Myogenic progenitor cells express filamin C in developing and regenerating skeletal muscle.

The regenerative capacity of skeletal muscle is due to the myogenic progenitor cell population that is resident in adult skeletal muscle. To enhance our understanding of this cell population, we examined the temporal-spatial expression pattern for filamin C during murine embryogenesis, adult muscle regeneration and in selected myopathic models of human disease. Using in situ hybridization, we observed filamin C to be restricted to mesodermal lineages including the developing heart and skeletal muscle during embryogenesis. Following cardiotoxin-induced muscle injury of adult skeletal muscle, filamin C expression was dynamically regulated in activated myogenic progenitor cells and newly regenerated myotubes. This expression pattern was further supported using RT-PCR analysis of filamin C expression in differentiating C2C12 myotubes. These results support the paradigm that the regulatory mechanisms of muscle regeneration largely recapitulate the fundamental events observed during muscle development and that filamin C may function in signal transduction or cellular migration of the myogenic progenitor cell population.