[Dynamic Changes of ROS and Nrf2-Related Factors During Erythroid Development]

To investigate the changes and roles of reactive oxygen species (ROS) and nuclear factor erythroid 2-related factor 2 (Nrf2) related antioxidases during erythroid development.

Flow cytometry was used to detect the sensibility of peripheral red blood cells of wild-type mice to a strong oxidant hydrogen peroxide (H₂O₂). Erythroid cells from different developmental stages in bone marrow (BM) were obtained using fluorescence-activated cell sorter and the ROS levels were detected by flow cytometry. RT-qPCR was used to detect the changes of expression levels of Nrf2 and related antioxidases in erythroid cells from different developmental stages in BM. The ROS levels of the peripheral blood and BM nucleated erythrocytes in Nrf2 knockout mice were further examined. The expression level of Nrf2 in erythroid precursors isolated from 14.5 d embryonic liver of wild-type mice during differentiation and culture in vitro was detected.

In the peripheral blood of wild-type mice, the ROS level of reticulocytes and mature erythrocytes treated with H₂O₂ increased about 4 times and 7 times, respectively (P<0.01). In BM erythrocytes, the ROS level gradually decreased as the cells matured (r=0.85), while the expression level of Nrf2 and its related anti-oxidative genes increased (r=0.99). The ROS levels in peripheral blood erythrocytes and BM nucleated erythrocytes of Nrf2 knockout mice were significantly increased compared with wild-type mice (P<0.01). The expression of Nrf2 increased during the early erythroid development after embryonic liver cell sorting (P<0.01).

The expression levels of Nrf2 and its related factors vary during erythropoiesis. Nrf2 at physiological level plays an important antioxidant role during the erythroid development.