LncRNA H19 deficiency protects against the structural damage of glomerular endothelium in diabetic nephropathy via Akt/eNOS pathway

<b>Objective:</b> This study aimed to investigate the functions of lncRNA H19 on glomerular endothelial structural damage of diabetic nephropathy (DN). <b>Materials and Methods:</b> Rats were fed a high sugar and fat high feed die, and intraperitoneally administrated with streptozotocin (30 mg/kg) to induce DN model. Meanwile, rat glomerular endothelial cells (rGEnCs) were treated with high a level of glucose （HG, 30 mM glucose）to induce structural damage. <b>Results:</b> Our results showed that H19 level was drastically increased in diabetic glomeruli and high-glucose (HG)-stimulated rat glomerular endothelial cells (rGEnCs). Deficiency of H19 ameliorated microalbumin, creatinine, BUN, and histopathological alterations in diabetic rats. In addition, H19 deficiency significantly attenuated the damage of endothelial structure by upregulating the expression of junction proteins ZO-1 and Occludin, glycolcalyx protein Syndecan-1, and endothelial activation marker sVCAM-1 and sICAM-1 in diabetic rats. The <i>in vitro</i> results also showed that H19-siRNA alleviated glycocalyx shedding, tight junctions damage, and endothelial activation in HG-stimulated rGEnCs. Moreover, H19 deficiency significantly enhanced the expression of p-Akt and p-eNOS and NO concentration <i>in vitro</i> and <i>in vivo</i>. Pre-treatment with Akt inhibitor LY294002 abrogated these favourable effects mediated by H19 deficiency. <b>Discussion and Conclusion:</b> These results indicate that H19 deficiency could mitigate the structural damage of glomerular endothelium in DN via activating Akt/eNOS pathway.**研究目的：** 本研究旨在探讨长链非编码RNA H19（lncRNA H19）对糖尿病肾病（diabetic nephropathy, DN）肾小球内皮结构损伤的影响。 **材料与方法：** 采用高糖高脂饲料喂养大鼠，并通过腹腔注射链脲佐菌素（streptozotocin, 30 mg/kg）构建糖尿病肾病模型。与此同时，将大鼠肾小球内皮细胞（rat glomerular endothelial cells, rGEnCs）置于高糖环境（high glucose, HG，30 mM葡萄糖）中培养，以诱导其结构损伤。 **结果：** 本研究结果显示，糖尿病大鼠肾小球及高糖刺激的大鼠肾小球内皮细胞（rGEnCs）中H19的表达水平显著升高。敲低H19可改善糖尿病大鼠的微量白蛋白尿、肌酐、尿素氮（blood urea nitrogen, BUN）水平及肾脏组织病理学改变。此外，在糖尿病大鼠体内，敲低H19可通过上调紧密连接蛋白ZO-1、Occludin、糖萼蛋白Syndecan-1以及内皮激活标志物sVCAM-1、sICAM-1的表达，显著减轻内皮结构损伤。体外（in vitro）实验结果同样表明，H19小干扰RNA（H19-siRNA）可缓解高糖刺激的rGEnCs的糖萼脱落、紧密连接损伤及内皮激活现象。进一步研究发现，敲低H19可在体内（in vivo）外显著增强p-Akt、p-eNOS的表达及一氧化氮（nitric oxide, NO）的浓度。使用Akt抑制剂LY294002进行预处理后，可抵消敲低H19所介导的上述有益效应。 **讨论与结论：** 上述结果表明，敲低H19可通过激活Akt/eNOS通路，减轻糖尿病肾病中肾小球内皮的结构损伤。