Cellular and molecular bases of muscle regeneration: The critical role of insulin-like growth factor-1

One of the most exciting aspirations of current medical science is the regeneration of damaged body parts. The capacity of adult tissues to regenerate in response to injury stimuli represents an important homeostatic process that until recently was thought to be limited in mammals to tissues with high turnover such as blood and skin. However, this central dogma of cell biology has been revised on the basis of recent experimental evidence that even the adult brain is able to undergo repair. It is now generally accepted that each tissue type, even those such as nerves or muscle that are considered postmitotic, contains a reserve of undifferentiated progenitor cells, loosely termed stem cells, that participate in tissue regeneration and repair. Regeneration represents a coordinate process in which these stem cell populations are activated to maintain and preserve tissue structure and function upon injured stimuli. In this review we will discuss the molecular and cellular basis of muscle regeneration, the critical role of IGF-1 on muscle homeostasis, and its potential therapeutic approach to improve muscle regeneration and to attenuate atrophy and frailty associated with muscle diseases.