Fig 2: Decreased MFN2 in 7-m APPKI mice brain. (A) Representative blots of hippocampal homogenates from 7-m APPKI mice. (B) Densitometry analysis of MFN2 expression. Tom 20 was used as a loading control for all the mitochondrial dynamic proteins. (C,D) Densitometry analysis of Tom 20, VDAC1, and mitochondrial complex I–V expression. GAPDH was used as a loading control for (C,D). Data are presented as mean ± SEM; n = 7–8 mice per group. Data were analyzed using Student's t-test, and significance was assumed when p < 0.05. *p < 0.05.

Fig 3: Inhibition of ERK downregulates autophagy through increasing Mfn2 in OGD/R-treated SH-SY5Y cells. A Representative immunoblot bands of LC3B, Beclin1 and p62. B-D, Quantitative analysis of expression of LC3B, Beclin1 and p62. All data in this figure are representative of three independent repeats and are shown as mean ±SEM. E The transmission electron microscopy images of autophagosomes/autolysosomes (red arrows). Scare bar: 1 μm. si-Mfn2(C): Mfn2 si-RNA without OGD/R group; PD: PD98059 group; Mfn2: Mfn2 si-RNA group. *P < 0.05 vs. Control, #P < 0.05 vs. Model, &P < 0.05 vs. PD

Fig 4: Transfection efficiency of si-RNA and overexpression plasmid. A Representative immunoblot bands of p-Drp1 and Drp1; B, C, Quantitative analysis of p-Drp1 and Drp1; D, SH-SY5Y cells transfected with Drp1S616E-GFP-M90 plasmid after 24 h observed under fluorescence microscope; E, Quantitative analysis of fluorescence intensity; F, H, Representative immunoblot bands of Mfn2 after transfected with si-Mfn2 and Mfn2 pcDNA3.1; G, I, Quantitative analysis of Mfn2. All data in this figure are representative of three independent repeats and are shown as mean ±SEM. si-NC: Drp1 si-RNA negative control group; si-751/si-843/si1684: Drp1 si-RNA sequences; Drp1S616E: Drp1S616E-GFP-M90 plasmid; Vector: Drp1S616E negative control group; si-1/si-2/si-3: Mfn2 si-RNA sequences; OE-Mfn2: Mfn2 pcDNA3.1. *P < 0.05 vs. si-NC and Control; #P < 0.05 vs. Vector

Fig 5: Mdivi-1 reduced Drp1 translocation and Drp1 phosphorylation after the LPS treatment. Mdivi-1 (0, 10, and 20 μM) was administrated to activated CD4+ T cells 30 min prior to the LPS stimulation. (a) Western blot assay and quantitative analysis of mitochondrial MFN2, OPA1, and Drp1 expression and cytosolic MFN2, OPA1, and Drp1 expression. (b) Western blot assay and quantitative analysis of Drp1 phosphorylation. The results are shown as the mean ± SD; n = 5. ∗ P < 0.05 vs. the control group (∗∗ P < 0.01, ∗∗∗ P < 0.001, and ∗∗∗∗ P < 0.0001); & P < 0.05 vs. the LPS group (&& P < 0.01, &&& P < 0.001).