Up-regulation of tissue inhibitor of metalloproteinases-3 gene expression by TGF-beta in articular chondrocytes is mediated by serine/threonine and tyrosine kinases.
The balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) regulates extracellular matrix turn-over in normal animal development, cancer cell metastasis, atherosclerotic plaque rupture and erosion of arthritic cartilage. Transforming growth factor beta (TGF-beta), an inducer of matrix synthesis, potently enhances mRNA and protein of a recently characterized MMP inhibitor, TIMP-3, in bovine articular chondrocytes. We examined the implication of protein kinases in the TGF-beta-mediated induction of TIMP-3 expression by utilizing activators and inhibitors of these enzymes. Protein kinase A activators, dibutyryl cyclic AMP, or forskolin had little or no effect, respectively, while phorbol 12-myristate 13-acetate (PMA), a PKC activator, increased TIMP-3 gene expression. H7, a serine/threonine protein kinase inhibitor, markedly reduced the response of TIMP-3 gene to TGF-beta. Furthermore, two protein tyrosine kinase inhibitors, genistein and herbimycin A, inhibited TGF-beta induction of TIMP-3. H7 and genistein also suppressed TGF-beta-induced TIMP-3 protein expression. These results suggest that TGF-beta signaling for TIMP-3 gene induction involves H7-sensitive serine/threonine kinase as well as herbimycin A- and genistein-sensitive protein tyrosine kinases.
Louis-Charles Simard Research Centre, CHUM, Department of Medicine, University of Montreal, Quebec, Canada.
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Zafarullah
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000235:genetics*; D015533:Transcriptional Activation; D016212:Transforming Growth Factor beta / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology*
D004791:Enzyme Inhibitors; D019717:Tissue Inhibitor of Metalloproteinase-3; D016212:Transforming Growth Factor beta; D003994:Bucladesine; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D013755:Tetradecanoylphorbol Acetate