Figure 3. Validation of age-dependent alterations of representative miRNAs from Meg3-Mirg cluster in cardiac fibroblasts and cardiomyocytes (A, B) The expression of representative miRNAs in cardiac fibroblasts (A) and cardiomyocytes (B) in young, old and very old mice; For each miRNA, the expression is presented relative to the young group. One-way ANOVA for equal variances or Welch’s ANOVA for unequal variances, with Tukey post-hoc test for pairs; * p < 0.05, ** p < 0.01, *** p < 0.001; n=8-10/group. (C) Heat map showing the expression of representative miRNAs normalized to U6 snRNA in cardiac fibroblasts and cardiomyocytes harvested from young, old and very old mice. Note that cardiac fibroblasts showed higher miRNA expression than cardiomyocytes.