1
|
Shi P, Meng R, Xu J, Zhang Q, Ye G, Yan X, Liao K. Fatty acid translocase (FAT/CD36) in silver pomfret (Pampus argenteus): Molecular cloning and functional characterization. Comp Biochem Physiol B Biochem Mol Biol 2024; 270:110926. [PMID: 38036286 DOI: 10.1016/j.cbpb.2023.110926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
Understanding the mechanisms of lipid transport and metabolism in fish is crucial to enhance dietary lipid utilization. Here, fatty acid translocase (CD36) gene was characterized in silver pomfret (Pampus argenteus). The open reading frame of silver pomfret cd36 gene was 1395 bp, encoding 464 amino acids. The silver pomfret CD36 protein contained typical transmembrane regions and N-glycosylation modification sites, and was localized to the cytomembrane. The cd36 gene was ubiquitously expressed in all tested tissues, with the highest expression observed in brain tissue. In vivo, both fasting and short-term high-fat feeding could increase cd36 expression in intestinal tissue. In vitro, cd36 expression was induced by palmitic acid, oleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid treatment in intestinal tissue. Furthermore, dual-luciferase reporter assay results indicated that peroxisome proliferator-activated receptor gamma (PPARγ) could enhance cd36 promoter activity, and the co-expression of cd36 and pparγ was observed in EPA-incubated intestine, suggesting that EPA may regulate the expression of cd36 via PPARγ to maintain the homeostasis of intestinal lipid metabolism in silver pomfret. These results highlighted the crucial role of CD36 in silver pomfret, and suggested that the cd36 expression may be regulated by PPARγ. This study could contribute to a greater understanding of lipid metabolism and the development of effective strategies for nutrient requirements in fish.
Collapse
Affiliation(s)
- Peng Shi
- School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Ran Meng
- Ningbo Academy of Oceanology and Fishery, Ningbo 315012, China
| | - Jilin Xu
- School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Qian Zhang
- School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Guochao Ye
- School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Xiaojun Yan
- School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Kai Liao
- School of Marine Sciences, Ningbo University, Ningbo 315211, China.
| |
Collapse
|
2
|
Tian J, Liu W, Gao W, Wu F, Yu L, Lu X, Yang CG, Jiang M, Wen H. Molecular cloning and gene/protein expression of FAT/CD36 from grass carp (Ctenopharyngodon idella) and the regulation of its expression by dietary energy. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:875-888. [PMID: 28101704 DOI: 10.1007/s10695-017-0342-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
Fatty acid translocase/cluster of differentiation 36 (FAT/CD36) functions as a membrane long-chain fatty acid transporter in various tissues in land animals. Not much is known about the CD36 molecule in teleost fish. Therefore, we studied CD36 in grass carp (Ctenopharyngodon idella, ciCD36). The full-length complementary DNA sequence of ciCD36 was 1976 bp, with an ORF of 468 amino acids, which had high sequence similarity to the CD36 of common carp. The messenger RNA (mRNA) expression of ciCD36 was high in the intestine, heart, liver, visceral tissue, and brain, but absent in the kidney. The protein expression of ciCD36 was high in the brain, intestine, liver, heart, muscle, eye, visceral tissue, gonad, and gill, but not in the kidney. Four groups of grass carp (16 tanks) were fed three times daily to satiation with 17.2 kJ gross energy/g diet (control, CON), 19.4 kJ gross energy/g diet (more energy supplied by proteins, HP), 19.9 kJ gross energy/g diet (more energy supplied by fat, HF), and 19.1 kJ gross energy/g diet (more energy supplied by carbohydrate, HC) for 11 weeks, respectively. At the end of the feeding experiment, the fish were fasted for 48 h, and the brain, heart, intestine, and liver were sampled and designated as the 0-h samples. The fish were then fed a single meal of the above four diets, and these tissues were collected at 8- and 24-h intervals after refeeding to analyze ciCD36 mRNA and protein expression levels. The results showed that at the transcriptional and translational levels, ciCD36 expression was significantly affected by refeeding time and the different diets (P < 0.05), and the regulation of its transcription in different tissues varied. At the translational level, the protein expression levels decreased in the CON and HC groups, and increased in the HP and HF groups after refeeding. The results indicated that ciCD36 has a modulatory role in the adaptation to dietary high energy in grass carp. Translational regulation might be responsible for the observed variations in ciCD36 expression.
Collapse
Affiliation(s)
- Juan Tian
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
- Freshwater Aquaculture Collaborative Innovative Centre of Hubei Province, Wuhan, 430070, China
| | - Wei Liu
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Weihua Gao
- Department of Fisheries, College of Animal Science, Yangtze University, Jingzhou, 434024, China
| | - Fan Wu
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Lijuan Yu
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Xing Lu
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Chang-Geng Yang
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
| | - Ming Jiang
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China
- Freshwater Aquaculture Collaborative Innovative Centre of Hubei Province, Wuhan, 430070, China
| | - Hua Wen
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, No.8, Wudayuan 1st Road, Donghu Hi-tech Development Zone, Wuhan, 430223, China.
| |
Collapse
|
3
|
Akhmedov AT, Rybin V, Marín-García J. Mitochondrial oxidative metabolism and uncoupling proteins in the failing heart. Heart Fail Rev 2015; 20:227-49. [PMID: 25192828 DOI: 10.1007/s10741-014-9457-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Despite significant progress in cardiovascular medicine, myocardial ischemia and infarction, progressing eventually to the final end point heart failure (HF), remain the leading cause of morbidity and mortality in the USA. HF is a complex syndrome that results from any structural or functional impairment in ventricular filling or blood ejection. Ultimately, the heart's inability to supply the body's tissues with enough blood may lead to death. Mechanistically, the hallmarks of the failing heart include abnormal energy metabolism, increased production of reactive oxygen species (ROS) and defects in excitation-contraction coupling. HF is a highly dynamic pathological process, and observed alterations in cardiac metabolism and function depend on the disease progression. In the early stages, cardiac remodeling characterized by normal or slightly increased fatty acid (FA) oxidation plays a compensatory, cardioprotective role. However, upon progression of HF, FA oxidation and mitochondrial oxidative activity are decreased, resulting in a significant drop in cardiac ATP levels. In HF, as a compensatory response to decreased oxidative metabolism, glucose uptake and glycolysis are upregulated, but this upregulation is not sufficient to compensate for a drop in ATP production. Elevated mitochondrial ROS generation and ROS-mediated damage, when they overwhelm the cellular antioxidant defense system, induce heart injury and contribute to the progression of HF. Mitochondrial uncoupling proteins (UCPs), which promote proton leak across the inner mitochondrial membrane, have emerged as essential regulators of mitochondrial membrane potential, respiratory activity and ROS generation. Although the physiological role of UCP2 and UCP3, expressed in the heart, has not been clearly established, increasing evidence suggests that these proteins by promoting mild uncoupling could reduce mitochondrial ROS generation and cardiomyocyte apoptosis and ameliorate thereby myocardial function. Further investigation on the alterations in cardiac UCP activity and regulation will advance our understanding of their physiological roles in the healthy and diseased heart and also may facilitate the development of novel and more efficient therapies.
Collapse
Affiliation(s)
- Alexander T Akhmedov
- The Molecular Cardiology and Neuromuscular Institute, 75 Raritan Avenue, Highland Park, NJ, 08904, USA
| | | | | |
Collapse
|
4
|
Vermillion KL, Anderson KJ, Hampton M, Andrews MT. Gene expression changes controlling distinct adaptations in the heart and skeletal muscle of a hibernating mammal. Physiol Genomics 2015; 47:58-74. [PMID: 25572546 PMCID: PMC4346737 DOI: 10.1152/physiolgenomics.00108.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/05/2015] [Indexed: 01/12/2023] Open
Abstract
Throughout the hibernation season, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) experiences extreme fluctuations in heart rate, metabolism, oxygen consumption, and body temperature, along with prolonged fasting and immobility. These conditions necessitate different functional requirements for the heart, which maintains contractile function throughout hibernation, and the skeletal muscle, which remains largely inactive. The adaptations used to maintain these contractile organs under such variable conditions serves as a natural model to study a variety of medically relevant conditions including heart failure and disuse atrophy. To better understand how two different muscle tissues maintain function throughout the extreme fluctuations of hibernation we performed Illumina HiSeq 2000 sequencing of cDNAs to compare the transcriptome of heart and skeletal muscle across the circannual cycle. This analysis resulted in the identification of 1,076 and 1,466 differentially expressed genes in heart and skeletal muscle, respectively. In both heart and skeletal muscle we identified a distinct cold-tolerant mechanism utilizing peroxisomal metabolism to make use of elevated levels of unsaturated depot fats. The skeletal muscle transcriptome also shows an early increase in oxidative capacity necessary for the altered fuel utilization and increased oxygen demand of shivering. Expression of the fetal gene expression profile is used to maintain cardiac tissue, either through increasing myocyte size or proliferation of resident cardiomyocytes, while skeletal muscle function and mass are protected through transcriptional regulation of pathways involved in protein turnover. This study provides insight into how two functionally distinct muscles maintain function under the extreme conditions of mammalian hibernation.
Collapse
Affiliation(s)
- Katie L Vermillion
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota; and
| | - Kyle J Anderson
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota; and
| | - Marshall Hampton
- Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth, Minnesota
| | - Matthew T Andrews
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota; and
| |
Collapse
|
5
|
Kok BPC, Dyck JRB, Harris TE, Brindley DN. Differential regulation of the expressions of the PGC-1α splice variants, lipins, and PPARα in heart compared to liver. J Lipid Res 2013; 54:1662-1677. [PMID: 23505321 DOI: 10.1194/jlr.m036624] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Peroxisome proliferator-activated receptor α (PPARα) and PPARγ coactivator 1α (PGC-1α) are crucial transcriptional regulators for genes involved in FA oxidation. Lipin-1 is essential for this increased capacity for β-oxidation in fasted livers, and it is also a phosphatidate phosphatase involved in triacylglycerol and phospholipid synthesis. Little is known about the regulation of these proteins in the heart during fasting, where there is increased FA esterification and oxidation. Lipin-1, lipin-2, lipin-3, carnitine palmitoyltransferase-1b (Cpt1b), and PGC-1α-b mRNA were increased by glucocorticoids and cAMP in neonatal rat cardiomyocytes. However, Cpt1b upregulation was caused by increased PPARα activation rather than expression. By contrast, the effects of PPARα in fasted livers are mediated through increased expression. During fasting, the expressions of PGC-1α-b and PGC-1α-c are increased in mouse hearts, and this is explained by increased cAMP-dependent signaling. By contrast, PGC-1α-a expression is increased in liver. Contrary to our expectations, lipin-1 expression was decreased and lipin-2 remained unchanged in hearts compared with increases in fasted livers. Our results identify novel differences in the regulation of lipins, PPARα, and PGC-1α splice variants during fasting in heart versus liver, even though the ultimate outcome in both tissues is to increase FA turnover and oxidation.
Collapse
Affiliation(s)
- Bernard P C Kok
- Signal Transduction Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Jason R B Dyck
- Department of Biochemistry, and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada; Department of Pediatrics, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - David N Brindley
- Signal Transduction Research Group, University of Alberta, Edmonton, Alberta, Canada; Department of Pediatrics, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
| |
Collapse
|
6
|
Georgiadi A, Boekschoten MV, Müller M, Kersten S. Detailed transcriptomics analysis of the effect of dietary fatty acids on gene expression in the heart. Physiol Genomics 2012; 44:352-61. [PMID: 22274564 DOI: 10.1152/physiolgenomics.00115.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Fatty acids comprise the primary energy source for the heart and are mainly taken up via hydrolysis of circulating triglyceride-rich lipoproteins. While most of the fatty acids entering the cardiomyocyte are oxidized, a small portion is involved in altering gene transcription to modulate cardiometabolic functions. So far, no in vivo model has been developed enabling study of the transcriptional effects of specific fatty acids in the intact heart. In the present study, mice were given a single oral dose of synthetic triglycerides composed of one single fatty acid. Hearts were collected 6 h thereafter and used for whole genome gene expression profiling. Experiments were conducted in wild-type and peroxisome proliferator-activated receptor (PPAR)α-/- mice to allow exploration of the specific contribution of PPARα. It was found that: 1) C18:3 had the most pronounced effect on cardiac gene expression. 2) The largest similarity in gene regulation was observed between C18:2 and C18:3. Large similarity was also observed between PPARα agonist Wy14643 and C22:6. 3) Many genes were regulated by one particular treatment only. Genes regulated by one particular treatment showed large functional divergence. 4) The majority of genes responding to fatty acid treatment were regulated in a PPARα-dependent manner, emphasizing the importance of PPARα in mediating transcriptional regulation by fatty acids in the heart. 5) Several genes were robustly regulated by all or many of the fatty acids studied, mostly representing well-described targets of PPARs (e.g., Acot1, Angptl4, Ucp3) but also including Zbtb16/PLZF, a transcription factor crucial for natural killer T cell function. 6) Deletion and activation of PPARα had a major effect on expression of numerous genes involved in metabolism and immunity. Our analysis demonstrates the marked impact of dietary fatty acids on gene regulation in the heart via PPARα.
Collapse
Affiliation(s)
- Anastasia Georgiadi
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, the Netherlands
| | | | | | | |
Collapse
|
7
|
Synak M, Zarzeczny R, Górecka M, Langfort J, Kaciuba-Uściłko H, Żernicka E. Fasting increases palmitic acid incorporation into rat hind-limb intramuscular acylglycerols while short-term cold exposure has no effect. ACTA ACUST UNITED AC 2011; 98:359-66. [DOI: 10.1556/aphysiol.98.2011.3.13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
8
|
Holloway CJ, Cochlin LE, Emmanuel Y, Murray A, Codreanu I, Edwards LM, Szmigielski C, Tyler DJ, Knight NS, Saxby BK, Lambert B, Thompson C, Neubauer S, Clarke K. A high-fat diet impairs cardiac high-energy phosphate metabolism and cognitive function in healthy human subjects. Am J Clin Nutr 2011; 93:748-55. [PMID: 21270386 DOI: 10.3945/ajcn.110.002758] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND High-fat, low-carbohydrate diets are widely used for weight reduction, but they may also have detrimental effects via increased circulating free fatty acid concentrations. OBJECTIVE We tested whether raising plasma free fatty acids by using a high-fat, low-carbohydrate diet results in alterations in heart and brain in healthy subjects. DESIGN Men (n = 16) aged 22 ± 1 y (mean ± SE) were randomly assigned to 5 d of a high-fat, low-carbohydrate diet containing 75 ± 1% of calorie intake through fat consumption or to an isocaloric standard diet providing 23 ± 1% of calorie intake as fat. In a crossover design, subjects undertook the alternate diet after a 2-wk washout period, with results compared after the diet periods. Cardiac (31)P magnetic resonance (MR) spectroscopy and MR imaging, echocardiography, and computerized cognitive tests were used to assess cardiac phosphocreatine (PCr)/ATP, cardiac function, and cognitive function, respectively. RESULTS Compared with the standard diet, subjects who consumed the high-fat, low-carbohydrate diet had 44% higher plasma free fatty acids (P < 0.05), 9% lower cardiac PCr/ATP (P < 0.01), and no change in cardiac function. Cognitive tests showed impaired attention (P < 0.01), speed (P < 0.001), and mood (P < 0.01) after the high-fat, low-carbohydrate diet. CONCLUSION Raising plasma free fatty acids decreased myocardial PCr/ATP and reduced cognition, which suggests that a high-fat diet is detrimental to heart and brain in healthy subjects.
Collapse
Affiliation(s)
- Cameron J Holloway
- Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Wang CM, Almsherqi ZA, McLachlan CS, Matthews S, Ramachandran M, Tay SK, Deng Y. Acute starvation in C57BL/6J mice increases myocardial UCP2 and UCP3 protein expression levels and decreases mitochondrial bio-energetic function. Stress 2011; 14:66-72. [PMID: 20932228 DOI: 10.3109/10253890.2010.506931] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Associations between uncoupling protein (UCP) expression and functional changes in myocardial mitochondrial bio-energetics have not been well studied during periods of starvation stress. Our aim was to study the effects of acute starvation, for 24 or 48 h, on combined cardiac mitochondrial function and UCP expression in mice. Isolated heart mitochondria from female mice starved for 48 h compared to that from mice fed revealed a significantly (p < 0.05) decreased adenosine diphosphate-to-oxygen ratio, a significantly increased proton leak and an increased GTP inhibition on palmitic acid-induced state 4 oxygen consumption (p < 0.05). These bio-energetic functional changes were associated with increases in mitochondrial UCP2 and UCP3 protein expression. In conclusion, our findings suggest that increased UCP2 and UCP3 levels may contribute to decreased myocardial mitochondrial bio-energetic function due to starvation.
Collapse
Affiliation(s)
- Chun-Ming Wang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | | | | | |
Collapse
|
10
|
Glatz JFC, Luiken JJFP, Bonen A. Membrane Fatty Acid Transporters as Regulators of Lipid Metabolism: Implications for Metabolic Disease. Physiol Rev 2010; 90:367-417. [DOI: 10.1152/physrev.00003.2009] [Citation(s) in RCA: 515] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Long-chain fatty acids and lipids serve a wide variety of functions in mammalian homeostasis, particularly in the formation and dynamic properties of biological membranes and as fuels for energy production in tissues such as heart and skeletal muscle. On the other hand, long-chain fatty acid metabolites may exert toxic effects on cellular functions and cause cell injury. Therefore, fatty acid uptake into the cell and intracellular handling need to be carefully controlled. In the last few years, our knowledge of the regulation of cellular fatty acid uptake has dramatically increased. Notably, fatty acid uptake was found to occur by a mechanism that resembles that of cellular glucose uptake. Thus, following an acute stimulus, particularly insulin or muscle contraction, specific fatty acid transporters translocate from intracellular stores to the plasma membrane to facilitate fatty acid uptake, just as these same stimuli recruit glucose transporters to increase glucose uptake. This regulatory mechanism is important to clear lipids from the circulation postprandially and to rapidly facilitate substrate provision when the metabolic demands of heart and muscle are increased by contractile activity. Studies in both humans and animal models have implicated fatty acid transporters in the pathogenesis of diseases such as the progression of obesity to insulin resistance and type 2 diabetes. As a result, membrane fatty acid transporters are now being regarded as a promising therapeutic target to redirect lipid fluxes in the body in an organ-specific fashion.
Collapse
Affiliation(s)
- Jan F. C. Glatz
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Joost J. F. P. Luiken
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Arend Bonen
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| |
Collapse
|
11
|
High-fat feeding in cardiomyocyte-restricted PPARdelta knockout mice leads to cardiac overexpression of lipid metabolic genes but fails to rescue cardiac phenotypes. J Mol Cell Cardiol 2009; 47:536-43. [PMID: 19595695 DOI: 10.1016/j.yjmcc.2009.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/01/2009] [Accepted: 07/01/2009] [Indexed: 11/21/2022]
Abstract
Peroxisome proliferator-activated receptor delta (PPARdelta) is an essential determinant of basal myocardial fatty acid oxidation (FAO) and bioenergetics. We wished to determine whether increased lipid loading affects the PPARdelta deficient heart in transcriptional regulation of FAO and in the development of cardiac pathology. Cardiomyocyte-restricted PPARdelta knockout (CR-PPARdelta(-/-)) and control (alpha-MyHC-Cre) mice were subjected to 48 h of fasting and to a long-term maintenance on a (28 weeks) high-fat diet (HFD). The expression of key FAO proteins in heart was examined. Serum lipid profiles, cardiac pathology, and changes of various transduction signaling pathways were also examined. Mice subjected to fasting exhibited upregulated transcript expression of FAO genes in the CR-PPARdelta(-/-) hearts. Moreover, long-term HFD in CR-PPARdelta(-/-) mice induced a strikingly greater transcriptional response. After HFD, genes encoding key FAO enzymes were expressed remarkably more in CR-PPARdelta(-/-) hearts than in those of control mice. Despite the marked rise of FAO gene expression, corresponding protein expression remained low in the CR-PPARdelta(-/-) heart, accompanied by abnormalities in sarcomere structures and mitochondria that were similar to those of CR-PPARdelta(-/-) hearts with regular chow feeding. The CR-PPARdelta(-/-) mice displayed increased expression of PPARgamma co-activator-1alpha (PGC-1alpha) and PPARalpha in the heart with deactivated Akt and p42/44 MAPK signaling in response to HFD. We conclude that PPARdelta is an essential determinant of myocardial FAO. Increased lipid intake activates cardiac expression of FAO genes via PPARalpha/PGC-1alpha pathway, albeit it is not sufficient to improve cardiac pathology due to PPARdelta deficiency.
Collapse
|
12
|
Shearer J, Severson DL, Su L, Belardinelli L, Dhalla AK. Partial A1 adenosine receptor agonist regulates cardiac substrate utilization in insulin-resistant rats in vivo. J Pharmacol Exp Ther 2008; 328:306-11. [PMID: 18952888 DOI: 10.1124/jpet.108.143594] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Reducing the availability and uptake of fatty acids is a plausible pharmaceutical target to ameliorate glucose intolerance and insulin resistance. CVT-3619 [2-{6-[((1R,2R)-2-hydroxycyclopentyl) amino]purin-9-yl(4S,5S,2R,3R)-5-[(2-fluorophenylthio)methyl]oxolane-3,4-diol] is a partial A(1) adenosine receptor agonist with antilipolytic properties. Aims of the present study were to examine the acute effects of CVT-3619 on whole-body and cardiac glucose and fatty acid kinetics in vivo in normal and diet-induced insulin-resistant rats. Male Sprague-Dawley rats were fed either a chow (CH) or high-fat (HF) diet for 4 weeks. Catheters were then chronically implanted in the carotid artery and jugular vein for sampling and infusions, respectively. After 5 days of recovery, fasted animals (10 h) received either saline or CVT-3619 (0.4 mg/kg bolus + 1 mg/kg/h). Indices of glucose and fatty acid utilization were obtained by the administration of 2-deoxy[(14)C]glucose and [9,10-(3)H]-(R)-2-bromopalmitate. HF feeding resulted in elevated, fasting insulin and free fatty acid (FFA) levels compared with CH. CVT-3619 caused a 64 and 86% reduction of FFA and insulin in HF (p < 0.05) but less (N.S.) in CH diet-fed animals. In HF diet-fed rats, CVT-3619 increased whole-body glucose clearance with no change in fatty acid kinetics. Likewise, analysis of cardiac tissue metabolism showed that CVT-3619 caused an increased glucose but not fatty acid clearance in HF-fed animals. Results show that the acute administration of CVT-3619 lowers circulating fatty acid levels, leading to improved whole-body and cardiac glucose clearance in a model of diet-induced insulin resistance. As such, CVT-3619 may be a treatment option for the restoration of substrate balance in the insulin-resistant heart.
Collapse
Affiliation(s)
- Jane Shearer
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada.
| | | | | | | | | |
Collapse
|
13
|
Ekladous D, Mehdi MZ, Costa M, Srivastava AK, Chiasson JL, Coderre L. TISSUE- AND FIBRE-SPECIFIC MODIFICATIONS OF INSULIN-SIGNALLING MOLECULES IN CARDIAC AND SKELETAL MUSCLE OF DIABETIC RATS. Clin Exp Pharmacol Physiol 2008; 35:971-8. [DOI: 10.1111/j.1440-1681.2008.04944.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
14
|
Nabben M, Hoeks J. Mitochondrial uncoupling protein 3 and its role in cardiac- and skeletal muscle metabolism. Physiol Behav 2007; 94:259-69. [PMID: 18191161 DOI: 10.1016/j.physbeh.2007.11.039] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 11/22/2007] [Accepted: 11/23/2007] [Indexed: 11/20/2022]
Abstract
Uncoupling protein 3 (UCP3), is primarily expressed in skeletal muscle mitochondria and has been suggested to be involved in mediating energy expenditure via uncoupling, hereby dissipating the mitochondrial proton gradient necessary for adenosine triphosphate (ATP) synthesis. Although some studies support a role for UCP3 in energy metabolism, other studies pointed towards a function in fatty acid metabolism. Thus, the protein is up regulated or high when fatty acid supply to the mitochondria exceeds the capacity to oxidize fatty acids and down regulated or low when oxidative capacity is high or improved. Irrespective of the exact operating mechanism, UCP3 seems to protect mitochondria against lipid-induced oxidative stress, which makes this protein a potential player in the development of type 2 diabetes mellitus. Next to skeletal muscle, UCP3 is also expressed in cardiac muscle where its role is relatively unexplored. Interestingly, energy deficiency in cardiac muscle is associated to heart failure and UCP3 might contribute to this energy deficiency. It has been suggested that UCP3 decreases energy status via uncoupling of mitochondrial respiration, but the available data does not provide a unified answer. In fact, the results obtained regarding cardiac UCP3 are very similar as in skeletal muscle, implying that its physiological function can be extrapolated. Therefore, cardiac UCP3 can just as well serve to protect the heart against lipid-induced oxidative stress, similar to the function described for skeletal muscle UCP3. The present review will deal with the available literature on both skeletal muscle- and cardiac UCP3 to elucidate its physiological function in these tissues.
Collapse
Affiliation(s)
- Miranda Nabben
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
| | | |
Collapse
|
15
|
Le Gouill E, Jimenez M, Binnert C, Jayet PY, Thalmann S, Nicod P, Scherrer U, Vollenweider P. Endothelial nitric oxide synthase (eNOS) knockout mice have defective mitochondrial beta-oxidation. Diabetes 2007; 56:2690-6. [PMID: 17682093 DOI: 10.2337/db06-1228] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Recent observations indicate that the delivery of nitric oxide by endothelial nitric oxide synthase (eNOS) is not only critical for metabolic homeostasis, but could also be important for mitochondrial biogenesis, a key organelle for free fatty acid (FFA) oxidation and energy production. Because mice deficient for the gene of eNOS (eNOS(-/-)) have increased triglycerides and FFA levels, in addition to hypertension and insulin resistance, we hypothesized that these knockout mice may have decreased energy expenditure and defective beta-oxidation. RESEARCH DESIGN AND METHODS Several markers of mitochondrial activity were assessed in C57BL/6J wild-type or eNOS(-/-) mice including the energy expenditure and oxygen consumption by indirect calorimetry, in vitro beta-oxidation in isolated mitochondria from skeletal muscle, and expression of genes involved in fatty acid oxidation. RESULTS eNOS(-/-) mice had markedly lower energy expenditure (-10%, P < 0.05) and oxygen consumption (-15%, P < 0.05) than control mice. This was associated with a roughly 30% decrease of the mitochondria content (P < 0.05) and, most importantly, with mitochondrial dysfunction, as evidenced by a markedly lower beta-oxidation of subsarcolemmal mitochondria in skeletal muscle (-30%, P < 0.05). Finally, impaired mitochondrial beta-oxidation was associated with a significant increase of the intramyocellular lipid content (30%, P < 0.05) in gastrocnemius muscle. CONCLUSIONS These data indicate that elevated FFA and triglyceride in eNOS(-/-) mice result in defective mitochondrial beta-oxidation in muscle cells.
Collapse
Affiliation(s)
- Eric Le Gouill
- Department of Cellular Biology and Morphology, University of Lausanne, Lausanne, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
16
|
de Lange P, Farina P, Moreno M, Ragni M, Lombardi A, Silvestri E, Burrone L, Lanni A, Goglia F. Sequential changes in the signal transduction responses of skeletal muscle following food deprivation. FASEB J 2006; 20:2579-81. [PMID: 17065218 DOI: 10.1096/fj.06-6025fje] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Coping with reduced energy sources entails drastic morphological and functional changes in skeletal muscle, but the sequence of events required classification. We found that gastrocnemius muscle from food-deprived rats shows acute rises in peroxisome proliferator activated receptor (PPAR) gamma coactivator (PGC) -1alpha/PPAR delta nuclear protein and myosin heavy chain (MHC) Ib protein, while type I fibers accumulate and the muscle tissue appears redder. AMP levels, phosphorylation of both AMP-activated protein kinase (AMPK) and its downstream target acetyl coenzyme A carboxylase (ACC) are induced within 6 h. Rapidly increased MyoD mRNA levels are followed by an increase in uncoupling protein (UCP) 3 (UCP3) transcription. Increased serum fatty acid levels coincide with increases in mitochondrial UCP3 protein levels and fatty acid oxidation. Accompanying this is a decrease in AMPK phosphorylation, reversible upon nicotinic acid treatment, indicating that fatty acids may modulate this kinase's activity after the metabolic challenges posed by food deprivation.
Collapse
Affiliation(s)
- Pieter de Lange
- Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100, Caserta, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Barger JL, Barnes BM, Boyer BB. Regulation of UCP1 and UCP3 in arctic ground squirrels and relation with mitochondrial proton leak. J Appl Physiol (1985) 2006; 101:339-47. [PMID: 16782837 DOI: 10.1152/japplphysiol.01260.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uncoupling protein (UCP) 1 (UCP1) catalyzes a proton leak in brown adipose tissue (BAT) mitochondria that results in nonshivering thermogenesis (NST), but the extent to which UCP homologs mediate NST in other tissues is controversial. To clarify the role of UCP3 in mediating NST in a hibernating species, we measured Ucp3 expression in skeletal muscle of arctic ground squirrels in one of three activity states (not hibernating, not hibernating and fasted for 48 h, or hibernating) and housed at 5°C or −10°C. We then compared Ucp3 mRNA levels in skeletal muscle with Ucp1 mRNA and UCP1 protein levels in BAT in the same animals. Ucp1 mRNA and UCP1 protein levels were increased on cold exposure and decreased with fasting, with the highest UCP1 levels in thermogenic hibernators. In contrast, Ucp3 mRNA levels were not affected by temperature but were increased 10-fold during fasting and >3-fold during hibernation. UCP3 protein levels were increased nearly fivefold in skeletal muscle mitochondria isolated from fasted squirrels compared with nonhibernators, but proton leak kinetics in the presence of BSA were unchanged. Proton leak in BAT mitochondria also did not differ between fed and fasted animals but did show classical inhibition by the purine nucleotide GDP. Levels of nonesterified fatty acids were highest during hibernation, and tissue temperatures during hibernation were related to Ucp1, but not Ucp3, expression. Taken together, these results do not support a role for UCP3 as a physiologically relevant mediator of NST in muscle.
Collapse
Affiliation(s)
- Jamie L Barger
- 311 Irving I Bldg., Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA
| | | | | |
Collapse
|
18
|
Tsintzas K, Jewell K, Kamran M, Laithwaite D, Boonsong T, Littlewood J, Macdonald I, Bennett A. Differential regulation of metabolic genes in skeletal muscle during starvation and refeeding in humans. J Physiol 2006; 575:291-303. [PMID: 16763003 PMCID: PMC1819428 DOI: 10.1113/jphysiol.2006.109892] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This study investigated the molecular alterations underlying the physiological adaptations to starvation and refeeding in human skeletal muscle. Forty-eight hours' starvation reduced whole-body insulin sensitivity by 42% and produced marked changes in expression of key carbohydrate (CHO) regulatory genes and proteins: SREBP1c and hexokinase II (HKII) were downregulated 2.5- and 5-fold, respectively, whereas the pyruvate dehydrogenase kinase 4 (PDK4) was upregulated 4-fold. These responses were not dependent on the phosphorylation status of Akt and FOXO1. On the other hand, starvation and the concomitant increase in circulating free fatty acids did not upregulate the expression of transcription factors and genes involved in fat metabolism. Twenty-four hours' refeeding with a CHO-rich diet completely reversed the changes in PDK4, HKII and SREBP1c expression in human skeletal muscle but failed to fully restore whole-body insulin sensitivity. Thus, during starvation in healthy humans, unlike rodents, regulation of fat metabolism does not require an adaptive response at transcriptional level, but adaptive changes in gene expression are required to switch off oxidative glucose disposal. Lack of effect on key proteins in the insulin-signalling pathway may indicate that changes in intracellular substrate availability/flux may be responsible for these adaptive changes in glucose metabolism. This may represent an important aspect of the molecular basis of the development of insulin resistance in metabolic conditions characterized by energy restriction.
Collapse
Affiliation(s)
- Kostas Tsintzas
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, University of Nottingham, Nottingham NG7 2UH, UK.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Mitchell S, Ota A, Foster W, Zhang B, Fang Z, Patel S, Nelson SF, Horvath S, Wang Y. Distinct gene expression profiles in adult mouse heart following targeted MAP kinase activation. Physiol Genomics 2006; 25:50-9. [PMID: 16368875 DOI: 10.1152/physiolgenomics.00224.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Three major MAP kinase signaling cascades, ERK, p38, and JNK, play significant roles in the development of cardiac hypertrophy and heart failure in response to external stress and neural/hormonal stimuli. To study the specific function of each MAP kinase branch in adult heart, we have generated three transgenic mouse models with cardiac-specific and temporally regulated expression of activated mutants of Ras, MAP kinase kinase (MKK)3, and MKK7, which are selective upstream activators for ERK, p38, and JNK, respectively. Gene expression profiles in transgenic adult hearts were determined using cDNA microarrays at both early (4–7 days) and late (2–4 wk) time points following transgene induction. From this study, we revealed common changes in gene expression among the three models, particularly involving extracellular matrix remodeling. However, distinct expression patterns characteristic for each pathway were also identified in cell signaling, growth, and physiology. In addition, genes with dynamic expression differences between early vs. late stages illustrated primary vs. secondary changes on MAP kinase activation in adult hearts. These results provide an overview to both short-term and long-term effects of MAP kinase activation in heart and support some common as well as unique roles for each MAP kinase cascade in the development of heart failure.
Collapse
Affiliation(s)
- Scherise Mitchell
- Department of Physiology, University of Maryland Baltimore, School of Medicine, Maryland, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
SEKI Y, SATO K, KONO T, AKIBA Y. Cloning and gene expression of hexokinase I and II in the chicken skeletal muscle. Anim Sci J 2005. [DOI: 10.1111/j.1740-0929.2005.00295.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
21
|
Lundby C, Nordsborg N, Kusuhara K, Kristensen KM, Neufer PD, Pilegaard H. Gene expression in human skeletal muscle: alternative normalization method and effect of repeated biopsies. Eur J Appl Physiol 2005; 95:351-60. [PMID: 16151837 DOI: 10.1007/s00421-005-0022-7] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2005] [Indexed: 11/28/2022]
Abstract
The reverse transcriptase-polymerase chain reaction (RT-PCR) method has lately become widely used to determine transcription and mRNA content in rodent and human muscle samples. However, the common use of endogenous controls for correcting for variance in cDNA between samples is not optimal. Specifically, we investigated (1) a new normalization method based on determining the cDNA content by the flourophores PicoGreen and OliGreen, (2) effect of repeated muscle biopsies on mRNA gene expression, and (3) the spatial heterogeneity in mRNA expression across the muscle. Standard curves using oligo standards revealed a high degree of sensitivity and linearity (2.5-45 ng; R2>0.99) with OliGreen reagent, as was the case for OliGreen analyses with standard curves constructed from serial dilutions of representative RT samples (R2 >0.99 for a ten times dilution range of a representative reversed transcribed (RT) sample). Likewise, PicoGreen reagent detected the RNA:DNA hybrid content in RT samples with great sensitivity. Standard curves constructed from both double-stranded lambda DNA (1-10 ng) and from serial dilutions of representative RT samples consistently resulted in linearity with R2 >0.99. The present determination of cDNA content in reversed transcribed human skeletal muscle RNA samples by both PicoGreen and OliGreen analyses suggests that these fluorophores provide a potential alternative normalization procedure for human gene expression studies. In addition, the present study shows that multiple muscle biopsies obtained from the same muscle do not influence the mRNA response induced by an acute exercise bout for any of the genes examined.
Collapse
Affiliation(s)
- Carsten Lundby
- Copenhagen Muscle Research Centre, Rigshospitalet, section 7652, Blegdamsvej 9, 2100, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
22
|
Degens H, de Brouwer KFJ, Gilde AJ, Lindhout M, Willemsen PHM, Janssen BJ, van der Vusse GJ, van Bilsen M. Cardiac fatty acid metabolism is preserved in the compensated hypertrophic rat heart. Basic Res Cardiol 2005; 101:17-26. [PMID: 16136293 DOI: 10.1007/s00395-005-0549-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 08/01/2005] [Accepted: 08/10/2005] [Indexed: 12/12/2022]
Abstract
Cardiac hypertrophy and failure are associated with alterations in cardiac substrate metabolism. It remains to be established, however, whether genomically driven changes in cardiac glucose and fatty acid (FA) metabolism represent a key event of the hypertrophic remodeling process. Accordingly, we investigated metabolic gene expression and substrate metabolism during compensatory hypertrophy, in relation to other cardiac remodeling processes. Thereto, cardiac hypertrophy was induced in rats by supra-renal aortic constriction to various degrees, resulting in increased heart/body weight ratios of 22% (Aob-1), 24% (Aob-2) and 32% (Aob-3) (p < 0.005) after 4 weeks. The unaltered ejection fraction in all groups indicated that the hypertrophy was still compensatory in nature. beta-Myosin Heavy Chain protein and ANF mRNA levels were increased in all groups. Only in Aob-3 rats were SERCA2a mRNA levels markedly reduced. In this group, glycolytic capacity was modestly elevated (+ 25%; p < 0.01). Notwithstanding these phenotypical changes, the expression of genes involved in FA metabolism and FA oxidation rate in cardiac homogenates was completely preserved, irrespective of the degree of hypertrophy. These findings indicate that cardiac FA oxidative capacity is preserved during compensatory hypertrophy, and that a decline in metabolic gene expression does not represent a hallmark of the development of hypertrophy.
Collapse
Affiliation(s)
- Hans Degens
- Dep. of Physiology, Cardiovascular Research Institute Maastricht (CARIM) Maastricht University, 616, 6200 MD Maastricht, the Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Panagia M, Gibbons GF, Radda GK, Clarke K. PPAR-α activation required for decreased glucose uptake and increased susceptibility to injury during ischemia. Am J Physiol Heart Circ Physiol 2005; 288:H2677-83. [PMID: 15665064 DOI: 10.1152/ajpheart.00200.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transcription of key metabolic regulatory enzymes in the heart is altered in the diabetic state, yet little is known of the underlying mechanisms. The aim of this study was to investigate the role of peroxisome proliferator-activated receptor-α (PPAR-α) in modulating cardiac insulin-sensitive glucose transporter (GLUT-4) protein levels in altered metabolic states and to determine the functional consequences by assessing cardiac ischemic tolerance. Wild-type and PPAR-α-null mouse hearts were isolated and perfused 6 wk after streptozotocin administration or after 14 mo on a high-fat diet or after a 24-h fast. Myocardial d-[2-3H]glucose uptake was measured during low-flow ischemia, and differences in GLUT-4 protein levels were quantified using Western blotting. In wild-type mice in all three metabolic states, elevated plasma free fatty acids were associated with lower total cardiac GLUT-4 protein levels and decreased glucose uptake during ischemia, resulting in poor postischemic functional recovery. Although PPAR-α-null mice also had elevated plasma free fatty acids, they had neither decreased cardiac GLUT-4 levels nor decreased glucose uptake during ischemia and, consequently, did not have poor recovery during reperfusion. We conclude that elevated plasma free fatty acids are associated with increased injury during ischemia due to decreased cardiac glucose uptake resulting from lower cardiac GLUT-4 protein levels, the levels of GLUT-4 being regulated, probably indirectly, through PPAR-α activation.
Collapse
Affiliation(s)
- Marcello Panagia
- Univ. Laboratory of Physiology, Univ. of Oxford, Parks Rd., Oxford OX1 3PT, UK
| | | | | | | |
Collapse
|
24
|
Hoeks J, Hesselink MKC, van Bilsen M, Schaart G, van der Vusse GJ, Saris WHM, Schrauwen P. Differential response of UCP3 to medium versus long chain triacylglycerols; manifestation of a functional adaptation. FEBS Lett 2004; 555:631-7. [PMID: 14675786 DOI: 10.1016/s0014-5793(03)01343-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We compared UCP3 protein in rat cardiac, glycolytic and oxidative skeletal muscle and examined the effect of high-fat medium chain vs. long chain triacylglycerol feeding on UCP3 content in these tissues. Cardiac muscle displays the lowest basal levels of UCP3 protein. Increasing long chain - but not medium chain - fatty acid supply upregulates UCP3 in all muscles. Since plasma non-esterified fatty acids and the expression of two peroxisome proliferator-activated receptor (PPAR)-responsive genes, were not different between groups, we conclude that the differential upregulation of UCP3 is not merely PPAR-mediated. This study supports a role of UCP3 in export of non-metabolizable fatty acids.
Collapse
Affiliation(s)
- Joris Hoeks
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
25
|
de Lange P, Ragni M, Silvestri E, Moreno M, Schiavo L, Lombardi A, Farina P, Feola A, Goglia F, Lanni A. Combined cDNA array/RT‐PCR analysis of gene expression profile in rat gastrocnemius muscle: relation to its adaptive function in energy metabolism during fasting. FASEB J 2003; 18:350-2. [PMID: 14656997 DOI: 10.1096/fj.03-0342fje] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We evaluated the effects of fasting on the gene expression profile in rat gastrocnemius muscle using a combined cDNA array and RT-PCR approach. Of the 1176 distinct rat genes analyzed on the cDNA array, 114 were up-regulated more than twofold in response to fasting, including all 17 genes related to lipid metabolism present on the membranes and all 10 analyzed components of the proteasome machinery. Only 7 genes were down-regulated more than twofold. On the basis of our analysis of genes on the cDNA array plus the data from our RT-PCR assays, the metabolic adaptations shown by rat gastrocnemius muscle during fasting are reflected by i) increased transcription both of myosin heavy chain (MHC) Ib (associated with type I fibers) and of at least three factors involved in the shift toward type I fibers [p27kip1, muscle LIM protein (MLP), cystein rich protein-2], of which one (MLP) has been shown to enhance the activity of MyoD, which would explain the known increase in the expression of skeletal muscle uncoupling protein-3 (UCP3); ii) increased lipoprotein lipase (LPL) expression, known to trigger UCP3 transcription, which tends, together with the first point, to underline the suggested role of UCP3 in mitochondrial lipid handling (the variations under the first point and this one have not been observed in mice, indicating a species-specific regulation of these mechanisms); iii) reduced expression of the muscle-specific coenzyme Q (CoQ)7 gene, which is necessary for mitochondrial CoQ synthesis, together with an increased expression of mitochondrial adenylate kinase 3, which inactivates the resident key enzyme for CoQ synthesis, 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), the mRNA level for which fell during fasting; and iv) increased transcription of components of the proteasomal pathways involved in protein degradation/turnover.
Collapse
MESH Headings
- Animals
- Antigens, CD/genetics
- Energy Metabolism
- Fasting
- Free Radical Scavengers/metabolism
- Gene Expression Profiling
- Heat-Shock Proteins/genetics
- Lipid Metabolism
- Mitochondria/metabolism
- Muscle Fibers, Slow-Twitch
- Muscle, Skeletal/metabolism
- Myosin Heavy Chains/genetics
- Oligonucleotide Array Sequence Analysis
- Oxidative Phosphorylation
- Protein Kinases/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Receptor, Insulin/genetics
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Retinoic Acid/genetics
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type I
- Retinoid X Receptors
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription Factors/genetics
- Ubiquinone/biosynthesis
- Ubiquitin/genetics
- Ubiquitin-Conjugating Enzymes/genetics
Collapse
Affiliation(s)
- Pieter de Lange
- Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli (SUN), Caserta,
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Lewin TM, Coleman RA. Regulation of myocardial triacylglycerol synthesis and metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2003; 1634:63-75. [PMID: 14643794 DOI: 10.1016/j.bbalip.2003.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Studies showing a correlation of excess myocardial triacylglycerol stores with apoptosis, fibrosis, and contractile dysfunction indicate that dysregulation of triacylglycerol metabolism may contribute to cardiac disease. This review covers the regulation of heart triacylglycerol accumulation at the critical control points of fatty acid uptake, enzymes of triacylglycerol synthesis, lipolysis, and lipoprotein secretion. These pathways are discussed in the context of the central role myocardial triacylglycerol plays in cardiac energy metabolism and heart disease.
Collapse
Affiliation(s)
- Tal M Lewin
- Department of Nutrition, School of Public Health, University of North Carolina, CB #7400, Pittsboro Street, Chapel Hill, NC 27599, USA
| | | |
Collapse
|
27
|
Holst D, Luquet S, Nogueira V, Kristiansen K, Leverve X, Grimaldi PA. Nutritional regulation and role of peroxisome proliferator-activated receptor delta in fatty acid catabolism in skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1633:43-50. [PMID: 12842194 DOI: 10.1016/s1388-1981(03)00071-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors primarily involved in lipid homeostasis. PPARdelta displays strong expression in tissues with high lipid metabolism, such as adipose, intestine and muscle. Its role in skeletal muscle remains largely unknown. After a 24-h starvation period, PPARdelta mRNA levels are dramatically up-regulated in gastrocnemius muscle of mice and restored to control level upon refeeding. The rise of PPARdelta is accompanied by parallel up-regulations of fatty acid translocase/CD36 (FAT/CD36) and heart fatty acid binding protein (H-FABP), while refeeding promotes down-regulation of both genes. To directly access the role of PPARdelta in muscle cells, we forced its expression and that of a dominant-negative PPARdelta mutant in C2C12 myogenic cells. Differentiated C2C12 cells responds to 2-bromopalmitate or synthetic PPARdelta agonist by induction of genes involved in lipid metabolism and increment of fatty acid oxidation. Overexpression of PPARdelta enhanced these cellular responses, whereas expression of the dominant-negative mutant exerts opposite effects. These data strongly support a role for PPARdelta in the regulation of fatty acid oxidation in skeletal muscle and in adaptive response of this tissue to lipid catabolism.
Collapse
Affiliation(s)
- Dorte Holst
- Inserm U470, Institut de Recherche Signalisation, Biologie du Développement et Cancer, Centre de Biochimie, Faculté des Sciences, Parc Valrose, Université de Nice, 06108 Nice, France
| | | | | | | | | | | |
Collapse
|
28
|
Gilde AJ, van der Lee KAJM, Willemsen PHM, Chinetti G, van der Leij FR, van der Vusse GJ, Staels B, van Bilsen M. Peroxisome proliferator-activated receptor (PPAR) alpha and PPARbeta/delta, but not PPARgamma, modulate the expression of genes involved in cardiac lipid metabolism. Circ Res 2003; 92:518-24. [PMID: 12600885 DOI: 10.1161/01.res.0000060700.55247.7c] [Citation(s) in RCA: 325] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Long-chain fatty acids (FA) coordinately induce the expression of a panel of genes involved in cellular FA metabolism in cardiac muscle cells, thereby promoting their own metabolism. These effects are likely to be mediated by peroxisome proliferator-activated receptors (PPARs). Whereas the significance of PPARalpha in FA-mediated expression has been demonstrated, the role of the PPARbeta/delta and PPARgamma isoforms in cardiac lipid metabolism is unknown. To explore the involvement of each of the PPAR isoforms, neonatal rat cardiomyocytes were exposed to FA or to ligands specific for either PPARalpha (Wy-14,643), PPARbeta/delta (L-165041, GW501516), or PPARgamma (ciglitazone and rosiglitazone). Their effect on FA oxidation rate, expression of metabolic genes, and muscle-type carnitine palmitoyltransferase-1 (MCPT-1) promoter activity was determined. Consistent with the PPAR isoform expression pattern, the FA oxidation rate increased in cardiomyocytes exposed to PPARalpha and PPARbeta/delta ligands, but not to PPARgamma ligands. Likewise, the FA-mediated expression of FA-handling proteins was mimicked by PPARalpha and PPARbeta/delta, but not by PPARgamma ligands. As expected, in embryonic rat heart-derived H9c2 cells, which only express PPARbeta/delta, the FA-induced expression of genes was mimicked by the PPARbeta/delta ligand only, indicating that FA also act as ligands for the PPARbeta/delta isoform. In cardiomyocytes, MCPT-1 promoter activity was unresponsive to PPARgamma ligands. However, addition of PPARalpha and PPARbeta/delta ligands dose-dependently induced promoter activity. Collectively, the present findings demonstrate that, next to PPARalpha, PPARbeta/delta, but not PPARgamma, plays a prominent role in the regulation of cardiac lipid metabolism, thereby warranting further research into the role of PPARbeta/delta in cardiac disease.
Collapse
Affiliation(s)
- Andries J Gilde
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Pilegaard H, Saltin B, Neufer PD. Effect of short-term fasting and refeeding on transcriptional regulation of metabolic genes in human skeletal muscle. Diabetes 2003; 52:657-62. [PMID: 12606505 DOI: 10.2337/diabetes.52.3.657] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
During short-term fasting, substrate utilization in skeletal muscle shifts from predominantly carbohydrate to fat as a means of conserving glucose. To examine the potential influence of short-term fasting and refeeding on transcriptional regulation in skeletal muscle, muscle biopsies were obtained from nine male subjects at rest, after 20 h of fasting, and 1 h after consuming either a high-carbohydrate (CHO trial) or a low-carbohydrate (FAT trial) meal. Fasting induced an increase in transcription of the pyruvate dehydrogenase kinase 4 (PDK4) (10-fold), lipoprotein lipase (LPL) ( approximately 2-fold), uncoupling protein 3 (UCP3) ( approximately 5-fold), and carnitine palmitoyltransferase I (CPT I) ( approximately 2.5-fold) genes. Surprisingly, transcription of PDK4 and LPL increased further in response to refeeding (both trials) to more than 50-fold and 6- to 10-fold, respectively, over prefasting levels. However, responses varied among subjects with two subjects in particular displaying far greater activation of PDK4 (>100-fold) and LPL (>20-fold) than the other subjects (mean approximately 8-fold and approximately 2-fold, respectively). Transcription of UCP3 decreased to basal levels after the CHO meal but remained elevated after the FAT meal, whereas CPT I remained elevated after both refeeding meals. The present findings demonstrate that short-term fasting/refeeding in humans alters the transcription of several genes in skeletal muscle related to lipid metabolism. Marked heterogeneity in the transcriptional response to the fasting/refeeding protocol suggests that individual differences in genetic profile may play an important role in adaptive molecular responses to metabolic challenges.
Collapse
|
30
|
Ikeda K, Emoto N, Matsuo M, Yokoyama M. Molecular identification and characterization of a novel nuclear protein whose expression is up-regulated in insulin-resistant animals. J Biol Chem 2003; 278:3514-20. [PMID: 12456686 DOI: 10.1074/jbc.m204563200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Energy metabolism is the most fundamental capacity for mammals, impairment of which causes a variety of diseases such as type 2 diabetes and insulin resistance. Here, we identified a novel gene, termed diabetes-related ankyrin repeat protein (DARP) that is up-regulated in the heart of KKA(y) mouse, a type 2 diabetes and insulin resistance model animal. DARP contains putative nuclear localization signals and four tandem ankyrin-like repeats. Its expression is restricted in heart, skeletal muscle, and brown adipose. Western blot analysis and immunocytochemistry of DARP-transfected Chinese hamster ovary (CHO) and COS-7 cells reveal that DARP is a nuclear protein. When DARP is expressed in CHO cells, [1-(14)C]palmitate uptake is significantly decreased, whereas the palmitate oxidation does not show significant change. Furthermore, DARP expression is altered by the change of energy supply induced by excess fatty acid treatment of skeletal myotube in vitro and fasting treatment of C57 mouse in vivo. We confirmed that DARP expression is also altered in Zucker fatty rat, another insulin resistance model animal. Taken together, these data suggest that DARP is a novel nuclear protein potentially involved in the energy metabolism. Detailed analysis of DARP may provide new insights in the energy metabolism.
Collapse
Affiliation(s)
- Koji Ikeda
- Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan
| | | | | | | |
Collapse
|
31
|
Degens H, Gilde AJ, Lindhout M, Willemsen PHM, Van Der Vusse GJ, Van Bilsen M. Functional and metabolic adaptation of the heart to prolonged thyroid hormone treatment. Am J Physiol Heart Circ Physiol 2003; 284:H108-15. [PMID: 12388319 DOI: 10.1152/ajpheart.00282.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In heart failure, thyroid hormone (TH) treatment improves cardiac performance. The long-term effects of TH on cardiac function and metabolism, however, are incompletely known. To investigate the effects of up to 28 days of TH treatment, male Wistar rats received 3,3',5-triiodo-l-thyronine (200 microg/kg sc per day) leading to a 2.5-fold rise in plasma fatty acid (FA) level and progressive cardiac hypertrophy (+47% after 28 days) (P < 0.001). Ejection fraction (echocardiography) was increased (+12%; P < 0.05) between 7 and 14 days and declined thereafter. Neither cardiac FA oxidation, glycolytic capacity (homogenates) per unit muscle mass, nor mRNA levels of proteins involved in FA and glucose uptake and metabolism (Northern blots and microarray) were altered. After 28 days of treatment, mRNA levels of uncoupling proteins (UCP) 2 and 3 and atrial natriuretic factor were increased (P < 0.05). This indicates that TH-induced hypertrophy is associated with an initial increase in cardiac performance, followed by a decline in cardiac function and increased expression of UCPs and atrial natriuretic factor, suggesting that detrimental effects eventually prevail.
Collapse
Affiliation(s)
- H Degens
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands
| | | | | | | | | | | |
Collapse
|
32
|
van der Vusse GJ, van Bilsen M, Glatz JFC, Hasselbaink DM, Luiken JJFP. Critical steps in cellular fatty acid uptake and utilization. Mol Cell Biochem 2002; 239:9-15. [PMID: 12479563 DOI: 10.1007/978-1-4419-9270-3_2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Despite decades of extensive research, the transport routes, mechanisms of uptake and points of flux control of long-chain fatty acids (FA) in mammalian organs are still incompletely understood. In non-fenestratred organs such as heart and skeletal muscle, membrane barriers for blood-borne FA are the luminal and abluminal membranes of endothelial cells, the sarcolemma and the mitochondrial membranes. Transport of FA through the phospholipid bilayer of the cellular membrane is most likely accomplished by diffusion of protonated FA. Evidence is accumulating that membrane-associated proteins, such as plasmalemmal fatty acid-binding protein (FABPpm) and fatty acid translocase (FAT/CD36), either alone or in conjunction with albumin binding protein (ABP), are instrumental in enhancing the delivery of FA to the cellular membrane. Inside the cell, cytoplasmic fatty acid-binding proteins (FABPc) are involved in diffusion of FA from the plasmalemma to the intracellular sites of conversion, such as the mitochondrial outer membrane. After conversion of FA to FACoA, the fatty acyl chain is transported across the mitochondrial inner membrane in a carnitine-mediated fashion. Uptake and utilization of FA by muscle cells are finely tuned, most likely to avoid the intracellular accumulation of FA, as these are cytotoxic at high concentrations. On a short-term basis, net uptake is, among others, regulated by intracellular translocation of FAT from intracellular stores to the sarcolemma and by the concentration gradient of FA across the sarcolemma. The latter implies that, among others, the rate of FA utilization determines the rate of uptake. The rate of utilization is governed by a variety of factors, including malonylCoA, the ratio acetylCoA/CoA and the availability of competing substrates such as glucose, lactate, and ketone bodies. Long-term regulation of uptake and utilization is accomplished by alterations in the rate of expression of genes, encoding for FA-handling proteins. Circumstantial evidence indicates that FA themselves are able to modulate the expression of FA-handling genes via nuclear transcription factors such as peroxisome proliferator-activated receptors (PPARs).
Collapse
Affiliation(s)
- Ger J van der Vusse
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
| | | | | | | | | |
Collapse
|
33
|
Vettor R, Fabris R, Serra R, Lombardi AM, Tonello C, Granzotto M, Marzolo MO, Carruba MO, Ricquier D, Federspil G, Nisoli E. Changes in FAT/CD36, UCP2, UCP3 and GLUT4 gene expression during lipid infusion in rat skeletal and heart muscle. Int J Obes (Lond) 2002; 26:838-47. [PMID: 12037655 DOI: 10.1038/sj.ijo.0802005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2001] [Revised: 12/20/2001] [Accepted: 01/04/2002] [Indexed: 11/09/2022]
Abstract
OBJECTIVE It has been reported that an increased availability of free fatty acids (NEFA) not only interferes with glucose utilization in insulin-dependent tissues, but may also result in an uncoupling effect of heart metabolism. We aimed therefore to investigate the effect of an increased availability of NEFA on gene expression of proteins involved in transmembrane fatty acid (FAT/CD36) and glucose (GLUT4) transport and of the uncoupling proteins UCP2 and 3 at the heart and skeletal muscle level. STUDY DESIGN Euglycemic hyperinsulinemic clamp was performed after 24 h Intralipid(R) plus heparin or saline infusion in lean Zucker rats. Skeletal and heart muscle glucose utilization was calculated by 2-deoxy-[1-(3)H]-D-glucose technique. Quantification of FAT/CD36, GLUT4, UCP2 and UCP3 mRNAs was obtained by Northern blot analysis or RT-PCR. RESULTS In Intralipid(R) plus heparin infused animals a significant decrease in insulin-mediated glucose uptake was observed both in the heart (22.62+/-2.04 vs 10.37+/-2.33 ng/mg/min; P<0.01) and in soleus muscle (13.46+/-1.53 vs 6.84+/-2.58 ng/mg/min; P<0.05). FAT/CD36 mRNA was significantly increased in skeletal muscle tissue (+117.4+/-16.3%, P<0.05), while no differences were found at the heart level in respect to saline infused rats. A clear decrease of GLUT4 mRNA was observed in both tissues. The 24 h infusion of fat emulsion resulted in a clear enhancement of UCP2 and UCP3 mRNA levels in the heart (99.5+/-15.3 and 80+/-4%) and in the skeletal muscle (291.5+/-24.7 and 146.9+/-12.7%). CONCLUSIONS As a result of the increased availability of NEFA, FAT/CD36 gene expression increases in skeletal muscle, but not at the heart level. The augmented lipid fuel supply is responsible for the depression of insulin-mediated glucose transport and for the increase of UCP2 and 3 gene expression in both skeletal and heart muscle.
Collapse
Affiliation(s)
- R Vettor
- Internal Medicine, Department of Medical and Surgical Sciences, University of Padova, Padova, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|