[Influence of HIF- 2α on the expression of GATA- 1 in bone marrow CD71(+) cell of high altitude polycythemia rat model].

Objective To explore the influence of hypoxia-inducible factor-2 αlpha (HIF-2α) on the expression of erythroid-specific transcription factor GATA-1 in bone marrow CD71+ cells of rat model with high altitude polycythemia (HAPC). Methods A total of 48 male SD rats were selected and randomly divided into normal control group and HAPC group. HAPC model was established at an altitude of 4 300 meters in the natural environment and verified by bone marrow cell classification and counting, hematologic parameters and serum EPO detection. Bone marrow CD71 + cells were separated by a combination of methods with density gradient centrifugation and magnetic activated cell sorting. The changes of expression level of HIF-2α, GATA-1 mRNA and proteins were detected by Q-PCR and Western blot. CD71 + cells were cultured under hypoxia condition and transfected with selected optimal HIF- 2α shRNAi3 for 96 h. And the expression level of HIF-2α and GATA-1 mRNA and proteins were detected by Q- PCR and Western blot. Results The results of bone marrow cell counts, the hematologic parameters and the serum EPO content showed that the HAPC rat model was successfully established. The expression of HIF-2α and GATA-1 mRNA and protein in bone marrow CD71+ cells of HAPC group was higher than that in control group (P<0.05). And HIF-2α and GATA-1 of HAPC group were positively correlated at the expression levels of mRNA and protein, respectively (r=0.923, P<0.01; r=0.838, P<0.01). However, the expression of HIF-2α and GATA-1 mRNA and protein in HAPC group was significantly lower than that in control groups after interfered by HIF-2α shRNAi3 for 96 h (P<0.05). Conclusion The effect of HIF-2α on GATA-1 expression may be correlated with the pathogenesis of HAPC. Key words: High altitude polycythemia; Hypoxia-inducible factor-2 αlpha; GATA-1; Small interfering RNA