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Buneeva OA, Fedchenko VI, Kaloshina SA, Zavyalova MG, Zgoda VG, Medvedev AE. Comparative proteomic analysis of renal tissue of normotensive and hypertensive rats. BIOMEDITSINSKAIA KHIMIIA 2024; 70:89-98. [PMID: 38711408 DOI: 10.18097/pbmc20247002089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Comparative proteomic analysis of kidney tissue from normotensive (WKY) and spontaneously hypertensive (SHR) rats revealed quantitative and qualitative changes in renal proteins. The number of renal proteins specific for WKY rats (blood pressure 110-120 mm Hg) was 13-16. There were 20-24 renal proteins specific for SHR (blood pressure 180 mm Hg and more). The total number of identified renal proteins common for both rat strains included 972-975 proteins. A pairwise comparison of all possible (SHR-WKY) variants identified 8 proteins specific only for normotensive (WKY) animals, and 7 proteins specific only for hypertensive ones (SHR). Taking into consideration their biological roles, the lack of some enzyme proteins in hypertensive rats (for example, biliverdin reductase A) reduces the production of molecules exhibiting antihypertensive properties, while the appearance of others (e.g. betaine-homocysteine S-methyltransferase 2, septin 2, etc.) can be interpreted as a compensatory reaction. Renal proteins with altered relative content (with more than 2.5-fold change) accounted for no more than 5% of all identified proteins. Among the proteins with an increased relative content in hypertensive animals, the largest group consisted of proteins involved in the processes of energy generation and carbohydrate metabolism, as well as antioxidant and protective proteins. In the context of the development of hypertension, the identified relative changes can apparently be considered compensatory. Among the proteins with the most pronounced decrease in the relative content in hypertensive rats, the dramatic reduction in acyl-CoA medium-chain synthetase-3 (ACSM3) appears to make an important contribution to the development of renal pathology in these animals.
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Affiliation(s)
- O A Buneeva
- Institute of Biomedical Chemistry, Moscow, Russia
| | | | | | | | - V G Zgoda
- Institute of Biomedical Chemistry, Moscow, Russia
| | - A E Medvedev
- Institute of Biomedical Chemistry, Moscow, Russia
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2
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Haraux F, Lombès A. Kinetic analysis of ATP hydrolysis by complex V in four murine tissues: Towards an assay suitable for clinical diagnosis. PLoS One 2019; 14:e0221886. [PMID: 31461494 PMCID: PMC6713359 DOI: 10.1371/journal.pone.0221886] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/17/2019] [Indexed: 12/12/2022] Open
Abstract
Background ATP synthase, the mitochondrial complex V, plays a major role in bioenergetics and its defects lead to severe diseases. Lack of a consensual protocol for the assay of complex V activity probably explains the under-representation of complex V defect among mitochondrial diseases. The aim of this work was to elaborate a fast, simple and reliable method to check the maximal complex V capacity in samples relevant to clinical diagnosis. Methods Using homogenates from four different murine organs, we tested the use of dodecylmaltoside, stability of the activity, linearity with protein amount, sensitivity to oligomycin and to exogenous inhibitory factor 1 (IF1), influence of freezing, and impact of mitochondrial purification. Results We obtained organ-dependent, reproducible and stable complex V specific activities, similar with fresh and frozen organs. Similar inhibition by oligomycin and exogenous IF1 demonstrated tight coupling between F1 and F0 domains. The Michaelis constant for MgATP had close values for all organs, in the 150–220 μM range. Complex V catalytic turnover rate, as measured in preparations solubilized in detergent using immunotitration and activity measurements, was more than three times higher in extracts from brain or muscle than in extracts from heart or liver. This tissue specificity suggested post-translational modifications. Concomitant measurement of respiratory activities showed only slightly different complex II/complex V ratio in the four organs. In contrast, complex I/complex V ratio differed in brain as compared to the three other organs because of a high complex I activity in brain. Mitochondria purification preserved these ratios, except for brain where selective degradation of complex I occurred. Therefore, mitochondrial purification could introduce a biased enzymatic evaluation. Conclusion Altogether, this work demonstrates that a reliable assay of complex V activity is perfectly possible with very small samples from frozen biopsies, which was confirmed using control and deficient human muscles.
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Affiliation(s)
- Francis Haraux
- Institute for Integrative Biology of the Cell (I2BC), CEA, Gif-sur-Yvette, France.,UMR 9198, CNRS, Gif-sur-Yvette, France.,Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Anne Lombès
- Institut Cochin, Unité U1016, INSERM, Paris, France.,UMR 8104, CNRS, Paris, France.,Université Paris 5, Paris, France
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3
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Fruttero LL, Leyria J, Moyetta NR, Ramos FO, Settembrini BP, Canavoso LE. The Fat Body of the Hematophagous Insect, Panstrongylus megistus (Hemiptera: Reduviidae): Histological Features and Participation of the β-Chain of ATP Synthase in the Lipophorin-Mediated Lipid Transfer. JOURNAL OF INSECT SCIENCE (ONLINE) 2019; 19:5539020. [PMID: 31346627 PMCID: PMC6658809 DOI: 10.1093/jisesa/iez078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Indexed: 05/09/2023]
Abstract
In insects, lipid transfer to the tissues is mediated by lipophorin, the major circulating lipoprotein, mainly through a nonendocytic pathway involving docking receptors. Currently, the role of such receptors in lipid metabolism remains poorly understood. In this work, we performed a histological characterization of the fat body of the Chagas' disease vector, Panstrongylus megistus (Burmeister), subjected to different nutritional conditions. In addition, we addressed the role of the β-chain of ATP synthase (β-ATPase) in the process of lipid transfer from lipophorin to the fat body. Fifth-instar nymphs in either fasting or fed condition were employed in the assays. Histological examination revealed that the fat body was composed by diverse trophocyte phenotypes. In the fasting condition, the cells were smaller and presented a homogeneous cytoplasmic content. The fat body of fed insects increased in size mainly due to the enlargement of lipid stores. In this condition, trophocytes contained abundant lipid droplets, and the rough endoplasmic reticulum was highly developed and mitochondria appeared elongated. Immunofluorescence assays showed that the β-ATPase, a putative lipophorin receptor, was located on the surface of fat body cells colocalizing partially with lipophorin, which suggests their interaction. No changes in β-ATPase expression were found in fasting and fed insects. Blocking the lipophorin-β-ATPase interaction impaired the lipophorin-mediated lipid transfer to the fat body. The results showed that the nutritional status of the insect influenced the morphohistological features of the tissue. Besides, these findings suggest that β-ATPase functions as a lipophorin docking receptor in the fat body.
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Affiliation(s)
- Leonardo L Fruttero
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Jimena Leyria
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Natalia R Moyetta
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Fabian O Ramos
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Beatriz P Settembrini
- Museo Argentino de Ciencias Naturales Bernardino Rivadavia (CONICET), Buenos Aires, Argentina
| | - Lilián E Canavoso
- Departamento de Bioquímica Clínica, Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Corresponding author, e-mail:
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4
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Pečnerová P, Palkopoulou E, Wheat CW, Skoglund P, Vartanyan S, Tikhonov A, Nikolskiy P, van der Plicht J, Díez-Del-Molino D, Dalén L. Mitogenome evolution in the last surviving woolly mammoth population reveals neutral and functional consequences of small population size. Evol Lett 2017; 1:292-303. [PMID: 30283657 PMCID: PMC6121868 DOI: 10.1002/evl3.33] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/06/2017] [Indexed: 01/25/2023] Open
Abstract
The onset of the Holocene was associated with a global temperature increase, which led to a rise in sea levels and isolation of the last surviving population of woolly mammoths on Wrangel Island. Understanding what happened with the population's genetic diversity at the time of the isolation and during the ensuing 6000 years can help clarify the effects of bottlenecks and subsequent limited population sizes in species approaching extinction. Previous genetic studies have highlighted questions about how the Holocene Wrangel population was established and how the isolation event affected genetic diversity. Here, we generated high‐quality mitogenomes from 21 radiocarbon‐dated woolly mammoths to compare the ancestral large and genetically diverse Late Pleistocene Siberian population and the small Holocene Wrangel population. Our results indicate that mitogenome diversity was reduced to one single haplotype at the time of the isolation, and thus that the Holocene Wrangel Island population was established by a single maternal lineage. Moreover, we show that the ensuing small effective population size coincided with fixation of a nonsynonymous mutation, and a comparative analysis of mutation rates suggests that the evolutionary rate was accelerated in the Holocene population. These results suggest that isolation on Wrangel Island led to an increase in the frequency of deleterious genetic variation, and thus are consistent with the hypothesis that strong genetic drift in small populations leads to purifying selection being less effective in removing deleterious mutations.
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Affiliation(s)
- Patrícia Pečnerová
- Department of Bioinformatics and Genetics Swedish Museum of Natural History Stockholm Sweden.,Department of Zoology Stockholm University Stockholm Sweden
| | - Eleftheria Palkopoulou
- Department of Bioinformatics and Genetics Swedish Museum of Natural History Stockholm Sweden.,Department of Zoology Stockholm University Stockholm Sweden.,Department of Genetics Harvard Medical School Boston Massachusetts 02115
| | | | - Pontus Skoglund
- Department of Genetics Harvard Medical School Boston Massachusetts 02115.,Broad Institute of Harvard and MIT Cambridge Massachusetts 02142
| | - Sergey Vartanyan
- North-East Interdisciplinary Scientific Research Institute N.A.N.A. Shilo Far East Branch, Russian Academy of Sciences (NEISRI FEB RAS) Magadan Russia
| | - Alexei Tikhonov
- Zoological Institute of Russian Academy of Sciences Saint-Petersburg Russia.,Institute of Applied Ecology of the North North-Eastern Federal University Yakutsk Russia
| | - Pavel Nikolskiy
- Geological Institute of the Russian Academy of Sciences Moscow Russia
| | - Johannes van der Plicht
- Centre for Isotope Research Groningen University Groningen The Netherlands.,Faculty of Archaeology Leiden University Leiden The Netherlands
| | - David Díez-Del-Molino
- Department of Bioinformatics and Genetics Swedish Museum of Natural History Stockholm Sweden
| | - Love Dalén
- Department of Bioinformatics and Genetics Swedish Museum of Natural History Stockholm Sweden
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5
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Nazari M, Serrill JD, Wan X, Nguyen MH, Anklin C, Gallegos DA, Smith AB, Ishmael JE, McPhail KL. New Mandelalides Expand a Macrolide Series of Mitochondrial Inhibitors. J Med Chem 2017; 60:7850-7862. [PMID: 28841379 DOI: 10.1021/acs.jmedchem.7b00990] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Mandelalides A-D (1-4) are macrocyclic polyketides known to have an unusual bioactivity profile influenced by compound glycosylation and growth phase of cultured cells. The isolation and characterization of additional natural congeners, mandelalides E-L (5-12), and the supply of synthetic compounds 1 and 12, as well as seco-mandelalide A methyl ester (13), have now facilitated mechanism of action and structure-activity relationship studies. Glycosylated mandelalides are effective inhibitors of aerobic respiration in living cells. Macrolides 1 and 2 inhibit mitochondrial function similar to oligomycin A and apoptolidin A, selective inhibitors of the mammalian ATP synthase (complex V). 1 inhibits ATP synthase activity from isolated mitochondria and triggers caspase-dependent apoptosis in HeLa cells, which are more sensitive to inhibition by 1 in the presence of the glycolysis inhibitor 2-deoxyglucose. Thus, mandelalide cytotoxicity depends on basal metabolic phenotype; cells with an oxidative phenotype are most likely to be inhibited by the mandelalides.
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Affiliation(s)
- Mohamad Nazari
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | - Jeffrey D Serrill
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | - Xuemei Wan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | - Minh H Nguyen
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States
| | - Clemens Anklin
- Bruker BioSpin , 15 Fortune Drive, Billerica, Massachusetts 01821, United States
| | - David A Gallegos
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States
| | - Jane E Ishmael
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
| | - Kerry L McPhail
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Corvallis, Oregon 97331, United States
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6
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Boedeker C, Schüler M, Reintjes G, Jeske O, van Teeseling MCF, Jogler M, Rast P, Borchert D, Devos DP, Kucklick M, Schaffer M, Kolter R, van Niftrik L, Engelmann S, Amann R, Rohde M, Engelhardt H, Jogler C. Determining the bacterial cell biology of Planctomycetes. Nat Commun 2017; 8:14853. [PMID: 28393831 PMCID: PMC5394234 DOI: 10.1038/ncomms14853] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 02/07/2017] [Indexed: 02/08/2023] Open
Abstract
Bacteria of the phylum Planctomycetes have been previously reported to possess several features that are typical of eukaryotes, such as cytosolic compartmentalization and endocytosis-like macromolecule uptake. However, recent evidence points towards a Gram-negative cell plan for Planctomycetes, although in-depth experimental analysis has been hampered by insufficient genetic tools. Here we develop methods for expression of fluorescent proteins and for gene deletion in a model planctomycete, Planctopirus limnophila, to analyse its cell organization in detail. Super-resolution light microscopy of mutants, cryo-electron tomography, bioinformatic predictions and proteomic analyses support an altered Gram-negative cell plan for Planctomycetes, including a defined outer membrane, a periplasmic space that can be greatly enlarged and convoluted, and an energized cytoplasmic membrane. These conclusions are further supported by experiments performed with two other Planctomycetes, Gemmata obscuriglobus and Rhodopirellula baltica. We also provide experimental evidence that is inconsistent with endocytosis-like macromolecule uptake; instead, extracellular macromolecules can be taken up and accumulate in the periplasmic space through unclear mechanisms.
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Affiliation(s)
| | - Margarete Schüler
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Greta Reintjes
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Olga Jeske
- Leibniz Institute DSMZ, Inhoffenstraße 7b, 38124 Braunschweig, Germany
| | - Muriel C. F. van Teeseling
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
- Department of Cellular Microbiology, Philipps-University Marburg, Faculty of Biology, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Mareike Jogler
- Leibniz Institute DSMZ, Inhoffenstraße 7b, 38124 Braunschweig, Germany
| | - Patrick Rast
- Leibniz Institute DSMZ, Inhoffenstraße 7b, 38124 Braunschweig, Germany
| | - Daniela Borchert
- Leibniz Institute DSMZ, Inhoffenstraße 7b, 38124 Braunschweig, Germany
| | - Damien P. Devos
- Department of Cell biology and Biotechnology, CABD, Pablo de Olavide University-CSIC, Carretera de Utrera km1, 41013 Sevilla, Spain
| | - Martin Kucklick
- Helmholtz Center for Infection Research GmbH, Inhoffenstraße 7, 38124 Braunschweig, Germany
- Department of Microbial Proteomics, Technical University Braunschweig, Institute for Microbiology, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Roberto Kolter
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Laura van Niftrik
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
| | - Susanne Engelmann
- Helmholtz Center for Infection Research GmbH, Inhoffenstraße 7, 38124 Braunschweig, Germany
- Department of Microbial Proteomics, Technical University Braunschweig, Institute for Microbiology, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Rudolf Amann
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Manfred Rohde
- Helmholtz Center for Infection Research GmbH, Inhoffenstraße 7, 38124 Braunschweig, Germany
| | - Harald Engelhardt
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Christian Jogler
- Leibniz Institute DSMZ, Inhoffenstraße 7b, 38124 Braunschweig, Germany
- Department of Microbiology, Radboud University, Heyendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
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7
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Ferreira MAR, Jansen R, Willemsen G, Penninx B, Bain LM, Vicente CT, Revez JA, Matheson MC, Hui J, Tung JY, Baltic S, Le Souëf P, Montgomery GW, Martin NG, Robertson CF, James A, Thompson PJ, Boomsma DI, Hopper JL, Hinds DA, Werder RB, Phipps S. Gene-based analysis of regulatory variants identifies 4 putative novel asthma risk genes related to nucleotide synthesis and signaling. J Allergy Clin Immunol 2016; 139:1148-1157. [PMID: 27554816 DOI: 10.1016/j.jaci.2016.07.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND Hundreds of genetic variants are thought to contribute to variation in asthma risk by modulating gene expression. Methods that increase the power of genome-wide association studies (GWASs) to identify risk-associated variants are needed. OBJECTIVE We sought to develop a method that aggregates the evidence for association with disease risk across expression quantitative trait loci (eQTLs) of a gene and use this approach to identify asthma risk genes. METHODS We developed a gene-based test and software package called EUGENE that (1) is applicable to GWAS summary statistics; (2) considers both cis- and trans-eQTLs; (3) incorporates eQTLs identified in different tissues; and (4) uses simulations to account for multiple testing. We applied this approach to 2 published asthma GWASs (combined n = 46,044) and used mouse studies to provide initial functional insights into 2 genes with novel genetic associations. RESULTS We tested the association between asthma and 17,190 genes that were found to have cis- and/or trans-eQTLs across 16 published eQTL studies. At an empirical FDR of 5%, 48 genes were associated with asthma risk. Of these, for 37, the association was driven by eQTLs located in established risk loci for allergic disease, including 6 genes not previously implicated in disease cause (eg, LIMS1, TINF2, and SAFB). The remaining 11 significant genes represent potential novel genetic associations with asthma. The association with 4 of these replicated in an independent GWAS: B4GALT3, USMG5, P2RY13, and P2RY14, which are genes involved in nucleotide synthesis or nucleotide-dependent cell activation. In mouse studies, P2ry13 and P2ry14-purinergic receptors activated by adenosine 5-diphosphate and UDP-sugars, respectively-were upregulated after allergen challenge, notably in airway epithelial cells, eosinophils, and neutrophils. Intranasal exposure with receptor agonists induced the release of IL-33 and subsequent eosinophil infiltration into the lungs. CONCLUSION We identified novel associations between asthma and eQTLs for 4 genes related to nucleotide synthesis/signaling and demonstrated the power of gene-based analyses of GWASs.
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Affiliation(s)
| | - Rick Jansen
- Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
| | - Gonneke Willemsen
- Department of Biological Psychology, Vrije University Amsterdam, Amsterdam, The Netherlands
| | - Brenda Penninx
- Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
| | - Lisa M Bain
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Joana A Revez
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Melanie C Matheson
- Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Jennie Hui
- PathWest Laboratory Medicine of Western Australia, Nedlands, Australia; School of Population Health, University of Western Australia, Nedlands, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Australia; Busselton Population Medical Research Foundation, Sir Charles Gairdner Hospital, Nedlands, Australia
| | | | - Svetlana Baltic
- Institute for Respiratory Health, Harry Perkins Institute of Medical Research, Nedlands, Australia
| | - Peter Le Souëf
- School of Paediatrics and Child Health, Princess Margaret Hospital for Children, Subiaco, Australia
| | | | | | - Colin F Robertson
- Respiratory Medicine, Murdoch Children's Research Institute, Melbourne, Australia
| | - Alan James
- Busselton Population Medical Research Foundation, Sir Charles Gairdner Hospital, Nedlands, Australia; School of Medicine and Pharmacology, University of Western Australia, Nedlands, Australia; Department of Pulmonary Physiology and Sleep Medicine, West Australian Sleep Disorders Research Institute, Nedlands, Australia
| | - Philip J Thompson
- Institute for Respiratory Health, Harry Perkins Institute of Medical Research, Nedlands, Australia; School of Medicine and Pharmacology, University of Western Australia, Nedlands, Australia
| | - Dorret I Boomsma
- Department of Biological Psychology, Vrije University Amsterdam, Amsterdam, The Netherlands
| | - John L Hopper
- Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | | | - Rhiannon B Werder
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Simon Phipps
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
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8
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Fliedner SMJ, Yang C, Thompson E, Abu-Asab M, Hsu CM, Lampert G, Eiden L, Tischler AS, Wesley R, Zhuang Z, Lehnert H, Pacak K. Potential therapeutic target for malignant paragangliomas: ATP synthase on the surface of paraganglioma cells. Am J Cancer Res 2015; 5:1558-1570. [PMID: 26101719 PMCID: PMC4473332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/15/2015] [Indexed: 06/04/2023] Open
Abstract
F1FoATP synthase (ATP synthase) is a ubiquitous enzyme complex in eukaryotes. In general it is localized to the mitochondrial inner membrane and serves as the last step in the mitochondrial oxidative phosphorylation of ADP to ATP, utilizing a proton gradient across the inner mitochondrial membrane built by the complexes of the electron transfer chain. However some cell types, including tumors, carry ATP synthase on the cell surface. It was suggested that cell surface ATP synthase helps tumor cells thriving on glycolysis to survive their high acid generation. Angiostatin, aurovertin, resveratrol, and antibodies against the α and β subunits of ATP synthase were shown to bind and selectively inhibit cell surface ATP synthase, promoting tumor cell death. Here we show that ATP synthase β (ATP5B) is present on the cell surface of mouse pheochromocytoma cells as well as tumor cells of human SDHB-derived paragangliomas (PGLs), while being virtually absent on chromaffin primary cells from bovine adrenal medulla by confocal microscopy. The cell surface location of ATP5B was verified in the tissue of an SDHB-derived PGL by immunoelectron microscopy. Treatment of mouse pheochromocytoma cells with resveratrol as well as ATP5B antibody led to statistically significant proliferation inhibition. Our data suggest that PGLs carry ATP synthase on their surface that promotes cell survival or proliferation. Thus, cell surface ATP synthase may present a novel therapeutic target in treating metastatic or inoperable PGLs.
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Affiliation(s)
- Stephanie MJ Fliedner
- Program on Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesda, MD 20892, USA
- 1 Department of Medicine, University Medical Center Schleswig-Holstein, Campus LübeckRatzeburger Allee 160, 23538 Lübeck, Germany
| | - Chunzhang Yang
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesda, MD 20892, USA
| | - Eli Thompson
- Program on Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesda, MD 20892, USA
| | - Mones Abu-Asab
- Section of Immunopathology, National Eye Institute, NIH, National Institutes of HealthBethesda, MD 20892, USA
| | - Chang-Mei Hsu
- Section on Molecular Neuroscience, National Institute of Mental Health, National Institutes of HealthBethesda, Maryland 20892, USA
| | | | - Lee Eiden
- Section on Molecular Neuroscience, National Institute of Mental Health, National Institutes of HealthBethesda, Maryland 20892, USA
| | - Arthur S Tischler
- Department of Pathology and Laboratory Medicine, Tufts Medical CenterBoston, MA 02111, USA
| | - Robert Wesley
- Department of Health and Human Services, Clinical Center, National Institutes of HealthBethesda, MD 20892, USA
| | - Zhengping Zhuang
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesda, MD 20892, USA
| | - Hendrik Lehnert
- 1 Department of Medicine, University Medical Center Schleswig-Holstein, Campus LübeckRatzeburger Allee 160, 23538 Lübeck, Germany
| | - Karel Pacak
- Program on Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesda, MD 20892, USA
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9
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Antoniel M, Giorgio V, Fogolari F, Glick GD, Bernardi P, Lippe G. The oligomycin-sensitivity conferring protein of mitochondrial ATP synthase: emerging new roles in mitochondrial pathophysiology. Int J Mol Sci 2014; 15:7513-36. [PMID: 24786291 PMCID: PMC4057687 DOI: 10.3390/ijms15057513] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 04/18/2014] [Accepted: 04/21/2014] [Indexed: 01/08/2023] Open
Abstract
The oligomycin-sensitivity conferring protein (OSCP) of the mitochondrial F(O)F1 ATP synthase has long been recognized to be essential for the coupling of proton transport to ATP synthesis. Located on top of the catalytic F1 sector, it makes stable contacts with both F1 and the peripheral stalk, ensuring the structural and functional coupling between F(O) and F1, which is disrupted by the antibiotic, oligomycin. Recent data have established that OSCP is the binding target of cyclophilin (CyP) D, a well-characterized inducer of the mitochondrial permeability transition pore (PTP), whose opening can precipitate cell death. CyPD binding affects ATP synthase activity, and most importantly, it decreases the threshold matrix Ca²⁺ required for PTP opening, in striking analogy with benzodiazepine 423, an apoptosis-inducing agent that also binds OSCP. These findings are consistent with the demonstration that dimers of ATP synthase generate Ca²⁺-dependent currents with features indistinguishable from those of the PTP and suggest that ATP synthase is directly involved in PTP formation, although the underlying mechanism remains to be established. In this scenario, OSCP appears to play a fundamental role, sensing the signal(s) that switches the enzyme of life in a channel able to precipitate cell death.
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Affiliation(s)
- Manuela Antoniel
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/B, 35121 Padua, Italy.
| | - Valentina Giorgio
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/B, 35121 Padua, Italy.
| | - Federico Fogolari
- Department of Biomedical Sciences, University of Udine, p.le Kolbe, 33100 Udine, Italy.
| | - Gary D Glick
- Department of Chemistry, Graduate Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/B, 35121 Padua, Italy.
| | - Giovanna Lippe
- Department of Food Science, University of Udine, via Sondrio 2/A, 33100 Udine, Italy.
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10
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Srisen K, Röhrl C, Meisslitzer-Ruppitsch C, Ranftler C, Ellinger A, Pavelka M, Neumüller J. Human endothelial progenitor cells internalize high-density lipoprotein. PLoS One 2013; 8:e83189. [PMID: 24386159 PMCID: PMC3875452 DOI: 10.1371/journal.pone.0083189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/10/2013] [Indexed: 12/15/2022] Open
Abstract
Endothelial progenitor cells (EPCs) originate either directly from hematopoietic stem cells or from a subpopulation of monocytes. Controversial views about intracellular lipid traffic prompted us to analyze the uptake of human high density lipoprotein (HDL), and HDL-cholesterol in human monocytic EPCs. Fluorescence and electron microscopy were used to investigate distribution and intracellular trafficking of HDL and its associated cholesterol using fluorescent surrogates (bodipy-cholesterol and bodipy-cholesteryl oleate), cytochemical labels and fluorochromes including horseradish peroxidase and Alexa Fluor® 568. Uptake and intracellular transport of HDL were demonstrated after internalization periods from 0.5 to 4 hours. In case of HDL-Alexa Fluor® 568, bodipy-cholesterol and bodipy-cholesteryl oleate, a photooxidation method was carried out. HDL-specific reaction products were present in invaginations of the plasma membrane at each time of treatment within endocytic vesicles, in multivesicular bodies and at longer periods of uptake, also in lysosomes. Some HDL-positive endosomes were arranged in form of "strings of pearl"- like structures. HDL-positive multivesicular bodies exhibited intensive staining of limiting and vesicular membranes. Multivesicular bodies of HDL-Alexa Fluor® 568-treated EPCs showed multilamellar intra-vacuolar membranes. At all periods of treatment, labeled endocytic vesicles and organelles were apparent close to the cell surface and in perinuclear areas around the Golgi apparatus. No HDL-related particles could be demonstrated close to its cisterns. Electron tomographic reconstructions showed an accumulation of HDL-containing endosomes close to the trans-Golgi-network. HDL-derived bodipy-cholesterol was localized in endosomal vesicles, multivesicular bodies, lysosomes and in many of the stacked Golgi cisternae and the trans-Golgi-network Internalized HDL-derived bodipy-cholesteryl oleate was channeled into the lysosomal intraellular pathway and accumulated prominently in all parts of the Golgi apparatus and in lipid droplets. Subsequently, also the RER and mitochondria were involved. These studies demonstrated the different intracellular pathway of HDL-derived bodipy-cholesterol and HDL-derived bodipy-cholesteryl oleate by EPCs, with concomitant.
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Affiliation(s)
- Kaemisa Srisen
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
| | - Clemens Röhrl
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Claudia Meisslitzer-Ruppitsch
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
| | - Carmen Ranftler
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
| | - Adolf Ellinger
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
| | - Margit Pavelka
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
| | - Josef Neumüller
- Center for Anatomy and Cell Biology, Department of Cell Biology and Ultrastructure Research, Medical University of Vienna, Vienna, Austria
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11
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Genoux A, Ruidavets JB, Ferrières J, Combes G, Lichtenstein L, Pons V, Laffargue M, Taraszkiewicz D, Carrié D, Elbaz M, Perret B, Martinez LO. Serum IF1 concentration is independently associated to HDL levels and to coronary heart disease: the GENES study. J Lipid Res 2013; 54:2550-8. [PMID: 23794714 PMCID: PMC3735951 DOI: 10.1194/jlr.p036335] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 06/21/2013] [Indexed: 11/20/2022] Open
Abstract
HDL is strongly inversely related to cardiovascular risk. Hepatic HDL uptake is controlled by ecto-F1-ATPase activity, and potentially inhibited by mitochondrial inhibitor factor 1 (IF1). We recently found that IF1 is present in serum and correlates with HDL-cholesterol (HDL-C). Here, we have evaluated the relationship between circulating IF1 and plasma lipoproteins, and we determined whether IF1 concentration is associated with the risk of coronary heart disease (CHD). Serum IF1 was measured in 648 coronary patients ages 45-74 and in 669 matched male controls, in the context of a cross-sectional study on CHD. Cardiovascular risk factors were documented for each participant, including life-style habits and biological and clinical markers. In controls, multivariate analysis demonstrated that IF1 was independently positively associated with HDL-C and apoA-I (r = 0.27 and 0.28, respectively, P < 0.001) and negatively with triglycerides (r = -0.23, P < 0.001). Mean IF1 concentration was lower in CHD patients than in controls (0.43 mg/l and 0.53 mg/l, respectively, P < 0.001). In multivariate analyses, following adjustments on cardiovascular risk factors or markers, IF1 was negatively related to CHD (P < 0.001). This relationship was maintained after adjustment for HDL-C or apoA-I. This study identifies IF1 as a new determinant of HDL-C that is inversely associated with CHD.
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Affiliation(s)
- Annelise Genoux
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
- Service de Biochimie, Pôle biologie, hôpital de Purpan, CHU de Toulouse, Toulouse, 31000, France
| | | | - Jean Ferrières
- INSERM, U1027, Faculté de Médecine, Toulouse, 31073, France
- Service de Cardiologie, Pôle cardiovasculaire et métabolique, hôpital de Rangueil, CHU de Toulouse, Toulouse, 31000, France
| | - Guillaume Combes
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
| | - Laeticia Lichtenstein
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
| | - Véronique Pons
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
| | - Muriel Laffargue
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
| | | | - Didier Carrié
- Service de Cardiologie, Pôle cardiovasculaire et métabolique, hôpital de Rangueil, CHU de Toulouse, Toulouse, 31000, France
| | - Meyer Elbaz
- Service de Cardiologie, Pôle cardiovasculaire et métabolique, hôpital de Rangueil, CHU de Toulouse, Toulouse, 31000, France
| | - Bertrand Perret
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
- Service de Biochimie, Pôle biologie, hôpital de Purpan, CHU de Toulouse, Toulouse, 31000, France
| | - Laurent O. Martinez
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, 31000, France
- Université de Toulouse III, UMR1048, Toulouse, 31300, France
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12
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Ectopic F0F 1 ATP synthase contains both nuclear and mitochondrially-encoded subunits. J Bioenerg Biomembr 2013; 45:569-79. [PMID: 23943123 DOI: 10.1007/s10863-013-9522-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/14/2013] [Indexed: 12/11/2022]
Abstract
Over the past few years, several reports have described the presence of F0F1 ATP synthase subunits at the surface of hepatocytes, where the hydrolytic activity of F1 sector faces outside and triggers HDL endocytosis. An intriguing question is whether the ectopic enzyme has same subunit composition and molecular mass as that of the mitochondrial ATP synthase. Also due to the polar nature of hepatocytes, the enzyme may be localized to a particular cell boundary. Using different methods to prepare rat liver plasma membranes, which have been subjected to digitonin extraction, hr CN PAGE, immunoblotting, and mass spectrometry analysis, we demonstrate the presence of ecto-F0F1 complexes which have a similar molecular weight to the monomeric form of the mitochondrial complexes, containing both nuclear and mitochondrially-encoded subunits. This finding makes it unlikely that the enzyme assembles on the plasma membranes, but suggest it to be transported whole after being assembled in mitochondria by still unknown pathways. Moreover, the plasma membrane preparation enriched in basolateral proteins contains much higher amounts of complete and active F0F1 complexes, consistent with their specific function to modulate the HDL uptake on hepatocyte surface.
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13
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Recombinant high density lipoprotein nanoparticles for target-specific delivery of siRNA. Pharm Res 2012; 30:1203-14. [PMID: 23242841 DOI: 10.1007/s11095-012-0957-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 12/06/2012] [Indexed: 12/27/2022]
Abstract
PURPOSE Regulation of gene expression using small interfering RNA (siRNA) is a promising strategy for treatments of numerous diseases. However, the progress towards broad application of siRNA requires the development of safe and effective vectors that target to specific cells. In this study, we developed a novel recombinant high density lipoprotein (rHDL) vector with high siRNA encapsulation efficiency. METHODS They were prepared by condensing siRNA with various commercial cationic polymers and coating the polyplex with a layer of lipids and apolipoprotein AI (apo AI). The rHDL nanoparticles were used to transfect SMMC-7721 hepatoma cells with stable luciferase expression. The uptake and intracellular trafficing of siRNA were also investigated. RESULTS Characterization studies revealed these rHDL nanoparticles had similar physical properties as natural HDLs. The various rHDL formulations had high silencing efficiency (more than 70% knockdown) in hepatocytes with minimum cytotoxicity. Moreover, the uptake of rHDL by SMMC-7721 was confirmed to be mediated through the natural HDL uptake pathway. CONCLUSIONS The work described here demonstrated the optimized rHDL nanoparticles may offer a promising tool for siRNA delivery to the liver.
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14
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Rui M, Guo W, Ding Q, Wei X, Xu J, Xu Y. Recombinant high-density lipoprotein nanoparticles containing gadolinium-labeled cholesterol for morphologic and functional magnetic resonance imaging of the liver. Int J Nanomedicine 2012; 7:3751-68. [PMID: 22888232 PMCID: PMC3414207 DOI: 10.2147/ijn.s33139] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background Natural high-density lipoproteins (HDL) possess important physiological functions to the transport of cholesterol from the peripheral tissues to the liver for metabolic degradation and excretion in the bile. Methods and results In this work, we took advantage of this pathway and prepared two different gadolinium (Gd)-DTPA-labeled cholesterol-containing recombinant HDL nanoparticles (Gd-chol-HDL) and Gd-(chol)2-HDL as liver-specific magnetic resonance imaging (MRI) contrast agents. The reconstituted HDL nanoparticles had structural similarity to native HDL, and could be taken up by HepG2 cells via interaction with HDL receptors in vitro. In vivo MRI studies in rats after intravenous injections of 10 μmol gadolinium per kg of recombinant HDL nanoparticles indicated that both nanoparticles could provide signal enhancement in the liver and related organs. However, different T1-weighted image details suggested that they participated in different cholesterol metabolism and excretion pathways in the liver. Conclusion Such information could be highly useful to differentiate functional changes as well as anatomic differences in the liver. These cholesterol-derived contrast agents and their recombinant HDL preparations may warrant further development as a new class of contrast agents for MRI of the liver and related organs.
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Affiliation(s)
- Mengjie Rui
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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15
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Deshpande M, Notari L, Subramanian P, Notario V, Becerra SP. Inhibition of tumor cell surface ATP synthesis by pigment epithelium-derived factor: implications for antitumor activity. Int J Oncol 2012; 41:219-27. [PMID: 22504705 DOI: 10.3892/ijo.2012.1431] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Accepted: 01/09/2012] [Indexed: 11/06/2022] Open
Abstract
Recently, we have shown that the antiangiogenic pigment epithelium-derived factor (PEDF) can bind the catalytic β-subunit of F1-ATP synthase and inhibit endothelial cell surface ATP synthase activity. This factor can additionally restrict tumor growth, invasion and metastasis, and can directly induce death on several tumor cell types. Active cell surface ATP synthase is also present in certain tumor cells and its ATP product is considered a stimulus for tumor growth. The present study aimed to elucidate the biological implications of the interactions between the extracellular PEDF and tumor cell surface ATP synthase. Incubation of T24 human urinary bladder carcinoma cells in media containing human recombinant PEDF protein for 48-96 h dramatically decreased cell viability in a concentration-dependent fashion as monitored by real-time cell impedance with a microelectronic system, microscopic imaging and biomarkers of live cells. Intact tumor cells exhibited cell surface ATP synthesis activity, which was inhibited by piceatannol, a specific inhibitor of F1/F0-ATP synthase. Immunoblotting revealed that the β subunit of F1-ATP synthase was present in plasma membrane fractions of these cells. Interestingly, pre-incubation of tumor cells with PEDF inhibited the activity of cell surface ATP synthase in a concentration-dependent fashion. The PEDF-derived peptide 34-mer decreased tumor cell viability and inhibited extracellular ATP synthesis to the same extent as full-length PEDF. Moreover, ATP additions attenuated both the PEDF-mediated decrease in tumor cell viability and the inhibition of endothelial cell tube formation. The results lead to conclude that PEDF is a novel inhibitor of tumor cell surface ATP synthase activity that exhibits a cytotoxic effect on tumor cells, and that the structural determinants for these properties are within the peptide region 34-mer of the PEDF polypeptide. The data strongly suggest a role for the interaction between the 34-mer region of PEDF and tumor cell-surface ATP synthase in promoting tumor cell death.
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Affiliation(s)
- Monika Deshpande
- Section of Protein Structure and Function, Laboratory of Retinal Cell and Molecular Biology, NEI-NIH, Bethesda, MD, USA
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16
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Abstract
The WHO classification of endocrine tumors defines pheochromocytoma as a tumor arising from chromaffin cells in the adrenal medulla - an intra-adrenal paraganglioma. Closely related tumors of extra-adrenal sympathetic and parasympathetic paraganglia are classified as extra-adrenal paragangliomas. Almost all pheochromocytomas and paragangliomas produce catecholamines. The concentrations of catecholamines in pheochromocytoma tissues are enormous, potentially creating a volcano that can erupt at any time. Significant eruptions result in catecholamine storms called "attacks" or "spells". Acute catecholamine crisis can strike unexpectedly, leaving traumatic memories of acute medical disaster that champions any intensive care unit. A very well-defined genotype-biochemical phenotype relationship exists, guiding proper and cost-effective genetic testing of patients with these tumors. Currently, the production of norepinephrine and epinephrine is optimally assessed by the measurement of their O-methylated metabolites, normetanephrine or metanephrine, respectively. Dopamine is a minor component, but some paragangliomas produce only this catecholamine or this together with norepinephrine. Methoxytyramine, the O-methylated metabolite of dopamine, is the best biochemical marker of these tumors. In those patients with equivocal biochemical results, a modified clonidine suppression test coupled with the measurement of plasma normetanephrine has recently been introduced. In addition to differences in catecholamine enzyme expression, the presence of either constitutive or regulated secretory pathways contributes further to the very unique mutation-dependent catecholamine production and release, resulting in various clinical presentations. Oxidative stress results from a significant imbalance between levels of prooxidants, generated during oxidative phosphorylation, and antioxidants. The gradual accumulation of prooxidants due to metabolic oxidative stress results in proto-oncogene activation, tumor suppressor gene inactivation, DNA damage, and genomic instability. Since the mitochondria serves as the main source of prooxidants, any mitochondrial impairment leads to severe oxidative stress, a major outcome of which is tumor development. In terms of cancer pathogenesis, pheochromocytomas and paragangliomas represent tumors where the oxidative phosphorylation defect due to the mutation of succinate dehydrogenase is the cause, not a consequence, of tumor development. Any succinate dehydrogenase pathogenic mutation results in the shift from oxidative phosphorylation to aerobic glycolysis in the cytoplasm (also called anaerobic glycolysis if hypoxia is the main cause of such a shift). This phenomenon, also called the Warburg effect, is well demonstrated by a positive [18F]-fluorodeoxyglycose positron emission tomography scan. Microarray studies, genome-wide association studies, proteomics and protein arrays, metabolomics, transcriptomics, and bioinformatics approaches will remain powerful tools to further uncover the pathogenesis of these tumors and their unique markers, with the ultimate goal to introduce new therapeutic options for those with metastatic or malignant pheochromocytoma and paraganglioma. Soon oxidative stress will be tightly linked to a multistep cancer process in which the mutation of various genes (perhaps in a logistic way) ultimately results in uncontrolled growth, proliferation, and metastatic potential of practically any cell. Targeting the mTORC, IGF-1, HIF and other pathways, topoisomerases, protein degradation by proteosomes, balancing the activity of protein kinases and phosphatases or even synchronizing the cell cycle before any exposure to any kind of therapy will soon become a reality. Facing such a reality today will favor our chances to "beat" this disease tomorrow.
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Affiliation(s)
- K Pacak
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892, USA.
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17
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Genoux A, Pons V, Radojkovic C, Roux-Dalvai F, Combes G, Rolland C, Malet N, Monsarrat B, Lopez F, Ruidavets JB, Perret B, Martinez LO. Mitochondrial inhibitory factor 1 (IF1) is present in human serum and is positively correlated with HDL-cholesterol. PLoS One 2011; 6:e23949. [PMID: 21935367 PMCID: PMC3173369 DOI: 10.1371/journal.pone.0023949] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 07/28/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mitochondrial ATP synthase is expressed as a plasma membrane receptor for apolipoprotein A-I (apoA-I), the major protein component in High Density Lipoproteins (HDL). On hepatocytes, apoA-I binds to cell surface ATP synthase (namely ecto-F(1)-ATPase) and stimulates its ATPase activity, generating extracellular ADP. This production of extracellular ADP activates a P2Y(13)-mediated HDL endocytosis pathway. Conversely, exogenous IF1, classically known as a natural mitochondrial specific inhibitor of F(1)-ATPase activity, inhibits ecto-F(1)-ATPase activity and decreases HDL endocytosis by both human hepatocytes and perfused rat liver. METHODOLOGY/PRINCIPAL FINDINGS Since recent reports also described the presence of IF1 at the plasma membrane of different cell types, we investigated whether IF1 is present in the systemic circulation in humans. We first unambiguously detected IF1 in human serum by immunoprecipitation and mass spectrometry. We then set up a competitive ELISA assay in order to quantify its level in human serum. Analyses of IF1 levels in 100 normolipemic male subjects evidenced a normal distribution, with a median value of 0.49 µg/mL and a 95% confidence interval of 0.22-0.82 µg/mL. Correlations between IF1 levels and serum lipid levels demonstrated that serum IF1 levels are positively correlated with HDL-cholesterol and negatively with triglycerides (TG). CONCLUSIONS/SIGNIFICANCE Altogether, these data support the view that, in humans, circulating IF1 might affect HDL levels by inhibiting hepatic HDL uptake and also impact TG metabolism.
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Affiliation(s)
- Annelise Genoux
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Toulouse, France
| | - Véronique Pons
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | - Claudia Radojkovic
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | - Florence Roux-Dalvai
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
| | - Guillaume Combes
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | - Corinne Rolland
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | - Nicole Malet
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | - Bernard Monsarrat
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
| | - Frédéric Lopez
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
| | | | - Bertrand Perret
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Toulouse, France
| | - Laurent O. Martinez
- INSERM, UMR1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France
- Université de Toulouse, UPS, Toulouse, France
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18
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Abstract
Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.
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