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Babcock SJ, Houten SM, Gillingham MB. A review of fatty acid oxidation disorder mouse models. Mol Genet Metab 2024; 142:108351. [PMID: 38430613 PMCID: PMC11073919 DOI: 10.1016/j.ymgme.2024.108351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/05/2024]
Abstract
Fatty acid oxidation disorders (FAODs) are a family of rare, genetic disorders that affect any part of the fatty acid oxidation pathway. Patients present with severe phenotypes, such as hypoketotic hypoglycemia, cardiomyopathy, and rhabdomyolysis, and currently manage these symptoms by the avoidance of fasting and maintaining a low-fat, high-carbohydrate diet. Because knowledge about FAODs is limited due to the small number of patients, rodent models have been crucial in learning more about these disorders, particularly in studying the molecular mechanisms involved in different phenotypes and in evaluating treatments for patients. The purpose of this review is to present the different FAOD mouse models and highlight the benefits and limitations of using these models. Specifically, we discuss the phenotypes of the available FAOD mouse models, the potential molecular causes of prominent FAOD phenotypes that have been studied using FAOD mouse models, and how FAOD mouse models have been used to evaluate treatments for patients.
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Affiliation(s)
- Shannon J Babcock
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA.
| | - Sander M Houten
- Deparment of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Melanie B Gillingham
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
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Karunanidhi A, Van’t Land C, Rajasundaram D, Grings M, Vockley J, Mohsen AW. Medium branched chain fatty acids improve the profile of tricarboxylic acid cycle intermediates in mitochondrial fatty acid β-oxidation deficient cells: A comparative study. J Inherit Metab Dis 2022; 45:541-556. [PMID: 35076099 PMCID: PMC9090965 DOI: 10.1002/jimd.12480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/09/2022] [Accepted: 01/24/2022] [Indexed: 12/06/2022]
Abstract
Inherited errors of mitochondrial fatty acid β-oxidation (FAO) are life threatening, even with optimum care. FAO is the major source of energy for heart and is critical for skeletal muscles especially during physiologic stress. Clinical trials revealed that triheptanoin (commercially known as Dojolvi; C7G), improved heart function and decreased hypoglycemia in long chain FAO disorders, but other symptoms including rhabdomyolysis persisted, suggesting suboptimal tissue distribution/utilization of heptanoic acid (C7) conjugates and/or rapid liver breakdown. In this study, medium branched chain fatty acids were tested as potential anaplerotic treatments in fibroblasts from patients deficient in very long chain acyl-CoA dehydrogenase (VLCAD), long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), trifunctional protein (TFP), and carnitine palmitoyltransferase II (CPT II). Cells were cultured to near confluency and treated with C7, 2,6-dimethylheptanoic acid (dMC7), 6-amino-2,4-dimethylheptanoic acid (AdMC7), or 4,8-dimethylnonanoic acid (dMC9) for 72 h and targeted metabolomics performed. The profile of TCA cycle intermediates was improved in cells treated with these branched chain fatty acids compared with C7. Intracellular propionate was higher in AdMC7 treated cells compared with C7 in VLCAD, LCHAD, and TFP deficient cell lines. With AdMC7 treatment, succinate was higher in CPT II and VLCAD deficient cells, compared with C7. Malate and glutamate were consistently higher in AdMC7 treated VLCAD, LCHAD, TFP, and CPT II deficient cells compared with the C7 treatment. The results provide the impetus to further evaluate and consider branched chain fatty acids as viable anaplerotic therapy for fatty acid oxidation disorders and other diseases.
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Affiliation(s)
- Anuradha Karunanidhi
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Clinton Van’t Land
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dhivyaa Rajasundaram
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mateus Grings
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- PPG Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Jerry Vockley
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Al-Walid Mohsen
- Department of Pediatrics, School of Medicine, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Gaston G, Gangoiti JA, Winn S, Chan B, Barshop BA, Harding CO, Gillingham MB. Cardiac tissue citric acid cycle intermediates in exercised very long-chain acyl-CoA dehydrogenase-deficient mice fed triheptanoin or medium-chain triglyceride. J Inherit Metab Dis 2020; 43:1232-1242. [PMID: 33448436 DOI: 10.1002/jimd.12284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/01/2020] [Accepted: 07/07/2020] [Indexed: 11/11/2022]
Abstract
Anaplerotic odd-chain fatty acid supplementation has been suggested as an approach to replenish citric acid cycle intermediate (CACi) pools and facilitate adenosine triphosphate (ATP) production in subjects with long-chain fatty acid oxidation disorders, but the evidence that cellular CACi depletion exists and that repletion occurs following anaplerotic substrate supplementation is limited. We exercised very long-chain acyl-CoA dehydrogenase-deficient (VLCAD-/-) and wild-type (WT) mice to exhaustion and collected cardiac tissue for measurement of CACi by targeted metabolomics. In a second experimental group, VLCAD-/- and WT mice that had been fed chow prepared with either medium-chain triglyceride (MCT) oil or triheptanoin for 4 weeks were exercised for 60 minutes. VLCAD-/- mice exhibited lower succinate in cardiac muscle at exhaustion than WT mice suggesting lower CACi in VLCAD-/- with prolonged exercise. In mice fed either MCT or triheptanoin, succinate and malate were greater in VLCAD-/- mice fed triheptanoin compared to VLCAD-/- animals fed MCT but lower than WT mice fed triheptanoin. Long-chain odd acylcarnitines such as C19 were elevated in VLCAD-/- and WT mice fed triheptanoin suggesting some elongation of the heptanoate, but it is unknown what proportion of heptanoate was oxidized vs elongated. Prolonged exercise was associated with decreased cardiac muscle succinate in VLCAD-/- mice in comparison to WT mice. VLCAD-/- fed triheptanoin had increased succinate compared to VLCAD-/- mice fed MCT but lower than WT mice fed triheptanoin. Cardiac CACi were higher following dietary ingestion of an anaplerotic substrate, triheptanoin, in comparison to MCT.
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Affiliation(s)
- Garen Gaston
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Jon A Gangoiti
- Department of Pediatrics, Genetics Division, Biochemical Genetics Program, University of California San Diego, La Jolla, California, USA
| | - Shelley Winn
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Benjamin Chan
- Biostatistics and Design Program, School of Public Health, Oregon Health & Science University, Portland, Oregon, USA
| | - Bruce A Barshop
- Department of Pediatrics, Genetics Division, Biochemical Genetics Program, University of California San Diego, La Jolla, California, USA
| | - Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Melanie B Gillingham
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
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Baldini F, Portincasa P, Grasselli E, Damonte G, Salis A, Bonomo M, Florio M, Serale N, Voci A, Gena P, Vergani L, Calamita G. Aquaporin-9 is involved in the lipid-lowering activity of the nutraceutical silybin on hepatocytes through modulation of autophagy and lipid droplets composition. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158586. [PMID: 31816412 DOI: 10.1016/j.bbalip.2019.158586] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/26/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023]
Abstract
Hepatic steatosis is the hallmark of non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome and insulin resistance with potential evolution towards non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Key roles of autophagy and oxidative stress in hepatic lipid accumulation and NAFLD progression are recognized. Here, we employed a rat hepatoma cell model of NAFLD progression made of FaO cells exposed to oleate/palmitate followed or not by TNFα treatment to investigate the molecular mechanisms through which silybin, a lipid-lowering nutraceutical, may improve hepatic lipid dyshomeostasis. The beneficial effect of silybin was found to involve amelioration of the fatty acids profile of lipid droplets, stimulation of the mitochondrial oxidation and upregulation of a microRNA of pivotal relevance in hepatic fat metabolism, miR-122. Silybin was also found to restore the levels of Aquaporin-9 (AQP9) and glycerol permeability while reducing the activation of the oxidative stress-dependent transcription factor NF-κB, and autophagy turnover. In conclusion, silybin was shown to have molecular effects on signaling pathways that were previously unknown and potentially protect the hepatocyte. These actions intersect TG metabolism, fat-induced autophagy and AQP9-mediated glycerol transport in hepatocytes.
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Affiliation(s)
| | - Piero Portincasa
- Clinica Medica "A. Murri", Dept. of Biomedical Sciences and Human Oncology, Medical School, University of Bari "Aldo Moro", Italy
| | - Elena Grasselli
- DISTAV, Dept. of Earth, Environment and Life Sciences, Italy
| | | | - Annalisa Salis
- DISTAV, Dept. of Earth, Environment and Life Sciences, Italy
| | - Michela Bonomo
- Dept. of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Italy
| | - Marilina Florio
- Dept. of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Italy
| | - Nadia Serale
- DISTAV, Dept. of Earth, Environment and Life Sciences, Italy
| | - Adriana Voci
- DISTAV, Dept. of Earth, Environment and Life Sciences, Italy
| | - Patrizia Gena
- Dept. of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Italy
| | - Laura Vergani
- DISTAV, Dept. of Earth, Environment and Life Sciences, Italy.
| | - Giuseppe Calamita
- Dept. of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Italy.
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Wang W, Palmfeldt J, Mohsen AW, Gregersen N, Vockley J. Fasting induces prominent proteomic changes in liver in very long chain Acyl-CoA dehydrogenase deficient mice. Biochem Biophys Rep 2016; 8:333-339. [PMID: 28955973 PMCID: PMC5613767 DOI: 10.1016/j.bbrep.2016.08.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/27/2016] [Accepted: 08/09/2016] [Indexed: 12/26/2022] Open
Abstract
Very long chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD) is a clinically heterogeneous disorder of mitochondrial fatty acid β-oxidation usually identified through newborn screening. Genotype-phenotype correlations have been defined, but considerable clinical heterogeneity still exists. Symptoms are often induced by physiological stress such as fasting or intercurrent illness, setting it as an important example of environmental effects altering clinical course in an individual with a genetic disease. However, neither the cellular changes that predispose to this phenomenon nor the alterations it induces are well characterized. We examined the effects of fasting in a knockout mouse model to explore changes in global mitochondria protein profiles in liver and to investigate the physiologically relevant changes that lead to the clinical presentations. An isobaric tags for relative and absolute quantification (iTRAQ) labeling approach was employed to examine mitochondrial proteome changes in VLCAD deficient compared to wild type mice in the fed and fasted states. We identified numerous proteomic changes associated with the gene defect and fasting within relevant metabolic pathways. Few changes induced by fasting were shared between the VLCAD deficient and wild type mice, with more alterations found in the deficient mice on fasting. Particularly, fasting in the deficient mice could reverse the protective response in oxidative phosphorylation pathway seen in wild type animals. In addition, we found that changes in chaperone proteins including heat shock protein 60 (HSP60) and 10 (HSP10) during fasting differed between the two genotypes, highlighting the importance of these proteins in VLCAD deficiency. Finally, the effects on the liver proteome imposed by changes in fasted VLCAD deficient mice indicates that this environmental factor may be an inducer of both cellular and physiological changes. VLCAD deficient mice show significant changes in the proteome compared to wild type animals. Hypoglycemia induces different proteomic changes in VLCAD deficient mice than is seen in wild type animals. Multiple functional pathways are altered in VLCAD deficient animals. Proteomic changes in VLCAD deficient mice may help understand the physiologic ramifications of this deficiency in humans.
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Affiliation(s)
- Wei Wang
- Department of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, China.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, USA
| | - Johan Palmfeldt
- Research Unit for Molecular Medicine, Institute of Clinical Medicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Al-Walid Mohsen
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Niels Gregersen
- Research Unit for Molecular Medicine, Institute of Clinical Medicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Jerry Vockley
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, USA.,Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, USA
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Tucci S, Pearson S, Herebian D, Spiekerkoetter U. Long-term dietary effects on substrate selection and muscle fiber type in very-long-chain acyl-CoA dehydrogenase deficient (VLCAD(-/-)) mice. Biochim Biophys Acta Mol Basis Dis 2013; 1832:509-16. [PMID: 23313579 DOI: 10.1016/j.bbadis.2013.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 12/28/2012] [Accepted: 01/04/2013] [Indexed: 12/11/2022]
Abstract
Dietary fat restriction and increased carbohydrate intake are part of treatment in very-long-chain acyl-CoA dehydrogenase (VLCAD)-deficiency, the most common defect of long-chain fatty acid oxidation. The long-term impact of these interventions is unknown. We characterized here the effects of a fat-reduced, carbohydrate-enriched diet and an increased fat intake on energy metabolism in a mouse model of VLCAD-deficiency. Wild-type and VLCAD(-/-) mice were fed one year either with a normal (5.1%), a high fat (10.6%) or a low-fat, carbohydrate-enriched (2.6%) diet. Dietary effects on genes involved in lipogenesis, energy homeostasis and substrate selection were quantified by real-time-PCR. Acylcarnitines as sign of impaired energy production were determined in dried blood spots and tissues. White skeletal muscle was analyzed for muscle fiber type as well as for glycogen and triglyceride content. Both dietary modifications induced enhanced triacylglyceride accumulation in skeletal muscle and inhibition of glucose oxidation. This was accompanied by an up-regulation of genes coding for oxidative muscle fiber type I and a marked accumulation of acylcarnitines, especially prominent in the heart (164±2.8 in VLCAD(-/-) vs. 82.3±2.1 in WT μmol/mg) under a low-fat, carbohydrate-enriched diet. We demonstrate here that both dietary interventions with respect to the fat content of the diet reverse endogenous compensatory mechanisms in muscle that have evolved in VLCAD(-/-) mice resulting in pronounced energy deficiency. In particular, the low-fat carbohydrate-enriched diet was not effective in the long term. Further experiments are necessary to define the optimal energy provision for fatty acid oxidation defects.
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Affiliation(s)
- Sara Tucci
- Department of General Pediatrics, University Hospital Freiburg, Germany.
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Long-term correction of very long-chain acyl-coA dehydrogenase deficiency in mice using AAV9 gene therapy. Mol Ther 2012; 20:1131-8. [PMID: 22395529 PMCID: PMC3370259 DOI: 10.1038/mt.2012.39] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Very long-chain acyl-coA dehydrogenase (VLCAD) is the rate-limiting step in mitochondrial fatty acid oxidation. VLCAD-deficient mice and patients clinical symptoms stem from not only an energy deficiency but also long-chain metabolite accumulations. VLCAD-deficient mice were treated systemically with 1 × 1012 vector genomes of recombinant adeno-associated virus 9 (rAAV9)-VLCAD. Biochemical correction was observed in vector-treated mice beginning 2 weeks postinjection, as characterized by a significant drop in long-chain fatty acyl accumulates in whole blood after an overnight fast. Changes persisted through the termination point around 20 weeks postinjection. Magnetic resonance spectroscopy (MRS) and tandem mass spectrometry (MS/MS) revealed normalization of intramuscular lipids in treated animals. Correction was not observed in liver tissue extracts, but cardiac muscle extracts showed significant reduction of long-chain metabolites. Disease-specific phenotypes were characterized, including thermoregulation and maintenance of euglycemia after a fasting cold challenge. Internal body temperatures of untreated VLCAD−/− mice dropped below 20 °C and the mice became lethargic, requiring euthanasia. In contrast, all rAAV9-treated VLCAD−/− mice and the wild-type controls maintained body temperatures. rAAV9-treated VLCAD−/− mice maintained euglycemia, whereas untreated VLCAD−/− mice suffered hypoglycemia following a fasting cold challenge. These promising results suggest rAAV9 gene therapy as a potential treatment for VLCAD deficiency in humans.
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