beta 4 Integrin Marks Interstitial Myogenic Progenitor Cells in Adult Murine Skeletal Muscle

Skeletal muscle growth and its regeneration following injury rely on myogenic progenitor cells, a heterogeneous population that includes the satellite cells and other interstitial progenitors. The present study demonstrates that surface expression of beta 4 integrin marks a population of vessel-associated interstitial muscle progenitor cells. Muscle beta 4 integrin-positive cells do not express myogenic markers upon isolation. However, they are capable of undergoing myogenic specification in vitro and in vivo: beta 4 integrin cells differentiate into multinucleated myotubes in culture dishes and contribute to muscle regeneration upon delivery into diseased mice. Subfractionation of beta 4 integrin-expressing cells based on CD31 expression does not further enrich for myogenic precursors. These findings support the expression of beta 4 integrin in interstitial, vessel-associated cells with myogenic activity within adult skeletal muscle. (J Histochem Cytochem 60:31-44, 2012