HIF-1α drives distinct aspects of hypoxia-induced glucose metabolism in intestinal epithelial cells

The hypoxia-inducible factor-1α (HIF-1α) has canonically been described as a primary regulator of glucose metabolism in hypoxic cells through transcriptional upregulation of all 10 glycolytic enzymes. Here, using ¹³C-glucose and ¹³C-glutamine tracing in intestinal epithelial cells with defined HIF1A genetic perturbations, we demonstrate that hypoxia-induced glycolysis can occur independently of HIF-1-driven transcription. While hypoxia modulates glucose-derived carbon flux into anabolic branches of glycolysis independent of HIF-1α, HIF-1α plays an important role in modulating glucose and glutamine utilization within the tricarboxylic acid cycle. These alterations in substrate utilization highlight the layered regulatory framework whereby HIF-1α regulates distinct aspects of glucose and glutamine metabolism in intestinal epithelial cells to impact the rate of intestinal epithelial cell growth and promote metabolic adaptation to hypoxia.