title: Sphingosine-1-phosphate receptor 2 mediates endothelial cells dysfunction by PI3K-Akt pathway under high glucose condition.
abstract: Endothelial dysfunction is believed the early stage of development of diabetic cardiovascular complications. Sphingosine-1-phosphate (S1P) regulates various biological activities by binding to sphingosine-1-phosphate receptors (S1PRs) including S1PR1-S1PR5. In the present study, the role of S1P receptors in S1P-induced human coronary artery endothelial cells (HCAECs) dysfunction under high glucose condition was investigated and the underlying mechanism was explored. S1PR1-S1PR5 mRNA levels were detected by quantitative Real-time PCR. NO level and polymorphonuclear neutrophils (PMN)-endothelial cells adhesion were measured by nitrate reductase and myeloperoxidase colorimetric method, respectively. Protein levels of endothelial nitric oxide synthase (eNOS), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1(ICAM-1), phosphatidylinositol 3-kinase (PI3K) and Akt were measured by Western blot analysis. S1PR2 were found the predominant S1P receptor expressed in HCAECs exposed to high glucose. NO level and eNOS activity were remarkably decreased, while PMN adhesion, VCAM-1 and ICAM-1 protein levels were increased significantly by S1P treatment in HCAECs exposed to high glucose and normal glucose. Blockage of S1PR2 with specific antagonist JTE-013 and small interfering RNA (siRNA) resulted in enhanced NO level and eNOS activity as well as decreased PMN adhesion, reduced protein levels of VCAM-1 and ICAM-1 induced by S1P. Furthermore, Phosphor-PI3K and phosphor-Akt level were markedly increased by S1PR2 blockade in S1P-treated cells exposed to high glucose, which were suppressed by PI3K inhibitor wortmannin. In conclusion, S1P/S1PR2 mediated endothelial dysfunction partly by inhibiting PI3K/Akt signaling pathway under high glucose condition. S1PR2 blockage could ameliorate endothelial dysfunction which might provide a potential therapeutic strategy for diabetic vascular complications.
authors.affiliation: Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510260, PR China. Electronic address: liuweihua.96@163.com.
authors.forename: Weihua
authors.initials: W
authors.lastname: Liu
authors.affiliation: Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510260, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510260, PR China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Liu
authors.affiliation: Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510260, PR China.
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Experiment Center, The First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, Guangdong 510405, PR China. Electronic address: linshfeng2004@163.com.
authors.forename: Shuangfeng
authors.initials: S
authors.lastname: Lin
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D049349:Receptors, Lysosphingolipid / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000081025:Sphingosine-1-Phosphate Receptors
chemical_list: D008246:Lysophospholipids; D049349:Receptors, Lysosphingolipid; C477522:S1PR2 protein, human; D000081025:Sphingosine-1-Phosphate Receptors; C060506:sphingosine 1-phosphate; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D058539:Phosphatidylinositol 3-Kinase; D051057:Proto-Oncogene Proteins c-akt; D005947:Glucose; D013110:Sphingosine
keywords: Akt; Diabetes; Endothelial cells; PI3K; Sphingosine-1-phosphate; Sphingosine-1-phosphate receptor 2