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Radkohl A, Schusterbauer V, Bernauer L, Rechberger GN, Wolinski H, Schittmayer M, Birner-Gruenberger R, Thallinger GG, Leitner E, Baeck M, Pichler H, Emmerstorfer-Augustin A. Human Sterols Are Overproduced, Stored and Excreted in Yeasts. Int J Mol Sci 2024; 25:781. [PMID: 38255855 PMCID: PMC10815178 DOI: 10.3390/ijms25020781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Sterols exert a profound influence on numerous cellular processes, playing a crucial role in both health and disease. However, comprehending the effects of sterol dysfunction on cellular physiology is challenging. Consequently, numerous processes affected by impaired sterol biosynthesis still elude our complete understanding. In this study, we made use of yeast strains that produce cholesterol instead of ergosterol and investigated the cellular response mechanisms on the transcriptome as well as the lipid level. The exchange of ergosterol for cholesterol caused the downregulation of phosphatidylethanolamine and phosphatidylserine and upregulation of phosphatidylinositol and phosphatidylcholine biosynthesis. Additionally, a shift towards polyunsaturated fatty acids was observed. While the sphingolipid levels dropped, the total amounts of sterols and triacylglycerol increased, which resulted in 1.7-fold enlarged lipid droplets in cholesterol-producing yeast cells. In addition to internal storage, cholesterol and its precursors were excreted into the culture supernatant, most likely by the action of ABC transporters Snq2, Pdr12 and Pdr15. Overall, our results demonstrate that, similarly to mammalian cells, the production of non-native sterols and sterol precursors causes lipotoxicity in K. phaffii, mainly due to upregulated sterol biosynthesis, and they highlight the different survival and stress response mechanisms on multiple, integrative levels.
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Affiliation(s)
- Astrid Radkohl
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Veronika Schusterbauer
- Bisy GmbH, 8200 Hofstaetten an der Raab, Austria
- Institute of Biomedical Informatics, Graz University of Technology, 8010 Graz, Austria
| | - Lukas Bernauer
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Gerald N. Rechberger
- Department of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Heimo Wolinski
- Department of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
| | - Matthias Schittmayer
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, 1040 Vienna, Austria (R.B.-G.)
| | - Ruth Birner-Gruenberger
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, 1040 Vienna, Austria (R.B.-G.)
| | - Gerhard G. Thallinger
- Institute of Biomedical Informatics, Graz University of Technology, 8010 Graz, Austria
| | - Erich Leitner
- Institute of Analytical Chemistry and Food Chemistry, University of Graz, NAWI Graz, 8010 Graz, Austria;
| | - Melanie Baeck
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Harald Pichler
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Acib—Austrian Centre of Industrial Biotechnology, 8010 Graz, Austria
| | - Anita Emmerstorfer-Augustin
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Acib—Austrian Centre of Industrial Biotechnology, 8010 Graz, Austria
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2
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Chalhoub G, Jamnik A, Pajed L, Kolleritsch S, Hois V, Bagaric A, Prem D, Tilp A, Kolb D, Wolinski H, Taschler U, Züllig T, Rechberger GN, Fuchs C, Trauner M, Schoiswohl G, Haemmerle G. Carboxylesterase 2a deletion provokes hepatic steatosis and insulin resistance in mice involving impaired diacylglycerol and lysophosphatidylcholine catabolism. Mol Metab 2023; 72:101725. [PMID: 37059417 PMCID: PMC10148186 DOI: 10.1016/j.molmet.2023.101725] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/04/2023] [Accepted: 04/08/2023] [Indexed: 04/16/2023] Open
Abstract
OBJECTIVE Hepatic triacylglycerol accumulation and insulin resistance are key features of NAFLD. However, NAFLD development and progression are rather triggered by the aberrant generation of lipid metabolites and signaling molecules including diacylglycerol (DAG) and lysophosphatidylcholine (lysoPC). Recent studies showed decreased expression of carboxylesterase 2 (CES2) in the liver of NASH patients and hepatic DAG accumulation was linked to low CES2 activity in obese individuals. The mouse genome encodes several Ces2 genes with Ces2a showing highest expression in the liver. Herein we investigated the role of mouse Ces2a and human CES2 in lipid metabolism in vivo and in vitro. METHODS Lipid metabolism and insulin signaling were investigated in mice lacking Ces2a and in a human liver cell line upon pharmacological CES2 inhibition. Lipid hydrolytic activities were determined in vivo and from recombinant proteins. RESULTS Ces2a deficient mice (Ces2a-ko) are obese and feeding a high-fat diet (HFD) provokes severe hepatic steatosis and insulin resistance together with elevated inflammatory and fibrotic gene expression. Lipidomic analysis revealed a marked rise in DAG and lysoPC levels in the liver of Ces2a-ko mice fed HFD. Hepatic lipid accumulation in Ces2a deficiency is linked to lower DAG and lysoPC hydrolytic activities in liver microsomal preparations. Moreover, Ces2a deficiency significantly increases hepatic expression and activity of MGAT1, a PPAR gamma target gene, suggesting aberrant lipid signaling upon Ces2a deficiency. Mechanistically, we found that recombinant Ces2a and CES2 show significant hydrolytic activity towards lysoPC (and DAG) and pharmacological inhibition of CES2 in human HepG2 cells largely phenocopies the lipid metabolic changes present in Ces2a-ko mice including reduced lysoPC and DAG hydrolysis, DAG accumulation and impaired insulin signaling. CONCLUSIONS Ces2a and CES2 are critical players in hepatic lipid signaling likely via the hydrolysis of DAG and lysoPC at the ER.
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Affiliation(s)
- Gabriel Chalhoub
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Alina Jamnik
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Victoria Hois
- Division of Endocrinology and Diabetology, Medical University of Graz, Austria
| | - Antonia Bagaric
- Department of Pharmacology and Toxicology, University of Graz, Graz, Austria
| | - Dominik Prem
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anna Tilp
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Dagmar Kolb
- Core Facility Ultrastructure Analysis, Medical University of Graz, Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ulrike Taschler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Thomas Züllig
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Claudia Fuchs
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Gabriele Schoiswohl
- Department of Pharmacology and Toxicology, University of Graz, Graz, Austria.
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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3
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Piller P, Semeraro EF, Rechberger GN, Keller S, Pabst G. Allosteric modulation of integral protein activity by differential stress in asymmetric membranes. PNAS Nexus 2023; 2:pgad126. [PMID: 37143864 PMCID: PMC10153742 DOI: 10.1093/pnasnexus/pgad126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/07/2023] [Accepted: 04/06/2023] [Indexed: 05/06/2023]
Abstract
The activity of integral membrane proteins is tightly coupled to the properties of the surrounding lipid matrix. In particular, transbilayer asymmetry, a hallmark of all plasma membranes, might be exploited to control membrane-protein activity. Here, we hypothesized that the membrane-embedded enzyme outer membrane phospholipase A (OmpLA) is susceptible to the lateral pressure differences that build up between such asymmetric membrane leaflets. Upon reconstituting OmpLA into synthetic, chemically well-defined phospholipid bilayers exhibiting different lateral pressure profiles, we indeed observed a substantial decrease in the enzyme's hydrolytic activity with increasing membrane asymmetry. No such effects were observed in symmetric mixtures of the same lipids. To quantitatively rationalize how the differential stress in asymmetric lipid bilayers inhibits OmpLA, we developed a simple allosteric model within the lateral pressure framework. Thus, we find that membrane asymmetry can serve as the dominant factor in controlling membrane-protein activity, even in the absence of specific, chemical cues or other physical membrane determinants such as hydrophobic mismatch.
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Affiliation(s)
- Paulina Piller
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- BioTechMed Graz, Graz 8010, Austria
- Field of Excellence BioHealth—University of Graz, Graz 8010, Austria
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- BioTechMed Graz, Graz 8010, Austria
- Field of Excellence BioHealth—University of Graz, Graz 8010, Austria
| | - Gerald N Rechberger
- Field of Excellence BioHealth—University of Graz, Graz 8010, Austria
- Biochemistry, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Omics Center Graz, BioTechMed Graz, Graz 8010, Austria
| | - Sandro Keller
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- BioTechMed Graz, Graz 8010, Austria
- Field of Excellence BioHealth—University of Graz, Graz 8010, Austria
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4
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Fernandez-Acosta M, Romero JI, Bernabó G, Velázquez-Campos GM, Gonzalez N, Mares ML, Werbajh S, Avendaño-Vázquez LA, Rechberger GN, Kühnlein RP, Marino-Buslje C, Cantera R, Rezaval C, Ceriani MF. orsai, the Drosophila homolog of human ETFRF1, links lipid catabolism to growth control. BMC Biol 2022; 20:233. [PMID: 36266680 PMCID: PMC9585818 DOI: 10.1186/s12915-022-01417-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 09/26/2022] [Indexed: 11/24/2022] Open
Abstract
Background Lipid homeostasis is an evolutionarily conserved process that is crucial for energy production, storage and consumption. Drosophila larvae feed continuously to achieve the roughly 200-fold increase in size and accumulate sufficient reserves to provide all energy and nutrients necessary for the development of the adult fly. The mechanisms controlling this metabolic program are poorly understood. Results Herein we identified a highly conserved gene, orsai (osi), as a key player in lipid metabolism in Drosophila. Lack of osi function in the larval fat body, the regulatory hub of lipid homeostasis, reduces lipid reserves and energy output, evidenced by decreased ATP production and increased ROS levels. Metabolic defects due to reduced Orsai (Osi) in time trigger defective food-seeking behavior and lethality. Further, we demonstrate that downregulation of Lipase 3, a fat body-specific lipase involved in lipid catabolism in response to starvation, rescues the reduced lipid droplet size associated with defective orsai. Finally, we show that osi-related phenotypes are rescued through the expression of its human ortholog ETFRF1/LYRm5, known to modulate the entry of β-oxidation products into the electron transport chain; moreover, knocking down electron transport flavoproteins EtfQ0 and walrus/ETFA rescues osi-related phenotypes, further supporting this mode of action. Conclusions These findings suggest that Osi may act in concert with the ETF complex to coordinate lipid homeostasis in the fat body in response to stage-specific demands, supporting cellular functions that in turn result in an adaptive behavioral response. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01417-w.
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Affiliation(s)
- Magdalena Fernandez-Acosta
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - Juan I Romero
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - Guillermo Bernabó
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina.,Present Address: Innovid, Buenos Aires, Argentina
| | - Giovanna M Velázquez-Campos
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - Nerina Gonzalez
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - M Lucía Mares
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - Santiago Werbajh
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina.,Present Address: Fundación Cassará, Buenos Aires, Argentina
| | - L Amaranta Avendaño-Vázquez
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina.,Present Address: IFIBYNE-CONICET, Buenos Aires, Argentina
| | - Gerald N Rechberger
- Institute for Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Ronald P Kühnlein
- Institute for Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Cristina Marino-Buslje
- Laboratorio de Bioinformática Estructural, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina
| | - Rafael Cantera
- Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.,Zoology Department, Stockholm University, Stockholm, Sweden
| | - Carolina Rezaval
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina.,Present Address: School of Biosciences, University of Birmingham, Birmingham, UK
| | - M Fernanda Ceriani
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA- CONICET), Buenos Aires, Argentina.
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5
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Almer G, Opriessnig P, Wolinski H, Sommer G, Diwoky C, Lechleitner M, Kolb D, Bubalo V, Brunner MS, Schwarz AN, Leitinger G, Schoiswohl G, Marsche G, Niedrist T, Schauer S, Oswald W, Groselj-Strele A, Paar M, Cvirn G, Hoefler G, Rechberger GN, Herrmann M, Frank S, Holzapfel GA, Kratky D, Mangge H, Hörl G, Tehlivets O. Deficiency of B vitamins leads to cholesterol-independent atherogenic transformation of the aorta. Biomed Pharmacother 2022; 154:113640. [PMID: 36081286 DOI: 10.1016/j.biopha.2022.113640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 11/02/2022] Open
Abstract
Atherosclerosis, the leading cause of cardiovascular disease responsible for the majority of deaths worldwide, cannot be sufficiently explained by established risk factors, including hypercholesterolemia. Elevated plasma homocysteine is an independent risk factor for atherosclerosis and is strongly linked to cardiovascular mortality. However, the role of homocysteine in atherosclerosis is still insufficiently understood. Previous research in this area has been also hampered by the lack of reproducible in vivo models of atherosclerosis that resemble the human situation. Here, we have developed and applied an automated system for vessel wall injury that leads to more homogenous damage and more pronounced atherosclerotic plaque development, even at low balloon pressure. Our automated system helped to glean vital details of cholesterol-independent changes in the aortic wall of balloon-injured rabbits. We show that deficiency of B vitamins, which are required for homocysteine degradation, leads to atherogenic transformation of the aorta resulting in accumulation of macrophages and lipids, impairment of its biomechanical properties and disorganization of aortic collagen/elastin in the absence of hypercholesterolemia. A combination of B vitamin deficiency and hypercholesterolemia leads to thickening of the aorta, decreased aortic water diffusion, increased LDL-cholesterol and impaired vascular reactivity compared to any single condition. Our findings suggest that deficiency of B vitamins leads to atherogenic transformation of the aorta even in the absence of hypercholesterolemia and aggravates atherosclerosis development in its presence.
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Affiliation(s)
- Gunter Almer
- Clinical Institute for Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Peter Opriessnig
- Division of General Neurology, Department of Neurology, Medical University of Graz, Graz, Austria; Division of Pediatric Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerhard Sommer
- Institute of Biomechanics, Graz University of Technology, Graz, Austria
| | - Clemens Diwoky
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Margarete Lechleitner
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria; Center for Medical Research, Ultrastructure Analysis, Medical University of Graz, Graz, Austria
| | - Vladimir Bubalo
- Division of Biomedical Research, Medical University of Graz, Graz, Austria
| | - Markus S Brunner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Andreas N Schwarz
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerd Leitinger
- Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Gabriele Schoiswohl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; Department of Pharmacology and Toxicology, University of Graz, Graz, Austria
| | - Gunther Marsche
- Otto Loewi Research Center, Pharmacology, Medical University of Graz, Graz, Austria
| | - Tobias Niedrist
- Clinical Institute for Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Silvia Schauer
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Wolfgang Oswald
- Department of Surgery, Clinical Division of Vascular Surgery, Medical University of Graz, Graz, Austria
| | - Andrea Groselj-Strele
- Center for Medical Research, Computational Bioanalytics, Medical University of Graz, Graz, Austria
| | - Margret Paar
- Otto Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Graz, Austria
| | - Gerhard Cvirn
- Otto Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Graz, Austria
| | - Gerald Hoefler
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | | | - Markus Herrmann
- Clinical Institute for Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Saša Frank
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, Graz, Austria; Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Harald Mangge
- Clinical Institute for Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Gerd Hörl
- Otto Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Graz, Austria.
| | - Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria.
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6
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Vigor C, Züllig T, Eichmann TO, Oger C, Zhou B, Rechberger GN, Hilsberg L, Trötzmüller M, Pellegrino RM, Alabed HBR, Hartler J, Wolinski H, Galano JM, Durand T, Spener F. α-Linolenic acid and product octadecanoids in Styrian pumpkin seeds and oils: How processing impacts lipidomes of fatty acid, triacylglycerol and oxylipin molecular structures. Food Chem 2022; 371:131194. [PMID: 34600364 DOI: 10.1016/j.foodchem.2021.131194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/06/2021] [Accepted: 09/16/2021] [Indexed: 12/13/2022]
Abstract
Styrian pumpkin seed oil is a conditioned green-colored oil renowned for nutty smell and taste. Due to α-linolenic acid (ALA) contents below 1% of total fatty acids and the prospect of nutritional health claims based on its potential oxidation products, we investigated the fate of ALA and product oxylipins in the course of down-stream processing of seeds and in oils. Lipidomic analyses with Lipid Data Analyzer 2.8.1 revealed: Processing did not change (1) main fatty acid composition in the oils, (2) amounts of triacylglycerol species, (3) structures of triacylglycerol molecular species containing ALA. (4) Minor precursor ALA in fresh Styrian and normal pumpkins produced 6 product phytoprostanes in either cultivar, quantitatively more in the latter. (5) In oil samples 7 phytoprostanes and 2 phytofurans were detected. The latter two are specific for their presence in pumpkin seed oils, of note, quantitatively more in conditioned oils than in cold-pressed native oils.
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Affiliation(s)
- Claire Vigor
- Institute of Biomolecules Max Mousseron, UMR 5247, CNRS, University of Montpellier, ENSCM, 34093 Montpellier, France
| | - Thomas Züllig
- Core Facility Mass Spectrometry, Medical University of Graz, Stiftingtalstr. 24, 8010 Graz, Austria
| | - Thomas O Eichmann
- Department of Molecular Biosciences, University of Graz, Heinrichstr. 31/II, 8010 Graz, Austria
| | - Camille Oger
- Institute of Biomolecules Max Mousseron, UMR 5247, CNRS, University of Montpellier, ENSCM, 34093 Montpellier, France
| | - Bingqing Zhou
- Institute of Biomolecules Max Mousseron, UMR 5247, CNRS, University of Montpellier, ENSCM, 34093 Montpellier, France
| | - Gerald N Rechberger
- Department of Molecular Biosciences, University of Graz, Heinrichstr. 31/II, 8010 Graz, Austria
| | | | - Martin Trötzmüller
- Core Facility Mass Spectrometry, Medical University of Graz, Stiftingtalstr. 24, 8010 Graz, Austria
| | - Roberto M Pellegrino
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via del Giochetto, Building B, 06126 Perugia, Italy
| | - Husam B R Alabed
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via del Giochetto, Building B, 06126 Perugia, Italy
| | - Jürgen Hartler
- Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1/I, 8010 Graz, Austria; Field of Excellence BioHealth - University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Heimo Wolinski
- Department of Molecular Biosciences, University of Graz, Heinrichstr. 31/II, 8010 Graz, Austria
| | - Jean-Marie Galano
- Institute of Biomolecules Max Mousseron, UMR 5247, CNRS, University of Montpellier, ENSCM, 34093 Montpellier, France
| | - Thierry Durand
- Institute of Biomolecules Max Mousseron, UMR 5247, CNRS, University of Montpellier, ENSCM, 34093 Montpellier, France
| | - Friedrich Spener
- Department of Molecular Biosciences, University of Graz, Heinrichstr. 31/II, 8010 Graz, Austria; Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6/6, 8010 Graz, Austria.
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7
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Marx L, Frewein MPK, Semeraro EF, Rechberger GN, Lohner K, Porcar L, Pabst G. Antimicrobial peptide activity in asymmetric bacterial membrane mimics. Faraday Discuss 2021; 232:435-447. [PMID: 34532723 PMCID: PMC8704130 DOI: 10.1039/d1fd00039j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022]
Abstract
We report on the response of asymmetric lipid membranes composed of palmitoyl oleoyl phosphatidylethanolamine and palmitoyl oleoyl phosphatidylglycerol, to interactions with the frog peptides L18W-PGLa and magainin 2 (MG2a), as well as the lactoferricin derivative LF11-215. In particular we determined the peptide-induced lipid flip-flop, as well as membrane partitioning of L18W-PGLa and LF11-215, and vesicle dye-leakage induced by L18W-PGLa. The ability of L18W-PGLa and MG2a to translocate through the membrane appears to correlate with the observed lipid flip-flop, which occurred at the fastest rate for L18W-PGLa. The higher structural flexibility of LF11-215 in turn allows this peptide to insert into the bilayers without detectable changes of membrane asymmetry. The increased vulnerability of asymmetric membranes to L18W-PGLa in terms of permeability, appears to be a consequence of tension differences between the compositionally distinct leaflets, but not due to increased peptide partitioning.
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Affiliation(s)
- Lisa Marx
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
| | - Moritz P K Frewein
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- Institut Laue-Langevin, 38043 Grenoble, France
| | - Enrico F Semeraro
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
| | - Gerald N Rechberger
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
| | - Karl Lohner
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
| | | | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
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8
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Prasch J, Bernhart E, Reicher H, Kollroser M, Rechberger GN, Koyani CN, Trummer C, Rech L, Rainer PP, Hammer A, Malle E, Sattler W. Myeloperoxidase-Derived 2-Chlorohexadecanal Is Generated in Mouse Heart during Endotoxemia and Induces Modification of Distinct Cardiomyocyte Protein Subsets In Vitro. Int J Mol Sci 2020; 21:ijms21239235. [PMID: 33287422 PMCID: PMC7730634 DOI: 10.3390/ijms21239235] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023] Open
Abstract
Sepsis is a major cause of mortality in critically ill patients and associated with cardiac dysfunction, a complication linked to immunological and metabolic aberrations. Cardiac neutrophil infiltration and subsequent release of myeloperoxidase (MPO) leads to the formation of the oxidant hypochlorous acid (HOCl) that is able to chemically modify plasmalogens (ether-phospholipids) abundantly present in the heart. This reaction gives rise to the formation of reactive lipid species including aldehydes and chlorinated fatty acids. During the present study, we tested whether endotoxemia increases MPO-dependent lipid oxidation/modification in the mouse heart. In hearts of lipopolysaccharide-injected mice, we observed significantly higher infiltration of MPO-positive cells, increased fatty acid content, and formation of 2-chlorohexadecanal (2-ClHDA), an MPO-derived plasmalogen modification product. Using murine HL-1 cardiomyocytes as in vitro model, we show that exogenously added HOCl attacks the cellular plasmalogen pool and gives rise to the formation of 2-ClHDA. Addition of 2-ClHDA to HL-1 cardiomyocytes resulted in conversion to 2-chlorohexadecanoic acid and 2-chlorohexadecanol, indicating fatty aldehyde dehydrogenase-mediated redox metabolism. However, a recovery of only 40% indicated the formation of non-extractable (protein) adducts. To identify protein targets, we used a clickable alkynyl analog, 2-chlorohexadec-15-yn-1-al (2-ClHDyA). After Huisgen 1,3-dipolar cycloaddition of 5-tetramethylrhodamine azide (N3-TAMRA) and two dimensional-gel electrophoresis (2D-GE), we were able to identify 51 proteins that form adducts with 2-ClHDyA. Gene ontology enrichment analyses revealed an overrepresentation of heat shock and chaperone, energy metabolism, and cytoskeletal proteins as major targets. Our observations in a murine endotoxemia model demonstrate formation of HOCl-modified lipids in the heart, while pathway analysis in vitro revealed that the chlorinated aldehyde targets specific protein subsets, which are central to cardiac function.
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Affiliation(s)
- Jürgen Prasch
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
| | - Eva Bernhart
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
| | - Helga Reicher
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
| | | | - Gerald N. Rechberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria;
- Center for Explorative Lipidomics, BioTechMed Graz, 8010 Graz, Austria
| | - Chintan N. Koyani
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8010 Graz, Austria; (L.R.); (P.P.R.)
| | - Christopher Trummer
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
| | - Lavinia Rech
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8010 Graz, Austria; (L.R.); (P.P.R.)
| | - Peter P. Rainer
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8010 Graz, Austria; (L.R.); (P.P.R.)
| | - Astrid Hammer
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria;
| | - Ernst Malle
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
| | - Wolfgang Sattler
- Division of Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, 8010 Graz, Austria; (J.P.); (E.B.); (H.R.); (C.N.K.); (C.T.); (E.M.)
- Center for Explorative Lipidomics, BioTechMed Graz, 8010 Graz, Austria
- Correspondence: ; Tel.: +43-316-385-71950
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9
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Zingl FG, Kohl P, Cakar F, Leitner DR, Mitterer F, Bonnington KE, Rechberger GN, Kuehn MJ, Guan Z, Reidl J, Schild S. Outer Membrane Vesiculation Facilitates Surface Exchange and In Vivo Adaptation of Vibrio cholerae. Cell Host Microbe 2019; 27:225-237.e8. [PMID: 31901519 DOI: 10.1016/j.chom.2019.12.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/25/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022]
Abstract
Gram-negative bacteria release outer membrane vesicles into the external milieu to deliver effector molecules that alter the host and facilitate virulence. Vesicle formation is driven by phospholipid accumulation in the outer membrane and regulated by the phospholipid transporter VacJ/Yrb. We use the facultative human pathogen Vibrio cholerae to show that VacJ/Yrb is silenced early during mammalian infection, which stimulates vesiculation that expedites bacterial surface exchange and adaptation to the host environment. Hypervesiculating strains rapidly alter their bacterial membrane composition and exhibit enhanced intestinal colonization fitness. This adaptation is exemplified by faster accumulation of glycine-modified lipopolysaccharide (LPS) and depletion of outer membrane porin OmpT, which confers resistance to host-derived antimicrobial peptides and bile, respectively. The competitive advantage of hypervesiculation is lost upon pre-adaptation to bile and antimicrobial peptides, indicating the importance of these adaptive processes. Thus, bacteria use outer membrane vesiculation to exchange cell surface components, thereby increasing survival during mammalian infection.
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Affiliation(s)
- Franz G Zingl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Paul Kohl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Fatih Cakar
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Deborah R Leitner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Gerald N Rechberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Center for Explorative Lipidomics, BioTechMed Graz, 8010 Graz, Austria
| | - Meta J Kuehn
- Duke University Medical Center, Durham, NC 27710, USA
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Joachim Reidl
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria.
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10
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Eicher B, Marquardt D, Heberle FA, Letofsky-Papst I, Rechberger GN, Appavou MS, Katsaras J, Pabst G. Intrinsic Curvature-Mediated Transbilayer Coupling in Asymmetric Lipid Vesicles. Biophys J 2019; 114:146-157. [PMID: 29320681 PMCID: PMC5773765 DOI: 10.1016/j.bpj.2017.11.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/30/2017] [Accepted: 11/09/2017] [Indexed: 11/16/2022] Open
Abstract
We measured the effect of intrinsic lipid curvature, J0, on structural properties of asymmetric vesicles made of palmitoyl-oleoyl-phosphatidylethanolamine (POPE; J0<0) and palmitoyl-oleoyl-phosphatidylcholine (POPC; J0∼0). Electron microscopy and dynamic light scattering were used to determine vesicle size and morphology, and x-ray and neutron scattering, combined with calorimetric experiments and solution NMR, yielded insights into leaflet-specific lipid packing and melting processes. Below the lipid melting temperature we observed strong interleaflet coupling in asymmetric vesicles with POPE inner bilayer leaflets and outer leaflets enriched in POPC. This lipid arrangement manifested itself by lipids melting cooperatively in both leaflets, and a rearrangement of lipid packing in both monolayers. On the other hand, no coupling was observed in vesicles with POPC inner bilayer leaflets and outer leaflets enriched in POPE. In this case, the leaflets melted independently and did not affect each other’s acyl chain packing. Furthermore, we found no evidence for transbilayer structural coupling above the melting temperature of either sample preparation. Our results are consistent with the energetically preferred location of POPE residing in the inner leaflet, where it also resides in natural membranes, most likely causing the coupling of both leaflets. The loss of this coupling in the fluid bilayers is most likely the result of entropic contributions.
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Affiliation(s)
- Barbara Eicher
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz; BioTechMed-Graz, Graz, Austria
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Frederick A Heberle
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee; The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Ilse Letofsky-Papst
- Institute for Electron Microscopy and Nanoanalysis and Center for Electron Microscopy, Graz University of Technology, NAWI Graz
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, University of Graz, Graz, Austria; Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Garching, Germany; Forschungszentrum Jülich GmbH, Institut für Festkörperforschung, Jülich Center for Neutron Science at FRM II Outstation, Garching, Germany
| | - John Katsaras
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee; The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz; BioTechMed-Graz, Graz, Austria.
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11
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Bhutada G, Kavšcek M, Ledesma-Amaro R, Thomas S, Rechberger GN, Nicaud JM, Natter K. Sugar versus fat: elimination of glycogen storage improves lipid accumulation in Yarrowia lipolytica. FEMS Yeast Res 2018; 17:3798535. [PMID: 28475761 PMCID: PMC5812513 DOI: 10.1093/femsyr/fox020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/12/2017] [Indexed: 01/01/2023] Open
Abstract
Triacylglycerol (TAG) and glycogen are the two major metabolites for carbon storage in most eukaryotic organisms. We investigated the glycogen metabolism of the oleaginous Yarrowia lipolytica and found that this yeast accumulates up to 16% glycogen in its biomass. Assuming that elimination of glycogen synthesis would result in an improvement of lipid accumulation, we characterized and deleted the single gene coding for glycogen synthase, YlGSY1. The mutant was grown under lipogenic conditions with glucose and glycerol as substrates and we obtained up to 60% improvement in TAG accumulation compared to the wild-type strain. Additionally, YlGSY1 was deleted in a background that was already engineered for high lipid accumulation. In this obese background, TAG accumulation was also further increased. The highest lipid content of 52% was found after 3 days of cultivation in nitrogen-limited glycerol medium. Furthermore, we constructed mutants of Y. lipolytica and Saccharomyces cerevisiae that are deleted for both glycogen and TAG synthesis, demonstrating that the ability to store carbon is not essential. Overall, this work showed that glycogen synthesis is a competing pathway for TAG accumulation in oleaginous yeasts and that deletion of the glycogen synthase has beneficial effects on neutral lipid storage.
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Affiliation(s)
- Govindprasad Bhutada
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Martin Kavšcek
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Rodrigo Ledesma-Amaro
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Stéphane Thomas
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria.,Omics Center Graz, BioTechMed Graz, 8010 Graz, Austria
| | - Jean-Marc Nicaud
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Klaus Natter
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
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12
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Visram M, Radulovic M, Steiner S, Malanovic N, Eichmann TO, Wolinski H, Rechberger GN, Tehlivets O. Homocysteine regulates fatty acid and lipid metabolism in yeast. J Biol Chem 2018; 293:5544-5555. [PMID: 29414770 PMCID: PMC5900771 DOI: 10.1074/jbc.m117.809236] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 02/05/2018] [Indexed: 01/03/2023] Open
Abstract
S-Adenosyl-l-homocysteine hydrolase (AdoHcy hydrolase; Sah1 in yeast/AHCY in mammals) degrades AdoHcy, a by-product and strong product inhibitor of S-adenosyl-l-methionine (AdoMet)-dependent methylation reactions, to adenosine and homocysteine (Hcy). This reaction is reversible, so any elevation of Hcy levels, such as in hyperhomocysteinemia (HHcy), drives the formation of AdoHcy, with detrimental consequences for cellular methylation reactions. HHcy, a pathological condition linked to cardiovascular and neurological disorders, as well as fatty liver among others, is associated with a deregulation of lipid metabolism. Here, we developed a yeast model of HHcy to identify mechanisms that dysregulate lipid metabolism. Hcy supplementation to wildtype cells up-regulated cellular fatty acid and triacylglycerol content and induced a shift in fatty acid composition, similar to changes observed in mutants lacking Sah1. Expression of the irreversible bacterial pathway for AdoHcy degradation in yeast allowed us to dissect the impact of AdoHcy accumulation on lipid metabolism from the impact of elevated Hcy. Expression of this pathway fully suppressed the growth deficit of sah1 mutants as well as the deregulation of lipid metabolism in both the sah1 mutant and Hcy-exposed wildtype, showing that AdoHcy accumulation mediates the deregulation of lipid metabolism in response to elevated Hcy in yeast. Furthermore, Hcy supplementation in yeast led to increased resistance to cerulenin, an inhibitor of fatty acid synthase, as well as to a concomitant decline of condensing enzymes involved in very long-chain fatty acid synthesis, in line with the observed shift in fatty acid content and composition.
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Affiliation(s)
- Myriam Visram
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Maja Radulovic
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Sabine Steiner
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Nermina Malanovic
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Thomas O. Eichmann
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Heimo Wolinski
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
| | - Gerald N. Rechberger
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and ,the Omics Center Graz, BioTechMed-Graz, 8010 Graz, Austria
| | - Oksana Tehlivets
- From the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria and
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13
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Zisser G, Ohmayer U, Mauerhofer C, Mitterer V, Klein I, Rechberger GN, Wolinski H, Prattes M, Pertschy B, Milkereit P, Bergler H. Viewing pre-60S maturation at a minute's timescale. Nucleic Acids Res 2018; 46:3140-3151. [PMID: 29294095 PMCID: PMC5888160 DOI: 10.1093/nar/gkx1293] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/30/2017] [Accepted: 12/18/2017] [Indexed: 12/03/2022] Open
Abstract
The formation of ribosomal subunits is a highly dynamic process that is initiated in the nucleus and involves more than 200 trans-acting factors, some of which accompany the pre-ribosomes into the cytoplasm and have to be recycled into the nucleus. The inhibitor diazaborine prevents cytoplasmic release and recycling of shuttling pre-60S maturation factors by inhibiting the AAA-ATPase Drg1. The failure to recycle these proteins results in their depletion in the nucleolus and halts the pathway at an early maturation step. Here, we made use of the fast onset of inhibition by diazaborine to chase the maturation path in real-time from 27SA2 pre-rRNA containing pre-ribosomes localized in the nucleolus up to nearly mature 60S subunits shortly after their export into the cytoplasm. This allows for the first time to put protein assembly and disassembly reactions as well as pre-rRNA processing into a chronological context unraveling temporal and functional linkages during ribosome maturation.
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Affiliation(s)
- Gertrude Zisser
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Uli Ohmayer
- Lehrstuhl Biochemie III, University Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Christina Mauerhofer
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Valentin Mitterer
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Isabella Klein
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- Omics Center Graz, BioTechMed-Graz, A-8010 Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
| | - Michael Prattes
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
| | - Philipp Milkereit
- Lehrstuhl Biochemie III, University Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Helmut Bergler
- Institute of Molecular Biosciences, Humboldtstrasse 50/EG, University of Graz, A-8010 Graz, Austria
- BioTechMed-Graz, A-8010 Graz, Austria
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14
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Hartler J, Triebl A, Ziegl A, Trötzmüller M, Rechberger GN, Zeleznik OA, Zierler KA, Torta F, Cazenave-Gassiot A, Wenk MR, Fauland A, Wheelock CE, Armando AM, Quehenberger O, Zhang Q, Wakelam MJO, Haemmerle G, Spener F, Köfeler HC, Thallinger GG. Deciphering lipid structures based on platform-independent decision rules. Nat Methods 2017; 14:1171-1174. [PMID: 29058722 PMCID: PMC5988032 DOI: 10.1038/nmeth.4470] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 09/19/2017] [Indexed: 11/23/2022]
Abstract
We achieve automated and reliable annotation of lipid species and their molecular structures in high-throughput data from chromatography-coupled tandem mass spectrometry using decision rule sets embedded in Lipid Data Analyzer (LDA; http://genome.tugraz.at/lda2). Using various low- and high-resolution mass spectrometry instruments with several collision energies, we proved the method's platform independence. We propose that the software's reliability, flexibility, and ability to identify novel lipid molecular species may now render current state-of-the-art lipid libraries obsolete.
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Affiliation(s)
- Jürgen Hartler
- Institute of Computational Biotechnology, Graz University of Technology, Graz, Austria
- Center for Medical Research, Medical University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Alexander Triebl
- Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Andreas Ziegl
- Institute of Computational Biotechnology, Graz University of Technology, Graz, Austria
| | - Martin Trötzmüller
- Center for Medical Research, Medical University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Gerald N Rechberger
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
- Department of Molecular Biosciences, University of Graz, Graz, Austria
| | - Oana A Zeleznik
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, U.S.A
| | - Kathrin A Zierler
- Department of Molecular Biosciences, University of Graz, Graz, Austria
| | - Federico Torta
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
| | | | - Markus R Wenk
- Singapore Lipidomics Incubator, National University of Singapore, Singapore, Singapore
| | - Alexander Fauland
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Craig E Wheelock
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Aaron M Armando
- School of Medicine, University of California San Diego, La Jolla, California, U.S.A
| | - Oswald Quehenberger
- School of Medicine, University of California San Diego, La Jolla, California, U.S.A
| | - Qifeng Zhang
- The Babraham Institute, Babraham Research Campus, Cambridge, U.K
| | | | - Guenter Haemmerle
- Department of Molecular Biosciences, University of Graz, Graz, Austria
| | - Friedrich Spener
- Department of Molecular Biosciences, University of Graz, Graz, Austria
- Department of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Harald C Köfeler
- Center for Medical Research, Medical University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Gerhard G Thallinger
- Institute of Computational Biotechnology, Graz University of Technology, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
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15
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Ring J, Rockenfeller P, Abraham C, Tadic J, Poglitsch M, Schimmel K, Westermayer J, Schauer S, Achleitner B, Schimpel C, Moitzi B, Rechberger GN, Sigrist SJ, Carmona-Gutierrez D, Kroemer G, Büttner S, Eisenberg T, Madeo F. Mitochondrial energy metabolism is required for lifespan extension by the spastic paraplegia-associated protein spartin. Microb Cell 2017; 4:411-422. [PMID: 29234670 PMCID: PMC5722644 DOI: 10.15698/mic2017.12.603] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 11/20/2017] [Indexed: 01/11/2023]
Abstract
Hereditary spastic paraplegias, a group of neurodegenerative disorders, can be caused by loss-of-function mutations in the protein spartin. However, the physiological role of spartin remains largely elusive. Here we show that heterologous expression of human or Drosophila spartin extends chronological lifespan of yeast, reducing age-associated ROS production, apoptosis, and necrosis. We demonstrate that spartin localizes to the proximity of mitochondria and physically interacts with proteins related to mitochondrial and respiratory metabolism. Interestingly, Nde1, the mitochondrial external NADH dehydrogenase, and Pda1, the core enzyme of the pyruvate dehydrogenase complex, are required for spartin-mediated cytoprotection. Furthermore, spartin interacts with the glycolysis enhancer phospo-fructo-kinase-2,6 (Pfk26) and is sufficient to complement for PFK26-deficiency at least in early aging. We conclude that mitochondria-related energy metabolism is crucial for spartin's vital function during aging and uncover a network of specific interactors required for this function.
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Affiliation(s)
- Julia Ring
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Patrick Rockenfeller
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, UK
| | - Claudia Abraham
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Jelena Tadic
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Michael Poglitsch
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Katherina Schimmel
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), IFB-Tx, Hannover Medical School, Hannover, Germany
| | - Julia Westermayer
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Simon Schauer
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Bettina Achleitner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Christa Schimpel
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- BioNanoNet Forschungsgesellschaft mbH, Graz, Austria
| | - Barbara Moitzi
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Gerald N. Rechberger
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- Omics Center Graz, BioTechMed-Graz, Graz, Austria
| | - Stephan J. Sigrist
- Institute for Biology, Freie Universität Berlin, Berlin, Germany
- NeuroCure, Charité, Berlin, Germany
| | | | - Guido Kroemer
- BioTechMed Graz, Graz, Austria
- Cell Biology and Metabolomics Platforms, Gustave Roussy Comprehensive Cancer Center, Villejuif, France
- INSERM, U1138, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou, Paris, France
- Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital Stockholm, Sweden
| | - Sabrina Büttner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Tobias Eisenberg
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
| | - Frank Madeo
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
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16
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Bhutada G, Kavšcek M, Ledesma-Amaro R, Thomas S, Rechberger GN, Nicaud JM, Natter K. Sugar versus fat: elimination of glycogen storage improves lipid accumulation in Yarrowia lipolytica. FEMS Yeast Res 2017; 17:3798535. [PMID: 28475761 DOI: 10.1093/femsyr/fox020/3798535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/12/2017] [Indexed: 05/23/2023] Open
Abstract
Triacylglycerol (TAG) and glycogen are the two major metabolites for carbon storage in most eukaryotic organisms. We investigated the glycogen metabolism of the oleaginous Yarrowia lipolytica and found that this yeast accumulates up to 16% glycogen in its biomass. Assuming that elimination of glycogen synthesis would result in an improvement of lipid accumulation, we characterized and deleted the single gene coding for glycogen synthase, YlGSY1. The mutant was grown under lipogenic conditions with glucose and glycerol as substrates and we obtained up to 60% improvement in TAG accumulation compared to the wild-type strain. Additionally, YlGSY1 was deleted in a background that was already engineered for high lipid accumulation. In this obese background, TAG accumulation was also further increased. The highest lipid content of 52% was found after 3 days of cultivation in nitrogen-limited glycerol medium. Furthermore, we constructed mutants of Y. lipolytica and Saccharomyces cerevisiae that are deleted for both glycogen and TAG synthesis, demonstrating that the ability to store carbon is not essential. Overall, this work showed that glycogen synthesis is a competing pathway for TAG accumulation in oleaginous yeasts and that deletion of the glycogen synthase has beneficial effects on neutral lipid storage.
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Affiliation(s)
- Govindprasad Bhutada
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Martin Kavšcek
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Rodrigo Ledesma-Amaro
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Stéphane Thomas
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
- Omics Center Graz, BioTechMed Graz, 8010 Graz, Austria
| | - Jean-Marc Nicaud
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Klaus Natter
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
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17
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Bhutada G, Kavšček M, Ledesma-Amaro R, Thomas S, Rechberger GN, Nicaud JM, Natter K. Sugar versus fat: elimination of glycogen storage improves lipid accumulation inYarrowia lipolytica. FEMS Yeast Res 2017. [DOI: 10.1093/femsle/fox020] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Govindprasad Bhutada
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Martin Kavšček
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Rodrigo Ledesma-Amaro
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Stéphane Thomas
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Gerald N. Rechberger
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
- Omics Center Graz, BioTechMed Graz, 8010 Graz, Austria
| | - Jean-Marc Nicaud
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Klaus Natter
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
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18
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Eicher B, Heberle FA, Marquardt D, Rechberger GN, Katsaras J, Pabst G. Joint small-angle X-ray and neutron scattering data analysis of asymmetric lipid vesicles. J Appl Crystallogr 2017; 50:419-429. [PMID: 28381971 PMCID: PMC5377341 DOI: 10.1107/s1600576717000656] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/12/2017] [Indexed: 11/10/2022] Open
Abstract
Low- and high-resolution models describing the internal transbilayer structure of asymmetric lipid vesicles have been developed. These models can be used for the joint analysis of small-angle neutron and X-ray scattering data. The models describe the underlying scattering length density/electron density profiles either in terms of slabs or through the so-called scattering density profile, previously applied to symmetric lipid vesicles. Both models yield structural details of asymmetric membranes, such as the individual area per lipid, and the hydrocarbon thickness of the inner and outer bilayer leaflets. The scattering density profile model, however, comes at a cost of increased computational effort but results in greater structural resolution, showing a slightly lower packing of lipids in the outer bilayer leaflet of ∼120 nm diameter palmitoyl-oleoyl phosphatidyl-choline (POPC) vesicles, compared to the inner leaflet. Analysis of asymmetric dipalmitoyl phosphatidylcholine/POPC vesicles did not reveal evidence of transbilayer coupling between the inner and outer leaflets at 323 K, i.e. above the melting transition temperature of the two lipids.
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Affiliation(s)
- Barbara Eicher
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
| | - Frederick A Heberle
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, USA; Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Drew Marquardt
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
| | - Gerald N Rechberger
- Instiute of Molecular Biosciences, University of Graz, Austria; Omics-Center Graz, BioTechMed-Graz, Austria
| | - John Katsaras
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Georg Pabst
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
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19
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Čas D, Hurkes N, Spirk S, Belaj F, Bruhn C, Rechberger GN, Pietschnig R. Dimer formation upon deprotonation: synthesis and structure of a m-terphenyl substituted (R,S)-dilithium disiloxanolate disilanol. Dalton Trans 2015; 44:12818-23. [DOI: 10.1039/c5dt01992c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The primary products in deprotonating m-terphenylsilanetriol were detected in traces besides disiloxanes as major products, which were characterized as donor adducts.
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Affiliation(s)
- Daniel Čas
- Universität Kassel
- Institut für Chemie und CINSaT
- 34132 Kassel
- Germany
| | - Natascha Hurkes
- Universität Kassel
- Institut für Chemie und CINSaT
- 34132 Kassel
- Germany
| | - Stefan Spirk
- Karl-Franzens-Universität
- Institut für Chemie
- NAWI Graz
- 8010 Graz
- Austria
| | - Ferdinand Belaj
- Karl-Franzens-Universität
- Institut für Chemie
- NAWI Graz
- 8010 Graz
- Austria
| | - Clemens Bruhn
- Universität Kassel
- Institut für Chemie und CINSaT
- 34132 Kassel
- Germany
| | - Gerald N. Rechberger
- Karl-Franzens-Universität
- Institut für Molekulare Biowissenschaften
- 8010 Graz
- Austria
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20
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Hofbauer HF, Schopf FH, Schleifer H, Knittelfelder OL, Pieber B, Rechberger GN, Wolinski H, Gaspar ML, Kappe CO, Stadlmann J, Mechtler K, Zenz A, Lohner K, Tehlivets O, Henry SA, Kohlwein SD. Regulation of gene expression through a transcriptional repressor that senses acyl-chain length in membrane phospholipids. Dev Cell 2014; 29:729-39. [PMID: 24960695 PMCID: PMC4070385 DOI: 10.1016/j.devcel.2014.04.025] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 04/01/2014] [Accepted: 04/22/2014] [Indexed: 12/20/2022]
Abstract
Membrane phospholipids typically contain fatty acids (FAs) of 16 and 18 carbon atoms. This particular chain length is evolutionarily highly conserved and presumably provides maximum stability and dynamic properties to biological membranes in response to nutritional or environmental cues. Here, we show that the relative proportion of C16 versus C18 FAs is regulated by the activity of acetyl-CoA carboxylase (Acc1), the first and rate-limiting enzyme of FA de novo synthesis. Acc1 activity is attenuated by AMPK/Snf1-dependent phosphorylation, which is required to maintain an appropriate acyl-chain length distribution. Moreover, we find that the transcriptional repressor Opi1 preferentially binds to C16 over C18 phosphatidic acid (PA) species: thus, C16-chain containing PA sequesters Opi1 more effectively to the ER, enabling AMPK/Snf1 control of PA acyl-chain length to determine the degree of derepression of Opi1 target genes. These findings reveal an unexpected regulatory link between the major energy-sensing kinase, membrane lipid composition, and transcription. AMPK/Snf1 inhibition of acetyl-CoA carboxylase controls fatty acyl-chain length Opi1 repressor preferentially binds to C16 rather than C18 acyl-chains in PA Acyl-chain length tunes Opi1 sequestration to the ER and target gene derepression AMPK/Snf1 thus uses its effect on acyl-chain length to control Opi1 target genes
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Affiliation(s)
- Harald F Hofbauer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Florian H Schopf
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Hannes Schleifer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Oskar L Knittelfelder
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Bartholomäus Pieber
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Maria L Gaspar
- Department of Molecular Biology and Genetics, 249 Biotechnology Building, Cornell University, Ithaca, NY 14853-2703, USA
| | - C Oliver Kappe
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Johannes Stadlmann
- Protein Chemistry Facility, Institute of Molecular Pathology (IMP), Doktor-Bohr-Gasse 7, 1030 Vienna, Austria
| | - Karl Mechtler
- Protein Chemistry Facility, IMBA Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Doktor-Bohr-Gasse 3, 1030 Vienna, Austria
| | - Alexandra Zenz
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria
| | - Karl Lohner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - Susan A Henry
- Department of Molecular Biology and Genetics, 249 Biotechnology Building, Cornell University, Ithaca, NY 14853-2703, USA
| | - Sepp D Kohlwein
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50/II, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria.
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21
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Knittelfelder OL, Weberhofer BP, Eichmann TO, Kohlwein SD, Rechberger GN. A versatile ultra-high performance LC-MS method for lipid profiling. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 951-952:119-28. [PMID: 24548922 PMCID: PMC3946075 DOI: 10.1016/j.jchromb.2014.01.011] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 11/17/2022]
Abstract
A new UPLC-based untargeted lipidomic approach using a qTOF hybrid mass spectrometer is introduced. The applied binary gradient enables separations of lipid species including constitutional isomeric compounds and low abundant lipid classes such as phosphatidic acid (PA). Addition of phosphoric acid to the solvents improves peak shapes for acidic phospholipids. MS(E) scans allow simultaneous acquisition of full scan data and collision induced fragmentation to improve identification of lipid classes and to obtain structural information. The method was used to investigate the lipidome of yeast.
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Affiliation(s)
- Oskar L Knittelfelder
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/II, 8010 Graz, Austria
| | - Bernd P Weberhofer
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/II, 8010 Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/II, 8010 Graz, Austria
| | - Sepp D Kohlwein
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/II, 8010 Graz, Austria
| | - Gerald N Rechberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50/II, 8010 Graz, Austria; Omics Center Graz, Austria.
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22
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Alza NP, Pferschy-Wenzig EM, Ortmann S, Kretschmer N, Kunert O, Rechberger GN, Bauer R, Murray AP. Inhibition of NO Production byGrindelia argentinaand Isolation of Three New Cytotoxic Saponins. Chem Biodivers 2014; 11:311-22. [DOI: 10.1002/cbdv.201300193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Indexed: 11/12/2022]
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23
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Roier S, Fenninger JC, Leitner DR, Rechberger GN, Reidl J, Schild S. Immunogenicity of Pasteurella multocida and Mannheimia haemolytica outer membrane vesicles. Int J Med Microbiol 2013; 303:247-56. [PMID: 23731905 PMCID: PMC3717205 DOI: 10.1016/j.ijmm.2013.05.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 04/29/2013] [Accepted: 05/05/2013] [Indexed: 01/29/2023] Open
Abstract
Pasteurella multocida is able to cause disease in humans and in a wide range of animal hosts, including fowl cholera in birds, atrophic rhinitis in pigs, and snuffles in rabbits. Together with Mannheimia haemolytica, P. multocida also represents a major bacterial causative agent of bovine respiratory disease (BRD), which is one of the most important causes for economic losses for the cattle backgrounding and feedlot industry. Commercially available vaccines only partially prevent infections caused by P. multocida and M. haemolytica. Thus, this study characterized the immunogenicity of P. multocida and M. haemolytica outer membrane vesicles (OMVs) upon intranasal immunization of BALB/c mice. Enzyme-linked immunosorbent assays (ELISA) revealed that OMVs derived from P. multocida or M. haemolytica are able to induce robust humoral and mucosal immune responses against the respective donor strain. In addition, also significant cross-immunogenic potential was observed for both OMV types. Colonization studies showed that a potential protective immune response against P. multocida is not only achieved by immunization with P. multocida OMVs, but also by immunization with OMVs derived from M. haemolytica. Immunoblot and immunoprecipitation analyses demonstrated that M. haemolytica OMVs induce a more complex immune response compared to P. multocida OMVs. The outer membrane proteins OmpA, OmpH, and P6 were identified as the three major immunogenic proteins of P. multocida OMVs. Amongst others, the serotype 1-specific antigen, an uncharacterized outer membrane protein, as well as the outer membrane proteins P2 and OmpA were found to be the most important antigens of M. haemolytica OMVs. These findings are useful for the future development of broad-spectrum OMV based vaccines against BRD and other infections caused by P. multocida or M. haemolytica.
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Affiliation(s)
- Sandro Roier
- Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, A-8010 Graz, Austria
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24
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Zierler KA, Jaeger D, Pollak NM, Eder S, Rechberger GN, Radner FPW, Woelkart G, Kolb D, Schmidt A, Kumari M, Preiss-Landl K, Pieske B, Mayer B, Zimmermann R, Lass A, Zechner R, Haemmerle G. Functional cardiac lipolysis in mice critically depends on comparative gene identification-58. J Biol Chem 2013; 288:9892-9904. [PMID: 23413028 DOI: 10.1074/jbc.m112.420620] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Efficient catabolism of cellular triacylglycerol (TG) stores requires the TG hydrolytic activity of adipose triglyceride lipase (ATGL). The presence of comparative gene identification-58 (CGI-58) strongly increased ATGL-mediated TG catabolism in cell culture experiments. Mutations in the genes coding for ATGL or CGI-58 in humans cause neutral lipid storage disease characterized by TG accumulation in multiple tissues. ATGL gene mutations cause a severe phenotype especially in cardiac muscle leading to cardiomyopathy that can be lethal. In contrast, CGI-58 gene mutations provoke severe ichthyosis and hepatosteatosis in humans and mice, whereas the role of CGI-58 in muscle energy metabolism is less understood. Here we show that mice lacking CGI-58 exclusively in muscle (CGI-58KOM) developed severe cardiac steatosis and cardiomyopathy linked to impaired TG catabolism and mitochondrial fatty acid oxidation. The marked increase in ATGL protein levels in cardiac muscle of CGI-58KOM mice was unable to compensate the lack of CGI-58. The addition of recombinant CGI-58 to cardiac lysates of CGI-58KOM mice completely reconstituted TG hydrolytic activities. In skeletal muscle, the lack of CGI-58 similarly provoked TG accumulation. The addition of recombinant CGI-58 increased TG hydrolytic activities in control and CGI-58KOM tissue lysates, elucidating the limiting role of CGI-58 in skeletal muscle TG catabolism. Finally, muscle CGI-58 deficiency affected whole body energy homeostasis, which is caused by impaired muscle TG catabolism and increased cardiac glucose uptake. In summary, this study demonstrates that functional muscle lipolysis depends on both CGI-58 and ATGL.
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Affiliation(s)
- Kathrin A Zierler
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Doris Jaeger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Nina M Pollak
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Sandra Eder
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Gerald Woelkart
- Department of Pharmacology and Toxicology, University of Graz, 8010 Graz, Austria
| | - Dagmar Kolb
- Center for Medical Research, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
| | - Albrecht Schmidt
- Department of Cardiology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
| | - Manju Kumari
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Burkert Pieske
- Department of Cardiology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
| | - Bernd Mayer
- Department of Pharmacology and Toxicology, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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25
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Morak M, Schmidinger H, Riesenhuber G, Rechberger GN, Kollroser M, Haemmerle G, Zechner R, Kronenberg F, Hermetter A. Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) deficiencies affect expression of lipolytic activities in mouse adipose tissues. Mol Cell Proteomics 2012; 11:1777-89. [PMID: 22984285 DOI: 10.1074/mcp.m111.015743] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) are key enzymes involved in intracellular degradation of triacylglycerols. It was the aim of this study to elucidate how the deficiency in one of these proteins affects the residual lipolytic proteome in adipose tissue. For this purpose, we compared the lipase patterns of brown and white adipose tissue from ATGL (-/-) and HSL (-/-) mice using differential activity-based gel electrophoresis. This method is based on activity-recognition probes possessing the same substrate analogous structure but carrying different fluorophores for specific detection of the enzyme patterns of two different tissues in one electrophoresis gel. We found that ATGL-deficiency in brown adipose tissue had a profound effect on the expression levels of other lipolytic and esterolytic enzymes in this tissue, whereas HSL-deficiency hardly showed any effect in brown adipose tissue. Neither ATGL- nor HSL-deficiency greatly influenced the lipase patterns in white adipose tissue. Enzyme activities of mouse tissues on acylglycerol substrates were analyzed as well, showing that ATGL-and HSL-deficiencies can be compensated for at least in part by other enzymes. The proteins that responded to ATGL-deficiency in brown adipose tissue were overexpressed and their activities on acylglycerols were analyzed. Among these enzymes, Es1, Es10, and Es31-like represent lipase candidates as they catalyze the hydrolysis of long-chain acylglycerols.
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Affiliation(s)
- Maria Morak
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
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26
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Damm M, Nusshold C, Cantillo D, Rechberger GN, Gruber K, Sattler W, Kappe CO. Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols. J Proteomics 2012; 75:5533-43. [PMID: 22889711 PMCID: PMC3484400 DOI: 10.1016/j.jprot.2012.07.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/27/2012] [Accepted: 07/27/2012] [Indexed: 10/31/2022]
Abstract
This study reevaluates the putative advantages of microwave-assisted tryptic digests compared to conventionally heated protocols performed at the same temperature. An initial investigation of enzyme stability in a temperature range of 37-80 °C demonstrated that trypsin activity declines sharply at temperatures above 60 °C, regardless if microwave dielectric heating or conventional heating is employed. Tryptic digests of three proteins of different size (bovine serum albumin, cytochrome c and β-casein) were thus performed at 37 °C and 50 °C using both microwave and conventional heating applying accurate internal fiber-optic probe reaction temperature measurements. The impact of the heating method on protein degradation and peptide fragment generation was analyzed by SDS-PAGE and MALDI-TOF-MS. Time-dependent tryptic digestion of the three proteins and subsequent analysis of the corresponding cleavage products by MALDI-TOF provided virtually identical results for both microwave and conventional heating. In addition, the impact of electromagnetic field strength on the tertiary structure of trypsin and BSA was evaluated by molecular mechanics calculations. These simulations revealed that the applied field in a typical laboratory microwave reactor is 3-4 orders of magnitude too low to induce conformational changes in proteins or enzymes.
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Affiliation(s)
- Markus Damm
- Christian Doppler Laboratory for Microwave Chemistry (CDLMC) and Institute of Chemistry, Karl-Franzens-University Graz, Heinrichstrasse 28/I, A-8010 Graz, Austria
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27
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Kosol S, Schrank E, Krajačić MB, Wagner GE, Meyer NH, Göbl C, Rechberger GN, Zangger K, Novak P. Probing the Interactions of Macrolide Antibiotics with Membrane-Mimetics by NMR Spectroscopy. J Med Chem 2012; 55:5632-6. [DOI: 10.1021/jm300647f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Simone Kosol
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | - Evelyne Schrank
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | | | - Gabriel E. Wagner
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | - N. Helge Meyer
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | - Christoph Göbl
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | - Gerald N. Rechberger
- Institute of Molecular Biosciences,
University of Graz, Humboldtstrasse 50, A-8010 Graz, Austria
| | - Klaus Zangger
- Institute
of Chemistry/Organic
and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28,
A-8010 Graz, Austria
| | - Predrag Novak
- Department of Chemistry, Faculty
of Natural Science, University of Zagreb, Laboratory for Analytical
Chemistry, Horvatovac 102a, HR-10000 Zagreb, Croatia
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28
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Kumari M, Schoiswohl G, Chitraju C, Paar M, Cornaciu I, Rangrez AY, Wongsiriroj N, Nagy HM, Ivanova PT, Scott SA, Knittelfelder O, Rechberger GN, Birner-Gruenberger R, Eder S, Brown HA, Haemmerle G, Oberer M, Lass A, Kershaw EE, Zimmermann R, Zechner R. Adiponutrin functions as a nutritionally regulated lysophosphatidic acid acyltransferase. Cell Metab 2012; 15:691-702. [PMID: 22560221 PMCID: PMC3361708 DOI: 10.1016/j.cmet.2012.04.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 02/17/2012] [Accepted: 04/10/2012] [Indexed: 12/12/2022]
Abstract
Numerous studies in humans link a nonsynonymous genetic polymorphism (I148M) in adiponutrin (ADPN) to various forms of fatty liver disease and liver cirrhosis. Despite its high clinical relevance, the molecular function of ADPN and the mechanism by which I148M variant affects hepatic metabolism are unclear. Here we show that ADPN promotes cellular lipid synthesis by converting lysophosphatidic acid (LPA) into phosphatidic acid. The ADPN-catalyzed LPA acyltransferase (LPAAT) reaction is specific for LPA and long-chain acyl-CoAs. Wild-type mice receiving a high-sucrose diet exhibit substantial upregulation of Adpn in the liver and a concomitant increase in LPAAT activity. In Adpn-deficient mice, this diet-induced increase in hepatic LPAAT activity is reduced. Notably, the I148M variant of human ADPN exhibits increased LPAAT activity leading to increased cellular lipid accumulation. This gain of function provides a plausible biochemical mechanism for the development of liver steatosis in subjects carrying the I148M variant.
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Affiliation(s)
- Manju Kumari
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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29
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Birner-Gruenberger R, Bickmeyer I, Lange J, Hehlert P, Hermetter A, Kollroser M, Rechberger GN, Kühnlein RP. Functional fat body proteomics and gene targeting reveal in vivo functions of Drosophila melanogaster α-Esterase-7. Insect Biochem Mol Biol 2012; 42:220-229. [PMID: 22198472 DOI: 10.1016/j.ibmb.2011.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Revised: 12/07/2011] [Accepted: 12/08/2011] [Indexed: 05/31/2023]
Abstract
Carboxylesterases constitute a large enzyme family in insects, which is involved in diverse functions such as xenobiotic detoxification, lipid metabolism and reproduction. Phylogenetically, many insect carboxylesterases are represented by multienzyme clades, which are encoded by evolutionarily ancient gene clusters such as the α-Esterase cluster. Much in contrast to the vital importance attributed to carboxylesterases in general, the in vivo function of individual α-Esterase genes is largely unknown. This study employs a functional proteomics approach to identify esterolytic enzymes of the vinegar fly Drosophila melanogaster fat body. One of the fat body carboxylesterases, α-Esterase-7, was selected for mutational analysis by gene targeting to generate a deletion mutant fly. Phenotypic characterization of α-Esterase-7 null mutants and transgenic flies, which overexpress a chimeric α-Esterase-7:EGFP gene, reveals important functions of α-Esterase-7 in insecticide tolerance, lipid metabolism and lifespan control. The presented first deletion mutant of any α-Esterase in the model insect D. melanogaster generated by gene targeting not only provides experimental evidence for the endogenous functions of this gene family. It also offers an entry point for in vivo structure-function analyses of α-Esterase-7, which is of central importance for naturally occurring insecticide resistance in wild populations of various dipteran insect species.
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Affiliation(s)
- Ruth Birner-Gruenberger
- Research Group Functional Proteomics, Institute of Pathology, and Proteomics Core Facility, Center of Medical Research, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
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30
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Etschmaier K, Becker T, Eichmann TO, Schweinzer C, Scholler M, Tam-Amersdorfer C, Poeckl M, Schuligoi R, Kober A, Chirackal Manavalan AP, Rechberger GN, Streith IE, Zechner R, Zimmermann R, Panzenboeck U. Adipose triglyceride lipase affects triacylglycerol metabolism at brain barriers. J Neurochem 2011; 119:1016-28. [PMID: 21951135 DOI: 10.1111/j.1471-4159.2011.07498.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Currently, little is known about the role of intracellular triacylglycerol (TAG) lipases in the brain. Adipose triglyceride lipase (ATGL) is encoded by the PNPLA2 gene and catalyzes the rate-limiting step of lipolysis. In this study, we investigated the effects of ATGL deficiency on brain lipid metabolism in vivo using an established knock-out mouse model (ATGL-ko). A moderate decrease in TAG hydrolase activity detected in ATGL-ko versus wild-type brain tissue was accompanied by a 14-fold increase in TAG levels and an altered composition of TAG-associated fatty acids in ATGL-ko brains. Oil Red O staining revealed a severe accumulation of neutral lipids associated to cerebrovascular cells and in distinct brain regions namely the ependymal cell layer and the choroid plexus along the ventricular system. In situ hybridization histochemistry identified ATGL mRNA expression in ependymal cells, the choroid plexus, pyramidal cells of the hippocampus, and the dentate gyrus. Our findings imply that ATGL is involved in brain fatty acid metabolism, particularly in regions mediating transport and exchange processes: the brain-CSF interface, the blood-CSF barrier, and the blood-brain barrier.
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Affiliation(s)
- Karoline Etschmaier
- Institute of Pathophysiology and Immunology, Medical University of Graz, Graz, Austria
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31
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Kretschmer N, Blunder M, Kunert O, Rechberger GN, Bauer R, Schuehly W. Cytotoxic furanogermacranolides from the flowers of Helianthus angustifolius. Planta Med 2011; 77:1912-1915. [PMID: 21674441 DOI: 10.1055/s-0031-1279994] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The dichloromethane extract of the flowers of Helianthus angustifolius L. (Asteraceae, Heliantheae) was investigated in vitro for its cytotoxic activity using human cancer cell lines: CCRF-CEM leukemia, MDA-MB-231 breast cancer, U251 glioblastoma, HCT 116 colon cancer cells, and the human lung fibroblast cell line MRC-5. Cytotoxicity-guided fractionation led to the isolation of four related heliangolide-type sesquiterpene lactones. The structures were elucidated by means of NMR spectroscopy and high-resolution mass spectrometry. Of the investigated compounds, 8-methacrylyl-4,15-iso-atriplicolide (1) showed the highest activity against all tested cancer cell lines with IC₅₀ values ranging from 0.26 ± 0.01 µM for CCRF-CEM cells to 4.22 ± 0.26 µM for MRC-5 cells.
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Affiliation(s)
- Nadine Kretschmer
- Department of Pharmacognosy, Institute of Pharmaceutical Sciences, Karl-Franzens-University Graz, Graz, Austria
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32
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Roullier C, Chollet-Krugler M, Pferschy-Wenzig EM, Maillard A, Rechberger GN, Legouin-Gargadennec B, Bauer R, Boustie J. Characterization and identification of mycosporines-like compounds in cyanolichens. Isolation of mycosporine hydroxyglutamicol from Nephroma laevigatum Ach. Phytochemistry 2011; 72:1348-1357. [PMID: 21550091 DOI: 10.1016/j.phytochem.2011.04.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 04/03/2011] [Accepted: 04/04/2011] [Indexed: 05/30/2023]
Abstract
Mycosporine-like compounds, comprising mycosporines and mycosporine-like amino acids (MAAs) are UV protecting secondary metabolites described in organisms such as fungi, algae, cyanobacteria or animals. Lichens however, were only poorly investigated for such constituents so far. Here, a method for the characterization of mycosporines and MAAs in purified aqueous extracts, involving HPTLC coupled to spectrophotodensitometry, HPLC-DAD-MS(n) and UPLC-HRMS analysis, is described. This optimized protocol was validated on three algae and one cyanolichen containing known MAAs and mycosporines, and then applied to 18 cyanolichen species. Analyses revealed the presence of five already described mycosporine-like compounds in the investigated species, including mycosporine serinol in Lichina and Peltigera species and mycosporine glutamicol in Degelia plumbea. Apart from that, eight unknown mycosporine-like compounds were detected and tentatively characterized on the basis of their DAD spectra and their MS(n) and HRMS data: two in the alga Porphyra dioica and six in cyanolichen species belonging to the genera Degelia, Nephroma and Stereocaulon. From Nephroma laevigatum, the mycosporine hydroxyglutamicol was preparatively isolated and identified through HRMS, 1D and 2D NMR spectroscopic data. The optimized analytical protocol allowed the characterization of mycosporine-like compounds in small amounts of material and confirmed the potential of cyanolichens as a source of mycosporine compounds. It should also be applicable to investigate lichen species with green algae photobionts for mycosporine-like compounds.
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Affiliation(s)
- Catherine Roullier
- Equipe PNSCM "Produits Naturels, Synthèses et Chimie Médicinale", UMR CNRS 6226, Faculté des Sciences Pharmaceutiques et Biologiques, Université de Rennes 1, 2 Av. du Pr. Léon Bernard, 35043 Rennes Cedex, France
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33
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Carmona-Gutiérrez D, Bauer MA, Ring J, Knauer H, Eisenberg T, Büttner S, Ruckenstuhl C, Reisenbichler A, Magnes C, Rechberger GN, Birner-Gruenberger R, Jungwirth H, Fröhlich KU, Sinner F, Kroemer G, Madeo F. The propeptide of yeast cathepsin D inhibits programmed necrosis. Cell Death Dis 2011; 2:e161. [PMID: 21593793 PMCID: PMC3122122 DOI: 10.1038/cddis.2011.43] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The lysosomal endoprotease cathepsin D (CatD) is an essential player in general protein turnover and specific peptide processing. CatD-deficiency is associated with neurodegenerative diseases, whereas elevated CatD levels correlate with tumor malignancy and cancer cell survival. Here, we show that the CatD ortholog of the budding yeast Saccharomyces cerevisiae (Pep4p) harbors a dual cytoprotective function, composed of an anti-apoptotic part, conferred by its proteolytic capacity, and an anti-necrotic part, which resides in the protein's proteolytically inactive propeptide. Thus, deletion of PEP4 resulted in both apoptotic and necrotic cell death during chronological aging. Conversely, prolonged overexpression of Pep4p extended chronological lifespan specifically through the protein's anti-necrotic function. This function, which triggered histone hypoacetylation, was dependent on polyamine biosynthesis and was exerted via enhanced intracellular levels of putrescine, spermidine and its precursor S-adenosyl-methionine. Altogether, these data discriminate two pro-survival functions of yeast CatD and provide first insight into the physiological regulation of programmed necrosis in yeast.
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34
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Pfeifer T, Buchebner M, Chandak PG, Patankar J, Kratzer A, Obrowsky S, Rechberger GN, Kadam RS, Kompella UB, Kostner GM, Kratky D, Levak-Frank S. Synthetic LXR agonist suppresses endogenous cholesterol biosynthesis and efficiently lowers plasma cholesterol. Curr Pharm Biotechnol 2011; 12:285-92. [PMID: 21190543 DOI: 10.2174/138920111794295774] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 06/13/2010] [Indexed: 11/22/2022]
Abstract
The liver X receptors (LXRs) are key regulators of genes involved in cholesterol homeostasis. Natural ligands and activators of LXRs are oxysterols. Numerous steroidal and non-steroidal synthetic LXR ligands are under development as potential drugs for individuals suffering from lipid disorders. N,N-dimethyl-3β-hydroxycholenamide (DMHCA) is a steroidal ligand of LXRs that exerts anti-atherogenic effects in apolipoprotein E-deficient mice without causing negative side effects such as liver steatosis or hypertriglyceridemia. In this report, we investigated the consequences of DMHCA treatment on cholesterol homeostasis in vivo and in vitro. Despite its hydrophobicity, DMHCA is readily absorbed by C57BL/6 mice and taken up by intestinal cells, the lung, heart and kidneys, but is undetectable in the brain. DMHCA significantly reduces cholesterol absorption and uptake in duodenum and jejunum of the small intestine and in turn leads to a reduction of plasma cholesterol by 24%. The most striking finding of this study is that DMHCA inhibited the enzyme 3β-hydroxysterol-Δ24-reductase resulting in an accumulation of desmosterol in the plasma and in feces. Thus, the reduction of plasma cholesterol was due to a block in the final step of cholesterol biosynthesis. Taken together, DMHCA is an interesting compound with properties distinct from other LXR ligands and might be used to study desmosterol-mediated effects in cells and tissues.
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Affiliation(s)
- Thomas Pfeifer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/3, Graz, Austria
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35
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Spirk S, Belaj F, Nieger M, Köfeler H, Rechberger GN, Pietschnig R. Exploring the AnionâCation Interaction inm-Terphenyltetrafluorosilicates by Using Multinuclear NMR Spectroscopy, X-ray Diffraction, and ICR-FT-MS. Chemistry 2009; 15:9521-9. [PMID: 19681072 DOI: 10.1002/chem.200900915] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Stefan Spirk
- Institut für Chemie, Karl-Franzens-Universität Graz, Schubertstrasse 1, 8010 Graz, Austria
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36
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Kienesberger PC, Lee D, Pulinilkunnil T, Brenner DS, Cai L, Magnes C, Koefeler HC, Streith IE, Rechberger GN, Haemmerle G, Flier JS, Zechner R, Kim YB, Kershaw EE. Adipose triglyceride lipase deficiency causes tissue-specific changes in insulin signaling. J Biol Chem 2009; 284:30218-29. [PMID: 19723629 DOI: 10.1074/jbc.m109.047787] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Triacylglycerol accumulation in insulin target tissues is associated with insulin resistance. Paradoxically, mice with global targeted deletion of adipose triglyceride lipase (ATGL), the rate-limiting enzyme in triacylglycerol hydrolysis, display improved glucose tolerance and insulin sensitivity despite triacylglycerol accumulation in multiple tissues. To determine the molecular mechanisms for this phenotype, ATGL-deficient (ATGL(-/-)) and wild-type mice were injected with saline or insulin (10 units/kg, intraperitoneally), and then phosphorylation and activities of key insulin-signaling proteins were determined in insulin target tissues (liver, adipose tissue, and muscle). Insulin signaling and/or glucose transport was also evaluated in isolated adipocytes and skeletal muscle ex vivo. In ATGL(-/-) mice, insulin-stimulated phosphatidylinositol 3-kinase and Akt activities as well as phosphorylation of critical residues of IRS1 (Tyr(P)-612) and Akt (Ser(P)-473) were increased in skeletal muscle in vivo. Insulin-stimulated phosphatidylinositol 3-kinase activity and total insulin receptor and insulin receptor substrate 1, but not other parameters, were also increased in white adipose tissue in vivo. In contrast, in vivo measures of insulin signaling were decreased in brown adipose tissue and liver. Interestingly, the enhanced components of insulin signaling identified in skeletal muscle and white adipose tissue in vivo and their expected downstream effects on glucose transport were not present ex vivo. ATGL deficiency altered intramyocellular lipids as well as serum factors known to influence insulin sensitivity. Thus, skeletal muscle, rather than other tissues, primarily contributes to enhanced insulin sensitivity in ATGL(-/-) mice in vivo despite triacylglycerol accumulation, and both local and systemic factors contribute to tissue-specific effects of global ATGL deficiency on insulin action.
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Affiliation(s)
- Petra C Kienesberger
- From the Institute of Molecular Biosciences, University of Graz, A-8010 Graz, Austria
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37
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Birner-Gruenberger R, Susani-Etzerodt H, Kollroser M, Rechberger GN, Hermetter A. Lipolytic and esterolytic activity-based profiling of murine liver. Proteomics 2008; 8:3645-56. [DOI: 10.1002/pmic.200800191] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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38
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Madl T, Sterk H, Mittelbach M, Rechberger GN. Tandem mass spectrometric analysis of a complex triterpene saponin mixture of Chenopodium quinoa. J Am Soc Mass Spectrom 2006; 17:795-806. [PMID: 16603377 DOI: 10.1016/j.jasms.2006.02.013] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 02/19/2006] [Accepted: 02/20/2006] [Indexed: 05/08/2023]
Abstract
A nano-HPLC electrospray ionization multi-stage tandem mass spectrometry (nLC-ESI-MS/MS) approach was applied to a complex crude triterpene saponin extract of Chenopodium quinoa seed coats. In ESI-MS/MS spectra of triterpene saponins, characteristic fragmentation reactions are observed and allow the determination of aglycones, saccharide sequences, compositions, and branching. Fragmentation of aglycones provided further structural information. The chemical complexity of the mixture was resolved by a complete profiling. Eighty-seven triterpene saponins comprising 19 reported and 68 novel components were identified and studied by MS. In addition to four reported, five novel triterpene aglycones were detected and characterized according to their fragmentation reactions in ESI-MS/MS and electron ionization mass spectrometry (EI-MS). As a novelty fragmentation pathways were proposed and analyzed based upon quantum chemical calculations using a hybrid Hartree-Fock density functional method. Accuracy of the assignment procedure was proven by isolation and structure determination of a novel compound. As the relative distribution and composition of saponins varies between different cultivars and soils, the presented strategy allows a rapid and complete analysis of Chenopodium quinoa saponin distribution and composition, and is particularly suitable for quality control and screening of extracts designated for pharmaceutical, agricultural, and industrial applications.
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Affiliation(s)
- Tobias Madl
- Department of Organic and Bioorganic Chemistry, Institute of Chemistry, Karl Franzens University, Graz, Austria.
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39
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Spirk S, Nieger M, Rechberger GN, Pietschnig R. Formation and structural characterization of a sterically protected silicic acid diester. Appl Organomet Chem 2006. [DOI: 10.1002/aoc.1117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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40
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Fauler G, Rechberger GN, Devrnja D, Erwa W, Plecko B, Kotanko P, Breunig F, Paschke E. Rapid determination of urinary globotriaosylceramide isoform profiles by electrospray ionization mass spectrometry using stearoyl-d35-globotriaosylceramide as internal standard. Rapid Commun Mass Spectrom 2005; 19:1499-506. [PMID: 15880667 DOI: 10.1002/rcm.1948] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Globotriaosylceramide is a neutral glycolipid containing the trihexoside Gal(alpha1-4)Gal(ss1-4)Glc(ss1-1') covalently bound to N-acylsphingosine. It was identified as the main storage substance in the kidney of patients with Fabry disease, an X-linked deficiency of lysosomal alpha-galactosidase A which can significantly be ameliorated by enzyme replacement therapy. Unlike hemizygote males, affected heterozygote females cannot be identified by enzyme assays and therefore may remain untreated. A quantitation of urinary globotriaosylceramides was proposed as an alternative method for their diagnosis. However, the required studies on physiological and pathological variations in the excretion of trihexosides so far have been prevented by a lack of suitable methods. A validated, robust and quick high-throughput method for the quantitative analysis of globotriaosylceramide isoforms using stable-isotope-dilution/internal standardization and electrospray ionization mass spectrometry (ESI-MS) was developed. An internal standard, stearoyl-d35-globotriaosylceramide, was synthesized by enzymatic coupling of d35-stearic acid to the corresponding lyso-ceramidetrihexoside. Glycolipid isoforms of high purity were obtained from a 5-mL urine portion by extraction on C18 solid-phase columns and a novel washing protocol. ESI-MS analysis was performed in full and neutral loss scan modes. Urinary trihexosyl- and some of the di- and monohexosylceramide isoforms can be quantified within a single experiment. All glycolipid isoforms were above detection limit in healthy male and female subjects (n = 63). Prominent elevations of tetracosanoyl-(C24:0 plus C24:1)-globotriaosylceramides were found in urines from female (>2.5-fold above normals) or male Fabry patients (>5.8-fold above normals), but not among controls. Globotriaosylceramide isoforms shall now be analyzed in Fabry patients, non-genetic kidney disease and healthy subjects to define the conditions for a safe diagnosis of heterozygotes.
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Affiliation(s)
- Guenter Fauler
- Department of Pediatrics, Medical University of Graz, Auenbruggerplatz 30, A-8036 Graz, Austria
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41
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Abstract
This review focuses on the advances in electron capture mass spectrometry. Electron-capture (EC) is a sensitive ionisation technique for mass spectrometry providing selectivity towards electrophoric compounds. Recent advances in instrumentation have led to a more widespread application of this method in biomedical and pharmaceutical analysis. After a brief introduction to EC-mass spectrometry (MS), potential targets for EC-MS analysis are defined and enhancement of sensitivity by electrophoric derivatisation is discussed. A wide range of applications is selected, including prostanoid analysis in biomedical systems (with the oxidative stress indicators isoprostanes) and the trace level analysis of endogenous low-molecular weight compounds. Application to the trace level gas chromatography-negative ion chemical ionization MS (GC-NICI-MS) analysis of complex glucuronides is also demonstrated, as well as a wide range of drugs analysed in human blood. The review should point out the versatility and unique sensitivity of the technique, making it useful for basic research in medicinal chemistry, as well as clinical diagnosis, pharmaceutical and toxicological applications.
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Affiliation(s)
- H J Leis
- University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, A-8036 Graz, Austria.
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42
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Leis HJ, Fauler G, Rechberger GN, Windischhofer W. Quantitative trace analysis of estriol in human plasma by negative ion chemical ionization gas chromatography-mass spectrometry using a deuterated internal standard. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 794:205-13. [PMID: 12954373 DOI: 10.1016/s1570-0232(03)00454-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A stable isotope dilution gas chromatography-mass spectrometry (GC-MS) assay for the trace level determination of estriol in human plasma is described. Negative ion chemical ionization (NICI) MS is used for highly specific detection. The method involves derivatization of the phenolic hydroxyl to the pentafluorobenzyl ether derivative and subsequent reaction of the remaining hydroxyls with heptafluorobutyric anhydride. This derivative allows detection of the strikingly abundant phenolate ion under NICI conditions. [2,4,17beta]-2H(3)-labeled estriol was used as an internal standard. For high-level measurements (>313 ng/l) plasma was directly derivatized by extractive alkylation followed by heptafluorobutylation prior to analysis. A rapid and simple sample work up procedure was elaborated for trace level determinations (>5 ng/l plasma) using solid-phase extraction on C(18) with an absolute recovery of 92.9%. For low-level measurements, the calibration curve was linear in the range of 5 to 625 ng/l (r=0.99993). Inter-assay analytical precisions (RSDs) were 1.29, 2.30 and 2.89% at 39, 156 and 650 ng/l plasma, respectively. For high-level measurements, calibration curve linearity was observed in the range of 0.313 to 20 microg/l (r=0.99998). Inter-assay analytical precisions (RSDs) were 5.17, 1.92, 2.57 and 2.74% at 0.313, 0.625, 2.5 and 10 microg/l plasma, respectively. Postmenopausal plasma was used for spiked plasma samples. Sensitivity and specificity of the presented method allows adequate determination of estriol in human plasma samples.
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Affiliation(s)
- Hans Jörg Leis
- University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, A-8036 Graz, Austria.
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Jörg Leis H, Windischhofer W, Rechberger GN, Fauler G. Synthesis of [(18)O(2)]valproic acid and its use as an internal standard for the quantitative measurement by gas chromatography-electron ionization mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 784:69-75. [PMID: 12504184 DOI: 10.1016/s1570-0232(02)00755-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A specific method for the quantitative determination of valproic acid in human plasma is presented. Valproate was extracted from acidified plasma by hexane extraction and converted to its trimethylsilyl derivative without sample concentration. The derivatives were analyzed without any further purification. Using gas chromatography-electron ionization mass spectrometry, diagnostic useful fragment ions at m/z 201 and 205 were obtained for valproic acid and [(18)O(2)]valproic acid internal standard, respectively. [(18)O(2)]Valproic acid was synthesized from unlabeled valproate by acid-catalyzed exchange reaction in H(2)(18)O. The method was validated in the expected concentration range of a pharmacokinetic study. Thus, calibration graphs were linear within a range of 0.47-120 microgram/ml plasma. Intra-day precision was 2.29% (0.47 microgram/ml), 2.93% (4 microgram/ml), 3.22% (20 microgram/ml) and 4.40% (80 microgram/ml), inter-day variability was found to be 1.49% (0.47 microgram/ml), 3.79% (20 microgram/ml), 2.74% (40 microgram/ml) and 3.03% (80 microgram/ml). Inter-day accuracy showed deviations of 1.94% (0.47 microgram/ml), 0.53% (4 microgram/ml), -0.32% (20 microgram/ml) and 0.06% (80 microgram/ml). The method is rugged and robust and has been applied to the batch analysis of valproate during pharmacokinetic profiling of the drug.
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Affiliation(s)
- Hans Jörg Leis
- University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, A-8036, Graz, Austria.
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Rechberger GN, Fauler G, Windischhofer W, Köfeler H, Erwa W, Leis HJ. Quantitative analysis of clindamycin in human plasma by liquid chromatography/electrospray ionisation tandem mass spectrometry using d1-N-ethylclindamycin as internal standard. Rapid Commun Mass Spectrom 2003; 17:135-139. [PMID: 12512092 DOI: 10.1002/rcm.887] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A new method for the quantitative analysis of clindamycin in human plasma by liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) is presented. Recently published methods possess a disadvantage because of their use of internal standards with extraction and ionisation properties different from those of clindamycin. To avoid these problems, d(1)-N-ethylclindamycin was synthesised for use as internal standard by N-demethylation and subsequent d(1)-N-ethylation. Plasma sample preparation was done by an easy and rapid liquid-liquid extraction using ethyl acetate. The method was validated in the expected concentration range for a pharmacokinetic study. Calibration graphs were linear within the range 0.05-3.2 microg/mL plasma. Intra-day precision was between 0.90% (2.8 microg/mL) and 3.25% (0.05 microg/mL), inter-day variability was found to be between 1.33% (0.7 microg/mL) and 2.60% (0.05 microg/mL). Inter-day accuracy showed deviations between 0.4% (0.05 microg/mL) and -4.8% (0.2 microg/mL). The method is simple and robust, and has been applied to the batch analysis of clindamycin during a pharmacokinetic study.
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Affiliation(s)
- Gerald N Rechberger
- University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, 8036 Graz, Austria
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Leis HJ, Rechberger GN, Fauler G, Windischhofer W. Enantioselective trace analysis of amphetamine in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry. Rapid Commun Mass Spectrom 2003; 17:569-575. [PMID: 12621619 DOI: 10.1002/rcm.949] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A method for the quantitative enantioselective analysis of amphetamine in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry (GC/NICI-MS) is presented. Five-fold deuterated analogues of both enantiomers were used as internal standard. Plasma sample preparation was performed by a rapid liquid-liquid extraction using n-hexane. Derivatization with (S)-(-)-N-(heptafluorobutyryl)prolyl chloride was accomplished directly in the n-hexane extract to avoid loss of amphetamine during sample concentration. The method was validated in the expected concentration range of 0.006 for a pharmacokinetic study. Calibration curves were linear within a range 0.006-50 ng/mL plasma. Precision and accuracy were acceptable over the entire calibration range. Baseline separation of the enantiomers was easily achieved on a 15-m nonchiral apolar column. The method is simple and robust, and has been applied to the batch analysis of amphetamine enantiomers.
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Affiliation(s)
- Hans-Jörg Leis
- University Children's Hospital, Division of Analytical Biochemistry and Mass Spectrometry, Auenbruggerplatz 30, 8036 Graz, Austria.
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