Suppression of Kv1.5 protects against endothelial apoptosis induced by palmitate and in type 2 diabetes mice
Suppression of Kv1.5 protects against endothelial apoptosis induced by palmitate and in type 2 diabetes mice
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Kv1.5 的抑制可防止棕榈酸酯和 2 型糖尿病小鼠诱导的内皮细胞凋亡。
DOI：
10.1016/j.lfs.2015.12.054
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发表时间：
2017-01-01
期刊：
影响因子：
6.1
通讯作者：
Wang, Guan-Lei
中科院分区：
文献类型：
--
作者：
Du, Jie-Yi;Yuan, Feng;Wang, Guan-Lei
目的：棕榈酸是一种常见的饱和游离脂肪酸，在体外培养的内皮细胞和2型糖尿病（T2 DM）患者体内诱导内皮细胞凋亡。本研究旨在探讨Kv 1. 5是否调控棕榈酸诱导的2型糖尿病内皮细胞凋亡和内皮功能障碍。流式细胞仪检测细胞凋亡。通过细胞计数测定试剂盒-8测定细胞活力。采用siRNA转染来敲低Kv1.5蛋白表达。用荧光探针检测细胞内和线粒体内活性氧和线粒体膜电位。采用高糖/高脂饲料喂养的雄性C57 BL/6小鼠，腹腔注射链脲佐菌素（35 mg/kg体重），建立T2 DM动物模型。siRNA沉默Kv1.5可减少棕榈酸诱导的内皮细胞凋亡、细胞内ROS生成、线粒体ROS生成和膜电位（Δ psi（m））改变，并降低caspase-3蛋白表达，同时增加细胞活力和Bcl-2/Bax比值。此外，我们观察到Kv1.5蛋白在T2 DM小鼠胸主动脉内皮细胞中的表达增加。沉默Kv1.5显著改善T2 DM小鼠胸主动脉环的内皮依赖性血管舒张。这些结果表明，抑制Kv1.5通过抑制内皮细胞介导的过量ROS产生和凋亡信号通路保护内皮细胞免受棕榈酸诱导的凋亡。提示Kv1.5可作为治疗T2 DM患者棕榈酸和脂质代谢诱导的内皮功能障碍的治疗靶点。(C)版权所有© 2016 Elsevier Inc.
Aims: Palmitate, a common saturated free fatty acid, induces endothelial apoptosis in vitro in culture endothelial cells and in vivo in type 2 diabetes mellitus (T2DM) patients. The present study aimed to investigate whether Kv1.5 regulates palmitate-induced endothelial apoptosis and endothelial dysfunction in T2DM.Main methods: In vitro experiments were carried out in primary human HUVEC5. Apoptosis was analyzed by flow cytometry. Cell viability was determined by Cell Counting Assay Kit-8. The siRNA transfection was employed to knockdown Kv1.5 protein expression. Intracellular and mitochondrial ROS, and mitochondrial membrane potential were detected using fluorescent probes. Male C57BL/6 mice fed with high-sucrose/fat diet were injected with streptozotocin (35 mg/kg body weight) to establish T2DM animal model.Key findings: We found that palmitate-induced endothelial apoptosis was parallel to a significant increase in endogenous Kv1.5 protein expression in endothelial cells. Silencing of Kv1.5 with siRNA reduced palmitateinduced endothelial apoptosis, intracellular ROS generation, mitochondrial ROS generation and membrane potential (Delta psi(m)) alteration and cleaved caspase-3 protein expression; while increased cell viability and ratio of Bcl-2/Bax. Furthermore, we observed that Kv1.5 protein expression increased in endothelial cells of thoracic aorta of T2DM mice. Silencing of Kv1.5 significantly improved the endothelium-dependent vasodilation in thoracic aortic rings of T2DM mice.Significance: These results demonstrate that suppression of Kv1.5 protects endothelial cells against palmitateinduced apoptosis via inhibiting mitochondria-mediated excessive ROS generation and apoptotic signaling pathway, suggesting that Kv1.5 may serve as a therapeutic target of treatment for endothelial dysfunction induced by palmitate and lipid metabolism in T2DM patients. (C) 2016 Elsevier Inc All rights reserved.