小鼠大脑皮层端粒重复序列结合因子2的表达及神经元保护作用

Expression changes of telomeric repeat-binding factor 2 in mouse cortical neurons during aging

目的 观察小鼠大脑皮层端粒重复序列结合因子2（telomeric repeat binding factor 2,TRF2）表达的增龄性改变,探讨TRF2基因转染对体外培养皮层神经元的保护作用及TRF2在神经元衰老中的作用. 方法 将C57BL/6J小鼠分为青年组（2月龄）和老年组（20月龄）,分别采用蛋白质免疫印迹法（Western blot）和实时定量聚合酶链反应（Real-time PCR）检测小鼠大脑皮层TRF2表达;pcDNA-TRF2质粒转染孕18 d胎鼠皮层神经元细胞,喜树碱作用16h,四甲基偶氮唑蓝（MTT）比色法检测神经元细胞存活率. 结果 与2个月龄组小鼠比较,20个月龄组小鼠大脑皮层TRF2表达明显降低;喜树碱作用16h后,转染pcDNA-TRF2的神经元存活率为（75.4±2.6）％,明显高于与转染空载体质粒组（32.6±9.3）％（t=22.85,P＜0.05）. 结论 TFR2表达降低参与神经元衰老,TRF2过表达可能是治疗神经退行性变的新靶点.

Objective To observe expression changes of the telomeric repeat binding factor 2 （TRF2） in mouse cortical neurons during aging and its biological significance.Methods TRF2 expression in cortical neurons of young （2 months） and old （20 months） C57BL/6J mice were tested by Western blot and real time PCR.pcDNA-TRF2 was transfected in embryonal cortical neurons.Neurons viability was determined by MTT after exposure to camptothecin for 16 h.Results TRF2 expression decreased significantly in cortical neurons in old mice than that in young mice.After exposure to camptothecin for 16 h,（75.4±2.6） ％ of pcDNA TRF2 transfected neurons were viable and the transfection rate was higher in pcDNA-TRF2 transfected neurons than in control transfected neurons [（32.6 ± 9.3） ％] （t =22.85,P ＜ 0.05）.Conclusions TRF2 expression decreases significantly in aging mouse,downregulation of TRF2 may participate in neurons aging,and TRF2 overexpression may be a potential therapeutic target against neurodegeneration.