Hepatic steatosis aggravates atherosclerosis via small extracellular vesicle-mediated inhibition of cellular cholesterol efflux

Background & Aims: While it is recognized that non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD), how NAFLD affects the development and progression of CVD remains unclear and debatable. Hence, we aimed to determine the role of steatotic hepatocyte-derived small extracellular vesicles (sEVs) in foam cell formation and atherosclerosis progression. Methods: sEVs from steatotic hepatocytes were isolated and characterized. MicroRNA (miRNA) deep sequencing was utilized to identify functional miRNA in sEVs. Lastly, we conducted a cross-sectional study on patients with NAFLD to validate these findings. Results: Treatment of sEVs from steatotic hepatocytes promoted macrophage-derived foam cell formation and atherosclerosis progression via inhibition of ABCA1-mediated cholesterol efflux. Macrophage-specific deletion of Abca1 in ApoE-/-mice abolished the role of steatotic hepatocyte-derived sEVs in atherosclerosis progression. In addition, hepatocyte-specific deletion of Rab27a, which is the key GTPase regulating sEV release, significantly ameliorated high-fat, high-cholesterol diet-induced atherosclerosis progression in ApoE-/-mice. The miRNA deep sequencing results showed that miR-30a-3p was enriched in sEVs from steatotic hepatocytes. miR-30a-3p directly targeted the 3' untranslated region of ABCA1 to inhibit ABCA1 expression and cholesterol efflux. Treatment with antagomiR-30a-3p significantly attenuated atherosclerosis progression in high-fat, high cholesterol diet-fed ApoE-/-mice. Moreover, serum sEVs from patients with NAFLD and sEV-miR-30a-3p expression were associated with decreased cholesterol efflux levels in foam cells.Conclusion: Steatotic hepatocyte-derived sEVs promote foam cell formation and facilitate atherogenesis via the miR-30a-3p/ ABCA1 axis. Reducing sEV secretion by steatotic hepatocytes or targeting miR-30a-3p may be potential therapeutic approaches to slow the progression of NAFLD-driven atherosclerosis.(c) 2023 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.