衰老小鼠脾脏T淋巴细胞凋亡特征的变化  

Changes of apoptotic features of splenic T lymphocytes in senescent mice

作　　者：王真[1] 邓洪斌[1] 李电东[1] 

机构地区：[1]中国医学科学院中国协和医科大学医药生物技术研究所,北京市100050

出　　处：《中华老年医学杂志》2003年第11期669-672,共4页Chinese Journal of Geriatrics

基　　金：国家重点基础研究发展规划基金 (G2 0 0 0 0 5 70 10 );国家自然科学基金 (NO 3 0 0 70 82 7)

摘　　要：目的　研究不同诱导方式下小鼠T淋巴细胞凋亡率随增龄的变化状况。　方法　通过白细胞介素 2 (IL 2 )与伴刀豆球蛋白A(ConA)刺激和星形孢菌素两种方式诱导凋亡 ;流式细胞术检测凋亡率 ;琼脂糖凝胶电泳观察DNA梯带 ;Fluo 3钙荧光探针检测细胞内游离钙水平 ;蛋白质免疫印迹检测bcl 2蛋白。　结果　IL 2与ConA联合刺激 18h后 ,老年小鼠T细胞平均凋亡率 (38 3±10 3) %明显低于青年小鼠T细胞〔(5 8 6± 4 0 ) % ,P <0 0 5〕。老年小鼠T细胞DNA梯带的比例、游离钙基准水平和刺激 18h后的钙水平都明显低于青年小鼠T细胞 ;星形孢菌素处理 4h和 8h后 ,结果与IL 2与ConA联合刺激类似。老年小鼠T细胞抗凋亡蛋白bcl 2表达水平明显升高。　结论　老年小鼠周围T淋巴细胞在活化刺激或加入凋亡诱导剂后凋亡率显著低于青年小鼠。Objective Increased morbidity of auto-immune disease in senescent individual might be related with the defects of apoptosis after stimulation or induction. Changes of apoptotic features in splenic T lymphocytes were studied in senescent mice. Methods Flow cytometry was used to study the rates of apoptosis by analysing sub-G 1 peak. DNA ladder was observed by agarose gel electrophoresis. Free calcium levels in both cells were detected by Fluo-3 loading. Bcl-2 protein levels were detected by Western blot. Results After co-stimulation with IL-2/ConA, flow cytometry showed that average apoptotic percentage of old T cells was 38.3% ±10.3%,significantly lower than that of young ones (58.6% ± 4.0%, P < 0.05). DNA ladder electrophoresis showed similar results between both T cells. Both baseline and stimulated calcium levels were shown lower in senescent T cells than in young ones. Also after being induced with staurosporine for 4 and 8 h, average apoptotic percentages were 28.1%±2.2% and 52.6%±9.6% respectively in young cells, and 17.1%±6.7% and 36.3%±7.7% respectively in old ones. And relative calcium levels before and after induction were also lower in old T cells when compared with young ones. Western blot indicated that increased expression of anti-apoptotic protein bcl-2 perhaps explained the decreased apoptotic ability in senescent splenic T lymphocytes. Conclusions Age-related defects in apoptosis may contribute to the disturbed immune system function and increased auto-immunity often occurred in old individuals.

关 键 词：衰老 脾脏 T淋巴细胞 细胞凋亡 

分 类 号：R339.38[医药卫生—人体生理学] R392.12[医药卫生—基础医学]