The compendium of matrix metalloproteinase expression in the left ventricle of mice following myocardial infarction.

Matrix metalloproteinases (MMPs) are proteolytic enzymes that break down extracellular matrix (ECM) components and have shown to be highly active in the myocardial infarction (MI) landscape. In addition to breaking down ECM products, MMPs modulate cytokine signaling and mediate leukocyte cell physiology. MMP-2, -7, -8, -9, -12, -14, and -28 are well studied as effectors of cardiac remodeling after MI. Whereas 13 MMPs have been evaluated in the MI setting, 13 MMPs have not been investigated during cardiac remodeling. Here, we measure the remaining MMPs across the MI time continuum to provide the full catalog of MMP expression in the left ventricle after MI in mice. We found that MMP-10, -11, -16, -24, -25, and -27 increase after MI, whereas MMP-15, -17, -19, -21, -23b, and -26 did not change with MI. For the MMPs increased with MI, the macrophage was the predominant cell source. This work provides targets for investigation to understand the full complement of specific MMP roles in cardiac remodeling.NEW & NOTEWORTHY To date, a number of matrix metalloproteinases (MMPs) have not been evaluated in the left ventricle after myocardial infarction (MI). This article supplies the missing knowledge to provide a complete MI MMP compendium.

Matrix metalloproteinase-12 as an endogenous resolution promoting factor following myocardial infarction.

Following myocardial infarction (MI), timely resolution of inflammation promotes wound healing and scar formation while limiting excessive tissue damage. Resolution promoting factors (RPFs) are agents that blunt leukocyte trafficking and inflammation, promote necrotic and apoptotic cell clearance, and stimulate scar formation. Previously identified RPFs include mediators derived from lipids (resolvins, lipoxins, protectins, and maresins), proteins (glucocorticoids, annexin A1, galectin 1, and melanocortins), or gases (CO, H2S, and NO). Matrix metalloproteinase-12 (MMP-12; macrophage elastase) has shown promising RPF qualities in a variety of disease states. We review here the evidence that MMP-12 may serve as a novel RPF with potential therapeutic efficacy in the setting of MI.