DEAD-box RNA解旋酶5和转录因子12与肌萎缩侧索硬化症的关系

Relationship between DEAD-box helicase 5,transcription factor 12 and amyotrophic lateral sclerosis

目的通过检测DEAD-box RNA解旋酶5(DDX5)和转录因子12(TCF12)在SOD1-G93A突变型肌萎缩侧索硬化症(ALS)转基因小鼠海马中表达情况及其相互作用关系,揭示DDX5和TCF12表达改变与ALS海马病变的关系。方法将42对SOD1-G93A突变型ALS转基因小鼠和野生型小鼠,按照95 d龄(发病早期)、108 d龄(发病中期)和122 d龄(发病晚期)分为3组,通过RT-PCR、Western blotting和免疫荧光双标记技术,检测DDX5和TCF12在海马中的表达情况,通过免疫共沉淀技术检测DDX5和TCF12蛋白之间是否具有相互作用。结果与同龄野生型小鼠相比,在SOD1-G93A突变型ALS转基因小鼠海马中DDX5和TCF12 m RNA无明显变化,而蛋白在95 d、108 d和122 d表达均上调,差异均有统计学意义。海马齿状回和海马本部均可见DDX5和TCF12阳性细胞,且DDX5和TCF12在海马神经元中表达。SOD1-G93A突变型ALS转基因小鼠海马中DDX5和TCF12免疫阳性反应均较同龄野生型小鼠增强。免疫共沉淀实验检测发现,DDX5和TCF12蛋白质之间存在相互作用。结论DDX5和TCF12蛋白在SOD1-G93A突变型ALS转基因小鼠海马组织中表达上调,DDX5和TCF12表达异常与ALS海马组织病变有关。

Objective To explore the relationship between the expression of DEAO-box helicase 5(DDX5)and transcription factor 12(TCF12)with amyotrophic lateral sclerosis(ALS)hippocampal lesions by detecting the expressions and the interaction of DDX5 and TCF12 in the hippocampus of SOD1-G93 A mutant ALS transgenic mice.Methods Fortytwo pairs of SOD1-G93 A mutant ALS transgenic mice and wild-type mice were divided into three groups at the age of 95 days(early onset stage),108 days(middle onset stage)and 122 days(late onset stage).RT-PCR,Western blotting and double immunofluorescence labeled technique were used to detect the expressions of DDX5 and TCF12 in the hippocampus.Co-immunoprecipitation assasy was used to detect the interaction between DDX5 and TCF12.Results Compared with the wild-type mice of the same age,DDX5 and TCF12 mRNA in the hippocampus of SOD1-G93 A mutant ALS transgenic mice were unchanged,but DDX5 and TCF12 protein were up-regulated significantly at day 95,108 and 122.DDX5 and TCF12 positive cells were found in both DG area and hippocampus proper,and DDX5 and TCF12 were co-localized with neurons.The immunoreactivities of DDX5 and TCF12 in the hippocampus of SOD1-G93 A mutant transgenic mice were elevated compared with wild-type mice at the same time point.Co-immunoprecipitation assasys confirmed that there existed interactions between DDX5 and TCF12 protein.Conclusion DDX5 and TCF12 protein are up-regulated in the hippocampal tissues of SOD1-G93 A mutant ALS transgenic mice.The abnormal expressions of DDX5 and TCF12 are involved in the hippocampal lesions of ALS.