Bempedoic acid suppresses diet-induced hepatic steatosis independently of ATP-citrate lyase

Abstract

ATP citrate lyase (ACLY) synthesizes acetyl-CoA for de novo lipogenesis (DNL), which is elevated in metabolic dysfunction-associated steatotic liver disease. Hepatic ACLY is inhibited by the LDL-cholesterol-lowering drug bempedoic acid (BPA), which also improves steatosis in mice. While BPA potently suppresses hepatic DNL and increases fat catabolism, it is unclear if ACLY is its primary molecular target in reducing liver triglyceride. We show that on a Western diet, loss of hepatic ACLY alone or together with the acetyl-CoA synthetase ACSS2 unexpectedly exacerbates steatosis, linked to reduced PPARα target gene expression and fatty acid oxidation. Importantly, BPA treatment ameliorates Western diet-mediated triacylglyceride accumulation in both WT and liver ACLY knockout mice, indicating that its primary effects on hepatic steatosis are ACLY independent. Together, these data indicate that hepatic ACLY plays an unexpected role in restraining diet-dependent lipid accumulation and that BPA exerts substantial effects on hepatic lipid metabolism independently of ACLY.