Figure 3.

Sex-specific phenotype of the cardiac fibroblast population in response to 5-aminoimidazole-4-carboxamide riboside (AICAR) treatment. A: staining of total collagen type I α (green) or degraded collagen (red) was performed on cardiac sections from controls and AICAR-treated male and female old mice. Nuclear counterstaining with DAPI (blue) (n = 3). Scale bar = 100 μm. B: graph shows level of hydroxyproline in the myocardium of control or AICAR-treated female and male mice (n = 6–13 samples/group). C: immunostaining for periostin (green) performed on cardiac sections prepared from control and AICAR-treated old female and male mice. Scale bar = 100 μm. D: diagram representing relative level of mRNA for Mmp2, Mmp3, and Mmp28 and Timp1, Timp2, Timp3, and Timp4 as estimated by RT-qPCR in AICAR- or saline-treated female and male hearts (n = 6–9, normalized to the female control group). P value was calculated by a one-way ANOVA among the four cell groups followed by a post hoc analysis (nonparametric Tukey correction). P values were adjusted for multiple comparisons.