Upregulation of MOTS-c improves mitochondrial function and has other less well explored influences on stress responses in cells. This might be considered a form of exercise mimetic therapy, given that MOTS-c upregulation is one of the outcomes of exercise. The result of artificial upregulation of MOTS-c in mice is improved health, greater exercise capacity, and extended life span. We should probably not expect life span effects produced by this sort of intervention to translate well to longer-lived mammals, given what we know of the effects of calorie restriction, exercise, and similar interventions that upregulate stress response mechanisms. Benefits to health are certainly plausible, however.
The study looked at the role of MOTS-c, one of several recently identified hormones known to mimic the effects of exercise. However, MOTS-c is unique because it is encoded in the small genome of mitochondria rather than the larger genome in a cell's nucleus. The research team tested how injections of MOTS-c affected mice of different ages by measuring physical capacity and performance in young (2 months), middle-aged (12 months), and old (22 months) mice. When the mice were presented with physical challenges - including maintaining balance on a rotating rod and running on an accelerating treadmill - mice of all ages who had received MOTS-c treatment fared significantly better than untreated mice of the same age.
Even groups of mice that had been fed a high-fat diet showed marked physical improvement after MOTS-c treatment and less weight gain than untreated mice. These findings echo previous research on MOTS-c treatment in mice, which also found that it reversed diet-induced obesity and diet- and age-dependent insulin resistance. Additionally, treating the oldest mice nearing the end of their lives with MOTS-c resulted in marked physical improvements. This late-life treatment improved grip strength, gait (measured by stride length) and physical performance, which was assessed with a walking test (running was not possible at this age)."The older mice were the human equivalent of 65 and above and once treated, they doubled their running capacity on the treadmill. They were even able to outrun their middle-aged, untreated cohorts."
To measure the effects of exercise on MOTS-c levels in people, the researchers collected skeletal muscle tissue and plasma from sedentary, healthy young male volunteers who exercised on a stationary bicycle. Samples were collected before, during and after the exercise as well as following a 4-hour rest. In muscle cells, levels of MOTS-c significantly increased nearly 12-fold after exercise and remained partially elevated after a four-hour rest, while MOTS-c levels in blood plasma also increased by approximately 50% during and after exercise and then returned to baseline after the rest period. The findings suggest that the exercise itself induced the expression of the mitochondrial-encoded regulatory peptides.