Cutaneous and Ocular Toxicology ( IF 1.6 ) Pub Date : 2021-08-06 , DOI: 10.1080/15569527.2021.1879112 Qiuxin Wu 1, 2 , Zhongen Li 1, 2 , Xiuzhen Lu 2 , Jike Song 1, 2 , Hui Wang 1, 2 , Dongmei Liu 2 , Dadong Guo 3 , Hongsheng Bi 2, 3
Abstract
Objective
Oxidative stress has been recognised as an important mediator of apoptosis in lens epithelial cells. It also plays an important role in the pathogenesis of cataracts. It is reported that (-)-Epigallocatechin gallate (EGCG), the most abundant component in green tea, exhibits potent antioxidant activity against oxidative stress. This study aimed to investigate the protective effect of EGCG against Ultraviolet B (UVB) induced apoptotic death and the underlying mechanism in human lens epithelial cells (HLECs).
Methods
HLECs were exposed to various concentrations of EGCG under UVB (30 mJ/cm2), and cell viability was monitored by the MTT assay. Next, mitochondrial membrane potential (Δψm), reactive oxygen species (ROS) and apoptosis were detected by flow cytometry. Meanwhile, the total antioxigenic capacity (T-AOC) was determined by enzyme standard instrument, and the expression of apoptosis inducing factor (AIF) and endonuclease G (Endo G) was measured by quantitative PCR (Q-PCR) and western blotting, respectively. Moreover, the localisation of AIF and Endo G within cells was further detected by confocal optical microscopy.
Results
The results indicated that EGCG could enhance the cell viability and protect against cell apoptosis caused by UVB irradiation in HLECs. EGCG could also decrease the UVB-induced generation of ROS and collapse of Δψm, increase the T-AOC level. In addition, EGCG could also inhibit the UVB-stimulated increase of AIF and Endo G expression at mRNA and protein levels and ameliorate the UVB-induced mitochondria-nuclear translocation of AIF and Endo G.
Conclusions
UVB irradiation could damage HLECs viability, while EGCG exhibits antioxidant effect and inhibits UVB-induced apoptosis in HLECs through AIF/Endo G signalling pathways. Our findings reveal the underlying mechanism of EGCG against UVB-induced oxidative stress in HLECs.
中文翻译:
表没食子儿茶素没食子酸酯通过体外 AIF/endo G 信号通路保护人晶状体上皮细胞免受 UVB 照射
摘要
客观的
氧化应激已被认为是晶状体上皮细胞凋亡的重要介质。它还在白内障的发病机制中起重要作用。据报道,绿茶中最丰富的成分 (-)-Epigallocatechin gallate (EGCG) 对氧化应激表现出有效的抗氧化活性。本研究旨在探讨 EGCG 对紫外线 B (UVB) 诱导的人晶状体上皮细胞 (HLECs) 凋亡的保护作用及其潜在机制。
方法
HLECs 在 UVB (30 mJ/cm 2 ) 下暴露于不同浓度的 EGCG,并通过 MTT 测定监测细胞活力。接下来,通过流式细胞术检测线粒体膜电位(Δψm)、活性氧(ROS)和细胞凋亡。同时,酶标仪测定总抗氧化能力(T-AOC),定量PCR(Q-PCR)和western blotting分别测定凋亡诱导因子(AIF)和核酸内切酶G(Endo G)的表达。 . 此外,通过共聚焦光学显微镜进一步检测了 AIF 和 Endo G 在细胞内的定位。
结果
结果表明,EGCG可以增强HLECs中的细胞活力并防止UVB照射引起的细胞凋亡。EGCG 还可以减少 UVB 诱导的 ROS 的产生和 Δψm 的崩溃,增加 T-AOC 水平。此外,EGCG 还可以抑制 UVB 刺激的 AIF 和 Endo G 在 mRNA 和蛋白质水平表达的增加,并改善 UVB 诱导的 AIF 和 Endo G 的线粒体 - 核易位。
结论
UVB照射会损害HLECs的活力,而EGCG具有抗氧化作用,并通过AIF/Endo G信号通路抑制UVB诱导的HLECs凋亡。我们的研究结果揭示了 EGCG 在 HLECs 中对抗 UVB 诱导的氧化应激的潜在机制。