Identification and characterization of the dermal Panniculus carnosus muscle stem cells

et al.The dermal Panniculus carnosus (PC) muscle is important for wound contraction in lower mammals and represents an interesting model of muscle regeneration due to its high cell turnover. The resident satellite cells (the bona fide muscle stem cells) remain poorly characterized. Here we analyzed PC satellite cells with regard to developmental origin and purported function. Lineage tracing shows that they originate in Myf5, Pax3/Pax7 cell populations. Skin and muscle wounding increased PC myofiber turnover, with the satellite cell progeny being involved in muscle regeneration but with no detectable contribution to the wound-bed myofibroblasts. Since hematopoietic stem cells fuse to PC myofibers in the absence of injury, we also studied the contribution of bone marrow-derived cells to the PC satellite cell compartment, demonstrating that cells of donor origin are capable of repopulating the PC muscle stem cell niche after irradiation and bone marrow transplantation but may not fully acquire the relevant myogenic commitment.This work was supported by grants from Instituto de Salud Carlos III (ISCIII; PS09/00660, PI13/02172, and PI14/7436), Gobierno Vasco (SAIO12-PE12BN008) from Spain and the European Union (POCTEFA-INTERREG IV A program; REFBIO13/BIOD/006 and REFBIO13/BIOD/009). N.N.G. received a studentship from the Department of Education, University and Research of the Basque Government (PRE2013-1-1168). P.G.P. received fellowships from the Department of Health of the Basque government (2013011016), EMBO (Short-Term; ASTF 542–2013), and Boehringer Ingelheim Fonds. M.L.M. and J.J.C. were supported by a Marie Curie Career Integration Grant from the European Commission (PEOPLE-CIG/1590). A.I. was supported by the Programa I3SNS (CES09/015) from ISCIII and by Osakidetza-Servicio Vasco de Salud (Spain).Peer Reviewe

Identification and characterization of the dermal Panniculus carnosus muscle stem cells

The dermal Panniculus carnosus (PC) muscle is important for wound contraction in lower mammals and represents an interesting model of muscle regeneration due to its high cell turnover. The resident satellite cells (the bona fide muscle stem cells) remain poorly characterized. Here we analyzed PC satellite cells with regard to developmental origin and purported function. Lineage tracing shows that they originate in Myf5(+), Pax3/Pax7(+) cell populations. Skin and muscle wounding increased PC myofiber turnover, with the satellite cell progeny being involved in muscle regeneration but with no detectable contribution to the wound-bed myofibroblasts. Since hematopoietic stem cells fuse to PC myofibers in the absence of injury, we also studied the contribution of bone marrow-derived cells to the PC satellite cell compartment, demonstrating that cells of donor origin are capable of repopulating the PC muscle stem cell niche after irradiation and bone marrow transplantation but may not fully acquire the relevant myogenic commitment