Fig. 2: Global and tissue-specific miRNA expression patterns with aging.

a, Heatmap of Spearman rank correlation values of the intersection of miRNAs expressed in all tissues, color coded for positively correlated in blue (r > 0.5), negatively correlated in red (r < −0.5) and not correlated in white (−0.5 < r < 0.5). b, Heatmap of miRNAs (anti-) correlated with age in at least two tissues, colored by number of tissues (anti-) correlated and divided into miRNA positively and negatively correlated with age. c, Heatmap for the count of deregulated miRNAs in each tissue at each subsequent timepoint. Deregulated miRNAs are determined by calculating the foldchange of all later timepoints versus 3 months of age and miRNA with foldchanges <2/3 or >3/2 are considered deregulated. d, Volcano plot of all miRNAs expressed in brain, log₂(FC) versus −log₁₀(P values) (two-sided t-test) calculated between mice aged 3 months and all later timepoints with comparisons for 12 months (light red) and 18 months (light blue) highlighted. e, Whole organism miRNA trajectory clustering—z-scored trajectories of each expressed miRNA in each tissue over the entire lifespan of the mice were calculated. These trajectories were grouped into 20 clusters. Three clusters are displayed as examples, showing tissue-specific miRNA signatures. Cluster 2 is composed of 50.1% miRNAs originating from skin, cluster 9 of 61.2% miRNAs from brain and cluster 13 of 70.6% miRNAs from BAT. f, Cluster 20 of the whole organism miRNA trajectory clustering—the cluster contains two global aging miRNA, miR-29a-3p from ten different tissues and miR-29c-3p from eight different tissues.