title: Coordinate expression of matrix-degrading proteinases and their activators and inhibitors in bovine skeletal muscle.
abstract: Matrix metalloproteinases (MMP) responsible for degradation of connective tissue are found in most tissues. The MMP are regulated at the levels of transcription, zymogen activation by plasmin or membrane-type- (MT) MMP, and control of enzyme activity by tissue inhibitors of metalloproteinases (TIMP). Whole bovine skeletal muscle showed multiple MMP activities on gelatin zymography and also expressed mRNA encoding MMP-1, -2, -9, -14, and -16, tissue inhibitors of metalloproteinase (TIMP)-1, -2, and -3 and plasminogen activator and its receptor. Purified intramuscular fibroblasts and myogenic cell culture derived from satellite cells expressed most or all of these elements. Statistical analysis (n = 35) revealed a strong positive correlation among the mRNA levels of several elements of the MMP system, including MMP-2, MMP-14, TIMP-1, -2, and -3 (r = 0.614 to 0.930, P < 0.0001). Our results provide an extensive profile of an extracellular proteolytic cascade involving MMP in skeletal muscle and suggest that 1) the activation cascades of muscle MMP may be initiated by both plasmin and membrane-type MMP; 2) a group of genes involved in the same "arm" of zymogen activation are coexpressed in this tissue; and 3) skeletal muscle cells, in addition to the intramuscular fibroblasts, express an extensive complement of MMP and related proteins.
authors.affiliation: Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Balcerzak
authors.forename: L
authors.initials: L
authors.lastname: Querengesser
authors.forename: W T
authors.initials: WT
authors.lastname: Dixon
authors.forename: V E
authors.initials: VE
authors.lastname: Baracos
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002417:Cattle / Q000502:physiology*; D002478:Cells, Cultured; D004789:Enzyme Activation; D005347:Fibroblasts / Q000201:enzymology; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis / Q000235:genetics; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000235:genetics; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000201:enzymology*; D011480:Protease Inhibitors / Q000378:metabolism*; D012313:RNA / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis / Q000235:genetics; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis / Q000235:genetics; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000096:biosynthesis / Q000235:genetics; D019714:Tissue Inhibitor of Metalloproteinases / Q000096:biosynthesis* / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D011480:Protease Inhibitors; D019715:Tissue Inhibitor of Metalloproteinase-1; D019717:Tissue Inhibitor of Metalloproteinase-3; D019714:Tissue Inhibitor of Metalloproteinases; D019716:Tissue Inhibitor of Metalloproteinase-2; D012313:RNA; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1