BMP和Wnt信号通路在角巩缘干细胞调控中的作用

Limbal stem cells (LSCs) maintain the stability of ocular surface. Limbal stem cell deficiency (LSCD) is one of the most serious ocular surface disease that could result in blindness. The function of LSCs is controlled by kinds of signalings. Many studies showed that BMP and Wnt signaling were involved in the regulation of stem cells in hematopoietic system，skin and intestinal canal. Our previous data showed that Genes of BMP and Wnt signaling were expreesed by LSCs, and the clonal growth on 3T3 of LSCs was controlled by BMP and Wnt signaling. Since the efficiency clonal growth and morphology of clone are important markers of stem cells, we predict that the quiescence, self- renewal and fate decision of LSCs are also controlled by BMP and Wnt signaling. In this study, we were further investigate the role of BMP and Wnt signaling in regulation of LSCs through in vitro and in vivo experiments, from the level of molecule, cell and integrity. The ultimate goal of this study is to improve the efficiency of LSCs transplantation in LSCD treatment.

角巩缘干细胞(LSCs)是维持正常眼表功能的关键，其缺乏将导致致盲性眼病。LSCs生长、存活、转归受到各种信号通路的调控。研究表明，BMP和Wnt信号通路对造血干细胞、皮肤干细胞以及肠道干细胞起着关键性的调控作用。我们前期研究表明，BMP和Wnt信号通路相关基因在LSCs均有表达，并且BMP和Wnt信号通路对LSCs的克隆生长能力有明显的调控作用。由于克隆生长是判断干细胞状态的一项重要指标，所以我们推测LSCs静止、自我更新以及定向分化同样受到BMP和Wnt信号通路调控，但是BMP和Wnt信号通路如何整合调控LSCs需进一步研究。本项目拟通过严谨设计的体内体外实验，通过大鼠细胞培养模型和大鼠角膜缘干细胞损伤模型，在分子、细胞和整体水平阐明BMP和Wnt信号通路对LSCs 的调控作用，为临床应用LSCs治疗LSCD 奠定坚实的理论基础。

角膜缘干细胞(LSCs)是维持正常眼表功能的关键，其缺乏将导致致盲性眼病。LSCs生长、存活、转归受到各种信号通路的调控。研究表明，BMP和Wnt信号通路对造血干细胞、皮肤干细胞以及肠道干细胞起着关键性的调控作用。我们前期研究表明，BMP和Wnt信号通路相关基因在LSCs均有表达，并且BMP和Wnt信号通路对LSCs的克隆生长能力有明显的调控作用。由于克隆生长是判断干细胞状态的一项重要指标，所以我们推测LSCs静止、自我更新以及定向分化同样受到BMP和Wnt信号通路调控。本课题利用3D-Matrigel培养体系，通过在体外激活或者阻断BMP和Wnt信号通路分析BMP和Wnt信号通路对角膜缘干细胞功能的调控，并通过角膜缘干细胞损伤模型，验证LSCs移植对干细胞缺乏的治疗效果及其与信号通路的关系。我们体外实验结果显示：BMP信号通路和Wnt信号通路不参与角膜缘干细胞的干性调控，而是调控干细胞的功能，BMP信号通路激活使得角膜缘干细胞处于静止状态，而当Wnt信号通路激活时，角膜缘干细胞处于自我更新。在后续的体内实验中，我们发现移植Wnt信号通路激活的角膜缘干细胞有利于角膜缘干细胞损伤的修复。这将为角膜缘干细胞缺乏的眼表重建带来新的契机。