Transcriptomics of mouse bone marrow erythropoiesis

Metabolic requirements vary during tissue development, but little is known whether and how metabolic rewiring orchestrates lineage differentiation and maturation. We discovered an essential metabolic switch from glutamine catabolism to glutamine synthesis during erythropoiesis. Glutamine synthetase (GS), one of the oldest functioning genes, is induced during terminal maturation to promote detoxification of ammonia generated during heme biosynthesis, which is massively upregulated to support hemoglobin production. Loss of GS in mouse erythroid precursors causes ammonia accumulation, oxidative stress, leading to maturation arrest and apoptosis. In β-thalassemia, GS activity is impaired by protein oxidation, causing glutamate and ammonia accumulation, whereas enforced GS expression alleviates the metabolic and pathologic defects. These results identify an evolutionarily conserved metabolic adaptation that may be leveraged to treat common red cell disorders.