放射线对小鼠T细胞分化相关蛋白T-bet、GATA-3、RORγt、Foxp 3表达的影响

Effects of γ-ray Radiation on the Expression of T Cell Differentiation Associated Proteins T-bet、GATA-3、RORγt、Foxp3 of Mouse Spleen

目的:观察放射线对小鼠脾脏T细胞分化特异性转录因子T-bet、GATA-3、RORγt、Foxp3蛋白表达水平的影60响。方法:Coγ射线(1.0 Gy,5.5 min)照射Balb/c小鼠,分别于照射后第4、8、12及20天检测小鼠外周血象;骨髓病理切片观察骨髓造血组织增生情况;Western Blot法检测脾脏T细胞分化特异性转录因子T-bet、GATA-3、RORγt、Foxp 3蛋白表达水平。结果:γ射线照射后小鼠外周血白细胞和血小板数量显著降低;骨髓造血细胞显著减少,脂肪细胞明显增多;放射线照射Balb/c小鼠,脾脏GATA-3、RORγt、Foxp 3蛋白表达下降,于照射后第4天表达水平最低,之后逐渐升高但低于正常对照组水平(P<0.05);脾脏T-bet蛋白表达水平明显高于对照组水平(P<0.05);T-bet/GATA3、RORγt/Foxp3比值明显增大(P<0.05),于照射后第4天比值最大。结论:放射线抑制Balb/c小鼠骨髓造血,同时导致脾脏T细胞分化异常;骨髓造血功能低下可能与T细胞分化异常相关。

Objective To investigate the effects ofγ-ray radiation on the expression of T cell differentiation associated specific transcription factors T-bet, GATA-3, RORγt and Foxp3 which specifically expressed in helper T cell subsets： Thl, Th2, Thl7 and Treg cells. Methods Experimental mice were randomly divided into two groups： the control group was received sham radiation and the radiation group was given 5.5 minutes radiation of 1.0 Gy total body 60Coγ-ray. The mice in radiation group were respectively killed at 4, 8, 12, 20 days after radiation, and those in control group were killed at the 20th day. The white blood cells and platelels were counted. The hematopoietic cells of bone marrow were observed by biopsy sections. The expression levels of T-bet, GATA-3, RORγt and Foxp3 proteins in spleen tissue were detected by Western Blot. Results Compared with the control group, the white blood cells and platelets of radiation group were reduced obviously; BM biopsy sections showed that the hematopoietic cells were decreased and adipocytes were increased significantly. The expression level of T-bet was increased significantly （ P〈0.05 ） ; But the expression levels of GATA-3, RORγt and Foxp3 proteins were notably decreased （P〈0.05） which reached its lowest level at 4th day. At 8th, 12th, 15th day, the expression levels of GATA-3, RORγt and Foxp3 were gradually increased but still lower than those of the control group. The ratios of T-bet/GATA3 and RORγt/Foxp3 were obviously increased （P〈 0.05）. Conclusion Radiation could inhibit bone marrow hematopoiesis of Balb/c mice and induce the abnormal differentiation of T cell which might be associated with bone marrow hematopoiesis obstacle.