Yuriguchi Minoru, Aoki Hitomi, Taguchi Nobuhiko, Kunisada Takahiro
Department of Tissue and Organ Development, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu 5011194, Japan.
Department of Tissue and Organ Development, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu 5011194, Japan; General Reearch & Development Institute, Hoyu Co., Ltd., 1-12, Roboku, Nagakute, Aichi 4801136, Japan.
J Dermatol Sci. 2016 Oct;84(1):80-87. doi: 10.1016/j.jdermsci.2016.07.004. Epub 2016 Jul 6.
After severe wounding, hair follicles were known to be regenerated de novo along with the re-epithelialization. However, the regenerated hairs lack pigmentation.
We aimed to find out the condition to regenerate pigmented hairs after severe wounding.
De novo hair regeneration was observed during the re-epithelialization process after the full thickness excision of dorsal skin. Hair pigmentation mechanism was assessed by the modulation of Wnt and Kit signalings.
Stable regeneration of pigmented hairs was demonstrated when a wound was created to the mice during the anagen stage of the hair cycle. A significant increase in the number of melanocyte stem cells in the postnatal 1st anagen interfollicular skin of 5-week-old mice was observed. An increase of Wnt7a of the keratinocytes was observed in the skin at this stage, which may direct melanocyte stem cells to produce pigmented hairs in the regenerating follicles. This was supported by the finding that transgenic mice expressing the melanocyte stimulatory factor Kitl in their skin promoted the regeneration of pigmented hairs irrespective of the stage of the hair cycle.
Our results provide a new insight into the intimate regulation process between two follicular stem cell systems, keratinocyte stem cells and melanocyte stem cells, during de novo hair regeneration after wounding.
严重创伤后，毛囊可随着再上皮化过程从头再生。然而，再生毛发缺乏色素沉着。
我们旨在找出严重创伤后再生有色素毛发的条件。
在背部皮肤全层切除后的再上皮化过程中观察从头发生的毛发再生。通过调节Wnt和Kit信号通路评估毛发色素沉着机制。
当在毛发周期的生长期对小鼠造成伤口时，可实现有色素毛发的稳定再生。观察到5周龄小鼠出生后第一个生长期毛囊间皮肤中黑素细胞干细胞数量显著增加。在此阶段的皮肤中观察到角质形成细胞的Wnt7a增加，这可能引导黑素细胞干细胞在再生毛囊中产生有色素的毛发。表达黑素细胞刺激因子Kitl的转基因小鼠在其皮肤中促进有色素毛发的再生，而与毛发周期阶段无关，这一发现支持了上述观点。
我们的结果为创伤后从头发生毛发再生过程中两种毛囊干细胞系统，即角质形成细胞干细胞和黑素细胞干细胞之间的密切调节过程提供了新的见解。
