title: Type I collagen-induced MMP-2 activation coincides with up-regulation of membrane type 1-matrix metalloproteinase and TIMP-2 in cardiac fibroblasts.
abstract: Migration of cardiac fibroblasts is implicated in infarct healing and ventricular remodeling. Activation of matrix metalloproteinases induced by three-dimensional type I collagen, the principal component of the myocardial interstitium, is hypothesized to be essential for this migration. By utilizing primary cultures of cardiac fibroblasts and collagen lattice models, we demonstrated that type I collagen induced MMP-2 activation, and cells undergoing a change from isometric tension to mechanical unloading were associated with increased levels of total and active MMP-2 species. The collagen-induced MMP-2 activation coincided with up-regulated cellular levels of both membrane type 1-matrix metalloproteinase (MT1-MMP) and TIMP-2. A fraction of cellular membrane prepared from cells embedded in the collagen lattice containing active MT1-MMP and TIMP-2 was capable of activating pro-MMP-2, and exogenous TIMP-2 had a biphasic effect on this membrane-mediated MMP-2 activation. Interestingly, the presence of 43-kDa MT1-MMP species in a fraction of intracellular soluble proteins prepared from monolayer cells but not cells embedded in the lattices indicates that MT1-MMP metabolizes differently under the two different culture conditions. Treatment of cells embedded in the lattice with furin inhibitor attenuated pro-MT1-MMP processing and MMP-2 activation and impeded cell migration and invasion. These results suggest that the migration and invasion of cardiac fibroblasts is furin-dependent and that the active species of MT1-MMP and MMP-2 may be involved in both events.
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, De Montfort University, Leicester LE1 9BH, United Kingdom. chun.guo@man.ac.uk
authors.forename: Chun
authors.initials: C
authors.lastname: Guo
authors.forename: Lucia
authors.initials: L
authors.lastname: Piacentini
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002465:Cell Movement; D002478:Cells, Cultured; D024042:Collagen Type I / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000201:enzymology*; D045683:Furin / Q000502:physiology; D006352:Heart Ventricles / Q000166:cytology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000096:biosynthesis*; D015854:Up-Regulation
chemical_list: D024042:Collagen Type I; D019716:Tissue Inhibitor of Metalloproteinase-2; D045683:Furin; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2