藤黄酸通过CYLD/NF-κB信号通路抑制高糖环境下RPE细胞上皮-间充质转化的作用

目的　基于去泛素化酶圆柱瘤蛋白/核因子κB（CYLD/NF-κB）通路，研究藤黄酸（GA）对高糖环境下视网膜色素上皮(RPE)细胞上皮-间充质转化(EMT)的作用。方法　体外培养ARPE-19 细胞，高糖诱导，实验分为NC组（含5.5 mmol·L^-1葡萄糖），HG组(含30 mmol·L^-1葡萄糖)，HG+不同剂量GA组(2 μmol·L^-1、4 μmol·L^-1、8 μmol·L^-1 GA分别预处理RPE细胞1 h，加30 mmol·L^-1葡萄糖)。CCK-8检测各组RPE细胞增殖活力，免疫荧光染色检测RPE细胞中α平滑肌肌动蛋白（α-SMA）、去泛素化酶圆柱瘤蛋白(CYLD)表达；Western blot检测RPE细胞中α-SMA、CYLD、磷酸化核转录因子κB（p-NF-κB）蛋白表达。结果　与NC组相比，HG组RPE细胞出现明显增殖，RPE细胞中α-SMA、p-NF-κB蛋白表达均增加，CYLD蛋白表达减少（均为P<0.01）；与HG组相比，HG+不同剂量GA组RPE细胞增殖均明显受到抑制，RPE细胞中α-SMA、p-NF-κB蛋白表达均减少，CYLD表达均增加（均为P<0.01），且均呈剂量依赖性。结论　GA可抑制高糖环境下RPE细胞EMT，其抑制作用与上调CYLD，抑制NF-κB活化有关。

Inhibition effect of gambogic acid on the epithelial-mesenchymal transition of retinal pigment epithelium cells via cylindromatosis/ nuclear factor-kappaB signaling pathway under high glucose circumstance

Objective　To study the effects of gambogic acid (GA) on the epithelial-mesenchymal transition (EMT) of retinal pigment epithelium (RPE) cells in high glucose environment via the deubiquitinating enzyme cylindromatosis/nuclear factor-kappaB (CYLD/NF-кB) signaling pathway. Methods　The adult retinal pigment epithelium-19 (ARPE-19) cells were cultured in vitro in a high-glucose medium. The normal control group (NC group, containing 5.5 mmol·L^-1 glucose), high glucose group (HG group, containing 30 mmol·L^-1 glucose), and HG + various doses of GA groups (the RPE cells were pre-treated with 2 μmol·L^-1 GA, 4 μmol·L^-1 GA or 8 μmol·L^-1 GA for 1 h, and then added with 30 mmol·L^-1 glucose) were set. The proliferation and viability of RPE cells in all groups were evaluated by Cell Counting Kit-8, the expression levels of α-smooth-muscle-actin (α-SMA) and CYLD were detected by immunofluorescence staining, and the expression levels of α-SMA, CYLD, and phosphorylation nuclear factor-kappaB (p-NF-κB) were measured by Western-blot. Results　Compared with the NC group, in the HG group, the RPE cells proliferated significantly, the expressions of α-SMA and p-NF-κB were up-regulated, and the CYLD protein expression was decreased (all P<0.01). Under the various doses of GA intervention, the proliferation of RPE cells was significantly inhibited, the expressions of α-SMA and p-NF-κB decreased, and the CYLD expression increased (all P<0.01) in a dose-dependent manner as compared to the HG group. Conclusion　Under high glucose circumstances, GA can inhibit the EMT of RPE cells by inducing CYLD expression and attenuating NF-кB activation.