1
|
Raph SM, Calderin EP, Nong Y, Brittian K, Garrett L, Zhang D, Nystoriak MA. Kv beta complex facilitates exercise-induced augmentation of myocardial perfusion and cardiac growth. Front Cardiovasc Med 2024; 11:1411354. [PMID: 38978788 PMCID: PMC11228310 DOI: 10.3389/fcvm.2024.1411354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/21/2024] [Indexed: 07/10/2024] Open
Abstract
The oxygen sensitivity of voltage-gated potassium (Kv) channels regulates cardiovascular physiology. Members of the Kv1 family interact with intracellular Kvβ proteins, which exhibit aldo-keto reductase (AKR) activity and confer redox sensitivity to Kv channel gating. The Kvβ proteins contribute to vasoregulation by controlling outward K+ currents in smooth muscle upon changes in tissue oxygen consumption and demand. Considering exercise as a primary physiological stimulus of heightened oxygen demand, the current study tested the role of Kvβ proteins in exercise performance, exercise-induced adaptations in myocardial perfusion, and physiological cardiac growth. Our findings reveal that genetic ablation of Kvβ2 proteins diminishes baseline exercise capacity in mice and attenuates the enhancement in exercise performance observed after long-term training. Moreover, we demonstrate that Kvβ2 proteins are critical for exercise-mediated enhancement in myocardial perfusion during cardiac stress as well as adaptive changes in cardiac structure. Our results underscore the importance of Kvβ proteins in metabolic vasoregulation, highlighting their role in modulating both exercise capacity and cardiovascular benefits associated with training. Furthermore, our study sheds light on a novel molecular target for enhancing exercise performance and improving the health benefits associated with exercise training in patients with limited capacity for physical activity.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Matthew A. Nystoriak
- Center for Cardiometabolic Science, Department of Medicine, Division of Environmental Medicine, University of Louisville, Louisville, KY, United States
| |
Collapse
|
2
|
Majerczak J, Drzymala‐Celichowska H, Grandys M, Kij A, Kus K, Celichowski J, Krysciak K, Molik WA, Szkutnik Z, Zoladz JA. Exercise Training Decreases Nitrite Concentration in the Heart and Locomotory Muscles of Rats Without Changing the Muscle Nitrate Content. J Am Heart Assoc 2024; 13:e031085. [PMID: 38214271 PMCID: PMC10926815 DOI: 10.1161/jaha.123.031085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/20/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Skeletal muscles are postulated to be a potent regulator of systemic nitric oxide homeostasis. In this study, we aimed to evaluate the impact of physical training on the heart and skeletal muscle nitric oxide bioavailability (judged on the basis of intramuscular nitrite and nitrate) in rats. METHODS AND RESULTS Rats were trained on a treadmill for 8 weeks, performing mainly endurance running sessions with some sprinting runs. Muscle nitrite (NO2-) and nitrate (NO3-) concentrations were measured using a high-performance liquid chromatography-based method, while amino acids, pyruvate, lactate, and reduced and oxidized glutathione were determined using a liquid chromatography coupled with tandem mass spectrometry technique. The content of muscle nitrite reductases (electron transport chain proteins, myoglobin, and xanthine oxidase) was assessed by western immunoblotting. We found that 8 weeks of endurance training decreased basal NO2- in the locomotory muscles and in the heart, without changes in the basal NO3-. In the slow-twitch oxidative soleus muscle, the decrease in NO2- was already present after the first week of training, and the content of nitrite reductases remained unchanged throughout the entire period of training, except for the electron transport chain protein content, which increased no sooner than after 8 weeks of training. CONCLUSIONS Muscle NO2- level, opposed to NO3-, decreases in the time course of training. This effect is rapid and already visible in the slow-oxidative soleus after the first week of training. The underlying mechanisms of training-induced muscle NO2- decrease may involve an increase in the oxidative stress, as well as metabolite changes related to an increased muscle anaerobic glycolytic activity contributing to (1) direct chemical reduction of NO2- or (2) activation of muscle nitrite reductases.
Collapse
Affiliation(s)
- Joanna Majerczak
- Chair of Exercise Physiology and Muscle Bioenergetics, Faculty of Health SciencesJagiellonian University Medical CollegeKrakowPoland
| | - Hanna Drzymala‐Celichowska
- Department of Neurobiology, Faculty of Health SciencesPoznan University of Physical EducationPoznanPoland
- Department of Physiology and Biochemistry, Faculty of Health SciencesPoznan University of Physical EducationPoznanPoland
| | - Marcin Grandys
- Chair of Exercise Physiology and Muscle Bioenergetics, Faculty of Health SciencesJagiellonian University Medical CollegeKrakowPoland
| | - Agnieszka Kij
- Jagiellonian Centre for Experimental Therapeutics (JCET)Jagiellonian UniversityKrakowPoland
| | - Kamil Kus
- Jagiellonian Centre for Experimental Therapeutics (JCET)Jagiellonian UniversityKrakowPoland
| | - Jan Celichowski
- Department of Neurobiology, Faculty of Health SciencesPoznan University of Physical EducationPoznanPoland
| | - Katarzyna Krysciak
- Department of Neurobiology, Faculty of Health SciencesPoznan University of Physical EducationPoznanPoland
| | - Weronika A. Molik
- Chair of Exercise Physiology and Muscle Bioenergetics, Faculty of Health SciencesJagiellonian University Medical CollegeKrakowPoland
- University of FloridaGainesvilleFLUSA
| | | | - Jerzy A. Zoladz
- Chair of Exercise Physiology and Muscle Bioenergetics, Faculty of Health SciencesJagiellonian University Medical CollegeKrakowPoland
| |
Collapse
|
3
|
Bioactive Peptides and Exercise Modulate the AMPK/SIRT1/PGC-1α/FOXO3 Pathway as a Therapeutic Approach for Hypertensive Rats. Pharmaceuticals (Basel) 2022; 15:ph15070819. [PMID: 35890118 PMCID: PMC9319799 DOI: 10.3390/ph15070819] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 02/05/2023] Open
Abstract
Peptides are fragments of fundamental protein sequences that may have health benefits in addition to basic dietary benefits. Recently, we have reported on the pharmacological benefits of alcalase potato protein hydrolysate (APPH) and bioactive peptides isolated from APPH. The aim was to evaluate the synergistic effect of exercise along with DIKTNKPVIF (DF) peptides in ameliorating hypertension in spontaneously hypertensive rat (SHR) rats. We examined ECG parameters, lipid profiles, cardiac markers, and histology, and quantified the proteins associated with fibrosis, hypertrophy, apoptosis, mitochondrial biogenesis, and longevity pathways. DF peptide administration, along with exercise, reduced the blood pressure and cardiac marker levels in serum. Furthermore, it also suppressed the expression of fibrosis markers COL1A1, CTGF, and uPA and downregulated cardiac-hypertrophy-associated markers such as calcineurin, NFATC3, GATA4, pGATA4 and BNP. Exercise synergistically increases the expression of IFG1, PI3K, and AKT cell-survival pathway proteins, along with DF administration. Moreover, AMPK/SIRT1/PGC-1α/FOXO3 pathway protein expression was increased with the combinatorial administration of DF and exercise. Our data suggest that exercise, along with DF peptides, act synergistically in alleviating hypertension by activating the mitochondrial biogenesis pathway.
Collapse
|
4
|
Xiang K, Qin Z, Zhang H, Liu X. Energy Metabolism in Exercise-Induced Physiologic Cardiac Hypertrophy. Front Pharmacol 2020; 11:1133. [PMID: 32848751 PMCID: PMC7403221 DOI: 10.3389/fphar.2020.01133] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/13/2020] [Indexed: 12/17/2022] Open
Abstract
Physiologic hypertrophy of the heart preserves or enhances systolic function without interstitial fibrosis or cell death. As a unique form of physiological stress, regular exercise training can trigger the adaptation of cardiac muscle to cause physiological hypertrophy, partly due to its ability to improve cardiac metabolism. In heart failure (HF), cardiac dysfunction is closely associated with early initiation of maladaptive metabolic remodeling. A large amount of clinical and experimental evidence shows that metabolic homeostasis plays an important role in exercise training, which is conducive to the treatment and recovery of cardiovascular diseases. Potential mechanistic targets for modulation of cardiac metabolism have become a hot topic at present. Thus, exploring the energy metabolism mechanism in exercise-induced physiologic cardiac hypertrophy may produce new therapeutic targets, which will be helpful to design novel effective strategies. In this review, we summarize the changes of myocardial metabolism (fatty acid metabolism, carbohydrate metabolism, and mitochondrial adaptation), metabolically-related signaling molecules, and probable regulatory mechanism of energy metabolism during exercise-induced physiological cardiac hypertrophy.
Collapse
Affiliation(s)
- Kefa Xiang
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Zhen Qin
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Huimin Zhang
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Xia Liu
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| |
Collapse
|
5
|
Boulghobra D, Coste F, Geny B, Reboul C. Exercise training protects the heart against ischemia-reperfusion injury: A central role for mitochondria? Free Radic Biol Med 2020; 152:395-410. [PMID: 32294509 DOI: 10.1016/j.freeradbiomed.2020.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/01/2020] [Accepted: 04/07/2020] [Indexed: 12/11/2022]
Abstract
Ischemic heart disease is one of the main causes of morbidity and mortality worldwide. Physical exercise is an effective lifestyle intervention to reduce the risk factors for cardiovascular disease and also to improve cardiac function and survival in patients with ischemic heart disease. Among the strategies that contribute to reduce heart damages during ischemia and reperfusion, regular physical exercise is efficient both in rodent experimental models and in humans. However, the cellular and molecular mechanisms of the cardioprotective effects of exercise remain unclear. During ischemia and reperfusion, mitochondria are crucial players in cell death, but also in cell survival. Although exercise training can influence mitochondrial function, the consequences on heart sensitivity to ischemic insults remain elusive. In this review, we describe the effects of physical activity on cardiac mitochondria and their potential key role in exercise-induced cardioprotection against ischemia-reperfusion damage. Based on recent scientific data, we discuss the role of different pathways that might help to explain why mitochondria are a key target of exercise-induced cardioprotection.
Collapse
Affiliation(s)
| | - Florence Coste
- LAPEC EA4278, Avignon Université, F-84000, Avignon, France
| | - Bernard Geny
- EA3072, «Mitochondrie, Stress Oxydant, et Protection Musculaire», Université de Strasbourg, 67000, Strasbourg, France
| | - Cyril Reboul
- LAPEC EA4278, Avignon Université, F-84000, Avignon, France.
| |
Collapse
|
6
|
Wang X, Fitts RH. Cardiomyocyte slowly activating delayed rectifier potassium channel: regulation by exercise and β-adrenergic signaling. J Appl Physiol (1985) 2020; 128:1177-1185. [DOI: 10.1152/japplphysiol.00802.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Results demonstrate that exercise training (TRN) downregulates ventricular IKs channel current and the channel’s responsiveness to β-agonist factors mediated by TRN-induced decline in channel subunits KCNQ1 and KCNE1 and the A-kinase anchoring protein yotiao. The reduced IKs current helps explain the TRN-induced prolongation of the action potential in basal conditions and, coupled with previously reported upregulation of the KATP channel, results in a more efficient heart that is better able to respond to beat-by-beat changes in metabolism.
Collapse
Affiliation(s)
- Xinrui Wang
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Robert H. Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| |
Collapse
|
7
|
Maternal Treadmill Exercise Reduces the Neurotoxicity of Prenatal Sevoflurane Exposure in Rats via Activation of p300 Histone Acetyltransferase. Neurochem Res 2020; 45:1626-1635. [DOI: 10.1007/s11064-020-03023-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/28/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022]
|
8
|
Gholamnezhad Z, Mégarbane B, Rezaee R. Molecular Mechanisms Mediating Adaptation to Exercise. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1228:45-61. [PMID: 32342449 DOI: 10.1007/978-981-15-1792-1_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several experimental and human studies documented the preventive and therapeutic effects of exercise on the normal physiological function of different body systems during aging as well as various diseases. Recent studies using cellular and molecular (biochemical, proteomics, and genomics) techniques indicated that exercise modifies intracellular and extracellular signaling and pathways. In addition, in vivo or in vitro experiments, particularly, using knockout and transgenic animals, helped to mimic physiological conditions during and after exercise. According to the findings of these studies, some important signaling pathways modulated by exercise are Ca2+-dependent calcineurin/activated nuclear factor of activated T-cells, mammalian target of rapamycin, myostatin/Smad, and AMP-activated protein kinase regulation of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha. Such modulations contribute to cell adaptation and remodeling of muscle fiber type in response to exercise. Despite great improvement in this field, there are still several unanswered questions as well as unfixed issues concerning clinical trials' biases and limitations. Nevertheless, designing multicenter standard clinical trials while considering individual variability and the exercise modality and duration will improve the perspective we have on the mechanisms mediating adaptation to exercise and final outcomes.
Collapse
Affiliation(s)
- Zahra Gholamnezhad
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
- Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Bruno Mégarbane
- Department of Medical and Toxicological Critical Care, Paris-Diderot University, Paris, France
| | - Ramin Rezaee
- Clinical Research Unit, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
9
|
Yeom MY, Cho YO. A 1:1 exercise-to-rest period ratio needed by animals to restore energy sources and replenish anti-oxidative status after exercise. Nutr Res Pract 2019; 13:17-22. [PMID: 30788052 PMCID: PMC6369116 DOI: 10.4162/nrp.2019.13.1.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/04/2018] [Accepted: 10/10/2018] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND/OBJECTIVES Successful recovery of an animal from exercise is essential, especially prior to the next exercise session. This study was conducted to find an effective exercise-to-rest period ratio for the restoration of energy sources and replenishment of anti-oxidative status in tissue after exercise. MATERIALS/METHODS Thirty-two rats were assigned to either non-training or training exercise groups for 5 weeks. After that period, the two groups were subdivided into four smaller groups: non-exercise (NE), exercise 0.5 hour and rest 1 hour (ER0.5:1), exercise 1 hour and rest 1 hour (ER1:1), exercise 2 hours and rest 1 hour (ER2:1). RESULTS In the training group animals and compared to the NE group, the levels of plasma glucose after the rest period were significantly high in all ER groups but highest in the ER2:1 group. Similarly, the liver glycogen level was highest in the ER2:1 group. The plasma FFA level reached the highest level in the ER2:1 group but was similarly high in the ER0.5:1 group. Liver TG level was unchanged in the ER2:1 and ER1:1 groups but was significantly high in the ER0.5:1 group. Muscle TG levels were decreased in all three ER groups. Plasma protein levels were significantly high in the ER2:1 and ER0.5:1 groups. In both training animal and non-training animals, the liver protein levels did not change significantly between the NE and ER groups, irrespective of the exercise-to-rest ratio. In the training animal group, muscle protein level was significantly low in the ER2:1 and ER0.5:1 groups. The activity levels of superoxide dismutase and catalase, as well as the malondialdehyde concentration, were not significantly different between NE and ER groups, irrespective of the exercise-to-rest period ratio. CONCLUSIONS These results indicate that animals provided with a 0.5:1 to 1:1 exercise-to-rest period ratio can restore their muscle energy sources and recover their anti-oxidative defense system.
Collapse
Affiliation(s)
- Ma-Young Yeom
- Department of Food and Nutrition, Duksung Women's University, 33 Samyangro 144, Dobong-Gu, Seoul, 01369, South Korea
| | - Youn-Ok Cho
- Department of Food and Nutrition, Duksung Women's University, 33 Samyangro 144, Dobong-Gu, Seoul, 01369, South Korea
| |
Collapse
|
10
|
Pellegrino FJ, Risso A, Relling AE, Corrada Y. Physical response of dogs supplemented with fish oil during a treadmill training programme. J Anim Physiol Anim Nutr (Berl) 2018; 103:653-660. [PMID: 30520172 DOI: 10.1111/jpn.13033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 10/19/2018] [Accepted: 11/08/2018] [Indexed: 11/25/2022]
Abstract
The rise in popularity of dog sports competitions has led to the evaluation of improvements in dog physical performance. The potential benefit of dietary supplementation with fish oil (FO) on the physical performance of human beings and horses has been reported. However, such effect has not been studied in dogs. We therefore evaluated the effect of FO dietary supplementation on heart rate (HR), rectal temperature (RT) and thigh circumference (TC) in dogs during aerobic treadmill training, and further determined HR response and blood lactate (BL) concentration during an incremental exercise test. Using a cross-over design, eight male dogs were randomly assigned to two groups and received a standard balanced commercial diet (control, CG, n = 7) and the same diet supplemented with 54 mg FO/kg metabolic weight per day (FOG, n = 8). All dogs had 30-min treadmill sessions at 8 km/hr and 7.5% slope twice a week for 12 weeks. Assessment of HR and RT was performed before and immediately after each session; HR was also assessed 5 min after the end of each session. Thigh circumference was evaluated before each session. All dogs performed an incremental exercise test on the treadmill at 0, 6 and 12 weeks to evaluate HR response and BL concentration. Data were analysed using the mixed procedure (SAS 9.4). In FOG, pre-HR (-4.9%) and post-HR (-2.4%) values and post-RT (-0.3%) values were lower during treadmill training, whereas TC (+2.2%) values were higher as compared with CG (p < 0.01). Through the incremental exercise test, mean HR (week 6, -5.3%; week 12, -6.0%) values in FOG were lower than in CG (p < 0.05). In conclusion, FO supplementation slightly improved the physiological response of dogs to exercise during training.
Collapse
Affiliation(s)
- Francisco Javier Pellegrino
- Laboratory of Veterinary Physiotherapy (LAFIVET), School of Veterinary Sciences (FCV), National University of La Plata (UNLP), Buenos Aires, Argentina.,National Council of Research and Technology (CONICET), Buenos Aires, Argentina.,Institute of Veterinary Genetics (IGEVET, UNLP-CONICET LA PLATA), FCV, Buenos Aires, Argentina
| | - Analía Risso
- Laboratory of Veterinary Physiotherapy (LAFIVET), School of Veterinary Sciences (FCV), National University of La Plata (UNLP), Buenos Aires, Argentina.,National Council of Research and Technology (CONICET), Buenos Aires, Argentina.,Institute of Veterinary Genetics (IGEVET, UNLP-CONICET LA PLATA), FCV, Buenos Aires, Argentina
| | | | - Yanina Corrada
- Laboratory of Veterinary Physiotherapy (LAFIVET), School of Veterinary Sciences (FCV), National University of La Plata (UNLP), Buenos Aires, Argentina.,National Council of Research and Technology (CONICET), Buenos Aires, Argentina
| |
Collapse
|
11
|
Boskovic S, Marín-Juez R, Jasnic J, Reischauer S, El Sammak H, Kojic A, Faulkner G, Radojkovic D, Stainier DYR, Kojic S. Characterization of zebrafish (Danio rerio) muscle ankyrin repeat proteins reveals their conserved response to endurance exercise. PLoS One 2018; 13:e0204312. [PMID: 30252882 PMCID: PMC6155536 DOI: 10.1371/journal.pone.0204312] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/05/2018] [Indexed: 12/30/2022] Open
Abstract
Muscle proteins with ankyrin repeats (MARPs) ANKRD1 and ANKRD2 are titin-associated proteins with a putative role as transcriptional co-regulators in striated muscle, involved in the cellular response to mechanical, oxidative and metabolic stress. Since many aspects of the biology of MARPs, particularly exact mechanisms of their action, in striated muscle are still elusive, research in this field will benefit from novel animal model system. Here we investigated the MARPs found in zebrafish for protein structure, evolutionary conservation, spatiotemporal expression profiles and response to increased muscle activity. Ankrd1 and Ankrd2 show overall moderate conservation at the protein level, more pronounced in the region of ankyrin repeats, motifs indispensable for their function. The two zebrafish genes, ankrd1a and ankrd1b, counterparts of mammalian ANKRD1/Ankrd1, have different expression profiles during first seven days of development. Mild increase of ankrd1a transcript levels was detected at 72 hpf (1.74±0.24 fold increase relative to 24 hpf time point), while ankrd1b expression was markedly upregulated from 24 hpf onward and peaked at 72 hpf (92.18±36.95 fold increase relative to 24 hpf time point). Spatially, they exhibited non-overlapping expression patterns during skeletal muscle development in trunk (ankrd1a) and tail (ankrd1b) somites. Expression of ankrd2 was barely detectable. Zebrafish MARPs, expressed at a relatively low level in adult striated muscle, were found to be responsive to endurance exercise training consisting of two bouts of 3 hours of forced swimming daily, for five consecutive days. Three hours after the last exercise bout, ankrd1a expression increased in cardiac muscle (6.19±5.05 fold change), while ankrd1b and ankrd2 were upregulated in skeletal muscle (1.97±1.05 and 1.84±0.58 fold change, respectively). This study provides the foundation to establish zebrafish as a novel in vivo model for further investigation of MARPs function in striated muscle.
Collapse
Affiliation(s)
- Srdjan Boskovic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Rubén Marín-Juez
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Jovana Jasnic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Sven Reischauer
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Hadil El Sammak
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Ana Kojic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | | | - Dragica Radojkovic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Didier Y. R. Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Snezana Kojic
- Laboratory for Molecular Biology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
- * E-mail:
| |
Collapse
|
12
|
Fulghum K, Hill BG. Metabolic Mechanisms of Exercise-Induced Cardiac Remodeling. Front Cardiovasc Med 2018; 5:127. [PMID: 30255026 PMCID: PMC6141631 DOI: 10.3389/fcvm.2018.00127] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/23/2018] [Indexed: 12/13/2022] Open
Abstract
Exercise has a myriad of physiological benefits that derive in part from its ability to improve cardiometabolic health. The periodic metabolic stress imposed by regular exercise appears fundamental in driving cardiovascular tissue adaptation. However, different types, intensities, or durations of exercise elicit different levels of metabolic stress and may promote distinct types of tissue remodeling. In this review, we discuss how exercise affects cardiac structure and function and how exercise-induced changes in metabolism regulate cardiac adaptation. Current evidence suggests that exercise typically elicits an adaptive, beneficial form of cardiac remodeling that involves cardiomyocyte growth and proliferation; however, chronic levels of extreme exercise may increase the risk for pathological cardiac remodeling or sudden cardiac death. An emerging theme underpinning acute as well as chronic cardiac adaptations to exercise is metabolic periodicity, which appears important for regulating mitochondrial quality and function, for stimulating metabolism-mediated exercise gene programs and hypertrophic kinase activity, and for coordinating biosynthetic pathway activity. In addition, circulating metabolites liberated during exercise trigger physiological cardiac growth. Further understanding of how exercise-mediated changes in metabolism orchestrate cell signaling and gene expression could facilitate therapeutic strategies to maximize the benefits of exercise and improve cardiac health.
Collapse
Affiliation(s)
- Kyle Fulghum
- Department of Medicine, Envirome Institute, Institute of Molecular Cardiology, Diabetes and Obesity Center, Louisville, KY, United States
- Department of Physiology, University of Louisville, Louisville, KY, United States
| | - Bradford G. Hill
- Department of Medicine, Envirome Institute, Institute of Molecular Cardiology, Diabetes and Obesity Center, Louisville, KY, United States
| |
Collapse
|
13
|
Abstract
Research has demonstrated that the high capacity requirements of the heart are satisfied by a preference for oxidation of fatty acids. However, it is well known that a stressed heart, as in pathological hypertrophy, deviates from its inherent profile and relies heavily on glucose metabolism, primarily achieved by an acceleration in glycolysis. Moreover, it has been suggested that the chronically lipid overloaded heart augments fatty acid oxidation and triglyceride synthesis to an even greater degree and, thus, develops a lipotoxic phenotype. In comparison, classic studies in exercise physiology have provided a basis for the acute metabolic changes that occur during physical activity. During an acute bout of exercise, whole body glucose metabolism increases proportionately to intensity while fatty acid metabolism gradually increases throughout the duration of activity, particularly during moderate intensity. However, the studies in chronic exercise training are primarily limited to metabolic adaptations in skeletal muscle or to the mechanisms that govern physiological signaling pathways in the heart. Therefore, the purpose of this review is to discuss the precise changes that chronic exercise training elicits on cardiac metabolism, particularly on substrate utilization. Although conflicting data exists, a pattern of enhanced fatty oxidation and normalization of glycolysis emerges, which may be a therapeutic strategy to prevent or regress the metabolic phenotype of the hypertrophied heart. This review also expands on the metabolic adaptations that chronic exercise training elicits in amino acid and ketone body metabolism, which have become of increased interest recently. Lastly, challenges with exercise training studies, which could relate to several variables including model, training modality, and metabolic parameter assessed, are examined.
Collapse
Affiliation(s)
- Stephen C. Kolwicz Jr.
- Heart and Muscle Metabolism Laboratory, Health and Exercise Physiology Department, Ursinus College, Collegeville, PA, United States
| |
Collapse
|
14
|
Kolwicz SC. Lipid partitioning during cardiac stress. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1861:1472-80. [PMID: 27040509 DOI: 10.1016/j.bbalip.2016.03.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/18/2016] [Accepted: 03/18/2016] [Indexed: 01/11/2023]
Abstract
It is well documented that fatty acids serve as the primary fuel substrate for the contracting myocardium. However, extensive research has identified significant changes in the myocardial oxidation of fatty acids during acute or chronic cardiac stress. As a result, the redistribution or partitioning of fatty acids due to metabolic derangements could have biological implications. Fatty acids can be stored as triacylglycerols, serve as critical components for biosynthesis of phospholipid membranes, and form the potent signaling molecules, diacylglycerol and ceramides. Therefore, the contribution of lipid metabolism to health and disease is more intricate than a balance of uptake and oxidation. In this review, the available data regarding alterations that occur in endogenous cardiac lipid pathways during the pathological stressors of ischemia-reperfusion and pathological hypertrophy/heart failure are highlighted. In addition, changes in endogenous lipids observed in exercise training models are presented for comparison. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
Collapse
Affiliation(s)
- Stephen C Kolwicz
- Mitochondria and Metabolism Center, University of Washington, School of Medicine, 850 Republican St., Seattle, WA 98109, United States.
| |
Collapse
|
15
|
Proliferation of Human Primary Myoblasts Is Associated with Altered Energy Metabolism in Dependence on Ageing In Vivo and In Vitro. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:8296150. [PMID: 26881042 PMCID: PMC4736420 DOI: 10.1155/2016/8296150] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/08/2015] [Indexed: 12/17/2022]
Abstract
Background. Ageing is associated with suppressed regenerative potential of muscle precursor cells due to decrease of satellite cells and suppressive intramuscular milieu on their activation, associated with ageing-related low-grade inflammation. The aim of the study was to characterize the function of oxidative phosphorylation (OXPHOS), glycolysis, adenylate kinase (AK), and creatine kinase (CK) mediated systems in young and older individuals. Materials and Methods. Myoblasts were cultivated from biopsies taken by transcutaneous conchotomy from vastus lateralis muscle in young (20–29 yrs, n = 7) and older (70–79 yrs, n = 7) subjects. Energy metabolism was assessed in passages 2 to 6 by oxygraphy and enzyme analysis. Results. In myoblasts of young and older subjects the rate of OXPHOS decreased during proliferation from passages 2 to 6. The total activities of CK and AK decreased. Myoblasts of passage 2 cultivated from young muscle showed higher rate of OXPHOS and activities of CK and AK compared to myoblasts from older subjects while hexokinase and pyruvate kinase were not affected by ageing. Conclusions. Proliferation of myoblasts in vitro is associated with downregulation of OXPHOS and energy storage and transfer systems. Ageing in vivo exerts an impact on satellite cells which results in altered metabolic profile in favour of the prevalence of glycolytic pathways over mitochondrial OXPHOS of myoblasts.
Collapse
|
16
|
Bhella PS, Hastings JL, Fujimoto N, Shibata S, Carrick-Ranson G, Palmer MD, Boyd KN, Adams-Huet B, Levine BD. Impact of lifelong exercise "dose" on left ventricular compliance and distensibility. J Am Coll Cardiol 2014; 64:1257-66. [PMID: 25236519 DOI: 10.1016/j.jacc.2014.03.062] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 03/18/2014] [Accepted: 03/26/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND Sedentary aging has deleterious effects on the cardiovascular system, including decreased left ventricular compliance and distensibility (LVCD). Conversely, Masters level athletes, who train intensively throughout adulthood, retain youthful LVCD. OBJECTIVES The purpose of this study was to test the hypothesis that preservation of LVCD may be possible with moderate lifelong exercise training. METHODS Healthy seniors (n = 102) were recruited from predefined populations, screened for lifelong patterns of exercise training, and stratified into 4 groups: "sedentary" (<2 sessions/week); "casual" (2 to 3 sessions/week); "committed" (4 to 5 sessions/week); and "competitive" Masters level athletes (6 to 7 sessions/week). Right heart catheterization and echocardiography were performed while preload was manipulated using lower body negative pressure and rapid saline infusion to define LV pressure-volume relationships and Frank-Starling curves. RESULTS Peak oxygen uptake and LV mass increased with escalating doses of lifelong exercise, with little change in systolic function. At baseline, LV distensibility was greater in committed (21%) and competitive (36%) exercisers than in sedentary subjects. Group LV stiffness constants (sedentary: 0.062 ± 0.039; casual: 0.079 ± 0.052; committed: 0.055 ± 0.033; and competitive: 0.035 ± 0.033) revealed: 1) increased stiffness in sedentary subjects compared to competitive athletes, whereas lifelong casual exercise had no effect; and 2) greater compliance in committed exercisers than in sedentary or casual exercisers. CONCLUSIONS Low doses of casual, lifelong exercise do not prevent the decreased compliance and distensibility observed with healthy, sedentary aging. In contrast, 4 to 5 exercise sessions/week throughout adulthood prevent most of these age-related changes. As LV stiffening has been implicated in the pathophysiology of many cardiovascular conditions affecting the elderly, this "dose" of exercise training may have important implications for prevention of cardiovascular disease.
Collapse
Affiliation(s)
- Paul S Bhella
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas; John Peter Smith Health Network, Fort Worth, Texas
| | - Jeffrey L Hastings
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Naoki Fujimoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Shigeki Shibata
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Graeme Carrick-Ranson
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - M Dean Palmer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | - Kara N Boyd
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas
| | | | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas; University of Texas-Southwestern Medical Center at Dallas, Dallas, Texas.
| |
Collapse
|
17
|
Choi EY, Cho YO. The influence of different durations of aerobic exercise on fuel utilization, lactate level and antioxidant defense system in trained rats. Nutr Res Pract 2014; 8:27-32. [PMID: 24611102 PMCID: PMC3944152 DOI: 10.4162/nrp.2014.8.1.27] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 12/31/2013] [Accepted: 01/06/2014] [Indexed: 11/25/2022] Open
Abstract
This study investigated the influence of different durations of aerobic exercise on fuel utilization, lactate levels and antioxidative status in trained rats. Forty rats underwent physical training (T, n = 20) or non- training (NT, n = 20) for 6 weeks. For physical training, animals exercised on a treadmill for 30 min 5 days per week. At the end of week 6, the animals in each group were subdivided into BE, DE-0.5, DE-1 and DE-2, which were sacrificed at the end of week 6 without having performed exercise or after exercise on a treadmill for 0.5h, 1h and 2h, respectively, immediately before being sacrificed. The plasma glucose level in DE-2 of the NT group was significantly lower than in the other groups. Muscle and liver glycogen levels were significantly lower in DE-1 and DE-2, but there were no significant differences between DE-1 and DE-2 in the T group. Liver protein in DE-2 of the NT group was significantly lower. Muscle TG levels were decreased in DE-0.5 of the T group, while those of the NT group were decreased in DE-1. FFA levels were increased in DE-0.5 of the T group and in DE-1 of the NT group. Lactate levels were increased in DE-0.5 of the NT group, while they were increased in DE-1 of the T group. Catalase activity of the T group was lower in BE but higher in DE-0.5, DE-1 and DE-2. SOD activities were higher in trained rats, while the GSH/GSSG ratios were higher in BE, DE-0.5 and DE-1 in the T group, and there was no difference in that of DE-2. There were no differences in MDA levels in BE and DE-0.5, but they were significantly lower in DE-1 and DE-2 of the T group. Overall, the results of this study, suggest that training may improve exercise performance by facilitating the mobilization and oxidation of fat and conserving limited carbohydrate storage, and that it may delay the onset of fatigue and enhance the antioxidative defense system, but cannot support two hours of vigorous exercise.
Collapse
Affiliation(s)
- Eun-Young Choi
- Department of Food and Nutrition, Duksung Women's University, Ssangmun 419, Dobong-ku, Seoul 132-714, South Korea
| | - Youn-Ok Cho
- Department of Food and Nutrition, Duksung Women's University, Ssangmun 419, Dobong-ku, Seoul 132-714, South Korea
| |
Collapse
|
18
|
Khan RS, Lin Y, Hu Y, Son NH, Bharadwaj KG, Palacios C, Chokshi A, Ji R, Yu S, Homma S, Schulze PC, Tian R, Goldberg IJ. Rescue of heart lipoprotein lipase-knockout mice confirms a role for triglyceride in optimal heart metabolism and function. Am J Physiol Endocrinol Metab 2013; 305:E1339-47. [PMID: 24085031 PMCID: PMC3882371 DOI: 10.1152/ajpendo.00349.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hearts utilize fatty acids as a primary source of energy. The sources of those lipids include free fatty acids and lipoprotein triglycerides. Deletion of the primary triglyceride-hydrolyzing enzyme lipoprotein lipase (LPL) leads to cardiac dysfunction. Whether heart LPL-knockout (hLPL0) mice are compromised due a deficiency in energetic substrates is unknown. To test whether alternative sources of energy will prevent cardiac dysfunction in hLPL0 mice, two different models were used to supply nonlipid energy. 1) hLPL0 mice were crossed with mice transgenically expressing GLUT1 in cardiomyocytes to increase glucose uptake into the heart; this cross-corrected cardiac dysfunction, reduced cardiac hypertrophy, and increased myocardial ATP. 2) Mice were randomly assigned to a sedentary or training group (swimming) at 3 mo of age, which leads to increased skeletal muscle production of lactate. hLPL0 mice had greater expression of the lactate transporter monocarboxylate transporter-1 (MCT-1) and increased cardiac lactate uptake. Compared with hearts from sedentary hLPL0 mice, hearts from trained hLPL0 mice had adaptive hypertrophy and improved cardiac function. We conclude that defective energy intake and not the reduced uptake of fat-soluble vitamins or cholesterol is responsible for cardiac dysfunction in hLPL0 mice. In addition, our studies suggest that adaptations in cardiac metabolism contribute to the beneficial effects of exercise on the myocardium of patients with heart failure.
Collapse
|
19
|
Choi EY, Cho YO. Interaction of physical trainings and coffee intakes in fuel utilization during exercise in rats. Nutr Res Pract 2013; 7:178-84. [PMID: 23766878 PMCID: PMC3679326 DOI: 10.4162/nrp.2013.7.3.178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 12/23/2022] Open
Abstract
This study investigates the impact of exercises, coffee intakes, and physical trainings on fuel utilization in rats. Ninety-six rats were fed a control diet with either water (C) or coffee (CF; 0.12 g freeze-dried instant coffee/100 g body weight/d). Additionally, the animals go through physical training (TC and TCF) or no training (NTC and NTCF) for 4 weeks. For physical training, animals have to exercise on treadmills for 30 minutes (5 d per week, 15° incline, 0.5-0.8 km/h). At the end of week 4, the animals in each group were subdivided into three exercise groups: before exercise (BE), during exercise (DE), and after exercise (AE). The DE rats exercised on treadmills for 1 hour immediately before being sacrificed. Hemoglobin, hematocrit, glucose, glycogen, protein, triglyceride (TG), and free fatty acid (FFA) levels in the plasma, liver, and skeletal muscle of the rats were compared accordingly. Organ weights were also measured. Coffee-training interaction had a significant impact on heart weight, visceral fat, hemoglobin, hematocrit, liver glycogen in DE and AE, and liver triglyceride in DE and AE. Exercise (meaning exercised on a treadmill for 1 hour immediately before being sacrificed) training interaction was significant in liver glycogen, muscle glycogen in control diet and control diet with coffee, FFA and muscle TG levels at control diet with coffee group. Exercise-coffee interactions significantly influenced the FFA with no training groups. Exercise-coffee-training interaction significantly effects on FFA, Liver TG and Muscle TG. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee can be an effective ergogenic aid during exercise for physically trained rats.
Collapse
Affiliation(s)
- Eun-Young Choi
- Department of Food and Nutrition, Duksung Women's University, 419 Ssangmun-dong, Dobong-gu, Seoul 132-714, Korea
| | | |
Collapse
|
20
|
Zhou LY, Liu JP, Wang K, Gao J, Ding SL, Jiao JQ, Li PF. Mitochondrial function in cardiac hypertrophy. Int J Cardiol 2012; 167:1118-25. [PMID: 23044430 DOI: 10.1016/j.ijcard.2012.09.082] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 08/24/2012] [Accepted: 09/15/2012] [Indexed: 10/27/2022]
Abstract
Cardiac hypertrophic program is a chronic, complex process, and occurs in response to long-term increases of hemodynamic load related to a variety of pathophysiological conditions. Mitochondria, known as "the cellular power plants", occupy about one-third of cardiomyocyte volume and supply roughly 90% of the adenosine triphosphate (ATP). Impairment of energy metabolism has been regarded as one of the main pathogenesis of cardiac hypertrophy. Thus, we summarize here the molecular events of mitochondrial adaptations, including the mitochondrial genesis, ATP generation, ROS signaling and Ca(2+) homeostasis in cardiac hypertrophy, expecting that this effort will shed new light on understanding the maladaptive cardiac remodeling.
Collapse
Affiliation(s)
- Lu-Yu Zhou
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | | | | | | | | | | | | |
Collapse
|
21
|
Budiono BP, See Hoe LE, Peart JN, Sabapathy S, Ashton KJ, Haseler LJ, Headrick JP. Voluntary running in mice beneficially modulates myocardial ischemic tolerance, signaling kinases, and gene expression patterns. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1091-100. [DOI: 10.1152/ajpregu.00406.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Exercise triggers hormesis, conditioning hearts against damaging consequences of subsequent ischemia-reperfusion (I/R). We test whether “low-stress” voluntary activity modifies I/R tolerance and molecular determinants of cardiac survival. Male C57BL/6 mice were provided 7-day access to locked (7SED) or rotating (7EX) running-wheels before analysis of cardiac prosurvival (Akt, ERK 1/2) and prodeath (GSK3β) kinases, transcriptomic adaptations, and functional tolerance of isolated hearts to 25-min ischemia/45-min reperfusion. Over 7 days, 7EX mice increased running from 2.1 ± 0.2 to 5.3 ± 0.3 km/day (mean speed 38 ± 2 m/min), with activity improving myocardial I/R tolerance: 7SED hearts recovered 43 ± 3% of ventricular force with diastolic contracture of 33 ± 3 mmHg, whereas 7EX hearts recovered 63 ± 5% of force with diastolic dysfunction reduced to 23 ± 2 mmHg ( P < 0.05). Cytosolic expression (total protein) of Akt and GSK3β was unaltered, while ERK 1/2 increased 30% in 7EX vs. 7SED hearts. Phosphorylation of Akt and ERK 1/2 was unaltered, whereas GSK3β phosphorylation increased ∼90%. Microarray interrogation identified significant changes (≥1.3-fold expression change, ≤5% FDR) in 142 known genes, the majority (92%) repressed. Significantly modified paths/networks related to inflammatory/immune function (particularly interferon-dependent), together with cell movement, growth, and death. Of only 14 induced transcripts, 3 encoded interrelated sarcomeric proteins titin, α-actinin, and myomesin-2, while transcripts for protective actin-stabilizing ND1-L and activator of mitochondrial biogenesis ALAS1 were also induced. There was no transcriptional evidence of oxidative heat-shock or other canonical “stress” responses. These data demonstrate that relatively brief voluntary activity substantially improves cardiac ischemic tolerance, an effect independent of shifts in Akt, but associated with increased total ERK 1/2 and phospho-inhibition of GSK3β. Transcriptomic data implicate inflammatory/immune and sarcomeric modulation in activity-dependent protection.
Collapse
Affiliation(s)
- Boris P. Budiono
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| | - Louise E. See Hoe
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| | - Jason N. Peart
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| | - Surendran Sabapathy
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| | - Kevin J. Ashton
- Faculty of Health Sciences and Medicine, Bond University, Robina, Queensland, Australia
| | - Luke J. Haseler
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| | - John P. Headrick
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia; and
| |
Collapse
|
22
|
Richters L, Lange N, Renner R, Treiber N, Ghanem A, Tiemann K, Scharffetter-Kochanek K, Bloch W, Brixius K. Exercise-induced adaptations of cardiac redox homeostasis and remodeling in heterozygous SOD2-knockout mice. J Appl Physiol (1985) 2011; 111:1431-40. [DOI: 10.1152/japplphysiol.01392.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A reduced expression of the manganese-dependent superoxide dismutase (SOD2) is characterized by increased cardiac oxidative stress. Oxidative stress has also been described in situations of physical exercise. We investigated the influence of physical exercise (EX; treadmill 1 h/day at 15 m/min, 5 days/wk, at an angle of 5° for a duration of 8 wk) on cardiac function [heart frequency (HF), echocardiography, morphometry], oxidative stress [reactive oxygen species (ROS)], and antioxidative defence capacity (peroxiredoxin 1–6) in male SOD2-knockout (SOD2_EX) and wild-type mice (WT_EX) compared with untrained age-matched animals (WT_CON; SOD2_CON). In SOD2_CON, heart weight, cardiomyocyte diameter, and cardiac ROS were significantly larger and peroxiredoxin isoforms 4–6 lower than in WT_CON. The vessel-to-cardiomyocyte ratio, cardiac VEGF-concentration, and cardiac function were similar in SOD2_CON and WT_CON. Both groups tolerated the exercise protocol well. In WT, exercise significantly increased vessel-to-cardiomyocyte ratio and ROS-generation and downregulated peroxiredoxin isoforms 4–6 and VEGF generation. The vessel-to-cardiomyocyte ratio, cardiac VEGF concentration, and cardiac ROS were not altered in SOD2_EX compared with SOD2_CON, but a significant upregulation of cardiac peroxiredoxin 1 and 4 was observed. Similar to the result observed in WT_EX, peroxiredoxin 3 was upregulated in SOD2_EX. Chronic exercise shifted the (mal)adaptive hypertrophic into a compensated dilated cardiac phenotype in SOD2_EX. In conclusion, downregulation of SOD2 induces a maladaptive cardiac hypertrophy. In this situation, physical exercise results in a further deterioration of cardiac remodeling despite an upregulation of the antioxidative defense system.
Collapse
Affiliation(s)
- L. Richters
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiology and Sport Medicine, German Sport University Cologne, Cologne
- Department of Obstetrics and Gynecology, University Hospital of Cologne, Cologne, Germany
| | - N. Lange
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiology and Sport Medicine, German Sport University Cologne, Cologne
- Department of Obstetrics and Gynecology, University Hospital of Cologne, Cologne, Germany
| | - R. Renner
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiology and Sport Medicine, German Sport University Cologne, Cologne
| | - N. Treiber
- Department of Dermatology and Allergology, University of Ulm, Ulm
| | - A. Ghanem
- Clinic and Policlinic II, University of Bonn, Bonn
| | - K. Tiemann
- University Hospital of Muenster, Department of Cardiology and Angiology, Muenster; and
| | | | - W. Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiology and Sport Medicine, German Sport University Cologne, Cologne
| | - K. Brixius
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiology and Sport Medicine, German Sport University Cologne, Cologne
| |
Collapse
|
23
|
Martherus RSRM, Vanherle SJV, Timmer EDJ, Zeijlemaker VA, Broers JL, Smeets HJ, Geraedts JP, Ayoubi TAY. Electrical signals affect the cardiomyocyte transcriptome independently of contraction. Physiol Genomics 2010; 42A:283-9. [PMID: 20858713 DOI: 10.1152/physiolgenomics.00182.2009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cardiomyocytes in vivo are continuously subjected to electrical signals that evoke contractions and instigate drastic changes in the cells' morphology and function. Studies on how electrical stimulation affects the cardiac transcriptome have remained limited to a small number of heart-specific genes. Furthermore, these studies have ignored the interplay between the electrical excitation and the subsequent contractions. We carried out a genomewide assessment of the effects of electrical signaling on gene expression, while distinguishing between the effects deriving from the electrical pulses themselves and the effects instigated by the evoked contractions. Changes in gene expression in primary cultures of neonatal ventricular cardiomyocytes from Lewis Rattus norvegicus were investigated with microarrays and RT-quantitative PCR (QPCR). A series of experiments was included in which the culture medium was supplemented with the contraction inhibitor blebbistatin to allow for electrical stimulation in the absence of contraction. Electrical stimulation was shown to directly enhance calcium handling and induce cardiomyocyte differentiation by arresting cell division and activating key cardiac transcription factors as well as additional differentiation mechanisms such as wnt signaling. Several genes involved in metabolism were also directly activated by electrical stimulation. Furthermore, our data suggest that contraction exerts negative feedback on the transcription of various genes. Together, these observations indicate that intercellular electric currents between adjacent cardiomyocytes have an important role in cardiomyocyte development. They act at least partially through a pulse-specific gene expression program that is activated independently from the evoked contractions.
Collapse
|
24
|
Abstract
This review focuses on the evidence accumulated in humans and animal models to the effect that mitochondria are key players in the progression of heart failure (HF). Mitochondria are the primary source of energy in the form of adenosine triphosphate that fuels the contractile apparatus, and are thus essential for the pumping activity of the heart. We evaluate changes in mitochondrial morphology and alterations in the main components of mitochondrial energetics, such as substrate utilization and oxidative phosphorylation coupled with the level of respirasomes, in the context of their contribution to the chronic energy deficit and mechanical dysfunction in HF.
Collapse
Affiliation(s)
- Mariana G Rosca
- Center for Mitochondrial Diseases, Case Western Reserve University, Cleveland, OH, USA
| | | |
Collapse
|
25
|
Cai MC, Huang QY, Liao WG, Wu Z, Liu FY, Gao YQ. Hypoxic training increases metabolic enzyme activity and composition of alpha-myosin heavy chain isoform in rat ventricular myocardium. Eur J Appl Physiol 2009; 108:105-11. [PMID: 19756706 DOI: 10.1007/s00421-009-1189-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2009] [Indexed: 02/01/2023]
Abstract
Cardiac muscle adaptation is essential for maintaining physical capacity after ascending to high altitude. This study examines the effects of high altitude training on myocardial metabolic enzyme activity and composition of alpha-myosin heavy chain (MHC). Rats were randomly divided into normobaric sedentary (NS) and training (NT) groups, and hypobaric sedentary (HS) and training (HT) groups. HS and HT rats were exposed to hypobaric hypoxia (simulated 4,000-5,000 m) for 5 weeks (24 h/day), and HT rats simultaneously received swim training. Hypoxia exposure for 5 weeks led to a decrease in succinate dehydrogenase (SDH) and citrate synthase (CS) activities in the left ventricle (LV), and a decrease in CS, hexokinase (HK) and total lactate dehydrogenase (LDH) activities in the right ventricle (RV) (p < 0.05, HS vs. NS). Furthermore, 1 h/day swim training during hypoxia exposure enhanced the CS activity in LV and the SDH and CS activities in RV (p < 0.05, HT vs. HS). The percentages of alpha-MHC in both ventricles in HT were higher than those in HS (p < 0.05). We conclude that exercise training at high altitude is beneficial for cardiac muscle adaptation to hypoxia by increasing activities of enzymes and percentage of alpha-MHC. This may contribute to improved cardiac function and work capacity at high altitude.
Collapse
Affiliation(s)
- Ming-Chun Cai
- Department of Pathophysiology and High Altitude Physiology, Key Laboratory of High Altitude Medicine, Ministry of Educative, Third Military Medical University, Chongqing, China
| | | | | | | | | | | |
Collapse
|
26
|
Ventura-Clapier R. Exercise training, energy metabolism, and heart failure. Appl Physiol Nutr Metab 2009; 34:336-9. [PMID: 19448695 DOI: 10.1139/h09-013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Energy metabolism is at the crossroad of cell function and dysfunction. Cardiac and skeletal muscle cells, the energy metabolism of which is high, fluctuating, and adaptable to the special needs of the body, have developed sophisticated strategies for synthesizing, transferring, and utilizing energy in accordance with the needs of the body. Adaptation to endurance training mainly involves energetic remodelling in skeletal muscles, but less is known for the cardiac muscle. Alterations in energy metabolism participate in many pathophysiological processes, among which is heart failure. Because endurance training improves symptoms and quality of life and decreases mortality rate and hospitalization, it is increasingly recognized as a beneficial practice for heart failure patients. The mechanisms involved in the beneficial effects of exercise training are far from being understood. Proper evaluation of these mechanisms is thus a major health issue for populations living in industrialized countries. This review mainly focuses on oxidative metabolism and intracellular energy transfer in muscles and the heart, their alterations in heart failure, and the effects of endurance exercise training.
Collapse
Affiliation(s)
- Renée Ventura-Clapier
- INSERM, U-769, Chatenay-Malabry, Universite Paris-Sud, Chatenay-Malabry, Paris, France.
| |
Collapse
|
27
|
Rimbaud S, Garnier A, Ventura-Clapier R. Mitochondrial biogenesis in cardiac pathophysiology. Pharmacol Rep 2009; 61:131-8. [PMID: 19307701 DOI: 10.1016/s1734-1140(09)70015-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 01/21/2009] [Indexed: 10/25/2022]
Abstract
Cardiac performance depends on a fine balance between the work the heart has to perform to satisfy the needs of the body and the energy that it is able to produce. Thus, energy production by oxidative metabolism, the main energy source of the cardiac muscle, has to be strictly regulated to adapt to cardiac work. Mitochondrial biogenesis is the mechanism responsible for mitochondrial component synthesis and assembly. This process controls mitochondrial content and thus correlates with energy production that, in turn, sustains cardiac contractility. Mitochondrial biogenesis should be finely controlled to match cardiac growth and cardiac work. When the heart is subjected to an increase in work in response to physiological and pathological challenges, it adapts by increasing its mass and expressing a new genetic program. In response to physiological stimuli such as endurance training, mitochondrial biogenesis seems to follow a program involving increased cardiac mass. But in the context of pathological hypertrophy, the modifications of this mechanism remain unclear. What appears clear is that mitochondrial biogenesis is altered in heart failure, and the imbalance between cardiac work demand and energy production represents a major factor in the development of heart failure.
Collapse
|
28
|
|
29
|
Hippocampal metabolic proteins are modulated in voluntary and treadmill exercise rats. Exp Neurol 2008; 212:145-51. [DOI: 10.1016/j.expneurol.2008.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/03/2008] [Accepted: 03/15/2008] [Indexed: 01/15/2023]
|
30
|
Sun B, Wang JH, Lv YY, Zhu SS, Yang J, Ma JZ. Proteomic adaptation to chronic high intensity swimming training in the rat heart. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2008; 3:108-17. [DOI: 10.1016/j.cbd.2007.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2007] [Revised: 11/23/2007] [Accepted: 11/23/2007] [Indexed: 01/07/2023]
|
31
|
Knott EM, Sun J, Lei Y, Ryou MG, Olivencia-Yurvati AH, Mallet RT. Pyruvate mitigates oxidative stress during reperfusion of cardioplegia-arrested myocardium. Ann Thorac Surg 2006; 81:928-34. [PMID: 16488697 DOI: 10.1016/j.athoracsur.2005.08.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 08/24/2005] [Accepted: 08/25/2005] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cardioplegic arrest and reperfusion of the myocardium imposes oxidative stress that could potentially inactivate metabolic enzymes and compromise energy production. This study determined the impact of cardioplegic arrest and reperfusion on activities of several oxidant-sensitive enzymes, and tested whether pyruvate, a natural metabolic fuel and antioxidant, mitigates oxidant stress, protects enzymes, and bolsters myocardial energy state after reperfusion. METHODS In situ swine hearts were arrested for 60 minutes with 4:1 blood:crystalloid cardioplegia, and then reperfused for 3 minutes with cardioplegia-free blood with or without approximately 12 mM pyruvate. Tissue metabolites and enzyme activities were measured in left ventricular myocardium snap frozen at 45 minutes of arrest and 3 minutes of reperfusion. RESULTS The 8-isoprostane content, a measure of lipid peroxidation, sharply increased upon reperfusion, coincident with a 70% decline in redox state of the intracellular antioxidant glutathione. Aconitase and glucose 6-phosphate dehydrogenase activities fell during arrest; creatine kinase and phosphofructokinase were inactivated upon reperfusion. Pyruvate suppressed 8-isoprostane formation, maintained glutathione redox state, and enhanced phosphocreatine phosphorylation potential, a measure of myocardial energy state, during reperfusion. Pyruvate reactivated creatine kinase and aconitase, which are at least partially mitochondrial enzymes, but did not protect the cytosolic enzymes glucose 6-phosphate dehydrogenase and phosphofructokinase. CONCLUSIONS Administration of pyruvate upon reperfusion after cardioplegic arrest mitigates oxidative stress, protects mitochondrial enzymes and increases myocardial energy state. These results support therapeutic application of pyruvate-enhanced reperfusion to prevent cardiac injury after cardioplegic arrest.
Collapse
Affiliation(s)
- E Marty Knott
- Department of Integrative Physiology, University of North Texas Health Science Center, Fort Worth, Texas 76107-2699, USA
| | | | | | | | | | | |
Collapse
|
32
|
Lo ASY, Liew CT, Ngai SM, Tsui SKW, Fung KP, Lee CY, Waye MMY. Developmental regulation and cellular distribution of human cytosolic malate dehydrogenase (MDH1). J Cell Biochem 2005; 94:763-73. [PMID: 15565635 DOI: 10.1002/jcb.20343] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Human cyotsolic malate dehydrogenase (MDH1) is important in transporting NADH equivalents across the mitochondrial membrane, controlling tricarboxylic acid (TCA) cycle pool size and providing contractile function. Cellular localization studies indicate that MDH1 mRNA expression has a strong tissue-specific distribution, being expressed primarily in cardiac and skeletal muscle and in the brain, at intermediate levels in the spleen, kidney, intestine, liver, and testes and at low levels in lung and bone marrow. The observed MDH1 localizations reflect the role of NADH in the support of a variety of functions in different organs. These functions are primarily related to aerobic energy production for muscle contraction, neuronal signal transmission, absorption/resorption functions, collagen-supporting functions, phagocytosis of dead cells, and processes related to gas exchange and cell division. During neonatal development, MDH1 is expressed in human embryonic heart as early as the 3rd month and then is over-expressed from the 5th month until the birth. The expression of MDH1 is maintained in the adult heart but is not present in levels as high as in the fetus. Finally, over-expression of MDH1 is found in left ventricular cardiac muscle of dilated cardiomyopathy (DCM) patients when contrasted to the diseased non-DCM and normal heart muscle by in situ hybridization and Western blot. These observations are compatible with the activation of glucose oxidation in relatively hypoxic environments of fetal and hypertrophied myocardium.
Collapse
Affiliation(s)
- Agnes Shuk-Yee Lo
- Department of Biochemistry, Croucher Laboratory for Human Genomics and The Hong Kong Bioinformatics Center, The Chinese University of Hong Kong, Hong Kong SAR, China
| | | | | | | | | | | | | |
Collapse
|
33
|
Schaeffer PJ, Wende AR, Magee CJ, Neilson JR, Leone TC, Chen F, Kelly DP. Calcineurin and calcium/calmodulin-dependent protein kinase activate distinct metabolic gene regulatory programs in cardiac muscle. J Biol Chem 2004; 279:39593-603. [PMID: 15262994 DOI: 10.1074/jbc.m403649200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To learn more about the targets of Cn (Cn) and calcium/calmodulin-dependent protein kinase in cardiac muscle, we investigated their actions in cultured cardiac myocytes and the hearts of mice in vivo. Adenoviral-mediated expression of constitutively active forms of either pathway induced expression of peroxisome proliferator-activated receptor gamma coactivator 1alpha, a transcriptional coactivator involved in the control of multiple cellular energy metabolic pathways in cardiac myocytes. Transcriptional profiling studies demonstrated that Cn and calcium/calmodulin-dependent protein kinase activate distinct but overlapping metabolic gene regulatory programs. Expression of the nuclear receptor, peroxisome proliferator-activated receptor alpha, was markedly increased by Cn, but not calcium/calmodulin-dependent protein kinase, providing one mechanism whereby cellular fatty acid utilization genes are selectively activated by Cn. Transfection experiments demonstrated that Cn directly activates the mouse peroxisome proliferator-activated receptor alpha gene promoter. Co-transfection "add-back" experiments demonstrated that the transcription factors, myocyte enhancer factors 2C or 2D, were sufficient to confer Cn-mediated activation of the peroxisome proliferator-activated receptor alpha gene. Cn was also shown to directly activate a known peroxisome proliferator-activated receptor alpha target, muscle-type carnitine palmitoyltransferase I, providing a second mechanism by which Cn activates genes of cellular fatty acid utilization. Lastly, the gene expression of peroxisome proliferator-activated receptor gamma coactivator 1alpha and peroxisome proliferator-activated receptor alpha was reduced in the hearts of mice with cardiac-specific ablation of the Cn regulatory subunit. These data support a role for calcium-triggered signaling pathways in the regulation of cardiac energetics and identify pathway-specific control of metabolic targets.
Collapse
Affiliation(s)
- Paul J Schaeffer
- Center for Cardiovascular Research and Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Stolen KQ, Kemppainen J, Kalliokoski KK, Luotolahti M, Viljanen T, Nuutila P, Knuuti J. Exercise training improves insulin-stimulated myocardial glucose uptake in patients with dilated cardiomyopathy. J Nucl Cardiol 2004; 10:447-55. [PMID: 14569237 DOI: 10.1016/s1071-3581(03)00528-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND The effects of exercise training on myocardial substrate utilization have not previously been studied in patients with idiopathic dilated cardiomyopathy and mild heart failure. METHODS AND RESULTS Myocardial glucose uptake was studied in 15 clinically stable patients with dilated cardiomyopathy (New York Heart Association class I-II, ejection fraction 34% +/- 8%) with the use of 2-[fluorine 18]fluoro-2-deoxy-d-glucose ([F-18]FDG) and positron emission tomography under euglycemic hyperinsulinemia. Eight of these patients participated in a 5-month endurance and strength training program, whereas seven patients served as nontrained subjects. Left ventricular function was assessed by 2-dimensional echocardiography before and after the intervention. After the training period, insulin-stimulated myocardial fractional [F-18]FDG uptake and glucose uptake rates were significantly increased in the anterior, lateral, and septal walls (P <.01) in the trained subjects but remained unchanged in the nontrained subjects. In the trained patients, whole-body insulin-stimulated glucose uptake was enhanced and serum free fatty acid levels were suppressed during hyperinsulinemia compared with the baseline study (P <.05). No changes were observed in the nontrained group. CONCLUSIONS These results indicate that exercise training in patients with dilated cardiomyopathy improves insulin-stimulated myocardial glucose uptake. This improvement in glucose uptake may be indicative of a switch in myocardial preference to a more energy-efficient substrate.
Collapse
Affiliation(s)
- Kira Q Stolen
- Turku PET Centre, University of Turku, Turku, Finland
| | | | | | | | | | | | | |
Collapse
|
35
|
Fenning A, Harrison G, Dwyer D, Rose'Meyer R, Brown L. Cardiac adaptation to endurance exercise in rats. Mol Cell Biochem 2003; 251:51-9. [PMID: 14575304 DOI: 10.1007/978-1-4419-9238-3_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Endurance exercise is widely assumed to improve cardiac function in humans. This project has determined cardiac function following endurance exercise for 6 (n = 30) or 12 (n = 25) weeks in male Wistar rats (8 weeks old). The exercise protocol was 30 min/day at 0.8 km/h for 5 days/week with an endurance test on the 6th day by running at 1.2 km/h until exhaustion. Exercise endurance increased by 318% after 6 weeks and 609% after 12 weeks. Heart weight/kg body weight increased by 10.2% after 6 weeks and 24.1% after 12 weeks. Echocardiography after 12 weeks showed increases in left ventricular internal diameter in diastole (6.39 +/- 0.32 to 7.90 +/- 0.17 mm), systolic volume (49 +/- 7 to 83 +/- 11 miccrol) and cardiac output (75 +/- 3 to 107 +/- 8 ml/min) but not left wall thickness in diastole (1.74 +/- 0.07 to 1.80 +/- 0.06 mm). Isolated Langendorff hearts from trained rats displayed decreased left ventricular myocardial stiffness (22 +/- 1.1 to 19.1 +/- 0.3) and reduced purine efflux during pacing-induced workload increases. 31P-NMR spectroscopy in isolated hearts from trained rats showed decreased PCr and PCr/ATP ratios with increased creatine, AMP and ADP concentrations. Thus, this endurance exercise protocol resulted in physiological hypertrophy while maintaining or improving cardiac function.
Collapse
Affiliation(s)
- Andrew Fenning
- Department of Physiology and Pharmacology, School of Biomedical Sciences, The University of Queensland, Australia
| | | | | | | | | |
Collapse
|
36
|
Mallet RT, Squires JE, Bhatia S, Sun J. Pyruvate restores contractile function and antioxidant defenses of hydrogen peroxide-challenged myocardium. J Mol Cell Cardiol 2002; 34:1173-84. [PMID: 12392891 DOI: 10.1006/jmcc.2002.2050] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE Pyruvate, a natural energy-yielding fuel in myocardium, neutralizes peroxides by a direct decarboxylation reaction, and indirectly augments the glutathione (GSH) antioxidant system by generating NADPH reducing power via citrate formation. The possibility that pyruvate's antioxidant actions could mediate its enhancement of contractile performance in prooxidant-challenged myocardium was investigated in isolated working guinea-pig hearts reversibly injured by hydrogen peroxide. METHODS Hearts were challenged by 10 min perfusion with 100 microM H(2)O(2), followed by 90 min H(2)O(2)-free perfusion. Metabolic and antioxidant treatments (each 5m M) were administered at 30-90 min post-H(2)O(2). Phosphocreatine phosphorylation state, GSH/glutathione disulfide redox potential (GSH/GSSG) and key enzyme activities were measured in snap-frozen myocardium. RESULTS H(2)O(2) exposure depleted myocardial energy and antioxidant reserves and produced marked contractile impairment that persisted throughout the H(2)O(2) washout period. Relative to untreated post-H(2)O(2) myocardium, pyruvate restored contractile performance, increased GSH/GSSG 52% and maintained phosphocreatine phosphorylation state; in contrast, lactate lowered cardiac performance and phosphorylation state. Neither the pharmacological antioxidant N -acetylcysteine (NAC) nor the pyruvate analog alpha-ketobutyrate increased cardiac function; both treatments increased GSH/GSSG but lowered phosphocreatine potential. H(2)O(2) partially inactivated aconitase, creatine kinase and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), but all three enzymes spontaneously recovered during H(2)O(2) washout. Pyruvate did not further activate these enzymes and unexpectedly inhibited GAPDH by 60-70%. CONCLUSION Pyruvate promoted robust contractile recovery of H(2)O(2)-challenged myocardium by the combination of citrate-mediated antioxidant mechanisms and maintenance of myocardial energy reserves.
Collapse
Affiliation(s)
- Robert T Mallet
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, Texas 76107-2699, USA.
| | | | | | | |
Collapse
|