Boundary Caps Give Rise to Neurogenic Stem Cells and Terminal Glia in the Skin

Nerve-associated neural crest: peripheral glial cells generate multiple fates in the body

Recent studies demonstrated that neural crest-derived Schwann cell precursors (SCPs) dwelling in the nerves are multipotent and can be recruited in the local tissue to provide building blocks of neural crest-derived nature. The variety of fates produced by SCPs is widening with every year and currently includes melanocytes/melanophores, parasympathetic and enteric neurons, endoneural fibroblast, mesenchymal stem cells and, of course, mature Schwann cells of different subtypes. However, it is still unclear if SCPs are, in fact, nerve-dwelling population of the neural crest or they are rather a different, more specialized, cell type. This review outlines the field and focuses on the capacity of nerve-associated glial progenitors to contribute to the development and regeneration of numerous tissues in various groups of vertebrates.

Minimizing Skin Scarring through Biomaterial Design

Wound healing continues to be a major burden to patients, though research in the field has expanded significantly. Due to an aging population and increasing comorbid conditions, the cost of chronic wounds is expected to increase for patients and the U.S. healthcare system alike. With this knowledge, the number of engineered products to facilitate wound healing has also increased dramatically, with some already in clinical use. In this review, the major biomaterials used to facilitate skin wound healing will be examined, with particular attention allocated to the science behind their development. Experimental therapies will also be evaluated.

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.

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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