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Köberlin MS, Fan Y, Liu C, Chung M, Pinto AFM, Jackson PK, Saghatelian A, Meyer T. A fast-acting lipid checkpoint in G1 prevents mitotic defects. Nat Commun 2024; 15:2441. [PMID: 38499565 PMCID: PMC10948896 DOI: 10.1038/s41467-024-46696-9] [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: 07/24/2023] [Accepted: 03/06/2024] [Indexed: 03/20/2024] Open
Abstract
Lipid synthesis increases during the cell cycle to ensure sufficient membrane mass, but how insufficient synthesis restricts cell-cycle entry is not understood. Here, we identify a lipid checkpoint in G1 phase of the mammalian cell cycle by using live single-cell imaging, lipidome, and transcriptome analysis of a non-transformed cell. We show that synthesis of fatty acids in G1 not only increases lipid mass but extensively shifts the lipid composition to unsaturated phospholipids and neutral lipids. Strikingly, acute lowering of lipid synthesis rapidly activates the PERK/ATF4 endoplasmic reticulum (ER) stress pathway that blocks cell-cycle entry by increasing p21 levels, decreasing Cyclin D levels, and suppressing Retinoblastoma protein phosphorylation. Together, our study identifies a rapid anticipatory ER lipid checkpoint in G1 that prevents cells from starting the cell cycle as long as lipid synthesis is low, thereby preventing mitotic defects, which are triggered by low lipid synthesis much later in mitosis.
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Affiliation(s)
- Marielle S Köberlin
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Yilin Fan
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Chad Liu
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94111, USA
| | - Mingyu Chung
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Antonio F M Pinto
- Clayton Foundation Laboratories for Peptide Biology and Mass Spectrometry Core, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology and Mass Spectrometry Core, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY, 10065, USA.
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2
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Schempp R, Eilts J, Schöl M, Grijalva Yépez MF, Fekete A, Wigger D, Schumacher F, Kleuser B, van Ham M, Jänsch L, Sauer M, Avota E. The Role of Neutral Sphingomyelinase-2 (NSM2) in the Control of Neutral Lipid Storage in T Cells. Int J Mol Sci 2024; 25:3247. [PMID: 38542220 PMCID: PMC10970209 DOI: 10.3390/ijms25063247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/25/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024] Open
Abstract
The accumulation of lipid droplets (LDs) and ceramides (Cer) is linked to non-alcoholic fatty liver disease (NAFLD), regularly co-existing with type 2 diabetes and decreased immune function. Chronic inflammation and increased disease severity in viral infections are the hallmarks of the obesity-related immunopathology. The upregulation of neutral sphingomyelinase-2 (NSM2) has shown to be associated with the pathology of obesity in tissues. Nevertheless, the role of sphingolipids and specifically of NSM2 in the regulation of immune cell response to a fatty acid (FA) rich environment is poorly studied. Here, we identified the presence of the LD marker protein perilipin 3 (PLIN3) in the intracellular nano-environment of NSM2 using the ascorbate peroxidase APEX2-catalyzed proximity-dependent biotin labeling method. In line with this, super-resolution structured illumination microscopy (SIM) shows NSM2 and PLIN3 co-localization in LD organelles in the presence of increased extracellular concentrations of oleic acid (OA). Furthermore, the association of enzymatically active NSM2 with isolated LDs correlates with increased Cer levels in these lipid storage organelles. NSM2 enzymatic activity is not required for NSM2 association with LDs, but negatively affects the LD numbers and cellular accumulation of long-chain unsaturated triacylglycerol (TAG) species. Concurrently, NSM2 expression promotes mitochondrial respiration and fatty acid oxidation (FAO) in response to increased OA levels, thereby shifting cells to a high energetic state. Importantly, endogenous NSM2 activity is crucial for primary human CD4+ T cell survival and proliferation in a FA rich environment. To conclude, our study shows a novel NSM2 intracellular localization to LDs and the role of enzymatically active NSM2 in metabolic response to enhanced FA concentrations in T cells.
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Affiliation(s)
- Rebekka Schempp
- Institute for Virology and Immunobiology, University of Wuerzburg, 97078 Wuerzburg, Germany; (R.S.); (M.S.); (M.F.G.Y.)
| | - Janna Eilts
- Department of Biotechnology and Biophysics, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany; (J.E.); (M.S.)
| | - Marie Schöl
- Institute for Virology and Immunobiology, University of Wuerzburg, 97078 Wuerzburg, Germany; (R.S.); (M.S.); (M.F.G.Y.)
| | - Maria Fernanda Grijalva Yépez
- Institute for Virology and Immunobiology, University of Wuerzburg, 97078 Wuerzburg, Germany; (R.S.); (M.S.); (M.F.G.Y.)
| | - Agnes Fekete
- Pharmaceutical Biology, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, 97082 Wuerzburg, Germany;
| | - Dominik Wigger
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Freie Universitaet Berlin, 14195 Berlin, Germany; (D.W.); (F.S.); (B.K.)
| | - Fabian Schumacher
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Freie Universitaet Berlin, 14195 Berlin, Germany; (D.W.); (F.S.); (B.K.)
| | - Burkhard Kleuser
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Freie Universitaet Berlin, 14195 Berlin, Germany; (D.W.); (F.S.); (B.K.)
| | - Marco van Ham
- Cellular Proteome Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (M.v.H.); (L.J.)
| | - Lothar Jänsch
- Cellular Proteome Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (M.v.H.); (L.J.)
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany; (J.E.); (M.S.)
| | - Elita Avota
- Institute for Virology and Immunobiology, University of Wuerzburg, 97078 Wuerzburg, Germany; (R.S.); (M.S.); (M.F.G.Y.)
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3
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Hernandez-Corbacho M, Canals D. Drug Targeting of Acyltransferases in the Triacylglyceride and 1-O-AcylCeramide Biosynthetic Pathways. Mol Pharmacol 2024; 105:166-178. [PMID: 38164582 DOI: 10.1124/molpharm.123.000763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/09/2023] [Accepted: 11/20/2023] [Indexed: 01/03/2024] Open
Abstract
Acyltransferase enzymes (EC 2.3.) are a large group of enzymes that transfer acyl groups to a variety of substrates. This review focuses on fatty acyltransferases involved in the biosynthetic pathways of glycerolipids and sphingolipids and how these enzymes have been pharmacologically targeted in their biologic context. Glycerolipids and sphingolipids, commonly treated independently in their regulation and biologic functions, are put together to emphasize the parallelism in their metabolism and bioactive roles. Furthermore, a newly considered signaling molecule, 1-O-acylceramide, resulting from the acylation of ceramide by DGAT2 enzyme, is discussed. Finally, the implications of DGAT2 as a putative ceramide acyltransferase (CAT) enzyme, with a putative dual role in TAG and 1-O-acylceramide generation, are explored. SIGNIFICANCE STATEMENT: This manuscript reviews the current status of drug development in lipid acyltransferases. These are current targets in metabolic syndrome and other diseases, including cancer. A novel function for a member in this group of lipids has been recently reported in cancer cells. The responsible enzyme and biological implications of this added member are discussed.
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Affiliation(s)
| | - Daniel Canals
- Department of Medicine, Stony Brook University, Stony Brook, New York
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Jusović M, Starič P, Jarc Jovičić E, Petan T. The Combined Inhibition of Autophagy and Diacylglycerol Acyltransferase-Mediated Lipid Droplet Biogenesis Induces Cancer Cell Death during Acute Amino Acid Starvation. Cancers (Basel) 2023; 15:4857. [PMID: 37835551 PMCID: PMC10571868 DOI: 10.3390/cancers15194857] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
Lipid droplets (LDs) are dynamic organelles involved in the management of fatty acid trafficking and metabolism. Recent studies suggest that autophagy and LDs serve complementary roles in the protection against nutrient stress, but the autophagy-LD interplay in cancer cells is not well understood. Here, we examined the relationship between autophagy and LDs in starving HeLa cervical cancer- and MDA-MB-231 breast cancer cells. We found that acute amino acid depletion induces autophagy and promotes diacylglycerol acyltransferase 1 (DGAT1)-mediated LD accumulation in HeLa cells. Inhibition of autophagy via late-stage autophagy inhibitors, or by knocking down autophagy-related 5 (ATG5), reduced LD accumulation in amino acid-starved cancer cells, suggesting that autophagy contributes to LD biogenesis. On the contrary, knockdown of adipose triglyceride lipase (ATGL) increased LD accumulation, suggesting that LD breakdown is mediated by lipolysis under these conditions. Concurrent inhibition of autophagy by silencing ATG5 and of LD biogenesis using DGAT inhibitors was effective in killing starving HeLa cells, whereas cell survival was not compromised by suppression of ATGL-mediated lipolysis. Autophagy-dependent LD biogenesis was also observed in the aggressive triple-negative MDA-MB-231 breast cancer cells deprived of amino acids, but these cells were not sensitized to starvation by the combined inhibition of LD biogenesis and autophagy. These findings reveal that while targeting autophagy-driven and DGAT-mediated LD biogenesis reduces the resilience of HeLa cervical cancer cells to amino acid deprivation, this strategy may not be successful in other cancer cell types.
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Affiliation(s)
- Maida Jusović
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia; (M.J.); (P.S.); (E.J.J.)
- Jožef Stefan International Postgraduate School, SI-1000 Ljubljana, Slovenia
| | - Pia Starič
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia; (M.J.); (P.S.); (E.J.J.)
| | - Eva Jarc Jovičić
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia; (M.J.); (P.S.); (E.J.J.)
- Jožef Stefan International Postgraduate School, SI-1000 Ljubljana, Slovenia
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia; (M.J.); (P.S.); (E.J.J.)
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5
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Jovičić EJ, Janež AP, Eichmann TO, Koren Š, Brglez V, Jordan PM, Gerstmeier J, Lainšček D, Golob-Urbanc A, Jerala R, Lambeau G, Werz O, Zimmermann R, Petan T. Lipid droplets control mitogenic lipid mediator production in human cancer cells. Mol Metab 2023; 76:101791. [PMID: 37586657 PMCID: PMC10470291 DOI: 10.1016/j.molmet.2023.101791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/29/2023] [Accepted: 08/08/2023] [Indexed: 08/18/2023] Open
Abstract
OBJECTIVES Polyunsaturated fatty acids (PUFAs) are structural components of membrane phospholipids and precursors of oxygenated lipid mediators with diverse functions, including the control of cell growth, inflammation and tumourigenesis. However, the molecular pathways that control the availability of PUFAs for lipid mediator production are not well understood. Here, we investigated the crosstalk of three pathways in the provision of PUFAs for lipid mediator production: (i) secreted group X phospholipase A2 (GX sPLA2) and (ii) cytosolic group IVA PLA2 (cPLA2α), both mobilizing PUFAs from membrane phospholipids, and (iii) adipose triglyceride lipase (ATGL), which mediates the degradation of triacylglycerols (TAGs) stored in cytosolic lipid droplets (LDs). METHODS We combined lipidomic and functional analyses in cancer cell line models to dissect the trafficking of PUFAs between membrane phospholipids and LDs and determine the role of these pathways in lipid mediator production, cancer cell proliferation and tumour growth in vivo. RESULTS We demonstrate that lipid mediator production strongly depends on TAG turnover. GX sPLA2 directs ω-3 and ω-6 PUFAs from membrane phospholipids into TAG stores, whereas ATGL is required for their entry into lipid mediator biosynthetic pathways. ATGL controls the release of PUFAs from LD stores and their conversion into cyclooxygenase- and lipoxygenase-derived lipid mediators under conditions of nutrient sufficiency and during serum starvation. In starving cells, ATGL also promotes the incorporation of LD-derived PUFAs into phospholipids, representing substrates for cPLA2α. Furthermore, we demonstrate that the built-up of TAG stores by acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is required for the production of mitogenic lipid signals that promote cancer cell proliferation and tumour growth. CONCLUSION This study shifts the paradigm of PLA2-driven lipid mediator signalling and identifies LDs as central lipid mediator production hubs. Targeting DGAT1-mediated LD biogenesis is a promising strategy to restrict lipid mediator production and tumour growth.
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Affiliation(s)
- Eva Jarc Jovičić
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Anja Pucer Janež
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; Center for Explorative Lipidomics, BioTechMed-Graz, Graz, Austria
| | - Špela Koren
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Vesna Brglez
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Paul M Jordan
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Jana Gerstmeier
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Duško Lainšček
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia; EN-FIST, Centre of Excellence, Ljubljana, Slovenia
| | - Anja Golob-Urbanc
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Roman Jerala
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia; EN-FIST, Centre of Excellence, Ljubljana, Slovenia
| | - Gérard Lambeau
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France
| | - Oliver Werz
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; BioTechMed-Graz, University of Graz, Graz, Austria
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia.
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6
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Vanni E, Lindner K, Gavin AC, Montessuit C. Differential intracellular management of fatty acids impacts on metabolic stress-stimulated glucose uptake in cardiomyocytes. Sci Rep 2023; 13:14805. [PMID: 37684349 PMCID: PMC10491837 DOI: 10.1038/s41598-023-42072-7] [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: 03/03/2023] [Accepted: 09/05/2023] [Indexed: 09/10/2023] Open
Abstract
Stimulation of glucose uptake in response to ischemic metabolic stress is important for cardiomyocyte function and survival. Chronic exposure of cardiomyocytes to fatty acids (FA) impairs the stimulation of glucose uptake, whereas induction of lipid droplets (LD) is associated with preserved glucose uptake. However, the mechanisms by which LD induction prevents glucose uptake impairment remain elusive. We induced LD with either tetradecanoyl phorbol acetate (TPA) or 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR). Triacylglycerol biosynthesis enzymes were inhibited in cardiomyocytes exposed to FA ± LD inducers, either upstream (glycerol-3-phosphate acyltransferases; GPAT) or downstream (diacylglycerol acyltransferases; DGAT) of the diacylglycerol step. Although both inhibitions reduced LD formation in cardiomyocytes treated with FA and LD inducers, only DGAT inhibition impaired metabolic stress-stimulated glucose uptake. DGAT inhibition in FA plus TPA-treated cardiomyocytes reduced triacylglycerol but not diacylglycerol content, thus increasing the diacylglycerol/triacylglycerol ratio. In cardiomyocytes exposed to FA alone, GPAT inhibition reduced diacylglycerol but not triacylglycerol, thus decreasing the diacylglycerol/triacylglycerol ratio, prevented PKCδ activation and improved metabolic stress-stimulated glucose uptake. Changes in AMP-activated Protein Kinase activity failed to explain variations in metabolic stress-stimulated glucose uptake. Thus, LD formation regulates metabolic stress-stimulated glucose uptake in a manner best reflected by the diacylglycerol/triacylglycerol ratio.
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Affiliation(s)
- Ettore Vanni
- Department of Pathology and Immunology, University of Geneva School of Medicine, Geneva, Switzerland
| | - Karina Lindner
- Department of Cell Physiology and Metabolism, University of Geneva School of Medicine, Geneva, Switzerland
| | - Anne-Claude Gavin
- Department of Cell Physiology and Metabolism, University of Geneva School of Medicine, Geneva, Switzerland
| | - Christophe Montessuit
- Department of Pathology and Immunology, University of Geneva School of Medicine, Geneva, Switzerland.
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7
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Yuan Y, Olawode EO, Tumey LN, Lu F. Visualizing drug-induced lipid accumulation in lysosomes of live cancer cells with stimulated Raman imaging. BIOMEDICAL OPTICS EXPRESS 2023; 14:2551-2564. [PMID: 37342714 PMCID: PMC10278636 DOI: 10.1364/boe.487527] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/31/2023] [Accepted: 04/04/2023] [Indexed: 06/23/2023]
Abstract
The low pH of the lysosomal compartment often results in sequestration of chemotherapeutic agents that contain positively charged basic functional groups, leading to anti-cancer drug resistance. To visualize drug localization in lysosomes and its influence on lysosomal functions, we synthesize a group of drug-like compounds that contain both a basic functional group and a bisarylbutadiyne (BADY) group as a Raman probe. With quantitative stimulated Raman scattering (SRS) imaging, we validate that the synthesized lysosomotropic (LT) drug analogs show high lysosomal affinity, which can also serve as a photostable lysosome tracker. We find that long-term retention of the LT compounds in lysosomes leads to the increased amount and colocalization of both lipid droplets (LDs) and lysosomes in SKOV3 cells. With hyperspectral SRS imaging, further studies find that the LDs stuck in lysosomes are more saturated than the LDs staying out of the lysosomes, indicating impaired lysosomal lipid metabolism by the LT compounds. These results demonstrate that SRS imaging of the alkyne-based probes is a promising approach to characterizing the lysosomal sequestration of drugs and its influence on cell functions.
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Affiliation(s)
- Yuhao Yuan
- Department of Biomedical Engineering, Thomas J. Watson College of Engineering and Applied Science, Binghamton University, State University of New York, Binghamton, NY 13902, USA
- Current Address: Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA
| | - Emmanuel O. Olawode
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, USA
- Current Address: College of Pharmacy, Larkin University, Miami, FL 33169, USA
| | - L. Nathan Tumey
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, USA
| | - Fake Lu
- Department of Biomedical Engineering, Thomas J. Watson College of Engineering and Applied Science, Binghamton University, State University of New York, Binghamton, NY 13902, USA
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8
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Sui X, Wang K, Song K, Xu C, Song J, Lee CW, Liao M, Farese RV, Walther TC. Mechanism of action for small-molecule inhibitors of triacylglycerol synthesis. Nat Commun 2023; 14:3100. [PMID: 37248213 PMCID: PMC10227072 DOI: 10.1038/s41467-023-38934-3] [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: 11/08/2022] [Accepted: 05/23/2023] [Indexed: 05/31/2023] Open
Abstract
Inhibitors of triacylglycerol (TG) synthesis have been developed to treat metabolism-related diseases, but we know little about their mechanisms of action. Here, we report cryo-EM structures of the TG-synthesis enzyme acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), a membrane bound O-acyltransferase (MBOAT), in complex with two different inhibitors, T863 and DGAT1IN1. Each inhibitor binds DGAT1's fatty acyl-CoA substrate binding tunnel that opens to the cytoplasmic side of the ER. T863 blocks access to the tunnel entrance, whereas DGAT1IN1 extends further into the enzyme, with an amide group interacting with more deeply buried catalytic residues. A survey of DGAT1 inhibitors revealed that this amide group may serve as a common pharmacophore for inhibition of MBOATs. The inhibitors were minimally active against the related MBOAT acyl-CoA:cholesterol acyltransferase 1 (ACAT1), yet a single-residue mutation sensitized ACAT1 for inhibition. Collectively, our studies provide a structural foundation for developing DGAT1 and other MBOAT inhibitors.
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Affiliation(s)
- Xuewu Sui
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, USA
| | - Kun Wang
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Kangkang Song
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Cryo-EM Core Facility, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Chen Xu
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Cryo-EM Core Facility, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jiunn Song
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Chia-Wei Lee
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Howard Hughes Medical Institute, Boston, MA, USA.
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9
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Sharma AK, Wang T, Othman A, Khandelwal R, Balaz M, Modica S, Zamboni N, Wolfrum C. Basal re-esterification finetunes mitochondrial fatty acid utilization. Mol Metab 2023; 71:101701. [PMID: 36878315 PMCID: PMC10011057 DOI: 10.1016/j.molmet.2023.101701] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
OBJECTIVE Emerging evidence suggest the existence of constant basal lipolysis and re-esterification of a substantial fraction of thus liberated fatty acids. In stimulated lipolysis, the re-esterification is proposed to be a protective mechanism against lipotoxicity; however, the role of the lipolysis coupled to re-esterification under basal conditions has not been deciphered. METHODS We used adipocytes (in vitro differentiated brown and white adipocytes derived from a cell line or primary SVF culture) to study the effect of inhibition of re-esterification by pharmacological DGAT1 and DGAT2 inhibitors alone or in combination. We then evaluated cellular energetics, lipolysis flux, and lipidomic parameters along with mitochondrial properties and fuel utilization. RESULTS In adipocytes, DGAT1 and 2 mediated re-esterification is a moderator of fatty acid oxidation. Combined inhibition of both DGATs (D1+2i) increases oxygen consumption, which is largely due to enhanced mitochondrial respiration by lipolysis-derived fatty acids (FAs). Acute D1+2i selectively affects mitochondrial respiration without affecting the transcriptional homeostasis of genes relevant to mitochondrial health and lipid metabolism. D1+2i enhances the mitochondrial import of pyruvate and activates AMP Kinase to counteract CPT1 antagonism, thus facilitating the mitochondrial import of fatty acyl-CoA. CONCLUSIONS These data implicate the process of re-esterification in the regulation of mitochondrial FA usage and uncover a mechanism of FAO regulation via crosstalk with FA re-esterification.
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Affiliation(s)
- Anand Kumar Sharma
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland
| | - Tongtong Wang
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland
| | - Alaa Othman
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Radhika Khandelwal
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland
| | - Miroslav Balaz
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland; Laboratory of Cellular and Molecular Metabolism, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Salvatore Modica
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland
| | - Nicola Zamboni
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Christian Wolfrum
- Laboratory of Translational Nutrition Biology, Institute of Food, Nutrition and Health, ETH Zurich, Schwerzenbach, Switzerland.
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10
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Carss KJ, Deaton AM, Del Rio-Espinola A, Diogo D, Fielden M, Kulkarni DA, Moggs J, Newham P, Nelson MR, Sistare FD, Ward LD, Yuan J. Using human genetics to improve safety assessment of therapeutics. Nat Rev Drug Discov 2023; 22:145-162. [PMID: 36261593 DOI: 10.1038/s41573-022-00561-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2022] [Indexed: 02/07/2023]
Abstract
Human genetics research has discovered thousands of proteins associated with complex and rare diseases. Genome-wide association studies (GWAS) and studies of Mendelian disease have resulted in an increased understanding of the role of gene function and regulation in human conditions. Although the application of human genetics has been explored primarily as a method to identify potential drug targets and support their relevance to disease in humans, there is increasing interest in using genetic data to identify potential safety liabilities of modulating a given target. Human genetic variants can be used as a model to anticipate the effect of lifelong modulation of therapeutic targets and identify the potential risk for on-target adverse events. This approach is particularly useful for non-clinical safety evaluation of novel therapeutics that lack pharmacologically relevant animal models and can contribute to the intrinsic safety profile of a drug target. This Review illustrates applications of human genetics to safety studies during drug discovery and development, including assessing the potential for on- and off-target associated adverse events, carcinogenicity risk assessment, and guiding translational safety study designs and monitoring strategies. A summary of available human genetic resources and recommended best practices is provided. The challenges and future perspectives of translating human genetic information to identify risks for potential drug effects in preclinical and clinical development are discussed.
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Affiliation(s)
| | - Aimee M Deaton
- Amgen, Cambridge, MA, USA.,Alnylam Pharmaceuticals, Cambridge, MA, USA
| | - Alberto Del Rio-Espinola
- Novartis Institutes for BioMedical Research, Basel, Switzerland.,GentiBio Inc., Cambridge, MA, USA
| | | | - Mark Fielden
- Amgen, Thousand Oaks, MA, USA.,Kate Therapeutics, San Diego, CA, USA
| | | | - Jonathan Moggs
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | | | - Frank D Sistare
- Merck & Co., West Point, PA, USA.,315 Meadowmont Ln, Chapel Hill, NC, USA
| | - Lucas D Ward
- Amgen, Cambridge, MA, USA. .,Alnylam Pharmaceuticals, Cambridge, MA, USA.
| | - Jing Yuan
- Amgen, Cambridge, MA, USA.,Pfizer, Cambridge, MA, USA
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11
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Wang Y, Zeng F, Zhao Z, He L, He X, Pang H, Huang F, Chang P. Transmembrane Protein 68 Functions as an MGAT and DGAT Enzyme for Triacylglycerol Biosynthesis. Int J Mol Sci 2023; 24:ijms24032012. [PMID: 36768334 PMCID: PMC9916437 DOI: 10.3390/ijms24032012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
Triacylglycerol (TG) biosynthesis is an important metabolic process for intracellular storage of surplus energy, intestinal dietary fat absorption, attenuation of lipotoxicity, lipid transportation, lactation and signal transduction in mammals. Transmembrane protein 68 (TMEM68) is an endoplasmic reticulum (ER)-anchored acyltransferase family member of unknown function. In the current study we show that overexpression of TMEM68 promotes TG accumulation and lipid droplet (LD) formation in a conserved active sites-dependent manner. Quantitative targeted lipidomic analysis showed that diacylglycerol (DG), free fatty acid (FFA) and TG levels were increased by TMEM68 expression. In addition, TMEM68 overexpression affected the levels of several glycerophospholipids, such as phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol, as well as sterol ester contents. TMEM68 exhibited monoacylglycerol acyltransferase (MGAT) and diacylglycerol acyltransferase (DGAT) activities dependent on the conserved active sites in an in vitro assay. The expression of lipogenesis genes, including DGATs, fatty acid synthesis-related genes and peroxisome proliferator-activated receptor γ was upregulated in TMEM68-overexpressing cells. These results together demonstrate for the first time that TMEM68 functions as an acyltransferase and affects lipogenic gene expression, glycerolipid metabolism and TG storage in mammalian cells.
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12
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Dominguez SR, Whiles S, Deobald KN, Kawula T. Francisella tularensis Exploits AMPK Activation to Harvest Host-Derived Nutrients Liberated from Host Lipolysis. Infect Immun 2022; 90:e0015522. [PMID: 35916521 PMCID: PMC9387300 DOI: 10.1128/iai.00155-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 07/08/2022] [Indexed: 11/21/2022] Open
Abstract
Francisella tularensis is a zoonotic, facultative intracellular bacterial pathogen that replicates in a variety of cell types during infection. Following entry into the cell and phagosome escape, the bacterium replicates rapidly in the cytoplasm. F. tularensis intracellular growth depends on the availability of metabolizable essential nutrients to support replication. However, the mechanism by which metabolizable nutrients become available to the bacterium in the intracellular environment is not fully understood. We found that F. tularensis-infected cells had significantly smaller and fewer lipid droplets than uninfected cells. Inhibition of triacylglycerol degradation significantly reduced bacterial growth, whereas inhibition of triacylglycerol formation did not reduce bacterial growth, suggesting that triacylglycerols sequestered within lipid droplets are important nutrient sources for F. tularensis. We found that F. tularensis-infected cells had increased activation of lipolysis and the upstream regulatory protein AMP protein kinase (AMPK). These data suggest that F. tularensis exploits AMPK activation and lipid metabolism to use host-derived nutrients. Finally, we found that AMPK activation is correlated with an increased bacterial burden, which suggests that it is a host-mediated response to nutrient starvation that results from increased bacterial replication. Altogether, we conclude that F. tularensis exploits AMPK activation to access nutrients sequestered in lipid droplets, specifically glycerol and fatty acids, to undergo efficient bacterial replication and cause successful infection.
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Affiliation(s)
- Sedelia R. Dominguez
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
- School of Molecular Biosciences, Washington State University, Pullman, Washington, USA
| | - Shannon Whiles
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
| | - Kelly N. Deobald
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
| | - Thomas Kawula
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, USA
- School of Molecular Biosciences, Washington State University, Pullman, Washington, USA
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13
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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14
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Abstract
INTRODUCTION Primary chylomicronemia is characterized by pathological accumulation of chylomicrons in the plasma causing severe hypertriglyceridemia, typically >10 mmol/L (>875 mg/dL). Patients with the ultra-rare familial chylomicronemia syndrome (FCS) subtype completely lack lipolytic capacity and respond minimally to traditional triglyceride-lowering therapies. The mainstay of treatment is a low-fat diet, which is difficult to follow and compromises quality of life. New therapies are being developed primarily to prevent episodes of life-threatening acute pancreatitis. AREAS COVERED Antagonists of apolipoprotein (apo) C-III, such as the antisense oligonucleotide (ASO) volanesorsen, significantly reduce triglyceride levels in chylomicronemia. However, approval of and access to volanesorsen are restricted since a substantial proportion of treated FCS patients developed thrombocytopenia. Newer apo C-III antagonists, namely, the ASO olezarsen (formerly AKCEA-APOCIII-LRx) and short interfering RNA (siRNA) ARO-APOC3, appear to show efficacy with less risk of thrombocytopenia. Potential utility of antagonists of angiopoietin-like protein 3 (ANGPTL3) such as evinacumab and the siRNA ARO-ANG3 in subtypes of chylomicronemia remains to be defined. EXPERT OPINION Emerging pharmacologic therapies for chylomicronemia show promise, particularly apo C-III antagonists. However, these treatments are still investigational. Further study of their efficacy and safety in patients with both rare FCS and more common multifactorial chylomicronemia is needed.
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Affiliation(s)
- Isabel Shamsudeen
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Robert A Hegele
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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15
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Stone SJ. Mechanisms of intestinal triacylglycerol synthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159151. [PMID: 35296424 DOI: 10.1016/j.bbalip.2022.159151] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/13/2022] [Accepted: 02/16/2022] [Indexed: 02/07/2023]
Abstract
Triacylglycerols are a major source of stored energy that are obtained either from the diet or can be synthesized to some extent by most tissues. Alterations in pathways of triacylglycerol metabolism can result in their excessive accumulation leading to obesity, insulin resistance, cardiovascular disease and nonalcoholic fatty liver disease. Most tissues in mammals synthesize triacylglycerols via the glycerol 3-phosphate pathway. However, in the small intestine the monoacylglycerol acyltransferase pathway is the predominant pathway for triacylglycerol biosynthesis where it participates in the absorption of dietary triacylglycerol. In this review, the enzymes that are part of both the glycerol 3-phosphate and monoacylglycerol acyltransferase pathways and their contributions to intestinal triacylglycerol metabolism are reviewed. The potential of some of the enzymes involved in triacylglycerol synthesis in the small intestine as possible therapeutic targets for treating metabolic disorders associated with elevated triacylglycerol is briefly discussed.
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Affiliation(s)
- Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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16
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Agarwal P, Gordon S, Martinez FO. Foam Cell Macrophages in Tuberculosis. Front Immunol 2022; 12:775326. [PMID: 34975863 PMCID: PMC8714672 DOI: 10.3389/fimmu.2021.775326] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/29/2021] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis infects primarily macrophages in the lungs. Infected macrophages are surrounded by other immune cells in well organised structures called granulomata. As part of the response to TB, a type of macrophage loaded with lipid droplets arises which we call Foam cell macrophages. They are macrophages filled with lipid laden droplets, which are synthesised in response to increased uptake of extracellular lipids, metabolic changes and infection itself. They share the appearance with atherosclerosis foam cells, but their lipid contents and roles are different. In fact, lipid droplets are immune and metabolic organelles with emerging roles in Tuberculosis. Here we discuss lipid droplet and foam cell formation, evidence regarding the inflammatory and immune properties of foam cells in TB, and address gaps in our knowledge to guide further research.
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Affiliation(s)
- Pooja Agarwal
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Siamon Gordon
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Fernando O Martinez
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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17
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Kumar M, Pandey SK, Gupta D. A Convenient Cascade Strategy Towards the Synthesis of Novel Substituted Morpholinopyrimidines and Pyrimidooxazapines. LETT ORG CHEM 2022. [DOI: 10.2174/1570178618666210508232550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
A simple and novel protocol for the facile synthesis of bicyclic hybrid molecular framework
of morpholinopyrimidines having six-membered pyrimidine ring fused with the morpholine unit
is established. The method has been successfully employed to synthesize both regioisomers of
the morpholinopyrimidine derivatives in good to high yields. The strategy is further extended
successfully to synthesize bicyclic pyrimidooxazapine derivatives bearing the six-membered
aromatic pyrimidine unit fused with seven-membered aliphatic oxazapine fragment.
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Affiliation(s)
- Manoj Kumar
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University, Sec-125, Noida, India
| | | | - Deepshikha Gupta
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University, Sec-125, Noida, India
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18
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Long T, Liu Y, Li X. Molecular structures of human ACAT2 disclose mechanism for selective inhibition. Structure 2021; 29:1410-1418.e4. [PMID: 34520735 PMCID: PMC8642284 DOI: 10.1016/j.str.2021.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/13/2021] [Accepted: 07/20/2021] [Indexed: 12/14/2022]
Abstract
Endoplasmic reticulum-localized acyl-CoA:cholesterol acyltransferases (ACAT), including ACAT1 and ACAT2, convert cholesterol to cholesteryl esters that become incorporated into lipoproteins or stored in cytosolic lipid droplets. Selective inhibition of ACAT2 has been shown to considerably attenuate hypercholesterolemia and atherosclerosis in mice. Here, we report cryogenic electron microscopy structures of human ACAT2 bound to its specific inhibitor pyripyropene A or the general ACAT inhibitor nevanimibe. Structural analysis reveals that ACAT2 has a topology in membranes similar to that of ACAT1. A catalytic core with an entry site occupied by a cholesterol molecule and another site for allosteric activation of ACAT2 is observed in these structures. Enzymatic assays show that mutations within sites of cholesterol entry or allosteric activation attenuate ACAT2 activity in vitro. Together, these results reveal mechanisms for ACAT2-mediated esterification of cholesterol, providing a blueprint to design new ACAT2 inhibitors for use in the prevention of cardiovascular disease.
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Affiliation(s)
- Tao Long
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yang Liu
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiaochun Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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19
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Dawa S, Menon D, Arumugam P, Bhaskar AK, Mondal M, Rao V, Gandotra S. Inhibition of Granuloma Triglyceride Synthesis Imparts Control of Mycobacterium tuberculosis Through Curtailed Inflammatory Responses. Front Immunol 2021; 12:722735. [PMID: 34603294 PMCID: PMC8479166 DOI: 10.3389/fimmu.2021.722735] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/25/2021] [Indexed: 12/11/2022] Open
Abstract
Lipid metabolism plays a complex and dynamic role in host-pathogen interaction during Mycobacterium tuberculosis infection. While bacterial lipid metabolism is key to the success of the pathogen, the host also offers a lipid rich environment in the form of necrotic caseous granulomas, making this association beneficial for the pathogen. Accumulation of the neutral lipid triglyceride, as lipid droplets within the cellular cuff of necrotic granulomas, is a peculiar feature of pulmonary tuberculosis. The role of triglyceride synthesis in the TB granuloma and its impact on the disease outcome has not been studied in detail. Here, we identified diacylglycerol O-acyltransferase 1 (DGAT1) to be essential for accumulation of triglyceride in necrotic TB granulomas using the C3HeB/FeJ murine model of infection. Treatment of infected mice with a pharmacological inhibitor of DGAT1 (T863) led to reduction in granuloma triglyceride levels and bacterial burden. A decrease in bacterial burden was associated with reduced neutrophil infiltration and degranulation, and a reduction in several pro-inflammatory cytokines including IL1β, TNFα, IL6, and IFNβ. Triglyceride lowering impacted eicosanoid production through both metabolic re-routing and via transcriptional control. Our data suggests that manipulation of lipid droplet homeostasis may offer a means for host directed therapy in Tuberculosis.
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Affiliation(s)
- Stanzin Dawa
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Dilip Menon
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Prabhakar Arumugam
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Akash Kumar Bhaskar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Moumita Mondal
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Vivek Rao
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Sheetal Gandotra
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Cardiorespiratory Disease Biology, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
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20
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Assessing fatty acid-induced lipotoxicity and its therapeutic potential in glioblastoma using stimulated Raman microscopy. Sci Rep 2021; 11:7422. [PMID: 33795756 PMCID: PMC8016949 DOI: 10.1038/s41598-021-86789-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/16/2021] [Indexed: 01/15/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor. The effectiveness of traditional therapies for GBM is limited and therefore new therapies are highly desired. Previous studies show that lipid metabolism reprogramming may be a potential therapeutic target in GBM. This study aims to evaluate the therapeutic potential of free fatty acid-induced lipotoxicity for the suppression of glioma growth. U87 glioma cells are treated with three fatty acids (FAs): palmitic acid (PA), oleic acid (OA), and eicosapentaenoic acid (EPA). Uptake of the FAs and formation of lipid droplets (LDs) are imaged and quantified using a lab-built stimulated Raman scattering (SRS) microscope. Our results show that a supply of 200 µM PA, OA, and EPA leads to efficient LDs accumulation in glioma cells. We find that inhibition of triglycerides (TAGs) synthesis depletes LDs and enhances lipotoxicity, which is evidenced by the reduced cell proliferation rates. In particular, our results suggest that EPA treatment combined with depletion of LDs significantly reduces the survival rate of glioma cells by more than 50%, indicating the therapeutic potential of this approach. Future work will focus on understanding the metabolic mechanism of EPA-induced lipotoxicity to further enhance its anticancer effects.
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21
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Bhunia RK, Sinha K, Chawla K, Randhawa V, Sharma TR. Functional characterization of two type-1 diacylglycerol acyltransferase (DGAT1) genes from rice (Oryza sativa) embryo restoring the triacylglycerol accumulation in yeast. PLANT MOLECULAR BIOLOGY 2021; 105:247-262. [PMID: 33089420 DOI: 10.1007/s11103-020-01085-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Two OsDGAT1 genes showed the ability to restore TAG and LB synthesis in yeast H1246. Alterations in the N-terminal region of OsDGAT1-1 gene revealed its regulatory role in gene function. Accumulation of triacylglycerol (TAG) or oil in vegetative tissues has emerged as a promising approach to meet the global needs of food, feed, and fuel. Rice (Oryza sativa) has been recognized as an important cereal crop containing nutritional rice bran oil with high economic value for renewable energy production. To identify the key component involved in storage lipid biosynthesis, two type-1 diacylglycerol acyltransferases (DGAT1) from rice were characterized for its in vivo function in the H1246 (dga1, lro1, are1 and are2) yeast quadruple mutant. The ectopic expression of rice DGAT1 (designated as OsDGAT1-1 and OsDGAT1-2) genes restored the capability of TAG synthesis and lipid body (LB) formation in H1246. OsDGAT1-1 showed nearly equal substrate preferences to C16:0-CoA and 18:1-CoA whereas OsDGAT1-2 displayed substrate selectivity for C16:0-CoA over 18:1-CoA, indicating that these enzymes have contrasting substrate specificities. In parallel, we have identified the intrinsically disordered region (IDR) at the N-terminal domains of OsDGAT1 proteins. The regulatory role of the N-terminal domain was dissected. Single point mutations at the phosphorylation sites and truncations of the N-terminal region highlighted reduced lipid accumulation capabilities among different OsDGAT1-1 variants.
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Affiliation(s)
- Rupam Kumar Bhunia
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India.
| | - Kshitija Sinha
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Kirti Chawla
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Vinay Randhawa
- Department of Biochemistry, Panjab University, Chandigarh, 160014, India
| | - Tilak Raj Sharma
- Plant Tissue Culture and Genetic Engineering, National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
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22
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Huang JS, Guo BB, Lin FF, Zeng LM, Wang T, Dang XY, Yang Y, Hu YH, Liu J, Wang HY. A novel low systemic diacylglycerol acyltransferase 1 inhibitor, Yhhu2407, improves lipid metabolism. Eur J Pharm Sci 2020; 158:105683. [PMID: 33347980 DOI: 10.1016/j.ejps.2020.105683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 01/27/2023]
Abstract
Diacylglycerol acyltransferase 1 (DGAT1) plays a pivotal role in lipid metabolism by catalyzing the committed step in triglyceride (TG) synthesis and has been considered as a potential therapeutic target of multiple metabolic diseases, including dyslipidemia, obesity and type 2 diabetes. Here we report a novel DGAT1 inhibitor, Yhhu2407, which showed a stronger DGAT1 inhibitory activity (IC50 = 18.24 ± 4.72 nM) than LCQ908 (IC50 = 78.24 ± 8.16 nM) in an enzymatic assay and led to a significant reduction in plasma TG after an acute lipid challenge in mice. Pharmacokinetic studies illustrated that Yhhu2407 displayed a low systemic, liver- and intestine-targeted distribution pattern, which is consistent with the preferential tissue expression pattern of DGAT1 and therefore might help to maximize the beneficial pharmacological effects and prevent the occurrence of side effects. Cell-based investigations demonstrated that Yhhu2407 inhibited free fatty acid (FFA)-induced TG accumulation and apolipoprotein B (ApoB)-100 secretion in HepG2 cells. In vivo study also disclosed that Yhhu2407 exerted a beneficial effect on regulating plasma TG and lipoprotein levels in rats, and effectively ameliorated high-fat diet (HFD)-induced dyslipidemia in hamsters. In conclusion, we identified Yhhu2407 as a novel DGAT1 inhibitor with potent efficacy on improving lipid metabolism in rats and HFD-fed hamsters without causing obvious adverse effects.
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Affiliation(s)
- Jun-Shang Huang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bin-Bin Guo
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Fei-Fei Lin
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Li-Min Zeng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ting Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xiang-Yu Dang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yang Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - You-Hong Hu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jia Liu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - He-Yao Wang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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23
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Amin NB, Carvajal-Gonzalez S, Purkal J, Zhu T, Crowley C, Perez S, Chidsey K, Kim AM, Goodwin B. Targeting diacylglycerol acyltransferase 2 for the treatment of nonalcoholic steatohepatitis. Sci Transl Med 2020; 11:11/520/eaav9701. [PMID: 31776293 DOI: 10.1126/scitranslmed.aav9701] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/25/2019] [Accepted: 11/08/2019] [Indexed: 12/14/2022]
Abstract
Nonalcoholic steatohepatitis (NASH) is characterized by the accumulation of hepatocyte triglycerides, the synthesis of which is catalyzed by diacylglycerol acyltransferases (DGATs). Here, we investigate DGAT2 as a potential therapeutic target using an orally administered, selective DGAT2 inhibitor, PF-06427878. Treatment with PF-06427878 resulted in the reduction of hepatic and circulating plasma triglyceride concentrations and decreased lipogenic gene expression in rats maintained on a Western-type diet. In a mouse model of NASH, histological improvements in steatosis, ballooning, and fibrosis were evident in the livers of animals receiving PF-06427878 compared with mice treated with vehicle alone. We extended these nonclinical studies to two phase 1 studies in humans [NCT02855177 (n = 24) and NCT02391623 (n = 39; n = 38 completed)] and observed that PF-06427878 was well tolerated and influenced markers of liver function (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total bilirubin) in healthy adults, with statistically significant reductions from baseline at day 14 in participants treated with PF-06427878 1500 milligrams per day (P < 0.05). Moreover, magnetic resonance imaging using proton density fat fraction showed that PF-06427878 1500 milligrams per day reduced hepatic steatosis in healthy adult participants. Our findings highlight DGAT2 inhibition by a small, potent, selective compound as a potential therapeutic approach for the treatment of NASH.
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Affiliation(s)
- Neeta B Amin
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA.
| | | | - Julie Purkal
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Tong Zhu
- Early Clinical Development, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Collin Crowley
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Sylvie Perez
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Kristin Chidsey
- Early Clinical Development, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Albert M Kim
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
| | - Bryan Goodwin
- Internal Medicine Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA
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24
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Ogasawara Y, Cheng J, Tatematsu T, Uchida M, Murase O, Yoshikawa S, Ohsaki Y, Fujimoto T. Long-term autophagy is sustained by activation of CCTβ3 on lipid droplets. Nat Commun 2020; 11:4480. [PMID: 32900992 PMCID: PMC7479109 DOI: 10.1038/s41467-020-18153-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 08/07/2020] [Indexed: 12/12/2022] Open
Abstract
Macroautophagy initiates by formation of isolation membranes, but the source of phospholipids for the membrane biogenesis remains elusive. Here, we show that autophagic membranes incorporate newly synthesized phosphatidylcholine, and that CTP:phosphocholine cytidylyltransferase β3 (CCTβ3), an isoform of the rate-limiting enzyme in the Kennedy pathway, plays an essential role. In starved mouse embryo fibroblasts, CCTβ3 is initially recruited to autophagic membranes, but upon prolonged starvation, it concentrates on lipid droplets that are generated from autophagic degradation products. Omegasomes and isolation membranes emanate from around those lipid droplets. Autophagy in prolonged starvation is suppressed by knockdown of CCTβ3 and is enhanced by its overexpression. This CCTβ3-dependent mechanism is also present in U2OS, an osteosarcoma cell line, and autophagy and cell survival in starvation are decreased by CCTβ3 depletion. The results demonstrate that phosphatidylcholine synthesis through CCTβ3 activation on lipid droplets is crucial for sustaining autophagy and long-term cell survival.
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Affiliation(s)
- Yuta Ogasawara
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan
| | - Jinglei Cheng
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Tsuyako Tatematsu
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Misaki Uchida
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Omi Murase
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Shogo Yoshikawa
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Yuki Ohsaki
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, 466-8550, Japan
| | - Toyoshi Fujimoto
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan.
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25
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Castoldi A, Monteiro LB, van Teijlingen Bakker N, Sanin DE, Rana N, Corrado M, Cameron AM, Hässler F, Matsushita M, Caputa G, Klein Geltink RI, Büscher J, Edwards-Hicks J, Pearce EL, Pearce EJ. Triacylglycerol synthesis enhances macrophage inflammatory function. Nat Commun 2020; 11:4107. [PMID: 32796836 PMCID: PMC7427976 DOI: 10.1038/s41467-020-17881-3] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022] Open
Abstract
Foamy macrophages, which have prominent lipid droplets (LDs), are found in a variety of disease states. Toll-like receptor agonists drive triacylglycerol (TG)-rich LD development in macrophages. Here we explore the basis and significance of this process. Our findings indicate that LD development is the result of metabolic commitment to TG synthesis on a background of decreased fatty acid oxidation. TG synthesis is essential for optimal inflammatory macrophage activation as its inhibition, which prevents LD development, has marked effects on the production of inflammatory mediators, including IL-1β, IL-6 and PGE2, and on phagocytic capacity. The failure of inflammatory macrophages to make PGE2 when TG-synthesis is inhibited is critical for this phenotype, as addition of exogenous PGE2 is able to reverse the anti-inflammatory effects of TG synthesis inhibition. These findings place LDs in a position of central importance in inflammatory macrophage activation. As macrophages switch to a proinflammatory gylcolytic state they start to generate triglyceride-rich lipid droplets, but what function these droplets have in this context is not clear. Here the authors show that this triglyceride synthesis is requisite for prostaglandin E2 production and subsequent inflammatory activation.
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Affiliation(s)
- Angela Castoldi
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Lauar B Monteiro
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany.,Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, São Paulo, Brazil
| | - Nikki van Teijlingen Bakker
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany.,Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - David E Sanin
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Nisha Rana
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Mauro Corrado
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Alanna M Cameron
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Fabian Hässler
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Mai Matsushita
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - George Caputa
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Ramon I Klein Geltink
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Jörg Büscher
- Metabolomics Facility, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Joy Edwards-Hicks
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Erika L Pearce
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany
| | - Edward J Pearce
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg im Breisgau, Germany. .,Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany.
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26
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Vujić N, Korbelius M, Sachdev V, Rainer S, Zimmer A, Huber A, Radović B, Kratky D. Intestine-specific DGAT1 deficiency improves atherosclerosis in apolipoprotein E knockout mice by reducing systemic cholesterol burden. Atherosclerosis 2020; 310:26-36. [PMID: 32882484 PMCID: PMC7116265 DOI: 10.1016/j.atherosclerosis.2020.07.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/25/2020] [Accepted: 07/31/2020] [Indexed: 12/17/2022]
Abstract
Background and aims Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is the rate-limiting enzyme catalyzing the final step of triglyceride synthesis by esterifying a diglyceride with a fatty acid. We have previously shown that apolipoprotein E-knockout (ApoE−/−) mice lacking Dgat1 have reduced intestinal cholesterol absorption and potentiated macrophage cholesterol efflux, and consequently, exhibit attenuated atherogenesis. However, he-matopoietic Dgat1 deficiency lacked beneficial effects on atherosclerosis. Due to our recent results on the critical role of intestinal Dgat1 in murine cholesterol homeostasis, we delineated whether intestinal Dgat1 deficiency regulates atherogenesis in mice. Methods We generated intestine-specific Dgat1−/− mice on the ApoE−/− background (iDgat1−/−ApoE−/−) and determined cholesterol homeostasis and atherosclerosis development. Results When fed a Western-type diet, iDgat1−/−ApoE−/− mice exhibited a substantial decrease in fasting plasma cholesterol content in ApoB-containing lipoproteins. Although lipid absorption was delayed, iDgat1−/−ApoE−/− mice had reduced acute and fractional cholesterol absorption coupled with an elevated fecal caloric loss. In line, increased appearance of i.v. administered [3H]cholesterol in duodena and stool of iDgat1−/−ApoE−/− animals suggested potentiated cholesterol elimination. Atherosclerotic lesions were markedly smaller with beneficial alterations in plaque composition as evidenced by reduced macrophage infiltration and necrotic core size despite unaltered collagen content, indicating improved plaque stability. Conclusions Disruption of Dgat1 activity solely in the small intestine of ApoE−/− mice strongly decreased plasma cholesterol levels by abrogating the assimilation of dietary cholesterol, partly by reduced absorption and increased excretion. Consequently, the reduced cholesterol burden significantly attenuated atherogenesis and improved the lesion phenotype in iDgat1−/−ApoE−/− mice.
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Affiliation(s)
- Nemanja Vujić
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Vinay Sachdev
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Silvia Rainer
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Anton Huber
- Institute of Chemistry, University of Graz, Graz, Austria
| | - Branislav Radović
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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27
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Kumari S, Carmona AV, Tiwari AK, Trippier PC. Amide Bond Bioisosteres: Strategies, Synthesis, and Successes. J Med Chem 2020; 63:12290-12358. [PMID: 32686940 DOI: 10.1021/acs.jmedchem.0c00530] [Citation(s) in RCA: 209] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The amide functional group plays a key role in the composition of biomolecules, including many clinically approved drugs. Bioisosterism is widely employed in the rational modification of lead compounds, being used to increase potency, enhance selectivity, improve pharmacokinetic properties, eliminate toxicity, and acquire novel chemical space to secure intellectual property. The introduction of a bioisostere leads to structural changes in molecular size, shape, electronic distribution, polarity, pKa, dipole or polarizability, which can be either favorable or detrimental to biological activity. This approach has opened up new avenues in drug design and development resulting in more efficient drug candidates introduced onto the market as well as in the clinical pipeline. Herein, we review the strategic decisions in selecting an amide bioisostere (the why), synthetic routes to each (the how), and success stories of each bioisostere (the implementation) to provide a comprehensive overview of this important toolbox for medicinal chemists.
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Affiliation(s)
- Shikha Kumari
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Angelica V Carmona
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Amit K Tiwari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, The University of Toledo, Toledo, Ohio 43614, United States
| | - Paul C Trippier
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.,Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.,UNMC Center for Drug Discovery, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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28
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Silvas JA, Jureka AS, Nicolini AM, Chvatal SA, Basler CF. Inhibitors of VPS34 and lipid metabolism suppress SARS-CoV-2 replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.07.18.210211. [PMID: 32743584 PMCID: PMC7386504 DOI: 10.1101/2020.07.18.210211] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Therapeutics targeting replication of SARS coronavirus 2 (SARS-CoV-2) are urgently needed. Coronaviruses rely on host membranes for entry, establishment of replication centers and egress. Compounds targeting cellular membrane biology and lipid biosynthetic pathways have previously shown promise as antivirals and are actively being pursued as treatments for other conditions. Here, we tested small molecule inhibitors that target membrane dynamics or lipid metabolism. Included were inhibitors of the PI3 kinase VPS34, which functions in autophagy, endocytosis and other processes; Orlistat, an inhibitor of lipases and fatty acid synthetase, is approved by the FDA as a treatment for obesity; and Triacsin C which inhibits long chain fatty acyl-CoA synthetases. VPS34 inhibitors, Orlistat and Triacsin C inhibited virus growth in Vero E6 cells and in the human airway epithelial cell line Calu-3, acting at a post-entry step in the virus replication cycle. Of these the VPS34 inhibitors exhibit the most potent activity.
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Affiliation(s)
- Jesus A. Silvas
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303
- Equal contribution
| | - Alexander S. Jureka
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303
- Equal contribution
| | | | | | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, 30303
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29
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Uematsu M, Kita Y, Shimizu T, Shindou H. Multiplex fatty acid imaging inside cells by Raman microscopy. FASEB J 2020; 34:10357-10372. [PMID: 32592240 DOI: 10.1096/fj.202000514r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/13/2022]
Abstract
Visualizing intracellular fatty acids (including free and esterified form) is very useful for understanding how and where such molecules are incorporated, stored, and metabolized within cells. However, techniques of imaging multiple intracellular fatty acids have been limited by their small size, making it difficult to label and track without changing their biological and biophysical characteristics. Here, we present a new method for simultaneously visualizing up to five atomically labeled intracellular fatty acid species. For this, we utilized the distinctive Raman spectra depending on the labeling patterns and created a new, extensible opensource software to perform by-pixel analysis of extracting original spectra from mixed ones. Our multiplex imaging method revealed that fatty acids with more double bonds tend to concentrate more efficiently at lipid droplets. This novel approach contributes to reveal not only the spatial dynamics of fatty acids, but also of any other metabolites inside cells.
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Affiliation(s)
- Masaaki Uematsu
- Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan.,Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshihiro Kita
- Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan.,Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Life Sciences Core Facility, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takao Shimizu
- Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan.,Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Institute of Microbial Chemistry, Tokyo, Japan
| | - Hideo Shindou
- Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan.,Department of Lipid Science, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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30
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Metabolic reprogramming by Zika virus provokes inflammation in human placenta. Nat Commun 2020; 11:2967. [PMID: 32528049 PMCID: PMC7290035 DOI: 10.1038/s41467-020-16754-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 04/22/2020] [Indexed: 02/06/2023] Open
Abstract
The recent outbreak of Zika virus (ZIKV) was associated with birth defects and pregnancy loss when maternal infection occurs in early pregnancy, but specific mechanisms driving placental insufficiency and subsequent ZIKV-mediated pathogenesis remain unclear. Here we show, using large scale metabolomics, that ZIKV infection reprograms placental lipidome by impairing the lipogenesis pathways. ZIKV-induced metabolic alterations provide building blocks for lipid droplet biogenesis and intracellular membrane rearrangements to support viral replication. Furthermore, lipidome reprogramming by ZIKV is paralleled by the mitochondrial dysfunction and inflammatory immune imbalance, which contribute to placental damage. In addition, we demonstrate the efficacy of a commercially available inhibitor in limiting ZIKV infection, provides a proof-of-concept for blocking congenital infection by targeting metabolic pathways. Collectively, our study provides mechanistic insights on how ZIKV targets essential hubs of the lipid metabolism that may lead to placental dysfunction and loss of barrier function. Zika virus (ZIKV) infection of pregnant women is associated with pregnancy loss and birth defects, but molecular insights for the aetiology are scarce. Here the authors show that ZIKV reprograms the host lipidome to facilitate viral replication, induce mitochondria dysfunction, and cause immune imbalance, thereby identifying a potential target for ZIKV therapy.
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31
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Molecular mechanisms of hepatic insulin resistance in nonalcoholic fatty liver disease and potential treatment strategies. Pharmacol Res 2020; 159:104984. [PMID: 32502637 DOI: 10.1016/j.phrs.2020.104984] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/27/2020] [Accepted: 05/29/2020] [Indexed: 02/07/2023]
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) in the general population is estimated at 25 %, and there is currently no effective treatment of NAFLD. Although insulin resistance (IR) is not the only factor causing the pathogenesis of NAFLD, hepatic IR has a cause-effective relationship with NAFLD. Improving hepatic IR is a potential therapeutic strategy to treat NAFLD. This review highlights the molecular mechanisms of hepatic IR in the development of NAFLD. Available data on potential drugs including glucagon-like peptide 1 receptor (GLP-1) agonists, peroxisome proliferator-activated receptor (PPAR-γ/α/δ) agonists, farnesoid X receptor (FXR) agonists, etc. are carefully discussed.
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32
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Qian H, Zhao X, Yan R, Yao X, Gao S, Sun X, Du X, Yang H, Wong CCL, Yan N. Structural basis for catalysis and substrate specificity of human ACAT1. Nature 2020; 581:333-338. [DOI: 10.1038/s41586-020-2290-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 03/17/2020] [Indexed: 02/03/2023]
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33
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Sui X, Wang K, Gluchowski NL, Elliott SD, Liao M, Walther TC, Farese RV. Structure and catalytic mechanism of a human triacylglycerol-synthesis enzyme. Nature 2020; 581:323-328. [PMID: 32433611 PMCID: PMC7398557 DOI: 10.1038/s41586-020-2289-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
Abstract
Triglycerides (triacylglycerols, TGs) store metabolic energy in organisms and have industrial uses for foods and fuels. Excessive accumulation of TGs in humans causes obesity and is associated with metabolic diseases1. TG synthesis is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes2–4 whose structures and catalytic mechanisms are unknown. Here we determined the structure of dimeric human DGAT1, a member of the membrane-bound O-acyltransferase (MBOAT) family, by cryo-electron microscopy at 3.0-Å resolution. DGAT1 forms a homodimer through N-terminal segments and a hydrophobic interface, with putative active sites within the membrane region. A structure obtained with oleoyl-CoA substrate resolved at 3.2-Å shows that the CoA moiety binds DGAT1 on the cytosolic side and the acyl group lies deep within a hydrophobic channel, positioning the acyl-CoA thioester bond near an invariant catalytic histidine residue. The reaction center is located inside a large cavity, which opens laterally to the membrane bilayer, providing lipid access to the active site. A lipid-like density, possibly an acyl-acceptor molecule, is located within the reaction center, orthogonal to acyl-CoA. Insights provided by the DGAT1 structures, together with mutagenesis and functional studies, give rise to a model of catalysis for DGAT’s generation of TGs.
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Affiliation(s)
- Xuewu Sui
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Kun Wang
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Nina L Gluchowski
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA.,Department of Gastroenterology, Hepatology, and Nutrition, Boston Children's Hospital, Boston, MA, USA
| | - Shane D Elliott
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA. .,Department of Cell Biology, Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Howard Hughes Medical Institute, Boston, MA, USA.
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA. .,Department of Cell Biology, Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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34
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Structure of nevanimibe-bound tetrameric human ACAT1. Nature 2020; 581:339-343. [PMID: 32433613 DOI: 10.1038/s41586-020-2295-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 03/17/2020] [Indexed: 11/08/2022]
Abstract
Cholesterol is an essential component of mammalian cell membranes, constituting up to 50% of plasma membrane lipids. By contrast, it accounts for only 5% of lipids in the endoplasmic reticulum (ER)1. The ER enzyme sterol O-acyltransferase 1 (also named acyl-coenzyme A:cholesterol acyltransferase, ACAT1) transfers a long-chain fatty acid to cholesterol to form cholesteryl esters that coalesce into cytosolic lipid droplets. Under conditions of cholesterol overload, ACAT1 maintains the low cholesterol concentration of the ER and thereby has an essential role in cholesterol homeostasis2,3. ACAT1 has also been implicated in Alzheimer's disease4, atherosclerosis5 and cancers6. Here we report a cryo-electron microscopy structure of human ACAT1 in complex with nevanimibe7, an inhibitor that is in clinical trials for the treatment of congenital adrenal hyperplasia. The ACAT1 holoenzyme is a tetramer that consists of two homodimers. Each monomer contains nine transmembrane helices (TMs), six of which (TM4-TM9) form a cavity that accommodates nevanimibe and an endogenous acyl-coenzyme A. This cavity also contains a histidine that has previously been identified as essential for catalytic activity8. Our structural data and biochemical analyses provide a physical model to explain the process of cholesterol esterification, as well as details of the interaction between nevanimibe and ACAT1, which may help to accelerate the development of ACAT1 inhibitors to treat related diseases.
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35
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Wang L, Qian H, Nian Y, Han Y, Ren Z, Zhang H, Hu L, Prasad BVV, Laganowsky A, Yan N, Zhou M. Structure and mechanism of human diacylglycerol O-acyltransferase 1. Nature 2020; 581:329-332. [PMID: 32433610 PMCID: PMC7255049 DOI: 10.1038/s41586-020-2280-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 03/17/2020] [Indexed: 12/27/2022]
Abstract
Diacylglycerol O-acyltransferase-1 (DGAT1) synthesizes triacylglycerides and is required for dietary fat absorption and fat storage in humans1. DGAT1 belongs to the superfamily of membrane-bound O-acyltransferases (MBOAT) that are found in all kingdoms of life and involved in acylation of lipids and proteins2,3. It remains unclear how human DGAT1 (hDGAT1) or other mammalian members of the MBOAT family recognize their substrates and catalyze their reactions. The absence of three-dimensional structures also hampers rational targeting of hDGAT1 for therapeutic purposes. Here we present the structure of hDGAT1 in complex with a substrate oleoyl Coenzyme A solved by cryo-electron microscopy. Each hDGAT1 protomer has nine transmembrane helices and eight of which form a conserved structural fold that we define as the MBOAT fold. The MBOAT fold in hDGAT1 carves out a hollow chamber in the membrane that encloses highly conserved catalytic residues. The chamber has separate entrances for the two substrates fatty acyl Coenzyme A and diacylglycerol. hDGAT1 can exist as either a homodimer or homotetramer and the two forms have similar enzymatic activity. The N-terminus of hDGAT1 interacts with the neighboring protomer and these interactions are required for the enzymatic activity.
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Affiliation(s)
- Lie Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hongwu Qian
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Yin Nian
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.,Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yimo Han
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.,Department of Material Science and Nanoengineering, Rice University, Houston, TX, USA
| | - Zhenning Ren
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hanzhi Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Liya Hu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - B V Venkataram Prasad
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
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Free Fatty Acid-Induced Peptide YY Expression Is Dependent on TG Synthesis Rate and Xbp1 Splicing. Int J Mol Sci 2020; 21:ijms21093368. [PMID: 32397573 PMCID: PMC7247705 DOI: 10.3390/ijms21093368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/06/2020] [Accepted: 05/08/2020] [Indexed: 12/27/2022] Open
Abstract
Gut-derived satiety hormones provide negative feedback to suppress food intake and maintain metabolic function in peripheral tissues. Despite the wealth of knowledge of the systemic effects of these hormones, very little is known concerning the mechanisms by which nutrients, such as dietary fats, can promote the expression of genes involved in L-cell hormone production. We have tested the role of various dietary fats and found that after hydrolysis into free fatty acids (FFA’s), there is a differential response in the extent to which they induce PYY gene and protein production. The effect of FFA’s also seems to relate to triglyceride (TG) re-esterification rate, with MUFA re-esterifying faster with lower PYY production. We have also found that there are differences in potency of FFA’s based on their desaturation patterns in vitro. The potency effect of FFA’s is influenced by the rate of TG re-esterification, such that the longer FFA’s are in contact with L-cells, the more PYY they produce. We found that chronic consumption of high-fat diets enables the small intestine to re-esterify FFA’s into TG faster and earlier which resulted in a blunted postprandial PYY response. Lastly, we found that FFA’s induce X-box-binding protein-1 activation (Xbp1s) in L-cells and that adenoviral delivery of Xbp1s was sufficient to induce PYY gene expression. Taken together, the present work indicates that dietary fat can induce satiety, in part, prior to re-esterification. Chronic high-fat diet consumption increases the rate of re-esterification which diminishes satiety and may lead to increased food intake. Targeting intestinal TG synthesis may prove beneficial in restoring obesity-associated reductions in postprandial satiety.
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Belete TM. A Recent Achievement In the Discovery and Development of Novel Targets for the Treatment of Type-2 Diabetes Mellitus. J Exp Pharmacol 2020; 12:1-15. [PMID: 32021494 PMCID: PMC6959499 DOI: 10.2147/jep.s226113] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Type 2 diabetes (T2DM) is a chronic metabolic disorder. Impaired insulin secretion, enhanced hepatic glucose production, and suppressed peripheral glucose use are the main defects responsible for developing the disease. Besides, the pathophysiology of T2DM also includes enhanced glucagon secretion, decreased incretin secretion, increased renal glucose reabsorption, and adipocyte, and brain insulin resistance. The increasing prevalence of T2DM in the world beseeches an urgent need for better treatment options. The antidiabetic drugs focus on control of blood glucose concentration, but the future treatment goal is to delay disease progression and treatment failure, which causes poorer glycemic regulation. Recent treatment approaches target on several novel pathophysiological defects present in T2DM. Some of the promising novel targets being under clinical development include those that increase insulin sensitization (antagonists of glucocorticoids receptor), decreasing hepatic glucose production (glucagon receptor antagonist, inhibitors of glycogen phosphorylase and fructose-1,6-biphosphatase). This review summarizes studies that are available on novel targets being studied to treat T2DM with an emphasis on the small molecule drug design. The experience gathered from earlier studies and knowledge of T2DM pathways can guide the anti-diabetic drug development toward the discovery of drugs essential to treat T2DM.
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Affiliation(s)
- Tafere Mulaw Belete
- Department of Pharmacology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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Abstract
Introduction: Obesity is compounded by a neurobiology that is resistant to weight loss. Therefore, the development of pharmacotherapies to address the pathology underlying the dysregulation of energy homeostasis is critical.Areas covered: This review examines selected clinical trial evidence for the pharmacologic treatment of obesity and provides an expert opinion on anti-obesity drug development. The article includes the outcomes of anti-obesity medications that have been evaluated in clinical trials but have not yet received approval from the U.S. Food and Drug Administration. The mechanisms of action of glucagon-like peptide-1 agonists and co-agonists, diabetes medications being investigated for weight loss, and medications acting on the central nervous system as well as peripherally are reviewed. A search was conducted on PubMed using the terms 'Obesity AND Medications' restricted to clinical trials reported in English. Using similar terms, a search was also conducted on ClinicalTrials.gov.Expert opinion: The goal of anti-obesity therapy is finding compounds that are effective and have minimal side effects. Combining medications targeting more than one of the redundant mechanisms driving obesity increases efficacy. However, targeting peripheral mechanisms to overcome the trickle-down effects of centrally acting drugs may be the key to success in treating obesity.
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Affiliation(s)
- Candida J Rebello
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
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Haaker MW, Kruitwagen HS, Vaandrager AB, Houweling M, Penning LC, Molenaar MR, van Wolferen ME, Oosterhoff LA, Spee B, Helms JB. Identification of potential drugs for treatment of hepatic lipidosis in cats using an in vitro feline liver organoid system. J Vet Intern Med 2019; 34:132-138. [PMID: 31830357 PMCID: PMC6979087 DOI: 10.1111/jvim.15670] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/12/2019] [Indexed: 01/18/2023] Open
Abstract
Background Hepatic lipidosis is increasing in incidence in the Western world, with cats being particularly sensitive. When cats stop eating and start utilizing their fat reserves, free fatty acids (FFAs) increase in blood, causing an accumulation of triacylglycerol (TAG) in the liver. Objective Identifying potential new drugs that can be used to treat hepatic lipidosis in cats using a feline hepatic organoid system. Animals Liver organoids obtained from 6 cats. Methods Eight different drugs were tested, and the 2 most promising were further studied using a quantitative TAG assay, lipid droplet staining, and qPCR. Results Both T863 (a diacylglycerol O‐acyltransferase 1 [DGAT1] inhibitor) and 5‐aminoimidazole‐4‐carboxamide 1‐β‐D‐ribofuranoside (AICAR; an adenosine monophosphate kinase activator) decreased TAG accumulation by 55% (P < .0001) and 46% (P = .0003), respectively. Gene expression of perilipin 2 (PLIN2) increased upon the addition of FFAs to the medium and decreased upon treatment with AICAR but not significantly after treatment with T863. Conclusions and Clinical Importance Two potential drugs useful in the treatment of hepatic lipidosis in cats were identified. The drug T863 inhibits DGAT1, indicating that DGAT1 is the primary enzyme responsible for TAG synthesis from external fatty acids in cat organoids. The drug AICAR may act as a lipid‐lowering compound via decreasing PLIN2 mRNA. Liver organoids can be used as an in vitro tool for drug testing in a species‐specific system and provide the basis for further clinical testing of drugs to treat steatosis.
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Affiliation(s)
- Maya W Haaker
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Hedwig S Kruitwagen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Arie B Vaandrager
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Martin Houweling
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Louis C Penning
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Martijn R Molenaar
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Monique E van Wolferen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Loes A Oosterhoff
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Bart Spee
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - J Bernd Helms
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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Jo SI, Bae JH, Kim SJ, Lee JM, Jeong JH, Moon JS. PF-04620110, a Potent Antidiabetic Agent, Suppresses Fatty Acid-Induced NLRP3 Inflammasome Activation in Macrophages. Diabetes Metab J 2019; 43:683-699. [PMID: 31694081 PMCID: PMC6834844 DOI: 10.4093/dmj.2019.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/19/2019] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Chronic inflammation has been linked to insulin resistance and type 2 diabetes mellitus (T2DM). High-fat diet (HFD)-derived fatty acid is associated with the activation of chronic inflammation in T2DM. PF-04620110, which is currently in phase 1 clinical trials as a selective acyl-CoA:diacylglycerol acyltransferase-1 (DGAT1) inhibitor, is a potent anti-diabetic agent that may be important for the regulation of chronic inflammation in T2DM. However, the mechanisms by which PF-04620110 regulates fatty acid-induced chronic inflammation remain unclear. METHODS PF-04620110 was used in vitro and in vivo. DGAT1-targeting gRNAs were used for deletion of mouse DGAT1 via CRISPR ribonucleoprotein (RNP) system. The activation of NLRP3 inflammasome was measured by immunoblot or cytokine analysis in vitro and in vivo. RESULTS Here we show that PF-04620110 suppressed fatty acid-induced nucleotide-binding domain, leucine-rich-repeat-containing receptor (NLR), pyrin-domain-containing 3 (NLRP3) inflammasome activation in macrophages. In contrast, PF-04620110 did not change the activation of the NLR family, CARD-domain-containing 4 (NLRC4), or the absent in melanoma 2 (AIM2) inflammasomes. Moreover, PF-04620110 inhibited K⁺ efflux and the NLRP3 inflammasome complex formation, which are required for NLRP3 inflammasome activation. PF-04620110 reduced the production of interleukin 1β (IL-1β) and IL-18 and blood glucose levels in the plasma of mice fed HFD. Furthermore, genetic inhibition of DGAT1 suppressed fatty acid-induced NLRP3 inflammasome activation. CONCLUSION Our results suggest that PF-04620110 suppresses fatty acid-induced NLRP3 inflammasome activation.
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Affiliation(s)
- Seung Il Jo
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Jung Hwan Bae
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Seong Jin Kim
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Jong Min Lee
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Ji Hun Jeong
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea
| | - Jong Seok Moon
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan, Korea.
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41
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He F, Zheng W, Chen Y, Mo C, Chen Y. Development and validation of a simple and sensitive high‐resolution LC/MS method for determination of PF‐04620110 in dog plasma: Application to a pharmacokinetic study. Biomed Chromatogr 2019; 33:e4562. [DOI: 10.1002/bmc.4562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/21/2019] [Accepted: 04/17/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Fan He
- Guangzhou Women and Children's Medical Center Guangzhou China
| | - Wei Zheng
- Guangzhou Women and Children's Medical Center Guangzhou China
| | - Yongzhuang Chen
- Guangzhou Women and Children's Medical Center Guangzhou China
| | - Chengke Mo
- Guangzhou Women and Children's Medical Center Guangzhou China
| | - Yilu Chen
- Guangzhou Women and Children's Medical Center Guangzhou China
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42
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Glicksberg BS, Amadori L, Akers NK, Sukhavasi K, Franzén O, Li L, Belbin GM, Ayers KL, Shameer K, Badgeley MA, Johnson KW, Readhead B, Darrow BJ, Kenny EE, Betsholtz C, Ermel R, Skogsberg J, Ruusalepp A, Schadt EE, Dudley JT, Ren H, Kovacic JC, Giannarelli C, Li SD, Björkegren JLM, Chen R. Integrative analysis of loss-of-function variants in clinical and genomic data reveals novel genes associated with cardiovascular traits. BMC Med Genomics 2019; 12:108. [PMID: 31345219 PMCID: PMC6657044 DOI: 10.1186/s12920-019-0542-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background Genetic loss-of-function variants (LoFs) associated with disease traits are increasingly recognized as critical evidence for the selection of therapeutic targets. We integrated the analysis of genetic and clinical data from 10,511 individuals in the Mount Sinai BioMe Biobank to identify genes with loss-of-function variants (LoFs) significantly associated with cardiovascular disease (CVD) traits, and used RNA-sequence data of seven metabolic and vascular tissues isolated from 600 CVD patients in the Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task (STARNET) study for validation. We also carried out in vitro functional studies of several candidate genes, and in vivo studies of one gene. Results We identified LoFs in 433 genes significantly associated with at least one of 10 major CVD traits. Next, we used RNA-sequence data from the STARNET study to validate 115 of the 433 LoF harboring-genes in that their expression levels were concordantly associated with corresponding CVD traits. Together with the documented hepatic lipid-lowering gene, APOC3, the expression levels of six additional liver LoF-genes were positively associated with levels of plasma lipids in STARNET. Candidate LoF-genes were subjected to gene silencing in HepG2 cells with marked overall effects on cellular LDLR, levels of triglycerides and on secreted APOB100 and PCSK9. In addition, we identified novel LoFs in DGAT2 associated with lower plasma cholesterol and glucose levels in BioMe that were also confirmed in STARNET, and showed a selective DGAT2-inhibitor in C57BL/6 mice not only significantly lowered fasting glucose levels but also affected body weight. Conclusion In sum, by integrating genetic and electronic medical record data, and leveraging one of the world’s largest human RNA-sequence datasets (STARNET), we identified known and novel CVD-trait related genes that may serve as targets for CVD therapeutics and as such merit further investigation. Electronic supplementary material The online version of this article (10.1186/s12920-019-0542-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Benjamin S Glicksberg
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Bakar Computational Health Sciences Institute, University of California San Francisco, San Francisco, 94158, CA, USA
| | - Letizia Amadori
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Cardiovascular Research Center and Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Nicholas K Akers
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Katyayani Sukhavasi
- Department of Pathophysiology, Institute of Biomedicine and Translation Medicine, University of Tartu, Biomeedikum, Ravila 19, 50411, Tartu, Estonia
| | - Oscar Franzén
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Clinical Gene Networks AB, Jungfrugatan 10, 114 44, Stockholm, Sweden.,Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska Institutet, Novum, 14157, Huddinge, Sweden
| | - Li Li
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Gillian M Belbin
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Kristin L Ayers
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT, 06902, USA
| | - Khader Shameer
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Marcus A Badgeley
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Kipp W Johnson
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Ben Readhead
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Bruce J Darrow
- Cardiovascular Research Center and Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Eimear E Kenny
- Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Raili Ermel
- Department of Cardiac Surgery, Tartu University Hospital, 1a Ludwig Puusepa Street, 50406, Tartu, Estonia
| | - Josefin Skogsberg
- Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska Institutet, Karolinska Universitetssjukhuset Huddinge, 141 86, Stockholm, Sweden
| | - Arno Ruusalepp
- Clinical Gene Networks AB, Jungfrugatan 10, 114 44, Stockholm, Sweden.,Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Eric E Schadt
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Clinical Gene Networks AB, Jungfrugatan 10, 114 44, Stockholm, Sweden.,Sema4, a Mount Sinai venture, Stamford, CT, 06902, USA
| | - Joel T Dudley
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,The Institute for Next Generation Healthcare, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Department of Health Policy and Research, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Hongxia Ren
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Center for Diabetes and Metabolic Diseases, Stark Neurosciences Research Institute, Indiana University, 635 Barnhill Dr., MS2049, Indianapolis, IN, 46202, USA
| | - Jason C Kovacic
- Cardiovascular Research Center and Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Chiara Giannarelli
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA.,Cardiovascular Research Center and Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Shuyu D Li
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA. .,Sema4, a Mount Sinai venture, Stamford, CT, 06902, USA.
| | - Johan L M Björkegren
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA. .,Department of Pathophysiology, Institute of Biomedicine and Translation Medicine, University of Tartu, Biomeedikum, Ravila 19, 50411, Tartu, Estonia. .,Clinical Gene Networks AB, Jungfrugatan 10, 114 44, Stockholm, Sweden. .,Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska Institutet, Karolinska Universitetssjukhuset Huddinge, 141 86, Stockholm, Sweden.
| | - Rong Chen
- Department of Genetics and Genomic Sciences, The Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA. .,Sema4, a Mount Sinai venture, Stamford, CT, 06902, USA.
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Morentin Gutierrez P, Yates J, Nilsson C, Birtles S. Evolving data analysis of an Oral Lipid Tolerance Test toward the standard for the Oral Glucose Tolerance Test: Cross species modeling effects of AZD7687 on plasma triacylglycerol. Pharmacol Res Perspect 2019; 7:e00465. [PMID: 30899516 PMCID: PMC6408865 DOI: 10.1002/prp2.465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 12/03/2018] [Accepted: 12/28/2018] [Indexed: 12/28/2022] Open
Abstract
We have developed a novel mechanistic pharmacokinetic-pharmacodynamic (PK/PD) model to describe the time course of plasma triglyceride (TAG) after Oral Lipid Tolerance Test (OLTT) and the effects of AZD7687, an inhibitor of diacylglycerol acyltransferase 1 (DGAT1), in humans, rats, and mice. Pharmacokinetic and plasma TAG data were obtained both in animals and in two phase I OLTT studies. In the PK/PD model, the introduction of exogenous TAG is represented by a first order process. The endogenous production and removal of TAG from plasma are described with a turnover model. AZD7687 inhibits the contribution of exogenous TAG into circulation. One or two compartment models with first order absorption was used to describe the PK of AZD7687 for the different species. Nonlinear mixed effect modeling was used to fit the model to the data. The effects of AZD7687 on the plasma TAG time course during an OLTT as well as interindividual variability were well described by the model in all three species. Meal fat content or data from single vs repeated dosing did not affect model parameter estimates. Body mass index was found to be a significant covariate on the plasma TAG baseline. The system parameters of the model will facilitate analysis for other compounds and provide tools to bring the standard of OLTT data analysis closer to the analyses of Oral Glucose Tolerance Test data maximizing knowledge gain.
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Affiliation(s)
| | - James Yates
- AstraZeneca R&DIMEDDMPKChesterford Science ParkUK
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Nardi F, Franco OE, Fitchev P, Morales A, Vickman RE, Hayward SW, Crawford SE. DGAT1 Inhibitor Suppresses Prostate Tumor Growth and Migration by Regulating Intracellular Lipids and Non-Centrosomal MTOC Protein GM130. Sci Rep 2019; 9:3035. [PMID: 30816200 PMCID: PMC6395665 DOI: 10.1038/s41598-019-39537-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/31/2018] [Indexed: 11/10/2022] Open
Abstract
Acyl-CoA:diacylglycerol acyltransferase I (DGAT1) is a key enzyme in lipogenesis which is increased in metabolically active cells to meet nutrient requirements. DGAT1 has been recognized as an anti-obesity target; however, its role in the tumor microenvironment remains unclear. We postulated that, in prostate cancer (PCa) cells, augmented lipogenesis and growth are due to increased DGAT1 expression leading to microtubule-organizing center (MTOC) amplification. Thus, therapeutic targeting of DGAT1 potentially has tumor suppressive activity. We tested whether blocking DGAT1 in PCa cells altered MTOC and lipid signaling. Western blot and immunofluorescence were performed for MTOC and triglyceride mediators. Treatment with a DGAT1 inhibitor was evaluated. We found a stepwise increase in DGAT1 protein levels when comparing normal prostate epithelial cells to PCa cells, LNCaP and PC-3. Lipid droplets, MTOCs, and microtubule-regulating proteins were reduced in tumor cells treated with a DGAT1 inhibitor. Depletion of the non-centrosomal MTOC protein GM130 reduced PCa cell proliferation and migration. Inhibition of DGAT1 reduced tumor growth both in vitro and in vivo, and a negative feedback loop was discovered between DGAT1, PEDF, and GM130. These data identify DGAT1 as a promising new target for suppressing PCa growth by regulating GM130, MTOC number and disrupting microtubule integrity.
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Affiliation(s)
- Francesca Nardi
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Omar E Franco
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Philip Fitchev
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Alejandro Morales
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Renee E Vickman
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Simon W Hayward
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States
| | - Susan E Crawford
- Department of Surgery, NorthShore University Research Institute, Affiliate of University of Chicago Pritzker School of Medicine, Evanston, IL, 60201, United States.
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45
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Mu W, Cheng XF, Liu Y, Lv QZ, Liu GL, Zhang JG, Li XY. Potential Nexus of Non-alcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus: Insulin Resistance Between Hepatic and Peripheral Tissues. Front Pharmacol 2019; 9:1566. [PMID: 30692925 PMCID: PMC6339917 DOI: 10.3389/fphar.2018.01566] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/24/2018] [Indexed: 12/21/2022] Open
Abstract
The liver is the central metabolic organ and plays a pivotal role in regulating homeostasis of glucose and lipid metabolism. Aberrant liver metabolism promotes insulin resistance, which is reported to be a common characteristic of metabolic diseases such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). There is a complex and bidirectional relationship between NAFLD and T2DM. NAFLD patients with hepatic insulin resistance generally share a high risk of impaired fasting glucose associated with early diabetes; most patients with T2DM experience non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and other more severe liver complications such as cirrhosis and hepatocellular carcinoma (HCC). Additionally, hepatic insulin resistance, which is caused by diacylglycerol-mediated activation of protein kinase C epsilon (PKC𝜀), may be the critical pathological link between NAFLD and T2DM. Therefore, this review aims to illuminate current insights regarding the complex and strong association between NAFLD and T2DM and summarize novel and emerging targets for the treatment of hepatic insulin resistance based on established mechanistic knowledge.
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Affiliation(s)
- Wan Mu
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xue-Fang Cheng
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Liu
- Department of Pharmacy, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qian-Zhou Lv
- Department of Pharmacy, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Gao-Lin Liu
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ji-Gang Zhang
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Yu Li
- Department of Pharmacy, Zhongshan Hospital, Fudan University, Shanghai, China
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46
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Hernández-Corbacho MJ, Obeid LM. A novel role for DGATs in cancer. Adv Biol Regul 2018; 72:89-101. [PMID: 30579761 DOI: 10.1016/j.jbior.2018.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/09/2018] [Accepted: 12/10/2018] [Indexed: 02/06/2023]
Affiliation(s)
- María José Hernández-Corbacho
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY, 11794, USA
| | - Lina M Obeid
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY, 11794, USA; The Northport VA Medical Center, Northport, NY, 11768, USA.
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47
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Novel Approaches To Kill Toxoplasma gondii by Exploiting the Uncontrolled Uptake of Unsaturated Fatty Acids and Vulnerability to Lipid Storage Inhibition of the Parasite. Antimicrob Agents Chemother 2018; 62:AAC.00347-18. [PMID: 30061287 DOI: 10.1128/aac.00347-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/21/2018] [Indexed: 12/17/2022] Open
Abstract
Toxoplasma gondii, an obligate intracellular parasite replicating in mammalian cells within a parasitophorous vacuole (PV), is an avid scavenger of lipids retrieved from the host cell. Following lipid uptake, this parasite stores excess lipids in lipid droplets (LD). Here, we examined the lipid storage capacities of Toxoplasma upon supplementation of the culture medium with various fatty acids at physiological concentrations. Supplemental unsaturated fatty acids (oleate [OA], palmitoleate, linoleate) accumulate in large LD and impair parasite replication, whereas saturated fatty acids (palmitate, stearate) neither stimulate LD formation nor impact growth. Examination of parasite growth defects with 0.4 mM OA revealed massive lipid deposits outside LD, indicating enzymatic inadequacies for storing neutral lipids in LD in response to the copious salvage of OA. Toxoplasma exposure to 0.5 mM OA led to irreversible growth arrest and lipid-induced damage, confirming a major disconnect between fatty acid uptake and the parasite's cellular lipid requirements. The importance of neutral lipid synthesis and storage to avoid lipotoxicity was further highlighted by the selective vulnerability of Toxoplasma, both the proliferative and the encysted forms, to subtoxic concentrations of the acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1) pharmacological inhibitor T863. T863-treated parasites did not form LD but instead built up large membranous structures within the cytoplasm, which suggests improper channeling and management of the excess lipid. Dual addition of OA and T863 to infected cells intensified the deterioration of the parasite. Overall, our data pinpoint Toxoplasma DGAT as a promising drug target for the treatment of toxoplasmosis that would not incur the risk of toxicity for mammalian cells.
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48
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Chae YJ, Song JS, Ahn JH, Bae MA, Lee KR. Model-based pharmacokinetic and pharmacodynamic analysis for acute effects of a small molecule inhibitor of diacylglycerol acyltransferase-1 in the TallyHo/JngJ polygenic mouse. Xenobiotica 2018; 49:823-832. [PMID: 29972081 DOI: 10.1080/00498254.2018.1496303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The purpose of this study was to evaluate the acute effect of a small molecule inhibitor of DGAT-1 on triglycerides (TG) and cholesterol in polygenic type 2 diabetic TallyHo/JngJ (TH) mice. PF-04620110, a potent and selective DGAT-1 inhibitor, was used as a model compound in this study and which was administered to TH and ICR mice. The concentration of the model compound that produced 50% of maximum lowering of TG level (IC50) in TH mice was not significantly different from that in ICR mice, when estimated using the model-based pharmacokinetic and pharmacodynamic assay, a two-compartmental model and an indirect response model. The clearance of the inhibitor in TH mice was fivefold higher than that in ICR mice, suggesting significantly altered pharmacokinetics. Moreover, the in vitro metabolic elimination kinetic parameters (ke,met), determined using liver microsomes from TH and ICR mice were 1.24 ± 0.14 and 0.174 ± 0.116 min-1, respectively. Thus, we report that the differences in the acute effects of the small molecule DAGT-1 inhibitor between TH mice and ICR mice can be attributed to altered pharmacokinetics caused by an altered metabolic rate for the compound in TH mice.
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Affiliation(s)
- Yoon-Jee Chae
- a CKD Research Institute , Gyeonggi-do, Republic of Korea
| | - Jin Sook Song
- b Bio & Drug Discovery Division , Korea Research Institute of Chemical Technology , Daejeon , Republic of Korea
| | - Jin Hee Ahn
- c Department of Chemistry , Gwangju Institute of Science and Technology , Gwangju , Republic of Korea
| | - Myung Ae Bae
- b Bio & Drug Discovery Division , Korea Research Institute of Chemical Technology , Daejeon , Republic of Korea.,d Department of Medicinal Chemistry and Pharmacology , University of Science & Technology , Daejeon , Republic of Korea
| | - Kyeong-Ryoon Lee
- e Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology , Chungbuk , Republic of Korea
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Jaisinghani N, Dawa S, Singh K, Nandy A, Menon D, Bhandari PD, Khare G, Tyagi A, Gandotra S. Necrosis Driven Triglyceride Synthesis Primes Macrophages for Inflammation During Mycobacterium tuberculosis Infection. Front Immunol 2018; 9:1490. [PMID: 30018616 PMCID: PMC6037689 DOI: 10.3389/fimmu.2018.01490] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/15/2018] [Indexed: 01/01/2023] Open
Abstract
Pulmonary tuberculosis (TB) exhibits granulomatous inflammation, a site of controlling bacterial dissemination at the cost of host tissue damage. Intrigued by the granuloma type-dependent expression of inflammatory markers in TB, we sought to investigate underlying metabolic changes that drive amplification of inflammation in TB. Here, we show an association of higher inflammation in necrotic granulomas with the presence of triglyceride (TG)-rich foamy macrophages. The conspicuous absence of these macrophages in solid granulomas identified a link between the ensuing pathology and the metabolic programming of foamy macrophages. Consistent with in vivo findings, in vitro infection of macrophages with Mycobacterium tuberculosis (Mtb) led to increase in TG synthesis only under conditions of ~60% necrosis. Genetic and pharmacologic intervention that reduced necrosis prevented this bystander response. We further demonstrate that necrosis independent of Mtb also elicits the same bystander response in human macrophages. We identified a role for the human enzyme involved in TG synthesis, diacylglycerol O-acyltransferase (DGAT1), in this phenomenon. The increased TG levels in necrosis-associated foamy macrophages promoted the pro-inflammatory state of macrophages to infection while silencing expression of diacylglycerol O-acyltransferase (DGAT1) suppressed expression of pro-inflammatory genes. Our data thus invoke a role for storage lipids in the heightened host inflammatory response during infection-associated necrosis. Our data provide a functional role to macrophage lipid droplets in host defense and open new avenues for developing host-directed therapies against TB.
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Affiliation(s)
- Neetika Jaisinghani
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Stanzin Dawa
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Kaurab Singh
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Ananya Nandy
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Dilip Menon
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Purva Deepak Bhandari
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Garima Khare
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Anil Tyagi
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India.,Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Sheetal Gandotra
- Chemical and Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
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50
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Kim MO, Seo JH, Kwon EB, Kang MJ, Lee SU, Moon DO, Lee MK, Lee CH, Lee HS. Aceriphyllum rossii Exerts Lipid-Lowering Action in Both Normal and Hyperlipidemic Mice. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801300423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This study aimed to evaluate the lipid-lowering effect of the MeOH extract of Aceriphyllum rossii and its CHCl3 fraction, as well as its inhibitory activity on DGAT in vitro, in normal and hyperlipidemic mice. We separated the MeOH extract of A. rossii into two portions, a CHCl3-soluble part and the remaining water residue, and performed DGAT enzymatic activity assay on them. Further assessment carried out to reveal that the MeOH extract and its CHCl3 fraction suppress the intestinal TG absorption after an acute lipid challenge, and ameliorate hyperlipidemia as well as obesity-related parameters (body weight gain, serum lipid profiles, and several adipose tissue weights) in HFD-induced obese mice. First, the MeOH extract and its CHCl3 fraction strongly inhibit DGAT1 and DGAT2 in vitro enzymatic activity. Second, the MeOH extract and the CHCl3 fraction inhibit intestinal TG absorption after an acute lipid challenge in mice. Finally, the CHCl3 fraction ameliorates various parameters of HFD-induced obesity mice, including body weight gain and serum levels of TG and glucose. Data obtained from the results obviously indicated that A. rossii prevents HFD-induced hyperlipidemia as well as obesity in mice possibly by inhibiting DGAT activity. We suggest that A. rossii MeOH extract and its CHCl3 fraction would be a useful material for the therapy of hyperlipidemia.
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Affiliation(s)
- Mun Ock Kim
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
| | - Jee Hee Seo
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
| | - Eun Bin Kwon
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Myung Ji Kang
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Su Ui Lee
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
| | - Dong Oh Moon
- Department of Biology Education, Daegu University, Gyeongsan-si, Gyeongsangbuk 38453, Republic of Korea
| | - Mi Kyeong Lee
- College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Chul-Ho Lee
- Laboratory Animal Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hyun Sun Lee
- Natural Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, 30, Yeongudanji-ro, Ochang, Cheongju, Chungbuk 28116, Republic of Korea
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