351
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Bi N, Xiong C, Jin G, Guo Z, Gu G. Synthesis of a trisaccharide repeating unit of the O-antigen from Burkholderia cenocepacia and its dimer. Carbohydr Res 2017; 451:1-11. [DOI: 10.1016/j.carres.2017.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/05/2017] [Accepted: 09/05/2017] [Indexed: 12/13/2022]
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352
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Knockdown of microRNA-203 alleviates LPS-induced injury by targeting MCL-1 in C28/I2 chondrocytes. Exp Cell Res 2017; 359:171-178. [DOI: 10.1016/j.yexcr.2017.07.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/29/2017] [Accepted: 07/29/2017] [Indexed: 01/22/2023]
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353
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Zhang J, Yang X, Wang H, Zhao B, Wu X, Su L, Xie S, Wang Y, Li J, Liu J, Liu M, Han F, He T, Zhang W, Tao K, Hu D. PKCζ as a promising therapeutic target for TNFα-induced inflammatory disorders in chronic cutaneous wounds. Int J Mol Med 2017; 40:1335-1346. [PMID: 28949382 PMCID: PMC5627866 DOI: 10.3892/ijmm.2017.3144] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 08/21/2017] [Indexed: 02/06/2023] Open
Abstract
Protein kinase Cζ (PKCζ) is a member of the atypical protein kinase C family. Its roles in macrophages or skin-resident keratinocytes have not been fully evaluated. In this study, we provide evidence that PKCζ mediates lipopolysaccharide (LPS)-induced tumor necrosis factor α (TNFα) gene expression in the mouse macrophage cell line, RAW264.7. TNFα has been proven to be one of the main culprits of chronic wounds and impaired acute wounds, which are characterized by excessive inflammation, enhanced proteolysis and reduced matrix deposition. Among the multiple effects of TNFα on keratinocytes, the induction of chemokines which are indispensable factors involved in the massive infiltration of various inflammatory cells into skin lesions serves as a crucial mechanism. In the present study, we found that PKCζ inhibitor or its specific siRNA inhibited the TNFα-induced upregulation in the levels of the chemokines, interleukin (IL)-8, monocyte chemotactic protein-1 (MCP-1) and intercellular cell adhesion molecule-1 (ICAM-1) in HaCaT keratinocytes. Moreover, under a disrupted inflammatory environment, activated keratinocytes can synthesize large amounts of matrix metalloproteinases (MMP), which has a negative effect on tissue remodeling. We discovered that TNFα promoted the expression of MMP9 in a PKCζ-dependent manner. Further experiments revealed that nuclear factor-κB (NF-κB) was a key downstream molecule of PKCζ. In addition, as shown in vitro, PKCζ was not involved in the TNFα-induced decrease in HaCaT cell migration and proliferation. In vivo experiments demonstrated that TNFα-induced wound closure impairment and inflammatory disorders were significantly attenuated in the PKCζ inhibitor group. On the whole, our findings suggest that PKCζ is a crucial regulator in LPS- or TNFα-induced inflammatory responses in RAW264.7 cells and HaCaT keratinocytes, and that PKCζ/NF-κB signaling may be a potential target for interventional therapy for TNFα-induced skin inflammatory injury.
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Affiliation(s)
- Jian Zhang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Xuekang Yang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Hongtao Wang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Bin Zhao
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Xue Wu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Linlin Su
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Songtao Xie
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Yunchuan Wang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Jun Li
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Jiaqi Liu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Mengdong Liu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Fu Han
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Ting He
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Wei Zhang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Ke Tao
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Dahai Hu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
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354
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Keck J, Gupta R, Christenson LK, Arulanandam BP. MicroRNA mediated regulation of immunity against gram-negative bacteria. Int Rev Immunol 2017; 36:287-299. [PMID: 28800263 PMCID: PMC6904929 DOI: 10.1080/08830185.2017.1347649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Evidence over the last couple decades has comprehensively established that short, highly conserved, non-coding RNA species called microRNA (miRNA) exhibit the ability to regulate expression and function of host genes at the messenger RNA (mRNA) level. MicroRNAs play key regulatory roles in immune cell development, differentiation, and protective function. Intrinsic host immune response to invading pathogens rely on intricate orchestrated events in the development of innate and adaptive arms of immunity. We discuss the involvement of miRNAs in regulating these processes against gram negative pathogens in this review.
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Affiliation(s)
- Jonathon Keck
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
| | - Lane K. Christenson
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Bernard P. Arulanandam
- South Texas Center for Emerging Infectious Diseases and Center of Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249
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355
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Evaluation of changes to the Rickettsia rickettsii transcriptome during mammalian infection. PLoS One 2017; 12:e0182290. [PMID: 28832688 PMCID: PMC5568294 DOI: 10.1371/journal.pone.0182290] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/14/2017] [Indexed: 12/12/2022] Open
Abstract
The lifecycle of Rickettsia rickettsii includes infection of both mammalian and arthropod hosts, with each environment presenting distinct challenges to survival. As such, these pathogens likely have distinctive transcriptional strategies for infection of each host. Herein, we report the utilization of next generation sequencing (RNAseq) and bioinformatic analysis techniques to examine the global transcriptional profile of R. rickettsii within an infected animal, and to compare that data to transcription in tissue culture. The results demonstrate substantial R. rickettsii transcriptional alteration in vivo, such that the bacteria are considerably altered from cell culture. Identification of significant transcriptional changes and validation of RNAseq by quantitative PCR are described with particular emphasis on known antigens and suspected virulence factors. Together, these results suggest that transcriptional regulation of a distinct cohort of genes may contribute to successful mammalian infection.
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356
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Moreira LM, Soares MR, Facincani AP, Ferreira CB, Ferreira RM, Ferro MIT, Gozzo FC, Felestrino ÉB, Assis RAB, Garcia CCM, Setubal JC, Ferro JA, de Oliveira JCF. Proteomics-based identification of differentially abundant proteins reveals adaptation mechanisms of Xanthomonas citri subsp. citri during Citrus sinensis infection. BMC Microbiol 2017; 17:155. [PMID: 28693412 PMCID: PMC5504864 DOI: 10.1186/s12866-017-1063-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 07/01/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Xanthomonas citri subsp. citri (Xac) is the causal agent of citrus canker. A proteomic analysis under in planta infectious and non-infectious conditions was conducted in order to increase our knowledge about the adaptive process of Xac during infection. RESULTS For that, a 2D-based proteomic analysis of Xac at 1, 3 and 5 days after inoculation, in comparison to Xac growth in NB media was carried out and followed by MALDI-TOF-TOF identification of 124 unique differentially abundant proteins. Among them, 79 correspond to up-regulated proteins in at least one of the three stages of infection. Our results indicate an important role of proteins related to biofilm synthesis, lipopolysaccharides biosynthesis, and iron uptake and metabolism as possible modulators of plant innate immunity, and revealed an intricate network of proteins involved in reactive oxygen species adaptation during Plants` Oxidative Burst response. We also identified proteins previously unknown to be involved in Xac-Citrus interaction, including the hypothetical protein XAC3981. A mutant strain for this gene has proved to be non-pathogenic in respect to classical symptoms of citrus canker induced in compatible plants. CONCLUSIONS This is the first time that a protein repertoire is shown to be active and working in an integrated manner during the infection process in a compatible host, pointing to an elaborate mechanism for adaptation of Xac once inside the plant.
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Affiliation(s)
- Leandro M Moreira
- Departamento de Ciências Biológicas (DECBI), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil. .,Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil.
| | - Márcia R Soares
- Departamento de Bioquímica (DBq), Instituto de Química (IQ), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Agda P Facincani
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, Jaboticabal, SP, Brazil.
| | - Cristiano B Ferreira
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, Jaboticabal, SP, Brazil
| | - Rafael M Ferreira
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, Jaboticabal, SP, Brazil
| | - Maria I T Ferro
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, Jaboticabal, SP, Brazil
| | - Fábio C Gozzo
- Instituto de Química, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Érica B Felestrino
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - Renata A B Assis
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - Camila Carrião M Garcia
- Departamento de Ciências Biológicas (DECBI), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil.,Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - João C Setubal
- Departamento de Bioquímica (DB), Instituto de Química (IQ), Universidade de São Paulo (USP), São Paulo, SP, Brazil.,Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Jesus A Ferro
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, Jaboticabal, SP, Brazil
| | - Julio C F de Oliveira
- Departamento de Ciências Biológicas (DCB), Universidade Federal de São Paulo (UNIFESP), Diadema, SP, Brazil
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357
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Zhao Y, Jaber V, Lukiw WJ. Secretory Products of the Human GI Tract Microbiome and Their Potential Impact on Alzheimer's Disease (AD): Detection of Lipopolysaccharide (LPS) in AD Hippocampus. Front Cell Infect Microbiol 2017; 7:318. [PMID: 28744452 PMCID: PMC5504724 DOI: 10.3389/fcimb.2017.00318] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
Although the potential contribution of the human gastrointestinal (GI) tract microbiome to human health, aging, and disease is becoming increasingly acknowledged, the molecular mechanics and signaling pathways of just how this is accomplished is not well-understood. Major bacterial species of the GI tract, such as the abundant Gram-negative bacilli Bacteroides fragilis (B. fragilis) and Escherichia coli (E. coli), secrete a remarkably complex array of pro-inflammatory neurotoxins which, when released from the confines of the healthy GI tract, are pathogenic and highly detrimental to the homeostatic function of neurons in the central nervous system (CNS). For the first time here we report the presence of bacterial lipopolysaccharide (LPS) in brain lysates from the hippocampus and superior temporal lobe neocortex of Alzheimer's disease (AD) brains. Mean LPS levels varied from two-fold increases in the neocortex to three-fold increases in the hippocampus, AD over age-matched controls, however some samples from advanced AD hippocampal cases exhibited up to a 26-fold increase in LPS over age-matched controls. This “Perspectives” paper will further highlight some very recent research on GI tract microbiome signaling to the human CNS, and will update current findings that implicate GI tract microbiome-derived LPS as an important internal contributor to inflammatory degeneration in the CNS.
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Affiliation(s)
- Yuhai Zhao
- LSU Neuroscience Center, Louisiana State University Health Science CenterNew Orleans, LA, United States.,Department of Anatomy and Cell Biology, Louisiana State University Health Science CenterNew Orleans, LA, United States
| | - Vivian Jaber
- LSU Neuroscience Center, Louisiana State University Health Science CenterNew Orleans, LA, United States
| | - Walter J Lukiw
- LSU Neuroscience Center, Louisiana State University Health Science CenterNew Orleans, LA, United States.,Department of Ophthalmology, Louisiana State University Health Science CenterNew Orleans, LA, United States.,Department of Neurology, Louisiana State University Health Science CenterNew Orleans, LA, United States
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358
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Lee J, Patel DS, Kucharska I, Tamm LK, Im W. Refinement of OprH-LPS Interactions by Molecular Simulations. Biophys J 2017; 112:346-355. [PMID: 28122220 DOI: 10.1016/j.bpj.2016.12.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/27/2016] [Accepted: 12/05/2016] [Indexed: 12/16/2022] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria is composed of lipopolysaccharide (LPS) in the outer leaflet and phospholipids in the inner leaflet. The outer membrane protein H (OprH) of Pseudomonas aeruginosa provides an increased stability to the OMs by directly interacting with LPS. Here we report the influence of various P. aeruginosa and, for comparison, Escherichia coli LPS environments on the physical properties of the OMs and OprH using all-atom molecular dynamics simulations. The simulations reveal that although the P. aeruginosa OMs are thinner hydrophobic bilayers than the E. coli OMs, which is expected from the difference in the acyl chain length of their lipid A, this effect is almost imperceptible around OprH due to a dynamically adjusted hydrophobic match between OprH and the OM. The structure and dynamics of the extracellular loops of OprH show distinct behaviors in different LPS environments. Including the O-antigen greatly reduces the flexibility of the OprH loops and increases the interactions between these loops and LPS. Furthermore, our study shows that the interactions between OprH and LPS mainly depend on the secondary structure of OprH and the chemical structure of LPS, resulting in distinctive patterns in different LPS environments.
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Affiliation(s)
- Joonseong Lee
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania; Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania
| | - Dhilon S Patel
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania; Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania
| | - Iga Kucharska
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Lukas K Tamm
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania; Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania.
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359
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Hassan AA, Maldonado RF, Dos Santos SC, Di Lorenzo F, Silipo A, Coutinho CP, Cooper VS, Molinaro A, Valvano MA, Sá-Correia I. Structure of O-Antigen and Hybrid Biosynthetic Locus in Burkholderia cenocepacia Clonal Variants Recovered from a Cystic Fibrosis Patient. Front Microbiol 2017. [PMID: 28642745 PMCID: PMC5462993 DOI: 10.3389/fmicb.2017.01027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen associated with chronic lung infections and increased risk of death in patients with cystic fibrosis (CF). In this work, we investigated the lipopolysaccharide (LPS) of clinical variants of B. cenocepacia that were collected from a CF patient over a period of 3.5 years, from the onset of infection until death by necrotizing pneumonia (cepacia syndrome). We report the chemical structure of the LPS molecule of various sequential isolates and the identification of a novel hybrid O-antigen (OAg) biosynthetic cluster. The OAg repeating unit of the LPS from IST439, the initial isolate, is a [→2)-β-D-Ribf-(1→4)-α-D-GalpNAc-(1→] disaccharide, which was not previously described in B. cenocepacia. The IST439 OAg biosynthetic gene cluster contains 7 of 23 genes that are closely homologous to genes found in B. multivorans, another member of the Burkholderia cepacia complex. None of the subsequent isolates expressed OAg. Genomic sequencing of these isolates enabled the identification of mutations within the OAg cluster, but none of these mutations could be associated with the loss of OAg. This study provides support to the notion that OAg LPS modifications are an important factor in the adaptation of B. cenocepacia to chronic infection and that the heterogeneity of OAgs relates to variation within the OAg gene cluster, indicating that the gene cluster might have been assembled through multiple horizontal transmission events.
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Affiliation(s)
- A A Hassan
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Rita F Maldonado
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Sandra C Dos Santos
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Carla P Coutinho
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, PittsburghPA, United States
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli Federico II Complesso Universitário Monte SantangeloNapoli, Italy
| | - Miguel A Valvano
- The Wellcome-Wolfson Institute for Experimental Medicine, Queen's University BelfastBelfast, United Kingdom
| | - Isabel Sá-Correia
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de LisboaLisboa, Portugal
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360
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Effect of luteolin on inflammatory responses in RAW264.7 macrophages activated with LPS and IFN-γ. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.02.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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361
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Salmonella enterica Serovar Typhi Lipopolysaccharide O-Antigen Modification Impact on Serum Resistance and Antibody Recognition. Infect Immun 2017; 85:IAI.01021-16. [PMID: 28167670 PMCID: PMC5364305 DOI: 10.1128/iai.01021-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/30/2017] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhi is a human-restricted Gram-negative bacterial pathogen responsible for causing an estimated 27 million cases of typhoid fever annually, leading to 217,000 deaths, and current vaccines do not offer full protection. The O-antigen side chain of the lipopolysaccharide is an immunodominant antigen, can define host-pathogen interactions, and is under consideration as a vaccine target for some Gram-negative species. The composition of the O-antigen can be modified by the activity of glycosyltransferase (gtr) operons acquired by horizontal gene transfer. Here we investigate the role of two gtr operons that we identified in the S. Typhi genome. Strains were engineered to express specific gtr operons. Full chemical analysis of the O-antigens of these strains identified gtr-dependent glucosylation and acetylation. The glucosylated form of the O-antigen mediated enhanced survival in human serum and decreased complement binding. A single nucleotide deviation from an epigenetic phase variation signature sequence rendered the expression of this glucosylating gtr operon uniform in the population. In contrast, the expression of the acetylating gtrC gene is controlled by epigenetic phase variation. Acetylation did not affect serum survival, but phase variation can be an immune evasion mechanism, and thus, this modification may contribute to persistence in a host. In murine immunization studies, both O-antigen modifications were generally immunodominant. Our results emphasize that natural O-antigen modifications should be taken into consideration when assessing responses to vaccines, especially O-antigen-based vaccines, and that the Salmonellagtr repertoire may confound the protective efficacy of broad-ranging Salmonella lipopolysaccharide conjugate vaccines.
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362
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Zaric SS, Lappin MJ, Fulton CR, Lundy FT, Coulter WA, Irwin CR. Sialylation of Porphyromonas gingivalis LPS and its effect on bacterial-host interactions. Innate Immun 2017; 23:319-326. [PMID: 28205451 DOI: 10.1177/1753425917694245] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Porphyromonas gingivalis produces different LPS isoforms with significant structural variations of their lipid A and O-antigen moieties that can affect its pro-inflammatory and bone-resorbing potential. We show here, for the first time, that P. gingivalis LPS isolated from W83 strain is highly sialylated and possesses significantly reduced inflammatory potential compared with less sialylated ATCC 33277 strain LPS. Nevertheless, the reduction in the endotoxin activity is not mediated by the presence of sialic acid LPS moieties as the sialic acid-free LPS produced by the mutant W83 strain exhibits a similar inflammatory potential to the wild type strain. Furthermore, our findings suggest that the interaction between the sialic acid LPS moieties and the inhibitory CD33 receptor is prevented by endogenously expressed sialic acid on the surface of THP-1 cells that cannot be out-competed by sialic acid containing P. gingivalis LPS. The present study also highlights the importance of endogenous sialic acid as a 'self-associated molecular pattern' and CD33 receptors in modulation of innate immune response as human gingival fibroblasts, which do not express CD33 receptors, and desialylated THP-1 cells have both been found to have much higher spontaneous IL-8 production than naïve THP-1 cells.
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Affiliation(s)
- Svetislav S Zaric
- 1 Plymouth University, Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - Mark J Lappin
- 2 Queen's University Belfast, Centre for Dentistry, Belfast, UK
| | - Catherine R Fulton
- 3 Queen's University Belfast, Centre for Experimental Medicine, Belfast, UK
| | - Fionnuala T Lundy
- 3 Queen's University Belfast, Centre for Experimental Medicine, Belfast, UK
| | - Wilson A Coulter
- 4 University of Ulster, School of Biomedical Science, Coleraine, UK
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363
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Ma H, Cummins DD, Edelstein NB, Gomez J, Khan A, Llewellyn MD, Picudella T, Willsey SR, Nangia S. Modeling Diversity in Structures of Bacterial Outer Membrane Lipids. J Chem Theory Comput 2017; 13:811-824. [DOI: 10.1021/acs.jctc.6b00856] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Huilin Ma
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Daniel D. Cummins
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Natalie Brooke Edelstein
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Jerry Gomez
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Aliza Khan
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Masud Dikita Llewellyn
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Tara Picudella
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Sarah Rose Willsey
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Shikha Nangia
- Department of Biomedical
and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
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364
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Fathy Mohamed Y, Hamad M, Ortega XP, Valvano MA. The LpxL acyltransferase is required for normal growth and penta-acylation of lipid A in Burkholderia cenocepacia. Mol Microbiol 2017; 104:144-162. [PMID: 28085228 DOI: 10.1111/mmi.13618] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2017] [Indexed: 12/27/2022]
Abstract
Lipid A anchors the lipopolysaccharide (LPS) to the outer membrane and is usually composed of a hexa-acylated diglucosamine backbone. Burkholderia cenocepacia, an opportunistic pathogen, produces a mixture of tetra- and penta-acylated lipid A. "Late" acyltransferases add secondary acyl chains to lipid A after the incorporation of four primary acyl chains to the diglucosamine backbone. Here, we report that B. cenocepacia has only one late acyltransferase, LpxL (BCAL0508), which adds a myristoyl chain to the 2' position of lipid A resulting in penta-acylated lipid A. We also identified PagL (BCAL0788), which acts as an outer membrane lipase by removing the primary β-hydroxymyristate (3-OH-C14:0) chain at the 3 position, leading to tetra-acylated lipid A. Unlike PagL, LpxL depletion caused reduced cell growth and defects in cell morphology, both of which were suppressed by overexpressing the LPS flippase MsbA (BCAL2408), suggesting that lipid A molecules lacking the fifth acyl chain contributed by LpxL are not good substrates for the flippase. We also show that intracellular B. cenocepacia within macrophages produced more penta-acylated lipid A, suggesting lipid A penta-acylation in B. cenocepacia is required not only for bacterial growth and morphology but also for adaptation to intracellular lifestyle.
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Affiliation(s)
- Yasmine Fathy Mohamed
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT9 7BL, UK.,Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Mohamad Hamad
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada, N6A 5C1
| | - Ximena P Ortega
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada, N6A 5C1
| | - Miguel A Valvano
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT9 7BL, UK.,Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada, N6A 5C1
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365
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Moreira AS, Lourenço AB, Sá-Correia I. 1H-NMR-Based Endometabolome Profiles of Burkholderia cenocepacia Clonal Variants Retrieved from a Cystic Fibrosis Patient during Chronic Infection. Front Microbiol 2016; 7:2024. [PMID: 28066350 PMCID: PMC5167703 DOI: 10.3389/fmicb.2016.02024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/02/2016] [Indexed: 12/21/2022] Open
Abstract
During cystic fibrosis (CF) chronic lung infections, bacteria of the Burkholderia cepacia complex (Bcc) are exposed for several years to a stressful and changing environment. These environmental challenges results in genetic changes of the initial infecting strain with the consequent diversification of genotypes and phenotypes. The exploitation of functional and comparative genomic approaches has suggested that such diversification is associated with massive metabolic remodeling but these alterations are poorly understood. In the present work, we have explored a high resolution 1H-NMR-based metabolomic approach coupled to multivariate analysis to compare the endometabolome of three B. cenocepacia clonal variants retrieved from a CF patient from the onset of infection (IST439) until death with cepacia syndrome after 3.5 years (IST4113 and IST4134), to complement former proteomic and transcriptomic analyses. A fourth clonal variant (IST4129) retrieved from the same CF patient when the clinical condition worsened during the last months of life, was also examined since it was found to lack the third replicon. The metabolomic profiles obtained, based on the complete 1H-NMR spectra, highlight the separation of the four clonal variants examined, the most distinct profile corresponding to IST4129. Results indicate a variable content of several amino acids in the different isolates examined and suggest that glycolysis and the glyoxylate shunt are favored in late variants. Moreover, the concentration of two metabolites with demonstrated cellular protective functions against stress, glycine-betaine and trehalose, is different in the different isolates examined. However, no clear correlation could be established between their content and stress tolerance. For example, IST4113, previously found to be the most resistant variant to antimicrobials of different classes, exhibits low levels of trehalose and glycine-betaine but the highest resistance to heat and oxidative stress. Also, IST4129, with a high level of glycine-betaine but lacking the third replicon, previously associated with stress resistance and virulence, exhibits the highest susceptibility to all the stresses tested. Taken together, results from this study provide insights into the metabolic diversification of B. cenocepacia clonal variants during long-term infection of the CF airways.
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Affiliation(s)
- Ana S Moreira
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
| | - Artur B Lourenço
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
| | - Isabel Sá-Correia
- Department of Bioengineering, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa (ULISBOA) Lisbon, Portugal
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366
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pqiABC and yebST, Putative mce Operons of Escherichia coli, Encode Transport Pathways and Contribute to Membrane Integrity. J Bacteriol 2016; 199:JB.00606-16. [PMID: 27795327 DOI: 10.1128/jb.00606-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/04/2016] [Indexed: 01/01/2023] Open
Abstract
The membranes of single-cell organisms are crucial as the first line of defense. The outer membrane of Gram-negative bacteria is an asymmetric bilayer in which lipopolysaccharides (LPSs) and phospholipids are localized in the outer and inner leaflet, respectively. This asymmetry is important for membrane integrity. In Escherichia coli, the Mla transport pathway maintains this asymmetry by removing phospholipids from the outer leaflet. The MlaD component of this system is a mammalian cell entry (MCE) domain protein, and E. coli has two other MCE domain proteins of unknown function (PqiB and YebT). Here, we show that these two proteins are components of novel transport pathways that contribute to membrane integrity. The pqiAB operon is regulated by SoxS and RpoS. The yebST operon contains pqiAB homologues. Here, we found a third member of the pqi operon, ymbA (pqiC). A PqiB-PqiC complex bridges the inner and the outer membrane, and in other bacteria, pqiBC genes are located in operons together with transporter proteins. We show here that simultaneous deletion of pqiABC and yebST operons in an Δmla background rendered cells more sensitive to SDS-EDTA, and the SDS-EDTA sensitivity of mla mutants was rescued by additional copies of pqiABC We also found that the yebST operon was induced by a defect in LPS molecules. In conclusion, PqiABC and YebST are novel transport pathways related to the Mla transport pathway and important for membrane integrity. IMPORTANCE Membranes of bacteria are crucial for stress resistance. The composition of the E. coli outer membrane is asymmetric, with asymmetry maintained by the Mla ABC transport pathway. We propose that the stress-inducible pqiABC operon and homologous yebST operon, both of previously unknown function, encode transport pathway proteins related to the Mla transport pathway. Deletion of these operons rendered cells more sensitive to membrane stress, and additional copies of pqiABC suppressed the SDS-EDTA sensitivity of mla mutant strains. We found that yebS'-'lacZ fusion was activated in mutant strains with defective LPS molecules.
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Lukiw WJ. The microbiome, microbial-generated proinflammatory neurotoxins, and Alzheimer's disease. JOURNAL OF SPORT AND HEALTH SCIENCE 2016; 5:393-396. [PMID: 28446989 PMCID: PMC5403149 DOI: 10.1016/j.jshs.2016.08.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 06/07/2023]
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368
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Lukiw WJ. Bacteroides fragilis Lipopolysaccharide and Inflammatory Signaling in Alzheimer's Disease. Front Microbiol 2016; 7:1544. [PMID: 27725817 PMCID: PMC5035737 DOI: 10.3389/fmicb.2016.01544] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/15/2016] [Indexed: 12/29/2022] Open
Abstract
The human microbiome consists of ~3.8 × 1013 symbiotic microorganisms that form a highly complex and dynamic ecosystem: the gastrointestinal (GI) tract constitutes the largest repository of the human microbiome by far, and its impact on human neurological health and disease is becoming increasingly appreciated. Bacteroidetes, the largest phylum of Gram-negative bacteria in the GI tract microbiome, while generally beneficial to the host when confined to the GI tract, have potential to secrete a remarkably complex array of pro-inflammatory neurotoxins that include surface lipopolysaccharides (LPSs) and toxic proteolytic peptides. The deleterious effects of these bacterial exudates appear to become more important as GI tract and blood-brain barriers alter or increase their permeability with aging and disease. For example, presence of the unique LPSs of the abundant Bacteroidetes species Bacteroides fragilis (BF-LPS) in the serum represents a major contributing factor to systemic inflammation. BF-LPS is further recognized by TLR2, TLR4, and/or CD14 microglial cell receptors as are the pro-inflammatory 42 amino acid amyloid-beta (Aβ42) peptides that characterize Alzheimer's disease (AD) brain. Here we provide the first evidence that BF-LPS exposure to human primary brain cells is an exceptionally potent inducer of the pro-inflammatory transcription factor NF-kB (p50/p65) complex, a known trigger in the expression of pathogenic pathways involved in inflammatory neurodegeneration. This 'Perspectives communication' will in addition highlight work from recent studies that advance novel and emerging concepts on the potential contribution of microbiome-generated factors, such as BF-LPS, in driving pro-inflammatory degenerative neuropathology in the AD brain.
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Affiliation(s)
- Walter J Lukiw
- Bollinger Professor of Alzheimer's disease (AD), Neuroscience Center and Departments of Neurology and Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA USA
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