ABSTRACT

MiR-34a is associated with diabetic retinopathy (DR). This article aims to demystify the role of miR-34a in DR. We established a DR model by streptozocin injection. Rat retinal vascular endothelial cells (RVECs) were treated with high glucose (HG) to induce DR. The pathological changes of retinal tissues and blood-retinal vascular barrier permeability of DR rats were assessed by HE staining and Evans-Blue leak test. The expression of gene and protein was evaluated by quantitative real-time PCR or western blot. MTT assay and flow cytometry were performed to detect proliferation and apoptosis. The relationship between miR-34a and SIRT1 was evaluated using luciferase reporter assay. MiR-34a was up-regulated and SIRT1 was down-regulated in retinal tissues of DR rats and HG-induced RVECs. MiR-34a silencing improved DR by regulating apoptosis and VEGF expression in DR rats. Furthermore, miR-34a interacted with SIRT1 and suppressed SIRT1 expression. MiR-34a overexpression inhibited proliferation and promoted apoptosis of RVECs, which was effectively abolished by SIRT1 up-regulation. In summary, our data demonstrate that miR-34a promotes apoptosis of RVECs by targeting SIRT1 in DR rats. Our findings suggest that miR-34a/SIRT1 axis could be a valuable target for DR therapies.

摘要

MiR-34a 与糖尿病视网膜病变 (DR) 相关。本文旨在揭开 miR-34a 在 DR 中的作用的神秘面纱。我们通过链脲佐菌素注射建立了DR模型。用高糖 (HG) 处理大鼠视网膜血管内皮细胞 (RVEC) 以诱导 DR。采用HE染色和Evans-Blue渗漏试验评估DR大鼠视网膜组织病理变化和血-视网膜血管屏障通透性。通过定量实时PCR或蛋白质印迹评估基因和蛋白质的表达。进行MTT测定和流式细胞术以检测增殖和凋亡。使用荧光素酶报告基因测定评估 miR-34a 和 SIRT1 之间的关系。在 DR 大鼠和 HG 诱导的 RVECs 的视网膜组织中，miR-34a 上调而 SIRT1 下调。MiR-34a 沉默通过调节 DR 大鼠的细胞凋亡和 VEGF 表达来改善 DR。此外，miR-34a 与 SIRT1 相互作用并抑制 SIRT1 表达。MiR-34a 过表达抑制了 RVECs 的增殖并促进了其凋亡，而 SIRT1 上调可有效消除这种情况。总之，我们的数据表明 miR-34a 通过靶向 DR 大鼠的 SIRT1 促进 RVEC 的凋亡。我们的研究结果表明 miR-34a/SIRT1 轴可能是 DR 治疗的一个有价值的目标。