GCN5 drives MASLD progression through LXRα/SREBP1c signaling pathway-mediated de novo lipogenesis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global health concern that affects nearly one-quarter of the world's population. General control non-repressed protein 5 (GCN5), a histone acetyltransferase (HAT), has been implicated in the progression of several diseases, but its role in MASLD remains unclear. Here, we provide the experimental evidence that progressive human and male murine MASLD is driven by GCN5, but not by p300/CREB binding protein associated factor (PCAF) activation. Hepatocyte-specific GCN5 overexpression accelerates MASLD progression, whereas its ablation alleviates disease severity. Moreover, pharmacological inhibition of GCN5 with CPTH2 protects against MASLD. Metabolomics and RNA-seq analyses demonstrate that GCN5 promotes de novo lipogenesis (DNL) by upregulating SREBP1c-mediated transcription of lipogenic genes. Mechanistically, GCN5 acetylates histone H3 at the SREBP1c promoter, enhancing transcription through its intrinsic acetyltransferase activity. Our findings further identify GCN5 as a key regulator of LXRα-induced SREBP1c expression, suggesting that targeting GCN5 may selectively inhibit SREBP1c-driven DNL without impairing LXRα-mediated reverse cholesterol transport (RCT). Notably, combined treatment with the Liver X Receptor (LXR) agonist T0901317 and CPTH2 synergistically reduced lipid accumulation in vitro and in vivo, highlighting a promising therapeutic strategy for MASLD.