Figure 1.

Impact of the mineralocorticoid receptor antagonist eplerenone on profibrotic protein factors and ROS levels in cardiac myofibroblasts. Cardiac myofibroblasts stimulated for 24 hours with leptin (100 ng/mL) in the presence (LEP) or absence (CT) of the mineralocorticoid receptor antagonist (eplerenone; 10⁻⁶ mol/L; L + E) were analyzed. (a) Protein levels of collagen type I, TGF-β, CTGF and galectin-3. (b) Time course of mitochondrial ROS generation in leptin-treated cells labeled with Mitosox: Representative histogram and quantification. (c) Representative microphotographs in cells labeled with DHE analyzed by fluorescence microscopy and quantification of total superoxide anions production induced by leptin in presence or absence of the mineralocorticoid receptor antagonist eplerenone (10⁻⁶ mol/L) (magnification 40X). (d) Mitochondrial ROS production in presence or absence of the mineralocorticoid receptor antagonist eplerenone (10⁻⁶ mol/L): Representative histogram and quantification. Untreated cells (solid black curves) were compared with cells treated with leptin (solid dark grey curves) or with eplerenone + leptin (open grey curves) for 24 h. Scale bar 50 µm. Bar graphs represent the mean ± SEM of 4 assays, in arbitrary units normalized to β-actin. *p < 0.05; **p < 0.01; ***p < 0.001 vs. control (CT). ^†p < 0.05; ^††p < 0.01; ^†††p < 0.001 vs. leptin (LEP). Uncropped images of the blots for Fig. 2a are shown in supplementary Fig. 6.