1
|
Vieira-Lara MA, Bakker BM. The paradox of fatty-acid β-oxidation in muscle insulin resistance: Metabolic control and muscle heterogeneity. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167172. [PMID: 38631409 DOI: 10.1016/j.bbadis.2024.167172] [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: 12/17/2023] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
The skeletal muscle is a metabolically heterogeneous tissue that plays a key role in maintaining whole-body glucose homeostasis. It is well known that muscle insulin resistance (IR) precedes the development of type 2 diabetes. There is a consensus that the accumulation of specific lipid species in the tissue can drive IR. However, the role of the mitochondrial fatty-acid β-oxidation in IR and, consequently, in the control of glucose uptake remains paradoxical: interventions that either inhibit or activate fatty-acid β-oxidation have been shown to prevent IR. We here discuss the current theories and evidence for the interplay between β-oxidation and glucose uptake in IR. To address the underlying intricacies, we (1) dive into the control of glucose uptake fluxes into muscle tissues using the framework of Metabolic Control Analysis, and (2) disentangle concepts of flux and catalytic capacities taking into account skeletal muscle heterogeneity. Finally, we speculate about hitherto unexplored mechanisms that could bring contrasting evidence together. Elucidating how β-oxidation is connected to muscle IR and the underlying role of muscle heterogeneity enhances disease understanding and paves the way for new treatments for type 2 diabetes.
Collapse
Affiliation(s)
- Marcel A Vieira-Lara
- Laboratory of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Barbara M Bakker
- Laboratory of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| |
Collapse
|
2
|
Liu Y, Han SL, Luo Y, Li LY, Chen LQ, Zhang ML, Du ZY. Impaired peroxisomal fat oxidation induces hepatic lipid accumulation and oxidative damage in Nile tilapia. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:1229-1242. [PMID: 32144523 DOI: 10.1007/s10695-020-00785-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/27/2020] [Indexed: 05/08/2023]
Abstract
Many metabolic diseases in fish are often associated with lowered peroxisomal fatty acid (FA) β-oxidation. However, the physiological role of peroxisomal FA oxidation in lipid metabolism in fish still remains unclear. In the present study, a specific peroxisomal FA β-oxidation inhibitor, 10,12-tricosadiynoic acid (TDYA), was used to investigate the effects of impaired peroxisomal β-oxidation on growth performance, health status, and lipid metabolism in Nile tilapia. The results showed that the dietary TDYA treatment did not affect weight gain, but significantly decreased peroxisomal β-oxidation in the liver, and increased body fat accumulation. The fish with impaired peroxisomal β-oxidation exhibited higher contents of serum lipid and peroxidation products, and alanine aminotransferase activity, and significantly lowered hepatic activities of superoxide dismutase and catalase. The inhibited peroxisomal β-oxidation did not enhance mitochondrial β-oxidation activity, but compensatorily upregulated FA β-oxidation-related gene expression, and downregulated the gene expressions in lipolysis and lipogenesis. Taken together, TDYA treatment markedly induced lipid accumulation and hepatic oxidative damage via systemically depressing lipid catabolism and antioxidant capacity. Our findings reveal the pivotal roles of peroxisomal β-oxidation in maintaining health and lipid homeostasis in fish, and could be helpful in understanding metabolic diseases in fish.
Collapse
Affiliation(s)
- Yan Liu
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Si-Lan Han
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yuan Luo
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Ling-Yu Li
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, 200241, China.
| |
Collapse
|
3
|
Houten SM, Wanders RJA, Ranea-Robles P. Metabolic interactions between peroxisomes and mitochondria with a special focus on acylcarnitine metabolism. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165720. [PMID: 32057943 DOI: 10.1016/j.bbadis.2020.165720] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/13/2022]
Abstract
Carnitine plays an essential role in mitochondrial fatty acid β-oxidation as a part of a cycle that transfers long-chain fatty acids across the mitochondrial membrane and involves two carnitine palmitoyltransferases (CPT1 and CPT2). Two distinct carnitine acyltransferases, carnitine octanoyltransferase (COT) and carnitine acetyltransferase (CAT), are peroxisomal enzymes, which indicates that carnitine is not only important for mitochondrial, but also for peroxisomal metabolism. It has been demonstrated that after peroxisomal metabolism, specific intermediates can be exported as acylcarnitines for subsequent and final mitochondrial metabolism. There is also evidence that peroxisomes are able to degrade fatty acids that are typically handled by mitochondria possibly after transport as acylcarnitines. Here we review the biochemistry and physiological functions of metabolite exchange between peroxisomes and mitochondria with a special focus on acylcarnitines.
Collapse
Affiliation(s)
- Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA.
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology & Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - Pablo Ranea-Robles
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| |
Collapse
|
4
|
Han SL, Wang J, Zhang YX, Qiao F, Chen LQ, Zhang ML, Du ZY. Inhibited autophagy impairs systemic nutrient metabolism in Nile tilapia. Comp Biochem Physiol A Mol Integr Physiol 2019; 236:110521. [DOI: 10.1016/j.cbpa.2019.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 12/13/2022]
|
5
|
Guasch-Ferré M, Ruiz-Canela M, Li J, Zheng Y, Bulló M, Wang DD, Toledo E, Clish C, Corella D, Estruch R, Ros E, Fitó M, Arós F, Fiol M, Lapetra J, Serra-Majem L, Liang L, Papandreou C, Dennis C, Martínez-González MA, Hu FB, Salas-Salvadó J. Plasma Acylcarnitines and Risk of Type 2 Diabetes in a Mediterranean Population at High Cardiovascular Risk. J Clin Endocrinol Metab 2019; 104:1508-1519. [PMID: 30423132 PMCID: PMC6435097 DOI: 10.1210/jc.2018-01000] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023]
Abstract
CONTEXT The potential associations between acylcarnitine profiles and incidence of type 2 diabetes (T2D) and whether acylcarnitines can be used to improve diabetes prediction remain unclear. OBJECTIVE To evaluate the associations between baseline and 1-year changes in acylcarnitines and their diabetes predictive ability beyond traditional risk factors. DESIGN, SETTING, AND PARTICIPANTS We designed a case-cohort study within the PREDIMED Study including all incident cases of T2D (n = 251) and 694 randomly selected participants at baseline (follow-up, 3.8 years). Plasma acylcarnitines were measured using a targeted approach by liquid chromatography-tandem mass spectrometry. We tested the associations between baseline and 1-year changes in individual acylcarnitines and T2D risk using weighted Cox regression models. We used elastic net regressions to select acylcarnitines for T2D prediction and compute a weighted score using a cross-validation approach. RESULTS An acylcarnitine profile, especially including short- and long-chain acylcarnitines, was significantly associated with a higher risk of T2D independent of traditional risk factors. The relative risks of T2D per SD increment of the predictive model scores were 4.03 (95% CI, 3.00 to 5.42; P < 0.001) for the conventional model and 4.85 (95% CI, 3.65 to 6.45; P < 0.001) for the model including acylcarnitines, with a hazard ratio of 1.33 (95% CI, 1.08 to 1.63; P < 0.001) attributed to the acylcarnitines. Including the acylcarnitines into the model did not significantly improve the area under the receiver operator characteristic curve (0.86 to 0.88, P = 0.61). A 1-year increase in C4OH-carnitine was associated with higher risk of T2D [per SD increment, 1.44 (1.03 to 2.01)]. CONCLUSIONS An acylcarnitine profile, mainly including short- and long-chain acylcarnitines, was significantly associated with higher T2D risk in participants at high cardiovascular risk. The inclusion of acylcarnitines into the model did not significantly improve the T2D prediction C-statistics beyond traditional risk factors, including fasting glucose.
Collapse
Affiliation(s)
- Marta Guasch-Ferré
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Human Nutrition Unit, Faculty of Medicine and Health Sciences, Pere Virgili Health Research Institute, Rovira i Virgili University, Reus, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- Correspondence and Reprint Requests: Marta Guasch-Ferré, PhD, or Jordi Salas-Salvadó, MD, PhD, Human Nutrition Unit, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain. E-mail: or
| | - Miguel Ruiz-Canela
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- University of Navarra, Department of Preventive Medicine and Public Health, Pamplona, Spain
- Health Research Institute of Navarra, Pamplona, Spain
| | - Jun Li
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Yan Zheng
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Mònica Bulló
- Human Nutrition Unit, Faculty of Medicine and Health Sciences, Pere Virgili Health Research Institute, Rovira i Virgili University, Reus, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Dong D Wang
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Estefanía Toledo
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- University of Navarra, Department of Preventive Medicine and Public Health, Pamplona, Spain
- Health Research Institute of Navarra, Pamplona, Spain
| | - Clary Clish
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts
| | - Dolores Corella
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Preventive Medicine, University of Valencia, Valencia, Spain
| | - Ramon Estruch
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Internal Medicine, Hospital Clinic, August Pi Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Emilio Ros
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Lipid Clinic, Department of Endocrinology and Nutrition, Hospital Clinic, University of Barcelona, Barcelona, Spain
| | - Montserrat Fitó
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Cardiovascular and Nutrition Research Group (REGICOR Study Group), Hospital del Mar Research Institute, Barcelona, Spain
| | - Fernando Arós
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Cardiology, Organización Sanitaria Integrada (OSI) ARABA, Universidad del País Vasco/Euskal Herriko Univertsitatea (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Miquel Fiol
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Institute of Health Sciences (Institut Universitari d’Investigació en Ciències de la Salut-IUNICS), University of Balearic Islands and Hospital Son Espases, Palma de Mallorca, Spain
| | - José Lapetra
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Department of Family Medicine, Research Unit, Distrito Sanitario Atención Primaria Sevilla, Sevilla, Spain
| | - Lluís Serra-Majem
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria and Service of Preventive Medicine, Complejo Hospitalario Universitario Insular Materno Infantil (CHUIMI), Canary Health Service, Las Palmas de Gran Canaria, Spain
| | - Liming Liang
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Christopher Papandreou
- Human Nutrition Unit, Faculty of Medicine and Health Sciences, Pere Virgili Health Research Institute, Rovira i Virgili University, Reus, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Courtney Dennis
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts
| | - Miguel A Martínez-González
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- University of Navarra, Department of Preventive Medicine and Public Health, Pamplona, Spain
- Health Research Institute of Navarra, Pamplona, Spain
| | - Frank B Hu
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Jordi Salas-Salvadó
- Human Nutrition Unit, Faculty of Medicine and Health Sciences, Pere Virgili Health Research Institute, Rovira i Virgili University, Reus, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- Correspondence and Reprint Requests: Marta Guasch-Ferré, PhD, or Jordi Salas-Salvadó, MD, PhD, Human Nutrition Unit, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain. E-mail: or
| |
Collapse
|
6
|
Rajkumar A, Liaghati A, Chan J, Lamothe G, Dent R, Doucet É, Rabasa-Lhoret R, Prud'homme D, Harper ME, Tesson F. ACSL5 genotype influence on fatty acid metabolism: a cellular, tissue, and whole-body study. Metabolism 2018; 83:271-279. [PMID: 29605434 DOI: 10.1016/j.metabol.2018.03.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/04/2018] [Accepted: 03/22/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Acyl-CoA Synthetase Long Chain 5 (ACSL5) gene's rs2419621 T/C polymorphism was associated with ACSL5 mRNA expression and response to lifestyle interventions. However, the mechanistic understanding of the increased response in T allele carriers is lacking. Study objectives were to investigate the effect of rs2419621 genotype and ACSL5 human protein isoforms on fatty acid oxidation and respiration. METHODS Human ACSL5 overexpression in C2C12 mouse myoblasts was conducted to measure 14C palmitic acid oxidation and protein isoform localization in vitro. 14C palmitic acid oxidation studies and Western blot analysis of ACSL5 proteins were carried out in rectus abdominis primary myotubes from 5 rs2419621 T allele carriers and 4 non-carriers. In addition, mitochondrial high-resolution respirometry was conducted on vastus lateralis muscle biopsies from 4 rs2419621 T allele carriers and 4 non-carriers. Multiple linear regression analysis was conducted to test the association between rs2419621 genotype and respiratory quotient related pre- and post-lifestyle intervention measurements in postmenopausal women with overweight or obesity. RESULTS In comparison to rs2419621 non-carriers, T allele carriers displayed higher levels of i) 683aa ACSL5 isoform, localized mainly in the mitochondria, playing a greater role in fatty acid oxidation in comparison to the 739aa protein isoform ii) in vitro CO2 production in rectus abdominis primary myotubes iii) in vivo fatty acid oxidation and lower carbohydrate oxidation post-intervention iv) ex vivo complex I and II tissue respiration in vastus lateralis muscle. CONCLUSIONS These results support the conclusion that rs2419621 T allele carriers, are more responsive to lifestyle interventions partly due to an increase in the short ACSL5 protein isoform, increasing cellular, tissue and whole-body fatty acid utilization. With the increasing effort to develop personalized medicine to combat obesity, our findings provide additional insight into genotypes that can significantly affect whole body metabolism and response to lifestyle interventions.
Collapse
Affiliation(s)
- Abishankari Rajkumar
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Awa Liaghati
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Jessica Chan
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Gilles Lamothe
- Department of Mathematics and Statistics, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Robert Dent
- The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada.
| | - Éric Doucet
- School of Human Kinetics, University of Ottawa, Ottawa, ON K1S 5L5, Canada.
| | - Rémi Rabasa-Lhoret
- Département de Nutrition, Université de Montréal, Montréal, QC H3T 1A8, Canada; Institut de Recherches Cliniques de Montréal, Montréal, QC H2W 1R7, Canada.
| | - Denis Prud'homme
- School of Human Kinetics, University of Ottawa, Ottawa, ON K1S 5L5, Canada; Institut de Recherche de l'Hôpital Montfort, Hôpital Montfort, Ottawa, ON K1K 0T1, Canada.
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Frédérique Tesson
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| |
Collapse
|
7
|
Li JM, Li LY, Qin X, Degrace P, Demizieux L, Limbu SM, Wang X, Zhang ML, Li DL, Du ZY. Inhibited Carnitine Synthesis Causes Systemic Alteration of Nutrient Metabolism in Zebrafish. Front Physiol 2018; 9:509. [PMID: 29867554 PMCID: PMC5954090 DOI: 10.3389/fphys.2018.00509] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/20/2018] [Indexed: 12/30/2022] Open
Abstract
Impaired mitochondrial fatty acid β-oxidation has been correlated with many metabolic syndromes, and the metabolic characteristics of the mammalian models of mitochondrial dysfunction have also been intensively studied. However, the effects of the impaired mitochondrial fatty acid β-oxidation on systemic metabolism in teleost have never been investigated. In the present study, we established a low-carnitine zebrafish model by feeding fish with mildronate as a specific carnitine synthesis inhibitor [0.05% body weight (BW)/d] for 7 weeks, and the systemically changed nutrient metabolism, including carnitine and triglyceride (TG) concentrations, fatty acid (FA) β-oxidation capability, and other molecular and biochemical assays of lipid, glucose, and protein metabolism, were measured. The results indicated that mildronate markedly decreased hepatic carnitine concentrations while it had no effect in muscle. Liver TG concentrations increased by more than 50% in mildronate-treated fish. Mildronate decreased the efficiency of liver mitochondrial β-oxidation, increased the hepatic mRNA expression of genes related to FA β-oxidation and lipolysis, and decreased the expression of lipogenesis genes. Mildronate decreased whole body glycogen content, increased glucose metabolism rate, and upregulated the expression of glucose uptake and glycolysis genes. Mildronate also increased whole body protein content and hepatic mRNA expression of mechanistic target of rapamycin (mtor), and decreased the expression of a protein catabolism-related gene. Liver, rather than muscle, was the primary organ targeted by mildronate. In short, mildronate-induced hepatic inhibited carnitine synthesis in zebrafish caused decreased mitochondrial FA β-oxidation efficiency, greater lipid accumulation, and altered glucose and protein metabolism. This reveals the key roles of mitochondrial fatty acid β-oxidation in nutrient metabolism in fish, and this low-carnitine zebrafish model could also be used as a novel fish model for future metabolism studies.
Collapse
Affiliation(s)
- Jia-Min Li
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Ling-Yu Li
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Xuan Qin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Pascal Degrace
- Team Pathophysiology of Dyslipidemia, Faculty of Sciences Gabriel, INSERM UMR1231 "Lipides, Nutrition, Cancer," Université Bourgogne Franche-Comté, Dijon, France
| | - Laurent Demizieux
- Team Pathophysiology of Dyslipidemia, Faculty of Sciences Gabriel, INSERM UMR1231 "Lipides, Nutrition, Cancer," Université Bourgogne Franche-Comté, Dijon, France
| | - Samwel M Limbu
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China.,Department of Aquatic Sciences and Fisheries Technology, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Xin Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Dong-Liang Li
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| |
Collapse
|
8
|
Pan H, Li LY, Li JM, Wang WL, Limbu SM, Degrace P, Li DL, Du ZY. Inhibited fatty acid β-oxidation impairs stress resistance ability in Nile tilapia (Oreochromis niloticus). FISH & SHELLFISH IMMUNOLOGY 2017; 68:500-508. [PMID: 28774846 DOI: 10.1016/j.fsi.2017.07.058] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 07/24/2017] [Accepted: 07/29/2017] [Indexed: 05/23/2023]
Abstract
Energy metabolism plays important roles in stress resistance and immunity in mammals, however, such functions have not been established in fish. In the present study, Nile tilapia (Oreochromis niloticus) was fed with mildronate, an inhibitor of mitochondrial fatty acid (FA) β-oxidation, for six weeks subsequently challenged with Aeromonas hydrophila and ammonia nitrogen exposure. Mildronate treatment reduced significantly l-carnitine concentration and mitochondrial FA β-oxidation efficiency, while it increased lipid accumulation in liver. The fish with inhibited hepatic FA catabolism had lower survival rate when exposed to Aeromonas hydrophila and ammonia nitrogen. Moreover, fish fed mildronate supplemented diet had lower immune enzymes activities and anti-inflammatory cytokine genes expressions, but had higher pro-inflammatory cytokine genes expressions. However, the oxidative stress-related biochemical indexes were not significantly affected by mildronate treatment. Taken together, inhibited mitochondrial FA β-oxidation impaired stress resistance ability in Nile tilapia mainly through inhibiting immune functions and triggering inflammation. This is the first study showing the regulatory effects of lipid catabolism on stress resistance and immune functions in fish.
Collapse
Affiliation(s)
- Han Pan
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China
| | - Ling-Yu Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China
| | - Jia-Min Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China
| | - Wei-Li Wang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China
| | - Samwel Mchele Limbu
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China; Department of Aquatic Sciences and Fisheries Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania
| | - Pascal Degrace
- Team Pathophysiology of Dyslipidemia, INSERM UMR1231, "Lipids, Nutrition, Cancer", Université de Bourgogne Franche-Comté, Dijon, France
| | - Dong-Liang Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China.
| | - Zhen-Yu Du
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, PR China.
| |
Collapse
|
9
|
Ning LJ, He AY, Lu DL, Li JM, Qiao F, Li DL, Zhang ML, Chen LQ, Du ZY. Nutritional background changes the hypolipidemic effects of fenofibrate in Nile tilapia (Oreochromis niloticus). Sci Rep 2017; 7:41706. [PMID: 28139735 PMCID: PMC5282496 DOI: 10.1038/srep41706] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 12/29/2016] [Indexed: 12/15/2022] Open
Abstract
Peroxisome proliferation activated receptor α (PPARα) is an important transcriptional regulator of lipid metabolism and is activated by high-fat diet (HFD) and fibrates in mammals. However, whether nutritional background affects PPARα activation and the hypolipidemic effects of PPARα ligands have not been investigated in fish. In the present two-phase study of Nile tilapia (Oreochromis niloticus), fish were first fed a HFD (13% fat) or low-fat diet (LFD; 1% fat) diet for 10 weeks, and then fish from the first phase were fed the HFD or LFD supplemented with 200 mg/kg body weight fenofibrate for 4 weeks. The results indicated that the HFD did not activate PPARα or other lipid catabolism-related genes. Hepatic fatty acid β-oxidation increased significantly in the HFD and LFD groups after the fenofibrate treatment, when exogenous substrates were sufficiently provided. Only in the HFD group, fenofibrate significantly increased hepatic PPARα mRNA and protein expression, and decreased liver and plasma triglyceride concentrations. This is the first study to show that body fat deposition and dietary lipid content affects PPARα activation and the hypolipidemic effects of fenofibrate in fish, and this could be due to differences in substrate availability for lipid catabolism in fish fed with different diets.
Collapse
Affiliation(s)
- Li-Jun Ning
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - An-Yuan He
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Dong-Liang Lu
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Jia-Min Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Fang Qiao
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Dong-Liang Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Li-Qiao Chen
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| |
Collapse
|
10
|
Systemic regulation of L-carnitine in nutritional metabolism in zebrafish, Danio rerio. Sci Rep 2017; 7:40815. [PMID: 28102299 PMCID: PMC5244368 DOI: 10.1038/srep40815] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/12/2016] [Indexed: 12/26/2022] Open
Abstract
Excess fat accumulation has been observed widely in farmed fish; therefore, efficient lipid-lowering factors have obtained high attention in the current fish nutrition studies. Dietary L-carnitine can increase fatty acid β-oxidation in mammals, but has produced contradictory results in different fish species. To date, the mechanisms of metabolic regulation of L-carnitine in fish have not been fully determined. The present study used zebrafish to investigate the systemic regulation of nutrient metabolism by dietary L-carnitine supplementation. L-carnitine significantly decreased the lipid content in liver and muscle, accompanied by increased concentrations of total and free carnitine in tissues. Meanwhile, L-carnitine enhanced mitochondrial β-oxidation activities and the expression of carnitine palmitoyltransferase 1 mRNA significantly, whereas it depressed the mRNA expression of adipogenesis-related genes. In addition, L-carnitine caused higher glycogen deposition in the fasting state, and increased and decreased the mRNA expressions of gluconeogenesis-related and glycolysis-related genes, respectively. L-carnitine also increased the hepatic expression of mTOR in the feeding state. Taken together, dietary L-carnitine supplementation decreased lipid deposition by increasing mitochondrial fatty acid β-oxidation, and is likely to promote protein synthesis. However, the L-carnitine-enhanced lipid catabolism would cause a decrease in glucose utilization. Therefore, L-carnitine has comprehensive effects on nutrient metabolism in fish.
Collapse
|
11
|
Ning LJ, He AY, Li JM, Lu DL, Jiao JG, Li LY, Li DL, Zhang ML, Chen LQ, Du ZY. Mechanisms and metabolic regulation of PPARα activation in Nile tilapia (Oreochromis niloticus). Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1036-1048. [PMID: 27320014 DOI: 10.1016/j.bbalip.2016.06.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/30/2016] [Accepted: 06/10/2016] [Indexed: 11/28/2022]
Abstract
Although the key metabolic regulatory functions of mammalian peroxisome proliferator-activated receptor α (PPARα) have been thoroughly studied, the molecular mechanisms and metabolic regulation of PPARα activation in fish are less known. In the first part of the present study, Nile tilapia (Nt)PPARα was cloned and identified, and high mRNA expression levels were detected in the brain, liver, and heart. NtPPARα was activated by an agonist (fenofibrate) and by fasting and was verified in primary hepatocytes and living fish by decreased phosphorylation of NtPPARα and/or increased NtPPARα mRNA and protein expression. In the second part of the present work, fenofibrate was fed to fish or fish were fasted for 4weeks to investigate the metabolic regulatory effects of NtPPARα. A transcriptomic study was also performed. The results indicated that fenofibrate decreased hepatic triglyceride and 18C-series fatty acid contents but increased the catabolic rate of intraperitoneally injected [1-(14)C] palmitate in vivo, hepatic mitochondrial β-oxidation efficiency, the quantity of cytochrome b DNA, and carnitine palmitoyltransferase-1a mRNA expression. Fenofibrate also increased serum glucose, insulin, and lactate concentrations. Fasting had stronger hypolipidemic and gene regulatory effects than those of fenofibrate. Taken together, we conclude that: 1) liver is one of the main target tissues of the metabolic regulation of NtPPARα activation; 2) dephosphorylation is the basal NtPPARα activation mechanism rather than enhanced mRNA and protein expression; 3) activated NtPPARα has a hypolipidemic effect by increasing activity and the number of hepatic mitochondria; and 4) PPARα activation affects carbohydrate metabolism by altering energy homeostasis among nutrients.
Collapse
Affiliation(s)
- Li-Jun Ning
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - An-Yuan He
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Jia-Min Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Dong-Liang Lu
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Jian-Gang Jiao
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Ling-Yu Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Dong-Liang Li
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Mei-Ling Zhang
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Li-Qiao Chen
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhen-Yu Du
- Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, China.
| |
Collapse
|
12
|
Aguer C, Fiehn O, Seifert EL, Bézaire V, Meissen JK, Daniels A, Scott K, Renaud JM, Padilla M, Bickel DR, Dysart M, Adams SH, Harper ME. Muscle uncoupling protein 3 overexpression mimics endurance training and reduces circulating biomarkers of incomplete β-oxidation. FASEB J 2013; 27:4213-25. [PMID: 23825224 DOI: 10.1096/fj.13-234302] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Exercise substantially improves metabolic health, making the elicited mechanisms important targets for novel therapeutic strategies. Uncoupling protein 3 (UCP3) is a mitochondrial inner membrane protein highly selectively expressed in skeletal muscle. Here we report that moderate UCP3 overexpression (roughly 3-fold) in muscles of UCP3 transgenic (UCP3 Tg) mice acts as an exercise mimetic in many ways. UCP3 overexpression increased spontaneous activity (∼40%) and energy expenditure (∼5-10%) and decreased oxidative stress (∼15-20%), similar to exercise training in wild-type (WT) mice. The increase in complete fatty acid oxidation (FAO; ∼30% for WT and ∼70% for UCP3 Tg) and energy expenditure (∼8% for WT and 15% for UCP3 Tg) in response to endurance training was higher in UCP3 Tg than in WT mice, showing an additive effect of UCP3 and endurance training on these two parameters. Moreover, increases in circulating short-chain acylcarnitines in response to acute exercise in untrained WT mice were absent with training or in UCP3 Tg mice. UCP3 overexpression had the same effect as training in decreasing long-chain acylcarnitines. Outcomes coincided with a reduction in muscle carnitine acetyltransferase activity that catalyzes the formation of acylcarnitines. Overall, results are consistent with the conclusions that circulating acylcarnitines could be used as a marker of incomplete muscle FAO and that UCP3 is a potential target for the treatment of prevalent metabolic diseases in which muscle FAO is affected.
Collapse
Affiliation(s)
- Céline Aguer
- 2M.-E.H., Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON K1H 8M5, Canada.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Faure C, Morio B, Chafey P, Le Plénier S, Noirez P, Randrianarison-Huetz V, Cynober L, Aussel C, Moinard C. Citrulline enhances myofibrillar constituents expression of skeletal muscle and induces a switch in muscle energy metabolism in malnourished aged rats. Proteomics 2013; 13:2191-201. [PMID: 23592530 DOI: 10.1002/pmic.201200262] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 03/01/2013] [Accepted: 03/30/2013] [Indexed: 11/07/2022]
Abstract
Citrulline (Cit) actions on muscle metabolism remain unclear. Those latter were investigated using a proteomic approach on Tibialis muscles from male Sprague-Dawley rats. At 23 months of age, rats were either fed ad libitum (AL group) or subjected to dietary restriction for 12 weeks. At the end of the restriction period, one group of rats was euthanized (R group) and two groups were refed for one week with a standard diet supplemented with nonessential amino acids group or Cit (CIT group). Results of the proteomic approach were validated using targeted Western blot analysis and assessment of gene expression of the related genes. Maximal activities of the key enzymes involved in mitochondrial functioning were also determined. Cit supplementation results in a significant increase in the protein expression of the main myofibrillar constituents and of a few enzymes involved in glycogenolysis and glycolysis (CIT vs. AL and R, p < 0.05). Conversely, the expression of oxidative enzymes from Krebs cycle and mitochondrial respiratory chain was significantly decreased (CIT vs. AL, p < 0.05). However, maximal activities of key enzymes of mitochondrial metabolism were not significantly affected, except for complex 1 which presented an increased activity (CIT vs. AL and R, p < 0.05). In conclusion, Cit supplementation increases expression of the main myofibrillar proteins and seems to induce a switch in muscle energy metabolism, from aerobia toward anaerobia.
Collapse
Affiliation(s)
- Cécile Faure
- Département de Biologie Expérimentale, Métabolique et Clinique (EA 4466), Faculté de pharmacie, Université Paris Descartes, Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Mihalik SJ, Goodpaster BH, Kelley DE, Chace DH, Vockley J, Toledo FG, DeLany JP. Increased levels of plasma acylcarnitines in obesity and type 2 diabetes and identification of a marker of glucolipotoxicity. Obesity (Silver Spring) 2010; 18:1695-700. [PMID: 20111019 PMCID: PMC3984458 DOI: 10.1038/oby.2009.510] [Citation(s) in RCA: 471] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Dysregulation of fatty acid oxidation (FAO) is recognized as important in the pathophysiology of obesity and insulin resistance (IR). However, demonstrating FAO defects in vivo in humans has entailed complex and invasive methodologies. Recently, the identification of genetic blocks in FAO has been vastly simplified by using tandem mass spectrometry (MS/MS) of dried bloodspots to specify acylcarnitine (AcylCN) alterations characteristic for each disorder. This technology has recently been applied to examine FAO alterations in human and animal models of obesity and type 2 diabetes mellitus (T2DM). This study focused on characterizing AcylCN profiles in human plasma from individuals with obesity and T2DM during fasting and insulin-stimulated conditions. Following an overnight fast, plasma was obtained from lean (n = 12), obese nondiabetic (n = 14), and T2DM (n = 10) participants and analyzed for AcylCN using MS/MS. Plasma samples were also obtained at the end of a 4-h insulin-stimulated euglycemic clamp. In obesity and T2DM, long-chain AcylCNs were similarly significantly increased in the fasted state; free-CN levels were also elevated. Additionally, T2DM subjects of comparable BMI had increased short- and medium-chain AcylCNs, both saturated and hydroxy, as well as increased C(4)-dicarboxylcarnitine (C(4)DC-CN) that correlated with an index of poor glycemic control (HbA(1c); r = 0.74; P < 0.0001). Insulin infusion reduced all species of plasma AcylCN but this reduction was blunted in T2DM. Plasma long-chain AcylCN species are increased in obesity and T2DM, suggesting that more fatty acids can enter mitochondria. In T2DM, many shorter species accumulate, suggesting that they have a generalized complex oxidation defect.
Collapse
Affiliation(s)
- Stephanie J. Mihalik
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Bret H. Goodpaster
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - David E. Kelley
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Jerry Vockley
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Human Genetics, Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Frederico G.S. Toledo
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - James P. DeLany
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
15
|
Hall D, Poussin C, Velagapudi VR, Empsen C, Joffraud M, Beckmann JS, Geerts AE, Ravussin Y, Ibberson M, Oresic M, Thorens B. Peroxisomal and microsomal lipid pathways associated with resistance to hepatic steatosis and reduced pro-inflammatory state. J Biol Chem 2010; 285:31011-23. [PMID: 20610391 DOI: 10.1074/jbc.m110.127159] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Accumulation of fat in the liver increases the risk to develop fibrosis and cirrhosis and is associated with development of the metabolic syndrome. Here, to identify genes or gene pathways that may underlie the genetic susceptibility to fat accumulation in liver, we studied A/J and C57Bl/6 mice that are resistant and sensitive to diet-induced hepatosteatosis and obesity, respectively. We performed comparative transcriptomic and lipidomic analysis of the livers of both strains of mice fed a high fat diet for 2, 10, and 30 days. We found that resistance to steatosis in A/J mice was associated with the following: (i) a coordinated up-regulation of 10 genes controlling peroxisome biogenesis and β-oxidation; (ii) an increased expression of the elongase Elovl5 and desaturases Fads1 and Fads2. In agreement with these observations, peroxisomal β-oxidation was increased in livers of A/J mice, and lipidomic analysis showed increased concentrations of long chain fatty acid-containing triglycerides, arachidonic acid-containing lysophosphatidylcholine, and 2-arachidonylglycerol, a cannabinoid receptor agonist. We found that the anti-inflammatory CB2 receptor was the main hepatic cannabinoid receptor, which was highly expressed in Kupffer cells. We further found that A/J mice had a lower pro-inflammatory state as determined by lower plasma levels and IL-1β and granulocyte-CSF and reduced hepatic expression of their mRNAs, which were found only in Kupffer cells. This suggests that increased 2-arachidonylglycerol production may limit Kupffer cell activity. Collectively, our data suggest that genetic variations in the expression of peroxisomal β-oxidation genes and of genes controlling the production of an anti-inflammatory lipid may underlie the differential susceptibility to diet-induced hepatic steatosis and pro-inflammatory state.
Collapse
Affiliation(s)
- Diana Hall
- Department of Physiology and Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Seifert EL, Bézaire V, Estey C, Harper ME. Essential role for uncoupling protein-3 in mitochondrial adaptation to fasting but not in fatty acid oxidation or fatty acid anion export. J Biol Chem 2008; 283:25124-25131. [PMID: 18628202 DOI: 10.1074/jbc.m803871200] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Uncoupling protein-3 (UCP3) is a mitochondrial inner membrane protein expressed most abundantly in skeletal muscle and to a lesser extent in heart and brown adipose tissue. Evidence supports a role for UCP3 in fatty acid oxidation (FAO); however, the underlying mechanism has not been explored. In 2001 we proposed a role for UCP3 in fatty acid export, leading to higher FAO rates (Himms-Hagen, J., and Harper, M. E. (2001) Exp. Biol. Med. (Maywood) 226, 78-84). Specifically, this widely held hypothesis states that during elevated FAO rates, UCP3 exports fatty acid anions, thereby maintaining mitochondrial co-enzyme A availability; reactivation of exported fatty acid anions would ultimately enable increased FAO. Here we tested mechanistic aspects of this hypothesis as well as its functional implications, namely increased FAO rates. Using complementary mechanistic approaches in mitochondria from wild-type and Ucp3(-/-) mice, we find that UCP3 is not required for FAO regardless of substrate type or supply rate covering a 20-fold range. Fatty acid anion export and reoxidation during elevated FAO, although present in skeletal muscle mitochondria, are independent of UCP3 abundance. Interestingly, UCP3 was found to be necessary for the fasting-induced enhancement of FAO rate and capacity, possibly via mitigated mitochondrial oxidative stress. Thus, although our observations indicate that UCP3 can impact FAO rates, the mechanistic basis is not via an integral function for UCP3 in the FAO machinery. Overall our data indicate a function for UCP3 in mitochondrial adaptation to perturbed cellular energy balance and integrate previous observations that have linked UCP3 to reduced oxidative stress and FAO.
Collapse
Affiliation(s)
- Erin L Seifert
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Véronic Bézaire
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Carmen Estey
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
| |
Collapse
|
17
|
Hypolipidaemic effects of fenofibrate and fasting in the herbivorous grass carp ( Ctenopharyngodon idella) fed a high-fat diet. Br J Nutr 2008; 100:1200-12. [PMID: 18445306 DOI: 10.1017/s0007114508986840] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omnivorous mammals may also apply to herbivorous fish. Grass carp (Ctenopharyngodon idella) fed a high-fat (8 %) diet exhibited a marked increase in blood lipids and body fat after 6 weeks. They were then treated with fenofibrate (100 mg/kg body weight) in the same high-fat diet for 2 weeks, followed by fasting for 1 week. Plasma lipid concentration, body fat amount, fatty acid composition, plasma thiobarbituric acid-reactive substances and some parameters related to hepatic fatty acid oxidation were measured, and liver samples were stained for histological examination. Fenofibrate treatment decreased TAG and cholesterol concentrations in plasma, total lipids of the whole body and liver, and EPA and DHA contents in tissues. Further, a mobilisation of mesenteric fat concomitant with an increase in hepatic peroxisomal fatty acid oxidation and lipid peroxidation was observed. Compared with fenofibrate treatment, fasting decreased body weight and plasma TAG, but not plasma cholesterol. It also reduced the fat content of the whole body and increased the EPA and DHA contents in the liver and other tissues. Fatty acid oxidation was stimulated by fasting in mitochondria, but not in peroxisomes. These data suggest that fenofibrate and fasting regulate the lipid metabolism in grass carp through different metabolic pathways. The grass carp is moderately responsive to a fibrate derivative in comparison with the well-known excess responsiveness of the rat model, and so it could be used for the study of lipid abnormalities as a herbivorous model.
Collapse
|
18
|
Benton CR, Holloway GP, Campbell SE, Yoshida Y, Tandon NN, Glatz JFC, Luiken JJJFP, Spriet LL, Bonen A. Rosiglitazone increases fatty acid oxidation and fatty acid translocase (FAT/CD36) but not carnitine palmitoyltransferase I in rat muscle mitochondria. J Physiol 2008; 586:1755-66. [PMID: 18238811 DOI: 10.1113/jphysiol.2007.146563] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) alter the expression of genes involved in regulating lipid metabolism. Rosiglitazone, a PPARgamma agonist, induces tissue-specific effects on lipid metabolism; however, its mode of action in skeletal muscle remains unclear. Since fatty acid translocase (FAT/CD36) was recently identified as a possible regulator of skeletal muscle fatty acid transport and mitochondrial fatty acid oxidation, we examined in this tissue the effects of rosiglitazone infusion (7 days, 1 mg day(-1)) on FAT/CD36 mRNA and protein, its plasmalemmal content and fatty acid transport. In addition, in isolated subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria we examined rates of fatty acid oxidation, FAT/CD36 and carnitine palmitoyltransferase I (CPTI) protein, and CPTI and beta-hydroxyacyl CoA dehydrogenase (beta-HAD) activities. Rosiglitazone did not alter FAT/CD36 mRNA or protein expression, FAT/CD36 plasmalemmal content, or the rate of fatty acid transport into muscle (P > 0.05). In contrast, rosiglitazone increased the rates of fatty acid oxidation in both SS (+21%) and IMF mitochondria (+36%). This was accompanied by concomitant increases in FAT/CD36 in subsarcolemmal (SS) (+43%) and intermyofibrillar (IMF) mitochondria (+46%), while SS and IMF CPTI protein content, and CPTI submaximal and maximal activities (P > 0.05) were not altered. Similarly, citrate synthase (CS) and beta-HAD activities were also not altered by rosiglitazone in SS and IMF mitochondria (P > 0.05). These studies provide another example whereby changes in mitochondrial fatty oxidation are associated with concomitant changes in mitochondrial FAT/CD36 independent of any changes in CPTI. Moreover, these studies identify for the first time a mechanism by which rosiglitazone stimulates fatty acid oxidation in skeletal muscle, namely the chronic, subcellular relocation of FAT/CD36 to mitochondria.
Collapse
Affiliation(s)
- Carley R Benton
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Benton CR, Nickerson JG, Lally J, Han XX, Holloway GP, Glatz JFC, Luiken JJFP, Graham TE, Heikkila JJ, Bonen A. Modest PGC-1alpha overexpression in muscle in vivo is sufficient to increase insulin sensitivity and palmitate oxidation in subsarcolemmal, not intermyofibrillar, mitochondria. J Biol Chem 2007; 283:4228-40. [PMID: 18079123 DOI: 10.1074/jbc.m704332200] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PGC-1alpha overexpression in skeletal muscle, in vivo, has yielded disappointing and unexpected effects, including disrupted cellular integrity and insulin resistance. These unanticipated results may stem from an excessive PGC-1alpha overexpression in transgenic animals. Therefore, we examined the effects of a modest PGC-1alpha overexpression in a single rat muscle, in vivo, on fuel-handling proteins and insulin sensitivity. We also examined whether modest PGC-1alpha overexpression selectively targeted subsarcolemmal (SS) mitochondrial proteins and fatty acid oxidation, because SS mitochondria are metabolically more plastic than intermyofibrillar (IMF) mitochondria. Among metabolically heterogeneous rat hindlimb muscles, PGC-1alpha was highly correlated with their oxidative fiber content and with substrate transport proteins (GLUT4, FABPpm, and FAT/CD36) and mitochondrial proteins (COXIV and mTFA) but not with insulin-signaling proteins (phosphatidylinositol 3-kinase, IRS-1, and Akt2), nor with 5'-AMP-activated protein kinase, alpha2 subunit, and HSL. Transfection of PGC-1alpha into the red (RTA) and white tibialis anterior (WTA) compartments of the tibialis anterior muscle increased PGC-1alpha protein by 23-25%. This also induced the up-regulation of transport proteins (FAT/CD36, 35-195%; GLUT4, 20-32%) and 5'-AMP-activated protein kinase, alpha2 subunit (37-48%), but not other proteins (FABPpm, IRS-1, phosphatidylinositol 3-kinase, Akt2, and HSL). SS and IMF mitochondrial proteins were also up-regulated, including COXIV (15-75%), FAT/CD36 (17-30%), and mTFA (15-85%). PGC-1alpha overexpression also increased palmitate oxidation in SS (RTA, +116%; WTA, +40%) but not in IMF mitochondria, and increased insulin-stimulated phosphorylation of AKT2 (28-43%) and rates of glucose transport (RTA, +20%; WTA, +38%). Thus, in skeletal muscle in vivo, a modest PGC-1alpha overexpression up-regulated selected plasmalemmal and mitochondrial fuel-handling proteins, increased SS (not IMF) mitochondrial fatty acid oxidation, and improved insulin sensitivity.
Collapse
Affiliation(s)
- Carley R Benton
- Departments of Kinesiology and Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Noland RC, Woodlief TL, Whitfield BR, Manning SM, Evans JR, Dudek RW, Lust RM, Cortright RN. Peroxisomal-mitochondrial oxidation in a rodent model of obesity-associated insulin resistance. Am J Physiol Endocrinol Metab 2007; 293:E986-E1001. [PMID: 17638705 DOI: 10.1152/ajpendo.00399.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxisomal oxidation yields metabolites that are more efficiently utilized by mitochondria. This is of potential clinical importance because reduced fatty acid oxidation is suspected to promote excess lipid accumulation in obesity-associated insulin resistance. Our purpose was to assess peroxisomal contributions to mitochondrial oxidation in mixed gastrocnemius (MG), liver, and left ventricle (LV) homogenates from lean and fatty (fa/fa) Zucker rats. Results indicate that complete mitochondrial oxidation (CO(2) production) using various lipid substrates was increased approximately twofold in MG, unaltered in LV, and diminished approximately 50% in liver of fa/fa rats. In isolated mitochondria, malonyl-CoA inhibited CO(2) production from palmitate 78%, whereas adding isolated peroxisomes reduced inhibition to 21%. These data demonstrate that peroxisomal products may enter mitochondria independently of CPT I, thus providing a route to maintain lipid disposal under conditions where malonyl-CoA levels are elevated, such as in insulin-resistant tissues. Peroxisomal metabolism of lignoceric acid in fa/fa rats was elevated in both liver and MG (LV unaltered), but peroxisomal product distribution varied. A threefold elevation in incomplete oxidation was solely responsible for increased hepatic peroxisomal oxidation (CO(2) unaltered). Alternatively, only CO(2) was detected in MG, indicating that peroxisomal products were exclusively partitioned to mitochondria for complete lipid disposal. These data suggest tissue-specific destinations for peroxisome-derived products and emphasize a potential role for peroxisomes in skeletal muscle lipid metabolism in the obese, insulin-resistant state.
Collapse
Affiliation(s)
- Robert C Noland
- Department of Physiology, East Carolina University, Greenville, NC 27858, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Degrace P, Demizieux L, Du ZY, Gresti J, Caverot L, Djaouti L, Jourdan T, Moindrot B, Guilland JC, Hocquette JF, Clouet P. Regulation of Lipid Flux between Liver and Adipose Tissue during Transient Hepatic Steatosis in Carnitine-depleted Rats. J Biol Chem 2007; 282:20816-26. [PMID: 17496329 DOI: 10.1074/jbc.m611391200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rats with carnitine deficiency due to trimethylhydrazinium propionate (mildronate) administered at 80 mg/100 g body weight per day for 10 days developed liver steatosis only upon fasting. This study aimed to determine whether the transient steatosis resulted from triglyceride accumulation due to the amount of fatty acids preserved through impaired fatty acid oxidation and/or from up-regulation of lipid exchange between liver and adipose tissue. In liver, mildronate decreased the carnitine content by approximately 13-fold and, in fasted rats, lowered the palmitate oxidation rate by 50% in the perfused organ, increased 9-fold the triglyceride content, and doubled the hepatic very low density lipoprotein secretion rate. Concomitantly, triglyceridemia was 13-fold greater than in controls. Hepatic carnitine palmitoyltransferase I activity and palmitate oxidation capacities measured in vitro were increased after treatment. Gene expression of hepatic proteins involved in fatty acid oxidation, triglyceride formation, and lipid uptake were all increased and were associated with increased hepatic free fatty acid content in treated rats. In periepididymal adipose tissue, mildronate markedly increased lipoprotein lipase and hormone-sensitive lipase activities in fed and fasted rats, respectively. On refeeding, carnitine-depleted rats exhibited a rapid decrease in blood triglycerides and free fatty acids, then after approximately 2 h, a marked drop of liver triglycerides and a progressive decrease in liver free fatty acids. Data show that up-regulation of liver activities, peripheral lipolysis, and lipoprotein lipase activity were likely essential factors for excess fat deposit and release alternately occurring in liver and adipose tissue of carnitine-depleted rats during the fed/fasted transition.
Collapse
Affiliation(s)
- Pascal Degrace
- UMR 866 INSERM-UB, Equipe Physiopathologie des dyslipidémies, Faculté des Sciences, 21000 Dijon, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Du ZY, Clouet P, Zheng WH, Degrace P, Tian LX, Liu YJ. Biochemical hepatic alterations and body lipid composition in the herbivorous grass carp (Ctenopharyngodon idella) fed high-fat diets. Br J Nutr 2007; 95:905-15. [PMID: 16611380 DOI: 10.1079/bjn20061733] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High-fat diets may have favourable effects on growth of some carnivorous fish because of the protein-sparing effect of lipids, but high-fat diets also exert some negative impacts on flesh quality. The goal of the study was therefore to determine the effects of fat-enriched diets in juvenile grass carp (Ctenopharyngodon idella) as a typical herbivorous fish on growth and possible lipid metabolism alterations. Three isonitrogenous diets containing 2, 6 or 10% of a mixture of lard, maize oil and fish oil (1:1:1, by weight) were applied to fish for 8 weeks in a recirculation system. Data show that feeding diets with increasing lipid levels resulted in lowered feed intake, decreased growth and feed efficiency, and increased mesenteric fat tissue weight. Concomitantly, alteration of lipoprotein synthesis and greater level of lipid peroxidation were apparent in blood. In liver, muscle and mesenteric fat tissue, the percentages of α-linolenic acid and DHA were significantly increased or tended to increase with higher dietary lipid levels. Biochemical activity measurements performed on liver showed that, with the increase in dietary lipid level, there was a decrease in both mitochondrial and peroxisomal fatty acid oxidation capacities, which might contribute, at least in part, to the specific accumulation of α-linolenic acid and DHA into cells more active in membrane building. On the whole, grass carp have difficulty in energetically utilising excess dietary fat, especially when enriched in n−3 PUFA that are susceptible to peroxidation.
Collapse
Affiliation(s)
- Zhen-Yu Du
- Institute of Aquatic Economic Animals, School of Life Sciences, Guangzhou, China
| | | | | | | | | | | |
Collapse
|
23
|
Sherratt HS, Watmough NJ, Johnson MA, Turnbull DM. Methods for study of normal and abnormal skeletal muscle mitochondria. METHODS OF BIOCHEMICAL ANALYSIS 2006; 33:243-335. [PMID: 3282151 DOI: 10.1002/9780470110546.ch6] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
24
|
Degrace P, Moindrot B, Mohamed I, Gresti J, Du ZY, Chardigny JM, Sébédio JL, Clouet P. Upregulation of liver VLDL receptor and FAT/CD36 expression in LDLR-/- apoB100/100 mice fed trans-10,cis-12 conjugated linoleic acid. J Lipid Res 2006; 47:2647-55. [PMID: 16957181 DOI: 10.1194/jlr.m600140-jlr200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study explores the mechanisms responsible for the fatty liver setup in mice fed trans-10,cis-12 conjugated linoleic acid (t10c12 CLA), hypothesizing that an induction of low density lipoprotein receptor (LDLR) expression is associated with lipid accumulation. To this end, the effects of t10c12 CLA treatment on lipid parameters, serum lipoproteins, and expression of liver lipid receptors were measured in LDLR(-/-) apoB(100/100) mice as a model of human familial hypercholesterolemia itself depleted of LDLR. Mice were fed t10c12 CLA over 2 or 4 weeks. We first observed that the treatment induced liver steatosis, even in the absence of LDLR. Mice treated for 2 weeks exhibited hypertriglyceridemia with high levels of VLDL and HDL, whereas a 4 week treatment inversely induced a reduction of serum triglycerides (TGs), essentially through a decrease in VLDL levels. In the absence of LDLR, the mRNA levels of other proteins, such as VLDL receptor, lipoprotein lipase, and fatty acid translocase, usually not expressed in the liver, were upregulated, suggesting their involvement in the steatosis setup and lipoprotein clearance. The data also suggest that the TG-lowering effect induced by t10c12 CLA treatment was attributable to both the reduction of circulating free fatty acids in response to the severe lipoatrophy and the high capacity of liver to clear off plasma lipids.
Collapse
Affiliation(s)
- Pascal Degrace
- Unité Propre de Recherche de l'Enseignement Supérieur, Lipides et Nutrition EA2422, Faculté des Sciences Gabriel, Université de Bourgogne, 21000 Dijon, France.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Du ZY, Demizieux L, Degrace P, Gresti J, Moindrot B, Liu YJ, Tian LX, Cao JM, Clouet P. Alteration of 20:5n-3 and 22:6n-3 fat contents and liver peroxisomal activities in fenofibrate-treated rainbow trout. Lipids 2005; 39:849-55. [PMID: 15669760 DOI: 10.1007/s11745-004-1306-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Fish easily accumulate n-3 PUFA of exogenous origin, but the underlying mechanisms are not well established in the whole animal. This study was undertaken to investigate whether this feature was physiologically associated with mitochondrial and peroxisomal capacities that differentially affect FA oxidation. For this purpose, peroxisomal FA oxidation was increased by treating rainbow trout with fenofibrate, which strongly stimulates the peroxisome proliferator-activated receptor-a in rodents. Diets containing EPA and DHA, with or without fenofibrate added, were administered to male trout for 12 d. After treatment, neither liver hypertrophy nor accumulation of fat was apparent within the liver and muscle cells. However, fenofibrate treatment decreased the contents of EPA and DHA in the liver, white muscle, and intraperitoneal fat tissue, which represented (per whole body) at least 280 mg less than in controls. Carnitine-dependent palmitate oxidation rates, expressed per gram of liver, were slightly increased by fenofibrate when measured from tissue homogenates and were unchanged when calculated from isolated mitochondria, relative to control fish. The treatment altered neither carnitine palmitoyltransferase I activity rates, expressed per gram of liver, nor the sensitivity of the enzyme to malonyl-CoA inhibition, but did increase the malonyl-CoA content (+45%). Meanwhile, fenofibrate increased (by about 30%) the peroxisome-related activities, i.e., catalase, carnitine-independent palmitate oxidation, acyl-CoA oxidase, and the peroxisomal FA-oxidizing system, relative to the control group. The data strongly suggest that the induction of peroxisomal activities, some of which being able to oxidize very long chain FA, was responsible for the lower contents of EPA and DHA in the body lipids of fenofibrate-treated trout.
Collapse
Affiliation(s)
- Zhen-yu Du
- Université de Bourgogne, 21000 Dijon, France
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Degrace P, Demizieux L, Gresti J, Tsoko M, André A, Demaison L, Clouet P. Fatty acid oxidation and related gene expression in heart depleted of carnitine by mildronate treatment in the rat. Mol Cell Biochem 2004; 258:171-82. [PMID: 15030182 DOI: 10.1023/b:mcbi.0000012853.20116.06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The metabolic and genic effects induced by a 20-fold lowering of carnitine content in the heart were studied in mildronate-treated rats. In the perfused heart, the proportion of palmitate taken up then oxidized was 5-10% lower, while the triacylglycerol (TAG) formation was 100% greater than in controls. The treatment was shown to increase the maximal capacity of heart homogenates to oxidize palmitate, the mRNA level of carnitine palmitoyltransferase I (CPT-I) isoforms, the specific activity of CPT-I in subsarcolemmal mitochondria and the total carnitine content of isolated mitochondria. Concomitantly, the increased mRNA expression of lipoprotein lipase, fatty acid translocase and enzymes of TAG synthesis was associated with a 5- and 2-times increase in serum TAG and free fatty acid contents, respectively. The compartmentation of carnitine at its main functional location was expected to allow the increased CPT-I activity to ensure in vivo correct fatty acid oxidation rates. All the inductions related to fatty acid transport, oxidation and esterification most likely stem from the abundance of blood lipids providing cardiomyocytes with more fatty acids.
Collapse
Affiliation(s)
- Pascal Degrace
- UPRES Lipides et Nutrition EA2422, Faculté des Sciences Gabriel, Université de Bourgogne, Dijon, France
| | | | | | | | | | | | | |
Collapse
|
27
|
Campbell SE, Tandon NN, Woldegiorgis G, Luiken JJFP, Glatz JFC, Bonen A. A novel function for fatty acid translocase (FAT)/CD36: involvement in long chain fatty acid transfer into the mitochondria. J Biol Chem 2004; 279:36235-41. [PMID: 15161924 DOI: 10.1074/jbc.m400566200] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fatty acid translocase (FAT)/CD36 is a long chain fatty acid transporter present at the plasma membrane, as well as in intracellular pools of skeletal muscle. In this study, we assessed the unexpected presence of FAT/CD36 in both subsarcolemmal and intermyofibril fractions of highly purified mitochondria. Functional assessments demonstrated that the mitochondria could bind (14)C-labeled palmitate, but could only oxidize it in the presence of carnitine. However, the addition of sulfo-N-succinimidyl oleate, a known inhibitor of FAT/CD36, resulted in an 87 and 85% reduction of palmitate oxidation in subsarcolemmal and intermyofibril fractions, respectively. Further studies revealed that maximal carnitine palmitoyltransferase I (CPTI) activity in vitro was inhibited by succinimidyl oleate (42 and 48% reduction). Interestingly, CPTI immunoprecipitated with FAT/CD36, indicating a physical pairing. Tissue differences in mitochondrial FAT/CD36 protein follow the same pattern as the capacity for fatty acid oxidation (heart >> red muscle > white muscle). Additionally, chronic stimulation of hindlimb muscles (7 days) increased FAT/CD36 expression and also resulted in a concomitant increase in mitochondrial FAT/CD36 content (46 and 47% increase). Interestingly, with acute electrical stimulation of hindlimb muscles (30 min), FAT/CD36 expression was not altered, but there was an increase in the mitochondrial content of FAT/CD36 compared with the non-stimulated control limb (35 and 37% increase). Together, these data suggest a role for FAT/CD36 in mitochondrial long chain fatty acid uptake and demonstrate system flexibility to match FAT/CD36 mitochondrial content with an increased capacity for fatty acid oxidation, possibly involving translocation of FAT/CD36 to the mitochondria.
Collapse
Affiliation(s)
- Shannon E Campbell
- Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | | | | | | | | | |
Collapse
|
28
|
Degrace P, Demizieux L, Gresti J, Chardigny JM, Sébédio JL, Clouet P. Hepatic steatosis is not due to impaired fatty acid oxidation capacities in C57BL/6J mice fed the conjugated trans-10,cis-12-isomer of linoleic acid. J Nutr 2004; 134:861-7. [PMID: 15051838 DOI: 10.1093/jn/134.4.861] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Decreased body fat mass and liver steatosis have been reported in mice fed diets containing the conjugated linoleic acid trans-10,cis-12-C18:2 (CLA2), but not in those fed diets containing cis-9,trans-11-C18:2 (CLA1). Because the decrease in fatty acid (FA) oxidation may cause fat accumulation, we questioned whether the effects of both CLAs on enzyme activities and mRNA expression were related to liver FA oxidation. To address this question, 7-wk-old male C57BL/6J mice were fed for 4 wk a diet supplemented with 1% CLA1, CLA2, or cis-9-C18:1 (control) esterified as triacylglycerols. In CLA2-fed mice, the proportions of CLA2 in the total FA of liver lipids were substantially lower than those of CLA1 in mice fed CLA1. The mitochondrial protein content per total liver was about 56% greater in CLA2-fed mice than in CLA1-fed mice and controls. Mitochondrial carnitine palmitoyltransferase I (CPT I) and carnitine-dependent palmitate oxidation activities were also significantly greater in CLA2-fed mice than in the two other groups. The amounts of malonyl-CoA per gram of liver and the sensitivity of CPT I to malonyl-CoA inhibition were greater in both groups of CLA-fed mice than in the controls. L-CPT I mRNA expression doubled in CLA2-fed mice and was 3 and 2 times greater for M-CPT I in the CLA1 and CLA2 groups, respectively, compared with controls. Peroxisomal FA oxidation-related activities and acyl-CoA oxidase mRNA expression were increased in CLA1-fed mice, and to a larger extent in CLA2-fed mice, relative to controls. These data indicate that FA oxidation capacities were increased in mice fed CLA2, but were likely depressed in vivo through malonyl-CoA inhibition.
Collapse
Affiliation(s)
- P Degrace
- UPRES Lipides et Nutrition EA2422, Faculté des Sciences Gabriel, Université de Bourgogne, 21000 Dijon, France
| | | | | | | | | | | |
Collapse
|
29
|
Demizieux L, Degrace P, Gresti J, Loreau O, Noël JP, Chardigny JM, Sébédio JL, Clouet P. Conjugated linoleic acid isomers in mitochondria: evidence for an alteration of fatty acid oxidation. J Lipid Res 2002; 43:2112-22. [PMID: 12454273 DOI: 10.1194/jlr.m200170-jlr200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The beneficial effects exerted by low amounts of conjugated linoleic acids (CLA) suggest that CLA are maximally conserved and raise the question about their mitochondrial oxidizability. Cis-9,trans-11-C(18:2) (CLA1) and trans-10,cis-12-C(18:2) (CLA2) were compared to cis-9,cis-12-C(18:2) (linoleic acid; LA) and cis-9-C(16:1) (palmitoleic acid; PA), as substrates for total fatty acid (FA) oxidation and for the enzymatic steps required for the entry of FA into rat liver mitochondria. Oxygen consumption rate was lowest when CLA1 was used as a substrate with that on CLA2 being intermediate between it and the respiration on LA and PA. The order of the radiolabeled FA oxidation rate was PA >> LA > CLA2 > CLA1. Transesterification to acylcarnitines of the octadecadienoic acids were similar, while uptake across inner membranes of CLA1 and, to a lesser extent, of CLA2 was greater than that of LA or PA. Prior oxidation of CLA1 or CLA2 made re-isolated mitochondria much less capable of oxidising PA or LA under carnitine-dependent conditions, but without altering the carnitine-independent oxidation of octanoic acid. Therefore, the CLA studied appeared to be both poorly oxidizable and capable of interfering with the oxidation of usual FA at a step close to the beginning of the beta-oxidative cycle.
Collapse
Affiliation(s)
- Laurent Demizieux
- UPRES Lipides et Nutrition EA2422, Faculté des Sciences Gabriel, Université de Bourgogne, 21000 Dijon, France
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Veerkamp JH, Zimmerman AW. Fatty acid-binding proteins of nervous tissue. J Mol Neurosci 2001; 16:133-42; discussion 151-7. [PMID: 11478368 DOI: 10.1385/jmn:16:2-3:133] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2000] [Accepted: 11/01/2000] [Indexed: 12/16/2022]
Abstract
Fatty acid-binding proteins (FABPs) are cytosolic 14-15 kDa proteins, which are supposed to be involved in fatty acid (FA) uptake, transport, and targeting. They may modulate FA concentration and in this way influence function of enzymes, membranes, ion channels and receptors, and gene expression and cellular growth and differentiation. Nine FABP types can be discerned with a specific tissue distribution. In spite of 30-70% amino acid sequence identity, they have a similar tertiary, beta-clam structure in which the FA is bound. Nervous tissue contains four FABP types with a distinct spatio-temporal distribution. Myelin (M)-FABP is only present in the peripheral nerves, brain (B)-FABP and epidermal (E)-FABP mainly in glial cells and neurons, respectively of pre- and perinatal brain, and heart (H)-FABP in adult brain. Possible functions of FABPs in the nervous system are discussed. Binding studies with a range of physiological FA showed no large differences between recombinant proteins of the four human FABP types in binding specificity and affinity, also not for polyunsaturated FA (PUFA). The transfer of FA from fixed liposomes to mitochondria was similarly promoted by the four types. A marked difference in conformational stability was observed with H-FABP > B-FABP > M-FABP > E-FABP. Surface epitopes of H-FABP showed reaction with anti-B-FABP antibodies, but no other cross-reactivity of FABP type and heterologous antibodies was observed. The functional significance of the distinct spatio-temporal pattern of the four FABP types remains to be elucidated.
Collapse
Affiliation(s)
- J H Veerkamp
- Department of Biochemistry, University Medical Center St. Radboud, Nijmegen, The Netherlands.
| | | |
Collapse
|
31
|
Morio B, Hocquette JF, Montaurier C, Boirie Y, Bouteloup-Demange C, McCormack C, Fellmann N, Beaufrère B, Ritz P. Muscle fatty acid oxidative capacity is a determinant of whole body fat oxidation in elderly people. Am J Physiol Endocrinol Metab 2001; 280:E143-9. [PMID: 11120668 DOI: 10.1152/ajpendo.2001.280.1.e143] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In sedentary elderly people, a reduced muscle fatty acid oxidative capacity (MFOC) may explain a decrease in whole body fat oxidation. Eleven sedentary and seven regularly exercising subjects (65.6 +/- 4. 5 yr) were characterized for their aerobic fitness [maximal O(2) uptake (VO(2 max))/kg fat free mass (FFM)] and their habitual daily physical activity level [free-living daily energy expenditure divided by sleeping metabolic rate (DEE(FLC)/SMR)]. MFOC was determined by incubating homogenates of vastus lateralis muscle with [1-(14)C]palmitate. Whole body fat oxidation was measured by indirect calorimetry over 24 h. MFOC was 40.4 +/- 14.7 and 44.3 +/- 16.3 nmol palmitate. g wet tissue(-1). min(-1) in the sedentary and regularly exercising individuals, respectively (P = nonsignificant). MFOC was positively correlated with DEE(FLC)/SMR (r = 0.58, P < 0. 05) but not with VO(2 max)/kg FFM (r = 0.35, P = nonsignificant). MFOC was the main determinant of fat oxidation during all time periods including physical activity. Indeed, MFOC explained 19.7 and 30.5% of the variance in fat oxidation during walking and during the alert period, respectively (P < 0.05). Furthermore, MFOC explained 23.0% of the variance in fat oxidation over 24 h (P < 0.05). It was concluded that, in elderly people, MFOC may be influenced more by overall daily physical activity than by regular exercising. MFOC is a major determinant of whole body fat oxidation during physical activities and, consequently, over 24 h.
Collapse
Affiliation(s)
- B Morio
- Laboratoire de Nutrition Humaine, Université d'Auvergne, Centre de Recherche en Nutrition Humaine d'Auvergne, 63009 Clermont-Ferrand, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Veerkamp JH, Van Moerkerk And HT, Zimmerman AW. Effect of fatty acid-binding proteins on intermembrane fatty acid transport studies on different types and mutant proteins. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5959-66. [PMID: 10998056 DOI: 10.1046/j.1432-1327.2000.01665.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Liposomes of different charge fixed to nitrocellulose filters were used to study the transfer of fatty acids to rat heart or liver mitochondria in the presence of fatty acid-binding protein (FABP) or albumin. [14C]Palmitate oxidation was used as a parameter. Different FABP types and heart FABP mutants were tested. The charge of the liposomes did not influence the solubilization and mitochondrial oxidation of palmitate without FABP and the amount of solubilized palmitate in the presence of FABP. Mitochondria did not show a preference for oxidation of FABP-bound palmitate over their tissue-specific FABP type. All FABP types increased palmitate oxidation by heart and liver mitochondria with neutral, positive and negative liposomes by 2.5-fold, 3.2-fold and twofold, respectively. Ileal lipid-binding protein and H-FABP mutants that do not bind fatty acid had no effect. Other H-FABP mutants had different effects, dependent on the site of mutation. The effect of albumin was similar to, but not dependent on, liposome charge. The ionic strength had only a slight effect. In conclusion, the transfer of palmitate from liposomal membranes to mitochondria was increased by all FABP types to a similar extent. The membrane charge had a large effect in contrast to the origin of the mitochondria.
Collapse
Affiliation(s)
- J H Veerkamp
- Department of Biochemistry, University of Nijmegen, The Netherlands.
| | | | | |
Collapse
|
33
|
Grum DE, Hansen LR, Drackley JK. Peroxisomal beta-oxidation of fatty acids in bovine and rat liver. Comp Biochem Physiol B Biochem Mol Biol 1994; 109:281-92. [PMID: 7553346 DOI: 10.1016/0305-0491(94)90012-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Hepatic peroxisomal beta-oxidation rates were compared in liver homogenates from cows and rats during different nutritional and physiological states. Peroxisomal oxidation in liver homogenates from cows represented 50% and 77% of the total capacity for the initial cycle of beta-oxidation of palmitate and octanoate, respectively, but only 26% and 65% for rats. Lactation or food deprivation did not alter rates of hepatic peroxisomal beta-oxidation of palmitate or octanoate in cows. Fasting and clofibrate treatment increased rates of total and peroxisomal beta-oxidation of palmitate and octanoate in rat liver.
Collapse
Affiliation(s)
- D E Grum
- Department of Animal Sciences, University of Illinois, Urbana 61801, USA
| | | | | |
Collapse
|
34
|
Chu C, Mao LF, Schulz H. Estimation of peroxisomal beta-oxidation in rat heart by a direct assay of acyl-CoA oxidase. Biochem J 1994; 302 ( Pt 1):23-9. [PMID: 8068010 PMCID: PMC1137186 DOI: 10.1042/bj3020023] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The contribution of peroxisomes to palmitate beta-oxidation in rat heart was estimated by either inhibiting mitochondrial beta-oxidation or measuring the activity of acyl-CoA oxidase. When respiratory inhibitors such as KCN or antimycin plus rotenone, or inhibitors of mitochondrial fatty acid uptake such as 2-tetradecylglycidic acid or 2-bromopalmitate, were used, degrees of inhibitions ranging from 24% to 87% were observed for palmitate beta-oxidation by a rat heart homogenate. Although the oxidation of palmitoyl-L-carnitine by coupled rat heart mitochondria was almost completely (94%) inhibited by KCN, the inhibition by antimycin plus rotenone was incomplete (77%) and was stimulated by L-carnitine. A direct assay of acyl-CoA oxidase, based on the spectrophotometric measurement at 300 nm of 2,4-decadienoyl-CoA formation from 4-trans-decenoyl-CoA, was evaluated with the aim of obtaining reliable values for the activity of this enzyme, which is presumed to catalyse the rate-limiting step of peroxisomal beta-oxidation. Activities determined by use of this assay were much higher than activities obtained by a coupled assay [Small, Burdett and Connock (1985) Biochem. J. 227, 205-210] commonly used to measure the activity of acyl-CoA oxidase. However, both methods yielded the same relative activities with different tissue homogenates. Based on an estimated palmitoyl-CoA oxidase activity of 0.3 nmol/min per mg of protein, the contribution of peroxisomes to palmitate beta-oxidation in a rat heart homogenate would optimally be 4%, and most likely is several-fold lower.
Collapse
Affiliation(s)
- C Chu
- Department of Chemistry, City College of City University of New York, NY 10031
| | | | | |
Collapse
|
35
|
Pourfarzam M, Bartlett K. Skeletal muscle mitochondrial beta-oxidation of dicarboxylates. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1141:81-9. [PMID: 8435437 DOI: 10.1016/0005-2728(93)90192-i] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
(1) The oxidation of [U-14C]hexadecanedionoyl-mono-CoA by rat skeletal muscle mitochondrial fractions is carnitine dependent and is inhibited by cyanide. (2) [U-14C]hexadecanedionoyl-mono-CoA was oxidised at a rate 8% of that of [U-14C]hexadecanoyl-CoA. (3) Oxidations were saturable and no substrate inhibition was observed. (4) We demonstrate the formation of dicarboxylyl-mono-CoA esters and the corresponding carnitine derivatives. (5) We conclude that, although skeletal muscle mitochondria are capable of the beta-oxidation of dicarboxylic acids, this is unlikely to be of great physiological significance.
Collapse
Affiliation(s)
- M Pourfarzam
- Department of Child Health, Medical School, University of Newcastle upon Tyne, UK
| | | |
Collapse
|
36
|
Eaton S, Bhuiyan AK, Kler RS, Turnbull DM, Bartlett K. Intramitochondrial control of the oxidation of hexadecanoate in skeletal muscle. A study of the acyl-CoA esters which accumulate during rat skeletal-muscle mitochondrial beta-oxidation of [U-14C]hexadecanoate and [U-14C]hexadecanoyl-carnitine. Biochem J 1993; 289 ( Pt 1):161-8. [PMID: 8424753 PMCID: PMC1132144 DOI: 10.1042/bj2890161] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
1. We describe the acyl-CoA and acyl-carnitine esters which arise from the incubation of well-coupled State 3 rat skeletal-muscle mitochondrial fractions with [U-14C]hexadecanoate and [U-14C]hexadecanoyl-carnitine. 2. Acyl-CoA ester intermediates of chain length 16, 14, 12, 10 and 8 carbons were detected. 3. Although incubations were in steady state in respect of oxygen consumption, 14CO2 production and generation of acid-soluble radioactivity, quantitative analysis of acyl-CoA esters showed that steady state was not achieved in respect of all intermediates. 4. 3-Hydroxyacyl- and 2-enoyl-CoA and -carnitine esters were found under normoxic conditions. 5. Direct measurement of NAD+ and NADH shows that under identical incubation conditions our observations cannot be explained by gross perturbation of the [NAD+]/[NADH] ratio. 6. We hypothesize that there is a small pool of rapidly recycling NAD+ channelled between complex I of the respiratory chain and the newly described mitochondrial-inner-membrane-associated beta-oxidation trifunctional enzyme [Uchida, Izai, Orii and Hashimoto (1992) J. Biol. Chem. 267, 1034-1041].
Collapse
Affiliation(s)
- S Eaton
- Departments of Child Health, Medical School, University of Newcastle upon Tyne, U.K
| | | | | | | | | |
Collapse
|
37
|
Kler RS, Sherratt HS, Turnbull DM. The measurement of mitochondrial beta-oxidation by release of 3H2O from [9,10-3H]hexadecanoate: application to skeletal muscle and the use of inhibitors as models of metabolic disease. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1992; 47:145-56. [PMID: 1515172 DOI: 10.1016/0885-4505(92)90018-t] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We describe the use of a simple assay for beta-oxidation which depends on the release of 3H2O from [9,10-3H]hexadecanoate. This was compared with the use of [1-14C]hexadecanoate which gave comparable results when all the products of beta-oxidation were measured. The prediction that 75% of the tritium is released as 3H2O and 25% as [2-3H]acetyl units was confirmed. The assay was used successfully to demonstrate impaired beta-oxidation in tissue preparations from rats treated with etomoxir and methylenecyclopropylpyruvate which are known inhibitors of beta-oxidation. Abnormalities of beta-oxidation were also detected in skeletal muscle from patients with defects of mitochondrial oxidation.
Collapse
Affiliation(s)
- R S Kler
- Division of Clinical Neuroscience Medical School, University of Newcastle upon Tyne, United Kingdom
| | | | | |
Collapse
|
38
|
Reubsaet FA, Veerkamp JH, Brückwilder ML, Trijbels JM, Hashimoto T, Monnens LA. Immunochemical and biochemical studies of fatty acid oxidation in fibroblasts of Zellweger and X-linked adrenoleukodystrophy patients. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1083:305-9. [PMID: 2049396 DOI: 10.1016/0005-2760(91)90087-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Immunoblot analyses of peroxisomal beta-oxidation enzymes showed that subunit A of acyl-CoA oxidase gave a stronger immunoreaction in fibroblasts of Zellweger and X-linked adrenoleukodystrophy patients than in those of controls. Subunits B and C and 3-ketoacyl-CoA thiolase were detected in fibroblasts of controls and X-linked adrenoleukodystrophy patients, but not of Zellweger patients. Total oxidation of palmitic and lignoceric acid was normal in homogenates of fibroblasts from Zellweger and X-linked adrenoleukodystrophy patients. The peroxisomal oxidation of both acids was only deficient in Zellweger patients. These data may not reflect the situation in vivo, as is evident from the accumulation of very-long-chain fatty acids in Zellweger and X-linked adrenoleukodystrophy patients.
Collapse
Affiliation(s)
- F A Reubsaet
- Department of Pediatrics, University of Nijmegen, The Netherlands
| | | | | | | | | | | |
Collapse
|
39
|
Glatz JF, van der Vusse GJ. Cellular fatty acid-binding proteins: current concepts and future directions. Mol Cell Biochem 1990; 98:237-51. [PMID: 2266965 DOI: 10.1007/bf00231390] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
At least three different proteins are implicated in the cellular transport of fatty acid moieties: a plasmalemmal membrane and a cytoplasmic fatty acid-binding protein (FABPPM and FABPC, respectively) and cytoplasmic acyl-CoA binding protein (ACBP). Their putative main physiological significance is the assurance that long-chain fatty acids and derivatives, either in transit through membranes or present in intracellular compartments, are largely complexed to proteins. FABPC distinguishes from the other proteins in that distinct types of FABPC are found in remarkable abundance in the cytoplasmic compartment of a variety of tissues. Although their mechanism of action is not yet fully elucidated, current knowledge suggests that the function of this set of proteins reaches beyond simply aiding cytoplasmic solubilization of hydrophobic ligands, but that they can be assigned several regulatory roles in cellular lipid homeostasis.
Collapse
Affiliation(s)
- J F Glatz
- Department of Physiology, University of Limburg, Maastricht, The Netherlands
| | | |
Collapse
|
40
|
Reubsaet FA, Veerkamp JH, Trijbels JM, Monnens LA. Total and peroxisomal oxidation of various saturated and unsaturated fatty acids in rat liver, heart and m. quadriceps. Lipids 1989; 24:945-50. [PMID: 2615563 DOI: 10.1007/bf02544539] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Rates of total and peroxisomal fatty acid oxidation were estimated from the production of 14C-labeled CO2 and acid-soluble products from differently labeled [14C]fatty acids, in the absence and presence of antimycinrotenone, in homogenates of liver, heart and m. quadriceps. Total and peroxisomal oxidation rates of palmitic, oleic and linoleic acid were 3-4 times higher than those of arachidonic and adrenic acid which had higher oxidation rates than those of lignoceric and erucic acid. The peroxisomal contribution to the oxidation of the last fatty acids was similar to or higher than that of palmitic acid. For all fatty acids tested in these tissues, the mitochondrial contribution to beta-oxidation was higher than the peroxisomal contribution. Production of 14CO2 and 14C-labeled, acid-soluble metabolites from [13-14]arachidonic acid indicated that polyunsaturated fatty acids can be chain-shortened beyond their double bonds in m. quadriceps and heart as well as in liver. Although 2,4-dienoyl-CoA reductase requires NADPH, addition of this coenzyme did not influence arachidonic acid oxidation. Arachidonic acid oxidation was inhibited by palmitic acid in mitochondria and peroxisomes, but arachidonic acid had only a slight effect on palmitic acid oxidation.
Collapse
Affiliation(s)
- F A Reubsaet
- Department of Pediatrics, University of Nijmegen, The Netherlands
| | | | | | | |
Collapse
|
41
|
Abstract
Developmental profiles were determined for the activities of eight enzymes involved in fatty acid beta-oxidation in rat brain. The enzymes studied were the palmitoyl-CoA, octanoyl-CoA, butyryl-CoA, glutaryl-CoA, and 3-hydroxyacyl-CoA dehydrogenases, the enoyl-CoA hydratase (crotonase), and the C4- and C10-thiolases. With the exception of the thiolases, all of the activities (expressed on the basis of brain weight) increased during the postnatal period of brain maturation. The activity of octanoyl-CoA dehydrogenase was elevated markedly compared to that of palmitoyl-CoA dehydrogenase at all developmental stages and in all brain regions in the rat. A similar relationship between these enzymes was observed in various regions of adult human brain. Comparisons of the activities of the beta-oxidation enzymes in human brain versus human skeletal muscle and in cultured neural cell lines (neuroblastoma and glioma) versus cultured skin fibroblasts revealed that the elevated activity of octanoyl-CoA dehydrogenase relative to palmitoyl-CoA dehydrogenase was specific to the neural tissues. This relationship was particularly evident when the enzyme activities were normalized to the activity of crotonase. The data support previous findings with radiochemical tracers, indicating that the brain is capable of utilizing fatty acids as substrates for oxidative energy metabolism. The relatively high activity of the medium-chain fatty acyl-CoA dehydrogenase in neural tissue may represent an adaptive mechanism to protect the brain from the known encephalopathic effects of octanoate and other medium-chain fatty acids that readily cross the blood-brain barrier.
Collapse
Affiliation(s)
- H Reichmann
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York
| | | | | |
Collapse
|
42
|
Turnbull DM, Sherratt HS. Metabolic studies using isolated skeletal muscle: investigation of metabolic myopathies. BAILLIERE'S CLINICAL ENDOCRINOLOGY AND METABOLISM 1987; 1:967-97. [PMID: 3330437 DOI: 10.1016/s0950-351x(87)80013-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
43
|
Fatty acid oxidation in rat brain is limited by the low activity of 3-ketoacyl-coenzyme A thiolase. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)45161-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
44
|
Chatzidakis C, Otto DA. Labeled oxidation products from [1-14C], [U-14C] and [16-14C]-palmitate in hepatocytes and mitochondria. Lipids 1987; 22:620-6. [PMID: 3312905 DOI: 10.1007/bf02533939] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
When [1-14C], [U-14C], and [16-14C]palmitate were oxidized by isolated rat hepatocytes, there was a differential distribution of label as a percent of total oxidized products, such that 14CO2 from [1-14C] greater than [U-14C] greater than [16-14C]palmitate and acid-soluble radioactivity from [16-14C] greater than [U-14C] greater than [1-14C]palmitate. The oxidation of [2,3-14C]succinate to 14CO2 by isolated hepatocytes was only 9.1% of that from [1,4-14C]succinate, demonstrating that the differences in distribution of labeled products are in part due to less 14CO2 production from label in the even carbon positions entering the citric acid cycle. Apparent total ketone body production from [16-14C]palmitate was markedly higher than [1-14C] and [U-14C]palmitate. In addition, the 14C-acetone:14CO2 ratio derived from decarboxylation of labeled acetoacetate from [1-14C]palmitate was less than 1 and positively correlated to the rate of fatty acid oxidation in hepatocytes. These findings indicate that the known preferential incorporation of the omega-C2 unit of fatty acids into 14C-ketone bodies also contributed to the differential distribution of labeled products and that this contribution was greatest at the lower rates of fatty acid oxidation. In isolated mitochondria, the distribution of label to 14CO2 and acid-soluble radioactivity from [1-14C], [U-14C] and [16-14C]palmitate was qualitatively similar to that seen with hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- C Chatzidakis
- Graduate Program in Nutrition, Rutgers, State University of New Jersey, New Brunswick
| | | |
Collapse
|
45
|
Wanders RJ, Barth PG, van Roermund CW, Ofman R, Wolterman R, Schutgens RB, Tager JM, van den Bosch H, Bolhuis PA. Peroxisomes and peroxisomal functions in muscle. Studies with muscle cells from controls and a patient with the cerebro-hepato-renal (Zellweger) syndrome. Exp Cell Res 1987; 170:147-52. [PMID: 3569428 DOI: 10.1016/0014-4827(87)90123-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In the present study we investigated peroxisomal functions in cultured human muscle cells from control subjects and from a patient with the Zellweger syndrome, a genetic disease characterized by the absence of morphologically distinguishable peroxisomes in liver and kidney. In homogenates of cultured muscle cells from control subjects, catalase is contained within subcellular particles, acyl-CoA:dihydroxyacetonephosphate acyltransferase activity is present and palmitoyl-CoA can be oxidized by a peroxisomal beta-oxidative pathway; these findings are indicative of the presence of peroxisomes in the cells. In homogenates of cultured muscle cells from the patient with the Zellweger syndrome, acyl-CoA:dihydroxyacetonephosphate acyltransferase activity was deficient, peroxisomal beta-oxidation of palmitoyl-CoA was impaired and catalase was not particle-bound. These findings indicate that functional peroxisomes are absent in muscle from patients with the Zellweger syndrome. We conclude that cultured human muscle cells can be used as a model system to study peroxisomal functions in muscle and the consequences for this tissue of a generalized dysfunction of peroxisomes.
Collapse
|
46
|
Veerkamp JH, Zevenbergen JL. Effect of dietary fat on total and peroxisomal fatty acid oxidation in rat tissues. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 878:102-9. [PMID: 3730409 DOI: 10.1016/0005-2760(86)90348-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In this study the effect of dietary trans fatty acids on the peroxisomal and mitochondrial beta-oxidation is compared with that of saturated or cis-monounsaturated fatty acids. Oxidation of [1-14C]- and [16-14C]palmitate was assayed in the absence as well as in the presence of antimycin plus rotenone in homogenates of liver, heart and skeletal muscle of four groups of rats fed diets containing 40 energy% fat of different fatty acid composition. Three groups were given fat blends rich in C16, C18 saturated (cocoa butter), cis-monounsaturated (low-linoleic-acid olive oil) or trans fatty acids (partially hydrogenated soybean oil), respectively. The fourth group received a mixture of these fats with half the amount of trans fatty acids of the third group. Total oxidation rates of [1-14C]- and [16-14C]palmitate in the absence of antimycin were not significantly influenced by the type of dietary fat in the investigated tissues. The antimycin-insensitive [1-14C]palmitate oxidation rate and the proportion of peroxisomal oxidation of the total oxidation were lower in all tissues of those animals fed the mixed dietary fat than in those fed the other diets; both parameters were higher in the liver of cocoa butter-fed rats than in those of the other groups. Comparison of the results with literature data and with previous results obtained with a low-fat diet (Veerkamp and Van Moerkerk (1986) Biochim. Biophys. Acta 875, 301-310) indicates that high-fat diets only induce peroxisomal beta-oxidation activity if they also contain C20, C22 fatty acids. High dietary concentrations of trans C18 fatty acids do not result in a higher peroxisomal activity than that observed for other fatty acids with the same chain length.
Collapse
|
47
|
Veerkamp JH, van Moerkerk TB, Glatz JF, Zuurveld JG, Jacobs AE, Wagenmakers AJ. 14CO2 production is no adequate measure of [14C]fatty acid oxidation. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1986; 35:248-59. [PMID: 3087394 DOI: 10.1016/0885-4505(86)90080-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Palmitate oxidation was comparatively assayed in various cell-free and cellular systems by 14CO2 production and by the sum of 14CO2 and 14C-labeled acid-soluble products. The 14CO2 production rate was dependent on incubation time and amount of tissue in contrast to the total oxidation rate. The 14CO2 contribution to the oxidation rate of [1-14C]palmitate varied with homogenates from 1% with rat liver to 28% with rat kidney and amounted to only 2-4% with human muscles. With cellular systems the 14CO2 contribution varied between 20% in human fibroblasts and 70% in rat muscles and myocytes. Addition of cofactors increased the oxidation rate, but decreased the 14CO2 contribution. Various conditions appeared also to influence to a different extent the 14CO2 production and the total oxidation rate with rat tissue homogenates and with rat muscle mitochondria. Incorporation of radioactivity from [1-14C]palmitate into protein was not detectable in cell-free systems and only 2-3% of the sum of 14CO2 and 14C-labeled acid-soluble products in cellular systems. Assay of 14CO2 and 14C-labeled acid-soluble products is a much more accurate and sensitive estimation of fatty acid oxidation than assay of only 14CO2.
Collapse
|
48
|
Veerkamp JH, van Moerkerk HT, Bakkeren JA. An accurate and sensitive assay of [14C]octanoate oxidation and its application on tissue homogenates and fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 876:133-7. [PMID: 3081042 DOI: 10.1016/0005-2760(86)90326-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A procedure was developed to assay [14C]octanoate oxidation from the production of both 14CO2 and 14C-labeled acid-soluble products. Octanoic acid and its CoA and carnitine esters were eliminated from the acid-soluble products by alkaline hydrolysis of the esters and acidification and binding of the acid to Lipidex 1000. The method was evaluated with homogenates of various rat tissues and human muscles and with human fibroblasts. 14CO2 production was variable and comprised less than 3% of the total oxidation products with homogenates and 26 +/- 19% with fibroblasts. As compared to palmitate, oxidation rates of octanoate were higher in rat liver and heart homogenates, of the same magnitude in muscle homogenates, but lower in fibroblasts. The proportion of antimycin-insensitive oxidation was much lower with octanoate than with palmitate. Using the assay a case of medium-chain acyl-CoA dehydrogenase deficiency could be indicated.
Collapse
|
49
|
Lanser AC, Emken EA, Ohlrogge JB. Oxidation of oleic and elaidic acids in rat and human heart homogenates. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 875:510-5. [PMID: 3947656 DOI: 10.1016/0005-2760(86)90071-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Parallel incubations with uniformly 14C-labeled oleic and elaidic acids were conducted to compare oxidation rates in tissue homogenates prepared from rat and human hearts. Radioactivity in 14CO2 and 14C-labeled chain-shortened acid-soluble products was used to measure the extent of oxidation. Oxidation rates (pmol/min per mg heart protein) determined on 14C-labeled acid-soluble products suggest that oleic acid was oxidized 35-40% faster than elaidic acid by both male and female rat heart homogenates, whereas human heart homogenates oxidized these fatty acids at equal rates. Rates for female heart homogenates were somewhat higher than those for males in rats and humans. Rates of formation of 14CO2 were the same for each acid in rat and human heart tissue. Comparative rates of formation of oxidation products expressed as oleic/elaidic ratios from parallel incubations confirm that preferential oxidation of oleic acid occurred with rat heart homogenates, but not with the human heart homogenates. These data suggest that the presence of the trans double bond in elaidic acid does not impair its utilization for energy by human heart muscle.
Collapse
|
50
|
MacDonald RS, Swan PB. The effect of three hypolipidemic drugs on catalase activity and peroxisomal and mitochondrial palmitate oxidation in rat cardiac and skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 880:153-60. [PMID: 3942787 DOI: 10.1016/0304-4165(86)90075-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Catalase activity and peroxisomal and mitochondrial palmitate oxidation have been investigated in cardiac and skeletal muscle from rats fed clofibrate, ciprofibrate or nafenopin in an unrefined diet for different periods of time. Nafenopin was also added to either a high carbohydrate (70% of kilocalories from glucose) or high fat (70% of kilocalories from lard) diet and fed to rats for either 1 or 3 weeks. Catalase activity was elevated in all muscles from rats fed the hypolipidemic drugs. The response of catalase activity in muscle to clofibrate was dose-dependent. The response time of catalase activity was different in individual muscles. Peroxisomal palmitate oxidation was elevated in the heart and soleus muscle from rats fed nafenopin in either the high-carbohydrate or the high-fat diet. There was no change in peroxisomal palmitate oxidation in psoas or extensor digitorum longus muscle from rats fed the drugs. Mitochondrial palmitate oxidation was only slightly increased by nafenopin in the heart and soleus muscles after 3 weeks of nafenopin feeding. The results suggest that the cardiac muscle, like the liver, responds to hypolipidemic drug treatment with an increase in peroxisomal fat oxidation. The skeletal muscle response is less specific and that tissue may not contribute to the hypolipidemic effect of the drugs. The findings also suggest that these drugs do not induce peroxisome proliferation in skeletal muscle.
Collapse
|