Mitoquinol improves phagocytosis and glycolysis in ethanol-exposed macrophages via HIF-1α-PFKP axis

Abstract

Alcohol use disorder increases sepsis mortality. Acute ethanol exposure impairs pathogen clearance in the macrophages via dampened glycolysis and phagocytosis, exaggerates oxidative stress, and regulates the function of the hypoxia-regulating factor 1α (HIF-1α), a master regulator of glycolysis. Decreased expression of the platelet isoform of phosphofructokinase (PFKP), a key glycolytic enzyme, in ethanol-exposed macrophages, is reported. However, transcriptional regulation of PFKP with ethanol exposure is unclear. We hypothesized that acute ethanol exposure–induced oxidative stress dampens macrophage phagocytosis and glycolysis via the HIF-1α-PFKP axis. In ethanol-exposed mouse bone marrow–derived macrophages with lipopolysaccharide stimulation, we studied (i) reactive oxygen species (ROS), phagocytosis, glycolysis, PFKP, and HIF-1α expressions ± ethanol exposure; (ii) the role of HIF-1α in transcriptionally controlling PFKP messenger RNA by chromatin immunoprecipitation–quantitative polymerase chain reaction technique; and (iii) the effect of mitoquinol (MitoQ), a mitochondria-specific antioxidant, on HIF-1α function, glycolysis, phagocytosis, and pathogen clearance in ethanol-exposed macrophages. Last, we examined the effect of MitoQ on 7-d survival in alcohol vs. vehicle-drinking mice with cecal slurry–induced sepsis. In ethanol-exposed and lipopolysaccharide–stimulated macrophages, we found that (i) excessive total and mitochondrial ROS production and dampened phagocytosis, glycolysis, and PFKP expression; (ii) dysfunctional HIF-1α downregulates PFKP transcription; (iii) MitoQ restrains ROS production, restores HIF-1α function, and improves glycolysis and phagocytosis via preserved PFKP messenger RNA and protein expression; and (iv) MitoQ treatment improves survival and pathogen clearance in ethanol with sepsis mice. In conclusion, we found that the HIF-1α-PFKP axis regulates glycolysis and phagocytosis in ethanol-exposed macrophages and is a potential therapeutic target in ethanol with sepsis.