A Preliminary Study Of Genes Related To Parkinson's Disease

Parkinson's disease is a common neurodegenerative disease.Its most prominent pathological changes are degeneration and death of dopamine neurons in the substantia nigra,significant decrease of DA content in striatum,and the appearence of eosinophilic inclusion bodies in the cytoplasm of the residual neurons in the substantia nigra,that is Lewy body.The clinical manifestations include static tremor,bradykinesia,muscle rigdity and postural gait disorder,while the patient may be accompanied by depression,astriction,dyssomnia and other non-motor symptoms.By bioinformatics analysis we found BRX.a PD related gene.Using Drosophila as a model organism and using UAS/GAL4 system to overexpression or RNAi BRX in Drosophila,we found that overexpression of BRX had no effect on the number of dopamine neurons in PD model through the Immunohistochemical study of dopamine neurons in the brain of Drosophila melanogaster.But after BRX RNAi,the number of neurons in PD model was restored.In order to further investigate the expression of BRX in PD pathological Drosophila,we used BRX::GFP,a fusion protein,to characterize the expression level of BRX endogenous protein.The results showed that the expression of BRX in PD model was higher than that in control group.It is speculated that the loss of dopamine neurons in PD may be related to the high expression of BRX.Gene coexpression analysis showed that BRX belongs to MAX signaling pathway,while AOX and PNX are downstream inhibitors and activators of MAX pathway.In order to study the relationship between BRX and MAX signaling pathway,we used PNX::GFP fusion protein to characterize the expression level of PNX endogenous protein.It was found that the expression of PNX was also increased in PD model,which suggested that the increased expression of PNX might be related to BRX.Then we overexpressed and RNAi BRX.The results showed that the expression of PNX increased after overexpression of BRX and decreased after RNAi with BRX.Therefore,we speculated that BRX promoted the expression of PNX.Then we used TAB and P90 to inhibit the MAX pathway in the pathophysiological fruit fly of PD.The results showed that the loss of neurons was alleviated and the number of neurons recovered.This may be due to the inhibition of the MAX pathway,which increases the expression of AOX,thus reducing the symptoms of neuronal loss.So we overexpressed and RNAi AOX.The results showed that the number of neurons in PD model was recovered after overexpression of AOX,but RNAi on AOX had no effect on the number of dopamine neurons in PD model.It was preliminarily assumed that the high expression of BRX in PD model inhibited the expression of AOX and resulted in the loss of dopamine neurons.However,increasing the expression of AOX alleviates the loss of dopamine neurons.As to how BRX inhibits the expression of AOX,we use CHIP to verify that.The results showed that BRX protein was indeed bound to the DNA sequence of AOX,so we speculated that BRX protein was bound to the key DNA sequence of transcription expression of AOX gene as an inhibitory factor,thus preventing the transcription expression of AOX.At the same time,We expressed AOX and PNX under the drive of TH-GAL4,ESG-GAL4,NP1-GAL4,and observed the lifespan of Drosophila melanogaster.The results showed that overexpression of PNX led to the reduction of lifespan in all three GAL4 drivers,and it was speculated that the increase of MAX pathway activity would lead to the shorter lifespan in Drosophila melanogaster.Through the preliminary study of PD-related genes,we found that the selected BRX gene was really related to the pathology of PD Drosophila,the decrease of BRX and down-regulation of MAX pathway may provide a new way for the treatment of Parkinson's disease.