Skeletal Muscle Regeneration: MSC versus Satellite Cells

Abstract

Problem Differentiating stem cells into the myogenic linage in order to create functional muscle tissue is a challenging endeavour. In this work, adipose-derived mesenchymal stem cells (MSC) and satellite cells derived from muscle biopsies were compared regarding proliferation and myogenic differentiation potential under standardized cell culture conditions. This data was obtained in order to discover the most promising type of stem cell for regeneration of muscle tissue and to determine the optimal culture conditions for later clinical use. Methods Human MSC were isolated from adipose tissue, and primary human skeletal myoblasts were extracted from muscle biopsies by enzymatic digestion. Proliferation was analysed using the AlamarBlue® assay. Gene expression of marker genes – such as Myogenin, Myo D, Myf 5 and MHC – were analysed by RT-PCR. Immunostainings against desmin and sarcomeric-actin were performed as differentiation markers. Results MSC cell cultures showed a greater proliferation rate compared with satellite cell cultures. In both stem cell cultures, myogenic differentiation/heritage could be verified by immunostainings against the muscle-specific marker desmin. Gene expression and protein analysis revealed a more stable differentiation of human satellite cell cultures. Conclusion Characterization of both human MSC cultures and satellite cell cultures – and thereby an understanding of myogenesis – might lead to their clinical usage in skeletal muscle tissue engineering. The results in this study appear to indicate that human satellite cell cultures have a more stable differentiation under in vitro conditions and that they might offer a greater potential for skeletal muscle tissue engineering purposes. Significance Our study contributes to the understanding of myogenic differentiation of MSC and satellite cells and helps to improve culture systems for later clinical utilization.