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Fig. 2.
Continuous CDK9i treatment reduces macrophage retention on the injured ventricle and impairs cardiomyocyte number expansion. (A) Experimental timeline indicating cardiac injury, continuous CDK9i treatment and imaging time points. (B) Number of ventricular macrophages at 4 hpi, 6 hpi, 24 hpi and 48 hpi with ≤0.3% DMSO vehicle, 50 μM AT7519 (top) or 3 μM FVP (bottom) treatment. Error bars represent s.e.m., n=16 larvae, experimental n=3. **P<0.01, ***P<0.001, ****P<0.0001 (two-way ANOVA and Bonferroni post-hoc test for comparisons between cardiac-injured DMSO vehicle or CDK9i treatment groups). (C) LSFM time-lapse-derived images of cardiac-injured Tg(mpeg1:mCherry) larvae displaying ventricular macrophage presence at 6 hpi (left panel) and 20 hpi (middle panel) with 0.3% DMSO vehicle or 3 μM FVP. LSFM time-lapse images of macrophage (mpeg1:mCherry) migration temporally colour-coded with DMSO vehicle (0.3%) or FVP (3 μM) treatment (right). Start and end timepoint (hpi) for colour code is indicated. Dashed line indicates outline of ventricle. Arrowhead indicates ventricular apex injury site. (D) LSFM images of Tg(myl7:DsRed2-NLS) larvae displaying ventricular cardiomyocytes at 24 h hpt and 48 hpt with 0.3% DMSO vehicle (top), 50 μM AT7519 (middle) or 3 μM FVP (bottom). (E) Number of ventricular cardiomyocytes at 24 hpt and 48 hpt with ≤0.3% DMSO vehicle, 50 μM AT7519 (top) or 3 μM FVP (bottom). Error bars represent s.d., n=25 larvae, experimental n=3. **P<0.01, ***P<0.001 (one-way ANOVA and Tukey post-hoc test performed for comparisons between DMSO vehicle or CDK9i treatment groups). LSFM fluorescence images were acquired in 3D and maximum intensity projections are used for time point display (C,D) or temporal colour code analysis (C). Scale bars: 50 μm.