CLOCK and diabetes mellitus: Our results showed that diabetes upregulated the expression of CLOCK (p < 0.01; Figure 3A,B) and apoptosis (p < 0.05; Figure 7) and downregulated the expression of OPA1 (p < 0.001, Figure 5A,B), and the expression of CLOCK was negative correlated with the expression of OPA1, suggesting that SIRT3 may be involved in the regulation between CLOCK and OPA1.