Effects of epoxyeicosatrienoic acids on levels of eNOS phosphorylation and relevant signaling transduction pathways involved

作     者：CHEN Ruijuan1, JIANG Jiangang1, XIAO Xiao2 & WANG Daowen1 1. The Institute of Hypertension and Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430030, China 2. Departments of Molecular Genetics and Biochemistry & Gene Therapy Center, University of Pittsburgh, Pittsburgh, PA, USA 

作者机构：1. The Institute of Hypertension and Department of Internal Medicine Tongji Hospital Tongji Medical College Huazhong University of Science & Technology 430030 Wuhan China 2. Departments of Molecular Genetics and Biochemistry & Gene Therapy Center University of Pittsburgh Pittsburgh PA USA 

出 版 物：《Science China(Life Sciences)》 (中国科学（生命科学英文版）)

年 卷 期：2005年第48卷第5期

页      面：495-505页

核心收录：

学科分类：1001[医学-基础医学(可授医学、理学学位)] 10[医学] 

基　　金：This work was supported by the National Natural Science Foundation(Grant Nos.39870307 30270561&30430320) 

主　　题：epoxyeicosatrienoic acids, endothelial nitric oxide synthase (eNOS), PI3 kinase, Protein kinase B (Akt), phosphorylation. 

摘      要：Endothelial nitric oxide synthase (eNOS) is a key enzyme responsible for the regu-lation of vascular homeostasis. Many humor factors and mechanical forces can affect eNOS ac-tivity via phosphorylation modification but the mechanisms involved vary with stimuli applied. We have demonstrated that cytochrome P450 (CYP) epoxygenase-dependent metabolites of ara-chidonic acid, epoxyeicosatrienoic acids (EETs), can robustly up-regulate eNOS expression and its activity, however the relevant signaling pathways responsible for activity regulation are not well known. In this study, we explored the role of PI3 kinase (PI3K)/protein kinase B (Akt) sig-naling pathway in eNOS expression and its phosphorylation in response to EETs via direct addi-tion of EETs into cultured bovine aorta endothelial cells (BAECs) and recombinant adeno- asso-ciated virus-mediated transfection of CYP epoxygenase genes CYPF87V and CYP2C11 to pro-duce endogenous EETs followed by co-treatment with PI3K or Akt inhibitor. Results show that both exogenous and endogenous EETs could remarkably enhance eNOS expression and its phosphorylation at Ser1179 and Thr497 residues; PI3K inhibitor LY294002 could inhibit EETs-induced increase in eNOS-Ser(P)1179 but had no effect on the change of eNOS-Thr(P)497, while Akt inhibitor could attenuate the increase in phosphor-eNOS at both residues; both of the two inhibitors could block EETs-enhanced eNOS expression. These results lead to conclusions: (i) EETs-mediated regulation of eNOS activity may be related with the changes of phosphoryla-tion level at eNOS-Ser1179 via PI3K/Akt and eNOS-Thr497 via Akt; (ii) PI3K/Akt signaling pathway is involved in the up-regulation of eNOS expression by EETs.