Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Exp Dermatol. 2021 Apr;30(4):512-521. doi: 10.1111/exd.14204. Epub 2020 Oct 22.
Hair follicles cyclically regenerate throughout adult mammalian life, owing to a resident population of epithelial hair follicle stem cells. Stem cell (SC) activity drives bouts of follicle growth, which are periodically interrupted by follicle regression and rest. These phases and the transitions between them are tightly spatiotemporally coordinated by signalling crosstalk between stem/progenitor cells and the various cell types of the microenvironment, or niche. The dermal papilla (DP) is a cluster of specialized mesenchymal cells that have long been recognized for important niche roles in regulating hair follicle SC activation, as well as progenitor proliferation and differentiation during follicle growth. In addition to the DP, the mesenchyme of the murine pelage follicle is also comprised of a follicle-lining smooth muscle known as the dermal sheath (DS), which has been far less studied than the DP yet may be equally specialized and important for hair cycling. In this review, we define the murine pelage DS in comparison with human DS and discuss recent work that highlights the emergent importance of the DS in the hair follicle SC niche. Last, we examine potential therapeutic applications for the DS in hair regeneration and wound healing.
毛发滤泡在成年哺乳动物的一生中周期性地再生，这要归功于常驻的上皮毛囊干细胞群体。干细胞（SC）活动驱动滤泡生长，这些生长周期性地被滤泡退化和静止所打断。这些阶段以及它们之间的转变，是由干细胞/祖细胞与微环境（或小生境）的各种细胞类型之间的信号串扰紧密时空协调的。真皮乳头（DP）是一簇专门的间充质细胞，长期以来一直被认为在调节毛囊干细胞激活以及滤泡生长过程中祖细胞增殖和分化方面具有重要的小生境作用。除了 DP 之外，鼠类被毛滤泡的间充质还包括一种称为真皮鞘（DS）的滤泡衬里平滑肌，它的研究远不及 DP 多，但它可能同样具有特异性，并且对毛发循环很重要。在这篇综述中，我们将鼠类被毛 DS 与人类 DS 进行了比较，并讨论了最近的工作，这些工作强调了 DS 在毛囊干细胞小生境中的新兴重要性。最后，我们研究了 DS 在毛发再生和伤口愈合中的潜在治疗应用。
