21 results on '"von Gerichten J"'
Search Results
2. Short-term changes in human metabolism following a 5-hour delay of the light-dark and behavioural cycle.
- Author
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Flanagan, A., Ruddick-Collins, L.C., Fielding, B., Middleton, B., von Gerichten, J., Short, M., Revell, V., Mendis, J., Mayer, C.D., Morgan, P.J., Johnstone, A.M., and Johnston, J.D.
- Abstract
The circadian timing system regulates many aspects of metabolic physiology, including the postprandial response to meals(1). Experimental inversion of circadian and behavioural rhythms by 12 hours adversely effects markers of metabolic health(2). We investigated effects of a more modest 5hour delay in behavioural cycles. Fourteen participants completed an 8-day in-patient laboratory protocol, with controlled sleepwake opportunities, light-dark cycles, and diet. The 5-hour delay in behavioural cycles was induced by delaying sleep opportunity. We measured: melatonin to confirm central circadian phase; fasting markers and postprandial metabolism; energy expenditure; subjective sleepiness; and appetite, throughout the waking period. After the phase delay, there was slower gastric emptying at breakfast, lower fasting plasma glucose, higher postprandial plasma glucose and triglycerides, and lower thermic effect of feeding. Any changes were abolished or attenuated within 48-72 hours. Further, we show no difference in 16 h waking energy expenditure. These data extend our previous findings, which showed no time-of-day effect on energy expenditure in healthy adults. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. TLR9-mediated dendritic cell activation uncovers mammalian ganglioside species with specific ceramide backbones that activate invariant natural killer T cells
- Author
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Paget, C, Deng, S, Soulard, D, Priestman, D, Speca, S, von Gerichten, J, Speak, A, Saroha, A, Pewzner-Jung, Y, Futerman, A, Mallevaey, T, Faveeuw, C, Gu, X, Platt, F, Sandhoff, R, Trottein, F, Centre d’Etude des Pathologies Respiratoires (CEPR), UMR 1100 [CEPR], Centre d’Infection et d’Immunité de Lille - INSERM U 1019 - UMR 9017 - UMR 8204 [CIIL], Centre d’Etude des Pathologies Respiratoires (CEPR), UMR 1100 (CEPR), Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre d’Infection et d’Immunité de Lille - INSERM U 1019 - UMR 9017 - UMR 8204 (CIIL), Centre National de la Recherche Scientifique (CNRS)-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-Université de Lille-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Brigham Young University (BYU), S&D Lipopharma LLC, University of Oxford [Oxford], Lille Inflammation Research International Center - U 995 (LIRIC), Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Institut Pasteur de Lille, Universität Heidelberg [Heidelberg], German Cancer Research Center - Deutsches Krebsforschungszentrum [Heidelberg] (DKFZ), Weizmann Institute of Science [Rehovot, Israël], University of Toronto, Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-Centre National de la Recherche Scientifique (CNRS), Pathologies Respiratoires : Protéolyse et Aérosolthérapie, Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), University of Oxford, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Heidelberg University, TROTTEIN, François, and CHU Lille
- Subjects
Male ,[SDV.IMM] Life Sciences [q-bio]/Immunology ,Physiology ,QH301-705.5 ,Cell Lines ,Immune Cells ,[SDV]Life Sciences [q-bio] ,Immunology ,Glycobiology ,Antigen-Presenting Cells ,Bone Marrow Cells ,Ceramides ,Real-Time Polymerase Chain Reaction ,Research and Analysis Methods ,Biochemistry ,Immune Receptors ,Glycosphingolipids ,Animal Cells ,Gangliosides ,Immune Physiology ,Medicine and Health Sciences ,Animals ,G(M3) Ganglioside ,Antigens ,Biology (General) ,Sphingolipids ,Hybridomas ,Immune System Proteins ,Biology and Life Sciences ,Proteins ,Dendritic Cells ,Cell Biology ,Lipids ,[SDV] Life Sciences [q-bio] ,Mice, Inbred C57BL ,T Cell Receptors ,Toll-Like Receptor 9 ,[SDV.IMM]Life Sciences [q-bio]/Immunology ,Natural Killer T-Cells ,lipids (amino acids, peptides, and proteins) ,Biological Cultures ,Interferons ,Antigens, CD1d ,Glycolipids ,Cellular Types ,Research Article ,Signal Transduction - Abstract
CD1d-restricted invariant natural killer T (iNKT) cells represent a heterogeneous population of lipid-reactive T cells that are involved in many immune responses, mediated through T-cell receptor (TCR)–dependent and/or independent activation. Although numerous microbial lipid antigens (Ags) have been identified, several lines of evidence have suggested the existence of relevant Ags of endogenous origin. However, the identification of their precise nature as well as the molecular mechanisms involved in their generation are still highly controversial and ill defined. Here, we identified two mammalian gangliosides—namely monosialoganglioside GM3 and disialoganglioside GD3—as endogenous activators for mouse iNKT cells. These glycosphingolipids are found in Toll-like receptor-stimulated dendritic cells (DC) as several species varying in their N-acyl fatty chain composition. Interestingly, their ability to activate iNKT cells is highly dependent on the ceramide backbone structure. Thus, both synthetic GM3 and GD3 comprising a d18:1-C24:1 ceramide backbone were able to activate iNKT cells in a CD1d-dependent manner. GM3 and GD3 are not directly recognized by the iNKT TCR and required the Ag presenting cell intracellular machinery to reveal their antigenicity. We propose a new concept in which iNKT cells can rapidly respond to pre-existing self-molecules after stress-induced structural changes in CD1d-expressing cells. Moreover, these gangliosides conferred partial protection in the context of bacterial infection. Thus, this report identified new biologically relevant lipid self-Ags for iNKT cells., Although the existence of self-antigens for invariant Natural Killer T (iNKT) cells is widely accepted, their precise nature remains a matter of debate. This study shows that two mammalian ganglioside species activate iNKT cells in a CD1d-dependent manner., Author summary Invariant natural killer T (iNKT) cells are a population of unconventional T lymphocytes that activate rapidly during inflammation due to their innate-like features. They are unconventional since they do not react to peptidic antigens (Ags) presented by classical major histocompatibility complex (MHC) molecules; instead, they recognize lipid-based Ags in the context of the MHC class I-like molecule CD1d. While numerous Ags of microbial origins have been described, their endogenous Ags are far less understood and remain a matter of strong debate. Here, we report that engagement of an innate receptor on the Ag-presenting cells leads to modulation of their lipid metabolism. This results in an enrichment of particular glycosphingolipid species that differ in both the nonpolar tail and polar head structures. Among those, two species have the potential to activate iNKT cells in a CD1d-dependent manner after further intracellular modifications. Based on these data, we propose a concept that iNKT cells can rapidly respond to pre-existing self-molecules after stress-induced changes in CD1d-expressing cells. Given the presence of closely related molecules in some pathological conditions such as cancer, it will be interesting to evaluate the biological relevance of these Ags in disease states.
- Published
- 2019
4. How does polyunsaturated fatty acid biosynthesis regulate T‐lymphocyte function?
- Author
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Fielding, B. A., primary, Calder, P. C., additional, Irvine, N. A., additional, Miles, E. A., additional, Lillycrop, K. A., additional, von Gerichten, J., additional, and Burdge, G. C., additional
- Published
- 2019
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5. Challenges in Lipidomics Biomarker Identification: Avoiding the Pitfalls and Improving Reproducibility.
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von Gerichten J, Saunders K, Bailey MJ, Gethings LA, Onoja A, Geifman N, and Spick M
- Abstract
Identification of features with high levels of confidence in liquid chromatography-mass spectrometry (LC-MS) lipidomics research is an essential part of biomarker discovery, but existing software platforms can give inconsistent results, even from identical spectral data. This poses a clear challenge for reproducibility in biomarker identification. In this work, we illustrate the reproducibility gap for two open-access lipidomics platforms, MS DIAL and Lipostar, finding just 14.0% identification agreement when analyzing identical LC-MS spectra using default settings. Whilst the software platforms performed more consistently using fragmentation data, agreement was still only 36.1% for MS
2 spectra. This highlights the critical importance of validation across positive and negative LC-MS modes, as well as the manual curation of spectra and lipidomics software outputs, in order to reduce identification errors caused by closely related lipids and co-elution issues. This curation process can be supplemented by data-driven outlier detection in assessing spectral outputs, which is demonstrated here using a novel machine learning approach based on support vector machine regression combined with leave-one-out cross-validation. These steps are essential to reduce the frequency of false positive identifications and close the reproducibility gap, including between software platforms, which, for downstream users such as bioinformaticians and clinicians, can be an underappreciated source of biomarker identification errors.- Published
- 2024
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6. Single-Cell Untargeted Lipidomics Using Liquid Chromatography and Data-Dependent Acquisition after Live Cell Selection.
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von Gerichten J, Saunders KDG, Kontiza A, Newman CF, Mayson G, Beste DJV, Velliou E, Whetton AD, and Bailey MJ
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- Humans, Animals, Chromatography, Liquid, Mice, Cell Line, Tumor, Mass Spectrometry, Macrophages metabolism, Macrophages cytology, Single-Cell Analysis, Lipidomics methods, Lipids analysis, Lipids chemistry
- Abstract
We report the development and validation of an untargeted single-cell lipidomics method based on microflow chromatography coupled to a data-dependent mass spectrometry method for fragmentation-based identification of lipids. Given the absence of single-cell lipid standards, we show how the methodology should be optimized and validated using a dilute cell extract. The methodology is applied to dilute pancreatic cancer and macrophage cell extracts and standards to demonstrate the sensitivity requirements for confident assignment of lipids and classification of the cell type at the single-cell level. The method is then coupled to a system that can provide automated sampling of live, single cells into capillaries under microscope observation. This workflow retains the spatial information and morphology of cells during sampling and highlights the heterogeneity in lipid profiles observed at the single-cell level. The workflow is applied to show changes in single-cell lipid profiles as a response to oxidative stress, coinciding with expanded lipid droplets. This demonstrates that the workflow is sufficiently sensitive to observing changes in lipid profiles in response to a biological stimulus. Understanding how lipids vary in single cells will inform future research into a multitude of biological processes as lipids play important roles in structural, biophysical, energy storage, and signaling functions.
- Published
- 2024
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7. Single-Cell Lipidomics Using Analytical Flow LC-MS Characterizes the Response to Chemotherapy in Cultured Pancreatic Cancer Cells.
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Saunders KDG, von Gerichten J, Lewis HM, Gupta P, Spick M, Costa C, Velliou E, and Bailey MJ
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- Humans, Chromatography, Liquid, Lipids analysis, Tandem Mass Spectrometry, Gemcitabine, Pancreatic Neoplasms, Lipidomics methods, Pancreatic Neoplasms drug therapy
- Abstract
In this work, we demonstrate the development and first application of nanocapillary sampling followed by analytical flow liquid chromatography-mass spectrometry for single-cell lipidomics. Around 260 lipids were tentatively identified in a single cell, demonstrating remarkable sensitivity. Human pancreatic ductal adenocarcinoma cells (PANC-1) treated with the chemotherapeutic drug gemcitabine can be distinguished from controls solely on the basis of their single-cell lipid profiles. Notably, the relative abundance of LPC(0:0/16:0) was significantly affected in gemcitabine-treated cells, in agreement with previous work in bulk. This work serves as a proof of concept that live cells can be sampled selectively and then characterized using automated and widely available analytical workflows, providing biologically relevant outputs.
- Published
- 2023
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8. Meta-Analysis of COVID-19 Metabolomics Identifies Variations in Robustness of Biomarkers.
- Author
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Onoja A, von Gerichten J, Lewis HM, Bailey MJ, Skene DJ, Geifman N, and Spick M
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- Humans, Reproducibility of Results, Metabolomics methods, Biomarkers metabolism, Pandemics, COVID-19 diagnosis
- Abstract
The global COVID-19 pandemic resulted in widespread harms but also rapid advances in vaccine development, diagnostic testing, and treatment. As the disease moves to endemic status, the need to identify characteristic biomarkers of the disease for diagnostics or therapeutics has lessened, but lessons can still be learned to inform biomarker research in dealing with future pathogens. In this work, we test five sets of research-derived biomarkers against an independent targeted and quantitative Liquid Chromatography-Mass Spectrometry metabolomics dataset to evaluate how robustly these proposed panels would distinguish between COVID-19-positive and negative patients in a hospital setting. We further evaluate a crowdsourced panel comprising the COVID-19 metabolomics biomarkers most commonly mentioned in the literature between 2020 and 2023. The best-performing panel in the independent dataset-measured by F1 score (0.76) and AUROC (0.77)-included nine biomarkers: lactic acid, glutamate, aspartate, phenylalanine, β-alanine, ornithine, arachidonic acid, choline, and hypoxanthine. Panels comprising fewer metabolites performed less well, showing weaker statistical significance in the independent cohort than originally reported in their respective discovery studies. Whilst the studies reviewed here were small and may be subject to confounders, it is desirable that biomarker panels be resilient across cohorts if they are to find use in the clinic, highlighting the importance of assessing the robustness and reproducibility of metabolomics analyses in independent populations.
- Published
- 2023
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9. Exogenous tetracosahexaenoic acid modifies the fatty acid composition of human primary T lymphocytes and Jurkat T cell leukemia cells contingent on cell type.
- Author
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Irvine NA, West AL, Von Gerichten J, Miles EA, Lillycrop KA, Calder PC, Fielding BA, and Burdge GC
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- Animals, Humans, Jurkat Cells, Docosahexaenoic Acids pharmacology, Mammals, Fatty Acids pharmacology, Fatty Acids metabolism, Leukemia, T-Cell
- Abstract
Tetracosahexaenoic acid (24:6ω-3) is an intermediate in the conversion of 18:3ω-3 to 22:6ω-3 in mammals. There is limited information about whether cells can assimilate and metabolize exogenous 24:6ω-3. This study compared the effect of incubation with 24:6ω-3 on the fatty acid composition of two related cell types, primary CD3
+ T lymphocytes and Jurkat T cell leukemia, which differ in the integrity of the polyunsaturated fatty acid (PUFA) biosynthesis pathway. 24:6ω-3 was only detected in either cell type when cells were incubated with 24:6ω-3. Incubation with 24:6ω-3 induced similar increments in the amount of 22:6ω-3 in both cell types and modified the homeoviscous adaptations fatty acid composition induced by activation of T lymphocytes. The effect of incubation with 18:3ω-3 compared to 24:6ω-3 on the increment in 22:6ω-3 was tested in Jurkat cells because primary T cells cannot convert 18:3ω-3 to 22:6ω-3. The increment in the 22:6ω-3 content of Jurkat cells incubated with 24:6ω-3 was 19.5-fold greater than that of cells incubated with 18:3ω-3. Acyl-coA oxidase siRNA knockdown decreased the amount of 22:6ω-3 and increased the amount of 24:6ω-3 in Jurkat cells. These findings show exogenous 24:6ω-3 can be incorporated into primary human T lymphocytes and Jurkat cells and induces changes in fatty acid composition consistent with its conversion to 22:6ω-3 via a mechanism involving peroxisomal β-oxidation that is regulated independently from the integrity of the upstream PUFA synthesis pathway. One further implication is that consuming 24:6ω-3 may be an effective alternative means of achieving health benefits attributed to 20:5ω-3 and 22:6ω-3., (© 2023 The Authors. Lipids published by Wiley Periodicals LLC on behalf of AOCS.)- Published
- 2023
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10. Oxylipin secretion by human CD3 + T lymphocytes in vitro is modified by the exogenous essential fatty acid ratio and life stage.
- Author
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von Gerichten J, West AL, Irvine NA, Miles EA, Calder PC, Lillycrop KA, Burdge GC, and Fielding BA
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- Adult, Humans, T-Lymphocytes, Mitogens, Fatty Acids, Essential, Linoleic Acid, Oxylipins, Fatty Acids, Omega-3
- Abstract
Immune function changes across the life stages; for example, senior adults exhibit a tendency towards a weaker cell-mediated immune response and a stronger inflammatory response than younger adults. This might be partly mediated by changes in oxylipin synthesis across the life course. Oxylipins are oxidation products of polyunsaturated fatty acids (PUFAs) that modulate immune function and inflammation. A number of PUFAs are precursors to oxylipins, including the essential fatty acids (EFAs) linoleic acid (LA) and α-linolenic acid (ALA). LA and ALA are also substrates for synthesis of longer chain PUFAs. Studies with stable isotopes have shown that the relative amounts of LA and ALA can influence their partitioning by T lymphocytes between conversion to longer chain PUFAs and to oxylipins. It is not known whether the relative availability of EFA substrates influences the overall pattern of oxylipin secretion by human T cells or if this changes across the life stages. To address this, the oxylipin profile was determined in supernatants from resting and mitogen activated human CD3
+ T cell cultures incubated in medium containing an EFA ratio of either 5:1 or 8:1 (LA : ALA). Furthermore, oxylipin profiles in supernatants of T cells from three life stages, namely fetal (derived from umbilical cord blood), adults and seniors, treated with the 5:1 EFA ratio were determined. The extracellular oxylipin profiles were affected more by the EFA ratio than mitogen stimulation such that n-3 PUFA-derived oxylipin concentrations were higher with the 5:1 EFA ratio than the 8:1 ratio, possibly due to PUFA precursor competition for lipoxygenases. 47 oxylipin species were measured in all cell culture supernatants. Extracellular oxylipin concentrations were generally higher for fetal T cells than for T cells from adult and senior donors, although the composition of oxylipins was similar across the life stages. The contribution of oxylipins towards an immunological phenotype might be due to the capacity of T cells to synthesize oxylipins rather than the nature of the oxylipins produced., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 von Gerichten, West, Irvine, Miles, Calder, Lillycrop, Burdge and Fielding.)- Published
- 2023
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11. Nanocapillary sampling coupled to liquid chromatography mass spectrometry delivers single cell drug measurement and lipid fingerprints.
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Lewis HM, Gupta P, Saunders KDG, Briones S, von Gerichten J, Townsend PA, Velliou E, Beste DJV, Cexus O, Webb R, and Bailey MJ
- Subjects
- Animals, Mass Spectrometry methods, Chromatography, Liquid methods, Lipids, Mammals
- Abstract
This work describes the development of a new approach to measure drug levels and lipid fingerprints in single living mammalian cells. Nanocapillary sampling is an approach that enables the selection and isolation of single living cells under microscope observation. Here, live single cell nanocapillary sampling is coupled to liquid chromatography for the first time. This allows molecular species to be separated prior to ionisation and improves measurement precision of drug analytes. The efficiency of transferring analytes from the sampling capillary into a vial was optimised in this work. The analysis was carried out using standard flow liquid chromatography coupled to widely available mass spectrometry instrumentation, highlighting opportunities for widespread adoption. The method was applied to 30 living cells, revealing cell-to-cell heterogeneity in the uptake of different drug molecules. Using this system, we detected 14-158 lipid features per single cell, revealing the association between bedaquiline uptake and lipid fingerprints.
- Published
- 2023
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12. Fatty acid composition and metabolic partitioning of α-linolenic acid are contingent on life stage in human CD3 + T lymphocytes.
- Author
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West AL, von Gerichten J, Irvine NA, Miles EA, Lillycrop KA, Calder PC, Fielding BA, and Burdge GC
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- Adult, Humans, alpha-Linolenic Acid metabolism, T-Lymphocytes metabolism, Fatty Acids, Monounsaturated metabolism, Fatty Acids, Omega-6, Fatty Acids metabolism, Fatty Acids, Omega-3 metabolism
- Abstract
Introduction: Immune function changes across the life course; the fetal immune system is characterised by tolerance while that of seniors is less able to respond effectively to antigens and is more pro-inflammatory than in younger adults. Lipids are involved centrally in immune function but there is limited information about how T cell lipid metabolism changes during the life course., Methods and Results: We investigated whether life stage alters fatty acid composition, lipid droplet content and α-linolenic acid (18:3ω-3) metabolism in human fetal CD3
+ T lymphocytes and in CD3+ T lymphocytes from adults (median 41 years) and seniors (median 70 years). Quiescent fetal T cells had higher saturated (SFA), monounsaturated fatty acid (MUFA), and ω-6 polyunsaturated fatty acid (PUFA) contents than adults or seniors. Activation-induced changes in fatty acid composition differed between life stages. The principal metabolic fates of [13 C]18:3ω-3 were constitutive hydroxyoctadecatrienoic acid synthesis and β-oxidation and carbon recycling into SFA and MUFA. These processes declined progressively across the life course. Longer chain ω-3 PUFA synthesis was a relatively minor metabolic fate of 18:3ω-3 at all life stages. Fetal and adult T lymphocytes had similar lipid droplet contents, which were lower than in T cells from seniors. Variation in the lipid droplet content of adult T cells accounted for 62% of the variation in mitogen-induced CD69 expression, but there was no significant relationship in fetal cells or lymphocytes from seniors., Discussion: Together these findings show that fatty acid metabolism in human T lymphocytes changes across the life course in a manner that may facilitate the adaptation of immune function to different life stages., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 West, von Gerichten, Irvine, Miles, Lillycrop, Calder, Fielding and Burdge.)- Published
- 2022
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13. Multi-Omics Reveals Mechanisms of Partial Modulation of COVID-19 Dysregulation by Glucocorticoid Treatment.
- Author
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Spick M, Campbell A, Baricevic-Jones I, von Gerichten J, Lewis HM, Frampas CF, Longman K, Stewart A, Dunn-Walters D, Skene DJ, Geifman N, Whetton AD, and Bailey MJ
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- Humans, Proteomics methods, Hydrocortisone, Metabolomics methods, Amino Acids metabolism, Tyrosine, Arginine, Bile Acids and Salts, Glucocorticoids pharmacology, Glucocorticoids therapeutic use, COVID-19 Drug Treatment
- Abstract
Treatments for COVID-19 infections have improved dramatically since the beginning of the pandemic, and glucocorticoids have been a key tool in improving mortality rates. The UK's National Institute for Health and Care Excellence guidance is for treatment to be targeted only at those requiring oxygen supplementation, however, and the interactions between glucocorticoids and COVID-19 are not completely understood. In this work, a multi-omic analysis of 98 inpatient-recruited participants was performed by quantitative metabolomics (using targeted liquid chromatography-mass spectrometry) and data-independent acquisition proteomics. Both 'omics datasets were analysed for statistically significant features and pathways differentiating participants whose treatment regimens did or did not include glucocorticoids. Metabolomic differences in glucocorticoid-treated patients included the modulation of cortisol and bile acid concentrations in serum, but no alleviation of serum dyslipidemia or increased amino acid concentrations (including tyrosine and arginine) in the glucocorticoid-treated cohort relative to the untreated cohort. Proteomic pathway analysis indicated neutrophil and platelet degranulation as influenced by glucocorticoid treatment. These results are in keeping with the key role of platelet-associated pathways and neutrophils in COVID-19 pathogenesis and provide opportunity for further understanding of glucocorticoid action. The findings also, however, highlight that glucocorticoids are not fully effective across the wide range of 'omics dysregulation caused by COVID-19 infections.
- Published
- 2022
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14. The [ 13 C]octanoic acid breath test for gastric emptying quantification: A focus on nutrition and modeling.
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von Gerichten J, Elnesr MH, Prollins JE, De Mel IA, Flanagan A, Johnston JD, Fielding BA, and Short M
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- Caprylates, Carbon Isotopes, Breath Tests methods, Gastric Emptying physiology
- Abstract
Gastric emptying (GE) is the process of food being processed by the stomach and delivered to the small intestine where nutrients such as lipids are absorbed into the blood circulation. The combination of an easy and inexpensive method to measure GE such as the CO
2 breath test using the stable isotope [13 C]octanoic acid with semi-mechanistic modeling could foster a wider application in nutritional studies to further understand the metabolic response to food. Here, we discuss the use of the [13 C]octanoic acid breath test to label the solid phase of a meal, and the factors that influence GE to support mechanistic studies. Furthermore, we give an overview of existing mathematical models for the interpretation of the breath test data and how much nutritional studies could benefit from a physiological based pharmacokinetic model approach., (© 2022 The Authors. Lipids published by Wiley Periodicals LLC on behalf of AOCS.)- Published
- 2022
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15. The Partitioning of Newly Assimilated Linoleic and α-Linolenic Acids Between Synthesis of Longer-Chain Polyunsaturated Fatty Acids and Hydroxyoctadecaenoic Acids Is a Putative Branch Point in T-Cell Essential Fatty Acid Metabolism.
- Author
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von Gerichten J, West AL, Irvine NA, Miles EA, Calder PC, Lillycrop KA, Fielding BA, and Burdge GC
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- Adolescent, Adult, Cells, Cultured, Fatty Acid Desaturases metabolism, Fatty Acid Elongases metabolism, Female, Gas Chromatography-Mass Spectrometry, Humans, Lipid Metabolism, Lymphocyte Activation, Male, Young Adult, Fatty Acids, Essential metabolism, Fatty Acids, Unsaturated metabolism, Linoleic Acid metabolism, T-Lymphocytes metabolism, alpha-Linolenic Acid metabolism
- Abstract
Longer-chain polyunsaturated fatty acids (LCPUFAs) ≥20 carbons long are required for leukocyte function. These can be obtained from the diet, but there is some evidence that leukocytes can convert essential fatty acids (EFAs) into LCPUFAs. We used stable isotope tracers to investigate LCPUFA biosynthesis and the effect of different EFA substrate ratios in human T lymphocytes. CD3
+ T cells were incubated for up to 48 h with or without concanavalin A in media containing a 18:2n-6:18:3n-3 (EFA) ratio of either 5:1 or 8:1 and [13 C]18:3n-3 plus [d5 ]18:2n-6. Mitogen stimulation increased the amounts of 16:1n-7, 18:1n-9, 18:2n-6, 20:3n-6, 20:4n-6, 18:3n-3, and 20:5n-3 in T cells. Expression of the activation marker CD69 preceded increased FADS2 and FADS1 mRNA expression and increased amounts of [d5 ]20:2n-6 and [13 C]20:3n-3 at 48 h. In addition, 22-carbon n-6 or n-3 LCPUFA synthesis was not detected, consistent with the absence of ELOVL2 expression. An EFA ratio of 8:1 reduced 18:3n-3 conversion and enhanced 20:2n-6 synthesis compared to a 5:1 ratio. Here, [d5 ]9- and [d5 ]-13-hydroxyoctadecadienoic (HODE) and [13 C]9- and [13 C]13-hydroxyoctadecatrienoic acids (HOTrE) were the major labelled oxylipins in culture supernatants; labelled oxylipins ≥20 carbons were not detected. An EFA ratio of 8:1 suppressed 9- and 13-HOTrE synthesis, but there was no significant effect on 9- and 13-HODE synthesis. These findings suggest that partitioning of newly assimilated EFA between LCPUFA synthesis and hydroxyoctadecaenoic acid may be a metabolic branch point in T-cell EFA metabolism that has implications for understanding the effects of dietary fats on T lymphocyte function., Competing Interests: GB has received research funding from Nestle, Abbott Nutrition, and Danone and has served as a member of the Scientific Advisory Board of BASF. PC acts as a consultant to BASF, Smartfish, DSM, Cargill, Danone/Nutricia, and Fresenius-Kabi. KL has received research funding from Nestle, Abbott Nutrition, and Danone. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 von Gerichten, West, Irvine, Miles, Calder, Lillycrop, Fielding and Burdge.)- Published
- 2021
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16. Bacterial immunogenic α-galactosylceramide identified in the murine large intestine: dependency on diet and inflammation.
- Author
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von Gerichten J, Lamprecht D, Opálka L, Soulard D, Marsching C, Pilz R, Sencio V, Herzer S, Galy B, Nordström V, Hopf C, Gröne HJ, Trottein F, and Sandhoff R
- Subjects
- Animals, Galactosylceramides genetics, Inflammation microbiology, Intestine, Large microbiology, Mice, Mice, Inbred Strains, Bacteroides fragilis chemistry, Bacteroides fragilis immunology, Diet, Galactosylceramides immunology, Inflammation immunology, Intestine, Large immunology, Intestine, Large metabolism
- Abstract
The glycosphingolipid, α-galactosylceramide (αGalCer), when presented by CD1d on antigen-presenting cells, efficiently activates invariant natural killer T ( i NKT) cells. Thereby, it modulates immune responses against tumors, microbial and viral infections, and autoimmune diseases. Recently, the production of αGalCer by Bacteroidetes from the human gut microbiome was elucidated. Using hydrophilic interaction chromatography coupled to MS
2 , we screened murine intestinal tracts to identify and quantify αGalCers, and we investigated the αGalCer response to different dietary and physiologic conditions. In both the cecum and the colon of mice, we found 1-15 pmol of αGalCer per milligram of protein; in contrast, mice lacking microbiota (germ-free mice) and fed identical diet did not harbor αGalCer. The identified αGalCer contained a β( R )-hydroxylated hexadecanoyl chain N -linked to C18-sphinganine, which differed from what has been reported with Bacteroides fragilis Unlike β-anomeric structures, but similar to αGalCers from B. fragilis , the synthetic form of the murine αGalCer induced i NKT cell activation in vitro. Last, we observed a decrease in αGalCer production in mice exposed to conditions that alter the composition of the gut microbiota, including Western type diet, colitis, and influenza A virus infection. Collectively, this study suggests that αGalCer is produced by commensals in the mouse intestine and reveals that stressful conditions causing dysbiosis alter its synthesis. The consequences of this altered production on i NKT cell-mediated local and systemic immune responses are worthy of future studies., (Copyright © 2019 von Gerichten et al.)- Published
- 2019
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17. Renal globotriaosylceramide facilitates tubular albumin absorption and its inhibition protects against acute kidney injury.
- Author
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Morace I, Pilz R, Federico G, Jennemann R, Krunic D, Nordström V, von Gerichten J, Marsching C, Schießl IM, Müthing J, Wunder C, Johannes L, Sandhoff R, and Gröne HJ
- Subjects
- Acute Kidney Injury chemically induced, Acute Kidney Injury pathology, Animals, Dioxanes therapeutic use, Disease Models, Animal, Galactosyltransferases genetics, Galactosyltransferases metabolism, Gentamicins metabolism, Gentamicins toxicity, Humans, Intravital Microscopy, Kidney Tubules, Proximal drug effects, Kidney Tubules, Proximal pathology, Kidney Tubules, Proximal ultrastructure, Low Density Lipoprotein Receptor-Related Protein-2 metabolism, Male, Mice, Mice, Knockout, Microscopy, Electron, Microscopy, Fluorescence, Multiphoton, Microvilli drug effects, Microvilli metabolism, Myoglobin metabolism, Myoglobin toxicity, Pyrrolidines therapeutic use, Receptors, Cell Surface metabolism, Renal Elimination drug effects, Acute Kidney Injury drug therapy, Albumins metabolism, Dioxanes pharmacology, Galactosyltransferases antagonists & inhibitors, Pyrrolidines pharmacology, Renal Reabsorption drug effects, Trihexosylceramides metabolism
- Abstract
To elucidate the physiologic function of renal globotriaosylceramide (Gb3/CD77), which up-to-date has been associated exclusively with Shiga toxin binding, we have analyzed renal function in Gb3-deficient mice. Gb3 synthase KO (Gb3S
-/- ) mice displayed an increased renal albumin and low molecular weight protein excretion compared to WT. Gb3 localized at the brush border and within vesicular structures in WT proximal tubules and has now been shown to be closely associated with the receptor complex megalin/cubilin and with albumin uptake. In two clinically relevant mouse models of acute kidney injury caused by myoglobin as seen in rhabdomyolysis and the aminoglycoside gentamicin, Gb3S-/- mice showed a preserved renal function and morphology, compared to WT. Pharmacologic inhibition of glucosylceramide-based glycosphingolipids, including Gb3, in WT mice corroborated the results of genetically Gb3-deficient mice. In conclusion, our data significantly advance the current knowledge on the physiologic and pathophysiologic role of Gb3 in proximal tubules, showing an involvement in the reabsorption of filtered albumin, myoglobin and the aminoglycoside gentamicin., (Copyright © 2019 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
18. Deletion of Specific Sphingolipids in Distinct Neurons Improves Spatial Memory in a Mouse Model of Alzheimer's Disease.
- Author
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Herzer S, Hagan C, von Gerichten J, Dieterle V, Munteanu B, Sandhoff R, Hopf C, and Nordström V
- Abstract
Alzheimer's disease (AD) is characterized by progressive neurodegeneration and a concomitant loss of synapses and cognitive abilities. Recently, we have proposed that an alteration of neuronal membrane lipid microdomains increases neuronal resistance toward amyloid-β stress in cultured neurons and protects from neurodegeneration in a mouse model of AD. Lipid microdomains are highly enriched in a specific subclass of glycosphingolipids, termed gangliosides. The enzyme glucosylceramide synthase (GCS) catalyzes the rate-limiting step in the biosynthesis of these gangliosides. The present work now demonstrates that genetic GCS deletion in subsets of adult forebrain neurons significantly improves the spatial memory and counteracts the loss of dendritic spines in the hippocampal dentate gyrus of 5x familial AD mice (5xFAD// Ugcg f/f//Thy1-CreERT2//EYFP mice), when compared to 5xFAD// Ugcg f/f littermates (5xFAD mice). Aberrantly activated glial cells and their expression of pro-inflammatory cytokines have emerged as the major culprits for synaptic loss in AD. Typically, astrocytic activation is accompanied by a thickening of astrocytic processes, which impairs astrocytic support for neuronal synapses. In contrast to 5xFAD mice, 5xFAD// Ugcg f/f//Thy1-CreERT2//EYFP display a less pronounced thickening of astrocytic processes and a lower expression of tumor necrosis factor-α and interleukin 1-α in the hippocampus. Thus, this work further emphasizes that GCS inhibition may constitute a potential therapeutic target against AD.
- Published
- 2018
- Full Text
- View/download PDF
19. Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease.
- Author
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Seyrantepe V, Demir SA, Timur ZK, Von Gerichten J, Marsching C, Erdemli E, Oztas E, Takahashi K, Yamaguchi K, Ates N, Dönmez Demir B, Dalkara T, Erich K, Hopf C, Sandhoff R, and Miyagi T
- Subjects
- Animals, Brain Chemistry genetics, Cytoplasmic Vesicles pathology, Gangliosidoses, GM2 metabolism, Gliosis genetics, Gliosis pathology, Glycosphingolipids metabolism, Lameness, Animal genetics, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Neuraminidase deficiency, Neurons pathology, Purkinje Cells pathology, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Tay-Sachs Disease pathology, Gangliosidoses, GM2 genetics, Hexosaminidase B genetics, Neuraminidase genetics, Tay-Sachs Disease genetics
- Abstract
Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa
-/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa-/- Neu3-/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa-/- Neu3-/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa-/- Neu3-/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa-/- Neu3-/- mice. Thus, the Hexa-/- Neu3-/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
20. Diastereomer-specific quantification of bioactive hexosylceramides from bacteria and mammals.
- Author
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von Gerichten J, Schlosser K, Lamprecht D, Morace I, Eckhardt M, Wachten D, Jennemann R, Gröne HJ, Mack M, and Sandhoff R
- Subjects
- Animals, Gastrointestinal Microbiome, Humans, Mice, Stereoisomerism, Bacteria metabolism, Ceramides chemistry, Ceramides metabolism
- Abstract
Mammals synthesize, cell-type specifically, the diastereomeric hexosylceramides, β-galactosylceramide (GalCer) and β-glucosylceramide (GlcCer), which are involved in several diseases, such as sphingolipidosis, diabetes, chronic kidney diseases, or cancer. In contrast, Bacteroides fragilis , a member of the human gut microbiome, and the marine sponge, Agelas mauritianus , produce α-GalCer, one of the most potent stimulators for invariant natural killer T cells. To dissect the contribution of these individual stereoisomers to pathologies, we established a novel hydrophilic interaction chromatography-based LC-MS
2 method and separated ( R > 1.5) corresponding diastereomers from each other, independent of their lipid anchors. Testing various bacterial and mammalian samples, we could separate, identify (including the lipid anchor composition), and quantify endogenous β-GlcCer, β-GalCer, and α-GalCer isomers without additional derivatization steps. Thereby, we show a selective decrease of β-GlcCers versus β-GalCers in cell-specific models of GlcCer synthase-deficiency and an increase of specific β-GlcCers due to loss of β-glucoceramidase 2 activity. Vice versa, β-GalCer increased specifically when cerebroside sulfotransferase ( Gal3st1 ) was deleted. We further confirm β-GalCer as substrate of globotriaosylceramide synthase for galabiaosylceramide synthesis and identify additional members of the human gut microbiome to contain immunogenic α-GalCers. Finally, this method is shown to separate corresponding hexosylsphingosine standards, promoting its applicability in further investigations., (Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.)- Published
- 2017
- Full Text
- View/download PDF
21. Molecular imaging of brain localization of liposomes in mice using MALDI mass spectrometry.
- Author
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Fülöp A, Sammour DA, Erich K, von Gerichten J, van Hoogevest P, Sandhoff R, and Hopf C
- Subjects
- Animals, Liposomes, Male, Mice, Phosphatidylethanolamines chemistry, Phosphatidylethanolamines pharmacokinetics, Phosphatidylethanolamines pharmacology, Phosphatidylglycerols chemistry, Phosphatidylglycerols pharmacokinetics, Phosphatidylglycerols pharmacology, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacokinetics, Polyethylene Glycols pharmacology, Brain diagnostic imaging, Brain metabolism, Indocyanine Green chemistry, Indocyanine Green pharmacokinetics, Indocyanine Green pharmacology, Molecular Imaging methods, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
Phospholipids have excellent biocompatibility and are therefore often used as main components of liposomal drug carriers. In traditional bioanalytics, the in-vivo distribution of liposomal drug carriers is assessed using radiolabeled liposomal constituents. This study presents matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) as an alternative, label-free method for ex-vivo molecular imaging of liposomal drug carriers in mouse tissue. To this end, indocyanine green as cargo and two liposomal markers, 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine conjugated with monodisperse polyethylene glycol (PEG36-DSPE) were incorporated into liposomal carriers and administered to mice. We used MALDI MSI of the two lipid markers in both positive and negative ion mode for visualization of liposome integrity and distribution in mouse organs. Additional MSI of hemoglobin in the same tissue slice and pixel-by-pixel computational analysis of co-occurrence of lipid markers and hemoglobin served as indicator of liposome localization either in parenchyma or in blood vessels. Our proof-of-concept study suggests that liposomal components and indocyanine green distributed into all investigated organs.
- Published
- 2016
- Full Text
- View/download PDF
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