1
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Amodeo V, Davies T, Martinez-Segura A, Clements MP, Ragdale HS, Bailey A, Dos Santos MS, MacRae JI, Mokochinski J, Kramer H, Garcia-Diaz C, Gould AP, Marguerat S, Parrinello S. Diet suppresses glioblastoma initiation in mice by maintaining quiescence of mutation-bearing neural stem cells. Dev Cell 2023; 58:836-846.e6. [PMID: 37084728 PMCID: PMC10618406 DOI: 10.1016/j.devcel.2023.03.021] [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: 01/17/2021] [Revised: 12/09/2021] [Accepted: 03/28/2023] [Indexed: 04/23/2023]
Abstract
Glioblastoma is thought to originate from neural stem cells (NSCs) of the subventricular zone that acquire genetic alterations. In the adult brain, NSCs are largely quiescent, suggesting that deregulation of quiescence maintenance may be a prerequisite for tumor initiation. Although inactivation of the tumor suppressor p53 is a frequent event in gliomagenesis, whether or how it affects quiescent NSCs (qNSCs) remains unclear. Here, we show that p53 maintains quiescence by inducing fatty-acid oxidation (FAO) and that acute p53 deletion in qNSCs results in their premature activation to a proliferative state. Mechanistically, this occurs through direct transcriptional induction of PPARGC1a, which in turn activates PPARα to upregulate FAO genes. Dietary supplementation with fish oil containing omega-3 fatty acids, natural PPARα ligands, fully restores quiescence of p53-deficient NSCs and delays tumor initiation in a glioblastoma mouse model. Thus, diet can silence glioblastoma driver mutations, with important implications for cancer prevention.
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Affiliation(s)
- Valeria Amodeo
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, London WC1E 6DD, UK
| | - Timothy Davies
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, London WC1E 6DD, UK
| | - Amalia Martinez-Segura
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Melanie P Clements
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, London WC1E 6DD, UK
| | | | - Andrew Bailey
- The Francis Crick Institute, 1 Midland Road, London NW1 1AA, UK
| | | | - James I MacRae
- The Francis Crick Institute, 1 Midland Road, London NW1 1AA, UK
| | - Joao Mokochinski
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Holger Kramer
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Claudia Garcia-Diaz
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, London WC1E 6DD, UK
| | - Alex P Gould
- The Francis Crick Institute, 1 Midland Road, London NW1 1AA, UK
| | - Samuel Marguerat
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Simona Parrinello
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute, London WC1E 6DD, UK.
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2
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Zani F, Blagih J, Gruber T, Buck MD, Jones N, Hennequart M, Newell CL, Pilley SE, Soro-Barrio P, Kelly G, Legrave NM, Cheung EC, Gilmore IS, Gould AP, Garcia-Caceres C, Vousden KH. The dietary sweetener sucralose is a negative modulator of T cell-mediated responses. Nature 2023; 615:705-711. [PMID: 36922598 PMCID: PMC10033444 DOI: 10.1038/s41586-023-05801-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [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: 09/15/2021] [Accepted: 02/06/2023] [Indexed: 03/17/2023]
Abstract
Artificial sweeteners are used as calorie-free sugar substitutes in many food products and their consumption has increased substantially over the past years1. Although generally regarded as safe, some concerns have been raised about the long-term safety of the consumption of certain sweeteners2-5. In this study, we show that the intake of high doses of sucralose in mice results in immunomodulatory effects by limiting T cell proliferation and T cell differentiation. Mechanistically, sucralose affects the membrane order of T cells, accompanied by a reduced efficiency of T cell receptor signalling and intracellular calcium mobilization. Mice given sucralose show decreased CD8+ T cell antigen-specific responses in subcutaneous cancer models and bacterial infection models, and reduced T cell function in models of T cell-mediated autoimmunity. Overall, these findings suggest that a high intake of sucralose can dampen T cell-mediated responses, an effect that could be used in therapy to mitigate T cell-dependent autoimmune disorders.
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Affiliation(s)
- Fabio Zani
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
| | - Julianna Blagih
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
- University of Montreal, Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada.
| | - Tim Gruber
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München and German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Michael D Buck
- Immunobiology Laboratory, The Francis Crick Institute, London, UK
| | - Nicholas Jones
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - Marc Hennequart
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | - Clare L Newell
- National Physical Laboratory, Teddington, UK
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, UK
| | - Steven E Pilley
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | - Pablo Soro-Barrio
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Gavin Kelly
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Nathalie M Legrave
- Metabolomics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Eric C Cheung
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | | | - Alex P Gould
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, UK
| | - Cristina Garcia-Caceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Karen H Vousden
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
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3
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Serpente P, Zhang Y, Islimye E, Hart-Johnson S, Gould AP. Quantification of fetal organ sparing in maternal low-protein dietary models. Wellcome Open Res 2022; 6:218. [PMID: 35634534 PMCID: PMC9120932 DOI: 10.12688/wellcomeopenres.17124.2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Maternal malnutrition can lead to fetal growth restriction. This is often associated with organ sparing and long-lasting physiological dysfunctions during adulthood, although the underlying mechanisms are not yet well understood. Methods: Low protein (LP) dietary models in C57BL/6J mice were used to investigate the proximal effects of maternal malnutrition on fetal organ weights and organ sparing at embryonic day 18.5 (E18.5). Results: Maternal 8% LP diet induced strikingly different degrees of fetal growth restriction in different animal facilities, but adjustment of dietary protein content allowed similar fetal body masses to be obtained. A maternal LP diet that restricted fetal body mass by 40% did not decrease fetal brain mass to the same extent, reflecting positive growth sparing of this organ. Under these conditions, fetal pancreas and liver mass decreased by 60-70%, indicative of negative organ sparing. A series of dietary swaps between LP and standard diets showed that the liver is capable of efficient catch-up growth from as late as E14.5 whereas, after E10.5, the pancreas is not. Conclusions: This study highlights that the reproducibility of LP fetal growth restriction studies between laboratories can be improved by careful calibration of maternal dietary protein content. LP diets that induce 30-40% restriction of prenatal growth provide a good model for fetal organ sparing. For the liver, recovery of growth following protein restriction is efficient throughout fetal development but, for the pancreas, transient LP exposures spanning the progenitor expansion phase lead to an irreversible fetal growth deficit.
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Affiliation(s)
- Patricia Serpente
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
| | - Ying Zhang
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
| | - Eva Islimye
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
| | - Sarah Hart-Johnson
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
- Biological Research Facility, The Francis Crick Institute, London, NW1 1AT, UK
| | - Alex P. Gould
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
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4
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Abstract
Lipid droplets are highly dynamic intracellular organelles that store neutral lipids such as cholesteryl esters and triacylglycerols. They have recently emerged as key stress response components in many different cell types. Lipid droplets in the nervous system are mostly observed in vivo in glia, ependymal cells and microglia. They tend to become more numerous in these cell types and can also form in neurons as a consequence of ageing or stresses involving redox imbalance and lipotoxicity. Abundant lipid droplets are also a characteristic feature of several neurodegenerative diseases. In this minireview, we take a cell-type perspective on recent advances in our understanding of lipid droplet metabolism in glia, neurons and neural stem cells during health and disease. We highlight that a given lipid droplet subfunction, such as triacylglycerol lipolysis, can be physiologically beneficial or harmful to the functions of the nervous system depending upon cellular context. The mechanistic understanding of context-dependent lipid droplet functions in the nervous system is progressing apace, aided by new technologies for probing the lipid droplet proteome and lipidome with single-cell type precision.
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5
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Serpente P, Zhang Y, Islimye E, Hart-Johnson S, Gould AP. Quantification of fetal organ sparing in maternal low-protein dietary models. Wellcome Open Res 2021; 6:218. [PMID: 35634534 PMCID: PMC9120932 DOI: 10.12688/wellcomeopenres.17124.1] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2021] [Indexed: 11/08/2023] Open
Abstract
Background: Maternal malnutrition can lead to fetal growth restriction. This is often associated with organ sparing and long-lasting physiological dysfunctions during adulthood, although the underlying mechanisms are not yet well understood. Methods: Low protein (LP) dietary models in C57BL/6J mice were used to investigate the proximal effects of maternal malnutrition on fetal organ weights and organ sparing at embryonic day 18.5 (E18.5). Results: Maternal 8% LP diet induced strikingly different degrees of fetal growth restriction in different animal facilities, but adjustment of dietary protein content allowed similar fetal body masses to be obtained. A maternal LP diet that restricted fetal body mass by 40% did not decrease fetal brain mass to the same extent, reflecting positive growth sparing of this organ. Under these conditions, fetal pancreas and liver mass decreased by 60-70%, indicative of negative organ sparing. A series of dietary swaps between LP and standard diets showed that the liver is capable of efficient catch-up growth from as late as E14.5 whereas, after E10.5, the pancreas is not. Conclusions: This study highlights that the reproducibility of LP fetal growth restriction studies between laboratories can be improved by careful calibration of maternal dietary protein content. LP diets that induce 30-40% restriction of prenatal growth provide a good model for fetal organ sparing. For the liver, recovery of growth following protein restriction is efficient throughout fetal development but, for the pancreas, transient LP exposures spanning the progenitor expansion phase lead to an irreversible fetal growth deficit.
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Affiliation(s)
- Patricia Serpente
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
| | - Ying Zhang
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
| | - Eva Islimye
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
| | - Sarah Hart-Johnson
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
- Biological Research Facility, The Francis Crick Institute, London, NW1 1AT, UK
| | - Alex P. Gould
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, NW1 1AT, UK
- MRC National Institute for Medical Research, UK, Mill Hill, London, NW7 1AA, UK
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6
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Cable J, Pourquié O, Wellen KE, Finley LWS, Aulehla A, Gould AP, Teleman A, Tu WB, Garrett WS, Miguel-Aliaga I, Perrimon N, Hooper LV, Walhout AJM, Wei W, Alexandrov T, Erez A, Ralser M, Rabinowitz JD, Hemalatha A, Gutiérrez-Pérez P, Chandel NS, Rutter J, Locasale JW, Landoni JC, Christofk H. Metabolic decisions in development and disease-a Keystone Symposia report. Ann N Y Acad Sci 2021; 1506:55-73. [PMID: 34414571 DOI: 10.1111/nyas.14678] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 07/31/2021] [Indexed: 12/11/2022]
Abstract
There is an increasing appreciation for the role of metabolism in cell signaling and cell decision making. Precise metabolic control is essential in development, as evident by the disorders caused by mutations in metabolic enzymes. The metabolic profile of cells is often cell-type specific, changing as cells differentiate or during tumorigenesis. Recent evidence has shown that changes in metabolism are not merely a consequence of changes in cell state but that metabolites can serve to promote and/or inhibit these changes. Metabolites can link metabolic pathways with cell signaling pathways via several mechanisms, for example, by serving as substrates for protein post-translational modifications, by affecting enzyme activity via allosteric mechanisms, or by altering epigenetic markers. Unraveling the complex interactions governing metabolism, gene expression, and protein activity that ultimately govern a cell's fate will require new tools and interactions across disciplines. On March 24 and 25, 2021, experts in cell metabolism, developmental biology, and human disease met virtually for the Keystone eSymposium, "Metabolic Decisions in Development and Disease." The discussions explored how metabolites impact cellular and developmental decisions in a diverse range of model systems used to investigate normal development, developmental disorders, dietary effects, and cancer-mediated changes in metabolism.
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Affiliation(s)
| | - Olivier Pourquié
- Department of Genetics, Harvard Medical School, Boston, Massachusetts.,Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.,Harvard Stem Cell Institute, Boston, Massachusetts
| | - Kathryn E Wellen
- Department of Cancer Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Lydia W S Finley
- Cell Biology Program and Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Alexander Aulehla
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | - Aurelio Teleman
- German Cancer Research Center (DKFZ) and Heidelberg University, Heidelberg, Germany
| | - William B Tu
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Wendy Sarah Garrett
- Harvard T. H. Chan School of Public Health and Dana-Farber Cancer, Boston, Massachusetts
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences and Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Howard Hughes Institute, Boston, Massachusetts
| | - Lora V Hooper
- Department of Immunology and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas
| | - A J Marian Walhout
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Wei Wei
- Department of Pathology, Stanford University School of Medicine, Stanford, California.,Department of Biology and Stanford ChEM-H, Stanford University, Stanford, California
| | - Theodore Alexandrov
- Structural and Computational Biology Unit and Molecular Medicine Partnership Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Markus Ralser
- Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, UK.,Department of Biochemistry, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Joshua D Rabinowitz
- Department of Chemistry and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey
| | - Anupama Hemalatha
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut
| | - Paula Gutiérrez-Pérez
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Navdeep S Chandel
- Department of Medicine, Robert H. Lurie Cancer Center, Chicago, Illinois.,Department of Biochemistry and Molecular Genetics, Robert H. Lurie Cancer Center Metabolomics Core, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Jared Rutter
- Department of Biochemistry and Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| | - Juan C Landoni
- Research Program in Stem Cells and Metabolism, University of Helsinki, Helsinki, Finland
| | - Heather Christofk
- Departments of Biological Chemistry and Molecular & Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California
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7
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Lubojemska A, Stefana MI, Sorge S, Bailey AP, Lampe L, Yoshimura A, Burrell A, Collinson L, Gould AP. Adipose triglyceride lipase protects renal cell endocytosis in a Drosophila dietary model of chronic kidney disease. PLoS Biol 2021; 19:e3001230. [PMID: 33945525 PMCID: PMC8121332 DOI: 10.1371/journal.pbio.3001230] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 05/14/2021] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity-related renal lipotoxicity and chronic kidney disease (CKD) are prevalent pathologies with complex aetiologies. One hallmark of renal lipotoxicity is the ectopic accumulation of lipid droplets in kidney podocytes and in proximal tubule cells. Renal lipid droplets are observed in human CKD patients and in high-fat diet (HFD) rodent models, but their precise role remains unclear. Here, we establish a HFD model in Drosophila that recapitulates renal lipid droplets and several other aspects of mammalian CKD. Cell type-specific genetic manipulations show that lipid can overflow from adipose tissue and is taken up by renal cells called nephrocytes. A HFD drives nephrocyte lipid uptake via the multiligand receptor Cubilin (Cubn), leading to the ectopic accumulation of lipid droplets. These nephrocyte lipid droplets correlate with endoplasmic reticulum (ER) and mitochondrial deficits, as well as with impaired macromolecular endocytosis, a key conserved function of renal cells. Nephrocyte knockdown of diglyceride acyltransferase 1 (DGAT1), overexpression of adipose triglyceride lipase (ATGL), and epistasis tests together reveal that fatty acid flux through the lipid droplet triglyceride compartment protects the ER, mitochondria, and endocytosis of renal cells. Strikingly, boosting nephrocyte expression of the lipid droplet resident enzyme ATGL is sufficient to rescue HFD-induced defects in renal endocytosis. Moreover, endocytic rescue requires a conserved mitochondrial regulator, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC1α). This study demonstrates that lipid droplet lipolysis counteracts the harmful effects of a HFD via a mitochondrial pathway that protects renal endocytosis. It also provides a genetic strategy for determining whether lipid droplets in different biological contexts function primarily to release beneficial or to sequester toxic lipids.
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Affiliation(s)
- Aleksandra Lubojemska
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - M. Irina Stefana
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sebastian Sorge
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Andrew P. Bailey
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lena Lampe
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Azumi Yoshimura
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alana Burrell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alex P. Gould
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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8
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Newell CL, Vorng J, MacRae JI, Gilmore IS, Gould AP. Cryogenic OrbiSIMS Localizes Semi‐Volatile Molecules in Biological Tissues. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Clare L. Newell
- Physiology and Metabolism Laboratory The Francis Crick Institute 1 Midland Road London NW1 1AT UK
- NiCE-MSI National Physical Laboratory Hampton Road Teddington TW11 0LW UK
| | - Jean‐Luc Vorng
- NiCE-MSI National Physical Laboratory Hampton Road Teddington TW11 0LW UK
| | - James I. MacRae
- Metabolomics Science Technology Platform The Francis Crick Institute 1 Midland Road London NW1 1AT UK
| | - Ian S. Gilmore
- NiCE-MSI National Physical Laboratory Hampton Road Teddington TW11 0LW UK
| | - Alex P. Gould
- Physiology and Metabolism Laboratory The Francis Crick Institute 1 Midland Road London NW1 1AT UK
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9
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Newell CL, Vorng J, MacRae JI, Gilmore IS, Gould AP. Cryogenic OrbiSIMS Localizes Semi-Volatile Molecules in Biological Tissues. Angew Chem Int Ed Engl 2020; 59:18194-18200. [PMID: 32603009 PMCID: PMC7589292 DOI: 10.1002/anie.202006881] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/20/2020] [Indexed: 12/25/2022]
Abstract
OrbiSIMS is a recently developed instrument for label-free imaging of chemicals with micron spatial resolution and high mass resolution. We report a cryogenic workflow for OrbiSIMS (Cryo-OrbiSIMS) that improves chemical detection of lipids and other biomolecules in tissues. Cryo-OrbiSIMS boosts ionization yield and decreases ion-beam induced fragmentation, greatly improving the detection of biomolecules such as triacylglycerides. It also increases chemical coverage to include molecules with intermediate or high vapor pressures, such as free fatty acids and semi-volatile organic compounds (SVOCs). We find that Cryo-OrbiSIMS reveals the hitherto unknown localization patterns of SVOCs with high spatial and chemical resolution in diverse plant, animal, and human tissues. We also show that Cryo-OrbiSIMS can be combined with genetic analysis to identify enzymes regulating SVOC metabolism. Cryo-OrbiSIMS is applicable to high resolution imaging of a wide variety of non-volatile and semi-volatile molecules across many areas of biomedicine.
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Affiliation(s)
- Clare L. Newell
- Physiology and Metabolism LaboratoryThe Francis Crick Institute1 Midland RoadLondonNW1 1ATUK
- NiCE-MSINational Physical LaboratoryHampton RoadTeddingtonTW11 0LWUK
| | - Jean‐Luc Vorng
- NiCE-MSINational Physical LaboratoryHampton RoadTeddingtonTW11 0LWUK
| | - James I. MacRae
- Metabolomics Science Technology PlatformThe Francis Crick Institute1 Midland RoadLondonNW1 1ATUK
| | - Ian S. Gilmore
- NiCE-MSINational Physical LaboratoryHampton RoadTeddingtonTW11 0LWUK
| | - Alex P. Gould
- Physiology and Metabolism LaboratoryThe Francis Crick Institute1 Midland RoadLondonNW1 1ATUK
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10
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Sawala A, Gould AP. Two Negatives Make a Positive for Insulin Secretion and Growth. Dev Cell 2019; 48:11-12. [PMID: 30620897 DOI: 10.1016/j.devcel.2018.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The confusingly named growth-blocking peptides are nutrient-dependent adipokines that stimulate insulin secretion and boost growth in developing flies. In this issue of Developmental Cell, Meschi et al. (2018) show that these adipose tissue-derived factors regulate insulin secretion by silencing a pair of inhibitory neurons that synapse with insulin-producing cells.
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Affiliation(s)
- Annick Sawala
- The Francis Crick Institute, 1 Midland Road, London NW1 1AA, UK
| | - Alex P Gould
- The Francis Crick Institute, 1 Midland Road, London NW1 1AA, UK.
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11
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Froldi F, Pachnis P, Szuperák M, Costas O, Fernando T, Gould AP, Cheng LY. Histidine is selectively required for the growth of Myc-dependent dedifferentiation tumours in the Drosophila CNS. EMBO J 2019; 38:embj.201899895. [PMID: 30804004 PMCID: PMC6443203 DOI: 10.15252/embj.201899895] [Citation(s) in RCA: 10] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 01/09/2019] [Accepted: 01/16/2019] [Indexed: 12/31/2022] Open
Abstract
Rewired metabolism of glutamine in cancer has been well documented, but less is known about other amino acids such as histidine. Here, we use Drosophila cancer models to show that decreasing the concentration of histidine in the diet strongly inhibits the growth of mutant clones induced by loss of Nerfin‐1 or gain of Notch activity. In contrast, changes in dietary histidine have much less effect on the growth of wildtype neural stem cells and Prospero neural tumours. The reliance of tumours on dietary histidine and also on histidine decarboxylase (Hdc) depends upon their growth requirement for Myc. We demonstrate that Myc overexpression in nerfin‐1 tumours is sufficient to switch their mode of growth from histidine/Hdc sensitive to resistant. This study suggests that perturbations in histidine metabolism selectively target neural tumours that grow via a dedifferentiation process involving large cell size increases driven by Myc.
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Affiliation(s)
- Francesca Froldi
- Peter MacCallum Cancer Centre, Parkville, Vic., Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Vic., Australia
| | | | - Milán Szuperák
- Peter MacCallum Cancer Centre, Parkville, Vic., Australia.,Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Olivia Costas
- Peter MacCallum Cancer Centre, Parkville, Vic., Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Vic., Australia
| | | | | | - Louise Y Cheng
- Peter MacCallum Cancer Centre, Parkville, Vic., Australia .,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Vic., Australia.,The Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Vic., Australia
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12
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Fernando T, Sawala A, Bailey AP, Gould AP, Driscoll PC. An Improved Method for Measuring Absolute Metabolite Concentrations in Small Biofluid or Tissue Samples. J Proteome Res 2019; 18:1503-1512. [PMID: 30757904 PMCID: PMC6456871 DOI: 10.1021/acs.jproteome.8b00773] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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] [Indexed: 12/16/2022]
Abstract
![]()
The
measurement of absolute metabolite concentrations in small
samples remains a significant analytical challenge. This is particularly
the case when the sample volume is only a few microliters or less
and cannot be determined accurately via direct measurement. We previously
developed volume determination with two standards (VDTS) as a method
to address this challenge for biofluids. As a proof-of-principle,
we applied VDTS to NMR spectra of polar metabolites in the hemolymph
(blood) of the tiny yet powerful genetic model Drosophila
melanogaster. This showed that VDTS calculation of absolute
metabolite concentrations in fed versus starved Drosophila larvae is more accurate than methods utilizing normalization to
total spectral signal. Here, we introduce paired VDTS (pVDTS), an
improved VDTS method for biofluids and solid tissues that implements
the statistical power of paired control and experimental replicates.
pVDTS utilizes new equations that also include a correction for dilution
errors introduced by the variable surface wetness of solid samples.
We then show that metabolite concentrations in Drosophila larvae are more precisely determined and logically consistent using
pVDTS than using the original VDTS method. The refined pVDTS workflow
described in this study is applicable to a wide range of different
tissues and biofluids.
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Affiliation(s)
- Tharindu Fernando
- Physiology and Metabolism Laboratory , The Francis Crick Institute , 1 Midland Road , London NW1 1AT , U.K
| | - Annick Sawala
- Physiology and Metabolism Laboratory , The Francis Crick Institute , 1 Midland Road , London NW1 1AT , U.K
| | - Andrew P Bailey
- Physiology and Metabolism Laboratory , The Francis Crick Institute , 1 Midland Road , London NW1 1AT , U.K
| | - Alex P Gould
- Physiology and Metabolism Laboratory , The Francis Crick Institute , 1 Midland Road , London NW1 1AT , U.K
| | - Paul C Driscoll
- Metabolomics Science Technology Platform , The Francis Crick Institute , 1 Midland Road , London NW1 1AT , U.K
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13
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Abstract
Sexual size dimorphism (SSD), a sex difference in body size, is widespread throughout the animal kingdom, raising the question of how sex influences existing growth regulatory pathways to bring about SSD. In insects, somatic sexual differentiation has long been considered to be controlled strictly cell-autonomously. Here, we discuss our surprising finding that in Drosophila larvae, the sex determination gene Sex-lethal (Sxl) functions in neurons to non-autonomously specify SSD. We found that Sxl is required in specific neuronal subsets to upregulate female body growth, including in the neurosecretory insulin producing cells, even though insulin-like peptides themselves appear not to be involved. SSD regulation by neuronal Sxl is also independent of its known splicing targets, transformer and msl-2, suggesting that it involves a new molecular mechanism. Interestingly, SSD control by neuronal Sxl is selective for larval, not imaginal tissue types, and operates in addition to cell-autonomous effects of Sxl and Tra, which are present in both larval and imaginal tissues. Overall, our findings add to a small but growing number of studies reporting non-autonomous, likely hormonal, control of sex differences in Drosophila, and suggest that the principles of sexual differentiation in insects and mammals may be more similar than previously thought.
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Affiliation(s)
- Annick Sawala
- a Physiology & Metabolism Laboratory , The Francis Crick Institute , London , UK
| | - Alex P Gould
- a Physiology & Metabolism Laboratory , The Francis Crick Institute , London , UK
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14
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Obata F, Fons CO, Gould AP. Early-life exposure to low-dose oxidants can increase longevity via microbiome remodelling in Drosophila. Nat Commun 2018; 9:975. [PMID: 29515102 PMCID: PMC5841413 DOI: 10.1038/s41467-018-03070-w] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [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: 07/06/2017] [Accepted: 01/16/2018] [Indexed: 02/07/2023] Open
Abstract
Environmental stresses experienced during development exert many long-term effects upon health and disease. For example, chemical oxidants or genetic perturbations that induce low levels of reactive oxygen species can extend lifespan in several species. In some cases, the beneficial effects of low-dose oxidants are attributed to adaptive protective mechanisms such as mitohormesis, which involve long-term increases in the expression of stress response genes. Here we show in Drosophila that transient exposure to low concentrations of oxidants during development leads to an extension of adult lifespan. Surprisingly, this depends upon oxidants acting in an antibiotic-like manner to selectively deplete the microbiome of Acetobacter proteobacteria. We demonstrate that the presence of Acetobacter species, such as A. aceti, in the indigenous microbiota increases age-related gut dysfunction and shortens lifespan. This study demonstrates that low-dose oxidant exposure during early life can extend lifespan via microbiome remodelling rather than mitohormesis.
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Affiliation(s)
- Fumiaki Obata
- Physiology and Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Clara O Fons
- Physiology and Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Alex P Gould
- Physiology and Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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15
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Stefana MI, Driscoll PC, Obata F, Pengelly AR, Newell CL, MacRae JI, Gould AP. Developmental diet regulates Drosophila lifespan via lipid autotoxins. Nat Commun 2017; 8:1384. [PMID: 29123106 PMCID: PMC5680271 DOI: 10.1038/s41467-017-01740-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [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: 05/27/2017] [Accepted: 10/13/2017] [Indexed: 12/19/2022] Open
Abstract
Early-life nourishment exerts long-term influences upon adult physiology and disease risk. These lasting effects of diet are well established but the underlying mechanisms are only partially understood. Here we show that restricting dietary yeast during Drosophila development can, depending upon the subsequent adult environment, more than double median lifespan. Developmental diet acts via a long-term influence upon the adult production of toxic molecules, which we term autotoxins, that are shed into the environment and shorten the lifespan of both sexes. Autotoxins are synthesised by oenocytes and some of them correspond to alkene hydrocarbons that also act as pheromones. This study identifies a mechanism by which the developmental dietary history of an animal regulates its own longevity and that of its conspecific neighbours. It also has important implications for the design of lifespan experiments as autotoxins can influence the regulation of longevity by other factors including diet, sex, insulin signalling and population density.
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Affiliation(s)
- M Irina Stefana
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- JDRF/Wellcome Diabetes and Inflammation Laboratory, Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Paul C Driscoll
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Fumiaki Obata
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | | | - Clare L Newell
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - James I MacRae
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Alex P Gould
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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16
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Abstract
Sexual dimorphisms in body size are widespread throughout the animal kingdom but their underlying mechanisms are not well characterized. Most models for how sex chromosome genes specify size dimorphism have emphasized the importance of gonadal hormones and cell-autonomous influences in mammals versus strictly cell-autonomous mechanisms in Drosophila melanogaster. Here, we use tissue-specific genetics to investigate how sexual size dimorphism (SSD) is established in Drosophila. We find that the larger body size characteristic of Drosophila females is established very early in larval development via an increase in the growth rate per unit of body mass. We demonstrate that the female sex determination gene, Sex-lethal (Sxl), functions in central nervous system (CNS) neurons as part of a relay that specifies the early sex-specific growth trajectories of larval but not imaginal tissues. Neuronal Sxl acts additively in 2 neuronal subpopulations, one of which corresponds to 7 median neurosecretory cells: the insulin-producing cells (IPCs). Surprisingly, however, male-female differences in the production of insulin-like peptides (Ilps) from the IPCs do not appear to be involved in establishing SSD in early larvae, although they may play a later role. These findings support a relay model in which Sxl in neurons and Sxl in local tissues act together to specify the female-specific growth of the larval body. They also reveal that, even though the sex determination pathways in Drosophila and mammals are different, they both modulate body growth via a combination of tissue-autonomous and nonautonomous inputs.
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Affiliation(s)
| | - Alex P. Gould
- The Francis Crick Institute, London, United Kingdom
- * E-mail:
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17
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Welte MA, Gould AP. Lipid droplet functions beyond energy storage. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1260-1272. [PMID: 28735096 PMCID: PMC5595650 DOI: 10.1016/j.bbalip.2017.07.006] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [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: 05/24/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 02/07/2023]
Abstract
Lipid droplets are cytoplasmic organelles that store neutral lipids and are critically important for energy metabolism. Their function in energy storage is firmly established and increasingly well characterized. However, emerging evidence indicates that lipid droplets also play important and diverse roles in the cellular handling of lipids and proteins that may not be directly related to energy homeostasis. Lipid handling roles of droplets include the storage of hydrophobic vitamin and signaling precursors, and the management of endoplasmic reticulum and oxidative stress. Roles of lipid droplets in protein handling encompass functions in the maturation, storage, and turnover of cellular and viral polypeptides. Other potential roles of lipid droplets may be connected with their intracellular motility and, in some cases, their nuclear localization. This diversity highlights that lipid droplets are very adaptable organelles, performing different functions in different biological contexts. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Michael A Welte
- Department of Biology, University of Rochester, Rochester, NY, United States.
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18
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Irina Stefana M, Driscoll PC, Obata F, Pengelly AR, MacRae JI, Gould AP. Coping with a stressful start in life. Mech Dev 2017. [DOI: 10.1016/j.mod.2017.04.541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Brandsma J, Bailey AP, Koster G, Gould AP, Postle AD. Stable isotope analysis of dynamic lipidomics. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:792-796. [PMID: 28302590 DOI: 10.1016/j.bbalip.2017.03.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [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: 12/16/2016] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 11/28/2022]
Abstract
Metabolic pathway flux is a fundamental element of biological activity, which can be quantified using a variety of mass spectrometric techniques to monitor incorporation of stable isotope-labelled substrates into metabolic products. This article contrasts developments in electrospray ionisation mass spectrometry (ESI-MS) for the measurement of lipid metabolism with more established gas chromatography mass spectrometry and isotope ratio mass spectrometry methodologies. ESI-MS combined with diagnostic tandem MS/MS scans permits the sensitive and specific analysis of stable isotope-labelled substrates into intact lipid molecular species without the requirement for lipid hydrolysis and derivatisation. Such dynamic lipidomic methodologies using non-toxic stable isotopes can be readily applied to quantify lipid metabolic fluxes in clinical and metabolic studies in vivo. However, a significant current limitation is the absence of appropriate software to generate kinetic models of substrate incorporation into multiple products in the time domain. Finally, we discuss the future potential of stable isotope-mass spectrometry imaging to quantify the location as well as the extent of lipid synthesis. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein.
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Affiliation(s)
- Joost Brandsma
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew P Bailey
- The Francis Crick Institute, 1 Midland Road, London, United Kingdom
| | - Grielof Koster
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; National Institute of Health Research Biomedical Research Unit in Respiratory Medicine, University Hospitals Southampton NHS Foundation Trust, United Kingdom
| | - Alex P Gould
- The Francis Crick Institute, 1 Midland Road, London, United Kingdom
| | - Anthony D Postle
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.
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20
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Cinnamon E, Makki R, Sawala A, Wickenberg LP, Blomquist GJ, Tittiger C, Paroush Z, Gould AP. Drosophila Spidey/Kar Regulates Oenocyte Growth via PI3-Kinase Signaling. PLoS Genet 2016; 12:e1006154. [PMID: 27500738 PMCID: PMC4976899 DOI: 10.1371/journal.pgen.1006154] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [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: 12/03/2015] [Accepted: 06/08/2016] [Indexed: 11/19/2022] Open
Abstract
Cell growth and proliferation depend upon many different aspects of lipid metabolism. One key signaling pathway that is utilized in many different anabolic contexts involves Phosphatidylinositide 3-kinase (PI3K) and its membrane lipid products, the Phosphatidylinositol (3,4,5)-trisphosphates. It remains unclear, however, which other branches of lipid metabolism interact with the PI3K signaling pathway. Here, we focus on specialized fat metabolizing cells in Drosophila called larval oenocytes. In the presence of dietary nutrients, oenocytes undergo PI3K-dependent cell growth and contain very few lipid droplets. In contrast, during starvation, oenocytes decrease PI3K signaling, shut down cell growth and accumulate abundant lipid droplets. We now show that PI3K in larval oenocytes, but not in fat body cells, functions to suppress lipid droplet accumulation. Several enzymes of fatty acid, triglyceride and hydrocarbon metabolism are required in oenocytes primarily for lipid droplet induction rather than for cell growth. In contrast, a very long chain fatty-acyl-CoA reductase (FarO) and a putative lipid dehydrogenase/reductase (Spidey, also known as Kar) not only promote lipid droplet induction but also inhibit oenocyte growth. In the case of Spidey/Kar, we show that the growth suppression mechanism involves inhibition of the PI3K signaling pathway upstream of Akt activity. Together, the findings in this study show how Spidey/Kar and FarO regulate the balance between the cell growth and lipid storage of larval oenocytes. Lipids play diverse roles in health and disease. Some types of lipids function as metabolic fuels for energy homeostasis, whereas others act as components of cell membranes or serve as signals regulating cell behaviors. Much, however, remains to be discovered about the molecular connections between different categories of lipids. Phosphatidylinositide 3-kinase (PI3K) is an enzyme that synthesizes phosphatidylinositide lipids, which act as signals essential for growth during normal development and cancer. Using genetics in the fruit fly, Drosophila, we identify new regulatory links between phosphatidylinositides and lipid oxidoreductases in specialized fat-metabolizing cells called oenocytes. We find that an enzyme metabolizing very long chain fatty acids (VLCFAs) and also a putative lipid dehydrogenase/reductase both act to prevent the inappropriate overgrowth of oenocytes. In the case of the latter enzyme, it suppresses cell growth by inhibiting phosphatidylinositide signaling. Future studies will determine whether similar lipid enzymes regulate PI3K signaling in other cell and tissue types during normal development and tumorigenesis.
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Affiliation(s)
- Einat Cinnamon
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, United Kingdom
| | - Rami Makki
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, United Kingdom
| | - Annick Sawala
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, United Kingdom
| | - Leah P. Wickenberg
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, Nevada, United States of America
| | - Gary J. Blomquist
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, Nevada, United States of America
| | - Claus Tittiger
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Reno, Nevada, United States of America
| | - Ze'ev Paroush
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel Canada (IMRIC), Faculty of Medicine, the Hebrew University, Jerusalem, Israel
| | - Alex P. Gould
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, United Kingdom
- * E-mail:
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21
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Bailey AP, Koster G, Guillermier C, Hirst EMA, MacRae JI, Lechene CP, Postle AD, Gould AP. Antioxidant Role for Lipid Droplets in a Stem Cell Niche of Drosophila. Cell 2016; 163:340-53. [PMID: 26451484 PMCID: PMC4601084 DOI: 10.1016/j.cell.2015.09.020] [Citation(s) in RCA: 387] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 06/15/2015] [Accepted: 08/12/2015] [Indexed: 12/19/2022]
Abstract
Stem cells reside in specialized microenvironments known as niches. During Drosophila development, glial cells provide a niche that sustains the proliferation of neural stem cells (neuroblasts) during starvation. We now find that the glial cell niche also preserves neuroblast proliferation under conditions of hypoxia and oxidative stress. Lipid droplets that form in niche glia during oxidative stress limit the levels of reactive oxygen species (ROS) and inhibit the oxidation of polyunsaturated fatty acids (PUFAs). These droplets protect glia and also neuroblasts from peroxidation chain reactions that can damage many types of macromolecules. The underlying antioxidant mechanism involves diverting PUFAs, including diet-derived linoleic acid, away from membranes to the core of lipid droplets, where they are less vulnerable to peroxidation. This study reveals an antioxidant role for lipid droplets that could be relevant in many different biological contexts. Oxidative stress stimulates lipid droplet biosynthesis in a neural stem cell niche Lipid droplets protect niche and neural stem cells from damaging PUFA peroxidation PUFAs are less vulnerable to peroxidation in lipid droplets than in cell membranes
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Affiliation(s)
- Andrew P Bailey
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Grielof Koster
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, Sir Henry Wellcome Laboratories, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Christelle Guillermier
- National Resource for Imaging Mass Spectroscopy, Harvard Medical School and Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | - Elizabeth M A Hirst
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - James I MacRae
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Claude P Lechene
- National Resource for Imaging Mass Spectroscopy, Harvard Medical School and Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | - Anthony D Postle
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, Sir Henry Wellcome Laboratories, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Alex P Gould
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK.
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22
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Prin F, Serpente P, Itasaki N, Gould AP. Hox proteins drive cell segregation and non-autonomous apical remodelling during hindbrain segmentation. Development 2014; 141:1492-502. [PMID: 24574009 PMCID: PMC3957373 DOI: 10.1242/dev.098954] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 01/22/2014] [Indexed: 01/26/2023]
Abstract
Hox genes encode a conserved family of homeodomain transcription factors regulating development along the major body axis. During embryogenesis, Hox proteins are expressed in segment-specific patterns and control numerous different segment-specific cell fates. It has been unclear, however, whether Hox proteins drive the epithelial cell segregation mechanism that is thought to initiate the segmentation process. Here, we investigate the role of vertebrate Hox proteins during the partitioning of the developing hindbrain into lineage-restricted units called rhombomeres. Loss-of-function mutants and ectopic expression assays reveal that Hoxb4 and its paralogue Hoxd4 are necessary and sufficient for cell segregation, and for the most caudal rhombomere boundary (r6/r7). Hox4 proteins regulate Eph/ephrins and other cell-surface proteins, and can function in a non-cell-autonomous manner to induce apical cell enlargement on both sides of their expression border. Similarly, other Hox proteins expressed at more rostral rhombomere interfaces can also regulate Eph/ephrins, induce apical remodelling and drive cell segregation in ectopic expression assays. However, Krox20, a key segmentation factor expressed in odd rhombomeres (r3 and r5), can largely override Hox proteins at the level of regulation of a cell surface target, Epha4. This study suggests that most, if not all, Hox proteins share a common potential to induce cell segregation but in some contexts this is masked or modulated by other transcription factors.
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Affiliation(s)
- Fabrice Prin
- Division of Physiology and Metabolism, Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Patricia Serpente
- Division of Physiology and Metabolism, Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Nobue Itasaki
- Division of Developmental Neurobiology, Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
| | - Alex P. Gould
- Division of Physiology and Metabolism, Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
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23
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Abstract
Oenocytes have intrigued insect physiologists since the nineteenth century. Many years of careful but mostly descriptive research on these cells highlights their diverse sizes, numbers, and anatomical distributions across Insecta. Contemporary molecular genetic studies in Drosophila melanogaster and Tribolium castaneum support the hypothesis that oenocytes are of ectodermal origin. They also suggest that, in both short and long germ-band species, oenocytes are induced from a Spalt major/Engrailed ectodermal zone by MAPK signaling. Recent glimpses into some of the physiological functions of oenocytes indicate that they involve fatty acid and hydrocarbon metabolism. Genetic studies in D. melanogaster have shown that larval oenocytes synthesize very-long-chain fatty acids required for tracheal waterproofing and that adult oenocytes produce cuticular hydrocarbons required for desiccation resistance and pheromonal communication. Exciting areas of future research include the evolution of oenocytes and their cross talk with other tissues involved in lipid metabolism such as the fat body.
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Affiliation(s)
- Rami Makki
- Division of Physiology and Metabolism, Medical Research Council, National Institute for Medical Research, London, NW7 1AA, United Kingdom;
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24
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Ragan TJ, Bailey AP, Gould AP, Driscoll PC. Volume determination with two standards allows absolute quantification and improved chemometric analysis of metabolites by NMR from submicroliter samples. Anal Chem 2013; 85:12046-54. [PMID: 24251761 PMCID: PMC3871890 DOI: 10.1021/ac403111s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [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: 01/18/2023]
Abstract
![]()
The accurate measurement of metabolite
concentrations in miniscule
biological sample volumes is often desirable, yet it remains challenging.
In many cases, the starting analyte volumes are imprecisely known,
or not directly measurable, and hence absolute metabolite concentrations
are difficult to calculate. Here, we introduce volume determination
using two standards (VDTS) as a general quantitative method for the
analysis of polar metabolites in submicrolitre samples using 1H NMR spectroscopy. This approach permits the back calculation
of absolute metabolite concentrations from small biological samples
of unknown volume. Where small sample volumes are also variable, VDTS
can improve multivariate chemometric analysis. In this context, principal
component analysis (PCA) yielded more logically consistent and biologically
insightful outputs when we used volume-corrected spectra, calculated
using VDTS, rather than probabilistic quotient normalization (PQN)
of raw spectra. As proof-of-principle, the VDTS-based method and PCA
were used to analyze polar metabolites in the hemolymph (blood) extracted
from larvae of the very small but widely used genetic model organism Drosophila. This analysis showed that the hemolymph metabolomes
of males and females are markedly different when larvae are well fed.
However, gender-specific metabolomes tend to converge when larval
dietary nutrients are restricted. We discuss the biological implications
of these surprising results and compare and contrast them to previous
analyses of Drosophila hemolymph and mammalian blood
plasma. Together, these findings reveal an interesting and hitherto
unknown sexual dimorphism in systemic Drosophila metabolites,
clearly warranting further biological investigation. Importantly,
the VDTS approach should be adaptable to many different analytical
platforms, including mass spectrometry.
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Affiliation(s)
- Timothy J Ragan
- Division of Molecular Structure, Medical Research Council National Institute for Medical Research , The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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25
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Breckenridge RA, Piotrowska I, Ng KE, Ragan TJ, West JA, Kotecha S, Towers N, Bennett M, Kienesberger PC, Smolenski RT, Siddall HK, Offer JL, Mocanu MM, Yelon DM, Dyck JRB, Griffin JL, Abramov AY, Gould AP, Mohun TJ. Hypoxic regulation of hand1 controls the fetal-neonatal switch in cardiac metabolism. PLoS Biol 2013; 11:e1001666. [PMID: 24086110 PMCID: PMC3782421 DOI: 10.1371/journal.pbio.1001666] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 08/15/2013] [Indexed: 12/15/2022] Open
Abstract
This study reveals a novel pathway that responds to hypoxia and modulates energy metabolism by cardiomyocytes in the mouse heart, thereby determining oxygen consumption. Cardiomyocytes are vulnerable to hypoxia in the adult, but adapted to hypoxia in utero. Current understanding of endogenous cardiac oxygen sensing pathways is limited. Myocardial oxygen consumption is determined by regulation of energy metabolism, which shifts from glycolysis to lipid oxidation soon after birth, and is reversed in failing adult hearts, accompanying re-expression of several “fetal” genes whose role in disease phenotypes remains unknown. Here we show that hypoxia-controlled expression of the transcription factor Hand1 determines oxygen consumption by inhibition of lipid metabolism in the fetal and adult cardiomyocyte, leading to downregulation of mitochondrial energy generation. Hand1 is under direct transcriptional control by HIF1α. Transgenic mice prolonging cardiac Hand1 expression die immediately following birth, failing to activate the neonatal lipid metabolising gene expression programme. Deletion of Hand1 in embryonic cardiomyocytes results in premature expression of these genes. Using metabolic flux analysis, we show that Hand1 expression controls cardiomyocyte oxygen consumption by direct transcriptional repression of lipid metabolising genes. This leads, in turn, to increased production of lactate from glucose, decreased lipid oxidation, reduced inner mitochondrial membrane potential, and mitochondrial ATP generation. We found that this pathway is active in adult cardiomyocytes. Up-regulation of Hand1 is protective in a mouse model of myocardial ischaemia. We propose that Hand1 is part of a novel regulatory pathway linking cardiac oxygen levels with oxygen consumption. Understanding hypoxia adaptation in the fetal heart may allow development of strategies to protect cardiomyocytes vulnerable to ischaemia, for example during cardiac ischaemia or surgery. Regulation of oxygen usage in cardiomyocytes is of great medical interest, because adult cardiac tissue is extremely vulnerable to hypoxia during myocardial infarction and cardiac surgery. While some progress has been made toward protecting cardiomyocytes from hypoxia in these circumstances, it has been limited by a lack of understanding of endogenous oxygen-sensing pathways. In contrast to adult cardiac tissue, embryonic cardiomyocytes are highly resistant to hypoxia, although the mechanisms underlying this have hitherto been unclear. Using mice we show that the transcription factor Hand1 is expressed at high levels in the fetal heart, under direct control of HIF1α signaling, a pathway well known to respond to hypoxia. We show that Hand1 expression decreases at birth as the neonate is exposed to higher levels of oxygen. By experimentally increasing Hand1 expression in the neonatal heart, we see lower oxygen consumption in cardiomyocytes and this is caused by Hand1 repressing key regulatory genes involved in cardiomyocyte lipid metabolism. This has the effect of decreasing mitochondrial ATP generation via the tricarboxylic acid cycle. Furthermore, we show that increasing Hand1 expression in adult transgenic hearts is protective against myocardial infarction, suggesting that a hypoxia–Hand1 pathway may also be of importance in the adult heart.
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Affiliation(s)
- Ross A. Breckenridge
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
- Division of Medicine, University College London, London, United Kingdom
- * E-mail:
| | - Izabela Piotrowska
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
| | - Keat-Eng Ng
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
| | - Timothy J. Ragan
- Division of Molecular Structure, MRC–National Institute for Medical Research, London, United Kingdom
| | - James A. West
- Department of Biochemistry, Cambridge University, Cambridge, United Kingdom
| | - Surendra Kotecha
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
| | - Norma Towers
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
| | - Michael Bennett
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
| | - Petra C. Kienesberger
- Cardiovascular Research Centre, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | | | - Hillary K. Siddall
- Hatter Institute, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - John L. Offer
- Physical Biochemistry, MRC–National Institute for Medical Research, London, United Kingdom
| | - Mihaela M. Mocanu
- Hatter Institute, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Derek M. Yelon
- Hatter Institute, Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Jason R. B. Dyck
- Cardiovascular Research Centre, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jules L. Griffin
- Department of Biochemistry, Cambridge University, Cambridge, United Kingdom
| | - Andrey Y. Abramov
- Institute of Neurology, University College London, London, United Kingdom
| | - Alex P. Gould
- Division of Physiology and Metabolism, MRC–National Institute for Medical Research, London, United Kingdom
| | - Timothy J. Mohun
- Developmental Biology, MRC–National Institute for Medical Research, London, United Kingdom
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Gould AP. An Address ON MODERN ANTISEPTICS: Delivered at a Meeting of the Hunterian Society on November 7th, 1917. Br Med J 2011; 2:677-9. [PMID: 20768815 DOI: 10.1136/bmj.2.2969.677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Gould AP. An Address ON RADIUM AND CANCER: Delivered at the Annual Meeting of the West Somerset Branch of the British Medical Association, at Taunton, on December 9th. Br Med J 2011; 1:1-6. [PMID: 20766932 DOI: 10.1136/bmj.1.2766.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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28
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Gould AP. The Bradshaw Lecture ON CANCER: Delivered at the Royal College of Surgeons of England on Wednesday, December 7th, 1910. Br Med J 2011; 2:1836-44. [PMID: 20765351 DOI: 10.1136/bmj.2.2606.1836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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29
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Grant J, Saldanha JW, Gould AP. A Drosophila model for primary coenzyme Q deficiency and dietary rescue in the developing nervous system. Dis Model Mech 2010; 3:799-806. [PMID: 20889762 DOI: 10.1242/dmm.005579] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Coenzyme Q (CoQ) or ubiquinone is a lipid component of the electron transport chain required for ATP generation in mitochondria. Mutations in CoQ biosynthetic genes are associated with rare but severe infantile multisystemic diseases. CoQ itself is a popular over-the-counter dietary supplement that some clinical and rodent studies suggest might be beneficial for neurodegenerative diseases. Here, we identify mutations in the Drosophila qless gene, which encodes an orthologue of the human PDSS1 prenyl transferase that synthesizes the isoprenoid side chain of CoQ. We show that neurons lacking qless activity upregulate markers of mitochondrial stress and undergo caspase-dependent apoptosis. Surprisingly, even though experimental inhibition of caspase activity did not prevent mitochondrial disruption, it was sufficient to rescue the size of neural progenitor clones. This demonstrates that, within the developing larval CNS, qless activity is required primarily for cell survival rather than for cell growth and proliferation. Full rescue of the qless neural phenotype was achieved by dietary supplementation with CoQ4, CoQ9 or CoQ10, indicating that a side chain as short as four isoprenoid units can provide in vivo activity. Together, these findings show that Drosophila qless provides a useful model for studying the neural effects of CoQ deficiency and dietary supplementation.
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Affiliation(s)
- Jennifer Grant
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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Zhu D, Jarmin S, Ribeiro A, Prin F, Xie SQ, Sullivan K, Briscoe J, Gould AP, Marelli-Berg FM, Gu Y. Applying an adaptive watershed to the tissue cell quantification during T-cell migration and embryonic development. Methods Mol Biol 2010; 616:207-228. [PMID: 20379878 DOI: 10.1007/978-1-60761-461-6_14] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cell and particle quantification is one of the frequently used techniques in biology and clinical study. Variations of cell/particle population and/or protein expression level can provide information on many biological processes. In this chapter, we propose an image-based automatic quantification approach that can be applied to images from both fluorescence and electron microscopy. The algorithm uses local maxima to identify labelling targets and uses watershed segmentation to define their boundaries. The method is able to provide information on size, intensity centroids and average intensity within the labelling partitions. Further developed from this method, we demonstrated its applications in four different research projects, including recruitment enumeration of circulating T cell in non-lymphoid tissues, cell clustering in the early development of the chick embryo, gold particle localization and clustering in electron microscopy, and registration/co-localization of transcription factors in neural tube development of early chick embryo. The advantages and limitations of the method are also discussed.
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Affiliation(s)
- D Zhu
- Developmental Neurobiology, National Institute for Medical Research, MRC, London, UK
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31
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Cheng L, Bailey A, Gould AP. 02-P005 A mechanism for “brain sparing” during dietary restriction in Drosophila. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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32
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Abstract
It is well established in species as diverse as insects and mammals that different neuronal and glial subtypes are born at distinct times during central nervous system development. In Drosophila, there is now compelling evidence that individual multipotent neuroblasts express a sequence of progenitor transcription factors which, in turn, regulates the postmitotic transcription factors that specify neuronal/glial temporal identities. Here,we examine the hypothesis that the regulatory principles underlying this mode of temporal specification are shared between insects and mammals, even if some of the factors themselves are not. We also propose a general model for birth-order-dependent neural specification and suggest some experiments to test its validity.
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Affiliation(s)
- John Jacob
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
- National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Cédric Maurange
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Alex P. Gould
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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33
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Maurange C, Cheng L, Gould AP. Temporal transcription factors and their targets schedule the end of neural proliferation in Drosophila. Cell 2008; 133:891-902. [PMID: 18510932 DOI: 10.1016/j.cell.2008.03.034] [Citation(s) in RCA: 245] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 01/29/2008] [Accepted: 03/25/2008] [Indexed: 12/25/2022]
Abstract
The timing mechanisms responsible for terminating cell proliferation toward the end of development remain unclear. In the Drosophila CNS, individual progenitors called neuroblasts are known to express a series of transcription factors endowing daughter neurons with different temporal identities. Here we show that Castor and Seven-Up, members of this temporal series, regulate key events in many different neuroblast lineages during late neurogenesis. First, they schedule a switch in the cell size and identity of neurons involving the targets Chinmo and Broad Complex. Second, they regulate the time at which neuroblasts undergo Prospero-dependent cell-cycle exit or Reaper/Hid/Grim-dependent apoptosis. Both types of progenitor termination require the combined action of a late phase of the temporal series and indirect feedforward via Castor targets such as Grainyhead and Dichaete. These studies identify the timing mechanism ending CNS proliferation and reveal how aging progenitors transduce bursts of transcription factors into long-lasting changes in cell proliferation and cell identity.
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Affiliation(s)
- Cédric Maurange
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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34
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Abstract
Insulin and related peptides play important and conserved functions in growth and metabolism. Although Drosophila has proved useful for the genetic analysis of insulin functions, little is known about the transcription factors and cell lineages involved in insulin production. Within the embryonic central nervous system, the MP2 neuroblast divides once to generate a dMP2 neuron that initially functions as a pioneer, guiding the axons of other later-born embryonic neurons. Later during development, dMP2 neurons in anterior segments undergo apoptosis but their posterior counterparts persist. We show here that surviving posterior dMP2 neurons no longer function in axonal scaffolding but differentiate into neuroendocrine cells that express insulin-like peptide 7 (Ilp7) and innervate the hindgut. We find that the postmitotic transition from pioneer to insulin-producing neuron is a multistep process requiring retrograde bone morphogenetic protein (BMP) signalling and four transcription factors: Abdominal-B, Hb9, Fork Head, and Dimmed. These five inputs contribute in a partially overlapping manner to combinatorial codes for dMP2 apoptosis, survival, and insulinergic differentiation. Ectopic reconstitution of this code is sufficient to activate Ilp7 expression in other postmitotic neurons. These studies reveal striking similarities between the transcription factors regulating insulin expression in insect neurons and mammalian pancreatic β-cells. Genetic studies using invertebrate model organisms such as Drosophila have provided many new insights into the functions of insulin and related peptides. It has, however, been more difficult to use Drosophila to study the regulation of insulin, at least in part because the relevant insulinergic cell lineages were not well characterised. Here, we have identified a cell lineage that generates a single Drosophila insulin-producing neuron. This neuron first functions as a pioneer, guiding the axons of other neurons within the central nervous system of the embryo. It then develops long axons that exit the central nervous system to innervate the gut and also begins to express an insulin-like peptide. Genetic analysis identifies four transcription factors and one extrinsic signal that instruct the pioneer neuron to become an insulin-producing neuron. The analysis also reveals similarities between the genetic programmes specifying insulin production by Drosophila neurons and mammalian pancreatic ß-cells. This suggests that Drosophila may, in the future, prove a useful model system for identifying new regulators of human insulin production. A genetic analysis in the fruit fly reveals similarities between the transcriptional programmes regulating insulin production in mammalian pancreatic β-cells and insect neurons.
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Affiliation(s)
- Irene Miguel-Aliaga
- Division of Developmental Neurobiology, Medical Research Council National Institute for Medical Research, London, United Kingdom
- * To whom correspondence should be addressed. E-mail: (IMA); (APG)
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University Medical School, Linkoping, Sweden
| | - Alex P Gould
- Division of Developmental Neurobiology, Medical Research Council National Institute for Medical Research, London, United Kingdom
- * To whom correspondence should be addressed. E-mail: (IMA); (APG)
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35
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Gutierrez E, Wiggins D, Fielding B, Gould AP. Specialized hepatocyte-like cells regulate Drosophila lipid metabolism. Nature 2006; 445:275-80. [PMID: 17136098 DOI: 10.1038/nature05382] [Citation(s) in RCA: 289] [Impact Index Per Article: 16.1] [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] [Received: 07/22/2006] [Accepted: 10/23/2006] [Indexed: 12/22/2022]
Abstract
Lipid metabolism is essential for growth and generates much of the energy needed during periods of starvation. In Drosophila, fasting larvae release large quantities of lipid from the fat body but it is unclear how and where this is processed. Here we identify the oenocyte as the principal cell type accumulating lipid droplets during starvation. Tissue-specific manipulations of the Slimfast amino-acid channel, the Lsd2 fat-storage regulator and the Brummer lipase indicate that oenocytes act downstream of the fat body. In turn, oenocytes are required for depleting stored lipid from the fat body during fasting. Hence, lipid-metabolic coupling between the fat body and oenocytes is bidirectional. When food is plentiful, oenocytes have critical roles in regulating growth, development and feeding behaviour. In addition, they specifically express many different lipid-metabolizing proteins, including Cyp4g1, an omega-hydroxylase regulating triacylglycerol composition. These findings provide evidence that some lipid-processing functions of the mammalian liver are performed in insects by oenocytes.
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Affiliation(s)
- Eugenio Gutierrez
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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36
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Cenci C, Gould AP. DrosophilaGrainyhead specifies late programmes of neural proliferation by regulating the mitotic activity and Hox-dependent apoptosis of neuroblasts. Development 2005; 132:3835-45. [PMID: 16049114 DOI: 10.1242/dev.01932] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [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
The Drosophila central nervous system is generated by stem-cell-like progenitors called neuroblasts. Early in development,neuroblasts switch through a temporal series of transcription factors modulating neuronal fate according to the time of birth. At later stages, it is known that neuroblasts switch on expression of Grainyhead (Grh) and maintain it through many subsequent divisions. We report that the function of this conserved transcription factor is to specify the regionalised patterns of neurogenesis that are characteristic of postembryonic stages. In the thorax,Grh prolongs neural proliferation by maintaining a mitotically active neuroblast. In the abdomen, Grh terminates neural proliferation by regulating the competence of neuroblasts to undergo apoptosis in response to Abdominal-A expression. This study shows how a factor specific to late-stage neural progenitors can regulate the time at which neural proliferation stops, and identifies mechanisms linking it to the Hox axial patterning system.
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Affiliation(s)
- Caterina Cenci
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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37
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Abstract
Drosophila neuroblasts are similar to mammalian neural stem cells in that they self-renew and have the potential to generate many different types of neurons and glia. They have already proved useful for uncovering asymmetric division components and now look set to provide insights into how stem cell divisions are initiated and terminated during neural development. In particular, some of the humoral factors and short-range 'niche' signals that modulate neuroblast activity during postembryonic development have been identified. In addition, recent studies have begun to reveal how the total number of cells generated by a single neuroblast is regulated by spatial and temporal cues from Hox proteins and a transcription-factor series linked to cell cycle progression.
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Affiliation(s)
- Cédric Maurange
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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38
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Serpente P, Tümpel S, Ghyselinck NB, Niederreither K, Wiedemann LM, Dollé P, Chambon P, Krumlauf R, Gould AP. Direct crossregulation between retinoic acid receptor β and Hox genes during hindbrain segmentation. Development 2005; 132:503-13. [PMID: 15634700 DOI: 10.1242/dev.01593] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [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: 11/20/2022]
Abstract
During anteroposterior (AP) patterning of the developing hindbrain, the expression borders of many transcription factors are aligned at interfaces between neural segments called rhombomeres (r). Mechanisms regulating segmental expression have been identified for Hox genes, but for other classes of AP patterning genes there is only limited information. We have analysed the murine retinoic acid receptor β gene (Rarb) and show that it is induced prior to segmentation, by retinoic-acid (RA) signalling from the mesoderm. Induction establishes a diffuse expression border that regresses until, at later stages, it is stably maintained at the r6/r7 boundary by inputs from Hoxb4 and Hoxd4. Separate RA- and Hox-responsive enhancers mediate the two phases of Rarb expression: a regulatory mechanism remarkably similar to that of Hoxb4. By showing that Rarb is a direct transcriptional target of Hoxb4, this study identifies a new molecular link, completing a feedback circuit between Rarb, Hoxb4 and Hoxd4. We propose that the function of this circuit is to align the initially incongruent expression of multiple RA-induced genes at a single segment boundary.
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MESH Headings
- Aldehyde Oxidoreductases/genetics
- Aldehyde Oxidoreductases/metabolism
- Animals
- Base Sequence
- Binding Sites
- Chickens
- Embryo, Mammalian/cytology
- Embryo, Mammalian/embryology
- Embryo, Mammalian/metabolism
- Embryo, Nonmammalian
- Enhancer Elements, Genetic/genetics
- Gene Expression Regulation, Developmental
- Homeodomain Proteins/chemistry
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- Mice
- Mice, Knockout
- Molecular Sequence Data
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism
- Rhombencephalon/cytology
- Rhombencephalon/embryology
- Rhombencephalon/metabolism
- Sequence Alignment
- Time Factors
- Transcription Factors/chemistry
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Tretinoin/metabolism
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Affiliation(s)
- Patricia Serpente
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
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39
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Brodu V, Elstob PR, Gould AP. EGF Receptor Signaling Regulates Pulses of Cell Delamination from the Drosophila Ectoderm. Dev Cell 2004; 7:885-95. [PMID: 15572130 DOI: 10.1016/j.devcel.2004.10.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [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] [Received: 05/13/2004] [Revised: 08/26/2004] [Accepted: 10/07/2004] [Indexed: 10/26/2022]
Abstract
Many different intercellular signaling pathways are known but, for most, it is unclear whether they can generate oscillating cell behaviors. Here we use time-lapse analysis of Drosophila embryogenesis to show that oenocytes delaminate from the ectoderm in discrete bursts of three. This pulsatile process has a 1 hour period, occurs without cell division, and requires a localized EGF receptor (EGFR) response. High-threshold EGFR targets are sequentially activated in rings of three cells, prefiguring the temporal pattern of delamination. Surprisingly, widespread misexpression of the relevant activating ligand, Spitz, is compatible with robust delamination pulses. Moreover, although Spitz ligand becomes limiting after only two pulses, artificially prolonging its secretion generates up to six additional cycles, revealing a rhythmic underlying mechanism. These findings illustrate how intercellular signaling and cell movements can generate multiple cycles of a cell behavior, despite individual cells experiencing only one cycle of receptor activation.
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Affiliation(s)
- Véronique Brodu
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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40
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Abstract
Postembryonic neuroblasts are stem cell-like precursors that generate most neurons of the adult Drosophila central nervous system (CNS). Their capacity to divide is modulated along the anterior-posterior body axis, but the mechanism underlying this is unclear. We use clonal analysis of identified precursors in the abdomen to show that neuron production stops because the cell death program is activated in the neuroblast while it is still engaged in the cell cycle. A burst of expression of the Hox protein Abdominal-A (AbdA) specifies the time at which apoptosis occurs, thereby determining the final number of progeny that each neuroblast generates. These studies identify a mechanism linking the Hox axial patterning system to neural proliferation, and this involves temporal regulation of precursor cell death rather than the cell cycle.
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Affiliation(s)
- Bruno C Bello
- Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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41
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Abstract
The Hox/homeotic genes encode transcription factors that generate segmental diversity during Drosophila development. At the level of the whole animal, they are believed to carry out this role by regulating a large number of downstream genes. Here we address the unresolved issue of how many Hox target genes are sufficient to define the identity of a single cell. We focus on the larval oenocyte, which is restricted to the abdomen and induced in response to a non-cell autonomous, transient and highly selective input from abdominal A (abdA). We use Hox mutant rescue assays to demonstrate that this function of abdA can be reconstituted by providing Rhomboid (Rho), a processing factor for the EGF receptor ligand, secreted Spitz. Thus, in order to make an oenocyte, abdA regulates just one principal target, rho, that acts at the top of a complex hierarchy of cell-differentiation genes. These studies strongly suggest that, in at least some contexts, Hox genes directly control only a few functional targets within each nucleus. This raises the possibility that much of the overall Hox downstream complexity results from cascades of indirect regulation and cell-to-cell heterogeneity.
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Affiliation(s)
- Véronique Brodu
- Medical Research Council, National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
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42
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Gould AP. Gravitational microlens in motion. Nature 2001; 414:591, 593. [PMID: 11740540 DOI: 10.1038/414591a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
During insect development, morphological differences between segments are controlled by the Hox gene family of transcription factors. Recent evidence also suggests that variation in the regulatory elements of these genes and their downstream targets underlies the evolution of several segment-specific morphological traits. This review introduces a new model system, the larval oenocyte, for studying the evolution of fate specification by Hox genes at single-cell resolution. Oenocytes are found in a wide range of insects, including species using both the short and the long germ modes of development. Recent progress in our understanding of the genetics and cell biology of oenocyte development in the fruitfly Drosophila melanogaster is discussed. In the D. melanogaster embryo, the formation of this cell type is restricted to the first 7 abdominal segments and is under Hox gene control. Oenocytes delaminate from the dorsal ectoderm of A1-A7 in response to an induction that involves the epidermal growth factor receptor (EGFR) signalling pathway. Although the receptor itself is required in the presumptive oenocytes, its ligand Spitz (Spi) is secreted by a neighbouring chordotonal organ precursor (COP). Thus, in dorsal regions, local signalling from this component of the developing peripheral nervous system induces the formation of oenocytes. In contrast, in lateral regions of the ectoderm, Spi signal from a different COP induces the formation of secondary COPs in a homeogenetic manner. This dorsoventral difference in the fate induced by Spi ligand is controlled by a prepattern in the responding ectoderm that requires the Spalt (Sal) transcription factor. Sal protein is expressed in the dorsal but not lateral ectoderm and acts as a competence modifier to bias the response to Spi ligand in favour of the oenocyte fate. We discuss a recently proposed model that integrates the roles of Sal and the EGFR pathway in oenocyte/chordotonal organ induction. This model should provide a useful starting point for future comparative studies of these ectodermal derivatives in other insects.
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Affiliation(s)
- A P Gould
- Medical Research Council, National Institute for Medical Research, London, UK.
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44
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Abstract
Signaling from the EGF receptor (EGFR) can trigger the differentiation of a wide variety of cell types in many animal species. We have explored the mechanisms that generate this diversity using the Drosophila peripheral nervous system. In this context, Spitz (SPI) ligand can induce two alternative cell fates from the dorsolateral ectoderm: chordotonal sensory organs and non-neural oenocytes. We show that the overall number of both cell types that are induced is controlled by the degree of EGFR signaling. In addition, the spalt (sal) gene is identified as a critical component of the oenocyte/chordotonal fate switch. Genetic and expression analyses indicate that the SAL zinc-finger protein promotes oenocyte formation and supresses chordotonal organ induction by acting both downstream and in parallel to the EGFR. To explain these findings, we propose a prime-and-respond model. Here, sal functions prior to signaling as a necessary but not sufficient component of the oenocyte prepattern that also serves to raise the apparent threshold for induction by SPI. Subsequently, sal-dependent SAL upregulation is triggered as part of the oenocyte-specific EGFR response. Thus, a combination of SAL in the responding nucleus and increased SPI ligand production sets the binary cell-fate switch in favour of oenocytes. Together, these studies help to explain how one generic signaling pathway can trigger the differentiation of two distinct cell types.
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Affiliation(s)
- P R Elstob
- Medical Research Council, National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
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45
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Graff DS, Gould AP. High-Velocity Star Formation in the Large Magellanic Cloud. Astrophys J 2000; 534:L51-L52. [PMID: 10790069 DOI: 10.1086/312647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2000] [Accepted: 03/10/2000] [Indexed: 05/23/2023]
Abstract
Light-echo measurements show that SN 1987A is 425 pc behind the LMC disk. It is continuing to move away from the disk at 18 km s-1. Thus, it has been suggested that SN 1987A was ejected from the LMC disk. However, SN 1987A is a member of a star cluster, so this entire cluster would have to have been ejected from the disk. We show that the cluster was formed in the LMC disk, with a velocity perpendicular to the disk of about 50 km s-1. Such high-velocity formation of a star cluster is unusual, having no known counterpart in the Milky Way.
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46
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Dittrich R, Bossing T, Gould AP, Technau GM, Urban J. The differentiation of the serotonergic neurons in the Drosophila ventral nerve cord depends on the combined function of the zinc finger proteins Eagle and Huckebein. Development 1997; 124:2515-25. [PMID: 9216994 DOI: 10.1242/dev.124.13.2515] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [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: 11/20/2022]
Abstract
The Drosophila ventral nerve cord (vNC) derives from a stereotyped population of neural stem cells, neuroblasts (NBs), each of which gives rise to a characteristic cell lineage. The mechanisms leading to the specification and differentiation of these lineages are largely unknown. Here we analyse mechanisms leading to cell differentiation within the NB 7–3 lineage. Analogous to the grasshopper, NB 7–3 is the progenitor of the Drosophila vNC serotonergic neurons. The zinc finger protein Eagle (Eg) is expressed in NB 7–3 just after delamination and is present in all NB 7–3 progeny until late stage 17. DiI cell lineage tracing and immunocytochemistry reveal that eg is required for normal pathfinding of interneuronal projections and for restricting the cell number in the thoracic NB 7–3 lineage. Moreover, eg is required for serotonin expression. Ectopic expression of Eg protein forces specific additional CNS cells to enter the serotonergic differentiation pathway. Like NB 7–3, the progenitor(s) of these ectopic cells express Huckebein (Hkb), another zinc finger protein. However, their progenitors do not express engrailed (en) as opposed to the NB 7–3 lineage, where en acts upstream of eg. We conclude that eg and hkb act in concert to determine serotonergic cell fate, while en is more distantly involved in this process by activating eg expression. Thus, we provide the first functional evidence for a combinatorial code of transcription factors acting early but downstream of segment polarity genes to specify a unique neuronal cell fate.
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Affiliation(s)
- R Dittrich
- Institut für Genetik, Universität Mainz, Germany
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Meadows LA, Gell D, Broadie K, Gould AP, White RA. The cell adhesion molecule, connectin, and the development of the Drosophila neuromuscular system. J Cell Sci 1994; 107 ( Pt 1):321-8. [PMID: 8175919 DOI: 10.1242/jcs.107.1.321] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [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: 11/20/2022] Open
Abstract
The connectin gene of Drosophila has been identified as a candidate direct target of homeotic gene control and has also been implicated in the formation of specific neuromuscular connections. The gene product, connectin, is a member of the leucine-rich repeat protein family and we show that it is attached to the cell surface via a glycosylphosphatidylinositol linkage and that it can mediate homotypic cell-cell adhesion in vitro. The expression of connectin protein during Drosophila embryogenesis provides support for a role in adhesion in vivo. In the central nervous system, it is initially expressed on longitudinal glia and on a few identified neurons. These cells extend processes and connect up to form a continuous scaffold of connectin-expressing cells, presaging the development of axonal pathways. Later, connectin is expressed on specific axons as they track along the connectin scaffold. Glial expression then declines and connectin appears on axons that fasciculate with pre-existing connectin-positive bundles. Thus scaffold formation, axon pathfinding and fasciculation involve specific contacts between connectin-positive cells. The timing and pattern of connectin expression suggest that it may play an important role in mediating specific interactions through homotypic cell adhesion.
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Affiliation(s)
- L A Meadows
- Department of Anatomy, University of Cambridge, UK
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Abstract
We have used a chromatin immunopurification approach to identify target genes regulated by the homeotic gene Ultrabithorax. A monoclonal antibody against the Ultrabithorax gene product is used to immunopurify in vivo Ultrabithorax protein binding sites in embryonic chromatin. The procedure gives an enrichment of sequences with matches to a consensus homeodomain binding site. In one case we have shown that an immunopurified sequence lies within a 4 kb fragment that acts in vivo as a homeotic response element. We anticipate that this approach will enable us to identify further targets, allowing the analysis of their regulation and function. The chromatin immunopurification strategy may be of general application for the identification of direct in vivo targets of DNA-binding proteins.
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Affiliation(s)
- R A White
- Department of Anatomy, University of Cambridge, UK
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Abstract
The homeotic genes of Drosophila encode transcription factors that specify morphological differences between segments. To identify the genes that they control, we developed a chromatin immunopurification approach designed to isolate in vivo binding sites for the products of the homeotic gene Ultrabithorax. Here, we report the analysis of one immunopurified binding site. This 110 bp fragment maps within a regulatory region of a gene under homeotic control, connectin. A 4 kb DNA fragment, including the immunopurified binding site, is sufficient to reproduce the appropriate homeotic control within a subset of the full tissue distribution of connectin. Analysis of the role of the 110 bp binding site indicates that it mediates transcriptional controls by Ultrabithorax and other homeotic genes. This is the first report of a functional in vivo binding site isolated using the chromatin immunopurification method. We also show that the protein product of the connectin gene is predicted to be a cell-surface molecule containing leucine-rich repeats. The protein, connectin, can mediate cell-cell adhesion thus suggesting a direct link between homeotic gene function and processes of cell-cell recognition.
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Affiliation(s)
- A P Gould
- Department of Anatomy, University of Cambridge, UK
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Gould AP, Lai RY, Green MJ, White RA. Blocking cell division does not remove the requirement for Polycomb function in Drosophila embryogenesis. Development 1990. [PMID: 1983118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Polycomb (Pc) gene is required from the extended germ band stage onwards, to maintain spatially restricted patterns of homeotic gene expression. It has been thought to be involved in the 'stable inheritance of the determined state'. In this paper, we have tested the notion that the Pc gene is required specifically during or after DNA replication to enable the stable transmission of states of gene activity. We found that arresting cell division using the string mutation or blocking DNA replication with aphidicolin failed to prevent ectopic expression of the homeotic gene Ultrabithorax in Pc mutants. Thus, even in the absence of DNA replication, Pc is required to maintain spatially restricted patterns of homeotic gene expression. The role of the Pc gene product in the stable repression of homeotic gene transcription is discussed.
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Affiliation(s)
- A P Gould
- Department of Anatomy, University of Cambridge, UK
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