Identification and Characterization of the Dermal Panniculus Carnosus Muscle Stem Cells

Summary

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.

Graphical Abstract

Highlights

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  PC satellite cells originate from Myf5 ⁺ , Pax3/Pax7 ⁺ cell lineages

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  Skin and muscle wounding increase PC myofiber turnover

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  Donor bone marrow cells repopulate the PC satellite niche after BMT

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  Dermis-derived myogenesis originates from the PC satellite cell population

Abstract

In this article, Izeta, García-Parra, and colleagues show that the panniculus carnosus (PC) muscle satellite cells originate from a somitic Pax3/7-positive and Myf5-positive lineage, like limb and body wall skeletal muscles. Through lineage tracing, cell sorting, and ablation experiments they unambiguously demonstrate that the only dermal cells with a myogenic potential are the PC satellite cells and their progeny.