Researchers aiming to produce a mouse model of accelerated sarcopenia, the characteristic loss of muscle mass and strength that occurs with aging, instead found that depleting muscle stem cell populations had no effect on this condition. This implies that the loss of stem cell activity in muscle tissue associated with aging may not be all that important in the development of sarcopenia after all:
Sarcopenia affects millions of aging adults. Age-related loss of muscle mass and strength not only robs elderly people of the ability to perform even the most basic tasks of daily living, but also significantly increases their risk of suffering devastating injuries and even death from sudden falls and other accidents. The literature on aging research, particularly muscle aging, postulates a strong correlation between the loss and/or dysfunction of muscle stem cells and sarcopenia, the scientific term for the age-related loss of skeletal muscle mass and strength. Currently entire research programs are focused on developing muscle stem cell therapy to delay, prevent or even reverse sarcopenia.
[Researchers] developed an animal model that allowed them to deplete young adult muscle of stem cells to a level sufficient to impair muscle regeneration throughout the life of a mouse. They expected the mouse to be a model of premature muscle aging. "To our surprise, the mice aged normally; life-long depletion of skeletal muscle stem cells did not accelerate nor exacerbate sarcopenia. Our negative results show a clear distinction between therapeutic strategies that may effectively treat degenerative myopathies, such as dystrophies and cachexia, versus sarcopenia. While degenerative conditions are expected to benefit from a stem cell-based therapy, this does not appear to be a viable approach for treating age-associated muscle wasting. Hopefully, our work will help to refocus aging muscle research on new therapeutic targets to effectively maintain muscle function and prevent frailty in the elderly."