Pulmonary hypertension is exaggerated in Kcnk3-mutated rats with AAC. (A) Representation of the record of right ventricular pressure (RVP in mmHg) using right heart catheterization. (B) Quantification of RVSP (in mmHg) (SHAM; WT = 5, Kcnk3Δ94Ex1/Δ94Ex1 = 8, AAC; WT = 13, Kcnk3Δ94Ex1/Δ94Ex1 =19 rats). (C) Correlation (Spearman) between RVSP and LAAmax in AAC-WT (n = 3), AAC-Kcnk3Δ94Ex1/+ (n = 6), and AAC-Kcnk3Δ94Ex1/Δ94Ex1 (n = 5) rats. (D) M-mode echocardiographic determination of RV free wall thickness (RVFW) and tricuspid annular plane systolic excursion (TAPSE, upper panels). Representative images of RV cardiomyocytes size (WGA staining) and RV interstitial collagen deposition (Sirius red staining, lower panels). Vertical bars, 0.5 cm (M-Mode) and horizontal bars represent 100 ms, 50 μm (WGA staining), and 100 μm (Sirius red). (E) First panel: RVFWT; and second panel: TAPSE from Sham-WT (n = 7), Sham-Kcnk3Δ94Ex1/Δ94Ex1 (n = 7–8), AAC-WT (n = 8), and AAC-Kcnk3Δ94Ex1/Δ94Ex1 rats (n = 9). Third panel: RV cross-section area; and fourth panel: analysis of the percentage of RV interstitial collagen staining from Sham-WT (n = 5), Sham-Kcnk3Δ94Ex1/Δ94Ex1 (n = 5), AAC-WT (n = 5), and AAC-Kcnk3Δ94Ex1/Δ94Ex1 rats (n = 5). (F) RV/tibia length ratio and Fulton index from Sham-WT (n = 5–8), Sham-Kcnk3Δ94Ex1/Δ94Ex1 (n = 9–11), AAC-WT (n = 9–14), and AAC-Kcnk3Δ94Ex1/Δ94Ex1 rats (n = 14–17). (G) Relative mRNA expression (2−ΔΔCt) of Myh6, Myh7, Nppa, Nppb, Col1a1, Periostin, and IL-6 (heatmap representation of the mean) in RV from Sham-WT (n = 6), Sham-Kcnk3Δ94Ex1/Δ94Ex1 (n = 5), AAC-WT (n = 6), and AAC-Kcnk3Δ94Ex1/Δ94Ex1 rats (n = 7). Experiments were normalized by 18S mRNA and analysed using ΔCt values (for a full statistical analysis refer to the supplemental material). Data are represented as scatter dot plots, with mean ± SEM. Experiments were analysed using two-way ANOVA followed by Sidak’s post hoc test after Kruskal–Wallis test. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. RVSP, RV CSA, RV Fibrosis, RV/TL, and Fulton were not normally distributed and were log-transformed prior to statistical analysis.
