Sun Chao, Lei Tie-Chi
Department of Dermatology,Renmin Hospital of Wuhan University,Wuhan 430060,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2021 Aug;43(4):607-611. doi: 10.3881/j.issn.1000-503X.12594.
There is growing evidence that dermal papilla cells(DPCs)act as the organizing center to induce the cyclic hair regeneration.On one hand,DPCs secrete cytokines or growth factors to regulate the differentiation,proliferation,and migration of epithelial stem cells(EpSCs)and melanocyte stem cells(MeSCs)residing in the bulge region.On the other hand,DPCs manipulate the microenvironment(also termed as niche)for both EpSCs and MeSCs,such as the size of dermal papilla,the distance between dermal papilla and the bulge region,and the lymphatic drainage and sympathetic nerve innervation surrounding the bulge region,thereby orchestrating the cycling hair growth.Recent studies have demonstrated at least four subpopulations existing in dermal papillae,which induce the unilineage transit-amplifying epithelial cells to form the concentric multilayers of hair shafts and sheaths.In addition,emerging study has indicated that sustained psychological stress potentially leads to hyperactivation of the sympathetic nerves that innervate the bulge region.The large amount of norepinephrine released by the nerve endings forces MeSCs to rapidly and abnormally proliferate,resultantly causing the depletion of MeSC pool and the loss of hair pigment.Understanding the molecular regulation of hair growth and pigmentation by DPCs holds substantial promise for the future use of cultured DPCs to treat hair loss.
越来越多的证据表明，真皮乳头细胞（DPCs）作为诱导周期性毛发再生的组织中心。一方面，DPCs分泌细胞因子或生长因子来调节位于毛囊隆突区的上皮干细胞（EpSCs）和黑素细胞干细胞（MeSCs）的分化、增殖和迁移。另一方面，DPCs为EpSCs和MeSCs操纵微环境（也称为生态位），如真皮乳头的大小、真皮乳头与隆突区之间的距离，以及隆突区周围的淋巴引流和交感神经支配，从而协调毛发的周期性生长。最近的研究表明，真皮乳头中至少存在四个亚群，它们诱导单谱系过渡放大上皮细胞形成毛发轴和毛囊鞘的同心多层结构。此外，新出现的研究表明，持续的心理压力可能导致支配隆突区的交感神经过度激活。神经末梢释放的大量去甲肾上腺素迫使MeSCs快速异常增殖，最终导致MeSC库的耗竭和毛发色素的丧失。了解DPCs对毛发生长和色素沉着的分子调控，对于未来使用培养的DPCs治疗脱发具有重要的前景。
