etc-1002 and Non-alcoholic-Fatty-Liver-Disease

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent progressive condition that lacks a specific pharmacological treatment. ATP-citrate lyase (ACLY) is one of the emergent targets for the treatment of NAFLD. This review aims to summarize the role of ACLY in NAFLD, provide evidence of the beneficial effects of the ACLY inhibitor bempedoic acid (BemA) in NAFLD and discuss the mechanisms involved.. BemA is effective in reducing hepatic steatosis in several animal models that recapitulate different stages of the disease. Thus, in a dietary model of simple hepatic steatosis in female rats, BemA abrogates the accumulation of liver fat. Apart from ACLY inhibition, BemA has several functions in the liver that contribute to the antisteatotic effect: inhibition of ketohexokinase, induction of patatin-like phospholipase domain-containing protein 3 and increases in both fatty acid β-oxidation activity and hepatic H 2 S production. In models of the advanced phases of NAFLD, BemA reduces not only steatosis, but also ballooning, lobular inflammation and hepatic fibrosis, by mechanisms involving both hepatocytes and hepatic stellate cells.. BemA, an ACLY inhibitor currently approved for the treatment of hypercholesterolemia, may be a useful drug to treat NAFLD through its antisteatotic, anti-inflammatory and antifibrotic effects.

Topics: Animals; Dicarboxylic Acids; Fatty Acids; Female; Liver; Non-alcoholic Fatty Liver Disease; Rats

The hepatic SLC13A5/SLC25A1-ATP-dependent citrate lyase (ACLY) signaling pathway, responsible for maintaining the citrate homeostasis, plays a crucial role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Bempedoic acid (BA), an ACLY inhibitor commonly used for managing hypercholesterolemia, has shown promising results in addressing hepatic steatosis. This study aimed to elucidate the intricate relationships in processes of hepatic lipogenesis among SLC13A5, SLC25A1, and ACLY and to examine the therapeutic potential of BA in NAFLD, providing insights into its underlying mechanism. In murine primary hepatocytes and HepG2 cells, the silencing or pharmacological inhibition of SLC25A1/ACLY resulted in significant upregulation of SLC13A5 transcription and activity. This increase in SLC13A5 activity subsequently led to enhanced lipogenesis, indicating a compensatory role of SLC13A5 when the SLC25A1/ACLY pathway was inhibited. However, BA effectively counteracted this upregulation, reduced lipid accumulation, and ameliorated various biomarkers of NAFLD. The disease-modifying effects of BA were further confirmed in NAFLD mice. Mechanistic investigations revealed that BA could reverse the elevated transcription levels of SLC13A5 and ACLY, and the subsequent lipogenesis induced by PXR activation in vitro and in vivo. Importantly, this effect was diminished when PXR was knocked down, suggesting the involvement of the hepatic PXR-SLC13A5/ACLY signaling axis in the mechanism of BA action. In conclusion, SLC13A5-mediated extracellular citrate influx emerges as an alternative pathway to SLC25A1/ACLY in the regulation of lipogenesis in hepatocytes, BA exhibits therapeutic potential in NAFLD by suppressing the hepatic PXR-SLC13A5/ACLY signaling axis, while PXR, a key regulator in drug metabolism may be involved in the pathogenesis of NAFLD. SIGNIFICANCE STATEMENT: This work describes that bempedoic acid, an ATP-dependent citrate lyase (ACLY) inhibitor, ameliorates hepatic lipid accumulation and various hallmarks of non-alcoholic fatty liver disease. Suppression of hepatic SLC25A1-ACLY pathway upregulates SLC13A5 transcription, which in turn activates extracellular citrate influx and the subsequent DNL. Whereas in hepatocytes or the liver tissue challenged with high energy intake, bempedoic acid reverses compensatory activation of SLC13A5 via modulating the hepatic PXR-SLC13A5/ACLY axis, thereby simultaneously downregulating SLC13A5 and ACLY.

Topics: Animals; ATP Citrate (pro-S)-Lyase; Citrates; Citric Acid; Fatty Acids; Liver; Mice; Non-alcoholic Fatty Liver Disease; Signal Transduction