Figure 4.

TRB3 overexpression in skeletal muscle facilitates the protein degradation pathways, including ubiquitin-proteasomal and autophagy-lysosomal systems after 48 h of food deprivation. TA muscles from groups with free access to food (Fed) and food-deprived groups (FD) in both genotypes were used for analysis. A–C) The phosphorylation of Akt (A), FOXO1 (B), and FOXO3a (C) were determined by Western blot analysis. D) mRNA expression of atrogenes was measured by RT-PCR in both genotypes. E, F) Protein expression of atrogin-1 (E) and MuRF-1 (F) was determined by Western blot analysis. G, H) The markers of autophagy-lysosomal protein degradation, including p62 (G) and LC3B (H), were analyzed after 48 h of food deprivation. A.U., arbitrary unit; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; pFOXO1^S256, forkhead box O family 1; pFOXO3a^S253, forkhead box O family 3a. Data are the means ± sem (n = / group). *P < 0.05, **P < 0.01, ***P < 0.001 vs. Fed. ^#P < 0.05, ^##P < 0.01 vs. WT.