Cellular and molecular regulation of muscle regeneration.

Under normal circumstances, mammalian adult skeletal muscle is a stable tissue with very little turnover of nuclei. However, upon injury, skeletal muscle has the remarkable ability to initiate a rapid and extensive repair process preventing the loss of muscle mass. Skeletal muscle repair is a highly synchronized process involving the activation of various cellular responses.

Aging-related satellite cell differentiation defect occurs prematurely after Ski-induced muscle hypertrophy.

To investigate the cause of skeletal muscle weakening during aging we examined the sequence of cellular changes in murine muscles. Satellite cells isolated from single muscle fibers terminally differentiate progressively less well with increasing age of donor. This change is detected before decline in satellite cell numbers and all histological changes examined here.