Jahoda Colin A B, Whitehouse J, Reynolds Amanda J, Hole Nicholas
School of Biological and Biomedical Sciences, University of Durham, Durham, UK.
Exp Dermatol. 2003 Dec;12(6):849-59. doi: 10.1111/j.0906-6705.2003.00161.x.
The adult hair follicle dermal papilla (DP) and dermal sheath (DS) cells are developmentally active cell populations with a proven role in adult hair follicle-cycling activity and unique inductive powers. In stem cell biology, the hair follicle epithelium has recently been the subject of a great deal of investigation, but up to now, the follicle dermis has been largely overlooked as a source of stem cells. Following the sporadic appearance of muscle, lipid and bone-type cells in discretely isolated follicle DP and DS cell primary cultures, we demonstrated that cultured papilla and sheath cell lines were capable of being directed to lipid and bone differentiation. Subsequently, for the first time, we produced clonal DP and DS lines that had extended proliferative capabilities. Dye exclusion has been reported to be an identifying feature of stem cells; therefore, clonal papilla and sheath lines with differing capacity to exclude rhodamine 123 were cultured in medium known to induce adipocyte and osteocyte differentiation. Both DS- and DP-derived clones showed the capacity to make lipid and to produce calcified material; however, different clones had varied behaviour and there was no obvious correlation between their stem cell capabilities and dye exclusion or selected gene expression markers. As a highly accessible source, capable of being discretely isolated, the follicle has important potentially as a stem cell source for tissue engineering and cell therapy purposes. It will also be interesting to compare follicle dermal stem cell properties with the broader stem cell capabilities discovered in skin dermis and investigate whether, as we believe, the follicle is a key dermal stem cell niche. Finally, the discovery of stem cells in the dermis may have implications for certain pathologies in which abnormal differentiation occurs in the skin.
成人毛囊真皮乳头（DP）和真皮鞘（DS）细胞是具有发育活性的细胞群体，在成人毛囊循环活动中发挥着已被证实的作用，并且具有独特的诱导能力。在干细胞生物学领域，毛囊上皮最近成为大量研究的对象，但到目前为止，毛囊真皮在很大程度上被忽视，未被视为干细胞的来源。在离散分离的毛囊DP和DS细胞原代培养物中偶尔出现肌肉、脂质和骨类型细胞后，我们证明培养的乳头和鞘细胞系能够被定向诱导分化为脂质和骨细胞。随后，我们首次产生了具有延长增殖能力的克隆DP和DS细胞系。据报道，染料排斥是干细胞的一个识别特征；因此，将具有不同罗丹明123排斥能力的克隆乳头和鞘细胞系培养在已知可诱导脂肪细胞和骨细胞分化的培养基中。源自DS和DP的克隆均显示出形成脂质和产生钙化物质的能力；然而，不同的克隆表现各异，它们的干细胞能力与染料排斥或所选基因表达标志物之间没有明显的相关性。作为一种易于获取且能够离散分离的来源，毛囊作为组织工程和细胞治疗目的的干细胞来源具有重要的潜在价值。将毛囊真皮干细胞特性与在皮肤真皮中发现的更广泛的干细胞能力进行比较，并研究毛囊是否如我们所认为的那样是关键真皮干细胞生态位，也将是很有趣的。最后，真皮中干细胞的发现可能对皮肤中发生异常分化的某些病理学具有启示意义。
