Fig. 2.

Amount of Mdm2 protein (a) and its mRNA transcripts (c) in hippocampus of 4- and 24-month-old IL-6-deficient (IL-6KO) and wild type control (WT) mice. Level of mRNA expression was defined as log2(FC), where FC stands for fold-change difference in mRNA level between indicated groups. Bars represent mean ± SEM obtained from six animals in each group. There were no significant differences in the Mdm2 protein level in young adult mice, and aging was associated with decrease in its amount, which was statistically significant in IL-6-deficient mice in comparison with age-matched WT controls (**p < 0.01, ANOVA with Bonferroni post hoc). GLM analysis revealed significant influence of age on the Mdm2 protein abundance (p < 0.001). (c) In both 4- and 24-month-old IL-6-deficient mice Mdm2 mRNA level was significantly higher in comparison with respective control WT animals (*p < 0.05), and aging was associated with significant decrease in Mdm2 mRNA in WT controls (*p < 0.05, Wilcoxon signed rank test). According to GLM analysis the expression of Mdm2 mRNA was both genotype- and age-dependent (p < 0.005 and p < 0.001, respectively). b Representative immunoblot for Mdm2 protein is shown together with α-tubulin as a loading control. M molecular weight marker