SMAD3 and Hypertension: In addition, Wei et al. found that naringenin, as a Smad3-specific inhibitor, could attenuate hypertension-induced atrial fibrosis in spontaneously hypertensive rats (SHRs) and inhibit the proliferation and ECM protein expression of CFs induced by elevated hydrostatic pressure via the suppression of Smad3 signaling activation [7].