Targeting HMGCS2: Ketogenesis Suppression Accelerates NAFLD Progression in T2DM Comorbidity, While Cynaroside Ameliorates NASH in Concomitant T2DM

Patients with concurrent non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) exhibit increased susceptibility to non-alcoholic steatohepatitis (NASH), advanced hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. This study investigated the contribution of ketogenesis to T2DM-mediated NAFLD exacerbation and elucidated the therapeutic mechanism of cynaroside in NASH-complicated T2DM. Male C57BL/6J mice were given CDAHFD combined with streptozotocin to establish stage-specific NAFLD with T2DM models. Hepatic HMGCS2 expression was modulated via tail vein injection of adenoviral vectors for HMGCS2 overexpression or knockdown. Cynaroside was administered orally from week 5 to week 8. The results showed that concurrent T2DM accelerated NAFLD progression, accompanied by a dysregulated ketogenesis that was correlated with disease severity. Hepatic HMGCS2 expression paralleled circulating ketone body concentrations, indicating that HMGCS2-mediated ketogenic dysregulation contributed to NAFLD pathogenesis in T2DM contexts. HMGCS2 overexpression in NASH-T2DM models significantly attenuated steatohepatitis progression through the enhancement of ketogenesis. Cynaroside administration ameliorated hepatic pathology in NASH-T2DM mice by (1) reducing hepatocellular injury and lobular inflammation; (2) decreasing intrahepatic lipid accumulation; and (3) suppressing hepatocyte senescence and the secretion of SASP factors. Mechanistically, cynaroside exerted therapeutic effects via HMGCS2-mediated ketogenesis. Our data demonstrated that ketogenic modulation is a viable therapeutic strategy to delay T2DM-NAFLD progression.