微波对神经元Tfam表达的影响及与能量代谢障碍的关系

Effects of microwave exposure on Tfam expression in neurons and the relationship with energy metabolism disturbance

为了探讨微波辐照对神经元线粒体转录因子A(Mitochondrial transcription factor A,Tfam)表达的影响以及与能量代谢障碍的关系,本实验以体外培养的大脑皮层神经元为研究对象,将其暴露于微波中辐照15min,在辐照后即刻、6h、12h、24h、48h等5个时相点,分别采用高效液相色谱(High performance liquid chro- matography,HPLC)检测神经元三磷酸腺苷(Adenosine triphosphate,ATP)、二磷酸腺苷(Adenosine diphosphate,ADP)和一磷酸腺苷(Adenosine monophosphate,AMP)的含量,用实时定量聚合酶联式反应(Real-time polymerase chain reaction,Real-time PCR)和荧光蛋白质印迹(Western-blot)检测Tfam信使核糖核酸(messenger ribonucleic acid,mRNA)和蛋白的表达情况。研究发现,辐照后ATP含量呈进行性下降,Tfam mRNA和蛋白表达均增加。说明微波辐照能明显引起神经元能量代谢障碍,而新增的Tfam并未改善微波对能量代谢的影响。提示微波可能是通过抑制Tfam从胞浆向线粒体内的转运,从而损伤Tfam调节能量代谢的生物学功能。

In order to study the effects of microwave （MW） exposure on the mitochondrial transcription factor A（Tfam） expression in neurons and explore the relationship between Tfam and the energy metabolism disturbance the experiment model with exposing primary cultured cortical neurons to the microwave for 15rain has been established in our group. The concentration of adenosine triphosphate （ATP）, adenosine diphosphate （ADP） and adenosine monophosphate （AMP） at Oh, 6h, 12h, 24h and 48h after exposure has been measured by high performance liquid chromatography （HPLC）. And the real-time polymerase chain reaction （PCR） and fluorescence western-blot has been applied to detect the changes of the Tfam messenger ribonucleic acid （mRNA） and protein levels respectively. The results show that the concentration of ATP decreases in a time-dependent manner after exposure and both of the mRNA and protein expression of Tfam are up-regulated. It demonstrates that microwave exposure dramatically disturbs energy metabolism of neurons. However, newly-increased Tfam can＇t up-regulate the ATP concentration as expected. It suggests microwave may have an adverse effect on the biological activity of Tfam in regulating the energy metabolism through inhibiting the import of Tfam from cytoplasm into mitochondfia.