OGT-mediated O-GlcNAc of FOXO1 promotes the progression of neonatal heart failure via regulating pyroptosis.

Neonatal heart failure (HF) is a progressive disease caused by cardiovascular and non-cardiovascular abnormalities. O-linked beta-N-acetylglucosamine (O-GlcNAc), a dynamic post-translational modification, is rapidly cycled on and off proteins by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. This study aimed to investigate the role of O-GlcNAc in neonatal HF and the underlying mechanism. Twenty-eight neonatal HF patients and 22 healthy control volunteers were included. In vivo and in vitro HF models were established. Western blotting and RT-qPCR were used to detect the expression of O-GlcNAc, OGT, OGA, and pyroptosis-related indicators. CCK-8 was used to detect the cell viability. Lactate dehydrogenase and propidium iodide staining commercial kits were used to assess the cytotoxicity and apoptosis. The concentrations of interleukin (IL)-1β and IL-18 were analyzed by ELISA. Co-immunoprecipitation was performed to verify the interaction between OGT and forkhead box O1 (FOXO1). Results showed that OGT-mediated O-GlcNAc was elevated in HF. Besides, OGT deficiency suppressed pyroptosis in Angiotensin (Ang)II-treated H9c2 cells. Mechanically, OGT regulated the O-GlcNAc of FOXO1 at S41 site in H9c2 cells. Subsequent rescue experiments indicated that FOXO1 overexpression promoted pyroptosis in AngII-treated H9c2 cells. Final animal studies illustrated that OGT inhibition alleviated myocardial tissue necrosis, myocardial fibrosis, and pathological cardiac dysfunction. In conclusion, OGT-mediated O-GlcNAc of FOXO1 promoted the progression of neonatal HF via regulating pyroptosis, which might provide a new insight for neonatal HF treatment.