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Lin LC, Liu ZY, Yang JJ, Zhao JY, Tao H. Lipid metabolism reprogramming in cardiac fibrosis. Trends Endocrinol Metab 2024; 35:164-175. [PMID: 37949734 DOI: 10.1016/j.tem.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 11/12/2023]
Abstract
Cardiac fibrosis is a critical pathophysiological process that occurs with diverse types of cardiac injury. Lipids are the most important bioenergy substrates for maintaining optimal heart performance and act as second messengers to transduce signals within cardiac cells. However, lipid metabolism reprogramming is a double-edged sword in the regulation of cardiomyocyte homeostasis and heart function. Moreover, lipids can exert diverse effects on cardiac fibrosis through different signaling pathways. In this review, we provide a brief overview of aberrant cardiac lipid metabolism and recent progress in pharmacological research targeting lipid metabolism alterations in cardiac fibrosis.
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Affiliation(s)
- Li-Chan Lin
- Department of Anesthesiology and Perioperative Medicine, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China
| | - Zhi-Yan Liu
- Department of Anesthesiology and Perioperative Medicine, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China
| | - Jing-Jing Yang
- Department of Clinical Pharmacology, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China.
| | - Jian-Yuan Zhao
- Institute for Developmental and Regenerative Cardiovascular Medicine, MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| | - Hui Tao
- Department of Anesthesiology and Perioperative Medicine, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China; Department of Cardiothoracic Surgery, The Second Affiliated Hospital of Anhui Medical University, Hefei, 230601, China.
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2
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Li X, Bi X. Integrated Control of Fatty Acid Metabolism in Heart Failure. Metabolites 2023; 13:615. [PMID: 37233656 PMCID: PMC10220550 DOI: 10.3390/metabo13050615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/18/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Disrupted fatty acid metabolism is one of the most important metabolic features in heart failure. The heart obtains energy from fatty acids via oxidation. However, heart failure results in markedly decreased fatty acid oxidation and is accompanied by the accumulation of excess lipid moieties that lead to cardiac lipotoxicity. Herein, we summarized and discussed the current understanding of the integrated regulation of fatty acid metabolism (including fatty acid uptake, lipogenesis, lipolysis, and fatty acid oxidation) in the pathogenesis of heart failure. The functions of many enzymes and regulatory factors in fatty acid homeostasis were characterized. We reviewed their contributions to the development of heart failure and highlighted potential targets that may serve as promising new therapeutic strategies.
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Affiliation(s)
| | - Xukun Bi
- Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Department of Cardiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China;
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3
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Althaher AR. An Overview of Hormone-Sensitive Lipase (HSL). ScientificWorldJournal 2022; 2022:1964684. [PMID: 36530555 PMCID: PMC9754850 DOI: 10.1155/2022/1964684] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 07/30/2023] Open
Abstract
Hormone-sensitive lipase (HSL) is a pivotal enzyme that mediates triglyceride hydrolysis to provide free fatty acids and glycerol in adipocytes in a hormonally controlled lipolysis process. Elevated plasma-free fatty acids were accompanied by insulin resistance, type-2 diabetes, and obesity. Inhibition of lipolysis through HSL inhibition may provide a mechanism to prevent the accumulation of free fatty acids and to improve the affectability of insulin and blood glucose handling in type II diabetes. The published studies that examine the structure, regulation, and function of HSL and major inhibitors were reviewed in this paper.
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Affiliation(s)
- Arwa R. Althaher
- Department of Pharmacy, Al-Zaytoonah University of Jordan, Amman 11733, Jordan
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4
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Yamada M, Suzuki J, Sato S, Zenimaru Y, Saito R, Konoshita T, Kraemer FB, Ishizuka T. Hormone-sensitive lipase protects adipose triglyceride lipase-deficient mice from lethal lipotoxic cardiomyopathy. J Lipid Res 2022; 63:100194. [PMID: 35283217 PMCID: PMC9062333 DOI: 10.1016/j.jlr.2022.100194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/31/2022] Open
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5
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Tuleta I, Frangogiannis NG. Fibrosis of the diabetic heart: Clinical significance, molecular mechanisms, and therapeutic opportunities. Adv Drug Deliv Rev 2021; 176:113904. [PMID: 34331987 PMCID: PMC8444077 DOI: 10.1016/j.addr.2021.113904] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 01/02/2023]
Abstract
In patients with diabetes, myocardial fibrosis may contribute to the pathogenesis of heart failure and arrhythmogenesis, increasing ventricular stiffness and delaying conduction. Diabetic myocardial fibrosis involves effects of hyperglycemia, lipotoxicity and insulin resistance on cardiac fibroblasts, directly resulting in increased matrix secretion, and activation of paracrine signaling in cardiomyocytes, immune and vascular cells, that release fibroblast-activating mediators. Neurohumoral pathways, cytokines, growth factors, oxidative stress, advanced glycation end-products (AGEs), and matricellular proteins have been implicated in diabetic fibrosis; however, the molecular links between the metabolic perturbations and activation of a fibrogenic program remain poorly understood. Although existing therapies using glucose- and lipid-lowering agents and neurohumoral inhibition may act in part by attenuating myocardial collagen deposition, specific therapies targeting the fibrotic response are lacking. This review manuscript discusses the clinical significance, molecular mechanisms and cell biology of diabetic cardiac fibrosis and proposes therapeutic targets that may attenuate the fibrotic response, preventing heart failure progression.
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Affiliation(s)
- Izabela Tuleta
- The Wilf Family Cardiovascular Research Institute, Department of Medicine (Cardiology), Albert Einstein College of Medicine, Bronx NY, USA
| | - Nikolaos G Frangogiannis
- The Wilf Family Cardiovascular Research Institute, Department of Medicine (Cardiology), Albert Einstein College of Medicine, Bronx NY, USA.
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6
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Wu Q, Zhao M, He X, Xue R, Li D, Yu X, Wang S, Zang W. Acetylcholine reduces palmitate-induced cardiomyocyte apoptosis by promoting lipid droplet lipolysis and perilipin 5-mediated lipid droplet-mitochondria interaction. Cell Cycle 2021; 20:1890-1906. [PMID: 34424820 DOI: 10.1080/15384101.2021.1965734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Lipid droplets (LDs), which are neutral lipid storage organelles, are important for lipid metabolism and energy homeostasis. LD lipolysis and interactions with mitochondria are tightly coupled to cellular metabolism and may be potential targets to buffer the effects of excessive toxic lipid species levels. Acetylcholine (ACh), the major neurotransmitter of the vagus nerve, exhibits cardioprotective effects. However, limited research has focused on its effects on LD lipolysis and the LD-mitochondria association in fatty acid (FA) overload models. Here, we reveal that palmitate (PA) induces an increase in expression of the FA transport protein cluster of differentiation 36 (CD36) and LD formation; remarkably reduces the expression of lipases involved in triacylglycerol (TAG) lipolysis, such as adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and monoacylglycerol lipase (MGL); impairs LD-mitochondria interaction; and decreases perilipin 5 (PLIN5) expression, resulting in LD accumulation and mitochondrial dysfunction, which ultimately lead to cardiomyocyte apoptosis. ACh significantly upregulates PLIN5 expression and improved LD lipolysis and the LD-mitochondria association. Moreover, ACh reduces CD36 expression, LD deposition and mitochondrial dysfunction, ultimately suppressing apoptosis in PA-treated neonatal rat ventricular cardiomyocytes (NRVCs). Knockdown of PLIN5, which plays a role in LD-mitochondria contact site formation, abolishes the protective effects of ACh in PA-treated NRVCs. Thus, ACh protects cardiomyocytes from PA-induced apoptosis, at least partly, by promoting LD lipolysis and activating LD-mitochondria interactions via PLIN5. These findings may aid in developing novel therapeutic approaches that target LD lipolysis and PLIN5-mediated LD-mitochondria interactions to prevent or alleviate lipotoxic cardiomyopathy.
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Affiliation(s)
- Qing Wu
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Ming Zhao
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Xi He
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Runqing Xue
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Dongling Li
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Xiaojiang Yu
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Shengpeng Wang
- Cardiovascular Research Center, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, P.R. China
| | - Weijin Zang
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
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7
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Kostić M, Korićanac G, Tepavčević S, Stanišić J, Romić S, Ćulafić T, Ivković T, Stojiljković M. Low-intensity exercise diverts cardiac fatty acid metabolism from triacylglycerol synthesis to beta oxidation in fructose-fed rats. Arch Physiol Biochem 2021:1-11. [PMID: 33612014 DOI: 10.1080/13813455.2021.1886118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
CONTEXT Excessive fructose consumption causes ectopic lipid storage leading to metabolic disorders and cardiovascular diseases associated with defective substrate utilisation in the heart. OBJECTIVE Examining the preventive impact of low-intensity exercise on alterations related to fructose-rich diet (FRD) on cardiac fatty acid (FA) transport and metabolism. MATERIALS AND METHODS Male Wistar rats were divided into control and two groups that received 10% fructose for 9 weeks, one of which was additionally exposed to exercise. RESULTS FRD elevated plasma and cardiac TAG, FATP1 in plasma membrane, Lipin 1 in microsomes and HSL mRNA, while mitochondrial CPT1 was decreased. Exercise decreased plasma free FA level, raised CD36 in plasma membrane and FATP1 in lysate, mitochondrial CPT1 and decreased microsomal Lipin 1 in fructose-fed rats. CONCLUSIONS FRD changed plasma lipids and augmented partitioning of FA to TAG storage in the heart, whereas exercise in FRD rats switched metabolism of FA towards β-oxidation.
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Affiliation(s)
- Milan Kostić
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Goran Korićanac
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Snežana Tepavčević
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Jelena Stanišić
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Snježana Romić
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Tijana Ćulafić
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Tamara Ivković
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Mojca Stojiljković
- Department for Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
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8
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Recazens E, Mouisel E, Langin D. Hormone-sensitive lipase: sixty years later. Prog Lipid Res 2020; 82:101084. [PMID: 33387571 DOI: 10.1016/j.plipres.2020.101084] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/12/2020] [Accepted: 12/24/2020] [Indexed: 12/19/2022]
Abstract
Hormone-sensitive lipase (HSL) was initially characterized as the hormonally regulated neutral lipase activity responsible for the breakdown of triacylglycerols into fatty acids in adipose tissue. This review aims at providing up-to-date information on structural properties, regulation of expression, activity and function as well as therapeutic potential. The lipase is expressed as different isoforms produced from tissue-specific alternative promoters. All isoforms are composed of an N-terminal domain and a C-terminal catalytic domain within which a regulatory domain containing the phosphorylation sites is embedded. Some isoforms possess additional N-terminal regions. The catalytic domain shares similarities with bacteria, fungus and vascular plant proteins but not with other mammalian lipases. HSL singularity is provided by regulatory and N-terminal domains sharing no homology with other proteins. HSL has a broad substrate specificity compared to other neutral lipases. It hydrolyzes acylglycerols, cholesteryl and retinyl esters among other substrates. A novel role of HSL, independent of its enzymatic function, has recently been described in adipocytes. Clinical studies revealed dysregulations of HSL expression and activity in disorders, such as lipodystrophy, obesity, type 2 diabetes and cancer-associated cachexia. Development of specific inhibitors positions HSL as a pharmacological target for the treatment of metabolic complications.
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Affiliation(s)
- Emeline Recazens
- Institute of Metabolic and Cardiovascular Diseases, Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, 31432 Toulouse, France; University of Toulouse, Paul Sabatier University, UMR1297, Toulouse, France
| | - Etienne Mouisel
- Institute of Metabolic and Cardiovascular Diseases, Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, 31432 Toulouse, France; University of Toulouse, Paul Sabatier University, UMR1297, Toulouse, France
| | - Dominique Langin
- Institute of Metabolic and Cardiovascular Diseases, Institut National de la Santé et de la Recherche Médicale (Inserm), UMR1297, 31432 Toulouse, France; University of Toulouse, Paul Sabatier University, UMR1297, Toulouse, France; Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague and Paul Sabatier University, Toulouse, France; Toulouse University Hospitals, Laboratory of Clinical Biochemistry, Toulouse, France.
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9
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Kintscher U, Foryst-Ludwig A, Haemmerle G, Zechner R. The Role of Adipose Triglyceride Lipase and Cytosolic Lipolysis in Cardiac Function and Heart Failure. CELL REPORTS MEDICINE 2020; 1:100001. [PMID: 33205054 PMCID: PMC7659492 DOI: 10.1016/j.xcrm.2020.100001] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Heart failure is one of the leading causes of death worldwide. New therapeutic concepts are urgently required to lower the burden of heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), the two major forms of heart failure. Lipolytic processes are induced during the development of heart failure and occur in adipose tissue and multiple organs, including the heart. Increasing evidence suggests that cellular lipolysis, in particular, adipose triglyceride lipase (ATGL) activity, has an important function in cardiac (patho)physiology. This review summarizes the crucial role of cellular lipolysis for normal cardiac function and for the development of HFrEF and HFpEF. We discuss the most relevant pre-clinical studies and elaborate on the cardiac consequences of non-myocardial and myocardial lipolysis modulation. Finally, we critically analyze the therapeutic importance of pharmacological ATGL inhibition as a potential treatment option for HFrEF and/or HFpEF in the future.
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Affiliation(s)
- Ulrich Kintscher
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Pharmacology, Center for Cardiovascular Research, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
- Corresponding author
| | - Anna Foryst-Ludwig
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Pharmacology, Center for Cardiovascular Research, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Einstein BIH Visiting Fellow, Berlin Institute of Health, and Charité - Universitätsmedizin Berlin, Berlin, Germany
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10
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Sato S, Suzuki J, Hirose M, Yamada M, Zenimaru Y, Nakaya T, Ichikawa M, Imagawa M, Takahashi S, Ikuyama S, Konoshita T, Kraemer FB, Ishizuka T. Cardiac overexpression of perilipin 2 induces atrial steatosis, connexin 43 remodeling, and atrial fibrillation in aged mice. Am J Physiol Endocrinol Metab 2019; 317:E1193-E1204. [PMID: 31661297 PMCID: PMC6957375 DOI: 10.1152/ajpendo.00227.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Atrial fibrillation (AF) is prevalent in patients with obesity and diabetes, and such patients often exhibit cardiac steatosis. Since the role of cardiac steatosis per se in the induction of AF has not been elucidated, the present study was designed to explore the relation between cardiac steatosis and AF. Transgenic (Tg) mice with cardiac-specific overexpression of perilipin 2 (PLIN2) were housed in the laboratory for more than 12 mo before the study. Electron microscopy of the atria of PLIN2-Tg mice showed accumulation of small lipid droplets around mitochondrial chains, and five- to ninefold greater atrial triacylglycerol (TAG) content compared with wild-type (WT) mice. Electrocardiography showed significantly longer RR intervals in PLIN2-Tg mice than in WT mice. Transesophageal electrical burst pacing resulted in significantly higher prevalence of sustained (>5 min) AF (69%) in PLIN2-Tg mice than in WT mice (24%), although it was comparable in younger (4-mo-old) mice. Connexin 43 (Cx43), a gap junction protein, was localized at the intercalated disks in WT atria but was heterogeneously distributed on the lateral side of cardiomyocytes in PLIN2-Tg atria. Langendorff-perfused hearts using the optical mapping technique showed slower and heterogeneous impulse propagation in PLIN2-Tg atria compared with WT atria. Cardiac overexpression of hormone-sensitive lipase in PLIN2-Tg mice resulted in atrial TAG depletion and amelioration of AF susceptibility. The results suggest that PLIN2-induced steatosis is associated with Cx43 remodeling, impaired conduction propagation, and higher incidence of AF in aged mice. Therapies targeting cardiac steatosis could be potentially beneficial against AF in patients with obesity or diabetes.
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Affiliation(s)
- Satsuki Sato
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Jinya Suzuki
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Masamichi Hirose
- Department of Molecular and Cellular Pharmacology, Iwate Medical University School of Pharmaceutical Sciences, Iwate, Japan
| | - Mika Yamada
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Yasuo Zenimaru
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Takahiro Nakaya
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Mai Ichikawa
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Michiko Imagawa
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Sadao Takahashi
- Division of Diabetes Medicine, Ageo Central General Hospital, Saitama, Japan
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan
| | - Shoichiro Ikuyama
- Division of Endocrinology and Metabolism, Oita San-ai Medical Center, Oita, Japan
| | - Tadashi Konoshita
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Fredric B Kraemer
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Division of Endocrinology, Stanford University, Stanford, California
| | - Tamotsu Ishizuka
- Third Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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11
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Ussher JR, Campbell JE, Mulvihill EE, Baggio LL, Bates HE, McLean BA, Gopal K, Capozzi M, Yusta B, Cao X, Ali S, Kim M, Kabir MG, Seino Y, Suzuki J, Drucker DJ. Inactivation of the Glucose-Dependent Insulinotropic Polypeptide Receptor Improves Outcomes following Experimental Myocardial Infarction. Cell Metab 2018; 27:450-460.e6. [PMID: 29275960 DOI: 10.1016/j.cmet.2017.11.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 10/15/2017] [Accepted: 11/15/2017] [Indexed: 12/15/2022]
Abstract
Incretin hormones exert pleiotropic metabolic actions beyond the pancreas. Although the heart expresses both incretin receptors, the cardiac biology of GIP receptor (GIPR) action remains incompletely understood. Here we show that GIPR agonism did not impair the response to cardiac ischemia. In contrast, genetic elimination of the Gipr reduced myocardial infarction (MI)-induced ventricular injury and enhanced survival associated with reduced hormone sensitive lipase (HSL) phosphorylation; it also increased myocardial triacylglycerol (TAG) stores. Conversely, direct GIPR agonism in the isolated heart reduced myocardial TAG stores and increased fatty acid oxidation. The cardioprotective phenotype in Gipr-/- mice was partially reversed by pharmacological activation or genetic overexpression of HSL. Selective Gipr inactivation in cardiomyocytes phenocopied Gipr-/- mice, resulting in improved survival and reduced adverse remodeling following experimental MI. Hence, the cardiomyocyte GIPR regulates fatty acid metabolism and the adaptive response to ischemic cardiac injury. These findings have translational relevance for developing GIPR-based therapeutics.
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Affiliation(s)
- John R Ussher
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jonathan E Campbell
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada; Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - Erin E Mulvihill
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Laurie L Baggio
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Holly E Bates
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Brent A McLean
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Keshav Gopal
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Megan Capozzi
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - Bernardo Yusta
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Xiemin Cao
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Safina Ali
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Minsuk Kim
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - M Golam Kabir
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Yutaka Seino
- Kansai Electric Power Hospital and Medical Research Institute, 2-1-7 Fukushima-ku, Osaka 553-0003, Japan
| | - Jinya Suzuki
- Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Daniel J Drucker
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON M5G 1X5, Canada.
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12
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Ueno M, Suzuki J, Hirose M, Sato S, Imagawa M, Zenimaru Y, Takahashi S, Ikuyama S, Koizumi T, Konoshita T, Kraemer FB, Ishizuka T. Cardiac overexpression of perilipin 2 induces dynamic steatosis: prevention by hormone-sensitive lipase. Am J Physiol Endocrinol Metab 2017; 313:E699-E709. [PMID: 28851734 PMCID: PMC6415650 DOI: 10.1152/ajpendo.00098.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 08/24/2017] [Accepted: 08/24/2017] [Indexed: 11/22/2022]
Abstract
Cardiac intracellular lipid accumulation (steatosis) is a pathophysiological phenomenon observed in starvation and diabetes mellitus. Perilipin 2 (PLIN2) is a lipid droplet (LD)-associated protein expressed in nonadipose tissues, including the heart. To explore the pathophysiological function of myocardial PLIN2, we generated transgenic (Tg) mice by cardiac-specific overexpression of PLIN2. Tg hearts showed accumulation of numerous small LDs associated with mitochondrial chains and high cardiac triacylglycerol (TAG) content [8-fold greater than wild-type (WT) mice]. Despite massive steatosis, cardiac uptake of glucose, fatty acids and VLDL, systolic function, and expression of metabolic genes were comparable in the two genotypes, and no morphological changes were observed by electron microscopy in the Tg hearts. Twenty-four hours of fasting markedly reduced steatosis in Tg hearts, whereas WT mice showed accumulation of LDs. Although activity of adipose triglyceride lipase in heart homogenate was comparable between WT and Tg mice, activity of hormone-sensitive lipase (HSL) was 40-50% less in Tg than WT mice under both feeding and fasting conditions, suggesting interference of PLIN2 with HSL. Mice generated through crossing of PLIN2-Tg mice and HSL-Tg mice showed cardiac-specific HSL overexpression and complete lack of steatosis. The results suggest that cardiac PLIN2 plays an important pathophysiological role in the development of dynamic steatosis and that the latter was prevented by upregulation of intracellular lipases, including HSL.
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Affiliation(s)
- Masami Ueno
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California; and
- Division of Endocrinology, Stanford University, Stanford, California
| | - Jinya Suzuki
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan;
| | | | - Satsuki Sato
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
| | - Michiko Imagawa
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
| | - Yasuo Zenimaru
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
| | - Sadao Takahashi
- Division of Diabetes Medicine, Ageo Central General Hospital, Saitama, Japan
| | - Shoichiro Ikuyama
- Division of Endocrinology and Metabolism, Oita San-ai Medical Center, Oita, Japan
| | - Tsutomu Koizumi
- Research and Education Program for Life Science, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
| | - Tadashi Konoshita
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
| | - Fredric B Kraemer
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California; and
- Division of Endocrinology, Stanford University, Stanford, California
| | - Tamotsu Ishizuka
- Third Department of Internal Medicine, University of Fukui, Faculty of Medical Sciences, Fukui, Japan
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13
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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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14
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Ritchie RH, Zerenturk EJ, Prakoso D, Calkin AC. Lipid metabolism and its implications for type 1 diabetes-associated cardiomyopathy. J Mol Endocrinol 2017; 58:R225-R240. [PMID: 28373293 DOI: 10.1530/jme-16-0249] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/03/2017] [Indexed: 12/13/2022]
Abstract
Diabetic cardiomyopathy was first defined over four decades ago. It was observed in small post-mortem studies of diabetic patients who suffered from concomitant heart failure despite the absence of hypertension, coronary disease or other likely causal factors, as well as in large population studies such as the Framingham Heart Study. Subsequent studies continue to demonstrate an increased incidence of heart failure in the setting of diabetes independent of established risk factors, suggesting direct effects of diabetes on the myocardium. Impairments in glucose metabolism and handling receive the majority of the blame. The role of concomitant impairments in lipid handling, particularly at the level of the myocardium, has however received much less attention. Cardiac lipid accumulation commonly occurs in the setting of type 2 diabetes and has been suggested to play a direct causal role in the development of cardiomyopathy and heart failure in a process termed as cardiac lipotoxicity. Excess lipids promote numerous pathological processes linked to the development of cardiomyopathy, including mitochondrial dysfunction and inflammation. Although somewhat underappreciated, cardiac lipotoxicity also occurs in the setting of type 1 diabetes. This phenomenon is, however, largely understudied in comparison to hyperglycaemia, which has been widely studied in this context. The current review addresses the changes in lipid metabolism occurring in the type 1 diabetic heart and how they are implicated in disease progression. Furthermore, the pathological pathways linked to cardiac lipotoxicity are discussed. Finally, we consider novel approaches for modulating lipid metabolism as a cardioprotective mechanism against cardiomyopathy and heart failure.
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Affiliation(s)
- Rebecca H Ritchie
- Heart Failure PharmacologyBaker Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Central Clinical SchoolMonash University, Melbourne, Victoria, Australia
| | - Eser J Zerenturk
- Lipid Metabolism & Cardiometabolic Disease LaboratoryBaker Heart & Diabetes Institute, Melbourne, Victoria, Australia
| | - Darnel Prakoso
- Heart Failure PharmacologyBaker Heart & Diabetes Institute, Melbourne, Victoria, Australia
- School of BiosciencesThe University of Melbourne, Parkville, Victoria, Australia
| | - Anna C Calkin
- Central Clinical SchoolMonash University, Melbourne, Victoria, Australia
- Lipid Metabolism & Cardiometabolic Disease LaboratoryBaker Heart & Diabetes Institute, Melbourne, Victoria, Australia
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15
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Zlobine I, Gopal K, Ussher JR. Lipotoxicity in obesity and diabetes-related cardiac dysfunction. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1555-68. [DOI: 10.1016/j.bbalip.2016.02.011] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 02/15/2016] [Indexed: 12/11/2022]
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16
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Evans RD, Hauton D. The role of triacylglycerol in cardiac energy provision. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1481-91. [DOI: 10.1016/j.bbalip.2016.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 02/07/2023]
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17
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Tomasetti M, Amati M, Santarelli L, Neuzil J. MicroRNA in Metabolic Re-Programming and Their Role in Tumorigenesis. Int J Mol Sci 2016; 17:E754. [PMID: 27213336 PMCID: PMC4881575 DOI: 10.3390/ijms17050754] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/27/2016] [Accepted: 05/11/2016] [Indexed: 12/13/2022] Open
Abstract
The process of metabolic re-programing is linked to the activation of oncogenes and/or suppression of tumour suppressor genes, which are regulated by microRNAs (miRNAs). The interplay between oncogenic transformation-driven metabolic re-programming and modulation of aberrant miRNAs further established their critical role in the initiation, promotion and progression of cancer by creating a tumorigenesis-prone microenvironment, thus orchestrating processes of evasion to apoptosis, angiogenesis and invasion/migration, as well metastasis. Given the involvement of miRNAs in tumour development and their global deregulation, they may be perceived as biomarkers in cancer of therapeutic relevance.
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Affiliation(s)
- Marco Tomasetti
- Department of Clinical and Molecular Sciences, Polytechnic University of Marche, Ancona 60020, Italy.
| | - Monica Amati
- Department of Clinical and Molecular Sciences, Polytechnic University of Marche, Ancona 60020, Italy.
| | - Lory Santarelli
- Department of Clinical and Molecular Sciences, Polytechnic University of Marche, Ancona 60020, Italy.
| | - Jiri Neuzil
- Mitochondria, Apoptosis and Cancer Research Group, School of Medical Science and Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia.
- Molecular Therapy Group, Institute of Biotechnology, Czech Academy of Sciences, Prague-West 25243, Czech Republic.
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18
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Lipid metabolism and signaling in cardiac lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1513-24. [PMID: 26924249 DOI: 10.1016/j.bbalip.2016.02.016] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 02/19/2016] [Accepted: 02/19/2016] [Indexed: 01/01/2023]
Abstract
The heart balances uptake, metabolism and oxidation of fatty acids (FAs) to maintain ATP production, membrane biosynthesis and lipid signaling. Under conditions where FA uptake outpaces FA oxidation and FA sequestration as triacylglycerols in lipid droplets, toxic FA metabolites such as ceramides, diacylglycerols, long-chain acyl-CoAs, and acylcarnitines can accumulate in cardiomyocytes and cause cardiomyopathy. Moreover, studies using mutant mice have shown that dysregulation of enzymes involved in triacylglycerol, phospholipid, and sphingolipid metabolism in the heart can lead to the excess deposition of toxic lipid species that adversely affect cardiomyocyte function. This review summarizes our current understanding of lipid uptake, metabolism and signaling pathways that have been implicated in the development of lipotoxic cardiomyopathy under conditions including obesity, diabetes, aging, and myocardial ischemia-reperfusion. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
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19
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Heier C, Haemmerle G. Fat in the heart: The enzymatic machinery regulating cardiac triacylglycerol metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1500-12. [PMID: 26924251 DOI: 10.1016/j.bbalip.2016.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 01/22/2023]
Abstract
The heart predominantly utilizes fatty acids (FAs) as energy substrate. FAs that enter cardiomyocytes can be activated and directly oxidized within mitochondria (and peroxisomes) or they can be esterified and intracellularly deposited as triacylglycerol (TAG) often simply referred to as fat. An increase in cardiac TAG can be a signature of the diseased heart and may implicate a minor role of TAG synthesis and breakdown in normal cardiac energy metabolism. Often overlooked, the heart has an extremely high TAG turnover and the transient deposition of FAs within the cardiac TAG pool critically determines the availability of FAs as energy substrate and signaling molecules. We herein review the recent literature regarding the enzymes and co-regulators involved in cardiomyocyte TAG synthesis and catabolism and discuss the interconnection of these metabolic pathways in the normal and diseased heart. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
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Affiliation(s)
- Christoph Heier
- Institute of Molecular Biosciences, University of Graz, Austria
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20
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Abdesselam I, Pepino P, Troalen T, Macia M, Ancel P, Masi B, Fourny N, Gaborit B, Giannesini B, Kober F, Dutour A, Bernard M. Time course of cardiometabolic alterations in a high fat high sucrose diet mice model and improvement after GLP-1 analog treatment using multimodal cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2015; 17:95. [PMID: 26546347 PMCID: PMC4636800 DOI: 10.1186/s12968-015-0198-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/28/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Cardiovascular complications of obesity and diabetes are major health problems. Assessing their development, their link with ectopic fat deposition and their flexibility with therapeutic intervention is essential. The aim of this study was to longitudinally investigate cardiac alterations and ectopic fat accumulation associated with diet-induced obesity using multimodal cardiovascular magnetic resonance (CMR) in mice. The second objective was to monitor cardiac response to exendin-4 (GLP-1 receptor agonist). METHODS Male C57BL6R mice subjected to a high fat (35 %) high sucrose (34 %) (HFHSD) or a standard diet (SD) during 4 months were explored every month with multimodal CMR to determine hepatic and myocardial triglyceride content (HTGC, MTGC) using proton MR spectroscopy, cardiac function with cine cardiac MR (CMR) and myocardial perfusion with arterial spin labeling CMR. Furthermore, mice treated with exendin-4 (30 μg/kg SC BID) after 4 months of diet were explored before and 14 days post-treatment with multimodal CMR. RESULTS HFHSD mice became significantly heavier (+33 %) and displayed glucose homeostasis impairment (1-month) as compared to SD mice, and developed early increase in HTGC (1 month, +59 %) and MTGC (2-month, +63 %). After 3 months, HFHSD mice developed cardiac dysfunction with significantly higher diastolic septum wall thickness (sWtnD) (1.28 ± 0.03 mm vs. 1.12 ± 0.03 mm) and lower cardiac index (0.45 ± 0.06 mL/min/g vs. 0.68 ± 0.07 mL/min/g, p = 0.02) compared to SD mice. A significantly lower cardiac perfusion was also observed (4 months:7.5 ± 0.8 mL/g/min vs. 10.0 ± 0.7 mL/g/min, p = 0.03). Cardiac function at 4 months was negatively correlated to both HTGC and MTGC (p < 0.05). 14-day treatment with Exendin-4 (Ex-4) dramatically reversed all these alterations in comparison with placebo-treated HFHSD. Ex-4 diminished myocardial triglyceride content (-57.8 ± 4.1 %), improved cardiac index (+38.9 ± 10.9 %) and restored myocardial perfusion (+52.8 ± 16.4 %) under isoflurane anesthesia. Interestingly, increased wall thickness and hepatic steatosis reductions were independent of weight loss and glycemia decrease in multivariate analysis (p < 0.05). CONCLUSION CMR longitudinal follow-up of cardiac consequences of obesity and diabetes showed early accumulation of ectopic fat in mice before the occurrence of microvascular and contractile dysfunction. This study also supports a cardioprotective effect of glucagon-like peptide-1 receptor agonist.
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Affiliation(s)
- Inès Abdesselam
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
| | - Pauline Pepino
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Thomas Troalen
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Michael Macia
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Patricia Ancel
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
| | - Brice Masi
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Natacha Fourny
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Bénédicte Gaborit
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
- Endocrinology, Metabolic diseases and nutrition, CHU Nord, Marseille, France
| | - Benoît Giannesini
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Frank Kober
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Anne Dutour
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
- Endocrinology, Metabolic diseases and nutrition, CHU Nord, Marseille, France
| | - Monique Bernard
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France.
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21
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Impaired fatty acid oxidation as a cause for lipotoxicity in cardiomyocytes. Biochem Biophys Res Commun 2015; 468:73-8. [PMID: 26546819 DOI: 10.1016/j.bbrc.2015.10.162] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 10/30/2015] [Indexed: 12/15/2022]
Abstract
A major cause for diabetic cardiomyopathy is excess lipid accumulation. To elucidate mechanisms of lipotoxicity mediated diabetic heart disease we need to further our understanding of how lipid metabolism is altered in the diabetic heart. Here we investigated the role of lipid clearance by oxidation as a regulator of lipid-mediated toxicity (lipotoxicity). We evaluated the effect of pre-treating rat neonatal cardiomyocytes (NCMs) with either oleate (mono-unsaturated fatty acid) or palmitate (saturated fatty acid) on fatty acid oxidation (FAO) by measuring (14)C-CO2 production. We evaluated carnitine palmitoyltransferase (Cpt1b) expression by western blotting and mitochondrial membrane potential by quantitative and qualitative fluorescence analyses using the JC-1 dye. We inhibited the Cpt1b pharmacologically using etomoxir and genetically by knocking down its expression using LentiVector mediated transduction of siRNAs targeting the Cpt1b gene. We found that palmitate had a slower clearance rate from NCMs than oleate, and this was associated with a significant decrease in FAO. This impairment in FAO was not the result of either loss of Cpt1b protein or mitochondrial integrity. Enhancing FAO with either oleate or carnitine was associated with a significant attenuation of palmitate mediated lipotoxicity. In contrast impairing FAO in oleate treated NCMs caused lipotoxicity. Here we demonstrate that a major difference between non-toxic unsaturated fatty acids and toxic saturated fatty acids is there ability to stimulate or inhibit fatty acid oxidation, respectively. This has important implications for diabetic cardiomyopathy since diabetic hearts consistently exhibit elevated lipid accumulation.
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22
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Osumi T, Kuramoto K. Heart lipid droplets and lipid droplet-binding proteins: Biochemistry, physiology, and pathology. Exp Cell Res 2015; 340:198-204. [PMID: 26524506 DOI: 10.1016/j.yexcr.2015.10.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/29/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Affiliation(s)
- Takashi Osumi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678-1297, Japan.
| | - Kenta Kuramoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678-1297, Japan
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23
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Sung MM, Hamza SM, Dyck JRB. Myocardial metabolism in diabetic cardiomyopathy: potential therapeutic targets. Antioxid Redox Signal 2015; 22:1606-30. [PMID: 25808033 DOI: 10.1089/ars.2015.6305] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
SIGNIFICANCE Cardiovascular complications in diabetes are particularly serious and represent the primary cause of morbidity and mortality in diabetic patients. Despite early observations of cardiac dysfunction in diabetic humans, cardiomyopathy unique to diabetes has only recently been recognized. RECENT ADVANCES Research has focused on understanding the pathogenic mechanisms underlying the initiation and development of diabetic cardiomyopathy. Emerging data highlight the importance of altered mitochondrial function as a major contributor to cardiac dysfunction in diabetes. Mitochondrial dysfunction occurs by several mechanisms involving altered cardiac substrate metabolism, lipotoxicity, impaired cardiac insulin and glucose homeostasis, impaired cellular and mitochondrial calcium handling, oxidative stress, and mitochondrial uncoupling. CRITICAL ISSUES Currently, treatment is not specifically tailored for diabetic patients with cardiac dysfunction. Given the multifactorial development and progression of diabetic cardiomyopathy, traditional treatments such as anti-diabetic agents, as well as cellular and mitochondrial fatty acid uptake inhibitors aimed at shifting the balance of cardiac metabolism from utilizing fat to glucose may not adequately target all aspects of this condition. Thus, an alternative treatment such as resveratrol, which targets multiple facets of diabetes, may represent a safe and promising supplement to currently recommended clinical therapy and lifestyle changes. FUTURE DIRECTIONS Elucidation of the mechanisms underlying the initiation and progression of diabetic cardiomyopathy is essential for development of effective and targeted treatment strategies. Of particular interest is the investigation of alternative therapies such as resveratrol, which can function as both preventative and mitigating agents in the management of diabetic cardiomyopathy.
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Affiliation(s)
- Miranda M Sung
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Shereen M Hamza
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Jason R B Dyck
- Department of Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
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24
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Abdurrachim D, Luiken JJFP, Nicolay K, Glatz JFC, Prompers JJ, Nabben M. Good and bad consequences of altered fatty acid metabolism in heart failure: evidence from mouse models. Cardiovasc Res 2015; 106:194-205. [PMID: 25765936 DOI: 10.1093/cvr/cvv105] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/18/2015] [Indexed: 12/25/2022] Open
Abstract
The shift in substrate preference away from fatty acid oxidation (FAO) towards increased glucose utilization in heart failure has long been interpreted as an oxygen-sparing mechanism. Inhibition of FAO has therefore evolved as an accepted approach to treat heart failure. However, recent data indicate that increased reliance on glucose might be detrimental rather than beneficial for the failing heart. This review discusses new insights into metabolic adaptations in heart failure. A particular focus lies on data obtained from mouse models with modulations of cardiac FA metabolism at different levels of the FA metabolic pathway and how these differently affect cardiac function. Based on studies in which these mouse models were exposed to ischaemic and non-ischaemic heart failure, we discuss whether and when modulations in FA metabolism are protective against heart failure.
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Affiliation(s)
- Desiree Abdurrachim
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, High Tech Campus 11, 5656 AE, PO BOX 513, Eindhoven 5600 MB, The Netherlands
| | - Joost J F P Luiken
- Department of Genetics and Cell Biology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, High Tech Campus 11, 5656 AE, PO BOX 513, Eindhoven 5600 MB, The Netherlands
| | - Jan F C Glatz
- Department of Genetics and Cell Biology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, High Tech Campus 11, 5656 AE, PO BOX 513, Eindhoven 5600 MB, The Netherlands
| | - Miranda Nabben
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, High Tech Campus 11, 5656 AE, PO BOX 513, Eindhoven 5600 MB, The Netherlands Department of Genetics and Cell Biology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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25
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Cardiomyocyte lipotoxicity is mediated by Il-6 and causes down-regulation of PPARs. Biochem Biophys Res Commun 2015; 459:54-9. [DOI: 10.1016/j.bbrc.2015.02.062] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 02/11/2015] [Indexed: 12/12/2022]
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26
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Fatty acid signaling: the new function of intracellular lipases. Int J Mol Sci 2015; 16:3831-55. [PMID: 25674855 PMCID: PMC4346929 DOI: 10.3390/ijms16023831] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 11/19/2014] [Accepted: 01/21/2015] [Indexed: 12/21/2022] Open
Abstract
Until recently, intracellular triacylglycerols (TAG) stored in the form of cytoplasmic lipid droplets have been considered to be only passive “energy conserves”. Nevertheless, degradation of TAG gives rise to a pleiotropic spectrum of bioactive intermediates, which may function as potent co-factors of transcription factors or enzymes and contribute to the regulation of numerous cellular processes. From this point of view, the process of lipolysis not only provides energy-rich equivalents but also acquires a new regulatory function. In this review, we will concentrate on the role that fatty acids liberated from intracellular TAG stores play as signaling molecules. The first part provides an overview of the transcription factors, which are regulated by fatty acids derived from intracellular stores. The second part is devoted to the role of fatty acid signaling in different organs/tissues. The specific contribution of free fatty acids released by particular lipases, hormone-sensitive lipase, adipose triacylglycerol lipase and lysosomal lipase will also be discussed.
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27
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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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Fuentes-Antrás J, Picatoste B, Gómez-Hernández A, Egido J, Tuñón J, Lorenzo Ó. Updating experimental models of diabetic cardiomyopathy. J Diabetes Res 2015; 2015:656795. [PMID: 25973429 PMCID: PMC4417999 DOI: 10.1155/2015/656795] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/26/2015] [Accepted: 03/29/2015] [Indexed: 11/17/2022] Open
Abstract
Diabetic cardiomyopathy entails a serious cardiac dysfunction induced by alterations in structure and contractility of the myocardium. This pathology is initiated by changes in energy substrates and occurs in the absence of atherothrombosis, hypertension, or other cardiomyopathies. Inflammation, hypertrophy, fibrosis, steatosis, and apoptosis in the myocardium have been studied in numerous diabetic experimental models in animals, mostly rodents. Type I and type II diabetes were induced by genetic manipulation, pancreatic toxins, and fat and sweet diets, and animals recapitulate the main features of human diabetes and related cardiomyopathy. In this review we update and discuss the main experimental models of diabetic cardiomyopathy, analysing the associated metabolic, structural, and functional abnormalities, and including current tools for detection of these responses. Also, novel experimental models based on genetic modifications of specific related genes have been discussed. The study of specific pathways or factors responsible for cardiac failures may be useful to design new pharmacological strategies for diabetic patients.
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Affiliation(s)
- J. Fuentes-Antrás
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
| | - B. Picatoste
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
| | - A. Gómez-Hernández
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
- Biochemistry and Molecular Biology Department, School of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain
| | - J. Egido
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
| | - J. Tuñón
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
| | - Ó. Lorenzo
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
- *Ó. Lorenzo:
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Deficiency of a lipid droplet protein, perilipin 5, suppresses myocardial lipid accumulation, thereby preventing type 1 diabetes-induced heart malfunction. Mol Cell Biol 2014; 34:2721-31. [PMID: 24820416 DOI: 10.1128/mcb.00133-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Lipid droplet (LD) is a ubiquitous organelle that stores triacylglycerol and other neutral lipids. Perilipin 5 (Plin5), a member of the perilipin protein family that is abundantly expressed in the heart, is essential to protect LDs from attack by lipases, including adipose triglyceride lipase. Plin5 controls heart metabolism and performance by maintaining LDs under physiological conditions. Aberrant lipid accumulation in the heart leads to organ malfunction, or cardiomyopathy. To elucidate the role of Plin5 in a metabolically disordered state and the mechanism of lipid-induced cardiomyopathy, we studied the effects of streptozotocin-induced type 1 diabetes in Plin5-knockout (KO) mice. In contrast to diabetic wild-type mice, diabetic Plin5-KO mice lacked detectable LDs in the heart and did not exhibit aberrant lipid accumulation, excessive reactive oxygen species (ROS) generation, or heart malfunction. Moreover, diabetic Plin5-KO mice exhibited lower heart levels of lipotoxic molecules, such as diacylglycerol and ceramide, than wild-type mice. Membrane translocation of protein kinase C and the assembly of NADPH oxidase 2 complex on the membrane were also suppressed. The results suggest that diabetic Plin5-KO mice are resistant to type 1 diabetes-induced heart malfunction due to the suppression of the diacylglycerol/ceramide-protein kinase C pathway and of excessive ROS generation by NADPH oxidase.
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Glenn DJ, Cardema MC, Ni W, Zhang Y, Yeghiazarians Y, Grapov D, Fiehn O, Gardner DG. Cardiac steatosis potentiates angiotensin II effects in the heart. Am J Physiol Heart Circ Physiol 2014; 308:H339-50. [PMID: 25485904 DOI: 10.1152/ajpheart.00742.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lipid accumulation in the heart is associated with obesity and diabetes and may play an important role in the pathogenesis of heart failure. The renin-angiotensin system is also thought to contribute to cardiovascular morbidity in obese and diabetic patients. We hypothesized that the presence of lipid within the myocyte might potentiate the cardiomyopathic effects of ANG II in the cardiac diacylglycerol acyl transferase 1 (DGAT1) transgenic mouse model of myocyte steatosis. Treatment with ANG II resulted in a similar increase in blood pressure in both nontransgenic and DGAT1 transgenic mice. However, ANG II in DGAT1 transgenic mice resulted in a marked increase in interstitial fibrosis and a reduction in systolic function compared with nontransgenic littermates. Lipidomic analysis revealed that >20% of lipid species were significantly altered between nontransgenic and DGAT1 transgenic animals, whereas 3% were responsive to ANG II administration. ROS were also increased by ANG II in DGAT1 transgenic hearts. ANG II treatment resulted in increased expression of transforming growth factor (TGF)-β2 and the type I TGF-β receptor as well as increased phosphorylation of Smad2 in DGAT1 transgenic hearts. Injection of neutralizing antibodies to TGF-β resulted in a reduction in fibrosis in DGAT1 transgenic hearts treated with ANG II. These results suggest that myocyte steatosis amplifies the fibrotic effects of ANG II through mechanisms that involve activation of TGF-β signaling and increased production of ROS.
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Affiliation(s)
- Denis J Glenn
- Department of Medicine and the Diabetes Center, University of California, San Francisco, California;
| | - Michelle C Cardema
- Department of Medicine and the Diabetes Center, University of California, San Francisco, California
| | - Wei Ni
- Department of Medicine and the Diabetes Center, University of California, San Francisco, California
| | - Yan Zhang
- Division of Cardiology, Department of Medicine, University of California, San Francisco, California; and
| | - Yerem Yeghiazarians
- Division of Cardiology, Department of Medicine, University of California, San Francisco, California; and
| | - Dmitry Grapov
- West Coast Metabolomics Center, Genome Center, University of California, Davis, California
| | - Oliver Fiehn
- West Coast Metabolomics Center, Genome Center, University of California, Davis, California
| | - David G Gardner
- Department of Medicine and the Diabetes Center, University of California, San Francisco, California
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Zhang Z, Wang S, Zhou S, Yan X, Wang Y, Chen J, Mellen N, Kong M, Gu J, Tan Y, Zheng Y, Cai L. Sulforaphane prevents the development of cardiomyopathy in type 2 diabetic mice probably by reversing oxidative stress-induced inhibition of LKB1/AMPK pathway. J Mol Cell Cardiol 2014; 77:42-52. [PMID: 25268649 DOI: 10.1016/j.yjmcc.2014.09.022] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/28/2014] [Accepted: 09/18/2014] [Indexed: 12/22/2022]
Abstract
Type 2 diabetes mellitus (T2DM)-induced cardiomyopathy is associated with cardiac oxidative stress, inflammation, and remodeling. Sulforaphane (SFN), an isothiocyanate naturally presenting in widely consumed vegetables, particularly broccoli, plays an important role in cardiac protection from diabetes. We investigated the effect of SFN on T2DM-induced cardiac lipid accumulation and subsequent cardiomyopathy. Male C57BL/6J mice were fed a high-fat diet for 3months to induce insulin resistance, followed by a treatment with 100mg/kg body-weight streptozotocin to induce hyperglycemia; we referred to it as the T2DM mouse model. Other age-matched mice were fed a normal diet as control. T2DM and control mice were treated with or without 4-month SFN at 0.5mg/kg daily five days a week. At the study's end, cardiac function was assessed. SFN treatment significantly attenuated cardiac remodeling and dysfunction induced by T2DM. SFN treatment also significantly inhibited cardiac lipid accumulation, measured by Oil Red O staining, and improved cardiac inflammation oxidative stress and fibrosis, shown by down-regulating diabetes-induced PAI-1, TNF-α, CTGF, TGF-β, 3-NT, and 4-HNE expression. Elevated 4-HNE resulted in the increase of 4-HNE-LKB1 adducts that should inhibit LKB1 and subsequent AMPK activity. SFN upregulated the expression of Nrf2 and its downstream genes, NQO1 and HO-1, decreased 4-HNE-LKB1 adducts and then reversed diabetes-induced inhibition of LKB1/AMPK and its downstream targets, including sirtuin 1, PGC-1α, phosphorylated acetyl-CoA carboxylase, carnitine palmitoyl transferase-1, ULK1, and light chain-3 II. These results suggest that SFN treatment to T2DM mice may attenuate the cardiac oxidative stress-induced inhibition of LKB1/AMPK signaling pathway, thereby preventing T2DM-induced lipotoxicity and cardiomyopathy.
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Affiliation(s)
- Zhiguo Zhang
- Department of Cardiology at the First Hospital of Jilin University, Changchun 130021, China; Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Shudong Wang
- Department of Cardiology at the First Hospital of Jilin University, Changchun 130021, China; Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Shanshan Zhou
- Department of Cardiology at the First Hospital of Jilin University, Changchun 130021, China; Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Xiaoqing Yan
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA; The Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou 325035, China
| | - Yonggang Wang
- Department of Cardiology at the First Hospital of Jilin University, Changchun 130021, China; Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Jing Chen
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Nicholas Mellen
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA
| | - Maiying Kong
- Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, KY 40202, USA
| | - Junlian Gu
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA; Department of Pathology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, China
| | - Yi Tan
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA; The Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou 325035, China
| | - Yang Zheng
- Department of Cardiology at the First Hospital of Jilin University, Changchun 130021, China.
| | - Lu Cai
- Kosair Children Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville 40202, USA; The Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou 325035, China.
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Park S, Fujishita C, Komatsu T, Kim SE, Chiba T, Mori R, Shimokawa I. NPY antagonism reduces adiposity and attenuates age-related imbalance of adipose tissue metabolism. FASEB J 2014; 28:5337-48. [PMID: 25205743 DOI: 10.1096/fj.14-258384] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
An orexigenic hormone, neuropeptide Y (NPY), plays a role not only in the hypothalamic regulation of appetite, but also in the peripheral regulation of lipid metabolism. However, the intracellular mechanisms triggered by NPY to regulate lipid metabolism are poorly understood. Here we report that NPY deficiency reduces white adipose tissue (WAT) mass and ameliorates the age-related imbalance of adipose tissue metabolism in mice. Gene expression involved in adipogenesis/lipogenesis was found to decrease, whereas proteins involved in lipolysis increased in gonadal WAT (gWAT) of NPY-knockout mice. These changes were associated with an activated SIRT1- and PPARγ-mediated pathway. Moreover, the age-related decrease of de novo lipogenesis in gWAT and thermogenesis in inguinal WAT was inhibited by NPY deficiency. Further analysis using 3T3-L1 cells showed that NPY inhibited lipolysis through the Y1 receptor and enhanced lipogenesis following a reduction in cAMP response element-binding protein (CREB) and SIRT1 protein expression. Therefore, NPY appears to act as a key regulator of adipose tissue metabolism via the CREB-SIRT1 signaling pathway. Taken together, NPY deficiency reduces adiposity and ameliorates the age-related imbalance of adipose tissue metabolism, suggesting that antagonism of NPY may be a promising target for drug development to prevent age-related metabolic diseases.
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Affiliation(s)
- Seongjoon Park
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Chika Fujishita
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Toshimitsu Komatsu
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Sang Eun Kim
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Takuya Chiba
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Ryoichi Mori
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
| | - Isao Shimokawa
- Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University School of Medicine, Nagasaki City, Japan
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Abstract
The incidence of heart failure (HF) and diabetes mellitus is rapidly increasing and is associated with poor prognosis. In spite of the advances in therapy, HF remains a major health problem with high morbidity and mortality. When HF and diabetes coexist, clinical outcomes are significantly worse. The relationship between these two conditions has been studied in various experimental models. However, the mechanisms for this interrelationship are complex, incompletely understood, and have become a matter of considerable clinical and research interest. There are only few animal models that manifest both HF and diabetes. However, the translation of results from these models to human disease is limited, and new models are needed to expand our current understanding of this clinical interaction. In this review, we discuss mechanisms of insulin signaling and insulin resistance, the clinical association between insulin resistance and HF, and its proposed pathophysiologic mechanisms. Finally, we discuss available animal models of insulin resistance and HF and propose requirements for future new models.
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Abstract
Cardiomyopathy, the presence of cardiac dysfunction independent of ischemic heart disease and/or hypertension, is becoming a more prominent condition in our diabetic patient population. Unfortunately, we do not yet understand the mechanism(s) responsible for causing diabetic cardiomyopathy. With the recent explosion in the obesity and Type 2 diabetes epidemic, our understanding of dyslipidemia and the adverse effects of lipid surplus on cellular and organ function has grown considerably. Numerous studies now illustrate that excess lipid accumulation may exert direct toxic effects on cellular function, a term coined 'lipotoxicity'. As obesity and Type 2 diabetes are significant risk factors for cardiovascular disease, cardiac lipotoxicity may represent a significant component mediating the diabetic cardiomyopathy phenotype. Therefore, a more complete understanding of how cardiac lipotoxicity is regulated and how different lipid metabolites cause cellular dysfunction may lead to the discovery of novel targets to treat cardiomyopathy in our diabetic patient population.
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Affiliation(s)
- John R Ussher
- Lunenfeld-Tanenbaum, Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
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35
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Ramírez E, Klett-Mingo M, Ares-Carrasco S, Picatoste B, Ferrarini A, Rupérez FJ, Caro-Vadillo A, Barbas C, Egido J, Tuñón J, Lorenzo Ó. Eplerenone attenuated cardiac steatosis, apoptosis and diastolic dysfunction in experimental type-II diabetes. Cardiovasc Diabetol 2013; 12:172. [PMID: 24261558 PMCID: PMC4222723 DOI: 10.1186/1475-2840-12-172] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/09/2013] [Indexed: 12/26/2022] Open
Abstract
Background Cardiac steatosis and apoptosis are key processes in diabetic cardiomyopathy, but the underlying mechanisms have not been elucidated, leading to a lack of effective therapy. The mineralocorticoid receptor blocker, eplerenone, has demonstrated anti-fibrotic actions in the diabetic heart. However, its effects on the fatty-acid accumulation and apoptotic responses have not been revealed. Methods Non-hypertensive Zucker Diabetic Fatty (ZDF) rats received eplerenone (25 mg/kg) or vehicle. Zucker Lean (ZL) rats were used as control (n = 10, each group). After 16 weeks, cardiac structure and function was examined, and plasma and hearts were isolated for biochemical and histological approaches. Cultured cardiomyocytes were used for in vitro assays to determine the direct effects of eplerenone on high fatty acid and high glucose exposed cells. Results In contrast to ZL, ZDF rats exhibited hyperglycemia, hyperlipidemia, insulin-resistance, cardiac steatosis and diastolic dysfunction. The ZDF myocardium also showed increased mitochondrial oxidation and apoptosis. Importantly, eplerenone mitigated these events without altering hyperglycemia. In cultured cardiomyocytes, high-concentrations of palmitate stimulated the fatty-acid uptake (in detriment of glucose assimilation), accumulation of lipid metabolites, mitochondrial dysfunction, and apoptosis. Interestingly, fatty-acid uptake, ceramides formation and apoptosis were also significantly ameliorated by eplerenone. Conclusions By blocking mineralocorticoid receptors, eplerenone may attenuate cardiac steatosis and apoptosis, and subsequent remodelling and diastolic dysfunction in obese/type-II diabetic rats.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Óscar Lorenzo
- Cardiovascular Pathology laboratory, IIS-Fundación Jiménez Díaz, Autónoma University, Av, Reyes Católicos 2, Madrid 28040 Spain.
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36
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Mitochondrial dysfunction induces formation of lipid droplets as a generalized response to stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:327167. [PMID: 24175011 PMCID: PMC3794647 DOI: 10.1155/2013/327167] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 08/20/2013] [Indexed: 01/05/2023]
Abstract
Lipid droplet (LD) formation is a hallmark of cellular stress. Cells attempt to combat noxious stimuli by switching their metabolism from oxidative phosphorylation to glycolysis, sparing resources in LDs for generating cellular reducing power and for anabolic biosynthesis. Membrane phospholipids are also a source of LDs. To elucidate the formation of LDs, we exposed mice to hyperoxia, hypoxia, myocardial ischemia, and sepsis induced by cecal ligation and puncture (CLP). All the above-mentioned stressors enhanced the formation of LDs, as assessed by transmission electron microscopy, with severe mitochondrial swelling. Disruption of mitochondria by depleting mitochondrial DNA ( ρ 0 cells) significantly augmented the formation of LDs, causing transcriptional activation of fatty acid biosynthesis and metabolic reprogramming to glycolysis. Heme oxygenase (HO)-1 counteracts CLP-mediated septic shock in mouse models. In HO-1-deficient mice, LD formation was not observed upon CLP, but a concomitant decrease in "LD-decorating proteins" was observed, implying a link between LDs and cytoprotective activity. Collectively, LD biogenesis during stress can trigger adaptive LD formation, which is dependent on mitochondrial integrity and HO-1 activity; this may be a cellular survival strategy, apportioning energy-generating substrates to cellular defense.
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Kienesberger PC, Pulinilkunnil T, Nagendran J, Young ME, Bogner-Strauss JG, Hackl H, Khadour R, Heydari E, Haemmerle G, Zechner R, Kershaw EE, Dyck JRB. Early structural and metabolic cardiac remodelling in response to inducible adipose triglyceride lipase ablation. Cardiovasc Res 2013; 99:442-51. [PMID: 23708736 DOI: 10.1093/cvr/cvt124] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIMS While chronic alterations in cardiac triacylglycerol (TAG) metabolism and accumulation are associated with cardiomyopathy, it is unclear whether TAG catabolizing enzymes such as adipose triglyceride lipase (ATGL) play a role in acquired cardiomyopathies. Importantly, germline deletion of ATGL leads to marked cardiac steatosis and heart failure in part through reducing peroxisome proliferator-activated receptor α (PPARα) activity and subsequent fatty acid oxidation (FAO). However, whether ATGL deficiency specifically in adult cardiomyocytes contributes to impaired PPARα activity, cardiac function, and metabolism is not known. METHODS AND RESULTS To study the effects of acquired cardiac ATGL deficiency on cardiac PPARα activity, function, and metabolism, we generated adult mice with tamoxifen-inducible cardiomyocyte-specific ATGL deficiency (icAtglKO). Within 4-6 weeks following ATGL ablation, icAtglKO mice had markedly increased myocardial TAG accumulation, fibrotic remodelling, and pathological hypertrophy. Echocardiographic analysis of hearts in vivo revealed that contractile function was moderately reduced in icAtglKO mice. Analysis of energy metabolism in ex vivo perfused working hearts showed diminished FAO rates which was not paralleled by markedly impaired PPARα target gene expression. CONCLUSIONS This study shows that acquired cardiomyocyte-specific ATGL deficiency in adult mice is sufficient to promote fibrotic and hypertrophic cardiomyopathy and impair myocardial FAO in the absence of markedly reduced PPARα signalling.
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Affiliation(s)
- Petra C Kienesberger
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada T6G 2S2
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Bround MJ, Wambolt R, Luciani DS, Kulpa JE, Rodrigues B, Brownsey RW, Allard MF, Johnson JD. Cardiomyocyte ATP production, metabolic flexibility, and survival require calcium flux through cardiac ryanodine receptors in vivo. J Biol Chem 2013; 288:18975-86. [PMID: 23678000 DOI: 10.1074/jbc.m112.427062] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Ca(2+) fluxes between adjacent organelles are thought to control many cellular processes, including metabolism and cell survival. In vitro evidence has been presented that constitutive Ca(2+) flux from intracellular stores into mitochondria is required for basal cellular metabolism, but these observations have not been made in vivo. We report that controlled in vivo depletion of cardiac RYR2, using a conditional gene knock-out strategy (cRyr2KO mice), is sufficient to reduce mitochondrial Ca(2+) and oxidative metabolism, and to establish a pseudohypoxic state with increased autophagy. Dramatic metabolic reprogramming was evident at the transcriptional level via Sirt1/Foxo1/Pgc1α, Atf3, and Klf15 gene networks. Ryr2 loss also induced a non-apoptotic form of programmed cell death associated with increased calpain-10 but not caspase-3 activation or endoplasmic reticulum stress. Remarkably, cRyr2KO mice rapidly exhibited many of the structural, metabolic, and molecular characteristics of heart failure at a time when RYR2 protein was reduced 50%, a similar degree to that which has been reported in heart failure. RYR2-mediated Ca(2+) fluxes are therefore proximal controllers of mitochondrial Ca(2+), ATP levels, and a cascade of transcription factors controlling metabolism and survival.
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Affiliation(s)
- Michael J Bround
- Cardiovascular Research Group, Life Sciences Institute, University of British Columbia, Vancouver V6T 1Z3, Canada
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39
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Pulinilkunnil T, Kienesberger PC, Nagendran J, Waller TJ, Young ME, Kershaw EE, Korbutt G, Haemmerle G, Zechner R, Dyck JR. Myocardial adipose triglyceride lipase overexpression protects diabetic mice from the development of lipotoxic cardiomyopathy. Diabetes 2013; 62:1464-77. [PMID: 23349479 PMCID: PMC3636613 DOI: 10.2337/db12-0927] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although diabetic cardiomyopathy is associated with enhanced intramyocardial triacylglycerol (TAG) levels, the role of TAG catabolizing enzymes in this process is unclear. Because the TAG hydrolase, adipose triglyceride lipase (ATGL), regulates baseline cardiac metabolism and function, we examined whether alterations in cardiomyocyte ATGL impact cardiac function during uncontrolled type 1 diabetes. In genetic (Akita) and pharmacological (streptozotocin) murine models of type 1 diabetes, cardiac ATGL protein expression and TAG content were significantly increased. To determine whether increased ATGL expression during diabetes is detrimental or beneficial to cardiac function, we studied streptozotocin-diabetic mice with heterozygous ATGL deficiency and cardiomyocyte-specific ATGL overexpression. After diabetes, streptozotocin-diabetic mice with heterozygous ATGL deficiency displayed increased TAG accumulation, lipotoxicity, and diastolic dysfunction comparable to wild-type mice. In contrast, myosin heavy chain promoter (MHC)-ATGL mice were resistant to diabetes-induced increases in intramyocardial TAG levels, lipotoxicity, and cardiac dysfunction. Moreover, hearts from diabetic MHC-ATGL mice exhibited decreased reliance on palmitate oxidation and blunted peroxisome proliferator--activated receptor-α activation. Collectively, this study shows that after diabetes, increased cardiac ATGL expression is an adaptive, albeit insufficient, response to compensate for the accumulation of myocardial TAG, and that overexpression of ATGL is sufficient to ameliorate diabetes-induced cardiomyopathy.
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Affiliation(s)
- Thomas Pulinilkunnil
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Petra C. Kienesberger
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jeevan Nagendran
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Terri J. Waller
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Martin E. Young
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Erin E. Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Gregory Korbutt
- Alberta Diabetes Institute and Cardiovascular Research Centre, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Jason R.B. Dyck
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Corresponding author: Jason R.B. Dyck,
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Kok BPC, Brindley DN. Myocardial fatty acid metabolism and lipotoxicity in the setting of insulin resistance. Heart Fail Clin 2012; 8:643-61. [PMID: 22999246 DOI: 10.1016/j.hfc.2012.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Management of diabetes and insulin resistance in the setting of cardiovascular disease has become an important issue in an increasingly obese society. Besides the development of hypertension and buildup of atherosclerotic plaques, the derangement of fatty acid and lipid metabolism in the heart plays an important role in promoting cardiac dysfunction and oxidative stress. This review discusses the mechanisms by which metabolic inflexibility in the use of fatty acids as the preferred cardiac substrate in diabetes produces detrimental effects on mechanical efficiency, mitochondrial function, and recovery from ischemia. Lipid accumulation and the consequences of toxic lipid metabolites are also discussed.
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Affiliation(s)
- Bernard P C Kok
- Signal Transduction Research Group, Department of Biochemistry, School of Translational Medicine, University of Alberta, 11207 87th Avenue, Edmonton, Alberta, Canada
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41
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Myocardial triacylglycerol metabolism. J Mol Cell Cardiol 2012; 55:101-10. [PMID: 22789525 DOI: 10.1016/j.yjmcc.2012.06.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 06/22/2012] [Accepted: 06/28/2012] [Indexed: 11/22/2022]
Abstract
Myocardial triacylglycerol (TAG) constitutes a highly dynamic fatty acid (FA) storage pool that can be used for an energy reserve in the cardiomyocyte. However, derangements in myocardial TAG metabolism and accumulation are commonly associated with cardiac disease, suggesting an important role of intramyocardial TAG turnover in the regulation of cardiac function. In cardiomyocytes, TAG is synthesized by acyltransferases and phosphatases at the sarcoplasmic reticulum and mitochondrial membrane and then packaged into cytosolic lipid droplets for temporary storage or into lipoproteins for secretion. A complex interplay among lipases, lipase regulatory proteins, and lipid droplet scaffold proteins leads to the controlled release of FAs from the cardiac TAG pool for subsequent mitochondrial β-oxidation and energy production. With the identification and characterization of proteins involved in myocardial TAG metabolism as well as the identification of the importance of cardiac TAG turnover, it is now evident that adequate regulation of myocardial TAG metabolism is critical for both cardiac energy metabolism and function. In this article, we review the current understanding of myocardial TAG metabolism and discuss the potential role of myocardial TAG turnover in cardiac health and disease. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism".
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Abstract
The heart has both the greatest caloric needs and the most robust oxidation of fatty acids (FAs). Under pathological conditions such as obesity and type 2 diabetes, cardiac uptake and oxidation are not balanced and hearts accumulate lipid potentially leading to cardiac lipotoxicity. We will first review the pathways utilized by the heart to acquire FAs from the circulation and to store triglyceride intracellularly. Then we will describe mouse models in which excess lipid accumulation causes heart dysfunction and experiments performed to alleviate this toxicity. Finally, the known relationships between heart lipid metabolism and dysfunction in humans will be summarized.
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Affiliation(s)
- Ira J Goldberg
- Department of Medicine, Columbia University, New York, NY 10032, USA.
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Ishizaka N, Hongo M, Sakamoto A, Saito K, Furuta K, Koike K. Liver lipid content is reduced in rat given 7-day administration of angiotensin II. J Renin Angiotensin Aldosterone Syst 2011; 12:462-8. [PMID: 21810895 DOI: 10.1177/1470320311415887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Activation of the renin-angiotensin system may be involved in the development of hepatic steatosis, a condition that is associated with insulin resistance. We showed that in rats, angiotensin II induced accumulation of triglycerides in the renal tubular and cardiac cells, although it significantly reduced the weight of the rats. Here we investigated the liver lipid content of rats given long-term angiotensin II administration. Angiotensin II (0.7 mg/kg/day) was infused into the rats for 7 days via an osmotic minipump. Some rats also received hydralazine or losartan concomitantly. It was shown that angiotensin II reduced oil red O-stainable lipid droplets (6% of the control value) and liver triglyceride content (angiotensin II: 4.6 ± 0.8 µg/mg, control: 11.7 ± 1.1 µg/mg). Both of these phenomena were blocked by losartan, but not by hydralazine. Angiotensin II infusion reduced the expression and activity of AMP-activated protein kinase. In addition, angiotensin II decreased the mRNA expression of peroxisome proliferator-activated receptor-α and genes related to β-oxidation, although mRNA expression of genes related to lipogenesis were not affected. Angiotensin II reduced triglyceride content in the liver, unlike in the kidney or heart, via an AT1 receptor-dependent mechanism.
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Affiliation(s)
- Nobukazu Ishizaka
- Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
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van de Weijer T, Schrauwen-Hinderling VB, Schrauwen P. Lipotoxicity in type 2 diabetic cardiomyopathy. Cardiovasc Res 2011; 92:10-8. [PMID: 21803867 DOI: 10.1093/cvr/cvr212] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
As obesity and type 2 diabetes are becoming an epidemic in westernized countries, the incidence and prevalence of obesity- and diabetes-related co-morbidities are increasing. In type 2 diabetes ectopic lipid accumulation in the heart has been associated with cardiac dysfunction and apoptosis, a process termed lipotoxicity. Since cardiovascular diseases are the main cause of death in diabetic patients, diagnosis and treatment become increasingly important. Although ischaemic heart disease is a major problem in diabetes, non-ischaemic heart disease (better known as diabetic cardiomyopathy) becomes increasingly important with respect to the impairment of cardiac function and mortality in type 2 diabetes. The underlying aetiology of diabetic cardiomyopathy is incompletely understood but is beginning to be elucidated. Various mechanisms have been proposed that may lead to lipotoxicity. Therefore, this review will focus on the mechanisms of cardiac lipid accumulation and its relation to the development of cardiomyopathy.
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Affiliation(s)
- Tineke van de Weijer
- Department of Human Biology, Maastricht University Medical Centre, PO Box 616, 6200 MD Maastricht, The Netherlands
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Jeckel KM, Miller KE, Chicco AJ, Chapman PL, Mulligan CM, Falcone PH, Miller ML, Pagliassotti MJ, Frye MA. The role of dietary fatty acids in predicting myocardial structure in fat-fed rats. Lipids Health Dis 2011; 10:92. [PMID: 21649916 PMCID: PMC3127789 DOI: 10.1186/1476-511x-10-92] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 06/07/2011] [Indexed: 12/27/2022] Open
Abstract
Background Obesity increases the risk for development of cardiomyopathy in the absence of hypertension, diabetes or myocardial ischemia. Not all obese individuals, however, progress to heart failure. Indeed, obesity may provide protection from cardiovascular mortality in some populations. The fatty acid milieu, modulated by diet, may modify obesity-induced myocardial structure and function, lending partial explanation for the array of cardiomyopathic phenotypy in obese individuals. Methods Adult male Sprague-Dawley rats were fed 1 of the following 4 diets for 32 weeks: control (CON); 50% saturated fat (SAT); 40% saturated fat + 10% linoleic acid (SAT+LA); 40% saturated fat + 10% α-linolenic acid (SAT+ALA). Serum leptin, insulin, glucose, free fatty acids and triglycerides were quantitated. In vivo cardiovascular outcomes included blood pressure, heart rate and echocardiographic measurements of structure and function. The rats were sacrificed and myocardium was processed for fatty acid analysis (TLC-GC), and evaluation of potential modifiers of myocardial structure including collagen (Masson's trichrome, hydroxyproline quantitation), lipid (Oil Red O, triglyceride quantitation) and myocyte cross sectional area. Results Rats fed SAT+LA and SAT+ALA diets had greater cranial LV wall thickness compared to rats fed CON and SAT diets, in the absence of hypertension or apparent insulin resistance. Treatment was not associated with changes in myocardial function. Myocardial collagen and triglycerides were similar among treatment groups; however, rats fed the high-fat diets, regardless of composition, demonstrated increased myocyte cross sectional area. Conclusions Under conditions of high-fat feeding, replacement of 10% saturated fat with either LA or ALA is associated with thickening of the cranial LV wall, but without concomitant functional changes. Increased myocyte size appears to be a more likely contributor to early LV thickening in response to high-fat feeding. These findings suggest that myocyte hypertrophy may be an early change leading to gross LV hypertrophy in the hearts of "healthy" obese rats, in the absence of hypertension, diabetes and myocardial ischemia.
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Affiliation(s)
- Kimberly M Jeckel
- Department of Biomedical Sciences, Campus delivery #1680, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Bupha-Intr T, Oo YW, Wattanapermpool J. Increased myocardial stiffness with maintenance of length-dependent calcium activation by female sex hormones in diabetic rats. Am J Physiol Heart Circ Physiol 2011; 300:H1661-8. [PMID: 21335468 DOI: 10.1152/ajpheart.00411.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A decrease in peak early diastolic filling velocity in postmenopausal women implies a sex hormone-related diastolic dysfunction. The regulatory effect of female sex hormones on cardiac distensibility therefore was evaluated in ovariectomized rats by determining the sarcomere length-passive tension relationship of ventricular skinned fiber preparations. Diabetes also was induced in the rat to assess the protective significance of female sex hormones on diastolic function. While ovariectomy had no effect on myocardial stiffness, collagen content, or titin ratio, a significant increase in myocardial stiffness was observed in diabetic rat only when female sex hormones were intact. The increased stiffness in diabetic-sham rats was accompanied by an elevated collagen content resulting from increases in the levels of procollagen and Smad2. Surprisingly, the increased myocardial stiffness in diabetic-sham rats was accompanied by a shift toward a more compliant N2BA of cardiac titin isoforms. The pCa-active tension relationship was analyzed at fixed sarcomere lengths of 2.0 and 2.3 μm to determine the magnitude of changes in myofilament Ca(2+) sensitivity between the two sarcomere lengths. Interestingly, high expression of N2BA titin was associated with a suppressed magnitude of changes in myofilament Ca(2+) sensitivity only in the diabetic-ovariectomized condition. Estrogen supplementation in diabetic-ovariectomized rats partially increased myocardial stiffness but completely reversed the change in myofilament Ca(2+) sensitivity. These results indicate a restrictive adaptation of myocardium governed by female sex hormones to maintain myofilament activity in compensation to the pathophysiological induction of cardiac dilatation by the diabetic condition.
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Affiliation(s)
- Tepmanas Bupha-Intr
- Faculty of Science, Department of Physiology, Mahidol University, Bangkok, Thailand.
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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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Abstract
PURPOSE OF REVIEW Diseases associated with ectopic disposition of lipids are becoming an increasingly important medical problem as the incidence of type 2 diabetes and obesity increases. One of the organs affected by lipotoxicity is the heart and this review presents an update on human and animal studies of this problem. RECENT FINDINGS Human studies have clearly correlated heart dysfunction with the content of triglyceride. More recently human heart samples have been used to assess gene changes associated with altered lipid accumulation. Genetically altered mice have been created that develop lipotoxic cardiomyopathies and newer investigations are attempting to delineate curative therapies. SUMMARY Human studies will confirm the metabolic changes associated with lipotoxic cardiomyopathy and, hopefully, animal studies will guide treatment options.
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Affiliation(s)
- Raffay S Khan
- Department of Medicine, Division of Preventive Medicine and Nutrition, Columbia University College of Physicians & Surgeons, New York, NY 10032, USA
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Current Opinion in Clinical Nutrition and Metabolic Care. Current world literature. Curr Opin Clin Nutr Metab Care 2010; 13:215-21. [PMID: 20145440 DOI: 10.1097/mco.0b013e32833643b4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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