KDM4A and Interstitial cardiac fibrosis: In this study, on the basis of confirming the profibrotic effect of premature senescent fibroblasts in the injured heart, we demonstrated that Kdm4a downregulation restrains excessive cardiac interstitial fibrosis and remodeling by depressing the premature senescence of fibroblasts in the advanced stage after MI, but does not affect the early ventricular rupture.