Oxidative stress induced by palmitic acid modulates KCa2.3 channels in vascular endothelium
Oxidative stress induced by palmitic acid modulates KCa2.3 channels in vascular endothelium
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棕榈酸诱导的氧化应激调节血管内皮中的 KCa2.3 通道。
DOI：
10.1016/j.yexcr.2019.111552
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发表时间：
2019-10-15
影响因子：
3.7
通讯作者：
Deng, Xiu-Ling
中科院分区：
文献类型：
--
作者：
Wang, Yan;Wang, Xiao-Jing;Deng, Xiu-Ling
血浆游离脂肪酸水平升高与糖尿病和非糖尿病个体的胰岛素抵抗、炎症和内皮功能障碍的发展有关。然而，基本机制仍有待确定。在此，我们研究了人体中最丰富的饱和脂肪酸棕榈酸（PA）对小电导钙激活钾通道（K（Ca）2.3）介导的啮齿动物阻力动脉舒张的影响及其分子机制。采用实时荧光定量PCR、Western blotting、全细胞膜片钳、压力肌电描记仪、压力肌电描记仪等方法观察PA对内皮细胞K（Ca）2.3的影响，并采用二氢乙锭和2 '，7'-二氯荧光素二乙酸酯测定活性氧（ROS）。用100 μ M PA孵育正常肠系膜动脉24小时，可使K（Ca）2.3介导的血管舒张反应受到乙酰胆碱和NS 309（K（Ca）2.3和K（Ca）3.1的激动剂）的损害。在培养的人脐静脉内皮细胞（HUVECs）中，PA在mRNA和蛋白水平上降低K（Ca）2.3电流和表达。NADPH氧化酶（Nox）抑制剂dibenziodolium（DPI）可部分抑制PA诱导的ROS产生，并恢复K（Ca）2.3的表达。使用特异性抑制剂（SB 203580、SB 202190或Bay 11 -7082，吡咯烷二硫代氨基甲酸酯）抑制p38-MAPK或NF-κ B减弱PA诱导的K（Ca）2.3下调，抑制p38-MAPK也减弱PA诱导的NF-κ B p65磷酸化。此外，DPI还逆转了PA对磷酸化p38-MAPK的增加。这些结果表明，PA通过Nox/ROS/p38-MAPK/NF-κ B信号转导下调K（Ca）2.3表达，导致内皮舒张功能障碍。
Elevated plasma free fatty acids level has been implicated in the development of insulin resistance, inflammation, and endothelial dysfunction in diabetic and nondiabetic individuals. However, the underlying mechanisms still remain to be defined. Herein, we investigated the effect of palmitic acid (PA), the most abundant saturated fatty acid in the human body, on small-conductance Ca2+-activated potassium channels (K(Ca)2.3)-mediated relaxation in rodent resistance arteries and the underlying molecular mechanism. The effect of PA on K(Ca)2.3 in endothelium was evaluated using real-time PCR, Western blotting, whole-cell patch voltage-clamp, wire and pressure myograph system, and reactive oxygen species (ROS) were measured by using dihydroethidium and 2', 7'-dichlorofluorescein diacetate. K(Ca)2.3-mediated vasodilatation responses to acetylcholine and NS309 (agonist of K(Ca)2.3 and K(Ca)3.1) were impaired by incubation of normal mesenteric arteries with 100 mu M PA for 24 h. In cultured human umbilical vein endothelial cells (HUVECs), PA decreased K(Ca)2.3 current and expression at mRNA and protein levels. Incubation with the NADPH oxidase (Nox) inhibitor dibenziodolium (DPI) partly inhibited the PA-induced ROS production and restored K(Ca)2.3 expression. Inhibition of either p38-MAPK or NF-kappa B using specific inhibitors (SB203580, SB202190 or Bay11-7082, pyrrolidinedithiocarbamate) attenuated PA-induced downregulation of K(Ca)2.3 and inhibition of p38-MAPK also attenuated PA-induced phosphorylation of NF-kappa B p65. Furthermore, DPI reversed the increment of phospho-p38-MAPK by PA. These results demonstrated that PA downregulated K(Ca)2.3 expressions via Nox/ROS/p38-MAPK/NF-kappa B signaling leading to endothelial vasodilatory dysfunction.