(A) PDE10A2 mRNA levels assessed by qPCR in mouse heart tissues from mice with 8 weeks of TAC or sham operation, normalized to GAPDH. n=7 for PDE10A-WT/Sham; n=11 for PDE10A-WT/TAC; n=4 for PDE10A-KO/Sham; and n=12 for PDE10A-KO/TAC. (B) PDE10A protein levels measured by western blotting in mouse tissues from mice with 8 weeks of TAC or sham operation, bar graph shows the average of n=4 WT/Sham; n=4 WT/TAC. (C) PDE10A cAMP-hydrolyzing activity in mouse heart tissues from mice with 8 weeks of TAC or sham operation; n=5 for WT/Sham; and n=5 for WT/TAC. (D) Immunohistochemistry staining of PDE10A in myocardium of WT mouse hearts with sham or TAC operation for 8 weeks. Arrows indicate activated CFs. Asterisks indicate CMs. Scale bars: 100 μm. Similar results were obtained from 3 pairs of tissue samples. (E) PDE10A2 mRNA levels assessed by qPCR in mouse adult CMs isolated from PDE10A-WT and -KO mice and stimulated with Ang II (100nM) or vehicle for 72 h, normalized to GAPDH; n=5 replicates from 4 PDE10A-WT mice and n=4 replicates from 4 PDE10A-KO mice. (F) PDE10A protein levels measured by western blotting in CMs isolated from PDE10A-WT mice and stimulated with Ang II (100nM) for 72 h; bar graph shows the average of n=4 replicates from 3 hearts. (G) PDE10A2 mRNA levels assessed by qPCR in CFs isolated from PDE10A-WT and -KO mice and stimulated with TGF-β (10ng/ml) or vehicle for 24 h, normalized to GAPDH; n=5 replicates from 4 PDE10A-WT mice and n=8 replicates from 5 PDE10A-KO mice. (H) PDE10A protein levels measured by western blot in CFs isolated from PDE10A-WT mice and stimulated with TGF-β (10ng/ml) for 24 h; bar graph shows the average of n=3 replicates from 3 hearts. All data represents the mean ± SEM. Statistics in A, E and G were performed using a two-way ANOVA and Holm-Sidak post-hoc test. Statistics in B-C, F and H were performed using a student t-test. *P < 0.05, ***P < 0.001, ****P < 0.0001.