Endothelial-to-mesenchymal transition (EndMT) has been shown to contribute to cardiac
fibrosis and
heart failure (HF). Recent studies have demonstrated that EndMT is regulated by autophagy, and we previously showed suppression of excessive autophagy and alleviation of cardiac
fibrosis in HF mice with inactivated
receptor for advanced glycation end products (RAGE). Thus, we investigated whether reduced cardiac
fibrosis due to RAGE knockout occurred by inhibiting EndMT mediated by excessive autophagy. We found a decrease in endothelial cells (CD31+/
VE-Cadherin+) and an increase in cells co-expressing CD31 and α-smooth muscle actin (α-SMA, myofibroblast marker) at 8 weeks in heart tissue of mice subjected to transverse aortic constriction (TAC), which implied EndMT. Knockout RAGE decreased EndMT accompanied by decreased expression of
autophagy-related proteins (LC3BII/I and
Beclin 1), and alleviated cardiac
fibrosis and improved cardiac function in TAC mice. Moreover,
3-methyladenine (3-MA) and
chloroquine (CQ), inhibitors of autophagy, attenuated EndMT, and cardiac
fibrosis in TAC mice. Importantly, EndMT induced by AGEs could be blocked by autophagy inhibitor in vivo and in vitro. These results suggested that AGEs/RAGE-autophagy-EndMT axis involved in the development of cardiac
fibrosis and knockout RAGE ameliorated cardiac
fibrosis through decreasing EndMT regulated by autophagy, which could be a promising therapeutic strategy for HF.