The Pyrethroids Metabolite 3-Phenoxybenzoic Acid Induces Dopaminergic Degeneration

Objective A variety of pyrethroids can cause PD-like pathological changes in cells and/or mice,and 3-phenoxybenzoic acid(3-PBA)is a common metabolite of many pyrethroids.In order to clarify 3-PBA Whether it is the key substance of pyrethroid-induced PD,the toxic effects of 3-PBA on the dopaminergic nervous system were studied in vivo and in vitro,and the key mechanism of action was found.Methods 1.Liquid chromatography tandem mass spectrometry(LC-MS/MS)was used to detect the drug concentrations of FEN,3-phenoxybenzoic acid(3-PBA)and cypermethic acid(TMCA)in mouse tissue samples.The content of CEs in various tissues of mice was detected by carboxylesterase(CEs)kit.2.The expression changes of PD-related proteins in SH-SY5 Y cells and mice by FEN and 3-PBA were detected by Western blot(WB),immunofluorescence(IF)and immunohistochemistry(IHC),respectively.3.By dopamine transporter-positron emission tomography(PET-DAT),the mice were subjected to autologous control experiments to detect the effects of different concentrations of 3-PBA on DAT in the mouse brain.4.The expression changes of α-synuclein-related proteins induced by AEP cleavage in SH-SY5 Y cells and mice by 3-PBA were detected by WB,IF and IHC,respectively.Results 1.LC-MS/MS detection showed that FEN was metabolized into 3-PBA and TMCA after entering the body.No matter in brain tissue or blood,3-PBA showed obvious bioaccumulation;CEs in liver tissue The concentration was much higher than that in brain tissue and blank control group;there was no statistical difference between CEs content in brain tissue and blank control group.2.WB,IF and IHC showed that both FEN and 3-PBA could increase the expression of total α-synuclein,α-synuclein monomer,α-synuclein oligomer and phosphorylated α-synuclein in vivo or in vitro,and The pathological changes caused by 3-PBA were more significant.3.PET-DAT and WB detection showed that lowdose 3-PBA can cause the increase of DAT in the mouse brain,and the middle dose of 3-PBA can cause the decrease of DAT in the mouse brain.DAT in the rat brain had little effect.4.WB,IF and IHC assays showed that 3-PBA could induce an increase in activated AEP and sheared N103 fragments in vivo or in vitro,total α-synuclein,α-synuclein monomer,α-synuclein oligomer and increased expression of phosphorylated α-synuclein.Conclusion 1.LC-MS/MS detection showed that FEN was metabolized into 3-PBA and TMCA after entering the body.No matter in brain tissue or blood,3-PBA showed obvious bioaccumulation;CEs in liver tissue The concentration was much higher than that in brain tissue and blank control group;there was no statistical difference between CEs content in brain tissue and blank control group.2.WB,IF and IHC showed that both FEN and 3-PBA could increase the expression of total α-synuclein,α-synuclein monomer,α-synuclein oligomer and phosphorylated α-synuclein in vivo or in vitro,and The pathological changes caused by 3-PBA were more significant.3.PET-DAT and WB detection showed that lowdose 3-PBA can cause the increase of DAT in the mouse brain,and the middle dose of 3-PBA can cause the decrease of DAT in the mouse brain.DAT in the rat brain had little effect.4.WB,IF and IHC assays showed that 3-PBA could induce an increase in activated AEP and sheared N103 fragments in vivo or in vitro,total α-synuclein,α-synuclein monomer,α-synuclein oligomer and increased expression of phosphorylated α-synuclein.Conclusion 1.3-PBA is prone to bioaccumulation in brain tissue;2.Both FEN and 3-PBA can cause PD-like pathological changes in vivo or in vitro,and the pathological changes caused by 3-PBA are more significant;3.Different doses of 3-PBA caused different changes in DAT expression.4.3-PBA cleaves α-synuclein to form N103 fragments by activating AEP,thereby promoting the formation of α-synuclein oligomers.