Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Qiaokou District, Wuhan, 430030, China.
J Mol Histol. 2018 Jun;49(3):303-316. doi: 10.1007/s10735-018-9769-0. Epub 2018 Apr 9.
The nail is a continuous skin appendage. Cells located around the nails, which display coordinated homeostatic dynamics and release a flow of stem cells in response to regeneration, have been identified in mice. However, very few studies regarding human nail stem cells exist in the literature. Using specimens isolated from humans, we detected an unreported population of cells within the basal layer of postnatal human nail proximal folds (NPFs) and the nail matrix around the nail root. These cells were multi-expressing and expressed stem cell markers, such as keratin 15 (K15), keratin 14 (K14), keratin 19 (K19), CD29, CD34, and leucine-rich repeat-containing G protein-coupled receptor 6 (Lgr6). These cells were very similar to mouse nail stem cells in terms of cell marker expression and their location within the nail. We also found that the putative nail stem cells maintained their abundance with advancing age, but cell proliferation and nail growth rate were decreased on comparison of young and aged specimens. To summarize, we found a putative population of stem cells in postnatal human nails located at NPFs and the nail matrix. These cells may have potential for cell differentiation and be capable of responding to injury, and were retained, but may be hypofunctional during aging.
指甲是一种连续的皮肤附属物。在小鼠中已经鉴定出位于指甲周围的细胞，这些细胞显示出协调的动态平衡，并在受到再生刺激时释放出干细胞流。然而，文献中关于人类指甲干细胞的研究很少。我们使用从人类分离的标本，在出生后人类指甲近端褶（NPF）和甲根周围的甲母质的基底层中检测到一个未被报道的细胞群。这些细胞是多表达的，并表达干细胞标志物，如角蛋白 15（K15）、角蛋白 14（K14）、角蛋白 19（K19）、CD29、CD34 和富含亮氨酸重复的 G 蛋白偶联受体 6（Lgr6）。这些细胞在细胞标志物表达和在指甲中的位置方面与小鼠指甲干细胞非常相似。我们还发现，假定的指甲干细胞随着年龄的增长而保持其丰度，但与年轻标本相比，细胞增殖和指甲生长速度下降。总之，我们在出生后的人类指甲中发现了位于 NPF 和甲母质的假定干细胞群体。这些细胞可能具有细胞分化的潜力，能够对损伤做出反应，并在保留的同时，在衰老过程中可能功能低下。
