Impaired cardiac glycolysis and glycogen depletion are linked to poor myocardial outcomes in juvenile male swine with metabolic syndrome and ischemia

Figures

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  FIGURE 1. Juvenile swine fed an obesogenic diet developed key physiological components of MetS. The bar graphs display diet‐related differences in glucose (n = 12), low‐density lipoproteins (n = 12), triglycerides (n = 12), systolic blood pressure (n = 12), diastolic blood pressure (n = 12), and weight (n = 12), as shown above the bars. Blue bars represent LD; red bars represent MetS. Data is presented as means ± SD; ***p < 0.001, 2‐tailed Student's t‐test.

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  FIGURE 2. NMF selected overrepresented metabolomic changes in the juvenile MetS heart. The polar metabolites were extracted from left ventricular cardiac tissue (50 mg). LC/MS–MS was applied to identify and semi‐quantitatively measure the content of individual polar metabolites from swine (MetS n = 6, LD n = 6). The bar diagram shows overrepresented pathways in MetS versus. LD. Their p values are shown with the colored bar on right.

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  FIGURE 3. The availability of metabolites related to glycolysis was significantly reduced in the juvenile myocardium in response to MetS. (a) Targeted polar metabolites were identified by LC/MS–MS in extracts from LD and MetS swine myocardial tissues. Myocardial metabolite libraries from LD and MetS pigs were compared for relative content of metabolites that changed in response to MetS. Metabolites from the glycolysis pathway that were significantly altered in response to diet include G6P, F6P, FBP, pyruvate, lactate, and ATP, which are shown above each graph. Metabolite availability was compared in tissue and in blood, as shown below each graph. HPP content did not significantly alter in tissue and was used as a control for the equal loading of metabolites. Blue bars represent LD metabolites; red bars represent MetS metabolites. Values are expressed in relative units (r.u.) and are presented as means ± SD, *p ≤ 0.050, **p < 0.050; 2‐tailed Student's t‐test. (b) MetS versus. LD changes in mRNA and/or protein levels are shown for genes with essential functions in glycolysis identified by RNA‐seq and mass spectroscopy: glucose transporters GLUT1 and, GLUT4; hexokinase 1 (HK1),…

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  FIGURE 4. MetS stimulated glycogen deficiency in the juvenile myocardium. (a) PAS staining for glycogen (lilac) of tissue sections from MetS and LD; α‐amylase treatment followed by PAS (MetS+A, LD + A). The bars on the right present the average expressed in relative units (pixels, after subtraction of the signal following α‐amylase treatment). (b) MetS versus. LD changes in expression at the mRNA and/or protein levels are shown for genes with essential functions in glycogen content identified by RNA‐seq and/or mass spectroscopy: GYS1, PYGL, PYGM, GSK3α, GSK3β, and GDI. The RNA‐seq data is shown in gray for LD (n = 4) and blue for MetS (n = 4); the mass spec protein data is shown in orange for LD and green for MetS. The gene identity and p values are shown on top of the bar diagrams. Values are expressed in relative units (r.u.) on the vertical axes and are presented as means ± SD; *p < 0.05, **p < 0.005 (Student's t‐test). (c) Western blot results showed the amount of GYS1 present in tissue lysates (protein 50 μg/lane) from three representative LD (1, 2, 3) and MetS (4, 5, 6) pigs. Lane M displays the migration of the molecular marker with molecular masses shown on the left. The bar graph…

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  FIGURE 5. Graph showing the impact of MetS on glycolysis and glycogen in the juvenile myocardium. Glycolysis and glycogen‐related enzymes that are altered in MetS are highlighted in gray; orange – metabolic intermediates; black arrow denotes downregulation in MetS; red arrow denotes upregulation in MetS; the glycolysis pathway is shown in green and the glycogen is highlighted in dark green.