A protein increased by endurance exercise has been isolated and given to non-exercising mice, turning on genes that promote brain health and encourage the growth of new nerves involved in learning and memory, scientists from Harvard Medical School and Dana-Farber Cancer Institute have reported.
The findings, published in the journal Cell Metabolism, help explain the well-known capacity of endurance exercise to improve cognitive function, particuarly in older people. If the protein can be made in a stable form and developed into a drug, it might lead to improved therapies for cognitive decline in older people and slow the toll of neurodegenerative diseases such as Alzheimer's and Parkinsons's, according to the investigators.
"What is exciting is that a natural substance can be given in the bloodstream that can mimic some of the effects of endurance exercise on the brain," said Bruce Spiegelman, the HMS Stanley J. Korsmeyer Professor of Cell Biology and Medicine at Dana-Farber. He is co-senior author of the publication with Michael Greenberg, the Nathan Marsh Pusey Professor of Neurobiology and head of the Department of Neurobiology at HMS.
The Spiegelman group previously reported that the protein, called FNDC5, is produced by muscular exertion and is released into the bloodstream as a variant called irisin. In the new research, endurance exercise - mice voluntarily running on a wheel for 30 days - increased the activity of a metabolic regulatory molecule, PGC-1 alpha, in muscles, which spurred a rise in FNDC5 protein.