title: Regulation of TGF-beta 1-induced connective tissue growth factor expression in airway smooth muscle cells.
abstract: Transforming growth factor (TGF)-beta may play an important role in airway remodeling, and the fibrogenic effect of TGF-beta may be mediated through connective tissue growth factor (CTGF) release. We investigated the role of MAPKs and phosphatidylinositol 3-kinase (PI3K) and the effects of inflammatory cytokines on TGF-beta-induced CTGF expression in human airway smooth muscle cells (ASMC). We examined whether Smad signal was involved in the regulatory mechanisms. TGF-beta 1 induced a time- and concentration-dependent expression of CTGF gene and protein as analyzed by real-time RT-PCR and Western blot. Inhibition of ERK and c-jun NH(2)-terminal kinase (JNK), but not of p38 MAPK and PI3K, blocked the effect of TGF-beta 1 on CTGF mRNA and protein expression and on Smad2/3 phosphorylation. T helper lymphocyte 2-derived cytokines, IL-4 and IL-13, attenuated TGF-beta 1-stimulated mRNA and protein expression of CTGF and inhibited TGF-beta 1-stimulated ERK1/2 and Smad2/3 activation in ASMC. The proinflammatory cytokines tumor necrosis factor-alpha and IL-1 beta reduced TGF-beta 1-stimulated mRNA expression of CTGF but did not inhibit TGF-beta-induced Smad2/3 phosphorylation. TGF-beta 1-stimulated CTGF expression is mediated by mechanisms involving ERK and JNK pathways and is downregulated by IL-4 and IL-13 through modulation of Smad and ERK signals.
authors.affiliation: Thoracic Medicine, National Heart and Lung Institute, Imperial College, Dovehouse St., London SW3 6LY, UK.
authors.forename: Shaoping
authors.initials: S
authors.lastname: Xie
authors.forename: Maria B
authors.initials: MB
authors.lastname: Sukkar
authors.forename: Razao
authors.initials: R
authors.lastname: Issa
authors.forename: Ute
authors.initials: U
authors.lastname: Oltmanns
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Nicholson
authors.forename: Kian Fan
authors.initials: KF
authors.lastname: Chung
mesh_terms: D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D004268:DNA-Binding Proteins / Q000378:metabolism; D004347:Drug Interactions; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007375:Interleukin-1 / Q000494:pharmacology; D018793:Interleukin-13 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C526317:CCN2 protein, human; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D007375:Interleukin-1; D018793:Interleukin-13; D012333:RNA, Messenger; D011994:Recombinant Proteins; D051785:Smad Proteins; C508960:TGFB1 protein, human; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D055513:Connective Tissue Growth Factor; D015847:Interleukin-4; D019869:Phosphatidylinositol 3-Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases