Collagen denaturation in the infarcted myocardium involves temporally distinct effects of MT1-MMP-dependent proteolysis and mechanical tension

•In healing infarcts, collagen denaturation exhibits two distinct phases, an early pericellular, and late generalized phase.•Early denaturation reflects membrane type 1- Matrix Metalloproteinase (MT1-MMP)-induced proteolysis and cell migration.•MT1-MMP-mediated collagen denaturation and fibroblast migration involve the catalytic site and the hemopexin domain.•Mechanical tension may be responsible for MT1-MMP-independent collagen denaturation during the infarct maturation phase.•Chronic denaturation may increase matrix susceptibility to proteolysis, contributing to progressive cardiac failure.