Fig. 2: Metabolism of brain aging is reflected in the transcriptome and proteome.

A KEGG pathways of the green-yellow module of WGCNA from mouse cortex. B, C Abundance of Mitocarta3.0 genes in the green-yellow (p = 0.0004) (B), cyan (p < 0.0001), and salmon (p < 0.0001) (C) modules. Signficance determined by two-sided Fisher’s exact test. D RT-qPCR detection of PGC-1α expression cortex of male mice at 10 months, 20 months, and 30 months old (n = 5 mice/ age group). Boxplot represents median, 25th and 75th percentiles, and whiskers extend to min and max. Significance determined by Wilcox test (individual group comparison) and Kruskal–Wallis test. E, F Volcano plots displaying proteins quantified. Statistically significant proteins determined by Tukey’s HSD test are highlighted in purple. G Venn diagram showing overlap between differentially expressed proteins in the 30-month-old or 20-month-old cortex compared to the 10-month-old. H, I KEGG pathways enriched in the 30-month-old cortical proteome (H) and 20-month-old cortical proteome (I). Only pathways with greater than 6 proteins were plotted. J Venn diagram showing the overlap between enriched KEGG pathways in the 30-month-old or 20-month-old cortex compared to the 10-month-old cortex. K Network identified by String analysis. Proteins are colored based on biological pathway—mitochondrial ETC (yellow), ribosome (red), protein trafficking (brown), RNA splicing (orange). L Table displaying common pathways between the 20v10 and 30v10 comparison and if they are activated or repressed compared to the 10-month-old. n = 5 mice/ age group.