Early diagnosis and precise monitoring of the development of proliferative diabetic retinopathy (PDR) can significantly improve therapeutic strategies and help decrease blindness caused by it. Extracellular vesicles (EVs) were recently found to be involved in intercellular communications and are a potential source for the discovery of novel biomarkers. The current study aims to investigate the effectiveness of microRNAs (miRNAs) encapsulated in small EVs (sEVs) as minimally invasive biomarkers for PDR. SEVs were extracted from plasma of healthy subjects, diabetic patients, nonPDR patients and PDR patients. Then, we performed microarray analysis to determine the miRNA expression profile. MiR-431-5p expression doubled in the PDR patients compared with the healthy controls and the diabetic patients. We further found that miR-431-5p expression was 2.3 times higher in 4-hydroxynonenal treated human retinal capillary endothelial cells (HRCECs) than the control. After transfection with miR-431-5p mimics, proliferation of HRCECs was promoted, while transfection with miR-431-5p inhibitor demonstrated the opposite effect. The present findings indicate that circulating sEVs showed a differential miRNA profile in PDR patients. MiR-431-5p was involved in the pathogenesis of PDR development and may function as a novel biomarker for PDR.

早期诊断和精确监测增殖性糖尿病视网膜病变 (PDR) 的发展可以显着改善治疗策略并有助于减少由此引起的失明。最近发现细胞外囊泡 (EV) 参与细胞间通讯，并且是发现新生物标志物的潜在来源。目前的研究旨在研究封装在小 EVs (sEVs) 中的 microRNAs (miRNAs) 作为 PDR 微创生物标志物的有效性。从健康受试者、糖尿病患者、非 PDR 患者和 PDR 患者的血浆中提取 SEV。然后，我们进行了微阵列分析以确定 miRNA 表达谱。与健康对照和糖尿病患者相比，PDR 患者的 MiR-431-5p 表达增加了一倍。我们进一步发现 miR-431-5p 表达为 2。4-羟基壬烯醛处理的人视网膜毛细血管内皮细胞 (HRCEC) 比对照高 3 倍。转染 miR-431-5p 模拟物后，HRCECs 的增殖得到促进，而转染 miR-431-5p 抑制剂则表现出相反的效果。目前的研究结果表明，循环 sEV 在 PDR 患者中显示出不同的 miRNA 谱。MiR-431-5p 参与 PDR 发展的发病机制，可能作为 PDR 的新型生物标志物。