title: Adiponectin inhibits tissue factor expression and enhances tissue factor pathway inhibitor expression in human endothelial cells.
abstract: Tissue factor (TF) plays a pivotal role in thrombus formation and atherogenesis in acute coronary syndrome. Tissue factor pathway inhibitor (TFPI) is a specific physiological inhibitor of TF/FVIIa complex that regulates TF-induced coagulation. Adiponectin (Adp) is an adipocyte-specific adipocytokine with anti-atherogenic and anti-diabetic properties. Adp inhibits inflammatory cytokine and adhesion molecules expression, and it can prevent endothelial dysfunction. In this study, we investigated the effects of Adp on tumor necrosis factor-alpha (TNF-alpha)-induced expression of TF and TFPI in human umbilical vein endothelial cells (HUVECs), and the signaling transduction pathways involved. It was found that Adp significantly inhibited both TF protein expression and activity in TNF-alpha-stimulated HUVECs. In the meanwhile, it increased TFPI protein expression and activity for about two folds. Adp also inhibited TF mRNA expression induced by TNF-alpha, but had no effect on TFPI mRNA expression. The inhibitory effect of Adp on TNF-alpha-induced TF expression was prevented by pretreatment with Rp-cAMPs, a PKA inhibitor. Adp increased intracellular cAMP content and PKA activity levels in a dose-dependent manner. Phosphorylation of IkappaB-alpha was decreased by Adp, but phosphorylation of p44/42 MAPK, SAPK/JNK, and p38 MAPK were not affected. These results suggested that Adp inhibits TF expression through inhibition of a PKA dependent nuclear factor-kappaB (NF-kappaB) signaling pathway. It was also found that adiponectin promoted Akt and AMP-activated protein kinase phosphorylation. The inhibitory effect of Adp on TNF-alpha-induced TF synthesis was abrogated in part by pretreatment with the PI3kinase inhibitor LY294002, suggesting that Akt activation might inhibit TF expression induced by TNF-alpha. The inhibitory effect of Adp is almost completely abrogated by inhibition of both the cAMP/PKA pathway and PI3K/Akt pathway. In conclusion, our data indicated that inhibition of NF-kappaB through stabilization of IkappaB-alpha and activation of Akt phosphorylation may mediate the inhibitory effect of Adp on TF expression; but the enhancement effect of Adp on the TFPI production might occur via translational rather than transcriptional regulation.
authors.affiliation: Department of Hematology, Xiang Ya Hospital, Central South University, ChangSha, PR China.
authors.forename: Yi-Jian
authors.initials: YJ
authors.lastname: Chen
authors.forename: Li-Qun
authors.initials: LQ
authors.lastname: Zhang
authors.forename: Guang-Ping
authors.initials: GP
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Zeng
authors.forename: Ben
authors.initials: B
authors.lastname: Lü
authors.forename: Xu-Liang
authors.initials: XL
authors.lastname: Shen
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Jiang
authors.forename: Fang-Ping
authors.initials: FP
authors.lastname: Chen
mesh_terms: D052242:Adiponectin / Q000378:metabolism / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D008074:Lipoproteins; D016328:NF-kappa B; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D013873:Thionucleotides; D014409:Tumor Necrosis Factor-alpha; C051928:lipoprotein-associated coagulation inhibitor; C016957:adenosine-3',5'-cyclic phosphorothioate; D000242:Cyclic AMP; D051057:Proto-Oncogene Proteins c-akt; D017868:Cyclic AMP-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases