Dynamic Detection Of Pathology During The Establishment Of Etiological Monkey Models Of Parkinson’s Disease

Parkinson’s disease(PD)is the second major neurodegenerative disease characterized by Lewy body(LBs).The main pathogenic protein of PD isα-synuclein(α-syn),so it is called synucleinopathy.Its pathogenic mechanism is still unclear,which is the reason for the challenges of preclinical and drug development research of PD.And disease research relies on disease models;therefore,it is necessary to establish a PD model similar to the pathological process and behavioral symptoms of PD patients.In the study,a-synuclein prefabricated fibers(PFF)and adeno-associated virus(AAV2/9)mediating a-syn overexpression combined with PAR were injected into the striatum and substantia nigra(SN),respectively,to establish an non-human primates PD model(NHP-PD)using deep-brain stereotaxic techniques;the pathological changes and the levels of neurotransmitters and metabolites in cerebrospinal fluid(CSF)were detected by pathology and high performance liquid chromatography-tandem mass spectrometry(HPLC-MSIMS),respectively;and the PD-kurlun score was used to evaluate the behavior of monkeys.The pathological results showed that,compared with control,the dopaminergic(DAergic)neurons in SN decreased by 27.1%in the monkey injected with PFF at 1-month.The neurons were damaged and the DAergic neurons in the damaged side(ipsilateral)and the healthy side(contralateral)of the AAV-monkey’s SN were significantly lost,decreased by 70.25%and 57.02%at 4-month,81.5%and73.1%at 18-month;the loss of DAergic neurons in ipsilateral was particularly pronounced.Phosphorylatedα-syn(P-α-syn)was observed in DAergic neurons of SN,and the presence of insolubleα-syn,showing an LBs-like structure with proteinase-K resistance and thioflavin-T positive characteristics.Meanwhile,there were observed LBs-like structure in the striatum,hippocampus,and cortex of the ipsilateral.A large number of activated astrocytes and microglia were observed in the ipsilateral;remarkably,we observed that the integrity of mitochondrial membranes in neurons of SN was damaged;and these pathological changes were more obvious at 18-month than at 4-month.Compared with the monkey models of MPP~+and 6-OHDA,these pathological changes are consistent with this unilateral PD model monkeys.And,the motor symptoms of the experimental monkeys reached the evaluation standard of semi-Parkinsonian syndrome by behavioral analysis,mainly reflected in abnormal posture and lack of facial expressions.In addition,the metabolomics results showed that,compared with those before modeling,there were differences in the levels of nine neurotransmitters and metabolites in CSF,as following acetylcholine,5-oxindoleacetic acid,tryptophan,homovanillic acid,pantothenic acid,hypoxanthine,N,O-dimethylvenlafaxine,glutamine and heptadecanoic acid.In conclusion,NHP-PD models with PD-like pathological characteristics and behavioral symptoms were induced with PFF and overexpression of a-syn,based upon the interaction of the PAR,and multiple differential metabolites in CSF were detected.