1
|
Application of response surface methodology (RSM) for optimization of the supercritical CO2 extract of oil from Zanthoxylum bungeanum pericarp: Yield, composition and gastric protective effect. Food Chem X 2022; 15:100391. [PMID: 36211759 PMCID: PMC9532734 DOI: 10.1016/j.fochx.2022.100391] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 11/24/2022] Open
Abstract
Supercritical carbon-dioxide (SC-CO2) extract is an effective technology for flavor components of Z. bungeanum pericarp. About 11.07 % oil yield can be obtained under the optimized parameters of 30 MPa, 43 °C, and 75 min. Limonene, linalool, hydroxy-α-sanshool and hydroxy-β-sanshool are the major flavor components of SZB. SZB supplementation could be employed as a gastric protective agent/additive for human health. Nineteen potential biomarkers were identified as the potential biomarkers contributed to the gastric protective effect of SZB.
Supercritical carbon-dioxide (SC-CO2) is a promising two-phase technology for flavor components (volatile oil and alkylamides) extract from Zanthoxylum bungeanum pericarp. However, the gastric protective effect of SC-CO2 extract from Z. bungeanum (SZB) have not been systematically investigated. In this study, response surface methodology (RSM) was employed to optimize the yield of SZB, and the average yield of 11.07 % were obtained under optimal parameters (30 MPa, 43 °C and time 75 min). Here, limonene, linalool and hydroxy-α-sanshool were identified as the main compounds of SZB by GC–MS and UPLC-Q-Extractive Orbitrap/MS analysis. When the gastric protective effect of SZB (5, 10 and 20 mg/kg, p.o.) were evaluated, significant increase in body weight and organ indexes of rat, and decreased gastric lesion were observed. Furthermore, nineteen serum metabolites were regarded as the potential biomarkers for the gastric protective effect of SZB. Collectively, this study provides a comprehensive perspective into the chemical composition analysis and gastric protective effect of Z. bungeanum SC-CO2 extract.
Collapse
|
2
|
Slaats RH, Schwach V, Passier R. Metabolic environment in vivo as a blueprint for differentiation and maturation of human stem cell-derived cardiomyocytes. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165881. [PMID: 32562698 DOI: 10.1016/j.bbadis.2020.165881] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/10/2020] [Accepted: 06/14/2020] [Indexed: 12/26/2022]
Abstract
Patient-derived human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are increasingly being used for disease modeling, drug screening and regenerative medicine. However, to date, an immature, fetal-like, phenotype of hPSC-CMs restrains their full potential. Increasing evidence suggests that the metabolic state, particularly important for provision of sufficient energy in highly active contractile CMs and anabolic and regulatory processes, plays an important role in CM maturation, which affects crucial functional aspects of CMs, such as contractility and electrophysiology. During embryonic development the heart is subjected to metabolite concentrations that differ substantially from that of hPSC-derived cardiac cell cultures. A deeper understanding of the environmental and metabolic cues during embryonic heart development and how these change postnatally, will provide a framework for optimizing cell culture conditions and maturation of hPSC-CMs. Maturation of hPSC-CMs will improve the predictability of disease modeling, drug screening and drug safety assessment and broadens their applicability for personalized and regenerative medicine.
Collapse
Affiliation(s)
- Rolf H Slaats
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, Drienerlolaan 5, 7500AE Enschede, the Netherlands
| | - Verena Schwach
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, Drienerlolaan 5, 7500AE Enschede, the Netherlands
| | - Robert Passier
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, Drienerlolaan 5, 7500AE Enschede, the Netherlands; Department of Anatomy and Embryology, Leiden University Medical Centre, PO Box 9600, 2300 RC Leiden, the Netherlands.
| |
Collapse
|
3
|
Fernandes MSDS, Silva LDLDSE, Kubrusly MS, Lima TRLDA, Muller CR, Américo ALV, Fernandes MP, Cogliati B, Stefano JT, Lagranha CJ, Evangelista FS, Oliveira CP. Aerobic Exercise Training Exerts Beneficial Effects Upon Oxidative Metabolism and Non-Enzymatic Antioxidant Defense in the Liver of Leptin Deficiency Mice. Front Endocrinol (Lausanne) 2020; 11:588502. [PMID: 33329394 PMCID: PMC7732625 DOI: 10.3389/fendo.2020.588502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/22/2020] [Indexed: 12/11/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is one of the most common forms of liver disease, which is associated with several etiological factors, including stress and dysfunction in oxidative metabolism. However, studies showed that aerobic exercise training (AET) can combat the oxidative stress (OS) and improves mitochondrial functionality in the NAFLD. To test the hypothesis that AET improves oxidative metabolism and antioxidant defense in the liver of ob/ob mice. Male ob/ob mice with eight weeks old were separated into two groups: the sedentary group (S), n=7, and the trained group (T), n=7. The T mice were submitted to an 8-week protocol of AET at 60% of the maximum velocity achieved in the running capacity test. Before AET, no difference was observed in running test between the groups (S=10.4 ± 0.7 min vs. T= 13 ± 0.47 min). However, after AET, the running capacity was increased in the T group (12.8 ± 0.87 min) compared to the S group (7.2 ± 0.63 min). In skeletal muscle, the T group (26.91 ± 1.12 U/mg of protein) showed higher citrate synthase activity compared with the S group (19.28 ± 0.88 U/mg of protein) (p =0.006). In the analysis of BW evolution, significant reductions were seen in the T group as of the fourth week when compared to the S group. In addition, food intake was not significant different between the groups. Significant increases were observed in the activity of enzymes citrate synthase (p=0.004) and β-HAD (p=0.01) as well as in PGC-1α gene expression (p=0.002) in the liver of T group. The levels of TBARs and carbonyls, as well as SOD, CAT and GST were not different between the groups. However, in the nonenzymatic antioxidant system, we found that the T group had higher sulfhydryl (p = 0.02), GSH (p=0.001) and GSH/GSSG (p=0.02) activity. In conclusion, the AET improved body weight evolution and the aerobic capacity, increased the response of oxidative metabolism markers in the liver such as PGC-1α gene expression and citrate synthase and β-HAD enzyme activities in ob/ob mice. In addition, AET improved the non-enzymatic antioxidant defense and did not change the enzymatic defense.
Collapse
Affiliation(s)
- Matheus Santos de Sousa Fernandes
- Laboratório de Gastroenterologia Clínica e Experimental LIM-07, Division of Clinical Gastroenterology and Hepatology, Hospital das Clínicas HCFMUSP, Department of Gastroenterology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Lucas de Lucena de Simões e Silva
- Laboratório de Gastroenterologia Clínica e Experimental LIM-07, Division of Clinical Gastroenterology and Hepatology, Hospital das Clínicas HCFMUSP, Department of Gastroenterology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Márcia Saldanha Kubrusly
- Laboratório de Transplante e Cirurgia do Fígado (LIM-37), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | | - Cynthia Rodrigues Muller
- Department of Experimental Pathophysiology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Anna Laura Viacava Américo
- Department of Experimental Pathophysiology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - José Tadeu Stefano
- Laboratório de Gastroenterologia Clínica e Experimental LIM-07, Division of Clinical Gastroenterology and Hepatology, Hospital das Clínicas HCFMUSP, Department of Gastroenterology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Claudia P. Oliveira
- Laboratório de Gastroenterologia Clínica e Experimental LIM-07, Division of Clinical Gastroenterology and Hepatology, Hospital das Clínicas HCFMUSP, Department of Gastroenterology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
- *Correspondence: Claudia P. Oliveira,
| |
Collapse
|
4
|
Carthagenes DS, Barreto MDP, Freitas CM, Pedroza ADS, Fernandes MP, Ferreira DS, Lagranha CJ, Nascimento LC, Evencio LB. Moderate physical training counterbalances harmful effects of low-protein diet on heart: metabolic, oxidative and morphological parameters. MOTRIZ: REVISTA DE EDUCACAO FISICA 2017. [DOI: 10.1590/s1980-6574201700030019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
5
|
Postconditioning with Intralipid emulsion protects against reperfusion injury in post-infarct remodeled rat hearts by activation of ROS-Akt/Erk signaling. Transl Res 2017. [PMID: 28641075 DOI: 10.1016/j.trsl.2017.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The clinically used lipid emulsion Intralipid (ILE) reduces ischemia reperfusion injury in healthy rodent hearts. We tested whether ILE is cardioprotective in postinfarct remodeled hearts. Post-infarct remodeled and sham Sprague-Dawley rat hearts were perfused in working mode and subjected to ischemia (15 minutes) and reperfusion (30 minutes). Left ventricular (LV) work was measured in hearts that were untreated or that received ILE (1%) postconditioning administered at the onset of reperfusion, or the reactive oxygen species (ROS) scavenger N-(2-mercaptopropionyl)-glycine (10 μM) alone or in combination with ILE. Mitochondrial O2 consumption was measured in LV muscle fibers. Acetyl CoA production was calculated from the oxidation of [U-14C]glucose and [9,10-3H]palmitate. ROS production was assessed by loss of aconitase activity as well as by release of hydrogen peroxide. Phosphorylation of Akt, Erk1/2, and STAT3 were used to evaluate protection signaling. Remodeled hearts exhibited LV dysfunction and signs of hypertrophy consistent with significant postinfarct remodeling. ILE postconditioning enhanced the recovery of postischemic LV function in remodeled hearts, preserved energy metabolism in mitochondria, accelerated palmitate oxidation and acetyl CoA production, and activated Akt/Erk/STAT3 in a ROS-dependent manner. Protection by ILE postconditioning evolved rapidly within the first minutes of reperfusion without evidence of additional cardiotonic effects due to provision of supplementary energy substrates potentially released from ILE during reperfusion. ILE represents a novel and clinically feasible cardioprotective strategy that is highly effective in remodeled hearts. Our data provide a rationale for the clinical evaluation of ILE postconditioning where ILE is administered as a bolus at the onset of reperfusion.
Collapse
|
6
|
Fukushima A, Alrob OA, Zhang L, Wagg CS, Altamimi T, Rawat S, Rebeyka IM, Kantor PF, Lopaschuk GD. Acetylation and succinylation contribute to maturational alterations in energy metabolism in the newborn heart. Am J Physiol Heart Circ Physiol 2016; 311:H347-63. [PMID: 27261364 DOI: 10.1152/ajpheart.00900.2015] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/25/2016] [Indexed: 11/22/2022]
Abstract
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.
Collapse
Affiliation(s)
- Arata Fukushima
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Osama Abo Alrob
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and Faculty of Pharmacy, Yarmouk University, Irbid, Jordan
| | - Liyan Zhang
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Cory S Wagg
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Tariq Altamimi
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Sonia Rawat
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Ivan M Rebeyka
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Paul F Kantor
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| | - Gary D Lopaschuk
- Cardiovascular Translational Science Institute, University of Alberta, Edmonton, Alberta, Canada; and
| |
Collapse
|
7
|
Rutaecarpine and evodiamine selected as β1-AR inhibitor candidates using β1-AR/CMC-offline-UPLC/MS prevent cardiac ischemia–reperfusion injury via energy modulation. J Pharm Biomed Anal 2015; 115:307-14. [DOI: 10.1016/j.jpba.2015.07.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 07/14/2015] [Accepted: 07/21/2015] [Indexed: 11/20/2022]
|
8
|
Cao S, Liu Y, Sun W, Zhao L, Zhang L, Liu X, Yu T. Genome-Wide Expression Profiling of Anoxia/Reoxygenation in Rat Cardiomyocytes Uncovers the Role of MitoKATP in Energy Homeostasis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:756576. [PMID: 26171116 PMCID: PMC4485557 DOI: 10.1155/2015/756576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/08/2014] [Indexed: 12/30/2022]
Abstract
Mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) is a common end effector of many protective stimuli in myocardial ischemia-reperfusion injury (MIRI). However, the specific molecular mechanism underlying its myocardial protective effect is not well elucidated. We characterized an anoxia/reoxygenation (A/R) model using freshly isolated adult rat cardiomyocytes. MitoK(ATP) status was interfered with its specific opener diazoxide (DZ) or blocker 5-hydroxydecanote (5-HD). Digital gene expression (DGE) and bioinformatic analysis were deployed. Three energy metabolism related genes (MT-ND6, Idh2, and Acadl) were upregulated when mitoK(ATP) opened. In addition, as many as 20 differentially expressed genes (DEGs) were significantly enriched in five energy homeostasis correlated pathways (PPAR, TCA cycle, fatty acid metabolism, and peroxisome). These findings indicated that mitoK(ATP) opening in MIRI resulted in energy mobilization, which was confirmed by measuring ATP content in cardiomyocytes. These causal outcomes could be a molecular mechanism of myocardial protection of mitoKATP and suggested that the mitoK(ATP) opening plays a physiologic role in triggering cardiomyocytes' energy homeostasis during MIRI. Strategies of modulating energy expenditure during myocardial ischemia-reperfusion may be promising approaches to reduce MIRI.
Collapse
Affiliation(s)
- Song Cao
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
| | - Yun Liu
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
- Research Center for Medicine & Biology, Zunyi Medical College, Zunyi 563000, China
| | - Wenting Sun
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
| | - Li Zhao
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
| | - Lin Zhang
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
| | - Xinkui Liu
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
| | - Tian Yu
- Department of Anesthesiology, Zunyi Medical College, Zunyi 563000, China
- Guizhou Key Laboratory of Anesthesiology and Organ Protection, Zunyi Medical College, Zunyi 563000, China
| |
Collapse
|
9
|
Lam VH, Zhang L, Huqi A, Fukushima A, Tanner BA, Onay-Besikci A, Keung W, Kantor PF, Jaswal JS, Rebeyka IM, Lopaschuk GD. Activating PPARα prevents post-ischemic contractile dysfunction in hypertrophied neonatal hearts. Circ Res 2015; 117:41-51. [PMID: 25977309 DOI: 10.1161/circresaha.117.306585] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 05/14/2015] [Indexed: 11/16/2022]
Abstract
RATIONALE Post-ischemic contractile dysfunction is a contributor to morbidity and mortality after the surgical correction of congenital heart defects in neonatal patients. Pre-existing hypertrophy in the newborn heart can exacerbate these ischemic injuries, which may partly be due to a decreased energy supply to the heart resulting from low fatty acid β-oxidation rates. OBJECTIVE We determined whether stimulating fatty acid β-oxidation with GW7647, a peroxisome proliferator-activated receptor-α (PPARα) activator, would improve cardiac energy production and post-ischemic functional recovery in neonatal rabbit hearts subjected to volume overload-induced cardiac hypertrophy. METHODS AND RESULTS Volume-overload cardiac hypertrophy was produced in 7-day-old rabbits via an aorto-caval shunt, after which, the rabbits were treated with or without GW7647 (3 mg/kg per day) for 14 days. Biventricular working hearts were subjected to 35 minutes of aerobic perfusion, 25 minutes of global no-flow ischemia, and 30 minutes of aerobic reperfusion. GW7647 treatment did not prevent the development of cardiac hypertrophy, but did prevent the decline in left ventricular ejection fraction in vivo. GW7647 treatment increased cardiac fatty acid β-oxidation rates before and after ischemia, which resulted in a significant increase in overall ATP production and an improved in vitro post-ischemic functional recovery. A decrease in post-ischemic proton production and endoplasmic reticulum stress, as well as an activation of sarcoplasmic reticulum calcium ATPase isoform 2 and citrate synthase, was evident in GW7647-treated hearts. CONCLUSIONS Stimulating fatty acid β-oxidation in neonatal hearts may present a novel cardioprotective intervention to limit post-ischemic contractile dysfunction.
Collapse
Affiliation(s)
- Victoria H Lam
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Liyan Zhang
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Alda Huqi
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Arata Fukushima
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Brandon A Tanner
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Arzu Onay-Besikci
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Wendy Keung
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Paul F Kantor
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Jagdip S Jaswal
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Ivan M Rebeyka
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.)
| | - Gary D Lopaschuk
- From the Cardiovascular Translational Science Institute (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.) and Department of Pediatrics (V.H.L., L.Z., A.H., A.F., B.A.T., W.K., P.F.K., J.S.J., I.M.R., G.D.L.), University of Alberta, Edmonton, Canada; and Department of Medical Pharmacology, Ankara University, Ankara, Turkey (A.O.-B.).
| |
Collapse
|
10
|
Lou PH, Lucchinetti E, Zhang L, Affolter A, Schaub MC, Gandhi M, Hersberger M, Warren BE, Lemieux H, Sobhi HF, Clanachan AS, Zaugg M. The mechanism of Intralipid®-mediated cardioprotection complex IV inhibition by the active metabolite, palmitoylcarnitine, generates reactive oxygen species and activates reperfusion injury salvage kinases. PLoS One 2014; 9:e87205. [PMID: 24498043 PMCID: PMC3907505 DOI: 10.1371/journal.pone.0087205] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/23/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Intralipid® administration at reperfusion elicits protection against myocardial ischemia-reperfusion injury. However, the underlying mechanisms are not fully understood. METHODS Sprague-Dawley rat hearts were exposed to 15 min of ischemia and 30 min of reperfusion in the absence or presence of Intralipid® 1% administered at the onset of reperfusion. In separate experiments, the reactive oxygen species (ROS) scavenger N-(2-mercaptopropionyl)-glycine was added either alone or with Intralipid®. Left ventricular work and activation of Akt, STAT3, and ERK1/2 were used to evaluate cardioprotection. ROS production was assessed by measuring the loss of aconitase activity and the release of hydrogen peroxide using Amplex Red. Electron transport chain complex activities and proton leak were measured by high-resolution respirometry in permeabilized cardiac fibers. Titration experiments using the fatty acid intermediates of Intralipid® palmitoyl-, oleoyl- and linoleoylcarnitine served to determine concentration-dependent inhibition of complex IV activity and mitochondrial ROS release. RESULTS Intralipid® enhanced postischemic recovery and activated Akt and Erk1/2, effects that were abolished by the ROS scavenger N-(2-mercaptopropionyl)glycine. Palmitoylcarnitine and linoleoylcarnitine, but not oleoylcarnitine concentration-dependently inhibited complex IV. Only palmitoylcarnitine reached high tissue concentrations during early reperfusion and generated significant ROS by complex IV inhibition. Palmitoylcarnitine (1 µM), administered at reperfusion, also fully mimicked Intralipid®-mediated protection in an N-(2-mercaptopropionyl)-glycine -dependent manner. CONCLUSIONS Our data describe a new mechanism of postconditioning cardioprotection by the clinically available fat emulsion, Intralipid®. Protection is elicited by the fatty acid intermediate palmitoylcarnitine, and involves inhibition of complex IV, an increase in ROS production and activation of the RISK pathway.
Collapse
Affiliation(s)
- Phing-How Lou
- Postdoctoral Fellow, Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
| | - Eliana Lucchinetti
- Research Associate, Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Liyan Zhang
- Research Associate, Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Andreas Affolter
- Research Associate, Department of Clinical Chemistry, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Marcus C. Schaub
- Professor, Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Manoj Gandhi
- Research Associate, Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Martin Hersberger
- Head of the Department of Clinical Chemistry, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Blair E. Warren
- Undergraduate student, Campus Saint-Jean, University of Alberta, Edmonton, AB, Canada
| | - Hélène Lemieux
- Assistant Professor, Campus Saint-Jean, University of Alberta, Edmonton, AB, Canada
| | - Hany F. Sobhi
- Assistant Professor and Director of Coppin Center for Organic Synthesis, Coppin State University, Baltimore, Maryland, United States of America
| | | | - Michael Zaugg
- Professor, Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, AB, Canada
- * E-mail:
| |
Collapse
|
11
|
Shrivastav S, Zhang L, Okamoto K, Lee H, Lagranha C, Abe Y, Balasubramanyam A, Lopaschuk GD, Kino T, Kopp JB. HIV-1 Vpr enhances PPARβ/δ-mediated transcription, increases PDK4 expression, and reduces PDC activity. Mol Endocrinol 2013; 27:1564-76. [PMID: 23842279 DOI: 10.1210/me.2012-1370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
HIV infection and its therapy are associated with disorders of lipid metabolism and bioenergetics. Previous work has suggested that viral protein R (Vpr) may contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients. In adipocytes, Vpr suppresses mRNA expression of peroxisomal proliferator-activating receptor-γ (PPARγ)-responsive genes and inhibits differentiation. We investigated whether Vpr might interact with PPARβ/δ and influence its transcriptional activity. In the presence of PPARβ/δ, Vpr induced a 3.3-fold increase in PPAR response element-driven transcriptional activity, a 1.9-fold increase in pyruvate dehydrogenase kinase 4 (PDK4) protein expression, and a 1.6-fold increase in the phosphorylated pyruvate dehydrogenase subunit E1α leading to a 47% decrease in the activity of the pyruvate dehydrogenase complex in HepG2 cells. PPARβ/δ knockdown attenuated Vpr-induced enhancement of endogenous PPARβ/δ-responsive PDK4 mRNA expression. Vpr induced a 1.3-fold increase in mRNA expression of both carnitine palmitoyltransferase I (CPT1) and acetyl-coenzyme A acyltransferase 2 (ACAA2) and doubled the activity of β-hydroxylacyl coenzyme A dehydrogenase (HADH). Vpr physically interacted with the ligand-binding domain of PPARβ/δ in vitro and in vivo. Consistent with a role in energy expenditure, Vpr increased state-3 respiration in isolated mitochondria (1.16-fold) and basal oxygen consumption rate in intact HepG2 cells (1.2-fold) in an etomoxir-sensitive manner, indicating that the oxygen consumption rate increase is β-oxidation-dependent. The effects of Vpr on PPAR response element activation, pyruvate dehydrogenase complex activity, and β-oxidation were reversed by specific PPARβ/δ antagonists. These results support the hypothesis that Vpr contributes to impaired energy metabolism and increased energy expenditure in HIV patients.
Collapse
Affiliation(s)
- Shashi Shrivastav
- Kidney Disease Section, National Institute of Diabetes and Digestive andKidney Diseases, National Institutes of Health,Bethesda, Maryland 20892-1268, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Kajimoto M, O'Kelly Priddy CM, Ledee DR, Xu C, Isern N, Olson AK, Portman MA. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo. J Mol Cell Cardiol 2013; 62:144-52. [PMID: 23727393 DOI: 10.1016/j.yjmcc.2013.05.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 05/18/2013] [Accepted: 05/21/2013] [Indexed: 12/29/2022]
Abstract
Extracorporeal membrane oxygenation (ECMO) supports infants and children with severe cardiopulmonary compromise. Nutritional support for these children includes provision of medium- and long-chain fatty acids (FAs). However, ECMO induces a stress response, which could limit the capacity for FA oxidation. Metabolic impairment could induce new or exacerbate existing myocardial dysfunction. Using a clinically relevant piglet model, we tested the hypothesis that ECMO maintains the myocardial capacity for FA oxidation and preserves myocardial energy state. Provision of 13-Carbon labeled medium-chain FA (octanoate), long-chain free FAs (LCFAs), and lactate into systemic circulation showed that ECMO promoted relative increases in myocardial LCFA oxidation while inhibiting lactate oxidation. Loading of these labeled substrates at high dose into the left coronary artery demonstrated metabolic flexibility as the heart preferentially oxidized octanoate. ECMO preserved this octanoate metabolic response, but also promoted LCFA oxidation and inhibited lactate utilization. Rapid upregulation of pyruvate dehydrogenase kinase-4 (PDK4) protein appeared to participate in this metabolic shift during ECMO. ECMO also increased relative flux from lactate to alanine further supporting the role for pyruvate dehydrogenase inhibition by PDK4. High dose substrate loading during ECMO also elevated the myocardial energy state indexed by phosphocreatine to ATP ratio. ECMO promotes LCFA oxidation in immature hearts, while maintaining myocardial energy state. These data support the appropriateness of FA provision during ECMO support for the immature heart.
Collapse
Affiliation(s)
- Masaki Kajimoto
- Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, WA, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Pulinilkunnil T, Kienesberger PC, Nagendran J, Waller TJ, Young ME, Kershaw EE, Korbutt G, Haemmerle G, Zechner R, Dyck JR. Myocardial adipose triglyceride lipase overexpression protects diabetic mice from the development of lipotoxic cardiomyopathy. Diabetes 2013; 62:1464-77. [PMID: 23349479 PMCID: PMC3636613 DOI: 10.2337/db12-0927] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although diabetic cardiomyopathy is associated with enhanced intramyocardial triacylglycerol (TAG) levels, the role of TAG catabolizing enzymes in this process is unclear. Because the TAG hydrolase, adipose triglyceride lipase (ATGL), regulates baseline cardiac metabolism and function, we examined whether alterations in cardiomyocyte ATGL impact cardiac function during uncontrolled type 1 diabetes. In genetic (Akita) and pharmacological (streptozotocin) murine models of type 1 diabetes, cardiac ATGL protein expression and TAG content were significantly increased. To determine whether increased ATGL expression during diabetes is detrimental or beneficial to cardiac function, we studied streptozotocin-diabetic mice with heterozygous ATGL deficiency and cardiomyocyte-specific ATGL overexpression. After diabetes, streptozotocin-diabetic mice with heterozygous ATGL deficiency displayed increased TAG accumulation, lipotoxicity, and diastolic dysfunction comparable to wild-type mice. In contrast, myosin heavy chain promoter (MHC)-ATGL mice were resistant to diabetes-induced increases in intramyocardial TAG levels, lipotoxicity, and cardiac dysfunction. Moreover, hearts from diabetic MHC-ATGL mice exhibited decreased reliance on palmitate oxidation and blunted peroxisome proliferator--activated receptor-α activation. Collectively, this study shows that after diabetes, increased cardiac ATGL expression is an adaptive, albeit insufficient, response to compensate for the accumulation of myocardial TAG, and that overexpression of ATGL is sufficient to ameliorate diabetes-induced cardiomyopathy.
Collapse
Affiliation(s)
- Thomas Pulinilkunnil
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Petra C. Kienesberger
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jeevan Nagendran
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Terri J. Waller
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Martin E. Young
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Erin E. Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Gregory Korbutt
- Alberta Diabetes Institute and Cardiovascular Research Centre, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jason R.B. Dyck
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Corresponding author: Jason R.B. Dyck,
| |
Collapse
|
14
|
Tanno M, Kuno A. Reversal of metabolic shift in post-infarct-remodelled hearts: possible novel therapeutic approach. Cardiovasc Res 2012; 97:195-6. [PMID: 23234681 DOI: 10.1093/cvr/cvs364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
15
|
Lou PH, Zhang L, Lucchinetti E, Heck M, Affolter A, Gandhi M, Kienesberger PC, Hersberger M, Clanachan AS, Zaugg M. Infarct-remodelled hearts with limited oxidative capacity boost fatty acid oxidation after conditioning against ischaemia/reperfusion injury. Cardiovasc Res 2012; 97:251-61. [PMID: 23097573 DOI: 10.1093/cvr/cvs323] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
AIMS Infarct-remodelled hearts are less amenable to protection against ischaemia/reperfusion. Understanding preservation of energy metabolism in diseased vs. healthy hearts may help to develop anti-ischaemic strategies effective also in jeopardized myocardium. METHODS AND RESULTS Isolated infarct-remodelled/sham Sprague-Dawley rat hearts were perfused in the working mode and subjected to 15 min of ischaemia and 30 min of reperfusion. Protection of post-ischaemic ventricular work was achieved by pharmacological conditioning with sevoflurane. Oxidative metabolism was measured by substrate flux in fatty acid and glucose oxidation using [(3)H]palmitate and [(14)C]glucose. Mitochondrial oxygen consumption was measured in saponin-permeabilized left ventricular muscle fibres. Activity assays of citric acid synthase, hydroxyacyl-CoA dehydrogenase, and pyruvate dehydrogenase and mass spectrometry for acylcarnitine profiling were also performed. Six weeks after coronary artery ligation, the hearts exhibited macroscopic and molecular signs of hypertrophy consistent with remodelling and limited respiratory chain and citric acid cycle capacity. Unprotected remodelled hearts showed a marked decline in palmitate oxidation and acetyl-CoA energy production after ischaemia/reperfusion, which normalized in sevoflurane-protected remodelled hearts. Protected remodelled hearts also showed higher β-oxidation flux as determined by increased oxygen consumption with palmitoylcarnitine/malate in isolated fibres and a lower ratio of C16:1+C16OH/C14 carnitine species, indicative of a higher long-chain hydroxyacyl-CoA dehydrogenase activity. Remodelled hearts exhibited higher PPARα-PGC-1α but defective HIF-1α signalling, and conditioning enabled them to mobilize fatty acids from endogenous triglyceride stores, which closely correlated with improved recovery. CONCLUSIONS Protected infarct-remodelled hearts secure post-ischaemic energy production by activation of β-oxidation and mobilization of fatty acids from endogenous triglyceride stores.
Collapse
Affiliation(s)
- Phing-How Lou
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Oka T, Lam VH, Zhang L, Keung W, Cadete VJJ, Samokhvalov V, Tanner BA, Beker DL, Ussher JR, Huqi A, Jaswal JS, Rebeyka IM, Lopaschuk GD. Cardiac hypertrophy in the newborn delays the maturation of fatty acid β-oxidation and compromises postischemic functional recovery. Am J Physiol Heart Circ Physiol 2012; 302:H1784-94. [PMID: 22408020 DOI: 10.1152/ajpheart.00804.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During the neonatal period, cardiac energy metabolism progresses from a fetal glycolytic profile towards one more dependent on mitochondrial oxidative metabolism. In this study, we identified the effects of cardiac hypertrophy on neonatal cardiac metabolic maturation and its impact on neonatal postischemic functional recovery. Seven-day-old rabbits were subjected to either a sham or a surgical procedure to induce a left-to-right shunt via an aortocaval fistula to cause RV volume-overload. At 3 wk of age, hearts were isolated from both groups and perfused as isolated, biventricular preparations to assess cardiac energy metabolism. Volume-overload resulted in cardiac hypertrophy (16% increase in cardiac mass, P < 0.05) without evidence of cardiac dysfunction in vivo or in vitro. Fatty acid oxidation rates were 60% lower (P < 0.05) in hypertrophied hearts than controls, whereas glycolysis increased 246% (P < 0.05). In contrast, glucose and lactate oxidation rates were unchanged. Overall ATP production rates were significantly lower in hypertrophied hearts, resulting in increased AMP-to-ATP ratios in both aerobic hearts and ischemia-reperfused hearts. The lowered energy generation of hypertrophied hearts depressed functional recovery from ischemia. Decreased fatty acid oxidation rates were accompanied by increased malonyl-CoA levels due to decreased malonyl-CoA decarboxylase activity/expression. Increased glycolysis in hypertrophied hearts was accompanied by a significant increase in hypoxia-inducible factor-1α expression, a key transcriptional regulator of glycolysis. Cardiac hypertrophy in the neonatal heart results in a reemergence of the fetal metabolic profile, which compromises ATP production in the rapidly maturing heart and impairs recovery of function following ischemia.
Collapse
Affiliation(s)
- Tatsujiro Oka
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, Departments of Pediatrics and Surgery, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Jaswal JS, Lund CR, Keung W, Beker DL, Rebeyka IM, Lopaschuk GD. Isoproterenol stimulates 5'-AMP-activated protein kinase and fatty acid oxidation in neonatal hearts. Am J Physiol Heart Circ Physiol 2010; 299:H1135-45. [PMID: 20656883 DOI: 10.1152/ajpheart.00186.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
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 O(2) 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.
Collapse
Affiliation(s)
- Jagdip S Jaswal
- Department of Pediatrics, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | | | |
Collapse
|