HIF-2α对高原红细胞增多症模型大鼠骨髓CD71(+)细胞GATA-1表达的影响

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.