Deregulated Iron Metabolism in Bone Marrow from Adenine-induced Mouse Model of Chronic Kidney Disease

Although the primary cause of anemia in chronic kidney disease (CKD) is lack of sufficient erythropoietin (EPO), other factors may be involved, including the deregulation of iron metabolism. To clarify the mechanism of deranged erythropoiesis in CKD, we evaluated bone marrow (BM) cells in adenine-induced CKD mice. They showed even higher EPO expression in the kidney. Hepatic hepcidin mRNA and plasma hepcidin and ferritin levels were increased. Flow cytometry revealed a decrease in the number of cells expressing transferrin receptor (TfR), or late erythroid progenitors in BM; these cells correspond to proerythroblasts, and basophilic and polychromatic erythroblasts. In CKD mice, levels of erythroferrone mRNA in BM and splenic cells were significantly decreased, and MafB protein levels in BM cells were significantly increased. These results suggest that, in BM, the decrease in TfR, which may be associated with increased MafB levels, and the decrease in erythroferrone increase hepatic hepcidin expression, which may perturb iron recycling and erythropoiesis.