Increases And Redistribution Of Nicotinamide Nucleotide Transhydrogenase And Thioredoxin Closely Are Associated With Death Of Neural Cells In Tg(SOD1*G93A)IGur Mice

Introduction: Current studies suggest that NNT and TRX are involved in mitochondrial energy metabolism,prevent overproduction of ROS,and reduce the toxicity of oxidative stress on nerve cells.Our preliminary proteomic analysis found the up-regulation of nicotinamide nucleotide transhydrogenase(NNT)and thioredoxin(TRX)in the spinal cord of Tg(SOD1*G93A)1Gur(TG)mice.To the end,we further studied the association between NNT,TRX and neural cell death in ALS to search the potential pathogenesis of ALS.Methods: Purchase G93A-SOD1 C57BL/6J transgenic mouse animal model,feeding,breeding,progeny mice using PCR technology to detect the animal model which carried the SOD1*G93A mutation transgenic mice,formalin fixed mice,complete removal of mice The brain and spinal cord.The SOD1 G93 A transgenic animals fixed with formalin,then took out the mouse spinal cord and brain compeletly.Then it was fixed with formaldehyde again,dehydrated with a gradient of sucrose with different solubility,embedded in OTC gel,and stored in a-80°C refrigerator to make a tissue section.Use the dual fluorescence immunofluorescence staining to label the NNT,TRX,neurons,astrocytes,oligodendrocytes and cell nuclei were observed and photographed under the same field of view and the same magnification of the fluorescence microscope.The photographed images were processed with image processing software such as NIS-Element F and IPP.We observed and analyzed the characteristics of NNT and TRX positive cells in different disease stages(60-70 days in non-infected group,90-100 days in diseased group,120-130 days in advanced group)and in different anatomical regions(cervical,thoracic,lumbar spinal cord).The relationship between neuronal cells,astrocytes and oligodendrocytes,and the relationship between NNT and TRX-positive cell numbers and neuronal cell death.Results:1.In SOD1 WT mice,NNT positive cells(NNTPCs)are distributed throughout the spinal cord anatomy,and there is no significant difference between the cervical,thoracic,and lumbar spinal cords.2.In SOD1 WT mice,NNT were mainly distributed in the nuclear and cytoplasm of oligodendrocyte and neurons in spinal cord,and gradually increased following aging.3.In TG mice,NNTPCs increased significantly with progression of the disease,there was no significant difference between the cervical,thoracic and lumbar spinal cords,indicating that NNT did not migrate between spinal segments;However,it can be seen that the transition from GM to WG,from the gray matter surrounding the central canal(GCC),posterior funiculus(PH)to AH,and from AF and PF to LF.NNT is mainly distributed in oligodendrocytes and neurons.In TG mice,not only does NNT increase expression,but also migration from the nucleus into the cytoplasm can be observed..4.TRX is distributed in the same nerve cell of NNT,TRXPCs are also gradually increased with disease progression,and it is seen in TG mice that they migrate from the cytoplasm to the nucleus with a decrease in expression.Conclusion: Our study suggested that NNT participated in the pathogenesis of ALS through the TRX pathway,The main mechanism of action may be mitochondrial energy metabolism,prevent overproduction of ROS,reduce the toxicity of oxidative stress on nerve cells,and thus play a protective role in ALS.