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Uc A, Strandvik B, Yao J, Liu X, Yi Y, Sun X, Welti R, Engelhardt J, Norris A. The fatty acid imbalance of cystic fibrosis exists at birth independent of feeding in pig and ferret models. Clin Sci (Lond) 2022; 136:1773-1791. [PMID: 36416119 PMCID: PMC9747517 DOI: 10.1042/cs20220450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022]
Abstract
Persons with cystic fibrosis (CF) exhibit a unique alteration of fatty acid composition, marked especially among polyunsaturates by relative deficiency of linoleic acid and excess of Mead acid. Relative deficiency of docosahexaenoic acid is variably found. However, the initial development of these abnormalities is not understood. We examined fatty acid composition in young CF ferrets and pigs, finding abnormalities from the day of birth onward including relative deficiency of linoleic acid in both species. Fatty acid composition abnormalities were present in both liver and serum phospholipids of newborn CF piglets even prior to feeding, including reduced linoleic acid and increased Mead acid. Serum fatty acid composition evolved over the first weeks of life in both non-CF and CF ferrets, though differences between CF and non-CF persisted. Although red blood cell phospholipid fatty acid composition was normal in newborn animals, it became perturbed in juvenile CF ferrets including relative deficiencies of linoleic and docosahexaenoic acids and excess of Mead acid. In summary, fatty acid composition abnormalities in CF pigs and ferrets exist from a young age including at birth independent of feeding and overlap extensively with the abnormalities found in humans with CF. That the abnormalities exist prior to feeding implies that dietary measures alone will not address the mechanisms of imbalance.
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Affiliation(s)
- Aliye Uc
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, U.S.A
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Birgitta Strandvik
- Department of Biosciences and Nutrition, Karolinska Institutet NEO, Flemingsberg, Stockholm 14183, Sweden
| | - Jianrong Yao
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Xiaoming Liu
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Yaling Yi
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Xingshen Sun
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Ruth Welti
- Kansas Lipidomics Research Center, Kansas State University, Manhattan, KS 66506, U.S.A
| | - John F. Engelhardt
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, U.S.A
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Andrew W. Norris
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, U.S.A
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, U.S.A
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2
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Shrestha N, McCarron A, Rout-Pitt N, Donnelley M, Parsons DW, Hryciw DH. Essential Fatty Acid Deficiency in Cystic Fibrosis Disease Progression: Role of Genotype and Sex. Nutrients 2022; 14:nu14214666. [PMID: 36364928 PMCID: PMC9657825 DOI: 10.3390/nu14214666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/01/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Adequate intake of nutrients such as essential fatty acids (EFA) are critical in cystic fibrosis (CF). The clinical course of deterioration of lung function in people with CF has been shown to relate to nutrition. Independent of the higher energy consumption and malabsorption due to pancreatic insufficiency, EFA deficiency is closely associated with the risk of pulmonary infection, the most significant pathology in CF. This review will focus on the EFA deficiency identified in people with CF, as well as the limited progress made in deciphering the exact metabolic pathways that are dysfunctional in CF. Specifically, people with CF are deficient in linoleic acid, an omega 6 fatty acid, and the ratio of arachidonic acid (omega 6 metabolite) and docosahexaenoic acid (omega 3 metabolite) is increased. Analysis of the molecular pathways in bronchial cells has identified changes in the enzymes that metabolise EFA. However, fatty acid metabolism primarily occurs in the liver, with EFA metabolism in CF liver not yet investigated, indicating that further research is required. Despite limited understanding in this area, it is well known that adequate EFA concentrations are critical to normal membrane structure and function, and thus are important to consider in disease processes. Novel insights into the relationship between CF genotype and EFA phenotype will be discussed, in addition to sex differences in EFA concentrations in people with CF. Collectively, investigating the specific effects of genotype and sex on fatty acid metabolism may provide support for the management of people with CF via personalised genotype- and sex-specific nutritional therapies.
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Affiliation(s)
- Nirajan Shrestha
- School of Pharmacy and Medical Sciences, Griffith University, Southport, QLD 4222, Australia
| | - Alexandra McCarron
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia
- Robinson Research Institute, University of Adelaide, Adelaide, SA 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Nathan Rout-Pitt
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia
- Robinson Research Institute, University of Adelaide, Adelaide, SA 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Martin Donnelley
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia
- Robinson Research Institute, University of Adelaide, Adelaide, SA 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - David W. Parsons
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5001, Australia
- Robinson Research Institute, University of Adelaide, Adelaide, SA 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Deanne H. Hryciw
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3000, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
- Correspondence: ; Tel.: +61-7-3735-3601
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Nutrition in Cystic Fibrosis—Some Notes on the Fat Recommendations. Nutrients 2022; 14:nu14040853. [PMID: 35215502 PMCID: PMC8875685 DOI: 10.3390/nu14040853] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 12/15/2022] Open
Abstract
Nutrition is important in cystic fibrosis (CF) because the disease is associated with a higher energy consumption, special nutritional deficiencies, and malabsorption mainly related to pancreatic insufficiency. The clinical course with deterioration of lung function has been shown to relate to nutrition. Despite general recommendation of high energy intake, the clinical deterioration is difficult to restrain suggesting that special needs have not been identified and specified. It is well-known that the CF phenotype is associated with lipid abnormalities, especially in the essential or conditionally essential fatty acids. This review will concentrate on the qualitative aspects of fat metabolism, which has mainly been neglected in dietary fat recommendations focusing on fat quantity. For more than 60 years it has been known and confirmed that the patients have a deficiency of linoleic acid, an n-6 essential fatty acid of importance for membrane structure and function. The ratio between arachidonic acid and docosahexaenoic acid, conditionally essential fatty acids of the n-6 and n-3 series, respectively, is often increased. The recently discovered relations between the CFTR modulators and lipid metabolism raise new interests in this field and together with new technology provide possibilities to specify further specify personalized therapy.
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Estes-Doetsch H, Ganzer H, Roberts K, Brody RA. Risk factors and assessment considerations for essential fatty acid deficiency in nonparenterally fed patients using a case example. Nutr Clin Pract 2022; 37:843-851. [PMID: 34978102 DOI: 10.1002/ncp.10822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Essential fatty acid deficiency (EFAD) has most commonly been reported in parenterally fed individuals but may also present in patients receiving fat-restricted diets and in patients with fat-malabsorption disorders. This article reviews the physical and biochemical assessment for EFAD in clinical practice and disorders of fat malabsorption as potential risk factors for EFAD. A case report is included to describe the fatty acid profile of a patient with exocrine pancreatic insufficiency receiving low-dose pancreatic enzyme replacement therapy after a self-imposed fat-restricted diet. The current challenges with laboratory interpretation of essential fatty acid status are also discussed.
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Affiliation(s)
- Holly Estes-Doetsch
- Medical Dietetics Division, College of Medicine, The Ohio State University, Columbus, Ohio, USA.,Division of Gastroenterology, Hepatology, and Nutrition, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Heidi Ganzer
- Department of Clinical and Preventive Nutrition Sciences, School of Health Professions, Rutgers University, Newark, New Jersey, USA
| | - Kristen Roberts
- Medical Dietetics Division, College of Medicine, The Ohio State University, Columbus, Ohio, USA.,Division of Gastroenterology, Hepatology, and Nutrition, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Rebecca A Brody
- Department of Clinical and Preventive Nutrition Sciences, School of Health Professions, Rutgers University, Newark, New Jersey, USA
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Lozier BK, Kim RN, Zuromski LM, Kish-Trier E, De Biase I, Yuzyuk T. Effect of fasting status and other pre-analytical variables on quantitation of long-chain fatty acids in red blood cells. Prostaglandins Leukot Essent Fatty Acids 2020; 163:102211. [PMID: 33249349 DOI: 10.1016/j.plefa.2020.102211] [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: 08/21/2020] [Revised: 11/08/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Long-chain fatty acids (LCFAs), including omega-3 and omega-6 fatty acids, play essential roles in health maintenance and outcomes. Insufficient intake or the inability to absorb LCFAs from the diet can cause a number of health problems. Evaluation of fatty acid profiles in plasma, serum or red blood cells (RBCs) is routinely used to monitor patients at risk of developing deficiency. Quantitation of LCFAs in RBCs offers advantages over serum/plasma due to low intra-individual variability. Fatty acid composition in RBCs also reflects long-term dietary intake, providing additional information about the patient's nutritional status. However, the literature does not currently address the impact of pre-analytical factors (conditions of RBC collection, sample handling and short-term storage) on LCFA measurements. This study evaluated the effect of several anticoagulants, interferents, different storage conditions and fasting status on quantitation of the twenty-one most abundant LCFAs in RBCs by gas chromatography negative chemical ionization-mass spectrometry (GCNCI-MS). LCFA results were assessed quantitatively (nmol/mL) or as a percent of total. Most common tube types (containing citrate, sodium heparin or EDTA) were all appropriate for blood collection. Whole blood and lysed RBCs were stable at least 24 h at room temperature and up to 7 days refrigerated. Lysed RBCs were also stable for up to three freeze/thaw cycles. The presence of icterus or lipemia did not affect results. LCFAs concentrations in RBCs did not change ~4 h after high-fat intake when the lipid concentration in circulation reaches a peak, while plasma levels of most fatty acids increased up to 40% in response. In summary, RBCs are a reliable sample type for LCFA quantitation in the clinical laboratory. In contrast to plasma or serum, RBCs isolated from non-fasting, hemolyzed or lipemic whole blood specimens are all acceptable for testing. Therefore, RBCs might be a preferable sample type for evaluation of nutritional status of young pediatric patients and in patients with conditions associated with hemolytic anemia or hyperlipidemia.
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Affiliation(s)
- B K Lozier
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States
| | - R N Kim
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States
| | - L M Zuromski
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States
| | - E Kish-Trier
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States
| | - I De Biase
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States; Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - T Yuzyuk
- ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States.
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Vandebrouck C, Ferreira T. Glued in lipids: Lipointoxication in cystic fibrosis. EBioMedicine 2020; 61:103038. [PMID: 33038767 PMCID: PMC7648119 DOI: 10.1016/j.ebiom.2020.103038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/27/2020] [Accepted: 09/14/2020] [Indexed: 01/14/2023] Open
Abstract
Cystic Fibrosis (CF) is an autosomal recessive disease caused by mutations in the CF transmembrane regulator (CFTR) gene, which encodes a chloride channel located at the apical surface of epithelial cells. Unsaturated Fatty Acid (UFA) deficiency has been a persistent observation in tissues from patients with CF. However, the impacts of such deficiencies on the etiology of the disease have been the object of intense debates. The aim of the present review is first to highlight the general consensus on fatty acid dysregulations that emerges from, sometimes apparently contradictory, studies. In a second step, a unifying mechanism for the potential impacts of these fatty acid dysregulations in CF cells, based on alterations of membrane biophysical properties (known as lipointoxication), is proposed. Finally, the contribution of lipointoxication to the progression of the CF disease and how it could affect the efficacy of current treatments is also discussed.
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Affiliation(s)
- Clarisse Vandebrouck
- Laboratoire "Lipointoxication and Channelopathies (LiTch) - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France; Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM; EA 7349)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Thierry Ferreira
- Laboratoire "Lipointoxication and Channelopathies (LiTch) - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France.
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Hanssens L, Duchateau J, Namane SA, Malfroot A, Knoop C, Casimir G. Influence of lung transplantation on the essential fatty acid profile in cystic fibrosis. Prostaglandins Leukot Essent Fatty Acids 2020; 158:102060. [PMID: 32044180 DOI: 10.1016/j.plefa.2020.102060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/05/2019] [Accepted: 01/21/2020] [Indexed: 12/28/2022]
Abstract
Lung transplantation is assumed to normalize essential fatty acid (EFA) profile in the plasma, described as abnormal in patients with cystic fibrosis (CF). This study sought to evaluate the EFA profile in both the plasma and erythrocyte membrane according to lung status by comparing CF patients with or without a lung transplant. A total of 50 homozygous F508del patients (33 CF patients [CF group] and 17 CF patients with a lung transplant [TX CF group]) were included. In comparison with the CF group, in the plasma, the levels of total n-3, α-linolenic, eicosapentaenoic, and docosahexaenoic acids were higher and the n-6/n-3 ratio was lower in the TX CF group. Yet, these differences were not observed in the erythrocyte membrane. This study supports that lung transplantation improves the EFA profile in the plasma but not in the erythrocyte membrane by means of the different mechanisms suggested in this article.
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Affiliation(s)
- Laurence Hanssens
- Hôpital Universitaire des Enfants Reine Fabiola, Avenue J.J. Crocq, 15,1020 Brussels, Belgium.
| | - J Duchateau
- Hôpital Universitaire des Enfants Reine Fabiola - Institut de mucoviscidose de l'ULB -Université Libre de Bruxelles, Brussels, Belgium
| | - S A Namane
- Universitair Ziekenhuis Brussel (UZ Brussel) - Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - A Malfroot
- Hôpital Universitaire Erasme - Institut de mucoviscidose de l'ULB - Université Libre de Bruxelles, Brussels, Belgium
| | - C Knoop
- Laboratoire de pédiatrie de l'Hôpital Universitaire des Enfants Reine Fabiola - Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - G Casimir
- Hôpital Universitaire des Enfants Reine Fabiola, Avenue J.J. Crocq, 15,1020 Brussels, Belgium
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Hepatobiliary Involvement in Cystic Fibrosis. Respir Med 2020. [DOI: 10.1007/978-3-030-42382-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kadri L, Ferru-Clément R, Bacle A, Payet LA, Cantereau A, Hélye R, Becq F, Jayle C, Vandebrouck C, Ferreira T. Modulation of cellular membrane properties as a potential therapeutic strategy to counter lipointoxication in obstructive pulmonary diseases. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3069-3084. [PMID: 29960042 DOI: 10.1016/j.bbadis.2018.06.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 06/04/2018] [Accepted: 06/25/2018] [Indexed: 02/08/2023]
Abstract
Maintaining the equilibrium between saturated and unsaturated fatty acids within membrane phospholipids (PLs) is crucial to sustain the optimal membrane biophysical properties, compatible with selective organelle-based processes. Lipointoxication is a pathological condition under which saturated PLs tend to accumulate within the cell at the expense of unsaturated species, with major impacts on organelle function. Here, we show that human bronchial epithelial cells extracted from lungs of patients with Obstructive Pulmonary Diseases (OPDs), i. e. Cystic Fibrosis (CF) individuals and Smokers, display a characteristic lipointoxication signature, with excessive amounts of saturated PLs. Reconstitution of this signature in cellulo and in silico revealed that such an imbalance results in altered membrane properties and in a dramatic disorganization of the intracellular network of bronchial epithelial cells, in a process which can account for several OPD traits. Such features include Endoplasmic Reticulum-stress, constitutive IL8 secretion, bronchoconstriction and, ultimately, epithelial cell death by apoptosis. We also demonstrate that a recently-identified lipid-like molecule, which has been shown to behave as a "membrane-reshaper", counters all the lipointoxication hallmarks tested. Altogether, these insights highlight the modulation of membrane properties as a potential new strategy to heal and prevent highly detrimental symptoms associated with OPDs.
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Affiliation(s)
- Linette Kadri
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Romain Ferru-Clément
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Amélie Bacle
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Laurie-Anne Payet
- Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Anne Cantereau
- Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Reynald Hélye
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Frédéric Becq
- Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Christophe Jayle
- Service de Chirurgie Cardiothoracique, CHU Poitiers, Poitiers, France
| | - Clarisse Vandebrouck
- Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Thierry Ferreira
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France.
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Kessler L, Abély M. Atteinte pancréatique exocrine et endocrine dans la mucoviscidose. Arch Pediatr 2016; 23:12S21-12S32. [DOI: 10.1016/s0929-693x(17)30059-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Seegmiller AC. Abnormal unsaturated fatty acid metabolism in cystic fibrosis: biochemical mechanisms and clinical implications. Int J Mol Sci 2014; 15:16083-99. [PMID: 25216340 PMCID: PMC4200767 DOI: 10.3390/ijms150916083] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 02/06/2023] Open
Abstract
Cystic fibrosis is an inherited multi-organ disorder caused by mutations in the CFTR gene. Patients with this disease exhibit characteristic abnormalities in the levels of unsaturated fatty acids in blood and tissue. Recent studies have uncovered an underlying biochemical mechanism for some of these changes, namely increased expression and activity of fatty acid desaturases. Among other effects, this drives metabolism of linoeate to arachidonate. Increased desaturase expression appears to be linked to cystic fibrosis mutations via stimulation of the AMP-activated protein kinase in the absence of functional CFTR protein. There is evidence that these abnormalities may contribute to disease pathophysiology by increasing production of eicosanoids, such as prostaglandins and leukotrienes, of which arachidonate is a key substrate. Understanding these underlying mechanisms provides key insights that could potentially impact the diagnosis, clinical monitoring, nutrition, and therapy of patients suffering from this deadly disease.
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Affiliation(s)
- Adam C Seegmiller
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, 4918B TVC, 1301 Medical Center Dr., Nashville, TN 37027, USA.
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Umunakwe OC, Seegmiller AC. Abnormal n-6 fatty acid metabolism in cystic fibrosis is caused by activation of AMP-activated protein kinase. J Lipid Res 2014; 55:1489-97. [PMID: 24859760 DOI: 10.1194/jlr.m050369] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Indexed: 12/14/2022] Open
Abstract
Cystic fibrosis (CF) patients and model systems exhibit consistent abnormalities in PUFA metabolism, including increased metabolism of linoleate to arachidonate. Recent studies have connected these abnormalities to increased expression and activity of the Δ6- and Δ5-desaturase enzymes. However, the mechanism connecting these changes to the CF transmembrane conductance regulator (CFTR) mutations responsible for CF is unknown. This study tests the hypothesis that increased activity of AMP-activated protein kinase (AMPK), previously described in CF bronchial epithelial cells, causes these changes in fatty acid metabolism by driving desaturase expression. Using CF bronchial epithelial cell culture models, we confirm elevated activity of AMPK in CF cells and show that it is due to increased phosphorylation of AMPK by Ca(2+)/calmodulin-dependent protein kinase kinase β (CaMKKβ). We also show that inhibition of AMPK or CaMKKβ reduces desaturase expression and reverses the metabolic alterations seen in CF cells. These results signify a novel AMPK-dependent mechanism linking the genetic defect in CF to alterations in PUFA metabolism.
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Affiliation(s)
- Obi C Umunakwe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - Adam C Seegmiller
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN
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