Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, Jiangsu Province, China.
Int Ophthalmol. 2023 Apr;43(4):1261-1274. doi: 10.1007/s10792-022-02524-x. Epub 2022 Sep 29.
To explore the regulatory effect of miR-125a-3p on lens epithelial cells (LECs) under ultraviolet radiation B (UVB) irradiation.
The expression of miR-125a-3p in age-related cataract (ARC) specimens and cell models was detected by qRT-PCR. UVB was utilized to establish DNA damage model of LECs. Cell count kit-8 was applied in detecting cell viability. Cell apoptosis ratio was analyzed by flow cytometry. Dual luciferase reports were applied to analyze the mechanism between miRNA and target genes. Nanoparticle tracking analysis, and Western blot were used to identify whether the exosomes were typical exosomes.
miR-125a-3p was upregulated in ARC tissues and LECs treated with UVB. Knockdown of miR-125a-3p in LECs significantly decreased apoptosis and increased viability of UVB-irradiated LECs. We predicted that miR-125a-3p could regulate transmembrane Bax inhibitor motif containing 4 (TMBIM4) by the bioinformatics databases TargetScan, miRBase, and miRWalk. Luciferase reporter assays demonstrated that miR-125a-3p may suppress TMBIM4 protein translation by binding to 3'UTR of TMBIM4 mRNA. Overexpression of miR-125a-3p decreased TMBIM4, which suggested that miR-125a-3p could inhibit TMBIM4. Moreover, knockdown of TMBIM4 decreased cell viability and enhanced cell apoptosis during UVB irradiation. In addition, the exosome secretion of LECs irradiated by UVB was enhanced, and the expression of miR-125a-3p was high. Cell viability was significantly decreased, and cell apoptosis was increased during UVB-exos treatment.
This study indicated that miR-125a-3p regulated apoptosis by suppressing TMBIM4 in LECs under oxidative damage, providing a new idea for clinical therapeutic target of cataract.
探讨 miR-125a-3p 在紫外线 B（UVB）照射下对晶状体上皮细胞（LEC）的调控作用。
采用 qRT-PCR 检测年龄相关性白内障（ARC）标本和细胞模型中 miR-125a-3p 的表达。利用 UVB 建立 LEC 细胞 DNA 损伤模型。采用细胞计数试剂盒-8 检测细胞活力。通过流式细胞术分析细胞凋亡率。采用双荧光素酶报告分析 miRNA 与靶基因之间的机制。采用纳米颗粒跟踪分析和 Western blot 鉴定外泌体是否为典型外泌体。
miR-125a-3p 在 ARC 组织和 UVB 处理的 LEC 中上调。LEC 中 miR-125a-3p 的敲低显著降低了 UVB 照射的 LEC 细胞的凋亡并增加了其活力。我们通过生物信息学数据库 TargetScan、miRBase 和 miRWalk 预测 miR-125a-3p 可能通过调节跨膜 Bax 抑制剂模体包含蛋白 4（TMBIM4）。荧光素酶报告实验表明，miR-125a-3p 可能通过与 TMBIM4 mRNA 的 3'UTR 结合来抑制 TMBIM4 蛋白的翻译。miR-125a-3p 的过表达降低了 TMBIM4，表明 miR-125a-3p 可以抑制 TMBIM4。此外，在 UVB 照射下，TMBIM4 的敲低降低了细胞活力并增强了细胞凋亡。此外，UVB 照射的 LEC 细胞外泌体分泌增加，miR-125a-3p 表达水平升高。UVB-exos 处理后细胞活力显著降低，细胞凋亡增加。
本研究表明，miR-125a-3p 通过抑制氧化损伤下 LEC 中的 TMBIM4 调节细胞凋亡，为白内障的临床治疗靶点提供了新的思路。
