Role of P38 MAPK, AP-1, and NF-kappaB in interleukin-1beta-induced IL-8 expression in human vascular smooth muscle cells.
Interleukin (IL)-1 modulates the expression of various genes in normal and tumor cells. We investigated the molecular mechanisms underlying IL-1beta-induced expression of IL-8 mRNA and protein in human vascular smooth muscle cells (hVSMCs). P38 mitogen-activated protein kinase (MAPK) was activated after 5min of IL-1beta treatment, whereas the extracellular signal-regulated kinases, the c-jun amino-terminal kinases, and protein kinase B/Akt were not activated by IL-1beta. IL-1beta induced activation of a full-length IL-8 promoter-reporter construct. Deletional mutagenesis localized the IL-1beta-responsive domains to two regions (-133 to -98 and -85 to -50) that contain consensus binding sites for activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB), respectively. Site-directed mutagenesis of the 133-bp minimal promoter confirmed that these sites were required for promoter activity. Electrophoretic mobility shift assays confirmed that IL-1beta increased AP-1 and NF-kappaB DNA-binding activities in a time-dependent manner. SB203580, a specific P38 MAPK inhibitor, partially blocked IL-1beta induction of IL-8 mRNA, IL-8 promoter activity, and AP-1 nuclear extract binding but not NF-kappaB DNA binding. Our data demonstrate that AP-1 and NF-kappaB are essential transcription factors for IL-1beta-induced IL-8 gene expression in hVSMCs. P38 MAPK is involved in inducing IL-8 gene transcription via AP-1 activation in hVSMCs.
Chonnam National University Research Institute of Medical Sciences, Hakdong 5, Kwangju, Korea.
Young D
YD
Jung
Fan
F
Fan
David J
DJ
McConkey
Marina E
ME
Jean
Wenbiao
W
Liu
Niels
N
Reinmuth
Oliver
O
Stoeltzing
Syed A
SA
Ahmad
Alexander A
AA
Parikh
Naofumi
N
Mukaida
Lee M
LM
Ellis
D001665:Binding Sites; D015152:Blotting, Northern; D015153:Blotting, Western; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D016328:NF-kappa B / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D007375:Interleukin-1; D016209:Interleukin-8; D016328:NF-kappa B; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases