#4425 EZH2 PROMOTES RENAL INTERSTITIAL FIBROSIS THROUGH DOWNREGULATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE 1 MEDIATED GLUCONEOGENESIS

Abstract

Abstract Background and Aims Renal fibrosis is the common pathological pathway of various chronic kidney diseases progressing to the end stage of renal failure. The methyltransferase enhancer of zeste homolog 2 (EZH2) has been identified as a therapeutic target to inhibit renal interstitial fibrosis. However, the mechanism underlying the role of EZH2 in renal fibrosis is not completely understood. Method Unilateral ureteral obstruction (UUO), unilateral ischemia-reperfusion injury (UIRI) mouse models were established. PCR, cleavage under targets and tagmentation (CUT&Tag) and Western blotting was performed to evaluate the expression of EZH2 and phosphoenolpyruvate carboxykinase 1 (PCK1). Results By using EZH2 inhibitor 3-DZNeP and Ezh2 conditional knockout mice, we confirmed the pro-fibrotic effect of EZH2 in unilateral ureteral obstruction (UUO). Through RNA sequence and cleavage under targets and tagmentation (CUT&Tag) sequence analysis, we found that the phosphoenolpyruvate carboxykinase 1 (PCK1), a critical enzyme in gluconeogenesis, is negatively regulated by EZH2 in fibrotic kidneys, which was further confirmed by quantitative PCR, CUT&Tag and Western blotting. We further showed that deletion or inhibition of EZH2 inhibited renal fibrosis and enhanced PCK1 expression and activity in unilateral ischemia-reperfusion injury (UIRI) and folic acid induced mouse nephropathy. Moreover, the dysregulated production of renal glucose and lactate in mouse UUO kidneys was restored after EZH2 inhibition by 3-DZNeP. Finally, inhibition of PCK1 by 3-mercaptopropionic acid (3-MPA) abrogated the anti-fibrotic effect of 3-DZNeP in UUO kidneys. Conclusion We conclude that EZH2 promotes renal interstitial fibrosis through inhibition of PCK1 mediated gluconeogenesis.