Fig 2: Effects of Chronic VNS on Power Spectral Density of Heart Rate, Hemodynamic Variables, and Plasma BNPValues are mean ± SEM. Differences were tested by using 1-way analysis of variance, followed by post hoc Tukey-Kramer tests. *p < 0.05 and **p < 0.01 vs. CTRL. †p < 0.05 and ‡p < 0.01 vs. SS. (A) Representative traces of power spectral density of heart rate in CTRL, SS, and VNS in rats at 5 weeks after SU5416 injection. The frequency range of 0.04–0.73 Hz was defined as low frequency (LF) and 0.73–2.0 Hz as high frequency (HF). The HF of HRV that represents parasympathetic nerve activity is lower in SS than CTRL but is higher in VNS than in SS. (B to G) Mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index (CI), right ventricular end-diastolic pressure (RVEDP), and maximum first derivation of right ventricular pressure normalized by RVEDP (Max +dP/dt/RVEDP) are shown. VNS significantly reduces mPAP and improves right ventricular function. CTRL, n = 5; SS, n = 6; and VNS, n = 6. BNP = brain natriuretic peptide; other abbreviations as in Figure 2.

Fig 3: MN-Gal patch decreased infarct scar extension and expansion and protected from myocardial hypertrophy in a rat model of MI. (a–c) HW/BW ratio, HW/BW ratio, and lung wet/dry weight ratio on 28 days after MI. (d) Plasma BNP level at the endpoint. (e) Representative images of WGA staining (scale bars: 50 µm (upper) and 10 µm (lower). (f) CAS shows the relative cardiomyocyte size. n = 5 animals per group. (g) H&E-stained and Sirius red-stained images of the heart tissue were collected at the endpoint (scale bar: 2 mm and 100 µm). (h) Schematic image revealed the definition of BZ and infarcted zone of a rat model of MI. The BZ area was defined as the total fibrotic area minus the infarct zone area in which LV thickness became thinner. (i) Infarction wall thickness, (j) fibrosis area to LV area ratio, and (k) BZ area to LV area ratio were measured from Sirius red-stained image. n = 5 animals per group. All data were presented as means ± SD. Comparisons between three groups were performed using one-way ANOVA, followed by Tukey’s multiple comparison test. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 between each group and every other group.

Fig 4: Long-term treatment with Alda-1 increases survival rate of CHF in post-MI rats. (A) ALDH2 activity in heart tissue from each group; 3 replicates of each sample, n=4/group. (B) ALDH2 protein expression levels were determined by western blot analysis using ALDH2 specific antibody; GAPDH was used as the loading control. (C) Kaplan-Meier survival curves and Mantel-Cox log rank test were used to examine the survival rates for rats in the Sham, MI and Alda-1 groups. Alda-1 treatment significantly improved 20-week survival rates; P=0.0297, Alda-1 vs. MI. Sham, n=17; MI, n=9; Alda-1, n=15. (D) BNP level in serum from each group; 3 replicates of each sample, n=4/group. ^P<0.01 vs. Sham, ^^P<0.001 vs. Sham, **P<0.001 vs. MI. ALDH2, alcohol dehydrogenase 2; BNP, B-type natriuretic protein; MI, myocardial infarction.

Fig 5: Augmentation of endogenous H2S suppresses ß-adrenergic stimulation-induced hypertrophy in cardiomyocytesa DIC micrographs. H9c2 cells were treated with ISO for 48 h, with or without NaHS pre-treatment for 30 min and imaged utilizing DIC microscope (20X magnification). Scale bar is included in all images. b Box-whisker-plot showing cell surface area (in µm2) for specific groups, calculated using Image J, NIH. c, d The cells were challenged with ISO for 48 h, in the presence or absence of NaHS pre-treatment and culture supernatant collected for estimating secreted levels (in pg/ml) of ANP c and BNP d, utilizing sandwich ELISA. Mean ± S.E. was plotted to obtain the bar graphs shown in the figure. **p < 0.01