Tumor necrosis factor-alpha and troglitazone regulate plasminogen activator inhibitor type 1 production through extracellular signal-regulated kinase- and nuclear factor-kappaB-dependent pathways in cultured human umbilical vein endothelial cells.
Plasminogen activator inhibitor type 1 (PAI-1) plays a role in the development of atherosclerosis in diabetic patients. PAI-1 is produced by endothelial cells stimulated with various inflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, which induces insulin resistance. In diabetic patients, troglitazone, a thiazolidinedione, can lower the concentration of PAI-1. We investigated the TNF-alpha-induced signaling pathway that leads to PAI-1 synthesis and the target step of troglitazone in this pathway. TNF-alpha induced PAI-1 mRNA expression and protein production in human umbilical vein endothelial cells (HUVECs). A specific inhibitor for p38 mitogen-activated protein kinase, 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB 203580), and a protein kinase C inhibitor, calphostin C, had no inhibitory effects on TNF-alpha-induced PAI-1 secretion. A protein tyrosine kinase inhibitor, genistein, completely inhibited TNF-alpha-induced PAI-1 secretion, whereas an inhibitor of extracellular signal-regulated kinase (ERK) kinase, 2'-amino-3'-methoxyflavone (PD98059), and a nuclear factor-kappaB (NF-kappaB) inhibitor, emodin, partly inhibited TNF-alpha-induced PAI-1 secretion. Together, PD98059 and emodin completely inhibited TNF-alpha-induced PAI-1 secretion, suggesting that both NF-kappaB-dependent and NF-kappaB-independent pathways are involved in TNF-alpha-induced signal pathway to PAI-1 production and that the latter pathway is mediated by activation of ERK. Furthermore, we have shown that troglitazone inhibited both TNF-alpha-induced PAI-1 protein secretion and mRNA in HUVECs. Genistein, but neither PD98059 nor emodin, was additive to the inhibitory effect of troglitazone on TNF-alpha-induced PAI-1 secretion. These results indicate That ERK and NF-kappaB are possible targets of TNF-alpha and troglitazone in the regulation of PAI-1 production.
Hamaguchi
Erika
E
Department of Endocrinology and Metabolism, Kanazawa University Graduate School of Medical Science, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan.
Takamura
Toshinari
T
Shimizu
Akiko
A
Nagai
Yukihiro
Y
D015152:Blotting, Northern; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D016328:NF-kappa B / Q000502:physiology*; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis*; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D045162:Thiazolidinediones / Q000494:pharmacology*; D000077288:Troglitazone; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D002839:Chromans; D007004:Hypoglycemic Agents; D007375:Interleukin-1; D016328:NF-kappa B; D017395:Plasminogen Activator Inhibitor 1; D045162:Thiazolidinediones; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D020928:Mitogen-Activated Protein Kinases; D000077288:Troglitazone; D013755:Tetradecanoylphorbol Acetate