MMP9 and Myocardial fibrosis: Adding TGF-β1 or DMOG alone partly restored the expression of MMP2, MMP9 and collagen I. When TGF-β1 and DMOG were added together, the expression of MMP2, MMP9 and collagen I was further up-regulated, comparable with that before valsartan addition, indicating that both TGF-β1 and DMOG pathways participated in Ang II-mediated myocardial fibrosis, and suggesting the presence of synergistic effects.