FAS和FASL基因在大鼠胸腺细胞凋亡时的表达及其意义

Expression of Fas and FASL gene in rats thymocyte apoptosis and its significance

目的检测FAS和FASL基因在Wistar大鼠胸腺细胞凋亡的表达,探讨细胞凋亡调控基因在大鼠胸腺细胞凋亡时的作用。方法采用原位标记(TUNEL)法检测DNA单链或双链的裂解;应用免疫组织化学染色法,观察不同剂量糖皮质激素诱导的大鼠胸腺细胞凋亡时FAS和FASL基因的表达。结果镜观察地塞米松组TUNEL阳性细胞较多并且分散在皮质各处。免疫组织化学结果表明,正常对照组胸腺内FAS呈低表达,随着地塞米松剂量的增加FAS的表达成递增趋势,地塞米松各组与对照组比较差异有统计学意义(P<0.05);正常对照组胸腺内FASL呈高表达,随着地塞米松剂量的增加FASL的表达成递减趋势,地塞米松各组与对照组比较差异有统计学意义(P<0.05)。结论促凋亡蛋白FAS和抗凋亡蛋白FASL在糖皮质激素诱导引起的胸腺细胞凋亡调控中起重要作用。

Objective To detect the expression of FAS and FASL gene in rats thymocyte apoptosis, and to investigate the effect of apoptosis regulated gene in the rats thymocyte apoptosis. Methods Terminal deoxynucleotidyl transferase （TdT）- mediated dUTP-biotin nick end-labeling （TUNEL） method was used to detect the DNA fragmentation or double strand breaks. The expression of FAS and FASLgene in rats thymocyte apoptosis were induced by various dose of glucocorticoids, and the gene expression were determined by immunohistochemical staining. Results The TUNEL positive thymocytes were scattered throughout the cortex of GC-treated thymus.Immunohistochemical staining showed thatFAS expression decreased as the dose increased in the DEX-groups whereas the expression of FAS in the controls was increase. Significant differences were found between the DEX-groups and the controls （P〈0.05）. The FASL expression increased as the dose increased in DEX-groups whereas in the controls FASL were overexpression. Significant differences were found between the DEX-groups and the controls （P〈O.05）. Conclusion FAS and FASL played an important role in the glucocorticoids-induced thymocyte apoptosis.