查看文章

In the setting of myocardial infarction, matrix metalloproteinase-9 (MMP-9) deletion reduces macrophage infiltration into the left ventricle (LV) and attenuates LV remodeling. We recently showed that LV MMP-9 levels increase with age, and MMP-9 deletion attenuates cardiac aging by modifying the extracellular matrix response to prevent diastolic dysfunction. However, the effects of MMP-9 deletion on the inflammatory component of cardiac aging have not been investigated. We evaluated wild-type (WT) and MMP-9 null mice of four age groups: young (6-9 months), middle aged (12-15 months), old (18-24 months), and senescent (> 25 months). Biclustering analysis for 84 inflammatory genes revealed a unique aging inflammatory pattern. With age, the WT LV showed no significant changes in expression of macrophage M1 markers but did show decreases in M2 marker expression. In contrast, MMP-9 deletion …