Fig. 2.

VDR^−/− muscles are characterized by an increase in atrophic gene expression, a decline in mTOR pathway components, and a block in autophagic gene expression. a The soleus and TA muscles from 6-week-old WT and V mice were assessed for levels of Myostatin transcript by qRT-PCR. Myostatin transcript levels in the soleus and TA muscles of V mice are normalized to those in WT (n = 6) (*p < 0.05). Myostatin is upregulated in the soleus and TA muscles of V compared to WT. b Graph showing the quantitation of western blot analysis of lysates from dissected soleus muscles (Fig. 1b) and TA muscles (Fig. 1c) from WT and V mice at 6 weeks of age probed for p-Smad3 antibody (n = 5) (**p < 0.01, ***p < 0.005). GAPDH serves as a loading control. c–f Representative western blot analysis of lysates from dissected soleus muscles (Fig. 1b) and TA muscles (Fig. 1c) from WT and V mice at 6 weeks of age probed for p-p70S6K antibody and S6K antibody (c, d) and p-rpS6 antibody and total rpS6 (e, f). Graphs below each blot show ratios of p-p70S6K to total S6K and p-rpS6 to total rpS6, respectively (n = 5) (**p < 0.01, ***p < 0.005). GAPDH serves as a loading control. g, h Soleus and TA muscles from 6-week-old WT and TA muscles were assessed for known markers of atrophy, Foxo3, Murf1, and C/EBP δ transcripts by qRT-PCR. While C/EBP δ was upregulated in both muscles sets, Foxo3 and Murf1 showed differential fiber-type-specific expression (n = 5) (**p < 0.01, ***p < 0.005). i–j Soleus and TA muscles from 6-week-old WT and TA muscles were assessed for known markers of autophagy, LC3b and Bnip3 transcripts, by qRT-PCR. Both transcripts were downregulated in V muscles compared to WT muscles. All transcript levels in V are normalized to those in WT (n = 5) (**p < 0.01, ***p < 0.005)