Mice lacking growth-associated protein 43 develop cardiac remodeling and hypertrophy

Figures

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  Fig. 1. GAP43 expression and localization in the heart. a Representative western blots of GAP43 expression in hearts from WT newborn mice at 24 h after birth (heart 24 h) or from WT adult mice (heart 3 months), and in brain from WT mice at 24 h after birth (brain 24 h). Total proteins were loaded onto SDS-PAGE at 40 μg for heart homogenates and 2 μg for brain. The same membrane was detected also for anti-GAPDH antibody as loading control. b Representative images of adult papillary muscle fibers immunostained to detect GAP43 and α-actinin localization. The arrows and dashed lines indicate immunofluorescence for GAP-43, which reveals a dotted pattern depicting lines across the length of the fiber. Scale bar, 5 µm. c Distances between GAP43-positive spots. Data are expressed as mean ± SEM

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  Fig. 2. Cardiac mass index in WT and GAP43−/− mice. a Comparison of body weights (BW) between WT (1.453 ± 0.043 g, N = 49) and GAP43−/− (1.342 ± 0.062 g, N = 18) newborns. b Heart weights (HW) of WT (0.014 ± 0.001 g, N = 49) and GAP43−/− (0.020 ± 0.003 g, N = 18) newborns. c Cardiac mass index was calculated as the ratio between the heart weight and the body weight of the same WT or GAP43−/− newborn mouse. All data are expressed as mean ± SEM. ∗p < 0.05 versus WT; ∗∗p < 0.01 versus WT

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  Fig. 3. Morphometric analyses in hearts from WT and GAP43−/− mice. a Representative images of transversal sections of WT and GAP43−/− hearts stained with hematoxylin–eosin (scale bar, 1 mm). b Measurement of left wall thickness. c Measurement of septum thickness. d Measurement of left chamber free area. e Representative images of confocal acquisition of cross-sections obtained from the left ventricular wall and stained with wheat germ agglutinin conjugated with tetramethyl rhodamine and pseudocolored in green (scale bar, 10 µm). f Quantitative analyses of cross-sectional area, tracing the fluorescent WGA-TRITC signals (for each section, at least 40 cardiac fibers were measured). g Representative images of WT and GAP43−/− heart sections stained with Masson’s trichrome (scale bar, 20 µm). h Quantitative analysis of blue staining percentage, which indicates the percentage of collagen in WT and GAP43−/− hearts. For panels b, c, d, f, and h, data are expressed as the mean ± SEM from three independent experiments. ∗p < 0.05 versus WT; ∗∗p < 0.01 versus WT; ∗∗∗p < 0.001 versus WT

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  Fig. 4. Myosin expression levels. a Representative western blot of MYH and the corresponding densitometric analyses in heart samples from WT and GAP43−/− mice; b Representative western blot of MYH7 and the corresponding densitometric analyses in heart samples from WT and GAP43−/− mice. The densitometric analyses are plotted as the ratio between the optical density (OD) × mm2 of each band and OD0× mm2 of the corresponding GAPDH band. Data in in the graphs are expressed as the mean ± SEM from three independent experiments. ∗p < 0.05 versus WT