雌激素诱导小鼠胸腺萎缩过程中细胞因子及凋亡相关蛋白基因表达的变化

The Changes of Cytokine and Apoptosis-associated Protein Gene Expression during Estrogen-induced Thymus Atrophy in Mouse

本试验应用光镜、电镜、流式细胞术、实时定量PCR技术研究了雌激素诱导小鼠胸腺萎缩过程中胸腺指数、胸腺显微和超微结构、胸腺细胞凋亡率及部分细胞因子和凋亡相关蛋白基因表达的变化。结果注射雌激素后,小鼠胸腺指数显著下降,胸腺中凋亡细胞数量显著上升,细胞因子TGF-β1表达量显著升高,IL-6表达量略为升高,而IL-7表达量显著降低;凋亡相关蛋白Caspase-3、Caspase-9、FADD表达量显著上升,FasL表达量略有上升,而Bcl-2表达量显著降低。表明雌激素可能一方面通过调节胸腺细胞因子抑制胸腺上皮细胞的增殖,另一方面通过激活Caspase级联程序的启动和执行阶段及Fas/FasL凋亡信号通路促进胸腺细胞的凋亡,从而诱导小鼠胸腺萎缩。

The thymus index,microstructure,ultrastructure,thymocyte apoptosis ratio and the expression of several thymic cytokines and apoptosis-associated protein genes of mouse thymus were studied by using light microscope,electron micros-copy,flow cytometry,and real-time PCR technique during estrogen-induced thymus atrophy in mouse.The results indicated that in estrogen administration mouse,the thymus index decreased greatly,whereas the thymocyte apoptosis ratio increased signally;the expression level of thymic cytokines TGF-β1 increased greatly,IL-6 increased slightly,while IL-7 decreased obviously;the expression level of apoptosis-associated protein genes Caspase-3,Caspase-9 and FADD increased significantly,FasL increased slightly,while Bcl-2 decreased greatly.The results revealed that thymus atrophy in mouse was induced by estrogen possibly through inhibiting thymic epithelial cell proliferation by regulating the thymic cytokines on the one hand,and promoting thymocyte apoptosis by activting the initiatory and executive stages of Caspase cascade and the Fas/FasL-mediated apoptosis on the other hand.