Iron repletion restores anemia and erythroid differentiation by attenuating HRI and mTORC1 signaling in iron-deficient mice. (A) RBC numbers and Hb levels in blood samples of iron-deficient (–FeR) and iron-replete (+FeR) mice. Mice were in ID for 16 to 20 weeks before FeR. (B) Representative Wright-Giemsa stained blood smears on day 0 and day 10 +FeR. Arrows indicate globin inclusions. (C) Representative histograms of ROS levels in reticulocytes of blood samples. (D) Spleen weights as percentage of body weight (BW). (E) Serum Epo levels. (F) Erythroid differentiation of BM and spleen samples. (G) Inactivation of HRI upon FeR in total spleen cells. (H) Downregulation of mTORC1 signaling upon FeR in spleen and blood cells. P values denote the difference between with and without FeR of each genotype. *P < .05, **P < .01, ***P < .001. Numbers of mice used: Wt–FeR, n = 3; Wt+FeR, n = 3; Hri^−/−–FeR, n = 4; Hri^−/−+FeR, n = 5; eAA–FeR, n = 5; eAA+FeR, n = 4; Atf4^−/−–FeR, n = 5; Atf4^−/−+FeR, n = 2.