Fig. 4

MPTP-induced immune responses in mouse brain can be attenuated to a certain degree one month after intraperitoneal injections of low-dose(s) of LPS. A The experimental schedule diagram illustrating the establishment of MPTP-induced mouse model of Parkinson’s disease following the induction of IIM. B The changes in body weight during and after MPTP injections. n = 6–7 /group. Differences were analyzed by two-way ANOVA followed by LSD multiple comparison tests. **p < 0.01, ***p < 0.001. C The summary heatmap of protein levels based on Luminex assay of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ), anti-inflammatory cytokines (IL-4 and IL-10) and chemokine (MCP-1) in the striatum of mice at 3 days post-saline or MPTP treatment. n = 4/group. D, E Assessments of microglial activation in the nigrostriatal pathway. Immunofluorescence staining of IBA1 (red) in the striatum (D) and immunofluorescence double staining of TH (green) and IBA1 (green) in the substantia nigra (E) at 7 days post-saline or MPTP administration. Scale bar, 100 μm. Quantification of IBA1⁺ cells in the dorsal striatum and the SNpc is shown in the bottom panel. n = 4/group. Differences were analyzed by two-way ANOVA followed by LSD multiple comparison tests. **p < 0.01, ***p < 0.001