Improvement of MASLD and MASH by suppression of hepatic N-Acetyltransferase 10 (RIP-Seq)
Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are still needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA stability post-transcriptionally. N-acetyltransferase 10 (NAT10), the sole enzyme catalyzing mRNA acetylation, has not been fully explored in human diseases, especially in MASLD and MASH. In the current study, abundant RNA acetylation was found in lipid metabolism-related genes in the livers of leptin receptor-deficient (db/db) mice. Besides, hepatic NAT10 expression is significantly increased in multiple mouse models of MASLD and MASH. NAT10 expression is also elevated in patients with MASLD and positively correlated with clinical characteristics. Genetic NAT10 knockdown protects against diet-induced hepatic steatosis and steatohepatitis in mice, while its overexpression exacerbates steatosis. Mechanistically, NAT10 could bind to Srebp-1c mRNA to promote its stability and expression, thereby upregulating lipogenic enzymes. In addition, the translational significance of our findings is that treatment of Remodelin, an NAT10 inhibitor, could improve liver steatosis and dyslipidemia in a preclinical mouse model. Together, these findings highlight the significance of ac4C modification and NAT10 in MASLD and MASH, offering a potential therapeutic target for disease treatment. Overall design: RNA immunoprecipitation sequencing (RIP-Seq)  for mice injected with AAV-GFP/AAV-NAT10.