Conditional Knockout Of PARP1 Inhibits Ferroptosis Of Nerve Cells And Alleviates Peripheral Neuropathic Pain

BackgroundNeuropathic pain(NP)is a series of diseases that cause sensory abnormalities and pain due to the damage of the somatosensory nervous system.When the damaged appeared on the peripheral nervous system is called peripheral neuropathic pain(PNP).In recent years,the incidence rate of PNP has become higher and higher due to various causes and various social and environmental factors.At present,the major treatment of PNP is in accordance with the symptoms,so the study of etiology and intervention of PNP will become the focus of pain treatment.PARP1 plays an important role in cell stress,and its over-expression will lead to cell damage.In some animal models of PNP,inhibiting the expression of PARP1 has a good effect on pain,while some recent studies have found Ferroptosis in PNP animal models.The chronic constriction injury model(CCI/Bennett model)is an internationally wide and mature animal model that simulates PNP symptoms and is applicable to the study of neuropathic pain caused by various factors.ObjectivesTo establish nervous system conditional knockout PARP1 gene micePARP1Nes/Nes mice,and detect the expression of PARP1 in related tissues.The CCI model of mice was established,and to compare the behavioral test results whether PARP1Nes/Nes mice in CCI model could alleviate the symptoms related to PNP caused by operation compared with ordinary PARP1 expression mice.To detect the expression of PARP1 and its products in the dorsal root ganglia(DRG)of CCI model and the detection of Ferroptosis related indicators.To prove whether the iron death level of relevant nerve tissue can be reduced by interfering with the expression of PARP1 in CCI model.MethodsThe nervous system specific PARP1 knockout mice-PARP1Nes/Nes were established through the Nestin-Cre/loxP system,and the flox mice are with normal PARP1 expression.The PARP1Nes/Nes mice with nervous system specific PARP1 knockout were screened and bred through gene identification results.Von-Frey filament and infrared heat source emission instrument were used to conduct behavioral tests on mice and mice in the shape group after CCI to record the paw with draw threshold(PWT)and paw with draw latency(PWL)of mice.Western Blot and immunofluorescence techniques were used to detect the expression of related proteins in mouse DRG tissue and the level of Ferroptosis.Result1.Hybridized the mice and predicted the genotype proportion of offspring through Mendel’s law detected the genotype of mice through gene identification.Our study has successfully established PARP1Nes/Nes mice,and had kept the reproduction stable and pure.2.WB detected the expression of PARP1 in the nervous system of PARP1Nes/Nes mice,the results showed PARP1 significantly reduced,and the expression of other tissues were the same as those of ordinary mice.3.Behavioral tests showed that the index of PWT and PWL after CCI surgery has been decreased,and the PWT and PWL of CCI model PARP1Nes/Nes mice decreased less than that of common CCI model mice.4.WB and immunofluorescence detection showed that the expression of PARP1 and its products in DRG tissue of mice in each group increased after CCI surgery,while PARP1Nes/Nes mice did not increase significantly;The level of Ferroptosis in DRG tissue increased after CCI surgery,and the level of Ferroptosis in DRG of CCI model PARP1Nes/Nes mice was less than common CCI model mice.Conclusion1.The conditional knockout of PARP1 gene in neurons in the nervous system of PARP1Nes/Nes mice resulted in a significant decrease in the expression of PARP1 in the nervous tissue,and did not affect the expression of PARPI in the other tissues.2.The inhibition of PARP1 expression in nerve tissue caused by the deletion of PARP1 gene in neurons of mice can alleviate the symptoms of type and thermal hyperalgesia after CCI.3.Overexpression of PARP1 and its products in DRG tissue can be discovered after CCI surgery,while PARPINes/Nes mice can effectively inhibit this phenomenon and reduce the death level of iron in DRG tissue after CCI surgery.4.By inhibiting the expression of PARP1,the level of Ferroptosis in DRG tissue of CCI mice can be reduced.5.Inhibiting the expression of PARP1 in nerve tissue can reduce the increased level of iron death in DRG tissue of CCI model mice,and improve postoperative hyperalgesia symptoms.