Supplementary Figures_Fainshtein.pdf

Excessive hepatic glucose production (HGP) driven by increased gluconeogenesis is a hallmark of type 2 diabetes, making its inhibition a crucial strategy for reducing hyperglycemia. Central to HGP regulation is the transcriptional co-activator PGC-1α, which promotes the expression of key gluconeogenic enzymes. The acetylation state of PGC-1α significantly influences its coactivating potential, with increased acetylation—whether induced genetically or chemically—shown to suppress its gluconeogenic activity and lower hyperglycemia. The delicate balance between specific acetyltransferases and deacetylases determines the acetylation status of PGC-1α and, consequently, its activity. While the role of sirtuin deacetylases in PGC-1α acetylation has been extensively studied, zinc-dependent histone deacetylases (HDACs) have received less attention in this context. In this study, we demonstrate that HDAC1 strongly deacetylates PGC-1α, enhancing its ability to coactivate the transcription factor HNF4α. Furthermore, we show that depleting Hdac1 in mouse primary hepatocytes and liver tissue reduces glucose production, consistent with decreased PGC-1α activity. While the HDAC family has been investigated for their contributions to metabolic homeostasis, our findings reveal a specific mechanistic pathway by which HDAC1 modulates glucose homeostasis.