New study shows how exercise hormone reduces multiple sclerosis symptoms

A new study offers clues as to why exercise can improve neurological symptoms in people with multiple sclerosis (MS). The study, led by investigators from Mass General Brigham and University Medical Center Hamburg-Eppendorf (UKE), examined levels of the exercise hormone irisin in a mouse model of multiple sclerosis. Researchers found that irisin reduced both clinical symptoms and the loss of neurons in the experimental model. Additionally, when irisin was removed, the protective effects of exercise disappeared. Taken together, the researchers' findings suggest that irisin can protect neurons from inflammation-driven neurodegeneration, offering a potential target for future MS therapies. Results are published in Nature Metabolism.

We are optimistic that our study will open up further developments of irisin as a therapeutic for, in particular, progressive MS. Our findings strengthen the argument that irisin can help protect neurons in the context of multiple types of neurodegenerative diseases."

Christiane D. Wrann, DVM, PhD, corresponding author, neuroscientist and leader of the Program in Neuroprotection in Exercise at Mass General Brigham Neuroscience Institute and the McCance Center for Brain Health at Massachusetts General Hospital

MS is a chronic, autoimmune-mediated neurodegenerative disease in which the immune system attacks the myelin sheaths that swath neurons in the brain and spinal cord. Current therapies for MS reduce inflammation but do not adequately prevent neurodegeneration. Research from other groups has shown that aerobic exercise can improve MS symptoms, but the exact mechanisms have been unknown.