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Peng K, Chen X, Pei K, Wang X, Ma X, Liang C, Dong Q, Liu Z, Han M, Liu G, Yang H, Zheng M, Liu G, Gao M. Lipodystrophic gene Agpat2 deficiency aggravates hyperlipidemia and atherosclerosis in Ldlr -/- mice. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166850. [PMID: 37591406 DOI: 10.1016/j.bbadis.2023.166850] [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: 02/11/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/19/2023]
Abstract
AIMS Dysfunction of adipose tissue increases the risk of cardiovascular disease. It was well established that obesity aggravates atherosclerosis, but the effect of adipose tissue loss on atherosclerosis has been less studied. AGPAT2 is the first causative gene of congenital generalized lipodystrophy (CGL), but the role of AGPAT2 on atherosclerosis has not been reported. Hypertriglyceridemia is one of the clinical manifestations of CGL patients, but it is usually absent in CGL mouse model on a normal diet. This study will investigate the effect of Agpat2 on hyperlipidemia and atherosclerosis. METHODS AND RESULTS In this study, Agpat2 knockout (Agpat2-/-) mice were generated using CRISPR/Cas system, which showed severe loss of adipose tissue and fatty liver, consistent with previous reports. Agpat2-/- mice were then crossed with hypercholesterolemic and atherosclerotic prone LDL receptor knockout (Ldlr-/-) mice to obtain double knockout mouse model (Agpat2-/-Ldlr-/-). Plasma lipid profile, insulin resistance, fatty liver, and atherosclerotic lesions were observed after 12 weeks of the atherogenic high-fat diet (HFD) feeding. We found that compared with Ldlr-/- mice, Agpat2-/-Ldlr-/- mice showed significantly higher plasma total cholesterol and triglycerides after HFD feeding. Agpat2-/-Ldlr-/- mice also developed hyperglycemia and hyperinsulinemia, with increased pancreatic islet area. The liver weight of Agpat2-/-Ldlr-/- mice was about 4 times higher than that of Ldlr-/- mice. The liver lipid deposition was severe and Sirius red staining showed liver fibrosis. In addition, in Agpat2-/-Ldlr-/- mice, the area of atherosclerotic lesions in aortic arch and aortic root was significantly increased. CONCLUSIONS Our results show that Agpat2 deficiency led to more severe hyperlipidemia, liver fibrosis and aggravation of atherosclerosis in Ldlr-/- mice. This study provided additional insights into the role of adipose tissue in hyperlipidemia and atherosclerosis.
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Affiliation(s)
- Kenan Peng
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Laboratory Department of Hebei General Hospital, Shijiazhuang, Hebei 050051, China
| | - Xin Chen
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of General Surgery, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China
| | - Kexin Pei
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China
| | - Xiaowei Wang
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xindi Ma
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Chenxi Liang
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Qianqian Dong
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of Clinical Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, China
| | - Ziwei Liu
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Mei Han
- Department of Biochemistry and Molecular Biology, Key Laboratory of Medical Biotechnology of Hebei Province, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, the University of New South Wales, Sydney, NSW 2052, Australia
| | - Mingqi Zheng
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China.
| | - Gang Liu
- Department of Cardiology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, China.
| | - Mingming Gao
- Laboratory of Lipid Metabolism, Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Key Laboratory of Medical Biotechnology of Hebei Province, Cardiovascular Medical Science Center, Hebei Medical University, Shijiazhuang, Hebei 050017, China.
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Robledo F, González-Hodar L, Tapia P, Figueroa AM, Ezquer F, Cortés V. Spheroids derived from the stromal vascular fraction of adipose tissue self-organize in complex adipose organoids and secrete leptin. Stem Cell Res Ther 2023; 14:70. [PMID: 37024989 PMCID: PMC10080976 DOI: 10.1186/s13287-023-03262-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND Adipose tissue-derived stromal vascular fraction (SVF) harbors multipotent cells with potential therapeutic relevance. We developed a method to form adipose spheroids (AS) from the SVF with complex organoid structure and enhanced leptin secretion upon insulin stimulation. METHODS SVF was generated from the interscapular brown adipose tissue of newborn mice. Immunophenotype and stemness of cultured SVF were determined by flow cytometry and in vitro differentiation, respectively. Spheroids were generated in hanging drops and non-adherent plates and compared by morphometric methods. The adipogenic potential was compared between preadipocyte monolayers and spheroids. Extracellular leptin was quantified by immunoassay. Lipolysis was stimulated with isoprenaline and quantified by colorimetric methods. AS viability and ultrastructure were determined by confocal and transmission electron microscopy analyses. RESULTS Cultured SVF contained Sca1 + CD29 + CD44 + CD11b- CD45- CD90- cells with adipogenic and chondrogenic but no osteogenic potential. Culture on non-adherent plates yielded the highest quantity and biggest size of spheroids. Differentiation of AS for 15 days in a culture medium supplemented with insulin and rosiglitazone resulted in greater Pparg, Plin1, and Lep expression compared to differentiated adipocytes monolayers. AS were viable and maintained leptin secretion even in the absence of adipogenic stimulation. Glycerol release after isoprenaline stimulation was higher in AS compared to adipocytes in monolayers. AS were composed of outer layers of unilocular mature adipocytes and an inner structure composed of preadipocytes, immature adipocytes and an abundant loose extracellular matrix. CONCLUSION Newborn mice adipose SVF can be efficiently differentiated into leptin-secreting AS. Prolonged stimulation with insulin and rosiglitazone allows the formation of structurally complex adipose organoids able to respond to adrenergic lipolytic stimulation.
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Affiliation(s)
- Fermín Robledo
- Department of Nutrition, Diabetes, and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Lila González-Hodar
- Department of Nutrition, Diabetes, and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Tapia
- Department of Nutrition, Diabetes, and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ana-María Figueroa
- Department of Nutrition, Diabetes, and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Fernando Ezquer
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Víctor Cortés
- Department of Nutrition, Diabetes, and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
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3
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Chen R, Liao K, Liao H, Zhang L, Zhao H, Sun J. Screening and functional validation of lipid metabolism-related lncRNA-46546 based on the transcriptome analysis of early embryonic muscle tissue in chicken. Anim Biosci 2023; 36:175-190. [PMID: 35073667 PMCID: PMC9834732 DOI: 10.5713/ab.21.0440] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 01/07/2022] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE The study was conducted to screen differentially expressed long noncoding RNA (lncRNA) in chickens by high-throughput sequencing and explore its mechanism of action on intramuscular fat deposition. METHODS Herein, Rose crown and Cbb broiler chicken embryo breast and leg muscle lncRNA and mRNA expression profiles were constructed by RNA sequencing. A total of 96 and 42 differentially expressed lncRNAs were obtained in Rose crown vs Cobb broiler chicken breast and leg muscle, respectively. lncRNA-ENSGALT00000046546, with high interspecific variability and a potential regulatory role in lipid metabolism, and its predicted downstream target gene 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), were selected for further study on the preadipocytes. RESULTS lncRNA-46546 overexpression in chicken preadipocyte 2 cells significantly increased (p<0.01) the expression levels of AGPAT2 and its downstream genes diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 and those of the fat metabolism-related genes peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, fatty acid synthase, sterol regulatory element-binding transcription factor 1, and fatty acid binding protein 4. The lipid droplet concentration was higher in the overexpression group than in the control cells, and the triglyceride content in cells and medium was also significantly increased (p<0.01). CONCLUSION This study preliminarily concludes that lncRNA-46546 may promote intramuscular fat deposition in chickens, laying a foundation for the study of lncRNAs in chicken early embryonic development and fat deposition.
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Affiliation(s)
- Ruonan Chen
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Kai Liao
- College of Pharmacy, Shihezi University, Shihezi, 832000,
China
| | - Herong Liao
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Li Zhang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China
| | - Haixuan Zhao
- College of Medical, Shihezi University, Shihezi, 832000,
China
| | - Jie Sun
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000,
China,Corresponding Author: Jie Sun, Tel: +86-135-7974-2370, E-mail:
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Tabata K, Prasad V, Paul D, Lee JY, Pham MT, Twu WI, Neufeldt CJ, Cortese M, Cerikan B, Stahl Y, Joecks S, Tran CS, Lüchtenborg C, V'kovski P, Hörmann K, Müller AC, Zitzmann C, Haselmann U, Beneke J, Kaderali L, Erfle H, Thiel V, Lohmann V, Superti-Furga G, Brügger B, Bartenschlager R. Convergent use of phosphatidic acid for hepatitis C virus and SARS-CoV-2 replication organelle formation. Nat Commun 2021; 12:7276. [PMID: 34907161 PMCID: PMC8671429 DOI: 10.1038/s41467-021-27511-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 11/22/2021] [Indexed: 11/09/2022] Open
Abstract
Double membrane vesicles (DMVs) serve as replication organelles of plus-strand RNA viruses such as hepatitis C virus (HCV) and SARS-CoV-2. Viral DMVs are morphologically analogous to DMVs formed during autophagy, but lipids driving their biogenesis are largely unknown. Here we show that production of the lipid phosphatidic acid (PA) by acylglycerolphosphate acyltransferase (AGPAT) 1 and 2 in the ER is important for DMV biogenesis in viral replication and autophagy. Using DMVs in HCV-replicating cells as model, we found that AGPATs are recruited to and critically contribute to HCV and SARS-CoV-2 replication and proper DMV formation. An intracellular PA sensor accumulated at viral DMV formation sites, consistent with elevated levels of PA in fractions of purified DMVs analyzed by lipidomics. Apart from AGPATs, PA is generated by alternative pathways and their pharmacological inhibition also impaired HCV and SARS-CoV-2 replication as well as formation of autophagosome-like DMVs. These data identify PA as host cell lipid involved in proper replication organelle formation by HCV and SARS-CoV-2, two phylogenetically disparate viruses causing very different diseases, i.e. chronic liver disease and COVID-19, respectively. Host-targeting therapy aiming at PA synthesis pathways might be suitable to attenuate replication of these viruses.
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Affiliation(s)
- Keisuke Tabata
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Vibhu Prasad
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - David Paul
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ji-Young Lee
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Minh-Tu Pham
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Woan-Ing Twu
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Christopher J Neufeldt
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Mirko Cortese
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Berati Cerikan
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Yannick Stahl
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Sebastian Joecks
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- LI-COR Biosciences GmbH, Siemensstrasse 25A, Bad Homburg, Germany
| | - Cong Si Tran
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | | | - Philip V'kovski
- Institute of Virology and Immunology IVI, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Katrin Hörmann
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - André C Müller
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Carolin Zitzmann
- Institute of Bioinformatics and Center for Functional Genomics of Microbes, University Medicine Greifswald, Greifswald, Germany
- Los Alamos National Laboratory, Theoretical Biology and Biophysics, Los Alamos, NM, USA
| | - Uta Haselmann
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Jürgen Beneke
- BioQuant, Heidelberg University, Heidelberg, Germany
| | - Lars Kaderali
- Institute of Bioinformatics and Center for Functional Genomics of Microbes, University Medicine Greifswald, Greifswald, Germany
| | - Holger Erfle
- BioQuant, Heidelberg University, Heidelberg, Germany
| | - Volker Thiel
- Institute of Virology and Immunology IVI, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Volker Lohmann
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Britta Brügger
- Biochemistry Center Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
- Division Virus-Associated Carcinogenesis, German Cancer Research Center, Heidelberg, Germany.
- German Center for Infection Research, Heidelberg Partner Site, Heidelberg, Germany.
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5
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González-Hódar L, McDonald JG, Vale G, Thompson BM, Figueroa AM, Tapia PJ, Robledo F, Agarwal AK, Garg A, Horton JD, Cortés V. Decreased caveolae in AGPAT2 lacking adipocytes is independent of changes in cholesterol or sphingolipid levels: A whole cell and plasma membrane lipidomic analysis of adipogenesis. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166167. [PMID: 33989739 DOI: 10.1016/j.bbadis.2021.166167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Adipocytes from lipodystrophic Agpat2-/- mice have impaired adipogenesis and fewer caveolae. Herein, we examined whether these defects are associated with changes in lipid composition or abnormal levels of caveolae-associated proteins. Lipidome changes were quantified in differentiated Agpat2-/- adipocytes to identify lipids with potential adipogenic roles. METHODS Agpat2-/- and wild type brown preadipocytes were differentiated in vitro. Plasma membrane was purified by ultracentrifugation. Number of caveolae and caveolae-associated proteins, as well as sterol, sphingolipid, and phospholipid lipidome were determined across differentiation. RESULTS Differentiated Agpat2-/- adipocytes had decreased caveolae number but conserved insulin signaling. Caveolin-1 and cavin-1 levels were equivalent between Agpat2-/- and wild type adipocytes. No differences in PM cholesterol and sphingolipids abundance were detected between genotypes. Levels of phosphatidylserine at day 10 of differentiation were increased in Agpat2-/- adipocytes. Wild type adipocytes had increased whole cell triglyceride, diacylglycerol, phosphatidylglycerol, phosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, and trihexosyl ceramide, and decreased 24,25-dihydrolanosterol and sitosterol, as a result of adipogenic differentiation. By contrast, adipogenesis did not modify whole cell neutral lipids but increased lysophosphatidylcholine, sphingomyelin, and trihexosyl ceramide levels in Agpat2-/- adipocytes. Unexpectedly, adipogenesis decreased PM levels of main phospholipids in both genotypes. CONCLUSION In Agpat2-/- adipocytes, decreased caveolae is not associated with changes in PM cholesterol nor sphingolipid levels; however, increased PM phosphatidylserine content may be implicated. Abnormal lipid composition is associated with the adipogenic abnormalities of Agpat2 -/- adipocytes but does not prevent insulin signaling.
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Affiliation(s)
- Lila González-Hódar
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Jeffrey G McDonald
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States
| | - Goncalo Vale
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Bonne M Thompson
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Ana-María Figueroa
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Pablo J Tapia
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Fermín Robledo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, TX 75390, United States
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, TX 75390, United States
| | - Jay D Horton
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States.
| | - Víctor Cortés
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile.
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Leung KL, Sanchita S, Pham CT, Davis BA, Okhovat M, Ding X, Dumesic P, Grogan TR, Williams KJ, Morselli M, Ma F, Carbone L, Li X, Pellegrini M, Dumesic DA, Chazenbalk GD. Dynamic changes in chromatin accessibility, altered adipogenic gene expression, and total versus de novo fatty acid synthesis in subcutaneous adipose stem cells of normal-weight polycystic ovary syndrome (PCOS) women during adipogenesis: evidence of cellular programming. Clin Epigenetics 2020; 12:181. [PMID: 33228780 PMCID: PMC7686698 DOI: 10.1186/s13148-020-00970-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022] Open
Abstract
Background Normal-weight polycystic ovary syndrome (PCOS) women exhibit adipose resistance in vivo accompanied by enhanced subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes with accelerated lipid accumulation per cell in vitro. The present study examines chromatin accessibility, RNA expression and fatty acid (FA) synthesis during SC abdominal ASC differentiation into adipocytes in vitro of normal-weight PCOS versus age- and body mass index-matched normoandrogenic ovulatory (control) women to study epigenetic/genetic characteristics as well as functional alterations of PCOS and control ASCs during adipogenesis. Results SC abdominal ASCs from PCOS women versus controls exhibited dynamic chromatin accessibility during adipogenesis, from significantly less chromatin accessibility at day 0 to greater chromatin accessibility by day 12, with enrichment of binding motifs for transcription factors (TFs) of the AP-1 subfamily at days 0, 3, and 12. In PCOS versus control cells, expression of genes governing adipocyte differentiation (PPARγ, CEBPα, AGPAT2) and function (ADIPOQ, FABP4, LPL, PLIN1, SLC2A4) was increased two–sixfold at days 3, 7, and 12, while that involving Wnt signaling (FZD1, SFRP1, and WNT10B) was decreased. Differential gene expression in PCOS cells at these time points involved triacylglycerol synthesis, lipid oxidation, free fatty acid beta-oxidation, and oxidative phosphorylation of the TCA cycle, with TGFB1 as a significant upstream regulator. There was a broad correspondence between increased chromatin accessibility and increased RNA expression of those 12 genes involved in adipocyte differentiation and function, Wnt signaling, as well as genes involved in the triacylglycerol synthesis functional group at day 12 of adipogenesis. Total content and de novo synthesis of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), and oleic (C18:1) acid increased from day 7 to day 12 in all cells, with total content and de novo synthesis of FAs significantly greater in PCOS than controls cells at day 12. Conclusions In normal-weight PCOS women, dynamic chromatin remodeling of SC abdominal ASCs during adipogenesis may enhance adipogenic gene expression as a programmed mechanism to promote greater fat storage.
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Affiliation(s)
- Karen L Leung
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Smriti Sanchita
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Catherine T Pham
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Brett A Davis
- Department of Medicine, Knight Cardiovascular Institute, Oregon Health and Sciences University, Portland, OR, 97239, USA
| | - Mariam Okhovat
- Department of Medicine, Knight Cardiovascular Institute, Oregon Health and Sciences University, Portland, OR, 97239, USA
| | - Xiangming Ding
- Technology Center for Genomics and Bioinformatics, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | | | - Tristan R Grogan
- Department of Medicine Statistics Core, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Kevin J Williams
- UCLA Lipidomics Lab, Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Marco Morselli
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Feiyang Ma
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Lucia Carbone
- Department of Medicine, Knight Cardiovascular Institute, Oregon Health and Sciences University, Portland, OR, 97239, USA.,Department of Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, OR, 97239, USA.,Department of Medical Information and Clinical Epidemiology, Oregon Health and Sciences University, Portland, OR, 97239, USA.,Division of Genetics, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Xinmin Li
- Technology Center for Genomics and Bioinformatics, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Daniel A Dumesic
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Gregorio D Chazenbalk
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.
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7
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Tapia PJ, Figueroa AM, Eisner V, González-Hódar L, Robledo F, Agarwal AK, Garg A, Cortés V. Absence of AGPAT2 impairs brown adipogenesis, increases IFN stimulated gene expression and alters mitochondrial morphology. Metabolism 2020; 111:154341. [PMID: 32810486 DOI: 10.1016/j.metabol.2020.154341] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/29/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Biallelic loss of function variants in AGPAT2, encoding 1-acylglycerol-3-phosphate O-acyltransferase 2, cause congenital generalized lipodystrophy type 1, a disease characterized by near total loss of white adipose tissue and metabolic complications. Agpat2 deficient (Agpat2-/-) mice completely lacks both white and interscapular brown adipose tissue (iBAT). The objective of the present study was to characterize the effects of AGPAT2 deficiency in brown adipocyte differentiation. METHODS Preadipocytes obtained from newborn (P0.5) Agpat2-/- and wild type mice iBAT were differentiated into brown adipocytes, compared by RNA microarray, RT-qPCR, High-Content Screening (HCS), western blotting and electron microscopy. RESULTS 1) Differentiated Agpat2-/- brown adipocytes have fewer lipid-laden cells and lower abundance of Pparγ, Pparα, C/ebpα and Pgc1α, both at the mRNA and protein levels, compared those to wild type cells. Prmd16 levels were equivalent in both, Agpat2-/- and wild type, while Ucp1 was only induced in wild type cells, 2) These differences were not due to lower abundance of preadipocytes, 3) Differentiated Agpat2-/- brown adipocytes are enriched in the mRNA abundance of genes participating in interferon (IFN) type I response, whereas genes involved in mitochondrial homeostasis were decreased, 4) Mitochondria in differentiated Agpat2-/- brown adipocytes had altered morphology and lower mass and contacting sites with lipid droplets concomitant with lower levels of Mitofusin 2 and Perlipin 5. CONCLUSION AGPAT2 is necessary for normal brown adipose differentiation. Its absence results in a lower proportion of lipid-laden cells, increased expression of interferon-stimulated genes (ISGs) and alterations in mitochondrial morphology, mass and fewer mitochondria to lipid droplets contacting sites in differentiated brown adipocytes.
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Affiliation(s)
- Pablo J Tapia
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Ana-María Figueroa
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Verónica Eisner
- Department of Cellular and Molecular Biology, School of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile.
| | - Lila González-Hódar
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Fermín Robledo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States of America.
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States of America.
| | - Víctor Cortés
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
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8
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Hoa Chung L, Qi Y. Lipodystrophy - A Rare Condition with Serious Metabolic Abnormalities. Rare Dis 2020. [DOI: 10.5772/intechopen.88667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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9
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Wang F, Chen S, Ren L, Wang Y, Li Z, Song T, Zhang H, Yang Q. The Effect of Silibinin on Protein Expression Profile in White Adipose Tissue of Obese Mice. Front Pharmacol 2020; 11:55. [PMID: 32184719 PMCID: PMC7059093 DOI: 10.3389/fphar.2020.00055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/20/2020] [Indexed: 01/07/2023] Open
Abstract
Objective To investigate the effect of silibinin on the protein expression profile of white adipose tissue (WAT) in obese mice by using Tandem Mass Tag (TMT) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods According to experimental requirements, 36 C57BL/6JC mice were randomly divided into normal diet group (WC group), high fat diet group (WF group), and high fat diet + silibinin group (WS group). WS group was intragastrically administered with 54 mg/kg body weight of silibinin, and the WC group and the WF group were intragastrically administered with equal volume of normal saline. Serum samples were collected to detect fasting blood glucose and blood lipids. IPGTT was used to measure the blood glucose value at each time point and calculate the area under the glucose curve. TMT combined with LC-MS/MS were used to study the expression of WAT, and its cellular processes, biological processes, corresponding molecular functions, and related network molecular mechanisms were analyzed by bioinformatics. Finally, RT-PCR and LC-MS/MS were used to detect the mRNA and protein expressions of FABP5, Plin4, GPD1, and AGPAT2, respectively. Results Although silibinin did not reduce the mice's weight, it did improve glucose metabolism. In addition, silibinin decreased the concentration of TC, TG, and LDL-C and increased the concentration of HDL-C in the serum of mice. In the WF/WS group, 182 differentially expressed proteins were up-regulated and 159 were down-regulated. While in the WS/WF group, 362 differentially expressed proteins were up-regulated and 176 were down-regulated. Further analysis found that these differential proteins are mainly distributed in the peroxisome proliferation-activated receptor (PPAR), lipolysis of fat cells, metabolism of glycerides, oxidative phosphorylation, and other signaling pathways, and participate in cell processes and lipid metabolism through catalysis and integration functions. Specifically, silibinin reduced the expression of several key factors such as FABP5, Plin4, GPD1, and AGPTA2. Conclusion High fat diet (HFD) can increase the expression of lipid synthesis and transport-related proteins and reduce mitochondrial related proteins, thereby increasing lipid synthesis, reducing energy consumption, and improving lipid metabolism in vivo. Silibinin can reduce lipid synthesis, increase energy consumption, and improve lipid metabolism in mice in vivo.
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Affiliation(s)
- Fei Wang
- Graduate School of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - Shuchun Chen
- Graduate School of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - Luping Ren
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - Yichao Wang
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China.,North China University of Science and Technology, Tangshan, China
| | - Zelin Li
- Graduate School of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - Tiantian Song
- Graduate School of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - He Zhang
- Graduate School of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China
| | - Qiwen Yang
- Department of Endocrinology, Hebei General Hospital, Shijiazhuang, China.,Hebei North University, Zhangjiakou, China
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Foss-Freitas MC, Akinci B, Luo Y, Stratton A, Oral EA. Diagnostic strategies and clinical management of lipodystrophy. Expert Rev Endocrinol Metab 2020; 15:95-114. [PMID: 32368944 DOI: 10.1080/17446651.2020.1735360] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/24/2020] [Indexed: 12/16/2022]
Abstract
Introduction: Lipodystrophy is a heterogeneous group of rare diseases characterized by various degrees of fat loss which leads to serious morbidity due to metabolic abnormalities associated with insulin resistance and subtype-specific clinical features associated with underlying molecular etiology.Areas covered: This article aims to help physicians address challenges in diagnosing and managing lipodystrophy. We systematically reviewed the literature on PubMed and Google Scholar databases to summarize the current knowledge in lipodystrophy management.Expert opinion: Adipose tissue is a highly active endocrine organ that regulates metabolic homeostasis in the human body through a comprehensive communication network with other organ systems such as the central nervous system, liver, digestive system, and the immune system. The adipose tissue is capable of producing and secreting numerous factors with important endocrine functions such as leptin that regulates energy homeostasis. Recent developments in the field have helped to solve some of the mysteries behind lipodystrophy that allowed us to get a better understanding of adipocyte function and differentiation. From a clinical standpoint, physicians who suspect lipodystrophy should distinguish the disease from several others that may present with similar clinical features. It is also important for physicians to carefully interpret clinical features, laboratory, and imaging results before moving to more sophisticated tests and making decisions about therapy.
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Affiliation(s)
- Maria C Foss-Freitas
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Ribeirao Preto Medical School, Sao Paulo University, Ribeirao Preto, Brazil
| | - Baris Akinci
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Yingying Luo
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China
| | | | - Elif A Oral
- Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
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Bruder-Nascimento T, Kress TC, Belin de Chantemele EJ. Recent advances in understanding lipodystrophy: a focus on lipodystrophy-associated cardiovascular disease and potential effects of leptin therapy on cardiovascular function. F1000Res 2019; 8:F1000 Faculty Rev-1756. [PMID: 31656583 PMCID: PMC6798323 DOI: 10.12688/f1000research.20150.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/08/2019] [Indexed: 01/09/2023] Open
Abstract
Lipodystrophy is a disease characterized by a partial or total absence of adipose tissue leading to severe metabolic derangements including marked insulin resistance, type 2 diabetes, hypertriglyceridemia, and steatohepatitis. Lipodystrophy is also a source of major cardiovascular disorders which, in addition to hepatic failure and infection, contribute to a significant reduction in life expectancy. Metreleptin, the synthetic analog of the adipocyte-derived hormone leptin and current therapy of choice for patients with lipodystrophy, successfully improves metabolic function. However, while leptin has been associated with hypertension, vascular diseases, and inflammation in the context of obesity, it remains unknown whether its daily administration could further impair cardiovascular function in patients with lipodystrophy. The goal of this short review is to describe the cardiovascular phenotype of patients with lipodystrophy, speculate on the etiology of the disorders, and discuss how the use of murine models of lipodystrophy could be beneficial to address the question of the contribution of leptin to lipodystrophy-associated cardiovascular disease.
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Affiliation(s)
- Thiago Bruder-Nascimento
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Pediatrics, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Taylor C. Kress
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Eric J. Belin de Chantemele
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Medicine, Section of Cardiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
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12
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Abstract
Lipodystrophies are the result of a range of inherited and acquired causes, but all are characterized by perturbations in white adipose tissue function and, in many instances, its mass or distribution. Though patients are often nonobese, they typically manifest a severe form of the metabolic syndrome, highlighting the importance of white fat in the "safe" storage of surplus energy. Understanding the molecular pathophysiology of congenital lipodystrophies has yielded useful insights into the biology of adipocytes and informed therapeutic strategies. More recently, genome-wide association studies focused on insulin resistance have linked common variants to genes implicated in adipose biology and suggested that subtle forms of lipodystrophy contribute to cardiometabolic disease risk at a population level. These observations underpin the use of aligned treatment strategies in insulin-resistant obese and lipodystrophic patients, the major goal being to alleviate the energetic burden on adipose tissue.
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13
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Akinci B, Meral R, Oral EA. Phenotypic and Genetic Characteristics of Lipodystrophy: Pathophysiology, Metabolic Abnormalities, and Comorbidities. Curr Diab Rep 2018; 18:143. [PMID: 30406415 DOI: 10.1007/s11892-018-1099-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW This article focuses on recent progress in understanding the genetics of lipodystrophy syndromes, the pathophysiology of severe metabolic abnormalities caused by these syndromes, and causes of severe morbidity and a possible signal of increased mortality associated with lipodystrophy. An updated classification scheme is also presented. RECENT FINDINGS Lipodystrophy encompasses a group of heterogeneous rare diseases characterized by generalized or partial lack of adipose tissue and associated metabolic abnormalities including altered lipid metabolism and insulin resistance. Recent advances in the field have led to the discovery of new genes associated with lipodystrophy and have also improved our understanding of adipose biology, including differentiation, lipid droplet assembly, and metabolism. Several registries have documented the natural history of the disease and the serious comorbidities that patients with lipodystrophy face. There is also evolving evidence for increased mortality rates associated with lipodystrophy. Lipodystrophy syndromes represent a challenging cluster of diseases that lead to severe insulin resistance, a myriad of metabolic abnormalities, and serious morbidity. The understanding of these syndromes is evolving in parallel with the identification of novel disease-causing mechanisms.
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Affiliation(s)
- Baris Akinci
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA
- Division of Endocrinology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Rasimcan Meral
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA
| | - Elif Arioglu Oral
- Brehm Center for Diabetes Research, Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, 1000 Wall Street, Room 5313, Ann Arbor, MI, 48105, USA.
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Bradley RM, Bloemberg D, Aristizabal Henao JJ, Hashemi A, Mitchell AS, Fajardo VA, Bellissimo C, Mardian EB, Bombardier E, Paré MF, Moes KA, Stark KD, Tupling AR, Quadrilatero J, Duncan RE. Lpaatδ/Agpat4 deficiency impairs maximal force contractility in soleus and alters fibre type in extensor digitorum longus muscle. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:700-711. [PMID: 29627383 DOI: 10.1016/j.bbalip.2018.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/13/2018] [Accepted: 04/04/2018] [Indexed: 01/09/2023]
Abstract
Lysophosphatidic acid acyltransferase (LPAAT) δ/acylglycerophosphate acyltransferase 4 is a mitochondrial enzyme and one of five homologues that catalyze the acyl-CoA-dependent synthesis of phosphatidic acid (PA) from lysophosphatidic acid. We studied skeletal muscle LPAATδ and found highest levels in soleus, a red oxidative fibre-type that is rich in mitochondria, and lower levels in extensor digitorum longus (EDL) (white glycolytic) and gastrocnemius (mixed fibre-type). Using Lpaatδ-deficient mice, we found no change in soleus or EDL mass, or in treadmill time-to-exhaustion compared to wildtype littermates. There was, however, a significant reduction in the proportion of type I and type IIA fibres in EDL but, surprisingly, not soleus, where these fibre-types predominate. Also unexpectedly, there was no impairment in force generation by EDL, but a significant reduction by soleus. Oxidative phosphorylation and activity of complexes I, I + II, III, and IV in soleus mitochondria was unchanged and therefore could not explain this effect. However, pyruvate dehydrogenase activity was significantly reduced in Lpaatδ-/- soleus and EDL. Analysis of cellular lipids indicated no difference in soleus triacylglycerol, but specific elevations in soleus PA and phosphatidylethanolamine levels, likely due to a compensatory upregulation of Lpaatβ and Lpaatε in Lpaatδ-/- mice. An anabolic effect for PA as an activator of skeletal muscle mTOR has been reported, but we found no change in serine 2448 phosphorylation, indicating reduced soleus force generation is unlikely due to the loss of mTOR activation by a specific pool of LPAATδ-derived PA. Our results identify an important role for LPAATδ in soleus and EDL.
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Affiliation(s)
- Ryan M Bradley
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Darin Bloemberg
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Juan J Aristizabal Henao
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Ashkan Hashemi
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Andrew S Mitchell
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Val A Fajardo
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Catherine Bellissimo
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Emily B Mardian
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Eric Bombardier
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Marie-France Paré
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Katherine A Moes
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Ken D Stark
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - A Russell Tupling
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Joe Quadrilatero
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada
| | - Robin E Duncan
- University of Waterloo, Department of Kinesiology, Faculty of Applied Health Sciences, 200 University Avenue West, BMH 1110, Waterloo, Ontario N2L 3G1, Canada.
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15
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Bradley RM, Duncan RE. The lysophosphatidic acid acyltransferases (acylglycerophosphate acyltransferases) family: one reaction, five enzymes, many roles. Curr Opin Lipidol 2018; 29:110-115. [PMID: 29373329 DOI: 10.1097/mol.0000000000000492] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE OF REVIEW Lysophosphatidic acid acyltransferases (LPAATs)/acylglycerophosphate acyltransferases (AGPATs) are a homologous group of enzymes that all catalyze the de novo formation of phosphatidic acid from lysophosphatidic acid (LPA) and a fatty acyl-CoA. This review seeks to resolve the apparent redundancy of LPAATs through examination of recent literature. RECENT FINDINGS Recent molecular studies suggest that individual LPAAT homologues produce functionally distinct pools of phosphatidic acid, whereas gene ablation studies demonstrate unique roles despite a similar biochemical function. Loss of the individual enzymes not only causes diverse effects on down-stream lipid metabolism, which can vary even for a single enzyme from one tissue to the next, but also results in a wide array of physiological consequences, ranging from cognitive impairment, to lipodystrophy, to embryonic lethality. SUMMARY LPAATs are critical mediators of cell membrane phospholipid synthesis, regulating the production of specific down-stream glycerophospholipid species through generation of distinct pools of phosphatidic acid that feed into dedicated biosynthetic pathways. Loss of any specific LPAAT can lead to alterations in cellular and organellar membrane phospholipid composition that can vary for a single enzyme in different tissues, with unique pathophysiological implications.
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Affiliation(s)
- Ryan M Bradley
- Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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Transcriptome Analysis Reveals Increases in Visceral Lipogenesis and Storage and Activation of the Antigen Processing and Presentation Pathway during the Mouth-Opening Stage in Zebrafish Larvae. Int J Mol Sci 2017; 18:ijms18081634. [PMID: 28758957 PMCID: PMC5578024 DOI: 10.3390/ijms18081634] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/20/2017] [Accepted: 07/21/2017] [Indexed: 12/11/2022] Open
Abstract
The larval phase of the fish life cycle has the highest mortality, particularly during the transition from endogenous to exogenous feeding. However, the transcriptional events underlying these processes have not been fully characterized. To understand the molecular mechanisms underlying mouth-opening acclimation, RNA-seq was used to investigate the transcriptional profiles of the endogenous feeding, mixed feeding and exogenous feeding stages of zebrafish larvae. Differential expression analysis showed 2172 up-regulated and 2313 down-regulated genes during this stage. Genes associated with the assimilation of exogenous nutrients such as the arachidonic acid metabolism, linoleic acid metabolism, fat digestion and absorption, and lipogenesis were activated significantly, whereas dissimilation including the cell cycle, homologous recombination, and fatty acid metabolism were inhibited, indicating a physiological switch for energy storage occurred during the mouth-opening stage. Moreover, the immune recognition involved in the antigen processing and presentation pathway was activated and nutritional supply seemed to be required in this event confirmed by qPCR. These results suggested the energy utilization during the mouth-opening stage is more tended to be reserved or used for some important demands, such as activity regulation, immune defense, and lipid deposition, instead of rapid growth. The findings of this study are important for understanding the physiological switches during the mouth-opening stage.
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