Dividing to keep muscle together: the role of satellite cells in aging skeletal muscle.

The factors responsible for the atrophy of skeletal muscle with aging remain to be elucidated. Recent evidence points toward an important role for a population of cells located on the surface of skeletal muscle fibers, known as satellite cells, in maintaining the integrity of skeletal myocytes throughout the life span. This Perspective examines the role that these cells are thought to play in aging muscle atrophy, and highlights a recent study by Brack and colleagues that attempts to understand the role of satellite cells in maintaining the ratio of myonuclear number to cytoplasmic volume within myocytes as we age.