:685-691.
- Houtchens MK, Benedict RH, Killiany R, et al. Thalamic atrophy and cognition in multiple sclerosis. Neurology 2007 Sep 18;69:1213-1223.
- Mainero C, Caramia F, Pozzilli C, et al. fMRI evidence of brain reorganization during
attention and memory tasks in multiple sclerosis. Neuroimage 2004 Mar;21:858-867.
- Rocca MA, Ceccarelli A, Rodegher M, et al. Preserved brain adaptive properties in patients with benign multiple sclerosis. Neurology 2010 Jan 12;74:142-149.
- Rosti-Otajarvi EM, Hamalainen PI. Neuropsychological rehabilitation for multiple sclerosis. Cochrane Database Syst Rev 2011;CD009131.
- O’Brien AR, Chiaravalloti N, Goverover Y, DeLuca J. Evidenced-based cognitive rehabilitation for persons with multiple sclerosis: a review of the literature. Arch Phys Med
Rehabil 2008 Apr;89:761-769.
- Hulst HE, Schoonheim MM, Roosendaal SD, et al. Functional adaptive changes within
the hippocampal memory system of patients with multiple sclerosis. Hum Brain Mapp
2012 Oct;33:2268-2280.
- Schoonheim MM, Geurts JJ, Barkhof F. The limits of functional reorganization in multiple sclerosis. Neurology 2010 Apr 20;74:1246-1247.
- Schoonheim MM, Hulst HE, Brandt RB, et al. Thalamus structure and function determine severity of cognitive impairment in multiple sclerosis. Neurology 2015 Feb
24;84(8):776-83.
- Annese J. The importance of combining MRI and large-scale digital histology in neuroimaging studies of brain connectivity and disease. Front Neuroinform 2012 Apr 24;6:13
- Stam CJ, van Straaten EC. The organization of physiological brain networks. Clin Neurophysiol 2012 Jun;123(6):1067-87.
- Verret L, Mann EO, Hang GB, et al. Inhibitory interneuron deficit links altered network
activity and cognitive dysfunction in Alzheimer model. Cell 2012 Apr 27;149(3):70821.
- Bonifazi P, Goldin M, Picardo MA, et al. GABAergic hub neurons orchestrate synchrony
in developing hippocampal networks. Science 2009 Dec 4;326(5958):1419-24.
- Pitt D, Werner P, Raine CS. Glutamate excitotoxicity in a model of multiple sclerosis.
Nat Med 2000 Jan;6(1):67-70.
- Chiaravalloti ND, Moore NB, Nikelshpur OM, DeLuca J. An RCT to treat learning impairment in multiple sclerosis: The MEMREHAB trial. Neurology 2013;81:2066-2072.
54
Menno Schoonheim & Geert Schenk
Understanding cognitive impairment in MS – brain imaging and histopathology
Authors Dr. Menno Schoonheim & Dr. Geert Schenk
Affiliation VU medisch centrum Amsterdam
Abstract
From a research point of view, we still do not fully understand cognitive impairment in
MS. Although recent studies have shown specific functional brain changes in MS that are
cognitively relevant, we still lack critical longitudinal and histopathological data, strongly
limiting the validity of causal claims.
What we have observed is that the brain seems to exhibit a so-called “functional reorganization”. This apparently compensatory response is supposed to limit the functional
impact of structural damage by changing brain function in MS. This was shown in cognitively preserved patients during specific tasks, where we see that some brain regions are
hyperactivated, and that additional regions are recruited. This response is lost in patients
with cognitive impairment.
Besides the local activation patterns of specific structures, we can also look at the
connectivity of individual brain structures, hereby mapping the efficiency of networks in
our brain. As the concept of functional reorganization has gained popularity, scientists
expected to find beneficial increases in connectivity as well as activity in patients with
an intact cognitive performance. Strikingly, virtually all changes in connectivity that have
been found in MS, both increases and decreases, have been linked to cognitive dysfunction. Apparently, there is a normal network balance in the brain, and any change in this
balance will impact cognitive functioning greatly. What is crucially lacking in the field,
however, is longitudinal network imaging.
Furthermore, we critically lack histopathological correlates of connectivity changes in
MS. By studying the normal balance between excitatory and inhibitory inputs and the
structural integrity of individual synapses, we may be able to pinpoint the most important
driver of network dysfunction in MS, in a post-mortem setting. To test this, we can relate
measures of network efficiency, using post-mortem diffusion tensor imaging (DTI) data, to
histopathological markers of synapse efficiency, such as glutamate, GABA and stereological markers.
This session will provide an overview of the current network data in MS, focusing on what
we can and cannot conclude from the current cross-sectional data. To conclude, we will
discuss possible histopathological markers of network efficiency.
55
Neeltje Kant & Hanneke Hulst
Treating cognitive impairment in MS – how to move forward?
Authors Drs. Neeltje Kant & Dr. Hanneke Hulst
Affiliation Nieuw Unicum, Zandvoort / VU medisch centrum Amsterdam
Abstract
From a clinical practice (neuropsychologist), two patients will be presented to the audience. Issues as the most common cognitive deficits in MS and how these cognitive deficits influences the daily functioning of these patients will be discussed. Also, the current
psycho-educational programs and strategies to compensate for deficits that are currently
available will be briefly mentioned.
Although the latter will be able to help to improve the quality of life of patients with MS
suffering from cognitive deficits, it will not give them their original function back (also
called, re-training).
The field of cognitive rehabilitation in MS is currently moving forward. One of the key
questions is whether it will be possible to influence cognitive performance beneficially via
several rehabilitation strategies such as cognitive training, pharmacological intervention,
and transcranial magnetic stimulation. The main goal will be to improve cognitive functioning (i.e. re-train cognitively impaired MS patients) or to prevent cognitive impairment
to occur (i.e. cognitively preserved MS patients).
Until now, cognitive rehabilitation studies in MS are limited and largely report contradicting results. The inconsistency of the results is most likely due to methodological
issues, such as relatively small sample sizes, inadequately defined groups (i.e. too liberal
criteria for cognitive impairment) and incorrect matching. This conclusion was confirmed
by a clinical trial by one of the leading groups in the field, which showed that improved
learning and memory performance as a result of a memory-training program was uniquely
found in moderately cognitively impaired patients. The mildly impaired individuals did not
show any effect from the training. Future studies need to pay careful attention to tackle
these methodological problems.
Novel cognitive interventions and approaches to improve patients cognitive functioning
will be presented. This includes amongst others an 7-week computerized attention training and a dance-cognition intervention.
At the end of this special session on cognition, the audience will be able to describe:
1. the most common cognitive problems MS patients experience;
2. the currently available psycho-educational and compensational strategies;
3. the working hypothesis for cognitive rehabilitation and functional reorganisation;
4. the potential successful cognitive interventions for cognitive impairment in MS.
56
Poster overview
nr
Name and title
1
Navina Chrobok
Tissue Transglutaminase in leukocytes that infiltrate the spinal cord
during experimental multiple sclerosis
59
2
Malou Janssen
A new tool to study antigen specificity of B lymphocytes in the CNS
61
3
Claudio Derada Troletti
Molecular regulation of the Blood-Brain Barrier phenotype
63
4
Claudio Sestito
Regulation of tissue Transglutaminase expression and activity in human
monocytes and macrophages: implication in Multiple Sclerosis
65
5
Kim Meijer
White matter tract abnormalities are associated with cognitive
dysfunction in secondary progressive multiple sclerosis
67
6
Jeroen Bogie
Myelin alters the inflammatory phenotype of macrophages by activating
PPARs and LXRs
69
7
Winde Jorissen
An altered lipoprotein profile underlying disease pathology in a subgroup
of RRMS patients
71
8
Jo Mailleux
Liver x receptor activation in ms lesions
73
9
Mustafa Hamada
Myelin loss induces hyperexcitability of gray matter axons
74
Martijn Steenwijk
Unraveling the relationship between regional gray matter atrophy and
pathology in connected white matter tracts in long-standing multiple
sclerosis
76
11
Liza Rijvers
Increased CLIP expression on CD21low B-cell subsets indicating reduced
HLA-II antigen presentation efficiency in MS
77
12
Anne-Hilde Muris
Vitamin D status does not influence disability progression of multiple
sclerosis patients over three years follow-up
79
13
Jasmine Vanmol
Relation between LXR activation and blood-brain barrier function during
neuroinflammation in multiple sclerosis
80
10
Abstract
on page
57
Poster overview
58
nr
Name and title
Abstract
on p
14
Natalia Ochocka
Differential responsiveness of white and grey matter-derived glial cells
in vitro
81
15
Rosa Boeschoten
Prevalence of Depression and Anxiety in Multiple Sclerosis: A systematic
review
82
16
Arne Battefeld
Satellite oligodendrocytes produce myelin and limit neuronal excitability
by activity-dependent potassium buffering
84
17
Tess Dhaeze
Human circulating follicular regulatory T cells are impaired in multiple
sclerosis
85
18
Karim Kreft
MS risk genes are associated with enhanced EBNA-1 humoral immune
response independent of HLA-DR
87
19
Laura de Bock
Anti-SPAG16 antibodies in multiple sclerosis
88
20
Jordon Dunham
EBV: a new role in MS
90
21
Judith Fraussen
The importance of costimulation and antigen presentation by B cells in
multiple sclerosis
91
22
Benthe Westerik
Sleep problems and cognition in Multiple Sclerosis.
92
23
Quinten van Geest
eMotionS: emotional memory impairment and amygdala activation in
multiple sclerosis
93
Poster Abstracts
P1
Tissue Transglutaminase in leukocytes that infiltrate the
spinal cord during experimental multiple sclerosis
AuthorsNL Chrobok1, ENTP Bakker3, S van der Pol2, HE de Vries2, KK Fenrich4,
F Debarbieux4, MMM Wilhelmus1, C Sestito1, B Drukarch1 and A-M van Dam1
Affiliation
VU University Medical Center,
1
Department of Anatomy and Neurosciences
2
Department of Molecular Cell Biology and Immunology, Amsterdam, The
Netherlands
3
Academic Medical Center, Department of Biomedical Engineering and
Physics, Amsterdam, The Netherlands
4
Institut de Biologie du Developpement de Marseille-Luminy, Université de la
Méditerranée, Marseille, France
Abstract
Background + objective: A pathological hallmark of Multiple sclerosis (MS) is the
infiltration of leukocytes into the central nervous system. They serve as a source of inflammatory mediators contributing to activation of glial cells and further cell recruitment
which ultimately results in demyelination and axonal loss.
One approach to prevent these pathological processes is to avert the infiltration of leukocytes. Tissue Transglutaminase (TG2) is a multifunctional enzyme whose expression and
activity is enhanced during inflammatory processes. TG2 has been shown to be involved
in monocyte adhesion/migration in vitro and we observed increased expression in infiltrated cells in human active white matter lesions.
The aims of this project are to determine (1) if TG2 is of importance for clinical deficits
in a mouse experimental autoimmune encephalomyelitis (EAE) model and (2) to visualize
infiltrating myeloid cells and local microglia in vivo in mouse spinal cord during EAE.
Methods: EAE using MOG35-55 was induced in TG2-/- mice (C57Bl/6) and wildtype littermates. For imaging a permanent window was fixed on top of the spinal cord of CX3CR1-GFP
mice before EAE was induced and followed up by intravital 2-photon microscopy.
Results: We observed that clinical symptoms and the maximal clinical score were significantly reduced in TG2-/- compared to wildtype mice. Using intravital video 2-photon
microscopy, we found numerous GFP positive cells in the white matter around the imaged
blood vessel in the spinal cord. This GFP signal increased during disease course. GFP
positive cells were also found in the circulation as well as crawling on the lumen of blood
vessels. Post-mortem immunohistochemical analysis revealed that various GFP positive
leukocytes had infiltrated the spinal cord. GFP positive cells were co-localizing with macrophages/microglia, and not with T cell markers. In addition, a fraction of the GFP-positive cells showed TG2 immunoreactivity.
59
Poster Abstracts
Conclusions: We conclude that TG2 plays a role in the development of clinical mouse
EAE, and is present in infiltrating leukocytes. TG2 is therefore an interesting potential
therapeutic target in EAE/MS treatment. To further address the role of TG2 in infiltrating leukocytes during EAE, specific inhibitors for TG2 activity will be administered to
CX3CR1-GFP mice. The effects TG2 inhibition on interaction of myeloid cells with spinal
cord endothelium will be visualized using intravital video microscopy.
60
Poster Abstracts
P2
A new tool to study antigen specificity of B lymphocytes in the
CNS
Authors
Malou Janssen1,2, Gijsbert P. van Nierop1,3, Mark J. Kwakkenbos4, Hatice
Orhan1, Marvin M. van Luijn2, Georges M.G.M. Verjans3, Rogier Q. Hintzen2
1
AffiliationDept Neurology, MS center ErasMS, Erasmus MC, University Medical
Centre,Rotterdam.
2
Dept Immunology, MS center ErasMS, Erasmus MC, University Medical
Centre,Rotterdam.
3
Viroscience, Erasmus MC, University Medical Centre,Rotterdam.
4
AIMM therapeutics, Amsterdam
Abstract
Background + objective: Growing evidence suggest B cell involvement in multiple
sclerosis pathology. Clonal populations have been demonstrated intrathecally. These cells
underwent somatic hypermutation, a result of local continuous antigen driven activation.
Until now, it is not known which (auto) antigens drive this process.
In this project, B cells derived from different body compartments of both early and
end-stage MS patients (lesion, NAWM, meninges, CSF and blood) will be immortalized,
enabling us to unravel the antigenic targets of the Ig produced, focusing at both previously suggested suspects and antigen discovery.
Methods: A novel immortalization technique will be applied. B cells are forced to express genes that are normally active in the germinal center reaction:
BCL-xL and BCL-6, to prevent their apoptotic fate and terminal differentiation into plasma cells. The gene construct is coupled to a GFP reporter, enabling detection and sorting
of successfully transduced cells. Co-stimulation for Ig production is provided via IL-21
and CD40L expressing feeder cells. The expression of the B-cell receptor in these immortalized cells is maintained, which enables us to obtain sufficient amounts of Ig from the
original CNS B cells for further characterization and to perform functional studies (e.g.
antigen presenting capacities) using simultaneously generated matched T-cell lines.
Results: Ideally, the immortalization procedure is done after sorting of relevant B-cell
subsets. However, the B cell counts from the compartments we study here are low. Therefore we are at the process of validating the original method without the B cell pre-sorting step, using mixed populations of lymphocyte subsets. In addition, we checked the
reported necessity for pre-activation before the immortalization process, since we want
to prevent activation-induced cell death by ex vivo overstimulation of the already in vivo
activated, quite differentiated B cells. Using both confocal microscopy and cell sorting,
GFP-expressing cells were identified in our cultures, proving successful immortalization of
lymphocytes.
61
Poster Abstracts
Conclusions: With some modifications of the original validated immortalization protocol, we were able to successful immortalize B cells obtained from several compartments.
We have now set the stage for further cell culture and functional characterization of B
cells derived from brain, blood and CSF of MS patients and controls.
62
Poster Abstracts
P3
Molecular regulation of the Blood-Brain Barrier phenotype
Authors:
C. Derada Troletti1, W.W Kamphuis1, A. Reijerkerk2, B. Van Het Hof AJ1,
I.A. Romero3 and H.E de Vries1
1
AffiliationBlood-brain barrier research group, Department of Molecular Cell Biology and
Immunology, Neuroscience Campus Amsterdam, VU Medical Centre, P.O. Box
7057, 1007 MB Amsterdam, The Netherlands
2
Pluriomics therapeutics, Galileiweg 8, 2333 BD Leiden, The Netherlands
3
Biomedical Research Network, The Open University, Walton Hall, Milton
Keynes MK7 6AA, UK
Abstract
Background + objective: Multiple sclerosis (MS) is a progressive inflammatory
disease of the central nervous system (CNS) characterized by inflammation, immune cell
infiltration into the CNS, demyelination and ultimately axonal loss. An early event in MS
is the impairment function of the blood-brain barrier (BBB) which consists of specialized
brain endothelial cells (BECs) supported by surrounding glial cells. Both inflammation
and BBB dysfunction are pathological hallmarks of MS and affect brain homeostasis. Endothelial to mesenchymal transition (EndoMT) is a dynamic process that has been linked
to pathological setting like cancer and fibrosis. During EndoMT, endothelial cells dedifferentiate into mesenchymal cells and as a result lose their tight and adherens junction,
which are essential for the BBB integrity. The EndoMT process is known to be induced
by TGF-β which can upregulate two important transcription factors: Snail1 and Snail2.
Furthermore, recent discoveries unravelled a critical role for microRNAs (miRNA) in controlling the function of the barrier endothelium in the brain. Interestingly, both Snail1 and
Snail2 are both predicted target of miRNA-30c, and we have previously shown that this
miRNA is highly downregulated both in MS patients as well as in inflamed human brain
endothelial cells (hCMEC/D3). We believe that TGF-β can induced EndoMT in BECs and
this event can play an important role in the alteration of the BBB phenotype. Moreover,
we think that a miRNA based approach could restore the normal BBB phenotype by inhibiting the dedifferentiation of the BECs via targeting Snail1 and Snail2.
Methods: To investigate the EndoMT process, hCMEC/D3 were stimulated for 48 hours
with 10ng/ml of TGF-β and IL-1β. qPCR and western blot were used to analyze gene and
protein expression.
Results: Our preliminary data show that TGF-β and IL-1β can induce EndoMT in
hCMEC/D3 which can be demonstrated by the loss of expression of brain endothelial
markers and a gain in expression of mesenchymal markers. Moreover, Snail1 and Snail2
were upregulated in treated hCMEC/D3.
63
Poster Abstracts
Conclusions: Our findings suggest that EndoMT can be involved in the BBB breakdown and participate in the pathogenesis of MS. Moreover, repair of a disturbed BBB
through a specific miRNA approach may represent a novel avenue for effective treatment
of MS.
64
Poster Abstracts
P4
Regulation of tissue Transglutaminase expression and activity
in human monocytes and macrophages: implication in Multiple
Sclerosis
Authors
C Sestito1, JJP Brevé1, PJ van den Elsen2,3, MMM Wilhelmus1, NL Chrobok1, B
Drukarch1 and A-M van Dam1
Affiliation1Department of Anatomy and Neurosciences, VU University Medical Center,
Amsterdam, the Netherlands
2
Department of Pathology, VU University Medical Center, Amsterdam, the
Netherlands
3
Department of Immunohematology and Blood Transfusion, Leiden, the Neth
erlands
Abstract
Background + objective: Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system (CNS). Although the pathogenesis is still not clear, it is
known that leukocytes from the circulation adhere to the brain endothelium and migrate
into the CNS where they can stimulate local glial cells to produce inflammatory factors.
Tissue Transglutaminase (TG2) is a multifunctional enzyme that has been shown to play a
role in monocyte/macrophage adhesion and migration onto extracellular matrix proteins in
vitro, which are processes relevant in MS pathology. Previously, we observed the appearance of TG2 in monocytes in active human post-mortem MS lesions in the CNS. In the
present study we questioned whether TG2 expression and activity were regulated in human monocytes and macrophages by inflammatory mediators and whether TG2 expression
was altered in MS patient-derived monocytes.
Methods: mRNA expression levels in MS patient and control subject derived monocytes were measured by semi-quantitative RT-PCR (qPCR). Human THP1 monocytes and
THP1-derived macrophages were treated with various inflammatory mediators for 24h and
protein and mRNA expression were detected by western blotting and qPCR, respectively.
Moreover, the transglutaminase cross-linking activity was measured by the Covalab assay.
THP1 monocytes were transduced with lentiviral TG2 shRNA to silence TG2 expression
for subsequent functional studies.
Results: TG2 mRNA levels were significantly up-regulated in MS patient-derived monocytes compared to control subject-derived monocytes while Factor XIIIa mRNA levels
remained unaffected. Furthermore, IL-1β mRNA levels were significantly down-regulated
in MS patient-derived monocytes while CD16 and CD14 mRNA levels were significantly
up-regulated. Of interest, TG2 mRNA levels correlated positively with CD16 and with
CD14 mRNA levels. THP1 monocytes and THP1-derived macrophages upregulated TG2
expression after treatment with the anti-inflammatory cytokine IL-4 and not by e.g. LPS.
65
Poster Abstracts
At the functional level, the ability of monocytes to adhere onto fibronectin and the capability of monocyte-derived macrophages to differentiate into anti-inflammatory macrophages (M2a) was reduced when TG2 expression was silenced.
Conclusions: In conclusion, our data show that TG2 in human monocytes and monocyte-derived macrophages is up-regulated by the anti-inflammatory cytokine IL-4, and
suggest that the enhanced TG2 expression in MS patient-derived monocytes might be
mediated by anti-inflammatory stimuli.
66
Poster Abstracts
P5
White matter tract abnormalities are associated with
cognitive dysfunction in secondary progressive multiple
sclerosis
Authors:
Kim A. Meijer1,2, Nils Muhlert2,3, Mara Cercignani4, Varun Sethi2, Maria A.
Ron2, Alan J. Thompson2,5, David H. Miller2,5, Declan Chard2,5, Jeroen J.G.
Geurts1, Olga Ciccarelli2,5
1
Affiliation
Department of Anatomy and Neurosciences, VU University Medical Centre,
Amsterdam, The Netherlands
2
NMR Research Unit, Queen Square MS Centre, University College London
Institute of Neurology, London, United Kingdom
3
School of Psychology and Cardiff University Brain Research Imaging Centre,
Cardiff University, Cardiff, United Kingdom
4
Clinical Imaging Centre, Brighton and Sussex Medical School, Brighton,
United Kingdom
5
NIHR University College London Hospitals Biomedical Research Centre,
London, United Kingdom
Abstract
Background + objective: Whilst our knowledge of white matter (WM) pathology
underlying cognitive impairment in relapsing remitting MS (RRMS) is increasing, equivalent understanding in those with secondary progressive (SP) MS lags behind. This study
examines whether the extent and severity of WM damage within major tracts, independent
of normalized grey matter volume (GM), differs between SPMS patients with and without
cognitive impairment.
Methods: Conventional magnetic resonance imaging (MRI) and diffusion MRI were
acquired from 30 SPMS patients and 32 healthy controls. Cognitive assessment included
comprehensive testing spanning five cognitive domains that are commonly affected in
MS patients. To investigate predictors of cognition in SPMS, backward stepwise linear
regression was used. Patients were defined as cognitively impaired when their cognitive
test score was at least 2 standard deviations (SD) below that of controls on a minimum
of 2 out of 5 tested cognitive domains. Tract based spatial statistics (TBSS) was used to
compare diffusion measures between groups. Furthermore, we mapped the extent and
severity of WM damage. Analyses were adjusted for normalized GM volume.
Results: Cognitive performance in SPMS was significantly predicted by WM integrity,
premorbid IQ and gender (R2 = 0.38, p = 0.001). Relative to healthy controls, SPMS
patients showed a widespread loss of WM integrity, reflected by reduced fractional anisotropy (FA) and elevated axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity
67
Poster Abstracts
(MD), both within and outside hyperintense T2 WM lesions. Out of the 30 SPMS patients,
12 patients were defined as cognitively impaired. More extensive and severe damage
of association fibers, including the fornix, superior longitudinal fasciculus and anterior
thalamic radiation, was observed in cognitively impaired patients, when compared with
cognitively preserved patients.
Conclusions: Cognitive dysfunction in SPMS is associated with more severely and
extensively damaged WM tracts, even after controlling for GM pathology. Damage to association fibres may be particularly important for cognitive function in SPMS patients.
68
Poster Abstracts
P6
Myelin alters the inflammatory phenotype of macrophages by
activating PPARs and LXRs
Authors
Jeroen FJ Bogie1, Winde Jorissen1, Jo Mailleux1, Silke Timmermans1, Vân Anh
Huynh-Thu2, Alexandre Irrthum2, Hubert J. M. Smeets3, Philip G Nijland4,
Noam Zelcer5, Jan-Åke Gustafsson6, Tim Vanmierlo1, Knut R. Steffensen6,
Jack van Horssen4, Monique Mulder7, Piet Stinissen1, Niels Hellings1 and
Jerome JA Hendriks1.
1
AffiliationBiomedical Research Institute, School of Life Sciences, Hasselt University /
Transnational University Limburg, Diepenbeek, Belgium.
2
University of Liège, GIGA-Research, Bioinformatics and Modeling, Liège,
Belgium
3
Department of Genetics en Celbiology, Schools for Cardiovascular Research
and for Oncology and Developmental Biology, Maastricht UMC+, Maastricht,
The Netherlands
4
Department of Molecular Cell Biology and Immunology, VU University
Medical Center, Amsterdam, The Netherlands.
5
Department of Medical Biochemistry, Amsterdam Medical Center,
Amsterdam, The Netherlands.
6
Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm,
Sweden
7
Division of Pharmacology, Vascular and Metabolic Diseases, Department of
Internal Medicine, Rotterdam University, Rotterdam, The Netherlands
Abstract
Foamy macrophages, containing myelin degradation products, are abundantly found in
active multiple sclerosis (MS) lesions. Recent studies have described an altered phenotype of macrophages after myelin internalization. However, mechanisms by which myelin
affects the phenotype of macrophages and how this phenotype influences lesion progression remain unclear. We demonstrate that myelin reduces nitric oxide and IL-6 production by macrophages through activation of peroxisome proliferator-activated receptor β/δ
(PPARβ/δ) and liver X receptor β (LXRβ), respectively. Furthermore, phosphatidylserine,
a phospholipid found in myelin, reduces nitric oxide production through activation of
PPARβ/δ.
In experimental autoimmune encephalomyelitis (EAE), an animal model for MS, uptake
of PS by macrophages suppresses the production of inflammatory mediators and reduces
disease severity. The protective effect of PS in EAE animals is associated with a reduced
immune cell infiltration into the central nervous system and decreased splenic cognate
antigen specific proliferation. Interestingly, PPARβ/δ is activated in foamy macrophages in
MS lesions, indicating that myelin also activates PPARβ/δ in macrophages in the human
69
Poster Abstracts
brain. Our data show that myelin modulates the phenotype of phagocytes by PPAR and
LXR activation, which may subsequently dampen MS lesion progression. Moreover, our
results suggest that myelin-derived PS mediates PPAR activation in macrophages after
myelin uptake. The immunoregulatory impact of naturally-occurring myelin lipids may
hold promise for future MS therapeutics.
70
Poster Abstracts
P7
An altered lipoprotein profile underlying disease pathology in
a subgroup of RRMS patients
Authors
Winde Jorissen1, E. Wouters1, JFJ. Bogie, B. van Wijmeersch2, D. Sviridov3, P.
Stinissen1, N. Hellings1, V. Somers1, T. Vanmierlo1, M. Mulder4, AT. Remaley3
and JJA. Hendriks1
1
Affiliation
Hasselt University, Biomed, Diepenbeek, Belgium
2
Revalidation and MS Center, Overpelt, Belgium
3
NIH, Dept. of Laboratory Medicine, Clinical Center, Bethesda, United States
4
Erasmus MC, Vasc. and Met. diseases, Rotterdam, the Netherlands
Abstract
Background + objective: Macrophages are major effector cells in multiple sclerosis
(MS). Depending on environmental stimuli, more pro- or anti-inflammatory phenotypes of
macrophages occur that contribute to respectively tissue injury or tissue repair processes.
In MS, lipoprotein levels in the blood are altered.
Moreover, an association between plasma lipoprotein levels and neurologic events in MS
patients is reported. Interestingly, lipoproteins influence the inflammatory phenotype of
monocytes in the blood. In atherosclerosis, high density lipoprotein (HDL) is known to
beneficially influence the disease status by inducing cholesterol efflux in macrophages
which is accompanied by an anti-inflammatory phenotype in these cells. In this study
we aim to determine the interaction between changes in lipoproteins in the blood, their
influence on the phenotype and function of monocytes and subsequently on disease
progression.
Methods: Fasting plasma samples were collected from healthy controls, relapsing remitting MS (RRMS) patients and progressive MS patients. Detailed lipoprotein profiles were
determined in plasma samples with NMR spectroscopy.
Plasma samples were converted to serum by defibrination and serum cholesterol efflux
capacity was measured in vitro using 3H cholesterol-labeled baby hamster kidney (BHK)
cells expressing the mifepristone-inducible human ABCG1 transporter. Statistical analyses were performed using SAS by fitting univariate multiple regression models for each
response.
Results: Our data show that RRMS patients but not progressive MS patients have an
atherogenic, diabetic dyslipidemic lipoprotein profile. More specific, RRMS patients with
a low BMI have increased amounts of small HDL particles. This is accompanied with a
higher insulin resistance index and consequently increased levels of triglycerides (TG) and
more and TG-richer VLDL particles. Importantly, the amount of small HDL particles in
RRMS patients with a low BMI was strongly negatively correlated with serum cholesterol
efflux capacity via the ABCG1 transporter.
71
Poster Abstracts
Conclusions: In summary, our data indicate that the lipoprotein profile of a subgroup
of RRMS patients is modified towards a more atherogenic, diabetic dyslipidemic profile
which is associated with a reduced capacity for cholesterol efflux via the ABCG1 transporter.
72
Poster Abstracts
P8
LIVER X RECEPTOR ACTIVATION IN MS LESIONS
Authors:
Jo Mailleux1, Tim Vanmierlo1, Jeroen Bogie1, Elien Wouters1, Piet Stinissen1,
Jerome Hendriks1, Jack van Horssen2
1
AffiliationImmunology & biochemistry, Hasselt University, Diepenbeek
2
Molecular Cell Biology and Immunology, VUmc Amsterdam, Amsterdam
Abstract
Background + objective: Multiple sclerosis (MS) is an autoimmune disease of the
central nervous system (CNS). It is pathologically characterized by infiltrating macrophages that destroy the myelin sheaths. Myelin consists for a large part of cholesterol and
myelin breakdown causes an overload of cholesterol and oxysterols in macrophages. These
oxidized derivatives of cholesterol are able to activate liver X receptors (LXRs), which
will lead to the subsequent induction of genes involved in cholesterol efflux, including
ABCA1, ABCG1 and APOE. Previously, we demonstrated that myelin activates LXRs in
primary murine macrophages.
Methods: In this study we used real-time quantitative PCR (qPCR) and immunohistochemistry (IHC) to determine the expression of LXRs and their response genes in human
phagocytes after myelin phagocytosis and in MS lesions.
Results: Myelin ingestion induced the LXR response genes ABCA1 and ABCG1 in
human monocyte derived macrophages, demonstrating myelin activates LXRs in human
phagocytes. We found that both ABCA1 and APOE gene expression and protein levels
are highly upregulated in active MS lesions compared to healthy controls. MHCII-positive
infiltrating macrophages and microglia in active lesions are positive for ABCA1 and APOE,
indicating LXRs are activated in these myelin phagocytosing cells. LXRα is mainly present
on MHCII+ cells while LXRβ is predominantly observed in perilesional astrocytes.
Conclusions: Our findings indicate that LXRs are activated in phagocytes and perilesional astrocytes in active MS lesions. Future studies are needed to determine the impact
of LXR activation on infiltrating and residential CNS celtypes.
73
Poster Abstracts
P9
Myelin loss induces hyperexcitability of gray matter axons
Authors M.S. Hamada1 and M.H.P. Kole1,2
1
Affiliation
Axonal Signalling Group, Netherlands Institute for Neuroscience, KNAW,
Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
2
Cell Biology, Faculty of Science, University of Utrecht
Abstract
Background + objective: Loss of sodium (Na+) channels at the nodes of Ranvier
and increased lateral expression in internodes are major hallmarks of myelin loss known
to cause impairment of action potential conduction and predisposing axons to injury.
While most previous studies on demyelination focus on white matter fibre tract, the
impact of demyelination on the gray matter and axon initial segment (AIS), which is the
primary site for action potential initiation, remains elusive.
Methods: Here, we used the cuprizone toxin mouse model for gray matter demyelination. Six weeks old male mice were put on 0.2% or 0.3% cuprizone mixed with powder
food for 5 or 9 weeks, respectively. After treatment mice were anaesthetized and parasagittal brain slices were prepared from the cortex. Immuno-labelling of myelin basic
protein (MBP) in the somatosensory cortex revealed that myelin loss was most prominent
in the layers 5 and 6. In order to analyse the functional and structural properties of single
demyelinated neocortical layer 5 axons we combined in vitro electrophysiological recordings with immunofluorescence of the voltage gated ion channels subunits and anchoring
proteins from the same cell.
Results: The anchoring proteins and Na+ channels of the AIS in demyelinated axons
relocated to a more proximal position near the soma. In contrast, the potassium channel
Kv7.3 diffused into the first demyelinated internode. Demyelination was also accompanied by diffuse lateral expression and loss of ion channels around branch points of identified layer 5 axons. Somatic whole-cell current-clamp recordings showed that demyelinated neurons displayed a ~3-fold increase in spontaneous suprathreshold depolarizations as
well as an increase in high-frequency firing. Furthermore, demyelination of layer 5 axons
induced ectopic action potentials, arising in distal parts of the axon, which invaded the
soma in an anterograde direction.
Conclusions: Taken together, this study reveals for the first time that demyelination of
gray matter circuits is accompanied by an increase in intrinsic neuronal excitability and
aberrant network excitation. Hyperexcitability may significantly deteriorate the spatio-temporal structure of information encoding in the neocortex and provides new insights into
the cellular origin of cognitive impairments in multiple sclerosis.
74
Poster Abstracts
This investigation was supported by grants from the National Multiple Sclerosis Society
(RG 4924A1/1) and European Research Council under the European Community’s Seventh Framework Programme (FP7), ERC-StG #261114.
75
Poster Abstracts
P10
Unraveling the relationship between regional gray matter
atrophy and pathology in connected white matter tracts in
long-standing multiple sclerosis.
Authors
Steenwijk MD1; Daams M1,2; Pouwels PJW3; Balk LJ4; Tewarie PK4;
Geurts JJG1,2; Barkhof F1; Vrenken H13
Affiliation
Neuroscience Campus Amsterdam, VU University Medical Center, The
Netherlands
1
Department of Radiology and Nuclear Medicine,
2
Department of Anatomy and Neurosciences,
3
Department of Physics and Medical Technology,
4
Department of Neurology
abstract
Background + objective: Gray matter (GM) atrophy is common in multiple sclerosis
(MS), but the relationship with white matter (WM) pathology is largely unknown. Some
studies found a co-occurrence in specific systems, but a regional analysis across the brain
in different clinical phenotypes is necessary to further understand the disease mechanism
underlying GM atrophy in MS. Therefore, we investigated the association between regional
GM atrophy and pathology in anatomically connected WM tracts.
Methods: Conventional and diffusion tensor imaging was performed at 3T in 208
patients with long-standing MS and 60 healthy controls. Deep and cortical GM regions
were segmented and quantified, and both lesion volumes and average normal appearing
WM fractional anisotropy of their associated tracts were derived using an atlas obtained
by probabilistic tractography in the controls. Linear regression was then performed to
quantify the amount of regional GM atrophy that can be explained by WM pathology in the
connected tract.
Results: MS patients showed extensive deep and cortical GM atrophy. Cortical atrophy
was particularly present in frontal and temporal regions. Pathology in connected WM
tracts statistically explained both regional deep and cortical GM atrophy in relapsing-remitting (RR) patients, but only deep GM atrophy in secondary-progressive (SP) patients.
Conclusions: In RRMS patients, both deep and cortical GM atrophy were associated
with pathology in connected WM tracts. In SPMS patients, only regional deep GM atrophy
could be explained by pathology in connected WM tracts. This suggests that in SPMS
patients cortical GM atrophy and WM damage are (at least partly) independent disease
processes.
76
Poster Abstracts
P11
Increased CLIP expression on CD21low B-cell subsets indicating
reduced HLA-II antigen presentation efficiency in MS
Authors
Liza Rijvers1, Jeanet M. Hogervorst1, Marie-José Melief1, Annet WierengaWolf1, Rogier Q. Hintzen2, Marvin M. van Luijn1
Affiliation
MS Center ErasMS, Erasmus MC, University Medical Center, Rotterdam, The
Netherlands
1
Department of Immunology
2
Department of Neurology
abstract
Background + objective: B-cell depletion with rituximab in MS patients exhibits
a strong therapeutic effect, underlining the central role of B cells in MS. Interestingly,
peripheral but not central B-cell tolerance is defective in MS, leading to an enhanced
activation of B cells. Because B cells are capable of presenting autoantigens and the
HLA class II (HLA-II) locus is the strongest genetic risk factor in MS, we hypothesize
that HLA-II antigen presentation by selected B cell subsets is abnormally regulated in
MS.
Methods: We analysed the class II-associated invariant chain peptide (CLIP)/HLA-DR
surface expression ratio, a measure for antigen presentation efficiency, on 12 B-cell
subsets in peripheral blood of 10 healthy donors, as well as 20 MS patients and 20 ageand gender-matched healthy controls using 12-color flow cytometry. Next, we selected
20 genes associated with MS and autoimmunity, which potentially play a role in antigen
processing and presentation. Relative mRNA levels of these genes were correlated to
CLIP/ HLA-DR expression in 8 EBV+ and 7 EBV- human B-cell lines.
Results: In contrast to other B-cell subsets, high CLIP/HLA-DR ratios were found
in healthy donors especially for B cells with low expression of CD21 (EBV receptor),
including CD38dim (anergic/autoreactive) and CD38highCD24high (transitional) subsets. In addition, CLIP expression on CD21low transitional B-cells of MS patients was
significantly increased compared to CD21high transitional B cells (p<0.05) and naïve
B cells (p<0.0001). CLIP expression was also significantly increased in EBV+ B cell
lines (P=0.011) when compared to EBV- B cell lines. Furthermore, we already found
correlations of several of our selected genes with both the CLIP/HLA-DR ratio and CD21
expression. For example, SPPL2a correlated in EBV+ (R2=0.671, p=0.046; R2=0.637,
p=0.057, respectively), but not EBV- B-cell lines (R2=0.061. p=0.637; R2=0.058,
p=0.645, respectively).
Conclusions: We found a higher CLIP/HLA-DR ratio in CD21low CD38dim and CD21low transitional B cells in MS, suggesting less efficient antigen presentation.
77
Poster Abstracts
The association of CLIP/DR with CD21 and certain risk genes related to HLA-II in EBV+
B-cell lines only warrants further investigation. We will explore whether active modulation
of these risk genes during B cell activation will have an effect on HLA-II antigen presentation efficiency.
78
Poster Abstracts
P12
Vitamin D status does not influence disability progression of
multiple sclerosis patients over three years follow-up
Authors
Anne-Hilde Muris1,2, Joost Smolders2*, Linda Rolf1,2, Lieke Klinkenberg3,
Noreen van der Linden3, Steven Meex3, Jan Damoiseaux3, Raymond Hupperts1,2
1
AffiliationSchool for Mental Health and Neuroscience, Maastricht University Medical
Center, Maastricht, the Netherlands;
2
Academic MS Center Limburg, Orbis Medical Center, Sittard, the
Netherlands;
3
Central Diagnostic Laboratory, Maastricht University Medical Center,
Maastricht, the Netherlands;
*Current address: Department of Neurology, Wilhelmina Canisius Hospital,
Nijmegen, the Netherlands
Abstract
Introduction: The risk of developing multiple sclerosis (MS) as well as MS disease
activity is associated with vitamin D (25(OH)D) status. The relationship between the main
functional disability hallmark of MS, disability progression, and 25(OH)D status is less
well established though, especially not in progressive MS patients.
Material and Methods: This retrospective longitudinal study included MS patients
with a baseline 25(OH)D serum level and Expanded Disability Status Scale (EDSS) with a
minimum follow-up of three years. Logistic and multinominal regression were performed
to assess the effect of baseline 25(OH)D on relapse rate.
Multilevel analyses were performed to assess the effect on disability and disability progression.
Results: 54 patients (61% RRMS, 27% SPMS, 11% PPMS, and a male:female ratio of
29:71) were included. The mean EDSS at baseline was 3.8, with a mean relapse rate of
0.95 and a mean uncorrected 25(OH)D level of 57.5 nmol/L. Baseline deseasonalized
25(OH)D levels predicted subsequent relapse risk (yes/no; OR=0.96, p=0.015) and EDSS
(p=0.005), but did not predict EDSS progression (β=0.00008, p=0.712) whereas MS
phenotype did (β SPMS compared to RRMS=-0.0271, p=0.02).
Discussion and conclusion: 25(OH)D status within the physiological range predicts
the occurrence of relapses and EDSS, but does not contribute significantly to EDSS
progression in established MS. According to our data, only MS phenotype per se predicts
EDSS progression. Whether high dose supplementation to supra physiological 25(OH)D
levels could still help to prevent disability progression in MS should become clear from
long term follow-up of supplementation studies.
Keywords: disease progression, multiple sclerosis, vitamin D
79
Poster Abstracts
P13
Relation between LXR activation and blood-brain barrier
function during neuroinflammation in multiple sclerosis
Authors:J. Vanmol1, T. Vanmierlo1, J.F.J. Bogie1, S.M.A. van der Pol2, W.W. Kamphuis2,
P. Stinissen1, N. Hellings1, H.E. de Vries2, J.J.A. Hendriks1
1
Affiliation
Hasselt University, Biomedical Research Institute, School of Life Sciences,
Diepenbeek, Belgium
2
Department of Molecular Cell Biology and Immunology, Neuroscience Cam
pus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
Abstract
Background + objective: Multiple sclerosis (MS) is a demyelinating disease of the
central nervous system (CNS), featured by an early disruption of the blood-brain barrier
(BBB). Cerebral endothelial cells (CECs) tightly regulate BBB function and are regarded
as the gatekeepers of the CNS. Changes in BBB properties comprise alterations in the
tight and adherens junctions, differences in CEC adhesion molecule expression, and
modulated chemoattraction of leukocytes. At the crossroads of linking metabolic and
inflammatory responses are the liver X receptors (LXRs). In this study, the effect of LXR
activation on CEC function is determined.
Methods: The effect of inflammatory stimuli (interferon y (IFN-y) and tumor necrosis
factor a (TNF-a)) in combination with the LXR agonist GW3965 is studied in vitro in the
human brain endothelial cell line hCMEC/D3 and ex vivo in primary CECs isolated from
wild type and LXRa or LXRb isoform knockout mice using dextran gradient centrifugation.
Modulation of BBB properties and pro-inflammatory chemoattractants are quantified by
real-time PCR.
Results: In vitro, LXR activation in hCMEC/D3 suppresses the cell surface expression of
the adhesion molecules ICAM-1 and VCAM-1 in a dose-dependent manner. Furthermore,
the expression of CXC chemokines is reduced in hCMEC/D3 following LXR activation. Ex
vivo, LXR response genes (ABCA1 and ABCG1) show less upregulation after LXR activation in CECs isolated from LXRb isoform knockout mice compared to LXRa isoform
knockout and wild type mice.
Conclusions: Under inflammatory conditions, BBB properties are positively affected
by the activation of LXRs in CECs. The suppression of adhesion molecule expression and
chemoattraction by an LXR agonist provides an anti-inflammatory environment leading
to reduced leukocyte extravasation into the CNS. LXRb appears the main LXR isoform in
CECs confirming the importance of LXR subtype-specific research.
80
Poster Abstracts
P14
Differential responsiveness of white and grey matter-derived
glial cells in vitro
Authors
Natalia Ochocka, John Brevé, John Bol, Benjamin Drukarch and Anne-Marie
van Dam
Affiliation
VU University Medical Center, Neuroscience Campus Amsterdam, Department
of Anatomy and Neurosciences, Amsterdam, The Netherlands
Abstract
Background + objective: It is known that Multiple Sclerosis (MS) affects both white
matter (WM) and grey matter (GM). Nevertheless, the immunopathology observed in those
regions differs e.g. in a number of leukocytes that highly infiltrate WM, but not GM and
increased level of nitric oxide (NO) resulting in nitrozative damage of WM, which is not
seen in GM. This can be due to local differences in responsiveness of glial cells, resulting
in a differential inflammatory environment. In the present study we aim to dissect the
responsiveness of white and grey matter-derived glial cells in vitro.
Methods: Primary glial cells were derived at postnatal day 1-2 from striatum (enriched
white matter) and cerebral cortex (enriched grey matter) of Wistar rats. After 4 or 10 days
in culture, the cells were treated with various doses of lipopolysaccharide (LPS; E.coli
055B5) for 24h and examined for the expression of inflammatory markers (IL-1β, IL-10,
iNOS). In addition, isolated microglial cells will be exposed to astrocyte conditioned
medium or plated upon an astrocyte monolayer to determine whether astrocyte-derived
factors and/or cell-cell contact is essential for their response.
Results: Thus far, glial cells derived from both striatum and cortex strongly upregulated
the pro inflammatory markers (iNOS, IL 1β) when stimulated with LPS after 4 days in
culture. However, after day 10 the expression was retained at the high level only in the
striatum-derived culture, and reduced in the cortex-derived culture. On the contrary, the
expression of anti-inflammatory marker IL-10 was increased in both cultures after day 4,
but only cortex-derived culture showed further increase after day 10. The result is coupled
with persistent ameboid morphology of striatal microglia, whereas the cortical microglia
adopts a ramified morphology in time.
Conclusions: The consistent expression of inflammatory mediators together with an
amoeboid morphology of microglia suggests a more pro-inflammatory profile of glial cells
in white matter, compared to GM-derived glial cells that show down-regulation of inflammatory mediators, up-regulation of the anti-inflammatory mediator and adapt the ramified
phenotype. These data imply a differential responsiveness of white versus grey matter-­
derived glial cells that may contribute to the differential immunopathology observed in
MS lesions.
81
Poster Abstracts
P15
Prevalence of Depression and Anxiety in Multiple Sclerosis:
A systematic review
Authors:
Rosa Boeschoten1,2, Annemarie Braamse1,2, Joost Dekker1,2,4, Patricia van
Oppen1,2, Aartjan Beekman1,2, Bernard Uitdehaag3
1
AffiliationDepartment of Psychiatry, VU University Medical Center and GGZinGeest,
Amsterdam, Netherlands.
2
EMGO Institute for Health and Care Research, VU University, Amsterdam,
Netherlands
3
Department of Neurology, VU University Medical Center, Amsterdam,
Netherlands
4
Department of Rehabilitation Medicine, VU university Medical Center,
Amsterdam, Netherlands
Abstract
Background + Objectives: Emotional disorders such as depression and anxiety are
common in patients with Multiple Sclerosis (MS) and among the most important factors
affecting quality of life. Prevalence rates of depression and anxiety in MS vary widely
across studies that differ in settings, sample sizes and diagnostic approaches. Taking into
account these differences, this systematic review aimed at calculating the average prevalence of depression and anxiety in MS.
Methods: A systematic review of available publications obtained via a computerized
search in Medline, EMBASE, Psycinfo and the Cochrane library for studies of depression
and anxiety in MS was executed. The literature search identified 2329 articles published
between 1979 and December 2014 which were systematically reviewed. English written
studies that identified prevalence of depressive disorders and anxiety disorders or clinical
significant symptoms in 200 or more outpatients with MS, age >15 years, were included,
resulting in 59 articles.
Findings: Results showed a weighted prevalence for depressive disorder of 21.7% (95%
CI=16.4%-28.2%) and anxiety disorder of 13.0% (95% CI=7.7%-21.1%). Clinically
significant depressive symptoms were present in 34.9% (95% CI=30.0%-40.1%) and
clinically significant anxiety symptoms in 35.5% (95% CI=26.1%-46.3%). Further analyses showed that taken together, studies using DSM criteria/ ICD-codes and no structured
interview to diagnose depression, displayed a significantly lower prevalence rate compared
to studies using (semi) structured interviews to establish DSM criteria (p<0.5). Population
studies reported a similar prevalence rate for depression disorder but higher prevalence
rate for clinically depressive symptoms compared to studies in clinical settings.
82
Poster Abstracts
Conclusions: This review shows that the average prevalence of depression and anxiety
in MS is substantial and should be a point of concern. However, due to methodological
differences between studies results should be interpreted with caution.
83
Poster Abstracts
P16
Satellite oligodendrocytes produce myelin and limit neuronal
excitability by activity-dependent potassium buffering
Authors Arne Battefeld­, Jan Klooster1, Maarten HP Kole1,2
1
Affiliation
Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal
Academy of Arts and Sciences, Meibergdreef 47, 1105 BA, Amsterdam.
2
Cell Biology, Faculty of Science, University of Utrecht, 3584 CH, Utrecht.
Abstract
Background + objective: The gray matter contains a large numbers of oligodendrocytes. In the deeper layers of the cortex oligodendrocytes are abundant and they myelinate mainly axons of projection neurons. Intriguingly about ~35% of oligodendrocytes can
be found in direct contact with cell bodies of pyramidal neurons. These oligodendrocytes
are described as ‘perineuronal’ or ‘satellite’ oligodendrocytes (sOLs) that are not myelinating axons but rather metabolically supporting and protecting neurons from apoptosis.
Their unique position makes them an excellent target to investigate neuron-oligodendrocyte interactions in the grey matter. Here, we hypothesized that sOLs can detect and
influence action potential firing due to their proximity to neurons.
Methods: We combined whole-cell patch-clamp recordings and live confocal imaging
of neuron-sOL pairs in acute neocortical slices from adult mice (wild-type or PLP-ECFP
reporter mice) allowing morphological and physiological characterization. Immunohistochemical analyses and electron microscopy of single sOLs was performed post-hoc to
identify protein expression and assess myelination. Computational modeling of neuron-glia interactions was based on published models.
Results: We found that sOLs myelinated on average 32 surrounding axons with ~4
myelin layers. Interestingly, in response to action potentials sOLs displayed time locked
inward currents with an amplitude of –16 ± 2 pA (n = 16). Inward currents were selectively reduced to 20% of control values by 100 µM barium, which is a blocker of Kir
channels. Immunohistochemical and immuno-gold electron microscopy revealed somatic
expression of Kir4.1. Computational modeling showed that during action potential firing
the largest source of potassium release is the peri-somatic region of the neuron. Moreover,
both computational modeling and in vitro experiments demonstrated that during repetitive firing sOLs can constrain the generation of during periods of high-frequency firing by
rapidly buffering the extracellular potassium.
84
Conclusions: Our data show that sOLs unexpectedly produce myelin similar to other
grey matter oligodendrocytes. Expression of Kir4.1 at the cell body and their direct apposition to pyramidal neurons plays a role in limiting hyper-excitability of the host neurons.
These data suggest that neuron-oligodendrocyte interactions are critical for maintaining
activity levels in the cortex.
Poster Abstracts
P17
Human circulating follicular regulatory T cells are impaired
in multiple sclerosis
Authors
Tess Dhaeze1; Evelyn Peelen1; Stéphanie D’Hondt2; Nele Claes1; Anneleen
Hombrouck3; Liesbet Peeters1; Bart Van Wijmeersch1,4; Isabelle Thomas3;
Peter Lemkens5; Bieke Broux1; Sophie Lucas2; Veerle Somers, Piet Stinissen1;
Niels Hellings1
1
Affiliation
Hasselt University, Biomedical Research Institute and Transnationale
Universiteit Limburg, School of Life Sciences, Diepenbeek, Belgium
2
de Duve Institute, Université catholique de Louvain, Brussels, Belgium
3
Scientific Institute of Public Health, Operational Direction of Transmitted and
Infectious Diseases, Virology Unit, Brussels, Belgium
4
Rehabilitation & MS-Center, Overpelt, Belgium
5
Hospital East-Limburg (ZOL), Campus Sint-Jan, Genk, Belgium
Abstract
Background + objective: Both autoreactive T cells and autoantibodies are identified as key players in the immunepathogenesis of multiple sclerosis (MS). These overt
autoimmune responses may result from disturbances in regulatory T cells important for
the maintenance of peripheral tolerance. Recently a new subset of regulatory T cells was
discovered in mice. Follicular regulatory T cells (TFR, CD4+CXCR5hiPD-1hiFoxP3+) participate in germinal responses by controlling the maturation of B cells and the production
of (auto)antibodies. The aim of this study was to asses impairments in frequency and
function of TFR in patients with MS.
Methods: First, a side by side comparison is made of TFR derived from lymphoid tissue
(tonsils) and peripheral blood (PB) of healthy donors (HC) to demonstrate whether blood
is an appropriate source to study TFR. Next, frequency, phenotype and function is defined
of circulating TFR of MS patients in comparison to those of HC.
Results: We found that circulating TFR comprise a distinct population in humans. They
express both follicular (CXCR5+PD-1+SAP+) and regulatory markers (Foxp3 and Helios). In addition, they display a memory phenotype (CD45RO+CD45RA-CCR7+) but are
not considered bona fide TFR as they do not express BCL-6 and ICOS. Next, to identify
their functional relevance the effect of influenza vaccination was assessed. We show that
TFR frequencies increase after influenza vaccination and correlate with anti-flu antibody
responses. To assess their suppressive capacity their function was compared with tonsil
derived TFR. Both the suppressive function and the FOXP3 methylation status did not
differ between both populations indicating a fully functional circulating population.
A significantly decreased TFR frequency (p=0.0011) was found in untreated MS patients (0.1151 ± 0.008784 % of CD4+, n=96) compared to HC (0.1658 ± 0.01235
85
Poster Abstracts
% of CD4+, n=47). Furthermore, the frequency of circulating Th17-like TFR cells was
increased. Also, an impaired suppressive function of TFR from MS patients was found.
Conclusions: These results suggest that it is eligible to study circulating TFR to investigate alterations in autoimmune diseases and an impairment in TFR could contribute to
overt autoimmune reactivity in MS disease.
86
Poster Abstracts
P18
MS risk genes are associated with enhanced EBNA-1 humoral
immune response independent of HLA-DR.
Authors
Karim L. Kreft MD PhD1*, Gijsbert P. Van Nierop BASc1,2*, Sandra M.J.
Scherbeijn BASc2, Georges M.G.M. Verjans PhD2,3 and Rogier Q. Hintzen MD
PhD1
Affiliation
Departments of
1
Neurology and MS centre ErasMS
2
Viroscience, Erasmus MC, Rotterdam, the Netherlands
3
Research Center for Emerging Infections and Zoonoses, University of
Veterinary Medicine, Hannover, Germany.
*These authors contributed equally to this study.
Abstract
Background + objective: The complex etiology of multiple sclerosis (MS) involves
both genetic and environmental factors like Epstein Barr virus (EBV) infection. Currently,
more than 150 mainly immune related single nucleotide polymorphisms (SNP) are known
to increase the risk of developing MS. We hypothesized that the immune related MS risk
SNP contribute to the enhanced humoral immune response against EBV observed in MS
patients.
Methods: Serum IgG levels towards EBV nuclear antigen-1 (EBNA-1) were determined
in 566 genotyped MS patients and age/gender-matched 119 healthy individuals. Titers
were dichotomized as above or below the 75th percentile of EBNA-1 IgG levels in MS
patients and healthy EBV carriers. Subsequently, logistic regression was used to determine
which MS risk SNP are associated with an increased risk to have enhanced (>75th percentile) EBNA-1 IgG responses. Analogous analyses were performed on IgG levels directed to
varicella zoster virus (VZV), included as a control herpesvirus not associated with MS.
Results: All included MS patients and healthy individuals were EBV and VZV seropositive. The alternate SNP of previously defined MS-risk alleles of VCAM1, CXCR5
and PRDX5 were independently associated with elevated EBNA-1 IgG, but not VZV IgG
levels. This was only detected in MS patients. Additionally, we confirmed the association
between HLA-DRB1 and enhanced EBNA-1 IgG levels in both cohorts. However, in an interaction model, the combination of MS-risk SNP alleles of VCAM1, CXCR5 and PRDX5,
counteracted the HLA-DRB1 effect on enhanced EBNA-1 IgG response in MS patients.
Analogous associations with VZV IgG responses were not observed.
Conclusions: In addition to HLA-DRB1, we identified three SNPs (VCAM1, CXCR5 and
PRDX5) that are predictive for enhanced EBNA-1 IgG levels, but not VZV IgG levels in MS
patients.
87
Poster Abstracts
P19
Anti-SPAG16 antibodies in multiple sclerosis
Authors
Laura de Bock1, Judith Fraussen1, Luisa M. Villar2, José C. Álvarez-Cermeño2,
Bart Van Wijmeersch1,3, Vincent van Pesch4, Piet Stinissen1 and Veerle Somers1
1
AffiliationHasselt University, Biomedical Research Institute, and Transnationale
Universiteit Limburg, Diepenbeek, Belgium.
2
Departments of Neurology and Immunology, Ramón y Cajal Hospital, Madrid,
Spain.
3
Multiple Sclerosis and Rehabilitation Center, Overpelt, Belgium.
4
Institute of Neurosciences, Neurochemistry Unit, Universite´ Catholique de
Louvain-la-Neuve, Louvain-la-Neuve, Belgium
Abstract
Background + objective: We previously identified Sperm-associated Antigen 16
(SPAG16) as a autoantigenic target in multiple sclerosis (MS) (Somers et. al. 2008.
J. Immunol.). Since SPAG16 was never linked to MS, we further investigated SPAG16
and anti-SPAG16 antibodies in MS pathology. We demonstrated elevated anti-SPAG16
antibodies in the plasma of MS patients with 95% specificity and 21% sensitivity. The
pathologic relevance of these antibodies was shown by the identification of SPAG16-specific oligoclonal bands in the cerebrospinal fluid (CSF) of 5/23 MS patients. In vivo experiments in experimental autoimmune encephalomyelitis (EAE) mice demonstrated that injection with anti-SPAG16 antibodies induced disease exacerbation. Finally, we found that
SPAG16 was specifically upregulated in reactive astrocytes, both in EAE and MS lesions
(de Bock et. al. 2014. J. Immunol.). These results emphasize the involvement of SPAG16
specific autoantibodies in MS, although their exact role remains to be determined. In the
present study, we aim to validate the presence of anti-SPAG16 antibodies in three novel
independent cohorts of MS patients.
Methods: The autoantibody reactivity to SPAG16 was tested in plasma samples using
our recombinant SPAG16 protein ELISA in three different cohorts of MS patients (N=94,
N=196 and N=58) recruited at three locations.
Results: Elevated plasma anti-SPAG16 antibodies were detected in 20% (19/94), 23%
(46/196) and 21% (12/58) of MS patients in the different cohorts.
Furthermore, statistical analysis revealed that there was no overall significant difference
between the three cohorts (P=0.3960). Therefore, future statistical analysis will be performed on the whole MS cohort irrespective of recruitment location and we will compare
the different MS subtypes (relapsing-remitting, primary or secondary progressive). Logistic regression analysis will be performed to identify factors that are predictive of positive
anti-SPAG16 antibody assay results. Pearson chi square test and Fisher’s exact test will
be used for between-group comparisons.
88
Poster Abstracts
Conclusions: Anti-SPAG16 antibody reactivity is present in a subgroup of MS patients
(~22%) in three novel cohorts, which is comparable to our previous studies. Moreover,
assessing demographic and clinical characteristics of MS patients for association with
anti-SPAG16 antibody positivity will provide clues regarding prognostic and/or pathologic
potential of these antibodies in MS.
89
Poster Abstracts
P20
EBV: a new role in MS
Authors Jordon Dunham1,2, Jon D. Laman2 Bert A. ‘t Hart1,2, and Yolanda S. Kap1
1
Affiliation
Department of Immunobiology, Biomedical Primate Research Centre,
Rijswijk, The Netherlands;
2
University Groningen, University Medical Center, Department of
Neuroscience, Groningen, The Netherlands
Background + objective: Epidemiological evidence suggests a role for Epstein-Barr
virus (EBV) in the development of multiple sclerosis (MS). In a non-human primate
model for MS, a γ-herpes virus (CalHV-3) homologous to EBV has also been implicated
in a pathogenic role in disease (EAE) induction. In both MS and marmoset EAE models, CD20+ B-cell depletion reduces disease pathology. CD20+ B-cell depletion in the
common marmoset EAE model profoundly altered the immunostimulatory environment
in the secondary lymphoid organs (SLO), enhanced the percentage of T cells expressing
the homing receptor CCR7, and reduced the γ-herpesvirus virus load. This suggests a role
of the γ-herpesvirus infected B cell in T cell homing. We hypothesized that γ-herpesvirus
infected B cells activate T cells in SLO and license them to egress the SLO.
Methods: EBV-infected B cells were co-cultured with mononuclear cells isolated from
lymph nodes from MOG34-56/IFA immunized marmosets. Expression of surface markers
related to homing (CCR6, CCR7), activation (IL-23R), function (CD27, CD279), and
survival (CD127, CD95) were assessed on T cells by flow cytometry.
Results: Co-culture of γ-herpesvirus infected B cells with lymph node cells reduced the
percentage of CCR7 expressing T cells. This reduction was independent of stimulation
with MOG34-56. Interestingly, CCR7 down-regulation was especially observed in animals
that were sacrificed with clinical symptoms of EAE, while in animals that did not develop
clinical symptoms CCR7 expression was unchanged. MOG34-56-independent reductions
of CD27 expression were observed, and this reduction correlated to a loss of expression
of Th17 markers (IL-23R, CCR6). Whereas apoptosis antigen 1 (CD95) expression up
regulation was not restricted to MOG34-56 stimulation, significant reductions of IL7R (CD127) were observed and in a peptide-restricted fashion. Detection of enhanced
expression of programmed cell death (PD-1;CD279) and trogocytotic acquisition of CD86
were observed, suggesting mechanisms of immune escape.
Conclusions: Collectively these data suggest that the EBV B cell phenotypically alters
the T cell in critical markers related to homing, development, function and survival in
ways that may lead to altered migration and exhaustion. These immune-modulatory effects, in context to infectious mononucleosis and chronic EBV exposure, may explain the
temporal association between EBV and autoimmune diseases such as MS.
90
Poster Abstracts
P21
The importance of costimulation and antigen presentation by B
cells in multiple sclerosis
Authors
Fraussen J1, Claes N1, Van Wijmeersch B1, Hupperts R2, Stinissen P1,
Somers V1
1
Affiliation
Hasselt University, Biomedical Research Institute, and Transnationale
Universiteit Limburg, School of Life Sciences, Diepenbeek, Belgium
2
Department of Neurology, Orbis Medical Center, Sittard, The Netherlands
Abstract
Background + objective: The success of B cell depletion therapy in multiple sclerosis (MS) has pointed towards the involvement of antibody-independent B cell functions.
The aim of this study is to analyze antigen presentation and costimulation by B cells in
MS.
Methods: Expression of costimulatory and antigen presentation molecules was measured on B cells from the peripheral blood and cerebrospinal fluid (CSF) of MS patients
(n = 74 and n = 20, respectively) and peripheral blood of healthy individuals (HC, n =
52) using flow cytometry. B cell proliferation and antigen presentation capacity following
antigen-specific stimulation was studied in vitro. B cells of 5 MS patients and 5 HC were
labeled with CFSE and cultured 1:1 with autologous feeder cells during 13 days in the
presence of tetanus toxoid (TT), myelin antigens or cytomegalovirus (CMV).
Results: MS patients showed an increased CD80 and CD40 B cell expression and an
increased percentage CD80 + and CD86+ B cells when compared to HC. In the CSF,
percentages and fluorescence intensity of CD86+ and CD80+ B cells were even further
elevated. B cell proliferation against myelin antigens and CMV was demonstrated in some
MS patients. Following stimulation with myelin and viral antigens, the percentage of
CD80+ and HLA-DR+ B cells was increased, emphasizing the potential of these B cells to
activate autoreactive T cells.
Conclusions: These results indicate the potential of B cells to function in antigen
presentation and costimulation in MS. In vitro culture systems are currently optimized to
study the interaction between T cells and B cells in MS.
91
Poster Abstracts
P22
Sleep problems and cognition in Multiple Sclerosis.
Authors
Benthe Westerik, Quinten van Geest, Jeroen J. G. Geurts & Hanneke E. Hulst
Affiliation Department of Anatomy and Neurosciences, VUmc, Amsterdam
Abstract
Background + objective: Approximately 70% of patients with multiple sclerosis
(MS) experience cognitive problems. Additionally, in more than 50% of the patients sleep
problems occur. Previous studies in healthy controls (HCs) suggest that sleep is essential
for proper cognitive functioning. As there are still no effective treatment options for cognitive impairment in MS, treating sleep problems might have a beneficial, indirect effect
on cognitive functioning. As a first step, the aim of the present study was to explore the
relationship between sleep problems and cognition in patients with MS.
Methods: Sleep problems were investigated using the five-item version of the Athens
Insomnia Scale (AIS-5). The AIS-5 includes items of sleep induction, awakenings during
the night, final awakening earlier than desired, total sleep duration, and overall sleep
quality. Cognitive functioning was assessed using an extensive neuropsychological test
battery, including tests on verbal learning and memory, spatial memory, working memory,
information processing speed and verbal fluency. Additionally, questionnaires on fatigue
(CIS-20), anxiety and depression (HADS) and subjective cognitive functioning were
administered.
Results: Seventy-one MS patients (mean age: 45.7±8.3, 47 females) and 40 HCs
(mean age: 44.0±9.1, 26 females) were investigated. MS patients scored significantly
worse than the HCs on all cognitive tests. Based on a median split of the AIS-5 scores in
both the MS and HC group separately, 25 MS patients and 16 HCs were categorized as
experiencing sleep problems. No significant differences in cognitive functioning were observed between MS patients with and without sleep problems, and between HCs with and
without sleep problems. In HCs, but not in MS patients, AIS-5 scores correlated positively
with fatigue.
Conclusions: The findings of this study suggest that either the AIS-5 is not sensitive
enough to detect true sleeping disturbances in patients with MS or that there is not a direct relation between sleeping disturbances and cognitive deficits. Future studies should
aim to investigate sleep and sleeping problems in MS in more depth.
92
Poster Abstracts
P23
eMotionS: emotional memory impairment and amygdala
activation in multiple sclerosis
Authors:
Q. van Geest1, H.E. Hulst1, B.M.J. Uitdehaag2, F. Barkhof3, J.J.G. Geurts1
1
Affiliation
Department of Anatomy and Neurosciences, VU University Medical Center,
Amsterdam
2
Department of Neurology, VU University Medical Center, Amsterdam
3
Department of Radiology and Nuclear Medicine, VU University Medical
Center, Amsterdam
Abstract
Background + objective: In multiple sclerosis (MS), emotional memory is relatively
understudied. However, the amygdala of MS patients can show various abnormalities,
including demyelination, atrophy, iron deposition and functional alterations during processing of emotional faces. The aim of this study was to explore the relationship between
emotional memory and amygdala activation in patients with MS.
Methods: Neuropsychological testing, psychiatric interview, and (f)MRI (1.5T) were
performed in 39 MS patients (24 female; mean age 48.04±8.33 years) and 25 healthy
controls (HCs; 16 female; mean age 46.76±8.74 years). The fMRI paradigm consisted of
neutral to highly negative emotional pictures which subjects had to rank in an emotional
category (neutral (1) to highly emotional (4)). Two weeks after scanning, a recognition
task was performed. Based on recognition of highly emotional pictures, patients were
categorized as emotional memory impaired (EMI; n=12) when they performed 1.5 SD
below the mean score of HCs. Otherwise, patients were categorized as emotional memory
preserved (EMP; n=27).
Results: None of the subjects met the criteria for a mental disorder. Compared to
HCs, EMP and EMI patients scored significantly lower on verbal learning and memory and information processing speed. Left amygdala volume was significantly lower in
EMP patients compared to HCs, whereas the right amygdala was significantly smaller in
both EMP and EMI patients compared to HCs. During processing of emotional pictures,
decreased activation of the right amygdala, right parahippocampal areas and hypothalamus was observed in EMI patients versus HCs (unclustered, z≥3.1, p≤.001). Decreased
hypothalamic activation was also observed in EMI patients compared to EMP patients
(unclustered, z≥3.1, p≤.001). A regions of interest analysis confirmed decreased activation in de amygdala in EMI patients versus HCs.
Conclusions: The present results indicate that reduced activation in the amygdala
(important for emotion regulation), parahippocampal areas (essential for memory) and the
hypothalamus can be related to impaired emotional memory in patients with MS.
93
94
Leidseweg 557-1
2253 JJ Voorschoten
Postbus 200
2250 AE Voorschoten
T 071 - 5 600 500
www.msresearch.nl