Altered Erythropoiesis in Mouse Models of Type 3 Hemochromatosis

Figure 6

Model depicting the involvement of iron and Tfr2 isoforms in erythropoiesis. (a) In young (14 d) WT mice, erythropoiesis takes place in both bone marrow (BM) and spleen while in adult animals, BM erythropoiesis is predominant as compared to splenic RBC production (blue arrows); (b) in the presence of normal circulating iron levels, lack of Tfr2β provokes iron retention in macrophages that causes immature splenic erythropoiesis and Erythroferrone (Erfe) increase in young mice, that generally have a high iron requirement. This is normalized in adult animals, although an increased amount of iron is retained in the spleen; (c) the same should be observed in the spleen of Tfr2 KO animals, but they have sufficient circulating iron amount to normalize splenic erythropoiesis (Erfe is decreased). High iron availability also causes an increase of the early stage of BM erythropoiesis in adult mice, that does not result in reticulocytosis because of increased apoptosis.

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