Eye Center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, PR China; Hunan Key Laboratory of Ophthalmology, Changsha 410008, Hunan Province, PR China.
Eye Center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, PR China; Hunan Key Laboratory of Ophthalmology, Changsha 410008, Hunan Province, PR China.
Life Sci. 2020 Sep 1;256:117888. doi: 10.1016/j.lfs.2020.117888. Epub 2020 Jun 1.
The dysregulation of circular RNAs (circRNAs) has been implicated in the progression of diabetic retinopathy (DR). This study aims to explore the role and underlying mechanism of hsa_circ_0081108 (circCOL1A2) in DR.
circCOL1A2, vascular endothelial growth factor (VEGF) and miR-29b expression levels in human retinal microvascular endothelial cells (hRMECs) were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting. The biological functions of hRMECs were evaluated by MTT, transwell, tube formation, and vascular permeability assays, respectively. The interaction between miR-29b and circCOL1A2/VEGF was determined by dual luciferase assay. The release of VEGF was examined by ELISA. The in vivo role of circCOL1A2 was further verified in streptozotocin (STZ)-induced DR in mice. The pathological changes and VEGF expression in retinal tissues were detected by hematoxylin and eosin (HE) and immunohistochemical staining.
High glucose (HG) challenge led to increased circCOL1A2, VEGF, MMP-2, MMP-9 levels, but decreased miR-29b level in hRMECs. In addition, circCOL1A2 sponged miR-29b to promote VEGF expression. Silencing of circCOL1A2 inhibited HG-induced proliferation, migration, angiogenesis and vascular permeability of hRMECs via enhancing miR-29b expression. Moreover, circCOL1A2/miR-29b axis participated in HG-induced increase in angiogenesis-related protein expression. Finally, circCOL1A2 knockdown suppressed angiogenesis via regulating miR-29b/VEGF axis in DR mice.
circCOL1A2 facilities angiogenesis during the pathological progression of DR via regulating miR-29b/VEGF axis, suggesting that targeting circCOL1A2 may be a potential treatment for DR.
环状 RNA（circRNA）的失调与糖尿病视网膜病变（DR）的进展有关。本研究旨在探讨 hsa_circ_0081108（circCOL1A2）在 DR 中的作用及其潜在机制。
采用实时定量逆转录聚合酶链反应（RT-qPCR）和 Western blot 检测人视网膜微血管内皮细胞（hRMEC）中 circCOL1A2、血管内皮生长因子（VEGF）和 miR-29b 的表达水平。分别通过 MTT、Transwell、管形成和血管通透性测定评估 hRMEC 的生物学功能。通过双荧光素酶报告基因测定确定 miR-29b 与 circCOL1A2/VEGF 之间的相互作用。通过 ELISA 检测 VEGF 的释放。进一步通过链脲佐菌素（STZ）诱导的 DR 小鼠模型验证 circCOL1A2 的体内作用。通过苏木精和伊红（HE）和免疫组织化学染色检测视网膜组织的病理变化和 VEGF 表达。
高糖（HG）刺激导致 hRMEC 中 circCOL1A2、VEGF、MMP-2 和 MMP-9 水平升高，但 miR-29b 水平降低。此外，circCOL1A2 可通过海绵吸附 miR-29b 促进 VEGF 表达。沉默 circCOL1A2 通过增强 miR-29b 表达抑制 HG 诱导的 hRMEC 增殖、迁移、血管生成和血管通透性。此外，circCOL1A2/miR-29b 轴参与了 HG 诱导的血管生成相关蛋白表达增加。最后，circCOL1A2 敲低通过调节 miR-29b/VEGF 轴抑制 DR 小鼠的血管生成。
circCOL1A2 通过调节 miR-29b/VEGF 轴促进 DR 病理进展过程中的血管生成，表明靶向 circCOL1A2 可能是 DR 的一种潜在治疗方法。
