Long Noncoding RNA OIP5-AS1 Promotes Cell Apoptosis and Cataract Formation by Blocking POLG Expression Under Oxidative Stress

作者：Ruihua Jing, Bo Ma, Tiantian Qi, Conghui Hu, Chongbing Liao, Chan Wen, Yongping Shao, Cheng Pei · 发表于：Investigative Ophthalmology & Visual Science · 年份：2020 · DOI：10.1167/iovs.61.12.3 · 被引用次数：25 · 研究领域：Connexins and lens biology、Cancer-related molecular mechanisms research、Circular RNAs in diseases

Purpose: Cataract, a clouding of the intraocular lens, is the leading cause of blindness. The lens-expressed long noncoding RNA OIP5-AS1 was upregulated in lens epithelial cells from patients with cataracts, suggesting its pathogenic role in cataracts. We investigated the regulatory role of OIP5-AS1 in the development of cataracts as well as potential RNA binding proteins, downstream target genes, and upstream transcription factors. Methods: Clinical capsules and ex vivo and in vitro cataract models were used to test OIP5-AS1 expression. Cell apoptosis was detected using Western blots, JC-1 staining, and flow cytometry. Ribonucleoprotein immunoprecipitation-qPCR was performed to confirm the interaction of OIP5-AS1 and POLG. Chromatin immunoprecipitation-qPCR was used to determine the binding of TFAP2A and the OIP5-AS1 promoter region. Results: OIP5-AS1 was upregulated in cataract lenses and B3 cells under oxidative stress. OIP5-AS1 knockdown protected B3 cells from H2O2-induced apoptosis and alleviated lens opacity in the ex vivo cataract model. HuR functioned as a scaffold carrying OIP5-AS1 and POLG mRNA and mediated the decay of POLG mRNA. POLG was downregulated in the cataract lens and oxidative-stressed B3 cells, and POLG depletion decreased the mtDNA copy number and MMP, increased reactive oxygen species production, and sensitized B3 cells to oxidative stress-induced apoptosis. POLG overexpression reversed these effects. TFAP2A bound the OIP5-AS1 promoter and contributed...