Role of Cd34 Expression and Cellular Fusion in the Regeneration Capacity of Myogenicprogenitor Cells

INTRODUCTION: Characterization of myogenic progenitor cells has traditionally been performed using the well-defined myogenic regulatory factor family (MRF) of transcription factors. Observed differential expression patterns of these MRF proteins have led to proposed organizational models of hierarchy among myogenic progenitor cells. However, recent interest in the isolation of myogenic populations with potential stem cell-like abilities has led to enhanced interest in the characterization of myogenic cells in terms of surface protein expression: primarily, CD34 and stem cell antigen-1 (Sca-1). Researchers are now performing these types of characterizations on donor populations prior to transplantation, while focusing on defining populations with enhanced regeneration abilities. Of particular interest are the cells’ dystrophin restoring abilities for use in clinical cellular therapies for muscular dystrophies. We investigated the use of these cell surface proteins to potentially identify progenitors with enhanced regeneration capabilities. Regeneration efficiency of sorted progenitors, along with corresponding in vitro cellular characteristics, was compared by quantifying their ability to regenerate skeletal muscle and restore dystrophin following transplantation into allogenic dystrophic host muscle.