1 Department of Ocular Pharmacology, Dr. G. Venkataswamy Eye Research Institute , Madurai, India .
2 Department of Immunology & Stem Cell Biology, Dr. G. Venkataswamy Eye Research Institute , Madurai, India .
J Ocul Pharmacol Ther. 2017 Jan/Feb;33(1):34-41. doi: 10.1089/jop.2016.0103. Epub 2016 Nov 11.
Aldose reductase (ALR), the first and rate-limiting enzyme involved in polyol pathway plays a central role in diabetes and its related complications, including diabetic retinopathy (DR). Inhibition of ALR may also be an ideal target for reducing the deleterious effects of DR. Therefore, the purpose of the present study was to investigate the protective effect of epalrestat (EPL), ALR inhibitor on glucose-induced toxicity in ARPE-19 cells.
ARPE-19 cells were challenged with normal glucose (NG, 5 mM) and high glucose (HG1, 25 mM and HG2, 50 mM) in the presence or absence of EPL. ALR and VEGF expression in retinal pigment epithelial (RPE) cells under experimental conditions were quantified by real-time polymerase chain reaction using SYBR Green chemistry. Vascular endothelial growth factor (VEGF) secretion in the cell supernatant was measured by Sandwich ELISA. Cytotoxicity of EPL was assessed by MTT assay. ALR inhibitory activity, apoptosis, and sorbitol accumulation were also investigated.
EPL at studied concentration did not show any toxicity to RPE cells and showed as maximum as 65% ALR inhibition under high glucose condition (HG1). The presence of EPL significantly reduced ALR expression and VEGF levels as induced by high glucose in ARPE-19 cells.
Inhibition of ALR appeared to be beneficial in reducing diabetes-related complications in RPE cells under high glucose condition.
醛糖还原酶(ALR)是多元醇途径中涉及的第一个限速酶,在糖尿病及其相关并发症中发挥核心作用,包括糖尿病视网膜病变(DR)。抑制 ALR 也可能是减少 DR 有害影响的理想靶点。因此,本研究的目的是探讨醛糖还原酶抑制剂依帕司他(EPL)对 ARPE-19 细胞中葡萄糖诱导毒性的保护作用。
在存在或不存在 EPL 的情况下,用正常葡萄糖(NG,5 mM)和高葡萄糖(HG1,25 mM 和 HG2,50 mM)处理 ARPE-19 细胞。用 SYBR Green 化学法通过实时聚合酶链反应定量检测实验条件下视网膜色素上皮(RPE)细胞中的 ALR 和血管内皮生长因子(VEGF)表达。通过 Sandwich ELISA 测量细胞上清液中 VEGF 的分泌。通过 MTT 测定法评估 EPL 的细胞毒性。还研究了 ALR 抑制活性、细胞凋亡和山梨醇积累。
在研究浓度下,EPL 对 RPE 细胞没有任何毒性,并且在高葡萄糖条件下(HG1)对 ALR 的抑制率高达 65%。EPL 的存在显著降低了 ARPE-19 细胞中高葡萄糖诱导的 ALR 表达和 VEGF 水平。
在高葡萄糖条件下,抑制 ALR 似乎有利于减少 RPE 细胞与糖尿病相关的并发症。