Figure 9. Effects of aging and PASK deficiency on the expression of FoxO3a gene and p53, p21, PCNA proteins and the length of telomeres. Real-time PCR was used to analyze the expression of FoxO3a (A) and p53 (B) mRNA levels. The results were measured in the livers of non-fasted (NON-FASTED) and 24-h fasted (FASTED) young (3-5 months) and aged (18-20 months) wild-type (WT) and PASK-deficient (Pask-/-) mice. The mRNA levels of different genes were normalized by the mRNA of β-actin used as housekeeping gene. Immunoblot analysis of p53 (C), p21 (D), PCNA (E) in livers from young and aged WT and Pask-/- mice. Liver lysates from non-fasted (NF) and 24-h fasted (F) mice were processed for western blot analysis. (C, D) The value obtained in 18-20-months-old non-fasted aged WT mice was taken as 1. (E, F) The value obtained in 3-5-month-old non-fasted WT mice was taken as 1. Bar graphs represent the means ± SEM of the densitometric values normalized by total protein detected by Stain-Free (TOTAL PROTEIN) (Supplementary Figure 3) n = 4-5 animals per condition. In addition, telomere length (F) was measured in livers from young and aged WT and Pask-/- mice. $P < 0.05, $$P < 0.01, $$$P < 0.001 3-5 months vs. 18-20 months; * P < 0.05, ** P < 0.01 *** P < 0.001 WT vs. Pask-/-; ##P < 0.01, ###P < 0.001 non-fasted vs. fasted.