From the USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033.
From the USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
J Biol Chem. 2018 Mar 9;293(10):3758-3769. doi: 10.1074/jbc.RA117.000295. Epub 2018 Jan 23.
Investigating stimulation of endogenous wound healing in corneal endothelial cells (CECs) may help address the global shortage of donor corneas by decreasing the number of transplants performed for blindness because of endothelial dysfunction. We previously reported that IL-1β stimulation leads to fibroblast growth factor (FGF2) expression, enhancing migration and proliferation of mammalian CECs. However, FGF2 also promotes the endothelial-mesenchymal transition, which can lead to retrocorneal membrane formation and blindness. This prompted us to investigate downstream FGF2 signaling targets that could be manipulated to prevent retrocorneal membrane formation. FGF2 stimulation altered cell morphology and induced expression of mesenchymal transition marker genes such as (), , (), and This, in turn, induced expression of fibronectin, vimentin, and type I collagen, and suppressed E-cadherin in CECs and siRNA-mediated SNAI1 knockdown revealed that SNAI1 induces ZEB1 expression, in turn inducing expression of type I collagen, the major component of retrocorneal membranes, and of cyclin-dependent kinase 2 (CDK2) and cyclin E1, promoting cell proliferation. siRNA-mediated knockdown of or , but not of , inhibited FGF2-dependent expression of fibronectin, vimentin, and type I collagen and of suppression of E-cadherin expression. We conclude that SNAI1 is a key regulator of FGF2-dependent mesenchymal transition in human corneal endothelium, with ZEB1 regulating type I collagen expression and CDK2 regulating cell proliferation. These results suggest that SNAI1 promotes fibrosis and cell proliferation in human corneal endothelium through ZEB1 and CDK2.
研究刺激角膜内皮细胞（CEC）内源性伤口愈合，可能有助于减少因内皮功能障碍而导致失明的移植数量，从而解决全球供体角膜短缺的问题。我们之前曾报道过，IL-1β刺激会导致成纤维细胞生长因子（FGF2）表达，从而增强哺乳动物 CEC 的迁移和增殖。然而，FGF2 也促进内皮-间充质转化，这可能导致后弹力膜形成和失明。这促使我们研究 FGF2 信号下游的靶标，这些靶标可以被操纵以防止后弹力膜形成。FGF2 刺激改变了细胞形态，并诱导间充质转化标记基因的表达，如、、和。这反过来又诱导了纤维连接蛋白、波形蛋白和 I 型胶原的表达，并抑制了 CEC 中的 E-钙黏蛋白。和 siRNA 介导的 SNAI1 敲低显示，SNAI1 诱导 ZEB1 表达，进而诱导 I 型胶原的表达，I 型胶原是后弹力膜的主要成分，以及细胞周期蛋白依赖性激酶 2（CDK2）和细胞周期蛋白 E1 的表达，促进细胞增殖。siRNA 介导的或的敲低，但不是的敲低，抑制了 FGF2 依赖的纤维连接蛋白、波形蛋白和 I 型胶原的表达以及 E-钙黏蛋白表达的抑制。我们得出结论，SNAI1 是 FGF2 依赖性人角膜内皮细胞间充质转化的关键调节因子，ZEB1 调节 I 型胶原表达，CDK2 调节细胞增殖。这些结果表明，SNAI1 通过 ZEB1 和 CDK2 促进人角膜内皮细胞的纤维化和细胞增殖。
