Brd4调控角膜上皮干细胞的机理研究

Corneal epithelial stem cells are ultimately responsible for the corneal epithelium under normal circumstances and during wound healing. Our preliminary studies showed that transcription factor Brd4 is related with stemness of the corneal epithelial stem cells. To investigate the function of Brd4 in corneal epithelial cells, current project will be carried out to determine 1) The molecular characteristic of Brd4 gene expression in the corneal epithelial stem cells. 2) The effect of Brd4 on the proliferation and differentiation of the corneal epithelial stem cells in vitro. 3) The effect of Brd4 on physiology of the ocular surface4) The relationship between Brd4 and corneal epithelial stem cell dysfunction (LSCD). This project will help illustrate the mechanism of the homostasis of corneal epithelial stem cell, and to shed new light on the treatment of LSCD. It will also help improve the protocol of ex vivo expansion of corneal epithelial stem cells, as well as the corneal epithelium tissue engineering.

角膜上皮干细胞是角膜上皮生发的源泉，也是角膜屏障功能维持的必要条件。我们的前期研究表明，Brd4蛋白参与维持角膜上皮干细胞的正常表型。为了深入探究Brd4影响角膜上皮干细胞的分子机理，本项目将进行如下研究(一)角膜上皮干细胞中Brd4的分子及生化特征；（二）Brd4对角膜上皮干细胞增殖分化的影响；（三）Brd4对眼表生理功能的影响；（四）Brd4与角膜上皮干细胞功能障碍(limbal stem cell dysfunction，LSCD)发生的相关性。本研究的开展有利于阐明角膜上皮干细胞稳态维持的机理，为LSCD的治疗提供新的思路和方法，也将有助于改善角膜上皮干细胞体外扩增技术以及组织工程角膜上皮构建技术。

本课题的目的在于探讨Brd4蛋白对与角膜上皮干细胞特性维持的相关性及调控机制。本项目通过研究发现：（1）Brd4主要表达于角膜缘基底层上皮细胞，与多种角膜上皮细胞标记物Abcg5、p63、K14相比，对角膜上皮干细胞的识别效率更高；（2）Brd4的含量与角膜上皮干细胞干性程度成正相关；（3）Brd4的正常功能决定了角膜上皮干细胞的增殖潜能；（4）Brd4受抑可诱导角膜上皮干细胞分化；（5）Brd5参与了眼表上皮的损伤修复应答反应，环境污染物PM2.5点眼可诱导角结膜上皮细胞中Brd4含量显著上调。本研究的开展有利于阐明角膜上皮干细胞稳态维持的机理，为LSCD的治疗提供了新的思路和方法，也将有助于改善角膜上皮干细胞体外扩增技术以及组织工程角膜上皮构建技术。