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Levitt DE, Bourgeois BL, Rodríguez-Graciani KM, Molina PE, Simon L. Alcohol Impairs Bioenergetics and Differentiation Capacity of Myoblasts from Simian Immunodeficiency Virus-Infected Female Macaques. Int J Mol Sci 2024; 25:2448. [PMID: 38397125 PMCID: PMC10888832 DOI: 10.3390/ijms25042448] [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: 01/15/2024] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Alcohol misuse and HIV independently induce myopathy. We previously showed that chronic binge alcohol (CBA) administration, with or without simian immunodeficiency virus (SIV), decreases differentiation capacity of male rhesus macaque myoblasts. We hypothesized that short-term alcohol and CBA/SIV would synergistically decrease differentiation capacity and impair bioenergetic parameters in female macaque myoblasts. Myoblasts from naïve (CBA-/SIV-), vehicle [VEH]/SIV, and CBA/SIV (N = 4-6/group) groups were proliferated (3 days) and differentiated (5 days) with 0 or 50 mM ethanol (short-term). CBA/SIV decreased differentiation and increased non-mitochondrial oxygen consumption rate (OCR) versus naïve and/or VEH/SIV. Short-term alcohol decreased differentiation; increased maximal and non-mitochondrial OCR, mitochondrial reactive oxygen species (ROS) production, and aldolase activity; and decreased glycolytic measures, ATP production, mitochondrial membrane potential (ΔΨm), and pyruvate kinase activity. Mitochondrial ROS production was closely associated with mitochondrial network volume, and differentiation indices were closely associated with key bioenergetic health and function parameters. Results indicate that short-term alcohol and CBA non-synergistically decrease myoblast differentiation capacity. Short-term alcohol impaired myoblast glycolytic function, driving the bioenergetic deficit. Results suggest potentially differing mechanisms underlying decreased differentiation capacity with short-term alcohol and CBA, highlighting the need to elucidate the impact of different alcohol use patterns on myopathy.
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Affiliation(s)
- Danielle E. Levitt
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; (D.E.L.); (B.L.B.); (K.M.R.-G.); (P.E.M.)
- Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA
| | - Brianna L. Bourgeois
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; (D.E.L.); (B.L.B.); (K.M.R.-G.); (P.E.M.)
- Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Keishla M. Rodríguez-Graciani
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; (D.E.L.); (B.L.B.); (K.M.R.-G.); (P.E.M.)
- Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Patricia E. Molina
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; (D.E.L.); (B.L.B.); (K.M.R.-G.); (P.E.M.)
- Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Liz Simon
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA; (D.E.L.); (B.L.B.); (K.M.R.-G.); (P.E.M.)
- Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Agarwal AK, Tunison K, Vale G, McDonald JG, Li X, Scherer PE, Horton JD, Garg A. Regulated adipose tissue-specific expression of human AGPAT2 in lipodystrophic Agpat2-null mice results in regeneration of adipose tissue. iScience 2023; 26:107806. [PMID: 37752957 PMCID: PMC10518674 DOI: 10.1016/j.isci.2023.107806] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/28/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023] Open
Abstract
Genetic loss of Agpat2 in humans and mice results in congenital generalized lipodystrophy with near-total loss of adipose tissue and predisposition to develop insulin resistance, diabetes mellitus, hepatic steatosis, and hypertriglyceridemia. The mechanism by which Agpat2 deficiency results in loss of adipose tissue remains unknown. We studied this by re-expressing human AGPAT2 (hAGPAT2) in Agpat2-null mice, regulated by doxycycline. In both sexes of Agpat2-null mice, adipose-tissue-specific re-expression of hAGPAT2 resulted in partial regeneration of both white and brown adipose tissue (but only 30%-50% compared with wild-type mice), which had molecular signatures of adipocytes, including leptin secretion. Furthermore, the stromal vascular fraction cells of regenerated adipose depots differentiated ex vivo only with doxycycline, suggesting the essential role of Agpat2 in adipocyte differentiation. Turning off expression of hAGPAT2 in vivo resulted in total loss of regenerated adipose tissue, clear evidence that Agpat2 is essential for adipocyte differentiation in vivo.
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Affiliation(s)
- Anil K. Agarwal
- Section of Nutrition and Metabolic Diseases, Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Katie Tunison
- Section of Nutrition and Metabolic Diseases, Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Goncalo Vale
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jeffrey G. McDonald
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xilong Li
- Peter O’Donnell Jr. School of Public Health, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Philipp E. Scherer
- Touchstone Center for Diabetes Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jay D. Horton
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Abhimanyu Garg
- Section of Nutrition and Metabolic Diseases, Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
- Center for Human Nutrition, UT Southwestern Medical Center, Dallas, TX 75390, USA
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Kimura T, Kimura AK, Epand RM. Systematic crosstalk in plasmalogen and diacyl lipid biosynthesis for their differential yet concerted molecular functions in the cell. Prog Lipid Res 2023; 91:101234. [PMID: 37169310 DOI: 10.1016/j.plipres.2023.101234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/29/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
Plasmalogen is a major phospholipid of mammalian cell membranes. Recently it is becoming evident that the sn-1 vinyl-ether linkage in plasmalogen, contrasting to the ester linkage in the counterpart diacyl glycerophospholipid, yields differential molecular characteristics for these lipids especially related to hydrocarbon-chain order, so as to concertedly regulate biological membrane processes. A role played by NMR in gaining information in this respect, ranging from molecular to tissue levels, draws particular attention. We note here that a broad range of enzymes in de novo synthesis pathway of plasmalogen commonly constitute that of diacyl glycerophospholipid. This fact forms the basis for systematic crosstalk that not only controls a quantitative balance between these lipids, but also senses a defect causing loss of lipid in either pathway for compensation by increase of the counterpart lipid. However, this inherent counterbalancing mechanism paradoxically amplifies imbalance in differential effects of these lipids in a diseased state on membrane processes. While sharing of enzymes has been recognized, it is now possible to overview the crosstalk with growing information for specific enzymes involved. The overview provides a fundamental clue to consider cell and tissue type-dependent schemes in regulating membrane processes by plasmalogen and diacyl glycerophospholipid in health and disease.
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Affiliation(s)
- Tomohiro Kimura
- Department of Chemistry & Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, USA.
| | - Atsuko K Kimura
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
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Dorninger F, Werner ER, Berger J, Watschinger K. Regulation of plasmalogen metabolism and traffic in mammals: The fog begins to lift. Front Cell Dev Biol 2022; 10:946393. [PMID: 36120579 PMCID: PMC9471318 DOI: 10.3389/fcell.2022.946393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/25/2022] [Indexed: 12/15/2022] Open
Abstract
Due to their unique chemical structure, plasmalogens do not only exhibit distinct biophysical and biochemical features, but require specialized pathways of biosynthesis and metabolization. Recently, major advances have been made in our understanding of these processes, for example by the attribution of the gene encoding the enzyme, which catalyzes the final desaturation step in plasmalogen biosynthesis, or by the identification of cytochrome C as plasmalogenase, which allows for the degradation of plasmalogens. Also, models have been presented that plausibly explain the maintenance of adequate cellular levels of plasmalogens. However, despite the progress, many aspects around the questions of how plasmalogen metabolism is regulated and how plasmalogens are distributed among organs and tissues in more complex organisms like mammals, remain unresolved. Here, we summarize and interpret current evidence on the regulation of the enzymes involved in plasmalogen biosynthesis and degradation as well as the turnover of plasmalogens. Finally, we focus on plasmalogen traffic across the mammalian body - a topic of major importance, when considering plasmalogen replacement therapies in human disorders, where deficiencies in these lipids have been reported. These involve not only inborn errors in plasmalogen metabolism, but also more common diseases including Alzheimer's disease and neurodevelopmental disorders.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria,*Correspondence: Fabian Dorninger, ; Katrin Watschinger,
| | - Ernst R. Werner
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Katrin Watschinger
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria,*Correspondence: Fabian Dorninger, ; Katrin Watschinger,
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Kleiboeker B, Lodhi IJ. Peroxisomal regulation of energy homeostasis: Effect on obesity and related metabolic disorders. Mol Metab 2022; 65:101577. [PMID: 35988716 PMCID: PMC9442330 DOI: 10.1016/j.molmet.2022.101577] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/01/2022] [Accepted: 08/16/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Peroxisomes are single membrane-bound organelles named for their role in hydrogen peroxide production and catabolism. However, their cellular functions extend well beyond reactive oxygen species (ROS) metabolism and include fatty acid oxidation of unique substrates that cannot be catabolized in mitochondria, and synthesis of ether lipids and bile acids. Metabolic functions of peroxisomes involve crosstalk with other organelles, including mitochondria, endoplasmic reticulum, lipid droplets and lysosomes. Emerging studies suggest that peroxisomes are important regulators of energy homeostasis and that disruption of peroxisomal functions influences the risk for obesity and the associated metabolic disorders, including type 2 diabetes and hepatic steatosis. SCOPE OF REVIEW Here, we focus on the role of peroxisomes in ether lipid synthesis, β-oxidation and ROS metabolism, given that these functions have been most widely studied and have physiologically relevant implications in systemic metabolism and obesity. Efforts are made to mechanistically link these cellular and systemic processes. MAJOR CONCLUSIONS Circulating plasmalogens, a form of ether lipids, have been identified as inversely correlated biomarkers of obesity. Ether lipids influence metabolic homeostasis through multiple mechanisms, including regulation of mitochondrial morphology and respiration affecting brown fat-mediated thermogenesis, and through regulation of adipose tissue development. Peroxisomal β-oxidation also affects metabolic homeostasis through generation of signaling molecules, such as acetyl-CoA and ROS that inhibit hydrolysis of stored lipids, contributing to development of hepatic steatosis. Oxidative stress resulting from increased peroxisomal β-oxidation-generated ROS in the context of obesity mediates β-cell lipotoxicity. A better understanding of the roles peroxisomes play in regulating and responding to obesity and its complications will provide new opportunities for their treatment.
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Honsho M, Mawatari S, Fujiki Y. ATP8B2-Mediated Asymmetric Distribution of Plasmalogens Regulates Plasmalogen Homeostasis and Plays a Role in Intracellular Signaling. Front Mol Biosci 2022; 9:915457. [PMID: 35832735 PMCID: PMC9271795 DOI: 10.3389/fmolb.2022.915457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/23/2022] [Indexed: 12/21/2022] Open
Abstract
Plasmalogens are a subclass of glycerophospholipid containing vinyl-ether bond at the sn-1 position of glycerol backbone. Ethanolamine-containing plasmalogens (plasmalogens) are major constituents of cellular membranes in mammalian cells and de novo synthesis of plasmalogens largely contributes to the homeostasis of plasmalogens. Plasmalogen biosynthesis is regulated by a feedback mechanism that senses the plasmalogen level in the inner leaflet of the plasma membrane and regulates the stability of fatty acyl-CoA reductase 1 (Far1), a rate-limiting enzyme for plasmalogen biosynthesis. However, the molecular mechanism underlying the localization of plasmalogens in cytoplasmic leaflet of plasma membrane remains unknown. To address this issue, we attempted to identify a potential transporter of plasmalogens from the outer to the inner leaflet of plasma membrane by focusing on phospholipid flippases, type-IV P-type adenosine triphosphatases (P4-ATPase), localized in the plasma membranes. We herein show that knockdown of ATP8B2 belonging to the class-1 P4-ATPase enhances localization of plasmalogens but not phosphatidylethanolamine in the extracellular leaflet and impairs plasmalogen-dependent degradation of Far1. Furthermore, phosphorylation of protein kinase B (AKT) is downregulated by lowering the expression of ATP8B2, which leads to suppression of cell growth. Taken together, these results suggest that enrichment of plasmalogens in the cytoplasmic leaflet of plasma membranes is mediated by ATP8B2 and this asymmetric distribution of plasmalogens is required for sensing plasmalogens as well as phosphorylation of AKT.
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Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka, Japan
- *Correspondence: Masanori Honsho, ; Yukio Fujiki,
| | - Shiro Mawatari
- Institute of Rheological Functions of Food, Fukuoka, Japan
| | - Yukio Fujiki
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka, Japan
- Graduate School of Science, University of Hyogo, Hyogo, Japan
- *Correspondence: Masanori Honsho, ; Yukio Fujiki,
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Sailer S, Lackner K, Pras-Raves ML, Wever EJ, van Klinken JB, Dane AD, Geley S, Koch J, Golderer G, Werner-Felmayer G, Keller MA, Zwerschke W, Vaz FM, Werner ER, Watschinger K. Adaptations of the 3T3-L1 adipocyte lipidome to defective ether lipid catabolism upon alkylglycerol monooxygenase knockdown. J Lipid Res 2022; 63:100222. [PMID: 35537527 PMCID: PMC9192799 DOI: 10.1016/j.jlr.2022.100222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 10/24/2022] Open
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The Key Role of Peroxisomes in Follicular Growth, Oocyte Maturation, Ovulation, and Steroid Biosynthesis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7982344. [PMID: 35154572 PMCID: PMC8831076 DOI: 10.1155/2022/7982344] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/04/2022] [Indexed: 02/06/2023]
Abstract
The absence of peroxisomes can cause disease in the human reproductive system, including the ovaries. The available peroxisomal gene-knockout female mouse models, which exhibit pathological changes in the ovary and reduced fertility, are listed in this review. Our review article provides the first systematic presentation of peroxisomal regulation and its possible functions in the ovary. Our immunofluorescence results reveal that peroxisomes are present in all cell types in the ovary; however, peroxisomes exhibit different numerical abundances and strong heterogeneity in their protein composition among distinct ovarian cell types. The peroxisomal compartment is strongly altered during follicular development and during oocyte maturation, which suggests that peroxisomes play protective roles in oocytes against oxidative stress and lipotoxicity during ovulation and in the survival of oocytes before conception. In addition, the peroxisomal compartment is involved in steroid synthesis, and peroxisomal dysfunction leads to disorder in the sexual hormone production process. However, an understanding of the cellular and molecular mechanisms underlying these physiological and pathological processes is lacking. To date, no effective treatment for peroxisome-related disease has been developed, and only supportive methods are available. Thus, further investigation is needed to resolve peroxisome deficiency in the ovary and eventually promote female fertility.
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Metabolomic Alteration in the Mouse Distal Colonic Mucosa after Oral Gavage with Oxalobacter formigenes. Metabolites 2020; 10:metabo10100405. [PMID: 33065971 PMCID: PMC7650779 DOI: 10.3390/metabo10100405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 12/03/2022] Open
Abstract
Oxalobacter formigenes has been investigated for years due to its proposed ability to produce a secretagogue compound that initiates net intestinal oxalate secretion, thereby theoretically reducing circulating oxalate and risk of kidney stone formation. Strains which have been shown to exhibit this function in vivo across native tissue include the human strain, HC1, and the wild rat strain, OxWR. While previous work on these secretagogue-relevant strains has focused on profiling their metabolome and lipidome in vitro, efforts to characterize their influence on host intestinal mucosal biochemistry in vivo are yet to be reported. Much work has been done over the years with O. formigenes in relation to the secretagogue hypothesis, but it has never been clearly demonstrated that this microorganism is capable of inducing metabolic changes in native host tissue, which would be expected with the production of a transport-inducing compound. In this work, we show how the distal colonic mucosal metabolomic profile in a mouse model exhibited significant changes in the levels of a variety of metabolites as a result of oral gavage with O. formigenes HC1. Among these significant metabolites was nicotinic acid, an essential nutrient shown in past work to be produced in the gut by the native microbiome. Our finding that the in vivo biochemical state of the distal colon was altered with O. formigenes lends support to the secretagogue hypothesis and serves as a pioneering step in characterizing the biochemical interplay between O. formigenes and the mammalian host.
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Honsho M, Tanaka M, Zoeller RA, Fujiki Y. Distinct Functions of Acyl/Alkyl Dihydroxyacetonephosphate Reductase in Peroxisomes and Endoplasmic Reticulum. Front Cell Dev Biol 2020; 8:855. [PMID: 33042986 PMCID: PMC7517302 DOI: 10.3389/fcell.2020.00855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/10/2020] [Indexed: 01/03/2023] Open
Abstract
Plasmalogens are a subclass of ether glycerophospholipids characterized by a vinyl-ether bond at the sn-1 position of the glycerol backbone. Plasmalogen biosynthesis is initiated in peroxisomes. At the third step of plasmalogen synthesis, alkyl-dihydroxyacetonephosphate (DHAP) is enzymatically reduced to 1-alkyl-sn-glycero-3-phospate by acyl/alkyl DHAP reductase (ADHAPR), whose activity is found in both peroxisomes and microsomes. We herein show that knockdown of ADHAPR in HeLa cells reduced the synthesis of ethanolamine plasmalogen (PlsEtn), similar to the Chinese hamster ovary cell mutant FAA.K1B deficient in ADHAPR activity. Endogenous ADHAPR and ectopically expressed FLAG-tagged ADHAPR were localized to peroxisomes and endoplasmic reticulum (ER) as a type I integral membrane protein in HeLa cells. ADHAPR targets to peroxisomes via a Pex19p-dependent class I pathway. In addition, it is also inserted into the ER via the SRP-dependent mechanism. The ADHAPR mutant lacking the N-terminal domain preferentially targets to the ER, restoring the reduced level of PlsEtn synthesis in FAA.K1B cell. In contrast, the expression of full-length ADHAPR in the mutant cells elevates the synthesis of phosphatidylethanolamine, but not PlsEtn. Taken together, these results suggest that the third step of plasmalogen synthesis is mediated by ER-localized ADHAPR.
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Affiliation(s)
- Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Megumi Tanaka
- Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, Japan
| | - Raphael A Zoeller
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, United States
| | - Yukio Fujiki
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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Liu J, Lu W, Shi B, Klein S, Su X. Peroxisomal regulation of redox homeostasis and adipocyte metabolism. Redox Biol 2019; 24:101167. [PMID: 30921635 PMCID: PMC6434164 DOI: 10.1016/j.redox.2019.101167] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 03/01/2019] [Accepted: 03/10/2019] [Indexed: 12/26/2022] Open
Abstract
Peroxisomes are ubiquitous cellular organelles required for specific pathways of fatty acid oxidation and lipid synthesis, and until recently their functions in adipocytes have not been well appreciated. Importantly, peroxisomes host many oxygen-consumption reactions and play a major role in generation and detoxification of reactive oxygen species (ROS) and reactive nitrogen species (RNS), influencing whole cell redox status. Here, we review recent progress in peroxisomal functions in lipid metabolism as related to ROS/RNS metabolism and discuss the roles of peroxisomal redox homeostasis in adipogenesis and adipocyte metabolism. We provide a framework for understanding redox regulation of peroxisomal functions in adipocytes together with testable hypotheses for developing therapies for obesity and the related metabolic diseases.
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Affiliation(s)
- Jingjing Liu
- Department of Biochemistry and Molecular Biology, Soochow University College of Medicine, Suzhou, 215123, China
| | - Wen Lu
- Department of Biochemistry and Molecular Biology, Soochow University College of Medicine, Suzhou, 215123, China; Department of Endocrinology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Bimin Shi
- Department of Endocrinology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Samuel Klein
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Xiong Su
- Department of Biochemistry and Molecular Biology, Soochow University College of Medicine, Suzhou, 215123, China; Center for Human Nutrition, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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12
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Zhu XG, Nicholson Puthenveedu S, Shen Y, La K, Ozlu C, Wang T, Klompstra D, Gultekin Y, Chi J, Fidelin J, Peng T, Molina H, Hang HC, Min W, Birsoy K. CHP1 Regulates Compartmentalized Glycerolipid Synthesis by Activating GPAT4. Mol Cell 2019; 74:45-58.e7. [PMID: 30846317 DOI: 10.1016/j.molcel.2019.01.037] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/26/2018] [Accepted: 01/25/2019] [Indexed: 01/10/2023]
Abstract
Cells require a constant supply of fatty acids to survive and proliferate. Fatty acids incorporate into membrane and storage glycerolipids through a series of endoplasmic reticulum (ER) enzymes, but how these enzymes are regulated is not well understood. Here, using a combination of CRISPR-based genetic screens and unbiased lipidomics, we identified calcineurin B homologous protein 1 (CHP1) as a major regulator of ER glycerolipid synthesis. Loss of CHP1 severely reduces fatty acid incorporation and storage in mammalian cells and invertebrates. Mechanistically, CHP1 binds and activates GPAT4, which catalyzes the initial rate-limiting step in glycerolipid synthesis. GPAT4 activity requires CHP1 to be N-myristoylated, forming a key molecular interface between the two proteins. Interestingly, upon CHP1 loss, the peroxisomal enzyme, GNPAT, partially compensates for the loss of ER lipid synthesis, enabling cell proliferation. Thus, our work identifies a conserved regulator of glycerolipid metabolism and reveals plasticity in lipid synthesis of proliferating cells.
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Affiliation(s)
- Xiphias Ge Zhu
- Laboratory of Metabolic Regulation and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Shirony Nicholson Puthenveedu
- Laboratory of Metabolic Regulation and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, Graz 8036, Austria
| | - Yihui Shen
- Department of Chemistry and Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Konnor La
- Laboratory of Metabolic Regulation and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Can Ozlu
- Laboratory of Metabolic Regulation and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Tim Wang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Diana Klompstra
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Yetis Gultekin
- Laboratory of Apoptosis and Cancer Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Jingyi Chi
- Laboratory of Molecular Metabolism, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Justine Fidelin
- The Proteomics Resource Center, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Tao Peng
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Henrik Molina
- The Proteomics Resource Center, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Wei Min
- Department of Chemistry and Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Kıvanç Birsoy
- Laboratory of Metabolic Regulation and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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Hu XD, Pan BZ, Fu Q, Niu L, Chen MS, Xu ZF. De novo transcriptome assembly of the eight major organs of Sacha Inchi (Plukenetia volubilis) and the identification of genes involved in α-linolenic acid metabolism. BMC Genomics 2018; 19:380. [PMID: 29788925 PMCID: PMC5964912 DOI: 10.1186/s12864-018-4774-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 05/09/2018] [Indexed: 12/12/2022] Open
Abstract
Background Sacha Inchi (Plukenetia volubilis L.), which belongs to the Euphorbiaceae, has been considered a new potential oil crop because of its high content of polyunsaturated fatty acids in its seed oil. The seed oil especially contains high amounts of α-linolenic acid (ALA), which is useful for the prevention of various diseases. However, little is known about the genetic information and genome sequence of Sacha Inchi, which has largely hindered functional genomics and molecular breeding studies. Results In this study, a de novo transcriptome assembly based on transcripts sequenced in eight major organs, including roots, stems, shoot apexes, mature leaves, male flowers, female flowers, fruits, and seeds of Sacha Inchi was performed, resulting in a set of 124,750 non-redundant putative transcripts having an average length of 851 bp and an N50 value of 1909 bp. Organ-specific unigenes analysis revealed that the most organ-specific transcripts are found in female flowers (2244 unigenes), whereas a relatively small amount of unigenes are detected to be expressed specifically in other organs with the least in stems (24 unigenes). A total of 42,987 simple sequence repeats (SSRs) were detected, which will contribute to the marker assisted selection breeding of Sacha Inchi. We analyzed expression of genes related to the α-linolenic acid metabolism based on the de novo assembly and annotation transcriptome in Sacha Inchi. It appears that Sacha Inchi accumulates high level of ALA in seeds by strong expression of biosynthesis-related genes and weak expression of degradation-related genes. In particular, the up-regulation of FAD3 and FAD7 is consistent with high level of ALA in seeds of Sacha Inchi compared with in other organs. Meanwhile, several transcription factors (ABI3, LEC1 and FUS3) may regulate key genes involved in oil accumulation in seeds of Sacha Inchi. Conclusions The transcriptome of major organs of Sacha Inchi has been sequenced and de novo assembled, which will expand the genetic information for functional genomic studies of Sacha Inchi. In addition, the identification of candidate genes involved in ALA metabolism will provide useful resources for the genetic improvement of Sacha Inchi and the metabolic engineering of ALA biosynthesis in other plants. Electronic supplementary material The online version of this article (10.1186/s12864-018-4774-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiao-Di Hu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bang-Zhen Pan
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | - Qiantang Fu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | - Longjian Niu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | - Mao-Sheng Chen
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China
| | - Zeng-Fu Xu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.
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Xue LL, Chen HH, Jiang JG. Implications of glycerol metabolism for lipid production. Prog Lipid Res 2017; 68:12-25. [PMID: 28778473 DOI: 10.1016/j.plipres.2017.07.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 07/06/2017] [Accepted: 07/31/2017] [Indexed: 12/13/2022]
Abstract
Triacylglycerol (TAG) is an important product in oil-producing organisms. Biosynthesis of TAG can be completed through either esterification of fatty acids to glycerol backbone, or through esterification of 2-monoacylglycerol. This review will focus on the former pathway in which two precursors, fatty acid and glycerol-3-phosphate (G3P), are required for TAG formation. Tremendous progress has been made about the enzymes or genes that regulate the biosynthetic pathway of TAG. However, much attention has been paid to the fatty acid provision and the esterification process, while the possible role of G3P is largely neglected. Glycerol is extensively studied on its usage as carbon source for value-added products, but the modification of glycerol metabolism, which is directly associated with G3P synthesis, is seldom recognized in lipid investigations. The relevance among glycerol metabolism, G3P synthesis and lipid production is described, and the role of G3P in glycerol metabolism and lipid production are discussed in detail with an emphasis on how G3P affects lipid production through the modulation of glycerol metabolism. Observations of lipid metabolic changes due to glycerol related disruption in mammals, plants, and microorganisms are introduced. Altering glycerol metabolism results in the changes of final lipid content. Possible regulatory mechanisms concerning the relationship between glycerol metabolism and lipid production are summarized.
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Affiliation(s)
- Lu-Lu Xue
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China; (b)Industrial Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Hao-Hong Chen
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China
| | - Jian-Guo Jiang
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China.
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15
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Regnault C, Willison J, Veyrenc S, Airieau A, Méresse P, Fortier M, Fournier M, Brousseau P, Raveton M, Reynaud S. Metabolic and immune impairments induced by the endocrine disruptors benzo[a]pyrene and triclosan in Xenopus tropicalis. CHEMOSPHERE 2016; 155:519-527. [PMID: 27153234 DOI: 10.1016/j.chemosphere.2016.04.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/09/2016] [Accepted: 04/12/2016] [Indexed: 06/05/2023]
Abstract
Despite numerous studies suggesting that amphibians are highly sensitive to cumulative anthropogenic stresses, the role played by endocrine disruptors (EDs) in the decline of amphibian populations remains unclear. EDs have been extensively studied in adult amphibians for their capacity to disturb reproduction by interfering with the sexual hormone axis. Here, we studied the in vivo responses of Xenopus tropicalis males exposed to environmentally relevant concentrations of each ED, benzo[a]pyrene (BaP) and triclosan (TCS) alone (10 μg L(-1)) or a mixture of the two (10 μg L(-1) each) over a 24 h exposure period by following the modulation of the transcription of key genes involved in metabolic, sexual and immunity processes and the cellular changes in liver, spleen and testis. BaP, TCS and the mixture of the two all induced a marked metabolic disorder in the liver highlighted by insulin resistance-like and non-alcoholic fatty liver disease (NAFLD)-like phenotypes together with hepatotoxicity due to the impairment of lipid metabolism. For TCS and the mixture, these metabolic disorders were concomitant with modulation of innate immunity. These results confirmed that in addition to the reproductive effects induced by EDs in amphibians, metabolic disorders and immune system disruption should also be considered.
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Affiliation(s)
- Christophe Regnault
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - John Willison
- Univ. Grenoble-Alpes, Institut de recherches en technologies et Sciences pour le vivant, Laboratoire de chimie et biologie des métaux (iRTSV-LCBM), F-38000, France; CNRS, IRTSV-LCBM, F-38000, Grenoble, France; Commissariat à l'énergie atomique et aux énergies alternatives (CEA), iRTSV-LCBM, F-38000, Grenoble, France.
| | - Sylvie Veyrenc
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Antinéa Airieau
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Patrick Méresse
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, CUBE, F-38000, Grenoble, France.
| | | | | | | | - Muriel Raveton
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Stéphane Reynaud
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
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16
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Gross DA, Silver DL. Cytosolic lipid droplets: from mechanisms of fat storage to disease. Crit Rev Biochem Mol Biol 2015; 49:304-26. [PMID: 25039762 DOI: 10.3109/10409238.2014.931337] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The lipid droplet (LD) is a phylogenetically conserved organelle. In eukaryotes, it is born from the endoplasmic reticulum, but unlike its parent organelle, LDs are the only known cytosolic organelles that are micellar in structure. LDs are implicated in numerous physiological and pathophysiological functions. Many aspects of the LD has captured the attention of diverse scientists alike and has recently led to an explosion in information on the LD biogenesis, expansion and fusion, identification of LD proteomes and diseases associated with LD biology. This review will provide a brief history of this fascinating organelle and provide some contemporary views of unanswered questions in LD biogenesis.
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Affiliation(s)
- David A Gross
- Program in Cardiovascular & Metabolic Disorders, Duke-NUS Graduate Medical School Singapore , Singapore , and
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17
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Hachero-Cruzado I, Rodríguez-Rua A, Román-Padilla J, Ponce M, Fernández-Díaz C, Manchado M. Characterization of the genomic responses in early Senegalese sole larvae fed diets with different dietary triacylglycerol and total lipids levels. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2014; 12:61-73. [DOI: 10.1016/j.cbd.2014.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 12/16/2022]
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18
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Tanner LB, Chng C, Guan XL, Lei Z, Rozen SG, Wenk MR. Lipidomics identifies a requirement for peroxisomal function during influenza virus replication. J Lipid Res 2014; 55:1357-65. [PMID: 24868094 DOI: 10.1194/jlr.m049148] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Indexed: 12/13/2022] Open
Abstract
Influenza virus acquires a host-derived lipid envelope during budding, yet a convergent view on the role of host lipid metabolism during infection is lacking. Using a mass spectrometry-based lipidomics approach, we provide a systems-scale perspective on membrane lipid dynamics of infected human lung epithelial cells and purified influenza virions. We reveal enrichment of the minor peroxisome-derived ether-linked phosphatidylcholines relative to bulk ester-linked phosphatidylcholines in virions as a unique pathogenicity-dependent signature for influenza not found in other enveloped viruses. Strikingly, pharmacological and genetic interference with peroxisomal and ether lipid metabolism impaired influenza virus production. Further integration of our lipidomics results with published genomics and proteomics data corroborated altered peroxisomal lipid metabolism as a hallmark of influenza virus infection in vitro and in vivo. Influenza virus may therefore tailor peroxisomal and particularly ether lipid metabolism for efficient replication.
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Affiliation(s)
- Lukas Bahati Tanner
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore 117456
| | - Charmaine Chng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| | - Xue Li Guan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland
| | - Zhengdeng Lei
- Centre for Computational Biology, Duke-NUS Graduate Medical School, Singapore 169857 Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore 169857 Research Resources Center, University of Illinois at Chicago, Chicago, IL 60612
| | - Steven G Rozen
- Centre for Computational Biology, Duke-NUS Graduate Medical School, Singapore 169857 Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore 169857
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 NUS Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore 117456 Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland Department of Biological Sciences, National University of Singapore, Singapore 117597
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19
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D'Alimonte I, Lannutti A, Pipino C, Di Tomo P, Pierdomenico L, Cianci E, Antonucci I, Marchisio M, Romano M, Stuppia L, Caciagli F, Pandolfi A, Ciccarelli R. Wnt signaling behaves as a "master regulator" in the osteogenic and adipogenic commitment of human amniotic fluid mesenchymal stem cells. Stem Cell Rev Rep 2014; 9:642-54. [PMID: 23605563 PMCID: PMC3785124 DOI: 10.1007/s12015-013-9436-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Human amniotic fluid mesenchymal stem cells (huAFMSCs) are emerging as a promising therapeutic option in regenerative medicine. Here, we characterized huAFMSC phenotype and multipotentiality. When cultured in osteogenic medium, huAFMSC displayed a significant increase in: Alkaline Phosphatase (ALP) activity and mRNA expression, Alizarin Red S staining and Runx2 mRNA expression; whereas maintaining these cells in an adipogenic culture medium gave a time-dependent increase in PPARγ and FABP4 mRNA expression, glycerol-3-phosphate dehydrogenase (GPDH) activity and positivity to Oil Red Oil staining. These results confirm that huAFMSCs can differentiate toward osteogenic and adipogenic phenotypes. The canonical Wnt/ßcatenin signaling pathway appears to trigger huAFMSC osteoblastogenesis, since during early phases of osteogenic differentiation, the expression of Dishevelled-2 (Dvl-2), of the non-phosphorylated form of ß-catenin, and the phosphorylation of glycogen synthase kinase-3ß (GSK3ß) at serine 9 were upregulated. On the contrary, during adipogenic differentiation Dvl-2 expression decreased, whereas that of ß-catenin remained unchanged. This was associated with a late increase in GSK3ß phosphorylation. Consistent with this scenario, huAFMSCs exposure to Dickkopf-1, a selective inhibitor of the Wnt signaling, abolished Runx2 and ALP mRNA upregulation during huAFMSC osteogenic differentiation, whereas it enhanced FABP4 expression in adipocyte-differentiating cells. Taken together, these results unravel novel molecular determinants of huAFMSC commitment towards osteoblastogenesis, which may represent potential targets for directing the differentiation of these cells and improving their use in regenerative medicine. Schematic representation of Wnt pathway involved in the osteogenic and adipogenic differentiation of huAFMSCs. Our paper demonstrates that osteogenic commitment of these cells is linked to the stimulation of Wnt signal leading to the final transcriptional activation of early osteogenic markers such as RUNX-2 and ALP, mediated by β-catenin. DKK1 is a secreted Wnt antagonist that may be used as a drug to inhibit Wnt signal. In contrast, adipogenic commitment involves early inhibition of Wnt pathway leading to ubiquitination/degradation of β-catenin. This results in the transcription of PPARγ and FABP4, considered as the main initiators of adipogenesis. APC, adenomatous polyposis coli; βcat, β-catenin; CK1, casein kinase 1; DKK1, dickkopf 1; Dvl, Dishevelled; GSK3β, glycogen synthase kinase 3β; LRP5/6, low density lipoprotein receptor-related protein 5/6 ![]()
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Affiliation(s)
- Iolanda D'Alimonte
- Department of Experimental and Clinical Sciences, University "G. D'Annunzio" of Chieti-Pescara, Chieti, Italy
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20
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Abstract
Peroxisomes are often dismissed as the cellular hoi polloi, relegated to cleaning up reactive oxygen chemical debris discarded by other organelles. However, their functions extend far beyond hydrogen peroxide metabolism. Peroxisomes are intimately associated with lipid droplets and mitochondria, and their ability to carry out fatty acid oxidation and lipid synthesis, especially the production of ether lipids, may be critical for generating cellular signals required for normal physiology. Here, we review the biology of peroxisomes and their potential relevance to human disorders including cancer, obesity-related diabetes, and degenerative neurologic disease.
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21
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O'Neill HM, Holloway GP, Steinberg GR. AMPK regulation of fatty acid metabolism and mitochondrial biogenesis: implications for obesity. Mol Cell Endocrinol 2013; 366:135-51. [PMID: 22750049 DOI: 10.1016/j.mce.2012.06.019] [Citation(s) in RCA: 241] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 03/13/2012] [Accepted: 06/21/2012] [Indexed: 12/25/2022]
Abstract
Skeletal muscle plays an important role in regulating whole-body energy expenditure given it is a major site for glucose and lipid oxidation. Obesity and type 2 diabetes are causally linked through their association with skeletal muscle insulin resistance, while conversely exercise is known to improve whole body glucose homeostasis simultaneously with muscle insulin sensitivity. Exercise activates skeletal muscle AMP-activated protein kinase (AMPK). AMPK plays a role in regulating exercise capacity, skeletal muscle mitochondrial content and contraction-stimulated glucose uptake. Skeletal muscle AMPK is also thought to be important for regulating fatty acid metabolism; however, direct genetic evidence in this area is currently lacking. This review will discuss the current paradigms regarding the influence of AMPK in regulating skeletal muscle fatty acid metabolism and mitochondrial biogenesis at rest and during exercise, and highlight the potential implications in the development of insulin resistance.
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Affiliation(s)
- Hayley M O'Neill
- University of Melbourne, Department of Medicine, St. Vincent's Institute of Medical Research, Melbourne, Victoria, Australia.
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22
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Kang NE, Ha AW, Kim JY, Kim WK. Resveratrol inhibits the protein expression of transcription factors related adipocyte differentiation and the activity of matrix metalloproteinase in mouse fibroblast 3T3-L1 preadipocytes. Nutr Res Pract 2012; 6:499-504. [PMID: 23346299 PMCID: PMC3542439 DOI: 10.4162/nrp.2012.6.6.499] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/12/2012] [Accepted: 11/05/2012] [Indexed: 12/18/2022] Open
Abstract
This study attempted to investigate the effects of resveratrol on the differentiation of adipocytes. After cells were treated with various concentrations of resveratrol (0, 10, 20, and 40 µmol/L), adipocyte proliferation, the protein expression of transcription factors, and MMPs' activities were determined. Cell proliferation was inhibited more within 4 days of incubation (P < 0.05), and lipid accumulation in adipocyte was significantly inhibited by 93.8%, 92.4% and 91.5%, respectively, after two days of 10, 20, and 40 µmol/L resveratrol treatment (P < 0.05). Six days of incubation with the three resveratrol concentrations caused a significantly decreases of 63%, 59.9%, and 25.1% GPDH activity as a dose-dependent response. The triglyceride concentration also decreased significantly with the increase of resveratrol concentration (P < 0.05). The protein expression of CCAAT/enhancer-binding protein (C/EBPβ) was decreased significantly by 56% and 30% while PPARγ was significantly reduced by 57% and 15% with resveratrol treatments of 20 and 40 µmol/L, respectively (P < 0.05). The protein expression of C/EBPα was decreased by 83%, 74%, and 38% to increased dosage levels, with significance determined for this decrease from 20 µmol/L of resveratrol. The protein expression of fatty acid binding protein (FABP4) was decreased significantly by 88%, 72%, and 46% with the increase of resveratrol concentration. The activity of MMP-2 was decreased significantly by 84%, 70%, and 63% while MMP-9 activity was decreased significantly by 74%, 62%, and 39% with the increased resveratrol concentrations of 10, 20, and 40 µmol/L, respectively (P < 0.05).
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Affiliation(s)
- Nam E Kang
- Department of Food and Nutrition, Eulji University, Seongnam, Gyunggi 461-723, Korea
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23
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Martens K, Bottelbergs A, Peeters A, Jacobs F, Espeel M, Carmeliet P, Van Veldhoven PP, Baes M. Peroxisome deficient aP2-Pex5 knockout mice display impaired white adipocyte and muscle function concomitant with reduced adrenergic tone. Mol Genet Metab 2012; 107:735-47. [PMID: 23141464 DOI: 10.1016/j.ymgme.2012.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/16/2012] [Accepted: 10/16/2012] [Indexed: 12/21/2022]
Abstract
Peroxisomes are essential for intermediary lipid metabolism, but the role of these organelles has been primarily studied in the liver. We recently generated aP2-Pex5 conditional knockout mice that due to the nonselectivity of the aP2 promoter, not only had dysfunctional peroxisomes in the adipose tissue but also in the central and peripheral nervous system, besides some other tissues. Peroxisomes were however intact in the liver, heart, pancreas and muscle. Surprisingly, these mice not only showed dysfunctional white adipose tissue with increased fat mass and reduced lipolysis but also the skeletal muscle was affected including impaired shivering thermogenesis, reduced motor performance and increased insulin resistance. Non-shivering thermogenesis by brown adipose tissue was not altered. Strongly reduced levels of plasma adrenaline and to a lesser extent noradrenaline, impaired expression of catecholamine synthesizing enzymes in the adrenal medulla and reversal of all pathologies after administration of the β-agonist isoproterenol indicated that β-adrenergic signaling was reduced. Based on normal white adipose and muscle function in Nestin-Pex5 and Wnt-Pex5 knockout mice respectively, it is unlikely that peroxisome absence from the central and peripheral nervous system caused the phenotype. We conclude that peroxisomal metabolism is necessary to maintain the adrenergic tone in mice, which in turn determines metabolic homeostasis.
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Affiliation(s)
- Katrin Martens
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
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Vijayaraj P, Jashal CB, Vijayakumar A, Rani SH, Venkata Rao D, Rajasekharan R. A bifunctional enzyme that has both monoacylglycerol acyltransferase and acyl hydrolase activities. PLANT PHYSIOLOGY 2012; 160:667-83. [PMID: 22915575 PMCID: PMC3461547 DOI: 10.1104/pp.112.202135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 08/16/2012] [Indexed: 05/23/2023]
Abstract
Monoacylglycerol acyltransferase (MGAT) catalyzes the synthesis of diacylglycerol, the precursor of triacylglycerol biosynthesis and an important signaling molecule. Here, we describe the isolation and characterization of the peanut (Arachis hypogaea) MGAT gene. The soluble enzyme utilizes invariant histidine-62 and aspartate-67 residues of the acyltransferase motif for its MGAT activity. A sequence analysis revealed the presence of a hydrolase (GXSXG) motif, and enzyme assays revealed the presence of monoacylglycerol (MAG) and lysophosphatidylcholine (LPC) hydrolytic activities, indicating the bifunctional nature of the enzyme. The overexpression of the MGAT gene in yeast (Saccharomyces cerevisiae) caused an increase in triacylglycerol accumulation. Similar to the peanut MGAT, the Arabidopsis (Arabidopsis thaliana) homolog (At1g52760) also exhibited both acyltransferase and hydrolase activities. Interestingly, the yeast homolog lacks the conserved HX(4)D motif, and it is deficient in the acyltransferase function but exhibits MAG and LPC hydrolase activities. This study demonstrates the presence of a soluble MGAT/hydrolase in plants. The predicted three-dimensional homology modeling and substrate docking suggested the presence of two separate substrate (MAG and LPC)-binding sites in a single polypeptide. Our study describes a soluble bifunctional enzyme that has both MGAT and hydrolase functions.
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Lodhi IJ, Yin L, Jensen-Urstad APL, Funai K, Coleman T, Baird JH, El Ramahi MK, Razani B, Song H, Fu-Hsu F, Turk J, Semenkovich CF. Inhibiting adipose tissue lipogenesis reprograms thermogenesis and PPARγ activation to decrease diet-induced obesity. Cell Metab 2012; 16:189-201. [PMID: 22863804 PMCID: PMC3467338 DOI: 10.1016/j.cmet.2012.06.013] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 03/07/2012] [Accepted: 06/22/2012] [Indexed: 10/28/2022]
Abstract
De novo lipogenesis in adipocytes, especially with high fat feeding, is poorly understood. We demonstrate that an adipocyte lipogenic pathway encompassing fatty acid synthase (FAS) and PexRAP (peroxisomal reductase activating PPARγ) modulates endogenous PPARγ activation and adiposity. Mice lacking FAS in adult adipose tissue manifested increased energy expenditure, increased brown fat-like adipocytes in subcutaneous adipose tissue, and resistance to diet-induced obesity. FAS knockdown in embryonic fibroblasts decreased PPARγ transcriptional activity and adipogenesis. FAS-dependent alkyl ether phosphatidylcholine species were associated with PPARγ and treatment of 3T3-L1 cells with one such ether lipid increased PPARγ transcriptional activity. PexRAP, a protein required for alkyl ether lipid synthesis, was associated with peroxisomes and induced during adipogenesis. PexRAP knockdown in cells decreased PPARγ transcriptional activity and adipogenesis. PexRAP knockdown in mice decreased expression of PPARγ-dependent genes and reduced diet-induced adiposity. These findings suggest that inhibiting PexRAP or related lipogenic enzymes could treat obesity and diabetes.
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Affiliation(s)
- Irfan J Lodhi
- Division of Endocrinology, Metabolism & Lipid Research, Washington University School of Medicine, St. Louis, MO 63110, USA
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26
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Agarwal AK. Lysophospholipid acyltransferases: 1-acylglycerol-3-phosphate O-acyltransferases. From discovery to disease. Curr Opin Lipidol 2012; 23:290-302. [PMID: 22777291 DOI: 10.1097/mol.0b013e328354fcf4] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE OF REVIEW Over the past several years, many more isoforms for the same enzymes, specifically for 1-acylglycerol-3-phosphate O-acyltransferases (AGPATs), have been cloned and studied. In this review, we summarize their biochemical features and discuss their functional role. RECENT FINDINGS The most significant role of these AGPATs appeared from our observation of AGPAT2 in the biology of adipose tissue (adipocytes) in humans and mice. Other isoforms are shown to be implicated in lung, reproductive and cardiac muscle function and in the cause of cancer. In-vitro substrate specificities of these AGPATs also suggest the in-vivo role of these AGPATs in remodeling of several of the glycerophospholipids. SUMMARY Despite significant progress in understanding the role of these AGPATs, much is still to be discovered in terms of how each of these AGPATs function in the presence or absence of other AGPATs and what their functional role might be.
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Affiliation(s)
- Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
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27
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Liu J, Liang S, Liu X, Brown JA, Newman KE, Sunkara M, Morris AJ, Bhatnagar S, Li X, Pujol A, Graf GA. The absence of ABCD2 sensitizes mice to disruptions in lipid metabolism by dietary erucic acid. J Lipid Res 2012; 53:1071-9. [PMID: 22493092 PMCID: PMC3351814 DOI: 10.1194/jlr.m022160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 03/12/2012] [Indexed: 01/10/2023] Open
Abstract
ABCD2 (D2) is a peroxisomal transporter that is highly abundant in adipose tissue and promotes the oxidation of long-chain MUFA. Erucic acid (EA, 22:1ω9) reduces very long chain saturated fatty acids in patients with X-linked adrenoleukodystrophy but promotes dyslipidemia and dilated cardiomyopathy in rats. To determine the role of D2 in the metabolism of EA, we challenged wild-type and D2 deficient mice (D2 KO) with an enriched EA diet. In D2 KO mice, dietary EA resulted in the rapid expansion of adipose tissue, adipocyte hypertrophy, hepatic steatosis, and the loss of glycemic control. However, D2 had no impact on the development of obesity phenotypes in two models of diet-induced obesity. Although there was a significant increase in EA in liver of D2 KO mice, it constituted less than 2% of all fatty acids. Metabolites of EA (20:1, 18:1, and 16:1) were elevated, particularly 18:1, which accounted for 50% of all fatty acids. These data indicate that the failure to metabolize EA in adipose results in hepatic metabolism of EA, disruption of the fatty acid profile, and the development of obesity and reveal an essential role for D2 in the protection from dietary EA.
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Affiliation(s)
- Jingjing Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Shuang Liang
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Xiaoxi Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - J. Andrew Brown
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Kylie E. Newman
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Manjula Sunkara
- Cardiovascular Research Center, University of Kentucky, Lexington, KY
| | - Andrew J. Morris
- Cardiovascular Research Center, University of Kentucky, Lexington, KY
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Saloni Bhatnagar
- Kentucky Pediatric Research Institute, University of Kentucky, Lexington, KY
| | - Xiangan Li
- Cardiovascular Research Center, University of Kentucky, Lexington, KY
- Kentucky Pediatric Research Institute, University of Kentucky, Lexington, KY
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory and Institut de Neuropatologia, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Spain, and Center for Biomedical Research on Rare Diseases (CIBERER), Spain
| | - Gregory A. Graf
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
- Cardiovascular Research Center, University of Kentucky, Lexington, KY
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
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28
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Gene expression profiles analyzed by DNA sequencing of cDNA clones constructed from porcine preadipocytes and adipocytes. Genes Genomics 2012. [DOI: 10.1007/s13258-011-0075-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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29
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Coleman RA, Mashek DG. Mammalian triacylglycerol metabolism: synthesis, lipolysis, and signaling. Chem Rev 2011; 111:6359-86. [PMID: 21627334 PMCID: PMC3181269 DOI: 10.1021/cr100404w] [Citation(s) in RCA: 202] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Rosalind A Coleman
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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30
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Collins JM, Neville MJ, Pinnick KE, Hodson L, Ruyter B, van Dijk TH, Reijngoud DJ, Fielding MD, Frayn KN. De novo lipogenesis in the differentiating human adipocyte can provide all fatty acids necessary for maturation. J Lipid Res 2011; 52:1683-92. [PMID: 21677304 DOI: 10.1194/jlr.m012195] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The primary products of de novo lipogenesis (DNL) are saturated fatty acids, which confer adverse cellular effects. Human adipocytes differentiated with no exogenous fat accumulated triacylglycerol (TG) in lipid droplets and differentiated normally. TG composition showed the products of DNL (saturated fatty acids from 12:0 to 18:0) together with unsaturated fatty acids (particularly 16:1n-7 and 18:1n-9) produced by elongation/desaturation. There was parallel upregulation of expression of genes involved in DNL and in fatty acid elongation and desaturation, suggesting coordinated control of expression. Enzyme products (desaturation ratios, elongation ratios, and total pathway flux) were also correlated with mRNA levels. We used (13)C-labeled substrates to study the pathway of DNL. Glucose (5 mM or 17.5 mM in the medium) provided less than half the carbon used for DNL (42% and 47%, respectively). Glutamine (2 mM) provided 9-10%, depending upon glucose concentration. In contrast, glucose provided most (72%) of the carbon of TG-glycerol. Pathway analysis using mass isotopomer distribution analysis (MIDA) revealed that the pathway for conversion of glucose to palmitate is complex. DNL in human fat cells is tightly coupled with further modification of fatty acids to produce a range of saturated and unsaturated fatty acids consistent with normal maturation.
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Affiliation(s)
- Jennifer M Collins
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
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31
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Kuhajda FP, Aja S, Tu Y, Han WF, Medghalchi SM, El Meskini R, Landree LE, Peterson JM, Daniels K, Wong K, Wydysh EA, Townsend CA, Ronnett GV. Pharmacological glycerol-3-phosphate acyltransferase inhibition decreases food intake and adiposity and increases insulin sensitivity in diet-induced obesity. Am J Physiol Regul Integr Comp Physiol 2011; 301:R116-30. [PMID: 21490364 DOI: 10.1152/ajpregu.00147.2011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Storage of excess calories as triglycerides is central to obesity and its associated disorders. Glycerol-3-phosphate acyltransferases (GPATs) catalyze the initial step in acylglyceride syntheses, including triglyceride synthesis. We utilized a novel small-molecule GPAT inhibitor, FSG67, to investigate metabolic consequences of systemic pharmacological GPAT inhibition in lean and diet-induced obese (DIO) mice. FSG67 administered intraperitoneally decreased body weight and energy intake, without producing conditioned taste aversion. Daily FSG67 (5 mg/kg, 15.3 μmol/kg) produced gradual 12% weight loss in DIO mice beyond that due to transient 9- to 10-day hypophagia (6% weight loss in pair-fed controls). Continued FSG67 maintained the weight loss despite return to baseline energy intake. Weight was lost specifically from fat mass. Indirect calorimetry showed partial protection by FSG67 against decreased rates of oxygen consumption seen with hypophagia. Despite low respiratory exchange ratio due to a high-fat diet, FSG67-treated mice showed further decreased respiratory exchange ratio, beyond pair-fed controls, indicating enhanced fat oxidation. Chronic FSG67 increased glucose tolerance and insulin sensitivity in DIO mice. Chronic FSG67 decreased gene expression for lipogenic enzymes in white adipose tissue and liver and decreased lipid accumulation in white adipose, brown adipose, and liver tissues without signs of damage. RT-PCR showed decreased gene expression for orexigenic hypothalamic neuropeptides AgRP or NPY after acute and chronic systemic FSG67. FSG67 given intracerebroventricularly (100 and 320 nmol icv) produced 24-h weight loss and feeding suppression, indicating contributions from direct central nervous system sites of action. Together, these data point to GPAT as a new potential therapeutic target for the management of obesity and its comorbidities.
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Affiliation(s)
- Francis P Kuhajda
- Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N. Wolfe St., Baltimore, MD 21205, USA
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32
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Kheterpal I, Ku G, Coleman L, Yu G, Ptitsyn AA, Floyd ZE, Gimble JM. Proteome of human subcutaneous adipose tissue stromal vascular fraction cells versus mature adipocytes based on DIGE. J Proteome Res 2011; 10:1519-27. [PMID: 21261302 PMCID: PMC3070065 DOI: 10.1021/pr100887r] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Adipose tissue contains a heterogeneous population of mature adipocytes, endothelial cells, immune cells, pericytes, and preadipocytic stromal/stem cells. To date, a majority of proteomic analyses have focused on intact adipose tissue or isolated adipose stromal/stem cells in vitro. In this study, human subcutaneous adipose tissue from multiple depots (arm and abdomen) obtained from female donors was separated into populations of stromal vascular fraction cells and mature adipocytes. Out of 960 features detected by 2-D gel electrophoresis, a total of 200 features displayed a 2-fold up- or down-regulation relative to each cell population. The protein identity of 136 features was determined. Immunoblot analyses comparing SVF relative to adipocytes confirmed that carbonic anhydrase II was up-regulated in both adipose depots while catalase was up-regulated in the arm only. Bioinformatic analyses of the data set determined that cytoskeletal, glycogenic, glycolytic, lipid metabolic, and oxidative stress related pathways were highly represented as differentially regulated between the mature adipocytes and stromal vascular fraction cells. These findings extend previous reports in the literature with respect to the adipose tissue proteome and the consequences of adipogenesis. The proteins identified may have value as biomarkers for monitoring the physiology and pathology of cell populations within subcutaneous adipose depots.
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Affiliation(s)
- Indu Kheterpal
- Proteomics and Metabolomics Core Facility, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
- Protein Structural Biology, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
| | - Ginger Ku
- Proteomics and Metabolomics Core Facility, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
- Protein Structural Biology, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
| | - Liana Coleman
- Proteomics and Metabolomics Core Facility, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
| | - Gang Yu
- Stem Cell Biology Laboratory, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
| | - Andrey A. Ptitsyn
- Center for Bioinformatics, College of Veterinary Medicine and Biomedical Sciences Department of Microbiology Immunology & Pathology, Colorado State University, Fort Collins, CO 80523-1682
| | - Z. Elizabeth Floyd
- Ubiquitin Laboratory, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
| | - Jeffrey M. Gimble
- Stem Cell Biology Laboratory, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808
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33
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Honsho M, Asaoku S, Fujiki Y. Posttranslational regulation of fatty acyl-CoA reductase 1, Far1, controls ether glycerophospholipid synthesis. J Biol Chem 2010; 285:8537-42. [PMID: 20071337 DOI: 10.1074/jbc.m109.083311] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plasmalogens are a major subclass of ethanolamine and choline glycerophospholipids in which a long chain fatty alcohol is attached at the sn-1 position through a vinyl ether bond. This ether-linked alkyl bond is formed in peroxisomes by replacement of a fatty acyl chain in the intermediate 1-acyl-dihydroxyacetone phosphate with a fatty alcohol in a reaction catalyzed by alkyl dihydroxyacetone phosphate synthase. Here, we demonstrate that the enzyme fatty acyl-CoA reductase 1 (Far1) supplies the fatty alcohols used in the formation of ether-linked alkyl bonds. Far1 activity is elevated in plasmalogen-deficient cells, and conversely, the levels of this enzyme are restored to normal upon plasmalogen supplementation. Down-regulation of Far1 activity in response to plasmalogens is achieved by increasing the rate of degradation of peroxisomal Far1 protein. Supplementation of normal cells with ethanolamine and 1-O-hexadecylglycerol, which are intermediates in plasmalogen biosynthesis, accelerates degradation of Far1. Taken together, our results indicate that ether lipid biosynthesis in mammalian cells is regulated by a negative feedback mechanism that senses cellular plasmalogen levels and appropriately increases or decreases Far1.
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Affiliation(s)
- Masanori Honsho
- Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
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34
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Gimeno RE, Cao J. Thematic review series: glycerolipids. Mammalian glycerol-3-phosphate acyltransferases: new genes for an old activity. J Lipid Res 2008; 49:2079-88. [PMID: 18658143 DOI: 10.1194/jlr.r800013-jlr200] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Glycerol-3-phosphate acyltransferases (GPATs; EC2.3.1.15) catalyze the first step in the de novo synthesis of neutral lipids (triglycerides) and glycerophospholipids. The existence of multiple enzyme isoforms with GPAT activity was predicted many years ago when GPAT activities with distinct kinetic profiles and sensitivity to inhibitors were characterized in two subcellular compartments, mitochondria and microsomes. We now know that mammals have at least four GPAT isoforms with distinct tissue distribution and function. GPAT1 is the major mitochondrial GPAT isoform and is characterized by its resistance to sulfhydryl-modifying reagents, such as N-ethylmaleimide (NEM). GPAT2 is a minor NEM-sensitive mitochondrial isoform. The activity referred to as microsomal GPAT is encoded by two closely related genes, GPAT3 and GPAT4. GPAT isoforms are important regulators of cellular triglyceride and phospholipid content, and may channel fatty acids toward particular metabolic fates. Overexpression and knock-out studies suggest that GPAT isoforms can play important roles in the development of hepatic steatosis, insulin resistance, and obesity; GPAT isoforms are also important for lactation. This review summarizes the current state of knowledge on mammalian GPAT isoforms.
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Affiliation(s)
- Ruth E Gimeno
- Cardiovascular and Metabolic Diseases, Wyeth Research, Cambridge, MA 02140, USA.
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35
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Visser WF, van Roermund CWT, Ijlst L, Hellingwerf KJ, Waterham HR, Wanders RJA. First identification of a 2-ketoglutarate/isocitrate transport system in mammalian peroxisomes and its characterization. Biochem Biophys Res Commun 2006; 348:1224-31. [PMID: 16919238 DOI: 10.1016/j.bbrc.2006.07.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 07/12/2006] [Indexed: 11/19/2022]
Abstract
Peroxisomes contain specific transporter proteins required for the translocation of various metabolites across its membrane. The presence of several members of the ATP-binding cassette (ABC) transporter family is well established, and the characterization of transporters for adenine nucleotides and (pyro)phosphate in the peroxisomal membrane has been described recently. Previously published data strongly suggest the presence of additional transporters that facilitate the translocation of reducing equivalents and acetyl-units across the peroxisomal membrane. In this paper, we demonstrate the presence of transporter activity for 2-ketoglutarate and isocitrate in the peroxisomal membrane, by functional reconstitution of bovine kidney peroxisomal membrane protein in proteoliposomes. This transporter activity is assumed to be required to sustain the activity of intraperoxisomal isocitrate-dehydrogenase, which is involved in the regeneration of NADPH in the peroxisomal matrix.
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Affiliation(s)
- Wouter F Visser
- University of Amsterdam, Academic Medical Centre, Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Amsterdam, The Netherlands
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36
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Vankoningsloo S, De Pauw A, Houbion A, Tejerina S, Demazy C, de Longueville F, Bertholet V, Renard P, Remacle J, Holvoet P, Raes M, Arnould T. CREB activation induced by mitochondrial dysfunction triggers triglyceride accumulation in 3T3-L1 preadipocytes. J Cell Sci 2006; 119:1266-82. [PMID: 16537646 DOI: 10.1242/jcs.02848] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Several mitochondrial pathologies are characterized by lipid redistribution and microvesicular cell phenotypes resulting from triglyceride accumulation in lipid-metabolizing tissues. However, the molecular mechanisms underlying abnormal fat distribution induced by mitochondrial dysfunction remain poorly understood. In this study, we show that inhibition of respiratory complex III by antimycin A as well as inhibition of mitochondrial protein synthesis trigger the accumulation of triglyceride vesicles in 3T3-L1 fibroblasts. We also show that treatment with antimycin A triggers CREB activation in these cells. To better delineate how mitochondrial dysfunction induces triglyceride accumulation in preadipocytes, we developed a low-density DNA microarray containing 89 probes, which allows gene expression analysis for major effectors and/or markers of adipogenesis. We thus determined gene expression profiles in 3T3-L1 cells incubated with antimycin A and compared the patterns obtained with differentially expressed genes during the course of in vitro adipogenesis induced by a standard pro-adipogenic cocktail. After an 8-day treatment, a set of 39 genes was found to be differentially expressed in cells treated with antimycin A, among them CCAAT/enhancer-binding protein alpha (C/EBPalpha), C/EBP homologous protein-10 (CHOP-10), mitochondrial glycerol-3-phosphate dehydrogenase (GPDmit), and stearoyl-CoA desaturase 1 (SCD1). We also demonstrate that overexpression of two dominant negative mutants of the cAMP-response element-binding protein CREB (K-CREB and M1-CREB) and siRNA transfection, which disrupt the factor activity and expression, respectively, inhibit antimycin-A-induced triglyceride accumulation. Furthermore, CREB knockdown with siRNA also downregulates the expression of several genes that contain cAMP-response element (CRE) sites in their promoter, among them one that is potentially involved in synthesis of triglycerides such as SCD1. These results highlight a new role for CREB in the control of triglyceride metabolism during the adaptative response of preadipocytes to mitochondrial dysfunction.
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Affiliation(s)
- Sébastien Vankoningsloo
- Laboratory of Biochemistry and Cellular Biology, University of Namur (F.U.N.D.P.), Rue de Bruxelles, 61, 5000 Namur, Belgium
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37
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Liu D, Nagan N, Just WW, Rodemer C, Thai TP, Zoeller RA. Role of dihydroxyacetonephosphate acyltransferase in the biosynthesis of plasmalogens and nonether glycerolipids. J Lipid Res 2005; 46:727-35. [PMID: 15687349 DOI: 10.1194/jlr.m400364-jlr200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The variant CHO-K1 cell line, NRel-4, is unable to synthesize plasmalogens because of a severe reduction in dihydroxyacetonephosphate acyltransferase (DHAPAT) activity (Nagan, N., A. K. Hajra, L. K. Larkins, P. Lazarow, P. E. Purdue, W. B. Rizzo, and R. A. Zoeller. 1998. Isolation of a Chinese hamster fibroblast variant defective in dihydroxyacetonephosphate acyltransferase activity and plasmalogen biosynthesis: use of a novel two-step selection protocol. Biochem. J. 332: 273-279). Northern analysis demonstrated that the loss of this activity was attributable to a severe reduction in mRNA levels for DHAPAT. Transfection of NRel-4 cells with a plasmid bearing the human DHAPAT cDNA recovered DHAPAT activity and plasmalogen biosynthesis. Examination of clonal isolates from the transfected population showed that recovery of as little as 10% of wild-type DHAPAT activity restored plasmalogen levels to 55% of normal, whereas in one isolate, NRel-4.15, which overexpressed DHAPAT activity by 6-fold over wild-type cells, plasmalogen levels were returned only to wild-type values. Although the rate of plasmenylethanolamine biosynthesis was restored in NRel-4.15, the biosynthesis of nonether glycerolipids was either decreased or unaffected, suggesting that peroxisomal DHAPAT does not normally contribute to nonether glycerolipid biosynthesis. These data demonstrate that a defect in the gene that codes for peroxisomal DHAPAT is the primary lesion in the NRel-4 cell line and that the peroxisomal DHAPAT is essential for the biosynthesis of plasmalogens in animal cells.
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Affiliation(s)
- Dailan Liu
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
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38
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Nagura M, Saito M, Iwamori M, Sakakihara Y, Igarashi T. Alterations of fatty acid metabolism and membrane fluidity in peroxisome-defective mutant ZP102 cells. Lipids 2004; 39:43-50. [PMID: 15055234 DOI: 10.1007/s11745-004-1200-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigated lipid composition and FA metabolism in Chinese hamster ovary CHO-K1) cells and Pex5-mutated CHO-K1 (ZP102) cells to clarify the biochemical bases of peroxisome biogenesis disorders (PBD). ZP102 cells have defective peroxisomes and exhibit impairments of peroxisomal beta-oxidation of FA and plasmalogen biosynthesis. In addition, we identified FA metabolic alterations in the synthesis of several classes of lipids in ZP102 cells. The concentration of FFA in ZP102 cells was twice that in CHO-K1 cells, but methyl esters and TAG were decreased in ZP102 cells in comparison with control cells. Also, ceramide monohexoside (CMH) concentration with ZP102 cells was significantly increased compared with the control cells. The FA molecular species, particularly the saturated to unsaturated ratios, of individual lipids also differed between the two cell types. The rate of incorporation of [14C]-labeled saturated acids into sphingomyelin (SM) and CMH in ZP102 cells was higher than that in CHO-K1 cells. Lignoceric acid incorporated into cells was predominantly utilized for the synthesis of SM at 24 h after removal of [14C]lignoceric acid from the culture medium. ZP102 cells showed higher fluorescence anisotropy of 1,3,5-diphenylhexatriene, corresponding to lower membrane mobility than in CHO-K1 cells. In particular, alteration of lipid metabolism by a Pex5 mutation enhanced metabolism of saturated FA and sphingolipids. This may be related to the reduced membrane fluidity of ZP102 cells, which has been implicated in the dysfunction of membrane-linked processes in PBD.
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Affiliation(s)
- Michiaki Nagura
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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39
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Su X, Han X, Yang J, Mancuso DJ, Chen J, Bickel PE, Gross RW. Sequential ordered fatty acid alpha oxidation and Delta9 desaturation are major determinants of lipid storage and utilization in differentiating adipocytes. Biochemistry 2004; 43:5033-44. [PMID: 15109262 DOI: 10.1021/bi035867z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, we exploit the power of global lipidomics to identify the critical role of peroxisomal processing of fatty acids in adipocyte lipid storage and metabolism. Remarkably, 3T3-L1 differentiating adipocytes rapidly acquired the ability to alpha oxidize unbranched fatty acids, which is manifested in the accumulation of odd chain length unbranched fatty acids in all major lipid classes. Moreover, in differentiating adipocytes, unsaturated odd chain length fatty acids in TAG molecular species contained exclusively Delta9 olefinic linkages. Unsaturated fatty acids (e.g., oleic and palmitoleic acids) were not subject to alpha oxidation, resulting in the absence of Delta8 unsaturated odd chain length fatty acids. This highly selective substrate utilization resulted in the obligatory sequential ordering of alpha oxidation prior to Delta9 desaturation. On the basis of these results, a putative type 2 peroxisomal localization sequence was identified at the N-terminus of mouse stearoyl-CoA desaturase I (SCD I) comprised of (30)KVKTVPLHL(38). Kinetic analysis demonstrated that the rate of alpha oxidation of exogenously administered [9,10-(3)H]palmitic acid increased 4-fold during differentiation. Similarly, quantitative PCR demonstrated a 4-fold increase in phytanoyl-CoA alpha hydroxylase (PAHX) and fatty acyl-CoA oxidase (FACO) mRNA levels during differentiation. Collectively, these results underscore the role of peroxisomal fatty acid processing as an important determinant of the metabolic fate of fatty acids in the differentiating adipocyte.
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Affiliation(s)
- Xiong Su
- Department of Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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40
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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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41
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Laudes M, Christodoulides C, Sewter C, Rochford JJ, Considine RV, Sethi JK, Vidal-Puig A, O’Rahilly S. Role of the POZ zinc finger transcription factor FBI-1 in human and murine adipogenesis. J Biol Chem 2003; 279:11711-8. [PMID: 14701838 PMCID: PMC4303998 DOI: 10.1074/jbc.m310240200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Poxvirus zinc finger (POZ) zinc finger domain transcription factors have been shown to play a role in the control of growth arrest and differentiation in several types of mesenchymal cells but not, as yet, adipocytes. We found that a POZ domain protein, factor that binds to inducer of short transcripts-1 (FBI-1), was induced during both murine and human preadipocyte differentiation with maximal expression levels seen at days 2-4. FBI-1 mRNA was expressed in human adipose tissue with the highest levels found in samples from morbidly obese subjects. Murine cell lines constitutively expressing FBI-1 showed evidence for accelerated adipogenesis with earlier induction of markers of differentiation and enhanced lipid accumulation, suggesting that FBI-1 may be an active participant in the differentiation process. Consistent with the properties of this family of proteins in other cell systems, 3T3L1 cells stably overexpressing FBI-1 showed reduced DNA synthesis and reduced expression of cyclin A, cyclin-dependent kinase 2, and p107, proteins known to be involved in the regulation of mitotic clonal expansion. In addition, FBI-1 reduced the transcriptional activity of the cyclin A promoter. Thus, FBI-1, a POZ zinc finger transcription factor, is induced during the early phases of human and murine preadipocyte differentiation where it may contribute to adipogenesis through influencing the switch from cellular proliferation to terminal differentiation.
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Affiliation(s)
| | | | | | | | | | | | | | - Stephen O’Rahilly
- To whom correspondence should be addressed: Dept. of Clinical Biochemistry, University of Cambridge, Addenbrooke’s Hospital, Hills Rd., Box 232, Cambridge CB2 2QR, UK. Tel.: 44-1223-336855; Fax: 44-1223-330598;
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42
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Zimmermann R, Haemmerle G, Wagner EM, Strauss JG, Kratky D, Zechner R. Decreased fatty acid esterification compensates for the reduced lipolytic activity in hormone-sensitive lipase-deficient white adipose tissue. J Lipid Res 2003; 44:2089-99. [PMID: 12923228 DOI: 10.1194/jlr.m300190-jlr200] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been observed previously that hormone-sensitive lipase-deficient (HSL-ko) mice have reduced white adipose tissue (WAT) stores compared to control mice. These findings contradict the expectation that the decreased lipolytic activity in WAT of HSL-ko mice would cause accumulation of triglycerides (TGs) in that tissue. Here we demonstrate that the cellular TG synthesis in HSL-deficient WAT is markedly reduced due to downregulation of the enzymatic activities of glycerophosphate acyltransferase, dihydroxyacetonphosphate acyltransferase, lysophosphatidate acyltransferase, and diacylglycerol acyltransferase. Fatty acid de novo synthesis is also decreased due to reduced cellular glucose uptake, reduced glucose incorporation into adipose tissue lipids, and reduced activities of acetyl:CoA carboxylase and fatty acid synthase. Finally, the activities of phosphoenolpyruvate carboxykinase (PEPCK), acyl:CoA synthetase (ACS), and glucose 6-phosphate dehydrogenase, the enzymes that provide glycerol-3-phosphate, acyl-CoA, and NADPH for TG synthesis, respectively, are decreased in HSL-ko mice. The reduced expression of the peroxisome proliferator-activated receptor gamma (PPAR gamma) target genes PEPCK, ACS, and aP2, as well as reduced mRNA levels of PPAR gamma itself, suggest the involvement of this transcription factor in the downregulation of lipogenesis. Taken together, these results establish that in the absence of HSL, the reduced NEFA production is counteracted by a drastic reduction of NEFA reesterification that provides sufficient quantities of NEFA for release into the circulation. These metabolic adaptations result in decreased fat mass in HSL-ko mice.
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Affiliation(s)
- Robert Zimmermann
- Institute of Molecular Biology, Biochemistry, and Microbiology, University of Graz, Graz, Austria
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Yang J, Han X, Gross RW. Identification of hepatic peroxisomal phospholipase A(2) and characterization of arachidonic acid-containing choline glycerophospholipids in hepatic peroxisomes. FEBS Lett 2003; 546:247-50. [PMID: 12832049 DOI: 10.1016/s0014-5793(03)00581-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recently, a sequence encoding a novel mammalian calcium-independent phospholipase A(2) (iPLA(2)gamma) was identified in the human genome and subsequently cloned and expressed in Sf9 insect cells. Unexpectedly, expression studies in recombinant systems demonstrated the usage of multiple translation initiation codons resulting in different polypeptides. Herein, we demonstrate that hepatic iPLA(2)gamma is localized to rat liver peroxisomes, possesses a molecular mass of 63 kDa and that peroxisomal membranes are highly enriched in arachidonic acid-containing phospholipids. Collectively, these results provide the first demonstration of iPLA(2)gamma in mammalian tissue and suggest the possibility that iPLA(2)gamma can contribute to lipid second messenger generation by hydrolysis of peroxisomal arachidonic acid-containing phospholipids.
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Affiliation(s)
- Jingyue Yang
- Department of Chemistry, Washington University, Campus Box 1134, One Brookings Drive, St Louis, MO 63130, USA
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Affiliation(s)
- N Nagan
- Department of Laboratory Medicine and Pathology, Division of Clinical Biochemistry and Immunology, Mayo Foundation Clinic, Rochester, MN 55905, USA
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