Derangements and Reversibility of Energy Metabolism in Failing Hearts Resulting from Volume Overload: Transcriptomics and Metabolomics Analyses

Figures

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  Figure 1. Characterization of rats with volume overload (VO) or with correction of VO. Echocardiography (A) and hemodynamic assessment (B) of rats with ACF-induced VO in the compensated hypertrophic (CH) and heart failure (HF) phases, VOed rats with correction of VO in the CH (CHCOV) and HF phases (HFCOV), and the corresponding sham controls. (C) Hematoxylin and eosin-stained sections of the left ventricles in different VO phases. The size of cardiomyocytes quantified by the cross-sectional area was compared between VOed rats and corresponding sham controls. n = 6 per group. White, light gray, and dark gray columns represent sham controls, VOed rats, and VOed rats with correction of VO, respectively. *, **, and *** denote p < 0.05, p < 0.01, and p < 0.001, respectively. LVEDD, left ventricular end-diastolic diameter; PW, posterior wall.

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  Figure 2. Transcriptomics analyses of rats with volume overload (VO) or with correction of VO. Pathway enrichment analyses of the differentially expressed genes (fold change > 1.5 and p < 0.05; ranked by −log [p value] of each pathway) in VOed rats in the heart failure (HF) phase (A) and in VOed rats with correction of VO in the HF phase (HFCOV) (B); Venn diagrams (C) illustrating the number of differentially expressed genes involved in glucose and lipid metabolism in VOed rats in the compensated hypertrophic (CH)and HF phases and VOed rats with correction of VO in the CH (CHCOV) and HF phases (HFCOV). n = 4 per group.

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  Figure 3. Differential expression of genes (fold change > 1.5 and p < 0.05) involved in glycolysis (A), hexosamine biosynthetic pathway (B), and fatty acid oxidation (C) in volume-overloaded rats in the heart failure (HF) phase and in volume-overloaded rats after correction of volume overload in the HF phase (HFCOV). The ovals in the maps represent enzymes in each metabolic pathway, with red and green denoting upregulation and downregulation of gene expression, respectively. n = 4 per group.

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  Figure 4. Changes in the myocardial levels of (A) glycolysis intermediates, (B) hexosamine biosynthetic pathway intermediates, (C) acylcarnitines, and (D) tricarboxylic acid cycle intermediates in volume-overloaded rats in the compensated hypertrophic (CH) and heart failure (HF) phases and in volume-overloaded rats with correction of volume overload in the CH (CHCOV) and HF phases (HFCOV) compared to those in the corresponding sham controls. In each z-score plot, the data are shown as standard deviation from the mean of sham. Each dot represents a single metabolite in each sample. The vertical lines represent the means of z-scores. n = 6 per group. Blue, red, and green stars denote comparison between CH or HF vs. sham, CHCOV or HFCOV vs. sham, and CH vs. HF, respectively. *, **, and *** denote p < 0.05, p < 0.01, and p < 0.001, respectively.

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  Figure 5. Patterns of protein O-GlcNAcylation in the left ventricles of volume-overloaded rats in the compensated hypertrophic (CH) and heart failure (HF) phases and in volume-overloaded rats with correction of volume overload in the CH (CHCOV) and HF phases (HFCOV) were analyzed by immunoblotting by using a pan-specific CTD 110.6 anti-O-GlcNAc antibody. Arrows indicate bands that show altered O-GlcNAcylation labeling in volume-overloaded rats compared with the corresponding sham controls (A). The levels of protein O-GlcNAcylation were quantified relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by densitometry (B). n = 4 per group. *, **, and *** denote p < 0.05, p < 0.01, and p < 0.001, respectively.

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  Figure 6. Schematic diagrams showing the procedures to create and to close an aortocaval fistula (ACF). The abdominal aorta (AbAo) was punctured with an 18-gauge needle. The needle was inserted into the lateral wall of the aorta and advanced medially through the medial wall and into the inferior vena cava (IVC) (left panel). To close an ACF, the fistula was identified after dissecting the soft tissue between the abdominal aorta and the IVC (dash line) and then clamped with a hemoclip (right panel).