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Cedillo L, Ahsan FM, Li S, Stuhr NL, Zhou Y, Zhang Y, Adedoja A, Murphy LM, Yerevanian A, Emans S, Dao K, Li Z, Peterson ND, Watrous J, Jain M, Das S, Pukkila-Worley R, Curran SP, Soukas AA. Ether lipid biosynthesis promotes lifespan extension and enables diverse pro-longevity paradigms in Caenorhabditis elegans. eLife 2023; 12:e82210. [PMID: 37606250 PMCID: PMC10444025 DOI: 10.7554/elife.82210] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 07/13/2023] [Indexed: 08/23/2023] Open
Abstract
Biguanides, including the world's most prescribed drug for type 2 diabetes, metformin, not only lower blood sugar, but also promote longevity in preclinical models. Epidemiologic studies in humans parallel these findings, indicating favorable effects of metformin on longevity and on reducing the incidence and morbidity associated with aging-related diseases. Despite this promise, the full spectrum of molecular effectors responsible for these health benefits remains elusive. Through unbiased screening in Caenorhabditis elegans, we uncovered a role for genes necessary for ether lipid biosynthesis in the favorable effects of biguanides. We demonstrate that biguanides prompt lifespan extension by stimulating ether lipid biogenesis. Loss of the ether lipid biosynthetic machinery also mitigates lifespan extension attributable to dietary restriction, target of rapamycin (TOR) inhibition, and mitochondrial electron transport chain inhibition. A possible mechanistic explanation for this finding is that ether lipids are required for activation of longevity-promoting, metabolic stress defenses downstream of the conserved transcription factor skn-1/Nrf. In alignment with these findings, overexpression of a single, key, ether lipid biosynthetic enzyme, fard-1/FAR1, is sufficient to promote lifespan extension. These findings illuminate the ether lipid biosynthetic machinery as a novel therapeutic target to promote healthy aging.
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Affiliation(s)
- Lucydalila Cedillo
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical SchoolBostonUnited States
| | - Fasih M Ahsan
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical SchoolBostonUnited States
| | - Sainan Li
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
| | - Nicole L Stuhr
- Leonard Davis School of Gerontology, University of Southern CaliforniaLos AngelesUnited States
| | - Yifei Zhou
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
| | - Yuyao Zhang
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
| | - Adebanjo Adedoja
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical SchoolBostonUnited States
| | - Luke M Murphy
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical SchoolBostonUnited States
| | - Armen Yerevanian
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
| | - Sinclair Emans
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
| | - Khoi Dao
- Department of Medicine and Pharmacology, University of California San DiegoSan DiegoUnited States
| | - Zhaozhi Li
- Biomedical Informatics Core, Massachusetts General Hospital and Harvard Medical SchooCambridgeUnited States
| | - Nicholas D Peterson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Jeramie Watrous
- Department of Medicine and Pharmacology, University of California San DiegoSan DiegoUnited States
| | - Mohit Jain
- Department of Medicine and Pharmacology, University of California San DiegoSan DiegoUnited States
| | - Sudeshna Das
- Biomedical Informatics Core, Massachusetts General Hospital and Harvard Medical SchooCambridgeUnited States
| | - Read Pukkila-Worley
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern CaliforniaLos AngelesUnited States
| | - Alexander A Soukas
- Center for Genomic Medicine and Diabetes Unit, Endocrine Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
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Lee S, Cheung-See-Kit M, Williams TA, Yamout N, Zufferey R. The glycosomal alkyl-dihydroxyacetonephosphate synthase TbADS is essential for the synthesis of ether glycerophospholipids in procyclic trypanosomes. Exp Parasitol 2018; 185:71-78. [PMID: 29355496 DOI: 10.1016/j.exppara.2018.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/14/2018] [Indexed: 01/15/2023]
Abstract
Glycerophospholipids are the main constituents of the biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans. The present work reports the characterization of the alkyl-dihydroxyacetonephosphate synthase TbADS that catalyzes the committed step in ether glycerophospholipid biosynthesis. TbADS localizes to the glycosomal lumen. TbADS complemented a null mutant of Leishmania major lacking alkyl-dihydroxyacetonephosphate synthase activity and restored the formation of normal form of the ether lipid based virulence factor lipophosphoglycan. Despite lacking alkyl-dihydroxyacetonephosphate synthase activity, a null mutant of TbADS in procyclic trypanosomes remained viable and exhibited normal growth. Comprehensive analysis of cellular glycerophospholipids showed that TbADS was involved in the biosynthesis of all ether glycerophospholipid species, primarily found in the PE and PC classes.
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Affiliation(s)
- Sungsu Lee
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Melanie Cheung-See-Kit
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Tyler A Williams
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Nader Yamout
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Rachel Zufferey
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA.
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3
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Ritchie SA, Akita H, Takemasa I, Eguchi H, Pastural E, Nagano H, Monden M, Doki Y, Mori M, Jin W, Sajobi TT, Jayasinghe D, Chitou B, Yamazaki Y, White T, Goodenowe DB. Metabolic system alterations in pancreatic cancer patient serum: potential for early detection. BMC Cancer 2013; 13:416. [PMID: 24024929 PMCID: PMC3847543 DOI: 10.1186/1471-2407-13-416] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 09/02/2013] [Indexed: 12/17/2022] Open
Abstract
Background The prognosis of pancreatic cancer (PC) is one of the poorest among all cancers, due largely to the lack of methods for screening and early detection. New biomarkers for identifying high-risk or early-stage subjects could significantly impact PC mortality. The goal of this study was to find metabolic biomarkers associated with PC by using a comprehensive metabolomics technology to compare serum profiles of PC patients to healthy control subjects. Methods A non-targeted metabolomics approach based on high-resolution, flow-injection Fourier transform ion cyclotron resonance mass spectrometry (FI-FTICR-MS) was used to generate comprehensive metabolomic profiles containing 2478 accurate mass measurements from the serum of Japanese PC patients (n=40) and disease-free subjects (n=50). Targeted flow-injection tandem mass spectrometry (FI-MS/MS) assays for specific metabolic systems were developed and used to validate the FI-FTICR-MS results. A FI-MS/MS assay for the most discriminating metabolite discovered by FI-FTICR-MS (PC-594) was further validated in two USA Caucasian populations; one comprised 14 PCs, six intraductal papillary mucinous neoplasims (IPMN) and 40 controls, and a second comprised 1000 reference subjects aged 30 to 80, which was used to create a distribution of PC-594 levels among the general population. Results FI-FTICR-MS metabolomic analysis showed significant reductions in the serum levels of metabolites belonging to five systems in PC patients compared to controls (all p<0.000025). The metabolic systems included 36-carbon ultra long-chain fatty acids, multiple choline-related systems including phosphatidylcholines, lysophosphatidylcholines and sphingomyelins, as well as vinyl ether-containing plasmalogen ethanolamines. ROC-AUCs based on FI-MS/MS of selected markers from each system ranged between 0.93 ±0.03 and 0.97 ±0.02. No significant correlations between any of the systems and disease-stage, gender, or treatment were observed. Biomarker PC-594 (an ultra long-chain fatty acid), was further validated using an independently-collected US Caucasian population (blinded analysis, n=60, p=9.9E-14, AUC=0.97 ±0.02). PC-594 levels across 1000 reference subjects showed an inverse correlation with age, resulting in a drop in the AUC from 0.99 ±0.01 to 0.90 ±0.02 for subjects aged 30 to 80, respectively. A PC-594 test positivity rate of 5.0% in low-risk reference subjects resulted in a PC sensitivity of 87% and a significant improvement in net clinical benefit based on decision curve analysis. Conclusions The serum metabolome of PC patients is significantly altered. The utility of serum metabolite biomarkers, particularly PC-594, for identifying subjects with elevated risk of PC should be further investigated.
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Plasmalogens the neglected regulatory and scavenging lipid species. Chem Phys Lipids 2011; 164:573-89. [PMID: 21723266 DOI: 10.1016/j.chemphyslip.2011.06.008] [Citation(s) in RCA: 224] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 06/08/2011] [Accepted: 06/14/2011] [Indexed: 12/17/2022]
Abstract
Plasmalogens are a class of phospholipids carrying a vinyl ether bond in sn-1 and an ester bond in sn-2 position of the glycerol backbone. Although they are widespread in all tissues and represent up to 18% of the total phospholipid mass in humans, their physiological function is still poorly understood. The aim of this review is to give an overview over the current knowledge in plasmalogen biology and pathology with an emphasis on neglected aspects of their involvement in neurological and metabolic diseases. Furthermore a better understanding of plasmalogen biology in health and disease could also lead to the development of better diagnostic and prognostic biomarkers for vascular and metabolic diseases such as obesity and diabetes mellitus, inflammation, neuro-degeneration and cancer.
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5
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Pastural E, Ritchie S, Lu Y, Jin W, Kavianpour A, Khine Su-Myat K, Heath D, Wood PL, Fisk M, Goodenowe DB. Novel plasma phospholipid biomarkers of autism: mitochondrial dysfunction as a putative causative mechanism. Prostaglandins Leukot Essent Fatty Acids 2009; 81:253-64. [PMID: 19608392 DOI: 10.1016/j.plefa.2009.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 06/12/2009] [Accepted: 06/15/2009] [Indexed: 12/30/2022]
Abstract
Autism is a neurological disorder that manifests as noticeable behavioral and developmental abnormalities predominantly in males between the ages of 2 and 10. Although the genetics, biochemistry and neuropathology of this disease have been extensively studied, underlying causal factors to this disease have remained elusive. Using a longitudinal trial design in which three plasma samples were collected from 15 autistic and 12 non-autistic age-matched controls over the course of 1 year, universal and unambiguous alterations in lipid metabolism were observed. Biomarkers of fatty acid elongation and desaturation (poly-unsaturated long chain fatty acids (PUFA) and/or saturated very long chain fatty acids (VLCFA)-containing ethanolamine phospholipids) were statistically elevated in all autistic subjects. In all 8 of the affected/non-affected sibling pairs, the affected sibling had higher levels of these biomarkers than the unaffected sibling. Exposure of neurons, astrocytes and hepatocytes in vitro to elevated extracellular glutamate levels resulted in lipid biomarker changes indistinguishable from those observed in autistic subjects. Glutamate stress also resulted in in vitro decreased levels of reduced glutathione (GSH), methionine and cysteine, in a similar way to the decreases we observed in autism plasma. Impaired mitochondrial fatty acid oxidation, elevated plasma VLCFAs, and glutamate toxicity as putative causal factors in the biochemistry, neuropathology, and gender bias in autism are discussed.
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Affiliation(s)
- Elodie Pastural
- Phenomenome Discoveries Inc., 204-407 Downey Road, Saskatoon, Saskatchewan, Canada S7N 4L8
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6
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Leisewitz AV, Urrutia CR, Martinez GR, Loyola G, Bronfman M. A PPARs cross-talk concertedly commits C6 glioma cells to oligodendrocytes and induces enzymes involved in myelin synthesis. J Cell Physiol 2008; 217:367-76. [DOI: 10.1002/jcp.21509] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
In this review, we describe the current state of knowledge about the biochemistry of mammalian peroxisomes, especially human peroxisomes. The identification and characterization of yeast mutants defective either in the biogenesis of peroxisomes or in one of its metabolic functions, notably fatty acid beta-oxidation, combined with the recognition of a group of genetic diseases in man, wherein these processes are also defective, have provided new insights in all aspects of peroxisomes. As a result of these and other studies, the indispensable role of peroxisomes in multiple metabolic pathways has been clarified, and many of the enzymes involved in these pathways have been characterized, purified, and cloned. One aspect of peroxisomes, which has remained ill defined, is the transport of metabolites across the peroxisomal membrane. Although it is clear that mammalian peroxisomes under in vivo conditions are closed structures, which require the active presence of metabolite transporter proteins, much remains to be learned about the permeability properties of mammalian peroxisomes and the role of the four half ATP-binding cassette (ABC) transporters therein.
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Affiliation(s)
- Ronald J A Wanders
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Disease, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
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8
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Murphy EJ, Huang HM, Cowburn RF, Lannfelt L, Gibson GE. Phospholipid mass is increased in fibroblasts bearing the Swedish amyloid precursor mutation. Brain Res Bull 2006; 69:79-85. [PMID: 16464688 DOI: 10.1016/j.brainresbull.2005.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 10/19/2005] [Accepted: 10/27/2005] [Indexed: 11/20/2022]
Abstract
Phospholipid changes occur in brain regions affected by Alzheimer disease (AD), including a marked reduction in plasmalogens, which could diminish brain function either by directly altering signaling events or by bulk membrane effects. However, model systems for studying the dynamics of lipid biosynthesis in AD are lacking. To determine if fibroblasts bearing the Swedish amyloid precursor protein (swAPP) mutation are a useful model to study the mechanism(s) associated with altered phospholipid biosynthesis in AD, we examined the steady-state phospholipid mass and composition of fibroblasts, including plasmalogens. We found a 15% increase in total phospholipid mass, accounted for by a 24% increase in the combined total of phosphatidylethanolamine and plasmanylethanolamine mass and a 19% increase in the combined total of phosphatidylcholine (PtdCho) and plasmanycholine (PakCho) mass in the swAPP mutant bearing fibroblasts. Cholesterol mass was unchanged in these cells. The changes in phospholipid mass did not alter the cellular molar composition of the phospholipids nor the cholesterol to phospholipid ratio. While plasmalogen mass was not altered, the ratio of choline plasmalogen (PlsCho) mass to PtdCho+PakCho mass was decreased 16% and there was a 14% reduction in the proportion of PlsCho as a percent of total phospholipids in the swAPP mutant bearing fibroblasts. This change in choline plasmalogen is consistent with the reported decreases in plasmalogen proportions in affected regions of AD brain, suggesting that these cells may serve as a useful model to determine the mechanism underlying changes in plasmalogen biosynthesis in AD brain.
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Affiliation(s)
- Eric J Murphy
- Department of Pharmacology, Physiology, and Therapeutics and Department of Chemistry, School of Medicine and Health Sciences, University of North Dakota, 501 N. Columbia Road, Room 3700, Grand Forks, ND 58202-9037, USA.
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9
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André A, Juanéda P, Sébédio JL, Chardigny JM. Plasmalogen metabolism-related enzymes in rat brain during aging: influence of n-3 fatty acid intake. Biochimie 2006; 88:103-11. [PMID: 16046045 DOI: 10.1016/j.biochi.2005.06.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 06/09/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
Plasmalogens (Pls) are phospholipids containing a vinyl-ether bond at the sn-1 position of the glycerol backbone. They represent between 1/2 and 2/3 of the ethanolamine phospholipids in the brain. During aging, the Pls content in human brain falls down. However, the role of Pls metabolism-related enzymes in the regulation of Pls levels remains to be determined. Dihydroxyacetone phosphate acyltransferase (DHAP-AT) is the enzyme involved in the first step of Pls biosynthesis. In the brain, a phospholipase A2, which selectively acts on Pls, has been isolated (Pls-PLA2s). In this work, we aimed to evaluate the impact of DHAP-AT (a key enzyme of Pls biosynthesis) and Pls-PLA2 (a specific Pls degradation enzyme) on the evolution of Pls content in the rat brain during aging. The influence of n-3 fatty acid intake was also evaluated. Littermates from two generations of n-3 deficient rats were fed an equilibrated diet containing either alpha-LNA alone or with two doses of DHA. After weaning, 3, 9 or 21 months of diet, rats were sacrificed. Enzymatic assays were performed, Pls levels were assessed and the sn-2 position of ethanolamine Pls was analyzed. DHAP-AT activity significantly increased between weaning and 3 months with a concomitant increase of brain Pls, which reached maximal levels after 9 months. Then, Pls levels and DHAP-AT activity significantly decreased while Pls-PLA2s activity significantly increased. Dietary n-3 fatty acids had no effect on DHAP-AT activity and on Pls levels. In conclusion, the increase of brain Pls content in the first part of the life may be related to the high increase of DHAP-AT activity, probably stimulated by DHA. In aged animals, the decrease of Pls levels may mainly be caused to an increase of their degradation by Pls-PLA2. Dietary DHA may not oppose the physiologic aging.
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Affiliation(s)
- A André
- UMR Inra-ENESAD Flaveur, vision et Comportement du consommateur, 17, rue Sully, BP 86510, 21065 Dijon cedex, France
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André A, Tessier C, Brétillon L, Sébédio JL, Chardigny JM. In situ hybridization of dihydroxyacetone phosphate acyltransferase, the regulating enzyme involved in plasmalogen biosynthesis. ACTA ACUST UNITED AC 2005; 136:142-7. [PMID: 15893598 DOI: 10.1016/j.molbrainres.2005.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2004] [Revised: 01/12/2005] [Accepted: 01/14/2005] [Indexed: 11/30/2022]
Abstract
In situ hybridization can be carried out using different methods. The experimenter has to choose various parameters: the type of tissue fixation, the time of incubation, and the duration of the exposure time. All these parameters are determinant for the sensitivity and the resolution of this technique. This publication of technical aspects described different experiments performed for in situ hybridization on liver tissue. We may conclude on the parameters to optimize each step of the hybridization procedure. Moreover, this technique could be transposed to the brain and applied to little structures with a light expression of DHAP-AT.
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Affiliation(s)
- Agnès André
- INRA, Unité de Nutrition Lipidique, 17 rue Sully, BP 86510, 21065 Dijon Cedex, France
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Brites P, Waterham HR, Wanders RJA. Functions and biosynthesis of plasmalogens in health and disease. Biochim Biophys Acta Mol Cell Biol Lipids 2004; 1636:219-31. [PMID: 15164770 DOI: 10.1016/j.bbalip.2003.12.010] [Citation(s) in RCA: 288] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Accepted: 12/15/2003] [Indexed: 11/29/2022]
Abstract
Plasmalogens (1-O-alk-1'-enyl-2-acyl glycerophospholipids) constitute a special class of phospholipids characterized by the presence of a vinyl-ether bond at the sn-1 position. Although long considered as biological peculiarities, interest in this group of phospholipids has grown in recent years, thanks to the realization that plasmalogens are involved in different human diseases. In this review, we summarize the current state of knowledge with respect to the enzymatic synthesis of plasmalogens, the characteristic topology of the enzymes involved and the biological roles that have been assigned to plasmalogens.
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Affiliation(s)
- Pedro Brites
- Department of Clinical Chemistry, Academic Medical Center, Lab Genetic Metabolic Diseases, F0-224, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands
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12
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Murphy EJ, Prows DR, Stiles T, Schroeder F. Liver and intestinal fatty acid-binding protein expression increases phospholipid content and alters phospholipid fatty acid composition in L-cell fibroblasts. Lipids 2000; 35:729-38. [PMID: 10941873 DOI: 10.1007/s11745-000-0579-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Although fatty acid-binding proteins (FABP) differentially affect fatty acid uptake, nothing is known regarding their role(s) in determining cellular phospholipid levels and phospholipid fatty acid composition. The effects of liver (L)- and intestinal (I)-FABP expression on these parameters were determined using stably transfected L-cells. Expression of L- and I-FABP increased cellular total phospholipid mass (nmol/mg protein) 1.7- and 1.3-fold relative to controls, respectively. L-FABP expression increased the masses of choline glycerophospholipids (ChoGpl) 1.5-fold, phosphatidylserine (PtdSer) 5.6-fold, ethanolamine glycerophospholipids 1.4-fold, sphingomyelin 1.7-fold, and phosphatidylinositol 2.6-fold. In contrast, I-FABP expression only increased the masses of ChoGpl and PtdSer, 1.2- and 3.1-fold, respectively. Surprisingly, both L- and I-FABP expression increased ethanolamine plasmalogen mass 1.6- and 1.1-fold, respectively, while choline plasmalogen mass was increased 2.3- and 1.7-fold, respectively. The increase in phospholipid levels resulted in dramatic 48 and 33% decreases in the cholesterol-to-phospholipid ratio in L- and I-FABP expressing cells, respectively. L-FABP expression generally increased polyunsaturated fatty acids, primarily by increasing 20:4n-6 and 22:6n-3, while decreasing 18:1n-9 and 16:1n-7. I-FABP expression generally increased only 20:4n-6 proportions. Hence, expression of both I- and L-FABP differentially affected phospholipid mass, class composition, and acyl chain composition. Although both proteins enhanced phospholipid synthesis, the effect of L-FABP was much greater, consistent with previous work suggesting that these two FABP differentially affect lipid metabolism.
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Affiliation(s)
- E J Murphy
- Department of Physiology and Pharmacology, Texas A & M University, TVMC, College Station 77843-4466, USA.
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Murphy EJ, Schapiro MB, Rapoport SI, Shetty HU. Phospholipid composition and levels are altered in Down syndrome brain. Brain Res 2000; 867:9-18. [PMID: 10837793 DOI: 10.1016/s0006-8993(00)02205-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phospholipid composition (mol %) and levels (nmol/mg protein) were determined in postmortem frontal cortical and cerebellar gray matter from older Down Syndrome (DS) patients (age range 38-68 years) and from control subjects. Neither DS nor control tissue exhibited any age-dependent alteration in phospholipid composition or levels. Total phospholipid content was significantly reduced approximately 20% in DS frontal cortex and cerebellum relative to these regions in control tissue. Individual phospholipid levels were also reduced in DS frontal cortex and cerebellum, including a specific 37% decrease in phosphatidylinositol (PtdIns) and a nearly 35% decrease in ethanolamine plasmalogen. Because of the large decrease in phospholipid content in DS brain, the cholesterol/phospholipid ratio was calculated for each group. There was no significant difference in this ratio between groups, indicative of compensatory changes to keep the cholesterol/phospholipid ratio constant. Despite the large changes in DS brain phospholipid levels, significant changes in composition were limited to a 18% decrease in PtdIns mol % and a 22% increase in the mol % of sphingomyelin. These results suggest either a decrease in membrane phospholipids due to a loss of dendrites and dendritic spines, or a general defect in brain lipid metabolism in older DS subjects. The proportionally greater alterations in PtdIns and PlsEtn levels, indicate that the metabolism of these two phospholipids was affected to a greater extent than the other phospholipids. Further, because these changes are found in both the frontal cortical and cerebellar gray matter, they likely are related to the Down syndrome condition rather than to Alzheimer neuropathology.
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Affiliation(s)
- E J Murphy
- Section on Brain Physiology and Metabolism, National Institute on Aging, National Institutes of Health, Building 10, Room 6C103, Bethesda, MD 20892, USA
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Murphy EJ, Zhang H, Sorbi S, Rapoport SI, Gibson GE. Phospholipid composition and levels are not altered in fibroblasts bearing presenilin-1 mutations. Brain Res Bull 2000; 52:207-12. [PMID: 10822162 DOI: 10.1016/s0361-9230(00)00257-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Lipid alterations have been reported in brain regions affected by Alzheimer disease (AD). The mechanisms causing these changes are poorly understood because it is difficult to study dynamic, biochemical processes in post-mortem brain. Fibroblasts derived from AD patients offer an alternative model to study disease-related alterations in lipid metabolism. Therefore, we measured the phospholipid levels and composition of fibroblasts from individuals bearing two different presenilin-1 mutations and compared these values to appropriate control fibroblasts. There were no differences between groups in phospholipid composition or in individual phospholipid levels, including the plasmalogens. Cholesterol levels and the cholesterol/phospholipid ratio were not different between presenilin-1 mutation bearing and control fibroblasts. Although these presenilin-1 mutation bearing fibroblasts have a number of biochemical changes related to AD, the absence of a change in phospholipid levels suggests that under these conditions, these cells are not useful in studying the mechanisms underlying the alterations in brain phospholipid levels associated with AD. However, these results do not preclude the possible use of other fibroblasts bearing AD-related mutations, e.g., APP mutations, to examine AD-related changes in brain lipid metabolism, or of these fibroblasts under different conditions.
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Affiliation(s)
- E J Murphy
- Section on Brain Physiology and Metabolism, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
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Murphy EJ, Stiles T, Schroeder F. Sterol carrier protein-2 expression alters phospholipid content and fatty acyl composition in L-cell fibroblasts. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)32387-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Sul HS, Wang D. Nutritional and hormonal regulation of enzymes in fat synthesis: studies of fatty acid synthase and mitochondrial glycerol-3-phosphate acyltransferase gene transcription. Annu Rev Nutr 1998; 18:331-51. [PMID: 9706228 DOI: 10.1146/annurev.nutr.18.1.331] [Citation(s) in RCA: 193] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The activities of critical enzymes in fatty acid and triacylglycerol biosynthesis are tightly controlled by different nutritional, hormonal, and developmental conditions. Feeding previously fasted animals high-carbohydrate, low-fat diets causes a dramatic induction of enzymes-such as fatty acid synthase (FAS) and mitochondrial glycerol-3-phosphate acyltransferase (GPAT)-involved in fatty acid and triacylglycerol synthesis. During fasting and refeeding, transcription of these two enzymes is coordinately regulated by nutrients and hormones, such as glucose, insulin, glucagon, glucocorticoids, and thyroid hormone. Insulin stimulates transcription of the FAS and mitochondrial GPAT genes, and glucagon antagonizes the insulin effect through the cis-acting elements within the promoters and their bound trans-acting factors. This review discusses advances made in the understanding of the transcriptional regulation of FAS and mitochondrial GPAT genes, with emphasis on elucidation of the mechanisms by which multiple nutrients and hormones achieve their effects.
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Affiliation(s)
- H S Sul
- Department of Nutritional Sciences, University of California, Berkeley 94720, USA.
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17
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Abstract
Peroxisomes were long believed to play only a minor role in cellular metabolism but it is now clear that they catalyze a number of important functions. The importance of peroxisomes in humans is stressed by the existence of a group of genetic diseases in man in which one or more peroxisomal functions are impaired. Most of the functions known to take place in peroxisomes have to do with lipids. Indeed, peroxisomes are capable of 1. fatty acid beta-oxidation 2. fatty acid alpha-oxidation 3. synthesis of cholesterol and other isoprenoids 4. ether-phospholipid synthesis and 5. biosynthesis of polyunsaturated fatty acids. In Chapters 2-6 we will discuss the functional organization and enzymology of these pathways in detail. Furthermore, attention is paid to the permeability properties of peroxisomes with special emphasis on recent studies which suggest that peroxisomes are closed structures containing specific membrane proteins for transport of metabolites. Finally, the disorders of peroxisomal lipid metabolism will be discussed.
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Affiliation(s)
- R J Wanders
- Department of Clinical Chemistry, University of Amsterdam, The Netherlands
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18
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Singh H, Beckman K, Poulos A. Evidence of two catalytically active carnitine medium/long chain acyltransferases in rat liver peroxisomes. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)37465-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Poulos A, Christodoulou J, Chow CW, Goldblatt J, Paton BC, Orii T, Suzuki Y, Shimozawa N. Peroxisomal assembly defects: clinical, pathologic, and biochemical findings in two patients in a newly identified complementation group. J Pediatr 1995; 127:596-9. [PMID: 7562283 DOI: 10.1016/s0022-3476(95)70121-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We describe the clinical, pathologic, and biochemical findings for two peroxisome-deficient patients in a newly identified complementation group. Both patients had biochemical findings typical of patients with peroxisome biogenesis disorders. However, whereas one patient had the typical clinicopathologic features of Zellweger syndrome, the other patient's phenotype was atypical.
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Affiliation(s)
- A Poulos
- Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, South Australia
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20
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Singh H, Poulos A. Substrate specificity of rat liver mitochondrial carnitine palmitoyl transferase I: evidence against alpha-oxidation of phytanic acid in rat liver mitochondria. FEBS Lett 1995; 359:179-83. [PMID: 7867794 DOI: 10.1016/0014-5793(95)00035-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The two branched chain fatty acids pristanic acid (2,6,10,14-tetramethylpentadecanoic acid) and phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) were converted to co-enzyme A thioesters by rat liver mitochondrial outer membranes. However, these branched chain fatty acids could not be converted to pristanoyl and phytanoyl carnitines, respectively, by mitochondrial outer membranes. As expected, the unbranched long chain fatty acids, stearic acid and palmitic acid, were rapidly converted to stearoyl and palmitoyl carnitines, respectively, by mitochondrial outer membranes. These observations indicate that the branched chain fatty acids could not be transported into mitochondria. The data presented strongly suggest that in rat liver, alpha-oxidation of phytanic acid occurs in organelles other than mitochondria.
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Affiliation(s)
- H Singh
- Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, Australia
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21
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Hayashi H, Oohashi M. Incorporation of acetyl-CoA generated from peroxisomal beta-oxidation into ethanolamine plasmalogen of rat liver. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1254:319-25. [PMID: 7857972 DOI: 10.1016/0005-2760(94)00194-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have reported that peroxisomal beta-oxidation has an anabolic function, supplying acetyl-CoA for biosyntheses of bile acids and phospholipids. Here we deal with its role in the biosynthesis of the subclasses of ethanolamine- and choline-containing phosphoglycerides (EPG, CPG, respectively). Rats were fed for 2 weeks on chow containing 0.25% clofibrate, which inhibits cholesterol and bile acid biosyntheses, but stimulates peroxisomal beta-oxidation. [1-14C]Lignoceric acid, which is exclusively degraded by peroxisomal beta-oxidation to acetyl-CoA, was intravenously injected, and 3 h later the rats were killed. The EPG-rich and CPG-rich fractions were prepared from the liver. When they were treated with phospholipase A2, the radioactivity was predominantly recovered in the 1-radyl group. The radioactivity in EPG was easily dissociated with HCl vapor, and the lipid containing radioactivity was found to be a fatty aldehyde mixture consisting of steary aldehyde (approx. 58%) palmityl aldehyde (approx. 40%) and oleyl aldehyde (approx. 2%). Thus, in the case of EPG, acetyl-CoA from peroxisomal beta-oxidation is incorporated mainly into the 1-alkenyl group of ethanolamine plasmalogen. The radioactivity in CPG, however, was found in fatty alcohol (formed from fatty acid), but not in alkylglycerol after reduction of the fraction with Vitride. Thus, in the case of CPG, acetyl-CoA from peroxisomal beta-oxidation is exclusively incorporated into the 1-acyl group of diacyl glycerophosphocholine, but not into the 1-alkyl group. The above results were supported by the results of phospholipase C treatment. The above data indicate that peroxisomal beta-oxidation plays a role in supplying acetyl-CoA for 1-alkenyl group of plasmalogen-type phospholipid, but this channel may open only to synthesis of EPG, and almost not to CPG.
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Affiliation(s)
- H Hayashi
- Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan
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22
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Abstract
Plasmalogens (1-O-1'-alkenyl-2-acylglycerophospholipids) and to a lesser extent the 1-O-alkyl analogs are ubiquitous and in some cases major constituents of mammalian cellular membranes and of anaerobic bacteria. In archaebacteria polar lipids of the cell envelope are either diphytanylglycerolipids or bipolar macrocyclic tetraether lipids capable of forming covalently linked 'bilayers'. Information on the possible role of ether lipids as membrane constituents has been obtained from studies on the biophysical properties of model membranes consisting of these lipids. In addition, effects of modified ether lipid content on properties of biological membranes have been investigated using microorganisms or mammalian cells which carry genetic defects in ether lipid biosynthesis. Differential utilization of ether glycerophospholipids by specific phospholipases might play a role in the generation of lipid mediators that are involved in signal transduction. A possible function of plasmalogens as antioxidants has been demonstrated with cultured cells and might play a role in serum lipoproteins. Synthetic ether lipid analogs exert cytostatic effects, most likely by interfering with membrane structure and by specific interaction with components of signal transmission pathways, such as phospholipase C and protein kinase C.
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Affiliation(s)
- F Paltauf
- Institut für Biochemie und Lebensmittelchemie der Technischen Universität, Graz, Austria
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Peroxisomal beta-oxidation of branched chain fatty acids in rat liver. Evidence that carnitine palmitoyltransferase I prevents transport of branched chain fatty acids into mitochondria. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36911-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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