Evaluation of the transverse aortic constriction model in ICR and C57BL/6J mice

Figures

• 

  FIGURE 1. Survival after transverse aortic constriction (TAC) in ICR and C57BL/6J mice. (A) Representative Doppler flow velocity waveforms (lower panel) obtained from the aortic arch (upper panel) after TAC surgery in ICR and C57BL/6J mice. Inclusion criteria: Velsham ≤ 800 mm/s, VelTAC ≥ 2400 mm/s. (B) Aortic flow velocity after TAC surgery from ICR and C57BL/6J mice. (C) Kaplan-Meier survival curve analysis of ICR and C57BL/6J mice after TAC surgery. N = 21, 39 for sham and TAC group of ICR, 23, 37 for sham and TAC group of C57BL/6J, respectively. Ns: not significant.

• 

  FIGURE 2. Echocardiography at 1, 2 and 4 weeks post-TAC or sham surgery in ICR and C57BL/6J mice. (A,B) Representative ultrasound images of left ventricle (short-axis, at the level of the papillary muscles) from ICR and C57BL/6J mice: (A) in B-mode; (B) M-mode. (C–H) Averaged parameters obtained from analysis of echocardiograms: (C) Left ventricular anterior wall thickness at end-diastole (LVAWd); (D) LV posterior wall thickness at end-diastole (LVPWd); (E) Relative Wall thickness (RWT) = (LVAWd + LVPWd)/LVIDd×100%. (F) LVID at end systole (LVIDs); (G) Ejection fraction (EF); (H) Fractional shortening (FS); Values represent mean ± SEM, N = 6–9 per ICR group,N = 7–9 per C57BL/6J group. *p < 0.05, **p < 0.01.

• 

  FIGURE 3. Statistical results of Organ coefficients at 1, 2 and 4 weeks post-TAC surgery or sham in ICR and C57BL/6J mice. (A) Heart weight. (B) Body weight. (C,D) Heart weight normalized to body weight (HW/BW) or tibia length (HW/TL). (E,F) Lung weight normalized to body weight (LW/BW) or tibia length (LW/TL). Data are shown as mean ± SEM, N = 6–8 per ICR group, N = 6–9 per C57BL/6J group. *p < 0.05, **p < 0.01 vs. their specific sham group.

• 

  FIGURE 4. Gross samples and shape analyses of mouse hearts at 1, 2 and 4 weeks post-TAC or sham surgery in ICR and C57BL/6J mice. (A) Representative photos of whole heart. Scale bar is 1 mm. (B) Ventricle area (left and right ventricle) and (C) ventricle perimeter obtained from heart photos. (D) Shape index (area over perimeter squared). Data are shown as mean ± SEM, N = 6 per ICR group, N = 6–8 per C57BL/6J group. *p < 0.05, **p < 0.01 vs. their specific sham group. # p < 0.05, ns denotes not significant compared between 2w and 4w in TAC group.

• 

  FIGURE 5. Histological alterations of mouse hearts at 1, 2, and 4 weeks post-TAC surgery in ICR and C57BL/6J mice. (A) Representative images of H&E-stained heart sections (upper panel), scale bar = 1 mm; Masson trichrome-stained left ventricle tissues (middle panel), red stain denotes muscle fibers while blue stain denotes collagen. White scale represents 50 μm; Wheat-germ-agglutinin (WGA)-stained cardiomyocytes border (lower panel), scale bar = 20 µm. All images obtained from ICR mice. (B) Quantitative analysis of interstitial fibrotic area measured from Masson-stained pictures and (C) Cardiomyocyte cross-sectional area measured from WGA-stained pictures in ICR mice. (D–F) The same indicators of (A–C) in C57BL/6J mice. N = 3 per group per staining. Quantitative data are shown as mean ± SEM, **p < 0.01 vs. sham.

• 

  FIGURE 6. Behavior observation at 4 weeks after TAC in ICR and C57BL/6J mice. (A) Heatmap of locomotor activity in cage and resistance when gripped. Score: normal = 0, decrease = −1, increase = 1. (B) Respiration rate in cage or gripped and reactivity to grab. Score of respiration: 5 = normal; 4 = slightly incomplete/fast and shallow, bradypnea (breathing either fast and shallow or slow); 3 = moderately incomplete/rapid breathing, difficulty breathing (breathing very fast and shallow or very shallow and laboured in appearance); 2 = severely incomplete/wheezing, breathing with mouth open (wheezing or breathing with mouth open); 1 = weak breathing (breathing very little). Score of reactivity to grab: 5 = very easy (sits and allows itself to be picked up); 4 = easy/normal (does not resist); 3 = somewhat difficult (stands); 2 = difficult (cringes and becomes rigid or runs around and is difficult to grab); 1 = very difficult (attacks). (C) Grip strength measured by a rats/mice grip strength meter. (D) Total move distance calculated from open field observation in 5 min. N = 6 each in (A–D), quantitative data are shown as mean ± SEM, *p < 0.05. (E) Percent survival from stress like anesthesia,…

• 

  FIGURE 7. Pathological gene-expression alteration in heart tissue of ICR and C57BL/6J mice 4 weeks post-TAC. (A) Heatmap of differentially expressed genes in C57BL/6J mice by RNAseq. CS: C57BL/6J sham; CM: C57BL/6J model. N = 3. (B) Real time quantitive PCR verification of the expression levels of 15 selected genes in both ICR and C57BL/6J mice. Relative mRNA levels are normalized to Gapdh, values are shown as mean ± SEM, N = 3 each. *p < 0.05, **p < 0.01 vs. their own sham.