Direct isolation, culture and transplant of mouse skeletal muscle derived endothelial cells with angiogenic potential

Background: Although diseases associated with microvascular endothelial dysfunction are among the most prevalent illnesses to date, currently no methods exists to isolate pure endothelial cells (FC) from skeletal musle for in vivo or in vitro study. Methodology: By utilizing multicolor fluorescent-activated cell sorting (FACS), we have isolated a distinct population of Sca-1⁺, CD31⁺, CD34^dim CD45^- cells from skeletal muscle of C57BL6 mice. Characterization of this population revealed these cells are functional EC that can be expanded several times in culture without losing their phenotype or capabilities to uptake acetylated low-density lipoprotein (ac-LDL), produce nitic oxide (NO) and form vascular tubes. When transplanted subcutaneously or intramuscularly into the tibialis anterior muscle, EC formed microvessels and integrated with existing vasculature. Conclusion: This method, which is highly reproducible, can be used to study the biology and role of EC in diseases such as peripheral vascular disease. In addition this method allows us to isolate large quantities of skeletal muscle derived EC with potential for therapeutic angiogenic applications.