News Release 

Slowing the progression of multiple sclerosis

CRCHUM researchers pave the way for new therapies

University of Montreal Hospital Research Centre (CRCHUM)

Montreal, November 13, 2019 -- Over 77,000 Canadians are living with multiple sclerosis, a disease whose causes still remain unknown. Presently, they have no hope for a cure. In a study published in Science Translational Medicine, researchers at the University of Montreal Hospital Research Centre (CRCHUM) identify a molecule named ALCAM which, once blocked, delays the progression of the disease. Their results, obtained from in vitro human and in vivo mouse studies, could lead to the development of a new generation of therapies to treat this autoimmune disease.

Under normal conditions, the blood-brain barrier protects our brain from exposure to harmful elements. For example, it prevents cells of the immune system such as lymphocytes from invading our central nervous system. However, in people with multiple sclerosis, this barrier is permeable. A large number of lymphocytes manage to migrate into the brain and deteriorate its tissues (by destruction of the myelin sheath that protects the neurons and enables the transmission of nerve impulses).

"In our study, we show for the first time that a molecule called ALCAM (Activated Leukocyte Cell Adhesion Molecule), expressed by B cells, controls their entry into the brain via blood vessels. It allows them to migrate to the other side of the blood-brain barrier in mice and humans. By blocking this molecule in mice, we were able to reduce the flow of B cells into their brains and, as a result, slow the progression of the disease," said Dr. Alexandre Prat, a researcher at the CRCHUM, professor at the Université de Montréal and holder of the Canada Research Chair in Multiple Sclerosis.

B cells contribute to the progressive phase of multiple sclerosis. Certain medications, commonly known as anti-B-cell drugs, reduce its progression and the resulting disability.

"The molecule ALCAM is expressed at higher levels on the B cells of people with multiple sclerosis. By specifically targeting this molecule, we will now be able to explore other therapeutic avenues for the treatment of this disease," said Dr. Prat.

Multiple sclerosis can cause symptoms such as fatigue, lack of coordination, vision problems, cognitive impairment and mood changes. One in every 385 Canadians have the disease, including 20,000 people in Quebec. Sixty per cent of adults with multiple sclerosis are between the ages of 20 and 49 and women are three times more likely than men to be diagnosed with it.

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This research was funded by the Multiple Sclerosis Society of Canada, the Canadian Institutes of Health Research, and the Fonds de Recherche du Québec--Santé.

Further reading: "Activated Leukocyte Cell Adhesion Molecule Regulates B Lymphocyte Migration Across Central Nervous System Barriers" by Laure Michel, Camille Grasmuck et al. in Science Translational Medicine. DOI : 10.1126/scitranslmed.aaw0475

About the CRCHUM

The University of Montreal Hospital Research Centre (CRCHUM) is one of North America's leading hospital research centres. It strives to improve adult health through a research continuum covering such disciplines as the fundamental sciences, clinical research and public health. Over 1,861 people work at the CRCHUM, including 542 scientists and 719 students and research assistants. chumontreal.qc.ca/crchum @CRCHUM

About Université de Montréal

Deeply rooted in Montreal and dedicated to its international mission, Université de Montréal is one of the top universities in the French-speaking world. Founded in 1878, Université de Montréal today has 13 faculties and schools, and together with its two affiliated schools, HEC Montréal and Polytechnique Montréal, constitutes the largest centre of higher education and research in Québec and one of the major centres in North America. It brings together 2,400 professors and researchers and has more than 67,000 students. umontreal.ca

Media contact - information and interviews

Bruno Geoffroy
Science Writer
University of Montreal Hospital Research Centre (CRCHUM)
514-890-8000 ext. 30872
bruno.geoffroy.chum@ssss.gouv.qc.ca

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