Cardiomyocyte BRAF knockout inhibits interstitial but not perivascular fibrosis induced by AngII in male mouse hearts
Male BRAFfl/fl/Cre+/− (BRAF) or wild-type (WT) mice were treated with CO or tamoxifen in CO (Tx) 4 days before minipumps were implanted to deliver acidified PBS (AcPBS) or 0.8 mg/kg/d AngII in AcPBS (AngII) for 7 d. (A,B) Picrosirius red staining of mouse heart sections showing short axis views of the whole heart (A) with enlarged sections (B) from the same views (the red stain shows accumulation of fibrotic material). Representative (average) images are shown for mice treated with CO/AcPBS (i), Tx/AcPBS (ii), CO/AngII (iii) and Tx/AngII (v). Additional images are shown for the most severe degree of fibrosis with CO/AngII (iv) and Tx/AngII (vi). (C) Quantification of the degree of fibrosis. This was scored as: 1 = the least amount of fibrosis; 2 = low level fibrosis; 3 = high level fibrosis in at least one area of the myocardium; 4 = high level fibrosis throughout the myocardium (half scores were used). Statistical analysis used two-way ANOVA with Holm-Sidak’s post-test. Statistically significant values (P<0.05) are in bold type.