Fig. 5.

Autophagy contributes to metformin’s beneficial effects in senescence. A, Proteomics of aorta specimens from metformin-treated mice revealed 202 upregulated and 252 downregulated proteins, with statistical significance. B and C, GO and COG analyses showed metformin’s targets were markedly enriched in catalytic activity, posttranslational modification, protein turnover, and chaperones. D and E, The autophagosome levels in aorta specimens from the 4 groups were examined by TEM (one-way ANOVA, Tukey post hoc; n = 4). Scale bar = 1.0 µm (upper panel) or 500 nm (lower panel). F and G, LC3, and p62 levels in aorta samples were assessed by immunofluorescence; α-SMA was simultaneously stained to confirm the location of VSMCs. H, I, and J, Immunoblot assessment of LC3 and p62 in aorta specimens, with α-tubulin used for normalization (one-way ANOVA, Tukey post hoc; n = 5). Data are mean ± SD. *P < 0.05, ^**P < 0.01, and ^***P < 0.001 versus control group or for indicated comparisons.