Marker Expression of Interstitial Cells in Human Skeletal Muscle: An Immunohistochemical Study

There is a growing recognition that myogenic stem cells are influenced by their microenvironment during regeneration. Several interstitial cell types have been described as supportive for myoblasts. In this role, both the pericyte as a possible progenitor for mesenchymal stem cells, and interstitial cells in the endomysium have been discussed. We have applied immunohistochemistry on normal and pathological human skeletal muscle using markers for pericytes, or progenitor cells and found a cell type co-expressing CD10, CD34, CD271, and platelet-derived growth factor receptor α omnipresent in the endomysium. The marker profile of these cells changed dynamically in response to muscle damage and atrophy, and they proliferated in response to damage. The cytology and expression profile of the CD10+ cells indicated a capacity to participate in myogenesis. Both morphology and indicated function of these cells matched properties of several previously described interstitial cell types. Our study suggests a limited number of cell types that could embrace many of these described cell types. Our study indicate that the CD10+, CD34+, CD271+, and platelet-derived growth factor receptor α+ cells could have a supportive role in human muscle regeneration, and thus the mechanisms by which they exert their influence could be implemented in stem cell therapy.