Effects Of Two Longevity Interventions, Calorie Restriction And Rapamycin Treatment, On The Kynurenine-Aryl Hydrocarbon Receptor Pathway In Aging Skeletal Muscle
Maintaining strong and healthy muscles is incredibly important as we get older for a good quality of life. Scientists have long known that reducing calorie intake without malnutrition, a process called calorie restriction, can significantly extend both health and lifespan. However, sticking to such a strict diet is very challenging for most people.
This has led researchers to look for “calorie restriction mimetics”—substances that can mimic these benefits without the need for drastic dietary changes. One promising candidate is rapamycin, a drug that inhibits a key cellular pathway called mTORC1, which is involved in cell growth and metabolism. Rapamycin has been shown to help prevent age-related muscle loss.
This study explored how calorie restriction and rapamycin affect a specific biological pathway in aging muscles, known as the kynurenine-aryl hydrocarbon receptor (AhR) pathway. This pathway is particularly interesting because a molecule called kynurenine, which increases with age, can activate the AhR and contribute to muscle wasting.
Surprisingly, the research found that while both calorie restriction and rapamycin improved aging muscles, they did so through different genetic mechanisms. Calorie restriction, for example, reduced the activity of the AhR in some muscles and boosted the production of enzymes that convert harmful kynurenine into a less active form. In contrast, rapamycin did not significantly change AhR activity and even decreased some of these beneficial enzymes.
These findings suggest that calorie restriction and rapamycin work through unique biological routes to combat muscle aging. This opens up exciting possibilities for future anti-aging strategies, where combining these two interventions might offer even greater benefits than either one alone.
Source: link to paper