新生鼠皮肤细胞以小室法移植后构建毛囊发育模型

Implantation of newborn mice skin cells with chamber method to construct a model of hair follicle development

目的构建一种简便、可靠、直观的毛囊发育模型以检测毛囊细胞的毛发诱导能力，探讨毛囊形态发生和周期循环的分子机制。方法于裸鼠背部植入一开放小室，将新生C57BL／6鼠皮肤中的真皮和表皮细胞分离，并按一定的比例混合移植至小室内，1周后拆除小室，观察毛发形成及毛发拔除后的再生情况。结果细胞移植后1周，创面湿润无明显收缩，中间有淡红色半透明组织形成。移植后2周，创面完全愈合。移植后3周有黑色毛发长出皮肤。移植后4周，浓密黑色毛发垂直于皮肤表面生长，石蜡切片HE染色见毛囊结构发育完整。毛发拔除后1周能够再生出新的毛发。细胞以不同的比例移植，真皮细胞数量为1×10^7、表皮细胞数量降至1×10^6时，毛囊重构的效率并无明显改变。表皮细胞数量为1×10^7、真皮细胞数量降至5×10^6或者更少时，再生毛发的数量明显减少，两者单独移植均无毛发生长。结论新生鼠皮肤细胞以小室法移植后可以构建毛囊发育的完整模型，并可用于检测毛囊细胞的诱导能力，以研究毛囊形态的发生和周期循环的分子机制。

Objective To construct a convenient, reliable and visual model of hair follicle development to test the hair-inductive potential of follicular ceils and investigate the molecular mechanism regulating hair follicle morphogenesis and cycling. Methods An open chamber was transplanted into the nude mice dorsal skin, dermal and epidermal cells isolated from newborn C57BL/6 mice skin were mixed at a specific ratio and then injected into the chamber together, 1 week after transplantation, the chamber was removed, and then, hair formation and regeneration after hair plucking was observed. Results 1 week after cells implantation, the wound was moist without apparent contraction and among that pink and translucent tissue was formed. 2 weeks after implantation, the wound healed completely. 3 weeks after implantation,black hair grew from the skin was observed. 4 weeks after implantation,thick and black hair grew from the skin vertically. Completely developed structure of hair follicle was observed with paraffin section and HE staining. 1 week after plucking, new hair had regrown. The ratio of cell component was varied, whereas the other component was fixed at 1 × 10^7 cells. When the number of epidermal cells was reduced to 1 × 10^6 cells, the efficiency of hair follicle reconstitution was mostly unchanged. On the other hand, the density of newly formed hair was diminished considerably by reducing the number of dermal cells to 5 × 10^6 cells or lower. Neither epidermal cells nor dermal cells transplanted alone formed hair follicle. Conclusions Newborn mice skin cells transplanted by chamber method can construct a complete model of hair follicle development, which can be used to test the hair-inductive potential of follicular cells and investigate the molecular mechanism regulating hair follicle morphogenesis and cycling.