Last year we learned that simply diluting old blood in the aged lets them function like younger (animals and humans) (Reference). Still, the search is continuing for youth factors in young blood that might also allow reversing some of aging. A new study has shown that well exercised mice have extra-cellular vesicles (EVs) secreted by muscle cells, in their plasma that contain micro-RNAs coding for Klotho – a known longevity factor – whereas sedentary/non-exercising mice did not. The mRNAs  increase the expression of Klotho in muscle stem cells. The team demonstrated that replacing plasma in old mice with plasma from young, exercised mice restored muscle quality – From the Eurekalert Article:

“Delving deeper, the researchers found that EVs deliver genetic instructions, or mRNA, encoding the anti-aging protein Klotho to muscle progenitor cells, a type of stem cell that is important for regeneration of skeletal muscle. EVs collected from old mice carried fewer copies of the instructions for Klotho than those from young mice, prompting muscle progenitor cells to produce less of this protein.

With increasing age, muscle doesn’t heal as well after damage because scar tissue is deposited instead of restoring original muscle structure. In earlier work, Ambrosio and her team showed that Klotho is an important regulator of regenerative capacity in muscle progenitor cells and that this protein declines with age.”

Klotho is being investigated as a drug that could reverse many factors of aging; here is another possible approach: Harvest the EVs from young athletes and top up the Klotho expression in we who are aging periodically,