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Salcedo-Tacuma D, Asad N, Howells G, Anderson R, Smith DM. Proteasome hyperactivation rewires the proteome enhancing stress resistance, proteostasis, lipid metabolism and ERAD in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588128. [PMID: 38617285 PMCID: PMC11014606 DOI: 10.1101/2024.04.04.588128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Proteasome dysfunction is implicated in the pathogenesis of neurodegenerative diseases and age-related proteinopathies. Using a C. elegans model, we demonstrate that 20S proteasome hyperactivation, facilitated by 20S gate-opening, accelerates the targeting of intrinsically disordered proteins. This leads to increased protein synthesis, extensive rewiring of the proteome and transcriptome, enhanced oxidative stress defense, accelerated lipid metabolism, and peroxisome proliferation. It also promotes ER-associated degradation (ERAD) of aggregation-prone proteins, such as alpha-1 antitrypsin (ATZ) and various lipoproteins. Notably, our results reveal that 20S proteasome hyperactivation suggests a novel role in ERAD with broad implications for proteostasis-related disorders, simultaneously affecting lipid homeostasis and peroxisome proliferation. Furthermore, the enhanced cellular capacity to mitigate proteostasis challenges, alongside unanticipated acceleration of lipid metabolism is expected to contribute to the longevity phenotype of this mutant. Remarkably, the mechanism of longevity induced by 20S gate opening appears unique, independent of known longevity and stress-resistance pathways. These results support the therapeutic potential of 20S proteasome activation in mitigating proteostasis-related disorders broadly and provide new insights into the complex interplay between proteasome activity, cellular health, and aging.
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Affiliation(s)
- David Salcedo-Tacuma
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Nadeeem. Asad
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Giovanni Howells
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Raymond Anderson
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - David M. Smith
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
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Ding AJ, Zhang WM, Tao J, Chen B, Liu XC, Dong Y, Ma HJ, Pan SD, He JB, Zeng WK. Salmonella enterica serovar Paratyphi A-induced immune response in Caenorhabditis elegans depends on MAPK pathways and DAF-16. Front Immunol 2023; 14:1118003. [PMID: 37122724 PMCID: PMC10132459 DOI: 10.3389/fimmu.2023.1118003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/27/2023] [Indexed: 05/02/2023] Open
Abstract
Salmonella enterica serovar Paratyphi A (S. Paratyphi A) is a pathogen that can cause enteric fever. According to the recent epidemic trends of typhoid fever, S. Paratyphi A has been the major important causative factor in paratyphoid fever. An effective vaccine for S. Paratyphi A has not been developed, which made it a tricky public health concern. Until now, how S. Paratyphi A interacts with organisms remain unknown. Here using lifespan assay, we found that S. Paratyphi A could infect Caenorhabditis elegans (C. elegans) at 25°C, and attenuate thermotolerance. The immune response of C. elegans was mediated by tir-1, nsy-1, sek-1, pmk-1, mpk-1, skn-1, daf-2 and daf-16, suggesting that S. Paratyphi A could regulate the MAPK and insulin pathways. Furthermore, we observed several phenotypical changes when C. elegans were fed S. Paratyphi A, including an accelerated decline in body movement, reduced the reproductive capacity, shortened spawning cycle, strong preference for OP50, arrested pharyngeal pumping and colonization of the intestinal lumen. The virulence of S. Paratyphi A requires living bacteria and is not mediated by secreting toxin. Using hydrogen peroxide analysis and quantitative RT-PCR, we discovered that S. Paratyphi A could increase oxidative stress and regulate the immune response in C. elegans. Our results sheds light on the infection mechanisms of S. Paratyphi A and lays a foundation for drugs and vaccine development.
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Planococcus maritimu ML1206 Strain Enhances Stress Resistance and Extends the Lifespan in Caenorhabditis elegans via FOXO/DAF-16. Mar Drugs 2022; 21:md21010001. [PMID: 36662174 PMCID: PMC9866299 DOI: 10.3390/md21010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/30/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
The antioxidant effect of probiotics has been widely recognized across the world, which is of great significance in food, medicine, and aquaculture. There are abundant marine microbial resources in the ocean, which provide a new space for humans to explore new probiotics. Previously, we reported on the anti-infective effects of Planococcus maritimu ML1206, a potential marine probiotic. The antioxidant activity of ML1206 in C. elegans was studied in this paper. The study showed that ML1206 could improve the ability of nematodes to resist oxidative stress and effectively prolong their lifespan. The results confirmed that ML1206 could significantly increase the activities of CAT and GSH-PX, and reduce the accumulation of reactive oxygen species (ROS) in nematodes under oxidative stress conditions. In addition, ML1206 promoted DAF-16 transfer to the nucleus and upregulated the expression of sod-3, hsp-16.2, and ctl-2, which are downstream antioxidant-related genes of DAF-16. Furthermore, the expression of the SOD-3::GFP and HSP-16.2::GFP was significantly higher in the transgenic strains fed with ML1206 than that in the control group fed with OP50, with or without stress. In summary, these findings suggest that ML1206 is a novel marine probiotic with an antioxidant function that stimulates nematodes to improve their defense abilities against oxidative stress and prolong the lifespan by regulating the translocation of FOXO/DAF-16. Therefore, ML1206 may be explored as a potential dietary supplement in aquaculture and for anti-aging and antioxidant purposes.
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Servello FA, Fernandes R, Eder M, Harris N, Martin OMF, Oswal N, Lindberg A, Derosiers N, Sengupta P, Stroustrup N, Apfeld J. Neuronal temperature perception induces specific defenses that enable C. elegans to cope with the enhanced reactivity of hydrogen peroxide at high temperature. eLife 2022; 11:e78941. [PMID: 36226814 PMCID: PMC9635881 DOI: 10.7554/elife.78941] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/12/2022] [Indexed: 11/30/2022] Open
Abstract
Hydrogen peroxide is the most common reactive chemical that organisms face on the microbial battlefield. The rate with which hydrogen peroxide damages biomolecules required for life increases with temperature, yet little is known about how organisms cope with this temperature-dependent threat. Here, we show that Caenorhabditis elegans nematodes use temperature information perceived by sensory neurons to cope with the temperature-dependent threat of hydrogen peroxide produced by the pathogenic bacterium Enterococcus faecium. These nematodes preemptively induce the expression of specific hydrogen peroxide defenses in response to perception of high temperature by a pair of sensory neurons. These neurons communicate temperature information to target tissues expressing those defenses via an insulin/IGF1 hormone. This is the first example of a multicellular organism inducing their defenses to a chemical when they sense an inherent enhancer of the reactivity of that chemical.
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Affiliation(s)
| | - Rute Fernandes
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Matthias Eder
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Nathan Harris
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Olivier MF Martin
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Natasha Oswal
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Anders Lindberg
- Biology Department, Northeastern UniversityBostonUnited States
| | | | - Piali Sengupta
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Nicholas Stroustrup
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Javier Apfeld
- Biology Department, Northeastern UniversityBostonUnited States
- Bioengineering Department, Northeastern UniversityBostonUnited States
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Ghazisaeedi F, Meens J, Hansche B, Maurischat S, Schwerk P, Goethe R, Wieler LH, Fulde M, Tedin K. A virulence factor as a therapeutic: the probiotic Enterococcus faecium SF68 arginine deiminase inhibits innate immune signaling pathways. Gut Microbes 2022; 14:2106105. [PMID: 35921516 PMCID: PMC9351580 DOI: 10.1080/19490976.2022.2106105] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The probiotic bacterial strain Enterococcus faecium SF68 has been shown to alleviate symptoms of intestinal inflammation in human clinical trials and animal feed supplementation studies. To identify factors involved in immunomodulatory effects on host cells, E. faecium SF68 and other commensal and clinical Enterococcus isolates were screened using intestinal epithelial cell lines harboring reporter fusions for NF-κB and JNK(AP-1) activation to determine the responses of host cell innate immune signaling pathways when challenged with bacterial protein and cell components. Cell-free, whole-cell lysates of E. faecium SF68 showed a reversible, inhibitory effect on both NF-κB and JNK(AP-1) signaling pathway activation in intestinal epithelial cells and abrogated the response to bacterial and other Toll-like receptor (TLR) ligands. The inhibitory effect was species-specific, and was not observed for E. avium, E. gallinarum, or E. casseliflavus. Screening of protein fractions of E. faecium SF68 lysates yielded an active fraction containing a prominent protein identified as arginine deiminase (ADI). The E. faecium SF68 arcA gene encoding arginine deiminase was cloned and introduced into E. avium where it conferred the same NF-κB inhibitory effects on intestinal epithelial cells as seen for E. faecium SF68. Our results indicate that the arginine deiminase of E. faecium SF68 is responsible for inhibition of host cell NF-κB and JNK(AP-1) pathway activation, and is likely to be responsible for the anti-inflammatory and immunomodulatory effects observed in prior clinical human and animal trials. The implications for the use of this probiotic strain for preventive and therapeutic purposes are discussed.
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Affiliation(s)
- Fereshteh Ghazisaeedi
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Jochen Meens
- Institute for Microbiology, University of Veterinary Medicine, Hannover, Germany
| | - Bianca Hansche
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,Sanofi-AventisGmbH, Berlin, Germany
| | - Sven Maurischat
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Peter Schwerk
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Ralph Goethe
- Institute for Microbiology, University of Veterinary Medicine, Hannover, Germany
| | - Lothar H. Wieler
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,Robert Koch Institute, Berlin, Germany
| | - Marcus Fulde
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Karsten Tedin
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,CONTACT Karsten Tedin Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Robert-von-Ostertag-Strasse7, Berlin14163Germany
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6
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Schiffer JA, Stumbur SV, Seyedolmohadesin M, Xu Y, Serkin WT, McGowan NG, Banjo O, Torkashvand M, Lin A, Hosea CN, Assié A, Samuel BS, O’Donnell MP, Venkatachalam V, Apfeld J. Modulation of sensory perception by hydrogen peroxide enables Caenorhabditis elegans to find a niche that provides both food and protection from hydrogen peroxide. PLoS Pathog 2021; 17:e1010112. [PMID: 34941962 PMCID: PMC8699984 DOI: 10.1371/journal.ppat.1010112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/14/2021] [Indexed: 02/07/2023] Open
Abstract
Hydrogen peroxide (H2O2) is the most common chemical threat that organisms face. Here, we show that H2O2 alters the bacterial food preference of Caenorhabditis elegans, enabling the nematodes to find a safe environment with food. H2O2 induces the nematodes to leave food patches of laboratory and microbiome bacteria when those bacterial communities have insufficient H2O2-degrading capacity. The nematode's behavior is directed by H2O2-sensing neurons that promote escape from H2O2 and by bacteria-sensing neurons that promote attraction to bacteria. However, the input for H2O2-sensing neurons is removed by bacterial H2O2-degrading enzymes and the bacteria-sensing neurons' perception of bacteria is prevented by H2O2. The resulting cross-attenuation provides a general mechanism that ensures the nematode's behavior is faithful to the lethal threat of hydrogen peroxide, increasing the nematode's chances of finding a niche that provides both food and protection from hydrogen peroxide.
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Affiliation(s)
- Jodie A. Schiffer
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Stephanie V. Stumbur
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Maedeh Seyedolmohadesin
- Physics Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Yuyan Xu
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - William T. Serkin
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Natalie G. McGowan
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Oluwatosin Banjo
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Mahdi Torkashvand
- Physics Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Albert Lin
- Department of Physics, Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Ciara N. Hosea
- Alkek Center for Metagenomics and Microbiome Research and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Adrien Assié
- Alkek Center for Metagenomics and Microbiome Research and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Buck S. Samuel
- Alkek Center for Metagenomics and Microbiome Research and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Michael P. O’Donnell
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Vivek Venkatachalam
- Physics Department, Northeastern University, Boston, Massachusetts, United States of America
| | - Javier Apfeld
- Biology Department, Northeastern University, Boston, Massachusetts, United States of America
- Bioengineering Department, Northeastern University, Boston, Massachusetts, United States of America
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7
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Jia Q, Sieburth D. Mitochondrial hydrogen peroxide positively regulates neuropeptide secretion during diet-induced activation of the oxidative stress response. Nat Commun 2021; 12:2304. [PMID: 33863916 PMCID: PMC8052458 DOI: 10.1038/s41467-021-22561-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/17/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondria play a pivotal role in the generation of signals coupling metabolism with neurotransmitter release, but a role for mitochondrial-produced ROS in regulating neurosecretion has not been described. Here we show that endogenously produced hydrogen peroxide originating from axonal mitochondria (mtH2O2) functions as a signaling cue to selectively regulate the secretion of a FMRFamide-related neuropeptide (FLP-1) from a pair of interneurons (AIY) in C. elegans. We show that pharmacological or genetic manipulations that increase mtH2O2 levels lead to increased FLP-1 secretion that is dependent upon ROS dismutation, mitochondrial calcium influx, and cysteine sulfenylation of the calcium-independent PKC family member PKC-1. mtH2O2-induced FLP-1 secretion activates the oxidative stress response transcription factor SKN-1/Nrf2 in distal tissues and protects animals from ROS-mediated toxicity. mtH2O2 levels in AIY neurons, FLP-1 secretion and SKN-1 activity are rapidly and reversibly regulated by exposing animals to different bacterial food sources. These results reveal a previously unreported role for mtH2O2 in linking diet-induced changes in mitochondrial homeostasis with neuropeptide secretion.
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Affiliation(s)
- Qi Jia
- PIBBS program, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Derek Sieburth
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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8
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Goswamy D, Irazoqui JE. A unifying hypothesis on the central role of reactive oxygen species in bacterial pathogenesis and host defense in C. elegans. Curr Opin Immunol 2020; 68:9-20. [PMID: 32898751 DOI: 10.1016/j.coi.2020.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 01/06/2023]
Abstract
During intestinal infection, microbes induce ROS by various mechanisms in C. elegans. ROS can have beneficial roles, acting as antimicrobials and as signaling molecules that activate cytoprotective pathways. Failure to maintain appropriate levels of ROS causes oxidative stress and cellular damage. This review uses the Damage Response Framework to interpret several recent observations on the relationships between infection, host response, and host damage, with a focus on mechanisms mediated by ROS. We propose a unifying hypothesis that ROS drive a collapse in proteostasis in infected C. elegans, which results in death during unresolved infection. Because the signaling pathways highlighted here are conserved in mammals, the mentioned and future studies can provide new tools of hypothesis generation in human health and disease.
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Affiliation(s)
- Debanjan Goswamy
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, United States; Immunology and Microbiology Program, University of Massachusetts Medical School, Worcester, MA 01605, United States
| | - Javier E Irazoqui
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605, United States; Immunology and Microbiology Program, University of Massachusetts Medical School, Worcester, MA 01605, United States.
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9
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Ahamefule CS, Qin Q, Odiba AS, Li S, Moneke AN, Ogbonna JC, Jin C, Wang B, Fang W. Caenorhabditis elegans-Based Aspergillus fumigatus Infection Model for Evaluating Pathogenicity and Drug Efficacy. Front Cell Infect Microbiol 2020; 10:320. [PMID: 32670897 PMCID: PMC7332887 DOI: 10.3389/fcimb.2020.00320] [Citation(s) in RCA: 12] [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: 03/26/2020] [Accepted: 05/26/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is the most reported causative pathogen associated with the increasing global incidences of aspergilloses, with the health of immunocompromised individuals mostly at risk. Monitoring the pathogenicity of A. fumigatus strains to identify virulence factors and evaluating the efficacy of potent active agents against this fungus in animal models are indispensable in current research effort. Caenorhabditis elegans has been successfully utilized as an infection model for bacterial and dimorphic fungal pathogens because of the advantages of being time-efficient, and less costly. However, application of this model to the filamentous fungus A. fumigatus is less investigated. In this study, we developed and optimized a stable and reliable C. elegans model for A. fumigatus infection, and demonstrated the infection process with a fluorescent strain. Virulence results of several mutant strains in our nematode model demonstrated high consistency with the already reported pathogenicity pattern in other models. Furthermore, this C. elegans-A. fumigatus infection model was optimized for evaluating the efficacy of current antifungal drugs. Interestingly, the azole drugs in nematode model prevented conidial germination to a higher extent than amphotericin B. Overall, our established C. elegans infection model for A. fumigatus has potential applications in pathogenicity evaluation, antifungal agents screening, drug efficacy evaluation as well as host-pathogen interaction studies.
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Affiliation(s)
- Chukwuemeka Samson Ahamefule
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Qijian Qin
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Arome Solomon Odiba
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
| | - Siqiao Li
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Anene N. Moneke
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - James C. Ogbonna
- Department of Microbiology, University of Nigeria, Nsukka, Nigeria
| | - Cheng Jin
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bin Wang
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
| | - Wenxia Fang
- National Engineering Research Center for Non-food Biorefinery, Guangxi Academy of Sciences, Nanning, China
- State Key Laboratory of Non-food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, China
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10
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Schiffer JA, Servello FA, Heath WR, Amrit FRG, Stumbur SV, Eder M, Martin OMF, Johnsen SB, Stanley JA, Tam H, Brennan SJ, McGowan NG, Vogelaar AL, Xu Y, Serkin WT, Ghazi A, Stroustrup N, Apfeld J. Caenorhabditis elegans processes sensory information to choose between freeloading and self-defense strategies. eLife 2020; 9:e56186. [PMID: 32367802 PMCID: PMC7213980 DOI: 10.7554/elife.56186] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022] Open
Abstract
Hydrogen peroxide is the preeminent chemical weapon that organisms use for combat. Individual cells rely on conserved defenses to prevent and repair peroxide-induced damage, but whether similar defenses might be coordinated across cells in animals remains poorly understood. Here, we identify a neuronal circuit in the nematode Caenorhabditis elegans that processes information perceived by two sensory neurons to control the induction of hydrogen peroxide defenses in the organism. We found that catalases produced by Escherichia coli, the nematode's food source, can deplete hydrogen peroxide from the local environment and thereby protect the nematodes. In the presence of E. coli, the nematode's neurons signal via TGFβ-insulin/IGF1 relay to target tissues to repress expression of catalases and other hydrogen peroxide defenses. This adaptive strategy is the first example of a multicellular organism modulating its defenses when it expects to freeload from the protection provided by molecularly orthologous defenses from another species.
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Affiliation(s)
| | | | - William R Heath
- Biology Department, Northeastern UniversityBostonUnited States
| | | | | | - Matthias Eder
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Olivier MF Martin
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Sean B Johnsen
- Biology Department, Northeastern UniversityBostonUnited States
| | | | - Hannah Tam
- Biology Department, Northeastern UniversityBostonUnited States
| | - Sarah J Brennan
- Biology Department, Northeastern UniversityBostonUnited States
| | | | | | - Yuyan Xu
- Biology Department, Northeastern UniversityBostonUnited States
| | | | - Arjumand Ghazi
- Department of Pediatrics, University of Pittsburgh School of MedicinePittsburghUnited States
- Departments of Developmental Biology and Cell Biology and Physiology, University of Pittsburgh School of MedicinePittsburghUnited States
| | - Nicholas Stroustrup
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Javier Apfeld
- Biology Department, Northeastern UniversityBostonUnited States
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11
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Differential effects of Th17 cytokines during the response of neutrophils to Burkholderia cenocepacia outer membrane protein A. Cent Eur J Immunol 2020; 44:403-413. [PMID: 32140053 PMCID: PMC7050059 DOI: 10.5114/ceji.2019.92800] [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: 05/17/2017] [Accepted: 08/28/2017] [Indexed: 12/11/2022] Open
Abstract
T helper 17 cells are involved in the immunopathology of cystic fibrosis. They play a key role in recruitment of neutrophils, which is the first line of defence against bacteria. Additionally, Burkholderia cenocepacia outer membrane protein A (OmpA) BCAL2958 is considered a potential protective epitope for vaccine development. The present study aimed to investigate the neutrophil response to OmpA in the presence of Th17 cytokines, IL-17 and IL-22 at different times of activation. Neutrophils were isolated from whole blood of healthy volunteers and activated with OmpA in the presence of IL-17, IL-22 or both cytokines together. Supernatant was collected after 1 h, 2 h, 4 h, 8 h, and 12 h. Neutrophil activation was assessed by measuring MPO, TNF-α, elastase, hydrogen peroxide, catalase and NO. The results revealed that the combination of IL-17 and IL-22 cytokines induced the release of NE, catalase, H2O2 and TNF-α from neutrophils activated with Burkholderia OmpA at late stages of activation. However, IL-22 alone or IL-17 alone decreased the myeloperoxidase (MPO), catalase and NE levels at early stages of neutrophil activation. The presence of IL-17 alone led to a significant increase in TNF-α level after 1 h and 12 h. However, the presence of IL-22 alone led to a significant increase in TNF-α level after only 1 h but a significant decrease after 8 h of activation was observed as compared to OmpA stimulated neutrophils. In conclusion, Th17 cytokines IL-17 and IL-22, have differential effects during the neutrophil response to Burkholderia OmpA.
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Abstract
![]()
Protein
footprinting coupled with mass spectrometry is being increasingly
used for the study of protein interactions and conformations. The
hydroxyl radical footprinting method, fast photochemical oxidation
of proteins (FPOP), utilizes hydroxyl radicals to oxidatively modify
solvent accessible amino acids. Here, we describe the further development
of FPOP for protein structural analysis in vivo (IV-FPOP) with Caenorhabditis elegans. C. elegans, part
of the nematode family, are used as model systems for many human diseases.
The ability to perform structural studies in these worms would provide
insight into the role of structure in disease pathogenesis. Many parameters
were optimized for labeling within the worms including the microfluidic
flow system and hydrogen peroxide concentration. IV-FPOP was able
to modify several hundred proteins in various organs within the worms.
The method successfully probed solvent accessibility similarily to
in vitro FPOP, demonstrating its potential for use as a structural
technique in a multiorgan system. The coupling of the method with
mass spectrometry allows for amino-acid-residue-level structural information,
a higher resolution than currently available in vivo methods.
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Affiliation(s)
- Jessica A Espino
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
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Chan JP, Wright JR, Wong HT, Ardasheva A, Brumbaugh J, McLimans C, Lamendella R. Using Bacterial Transcriptomics to Investigate Targets of Host-Bacterial Interactions in Caenorhabditis elegans. Sci Rep 2019; 9:5545. [PMID: 30944351 PMCID: PMC6447554 DOI: 10.1038/s41598-019-41452-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 03/07/2019] [Indexed: 01/01/2023] Open
Abstract
The interactions between a host and its resident microbes form complicated networks that can affect host physiology. Disentangling these host-microbe interactions can help us better understand mechanisms by which bacteria affect hosts, while also defining the integral commensal protection that host-associated microbiota offer to promote health. Here we utilize a tractable genetic model organism, Caenorhabditis elegans, to study the effects of host environments on bacterial gene expression and metabolic pathways. First, we compared the transcriptomic profiles of E. coli OP50 in vitro (on agar plates) versus in vivo (fed to C. elegans host). Our data revealed that 110 biosynthetic genes were enriched in host-associated E. coli. Several of these expressed genes code for the precursors and products needed for the synthesis of lipopolysaccharides (LPS), which are important for innate immune and stress responses, as well as pathogenicity. Secondly, we compared the transcriptomic profiles of E. coli fed to hosts with different genetic backgrounds, including the long-lived daf-2/insulin like growth factor (IGF) receptor and short lived daf-16/FOXO transcription factor mutants. We find that hosts genetics also alters bacterial metabolic pathways. Given that bacteria influence host health, this transcriptomics approach can elucidate genes mediating host aging.
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Affiliation(s)
- Jason P Chan
- Department of Biology, Juniata College, Huntingdon, PA, USA.
| | | | - Hoi Tong Wong
- Department of Biology, Juniata College, Huntingdon, PA, USA
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Della Noce B, Carvalho Uhl MVD, Machado J, Waltero CF, de Abreu LA, da Silva RM, da Fonseca RN, de Barros CM, Sabadin G, Konnai S, da Silva Vaz I, Ohashi K, Logullo C. Carbohydrate Metabolic Compensation Coupled to High Tolerance to Oxidative Stress in Ticks. Sci Rep 2019; 9:4753. [PMID: 30894596 PMCID: PMC6427048 DOI: 10.1038/s41598-019-41036-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/26/2019] [Indexed: 01/01/2023] Open
Abstract
Reactive oxygen species (ROS) are natural byproducts of metabolism that have toxic effects well documented in mammals. In hematophagous arthropods, however, these processes are not largely understood. Here, we describe that Rhipicephalus microplus ticks and embryonic cell line (BME26) employ an adaptive metabolic compensation mechanism that confers tolerance to hydrogen peroxide (H2O2) at concentrations too high for others organisms. Tick survival and reproduction are not affected by H2O2 exposure, while BME26 cells morphology was only mildly altered by the treatment. Furthermore, H2O2-tolerant BME26 cells maintained their proliferative capacity unchanged. We evaluated several genes involved in gluconeogenesis, glycolysis, and pentose phosphate pathway, major pathways for carbohydrate catabolism and anabolism, describing a metabolic mechanism that explains such tolerance. Genetic and catalytic control of the genes and enzymes associated with these pathways are modulated by glucose uptake and energy resource availability. Transient increase in ROS levels, oxygen consumption, and ROS-scavenger enzymes, as well as decreased mitochondrial superoxide levels, were indicative of cell adaptation to high H2O2 exposure, and suggested a tolerance strategy developed by BME26 cells to cope with oxidative stress. Moreover, NADPH levels increased upon H2O2 challenge, and this phenomenon was sustained mainly by G6PDH activity. Interestingly, G6PDH knockdown in BME26 cells did not impair H2O2 tolerance, but generated an increase in NADP-ICDH transcription. In agreement with the hypothesis of a compensatory NADPH production in these cells, NADP-ICDH knockdown increased G6PDH relative transcript level. The present study unveils the first metabolic evidence of an adaptive mechanism to cope with high H2O2 exposure and maintain redox balance in ticks.
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Affiliation(s)
- Bárbara Della Noce
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Marcelle Vianna de Carvalho Uhl
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Josias Machado
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Camila Fernanda Waltero
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Leonardo Araujo de Abreu
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Renato Martins da Silva
- Laboratory of Infectious Diseases, Hokkaido University, Sapporo, 060-0818, Japan
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Rodrigo Nunes da Fonseca
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Cintia Monteiro de Barros
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil
| | - Gabriela Sabadin
- Centro de Biotecnologia and Faculdade de Veterinária - UFRGS, Porto Alegre, RS, Brazil
| | - Satoru Konnai
- Laboratory of Infectious Diseases, Hokkaido University, Sapporo, 060-0818, Japan
| | | | - Kazuhiko Ohashi
- Laboratory of Infectious Diseases, Hokkaido University, Sapporo, 060-0818, Japan
| | - Carlos Logullo
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Morfologia, NUPEM-UFRJ, Macaé, RJ, Brazil.
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil.
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In vitro and in vivo biofilm inhibitory efficacy of geraniol-cefotaxime combination against Staphylococcus spp. Food Chem Toxicol 2019; 125:322-332. [DOI: 10.1016/j.fct.2019.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 12/12/2022]
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16
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Rhizobium induces DNA damage in Caenorhabditis elegans intestinal cells. Proc Natl Acad Sci U S A 2019; 116:3784-3792. [PMID: 30808764 DOI: 10.1073/pnas.1815656116] [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] [Indexed: 12/24/2022] Open
Abstract
In their natural habitat of rotting fruit, the nematode Caenorhabditis elegans feeds on the complex bacterial communities that thrive in this rich growth medium. Hundreds of diverse bacterial strains cultured from such rotting fruit allow C. elegans growth and reproduction when tested individually. In screens for C. elegans responses to single bacterial strains associated with nematodes in fruit, we found that Rhizobium causes a genome instability phenotype; we observed abnormally long or fragmented intestinal nuclei due to aberrant nuclear division, or defective karyokinesis. The karyokinesis defects were restricted to intestinal cells and required close proximity between bacteria and the worm. A genetic screen for C. elegans mutations that cause the same intestinal karyokinesis defect followed by genome sequencing of the isolated mutant strains identified mutations that disrupt DNA damage repair pathways, suggesting that Rhizobium may cause DNA damage in C. elegans intestinal cells. We hypothesized that such DNA damage is caused by reactive oxygen species produced by Rhizobium and found that hydrogen peroxide added to benign Escherichia coli can cause the same intestinal karyokinesis defects in WT C. elegans Supporting this model, free radical scavengers suppressed the Rhizobium-induced C. elegans DNA damage. Thus, Rhizobium may signal to eukaryotic hosts via reactive oxygen species, and the host may respond with DNA damage repair pathways.
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Khan F, Jain S, Oloketuyi SF. Bacteria and bacterial products: Foe and friends to Caenorhabditis elegans. Microbiol Res 2018; 215:102-113. [DOI: 10.1016/j.micres.2018.06.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/11/2018] [Accepted: 06/24/2018] [Indexed: 02/07/2023]
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The activation of the oxidative stress response transcription factor SKN-1 in Caenorhabditis elegans by mitis group streptococci. PLoS One 2018; 13:e0202233. [PMID: 30114261 PMCID: PMC6095534 DOI: 10.1371/journal.pone.0202233] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/30/2018] [Indexed: 01/20/2023] Open
Abstract
The mitis group, a member of the genetically diverse viridans group streptococci, predominately colonizes the human oropharynx. This group has been shown to cause a wide range of infectious complications in humans, including bacteremia in patients with neutropenia, orbital cellulitis and infective endocarditis. Hydrogen peroxide (H2O2) has been identified as a virulence factor produced by this group of streptococci. More importantly, it has been shown that Streptococcus oralis and S. mitis induce epithelial cell and macrophage death via the production of H2O2. Previously, H2O2 mediated killing was observed in the nematode Caenorhabditis elegans in response to S. oralis and S. mitis. The genetically tractable model organism C. elegans is an excellent system to study mechanisms of pathogenicity and stress responses. Using this model, we observed rapid H2O2 mediated killing of the worms by S. gordonii in addition to S. mitis and S. oralis. Furthermore, we observed colonization of the intestine of the worms when exposed to S. gordonii suggesting the involvement of an infection-like process. In response to the H2O2 produced by the mitis group, we demonstrate the oxidative stress response is activated in the worms. The oxidative stress response transcription factor SKN-1 is required for the survival of the worms and provides protection against H2O2 produced by S. gordonii. We show during infection, H2O2 is required for the activation of SKN-1 and is mediated via the p38-MAPK pathway. The activation of the p38 signaling pathway in the presence of S. gordonii is not mediated by the endoplasmic reticulum (ER) transmembrane protein kinase IRE-1. However, IRE-1 is required for the survival of worms in response to S. gordonii. These finding suggests a parallel pathway senses H2O2 produced by the mitis group and activates the phosphorylation of p38. Additionally, the unfolded protein response plays an important role during infection.
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Kamaladevi A, Balamurugan K. Global Proteomics Revealed Klebsiella pneumoniae Induced Autophagy and Oxidative Stress in Caenorhabditis elegans by Inhibiting PI3K/AKT/mTOR Pathway during Infection. Front Cell Infect Microbiol 2017; 7:393. [PMID: 28932706 PMCID: PMC5592217 DOI: 10.3389/fcimb.2017.00393] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/22/2017] [Indexed: 01/29/2023] Open
Abstract
The enterobacterium, Klebsiella pneumoniae invades the intestinal epithelium of humans by interfering with multiple host cell response. To uncover a system-level overview of host response during infection, we analyzed the global dynamics of protein profiling in Caenorhabditis elegans using quantitative proteomics approach. Comparison of protein samples of nematodes exposed to K. pneumoniae for 12, 24, and 36 h by 2DE revealed several changes in host proteome. A total of 266 host-encoded proteins were identified by 2DE MALDI-MS/MS and LC-MS/MS and the interacting partners of the identified proteins were predicted by STRING 10.0 analysis. In order to understand the interacting partners of regulatory proteins with similar or close pI ranges, a liquid IEF was performed and the isolated fractions containing proteins were identified by LC-MS/MS. Functional bioinformatics analysis on identified proteins deciphered that they were mostly related to the metabolism, dauer formation, apoptosis, endocytosis, signal transduction, translation, developmental, and reproduction process. Gene enrichment analysis suggested that the metabolic process as the most overrepresented pathway regulated against K. pneumoniae infection. The dauer-like formation in infected C. elegans along with intestinal atrophy and ROS during the physiological analysis indicated that the regulation of metabolic pathway is probably through the involvement of mTOR. Immunoblot analysis supported the above notion that the K. pneumoniae infection induced protein mis-folding in host by involving PI3Kinase/AKT-1/mTOR mediated pathway. Furthermore, the susceptibility of pdi-2, akt-1, and mTOR C. elegans mutants confirmed the role and involvement of PI3K/AKT/mTOR pathway in mediating protein mis-folding which appear to be translating the vulnerability of host defense toward K. pneumoniae infection.
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Viszwapriya D, Subramenium GA, Prithika U, Balamurugan K, Pandian SK. Betulin inhibits virulence and biofilm ofStreptococcus pyogenesby suppressingropBcore regulon,sagAanddltA. Pathog Dis 2016; 74:ftw088. [DOI: 10.1093/femspd/ftw088] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2016] [Indexed: 12/21/2022] Open
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Galbadage T, Shepherd TF, Cirillo SLG, Gumienny TL, Cirillo JD. The Caenorhabditis elegans p38 MAPK Gene plays a key role in protection from mycobacteria. Microbiologyopen 2016; 5:436-52. [PMID: 26919641 PMCID: PMC4905996 DOI: 10.1002/mbo3.341] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/13/2016] [Accepted: 01/19/2016] [Indexed: 12/17/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) are critical mediators of cellular responses to pathogens and are activated in response to infection, but investigation is difficult in multi-cell hosts due to developmental lethality of mutations. Mycobacterium marinum (Mm) is an established model for tuberculosis, a disease afflicting nearly one-third of the world's population. We found that Mm-infected Caenorhabditis elegans display >80% mortality, but nonpathogenic M. smegmatis cause <15% mortality. C. elegans display pathological changes when infected with Mm, whereas Mm mutants produce lower mortality, suggesting that C. elegans is a promising virulence model for detailed genetic analysis. C. elegans MAPK mutants are hypersusceptible to mycobacterial infection; however, the C. elegans TOL-like, TGF-β and insulin-like pathway genes do not play important roles in susceptibility. We show that pathogenic mycobacteria inhibit MAPK-mediated protection through the MAPK phosphatase gene and demonstrate that C. elegans provide a genetically tractable pathogenicity model of both the host and pathogen.
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Affiliation(s)
- Thushara Galbadage
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Tonya F Shepherd
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Suat L G Cirillo
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
| | - Tina L Gumienny
- Department of Biology, Texas Woman's University, Denton, Texas, 76204-5799
| | - Jeffrey D Cirillo
- Departments of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas, 77807-3260
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Sivasankar C, Maruthupandiyan S, Balamurugan K, James PB, Krishnan V, Pandian SK. A combination of ellagic acid and tetracycline inhibits biofilm formation and the associated virulence of Propionibacterium acnes in vitro and in vivo. BIOFOULING 2016; 32:397-410. [PMID: 26930280 DOI: 10.1080/08927014.2016.1148141] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Propionibacterium acnes is an opportunistic pathogen which has become notorious owing to its ability to form a recalcitrant biofilm and to develop drug resistance. The current study aimed to develop anti-biofilm treatments against clinical isolates of P. acnes under in vitro and in vivo conditions. A combination of ellagic acid and tetracycline (ETC; 250 μg ml(-1) + 0.312 μg ml(-1)) was determined to effectively inhibit biofilm formation by P. acnes (80-91%) without affecting its growth, therefore potentially limiting the possibility of the bacterium attaining resistance. In addition, ETC reduced the production of extracellular polymeric substances (EPS) (20-26%), thereby making P. acnes more susceptible to the human immune system and antibiotics. The anti-biofilm potential of ETC was further substantiated under in vivo conditions using Caenorhabditis elegans. This study reports a novel anti-biofilm combination that could be developed as an ideal therapeutic agent with broad cosmeceutical and pharmaceutical applicability in the era of antibiotic resistance.
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Affiliation(s)
| | | | | | | | - Venkat Krishnan
- b Personal Care Division , ITC R&D Centre , Bengaluru , India
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Primary Amine Oxidase of Escherichia coli Is a Metabolic Enzyme that Can Use a Human Leukocyte Molecule as a Substrate. PLoS One 2015; 10:e0142367. [PMID: 26556595 PMCID: PMC4640556 DOI: 10.1371/journal.pone.0142367] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/21/2015] [Indexed: 12/17/2022] Open
Abstract
Escherichia coli amine oxidase (ECAO), encoded by the tynA gene, catalyzes the oxidative deamination of aromatic amines into aldehydes through a well-established mechanism, but its exact biological role is unknown. We investigated the role of ECAO by screening environmental and human isolates for tynA and characterizing a tynA-deletion strain using microarray analysis and biochemical studies. The presence of tynA did not correlate with pathogenicity. In tynA+ Escherichia coli strains, ECAO enabled bacterial growth in phenylethylamine, and the resultant H2O2 was released into the growth medium. Some aminoglycoside antibiotics inhibited the enzymatic activity of ECAO, which could affect the growth of tynA+ bacteria. Our results suggest that tynA is a reserve gene used under stringent environmental conditions in which ECAO may, due to its production of H2O2, provide a growth advantage over other bacteria that are unable to manage high levels of this oxidant. In addition, ECAO, which resembles the human homolog hAOC3, is able to process an unknown substrate on human leukocytes.
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Pritchard RE, Balish MF. Mycoplasma iowae: relationships among oxygen, virulence, and protection from oxidative stress. Vet Res 2015; 46:36. [PMID: 25880161 PMCID: PMC4367981 DOI: 10.1186/s13567-015-0170-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/05/2015] [Indexed: 12/20/2022] Open
Abstract
The poultry-associated bacterium Mycoplasma iowae colonizes multiple sites in embryos, with disease or death resulting. Although M. iowae accumulates in the intestinal tract, it does not cause disease at that site, but rather only in tissues that are exposed to atmospheric O2. The activity of M. iowae catalase, encoded by katE, is capable of rapid removal of damaging H2O2 from solution, and katE confers a substantial reduction in the amount of H2O2 produced by Mycoplasma gallisepticum katE transformants in the presence of glycerol. As catalase-producing bacteria are often beneficial to hosts with inflammatory bowel disease, we explored whether M. iowae was exclusively protective against H2O2-producing bacteria in a Caenorhabditis elegans model, whether its protectiveness changed in response to O2 levels, and whether expression of genes involved in H2O2 metabolism and virulence changed in response to O2 levels. We observed that M. iowae was in fact protective against H2O2-producing Streptococcus pneumoniae, but not HCN-producing Pseudomonas aeruginosa, and that M. iowae cells grown in 1% O2 promoted survival of C. elegans to a greater extent than M. iowae cells grown in atmospheric O2. Transcript levels of an M. iowae gene encoding a homolog of Mycoplasma pneumoniae CARDS toxin were 5-fold lower in cells grown in low O2. These data suggest that reduced O2, representing the intestinal environment, triggers M. iowae to reduce its virulence capabilities, effecting a change from a pathogenic mode to a potentially beneficial one.
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Affiliation(s)
- Rachel E Pritchard
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA. .,Present address: Division of Natural Sciences and Mathematics, Kentucky Wesleyan College, Owensboro, KY, 42301, USA.
| | - Mitchell F Balish
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA.
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Henningham A, Döhrmann S, Nizet V, Cole JN. Mechanisms of group A Streptococcus resistance to reactive oxygen species. FEMS Microbiol Rev 2015; 39:488-508. [PMID: 25670736 PMCID: PMC4487405 DOI: 10.1093/femsre/fuu009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/19/2014] [Indexed: 12/16/2022] Open
Abstract
Streptococcus pyogenes, also known as group A Streptococcus (GAS), is an exclusively human Gram-positive bacterial pathogen ranked among the ‘top 10’ causes of infection-related deaths worldwide. GAS commonly causes benign and self-limiting epithelial infections (pharyngitis and impetigo), and less frequent severe invasive diseases (bacteremia, toxic shock syndrome and necrotizing fasciitis). Annually, GAS causes 700 million infections, including 1.8 million invasive infections with a mortality rate of 25%. In order to establish an infection, GAS must counteract the oxidative stress conditions generated by the release of reactive oxygen species (ROS) at the infection site by host immune cells such as neutrophils and monocytes. ROS are the highly reactive and toxic byproducts of oxygen metabolism, including hydrogen peroxide (H2O2), superoxide anion (O2•−), hydroxyl radicals (OH•) and singlet oxygen (O2*), which can damage bacterial nucleic acids, proteins and cell membranes. This review summarizes the enzymatic and regulatory mechanisms utilized by GAS to thwart ROS and survive under conditions of oxidative stress. This review discusses the mechanisms utilized by the bacterial pathogen group A Streptococcus to detoxify reactive oxygen species and survive in the human host under conditions of oxidative stress.
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Affiliation(s)
- Anna Henningham
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA The School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia The Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Simon Döhrmann
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA Rady Children's Hospital, San Diego, CA 92123, USA
| | - Jason N Cole
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA The School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia The Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, QLD 4072, Australia
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O’Connor BP, Danhorn T, De Arras L, Flatley BR, Marcus RA, Farias-Hesson E, Leach SM, Alper S. Regulation of toll-like receptor signaling by the SF3a mRNA splicing complex. PLoS Genet 2015; 11:e1004932. [PMID: 25658809 PMCID: PMC4450051 DOI: 10.1371/journal.pgen.1004932] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 12/02/2014] [Indexed: 12/31/2022] Open
Abstract
The innate immune response plays a key role in fighting infection by activating inflammation and stimulating the adaptive immune response. However, chronic activation of innate immunity can contribute to the pathogenesis of many diseases with an inflammatory component. Thus, various negatively acting factors turn off innate immunity subsequent to its activation to ensure that inflammation is self-limiting and to prevent inflammatory disease. These negatively acting pathways include the production of inhibitory acting alternate proteins encoded by alternative mRNA splice forms of genes in Toll-like receptor (TLR) signaling pathways. We previously found that the SF3a mRNA splicing complex was required for a robust innate immune response; SF3a acts to promote inflammation in part by inhibiting the production of a negatively acting splice form of the TLR signaling adaptor MyD88. Here we inhibit SF3a1 using RNAi and subsequently perform an RNAseq study to identify the full complement of genes and splicing events regulated by SF3a in murine macrophages. Surprisingly, in macrophages, SF3a has significant preference for mRNA splicing events within innate immune signaling pathways compared with other biological pathways, thereby affecting the splicing of specific genes in the TLR signaling pathway to modulate the innate immune response. Within minutes after we are exposed to pathogens, our bodies react with a rapid response known as the “innate immune response.” This arm of the immune response regulates the process of inflammation, in which various immune cells are recruited to sites of infection and are activated to produce a host of antimicrobial compounds. This response is critical to fight infection. However, this response, if it is activated too strongly or if it becomes chronic, can do damage and can contribute to numerous very common diseases ranging from atherosclerosis to asthma to cancer. Thus it is essential that this response be tightly regulated, turned on when we have an infection, and turned off when not needed. We are investigating a mechanism that helps turn off this response, to ensure that inflammation is limited to prevent inflammatory disease. This mechanism involves the production of alternate forms of RNAs and proteins that control inflammation. We have discovered that a protein known as SF3a1 can regulate the expression of these alternate inhibitory RNA forms and are investigating how to use this knowledge to better control inflammation.
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Affiliation(s)
- Brian P. O’Connor
- Department of Pediatrics, National Jewish Health, Denver, Colorado, United States of America
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
- Department of Biomedical Research, National Jewish Health, Denver, Colorado, United States of America
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, United States of America
| | - Thomas Danhorn
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
| | - Lesly De Arras
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
| | - Brenna R. Flatley
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
- Department of Biomedical Research, National Jewish Health, Denver, Colorado, United States of America
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, United States of America
| | - Roland A. Marcus
- Department of Pediatrics, National Jewish Health, Denver, Colorado, United States of America
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
| | - Eveline Farias-Hesson
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
| | - Sonia M. Leach
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
| | - Scott Alper
- Integrated Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, United States of America
- Department of Biomedical Research, National Jewish Health, Denver, Colorado, United States of America
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, United States of America
- * E-mail:
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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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Bhatla N, Horvitz HR. Light and hydrogen peroxide inhibit C. elegans Feeding through gustatory receptor orthologs and pharyngeal neurons. Neuron 2015; 85:804-18. [PMID: 25640076 DOI: 10.1016/j.neuron.2014.12.061] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/11/2014] [Accepted: 12/22/2014] [Indexed: 11/29/2022]
Abstract
While gustatory sensing of the five primary flavors (sweet, salty, sour, bitter, and savory) has been extensively studied, pathways that detect non-canonical taste stimuli remain relatively unexplored. In particular, while reactive oxygen species cause generalized damage to biological systems, no gustatory mechanism to prevent ingestion of such material has been identified in any organism. We observed that light inhibits C. elegans feeding and used light as a tool to uncover molecular and neural mechanisms for gustation. Light can generate hydrogen peroxide, and we discovered that hydrogen peroxide similarly inhibits feeding. The gustatory receptor family members LITE-1 and GUR-3 are required for the inhibition of feeding by light and hydrogen peroxide. The I2 pharyngeal neurons increase calcium in response to light and hydrogen peroxide, and these responses require GUR-3 and a conserved antioxidant enzyme peroxiredoxin PRDX-2. Our results demonstrate a gustatory mechanism that mediates the detection and blocks ingestion of a non-canonical taste stimulus, hydrogen peroxide.
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Affiliation(s)
- Nikhil Bhatla
- Howard Hughes Medical Institute, Department of Biology, McGovern Institute for Brain Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - H Robert Horvitz
- Howard Hughes Medical Institute, Department of Biology, McGovern Institute for Brain Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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Pritchard RE, Prassinos AJ, Osborne JD, Raviv Z, Balish MF. Reduction of hydrogen peroxide accumulation and toxicity by a catalase from Mycoplasma iowae. PLoS One 2014; 9:e105188. [PMID: 25127127 PMCID: PMC4134286 DOI: 10.1371/journal.pone.0105188] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/19/2014] [Indexed: 12/02/2022] Open
Abstract
Mycoplasma iowae is a well-established avian pathogen that can infect and damage many sites throughout the body. One potential mediator of cellular damage by mycoplasmas is the production of H2O2 via a glycerol catabolic pathway whose genes are widespread amongst many mycoplasma species. Previous sequencing of M. iowae serovar I strain 695 revealed the presence of not only genes for H2O2 production through glycerol catabolism but also the first documented mycoplasma gene for catalase, which degrades H2O2. To test the activity of M. iowae catalase in degrading H2O2, we studied catalase activity and H2O2 accumulation by both M. iowae serovar K strain DK-CPA, whose genome we sequenced, and strains of the H2O2-producing species Mycoplasma gallisepticum engineered to produce M. iowae catalase by transformation with the M. iowae putative catalase gene, katE. H2O2-mediated virulence by M. iowae serovar K and catalase-producing M. gallisepticum transformants were also analyzed using a Caenorhabditis elegans toxicity assay, which has never previously been used in conjunction with mycoplasmas. We found that M. iowae katE encodes an active catalase that, when expressed in M. gallisepticum, reduces both the amount of H2O2 produced and the amount of damage to C. elegans in the presence of glycerol. Therefore, the correlation between the presence of glycerol catabolism genes and the use of H2O2 as a virulence factor by mycoplasmas might not be absolute.
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Affiliation(s)
- Rachel E. Pritchard
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | | | - John D. Osborne
- Center for Clinical and Translational Science, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Ziv Raviv
- Department of Veterinary Preventative Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Mitchell F. Balish
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
- * E-mail:
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Borgo F, Ballestriero F, Ferrario C, Fortina MG. Hydrogen peroxide-mediated killing of Caenorhabditis elegans by Enterococcus italicus and Lactococcus garvieae isolated from food. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0924-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Qabazard B, Ahmed S, Li L, Arlt VM, Moore PK, Stürzenbaum SR. C. elegans aging is modulated by hydrogen sulfide and the sulfhydrylase/cysteine synthase cysl-2. PLoS One 2013; 8:e80135. [PMID: 24260346 PMCID: PMC3832670 DOI: 10.1371/journal.pone.0080135] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 09/30/2013] [Indexed: 12/28/2022] Open
Abstract
Exogenous hydrogen sulfide (H2S) administration and endogenous H2S metabolism were explored in the nematode C. elegans. Chronic treatment with a slow-releasing H2S donor, GYY4137, extended median survival by 17-23% and increased tolerance towards oxidative and endoplasmic reticulum (ER) stress. Also, cysl-2, a sulfhydrylase/cysteine synthase in C. elegans, was transcriptionally upregulated by GYY4137 treatment and the deletion of cysl-2 resulted in a significant reduction in lifespan which was partially recovered by the supplementation of GYY4137. Likewise, a mammalian cell culture system, GYY4137 was able to protect bovine aortic endothelial cells (BAECs) from oxidative stress and (H2O2)-induced cell death. Taken together, this provides further support that H2S exerts a protective function which is consistent with the longevity dividend theory. Overall, this study underlines the therapeutic potential of a slow-releasing H2S donor as regulators of the aging and cellular stress pathways.
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Affiliation(s)
- Bedoor Qabazard
- School of Biomedical Sciences, King's College London, London, United Kingdom
| | - Samanza Ahmed
- School of Biomedical Sciences, King's College London, London, United Kingdom
| | - Ling Li
- School of Biomedical Sciences, King's College London, London, United Kingdom
| | - Volker M. Arlt
- School of Biomedical Sciences, King's College London, London, United Kingdom
| | - Philip K. Moore
- Neurobiology Group, Life Sciences Institute and Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Live and dead GFP-tagged bacteria showed indistinguishable fluorescence in Caenorhabditis elegans gut. J Microbiol 2013; 51:367-72. [PMID: 23812817 DOI: 10.1007/s12275-013-2589-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/28/2013] [Indexed: 12/19/2022]
Abstract
Caenorhabditis elegans has been used for studying host-pathogen interactions since long, and many virulence genes of pathogens have been successfully identified. In several studies, fluorescent pathogens were fed to C. elegans and fluorescence observed in the gut was considered an indicator for bacterial colonization. However, the grinder in the pharynx of these nematodes supposedly crushes the bacterial cells, and the ground material is delivered to the intestine for nutrient absorption. Therefore, it remains unclear whether intact bacteria pass through the grinder and colonize in the intestine. Here we investigated whether the appearance of fluorescence is indicative of intact bacteria in the gut using both fluorescence microscopy and transmission electron microscopy. In wild-type N2 C. elegans, Escherichia coli DH5α, and Vibrio vulnificus 93U204, both of which express the green fluorescence protein, were found intact only proximal to the grinder, while crushed bacterial debris was found in the post-pharyngeal lumen. Nevertheless, the fluorescence was evident throughout the lumen of worm intestines irrespective of whether the bacteria were intact or not. We further investigated the interaction of the bacteria with C. elegans phm-2 mutant, which has a dysfunctional grinder. Both strains of bacteria were found to be intact and accumulated in the pharynx and intestine owing to the defective grinder. The fluorescence intensity of intact bacteria in phm-2 worms was indistinguishable from that of crushed bacterial debris in N2 worms. Therefore, appearance of fluorescence in the C. elegans intestine should not be directly interpreted as successful bacterial colonization in the intestine.
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A cytoprotective perspective on longevity regulation. Trends Cell Biol 2013; 23:409-20. [PMID: 23726168 DOI: 10.1016/j.tcb.2013.04.007] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 02/07/2023]
Abstract
There are many mechanisms of lifespan extension, including the disruption of insulin/insulin-like growth factor 1 (IGF-1) signaling, metabolism, translation, and feeding. Despite the disparate functions of these pathways, inhibition of each induces responses that buffer stress and damage. Here, emphasizing data from genetic analyses in Caenorhabditis elegans, we explore the effectors and upstream regulatory components of numerous cytoprotective mechanisms activated as major elements of longevity programs, including detoxification, innate immunity, proteostasis, and oxidative stress response. We show that their induction underpins longevity extension across functionally diverse triggers and across species. Intertwined with the evolution of longevity, cytoprotective pathways are coupled to the surveillance of core cellular components, with important implications in normal and aberrant responses to drugs, chemicals, and pathogens.
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Pathogenicity of Salmonella enterica in Caenorhabditis elegans relies on disseminated oxidative stress in the infected host. PLoS One 2012; 7:e45417. [PMID: 23028994 PMCID: PMC3461013 DOI: 10.1371/journal.pone.0045417] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/20/2012] [Indexed: 12/26/2022] Open
Abstract
Feeding Caenorhabditis elegans with Salmonella enterica serovar Typhimurium significantly shortens the lifespan of the nematode. S. Typhimurium-infected C. elegans, stained with 2′,7′-dichlorodihydrofluorescein diacetate which fluoresces upon exposure to reactive oxygen species, revealed intestinal luminal staining that along with the time of infection progressed to a strong staining in the hypodermal tissues of the nematode. Still, we could not detect invasion beyond the nematode's intestinal epithelium at any stage of the infection. A similar dispersion of oxidative response was also noted in nematodes infected with S. Dublin, but not with non-pathogenic Escherichia coli or the defined pathogen Burkholderia thailandensis. Addition of catalase or the reductant ascorbic acid significantly restored the lifespan of S. Typhimurium-infected nematodes. Mutational inactivation of the bacterial thioredoxin 1 resulted in total ablation of the hypodermal oxidative response to infection, and in a strong attenuation of virulence. Virulence of the thioredoxin 1 mutant was restored by trans-complementation with redox-active variants of thioredoxin 1 or, surprisingly, by exposing the thioredoxin 1 mutant to sublethal concentrations of the disulphide catalyst copper chloride prior to infection. In summary, our observations define a new aspect in virulence of S. enterica that apparently does not involve the classical invasive or intracellular phenotype of the pathogen, but that depends on the ability to provoke overwhelming systemic oxidative stress in the host through the redox activity of bacterial thioredoxin 1.
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Monascus-fermented dioscorea enhances oxidative stress resistance via DAF-16/FOXO in Caenorhabditis elegans. PLoS One 2012; 7:e39515. [PMID: 22745774 PMCID: PMC3382167 DOI: 10.1371/journal.pone.0039515] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 05/27/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Monascus-fermented products are mentioned in an ancient Chinese pharmacopoeia of medicinal food and herbs. Monascus-fermented products offer valuable therapeutic benefits and have been extensively used in East Asia for several centuries. Several biological activities of Monascus-fermented products were recently described, and the extract of Monascus-fermented products showed strong antioxidant activity of scavenging DPPH radicals. To evaluate whether Monascus-fermented dioscorea products have potential as nutritional supplements, Monascus-fermented dioscorea's modulation of oxidative-stress resistance and associated regulatory mechanisms in Caenorhabditis elegans were investigated. PRINCIPAL FINDINGS We examined oxidative stress resistance of the ethanol extract of red mold dioscorea (RMDE) in C. elegans, and found that RMDE-treated wild-type C. elegans showed an increased survival during juglone-induced oxidative stress compared to untreated controls, whereas the antioxidant phenotype was absent from a daf-16 mutant. In addition, the RMDE reduced the level of intracellular reactive oxygen species in C. elegans. Finally, the RMDE affected the subcellular distribution of the FOXO transcription factor, DAF-16, in C. elegans and induced the expression of the sod-3 antioxidative gene. CONCLUSIONS These findings suggest that the RMDE acts as an antioxidative stress agent and thus may have potential as a nutritional supplement. Further studies in C. elegans suggest that the antioxidant effect of RMDE is mediated via regulation of the DAF-16/FOXO-dependent pathway.
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Rangel NA, Lin L, Rakariyatham K, Bach A, Trinh K, Clement MHS, Srinivasan C. Unincorporated iron pool is linked to oxidative stress and iron levels in Caenorhabditis elegans. Biometals 2012; 25:971-85. [PMID: 22684251 DOI: 10.1007/s10534-012-9563-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 05/22/2012] [Indexed: 11/28/2022]
Abstract
Free radicals or reactive oxygen species (ROS) are relatively short-lived and are difficult to measure directly; so indirect methods have been explored for measuring these transient species. One technique that has been developed using Escherichia coli and Saccharomyces cerevisiae systems, relies on a connection between elevated superoxide levels and the build-up of a high-spin form of iron (Fe(III)) that is detectable by electron paramagnetic resonance (EPR) spectroscopy at g = 4.3. This form of iron is referred to as "free" iron. EPR signals at g = 4.3 are commonly encountered in biological samples owing to mononuclear high-spin (S = 5/2) Fe(III) ions in sites of low symmetry. Unincorporated iron in this study refers to this high-spin Fe(III) that is captured by desferrioxamine which is detected by EPR at g value of 4.3. Previously, we published an adaptation of Fe(III) EPR methodology that was developed for Caenorhabditis elegans, a multi-cellular organism. In the current study, we have systematically characterized various factors that modulate this unincorporated iron pool. Our results demonstrate that the unincorporated iron as monitored by Fe(III) EPR at g = 4.3 increased under conditions that were known to elevate steady-state ROS levels in vivo, including: paraquat treatment, hydrogen peroxide exposure, heat shock treatment, or exposure to higher growth temperature. Besides the exogenous inducers of oxidative stress, physiological aging, which is associated with elevated ROS and ROS-mediated macromolecular damage, also caused a build-up of this iron. In addition, increased iron availability increased the unincorporated iron pool as well as generalized oxidative stress. Overall, unincorporated iron increased under conditions of oxidative stress with no change in total iron levels. However, when total iron levels increased in vivo, an increase in both the pool of unincorporated iron and oxidative stress was observed suggesting that the status of the unincorporated iron pool is linked to oxidative stress and iron levels.
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Affiliation(s)
- Natalie A Rangel
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, CA 92834, USA
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Papp D, Csermely P, Sőti C. A role for SKN-1/Nrf in pathogen resistance and immunosenescence in Caenorhabditis elegans. PLoS Pathog 2012; 8:e1002673. [PMID: 22577361 PMCID: PMC3343120 DOI: 10.1371/journal.ppat.1002673] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 03/13/2012] [Indexed: 11/18/2022] Open
Abstract
A proper immune response ensures survival in a hostile environment and promotes longevity. Recent evidence indicates that innate immunity, beyond antimicrobial effectors, also relies on host-defensive mechanisms. The Caenorhabditis elegans transcription factor SKN-1 regulates xenobiotic and oxidative stress responses and contributes to longevity, however, its role in immune defense is unknown. Here we show that SKN-1 is required for C. elegans pathogen resistance against both Gram-negative Pseudomonas aeruginosa and Gram-positive Enterococcus faecalis bacteria. Exposure to P. aeruginosa leads to SKN-1 accumulation in intestinal nuclei and transcriptional activation of two SKN-1 target genes, gcs-1 and gst-4. Both the Toll/IL-1 Receptor domain protein TIR-1 and the p38 MAPK PMK-1 are required for SKN-1 activation by PA14 exposure. We demonstrate an early onset of immunosenescence with a concomitant age-dependent decline in SKN-1-dependent target gene activation, and a requirement of SKN-1 to enhance pathogen resistance in response to longevity-promoting interventions, such as reduced insulin/IGF-like signaling and preconditioning H(2)O(2) treatment. Finally, we find that wdr-23(RNAi)-mediated constitutive SKN-1 activation results in excessive transcription of target genes, confers oxidative stress tolerance, but impairs pathogen resistance. Our findings identify SKN-1 as a novel regulator of innate immunity, suggests its involvement in immunosenescence and provide an important crosstalk between pathogenic stress signaling and the xenobiotic/oxidative stress response.
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Affiliation(s)
- Diána Papp
- Department of Medical Chemistry, Semmelweis University, Budapest, Hungary
| | - Péter Csermely
- Department of Medical Chemistry, Semmelweis University, Budapest, Hungary
| | - Csaba Sőti
- Department of Medical Chemistry, Semmelweis University, Budapest, Hungary
- * E-mail:
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Zhang Y, Fu D, Yu F, Liu Q, Yu Z. Two catalase homologs are involved in host protection against bacterial infection and oxidative stress in Crassostrea hongkongensis. FISH & SHELLFISH IMMUNOLOGY 2011; 31:894-903. [PMID: 21871567 DOI: 10.1016/j.fsi.2011.08.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 05/31/2023]
Abstract
Catalase is one of the key antioxidant enzymes and it appears to be involved in protection against immune infection and oxidative stress. Here, two catalase cDNAs (ChCat-1 and ChCat-2) were isolated from hemocytes of Crassostrea hongkongensis using SSH and RACE. The full-length cDNAs of ChCat-1 and ChCat-2 are 1913 and 2466 bp in length, encoding proteins of 515 and 511 amino acids, respectively. Multiple alignments of amino acid sequences revealed that both ChCat-1 and ChCat-2 possess several characteristic features of the catalase family of enzymes, including one proximal active site signature, one heme-ligand signature, and three catalytic amino acid residues (His(72), Asn(145) and Tyr(355)). Phylogenetic analysis indicates that these two catalases may share a common ancestral gene and result from a gene duplication event following the divergence of bivalves and gastropods. Constitutive expression of ChCat-1 and ChCat-2 was observed in all tissues studied, with highest levels of expression in gill and muscle, respectively. The expression of both genes was inducible by bacterial infection, and reached the maximum at 8 h (9.0-fold) and 12 h (2.3-fold) post-infection, respectively. Furthermore, both the purified ChCat-1 and ChCat-2 protein displayed a strong catalase activity, and S2 cells carrying ChCat-1 or ChCat-2 showed a higher degree of resistance to H(2)O(2) than that of control cells. In a word, this is the first report of the presence of two catalase genes in a single marine bivalve, and our results highlight the involvement of both ChCat-1 and ChCat-2 in host protection against pathogen infection and oxidative stress in C. hongkongensis.
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Affiliation(s)
- Yang Zhang
- Key Laboratory of Marine Bio-resources Sustainable Utilization, Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China
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Bakkiyaraj D, Pandian SK. In vitro and in vivo antibiofilm activity of a coral associated actinomycete against drug resistant Staphylococcus aureus biofilms. BIOFOULING 2010; 26:711-717. [PMID: 20706890 DOI: 10.1080/08927014.2010.511200] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Staphylococcus aureus is now amongst the most important pathogenic bacteria responsible for bloodstream nosocomial infections and for biofilm formation on indwelling medical devices. Its increasing resistance to common antibiotics, partly attributed to its ability to form biofilms, is a challenge for the development of new antimicrobial agents. Accordingly, the goal of this study was to evaluate the effect of a coral associated actinomycete (CAA)-3 on S. aureus biofilms both in vitro and in vivo. Methanolic extracts of CAA-3 showed a reduction in in vitro biofilm formation by S. aureus ATCC 11632, methicillin resistant S. aureus ATCC 33591 and clinical isolates of S. aureus at the biofilm inhibitory concentration (BIC) of 0.1 mg ml(-1). Furthermore, confocal laser scanning microscope (CLSM) studies provide evidence of CAA-3 inhibiting intestinal colonisation of S. aureus in the nematode Caenorhabditis elegans. To conclude, this study for the first time, reports CAA as a promising source of anti-biofilm compounds, for developing novel drugs against highly resistant staphylococcal biofilms.
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Quorum-quenching acylase reduces the virulence of Pseudomonas aeruginosa in a Caenorhabditis elegans infection model. Antimicrob Agents Chemother 2009; 53:4891-7. [PMID: 19721066 DOI: 10.1128/aac.00380-09] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Pseudomonas aeruginosa PAO1 gene pvdQ encodes an acyl-homoserine lactone (AHL) acylase capable of degrading N-(3-oxododecanoyl)-L-homoserine lactone by cleaving the AHL amide. PvdQ has been proven to function as a quorum quencher in vitro in a number of phenotypic assays. To address the question of whether PvdQ also shows quorum-quenching properties in vivo, an infection model based on the nematode Caenorhabditis elegans was explored. In a fast-acting paralysis assay, strain PAO1(pMEpvdQ), which overproduces PvdQ, was shown to be less virulent than the wild-type strain. More than 75% of the nematodes exposed to PAO1(pMEpvdQ) survived and continued to grow when using this strain as a food source. Interestingly, in a slow-killing assay monitoring the survival of the nematodes throughout a 4-day course, strain PAO1-Delta pvdQ was shown to be more virulent than the wild-type strain, confirming the role of PvdQ as a virulence-reducing agent. It was observed that larval stage 1 (L1) to L3-stage larvae benefit much more from protection by PvdQ than L4 worms. Finally, purified PvdQ protein was added to C. elegans worms infected with wild-type PAO1, and this resulted in reduced pathogenicity and increased the life span of the nematodes. From our observations we can conclude that PvdQ might be a strong candidate for antibacterial therapy against Pseudomonas infections.
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A pathogenesis assay using Saccharomyces cerevisiae and Caenorhabditis elegans reveals novel roles for yeast AP-1, Yap1, and host dual oxidase BLI-3 in fungal pathogenesis. EUKARYOTIC CELL 2009; 8:1218-27. [PMID: 19502579 DOI: 10.1128/ec.00367-08] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Treatment of systemic fungal infections is difficult because of the limited number of antimycotic drugs available. Thus, there is an immediate need for simple and innovative systems to assay the contribution of individual genes to fungal pathogenesis. We have developed a pathogenesis assay using Caenorhabditis elegans, an established model host, with Saccharomyces cerevisiae as the invading fungus. We have found that yeast infects nematodes, causing disease and death. Our data indicate that the host produces reactive oxygen species (ROS) in response to fungal infection. Yeast mutants sod1Delta and yap1Delta, which cannot withstand ROS, fail to cause disease, except in bli-3 worms, which carry a mutation in a dual oxidase gene. Chemical inhibition of the NADPH oxidase activity abolishes ROS production in worms exposed to yeast. This pathogenesis assay is useful for conducting systematic, whole-genome screens to identify fungal virulence factors as alternative targets for drug development and exploration of host responses to fungal infections.
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Virulent synergistic effect between Enterococcus faecalis and Escherichia coli assayed by using the Caenorhabditis elegans model. PLoS One 2008; 3:e3370. [PMID: 18843374 PMCID: PMC2557124 DOI: 10.1371/journal.pone.0003370] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 09/16/2008] [Indexed: 12/12/2022] Open
Abstract
Background The role of enterococci in the pathogenesis of polymicrobial infections is still debated. The purpose of this study was to evaluate the effect of virulent enterococci in the presence or absence of Escherichia coli strains in the in vivo Caenorhabditis elegans model. Principal Findings This study demonstrated that there was a synergistic effect on virulence when an association of enterococci and E. coli (LT50 = 1.6 days±0.1 according to the tested strains and death of nematodes in 4 days±0.5) was tested in comparison with enterococci alone (LT50 = 4.6 days±0.1 and death in 10.4 days±0.6) or E. coli alone (LT50 = 2.1±0.9 and deaths 6.6±0.6) (p<0.001). In addition, there was a relation between the virulence of E. faecalis strains alone and the virulence potential of the association with E. coli strains. Finally, in the presence of avirulent E. coli strains, enterococci have no effect (LT50 = 4.3±0.5 and deaths in 10.8±0.8), independently of the level of their own virulence, demonstrating that the ‘enterococci effect’ only occurred in the presence of virulent E. coli strains. Conclusion This study allows a better understanding of a bacterial cooperation. Moreover, it could help to optimize the antibiotic regimen during polymicrobial infections.
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An iron-binding protein, Dpr, decreases hydrogen peroxide stress and protects Streptococcus pyogenes against multiple stresses. Infect Immun 2008; 76:4038-45. [PMID: 18541662 DOI: 10.1128/iai.00477-08] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Streptococcus pyogenes does not produce catalase, but it can grow in aerobic environments and survive in the presence of peroxide. One of the stress proteins of this organism, peroxide resistance protein (Dpr), has been studied to examine its role in resistance to hydrogen peroxide, but the protective mechanism of Dpr is not clear. The aim of this study was to characterize the dpr gene and its role in dealing with different stresses. A dpr deletion mutant was constructed by double-crossover mutagenesis. The dpr mutant was more sensitive to H(2)O(2), and complementation could partially restore the defect in the mutant. Pretreatment with the iron chelator deferoxamine mesylate rescued the survival activity of the mutant under oxidative stress conditions. The dpr mutant also showed a low survival rate in the long-term stationary phase, when it was treated with extreme acids, and under alkaline pH conditions compared to the wild-type strain. The growth of the dpr mutant was slower than that of the wild-type strain in iron-limiting conditions. The dpr mutant showed high sensitivity to iron and zinc but not to manganese, copper, nickel, and calcium. Recombinant Dpr protein was purified and showed iron-binding activity, whereas no DNA-binding activity was found. These data indicate that an iron-binding protein, Dpr, provides protection from hydrogen peroxide stress by preventing the Fenton reaction, and Dpr was identified as a novel stress protein that protects against several stresses in group A streptococci.
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Chávez V, Mohri-Shiomi A, Maadani A, Vega LA, Garsin DA. Oxidative stress enzymes are required for DAF-16-mediated immunity due to generation of reactive oxygen species by Caenorhabditis elegans. Genetics 2007; 176:1567-77. [PMID: 17483415 PMCID: PMC1931534 DOI: 10.1534/genetics.107.072587] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Caenorhabditis elegans has recently been developed as a model for microbial pathogenesis, yet little is known about its immunological defenses. Previous work implicated insulin signaling in mediating pathogen resistance in a manner dependent on the transcriptional regulator DAF-16, but the mechanism has not been elucidated. We present evidence that C. elegans, like mammalian phagocytes, produces reactive oxygen species (ROS) in response to pathogens. Signs of oxidative stress occur in the intestine - the site of the host-pathogen interface - suggesting that ROS release is localized to this tissue. Evidence includes the accumulation of lipofuscin, a pigment resulting from oxidative damage, at this site. In addition, SOD-3, a superoxide dismutase regulated by DAF-16, is induced in intestinal tissue after exposure to pathogenic bacteria. Moreover, we show that the oxidative stress response genes sod-3 and ctl-2 are required for DAF-16-mediated resistance to Enterococcus faecalis using a C. elegans killing assay. We propose a model whereby C. elegans responds to pathogens by producing ROS in the intestine while simultaneously inducing a DAF-16-dependent oxidative stress response to protect adjacent tissues. Because insulin-signaling mutants overproduce oxidative stress response enzymes, the model provides an explanation for their increased resistance to pathogens.
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Affiliation(s)
- Violeta Chávez
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas 77030, USA
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Kim Y, Oh S, Ahn EY, Imm JY, Oh S, Park S, Kim SH. Proteome analysis of virulence factor regulated by autoinducer-2-like activity in Escherichia coli O157:H7. J Food Prot 2007; 70:300-7. [PMID: 17340862 DOI: 10.4315/0362-028x-70.2.300] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Many pathogenic bacteria, including Escherichia coli O157:H7, can control gene expression in a cell density-dependent manner by producing small signaling molecules (autoinducers) in a process known as quorum sensing. In this study, the effects of the autoinducer-2-like activity on the expression of proteins, including virulence factors, in E. coli O157:H7 were characterized by proteomic analysis. Compared with the control, E. coli O157:H7 strains in the presence of autoinducer-2-like activity exhibited elevated virulence by more rapidly forming cell aggregates on epithelial cells and rapidly killing the nematode Caenorhabditis elegans, the surrogate host. Two-dimensional gel electrophoresis revealed 18 proteins that were upregulated by autoinducer-2-like activity and 4 proteins that were down-regulated. These proteins were further characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry and are involved in the metabolic process, adaptation and protection, cell motility, secretion, envelope biogenesis, and protein translation. These results indicate that the newly identified proteins are associated with the control of virulence in E. coli O157:H7 and that these proteins can be potential targets for the development of antibiotics and other antimicrobial agents.
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Affiliation(s)
- Younghoon Kim
- Division of Food Science, Korea University, Seoul 136-701, Korea
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Kim Y, Han KS, Imm JY, Oh S, You S, Park S, Kim SH. Inhibitory effects ofLactobacillus acidophiluslysates on the cytotoxic activity of shiga-like toxin 2 produced fromEscherichia coliO157:H7. Lett Appl Microbiol 2006; 43:502-7. [PMID: 17032223 DOI: 10.1111/j.1472-765x.2006.02005.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AIMS The purpose of this study was to characterize the degree to which four cell lysates obtained from Lactobacillus acidophilus strains affected the cytotoxic activity of Escherichia coli O157:H7 in vitro and in vivo. METHODS AND RESULTS In a cytotoxic inhibition test that used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and toxin-binding ELISA assays, the activity of shiga-like toxin 2 (Stx-2) was inhibited profoundly by the cell lysates (10 mg ml(-1)) from two strains of L. acidophilus A4 and 30SC (>85% of survival rates compared with the control) among the five strains tested. In particular, a significant decline in the virulence level of E. coli O157:H7, under the presence of the cell lysates of L. acidophilus A4, was observed by killing assay of Caenorhabditis elegans in vivo model. CONCLUSIONS According to our results, L. acidophilus strains might be capable of attenuating the virulence of Stx-2 produced from E. coli O157:H7. SIGNIFICANCE AND IMPACT OF THE STUDY The cell lysates of L. acidophilus can be applied to a variety of foods, and can be used as adjuncts for the inhibition of Stx-2-mediated cytotoxicity.
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Affiliation(s)
- Y Kim
- Division of Food Science, Korea University, Seoul, Korea
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Lavigne JP, Blanc-Potard AB, Bourg G, O'callaghan D, Sotto A. Caenorhabditis elegans : modèle d'étude in vivo de la virulence bactérienne. ACTA ACUST UNITED AC 2006; 54:439-46. [PMID: 17027180 DOI: 10.1016/j.patbio.2006.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 07/18/2006] [Indexed: 01/22/2023]
Abstract
The nematode Caenorhabditis elegans presents many advantages as a model system. The worm has recently emerged as a potentially useful tool for the study of host-pathogen interactions. This paper presents advantages and inconveniences of this model, the variety of bacterial pathogens studied, and its use to monitor virulence of Extraintestinal Escherichia coli strains.
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Affiliation(s)
- J-P Lavigne
- Laboratoire de bactériologie, virologie, parasitologie, CHU de Nîmes, groupe hospitalo-universitaire de Carémeau, place du Professeur-Robert-Debré, 30029 Nîmes cedex 09, France.
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48
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Dhakal BK, Lee W, Kim YR, Choy HE, Ahnn J, Rhee JH. Caenorhabditis elegans as a simple model host for Vibrio vulnificus infection. Biochem Biophys Res Commun 2006; 346:751-7. [PMID: 16782063 DOI: 10.1016/j.bbrc.2006.05.168] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 05/24/2006] [Indexed: 12/20/2022]
Abstract
Vibrio vulnificus is a human opportunistic pathogen which causes fatal septicemia and necrotic wound infection, resulting in a high mortality (over 50%). Caenorhabditis elegans has been studied as a model experimental host for V. vulnificus infection. V. vulnificus was shown to kill C. elegans effectively on different growth media and culture conditions. A marked reduction was observed in the life spans of worms when they were fed on V. vulnificus rather than on the ordinary laboratory food source, Escherichia coli OP50. The intestines of the C. elegans fed on V. vulnificus were grossly distended. In the C. elegans infection model, a V. vulnificus global virulence regulator CRP mutant and an exotoxin mutant exhibited significantly extended host killing duration. Here, we have shown that the virulence factors essential to mammalian V. vulnificus infections also play important roles in the killing of C. elegans, and thereby suggest that C. elegans is a favorable model for host-parasite interaction.
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Affiliation(s)
- Bijaya Kumar Dhakal
- Department of Life Science, Gwangju Institute of Science and Technology, 1 Oryoung-dong, Gwangju 500-712, South Korea
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van den Berg MCW, Woerlee JZ, Ma H, May RC. Sex-dependent resistance to the pathogenic fungus Cryptococcus neoformans. Genetics 2006; 173:677-83. [PMID: 16582430 PMCID: PMC1526500 DOI: 10.1534/genetics.106.056093] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sex differences occur in most species and affect a variety of biological traits including morphology, behavior, and life history. The nematode Caenorhabditis elegans exists as a population of self-fertile hermaphrodites with occasional males, which differ anatomically and behaviorally from hermaphrodites. Here we show that male C. elegans also differ from hermaphrodites in their susceptibility to a fungal pathogen, Cryptococcus neoformans. Wild-type males show greater resistance than hermaphrodite animals to killing by this pathogen and this resistance can be induced in hermaphrodite animals by inappropriate activation of the male sex-determination pathway. Resistance is molecularly determined, rather than resulting from behavioral changes or reproductive differences, and requires the activity of the stress-response transcription factor DAF-16. Finally, we demonstrate that resistance to C. neoformans correlates broadly with longevity within the Caenorhabditis genus. Our results hint at an overlap between the pathways controlling immunity and longevity and raise the possibility that differential regulation of these pathways may contribute to sex-dependent and species-dependent variation.
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Dorer MS, Isberg RR. Non-vertebrate hosts in the analysis of host-pathogen interactions. Microbes Infect 2006; 8:1637-46. [PMID: 16697687 DOI: 10.1016/j.micinf.2005.11.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 11/30/2005] [Indexed: 01/12/2023]
Abstract
Mutations in bacterial pathogens have been isolated using many strategies. In contrast, the hosts they attack are significantly less tractable. To overcome this problem, a number of model host systems have been developed for isolation and investigation of mutations that modulate pathogen growth. These novel host models are either unicellular organisms, intact invertebrates or cells derived from invertebrates.
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Affiliation(s)
- Marion S Dorer
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA
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