Not an Inside Job: How Can Transplantation of Relatively Few Exogenous Satellite Cells Do What Thousands of Endogenous Cells Cannot?

Abstract

When muscle fibers are damaged, they release growth factors that stimulate the proliferation of muscle stem cells termed satellite cells (Figure 1). The progeny of these newly proliferating satellite cells then fuse with the damaged muscle fibers so as to repair them. This process is generally able to maintain muscle strength and size but can tend to fail during the aging process and in certain disease states, such as in dystrophic muscle. This has spurred efforts to develop molecular and cellular therapies to stimulate the repair process.