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Cytotoxicity and Antimicrobial Resistance of Aeromonas Strains Isolated from Fresh Produce and Irrigation Water. Antibiotics (Basel) 2023; 12:antibiotics12030511. [PMID: 36978377 PMCID: PMC10044025 DOI: 10.3390/antibiotics12030511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
The genus Aeromonas has received constant attention in different areas, from aquaculture and veterinary medicine to food safety, where more and more frequent isolates are occurring with increased resistance to antibiotics. The present paper studied the interaction of Aeromonas strains isolated from fresh produce and water with different eukaryotic cell types with the aim of better understanding the cytotoxic capacity of these strains. To study host-cell pathogen interactions in Aeromonas, we used HT-29, Vero, J774A.1, and primary mouse embryonic fibroblasts. These interactions were analyzed by confocal microscopy to determine the cytotoxicity of the strains. We also used Galleria mellonella larvae to test their pathogenicity in this experimental model. Our results demonstrated that two strains showed high cytotoxicity in epithelial cells, fibroblasts, and macrophages. Furthermore, these strains showed high virulence using the G. mellonella model. All strains used in this paper generally showed low levels of resistance to the different families of the antibiotics being tested. These results indicated that some strains of Aeromonas present in vegetables and water pose a potential health hazard, displaying very high in vitro and in vivo virulence. This pathogenic potential, and some recent concerning findings on antimicrobial resistance in Aeromonas, encourage further efforts in examining the precise significance of Aeromonas strains isolated from foods for human consumption.
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Wang W, Tan S, Luo J, Shi H, Zhou T, Yang Y, Jin Y, Wang X, Niu D, Yuan Z, Gao D, Dunham R, Liu Z. GWAS Analysis Indicated Importance of NF-κB Signaling Pathway in Host Resistance Against Motile Aeromonas Septicemia Disease in Catfish. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2019; 21:335-347. [PMID: 30895402 DOI: 10.1007/s10126-019-09883-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Motile Aeromonas septicemia (MAS) disease caused by a bacterial pathogen, Aeromonas hydrophila, is an emerging but severe disease of catfish. Genetic enhancement of disease resistance is considered to be effective to control the disease. To provide an insight into the genomic basis of MAS disease resistance, in this study, we conducted a genome-wide association study (GWAS) to identify quantitative trait loci (QTL). A total of 1820 interspecific backcross catfish of 7 families were challenged with A. hydrophila, and 382 phenotypic extremes were selected for genotyping with the catfish 690 K SNP arrays. Three QTL on linkage group (LG) 2, 26 and 29 were identified to be significantly associated with MAS resistance. Within these regions, a total of 24 genes had known functions in immunity, 10 of which were involved in NF-κB signaling pathway, suggesting the importance of NF-κB signaling pathway in MAS resistance. In addition, three suggestively significant QTL were identified on LG 11, 17, and 20. The limited numbers of QTL involved in MAS resistance suggests that marker-assisted selection may be a viable approach for catfish breeding.
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Affiliation(s)
- Wenwen Wang
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Suxu Tan
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Jian Luo
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Huitong Shi
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Tao Zhou
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Yujia Yang
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Yulin Jin
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Xiaozhu Wang
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Donghong Niu
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zihao Yuan
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Dongya Gao
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Rex Dunham
- The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zhanjiang Liu
- Department of Biology, College of Art and Sciences, Syracuse University, Syracuse, NY, 13244, USA.
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Foysal MJ, Momtaz F, Ali MH, Siddik MAB, Chaklader MR, Rahman MM, Prodhan MSH, Cole A. Molecular characterization and interactome analysis of aerolysin (aer) gene from fish pathogen Aeromonas veronii: The pathogenicity inferred from sequence divergence and linked to histidine kinase (cheA). JOURNAL OF FISH DISEASES 2019; 42:465-475. [PMID: 30734315 DOI: 10.1111/jfd.12954] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 06/09/2023]
Abstract
Aerolysin (aer) is one of the most important and abundant virulence factors in the infection of fish by Aeromonas veronii. A comprehensive study on the molecular characterization and pathogenicity of the aer gene from 34 A. veronii isolates from diseased carp and catfish was carried out and its interactome was analysed to observe the functional correlations between aer and other proteins within the A. veronii network. The PCR-based amplification of aer from the 34 isolates of A. veronii showed more aer-positive isolates from catfish with a high pathogenic potential in the in vivo challenge test than the carp fish. The analysis of aer gene sequence from challenged fish revealed significant sequence divergence according to the types and geographical distribution of the fish. The networking analysis of aer from the model A. veronii B565 revealed histidine kinase (cheA) as the most functional interacting partner. The study of the interaction between aer from the experimental A. veronii and cheA demonstrated that the A chain of cheA plays a more important role than the corresponding B chain during contact, and a linker sequence of 15 residues controlled the entire interaction process. Therefore, cheA could be an excellent drug target for controlling A. veronii infection of fish.
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Affiliation(s)
- Md Javed Foysal
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
- Department of Genetic Engineering and Biotechnology, Shahjalal University of Science and Technology, Sylhet, Bangladesh
| | - Farhana Momtaz
- Department of Microbiology, Chittagong University, Chittagong, Bangladesh
| | - Md Hazrat Ali
- Department of Genetic Engineering and Biotechnology, Shahjalal University of Science and Technology, Sylhet, Bangladesh
| | - Muhammad A B Siddik
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Md Reaz Chaklader
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Md Mahbubur Rahman
- Department of Biotechnology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Md Shamsul Haque Prodhan
- Department of Genetic Engineering and Biotechnology, Shahjalal University of Science and Technology, Sylhet, Bangladesh
| | - Anthony Cole
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
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Sundaram E, Kathiravan S, Manna A, Chinnaiah A, Vasantha V. Designing of New Optical Immunosensors Based on 2-Amino-4-(anthracen-9-yl)-7-hydroxy-4 H-chromene-3-carbonitrile for the Detection of Aeromonas hydrophila in the Organs of Oreochromis mossambicus Fingerlings. ACS OMEGA 2019; 4:4814-4824. [PMID: 31459665 PMCID: PMC6648643 DOI: 10.1021/acsomega.8b02467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/14/2019] [Indexed: 05/27/2023]
Abstract
A one-pot greener methodology has been adopted for the synthesis of a simple 4H-chromene core-based fluorescent tag of (S)-2-amino-4-(anthracen-9-yl)-7-hydroxy-4H-chromene-3-carbonitrile (AHC), and its structure has been analyzed using NMR spectroscopy. The physicochemical properties of AHC were well-studied by UV-vis and fluorescent spectroscopy techniques. As a result of excellent emitting property (ϕ ≈ 0.75), it has been coupled with anti-AH through amide linkage, and the AHC-tagged anti-AH has been used as an immunoassay for the selective detection of Aeromonas hydrophila in the presence of interfering pathogens. Under optimized conditions, immunosensors could successfully quantify A. hydrophila from 4 to 736 CFU/mL, and the LOD was 2 CFU/mL. Saliently, the immunoassay has been successfully demonstrated for the analysis of A. hydrophila in the organs of Oreochromis mossambicusfingerlings, and results have shown a very good agreement with our optimized neat AH fluorimetric titration results.
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Affiliation(s)
- Ellairaja Sundaram
- Department
of Natural Products Chemistry, School of Chemistry, and Department of
Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - Shenbagavalli Kathiravan
- Department
of Natural Products Chemistry, School of Chemistry, and Department of
Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - Abhijit Manna
- Department
of Natural Products Chemistry, School of Chemistry, and Department of
Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - Amutha Chinnaiah
- Department
of Natural Products Chemistry, School of Chemistry, and Department of
Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
| | - VairathevarSivasamy Vasantha
- Department
of Natural Products Chemistry, School of Chemistry, and Department of
Animal Behaviour and Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India
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Subramani PA, Narasimha RV, Balasubramanian R, Narala VR, Ganesh MR, Michael RD. Cytotoxic effects of Aeromonas hydrophila culture supernatant on peripheral blood leukocytes of Nile tilapia (Oreochromis niloticus): Possible presence of a secreted cytotoxic lectin. FISH & SHELLFISH IMMUNOLOGY 2016; 58:604-611. [PMID: 27702674 DOI: 10.1016/j.fsi.2016.09.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/26/2016] [Accepted: 09/30/2016] [Indexed: 06/06/2023]
Abstract
Number of exotoxins like haemolysin, leukocidin, aerolysin etc. were reported from Aeromonas hydrophila. In this study, we report the haemolytic and cytotoxic effect of A. hydrophila culture supernatant (CS) that is specifically inhibited by lactose and also by serum and mucus of Nile tilapia (Oreochromis niloticus). Hence, we assume the presence of a secreted lectin in the CS. CS is toxic to peripheral blood leukocytes (PBL) of O. niloticus as revealed by MTT assay and by flow cytometry. DNA laddering assay indicates that CS causes necrosis to PBL. As a result of necrosis, CS treated PBL showed increased production of reactive oxygen species as indicated by nitroblue tetrazolium and 2',7' -dichlorofluorescin diacetate assays. CS treated PBL showed reduced mRNA expression of TNF-α and IFN-γ genes. When CS was subjected to polyacrylamide gel electrophoresis, it showed a single band corresponding to the molecular weight of 45 kDa. However, upon concentrating the CS by ultrafiltration, many bands were visualized. Further studies at molecular level are required to unravel this macromolecular-leukocyte interaction which would ultimately benefit the aquaculture industry.
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Affiliation(s)
- Parasuraman Aiya Subramani
- Centre for Fish Immunology, Vels Institute of Science, Technology, and Advanced Studies (VISTAS), Pallavaram, Chennai, 600117, India
| | | | - Ramalakshmi Balasubramanian
- Centre for Fish Immunology, Vels Institute of Science, Technology, and Advanced Studies (VISTAS), Pallavaram, Chennai, 600117, India
| | | | - M R Ganesh
- Interdisciplinary Institute of Indian System of Medicine, SRM University, Kattankulathur, 603203, India
| | - R Dinakaran Michael
- Centre for Fish Immunology, Vels Institute of Science, Technology, and Advanced Studies (VISTAS), Pallavaram, Chennai, 600117, India.
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6
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Yu H, Wang MJ, Xuan NX, Shang ZC, Wu J. Molecular dynamics simulation of the interactions between EHD1 EH domain and multiple peptides. J Zhejiang Univ Sci B 2016; 16:883-96. [PMID: 26465136 DOI: 10.1631/jzus.b1500106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated. METHODS Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software. RESULTS The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the structural basis of contributions of van der Waals interactions of the flanking residues to the binding. CONCLUSIONS van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues.
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Affiliation(s)
- Hua Yu
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Mao-jun Wang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Nan-xia Xuan
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Zhi-cai Shang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Jun Wu
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
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7
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Patel B, Kumar P, Banerjee R, Basu M, Pal A, Samanta M, Das S. Lactobacillus acidophilus attenuates Aeromonas hydrophila induced cytotoxicity in catla thymus macrophages by modulating oxidative stress and inflammation. Mol Immunol 2016; 75:69-83. [PMID: 27262084 DOI: 10.1016/j.molimm.2016.05.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/16/2016] [Accepted: 05/16/2016] [Indexed: 01/16/2023]
Abstract
The pathogenesis of Aeromonas hydrophila, a potent fish pathogen, is attributed to its ability to cause motile aeromonad septicaemia leading to apoptosis in a myriad of fish species, including freshwater carp Catla catla. However, the underlying mechanism of antagonistic activity of probiotics against A. hydrophila induced apoptosis is not elucidated due to lack of appropriate in-vitro models. This study reported that the exposure of catla thymus macrophages (CTM) to A. hydrophila markedly induced cellular injuries as evidenced by elevated levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), increased apoptosis, DNA damage and decreased cellular viability. Flow cytometry analysis and Annexin-V/propidium iodide assay further confirmed increased ROS positive cells leading to cell death after infection. The quantitative real-time PCR analysis, also revealed upregulation of inducible nitric-oxide synthase (iNOS), pro-inflammatory cytokine (TNFα), cyclooxygenase2 (COX-2) and downregulation of anti-inflammatory cytokine (IL-10). Pretreatment of cells with probiotic, Lactobacillus acidophilus attenuated A. hydrophila induced apoptosis as evident from the decrease in the levels of ROS, RNS and DNA damage. Significant increase (P≤0.05) in expression of TNFα and IL-10 and decrease in iNOS and COX-2 was observed on probiotic stimulation. In-vivo study using catla fingerlings confirmed similar pattern of ROS, iNOS, NO production and cytokine expression in thymus. This study provides a comprehensive insight into the mechanistic basis of L. acidophilus induced macrophage mediated inflammatory response against A. hydrophila in CTM cells. Further, it speculates the possibility of using cost-effective in-vitro models for screening probiotic candidates of therapeutic potential in aquaculture industry.
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Affiliation(s)
- Bhakti Patel
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Premranjan Kumar
- School of Biotechnology, KIIT University, Bhubaneswar, 751024, Odisha, India
| | - Rajanya Banerjee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Madhubanti Basu
- Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyanga, Bhubaneswar, 751002, Odisha, India
| | - Arttatrana Pal
- School of Biotechnology, KIIT University, Bhubaneswar, 751024, Odisha, India
| | - Mrinal Samanta
- Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyanga, Bhubaneswar, 751002, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
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Banerjee C, Singh A, Das TK, Raman R, Shrivastava A, Mazumder S. Ameliorating ER-stress attenuates Aeromonas hydrophila-induced mitochondrial dysfunctioning and caspase mediated HKM apoptosis in Clarias batrachus. Sci Rep 2014; 4:5820. [PMID: 25059203 PMCID: PMC5376045 DOI: 10.1038/srep05820] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 06/16/2014] [Indexed: 02/07/2023] Open
Abstract
Endoplasmic reticulum (ER)-stress and unfolding protein response (UPR) has not been implied in Aeromonas hydrophila-pathogenicity. We report increased expression of the ER-stress markers: CHOP, BiP and phospho-eIF2α in A. hydrophila-infected headkidney macrophages (HKM) in Clarias batrachus. Pre-treatment with ER-stress inhibitor, 4-PBA alleviated ER-stress and HKM apoptosis suggesting ER-UPR critical for the process. The ER-Ca(2+) released via inositol-triphosphate and ryanodine receptors induced calpain-2 mediated superoxide ion generation and consequent NF-κB activation. Inhibiting NF-κB activation attenuated NO production suggesting the pro-apoptotic role of NF-κB on HKM pathology. Calpain-2 activated caspase-12 to intensify the apoptotic cascade through mitochondrial-membrane potential (ψm) dissipation and caspase-9 activation. Altered mitochondrial ultra-structure consequent to ER-Ca(2+) uptake via uniporters reduced ψm and released cytochrome C. Nitric oxide induced the cGMP/PKG-dependent activation of caspase-8 and truncated-Bid formation. Both the caspases converge onto caspase-3 to execute HKM apoptosis. These findings offer a possible molecular explanation for A. hydrophila pathogenicity.
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Affiliation(s)
- Chaitali Banerjee
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Ambika Singh
- Gut Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Taposh Kumar Das
- Department of Anatomy, All India Institute of Medical Sciences, Delhi 110 029, India
| | - Rajagopal Raman
- Gut Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Anju Shrivastava
- Cell Signalling and Molecular Immunology Laboratory, Department of Zoology, University of Delhi, Delhi 110 007, India
| | - Shibnath Mazumder
- Immunobiology Laboratory, Department of Zoology, University of Delhi, Delhi 110 007, India
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Hesperidin inhibits inflammatory response induced by Aeromonas hydrophila infection and alters CD4+/CD8+ T cell ratio. Mediators Inflamm 2014; 2014:393217. [PMID: 24891765 PMCID: PMC4033591 DOI: 10.1155/2014/393217] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 03/21/2014] [Indexed: 12/26/2022] Open
Abstract
Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES) has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4+/CD8+ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4+ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8+ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4+/CD8+ cell ratio.
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Rosenzweig JA, Chopra AK. Modulation of host immune defenses by Aeromonas and Yersinia species: convergence on toxins secreted by various secretion systems. Front Cell Infect Microbiol 2013; 3:70. [PMID: 24199174 PMCID: PMC3812659 DOI: 10.3389/fcimb.2013.00070] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/14/2013] [Indexed: 12/20/2022] Open
Abstract
Like other pathogenic bacteria, Yersinia and Aeromonas species have been continuously co-evolving with their respective hosts. Although the former is a bonafide human pathogen, the latter has gained notararity as an emerging disease-causing agent. In response to immune cell challenges, bacterial pathogens have developed diverse mechanism(s) enabling their survival, and, at times, dominance over various host immune defense systems. The bacterial type three secretion system (T3SS) is evolutionarily derived from flagellar subunits and serves as a vehicle by which microbes can directly inject/translocate anti-host factors/effector proteins into targeted host immune cells. A large number of Gram-negative bacterial pathogens possess a T3SS empowering them to disrupt host cell signaling, actin cytoskeleton re-arrangements, and even to induce host-cell apoptotic and pyroptotic pathways. All pathogenic yersiniae and most Aeromonas species possess a T3SS, but they also possess T2- and T6-secreted toxins/effector proteins. This review will focus on the mechanisms by which the T3SS effectors Yersinia outer membrane protein J (YopJ) and an Aeromonas hydrophila AexU protein, isolated from the diarrheal isolate SSU, mollify host immune system defenses. Additionally, the mechanisms that are associated with host cell apoptosis/pyroptosis by Aeromonas T2SS secreted Act, a cytotoxic enterotoxin, and Hemolysin co-regulated protein (Hcp), an A. hydrophila T6SS effector, will also be discussed.
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Affiliation(s)
- Jason A Rosenzweig
- Department of Biology, Center for Bionanotechnology and Environmental Research, Texas Southern University Houston, TX, USA ; Department of Environmental and Interdisciplinary Sciences, Texas Southern University Houston, TX, USA
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Igbinosa IH, Igumbor EU, Aghdasi F, Tom M, Okoh AI. Emerging Aeromonas species infections and their significance in public health. ScientificWorldJournal 2012; 2012:625023. [PMID: 22701365 PMCID: PMC3373137 DOI: 10.1100/2012/625023] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 03/20/2012] [Indexed: 12/28/2022] Open
Abstract
Aeromonas species are ubiquitous bacteria in terrestrial and aquatic milieus. They are becoming renowned as enteric pathogens of serious public health concern as they acquire a number of virulence determinants that are linked with human diseases, such as gastroenteritis, soft-tissue, muscle infections, septicemia, and skin diseases. Proper sanitary procedures are essential in the prevention of the spread of Aeromonas infections. Oral fluid electrolyte substitution is employed in the prevention of dehydration, and broad-spectrum antibiotics are used in severe Aeromonas outbreaks. This review presents an overview of emerging Aeromonas infections and proposes the need for actions necessary for establishing adequate prevention measures against the infections.
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Affiliation(s)
- Isoken H. Igbinosa
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Ehimario U. Igumbor
- School of Public Health, University of the Western Cape, Bellville 7535, Cape Town, South Africa
| | - Farhad Aghdasi
- Risk and Vulnerability Assessment Centre, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Mvuyo Tom
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Anthony I. Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
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12
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Cantas L, Midtlyng PJ, Sørum H. Impact of antibiotic treatments on the expression of the R plasmid tra genes and on the host innate immune activity during pRAS1 bearing Aeromonas hydrophila infection in zebrafish (Danio rerio). BMC Microbiol 2012; 12:37. [PMID: 22429905 PMCID: PMC3340321 DOI: 10.1186/1471-2180-12-37] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 03/19/2012] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The transfer of R plasmids between bacteria has been well studied under laboratory conditions and the transfer frequency has been found to vary between plasmids and under various physical conditions. For the first time, we here study the expression of the selected plasmid mobility genes traD, virB11 and virD4 in the 45 kb IncU plasmid, pRAS1, conferring resistance to tetracycline, trimethoprim and sulphonamide, using an in vivo zebrafish infection- treatment model. RESULTS Three days after oral infection of adult zebrafish with Aeromonas hydrophila harboring pRAS1, elevated expression of pro-inflammatory cytokine (TNF α, IL-1β and IL-8) and complement C3 genes in the intestine coincided with disease symptoms. Tetracycline, trimethoprim and an ineffective concentration of flumequine given 48 h prior to sampling, strongly increased expression of plasmid mobility genes, whereas an effective dosage of flumequine resulted in lower levels of mRNA copies of these genes relative to placebo treatment. Following effective treatment with flumequine, and ineffective treatments with a low concentration of flumequine, with trimethoprim or with sulphonamide, the intestinal expression of immune genes was strongly induced compared to placebo treated control fish. CONCLUSIONS Treatment of zebrafish infected with an antibiotic resistant (TcR, TmR, SuR) A. hydrophila with ineffective concentrations of flumequine or the ineffective antimicrobials tetracycline and trimethoprim strongly induced expression of genes mediating conjugative transfer of the R-plasmid pRAS1. Simultaneously, there was a strong induction of selected inflammatory and immune response genes, which was again evident in fish subjected to ineffective treatment protocols. Our findings point to the essential role of therapeutic practices in escalation or control of antibiotic resistance transfer, and suggest that antibiotic substances, even in sub-inhibitory concentrations, may stimulate innate defenses against bacterial infections.
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Affiliation(s)
- Leon Cantas
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Ullevålsveien 72, PO 8146, 0033 Oslo, Norway.
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Popoff MR. Multifaceted interactions of bacterial toxins with the gastrointestinal mucosa. Future Microbiol 2011; 6:763-97. [PMID: 21797691 DOI: 10.2217/fmb.11.58] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The digestive tract is one of the ecosystems that harbors the largest number and greatest variety of bacteria. Among them, certain bacteria have developed various strategies, including the synthesis of virulence factors such as toxins, to interact with the intestinal mucosa, and are responsible for various pathologies. A large variety of bacterial toxins of different sizes, structures and modes of action are able to interact with the gastrointestinal mucosa. Some toxins, termed enterotoxins, directly stimulate fluid secretion in enterocytes or cause their death, whereas other toxins pass through the intestinal barrier and disseminate by the general circulation to remote organs or tissues, where they are active. After recognition of a membrane receptor on target cells, toxins can act at the cell membrane by transducing a signal across the membrane in a hormone-like manner, by pore formation or by damaging membrane compounds. Other toxins can enter the cells and modify an intracellular target leading to a disregulation of certain physiological processes or disorganization of some structural architectures and cell death. Toxins are fascinating molecules, which mimic or interfere with eukaryotic physiological processes. Thereby, they have permitted the identification and characterization of new natural hormones or regulatory pathways. Besides use as protective antigens in vaccines, toxins offer multiple possibilities in pharmacology, such as immune modulation or specific delivery of a protein of interest into target cells.
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Affiliation(s)
- M R Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, 25 rue du Dr Roux, 757245 Paris cedex 15, France.
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Zhou Z, He S, Liu Y, Cao Y, Meng K, Yao B, Ringø E, Yoon I. Gut microbial status induced by antibiotic growth promoter alters the prebiotic effects of dietary DVAQUA® on Aeromonas hydrophila-infected tilapia: Production, intestinal bacterial community and non-specific immunity. Vet Microbiol 2011; 149:399-405. [DOI: 10.1016/j.vetmic.2010.11.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 11/11/2010] [Accepted: 11/12/2010] [Indexed: 12/16/2022]
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EHD proteins: key conductors of endocytic transport. Trends Cell Biol 2010; 21:122-31. [PMID: 21067929 DOI: 10.1016/j.tcb.2010.10.003] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/07/2010] [Accepted: 10/07/2010] [Indexed: 12/12/2022]
Abstract
Regulation of endocytic transport is controlled by an elaborate network of proteins. Rab GTP-binding proteins and their effectors have well-defined roles in mediating specific endocytic transport steps, but until recently less was known about the four mammalian dynamin-like C-terminal Eps15 homology domain (EHD) proteins that also regulate endocytic events. In recent years, however, great strides have been made in understanding the structure and function of these unique proteins. Indeed, a growing body of literature addresses EHD protein structure, interactions with binding partners, functions in mammalian cells, and the generation of various new model systems. Accordingly, this is now an opportune time to pause and review the function and mechanisms of action of EHD proteins, and to highlight some of the challenges and future directions for the field.
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McCoy AJ, Koizumi Y, Toma C, Higa N, Dixit V, Taniguchi S, Tschopp J, Suzuki T. Cytotoxins of the human pathogen Aeromonas hydrophila trigger, via the NLRP3 inflammasome, caspase-1 activation in macrophages. Eur J Immunol 2010; 40:2797-803. [DOI: 10.1002/eji.201040490] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Rodríguez I, Chamorro R, Novoa B, Figueras A. beta-Glucan administration enhances disease resistance and some innate immune responses in zebrafish (Danio rerio). FISH & SHELLFISH IMMUNOLOGY 2009; 27:369-373. [PMID: 19232393 DOI: 10.1016/j.fsi.2009.02.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 01/15/2009] [Accepted: 02/01/2009] [Indexed: 05/27/2023]
Abstract
The present study was conducted to investigate the effect of beta-glucan (derived from Saccharomyces cerevisiae) on the immune response and its protection against an infection of the bacterial pathogen Aeromonas hydrophila in zebrafish (Danio rerio). Zebrafish received beta-glucan by intraperitoneal injection at three different concentrations (5, 2 and 0.5 mgml(-1)) at 6, 4 and 2 days prior the challenge. On challenge day the control and beta-glucan pretreated zebrafish were intraperitoneally injected with A. hydrophila and mortality was recorded for 4 days. Intraperitoneal injection of 5 mgml(-1) of beta-glucan significantly reduced the mortality. A single injection of 5 mgml(-1) of beta-glucan 6 days before challenge also enhanced significantly the survival against the infection. The treatment with beta-glucan increased the myelomonocytic cell population in the kidney at 6h postchallenge with A. hydrophila. Moreover it enhanced the ability of kidney cells to kill A. hydrophila. beta-glucan did not affect the expression of TNFalpha or IL-1 beta but seemed to modulate IFNgamma and chemokine expression in kidney.
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Affiliation(s)
- Iván Rodríguez
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello 6, Vigo, Spain
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MacCarthy EM, Burns I, Irnazarow I, Polwart A, Greenhough TJ, Shrive AK, Hoole D. Serum CRP-like protein profile in common carp Cyprinus carpio challenged with Aeromonas hydrophila and Escherichia coli lipopolysaccharide. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:1281-1289. [PMID: 18538390 DOI: 10.1016/j.dci.2008.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 03/17/2008] [Accepted: 04/06/2008] [Indexed: 05/26/2023]
Abstract
The potential of C-reactive protein (CRP)-like proteins to be used as a biomarker of health status in cultured carp obtained from various European fish lines has been assessed. Varying CRP-like protein levels in the serum of carp were monitored using an indirect competitive enzyme-linked immunosorbent assay. CRP-like protein basal levels in normal fish varied between carp lines, ranging on average from 2.9+/-0.15 to 12.57+/-1.19 microg ml(-1). Serum levels of CRP-like protein in carp were observed to increase several fold in fish infected with the pathogen Aeromonas hydrophila. However, carp injected with Escherichia coli lipopolysaccharide (LPS) serotype 0111:B4 did not exhibit an increase in CRP-like proteins levels.
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Affiliation(s)
- Eugene M MacCarthy
- School of Life Sciences, Huxley Building, Keele University, Staffordshire ST5 5BG, UK
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19
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Suarez G, Sierra JC, Sha J, Wang S, Erova TE, Fadl AA, Foltz SM, Horneman AJ, Chopra AK. Molecular characterization of a functional type VI secretion system from a clinical isolate of Aeromonas hydrophila. Microb Pathog 2007; 44:344-61. [PMID: 18037263 DOI: 10.1016/j.micpath.2007.10.005] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 10/17/2007] [Accepted: 10/18/2007] [Indexed: 01/01/2023]
Abstract
Our laboratory recently molecularly characterized the type II secretion system (T2SS)-associated cytotoxic enterotoxin (Act) and the T3SS-secreted AexU effector from a diarrheal isolate SSU of Aeromonas hydrophila. The role of these toxin proteins in the pathogenesis of A. hydrophila infections was subsequently delineated in in vitro and in vivo models. In this study, we characterized the new type VI secretion system (T6SS) from isolate SSU of A. hydrophila and demonstrated its role in bacterial virulence. Study of the role of T6SS in bacterial virulence is in its infancy, and there are, accordingly, only limited, recent reports directed toward a better understanding its role in bacterial pathogenesis. We have provided evidence that the virulence-associated secretion (vas) genes vasH (Sigma 54-dependent transcriptional regulator) and vasK (encoding protein of unknown function) are essential for expression of the genes encoding the T6SS and/or they constituted important components of the T6SS. Deletion of the vasH gene prevented expression of the potential translocon hemolysin coregulated protein (Hcp) encoding gene from bacteria, while the vasK gene deletion prevented secretion but not translocation of Hcp into host cells. The secretion of Hcp was independent of the T3SS and the flagellar system. We demonstrated that secreted Hcp could bind to the murine RAW 264.7 macrophages from outside, in addition to its ability to be translocated into host cells. Further, the vasH and vasK mutants were less toxic to murine macrophages and human epithelial HeLa cells, and these mutants were more efficiently phagocytosed by macrophages. We also provided evidence that the expression of the hcp gene in the HeLa cell resulted in apoptosis of the host cells. Finally, the vasH and vasK mutants of A. hydrophila were less virulent in a septicemic mouse model of infection, and animals immunized with recombinant Hcp were protected from subsequent challenge with the wild-type (WT) bacterium. In addition, mice infected with the WT A. hydrophila had circulating antibodies to Hcp, indicating an important role of T6SS in the pathogenesis of A. hydrophila infections. Taken together, we have characterized the T6SS from Aeromonas for the first time and provided new features of this secretion system not yet known for other pathogens.
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Affiliation(s)
- Giovanni Suarez
- Department of Microbiology and Immunology(,) University of Texas Medical Branch, 301 University Blvd., Galveston, TX 775551070, USA
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Sierra JC, Suarez G, Sha J, Foltz SM, Popov VL, Galindo CL, Garner HR, Chopra AK. Biological characterization of a new type III secretion system effector from a clinical isolate of Aeromonas hydrophila-part II. Microb Pathog 2007; 43:147-60. [PMID: 17582731 DOI: 10.1016/j.micpath.2007.05.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We recently identified a novel type III secretion system (T3SS) effector, AexU, from a diarrheal isolate SSU of Aeromonas hydrophila, and demonstrated that mice infected with the DeltaaexU mutant were significantly protected from mortality. Although the NH(2)-terminal domain of this toxin exhibits homology to AexT of A. salmonicida, a fish pathogen, and ExoT/S of Pseudomonas aeruginosa, the COOH-terminal domain of AexU is unique, with no homology to any known proteins in the NCBI database. In this study, we purified the full-length AexU and its NH(2)-terminal (amino acid residues 1-231) and COOH-terminal (amino acid residues 232-512) domains after expression of their corresponding genes in Escherichia coli as histidine-tag fusion proteins using the bacteriophage T7 RNA polymerase/promoter-based pET-30a vector system. The full-length and NH(2)- and COOH-terminal domains of AexU exhibited ADP-ribosyltransferase activity, with the former two exhibiting much higher activity than the latter. These different forms of AexU were also successfully expressed and produced in the HeLa Tet-Off cell system using a pBI-EGFP vector, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot analysis, and intracellular staining of the toxin using flow cytometric analysis. Production of AexU in HeLa cells resulted in possible actin reorganization and cell rounding, as determined by phalloidin staining and confocal microscopy. Based on electron microscopy, the toxin also caused chromatin condensation, which is indicative of apoptosis. Apoptosis of HeLa cells expressing and producing AexU was confirmed by 7-amino actinomycin D (7-AAD) and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] assays, by detection of cytoplasmic histone-associated DNA fragments, and by activation of caspases 3 and 9. These effects were much more pronounced in host cells that expressed and produced the full-length or NH(2)-terminal domain of AexU, compared to those that expressed and produced the COOH-terminal domain or the vector alone. This study represents the first characterization of this novel T3SS effector.
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Affiliation(s)
- Johanna C Sierra
- Department of Microbiology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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Fadl AA, Galindo CL, Sha J, Zhang F, Garner HR, Wang HQ, Chopra AK. Global transcriptional responses of wild-type Aeromonas hydrophila and its virulence-deficient mutant in a murine model of infection. Microb Pathog 2007; 42:193-203. [PMID: 17368824 DOI: 10.1016/j.micpath.2007.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 12/12/2006] [Accepted: 02/02/2007] [Indexed: 11/25/2022]
Abstract
We previously generated a double knockout mutant (act/aopB) of a diarrheal isolate SSU of A. hydrophila, in which the genes encoding Aeromonas outer membrane protein B (AopB), a structural component of the type III secretion system (T3SS), and a type II (T2)-secreted cytotoxic enterotoxin gene (act) were deleted. This mutant exhibited minimal virulence in mice, compared to animals infected with wild-type (WT) A. hydrophila. Based on microarray analyses, WT A. hydrophila altered the expression of 434 and 80 genes in murine macrophages (RAW 264.7) and human colonic epithelial cells (HT-29), respectively. Approximately half of these gene expression alterations were abrogated when host cells were infected instead with the act/aopB mutant. In this study, we used microarrays to examine early host transcriptional responses in spleens of mice infected for 3h with WT A. hydrophila or its act/aopB mutant. Our data indicated that expression of 221 genes was altered (158 up-regulated and 63 down-regulated) in spleens of WT bacteria-infected animals. There were 21 genes that were consistently more highly expressed in WT A. hydrophila-infected mice, compared to mice infected with its act/aopB mutant. Ten of these genes were either induced to a lesser extent (e.g., interleukin-6, macrophage inflammatory protein-2, and cyclooxygenase-2), not altered at all (e.g., killer cell lectin-like receptor subfamily B member A), or down-regulated (e.g., cytochrome P450) in animals infected with A. hydrophila, compared to phosphate-buffered saline-infected control animals, when the mutant was used instead of the WT. We verified the microarray results at the transcript level by performing real-time reverse transcriptase-polymerase chain reaction on selected genes and at the protein level by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. This is the first study demonstrating in vivo gene regulation in mice infected with A. hydrophila and the contribution of virulence factors and host responses to the disease process.
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Affiliation(s)
- Amin A Fadl
- Department of Microbiology and Immunology, Medical Research Building, 301 University Boulevard, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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22
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Comer JE, Galindo CL, Zhang F, Wenglikowski AM, Bush KL, Garner HR, Peterson JW, Chopra AK. Murine macrophage transcriptional and functional responses to Bacillus anthracis edema toxin. Microb Pathog 2006; 41:96-110. [PMID: 16846716 DOI: 10.1016/j.micpath.2006.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 05/02/2006] [Accepted: 05/02/2006] [Indexed: 01/29/2023]
Abstract
Edema toxin (EdTx), which is a combination of edema factor and a binding moiety (protective antigen), is produced by Bacillus anthracis, the etiological agent of anthrax. EdTx is an adenylyl cyclase enzyme that converts adenosine triphosphate to adenosine-3',5'-monophosphate, resulting in interstitial edema seen in anthrax patients. We used GeneChip analysis to examine global transcriptional profiles of EdTx-treated RAW 264.7 murine macrophage-like cells and identified 71 and 259 genes whose expression was significantly altered by the toxin at 3 and 6h, respectively. Alteration in the expression levels of selected genes was confirmed by real time-reverse transcriptase polymerase chain reaction. The genes with up-regulated expression in macrophages in response to EdTx-treatment were known to be involved in inflammatory responses, regulation of apoptosis, adhesion, immune cell activation, and transcription regulation. Additionally, GeneChip analysis results implied that EdTx-induced activation of activator protein-1 (AP-1) and CAAAT/enhancer-binding protein-beta (C/EBP-beta). Gel shift assays were therefore performed, and an increase in the activities of both of these transcription factors was observed within 30 min. EdTx also inhibited tumor necrosis factor alpha production and crippled the phagocytic ability of the macrophages. This is the first report detailing the host cell global transcriptional responses to EdTx.
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Affiliation(s)
- Jason E Comer
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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Chopra V, Fadl AA, Sha J, Chopra S, Galindo CL, Chopra AK. Alterations in the virulence potential of enteric pathogens and bacterial-host cell interactions under simulated microgravity conditions. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2006; 69:1345-70. [PMID: 16760141 DOI: 10.1080/15287390500361792] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Host immune mechanisms were proposed to decline under microgravity conditions during spaceflights, which might result in severe infections in astronauts. Therefore, it was important to investigate the effects of microgravity on infecting organisms and their interaction with host cells. Data showed that simulated microgravity (SMG) conditions markedly increased production of the enterotoxigenic Escherichia coli (ETEC) heat-labile enterotoxin, which induced fluid secretory responses in a mouse model. SMG also enhanced production of tumor necrosis factor-alpha in murine macrophages infected with enteropathogenic E. coli (EPEC). In a similar fashion, simulated microgravity conditions augmented the invasive potential of Salmonella enterica serovar typhimurium and enhanced production of tumor necrosis-factor alpha in S. typhimurium-infected epithelial cells. Furthermore, coculturing of macrophages and S. typhimurium in a simulated microgravity environment resulted in activation of stress-associated mitogen-activated protein kinase kinase 4. Using the antiorthostatic tail suspension mouse model, which simulates some aspects of microgravity, oral inoculation of S. typhimurium markedly reduced the 50% lethal dose compared to mice infected under normal gravitational conditions. Microarray analysis revealed simulated microgravity-induced alterations in the expression of 22 genes in S. typhimurium, and protein expression profiles were altered in both EPEC and S. typhimurium, based on two-dimensional gel electrophoresis. These studies indicated alterations in the virulence potential of bacteria and in host responses to these pathogens under simulated microgravity conditions, which may represent an important environmental signal. Such studies are essential for better understanding bacterial-host cell interactions, particularly in the context of spaceflights and space habitations of long duration.
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Affiliation(s)
- V Chopra
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas 77555-1070, USA
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Fadl AA, Galindo CL, Sha J, Erova TE, Houston CW, Olano JP, Chopra AK. Deletion of the genes encoding the type III secretion system and cytotoxic enterotoxin alters host responses to Aeromonas hydrophila infection. Microb Pathog 2006; 40:198-210. [PMID: 16626931 DOI: 10.1016/j.micpath.2006.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/09/2006] [Accepted: 01/16/2006] [Indexed: 12/21/2022]
Abstract
In our previous study, we deleted the gene encoding Aeromonas outer membrane protein B (AopB), a structural component of the type III secretion system (T3SS) from a cytotoxic enterotoxin gene (act)-minus diarrheal isolate SSU of Aeromonas hydrophila. Our laboratory also molecularly characterized the cytotoxic enterotoxin (Act), which is secreted by the bacterium utilizing the type II secretion system (T2SS). The act/aopB mutant exhibited significantly reduced cytotoxicity to cultured cells (e.g. RAW 264.7 murine macrophages and HT-29 human colonic epithelial cells) and was avirulent in mice. In this study, we developed additional A. hydrophila mutants in which T3SS-associated ascV and acrV genes were deleted, either individually or in combination with that of the act gene, to examine host-pathogen interactions. A significant reduction in the induction of inflammatory cytokines and chemokines was noted in the sera of mice infected with these mutants when compared to animals infected with wild-type (WT) A. hydrophila. After infection with the WT and act/aopB mutant, we performed microarray analyses on RNA from the above-mentioned murine macrophages and human colonic epithelial cells to examine global cellular transcriptional responses. Based on three independent experiments, WT A. hydrophila altered the expression of 434 genes in RAW 264.7 cells and 80 genes in HT-29 cells. Alteration in the expression of 209 macrophage and 32 epithelial cell genes was reduced when the act/aopB mutant was used, compared to when cells were infected with the WT bacterium, indicating the involvement of Act and/or AopB in transcriptional regulation of these genes. We verified up-regulation of 15 genes by real-time reverse transcriptase-polymerase chain reaction and confirmed A. hydrophila WT-versus mutant-induced production of cytokines/chemokines in supernatants from RAW 264.7 and HT-29 cells. This is the first description of host cell transcriptional responses to A. hydrophila infection.
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Affiliation(s)
- Amin A Fadl
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Medical Research Building, 301 University Boulevard, Galveston, TX 77555-1070, USA
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Fadl AA, Galindo CL, Sha J, Klimpel GR, Popov VL, Chopra AK. Global gene expression of a murein (Braun) lipoprotein mutant of Salmonella enterica serovar Typhimurium by microarray analysis. Gene 2006; 374:121-7. [PMID: 16574345 DOI: 10.1016/j.gene.2006.01.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 01/23/2006] [Accepted: 01/25/2006] [Indexed: 12/15/2022]
Abstract
Braun/murein lipoprotein (Lpp) is one of the major outer membrane components of gram-negative enteric bacteria involved in inflammatory responses and septic shock. In previous studies, we reported that two copies of the lipoprotein (lpp) gene (designated as lppA and lppB) existed on the chromosome of Salmonella enterica serovar Typhimurium. Deletion of both lppA and lppB genes rendered Salmonella defective in invasion, motility, induction of cytotoxicity, and production of inflammatory cytokines/chemokines. The lppAB double-knockout (DKO) mutant was attenuated in mice, and animals immunized with this mutant were protected against subsequent challenge with lethal doses of wild-type (wt) S. Typhimurium. To better understand how deletion of the lpp gene might affect Salmonella virulence, we performed global transcriptional profiling of the genes in the wt and the lppAB DKO mutant of S. Typhimurium using microarrays. Our data revealed alterations in the expression of flagellar genes, invasion-associated type III secretion system genes, and transcriptional virulence gene regulators in the lppAB DKO mutant compared to wt S. Typhimurium. These data correlated with the lppAB DKO mutant phenotype and provided possible mechanism(s) of Lpp-associated attenuation in S. Typhimurium. Although these studies were performed in in vitro grown bacteria, our future research will be targeted at global transcriptional profiling of the genes in in vivo grown wt S. Typhimurium and its Lpp mutant.
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Affiliation(s)
- A A Fadl
- Department of Microbiology and Immunology, 301 University Blvd, University of Texas Medical Branch, Galveston, Texas 77555-1070, United States
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Desnues B, Ihrig M, Raoult D, Mege JL. Whipple's disease: a macrophage disease. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 13:170-8. [PMID: 16467322 PMCID: PMC1391942 DOI: 10.1128/cvi.13.2.170-178.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Benoît Desnues
- Unité des Rickettsies, Centre National de la Recherche Scientifique, Institut Fédératif de Recherche, Université de la Méditerranée, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 5, France
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Galindo CL, Gutierrez C, Chopra AK. Potential involvement of galectin-3 and SNAP23 in Aeromonas hydrophila cytotoxic enterotoxin-induced host cell apoptosis. Microb Pathog 2006; 40:56-68. [PMID: 16426811 DOI: 10.1016/j.micpath.2005.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 11/03/2005] [Accepted: 11/07/2005] [Indexed: 11/23/2022]
Abstract
We investigated the potential of the cytotoxic enterotoxin (Act) of Aeromonas hydrophila to bind to 1869 human and 4319 yeast proteins, using protein microarray technology. Act was capable of binding nine different human proteins, including the SNARE complex scaffolding protein synaptosomal-associated protein 23 (SNAP23), galectin-3, and guanylate kinase 1 (GUK-1). Act was also able to bind to four of the yeast proteins examined, which included the vesicle tethering protein Vsp52. We verified interaction of Act with murine and human SNAP23, galectin-3, and GUK-1 by sandwich Western blot analysis. In order to determine the physiological relevance of Act binding to these three proteins, we performed small interfering RNA (siRNA) gene knockdown experiments in RAW 264.7 cells, a murine macrophage cell line in which Act-induced signaling and cell death is well characterized. Based on real-time reverse transcriptase-polymerase chain reaction, siRNA transfection of RAW 264.7 cells with specific oligonucleotides reduced the expression of genes encoding SNAP23, galectin-3, and GUK-1 by 62, 63, and 99%, respectively. Knockdown of galectin-3 and SNAP23, but not GUK-1, significantly reduced Act-induced apoptosis of host cells, as determined by TUNEL (TdT-mediated dUTP nick end labeling) assay, lactate dehydrogenase release, Giemsa staining, and reduction in activation of caspase 3, compared to toxin-treated macrophages that were transfected with a random sequence control siRNA. We also performed these assays using a human intestinal epithelial cell line (HT-29) and observed a similar trend of galectin-3 and SNAP23 association with Act-induced apoptosis. This is the first report of putative protein binding partners for this toxin and potential mediators/regulators of Act-induced apoptosis.
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Affiliation(s)
- C L Galindo
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Medical Research Building, 301 University Boulevard, Galveston, Texas 77555-1070, USA
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Galindo CL, Fadl AA, Sha J, Pillai L, Gutierrez C, Chopra AK. Microarray and proteomics analyses of human intestinal epithelial cells treated with the Aeromonas hydrophila cytotoxic enterotoxin. Infect Immun 2005; 73:2628-43. [PMID: 15845465 PMCID: PMC1087361 DOI: 10.1128/iai.73.5.2628-2643.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We performed microarray analyses on RNA from human intestinal epithelial (HT-29) cells treated with the cytotoxic enterotoxin (Act) of Aeromonas hydrophila to examine global cellular transcriptional responses. Based on three independent experiments, Act upregulated the expression of 34 genes involved in cell growth, adhesion, signaling, immune responses (including interleukin-8 [IL-8] production), and apoptosis. We verified the upregulation of 14 genes by real-time reverse transcriptase-PCR and confirmed Act-induced production of IL-8 by enzyme-linked immunosorbent assay on supernatants from nonpolarized and polarized HT-29 cells. Maximal production of IL-8 in response to Act required the presence of intracellular calcium, since chelation of calcium with BAPTA-AM significantly reduced Act-induced IL-8 production in HT-29 cells. We also examined activation of mitogen-activated protein kinases and, as demonstrated by Western blot analysis of apical side-treated polarized HT-29 cells, Act induced phosphorylation of p38, c-Jun NH(2)-terminal kinase, and extracellular signal-regulated kinase 1/2. In addition, KinetWorks proteomics screening of whole-cell lysates revealed Act-induced phosphorylation of cyclic AMP-response element binding protein (CREB), c-Jun, adducin, protein kinase C, and signal transducer and activator of transcription 3 (STAT3) and decreased phosphorylation of protein kinase Balpha, v-raf-1 murine leukemia viral oncogene homolog 1 (i.e., Raf1), and STAT1. We verified activation of CREB and activator protein 1 in polarized cells by gel shift assay. This is the first description of human intestinal epithelial cell transcriptional alterations, phosphorylation or activation of signaling molecules, cytokine production, and calcium mobilization in response to this toxin.
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Affiliation(s)
- C L Galindo
- Department of Microbiology and Immunology, Medical Research Building, 301 University Blvd., University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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Comer JE, Galindo CL, Chopra AK, Peterson JW. GeneChip analyses of global transcriptional responses of murine macrophages to the lethal toxin of Bacillus anthracis. Infect Immun 2005; 73:1879-85. [PMID: 15731093 PMCID: PMC1064962 DOI: 10.1128/iai.73.3.1879-1885.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We performed GeneChip analyses on RNA from Bacillus anthracis lethal toxin (LeTx)-treated RAW 264.7 murine macrophages to investigate global effects of anthrax toxin on host cell gene expression. Stringent analysis of data revealed that the expression of several mitogen-activated protein kinase kinase-regulatory genes was affected within 1.5 h post-exposure to LeTx. By 3.0 h, the expression of 103 genes was altered, including those involved in intracellular signaling, energy production, and protein metabolism.
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Affiliation(s)
- Jason E Comer
- Department of Microbiology and Immunology, Medical Research Building, 301 University Blvd., Galveston, TX 77555-1070, USA
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Jeyaseelan S, Chu HW, Young SK, Worthen GS. Transcriptional profiling of lipopolysaccharide-induced acute lung injury. Infect Immun 2004; 72:7247-56. [PMID: 15557650 PMCID: PMC529166 DOI: 10.1128/iai.72.12.7247-7256.2004] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mortality associated with acute lung injury (ALI) induced by lipopolysaccharide (LPS) remains high in humans, warranting improved treatment and prevention strategies. ALI is characterized by the expression of proinflammatory mediators and extensive neutrophil influx into the lung, followed by severe lung damage. Understanding the pathogenesis of LPS-induced ALI is a prerequisite for designing better therapeutic strategies. In the present study, we used microarrays to gain a global view of the transcriptional responses of the lung to LPS in a mouse model of ALI that mimics ALI in humans. A total of 71 inflammation-associated genes were up-regulated in LPS-treated lungs, including a chemokine, LPS-induced CXC chemokine (LIX), whose role in the induction of ALI is unknown. Most of the inflammatory genes peaked at 2 h post-LPS treatment. Real-time reverse transcription-PCR confirmed the LPS-induced up-regulation of selected genes identified by microarray analysis, including LIX. The up-regulation of LIX, tumor necrosis factor alpha, and macrophage inflammatory protein 2 was confirmed at the protein level by enzyme-linked immunosorbent assays. To determine the role of LIX in the induction of ALI, we used both exogenous LIX and a LIX blocking antibody. Exogenous LIX alone elicited a neutrophil influx in the lungs, and the anti-LIX antibody attenuated the LPS-induced neutrophil accumulation in the lungs. Taken together, the results of our study demonstrate for the first time the temporal expression of inflammatory genes during LPS-induced ALI and suggest that early therapeutic intervention is crucial to attenuate lung damage. Moreover, we identified a role for LIX in the induction of ALI, and therefore LIX may serve as a novel therapeutic target for the minimization of ALI.
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Affiliation(s)
- Samithamby Jeyaseelan
- Department of Medicine, National Jewish Medical and Research Center, 1400 Jackson St., Neustadt D-403, Denver, CO 80206, USA.
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Galindo CL, Fadl AA, Sha J, Chopra AK. Microarray analysis of Aeromonas hydrophila cytotoxic enterotoxin-treated murine primary macrophages. Infect Immun 2004; 72:5439-45. [PMID: 15322042 PMCID: PMC517445 DOI: 10.1128/iai.72.9.5439-5445.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We performed microarray analyses of murine peritoneal macrophages to examine cellular transcriptional responses to a cytotoxic enterotoxin of Aeromonas hydrophila. While 66% of altered genes were common to both primary macrophages and the murine macrophage cell line RAW 264.7, Act caused expression changes of 28 genes specifically in murine peritoneal macrophages.
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Affiliation(s)
- C L Galindo
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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Galindo CL, Fadl AA, Sha J, Gutierrez C, Popov VL, Boldogh I, Aggarwal BB, Chopra AK. Aeromonas hydrophila Cytotoxic Enterotoxin Activates Mitogen-activated Protein Kinases and Induces Apoptosis in Murine Macrophages and Human Intestinal Epithelial Cells. J Biol Chem 2004; 279:37597-612. [PMID: 15215244 DOI: 10.1074/jbc.m404641200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A cytotoxic enterotoxin (Act) of Aeromonas hydrophila possesses several biological activities, induces an inflammatory response in the host, and causes apoptosis of murine macrophages. In this study, we utilized five target cell types (a murine macrophage cell line (RAW 264.7), bone marrow-derived transformed macrophages, murine peritoneal macrophages, and two human intestinal epithelial cell lines (T84 and HT-29)) to investigate the effect of Act on mitogen-activated protein kinase (MAPK) pathways and mechanisms leading to apoptosis. As demonstrated by immunoprecipitation/kinase assays or Western blot analysis, Act activated stress-associated p38, c-Jun NH(2)-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2) in these cells. Act also induced phosphorylation of upstream MAPK factors (MAPK kinase 3/6 (MKK3/6), MKK4, and MAP/ERK kinase 1 (MEK1)) and downstream effectors (MAPK-activated protein kinase-2, activating transcription factor-2, and c-Jun). Act evoked cell membrane blebbing, caspase 3-cleavage, and activation of caspases 8 and 9 in these cells. In macrophages that do not express functional tumor necrosis factor receptors, apoptosis and caspase activities were significantly decreased. Immunoblotting of host whole cell lysates revealed Act-induced up-regulation of apoptosis-related proteins, including the mitochondrial proteins cytochrome c and apoptosis-inducing factor. However, mitochondrial membrane depolarization was not detected in response to Act. Taken together, the data demonstrated for the first time Act-induced activation of MAPK signaling and classical caspase-associated apoptosis in macrophages and intestinal epithelial cells. Given the importance of MAPK pathways and apoptosis in inflammation-associated diseases, this study provided new insights into the mechanism of action of Act on host cells.
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Affiliation(s)
- Cristi L Galindo
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1070, USA
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Sha J, Kozlova EV, Fadl AA, Olano JP, Houston CW, Peterson JW, Chopra AK. Molecular characterization of a glucose-inhibited division gene, gidA, that regulates cytotoxic enterotoxin of Aeromonas hydrophila. Infect Immun 2004; 72:1084-95. [PMID: 14742556 PMCID: PMC321642 DOI: 10.1128/iai.72.2.1084-1095.2004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 10/23/2003] [Accepted: 11/03/2003] [Indexed: 11/20/2022] Open
Abstract
By using a mini-transposon, we obtained two mutated strains of a diarrheal isolate, SSU, of Aeromonas hydrophila that exhibited a 50 to 53% reduction in the hemolytic activity and 83 to 87% less cytotoxic activity associated with the cytotoxic enterotoxin (Act). Act is a potent virulence factor of A. hydrophila and has been shown to contribute significantly to the development of both diarrhea and septicemia in animal models. Subsequent cloning and DNA sequence analysis revealed that transposon insertion occurred at different locations in these two mutants within the same 1,890-bp open reading frame for the glucose-inhibited division gene (gidA). A similar reduction in hemolytic (46%) and cytotoxic (81%) activity of Act was noted in the gidA isogenic mutant of A. hydrophila that was generated by marker exchange mutagenesis. Northern blot analysis revealed that the transcription of the cytotoxic enterotoxin gene (act) was not altered in the gidA transposon and isogenic mutants. However, by generating a chromosomal act::alkaline phosphatase gene (phoA) reporter construct, we demonstrated significantly reduced phosphatase activity in these mutants, indicating the effect of glucose-inhibited division (GidA) protein in modulating act gene expression at the translational level. The biological effects of Act in the gidA mutants were restored by complementation. The virulence of the gidA mutants in mice was dramatically reduced compared to the those of the wild-type (WT) and complemented strains of A. hydrophila. The histopathological examination of lungs, in particular, indicated severe congestion, alveolar hemorrhage, and acute inflammatory infiltrate in the interstitial compartment and the alveolar spaces when mice were infected with the WT and complemented strains. Minimal-to-mild changes were noted in the lungs with the gidA mutants. Taken together, our data indicate for the first time that GidA regulates the most-potent virulence factor of A. hydrophila, Act.
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Affiliation(s)
- Jian Sha
- Departments of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas 77555-1070, USA
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