mTOR pathway activity, autophagy and protein ubiquitination in brain of ZDF (zucker diabetic fatty rat). (A) Increased expression of mTOR and its phosphorylated form in ZDF detected by an antibody raised against phosphorylation on serine 2448. (B) Increased S6 ribosomal protein (S6) and its phosphorylated form (p-S6) in ZDF. (C) Increased mTOR activity in ZDF. (D) Increased S6 protein activity in ZDF. (E) Increased expression of LC3-I and the decrease in LC3-II levels in ZDF. (F) Autophagy levels are lower in ZDF compared to Lean as shown by LC3-II/LC3-I ratio. (G) Increased levels of mono- and polyubiquitinated proteins in ZDF. Insets: typical examples of Western blot data showing protein of interest (upper part) and β-actin (lower part). Data are Means ± SEM (n ≥ 5 per group), * <0.0001 (difference to control gray bars in each group); unpaired t-test. Western blot expression is normalized to β-actin; lanes of western blot insets are in the same order as in the X-axis.