Fig. 3

Metformin treatment induces PP2A expression, inhibits mTOR and activates AMPK in the brain of P301S mice. Protein levels of PP2A, GSK3β, pGSK3β, mTOR, S6, phospho-S6 (pS6), AMPK and phospho-AMPK (pAMPK) were analyzed by western blot in the brain of 5 month old P301S mice treated with or without metformin for 4 months. a Western blot of PP2A in the cortex. Tubulin was analyzed as a loading control. b-c Quantitative analysis of PP2A in the cortex (b) and hippocampus (c). In panel b: Ctr, n = 10; Met, n = 12. In panel c: Ctr, n = 9; Met, n = 11. d-e Quantitative analysis of p[S9]GSK3β (d) and GSK3β (e) in the cortex. Ctr, n = 13; Met, n = 12. f Western blot of mTOR in the cortex. Actin was analyzed as a loading control. g Quantitative analysis of mTOR protein expression. Ctr, n = 7; Met, n = 7. h Western blot of pS6 and S6 in the cortex. Tubulin was analyzed as a loading control. i-j Quantitative analysis of pS6 (i) and S6 (j). n = 7 / group. k Western blot of pAMPK and AMPK in the cortex. Tubulin was analyzed as a loading control. l-m Quantitative analysis of AMPK (l) and pAMPK (m). Panel l-m: Ctr, n = 10; Met, n = 12. Protein expression levels were normalized to tubulin or actin as indicated in the graphs. Levels of phosphorylated proteins were normalized to the total respective protein. In all graphs, bars represent the average ratio ± SEM. *p < 0.05, **p < 0.01, Student t-test