Eye Center, The Second Hospital of Jilin University, #218 Ziqiang Street, 130021, Changchun, Jilin, China.
Department of Ophthalmology, Shanghai General Hospital, #100 Haining Road, 200080, Shanghai, China.
Endocrine. 2019 Jul;65(1):35-45. doi: 10.1007/s12020-019-01921-0. Epub 2019 Apr 12.
Vascular endothelial growth factor (VEGF) plays implicated roles in diabetic retinopathy (DR). The role of roundabout 4 (Robo 4) in angiogenesis and vasculogenesis is controversial; however, the interdependent relationship between these two factors has not been studied in DR. This study determined the colocalization of VEGF and Robo4 in fibrovascular membranes (FVM) from patients with proliferative diabetic retinopathy (PDR). MicroRNA (miRNA)-mediated modulation of VEGF and Robo4 was explored in diabetic rats and ARPE-19 tissue culture cells under hyperglycemia.
VEGF and Robo4 co-expression in the FVM was analyzed using immunofluorescence. VEGF and Robo4 levels were determined in diabetic retinas and ARPE-19 tissue culture cells under high glucose using western blotting and RT-qPCR. MicroRNA agomir was intraocularly injected to increase miR-15a expression and downregulate VEGF and Robo4 levels in diabetic retinas.
VEGF and Robo4 colocalization in FVM vessels was observed. Increased VEGF levels were consistent in diabetic retinas and ARPE-19 tissue culture cells cultured under hyperglycemia. Robo4 decreased in ARPE-19 tissue culture cells exposed to hyperglycemia for 72 h, whereas it increased in diabetic rat retinas. Several miRNAs were differentially expressed during DR progression. Furthermore, miR-15a agomir injection inhibited high levels of VEGF and Robo4 in diabetic retinas.
VEGF and Robo4 were co-expressed in FVMs from PDR patients. In the early stages of DR, VEGF was upregulated and contributed to DR development, whereas, in the late stage of DR, VEGF and Robo4 worked together to aggravate DR progression. However, miR-15a could downregulate VEGF and Robo4 to ameliorate DR development.
血管内皮生长因子（VEGF）在糖尿病视网膜病变（DR）中起重要作用。Roundabout 4（Robo4）在血管生成和血管发生中的作用存在争议；然而，这两个因素之间的相互依赖关系在 DR 中尚未得到研究。本研究旨在确定增生性糖尿病视网膜病变（PDR）患者的纤维血管膜（FVM）中 VEGF 和 Robo4 的共定位。在高血糖条件下，利用糖尿病大鼠和 ARPE-19 组织培养细胞探索 microRNA（miRNA）对 VEGF 和 Robo4 的调节作用。
采用免疫荧光法分析 FVM 中 VEGF 和 Robo4 的共表达。采用 Western blot 和 RT-qPCR 测定高糖条件下糖尿病视网膜和 ARPE-19 组织培养细胞中的 VEGF 和 Robo4 水平。通过眼内注射 miRNA 激动剂增加 miR-15a 的表达，下调糖尿病视网膜中 VEGF 和 Robo4 的水平。
在 FVM 血管中观察到 VEGF 和 Robo4 的共定位。高血糖条件下，糖尿病视网膜和 ARPE-19 组织培养细胞中 VEGF 水平均升高。高糖作用 72 小时后，ARPE-19 组织培养细胞中 Robo4 减少，而糖尿病大鼠视网膜中 Robo4 增加。DR 进展过程中，几种 miRNA 表达差异。此外，miR-15a 激动剂注射抑制糖尿病视网膜中高水平的 VEGF 和 Robo4。
PDR 患者的 FVM 中 VEGF 和 Robo4 共表达。在 DR 的早期阶段，VEGF 上调并促进 DR 的发展，而在 DR 的晚期阶段，VEGF 和 Robo4 共同作用加剧 DR 的进展。然而，miR-15a 可下调 VEGF 和 Robo4 以改善 DR 的发展。
