Glucose-6-Phosphate Dehydrogenase Deficiency Reprograms Macrophage Metabolism in Hyperlipidemia.

Macrophages regulate inflammatory responses in hyperlipidemia and dysmetabolic states while performing a critical homeostatic function by clearing damaged or senescent red blood cells (RBCs) through erythrophagocytosis. This process delivers heme and iron that must be detoxified and recycled through NADPH-dependent pathways. Glucose-6-phosphate dehydrogenase deficiency (G6PDd), affecting ~6% of the global population, limits NADPH generation and predisposes RBCs to oxidative damage and hemolysis. Whether G6PD deficiency alters macrophage metabolic responses to RBC clearance in hyperlipidemic environments remains unknown. Humanized mouse models expressing canonical (hG6PDND), African (hG6PDA-), or Mediterranean (hG6PDMed-) G6PD variants were exposed to Western diet-induced hyperlipidemia. RBCs, plasma, and splenic macrophages were analyzed using metabolomics, lipidomics/oxylipin profiling, and quantitative proteomics. Hyperlipidemia increased circulating lipid species and altered RBC metabolism, while G6PD deficiency selectively reduced pentose phosphate pathway intermediates. Plasma metabolomics revealed signatures consistent with increased hemolysis in hyperlipidemic G6PD-deficient mice. Splenic macrophages from G6PDd animals showed biochemical evidence of erythrophagocytosis, glutathione depletion, and remodeling of central carbon metabolism. Variant-specific alterations included increased glycolytic flux, disrupted TCA cycle activity, and elevated succinate/fumarate ratios consistent with mitochondrial dysfunction. Proteomics revealed extensive mitochondrial and proteasomal remodeling. G6PD deficiency and hyperlipidemia converge to reprogram macrophage metabolism through NADPH limitation, redox imbalance, and impaired handling of RBC-derived metabolites. These findings identify an NADPH-dependent metabolic vulnerability linking RBC fragility, erythrophagocytosis, and inflammatory macrophage reprogramming.