Cdc42调节毛囊外根鞘细胞分化影响触须毛囊发育的信号机制研究

Understandings the signaling pathways in governing the development of hair follicle is very important. Cdc42 is an ubiquitously expressed small GTPase of the Rho family, regulating cell morphogenesis, cell proliferation and differentiation. To analyze the function of Cdc42 in hair follicle morphogenesis, we generated mice with a hair outer root sheath cells-restricted deletion of the Cdc42 gene. The knocked-out mice develop abnormal vibrissae phenotypes, showed that Cdc42 is crucial for the development and growth of vibrissae follicle. In this study, the samples on the key embryogenesis periods of vibrissa follicle will be selected to examine the hair follicle structure and differentiation in vivo. Then, the role of Cdc42 in hair outer root sheath cells will be investigated in vitro. GATA-3 is a pivotal regulator of hair outer root sheath cells differentiation. In the last part of our study, the lentivirus vectors of GATA-3 will be built to discuss the signaling networks of Cdc42 in the regulation of hair outer root sheath cell differentiation. The completion of this work will further clarify the signaling networks of hair follicle development, provide therapeutic targets and corresponding theoretical basis for the treatment of human hair follicle related diseases.

毛发在胚胎时期开始发育，出生后大部分毛发不可再生。对毛囊胚胎发育的信号机制研究，有助于阐明毛囊再生分子机制，为秃发等毛发相关疾病治疗奠定基础。Cdc42是小G蛋白Rho家族成员，作为分子开关在调控细胞形态发生、增殖与分化中起重要作用。本课题组前期利用Cre/Loxp系统，构建Cdc42条件性基因敲除小鼠，发现小鼠出生时触须缩短，进一步研究发现，基因敲除小鼠触须毛囊分化异常，提示：Cdc42可能通过调节分化影响触须毛囊胚胎发育。本课题拟选取胚胎发育不同时间点触须毛囊样本进行电镜和光镜水平分析，在动物水平阐明Cdc42对触须毛囊胚胎发育的功能影响；进一步，在细胞学水平研究Cdc42对毛囊外根鞘细胞生物学功能的调控作用；最后，聚焦调节毛囊分化的转录因子GATA-3，探讨Cdc42调节毛囊外根鞘细胞分化的信号机制。本研究的完成将会进一步阐明毛囊胚胎发育的信号机制，为毛囊相关疾病的治疗提供理论依据。

毛发在胚胎时期开始发育，出生后大部分毛发不可再生。对毛囊胚胎发育的信号机制研究，有助于阐明毛囊再生分子机制，为秃发等毛发相关疾病治疗提供新思路。Cdc42是小G蛋白Rho GTPase家族成员，作为分子开关在细胞形态发生、增殖和分化中起调控作用。本课题组前期利用Cre/Loxp系统构建Cdc42条件性基因敲除小鼠，本研究选取胚胎发育不同时间点触须毛囊样本进行电镜和光镜水平分析，发现Cdc42不影响毛囊基板的形成，但参与调节毛囊分化；运用转录谱测序发现，下调差异基因在中间纤维结构显著富集，进一步研究发现富集差异基因为毛囊内根鞘和毛干特异性角蛋白，揭示Cdc42对毛囊内根鞘和毛干分化起重要调节作用。进而聚焦调节毛囊分化的关键信号，利用Cdc42相关慢病毒载体，在细胞学水平研究发现Cdc42可能通过wnt7a和msx1影响keratin27和keratin71的表达，影响毛囊内根鞘和毛干的分化，进而影响小鼠触须毛囊胚胎发育。本研究的完成为进一步阐明毛囊胚胎发育的信号机制提供了理论依据。