激活EGFL6/PAX6促进成熟角膜上皮细胞逆向分化为干细胞

角膜上皮干细胞（CESC）失代偿是致盲性眼病关键发病环节，诱导自体细胞分化为CESC是临床上治疗的主要策略。已知干细胞微环境决定其分化方向，但成熟角膜上皮细胞（MCEC）逆向分化为CESC的调控机制依然不明。PAX6上调是角膜缘微环境细胞（LNC）支持CESC的关键因素，免疫共沉淀结果提示EGFL6与PAX6相互正向调节。申请人发现：LNC及三维基质胶可诱导MCEC逆向分化为CESC；结膜下注射移植LNC可减轻碱烧伤引起的CESC失代偿，作用优于骨髓来源的间充质干细胞（BMMSC）；LNC的EGFL6表达量是BMMSC的272.3倍。申请人推测：EGFL6/PAX6通路激活可能是MCEC逆向分化为CESC的关键信号。本课题拟利用LNC+三维基质胶系统，诱导MCEC逆向分化为CESC，建立稳定有效方法，阐明EGFL6/PAX6信号通路在其中发挥的具体作用，为治疗CESC失代偿提供新思路。

Corneal epithelial stem cell (CESC) decompensation is the key pathogenesis of blinding eye disease. Inducing the differentiation of autologous cells into CESC is the main clinical strategy. It is known that the stem cell microenvironment determines the direction of stem cell differentiation, however, the regulatory mechanism of the reverse differentiation of mature corneal epithelial cells (MCEC) into CESC is still unknown. The up-regulation of PAX6 is a key factor in supporting the CESC by limbal microenvironment cells (LNC), and the results of co-immunoprecipitation suggest that EGFL6 and PAX6 positively regulate each other. The applicant's previous research found that: LNC and three-dimensional Matrigel can induce the reverse differentiation of MCEC into CESC; subconjunctival transplant of LNC can reduce the decompensation of CESC that caused by alkali burn, and its effect is better than that of bone marrow-derived mesenchymal stem cells (BMMSC); the EGFL6 expression of LNC is 272.3 times that of BMMSC. We speculate that EGFL6 / PAX6 signaling pathway activation may be the key signal for the reverse differentiation of MCEC into CESC. Therefore, this project intends to use LNC and three-dimensional Matrigel to simulate the microenvironment of CESC stem cells in vitro to induce the reverse differentiation of MCEC into CESC, establish a stable and effective method, clarify the specific role played by the EGFL6 / PAX6 signaling pathway, and provide new ideas for the treatment of CESC decompensation.