Fig 2: Pg infection enhances microglial elimination of synapses in App KI mice. (A) Representative high magnification Z-stack images showing SNAP 25 (presynaptic marker, red) and PSD95 (postsynaptic marker, green) synaptic terminals in the cortex and hippocampus from non-infected and Pg-infected App KI mice at 10 months of age. (B–D) Quantification of PSD95 puncta (B), SNAP25 puncta (C), and the co-localized PSD95 and SNAP25 puncta (D) in the cortex and hippocampus CA1 regions from non-infected and Pg-infected App KI mice at 6 and 10 months of age. Scale bar: 2 µm. (E) Representative high magnification Z-stack images of C1qa (green) and PSD95 (red) co-stained puncta in the cortex and hippocampus of the brains from non-infected and Pg-infected App KI mice at 10 months of age. Circles show examples of C1qa puncta co-localized with PSD95 puncta. Scale bar: 4 µm. (F) Quantification of co-stained C1qa and PSD95 in the cortex and hippocampus CA1 regions from non-infected and Pg-infected App KI mice at 6 and 10 months of age. (G) Representative high magnification Z-stack images of subicular microglia (IBA1+, red) co-stained with PSD95 (green) from non-infected and Pg-infected App KI mice at the 10 months of age, displaying elimination of synapses by microglia. Scale bar, 5 µm. (H) Quantification of engulfed PSD95 puncta density in microglia in the cortex and hippocampus CA1 regions of the brains from non-infected and Pg-infected App KI mice at 6 and 10 months of age. Data are expressed as mean ± SEM (n=4-7 mice/group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 by two-way ANOVA followed with Tukey correction.

Fig 3: TLB alleviated synaptic degeneration in AD model mice. (a) Representative images of spine morphology in each group. (b, c) Quantitative analysis of total spine density and mushroom-type spine density. (d) The representative blots of PSD95, SNAP25, Syn1, SYP, and VAMP1 in each group. (e–i) Quantitative analysis of PSD95, SNAP25, Syn1, SYP, and VAMP1 protein levels. n = 6 per group. *p < 0.05; **p < 0.01; ***p < 0.001.

Fig 4: GSDMD-KO mitigated neuropathological alterations in the peri-injury cortex at 3 days after TBI. (A) Representative images of immunoblots for synaptic proteins (PSD95, SYN1, SNAP25, and VAMP1) and total protein. (B–E) Quantitative analysis of synaptic proteins (n = 6). (F) Representative immunofluorescence images of CD68, GFAP, MAP2, and NeuN in the peri-injury cortex after TBI or in the paired sham cortex. Scale bar = 50 µm. (G–J) Quantitative analysis of integrated intensity of CD68+, GFAP+, and MAP2 + cells and NeuN+ cell number/mm2 in the cortex (three slices from each brain and three brains were used for calculation). All data are presented as the mean ± SEM and were analyzed using one-way ANOVA followed by Tukey’s multiple comparisons test for significance. ns p > 0.05, *p < 0.05, **p < 0.01, and ***p < 0.001.

Fig 5: Effect of low dose and high dose methamphetamine (METH) on synaptic protein levels. (A) Representative IHC images of synaptic proteins SNAP25, PSD95 and Synaptophysin. (B) Relative intensity of SNAP25 level in Con, METHL and METHH mice cortex. One-way ANOVA, F (2, 26) = 40.098, p < 0.001. (C) Relative intensity of SNAP25 level in Con, METHL and METHH mice hippocampus. One-way ANOVA, F (2, 26) = 24.861, p < 0.001. (D) Relative intensity of PSD95 level in Con, METHL and METHH mice cortex. One-way ANOVA, F (2, 26) = 43.68, p < 0.001. (E) Relative intensity of PSD95 level in Con, METHL and METHH mice hippocampus. One-way ANOVA, F (2, 26) = 48.631, p < 0.001. (F) Relative intensity of Synaptophsyin level in Con, METHL and METHH mice cortex. One-way ANOVA, F (2, 26) = 42.155, p < 0.001. (G) Relative intensity of Synaptophsyin level in Con, METHL and METHH mice hippocampus. One-way ANOVA, F (2, 26) = 88.27, p < 0.001. n = 9 sections, 3 sections per mouse. *p < 0.05, **p < 0.01, ***p < 0.001 by one-way ANOVA and Bonferroni’s post hoc analysis.