Figure 4. HSA^LR muscles display perturbed response of autophagy to caloric and pharmacological treatments.

(A) Expression of autophagy-related genes is efficiently upregulated after 45 hours of starvation (St45) in HSA^LR TA muscle. Data are normalized to Actn2 levels (Fed, n = 4; St45, n = 4 Ctrl and 3 HSA^LR). Data are relative to control fed mice and represent mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, 2-way ANOVA with Tukey’s multiple comparisons test correction. (B) Immunoblots reveal limited switch from LC3I to LC3II in HSA^LR muscle upon 45 hours of starvation (St45) compared with controls (Ctrl). Samples were run on the same gel but were noncontiguous. For LC3II/LC3I quantification, see Supplemental Figure 4B. (C) Levels of the inhibited phosphorylated form of ULK1 (Ser^P757) remain slightly higher upon starvation in HSA^LR muscle, compared with control (Ctrl) muscle. For quantification, see Supplemental Figure 4C. (D and E) Immunoblots for LC3 show blunted induction of LC3II upon rapamycin (Rapa, D) or metformin (MetF, E) treatments, compared with controls (Ctrl). For LC3II/LC3I quantification, see Supplemental Figure 4, D and E. Samples were run on the same gel but were noncontiguous.