Molecular Biology and Genetics, Cornell University, Ithaca, United States.
Elife. 2019 Jul 25;8:e45977. doi: 10.7554/eLife.45977.
Skin vasculature cross-talking with hair follicle stem cells (HFSCs) is poorly understood. Skin vasculature undergoes dramatic remodeling during adult mouse hair cycle. Specifically, a horizontal plexus under the secondary hair germ (HPuHG) transiently neighbors the HFSC activation zone during the quiescence phase (telogen). Increased density of HPuHG can be induced by reciprocal mutations in the epithelium () and endothelium () in adult mice, and is accompanied by prolonged HFSC quiescence and by delayed entry and progression into the hair growth phase (anagen). Suggestively, skin vasculature produces BMP4, a well-established HFSC quiescence-inducing factor, thus contributing to a proliferation-inhibitory environment near the HFSC. Conversely, the HFSC activator Runx1 regulates secreted proteins with previously demonstrated roles in vasculature remodeling. We suggest a working model in which coordinated remodeling and molecular cross-talking of the adult epithelial and endothelial skin compartments modulate timing of HFSC activation from quiescence for proper tissue homeostasis of adult skin.
皮肤脉管系统与毛囊干细胞（HFSCs）之间的相互作用尚不清楚。在成年小鼠的毛发周期中，皮肤脉管系统会经历剧烈的重塑。具体来说，在静止期（休止期），次级毛囊芽（HPuHG）下方的水平丛暂时与 HFSC 激活区相邻。在成年小鼠中，上皮（）和内皮（）的相互突变可诱导 HPuHG 密度增加，并且伴随着 HFSC 静止时间延长，以及进入和进入毛发生长阶段（生长期）的时间延迟。暗示性地，皮肤脉管系统产生 BMP4，这是一种已确立的 HFSC 静止诱导因子，因此有助于 HFSC 附近的增殖抑制环境。相反，HFSC 激活剂 Runx1 调节具有先前证明在血管重塑中作用的分泌蛋白。我们提出了一个工作模型，其中成年上皮和内皮皮肤隔室的协调重塑和分子相互作用调节 HFSC 从静止期激活的时间，以维持成年皮肤的组织内稳态。
