FIGURE 1.

Circadian expression of Bmal1 protein and response to feeding-fasting signals in skeletal muscle. A, Immunoblot analysis of Bmal1 protein together with PDK4 in different muscle types Tibialis Anterior (TA), Soleus, diaphragm, and heart, liver, white adipose tissue (WAT) in normal mice. Pooled protein samples of n = 5–6 mice/group were used. B, Fasting and refeeding regimen with sample collection at the same circadian time of the day at 12 PM. Fasted group of mice was withheld food from 8 to 12 PM the following day and the refed group was fasted from 4 PM to 8 AM the next day followed by refed for 4 hours from 8 AM to 12 PM. The time of lighting was maintained with lights on at 7 AM (ZT0) and off at 7 PM (ZT12). C, Bmal1 protein level in distinct tissues in response to fasting and refeeding. D, Bmal1 mRNA expression during fasting and refeeding in TA muscle and liver as analyzed by RT-qPCR (n = 5–6/group). E and F, Bmal1 and Rev-erbα protein (E) or mRNA level (F) in response to insulin (10 ug/mL), forskolin (10 uM) treatment using differentiated myotubes (n = 3). G and H, Bmal1 and Rev-erbα mRNA (G) or protein level (H) in response to glucose or BSA-conjugated palmitate treatment in myotubes at an indicated concentration (n = 3)