title: Mitogen-activated protein kinases Erk1/2 and p38 are required for maximal regulation of TIMP-1 by oncostatin M in murine fibroblasts.
abstract: Oncostatin M (OSM) regulates expression of various genes in connective tissue (CT) cells, including tissue inhibitor of metalloproteinases-1 (TIMP-1). In mouse fibroblast cell lines MLg, NIH 3T3 and primary mouse lung fibroblasts (MLF), murine OSM (muOSM) stimulated high TIMP-1 mRNA expression in comparison to leukemia inhibitory factor (LIF), epidermal growth factor (EGF), interleukin (IL)-1beta and transforming growth factor (TGF)beta. In cell signaling, muOSM induced strong phosphorylation of extracellular-signal regulated protein kinase (Erk) 1/2, p38 and Akt in addition to phosphorylation of signal transducer and activator of transcription (STAT) 1, STAT3 and STAT5 within 15 min. LIF and TGFbeta had no such effects. EGF stimulated comparable or lower Erk1/2, p38 and Akt phosphorylation while IL-1beta induced p38 phosphorylation in the fibroblast cell lines. The Erk1/2 inhibitor PD98059 and the p38 inhibitor SB203580 inhibited TIMP-1 mRNA response to muOSM, whereas the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 enhanced the TIMP-1 mRNA response in NIH 3T3 and MLg cells. PD98059 and SB203580, but not LY294002, also inhibited fold induction of a chloramphenicol acetyltransferase (CAT) reporter gene driven by a minimal TIMP-1 promoter that contained a proximal activator protein-1 (AP-1) site. Co-transfection with JunB or c-Jun expression vector in NIH 3T3 cells caused marked transactivation of the TIMP-1 promoter/CAT reporter gene. muOSM caused a rapid increase of JunB and c-Jun protein in NIH 3T3 cells. PD98059 partially inhibited the increase of JunB, but not c-Jun, whereas SB203580 did not induce detectable changes in expression of either AP-1 factor in response to muOSM. These results demonstrate that Erk1/2 and p38 contribute to the elevation of muOSM induced TIMP-1 expression, but PI3K does not, and suggest that Erk1/2 does so by enhancing JunB expression.
authors.affiliation: Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, HSC-4H17, 1200 Main Stree West, Hamilton, ON, Canada L8S 3Z5.
authors.forename: Li
authors.initials: L
authors.lastname: Tong
authors.forename: David
authors.initials: D
authors.lastname: Smyth
authors.forename: Christine
authors.initials: C
authors.lastname: Kerr
authors.forename: Jonathon
authors.initials: J
authors.lastname: Catterall
authors.forename: Carl D
authors.initials: CD
authors.lastname: Richards
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D016758:Genes, jun / Q000502:physiology; D007375:Interleukin-1 / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D041681:NIH 3T3 Cells; D053683:Oncostatin M; D010455:Peptides / Q000494:pharmacology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D007375:Interleukin-1; C508352:Osm protein, mouse; D010455:Peptides; D011518:Proto-Oncogene Proteins; D019715:Tissue Inhibitor of Metalloproteinase-1; D053683:Oncostatin M; D004815:Epidermal Growth Factor; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases