Fig. 7Figure 8
Cardiac-specific PDE4D-knockdown activates mitophagy and protects against TAC-induced cardiac hypertrophy and heart failure . A, 30 days after TAC or sham surgery, αMHC-Cre+/PDE4D-flox/+ mice were subjected to a single intraperitoneal injection of tamoxifen (100 mg/kg/day) for 5 consecutive days to induce PDE4D ablation in the heart (PDE4D hCKO ). Littermate PDE4D-WT with the same dose of tamoxifen as controls. The mice were sacrificed 12 days after tamoxifen injection. B and C, Ejection fraction ( B ) and fractional shortening ( C ) were measured by echocardiography at 6 weeks after TAC; n = 8 mice per group. D, Cardiac cross-sections were stained with hematoxylin-eosin or WGA to examine heart morphology and measure myocyte CSA; n = 100 cells per heart and n = 3 mice per group. Scale bar, 50 μm. The myocardial apoptosis was detected by TUNEL staining, 2 random fields per heart; n = 3 mice per group. Scale bar, 50 μm. ROS levels were determined by DHE fluorescence intensity in t