Enter the matrix: Shape, signal and superhighway

Abstract

Mammalian skeletal muscle is notable for both its highly ordered biophysical structure and its regenerative capacity following trauma. Critical to both of these features is the specialized muscle extracellular matrix, comprising both the multiple concentric sheaths of connective tissue surrounding structural units from single myofibers to whole muscles and the dense interstitial matrix that occupies the space between them. Extracellular matrix-dependent interactions affect all activities of the resident muscle stem cell population (the satellite cells), from maintenance of quiescence and stem cell potential to the regulation of proliferation and differentiation. This review focuses on the role of the extracellular matrix in muscle regeneration, with a particular emphasis on regulation of satellite-cell activity. The extracellular matrix of skeletal muscle is a highly ordered and regulated series of structures that participate in biophysical and biochemical interactions with local cell types, including muscle stem cells (satellite cells). We provide an overview of these interactions in the context of muscle homeostasis and repair, highlight significant unanswered question, and suggest areas of future interest. © 2013 The Authors Journal compilation © 2013 FEBS.