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Poirier KM, Luallen RJ, Rivera DE. RNA fluorescence in situ hybridization (FISH) as a method to visualize bacterial colonization in the C. elegans gut. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001044. [PMID: 38481555 PMCID: PMC10935869 DOI: 10.17912/micropub.biology.001044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/05/2024] [Accepted: 02/25/2024] [Indexed: 03/17/2024]
Abstract
Caenorhabditis elegans is an excellent model to study host-microbe interactions as it is easy to visualize bacterial presence in their intestine. However, previous studies have shown that utilizing transgenic, fluorescent protein-expressing bacteria is not a reliable method to distinguish living bacteria from dead bacteria in the lumen of C. elegans . In this study, we compared methods for visualizing bacterial presence within the C. elegans intestine and found that RNA f luorescent i n s itu h ybridization (RNA FISH) could distinguish the difference between intact and dead bacteria. Thus, we propose RNA FISH as the preferred method to visualize live bacterial presence in the intestines of C. elegans prior to fixation.
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Affiliation(s)
- Kayla M Poirier
- Department of Biology, San Diego State University, San Diego, California, United States
| | - Robert J Luallen
- Department of Biology, San Diego State University, San Diego, California, United States
| | - Dalaena E Rivera
- Department of Biology, San Diego State University, San Diego, California, United States
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2
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Brandel-Ankrapp KL, Arey RN. Uncovering novel regulators of memory using C. elegans genetic and genomic analysis. Biochem Soc Trans 2023; 51:161-171. [PMID: 36744642 PMCID: PMC10518207 DOI: 10.1042/bst20220455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/20/2022] [Accepted: 01/19/2023] [Indexed: 02/07/2023]
Abstract
How organisms learn and encode memory is an outstanding question in neuroscience research. Specifically, how memories are acquired and consolidated at the level of molecular and gene pathways remains unclear. In addition, memory is disrupted in a wide variety of neurological disorders; therefore, discovering molecular regulators of memory may reveal therapeutic targets for these disorders. C. elegans are an excellent model to uncover molecular and genetic regulators of memory. Indeed, the nematode's invariant neuronal lineage, fully mapped genome, and conserved associative behaviors have allowed the development of a breadth of genetic and genomic tools to examine learning and memory. In this mini-review, we discuss novel and exciting genetic and genomic techniques used to examine molecular and genetic underpinnings of memory from the level of the whole-worm to tissue-specific and cell-type specific approaches with high spatiotemporal resolution.
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Affiliation(s)
- Katie L. Brandel-Ankrapp
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, U.S.A
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX 77030, U.S.A
| | - Rachel N. Arey
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX 77030, U.S.A
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, U.S.A
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3
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Pandey T, Ma DK. Stress-Induced Phenoptosis: Mechanistic Insights and Evolutionary Implications. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1504-1511. [PMID: 36717459 DOI: 10.1134/s0006297922120082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Evolution by natural selection results in biological traits that enable organismic adaptation and survival under various stressful environments. External stresses can be sometimes too severe to overcome, leading to organismic death either because of failure in adapting to such stress, or alternatively, through a regulated form of organismic death (phenoptosis). While regulated cell deaths, including apoptosis, have been extensively studied, little is known about the molecular and cellular mechanisms underlying phenoptosis and its evolutionary significance for multicellular organisms. In this article, we review documented phenomena and mechanistic evidence emerging from studies of stress-induced phenoptosis in the multicellular organism C. elegans and stress-induced deaths at cellular levels in organisms ranging from bacteria to mammals, focusing on abiotic and pathogen stresses. Genes and signaling pathways involved in phenoptosis appear to promote organismic death during severe stress and aging, while conferring fitness and immune defense during mild stress and early life, consistent with their antagonistic pleiotropy actions. As cell apoptosis during development can shape tissues and organs, stress-induced phenoptosis may also contribute to possible benefits at the population level, through mechanisms including kin selection, abortive infection, and soma-to-germline resource allocation. Current models can generate experimentally testable predictions and conceptual frameworks with implications for understanding both stress-induced phenoptosis and natural aging.
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Affiliation(s)
- Taruna Pandey
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, USA.
| | - Dengke K Ma
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, USA. .,Innovative Genomics Institute, University of California, Berkeley, USA
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4
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Reproductive Span of Caenorhabditis elegans Is Extended by Microbacterium sp. J Nematol 2022; 54:20220010. [PMID: 35860519 PMCID: PMC9260829 DOI: 10.2478/jofnem-2022-0010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Indexed: 11/20/2022] Open
Abstract
Abstract
The reproductive span (RS) of organisms could be affected by different factors during their lifetime. In the model nematode, Caenorhabditis elegans, RS is affected by both genetic and environmental factors. However, none of the factors identified so far were related to environmental bacteria, which may incidentally appear anywhere in the habitats of C. elegans. We aimed to find environmental bacteria that could affect the RS of C. elegans and related species. We tested 109 bacterial isolates and found that Microbacterium sp. CFBb37 increased the RS and lifespan of C. elegans but reduced its brood size. We studied the effect of M. sp. CFBb37 on the RS of Caenorhabditis briggsae, Caenorhabditis tropicalis, and another Rhabditidae family species, Protorhabditis sp., and found similar trends of RS extension in all three cases, suggesting that this bacterial species may induce the extension of RS broadly among Caenorhabditis species and possibly for many other Rhabditidae. This work will facilitate future research on the mechanism underlying the bacterial extension of RS of nematodes and possibly other animals.
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5
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Ohno H, Bao Z. Small RNAs couple embryonic developmental programs to gut microbes. SCIENCE ADVANCES 2022; 8:eabl7663. [PMID: 35319987 PMCID: PMC8942359 DOI: 10.1126/sciadv.abl7663] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Embryogenesis has long been known for its robustness to environmental factors. Although developmental tuning of embryogenesis to the environment experienced by the parent may be beneficial, little is understood on whether and how developmental patterns proactively change. Here, we show that Caenorhabditis elegans undergoes alternative embryogenesis in response to maternal gut microbes. Harmful microbes result in altered endodermal cell divisions; morphological changes, including left-right asymmetric development; double association between intestinal and primordial germ cells; and partial rescue of fecundity. The miR-35 microRNA family, which is controlled by systemic endogenous RNA interference and targets the β-transducin repeat-containing protein/cell division cycle 25 (CDC25) pathway, transmits intergenerational information to regulate cell divisions and reproduction. Our findings challenge the widespread assumption that C. elegans has an invariant cell lineage that consists of a fixed cell number and provide insights into how organisms optimize embryogenesis to adapt to environmental changes through epigenetic control.
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6
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Dinić M, Jakovljević S, Đokić J, Popović N, Radojević D, Strahinić I, Golić N. Probiotic-mediated p38 MAPK immune signaling prolongs the survival of Caenorhabditis elegans exposed to pathogenic bacteria. Sci Rep 2021; 11:21258. [PMID: 34711881 PMCID: PMC8553853 DOI: 10.1038/s41598-021-00698-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/15/2021] [Indexed: 11/18/2022] Open
Abstract
The host-microbiota cross-talk represents an important factor contributing to innate immune response and host resistance during infection. It has been shown that probiotic lactobacilli exhibit the ability to modulate innate immunity and enhance pathogen elimination. Here we showed that heat-inactivated probiotic strain Lactobacillus curvatus BGMK2-41 stimulates immune response and resistance of the Caenorhabditis elegans against Staphylococcus aureus and Pseudomonas aeruginosa. By employing qRT-PCR and western blot analysis we showed that heat-inactivated BGMK2-41 activated PMK-1/p38 MAPK immunity pathway which prolongs the survival of C. elegans exposed to pathogenic bacteria in nematode killing assays. The C. elegans pmk-1 mutant was used to demonstrate a mechanistic basis for the antimicrobial potential of BGMK2-41, showing that BGMK2-41 upregulated PMK-1/p38 MAPK dependent transcription of C-type lectins, lysozymes and tight junction protein CLC-1. Overall, this study suggests that PMK-1/p38 MAPK-dependent immune regulation by BGMK2-41 is essential for probiotic-mediated C. elegans protection against gram-positive and gram-negative bacteria and could be further explored for development of probiotics with the potential to increase resistance of the host towards pathogens.
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Affiliation(s)
- Miroslav Dinić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia.
| | - Stefan Jakovljević
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
| | - Jelena Đokić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
| | - Nikola Popović
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
| | - Dušan Radojević
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
| | - Ivana Strahinić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
| | - Nataša Golić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Belgrade, Serbia
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Scharf A, Pohl F, Egan BM, Kocsisova Z, Kornfeld K. Reproductive Aging in Caenorhabditis elegans: From Molecules to Ecology. Front Cell Dev Biol 2021; 9:718522. [PMID: 34604218 PMCID: PMC8481778 DOI: 10.3389/fcell.2021.718522] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/04/2021] [Indexed: 11/13/2022] Open
Abstract
Aging animals display a broad range of progressive degenerative changes, and one of the most fascinating is the decline of female reproductive function. In the model organism Caenorhabditis elegans, hermaphrodites reach a peak of progeny production on day 2 of adulthood and then display a rapid decline; progeny production typically ends by day 8 of adulthood. Since animals typically survive until day 15 of adulthood, there is a substantial post reproductive lifespan. Here we review the molecular and cellular changes that occur during reproductive aging, including reductions in stem cell number and activity, slowing meiotic progression, diminished Notch signaling, and deterioration of germ line and oocyte morphology. Several interventions have been identified that delay reproductive aging, including mutations, drugs and environmental factors such as temperature. The detailed description of reproductive aging coupled with interventions that delay this process have made C. elegans a leading model system to understand the mechanisms that drive reproductive aging. While reproductive aging has dramatic consequences for individual fertility, it also has consequences for the ecology of the population. Population dynamics are driven by birth and death, and reproductive aging is one important factor that influences birth rate. A variety of theories have been advanced to explain why reproductive aging occurs and how it has been sculpted during evolution. Here we summarize these theories and discuss the utility of C. elegans for testing mechanistic and evolutionary models of reproductive aging.
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Affiliation(s)
- Andrea Scharf
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
| | - Franziska Pohl
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Brian M Egan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
| | - Zuzana Kocsisova
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
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8
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Nguyen VTT, Meyer SC, Rieger H, Endres K. A liquid-culture-based screening approach to study compounds affecting inflammatory processes in Caenorhabditis elegans. Biol Chem 2021; 403:123-129. [PMID: 34535046 DOI: 10.1515/hsz-2021-0262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 09/08/2021] [Indexed: 11/15/2022]
Abstract
Discovery of biomedical drugs makes use of novel biological sources of limited availability and is often in need of fast, small-scale initial screening approaches. Here, we present a screening, based on the reporter Caenorhabditis elegans strain IG692, for identification of anti- and pro-inflammatory properties. The elaborated workflow is based on cultivation in fluid and by this, allows fast and reproducible seeding in 96 well plates. LPS and dexamethasone served as reliable controls, comparable to application in the human cell line THP-1. This in vivo approach offers a first step for selection of e.g. natural products or for repurposing of compounds from drug libraries and by this can serve as a tool in drug discovery for inflammatory human diseases.
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Affiliation(s)
- Vu Thu Thuy Nguyen
- Department of Psychiatry and Psychotherapy, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55131Mainz, Germany
| | - Sarah Christina Meyer
- Department of Psychiatry and Psychotherapy, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55131Mainz, Germany
| | - Hanna Rieger
- Department of Psychiatry and Psychotherapy, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55131Mainz, Germany
| | - Kristina Endres
- Department of Psychiatry and Psychotherapy, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55131Mainz, Germany
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9
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Le TS, Nguyen TTH, Thi Mai Huong B, Nguyen HG, Ha BH, Nguyen VS, Nguyen MH, Nguyen HH, Wang J. Cultivation of Caenorhabditis elegans on new cheap monoxenic media without peptone. J Nematol 2021; 53:e2021-36. [PMID: 33860269 PMCID: PMC8040142 DOI: 10.21307/jofnem-2021-036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Indexed: 01/30/2023] Open
Abstract
The study of species biodiversity within the Caenorhabditis genus of nematodes would be facilitated by the isolation of as many species as possible. So far, over 50 species have been found, usually associated with decaying vegetation or soil samples, with many from Africa, South America and Southeast Asia. Scientists based in these regions can contribute to Caenorhabditis sampling and their proximity would allow intensive sampling, which would be useful for understanding the natural history of these species. However, severely limited research budgets are often a constraint for these local scientists. In this study, we aimed to find a more economical, alternative growth media to rear Caenorhabditis and related species. We tested 25 media permutations using cheaper substitutes for the reagents found in the standard nematode growth media (NGM) and found three media combinations that performed comparably to NGM with respect to the reproduction and longevity of C. elegans. These new media should facilitate the isolation and characterization of Caenorhabditis and other free-living nematodes for the researchers in the poorer regions such as Africa, South America, and Southeast Asia where nematode diversity appears high.
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Affiliation(s)
- Tho Son Le
- College of Forestry Biotechnology, Vietnam National University of Forestry, Hanoi, Vietnam
| | - T. T. Hang Nguyen
- College of Forestry Biotechnology, Vietnam National University of Forestry, Hanoi, Vietnam
| | - Bui Thi Mai Huong
- College of Forestry Biotechnology, Vietnam National University of Forestry, Hanoi, Vietnam
| | - H. Gam Nguyen
- College of Forestry Biotechnology, Vietnam National University of Forestry, Hanoi, Vietnam
| | - B. Hong Ha
- College of Forestry Biotechnology, Vietnam National University of Forestry, Hanoi, Vietnam
| | - Van Sang Nguyen
- Faculty of Biology, VNU University of Science, Vietnam National University, Hanoi, Vietnam
| | - Minh Hung Nguyen
- Center for Molecular Biology, Institute of Research and Development, Duy Tan University, Da Nang, Vietnam
| | - Huy-Hoang Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - John Wang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
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10
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Balakrishnan J, Ganapathi P, Kannan S, Marudhamuthu M, Shanmugam K. Anti-listerial activity of microalgal fatty acid methyl esters and their possible applications as chicken marinade. Int J Food Microbiol 2020; 339:109027. [PMID: 33412385 DOI: 10.1016/j.ijfoodmicro.2020.109027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 11/30/2022]
Abstract
Fatty acid methyl esters (FAMEs) from marine microalgae have been reported to possess antimicrobial activities against several Gram positive and Gram negative bacteria, but a majority of them needs to be explored. The objective of this study was to investigate the antibacterial activity, mechanism of FAMEs from selected marine microalgae against Listeria monocytogenes, and to elucidate its efficacy in food model. The minimum inhibitory concentration of FAMEs was calculated to be 155 μg/mL for Chromulina sp. and 162 μg/mL for Nannochloropsis sp. against L. monocytogenes. Time-killing kinetics showed that FAMEs efficiently inhibited the growth of L. monocytogenes in a time and concentration dependent manner. The mechanism of action of FAMEs was studied by analysing its effects at a MIC on the cellular metabolism, membrane permeability, and membrane integrity of L. monocytogenes. Transmission Electron Microscopy (TEM) results showed that cells exposed to FAMEs showed damaged cell membrane structure with leakage of the internal contents in the cells of L. monocytogenes. Fluorescence microscopy images showed that L. monocytogenes cells treated with FAMEs showed high dead cell population corresponding with propidium iodide positive cells. Furthermore, FAMEs significantly down regulated quorum sensing and biofilm related genes (DegU, FlaE, and FlaD). In vivo therapeutic potential of FAMEs revealed improved Caenorhabditis elegans survival and reduced intestinal colonization during L. monocytogenes infection. Growth of listeria was abolished in chicken meat during the cold storage of 9 days when the samples were pre-treated with FAMEs. These results suggest anti-L. monocytogenes activity of FAMEs and elucidated its use in food control of chicken meat at refrigerated conditions.
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Affiliation(s)
- Jeyakumar Balakrishnan
- Department of Molecular Biology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India
| | - Prakash Ganapathi
- Department of Molecular Biology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India
| | - Suganya Kannan
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India
| | - Murugan Marudhamuthu
- Department of Microbial Technology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625021, Tamil Nadu, India
| | - Kathiresan Shanmugam
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur 610005, Tamil Nadu, India.
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11
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Schifano E, Ficociello G, Vespa S, Ghosh S, Cipollo JF, Talora C, Lotti LV, Mancini P, Uccelletti D. Pmr-1 gene affects susceptibility of Caenorhabditis elegans to Staphylococcus aureus infection through glycosylation and stress response pathways' alterations. Virulence 2019; 10:1013-1025. [PMID: 31771413 PMCID: PMC6930020 DOI: 10.1080/21505594.2019.1697118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Calcium signaling can elicit different pathways involved in an extreme variety of biological processes. Calcium levels must be tightly regulated in a spatial and temporal manner in order to be efficiently and properly utilized in the host physiology. The Ca2+-ATPase, encoded by pmr-1 gene, was first identified in yeast and localized to the Golgi and it appears to be involved in calcium homeostasis. PMR-1 function is evolutionary conserved from yeast to human, where mutations in the orthologous gene ATP2C1 cause Hailey-Hailey disease. In this work, we used the Caenorhabditis elegans model system to gain insight into the downstream response elicited by the loss of pmr-1 gene. We found that pmr-1 knocked down animals not only showed defects in the oligosaccharide structure of glycoproteins at the cell surface but also were characterized by reduced susceptibility to bacterial infection. Although increased resistance to the infection might be related to lack of regular recognition of C. elegans surface glycoproteins by microbial agents, we provide genetic evidence that pmr-1 interfered nematodes mounted a stronger innate immune response to Gram-positive bacterial infection. Thus, our observations indicate pmr-1 as a candidate gene implicated in mediating the worm's innate immune response.
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Affiliation(s)
- Emily Schifano
- Department of Biology and Biotechnology "Charles Darwin", University of Rome, Rome, Italy
| | - Graziella Ficociello
- Department of Biology and Biotechnology "Charles Darwin", University of Rome, Rome, Italy
| | - Simone Vespa
- Department of Experimental Medicine, University of Rome, Rome, Italy
| | - Salil Ghosh
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - John F Cipollo
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Claudio Talora
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | | | - Patrizia Mancini
- Department of Experimental Medicine, University of Rome, Rome, Italy
| | - Daniela Uccelletti
- Department of Biology and Biotechnology "Charles Darwin", University of Rome, Rome, Italy
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12
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Nhan JD, Turner CD, Anderson SM, Yen CA, Dalton HM, Cheesman HK, Ruter DL, Uma Naresh N, Haynes CM, Soukas AA, Pukkila-Worley R, Curran SP. Redirection of SKN-1 abates the negative metabolic outcomes of a perceived pathogen infection. Proc Natl Acad Sci U S A 2019; 116:22322-22330. [PMID: 31611372 PMCID: PMC6825279 DOI: 10.1073/pnas.1909666116] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Early host responses toward pathogens are essential for defense against infection. In Caenorhabditis elegans, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing C. elegans to Pseudomonas aeruginosa similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from pathogen response genes while restoring somatic lipid distribution. In addition, activating p38/MAPK signaling in the absence of pathogens, is sufficient to drive SKN-1-dependent loss of somatic fat. These data define a SKN-1- and p38-dependent axis for coordinating pathogen responses, lipid homeostasis, and survival and identify transcriptional redirection, rather than inactivation, as a mechanism for counteracting the pleiotropic consequences of aberrant transcriptional activity.
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Affiliation(s)
- James D Nhan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
- Department of Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
| | - Christian D Turner
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
- Department of Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
| | - Sarah M Anderson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Chia-An Yen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
- Department of Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
| | - Hans M Dalton
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
- Department of Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
| | - Hilary K Cheesman
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Dana L Ruter
- Biology Department, Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599
| | - Nandhitha Uma Naresh
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Cole M Haynes
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655
| | - Alexander A Soukas
- Center for Human Genetic Research and Diabetes Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114
| | - Read Pukkila-Worley
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655;
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089;
- Department of Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089
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13
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Abstract
Caenorhabditis elegans can serve as a simple genetic host to study interactions between Legionellaceae and their hosts and to examine the contribution of specific gene products to virulence and immunity. C. elegans nematodes have several appealing attributes as a host organism; they are inexpensive, have robust genetic analysis tools, have a simple anatomy yet display a wide range of complex behaviors, and, as invertebrates, do not require animal ethics protocols. Use of C. elegans as a host model complements cell-based models, providing additional support and consistency of the experimental data obtained from multiple models. The C. elegans innate immune system functions similarly to that of the alveolar macrophage including the apoptosis [a.k.a. programmed cell death (PCD)] pathway located within the germline. The digestive tract of C. elegans is a primary interface between the innate immune system and bacterial pathogens. Thus, the C. elegans host model provides an alternative approach to investigate L. pneumophila immunopathogenesis, particularly in the view of the recent discovery of Legionella-containing vacuoles within the gonadal tissues of Legionella-colonized nematodes supporting the plausible evolutionary origin of the strategies employed by L. pneumophila to counteract macrophage cellular responses.
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14
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Anderson A, McMullan R. Neuronal and non-neuronal signals regulate Caernorhabditis elegans avoidance of contaminated food. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0255. [PMID: 29866922 PMCID: PMC6000145 DOI: 10.1098/rstb.2017.0255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2017] [Indexed: 01/24/2023] Open
Abstract
One way in which animals minimize the risk of infection is to reduce their contact with contaminated food. Here, we establish a model of pathogen-contaminated food avoidance using the nematode worm Caernorhabditis elegans. We find that avoidance of pathogen-contaminated food protects C. elegans from the deleterious effects of infection and, using genetic approaches, demonstrate that multiple sensory neurons are required for this avoidance behaviour. In addition, our results reveal that the avoidance of contaminated food requires bacterial adherence to non-neuronal cells in the tail of C. elegans that are also required for the cellular immune response. Previous studies in C. elegans have contributed significantly to our understanding of molecular and cellular basis of host–pathogen interactions and our model provides a unique opportunity to gain basic insights into how animals avoid contaminated food. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours’.
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Affiliation(s)
- Alexandra Anderson
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Rachel McMullan
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, Buckinghamshire MK7 2AA, UK
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15
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Page AP, Roberts M, Félix MA, Pickard D, Page A, Weir W. The golden death bacillus Chryseobacterium nematophagum is a novel matrix digesting pathogen of nematodes. BMC Biol 2019; 17:10. [PMID: 30813925 PMCID: PMC6394051 DOI: 10.1186/s12915-019-0632-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/22/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Nematodes represent important pathogens of humans and farmed animals and cause significant health and economic impacts. The control of nematodes is primarily carried out by applying a limited number of anthelmintic compounds, for which there is now widespread resistance being reported. There is a current unmet need to develop novel control measures including the identification and characterisation of natural pathogens of nematodes. RESULTS Nematode killing bacilli were isolated from a rotten fruit in association with wild free-living nematodes. These bacteria belong to the Chryseobacterium genus (golden bacteria) and represent a new species named Chryseobacterium nematophagum. These bacilli are oxidase-positive, flexirubin-pigmented, gram-negative rods that exhibit gelatinase activity. Caenorhabditis elegans are attracted to and eat these bacteria. Within 3 h of ingestion, however, the bacilli have degraded the anterior pharyngeal chitinous lining and entered the body cavity, ultimately killing the host. Within 24 h, the internal contents of the worms are digested followed by the final digestion of the remaining cuticle over a 2-3-day period. These bacteria will also infect and kill bacterivorous free-living (L1-L3) stages of all tested parasitic nematodes including the important veterinary Trichostrongylids such as Haemonchus contortus and Ostertagia ostertagi. The bacteria exhibit potent collagen-digesting properties, and genome sequencing has identified novel metalloprotease, collagenase and chitinase enzymes representing potential virulence factors. CONCLUSIONS Chryseobacterium nematophagum is a newly discovered pathogen of nematodes that rapidly kills environmental stages of a wide range of key nematode parasites. These bacilli exhibit a unique invasion process, entering the body via the anterior pharynx through the specific degradation of extracellular matrices. This bacterial pathogen represents a prospective biological control agent for important nematode parasites.
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Affiliation(s)
- Antony P Page
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Scotland, UK.
| | - Mark Roberts
- School of Veterinary Medicine, University of Glasgow, Scotland, UK
| | - Marie-Anne Félix
- Institute of Biology of the Ecole Normale Supérieure (IBENS), Paris, France
| | - Derek Pickard
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Andrew Page
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - William Weir
- School of Veterinary Medicine, University of Glasgow, Scotland, UK
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16
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Yang KH, Yun B, Choi HJ, Ryu S, Lee WJ, Oh MH, Song MH, Kim JN, Oh S, Kim Y, Kim YJ. Simple Evaluation of Listeria monocytogenes Pathogenesis Using Caenorhabditis elegans Animal Model. Food Sci Anim Resour 2019; 39:84-92. [PMID: 30882077 PMCID: PMC6411236 DOI: 10.5851/kosfa.2019.e6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 11/06/2022] Open
Abstract
Listeria monocytogenes is a major cause of serious foodborne illness in the dairy foods. Although Caenorhabditis elegans model is well established as a virulence model of pathogenic bacteria, its application on L. monocytogenes is critically unclear. The objective of this study was to carry out an evaluation of L. monocytogenes toxicity using C. elegans nematode as a simple host model. We found that C. elegans nematodes have high susceptibility to L. monocytogenes infection, as a consequence of accumulation of bacteria in the worms' intestine. However, L. innocua, which is known to be non-toxic, is not accumulate in the intestine of worms and is not toxic similarly to Escherichia coli OP50 known as the normal feed source of C. elegans. Importantly, immune-associated genes of C. elegans were intensely upregulated more than 3.0-fold when they exposed to L. monocytogenes. In conclusion, we established that C. elegans is an effective model for studying the toxicity of L. monocytogenes and we anticipate that this system will result in the discovery of many potential anti-listeria agents for dairy foods.
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Affiliation(s)
- Kyoung Hee Yang
- Department of Food and Biotechnology,
Korea University, Sejong 30019,
Korea
| | - Bohyun Yun
- Department of Animal Science and Institute
of Milk Genomics, Chonbuk National University,
Jeonju 54896, Korea
| | - Hye Jin Choi
- Department of Animal Science and Institute
of Milk Genomics, Chonbuk National University,
Jeonju 54896, Korea
| | - Sangdon Ryu
- Department of Animal Science and Institute
of Milk Genomics, Chonbuk National University,
Jeonju 54896, Korea
| | - Woong Ji Lee
- Department of Animal Science and Institute
of Milk Genomics, Chonbuk National University,
Jeonju 54896, Korea
| | - Mi-Hwa Oh
- Animal Products Research and Development
Division, National Institute of Animal Science, Rural Development
Administration, Wanju 55365,
Korea
| | - Min-Ho Song
- Division of Animal and Dairy Science,
Chungnam National University, Daejeon 34134,
Korea
| | - Jong Nam Kim
- Department of Beef Science, Korean
National College of Agriculture and Fisheries,
Jeonju 54874, Korea
| | - Sangnam Oh
- Department of Functional Food and
Biotechnology, Jeonju University, Jeonju 55069,
Korea
| | - Younghoon Kim
- Department of Animal Science and Institute
of Milk Genomics, Chonbuk National University,
Jeonju 54896, Korea
| | - Young Jun Kim
- Department of Food and Biotechnology,
Korea University, Sejong 30019,
Korea
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17
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Geisler F, Coch RA, Richardson C, Goldberg M, Denecke B, Bossinger O, Leube RE. The intestinal intermediate filament network responds to and protects against microbial insults and toxins. Development 2019; 146:dev.169482. [PMID: 30630824 DOI: 10.1242/dev.169482] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022]
Abstract
The enrichment of intermediate filaments in the apical cytoplasm of intestinal cells is evolutionarily conserved, forming a sheath that is anchored to apical junctions and positioned below the microvillar brush border, which suggests a protective intracellular barrier function. To test this, we used Caenorhabditis elegans, the intestinal cells of which are endowed with a particularly dense intermediate filament-rich layer that is referred to as the endotube. We found alterations in endotube structure and intermediate filament expression upon infection with nematicidal B. thuringiensis or treatment with its major pore-forming toxin crystal protein Cry5B. Endotube impairment due to defined genetic mutations of intermediate filaments and their regulators results in increased Cry5B sensitivity as evidenced by elevated larval arrest, prolonged time of larval development and reduced survival. Phenotype severity reflects the extent of endotube alterations and correlates with reduced rescue upon toxin removal. The results provide in vivo evidence for a major protective role of a properly configured intermediate filament network as an intracellular barrier in intestinal cells. This notion is further supported by increased sensitivity of endotube mutants to oxidative and osmotic stress.
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Affiliation(s)
- Florian Geisler
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, 52074 Aachen, Germany
| | - Richard A Coch
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, 52074 Aachen, Germany
| | - Christine Richardson
- School of Biological and Biomedical Sciences, Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Martin Goldberg
- School of Biological and Biomedical Sciences, Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Bernd Denecke
- Genomics Facility, IZKF Aachen, RWTH Aachen University, 52074 Aachen, Germany
| | - Olaf Bossinger
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, 52074 Aachen, Germany
| | - Rudolf E Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, 52074 Aachen, Germany
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18
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Scorzoni L, de Lucas MP, Singulani JDL, de Oliveira HC, Assato PA, Fusco-Almeida AM, Mendes-Giannini MJS. Evaluation of Caenorhabditis elegans as a host model for Paracoccidioides brasiliensis and Paracoccidioides lutzii. Pathog Dis 2018; 76:4816731. [PMID: 29361158 DOI: 10.1093/femspd/fty004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/17/2018] [Indexed: 12/24/2022] Open
Abstract
Paracoccidioidomycosis is a systemic fungal infection affecting mainly Latin American countries that is caused by Paracoccidioides brasiliensis and Paracoccidioides lutzii. During the study of fungal pathogenesis, in vivo studies are crucial to understand the overall mechanisms involving the infection as well as to search for new therapeutic treatments and diagnosis. Caenorhabditis elegans is described as an infection model for different fungi species and a well-characterized organism to study the innate immune response. This study evaluates C. elegans as an infection model for Paracoccidioides spp. It was observed that both species do not cause infection in C. elegans, as occurs with Candida albicans, and one possible explanation is that the irregular size and shape of Paracoccidioides spp. difficult the ingestion of these fungi by the nematode. Besides this difficulty in the infection, we could observe that the simple exposition of C. elegans to Paracoccidioides species was able to trigger a distinct pattern of expression of antimicrobial peptide genes. The expression of cnc-4, nlpl-27 and nlp-31 was superior after the exposure to P. brasiliensis in comparison to P. lutzii (P < 0.05), and these findings demonstrate important differences regarding innate immune response activation caused by the two species of the Paracoccidioides genus.
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Affiliation(s)
- Liliana Scorzoni
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
| | - Maria Pilar de Lucas
- Unidad de Biología Celular, Unidad Funcional de Investigación de Enfermedades Crónicas, Instituto de Salud Carlos III, Majadahonda, Spain
| | - Junya de Lacorte Singulani
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
| | - Haroldo Cesar de Oliveira
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
| | - Patricia Akemi Assato
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
| | - Ana Marisa Fusco-Almeida
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
| | - Maria José Soares Mendes-Giannini
- Laboratório de Micologia Clínica, Departamento de Análises Clínicas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, Brazil
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19
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The Microbial Zoo in the C. elegans Intestine: Bacteria, Fungi and Viruses. Viruses 2018; 10:v10020085. [PMID: 29443938 PMCID: PMC5850392 DOI: 10.3390/v10020085] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 02/08/2018] [Accepted: 02/11/2018] [Indexed: 12/13/2022] Open
Abstract
C. elegans is an invaluable model organism that has been a driving force in many fundamental biological discoveries. However, it is only in the past two decades that it has been applied to host–pathogen interaction studies. These studies have been facilitated by the discoveries of natural microbes that infect C. elegans, including bacteria, fungi and viruses. Notably, many of these microbes share a common site of infection, the C. elegans intestine. Furthermore, the recent descriptions of a natural gut microbiota in C. elegans raise the possibility that this could be a novel model system for microbiome and trans-kingdom interaction studies. Here we review studies of C. elegans host–microbe interactions with a particular focus on the intestine.
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20
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Abstract
Numerous approaches have been taken in the hunt for human disease genes. The identification of such genes not only provides a great deal of information about the mechanism of disease development, but also provides potential avenues for better diagnosis and treatment. In this chapter, we review the use of the nonmammalian model organism C. elegans for the identification of human disease genes. Studies utilizing this relatively simple organism offer a good balance between the ability to recapitulate many aspects of human disease, while still offering an abundance of powerful cell biological, genetic, and genomic tools for disease gene discovery. C. elegans and other nonmammalian models have produced, and will continue to produce, key insights into human disease pathogenesis.
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Affiliation(s)
- Javier Apfeld
- Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Scott Alper
- Department of Biomedical Research, Center for Genes, Environment and Health, National Jewish Health, Denver, CO, 80206, USA.
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
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21
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Schulenburg H, Félix MA. The Natural Biotic Environment of Caenorhabditis elegans. Genetics 2017; 206:55-86. [PMID: 28476862 PMCID: PMC5419493 DOI: 10.1534/genetics.116.195511] [Citation(s) in RCA: 246] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/28/2017] [Indexed: 01/05/2023] Open
Abstract
Organisms evolve in response to their natural environment. Consideration of natural ecological parameters are thus of key importance for our understanding of an organism's biology. Curiously, the natural ecology of the model species Caenorhabditis elegans has long been neglected, even though this nematode has become one of the most intensively studied models in biological research. This lack of interest changed ∼10 yr ago. Since then, an increasing number of studies have focused on the nematode's natural ecology. Yet many unknowns still remain. Here, we provide an overview of the currently available information on the natural environment of C. elegans We focus on the biotic environment, which is usually less predictable and thus can create high selective constraints that are likely to have had a strong impact on C. elegans evolution. This nematode is particularly abundant in microbe-rich environments, especially rotting plant matter such as decomposing fruits and stems. In this environment, it is part of a complex interaction network, which is particularly shaped by a species-rich microbial community. These microbes can be food, part of a beneficial gut microbiome, parasites and pathogens, and possibly competitors. C. elegans is additionally confronted with predators; it interacts with vector organisms that facilitate dispersal to new habitats, and also with competitors for similar food environments, including competitors from congeneric and also the same species. Full appreciation of this nematode's biology warrants further exploration of its natural environment and subsequent integration of this information into the well-established laboratory-based research approaches.
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Affiliation(s)
- Hinrich Schulenburg
- Zoological Institute, Christian-Albrechts Universitaet zu Kiel, 24098 Kiel, Germany
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, École Normale Supérieure, L'université de Recherche Paris Sciences et Lettres, 75005, France
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22
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Abstract
Caenorhabditis elegans is an important model organism with many useful features, including rapid development and aging, easy cultivation, and genetic tractability. Survival assays using C. elegans are powerful methods for studying physiological processes. In this review, we describe diverse types of C. elegans survival assays and discuss the aims, uses, and advantages of specific assays. C. elegans survival assays have played key roles in identifying novel genetic factors that regulate many aspects of animal physiology, such as aging and lifespan, stress response, and immunity against pathogens. Because many genetic factors discovered using C. elegans are evolutionarily conserved, survival assays can provide insights into mechanisms underlying physiological processes in mammals, including humans.
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Affiliation(s)
- Hae-Eun H. Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Yoonji Jung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Seung-Jae V. Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673,
Korea
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23
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Battisti JM, Watson LA, Naung MT, Drobish AM, Voronina E, Minnick MF. Analysis of the Caenorhabditis elegans innate immune response to Coxiella burnetii. Innate Immun 2016; 23:111-127. [PMID: 27884946 DOI: 10.1177/1753425916679255] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The nematode Caenorhabditis elegans is well established as a system for characterization and discovery of molecular mechanisms mediating microbe-specific inducible innate immune responses to human pathogens. Coxiella burnetii is an obligate intracellular bacterium that causes a flu-like syndrome in humans (Q fever), as well as abortions in domesticated livestock, worldwide. Initially, when wild type C. elegans (N2 strain) was exposed to mCherry-expressing C. burnetii (CCB) a number of overt pathological manifestations resulted, including intestinal distension, deformed anal region and a decreased lifespan. However, nematodes fed autoclave-killed CCB did not exhibit these symptoms. Although vertebrates detect C. burnetii via TLRs, pathologies in tol-1(-) mutant nematodes were indistinguishable from N2, and indicate nematodes do not employ this orthologue for detection of C. burnetii. sek-1(-) MAP kinase mutant nematodes succumbed to infection faster, suggesting that this signaling pathway plays a role in immune activation, as previously shown for orthologues in vertebrates during a C. burnetii infection. C. elegans daf-2(-) mutants are hyper-immune and exhibited significantly reduced pathological consequences during challenge. Collectively, these results demonstrate the utility of C. elegans for studying the innate immune response against C. burnetii and could lead to discovery of novel methods for prevention and treatment of disease in humans and livestock.
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Affiliation(s)
- James M Battisti
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Lance A Watson
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Myo T Naung
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Adam M Drobish
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Ekaterina Voronina
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Michael F Minnick
- Program in Cellular, Molecular and Microbial Biology, Division of Biological Sciences, University of Montana, Missoula, MT, USA
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24
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Kuo CJ, Chen JW, Chiu HC, Teng CH, Hsu TI, Lu PJ, Syu WJ, Wang ST, Chou TC, Chen CS. Mutation of the Enterohemorrhagic Escherichia coli Core LPS Biosynthesis Enzyme RfaD Confers Hypersusceptibility to Host Intestinal Innate Immunity In vivo. Front Cell Infect Microbiol 2016; 6:82. [PMID: 27570746 PMCID: PMC4982379 DOI: 10.3389/fcimb.2016.00082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/02/2016] [Indexed: 11/13/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed. Lipopolysaccharides (LPS) are surface glycolipids found on the outer membrane of gram-negative bacteria, including EHEC, and LPS biosynthesis has long been considered as potential anti-bacterial target. Here, we demonstrated that the EHEC rfaD gene that functions in the biosynthesis of the LPS inner core is required for the intestinal colonization and pathogenesis of EHEC in vivo. Disruption of the EHEC rfaD confers attenuated toxicity in Caenorhabditis elegans and less bacterial colonization in the intestine of C. elegans and mouse. Moreover, rfaD is also involved in the control of susceptibility of EHEC to antimicrobial peptides and host intestinal immunity. It is worth noting that rfaD mutation did not interfere with the growth kinetics when compared to the wild-type EHEC cells. Taken together, we demonstrated that mutations of the EHEC rfaD confer hypersusceptibility to host intestinal innate immunity in vivo, and suggested that targeting the RfaD or the core LPS synthesis pathway may provide alternative therapeutic regimens for EHEC infection.
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Affiliation(s)
- Cheng-Ju Kuo
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Jenn-Wei Chen
- Center of Infectious Disease and Signaling Research, National Cheng Kung UniversityTainan, Taiwan
| | - Hao-Chieh Chiu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan UniversityTaipei, Taiwan
| | - Ching-Hao Teng
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Tai-I Hsu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Pei-Jung Lu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Wan-Jr Syu
- Institute of Microbiology and Immunology, National Yang Ming UniversityTaipei, Taiwan
| | - Sin-Tian Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Ting-Chen Chou
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Chang-Shi Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
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25
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Miller EV, Grandi LN, Giannini JA, Robinson JD, Powell JR. The Conserved G-Protein Coupled Receptor FSHR-1 Regulates Protective Host Responses to Infection and Oxidative Stress. PLoS One 2015; 10:e0137403. [PMID: 26360906 PMCID: PMC4567296 DOI: 10.1371/journal.pone.0137403] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 08/17/2015] [Indexed: 01/08/2023] Open
Abstract
The innate immune system’s ability to sense an infection is critical so that it can rapidly respond if pathogenic microorganisms threaten the host, but otherwise maintain a quiescent baseline state to avoid causing damage to the host or to commensal microorganisms. One important mechanism for discriminating between pathogenic and non-pathogenic bacteria is the recognition of cellular damage caused by a pathogen during the course of infection. In Caenorhabditis elegans, the conserved G-protein coupled receptor FSHR-1 is an important constituent of the innate immune response. FSHR-1 activates the expression of antimicrobial infection response genes in infected worms and delays accumulation of the ingested pathogen Pseudomonas aeruginosa. FSHR-1 is central not only to the worm’s survival of infection by multiple pathogens, but also to the worm’s survival of xenobiotic cadmium and oxidative stresses. Infected worms produce reactive oxygen species to fight off the pathogens; FSHR-1 is required at the site of infection for the expression of detoxifying genes that protect the host from collateral damage caused by this defense response. Finally, the FSHR-1 pathway is important for the ability of worms to discriminate pathogenic from benign bacteria and subsequently initiate an aversive learning program that promotes selective pathogen avoidance.
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Affiliation(s)
- Elizabeth V. Miller
- Department of Biology, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Leah N. Grandi
- Department of Biology, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Jennifer A. Giannini
- Department of Biology, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Joseph D. Robinson
- Department of Biology, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Jennifer R. Powell
- Department of Biology, Gettysburg College, Gettysburg, Pennsylvania, United States of America
- * E-mail:
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26
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Disruption of the C. elegans Intestinal Brush Border by the Fungal Lectin CCL2 Phenocopies Dietary Lectin Toxicity in Mammals. PLoS One 2015; 10:e0129381. [PMID: 26057124 PMCID: PMC4461262 DOI: 10.1371/journal.pone.0129381] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 05/07/2015] [Indexed: 12/20/2022] Open
Abstract
Lectins are non-immunoglobulin carbohydrate-binding proteins without enzymatic activity towards the bound carbohydrates. Many lectins of e.g. plants or fungi have been suggested to act as toxins to defend the host against predators and parasites. We have previously shown that the Coprinopsis cinerea lectin 2 (CCL2), which binds to α1,3-fucosylated N-glycan cores, is toxic to Caenorhabditis elegans and results in developmental delay and premature death. In this study, we investigated the underlying toxicity phenotype at the cellular level by electron and confocal microscopy. We found that CCL2 directly binds to the intestinal apical surface and leads to a highly damaged brush border with loss of microvilli, actin filament depolymerization, and invaginations of the intestinal apical plasma membrane through gaps in the terminal web. We excluded several possible toxicity mechanisms such as internalization and pore-formation, suggesting that CCL2 acts directly on intestinal apical plasma membrane or glycocalyx proteins. A genetic screen for C. elegans mutants resistant to CCL2 generated over a dozen new alleles in bre 1, ger 1, and fut 1, three genes required for the synthesis of the sugar moiety recognized by CCL2. CCL2-induced intestinal brush border defects in C. elegans are similar to the damage observed previously in rats after feeding the dietary lectins wheat germ agglutinin or concanavalin A. The evolutionary conserved reaction of the brush border between mammals and nematodes might allow C. elegans to be exploited as model organism for the study of dietary lectin-induced intestinal pathology in mammals.
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27
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Abstract
A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues.
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Affiliation(s)
- Ann K Corsi
- Biology Department, The Catholic University of America, Washington, DC 20064
| | - Bruce Wightman
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, New York 10027
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López Hernández Y, Yero D, Pinos-Rodríguez JM, Gibert I. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens. Front Microbiol 2015; 6:38. [PMID: 25699030 PMCID: PMC4316775 DOI: 10.3389/fmicb.2015.00038] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/12/2015] [Indexed: 01/15/2023] Open
Abstract
Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions.
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Affiliation(s)
- Yamilé López Hernández
- Centro de Biociencias, Universidad Autónoma de San Luis Potosí San Luis de Potosí, Mexico
| | - Daniel Yero
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona Barcelona, Spain ; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Juan M Pinos-Rodríguez
- Centro de Biociencias, Universidad Autónoma de San Luis Potosí San Luis de Potosí, Mexico
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona Barcelona, Spain ; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Barcelona, Spain
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Sivamaruthi BS, Prasanth MI, Balamurugan K. Alterations in Caenorhabditis elegans and Cronobacter sakazakii lipopolysaccharide during interaction. Arch Microbiol 2014; 197:327-37. [PMID: 25416126 DOI: 10.1007/s00203-014-1064-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 11/08/2014] [Accepted: 11/12/2014] [Indexed: 11/26/2022]
Abstract
Lipopolysaccharide is one of the pathogen-associated molecular patterns of Gram-negative bacteria which are essential for its pathogenicity. Cronobacter sakazakii is an opportunistic, emergent pathogen, which infects and cause mortality in Caenorhabditis elegans. In this study, modifications in host and C. sakazakii LPS during infections were evaluated. The physiological assays revealed that LPS alone is sufficient to affect the host pharyngeal pumping rate, brood size and cause lethality. FTIR spectra of LPS revealed that C. sakazakii modifies its LPS to escape from the recognition of host immune system. These results indicate that LPS plays a key role in C. sakazakii pathogenicity. qPCR studies revealed that LPS modulated the expression of selected host immune (clec-60, clec-87, lys-7, ilys-3, F08G5.6, atf-7, scl-2, cpr-2) and aging-related genes (skn-1, clk-2, bra-2, age-1, bec-1, daf-16, daf-2). Moreover, it was confirmed that p38 MAPK pathway has a major role in host immune response against LPS-mediated challenges.
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Head B, Aballay A. Recovery from an acute infection in C. elegans requires the GATA transcription factor ELT-2. PLoS Genet 2014; 10:e1004609. [PMID: 25340560 PMCID: PMC4207467 DOI: 10.1371/journal.pgen.1004609] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 07/17/2014] [Indexed: 11/18/2022] Open
Abstract
The mechanisms involved in the recognition of microbial pathogens and activation of the immune system have been extensively studied. However, the mechanisms involved in the recovery phase of an infection are incompletely characterized at both the cellular and physiological levels. Here, we establish a Caenorhabditis elegans-Salmonella enterica model of acute infection and antibiotic treatment for studying biological changes during the resolution phase of an infection. Using whole genome expression profiles of acutely infected animals, we found that genes that are markers of innate immunity are down-regulated upon recovery, while genes involved in xenobiotic detoxification, redox regulation, and cellular homeostasis are up-regulated. In silico analyses demonstrated that genes altered during recovery from infection were transcriptionally regulated by conserved transcription factors, including GATA/ELT-2, FOXO/DAF-16, and Nrf/SKN-1. Finally, we found that recovery from an acute bacterial infection is dependent on ELT-2 activity.
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Affiliation(s)
- Brian Head
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alejandro Aballay
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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George DT, Behm CA, Hall DH, Mathesius U, Rug M, Nguyen KCQ, Verma NK. Shigella flexneri infection in Caenorhabditis elegans: cytopathological examination and identification of host responses. PLoS One 2014; 9:e106085. [PMID: 25187942 PMCID: PMC4154869 DOI: 10.1371/journal.pone.0106085] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 07/30/2014] [Indexed: 01/08/2023] Open
Abstract
The Gram-negative bacterium Shigella flexneri is the causative agent of shigellosis, a diarrhoeal disease also known as bacillary dysentery. S. flexneri infects the colonic and rectal epithelia of its primate host and induces a cascade of inflammatory responses that culminates in the destruction of the host intestinal lining. Molecular characterization of host-pathogen interactions in this infection has been challenging due to the host specificity of S. flexneri strains, as it strictly infects humans and non-human primates. Recent studies have shown that S. flexneri infects the soil dwelling nematode Caenorhabditis elegans, however, the interactions between S. flexneri and C. elegans at the cellular level and the cause of nematode death are unknown. Here we attempt to gain insight into the complex host-pathogen interactions between S. flexneri and C. elegans. Using transmission electron microscopy, we show that live S. flexneri cells accumulate in the nematode intestinal lumen, produce outer membrane vesicles and invade nematode intestinal cells. Using two-dimensional differential in-gel electrophoresis we identified host proteins that are differentially expressed in response to S. flexneri infection. Four of the identified genes, aco-1, cct-2, daf-19 and hsp-60, were knocked down using RNAi and ACO-1, CCT-2 and DAF-19, which were identified as up-regulated in response to S. flexneri infection, were found to be involved in the infection process. aco-1 RNAi worms were more resistant to S. flexneri infection, suggesting S. flexneri-mediated disruption of host iron homeostasis. cct-2 and daf-19 RNAi worms were more susceptible to infection, suggesting that these genes are induced as a protective mechanism by C. elegans. These observations further our understanding of the processes involved in S. flexneri infection of C. elegans, which is immensely beneficial to the routine use of this new in vivo model to study S. flexneri pathogenesis.
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Affiliation(s)
- Divya T. George
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
| | - Carolyn A. Behm
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
| | - David H. Hall
- Center for C. elegans Anatomy, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Ulrike Mathesius
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra, Australia
| | - Melanie Rug
- Centre for Advanced Microscopy, The Australian National University, Canberra, Australia
| | - Ken C. Q. Nguyen
- Center for C. elegans Anatomy, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Naresh K. Verma
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
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Jiménez-Hidalgo M, Kurz CL, Pedrajas JR, Naranjo-Galindo FJ, González-Barrios M, Cabello J, Sáez AG, Lozano E, Button EL, Veal EA, Fierro-González JC, Swoboda P, Miranda-Vizuete A. Functional characterization of thioredoxin 3 (TRX-3), a Caenorhabditis elegans intestine-specific thioredoxin. Free Radic Biol Med 2014; 68:205-19. [PMID: 24316195 PMCID: PMC4018987 DOI: 10.1016/j.freeradbiomed.2013.11.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 11/13/2013] [Accepted: 11/22/2013] [Indexed: 01/15/2023]
Abstract
Thioredoxins are a class of evolutionarily conserved proteins that have been demonstrated to play a key role in many cellular processes involving redox reactions. We report here the genetic and biochemical characterization of Caenorhabditis elegans TRX-3, the first metazoan thioredoxin with an intestine-specific expression pattern. By using green fluorescent protein reporters we have found that TRX-3 is expressed in both the cytoplasm and the nucleus of intestinal cells, with a prominent localization at the apical membrane. Although intestinal function, reproductive capacity, longevity, and resistance of trx-3 loss-of-function mutants to many stresses are indistinguishable from those of wild-type animals, we have observed a slight reduction in size and a minor reduction in the defecation cycle timing of trx-3 mutants. Interestingly, trx-3 is induced upon infection by Photorhabdus luminescens and Candida albicans, and TRX-3 overexpression provides a modest protection against these pathogens. Together, our data indicate that TRX-3 function in the intestine is dispensable for C. elegans development but may be important to fight specific bacterial and fungal infections.
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Affiliation(s)
- María Jiménez-Hidalgo
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Cyril Léopold Kurz
- Centre d'Immunologie de Marseille-Luminy, UM2 Aix-Marseille Université, Case 906, 13288 Marseille cedex 9, France
| | - José Rafael Pedrajas
- Grupo de Bioquímica y Señalización Celular, Departamento de Biología Experimental, Universidad de Jaén, 23071 Jaén, Spain
| | - Francisco José Naranjo-Galindo
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - María González-Barrios
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Juan Cabello
- Center for Biomedical Research of La Rioja, 26006 Logroño, Spain
| | - Alberto G Sáez
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Encarnación Lozano
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Emma L Button
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Elizabeth A Veal
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Juan Carlos Fierro-González
- Center for Biosciences at Novum, Department of Biosciences and Nutrition, Karolinska Institute, S-14183 Huddinge, Sweden
| | - Peter Swoboda
- Center for Biosciences at Novum, Department of Biosciences and Nutrition, Karolinska Institute, S-14183 Huddinge, Sweden
| | - Antonio Miranda-Vizuete
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain; Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain.
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Thomas R, Hamat RA, Neela V. Stenotrophomonas maltophilia: pathogenesis model using Caenorhabditis elegans. J Med Microbiol 2013; 62:1777-1779. [PMID: 23988629 DOI: 10.1099/jmm.0.063230-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Renjan Thomas
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
| | - Rukman Awang Hamat
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
| | - Vasanthakumari Neela
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
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Host-Microbe Interactions in Caenorhabditis elegans. ISRN MICROBIOLOGY 2013; 2013:356451. [PMID: 23984180 PMCID: PMC3747393 DOI: 10.1155/2013/356451] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/16/2013] [Indexed: 01/09/2023]
Abstract
A good understanding of how microbes interact with hosts has a direct bearing on our capability of fighting infectious microbial pathogens and making good use of beneficial ones. Among the model organisms used to study reciprocal actions among microbes and hosts, C. elegans may be the most advantageous in the context of its unique attributes such as the short life cycle, easiness of laboratory maintenance, and the availability of different genetic mutants. This review summarizes the recent advances in understanding host-microbe interactions in C. elegans. Although these investigations have greatly enhanced our understanding of C. elegans-microbe relationships, all but one of them involve only one or few microbial species. We argue here that more research is needed for exploring the evolution and establishment of a complex microbial community in the worm's intestine and its interaction with the host.
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Chen HY, Maklakov AA. The worm that lived: Evolution of rapid aging under high extrinsic mortality revisited. WORM 2013; 2:e23704. [PMID: 24778930 PMCID: PMC3875642 DOI: 10.4161/worm.23704] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 01/17/2013] [Indexed: 12/18/2022]
Abstract
Organisms age because of the "selection shadow"-the decline of the force of natural selection with age. Seemingly straightforward corollary of this theory is the Medawar-Williams prediction, which maintains that increased extrinsic (non-aging) mortality will result in the evolution of accelerated aging and decreased longevity. Despite its centrality to modern thinking about the ultimate causes of aging, this prediction ignores the fact that mortality is often a non-random process depending on individual condition. Increased condition-dependent mortality inescapably results in increased selection for resistance against the agent of mortality. Provided that resistance to various stressors is commonly associated with increased longevity, the evolutionary outcome is no longer certain. We recently documented this experimentally by showing that populations of Caenorhabditis remanei evolved to live shorter under high extrinsic mortality, but only when mortality was applied haphazardly. On the contrary, when extrinsic mortality was caused by heat-shock, populations experiencing the same rate of increased mortality evolved greater longevities, notwithstanding increased "selection shadow." Intriguingly, stress-resistant and long-lived worms were also more fecund. We discuss these results in the light of recent theoretical developments, such as condition-environment interactions and hyperfunction theory of aging.
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Affiliation(s)
- Hwei-yen Chen
- Ageing Research Group; Department of Animal Ecology; Evolutionary Biology Centre; Uppsala University; Uppsala, Sweden
| | - Alexei A Maklakov
- Ageing Research Group; Department of Animal Ecology; Evolutionary Biology Centre; Uppsala University; Uppsala, Sweden
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Evaluating the pathogenic potential of environmental Escherichia coli by using the Caenorhabditis elegans infection model. Appl Environ Microbiol 2013; 79:2435-45. [PMID: 23377948 DOI: 10.1128/aem.03501-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The detection and abundance of Escherichia coli in water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborne E. coli isolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148 E. coli environmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated with Caenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic to C. elegans than those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genes sfaD, focA, and focG, which encode adhesins; of iroN2, which encodes a siderophore receptor; of pic, which encodes an autotransporter protein; and of b1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall, E. coli isolates predicted to be pathogenic on the basis of genotyping were indeed so in the C. elegans infection assay. Furthermore, the detection of C. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection.
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Physiological control of germline development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 757:101-31. [PMID: 22872476 DOI: 10.1007/978-1-4614-4015-4_5] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The intersection between developmental programs and environmental conditions that alter physiology is a growing area of research interest. The C. elegans germ line is emerging as a particularly sensitive and powerful model for these studies. The germ line is subject to environmentally regulated diapause points that allow worms to withstand harsh conditions both prior to and after reproduction commences. It also responds to more subtle changes in physiological conditions. Recent studies demonstrate that different aspects of germ line development are sensitive to environmental and physiological changes and that conserved signaling pathways such as the AMPK, Insulin/IGF, TGFβ, and TOR-S6K, and nuclear hormone receptor pathways mediate this sensitivity. Some of these pathways genetically interact with but appear distinct from previously characterized mechanisms of germline cell fate control such as Notch signaling. Here, we review several aspects of hermaphrodite germline development in the context of "feasting," "food-limited," and "fasting" conditions. We also consider connections between lifespan, metabolism and the germ line, and we comment on special considerations for examining germline development under altered environmental and physiological conditions. Finally, we summarize the major outstanding questions in the field.
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Abstract
Caenorhabditis elegans can serve as a simple genetic host to study interactions between Legionellaceae and their hosts, and to examine the contribution of specific gene products to virulence and immunity. C. elegans nematodes have several appealing attributes as a host organism; they are inexpensive, have robust genetic analysis tools, have a simple anatomy yet display a wide range of complex behaviors, and, as invertebrates, do not require animal ethics protocols. Use of C. elegans as a host model complements cell-based models, providing additional support and consistency of the experimental data obtained from multiple models. The C. elegans innate immune system functions similarly to that of the alveolar macrophage including the apoptosis [e.g. programmed cell death (PCD)] pathway located within the germline. The digestive tract of C. elegans is a primary interface between the innate immune system and bacterial pathogens. Thus, the C. elegans host model provides an alternative approach to investigate Legionella pneumophila immunopathogenesis.
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Gomez F, Monsalve GC, Tse V, Saiki R, Weng E, Lee L, Srinivasan C, Frand AR, Clarke CF. Delayed accumulation of intestinal coliform bacteria enhances life span and stress resistance in Caenorhabditis elegans fed respiratory deficient E. coli. BMC Microbiol 2012; 12:300. [PMID: 23256533 PMCID: PMC3548685 DOI: 10.1186/1471-2180-12-300] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 12/14/2012] [Indexed: 11/24/2022] Open
Abstract
Background Studies with the nematode model Caenorhabditis elegans have identified conserved biochemical pathways that act to modulate life span. Life span can also be influenced by the composition of the intestinal microbiome, and C. elegans life span can be dramatically influenced by its diet of Escherichia coli. Although C. elegans is typically fed the standard OP50 strain of E. coli, nematodes fed E. coli strains rendered respiratory deficient, either due to a lack coenzyme Q or the absence of ATP synthase, show significant life span extension. Here we explore the mechanisms accounting for the enhanced nematode life span in response to these diets. Results The intestinal load of E. coli was monitored by determination of worm-associated colony forming units (cfu/worm or coliform counts) as a function of age. The presence of GFP-expressing E. coli in the worm intestine was also monitored by fluorescence microscopy. Worms fed the standard OP50 E. coli strain have high cfu and GFP-labeled bacteria in their guts at the L4 larval stage, and show saturated coliform counts by day five of adulthood. In contrast, nematodes fed diets of respiratory deficient E. coli lacking coenzyme Q lived significantly longer and failed to accumulate bacteria within the lumen at early ages. Animals fed bacteria deficient in complex V showed intermediate coliform numbers and were not quite as long-lived. The results indicate that respiratory deficient Q-less E. coli are effectively degraded in the early adult worm, either at the pharynx or within the intestine, and do not accumulate in the intestinal tract until day ten of adulthood. Conclusions The findings of this study suggest that the nematodes fed the respiratory deficient E. coli diet live longer because the delay in bacterial colonization of the gut subjects the worms to less stress compared to worms fed the OP50 E. coli diet. This work suggests that bacterial respiration can act as a virulence factor, influencing the ability of bacteria to colonize and subsequently harm the animal host. Respiratory deficient bacteria may pose a useful model for probing probiotic relationships within the gut microbiome in higher organisms.
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Affiliation(s)
- Fernando Gomez
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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Guha S, Klees M, Wang X, Li J, Dong Y, Cao M. Influence of planktonic and sessile Listeria monocytogenes on Caenorhabditis elegans. Arch Microbiol 2012; 195:19-26. [PMID: 22961596 DOI: 10.1007/s00203-012-0841-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 08/13/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
Listeria monocytogenes is the etiologic agent of listeriosis, a food-borne disease affecting humans and a variety of animals. In order to combat this pathogen, it is crucial to have an understanding of its natural interplay with the environment. For this reason, the free soil nematode Caenorhabditis elegans was focused upon because of its shared natural habitat with Listeria and its potential as a model organism for Listeria pathogenesis. Previous studies have generated some contradictory results on Listeria's ability to kill C. elegans, making additional interaction studies such as this more attractive. In our study, we carried out a series of killing assays in a systematic manner using different Listeria strains under different growth conditions. In addition to studying the effects of planktonic cells, we examined the interaction between C. elegans and sessile listerial cells. Our findings suggest that, rather than causing infection and death, L. monocytogenes may extend the life span of C. elegans. This indicates that Listeria is not pathogenic to C. elegans. We also found that C. elegans can feed and ingest sessile cells, as well as carry the pathogen in its gut, implying that C. elegans could be a vehicle for L. monocytogenes spread in the environment.
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Affiliation(s)
- Sujay Guha
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
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The saposin-like protein SPP-12 is an antimicrobial polypeptide in the pharyngeal neurons of Caenorhabditis elegans and participates in defence against a natural bacterial pathogen. Biochem J 2012; 445:205-12. [PMID: 22519640 DOI: 10.1042/bj20112102] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Caenopores are antimicrobial and pore-forming polypeptides in Caenorhabditis elegans belonging to the saposin-like protein superfamily and are considered important elements of the nematode's intestinal immune system. In the present study, we demonstrate that, unlike the other members of the multifarious gene family (spps) coding for caenopores, spp-12 is expressed exclusively in two pharyngeal neurons. Recombinantly expressed SPP-12 binds to phospholipid membranes and forms pores in a pH-dependent manner characteristic of caenopores. Moreover, SPP-12 kills viable Gram-positive bacteria, yeast cells and amoebae by permeabilizing their membranes, suggesting a wide-target cell spectrum. A spp-12 knockout mutant is more susceptible to pathogenic Bacillus thuringiensis than wild-type worms and is tolerant to non-pathogenic bacteria. By contrast, SPP-1, a caenopore, whose gene is expressed only in the intestine and reported to be regulated by the same pathway as spp-12, is apparently non-protective against pathogenic B. thuringiensis, although it also does display antimicrobial activity. The transcription of spp-1 is down-regulated in wild-type worms in the presence of pathogenic B. thuringiensis and a spp-1 knockout mutant is hyposusceptible to this bacterium. This implies that SPP-12, but not SPP-1, contributes to resistance against B. thuringiensis, a natural pathogen of the nematode.
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Abstract
Caenorhabditis elegans is a preeminent model organism, but the natural ecology of this nematode has been elusive. A four-year survey of French orchards published in BMC Biology reveals thriving populations of C. elegans (and Caenorhabditis briggsae) in rotting fruit and plant stems. Rather than being simply a 'soil nematode', C. elegans appears to be a 'plant-rot nematode'. These studies signal a growing interest in the integrated genomics and ecology of these tractable animals.
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Affiliation(s)
- Mark Blaxter
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Dee R Denver
- Department of Zoology, Center for Genome Research and Biocomputing, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
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Ezziane Z. Analysis of the Hox epigenetic code. World J Clin Oncol 2012; 3:48-56. [PMID: 22553504 PMCID: PMC3341740 DOI: 10.5306/wjco.v3.i4.48] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 11/21/2011] [Accepted: 04/01/2012] [Indexed: 02/06/2023] Open
Abstract
Archetypes of histone modifications associated with diverse chromosomal states that regulate access to DNA are leading the hypothesis of the histone code (or epigenetic code). However, it is still not evident how these post-translational modifications of histone tails lead to changes in chromatin structure. Histone modifications are able to activate and/or inactivate several genes and can be transmitted to next generation cells due to an epigenetic memory. The challenging issue is to identify or “decrypt” the code used to transmit these modifications to descent cells. Here, an attempt is made to describe how histone modifications operate as part of histone code that stipulates patterns of gene expression. This papers emphasizes particularly on the correlation between histone modifications and patterns of Hox gene expression in Caenorhabditis elegans. This work serves as an example to illustrate the power of the epigenetic machinery and its use in drug design and discovery.
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Affiliation(s)
- Zoheir Ezziane
- Zoheir Ezziane, Welcome Trust Centre For Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, United Kingdom
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Portal-Celhay C, Bradley ER, Blaser MJ. Control of intestinal bacterial proliferation in regulation of lifespan in Caenorhabditis elegans. BMC Microbiol 2012; 12:49. [PMID: 22452899 PMCID: PMC3342110 DOI: 10.1186/1471-2180-12-49] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 03/27/2012] [Indexed: 01/16/2023] Open
Abstract
Background A powerful approach to understanding complex processes such as aging is to use model organisms amenable to genetic manipulation, and to seek relevant phenotypes to measure. Caenorhabditis elegans is particularly suited to studies of aging, since numerous single-gene mutations have been identified that affect its lifespan; it possesses an innate immune system employing evolutionarily conserved signaling pathways affecting longevity. As worms age, bacteria accumulate in the intestinal tract. However, quantitative relationships between worm genotype, lifespan, and intestinal lumen bacterial load have not been examined. We hypothesized that gut immunity is less efficient in older animals, leading to enhanced bacterial accumulation, reducing longevity. To address this question, we evaluated the ability of worms to control bacterial accumulation as a functional marker of intestinal immunity. Results We show that as adult worms age, several C. elegans genotypes show diminished capacity to control intestinal bacterial accumulation. We provide evidence that intestinal bacterial load, regulated by gut immunity, is an important causative factor of lifespan determination; the effects are specified by bacterial strain, worm genotype, and biologic age, all acting in concert. Conclusions In total, these studies focus attention on the worm intestine as a locus that influences longevity in the presence of an accumulating bacterial population. Further studies defining the interplay between bacterial species and host immunity in C. elegans may provide insights into the general mechanisms of aging and age-related diseases.
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Affiliation(s)
- Cynthia Portal-Celhay
- Department of Medicine, New York University School of Medicine, NYU Langone Medical Center, 550 First Avenue, OBV A606, New York, NY 10016, USA.
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Portal-Celhay C, Blaser MJ. Competition and resilience between founder and introduced bacteria in the Caenorhabditis elegans gut. Infect Immun 2012; 80:1288-99. [PMID: 22184417 PMCID: PMC3294642 DOI: 10.1128/iai.05522-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 12/05/2011] [Indexed: 12/21/2022] Open
Abstract
The microbial communities that reside within the intestinal tract in vertebrates are complex and dynamic. In this report, we establish the utility of Caenorhabditis elegans as a model system for identifying the factors that contribute to bacterial persistence and for host control of gut luminal populations. We found that for N2 worms grown on mixed lawns of bacteria, Salmonella enterica serovar Typhimurium substantially outcompeted Escherichia coli, even when E. coli was initially present at 100-fold-higher concentrations. To address whether innate immunity affects the competition, the daf-2 and daf-16 mutants were studied; their total gut bacterial levels reflect overall capacity for colonization, but Salmonella outcompeted E. coli to an extent similar to wild-type worms. To address the role of virulence properties, Salmonella Δspi-1 Δspi-2 was used to compete with E. coli. The net differential was significantly less than that for wild-type Salmonella; thus, spi-1 spi-2 encodes C. elegans colonization factors. An E. coli strain with repeated in vivo passage had an enhanced ability to compete against an in vitro-passed E. coli strain and against Salmonella. Our data provide evidence of active competition for colonization niches in the C. elegans gut, as determined by bacterial factors and subject to in vivo selection.
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Affiliation(s)
- Cynthia Portal-Celhay
- Department of Medicine and Microbiology, New York University School of Medicine, New York, New York, USA
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Duclairoir Poc C, Groboillot A, Lesouhaitier O, Morin JP, Orange N, Feuilloley MJ. Caenorhabditis elegans: a model to monitor bacterial air quality. BMC Res Notes 2011; 4:503. [PMID: 22099854 PMCID: PMC3279514 DOI: 10.1186/1756-0500-4-503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 11/18/2011] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards to chemicals and particles contrary to micro-organisms. Indeed, pertinent and reliable tests to evaluate this biohazard are scarce. In this work, our purpose was to evaluate the Caenorhaditis elegans killing test, a model considered as an equivalent to the mouse acute toxicity test in pharmaceutical industry, in order to monitor air bacterial quality. FINDINGS The present study investigates the bacterial population in dust clouds generated during crop ship loading in harbor installations (Rouen harbor, Normandy, France). With a biocollector, airborne bacteria were impacted onto the surface of agar medium. After incubation, a replicate of the colonies on a fresh agar medium was done using a velvet. All the replicated colonies were pooled creating the "Total Air Sample". Meanwhile, all the colonies on the original plate were isolated. Among which, five representative bacterial strains were chosen. The virulence of these representatives was compared to that of the "Total Air Sample" using the Caenorhaditis elegans killing test. The survival kinetic of nematodes fed with the "Total Air Sample" is consistent with the kinetics obtained using the five different representatives strains. CONCLUSIONS Bacterial air quality can now be monitored in a one shot test using the Caenorhaditis elegans killing test.
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Affiliation(s)
- Cécile Duclairoir Poc
- Laboratory of Microbiology-Signals and MicroEnvironment, Normandy University, University of Rouen, EA 4312, 55 rue Saint Germain, 27000 Evreux, France.
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Alper S. Model systems to the rescue: The relationship between aging and innate immunity. Commun Integr Biol 2011; 3:409-14. [PMID: 21057627 DOI: 10.4161/cib.3.5.12561] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 06/03/2010] [Indexed: 12/27/2022] Open
Abstract
In humans, there is an interdependent relationship between aging and immune system function, with each process affecting the outcome of the other. Aging can trigger immune system dysfunction, and alterations in the immune response can in turn affect human lifespan. Genetic experiments in model organisms such as C. elegans and Drosophila have led to the identification of numerous genes and signaling pathways that can modulate organismal lifespan and immune system function. Importantly, many of these signaling pathways exhibit conserved function in multiple species, including mammals, suggesting that the research in these simpler models could one day pave the way for the modulation of aging and immunity in humans. Here, we review the recent progress in our understanding of aging, innate immunity and the interaction between these two processes using these simple model systems. Additionally, we discuss what this may tell us about aging and the innate immune system in humans.
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Affiliation(s)
- Scott Alper
- Integrated Department of Immunology; Center for Genes, environment and Health; National Jewish Health; Denver, CO USA
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Lin J, Hackam DJ. Worms, flies and four-legged friends: the applicability of biological models to the understanding of intestinal inflammatory diseases. Dis Model Mech 2011; 4:447-56. [PMID: 21669933 PMCID: PMC3124049 DOI: 10.1242/dmm.007252] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Diseases of intestinal inflammation, including Crohn's disease, ulcerative colitis and necrotizing enterocolitis, cause substantial acute and chronic disability in a large proportion of the population. Crohn's disease and ulcerative colitis, which are collectively referred to as inflammatory bowel disease (IBD), lead to recurrent episodes of intestinal dysfunction and systemic illness, whereas necrotizing enterocolitis is characterized by the development of dramatic and all too often fatal intestinal necrosis in infants. To determine the molecular underpinnings of these disorders, investigators have explored a variety of animal models that vary widely in their complexity. These experimental systems include the invertebrate nematode Caenorhabditis elegans, the more complex invertebrate Drosophila melanogaster, and vertebrate systems including mice, rats and other mammals. This review explores the experimental models that are used to mimic and evaluate the pathogenic mechanisms leading to these diseases of intestinal inflammation. We then highlight, as an example, how the use of different experimental models that focus on the role of Toll-like receptor 4 (TLR4) signaling in the gut has revealed important distinctions between the pathogenesis of IBD and necrotizing enterocolitis. Specifically, TLR4-mediated signaling plays a protective role in the development of Crohn's disease and ulcerative colitis, whereas this signaling pathway plays a causative role in the development of necrotizing enterocolitis in the newborn small intestine by adversely affecting intestinal injury and repair mechanisms.
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Affiliation(s)
- Joyce Lin
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, Pittsburgh, PA 15213, USA
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Ewbank JJ, Zugasti O. C. elegans: model host and tool for antimicrobial drug discovery. Dis Model Mech 2011; 4:300-4. [PMID: 21504910 PMCID: PMC3097103 DOI: 10.1242/dmm.006684] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For almost four decades, the nematode Caenorhabditis elegans has been of great value in many fields of biological research. It is now used extensively in studies of microbial pathogenesis and innate immunity. The worm lacks an adaptive immune system and relies solely on its innate immune defences to cope with pathogen attack. Infectious microbes, many of which are of clinical interest, trigger specific mechanisms of innate immunity, and provoke the expression of antifungal or antibacterial polypeptides. In this review, we highlight some of these families of antimicrobial peptides (AMPs) and proteins that are candidates for the development of novel antibiotics. In addition, we describe how systems of C. elegans infection provide an increasing number of possibilities for large-scale in vivo screens for the discovery of new antimicrobial drugs. These systems open promising perspectives for innovative human therapies.
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Affiliation(s)
- Jonathan J Ewbank
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Case 906, 13288 Marseille cedex 9, France.
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Szeto SSW, Reinke SN, Lemire BD. (1)H NMR-based metabolic profiling reveals inherent biological variation in yeast and nematode model systems. JOURNAL OF BIOMOLECULAR NMR 2011; 49:245-254. [PMID: 21350846 DOI: 10.1007/s10858-011-9492-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 02/01/2011] [Indexed: 05/30/2023]
Abstract
The application of metabolomics to human and animal model systems is poised to provide great insight into our understanding of disease etiology and the metabolic changes that are associated with these conditions. However, metabolomic studies have also revealed that there is significant, inherent biological variation in human samples and even in samples from animal model systems where the animals are housed under carefully controlled conditions. This inherent biological variability is an important consideration for all metabolomics analyses. In this study, we examined the biological variation in (1)H NMR-based metabolic profiling of two model systems, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Using relative standard deviations (RSD) as a measure of variability, our results reveal that both model systems have significant amounts of biological variation. The C. elegans metabolome possesses greater metabolic variance with average RSD values of 29 and 39%, depending on the food source that was used. The S. cerevisiae exometabolome RSD values ranged from 8% to 12% for the four strains examined. We also determined whether biological variation occurs between pairs of phenotypically identical yeast strains. Multivariate statistical analysis allowed us to discriminate between pair members based on their metabolic phenotypes. Our results highlight the variability of the metabolome that exists even for less complex model systems cultured under defined conditions. We also highlight the efficacy of metabolic profiling for defining these subtle metabolic alterations.
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Affiliation(s)
- Samuel S W Szeto
- Department of Biochemistry, School of Molecular and Systems Medicine, University of Alberta, Edmonton, AB, T6G 2H7, Canada
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