A new study provides clues as to why exercise can improve neurological symptoms in multiple sclerosis (MS) patients. The study, led by researchers at Massachusetts General Brigham and the 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 neuronal loss in experimental models. Furthermore, removal of irisin abolished the protective effect of exercise. Taken together, the researchers’ findings suggest that irisin can protect neurons from inflammation-induced neurodegeneration, making it a potential target for future MS treatments. Results are posted below natural metabolism.
We are optimistic that this study will open up further development of irisin, particularly as a treatment for progressive MS. Our findings strengthen the argument that irisin may help protect neurons in multiple types of neurodegenerative diseases. ”
Christian D. Lunn, DVM, Ph.D. Corresponding author, Neuroscientist and leader of the Exercise Neuroprotection Program at the Massachusetts 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 sheath that covers neurons in the brain and spinal cord. Current MS treatments reduce inflammation but do not adequately prevent neurodegeneration. Studies from other groups have shown that aerobic exercise can improve MS symptoms, but the exact mechanism is unclear.
Wrann et al. previously showed that the hormone irisin, produced by muscles during exercise, can improve cognitive function and neuroinflammation in a mouse model of Alzheimer’s disease. In a new federally funded study of MS, researchers also found evidence of neuroprotective effects. In MS models, removing irisin abrogated the protective effects of exercise, while adding irisin rescued neurons and improved disease outcome. Irisin attenuated neuronal loss in three central nervous system compartments: spinal cord, hippocampus, and retina, attenuated synaptic loss, and restored neuroprotective gene programs.
“Of particular interest is that exercise-induced molecules can directly protect neurons in a mouse model of multiple sclerosis, revealing a fundamentally new mechanism by which exercise influences neurodegeneration in MS,” said first author Sheena C. Rosenkranz, MD, PhD, head of the Behavioral Interventions Group at the UKE Institute of Neuroimmunology and Multiple Sclerosis (INIMS). Rosenkranz is a former postdoctoral fellow in the Lan lab.
“Interestingly, in this study we did not find a direct suppressive effect of irisin on peripheral immunity, but rather a direct neuroprotective effect,” said study co-senior author Ruxandra F. Silbulescu, Ph.D., a neuroimmunologist at the Massachusetts General Brigham Neuroscience Institute and leader of the Regenerative Medicine Program at the Center for Vaccines and Immunotherapy.
The authors note that further research is needed to understand how irisin’s protective mechanisms work. They also point out that it’s important to remember that the benefits of exercise in multiple sclerosis are complex and likely involve multiple factors, not just irisin alone. The research team plans to continue investigating the effects and mechanisms of this hormone in future studies.
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Reference magazines:
rosary, south carolina Others. (2026) The exercise hormone irisin has neuroprotective effects in a mouse model of multiple sclerosis. natural metabolism. DOI: 10.1038/s42255-026-01527-7. https://www.nature.com/articles/s42255-026-01527-7
