Figure 5.

miR-221 Reduces Cardiac Fibrosis and Myofibroblast Activation in the Heart

Rats received 1 mg/kg miR-221 mimics (Nx miR-221) or PBS i.v. injection (Nx Ctrl) for 3 times at day 3, 7, and 14 post-Nx. Hearts were harvested by the end of 8 weeks. Middle sections of 1/3 the heart were used for histological analysis. (A) Picro-sirius red staining of the heart was performed as follows (i) cross-section, scale bar = 2 mm; (ii) zoom-in images, scale bar = 200 μm; (iii) quantified percentage of fibrosis with ImageJ. (B) Heart weight (HW) normalized by tibial length (TL). (C) (i) Immunofluorescence staining with α-SMA (green) and DAPI (blue), Scale bar = 100 μm; (ii) Quantification of the α-SMA⁺myoFBs expressed as percentage of cells. Values were expressed as mean ± SD. #p < 0.05 versus Nx Ctrl; ∗p < 0.05, ∗∗p < 0.01 versus Sham by by one-way ANOVA and Bonferroni post hoc analysis. n = 6 per group.