Fig. 3: STN-DBS contributed a neuroprotective effect in PD mice through mTOR-dependent mitophagy.

a The integrity of mitochondria (neuron) measured via TEM. Magnification: 60,000×. b Marked mitochondrial ultrastructural injury was observed in the PD and PD-sham-DBS groups. In contrast, mitochondria in the PD-DBS and PD+Rap groups showed less injury, which disappeared after treatment with 3BDO (n = 6 per group; F_(5,30) = 20.9, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). c Western blot analysis of p-mTOR, mTOR, LC3, and p62 in different groups (shared with the same mice in Fig. 2g). d, e The mTOR and p-mTOR expressions were suppressed by STN-DBS in the PD mouse model, and this phenomenon disappeared when intervened with 3BDO (n = 6 per group; mTOR: F_(5,30) = 14.1, P < 0.0001; p-mTOR: F_(5,30) = 10.3, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). f STN-DBS reversed the decrease in LC3 II, and a similar result was also obtained in PD mice treated with rapamycin (F_(5,30) = 22.3, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). g The increased p62 expression in PD models was reversed by STN stimulation, which was inhibited by 3BDO injection (n = 6 per group; F_(5,30) = 42.9, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). h Co-localization of TH and p-mTOR via IF staining. i The p-mTOR expression was elevated in the dopaminergic neurons of PD but was decreased by STN-DBS and rapamycin. With the injection of 3BDO, the p-mTOR expression in dopaminergic neurons was not further influenced by STN-DBS (n = 6 per group; F_(5,30) = 19.1, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). j Mitophagosomes (neuron) observed via TEM in different groups (shared with the same mice in Fig. 3a). Magnification: 20,000×. k Fewer mitophagosomes (white arrows) were observed in the PD mice compared with the control. However, STN-DBS and rapamycin induced a marked increase in the number of mitophagosomes in the SN of the PD model (n = 6 per group; F_(5,30) = 24.8, P < 0.0001; one-way ANOVA followed by a Tukey post-hoc correction). I: control group; II: PD group; III: PD-sham-DBS group; IV: PD-DBS group; V: PD+Rap group; VI: PD-DBS + 3BDO group. ^*P < 0.05; ^**P < 0.01; ^***P < 0.001; ^****P < 0.0001. Error bars: standard deviation of the mean. STN-DBS subthalamic nuclei deep brain stimulation, PD Parkinson’s disease, SN substantia nigra, IF immunofluorescence, DAPI 4′,6-diamidino-2-phenylindole, TH tyrosine hydroxylase, p-mTOR phospho-mTOR, TEM transmission electron microscopy, ns not significant.