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Gegner HM, Naake T, Dugourd A, Müller T, Czernilofsky F, Kliewer G, Jäger E, Helm B, Kunze-Rohrbach N, Klingmüller U, Hopf C, Müller-Tidow C, Dietrich S, Saez-Rodriguez J, Huber W, Hell R, Poschet G, Krijgsveld J. Pre-analytical processing of plasma and serum samples for combined proteome and metabolome analysis. Front Mol Biosci 2022; 9:961448. [PMID: 36605986 PMCID: PMC9808085 DOI: 10.3389/fmolb.2022.961448] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/28/2022] [Indexed: 01/07/2023] Open
Abstract
Metabolomic and proteomic analyses of human plasma and serum samples harbor the power to advance our understanding of disease biology. Pre-analytical factors may contribute to variability and bias in the detection of analytes, especially when multiple labs are involved, caused by sample handling, processing time, and differing operating procedures. To better understand the impact of pre-analytical factors that are relevant to implementing a unified proteomic and metabolomic approach in a clinical setting, we assessed the influence of temperature, sitting times, and centrifugation speed on the plasma and serum metabolomes and proteomes from six healthy volunteers. We used targeted metabolic profiling (497 metabolites) and data-independent acquisition (DIA) proteomics (572 proteins) on the same samples generated with well-defined pre-analytical conditions to evaluate criteria for pre-analytical SOPs for plasma and serum samples. Time and temperature showed the strongest influence on the integrity of plasma and serum proteome and metabolome. While rapid handling and low temperatures (4°C) are imperative for metabolic profiling, the analyzed proteomics data set showed variability when exposed to temperatures of 4°C for more than 2 h, highlighting the need for compromises in a combined analysis. We formalized a quality control scoring system to objectively rate sample stability and tested this score using external data sets from other pre-analytical studies. Stringent and harmonized standard operating procedures (SOPs) are required for pre-analytical sample handling when combining proteomics and metabolomics of clinical samples to yield robust and interpretable data on a longitudinal scale and across different clinics. To ensure an adequate level of practicability in a clinical routine for metabolomics and proteomics studies, we suggest keeping blood samples up to 2 h on ice (4°C) prior to snap-freezing as a compromise between stability and operability. Finally, we provide the methodology as an open-source R package allowing the systematic scoring of proteomics and metabolomics data sets to assess the stability of plasma and serum samples.
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Affiliation(s)
- Hagen M. Gegner
- Centre for Organismal Studies (COS), Metabolomics Core Technology Platform, University of Heidelberg, Heidelberg, Germany
| | - Thomas Naake
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Aurélien Dugourd
- Bioquant, Faculty of Medicine, Institute for Computational Biomedicine, University of Heidelberg and Heidelberg University Hospital, Heidelberg, Germany
| | - Torsten Müller
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany,Division Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Felix Czernilofsky
- Department of Medicine V, Hematology, Oncology and Rheumatology, University of Heidelberg, Heidelberg, Germany
| | - Georg Kliewer
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany,Division Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Evelyn Jäger
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
| | - Barbara Helm
- Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nina Kunze-Rohrbach
- Centre for Organismal Studies (COS), Metabolomics Core Technology Platform, University of Heidelberg, Heidelberg, Germany
| | - Ursula Klingmüller
- Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Mannheim, Germany
| | - Carsten Müller-Tidow
- Department of Medicine V, Hematology, Oncology and Rheumatology, University of Heidelberg, Heidelberg, Germany
| | - Sascha Dietrich
- Department of Medicine V, Hematology, Oncology and Rheumatology, University of Heidelberg, Heidelberg, Germany
| | - Julio Saez-Rodriguez
- Bioquant, Faculty of Medicine, Institute for Computational Biomedicine, University of Heidelberg and Heidelberg University Hospital, Heidelberg, Germany
| | - Wolfgang Huber
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Rüdiger Hell
- Centre for Organismal Studies (COS), Metabolomics Core Technology Platform, University of Heidelberg, Heidelberg, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), Metabolomics Core Technology Platform, University of Heidelberg, Heidelberg, Germany,*Correspondence: Jeroen Krijgsveld, ; Gernot Poschet,
| | - Jeroen Krijgsveld
- Faculty of Medicine, University of Heidelberg, Heidelberg, Germany,Division Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany,*Correspondence: Jeroen Krijgsveld, ; Gernot Poschet,
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Andresen C, Boch T, Gegner HM, Mechtel N, Narr A, Birgin E, Rasbach E, Rahbari N, Trumpp A, Poschet G, Hübschmann D. Comparison of extraction methods for intracellular metabolomics of human tissues. Front Mol Biosci 2022; 9:932261. [PMID: 36090025 PMCID: PMC9461704 DOI: 10.3389/fmolb.2022.932261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022] Open
Abstract
Analyses of metabolic compounds inside cells or tissues provide high information content since they represent the endpoint of biological information flow and are a snapshot of the integration of many regulatory processes. However, quantification of the abundance of metabolites requires their careful extraction. We present a comprehensive study comparing ten extraction protocols in four human sample types (liver tissue, bone marrow, HL60, and HEK cells) aiming to detect and quantify up to 630 metabolites of different chemical classes. We show that the extraction efficiency and repeatability are highly variable across protocols, tissues, and chemical classes of metabolites. We used different quality metrics including the limit of detection and variability between replicates as well as the sum of concentrations as a global estimate of analytical repeatability of the extraction. The coverage of extracted metabolites depends on the used solvents, which has implications for the design of measurements of different sample types and metabolic compounds of interest. The benchmark dataset can be explored in an easy-to-use, interactive, and flexible online resource (R/shiny app MetaboExtract: http://www.metaboextract.shiny.dkfz.de) for context-specific selection of the optimal extraction method. Furthermore, data processing and conversion functionality underlying the shiny app are accessible as an R package: https://cran.r-project.org/package=MetAlyzer.
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Affiliation(s)
- Carolin Andresen
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Heidelberg, Germany
- Division of Stem Cells and Cancer, German Cancer Research Center and DKFZ-ZMBH Alliance, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Tobias Boch
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Heidelberg, Germany
- Division of Stem Cells and Cancer, German Cancer Research Center and DKFZ-ZMBH Alliance, Heidelberg, Germany
- Division of Personalized Medical Oncology, German Cancer Research Center, Heidelberg, Germany
- Department of Personalized Oncology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany
- DKFZ-Hector Cancer Institute at the University Medical Center Mannheim, Mannheim, Germany
| | - Hagen M. Gegner
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Nils Mechtel
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Andreas Narr
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Heidelberg, Germany
- Division of Stem Cells and Cancer, German Cancer Research Center and DKFZ-ZMBH Alliance, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Emrullah Birgin
- Department of Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Erik Rasbach
- Department of Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Nuh Rahbari
- Department of Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Trumpp
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Heidelberg, Germany
- Division of Stem Cells and Cancer, German Cancer Research Center and DKFZ-ZMBH Alliance, Heidelberg, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Daniel Hübschmann
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Heidelberg, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- Computational Oncology, Molecular Diagnostics Program, National Center for Tumor Diseases (NCT) Heidelberg and German Cancer Research Center (DKFZ), Heidelberg, Germany
- *Correspondence: Daniel Hübschmann,
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3
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Gegner HM, Mechtel N, Heidenreich E, Wirth A, Cortizo FG, Bennewitz K, Fleming T, Andresen C, Freichel M, Teleman AA, Kroll J, Hell R, Poschet G. Deep Metabolic Profiling Assessment of Tissue Extraction Protocols for Three Model Organisms. Front Chem 2022; 10:869732. [PMID: 35548679 PMCID: PMC9083328 DOI: 10.3389/fchem.2022.869732] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 02/04/2022] [Accepted: 04/05/2022] [Indexed: 12/12/2022] Open
Abstract
Metabolic profiling harbors the potential to better understand various disease entities such as cancer, diabetes, Alzheimer’s, Parkinson’s disease or COVID-19. To better understand such diseases and their intricate metabolic pathways in human studies, model animals are regularly used. There, standardized rearing conditions and uniform sampling strategies are prerequisites towards a successful metabolomic study that can be achieved through model organisms. Although metabolomic approaches have been employed on model organisms before, no systematic assessment of different conditions to optimize metabolite extraction across several organisms and sample types has been conducted. We address this issue using a highly standardized metabolic profiling assay analyzing 630 metabolites across three commonly used model organisms (Drosophila, mouse, and zebrafish) to find an optimal extraction protocol for various matrices. Focusing on parameters such as metabolite coverage, concentration and variance between replicates we compared seven extraction protocols. We found that the application of a combination of 75% ethanol and methyl tertiary-butyl ether (MTBE), while not producing the broadest coverage and highest concentrations, was the most reproducible extraction protocol. We were able to determine up to 530 metabolites in mouse kidney samples, 509 in mouse liver, 422 in zebrafish and 388 in Drosophila and discovered a core overlap of 261 metabolites in these four matrices. To enable other scientists to search for the most suitable extraction protocol in their experimental context and interact with this comprehensive data, we have integrated our data set in the open-source shiny app “MetaboExtract”. Hereby, scientists can search for metabolites or compound classes of interest, compare them across the different tested extraction protocols and sample types as well as find reference concentration values.
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Affiliation(s)
- Hagen M. Gegner
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Nils Mechtel
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Elena Heidenreich
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Angela Wirth
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Fabiola Garcia Cortizo
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Katrin Bennewitz
- European Center for Angioscience (ECAS), Department of Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Thomas Fleming
- Department of Internal Medicine I and Clinical Chemistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Carolin Andresen
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM GGmbH), Heidelberg, Germany
- Division of Stem Cells and Cancer, Deutsches Krebsforschungszentrum (DKFZ) and DKFZ-ZMBH Alliance, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Aurelio A. Teleman
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jens Kroll
- European Center for Angioscience (ECAS), Department of Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Rüdiger Hell
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
- *Correspondence: Gernot Poschet,
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Rädecker N, Pogoreutz C, Gegner HM, Cárdenas A, Perna G, Geißler L, Roth F, Bougoure J, Guagliardo P, Struck U, Wild C, Pernice M, Raina JB, Meibom A, Voolstra CR. Heat stress reduces the contribution of diazotrophs to coral holobiont nitrogen cycling. ISME J 2021; 16:1110-1118. [PMID: 34857934 PMCID: PMC8941099 DOI: 10.1038/s41396-021-01158-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 12/22/2022]
Abstract
Efficient nutrient cycling in the coral-algal symbiosis requires constant but limited nitrogen availability. Coral-associated diazotrophs, i.e., prokaryotes capable of fixing dinitrogen, may thus support productivity in a stable coral-algal symbiosis but could contribute to its breakdown when overstimulated. However, the effects of environmental conditions on diazotroph communities and their interaction with other members of the coral holobiont remain poorly understood. Here we assessed the effects of heat stress on diazotroph diversity and their contribution to holobiont nutrient cycling in the reef-building coral Stylophora pistillata from the central Red Sea. In a stable symbiotic state, we found that nitrogen fixation by coral-associated diazotrophs constitutes a source of nitrogen to the algal symbionts. Heat stress caused an increase in nitrogen fixation concomitant with a change in diazotroph communities. Yet, this additional fixed nitrogen was not assimilated by the coral tissue or the algal symbionts. We conclude that although diazotrophs may support coral holobiont functioning under low nitrogen availability, altered nutrient cycling during heat stress abates the dependence of the coral host and its algal symbionts on diazotroph-derived nitrogen. Consequently, the role of nitrogen fixation in the coral holobiont is strongly dependent on its nutritional status and varies dynamically with environmental conditions.
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Affiliation(s)
- Nils Rädecker
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. .,Department of Biology, University of Konstanz, Konstanz, Germany. .,Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Claudia Pogoreutz
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Department of Biology, University of Konstanz, Konstanz, Germany
| | - Hagen M Gegner
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Metabolomics Core Technology Platform, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Anny Cárdenas
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Department of Biology, University of Konstanz, Konstanz, Germany
| | - Gabriela Perna
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Department of Biology, University of Konstanz, Konstanz, Germany
| | - Laura Geißler
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Florian Roth
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Baltic Sea Centre, Stockholm University, Stockholm, Sweden.,Faculty of Biological and Environmental Sciences, Tvärminne Zoological Station, University of Helsinki, Helsinki, Finland
| | - Jeremy Bougoure
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth, WA, Australia
| | - Paul Guagliardo
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth, WA, Australia
| | - Ulrich Struck
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany.,Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
| | - Christian Wild
- Faculty of Biology and Chemistry, Marine Ecology Department, University of Bremen, Bremen, Germany
| | - Mathieu Pernice
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Jean-Baptiste Raina
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Anders Meibom
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Center for Advanced Surface Analysis, Institute of Earth Sciences, Université de Lausanne, Lausanne, Switzerland
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Department of Biology, University of Konstanz, Konstanz, Germany
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Buitrago-López C, Mariappan KG, Cárdenas A, Gegner HM, Voolstra CR. The Genome of the Cauliflower Coral Pocillopora verrucosa. Genome Biol Evol 2021; 12:1911-1917. [PMID: 32857844 PMCID: PMC7594246 DOI: 10.1093/gbe/evaa184] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Climate change and ocean warming threaten the persistence of corals worldwide. Genomic resources are critical to study the evolutionary trajectory, adaptive potential, and genetic distinctiveness of coral species. Here, we provide a reference genome of the cauliflower coral Pocillopora verrucosa, a broadly prevalent reef-building coral with important ecological roles in the maintenance of reefs across the Red Sea, the Indian Ocean, and the Pacific Ocean. The genome has an assembly size of 380,505,698 bp with a scaffold N50 of 333,696 bp and a contig N50 of 75,704 bp. The annotation of the assembled genome returned 27,439 gene models of which 89.88% have evidence of transcription from RNA-Seq data and 97.87% show homology to known genes. A high proportion of the genome (41.22%) comprised repetitive elements in comparison to other cnidarian genomes, in particular in relation to the small genome size of P. verrucosa.
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Affiliation(s)
- Carol Buitrago-López
- Red Sea Research Center, Division of Biological BESE, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Kiruthiga G Mariappan
- Red Sea Research Center, Division of Biological BESE, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Germany
| | - Hagen M Gegner
- Red Sea Research Center, Division of Biological BESE, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Centre for Organismal Studies (COS), University of Heidelberg, Germany
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological BESE, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Department of Biology, University of Konstanz, Germany
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Mohapatra SR, Sadik A, Sharma S, Poschet G, Gegner HM, Lanz TV, Lucarelli P, Klingmüller U, Platten M, Heiland I, Opitz CA. Hypoxia Routes Tryptophan Homeostasis Towards Increased Tryptamine Production. Front Immunol 2021; 12:590532. [PMID: 33679737 PMCID: PMC7933006 DOI: 10.3389/fimmu.2021.590532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 08/01/2020] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
The liver is the central hub for processing and maintaining homeostatic levels of dietary nutrients especially essential amino acids such as tryptophan (Trp). Trp is required not only to sustain protein synthesis but also as a precursor for the production of NAD, neurotransmitters and immunosuppressive metabolites. In light of these roles of Trp and its metabolic products, maintaining homeostatic levels of Trp is essential for health and well-being. The liver regulates global Trp supply by the immunosuppressive enzyme tryptophan-2,3-dioxygenase (TDO2), which degrades Trp down the kynurenine pathway (KP). In the current study, we show that isolated primary hepatocytes when exposed to hypoxic environments, extensively rewire their Trp metabolism by reducing constitutive Tdo2 expression and differentially regulating other Trp pathway enzymes and transporters. Mathematical modelling of Trp metabolism in liver cells under hypoxia predicted decreased flux through the KP while metabolic flux through the tryptamine branch significantly increased. In line, the model also revealed an increased accumulation of tryptamines under hypoxia, at the expense of kynurenines. Metabolic measurements in hypoxic hepatocytes confirmed the predicted reduction in KP metabolites as well as accumulation of tryptamine. Tdo2 expression in cultured primary hepatocytes was reduced upon hypoxia inducible factor (HIF) stabilisation by dimethyloxalylglycine (DMOG), demonstrating that HIFs are involved in the hypoxic downregulation of hepatic Tdo2. DMOG abrogated hepatic luciferase signals in Tdo2 reporter mice, indicating that HIF stability also recapitulates hypoxic rewiring of Trp metabolism in vivo. Also in WT mice HIF stabilization drove homeostatic Trp metabolism away from the KP towards enhanced tryptamine production, leading to enhanced levels of tryptamine in liver, serum and brain. As tryptamines are the most potent hallucinogens known, the observed upregulation of tryptamine in response to hypoxic exposure of hepatocytes may be involved in the generation of hallucinations occurring at high altitude. KP metabolites are known to activate the aryl hydrocarbon receptor (AHR). The AHR-activating properties of tryptamines may explain why immunosuppressive AHR activity is maintained under hypoxia despite downregulation of the KP. In summary our results identify hypoxia as an important factor controlling Trp metabolism in the liver with possible implications for immunosuppressive AHR activation and mental disturbances.
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Affiliation(s)
- Soumya R. Mohapatra
- DKTK Brain Cancer Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ahmed Sadik
- DKTK Brain Cancer Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Suraj Sharma
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Gernot Poschet
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Hagen M. Gegner
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Tobias V. Lanz
- DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences (MCTN), Heidelberg University, Mannheim, Germany
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Philippe Lucarelli
- Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ursula Klingmüller
- Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Michael Platten
- DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences (MCTN), Heidelberg University, Mannheim, Germany
| | - Ines Heiland
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Christiane A. Opitz
- DKTK Brain Cancer Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Neurology Clinic and National Center for Tumor Diseases, University Hospital of Heidelberg, Heidelberg, Germany
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7
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Gegner HM, Rädecker N, Ochsenkühn M, Barreto MM, Ziegler M, Reichert J, Schubert P, Wilke T, Voolstra CR. High levels of floridoside at high salinity link osmoadaptation with bleaching susceptibility in the cnidarian-algal endosymbiosis. Biol Open 2019; 8:8/12/bio045591. [PMID: 31843766 PMCID: PMC6918757 DOI: 10.1242/bio.045591] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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] [Indexed: 01/01/2023] Open
Abstract
Coral reefs are in global decline mainly due to increasing sea surface temperatures triggering coral bleaching. Recently, high salinity has been linked to increased thermotolerance and decreased bleaching in the sea anemone coral model Aiptasia. However, the underlying processes remain elusive. Using two Aiptasia host–endosymbiont pairings, we induced bleaching at different salinities and show reduced reactive oxygen species (ROS) release at high salinities, suggesting a role of osmoadaptation in increased thermotolerance. A subsequent screening of osmolytes revealed that this effect was only observed in algal endosymbionts that produce 2-O-glycerol-α-D-galactopyranoside (floridoside), an osmolyte capable of scavenging ROS. This result argues for a mechanistic link between osmoadaptation and thermotolerance, mediated by ROS-scavenging osmolytes (e.g., floridoside). This sheds new light on the putative mechanisms underlying the remarkable thermotolerance of corals from water bodies with high salinity such as the Red Sea or Persian/Arabian Gulf and holds implications for coral thermotolerance under climate change. This article has an associated First Person interview with the first author of the paper. Summary: Using the coral model Aiptasia, we show increased thermotolerance at high salinities, concomitant with a reduced reactive oxygen species (ROS) release by algal endosymbionts. This suggests a mechanistic link between osmoadaptation and thermotolerance, mediated by ROS-scavenging osmolytes.
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Affiliation(s)
- Hagen M Gegner
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Nils Rädecker
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Michael Ochsenkühn
- Division of Science and Engineering, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates
| | - Marcelle M Barreto
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Maren Ziegler
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia.,Department of Animal Ecology & Systematics, Justus Liebig University, 35390 Giessen, Germany
| | - Jessica Reichert
- Department of Animal Ecology & Systematics, Justus Liebig University, 35390 Giessen, Germany
| | - Patrick Schubert
- Department of Animal Ecology & Systematics, Justus Liebig University, 35390 Giessen, Germany
| | - Thomas Wilke
- Department of Animal Ecology & Systematics, Justus Liebig University, 35390 Giessen, Germany
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia .,Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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8
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Abstract
The endosymbiosis between dinoflagellate algae of the genus Symbiodinium and stony corals provides the foundation of coral reef ecosystems. Coral bleaching, the expulsion of endosymbionts from the coral host tissue as a consequence of heat or light stress, poses a threat to reef ecosystem functioning on a global scale. Hence, a better understanding of the factors contributing to heat stress susceptibility and tolerance is needed. In this regard, some of the most thermotolerant corals live in particularly saline habitats, but possible effects of high salinity on thermotolerance in corals are anecdotal. Here we test the hypothesis that high salinity may lead to increased thermotolerance. We conducted a heat stress experiment at low, intermediate, and high salinities using a set of host-endosymbiont combinations of the coral model Aiptasia. As expected, all host-endosymbiont combinations showed reduced photosynthetic efficiency and endosymbiont loss during heat stress, but the severity of bleaching was significantly reduced with increasing salinities for one of the host-endosymbiont combinations. Our results show that higher salinities can convey increased thermotolerance in Aiptasia, although this effect seems to be dependent on the particular host strain and/or associated symbiont type. This finding may help explain the extraordinarily high thermotolerance of corals in high salinity environments, such as the Red Sea and the Persian/Arabian Gulf, and provides novel insight regarding factors that contribute to thermotolerance. Since our results are based on a salinity effect in symbiotic sea anemones, it remains to be determined whether this salinity effect can also be observed in stony corals. Summary: High salinity can be a factor contributing to increased cnidarian thermal tolerance, as indicated by reduced algal endosymbiont loss and reduced photosynthetic impairment in the sea anemone Aiptasia.
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Affiliation(s)
- Hagen M Gegner
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Maren Ziegler
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Nils Rädecker
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Carol Buitrago-López
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Manuel Aranda
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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