Matrix metalloproteinases as input and output signals for post-myocardial infarction remodeling

Despite current optimal therapeutic regimens, approximately one in four patients diagnosed with myocardial infarction (MI) will go on to develop congestive heart failure, and heart failure has a high five-year mortality rate of 50%. Elucidating mechanisms whereby heart failure develops post-MI, therefore, is highly needed. Matrix metalloproteinases (MMPs) are key enzymes involved in post-MI remodeling of the left ventricle (LV). While MMPs process cytokine and extracellular matrix (ECM) substrates to regulate the inflammatory and fibrotic components of the wound healing response to MI, MMPs also serve as upstream signaling initiators with direct actions on cell signaling cascades. In this review, we summarize the current literature regarding MMP roles in post-MI LV remodeling. We also identify the current knowledge gaps and provide templates for experiments to fill these gaps. A more complete understanding of MMP roles, particularly with regards to upstream signaling roles, may provide new strategies to limit adverse LV remodeling.