Workout Boost: How Exercise Affects Muscle Pathways in Older Mice and Humans

The Notch pathway is key to our muscles' growth, repair, and aging. Scientists studied how interleukin-10 (IL-10), a crucial immune system protein, affects this pathway in muscle cells. They also looked at how a mix of endurance and strength exercises changes muscle quality in older mice. In this study, researchers first tampered with IL-10 in muscle cells called C2C12 myoblasts. They found that doing so lowered the activity of Notch genes and proteins. Next, they exercised two groups of mice—some were prone to aging quickly (SAMP8) and others were more resistant (SAMR1). They analyzed muscle samples from the thighs and calves. The results? Exercise improved muscle fiber organization and balance in the SAMP8 mice. It also boosted the levels of certain genes (Notch2 and Hes1) involved in muscle growth and repair. Interestingly, even in older humans, physical activity seemed to raise these gene levels compared to younger folks with similar activity levels. This suggests that a mix of exercises can help muscles regenerate better in older folks, all thanks to the Notch pathway.