Propionyl-L-carnitine induces eNOS activation and nitric oxide synthesis in endothelial cells via PI3 and Akt kinases
Propionyl-L-carnitine induces eNOS activation and nitric oxide synthesis in endothelial cells via PI3 and Akt kinases
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DOI：
10.1016/j.vph.2013.07.001
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发表时间：
2013-09-01
影响因子：
4
通讯作者：
Zhao, Kan
中科院分区：
文献类型：
--
作者：
Ning, Wen-hu;Zhao, Kan
丙酰-L-肉毒碱（PLC）是L-肉毒碱（LC）的天然短链衍生物，L-肉毒碱是一种天然氨基酸，在脂肪酸代谢中起重要作用。最近的研究表明PLC具有血管保护作用。由于内皮型一氧化氮合酶（eNOS）及其产物抗动脉粥样硬化分子一氧化氮（NO）在血管内皮功能中的重要性，我们试图阐明PLC是否会刺激培养的人主动脉内皮细胞（HAEC）中的eNOS及其上游激活剂Akt和磷脂酰肌醇3-激酶（PI 3 Kinase）。PLC引起eNOS在Ser-1177处的磷酸化，并且显性负性Ala和新型Akt选择性抑制剂MK-2206抑制PLC介导的磷酸化和酶的活化。PI 3激酶抑制也阻断了PLC对eNOS的磷酸化和激活。使用特异性药物抑制剂PD 173955和PP 2的研究表明，非受体酪氨酸激酶src是该途径中PI 3激酶-Akt途径的上游刺激物。此外，PLC还能显著降低细胞内ATP/ADP比值，激活AMPK，进而激活Src。最后，我们证明了PLC增强eNOS活性的作用与内皮细胞NO释放的净增加有关。在与L-NAME、PD 173955、LY 294002、MK-2206和化合物C共孵育的内皮细胞中，与PLC孵育后的NO产生被消除。总之，PLC，通过AMPK/Src介导的信号传导，导致PI 3激酶和Akt的激活，刺激eNOS，导致NO的产生增加。版权所有：
Propionyl-L-carnitine (PLC) is a natural short-chain derivative of L-carnitine (LC), a natural amino acid that plays an important role in fatty acid metabolism. Recent studies suggest that PLC has vascular protective effects. Because of the importance of endothelial nitric oxide synthase (eNOS) and its product, antiatherogenic molecule nitric oxide (NO), in vascular endothelial function, we sought to elucidate that if PLC would stimulate eNOS and its upstream activators Akt and phosphatidylinositol 3-kinase (PI3 Kinase) in cultured human aortic endothelial cells (HAEC). PLC caused eNOS phosphorylation at Ser-1177, and dominant negative Ala and a novel Akt-selective inhibitor MK-2206 inhibited both PLC-mediated phosphorylation and activation of the enzyme. PI3 kinase inhibition also blocked the phosphorylation and activation of eNOS by PLC. Studies with specific drug inhibitors PD173955 and PP2 showed that the non-receptor tyrosine kinase, src, is an upstream stimulator of the PI3 kinase-Akt pathway in this pathway. In addition, PLC significantly decreased intracellular ATP/ADP ratio and activate AMPK, subsequently leading to Src activation. Finally, we demonstrated that the effects of PLC to augment eNOS activity were associated with a net increase in NO release from endothelial cells. NO production following incubation with PLC was abolished in endothelial cells coincubated with L-NAME, PD173955, LY294002, MK-2206 and compound C. In conclusion, PLC, via AMPK/Src-mediated signaling that leads to activation of PI3 kinase and Akt, stimulates eNOS, leading to increased production of NO. (C) 2013 Elsevier Inc. All rights reserved: