The oxidized phospholipid POVPC impairs endothelial function and vasodilation via uncoupling endothelial nitric oxide synthase
The oxidized phospholipid POVPC impairs endothelial function and vasodilation via uncoupling endothelial nitric oxide synthase
复制标题
氧化磷脂 POVPC 通过解偶联内皮一氧化氮合酶损害内皮功能和血管舒张
DOI：
10.1016/j.yjmcc.2017.08.016
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发表时间：
2017
影响因子：
5
通讯作者：
Ou Jing Song
中科院分区：
文献类型：
--
作者：
Yan Feng Xia;Li Hua Ming;Li Shang Xuan;He Shi Hui;Dai Wei Ping;Li Yan;Wang Tian Tian;Shi Mao Mao;Yuan Hao Xiang;Xu Zhe;Zhou Jia Guo;Ning Da Sheng;Mo Zhi Wei;Ou Zhi Jun;Ou Jing Song
内皮功能障碍是动脉粥样硬化的早期阶段。我们最近发现，动脉粥样硬化病变中发现的25-羟基胆固醇可以通过解偶联和抑制内皮型一氧化氮合酶（eNOS）来损害内皮功能和血管舒张。1-棕榈酰-2-（5-氧代戊酰）-sn-甘油-3-磷酸胆碱（POVPC）是氧化低密度脂蛋白的氧化产物，是另一种促炎脂质，也见于动脉粥样硬化病变。然而，POVPC是否像25-羟基胆固醇一样促进动脉粥样硬化仍不清楚。本研究旨在探讨POVPC对内皮功能和血管舒张功能的影响。将人脐静脉内皮细胞（HUVEC）与POVPC孵育。测定内皮细胞增殖、迁移和管腔形成。测定了一氧化氮（NO）的产生和超氧阴离子（O2 radical dot−）的产生。免疫印迹和免疫沉淀法检测内皮型一氧化氮合酶（eNOS）、AKT、PKC-βII和P70 S6 K的表达和磷酸化，以及eNOS与热休克蛋白90（HSP 90）的结合。通过原位末端标记（TUNEL）染色监测内皮细胞凋亡。免疫印迹法检测Bcl-2、Bax、Cleaved Caspase 3的表达。最后，分离C57 BL 6小鼠的主动脉环并用POVPC处理，并评价内皮依赖性血管舒张。POVPC显著抑制HUVECs增殖、迁移、管腔形成，减少NO生成，但增加O2自由基点−生成。POVPC可抑制Akt和eNOS的Ser 1177磷酸化，增加PKC-βII、P70 S6 K的活化和eNOS的Thr 495磷酸化，减少HSP 90与eNOS的结合。同时，POVPC通过抑制Bcl-2表达，增加Bax和切割型caspase-3的表达及caspase-3活性，损害内皮依赖性血管舒张功能，诱导内皮细胞凋亡。这些数据表明，POVPC通过解偶联和抑制eNOS以及诱导内皮细胞凋亡来损害内皮功能。因此，POVPC可能在动脉粥样硬化的发展中起重要作用，并可能被认为是动脉粥样硬化的潜在治疗靶点。
Endothelial dysfunction is an early stage of atherosclerosis. We recently have shown that 25-hydroxycholesterol found in atherosclerotic lesions could impair endothelial function and vasodilation by uncoupling and inhibiting endothelial nitric oxide synthase (eNOS). 1-Palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), the oxidation product of oxidized low-density lipoprotein, is another proinflammatory lipid and has also been found in atherosclerotic lesions. However, whether POVPC promotes atherosclerosis like 25-hydroxycholesterol remains unclear. The purpose of this study was to explore the effects of POVPC on endothelial function and vasodilation. Human umbilical vein endothelial cells (HUVECs) were incubated with POVPC. Endothelial cell proliferation, migration and tube formation were measured. Nitric oxide (NO) production and superoxide anion generation (O2radical dot−) were determined. The expression and phosphorylation of endothelial nitric oxide synthase (eNOS), AKT, PKC-βII and P70S6K as well as the association of eNOS and heat shock protein 90 (HSP90) were detected by immunoblotting and immunoprecipitation. Endothelial cell apoptosis was monitored by TUNEL staining. The expression of Bcl-2, Bax, and Cleaved Caspase 3 were detected by immunoblotting. Finally, aortic ring from C57BL6 mice were isolated and treated with POVPC and the endothelium-dependent vasodilation was evaluated. POVPC significantly inhibited HUVECs proliferation, migration, tube formation, decreased NO production but increased O2radical dot−generation. POVPC inhibited the phosphorylation of Akt and eNOS at Ser1177, increased activation of PKC-βII, P70S6K and the phosphorylation of eNOS at Thr495, reduced the association of HSP90 with eNOS. Meanwhile, POVPC induced endothelial cell apoptosis by inhibiting Bcl-2 expression, increasing Bax and cleaved caspase-3 expressions as well as caspase-3 activity and impaired endothelium-dependent vasodilation. These data demonstrated that POVPC impaired endothelial function by uncoupling and inhibiting eNOS as well as by inducing endothelial cell apoptosis. Therefore, POVPC may play an important role in the development of atherosclerosis and may be considered as a potential therapeutic target for atherosclerosis.