Matrix metalloproteinase-9 induces cardiac fibroblast migration, collagen and cytokine secretion: Inhibition by salvianolic acid B from Salvia miltiorrhiza

Abstract

Cardiac fibroblasts play the key role in cardiac function and matrix metalloproteinases-9 (MMP-9) is a well known contributor to the development of myocardial remodeling. However, the direct regulation of MMP-9 on the function of cardiac fibroblasts and the underlying mechanism are far from elucidation. In the present research, recombinant protein encoding catalytic domain of MMP-9 (MMP-9 CD) was constructed and the function of neonatal cardiac fibroblasts was investigated by cell proliferation assay, migration assay, picrosirius red assay, multiplex cytokine assay and fibroblast phenotype detection. 200 nM MMP-9 CD stimulated cardiac fibroblasts migration (169.4 ± 22.5% versus 100 ± 0%, p < 0.01), increased collagen synthesis (1.5 ± 0.2 fold, p < 0.05), up-regulated the secretion of ICAM (574.0 ± 40.1 versus 268.5 ± 8.6 pg/ml, p < 0.01), TNF-α (192.6 ± 11.0 versus 14.4 ± 1.8 pg/ml, p < 0.001), IL-6 (1500.9 ± 70.2 versus 323.4 ± 40.6 pg/ml, p < 0.001) and sVCAM-1 (30.3 ± 4.3 versus 7.0 ± 0.1 pg/ml, p < 0.05) and down-regulated VEGF (436.5 ± 148.9 versus 1034.3 ± 28.1 pg/ml, p < 0.05) significantly with modest effects on proliferation. Accompanying with these regulations, transition of fibroblasts to myofibroblast was confirmed by immunofluorescent stain of α-smooth muscle actin (α-SMA) with MMP-9 CD treatment. Furthermore, salvianolic acid B (SalB) inhibited the effects of MMP-9 CD significantly. In conclusion, our results provide evidence for a direct influence of MMP-9 on cardiac fibroblast migration, collagen and cytokine secretion, which can be attenuated by SalB.