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Cerf ME. Cardiac Glucolipotoxicity and Cardiovascular Outcomes. ACTA ACUST UNITED AC 2018; 54:medicina54050070. [PMID: 30344301 PMCID: PMC6262512 DOI: 10.3390/medicina54050070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 01/12/2023]
Abstract
Cardiac insulin signaling can be impaired due to the altered fatty acid metabolism to induce insulin resistance. In diabetes and insulin resistance, the metabolic, structural and ultimately functional alterations in the heart and vasculature culminate in diabetic cardiomyopathy, coronary artery disease, ischemia and eventually heart failure. Glucolipotoxicity describes the combined, often synergistic, adverse effects of elevated glucose and free fatty acid concentrations on heart structure, function, and survival. The quality of fatty acid shapes the cardiac structure and function, often influencing survival. A healthy fatty acid balance is therefore critical for maintaining cardiac integrity and function.
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Affiliation(s)
- Marlon E Cerf
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa.
- Division of Medical Physiology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg 7505, South Africa.
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Chen B, Huang Y, Zheng D, Ni R, Bernards MA. Dietary Fatty Acids Alter Lipid Profiles and Induce Myocardial Dysfunction without Causing Metabolic Disorders in Mice. Nutrients 2018; 10:nu10010106. [PMID: 29351259 PMCID: PMC5793334 DOI: 10.3390/nu10010106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/08/2018] [Accepted: 01/11/2018] [Indexed: 01/22/2023] Open
Abstract
Oversupply of bulk saturated fatty acids (SFA) induces metabolic disorders and myocardial dysfunction. We investigated whether, without causing metabolic disorders, the uptake of individual dietary SFA species alters lipid profiles and induces myocardial dysfunction. C57BL/6 mice were fed various customized long-chain SFA diets (40% caloric intake from SFA), including a beef tallow (HBD), cocoa butter (HCD), milk fat (HMD) and palm oil diet (HPD), for 6 months. An isocaloric fat diet, containing medium-chain triglycerides, served as a control (CHD). Long-term intake of dietary long-chain SFA differentially affected the fatty acid composition in cardiac phospholipids. All long-chain SFA diets increased the levels of arachidonic acid and total SFA in cardiac phospholipids. The preferential incorporation of individual SFA into the cardiac phospholipid fraction was dependent on the dietary SFA species. Cardiac ceramide content was elevated in all mice fed long-chain SFA diets, while cardiac hypertrophy was only presented in mice fed HMD or HPD. We have demonstrated that the intake of long-chain SFA species differentially alters cardiac lipid profiles and induces cardiac dysfunction, without causing remarkable metabolic disorders.
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Affiliation(s)
- Bainian Chen
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215000, China.
- Lawson Health Research Institute, London Health Sciences Centre, London, ON N6A 4G5, Canada.
- Department of Medicine, University of Western Ontario, London, ON N6A 5A5, Canada.
| | - Yifan Huang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215000, China.
- Department of Medicine, University of Western Ontario, London, ON N6A 5A5, Canada.
| | - Dong Zheng
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215000, China.
- Lawson Health Research Institute, London Health Sciences Centre, London, ON N6A 4G5, Canada.
- Department of Medicine, University of Western Ontario, London, ON N6A 5A5, Canada.
- Department of Pathology, University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Rui Ni
- Lawson Health Research Institute, London Health Sciences Centre, London, ON N6A 4G5, Canada.
- Department of Medicine, University of Western Ontario, London, ON N6A 5A5, Canada.
- Department of Pathology, University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Mark A Bernards
- Department of Biology, University of Western Ontario, London, ON N6A 2B7, Canada.
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Elevated expression of activated Na(+)/H(+) exchanger protein induces hypertrophy in isolated rat neonatal ventricular cardiomyocytes. Mol Cell Biochem 2011; 358:179-87. [PMID: 21720766 DOI: 10.1007/s11010-011-0933-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 06/21/2011] [Indexed: 10/18/2022]
Abstract
The plasma membrane protein the Na(+)/H(+) exchanger isoform1 (NHE1) has been implicated in various cardiac pathologies including ischemia/reperfusion damage to the myocardium and cardiac hypertrophy. Levels of NHE1 protein and activity are elevated in cardiac disease; however, the mechanism by which these factors contribute to the accompanying hypertrophy in the myocardium is still not clear. To investigate the mechanism of NHE1-induced hypertrophy in the myocardium we constructed two adenoviral vectors expressing either wild type NHE1 protein or a constitutively active NHE1 protein. Infection of neonatal rat ventricular cardiomyocytes (NRVM) resulted in elevated expression of both wild type NHE1 or constitutively active NHE1. Only expression of activated NHE1 protein resulted in an increase in cell size and in an increase in protein synthesis in isolated cardiomyocyte cells. The results demonstrate that expression of activated NHE1 promotes cardiac hypertrophy in isolated cardiac cells and that simple elevation of levels of wild type NHE1 protein does not have a significant hypertrophic effect in NRVM. The results suggest that regulation of NHE1 activity is a critical direct effector of the hypertrophic effect induced in the myocardium by the NHE1 protein.
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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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Fu M, Li RX, Fan L, He GW, Thornburg KL, Wang Z. Sarcoplasmic reticulum Ca2+ release channel ryanodine receptor (RyR2) plays a crucial role in aconitine-induced arrhythmias. Biochem Pharmacol 2008; 75:2147-56. [PMID: 18439986 DOI: 10.1016/j.bcp.2008.02.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Revised: 02/18/2008] [Accepted: 02/22/2008] [Indexed: 10/22/2022]
Abstract
The present study established a model of RyR(2) knockdown cardiomyocytes and elucidated the role of RyR(2) in aconitine-induced arrhythmia. Cardiomyocytes were obtained from hearts of neonatal Sprague-Dawley rats. siRNAs were used to down-regulate RyR(2) expression. Reduction of RyR(2) expression was documented by RT-PCR, western blot, and immunofluorescence. Ca(2+) signals were investigated by measuring the relative intracellular Ca(2+) concentration, spontaneous Ca(2+) oscillations, caffeine-induced Ca(2+) release, and L-type Ca(2+) currents. In normal cardiomyocytes, steady and periodic spontaneous Ca(2+) oscillations were observed, and the baseline [Ca(2+)](i) remained at the low level. Exposure to 3 microM aconitine increased the frequency and decreased the amplitude of Ca(2+) oscillations; the baseline [Ca(2+)](i) and the level of caffeine-induced Ca(2+) release were increased but the L-type Ca(2+) currents were inhibited after application of 3 microM aconitine for 5 min. In RyR(2) knockdown cardiomyocytes, the steady and periodic spontaneous Ca(2+) oscillations almost disappeared, but were re-induced by aconitine without affecting the baseline [Ca(2+)](i) level; the level of caffeine-induced Ca(2+) release was increased but L-type Ca(2+) currents were inhibited. Alterations of RyR(2) are important consequences of aconitine-stimulation and activation of RyR(2) appear to have a direct relationship with aconitine-induced arrhythmias. The present study demonstrates a potential method for preventing aconitine-induced arrhythmias by inhibiting Ca(2+) leakage through the sarcoplasmic reticulum RyR(2) channel.
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Affiliation(s)
- Min Fu
- School of Medicine and Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China
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Fu M, Wu M, Wang JF, Qiao YJ, Wang Z. Disruption of the intracellular Ca2+ homeostasis in the cardiac excitation-contraction coupling is a crucial mechanism of arrhythmic toxicity in aconitine-induced cardiomyocytes. Biochem Biophys Res Commun 2007; 354:929-36. [PMID: 17276394 DOI: 10.1016/j.bbrc.2007.01.082] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 01/15/2007] [Indexed: 11/18/2022]
Abstract
Aconitine is an effective ingredient in Aconite tuber, an important traditional Chinese medicine. Aconitine is also known to be a highly toxic diterpenoid alkaloid with arrhythmogenic effects. In the present study, we have characterized the properties of arrhythmic cytotoxicity and explored the possible mechanisms of aconitine-induced cardiomyocytes. Results show that aconitine induces significant abnormity in the spontaneous beating rate, amplitude of spontaneous oscillations and the relative intracellular Ca(2+) concentration. Also, mRNA transcription levels and protein expressions of SR Ca(2+) release channel RyR(2) and sarcolemmal NCX were elevated in aconitine-induced cardiomyocytes. However, co-treatment with ruthenium red (RR), a RyR channel inhibitor, could reverse the aconitine-induced abnormity in intracellular Ca(2+) signals. These results demonstrate that disruption of intracellular Ca(2+) homeostasis in the cardiac excitation-contraction coupling (EC coupling) is a crucial mechanism of arrhythmic cytotoxicity in aconitine-induced cardiomyocytes. Moreover, certain inhibitors appear to play an important role in the detoxification of aconitine-induced Ca(2+)-dependent arrhythmias.
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Affiliation(s)
- Min Fu
- School of Medicine, Tsinghua University, Beijing, PR China
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Shaikh SR, Edidin M. Immunosuppressive effects of polyunsaturated fatty acids on antigen presentation by human leukocyte antigen class I molecules. J Lipid Res 2007; 48:127-38. [PMID: 17074926 DOI: 10.1194/jlr.m600365-jlr200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Dietary supplementation with polyunsaturated fatty acids (PUFAs) has immunosuppressive effects; however, the molecular targets of PUFAs and their mode of action remain unclear. One possible target is antigen presentation to T cells through the human leukocyte antigen (HLA) class I pathway. Here we show that incorporation of PUFAs lowers target cell susceptibility to lysis by effector T cells. Treatment of B lymphoblast targets with the omega-6 PUFA arachidonic acid (AA) or omega-3 docosahexaenoic acid lowered their susceptibility to lysis by alloreactive CD8+ T cells by approximately 20-25%. HLA class I surface levels and their rate of endoplasmic reticulum (ER)-Golgi traffic were also reduced by PUFA treatment. Calibration experiments showed that the approximately 15% reduction in surface HLA I was not sufficient to completely account for the decreased lysis. However, PUFAs significantly lowered antigen-presenting cell-T cell conjugate formation, by approximately 30-40%. Taken together, our data show for the first time that an omega-6 and an omega-3 PUFA affect the HLA class I pathway of B lymphoblasts. Our findings suggest that elimination of self- and pathogen-derived peptides by effectors may be compromised by dietary PUFA supplementation. In addition, PUFA-mediated changes in ER-Golgi trafficking point to a new area of PUFA modulation of immune responses.
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Affiliation(s)
- Saame Raza Shaikh
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
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Huang YS, Wang SM, Hsu KL, Tseng YZ, Wu JC. Mechanism of oleic acid-induced myofibril disassembly in rat cardiomyocytes. J Cell Biochem 2007; 102:638-49. [PMID: 17428005 DOI: 10.1002/jcb.21317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This study investigated the mechanism of oleic acid (OA)-induced disassembly of myofibrils in cardiomyocytes. OA treatment disrupted myofibrils, as revealed by the disorganization of several sarcomeric proteins. Since focal adhesions (FAs) are implicated in myofibril assembly, we examined structural changes in FAs after OA treatment. Immunofluorescence studies with antibodies against FA proteins (vinculin, integrin beta1D, and paxillin) showed that FAs and costameres disintegrated or disappeared after OA treatment and that the changes in FA proteins occurred prior to myofibril disassembly. The effects of OA on FAs and myofibrils were reversed after removal of OA. OA decreased expression of integrin beta1D, paxillin, vinculin, and actin, and induced tyrosine dephosphorylation of FA kinase (FAK) and paxillin. These effects were blocked by pretreatment with sodium orthovanadate, a protein tyrosine phosphatase (PTP) inhibitor. This inhibitor also prevented OA-induced myofibril disassembly, indicating the involvement of PTP in myofibril disassembly. Furthermore, OA increased protein levels of PTP-PEST. The upregulation of this phosphatase correlated with the tyrosine dephosphorylation of paxillin and FAK, which are targets for PTP-PEST. In addition, OA decreased RhoA activity and the phosphorylation of cofilin, a downstream target of RhoA. Cofilin dephosphorylation increased its actin-severing activity and led to the depolymerization of F-actin, which might provide another potential mechanism for OA-induced myofibril disassembly.
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Affiliation(s)
- Yuahn-Sieh Huang
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
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Földes G, Vajda S, Lakó-Futó Z, Sármán B, Skoumal R, Ilves M, deChâtel R, Karádi I, Tóth M, Ruskoaho H, Leprán I. Distinct modulation of angiotensin II-induced early left ventricular hypertrophic gene programming by dietary fat type. J Lipid Res 2006; 47:1219-26. [PMID: 16569909 DOI: 10.1194/jlr.m500550-jlr200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Long-term dietary fatty acid intake alters the development of left ventricular hypertrophy, but the linking signaling pathways are unclear. We studied the role and underlying signaling mechanisms of dietary fat intake in the early phase of the hypertrophic process. Rats assigned for 4 weeks of high-oil, high-fat, or standard diet were subjected to angiotensin II (Ang II; 33 microg/kg/h, subcutaneous) or vehicle infusion for 24 h. The Ang II-induced increase in left ventricular mRNA levels of hypertrophy-associated genes was higher in rats fed the high-oil diet compared with the standard diet. Western blotting revealed that, in parallel with changes in gene expression, the high-oil diet increased c-Jun N-terminal kinase phosphorylation (P < 0.001). Ang II increased p38 mitogen-activated protein kinase (MAPK) phosphorylation in rats fed the high-fat diet (3-fold; P < 0.01). The increase in transcription factor activator protein-1 (AP-1) DNA binding activity in response to Ang II was higher in rats fed the high-oil diet compared with those fed the standard diet (P < 0.001). Ang II downregulated inducible nitric oxide synthase mRNA levels in fatty acid-supplemented groups compared with the standard diet group. These results show that dietary fat type modulates the early activation of hypertrophic genes in pressure-overloaded myocardium involving the distinct activation of AP-1 and MAPK signal transduction pathways.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Blotting, Northern
- Blotting, Western
- Dietary Fats/administration & dosage
- Dietary Fats/pharmacology
- Electrophoretic Mobility Shift Assay
- Gene Expression/drug effects
- Heart Ventricles/drug effects
- Heart Ventricles/metabolism
- Heart Ventricles/pathology
- Hypertrophy, Left Ventricular/blood
- Hypertrophy, Left Ventricular/chemically induced
- Hypertrophy, Left Ventricular/genetics
- JNK Mitogen-Activated Protein Kinases/metabolism
- Lipids/blood
- Male
- Mitogen-Activated Protein Kinases/metabolism
- Models, Biological
- Nitric Oxide Synthase Type II/genetics
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Random Allocation
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1/genetics
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Affiliation(s)
- Gábor Földes
- First Department of Medicine, Semmelweis University, Budapest, Hungary
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Jain M, Liao R, Miller TA, LeBrasseur NK, Sawyer DB. Mechanisms in the pathogenesis of diabetic cardiomyopathy. ACTA ACUST UNITED AC 2003. [DOI: 10.1097/00060793-200308000-00004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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