Hexokinase 2-mediated metabolic stress and inflammation burden of liver macrophages via histone lactylation in MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by metabolic dysfunction and inflammation burden, involving a significant enhancement of cellular glycolytic activity. Here, we elucidate how a positive feedback loop in liver macrophages drives MASLD pathogenesis and demonstrate that disrupting this cycle mitigates metabolic stress and macrophage M1 activation during MASLD. We detect elevated expression of hexokinase 2 (HK2) and H3K18la in liver macrophages from patients with MASLD and MASLD mice. This lactate-dependent histone lactylation promotes glycolysis and liver macrophage M1 polarization by enriching the promoters of glycolytic genes and activating transcription. Ultimately, the HK2/glycolysis/H3K18la positive feedback loop exacerbates the vicious cycle of enhancing metabolic dysregulation and histone lactylation and the inflammatory phenotype of liver macrophages. Myeloid-specific deletion of Hk2 or pharmacological inhibition of the transcription factor HIF-1α significantly disrupts this deleterious cycle. Therefore, our study illustrates that targeting this amplified pathogenic loop may offer a promising therapeutic strategy for MASLD.