Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Exp Eye Res. 2021 Jun;207:108572. doi: 10.1016/j.exer.2021.108572. Epub 2021 Apr 15.
Posterior capsular opacification (PCO) is the major vision-disrupting complication arising after cataract surgery. Circular RNAs (circRNAs) are biological active RNAs which were involved in various physiological functions. So far, the role of circRNA caspase recruitment domain family member 6 (circ-CARD6) in PCO is still unclear.
Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of circ-CARD6, microRNA 31 (miR-31) and fibroblast growth factor 7 (FGF7) message RNA (mRNA). Western blot was used to analyze the protein expression. Transmission electron microscopy (TEM) was employed to capture the exosome image. The proliferation and metastasis were analyzed by cell counting kit-8 (CCK8), transwell and wound healing assays. The potential binding sequences between miR-31 and circ-CARD6 or FGF7 were respectively predicted by Circinteractome and Targetscan online tool, and verified by dual-luciferase reporter and RNA binding protein immunoprecipitation (RIP) assays.
Exosome-transmitted circ-CARD6 was highly expressed in PCO tissues and TGF-β2-treated SRA01/04 cells. Circ-CARD6 deletion repressed the proliferation, metastasis, EMT process and MAPK pathway, which was reversed by anti-miR-31 in TGF-β2-treated SRA01/04 cells. Meanwhile, circ-CARD6 sponged miR-31 which directly targeted FGF7 in TGF-β2-treated SRA01/04 cells. FGF7 overexpression allayed miR-31 overexpression-induced suppression in proliferation, metastasis, EMT process and MAPK pathway. Besides, circ-CARD6 regulated FGF7 expression by sponging miR-31.
Circ-CARD6 promoted PCO development via miR-31/FGF7 axis. This finding might contribute to the development of the targeted therapy for PCO.
后囊膜混浊（PCO）是白内障手术后导致视力障碍的主要并发症。环状 RNA（circRNA）是参与多种生理功能的生物活性 RNA。迄今为止，circRNA 半胱氨酸天冬氨酸蛋白酶募集域家族成员 6（circ-CARD6）在 PCO 中的作用尚不清楚。
采用实时定量聚合酶链反应（qRT-PCR）检测 circ-CARD6、microRNA 31（miR-31）和成纤维细胞生长因子 7（FGF7）mRNA 的表达。Western blot 用于分析蛋白表达。透射电子显微镜（TEM）用于捕获外泌体图像。细胞计数试剂盒-8（CCK8）、Transwell 和划痕愈合实验分析细胞增殖和转移。Circinteractome 和 Targetscan 在线工具分别预测 miR-31 和 circ-CARD6 或 FGF7 之间的潜在结合序列，并通过双荧光素酶报告和 RNA 结合蛋白免疫沉淀（RIP）实验验证。
PCO 组织和 TGF-β2 处理的 SRA01/04 细胞中高度表达外泌体传递的 circ-CARD6。circ-CARD6 缺失抑制 TGF-β2 处理的 SRA01/04 细胞的增殖、转移、EMT 过程和 MAPK 通路，而在 TGF-β2 处理的 SRA01/04 细胞中抗 miR-31 可逆转这一作用。同时，circ-CARD6 可作为 miR-31 的海绵，直接靶向 TGF-β2 处理的 SRA01/04 细胞中的 FGF7。FGF7 过表达缓解了 miR-31 过表达引起的增殖、转移、EMT 过程和 MAPK 通路的抑制作用。此外，circ-CARD6 通过海绵吸附 miR-31 来调节 FGF7 的表达。
circ-CARD6 通过 miR-31/FGF7 轴促进 PCO 的发展。这一发现可能有助于开发针对 PCO 的靶向治疗。
