FIGURE 7.

HIF-2 is a central regulator of erythropoiesis. Following hemolysis, the kidney and intestine experience hypoxia due to poor oxygen delivery. In the kidney, HIF-2α is stabilized, allowing it to bind to and activate the Epo promoter. In the small intestine, HIF-2α activates the Dcytb and Dmt1 genes, increasing iron absorption. Increased levels of circulating EPO and iron stimulate erythropoiesis and supply new erythrocytes with iron for hemoglobin production. ARNT, aryl hydrocarbon receptor nuclear translocator.