BACKGROUND Aberrant endothelial function is a major contributing factor in cardiovascular disease. Dyslipidemia leads to decreased nitric oxide (NO) bioavailability, an early sign of endothelial failure. Low insulin gene enhancer protein (ISL1) levels decrease healthy NO bioavailability. We hypothesized that the microRNA miR-652-3p negatively regulates endothelial ISL1 expression and that dyslipidemia-induced miR-652-3p upregulation induces aberrant endothelial functioning via ISL1 downregulation. METHODS Various in vitro experiments were conducted in human umbilical vein endothelial cells (HUVECs). Luciferase assays were performed in HEK293 cells. We constructed a high-fat diet (HFD) Apoe-/- murine model of dyslipidemia and a rat model of low-density lipoprotein (LDL)-induced dyslipidemia to conduct in vivo and ex vivo experiments. RESULTS Luciferase assays confirmed miR-652-3p's targeting of the ISL1 3'-untranslated region (3'-UTR). Simvastatin blocked oxidized LDL (ox-LDL)-induced increases in miR-652-3p and ox-LDL-induced decreases in ISL1 protein expression, endothelial NO synthase (eNOS) activation, and NO production. Simvastatin's effects were abrogated by miR-652-3p overexpression and phenocopied by miR-652-3p inhibition. The dyslipidemic mouse model exhibited increased miR-652-3p and decreased ISL1 protein levels in the endothelium, effects opposed by simvastatin or miR-652-3p inhibition. The impact of simvastatin in vivo was abolished by overexpressing miR-652-3p or knocking-down ISL1. The rat model of dyslipidemia exhibited a similar pattern of miR-652-3p upregulation, attenuated ISL1 protein levels, decreased eNOS activation, and decreased NO production, effects mitigated by simvastatin. CONCLUSIONS Dyslipidemia upregulates endothelial miR-652-3p, which decreases ISL1 protein levels, eNOS activation, and NO production. Simvastatin therapy lowers endothelial miR-652-3p expression to protect endothelial function under dyslipidemic conditions.

中文翻译：

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他汀类下调的miR-652-3p通过促进ISL1表达来保护内皮免于血脂异常。

背景技术内皮功能异常是导致心血管疾病的主要因素。血脂异常会导致一氧化氮（NO）生物利用度降低，这是内皮功能衰竭的早期迹象。低胰岛素基因增强蛋白（ISL1）水平会降低健康NO的生物利用度。我们假设microRNA miR-652-3p负调节内皮ISL1的表达和血脂异常诱导的miR-652-3p上调通过ISL1下调诱导异常的内皮功能。方法在人脐静脉内皮细胞（HUVEC）中进行了各种体外实验。在HEK293细胞中进行萤光素酶测定。我们构建了血脂异常的高脂饮食（HFD）Apoe-/-鼠模型和低密度脂蛋白（LDL）诱导的血脂异常的大鼠模型，以进行体内和离体实验。结果荧光素酶测定法证实了miR-652-3p靶向ISL1 3'非翻译区（3'-UTR）。辛伐他汀阻止了氧化的LDL（ox-LDL）诱导的miR-652-3p的增加和ox-LDL诱导的ISL1蛋白表达，内皮一氧化氮合酶（eNOS）活化以及NO生成的减少。miR-652-3p的过表达消除了辛伐他汀的作用，miR-652-3p的抑制作用显着抑制了辛伐他汀的作用。血脂异常小鼠模型在内皮细胞中表现出增加的miR-652-3p和降低的ISL1蛋白水平，辛伐他汀或miR-652-3p抑制作用相反。过度表达miR-652-3p或敲除ISL1可消除辛伐他汀在体内的影响。血脂异常大鼠模型表现出类似的miR-652-3p上调模式，ISL1蛋白水平降低，eNOS激活降低，并减少了NO的产生，辛伐他汀减轻了这种影响。结论血脂异常会上调内皮miR-652-3p，从而降低ISL1蛋白水平，eNOS激活和NO生成。辛伐他汀疗法可降低血脂异常情况下内皮miR-652-3p的表达，从而保护内皮功能。