Ling Jiaojiao, Tan Ke, Lu Lu, Yang Fang, Luan Lan
Department of Ophthalmology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China.
Exp Ther Med. 2020 Aug;20(2):1053-1063. doi: 10.3892/etm.2020.8749. Epub 2020 May 13.
Age-related cataract (ARC) is a common cause of blindness in elderly individuals. Long non-coding RNA (lncRNA) myocardial infarction associated transcript (MIAT) has been reported to participate in various biological processes in a number of diseases; however, the biological mechanism underlying MIAT during ARC is not completely understood. The expression levels of MIAT, microRNA (miR)-181a and connective tissue growth factor (CTGF) were measured by reverse transcription-quantitative PCR. The protein expression levels of CTGF, α-smooth muscle actin, fibronectin, collagen type I, ERK, phosphorylated (p)-ERK, mitogen-activated protein kinase (MEK), and p-MEK were detected by western blotting. Cell viability and migration were assessed using MTT and Transwell assays, respectively. Moreover, a dual-luciferase reporter assay was performed to investigate the interaction between miR-181a and MIAT or CTGF. MIAT and CTGF were upregulated, while miR-181a was significantly downregulated in ARC tissues compared with normal tissues. MIAT or CTGF knockdown decreased cell viability, migration, epithelial-mesenchymal transition and extracellular matrix production in TGF-β2-treated SRA01/04 cells. It was hypothesized that miR-181a may be sponged by MIAT and may target CTGF. Furthermore, the miR-181a inhibitor reversed the inhibitory effect of MIAT knockdown on the progression of TGF-β2-treated SRA01/04 cells. Moreover, CTGF knockdown also reversed MIAT overexpression-mediated progression of TGF-β2-treated SRA01/04 cells. In addition, MIAT and CTGF regulated the activity of the ERK signaling pathway. The results suggested that MIAT may regulate the progression of ARC via the miR-181a/CTGF/ERK signaling pathway, which may serve as a novel therapeutic target for ARC.
年龄相关性白内障（ARC）是老年人失明的常见原因。据报道，长链非编码RNA（lncRNA）心肌梗死相关转录本（MIAT）参与多种疾病的各种生物学过程；然而，ARC发生过程中MIAT的生物学机制尚未完全明确。采用逆转录-定量PCR检测MIAT、微小RNA（miR）-181a和结缔组织生长因子（CTGF）的表达水平。通过蛋白质印迹法检测CTGF、α-平滑肌肌动蛋白、纤连蛋白、I型胶原、细胞外信号调节激酶（ERK）、磷酸化（p）-ERK、丝裂原活化蛋白激酶（MEK）和p-MEK的蛋白表达水平。分别采用MTT法和Transwell实验评估细胞活力和迁移能力。此外，进行双荧光素酶报告基因实验以研究miR-181a与MIAT或CTGF之间的相互作用。与正常组织相比，ARC组织中MIAT和CTGF上调，而miR-181a显著下调。敲低MIAT或CTGF可降低经转化生长因子-β2（TGF-β2）处理的SRA01/04细胞的活力、迁移能力、上皮-间质转化和细胞外基质生成。研究推测miR-181a可能被MIAT吸附，并可能靶向CTGF。此外，miR-181a抑制剂可逆转敲低MIAT对经TGF-β2处理的SRA01/04细胞进展的抑制作用。此外，敲低CTGF也可逆转MIAT过表达介导的经TGF-β2处理的SRA01/04细胞的进展。此外，MIAT和CTGF调节ERK信号通路的活性。结果表明，MIAT可能通过miR-181a/CTGF/ERK信号通路调节ARC的进展，这可能成为ARC的一个新的治疗靶点。
