Fig. 1

Metformin delays astrocyte senescence in MPTP-induced PD model. A, B Movement distance within 5 min was recorded by open field test (n = 8 animals for each group). C the time taken to descend a pole (Time-total) was recorded in pole test (n = 8 animals for each group). D Time on the rod was measured by the rotarod test (n = 9 animals for each group). E Heatmap of relative mRNA levels of SASP as indicated in SNpc (n = 3 animals for each group). F–K qPCR measurement of the levels of IL-1α (F), IL-1β (G), MMP3 (H), MMP9 (I), IL-6 (J) and p16^Ink4a (K) in the SNpc (n = 6 animals for each group). L Representative double-immunostaining for lamin B1 and astrocytic marker GFAP, DA neuron marker TH or microglia marker IBA-1 in the SNpc. DAPI stains nucleus (blue). White arrow: high level of lamin B1, yellow arrow: low level of lamin B1. M–O Quantification of lamin B1 immunofluorescence intensity in GFAP⁺ astrocytes (M), TH⁺ DA neuron (N), and IBA-1⁺ microglia (O) in the SNpc (n = 6 animals for each group). P Quantification of p16 immunofluorescence intensity in GFAP⁺ astrocytes in the SNpc (n = 6 animals for each group). Q Representative double-immunostaining for p16 (red) and astrocytic marker GFAP (green) in the SNpc. DAPI stains nucleus (blue). The data shown are the mean ± SEM. One-way ANOVA with Tukey’s post-hoc tests were used. *p < 0.05, ***p < 0.001, NS: no significant