CASP3 and Sepsis: To investigate if MSCs had a protective effect on satellite cells, we sorted MSCs from non-septic C57Bl/6 bone marrow by FACS (CD45−, Ter119−, PDGFR1a+ and Sca1+)35 and injected 300,000 cells intramuscularly in 15 μl of 0.9% NaCl, 6 h after induction of sepsis and injury (Fig. 4a).