Stimulation of endothelin-1 gene expression by insulin via phosphoinositide-3 kinase-glycogen synthase kinase-3beta signaling in endothelial cells.
Insulin stimulates secretion of the potent vasoactive and mitogenic peptide endothelin-1 (ET-1) from endothelial cells. We sought to investigate whether phosphoinositide-3 kinase (PI3K)-dependent inactivation of glycogen synthase kinase-3beta (GSK3beta) by insulin leads to elevation of ET-1 gene expression in endothelial cells. Inhibition of GSK3beta activity by LiCl or siRNA technique mimicked insulin action to stimulate ET-1 gene expression. Luciferase reporter assay showed insulin stimulated-elevation of ET-1 promoter activity can be abolished by the PI3K inhibitor Wortmannin, but not by the mitogen activated protein kinase (MAPK) inhibitor PD-98059. To further investigate whether the transcription factor vascular endothelial zinc finger-1 (Vezf1) is involved in ET-1 regulation, site-mutated reporter plasmid was used in luciferase reporter assay. A 2-bp mutation in Vezf1 binding element abolished insulin-stimulated elevation of ET-1 promoter activity. Furthermore, siRNA inhibition of Vezf1 led to decline in the levels of ET-1 mRNA and ET-1 peptides. These observations indicate that PI3K-dependent inactivation of GSK3beta by insulin leads to upregulation of ET-1 gene expression and Vezf1 may be a target for ET-1 regulation by insulin. PI3K-GSK3beta signaling may be responsible for insulin stimulation of ET-1 production associated with insulin resistance and hyperinsulinemia.
Yang
Zeran
Z
Institute of Cell Biology, Zhejiang University, Hangzhou, China.
Li
Ji-Cheng
JC
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D018021:Lithium Chloride / Q000494:pharmacology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011401:Promoter Regions, Genetic / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013552:Swine; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000077191:Wortmannin
D000730:Androstadienes; D004268:DNA-Binding Proteins; D019332:Endothelin-1; D005419:Flavonoids; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D007328:Insulin; D018021:Lithium Chloride; D008156:Luciferases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000077191:Wortmannin; C088395:VEZF1 protein, human; C000605506:GSK3B protein, human; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one