Isolation and characterization of vessel-associated stem/progenitor cells from skeletal muscle

More than 10 years ago, we isolated from mouse embryonic dorsal aorta a population of vessel-associated stem/progenitor cells, originally named mesoangioblasts (MABs ), capable to differentiate in all mesodermal-derived tissues, including skeletal muscle. Similar though not identical cells have been later isolated and characterized from small vessels of adult mouse and human skeletal muscles. When delivered through the arterial circulation, MABs cross the blood vessel wall and participate in skeletal muscle regeneration, leading to an amelioration of muscular dystrophies in different preclinical animal models. As such, human MABs have been used under clinical-grade conditions for a Phase I/II clinical trial for Duchenne muscular dystrophy, just concluded. Although some pericyte markers can be used to identify mouse and human MABs, no single unequivocal marker can be used to isolate MABs. As a result, MABs are mainly defined by their isolation method and functional properties. This chapter provides detailed methods for isolation, culture, and characterization of MABs in light of the recent identification of a new marker, PW1/Peg3, to screen and identify competent MABs before their use in cell therapy.