title: Resistin decreases expression of endothelial nitric oxide synthase through oxidative stress in human coronary artery endothelial cells.
abstract: Resistin is a newly discovered adipocyte-derived cytokine that may play an important role in insulin resistance, diabetes, adipogenesis, inflammation, and cardiovascular disease. However, it is largely unknown whether resistin impairs endothelial functions by affecting the endothelial nitric oxide synthase (eNOS) system. In this study, we determined the effect of human recombinant resistin protein on eNOS expression and regulation in human coronary artery endothelial cells (HCAECs). When cells were treated with clinically relevant concentrations of resistin (40 or 80 ng/ml) for 24 h, the levels of eNOS mRNA, protein, and activity and eNOS mRNA stability were significantly reduced. Cellular nitric oxide levels were also decreased. In addition, the cellular levels of reactive oxygen species (ROS), including superoxide anion, were significantly increased in resistin-treated HCAECs. Mitochondrial membrane potential and the activities of catalase and superoxide dismutase were reduced. Three antioxidants, seleno-L-methionine, ginsenoside Rb1, and MnTBAP (superoxide dismutase mimetic), effectively blocked resistin-induced eNOS downregulation. Meanwhile, resistin activated the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase (JNK), and the specific p38 inhibitor SB-239063 effectively blocked resistin-induced ROS production and eNOS downregulation. Furthermore, immunoreactivity of resistin was increased in atherosclerotic regions of human aorta and carotid arteries. Thus resistin directly induces eNOS downregulation through overproduction of ROS and activation of p38 and JNK in HCAECs. Resistin-induced mitochondrial dysfunction and imbalance in cellular redox enzymes may be the underlying mechanisms of oxidative stress.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Michael E. DeBakey Dept. of Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. jchen@bcm.tmc.edu
authors.forename: Changyi
authors.initials: C
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Lü
authors.forename: Hong
authors.initials: H
authors.lastname: Chai
authors.forename: Xinwen
authors.initials: X
authors.lastname: Wang
authors.forename: Peter H
authors.initials: PH
authors.lastname: Lin
authors.forename: Qizhi
authors.initials: Q
authors.lastname: Yao
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology; D050197:Atherosclerosis / Q000201:enzymology / Q000473:pathology; D002374:Catalase / Q000378:metabolism; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D052243:Resistin / Q000378:metabolism*; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D047428:Protein Kinase Inhibitors; C499624:RETN protein, human; D012333:RNA, Messenger; D011994:Recombinant Proteins; D052243:Resistin; D013481:Superoxides; D009569:Nitric Oxide; D000255:Adenosine Triphosphate; D002374:Catalase; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D013482:Superoxide Dismutase; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases