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Zheng Y, Xu Y, Ji L, San W, Shen D, Zhou Q, Meng G, Shi J, Chen Y. Roles of distinct nuclear receptors in diabetic cardiomyopathy. Front Pharmacol 2024; 15:1423124. [PMID: 39114353 PMCID: PMC11303215 DOI: 10.3389/fphar.2024.1423124] [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: 04/25/2024] [Accepted: 06/21/2024] [Indexed: 08/10/2024] Open
Abstract
Diabetes mellitus induces a pathophysiological disorder known as diabetic cardiomyopathy and may eventually cause heart failure. Diabetic cardiomyopathy is manifested with systolic and diastolic contractile dysfunction along with alterations in unique cardiomyocyte proteins and diminished cardiomyocyte contraction. Multiple mechanisms contribute to the pathology of diabetic cardiomyopathy, mainly including abnormal insulin metabolism, hyperglycemia, glycotoxicity, cardiac lipotoxicity, endoplasmic reticulum stress, oxidative stress, mitochondrial dysfunction, calcium treatment damage, programmed myocardial cell death, improper Renin-Angiotensin-Aldosterone System activation, maladaptive immune modulation, coronary artery endothelial dysfunction, exocrine dysfunction, etc. There is an urgent need to investigate the exact pathogenesis of diabetic cardiomyopathy and improve the diagnosis and treatment of this disease. The nuclear receptor superfamily comprises a group of transcription factors, such as liver X receptor, retinoid X receptor, retinoic acid-related orphan receptor-α, retinoid receptor, vitamin D receptor, mineralocorticoid receptor, estrogen-related receptor, peroxisome proliferatoractivated receptor, nuclear receptor subfamily 4 group A 1(NR4A1), etc. Various studies have reported that nuclear receptors play a crucial role in cardiovascular diseases. A recently conducted work highlighted the function of the nuclear receptor superfamily in the realm of metabolic diseases and their associated complications. This review summarized the available information on several important nuclear receptors in the pathophysiology of diabetic cardiomyopathy and discussed future perspectives on the application of nuclear receptors as targets for diabetic cardiomyopathy treatment.
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Affiliation(s)
- Yangyang Zheng
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Yongji Xu
- School of Medicine, Nantong University, Nantong, China
| | - Li Ji
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Wenqing San
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Danning Shen
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Qianyou Zhou
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Guoliang Meng
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| | - Jiahai Shi
- Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Yun Chen
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
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Song MW, Cui W, Lee CG, Cui R, Son YH, Kim YH, Kim Y, Kim HJ, Choi SE, Kang Y, Kim TH, Jeon JY, Lee KW. Protective effect of empagliflozin against palmitate-induced lipotoxicity through AMPK in H9c2 cells. Front Pharmacol 2023; 14:1228646. [PMID: 38116084 PMCID: PMC10728651 DOI: 10.3389/fphar.2023.1228646] [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: 05/25/2023] [Accepted: 11/23/2023] [Indexed: 12/21/2023] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors have recently emerged as novel cardioprotective agents. However, their direct impact on cardiomyocyte injury is yet to be studied. In this work, we investigate the underlying molecular mechanisms of empagliflozin (EMPA), an SGLT2 inhibitor, in mitigating palmitate (PA)-induced cardiomyocyte injury in H9c2 cells. We found that EMPA significantly attenuated PA-induced impairments in insulin sensitivity, ER stress, inflammatory cytokine gene expression, and cellular apoptosis. Additionally, EMPA elevated AMP levels, activated the AMPK pathway, and increased carnitine palmitoyl transferase1 (CPT1) gene expression, which collectively enhanced fatty acid oxidation and reduced stress signals. This study reveals a novel mechanism of EMPA's protective effects against PA-induced cardiomyocyte injury, providing new therapeutic insights into EMPA as a cardioprotective agent.
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Affiliation(s)
- Min-Woo Song
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Wenhao Cui
- Department of Hematology, Yanbian University Hospital, Yanji, Jilin, China
| | - Chang-Gun Lee
- Department of Biomedical Laboratory Science, College of Software and Digital Healthcare Convergence, Yonsei University MIRAE Campus, Wonju, Republic of Korea
| | - Rihua Cui
- Department of Hematology, Yanbian University Hospital, Yanji, Jilin, China
| | - Young Ho Son
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Young Ha Kim
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Yujin Kim
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Hae Jin Kim
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Sung-E. Choi
- Department of Physiology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Yup Kang
- Department of Physiology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Tae Ho Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul Medical Center, Seoul, Republic of Korea
| | - Ja Young Jeon
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Kwan-Woo Lee
- Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea
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Impaired regulation of heart rate and sinoatrial node function by the parasympathetic nervous system in type 2 diabetic mice. Sci Rep 2021; 11:12465. [PMID: 34127743 PMCID: PMC8203800 DOI: 10.1038/s41598-021-91937-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/31/2021] [Indexed: 01/01/2023] Open
Abstract
Heart rate (HR) and sinoatrial node (SAN) function are modulated by the autonomic nervous system. HR regulation by the parasympathetic nervous system (PNS) is impaired in diabetes mellitus (DM), which is denoted cardiovascular autonomic neuropathy. Whether blunted PNS effects on HR in type 2 DM are related to impaired responsiveness of the SAN to PNS agonists is unknown. This was investigated in type 2 diabetic db/db mice in vivo and in isolated SAN myocytes. The PNS agonist carbachol (CCh) had a smaller inhibitory effect on HR, while HR recovery time after CCh removal was accelerated in db/db mice. In isolated SAN myocytes CCh reduced spontaneous action potential firing frequency but this effect was reduced in db/db mice due to blunted effects on diastolic depolarization slope and maximum diastolic potential. Impaired effects of CCh occurred due to enhanced desensitization of the acetylcholine-activated K+ current (IKACh) and faster IKACh deactivation. IKACh alterations were reversed by inhibition of regulator of G-protein signaling 4 (RGS4) and by the phospholipid PIP3. SAN expression of RGS4 was increased in db/db mice. Impaired PNS regulation of HR in db/db mice occurs due to reduced responsiveness of SAN myocytes to PNS agonists in association with enhanced RGS4 activity.
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Poetsch MS, Strano A, Guan K. Role of Leptin in Cardiovascular Diseases. Front Endocrinol (Lausanne) 2020; 11:354. [PMID: 32655492 PMCID: PMC7325922 DOI: 10.3389/fendo.2020.00354] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/06/2020] [Indexed: 01/01/2023] Open
Abstract
The adipocyte-derived adipokine leptin exerts pleiotropic effects, which are essential for the regulation of energy balance and cell metabolism, for controlling inflammatory and immune responses, and for the maintenance of homeostasis of the cardiovascular system. Leptin resistance in obese or type 2 diabetes mellitus (T2DM) patients is defined as a decrease in tissue response to leptin. In the cardiovascular system, leptin resistance exhibits the adverse effect on the heart's response to stress conditions and promoting cardiac remodeling due to impaired cardiac metabolism, increased fibrosis, vascular dysfunction, and enhanced inflammation. Leptin resistance or leptin signaling deficiency results in the risk increase of cardiac dysfunction and heart failure, which is a leading cause of obesity- and T2DM-related morbidity and mortality. Animal studies using leptin- and leptin receptor- (Lepr) deficient rodents have provided many useful insights into the underlying molecular and pathophysiological mechanisms of obese- and T2DM-associated metabolic and cardiovascular diseases. However, none of the animal models used so far can fully recapitulate the phenotypes of patients with obese or T2DM. Therefore, the role of leptin in the human cardiovascular system, and whether leptin affects cardiac function directly or acts through a leptin-regulated neurohumoral pathway, remain elusive. As the prevalence of obesity and diabetes is continuously increasing, strategies are needed to develop and apply human cell-based models to better understand the precise role of leptin directly in different cardiac cell types and to overcome the existing translational barriers. The purpose of this review is to discuss the mechanisms associated with leptin signaling deficiency or leptin resistance in the development of metabolic and cardiovascular diseases. We analyzed and comprehensively addressed substantial findings in pathophysiological mechanisms in commonly used leptin- or Lepr-deficient rodent models and highlighted the differences between rodents and humans. This may open up new strategies to develop directly and reliably applicable models, which resemble the human pathophysiology in order to advance health care management of obesity- and T2DM-related cardiovascular complications.
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Contribution of Impaired Insulin Signaling to the Pathogenesis of Diabetic Cardiomyopathy. Int J Mol Sci 2019; 20:ijms20112833. [PMID: 31212580 PMCID: PMC6600234 DOI: 10.3390/ijms20112833] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/19/2022] Open
Abstract
Diabetic cardiomyopathy (DCM) has emerged as a relevant cause of heart failure among the diabetic population. Defined as a cardiac dysfunction that develops in diabetic patients independently of other major cardiovascular risks factors, such as high blood pressure and coronary artery disease, the underlying cause of DCMremains to be unveiled. Several pathogenic factors, including glucose and lipid toxicity, mitochondrial dysfunction, increased oxidative stress, sustained activation of the renin-angiotensin system (RAS) or altered calcium homeostasis, have been shown to contribute to the structural and functional alterations that characterize diabetic hearts. However, all these pathogenic mechanisms appear to stem from the metabolic inflexibility imposed by insulin resistance or lack of insulin signaling. This results in absolute reliance on fatty acids for the synthesis of ATP and impairment of glucose oxidation. Glucose is then rerouted to other metabolic pathways, with harmful effects on cardiomyocyte function. Here, we discuss the role that impaired cardiac insulin signaling in diabetic or insulin-resistant individuals plays in the onset and progression of DCM.
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Abstract
Inflammatory processes underlie many diseases associated with injury of the heart muscle, including conditions without an obvious inflammatory pathogenic component such as hypertensive and diabetic cardiomyopathy. Persistence of cardiac inflammation can cause irreversible structural and functional deficits. Some are induced by direct damage of the heart muscle by cellular and soluble mediators but also by metabolic adaptations sustained by the inflammatory microenvironment. It is well established that both cardiomyocytes and immune cells undergo metabolic reprogramming in the site of inflammation, which allow them to deal with decreased availability of nutrients and oxygen. However, like in cancer, competition for nutrients and increased production of signalling metabolites such as lactate initiate a metabolic cross-talk between immune cells and cardiomyocytes which, we propose, might tip the balance between resolution of the inflammation versus adverse cardiac remodeling. Here we review our current understanding of the metabolic reprogramming of both heart tissue and immune cells during inflammation, and we discuss potential key mechanisms by which these metabolic responses intersect and influence each other and ultimately define the prognosis of the inflammatory process in the heart.
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Affiliation(s)
- Federica M Marelli-Berg
- William Harvey Research Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom.,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
| | - Dunja Aksentijevic
- School of Biological and Chemical Sciences, Queen Mary University of London, G.E. Fogg Building, Mile End Road, London E1 4NS, United Kingdom.,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
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Oshima H, Miki T, Kuno A, Mizuno M, Sato T, Tanno M, Yano T, Nakata K, Kimura Y, Abe K, Ohwada W, Miura T. Empagliflozin, an SGLT2 Inhibitor, Reduced the Mortality Rate after Acute Myocardial Infarction with Modification of Cardiac Metabolomes and Antioxidants in Diabetic Rats. J Pharmacol Exp Ther 2018; 368:524-534. [DOI: 10.1124/jpet.118.253666] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/10/2018] [Indexed: 12/31/2022] Open
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Molecular mechanisms of cardiac pathology in diabetes - Experimental insights. Biochim Biophys Acta Mol Basis Dis 2017; 1864:1949-1959. [PMID: 29109032 DOI: 10.1016/j.bbadis.2017.10.035] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/09/2017] [Accepted: 10/27/2017] [Indexed: 12/11/2022]
Abstract
Diabetic cardiomyopathy is a distinct pathology independent of co-morbidities such as coronary artery disease and hypertension. Diminished glucose uptake due to impaired insulin signaling and decreased expression of glucose transporters is associated with a shift towards increased reliance on fatty acid oxidation and reduced cardiac efficiency in diabetic hearts. The cardiac metabolic profile in diabetes is influenced by disturbances in circulating glucose, insulin and fatty acids, and alterations in cardiomyocyte signaling. In this review, we focus on recent preclinical advances in understanding the molecular mechanisms of diabetic cardiomyopathy. Genetic manipulation of cardiomyocyte insulin signaling intermediates has demonstrated that partial cardiac functional rescue can be achieved by upregulation of the insulin signaling pathway in diabetic hearts. Inconsistent findings have been reported relating to the role of cardiac AMPK and β-adrenergic signaling in diabetes, and systemic administration of agents targeting these pathways appear to elicit some cardiac benefit, but whether these effects are related to direct cardiac actions is uncertain. Overload of cardiomyocyte fuel storage is evident in the diabetic heart, with accumulation of glycogen and lipid droplets. Cardiac metabolic dysregulation in diabetes has been linked with oxidative stress and autophagy disturbance, which may lead to cell death induction, fibrotic 'backfill' and cardiac dysfunction. This review examines the weight of evidence relating to the molecular mechanisms of diabetic cardiomyopathy, with a particular focus on metabolic and signaling pathways. Areas of uncertainty in the field are highlighted and important knowledge gaps for further investigation are identified. This article is part of a Special issue entitled Cardiac adaptations to obesity, diabetes and insulin resistance, edited by Professors Jan F.C. Glatz, Jason R.B. Dyck and Christine Des Rosiers.
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Chong CR, Clarke K, Levelt E. Metabolic Remodeling in Diabetic Cardiomyopathy. Cardiovasc Res 2017; 113:422-430. [PMID: 28177068 PMCID: PMC5412022 DOI: 10.1093/cvr/cvx018] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/02/2017] [Indexed: 02/07/2023] Open
Abstract
Diabetes is a risk factor for heart failure and cardiovascular mortality with specific changes to myocardial metabolism, energetics, structure, and function. The gradual impairment of insulin production and signalling in diabetes is associated with elevated plasma fatty acids and increased myocardial free fatty acid uptake and activation of the transcription factor PPARα. The increased free fatty acid uptake results in accumulation of toxic metabolites, such as ceramide and diacylglycerol, activation of protein kinase C, and elevation of uncoupling protein-3. Insulin signalling and glucose uptake/oxidation become further impaired, and mitochondrial function and ATP production become compromised. Increased oxidative stress also impairs mitochondrial function and disrupts metabolic pathways. The diabetic heart relies on free fatty acids (FFA) as the major substrate for oxidative phosphorylation and is unable to increase glucose oxidation during ischaemia or hypoxia, thereby increasing myocardial injury, especially in ageing female diabetic animals. Pharmacological activation of PPARγ in adipose tissue may lower plasma FFA and improve recovery from myocardial ischaemic injury in diabetes. Not only is the diabetic heart energetically-impaired, it also has early diastolic dysfunction and concentric remodelling. The contractile function of the diabetic myocardium negatively correlates with epicardial adipose tissue, which secretes proinflammatory cytokines, resulting in interstitial fibrosis. Novel pharmacological strategies targeting oxidative stress seem promising in preventing progression of diabetic cardiomyopathy, although clinical evidence is lacking. Metabolic agents that lower plasma FFA or glucose, including PPARγ agonism and SGLT2 inhibition, may therefore be promising options.
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Affiliation(s)
- Cher-Rin Chong
- 1 Department of Physiology, Anatomy and Genetics, University of Oxford
| | - Kieran Clarke
- 1 Department of Physiology, Anatomy and Genetics, University of Oxford
| | - Eylem Levelt
- 2 Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital
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The role of CD36 in the regulation of myocardial lipid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1450-60. [DOI: 10.1016/j.bbalip.2016.03.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/12/2016] [Accepted: 03/14/2016] [Indexed: 12/29/2022]
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Lasheras J, Vilà M, Zamora M, Riu E, Pardo R, Poncelas M, Cases I, Ruiz-Meana M, Hernández C, Feliu JE, Simó R, García-Dorado D, Villena JA. Gene expression profiling in hearts of diabetic mice uncovers a potential role of estrogen-related receptor γ in diabetic cardiomyopathy. Mol Cell Endocrinol 2016; 430:77-88. [PMID: 27062900 DOI: 10.1016/j.mce.2016.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 12/29/2022]
Abstract
Diabetic cardiomyopathy is characterized by an abnormal oxidative metabolism, but the underlying mechanisms remain to be defined. To uncover potential mechanisms involved in the pathophysiology of diabetic cardiomyopathy, we performed a gene expression profiling study in hearts of diabetic db/db mice. Diabetic hearts showed a gene expression pattern characterized by the up-regulation of genes involved in lipid oxidation, together with an abnormal expression of genes related to the cardiac contractile function. A screening for potential regulators of the genes differentially expressed in diabetic mice found that estrogen-related receptor γ (ERRγ) was increased in heart of db/db mice. Overexpression of ERRγ in cultured cardiomyocytes was sufficient to promote the expression of genes involved in lipid oxidation, increase palmitate oxidation and induce cardiomyocyte hypertrophy. Our findings strongly support a role for ERRγ in the metabolic alterations that underlie the development of diabetic cardiomyopathy.
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Affiliation(s)
- Jaime Lasheras
- Laboratory of Metabolism and Obesity, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Maria Vilà
- Laboratory of Metabolism and Obesity, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Mònica Zamora
- Cell Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain; CIBER on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain
| | - Efrén Riu
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - Rosario Pardo
- Laboratory of Metabolism and Obesity, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marcos Poncelas
- Laboratory of Experimental Cardiology, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ildefonso Cases
- Institute of Predictive and Personalized Medicine of Cancer (IMPPC), Barcelona, Spain
| | - Marisol Ruiz-Meana
- Laboratory of Experimental Cardiology, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Cristina Hernández
- CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain; Group of Diabetes and Metabolism, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Juan E Feliu
- Laboratory of Metabolism and Obesity, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rafael Simó
- CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain; Group of Diabetes and Metabolism, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David García-Dorado
- Laboratory of Experimental Cardiology, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Josep A Villena
- Laboratory of Metabolism and Obesity, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Barcelona, Spain; CIBER on Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain.
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Liu F, Song R, Feng Y, Guo J, Chen Y, Zhang Y, Chen T, Wang Y, Huang Y, Li CY, Cao C, Zhang Y, Hu X, Xiao RP. Upregulation of MG53 Induces Diabetic Cardiomyopathy Through Transcriptional Activation of Peroxisome Proliferation-Activated Receptor α. Circulation 2015; 131:795-804. [DOI: 10.1161/circulationaha.114.012285] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Diabetic cardiomyopathy, which contributes to >50% diabetic death, is featured by myocardial lipid accumulation, hypertrophy, fibrosis, and cardiac dysfunction. The mechanism underlying diabetic cardiomyopathy is poorly understood. Recent studies have shown that a striated muscle-specific E3 ligase Mitsugumin 53 (MG53, or TRIM72) constitutes a primary causal factor of systemic insulin resistance and metabolic disorders. Although it is most abundantly expressed in myocardium, the biological and pathological roles of MG53 in triggering cardiac metabolic disorders remain elusive.
Methods and Results—
Here we show that cardiac-specific transgenic expression of MG53 induces diabetic cardiomyopathy in mice. Specifically, MG53 transgenic mouse develops severe diabetic cardiomyopathy at 20 weeks of age, as manifested by insulin resistance, compromised glucose uptake, increased lipid accumulation, myocardial hypertrophy, fibrosis, and cardiac dysfunction. Overexpression of MG53 leads to insulin resistant via destabilizing insulin receptor and insulin receptor substrate 1. More importantly, we identified a novel role of MG53 in transcriptional upregulation of peroxisome proliferation-activated receptor alpha and its target genes, resulting in lipid accumulation and lipid toxicity, thereby contributing to diabetic cardiomyopathy.
Conclusions—
Our results suggest that overexpression of myocardial MG53 is sufficient to induce diabetic cardiomyopathy via dual mechanisms involving upregulation of peroxisome proliferation-activated receptor alpha and impairment of insulin signaling. These findings not only reveal a novel function of MG53 in regulating cardiac peroxisome proliferation-activated receptor alpha gene expression and lipid metabolism, but also underscore MG53 as an important therapeutic target for diabetes mellitus and associated cardiomyopathy.
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Affiliation(s)
- Fenghua Liu
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Ruisheng Song
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yuanqing Feng
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Jiaojiao Guo
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yanmin Chen
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yong Zhang
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Tao Chen
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yanru Wang
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yanyi Huang
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Chuan-Yun Li
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Chunmei Cao
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Yan Zhang
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Xinli Hu
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
| | - Rui-ping Xiao
- From Institute of Molecular Medicine (F.L., R.S., Y.F., J.G., Y.Z., Y.W., C.L., C.C., Y.Z., X.H., R.X.), State Key Laboratory of Biomembrane and Membrane Biotechnology (F.L., R.S., Y.F., J.G., Y.C., Y.Z., Y.W., C.C., Y.Z., X.H., R.X.), Biodynamic Optical Imaging Center (T.C., Y.H.), Center for Life Sciences (Y.C., C.L., R.X.), and Beijing City Key Laboratory of Cardiometabolic Molecular Medicine (R.X.), Peking University, Beijing, China
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Fuentes-Antrás J, Picatoste B, Ramírez E, Egido J, Tuñón J, Lorenzo Ó. Targeting metabolic disturbance in the diabetic heart. Cardiovasc Diabetol 2015; 14:17. [PMID: 25856422 PMCID: PMC4328972 DOI: 10.1186/s12933-015-0173-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/02/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetic cardiomyopathy is defined as ventricular dysfunction initiated by alterations in cardiac energy substrates in the absence of coronary artery disease and hypertension. In addition to the demonstrated burden of cardiovascular events associated with diabetes, diabetic cardiomyopathy partly explains why diabetic patients are subject to a greater risk of heart failure and a worse outcome after myocardial ischemia. The raising prevalence and accumulating costs of cardiovascular disease in diabetic patients underscore the deficiencies of tertiary prevention and call for a shift in medical treatment. It is becoming increasingly clearer that the effective prevention and treatment of diabetic cardiomyopathy require measures to regulate the metabolic derangement occurring in the heart rather than merely restoring suitable systemic parameters. Recent research has provided deeper insight into the metabolic etiology of diabetic cardiomyopathy and numerous heart-specific targets that may substitute or reinforce current strategies. From both experimental and translational perspectives, in this review we first discuss the progress made with conventional therapies, and then focus on the need for prospective metabolic targets that may avert myocardial vulnerability and functional decline in next-generation diabetic care.
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Affiliation(s)
- Jesús Fuentes-Antrás
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
| | - Belén Picatoste
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
- />Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) network, Madrid, Spain
| | - Elisa Ramírez
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
- />Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) network, Madrid, Spain
| | - Jesús Egido
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
- />Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) network, Madrid, Spain
| | - José Tuñón
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
| | - Óscar Lorenzo
- />Vascular, Renal and Diabetes Laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av. Reyes Católicos 2, Madrid, 28040 Spain
- />Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) network, Madrid, Spain
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14
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Li RJ, Yang J, Yang Y, Ma N, Jiang B, Sun QW, Li YJ. Speckle tracking echocardiography in the diagnosis of early left ventricular systolic dysfunction in type II diabetic mice. BMC Cardiovasc Disord 2014; 14:141. [PMID: 25292177 PMCID: PMC4197287 DOI: 10.1186/1471-2261-14-141] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 10/03/2014] [Indexed: 12/05/2022] Open
Abstract
Background The leptin receptor-deficient db/db mouse is a well-established type II diabetes animal model used to investigate diabetic cardiomyopathy. Previous reports have documented diabetic cardiomyopathy is accompanied by cardiac structural and functional abnormalities. To better elucidate early or subtle changes in cardiac performance in db/db mice, we used speckle tracking echocardiography to assess systolic myocardial strain in vivo with diabetic db/db mice in order to study early changes of left ventricle contractile function in type II diabetes model. Methods Male diabetic db/db mice and age-matched control mice from C57BL/6J strain at 8,12 and 16 weeks of age were subjected to echocardiography. At the midpapillary level in the parasternal left ventricular short-axis view, end diastolic and systolic left ventricular diameter, interventricular septal thickness and posterior wall thicknesses, ejection fraction, fractional shortening were determined by M-mode echocardiography. Using speckle-tracking based strain analysis of two-dimensional echocardiographic images acquired from the parasternal short-axis views at the mid-papillary level, systolic global radial and circumferential strain values were analyzed. Results There was no significant difference in interventricular septal thickness, posterior wall thicknesses, end diastolic and systolic left ventricular diameter, ejection fraction and fractional shortening between db/db and age-matched control mice at 8,12 or 16 weeks of age (P > 0.05). At 8 and 12 weeks of age, there was no significant difference in left ventricular radial strain and circumferential strain between db/db mice and age-matched controls (P > 0.05). But at 16 weeks of age, the left ventricular radial strain and circumferential strain in db/db mice were lower than in control mice (P < 0.01). Conclusion The present study shows that speckle tracking echocardiography can be used to evaluate cardiac functional alterations in mouse models of cardiovascular disease. Radial and circumferential strain are more sensitive and can be used for detection of early left ventricular contractile dysfunction in db/db type II diabetic mice.
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Affiliation(s)
| | | | - Ya Yang
- Department of Echocardiography, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
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15
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Soltysinska E, Speerschneider T, Winther SV, Thomsen MB. Sinoatrial node dysfunction induces cardiac arrhythmias in diabetic mice. Cardiovasc Diabetol 2014; 13:122. [PMID: 25113792 PMCID: PMC4149194 DOI: 10.1186/s12933-014-0122-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/03/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study was to probe cardiac complications, including heart-rate control, in a mouse model of type-2 diabetes. Heart-rate development in diabetic patients is not straight forward: In general, patients with diabetes have faster heart rates compared to non-diabetic individuals, yet diabetic patients are frequently found among patients treated for slow heart rates. Hence, we hypothesized that sinoatrial node (SAN) dysfunction could contribute to our understanding of the mechanism behind this conundrum and the consequences thereof. METHODS Cardiac hemodynamic and electrophysiological characteristics were investigated in diabetic db/db and control db/+ mice. RESULTS We found improved contractile function and impaired filling dynamics of the heart in db/db mice, relative to db/+ controls. Electrophysiologically, we observed comparable heart rates in the two mouse groups, but SAN recovery time was prolonged in diabetic mice. Adrenoreceptor stimulation increased heart rate in all mice and elicited cardiac arrhythmias in db/db mice only. The arrhythmias emanated from the SAN and were characterized by large RR fluctuations. Moreover, nerve density was reduced in the SAN region. CONCLUSIONS Enhanced systolic function and reduced diastolic function indicates early ventricular remodeling in obese and diabetic mice. They have SAN dysfunction, and adrenoreceptor stimulation triggers cardiac arrhythmia originating in the SAN. Thus, dysfunction of the intrinsic cardiac pacemaker and remodeling of the autonomic nervous system may conspire to increase cardiac mortality in diabetic patients.
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16
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Lehtoranta L, Vuolteenaho O, Laine VJ, Koskinen A, Soukka H, Kytö V, Määttä J, Haapsamo M, Ekholm E, Räsänen J. Maternal hyperglycemia leads to fetal cardiac hyperplasia and dysfunction in a rat model. Am J Physiol Endocrinol Metab 2013; 305:E611-9. [PMID: 23839525 DOI: 10.1152/ajpendo.00043.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Accelerated fetal myocardial growth with altered cardiac function is a well-documented complication of human diabetic pregnancy, but its pathophysiology is still largely unknown. Our aim was to explore the mechanisms of fetal cardiac remodeling and cardiovascular hemodynamics in a rat model of maternal pregestational streptozotocin-induced hyperglycemia. The hyperglycemic group comprised 107 fetuses (10 dams) and the control group 219 fetuses (20 dams). Fetal cardiac function was assessed serially by Doppler ultrasonography. Fetal cardiac to thoracic area ratio, newborn heart weight, myocardial cell proliferative and apoptotic activities, and cardiac gene expression patterns were determined. Maternal hyperglycemia was associated with increased cardiac size, proliferative, apoptotic and mitotic activities, upregulation of genes encoding A- and B-type natriuretic peptides, myosin heavy chain types 2 and 3, uncoupling proteins 2 and 3, and the angiogenetic tumor necrosis factor receptor superfamily member 12A. The genes encoding Kv channel-interacting protein 2, a regulator of electrical cardiac phenotype, and the insulin-regulated glucose transporter 4 were downregulated. The heart rate was lower in fetuses of hyperglycemic dams. At 13-14 gestational days, 98% of fetuses of hyperglycemic dams had holosystolic atrioventricular valve regurgitation and decreased outflow mean velocity, indicating diminished cardiac output. Maternal hyperglycemia may lead to accelerated fetal myocardial growth by cardiomyocyte hyperplasia. In fetuses of hyperglycemic dams, expression of key genes that control and regulate cardiomyocyte electrophysiological properties, contractility, and metabolism are altered and may lead to major functional and clinical implications on the fetal heart.
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Affiliation(s)
- Lara Lehtoranta
- Department of Obstetrics and Gynecology, University of Turku and Turku University Hospital, Turku, Finland
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17
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Reichelt ME, Mellor KM, Bell JR, Chandramouli C, Headrick JP, Delbridge LMD. Sex, sex steroids, and diabetic cardiomyopathy: making the case for experimental focus. Am J Physiol Heart Circ Physiol 2013; 305:H779-92. [PMID: 23792676 DOI: 10.1152/ajpheart.00141.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
More than three decades ago, the Framingham study revealed that cardiovascular risk is elevated for all diabetics and that this jeopardy is substantially accentuated for women in particular. Numerous studies have subsequently documented worsened cardiac outcomes for women. Given that estrogen and insulin exert major regulatory effects through common intracellular signaling pathways prominent in maintenance of cardiomyocyte function, a sex-hormone:diabetic-disease interaction is plausible. Underlying aspects of female cardiovascular pathophysiology that exaggerate cardiovascular diabetic risk may be identified, including increased vulnerability to coronary microvascular disease, age-dependent impairment of insulin-sensitivity, and differential susceptibility to hyperglycemia. Since Framingham, considerable progress has been made in the development of experimental models of diabetic disease states, including a diversity of genetic rodent models. Ample evidence indicates that animal models of both type 1 and 2 diabetes variably recapitulate aspects of diabetic cardiomyopathy including diastolic and systolic dysfunction, and cardiac structural pathology including fibrosis, loss of compliance, and in some instances ventricular hypertrophy. Perplexingly, little of this work has explored the relevance and mechanisms of sexual dimorphism in diabetic cardiomyopathy. Only a small number of experimental studies have addressed this question, yet the prospects for gaining important mechanistic insights from further experimental enquiry are considerable. The case for experimental interrogation of sex differences, and of sex steroid influences in the aetiology of diabetic cardiomyopathy, is particularly compelling-providing incentive for future investigation with ultimate therapeutic potential.
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Affiliation(s)
- Melissa E Reichelt
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
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Yamaguchi K, Kato M, Ozawa K, Kawai T, Yata T, Aso Y, Ishigai M, Ikeda S. Pharmacokinetic and Pharmacodynamic Modeling for the Effect of Sodium–Glucose Cotransporter Inhibitors on Blood Glucose Level and Renal Glucose Excretion in db/db Mice. J Pharm Sci 2012; 101:4347-56. [DOI: 10.1002/jps.23302] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/24/2012] [Accepted: 08/02/2012] [Indexed: 01/03/2023]
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Abstract
In the setting of obesity and type 2 diabetes mellitus, the ectopic disposition of lipids may be a cause of heart failure. Clinical studies have clearly shown a correlation between the accumulation of triglycerides and heart dysfunction. In this process, it is likely that there are also changes in the contents of sphingolipids. Sphingolipids are important structural and signaling molecules. One specific sphingolipid, ceramide, may cause cardiac dysfunction, whereas another, sphingosine 1-phosphate, is cardioprotective. In this review, the authors focus on the role of sphingolipids in the development and prevention of cardiac failure.
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Affiliation(s)
- Tae-Sik Park
- Department of Life Science, Gachon University, Bokjung-dong, Sujung-gu, Seongnam, Gyunggi-do, South Korea
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20
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König A, Bode C, Bugger H. Diabetes mellitus and myocardial mitochondrial dysfunction: bench to bedside. Heart Fail Clin 2012; 8:551-61. [PMID: 22999239 DOI: 10.1016/j.hfc.2012.06.001] [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: 02/05/2023]
Abstract
In diabetics, the risk for development of heart failure is increased even after adjusting for coronary artery disease and hypertension. Although the cause of this increased heart failure risk is multifactorial, increasing evidence suggests that dysfunction of myocardial mitochondria represents an important pathogenetic factor. To date, no specific therapy exists to treat mitochondrial function in any cardiac disease. This article presents underlying mechanisms of mitochondrial dysfunction in the diabetic heart and discusses potential therapeutic options that may attenuate these mitochondrial derangements.
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Affiliation(s)
- Alexandra König
- Department of Cardiology and Angiology, University Hospital of Freiburg, Hugstetter Strasse 55, Freiburg, Germany
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21
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Tan Y, Muise ES, Dai H, Raubertas R, Wong KK, Thompson GM, Wood HB, Meinke PT, Lum PY, Thompson JR, Berger JP. Novel transcriptome profiling analyses demonstrate that selective peroxisome proliferator-activated receptor γ (PPARγ) modulators display attenuated and selective gene regulatory activity in comparison with PPARγ full agonists. Mol Pharmacol 2012; 82:68-79. [PMID: 22496518 DOI: 10.1124/mol.111.076679] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Selective peroxisome proliferator-activated receptor γ (PPARγ) modulators (SPPARγMs) have been actively pursued as the next generation of insulin-sensitizing antidiabetic drugs, because the currently marketed PPARγ full agonists, pioglitazone and rosiglitazone, have been reported to produce serious adverse effects among patients with type 2 diabetes mellitus. We conducted extensive transcriptome profiling studies to characterize and to contrast the activities of 70 SPPARγMs and seven PPARγ full agonists. In both 3T3-L1 adipocytes and adipose tissue from db/db mice, the SPPARγMs generated attenuated and selective gene-regulatory responses, in comparison with full agonists. More importantly, SPPARγMs regulated the expression of antidiabetic efficacy-associated genes to a greater extent than that of adverse effect-associated genes, whereas PPARγ full agonists regulated both gene sets proportionally. Such SPPARγM selectivity demonstrates that PPARγ ligand regulation of gene expression can be fine-tuned, and not just turned on and off, to achieve precise control of complex cellular and physiological functions. It also provides a potential molecular basis for the superior therapeutic window previously observed with SPPARγMs versus full agonists. On the basis of our profiling results, we introduce two novel, gene expression-based scores, the γ activation index and the selectivity index, to aid in the detection and characterization of novel SPPARγMs. These studies provide new insights into the gene-regulatory activity of SPPARγMs as well as novel quantitative indices to facilitate the identification of PPARγ ligands with robust insulin-sensitizing activity and improved tolerance among patients with type 2 diabetes, compared with presently available PPARγ agonist drugs.
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Affiliation(s)
- Yejun Tan
- Department of Informatics and Analysis, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Belke DD, Severson DL. Diabetes in mice with monogenic obesity: the db/db mouse and its use in the study of cardiac consequences. Methods Mol Biol 2012; 933:47-57. [PMID: 22893400 DOI: 10.1007/978-1-62703-068-7_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The leptin receptor deficient db/db mouse has served as a rodent model for obesity and type 2 diabetes for more than 40 years. Diabetic features in db/db mice follow an age-dependent progression, with early insulin resistance followed by an insulin secretory defect resulting in profound hyperglycemia. Diabetic db/db mice have been utilized to assess the cardiac consequences of diabetes, specifically evidence for a distinct diabetic cardiomyopathy. The db/db model is characterized by a contractile function deficit in the heart which becomes manifest 8-10 weeks after birth. Metabolic changes include an increased reliance on fatty acids and a decreased reliance on glucose as a fuel source for oxidative metabolism within the heart. As a mouse model for type 2 diabetes, both drug treatment and transgenic manipulation have proven beneficial towards improving metabolism and contractile function. The db/db mouse model has provided a useful resource to understand and treat the type 2 diabetic condition.
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Increased expression of the tail-anchored membrane protein SLMAP in adipose tissue from type 2 Tally Ho diabetic mice. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:421982. [PMID: 21785580 PMCID: PMC3137969 DOI: 10.1155/2011/421982] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 05/05/2011] [Indexed: 11/17/2022]
Abstract
The tail-anchored membrane protein, sarcolemmal membrane associated protein (SLMAP) is encoded to a single gene that maps to the chromosome 3p14 region and has also been reported in certain diabetic populations. Our previous studies with db/db mice shown that a deregulation of SLMAP expression plays an important role in type 2 diabetes. Male Tally Ho mice were bred to present with either normoglycemia (NG) or hyperglycemia (HG). Abdominal adipose tissue from male Tally Ho mice of the HG group was found to have a significantly lower expression of the membrane associated glucose transporter-4 (GLUT-4) and higher expression of SLMAP compared to tissue from NG mice. There were 3 isoforms expressed in the abdominal adipose tissue, but only 45 kDa isoform of SLMAP was associated with the GLUT-4 revealed by immunoprecipitation data. Knock down studies using SLMAP siRNA with adipocytes resulted in a significant reduction in SLMAP and a decrease in glucose uptake. Thus, SLMAP may be an important regulator of glucose uptake or involved in GLUT-4 fusion/translocation into the plasma membrane of mouse abdominal adipose tissue and changes in SLMAP expression are linked to hyperglycemia and diabetes.
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Campreciós G, Lorita J, Pardina E, Peinado-Onsurbe J, Soley M, Ramírez I. Expression, localization, and regulation of the neuregulin receptor ErbB3 in mouse heart. J Cell Physiol 2011; 226:450-5. [PMID: 20672328 DOI: 10.1002/jcp.22354] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Neuregulins (NRG) belong to the EGF family of growth factors, which are ligands of the ErbB receptors. Their expression in the adult heart is essential, especially when the heart is submitted to cardiotoxic stress such as that produced by anthracyclines. It is considered that ErbB4 is the only NRG receptor expressed by the adult heart. Upon binding, ErbB4 may dimerize with ErbB2 to generate signals inside cells. However, here we show the presence of ErbB3 in the mouse heart from birth to adulthood by Western blotting and real-time RT-PCR. The expression level of ErbB3 mRNA was lower than that of ErbB2 or ErbB4, but was more stable throughout postnatal development. In isolated heart myocytes, ErbB3 localized to the Z-lines similarly to ErbB1. Perfusion of isolated hearts with NRG-1β induced phosphorylation of ErbB3, as well as ErbB2 and ErbB4. In adult mice, both ErbB2 and ErbB3, but not ErbB1 or ErbB4, were rapidly down-regulated upon the induction of heart hypertrophy. In conclusion, our results demonstrate that ErbB3, in addition to ErbB4, is a receptor for neuregulin-1β in the adult mouse heart.
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Affiliation(s)
- Genís Campreciós
- Faculty of Biology, Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Catalonia, Spain
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25
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Baranowski M, Górski J. Heart sphingolipids in health and disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 721:41-56. [PMID: 21910081 DOI: 10.1007/978-1-4614-0650-1_3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In recent years, the role of sphingolipids in physiology and pathophysiology of the heart attracted much attention. Ceramide was found to be involved in the pathogenesis of cardiac dysfunction in animal models of ischemia/reperfusion injury, Type 2 diabetes and lipotoxic cardiomyopathy. On the other hand, another member of this lipid family, namely sphingosine-1-phosphate, has been shown to possess potent cardioprotective properties. This chapter provides a review of the role of ceramide and other bioactive sphingolipids in physiology and pathophysiology of the heart. We describe the role of PPARs and exercise in regulation of myocardial sphingolipid metabolism. We also summarize the present state of knowledge on the involvement of ceramide and sphingosine-1-phosphate in the development and prevention of ischemia/reperfusion injury of the heart. In the last section of this chapter we discuss the evidence for a role of ceramide in myocardial lipotoxicity.
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Carley AN, Kleinfeld AM. Fatty acid (FFA) transport in cardiomyocytes revealed by imaging unbound FFA is mediated by an FFA pump modulated by the CD36 protein. J Biol Chem 2010; 286:4589-97. [PMID: 21147770 DOI: 10.1074/jbc.m110.182162] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Free fatty acid (FFA) transport across the cardiomyocyte plasma membrane is essential to proper cardiac function, but the role of membrane proteins and FFA metabolism in FFA transport remains unclear. Metabolism is thought to maintain intracellular FFA at low levels, providing the driving force for FFA transport, but intracellular FFA levels have not been measured directly. We report the first measurements of the intracellular unbound FFA concentrations (FFA(i)) in cardiomyocytes. The fluorescent indicator of FFA, ADIFAB (acrylodan-labeled rat intestinal fatty acid-binding protein), was microinjected into isolated cardiomyocytes from wild type (WT) and FAT/CD36 null C57B1/6 mice. Quantitative imaging of ADIFAB fluorescence revealed the time courses of FFA influx and efflux. For WT mice, rate constants for efflux (∼0.02 s(-1)) were twice influx, and steady state FFA(i) were more than 3-fold larger than extracellular unbound FFA (FFA(o)). The concentration gradient and the initial rate of FFA influx saturated with increasing FFA(o). Similar characteristics were observed for oleate, palmitate, and arachidonate. FAT/CD36 null cells revealed similar characteristics, except that efflux was 2-3-fold slower than WT cells. Rate constants determined with intracellular ADIFAB were confirmed by measurements of intracellular pH. FFA uptake by suspensions of cardiomyocytes determined by monitoring FFA(o) using extracellular ADIFAB confirmed the influx rate constants determined from FFA(i) measurements and demonstrated that rates of FFA transport and etomoxir-sensitive metabolism are regulated independently. We conclude that FFA influx in cardiac myocytes is mediated by a membrane pump whose transport rate constants may be modulated by FAT/CD36.
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Affiliation(s)
- Andrew N Carley
- Torrey Pines Institute for Molecular Studies, San Diego, California 92121, USA
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Daniels A, van Bilsen M, Janssen BJA, Brouns AE, Cleutjens JPM, Roemen THM, Schaart G, van der Velden J, van der Vusse GJ, van Nieuwenhoven FA. Impaired cardiac functional reserve in type 2 diabetic db/db mice is associated with metabolic, but not structural, remodelling. Acta Physiol (Oxf) 2010; 200:11-22. [PMID: 20175764 DOI: 10.1111/j.1748-1716.2010.02102.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
AIM To identify the initial alterations in myocardial tissue associated with the early signs of diabetic cardiac haemodynamic dysfunction, we monitored changes in cardiac function, structural remodelling and gene expression in hearts of type 2 diabetic db/db mice. METHODS Cardiac dimensions and function were determined echocardiographically at 8, 12, 16 and 18 weeks of age. Left ventricular pressure characteristics were measured at 18 weeks under baseline conditions and upon dobutamine infusion. RESULTS The db/db mice were severely diabetic already at 8 weeks after birth, showing elevated fasting blood glucose levels and albuminuria. Nevertheless, echocardiography revealed no significant changes in cardiac function up to 18 weeks of age. At 18 weeks of age, left ventricular pressure characteristics were not significantly different at baseline between diabetic and control mice. However, dobutamine stress test revealed significantly attenuated cardiac inotropic and lusitropic responses in db/db mice. Post-mortem cardiac tissue analyses showed minor structural remodelling and no significant changes in gene expression levels of the sarcoplasmic reticulum calcium ATPase (SERCA2a) or beta1-adrenoceptor (beta1-AR). Moreover, the phosphorylation state of known contractile protein targets of protein kinase A (PKA) was not altered, indicating unaffected cardiac beta-adrenergic signalling activity in diabetic animals. By contrast, the substantially increased expression of uncoupling protein-3 (UCP3) and angiopoietin-like-4 (Angptl4), along with decreased phosphorylation of AMP-activated protein kinase (AMPK) in the diabetic heart, is indicative of marked changes in cardiac metabolism. CONCLUSION db/db mice show impaired cardiac functional reserve capacity during maximal beta-adrenergic stimulation which is associated with unfavourable changes in cardiac energy metabolism.
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Affiliation(s)
- A Daniels
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands
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Singh S, Dhingra S, Ramdath DD, Vasdev S, Gill V, Singal PK. Risk Factors Preceding Type 2 Diabetes and Cardiomyopathy. J Cardiovasc Transl Res 2010; 3:580-96. [DOI: 10.1007/s12265-010-9197-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 05/26/2010] [Indexed: 12/20/2022]
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Hinds K, Stachenfeld NS. Greater orthostatic tolerance in young black compared with white women. Hypertension 2010; 56:75-81. [PMID: 20458005 PMCID: PMC2909588 DOI: 10.1161/hypertensionaha.110.150011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 04/19/2010] [Indexed: 11/16/2022]
Abstract
We hypothesized that orthostatic tolerance is higher in young, healthy black compared with white women. To determine orthostatic tolerance, 22 women (11 black and 11 white) underwent graded lower body negative pressure to presyncope. We measured blood pressure, heart rate, and R-R interval (ECG) continuously at baseline and through all of the levels of lower body negative pressure. Blood samples were taken at baseline along with presyncope for the measurement of plasma catecholamine concentrations, serum aldosterone concentration, and plasma renin activity. Cumulative stress index, the sum of the product of time and lower body negative pressure, was the indicator of orthostatic tolerance. Orthostatic tolerance in the black women was greater than in the white women [cumulative stress index: -1003 (375) versus -476 (197); P<0.05]. Although plasma concentrations of norepinephrine increased in both groups at presyncope, the increase was greater in black [Deltaplasma concentrations of norepinephrine: 167 (123)] versus white women [86 (64); P<0.05], as was the increase in PRA [DeltaPRA 2.6 (1.0) versus 0.6 (0.9) ng of angiotensin II x mL(-1) x h(-1); P<0.05, for black and white women, respectively). Although heart rate increased and R-R interval decreased to a greater extent during lower body negative pressure in black women compared with white women (ANOVA: P<0.05), baroreflex function (ie, slope R-R interval versus systolic blood pressure) was unaffected by race. These data indicate that orthostatic tolerance is greater in black compared with white women, which appears to be a function of greater sympathetic nervous system responses to orthostatic challenges.
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Affiliation(s)
- Kumba Hinds
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Public Health, Yale University School of Medicine, New Haven, Conn, USA
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Abstract
There has been growing interest in targeting myocardial substrate metabolism for the therapy of cardiovascular and metabolic diseases. This is largely based on the observation that cardiac metabolism undergoes significant changes during both physiologic and pathologic stresses. In search for an effective therapeutic strategy, recent studies have focused on the functional significance of the substrate switch in the heart during stress conditions, such as cardiac hypertrophy and failure, using both pharmacologic and genetic approaches. The results of these studies indicate that both the capacity and the flexibility of the cardiac metabolic network are essential for normal function; thus, their maintenance should be the primary goal for future metabolic therapy.
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Affiliation(s)
- Stephen C Kolwicz
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
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31
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Brindley DN, Kok BPC, Kienesberger PC, Lehner R, Dyck JRB. Shedding light on the enigma of myocardial lipotoxicity: the involvement of known and putative regulators of fatty acid storage and mobilization. Am J Physiol Endocrinol Metab 2010; 298:E897-908. [PMID: 20103741 DOI: 10.1152/ajpendo.00509.2009] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Excessive fatty acid (FA) uptake by cardiac myocytes is often associated with adverse changes in cardiac function. This is especially evident in diabetic individuals, where increased intramyocardial triacylglycerol (TG) resulting from the exposure to high levels of circulating FA has been proposed to be a major contributor to diabetic cardiomyopathy. At present, our knowledge of how the heart regulates FA storage in TG and the hydrolysis of this TG is limited. This review concentrates on what is known about TG turnover within the heart and how this is likely to be regulated by extrapolating results from other tissues. We also assess the evidence as to whether increased TG accumulation protects against FA-induced lipotoxicity through limiting the accumulations of ceramides and diacylglycerols versus whether it is a maladaptive response that contributes to cardiac dysfunction.
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Affiliation(s)
- David N Brindley
- Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
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Lopaschuk GD, Ussher JR, Folmes CDL, Jaswal JS, Stanley WC. Myocardial fatty acid metabolism in health and disease. Physiol Rev 2010; 90:207-58. [PMID: 20086077 DOI: 10.1152/physrev.00015.2009] [Citation(s) in RCA: 1459] [Impact Index Per Article: 104.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
There is a constant high demand for energy to sustain the continuous contractile activity of the heart, which is met primarily by the beta-oxidation of long-chain fatty acids. The control of fatty acid beta-oxidation is complex and is aimed at ensuring that the supply and oxidation of the fatty acids is sufficient to meet the energy demands of the heart. The metabolism of fatty acids via beta-oxidation is not regulated in isolation; rather, it occurs in response to alterations in contractile work, the presence of competing substrates (i.e., glucose, lactate, ketones, amino acids), changes in hormonal milieu, and limitations in oxygen supply. Alterations in fatty acid metabolism can contribute to cardiac pathology. For instance, the excessive uptake and beta-oxidation of fatty acids in obesity and diabetes can compromise cardiac function. Furthermore, alterations in fatty acid beta-oxidation both during and after ischemia and in the failing heart can also contribute to cardiac pathology. This paper reviews the regulation of myocardial fatty acid beta-oxidation and how alterations in fatty acid beta-oxidation can contribute to heart disease. The implications of inhibiting fatty acid beta-oxidation as a potential novel therapeutic approach for the treatment of various forms of heart disease are also discussed.
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Affiliation(s)
- Gary D Lopaschuk
- Cardiovascular Research Group, Mazankowski Alberta Heart Institute, University of Alberta, Alberta T6G 2S2, Canada.
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Vernochet C, Davis KE, Scherer PE, Farmer SR. Mechanisms regulating repression of haptoglobin production by peroxisome proliferator-activated receptor-gamma ligands in adipocytes. Endocrinology 2010; 151:586-94. [PMID: 19952271 PMCID: PMC2817616 DOI: 10.1210/en.2009-1057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Obesity leads to inflammation of white adipose tissue involving enhanced secretion of cytokines and acute-phase proteins in response in part to the accumulation of excess lipids in adipocytes. Haptoglobin is an acute-phase reactant secreted by white adipose tissue and induced by inflammatory cytokines such as TNFalpha. In this study, we investigated the mechanisms regulating haptoglobin expression in adipocytes. Peroxisome proliferator-activated receptor (PPAR)-gamma agonists such as thiazolidinediones (TZDs) as well as non-TZD ligands can repress in vitro and in vivo haptoglobin expression in adipocytes and also prevent its induction by TNFalpha. This action requires direct involvement of PPAR gamma in regulating haptoglobin gene transcription because mutation of critical amino acids within helix 7 of the ligand-binding domain of PPAR gamma prevents repression of the haptoglobin gene by the synthetic ligands. Chromatin immunoprecipitation analysis shows active binding of PPAR gamma to a distal region of the haptoglobin promoter, which contains putative PPAR gamma binding sites. Additionally, PPAR gamma induces transcription of a luciferase reporter gene when driven by the distal promoter region of the haptoglobin gene, and TZD treatment significantly reduces the extent of this induction. Furthermore, the mutated PPAR gamma is incapable of enhancing luciferase activity in these in vitro reporter gene assays. In contrast to other adipokines repressed by TZDs such as resistin and chemerin, repression of haptoglobin does not require either CCAAT/enhancer-binding protein C/EBP alpha or the corepressors C-terminal binding protein 1 or 2. These data are consistent with a model in which synthetic PPAR gamma ligands selectively activate PPAR gamma bound to the haptoglobin gene promoter to arrest haptoglobin gene transcription.
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Affiliation(s)
- Cecile Vernochet
- Department of Biochemistry, Boston University School of Medicine, 715 Albany Street, Boston, Massachusetts 02118, USA
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Abstract
Diabetic cardiomyopathy increases the risk of heart failure in individuals with diabetes, independently of co-existing coronary artery disease and hypertension. The underlying mechanisms for this cardiac complication are incompletely understood. Research on rodent models of type 1 and type 2 diabetes, and the use of genetic engineering techniques in mice, have greatly advanced our understanding of the molecular mechanisms responsible for human diabetic cardiomyopathy. The adaptation of experimental techniques for the investigation of cardiac physiology in mice now allows comprehensive characterization of these models. The focus of the present review will be to discuss selected rodent models that have proven to be useful in studying the underlying mechanisms of human diabetic cardiomyopathy, and to provide an overview of the characteristics of these models for the growing number of investigators who seek to understand the pathology of diabetes-related heart disease.
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Affiliation(s)
- Heiko Bugger
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
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Vernochet C, Peres SB, Davis KE, McDonald ME, Qiang L, Wang H, Scherer PE, Farmer SR. C/EBPalpha and the corepressors CtBP1 and CtBP2 regulate repression of select visceral white adipose genes during induction of the brown phenotype in white adipocytes by peroxisome proliferator-activated receptor gamma agonists. Mol Cell Biol 2009; 29:4714-28. [PMID: 19564408 PMCID: PMC2725706 DOI: 10.1128/mcb.01899-08] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 02/23/2009] [Accepted: 06/18/2009] [Indexed: 01/02/2023] Open
Abstract
White adipose tissue (WAT) stores energy in the form of triglycerides, whereas brown tissue (BAT) expends energy, primarily by oxidizing lipids. WAT also secretes many cytokines and acute-phase proteins that contribute to insulin resistance in obese subjects. In this study, we have investigated the mechanisms by which activation of peroxisome proliferator-activated receptor gamma (PPARgamma) with synthetic agonists induces a brown phenotype in white adipocytes in vivo and in vitro. We demonstrate that this phenotypic conversion is characterized by repression of a set of white fat genes ("visceral white"), including the resistin, angiotensinogen, and chemerin genes, in addition to induction of brown-specific genes, such as Ucp-1. Importantly, the level of expression of the "visceral white" genes is high in mesenteric and gonadal WAT depots but low in the subcutaneous WAT depot and in BAT. Mutation of critical amino acids within helix 7 of the ligand-binding domain of PPARgamma prevents inhibition of visceral white gene expression by the synthetic agonists and therefore shows a direct role for PPARgamma in the repression process. Inhibition of the white adipocyte genes also depends on the expression of C/EBPalpha and the corepressors, carboxy-terminal binding proteins 1 and 2 (CtBP1/2). The data further show that repression of resistin and angiotensinogen expression involves recruitment of CtBP1/2, directed by C/EBPalpha, to the minimal promoter of the corresponding genes in response to the PPARgamma ligand. Developing strategies to enhance the brown phenotype in white adipocytes while reducing secretion of stress-related cytokines from visceral WAT is a means to combat obesity-associated disorders.
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Affiliation(s)
- Cecile Vernochet
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Lorita J, Camprecios G, Soley M, Ramirez I. ErbB receptors protect the perfused heart against injury induced by epinephrine combined with low-flow ischemia. Growth Factors 2009; 27:203-13. [PMID: 19370475 DOI: 10.1080/08977190902913731] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
ErbB receptor tyrosine kinases are important in maintaining the long-term structural integrity of the heart and in the induction of hypertrophy. In addition, in vivo activation of ErbB1 by epidermal growth factor (EGF) protects the heart against acute stress-induced damage. We examined here whether the ErbB sytem acutely protects the isolated heart in which stress was induced in vitro by ischemia combined with epinephrine infusion (EPI). In perfused mouse hearts, EGF induced Tyr-phosphorylation of ErbB1 but not ErbB2. Neuregulin-1beta (NRG-1beta) induced Tyr-phosphorylation of both ErbB4 and ErbB2. We also found differences in the signaling cascades activated by each growth factor. To stress the perfused mouse heart, we combined EPI with low-flow ischemia. This resulted in (i) loss of left ventricle contraction force ( + dP/dt(max)) and developed pressure (LVDP) after a short period of hypercontractility, (ii) enhanced anaerobic metabolism (lactate production), and (iii) myocyte injury (lactate dehydrogenase (LDH) release). EGF and NRG-1beta had different effects on stressed-heart contractility. EGF reduced to a half the loss of both + dP/dt(max) and LVDP. In contrast, NRG-1beta exacerbated the hypercontractility soon after reperfusion. This is coincident with a transient increase in coronary flow after reperfusion. In spite of these differences in contraction, both EGF and NRG-1beta induced similar early protection as shown by the reduction of LDH release. Our results show that the ErbB system protects the perfused heart against damage induced by acute stress. They reinforce the relevance of ErbB receptors and ligands in cardiac physiology.
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Affiliation(s)
- Jordi Lorita
- Departament de Bioquimica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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37
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Jaswal JS, Ussher JR, Lopaschuk GD. Myocardial fatty acid utilization as a determinant of cardiac efficiency and function. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.18] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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38
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Niu YG, Evans RD. Myocardial metabolism of triacylglycerol-rich lipoproteins in type 2 diabetes. J Physiol 2009; 587:3301-15. [PMID: 19433573 DOI: 10.1113/jphysiol.2009.173542] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cardiac utilisation of very-low-density lipoprotein (VLDL) and chylomicrons (CM) was investigated in the ZDF rat model of type 2 diabetes, in order to define the role of triacylglycerol (TAG) metabolism in the development of contractile dysfunction. Hearts from obese diabetic and lean littermate control rats were perfused with VLDL and CM from diabetic and control rats. Metabolic fate of the lipoprotein TAG and contractile function were examined. Myocardial utilisation of both VLDL- and CM-TAG was increased in the diabetic state. Diabetic hearts oxidised diabetic lipoprotein-TAG to a greater extent than control lipoproteins; glucose oxidation was decreased. There was no difference in lipoprotein-TAG assimilation into diabetic heart lipids; diabetic lipoproteins were, however, a poor substrate for control heart tissue lipid accumulation. Although the proportion of exogenous lipid incorporated into tissue TAG was increased in diabetic hearts perfused with control lipoproteins, this effect was not seen in diabetic hearts perfused with diabetic lipoproteins. Myocardial heparin-releasable lipoprotein lipase (LPL) activity was moderately increased in the diabetic state, and diabetic lipoproteins increased tissue-residual LPL activity. Cardiac hydraulic work was decreased only in diabetic hearts perfused with diabetic CM. Compositional analysis of diabetic variant lipoproteins indicated changes in size and apoprotein content. Alterations in cardiac TAG-rich lipoprotein metabolism in type 2 diabetes are due to changes in both the diabetic myocardium and the diabetic lipoprotein particle; decreased contractile function is not related to cardiac lipid accumulation from TAG-rich lipoproteins but may be associated with changes in TAG-fatty acid oxidation.
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Affiliation(s)
- You-Guo Niu
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
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Fernandes-Santos C, Carneiro RE, de Souza Mendonca L, Aguila MB, Mandarim-de-Lacerda CA. Pan-PPAR agonist beneficial effects in overweight mice fed a high-fat high-sucrose diet. Nutrition 2009; 25:818-27. [PMID: 19268533 DOI: 10.1016/j.nut.2008.12.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 11/25/2008] [Accepted: 12/11/2008] [Indexed: 12/19/2022]
Abstract
OBJECTIVE We analyzed the effect of peroxisome proliferator-activated receptor (PPAR) agonists on adipose tissue morphology, adiponectin expression, and its relation to glucose and insulin levels in C57BL/6 mice fed a high-fat high-sucrose (HFHS) diet. METHODS Male C57BL/6 mice received one of five diets: standard chow, HFHS chow, or HFHS plus rosiglitazone (PPAR-gamma agonist), fenofibrate (PPAR-alpha agonist), or bezafibrate (pan-PPAR agonist). Diets were administered for 11 wk and medications from week 6 to week 11. Glucose intolerance (GI) and insulin resistance were evaluated by oral glucose tolerance testing and homeostasis model assessment for insulin resistance, respectively. Adipocyte diameter was analyzed in epididymal, inguinal, and retroperitoneal fat pads and by adiponectin immunostain. RESULTS Mice fed the HFHS chow had hyperglycemia, GI, insulin resistance, increased fat pad weight, adipocyte hypertrophy, and decreased adiponectin immunostaining. Rosiglitazone improved GI, insulin sensitiveness, and adiponectin immunostaining, but it resulted in body weight gain, hyperphagia, and adipocyte and heart hypertrophy. Fenofibrate improved all parameters except for fasting glucose and GI. Bezafibrate was the most efficient in decreasing body weight and glucose intolerance. CONCLUSION Activation of PPAR-alpha, -delta, and -gamma together is better than the activation of PPAR-alpha or -gamma alone, because bezafibrate showed a wider range of action on metabolic, morphologic, and biometric alterations due to an HFHS diet in mice.
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Puthanveetil P, Wang F, Kewalramani G, Kim MS, Hosseini-Beheshti E, Ng N, Lau W, Pulinilkunnil T, Allard M, Abrahani A, Rodrigues B. Cardiac glycogen accumulation after dexamethasone is regulated by AMPK. Am J Physiol Heart Circ Physiol 2008; 295:H1753-62. [DOI: 10.1152/ajpheart.518.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycogen is an immediate source of glucose for cardiac tissue to maintain its metabolic homeostasis. However, its excess brings about cardiac structural and physiological impairments. Previously, we have demonstrated that in hearts from dexamethasone (Dex)-treated animals, glycogen accumulation was enhanced. We examined the influence of 5′-AMP-activated protein kinase (AMPK) on glucose entry and glycogen synthase as a means of regulating the accumulation of this stored polysaccharide. After Dex, cardiac tissue had a limited contribution toward the development of whole body insulin resistance. Measurement of glucose transporter 4 (GLUT4) at the plasma membrane revealed an excess presence of this transporter protein at this location. Interestingly, this was accompanied by an increase in GLUT4 in the intracellular membrane fraction, an effect that was well correlated with increased GLUT4 mRNA. Both total and phosphorylated AMPK increased after Dex. Immunoprecipitation of Akt substrate of 160 kDa (AS160) followed by Western blot analysis demonstrated no change in Akt phosphorylation at Ser473and Thr308in Dex-treated hearts. However, there was a significant increase in AMPK phosphorylation at Thr172, which correlated well with AS160 phosphorylation. In Dex-treated hearts, there was a considerable reduction in the phosphorylation of glycogen synthase, whereas glycogen synthase kinase-3-β phosphorylation was augmented. Our data suggest that AMPK-mediated glucose entry combined with the activation of glycogen synthase and a reduction in glucose oxidation (Qi et al., Diabetes 53: 1790–1797, 2004) act together to promote glycogen storage. Should these effects persist chronically in the heart, they may explain the increased morbidity and mortality observed with long-term excesses in endogenous or exogenous glucocorticoids.
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Carley AN, Severson DL. What are the biochemical mechanisms responsible for enhanced fatty acid utilization by perfused hearts from type 2 diabetic db/db mice? Cardiovasc Drugs Ther 2008; 22:83-9. [PMID: 18247111 DOI: 10.1007/s10557-008-6088-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 01/18/2008] [Indexed: 01/20/2023]
Abstract
INTRODUCTION It is generally accepted that diabetic hearts have an altered metabolic phenotype, with enhanced fatty acid (FA) utilization. The over-utilization of FA by diabetic hearts can have deleterious functional consequences, contributing to a distinct diabetic cardiomyopathy. The objective of this review will be to examine which biochemical mechanisms are responsible for enhanced FA utilization by diabetic hearts. METHODOLOGY AND RESULTS Studies were performed with db/db mice, a monogenic model of type 2 diabetes with extreme obesity and hyperglycemia. Perfused db/db hearts exhibit enhanced FA oxidation and esterification. Hypothesis 1: Cardiac FA uptake is enhanced in db/db hearts. The plasma membrane content of two FA transporters, fatty acid translocase/CD36 (FAT/CD36) and plasma membrane fatty acid binding protein (FABPpm), was increased in db/db hearts, consistent with hypothesis 1. Hypothesis 2: Cardiac FA oxidation is enhanced in db/db hearts due to mitochondrial alterations. However, the activity of carnitine palmitoyl transferase-1 (CPT-1) and sensitivity to inhibition by malonyl CoA was unchanged in mitochondria from db/db hearts. Furthermore, total malonyl CoA content was increased, not decreased as predicted for elevated FA oxidation. Finally, the content of uncoupling protein-3 was unchanged in db/db heart mitochondria. CONCLUSION Increased plasma membrane content of FA transporters (FAT/CD36 and FABPpm) will increase FA uptake into db/db cardiomyocytes and thus increase FA utilization. On the other hand, mitochondrial mechanisms do not contribute to elevated rates of FA oxidation in db/db hearts.
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Affiliation(s)
- Andrew N Carley
- Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary AB T2N 4N1, Canada
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Wang ZV, Mu J, Schraw TD, Gautron L, Elmquist JK, Zhang BB, Brownlee M, Scherer PE. PANIC-ATTAC: a mouse model for inducible and reversible beta-cell ablation. Diabetes 2008; 57:2137-48. [PMID: 18469203 PMCID: PMC2494693 DOI: 10.2337/db07-1631] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Islet transplantations have been performed clinically, but their practical applications are limited. An extensive effort has been made toward the identification of pancreatic beta-cell stem cells that has yielded many insights to date, yet targeted reconstitution of beta-cell mass remains elusive. Here, we present a mouse model for inducible and reversible ablation of pancreatic beta-cells named the PANIC-ATTAC (pancreatic islet beta-cell apoptosis through targeted activation of caspase 8) mouse. RESEARCH DESIGN AND METHODS We efficiently induce beta-cell death through apoptosis and concomitant hyperglycemia by administration of a chemical dimerizer to the transgenic mice. In contrast to animals administered streptozotocin, the diabetes phenotype and beta-cell loss are fully reversible in the PANIC-ATTAC mice, and we find significant beta-cell recovery with normalization of glucose levels after 2 months. RESULTS The rate of recovery can be enhanced by various pharmacological interventions with agents acting on the glucagon-like peptide 1 axis and agonists of peroxisome proliferator-activated receptor-gamma. During recovery, we find an increased population of GLUT2(+)/insulin(-) cells in the islets of PANIC-ATTAC mice, which may represent a novel pool of potential beta-cell precursors. CONCLUSIONS The PANIC-ATTAC mouse may be used as an animal model of inducible and reversible beta-cell ablation and therefore has applications in many areas of diabetes research that include identification of beta-cell precursors, evaluation of glucotoxicity effects in diabetes, and examination of pharmacological interventions.
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Affiliation(s)
- Zhao V Wang
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
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Wilson KD, Li Z, Wagner R, Yue P, Tsao P, Nestorova G, Huang M, Hirschberg DL, Yock PG, Quertermous T, Wu JC. Transcriptome alteration in the diabetic heart by rosiglitazone: implications for cardiovascular mortality. PLoS One 2008; 3:e2609. [PMID: 18648539 PMCID: PMC2481284 DOI: 10.1371/journal.pone.0002609] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 06/04/2008] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Recently, the type 2 diabetes medication, rosiglitazone, has come under scrutiny for possibly increasing the risk of cardiac disease and death. To investigate the effects of rosiglitazone on the diabetic heart, we performed cardiac transcriptional profiling and imaging studies of a murine model of type 2 diabetes, the C57BL/KLS-lepr(db)/lepr(db) (db/db) mouse. METHODS AND FINDINGS We compared cardiac gene expression profiles from three groups: untreated db/db mice, db/db mice after rosiglitazone treatment, and non-diabetic db/+ mice. Prior to sacrifice, we also performed cardiac magnetic resonance (CMR) and echocardiography. As expected, overall the db/db gene expression signature was markedly different from control, but to our surprise was not significantly reversed with rosiglitazone. In particular, we have uncovered a number of rosiglitazone modulated genes and pathways that may play a role in the pathophysiology of the increase in cardiac mortality as seen in several recent meta-analyses. Specifically, the cumulative upregulation of (1) a matrix metalloproteinase gene that has previously been implicated in plaque rupture, (2) potassium channel genes involved in membrane potential maintenance and action potential generation, and (3) sphingolipid and ceramide metabolism-related genes, together give cause for concern over rosiglitazone's safety. Lastly, in vivo imaging studies revealed minimal differences between rosiglitazone-treated and untreated db/db mouse hearts, indicating that rosiglitazone's effects on gene expression in the heart do not immediately turn into detectable gross functional changes. CONCLUSIONS This study maps the genomic expression patterns in the hearts of the db/db murine model of diabetes and illustrates the impact of rosiglitazone on these patterns. The db/db gene expression signature was markedly different from control, and was not reversed with rosiglitazone. A smaller number of unique and interesting changes in gene expression were noted with rosiglitazone treatment. Further study of these genes and molecular pathways will provide important insights into the cardiac decompensation associated with both diabetes and rosiglitazone treatment.
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Affiliation(s)
- Kitchener D. Wilson
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, United States of America
| | - Zongjin Li
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Roger Wagner
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Patrick Yue
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Phillip Tsao
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Gergana Nestorova
- Human Immune Monitoring Center, Stanford University School of Medicine, Stanford, California, United States of America
| | - Mei Huang
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - David L. Hirschberg
- Human Immune Monitoring Center, Stanford University School of Medicine, Stanford, California, United States of America
| | - Paul G. Yock
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, United States of America
| | - Thomas Quertermous
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Joseph C. Wu
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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44
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Abstract
The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.
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Affiliation(s)
- E Dale Abel
- Department of Biology, York University, Toronto, Canada
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45
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Baranowski M, Blachnio-Zabielska A, Zabielski P, Gorski J. Pioglitazone induces lipid accumulation in the rat heart despite concomitant reduction in plasma free fatty acid availability. Arch Biochem Biophys 2008; 477:86-91. [PMID: 18541139 DOI: 10.1016/j.abb.2008.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/19/2008] [Accepted: 05/21/2008] [Indexed: 10/22/2022]
Abstract
Thiazolidinediones are insulin-sensitizing drugs which have been proved to be effective in the treatment of type 2 diabetes. However, the action of thiazolidinediones on myocardial metabolism is only poorly recognized. Therefore, the aim of our study was to investigate the effects of two-week pioglitazone treatment (3 mg/kg/d) on lipid and carbohydrate metabolism in the heart of rats fed on a standard chow or on a high-fat diet (HFD) for three weeks. High-fat feeding increased myocardial protein expression of all peroxisome proliferator-activated receptor (PPAR) isoforms. The greatest response was, however, noted in the case of PPARgamma. Surprisingly, administration of pioglitazone induced accumulation of free fatty acids (FFA) and diacylglycerol in the heart in both groups, despite concomitant reduction in plasma FFA concentration. The content of triacylglycerol was increased only in the HFD group. Pioglitazone treatment also shifted myocardial substrate utilization towards greater contribution of glucose in both groups, as evidenced by decreased rate of palmitate oxidation and higher 2-deoxyglucose uptake and elevated glycogen content. This could induce a mismatch between the rate of myocardial fatty acid uptake and oxidation leading to increased intracellular availability of fatty acids for non-oxidative metabolic pathways like synthesis of acylglycerols. Our data suggests that thiazolidinediones improve cardiac insulin sensitivity by mechanisms other than reduction in intramyocardial lipid content.
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Affiliation(s)
- Marcin Baranowski
- Department of Physiology, Medical University of Bialystok, Mickiewicza 2c, 15-230 Bialystok, Poland.
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46
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Muise ES, Azzolina B, Kuo DW, El-Sherbeini M, Tan Y, Yuan X, Mu J, Thompson JR, Berger JP, Wong KK. Adipose fibroblast growth factor 21 is up-regulated by peroxisome proliferator-activated receptor gamma and altered metabolic states. Mol Pharmacol 2008; 74:403-12. [PMID: 18467542 DOI: 10.1124/mol.108.044826] [Citation(s) in RCA: 228] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adipose tissue is a metabolically responsive endocrine organ that secretes a myriad of adipokines. Antidiabetic drugs such as peroxisome proliferator-activated receptor (PPAR) gamma agonists target adipose tissue gene expression and correct hyperglycemia via whole-body insulin sensitization. The mechanism by which altered gene expression in adipose tissue affects liver and muscle insulin sensitivity (and thus glucose homeostasis) is not fully understood. One possible mechanism involves the alteration in adipokine secretion, in particular the up-regulation of secreted factors that increase whole-body insulin sensitivity. Here, we report the use of transcriptional profiling to identify genes encoding for secreted proteins the expression of which is regulated by PPARgamma agonists. Of the 379 genes robustly regulated by two structurally distinct PPARgamma agonists in the epididymal white adipose tissue (EWAT) of db/db mice, 33 encoded for known secreted proteins, one of which was FGF21. Although FGF21 was recently reported to be up-regulated in cultured adipocytes by PPARgamma agonists and in liver by PPARalpha agonists and induction of ketotic states, we demonstrate that the protein is transcriptionally up-regulated in adipose tissue in vivo by PPARgamma agonist treatment and under a variety of physiological conditions, including fasting and high fat diet feeding. In addition, we found that circulating levels of FGF21 protein were increased upon treatment with PPARgamma agonists and under ketogenic states. These results suggest a role for FGF21 in mediating the antidiabetic activities of PPARgamma agonists.
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Affiliation(s)
- Eric S Muise
- Departments of Molecular Profiling, Merck Research Laboratories, P.O. Box 2000, Rahway, NJ 07065, USA
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47
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Chang CH, McNamara LA, Wu MS, Muise ES, Tan Y, Wood HB, Meinke PT, Thompson JR, Doebber TW, Berger JP, McCann ME. A novel selective peroxisome proliferator-activator receptor-γ modulator—SPPARγM5 improves insulin sensitivity with diminished adverse cardiovascular effects. Eur J Pharmacol 2008; 584:192-201. [DOI: 10.1016/j.ejphar.2007.12.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 11/28/2007] [Accepted: 12/16/2007] [Indexed: 11/25/2022]
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48
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Larsen TS, Aasum E. Metabolic (In)Flexibility of the Diabetic Heart. Cardiovasc Drugs Ther 2008; 22:91-5. [DOI: 10.1007/s10557-008-6083-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 01/17/2008] [Indexed: 10/22/2022]
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49
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Kim JY, van de Wall E, Laplante M, Azzara A, Trujillo ME, Hofmann SM, Schraw T, Durand JL, Li H, Li G, Jelicks LA, Mehler MF, Hui DY, Deshaies Y, Shulman GI, Schwartz GJ, Scherer PE. Obesity-associated improvements in metabolic profile through expansion of adipose tissue. J Clin Invest 2007; 117:2621-37. [PMID: 17717599 PMCID: PMC1950456 DOI: 10.1172/jci31021] [Citation(s) in RCA: 973] [Impact Index Per Article: 57.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 05/31/2007] [Indexed: 02/06/2023] Open
Abstract
Excess caloric intake can lead to insulin resistance. The underlying reasons are complex but likely related to ectopic lipid deposition in nonadipose tissue. We hypothesized that the inability to appropriately expand subcutaneous adipose tissue may be an underlying reason for insulin resistance and beta cell failure. Mice lacking leptin while overexpressing adiponectin showed normalized glucose and insulin levels and dramatically improved glucose as well as positively affected serum triglyceride levels. Therefore, modestly increasing the levels of circulating full-length adiponectin completely rescued the diabetic phenotype in ob/ob mice. They displayed increased expression of PPARgamma target genes and a reduction in macrophage infiltration in adipose tissue and systemic inflammation. As a result, the transgenic mice were morbidly obese, with significantly higher levels of adipose tissue than their ob/ob littermates, leading to an interesting dichotomy of increased fat mass associated with improvement in insulin sensitivity. Based on these data, we propose that adiponectin acts as a peripheral "starvation" signal promoting the storage of triglycerides preferentially in adipose tissue. As a consequence, reduced triglyceride levels in the liver and muscle convey improved systemic insulin sensitivity. These mice therefore represent what we believe is a novel model of morbid obesity associated with an improved metabolic profile.
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Affiliation(s)
- Ja-Young Kim
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Esther van de Wall
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mathieu Laplante
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Anthony Azzara
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Maria E. Trujillo
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Susanna M. Hofmann
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Todd Schraw
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jorge L. Durand
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hua Li
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Guangyu Li
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Linda A. Jelicks
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mark F. Mehler
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - David Y. Hui
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yves Deshaies
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Gerald I. Shulman
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Gary J. Schwartz
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Philipp E. Scherer
- Department of Cell Biology and
Department of Medicine, Albert Einstein College of Medicine, New York, New York, USA.
Department of Anatomy and Physiology, Laval University Hospital Centre Research Centre, Laval University School of Medicine, Quebec City, Quebec, Canada.
Department of Pathology, Genome Research Institute, University of Cincinnati, Cincinnati, Ohio, USA.
Department of Physiology and Biophysics and
Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, USA.
Department of Internal Medicine and Department of Cellular and Molecular Physiology, Yale University School of Medicine, and Howard Hughes Medical Institute, New Haven, Connecticut, USA.
Department of Molecular Pharmacology and
Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York, USA.
Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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50
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Aasum E, Khalid AM, Gudbrandsen OA, How OJ, Berge RK, Larsen TS. Fenofibrate modulates cardiac and hepatic metabolism and increases ischemic tolerance in diet-induced obese mice. J Mol Cell Cardiol 2007; 44:201-9. [PMID: 17931655 DOI: 10.1016/j.yjmcc.2007.08.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 08/21/2007] [Accepted: 08/23/2007] [Indexed: 10/22/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) play an important role in the transcriptional regulation of lipid utilization and storage in several organs, including liver and heart. Our working hypothesis is that treatment of obesity/hyperlipedemia with the PPARalpha ligand fenofibrate leads to drainage of plasma lipids by the liver, resulting in reduced myocardial lipid supply, reduced myocardial fatty acid oxidation and improved myocardial tolerance to ischemic stress. Thus, we investigated changes in substrate utilization in heart and liver, as well as post-ischemic functional recovery in hearts from diet-induced obese (DIO) mice following long-term (11-12 weeks) treatment with fenofibrate. The present study shows that DIO mice express increased plasma lipids and glucose, as well as increased myocardial fatty acid oxidation and a concomitant decrease in glucose oxidation. The lipid-lowering effect of fenofibrate was associated with increased hepatic mitochondrial and peroxisomal fatty acid oxidation, as indicated by a more than 30% increase in hepatic palmiotyl-CoA oxidation and more than a 10-fold increase in acyl-CoA oxidase (ACO) activity. In line with an adaptation to the reduced myocardial lipid supply, isolated hearts from fenofibrate-treated DIO mice showed increased glucose oxidation and decreased fatty acid oxidation, as well as reduced ACO activity. Fenofibrate treatment also prevented the diet-induced decrease in cardiac function and improved post-ischemic functional recovery. We also found that, while fenofibrate treatment markedly increased the expression of PPARalpha target genes in the liver, there were no such changes in the heart. These data demonstrate that fenofibrate results in a direct activation of PPARalpha in the liver with increased hepatic drainage of plasma lipids, while the cardiac effect of the compound most likely is secondary to its lipid-lowering effect.
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Affiliation(s)
- Ellen Aasum
- Department of Medical Physiology, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, N-9037 Tromsø, Norway.
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