The Mechanism Of PARP1 Inhibitor Improves Symptoms Of Parkinson’s Disease By Autophagy

BackgroundParkinson’s disease(Parkinson’s disease,PD)is a common neurodegenerative disease characterized by motor dysfunction,but its clinical treatment is limited.The typical pathological features of Parkinson’s disease are the decrease of dopamine(DA)neurons in the substantia nigra pars compacta and the formation of Lewy bodies characterized by the accumulation of α-synuclein.α-synaptic nuclear protein(α-synuclein)is a kind of presynaptic protein,which is widely expressed in the brain in the form of soluble monomers under physiological conditions and is encoded by SNCA gene.It has been shown that aggregated α-synuclein may be involved in the pathogenesis of Parkinson’s disease in many ways.However,how to block the accumulation of pathological α-synuclein in Parkinson’s disease is still unclear.Autophagy is an important self-regulatory mechanism of cells,which can degrade misfolded proteins and maintain cell homeostasis.It has been found thatα-synuclein can be degraded through autophagy,but in patients with PD,autophagy is impaired,resulting in reduced degradation of α-synuclein,increased aggregation and damage to neurons.Therefore,in-depth exploration of the degradation pathway of α-synuclein is of great significance for finding new targets for the treatment of PD.Poly(ADP-ribose)polymerase 1(poly ADP-ribose polymerase,PARP1)is the main regulator of many biological processes,such as DNA damage repair,apoptosis and so on.It can be activated by aggregated α-synuclein,which in turn aggravates the toxicity of α-synuclein.The mutual regulation between them is closely related to the pathological features of Parkinson’s disease.It has been reported that PARP1 is involved in hunger-induced autophagy.Therefore,we hypothesized whether it can restore autophagy and promote the degradation of α-synuclein by inhibiting PARP1,and then improve the symptoms of PD?Therefore,from the point of view of the pathogenesis of α-synuclein,to explore the mutual regulation mechanism among PARP1,autophagy and α-synuclein is of practical significance to clarify the biological basis of the occurrence and development of Parkinson’s disease and related treatment strategies.Purpose1.To explore whether PARP1 can become a new target for the treatment of Parkinson’s disease;2.To determine whether inhibition of PARP1 activity can reduce the aggregation ofα-synuclein and slow down the progress of PD;3.To explore whether PARP1 is involved in the degradation of α-synuclein by autophagy and in what way;Method1.Western boltting2.Apoptosis assay3.The detection of NAD+\ATP\mitochondrial membrane potential4.Immunohistochemical staining(IHC)5.Reverse Transcription-Polymerase Chain Reaction(RT-PCR)6.Co-immunopreipitation(CO-IP)7.Immunofluorescence assay(IF)8.Animal behavioral testsResult:1.Abnormal aggregation of α-synuclein leads to PARP1 activation and PAR production,as well as abnormal autophagy;2.Veliaprib,an inhibitor of PARP1,enhances the activity of SIRT1,then inhibits m-TOR,promotes the entry of TFEB into the nucleus and activates autophagy;3.Veliparib inhibits the interaction of TFEB-CRM1 and then inhibits the export of TFEB and activates autophagy by reducing PARylation_TFEB;4.PARP1 inhibitor Veliparib treatment reduced the apoptosis of α-synuclein aggregation cells and enhanced cell activity;5.PARP1 inhibitor Veliparib treated α-synucleinA53T transgenic mice to restore their motor ability.Conclusion:1.In a-synucleinA53T mice and cell models,activated PARP1 participated in the process of impaired autophagy.2.PARP1 inhibits the entry of TFEB into the nucleus by inhibiting the activity of SIRT1,and PARP1 regulates the extranucleation process of TFEB by par TFEB.3.Inhibit the activity of PARP1,enhance the activity of α-synucleinA53T cells and improve the motor function of α-synucleinA53T mice.