Cytokines regulate matrix metalloproteinases and migration in cardiac fibroblasts

We sought to define the relationship between cytokine stimulated release of matrix metalloproteinases (MMPs) and cell migration using adult rat cardiac fibroblasts. Interleukin-1β (IL-1β) increased release of MMP-2, -3, and -9, and TIMP-1, by 3–6-fold, measured by immunoblotting and gel zymography. Tumor necrosis factor-α (TNFα) augmented IL-1β stimulated release of MMP-9, but not MMP-2 or -3. Transforming growth factor-β1 (TGFβ1) attenuated all the responses to IL-1β. IL-1β was also the most robust stimulus of adult rat cardiac fibroblast migration, measured in Boyden chamber assays. The combination of IL-1β plus TNFα substantially enhanced migration, whereas TGFβ1 strongly inhibited the migratory response to IL-1β. The pan-selective MMP inhibitor GM 6001 effectively blocked IL-1β stimulated migration. Pharmacologic inhibitors selective for ERK, JNK, and p38 MAP kinase pathways inhibited the IL-1β regulation of individual MMPs. Increased MMP activity associated with migration of cardiac fibroblasts may be important determinants of cytokine-directed remodeling of injured myocardium.