FIG. 4.

The absence of Prx2 worsens β-thalassemic ineffective erythropoiesis, with increased ROS levels and cell apoptosis in Prx2^−/−Hbb^th3/+ mice. (A) Left panel. Morphology of sorted erythroid from Hbb^th3/+ and Prx2^−/− 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 strain. Right panel. Abnormal nuclear-shaped erythroblasts and binuclear erythroblasts from Hbb^th3/+ and Prx2^−/− 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. (B) Cyto-fluorimetric analysis of maturation pattern of erythroid precursors from the bone marrow (upper panel) and spleen (lower panel) of Hbb^th3/+ and Prx2^−/− Hbb^th3/+ mice using the following surface markers: CD44 and TER119. Population I corresponds to pro-erythroblasts; population II corresponds to basophilic erythroblasts; population III corresponds to polychromatic erythroblasts; and population IV corresponds to orthochromatic erythroblasts. Data are presented as means±SD (n=10); *p<0.05 compared with Hbb^th3/+. (C) ROS levels from erythroid precursors from the bone marrow (left panel) and spleen (right panel) of Hbb^th3/+ and Prx2^−/− Hbb^th3/+ mice using the following surface markers: CD44 and TER119 (see Supplementary Materials and Methods). Data are presented as means±SD (n=10 from each strain); *p<0.05 compared with Hbb^th3/+ mice. (D) Amount of Annexin-V⁺-7-AAD⁻ cells (early apoptosis) in sorted orthochromatic erythroblasts (population IV) from either bone marrow of Hbb^th3/+ and Prx2^−/− Hbb^th3/+ mice or spleen of Hbb^th3/+ and Prx2^−/− Hbb^th3/+ mice. Data are presented as means±SD (n=10 from each strain); *p<0.05 compared with Hbb^th3/+ mice. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars