Induction of VEGF gene transcription by IL-1 beta is mediated through stress-activated MAP kinases and Sp1 sites in cardiac myocytes.
Interleukin-1 beta (IL-1 beta) is a multipotent cytokine participating in a variety of cardiovascular diseases. In this study, we examined the effects of IL-1 beta on the expression of vascular endothelial cell growth factor (VEGF) and pursued the molecular mechanisms underlying this effect. Treatment of cultured neonatal rat cardiac myocytes with IL-1 beta increased the levels of VEGF mRNA in a time- and a concentration-dependent manner. These effects were completely abolished by SB203580 and SB202190 (p38 MAPK inhibitors) but not by PD98059 (MEK1 inhibitor), calphostin C (protein kinase C inhibitor), or genistein (tyrosine kinase inhibitor). While IL-1 beta phosphorylated c-Jun N-terminus protein kinase (JNK) rapidly and transiently, the effect of IL-1 beta on p38 mitogen-activated protein kinase (MAPK) was gradual and persistent. Transient transfection assays showed that IL-1 beta increases the transcription from the VEGF promoter. A series of 5;-deletion and site-specific mutation analyses indicated that IL-1 beta as well as overexpression of p38 MAPK and JNK activate VEGF promoter activity through two G+C-rich sequences located at -73 and -62. Electrophoretic mobility shift and supershift assays showed Sp1 and Sp3 proteins specifically bind to the G+C-rich sequences. The half-life of VEGF mRNA was significantly increased in cells treated with IL-1 beta. Together, these results indicate that IL-1 beta induces VEGF gene expression at both transcriptional and post-transcriptional levels, and IL-1 beta evokes p38 MAPK and JNK signalings, which in turn stimulate the transcription of the VEGF gene through Sp1-binding sites. These findings suggest the role of IL-1 beta as a cytokine inducing VEGF in cardiac myocytes, and imply that activation of stress-activated MAP kinases regulate Sp1 sites-dependent transcription.
Tanaka
T
T
Second Department of Internal Medicine, Gunma University School of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma, 371-8511, Japan.
Kanai
H
H
Sekiguchi
K
K
Aihara
Y
Y
Yokoyama
T
T
Arai
M
M
Kanda
T
T
Nagai
R
R
Kurabayashi
M
M
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D015237:Dinoprost / Q000494:pharmacology; D016228:Endothelial Growth Factors / Q000096:biosynthesis* / Q000235:genetics; D019332:Endothelin-1 / Q000494:pharmacology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D019833:Genistein / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D007375:Interleukin-1 / Q000235:genetics / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases; D008070:Lipopolysaccharides / Q000494:pharmacology; D008222:Lymphokines / Q000096:biosynthesis* / Q000235:genetics; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009281:Naphthalenes / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013312:Stress, Physiological / Q000201:enzymology; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D048051:p38 Mitogen-Activated Protein Kinases
D016228:Endothelial Growth Factors; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D007093:Imidazoles; D007375:Interleukin-1; D008070:Lipopolysaccharides; D008222:Lymphokines; D009281:Naphthalenes; D019384:Nucleic Acid Synthesis Inhibitors; D011725:Pyridines; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D016329:Sp1 Transcription Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C061465:calphostin complex; D003609:Dactinomycin; D015237:Dinoprost; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole