Abstract 12117: The Cardioprotection of Trimetazidine Against Ischemic Injury is Mediated by AMPK and ERK Signaling Pathway

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Zhenling Liu ◽  
Yina Ma ◽  
Michelle Kuznicki ◽  
Xingchi Chen ◽  
Wanqing Sun ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Glucose Oxidation ◽  
Ex Vivo ◽  
Ischemic Injury ◽  
Erk Signaling ◽  
Acid Oxidation ◽  
Ampk Signaling ◽  
Heart Perfusion

Introduction: Trimetazidine (TMZ) is an anti-anginal drug that has been widely used in Europe and Asia. The TMZ can optimize energy metabolism via inhibition of long-chain 3-ketoacyl CoA thiolase (3-KAT) in the heart, with subsequent decrease in fatty acid oxidation and stimulation of glucose oxidation. However, the mechanism by which TMZ aids in cardioprotection against ischemic injury has not been characterized. Hypothesis: AMP-activated protein kinase (AMPK) is an energy sensor that control ATP supply from substrate metabolism and protect heart from energy stress. TMZ changes the cardiac AMP/ATP ratio via modulating fatty acid oxidation, thereby it may trigger AMPK signaling cascade that contribute to protection heart from ischemia/reperfusion (I/R) injury. Methods: The mouse in vivo regional ischemia and reperfusion by the ligation of the left anterior descending coronary artery (LAD) were used for determination of myocardial infarction. The infarct size was compared between C57BL/6J WT mice and AMPK kinase dead (KD) transgenic mice with or without TMZ treatment. The ex vivo working heart perfusion system was used to monitor the effect of TMZ on glucose oxidation and fatty acid oxidation in the heart. Results: TMZ treatment significantly stimulates cardiac AMPK and extracellular signal-regulated kinase (ERK) signaling pathways (p<0.05 vs. vehicle group). The administration of TMZ reduces myocardial infarction size in WT C57BL/6J hearts, the reduction of myocardial infarction size by TMZ in AMPK KD hearts was significantly impaired versus WT hearts (p<0.05). Intriguingly, the administration of ERK inhibitor, PD 98059, to AMPK KD mice abolished the cardioprotection of TMZ against I/R injury. The ex vivo working heart perfusion data demonstrated that TMZ treatment significantly activates AMPK signaling and modulating the substrate metabolism by shifting fatty acid oxidation to glucose oxidation during reperfusion, leading to reduction of oxidative stress in the I/R hearts. Conclusions: Both AMPK and ERK signaling pathways mediate the cardioprotection of TMZ against ischemic injury. The metabolic benefits of TMZ for angina patients could be due to the activation of energy sensor AMPK in the heart by TMZ administration.

scholarly journals Acetylation and succinylation contribute to maturational alterations in energy metabolism in the newborn heart

2016 ◽  
Vol 311 (2) ◽  
pp. H347-H363 ◽  
Author(s):  
Arata Fukushima ◽  
Osama Abo Alrob ◽  
Liyan Zhang ◽  
Cory S. Wagg ◽  
Tariq Altamimi ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Energy Metabolism ◽  
Fatty Acid Oxidation ◽  
Glucose Oxidation ◽  
Acid Oxidation ◽  
Amino Acid Synthesis ◽  
Oxidation Rates ◽  
Cardiac Energy Metabolism ◽  
Cardiac Energy ◽  
The Impact

Dramatic maturational changes in cardiac energy metabolism occur in the newborn period, with a shift from glycolysis to fatty acid oxidation. Acetylation and succinylation of lysyl residues are novel posttranslational modifications involved in the control of cardiac energy metabolism. We investigated the impact of changes in protein acetylation/succinylation on the maturational changes in energy metabolism of 1-, 7-, and 21-day-old rabbit hearts. Cardiac fatty acid β-oxidation rates increased in 21-day vs. 1- and 7-day-old hearts, whereas glycolysis and glucose oxidation rates decreased in 21-day-old hearts. The fatty acid oxidation enzymes, long-chain acyl-CoA dehydrogenase (LCAD) and β-hydroxyacyl-CoA dehydrogenase (β-HAD), were hyperacetylated with maturation, positively correlated with their activities and fatty acid β-oxidation rates. This alteration was associated with increased expression of the mitochondrial acetyltransferase, general control of amino acid synthesis 5 like 1 (GCN5L1), since silencing GCN5L1 mRNA in H9c2 cells significantly reduced acetylation and activity of LCAD and β-HAD. An increase in mitochondrial ATP production rates with maturation was associated with the decreased acetylation of peroxisome proliferator-activated receptor-γ coactivator-1α, a transcriptional regulator for mitochondrial biogenesis. In addition, hypoxia-inducible factor-1α, hexokinase, and phosphoglycerate mutase expression declined postbirth, whereas acetylation of these glycolytic enzymes increased. Phosphorylation rather than acetylation of pyruvate dehydrogenase (PDH) increased in 21-day-old hearts, accounting for the low glucose oxidation postbirth. A maturational increase was also observed in succinylation of PDH and LCAD. Collectively, our data are the first suggesting that acetylation and succinylation of the key metabolic enzymes in newborn hearts play a crucial role in cardiac energy metabolism with maturation. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/acetylation-control-of-energy-metabolism-in-newborn-hearts/ .

Isoproterenol stimulates 5′-AMP-activated protein kinase and fatty acid oxidation in neonatal hearts

2010 ◽  
Vol 299 (4) ◽  
pp. H1135-H1145 ◽  
Author(s):  
Jagdip S. Jaswal ◽  
Chad R. Lund ◽  
Wendy Keung ◽  
Donna L. Beker ◽  
Ivan M. Rebeyka ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Protein Kinase ◽  
Fatty Acid Oxidation ◽  
Energy Demand ◽  
Glucose Oxidation ◽  
Acid Oxidation ◽  
Acetyl Coa ◽  
Lactate Oxidation ◽  
Major Energy Source ◽  
Amp Activated Protein Kinase

Isoproterenol increases phosphorylation of LKB, 5′-AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase (ACC), enzymes involved in regulating fatty acid oxidation. However, inotropic stimulation selectively increases glucose oxidation in adult hearts. In the neonatal heart, fatty acid oxidation becomes a major energy source, while glucose oxidation remains low. This study tested the hypothesis that increased energy demand imposed by isoproterenol originates from fatty acid oxidation, secondary to increased LKB, AMPK, and ACC phosphorylation. Isolated working hearts from 7-day-old rabbits were perfused with Krebs solution (0.4 mM palmitate, 11 mM glucose, 0.5 mM lactate, and 100 mU/l insulin) with or without isoproterenol (300 nM). Isoproterenol increased myocardial O2 consumption (in J·g dry wt−1·min−1; 11.0 ± 1.4, n = 8 vs. 7.5 ± 0.8, n = 6, P < 0.05), and the phosphorylation of LKB (in arbitrary density units; 0.87 ± 0.09, n = 6 vs. 0.59 ± 0.08, n = 6, P < 0.05), AMPK (0.82 ± 0.08, n = 6 vs. 0.51 ± 0.06, n = 6, P < 0.05), and ACC-β (1.47 ± 0.14, n = 6 vs. 0.97 ± 0.07, n = 6, P < 0.05), with a concomitant decrease in malonyl-CoA levels (in nmol/g dry wt; 0.9 ± 0.9, n = 8 vs. 7.5 ± 1.3, n = 8, P < 0.05) and increase in palmitate oxidation (in nmol·g dry wt−1·min−1; 272 ± 45, n = 8 vs. 114 ± 9, n = 6, P < 0.05). Glucose and lactate oxidation were increased (in nmol·g dry wt−1·min−1; 253 ± 75, n = 8 vs. 63 ± 15, n = 9, P < 0.05 and 246 ± 43, n = 8 vs. 82 ± 11, n = 6, P < 0.05, respectively), independent of alterations in pyruvate dehydrogenase phosphorylation, but occurred secondary to a decrease in acetyl-CoA content and acetyl-CoA-to-free CoA ratio. As acetyl-CoA levels decrease in response to isoproterenol, despite an acceleration of the rates of palmitate and carbohydrate oxidation, these data suggest net rates of acetyl-CoA utilization exceed the net rates of acetyl-CoA generation.

Abstract 344: FNDC5, a PGC1-a-Dependent Myokine, Increases Glucose Utilization and Fatty-Acid Oxidation by AMPK Signaling Pathway

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Ling Tao ◽  
Yi Liu ◽  
Chao Xin ◽  
Weidong Huang ◽  
Lijian Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Glucose Uptake ◽  
Fatty Acid Oxidation ◽  
Glucose Utilization ◽  
C2c12 Cells ◽  
Time Dependent ◽  
Acid Oxidation ◽  
Ampk Signaling

FNDC5 is a hormone secreted by myocytes that could reduce obesity and insulin resistance, However, the exact effect of FNDC5 on glucose and lipid metabolism remain poorly identified; More importantly, the signaling pathways that mediate the metabolic effects of FNDC5 is completely unknown. Here we showed that FNDC5 stimulates β-oxidation and glucose uptake in C2C12 cells in a dose- and time-dependent fashion in vitro (n=8, all P<0.01). In vivo study revealed that FNDC5 also enhanced glucose tolerance in diabetic mice and increased the glucose uptake evidenced by increased [18F] FDG accumulation in hearts by PET scan (n=6, all P<0.05). FNDC5 decreased the expression of gluconeogenesis related molecules (PEPCK and G6Pase) and increased the phosphorylation of ACC, a key modulator of fatty-acid oxidation, both in hepatocytes and C2C12 cells (n=3, all P<0.05). In parallel with its stimulation of β-oxidation and glucose uptake, FNDC5 increased the phosphorylation of AMPK both in hepatocytes and C2C12 cells in a dose- and time-dependent fashion in vitro and in vivo. More importantly, the β-oxidation and glucose uptake, the expression of PEPCK and G6Pase and the phosphorylation of ACC induced by FNDC5 were attenuated by AMPK inhibitor in hepatocytes and C2C12 cells (P<0.05). Most importantly, the FNDC5 induced glucose uptake and phosphorylation of ACC were attenuated in AMPK-DN mice (n=6, all P<0.05). The glucose-lowering effect of FNDC5 in diabetic mice was also attenuated by AMPK inhibitor. Our data presents the direct evidence that FNDC5 stimulates glucose utilization and fatty-acid oxidation by AMPK signaling pathway, suggesting that FNDC5 be a novel pharmacological approach for type 2 diabetes.

Abstract 653: Muscle Ring Finger-1 (MuRF1) Expression Shifts Cardiomyocyte Substrate Utilization from Fatty Acids to Glucose

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Monte S Willis ◽  
Jon Schisler ◽  
Holly McDonough ◽  
Cam Patterson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Glucose Oxidation ◽  
Relative Proportion ◽  
Substrate Utilization ◽  
Acid Oxidation ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Dose Dependent

Previous work has suggested that MuRF1, a cardiac-specific protein, regulates metabolism by its interactions with proteins that regulate ATP transport, glycolysis, and the electron transport chain. We recently identified that MuRF1 is cardioprotective in ischemia reperfusion injury. In the current study, we investigated the effects of MuRF1 expression on metabolic substrate utilization and found that MuRF1 shifts substrate utilization from fatty acids to glucose in a dose-dependent manner. Isolated neonatal ventricular cardiomyocytes were treated with an adenovirus expressing MuRF1 (Ad.MuRF1) or GFP (Ad.GFP) at a range of 0–25 MOI (Multiplicity Of Infection). 14C-Oleate or 14C-glucose were added to cells for 1 hour and 14C-CO2 release was determined using the CO2-trapping method. Trapped 14CO2 and acid soluble metabolites were used to calculate total fatty acid oxidation. Cardiomyocytes treated with 5–25 MOI Ad.MuRF1 demonstrated a dose dependent decrease in fatty acid oxidation of 10.5 +/− 2.3(5 MOI), 8.5 +/− 1.9 (10 MOI), 6.6 +/− 1.6 (15 MOI), and 5.1 +/− 1.3 (25 MOI) nmol oleate/mg protein/h. Compared with control cardiomyocytes treated with 5–25 MOI Ad.GFP (average of 5–25 MOI=13.5 +/− 0.7 nmol oleate/mg protein/h), this represents a 22.2%– 62.2% decrease in fatty acid oxidation. Inversely, glucose oxidation increased with increasing MuRF1 expression. Cardiomyocytes infected with 25 MOI Ad.MuRF1 oxidized 184% more glucose (28.9 +/− 4.6 nmol glucose/mg protein/h) compared to control cells treated with 25 MOI Ad.GFP (15.7 +/− 1.3 nmol glucose/mg protein/h). Increasing MuRF1 expression resulted in no net gain or loss of calculated ATP production (1699 +/− 157 vs. 1480 +/− 188 nmol ATP/mg protein/h). The co-utilization of glucose and fatty acids as substrates for the production of ATP allows the heart to adapt to both environmental stress and disease. Increasing the relative proportion of glucose oxidation in relationship to fatty acids is a known protective mechanism during cardiac stress, and may represent one mechanism by which MuRF1 is cardioprotective.

scholarly journals Western diet, but not high fat diet, causes derangements of fatty acid metabolism and contractile dysfunction in the heart of Wistar rats

2007 ◽  
Vol 406 (3) ◽  
pp. 457-467 ◽  
Author(s):  
Christopher R. Wilson ◽  
Mai K. Tran ◽  
Katrina L. Salazar ◽  
Martin E. Young ◽  
Heinrich Taegtmeyer
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Ex Vivo ◽  
Western Diet ◽  
Acid Oxidation ◽  
Contractile Dysfunction ◽  
High Fat ◽  
Cardiac Contractile ◽  
Cardiac Contractile Dysfunction

Obesity and diabetes are associated with increased fatty acid availability in excess of muscle fatty acid oxidation capacity. This mismatch is implicated in the pathogenesis of cardiac contractile dysfunction and also in the development of skeletal-muscle insulin resistance. We tested the hypothesis that ‘Western’ and high fat diets differentially cause maladaptation of cardiac- and skeletal-muscle fatty acid oxidation, resulting in cardiac contractile dysfunction. Wistar rats were fed on low fat, ‘Western’ or high fat (10, 45 or 60% calories from fat respectively) diet for acute (1 day to 1 week), short (4–8 weeks), intermediate (16–24 weeks) or long (32–48 weeks) term. Oleate oxidation in heart muscle ex vivo increased with high fat diet at all time points investigated. In contrast, cardiac oleate oxidation increased with Western diet in the acute, short and intermediate term, but not in the long term. Consistent with fatty acid oxidation maladaptation, cardiac power decreased with long-term Western diet only. In contrast, soleus muscle oleate oxidation (ex vivo) increased only in the acute and short term with either Western or high fat feeding. Fatty acid-responsive genes, including PDHK4 (pyruvate dehydrogenase kinase 4) and CTE1 (cytosolic thioesterase 1), increased in heart and soleus muscle to a greater extent with feeding a high fat diet compared with a Western diet. In conclusion, we implicate inadequate induction of a cassette of fatty acid-responsive genes, and impaired activation of fatty acid oxidation, in the development of cardiac dysfunction with Western diet.

Epinephrine increases ATP production in hearts by preferentially increasing glucose metabolism

1994 ◽  
Vol 267 (5) ◽  
pp. H1862-H1871 ◽  
Author(s):  
R. L. Collins-Nakai ◽  
D. Noseworthy ◽  
G. D. Lopaschuk
Keyword(s):  
Fatty Acid ◽  
Glucose Metabolism ◽  
Fatty Acid Oxidation ◽  
Glucose Oxidation ◽  
Contractile Function ◽  
Pyruvate Dehydrogenase Complex ◽  
Active Form ◽  
Acid Oxidation ◽  
Complex Activity ◽  
Atp Production

Although epinephrine is widely used clinically, its effect on myocardial energy substrate preference in the intact heart has yet to be clearly defined. We determined the effects of epinephrine on glucose and fatty acid metabolism in isolated working rat hearts perfused with 11 mM glucose, 0.4 mM palmitate, and 100 muU/ml insulin at an 11.5-mmHg left atrial preload and a 60-mmHg aortic afterload. Glycolysis and glucose oxidation were measured in hearts perfused with [5–3H]glucose and [U-14C]glucose, whereas fatty acid oxidation was measured in hearts perfused with [1–14C]palmitate. Addition of 1 microM epinephrine resulted in a 53% increase in the heart rate-developed pressure product. Glycolysis increased dramatically following addition of epinephrine (a 272% increase), as did glucose oxidation (a 410% increase). In contrast, fatty acid oxidation increased by only 10%. Epinephrine treatment did not increase the amount of oxygen required to produce an equivalent amount of ATP; however, epinephrine did increase the uncoupling between glycolysis and glucose oxidation in these fatty acid-perfused hearts, resulting in a significant increase in H+ production from glucose metabolism. Overall ATP production in epinephrine-treated hearts increased 59%. The contribution of glucose (glycolysis and glucose oxidation) to ATP production increased from 13 to 36%, which was accompanied by a reciprocal decrease in the contribution of fatty acid oxidation to ATP production from 83 to 63%. The increase in glucose oxidation was accompanied by a significant increase in pyruvate dehydrogenase complex activity in the active form. We conclude that the increase in ATP required for contractile function following epinephrine treatment occurs through a preferential increase in glucose use.

scholarly journals METABOLIC FLEXIBILITY IN CLASSICAL MONOCYTES IS NOT AFFECTED BY AGE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S105-S105
Author(s):  
Johnathan Yarbro ◽  
Brandt Pence
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Immune Cell ◽  
Ex Vivo ◽  
Inflammatory Cells ◽  
Acid Oxidation ◽  
Low Grade ◽  
Glucose Starvation ◽  
Cell Functions ◽  
Age Related

Abstract Inflammaging is the chronic low-grade inflammation that occurs with age that contributes to the pathology of age-related diseases. Monocytes are innate immune cells that become dysregulated with age and which can contribute to inflammaging. Metabolism plays a key role in determining immune cell functions, with anti-inflammatory cells primarily relying on fatty acid oxidation and pro-inflammatory cells primarily relying on glycolysis. It was recently shown that lipopolysaccharide (LPS)-stimulated monocytes can compensate for a lack of glucose by utilizing fatty acid oxidation. Given that mitochondrial function decreases with age, we hypothesized that monocytes taken from aged individuals would have an impaired ability to upregulate oxidative metabolism and would have impaired effector functions. Aging did not impair LPS-induced oxygen consumption rate during glucose starvation as measured on a Seahorse XFp system. Additionally, aged monocytes maintained inflammatory gene expression responses and phagocytic capacity during LPS stimulation in the absence of glucose. In conclusion, aged monocytes maintain effector and metabolic functions during glucose starvation, at least in an ex vivo context.

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