小G蛋白家族成员Cdc42对毛囊bulge区干细胞的维持和增殖作用及机制研究

The morbidity of alopecia is very high, that research on effective treatment is Necessary. The hair follicle cycle depend on hair follicle stem cell, which is hotspot for alopecia treatment and hair regeneration. It is reported that β-catenin control the way of differentiation of hair follicle stem cells. It can improve hair follicle stem cells into proliferating phase and starting hair cycle. We have produced skin keratinocyte cdc42 knockout mouse, and found that after the second telogen cdc42 knockout mouse progressively depilated, and hair cycle disappeared, and hair follicle stem cells in bulge exhausted. For further research, we found that there are distinct weaken of normal proliferation and irritate proliferation of hair follicle stem cells, and there are impaired regeneration of hair shaft. Then we assume that cdc42 have the improved functions in hair follicle stem cells maintenance and proliferation, and which improved function mediate by β-catenin. We want to verificate our hypothesis and make clear the mechanism using model of cdc42 knockout mouse and cdc42 knockout cells and using β-catenin inhibitor and promoter. I hope this research would provide support for hair regeneration. And we hope provide new treatment target for alopecia and other skin diseases.

脱发疾病发病率高，研究其机制意义极大。毛囊周期及毛囊干细胞异常是脱发的重要原因，也是研究脱发治疗和毛发再生的热点。文献证实β-catenin决定毛囊干细胞分化途径促进其增殖。前期我们用cre/loxp基因敲除技术构建了皮肤角质细胞cdc42基因敲除小鼠，发现敲除小鼠毛发渐脱落；毛发周期循环消失；毛囊干细胞耗竭，自然和刺激增殖能力明显减弱，拔毛后毛干萌出障碍。据此假设cdc42对毛囊干细胞维持和增殖有促进作用，且此作用由β-catenin介导。拟进而用cdc42基因敲除和cdc42过表达动物和细胞模型，通过在毛囊周期的关键时间点对毛囊干细胞和细胞增殖双重标记，结合流式细胞分选，细胞周期和细胞克隆形成检测，明确cdc42对毛囊干细胞的维持和增殖作用；进而在前期有差异的时间点对β-catenin表达进行检测，结合β-catenin的促进剂，正反两方面验证假说。为促进毛发再生和治疗脱发病提供新靶点

本项目利用cre/loxp基因敲除技术构建了皮肤角质细胞cdc42基因敲除小鼠，发现基因敲除小鼠毛发渐脱落；毛发周期循环消失；经过对毛囊干细胞的免疫荧光、wholemount标记，荧光显微镜和激光共聚焦显微镜观察发现毛囊干细胞耗竭；经过对其自然和受刺激后增殖能力等实验发现：毛囊干细胞动员和增殖能力明显减弱，拔毛后毛干萌出障碍。据此得出：小G蛋白家族成员Cdc42对毛囊bulge区干细胞的维持和动员、增殖能力均有促进作用，经过对Cdc42相关信号β-catenin的检测发现：此作用可能由β-catenin介导。本研究成果为毛囊周期及毛囊干细胞异常引起的脱发的机制研究提供了实验依据。可能为促进毛发再生和治疗脱发病提供新靶点。