Exercise reduces the symptoms of multiple sclerosis, according to one study.

Current therapies for MS reduce inflammation

The study, led by researchers 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 cord neurons from inflammation-driven neurodegeneration, offering a potential target for future MS therapies. Results are published in Nature Metabolism.

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. Wrann and colleagues have previously shown that the hormone irisin, produced by muscles during exercise, can improve cognitive function and neuroinflammation in mouse models of Alzheimer's disease. In their new federally funded study of MS, researchers also found evidence of neuroprotective effects. In the MS model, deleting irisin canceled the protective effects of exercise while adding irisin back rescued neurons and improved disease outcomes.

Rosenkranz, MD, first author and head of the Behavioral Interventions group at the Institute for Neuroimmunology and Multiple Sclerosis (INIMS) at UKE. Rosenkranz is a former postdoctoral fellow at the Wrann lab. „Interestingly, in the current study we did not find a direct suppressive effect of irisin on peripheral immunity, but rather direct neuroprotective effects”, said Ruxandra F. Sîrbulescu, PhD, co-senior author on the study, a neuroimmunologist at the Mass General Brigham Neuroscience Institute and leader of the Regenerative Medicine program at the Vaccine and ImotherCenter.