Aging affects the in vivo regenerative potential of human mesoangioblasts

Summary Sarcopenia is the age‐related loss of muscle mass, strength, and function. Although the role of human satellite cells ( SC s) as adult skeletal muscle stem cells has been deeply investigated, little is known about the impact of aging on muscle interstitial stem cells. Here, we isolated the non‐ SC CD 56 – fraction from human muscle biopsies of young and elderly subjects. The elderly interstitial cell population contained a higher number of CD 15 + and PDGFR α + cells when compared to young samples. In addition, we found that the CD 56 – / ALP + cells were well represented as a multipotent stem cell population inside the CD 56 – fraction. CD 56 – / ALP + / CD 15 – cells were clonogenic, and since they were myogenic and expressed NG 2, α‐ SMA and PDGFR β can be considered mesoangioblasts ( MAB s). Interestingly, elderly MAB s displayed a dramatic impairment in the myogenic differentiation ability in vitro and when transplanted in dystrophic immunodeficient Sgcb‐null Rag2‐null γ c‐null mice. In addition, elderly MAB s proliferated less, but yet retained other multilineage capabilities. Overall, our results indicate that aging negatively impacted on the regenerative potential of MAB s and this should be carefully considered for potential therapeutic applications of MAB s.