The Molecular Mechanism Of PTX3 Secreted By Human Cell Adipose Derived Stem Cells Promotes The Repairation Of Dopaminergic Neurons In Parkinson’s Disease Via Inhibiting Apoptosis

Background:Parkinson’s disease(PD)is a progressive neurodegenerative disease.Its main pathology are related to the degeneration and loss of dopaminergic neurons in the substantia nigra(SN)striatum(Striatum,STR)pathway of the midbrain.At present,the treatment of PD is mainly based on levodopa replacement therapy.Although it could improve the patient’s behavioral symptoms,it couldn’t prevent the progression of the disease,and long-term medication would cause greater side effects.Adipose-derived mesenchymal stem cells(hADSCs)had become the focus of attention of the majority of scientific researchers due to their abundant sources,convenient materials,low immunogenicity,and no ethical controversy.Pentraxin-3(PTX3),also known as tumor necrosis factor(TNF)inducible gene 14 protein(TSG-14),belongs to the acute phase protein superfamily,which could promote tissue repair and promote brain function recovery and neuron regeneration after stroke Function.Therefore,PTX3 had received more and more attention in central nervous system diseases.This study mainly explored whether PTX3 secreted by hADSCs inhibitted the apoptosis of 6-OHDA-injured dopaminergic neurons.Method:One-sided injection of 6-OHDA into the substantia nigra to construct a PD mouse model,stereotactic injection of hADSCs in the striatum,to evaluate its therapeutic effect in the 6-OHDA-induced mouse model.In addition,tissue organ type brain slices were used as an in vitro model of PD,and the treatment effect was evaluated by hADSCs co-culturing with 6-OHDA-induced brain slices.Through RNA-seq,human protein cytokine array and label-free quantitative proteomics(label-free)analysis of cytokines secreted by hADSCs,the key cytokine PTX3 secreted by hADSCs was identified.QRT-PCR,western blot,Fluoro-Jade C,Tunel experiment and immunofluorescence analysis were used to evaluate the effect of PTX3 secreted by hADSCs on DA neuron apoptosis and analyze its specific molecular mechanism.Result:In this study,we found that hADSCs had a protective effect on dopaminergic(DA)neurons in in vivo and in vitro models.And confirmed that Pentraxin3(PTX3)is a key cytokine in the protection of DA neurons in hADSCs.In addition the application of stereotactic injection of recombinant human Pentraxin3(rhPTX3)improved the behavioral symptoms of PD mice and played a neuroprotective effect on DA neurons.In vitro models had also confirmed that rhPTX3 also protects DA neurons.And the results of siPTX3 treatment of PD models in vivo and in vitro showed that the therapeutic effect of hADSCs is significantly better than that of siPTX3.The results of tunel and Fluoro-Jade C show that both hADSCs and rhPTX3 can reduce DA neuron apoptosis,but siPTX3 is not as effective as hADSCs in inhibiting apoptosis.Further,the results of q-PCR and western blot found that after treatment with hADSCs or rhPTX3,the expression of caspase3,caspase8,TRADD,and FADD in DA neurons was significantly reduced.ConclusionThis study revealed that the secretion of PTX3 by hADSCs inhibited DA neuronal cell apoptosis and degeneration and improved the behavioral symptoms of PD mice,thereby exerting neuroprotective effects.It also provides a theoretical basis for the development of drugs based on PTX3 to treat PD,and has potential clinical translational value.