Experimental Study On Expression And Distribution Of Nerve Growth Factor In Spinal Cord Of Amyotrophic Lateral Sclerosis SOD1*G93A Transgenic Mice

Background and Objective:Nerve growth factor(NGF)is a protective factor of neural cells,the relationship between NGF and the development of amyotrophic lateral sclerosis(ALS)hasn't been completely understood.In this study,we observed and analyzed the NGF expression and distribution,and the relationship between NGF expression and distribution and neural cell death in ALS applied fluorescence immunohistochemistry method in SOD1 wild-type(WT)and Tg(SOD1*G93A)1Gur(TG)mice.Methods:We constructed the animal model of SOD1-G93 A C57BL/6J transgenic mice,and screened the animal model of transgenic mice by PCR.SOD1-G93 A transgenic mice were divided into pre-pathogenic group(60-70 days),pathogenic group(90-100days)and progressive group(120-130 days).NPCs were labeled with neuron precursor cells(Nestin and Vimentin),neuron cells were labeled with NeuN,astrocytes were labeled with GFAP,oligodendrocytes were labeled with Olig,and NGF-expressing cells were labeled with NGF.Dual fluorescence immunohistochemical staining was performed at the same time in each anatomical area,and the positive cells were observed under a microscope.The positive cells with different staining were superposed by image processing technology.The distribution characteristics of positive cells were observed and analyzed,and the number of positive cells was calculated.The number of NPCs,neurons and glial cells,and the type and expression of NGF in the relevant anatomical areas were analyzed.To analyze the expression and distribution of NGF in the spinal cord-related anatomical regions of wild type and G93 A SOD1 transgenic mice.Results:1.NGF was mainly distributed in the anterior horn,lateral horn and around the central canal in the spinal cord of normal adult mice,but almost not in the whitematter.2.The expression and distribution of NGF around the anterior horn(AH),lateral horn(LH)and central canal(CC)increased significantly in the ultra-early(non-onset)and early(onset)stages of ALS.However,NGF expression and distribution around AH,LH and C C decreased significantly during the progression of the disease.3.NGF co-immunoreactivity with astrocytes,neurons,oligodendrocytes and neuronal precursor cells(NPCs)was observed in mouse poliomyelitis(anterior horn,lateral horn and pericentral canal area).These results suggest that astrocytes,neurons and oligodendrocytes can produce NGF,and NPC can also produce NGF.4.In the pathological state of ALS,with the decrease of NGF expression and distribution,the death of nerve cells increased gradually.Conclusions:NGF is a protective factor of nerve cells.In the super early and early stage of ALS,nerve cells around AH,LH and C C produce more NGF,and NPCs produce NGF.This suggests that NGF plays a protective role in nerve cells,prevents nerve cell death,and has the potential to cause self-repair in the development of ALS.