FIG. 1.

Prx2^−/− mice show ineffective erythropoiesis similar to β-thalassemia (Hbb^th3/+ mice). (A) Left panel. Morphology of sorted erythroid from WT, Prx2^−/− and Hbb^th3/+ mice. Cytospins were stained with May-Grunwald-Giemsa. Cells were imaged under oil at 100×magnification using a Panfluor objective with 1.30 numeric aperture on a Nikon Eclipse DS-5M camera and processed with Digital Slide (DS-L1) Nikon. One representative image from a total of 10 for each mouse strains. Right panel. Abnormal nuclear-shaped erythroblasts and binuclear erythroblasts from WT, Prx2^−/−, and Hbb^th3/+ mice evaluated on cytospin stained with May-Grunwald-Giemsa. Data are presented as means±SD (n=10 from each strain); *p<0.05 compared with WT. (B) Cyto-fluorimetric analysis of maturation pattern of erythroid precursors from the bone marrow (upper panel) and spleen (lower panel) of WT Prx2^−/− and Hbb^th3/+ mice using the following surface markers: CD44 and TER119 (see Supplementary Materials and Methods and Supplementary Fig. S1A). This cyto-fluorimetric strategy allows the identification of the following homogenous cell populations: population I corresponding to pro-erythroblasts; population II corresponding to basophilic erythroblasts; population III corresponding to polychromatic erythroblasts; and population IV corresponding to orthochromatic erythroblasts. Data are presented as means±SD (n=12); *p<0.05 compared with WT. (C) ROS levels in erythroid precursors from bone marrow (left panel) and spleen (right panel) of WT, Prx2^−/−, and Hbb^th3/+ mice. Data are presented as means±SD (n=12 from each strain); *p<0.05 compared with WT; °p<0.05 compared with Prx2^−/−. (D) Amount of Annexin V⁺-7-AAD⁻ cells (early apoptosis) on sorted orthochromatic erythroblasts (population IV) from either bone marrow of WT, Prx2^−/−, and Hbb^th3/+mice or spleen of Prx2^−/− and Hbb^th3/+mice. Data are presented as means±SD (n=8 from each strain); *p<0.05 compared with WT; °p<0.05 compared with Prx2^−/− mice. 7-AAD, 7-aminoactinomycin D; Prx2, peroxiredoxin-2; ROS, reactive oxygen species; SD, standard deviation; WT, wild type. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars