Figure 3. Tip60 depletion preserves function and reduces scarring in infarcted mouse hearts.

A, experimental timeline. Mice were injected with tamoxifen on three consecutive days beginning three days after induction of MI on day 0. Echocardiography was performed at the indicated intervals up to 28 days post-MI when hearts were removed for histological assessment. B-D, indices of LV function. Fractional shortening (FS), fractional area change (FAC), and ejection fraction (EF) were preserved in Tip60-depleted (Kat5^Δ/Δ) hearts (N=8) but not in Kat5^f/f controls (N=5); additional parameters are shown in Supplemental Table 4. *P<0.05 vs. Kat5^f/f and ^†P<0.05 vs baseline value on day 0. Echocardiography data were analyzed by two-way repeated measures ANOVA followed by Dunnett’s (effect of time) and Bonferroni’s (effect of genotype) multiple comparisons. E, Kaplan-Maier curves indicating a trend (P=0.072) toward improved survival of Tip60-depleted mice. F, representative trichrome-stained cross-sections taken at 0.5 mm intervals; blue stain shows area of the scar. Infarct scar size (right) was quantified by measuring area and midline length below the ligation site. N=10 for Kat5^f/f and N=12 for Kat5^Δ/Δ. Data are reported as Mean ± SEM and compared by unpaired, two-tailed Student’s t tests with Welch’s correction.