Li Hui, Yang Jing
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
J Ocul Pharmacol Ther. 2025 May 5. doi: 10.1089/jop.2024.0210.
Diabetic patients have been proven to have higher incidence of subcapsular cataract, and the subcapsular cataract formation has a closed link with epithelial-to-mesenchymal transition (EMT). EMT in numerous tissues can be regulated by the endoplasmic reticulum stress response (ER stress). In this study, we aim to explore the role of ER stress high glucose (HG)-induced EMT of human lens epithelial cells (HLECs). The human lens epithelial cell line SRA01/04 was treated under HG conditions, and 4-phenylbutyrate (PBA) or tauroursodeoxycholic acid (TUDCA) was used for 24 h to restore endoplasmic reticulum (ER) homeostasis under HG condition. The long axis and the aspect ratio of the cells were analyzed with ImageJ software to evaluate the morphology of the cells. Western blot analysis and immunofluorescence staining were applied to measure ER stress makers: glucose-regulated protein 78 (GRP78), phosphorylation of eukaryotic initiation factor-2α (P-eIf2α), activating transcription factor 6 (ATF6), phospho-inositol-requiring enzyme1 (P-IRE1α), and the EMT makers: fibronectin, vimentin, alpha-smooth muscle actin (α-SMA), and N-cadherin. Additionally, wound-healing assays were performed to evaluate the cell migration ability. Under HG, the morphology of HLECs became elongated, accompanied by a significantly increased cellular aspect ratio. Both the expression of ER stress markers (GRP78, P-eIF2α, ATF6, and P-IRE1α) and the EMT markers (fibronectin, vimentin, αSMA, and N-cadherin) increased. Conversely, the expression of E-cadherin, a marker of epithelial cells, decreased, and wound-healing assays indicated enhanced cell migration ability. All of these alterations were inhibited by PBA or TUDCA treatment. ER stress regulates HG-induced EMT in lens epithelial cells.
糖尿病患者已被证实发生囊下白内障的几率更高，且囊下白内障的形成与上皮-间充质转化（EMT）密切相关。内质网应激反应（ER应激）可调节众多组织中的EMT。在本研究中，我们旨在探讨ER应激在高糖（HG）诱导的人晶状体上皮细胞（HLECs）EMT中的作用。人晶状体上皮细胞系SRA01/04在HG条件下进行处理，使用4-苯基丁酸（PBA）或牛磺熊去氧胆酸（TUDCA）处理24小时，以在HG条件下恢复内质网（ER）稳态。使用ImageJ软件分析细胞的长轴和纵横比，以评估细胞形态。采用蛋白质免疫印迹分析和免疫荧光染色来检测ER应激标志物：葡萄糖调节蛋白78（GRP78）、真核起始因子2α的磷酸化（P-eIf2α）、活化转录因子6（ATF6）、磷酸化肌醇需求酶1（P-IRE1α），以及EMT标志物：纤连蛋白、波形蛋白、α-平滑肌肌动蛋白（α-SMA）和N-钙黏蛋白。此外，进行划痕试验以评估细胞迁移能力。在HG条件下，HLECs的形态变得细长，同时细胞纵横比显著增加。ER应激标志物（GRP78、P-eIF2α、ATF6和P-IRE1α）以及EMT标志物（纤连蛋白、波形蛋白、α-SMA和N-钙黏蛋白）的表达均增加。相反，上皮细胞标志物E-钙黏蛋白的表达降低，划痕试验表明细胞迁移能力增强。PBA或TUDCA处理可抑制所有这些改变。ER应激调节HG诱导的晶状体上皮细胞EMT。
