Neuroprotective effects of 4-aminopyridine-targeted TMEM175 and modulating autophagy in Parkinson disease mice

Wang Zihao; Xia Huan; Gao Meirong; Deng Anxia; Wang Xiaobei; Du Xinyu; Yang Xinling

doi:10.3969/j.issn.1009-6574.2025.05.003

Abstract：Objective To explore the neuroprotective effects and autophagy regulation of 4-aminopyridine(4-AP)as a transmembrane protein 175(TMEM175)inhibitor in Parkinson disease(PD)mice.Methods A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mouse model was used,involving 60 C57BL/6 mice,which were randomly divided into four groups,including control group,MPTP group,4-AP group and 4-AP+MPTP group,with 15 mice in each group.The effects of 4-AP on dopamine neurons,TMEM175 expression and autophagy levels were assessed by behavioral testing,molecular docking,immunohistochemistry,Western blot,RT-qPCR and ELISA.Results Behavioral analysis showed that the speed of mice in MPTP group was(5.4±1.1)cm/s,which was lower than that of(6.8±0.6)cm/s in control group and(6.4±0.9)cm/s in 4-AP+MPTP group,and the difference was statistically significant(all P＜0.05).The free movement time and forelimb grip strength of mice in MPTP group were(155.1±9.0)s and(173.8±13.5)g,respectively,which were lower than those of 4-AP+MPTP group(164.2±9.2)s and(191.3±16.1)g,respectively,and the differences were statistically significant(all P＜0.05).Compared with MPTP group,the expression of TMEM175 protein(P＜0.001)and mRNA(P＜0.01)was decreased,and the levels of TH protein(P＜0.05)and mRNA(P＜0.01)were elevated in 4-AP+MPTP group of mice,and the differences were statistically significant.The levels of autophagy markers LC3A(P＜0.01)and Beclin-1(P＜0.001)were increased in MPTP group,whereas the expression was reduced in 4-AP+MPTP group(P＜0.05),and the differences were statistically significant.Conclusions 4-AP improves motor function and reduces dopamine neuron loss in PD mice by targeting TMEM175 channels and regulating autophagy-related protein levels.