Multiple sclerosis (MS) may be triggered by the death of brain cells that make myelin, the insulation around nerve fibers, according to research on a novel mouse model developed by scientists from the University of Chicago and Northwestern Medicine. The death of these cells initiates an autoimmune response against myelin, the main characteristic of the disease, which leads to MS-like symptoms in mice
This reaction can be prevented, however, through the application of specially developed nanoparticles, even after the loss of those brain cells. The nanoparticles are being developed for clinical trials that could lead to new treatments in humans.“Although this was a study in mice, we’ve shown for the first time one possible mechanism that can trigger MS — the death of the cells responsible for generating myelin can lead to the activation of an autoimmune response against myelin,” said study co-senior author Brian Popko, PhD, Jack Miller Professor of Neurological Disorders at the University of Chicago. “Protecting these cells in susceptible individuals might help delay or prevent MS.”
Multiple sclerosis is a neurological disease involving an abnormal immune response against myelin, which leads to the progressive deterioration of a wide range of body functions. MS is thought to affect 2.5 million people worldwide, and has unclear causes and no known cure.To study how MS is triggered, Popko, with collaborator Stephen Miller, PhD, Judy Gugenheim Research Professor of Microbiology-Immunology at Northwestern University Feinberg School of Medicine, and their teams developed a genetically engineered mouse model that allowed them to target oligodendrocytes, the brain cells that produce myelin.
By specifically killing oligodendrocytes, the team observed MS-like symptoms that affected the ability of the mice to walk. After this initial event, the central nervous systems of the mice regenerated their myelin-producing cells, enabling them to walk again. But about six months later, the MS-like symptoms came barreling back.“To our knowledge, this is the first evidence that oligodendrocyte death can trigger myelin autoimmunity, initiating inflammation and tissue damage in the central nervous system during MS,” said study co-author Maria Traka, PhD, research associate professor in neurology at the University of Chicago.possible causes of oligodendrocyte death are developmental abnormalities, viruses, bacterial toxins or environmental pollutants. In humans, the researchers hypothesize MS could develop years after an initial injury to the brain triggers oligodendrocyte death.