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Sample records for bacterial lipopolysaccharide lps

  1. Lipopolysaccharide (LPS)-binding protein mediates LPS detoxification by chylomicrons

    NARCIS (Netherlands)

    Vreugdenhil, Anita C. E.; Rousseau, Corine H.; Hartung, Thomas; Greve, Jan Willem M.; van 't Veer, Cornelis; Buurman, Wim A.

    2003-01-01

    Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with

  2. Detection of an Actinobacillus pleuropneumoniae serotype 2 lipopolysaccharide (LPS) variant

    DEFF Research Database (Denmark)

    Stenbaek, E.I.; HovindHaugen, K.

    1996-01-01

    Until now 12 serotypes of Actinobacillus pleuropneumoniae have been recognized. The specificity of the serotypes reside in the carbohydrate composition of the capsular polysaccharides and lipopolysaccharides (LPS). The LPS of A. pleuropneumoniae serotype 2 is a smooth type LPS with O......-PAGE). The MAI, 102-G02 was directed against an epitope on the O-chain of the LPS and was used to define a new LPS variant of A. pleuropneumoniae serotype 2 (referred to as A. pleuropneumoniae serotype 2X). Investigation of the reactivity of the MAb 102-G02 against an A. pleuropneumoniae serotype 2X field...

  3. Lipopolysaccharide (LPS)-Induced Autophagy Is Responsible for Enhanced Osteoclastogenesis.

    Science.gov (United States)

    Sul, Ok-Joo; Park, Hyun-Jung; Son, Ho-Jung; Choi, Hye-Seon

    2017-11-30

    We hypothesized that inflammation affects number and activity of osteoclasts (OCs) via enhancing autophagy. Lipopolysaccharide (LPS) induced autophagy, osteoclastogenesis, and cytoplasmic reactive oxygen species (ROS) in bone marrow-derived macrophages that were pre-stimulated with receptor activator of nuclear factor-κB ligand. An autophagy inhibitor, 3-methyladenine (3-MA) decreased LPS-induced OC formation and bone resorption, indicating that autophagy is responsible for increasing number and activity of OCs upon LPS stimulus. Knockdown of autophagy-related protein 7 attenuated the effect of LPS on OC-specific genes, supporting a role of LPS as an autophagy inducer in OC. Removal of ROS decreased LPS-induced OC formation as well as autophagy. However, 3-MA did not affect LPS-induced ROS levels, suggesting that ROS act upstream of phosphatidylinositol-4,5-bisphosphate 3-kinase in LPS-induced autophagy. Our results suggest the possible use of autophagy inhibitors targeting OCs to reduce inflammatory bone loss.

  4. Modulation of immune response by bacterial lipopolysaccharide (LPS): cellular basis of stimulatory and inhibitory effects of LPS on the in vitro IGM antibody response to a T-dependent antigen

    International Nuclear Information System (INIS)

    Uchiyama, T.; Jacobs, D.M.

    1978-01-01

    The role of thymus-derived lymphocytes (T cells) in LPS modulation of T cell-development antibody responses has been investigated. We have assessed the effect of LPS on the primary anti-TNP response to TNP-SRBC of cultures of whole spleen cells or T cell-depleted spleen cells that were supplemented with various subpopulations of carrier-primed (SRBC) spleen cells. The TNP-PFC response was enhanced in the presence of irradiated SRBC-primed spleen cells by addition of 0.16 to 20 μg/ml LPS, but inhibition was observed when irradiation of primed cells was omitted. Enhancement but no inhibition occurred when added primed cells were first passed through a nylon wool column. LPS-mediated enhancement was dependent on a T cell in the primed population. These results suggest that LPS modulation of antibody synthesis is dependent on two populations of antigen-specific cells that have opposing effects on B cell responses to a T-dependent antigen: a helper cell that is irradiation resistant, nonadherent to nylon wool, and sensitive to anti-T cell serum, and a suppressor cell that is irradiation sensitive and adherent to nylon wool

  5. Transcriptional profiling of the effect of lipopolysaccharide (LPS) pretreatment in blood from probiotics-treated dairy cows.

    Science.gov (United States)

    Adjei-Fremah, Sarah; Ekwemalor, Kingsley; Asiamah, Emmanuel; Ismail, Hamid; Worku, Mulumebet

    2016-12-01

    Probiotic supplements are beneficial for animal health and rumen function; and lipopolysaccharides (LPS) from gram negative bacteria have been associated with inflammatory diseases. In this study the transcriptional profile in whole blood collected from probiotics-treated cows was investigated in response to stimulation with lipopolysaccharides (LPS) in vitro. Microarray experiment was performed between LPS-treated and control samples using the Agilent one-color bovine v2 bovine (v2) 4x44K array slides. Global gene expression analysis identified 13,658 differentially expressed genes (fold change cutoff ≥ 2, P probiotics may stimulate the innate immune response of animal against parasitic and bacterial infections. We have provided a detailed description of the experimental design, microarray experiment and normalization and analysis of data which have been deposited into NCBI Gene Expression Omnibus (GEO): GSE75240.

  6. DMPD: Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, thereceptor for LPS/LBP complexes: a short review. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1373512 Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, therec....html) (.csml) Show Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, thereceptor for LPS.../LBP complexes: a short review. PubmedID 1373512 Title Function of lipopolysaccha

  7. Cyclic Limulus anti-lipopolysaccharide (LPS) factor-derived peptide CLP-19 antagonizes LPS function by blocking binding to LPS binding protein.

    Science.gov (United States)

    Liu, Yao; Ni, Bing; Ren, Jian-dong; Chen, Jian-hong; Tian, Zhi-qiang; Tang, Min; Li, Di; Xia, Peiyuan

    2011-01-01

    Inflammation and septic shock due to endotoxins from Gram-negative bacteria infection continue to pose significant challenges to human healthcare. It is, therefore, necessary to develop therapeutic strategies targeting endotoxins, such as lipopolysaccharide (LPS), to prevent their potentially systemic effects. Pathogenesis due to Gram-negative bacteria involves LPS binding to the host LPS-binding protein (LBP), causing detrimental downstream signaling cascades. Our previous study showed that CLP-19, a synthetic peptide derived from the Limulus anti-LPS factor (LALF), could effectively neutralize LPS toxicity; however, the detailed mechanisms underlying this anti-LPS effect remained unexplained. Thus, we carried out investigations to determine how the CLP-19 neutralizes LPS toxicity. CLP-19 was found to block LPS binding to LBP in a dose-dependent manner, as evidenced by competitive enzyme-linked immunosorbent assay (ELISA). In peripheral blood mononuclear cells, CLP-19 blocked LPS-induced phosphorylation of mitogen activated protein kinase (MAPK) signaling proteins p38, extracellular signal-regulating kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK)1/2. Furthermore, CLP-19 potency in LPS antagonism in vitro and in vivo was directly associated with its ability to block the LPS-LBP interaction. Taken together, the results suggested that CLP-19's inhibitory effect on LPS-LBP binding and on the subsequent MAPK pathway signaling may be responsible for its anti-LPS mechanism. This peptide appears to represent a potential therapeutic agent for clinical treatment of sepsis.

  8. Optimized triton X-114 assisted lipopolysaccharide (LPS) removal method reveals the immunomodulatory effect of food proteins

    NARCIS (Netherlands)

    Teodorowicz, Malgorzata; Perdijk, Olaf; Verhoek, Iris; Govers, Coen; Savelkoul, Huub F.J.; Tang, Yongfu; Wichers, Harry; Broersen, Kerensa

    2017-01-01

    Scope Investigations into the immunological response of proteins is often masked by lipopolysaccharide (LPS) contamination. We report an optimized Triton X-114 (TX-114) based LPS extraction method for β-lactoglobulin (BLG) and soy protein extract suitable for cell-based immunological assays.

  9. Optimized triton X-114 assisted lipopolysaccharide (LPS) removal method reveals the immunomodulatory effect of food proteins

    NARCIS (Netherlands)

    Teodorowicz, Malgorzata; Perdijk, Olaf; Verhoek, Iris; Govers, Coen; Savelkoul, Huub F.J.; Tang, Yongfu; Wichers, Harry; Broersen, Kerensa

    2017-01-01

    Scope Investigations into the immunological response of proteins is often masked by lipopolysaccharide (LPS) contamination. We report an optimized Triton X-114 (TX-114) based LPS extraction method for β-lactoglobulin (BLG) and soy protein extract suitable for cell-based immunological assays. Methods

  10. [Analysis of lipopolysaccharide (LPS) from impermeability-type drug resistant Pseudomonas aeruginosa using new, highly-sensitive LPS staining method].

    Science.gov (United States)

    O'Hara, K; Fukuda, H; Nakahara, H; Bryan, L E

    1994-10-01

    The specific ladder pattern on polyacrylamide gel electropholesis of lipopolysaccharide (LPS) extracted from Pseudomonas aeruginosa was clearly shown by using the complex methods of the PAS staining, re-periodate oxidation and then Ag-staining method. Accordingly, it was concluded that the new method was greatly useful for a detail analysis of LPS changes in Gram-negative bacteria. And it was shown by this method that no changes in LPS occurred between the impermeability-type drug resistant P. aeruginosa mediated by R plasmid and a drug susceptible strain. The absence of changes indicated that the LPS of P. aeruginosa K-Ps102 had not role in the mechanism of the high drug resistance.

  11. On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death.

    Science.gov (United States)

    Kell, Douglas B; Pretorius, Etheresia

    2015-11-01

    We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.

  12. Priming, induction and modulation of plant defence responses by bacterial lipopolysaccharides

    DEFF Research Database (Denmark)

    Newman, Mari-Anne; Dow, J. Maxwell; Molinaro, Antonio

    2007-01-01

    to the triggering of defence responses or to the priming of the plant to respond more rapidly and/or to a greater degree to subsequent pathogen challenge. LPS from symbiotic bacteria can have quite different effects on plants to those of pathogens. Some details are emerging of the structures within LPS......Bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPS contributes to the low permeability of the outer membrane, which acts as a barrier to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPS by plant cells can lead...... that are responsible for induction of these different plant responses. The lipid A moiety is not solely responsible for all of the effects of LPS in plants; core oligosaccharide and O-antigen components can elicit specific responses. Here, we review the effects of LPS in induction of defence-related responses...

  13. Transcriptional profiling of the effect of lipopolysaccharide (LPS pretreatment in blood from probiotics-treated dairy cows

    Directory of Open Access Journals (Sweden)

    Sarah Adjei-Fremah

    2016-12-01

    Full Text Available Probiotic supplements are beneficial for animal health and rumen function; and lipopolysaccharides (LPS from gram negative bacteria have been associated with inflammatory diseases. In this study the transcriptional profile in whole blood collected from probiotics-treated cows was investigated in response to stimulation with lipopolysaccharides (LPS in vitro. Microarray experiment was performed between LPS-treated and control samples using the Agilent one-color bovine v2 bovine (v2 4x44K array slides. Global gene expression analysis identified 13,658 differentially expressed genes (fold change cutoff ≥ 2, P < 0.05, 3816 upregulated genes and 9842 downregulated genes in blood in response to LPS. Treatment with LPS resulted in increased expression of TLR4 (Fold change (FC = 3.16 and transcription factor NFkB (FC = 5.4 and decreased the expression of genes including TLR1 (FC = −2.54, TLR3 (FC = −2.43, TLR10 (FC = −3.88, NOD2 (FC = −2.4, NOD1 (FC = −2.45 and pro-inflammatory cytokine IL1B (−3.27. The regulation of the genes involved in inflammation signaling pathway suggests that probiotics may stimulate the innate immune response of animal against parasitic and bacterial infections. We have provided a detailed description of the experimental design, microarray experiment and normalization and analysis of data which have been deposited into NCBI Gene Expression Omnibus (GEO: GSE75240.

  14. Role for glutathione in the hyposensitivity of LPS-pretreated mice to LPS anorexia

    OpenAIRE

    Hernadfalvi, Noemi; Langhans, Wolfgang; Meyenburg, Claudia von; Onteniente, Brigitte; Richard, Denis; Arsenijevic, Denis

    2008-01-01

    To study the role of the redox state regulator glutathione (GSH) in bacterial lipopolysaccharide (LPS)-induced anorexia we measured GSH in liver, serum and brain in response to intraperitoneal (ip) lipopolysaccharide (LPS, 4μg/mouse) injection in LPS-naïve and LPS-pretreated (4 μg/mouse) mice. LPS reduced food intake in LPS-naïve mice and LPS pretreatment attenuated this effect. LPS reduced total reduced GSH at 24 hours after injection in LPS-naïve mice. On the other hand, LPS pretreatment ca...

  15. Retention of bacterial lipopolysaccharide at the site of subcutaneous injection.

    OpenAIRE

    Yokochi, T.; Inoue, Y.; Yokoo, J.; Kimura, Y.; Kato, N.

    1989-01-01

    The tissue distribution of Klebsiella pneumoniae O3 lipopolysaccharide (KO3 LPS) was studied in mice injected subcutaneously (s.c.) or intraperitoneally (i.p.) with 125I-labeled KO3 LPS. Marked retention of KO3 LPS radioactivity could be found at the site of s.c. injection for several weeks. On the other hand, about 85% of the radioactivity rapidly disappeared from the peritoneal cavity within 6 h after i.p. injection. The long-term presence of KO3 LPS at the injection site was also supported...

  16. DMPD: Structural and functional analyses of bacterial lipopolysaccharides. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12106784 Structural and functional analyses of bacterial lipopolysaccharides. Carof...html) (.csml) Show Structural and functional analyses of bacterial lipopolysaccharides. PubmedID 12106784 Ti...tle Structural and functional analyses of bacterial lipopolysaccharides. Authors

  17. Ingestion of bacterial lipopolysaccharide inhibits peripheral taste responses to sucrose in mice

    Science.gov (United States)

    Zhu, Xiaobin; He, Lianying; McCluskey, Lynnette Phillips

    2013-01-01

    A fundamental role of the taste system is to discriminate between nutritive and toxic foods. However, it is unknown whether bacterial pathogens that might contaminate food and water modulate the transmission of taste input to the brain. We hypothesized that exogenous, bacterially-derived lipopolysaccharide (LPS), modulates neural responses to taste stimuli. Neurophysiological responses from the chorda tympani nerve, which innervates taste cells on the anterior tongue, were unchanged by acute exposure to LPS. Instead, neural responses to sucrose were selectively inhibited in mice that drank LPS during a single overnight period. Decreased sucrose sensitivity appeared 7 days after LPS ingestion, in parallel with decreased lingual expression of Tas1r2 and Tas1r3 transcripts, which are translated to T1R2+T1R3 subunits forming the sweet taste receptor. Tas1r2 and Tas1r3 mRNA expression levels and neural responses to sucrose were restored by 14 days after LPS consumption. Ingestion of LPS, rather than contact with taste receptor cells, appears to be necessary to suppress sucrose responses. Furthermore, mice lacking the Toll-like receptor (TLR) 4 for LPS were resistant to neurophysiological changes following LPS consumption. These findings demonstrate that ingestion of LPS during a single period specifically and transiently inhibits neural responses to sucrose. We suggest that LPS drinking initiates TLR4-dependent hormonal signals that downregulate sweet taste receptor genes in taste buds. Delayed inhibition of sweet taste signaling may influence food selection and the complex interplay between gastrointestinal bacteria and obesity. PMID:24215981

  18. Attenuation of lipopolysaccharide (LPS-induced cytotoxicity by tocopherols and tocotrienols

    Directory of Open Access Journals (Sweden)

    Keiko Nishio

    2013-01-01

    Full Text Available Lipopolysaccharide (LPS induces host inflammatory responses and tissue injury and has been implicated in the pathogenesis of various age-related diseases such as acute respiratory distress syndrome, vascular diseases, and periodontal disease. Antioxidants, particularly vitamin E, have been shown to suppress oxidative stress induced by LPS, but the previous studies with different vitamin E isoforms gave inconsistent results. In the present study, the protective effects of α- and γ-tocopherols and α- and γ-tocotrienols on the oxidative stress induced by LPS against human lung carcinoma A549 cells were studied. They suppressed intracellular reactive oxygen formation, lipid peroxidation, induction of inflammatory mediator cytokines, and cell death. Tocopherols were incorporated into cultured cells much slower than tocotrienols but could suppress LPS-induced oxidative stress at much lower intracellular concentration than tocotrienols. Considering the bioavailability, it was concluded that α-tocopherol may exhibit the highest protective capacity among the vitamin E isoforms against LPS-induced oxidative stress.

  19. Effect of low-intensity electromagnetic radiation on structurization properties of bacterial lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Brill G.E.

    2013-12-01

    Full Text Available Purpose: to investigate the effects of low-intensity electromagnetic radiation on the process of dehydration self-organization of bacterial lipopolysaccharide. Materials and Methods. The method of wedge dehydration has been used to study the structure formation of bacterial lipopolysaccharide. Image-phases analysis included their qualitative characteristics, as well as the calculation of quantitative indicators, followed by statistical analysis. Results. UHF-Radiation (1GHz, 0,1 uW/cm2, 10 min has led to the changes in the suspension system of the LPS-saline reflected in the kinetics of structure formation. Conclusion. 1 GHz corresponds to the natural frequency of oscillation of water clusters and, presumably, the effect of UHF on structure of LPS mediates through the changes in water-salt environment. Under these conditions, properties of water molecules of hydration and possibly the properties of hydrophobic and hydrophilic regions in the molecule of LPS, which can affect the ability of toxin molecules to form aggregates change. Therefore the lipopolysaccharide structure modification may result in the change of its toxic properties.

  20. Effect of low-intensity electromagnetic radiation on structurization properties of bacterial lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Grigory E. Brill

    2014-09-01

    Full Text Available Purpose — to investigate the effects of low-intensity electromagnetic radiation on the process of dehydration selforganization of bacterial lipopolysaccharide (LPS. Material and Methods — The method of wedge dehydration has been used to study the structure formation of bacterial LPS. Image-phases analysis included their qualitative characteristics, as well as the calculation of quantitative indicators, followed by statistical analysis. Results — Low-intensity ultra high frequency (UHF radiation (1 GHz, 0.1 μW/cm2, 10 min has led to the changes in the suspension system of the LPS-saline reflected in the kinetics of structure formation. Conclusion — 1 GHz corresponds to the natural frequency of oscillation of water clusters and, presumably, the effect of UHF on structure of LPS mediates through the changes in water-salt environment. Under these conditions, properties of water molecules of hydration and possibly the properties of hydrophobic and hydrophilic regions in the molecule of LPS, which can affect the ability of toxin molecules to form aggregates change. Therefore the LPS structure modification may result in the change of its toxic properties.

  1. Impaired production of proinflammatory cytokines in response to lipopolysaccharide (LPS) stimulation in elderly humans

    DEFF Research Database (Denmark)

    Bruunsgaard, H.; Pedersen, Agnes Nadelmann; Schroll, M.

    1999-01-01

    Ageing is associated with decreased resistance to bacterial infections and concomitant increased circulating levels of inflammatory cytokines. The purpose of the present study was to research age-related changes in levels of early mediators of the acute-phase response in whole blood supernatants...... following LPS stimulation, representing an ex vivo model of sepsis. Levels of tumour necrosis factor-alpha (TNF-alpha), IL-1 beta and IL-6 in whole blood supernatants were measured after in vitro LPS stimulation for 24 h in 168 elderly humans aged 81 years from the 1914 cohort in Glostrup, Denmark and in 91...... of proinflammatory cytokines compared with young men, but this difference was blurred by ageing. No relation was found between circulating plasma levels of TNF-alpha and levels after in vitro LPS stimulation. In conclusion, decreased production of TNF-alpha and IL-1 beta after exposure to LPS may reflect impaired...

  2. Cerebral Metabolic Changes Related to Oxidative Metabolism in a Model of Bacterial Meningitis Induced by Lipopolysaccharide

    DEFF Research Database (Denmark)

    Munk, Michael; Rom Poulsen, Frantz; Larsen, Lykke

    2018-01-01

    BACKGROUND: Cerebral mitochondrial dysfunction is prominent in the pathophysiology of severe bacterial meningitis. In the present study, we hypothesize that the metabolic changes seen after intracisternal lipopolysaccharide (LPS) injection in a piglet model of meningitis is compatible...... with mitochondrial dysfunction and resembles the metabolic patterns seen in patients with bacterial meningitis. METHODS: Eight pigs received LPS injection in cisterna magna, and four pigs received NaCl in cisterna magna as a control. Biochemical variables related to energy metabolism were monitored by intracerebral...... dysfunction with increasing cerebral LPR due to increased lactate and normal pyruvate, PbtO2, and ICP. The metabolic pattern resembles the one observed in patients with bacterial meningitis. Metabolic monitoring in these patients is feasible to monitor for cerebral metabolic derangements otherwise missed...

  3. Effects of LPS on the behavioural stress response of genetically selected aggressive and nonaggressive wild house mice

    NARCIS (Netherlands)

    Gasparotto, O. C.; Carobrez, S. G.; Bollus, B. G. J.

    2007-01-01

    The bacterial endotoxin lipopolysaccharide (LPS) exerts strong effects on the immune-neuroendocrine network. On behaviour, LPS induces the symptoms of sickness behaviour. Otherwise, LPS challenge shares with psychological stress some common physiological adaptations. The proposal of this study was

  4. Opposing effects of cationic antimicrobial peptides and divalent cations on bacterial lipopolysaccharides

    Science.gov (United States)

    Smart, Matthew; Rajagopal, Aruna; Liu, Wing-Ki; Ha, Bae-Yeun

    2017-10-01

    The permeability of the bacterial outer membrane, enclosing Gram-negative bacteria, depends on the interactions of the outer, lipopolysaccharide (LPS) layer, with surrounding ions and molecules. We present a coarse-grained model for describing how cationic amphiphilic molecules (e.g., antimicrobial peptides) interact with and perturb the LPS layer in a biologically relevant medium, containing monovalent and divalent salt ions (e.g., Mg2+). In our approach, peptide binding is driven by electrostatic and hydrophobic interactions and is assumed to expand the LPS layer, eventually priming it for disruption. Our results suggest that in parameter ranges of biological relevance (e.g., at micromolar concentrations) the antimicrobial peptide magainin 2 effectively disrupts the LPS layer, even though it has to compete with Mg2+ for the layer. They also show how the integrity of LPS is restored with an increasing concentration of Mg2+. Using the approach, we make a number of predictions relevant for optimizing peptide parameters against Gram-negative bacteria and for understanding bacterial strategies to develop resistance against cationic peptides.

  5. Bacterial lipopolysaccharide promotes profibrotic activation of intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts play a critical role in intestinal wound healing. Lipopolysaccharide (LPS) is a cell wall component of commensal gut bacteria. The effects of LPS on intestinal fibroblast activation were characterized. METHODS: Expression of the LPS receptor, toll-like receptor (TLR) 4, was assessed in cultured primary human intestinal fibroblasts using flow cytometry and confocal microscopy. Fibroblasts were treated with LPS and\\/or transforming growth factor (TGF) beta1. Nuclear factor kappaB (NFkappaB) pathway activation was assessed by inhibitory kappaBalpha (IkappaBalpha) degradation and NFkappaB promoter activity. Fibroblast contractility was measured using a fibroblast-populated collagen lattice. Smad-7, a negative regulator of TGF-beta1 signalling, and connective tissue growth factor (CTGF) expression were assessed using reverse transcriptase-polymerase chain reaction and western blot. The NFkappaB pathway was inhibited by IkappaBalpha transfection. RESULTS: TLR-4 was present on the surface of intestinal fibroblasts. LPS treatment of fibroblasts induced IkappaBalpha degradation, enhanced NFkappaB promoter activity and increased collagen contraction. Pretreatment with LPS (before TGF-beta1) significantly increased CTGF production relative to treatment with TGF-beta1 alone. LPS reduced whereas TGF-beta1 increased smad-7 expression. Transfection with an IkappaBalpha plasmid enhanced basal smad-7 expression. CONCLUSION: Intestinal fibroblasts express TLR-4 and respond to LPS by activating NFkappaB and inducing collagen contraction. LPS acts in concert with TGF-beta1 to induce CTGF. LPS reduces the expression of the TGF-beta1 inhibitor, smad-7.

  6. Effect of lipopolysaccharide (LPS) from Ochrobactrum intermedium on sheep experimentally infected with Fasciola hepatica.

    Science.gov (United States)

    Martínez-Pérez, J M; Robles-Pérez, D; Valcárcel-Sancho, F; González-Guirado, A M; de Castro, I Casanova-García; Nieto-Martínez, J M; Rojo-Vázquez, F A; Martínez-Valladares, M

    2013-08-01

    The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium was evaluated in sheep experimentally infected with Fasciola hepatica. Animals were divided into four groups: two treated with the LPS (T1/T2) and two controls (C1/C2). T1/C1 were slaughtered at 30 days postinfection (dpi) and T2/C2 at 85 dpi. Body weight and body condition were found higher in T1 and T2 than in controls, although differences were not significant. Treated sheep showed lower cumulative fecal egg count than controls (p hepatic enzymes, although gamma-glutamyl transferase and aspartate aminotransferase values were higher in C2, and alanine aminotransferase was higher in T2. At necropsy, the mean weight of liver, fibrosis in portal triads, and ganglion size were similar in all groups. The number and size of flukes was greater in C2 than in T2 (p < 0.05). The histological examinations revealed a higher degree of parenchymatous fibrosis in T2 compared to C2 (p < 0.05). The administration of LPS from O. intermedium increased the nonspecific resistance against F. hepatica in experimentally infected sheep.

  7. Cannabidiol (CBD) enhances lipopolysaccharide (LPS)-induced pulmonary inflammation in C57BL/6 mice.

    Science.gov (United States)

    Karmaus, Peer W F; Wagner, James G; Harkema, Jack R; Kaminski, Norbert E; Kaplan, Barbara L F

    2013-01-01

    Cannabidiol (CBD) is a plant-derived cannabinoid that has been predominantly characterized as anti-inflammatory. However, it is clear that immune effects of cannabinoids can vary with cannabinoid concentration, or type or magnitude of immune stimulus. The present studies demonstrate that oral administration of CBD enhanced lipopolysaccharide (LPS)-induced pulmonary inflammation in C57BL/6 mice. The enhanced inflammatory cell infiltrate as observed in bronchoalveolar lavage fluid (BALF) was comprised mainly of neutrophils, with some monocytes. Concomitantly, CBD enhanced pro-inflammatory cytokine mRNA production, including tumor necrosis factor-α (Tnfa), interleukins (IL)-5 and -23 (Il6, Il23), and granulocyte colony stimulating factor (Gcsf). These results demonstrate that the CBD-mediated enhancement of LPS-induced pulmonary inflammation is mediated at the level of transcription of a variety of pro-inflammatory genes. The significance of these studies is that CBD is part of a therapeutic currently in use for spasticity and pain in multiple sclerosis patients, and therefore it is important to further understand mechanisms by which CBD alters immune function.

  8. The lipopolysaccharide (LPS) of Photorhabdus luminescens TT01 can elicit dose- and time-dependent immune priming in Galleria mellonella larvae.

    Science.gov (United States)

    Wu, Gongqing; Yi, Yunhong; Lv, Yingying; Li, Mei; Wang, Jia; Qiu, Lihong

    2015-05-01

    In this work, we primed Galleria mellonella larvae by haemocoel injection of lipopolysaccharide (LPS) extracted from Photorhabdus luminescens TT01 to determine whether bacterial LPS can induce enhanced immune protection (recently called immune priming). We also analyzed the relationship between changes in the levels of innate immune elements and the degree of enhanced immune protection in the larvae at designated time points after priming. The larvae that received experimental doses (20.0, 10.0 and 5.0μg per larva) of LPS demonstrated increased resistance against lethal challenge with P. luminescens TT01; the degree and period of protection correlated positively with the priming dose. These results indicated that the P. luminescens TT01 LPS could induce typical immune priming in G. mellonella. Moreover, the levels of innate immune parameters (i.e. haemocyte density, phagocytosis, haemocyte encapsulation ability, and antibacterial activity of cell-free haemolymph) and endogenous enzyme activities (i.e. acid phosphatase, ACP; alkaline phosphatase, AKP; superoxide dismutase, SOD and lysozyme, LSZ) were significantly increased following priming of the larvae with LPS, whereas the activities of peroxidase (POD) and catalase (CAT) were significantly decreased. All of the parameters examined changed in a dose- and time-dependent manner. This study demonstrated that G. mellonella larvae could modulate their immune responses based on different doses of LPS used for priming, and that priming phenomenon in G. mellonella larvae elicited by LPS was mediated by the innate immune elements and enzyme activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Epidural analgesia with morphine or buprenorphine in ponies with lipopolysaccharide (LPS)-induced carpal synovitis.

    Science.gov (United States)

    Freitas, Gabrielle C; Carregaro, Adriano B; Gehrcke, Martielo I; De La Côrte, Flávio D; Lara, Valéria M; Pozzobon, Ricardo; Brass, Karin E

    2011-04-01

    This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 μg/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 μg/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopolysaccharide (LPS) in the left or right radiocarpal joint. An epidural catheter was later introduced in the lumbosacral space and advanced up to the thoracolumbar level. The treatment started 6 h after synovitis induction. Lameness, maximum angle of carpal flexion, heart rate, systolic arterial pressure, respiratory rate, temperature, and intestinal motility were evaluated before LPS injection (baseline), 6 h after LPS injection (time 0), and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, and 24 h after treatments. Although the model of synovitis produced clear clinical signs of inflammation, the lameness scores in group C were different from the baseline for only up to 12 h. Both morphine and buprenorphine showed a reduction in the degree of lameness starting at 0.5 and 6 h, respectively. Reduced intestinal motility was observed at 0.5 h in group M and at 0.5 to 1 h in group B. Epidural morphine was a more effective analgesic that lasted for more than 12 h and without side effects. It was concluded that morphine would be a valuable analgesic option to alleviate joint pain in the thoracic limbs in ponies.

  10. Lipopolysaccharide (LPS) inner-core phosphates are required for complete LPS synthesis and transport to the outer membrane in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Delucia, Angela M; Six, David A; Caughlan, Ruth E; Gee, Patricia; Hunt, Ian; Lam, Joseph S; Dean, Charles R

    2011-01-01

    Gram-negative outer membrane (OM) integrity is maintained in part by Mg(2+) cross-links between phosphates on lipid A and on core sugars of adjacent lipopolysaccharide (LPS) molecules. In contrast to other Gram-negative bacteria, waaP, encoding an inner-core kinase, could not be inactivated in Pseudomonas aeruginosa. To examine this further, expression of the kinases WaaP or WapP/WapQ/PA5006 was placed under the control of the arabinose-regulated pBAD promoter. Growth of these strains was arabinose dependent, confirming that core phosphorylation is essential in P. aeruginosa. Transmission electron micrographs of kinase-depleted cells revealed marked invaginations of the inner membrane. SDS-PAGE of total LPS from WaaP-depleted cells showed accumulation of a fast-migrating band. Mass spectrometry (MS) analysis revealed that LPS from these cells exhibits a unique truncated core consisting of two 3-deoxy-d-manno-octulosonic acids (Kdo), two l-glycero-d-manno-heptoses (Hep), and one hexose but completely devoid of phosphates, indicating that phosphorylation by WaaP is necessary for subsequent core phosphorylations. MS analysis of lipid A from WaaP-depleted cells revealed extensive 4-amino-4-deoxy-l-arabinose modification. OM prepared from these cells by Sarkosyl extraction of total membranes or by sucrose density gradient centrifugation lacked truncated LPS. Instead, truncated LPS was detected in the inner membrane fractions, consistent with impaired transport/assembly of this species into the OM. IMPORTANCE Gram-negative bacteria have an outer membrane (OM) comprised of a phospholipid inner leaflet and a lipopolysaccharide (LPS) outer leaflet. The OM protects cells from toxic molecules and is important for survival during infection. The LPS core kinase gene waaP can be deleted in several Gram-negative bacteria but not in Pseudomonas aeruginosa. We used a controlled-expression system to deplete WaaP directly in P. aeruginosa cells, which halted growth. WaaP depletion

  11. Cerebral Metabolic Changes Related to Oxidative Metabolism in a Model of Bacterial Meningitis Induced by Lipopolysaccharide.

    Science.gov (United States)

    Munk, M; Poulsen, F R; Larsen, L; Nordström, C H; Nielsen, T H

    2018-03-05

    Cerebral mitochondrial dysfunction is prominent in the pathophysiology of severe bacterial meningitis. In the present study, we hypothesize that the metabolic changes seen after intracisternal lipopolysaccharide (LPS) injection in a piglet model of meningitis is compatible with mitochondrial dysfunction and resembles the metabolic patterns seen in patients with bacterial meningitis. Eight pigs received LPS injection in cisterna magna, and four pigs received NaCl in cisterna magna as a control. Biochemical variables related to energy metabolism were monitored by intracerebral microdialysis technique and included interstitial glucose, lactate, pyruvate, glutamate, and glycerol. The intracranial pressure (ICP) and brain tissue oxygen tension (PbtO 2 ) were also monitored along with physiological variables including mean arterial pressure, blood glucose, lactate, and partial pressure of O 2 and CO 2 . Pigs were monitored for 60 min at baseline and 240 min after LPS/NaCl injection. After LPS injection, a significant increase in cerebral lactate/pyruvate ratio (LPR) compared to control group was registered (p = 0.01). This increase was due to a significant increased lactate with stable and normal values of pyruvate. No significant change in PbtO 2 or ICP was registered. No changes in physiological variables were observed. The metabolic changes after intracisternal LPS injection is compatible with disturbance in the oxidative metabolism and partly due to mitochondrial dysfunction with increasing cerebral LPR due to increased lactate and normal pyruvate, PbtO 2 , and ICP. The metabolic pattern resembles the one observed in patients with bacterial meningitis. Metabolic monitoring in these patients is feasible to monitor for cerebral metabolic derangements otherwise missed by conventional intensive care monitoring.

  12. Anti-LPS factor in the horseshoe crab, Tachypleus tridentatus. Its hemolytic activity on the red blood cell sensitized with lipopolysaccharide.

    Science.gov (United States)

    Ohashi, K; Niwa, M; Nakamura, T; Morita, T; Iwanaga, S

    1984-10-15

    Anti-LPS factor, which inhibits the endotoxin mediated coagulation system in the horseshoe crab, Tachypleus tridentatus, was found to lyse red blood cells sensitized with gram-negative bacterial LPS, but not to lyse unsensitized cells. This hemolysis occurred even at 0 degree C and was completed within 1 min. The binding of anti-LPS factor to LPS must be essential for the hemolysis, because free LPS inhibited the hemolytic action of anti-LPS factor.

  13. Increased circulatory levels of lipopolysaccharide (LPS) and zonulin signify novel biomarkers of proinflammation in patients with type 2 diabetes.

    Science.gov (United States)

    Jayashree, B; Bibin, Y S; Prabhu, D; Shanthirani, C S; Gokulakrishnan, K; Lakshmi, B S; Mohan, V; Balasubramanyam, M

    2014-03-01

    Emerging data indicate that gut-derived endotoxin (metabolic endotoxemia) may contribute to low-grade systemic inflammation in insulin-resistant states. Specific gut bacteria seem to serve as lipopolysaccharide (LPS) sources and several reports claim a role for increased intestinal permeability in the genesis of metabolic disorders. Therefore, we investigated the serum levels of LPS and zonulin (ZO-1, a marker of gut permeability) along with systemic levels of tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) in patients with type 2 diabetes mellitus (T2DM) compared to control subjects. Study subjects were recruited from the Chennai Urban Rural Epidemiology Study [CURES], Chennai, India. Study group (n = 45 each) comprised of a) subjects with normal glucose tolerance (NGT) and (b) patients with T2DM. LPS, ZO-1, TNF-α, and IL-6 levels were measured by ELISA. Serum levels of LPS [p < 0.05], LPS activity [p < 0.001], ZO-1 [p < 0.001], TNFα [p < 0.001], and IL-6 [p < 0.001] were significantly increased in patients with T2DM compared to control subjects. Pearson correlation analysis revealed that LPS activity was significantly and positively correlated with ZO-1, fasting plasma glucose, 2 h post glucose, HbA1c, serum triglycerides, TNF-α, IL-6, and negatively correlated with HDL cholesterol. Regression analysis showed that increased LPS levels were significantly associated with type 2 diabetes [odds ratio (OR) 13.43, 95 % CI 1.998-18.9; p = 0.003]. In Asian Indians who are considered highly insulin resistant, the circulatory LPS levels, LPS activity, and ZO-1 were significantly increased in patients with type 2 diabetes and showed positive correlation with inflammatory markers and poor glycemic/lipid control.

  14. Induction of Callose Deposition in Tobacco (Nicotiana tabacum by Bacterial Lipopolysaccharide Pseudomonas syringae pv. tabaci and Pseudomonas syringae pv. glycinea

    Directory of Open Access Journals (Sweden)

    Pipit Marianingsih

    2014-12-01

    Full Text Available Lipopolysaccharide (LPS is a major component of outer-membrane gram-negative bacteria, and it can act as a Pathogen-Associated Molecular Pattern (PAMP for perception of pathogens by plants. LPS can be recognized by plants, triggering certain plant defense-related responses, including callose deposition. This study investigated induction of callose deposition by bacterial LPS in tobacco. Tobacco leaves were infiltrated with 400 μg/mL and 800 μg/mL LPS extracted from Pseudomonas syringae pv. tabaci (Pta and Pseudomonas syringae pv. glycinea (Pgl and incubated for 24 h or 48 h. To detect callose deposition, tobacco leaves were cleared in lactophenol solution, stained with aniline blue, and visualized by fluorescence microscopy. Results showed that LPS from Pgl induced more callose deposition in tobacco leaves than did that from Pta. In addition, a Pearson correlation test revealed that incubation period was the most significant factor in callose deposition, followed by the type of LPS bacteria. However, LPS concentration was not significantly corelated to callose deposition in tobacco leaves.

  15. Sheep lung segmental delivery strategy demonstrates adenovirus priming of local lung responses to bacterial LPS and the role of elafin as a response modulator.

    Science.gov (United States)

    Brown, Thomas I; Collie, David S; Shaw, Darren J; Rzechorzek, Nina M; Sallenave, Jean-Michel

    2014-01-01

    Viral lung infections increase susceptibility to subsequent bacterial infection. We questioned whether local lung administration of recombinant adenoviral vectors in the sheep would alter the susceptibility of the lung to subsequent challenge with bacterial lipopolysaccharide (LPS). We further questioned whether local lung expression of elafin, a locally produced alarm anti-LPS/anti-bacterial molecule, would modulate the challenge response. We established that adenoviral vector treatment primed the lung for an enhanced response to bacterial LPS. Whereas this local effect appeared to be independent of the transgene used (Ad-o-elafin or Ad-GFP), Ad-o-elafin treated sheep demonstrated a more profound lymphopenia in response to local lung administration of LPS. The local influence of elafin in modulating the response to LPS was restricted to maintaining neutrophil myeloperoxidase activity, and levels of alveolar macrophage and neutrophil phagocytosis at higher levels post-LPS. Adenoviral vector-bacterial synergism exists in the ovine lung and elafin expression modulates such synergism both locally and systemically.

  16. Structural modifications of bacterial lipopolysaccharide that facilitate Gram-negative bacteria evasion of host innate immunity

    Directory of Open Access Journals (Sweden)

    Motohiro eMatsuura

    2013-05-01

    Full Text Available Bacterial lipopolysaccharide (LPS, a cell wall component characteristic of Gram-negative bacteria, is a representative pathogen-associated molecular pattern that allows mammalian cells to recognize bacterial invasion and trigger innate immune responses. The polysaccharide moiety of LPS primary plays protective roles for bacteria such as prevention from complement attacks or camouflage with common host carbohydrate residues. The lipid moiety, termed lipid A, is recognized by the Toll-like receptor 4 (TLR4/MD-2 complex, which transduces signals for activation of host innate immunity. The basic structure of lipid A is a glucosamine disaccharide substituted by phosphate groups and acyl groups. Lipid A with 6 acyl groups (hexa-acylated form has been indicated to be a strong stimulator of the TLR4/MD-2 complex. This type of lipid A is conserved among a wide variety of Gram-negative bacteria, and those bacteria are easily recognized by host cells for activation of defensive innate immune responses. Modifications of the lipid A structure to less-acylated forms have been observed in some bacterial species, and those forms are poor stimulators of the TLR4/MD-2 complex. Such modifications are thought to facilitate bacterial evasion of host innate immunity, thereby enhancing pathogenicity. This hypothesis is supported by studies of Yersinia pestis LPS, which contains hexa-acylated lipid A when the bacterium grows at 27ºC (the temperature of the vector flea, and shifts to contain less-acylated forms when grown at the human body temperature of 37ºC. This alteration of lipid A forms following transmission of Y. pestis from fleas to humans contributes predominantly to the virulence of this bacterium over other virulence factors. A similar role for less-acylated lipid A forms has been indicated in some other bacterial species, such as Francisella tularensis, Helicobacter pylori, and Porphyromonas gingivalis, and further studies to explore this concept are

  17. Effects of L-proline on the Growth Performance, and Blood Parameters in Weaned Lipopolysaccharide (LPS-challenged Pigs

    Directory of Open Access Journals (Sweden)

    Ping Kang

    2014-08-01

    Full Text Available This trail was conducted to study the effect of L-proline on the growth performance, and blood parameter in the weaned lipopolysaccharide (LPS-challenged pigs. Thirty six pigs (9.13±0.85 kg were assigned randomly to dietary treatments in a 2×3 factorial arrangement in a 20-d growth assay. Factors were intraperitoneal injection with saline or LPS, and three dietary L-proline supplement levels (0%, 0.5%, or 1.0%. On d 10, blood samples were collected at 3 h after LPS (100 μg LPS/kg body weight [BW] or saline injection. On d 20 of the trial, all pigs were orally administrated D-xylose (0.1 g/kg BW at 2 h, and blood samples were collected at 3 h after LPS or saline injection. As a result, dietary supplementation with 0.5% proline had a tendency to increase average daily gain (ADG in piglets during d 10 to 20 (p = 0.088. Without LPS challenge, dietary supplementation with 1.0% proline had no effect on growth hormone (GH concentrations on d 10 (p>0.05, but decreased it after LPS challenge (p<0.05. There was LPS challenge×proline interaction for GH concentrations on d 10 (p<0.05. Dietary supplementation with 1.0% proline decreased glucagon concentration on d 10 after LPS challenge (p<0.05. In addition, dietary supplementation with proline increased superoxide dismutase (SOD activity significantly on d 10 and 20 (p<0.05, and 1.0% proline increased heat shock proteins-70 concentration on d 10 (p<0.05. Moreover, proline supplementation increased diamine oxidase (DAO concentrations after LPS challenge (p<0.05. There was LPS challenge×proline interaction for DAO (p<0.05. Furthermore, dietary supplementation with 1.0% proline increased the D-xylose level when no LPS challenge (p<0.05. These results indicate that proline supplementation could improve growth performance, increase SOD activities, and has a positive effect on the gastrointestinal tract digestibility in early weaned pigs.

  18. Stress hormone release is a key component of the metabolic response to lipopolysaccharide (LPS)

    DEFF Research Database (Denmark)

    Bach, Ermina; Møller, Andreas Buch; Jorgensen, Jens Otto L

    2016-01-01

    on glucose, protein and lipid metabolism in eight HP and eight matched CTR twice during 4-h basal and 2-h hyperinsulinemic euglycemic clamp conditions with muscle biopsies and fat biopsies in each period during infusion with saline or LPS. RESULTS: LPS increased cortisol and growth hormone (GH) levels in CTR...... of stress hormones. We compared the metabolic effects of LPS in hypopituitary patients (HP) (in the absence of pituitary stress hormone responses) and healthy control subjects (CTR) (with normal pituitary stress hormone responses). DESIGN: Single blind randomized. METHODS: We compared effects of LPS...... pituitary function and appropriate cortisol and GH release are crucial components of the metabolic response to LPS....

  19. Bartonella quintana lipopolysaccharide (LPS): structure and characteristics of a potent TLR4 antagonist for in-vitro and in-vivo applications

    Science.gov (United States)

    Malgorzata-Miller, Gosia; Heinbockel, Lena; Brandenburg, Klaus; van der Meer, Jos W. M.; Netea, Mihai G.; Joosten, Leo A. B.

    2016-01-01

    The pattern recognition receptor TLR4 is well known as a crucial receptor during infection and inflammation. Several TLR4 antagonists have been reported to inhibit the function of TLR4. Both natural occurring antagonists, lipopolysaccharide (LPS) from Gram-negative bacteria as well as synthetic compounds based on the lipid A structure of LPS have been described as potent inhibitors of TLR4. Here, we have examined the characteristics of a natural TLR4 antagonist, isolated from Bartonella quintana bacterium by elucidating its chemical primary structure. We have found that this TLR4 antagonist is actually a lipooligosaccharide (LOS) instead of a LPS, and that it acts very effective, with a high inhibitory activity against triggering by the LPS-TLR4 system in the presence of a potent TLR4 agonist (E. coli LPS). Furthermore, we demonstrate that B. quintana LPS is not inactivated by polymyxin B, a classical cyclic cationic polypeptide antibiotic that bind the lipid A part of LPS, such as E. coli LPS. Using a murine LPS/D-galactosamine endotoxaemia model we showed that treatment with B. quintana LPS could improve the survival rate significantly. Since endogenous TLR4 ligands have been associated with several inflammatory- and immune-diseases, B. quintana LPS might be a novel therapeutic strategy for TLR4-driven pathologies. PMID:27670746

  20. Lipopolysaccharide-binding proteins of Limulus amebocyte lysate.

    OpenAIRE

    Roth, R I; Tobias, P S

    1993-01-01

    Limulus amebocyte lysate, obtained from horseshoe crab (Limulus polyphemus) blood cells, contains a coagulation system which is activated by bacterial lipopolysaccharide (LPS). A chromatographic fraction of Limulus lysate, containing the endotoxin-sensitive factor(s) which initiates the coagulation cascade, was studied. We utilized a photoreactive, cleavable, radiolabeled derivative of Salmonella minnesota LPS, LPS-(p-azidosalicylamido)-1,3'-dithiopropionamide (LPS-ASD), to identify LPS-bindi...

  1. The Anti-Inflammatory Effect of Algae-Derived Lipid Extracts on Lipopolysaccharide (LPS)-Stimulated Human THP-1 Macrophages.

    Science.gov (United States)

    Robertson, Ruairi C; Guihéneuf, Freddy; Bahar, Bojlul; Schmid, Matthias; Stengel, Dagmar B; Fitzgerald, Gerald F; Ross, R Paul; Stanton, Catherine

    2015-08-20

    Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%-42% total fatty acids as n-3 PUFA and 5%-7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases.

  2. Effect of Bacterial Lipopolysaccharide Contamination on Gutta Percha- versus Resilon-Induced Human Monocyte Cell Line Toxicity.

    Directory of Open Access Journals (Sweden)

    Jamshid Hadjati

    2015-04-01

    Full Text Available Cytotoxic effects of obturation materials were tested in presence and absence of endotoxin on human monocytes in vitro.Human monocytes from THP-1 cell line were cultured. Three millimeters from the tip of each Resilon and gutta percha points were cut and directly placed at the bottom of the culture wells. Cultured cells were exposed to gutta percha (groups G1 and G2 and Resilon (R1 and R2. Ten μg/ml bacterial lipopolysaccharide (LPS was added to the culture wells in groups G1 and R1. Positive control included the bacterial LPS without the root canal filling material and the negative control contained the cells in culture medium only. Viability of cells was tested in all groups after 24, 48, and 72 hours using the methylthiazolyldiphenyl-tetrazolium bromide (MTT assay for at least 3 times to obtain reproducible results. Optical density values were read and the data were analyzed using three-way ANOVA and post hoc statistical test.The results showed that cells in G2 had the lowest rate of viability at 24 hours, but the lowest rate of viable cells was recorded in G1 at 48 and 72 hours. The effect of LPS treatment was not statistically significant. Resilon groups showed cell viability values higher than those of gutta percha groups, although statistically non-significant (P=0.105. Cell viability values were lower in gutta percha than Resilon groups when LPS-treated and LPS-untreated groups were compared independently at each time point.It could be concluded that none of the tested root canal filling materials had toxic effects on cultured human monocyte cells whether in presence or absence of LPS contamination.

  3. Prostaglandin E2 and thromboxane B2 release from human monocytes treated with bacterial lipopolysaccharide

    International Nuclear Information System (INIS)

    Nichols, F.C.; Garrison, S.W.; Davis, H.W.

    1988-01-01

    We investigated the capacity of counterflow-isolated human monocytes to independently synthesize thromboxane B2 (TxB2) and prostaglandin E2 (PGE2) when stimulated with bacterial lipopolysaccharide (LPS). Independent metabolism was confirmed by establishing different specific activities (dpm/ng) of TxB2 and PGE2 released from LPS-treated cells. For metabolites released during the initial 2-hr treatment period, the specific activity of PGE2 was approximately threefold higher than that of TxB2 regardless of labeling with [3H]arachidonic acid (AA) or [14C]AA. Cells that were pulse-labeled for 2 hr with [3H]AA demonstrated a decreasing PGE2 specific activity over 24 hr, whereas the TxB2 specific activity remained unchanged. In contrast, cells continuously exposed to [14C]AA demonstrated an increasing TxB2 specific activity that approached the level of PGE2 by 24 hr. These results suggest the presence of at least 2 cyclooxygenase metabolic compartments in counterflow-isolated monocytes. Although freshly isolated monocytes have been reported to contain variable numbers of adherent platelets, additional experiments demonstrated that counterflow-isolated platelets are not capable of releasing elevated levels of TxB2 or PGE2 when treated with LPS. It is proposed from these findings that at least two subsets of monocytes exist in peripheral blood that can be distinguished on the basis of independent conversion of AA to TxB2 and PGE2

  4. Activation of inflammatory immune gene cascades by lipopolysaccharide (LPS) in the porcine colonic tissue ex-vivo model.

    Science.gov (United States)

    Bahar, B; O'Doherty, J V; Vigors, S; Sweeney, T

    2016-11-01

    The technique of challenging postmortem tissue explants with inflammation inducer such as lipopolysaccharide (LPS) followed by gene expression analysis is used widely for evaluating the immune-suppressing effect of bioactives. Using porcine colonic tissue as an ex-vivo model of mammalian intestinal gut, this study evaluated the effect of incubation time on the integrity of gene transcripts and activation of inflammatory immune gene cascade by LPS treatment. Post-slaughter colon was removed surgically and explants were incubated for 0, 3, 6 and 12 h and the abundance of mRNA transcripts of a panel of 92 immune genes were evaluated using quantitative polymerase chain reaction (qPCR) arrays. The mRNA transcripts were highly intact after 0 and 3 h of incubation; however, after 6 h the degradation was clearly evident. Following 3 h incubation, 98·8% and 100% mRNA transcripts were detectable in the colonic tissue harvested from weaned and mature pigs, respectively. In the explants of weaned piglets, LPS treatment activated inflammatory signalling pathways [high mobility group B1 (HMGB1), dendritic cell maturation, interleukin (IL)-6, IL-8, IL-17F], while these pathways were inhibited by dexamethasone treatment. Activations of inflammatory genes were also evident in the explants collected from the mature pigs subjected to ex-vivo incubation for 3 h in the absence or presence of LPS. It is concluded that the colonic explant remains physiologically viable and responsive to immunological challenge for up to 3 h ex-vivo. © 2016 British Society for Immunology.

  5. Bartonella quintana lipopolysaccharide (LPS): structure and characteristics of a potent TLR4 antagonist for in-vitro and in-vivo applications

    NARCIS (Netherlands)

    Malgorzata-Miller, G.; Heinbockel, L.; Brandenburg, K.; Meer, J.W.M. van der; Netea, M.G.; Joosten, L.A.B.

    2016-01-01

    The pattern recognition receptor TLR4 is well known as a crucial receptor during infection and inflammation. Several TLR4 antagonists have been reported to inhibit the function of TLR4. Both natural occurring antagonists, lipopolysaccharide (LPS) from Gram-negative bacteria as well as synthetic

  6. Chromium supplementation enhances the metabolic response of steers to lipopolysaccharide (LPS) challenge

    Science.gov (United States)

    The effect of chromium (Cr; KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) supplementation on the metabolic response to LPS challenge was examined. Steers (n=20; 235±4 kg body weight (BW)) received a premix that added 0 (Con) or 0.2 mg/kg Cr to the total diet (DM (dry matter) basis) for ...

  7. Chromium supplementation enhances the acute phase response of steers to a lipopolysaccharide (LPS) challenge

    Science.gov (United States)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty crossbred steers (235±4 kg BW) received 0 ppb (Control; C) or 200 ppb chromium propionate (CHR) for 55 days. Steers were fitted with jugular catheters and rectal temperature (RT) recording...

  8. Enhancement of the acute phase response to lipopolysaccharide (LPS) challenge in steers supplemented with chromium

    Science.gov (United States)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty steers received a premix that added 0 (control) or 0.2 mg/kg of chromium (KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) to the total diet on a dry matter basis for 55 d. Steer...

  9. Effects of Acarbose Addition on Ruminal Bacterial Microbiota, Lipopolysaccharide Levels and Fermentation Characteristics

    Directory of Open Access Journals (Sweden)

    Yu-yang Yin

    2014-12-01

    Full Text Available This study investigated the effects of acarbose addition on changes in ruminal fermentation characteristics and the composition of the ruminal bacterial community in vitro using batch cultures. Rumen fluid was collected from the rumens of three cannulated Holstein cattle fed forage ad libitum that was supplemented with 6 kg of concentrate. The batch cultures consisted of 8 mL of strained rumen fluid in 40 mL of an anaerobic buffer containing 0.49 g of corn grain, 0.21 g of soybean meal, 0.15 g of alfalfa and 0.15g of Leymus chinensis. Acarbose was added to incubation bottles to achieve final concentrations of 0.1, 0.2, and 0.4 mg/mL. After incubation for 24 h, the addition of acarbose linearly decreased (p<0.05 the total gas production and the concentrations of acetate, propionate, butyrate, total volatile fatty acids, lactate and lipopolysaccharide (LPS. It also linearly increased (p<0.05 the ratio of acetate to propionate, the concentrations of isovalerate, valerate and ammonia-nitrogen and the pH value compared with the control. Pyrosequencing of the 16S rRNA gene showed that the addition of acarbose decreased (p<0.05 the proportion of Firmicutes and Proteobacteria and increased (p<0.05 the percentage of Bacteroidetes, Fibrobacteres, and Synergistetes compared with the control. A principal coordinates analysis plot based on unweighted UniFrac values and molecular variance analysis revealed that the structure of the ruminal bacterial communities in the control was different to that of the ruminal microbiota in the acarbose group. In conclusion, acarbose addition can affect the composition of the ruminal microbial community and may be potentially useful for preventing the occurrence of ruminal acidosis and the accumulation of LPS in the rumen.

  10. Lipid composition and lipopolysaccharide binding capacity of lipoproteins in plasma and lymph of patients with systemic inflammatory response syndrome and multiple organ failure

    NARCIS (Netherlands)

    Levels, Johannes H. M.; Lemaire, Luciënne C. J. M.; van den Ende, Abraham E.; van Deventer, Sander J. H.; van Lanschot, J. Jan B.

    2003-01-01

    Background. Lipopolysaccharide (LPS), the major glycolipid component of Gram-negative bacterial outer membranes, is a potent endotoxin responsible for many of the directly or indirectly induced symptoms of infection. Lipoproteins (in particular, high-density lipoproteins) sequester LPS, thereby

  11. Patterns of Transcriptional Response to 1,25-Dihydroxyvitamin D3 and Bacterial Lipopolysaccharide in Primary Human Monocytes

    Directory of Open Access Journals (Sweden)

    Silvia N. Kariuki

    2016-05-01

    Full Text Available The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D, plays an important immunomodulatory role, regulating transcription of genes in the innate and adaptive immune system. The present study examines patterns of transcriptome-wide response to 1,25D, and the bacterial lipopolysaccharide (LPS in primary human monocytes, to elucidate pathways underlying the effects of 1,25D on the immune system. Monocytes obtained from healthy individuals of African-American and European-American ancestry were treated with 1,25D, LPS, or both, simultaneously. The addition of 1,25D during stimulation with LPS induced significant upregulation of genes in the antimicrobial and autophagy pathways, and downregulation of proinflammatory response genes compared to LPS treatment alone. A joint Bayesian analysis enabled clustering of genes into patterns of shared transcriptional response across treatments. The biological pathways enriched within these expression patterns highlighted several mechanisms through which 1,25D could exert its immunomodulatory role. Pathways such as mTOR signaling, EIF2 signaling, IL-8 signaling, and Tec Kinase signaling were enriched among genes with opposite transcriptional responses to 1,25D and LPS, respectively, highlighting the important roles of these pathways in mediating the immunomodulatory activity of 1,25D. Furthermore, a subset of genes with evidence of interethnic differences in transcriptional response was also identified, suggesting that in addition to the well-established interethnic variation in circulating levels of vitamin D, the intensity of transcriptional response to 1,25D and LPS also varies between ethnic groups. We propose that dysregulation of the pathways identified in this study could contribute to immune-mediated disease risk.

  12. Lipoteichoic Acid (LTA) and Lipopolysaccharides (LPS) from Periodontal Pathogenic Bacteria Facilitate Oncogenic Herpesvirus Infection within Primary Oral Cells

    Science.gov (United States)

    Dai, Lu; DeFee, Michael R.; Cao, Yueyu; Wen, Jiling; Wen, Xiaofei; Noverr, Mairi C.; Qin, Zhiqiang

    2014-01-01

    Kaposi’s sarcoma (KS) remains the most common tumor arising in patients with HIV/AIDS, and involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage of a variety of bacteria. Whether interactions involving pathogenic bacteria and oncogenic viruses in the local environment facilitate replication or maintenance of these viruses in the oral cavity remains unknown. In the current study, our data indicate that pretreatment of primary human oral fibroblasts with two prototypical pathogen-associated molecular patterns (PAMPs) produced by oral pathogenic bacteria–lipoteichoic acid (LTA) and lipopolysaccharide (LPS), increase KSHV entry and subsequent viral latent gene expression during de novo infection. Further experiments demonstrate that the underlying mechanisms induced by LTA and/or LPS include upregulation of cellular receptor, increasing production of reactive oxygen species (ROS), and activating intracellular signaling pathways such as MAPK and NF-κB, and all of which are closely associated with KSHV entry or gene expression within oral cells. Based on these findings, we hope to provide the framework of developing novel targeted approaches for treatment and prevention of oral KSHV infection and KS development in high-risk HIV-positive patients. PMID:24971655

  13. Lipoteichoic acid (LTA and lipopolysaccharides (LPS from periodontal pathogenic bacteria facilitate oncogenic herpesvirus infection within primary oral cells.

    Directory of Open Access Journals (Sweden)

    Lu Dai

    Full Text Available Kaposi's sarcoma (KS remains the most common tumor arising in patients with HIV/AIDS, and involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage of a variety of bacteria. Whether interactions involving pathogenic bacteria and oncogenic viruses in the local environment facilitate replication or maintenance of these viruses in the oral cavity remains unknown. In the current study, our data indicate that pretreatment of primary human oral fibroblasts with two prototypical pathogen-associated molecular patterns (PAMPs produced by oral pathogenic bacteria-lipoteichoic acid (LTA and lipopolysaccharide (LPS, increase KSHV entry and subsequent viral latent gene expression during de novo infection. Further experiments demonstrate that the underlying mechanisms induced by LTA and/or LPS include upregulation of cellular receptor, increasing production of reactive oxygen species (ROS, and activating intracellular signaling pathways such as MAPK and NF-κB, and all of which are closely associated with KSHV entry or gene expression within oral cells. Based on these findings, we hope to provide the framework of developing novel targeted approaches for treatment and prevention of oral KSHV infection and KS development in high-risk HIV-positive patients.

  14. The Anti-Inflammatory Effect of Algae-Derived Lipid Extracts on Lipopolysaccharide (LPS-Stimulated Human THP-1 Macrophages

    Directory of Open Access Journals (Sweden)

    Ruairi C. Robertson

    2015-08-01

    Full Text Available Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus and one microalga (Pavlova lutheri were assessed in lipopolysaccharide (LPS-stimulated human THP-1 macrophages. Extracts contained 34%–42% total fatty acids as n-3 PUFA and 5%–7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL-6 (p < 0.05 and IL-8 (p < 0.05 while that of P. lutheri inhibited IL-6 (p < 0.01 production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1 by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases.

  15. The Characteristics and Function of Bacterial Lipopolysaccharides and Their Endotoxic Potential in Humans.

    Science.gov (United States)

    Gnauck, Anne; Lentle, Roger G; Kruger, Marlena C

    2016-05-03

    Cross-talk between enteral microbiota and human host is essential for the development and maintenance of the human gastrointestinal and systemic immune systems. The presence of lipopolysaccharides (LPS) lysed from the cell membrane of Gram-negative bacteria in the gut lumen is thought to promote the development of a balanced gut immune response whilst the entry of the same LPS into systemic circulation may lead to a deleterious pro-inflammatory systemic immune response. Recent data suggest that chronically low levels of circulating LPS may be associated with the development of metabolic diseases such as insulin resistance, type 2 diabetes, atherosclerosis and cardiovascular disease. This review focuses on the cross-talk between enteral commensal bacteria and the human immune system via LPS. We explain the structural characterisation of the LPS molecule and its function in the bacteria. We then examine how LPS is recognised by various elements of the human immune system and the signalling pathways that are activated by the structure of the LPS molecule and the effect of various concentrations. Further, we discuss the sequelae of this signalling in the gut-associated and systemic immune systems i.e. the neutralisation of LPS and the development of tolerance to LPS.

  16. How T-cell-dependent and -independent challenges access the brain: vascular and neural responses to bacterial lipopolysaccharide and staphylococcal enterotoxin B.

    Science.gov (United States)

    Serrats, Jordi; Sawchenko, Paul E

    2009-10-01

    Bacterial lipopolysaccharide (LPS) is widely used to study immune influences on the CNS, and cerebrovascular prostaglandin (PG) synthesis is implicated in mediating LPS influences on some acute phase responses. Other bacterial products, such as staphylococcal enterotoxin B (SEB), impact target tissues differently in that their effects are T-lymphocyte-dependent, yet both LPS and SEB recruit a partially overlapping set of subcortical central autonomic cell groups. We sought to compare neurovascular responses to the two pathogens, and the mechanisms by which they may access the brain. Rats received iv injections of LPS (2 microg/kg), SEB (1mg/kg) or vehicle and were sacrificed 0.5-3h later. Both challenges engaged vascular cells as early 0.5h, as evidenced by induced expression of the vascular early response gene (Verge), and the immediate-early gene, NGFI-B. Cyclooxygenase-2 (COX-2) expression was detected in both endothelial and perivascular cells (PVCs) in response to LPS, but only in PVCs of SEB-challenged animals. The non-selective COX inhibitor, indomethacin (1mg/kg, iv), blocked LPS-induced activation in a subset of central autonomic structures, but failed to alter SEB-driven responses. Liposome mediated ablation of PVCs modulated the CNS response to LPS, did not affect the SEB-induced activational profile. By contrast, disruptions of interoceptive signaling by area postrema lesions or vagotomy (complete or hepatic) markedly attenuated SEB-, but not LPS-, stimulated central activational responses. Despite partial overlap in their neuronal and vascular response profiles, LPS and SEB appear to use distinct mechanisms to access the brain.

  17. Bacterial lipopolysaccharide induces osteoclast formation in RAW 264.7 macrophage cells

    International Nuclear Information System (INIS)

    Islam, Shamima; Hassan, Ferdaus; Tumurkhuu, Gantsetseg; Dagvadorj, Jargalsaikhan; Koide, Naoki; Naiki, Yoshikazu; Mori, Isamu; Yoshida, Tomoaki; Yokochi, Takashi

    2007-01-01

    Lipopolysaccharide (LPS) is a potent bone resorbing factor. The effect of LPS on osteoclast formation was examined by using murine RAW 264.7 macrophage cells. LPS-induced the formation of multinucleated giant cells (MGC) in RAW 264.7 cells 3 days after the exposure. MGCs were positive for tartrate-resistant acid phosphatase (TRAP) activity. Further, MGC formed resorption pits on calcium-phosphate thin film that is a substrate for osteoclasts. Therefore, LPS was suggested to induce osteoclast formation in RAW 264.7 cells. LPS-induced osteoclast formation was abolished by anti-tumor necrosis factor (TNF)-α antibody, but not antibodies to macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-κB ligand (RANKL). TNF-α might play a critical role in LPS-induced osteoclast formation in RAW 264.7 cells. Inhibitors of NF-κB and stress activated protein kinase (SAPK/JNK) prevented the LPS-induced osteoclast formation. The detailed mechanism of LPS-induced osteoclast formation is discussed

  18. Crystal structure of an endotoxin-neutralizing protein from the horseshoe crab, Limulus anti-LPS factor, at 1.5 A resolution.

    OpenAIRE

    Hoess, A; Watson, S; Siber, G R; Liddington, R

    1993-01-01

    Lipopolysaccharide (LPS), or endotoxin, is the major mediator of septic shock, a serious complication of Gram-negative bacterial infections in humans. Molecules that bind LPS and neutralize its biological effects or enhance its clearance could have important clinical applications. Limulus anti-LPS factor (LALF) binds LPS tightly, and, in animal models, reduces mortality when administered before or after LPS challenge or bacterial infection. Here we present the high resolution structure of a r...

  19. Transient Receptor Potential Ankyrin 1 (TRPA1) Mediates Lipopolysaccharide (LPS)-Induced Inflammatory Responses in Primary Human Osteoarthritic Fibroblast-Like Synoviocytes.

    Science.gov (United States)

    Yin, Songjiang; Wang, Peimin; Xing, Runlin; Zhao, Linrui; Li, Xiaochen; Zhang, Li; Xiao, Yancheng

    2018-03-01

    Transient receptor potential ankyrin 1 (TRPA1) is a membrane-associated cation channel, widely expressed in neuronal and non-neuronal cells. Recently, emerging evidences suggested the crucial role of TRPA1 in the disease progression of osteoarthritis (OA). Therefore, we aimed to investigate whether TRPA1 mediate lipopolysaccharide (LPS)-induced inflammatory responses in primary human OA fibroblast-like synoviocytes (OA-FLS). The expression of TRPA1 in LPS-treated OA-FLS was assessed by polymerase chain reaction (PCR) and western blot (WB), and the functionality of TRPA1 channel by Ca 2+ influx measurements. Meanwhile, production of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, matrix metalloproteinase (MMP)-1, and MMP-3 in LPS-treated cells was measured by immunoassay. Histological observation after inhibition of TRPA1 was also performed in rats with LPS-induced inflammatory arthritis. After being induced by LPS, the gene and protein expression of TRPA1 was increased in the time-dependent or dose-dependent manner. Meanwhile, Ca 2+ influx mediated by TRPA1 in human OA-FLS was also enhanced. In addition, pharmacological inhibition and gene silencing of TRPA1 downregulated the production of IL-1β, TNF-α, IL-6, MMP-1, and MMP-3 in LPS-treated FLS. Finally, synovial inflammation and cartilage degeneration were also reduced by the TRPA1 antagonist. We found the LPS caused the increased functional expression of TRPA1, the activation of which involved in LPS-reduced inflammatory responses in primary human OA-FLS, and the inhibition of TRPA1 produces protective effect in LPS-induced arthritis.

  20. Lipopolysaccharide regulates macrophage fluid phase pinocytosis via CD14-dependent and CD14-independent pathways

    NARCIS (Netherlands)

    Peppelenbosch, M. P.; DeSmedt, M.; ten Hove, T.; van Deventer, S. J.; Grooten, J.

    1999-01-01

    Lipopolysaccharide (LPS) is a mediator of inflammation and septic shock during bacterial infection. Although monocytes and macrophages are highly responsive to LPS, the biological effects of LPS in these cell types are only partially understood. We decided, therefore, to investigate the influence of

  1. Estimation of the in vitro eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust by using reconstituted human corneal epithelium tissue cultures

    DEFF Research Database (Denmark)

    Cao, Yi; Arenholt-Bindslev, Dorthe; Kjærgaard, Søren K

    2015-01-01

    CONTEXT: Eye irritation is a common complaint in indoor environment, but the causes have still not been identified among the multiple exposures in house environments. To identify the potential environmental factors responsible for eye irritation and study the possible mechanisms, an in vitro model...... AND CONCLUSION: LPS and dust showed in vitro eye irritating and inflammatory potential, and cytokines/chemokines like IL-1β and IL-8 may be involved in the mechanisms of eye irritation. The HCE tissue culture may be used as an in vitro model to study environmental exposure induced eye irritation and inflammation....... for eye irritation is suggested. MATERIALS AND METHODS: In this study, reconstituted human corneal epithelium (HCE) tissue cultures were used to study the eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust. HCE tissue cultures were exposed to a range of concentrations of LPS...

  2. Use of o-phthalaldehyde to detect O-phosphorylethanolamine in bacterial lipopolysaccharide.

    Science.gov (United States)

    Yeh, H Y; Price, R M; Jacobs, D M

    1992-06-01

    We have developed a method to measure O-phosphorylethanolamine groups in bacterial lipopolysaccharide using a fluorescent reagent, o-phthalaldehyde. The optimal excitation and emission wavelengths were 335 nm and 450 nm, respectively. The reaction was pH-dependent with an optimum at pH 10.5. The maximum fluorescence intensity occurred two min after mixing lipopolysaccharide with the reagent at pH 10.5. The assay was linear over a range of 1 microgram to 100 micrograms of lipopolysaccharide. When we compared the amount of primary amine (as O-phosphorylethanolamine) in native and p-hydroxyphenylacetic acid-derivatized lipopolysaccharide, we found that 97% of amine groups in native lipopolysaccharide were derivatized by p-hydroxyphenylacetic acid in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide.

  3. Importance of bacterial endotoxin (LPS in endodontics A importância da endotoxina bacteriana (LPS na endodontia atual

    Directory of Open Access Journals (Sweden)

    Mario Roberto Leonardo

    2004-06-01

    Full Text Available New knowledge of the structure and biological activity of endotoxins (LPS has revolutionized concepts concerning their mechanisms of action and forms of inactivation. Since the 1980's, technological advances in microbiological culture and identification have shown that anaerobic microorganisms, especially Gram-negative, predominate in root canals of teeth with pulp necrosis and radiographically visible chronic periapical lesions. Gram-negative bacteria not only have different factors of virulence and generate sub-products that are toxic to apical and periapical tissues, as also contain endotoxin (LPS on their cell wall. This is especially important because endotoxin is released during multiplication or bacterial death, causing a series of biological effects that lead to an inflammatory reaction and resorption of mineralized tissues. Thus, due to the role of endotoxin in the pathogenesis of periapical lesions, we reviewed the literature concerning the biological activity of endotoxin and the relevance of its inactivation during treatment of teeth with pulp necrosis and chronic periapical lesion.O conhecimento mais aprofundado sobre a estrutura e atividade biológica das endotoxinas (LPS revolucionou os conceitos sobre seu mecanismo de ação e formas de inativação. A partir da década de 80, os avanços tecnológicos na cultura e identificação microbiológica demonstraram que, em canais radiculares de dentes portadores de necrose pulpar e lesão periapical crônica, visível radiograficamente, predominam microrganismos anaeróbios, particularmente os gram-negativos. Como se sabe, os microrganismos gram-negativos, além de possuírem diferentes fatores de virulência e gerarem produtos e sub-produtos tóxicos aos tecidos apicais e periapicais, contêm endotoxina em sua parede celular. Esse conhecimento é particularmente importante, uma vez que a endotoxina é liberada durante a multiplicação ou morte bacteriana, exercendo uma série de

  4. Lipopolysaccharide (LPS)-mediated Angiopoietin-2-dependent Autocrine Angiogenesis Is Regulated by NADPH Oxidase 2 (Nox2) in Human Pulmonary Microvascular Endothelial Cells*

    Science.gov (United States)

    Menden, Heather; Welak, Scott; Cossette, Stephanie; Ramchandran, Ramani; Sampath, Venkatesh

    2015-01-01

    Sepsis-mediated endothelial Angiopoeitin-2 (Ang2) signaling may contribute to microvascular remodeling in the developing lung. The mechanisms by which bacterial cell wall components such as LPS mediate Ang2 signaling in human pulmonary microvascular endothelial cells (HPMECs) remain understudied. In HPMEC, LPS-induced Ang2, Tie2, and VEGF-A protein expression was preceded by increased superoxide formation. NADPH oxidase 2 (Nox2) inhibition, but not Nox4 or Nox1 inhibition, attenuated LPS-induced superoxide formation and Ang2, Tie2, and VEGF-A expression. Nox2 silencing, but not Nox4 or Nox1 silencing, inhibited LPS-mediated inhibitor of κ-B kinase β (IKKβ) and p38 phosphorylation and nuclear translocation of NF-κB and AP-1. In HPMECs, LPS increased the number of angiogenic tube and network formations in Matrigel by >3-fold. Conditioned media from LPS-treated cells also induced angiogenic tube and network formation in the presence of Toll-like receptor 4 blockade but not in the presence of Ang2 and VEGF blockade. Nox2 inhibition or conditioned media from Nox2-silenced cells attenuated LPS-induced tube and network formation. Ang2 and VEGF-A treatment rescued angiogenesis in Nox2-silenced cells. We propose that Nox2 regulates LPS-mediated Ang2-dependent autocrine angiogenesis in HPMECs through the IKKβ/NF-κB and MAPK/AP-1 pathways. PMID:25568324

  5. Lipopolysaccharide recognition, internalisation, signalling and other cellular effects

    NARCIS (Netherlands)

    Diks, S. H.; van Deventer, S. J.; Peppelenbosch, M. P.

    2001-01-01

    Despite the importance of bacterial lipopolysaccharide (LPS) in infection and inflammation, many aspects of LPS action remain poorly understood. Especially, the mechanisms by which cells recognise and react to endotoxins or endotoxin-containing particles and how cellular responses are translated

  6. Estimation of the in vitro eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust by using reconstituted human corneal epithelium tissue cultures.

    Science.gov (United States)

    Cao, Yi; Bindslev, Dorthe A; Kjærgaard, Søren K

    2015-01-01

    Eye irritation is a common complaint in indoor environment, but the causes have still not been identified among the multiple exposures in house environments. To identify the potential environmental factors responsible for eye irritation and study the possible mechanisms, an in vitro model for eye irritation is suggested. In this study, reconstituted human corneal epithelium (HCE) tissue cultures were used to study the eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust. HCE tissue cultures were exposed to a range of concentrations of LPS for 6 h and dust for 24 h, respectively. After exposure, viability and secretion of interleukins (IL) IL-1β, IL-8, and tumor necrosis factor (TNFα) were examined. Histology was used to indicate the morphological changes after dust exposure. Both LPS and dust affected HCE viability. There was an increased level of IL-8 after LPS exposure, while the concentrations of IL-1β and TNFα remained unaffected. Dust exposure resulted in an elevation of both IL-1β and IL-8, but not TNFα. Histology study showed increased vacuolization and reduced thickness after 24 h exposure to 5 mg/mL dust. LPS and dust showed in vitro eye irritating and inflammatory potential, and cytokines/chemokines like IL-1β and IL-8 may be involved in the mechanisms of eye irritation. The HCE tissue culture may be used as an in vitro model to study environmental exposure induced eye irritation and inflammation.

  7. Lipopolysaccharide (LPS) stimulates fresh human monocytes to lyse actinomycin D-treated WEHI-164 target cells via increased secretion of a monokine similar to tumor necrosis factor

    International Nuclear Information System (INIS)

    Chen, A.R.; McKinnon, K.P.; Koren, H.S.

    1985-01-01

    The effects of lipopolysaccharide (LPS) on tumoricidal activity of human monocytes freshly isolated from peripheral blood were studied. Actinomycin D-treated WEHI-164 cells were used as targets because they are NK insensitive and are lysed rapidly by monocytes in 6-hr 51 Cr-release assays. Monocytes exhibited significant spontaneous activity without endotoxin. Monocytes either pretreated for 1 hr with LPS or assayed in the presence of LPS exhibited 100- to 1000-fold increased cytolytic activity. Cytolytic activity was heat labile and trypsin sensitive, and was recovered from Sepharose S-200 columns in a single peak with an apparent m.w. between 25,000 and 40,000. Actinomycin D or cycloheximide treatment of monocytes before the addition of LPS inhibited cytolytic monokine production. Cytolytic monokine activity was practically neutralized by specific rabbit antisera to human tumor necrosis factor (TNF). It was concluded that, although fresh human monocytes exhibit spontaneous tumoricidal activity, LPS is a potent activating agent. Its stimulatory effects depend on new transcription and translation and are mediated by enhanced secretion of a cytolytic monokine similar to TNF

  8. Relationship between plasma levels of zonulin, bacterial lipopolysaccharides, D-lactate and markers of inflammation in haemodialysis patients.

    Science.gov (United States)

    Ficek, Joanna; Wyskida, Katarzyna; Ficek, Rafał; Wajda, Jarosław; Klein, Dariusz; Witkowicz, Joanna; Rotkegel, Sylwia; Spiechowicz-Zatoń, Urszula; Kocemba-Dyczek, Joanna; Ciepał, Jarosław; Więcek, Andrzej; Olszanecka-Glinianowicz, Magdalena; Chudek, Jerzy

    2017-04-01

    Increased permeability of the intestinal wall and intestinal dysbiosis may contribute to chronic systemic inflammation, one of the causes of accelerated atherosclerosis and cardiovascular morbidity and mortality burden in patients with chronic kidney disease. The aim of this study was to evaluate the association between markers of intestinal permeability and inflammation in haemodialysis (HD) patients. Plasma concentration of zonulin, haptoglobin, TNFα, IL6, D-lactates and bacterial lipopolysaccharides (LPS) was assessed in blood samples obtained after overnight fast before midweek morning HD session in 150 stable, prevalent HD patients. Daily intake of energy and macronutrients was assessed on the basis of a food frequency questionnaire. Serum hsCRP level was increased in over 70% of patients. Plasma levels of zonulin [11.6 (10.9-12.3) vs 6.8 (5.8-7.8) ng/mL], IL6 [6.2 (1.0-10.3) vs 1.3 (1.0-2.0) pg/mL] and TNFα [5.9 (2.9-11.8) vs 1.6 (1.3-1.8) pg/mL], but not LPS and D-lactates were significantly higher in HD than in healthy controls. D-lactates and LPS levels were weakly associated with IL6 (R = 0.175; p = 0.03, and R = 0.241; p = 0.003). There was a borderline correlation between plasma zonulin and serum hsCRP (R = 0.159; p = 0.07), but not with IL6, LPS and D-lactates. In multiple regression, both serum CRP and plasma IL6 variability were explained by LPS (β = 0.143; p = 0.08 and β = 0.171; p = 0.04, respectively), only. The weak association between plasma D-lactate, LPS and IL6 levels indicates that intestinal flora overgrowth or increased intestinal permeability contributes very slightly to the chronic inflammation development in HD patients.

  9. Multiple lipopolysaccharide (LPS) injections alter interleukin 6 (IL-6), IL-7, IL-10 and IL-6 and IL-7 receptor mRNA in CNS and spleen.

    Science.gov (United States)

    Szot, Patricia; Franklin, Allyn; Figlewicz, Dianne P; Beuca, Timothy Petru; Bullock, Kristin; Hansen, Kim; Banks, William A; Raskind, Murray A; Peskind, Elaine R

    2017-07-04

    Neuroinflammation is proposed to be an important component in the development of several central nervous system (CNS) disorders including depression, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. However, exactly how neuroinflammation leads to, or contributes to, these central disorders is unclear. The objective of the study was to examine and compare the expression of mRNAs for interleukin-6 (IL-6), IL-7, IL-10 and the receptors for IL-6 (IL-6R) and IL-7 (IL-7R) using in situ hybridization in discrete brain regions and in the spleen after multiple injections of 3mg/kg lipopolysaccharide (LPS), a model of neuroinflammation. In the spleen, LPS significantly elevated IL-6 mRNA expression, then IL-10 mRNA, with no effect on IL-7 or IL-7R mRNA, while significantly decreasing IL-6R mRNA expression. In the CNS, LPS administration had the greatest effect on IL-6 and IL-6R mRNA. LPS increased IL-6 mRNA expression only in non-neuronal cells throughout the brain, but significantly elevated IL-6R mRNA in neuronal populations, where observed, except the cerebellum. LPS resulted in variable effects on IL-10 mRNA, and had no effect on IL-7 or IL-7R mRNA expression. These studies indicate that LPS-induced neuroinflammation has substantial but variable effects on the regional and cellular patterns of CNS IL-6, IL-7 and IL-10, and for IL-6R and IL-7R mRNA expression. It is apparent that administration of LPS can affect non-neuronal and neuronal cells in the brain. Further research is required to determine how CNS inflammatory changes associated with IL-6, IL-10 and IL-6R could in turn contribute to the development of CNS neurological disorders. Published by Elsevier Ltd.

  10. Effects of bacterial lipopolysaccharide and X-irradiation on the production of colony-stimulating factor and the maintenance of granulopoiesis in bone marrow culture

    International Nuclear Information System (INIS)

    Izumi, H.; Miyanomae, T.; Tsurusawa, M.; Fujita, J.; Mori, K.

    1984-01-01

    Effects of bacterial lipopolysaccharide (LPS) and X-irradiation on CSF production and granulopoiesis in long-term bone marrow cultures were studied. Levels of colony-stimulating factor (CSF) increased soon after the refeeding of the culture, but the activity was undetectable at day 7. Addition of LPS induced a significant increase in CSF levels in the culture, followed by an elevated granulopoiesis. The increase in CSF levels was suppressed when culture medium that had been harvested at refeeding on day 7 was added. Although irradiation did not increase CSF production, granulopoiesis was markedly stimulated shortly after irradiation. Thus granulopoiesis in long-term bone marrow culture may also be regulated by humoral factors such as CSF, and the culture system may represent the in vivo response to haemopoietic stimuli. (author)

  11. Licochalcone A Prevents the Loss of Dopaminergic Neurons by Inhibiting Microglial Activation in Lipopolysaccharide (LPS-Induced Parkinson’s Disease Models

    Directory of Open Access Journals (Sweden)

    Bingxu Huang

    2017-09-01

    Full Text Available The neuroprotective effects of Licochalcone A (Lico.A, a flavonoid isolated from the herb licorice, in Parkinson’s disease (PD have not been elucidated. The prominent pathological feature of PD is the loss of dopaminergic neurons. The crucial role of neuroinflammation induced by activated microglia in dopaminergic neurodegeneration has been validated. In this study, we explore the therapeutic effects of Lico.A in lipopolysaccharide (LPS-induced PD models in vivo and in vitro. We find that Lico.A significantly inhibits LPS-stimulated production of pro-inflammatory mediators and microglial activation by blocking the phosphorylation of extracellular signal-regulated kinase (ERK1/2 and nuclear factor κB (NF-κB p65 in BV-2 cells. In addition, through cultured primary mesencephalic neuron-glia cell experiments, we illustrate that Lico.A attenuates the decrease in [3H] dopamine (DA uptake and the loss of tyrosine hydroxylase-immunoreactive (TH-ir neurons in LPS-induced PD models in vitro. Furthermore, LPS intoxication in rats results in microglial activation, dopaminergic neurodegeneration and significant behavioral deficits in vivo. Lico.A treatment prevents microglial activation and reduction of dopaminergic neuron and ameliorates PD-like behavioral impairments. Thus, these results demonstrate for the first time that the neuroprotective effects of Lico.A are associated with microglia and anti-inflammatory effects in PD models.

  12. Polyphenolic extracts from cowpea (Vigna unguiculata) protect colonic myofibroblasts (CCD18Co cells) from lipopolysaccharide (LPS)-induced inflammation--modulation of microRNA 126.

    Science.gov (United States)

    Ojwang, Leonnard O; Banerjee, Nivedita; Noratto, Giuliana D; Angel-Morales, Gabriela; Hachibamba, Twambo; Awika, Joseph M; Mertens-Talcott, Susanne U

    2015-01-01

    Cowpea (Vigna unguiculata) is a drought tolerant crop with several agronomic advantages over other legumes. This study evaluated varieties from four major cowpea phenotypes (black, red, light brown and white) containing different phenolic profiles for their anti-inflammatory property on non-malignant colonic myofibroblasts (CCD18Co) cells challenged with an endotoxin (lipopolysaccharide, LPS). Intracellular reactive oxygen species (ROS) assay on the LPS-stimulated cells revealed antioxidative potential of black and red cowpea varieties. Real-time qRT-PCR analysis in LPS-stimulated cells revealed down-regulation of proinflammatory cytokines (IL-8, TNF-α, VCAM-1), transcription factor NF-κB and modulation of microRNA-126 (specific post-transcriptional regulator of VCAM-1) by cowpea polyphenolics. The ability of cowpea polyphenols to modulate miR-126 signaling and its target gene VCAM-1 were studied in LPS-stimulated endothelial cells transfected with a specific inhibitor of miR-126, and treated with 10 mg GAE/L black cowpea extract where the extract in part reversed the effect of the miR-126 inhibitor. This suggests that cowpea may exert their anti-inflammatory activities at least in part through induction of miR-126 that then down-regulate VCAM-1 mRNA and protein expressions. Overall, Cowpea therefore is promising as an anti-inflammatory dietary component.

  13. Mannose binding lectin enhances IL-1beta and IL-10 induction by non-lipopolysaccharide (LPS) components of Neisseria meningitidis.

    NARCIS (Netherlands)

    Sprong, T.; Jack, D.L.; Klein, N.J.; Turner, M.W.; Ley, P. van der; Steeghs, L.; Jacobs, L.; Meer, J.W.M. van der; Deuren, M. van

    2004-01-01

    Mannose binding lectin (MBL) is a key molecule in the lectin pathway of complement activation, and likely of importance in our innate defence against meningococcal infection. We evaluated the role of MBL in cytokine induction by LPS or non-LPS components of Neisseria meningitidis, using a

  14. The ability of lipopolysaccharide (LPS) of Pasteurella multocida B:2 to induce clinical and pathological lesions in the nervous system of buffalo calves following experimental inoculation.

    Science.gov (United States)

    Marza, Ali Dhiaa; Jesse Abdullah, Faez Firdaus; Ahmed, Ihsan Muneer; Teik Chung, Eric Lim; Ibrahim, Hayder Hamzah; Zamri-Saad, Mohd; Omar, Abdul Rahman; Abu Bakar, Md Zuki; Saharee, Abdul Aziz; Haron, Abdul Wahid; Alwan, Mohammed Jwaid; Mohd Lila, Mohd Azmi

    2017-03-01

    Lipopolysaccharide (LPS) of P. multocida B:2, a causative agent of haemorrhagic septicaemia (HS) in cattle and buffaloes, is considered as the main virulence factor and contribute in the pathogenesis of the disease. Recent studies provided evidences about the involvement of the nervous system in pathogenesis of HS. However, the role of P. multocida B:2 immunogens, especially the LPS is still uncovered. Therefore, this study was designed to investigate the role of P. multocida B:2 LPS to induce pathological changes in the nervous system. Nine eight-month-old, clinically healthy buffalo calves were used and distributed into three groups. Calves of Group 1 and 2 were inoculated orally and intravenously with 10 ml of LPS broth extract represent 1 × 10 12  cfu/ml of P. multocida B:2, respectively, while calves of Group 3 were inoculated orally with 10 ml of phosphate buffer saline as a control. Significant differences were found in the mean scores for clinical signs, post mortem and histopathological changes especially in Group 2, which mainly affect different anatomic regions of the nervous system, mainly the brain. On the other hand, lower scores have been recorded for clinical signs, gross and histopathological changes in Group 1. These results provide for the first time strong evidence about the ability of P. multocida B:2 LPS to cross the blood brain barrier and induce pathological changes in the nervous system of the affected buffalo calves. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Cordycepin Inhibits Lipopolysaccharide (LPS-Induced Tumor Necrosis Factor (TNF-α Production via Activating AMP-Activated Protein Kinase (AMPK Signaling

    Directory of Open Access Journals (Sweden)

    Jian-Li Zhang

    2014-07-01

    Full Text Available Tumor necrosis factor (TNF-α is elevated during the acute phase of Kawasaki disease (KD, which damages vascular endothelial cells to cause systemic vasculitis. In the current study, we investigated the potential role of cordycepin on TNFα expression in both lipopolysaccharide (LPS-stimulated macrophages and ex vivo cultured peripheral blood mononuclear cells (PBMCs of KD patients. We found that cordycepin significantly suppressed LPS-induced TNFα expression and production in mouse macrophages (RAW 264.7 cells and bone marrow-derived macrophages (BMDMs. Meanwhile, cordycepin alleviated TNFα production in KD patients’ PBMCs. PBMCs from healthy controls had a much lower level of basal TNF-α content than that of KD patients. LPS-induced TNF-α production in healthy controls’ PBMCs was also inhibited by cordycepin. For the mechanism study, we discovered that cordycepin activated AMP-activated protein kinase (AMPK signaling in both KD patients’ PBMCs and LPS-stimulated macrophages, which mediated cordycepin-induced inhibition against TNFα production. AMPK inhibition by its inhibitor (compound C or by siRNA depletion alleviated cordycepin’s effect on TNFα production. Further, we found that cordycepin inhibited reactive oxygen species (ROS production and nuclear factor kappa B (NF-κB activation in LPS-stimulate RAW 264.7 cells or healthy controls’ PBMCs. PBMCs of KD patients showed higher basal level of ROS and NF-κB activation, which was also inhibited by cordycepin co-treatment. In conclusion, our data showed that cordycepin inhibited TNFα production, which was associated with AMPK activation as well as ROS and NF-κB inhibition. The results of this study should have significant translational relevance in managing this devastating disease.

  16. The waaL gene is involved in lipopolysaccharide synthesis and plays a role on the bacterial pathogenesis of avian pathogenic Escherichia coli.

    Science.gov (United States)

    Han, Yue; Han, Xiangan; Wang, Shaohui; Meng, Qingmei; Zhang, Yuxi; Ding, Chan; Yu, Shengqing

    2014-08-27

    Avian pathogenic Escherichia coli (APEC) is a Gram-negative bacterium that causes avian colibacillosis, resulting in economically devastating to poultry industries worldwide. Lipopolysaccharide (LPS) has been identified as an important virulence factor of E. coli. The waaL gene encodes O-antigen ligase, which is responsible for attaching the O-antigen to lipid A-core oligosaccharide. In this study, a mutant strain ΔwaaL was constructed from APEC serotype 2 strain DE17. The mutant strain showed a decreased swimming motility and resistance to complement-mediated killing but a similar growth rate in the culture, compared with its parent strain. In addition, the mutant LPS demonstrated different patterns in SDS-PAGE followed by silver staining and western blotting. Besides, the mutant strain significantly decreased its adherence and invasion abilities to DF-1 cells, compared to its parent strain DE17. Deletion of the waaL gene in DE17 reduced the bacterial virulence by 42.2-fold in ducklings, based on measurement of the median lethal dose (LD50). Additional analysis indicated that deletion of the waaL gene increased the biofilm formation ability and reduced the resistance to environmental stress. These results suggest that the waaL gene functions on the APEC LPS synthesis and bacterial pathogenesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Bacterial lipoprotein-induced self-tolerance and cross-tolerance to LPS are associated with reduced IRAK-1 expression and MyD88-IRAK complex formation.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-02-03

    Tolerance to bacterial cell-wall components may represent an essential regulatory mechanism during bacterial infection. We have demonstrated previously that the inhibition of nuclear factor (NF)-kappaB and mitogen-activated protein kinase activation was present in bacterial lipoprotein (BLP) self-tolerance and its cross-tolerance to lipopolysaccharide (LPS). In this study, the effect of BLP-induced tolerance on the myeloid differentiation factor 88 (MyD88)-dependent upstream signaling pathway for NF-kappaB activation in vitro was examined further. When compared with nontolerant human monocytic THP-1 cells, BLP-tolerant cells had a significant reduction in tumor necrosis factor alpha (TNF-alpha) production in response to a high-dose BLP (86+\\/-12 vs. 6042+\\/-245 ng\\/ml, P < 0.01) or LPS (341+\\/-36 vs. 7882+\\/-318 ng\\/ml, P < 0.01) stimulation. The expression of Toll-like receptor 2 (TLR2) protein was down-regulated in BLP-tolerant cells, whereas no significant differences in TLR4, MyD88, interleukin-1 receptor-associated kinase 4 (IRAK-4), and TNF receptor-associated factor 6 expression were observed between nontolerant and BLP-tolerant cells, as confirmed by Western blot analysis. The IRAK-1 protein was reduced markedly in BLP-tolerant cells, although IRAK-1 mRNA expression remained unchanged as revealed by real-time reverse transcriptase-polymerase chain reaction analysis. Furthermore, decreased MyD88-IRAK immunocomplex formation, as demonstrated by immunoprecipitation, was observed in BLP-tolerant cells following a second BLP or LPS stimulation. BLP pretreatment also resulted in a marked inhibition in total and phosphorylated inhibitor of kappaB-alpha (IkappaB-alpha) expression, which was not up-regulated by subsequent BLP or LPS stimulation. These results demonstrate that in addition to the down-regulation of TLR2 expression, BLP tolerance is associated with a reduction in IRAK-1 expression, MyD88-IRAK association, and IkappaB-alpha phosphorylation. These

  18. Modulation of the main porcine enteric neuropeptides by a single low-dose of lipopolysaccharide (LPS)SalmonellaEnteritidis.

    Science.gov (United States)

    Mikołajczyk, Anita; Gonkowski, Sławomir; Złotkowska, Dagmara

    2017-01-01

    The present research was conducted to investigate the influence of a low, single dose of LPS, which does not result in any clinical symptoms of intoxication on the expression of selected neuropeptides within the intestines of the domestic pig. This experiment was conducted on immature female pigs of the Pitrain × Duroc breed (n = five per group). Seven days after the intravenous injection of 10 mL saline solution for control animals and 5 μg/kg b.w. (in 10 mL saline solution) LPS Salmonella Enteritidis for the experimental group, the excised segments of duodenum, jejunum, ileum, ileocecal valve, caecum, descending colon, transverse colon, ascending colon and rectum were prepared to extract the main enteric neuropeptides, including GAL, NPY, SOM, SP, VIP. The results of this research indicate that single low-dose LPS S. Enteritidis produced changes in the content of the selected neuropeptides of the porcine intestine. The most visible changes were observed in the transverse colon, where LPS induced the increase of GAL expression from 19.41 ± 7.121 to 92.92 ± 11.447 ng/g tissue. The exact functions of the substances studied and mechanisms of responses to LPS action depend on the sections of the intestines. The mechanisms of observed changes are not fully understood, but fluctuations in neuronal active substance levels may be connected with neurodegenerative and/or pro-inflammatory activity of LPS.

  19. Immunochemical characterization of rough Brucella lipopolysaccharides.

    OpenAIRE

    Moreno, E; Jones, L M; Berman, D T

    1984-01-01

    Lipopolysaccharides (LPS) were extracted from rough strains of Brucella abortus and Brucella melitensis and from strains of the naturally occurring rough species Brucella ovis and Brucella canis. Brucella rough lipopolysaccharides (R-LPS) were readily distinguished from Brucella smooth lipopolysaccharides (S-LPS) and enterobacterial R-LPS, by their chemical, physical, and serological characteristics. B. ovis R-LPS was differentiated from B. abortus, B. melitensis, and B. canis R-LPS by its re...

  20. Expression of Siglec-E Alters the Proteome of Lipopolysaccharide (LPS-Activated Macrophages but Does Not Affect LPS-Driven Cytokine Production or Toll-Like Receptor 4 Endocytosis

    Directory of Open Access Journals (Sweden)

    Manjula Nagala

    2018-01-01

    Full Text Available Siglec-E is a murine CD33-related siglec that functions as an inhibitory receptor and is expressed mainly on neutrophils and macrophage populations. Recent studies have suggested that siglec-E is an important negative regulator of lipopolysaccharide (LPS-toll-like receptor 4 (TLR4 signaling and one report (1 claimed that siglec-E is required for TLR4 endocytosis following uptake of Escherichia coli by macrophages and dendritic cells (DCs. Our attempts to reproduce these observations using cells from wild-type (WT and siglec-E-deficient mice were unsuccessful. We used a variety of assays to determine if siglec-E expressed by different macrophage populations can regulate TLR4 signaling in response to LPS, but found no consistent differences in cytokine secretion in vitro and in vivo, comparing three different strains of siglec-E-deficient mice with matched WT controls. No evidence was found that the siglec-E deficiency was compensated by expression of siglecs-F and -G, the other murine inhibitory CD33-related siglecs. Quantitative proteomics was used as an unbiased approach and provided additional evidence that siglec-E does not suppress inflammatory TLR4 signaling. Interestingly, proteomics revealed a siglec-E-dependent alteration in macrophage protein composition that could be relevant to functional responses in host defense. In support of this, siglec-E-deficient mice exhibited enhanced growth of Salmonella enterica serovar Typhimurium in the liver following intravenous infection, but macrophages lacking siglec-E did not show altered uptake or killing of bacteria in vitro. Using various cell types including bone marrow-derived DCs (BMDCs, splenic DCs, and macrophages from WT and siglec-E-deficient mice, we showed that siglec-E is not required for TLR4 endocytosis following E. coli uptake or LPS challenge. We failed to see expression of siglec-E by BMDC even after LPS-induced maturation, but confirmed previous studies that splenic DCs express

  1. Lipopolysaccharide (LPS) Promotes Apoptosis in Human Breast Epithelial × Breast Cancer Hybrids, but Not in Parental Cells.

    Science.gov (United States)

    Fried, Sabrina; Tosun, Songuel; Troost, Gabriele; Keil, Silvia; Zaenker, Kurt S; Dittmar, Thomas

    2016-01-01

    Toll-like receptors (TLRs) belong to the group of pathogen recognition receptors known to play a crucial role in the innate immune system. In cancer, TLR expression is still debated controversially due to contradictory results reporting that both induction of apoptosis as well as tumor progression could depend on TLR signaling, whereby recent data rather indicate a pro-tumorigenic effect. The biological phenomenon of cell fusion has been associated with cancer progression due to findings revealing that fusion-derived hybrid cells could exhibit properties like an increased metastatogenic capacity and an increased drug resistance. Thus, M13MDA435 hybrid cell lines, which derived from spontaneous fusion events between human M13SV1-EGFP-Neo breast epithelial cells and human MDA-MB-435-Hyg breast cancer cells, were investigated. Cultivation of cells in the presence of the TLR4 ligand LPS potently induced apoptosis in all hybrid clones, but not in parental cells, which was most likely attributed to differential kinetics of the TLR4 signal transduction cascade. Activation of this pathway concomitant with NF-κB nuclear translocation and TNF-α expression was solely observed in hybrid cells. However, induction of LPS mediated apoptosis was not TNF-α dependent since TNF-α neutralization was not correlated to a decreased amount of dead cells. In addition to TNF-α, LPS also caused IFN-β expression in hybrid clones 1 and 3. Interestingly, hybrid clones differ in the mode of LPS induced apoptosis. While neutralization of IFN-β was sufficient to impair the LPS induced apoptosis in M13MDA435-1 and -3 hybrids, the amount of apoptotic M13MDA435-2 and -4 hybrid cells remained unchanged in the presence of neutralizing IFN-β antibodies. In summary, the fusion of non-LPS susceptible parental human breast epithelial cells and human breast cancer cells gave rise to LPS susceptible hybrid cells, which is in view with the cell fusion hypothesis that hybrid cells could exhibit novel

  2. Inhibition of Nitric Oxide (NO Production in Lipopolysaccharide (LPS-Activated Murine Macrophage RAW 264.7 Cells by the Norsesterterpene Peroxide, Epimuqubilin A

    Directory of Open Access Journals (Sweden)

    Leng Chee Chang

    2010-03-01

    Full Text Available Seven norsesterterpene peroxides: epimuqubilin A (1, muqubilone B (2, unnamed cyclic peroxide ester (3, epimuqubilin B (4, sigmosceptrellin A methyl ester (5, sigmosceptrellin A (6, and sigmosceptrellin B methyl ester (7, isolated from the marine sponge Latrunculia sp., were examined with regard to their effects on nitric oxide (NO production in lipopolysaccharide (LPS-activated murine macrophage RAW 264.7 cells. The results indicated epimuqubilin A (1 possessed potent NO inhibitory activity against lipopolysaccharide (LPS-induced nitric oxide release with an IC50 value of 7.4 µM, a level three times greater than the positive control, L-NG-monomethyl arginine citrate, followed by 6 (sigmosceptrellin A, IC50 = 9.9 µM, whereas other compounds exhibited only modest activity (Table 1. These compounds did not show appreciable cytotoxicity at their IC50 values for NO–inhibitory activity. The structure–activity upon NO inhibition could be summarized as follows: (1 a monocyclic carbon skeleton framework was essential for activity,(2 free acids gave higher activity, (3 the orientation of H3-22 with an equatorial position increased activity, and (4 a bicyclic structure reduced activity. This is the first report of a norsesterterpene peroxide with NO–inhibitory activity. In addition, compounds 1–7 were also evaluated for their inhibitory activities in the yeast glycogen synthase kinase-3βassay. In summary, several norsesterterpene peroxides showed novel biological activities of inhibition in NO production, suggesting that these might provide leads for anti-inflammatory or cancer chemopreventive agents.

  3. A low-level diode laser therapy reduces the lipopolysaccharide (LPS)-induced periodontal ligament cell inflammation

    International Nuclear Information System (INIS)

    Huang, T H; Chen, C C; Liu, S L; Lu, Y C; Kao, C T

    2014-01-01

    The purpose of this study was to investigate the cytologic effects of inflammatory periodontal ligament cells in vitro after low-level laser therapy. Human periodontal ligament cells were cultured, exposed to lipopolysaccharide and subjected to low-level laser treatment of 5 J cm −2 or 10 J cm −2 using a 920 nm diode laser. A periodontal ligament cell attachment was observed under a microscope, and the cell viability was quantified by a mitochondrial colorimetric assay. Lipopolysaccharide-treated periodontal ligament cells were irradiated with the low-level laser, and the expression levels of several inflammatory markers, iNOS, TNF-α and IL-1, and pErk kinase, were analyzed by reverse transcription polymerase chain reaction and western blot. The data were collected and analyzed by one-way analysis of variance; p < 0.05 indicated a statistically significant difference. The low-level laser treatment of periodontal ligament cells increased their ability to attach and survive. After irradiation, the expression levels of iNOS, TNF-α and IL-1 in lipopolysaccharide-exposed periodontal ligament cells decreased over time (p < 0.05). In periodontal ligament cells, low-level diode laser treatment increased the cells’ proliferative ability and decreased the expression of the examined inflammatory mediators. (letters)

  4. Cyanobacterial lipopolysaccharides and human health – a review

    Directory of Open Access Journals (Sweden)

    Schluter Philip J

    2006-03-01

    Full Text Available Abstract Cyanobacterial lipopolysaccharide/s (LPS are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation.

  5. Small intestinal bacterial overgrowth in nonalcoholic steatohepatitis: association with toll-like receptor 4 expression and plasma levels of interleukin 8.

    LENUS (Irish Health Repository)

    Shanab, Ahmed Abu

    2011-05-01

    Experimental and clinical studies suggest an association between small intestinal bacterial overgrowth (SIBO) and nonalcoholic steatohepatitis (NASH). Liver injury and fibrosis could be related to exposure to bacterial products of intestinal origin and, most notably, endotoxin, including lipopolysaccharide (LPS).

  6. High-fat diet induces periodontitis in mice through lipopolysaccharides (LPS receptor signaling: protective action of estrogens.

    Directory of Open Access Journals (Sweden)

    Vincent Blasco-Baque

    Full Text Available BACKGROUND: A fat-enriched diet favors the development of gram negative bacteria in the intestine which is linked to the occurrence of type 2 diabetes (T2D. Interestingly, some pathogenic gram negative bacteria are commonly associated with the development of periodontitis which, like T2D, is characterized by a chronic low-grade inflammation. Moreover, estrogens have been shown to regulate glucose homeostasis via an LPS receptor dependent immune-modulation. In this study, we evaluated whether diet-induced metabolic disease would favor the development of periodontitis in mice. In addition, the regulatory role of estrogens in this process was assessed. METHODS: Four-week-old C57BL6/J WT and CD14 (part of the TLR-4 machinery for LPS-recognition knock-out female mice were ovariectomised and subcutaneously implanted with pellets releasing either placebo or 17β-estradiol (E2. Mice were then fed with either a normal chow or a high-fat diet for four weeks. The development of diabetes was monitored by an intraperitoneal glucose-tolerance test and plasma insulin concentration while periodontitis was assessed by identification of pathogens, quantification of periodontal soft tissue inflammation and alveolar bone loss. RESULTS: The fat-enriched diet increased the prevalence of periodontal pathogenic microbiota like Fusobacterium nucleatum and Prevotella intermedia, gingival inflammation and alveolar bone loss. E2 treatment prevented this effect and CD14 knock-out mice resisted high-fat diet-induced periodontal defects. CONCLUSIONS/SIGNIFICANCE: Our data show that mice fed with a diabetogenic diet developed defects and microflora of tooth supporting-tissues typically associated with periodontitis. Moreover, our results suggest a causal link between the activation of the LPS pathway on innate immunity by periodontal microbiota and HFD-induced periodontitis, a pathophysiological mechanism that could be targeted by estrogens.

  7. Structure-Activity Relationships of Lipopolysaccharide Sequestration in Guanylhydrazone-bearing Lipopolyamines

    OpenAIRE

    Wu, Wenyan; Sil, Diptesh; Szostak, Michal L.; Malladi, Subbalakshmi S.; Warshakoon, Hemamali J.; Kimbrell, Matthew R.; Cromer, Jens R.; David, Sunil A.

    2008-01-01

    The toxicity of Gram-negative bacterial endotoxin (lipopolysaccharide, LPS) resides in its structurally highly conserved glycolipid component called lipid A. Our major goal has been to develop small-molecules that would sequester LPS by binding to the lipid A moiety, so that it could be useful for the prophylaxis or adjunctive therapy of Gram-negative sepsis. We had previously identified in rapid-throughput screens several guanylhydrazones as potent LPS binders. We were desirous of examining ...

  8. Changes of caspase activities involved in apoptosis of a macrophage-like cell line J774.1/JA-4 treated with lipopolysaccharide (LPS) and cycloheximide.

    Science.gov (United States)

    Karahashi, H; Amano, F

    2000-02-01

    The addition of lipopolysaccharide (LPS) together with cycloheximide (CHX) induced apoptosis in a subline of a J774.1 macrophage-like cell line, JA-4, as judged by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL)-staining and poly(adenosine 5'-diphosphate (ADP)-ribose) polymerase (PARP)-cleavage. Caspase activities were examined in these macrophages in vitro using fluorogenic substrates such as acetyl-DEVD-aminomethyl coumarine (Ac-DEVD-AMC, caspase-3-like), acetyl-YVAD-aminomethyl coumarine (Ac-YVAD-AMC, caspase-1-like), acetyl-VEID-aminomethyl coumarine (Ac-VEID-AMC, caspase-6-like), and carbobenzoxy-IETD-aminofluoro coumarine (Z-IETD-AFC; caspase-8-like). Kinetic studies revealed these caspase activities with different Km and Vmax values in extracts of apoptotic macrophages. In the course of apoptosis, caspase-3-like activity increased first at 75 min, simultaneously with the appearance of TUNEL staining and prior to PARP cleavage, and then caspase-6 and 8-like activities increased at 90 and 105 min, respectively. However, caspase-1-like activity did not change throughout the experiment. Furthermore, removal of LPS and CHX by extensive washing of the cells for 60 min completely abolished the apoptosis and the subsequent release of lactate dehydrogenase (LDH) during additional incubation until 4 h after LPS addition. However, washing of the cells after 75 min or later resulted in the progress of apoptosis and LDH release, which was coordinated with the elevation of caspase-3-like activity at 60 min and that of caspase-6 or 8-like activity at 90 min, but not with that of caspase-1-like activity. These results suggest that caspase-3-like activity represents the most apical caspase among these caspases in terms of the intiation of apoptosis in macrophages treated with LPS and CHX. In the present study, we also provide evidence on the relatively low specificities of a series of caspase inhibitors other

  9. Structural elucidation of a novel core oligosaccharide backbone of the lipopolysaccharide from the new bacterial species Agrobacterium larrymoorei.

    Science.gov (United States)

    Molinaro, Antonio; De Castro, Cristina; Lanzetta, Rosa; Parrilli, Michelangelo; Raio, Aida; Zoina, Astolfo

    2003-11-14

    Agrobacterium larrymoorei is a Gram-negative phytopathogenic bacterium, which produces tumours on Ficus benjamina plants and differs from other Agrobacteria both genetically and biochemically. The lipopolysaccharide (LPS) plays an important role in the pathogenesis of Agrobacteria. The present paper is the first report on the molecular primary structure of the core region of an Agrobacterium LPS. The following structure of the core and lipid A carbohydrate backbone of an R-form LPS of A. larrymoorei was determined by chemical degradations and 1D and 2D NMR spectroscopy: [carbohydrate structure: see text] All sugars are alpha-D-pyranoses if not stated otherwise, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, Qui3NAcyl is 3,6-dideoxy-3-(3-hydroxy-2,3-dimethyl-5-oxoprolylamino)glucose, GlcAN and GalAN are amides of GlcA and GalA.

  10. Sickness behaviour after lipopolysaccharide treatment in ghrelin deficient mice

    OpenAIRE

    Szentirmai, Éva; Krueger, James M.

    2013-01-01

    Ghrelin is an orexigenic hormone produced mainly by the gastrointestinal system and the brain. Much evidence also indicates a role for ghrelin in sleep and thermoregulation. Further, ghrelin was recently implicated in immune system modulation. Administration of bacterial lipopolysaccharide (LPS) induces fever, anorexia, and increased non-rapid-eye movement sleep (NREMS) and these actions are mediated primarily by proinflammatory cytokines. Ghrelin reduces LPS-induced fever, ...

  11. Functional and Evolutionary Characterization of a UDP-Xylose Synthase Gene from the Plant Pathogen Xylella fastidiosa, Involved in the Synthesis of Bacterial Lipopolysaccharide.

    Science.gov (United States)

    Alencar, Valquíria Campos; Jabes, Daniela Leite; Menegidio, Fabiano Bezerra; Sassaki, Guilherme Lanzi; de Souza, Lucas Rodrigo; Puzer, Luciano; Meneghetti, Maria Cecília Zorél; Lima, Marcelo Andrade; Tersariol, Ivarne Luis Dos Santos; de Oliveira, Regina Costa; Nunes, Luiz R

    2017-02-07

    Xylella fastidiosa is a plant-infecting bacillus, responsible for many important crop diseases, such as Pierce's disease of vineyards, citrus variegated chlorosis, and coffee leaf scorch (CLS), among others. Recent genomic comparisons involving two CLS-related strains, belonging to X. fastidiosa subsp. pauca, revealed that one of them carries a frameshift mutation that inactivates a gene encoding an oxidoreductase of the short-chain dehydrogenase/reductase (SDR) superfamily, which may play important roles in determining structural variations in bacterial glycans and glycoconjugates. However, the exact nature of this SDR has been a matter of controversy, as different annotations of X. fastidiosa genomes have implicated it in distinct reactions. To confirm the nature of this mutated SDR, a comparative analysis was initially performed, suggesting that it belongs to a subgroup of SDR decarboxylases, representing a UDP-xylose synthase (Uxs). Functional assays, using a recombinant derivative of this enzyme, confirmed its nature as XfUxs, and carbohydrate composition analyses, performed with lipopolysaccharide (LPS) molecules obtained from different strains, indicate that inactivation of the X. fastidiosa uxs gene affects the LPS structure among CLS-related X. fastidiosa strains. Finally, a comparative sequence analysis suggests that this mutation is likely to result in a morphological and evolutionary hallmark that differentiates two subgroups of CLS-related strains, which may influence interactions between these bacteria and their plant and/or insect hosts.

  12. Improved immunogenicity of tetanus toxoid by Brucella abortus S19 LPS adjuvant.

    Science.gov (United States)

    Mohammadi, Mohsen; Kianmehr, Zahra; Kaboudanian Ardestani, Sussan; Gharegozlou, Behnaz

    2014-09-01

    Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella abortus LPS is less toxic and has no pyrogenic properties compared to LPS from other gram negative bacteria. To evaluate the adjuvant effect of B. abortus (vaccine strain, S19) LPS for tetanus toxoid antigen (TT) and to investigate the protective effect of different tetanus vaccine preparations. LPS was extracted and purified from B. abortus S19 and KDO, glycan, phosphate content, and protein contamination were measured. Adipic acid dihydrazide (ADH) was used as a linker for conjugation of TT to LPS. Different amounts of B. abortus LPS, TT, TT conjugated with LPS, and TT mixed with LPS or complete Freund's adjuvant (CFA) were injected into mice and antibody production against TT was measured. The protective effect of induced antibodies was determined by LD50. Immunization of mice with TT+LPS produced the highest anti-TT antibody titer in comparison to the group immunized with TT without any adjuvant or the groups immunized with TT-LPS or TT+CFA. Tetanus toxid-S19 LPS also produced a 100% protective effect against TT in immunized mice. These data indicate that B. abortus LPS enhances the immune responses to TT and suggest the possible use of B. abortus LPS as an adjuvant in vaccine preparations.

  13. Sialylation of Porphyromonas gingivalis LPS and its effect on bacterial-host interactions.

    Science.gov (United States)

    Zaric, Svetislav S; Lappin, Mark J; Fulton, Catherine R; Lundy, Fionnuala T; Coulter, Wilson A; Irwin, Christopher R

    2017-04-01

    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.

  14. Bioassay-guided fractionation of ethyl acetate extract from Armillaria mellea attenuates inflammatory response in lipopolysaccharide (LPS) stimulated BV-2 microglia.

    Science.gov (United States)

    Geng, Yan; Zhu, Shuiling; Cheng, Peng; Lu, Zhen-Ming; Xu, Hong-Yu; Shi, Jin-Song; Xu, Zheng-Hong

    2017-03-15

    Armillaria mellea (A. mellea) is a traditional Chinese medicinal and edible mushroom, which is proved to possess a lot of biological activities, including anti-oxidation, immunopotentiation, anti-vertigo and anti-aging activities. However, little information is available in regard to its neuroprotection activity in inflammation-mediated neurodegenerative diseases. We have found that A. mellea has an anti-inflammatory activity in LPS-induced RAW264.7 cells in our previous study. The objective of this study is to investigate the anti-neuroinflammatory mechanism of a bioassay-guided fractionation (Fr.2) and its active components/compounds. Compounds were isolated by preparative high performance liquid chromatography (pre-HPLC) and their structures were established by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic analyses. The anti-neuroinflammatory effect of Fr.2 and each compounds were investigated in lipopolysaccharide (LPS)-stimulated murine microglia cell lineBV-2. We demonstrated that Fr.2 significantly decreased the production of inflammation mediator nitric oxide (NO) and inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1beta (IL-1β) in a dose-dependent manner (10, 30, 100µg/ml). In addition, Fr.2 markedly down-regulated the phosphorylation levels of nuclear factor kappa B p65 (NF-κB p65), inhibitory κB-α (IκB-α) and c-Jun N-terminal kinases (JNKs) pathways. Sevens compounds were isolated from Fr.2, among them, three compounds, 5-hydroxymethylfurfural (CP1), vanillic acid (CP4) and syringate (CP5) were reported for the first time in A. mellea. NO and inflammatory cytokines (TNF-α, IL-6, IL-1β) secretion indicated that daidzein (CP6) and genistein (CP7) showed a more outstanding anti-inflammation potential at non-toxic concentrations (10, 30, 100µM) than the other five compounds. In conclusion, Fr.2 may have therapeutic potential for neurodegenerative diseases by inhibiting

  15. Activation of camalexin biosynthesis in Arabidopsis thaliana in response to perception of bacterial lipopolysaccharides: a gene-to-metabolite study.

    Science.gov (United States)

    Beets, Caryn Ann; Huang, Ju-Chi; Madala, Ntakadzeni Edwin; Dubery, Ian

    2012-07-01

    Lipopolysaccharides (LPS), as lipoglycan microbe-associated molecular pattern molecules, trigger activation of signal transduction pathways involved in defence that generate an enhanced defensive capacity in plants. The transcriptional regulation of the genes for tryptophan synthase B, TSB1, and the cytochrome P450 monooxygenases CYP79B2 and CYP71B15, involved in the camalexin biosynthetic pathway, were investigated in response to LPS treatment. GUS-reporter assays for CYP71B15 and CYP79B2 gene promoter activation were performed on transgenic plants and showed positive histochemical staining in response to LPS treatment, indicating activation of the promoters. Quantitative PCR revealed that transcripts of TSB1, CYP79B2 and CYP71B15 exhibited differential, transient up-regulation. TSB1 transcript levels were up-regulated between 6 and 9 h after LPS-induction, while CYP71B15 and CYP79B2 both exhibited maxima at 12 h. To obtain information on the gene-to-metabolite network, the effect of the transcriptome changes on the metabolome was correlated to camalexin production. Increases in camalexin concentration were quantified by ultra pressure liquid chromatography-mass spectrometry and both absorbance spectra and elemental composition confirmed its identity. The concentrations increased from 0.03 to 3.7 μg g(-1) fresh weight over a 24-h time period, thus indicating that the up-regulation of the biosynthetic pathway in response to LPS was accompanied by a time-dependent increase in camalexin concentration. Metabolomic analysis through principal component analysis-derived scores plots revealed clusters of sample replicates for 0, 6, 12, 18 and 24 h while loadings plots for LPS data identified camalexin as a biomarker that clearly demonstrated the variability between samples.

  16. Microfiltration, Nano-filtration and Reverse Osmosis for the Removal of Toxins (LPS Endotoxins) from Wastewater

    OpenAIRE

    Mokhtar, Guizani; Naoyuki, Funamizu

    2012-01-01

    Lipopolysaccharide (LPS) endotoxin, a bacterial byproduct abundantly present in wastewater, is more and more representing a major concern in wastewater treatment sector for the potential health risk it represents. It is, therefore, more urgent than before to protect consumers from contaminating their fresh potable water reserves with LPS endotoxin through aquifer replenishment using reclaimed wastewater or by supplying reclaimed wastewater as potable water. Membrane treatment is an alternativ...

  17. Blood-borne LPS is rapidly eliminated by liver sinusoidal endothelial cells via HDL

    Science.gov (United States)

    Yao, Zhili; Mates, Jessica M.; Cheplowitz, Alana M.; Hammer, Lindsay P.; Maiseyeu, Andrei; Phillips, Gary S.; Wewers, Mark D.; Rajaram, Murugesan V.S.; Robinson, John M.; Anderson, Clark L.; Ganesan, Latha P.

    2016-01-01

    During Gram-negative bacterial infections, excessive lipopolysaccharide (LPS) induces inflammation and sepsis via action on immune cells. However, the bulk of LPS can be cleared from circulation by the liver. Liver clearance is thought to be a slow process mediated exclusively by phagocytic resident macrophages, Kupffer cells (KC). However, we discovered that LPS disappears rapidly from the circulation, with a half-life of 2–4 minutes in mice and liver eliminates about three quarters of LPS from blood circulation. Using microscopic techniques, we found that ~75% of fluor-tagged LPS in liver became associated with liver sinusoidal endothelial cells (LSEC) and only ~25% with KC. Notably, the ratio of LSEC-KC associated LPS remained unchanged 45 min after infusion, indicating that LSEC independently processes the LPS. Most interestingly, results of kinetic analysis of LPS bioactivity, using modified limulus amebocyte lysate assay, suggest that recombinant factor-C, an LPS binding protein, competitively inhibits HDL-mediated LPS association with LSEC early in the process. Supporting the previous notion 3 min post-infusion, 75% of infused fluorescently-tagged LPS-HDL complex associates with LSEC, suggesting that HDL facilitates LPS clearance. These results lead us to propose a new paradigm of LSEC and HDL in clearing LPS with a potential to avoid inflammation during sepsis. PMID:27534554

  18. LPS differentially affects vasoconstrictor responses: a potential role for RGS16?

    NARCIS (Netherlands)

    Hendriks-Balk, M. C.; Tjon-Atsoi, M.; Hajji, N.; Alewijnse, A. E.; Peters, S. L. M.

    2009-01-01

    The profound hypotension in septic shock patients is difficult to treat as it is accompanied by depressed constrictor responses to alpha1-adrenoceptor agonists. Bacterial lipopolysaccharide (LPS) is the main trigger for most of the cardiovascular alterations occurring in septic shock. In this study

  19. Modulating the bacterial surface with small RNAs: a new twist on PhoP/Q-mediated lipopolysaccharide modification

    DEFF Research Database (Denmark)

    Overgaard, Martin; Kallipolitis, Birgitte; Valentin-Hansen, Poul

    2009-01-01

    Summary In recent years, small non-coding RNAs have emerged as important regulatory components in bacterial stress responses and in bacterial virulence. Many of these are conserved in related species and act on target mRNAs by sequence complementarity. They are tightly controlled...... of bacterial surface properties by regulating lipopolysaccharide modification. The small RNA is expressed as part of the PhoP/PhoQ two-component system that plays a major role in virulence of pathogenic species. This work expands the list of global regulators known to control small RNA expression...

  20. Lipopolysaccharide biogenesis and transport at the outer membrane of Gram-negative bacteria.

    Science.gov (United States)

    Sperandeo, Paola; Martorana, Alessandra M; Polissi, Alessandra

    2017-11-01

    The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer containing a unique glycolipid, lipopolysaccharide (LPS) in its outer leaflet. LPS molecules confer to the OM peculiar permeability barrier properties enabling Gram-negative bacteria to exclude many toxic compounds, including clinically useful antibiotics, and to survive harsh environments. Transport of LPS poses several problems to the cells due to the amphipatic nature of this molecule. In this review we summarize the current knowledge on the LPS transport machinery, discuss the challenges associated with this process and present the solutions that bacterial cells have evolved to address the problem of LPS transport and assembly at the cell surface. Finally, we discuss how knowledge on LPS biogenesis can be translated for the development of novel antimicrobial therapies. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016. Published by Elsevier B.V.

  1. Function of an anti-lipopolysaccharide factor (ALF) isoform isolated from the hemocytes of the giant freshwater prawn Macrobrachium rosenbergii in protecting against bacterial infection.

    Science.gov (United States)

    Liu, Chia-Chen; Chung, Chien-Pang; Lin, Chang-Yi; Sung, Hung-Hung

    2014-02-01

    In this study, a 780-bp full-length cDNA encoding Macrobrachium rosenbergii anti-lipopolysaccharide factor (MrALF) from hemocytes was cloned and identified. The ALF isoform exhibited immune activities, and its concentration in hemolymph was determined. An in vivo expression study showed that the ALF mRNA level of hemocytes could be induced by lipopolysaccharides (LPSs) in an exposure time-dependent manner. Purified recombinant MrALF (rMrALF) expressed in the yeast Pichia pastoris SMD1168 eukaryotic protein expression system demonstrated antibacterial activity against the Gram-negative prawn pathogen Aeromonas hydrophila (minimum inhibitory concentration (MIC)=0.806μM, minimum bactericidal concentration (MBC)=1.606μM) but not the Gram-positive pathogen Lactococcus garvieae exposed to 25.696μM of rALF. However, rMrALF can bind to Gram-negative and -positive bacteria. An in vivo expression study demonstrated that the ALF concentrations in prawn hemocytes and plasma were 0.176μM and 0.168μM, respectively; following LPS treatment for 6h, the corresponding concentrations were 0.133μM in hemocytes and 0.272μM in plasma. Furthermore, the percentage of hemocytes phagocytosing bacteria cells was higher in hemoyctes previously treated with MrALF than those treated with sterile medium. These results suggest that in the innate immune response of M. rosenbergii, the MrALF from hemocytes may play an opsonin during a bacterial invasion. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Self-assembly of lipopolysaccharide layers on allantoin crystals.

    Science.gov (United States)

    Vagenende, Vincent; Ching, Tim-Jang; Chua, Rui-Jing; Jiang, Qiu Zhen; Gagnon, Pete

    2014-08-01

    Self-assembly of lipopolysaccharides (LPS) on solid surfaces is important for the study of bacterial membranes, but has not been possible due to technical difficulties and the lack of suitable solid supports. Recently we found that crystals of the natural compound allantoin selectively bind pure LPS with sub-nanomolar affinity. The physicochemical origins of this selectivity and the adsorption mode of LPS on allantoin crystals remain, however, unknown. In this study we present evidence that LPS adsorption on allantoin crystals is initiated through hydrogen-bond attachment of hydrophilic LPS regions. Hydrophobic interactions between alkyl chains of adjacently adsorbed LPS molecules subsequently promote self-assembly of LPS layers. The essential role of hydrogen-bond interactions is corroborated by our finding that allantoin crystals bind to practically any hydrophilic surface chemistry. Binding contributions of hydrophobic interactions between LPS alkyl chains are evidenced by the endothermic nature of the adsorption process and explain why the binding affinity for LPS is several orders of magnitude higher than for proteins (lysozyme, BSA and IgG) and polysaccharides. Self-assembly of LPS layers via hydrogen-bond attachment on allantoin crystals emerges as a novel binding mechanism and could be considered as a practical method for preparing biomimetic membranes on a solid support. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Crystal structure of an endotoxin-neutralizing protein from the horseshoe crab, Limulus anti-LPS factor, at 1.5 A resolution.

    Science.gov (United States)

    Hoess, A; Watson, S; Siber, G R; Liddington, R

    1993-09-01

    Lipopolysaccharide (LPS), or endotoxin, is the major mediator of septic shock, a serious complication of Gram-negative bacterial infections in humans. Molecules that bind LPS and neutralize its biological effects or enhance its clearance could have important clinical applications. Limulus anti-LPS factor (LALF) binds LPS tightly, and, in animal models, reduces mortality when administered before or after LPS challenge or bacterial infection. Here we present the high resolution structure of a recombinant LALF. It has a single domain consisting of three alpha-helices packed against a four-stranded beta-sheet. The wedge-shaped molecule has a striking charge distribution and amphipathicity that suggest how it can insert into membranes. The binding site for LPS probably involves an extended amphipathic loop, and we propose that two mammalian LPS-binding proteins will have a similar loop. The amphipathic loop structure may be used in the design of molecules with therapeutic properties against septic shock.

  4. Evaluation of 5-HT7 Receptor Trafficking on In Vivo and In Vitro Model of Lipopolysaccharide (LPS)-Induced Inflammatory Cell Injury in Rats and LPS-Treated A549 Cells.

    Science.gov (United States)

    Ayaz, Gulsen; Halici, Zekai; Albayrak, Abdulmecit; Karakus, Emre; Cadirci, Elif

    2017-02-01

    This study aimed to investigate the effects of the 5-HT7 receptor agonist (LP44) and antagonist (SB269970) on LPS-induced in vivo tissue damage and cell culture by molecular methods. This study was conducted in two steps. For in vivo studies, 24 female rats were divided into four groups. Group I: healthy; II (2nd h): LPS 5 mg/kg administered intraperitoneally (i.p.); III (4th h): LPS 5 mg/kg administered i.p.; IV (8th h): LPS 5 mg/kg administered i.p. For in vitro studies, we used the A549 cell line. Groups: I control (healthy) (2-4 h); II LPS: 1 µg/ml E. Coli O55:B5 strain (2-4 h); III agonist (LP44) 10 -9 M (2-4 h); IV antagonist (SB269970) 10 -9 M (2-4 h); V LPS+agonist 10 -9 M (LP44 1 µg/ml) (2-4 h); VI LPS+antagonist 10 -9 M (2-4 h). In molecular analyses, we determined increased TNF-α, IL-1β, NF-κB, and 5-HT7 mRNA expressions in rat lung tissues and increased TNF-α, iNOS, and 5-HT7 mRNA expressions in the A549 cell line. In in vitro parameters, LP44 agonist administration-related decrease was observed. Our study showed that lung 5-HT7 receptor expression is increased in LPS-induced endotoxemia. All this data suggest that 5-HT7 receptor overexpression is an important protective mechanism during LPS-induced sepsis-related cell damage.

  5. Artesunate Reduces Serum Lipopolysaccharide in Cecal Ligation/Puncture Mice via Enhanced LPS Internalization by Macrophages through Increased mRNA Expression of Scavenger Receptors

    Directory of Open Access Journals (Sweden)

    Bin Li

    2014-01-01

    Full Text Available Innate immunity is the first line of defense in human beings against pathogen infection; monocytes/macrophages are the primary cells of the innate immune system. Recently, macrophages/monocytes have been discovered to participate in LPS clearance, and the clearance efficiency determines the magnitude of the inflammatory response and subsequent organ injury. Previously, we reported that artesunate (AS protected sepsis mice against heat-killed E. coli challenge. Herein, we further confirmed that AS protected cecal ligation/puncture (CLP sepsis mice. Its protection on sepsis mice was related to not only reduction of pro-inflammatory cytokines and serum LPS levels but also improvement of liver function. Based on the fact that AS did not directly bind and neutralize LPS, we hypothesized that the reduction of serum LPS level might be related to enhancement of LPS internalization and subsequent detoxification. Our results showed that AS increased FITC-LPS internalization by peritoneal macrophage and liver Kupffer cell, but enhancement of LPS internalization by AS was not related to the clathrin-dependent pathway. However, AS induced mRNA expression of important scavenger receptors (SRs; SR-A and MARCO mRNA expression was upregulated, suggesting that AS enhancement of LPS internalization and inhibition of pro-inflammatory cytokines was related to changes in mRNA expression of SRs.

  6. Transactivation of EGFR by LPS induces COX-2 expression in enterocytes.

    Directory of Open Access Journals (Sweden)

    Steven J McElroy

    Full Text Available Necrotizing enterocolitis (NEC is the leading cause of gastrointestinal morbidity and mortality in preterm infants. NEC is characterized by an exaggerated inflammatory response to bacterial flora leading to bowel necrosis. Bacterial lipopolysaccharide (LPS mediates inflammation through TLR4 activation and is a key molecule in the pathogenesis of NEC. However, LPS also induces cyclooxygenase-2 (COX-2, which promotes intestinal barrier restitution through stimulation of intestinal cell survival, proliferation, and migration. Epidermal growth factor receptor (EGFR activation prevents experimental NEC and may play a critical role in LPS-stimulated COX-2 production. We hypothesized that EGFR is required for LPS induction of COX-2 expression. Our data show that inhibiting EGFR kinase activity blocks LPS-induced COX-2 expression in small intestinal epithelial cells. LPS induction of COX-2 requires Src-family kinase signaling while LPS transactivation of EGFR requires matrix metalloprotease (MMP activity. EGFR tyrosine kinase inhibitors block LPS stimulation of mitogen-activated protein kinase ERK, suggesting an important role of the MAPK/ERK pathway in EGFR-mediated COX-2 expression. LPS stimulates proliferation of IEC-6 cells, but this stimulation is inhibited with either the EGFR kinase inhibitor AG1478, or the selective COX-2 inhibitor Celecoxib. Taken together, these data show that EGFR plays an important role in LPS-induction of COX-2 expression in enterocytes, which may be one mechanism for EGF in inhibition of NEC.

  7. Deciphering the dual effect of lipopolysaccharides from plant pathogenic Pectobacterium.

    Science.gov (United States)

    Mohamed, Kettani-Halabi; Daniel, Tran; Aurélien, Dauphin; El-Maarouf-Bouteau, Hayat; Rafik, Errakhi; Arbelet-Bonnin, Delphine; Biligui, Bernadette; Florence, Val; Mustapha, Ennaji Moulay; François, Bouteau

    2015-01-01

    Lipopolysaccharides (LPS) are a component of the outer cell surface of almost all Gram-negative bacteria and play an essential role for bacterial growth and survival. Lipopolysaccharides represent typical microbe-associated molecular pattern (MAMP) molecules and have been reported to induce defense-related responses, including the expression of defense genes and the suppression of the hypersensitive response in plants. However, depending on their origin and the challenged plant, LPS were shown to have complex and different roles. In this study we showed that LPS from plant pathogens Pectobacterium atrosepticum and Pectobacterium carotovorum subsp. carotovorum induce common and different responses in A. thaliana cells when compared to those induced by LPS from non-phytopathogens Escherichia coli and Pseudomonas aeruginosa. Among common responses to both types of LPS are the transcription of defense genes and their ability to limit of cell death induced by Pectobacterium carotovorum subsp carotovorum. However, the differential kinetics and amplitude in reactive oxygen species (ROS) generation seemed to regulate defense gene transcription and be determinant to induce programmed cell death in response to LPS from the plant pathogenic Pectobacterium. These data suggest that different signaling pathways could be activated by LPS in A. thaliana cells.

  8. G(ANH)MTETRA, A NATURAL BACTERIAL-CELL WALL BREAKDOWN PRODUCT, INDUCES INTERLEUKIN-1-BETA AND INTERLEUKIN-6 EXPRESSION IN HUMAN MONOCYTES - A STUDY OF THE MOLECULAR MECHANISMS INVOLVED IN INFLAMMATORY CYTOKINE EXPRESSION

    NARCIS (Netherlands)

    DOKTER, WHA; DIJKSTRA, AJ; KOOPMANS, SB; STULP, BK; KECK, W; HALIE, MR; VELLENGA, E

    1994-01-01

    It is believed that induction of cytokine expression by bacterial cell wall components plays a role in the development and course of sepsis. However, most attention has been focused on lipopolysaccharide (LPS). We studied the ability of

  9. Establishment of disseminated intravascular coagulation (DIC) model by a single iv administration of Escherichia coli-derived lipopolysaccharide (LPS) to cynomolgus monkeys and evaluation of its pathophysiological status.

    Science.gov (United States)

    Minomo, Hirofumi; Inoue, Kengo; Sakaki, Shuko; Okazaki, Takanobu; Kobayashi, Kinji; Inoue, Kazuhiko; Miyata, Atsuro

    2017-02-01

    We prepared a DIC model by administrating LPS to cynomolgus monkeys, and investigated its potential for evaluations of new medicines for DIC therapy. Peripheral blood mononuclear cells (PBMC) collected from cynomolgus monkeys were incubated with LPS (8 types), and TNF-α levels in the media were measured. LPS from Escherichia coli (K-235) was most appropriate in terms of larger increases and smaller variation in TNF-α levels. PBMC from rats, cynomolgus monkeys or humans were incubated with LPS (K-235), and the TNF-α response to LPS was investigated. The response was comparable between cynomolgus monkeys and humans but small in rats. In an in vivo experiment, LPS (K-235) was administered once intravenously to cynomolgus monkeys with or without recombinant human thrombomodulin (rhTM) to investigate any changes in coagulation and fibrinolysis biomarkers and the suppressive effect of rhTM. The liver, kidney, and lung were examined histopathologically. Almost all of the changes resembled the pathophysiological status of human DIC and were suppressed by co-administration of rhTM. The DIC model resembling human DIC was established by LPS (K-235) treatment in cynomolgus monkeys, and therapeutic effect of rhTM was noted, suggesting that this model is useful in evaluations of the efficacy of new medicines for DIC therapy. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  10. Human Milk Shows Immunological Advantages Over Organic Milk Samples For Infants in the Presence of Lipopolysaccharide (LPS in 3D Energy Maps Using an Organic Nanobiomimetic Memristor/Memcapacitor

    Directory of Open Access Journals (Sweden)

    S-H. DUH

    2016-08-01

    Full Text Available Human milk is well known for its immunological advantages of protection and support for healthy early childhood cognitive development and prevention of chronic diseases over cow milk for infants. However, little is known about how the immunological advantages are linked to reduce Pathological High Frequency Oscillation (pHFO regarding neural synapse net energy outcomes when lipopolysaccharide (LPS attacks at a clinical concentration range compared with that in cow milk in a 3D energy map. We developed a nanostructure biomimetic memristor/memcapacitor device with a dual function of chronoamperometric (CA sensing/voltage sensing for the direct quantitative evaluation of immunological advantages between human milk and organic cow milk for infants in the presence of wide LPS concentration ranges; those ranges were between 5.0 pg/mL to 500 ng/mL and from 50 ng/mL to 1 µg/mL for both a CA and a voltage method, respectively. The Detection of Limit (DOL results are as follows: 3.73×10-18 g LPS vs. 1.2×10-16 g LPS in 40 µL milk samples using the 3.11×10-7cm3 voltage sensor and the 0.031cm2 CA sensor, respectively, under antibody-free and reagent-free conditions. The 3D energy map results show that cow milk is ten-times more prone to E. Coli attack, and the positive link was revealed that Pathological High Frequency Oscillation (pHFO formations occurred over the studied LPS concentration range from 50 ng/mL up to 1000 ng/mL from Rapid Eye Movement (REM sleep frequency, fast gamma frequency to Sharp Wave-Ripple Complexes (SPW- R frequency. There had no pHFO with human milk samples at Slow Wave Sleeping (SWS, REM and SPW- R frequencies. The microbiota in the human milk samples successfully overcame the endotoxin attack from E. coli bacteria, however the pHFO only occurred at fast gamma frequency linked with the LPS level ≥ 500 ng/mL. Organic milk samples show an order of magnitude lower synapse energy density compared with human milk at SWS for with

  11. Lentivirus-mediated interleukin-1β (IL-1β) knock-down in the hippocampus alleviates lipopolysaccharide (LPS)-induced memory deficits and anxiety- and depression-like behaviors in mice.

    Science.gov (United States)

    Li, Mengmeng; Li, Chenli; Yu, Hanjie; Cai, Xiongxiong; Shen, Xinbei; Sun, Xin; Wang, Jinting; Zhang, Yanhua; Wang, Chuang

    2017-09-20

    Recent evidence has suggested that peripheral inflammatory responses induced by lipopolysaccharides (LPS) play an important role in neuropsychiatric dysfunction in rodents. Interleukin-1β (IL-1β), a pro-inflammatory cytokine, has been proposed to be a key mediator in a variety of behavioral dysfunction induced by LPS in mice. Thus, inhibition of IL-1β may have a therapeutic benefit in the treatment of neuropsychiatric disorders. However, the precise underlying mechanism of knock-down of IL-1β in repairing behavioral changes by LPS remains unclear. The mice were treated with either IL-1β shRNA lentivirus or non-silencing shRNA control (NS shRNA) lentivirus by microinjection into the dentate gyrus (DG) regions of the hippocampus. After 7 days of recovery, LPS (1 mg/kg, i.p.) or saline was administered. The behavioral task for memory deficits was conducted in mice by the novel object recognition test (NORT), the anxiety-like behaviors were evaluated by the elevated zero maze (EZM), and the depression-like behaviors were examined by the sucrose preference test (SPT) and the forced swimming test (FST). Furthermore, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), nuclear factor erythroid-derived 2-like 2 (Nrf2), heme oxygenase 1 (HO1), IL-1β, tumor necrosis factor (TNF-α), neuropeptide VGF (non-acronymic), and brain-derived neurotrophic factor (BDNF) were assayed. Our results demonstrated that IL-1β knock-down in the hippocampus significantly attenuated the memory deficits and anxiety- and depression-like behaviors induced by LPS in mice. In addition, IL-1β knock-down ameliorated the oxidative and neuroinflammatory responses and abolished the downregulation of VGF and BDNF induced by LPS. Collectively, our findings suggest that IL-1β is necessary for the oxidative and neuroinflammatory responses produced by LPS and offers a novel drug target in the IL-1β/oxidative/neuroinflammatory/neurotrophic pathway for treating neuropsychiatric disorders

  12. Relationship between chemical composition and biological function of Pseudomonas aeruginosa lipopolysaccharide: effect on human neutrophil chemotaxis and oxidative burst

    DEFF Research Database (Denmark)

    Kharazmi, A; Fomsgaard, A; Conrad, R S

    1991-01-01

    There are conflicting data on the effect of bacterial lipopolysaccharides (LPS) on the function of human neutrophils. The present study was designed to examine the relationship between chemical composition and the modulatory effect of LPS on human neutrophil function. LPS was extracted from five...... of LPS. After preincubation, the chemotaxis and chemiluminescence of neutrophils to various stimuli were determined. It was shown that LPS from different strains did not exert the same degree of regulatory effect on neutrophil functions. LPS from strain 174-O:9 exerted the most pronounced effect...... no effect on neutrophil chemotaxis and a slight effect on chemiluminescence. The major differences in chemical composition of the LPS from these two strains are in the rhamnose and heptose content of the O side chain and in the alanine content of the core region. These data indicate that chemical...

  13. Experimental chronic Pseudomonas aeruginosa lung infection in rats. Non-specific stimulation with LPS reduces lethality as efficiently as specific immunization

    DEFF Research Database (Denmark)

    Lange, K H; Hougen, H P; Høiby, N

    1995-01-01

    stimulation of the non-specific defence mechanisms by Escherichia coli lipopolysaccharide (LPS) or P. aeruginosa sonicate, or the acquired specific immune response by vaccination with the same bacterial antigens. One day prior to challenge with P. aeruginosa embedded in alginate beads, rats were stimulated...... with either E. coli LPS or P. aeruginosa sonicate. Four and two weeks prior to challenge other rats were vaccinated with either E. coli LPS or P. aeruginosa sonicate. Controls did not receive any stimulation or vaccination. The lethality after challenge was lower in rats stimulated with E. coli LPS (p = 0...

  14. LPS-Induced Galectin-3 Oligomerization Results in Enhancement of Neutrophil Activation

    Science.gov (United States)

    Fermino, Marise Lopes; Polli, Claudia Danella; Toledo, Karina Alves; Liu, Fu-Tong; Hsu, Dan K.; Roque-Barreira, Maria Cristina; Pereira-da-Silva, Gabriela

    2011-01-01

    Galectin-3 (Gal 3) is a glycan-binding protein that can be secreted by activated macrophages and mast cells at inflammation sites and plays an important role in inflammatory diseases caused by Bacteria and their products, such as lipopolysaccharides (LPS). Although it is well established that Gal 3 can interact with LPS, the pathophysiological importance of LPS/Gal 3 interactions is not fully understood. Data presented herein demonstrate for the first time that the interaction of Gal 3, either via its carbohydrate binding C-terminal domain or via its N-terminal part, with LPS from different bacterial strains, enhances the LPS-mediated neutrophil activation in vitro. Gal 3 allowed low LPS concentrations (1 µg/mL without serum, 1 ng/mL with serum) to upregulate CD11b expression and reactive oxygen species (ROS) generation on human neutrophils in vitro and drastically enhanced the binding efficiency of LPS to the neutrophil surface. These effects required LPS preincubation with Gal 3, before neutrophil stimulation and involved specific Gal 3/LPS interaction. A C-terminal Gal-3 fragment, which retains the lectin domain but lacks the N-terminal part, was still able to bind both to Escherichia coli LPS and to neutrophils, but had lost the ability to enhance neutrophil response to LPS. This result emphasizes the importance of an N-terminus-mediated Gal 3 oligomerization induced by its interaction with LPS. Finally we demonstrated that Balb/C mice were more susceptible to LPS-mediated shock when LPS was pretreated with Gal 3. Altogether, these results suggest that multimeric interactions between Gal 3 oligomers and LPS potentiate its pro-inflammatory effects on neutrophils. PMID:22031821

  15. Gram-Negative Bacterial Lipopolysaccharide Stimulates Activin A Secretion from Human Amniotic Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Yumiko Abe

    2013-01-01

    Full Text Available Activin A is involved in inflammation. The present study was performed to clarify if lipopolysaccharide, a component of Gram-negative bacteria, stimulates activin A secretion from human amniotic epithelial cells and to determine if activin A plays a role in amnionitis. Fetal membranes were obtained during elective cesarean sections performed in full-term pregnancies of patients without systemic disease, signs of premature delivery, or fetal complications. Amniotic epithelial cells were isolated by trypsinization. The activin A concentrations in the culture media were measured by enzyme-linked immunosorbent assay, and cell proliferation was assessed by 5-bromo-2′-deoxyuridine incorporation. Amniotic epithelial cells secreted activin A in a cell density-dependent manner, and lipopolysaccharide (10 μg/mL enhanced the secretion at each cell density. Lipopolysaccharide (10–50 μg/mL also stimulated activin A secretion in a dose-dependent manner. Contrary to the effect of activin A secretion, lipopolysaccharide inhibited cell proliferation in amniotic epithelial cells. The present study suggests that lipopolysaccharide stimulation of activin A secretion may be a mechanism in the pathogenesis of amnionitis.

  16. Lipopolysaccharide (LPS)-stimulated iNOS Induction Is Increased by Glucosamine under Normal Glucose Conditions but Is Inhibited by Glucosamine under High Glucose Conditions in Macrophage Cells*

    Science.gov (United States)

    Hwang, Ji-Sun; Kwon, Mi-Youn; Kim, Kyung-Hong; Lee, Yunkyoung; Lyoo, In Kyoon; Kim, Jieun E.; Oh, Eok-Soo; Han, Inn-Oc

    2017-01-01

    We investigated the regulatory effect of glucosamine (GlcN) for the production of nitric oxide (NO) and expression of inducible NO synthase (iNOS) under various glucose conditions in macrophage cells. At normal glucose concentrations, GlcN dose dependently increased LPS-stimulated production of NO/iNOS. However, GlcN suppressed NO/iNOS production under high glucose culture conditions. Moreover, GlcN suppressed LPS-induced up-regulation of COX-2, IL-6, and TNF-α mRNAs under 25 mm glucose conditions yet did not inhibit up-regulation under 5 mm glucose conditions. Glucose itself dose dependently increased LPS-induced iNOS expression. LPS-induced MAPK and IκB-α phosphorylation did not significantly differ at normal and high glucose conditions. The activity of LPS-induced nuclear factor-κB (NF-κB) and DNA binding of c-Rel to the iNOS promoter were inhibited under high glucose conditions in comparison with no significant changes under normal glucose conditions. In addition, we found that the LPS-induced increase in O-GlcNAcylation as well as DNA binding of c-Rel to the iNOS promoter were further increased by GlcN under normal glucose conditions. However, both O-GlcNAcylation and DNA binding of c-Rel decreased under high glucose conditions. The NF-κB inhibitor, pyrrolidine dithiocarbamate, inhibited LPS-induced iNOS expression under high glucose conditions but it did not influence iNOS induction under normal glucose conditions. In addition, pyrrolidine dithiocarbamate inhibited NF-κB DNA binding and c-Rel O-GlcNAcylation only under high glucose conditions. By blocking transcription with actinomycin D, we found that stability of LPS-induced iNOS mRNA was increased by GlcN under normal glucose conditions. These results suggest that GlcN regulates inflammation by sensing energy states of normal and fuel excess. PMID:27927986

  17. Biophysical characterization of the interaction of Limulus polyphemus endotoxin neutralizing protein with lipopolysaccharide.

    Science.gov (United States)

    Andrä, Jörg; Garidel, Patrick; Majerle, Andreja; Jerala, Roman; Ridge, Richard; Paus, Erik; Novitsky, Tom; Koch, Michel H J; Brandenburg, Klaus

    2004-05-01

    Endotoxin-neutralizing protein (ENP) of the horseshoe crab is one of the most potent neutralizers of endotoxins [bacterial lipopolysaccharide (LPS)]. Here, we report on the interaction of LPS with recombinant ENP using a variety of physical and biological techniques. In biological assays (Limulus amebocyte lysate and tumour necrosis factor-alpha induction in human mononuclear cells), ENP causes a strong reduction of the immunostimulatory ability of LPS in a dose-dependent manner. Concomitantly, the accessible negative surface charges of LPS and lipid A (zeta potential) are neutralized and even converted into positive values. The gel to liquid crystalline phase transitions of LPS and lipid A shift to higher temperatures indicative of a rigidification of the acyl chains, however, the only slight enhancement of the transition enthalpy indicates that the hydrophobic moiety is not strongly disturbed. The aggregate structure of lipid A is converted from a cubic into a multilamellar phase upon ENP binding, whereas the secondary structure of ENP does not change due to the interaction with LPS. ENP contains a hydrophobic binding site to which the dye 1-anilino-8-sulfonic acid binds at a K(d) of 19 micro m, which is displaced by LPS. Because lipopolysaccharide-binding protein (LBP) is not able to bind to LPS when ENP and LPS are preincubated, tight binding of ENP to LPS can be deduced with a K(d) in the low nonomolar range. Importantly, ENP is able to incorporate by itself into target phospholipid liposomes, and is also able to mediate the intercalation of LPS into the liposomes thus acting as a transport protein in a manner similar to LBP. Thus, LPS-ENP complexes might enter target membranes of immunocompetent cells, but are not able to activate due to the ability of ENP to change LPS aggregates from an active into an inactive form.

  18. The specificity of Sushi peptides for endotoxin and anionic phospholipids: potential application of POPG as an adjuvant for anti-LPS strategies.

    Science.gov (United States)

    Li, P; Sun, M; Ho, B; Ding, J L

    2006-04-01

    Sushi peptides [S1 (Sushi 1 peptide) and S3] are derived from the LPS (lipopolysaccharide; also known as endotoxin)-binding domains of an LPS-sensitive serine protease, Factor C, from the horseshoe crab (Carcinoscorpius rotundicauda). S1 and S3 interact at high affinity with LPS. The intermolecular disulphide bonding in the S3 dimer is indispensable for its LPS binding, disruption and consequent neutralization. Simultaneously, the specific interaction between the Sushi peptides and bacterial membrane phospholipids further explains the selective propensity of these peptides for the gram-negative bacteria. Our findings yield insights into a complex molecular paradigm in which the juxtaposition of LPS molecules and the anionic phospholipid POPG (1-palmitoyl-2-oleoyl phosphatidylglycerol) on the bacterial outer membrane confers such interfacial properties which create the optimal environment for the interaction between the peptides and bacterial membrane lipids.

  19. Lipopolysaccharide (LPS)-mediated priming of toll-like receptor 4 enhances oxidant-induced prostaglandin E2biosynthesis in primary murine macrophages.

    Science.gov (United States)

    Zhang, Yan; Igwe, Orisa J

    2018-01-01

    Agonists and pseudo-agonists for toll-like receptor 4 (TLR4) are common in our environment. Thus, human exposure to these agents may result in "priming or sensitization" of TLR4. A body of evidence suggests that LPS-mediated sensitization of TLR4 can increase the magnitude of responses to exogenous agents in multiple tissues. We have previously shown that reactive oxygen and nitrogen species (RONS) stimulate TLR4. There is no evidence that LPS-primed TLR4 can influence the magnitude of responses to oxidants from either endogenous or exogenous sources. In the present study, we directly tested the hypothesis that LPS-primed TLR4 will sensitize primary murine peritoneal macrophages (pM) to oxidant-mediated prostaglandin E2 (PGE 2 ) production. We used potassium peroxychromate (PPC) and potassium peroxynitrite (PPN) as direct in vitro sources of exogenous RONS. Our results showed that a direct treatment with PPC or PPN alone as sources of exogenous oxidants had a limited effect on PGE 2 biosynthesis. In contrast, pM sensitized by prior incubation with LPS-EK, a TLR4-specific agonist, followed by oxidant stimulation exhibited increased transcriptional and translational expression of cyclooxygenase-2 (COX-2) with enhanced PGE 2 biosynthesis/production only in pM derived from TLR4-WT mice but not in TLR4-KO mice. Thus, we have shown a critical role for LPS-primed TLR4 in oxidant-induced inflammatory phenotypes that have the potential to initiate, propagate and maintain many human diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Expression of lung vascular and airway ICAM-1 after exposure to bacterial lipopolysaccharide

    DEFF Research Database (Denmark)

    Beck-Schimmer, B; Schimmer, R C; Warner, R L

    1997-01-01

    lavage fluids (BALFs) of animals after intratracheal instillation of LPS. Retrieved alveolar macrophages showed a small, significant, and transient increase in surface expression of ICAM-1. These data indicate, at the very least, a dual compartmentalized (vascular and airway) upregulation of ICAM-1 after...

  1. High-dose, short-term exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) affects the number of circulating neutrophils differently, but enhances the inflammatory responses of macrophages to lipopolysaccharide (LPS) in a similar fashion.

    Science.gov (United States)

    Qazi, Mousumi R; Bogdanska, Jasna; Butenhoff, John L; Nelson, B Dean; DePierre, Joseph W; Abedi-Valugerdi, Manuchehr

    2009-08-21

    Having found previously that high-dose, short-term dietary exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) suppresses adaptive immunity, in the present study we characterize the effects of these fluorochemicals on the innate immune system. Male C57BL/6 mice receiving 0.02% (w/w) PFOS or PFOA in their diet for 10 days exhibited a significant reduction in the numbers of total white blood cells (WBC), involving lymphopenia in both cases, but neutropenia only in response to treatment with PFOA. Moreover, both compounds also markedly reduced the number of macrophages (CD11b(+) cells) in the bone marrow, but not in the spleen or peritoneal cavity. The ex vivo production of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) by peritoneal macrophages isolated from animals treated with PFOA or PFOS was increased modestly. Moreover, both fluorochemicals markedly enhanced the ex vivo production of these same cytokines by peritoneal and bone marrow macrophages stimulated either in vitro or in vivo with lipopolysaccharide (LPS); whereas there was no such effect on splenic macrophages. The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by prior exposure to PFOA, but not by PFOS. None of these parameters of innate immunity were altered in animals receiving a dietary dose of these compounds that was 20-fold lower (0.001%, w/w). These findings reveal that in addition to suppressing adaptive immunity, high-dose, short-term exposure of mice to either PFOS or PFOA augments inflammatory responses to LPS, a potent activator of innate immunity.

  2. Induction of IL-1 during hemodialysis: Transmembrane passage of intact endotoxins (LPS)

    Energy Technology Data Exchange (ETDEWEB)

    Laude-Sharp, M.; Caroff, M.; Simard, L.; Pusineri, C.; Kazatchkine, M.D.; Haeffner-Cavaillon, N. (INSERM U 28, Hopital Broussais, Paris (France))

    1990-12-01

    Circulating monocytes of patients undergoing chronic hemodialysis are triggered to produce interleukin-1 (IL-1) in vivo. Intradialytic induction of IL-1 is associated with complement activation in patients dialyzed with first-use cellulose membranes. Chronic stimulation of IL-1 production occurs because of an yet unidentified mechanism in patients dialyzed with high permeability membranes. The present study demonstrates that intact bacterial lipopolysaccharide (LPS) molecules may cross cuprophan, AN69 and polysulfone membranes under in vitro conditions simulating in vivo hemodialysis. The experiments used purified LPS from Neisseria meningitidis and LPS from Pseudomonas testosteroni, a bacterial strain grown out from a clinically used dialysate. LPS were purified to homogeneity and radiolabeled. Transmembrane passage of 3H-labeled LPS was observed within the first five minutes of dialysis. A total of 0.1 to 1% of 3H-labeled LPS were recovered in the dialysate compartment after one hour of dialysis. High amounts of LPS, representing 40 to 70% of the amount originally present in the dialysate, were absorbed onto high permeability membranes. Low amounts of LPS were absorbed onto cuprophan membranes. The amount of LPS absorbed decreased with the concentration of LPS in the dialysate. LPS recovered from the blood compartment exhibited the same molecular weight as that used to contaminate the dialysate. Biochemically detectable transmembrane passage of LPS was not associated with that of material detectable using the limulus amebocyte lysate (LAL) assay. An IL-1-inducing activity was, however, detected in the blood compartment upon dialysis with high permeability membranes, as previously found by others with cuprophan membranes.

  3. A synthetic cyclic peptide derived from Limulus anti-lipopolysaccharide factor neutralizes endotoxin in vitro and in vivo.

    Science.gov (United States)

    Ren, Jian-Dong; Gu, Jin-Song; Gao, Hong-Fu; Xia, Pei-Yuan; Xiao, Guang-Xia

    2008-06-01

    Endotoxin, also known as lipopolysaccharide (LPS), is the major mediator of septic shock due to Gram-negative bacterial infections. Recently, much attention has been focused on cationic peptides which possess the potential to detoxify LPS. Limulus anti-LPS factor (LALF), a protein found in the horseshoe crab (Limulus polyphemus), has been proved with striking anti-LPS effects. We synthesized a cyclic peptide (CLP-19), and then investigated its bioactivity both in vitro and in vivo. The ability of CLP-19 to neutralize LPS in vitro was tested using a Limulus amebocyte lysate (LAL) assay and the LPS-binding affinity was measured with an affinity biosensor method. The synthetic peptide LALF31-52 (residues 31 to 52 of LALF) was used as the positive control peptide in this study. It was found that CLP-19 exhibited the significant activity to antagonize LPS without observable cytotoxicity effect on mouse macrophages. CLP-19 directly bound to LPS, and neutralized it in a dose-dependent manner in the LAL assay. Moreover, CLP-19 also showed the remarkable ability to protect mice from lethal LPS attack and to inhibit the LPS-induced tumor necrosis factor alpha (TNF-alpha) release by decreasing serum LPS in vivo. Our work suggests that this peptide is worthy of further investigation as a potential anti-LPS agent in the treatment of septic shock.

  4. Granzymes A and K differentially potentiate LPS-induced cytokine response

    Science.gov (United States)

    Wensink, Annette C; Kok, Helena M; Meeldijk, Jan; Fermie, Job; Froelich, Christopher J; Hack, C Erik; Bovenschen, Niels

    2016-01-01

    Granzymes are serine proteases that, upon release from cytotoxic cells, induce apoptosis in tumor cells and virally infected cells. In addition, a role of granzymes in inflammation is emerging. Recently, we have demonstrated that extracellular granzyme K (GrK) potentiates lipopolysaccharide (LPS)-induced cytokine response from monocytes. GrK interacts with LPS, disaggregates LPS micelles, and stimulates LPS-CD14 binding and Toll-like receptor signaling. Here we show that human GrA also potentiates cytokine responses in human monocytes initiated by LPS or Gram-negative bacteria. Similar to GrK, this effect is independent of GrA catalytic activity. Unlike GrK, however, GrA does not bind to LPS, has little influence on LPS micelle disaggregation, and does not augment LPS-CD14 complex formation. We conclude that GrA and GrK differentially modulate LPS-Toll-like receptor signaling in monocytes, suggesting functional redundancy among cytotoxic lymphocyte proteases in the anti-bacterial innate immune response. PMID:28028441

  5. A central role for the mammalian target of rapamycin in LPS-induced anorexia in mice.

    Science.gov (United States)

    Yue, Yunshuang; Wang, Yi; Li, Dan; Song, Zhigang; Jiao, Hongchao; Lin, Hai

    2015-01-01

    Bacterial lipopolysaccharide (LPS), also known as endotoxin, induces profound anorexia. However, the LPS-provoked pro-inflammatory signaling cascades and the neural mechanisms underlying the development of anorexia are not clear. Mammalian target of rapamycin (mTOR) is a key regulator of metabolism, cell growth, and protein synthesis. This study aimed to determine whether the mTOR pathway is involved in LPS-induced anorexia. Effects of LPS on hypothalamic gene/protein expression in mice were measured by RT-PCR or western blotting analysis. To determine whether inhibition of mTOR signaling could attenuate LPS-induced anorexia, we administered an i.c.v. injection of rapamycin, an mTOR inhibitor, on LPS-treated male mice. In this study, we showed that LPS stimulates the mTOR signaling pathway through the enhanced phosphorylation of mTOR(Ser2448) and p70S6K(Thr389). We also showed that LPS administration increased the phosphorylation of FOXO1(Ser256), the p65 subunit of nuclear factor kappa B (Panorexia by decreasing the phosphorylation of p70S6K(Thr389), FOXO1(Ser256), and FOXO1/3a(Thr) (24) (/) (32). These results suggest promising approaches for the prevention and treatment of LPS-induced anorexia. © 2015 Society for Endocrinology.

  6. Long-lasting pro-inflammatory suppression of microglia by LPS-preconditioning is mediated by RelB-dependent epigenetic silencing

    NARCIS (Netherlands)

    Schaafsma, W.; Zhang, X.; van Zomeren, K. C.; Jacobs, S.; Georgieva, P. B.; Wolf, S. A.; Kettenmann, H.; Janova, H.; Saiepour, N.; Hanisch, U. -K.; Meerlo, P.; van den Elsen, P. J.; Brouwer, N.; Boddeke, H. W. G. M.; Eggen, B. J. L.

    Microglia, the innate immune cells of the central nervous system (CNS), react to endotoxins like bacterial lipopolysaccharides (LPS) with a pronounced inflammatory response. To avoid excess damage to the CNS, the microglia inflammatory response needs to be tightly regulated. Here we report that a

  7. Comparison of Biological and Immunological Characterization of Lipopolysaccharides From Brucella abortus RB51 and S19.

    Science.gov (United States)

    Kianmehr, Zahra; Kaboudanian Ardestani, Sussan; Soleimanjahi, Hoorieh; Fotouhi, Fatemeh; Alamian, Saeed; Ahmadian, Shahin

    2015-11-01

    Brucella abortus RB51 is a rough stable mutant strain, which has been widely used as a live vaccine for prevention of brucellosis in cattle instead of B. abortus strain S19. B. abortus lipopolysaccharide (LPS) has unique properties in comparison to other bacterial LPS. In the current study, two types of LPS, smooth (S-LPS) and rough (R-LPS) were purified from B. abortus S19 and RB51, respectively. The aim of this study was to evaluate biological and immunological properties of purified LPS as an immunogenical determinant. Primarily, S19 and RB51 LPS were extracted and purified by two different modifications of the phenol water method. The final purity of LPS was determined by chemical analysis (2-keto-3-deoxyoctonate (KDO), glycan, phosphate and protein content) and different staining methods, following sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). C57BL/6 mice were immunized subcutaneously three times at biweekly intervals with the same amount of purified LPSs. The humoral immunity was evaluated by measuring specific IgG levels and also different cytokine levels, such as IFN-γ, TNF-α, IL-4 and IL-10, were determined for assessing T-cell immune response. Biochemical analysis data and SDS-PAGE profile showed that the chemical nature of S19 LPS is different from RB51 LPS. Both S and R-LPS induce an immune response. T-cell immune response induced by both S and R-LPS had almost the same pattern whereas S19 LPS elicited humoral immunity, which was higher than RB51 LPS. Purified LPS can be considered as a safe adjuvant and can be used as a component in prophylactic and therapeutic vaccines targeting infectious disease, cancer and allergies.

  8. Structural effects of the Azospirillum lipopolysaccharides in cell suspensions.

    Science.gov (United States)

    Matora, L Y; Serebrennikova, O B; Shchyogolev, S Y

    2001-01-01

    The structural influence of Azospirillum lipopolysaccharides (LPS) and lipopolysaccharide-protein complexes (LPPC) on carrot, erythrocyte, and bacterial cell suspensions was explored. The structural potentialities of O-specific polysaccharide fragments of LPS and protein fractions of LPPC were also evaluated. An ability to induce the formation of three kinds of structures in the cell suspensions was revealed depending on the chemical composition of the preparations used. The first and the second ones were connected with effects of cell aggregation (a relatively fast process) and agglutination (a relatively slow process). The third one resulted in phase separation of erythrocyte suspensions (a medium-speed process), with segregating the cells to a separate homogeneous liquid phase.

  9. Role of Muramyl Dipeptide in Lipopolysaccharide-Mediated Biological Activity and Osteoclast Activity

    Directory of Open Access Journals (Sweden)

    Hideki Kitaura

    2018-01-01

    Full Text Available Lipopolysaccharide (LPS is an endotoxin and bacterial cell wall component that is capable of inducing inflammation and immunological activity. Muramyl dipeptide (MDP, the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is another inflammation-inducing molecule that is ubiquitously expressed by bacteria. Several studies have shown that inflammation-related biological activities were synergistically induced by interactions between LPS and MDP. MDP synergistically enhances production of proinflammatory cytokines that are induced by LPS exposure. Injection of MDP induces lethal shock in mice challenged with LPS. LPS also induces osteoclast formation and pathological bone resorption; MDP enhances LPS induction of both processes. Furthermore, MDP enhances the LPS-induced receptor activator of NF-κB ligand (RANKL expression and toll-like receptor 4 (TLR4 expression both in vivo and in vitro. Additionally, MDP enhances LPS-induced mitogen-activated protein kinase (MAPK signaling in stromal cells. Taken together, these findings suggest that MDP plays an important role in LPS-induced biological activities. This review discusses the role of MDP in LPS-mediated biological activities, primarily in relation to osteoclastogenesis.

  10. Xanthohumol ameliorates lipopolysaccharide (LPS-induced acute lung injury via induction of AMPK/GSK3β-Nrf2 signal axis

    Directory of Open Access Journals (Sweden)

    Hongming Lv

    2017-08-01

    Full Text Available Abundant natural flavonoids can induce nuclear factor-erythroid 2 related factor 2 (Nrf2 and/or AMP-activated protein kinase (AMPK activation, which play crucial roles in the amelioration of various inflammation- and oxidative stress-induced diseases, including acute lung injury (ALI. Xanthohumol (Xn, a principal prenylflavonoid, possesses anti-inflammation and anti-oxidant activities. However, whether Xn could protect from LPS-induced ALI through inducing AMPK/Nrf2 activation and its downstream signals, are still poorly elucidated. Accordingly, we focused on exploring the protective effect of Xn in the context of ALI and the involvement of underlying molecular mechanisms. Our findings indicated that Xn effectively alleviated lung injury by reduction of lung W/D ratio and protein levels, neutrophil infiltration, MDA and MPO formation, and SOD and GSH depletion. Meanwhile, Xn significantly lessened histopathological changes, reactive oxygen species (ROS generation, several cytokines secretion, and iNOS and HMGB1 expression, and inhibited Txnip/NLRP3 inflammasome and NF-κB signaling pathway activation. Additionally, Xn evidently decreased t-BHP-stimulated cell apoptosis, ROS generation and GSH depletion but increased various anti-oxidative enzymes expression regulated by Keap1-Nrf2/ARE activation, which may be associated with AMPK and GSK3β phosphorylation. However, Xn-mediated inflammatory cytokines and ROS production, histopathological changes, Txnip/NLRP3 inflammasome and NF-κB signaling pathway in WT mice were remarkably abrogated in Nrf2-/- mice. Our experimental results firstly provided a support that Xn effectively protected LPS-induced ALI against oxidative stress and inflammation damage which are largely dependent upon upregulation of the Nrf2 pathway via activation of AMPK/GSK3β, thereby suppressing LPS-activated Txnip/NLRP3 inflammasome and NF-κB signaling pathway.

  11. Epinecidin-1 protects mice from LPS-induced endotoxemia and cecal ligation and puncture-induced polymicrobial sepsis.

    Science.gov (United States)

    Su, Bor-Chyuan; Huang, Han-Ning; Lin, Tai-Wen; Hsiao, Chwan-Deng; Chen, Jyh-Yih

    2017-12-01

    The antimicrobial peptide, epinecidin-1 (Epi), was identified from Epinephelus coioides and may have clinical application for treating sepsis. Epi has been shown to ameliorate antibiotic-resistant bacteria-induced sepsis in mice, but further evaluation in mixed-flora models and a description of the protective mechanisms are essential to establish this peptide as a potential therapeutic. Therefore, we first tested the protective effects of Epi against polymicrobial sepsis-induced bactericidal infection, inflammation and lung injury that result from cecal ligation and puncture in mice. Furthermore, since lipopolysaccharide (LPS) is a key inducer of inflammation during bacterial infection and sepsis, we also tested the LPS-antagonizing activity and related mechanisms of Epi-mediated protection in mice with LPS-induced endotoxemia and LPS-treated Raw264.7 mouse macrophage cells. Epi rescued mice from both polymicrobial sepsis and endotoxemia after delayed administration and suppressed both lung and systemic inflammatory responses, while attenuating lung injury and diminishing bacterial load. In vitro studies revealed that Epi suppressed LPS-induced inflammatory cytokine production. Mechanistically, Epi disrupted the interaction between LPS and LPS binding protein, competed with LPS for binding on the cell surface, and inhibited Toll-like receptor 4 endocytosis, resulting in inhibition of LPS-induced reactive oxygen species/p38/Akt/NF-κB signaling and subsequent cytokine production. Overall, our results demonstrate that Epi is a promising therapeutic agent for endotoxemia and polymicrobial sepsis. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. CD36 Differently Regulates Macrophage Responses to Smooth and Rough Lipopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Rafał Biedroń

    Full Text Available Lipopolysaccharide (LPS is the major pathogen-associated molecular pattern of Gram-negative bacterial infections, and includes smooth (S-LPS and rough (R-LPS chemotypes. Upon activation by LPS through CD14, TLR4/MD-2 heterodimers sequentially induce two waves of intracellular signaling for macrophage activation: the MyD88-dependent pathway from the plasma membrane and, following internalization, the TRIF-dependent pathway from endosomes. We sought to better define the role of scavenger receptors CD36 and CD204/SR-A as accessory LPS receptors that can contribute to pro-inflammatory and microbicidal activation of macrophages. We have found that CD36 differently regulates activation of mouse macrophages by S-LPS versus R-LPS. The ability of CD36 to substitute for CD14 in loading R-LPS, but not S-LPS onto TLR4/MD-2 allows CD14-independent macrophage responses to R-LPS. Conversely, S-LPS, but not R-LPS effectively stimulates CD14 binding to CD36, which favors S-LPS transfer from CD14 onto TLR4/MD-2 under conditions of low CD14 occupancy with S-LPS in serum-free medium. In contrast, in the presence of serum, CD36 reduces S-LPS binding to TLR4/MD-2 and the subsequent MyD88-dependent signaling, by mediating internalization of S-LPS/CD14 complexes. Additionally, CD36 positively regulates activation of TRIF-dependent signaling by both S-LPS and R-LPS, by promoting TLR4/MD-2 endocytosis. In contrast, we have found that SR-A does not function as a S-LPS receptor. Thus, by co-operating with CD14 in both R- and S-LPS loading onto TLR4/MD-2, CD36 can enhance the sensitivity of tissue-resident macrophages in detecting infections by Gram-negative bacteria. However, in later phases, following influx of serum to the infection site, the CD36-mediated negative regulation of MyD88-dependent branch of S-LPS-induced TLR4 signaling might constitute a mechanism to prevent an excessive inflammatory response, while preserving the adjuvant effect of S-LPS for adaptive

  13. Fetal lipopolysaccharide exposure modulates diet-dependent gut maturation and sensitivity to necrotising enterocolitis in pre-term pigs

    DEFF Research Database (Denmark)

    Cilieborg, Malene Skovsted; Schmidt, Mette; Skovgaard, Kerstin

    2011-01-01

    that improve resistance towards necrotising enterocolitis (NEC) in pre-term neonates. At approximately 85% gestation, pig fetuses were injected intramuscularly with saline or LPS (0.014 mg/kg), or intra-amniotically with LPS (0.4 mg/kg). Pigs were delivered by caesarean section 3–5 d later and fed colostrum (C......Uterine infections during pregnancy predispose to pre-term birth and postnatal morbidity, but it is unknown how prenatal bacterial exposure affects maturation of the immature gut. We hypothesised that a prenatal exposure to gram-negative lipopolysaccharide (LPS) has immunomodulatory effects...

  14. Identification of a novel compound that inhibits iNOS and COX-2 expression in LPS-stimulated macrophages from Schisandra chinensis

    International Nuclear Information System (INIS)

    Lee, You Jin; Park, Sun Young; Kim, Sun Gun; Park, Da Jung; Kang, Jum Soon; Lee, Sang Joon; Yoon, Sik; Kim, Young Hun; Bae, Yoe-Sik; Choi, Young-Whan

    2010-01-01

    A novel α-iso-cubebenol, which has anti-inflammatory effects in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, was isolated from the fruits of Schisandra chinensis. α-iso-cubebenol inhibited LPS-induced nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) production. Consistent with these findings, α-iso-cubebenol also reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2 at the protein and mRNA levels in a concentration-dependent manner. α-iso-cubebenol also inhibited LPS-induced nuclear translocation of the NF-κB p65 subunit. Furthermore, α-iso-cubebenol suppressed the phosphorylation of ERK, JNK, and p38 kinase induced by LPS. Since the novel α-iso-cubebenol blocked the production of several pro-inflammatory mediators induced by LPS in macrophages, the molecule can be useful material for the development of anti-inflammatory agents against bacterial infections or endotoxin.

  15. The role of lipopolysaccharide and peptidoglycan, two glycosylated bacterial microbe-associated molecular patterns (MAMPs), in plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2012-01-01

    innate immune system through the action of pattern recognition receptors (PRRs). A greater insight into the mechanisms of MAMP recognition and the description of PRRs for different microbial glycoconjugates will have considerable impact on the improvement of plant health and disease resistance. Here...... to as ‘innate immunity’. Innate immunity is the first line of defence against invading microorganisms in vertebrates and the only line of defence in invertebrates and plants. Bacterial glycoconjugates, such as lipopolysaccharides (LPSs) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN......) from the cell walls of both Gram-positive and Gram-negative bacteria, have been found to act as elicitors of plant innate immunity. These conserved, indispensable, microbe-specific molecules are also referred to as ‘microbe-associated molecular patterns’ (MAMPs). MAMPs are recognized by the plant...

  16. Effect of different methods of sterilization on the inactivation of bacterial endotoxin (LPS in endodontic files Efeito de diferentes métodos de esterilização na inativação da endotoxina bacteriana (LPS presnete em limas endodônicas

    Directory of Open Access Journals (Sweden)

    Raquel Assed Bezerra da Silva

    2007-06-01

    Full Text Available This study evaluated the presence of lipopolysaccharide (LPS in endodontic files after in vitro contamination with E. coli LPS and sterilization in dry heat or wet heat, with or without previous immersion in a Ca(OH2 suspension. LPS was quantified using the Kinetic QCL TM test and data were analyzed statistically by the t-test. LPS was quantified only in the contaminated group, not submitted to any immersion or sterilization procedure (0.262±0.1296 endotoxin units/mL (p=0.0003. In conclusion, both wet heat and dry heat sterilization were effective in inactivating LPS without the need of previous immersion of the files in a Ca(OH2 suspension.Este estudo avaliou a presença de endotoxina (LPS em limas endodônticas após contaminação in vitro com LPS de E. coli e esterilização em autoclave ou forno de Pasteur, com ou sem imersão prévia em suspensão de hidróxido de cálcio. A quantificação do LPS foi efetuada pelo teste Kinetic QCL TM, e os resultados submetidos à análise estatística (teste t. LPS foi quantificado apenas no grupo contaminado e não submetido a nenhum procedimento de imersão ou esterilização (0,262±0,1296 unidades de endotoxina/mL (p=0,0003. Concluiu-se que a esterilização das limas em autoclave ou forno de Pasteur foi eficaz na inativação do LPS, não sendo necessária a sua imersão prévia em suspensão de hidróxido de cálcio.

  17. Multiple mechanisms involved in diabetes protection by lipopolysaccharide in non-obese diabetic mice

    International Nuclear Information System (INIS)

    Wang, Jun; Cao, Hui; Wang, Hongjie; Yin, Guoxiao; Du, Jiao; Xia, Fei; Lu, Jingli; Xiang, Ming

    2015-01-01

    Toll-like receptor 4 (TLR4) activation has been proposed to be important for islet cell inflammation and eventually β cell loss in the course of type 1 diabetes (T1D) development. However, according to the “hygiene hypothesis”, bacterial endotoxin lipopolysaccharide (LPS), an agonist on TLR4, inhibits T1D progression. Here we investigated possible mechanisms for the protective effect of LPS on T1D development in non-obese diabetic (NOD) mice. We found that LPS administration to NOD mice during the prediabetic state neither prevented nor reversed insulitis, but delayed the onset and decreased the incidence of diabetes, and that a multiple-injection protocol is more effective than a single LPS intervention. Further, LPS administration suppressed spleen T lymphocyte proliferation, increased the generation of CD4 + CD25 + Foxp3 + regulatory T cells (Tregs), reduced the synthesis of strong Th1 proinflammatory cytokines, and downregulated TLR4 and its downstream MyD88-dependent signaling pathway. Most importantly, multiple injections of LPS induced a potential tolerogenic dendritic cell (DC) subset with low TLR4 expression without influencing the DC phenotype. Explanting DCs from repeated LPS-treated NOD mice into NOD/SCID diabetic mice conferred sustained protective effects against the progression of diabetes in the recipients. Overall, these results suggest that multiple mechanisms are involved in the protective effects of LPS against the development of diabetes in NOD diabetic mice. These include Treg induction, down-regulation of TLR4 and its downstream MyD88-dependent signaling pathway, and the emergence of a potential tolerogenic DC subset. - Highlights: • Administration of lipopolysaccharide (LPS) prevented type 1 diabetes in NOD mice. • Downregulating TLR4 level and MyD88-dependent pathway contributed to protection of LPS. • LPS administration also hampered DC maturation and promoted Treg differentiation

  18. Multiple mechanisms involved in diabetes protection by lipopolysaccharide in non-obese diabetic mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Pharmacology, College of Medicine, Wuhan University of Science and Technology, Wuhan (China); Cao, Hui [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wang, Hongjie [Section of Neurobiology, Torrey Pines Institute for Molecular Studies, Port Saint Lucie, FL (United States); Yin, Guoxiao; Du, Jiao; Xia, Fei; Lu, Jingli [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Xiang, Ming, E-mail: xiangming@mails.tjmu.edu.cn [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)

    2015-06-15

    Toll-like receptor 4 (TLR4) activation has been proposed to be important for islet cell inflammation and eventually β cell loss in the course of type 1 diabetes (T1D) development. However, according to the “hygiene hypothesis”, bacterial endotoxin lipopolysaccharide (LPS), an agonist on TLR4, inhibits T1D progression. Here we investigated possible mechanisms for the protective effect of LPS on T1D development in non-obese diabetic (NOD) mice. We found that LPS administration to NOD mice during the prediabetic state neither prevented nor reversed insulitis, but delayed the onset and decreased the incidence of diabetes, and that a multiple-injection protocol is more effective than a single LPS intervention. Further, LPS administration suppressed spleen T lymphocyte proliferation, increased the generation of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T cells (Tregs), reduced the synthesis of strong Th1 proinflammatory cytokines, and downregulated TLR4 and its downstream MyD88-dependent signaling pathway. Most importantly, multiple injections of LPS induced a potential tolerogenic dendritic cell (DC) subset with low TLR4 expression without influencing the DC phenotype. Explanting DCs from repeated LPS-treated NOD mice into NOD/SCID diabetic mice conferred sustained protective effects against the progression of diabetes in the recipients. Overall, these results suggest that multiple mechanisms are involved in the protective effects of LPS against the development of diabetes in NOD diabetic mice. These include Treg induction, down-regulation of TLR4 and its downstream MyD88-dependent signaling pathway, and the emergence of a potential tolerogenic DC subset. - Highlights: • Administration of lipopolysaccharide (LPS) prevented type 1 diabetes in NOD mice. • Downregulating TLR4 level and MyD88-dependent pathway contributed to protection of LPS. • LPS administration also hampered DC maturation and promoted Treg differentiation.

  19. Lipopolysaccharide enhances the cytotoxicity of 2-chloroethyl ethyl sulfide

    Directory of Open Access Journals (Sweden)

    Qui Min

    2003-01-01

    Full Text Available Abstract Background The bacterial endotoxin, lipopolysaccharide (LPS, is a well-characterized inflammatory factor found in the cell wall of Gram-negative bacteria. In this investigation, we studied the cytotoxic interaction between 2-chloroethyl ethyl sulfide (CEES or ClCH2CH2SCH2CH3 and LPS using murine RAW264.7 macrophages. CEES is a sulfur vesicating agent and is an analog of 2,2'-dichlorodiethyl sulfide (sulfur mustard. LPS is a ubiquitous natural agent found in the environment. The ability of LPS and other inflammatory agents (such as TNF-alpha and IL-1beta to modulate the toxicity of CEES is likely to be an important factor in the design of effective treatments. Results RAW 264.7 macrophages stimulated with LPS were found to be more susceptible to the cytotoxic effect of CEES than unstimulated macrophages. Very low levels of LPS (20 ng/ml dramatically enhanced the toxicity of CEES at concentrations greater than 400 μM. The cytotoxic interaction between LPS and CEES reached a maximum 12 hours after exposure. In addition, we found that tumor necrosis factor-alpha (TNF-alpha and interleukin-1-beta (IL-1-beta as well as phorbol myristate acetate (PMA also enhanced the cytotoxic effects of CEES but to a lesser extent than LPS. Conclusion Our in vitro results suggest the possibility that LPS and inflammatory cytokines could enhance the toxicity of sulfur mustard. Since LPS is a ubiquitous agent in the natural environment, its presence is likely to be an important variable influencing the cytotoxicity of sulfur mustard toxicity. We have initiated further experiments to determine the molecular mechanism whereby the inflammatory process influences sulfur mustard cytotoxicity.

  20. Lipopolysaccharide modulates the vector-pathogen interface of the xylem-limited phytopathogen, Xylella fastidiosa, the causal agent of Pierce’s disease of grapevine

    Science.gov (United States)

    Xylella fastidiosa Wells et al. is a gram-negative, insect-transmitted bacterium that causes a lethal disease of grapevine called Pierce’s disease. Lipopolysaccharide (LPS) is the most dominant macromolecule displayed on the cell surface of gram-negative bacteria. Bacterial interactions with the env...

  1. The lipopolysaccharide lipid-a long chain fatty acid is important for rhizobium leguminosarum growth and stress adaptation in free-living and nodule environments

    Science.gov (United States)

    Rhizobium bacteria live in soil and plant environments, are capable of inducing symbiotic nodules on legumes, invade these nodules, and develop into bacteroids that fix atmospheric nitrogen into ammonium. Lipopolysaccharide (LPS) is anchored in the bacterial outer membrane through a specialized lipi...

  2. The Effect of the Aerial Part of Lindera akoensis on Lipopolysaccharides (LPS-Induced Nitric Oxide Production in RAW264.7 Cells

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    Yen-Hsueh Tseng

    2013-04-01

    Full Text Available Four new secondary metabolites, 3α-((E-Dodec-1-enyl-4β-hydroxy-5β-methyldihydrofuran-2-one (1, linderinol (6, 4'-O-methylkaempferol 3-O-α-L-(4''-E-p-coumaroylrhamnoside (11 and kaempferol 3-O-α-L-(4''-Z-p-coumaroylrhamnoside (12 with eleven known compounds—3-epilistenolide D1 (2, 3-epilistenolide D2 (3, (3Z,4α,5β-3-(dodec-11-ynylidene-4-hydroxy-5-methylbutanolide (4, (3E,4β,5β-3-(dodec-11-ynylidene-4-hydroxy-5-methylbutanolide (5, matairesinol (7, syringaresinol (8, (+-pinoresinol (9, salicifoliol (10, 4''-p-coumaroylafzelin (13, catechin (14 and epicatechin (15—were first isolated from the aerial part of Lindera akoensis. Their structures were determined by detailed analysis of 1D- and 2D-NMR spectroscopic data. All of the compounds isolated from Lindera akoensis showed that in vitro anti-inflammatory activity decreases the LPS-stimulated production of nitric oxide (NO in RAW 264.7 cell, with IC50 values of 4.1–413.8 µM.

  3. An adenine nucleotide translocase (ANT) gene from Apostichopus japonicus; molecular cloning and expression analysis in response to lipopolysaccharide (LPS) challenge and thermal stress.

    Science.gov (United States)

    Liu, Qiu-Ning; Chai, Xin-Yue; Tu, Jie; Xin, Zhao-Zhe; Li, Chao-Feng; Jiang, Sen-Hao; Zhou, Chun-Lin; Tang, Bo-Ping

    2016-02-01

    The adenine nucleotide translocases (ANTs) play a vital role in energy metabolism via ADP/ATP exchange in eukaryotic cells. Apostichopus japonicus (Echinodermata: Holothuroidea) is an important economic species in China. Here, a cDNA representing an ANT gene of A. japonicus was isolated and characterized from respiratory tree and named AjANT. The full-length AjANT cDNA is 1924 bp, including a 5'-untranslated region (UTR) of 38 bp, 3'-UTR of 980 bp and an open reading frame (ORF) of 906 bp encoding a polypeptide of 301 amino acids. The protein contains three homologous repeat Mito_carr domains (Pfam00153). The deduced AjANT protein sequence has 49-81% in comparison to ANT proteins from other individuals. The predicted tertiary structure of AjANT protein is highly similar to animal ANT proteins. Phylogenetic analysis showed that the AjANT is closely related to Holothuroidea ANT genes. Real-time quantitative reverse transcription-PCR (qPCR) analysis showed that AjANT expression is higher in the respiratory tree than in other examined tissues. After thermal stress or LPS challenge, expression of AjANT was significantly fluctuant compared to the control. These results suggested that changes in the expression of ANT gene might be involved in immune defense and in protecting A. japonicus against thermal stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. LPS inmobilization on porous and non-porous supports as an approach for the isolation of anti-LPS host-defense peptides.

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    Carlos eLopez-Abarrategui

    2013-12-01

    Full Text Available Lipopolysaccharides (LPS are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no FDA-approved drug yet that interacts directly against LPS. Cationic host defense peptides could be an alternative solution since they possess both antimicrobial and antiseptic properties. Host defense peptides are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different host defense peptides (HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating host defense peptides that recognize LPS. This approach could expand the rational search for anti-LPS host defense peptides.

  5. Structural analysis of lipopolysaccharide produced by Heddleston serovars 10, 11, 12 and 15 and the identification of a new Pasteurella multocida lipopolysaccharide outer core biosynthesis locus, L6.

    Science.gov (United States)

    Harper, Marina; St Michael, Frank; John, Marietta; Steen, Jason; van Dorsten, Lieke; Parnas, Henrietta; Vinogradov, Evgeny; Adler, Ben; Cox, Andrew D; Boyce, John D

    2014-07-01

    Pasteurella multocida is a Gram-negative bacterial pathogen classified into 16 serovars based on lipopolysaccharide (LPS) antigens. Previously, we have characterized the LPS outer core biosynthesis loci L1, L2, L3, L5 and L7, and have elucidated the full range of LPS structures associated with each. In this study, we have determined the LPS structures produced by the type strains representing the serovars 10, 11, 12 and 15 and characterized a new LPS outer core biosynthesis locus, L6, common to all. The L6 outer core biosynthesis locus shares significant synteny with the L3 locus but due to nucleotide divergence, gene duplication and gene redundancy, the L6 and L3 LPS outer cores are structurally distinct. Using LPS structural and genetic differences identified in each L6 strain, we have predicted a role for most of the L6 glycosyltransferases in LPS assembly. Importantly, we have identified two glycosyltransferases, GctD and GatB, that differ by one amino acid, A162T, but use different donor sugars [uridine diphosphate (UDP)-Glc and UDP-Gal, respectively]. The longest outer core oligosaccharide, produced by the serovar 12 type strain, contained a terminal region consisting of β-Gal-(1,4)-β-GlcNAc-(1,3)-β-Gal-(1,4)-β-Glc that was identical in structure to the vertebrate glycosphingolipid, paragloboside. Mimicry of host glycosphingolipids has been observed previously in P. multocida strains belonging to L3 LPS genotype, which produce LPS similar in structure to the globo-series of glycosphingolipids. The expression of a paragloboside-like oligosaccharide on the LPS produced by the serovar 12 type strain indicates that strains belonging to the L6 LPS genotype may also engage in molecular mimicry. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. EFhd2/swiprosin-1 regulates LPS-induced macrophage recruitment via enhancing actin polymerization and cell migration.

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    Tu, Ye; Zhang, Lichao; Tong, Lingchang; Wang, Yue; Zhang, Su; Wang, Rongmei; Li, Ling; Wang, Zhibin

    2018-02-01

    Macrophage motility is vital in innate immunity, which contributes strategically to the defensive inflammation process. During bacterial infection, lipopolysaccharide (LPS) potently activates the migration of macrophages via the NF-κB/iNOS/c-Src signaling pathway. However, the downstream region of c-Src that participates in macrophage migration is unclear. EFhd2, a novel actin bundling protein, was evaluated for its role in LPS-stimulated macrophage migration in this study. We found that LPS stimulated the up-regulation, tyrosine phosphorylation and membrane translocation of EFhd2 in macrophages. The absence of EFhd2 inhibited the recruitment of macrophages in the lungs of LPS-induced septic mice. LPS-induced macrophage migration was neutralized by the deletion of EFhd2. EFhd2-mediated up-regulation of NFPs (including Rac1/Cdc42, N-WASP/WAVE2 and Arp2/3 complex) induced by LPS could be used to explain the role of EFhd2 in promoting actin polymerization. Furthermore, the purified EFhd2 could directly promote actin polymerization in vitro. Dasatinib, a c-Src specific inhibitor, inhibited the up-regulation of EFhd2 stimulated by LPS. Therefore, our study demonstrated that EFhd2 might be involved in LPS-stimulated macrophage migration, which provides a potential target for LPS-activated c-Src during macrophage mobilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Humanized TLR4/MD-2 mice reveal LPS recognition differentially impacts susceptibility to Yersinia pestis and Salmonella enterica.

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    Adeline M Hajjar

    Full Text Available Although lipopolysaccharide (LPS stimulation through the Toll-like receptor (TLR-4/MD-2 receptor complex activates host defense against Gram-negative bacterial pathogens, how species-specific differences in LPS recognition impact host defense remains undefined. Herein, we establish how temperature dependent shifts in the lipid A of Yersinia pestis LPS that differentially impact recognition by mouse versus human TLR4/MD-2 dictate infection susceptibility. When grown at 37°C, Y. pestis LPS is hypo-acylated and less stimulatory to human compared with murine TLR4/MD-2. By contrast, when grown at reduced temperatures, Y. pestis LPS is more acylated, and stimulates cells equally via human and mouse TLR4/MD-2. To investigate how these temperature dependent shifts in LPS impact infection susceptibility, transgenic mice expressing human rather than mouse TLR4/MD-2 were generated. We found the increased susceptibility to Y. pestis for "humanized" TLR4/MD-2 mice directly paralleled blunted inflammatory cytokine production in response to stimulation with purified LPS. By contrast, for other Gram-negative pathogens with highly acylated lipid A including Salmonella enterica or Escherichia coli, infection susceptibility and the response after stimulation with LPS were indistinguishable between mice expressing human or mouse TLR4/MD-2. Thus, Y. pestis exploits temperature-dependent shifts in LPS acylation to selectively evade recognition by human TLR4/MD-2 uncovered with "humanized" TLR4/MD-2 transgenic mice.

  8. Humanized TLR4/MD-2 mice reveal LPS recognition differentially impacts susceptibility to Yersinia pestis and Salmonella enterica.

    Science.gov (United States)

    Hajjar, Adeline M; Ernst, Robert K; Fortuno, Edgardo S; Brasfield, Alicia S; Yam, Cathy S; Newlon, Lindsay A; Kollmann, Tobias R; Miller, Samuel I; Wilson, Christopher B

    2012-01-01

    Although lipopolysaccharide (LPS) stimulation through the Toll-like receptor (TLR)-4/MD-2 receptor complex activates host defense against Gram-negative bacterial pathogens, how species-specific differences in LPS recognition impact host defense remains undefined. Herein, we establish how temperature dependent shifts in the lipid A of Yersinia pestis LPS that differentially impact recognition by mouse versus human TLR4/MD-2 dictate infection susceptibility. When grown at 37°C, Y. pestis LPS is hypo-acylated and less stimulatory to human compared with murine TLR4/MD-2. By contrast, when grown at reduced temperatures, Y. pestis LPS is more acylated, and stimulates cells equally via human and mouse TLR4/MD-2. To investigate how these temperature dependent shifts in LPS impact infection susceptibility, transgenic mice expressing human rather than mouse TLR4/MD-2 were generated. We found the increased susceptibility to Y. pestis for "humanized" TLR4/MD-2 mice directly paralleled blunted inflammatory cytokine production in response to stimulation with purified LPS. By contrast, for other Gram-negative pathogens with highly acylated lipid A including Salmonella enterica or Escherichia coli, infection susceptibility and the response after stimulation with LPS were indistinguishable between mice expressing human or mouse TLR4/MD-2. Thus, Y. pestis exploits temperature-dependent shifts in LPS acylation to selectively evade recognition by human TLR4/MD-2 uncovered with "humanized" TLR4/MD-2 transgenic mice.

  9. Synthetic anti-endotoxin peptides inhibit cytoplasmic LPS-mediated responses.

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    Pfalzgraff, Anja; Heinbockel, Lena; Su, Qi; Brandenburg, Klaus; Weindl, Günther

    2017-09-15

    Toll-like receptor (TLR) 4-independent recognition of lipopolysaccharide (LPS) in the cytosol by inflammatory caspases leads to non-canonical inflammasome activation and induction of IL-1 secretion and pyroptosis. The discovery of this novel mechanism has potential implications for the development of effective drugs to treat sepsis since LPS-mediated hyperactivation of caspases is critically involved in endotoxic shock. Previously, we demonstrated that Pep19-2.5, a synthetic anti-endotoxin peptide, efficiently neutralises pathogenicity factors of Gram-negative and Gram-positive bacteria and protects against sepsis in vivo. Here, we report that Pep19-2.5 inhibits the effects of cytoplasmic LPS in human myeloid cells and keratinocytes. In THP-1 monocytes and macrophages, the peptide strongly reduced secretion of IL-1β and LDH induced by intracellular LPS. In contrast, the TLR4 signaling inhibitor TAK-242 abrogates LPS-induced TNF and IL-1β secretion, but not pyroptotic cell death. Furthermore, Pep19-2.5 suppressed LPS-induced HMGB-1 production and caspase-1 activation in THP-1 monocytes. Consistent with this observation, we found impaired IL-1β and IL-1α release in LPS-stimulated primary monocytes in the presence of Pep19-2.5 and reduced LDH release and IL-1B and IL-1A expression in LPS-transfected HaCaT keratinocytes. Additionally, Pep19-2.5 completely abolished IL-1β release induced by LPS/ATP in macrophages via canonical inflammasome activation. In conclusion, we provide evidence that anti-endotoxin peptides inhibit the inflammasome/IL-1 axis induced by cytoplasmic LPS sensing in myeloid cells and keratinocytes and activation of the classical inflammasome by LPS/ATP which may contribute to the protection against bacterial sepsis and skin infections with intracellular Gram-negative bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Lipopolysaccharide-induced Pulpitis Up-regulates TRPV1 in Trigeminal Ganglia

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    Chung, M.-K.; Lee, J.; Duraes, G.; Ro, J.Y.

    2011-01-01

    Tooth pain often accompanies pulpitis. Accumulation of lipopolysaccharides (LPS), a product of Gram-negative bacteria, is associated with painful clinical symptoms. However, the mechanisms underlying LPS-induced tooth pain are not clearly understood. TRPV1 is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and hyperalgesia under inflammation or injury. Although TRPV1 is expressed in pulpal afferents, it is not known whether the application of LPS to teeth modulates TRPV1 in trigeminal nociceptors. By assessing the levels of protein and transcript of TRPV1 in mouse trigeminal ganglia, we demonstrate that dentinal application of LPS increases the expression of TRPV1. Our results suggest that the up-regulation of TRPV1 in trigeminal nociceptors following bacterial infection could contribute to hyperalgesia under pulpitis conditions. PMID:21712529

  11. Lipopolysaccharide impairs hepatocyte ureagenesis from ammonia: involvement of mitochondrial aquaporin-8.

    Science.gov (United States)

    Soria, Leandro R; Marrone, Julieta; Molinas, Sara M; Lehmann, Guillermo L; Calamita, Giuseppe; Marinelli, Raúl A

    2014-05-02

    We recently reported that hepatocyte mitochondrial aquaporin-8 (mtAQP8) channels facilitate the uptake of ammonia and its metabolism into urea. Here we studied the effect of bacterial lipopolysaccharides (LPS) on ammonia-derived ureagenesis. In LPS-treated rats, hepatic mtAQP8 protein expression and diffusional ammonia permeability (measured utilizing ammonia analogues) of liver inner mitochondrial membranes were downregulated. NMR studies using 15N-labeled ammonia indicated that basal and glucagon-induced ureagenesis from ammonia were significantly reduced in hepatocytes from LPS-treated rats. Our data suggest that hepatocyte mtAQP8-mediated ammonia removal via ureagenesis is impaired by LPS, a mechanism potentially relevant to the molecular pathogenesis of defective hepatic ammonia detoxification in sepsis. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  12. Lipopolysaccharides of the cyanobacterium Microcystis aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Raziuddin, S.; Siegelman, H.W.; Tornabene, T.G.

    1983-01-01

    Lipopolysaccharides (LPS) of two isolates of Microcystis aeruginosa were extracted with phenol/water and purified. Cesium chloride gradient ultracentrifugation of these preparations yielded only one fraction. The LPS contained significant amounts of 3-deoxy-D-manno-octulosonic acid, glucose, 3-deoxy sugars, glucosamine, fatty acids, fatty acid esters, hexoses, and phosphate. Heptose, a characteristic sugar component of the polysaccharide moiety of LPS of most gram-negative bacteria was absent. Lipopolysaccharides and lipid A hydrolysate of LPS preparations were active in mouse lethality and Limulus lysate gelation. The lipid A moiety was slightly less active in toxicity and Limulus lysate gelation assay than the intact LPS. The LPS and lipid A moiety of the two isolates of M. aeruginosa were less active in toxicity in mice and Limulus test than LPS of Salmonella abortus equi. 37 references, 1 figure, 3 tables.

  13. Lipopolysaccharide-stimulated Leukocytes Contribute to Platelet Aggregative Dysfunction, Which is Attenuated by Catalase in Rats

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    Huei-Ping Dong

    2010-11-01

    Full Text Available Endotoxemia causes several hematological dysfunctions, including platelet degranulation or disseminated intravascular coagulation, which lead to thrombotic and hemorrhagic events. Here, we tested the hypothesis that bacterial lipopolysaccharide (LPS-stimulated leukocytes contribute to platelet aggregative dysfunction, and this function is attenuated by antioxidants. Plateletrich plasma (PRP was prepared from whole blood of normal and endotoxemic rats. The ability of platelet aggregation was measured by an aggregometer. LPS (50–100 μg/mL was incubated with PRP, whole blood and PRP with polymorphonuclear leukocytes (PMNs for 30 minutes, 60 minutes and 90 minutes, and platelet aggregation was detected. LPS-induced platelet aggregative dysfunction was undetectable in intact PRP which was isolated from normal whole blood, whereas it was detected in PRP isolated from endotoxemic rats and LPS-treated whole blood. Moreover, the effect of LPS-induced platelet aggregative dysfunction on intact PRP was observed when the PMNs were added. LPS-induced platelet aggregative dysfunction was significantly attenuated by catalase alone and in combination with NG-nitro-L-arginine methyl ester, but not by NG-nitro-L-arginine methyl ester alone. These results indicate that LPS-stimulated PMNs modulate platelet aggregation during LPS treatment and the effects are reversed by antioxidants. PMNs serve as an approach to understand LPS-induced platelet aggregative dysfunction during endotoxemia. During this process, the generation of reactive oxygen species, hydrogen peroxide especially, from LPS-stimulated PMNs could be an important potential factor in LPS-induced platelet aggregative dysfunction. Catalase contributes to the prevention of platelet dysfunction during LPS-induced sepsis.

  14. Involvement of mitogen-activated protein kinases and NFκB in LPS-induced CD40 expression on human monocytic cells

    International Nuclear Information System (INIS)

    Wu Weidong; Alexis, Neil E.; Chen Xian; Bromberg, Philip A.; Peden, David B.

    2008-01-01

    CD40 is a costimulatory molecule linking innate and adaptive immune responses to bacterial stimuli, as well as a critical regulator of functions of other costimulatory molecules. The mechanisms regulating lipopolysaccharide (LPS)-induced CD40 expression have not been adequately characterized in human monocytic cells. In this study we used a human monocytic cell line, THP-1, to investigate the possible mechanisms of CD40 expression following LPS exposure. Exposure to LPS resulted in a dose- and time-dependent increase in CD40 expression. Further studies using immunoblotting and pharmacological inhibitors revealed that mitogen-activated protein kinases (MAPKs) and NFκB were activated by LPS exposure and involved in LPS-induced CD40 expression. Activation of MAPKs was not responsible for LPS-induced NFκB activation. TLR4 was expressed on THP-1 cells and pretreatment of cells with a Toll-like receptor 4 (TLR4) neutralizing antibody (HTA125) significantly blunted LPS-induced MAPK and NFκB activation and ensuing CD40 expression. Additional studies with murine macrophages expressing wild type and mutated TLR4 showed that TLR4 was implicated in LPS-induced ERK and NFκB activation, and CD40 expression. Moreover, blockage of MAPK and NFκB activation inhibited LPS-induced TLR4 expression. In summary, LPS-induced CD40 expression in monocytic cells involves MAPKs and NFκB

  15. Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor

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    Elias Leiva-Salcedo

    2011-01-01

    Full Text Available The purinergic P2X7 receptor (P2X7R plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance.

  16. Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor

    Science.gov (United States)

    Leiva-Salcedo, Elias; Coddou, Claudio; Rodríguez, Felipe E.; Penna, Antonello; Lopez, Ximena; Neira, Tanya; Fernández, Ricardo; Imarai, Mónica; Rios, Miguel; Escobar, Jorge; Montoya, Margarita; Huidobro-Toro, J. Pablo; Escobar, Alejandro; Acuña-Castillo, Claudio

    2011-01-01

    The purinergic P2X7 receptor (P2X7R) plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS) is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance. PMID:21941410

  17. Lipopolysaccharide triggers nuclear import of Lpcat1 to regulate inducible gene expression in lung epithelia.

    Science.gov (United States)

    Ellis, Bryon; Kaercher, Leah; Snavely, Courtney; Zhao, Yutong; Zou, Chunbin

    2012-07-26

    To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene transcription. Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation. Lpcat1 translocates into the nucleus from the cytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli, two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overexpressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment. These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.

  18. Attenuation of Neuroinflammatory Responses in Lipopolysaccharide ...

    African Journals Online (AJOL)

    Chenopodiaceae) extract on neuroinflammatory responses induced by lipopolysaccharide (LPS) in BV-2 microglial cells and its antioxidant effects. Methods: Biochemical studies carried out include 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium ...

  19. Inhibition of lipopolysaccharide-induced neuroinflammatory events ...

    African Journals Online (AJOL)

    tetrazolium bromide (MTT) assay. Lipopolysaccharide (LPS) is used to activate BV-2 microglia. Nitric oxide (NO) levels were measured using Griess assay. Inducible NO synthase (iNOS) expressional levels were measured by Western blot analysis.

  20. Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment.

    Science.gov (United States)

    Vasconcelos, Andrea R; Yshii, Lidia M; Viel, Tania A; Buck, Hudson S; Mattson, Mark P; Scavone, Cristoforo; Kawamoto, Elisa M

    2014-05-06

    Systemic bacterial infections often result in enduring cognitive impairment and are a risk factor for dementia. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that intermittent fasting (IF) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of IF on the cognitive sequelae of systemic and brain inflammation is unknown. Rats on IF for 30 days received 1 mg/kg of lipopolysaccharide (LPS) or saline intravenously. Half of the rats were subjected to behavioral tests and the other half were euthanized two hours after LPS administration and the hippocampus was dissected and frozen for analyses. Here, we report that IF ameliorates cognitive deficits in a rat model of sepsis by a mechanism involving NF-κB activation, suppression of the expression of pro-inflammatory cytokines, and enhancement of neurotrophic support. Treatment of rats with LPS resulted in deficits in cognitive performance in the Barnes maze and inhibitory avoidance tests, without changing locomotor activity, that were ameliorated in rats that had been maintained on the IF diet. IF also resulted in reduced levels of mRNAs encoding the LPS receptor TLR4 and inducible nitric oxide synthase (iNOS) in the hippocampus. Moreover, IF prevented LPS-induced elevation of IL-1α, IL-1β and TNF-α levels, and prevented the LPS-induced reduction of BDNF levels in the hippocampus. IF also significantly attenuated LPS-induced elevations of serum IL-1β, IFN-γ, RANTES, TNF-α and IL-6 levels. Taken together, our results suggest that IF induces adaptive responses in the brain and periphery that can suppress inflammation and preserve cognitive function in an animal model of systemic bacterial infection.

  1. A presumed antagonistic LPS identifies distinct functional organization of TLR4 in mouse microglia.

    Science.gov (United States)

    Döring, Christin; Regen, Tommy; Gertig, Ulla; van Rossum, Denise; Winkler, Anne; Saiepour, Nasrin; Brück, Wolfgang; Hanisch, Uwe-Karsten; Janova, Hana

    2017-07-01

    Microglia as principle innate immune cells of the central nervous system (CNS) are the first line of defense against invading pathogens. They are capable of sensing infections through diverse receptors, such as Toll-like receptor 4 (TLR4). This receptor is best known for its ability to recognize bacterial lipopolysaccharide (LPS), a causative agent of gram-negative sepsis and septic shock. A putative, naturally occurring antagonist of TLR4 derives from the photosynthetic bacterium Rhodobacter sphaeroides. However, the antagonistic potential of R. sphaeroides LPS (Rs-LPS) is no universal feature, since several studies suggested agonistic rather than antagonistic actions of this molecule depending on the investigated mammalian species. Here we show the agonistic versus antagonistic potential of Rs-LPS in primary mouse microglia. We demonstrate that Rs-LPS efficiently induces the release of cytokines and chemokines, which depends on TLR4, MyD88, and TRIF, but not CD14. Furthermore, Rs-LPS is able to regulate the phagocytic capacity of microglia as agonist, while it antagonizes Re-LPS-induced MHC I expression. Finally, to our knowledge, we are the first to provide in vivo evidence for an agonistic potential of Rs-LPS, as it efficiently triggers the recruitment of peripheral immune cells to the endotoxin-challenged CNS. Together, our results argue for a versatile and complex organization of the microglial TLR4 system, which specifically translates exogenous signals into cellular functions. Importantly, as demonstrated here for microglia, the antagonistic potential of Rs-LPS needs to be considered with caution, as reactions to Rs-LPS not only differ by cell type, but even by function within one cell type. © 2017 Wiley Periodicals, Inc.

  2. NAC attenuates LPS-induced toxicity in aspirin-sensitized mouse macrophages via suppression of oxidative stress and mitochondrial dysfunction.

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    Haider Raza

    Full Text Available Bacterial endotoxin lipopolysaccharide (LPS induces the production of inflammatory cytokines and reactive oxygen species (ROS under in vivo and in vitro conditions. Acetylsalicylic acid (ASA, aspirin is a commonly used anti-inflammatory drug. Our aim was to study the effects of N-acetyl cysteine (NAC, an antioxidant precursor of GSH synthesis, on aspirin-sensitized macrophages treated with LPS. We investigated the effects of LPS alone and in conjunction with a sub-toxic concentration of ASA, on metabolic and oxidative stress, apoptosis, and mitochondrial function using J774.2 mouse macrophage cell line. Protection from LPS-induced toxicity by NAC was also studied. LPS alone markedly induced ROS production and oxidative stress in macrophage cells. When ASA was added to LPS-treated macrophages, the increase in oxidative stress was significantly higher than that with LPS alone. Similarly, alteration in glutathione-dependent redox metabolism was also observed in macrophages after treatment with LPS and ASA. The combination of LPS and ASA selectively altered the CYP 3A4, CYP 2E1 and CYP 1A1 catalytic activities. Mitochondrial respiratory complexes and ATP production were also inhibited by LPS-ASA treatment. Furthermore a higher apoptotic cell death was also observed in LPS-ASA treated macrophages. NAC pre-treatment showed protection against oxidative stress induced apoptosis and mitochondrial dysfunction. These effects are presumed, at least in part, to be associated with alterations in NF-κB/Nrf-2 mediated cell signaling. These results suggest that macrophages are more sensitive to LPS when challenged with ASA and that NAC pre-treatment protects the macrophages from these deleterious effects.

  3. Lipopolysaccharide hyporesponsiveness: protective or damaging response to the brain?

    Science.gov (United States)

    Pardon, Marie Christine

    2015-01-01

    Lipopolysaccharide (LPS) endotoxins are widely used as experimental models of systemic bacterial infection and trigger robust inflammation by potently activating toll-like receptors 4 (TLR4) expressed on innate immune cells. Their ability to trigger robust neuroinflammation despite poor brain penetration can prove useful for the understanding of how inflammation induced by viral infections contributes to the pathogenesis of neurodegenerative diseases. A single LPS challenge often result in a blunted inflammatory response to subsequent stimulation by LPS and other TLR ligands, but the extent to which endotoxin tolerance occur in the brain requires further clarification. LPS is also thought to render the brain transiently resistant to subsequent brain injuries by attenuating the concomitant pro-inflammatory response. While LPS hyporesponsiveness and preconditioning are classically seen as protective mechanisms limiting the toxic effects of sustained inflammation, recent research casts doubt as to whether they have beneficial or detrimental roles on the brain and in neurodegenerative disease. These observations suggest that spatio-temporal aspects of the immune responses to LPS and the disease status are determinant factors. Endotoxin tolerance may lead to a late pro-inflammatory response with potential harmful consequences. And while reduced TLR4 signaling reduces the risk of neurodegenerative diseases, up-regulation of anti-inflammatory cytokines associated with LPS hyporesponsiveness can have deleterious consequences to the brain by inhibiting the protective phenotype of microglia, aggravating the progression of some neurodegenerative conditions such as Alzheimer's disease. Beneficial effects of LPS preconditioning, however appear to require a stimulation of anti-inflammatory mediators rather than an attenuation of the pro-inflammatory response.

  4. Lipopolysaccharide promotes lipid accumulation in human adventitial fibroblasts via TLR4-NF-κB pathway

    Directory of Open Access Journals (Sweden)

    Wang Jun

    2012-10-01

    Full Text Available Abstract Background Atherosclerosis is a chronic degenerative disease of the arteries and is thought to be one of the most common causes of death globally. In recent years, the functions of adventitial fibroblasts in the development of atherosclerosis and tissue repair have gained increased interests. LPS can increase the morbidity and mortality of atherosclerosis-associated cardiovascular disease. Although LPS increases neointimal via TLR4 activation has been reported, how LPS augments atherogenesis through acting on adventitial fibroblasts is still unknown. Here we explored lipid deposition within adventitial fibroblasts mediated by lipopolysaccharide (LPS to imitate inflammatory conditions. Results In our study, LPS enhanced lipid deposition by the up-regulated expression of adipose differentiation-related protein (ADRP as the silencing of ADRP abrogated lipid deposition in LPS-activated adventitial fibroblasts. In addition, pre-treatment with anti-Toll-like receptor 4 (TLR4 antibody diminished the LPS-induced lipid deposition and ADRP expression. Moreover, LPS induced translocation of nuclear factor-κB (NF-κB, which could markedly up-regulate lipid deposition as pre-treatment with the NF-κB inhibitor, PDTC, significantly reduced lipid droplets. In addition, the lowering lipid accumulation was accompanied with the decreased ADRP expression. Furthermore, LPS-induced adventitial fibroblasts secreted more monocyte chemoattractant protein (MCP-1, compared with transforming growth factor-β1 (TGF-β1. Conclusions Taken together, these results suggest that LPS promotes lipid accumulation via the up-regulation of ADRP expression through TLR4 activated downstream of NF-κB in adventitial fibroblasts. Increased levels of MCP-1 released from LPS-activated adventitial fibroblasts and lipid accumulation may accelerate monocytes recruitment and lipid-laden macrophage foam cells formation. Here, our study provides a new explanation as to how bacterial

  5. Attenuation of Neuroinflammatory Responses in Lipopolysaccharide ...

    African Journals Online (AJOL)

    HP

    neuroinflammatory responses induced by lipopolysaccharide (LPS) in BV-2 microglial cells and its antioxidant effects. Methods: Biochemical studies ... [2] and as an anti-aging agent in cosmeceuticals [4]. However, its pharmacological actions on ... in LPS-stimulated BV-2 microglia and explored the possible mechanism.

  6. Inhibition of Lipopolysaccharide-Stimulated Neuro- Inflammatory ...

    African Journals Online (AJOL)

    Purpose: To investigate the in vitro antioxidant and anti-neuroinflammatory effects of Tetragonia tetragonoides (Pall.) Kuntze extract (TKE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Methods: To evaluate the effects of TKE, LPS-stimulated BV microglia were used and the expression and production of ...

  7. Enteroendocrine L Cells Sense LPS after Gut Barrier Injury to Enhance GLP-1 Secretion

    Directory of Open Access Journals (Sweden)

    Lorène J. Lebrun

    2017-10-01

    Full Text Available Summary: Glucagon-like peptide 1 (GLP-1 is a hormone released from enteroendocrine L cells. Although first described as a glucoregulatory incretin hormone, GLP-1 also suppresses inflammation and promotes mucosal integrity. Here, we demonstrate that plasma GLP-1 levels are rapidly increased by lipopolysaccharide (LPS administration in mice via a Toll-like receptor 4 (TLR4-dependent mechanism. Experimental manipulation of gut barrier integrity after dextran sodium sulfate treatment, or via ischemia/reperfusion experiments in mice, triggered a rapid rise in circulating GLP-1. This phenomenon was detected prior to measurable changes in inflammatory status and plasma cytokine and LPS levels. In human subjects, LPS administration also induced GLP-1 secretion. Furthermore, GLP-1 levels were rapidly increased following the induction of ischemia in the human intestine. These findings expand traditional concepts of enteroendocrine L cell biology to encompass the sensing of inflammatory stimuli and compromised mucosal integrity, linking glucagon-like peptide secretion to gut inflammation. : Lebrun et al. demonstrate that enteroendocrine L cells sense lipopolysaccharides (pro-inflammatory bacterial compounds after gut injury and respond by secreting glucagon-like peptide 1. These findings expand concepts of L cell function to include roles as both a nutrient and pathogen sensor, linking glucagon-like peptide secretion to gut inflammation. Keywords: glucagon-like peptide 1, lipopolysaccharides, enteroendocrine cells, TLR4, gut injury, intestinal ischemia, inflammation

  8. Morphology and LPS content for the estimation of marine bacterioplankton biomass in the Ionian Sea

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    Rosabruna La Ferla

    2004-03-01

    Full Text Available The abundance, morphotypes and biomass of the bacterial assemblages were investigated in the Ionian Sea by using two different methods: the epifluorescent microscopy technique for enumerating and sizing bacterial cells, and the determination of bacterial lipopolysaccharides (LPS. Five bacterial morphotypes were distinguished: cocci, rods, coccobacilli, vibrios and spirillae. The proportions of cocci were higher than those of other morphotypes at every depth, ranging from 39% to 73%. Both rod-shaped bacteria and coccobacilli were homogenously distributed in the water column, while the proportions of vibrios were rather variable. Spirillae occurred only in surface samples and disappeared below 100 m. The two methodologies were compared: LPS concentrations showed a highly significant correlation with the bacterial numbers (P< 0.01; n= 88; r= 0.68, but not with biovolumes, and different ratios between LPS concentrations and bacterial volumes were recorded for the photic and aphotic zones (3.11 ± 1.35 and 0.96 ± 0.37 ng LPS per µm3 respectively. LPS-derived cell carbon content on average was 23 fg C cell-1, similar to the C amount derived by mean cell biovolume (19 fg C cell-1 and the biomass from two highly correlated methods (P< 0.01; n= 95; r= 0.59. Our results confirm that the widely used factor of 20 fg C cell-1 (Lee and Furhman, 1987 should be plausible for studying the biomass of the natural microbial populations in the study area. Nevertheless, the wide variability of the cell size classes, also along the whole water columns, questions the applicability of a constant conversion factor for all the marine ecosystems. Consequently, locally derived biomass estimates of bacteria are essential in order to obtain an accurate evaluation of the bacterial role in biogeochemical cycles.

  9. Relationship between chemical composition and biological function of Pseudomonas aeruginosa lipopolysaccharide: effect on human neutrophil chemotaxis and oxidative burst

    DEFF Research Database (Denmark)

    Kharazmi, A; Fomsgaard, A; Conrad, R S

    1991-01-01

    There are conflicting data on the effect of bacterial lipopolysaccharides (LPS) on the function of human neutrophils. The present study was designed to examine the relationship between chemical composition and the modulatory effect of LPS on human neutrophil function. LPS was extracted from five...... no effect on neutrophil chemotaxis and a slight effect on chemiluminescence. The major differences in chemical composition of the LPS from these two strains are in the rhamnose and heptose content of the O side chain and in the alanine content of the core region. These data indicate that chemical...... strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients by the hot phenol-water method. Chemical characterization included neutral sugars, amino components, and fatty acids. Neutrophils isolated from peripheral blood of healthy individuals were preincubated with different concentrations...

  10. Allicin Protects against Lipopolysaccharide-Induced Acute Lung ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of allicin, an active component of garlic, on lipopolysaccharide (LPS)- induced acute lung injury. Methods: Wistar rats were subjected to LPS intravenous injection with or without allicin treatment to induce acute lung injury (ALI) model. Also, A549 cells were stimulated with LPS in the ...

  11. Meningitis caused by a lipopolysaccharide deficient Neisseria meningitidis

    NARCIS (Netherlands)

    Piet, Jurgen R; Zariri, Afshin; Fransen, Floris; Schipper, Kim; van der Ley, Peter; van de Beek, Diederik; van der Ende, Arie; van Putten, Jos

    2014-01-01

    OBJECTIVE: Lipopolysaccharide (LPS) is a major component of the Neisseria meningitidis outer membrane. Here we report a patient with meningococcal meningitis of which the causative isolate lacked LPS. Thus far, no naturally occurring LPS-deficient meningococcal isolate has been known to cause

  12. Yohimbine enhances protection of berberine against LPS-induced mouse lethality through multiple mechanisms.

    Directory of Open Access Journals (Sweden)

    Hui Li

    Full Text Available Sepsis remains a major cause of mortality in intensive care units, better therapies are urgently needed. Gram-negative bacterial lipopolysaccharide (LPS is an important trigger of sepsis. We have demonstrated that berberine (Ber protects against lethality induced by LPS, which is enhanced by yohimbine (Y pretreatment, and Ber combined with Y also improves survival in septic mice. However, the precise mechanisms by which Y enhances protection of Ber against LPS-induced lethality remain unclear. The present study confirmed that simultaneously administered Y also enhanced protection of Ber against LPS-induced lethality. Ber or/and Y attenuated liver injury, but not renal injury in LPS-challenged mice. Ber or/and Y all inhibited LPS-stimulated IκBα, JNK and ERK phosphorylation, NF-κB activation as well as TNF-α production. Ber also increased IL-10 production in LPS-challenged mice, which was enhanced by Y. Furthermore, Ber or/and Y all suppressed LPS-induced IRF3, TyK2 and STAT1 phosphorylation, as well as IFN-β and IP-10 mRNA expression in spleen of mice at 1 h after LPS challenge. Especially, Y enhanced the inhibitory effect of Ber on LPS-induced IP-10 mRNA expression. In vitro experiments further demonstrated that Y significantly enhanced the inhibitory effect of Ber on TNF-α production in LPS-treated peritoneal macrophages, Ber combined with Y promoted LPS-induced IL-10 production and LPS-stimulated IκBα, JNK, ERK and IRF3 phosphorylation and NF-κB activation were also suppressed by Ber or/and Y pretreatment in peritoneal macrophages. Taken together, these results demonstrate that Y enhances the protection of Ber against LPS-induced lethality in mice via attenuating liver injury, upregulating IL-10 production and suppressing IκBα, JNK, ERK and IRF3 phosphorylation. Ber combined with Y may be an effective immunomodulator agent for the prevention of sepsis.

  13. Pleurotus eryngii Ameliorates Lipopolysaccharide-Induced Lung Inflammation in Mice

    Directory of Open Access Journals (Sweden)

    Junya Kawai

    2014-01-01

    Full Text Available Pleurotus eryngii (P. eryngii is consumed as a fresh cultivated mushroom worldwide and demonstrated to have multiple beneficial effects. We investigated the anti-inflammatory effect of P. eryngii in mice with acute lung injury (ALI. Intranasal instillation of lipopolysaccharide (LPS (10 μg/site/mouse induced marked lung inflammation (increase in the number of inflammatory cells, protein leakage, and production of nitric oxide in bronchoalveolar lavage fluid as well as histopathological damage in the lung, 6 h after treatment. Mice administered heat-treated P. eryngii (0.3–1 g/kg, p.o. (HTPE 1 h before LPS challenge showed decreased pulmonary inflammation and ameliorated histopathological damage. These results suggest that HTPE has anti-inflammatory effects against ALI. Thus, P. eryngii itself may also have anti-inflammatory effects and could be a beneficial food for the prevention of ALI induced by bacterial infection.

  14. An MD2-derived peptide promotes LPS aggregation, facilitates its internalization in THP-1 cells, and inhibits LPS-induced pro-inflammatory responses.

    Science.gov (United States)

    Tandon, Anshika; Harioudh, Munesh Kumar; Ishrat, Nayab; Tripathi, Amit Kumar; Srivastava, Saurabh; Ghosh, Jimut Kanti

    2018-01-08

    MD2, a 160-residue accessory glycoprotein, is responsible for the recognition and binding of Gram-negative bacterial membrane component, lipopolysaccharide (LPS). Internalization of pathogen inside the mononuclear phagocytes has also been attributed to MD2 which leads to the clearance of pathogens from the host. However, not much is known about the segments in MD2 that are responsible for LPS interaction or internalization of pathogen inside the defense cells. A 16-residue stretch (MD54) from MD2 protein has been identified that possesses a short heptad repeat sequence and four cationic residues enabling it to participate in both hydrophobic and electrostatic interactions with LPS. An MD54 analog of the same size was also designed in which a leucine residue at a heptadic position was replaced with an alanine residue. MD54 but not its analog, MMD54 induced aggregation of LPS and aided in its internalization within THP-1 monocytes. Furthermore, MD54 inhibited LPS-induced nuclear translocation of NF-κB in PMA-treated THP-1 and TLR4/MD2/CD14-transfected HEK-293T cells and the production of pro-inflammatory cytokines. In addition, in in vivo experiments, MD54 showed marked protection and survival of mice against LPS-induced inflammation and death. Overall, we have identified a short peptide with heptad repeat sequence from MD2 that can cause aggregation of LPS and abet in its internalization within THP-1 cells, resulting in attenuation of LPS-induced pro-inflammatory responses in vitro and in vivo.

  15. Analysis of migration rate and chemotaxis of human adipose-derived mesenchymal stem cells in response to LPS and LTA in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Herzmann, Nicole; Salamon, Achim [Department of Cell Biology, University Medicine Rostock, Schillingallee 69, D-18057 Rostock (Germany); Fiedler, Tomas [Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Schillingallee 70, D-18057 Rostock (Germany); Peters, Kirsten, E-mail: kirsten.peters@med.uni-rostock.de [Department of Cell Biology, University Medicine Rostock, Schillingallee 69, D-18057 Rostock (Germany)

    2016-03-15

    Mesenchymal stem cells (MSC) are able to stimulate the regeneration of injured tissue. Since bacterial infections are common complications in wound healing, bacterial pathogens and their components come into direct contact with MSC. The interaction with bacterial structures influences the proliferation, differentiation and migratory activity of the MSC, which might be of relevance during regeneration. Studies on MSC migration in response to bacterial components have shown different results depending on the cell type. Here, we analyzed the migration rate and chemotaxis of human adipose-derived MSC (adMSC) in response to the basic cell-wall components lipopolysaccharide (LPS) of Gram-negative bacteria and lipoteichoic acid (LTA) of Gram-positive bacteria in vitro. To this end, we used transwell and scratch assays, as well as a specific chemotaxis assay combined with live-cell imaging. We found no significant influence of LPS or LTA on the migration rate of adMSC in transwell or scratch assays. Furthermore, in the µ-slide chemotaxis assay, the stimulation with LPS did not exert any chemotactic effect on adMSC. - Highlights: • LPS increased the release of IL-6 and IL-8 in adMSC significantly. • The migration rate of adMSC was not influenced by LPS or LTA. • LPS or LTA did not exert a chemotactic effect on adMSC.

  16. Analysis of migration rate and chemotaxis of human adipose-derived mesenchymal stem cells in response to LPS and LTA in vitro

    International Nuclear Information System (INIS)

    Herzmann, Nicole; Salamon, Achim; Fiedler, Tomas; Peters, Kirsten

    2016-01-01

    Mesenchymal stem cells (MSC) are able to stimulate the regeneration of injured tissue. Since bacterial infections are common complications in wound healing, bacterial pathogens and their components come into direct contact with MSC. The interaction with bacterial structures influences the proliferation, differentiation and migratory activity of the MSC, which might be of relevance during regeneration. Studies on MSC migration in response to bacterial components have shown different results depending on the cell type. Here, we analyzed the migration rate and chemotaxis of human adipose-derived MSC (adMSC) in response to the basic cell-wall components lipopolysaccharide (LPS) of Gram-negative bacteria and lipoteichoic acid (LTA) of Gram-positive bacteria in vitro. To this end, we used transwell and scratch assays, as well as a specific chemotaxis assay combined with live-cell imaging. We found no significant influence of LPS or LTA on the migration rate of adMSC in transwell or scratch assays. Furthermore, in the µ-slide chemotaxis assay, the stimulation with LPS did not exert any chemotactic effect on adMSC. - Highlights: • LPS increased the release of IL-6 and IL-8 in adMSC significantly. • The migration rate of adMSC was not influenced by LPS or LTA. • LPS or LTA did not exert a chemotactic effect on adMSC.

  17. Muramyl Dipeptide Enhances Lipopolysaccharide-Induced Osteoclast Formation and Bone Resorption through Increased RANKL Expression in Stromal Cells

    Directory of Open Access Journals (Sweden)

    Masahiko Ishida

    2015-01-01

    Full Text Available Lipopolysaccharide (LPS is bacterial cell wall component capable of inducing osteoclast formation and pathological bone resorption. Muramyl dipeptide (MDP, the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is ubiquitously expressed by bacterium. In this study, we investigated the effect of MDP in LPS-induced osteoclast formation and bone resorption. LPS was administered with or without MDP into the supracalvariae of mice. The number of osteoclasts, the level of mRNA for cathepsin K and tartrate-resistant acid phosphatase (TRAP, the ratio of the bone destruction area, the level of tartrate-resistant acid phosphatase form 5b (TRACP 5b, and C-terminal telopeptides fragments of type I collagen as a marker of bone resorption in mice administrated both LPS and MDP were higher than those in mice administrated LPS or MDP alone. On the other hand, MDP had no effect on osteoclastogenesis in parathyroid hormone administrated mice. MDP enhanced LPS-induced receptor activator of NF-κB ligand (RANKL expression and Toll-like receptor 4 (TLR4 expression in vivo and in stromal cells in vitro. MDP also enhanced LPS-induced mitogen-activated protein kinase (MAPK signaling, including ERK, p38, and JNK, in stromal cells. These results suggest that MDP might play an important role in pathological bone resorption in bacterial infection diseases.

  18. Sickness behaviour after lipopolysaccharide treatment in ghrelin deficient mice.

    Science.gov (United States)

    Szentirmai, Éva; Krueger, James M

    2014-02-01

    Ghrelin is an orexigenic hormone produced mainly by the gastrointestinal system and the brain. Much evidence also indicates a role for ghrelin in sleep and thermoregulation. Further, ghrelin was recently implicated in immune system modulation. Administration of bacterial lipopolysaccharide (LPS) induces fever, anorexia, and increased non-rapid-eye movement sleep (NREMS) and these actions are mediated primarily by proinflammatory cytokines. Ghrelin reduces LPS-induced fever, suppresses circulating levels of proinflammatory cytokines and reduces the severity and mortality of various models of experimental endotoxemia. In the present study, we determined the role of intact ghrelin signaling in LPS-induced sleep, feeding, and thermoregulatory responses in mice. Sleep-wake activity was determined after intraperitoneal, dark onset administration of 0.4, 2 and 10 μg LPS in preproghrelin knockout (KO) and wild-type (WT) mice. In addition, body temperature, motor activity and changes in 24-h food intake and body weight were measured. LPS induced dose-dependent increases in NREMS, and suppressed rapid-eye movement sleep, electroencephalographic slow-wave activity, motor activity, food intake and body weight in both Ppg KO and WT mice. Body temperature changes showed a biphasic pattern with a decrease during the dark period followed by an increase in the light phase. The effects of the low and middle doses of LPS were indistinguishable between the two genotypes. Administration of 10 μg LPS, however, induced significantly larger changes in NREMS and wakefulness amounts, body temperature, food intake and body weight in the Ppg KO mice. These findings support a role for ghrelin as an endogenous modulator of inflammatory responses and a central component of arousal and feeding circuits. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. The role of horizontal transfer in the evolution of a highly variable lipopolysaccharide biosynthesis locus in xanthomonads that infect rice, citrus and crucifers

    Directory of Open Access Journals (Sweden)

    Bogdanove Adam J

    2007-12-01

    Full Text Available Abstract Background Lipopolysaccharide (LPS is a pathogen associated molecular pattern (PAMP of animal and plant pathogenic bacteria. Variation at the interstrain level is common in LPS biosynthetic gene clusters of animal pathogenic bacteria. This variation has been proposed to play a role in evading the host immune system. Even though LPS is a modulator of plant defense responses, reports of interstrain variation in LPS gene clusters of plant pathogenic bacteria are rare. Results In this study we report the complete sequence of a variant 19.9 kb LPS locus present in the BXO8 strain of Xanthomonas oryzae pv. oryzae (Xoo, the bacterial blight pathogen of rice. This region is completely different in size, number and organization of genes from the LPS locus present in most other strains of Xoo from India and Asia. Surprisingly, except for one ORF, all the other ORFs at the BXO8 LPS locus are orthologous to the genes present at this locus in a sequenced strain of X. axonopodis pv. citri (Xac; a pathogen of citrus plants. One end of the BXO8 LPS gene cluster, comprised of ten genes, is also present in the related rice pathogen, X. oryzae pv. oryzicola (Xoc. In Xoc, the remainder of the LPS gene cluster, consisting of seven genes, is novel and unrelated to LPS gene clusters of any of the sequenced xanthomonads. We also report substantial interstrain variation suggestive of very recent horizontal gene transfer (HGT at the LPS biosynthetic locus of Xanthomonas campestris pv. campestris (Xcc, the black rot pathogen of crucifers. Conclusion Our analyses indicate that HGT has altered the LPS locus during the evolution of Xanthomonas oryzae pathovars and suggest that the ancestor of all Xanthomonas oryzae pathovars had an Xac type of LPS gene cluster. Our finding of interstrain variation in two major xanthomonad pathogens infecting different hosts suggests that the LPS locus in plant pathogenic bacteria, as in animal pathogens, is under intense

  20. Hypoacylated LPS from Foodborne Pathogen Campylobacter jejuni Induces Moderate TLR4-Mediated Inflammatory Response in Murine Macrophages

    Directory of Open Access Journals (Sweden)

    Kirill V. Korneev

    2018-02-01

    Full Text Available Toll-like receptor 4 (TLR4 initiates immune response against Gram-negative bacteria upon specific recognition of lipid A moiety of lipopolysaccharide (LPS, the major component of their cell wall. Some natural differences between LPS variants in their ability to interact with TLR4 may lead to either insufficient activation that may not prevent bacterial growth, or excessive activation which may lead to septic shock. In this study we evaluated the biological activity of LPS isolated from pathogenic strain of Campylobacter jejuni, the most widespread bacterial cause of foodborne diarrhea in humans. With the help of hydrophobic chromatography and MALDI-TOF mass spectrometry we showed that LPS from a C. jejuni strain O2A consists of both hexaacyl and tetraacyl forms. Since such hypoacylation can result in a reduced immune response in humans, we assessed the activity of LPS from C. jejuni in mouse macrophages by measuring its capacity to activate TLR4-mediated proinflammatory cytokine and chemokine production, as well as NFκB-dependent reporter gene transcription. Our data support the hypothesis that LPS acylation correlates with its bioactivity.

  1. Hypoacylated LPS from Foodborne Pathogen Campylobacter jejuni Induces Moderate TLR4-Mediated Inflammatory Response in Murine Macrophages.

    Science.gov (United States)

    Korneev, Kirill V; Kondakova, Anna N; Sviriaeva, Ekaterina N; Mitkin, Nikita A; Palmigiano, Angelo; Kruglov, Andrey A; Telegin, Georgy B; Drutskaya, Marina S; Sturiale, Luisa; Garozzo, Domenico; Nedospasov, Sergei A; Knirel, Yuriy A; Kuprash, Dmitry V

    2018-01-01

    Toll-like receptor 4 (TLR4) initiates immune response against Gram-negative bacteria upon specific recognition of lipid A moiety of lipopolysaccharide (LPS), the major component of their cell wall. Some natural differences between LPS variants in their ability to interact with TLR4 may lead to either insufficient activation that may not prevent bacterial growth, or excessive activation which may lead to septic shock. In this study we evaluated the biological activity of LPS isolated from pathogenic strain of Campylobacter jejuni , the most widespread bacterial cause of foodborne diarrhea in humans. With the help of hydrophobic chromatography and MALDI-TOF mass spectrometry we showed that LPS from a C. jejuni strain O2A consists of both hexaacyl and tetraacyl forms. Since such hypoacylation can result in a reduced immune response in humans, we assessed the activity of LPS from C. jejuni in mouse macrophages by measuring its capacity to activate TLR4-mediated proinflammatory cytokine and chemokine production, as well as NFκB-dependent reporter gene transcription. Our data support the hypothesis that LPS acylation correlates with its bioactivity.

  2. Lipopolysaccharide Compromises Human Sperm Function by Reducing Intracellular cAMP.

    Science.gov (United States)

    Li, Zhongyuan; Zhang, Dahu; He, Yuanqiao; Ding, Zhiyong; Mao, Fei; Luo, Tao; Zhang, Xiaoping

    2016-02-01

    A worldwide decline in the quality of human semen is currently occurring. In mammals, sperm are produced from diploid stem-cell spermatogonia by spermatogenesis in testes and become mature in epididymis. Nevertheless, these biological processes can be affected by Gram-negative bacterial infection mediated by lipopolysaccharide (LPS), the major endotoxin of Gram-negative bacteria. It is well known that LPS can disturb spermatogenesis and affect sperm maturation and quality in vivo. However, the effect of LPS on the ejaculated mature sperm in vitro remains unclear. Thus, this study aimed to assess the in vitro toxicity of LPS on human sperm function and to elucidate the underlying mechanism. Human sperm were incubated with LPS (0.1-100 μg/ml) for 1-12 h in vitro and, subsequently, sperm viability, motility and capacitation, and the acrosome reaction were examined. LPS dose-dependently inhibited total and progressive motility and the ability to move through a viscous medium of the sperm but did not affect sperm viability, capacitation, and the acrosome reaction. To explore the underlying mechanism of LPS's actions, we examined the effects of LPS on the intracellular concentrations of cyclic adenosine monophosphate (cAMP) and calcium ([Ca(2+)]i) and protein-tyrosine phosphorylation of human sperm, which are key regulators of human sperm function. LPS decreased intracellular cAMP dose-dependently but had no effect on [Ca(2+)]i and protein-tyrosine phosphorylation of human sperm. These findings suggest that LPS inhibits human sperm motility by decreasing intracellular cAMP.

  3. The influence of phosphodiesterase inhibitor, rolipram, on hemodynamics in lipopolysaccharide-treated rats.

    Science.gov (United States)

    Dutta, P; Ryan, D E; Tabrizchi, R

    2001-03-01

    Administration of bacterial endotoxin (lipopolysaccharide, LPS) intravenously has been noted to produce a shock state, which is characterized by hypotension and multi-organ system failure. The aim of the present investigation was to (a) examine the influence of rolipram on hemodynamics, plasma levels of tumor necrosis factor-alpha (TNF-alpha) levels, and production of inducible nitric oxide synthase (iNOS) in the lungs, ex vivo, in LPS-treated rats, and (b) determine the cardiovascular effects of a selective alpha1-adrenoceptor agonist, methoxamine, in the absence or presence of rolipram in rats treated with LPS. Blood pressure, cardiac index, heart rate and arterial resistance were assessed in Long-Evans rats anesthetized with thiobutabarbital. Administration of LPS to animals resulted in a significant reduction in cardiac index over time. The administration of LPS to rats resulted in a substantial rise in the plasma levels of TNF-alpha. Furthermore, the injection of LPS resulted in a significant increase in the iNOS activity in the lungs. Pre-treatment with rolipram prevented the decline in cardiac index in animals that received LPS. Infusion of methoxamine into animals injected with rolipram and pre-treated with LPS did not result in significant changes in cardiac index. Pre-treatment with rolipram or dexamethasone in animals injected with LPS significantly prevented the rise in TNF-alpha when compared to the respective values in vehicle-treated animals. Our present observations support the view that the cardiac index can be maintained in animals treated with LPS independent of iNOS inhibition.

  4. Apoptosis of gut-associated lymphoid tissue in rainbow trout Oncorhynchus mykiss after incubation with Candida albicans and bacterial lipopolysaccharide.

    Science.gov (United States)

    Passantino, L; Ostillio, A; Cianciotta, A; Russo, C; Carrassi, M; Patruno, R; Dhaskali, L; Passantino, G F; Passantino, A

    2011-06-01

    Until now a few studies have been carried out on the gut lymphoid system in fish despite its protective role in the host. Here, we have evaluated the effects of Candida albicans (Ca) and lipopolysaccaride (LPS) on the pyloric and terminal segments of gut in the rainbow trout Oncorhynchus mykiss. In particular, data show that both Ca and LPS are able to cause apoptosis of intestinal lymphoid cells as detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) procedure. These findings suggest a further modality of gut response in fish to environmental antigens.

  5. Induction of bacterial lipoprotein tolerance is associated with suppression of toll-like receptor 2 expression.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    Tolerance to bacterial cell wall components including lipopolysaccharide (LPS) may represent an essential regulatory mechanism during bacterial infection. Two members of the Toll-like receptor (TLR) family, TLR2 and TLR4, recognize the specific pattern of bacterial cell wall components. TLR4 has been found to be responsible for LPS tolerance. However, the role of TLR2 in bacterial lipoprotein (BLP) tolerance and LPS tolerance is unclear. Pretreatment of human THP-1 monocytic cells with a synthetic bacterial lipopeptide induced tolerance to a second BLP challenge with diminished tumor necrosis factor-alpha and interleukin-6 production, termed BLP tolerance. Furthermore, BLP-tolerized THP-1 cells no longer responded to LPS stimulation, indicating a cross-tolerance to LPS. Induction of BLP tolerance was CD14-independent, as THP-1 cells that lack membrane-bound CD14 developed tolerance both in serum-free conditions and in the presence of a specific CD14 blocking monoclonal antibody (MEM-18). Pre-exposure of THP-1 cells to BLP suppressed mitogen-activated protein kinase phosphorylation and nuclear factor-kappaB activation in response to subsequent BLP and LPS stimulation, which is comparable with that found in LPS-tolerized cells, indicating that BLP tolerance and LPS tolerance may share similar intracellular pathways. However, BLP strongly enhanced TLR2 expression in non-tolerized THP-1 cells, whereas LPS stimulation had no effect. Furthermore, a specific TLR2 blocking monoclonal antibody (2392) attenuated BLP-induced, but not LPS-induced, tumor necrosis factor-alpha and interleukin-6 production, indicating BLP rather than LPS as a ligand for TLR2 engagement and activation. More importantly, pretreatment of THP-1 cells with BLP strongly inhibited TLR2 activation in response to subsequent BLP stimulation. In contrast, LPS tolerance did not prevent BLP-induced TLR2 overexpression. These results demonstrate that BLP tolerance develops through down-regulation of TLR2

  6. Lipopolysaccharide phase variation determines the complement-mediated serum susceptibility of Coxiella burnetii.

    OpenAIRE

    Vishwanath, S; Hackstadt, T

    1988-01-01

    Phase variation of Coxiella burnetii is due to variation of the lipopolysaccharide (LPS), a phenomenon analogous to smooth-to-rough LPS variation of gram-negative enteric bacteria. Virulent enterobacteria usually have a smooth LPS and resist serum killing, whereas avirulent rough LPS mutants are sensitive to complement-mediated serum killing. Like gram-negative enterobacteria, smooth LPS phase variants of C. burnetii are virulent, whereas the rough LPS variants are avirulent. We therefore stu...

  7. Reactive nitrogen intermediate production and tolerance variability in different mouse strains after in vivo treatment with lipopolysaccharide from Salmonella abortus equi.

    Science.gov (United States)

    Nahrevanian, Hossein; Salmasi, Jafar Gholizadeh; Farahmand, Mahin; Aghighi, Zohreh; Assmar, Mehdi; Abolhassani, Mohsen

    2005-06-01

    Lipopolysaccharide (LPS) stimulation in animal models generates a large number of immune factors including cytokines and mediators. It also acts as a potent inducer of macrophage reactive oxygen intermediates and reactive nitrogen intermediates (RNI). RNI as stable metabolites of nitric oxide (NO) are produced by cells stimulated with LPS and cytokines. In this study, LPS from Salmonella abortus equi was investigated as an inducer of RNI in untreated controls and test groups of white Naval Medical Research Institute (NMRI) mice. Animals were humanely killed at 30, 60, 120 and 180 min after LPS injection, and plasma RNI was measured by Griess microassay. In a further experiment, host tolerance against bacterial LPS was evaluated by sequential intravenous injection of LPS concentrations of 4, 1 and 0.5 mg/kg at 24 h intervals in NMRI and with the same schedule but via subcutaneous injection in Balb/c mice. Statistical analysis of RNI values using analysis of variance test indicated that in vivo LPS stimulation induced high levels of NO in murine hosts (pRNI levels at different times after administration revealed the largest amount of RNI at 180 min after inoculation. Analysis of the time course until maximum RNI induction indicated that NMRI mice had the longest delay, suggesting a difference in tolerance of NMRI and Balb/c mice to LPS stimulation dependent on LPS concentration, dose, and route of inoculation.

  8. Motif prediction to distinguish LPS-stimulated pro-inflammatory vs. antibacterial macrophage genes

    Science.gov (United States)

    2010-01-01

    Background Innate immunity is the first line of defence offered by host cells to infections. Macrophage cells involved in innate immunity are stimulated by lipopolysaccharide (LPS), found on bacterial cell surface, to express a complex array of gene products. Persistent LPS stimulation makes a macrophage tolerant to LPS with down regulation of inflammatory genes ("pro-inflammatory") while continually expressing genes to fight the bacterial infection ("antibacterial"). Interactions of transcription factors (TF) at their cognate TF binding sites (TFBS) on the expressed genes are important in transcriptional regulatory networks that control these pro-inflammatory and antibacterial expression paradigms involved in LPS stimulation. Results We used differential expression patterns in a public domain microarray data set from LPS-stimulated macrophages to identify 228 pro-inflammatory and 18 antibacterial genes. Employing three different motif search tools, we predicted respectively four and one statistically significant TF-TFBS interactions from the pro-inflammatory and antibacterial gene sets. The biological literature was utilized to identify target genes for the four pro-inflammatory profile TFs predicted from the three tools, and 18 of these target genes were observed to follow the pro-inflammatory expression pattern in the original microarray data. Conclusions Our analysis distinguished pro-inflammatory vs. antibacterial transcriptomic signatures that classified their respective gene expression patterns and the corresponding TF-TFBS interactions in LPS-stimulated macrophages. By doing so, this study has attempted to characterize the temporal differences in gene expression associated with LPS tolerance, a major immune phenomenon implicated in various pathological disorders. PMID:20858252

  9. TRPA1 channels mediate acute neurogenic inflammation and pain produced by bacterial endotoxins

    Science.gov (United States)

    Meseguer, Victor; Alpizar, Yeranddy A.; Luis, Enoch; Tajada, Sendoa; Denlinger, Bristol; Fajardo, Otto; Manenschijn, Jan-Albert; Fernández-Peña, Carlos; Talavera, Arturo; Kichko, Tatiana; Navia, Belén; Sánchez, Alicia; Señarís, Rosa; Reeh, Peter; Pérez-García, María Teresa; López-López, José Ramón; Voets, Thomas; Belmonte, Carlos; Talavera, Karel; Viana, Félix

    2014-01-01

    Gram-negative bacterial infections are accompanied by inflammation and somatic or visceral pain. These symptoms are generally attributed to sensitization of nociceptors by inflammatory mediators released by immune cells. Nociceptor sensitization during inflammation occurs through activation of the Toll-like receptor 4 (TLR4) signalling pathway by lipopolysaccharide (LPS), a toxic by-product of bacterial lysis. Here we show that LPS exerts fast, membrane delimited, excitatory actions via TRPA1, a transient receptor potential cation channel that is critical for transducing environmental irritant stimuli into nociceptor activity. Moreover, we find that pain and acute vascular reactions, including neurogenic inflammation (CGRP release) caused by LPS are primarily dependent on TRPA1 channel activation in nociceptive sensory neurons, and develop independently of TLR4 activation. The identification of TRPA1 as a molecular determinant of direct LPS effects on nociceptors offers new insights into the pathogenesis of pain and neurovascular responses during bacterial infections and opens novel avenues for their treatment.

  10. Lipopolysaccharide Adsorbed to the Bio-Corona of TiO2 Nanoparticles Powerfully Activates Selected Pro-inflammatory Transduction Pathways

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    Massimiliano G. Bianchi

    2017-08-01

    Full Text Available It is known that the adsorption of bioactive molecules provides engineered nanoparticles (NPs with novel biological activities. However, the biological effects of the adsorbed molecules may also be modified by the interaction with NP. Bacterial lipopolysaccharide (LPS, a powerful pro-inflammatory compound, is a common environmental contaminant and is present in several body compartments such as the gut. We recently observed that the co-incubation of LPS with TiO2 NPs markedly potentiates its pro-inflammatory effects on murine macrophages, suggesting that, when included in a NP bio-corona, LPS activity is enhanced. To distinguish the effects of adsorbed LPS from those of the free endotoxin, a pellet fraction, denominated P25/LPS, was isolated by centrifugation from a mixture of P25 TiO2 NP (128 µg/ml and LPS (10 ng/ml in the presence of fetal bovine serum. Western blot analysis of the pellet eluate indicated that the P25/LPS fraction contained, besides proteins, also LPS, pointing to the presence of LPS-doped NP. The effects of adsorbed or free LPS were then compared in Raw264.7 murine macrophages. RT-PCR was used to evaluate the induction of cytokine genes, whereas active, phosphorylated isoforms of proteins involved in signaling pathways were assessed with western blot. At a nominal LPS concentration of 40 pg/ml, P25/LPS induced the expression of both NF-κB and IRF3-dependent cytokines at levels comparable with those observed with free LPS (10 ng/ml, although with different time courses. Moreover, compared to free LPS, P25/LPS caused a more sustained phosphorylation of p38 MAPK and a more prolonged induction of STAT1-dependent genes. Cytochalasin B partially inhibited the induction of Tnfa by P25/LPS, but not by free LPS, and suppressed the induction of IRF3-dependent genes by either P25/LPS or free LPS. These data suggest that, when included in the bio-corona of TiO2 NP, LPS exhibits enhanced and time-shifted pro-inflammatory effects

  11. Modeling the LPS Neutralization Activity of Anti-Endotoxins

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    Virapong Prachayasittikul

    2009-05-01

    Full Text Available Bacterial lipopolysaccharides (LPS, also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS is considered to be a major virulence factor as it strongly stimulates the secretion of pro-inflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPS neutralization activities of anti-endotoxins were performed using charge and quantum chemical descriptors. Artificial neural network implementing the back-propagation algorithm was selected for the multivariate analysis. The predicted activities from leave-one-out cross-validation were well correlated with the experimental values as observed from the correlation coefficient and root mean square error of 0.930 and 0.162, respectively. Similarly, the external testing set also yielded good predictivity with correlation coefficient and root mean square error of 0.983 and 0.130. The model holds great potential for the rational design of novel and robust compounds with enhanced neutralization activity.

  12. Apolipoprotein CI enhances the biological response to LPS via the CD14/TLR4 pathway by LPS-binding elements in both its N- and C-terminal helix

    NARCIS (Netherlands)

    Berbé, J.F.P.; Coomans, C.P.; Westerterp, M.; Romijn, J.A.; Havekes, L.M.; Rensen, P.C.N.

    2010-01-01

    Timely sensing of lipopolysaccharide (LPS) is critical for the host to fight invading Gram-negative bacteria. We recently showed that apolipoprotein CI (apoCI) (apoCI1-57) avidly binds to LPS, involving an LPS-binding motif (apoCI48-54), and thereby enhances the LPS-induced

  13. Apolipoprotein CI enhances the biological response to LPS via the CD14/TLR4 pathway by LPS-binding elements in both its N- and C-terminal helix

    NARCIS (Netherlands)

    Berbée, Jimmy F. P.; Coomans, Claudia P.; Westerterp, Marit; Romijn, Johannes A.; Havekes, Louis M.; Rensen, Patrick C. N.

    2010-01-01

    Timely sensing of lipopolysaccharide (LPS) is critical for the host to fight invading Gram-negative bacteria. We recently showed that apolipoprotein CI (apoCI) (apoCI1-57) avidly binds to LPS, involving an LPS-binding motif (apoCI48-54), and thereby enhances the LPS-induced inflammatory response.

  14. Immunoelectron microscopy of lipopolysaccharide in Chlamydia trachomatis

    DEFF Research Database (Denmark)

    Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

    1989-01-01

    Monoclonal antibodies (MAb) specific for Chlamydia trachomatis lipopolysaccharide (LPS) and major outer membrane protein (MOMP) were used for immunoelectron microscopy analysis. MAb specific for MOMP showed strong reaction with the chlamydial surface, whereas MAb specific for LPS showed strong...... association of gold particles with the periphery of the chlamydial body. After fixation of the chlamydia cells, the reactivity was, however, similar to the anti-MOMP reactivity. Enzyme-linked immunosorbent assay showed that MAb specific for LPS could remove LPS from the chlamydial membrane....

  15. Biological reactivity of Moraxella bovis lipopolysaccharide.

    Science.gov (United States)

    Johansen, K A; Wannemuehler, M J; Rosenbusch, R F

    1990-01-01

    Lipopolysaccharide (LPS) was isolated from Moraxella bovis 118F and ATCC 10900, M ovis ATCC 33078, and M phenylpyruvica ATCC 23333 by hot phenol-water extraction. In silver-stained sodium dodecyl sulfate polyacrylamide electrophoresis gels, M bovis 118F LPS had a smooth profile, whereas the other Moraxella preparations appeared to be rough. The LPS preparations induced pyrogenicity and dermal Shwartzman reactions in rabbits, and induced production of tumor necrosis factor and interleukin-1 in vitro. Induction of tumor necrosis factor appeared to be among the most potent biological activities of M bovis LPS.

  16. Effects of aging on endotoxin tolerance induced by lipopolysaccharides derived from Porphyromonas gingivalis and Escherichia coli.

    Science.gov (United States)

    Sun, Ying; Li, Hui; Yang, Mi-Fang; Shu, Wei; Sun, Meng-Jun; Xu, Yan

    2012-01-01

    Periodontitis is a bacterially induced chronic inflammatory disease. Exposure of the host to periodontal pathogens and their virulence factors induces a state of hyporesponsiveness to subsequent stimulations, termed endotoxin tolerance. Aging has a profound effect on immune response to bacteria challenge. The aim of this study was to explore the effects of aging on endotoxin tolerance induced by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) and Escherichia coli (E. coli) LPS in murine peritoneal macrophages. We studied the cytokine production (TNF-α and IL-10) and Toll-like receptor 2, 4 (TLR2, 4) gene and protein expressions in peritoneal macrophages from young (2-month-old) and middle-aged (12-month-old) ICR mice following single or repeated P. gingivalis LPS or E. coli LPS stimulation. Pretreatment of peritoneal macrophages with P. gingivalis LPS or E. coli LPS resulted in a reduction in TNF-α production and an increase in IL-10 production upon secondary stimulation (plead to the incontrollable periodontal inflammation in older adults.

  17. Nicotine ameliorates schizophrenia-like cognitive deficits induced by maternal LPS exposure: a study in rats

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    Uta Waterhouse

    2016-10-01

    Full Text Available Maternal exposure to infectious agents is a predisposing factor for schizophrenia with associated cognitive deficits in offspring. A high incidence of smoking in these individuals in adulthood might be, at least in part, due to the cognitive-enhancing effects of nicotine. Here, we have used prenatal exposure to maternal lipopolysaccharide (LPS, bacterial endotoxin at different time points as a model for cognitive deficits in schizophrenia to determine whether nicotine reverses any associated impairments. Pregnant rats were treated subcutaneously with LPS (0.5 mg/kg at one of three neurodevelopmental time periods [gestation days (GD 10-11, 15-16, 18-19]. Cognitive assessment in male offspring commenced in early adulthood [postnatal day (PND 60] and included: prepulse inhibition (PPI, latent inhibition (LI and delayed non-matching to sample (DNMTS. Following PND 100, daily nicotine injections (0.6 mg/kg, subcutaneously were administered, and animals were re-tested in the same tasks (PND 110. Only maternal LPS exposure early during fetal neurodevelopment (GD 10-11 resulted in deficits in all tests compared to animals that had been prenatally exposed to saline at the same gestational time point. Repeated nicotine treatment led to global (PPI and selective (LI improvements in performance. Early but not later prenatal LPS exposure induced consistent deficits in cognitive tests with relevance for schizophrenia. Nicotine reversed the LPS-induced deficits in selective attention (LI and induced a global enhancement of sensorimotor gating (PPI.

  18. Effects of lipopolysaccharides on the corrosion behavior of Ni-Cr and Co-Cr alloys.

    Science.gov (United States)

    Yu, Weiqiang; Qian, Chao; Weng, Weimin; Zhang, Songmei

    2016-08-01

    Lipopolysaccharides (LPS) are constituents of gingival crevicular fluid and may affect the base metal alloys used in metal ceramic crowns. The role of LPS in base metal alloys is currently unknown. The purpose of this in vitro study was to evaluate the effects of gram-negative bacterial LPS on the electrochemical behavior of Ni-Cr and Co-Cr alloys. Alloy specimens were divided into 4 groups according to Escherichia coli LPS concentration (0, 0.15, 15, and 150 μg/mL) in acidic saliva (pH 5). Open circuit potential (OCP) and potentiodynamic polarization behavior were examined using a computer-controlled potentiostat. Metal ions released from the 2 alloys were measured by immersion in LPS-free solution and 150 μg/mL LPS solution and analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Data were evaluated using 1-way ANOVA (α=.05). Compared with control groups, medium LPS concentration (15 μg/mL) accelerated Ni-Cr alloy corrosion (Palloy corrosion (Pcorrosion current density, and polarization resistance parameters. After immersion in high LPS concentrations (150 μg/mL), a slight increase in Ni ion release (P >.05) was observed for the Ni-Cr alloy, while a more significant Co ion release (Palloy. LPS negatively affected the electrochemical behavior of both the Ni-Cr and Co-Cr alloys. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  19. MOLECULAR DYNAMICS STUDY OF INTERACTIONS OF POLYMYXIN B3 AND ITS ALA-MUTANTS WITH LIPOPOLYSACCHARIDE

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    Lisnyak Yu. V.

    2015-12-01

    Full Text Available Introduction. Emergence of nosocomial bacterial pathogens (especially Gram-negative bacteria with multiple resistance against almost all available antibiotics is a growing medical problem. No novel drugs targeting multidrug-resistant Gram-negative bacteria have been developed in recent years. In this context, there has been greatly renewed interest to cyclic lipodecapeptides polymyxins. Polymyxins exhibit rapid bactericidal activity, they are specific and highly potent against Gramnegative bacteria, but have potential nephrotoxic side effects. So polymyxins are attractive lead compounds to develop analogues with improved microbiological, pharmacological and toxicological properties. A detailed knowledge of the molecular mechanisms of polymyxin interactions with its cell targets is a prerequisite for the purposeful improvement of its therapeutic properties. The primary cell target of a polymyxin is a lipopolysaccharide (LPS in the outer membrane of Gram-negative bacteria. The binding site of polymyxin on LPS has been supposed to be Kdo2-lipid A fragment. Methods. For all molecular modeling and molecular dynamics simulation experiments the YASARA suite of programs was used. Complex of antimicrobial peptide polymyxin В3 (PmB3 with Kdo2-lipid A portion of E. coli lipopolysaccharide was constructed by rigid docking with flexible side chains of the peptide. By alanine scanning of polymyxin В3 bound to LPS followed by simulated annealing minimization of the complexes in explicit water environment, the molecular aspects of PmB3-LPS binding have been studied by 20 ns molecular dynamics simulations at 298 K and pH 7.0. The AMBER03 force field was used with a 1.05 nm force cutoff. To treat long range electrostatic interactions the Particle Mesh Ewald algorithm was used. Results. Ala-mutations of polymyxin’s residues Dab1, Dab3, Dab5, Dab8 and Dab9 in the PmB3-LPS complex caused sustained structural changes resulting in the notable loss in stability of

  20. Genomic instability in liver cells caused by an LPS-induced bystander-like effect.

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    Igor Kovalchuk

    Full Text Available Bacterial infection has been linked to carcinogenesis, however, there is lack of knowledge of molecular mechanisms that associate infection with the development of cancer. We analyzed possible effects of the consumption of heat-killed E. coli O157:H7 cells or its cellular components, DNA, RNA, protein or lipopolysaccharides (LPS on gene expression in naïve liver cells. Four week old mice were provided water supplemented with whole heat-killed bacteria or bacterial components for a two week period. One group of animals was sacrificed immediately, whereas another group was allowed to consume uncontaminated tap water for an additional two weeks, and liver samples were collected, post mortem. Liver cells responded to exposure of whole heat-killed bacteria and LPS with alteration in γH2AX levels and levels of proteins involved in proliferation, DNA methylation (MeCP2, DNMT1, DNMT3A and 3B or DNA repair (APE1 and KU70 as well as with changes in the expression of genes involved in stress response, cell cycle control and bile acid biosynthesis. Other bacterial components analysed in this study did not lead to any significant changes in the tested molecular parameters. This study suggests that lipopolysaccharides are a major component of Gram-negative bacteria that induce molecular changes within naïve cells of the host.

  1. Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium

    Science.gov (United States)

    Romero, Stefany; Esquinas, Paula; Patiño, Pilar; Martínez, Nhora

    2017-01-01

    The role of the P. multocida lipopolysaccharide (LPS) as a putative adhesin during the early stages of infection with this bacterium in the respiratory epithelium of rabbits was investigated. By light microscopy and double enzyme labeling of nasal septa tissues, the amount of bacteria attached to the respiratory epithelium and the amount of LPS present in goblet cells at different experimental times were estimated. Transmission electron microscopy (TEM) and LPS labeling with colloidal gold particles were also used to determine the exact location of LPS in the cells. Septa that were challenged with LPS of P. multocida and 30 minutes later with P. multocida showed more adherent bacteria and more severe lesions than the other treatments. Free LPS was observed in the lumen of the nasal septum, forming bilamellar structures and adhering to the cilia, microvilli, cytoplasmic membrane, and cytoplasm of epithelial ciliated and goblet cells. The above findings suggest that P. multocida LPS plays an important role in the process of bacterial adhesion and that it has the ability of being internalized into host cells. PMID:28251016

  2. Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium

    Directory of Open Access Journals (Sweden)

    Carolina Gallego

    2017-01-01

    Full Text Available The role of the P. multocida lipopolysaccharide (LPS as a putative adhesin during the early stages of infection with this bacterium in the respiratory epithelium of rabbits was investigated. By light microscopy and double enzyme labeling of nasal septa tissues, the amount of bacteria attached to the respiratory epithelium and the amount of LPS present in goblet cells at different experimental times were estimated. Transmission electron microscopy (TEM and LPS labeling with colloidal gold particles were also used to determine the exact location of LPS in the cells. Septa that were challenged with LPS of P. multocida and 30 minutes later with P. multocida showed more adherent bacteria and more severe lesions than the other treatments. Free LPS was observed in the lumen of the nasal septum, forming bilamellar structures and adhering to the cilia, microvilli, cytoplasmic membrane, and cytoplasm of epithelial ciliated and goblet cells. The above findings suggest that P. multocida LPS plays an important role in the process of bacterial adhesion and that it has the ability of being internalized into host cells.

  3. Low pH Environmental Stress Inhibits LPS and LTA-Stimulated Proinflammatory Cytokine Production in Rat Alveolar Macrophages

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    Stanley F. Fernandez

    2013-01-01

    Full Text Available Gastric aspiration increases the risks for developing secondary bacterial pneumonia. Cytokine elaboration through pathogen recognition receptors (PRRs is an important mechanism in initiating innate immune host response. Effects of low pH stress, a critical component of aspiration pathogenesis, on the PRR pathways were examined, specifically toll-like receptor-2 (TLR2 and TLR4, using isolated rat alveolar macrophages (aMØs. We assessed the ability of aMØs after brief exposure to acidified saline to elaborate proinflammatory cytokines in response to lipopolysaccharide (LPS and lipoteichoic acid (LTA stimulation, known ligands of TLR4 and TLR2, respectively. Low pH stress reduced LPS- and LTA-mediated cytokine release (CINC-1, MIP-2, TNF-, MCP-1, and IFN-. LPS and LTA increased intracellular Ca2+ concentrations while Ca2+ chelation by BAPTA decreased LPS- and LTA-mediated cytokine responses. BAPTA blocked the effects of low pH stress on most of LPS-stimulated cytokines but not of LTA-stimulated responses. In vivo mouse model demonstrates suppressed E. coli and S. pneumoniae clearance following acid aspiration. In conclusion, low pH stress inhibits antibacterial cytokine response of aMØs due to impaired TLR2 (MyD88 pathway and TLR4 signaling (MyD88 and TRIF pathways. The role of Ca2+ in low pH stress-induced signaling is complex but appears to be distinct between LPS- and LTA-mediated responses.

  4. Tec kinases regulate actin assembly and cytokine expression in LPS-stimulated human neutrophils via JNK activation.

    Science.gov (United States)

    Zemans, Rachel L; Arndt, Patrick G

    2009-01-01

    The acute inflammatory response involves neutrophils wherein recognition of bacterial products, such as lipopolysaccharide (LPS), activates intracellular signaling pathways. We have shown that the mitogen-activated protein kinase (MAPK) c-Jun NH(2) terminal kinase (JNK) is activated by LPS in neutrophils and plays a critical role in monocyte chemoattractant protein (MCP)-1 expression and actin assembly. As the Tec family kinases are expressed in neutrophils and regulate activation of the MAPKs in other cell systems, we hypothesized that the Tec kinases are an upstream component of the signaling pathway leading to LPS-induced MAPKs activation in neutrophils. Herein, we show that the Tec kinases are activated in LPS-stimulated human neutrophils and that inhibition of the Tec kinases, with leflunomide metabolite analog (LFM-A13), decreased LPS-induced JNK, but not p38, activity. Furthermore, LPS-induced actin polymerization as well as MCP-1, tumor necrosis factor-alpha, interleukin-6, and interleukin-1beta expression are dependent on Tec kinase activity.

  5. LPS enhances expression of CD204 through the MAPK/ERK pathway in murine bone marrow macrophages.

    Science.gov (United States)

    Hashimoto, Ryota; Kakigi, Ryo; Nakamura, Kyoko; Itoh, Seigo; Daida, Hiroyuki; Okada, Takao; Katoh, Youichi

    2017-11-01

    Lipopolysaccharide (LPS) is a main component of the Gram-negative bacterial cell wall and is associated with a greater risk of atherosclerosis development in periodontal disease. LPS has been reported to increase both CD36 and CD204 expression and enhance the uptake of modified low-density lipoprotein (LDL). However, the signaling pathways by which LPS enhances these expression levels and function have not been fully elucidated, although the clarification of these signaling pathways is important for identifying therapeutic targets for atherosclerosis. We have shown here that LPS activated the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway, increased both CD204 and CD36 expression, and enhanced the uptake of acetylated-LDL (Ac-LDL) in mouse bone marrow macrophages. The MAPK/ERK kinase (MEK) inhibitors, U0126 (1 μM) and PD0325901 (10 nM), did not affect the expression of either CD36 or CD204 or the uptake of Ac-LDL under normal conditions (no treatment with LPS). In contrast, U0126 (1 μM) and PD0325901 (10 nM) blocked the LPS-induced increase in Ac-LDL uptake and CD204 expression but not CD36 expression. These results suggest that LPS may increase Ac-LDL uptake and enhance CD204 expression through MAPK/ERK activation and CD36 expression through an ERK-independent pathway. Since MEK inhibitors block CD204 expression in mouse BM macrophages only under LPS treatment but not under normal conditions, a MEK inhibitor might be a good candidate compound for the treatment of LPS-induced atherosclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Dual effects of soluble CD14 on LPS priming of neutrophils

    NARCIS (Netherlands)

    Troelstra, A; Giepmans, B N; Van Kessel, K P; Lichenstein, H S; Verhoef, J; Van Strijp, J A

    To evaluate the effect of soluble CD14 (sCD14) on human neutrophil response to lipopolysaccharide (LPS), we developed an LPS-priming assay that measures the chemiluminescence response to N-formyl-methionyl-leucyl-phenylalanine stimulation. Priming by 1 ng/mL rough LPS occurred in the presence of

  7. Development of a rapid multiplex PCR assay to genotype Pasteurella multocida strains by use of the lipopolysaccharide outer core biosynthesis locus.

    Science.gov (United States)

    Harper, Marina; John, Marietta; Turni, Conny; Edmunds, Mark; St Michael, Frank; Adler, Ben; Blackall, P J; Cox, Andrew D; Boyce, John D

    2015-02-01

    Pasteurella multocida is a Gram-negative bacterial pathogen that is the causative agent of a wide range of diseases in many animal species, including humans. A widely used method for differentiation of P. multocida strains involves the Heddleston serotyping scheme. This scheme was developed in the early 1970s and classifies P. multocida strains into 16 somatic or lipopolysaccharide (LPS) serovars using an agar gel diffusion precipitin test. However, this gel diffusion assay is problematic, with difficulties reported in accuracy, reproducibility, and the sourcing of quality serovar-specific antisera. Using our knowledge of the genetics of LPS biosynthesis in P. multocida, we have developed a multiplex PCR (mPCR) that is able to differentiate strains based on the genetic organization of the LPS outer core biosynthesis loci. The accuracy of the LPS-mPCR was compared with classical Heddleston serotyping using LPS compositional data as the "gold standard." The LPS-mPCR correctly typed 57 of 58 isolates; Heddleston serotyping was able to correctly and unambiguously type only 20 of the 58 isolates. We conclude that our LPS-mPCR is a highly accurate LPS genotyping method that should replace the Heddleston serotyping scheme for the classification of P. multocida strains. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Allergy-inducing nickel concentration is lowered by lipopolysaccharide at both the sensitization and elicitation steps in a murine model.

    Science.gov (United States)

    Kinbara, M; Sato, N; Kuroishi, T; Takano-Yamamoto, T; Sugawara, S; Endo, Y

    2011-02-01

    Nickel (Ni) is the major cause of contact allergy. We previously found that lipopolysaccharide (LPS, a cell-surface component of gram-negative bacteria) markedly promotes Ni allergy in a murine model. Establishing the minimum concentration or amount of Ni needed to induce allergic responses may help us to prevent or reduce such responses. Using the above murine model, we examined the influence of LPS on the minimum allergy-inducing concentrations of Ni (Ni-MAICs) at the sensitization step and at the elicitation step. BALB/c mice were sensitized by intraperitoneal injection of a mixture containing various concentrations of LPS and NiCl(2). Ten days later, their ear pinnas were challenged intradermally with a mixture containing various concentrations of LPS and NiCl(2), and ear swelling was measured. Without LPS, the Ni-MAICs at the sensitization and elicitation steps were around 1×10(-2) mol L(-1) and 1×10(-5) mol L(-1) , respectively. Sensitization with NiCl(2) + LPS did not alter the value at elicitation. Surprisingly, LPS markedly reduced these Ni-MAICs (to around 1×10(-6) molL(-1) at sensitization, with 25 μg mL(-1) LPS, and 1×10(-12) mol L(-1) at elicitation, with 0·5 μg mL(-1) LPS). The effect of LPS depended on its concentration and the timing of its injection. Our findings suggest that: (i) Ni-MAIC is higher at sensitization than at elicitation; (ii) once sensitization is established, Ni allergy can easily be induced by a low concentration of Ni; and (iii) a bacterial milieu or infection may greatly facilitate the establishment and elicitation of Ni allergy. © 2010 The Authors. BJD © 2010 British Association of Dermatologists.

  9. Biochemical principle of Limulus test for detecting bacterial endotoxins

    OpenAIRE

    Iwanaga, Sadaaki

    2007-01-01

    A hemocyte lysate from horseshoe crab (Limulus) produced a gel, when exposed to Gram-negative bacterial endotoxins, lipopolysaccharides (LPS). This gelation reaction of the lysate, so-called Limulus test, has been widely employed as a simple and very sensitive assay method for endotoxins. Recent biochemical studies on the principle of Limulus test indicate that the hemocytes contain several serine protease zymogens, which constitute a coagulation cascade triggered by endotoxins, and that ther...

  10. OPTICAL IMAGING OF LIPOPOLYSACCHARIDE-INDUCED OXIDATIVE STRESS IN ACUTE LUNG INJURY FROM HYPEROXIA AND SEPSIS

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    REYHANEH SEPEHR

    2013-07-01

    Full Text Available Reactive oxygen species (ROS have been implicated in the pathogenesis of many acute and chronic pulmonary disorders such as acute lung injury (ALI in adults and bronchopulmonary dysplasia (BPD in premature infants. Bacterial infection and oxygen toxicity, which result in pulmonary vascular endothelial injury, contribute to impaired vascular growth and alveolar simplification seen in the lungs of premature infants with BPD. Hyperoxia induces ALI, reduces cell proliferation, causes DNA damage and promotes cell death by causing mitochondrial dysfunction. The objective of this study was to use an optical imaging technique to evaluate the variations in fluorescence intensities of the auto-fluorescent mitochondrial metabolic coenzymes, NADH and FAD in four different groups of rats. The ratio of these fluorescence signals (NADH/FAD, referred to as NADH redox ratio (NADH RR has been used as an indicator of tissue metabolism in injuries. Here, we investigated whether the changes in metabolic state can be used as a marker of oxidative stress caused by hyperoxia and bacterial lipopolysaccharide (LPS exposure in neonatal rat lungs. We examined the tissue redox states of lungs from four groups of rat pups: normoxic (21% O2 pups, hyperoxic (90% O2 pups, pups treated with LPS (normoxic + LPS, and pups treated with LPS and hyperoxia (hyperoxic + LPS. Our results show that hyperoxia oxidized the respiratory chain as reflected by a ~ 31% decrease in lung tissue NADH RR as compared to that for normoxic lungs. LPS treatment alone or with hyperoxia had no significant effect on lung tissue NADH RR as compared to that for normoxic or hyperoxic lungs, respectively. Thus, NADH RR serves as a quantitative marker of oxidative stress level in lung injury caused by two clinically important conditions: hyperoxia and LPS exposure.

  11. LPS and cytokines inhibit rat cardiomyocyte contractility in vitro

    Science.gov (United States)

    Hobai, Ion A.; Morse, Justin C.; Siwik, Deborah A.; Colucci, Wilson S.

    2014-01-01

    Background Sepsis-induced cardiomyopathy (SIC) is thought to be the result of detrimental effects of inflammatory mediators on cardiac muscle. Here we studied the effects of prolonged (24 ± 4 h) exposure of adult rat ventricular myocytes (ARVM) to bacterial lipopolysaccharide (LPS) and inflammatory cytokines tumor necrosis factor (TNF) and interleukins-1 (IL-1) and -6 (IL-6). Materials and methods We measured sarcomere shortening (SS) and cellular calcium (Ca2+) transients (ΔCai, with fura-2AM) in isolated cardiomyocytes externally paced at 5Hz at 37 °C. Results SS decreased after incubation with LPS (100 µg/ml), IL-1 (100 ng/ml) and IL-6 (30 ng/ml), but not with lesser doses of these mediators, or TNF (10 –100 ng/ml). A combination of LPS (100 µg/ml), TNF, IL-1 and IL-6 (each 100 ng/ml; i.e. “Cytomix-100”) induced a maximal decrease in SS and ΔCai. Sarcoplasmic reticulum (SR) Ca2+ load (CaSR, measured with caffeine) was unchanged by Cytomix-100, however, SR fractional release (ΔCai/CaSR) was decreased. Underlying these effects, Ca2+ influx into the cell (via L-type Ca2+ channels) and Ca2+ extrusion via Na+/Ca2+ exchange were decreased by Cytomix-100. SR Ca2+ pump (SERCA) was not affected. Conclusions Prolonged exposure of ARVM to a mixture of LPS and inflammatory cytokines inhibits cell contractility. The effect is mediated by the inhibition of Ca2+ influx via LTCC, and partially opposed by the inhibition of Na+/Ca2+ exchange. Since both mechanisms are commonly seen in animal models of SIC, we conclude that prolonged challenge with Cytomix-100 of ARVM may represent an accurate in vitro model for SIC. PMID:25439505

  12. The role of lipopolysaccharide injected systemically in the reactivation of collagen-induced arthritis in mice

    Science.gov (United States)

    Yoshino, Shin; Ohsawa, Motoyasu

    2000-01-01

    We investigated the role of bacterial lipopolysaccharide (LPS) in the reactivation of autoimmune disease by using collagen-induced arthritis (CIA) in mice in which autoimmunity to the joint cartilage component type II collagen (CII) was involved.CIA was induced by immunization with CII emulsified with complete Freund's adjuvant at the base of the tail (day 0) followed by a booster injection on day 21. Varying doses of LPS from E. coli were i.p. injected on day 50.Arthritis began to develop on day 25 after immunization with CII and reached a peak on day 35. Thereafter, arthritis subsided gradually but moderate joint inflammation was still observed on day 50. An i.p. injection of LPS on day 50 markedly reactivated arthritis on a dose-related fashion. Histologically, on day 55, there were marked oedema of synovium which had proliferated by the day of LPS injection, new formation of fibrin, and intense infiltration of neutrophils accompanied with a large number of mononuclear cells. The reactivation of CIA by LPS was associated with increases in anti-CII IgG and IgG2a antibodies as well as various cytokines including IL-12, IFN-γ, IL-1β, and TNF-α. LPS from S. enteritidis, S. typhimurium, and K. neumoniae and its component, lipid A from E. coli also reactivated the disease. Polymyxin B sulphate suppressed LPS- or lipid A-induced reactivation of CIA.These results suggest that LPS may play an important role in the reactivation of autoimmune joint inflammatory diseases such as rheumatoid arthritis in humans. PMID:10742285

  13. Effects of aging on endotoxin tolerance induced by lipopolysaccharides derived from Porphyromonas gingivalis and Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Ying Sun

    Full Text Available Periodontitis is a bacterially induced chronic inflammatory disease. Exposure of the host to periodontal pathogens and their virulence factors induces a state of hyporesponsiveness to subsequent stimulations, termed endotoxin tolerance. Aging has a profound effect on immune response to bacteria challenge. The aim of this study was to explore the effects of aging on endotoxin tolerance induced by Porphyromonas gingivalis (P. gingivalis lipopolysaccharide (LPS and Escherichia coli (E. coli LPS in murine peritoneal macrophages.We studied the cytokine production (TNF-α and IL-10 and Toll-like receptor 2, 4 (TLR2, 4 gene and protein expressions in peritoneal macrophages from young (2-month-old and middle-aged (12-month-old ICR mice following single or repeated P. gingivalis LPS or E. coli LPS stimulation. Pretreatment of peritoneal macrophages with P. gingivalis LPS or E. coli LPS resulted in a reduction in TNF-α production and an increase in IL-10 production upon secondary stimulation (p<0.05, and the markedly lower levels of TNF-α and higher levels of IL-10 were observed in macrophages from young mice compared with those from middle-aged mice (p<0.05. In addition, LPS restimulations also led to the significantly lower expression levels of TLR2, 4 mRNA and protein in macrophages from young mice (p<0.05.Repeated LPS stimulations triggered endotoxin tolerance in peritoneal macrophages and the ability to develop tolerance in young mice was more excellent. The impaired ability to develop endotoxin tolerance resulted from aging might be related to TLR2, 4 and might lead to the incontrollable periodontal inflammation in older adults.

  14. Dynamic lipopolysaccharide transfer cascade to TLR4/MD2 complex via LBP and CD14

    OpenAIRE

    Kim, Soo Jin; Kim, Ho Min

    2017-01-01

    Toll-like receptor 4 (TLR4) together with MD2, one of the key pattern recognition receptors for a pathogen-associated molecular pattern, activates innate immunity by recognizing lipopolysaccharide (LPS) of Gram-negative bacteria. Although LBP and CD14 catalyze LPS transfer to the TLR4/MD2 complex, the detail mechanisms underlying this dynamic LPS transfer remain elusive. Using negative-stain electron microscopy, we visualized the dynamic intermediate complexes during LPS transfer?LBP/LPS mice...

  15. Preparation of a lipopolysaccharide from ''Escherichia coli 0111a, 0111b, K58: H21'' bacterial wall, labeled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, D.; Solano, M.A.

    1980-01-01

    A brief description is made of the morphological and chemical structure of lipopolysaccharides, as well as its occurence in nature and its mechanisms of action. It is emphasized the usefulness of the labelled lipopolysaccharide for actual biochemical and biomedical research. The method for the labelling, isolation and purification of carbon-14 lipopolysaccharide is described. (auth.)

  16. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela [Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Av. Haya de la Torre y Medina Allende, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Gutiérrez, Silvina; Torres, Alicia Inés [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); De Paul, Ana Lucía, E-mail: adepaul@cmefcm.uncor.edu [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina)

    2013-11-15

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  17. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    International Nuclear Information System (INIS)

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto; Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela; Gutiérrez, Silvina; Torres, Alicia Inés; De Paul, Ana Lucía

    2013-01-01

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  18. Structure-activity relationships of lipopolysaccharide sequestration in guanylhydrazone-bearing lipopolyamines.

    Science.gov (United States)

    Wu, Wenyan; Sil, Diptesh; Szostak, Michal L; Malladi, Subbalakshmi S; Warshakoon, Hemamali J; Kimbrell, Matthew R; Cromer, Jens R; David, Sunil A

    2009-01-15

    The toxicity of gram-negative bacterial endotoxin (lipopolysaccharide, LPS) resides in its structurally highly conserved glycolipid component called lipid A. Our major goal has been to develop small-molecules that would sequester LPS by binding to the lipid A moiety, so that it could be useful for the prophylaxis or adjunctive therapy of gram-negative sepsis. We had previously identified in rapid-throughput screens several guanylhydrazones as potent LPS binders. We were desirous of examining if the presence of the guanylhydrazone (rather than an amine) functionality would afford greater LPS sequestration potency. In evaluating a congeneric set of guanylhydrazone analogues, we find that C(16) alkyl substitution is optimal in the N-alkylguanylhydrazone series; a homospermine analogue with the terminal amine N-alkylated with a C(16) chain with the other terminus of the molecule bearing an unsubstituted guanylhydrazone moiety is marginally more active, suggesting very slight, if any, steric effects. Neither C(16) analogue is significantly more active than the N-C(16)-alkyl or N-C(16)-acyl compounds that we had characterized earlier, indicating that basicity of the phosphate-recognizing cationic group, is not a determinant of LPS sequestration activity.

  19. Lipopolysaccharide induces immune activation and SIV replication in rhesus macaques of Chinese origin.

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    Rong Bao

    Full Text Available BACKGROUND: Chronic immune activation is a hallmark of progressive HIV infection and a key determinant of immunodeficiency in HIV-infected individuals. Bacterial lipopolysaccharide (LPS in the circulation has been implicated as a key factor in HIV infection-related systemic immune activation. We thus investigate the impact of LPS on systemic immune activation in simian immunodeficiency virus (SIV-infected rhesus macaques of Chinese origin. METHODS: The animals were inoculated intravenously with SIVmac239. The levels of plasma viral load and host inflammatory cytokines in PBMC were measured by real-time RT-PCR. CD4/CD8 ratio and systemic immune activation markers were examined by flow cytometric analysis of PBMCs. White blood cell and neutrophil counts and C Reactive Protein levels were determined using biochemistry analyzer. The plasma levels of LPS were determined by Tachypleus Amebocyte Lysate (TAL test. RESULTS: The animals inoculated with SIVmac239 became infected as evidenced by the increased plasma levels of SIV RNA and decreased CD4/CD8 ratio. LPS administration of SIV-infected animals induced a transient increase of plasma SIV RNA and immune activation, which was indicated by the elevated expression of the inflammatory cytokines and CD4+HLA-DR+ T cells in PBMCs. CONCLUSIONS: These data support the concept that LPS is a driving factor in systemic immune activation of HIV disease.

  20. Protective Effect of Argan and Olive Oils against LPS-Induced Oxidative Stress and Inflammation in Mice Livers.

    Science.gov (United States)

    El Kamouni, Soufiane; El Kebbaj, Riad; Andreoletti, Pierre; El Ktaibi, Abderrahim; Rharrassi, Issam; Essamadi, Abdelkhalid; El Kebbaj, M'hammed Saïd; Mandard, Stéphane; Latruffe, Norbert; Vamecq, Joseph; Nasser, Boubker; Cherkaoui-Malki, Mustapha

    2017-10-19

    Sepsis causes severe dysregulation of organ functions, via the development of oxidative stress and inflammation. These pathophysiological mechanisms are mimicked in mice injected with bacterial lipopolysaccharide (LPS). Here, protective properties of argan oil against LPS-induced oxidative stress and inflammation are explored in the murine model. Mice received standard chow, supplemented with argan oil (AO) or olive oil (OO) for 25 days, before septic shock was provoked with a single intraperitoneal injection of LPS, 16 hours prior to animal sacrifice. In addition to a rise in oxidative stress and inflammatory markers, injected LPS also caused hepatotoxicity, accompanied by hyperglycemia, hypercholesterolemia and hyperuremia. These LPS-associated toxic effects were blunted by AO pretreatment, as corroborated by normal plasma parameters and cell stress markers (glutathione: GSH) and antioxidant enzymology (catalase, CAT; superoxide dismutase, SOD and glutathione peroxidase, GPx). Hematoxylin-eosin staining revealed that AO can protect against acute liver injury, maintaining a normal status, which is pointed out by absent or reduced LPS-induced hepatic damage markers (i.e., alanine aminotransferase (ALT) and aspartate transaminase (AST)). Our work also indicated that AO displayed anti-inflammatory activity, due to down-regulations of genes encoding pro-inflammatory cytokines Interleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α) and in up-regulations of the expression of anti-inflammatory genes encoding Interleukin-4 (IL-4) and Interleukin-10 (IL-10). OO provided animals with similar, though less extensive, protective changes. Collectively our work adds compelling evidence to the protective mechanisms of AO against LPS-induced liver injury and hence therapeutic potentialities, in regard to the management of human sepsis. Activations of IL-4/Peroxisome Proliferator-Activated Receptors (IL-4/PPARs) signaling and, under LPS, an anti-inflammatory IL-10/Liver X

  1. Protective Effect of Argan and Olive Oils against LPS-Induced Oxidative Stress and Inflammation in Mice Livers

    Directory of Open Access Journals (Sweden)

    Soufiane El Kamouni

    2017-10-01

    Full Text Available Sepsis causes severe dysregulation of organ functions, via the development of oxidative stress and inflammation. These pathophysiological mechanisms are mimicked in mice injected with bacterial lipopolysaccharide (LPS. Here, protective properties of argan oil against LPS-induced oxidative stress and inflammation are explored in the murine model. Mice received standard chow, supplemented with argan oil (AO or olive oil (OO for 25 days, before septic shock was provoked with a single intraperitoneal injection of LPS, 16 hours prior to animal sacrifice. In addition to a rise in oxidative stress and inflammatory markers, injected LPS also caused hepatotoxicity, accompanied by hyperglycemia, hypercholesterolemia and hyperuremia. These LPS-associated toxic effects were blunted by AO pretreatment, as corroborated by normal plasma parameters and cell stress markers (glutathione: GSH and antioxidant enzymology (catalase, CAT; superoxide dismutase, SOD and glutathione peroxidase, GPx. Hematoxylin–eosin staining revealed that AO can protect against acute liver injury, maintaining a normal status, which is pointed out by absent or reduced LPS-induced hepatic damage markers (i.e., alanine aminotransferase (ALT and aspartate transaminase (AST. Our work also indicated that AO displayed anti-inflammatory activity, due to down-regulations of genes encoding pro-inflammatory cytokines Interleukin-6 (IL-6 and Tumor Necrosis Factor-α (TNF-α and in up-regulations of the expression of anti-inflammatory genes encoding Interleukin-4 (IL-4 and Interleukin-10 (IL-10. OO provided animals with similar, though less extensive, protective changes. Collectively our work adds compelling evidence to the protective mechanisms of AO against LPS-induced liver injury and hence therapeutic potentialities, in regard to the management of human sepsis. Activations of IL-4/Peroxisome Proliferator-Activated Receptors (IL-4/PPARs signaling and, under LPS, an anti-inflammatory IL-10/Liver

  2. Characterization of ovine hepatic gene expression profiles in response to Escherichia coli lipopolysaccharide using a bovine cDNA microarray

    Directory of Open Access Journals (Sweden)

    Boermans Herman J

    2006-11-01

    Full Text Available Abstract Background During systemic gram-negative bacterial infections, lipopolysaccharide (LPS ligation to the hepatic Toll-like receptor-4 complex induces the production of hepatic acute phase proteins that are involved in the host response to infection and limit the associated inflammatory process. Identifying the genes that regulate this hepatic response to LPS in ruminants may provide insight into the pathogenesis of bacterial diseases and eventually facilitate breeding of more disease resistant animals. The objective of this research was to profile the expression of ovine hepatic genes in response to Escherichia coli LPS challenge (0, 200, 400 ng/kg using a bovine cDNA microarray and quantitative real-time PCR (qRT-PCR. Results Twelve yearling ewes were challenged iv with E. coli LPS (0, 200, 400 ng/kg and liver biopsies were collected 4–5 hours post-challenge to assess hepatic gene expression profiles by bovine cDNA microarray and qRT-PCR analyses. The expression of CD14, C3, IL12R, NRAMP1, SOD and IGFBP3 genes was down regulated, whereas the expression of ACTHR, IFNαR, CD1, MCP-1 and GH was increased during LPS challenge. With the exception of C3, qRT-PCR analysis of 7 of these genes confirmed the microarray results and demonstrated that GAPDH is not a suitable housekeeping gene in LPS challenged sheep. Conclusion We have identified several potentially important genes by bovine cDNA microarray and qRT-PCR analyses that are differentially expressed during the ovine hepatic response to systemic LPS challenge. Their potential role in regulating the inflammatory response to LPS warrants further investigation.

  3. Lipopolysaccharide induces autotaxin expression in human monocytic THP-1 cells

    International Nuclear Information System (INIS)

    Li Song; Zhang Junjie

    2009-01-01

    Autotaxin (ATX) is a secreted enzyme with lysophospholipase D (lysoPLD) activity, which converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive phospholipid involved in numerous biological activities, including cell proliferation, differentiation, and migration. In the present study, we found that bacterial lipopolysaccharide (LPS), a well-known initiator of the inflammatory response, induced ATX expression in monocytic THP-1 cells. The activation of PKR, JNK, and p38 MAPK was required for the ATX induction. The LPS-induced ATX in THP-1 cells was characterized as the β isoform. In the presence of LPC, ATX could promote the migrations of THP-1 and Jurkat cells, which was inhibited by pertussis toxin (PTX), an inhibitor of Gi-mediated LPA receptor signaling. In summary, LPS induces ATX expression in THP-1 cells via a PKR, JNK and p38 MAPK-mediated mechanism, and the ATX induction is likely to enhance immune cell migration in proinflammatory response by regulating LPA levels in the microenvironment.

  4. Lipopolysaccharide contamination in intradermal DNA vaccination : toxic impurity or adjuvant?

    NARCIS (Netherlands)

    Berg, J.H. van den; Quaak, S.G.L.; Beijnen, J.H.; Hennink, W.E.; Storm, G.; Schumacher, T.N.; Haanen, J.B.A.G.; Nuijen, B.

    Purpose: Lipopolysaccharides (LPS) are known both as potential adjuvants for vaccines and as toxic impurity in pharmaceutical preparations. The aim of this study was to assess the role of LPS in intradermal DNA vaccination administered by DNA tattooing. Method: Micewere vaccinated with a model DNA

  5. Anti-inflammatory Effects of (-)-Epicatechin in Lipopolysaccharide ...

    African Journals Online (AJOL)

    HP

    Purpose: To investigate the protective effects of (-)-epicatechin on lipopolysaccharide (LPS)-induced inflammation in Raw 264.7 murine macrophages and the possible underlying mechanisms. Methods: The effects of epicatechin on LPS-stimulated production of inflammatory mediators in Raw. 264.7 cells were evaluated by ...

  6. Overnutrition Determines LPS Regulation of Mycotoxin Induced Neurotoxicity in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Ian James Martins

    2015-12-01

    Full Text Available Chronic neurodegenerative diseases are now associated with obesity and diabetes and linked to the developing and developed world. Interests in healthy diets have escalated that may prevent neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease. The global metabolic syndrome involves lipoprotein abnormalities and insulin resistance and is the major disorder for induction of neurological disease. The effects of bacterial lipopolysaccharides (LPS on dyslipidemia and NAFLD indicate that the clearance and metabolism of fungal mycotoxins are linked to hypercholesterolemia and amyloid beta oligomers. LPS and mycotoxins are associated with membrane lipid disturbances with effects on cholesterol interacting proteins, lipoprotein metabolism, and membrane apo E/amyloid beta interactions relevant to hypercholesterolemia with close connections to neurological diseases. The influence of diet on mycotoxin metabolism has accelerated with the close association between mycotoxin contamination from agricultural products such as apple juice, grains, alcohol, and coffee. Cholesterol efflux in lipoproteins and membrane cholesterol are determined by LPS with involvement of mycotoxin on amyloid beta metabolism. Nutritional interventions such as diets low in fat/carbohydrate/cholesterol have become of interest with relevance to low absorption of lipophilic LPS and mycotoxin into lipoproteins with rapid metabolism of mycotoxin to the liver with the prevention of neurodegeneration.

  7. Cigarette smoke inhibits macrophage sensing of Gram-negative bacteria and lipopolysaccharide: relative roles of nicotine and oxidant stress.

    Science.gov (United States)

    McMaster, S K; Paul-Clark, M J; Walters, M; Fleet, M; Anandarajah, J; Sriskandan, S; Mitchell, J A

    2008-02-01

    Smoking cigarettes is a major risk factor for the development of cardiovascular and respiratory disease. Moreover, smokers are more prone to infections. This has been associated with a suppression of the immune system by smoke. However, it is not clear how cigarette smoke affects the ability of immune cells to sense pathogens. Cigarette smoke contains a large number of molecules which may mediate responses on immune cells and of these, nicotine and oxidants have both been identified as inhibitory for the sensing of bacterial lipopolysaccharide (LPS). Nitric oxide synthase (NOS) and tumour necrosis factor (TNF)-alpha are both induced in macrophages on stimulation with Gram negative bacteria or LPS. We used murine macrophages stimulated with whole heat-killed bacteria or LPS. We measured output of NO (as nitrite) and TNFalpha, NOS protein by Western blotting and cellular oxidant stress. Cigarette smoke extract suppressed the ability of murine macrophages to release NO, but not TNFalpha in response to whole bacteria. Cigarette smoke extract also inhibited nitric oxide synthase II protein expression in response to LPS. The effects of cigarette smoke extract on nitrite formation stimulated by LPS were unaffected by inhibition of nicotinic receptors with alpha-bungarotoxin (100 units ml(-1)). However, the effects of cigarette smoke extract on LPS-induced nitrite formation were mimicked by hydrogen peroxide and reversed by the anti-oxidants N-acetyl cysteine and glutathione. We suggest that cigarette smoke exerts its immunosuppressive effects through an oxidant-dependent and not a nicotine-dependent mechanism.

  8. Hemin binding by Porphyromonas gingivalis strains is dependent on the presence of A-LPS.

    Science.gov (United States)

    Rangarajan, M; Aduse-Opoku, J; Paramonov, N A; Hashim, A; Curtis, M A

    2017-10-01

    Porphyromonas gingivalis is a Gram-negative black pigmenting anaerobe that is unable to synthesize heme [Fe(II)-protoporphyrin IX] or hemin [Fe(III)-protoporphyrin IX-Cl], which are important growth/virulence factors, and must therefore derive them from the host. Porphyromonas gingivalis expresses several proteinaceous hemin-binding sites, which are important in the binding/transport of heme/hemin from the host. It also synthesizes several virulence factors, namely cysteine-proteases Arg- and Lys-gingipains and two lipopolysaccharides (LPS), O-LPS and A-LPS. The gingipains are required for the production of the black pigment, μ-oxo-bisheme {[Fe(III)PPIX] 2 O}, which is derived from hemoglobin and deposited on the bacterial cell-surface leading to the characteristic black colonies when grown on blood agar. In this study we investigated the role of LPS in the deposition of μ-oxo-bisheme on the cell-surface. A P. gingivalis mutant defective in the biosynthesis of Arg-gingipains, namely rgpA/rgpB, produces brown colonies on blood agar and mutants defective in Lys-gingipain (kgp) and LPS biosynthesis namely porR, waaL, wzy, and pg0129 (α-1, 3-mannosyltransferase) produce non-pigmented colonies. However, only those mutants lacking A-LPS showed reduced hemin-binding when cells in suspension were incubated with hemin. Using native, de-O-phosphorylated and de-lipidated LPS from P. gingivalis W50 and porR strains, we demonstrated that hemin-binding to O-polysaccharide (PS) and to the lipid A moiety of LPS was reduced compared with hemin-binding to A-PS. We conclude that A-LPS in the outer-membrane of P. gingivalis serves as a scaffold/anchor for the retention of μ-oxo-bisheme on the cell surface and pigmentation is dependent on the presence of A-LPS. © 2017 The Authors. Molecular Oral Microbiology Published by John Wiley & Sons Ltd.

  9. Lipopolysaccharide-induced acute renal failure in conscious rats

    DEFF Research Database (Denmark)

    Jonassen, Thomas E N; Graebe, Martin; Promeneur, Dominique

    2002-01-01

    In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone......-alpha and lactate, inhibited the LPS-induced tachycardia, and exacerbated the acute LPS-induced fall in GFR. Furthermore, Ro-20-1724-treated rats were unable to maintain MAP. We conclude 1) PDE3 or PDE4 inhibition exacerbates LPS-induced renal failure in conscious rats; and 2) LPS treated rats develop an escape......, a phosphodiesterase type 3 (PDE3) inhibitor, and Ro-20-1724, a PDE4 inhibitor, on LPS-induced changes in renal function. Intravenous infusion of LPS (4 mg/kg b.wt. over 1 h) caused an immediate decrease in glomerular filtration rate (GFR) and proximal tubular outflow without changes in mean arterial pressure (MAP...

  10. Reconstruction of LPS Transfer Cascade Reveals Structural Determinants within LBP, CD14, and TLR4-MD2 for Efficient LPS Recognition and Transfer.

    Science.gov (United States)

    Ryu, Je-Kyung; Kim, Soo Jin; Rah, Sang-Hyun; Kang, Ji In; Jung, Hi Eun; Lee, Dongsun; Lee, Heung Kyu; Lee, Jie-Oh; Park, Beom Seok; Yoon, Tae-Young; Kim, Ho Min

    2017-01-17

    Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, binds Toll-like receptor 4 (TLR4)-MD2 complex and activates innate immune responses. LPS transfer to TLR4-MD2 is catalyzed by both LPS binding protein (LBP) and CD14. To define the sequential molecular interactions underlying this transfer, we reconstituted in vitro the entire LPS transfer process from LPS micelles to TLR4-MD2. Using electron microscopy and single-molecule approaches, we characterized the dynamic intermediate complexes for LPS transfer: LBP-LPS micelles, CD14-LBP-LPS micelle, and CD14-LPS-TLR4-MD2 complex. A single LBP molecule bound longitudinally to LPS micelles catalyzed multi-rounds of LPS transfer to CD14s that rapidly dissociated from LPB-LPS complex upon LPS transfer via electrostatic interactions. Subsequently, the single LPS molecule bound to CD14 was transferred to TLR4-MD2 in a TLR4-dependent manner. The definition of the structural determinants of the LPS transfer cascade to TLR4 may enable the development of targeted therapeutics for intervention in LPS-induced sepsis. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Dose-dependent changes in neuroinflammatory and arachidonic acid cascade markers with synaptic marker loss in rat lipopolysaccharide infusion model of neuroinflammation

    Directory of Open Access Journals (Sweden)

    Kellom Matthew

    2012-05-01

    Full Text Available Abstract Background Neuroinflammation, caused by six days of intracerebroventricular infusion of bacterial lipopolysaccharide (LPS, stimulates rat brain arachidonic acid (AA metabolism. The molecular changes associated with increased AA metabolism are not clear. We examined effects of a six-day infusion of a low-dose (0.5 ng/h and a high-dose (250 ng/h of LPS on neuroinflammatory, AA cascade, and pre- and post-synaptic markers in rat brain. We used artificial cerebrospinal fluid-infused brains as controls. Results Infusion of low- or high-dose LPS increased brain protein levels of TNFα, and iNOS, without significantly changing GFAP. High-dose LPS infusion upregulated brain protein and mRNA levels of AA cascade markers (cytosolic cPLA2-IVA, secretory sPLA2-V, cyclooxygenase-2 and 5-lipoxygenase, and of transcription factor NF-κB p50 DNA binding activity. Both LPS doses increased cPLA2 and p38 mitogen-activated protein kinase levels, while reducing protein levels of the pre-synaptic marker, synaptophysin. Post-synaptic markers drebrin and PSD95 protein levels were decreased with high- but not low-dose LPS. Conclusions Chronic LPS infusion has differential effects, depending on dose, on inflammatory, AA and synaptic markers in rat brain. Neuroinflammation associated with upregulated brain AA metabolism can lead to synaptic dysfunction.

  12. Response of the blood clotting system of the American horseshoe crab, Limulus polyphemus, to a novel form of lipopolysaccharide from a green alga.

    Science.gov (United States)

    Conrad, Mara L; Pardy, R L; Wainwright, Norman; Child, Alice; Armstrong, Peter B

    2006-08-01

    Lipopolysaccharide (LPS, endotoxin) is a component of Gram-negative bacteria and is the principal indicator to the innate immune systems of higher animals of a Gram-negative bacterial invasion. LPS activates the blood clotting system of the American horseshoe crab, Limulus polyphemus. By stimulating blood cell degranulation, LPS triggers the release of the proteins of the clotting system from the cells, and by activating a protease cascade that converts coagulogen, a soluble zymogen, to coagulin, the structural protein of the clot, LPS triggers the production of the fibrillar coagulin blood clot. Although originally thought to be restricted to the Gram-negative bacteria and the cyanobacteria, LPS, or a very similar molecule, has recently been described from a eukaryotic green alga, Chlorella. Here we show that, like LPS from Gram-negative bacteria, the algal molecule stimulates exocytosis of the Limulus blood cell and the clotting of coagulin. The coagulin clot efficiently entraps the cells of Chlorella in a network of fibrils. Invasion and erosion of the carapace by green algae is an important cause of mortality of Limulus, and it is suggested that the cellular response to aLPS may contribute to defense against this pathogen.

  13. Carum carvi Linn (Umbelliferae) Attenuates Lipopolysaccharide ...

    African Journals Online (AJOL)

    Lipopolysaccharide (LPS) was used to activate BV-2 microglia. Nitric oxide (NO) levels were measured using Griess assay. Inducible NO synthase (iNOS) and cyclooxygenase (COX) levels were evaluated by Western blot analysis. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production were evaluated by ...

  14. Garcinia kola extract reduced lipopolysaccharide activation of ...

    African Journals Online (AJOL)

    The effect of Garcinia kola heckel seed extract on the promonocytic cell line U937 activated by lipopolysaccharide (LPS) was investigated. 200 l of U937 cells maintained in culture at 5 x 105 cells per ml was delivered into wells of a culture plate according to groups. Cells were pre-treated with 20 l of 100 ng/ml phorbol ...

  15. Potential proliferative effect of lipopolysaccharide preconditioning on ...

    African Journals Online (AJOL)

    User

    2015-04-01

    Apr 1, 2015 ... concentrations (0.1, 0.5 and 1 µg/ml) to assess its effect on EPCs proliferation. The following genes; ... Key words: Human umbilical cord blood (hUCB), Endothelial progenitors cells (EPCs), lipopolysaccharide. (LPS), Toll-like .... detergent reagent to each well and vibration for 10 min. The absorbance (A) in ...

  16. NMR structure of temporin-1 ta in lipopolysaccharide micelles: mechanistic insight into inactivation by outer membrane.

    Directory of Open Access Journals (Sweden)

    Rathi Saravanan

    Full Text Available BACKGROUND: Antimicrobial peptides (AMPs play important roles in the innate defense mechanism. The broad spectrum of activity of AMPs requires an efficient permeabilization of the bacterial outer and inner membranes. The outer leaflet of the outer membrane of Gram negative bacteria is made of a specialized lipid called lipopolysaccharide (LPS. The LPS layer is an efficient permeability barrier against anti-bacterial agents including AMPs. As a mode of protection, LPS can induce self associations of AMPs rendering them inactive. Temporins are a group of short-sized AMPs isolated from frog skin, and many of them are inactive against Gram negative bacteria as a result of their self-association in the LPS-outer membrane. PRINCIPAL FINDINGS: Using NMR spectroscopy, we have determined atomic resolution structure and characterized localization of temporin-1Ta or TA (FLPLIGRVLSGIL-amide in LPS micelles. In LPS micelles, TA adopts helical conformation for residues L4-I12, while residues F1-L3 are found to be in extended conformations. The aromatic sidechain of residue F1 is involved in extensive packing interactions with the sidechains of residues P3, L4 and I5. Interestingly, a number of long-range NOE contacts have been detected between the N-terminal residues F1, P3 with the C-terminal residues S10, I12, L13 of TA in LPS micelles. Saturation transfer difference (STD NMR studies demonstrate close proximity of residues including F1, L2, P3, R7, S10 and L13 with the LPS micelles. Notably, the LPS bound structure of TA shows differences with the structures of TA determined in DPC and SDS detergent micelles. SIGNIFICANCE: We propose that TA, in LPS lipids, forms helical oligomeric structures employing N- and C-termini residues. Such oligomeric structures may not be translocated across the outer membrane; resulting in the inactivation of the AMP. Importantly, the results of our studies will be useful for the development of antimicrobial agents with a

  17. Synthetic LPS-Binding Polymer Nanoparticles

    Science.gov (United States)

    Jiang, Tian

    Lipopolysaccharide (LPS), one of the principal components of most gram-negative bacteria's outer membrane, is a type of contaminant that can be frequently found in recombinant DNA products. Because of its strong and even lethal biological effects, selective LPS removal from bioproducts solution is of particular importance in the pharmaceutical and health care industries. In this thesis, for the first time, a proof-of-concept study on preparing LPS-binding hydrogel-like NPs through facile one-step free-radical polymerization was presented. With the incorporation of various hydrophobic (TBAm), cationic (APM, GUA) monomers and cross-linkers (BIS, PEG), a small library of NPs was constructed. Their FITC-LPS binding behaviors were investigated and compared with those of commercially available LPS-binding products. Moreover, the LPS binding selectivity of the NPs was also explored by studying the NPs-BSA interactions. The results showed that all NPs obtained generally presented higher FITC-LPS binding capacity in lower ionic strength buffer than higher ionic strength. However, unlike commercial poly-lysine cellulose and polymyxin B agarose beads' nearly linear increase of FITC-LPS binding with particle concentration, NPs exhibited serious aggregation and the binding quickly saturated or even decreased at high particle concentration. Among various types of NPs, higher FITC-LPS binding capacity was observed for those containing more hydrophobic monomers (TBAm). However, surprisingly, more cationic NPs with higher content of APM exhibited decreased FITC-LPS binding in high ionic strength conditions. Additionally, when new cationic monomer and cross-linker, GUA and PEG, were applied to replace APM and BIS, the obtained NPs showed improved FITC-LPS binding capacity at low NP concentration. But compared with APM- and BIS-containing NPs, the FITC-LPS binding capacity of GUA- and PEG-containing NPs saturated earlier. To investigate the NPs' binding to proteins, we tested the NPs

  18. The Lipopolysaccharide Core of Brucella abortus Acts as a Shield Against Innate Immunity Recognition

    Science.gov (United States)

    Iriarte, Maite; Manček-Keber, Mateja; Barquero-Calvo, Elías; Palacios-Chaves, Leyre; Chacón-Díaz, Carlos; Chaves-Olarte, Esteban; Martirosyan, Anna; von Bargen, Kristine; Grilló, María-Jesús; Jerala, Roman; Brandenburg, Klaus; Llobet, Enrique; Bengoechea, José A.; Moreno, Edgardo

    2012-01-01

    Innate immunity recognizes bacterial molecules bearing pathogen-associated molecular patterns to launch inflammatory responses leading to the activation of adaptive immunity. However, the lipopolysaccharide (LPS) of the gram-negative bacterium Brucella lacks a marked pathogen-associated molecular pattern, and it has been postulated that this delays the development of immunity, creating a gap that is critical for the bacterium to reach the intracellular replicative niche. We found that a B. abortus mutant in the wadC gene displayed a disrupted LPS core while keeping both the LPS O-polysaccharide and lipid A. In mice, the wadC mutant induced proinflammatory responses and was attenuated. In addition, it was sensitive to killing by non-immune serum and bactericidal peptides and did not multiply in dendritic cells being targeted to lysosomal compartments. In contrast to wild type B. abortus, the wadC mutant induced dendritic cell maturation and secretion of pro-inflammatory cytokines. All these properties were reproduced by the wadC mutant purified LPS in a TLR4-dependent manner. Moreover, the core-mutated LPS displayed an increased binding to MD-2, the TLR4 co-receptor leading to subsequent increase in intracellular signaling. Here we show that Brucella escapes recognition in early stages of infection by expressing a shield against recognition by innate immunity in its LPS core and identify a novel virulence mechanism in intracellular pathogenic gram-negative bacteria. These results also encourage for an improvement in the generation of novel bacterial vaccines. PMID:22589715

  19. Lipopolysaccharide-induced neuronal activation in the paraventricular and dorsomedial hypothalamus depends on ambient temperature.

    Directory of Open Access Journals (Sweden)

    Samuel P Wanner

    Full Text Available Systemic inflammatory response syndrome is associated with either fever or hypothermia, but the mechanisms responsible for switching from one to the other are unknown. In experimental animals, systemic inflammation is often induced by bacterial lipopolysaccharide (LPS. To identify the diencephalic and brainstem structures involved in the fever-hypothermia switch, we studied the expression of c-Fos protein, a marker of neuronal activation, in rats treated with the same high dose of LPS (0.5 mg/kg, intravenously either in a thermoneutral (30 °C or cool (24 °C environment. At 30 °C, LPS caused fever; at 24 °C, the same dose caused profound hypothermia. Both fever and hypothermia were associated with the induction of c-Fos in many brain areas, including several structures of the anterior preoptic, paraventricular, lateral, and dorsal hypothalamus, the bed nucleus of the stria terminalis, the posterior pretectal nucleus, ventrolateral periaqueductal gray, lateral parabrachial nucleus, area postrema, and nucleus of the solitary tract. Every brain area studied showed a comparable response to LPS at the two different ambient temperatures used, with the exception of two areas: the dorsomedial hypothalamic nucleus (DMH, which we studied together with the adjacent dorsal hypothalamic area (DA, and the paraventricular hypothalamic nucleus (PVH. Both structures had much stronger c-Fos expression during LPS hypothermia than during fever. We propose that PVH and DMH/DA neurons are involved in a circuit, which - depending on the ambient temperature - determines whether the thermoregulatory response to bacterial LPS will be fever or hypothermia.

  20. Fluctuations in brain temperature induced by lipopolysaccharides: central and peripheral contributions.

    Science.gov (United States)

    Tang, Jeremy S; Kiyatkin, Eugene A

    2010-01-01

    In this study, we examined changes in central (anterior-preoptic hypothalamus) and peripheral (temporal muscle and facial skin) temperatures in freely moving rats following intravenous administration of bacterial lipopolysaccharides (LPS) at low doses (1 and 10 μg/kg) at thermoneutral conditions (28°C). Recordings were made with high temporal resolution (5-s bin) and the effects of LPS were compared with those induced by a tail-pinch, a standard arousing somato-sensory stimulus. At each dose, LPS moderately elevated brain, muscle, and skin temperatures. In contrast to rapid, monophasic and relatively short hyperthermic responses induced by a tail-pinch, LPS-induced increases in brain and muscle temperatures occurred with ~40 min onset latencies, showed three not clearly defined phases, were slightly larger with the 10 μm/kg dose, and maintained for the entire 4-hour post-injection recording duration. Based on dynamics of brain-muscle and skin-muscle temperature differentials, it appears that the hyperthermic response induced by LPS at the lowest dose originates from enhanced peripheral heat production, with no evidence of brain metabolic activation and skin vasoconstriction. While peripheral heat production also appears to determine the first phase of brain and body temperature elevation with LPS at 10 μg/kg, a further prolonged increase in brain-muscle differentials (onset at ~100 min) suggests metabolic brain activation as a factor contributing to brain and body hyperthermia. At this dose, skin temperature increase was weaker than in temporal muscle, suggesting vasoconstriction as another contributor to brain/body hyperthermia. Therefore, although both LPS at low doses and salient sensory stimuli moderately increase brain and body temperatures, these hyperthermic responses have important qualitative differences, reflecting unique underlying mechanisms.

  1. Identification of a novel compound that inhibits iNOS and COX-2 expression in LPS-stimulated macrophages from Schisandra chinensis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, You Jin [Department of Horticultural Bioscience, Pusan National University, Miryang 627-706 (Korea, Republic of); Park, Sun Young [Korea BIO-IT Foundry Center, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Sun Gun; Park, Da Jung; Kang, Jum Soon [Department of Horticultural Bioscience, Pusan National University, Miryang 627-706 (Korea, Republic of); Lee, Sang Joon [Department of Microbiology, Pusan National University, Busan 609-735 (Korea, Republic of); Yoon, Sik [Department of Anatomy, School of Medicine, Pusan National University, Yangsan 626-770 (Korea, Republic of); Medical Research Center for Ischemic Tissue Regeneration, School of Medicine, Pusan National University, Yangsan 626-770 (Korea, Republic of); Kim, Young Hun [Korea BIO-IT Foundry Center, Pusan National University, Busan 609-735 (Korea, Republic of); Bae, Yoe-Sik, E-mail: yoesik@dau.ac.kr [Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Choi, Young-Whan, E-mail: ywchoi@pusan.ac.kr [Department of Horticultural Bioscience, Pusan National University, Miryang 627-706 (Korea, Republic of)

    2010-01-22

    A novel {alpha}-iso-cubebenol, which has anti-inflammatory effects in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, was isolated from the fruits of Schisandra chinensis. {alpha}-iso-cubebenol inhibited LPS-induced nitric oxide (NO) and prostaglandin E{sub 2} (PGE{sub 2}) production. Consistent with these findings, {alpha}-iso-cubebenol also reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2 at the protein and mRNA levels in a concentration-dependent manner. {alpha}-iso-cubebenol also inhibited LPS-induced nuclear translocation of the NF-{kappa}B p65 subunit. Furthermore, {alpha}-iso-cubebenol suppressed the phosphorylation of ERK, JNK, and p38 kinase induced by LPS. Since the novel {alpha}-iso-cubebenol blocked the production of several pro-inflammatory mediators induced by LPS in macrophages, the molecule can be useful material for the development of anti-inflammatory agents against bacterial infections or endotoxin.

  2. Isolation of prawn ( Exopalaemon carinicauda) lipopolysaccharide and β-1, 3-glucan binding protein gene and its expression in responding to bacterial and viral infections

    Science.gov (United States)

    Ge, Qianqian; Li, Jian; Duan, Yafei; Li, Jitao; Sun, Ming; Zhao, Fazhen

    2016-04-01

    The pattern recognition proteins (PRPs) play a major role in immune response of crustacean to resist pathogens. In the present study, as one of PRPs, lipopolysaccharide and β-1, 3-glucan binding protein (LGBP) gene in the ridge tail white prawn ( Exopalaemon carinicauda) ( EcLGBP) was isolated. The full-length cDNA of EcLGBP was 1338 bp, encoding a polypeptide of 366 amino acid residules. The deduced amino acid sequence of EcLGBP shared high similarities with LGBP and BGBP from other crustaceans. Some conservative domains were predicted in EcLGBP sequence. EcLGBP constitutively expressed in most tissues at different levels, and the highest expression was observed in hepatopancreas. With infection time, the cumulative mortality increased gradually followed by the proliferation of Vibrio parahaemolyticus and white spot syndrome virus (WSSV). The expression of EcLGBP in response to V. parahaemolyticus infection was up-regulated in hemocytes and hepatopancreas, and the up-regulation in hepatopancreas was earlier than that in hemocytes. EcLGBP expression after WSSV infection increased at 3 h, then significantly decreased in both hemocytes and hepatopancreas. The results indicated that EcLGBP was involved in the immune defense against bacterial and viral infections.

  3. Expression pattern of inflammatory response genes and their regulatory micrornas in bovine oviductal cells in response to lipopolysaccharide: implication for early embryonic development.

    Directory of Open Access Journals (Sweden)

    Sally Ibrahim

    Full Text Available In the present study, we used an in vitro model to investigate the response of the oviduct with respect to inflammatory mediators and their regulatory microRNAs in case of bacterial infection and subsequent association with embryo survival. For this, we conducted two experiments. In the first experiment, cultured primary bovine oviductal cells (BOEC were challenged with lipopolysaccharide (LPS for 24h and the temporal expression pattern of inflammatory mediators and their regulatory microRNAs were measured at 0, 3, 6, 12, 24 and 48h after LPS treatment. Intriguingly, the temporal patterns of all miRNAs except miR-21 were significantly up-regulated at 6h after LPS treatment. Whereas, we observed significant overexpression of pro-inflammatory mediators as tumor necrosis factor alpha (TNFα and interleukin-1 beta (IL1β after LPS challenge for 24h. On the other hand, the expression level of essential elements like oviductal glycoprotein 1 (OVGP1 and insulin-like growth factor 2 (IGF2 was significantly decreased in challenged groups compared with control. Moreover, miR-155, miR-146a, miR-223, miR-21, miR-16 and miR-215 have shown a clear suppression in challenged group after LPS treatment. In the 2nd experiment there were four groups of blastocysts produced, namely embryo+LPS free media, embryo+LPS, BOEC+embryo and BOEC+embryo+LPS. The suboptimal oviduct environment due to LPS challenge is found to have a significant influence on the expression of inflammatory response genes (TNFα and CSF1, stress response genes (SOD and CAT, mitochondrial activity, reactive oxygen species (ROS accumulation and apoptotic level either in cultured or co-cultured blastocysts. Collectively, LPS challenge led to aberrant changes in oviductal transcriptome profile, which could lead to a suboptimal environment for embryo development.

  4. Spirulina lipopolysaccharides inhibit tumor growth in a Toll-like receptor 4-dependent manner by altering the cytokine milieu from interleukin-17/interleukin-23 to interferon-γ.

    Science.gov (United States)

    Okuyama, Hiromi; Tominaga, Akira; Fukuoka, Satoshi; Taguchi, Takahiro; Kusumoto, Yutaka; Ono, Shiro

    2017-02-01

    Th17 cells and the cytokine they produce, interleukin (IL)-17, play an important role in tumor progression in humans and in mice. IL-6 and IL-23 are critical cytokines for the differentiation and propagation of Th17 cells, respectively. Bacterial lipopolysaccharides (LPS) are known to stimulate immune cells to produce such inflammatory cytokines. Contrary to Escherichia coli (E. coli) LPS, LPS from Spirulina has low toxicity and barely induces in vivo production of IL-6 and IL-23 in mice. We examined the antitumor effects of Spirulina LPS compared to E. coli LPS in an MH134 hepatoma model. Administration of Spirulina LPS suppressed tumor growth in C3H/HeN mice, but not in Toll-like receptor 4 (TLR4)-mutant C3H/HeJ mice, by reducing serum levels of IL-17 and IL-23, while increasing interferon (IFN)-γ levels. The antitumor activity and IFN-γ production were mediated by T cells. Moreover, in vitro experiments showed that Spirulina LPS impaired the antigen-presenting function that supports the generation of IL-17-producing cells in a toll-like receptor (TLR)4-dependent manner. Of note, injection of anti-IL-17 antibody in tumor-bearing C3H/HeN mice in the absence of Spirulina LPS markedly suppressed tumor growth and augmented IFN-γ responses. Thus, our results support the notion that IFN-γ and IL-17/IL-23 mutually regulate Th17 and Th1 responses in tumor-bearing hosts, and Spirulina LPS modulates the balance of the IFN-γ-IL-17/IL-23 axis towards IFN-γ production, which leads to tumor inhibition. Furthermore, Spirulina LPS effectively inhibited the spontaneous development of mammary tumors. This study has important implications for the exploitation of TLR-based immunomodulators for cancer immunotherapy.

  5. Colistin-Resistant, Lipopolysaccharide-Deficient Acinetobacter baumannii Responds to Lipopolysaccharide Loss through Increased Expression of Genes Involved in the Synthesis and Transport of Lipoproteins, Phospholipids, and Poly-β-1,6-N-Acetylglucosamine

    Science.gov (United States)

    Henry, Rebekah; Vithanage, Nuwan; Harrison, Paul; Seemann, Torsten; Coutts, Scott; Moffatt, Jennifer H.; Nation, Roger L.; Li, Jian; Harper, Marina; Adler, Ben

    2012-01-01

    We recently demonstrated that colistin resistance in Acinetobacter baumannii can result from mutational inactivation of genes essential for lipid A biosynthesis (Moffatt JH, et al., Antimicrob. Agents Chemother. 54:4971–4977). Consequently, strains harboring these mutations are unable to produce the major Gram-negative bacterial surface component, lipopolysaccharide (LPS). To understand how A. baumannii compensates for the lack of LPS, we compared the transcriptional profile of the A. baumannii type strain ATCC 19606 to that of an isogenic, LPS-deficient, lpxA mutant strain. The analysis of the expression profiles indicated that the LPS-deficient strain showed increased expression of many genes involved in cell envelope and membrane biogenesis. In particular, upregulated genes included those involved in the Lol lipoprotein transport system and the Mla-retrograde phospholipid transport system. In addition, genes involved in the synthesis and transport of poly-β-1,6-N-acetylglucosamine (PNAG) also were upregulated, and a corresponding increase in PNAG production was observed. The LPS-deficient strain also exhibited the reduced expression of genes predicted to encode the fimbrial subunit FimA and a type VI secretion system (T6SS). The reduced expression of genes involved in T6SS correlated with the detection of the T6SS-effector protein AssC in culture supernatants of the A. baumannii wild-type strain but not in the LPS-deficient strain. Taken together, these data show that, in response to total LPS loss, A. baumannii alters the expression of critical transport and biosynthesis systems associated with modulating the composition and structure of the bacterial surface. PMID:22024825

  6. Colistin-resistant, lipopolysaccharide-deficient Acinetobacter baumannii responds to lipopolysaccharide loss through increased expression of genes involved in the synthesis and transport of lipoproteins, phospholipids, and poly-β-1,6-N-acetylglucosamine.

    Science.gov (United States)

    Henry, Rebekah; Vithanage, Nuwan; Harrison, Paul; Seemann, Torsten; Coutts, Scott; Moffatt, Jennifer H; Nation, Roger L; Li, Jian; Harper, Marina; Adler, Ben; Boyce, John D

    2012-01-01

    We recently demonstrated that colistin resistance in Acinetobacter baumannii can result from mutational inactivation of genes essential for lipid A biosynthesis (Moffatt JH, et al., Antimicrob. Agents Chemother. 54:4971-4977). Consequently, strains harboring these mutations are unable to produce the major Gram-negative bacterial surface component, lipopolysaccharide (LPS). To understand how A. baumannii compensates for the lack of LPS, we compared the transcriptional profile of the A. baumannii type strain ATCC 19606 to that of an isogenic, LPS-deficient, lpxA mutant strain. The analysis of the expression profiles indicated that the LPS-deficient strain showed increased expression of many genes involved in cell envelope and membrane biogenesis. In particular, upregulated genes included those involved in the Lol lipoprotein transport system and the Mla-retrograde phospholipid transport system. In addition, genes involved in the synthesis and transport of poly-β-1,6-N-acetylglucosamine (PNAG) also were upregulated, and a corresponding increase in PNAG production was observed. The LPS-deficient strain also exhibited the reduced expression of genes predicted to encode the fimbrial subunit FimA and a type VI secretion system (T6SS). The reduced expression of genes involved in T6SS correlated with the detection of the T6SS-effector protein AssC in culture supernatants of the A. baumannii wild-type strain but not in the LPS-deficient strain. Taken together, these data show that, in response to total LPS loss, A. baumannii alters the expression of critical transport and biosynthesis systems associated with modulating the composition and structure of the bacterial surface.

  7. Administration of LPS three times during gestation alters the postnatal acute phase and metabolic responses to an LPS challenge in weaned beef heifers

    Science.gov (United States)

    This study evaluated whether three administrations of lipopolysaccharide (LPS) during gestation would alter the acute phase (APR) and metabolic responses to a postnatal LPS challenge in weaned heifers. Pregnant crossbred cows (n=50) were randomized into prenatal immune stimulation (PIS; n=24; admini...

  8. Long-term nicotine exposure dampens LPS-induced nerve-mediated airway hyperreactivity in murine airways.

    Science.gov (United States)

    Xu, Yuan; Cardell, Lars-Olaf

    2017-09-01

    Nicotine is a major component of cigarette smoke. It causes addiction and is used clinically to aid smoke cessation. The aim of the present study is to investigate the effect of nicotine on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and to explore the potential involvement of neuronal mechanisms behind nicotine's effects in murine models in vivo and in vitro. BALB/c mice were exposed to nicotine in vivo via subcutaneous Alzet osmotic minipumps containing nicotine tartate salt solution (24 mg·kg -1 ·day -1 ) for 28 days. LPS (0.1 mg/ml, 20 µl) was administered intranasally for 3 consecutive days during the end of this period. Lung functions were measured with flexiVent. For the in vitro experiments, mice tracheae were organcultured with either nicotine (10 μM) or vehicle (DMSO, 0.1%) for 4 days. Contractile responses of the tracheal segments were measured in myographs following electric field stimulation (EFS; increasing frequencies of 0.2 to 12.8 Hz) before and after incubation with 10 µg/ml LPS for 1 h. Results showed that LPS induced AHR to methacholine in vivo and increased contractile responses to EFS in vitro. Interestingly, long-term nicotine exposure markedly dampened this LPS-induced AHR both in vitro and in vivo. Tetrodotoxin (TTX) inhibited LPS-induced AHR but did not further inhibit nicotine-suppressed AHR in vivo. In conclusion, long-term nicotine exposure dampened LPS-induced AHR. The effect of nicotine was mimicked by TTX, suggesting the involvement of neuronal mechanisms. This information might be used for evaluating the long-term effects of nicotine and further exploring of how tobacco products interact with bacterial airway infections. Copyright © 2017 the American Physiological Society.

  9. In vitro determination of the antibiotic susceptibility of biofilm-forming Pseudomonas aeruginosa and Staphylococcus aureus: possible role of proteolytic activity and membrane lipopolysaccharide.

    Science.gov (United States)

    Masadeh, Majed M; Mhaidat, Nizar M; Alzoubi, Karem H; Hussein, Emad I; Al-Trad, Esra'a I

    2013-01-01

    We carried out a comprehensive overview of inhibitory effects of selected antibiotics on planktonic and biofilm cells of Staphylococcus aureus (ATCC 29213) and Pseudomonas aeruginosa (ATCC 27853) strains. The possible involvement of protease activity and the lipopolysaccharide (LPS) profile of P. aeruginosa were also analyzed. Biofilm cells of both strains were more resistant to antibiotics than their planktonic counterparts. Protease activity was increased in both strains in the biofilm forms. Challenge with sublethal doses of antibiotics also increased proteolytic activity of biofilm cells. Additionally, the LPS profile of P. aeruginosa showed pattern alterations of the biofilm that can contribute to biofilm resistance and survival. These observations provide evidence for the involvement of bacterial proteolytic activity and LPS profile in the resistance of biofilm bacteria to antibiotics compared to their planktonic counterparts.

  10. Lipopolysaccharide induces proliferation and osteogenic differentiation of adipose-derived mesenchymal stromal cells in vitro via TLR4 activation

    Energy Technology Data Exchange (ETDEWEB)

    Herzmann, Nicole; Salamon, Achim [Department of Cell Biology, University Medicine Rostock, Schillingallee 69, D-18057 Rostock (Germany); Fiedler, Tomas [Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Schillingallee 70, D-18057 Rostock (Germany); Peters, Kirsten, E-mail: kirsten.peters@med.uni-rostock.de [Department of Cell Biology, University Medicine Rostock, Schillingallee 69, D-18057 Rostock (Germany)

    2017-01-01

    Multipotent mesenchymal stromal cells (MSC) are capable of multi-lineage differentiation and support regenerative processes. In bacterial infections, resident MSC can come intocontact with and need to react to bacterial components. Lipopolysaccharide (LPS), a typical structure of Gram-negative bacteria, increases the proliferation and osteogenic differentiation of MSC. LPS is usually recognized by the toll-like receptor (TLR) 4 and induces pro-inflammatory reactions in numerous cell types. In this study, we quantified the protein expression of TLR4 and CD14 on adipose-derived MSC (adMSC) in osteogenic differentiation and investigated the effect of TLR4 activation by LPS on NF-κB activation, proliferation and osteogenic differentiation of adMSC. We found that TLR4 is expressed on adMSC whereas CD14 is not, and that osteogenic differentiation induced an increase of the amount of TLR4 protein whereas LPS stimulation did not. Moreover, we could show that NF-κB activation via TLR4 occurs upon LPS treatment. Furthermore, we were able to show that competitive inhibition of TLR4 completely abolished the stimulatory effect of LPS on the proliferation and osteogenic differentiation of adMSC. In addition, the inhibition of TLR4 leads to the complete absence of osteogenic differentiation of adMSC, even when osteogenically stimulated. Thus, we conclude that LPS induces proliferation and osteogenic differentiation of adMSC in vitro through the activation of TLR4 and that the TLR4 receptor seems to play a role during osteogenic differentiation of adMSC.

  11. Toll-Like Receptor 4 Decoy, TOY, Attenuates Gram-Negative Bacterial Sepsis

    OpenAIRE

    Jung, Keehoon; Lee, Jung-Eun; Kim, Hak-Zoo; Kim, Ho Min; Park, Beom Seok; Hwang, Seong-Ik; Lee, Jie-Oh; Kim, Sun Chang; Koh, Gou Young

    2009-01-01

    Lipopolysaccharide (LPS), the Gram-negative bacterial outer membrane glycolipid, induces sepsis through its interaction with myeloid differentiation protein-2 (MD-2) and Toll-like receptor 4 (TLR4). To block interaction between LPS/MD-2 complex and TLR4, we designed and generated soluble fusion proteins capable of binding MD-2, dubbed TLR4 decoy receptor (TOY) using 'the Hybrid leucine-rich repeats (LRR) technique'. TOY contains the MD-2 binding ectodomain of TLR4, the LRR motif of hagfish va...

  12. Lipopolysaccharide and cytokines inhibit rat cardiomyocyte contractility in vitro.

    Science.gov (United States)

    Hobai, Ion A; Morse, Justin C; Siwik, Deborah A; Colucci, Wilson S

    2015-02-01

    Sepsis-induced cardiomyopathy (SIC) is thought to be the result of detrimental effects of inflammatory mediators on the cardiac muscle. Here we studied the effects of prolonged (24 ± 4 h) exposure of adult rat ventricular myocytes (ARVM) to bacterial lipopolysaccharide (LPS) and inflammatory cytokines tumor necrosis factor (TNF) and interleukins-1 (IL-1) and IL-6. We measured sarcomere shortening (SS) and cellular calcium (Ca(2+)) transients (ΔCai, with fura-2 AM) in isolated cardiomyocytes externally paced at 5 Hz at 37°C. SS decreased after incubation with LPS (100 μg/mL), IL-1 (100 ng/mL), and IL-6 (30 ng/mL), but not with lesser doses of these mediators, or TNF (10-100 ng/mL). A combination of LPS (100 μg/mL), TNF, IL-1, and IL-6 (each 100 ng/mL; i.e., "Cytomix-100") induced a maximal decrease in SS and ΔCai. Sarcoplasmic reticulum (SR) Ca(2+) load (CaSR, measured with caffeine) was unchanged by Cytomix-100; however, SR fractional release (ΔCai/CaSR) was decreased. Underlying these effects, Ca(2+) influx into the cell (via L-type Ca(2+) channels, LTCC) and Ca(2+) extrusion via Na(+)/Ca(2+) exchange were decreased by Cytomix-100. SR Ca(2+) pump (SERCA) (SR Ca(2+) ATPase) was not affected. Prolonged exposure of ARVM to a mixture of LPS and inflammatory cytokines inhibits cell contractility. The effect is mediated by the inhibition of Ca(2+) influx via LTCC, and partially opposed by the inhibition of Na(+)/Ca(2+) exchange. Because both mechanisms are commonly seen in animal models of SIC, we conclude that prolonged challenge with Cytomix-100 of ARVM may represent an accurate in vitro model for SIC. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Enterobacter agglomerans lipopolysaccharide-induced changes in pulmonary surfactant as a factor in the pathogenesis of byssinosis.

    Science.gov (United States)

    DeLucca, A J; Brogden, K A; Engen, R

    1988-04-01

    Lipopolysaccharide (LPS) from Enterobacter agglomerans and pulmonary surfactant mixtures were centrifuged in discontinuous sucrose gradients to determine whether LPS bound to surfactant and examined in a Langmuir trough with a Wilhelmy balance to determine whether LPS altered the surface activity of surfactant. The LPS was found to bind to the surfactant and altered its surface tension properties. The binding of LPS to surfactant in the lung may change the physiological properties of surfactant and be a possible mechanism for the pathogenesis of byssinosis.

  14. Vulnerability of vascular endothelium in lipopolysaccharide toxicity: effect of (acyl carnitine on endothelial stability

    Directory of Open Access Journals (Sweden)

    W. C. Hülsmann

    1993-01-01

    Full Text Available The literature presented illustrates that lipopolysaccharide (LPS, from bacterial cell walls, induces tumour necrosis factor (TNF synthesis in macrophages. TNF affects a number of cell types, amongst which are endothelial cells, within a few hours. Its injection has been shown to produce all symptoms of the toxic syndrome. In the present communication the vulnerability of endothelial cells will be stressed. These cells require carnitine not only for fatty acid oxidation but also for membrane protection and repair. As endothelial cells lose carnitine during hypoperfusion, it is speculated that the supply of carnitine during the early phase of LPS toxicity in rats might delay or avoid loss of endothelial functions. Earlier it was observed that hearts from rats, injected 3 h previously with LPS, showed strongly increased interstitial fluid production compared to hearts from control rats, even when TNF was present during a 3 h in vitro perfusion. It showed that LPS in vivo generates factors other than TNF, such as platelet activating factor (PAF, that are responsible for the increased capillary permeability.

  15. Omega-3 Fatty Acid Intervention Suppresses Lipopolysaccharide-Induced Inflammation and Weight Loss in Mice

    Directory of Open Access Journals (Sweden)

    Ying-Hua Liu

    2015-02-01

    Full Text Available Bacterial endotoxin lipopolysaccharide (LPS-induced sepsis is a critical medical condition, characterized by a severe systemic inflammation and rapid loss of muscle mass. Preventive and therapeutic strategies for this complex disease are still lacking. Here, we evaluated the effect of omega-3 (n-3 polyunsaturated fatty acid (PUFA intervention on LPS-challenged mice with respect to inflammation, body weight and the expression of Toll-like receptor 4 (TLR4 pathway components. LPS administration induced a dramatic loss of body weight within two days. Treatment with n-3 PUFA not only stopped loss of body weight but also gradually reversed it back to baseline levels within one week. Accordingly, the animals treated with n-3 PUFA exhibited markedly lower levels of inflammatory cytokines or markers in plasma and tissues, as well as down-regulation of TLR4 pathway components compared to animals without n-3 PUFA treatment or those treated with omega-6 PUFA. Our data demonstrate that n-3 PUFA intervention can suppress LPS-induced inflammation and weight loss via, at least in part, down-regulation of pro-inflammatory targets of the TLR4 signaling pathway, and highlight the therapeutic potential of n-3 PUFA in the management of sepsis.

  16. Primed Activation of Macrophages by Oral Administration of Lipopolysaccharide Derived from Pantoea agglomerans.

    Science.gov (United States)

    Inagawa, Hiroyuki; Kobayashi, Yutaro; Kohchi, Chie; Zhang, Ran; Shibasaki, Yasuhiro; Soma, Gen-Ichiro

    2016-01-01

    Bacterial lipopolysaccharide (LPS) is involved in the activation of the innate immune responses on monocytes/macrophages in vitro, and by intravenous injection. Although small quantities of LPS are usually found in traditional Chinese medicines, vegetables and fruits, the mode of action of orally administered LPS is still unclear. LPS derived from Pantoea agglomerans (LPSp) was orally administered to C3H/HeN or C3H/HeJ mice ad libitum. The LPSp treatment enhanced phagocytosis by resident peritoneal macrophages of C3H/HeN mice but not of C3H/HeJ mice. This activation can be defined as primed activation because no augmentation of inflammatory cytokines production was detected. LPSp in peritoneal fluid was detected and successfully quantified. Moreover, the LPSp reduced the expression of avian reticuloendotheliosis viral oncogene-related B (RelB) in the macrophages without degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cell inhibitor, alpha (IκBα). Orally administered LPSp can reach the peritoneum, and enhance phagocytosis via Toll-like receptor 4 signaling pathway in resident peritoneal macrophages. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  17. Lipopolysaccharides from Commensal and Opportunistic Bacteria: Characterization and Response of the Immune System of the Host Sponge Suberites domuncula

    Directory of Open Access Journals (Sweden)

    Johan Gardères

    2015-08-01

    Full Text Available Marine sponges harbor a rich bacterioflora with which they maintain close relationships. However, the way these animals make the distinction between bacteria which are consumed to meet their metabolic needs and opportunistic and commensal bacteria which are hosted is not elucidated. Among the elements participating in this discrimination, bacterial cell wall components such as lipopolysaccharides (LPS could play a role. In the present study, we investigated the LPS chemical structure of two bacteria associated with the sponge Suberites domuncula: a commensal Endozoicomonas sp. and an opportunistic Pseudoalteromonas sp. Electrophoretic patterns indicated different LPS structures for these bacteria. The immunomodulatory lipid A was isolated after mild acetic acid hydrolysis. The electrospray ionization ion-trap mass spectra revealed monophosphorylated molecules corresponding to tetra- and pentaacylated structures with common structural features between the two strains. Despite peculiar structural characteristics, none of these two LPS influenced the expression of the macrophage-expressed gene S. domuncula unlike the Escherichia coli ones. Further research will have to include a larger number of genes to understand how this animal can distinguish between LPS with resembling structures and discriminate between bacteria associated with it.

  18. Inhibitory effects of a super pulsed carbon dioxide laser at low energy density on periodontopathic bacteria and lipopolysaccharide in vitro.

    Science.gov (United States)

    Kojima, Taro; Shimada, Koichi; Iwasaki, Hiroyasu; Ito, Koichi

    2005-12-01

    Previous studies have described the effect of irradiation by a carbon dioxide (CO2) laser at high energy density on oral bacteria, and various side-effects have also been observed. However, no published studies have examined the effect of irradiation by a CO2 laser at low energy density on oral bacteria. The purpose of this study was to investigate the effects of super pulsed CO2 laser irradiation on periodontopathic bacteria and lipopolysaccharide (LPS). Bacterial suspensions of two species of periodontopathic bacteria received laser irradiation at energy densities of 0-12.5 J/cm2. The suspensions were then spread over agar plates and incubated anaerobically. The bactericidal effects were evaluated based on colony formation. Samples of LPS were laser-irradiated at energy densities of 0-12.5 J/cm2. The biological activity was measured, and LPS was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The irradiation at low energy densities of 7.5 and 12.5 J/cm2 killed more than 99.9 and 99.999% of Porphyromonas gingivalis and more than 99% of Actinobacillus actinomycetemcomitans was sterilized by the irradiation at 7.5 J/cm2. LPS biological activity was significantly decreased by laser irradiation at energy densities of more than 7.5 J/cm2 (p CO2 laser irradiation at low power is capable of bactericidal effect on periodontopathic bacteria and decreasing LPS activity.

  19. Bee Venom Inhibits Porphyromonas gingivalis Lipopolysaccharides-Induced Pro-Inflammatory Cytokines through Suppression of NF-κB and AP-1 Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Woon-Hae Kim

    2016-11-01

    Full Text Available Periodontitis is a chronic inflammatory disease that leads to destruction of tooth supporting tissues. Porphyromonas gingivalis (P. gingivalis, especially its lipopolysaccharides (LPS, is one of major pathogens that cause periodontitis. Bee venom (BV has been widely used as a traditional medicine for various diseases. Previous studies have demonstrated the anti-inflammatory, anti-bacterial effects of BV. However, a direct role and cellular mechanism of BV on periodontitis-like human keratinocytes have not been explored. Therefore, we investigated the anti-inflammatory mechanism of BV against P. gingivalis LPS (PgLPS-induced HaCaT human keratinocyte cell line. The anti-inflammatory effect of BV was demonstrated by various molecular biological methods. The results showed that PgLPS increased the expression of Toll-like receptor (TLR-4 and pro-inflammatory cytokines, such as tumor necrosis factor (TNF-α, interleukin (IL-1β, IL-6, IL-8, and interferon (IFN-γ. In addition, PgLPS induced activation of the signaling pathways of inflammatory cytokines-related transcription factors, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and activator protein 1 (AP-1. BV effectively inhibited those pro-inflammatory cytokines through suppression of NF-κB and AP-1 signaling pathways. These results suggest that administration of BV attenuates PgLPS-induced inflammatory responses. Furthermore, BV may be a useful treatment to anti-inflammatory therapy for periodontitis.

  20. In Vivo Molecular Responses of Fast and Slow Muscle Fibers to Lipopolysaccharide in a Teleost Fish, the Rainbow Trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Leonardo J. Magnoni

    2015-02-01

    Full Text Available The physiological consequences of the activation of the immune system in skeletal muscle in fish are not completely understood. To study the consequences of the activation of the immune system by bacterial pathogens on skeletal muscle function, we administered lipopolysaccharide (LPS, an active component of Gram-negative bacteria, in rainbow trout and performed transcriptomic and proteomic analyses in skeletal muscle. We examined changes in gene expression in fast and slow skeletal muscle in rainbow trout at 24 and 72 h after LPS treatment (8 mg/kg by microarray analysis. At the transcriptional level, we observed important changes in metabolic, mitochondrial and structural genes in fast and slow skeletal muscle. In slow skeletal muscle, LPS caused marked changes in the expression of genes related to oxidative phosphorylation, while in fast skeletal muscle LPS administration caused major changes in the expression of genes coding for glycolytic enzymes. We also evaluated the effects of LPS administration on the fast skeletal muscle proteome and identified 14 proteins that were differentially induced in LPS-treated trout, primarily corresponding to glycolytic enzymes. Our results evidence a robust and tissue-specific response of skeletal muscle to an acute inflammatory challenge, affecting energy utilization and possibly growth in rainbow trout.

  1. Bee Venom Inhibits Porphyromonas gingivalis Lipopolysaccharides-Induced Pro-Inflammatory Cytokines through Suppression of NF-κB and AP-1 Signaling Pathways.

    Science.gov (United States)

    Kim, Woon-Hae; An, Hyun-Jin; Kim, Jung-Yeon; Gwon, Mi-Gyeong; Gu, Hyemin; Park, Jae-Bok; Sung, Woo Jung; Kwon, Yong-Chul; Park, Kyung-Duck; Han, Sang Mi; Park, Kwan-Kyu

    2016-11-10

    Periodontitis is a chronic inflammatory disease that leads to destruction of tooth supporting tissues. Porphyromonas gingivalis ( P. gingivalis ), especially its lipopolysaccharides (LPS), is one of major pathogens that cause periodontitis. Bee venom (BV) has been widely used as a traditional medicine for various diseases. Previous studies have demonstrated the anti-inflammatory, anti-bacterial effects of BV. However, a direct role and cellular mechanism of BV on periodontitis-like human keratinocytes have not been explored. Therefore, we investigated the anti-inflammatory mechanism of BV against P. gingivalis LPS (PgLPS)-induced HaCaT human keratinocyte cell line. The anti-inflammatory effect of BV was demonstrated by various molecular biological methods. The results showed that PgLPS increased the expression of Toll-like receptor (TLR)-4 and pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, and interferon (IFN)-γ. In addition, PgLPS induced activation of the signaling pathways of inflammatory cytokines-related transcription factors, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein 1 (AP-1). BV effectively inhibited those pro-inflammatory cytokines through suppression of NF-κB and AP-1 signaling pathways. These results suggest that administration of BV attenuates PgLPS-induced inflammatory responses. Furthermore, BV may be a useful treatment to anti-inflammatory therapy for periodontitis.

  2. Lipopolysaccharide-induced biliary factors enhance invasion of Salmonella enteritidis in a rat model.

    Science.gov (United States)

    Islam, A F; Moss, N D; Dai, Y; Smith, M S; Collins, A M; Jackson, G D

    2000-01-01

    In this study, the role of the hepatobiliary system in the early pathogenesis of Salmonella enteritidis infection was investigated in a rat model. Intravenous (i.v.) challenge with lipopolysaccharide (LPS) has previously been shown to enhance the translocation of normal gut flora. We first confirmed that LPS can similarly promote the invasion of S. enteritidis. Oral infection of outbred Australian Albino Wistar rats with 10(6) to 10(7) CFU of S. enteritidis led to widespread tissue invasion after days. If animals were similarly challenged after intravenous administration of S. enteritidis LPS (3 to 900 microg/kg of body weight), significant invasion of the livers and mesenteric lymph nodes (MLN) occurred within 24 h, with invasion of the liver increasing in a dose-dependent fashion (P < 0.01). If bile was prevented from reaching the intestine by bile duct ligation or cannulation, bacterial invasion of the liver and MLN was almost totally abrogated (P < 0.001). As i.v. challenge with LPS could induce the delivery of inflammatory mediators into the bile, biliary tumor necrosis factor alpha (TNF-alpha) concentrations were measured by bioassay. Biliary concentrations of TNF-alpha rose shortly after LPS challenge, peaked with a mean concentration of 27.0 ng/ml at around 1 h postchallenge, and returned to baseline levels (3.1 ng/ml) after 2.5 h. Although TNF-alpha cannot be directly implicated in the invasion process, we conclude that the invasiveness of the enteric pathogen S. enteritidis is enhanced by the presence of LPS in the blood and that this enhanced invasion is at least in part a consequence of the delivery of inflammatory mediators to the gastrointestinal tract by the hepatobiliary system.

  3. Gut microbiota-derived lipopolysaccharide uptake and trafficking to adipose tissue

    DEFF Research Database (Denmark)

    Hersoug, L-G.; Møller, Peter; Loft, Steffen

    2016-01-01

    , low-grade inflammation, expression of fat translocase and scavenger receptor CD36, and the scavenger receptor class B type 1 (SR-BI). SR-BI binds to both lipids and lipopolysaccharide (LPS) from Gram-negative bacteria, which may promote incorporation of LPS in chylomicrons (CMs). These CMs...... activity absorb LPS-rich lipoproteins. In addition, macrophages in adipose tissue internalize LPS-lipoproteins. This may contribute to the polarization from M2 to M1 phenotype, which is a consequence of increased LPS delivery into the tissue during hypertrophy. In conclusion, evidence suggests that LPS...

  4. [Characterization of Pantoea agglomerans lipopolysaccharides].

    Science.gov (United States)

    Varbanets, L D; Brovarskaya, O S; Bulygina, T N; Garkavaya, E G; Zhitkevich, N V

    2014-01-01

    Lipopolysaccharides (LPS) from seven Pantoea agglomerans strains isolated from various plants were purified and chemically identified. LPS of the studied P. agglomerans strains were heterogeneous in monosaccharide composition. Thus, the LPS of P. agglomerans 8606 differed considerably from the LPSs of other strains, containing mannose as the predominant monosaccharide (69.8%), as well as ribose (15.1%) and xylose (12.6%), while the content of rhamnose, one of the predominant monosaccharides in other LPS samples, was 2.5%. Analysis of the fatty acid composition revealed the presence of C12-C16 acids. In lipids A of all the studied strains, 3-OH-C14:0 was the predominant acid (31.7 to 39.1%, depending on the strain). C12:0 (8.2 to 31.5%), C14:0 (12.9 to 30.8%), and C16:0 acids (3.4 to 16.9%) were also revealed. The studied P. agglomerans strains fell into three groups according to their fatty acid composition. The differences stemmed from the presence or absence of two fatty acids, 2-OH-C14:0 and C16:1. Ouchterlony double immunodiffusion in agar revealed that all the LPS under study exhibited antigenic activity in homologous systems. The results of serological cross reactions indicated immunochemical heterogeneity of the species P. agglomerans. Comparative investigation of the complex of parameters of peripheral blood cells from a healthy donor before and after treatment with LPS solutions showed that the values of no parameters exceeded the normal range.

  5. Concentration Dependent Influence of Lipopolysaccharides on Separation of Hoof Explants and Supernatant Lactic Acid Concentration in an Ex Vivo/In Vitro Laminitis Model.

    Directory of Open Access Journals (Sweden)

    Nicole Reisinger

    Full Text Available Laminitis is one of the most common diseases in horses. It is not only painful for the animal, but also has a significant financial impact on the equine industry. This multifactorial disease affects the connective tissue of the hoof. However, the pathogenesis of laminitis is still not fully understood. Endotoxins, also known as lipopolysaccharides (LPS, and bacterial exotoxins seem to play an important role during the development of laminitis. The aim of our study was to investigate the effect of increasing LPS concentrations (0, 2.5, 5, 10, and 100 μg/mL on cell viability of isolated epidermal and dermal hoof cells as well as on the tissue integrity of hoof explants. Furthermore, glucose, acetic acid, lactic acid, and propionic acid concentrations in explant supernatants were measured to evaluate the energy metabolism in the hoof tissue. LPS did not exhibit cytotoxic effects on epidermal or dermal cells. Force required to separate LPS treated hoof explants decreased in a concentration dependent manner. Specifically, explants incubated with 10 and 100 μg/mL needed significantly less force to separate compared to control explants. Lactic acid concentrations were significantly decreased in explants incubated with 5, 10, or 100 μg/mL LPS, while glucose, acetic acid and propionic acid concentrations were unaffected by LPS treatment. Our study indicates that LPS has no cytotoxic effect on epidermal and dermal cells isolated from hoof tissue, but impairs integrity of hoof explants. In addition, LPS led to an alteration of the lactic acid production in the lamellar tissue. Since our data highlight that LPS can affect the integrity of the equine hoof tissue in vitro, endotoxins should be further explored for their contribution to facilitate the development of laminitis.

  6. Importance of Antibodies to Lipopolysaccharide in Natural and Vaccine-Induced Serum Bactericidal Activity against Neisseria meningitidis Group B▿†

    Science.gov (United States)

    Schmiel, Deborah H.; Moran, Elizabeth E.; Keiser, Paul B.; Brandt, Brenda L.; Zollinger, Wendell D.

    2011-01-01

    Analysis of the specificity of bactericidal antibodies in normal, convalescent, and postvaccination human sera is important in understanding human immunity to meningococcal infections and can aid in the design of an effective group B vaccine. A collection of human sera, including group C and group B convalescent-phase sera, normal sera with naturally occurring cross-reactive bactericidal activity, and some postvaccination sera, was analyzed to determine the specificity of cross-reactive bactericidal antibodies. Analysis of human sera using a bactericidal antibody depletion assay demonstrated that a significant portion of the bactericidal activity could be removed by purified lipopolysaccharide (LPS). LPS homologous to that expressed on the bactericidal test strain was most effective, but partial depletion by heterologous LPS suggested the presence of antibodies with various degrees of cross-reactivity. Binding of anti-L3,7 LPS bactericidal antibodies was affected by modification of the core structure, suggesting that these functional antibodies recognized epitopes consisting of both core structures and lacto-N-neotetraose (LNnT). When the target strain was grown with 5′-cytidinemonophospho-N-acetylneuraminic acid (CMP-NANA) to increase LPS sialylation, convalescent-phase serum bactericidal titers were decreased by only 2- to 4-fold, and most remaining bactericidal activity was still depleted by LPS. Highly sialylated LPS was ineffective in depleting bactericidal antibodies. We conclude that natural infections caused by strains expressing L3,7 LPS induce persistent, protective bactericidal antibodies and appear to be directed against nonsialylated bacterial epitopes. Additionally, subsets of these bactericidal antibodies are cross-reactive, binding to several different LPS immunotypes, which is a useful characteristic for an effective group B meningococcal vaccine antigen. PMID:21768280

  7. Serum Levels of Lipopolysaccharide and 1,3-β-D-Glucan Refer to the Severity in Patients with Crohn’s Disease

    Directory of Open Access Journals (Sweden)

    Yanmin Guo

    2015-01-01

    Full Text Available Objectives. Interactions between the host and gut microbial community contribute to the pathogenesis of Crohn’s disease (CD. In this study, we aimed to detect lipopolysaccharide (LPS and 1,3-β-D-glucan (BG in the sera of CD patients and clarify the potential role in the diagnosis and therapeutic approaches. Materials and Methods. Serum samples were collected from 46 patients with active CD (A-CD, 22 CD patients at remission stage (R-CD, and 20 healthy controls, and the levels of LPS, BG, and TNF in sera were determined by ELISA. Moreover, sixteen patients with A-CD received anti-TNF monoclonal antibody therapy (infliximab, IFX at a dose of 5 mg/kg body weight at weeks 0, 2, and 6, and the levels of LPS and BG were also tested at week 12 after the first intravenous infusion. Results. Serum levels of LPS and BG were found to be markedly increased in A-CD patients compared with R-CD patients and healthy controls (P<0.05. They were also observed to be positively correlated with CDAI, ESR, and SES-CD, respectively (P<0.05. Furthermore, the levels of TNF in sera had a significant correlation with LPS and BG, respectively. The concentrations of LPS and BG were demonstrated to be significantly downregulated in the sera of A-CD patients 12 weeks after IFX treatment (P<0.05, suggesting that blockade of TNF could inhibit bacterial endotoxin absorption, partially through improving intestinal mucosal barrier. Conclusions. Serum levels of LPS and BG are significantly increased in A-CD patients and positively correlated with the severity of the disease. Blockade of intestinal mucosal inflammation with IFX could reduce the levels of LPS and BG in sera. Therefore, this study has shed some light on measurement of serum LPS and BG in the diagnosis and treatment of CD patients.

  8. An LPS based method to stimulate the inflammatory response in growing rabbits

    Directory of Open Access Journals (Sweden)

    C. Knudsen

    2016-03-01

    Full Text Available Reliable indicators are needed to study the relationship between the inflammatory response of the growing rabbit and breeding factors such as feeding practices. A lipopolysaccharide (LPS stimulation of the inflammatory response is a valid model of bacterial infection in laboratory animals, but no data on the growing rabbit has yet been obtained. The aim of our study was to determine an adequate dose of LPS to inject in growing rabbits in order to elicit a measurable inflammatory response in terms of plasmatic TNF-α and rise in rectal temperature. Three trials were carried out in this study: 2 development trials, the first (n=18 testing 3 doses of LPS (2, 10, 50 μg/kg on the plasmatic TNF-α concentration at 90 and 180 min post injection, and the second trial (n=36 testing 4 doses of LPS (50, 75, 100 and 150 μg/kg on the TNF-α concentration 90 min post injection and the rectal temperature. The third trial was designed as an application of the method in a large number of animals (n=32 to study the effect of feed restriction and dietary increase in digestible fibre to starch ratio on the LPS inflammatory challenge response of growing rabbits. In development trials 1 and 2, animals had measurable TNF-α responses for doses higher than 10 μg/kg at 90 min post injection, with an increase in the number of responsive animals along with the dose. High variability was observed in TNF-α concentrations in responsive animals (coefficient of variation from 44 to 94%. Animals demonstrated an increase in rectal temperature for all doses injected in the range of 50-150 μg/kg from 90 min post injection with a peak at 180 min (ΔTr =1.9±0.7°C. Our observations led us to choose a dose of 100 μg/kg of LPS for our following studies, as the responses in terms of temperature and TNF-α were the most satisfactory. The application of our LPS injection protocol to our nutritional study enabled us to validate our protocol (ΔTr =1.1±0.7°C at 180 min and 15

  9. MicroRNA-146 protects A549 and H1975 cells from LPS-induced ...

    Indian Academy of Sciences (India)

    The presentstudy explored the protective effects of miR-146 overexpression on lipopolysaccharide (LPS)-mediated injury in A549 andH1975 cells. In this study, A549 and H1975 cells were transfected with miR-146 mimic or inhibitor, and then weresubjected with LPS. Thereafter, cell viability, colony formation capacity, ...

  10. LPS Promotes Pre-osteoclast Activity by Up-regulating CXCR4 via TLR-4

    NARCIS (Netherlands)

    Xing, Q.; de Vos, P.; Faas, M. M.; Ye, Q.; Ren, Y.

    Lipopolysaccharide (LPS) has been shown to be a prominent pathogenic factor in inflammatory bone loss. However, knowledge of the mechanisms involved is limited. The role of the SDF-1/CXCR4 (Stromal-derived factor-1 and its unique chemokine receptor) axis in LPS-induced bone loss has not been

  11. Investigating the CYP2E1 Potential Role in the Mechanisms Behind INH/LPS-Induced Hepatotoxicity.

    Science.gov (United States)

    Hassan, Hozeifa M; Yousef, Bashir A; Guo, Hongli; Xiaoxin, Liu; Zhang, Luyong; Jiang, Zhenzhou

    2018-01-01

    Tuberculosis (TB) is one of the oldest infectious diseases that affected humankind and remains one of the world's deadliest communicable diseases that could be considered as global emergency, but the discovery and development of isoniazid (INH) in the 1950s paved the way to an effective single and/or combined first-line anti-TB therapy. However, administration of INH induces severe hepatic toxicity in some patients. Previously, we establish a rat model of INH hepatotoxicity utilizing the inflammatory stress theory, in which bacterial lipopolysaccharide (LPS) potentially enhanced INH toxicity. These enhancing activities ranged between augmenting the inflammatory stress, oxidative stress, alteration of bile acid homeostasis, and CYP2E1 over-expression. Although pre-treatment with dexamethasone (DEX) helped overcome both inflammatory and oxidative stress which ended-up in alleviation of LPS augmenting effects, but still minor toxicities were being detected, alongside with CYP2E1 over expression. This finding positively indicated the corner-stone role played by CYP2E1 in the pathogenesis of INH/LPS-induced liver damage. Therefore, we examined whether INH/LPS co-treatment with CYP2E1 inhibitor diallyl sulfide (DAS) and DEX can protect against the INH/LPS-induced hepatotoxicity. Our results showed that pre-administration of both DAS and DEX caused significant reduction in serum TBA, TBil, and gamma-glutamyl transferase levels. Furthermore, the histopathological analysis showed that DAS and DEX could effectively reverse the liver lesions seen following INH/LPS treatment and protect against hepatic steatosis as indicated by absence of lipid accumulation. Pre-treatment with DAS alone could not completely block the CYP2E1 protein expression following INH/LPS treatment, as appeared in the immunoblotting and immunohistochemistry results. This is probably due to the fact that the combined enhancement activities of both INH and LPS on CYP2E1 protein expression levels might

  12. Investigating the CYP2E1 Potential Role in the Mechanisms Behind INH/LPS-Induced Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Hozeifa M. Hassan

    2018-03-01

    Full Text Available Tuberculosis (TB is one of the oldest infectious diseases that affected humankind and remains one of the world’s deadliest communicable diseases that could be considered as global emergency, but the discovery and development of isoniazid (INH in the 1950s paved the way to an effective single and/or combined first-line anti-TB therapy. However, administration of INH induces severe hepatic toxicity in some patients. Previously, we establish a rat model of INH hepatotoxicity utilizing the inflammatory stress theory, in which bacterial lipopolysaccharide (LPS potentially enhanced INH toxicity. These enhancing activities ranged between augmenting the inflammatory stress, oxidative stress, alteration of bile acid homeostasis, and CYP2E1 over-expression. Although pre-treatment with dexamethasone (DEX helped overcome both inflammatory and oxidative stress which ended-up in alleviation of LPS augmenting effects, but still minor toxicities were being detected, alongside with CYP2E1 over expression. This finding positively indicated the corner-stone role played by CYP2E1 in the pathogenesis of INH/LPS-induced liver damage. Therefore, we examined whether INH/LPS co-treatment with CYP2E1 inhibitor diallyl sulfide (DAS and DEX can protect against the INH/LPS-induced hepatotoxicity. Our results showed that pre-administration of both DAS and DEX caused significant reduction in serum TBA, TBil, and gamma-glutamyl transferase levels. Furthermore, the histopathological analysis showed that DAS and DEX could effectively reverse the liver lesions seen following INH/LPS treatment and protect against hepatic steatosis as indicated by absence of lipid accumulation. Pre-treatment with DAS alone could not completely block the CYP2E1 protein expression following INH/LPS treatment, as appeared in the immunoblotting and immunohistochemistry results. This is probably due to the fact that the combined enhancement activities of both INH and LPS on CYP2E1 protein expression

  13. Effect of methanolic extract of Asparagus racemosus Willd. on lipopolysaccharide induced-oxidative stress in rats.

    Science.gov (United States)

    Ahmad, Mohammad Parwez; Hussain, Arshad; Siddiqui, Hefazat Hussain; Wahab, Shadma; Adak, Manoranjan

    2015-03-01

    Lipopolysaccharide (LPS) induced oxidative stress and impairment of normal physiological function generally categorized by increased anxiety and reduced mobility. Therefore, the present study was to find out the effect Methanolic extract of Asparagus racemosus (MEAR ) in lipopolysaccharide (LPS)-induced oxidative stress in rats . LPS-induced oxidative stress in rats was measured by locomotor activity by photoactometer test, anxiety with elevated plus maze test and also studied the oxidative stress markers, nitric oxide and cytokines. The obtained data shows that LPS markedly exhausted (pAsparagus racemosus Willd. is a functionally newer type of cerebroprotective agent.

  14. The Deep-Sea Polyextremophile Halobacteroides lacunaris TB21 Rough-Type LPS: Structure and Inhibitory Activity towards Toxic LPS

    Science.gov (United States)

    Di Lorenzo, Flaviana; Palmigiano, Angelo; Paciello, Ida; Pallach, Mateusz; Garozzo, Domenico; Bernardini, Maria-Lina; La Cono, Violetta; Yakimov, Michail M.; Molinaro, Antonio; Silipo, Alba

    2017-01-01

    The structural characterization of the lipopolysaccharide (LPS) from extremophiles has important implications in several biomedical and therapeutic applications. The polyextremophile Gram-negative bacterium Halobacteroides lacunaris TB21, isolated from one of the most extreme habitats on our planet, the deep-sea hypersaline anoxic basin Thetis, represents a fascinating microorganism to investigate in terms of its LPS component. Here we report the elucidation of the full structure of the R-type LPS isolated from H. lacunaris TB21 that was attained through a multi-technique approach comprising chemical analyses, NMR spectroscopy, and Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry. Furthermore, cellular immunology studies were executed on the pure R-LPS revealing a very interesting effect on human innate immunity as an inhibitor of the toxic Escherichia coli LPS. PMID:28653982

  15. Anti-inflammatory activity of cinnamon water extract in vivo and in vitro LPS-induced models

    Directory of Open Access Journals (Sweden)

    Hong Joung-Woo

    2012-11-01

    Full Text Available Abstract Background Cinnamon bark is one of the most popular herbal ingredients in traditional oriental medicine and possesses diverse pharmacological activities including anti-bacterial, anti-viral, and anti-cancer properties. The goal of this study is to investigate the in vivo and in vitro inhibitory effect of cinnamon water extract (CWE on lipopolysaccharide (LPS-induced tumor necrosis factor (TNF-α and its underlying intracellular mechanisms. Methods CWE was orally administrated to mice for 6 days prior to intraperitoneal injection of LPS. Serum levels of TNF-α and interleukin (IL-6 were determined 1 hour after LPS stimulation. Peritoneal macrophages from thioglycollate-injected mice were isolated and assayed for viability, cytokine expression and signaling molecules upon LPS stimulation. CWE was further fractioned according to molecular size, and the levels of total polyphenols and biological activities of each fraction were measured. Results The oral administration of CWE to mice significantly decreased the serum levels of TNF-α and IL-6. CWE treatment in vitro decreased the mRNA expression of TNF-α. CWE blocked the LPS-induced degradation of IκBα as well as the activation of JNK, p38 and ERK1/2. Furthermore, size-based fractionation of CWE showed that the observed inhibitory effect of CWE in vitro occurred in the fraction containing the highest level of total polyphenols. Conclusions Treatment with CWE decreased LPS-induced TNF-α in serum. In vitro inhibition of TNF-α gene by CWE may occur via the modulation of IκBα degradation and JNK, p38, and ERK1/2 activation. Our results also indicate that the observed anti-inflammatory action of CWE may originate from the presence of polyphenols.

  16. MODULATING LPS SIGNAL TRANSDUCTION AT THE LPS RECEPTOR COMPLEX WITH SYNTHETIC LIPID A ANALOGUES

    Science.gov (United States)

    White, Aileen F. B.; Demchenko, Alexei V.

    2015-01-01

    Sepsis, defined as a clinical syndrome brought about by an amplified and dysregulated inflammatory response to infections, is one of the leading causes of death worldwide. Despite persistent attempts to develop treatment strategies to manage sepsis in the clinical setting, the basic elements of treatment have not changed since the 1960s. As such, the development of effective therapies for reducing inflammatory reactions and end-organ dysfunction in critically ill patients with sepsis remains a global priority. Advances in understanding of the immune response to sepsis provide the opportunity to develop more effective pharmaceuticals. This article details current information on the modulation of the lipopolysaccharide (LPS) receptor complex with synthetic Lipid A mimetics. As the initial and most critical event in sepsis pathophysiology, the LPS receptor provides an attractive target for antisepsis agents. One of the well-studied approaches to sepsis therapy involves the use of derivatives of Lipid A, the membrane-anchor portion of an LPS, which is largely responsible for its endotoxic activity. This article describes the structural and conformational requirements influencing the ability of Lipid A analogues to compete with LPS for binding to the LPS receptor complex and to inhibit the induction of the signal transduction pathway by impairing LPS-initiated receptor dimerization. PMID:25480508

  17. Coxiella burnetii Lipopolysaccharide: What Do We Know?

    Directory of Open Access Journals (Sweden)

    Prasad Abnave

    2017-11-01

    Full Text Available A small gram-negative bacterium, Coxiella burnetii (C. burnetii, is responsible for a zoonosis called Q fever. C. burnetii is an intracellular bacterium that can survive inside microbicidal cells like monocytes and macrophages by hijacking several functions of the immune system. Among several virulence factors, the lipopolysaccharide (LPS of C. burnetii is one of the major factors involved in this immune hijacking because of its atypical composition and structure. Thus, the aim of this mini-review is to summarize the repressive effects of C. burnetii LPS on the antibacterial immunity of cells.

  18. Biphasic changes in fetal heart rate variability in preterm fetal sheep developing hypotension after acute on chronic lipopolysaccharide exposure.

    Science.gov (United States)

    Lear, Christopher A; Davidson, Joanne O; Booth, Lindsea C; Wassink, Guido; Galinsky, Robert; Drury, Paul P; Fraser, Mhoyra; Bennet, Laura; Gunn, Alistair J

    2014-08-15

    Perinatal exposure to infection is highly associated with adverse outcomes. Experimentally, acute, severe exposure to gram-negative bacterial lipopolysaccharide (LPS) is associated with increased fetal heart rate variability (FHRV). It is unknown whether FHRV is affected by subclinical infection with or without acute exacerbations. We therefore tested the hypothesis that FHRV would be associated with hypotension after acute on chronic exposure to LPS. Chronically instrumented fetal sheep at 0.7 gestation were exposed to a continuous low-dose LPS infusion (n = 12, 100 ng/kg over 24 h, followed by 250 ng·kg(-1)·24 h(-1) for a further 96 h) or the same volume of saline (n = 10). Boluses of either 1 μg LPS or saline were given at 48, 72, and 96 h. Low-dose infusion was not associated with hemodynamic or FHRV changes. The first LPS bolus was associated with tachycardia and suppression of nuchal electromyographic activity in all fetuses. Seven of twelve fetuses developed hypotension (a fall in mean arterial blood pressure ≥5 mmHg). FHRV was transiently increased only at the onset of hypotension, in association with increased cytokine induction and electroencephalogram suppression. FHRV then fell before the nadir of hypotension, with transient suppression of short-term FHRV. After the second LPS bolus, the hypotension group showed a biphasic pattern of a transient increase in FHRV followed by more prolonged suppression. These findings suggest that infection-related hypotension in the preterm fetus mediates the transient increase in FHRV and that repeated exposure to LPS leads to progressive loss of FHRV. Copyright © 2014 the American Physiological Society.

  19. Mutation of the Enterohemorrhagic Escherichia coli Core LPS Biosynthesis Enzyme RfaD Confers Hypersusceptibility to Host Intestinal Innate Immunity In vivo.

    Science.gov (United States)

    Kuo, Cheng-Ju; Chen, Jenn-Wei; Chiu, Hao-Chieh; Teng, Ching-Hao; Hsu, Tai-I; Lu, Pei-Jung; Syu, Wan-Jr; Wang, Sin-Tian; Chou, Ting-Chen; Chen, Chang-Shi

    2016-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed. Lipopolysaccharides (LPS) are surface glycolipids found on the outer membrane of gram-negative bacteria, including EHEC, and LPS biosynthesis has long been considered as potential anti-bacterial target. Here, we demonstrated that the EHEC rfaD gene that functions in the biosynthesis of the LPS inner core is required for the intestinal colonization and pathogenesis of EHEC in vivo. Disruption of the EHEC rfaD confers attenuated toxicity in Caenorhabditis elegans and less bacterial colonization in the intestine of C. elegans and mouse. Moreover, rfaD is also involved in the control of susceptibility of EHEC to antimicrobial peptides and host intestinal immunity. It is worth noting that rfaD mutation did not interfere with the growth kinetics when compared to the wild-type EHEC cells. Taken together, we demonstrated that mutations of the EHEC rfaD confer hypersusceptibility to host intestinal innate immunity in vivo, and suggested that targeting the RfaD or the core LPS synthesis pathway may provide alternative therapeutic regimens for EHEC infection.

  20. Synthetic antimicrobial and LPS-neutralising peptides suppress inflammatory and immune responses in skin cells and promote keratinocyte migration.

    Science.gov (United States)

    Pfalzgraff, Anja; Heinbockel, Lena; Su, Qi; Gutsmann, Thomas; Brandenburg, Klaus; Weindl, Günther

    2016-08-11

    The stagnation in the development of new antibiotics and the concomitant high increase of resistant bacteria emphasize the urgent need for new therapeutic options. Antimicrobial peptides are promising agents for the treatment of bacterial infections and recent studies indicate that Pep19-2.5, a synthetic anti-lipopolysaccharide (LPS) peptide (SALP), efficiently neutralises pathogenicity factors of Gram-negative (LPS) and Gram-positive (lipoprotein/-peptide, LP) bacteria and protects against sepsis. Here, we investigated the potential of Pep19-2.5 and the structurally related compound Pep19-4LF for their therapeutic application in bacterial skin infections. SALPs inhibited LP-induced phosphorylation of NF-κB p65 and p38 MAPK and reduced cytokine release and gene expression in primary human keratinocytes and dermal fibroblasts. In LPS-stimulated human monocyte-derived dendritic cells and Langerhans-like cells, the peptides blocked IL-6 secretion, downregulated expression of maturation markers and inhibited dendritic cell migration. Both SALPs showed a low cytotoxicity in all investigated cell types. Furthermore, SALPs markedly promoted cell migration via EGFR transactivation and ERK1/2 phosphorylation and accelerated artificial wound closure in keratinocytes. Peptide-induced keratinocyte migration was mediated by purinergic receptors and metalloproteases. In contrast, SALPs did not affect proliferation of keratinocytes. Conclusively, our data suggest a novel therapeutic target for the treatment of patients with acute and chronic skin infections.

  1. Pretreatment of Low-Dose and Super-Low-Dose LPS on the Production of In Vitro LPS-Induced Inflammatory Mediators

    Science.gov (United States)

    Chae, Byeong Suk

    2018-01-01

    Pretreatment of low-dose lipopolysaccharide (LPS) induces a hyporesponsive state to subsequent secondary challenge with high-dose LPS in innate immune cells, whereas super-low-dose LPS results in augmented expression of pro-inflammatory cytokines. However, little is known about the difference between super-low-dose and low-dose LPS pretreatments on immune cell-mediated inflammatory and hepatic acute-phase responses to secondary LPS. In the present study, RAW 264.7 cells, EL4 cells, and Hepa-1c1c7 cells were pretreated with super-low-dose LPS (SL-LPS: 50 pg/mL) or low-dose LPS (L-LPS: 50 ng/mL) in fresh complete medium once a day for 2~3 days and then cultured in fresh complete medium for 24 hr or 48 hr in the presence or absence of LPS (1~10 μg/mL) or concanavalin A (Con A). SL-LPS pretreatment strongly enhanced the LPS-induced production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, TNF-α/IL-10, prostaglandin E2 (PGE2), and nitric oxide (NO) by RAW 264.7 cells compared to the control, whereas L-LPS increased IL-6 and NO production only. SL-LPS strongly augmented the Con A-induced ratios of interferon (IFN)-γ/IL-10 in EL4 cells but decreased the LPS-induced ratios of IFN-γ/IL-10 compared to the control, while L-LPS decreased the Con A- and LPS-induced ratios of IFN-γ/IL-10. SL-LPS enhanced the LPS-induced production of IL-6 by Hepa1c1c-7 cells compared to the control, while L-LPS increased IL-6 but decreased IL-1β and C reactive protein (CRP) levels. SL-LPS pretreatment strongly enhanced the LPS-induced production of TNF-α, IL-6, IL-10, PGE2, and NO in RAW 264.7 cells, and the IL-6, IL-1β, and CRP levels in Hepa1c1c-7 cells, as well as the ratios of IFN-γ/IL-10 in LPS- and Con A-stimulated EL4 cells compared to L-LPS. These findings suggest that pre-conditioning of SL-LPS may contribute to the mortality to secondary infection in sepsis rather than pre-conditioning of L-LPS. PMID:29372003

  2. Pretreatment of Low-Dose and Super-Low-Dose LPS on the Production ofIn VitroLPS-Induced Inflammatory Mediators.

    Science.gov (United States)

    Chae, Byeong Suk

    2018-01-01

    Pretreatment of low-dose lipopolysaccharide (LPS) induces a hyporesponsive state to subsequent secondary challenge with high-dose LPS in innate immune cells, whereas super-low-dose LPS results in augmented expression of pro-inflammatory cytokines. However, little is known about the difference between super-low-dose and low-dose LPS pretreatments on immune cell-mediated inflammatory and hepatic acute-phase responses to secondary LPS. In the present study, RAW 264.7 cells, EL4 cells, and Hepa-1c1c7 cells were pretreated with super-low-dose LPS (SL-LPS: 50 pg/mL) or low-dose LPS (L-LPS: 50 ng/mL) in fresh complete medium once a day for 2~3 days and then cultured in fresh complete medium for 24 hr or 48 hr in the presence or absence of LPS (1~10 μg/mL) or concanavalin A (Con A). SL-LPS pretreatment strongly enhanced the LPS-induced production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, TNF-α/IL-10, prostaglandin E2 (PGE 2 ), and nitric oxide (NO) by RAW 264.7 cells compared to the control, whereas L-LPS increased IL-6 and NO production only. SL-LPS strongly augmented the Con A-induced ratios of interferon (IFN)-γ/IL-10 in EL4 cells but decreased the LPS-induced ratios of IFN-γ/IL-10 compared to the control, while L-LPS decreased the Con A- and LPS-induced ratios of IFN-γ/IL-10. SL-LPS enhanced the LPS-induced production of IL-6 by Hepa1c1c-7 cells compared to the control, while L-LPS increased IL-6 but decreased IL-1β and C reactive protein (CRP) levels. SL-LPS pretreatment strongly enhanced the LPS-induced production of TNF-α, IL-6, IL-10, PGE 2 , and NO in RAW 264.7 cells, and the IL-6, IL-1β, and CRP levels in Hepa1c1c-7 cells, as well as the ratios of IFN-γ/IL-10 in LPS- and Con A-stimulated EL4 cells compared to L-LPS. These findings suggest that pre-conditioning of SL-LPS may contribute to the mortality to secondary infection in sepsis rather than pre-conditioning of L-LPS.

  3. Bacterial components are the major contributors to the macrophage stimulating activity exhibited by extracts of common edible mushrooms.

    Science.gov (United States)

    Tyler, Heather L; Haron, Mona H; Pugh, Nirmal D; Zhang, Jin; Jackson, Colin R; Pasco, David S

    2016-10-12

    Recent studies have indicated that a major contributor to the innate immune enhancing properties of some medicinal plants is derived from the cell wall components of bacteria colonizing these plants. The purpose of the current study was to assess if the bacteria present within edible and medicinal mushrooms substantially contribute to the innate immune stimulating potential of these mushrooms. Whole mushrooms from thirteen types of edible fungi and individual parts from Agaricus bisporus were analyzed for in vitro macrophage activation as well as bacterial lipopolysaccharides (LPS) content, cell load, and community composition. Substantial variation between samples was observed in macrophage activation (over 500-fold), total bacterial load (over 200-fold), and LPS content (over 10 million-fold). Both LPS content (ρ = 0.832, p mushroom extracts. Extract activity was negated by treatment with NaOH, conditions that inactivate LPS and other bacterial components. Significant correlations between macrophage activation and total bacterial load (ρ = 0.723, p = 0.0001) and LPS content (ρ = 0.951, p mushroom associated bacteria contribute substantially to the innate immune enhancing activity exhibited by mushrooms and may result in similar therapeutic actions as reported for ingestion of bacterial preparations such as probiotics.

  4. Pasteurella multocida Heddleston Serovar 3 and 4 Strains Share a Common Lipopolysaccharide Biosynthesis Locus but Display both Inter- and Intrastrain Lipopolysaccharide Heterogeneity

    Science.gov (United States)

    Harper, Marina; St. Michael, Frank; John, Marietta; Vinogradov, Evgeny; Steen, Jennifer A.; van Dorsten, Lieke; Steen, Jason A.; Turni, Conny; Blackall, Patrick J.; Adler, Ben; Cox, Andrew D.

    2013-01-01

    Pasteurella multocida is a Gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. The major outer membrane component lipopolysaccharide (LPS) is both an important virulence factor and a major immunogen. Our previous studies determined the LPS structures expressed by different P. multocida strains and revealed that a number of strains belonging to different serovars contain the same LPS biosynthesis locus but express different LPS structures due to mutations within glycosyltransferase genes. In this study, we report the full LPS structure of the serovar 4 type strain, P1662, and reveal that it shares the same LPS outer core biosynthesis locus, L3, with the serovar 3 strains P1059 and Pm70. Using directed mutagenesis, the role of each glycosyltransferase gene in LPS outer core assembly was determined. LPS structural analysis of 23 Australian field isolates that contain the L3 locus revealed that at least six different LPS outer core structures can be produced as a result of mutations within the LPS glycosyltransferase genes. Moreover, some field isolates produce multiple but related LPS glycoforms simultaneously, and three LPS outer core structures are remarkably similar to the globo series of vertebrate glycosphingolipids. Our in-depth analysis showing the genetics and full range of P. multocida lipopolysaccharide structures will facilitate the improvement of typing systems and the prediction of the protective efficacy of vaccines. PMID:23974032

  5. The effect of Porphyromonas gingivalis lipopolysaccharide on pregnancy in the rat

    NARCIS (Netherlands)

    Kunnen, A; van Pampus, M G; Aarnoudse, J G; van der Schans, C P; Abbas, F; Faas, M M

    OBJECTIVE: Periodontitis, mostly associated with Porphyromonas gingivalis, has frequently been related to adverse pregnancy outcomes. We therefore investigated whether lipopolysaccharides of P. gingivalis (Pg-LPS) induced pregnancy complications in the rat. METHODS: Experiment 1: pregnant rats (day

  6. IL-12 Inhibits Lipopolysaccharide Stimulated Osteoclastogenesis in Mice

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    Masako Yoshimatsu

    2015-01-01

    Full Text Available Lipopolysaccharide (LPS is related to osteoclastogenesis in osteolytic diseases. Interleukin- (IL- 12 is an inflammatory cytokine that plays a critical role in host defense. In this study, we investigated the effects of IL-12 on LPS-induced osteoclastogenesis. LPS was administered with or without IL-12 into the supracalvariae of mice, and alterations in the calvarial suture were evaluated histochemically. The number of osteoclasts in the calvarial suture and the mRNA level of tartrate-resistant acid phosphatase (TRAP, an osteoclast marker, were lower in mice administered LPS with IL-12 than in mice administered LPS alone. The serum level of tartrate-resistant acid phosphatase 5b (TRACP 5b, a bone resorption marker, was also lower in mice administered LPS with IL-12 than in mice administered LPS alone. These results revealed that IL-12 might inhibit LPS-induced osteoclastogenesis and bone resorption. In TdT-mediated dUTP-biotin nick end-labeling (TUNEL assays, apoptotic changes in cells were recognized in the calvarial suture in mice administered LPS with IL-12. Furthermore, the mRNA levels of both Fas and FasL were increased in mice administered LPS with IL-12. Taken together, the findings demonstrate that LPS-induced osteoclastogenesis is inhibited by IL-12 and that this might arise through apoptotic changes in osteoclastogenesis-related cells induced by Fas/FasL interactions.

  7. 3'UTR AU-Rich Elements (AREs) and the RNA-Binding Protein Tristetraprolin (TTP) Are Not Required for the LPS-Mediated Destabilization of Phospholipase-Cβ-2 mRNA in Murine Macrophages.

    Science.gov (United States)

    Shukla, Smita; Elson, Genie; Blackshear, Perry J; Lutz, Carol S; Leibovich, S Joseph

    2017-04-01

    We have shown previously that bacterial lipopolysaccharide (LPS)-mediated suppression of phospholipase-Cβ-2 (PLCβ-2) expression is involved in M1 (inflammatory) to M2-like (wound healing) phenotypic switching of macrophages triggered by adenosine. This suppression is mediated post-transcriptionally by destabilization of PLCβ-2 mRNA (messenger ribonucleic acid). To investigate the mechanism of this LPS-mediated destabilization, we examined the roles of RNA-binding agents including microRNAs and RNA-binding proteins that are involved in regulating stability of mRNAs encoding growth factors, inflammatory mediators, and proto-oncogenes. Adenylate and uridylate (AU)-rich elements (AREs) in 3'UTRs are specific recognition sites for RNA-binding proteins including tristetraprolin (TTP), HuR, and AUF1 and for microRNAs that are involved in regulating mRNA stability. In this study, we investigated the role of TTP and AREs in regulating PLCβ-2 mRNA stability. The 3'UTR of the PLCβ-2 gene was inserted into the pLightswitch luciferase reporter plasmid and transfected into RAW264.7 cells. LPS suppressed luciferase expression from this reporter. Luciferase expression from mutant 3'UTR constructs lacking AREs was similarly downregulated, suggesting that these regions are not required for LPS-mediated suppression of PLCβ-2. TTP was rapidly upregulated in both primary murine macrophages and RAW264.7 cells in response to LPS. Suppression of PLCβ-2 by LPS was examined using macrophages from mice lacking TTP (TTP -/- ). LPS suppressed PLCβ-2 expression to the same extent in wild type (WT) and TTP -/- macrophages. Also, the rate of decay of PLCβ-2 mRNA in LPS-treated macrophages following transcriptional blockade was similar in WT and TTP -/- macrophages, clearly indicating that TTP is not involved in LPS-mediated destabilization of PLCβ-2 mRNA in macrophages.

  8. Differential Stimulatory Activities of Smooth and Rough Brucella abortus Lipopolysaccharide in Murine Macrophages

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    Raheela Akhtar1,2*, Yongqun O. He2, Charles B. Larson2, Zafar I. Chaudhary3 and Mansur ud-Din Ahmad4

    2012-06-01

    Full Text Available Brucella abortus lipopolysaccharide (LPS was isolated and purified from rough (RB51 and smooth (S2308 strains of Brucella. The LPS preparations were used to treat murine (RAW 264.7 macrophages in order to study their differential effects. Treated macrophages were tested by lysozyme release test (LRT, nitroblue tetrazolium test (NBT and nitric oxide (NO assay, respectively. Rough Brucella LPS induced significantly higher levels of lysozyme release, oxidative stress, and nitric oxide in murine macrophages than smooth Brucella LPS or combined LPS (rough + smooth LPS. These responses were dose-dependent. Macrophages treated with rough LPS were more Brucellacidal than those treated with smooth LPS. The minimal stimulation of murine macrophages by Brucella smooth LPS may provide basis for less active immune responses against smooth strains.

  9. Role of human amnion-derived mesenchymal stem cells in promoting osteogenic differentiation by influencing p38 MAPK signaling in lipopolysaccharide -induced human bone marrow mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuli; Wu, Hongxia; Shen, Ming; Ding, Siyang; Miao, Jing; Chen, Ning, E-mail: 2927410849@qq.com

    2017-01-01

    Periodontitis is a chronic inflammatory disease induced by bacterial pathogens, which not only affect connective tissue attachments but also cause alveolar bone loss. In this study, we investigated the anti-inflammatory effects of Human amnion-derived mesenchymal stem cells (HAMSCs) on human bone marrow mesenchymal stem cells (HBMSCs) under lipopolysaccharide (LPS)-induced inflammatory conditions. Proliferation levels were measured by flow cytometry and immunofluorescence staining of 5-ethynyl-2′-deoxyuridine (EdU). Osteoblastic differentiation and mineralization were investigated using chromogenic alkaline phosphatase activity (ALP) activity substrate assays, Alizarin red S staining, and RT-PCR analysis of HBMSCs osteogenic marker expression. Oxidative stress induced by LPS was investigated by assaying reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity. Here, we demonstrated that HAMSCs increased the proliferation, osteoblastic differentiation, and SOD activity of LPS-induced HBMSCs, and down-regulated the ROS level. Moreover, our results suggested that the activation of p38 MAPK signal transduction pathway is essential for reversing the LPS-induced bone-destructive processes. SB203580, a selective inhibitor of p38 MAPK signaling, significantly suppressed the anti-inflammatory effects in HAMSCs. In conclusion, HAMSCs show a strong potential in treating inflammation-induced bone loss by influencing p38 MAPK signaling. - Highlights: • LPS inhibites osteogenic differentiation in HBMSCs via suppression of p38 MAPK signaling pathway. • HAMSCs promote LPS-induced HBMSCs osteogenic differentiation through p38 MAPK signaling pathway. • HAMSCs reverse LPS-induced oxidative stress in LPS-induced HBMSCs through p38 MAPK signaling pathway.

  10. Nitric oxide production by hemocytes of larva and pharate prepupa of Galleria mellonella in response to bacterial lipopolysaccharide: cytoprotective or cytotoxic?

    Czech Academy of Sciences Publication Activity Database

    Krishnan, Natraj; Hyršl, P.; Šimek, V.

    2006-01-01

    Roč. 142, 1-2 (2006), s. 103-110 ISSN 1532-0456 Institutional research plan: CEZ:AV0Z50070508 Keywords : nitric oxide * hemocytes * lipopolysaccharide Subject RIV: ED - Physiology Impact factor: 1.991, year: 2006

  11. Preparation of a Lipopolysaccharide from Escherichia coli 01lla, 01llb, k58: h21 bacterial wall, labeled with carbon-14

    International Nuclear Information System (INIS)

    Solano Aunon, M. L.; Pacheco Lopez, J.; Garcia Pineda, M. D.; Roca, M.; Bayon, A.

    1981-01-01

    A brief description of the morphological and chemical structure of Li po polysaccharides is given, as well as its occurrence in nature and its mechanisms of action. It is emphasized the usefulness for actual biochemical and biomedical research of the labeled Lipopolysaccharide. The method for the labelling, isolation and purification of 14''C-Lipopolysacchari de is described. (Author) 23 refs

  12. Inhibitory effect of BMAP-28 on Leptospiral Lipopolysaccharide-Induced TLR2-Dependent Immune Response in Bovine Cells

    OpenAIRE

    GUO, Yijie; Ding, Cuiping; Zhang, Bo; XU, Jun; XUN, Meng; XU, Jiru

    2016-01-01

    Background Bovine leptospirosis is a widespread zoonotic disease, leading to serious economic losses in animal production and causing potential hazards to human health. Leptospiral lipopolysaccharide (L-LPS) plays an important role in leptospirosis pathogenicity. Objectives With respect to L-LPS endotoxin-like activity, we examined bovine immune response to L-LPS and the inhibitory ability of bovine myeloid antimicrobial peptide-28 (BMAP-28) against L-LPS-induced immune activation in bovine c...

  13. Microbiome-Derived Lipopolysaccharide Enriched in the Perinuclear Region of Alzheimer’s Disease Brain

    Directory of Open Access Journals (Sweden)

    Yuhai Zhao

    2017-09-01

    Full Text Available Abundant clinical, epidemiological, imaging, genetic, molecular, and pathophysiological data together indicate that there occur an unusual inflammatory reaction and a disruption of the innate-immune signaling system in Alzheimer’s disease (AD brain. Despite many years of intense study, the origin and molecular mechanics of these AD-relevant pathogenic signals are still not well understood. Here, we provide evidence that an intensely pro-inflammatory bacterial lipopolysaccharide (LPS, part of a complex mixture of pro-inflammatory neurotoxins arising from abundant Gram-negative bacilli of the human gastrointestinal (GI tract, are abundant in AD-affected brain neocortex and hippocampus. For the first time, we provide evidence that LPS immunohistochemical signals appear to aggregate in clumps in the parenchyma in control brains, and in AD, about 75% of anti-LPS signals were clustered around the periphery of DAPI-stained nuclei. As LPS is an abundant secretory product of Gram-negative bacilli resident in the human GI-tract, these observations suggest (i that a major source of pro-inflammatory signals in AD brain may originate from internally derived noxious exudates of the GI-tract microbiome; (ii that due to aging, vascular deficits or degenerative disease these neurotoxic molecules may “leak” into the systemic circulation, cerebral vasculature, and on into the brain; and (iii that this internal source of microbiome-derived neurotoxins may play a particularly strong role in shaping the human immune system and contributing to neural degeneration, particularly in the aging CNS. This “Perspectives” paper will further highlight some very recent developments that implicate GI-tract microbiome-derived LPS as an important contributor to inflammatory-neurodegeneration in the AD brain.

  14. The Myriad Properties of Pasteurella multocida Lipopolysaccharide

    Science.gov (United States)

    Harper, Marina; Boyce, John Dallas

    2017-01-01

    Pasteurella multocida is a heterogeneous species that is a primary pathogen of many different vertebrates. This Gram-negative bacterium can cause a range of diseases, including fowl cholera in birds, haemorrhagic septicaemia in ungulates, atrophic rhinitis in swine, and lower respiratory tract infections in cattle and pigs. One of the primary virulence factors of P. multocida is lipopolysaccharide (LPS). Recent work has shown that this crucial surface molecule shows significant structural variability across different P. multocida strains, with many producing LPS structures that are highly similar to the carbohydrate component of host glycoproteins. It is likely that this LPS mimicry of host molecules plays a major role in the survival of P. multocida in certain host niches. P. multocida LPS also plays a significant role in resisting the action of chicken cathelicidins, and is a strong stimulator of host immune responses. The inflammatory response to the endotoxic lipid A component is a major contributor to the pathogenesis of certain infections. Recent work has shown that vaccines containing killed bacteria give protection only against other strains with identical, or nearly identical, surface LPS structures. Conversely, live attenuated vaccines give protection that is broadly protective, and their efficacy is independent of LPS structure. PMID:28825691

  15. Differential impact of lipopolysaccharide defects caused by loss of RfaH in Yersinia pseudotuberculosis and Yersinia pestis.

    Science.gov (United States)

    Hoffman, Jared M; Sullivan, Shea; Wu, Erin; Wilson, Eric; Erickson, David L

    2017-09-07

    RfaH enhances transcription of a select group of operons controlling bacterial surface features such as lipopolysaccharide (LPS). Previous studies have suggested that rfaH may be required for Yersinia pseudotuberculosis resistance to antimicrobial chemokines and survival during mouse infections. In order to further investigate the role of RfaH in LPS synthesis, resistance to host defense peptides, and virulence of Yersinia, we constructed ΔrfaH mutants of Y. pseudotuberculosis IP32953 and Y. pestis KIM6+. Loss of rfaH affected LPS synthesis in both species, resulting in a shorter core oligosaccharide. Susceptibility to polymyxin and the antimicrobial chemokine CCL28 was increased by loss of rfaH in Y. pseudotuberculosis but not in Y. pestis. Transcription of genes in the ddhD-wzz O-antigen gene cluster, but not core oligosaccharide genes, was reduced in ΔrfaH mutants. In addition, mutants with disruptions in specific ddhD-wzz O-antigen cluster genes produced LPS that was indistinguishable from the ΔrfaH mutant. This suggests that both Y. pseudotuberculosis and Y. pestis produce an oligosaccharide core with a single O-antigen unit attached in an RfaH-dependent fashion. Despite enhanced sensitivity to host defense peptides, the Y. pseudotuberculosis ΔrfaH strain was not attenuated in mice, suggesting that rfaH is not required for acute infection.

  16. LPS infusion suppresses serum FGF21 levels in healthy adult volunteers

    DEFF Research Database (Denmark)

    Lauritzen, Esben Stistrup; Rittig, Nikolaj; Bach, Ermina

    2017-01-01

    circulating levels of FGF21 after lipopolysaccharide (LPS) infusion. DESIGN: Two randomized, single blinded, placebo-controlled crossover trials were used. SETTING: The studies were performed at a university hospital clinical research center. PATIENTS AND INTERVENTIONS: Study 1 (LPS bolus): Eight young......, healthy, lean males were investigated two times: 1) after isotonic saline injection, and 2) after LPS injection (bolus of 1 ng/kg). Each study day lasted 4 hours. Study 2 (continuous LPS infusion): Eight, healthy males were investigated two times: 1) during continuously isotonic saline infusion, and 2......) during continuously LPS infusion (0.06 ng/kg/h). Each study day lasted 4 hours. Circulating FGF21 levels were quantified every second hour by an immunoassay. RESULTS: A LPS bolus resulted in a late suppression (t = 240 minutes) of serum FGF21 (P=0.035). Continuous LPS infusion revealed no significant...

  17. Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: impacts on immunity and metabolism.

    Science.gov (United States)

    Dong, Guozhong; Liu, Shimin; Wu, Yongxia; Lei, Chunlong; Zhou, Jun; Zhang, Sen

    2011-08-09

    Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA), occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS) is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA), haptoglobin (Hp), LPS binding protein (LBP), and C-reactive protein (CRP) in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydroxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn) are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP) are associated with declines in milk fat content

  18. Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: Impacts on immunity and metabolism

    Directory of Open Access Journals (Sweden)

    Zhou Jun

    2011-08-01

    Full Text Available Abstract Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA, occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA, haptoglobin (Hp, LPS binding protein (LBP, and C-reactive protein (CRP in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydoxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP are associated with declines in

  19. Early Effects of Lipopolysaccharide-Induced Inflammation on Foetal Brain Development in Rat

    Directory of Open Access Journals (Sweden)

    Cristina A Ghiani

    2011-10-01

    Full Text Available Studies in humans and animal models link maternal infection and imbalanced levels of inflammatory mediators in the foetal brain to the aetiology of neuropsychiatric disorders. In a number of animal models, it was shown that exposure to viral or bacterial agents during a period that corresponds to the second trimester in human gestation triggers brain and behavioural abnormalities in the offspring. However, little is known about the early cellular and molecular events elicited by inflammation in the foetal brain shortly after maternal infection has occurred. In this study, maternal infection was mimicked by two consecutive intraperitoneal injections of 200 μg of LPS (lipopolysaccharide/kg to timed-pregnant rats at GD15 (gestational day 15 and GD16. Increased thickness of the CP (cortical plate and hippocampus together with abnormal distribution of immature neuronal markers and decreased expression of markers for neural progenitors were observed in the LPS-exposed foetal forebrains at GD18. Such effects were accompanied by decreased levels of reelin and the radial glial marker GLAST (glial glutamate transporter, and elevated levels of pro-inflammatory cytokines in maternal serum and foetal forebrains. Foetal inflammation elicited by maternal injections of LPS has discrete detrimental effects on brain development. The early biochemical and morphological changes described in this work begin to explain the sequelae of early events that underlie the neurobehavioural deficits reported in humans and animals exposed to prenatal insults.

  20. Bartonella quintana lipopolysaccharide is a natural antagonist of Toll-like receptor 4.

    NARCIS (Netherlands)

    Popa, C.; Abdollahi-Roodsaz, S.; Joosten, L.A.B.; Takahashi, N.; Sprong, T.; Matera, G.; Liberto, M.C.; Foca, A.; Deuren, M. van; Kullberg, B.J.; Berg, W.B. van den; Meer, J.W.M. van der; Netea, M.G.

    2007-01-01

    Bartonella quintana is a gram-negative microorganism that causes trench fever and chronic bacteremia. B. quintana lipopolysaccharide (LPS) was unable to induce the production of proinflammatory cytokines in human monocytes. Interestingly, B. quintana LPS is a potent antagonist of Toll-like receptor

  1. Ganglioside mimicry of Campylobacter jejuni lipopolysaccharides determines antiganglioside specificity in rabbits

    NARCIS (Netherlands)

    C.W. Ang (Wim); P.G. Noordzij (Peter); M.A. de Klerk; H.P. Endtz (Hubert); P.A. van Doorn (Pieter); J.D. Laman (Jon)

    2002-01-01

    textabstractThe core oligosaccharides of Campylobacter jejuni lipopolysaccharides (LPS) display molecular mimicry with gangliosides. Cross-reactive anti-LPS-antiganglioside antibodies have been implicated to show a crucial role in the pathogenesis of the Guillain-Barre and Miller

  2. Dietary L-arginine supplementation modulates lipopolysaccharide-induced systemic inflammatory response in broiler chickens

    Science.gov (United States)

    This study was conducted to evaluate whether dietary supplementation with L-arginine (Arg) could attenuate lipopolysaccharide (LPS)-induced systemic inflammatory response through LPS/TLR-4 signaling pathway in broilers. The experiment was designed as a 2 × 3 factorial arrangement (n = 8 cages/treatm...

  3. Bacterial and fungal markers in tobacco smoke

    Energy Technology Data Exchange (ETDEWEB)

    Szponar, B., E-mail: szponar@iitd.pan.wroc.pl [Lund University, Dept. of Laboratory Medicine, Soelvegatan 23, 223 62 Lund (Sweden); Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114 Wroclaw (Poland); Pehrson, C.; Larsson, L. [Lund University, Dept. of Laboratory Medicine, Soelvegatan 23, 223 62 Lund (Sweden)

    2012-11-01

    Previous research has demonstrated that cigarette smoke contains bacterial and fungal components including lipopolysaccharide (LPS) and ergosterol. In the present study we used gas chromatography-mass spectrometry to analyze tobacco as well as mainstream and second hand smoke for 3-hydroxy fatty acids (3-OH FAs) of 10 to 18 carbon chain lengths, used as LPS markers, and ergosterol, used as a marker of fungal biomass. The air concentrations of LPS were 0.0017 nmol/m{sup 3} (N = 5) and 0.0007/m{sup 3} (N = 6) in the smoking vs. non-smoking rooms (p = 0.0559) of the studied private houses, and 0.0231 nmol/m{sup 3} (N = 5) vs. 0.0006 nmol/m{sup 3} (N = 5) (p = 0.0173), respectively, at the worksite. The air concentrations of ergosterol were also significantly higher in rooms with ongoing smoking than in rooms without smoking. A positive correlation was found between LPS and ergosterol in rooms with smoking but not in rooms without smoking. 3-OH C14:0 was the main 3-OH FA, followed by 3-OH C12:0, both in mainstream and second hand smoke and in phenol:water smoke extracts prepared in order to purify the LPS. The Limulus activity of the phenolic phase of tobacco was 3900 endotoxin units (EU)/cigarette; the corresponding amount of the smoke, collected on filters from 8 puffs, was 4 EU/cigarette. Tobacco smoking has been associated with a range of inflammatory airway conditions including COPD, asthma, bronchitis, alveolar hypersensitivity etc. Significant levels of LPS and ergosterol were identified in tobacco smoke and these observations support the hypothesis that microbial components of tobacco smoke contribute to inflammation and airway disease. -- Highlights: Black-Right-Pointing-Pointer Air concentration of bacterial and fungal markers is significantly higher in rooms with ongoing smoking than without smoking. Black-Right-Pointing-Pointer Bacterial LPS correlates with fungal marker in rooms with ongoing smoking but not without smoking. Black-Right-Pointing-Pointer LPS

  4. Gut microbiota and lipopolysaccharide content of the diet influence development of regulatory T cells: studies in germ-free mice.

    Science.gov (United States)

    Hrncir, Tomas; Stepankova, Renata; Kozakova, Hana; Hudcovic, Tomas; Tlaskalova-Hogenova, Helena

    2008-11-06

    Mammals are essentially born germ-free but the epithelial surfaces are promptly colonized by astounding numbers of bacteria soon after birth. The most extensive microbial community is harbored by the distal intestine. The gut microbiota outnumber ~10 times the total number of our somatic and germ cells. The host-microbiota relationship has evolved to become mutually beneficial. Studies in germ-free mice have shown that gut microbiota play a crucial role in the development of the immune system. The principal aim of the present study was to elucidate whether the presence of gut microbiota and the quality of a sterile diet containing various amounts of bacterial contaminants, measured by lipopolysaccharide (LPS) content, can influence maturation of the immune system in gnotobiotic mice. We have found that the presence of gut microbiota and to a lesser extent also the LPS-rich sterile diet drive the expansion of B and T cells in Peyer's patches and mesenteric lymph nodes. The most prominent was the expansion of CD4+ T cells including Foxp3-expressing T cells in mesenteric lymph nodes. Further, we have observed that both the presence of gut microbiota and the LPS-rich sterile diet influence in vitro cytokine profile of spleen cells. Both gut microbiota and LPS-rich diet increase the production of interleukin-12 and decrease the production of interleukin-4. In addition, the presence of gut microbiota increases the production of interleukin-10 and interferon-gamma. Our data clearly show that not only live gut microbiota but also microbial components (LPS) contained in sterile diet stimulate the development, expansion and function of the immune system. Finally, we would like to emphasize that the composition of diet should be regularly tested especially in all gnotobiotic models as the LPS content and other microbial components present in the diet may significantly alter the outcome of experiments.

  5. The transcription factor C/EBP-β mediates constitutive and LPS-inducible transcription of murine SerpinB2.

    Directory of Open Access Journals (Sweden)

    Ekemini A Udofa

    Full Text Available SerpinB2 or plasminogen activator inhibitor type 2 (PAI-2 is highly induced in macrophages in response to inflammatory stimuli and is linked to the modulation of innate immunity, macrophage survival, and inhibition of plasminogen activators. Lipopolysaccharide (LPS, a potent bacterial endotoxin, can induce SerpinB2 expression via the toll-like receptor 4 (TLR4 by ∼1000-fold over a period of 24 hrs in murine macrophages. To map the LPS-regulated SerpinB2 promoter regions, we transfected reporter constructs driven by the ∼5 kb 5'-flanking region of the murine SerpinB2 gene and several deletion mutants into murine macrophages. In addition, we compared the DNA sequence of the murine 5' flanking sequence with the sequence of the human gene for homologous functional regulatory elements and identified several regulatory cis-acting elements in the human SERPINB2 promoter conserved in the mouse. Mutation analyses revealed that a CCAAT enhancer binding (C/EBP element, a cyclic AMP response element (CRE and two activator protein 1 (AP-1 response elements in the murine SerpinB2 proximal promoter are essential for optimal LPS-inducibility. Electrophoretic mobility shift (EMSA and chromatin immunoprecipitation (ChIP assays demonstrated that LPS induces the formation of C/EBP-β containing complexes with the SerpinB2 promoter. Importantly, both constitutive and LPS-induced SerpinB2 expression was severely abrogated in C/EBP-β-null mouse embryonic fibroblasts (MEFs and primary C/EBP-β-deficient peritoneal macrophages. Together, these data provide new insight into C/EBP-β-dependent regulation of inflammation-associated SerpinB2 expression.

  6. In vitro determination of the antibiotic susceptibility of biofilm-forming Pseudomonas aeruginosa and Staphylococcus aureus: possible role of proteolytic activity and membrane lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Masadeh MM

    2013-03-01

    Full Text Available Majed M Masadeh,1 Nizar M Mhaidat,2 Karem H Alzoubi,2 Emad I Hussein,3 Esra’a I Al-Trad41Department of Pharmaceutical Technology, 2Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan; 3Department of Biological Sciences, Yarmouk University, Irbid, Jordan; 4Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, JordanAbstract: We carried out a comprehensive overview of inhibitory effects of selected antibiotics on planktonic and biofilm cells of Staphylococcus aureus (ATCC 29213 and Pseudomonas aeruginosa (ATCC 27853 strains. The possible involvement of protease activity and the lipopolysaccharide (LPS profile of P. aeruginosa were also analyzed. Biofilm cells of both strains were more resistant to antibiotics than their planktonic counterparts. Protease activity was increased in both strains in the biofilm forms. Challenge with sublethal doses of antibiotics also increased proteolytic activity of biofilm cells. Additionally, the LPS profile of P. aeruginosa showed pattern alterations of the biofilm that can contribute to biofilm resistance and survival. These observations provide evidence for the involvement of bacterial proteolytic activity and LPS profile in the resistance of biofilm bacteria to antibiotics compared to their planktonic counterparts.Keywords: biofilm, Pseudomonas aeruginosa, Staphylococcus aureus, proteolytic activity, lipopolysaccharide

  7. Thalidomide protects mice against LPS-induced shock

    Directory of Open Access Journals (Sweden)

    Moreira A.L.

    1997-01-01

    Full Text Available Thalidomide has been shown to selectively inhibit TNF-a production in vitro by lipopolysaccharide (LPS-stimulated monocytes. TNF-a has been shown to play a pivotal role in the pathophysiology of endotoxic shock. Using a mouse model of LPS-induced shock, we investigated the effects of thalidomide on the production of TNF-a and other cytokines and on animal survival. After injection of 100-350 µg LPS into mice, cytokines including TNF-a, IL-6, IL-10, IL-1ß, GM-CSF and IFN-g were measured in the serum. Administration of 200 mg/kg thalidomide to mice before LPS challenge modified the profile of LPS-induced cytokine secretion. Serum TNF-a levels were reduced by 93%, in a dose-dependent manner, and TNF-a mRNA expression in the spleens of mice was reduced by 70%. Serum IL-6 levels were also inhibited by 50%. Thalidomide induced a two-fold increase in serum IL-10 levels. Thalidomide treatment did not interfere with the production of GM-CSF, IL-1ß or IFN-g. The LD50 of LPS in this model was increased by thalidomide pre-treatment from 150 µg to 300 µg in 72 h. Thus, at otherwise lethal doses of LPS, thalidomide treatment was found to protect animals from death

  8. Immunological properties of meningococcal lipopolysaccharide from serogroups A, B & C

    DEFF Research Database (Denmark)

    Jensen, T J; Kharazmi, A; Shand, G

    1996-01-01

    The aim of the study was to measure and compare the oxidative burst, chemotaxis and cytokine production of human white blood cells, stimulated with meningococcal lipopolysaccharides (LPS) extracted from three different serogroups (A, B and C) of Neisseria meningitidis, and to evaluate whether...

  9. Effects of various forms of lipopolysaccharide on the expression of ...

    African Journals Online (AJOL)

    Inflammation is an important event in the development of vascular diseases such as hypertension, atherosclerosis, and restenosis. The stimulation of lipopolysaccharide (LPS) from bacteria induces the release of critical proinflammatory cytokines that activate potent immune responses which may cause injury of cells in vivo ...

  10. Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China); Qiao, Juan, E-mail: qjuan@tsinghua.edu.cn [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Lu, Yun, E-mail: luyun@tsinghua.edu.cn [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China)

    2016-02-13

    Highlights: • Chlorination is effective to reduce the inflammation inducing capacity of LPS in lung. • LAL-detected endotoxin activity is not correlated to the potency of inflammation induction. • Alkyl chain of LPS was chlorinated in chlorination process. • LPS aggregate size decreases after chlorination. - Abstract: Lipopolysaccharide (LPS, also called endotoxin) is a pro-inflammatory constituent of gram negative bacteria and cyanobacteria, which causes a potential health risk in the process of routine urban application of reclaimed water, such as car wash, irrigation, scenic water refilling, etc. Previous studies indicated that the common disinfection treatment, chlorination, has little effect on endotoxin activity removal measured by Limulus amebocyte lysate (LAL) assay. However, in this study, significant decrease of acute inflammatory effects was observed in mouse lung, while LAL assay still presented a moderate increase of endotoxin activity. To explore the possible mechanisms, the nuclear magnetic resonance (NMR) results showed the chlorination happened in alkyl chain of LPS molecules, which could affect the interaction between LPS and LPS-binding protein. Also the size of LPS aggregates was found to drop significantly after treatment, which could be another results of chlorination caused polarity change. In conclusion, our observation demonstrated that chlorination is effective to reduce the LPS induced inflammation in lung, and it is recommended to use health effect-based methods to assess risk removal of water treatment technologies.

  11. Visualization and analysis of lipopolysaccharide distribution in binary phospholipid bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Henning, Maria Florencia [Instituto de Investigaciones Bioquimicas La Plata (INIBIOLP), CCT-La Plata, CONICET, Facultad de Ciencias Medicas, UNLP, Calles 60 y 120, 1900 La Plata (Argentina); Sanchez, Susana [Laboratory for Fluorescence Dynamics, University of California-Irvine, Irvine, CA (United States); Bakas, Laura, E-mail: lbakas@biol.unlp.edu.ar [Instituto de Investigaciones Bioquimicas La Plata (INIBIOLP), CCT-La Plata, CONICET, Facultad de Ciencias Medicas, UNLP, Calles 60 y 120, 1900 La Plata (Argentina); Departamento de Ciencias Biologicas, Facultad de Ciencias Exactas, UNLP, Calles 47 y 115, 1900 La Plata (Argentina)

    2009-05-22

    Lipopolysaccharide (LPS) is an endotoxin released from the outer membrane of Gram-negative bacteria during infections. It have been reported that LPS may play a role in the outer membrane of bacteria similar to that of cholesterol in eukaryotic plasma membranes. In this article we compare the effect of introducing LPS or cholesterol in liposomes made of dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine on the solubilization process by Triton X-100. The results show that liposomes containing LPS or cholesterol are more resistant to solubilization by Triton X-100 than the binary phospholipid mixtures at 4 {sup o}C. The LPS distribution was analyzed on GUVs of DPPC:DOPC using FITC-LPS. Solid and liquid-crystalline domains were visualized labeling the GUVs with LAURDAN and GP images were acquired using a two-photon microscope. The images show a selective distribution of LPS in gel domains. Our results support the hypothesis that LPS could aggregate and concentrate selectively in biological membranes providing a mechanism to bring together several components of the LPS-sensing machinery.

  12. Inhibition of Lipopolysaccharide-Induced Interleukin 8 in Human Adenocarcinoma Cell Line HT-29 by Spore Probiotics: B. coagulans and B. subtilis (natto).

    Science.gov (United States)

    Azimirad, Masoumeh; Alebouyeh, Masoud; Naji, Tahereh

    2017-03-01

    Probiotics are used as a treatment for different intestinal disorders. They confer health benefits by different ways. This study was aimed to investigate immunomodulatory effect of Bacillus probiotic spores on the production of lipopolysaccharide (LPS)-induced interleukin 8 (IL-8) in HT-29 intestinal epithelial cells. Differentiated intestinal epithelial cell line was used as a model for the study of colonization of purified spores (Bacillus subtilis (natto) and B. coagulans) and their anti-inflammatory effects. MTT assay and trypan blue staining were used for the detection of optimal concentration of the purified spores and LPS. Pre-treatment assay was done by treatment of the cells with the purified spores for 2 h, followed by challenges with LPS for 3 and 18 h. Post-treatment assay was done by initial treatment of the cells with LPS for 18 h, followed by the spores for 3 and 6 h. Levels of IL-8 secretion and its mRNA expression were measured by ELISA and relative Q real-time PCR. Our results showed similar rates of adherence to intestinal epithelial cells by the spore probiotics, while displaying no cytotoxic effect. In the pre-treatment assay, a significant decrease in IL-8, at both protein and mRNA levels, was measured for B. coagulans spores after the addition of LPS, which was higher than those observed for Bacillus subtilis (natto) spores. In the post-treatment assay, while Bacillus subtilis (but not B. coagulans) diminished the LPS-stimulated IL-8 levels after 3 h of incubation, the inhibitory effect was not constant. In conclusion, ability of Bacillus spore probiotics for adherence to intestinal epithelial cell and their anti-inflammatory effects, through interference with LPS/IL-8 signaling, was shown in this study. Further studies are needed to characterize responsible bacterial compounds associated with these effects.

  13. Lipopolysaccharide Structure and Biosynthesis in Helicobacter pylori.

    Science.gov (United States)

    Li, Hong; Liao, Tingting; Debowski, Aleksandra W; Tang, Hong; Nilsson, Hans-Olof; Stubbs, Keith A; Marshall, Barry J; Benghezal, Mohammed

    2016-12-01

    This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium which colonizes the luminal surface of the human gastric epithelium. Both a constitutive alteration of the lipid A preventing TLR4 elicitation and host mimicry of the Lewis antigen decorated O-antigen of H. pylori LPS promote immune escape and chronic infection. To date, the complete structure of H. pylori LPS is not available, and the proposed model is a linear arrangement composed of the inner core defined as the hexa-saccharide (Kdo-LD-Hep-LD-Hep-DD-Hep-Gal-Glc), the outer core composed of a conserved trisaccharide (-GlcNAc-Fuc-DD-Hep-) linked to the third heptose of the inner core, the glucan, the heptan and a variable O-antigen, generally consisting of a poly-LacNAc decorated with Lewis antigens. Although the glycosyltransferases (GTs) responsible for the biosynthesis of the H. pylori O-antigen chains have been identified and characterized, there are many gaps in regard to the biosynthesis of the core LPS. These limitations warrant additional mutagenesis and structural studies to obtain the complete LPS structure and corresponding biosynthetic pathway of this important gastric bacterium. © 2016 John Wiley & Sons Ltd.

  14. Potentiation of LPS-Induced Apoptotic Cell Death in Human Hepatoma HepG2 Cells by Aspirin via ROS and Mitochondrial Dysfunction: Protection by N-Acetyl Cysteine

    Science.gov (United States)

    Raza, Haider; John, Annie; Shafarin, Jasmin

    2016-01-01

    Cytotoxicity and inflammation-associated toxic responses have been observed to be induced by bacterial lipopolysaccharides (LPS) in vitro and in vivo respectively. Use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, has been reported to be beneficial in inflammation-associated diseases like cancer, diabetes and cardiovascular disorders. Their precise molecular mechanisms, however, are not clearly understood. Our previous studies on aspirin treated HepG2 cells strongly suggest cell cycle arrest and induction of apoptosis associated with mitochondrial dysfunction. In the present study, we have further demonstrated that HepG2 cells treated with LPS alone or in combination with aspirin induces subcellular toxic responses which are accompanied by increase in reactive oxygen species (ROS) production, oxidative stress, mitochondrial respiratory dysfunction and apoptosis. The LPS/Aspirin induced toxicity was attenuated by pre-treatment of cells with N-acetyl cysteine (NAC). Alterations in oxidative stress and glutathione-dependent redox-homeostasis were more pronounced in mitochondria compared to extra- mitochondrial cellular compartments. Pre-treatment of HepG2 cells with NAC exhibited a selective protection in redox homeostasis and mitochondrial dysfunction. Our results suggest that the altered redox metabolism, oxidative stress and mitochondrial function in HepG2 cells play a critical role in LPS/aspirin-induced cytotoxicity. These results may help in better understanding the pharmacological, toxicological and therapeutic properties of NSAIDs in cancer cells exposed to bacterial endotoxins. PMID:27441638

  15. Toll-like receptor 4 decoy, TOY, attenuates gram-negative bacterial sepsis.

    Directory of Open Access Journals (Sweden)

    Keehoon Jung

    Full Text Available Lipopolysaccharide (LPS, the Gram-negative bacterial outer membrane glycolipid, induces sepsis through its interaction with myeloid differentiation protein-2 (MD-2 and Toll-like receptor 4 (TLR4. To block interaction between LPS/MD-2 complex and TLR4, we designed and generated soluble fusion proteins capable of binding MD-2, dubbed TLR4 decoy receptor (TOY using 'the Hybrid leucine-rich repeats (LRR technique'. TOY contains the MD-2 binding ectodomain of TLR4, the LRR motif of hagfish variable lymphocyte receptor (VLR, and the Fc domain of IgG1 to make it soluble, productive, and functional. TOY exhibited strong binding to MD-2, but not to the extracellular matrix (ECM, resulting in a favorable pharmacokinetic profile in vivo. TOY significantly extended the lifespan, when administered in either preventive or therapeutic manners, in both the LPS- and cecal ligation/puncture-induced sepsis models in mice. TOY markedly attenuated LPS-triggered NF-kappaB activation, secretion of proinflammatory cytokines, and thrombus formation in multiple organs. Taken together, the targeting strategy for sequestration of LPS/MD-2 complex using the decoy receptor TOY is effective in treating LPS- and bacteria-induced sepsis; furthermore, the strategy used in TOY development can be applied to the generation of other novel decoy receptor proteins.

  16. MOLECULAR MODELING STUDY OF THE CONTRIBUTIONS OF SIDE AMINO ACID RESIDUES OF POLYMYXIN B3 TO ITS BINDING WITH E.COLI OUTER MEMBRANE LIPOPOLYSACCHARIDE

    Directory of Open Access Journals (Sweden)

    Lisnyak Yu. V.

    2014-12-01

    Full Text Available Last decades, antimicrobial peptides (AMPs are the subject of intense investigations aimed to develop effective drugs against extremely resistant nosocomial bacterial pathogens (especially Gram-negative bacteria. In particular, there has been greatly renewed interest to polymyxins, the representatives of AMPs which are specific and highly potent against Gram-negative bacteria, but have potential nephrotoxic side effect. A prerequisite of purposeful enhancement of therapeutic properties of polymyxins is a detailed knowledge of the molecular mechanisms of their interactions with cell targets. Lipopolysaccharide (LPS, the main component of the outer leaflet of outer membrane of gram-negative bacteria, is a primary cell target of polymyxins. The aim of the paper was to study the peculiarities of molecular interactions of polymyxin В3 with lipopolysaccharide of the outer membrane of gram-negative bacterium. Materials and methods The complexes of polymyxin В3 (PmВ3 and its alaninederivatives with E. coli outer membrane lipopolysaccharide were built and studied by molecular modeling methods (minimization, simulated annealing, docking. Atom coordinates of polymyxin В3 and LPS structures were taken from nuclear magnetic resonance and X-ray crystallography experiments, respectively. The AMBER03 force field was used with a 1.05 nm force cutoff. Longrange electrostatic interactions were treated by the Particle Mesh Ewald method. Results and discussion Alanine scanning of PmВ3 molecule has been carried out and the role of its side amino acid residues in the formation of complex with lipopolysaccharide has been investigated. It has been shown that substitutions of polymyxin’s Dab residues in positions 1, 3, 5, 8 and 9 for alanine markedly reduce the binding energy of PmB3-LPS complex, where as the similar substitutions of residues in positions 2, 6, 7 and 10 leave the binding energy virtually unchanged. Structural aspects of antimicrobial action of

  17. Dose dependency and individual variability in selected clinical, haematological and blood biochemical responses after systemic lipopolysaccharide challenge in cattle

    DEFF Research Database (Denmark)

    Jacobsen, Stine; Tølbøll, Trine; Andersen, Pia Haubro Fischer

    2005-01-01

    Previous studies have notede that susceptibility to systemic lipopolysaccharide (LPS) exposure seems to differ between individual cows. However, to date inter-individual variation in the existence or extent has never been backed up by statistical analyses.......Previous studies have notede that susceptibility to systemic lipopolysaccharide (LPS) exposure seems to differ between individual cows. However, to date inter-individual variation in the existence or extent has never been backed up by statistical analyses....

  18. Lipopolysaccharide-Induced Spatial Memory and Synaptic Plasticity Impairment Is Preventable by Captopril

    Directory of Open Access Journals (Sweden)

    Azam Abareshi

    2016-01-01

    Full Text Available Introduction. Renin-angiotensin system has a role in inflammation and also is involved in many brain functions such as learning, memory, and emotion. Neuroimmune factors have been proposed as the contributors to the pathogenesis of memory impairments. In the present study, the effect of captopril on spatial memory and synaptic plasticity impairments induced by lipopolysaccharide (LPS was investigated. Methods. The rats were divided and treated into control (saline, LPS (1 mg/kg, LPS-captopril (LPS-Capto; 50 mg/kg captopril before LPS, and captopril groups (50 mg/kg before saline. Morris water maze was done. Long-term potentiation (LTP from CA1 area of hippocampus was assessed by 100 Hz stimulation in the ipsilateral Schaffer collateral pathway. Results. In the LPS group, the spent time and traveled path to reach the platform were longer than those in the control, while, in the LPS-Capto group, they were shorter than those in the LPS group. Moreover, the slope and amplitude of field excitatory postsynaptic potential (fEPSP decreased in the LPS group, as compared to the control group, whereas, in the LPS-Capto group, they increased compared to the LPS group. Conclusion. The results of the present study showed that captopril improved the LPS-induced memory and LTP impairments induced by LPS in rats. Further investigations are required in order to better understand the exact responsible mechanism(s.

  19. Brucella abortus Induces the Premature Death of Human Neutrophils through the Action of Its Lipopolysaccharide.

    Science.gov (United States)

    Barquero-Calvo, Elías; Mora-Cartín, Ricardo; Arce-Gorvel, Vilma; de Diego, Juana L; Chacón-Díaz, Carlos; Chaves-Olarte, Esteban; Guzmán-Verri, Caterina; Buret, Andre G; Gorvel, Jean-Pierre; Moreno, Edgardo

    2015-05-01

    Most bacterial infections induce the activation of polymorphonuclear neutrophils (PMNs), enhance their microbicidal function, and promote the survival of these leukocytes for protracted periods of time. Brucella abortus is a stealthy pathogen that evades innate immunity, barely activates PMNs, and resists the killing mechanisms of these phagocytes. Intriguing clinical signs observed during brucellosis are the low numbers of Brucella infected PMNs in the target organs and neutropenia in a proportion of the patients; features that deserve further attention. Here we demonstrate that B. abortus prematurely kills human PMNs in a dose-dependent and cell-specific manner. Death of PMNs is concomitant with the intracellular Brucella lipopolysaccharide (Br-LPS) release within vacuoles. This molecule and its lipid A reproduce the premature cell death of PMNs, a phenomenon associated to the low production of proinflammatory cytokines. Blocking of CD14 but not TLR4 prevents the Br-LPS-induced cell death. The PMNs cell death departs from necrosis, NETosis and classical apoptosis. The mechanism of PMN cell death is linked to the activation of NADPH-oxidase and a modest but steadily increase of ROS mediators. These effectors generate DNA damage, recruitments of check point kinase 1, caspases 5 and to minor extent of caspase 4, RIP1 and Ca++ release. The production of IL-1β by PMNs was barely stimulated by B. abortus infection or Br-LPS treatment. Likewise, inhibition of caspase 1 did not hamper the Br-LPS induced PMN cell death, suggesting that the inflammasome pathway was not involved. Although activation of caspases 8 and 9 was observed, they did not seem to participate in the initial triggering mechanisms, since inhibition of these caspases scarcely blocked PMN cell death. These findings suggest a mechanism for neutropenia in chronic brucellosis and reveal a novel Brucella-host cross-talk through which B. abortus is able to hinder the innate function of PMN.

  20. Structural modifications of Helicobacter pylori lipopolysaccharide: An idea for how to live in peace

    Science.gov (United States)

    Chmiela, Magdalena; Miszczyk, Eliza; Rudnicka, Karolina

    2014-01-01

    In this review, we discuss the findings and concepts underlying the “persistence mechanisms” of Helicobacter pylori (H. pylori), a spiral-shaped, Gram-negative rod bacterium that was discovered as a gastric pathogen by Marshall and Warren in 1984. H. pylori colonizes the gastric mucosa of nearly half of the human population. Infections appear in early childhood and, if not treated, persist for life. The presence or absence of symptoms and their severity depend on multiple bacterial components, host susceptibility and environmental factors, which allow H. pylori to switch between pathogenicity and commensalism. Many studies have shown that H. pylori components may facilitate the colonization process and the immune response of the host during the course of H. pylori infection. These H. pylori-driven interactions might result from positive or negative modulation. Among the negative immunomodulators, a prominent position is occupied by a vacuolating toxin A (VacA) and cytotoxin-associated gene A (CagA) protein. However, in light of the recent studies that are presented in this review, it is necessary to enrich this panel with H. pylori lipopolysaccharide (LPS). Together with CagA and VacA, LPS suppresses the elimination of H. pylori bacteria from the gastric mucosa by interfering with the activity of innate and adaptive immune cells, diminishing the inflammatory response, and affecting the adaptive T lymphocyte response, thus facilitating the development of chronic infections. The complex strategy of H. pylori bacteria for survival in the gastric mucosa of the host involves both structural modifications of LPS lipid A to diminish its endotoxic properties and the expression and variation of Lewis determinants, arranged in O-specific chains of H. pylori LPS. By mimicking host components, this phenomenon leaves these bacteria “invisible” to immune cells. Together, these mechanisms allow H. pylori to survive and live for many years within their hosts. PMID:25110419

  1. Brucella abortus Induces the Premature Death of Human Neutrophils through the Action of Its Lipopolysaccharide

    Science.gov (United States)

    Barquero-Calvo, Elías; Mora-Cartín, Ricardo; Arce-Gorvel, Vilma; de Diego, Juana L.; Chacón-Díaz, Carlos; Chaves-Olarte, Esteban; Guzmán-Verri, Caterina; Buret, Andre G.; Gorvel, Jean-Pierre; Moreno, Edgardo

    2015-01-01

    Most bacterial infections induce the activation of polymorphonuclear neutrophils (PMNs), enhance their microbicidal function, and promote the survival of these leukocytes for protracted periods of time. Brucella abortus is a stealthy pathogen that evades innate immunity, barely activates PMNs, and resists the killing mechanisms of these phagocytes. Intriguing clinical signs observed during brucellosis are the low numbers of Brucella infected PMNs in the target organs and neutropenia in a proportion of the patients; features that deserve further attention. Here we demonstrate that B. abortus prematurely kills human PMNs in a dose-dependent and cell-specific manner. Death of PMNs is concomitant with the intracellular Brucella lipopolysaccharide (Br-LPS) release within vacuoles. This molecule and its lipid A reproduce the premature cell death of PMNs, a phenomenon associated to the low production of proinflammatory cytokines. Blocking of CD14 but not TLR4 prevents the Br-LPS-induced cell death. The PMNs cell death departs from necrosis, NETosis and classical apoptosis. The mechanism of PMN cell death is linked to the activation of NADPH-oxidase and a modest but steadily increase of ROS mediators. These effectors generate DNA damage, recruitments of check point kinase 1, caspases 5 and to minor extent of caspase 4, RIP1 and Ca++ release. The production of IL-1β by PMNs was barely stimulated by B. abortus infection or Br-LPS treatment. Likewise, inhibition of caspase 1 did not hamper the Br-LPS induced PMN cell death, suggesting that the inflammasome pathway was not involved. Although activation of caspases 8 and 9 was observed, they did not seem to participate in the initial triggering mechanisms, since inhibition of these caspases scarcely blocked PMN cell death. These findings suggest a mechanism for neutropenia in chronic brucellosis and reveal a novel Brucella-host cross-talk through which B. abortus is able to hinder the innate function of PMN. PMID:25946018

  2. Study of Nitric Oxide production by murine peritoneal macrophages induced by Brucella Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Kavoosi G

    2001-07-01

    Full Text Available Brueclla is a gram negative bacteria that causes Brucellosis. Lipopolysaccharide (LPS ", the pathogenic agent of Brucella is composed of O-chain, core oligosaccharide and lipid A. in addition, the structural and biological properties of different LPS extracted from different strains are not identical. The first defense system against LPS is nonspecific immunity that causes macrophage activation. Activated macrophages produce oxygen and nitrogen radicals that enhance the protection against intracellular pathogens.In this experiment LPS was extracted by hot phenol- water procedure and the effect of various LPSs on nitric oxide prodution by peritoneal mouse macrophages was examined.Our results demonstrated that the effect of LPS on nitric oxide production is concentration-dependent we observed the maximum response in concentration of 10-20 microgram per milliliter. Also our results demonstrate that LPS extracted from vaccine Brucella abortus (S 19 had a highe effect on nitric oxide production than the LPS from other strains

  3. Influence of dexamethasone and gamithromycin on the acute phase response in LPS-challenged calves

    OpenAIRE

    Plessers, Elke; Watteyn, Anneleen; Wyns, Heidi; Pardon, Bart; De Backer, Patrick; Croubels, Siska

    2012-01-01

    Introduction : Lipopolysaccharide (LPS) is a potent inducer of the bovine acute phase response and has been widely used in research to provoke acute inflammation. An intravenous challenge with LPS elicits the endogenous synthesis and release of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). These cytokines initiate fever and stimulate the hepatic production of acute phase proteins, such as Serum Amyloid A (SAA). Regarding the fact that immuno...

  4. Btk regulates macrophage polarization in response to lipopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Joan Ní Gabhann

    Full Text Available Bacterial Lipopolysaccharide (LPS is a strong inducer of inflammation and does so by inducing polarization of macrophages to the classic inflammatory M1 population. Given the role of Btk as a critical signal transducer downstream of TLR4, we investigated its role in M1/M2 induction. In Btk deficient (Btk (-\\- mice we observed markedly reduced recruitment of M1 macrophages following intraperitoneal administration of LPS. Ex vivo analysis demonstrated an impaired ability of Btk(-/- macrophages to polarize into M1 macrophages, instead showing enhanced induction of immunosuppressive M2-associated markers in response to M1 polarizing stimuli, a finding accompanied by reduced phosphorylation of STAT1 and enhanced STAT6 phosphorylation. In addition to STAT activation, M1 and M2 polarizing signals modulate the expression of inflammatory genes via differential activation of transcription factors and regulatory proteins, including NF-κB and SHIP1. In keeping with a critical role for Btk in macrophage polarization, we observed reduced levels of NF-κB p65 and Akt phosphorylation, as well as reduced induction of the M1 associated marker iNOS in Btk(-/- macrophages in response to M1 polarizing stimuli. Additionally enhanced expression of SHIP1, a key negative regulator of macrophage polarisation, was observed in Btk(-/- macrophages in response to M2 polarizing stimuli. Employing classic models of allergic M2 inflammation, treatment of Btk (-/- mice with either Schistosoma mansoni eggs or chitin resulted in increased recruitment of M2 macrophages and induction of M2-associated genes. This demonstrates an enhanced M2 skew in the absence of Btk, thus promoting the development of allergic inflammation.

  5. Lipopolysaccharide induces the migration of human dental pulp cells by up-regulating miR-146a.

    Science.gov (United States)

    Wang, Min-Ching; Hung, Pei-Shih; Tu, Hsi-Feng; Shih, Wen-Yu; Li, Wan-Chun; Chang, Kuo-Wei

    2012-12-01

    MicroRNAs are small noncoding RNAs that play crucial roles in regulating normal and pathologic functions. Bacterial lipopolysaccharide (LPS) is one of the key regulators of pulpal pathogenesis. This study investigated how LPS regulates microRNA expression and affects the phenotype of human dental pulp cells (DPCs). Primary DPCs were established and immortalized to achieve immortalized DPCs (I-DPCs). DPCs and I-DPCs were treated with LPS and examined to identify changes in microRNA expression, cell proliferation, and cell migration. Quantitative reverse-transcriptase polymerase chain reaction was used to detect changes in gene expression. Exogenous miR-146a expression was performed transfection with pre-mir-146a mimic. Knockdown of interleukin receptor-associated kinase (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) expression was performed by small interference oligonucleotide transfection. Western blot analysis was used to detect changes in the expression of the IRAK1 and TRAF6 proteins. The differentiation of DPCs was induced by osteogenic medium. I-DPCs had a higher level of human telomerase reverse transcriptase gene than the parental DPCs. Up-regulation of miR-146a expression and an increase in migration was induced by LPS treatment of DPCs and I-DPCs. Exogenous miR-146a expression increased the migration of DPCs and I-DPCs and down-regulated the expression of IRAK1 and TRAF6. Knockdown of IRAK1 and/or TRAF6 increased the migration of DPCs. The results suggested that LPS is able to increase the migration of DPCs by modulating the miR-146a-TRAF6/IRAK1 regulatory cascade. Copyright © 2012 American Association of Endodontists. All rights reserved.

  6. The Hydroalcoholic Extract Obtained from Mentha piperita L. Leaves Attenuates Oxidative Stress and Improves Survival in Lipopolysaccharide-Treated Macrophages

    Directory of Open Access Journals (Sweden)

    Mariana Oliveira Arruda

    2017-01-01

    Full Text Available Mentha piperita L. (peppermint possesses antimicrobial properties, but little is known of its ability to modulate macrophages. Macrophages are essential in bacterial infection control due to their antimicrobial functions and ability to link the innate and adaptive immune responses. We evaluated the effects of the peppermint leaf hydroalcoholic extract (LHAE on cultured murine peritoneal macrophages stimulated or not with lipopolysaccharide (LPS in vitro. Vehicle-treated cells were used as controls. The constituents of the extract were also identified. Epicatechin was the major compound detected in the LHAE. LPS-induced macrophage death was reversed by incubation with LHAE (1–30 μg/ml. Higher concentrations of the extract (≥100 μg/ml decreased macrophage viability (49–57% in the absence of LPS. LHAE (1–300 μg/ml attenuated H2O2 (34.6–53.4% but not nitric oxide production by these cells. At similar concentrations, the extract increased the activity of superoxide dismutase (15.3–63.5-fold and glutathione peroxidase (34.4–73.6-fold in LPS-treated macrophages. Only LPS-unstimulated macrophages presented enhanced phagocytosis (3.6–6.6-fold increase when incubated with LHAE (3–30 μg/ml. Overall, the LHAE obtained from peppermint modulates macrophage-mediated inflammatory responses, by stimulating the antioxidant pathway in these cells. These effects may be beneficial when the excessive activation of macrophages contributes to tissue damage during infectious disease.

  7. Combined effect of rifampicin-induced P-glycoprotein expression and lipopolysaccharide-induced intestinal sepsis on the effective permeability and pharmacokinetics of an anti-malarial candidate CDRI 97/78 in rats.

    Science.gov (United States)

    Singh, Yeshwant; Hidau, Mahendra Kumar; Krishna, Jampala; Singh, Shio Kumar

    2015-01-01

    1. The study aimed to investigate the influences on the pharmacokinetics (PK) of an anti-malarial drug 97/78 in rats pretreated with orally administered rifampicin and bacterial endotoxin lipopolysaccharide (LPS). 2. In-situ intestinal absorption studies were conducted on rats pretreated with rifampicin and LPS or both to estimate effective permeability (Peff) of 97/78. In-vivo studies were then conducted to explore 97/78 PK profile under these conditions. In-situ studies revealed that Peff value decreased to 64% (2.7 ± 0.6) × 10(-4 )cm/s in rats pretreated with rifampicin. This decrease was further enhanced very significantly to 4.5% (0.19 ± 0.03) × 10(-4 )cm/s in rats pretreated both with rifampicin and LPS (p97/78 in rifampicin-pretreated rats. This decrease was further augmented to 12-fold upon rifampicin and LPS pretreatment. 3. Orally administered rifampicin decreased the concentration of 97/78 in circulation. This decrease was further enhanced significantly to a very low level by LPS-induced intestinal sepsis.

  8. Computer simulation of uranyl uptake by the rough lipopolysaccharide membrane of Pseudomonas aeruginosa.

    Science.gov (United States)

    Lins, Roberto D; Vorpagel, Erich R; Guglielmi, Matteo; Straatsma, T P

    2008-01-01

    Heavy metal environmental contaminants cannot be destroyed but require containment, preferably in concentrated form, in a solid or immobile form for recycling or final disposal. Microorganisms are able to take up and deposit high levels of contaminant metals, including radioactive metals such as uranium and plutonium, into their cell wall. Consequently, these microbial systems are of great interest as the basis for potential environmental bioremediation technologies. The outer membranes of Gram-negative microbes are highly nonsymmetric and exhibit a significant electrostatic potential gradient across the membrane. This gradient has a significant effect on the uptake and transport of charged and dipolar compounds. However, the effectiveness of microbial systems for environmental remediation will depend strongly on specific properties that determine the uptake of targeted contaminants by a particular cell wall. To aid in the design of microbial remediation technologies, knowledge of the factors that determine the affinity of a particular bacterial outer membrane for the most common ionic species found in contaminated soils and groundwater is of great importance. Using our previously developed model for the lipopolysaccharide (LPS) membrane of Pseudomonas aeruginosa, this work presents the potentials of mean force as the estimate of the free energy profile for uptake of sodium, calcium, chloride, uranyl ions, and a water molecule by the bacterial LPS membrane. A compatible classical parameter set for uranyl has been developed and validated. Results show that the uptake of uranyl is energetically a favorable process relative to the other ions studied. At neutral pH, this nuclide is shown to be retained on the surface of the LPS membrane through chelation with the carboxyl and hydroxyl groups located in the outer core.

  9. Effect of gamma irradiation on chemical and biological properties of lipopolysaccharide from Salmonella typhimurium

    International Nuclear Information System (INIS)

    Naidu, Mamta D.; Chander, Ramesh; Nair, P.M.

    1998-01-01

    Lipopolysaccharide (LPS) from S. typhimurium on exposure to γ-radiation resulted in decrease in toxicity and was less mitogenic. Silver stained profiles of irradiated LPS on polyacrylamide gels revealed complete loss of its heteropolysaccharides which was confirmed further by analysing lipid A and LPS from Salmonella minnesota Re mutants on SDS-PAGE. Glucosamine and 2-keto 3-deoxy-octonate (Kdo) contents were significantly decreased on treatment. Lipid A obtained by removal of heteropolysaccharides from LPS was less toxic on exposure to gamma radiations. (author)

  10. Effect of ionizing radiation on macrophage stimulating property of Vibrio parahaemolyticus lipopolysaccharide

    International Nuclear Information System (INIS)

    Bandekar, J.R.; Nene, S.P.; Nerkar, D.P.

    1988-01-01

    Effect of gamma radiation on the macrophage stimulating ability of Vibrio parahaemolyticus lipopolysaccharide (LPS) was examined. Radiodetoxified LPS (RLPS) when injected (ip) in mice stimulated peritoneal macrophages as was evident from the enhancement of their acid hydrolases and cellular RNA contents. RLPS also stimulated the phagocytic activities of macrophages. The stimulation of macrophages was slightly less as compared to that observed with n ative LPS. Thus, treatment of LPS with 15 kGy dose of gamma radiation results in a slight reduction in its macrophage stimulating ability. (author). 3 tabs., 22 refs

  11. Berberine inhibits the LPS-induced proliferation and inflammatory response of stromal cells of adenomyosis tissues mediated by the LPS/TLR4 signaling pathway.

    Science.gov (United States)

    Liu, Li; Chen, Li; Jiang, Caixia; Guo, Jing; Xie, Yan; Kang, Le; Cheng, Zhongping

    2017-12-01

    A previous study by our group has demonstrated that lipopolysaccharide (LPS) induces adenomyosis through stimulating inflammatory cell proliferation and invasive growth of stromal cells via Toll-like receptor 4 (TLR4) signaling. The present study aimed to investigate the effects of berberine (BBR) on LPS-induced ectopic endometrial stromal cells (EESCs) isolated from patients with adenomyosis. The viability of EESCs treated with LPS or LPS plus BBR was detected by a cell counting kit-8 assay, and the cell cycle distribution and apoptosis were evaluated by flow cytometry. The effect of BBR on the expression of key molecules of inflammatory proliferation and invasive growth of LPS-induced EESCs was also evaluated. BBR significantly inhibited the LPS-induced proliferation of EESCs in a dose- and time-dependent manner. BBR induced cell cycle arrest in G0/G1 phase and enhanced apoptosis of LPS-induced EESCs. Furthermore, BBR inhibited the expression of interleukin (IL)-6, IL-8, transforming growth factor-β, epithelial growth factor, vascular endothelial growth factor and matrix metalloproteinase 2 in LPS-induced EESCs. To the best of our knowledge, the present study was the first to demonstrate that BBR has a protective effect on ameliorating the LPS-induced progression of adenomyosis. This result may provide a novel therapeutic strategy for the clinical treatment of the disease.

  12. Role of YadA, Ail, and Lipopolysaccharide in Serum Resistance of Yersinia enterocolitica Serotype O:3.

    Science.gov (United States)

    Biedzka-Sarek, Marta; Venho, Reija; Skurnik, Mikael

    2005-04-01

    Complement attack is a host strategy leading to elimination of pathogens. Yersinia enterocolitica expresses several potential complement resistance factors: the outer membrane proteins YadA and Ail as well as lipopolysaccharide (LPS). To study the contribution of these factors to the survival of Y. enterocolitica serotype O:3 in nonimmune human serum, we constructed 23 mutant strains of Y. enterocolitica O:3 expressing different combinations of YadA, Ail, LPS O antigen, and LPS outer core. Survival of bacteria was analyzed in normal serum (with functional classical, lectin, and alternative complement activation pathways) and EGTA-Mg-treated serum (only alternative pathway functional). Kinetic killing tests revealed that the most potent single-serum resistance factor needed for long-term survival was YadA; Ail was also indispensable, but it provided short-term survival and delayed the bacterial killing. On the contrary, the LPS O antigen and outer core, when in combination with YadA, Ail, or both, had a minor and often negative effect on serum resistance. Bacteria in the exponential phase of growth were more resistant to serum killing than stationary-phase bacteria. After exposing bacteria to EGTA-Mg-treated serum, O antigen could prevent deposition of covalently bound C3b on bacteria at 3 min of incubation, even as a single factor. At later time points (15 and 30 min) it had to be accompanied by YadA, Ail, and outer core. In normal serum, the bacteria were less resistant to C3b deposition. However, no direct correlation between the C3 deposition pattern and bacterial resistance was observed.

  13. Salmonella O48 Serum Resistance is Connected with the Elongation of the Lipopolysaccharide O-Antigen Containing Sialic Acid

    Directory of Open Access Journals (Sweden)

    Aleksandra Pawlak

    2017-09-01

    Full Text Available Complement is one of the most important parts of the innate immune system. Some bacteria can gain resistance against the bactericidal action of complement by decorating their outer cell surface with lipopolysaccharides (LPSs containing a very long O-antigen or with specific outer membrane proteins. Additionally, the presence of sialic acid in the LPS molecules can provide a level of protection for bacteria, likening them to human cells, a phenomenon known as molecular mimicry. Salmonella O48, which contains sialic acid in the O-antigen, is the major cause of reptile-associated salmonellosis, a worldwide public health problem. In this study, we tested the effect of prolonged exposure to human serum on strains from Salmonella serogroup O48, specifically on the O-antigen length. After multiple passages in serum, three out of four tested strains became resistant to serum action. The gas-liquid chromatography/tandem mass spectrometry analysis showed that, for most of the strains, the average length of the LPS O-antigen increased. Thus, we have discovered a link between the resistance of bacterial cells to serum and the elongation of the LPS O-antigen.

  14. Serum amyloid P component bound to gram-negative bacteria prevents lipopolysaccharide-mediated classical pathway complement activation

    NARCIS (Netherlands)

    de Haas, C. J.; van Leeuwen, E. M.; van Bommel, T.; Verhoef, J.; van Kessel, K. P.; van Strijp, J. A.

    2000-01-01

    Although serum amyloid P component (SAP) is known to bind many ligands, its biological function is not yet clear. Recently, it was demonstrated that SAP binds to lipopolysaccharide (LPS). In the present study, SAP was shown to bind to gram-negative bacteria expressing short types of LPS or

  15. Serum amyloid P component bound to gram-negative bacteria prevents lipopolysaccharide-mediated classical pathway complement activation

    NARCIS (Netherlands)

    de Haas, CJC; van Leeuwen, EMM; van Bommel, T; Verhoef, J; van Kessel, KPM; van Strijp, JAG

    Although serum amyloid P component (SAP) is known to bind many ligands, its biological function is not yet clear. Recently, it was demonstrated that SAP binds to lipopolysaccharide (LPS), In the present study, SAP was shown to bind to gram-negative bacteria expressing short types of LPS or

  16. Activity of Host Antimicrobials against Multidrug-Resistant Acinetobacter baumannii Acquiring Colistin Resistance through Loss of Lipopolysaccharide

    OpenAIRE

    García-Quintanilla, Meritxell; Pulido, Marina R.; Moreno-Martínez, Patricia; Martín-Peña, Reyes; López-Rojas, Rafael; Pachón, Jerónimo; McConnell, Michael J.

    2014-01-01

    Acinetobacter baumannii can acquire resistance to the cationic peptide antibiotic colistin through complete loss of lipopolysaccharide (LPS) expression. The activities of the host cationic antimicrobials LL-37 and human lysozyme against multidrug-resistant clinical isolates of A. baumannii that acquired colistin resistance through lipopolysaccharide loss were characterized. We demonstrate that LL-37 has activity against strains lacking lipopolysaccharide that is similar to that of their colis...

  17. Effects of alliin on LPS-induced acute lung injury by activating PPARγ.

    Science.gov (United States)

    Wang, Yi-Luan; Guo, Xian-Yang; He, Wei; Chen, Ru-Jie; Zhuang, Rong

    2017-09-01

    Alliin is a garlic organosulfur compound that possesses various pharmacological properties. In the present study, the protective effects and molecular mechanism of alliin on Lipopolysaccharides (LPS)-induced acute lung injury (ALI) were analyzed. LPS-induced ALI was induced in BALB/c mice by intranasal instillation of LPS. Alliin was administered intraperitoneally to mice 1 h after LPS treatment. The results showed that alliin markedly inhibited lung myeloperoxidase (MPO) activity and wet/dry (W/D) ratio induced by LPS. Alliin also inhibited TNF-α and IL-1β in the bronchoalveolar lavage fluid (BALF) induced by LPS. Furthermore, LPS-induced lung pathological injury was attenuated by treatment of alliin. LPS-induced NF-κB activation was significantly inhibited by alliin. In addition, the expression of peroxisome proliferator-activated receptor γ (PPARγ) was up-regulated by treatment of alliin. Taken together, these results suggested that alliin protected against LPS-induced ALI by activating PPARγ, which subsequently inhibited LPS-induced NF-κB activation and inflammatory response. Alliin might be used as an anti-inflammatory agent in the treatment of ALI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Glucocorticoid augments lipopolysaccharide-induced activation of the IκBζ-dependent genes encoding the anti-microbial glycoproteins lipocalin 2 and pentraxin 3.

    Science.gov (United States)

    Yamazaki, Soh; Akira, Shizuo; Sumimoto, Hideki

    2015-05-01

    Bacterial lipopolysaccharide (LPS), one of the most potent inducers of inflammation, activates the transcription factor NF-κB to induce expression of both proinflammatory mediators and anti-microbial glycoproteins such as lipocalin 2 (Lcn2) and pentraxin 3 (PTX3) in macrophages. Glucocorticoids are known to inhibit LPS-induced expression of proinflammatory cytokines via glucocorticoid receptor (GR)-mediated transrepression of NF-κB, whereas their effect on induction of anti-microbial effectors has remained to be elucidated. Here we show that the synthetic glucocorticoid dexamethasone (Dex) strongly enhances LPS-induced transcription of Lcn2 and Ptx3, although Dex by itself fails to trigger their transcription. In macrophages deficient in IκBζ (an inducible coactivator of NF-κB), Lcn2 and Ptx3 are not activated by LPS either alone or in combination with Dex. Association of GR as well as Brg1 (a subunit of the chromatin remodelling Swi/Snf complex) with a functional glucocorticoid response element in Lcn2 requires both the costimulation with LPS and the presence of IκBζ. Although Ptx3 does not contain the element, LPS induces recruitment of Dex-liganded GR to NF-κB-binding sites in regulatory regions of Ptx3, an event that does not occur in IκBζ-deficient macrophages. Thus glucocorticoids likely regulate infection-induced inflammation by increasing anti-microbial effectors in an IκBζ-dependent manner, while repressing proinflammatory genes. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  19. LPS Catch and Effort Estimation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected from the LPS dockside (LPIS) and the LPS telephone (LPTS) surveys are combined to produce estimates of total recreational catch, landings, and fishing...

  20. SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ae Sin; Jung, Yu Jin; Kim, Dal; Nguyen-Thanh, Tung [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kang, Kyung Pyo [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Research Institute of Clinical Medicine of Chonbuk National University, Chonbuk National University Hospital, Jeonju (Korea, Republic of); Lee, Sik [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Park, Sung Kwang [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Research Institute of Clinical Medicine of Chonbuk National University, Chonbuk National University Hospital, Jeonju (Korea, Republic of); Kim, Won, E-mail: kwon@jbnu.ac.kr [Department of Internal Medicine, Chonbuk National University Medical School, Jeonju (Korea, Republic of); Research Institute of Clinical Medicine of Chonbuk National University, Chonbuk National University Hospital, Jeonju (Korea, Republic of)

    2014-08-08

    Highlights: • Knockout of SIRT2 attenuates lipopolysaccharide-induced iNOS expression. • Lipopolysaccharide-induced NO production is decreased in SIRT2 KO macrophage. • SIRT2 deficiency suppresses lipopolysaccharide-induced ROS production in macrophage. • M1-macrophage related factors are decreased in SIRT2 deficient cells. • SIRT2 deficiency decreases lipopolysaccharide-induced activation of NFκB. - Abstract: Introduction: SIRT2 is a NAD(+)-dependent deacetylases and associated with numerous processes such as infection, carcinogenesis, DNA damage and cell cycle regulation. However, the role of SIRT2 in inflammatory process in macrophage remains unclear. Materials and methods: In the present study, we have evaluated the regulatory effects of SIRT2 in lipopolysaccharide (LPS)-stimulated macrophages isolated from SIRT2 knockout (KO) and wild type (WT) mice or Raw264.7 macrophage cells. As inflammatory parameters, expression of inducible nitric oxide synthase (iNOS), the productions of nitric oxide, reactive oxygen species (ROS) and M1-macrophage-related factors were evaluated. We also examined the effects of SIRT2 on activation of nuclear factor-kappaB (NFκB) signaling. Results: SIRT2 deficiency inhibits LPS-induced iNOS mRNA and protein expression in bone marrow derived macrophages. SIRT2-siRNA transfection also suppressed LPS-induced iNOS expression in Raw264.7 macrophage cells. Bone marrow derived macrophages isolated from SIRT2 KO mice produced lower nitric oxide and expressed lower levels of M1-macrophage related markers including iNOS and CD86 in response to LPS than WT mice. Decrease of SIRT2 reduced the LPS-induced reactive oxygen species production. Deficiency of SIRT2 resulted in inhibition of NFκB activation through reducing the phosphorylation and degradation of IκBα. The phosphorylation and nuclear translocation of p65 was significantly decreased in SIRT2-deficient macrophages after LPS stimulation. Discussion: Our data suggested that

  1. The LPS trigger system

    International Nuclear Information System (INIS)

    Benotto, F.; Costa, M.; Staiano, A.; Zampieri, A.; Bollito, M.; Isoardi, P.; Pernigotti, E.; Sacchi, R.; Trapani, P.P.; Larsen, H.; Massam, T.; Nemoz, C.

    1996-03-01

    The Leading Proton Spectrometer (LPS) has been equipped with microstrip silicon detectors specially designed to trigger events with high values of x L vertical stroke anti p' p vertical stroke / vertical stroke anti p p vertical stroke ≥0.95 where vertical stroke anti p' p vertical stroke and vertical stroke anti p p vertical stroke are respectively the momenta of outgoing and incoming protons. The LPS First Level Trigger can provide a clear tag for very high momentum protons in a kinematical region never explored before. In the following we discuss the physics motivation in tagging very forward protons and present a detailed description of the detector design, the front end electronics, the readout electronics, the Monte Carlo simulation and some preliminary results from 1995 data taking. (orig.)

  2. Crystal twinning of human MD-2 recognizing endotoxin cores of lipopolysaccharide

    International Nuclear Information System (INIS)

    Ohto, Umeharu; Satow, Yoshinori

    2008-01-01

    Twinned crystals of humaan MD-2 are transformed into single crystals with cryoprotectant optimization. Twinning of crystals causes overlapping of two or more reciprocal lattice points, and hence structure amplitudes for a single crystalline domain are hardly obtained from X-ray diffraction intensities. MD-2 protein forms a stable complex with Toll-like receptor 4 and recognizes bacterial lipopolysaccharide (LPS). Excessive immune responses activated by LPS cause septic shocks. Saccharide-trimmed human MD-2 crystallizes in the tetragonal form with apparent Laue symmetry of 4/mmm, and diffraction intensities from these crystals indicate crystal twinning. The crystal consists of two different domains, A and B. The c A axis of domain A coincides with the c B axis of domain B with a smaller lattice, and the a A axis corresponds to the (a B + b B ) axis. This twinning severely imposes difficulty in structure determination. Through optimization of cryoprotectant, domain A was thoroughly transformed into domain B. The crystal containing only domain B is in space group P4 1 2 1 2 with one MD-2 molecule in the asymmetric unit. The structure of this form of MD-2 as well as its complex with antiendotoxic lipid IVa was successfully determined using the multiple isomorphous replacement method

  3. Differential inflammatory response to inhaled lipopolysaccharide targeted either to the airways or the alveoli in man.

    Directory of Open Access Journals (Sweden)

    Winfried Möller

    Full Text Available Endotoxin (Lipopolysaccharide, LPS is a potent inducer of inflammation and there is various LPS contamination in the environment, being a trigger of lung diseases and exacerbation. The objective of this study was to assess the time course of inflammation and the sensitivities of the airways and alveoli to targeted LPS inhalation in order to understand the role of LPS challenge in airway disease.In healthy volunteers without any bronchial hyperresponsiveness we targeted sequentially 1, 5 and 20 µg LPS to the airways and 5 µg LPS to the alveoli using controlled aerosol bolus inhalation. Inflammatory parameters were assessed during a 72 h time period. LPS deposited in the airways induced dose dependent systemic responses with increases of blood neutrophils (peaking at 6 h, Interleukin-6 (peaking at 6 h, body temperature (peaking at 12 h, and CRP (peaking at 24 h. 5 µg LPS targeted to the alveoli caused significantly stronger effects compared to 5 µg airway LPS deposition. Local responses were studied by measuring lung function (FEV(1 and reactive oxygen production, assessed by hydrogen peroxide (H(2O(2 in fractionated exhaled breath condensate (EBC. FEV(1 showed a dose dependent decline, with lowest values at 12 h post LPS challenge. There was a significant 2-fold H(2O(2 induction in airway-EBC at 2 h post LPS inhalation. Alveolar LPS targeting resulted in the induction of very low levels of EBC-H(2O(2.Targeting LPS to the alveoli leads to stronger systemic responses compared to airway LPS targeting. Targeted LPS inhalation may provide a novel model of airway inflammation for studying the role of LPS contamination of air pollution in lung diseases, exacerbation and anti-inflammatory drugs.

  4. Plant Polyphenols and Exendin-4 Prevent Hyperactivity and TNF-α Release in LPS-Treated In vitro Neuron/Astrocyte/Microglial Networks

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    Francesca Gullo

    2017-09-01

    Full Text Available Increasing evidence supports a decisive role for neuroinflammation in the neurodegenerative process of several central nervous system (CNS disorders. Microglia are essential mediators of neuroinflammation and can regulate a broad spectrum of cellular responses by releasing reactive oxygen intermediates, nitric oxide, proteases, excitatory amino acids, and cytokines. We have recently shown that also in ex-vivo cortical networks of neurons, astrocytes and microglia, an increased level of tumor necrosis factor-alpha (TNF-α was detected a few hours after exposure to the bacterial endotoxin lipopolysaccharide (LPS. Simultaneously, an atypical “seizure-like” neuronal network activity was recorded by multi-electrode array (MEA electrophysiology. These effects were prevented by minocycline, an established anti-inflammatory antibiotic. We show here that the same inhibitory effect against LPS-induced neuroinflammation is exerted also by natural plant compounds, polyphenols, such as curcumin (CU, curcuma longa, crocin (CR, saffron, and resveratrol (RE, grape, as well as by the glucagon like peptide-1 receptor (GLP-1R agonist exendin-4 (EX-4. The drugs tested also caused per-se early transient (variable changes of network activity. Since it has been reported that LPS-induced neuroinflammation causes rearrangements of glutamate transporters in astrocytes and microglia, we suggest that neural activity could be putatively increased by an imbalance of glial glutamate transporter activity, leading to prolonged synaptic glutamatergic dysregulation.

  5. Genetic mechanisms of Coxiella burnetii lipopolysaccharide phase variation.

    Science.gov (United States)

    Beare, Paul A; Jeffrey, Brendan M; Long, Carrie M; Martens, Craig M; Heinzen, Robert A

    2018-03-01

    Coxiella burnetii is an intracellular pathogen that causes human Q fever, a disease that normally presents as a severe flu-like illness. Due to high infectivity and disease severity, the pathogen is considered a risk group 3 organism. Full-length lipopolysaccharide (LPS) is required for full virulence and disease by C. burnetii and is the only virulence factor currently defined by infection of an immunocompetent animal. Transition of virulent phase I bacteria with smooth LPS, to avirulent phase II bacteria with rough LPS, occurs during in vitro passage. Semi-rough intermediate forms are also observed. Here, the genetic basis of LPS phase conversion was investigated to obtain a more complete understanding of C. burnetii pathogenesis. Whole genome sequencing of strains producing intermediate and/or phase II LPS identified several common mutations in predicted LPS biosynthesis genes. After passage in broth culture for 30 weeks, phase I strains from different genomic groups exhibited similar phase transition kinetics and elevation of mutations in LPS biosynthesis genes. Targeted mutagenesis and genetic complementation using a new C. burnetii nutritional selection system based on lysine auxotrophy confirmed that six of the mutated genes were necessary for production of phase I LPS. Disruption of two of these genes in a C. burnetii phase I strain resulted in production of phase II LPS, suggesting inhibition of the encoded enzymes could represent a new therapeutic strategy for treatment of Q fever. Additionally, targeted mutagenesis of genes encoding LPS biosynthesis enzymes can now be used to construct new phase II strains from different genomic groups for use in pathogen-host studies at a risk group 2 level.

  6. Impact of training status on LPS-induced acute inflammation in humans

    DEFF Research Database (Denmark)

    Olesen, Jesper; Biensø, Rasmus Sjørup; Meinertz, S.

    2015-01-01

    The aim of the present study was to examine the impact of training status on the ability to induce a lipopolysaccharide (LPS)-induced inflammatory response systemically as well as in skeletal muscle (SkM) and adipose tissue (AT) in human subjects. Methods: Seventeen young (23.8 ± 2.5 years of age...

  7. Heat production, respiratory quotient, and methane loss subsequent to LPS challenge in beef heifers

    Science.gov (United States)

    Respiration calorimetry was used to measure energy utilization during an acute phase response (APR) to lipopolysaccharide (LPS). Eight Angus heifers (208 +/- 29.2 kg) were randomly assigned to one of two calorimeters in four 2-day periods for measurement of heat production (HP), methane (CH4), and r...

  8. LPS-Enhanced Glucose-Stimulated Insulin Secretion Is Normalized by Resveratrol

    DEFF Research Database (Denmark)

    Nøhr, Mark K; Dudele, Anete; Poulsen, Morten M

    2016-01-01

    UNLABELLED: Low-grade inflammation is seen with obesity and is suggested to be a mediator of insulin resistance. The eliciting factor of low-grade inflammation is unknown but increased permeability of gut bacteria-derived lipopolysaccharides (LPS) resulting in endotoxemia could be a candidate. He...

  9. Aggravation of myocardial dysfunction by injurious mechanical ventilation in LPS-induced pneumonia in rats

    NARCIS (Netherlands)

    Smeding, Lonneke; Kuiper, Jan Willem; Plotz, Frans B.; Kneyber, Martin C. J.; Groeneveld, A. B. Johan

    2013-01-01

    Background: Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI) and may thereby contribute to fatal multiple organ failure. We tested the hypothesis that injurious MV of lipopolysaccharide (LPS) pre-injured lungs induces myocardial inflammation and further dysfunction ex

  10. The Neurokinin-1 Receptor Contributes to the Early Phase of Lipopolysaccharide-Induced Fever via Stimulation of Peripheral Cyclooxygenase-2 Protein Expression in Mice

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    Eszter Pakai

    2018-02-01

    Full Text Available Neurokinin (NK signaling is involved in various inflammatory processes. A common manifestation of systemic inflammation is fever, which is usually induced in animal models with the administration of bacterial lipopolysaccharide (LPS. A role for the NK1 receptor was shown in LPS-induced fever, but the underlying mechanisms of how the NK1 receptor contributes to febrile response, especially in the early phase, have remained unknown. We administered LPS (120 µg/kg, intraperitoneally to mice with the Tacr1 gene, i.e., the gene encoding the NK1 receptor, either present (Tacr1+/+ or absent (Tacr1−/− and measured their thermoregulatory responses, serum cytokine levels, tissue cyclooxygenase-2 (COX-2 expression, and prostaglandin (PG E2 concentration. We found that the LPS-induced febrile response was attenuated in Tacr1−/− compared to their Tacr1+/+ littermates starting from 40 min postinfusion. The febrigenic effect of intracerebroventricularly administered PGE2 was not suppressed in the Tacr1−/− mice. Serum concentration of pyrogenic cytokines did not differ between Tacr1−/− and Tacr1+/+ at 40 min post-LPS infusion. Administration of LPS resulted in amplification of COX-2 mRNA expression in the lungs, liver, and brain of the mice, which was statistically indistinguishable between the genotypes. In contrast, the LPS-induced augmentation of COX-2 protein expression was attenuated in the lungs and tended to be suppressed in the liver of Tacr1−/− mice compared with Tacr1+/+ mice. The Tacr1+/+ mice responded to LPS with a significant surge of PGE2 production in the lungs, whereas Tacr1−/− mice did not. In conclusion, the NK1 receptor is necessary for normal fever genesis. Our results suggest that the NK1 receptor contributes to the early phase of LPS-induced fever by enhancing COX-2 protein expression in the periphery. These findings advance the understanding of the crosstalk between NK signaling and the “cytokine-COX-2

  11. Guillain-Barré syndrome- and Miller Fisher syndrome-associated Campylobacter jejuni lipopolysaccharides induce anti-GM1 and anti-GQ1b Antibodies in rabbits.

    NARCIS (Netherlands)

    M.A. de Klerk; H.P. Endtz (Hubert); B.C. Jacobs (Bart); J.D. Laman (Jon); F.G.A. van der Meché (Frans); P.A. van Doorn (Pieter); C.W. Ang (Wim)

    2001-01-01

    textabstractCampylobacter jejuni infections are thought to induce antiganglioside antibodies in patients with Guillain-Barre syndrome (GBS) and Miller Fisher syndrome (MFS) by molecular mimicry between C. jejuni lipopolysaccharides (LPS) and gangliosides. We used

  12. Lipopolysaccharide from Burkholderia thailandensis E264 provides protection in a murine model of melioidosis.

    Science.gov (United States)

    Ngugi, Sarah A; Ventura, Valeria V; Qazi, Omar; Harding, Sarah V; Kitto, G Barrie; Estes, D Mark; Dell, Anne; Titball, Richard W; Atkins, Timothy P; Brown, Katherine A; Hitchen, Paul G; Prior, Joann L

    2010-11-03

    Burkholderia thailandensis is a less virulent close relative of Burkholderia pseudomallei, a CDC category B biothreat agent. We have previously shown that lipopolysaccharide (LPS) extracted from B. pseudomallei can provide protection against a lethal challenge of B. pseudomallei in a mouse model of melioidosis. Sugar analysis on LPS from B. thailandensis strain E264 confirmed that this polysaccharide has a similar structure to LPS from B. pseudomallei. Mice were immunised with LPS from B. thailandensis or B. pseudomallei and challenged with a lethal dose of B. pseudomallei strain K96243. Similar protection levels were observed when either LPS was used as the immunogen. This data suggests that B. thailandensis LPS has the potential to be used as part of a subunit based vaccine against pathogenic B. pseudomallei. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  13. Dynamic lipopolysaccharide transfer cascade to TLR4/MD2 complex via LBP and CD14.

    Science.gov (United States)

    Kim, Soo Jin; Kim, Ho Min

    2017-02-01

    Toll-like receptor 4 (TLR4) together with MD2, one of the key pattern recognition receptors for a pathogen-associated molecular pattern, activates innate immunity by recognizing lipopolysaccharide (LPS) of Gram-negative bacteria. Although LBP and CD14 catalyze LPS transfer to the TLR4/MD2 complex, the detail mechanisms underlying this dynamic LPS transfer remain elusive. Using negative-stain electron microscopy, we visualized the dynamic intermediate complexes during LPS transfer-LBP/LPS micelles and ternary CD14/LBP/LPS micelle complexes. We also reconstituted the entire cascade of LPS transfer to TLR4/MD2 in a total internal reflection fluorescence (TIRF) microscope for a single molecule fluorescence analysis. These analyses reveal longitudinal LBP binding to the surface of LPS micelles and multi-round binding/unbinding of CD14 to single LBP/LPS micelles via key charged residues on LBP and CD14. Finally, we reveal that a single LPS molecule bound to CD14 is transferred to TLR4/MD2 in a TLR4-dependent manner. These discoveries, which clarify the molecular mechanism of dynamic LPS transfer to TLR4/MD2 via LBP and CD14, provide novel insights into the initiation of innate immune responses. [BMB Reports 2017; 50(2): 55-57].

  14. Chondroitin Sulfate-Rich Extract of Skate Cartilage Attenuates Lipopolysaccharide-Induced Liver Damage in Mice

    Science.gov (United States)

    Song, Yeong Ok; Kim, Mijeong; Woo, Minji; Baek, Jang-Mi; Kang, Keon-Hee; Kim, Sang-Ho; Roh, Seong-Soo; Park, Chan Hum; Jeong, Kap-Seop; Noh, Jeong-Sook

    2017-01-01

    The protective effects of a chondroitin sulfate-rich extract (CSE) from skate cartilage against lipopolysaccharide (LPS)-induced hepatic damage were investigated, and its mechanism of action was compared with that of chondroitin sulfate (CS) from shark cartilage. ICR mice were orally administrated 200 mg/kg body weight (BW) of CS or 400 mg/kg BW of CSE for 3 consecutive days, followed by a one-time intraperitoneal injection of LPS (20 mg/kg BW). The experimental groups were vehicle treatment without LPS injection (NC group), vehicle treatment with LPS injection (LPS group), CS pretreatment with LPS injection (CS group), and CSE pretreatment with LPS injection (CSE group). Hepatic antioxidant enzyme expression levels in the CS and CSE groups were increased relative to those in the LPS group. In LPS-insulted hepatic tissue, inflammatory factors were augmented relative to those in the NC group, but were significantly suppressed by pretreatment with CS or CSE. Moreover, CS and CSE alleviated the LPS-induced apoptotic factors and mitogen-activated protein kinase (MAPK). In addition, CS and CSE effectively decreased the serum lipid concentrations and downregulated hepatic sterol regulatory element-binding proteins expression. In conclusion, the skate CSE could protect against LPS-induced hepatic dyslipidemia, oxidative stress, inflammation, and apoptosis, probably through the regulation of MAPK signaling. PMID:28617322

  15. Subversion of innate and adaptive immune activation induced by structurally modified lipopolysaccharide from Salmonella typhimurium.

    Science.gov (United States)

    Pastelin-Palacios, Rodolfo; Gil-Cruz, Cristina; Pérez-Shibayama, Christian I; Moreno-Eutimio, Mario A; Cervantes-Barragán, Luisa; Arriaga-Pizano, Lourdes; Ludewig, Burkhard; Cunningham, Adam F; García-Zepeda, Eduardo A; Becker, Ingeborg; Alpuche-Aranda, Celia; Bonifaz, Laura; Gunn, John S; Isibasi, Armando; López-Macías, Constantino

    2011-08-01

    Salmonella are successful pathogens that infect millions of people every year. During infection, Salmonella typhimurium changes the structure of its lipopolysaccharide (LPS) in response to the host environment, rendering bacteria resistant to cationic peptide lysis in vitro. However, the role of these structural changes in LPS as in vivo virulence factors and their effects on immune responses and the generation of immunity are largely unknown. We report that modified LPS are less efficient than wild-type LPS at inducing pro-inflammatory responses. The impact of this LPS-mediated subversion of innate immune responses was demonstrated by increased mortality in mice infected with a non-lethal dose of an attenuated S. typhimurium strain mixed with the modified LPS moieties. Up-regulation of co-stimulatory molecules on antigen-presenting cells and CD4(+) T-cell activation were affected by these modified LPS. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing specific antibody responses. Immunization with modified LPS moiety preparations combined with experimental antigens, induced an impaired Toll-like receptor 4-mediated adjuvant effect. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing immunity against challenge with virulent S. typhimurium. Hence, changes in S. typhimurium LPS structure impact not only on innate immune responses but also on both humoral and cellular adaptive immune responses. © 2011 The Authors. Immunology © 2011 Blackwell Publishing Ltd.

  16. Leptin Downregulates LPS-Induced Lung Injury: Role of Corticosterone and Insulin

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    Maristella A. Landgraf

    2014-03-01

    Full Text Available Background/Aims: We investigated the effects of leptin in the development of lipopolysaccharide (LPS-induced acute lung inflammation (ALI in lean mice. Methods: Mice were administered leptin (1.0µg/g or leptin (1.0µg/g followed by LPS (1.5µg/g intranasally. Additionally, some animals were given LPS (1.5µg/g or saline intranasally alone, as a control. Tissue samples and fluids were collected six hours after instillation. Results: We demonstrated that leptin alone did not induce any injury. Local LPS exposure resulted in significant acute lung inflammation, characterized by a substantial increase in total cells, mainly neutrophils, in bronchoalveolar lavages (BAL. We also observed a significant lymphocyte influx into the lungs associated with enhanced lung expression of chemokines and cytokines (KC, RANTES, TNF-α, IFN-γ, GM-CSF and VEGF. LPS-induced ALI was characterized by the enhanced expression of ICAM-1 and iNOS in the lungs. Mice that received LPS showed an increase in insulin levels. Leptin, when administered prior to LPS instillation, abolished all of these effects. LPS induced an increase in corticosterone levels, and leptin potentiated this event. Conclusion: These data suggest that exogenous leptin may promote protection during sepsis, and downregulation of the insulin levels and upregulation of corticosterone may be important mechanisms in the amelioration of LPS-induced ALI.

  17. RAGE Plays a Role in LPS-Induced NF-κB Activation and Endothelial Hyperpermeability

    Science.gov (United States)

    Wang, Liqun; Wu, Jie; Guo, Xiaohua; Huang, Xuliang; Huang, Qiaobing

    2017-01-01

    Endothelial functional dysregulation and barrier disruption contribute to the initiation and development of sepsis. The receptor for advanced glycation end products (RAGE) has been demonstrated to be involved in the pathogenesis of sepsis. The present study aimed to investigate the role of RAGE in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) activation in endothelial cells and the consequent endothelial hyperpermeability. LPS-induced upregulation of RAGE protein expression in human umbilical vein endothelial cells (HUVECs) was detected by western blotting. Activation of NF-κB was revealed using western blotting and immunofluorescent staining. LPS-elicited endothelial hyperpermeability was explored by transendothelial electrical resistance (TER) assay and endothelial monolayer permeability assay. The blocking antibody specific to RAGE was used to confirm the role of RAGE in LPS-mediated NF-κB activation and endothelial barrier disruption. We found that LPS upregulated the protein expression of RAGE in a dose- and time-dependent manner in HUVECs. Moreover, LPS triggered a significant phosphorylation and degradation of IκBα, as well as NF-κB p65 nuclear translocation. Moreover, we observed a significant increase in endothelial permeability after LPS treatment. However, the RAGE blocking antibody attenuated LPS-evoked NF-κB activation and endothelial hyperpermeability. Our results suggest that RAGE plays an important role in LPS-induced NF-κB activation and endothelial barrier dysfunction. PMID:28358333

  18. RAGE Plays a Role in LPS-Induced NF-κB Activation and Endothelial Hyperpermeability.

    Science.gov (United States)

    Wang, Liqun; Wu, Jie; Guo, Xiaohua; Huang, Xuliang; Huang, Qiaobing

    2017-03-30

    Endothelial functional dysregulation and barrier disruption contribute to the initiation and development of sepsis. The receptor for advanced glycation end products (RAGE) has been demonstrated to be involved in the pathogenesis of sepsis. The present study aimed to investigate the role of RAGE in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) activation in endothelial cells and the consequent endothelial hyperpermeability. LPS-induced upregulation of RAGE protein expression in human umbilical vein endothelial cells (HUVECs) was detected by western blotting. Activation of NF-κB was revealed using western blotting and immunofluorescent staining. LPS-elicited endothelial hyperpermeability was explored by transendothelial electrical resistance (TER) assay and endothelial monolayer permeability assay. The blocking antibody specific to RAGE was used to confirm the role of RAGE in LPS-mediated NF-κB activation and endothelial barrier disruption. We found that LPS upregulated the protein expression of RAGE in a dose- and time-dependent manner in HUVECs. Moreover, LPS triggered a significant phosphorylation and degradation of IκBα, as well as NF-κB p65 nuclear translocation. Moreover, we observed a significant increase in endothelial permeability after LPS treatment. However, the RAGE blocking antibody attenuated LPS-evoked NF-κB activation and endothelial hyperpermeability. Our results suggest that RAGE plays an important role in LPS-induced NF-κB activation and endothelial barrier dysfunction.

  19. Dose related effects of LPS on endometrial epithelial cell populations from dioestrus cows.

    Science.gov (United States)

    Chanrot, M; Guo, Y; Dalin, A M; Persson, E; Båge, R; Svensson, A; Gustafsson, H; Humblot, P

    2017-02-01

    Lipopolysaccharides (LPS) from Gram negative bacteria are involved in the pathogeny of uterine diseases in cows. This study aimed to investigate LPS effects on the growth of bovine endometrial epithelial cells (bEEC) and relationships between LPS response and tissue characteristics. Uteri from 35 females were characterized for parity and stage of oestrous cycle. Densities of glandular tissue (dGT), CD11b+ cells and Ki67+ cells were measured in the endometrial tissue. Cells from 13 dioestrus cows were exposed to 0, 2, 4, 8, 12, 16 or 24μg/mL LPS. Effects of parity and stage of the oestrous cycle on tissue characteristics and effects of LPS dosage, cow and tissue characteristics on changes in cell numbers were analyzed by ANOVA. The dGT was higher in metoestrus and dioestrus samples than in pro-oestrus ones whereas densities of CD11b+ and Ki67+ cells were higher at pro-oestrus (pLPS influenced bEEC populations in a dose related manner. An increase in number of live cells was observed for dosages ranging from 2 to 12μg/mL LPS (pLPS. To conclude this model is suitable for further studies on dysregulations induced by LPS in endometrial tissue. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Induction of heme oxygenase-1 attenuates lipopolysaccharide-induced cyclooxygenase-2 expression in mouse brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Yang Chuen-Mao

    2010-11-01

    Full Text Available Abstract Background Prostaglandin E2 (PGE2, an arachidonic acid metabolite converted by cyclooxygenase-2 (COX-2, plays important roles in the regulation of endothelial functions in response to bacterial infection. The enzymatic activity of COX-2 can be down-regulated by heme oxygenase-1 (HO-1 induction. However, the mechanisms underlying HO-1 modulating COX-2 protein expression are not known. Objective The aim of the present study was to investigate whether the up-regulation of HO-1 regulates COX-2 expression induced by lipopolysaccharide (LPS, an endotoxin produced by Gram negative bacteria, in mouse brain endothelial cells (bEnd.3 Methods Cultured bEnd.3 cells were used to investigate LPS-induced COX-2 expression and PGE2 production. Cobalt protoporphyrin IX (CoPP, an HO-1 inducer, infection with a recombinant adenovirus carried with HO-1 gene (Adv-HO-1, or zinc protoporphyrin (ZnPP, an HO-1 inhibitor was used to stimulate HO-1 induction or inhibit HO-1 activity. The expressions of COX-2 and HO-1 were evaluated by western blotting. PGE2 levels were detected by an enzyme-linked immunoassay. Hemoglobin (a chelator of carbon monoxide, CO, one of metabolites of HO-1 and CO-RM2 (a CO releasing molecule were used to investigate the mechanisms of HO-1 regulating COX-2 expression. Results We found that LPS-induced COX-2 expression and PGE2 production were mediated through NF-κB (p65 via activation of Toll-like receptor 4 (TLR4. LPS-induced COX-2 expression was inhibited by HO-1 induction by pretreatment with CoPP or infection with Adv-HO-1. This inhibitory effect of HO-1 was reversed by pretreatment with either ZnPP or hemoglobin. Pretreatment with CO-RM2 also inhibited TLR4/MyD88 complex formation, NF-κB (p65 activation, COX-2 expression, and PGE2 production induced by LPS. Conclusions We show here a novel inhibition of HO-1 on LPS-induced COX-2/PGE2 production in bEnd.3. Our results reinforce the emerging role of cerebral endothelium-derived HO-1

  1. LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

    Energy Technology Data Exchange (ETDEWEB)

    Russe, Otto Quintus, E-mail: quintus@russe.eu; Möser, Christine V., E-mail: chmoeser@hotmail.com; Kynast, Katharina L., E-mail: katharina.kynast@googlemail.com; King, Tanya S., E-mail: tanya.sarah.king@googlemail.com; Olbrich, Katrin, E-mail: Katrin.olbrich@gmx.net; Grösch, Sabine, E-mail: groesch@em.uni-frankfurt.de; Geisslinger, Gerd, E-mail: geisslinger@em.uni-frankfurt.de; Niederberger, Ellen, E-mail: e.niederberger@em.uni-frankfurt.de

    2014-05-09

    Highlights: • AMPK-activation induces caspase 3-dependent apoptosis in macrophages. • Apoptosis is associated with decreased mTOR and increased p21 levels. • All effects can be significantly inhibited by the TLR4 agonist lipopolysaccharide. - Abstract: AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have a therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner. In conclusion, our results revealed that AMPK activation is not only associated with positive effects but might also contribute to risk factors by disturbing important features of macrophages. The fact that LPS is able to restore AMPK-associated apoptosis might indicate an important role of TLR4 agonists in preventing unfavorable cell death of immune cells.

  2. Lipopolysaccharide induces IFN-γ production in human NK cells

    Directory of Open Access Journals (Sweden)

    Leonid M Kanevskiy

    2013-01-01

    Full Text Available NK cells have been shown to play a regulatory role in sepsis. According to the current view, NK cells become activated via macrophages or dendritic cells primed by lipopolysaccharide (LPS. Recently TLR4 gene expression was detected in human NK cells suggesting the possibility of a direct action of LPS on NK cells. In this study, effects of LPS on NK cell cytokine production and cytotoxicity were studied using highly purified human NK cells. LPS induced IFN-γ production in the presence of IL-2 in cell populations containing >98% CD56+ cells. Surprisingly, in the same experiments LPS decreased NK cell degranulation. No significant expression of markers related to blood dendritic cells, monocytes or T or B lymphocytes in the NK cell preparations was observed; the portions of HLA-DRbright, CD14+, CD3+ and CD20+ cells amounted to less than 0.1% within the cell populations. No more than 0.2% of NK cells were shown to be slightly positive for surface TLR4 in our experimental system, although intracellular staining revealed moderate amounts of TLR4 inside the NK cell population. These cells were negative for surface CD14, the receptor participating in LPS recognition by TLR4. Incubation of NK cells with IL-2 or/and LPS did not lead to an increase in TLR4 surface expression. TLR4–CD56+ NK cells isolated by cell sorting secreted IFN-γ in response to LPS. Antibody to TLR4 did not block the LPS-induced increase in IFN-γ production. We have also shown that Re-form of LPS lacking outer core oligosaccharide and O-antigen induces less cytokine production in NK cells than full length LPS. We speculate that the polysaccharide fragments of LPS molecule may take part in LPS-induced IFN-γ production by NK cells. Collectively our data suggest the existence of a mechanism of LPS direct action on NK cells distinct from established TLR4-mediated signaling.

  3. Mutations affecting lipopolysaccharide enhance ail-mediated entry of Yersinia enterocolitica into mammalian cells.

    Science.gov (United States)

    Pierson, D E

    1994-07-01

    Two genes of Yersinia enterocolitica, inv and ail, have been identified as having a role in the bacterial adherence to and entry into mammalian cells in vitro. Expression of both genes is regulated by temperature. In stationary phase, ail gene expression is detectable only in bacteria at 37 degrees C, not at lower temperatures. An inv mutant derivative of Y. enterocolitica, which cannot enter mammalian cells when grown at 30 degrees C because of the lack of both inv and ail gene products, was mutagenized with the transposons mini-Tn10 and Tn5B50 to look for an increase in Ail-mediated cell entry. Sixteen mutants that could enter tissue culture cells after growth at 30 degrees C were selected. All of the mutants had increased cell surface Ail levels as detected by an Ail-specific monoclonal antibody. All of the ten Tn5B50 and one of the six mini-Tn10 mutants showed no increase in ail expression, but they had alterations in their lipopolysaccharide (LPS) such that no O side chains were detectable in bacteria grown at 30 degrees C. Thus, these mutants that are increased in their ability to enter cells appear to be so as a result of a change in the LPS on the surface resulting in increased levels of Ail protein able to interact with the mammalian cell surface. In the remaining mini-Tn10 mutants, LPS is normal, and the increase in cell surface Ail levels appears to be due to an increase in ail mRNA present in the cell. These mutants may therefore be affecting a repressor of ail gene expression.

  4. Identification of five anti-lipopolysaccharide factors in oriental river prawn, Macrobrachium nipponense.

    Science.gov (United States)

    Wang, Yili; Tang, Ting; Gu, Jihai; Li, Xiang; Yang, Xue; Gao, Xiaobin; Liu, Fengsong; Wang, Jianhui

    2015-10-01

    Anti-lipopolysaccharide factors (ALFs) are a group of antimicrobial peptides (AMPs) with broad-spectrum antimicrobial activities and antiviral activities mainly found in crustaceans and horseshoe crabs. In the present study, we identified 5 ALF expression sequence tags (ESTs) through analysis of the established M. nipponense transcriptome, and cloned their full-length cDNA sequences using rapid amplification of cDNA ends (RACE) method. The 5 ALFs were designated as MnALF1-5, and all of them showed high similarity with their Macrobrachium rosenbergii homologs in the phylogenetic analyses, especially in LPS binding domains. In healthy adult prawns, we found the highest expression of MnALF2 and MnALF4 in haemocytes, and the highest expression of MnALF4 and MnALF3 in intestine. Some isoforms of MnALF were down-regulated but the majority was up-regulated in different prawn tissues upon Aeromonas hydrophila challenge. To conform the expected antimicrobial activities harbored in MnALFs' LPS binding domains, we used a synthesized peptide cMnALF24 that corresponds to the LPS binding domain of MnALF2 as a representative molecule for the antibacterial activity test, and found that cMnALF24 possessed strong and broad-spectrum antibacterial activity against Gram positive and Gram negative bacteria, but no inhibition activity against fungi; Meanwhile, in the hemolytic test, cMnALF24 showed weak hemolysis activities (around 10%) to the rabbit red blood cells at concentrations of 0.67-33.50 μM. This study provides insights into understanding the antibacterial function of ALFs in the innate immunity of freshwater prawn, and reports a peptide that can be a potential drug candidate with good efficacy against bacterial infection and low toxicity to host cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Heterogeneity in Tandem Octanucleotides within Haemophilus influenzae Lipopolysaccharide Biosynthetic Gene losA Affects Serum Resistance

    OpenAIRE

    Erwin, Alice L.; Bonthuis, Paul J.; Geelhood, Jennifer L.; Nelson, Kevin L.; McCrea, Kirk W.; Gilsdorf, Janet R.; Smith, Arnold L.

    2006-01-01

    Haemophilus influenzae is subject to phase variation mediated by changes in the length of simple sequence repeat regions within several genes, most of which encode either surface proteins or enzymes involved in the synthesis of lipopolysaccharides (LPS). The translational repeat regions that have been described thus far all consist of tandemly repeated tetranucleotides. We describe an octanucleotide repeat region within a putative LPS biosynthetic gene, losA. Approximately 20 percent of nonty...

  6. Bee venom ameliorates lipopolysaccharide-induced memory loss by preventing NF-kappaB pathway

    OpenAIRE

    Gu, Sun Mi; Park, Mi Hee; Hwang, Chul Ju; Song, Ho Sueb; Lee, Ung Soo; Han, Sang Bae; Oh, Ki Wan; Ham, Young Wan; Song, Min Jong; Son, Dong Ju; Hong, Jin Tae

    2015-01-01

    Background Accumulation of beta-amyloid and neuroinflammation trigger Alzheimer?s disease. We previously found that lipopolysaccharide (LPS) caused neuroinflammation with concomitant accumulation of beta-amyloid peptides leading to memory loss. A variety of anti-inflammatory compounds inhibiting nuclear factor kappaB (NF-?B) activation have showed efficacy to hinder neuroinflammation and amyloidogenesis. We also found that bee venom (BV) inhibits NF-?B. Methods A mouse model of LPS-induced me...

  7. Cardiac-Specific Overexpression of Catalase Attenuates Lipopolysaccharide-Induced Myocardial Contractile Dysfunction: Role of Autophagy

    OpenAIRE

    Turdi, Subat; Han, Xuefeng; Huff, Anna F.; Roe, Nathan D.; Hu, Nan; Gao, Feng; Ren, Jun

    2012-01-01

    Lipopolysaccharide (LPS) from Gram-negative bacteria is a major initiator of sepsis, leading to cardiovascular collapse. Accumulating evidence has indicated a role of reactive oxygen species (ROS) in cardiovascular complication in sepsis. This study was designed to examine the effect of cardiac-specific overexpression of catalase in LPS-induced cardiac contractile dysfunction and the underlying mechanism(s) with a focus on autophagy. Catalase transgenic and wild-type FVB mice were challenged ...

  8. Dexmedetomidine reduces lipopolysaccharide induced neuroinflammation, sickness behavior, and anhedonia.

    Directory of Open Access Journals (Sweden)

    Ching-Hua Yeh

    Full Text Available Peripheral innate immune response may induce sickness behavior through activating microglia, excessive cytokines production, and neuroinflammation. Dexmedetomidine (Dex has anti-inflammatory effect. We investigated the effects of Dex on lipopolysaccharide (LPS-induced neuroinflammation and sickness behavior in mice.BALB/c mice were intraperitoneally (i.p. injected with Dex (50 ug/kg or vehicle. One hour later, the mice were injected (i.p. with Escherichia coli LPS (0.33 mg/kg or saline (n = 6 in each group. We analyzed the food and water intake, body weight loss, and sucrose preference of the mice for 24h. We also determined microglia activation and cytokines expression in the brains of the mice. In vitro, we determine cytokines expression in LPS-treated BV-2 microglial cells with or without Dex treatment.In the Dex-pretreated mice, LPS-induced sickness behavior (anorexia, weight loss, and social withdrawal were attenuated and microglial activation was lower than vehicle control. The mRNA expression of TNF-α, MCP-1, indoleamine 2, 3 dioxygenase (IDO, caspase-3, and iNOS were increased in the brain of LPS-challenged mice, which were reduced by Dex but not vehicle.Dexmedetomidine diminished LPS-induced neuroinflammation in the mouse brain and modulated the cytokine-associated changes in sickness behavior.

  9. Synergistic effects of pyrrolizidine alkaloids and lipopolysaccharide on preterm delivery and intrauterine fetal death in mice.

    Science.gov (United States)

    Guo, Yu; Ma, Zhenguo; Kou, Hao; Sun, Rongze; Yang, Hanxiao; Smith, Charles Vincent; Zheng, Jiang; Wang, Hui

    2013-08-29

    Preterm birth is the leading cause of death for newborn infants, and lipopolysaccharide (LPS) is commonly used to induce preterm delivery in experimental animals. Pyrrolizidine alkaloids (PAs) are widespread and occur in foods, herbs, and other plants. This study was to investigate the synergistic effects of LPS and two representative PAs, retrorsine (RTS) and monocrotaline (MCT), on preterm delivery and fetal death. Pregnant Kunming mice were divided into seven groups: control, RTS, MCT, LPS, RTS+LPS and two MCT+LPS groups. Animals in PAs and PAs+LPS groups were dosed intragastrically with RTS (10mg/kg) or MCT (20 mg/kg or 60 mg/kg) from gestational day (GD) 9 to GD16; mice given LPS were injected intraperitoneally with 150 μg/kg on GD15.5. Latencies to delivery, numbers of pups live and dead at birth were recorded, and livers of live neonates were collected. The incidence of LPS-induced preterm birth was enhanced in dams pretreated with MCT, and combination of PAs and LPS increased fetal mortality from PAs. The enhancement of LPS-induced preterm delivery and fetal demise in animals exposed chronically to PAs and other substances found in foods and beverages consumed widely by humans merits further focused investigation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. LPS structure and PhoQ activity are important for Salmonella Typhimurium virulence in the Galleria mellonella infection model [corrected].

    Directory of Open Access Journals (Sweden)

    Jennifer K Bender

    Full Text Available The larvae of the wax moth, Galleria mellonella, have been used experimentally to host a range of bacterial and fungal pathogens. In this study we evaluated the suitability of G. mellonella as an alternative animal model of Salmonella infection. Using a range of inoculum doses we established that the LD₅₀ of SalmonellaTyphimurium strain NCTC 12023 was 3.6 × 10³ bacteria per larva. Further, a set of isogenic mutant strains depleted of known virulence factors was tested to identify determinants essential for S. Typhimurium pathogenesis. Mutants depleted of one or both of the type III secretion systems encoded by Salmonella Pathogenicity Islands 1 and 2 showed no virulence defect. In contrast, we observed reduced pathogenic potential of a phoQ mutant indicating an important role for the PhoPQ two-component signal transduction system. Lipopolysaccharide (LPS structure was also shown to influence Salmonella virulence in G. mellonella. A waaL(rfaL mutant, which lacks the entire O-antigen (OAg, was virtually avirulent, while a wzz(ST/wzz(fepE double mutant expressing only a very short OAg was highly attenuated for virulence. Furthermore, shortly after infection both LPS mutant strains showed decreased replication when compared to the wild type in a flow cytometry-based competitive index assay. In this study we successfully established a G. mellonella model of S. Typhimurium infection. By identifying PhoQ and LPS OAg length as key determinants of virulence in the wax moth larvae we proved that there is an overlap between this and other animal model systems, thus confirming that the G. mellonella infection model is suitable for assessing aspects of Salmonella virulence function.

  11. Genotyping of Campylobacter jejuni strains from Danish broiler chickens by restriction fragment length polymorphism of the LPS gene cluster

    DEFF Research Database (Denmark)

    Knudsen, K.N.; Bang, Dang Duong; Nielsen, E.M.

    2005-01-01

    Aims: To apply and evaluate LG (LPS genes) genotyping, which is a genotyping method based on a cluster of genes involved in the synthesis of surface lipopolysaccharides (LPS) in Campylobacter species, for typing of Campylobacter jejuni isolates obtained from Danish broiler chickens. Furthermore...... and LG genotyping was low when applied to poultry isolates. This is in contrast to previous studies on isolates of human origin that reported a high correlation between results obtained by the two typing methods....

  12. O antigen modulates insect vector acquisition of the bacterial plant pathogen Xylella fastidiosa.

    Science.gov (United States)

    Rapicavoli, Jeannette N; Kinsinger, Nichola; Perring, Thomas M; Backus, Elaine A; Shugart, Holly J; Walker, Sharon; Roper, M Caroline

    2015-12-01

    Hemipteran insect vectors transmit the majority of plant pathogens. Acquisition of pathogenic bacteria by these piercing/sucking insects requires intimate associations between the bacterial cells and insect surfaces. Lipopolysaccharide (LPS) is the predominant macromolecule displayed on the cell surface of Gram-negative bacteria and thus mediates bacterial interactions with the environment and potential hosts. We hypothesized that bacterial cell surface properties mediated by LPS would be important in modulating vector-pathogen interactions required for acquisition of the bacterial plant pathogen Xylella fastidiosa, the causative agent of Pierce's disease of grapevines. Utilizing a mutant that produces truncated O antigen (the terminal portion of the LPS molecule), we present results that link this LPS structural alteration to a significant decrease in the attachment of X. fastidiosa to blue-green sharpshooter foreguts. Scanning electron microscopy confirmed that this defect in initial attachment compromised subsequent biofilm formation within vector foreguts, thus impairing pathogen acquisition. We also establish a relationship between O antigen truncation and significant changes in the physiochemical properties of the cell, which in turn affect the dynamics of X. fastidiosa adhesion to the vector foregut. Lastly, we couple measurements of the physiochemical properties of the cell with hydrodynamic fluid shear rates to produce a Comsol model that predicts primary areas of bacterial colonization within blue-green sharpshooter foreguts, and we present experimental data that support the model. These results demonstrate that, in addition to reported protein adhesin-ligand interactions, O antigen is crucial for vector-pathogen interactions, specifically in the acquisition of this destructive agricultural pathogen. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Instillation of coarse ash particulate matter and lipopolysaccharide produces a systemic inflammatory response in mice

    Energy Technology Data Exchange (ETDEWEB)

    Finnerty, K.; Choi, J.E.; Lau, A.; Davis-Gorman, G.; Diven, C.; Seaver, N.; Linak, W.P.; Witten, M.; McDonagh, P.F. [Arizona Health Science Center, Tucson, AZ (United States)

    2007-07-01

    Coronary ischemic events increase significantly following a 'bad air' day. Ambient particulate matter (PM10) is the pollutant most strongly associated with these events. PM10 produces inflammatory injury to the lower airways. It is not clear, however, whether pulmonary inflammation translates to a systemic response. Lipopolysaccharide (LPS) is a proinflammatory molecule often associated with the coarse fraction of PM. It was hypothesized that PM > 2.5 from coal plus LPS induce pulmonary inflammation leading to a systemic inflammatory response. Mice were intratracheally instilled with saline, PM (200 {mu} g), PM+ LPS10 (PM+ 10 {mu} g LPS), or PM+ LPS100 (PM+ 100 {mu} g LPS). Eighteen hours later, histologic analysis was performed on lungs from each group. Pulmonary and systemic inflammation were assessed by measuring the proinflammatory cytokines tumor necrosis factor (TNF)-{alpha} and interleukin (IL)-6 in the pulmonary supernatant and plasma. In a follow-up study, the effects of LPS alone were assessed. Histologic analysis revealed a dose-dependent elevation in pulmonary inflammation with all treatments. Pulmonary TNF-{alpha} and IL-6 both increased significantly with PM+ LPS100 treatment. Regarding plasma, TNF-{alpha} significantly increased in both PM+ LPS10 and PM+ LPS100 treatments. For plasma IL-6, all groups tended to rise with a significant increase in the PM+ LPS100 group. The results of the follow-up study indicate that the responses to PM+ LPS were not due to LPS alone. These results suggest that coarse coal fly ash PM > 2.5 combined with LPS produced pulmonary and systemic inflammatory responses. The resulting low-level systemic inflammation may contribute to the increased severity of ischemic heart disease observed immediately following a bad air day.

  14. Atherosclerotic plaque disruption induced by stress and lipopolysaccharide in apolipoprotein E knockout mice.

    Science.gov (United States)

    Ni, Mei; Wang, Yan; Zhang, Mei; Zhang, Peng Fei; Ding, Shi Fang; Liu, Chun Xi; Liu, Xiao Ling; Zhao, Yu Xia; Zhang, Yun

    2009-05-01

    To establish an animal model with disruptions of atherosclerotic plaques, 96 male apolipoprotein E knockout (apoE(-/-)) mice were randomly divided into stress, lipopolysaccharide (LPS), stress+LPS, and control groups (n = 24 each). All mice were fed a high-fat diet throughout the experiment, and carotid atherosclerotic lesions were induced by placement of a constrictive perivascular collar. Four weeks after surgery, mice in the LPS and stress+LPS groups were intraperitoneally injected with LPS (1 mg/kg twice per week for 8 wk). Eight weeks after surgery, mice in the stress and stress+LPS groups were treated with intermittent physical stress (electric foot shock and noise stimulation) for 4 wk. Morphological analysis revealed a plaque disruption rate of 16.7% in control, 34.8% in LPS, 54.2% in stress, and 60.9% in stress+LPS groups. The disruption rates in stress and stress+LPS groups were both significantly higher than those of controls (P = 0.007 and P = 0.002, respectively). Luminal thrombosis secondary to plaque disruption was observed only in the stress+LPS group. Both stress and LPS stimulation significantly decreased fibrous cap thickness and increased macrophage and lipid contents in plaques. Moreover, the combination of stress and LPS stimulation further lowered cap thickness and enhanced accumulation of macrophages and expression of inflammatory cytokines and matrix metalloproteinases. Stress activated the sympathetic nervous system, as manifested by increased blood pressure and flow velocity. Plasma fibrinogen levels were remarkably elevated in the stress and stress+LPS groups. In conclusion, stress- and LPS-costimulated apoE(-/-) mice provide a useful model for studies of plaque vulnerability and interventions.

  15. Peptide-assembled graphene oxide as fluorescent turn-on sensor for ultrasensitive Lipopolysaccharide (Endotoxin detection

    Directory of Open Access Journals (Sweden)

    Seng Koon Lim

    2014-06-01

    Full Text Available Introduction: Lipopolysaccharide (LPS, or endotoxin, a major component in the outer cell membrane of Gram-negative bacteria is a very powerful and toxic inflammatory stimulator, resulting in sepsis or septic shock, a significant medical problem affecting about 700 000 patients and causing 250 000 casualties annually in the United States itself. The detection of LPS is highly importance. However, the currently used enzymatic limulus amebocyte lysate assay is highly susceptible to changes in temperature and pH, interference factors, and requires cumbersome sample preparation. A more cost-effective, sensitive and robust detection method is needed. Objective: To design and develop biosensor for LPS detection by assembling a LPS-binding peptide (as LPS receptor with graphene oxide (GO, as fluorescence quencher. Methods: GO was synthesized using a modified Hummer’s method. A synthetic LPS-binding peptide was designed, fluorescent labelled, and assembled with GO in PBS buffer solution. The fluorescence recovery of the peptide-GO was measured upon addition of LPS from Gram negative bacteria: E. coli, K. pneumoniae, Samonella Thyphosa, P. aeruginosa, as well as living pathogenic bacteria. Specificity tests were conducted with various biological molecules to evaluate the sensing performance. Results & Discussion: Specific binding of LPS with peptide release the peptides from GO, resulting in fluorescence recovery, allowing ultrasensitive detection of LPS with the limit of detection of 130 pM, the most sensitive synthetic LPS sensors to-date. The LPS sensor is highly selective to LPS than other biological species. Conclusion: We developed a peptide-GO assembled fluorescence sensor for ultrasensitive and specific LPS/endotoxin detection. This is the most sensitive synthetic LPS sensor reported in the world.

  16. Enteric glial reactivity to systemic LPS administration: Changes in GFAP and S100B protein.

    Science.gov (United States)

    da Cunha Franceschi, Raphaela; Nardin, Patrícia; Machado, Clivia Valle; Tortorelli, Lucas Silva; Martinez-Pereira, Malcon Andrei; Zanotto, Caroline; Gonçalves, Carlos-Alberto; Zancan, Denise Maria

    2017-06-01

    Lipopolysaccharide (LPS) is used to induce inflammation and promotes nervous system activation. Different regions of the brain present heterogeneous glial responses; thus, in order to verify whether systemic LPS-induced inflammation affects the enteric glia differently across the intestinal segments, we evaluated the expressions of two glial activity markers, GFAP and S100B protein, in different intestine segments, at 1h, 24h and 7days after acute systemic LPS administration (0.25 or 2.5mgkg -1 ) in rats. Histological inflammatory analysis indicated that the cecum was most affected when compared to the duodenum and proximal colon at the highest doses of LPS. LPS induced an increased S100B content after 24h in all three regions, which decreased at 7days after the highest dose in all regions. Moreover, at 24h, this dose of LPS increased ex-vivo S100B secretion only in the cecum. The highest dose of LPS also increased GFAP in all regions at 24h, but earlier in the cecum, where LPS-induced enteric S100B and GFAP alterations were dependent on dose, time and intestine region. No associated changes in serum S100B were observed. Our results indicate heterogeneous enteric glial responses to inflammatory insult, as observed in distinct brain areas. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  17. Gram-negative trimeric porins have specific LPS binding sites that are essential for porin biogenesis

    Science.gov (United States)

    Arunmanee, Wanatchaporn; Pathania, Monisha; Solovyova, Alexandra S.; Le Brun, Anton P.; Ridley, Helen; Baslé, Arnaud; van den Berg, Bert; Lakey, Jeremy H.

    2016-01-01

    The outer membrane (OM) of gram-negative bacteria is an unusual asymmetric bilayer with an external monolayer of lipopolysaccharide (LPS) and an inner layer of phospholipids. The LPS layer is rigid and stabilized by divalent cation cross-links between phosphate groups on the core oligosaccharide regions. This means that the OM is robust and highly impermeable to toxins and antibiotics. During their biogenesis, OM proteins (OMPs), which function as transporters and receptors, must integrate into this ordered monolayer while preserving its impermeability. Here we reveal the specific interactions between the trimeric porins of Enterobacteriaceae and LPS. Isolated porins form complexes with variable numbers of LPS molecules, which are stabilized by calcium ions. In earlier studies, two high-affinity sites were predicted to contain groups of positively charged side chains. Mutation of these residues led to the loss of LPS binding and, in one site, also prevented trimerization of the porin, explaining the previously observed effect of LPS mutants on porin folding. The high-resolution X-ray crystal structure of a trimeric porin–LPS complex not only helps to explain the mutagenesis results but also reveals more complex, subtle porin–LPS interactions and a bridging calcium ion. PMID:27493217

  18. LPS infusion suppresses serum FGF21 levels in healthy adult volunteers.

    Science.gov (United States)

    Lauritzen, Esben S; Rittig, Nikolaj; Bach, Ermina; Møller, Niels; Bjerre, Mette

    2017-01-01

    During the inflammatory acute phase response, plasma glucose and serum triglycerides are increased in humans. Fibroblast growth factor (FGF) 21 has plasma glucose and lipid-reducing actions, but its role in the acute inflammatory response in human is unknown. To investigate circulating levels of FGF21 after lipopolysaccharide (LPS) infusion. Two randomized, single-blinded, placebo-controlled crossover trials were used. The studies were performed at a university hospital clinical research center. Study 1 (LPS bolus): Eight young, healthy, lean males were investigated two times: (1) after isotonic saline injection and (2) after LPS injection (bolus of 1 ng/kg). Each study day lasted 4 h. Study 2 (continuous LPS infusion): Eight, healthy males were investigated two times: (1) during continuously isotonic saline infusion and (2) during continuous LPS infusion (0.06 ng/kg/h). Each study day lasted 4 h. Circulating FGF21 levels were quantified every second hour by an immunoassay. A LPS bolus resulted in a late suppression (t = 240 min) of serum FGF21 (P = 0.035). Continuous LPS infusion revealed no significant effects on FGF21 levels (P = 0.82). Our studies show that a bolus of LPS results in decreased FGF21 levels 4 h from exposure. © 2017 The authors.

  19. The antimicrobial peptide cathelicidin enhances activation of lung epithelial cells by LPS.

    Science.gov (United States)

    Shaykhiev, Renat; Sierigk, Johannes; Herr, Christian; Krasteva, Gabriela; Kummer, Wolfgang; Bals, Robert

    2010-12-01

    Epithelial cells (ECs) are usually hyporesponsive to various microbial products. Detection of lipopolysaccharide (LPS), the major component of gram-negative bacteria, is impeded, at least in part, by intracellular sequestration of its receptor, Toll-like receptor-4 (TLR4). In this study, using human bronchial ECs (hBECs) as a model of mucosal epithelium, we tested the hypothesis that the human LPS-binding, membrane-active cationic host defense peptide cathelicidin LL-37 augments epithelial response to LPS by facilitating its delivery to TLR4-containing intracellular compartments. We found that LL-37 significantly increases uptake of LPS by ECs with subsequent targeting to cholera toxin subunit B-labeled structures and lysosomes. This uptake is peptide specific, dose and time dependent, and involves the endocytotic machinery, functional lipid rafts, and epidermal growth factor receptor signaling. Cathelicidin-dependent LPS internalization resulted in significant increased release of the inflammatory cytokines IL-6 and IL-8. This indicates that, in ECs, this peptide may replace LPS-binding protein functions. In polarized ECs, the effect of LL-37 was restricted to the basolateral compartment of the epithelial membrane, suggesting that LL-37-mediated activation of ECs by LPS may be relevant to disease conditions associated with damage to the epithelial barrier. In summary, our study identified a novel role of LL-37 in host-microbe interactions as a host factor that licenses mucosal ECs to respond to LPS.

  20. mRNA expression of genes involved in inflammation and haemostasis in equine fibroblast-like synoviocytes following exposure to lipopolysaccharide, fibrinogen and thrombin

    DEFF Research Database (Denmark)

    Andreassen, Stine Mandrup; Berg, Lise Charlotte; Nielsen, Søren Saxmose

    2015-01-01

    to lipopolysaccharide (LPS), fibrinogen and thrombin. Synovial membranes were collected from metacarpo-phalangeal joints of 6 skeletally mature horses euthanized for non-orthopaedic reasons. Passage 4 fibroblast-like synoviocytes were left non-treated or treated with either 0.1 μ g/ml LPS, 5 mg/ml fibrinogen or 5 U...

  1. Inhibition of Neuroinflammation in LPS-Activated Microglia by Cryptolepine

    Directory of Open Access Journals (Sweden)

    Olumayokun A. Olajide

    2013-01-01

    Full Text Available Cryptolepine, an indoloquinoline alkaloid in Cryptolepis sanguinolenta, has anti-inflammatory property. In this study, we aimed to evaluate the effects of cryptolepine on lipopolysaccharide (LPS- induced neuroinflammation in rat microglia and its potential mechanisms. Microglial activation was induced by stimulation with LPS, and the effects of cryptolepine pretreatment on microglial activation and production of proinflammatory mediators, PGE2/COX-2, microsomal prostaglandin E2 synthase and nitric oxide/iNOS were investigated. We further elucidated the role of Nuclear Factor-kappa B (NF-κB and the mitogen-activated protein kinases in the antiinflammatory actions of cryptolepine in LPS-stimulated microglia. Our results showed that cryptolepine significantly inhibited LPS-induced production of tumour necrosis factor-alpha (TNFα, interleukin-6 (IL-6, interleukin-1beta (IL-1β, nitric oxide, and PGE2. Protein and mRNA levels of COX-2 and iNOS were also attenuated by cryptolepine. Further experiments on intracellular signalling mechanisms show that IκB-independent inhibition of NF-κB nuclear translocation contributes to the anti-neuroinflammatory actions of cryptolepine. Results also show that cryptolepine inhibited LPS-induced p38 and MAPKAPK2 phosphorylation in the microglia. Cell viability experiments revealed that cryptolepine (2.5 and 5 μM did not produce cytotoxicity in microglia. Taken together, our results suggest that cryptolepine inhibits LPS-induced microglial inflammation by partial targeting of NF-κB signalling and attenuation of p38/MAPKAPK2.

  2. Linking mass spectrometry and slab-polyacrylamide gel electrophoresis by passive elution of lipopolysaccharides from reverse-stained gels: analysis of gel-purified lipopolysaccharides from Haemophilus influenzae strain Rd.

    Science.gov (United States)

    Gulin, Sofia; Pupo, Elder; Schweda, Elke K H; Hardy, Eugenio

    2003-09-15

    Haemophilus influenzae is an important cause of human disease, and its lipopolysaccharide (LPS) is known to be a major virulence factor. H. influenzae produces short-chain LPS of which the heterogeneity is often visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using silver staining for detection. Individual bands have not previously been recovered by this method in quantities sufficient for mass spectrometry. In an attempt toward the development of sensitive mass spectrometrical strategies to be used in structural studies of H. influenzae LPS and LPS from other bacteria, we have applied here our previously described slab-PAGE-based micropurification method to obtain unmodified LPS fractions of high purity (>95%) from a crude LPS preparation of H. influenzae strain Rd. Two LPS-fractions were obtained which, after a procedure including mild acid hydrolysis, dephosphorylation, and permethylation of the resulting oligosaccharides, were subjected to tandem electrospray ionization mass spectrometry (ESI-MS/MS). The quantities of micropurified LPS fractions-the recovery of LPS in terms of total mass was 30%-were found sufficient to allow the characterization of LPS glycoforms. The ESI-MS spectra of the individual bands showed reduced heterogeneity. Furthermore, the integrity of the micropurified LPS was confirmed. The spectra-displayed molecular ions showed improved intensity, increased respective signal-to-noise ratios demonstrating the sensitivity of analysis. Consequently, both the direct determination of the molecular masses of the gel-separated LPS glycoforms and sequence analyses using ESI-MS/MS were possible.

  3. Pilose antler peptide attenuates LPS-induced inflammatory reaction.

    Science.gov (United States)

    Dong, Yu; Liu, Li; Shan, Xin; Tang, Juanjuan; Xia, Baomei; Cheng, Xiaolan; Chen, Yanyan; Tao, Weiwei

    2018-03-01

    The present study was designed to study the effects of pilose antler peptide (PAP) on primary culture of nucleus pulposus cells in intervertebral disc. We demonstrated that PAP significantly inhibited lipopolysaccharides (LPS) induced over-production of inflammatory factors including interleukin-1β (IL-1β), tumor necrosis Factor-α (TNF-α) and interleukin-6 (IL-6) in nucleus pulposus cells. PAP also attenuated increase of malondialdehyde (MDA) and decrease of superoxide dismutase (SOD) induced by LPS challenge in a concentration-dependent manner. Moreover, the expression of the protein levels of mitogen-activated protein kinase (MAPK)/nuclear transcription factor-κB(NF-κB) were increased accompanying with the LPS challenge, which were significantly reversed after PAP treatment. Our results demonstrated the ability of PAP to antagonize LPS-mediated inflammation in primary culture of nucleus pulposus in intervertebral disc, suggesting a beneficial potential for its clinical application. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Increased fetal cell trafficking in murine lung following complete pregnancy loss from exposure to lipopolysaccharide.

    Science.gov (United States)

    Johnson, Kirby L; Tao, Kai; Stroh, Helene; Kallenbach, Lisa; Peter, Inga; Richey, Lauren; Rust, Daniel; Bianchi, Diana W

    2010-03-15

    To determine whether chemically induced miscarriage affects fetomaternal trafficking in a mouse model, we measured the amount of fetal DNA present in various maternal organs by polymerase chain reaction amplification following exposure to lipopolysaccharide (LPS). As the frequency of fetal cells and the number of animals with detectable microchimerism following LPS injection were significantly increased, particularly in lung tissue compared to controls, with no signs of an inflammatory response, we conclude that LPS-induced miscarriage results in increased murine fetomaternal cell trafficking, supporting a relationship between fetal loss and the establishment of fetal cell microchimerism. Copyright 2010. Published by Elsevier Inc.

  5. Recurrent exposure to subclinical lipopolysaccharide increases mortality and induces cardiac fibrosis in mice.

    Directory of Open Access Journals (Sweden)

    Wilbur Y W Lew

    Full Text Available BACKGROUND: Circulating subclinical lipopolysaccharide (LPS occurs in health and disease. Ingesting high fatty meals increases LPS that cause metabolic endotoxemia. Subclinical LPS in periodontal disease may impair endothelial function. The heart may be targeted as cardiac cells express TLR4, the LPS receptor. It was hypothesized that recurrent exposure to subclinical LPS increases mortality and causes cardiac fibrosis. METHODS: C57Bl/6 mice were injected with intraperitoneal saline (control, low dose LPS (0.1 or 1 mg/kg, or moderate dose LPS (10 or 20 mg/kg, once a week for 3 months. Left ventricular (LV function (echocardiography, hemodynamics (tail cuff pressure and electrocardiograms (telemetry were measured. Cardiac fibrosis was assessed by picrosirius red staining and LV expression of fibrosis related genes (QRT-PCR. Adult cardiac fibroblasts were isolated and exposed to LPS. RESULTS: LPS injections transiently increased heart rate and blood pressure (<6 hours and mildly decreased LV function with full recovery by 24 hours. Mice tolerated weekly LPS for 2-3 months with no change in activity, appearance, appetite, weight, blood pressure, LV function, oximetry, or blood chemistries. Mortality increased after 60-90 days with moderate, but not low dose LPS. Arrhythmias occurred a few hours before death. LV collagen fraction area increased dose-dependently from 3.0±0.5% (SEM in the saline control group, to 5.6±0.5% with low dose LPS and 9.7±0.9% with moderate dose LPS (P<0.05 moderate vs low dose LPS, and each LPS dose vs control. LPS increased LV expression of collagen Iα1, collagen IIIα1, MMP2, MMP9, TIMP1, periostin and IL-6 (P<0.05 moderate vs low dose LPS and vs control. LPS increased α-SMA immunostaining of myofibroblasts. LPS dose-dependently increased IL-6 in isolated adult cardiac fibroblasts. CONCLUSIONS: Recurrent exposure to subclinical LPS increases mortality and induces cardiac fibrosis.

  6. Exposure to Porphyromonas gingivalis LPS during macrophage polarisation leads to diminished inflammatory cytokine production.

    Science.gov (United States)

    Belfield, Louise A; Bennett, Jon H; Abate, Wondwossen; Jackson, Simon K

    2017-09-01

    The objective of the present study was to determine the effects of concurrent LPS and cytokine priming, reflective of the in vivo milieu, on macrophage production of key periodontitis associated cytokines TNF, IL-1β and IL-6. THP-1 cells were pre-treated with combinations of Porphyromonas gingivalis and Escherichia coli lipopolysaccharide (LPS), concurrently with polarising cytokines IFNγ and IL-4, or PMA as a non-polarised control. Production of key periodontitis associated cytokines in response to subsequent LPS challenge were measured by enzyme - linked immunosorbent assay. Compared with cells incubated with IFNγ or IL-4 alone in the "polarisation" phase, macrophages that were incubated with LPS during the first 24h displayed a down-regulation of TNF and IL-1β production upon secondary LPS treatment in the "activation" phase. In all three macrophage populations (M0, M1 and M2), pre-treatment with P. gingivalis LPS during the polarisation process led to a significant decrease in TNF production in response to subsequent activation by LPS (p=0.007, p=0.002 and p=0.004, respectively). Pre-treatment with E. coli LPS also led to a significant down-regulation in TNF production in all three macrophage populations (pLPS during polarisation also led to the down-regulation of IL-1β in the M1 population (pLPS challenge, whereby production of key periodontitis associated cytokines TNF and IL-1β is reduced after exposure to LPS during the polarisation phase, even in the presence of inflammatory polarising cytokines. This diminished cytokine response may lead to the reduced ability to clear infection and transition to chronic inflammation seen in periodontitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Therapeutic Effect of C-Phycocyanin Extracted from Blue Green Algae in a Rat Model of Acute Lung Injury Induced by Lipopolysaccharide

    OpenAIRE

    Leung, Pak-on; Lee, Hao-Hsien; Kung, Yu-Chien; Tsai, Ming-Fan; Chou, Tz-Chong

    2013-01-01

    C-Phycocyanin (CPC), extracted from blue green algae, is a dietary nutritional supplement due to its several beneficial pharmacological effects. This study was conducted to evaluate whether CPC protects against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in rats. Rats were challenged with LPS (5?mg/kg body weight) intratracheally to induce ALI. After 3?h LPS instillation, rats were administrated with CPC (50?mg/kg body weight, i.p.) for another 3?h. Our results showed that post...

  8. Long term effects of lipopolysaccharide on satellite glial cells in mouse dorsal root ganglia

    Energy Technology Data Exchange (ETDEWEB)

    Blum, E. [Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240 (Israel); Procacci, P.; Conte, V.; Sartori, P. [Dipartimento di Scienze Biomediche per la Salute, University of Milan, via Mangiagalli 14, I-20133 Milano (Italy); Hanani, M., E-mail: hananim@cc.huji.ac.il [Laboratory of Experimental Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem 91240 (Israel)

    2017-01-01

    Lipopolysaccharide (LPS) has been used extensively to study neuroinflammation, but usually its effects were examined acutely (24 h<). We have shown previously that a single intraperitoneal LPS injection activated satellite glial cells (SGCs) in mouse dorsal root ganglia (DRG) and altered several functional parameters in these cells for at least one week. Here we asked whether the LPS effects would persist for 1 month. We injected mice with a single LPS dose and tested pain behavior, assessed SGCs activation in DRG using glial fibrillary acidic protein (GFAP) immunostaining, and injected a fluorescent dye intracellularly to study intercellular coupling. Electron microscopy was used to quantitate changes in gap junctions. We found that at 30 days post-LPS the threshold to mechanical stimulation was lower than in controls. GFAP expression, as well as the magnitude of dye coupling among SGCs were greater than in controls. Electron microscopy analysis supported these results, showing a greater number of gap junctions and an abnormal growth of SGC processes. These changes were significant, but less prominent than at 7 days post-LPS. We conclude that a single LPS injection exerts long-term behavioral and cellular changes. The results are consistent with the idea that SGC activation contributes to hyperalgesia. - Highlights: • A single lipopolysaccharides injection activated glia in mouse dorsal root ganglia for 30 days. • This was accompanied by increased communications by gap junctions among glia and by hyperalgesia. • Glial activation and coupling may contribute to chronic pain.

  9. Inhibition of LPS and Plasmodium falciparum induced cytokine secretion by pentoxifylline and two analogues

    DEFF Research Database (Denmark)

    Jakobsen, P H; Koch, C; Bendtzen, K

    1997-01-01

    Pentoxifylline and the two analogues HWA138 and HWA448, at concentrations exceeding 60 micrograms/ml, inhibited malaria antigen or lipopolysaccharide (LPS) induced TNF-alpha and IL-1 alpha secretion, but not IL-6 secretion, from human peripheral blood mononuclear cells in vitro. HWA448 had lower...... inhibitory activity in vitro than pentoxifylline and HWA138. A small enhancement of cytokine secretion was induced by pentoxifylline and the two analogues at low concentrations. The drugs did not affect cell viability. Pentoxifylline, HWA138 and HWA448 also inhibited LPS induced TNF production in vivo...... in female CF1xBalb/c mice. The drugs were inhibitory at 0.5-1 mg per mouse when mixed with LPS, and 1 mg per mouse of the drugs was inhibitory when injected 1 h before LPS challenge. HWA448 had similar inhibitory activities in vivo compared to pentoxifylline and HWA138, possibly because of the longer serum...

  10. A comparative study of changes of autophagy in rat models of CLP versus LPS induced sepsis.

    Science.gov (United States)

    Zhang, Binglun; Liu, Chunfeng; Yang, Ni; Wang, Xiangdie

    2017-09-01

    In the present study, two different rat models of sepsis, cecal ligation and puncture (CLP), and lipopolysaccharide (LPS), were established. Changes in autophagy in both models were compared using transmission electron microscopy (TEM), immunohistochemistry, western blotting, and quantitative polymerase chain reaction techniques. Consequently, TEM analysis revealed autophagic bodies in the CLP and LPS sepsis models. In addition, autophagy-related protein LC3 A-specific staining was detected in the cytoplasm. However, analysis of protein and gene expression levels revealed a statistically significant increase in autophagic activity 12 and 24 h following induction of the CLP group, and 2 h following induction of the LPS group. Thus, it was concluded that both models of sepsis exhibited increased autophagic activity of the cardiomyocytes over time. The LPS model was superior to the CLP model in perturbation of molecular biological mechanisms, while the latter would be more likely suited for the study of physiological functions.

  11. [Evaluation of usefulness of the enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to lipopolysaccharides of Enterohemorrhagic Escherichia coli (EHEC) strains in patients with gastrointestinal disorders and patients with hemolytic uremic syndrome].

    Science.gov (United States)

    2014-01-01

    Enterohemorrhagic Escherichia coli (EHEC) strains are an important zoonotic food-borne and waterborne pathogens causing diarrhea and the severe hemolytic uremic syndrome (HUS) in humans. The aim of the study was to evaluate the usefulness of enzyme immunoassay ELISA for detection of antibodies to the lipopolysaccharides (LPS) of EHEC in patients with gastrointestinal disorders and patients with hemolytic-uremic syndrome. Sera obtained from 526 patients with gastrointestinal disorders, 26 patients with HUS and 74 patients with different bacterial gastroenteritis infections were screened by an LPS-based ELISA. The LPS antigens of EHEC belonging to serogroups O26, O103, O104, O111, O121, O145, and O157 were obtained by modified Boivin's method. Additionally, to determine the cut-off level, the 122 sera from healthy people were tested. Cellular extract from E. coli O14 were used to remove by absorption antibodies to the Enterobacteriaceae Common Antigen (ECA). Generally, seroprevalence of antibodies to the LPS of different EHEC serogroups in patients with gastrointestinal disorders was low. Additionally, interpretation of the some positive results was difficult to the fact of many serological mutual interactions. Particularly a lot of cross-reactions were seen in the group of sera obtained from patients with different bacterial gastroenteritis infections. The study showed also that in most cases the absorption of antibodies to the ECA had no significant effect on the cross-reactions observed in ELISA. On the other hand, the very high level of antibodies to the LPS antigen of E. coli O26 was found in 5 patients, to E. coli O157 in 4 patients, to E. coli O104 and O145 in 3 patients and E. coli O111 in 2 patients with HUS. Analysis of antibody levels in paired sera taken 2-3 weeks apart obtained from six HUS patients showed a rapid decline of antibody levels to the LPS antigens. The results showed the usefulness of the ELISA with lipopolysaccharides antigens to

  12. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

    Science.gov (United States)

    Caboni, Mariaelena; Pédron, Thierry; Rossi, Omar; Goulding, David; Pickard, Derek; Citiulo, Francesco; MacLennan, Calman A; Dougan, Gordon; Thomson, Nicholas R; Saul, Allan; Sansonetti, Philippe J; Gerke, Christiane

    2015-03-01

    Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg) of the lipopolysaccharide (LPS) plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  13. An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

    Directory of Open Access Journals (Sweden)

    Mariaelena Caboni

    2015-03-01

    Full Text Available Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg of the lipopolysaccharide (LPS plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.

  14. Protective effect of carvacrol on acute lung injury induced by lipopolysaccharide in mice.

    Science.gov (United States)

    Feng, Xiaosheng; Jia, Aiqing

    2014-08-01

    Carvacrol, the major component of Plectranthus amboinicus, has been known to exhibit anti-inflammatory activities. The aim of this study was to investigate the effects of carvacrol on lipopolysaccharide (LPS)-induced endotoxemia and acute lung injury (ALI) in mice. Mice were injected intraperitoneally (i.p.) with LPS and the mortality of mice for 7 days were observed twice a day. Meanwhile, the protective effect of carvacrol (20, 40 or 80 mg/kg) on LPS-induced endotoxemia were detected. Using an experimental model of LPS-induced ALI, we examined the effect of carvacrol in resolving lung injury. The results showed that carvacrol could improve survival during lethal endotoxemia and attenuate LPS-induced ALI in mice. The anti-inflammatory mechanisms of carvacrol may be due to its ability to inhibit NF-κB and MAPKs signaling pathways, thereby inhibiting inflammatory cytokines TNF-α, IL-6 and IL-1β production.

  15. Activation of Epac alleviates inflammation and vascular leakage in LPS-induced acute murine lung injury.

    Science.gov (United States)

    Wang, Xuefeng; Song, Shunde; Hu, Zhengqiang; Zhang, Zhewen; Li, Yajun; Yan, Chunguang; Li, Zigang; Tang, Huifang

    2017-12-01

    Exchange protein directly activated by cAMP (Epac) is an important molecule in cAMP signal transduction, but the effect of Epac on lipopolysaccharide (LPS)-induced acute lung injury (ALI) is unclear. In this study, we treated in vitro and in vivo models with the Epac activator 8CPT to determine the effect and related mechanisms of Epac. The in vitro results indicate that 8CPT inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) release from mouse macrophages (MH-S), whereas the protein kinase A (PKA) activator 6BnZ has no effect. Furthermore, Epac over-expression can significantly suppress TNF-α release from LPS induced MH-S cell, while Epac siRNA can slightly increase TNF-α release. Moreover, 8CPT reduces LPS-induced microvascular permeability in human pulmonary microvascular endothelial cells (HPMVECs), whereas the PKA activator 6BnZ has no effect. In mice with LPS-induced ALI, 8CPT significantly reduces LPS-induced inflammatory cytokine release, neutrophil recruitment, and albumin leakage. LPS simultaneously decreases the Epac but not the PKA levels. However, 8CPT reverses the decreased Epac levels. Furthermore, the mechanism involves the small GTPase Rac1/2 but not the mitogen-activated protein kinase (MAPK) pathway. Thus, Epac activation reduces inflammation and microvascular permeability in LPS-induced lung injury and an Epac activator represents a novel choice for the early therapy of ALI. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Macrophages in the retina of normal Lewis rats and their dynamics after injection of lipopolysaccharide

    NARCIS (Netherlands)

    Yang, P.; de Vos, A. F.; Kijlstra, A.

    1996-01-01

    To investigate the density, distribution, and morphology of macrophages (bone marrow-derived microglia) and major histocompatibility complex (MHC) class II-positive cells in the retina of Lewis rats and the dynamics of these cells after systemic lipopolysaccharide (LPS) injection.

  17. Lipopolysaccharide-binding protein: localization in secretory granules of Paneth cells in the mouse small intestine

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte

    2009-01-01

    Lipopolysaccharide (LPS)-binding protein (LBP) is an acute-phase protein involved in the host's response to endotoxin and mainly synthesized and secreted to the blood by the liver. But in addition, LBP is also made by extrahepatic cells, including the enterocyte-like cell line Caco-2. To study...

  18. Arginine supplementation does not alter nitrogen metabolism of beef steers during a lipopolysaccharide challenge

    Science.gov (United States)

    Demand for arginine (Arg) is reported to increase during immune challenges. This study evaluated effects of lipopolysaccharide (LPS) and abomasal Arg infusion on nitrogen (N) metabolism and immune response of 20 ruminally cannulated steers (369 ± 46 kg BW) in a randomized block design. Each block co...

  19. Active Immunization with Lipopolysaccharide Pseudomonas Antigen for Chronic Pseudomonas Bronchopneumonia in Guinea Pigs

    OpenAIRE

    Pennington, James E.; Hickey, William F.; Blackwood, Linda L.; Arnaut, M. Amin

    1981-01-01

    Chronic respiratory infection with Pseudomonas aeruginosa is a leading clinical problem among patients with cystic fibrosis. Because antimicrobial agents are usually ineffective in eradicating these infections, additional therapeutic or prophylactic measures should be considered. In this study, an experimental guinea pig model of chronic Pseudomonas aeruginosa bronchopneumonia was utilized to determine whether active immunization with lipopolysaccharide (LPS) P. aeruginosa antigen may favorab...

  20. Milk Thistle Extract and Silymarin Inhibit Lipopolysaccharide Induced Lamellar Separation of Hoof Explants in Vitro

    Directory of Open Access Journals (Sweden)

    Nicole Reisinger

    2014-10-01

    Full Text Available The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS in this process remains unclear. Phytogenic substances, like milk thistle (MT and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control, MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application.

  1. Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate

    Science.gov (United States)

    Oyler, Benjamin L.; Khan, Mohd M.; Smith, Donald F.; Harberts, Erin M.; Kilgour, David P. A.; Ernst, Robert K.; Cross, Alan S.; Goodlett, David R.

    2018-02-01

    Recent advances in lipopolysaccharide (LPS) biology have led to its use in drug discovery pipelines, including vaccine and vaccine adjuvant discovery. Desirable characteristics for LPS vaccine candidates include both the ability to produce a specific antibody titer in patients and a minimal host inflammatory response directed by the innate immune system. However, in-depth chemical characterization of most LPS extracts has not been performed; hence, biological activities of these extracts are unpredictable. Additionally, the most widely adopted workflow for LPS structure elucidation includes nonspecific chemical decomposition steps before analyses, making structures inferred and not necessarily biologically relevant. In this work, several different mass spectrometry workflows that have not been previously explored were employed to show proof-of-principle for top down LPS primary structure elucidation, specifically for a rough-type mutant (J5) E. coli-derived LPS component of a vaccine candidate. First, ion mobility filtered precursor ions were subjected to collision induced dissociation (CID) to define differences in native J5 LPS v. chemically detoxified J5 LPS (dLPS). Next, ultra-high mass resolving power, accurate mass spectrometry was employed for unequivocal precursor and product ion empirical formulae generation. Finally, MS3 analyses in an ion trap instrument showed that previous knowledge about dissociation of LPS components can be used to reconstruct and sequence LPS in a top down fashion. A structural rationale is also explained for differential inflammatory dose-response curves, in vitro, when HEK-Blue hTLR4 cells were administered increasing concentrations of native J5 LPS v. dLPS, which will be useful in future drug discovery efforts. [Figure not available: see fulltext.

  2. Long non-coding RNAs and enhancer RNAs regulate the lipopolysaccharide-induced inflammatory response in human monocytes.

    Science.gov (United States)

    IIott, Nicholas E; Heward, James A; Roux, Benoit; Tsitsiou, Eleni; Fenwick, Peter S; Lenzi, Luca; Goodhead, Ian; Hertz-Fowler, Christiane; Heger, Andreas; Hall, Neil; Donnelly, Louise E; Sims, David; Lindsay, Mark A

    2014-06-09

    Early reports indicate that long non-coding RNAs (lncRNAs) are novel regulators of biological responses. However, their role in the human innate immune response, which provides the initial defence against infection, is largely unexplored. To address this issue, here we characterize the long non-coding RNA transcriptome in primary human monocytes using RNA sequencing. We identify 76 enhancer RNAs (eRNAs), 40 canonical lncRNAs, 65 antisense lncRNAs and 35 regions of bidirectional transcription (RBT) that are differentially expressed in response to bacterial lipopolysaccharide (LPS). Crucially, we demonstrate that knockdown of nuclear-localized, NF-κB-regulated, eRNAs (IL1β-eRNA) and RBT (IL1β-RBT46) surrounding the IL1β locus, attenuates LPS-induced messenger RNA transcription and release of the proinflammatory mediators, IL1β and CXCL8. We predict that lncRNAs can be important regulators of the human innate immune response.

  3. Disruption of dTDP-rhamnose biosynthesis modifies lipopolysaccharide core, exopolysaccharide production, and root colonization in Azospirillum brasilense.

    Science.gov (United States)

    Jofré, Edgardo; Lagares, Antonio; Mori, Gladys

    2004-02-16

    The interaction between Azospirillum brasilense and plants is not fully understood, although several bacterial surface components like exopolysaccharides (EPS), flagella, and capsular polysaccharides are required for attachment and colonization. While in other plant-bacteria associations (Rhizobium-legume, Pseudomonas-potato), lipopolysaccharides (LPS) play a key role in the establishment of an effective association, their role in the root colonization by Azospirillum had not been determined. In this study, we isolated a Tn5 mutant of A. brasilense Cd (EJ1) with an apparently modified LPS core structure, non-mucoid colony morphology, increased EPS production, and affected in maize root colonization. A 3790-bp region revealed the presence of three complete open reading frames designated rmlC, rmlB and rmlD. The beginning of a fourth open reading frame was found and designated rmlA. These genes are organized in a cluster which shows homology to the cluster involved in the synthesis of dTDP-rhamnose in other bacteria. Additionally, the analysis of the monosaccharide composition of LPSs showed a diminution of rhamnose compared to the wild-type strain.

  4. Suppression of the lipopolysaccharide-induced expression of MARCKS-related protein (MRP) affects transmigration in activated RAW264.7 cells.

    Science.gov (United States)

    Chun, Kwang-Rok; Bae, Eun Mi; Kim, Jae-Kwan; Suk, Kyoungho; Lee, Won-Ha

    2009-01-01

    The molecular action mechanism of MRP, one of the protein kinase C (PKC) substrates, has been under intense investigation, but reports on its role in macrophage function remain controversial. The treatment of macrophage cell lines with bacterial lipopolysaccharide (LPS) induced a high level of MRP expression suggesting that MRP plays a role in the function of activated macrophages. In order to investigate the role of MRP in activated RAW264.7 cells, we stably transfected MRP-specific shRNA expression constructs and tested for alterations in macrophage-related functions. The down-regulation of MRP expression resulted in a marked reduction in chemotaxis toward MCP-1 or extracellular matrix proteins. Furthermore, pharmacological inhibitors of PKC significantly inhibited the chemotaxis in RAW264.7 cells. These data reveals the pivotal role of MRP in the transmigration of activated RAW264.7 cells.

  5. Genome-wide association study of genetic variants in LPS-stimulated IL-6, IL-8, IL-10, IL-1ra and TNF-α cytokine response in a Danish Cohort

    DEFF Research Database (Denmark)

    Larsen, Margit Hørup; Albrechtsen, Anders; Thørner, Lise Wegner

    2013-01-01

    Cytokine response plays a vital role in various human lipopolysaccharide (LPS) infectious and inflammatory diseases. This study aimed to find genetic variants that might affect the levels of LPS-induced interleukin (IL)-6, IL-8, IL-10, IL-1ra and tumor necrosis factor (TNF)-α cytokine production....

  6. Lipopolysaccharide induced inflammation in the perivascular space in lungs

    Directory of Open Access Journals (Sweden)

    Pabst Reinhard

    2008-07-01

    Full Text Available Abstract Background Lipopolysaccharide (LPS contained in tobacco smoke and a variety of environmental and occupational dusts is a toxic agent causing lung inflammation characterized by migration of neutrophils and monocytes into alveoli. Although migration of inflammatory cells into alveoli of LPS-treated rats is well characterized, the dynamics of their accumulation in the perivascular space (PVS leading to a perivascular inflammation (PVI of pulmonary arteries is not well described. Methods Therefore, we investigated migration of neutrophils and monocytes into PVS in lungs of male Sprague-Dawley rats treated intratracheally with E. coli LPS and euthanized after 1, 6, 12, 24 and 36 hours. Control rats were treated with endotoxin-free saline. H&E stained slides were made and immunohistochemistry was performed using a monocyte marker and the chemokine Monocyte-Chemoattractant-Protein-1 (MCP-1. Computer-assisted microscopy was performed to count infiltrating cells. Results Surprisingly, the periarterial infiltration was not a constant finding in each animal although LPS-induced alveolitis was present. A clear tendency was observed that neutrophils were appearing in the PVS first within 6 hours after LPS application and were decreasing at later time points. In contrast, mononuclear cell infiltration was observed after 24 hours. In addition, MCP-1 expression was present in perivascular capillaries, arteries and the epithelium. Conclusion PVI might be a certain lung reaction pattern in the defense to infectious attacks.

  7. Riboflavin attenuates lipopolysaccharide-induced lung injury in rats.

    Science.gov (United States)

    Al-Harbi, Naif O; Imam, Faisal; Nadeem, Ahmed; Al-Harbi, Mohammed M; Korashy, Hesham M; Sayed-Ahmed, Mohammed M; Hafez, Mohamed M; Al-Shabanah, Othman A; Nagi, Mahmoud N; Bahashwan, Saleh

    2015-01-01

    Riboflavin (vitamin B2) is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) and is therefore required by all flavoproteins. Riboflavin also works as an antioxidant by scavenging free radicals. The present study was designed to evaluate the effects of riboflavin against acute lungs injury induced by the administration of a single intranasal dose (20 μg/rat) of lipopolysaccharides (LPS) in experimental rats. Administration of LPS resulted in marked increase in malondialdehyde (MDA) level (p riboflavin in a dose-dependent manner (30 and 100 mg/kg, respectively). Riboflavin (100 mg/kg, p.o.) showed similar protective effects as dexamethasone (1 mg/kg, p.o.). Administration of LPS showed marked cellular changes including interstitial edema, hemorrhage, infiltration of PMNs, etc., which were reversed by riboflavin administration. Histopathological examinations showed normal morphological structures of lungs tissue in the control group. These biochemical and histopathological examination were appended with iNOS and CAT gene expression. The iNOS mRNA expression was increased significantly (p riboflavin significantly (p riboflavin caused a protective effect against LPS-induced ALI. These results suggest that riboflavin may be used to protect against toxic effect of LPS in lungs.

  8. [Effect of paeonol on LPS-induced rat vascular endothelial cell adhesion reaction].

    Science.gov (United States)

    Chen, Jun-Jun; Dai, Min; Chen, Peng

    2013-03-01

    To observe the effect of Paeonol (Pae) on lipopolysaccharide (LPS) induced rat mononuclear cells (MCs) adhesion to vascular endothelial cells (VECs) and provide basis foundation for inflammatary mechanisms of Pae against atherosclerosis. Rat vascular endothelial cells were isolated with tissue predigested adherent method. LPS was used as stimulator to induce VEC injury. Serum containing Pae obtained from healthy rats which were given Pae in intragastric. RP-HPLC method was used for detecting the concentration of Pae in serum. MTT assay was used to determine the protective effect of Pae on injured VECs. Rose Bengal Staining was used to detect the effect of Pae on LPS-induced MCs adhesion to VECs. LPS induced rat MCs adhesion to VECs. The effect was the strongest when the concentration was 10 ng/mL and incubated with VECs for 5 h. Pae in concentration of 2. 5,5 and 10 microg/mL and incubated for 24 h could effectively inhibit the adhesion and improve the survival rate of LPS injured VECs significantly. LPS can damage VECs. Pae could protect VECs from LPS injury via inhibiting MCs adhesion to VECs and improving the VEC survival rate.

  9. Anti-Inflammatory Effect of Melittin on Porphyromonas Gingivalis LPS-Stimulated Human Keratinocytes.

    Science.gov (United States)

    Kim, Woon-Hae; An, Hyun-Jin; Kim, Jung-Yeon; Gwon, Mi-Gyeong; Gu, Hyemin; Jeon, Minji; Kim, Min-Kyung; Han, Sang-Mi; Park, Kwan-Kyu

    2018-02-05

    Periodontitis is a chronic inflammatory disease that contributes to the destruction of the gingiva. Porphyromonas gingivalis ( P. gingivalis ) can cause periodontitis via its pathogenic lipopolysaccharides (LPS). Melittin, a major component of bee venom, is known to have anti-inflammatory and antibacterial effects. However, the role of melittin in the inflammatory response has not been elucidated in periodontitis-like human keratinocytes. Therefore, we investigated the anti-inflammatory effects of melittin on a P. gingivalis LPS (PgLPS)-treated HaCaT human keratinocyte cell line. The cytotoxicity of melittin was measured using a human keratinocyte cell line, HaCaT, and a Cell Counting Kit-8. The effect of melittin on PgLPS-induced inflammation was determined with Western blot, real-time quantitative PCT, and immunofluorescence. PgLPS increased the expression of toll-like receptor (TLR) 4 and proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and interferon-γ (IFN-γ). Moreover, PgLPS induced activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), extracellular signal-regulated kinase (ERK), and protein kinase B/Akt. Melittin also inhibited the expression of proinflammatory cytokines by suppressing the activation of the NF-κB signaling pathway, ERK, and Akt. Melittin attenuates the PgLPS-induced inflammatory response and could therefore be applied in the treatment of periodontitis for anti-inflammatory effects.

  10. Low endotoxic activity of lipopolysaccharides isolated from Bradyrhizobium, Mesorhizobium, and Azospirillum strains.

    Science.gov (United States)

    Komaniecka, Iwona; Zdzisinska, Barbara; Kandefer-Szerszen, Martyna; Choma, Adam

    2010-12-01

    The endotoxic activities of lipopolysaccharides (LPS) isolated from different strains of rhizobia and rhizobacteria (Bradyrhizobium, Mesorhizobium, and Azospirillum) were compared to those of Salmonella enterica sv. Typhimurium LPS. The biological activity of all the examined preparations, measured as Limulus lysate gelation, production of tumor necrosis factor (TNF), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and nitrogen oxide (NO) induction in human myelomonocytic cells (line THP-1), was considerably lower than that of the reference enterobacterial endotoxin. Among the rhizobial lipopolysaccharides, the activities of Mesorhizobium huakuii and Azospirillum lipoferum LPSs were higher than those of the LPS preparations from five strains of Bradyrhizobium. The weak endotoxic activity of the examined preparations was correlated with differences in lipid A structure compared to Salmonella. © 2010 The Societies and Blackwell Publishing Asia Pty Ltd.

  11. Core Oligosaccharide of Plesiomonas shigelloides PCM 2231 (Serotype O17 Lipopolysaccharide — Structural and Serological Analysis

    Directory of Open Access Journals (Sweden)

    Anna Maciejewska

    2013-02-01

    Full Text Available The herein presented complete structure of the core oligosaccharide of lipopolysaccharide (LPS P. shigelloides Polish Collection of Microorganisms (PCM 2231 (serotype O17 was investigated by 1H, 13C NMR spectroscopy, mass spectrometry, chemical analyses and serological methods. The core oligosaccharide is composed of an undecasaccharide, which represents the second core type identified for P. shigelloides serotype O17 LPS. This structure is similar to that of the core oligosaccharide of P. shigelloides strains 302-73 (serotype O1 and 7-63 (serotype O17 and differs from these only by one sugar residue. Serological screening of 55 strains of P. shigelloides with the use of serum against identified core oligosaccharide conjugated with bovine serum albumin (BSA indicated the presence of similar structures in the LPS core region of 28 O-serotypes. This observation suggests that the core oligosaccharide structure present in strain PCM 2231 could be the most common type among P. shigelloides lipopolysaccharides.

  12. Effects of dexamethasone and cox inhibitors on intracranial pressure and cerebral perfusion in the lipopolysaccharide treated rats with hyperammonemia

    DEFF Research Database (Denmark)

    Rohde, Johan; Pedersen, Hans; Bjerring, Peter N

    2015-01-01

    and lipopolysaccharide (LPS) on the brain can be prevented by dexamethasone and cyclooxygenase (COX) inhibitors. METHOD: Fifty-four male Wistar rats, 6 in each group, were divided into the following groups: Saline+ saline; LPS (2 mg/kg)+saline; LPS+indomethacin (10 mg/kg); LPS+diclofenac (10mg/kg); LPS+dexamethasone (2......mg/kg) in experiment A. Experiment-B included the following groups: LPS+NH3 (140 μmol/kg/min)+saline; LPS+NH3+indomethacin; LPS+NH3+diclofenac and LPS+NH3+dexamethasone. ICP was monitored via a catheter placed in cisterna magna and changes in CBF were recorded by laser Doppler flowmetry. RESULTS: LPS...... with and without NH3 induced a similar increase in plasma 6-keto-prostaglandin-F1α (6-keto-PGF1α) concentration together with a concomitant rise in CBF and ICP. Indomethacin and diclofenac prevented the increase in ICP by LPS alone, and with the addition of NH3 the increase in both CBF and ICP, which...

  13. An RNA-seq screen of P. gingivalis LPS treated human gingival fibroblasts.

    Science.gov (United States)

    Xie, Yufeng; Sun, Mengjun; Xia, Yiru; Shu, Rong

    2018-04-01

    In gingival tissues, lipopolysaccharide (LPS) from Porphyromonas gingivalis (P. gingivalis) is the most critical stimulator for inducing inflammatory response. Human gingival fibroblasts (HGFs) are the major constituents of gingival connective tissues. The aim of this study was to investigate P. gingivalis LPS induced whole transcriptional profile in HGFs and the potential crosstalk between microRNAs (miRNAs) and inflammatory cytokines. RNA-seq was performed on HGFs with and without P. gingivalis LPS treatment. The gene expression of selected inflammatory cytokines and miRNAs induced by LPS at different time points was evaluated by quantitative RT-PCR. The protein expression of chemokines was further confirmed by ELISA. Interestingly, most of the significantly changed genes (198/204) were up-regulated at 4 h after 10 μg/ml LPS stimulation, including inflammatory cytokines and miRNAs. Confirmed by quantitative RT-PCR, the mRNA levels of IL-1β, IL-6 and IL-8 showed single up-regulation peak (4 h/6 h) after 1 μg/ml and 10 μg/ml LPS treatment. Similarly, 1 μg/ml LPS induced single up-regulation peak (8 h) of miRNA-146a, -146b and -155 expression. However, 10 μg/ml LPS induced the increased expression of miRNA-146a and -155 at both early stage (2 h/4 h) and late stage (24 h). Taken together, we investigated P. gingivalis LPS induced whole transcriptional profile, and the different behaviors of miRNA expression induced by different doses of LPS in HGFs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. LPS-induced modules of co-expressed genes in equine peripheral blood mononuclear cells.

    Science.gov (United States)

    Pacholewska, Alicja; Marti, Eliane; Leeb, Tosso; Jagannathan, Vidhya; Gerber, Vincent

    2017-01-05

    Lipopolysaccharide (endotoxin, LPS) is a strong inducer of the innate immune response. It is widespread in our environment, e.g. in house dust and contributes to asthma. Compared to humans, horses are even more sensitive to LPS. However, data on LPS effects on the equine transcriptome are very limited. Using RNA-seq we analysed LPS-induced differences in the gene expression in equine peripheral blood mononuclear cells at the gene and gene-network level in two half-sib families and one group of unrelated horses. 24 h-LPS challenge of equine immune cells resulted in substantial changes in the transcriptomic profile (1,265 differentially expressed genes) showing partial overlap with human data. One of the half-sib families showed a specific response different from the other two groups of horses. We also identified co-expressed gene modules that clearly differentiated 24 h-LPS- from non-stimulated samples. These modules consisted of 934 highly interconnected genes and included genes involved in the immune response (e.g. IL6, CCL22, CXCL6, CXCL2), however, none of the top ten hub genes of the modules have been annotated as responsive to LPS in gene ontology. Using weighted gene co-expression network analysis we identified ten co-expressed gene modules significantly regulated by in vitro stimulation with LPS. Apart from 47 genes (5%) all other genes highly interconnected within the most up- and down-regulated modules were also significantly differentially expressed (FDR LPS-regulated module hub genes have not yet been described as having a role in the immune response to LPS (e.g. VAT1 and TTC25).

  15. Immunogenic peptide mimotopes from an epitope of Escherichia coli O157 LPS.

    Science.gov (United States)

    Navarro, Armando; Hernández-Chiñas, Ulises; Licona-Moreno, Delia; Zenteno, Edgar; Cravioto, Alejandro; Eslava-Campos, Carlos A

    2016-11-01

    Escherichia coli O157:H7 is a subtype of Shiga toxin-producing E. coli that is associated with haemorrhagic colitis and haemolytic uremic syndrome (HUS). Studies of populations in endemic areas have reported that the presence of specific antibodies against the O157 lipopolysaccharide (LPS) is associated with a lower incidence of diarrhoea and HUS. Phage display and IgG anti-O157 LPS antibodies were used in the present study to select peptide mimotopes of O157 LPS expressed in protein III of the M13 phage. Synthetic peptides (SP) were designed using the derived amino acid sequences obtained from DNA nucleotides of 63 selected phagotopes. The LxP/YP/SxL motif was identified in five of the phagotope amino acid sequences. Antibody responses against the phagotopes and their corresponding SPs were evaluated. SP12, one of the designed SP, induced the production of antibodies against the homologous peptide (1:800) and O157 LPS (1:200). The specificity of anti-SP12 antiserum was confirmed by analyzing its response to SP3, an SP with a different amino acid sequence than that of SP12, as well as against an E. coli LPS different from O157. Competitive studies with SP12 and O157 LPS showed a significant decrease in anti-SP12 and anti-LPS O157 antiserum responses against SP12 and O157 LPS, respectively. Eighteen (82%) of the 22 human serum samples with positive reactivity against E coli O157 LPS reacted with SP12 SP (cut-off >0.4). These results support the idea that SP12 is an immunogenic mimotope of O157 LPS. © 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  16. LPS ameliorates renal ischemia/reperfusion injury via Hsp27 up-regulation.

    Science.gov (United States)

    He, Kang; Xia, Lei; Zhang, Jianjun

    2018-03-01

    We have recently reported lipopolysaccharide (LPS) pretreatment attenuated renal ischemia/reperfusion injury (IRI), but the exact mechanism remains to be well elucidated. It was reported that heat shock protein (Hsp) 27 was up-regulated after administration of LPS, but whether a direct link existed between Hsp27 up-regulation and LPS-induced protection against renal IRI is still unknown. Mice were exposed to IRI or sham procedure, with pretreatment of LPS or not. Quercetin, an inhibitor of Hsp27 synthesis, was used, and an RNA interference with adenovirus vector using short hairpin RNA targeting Hsp27 was developed for inhibition of Hsp27 in mice. In addition, mice trans-infected with adenovirus vector encoding Hsp27 were used to testify the role of Hsp27 overexpression in LPS-induced renoprotection. Renal function, histological damage, inflammatory reaction, oxidative stress and apoptosis indices were measured. Western blot analysis was used to detect expression of Hsp27. We found LPS pretreatment stimulated renal up-regulation of Hsp27 and reduced renal IRI proven by less renal dysfunction, histological damage, inflammatory reaction, oxidative stress and apoptosis. It was observed that inhibition of Hsp27 synthesis by Quercetin abolished LPS-induced renoprotective effects. After renal knockdown of Hsp27, LPS-induced tolerance against renal IRI was largely removed. Mice with Hsp27 overexpression showed significantly improved renal function after IRI and LPS combined with Hsp27 overexpression had a synergistic effect on protection against renal IRI. Administration of LPS produces protective effects against renal IRI via Hsp27 up-regulation. Preconditional Hsp27 up-regulation might have a great potential for the treatment of renal IRI via ameliorating apoptosis.

  17. Consequences of alteration in leucine zipper sequence of melittin in its neutralization of lipopolysaccharide-induced proinflammatory response in macrophage cells and interaction with lipopolysaccharide.

    Science.gov (United States)

    Srivastava, Raghvendra M; Srivastava, Saurabh; Singh, Manish; Bajpai, Virendra Kumar; Ghosh, Jimut Kanti

    2012-01-13

    The bee venom antimicrobial peptide, melittin, besides showing versatile activity against microorganisms also neutralizes lipopolysaccharide (LPS)-induced proinflammatory responses in macrophage cells. However, how the amino acid sequence of melittin contributes in its anti-inflammatory properties is mostly unknown. To determine the importance of the leucine zipper sequence of melittin in its neutralization of LPS-induced inflammatory responses in macrophages and interaction with LPS, anti-inflammatory properties of melittin and its three analogues and their interactions with LPS were studied in detail. Two of these analogues, namely melittin Mut-1 (MM-1) and melittin Mut-2 (MM-2), possess leucine to alanine substitutions in the single and double heptadic leucine residue(s) of melittin, respectively, whereas the third analogue is a scrambled peptide (Mel-SCR) that contains the amino acid composition of melittin with minor rearrangement in its leucine zipper sequence. Although MM-1 partly inhibited the production of proinflammatory cytokines in RAW 264.7 and rat primary macrophage cells in the presence of LPS, MM-2 and Mel-SCR were negligibly active. A progressive decrease in interaction of melittin with LPS, aggregation in LPS, and dissociation of LPS aggregates with alteration in the leucine zipper sequence of melittin was observed. Furthermore, with alteration in the leucine zipper sequence of melittin, these analogues failed to exhibit cellular responses associated with neutralization of LPS-induced inflammatory responses in macrophage cells by melittin. The data indicated a probable important role of the leucine zipper sequence of melittin in neutralizing LPS-induced proinflammatory responses in macrophage cells as well as in its interaction with LPS.

  18. Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers

    NARCIS (Netherlands)

    Dillingh, Marlous R.; van Poelgeest, Eveline P.; Malone, Karen E.; Kemper, Elles M.; Stroes, Erik S. G.; Moerland, Matthijs; Burggraaf, Jacobus

    2014-01-01

    Human in vivo models of systemic inflammation are used to study the physiological mechanisms of inflammation and the effect of drugs and nutrition on the immune response. Although in vivo lipopolysaccharide (LPS) challenges have been applied as methodological tool in clinical pharmacology studies,

  19. Metabolically induced liver inflammation leads to NASH and differs from LPS- or IL-1 beta-induced chronic inflammation

    NARCIS (Netherlands)

    Liang, Wen; Lindeman, Jan H.; Menke, Aswin L.; Koonen, Debby P.; Morrison, Martine; Havekes, Louis M.; van den Hoek, Anita M.; Kleemann, Robert

    The nature of the chronic inflammatory component that drives the development of non-alcoholic steatohepatitis (NASH) is unclear and possible inflammatory triggers have not been investigated systematically. We examined the effect of non-metabolic triggers (lipopolysaccharide (LPS), interleukin-1 beta

  20. Metabolically induced liver inflammation leads to NASH and differs from LPS-or IL-1β-induced chronic inflammation

    NARCIS (Netherlands)

    Liang, W.; Lindeman, J.H.; Menke, A.L.; Koonen, D.P.; Morrison, M.; Havekes, L.M.; Hoek, A.M. van den; Kleemann, R.

    2014-01-01

    The nature of the chronic inflammatory component that drives the development of non-alcoholic steatohepatitis (NASH) is unclear and possible inflammatory triggers have not been investigated systematically. We examined the effect of non-metabolic triggers (lipopolysaccharide (LPS), interleukin-1β

  1. LPS-mediated endothelial activation in pulmonary endothelial cells: role of Nox2-dependent IKK-β phosphorylation

    Science.gov (United States)

    Menden, Heather; Tate, Everett; Hogg, Neil

    2013-01-01

    Lipopolysaccharide (LPS)-mediated endothelial activation contributes to lung inflammation and alveolar remodeling seen in premature infants with bronchopulmonary dysplasia (BPD). The mechanisms underlying LPS-mediated oxidative stress and proinflammatory signaling in human pulmonary microvascular endothelial cells (HPMEC) remain unclear. We hypothesized that NADPH oxidase (Nox) mediates LPS-induced endothelial activation in HPMEC by regulating phosphorylation of Toll-like receptor (TLR) pathway proteins. LPS-induced expression of intercellular adhesion molecule 1 (ICAM-1) was associated with increased 2-OH-E+ (marker for superoxide formation) levels and was attenuated by apocynin and the Nox inhibitor, VAS2870. LPS triggered membrane translocation of p67phox, suggesting activation of Nox2. Silencing Nox2, but not Nox4, suppressed LPS-induced ICAM-1 expression in HPMEC. Immunoprecipitation studies showed that inhibitor of κ-B kinase-β (IKK-β) serine phosphorylation induced by LPS was inhibited by Nox2 silencing. We examined whether Nox2-dependent, LPS-mediated IKK-β phosphorylation was regulated by protein phosphatase 2A (PP2A) or TGF-β associated kinase-1 (TAK1) in HPMEC. LPS increased PP2A activity in HPMEC, and inhibition of PP2A did not alter LPS-mediated ICAM-1 expression but attenuated IKK-β phosphorylation. TAK1 inhibition decreased LPS-induced ICAM-1 expression in HPMEC, and Nox2 silencing attenuated LPS-mediated TAK1 phosphorylation (Thr184/187). We demonstrate that Nox2 regulates LPS-mediated endothelial activation in pulmonary endothelial cells by modulating phosphorylation of key kinases in the TLR signaling cascade. Our data support a novel mechanism by which Nox-dependent signaling regulates proinflammatory signaling in pulmonary endothelial cells. Inhibition of vascular Nox may potentially limit lung injury and alveolar remodeling caused by infections in BPD. PMID:23333803

  2. Increase in hypothalamic AMPK phosphorylation induced by prolonged exposure to LPS involves ghrelin and CB1R signaling.

    Science.gov (United States)

    Rivas, Priscila M S; Vechiato, Fernanda M V; Borges, Beatriz C; Rorato, Rodrigo; Antunes-Rodrigues, Jose; Elias, Lucila L K

    2017-07-01

    Acute administration of lipopolysaccharide (LPS) from Gram-negative bacteria induces hypophagia. However, the repeated administration of LPS leads to desensitization of hypophagia, which is associated with increased hypothalamic p-AMPK expression. Because ghrelin and endocannabinoids modulate AMPK activity in the hypothalamus, we hypothesized that these neuromodulators play a role in the reversal of tolerance to hypophagia in rats under long-term exposure to LPS. Male Wistar rats were treated with single (1 LPS, 100μg/kg body weight, ip) or repeated injections of LPS over 6days (6 LPS). Food intake was reduced in the 1 LPS, but not in the 6 LPS group. 6 LPS rats showed an increased serum concentration of acylated ghrelin and reduced ghrelin receptor mRNA expression in the hypothalamus. Ghrelin injection (40μg/kg body weight, ip) increased food intake, body weight gain, p-AMPK hypothalamic expression, neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA expression in control animals (Saline). However, in 6 LPS rats, ghrelin did not alter these parameters. Central administration of a CB1R antagonist (AM251, 200ng/μl in 5μl/rat) induced hypophagia in 6 LPS animals, suggesting that the endocannabinoid system contributes to preserved food intake during LPS tolerance. In the presence of AM251, the ability of ghrelin to phosphorylate AMPK in the hypothalamus of 6 LPS group was restored, but not its orexigenic effect. Our data highlight that the orexigenic effects of ghrelin require CB1R signaling downstream of AMPK activation. Moreover, CB1R-mediated pathways contribute to the absence of hypophagia during repeated exposure to endotoxin. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Nicotinic alpha 7 receptor expression and modulation of the lung epithelial response to lipopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Lorise C Gahring

    Full Text Available Nicotine modulates multiple inflammatory responses in the lung through the nicotinic acetylcholine receptor subtype alpha7 (α7. Previously we reported that α7 modulates both the hematopoietic and epithelium responses in the lung to the bacterial inflammogen, lipopolysaccharide (LPS. Here we apply immunohistochemistry, flow cytometry and RNA-Seq analysis of isolated distal lung epithelium to further define α7-expression and function in this tissue. Mouse lines were used that co-express a bicistronic tau-green fluorescent protein (tGFP as a reporter of α7 (α7G expression and that harbor an α7 with a specific point mutation (α7E260A:G that selectively uncouples it from cell calcium-signaling mechanisms. The tGFP reporter reveals strong cell-specific α7-expression by alveolar macrophages (AM, Club cells and ATII cells. Ciliated cells do not express detectible tGFP, but their numbers decrease by one-third in the α7E260A:G lung compared to controls. Transcriptional comparisons (RNA-Seq between α7G and α7E260A:G enriched lung epithelium 24 hours after challenge with either intra-nasal (i.n. saline or LPS reveals a robust α7-genotype impact on both the stasis and inflammatory response of this tissue. Overall the α7E260A:G lung epithelium exhibits reduced inflammatory cytokine/chemokine expression to i.n. LPS. Transcripts specific to Club cells (e.g., CC10, secretoglobins and Muc5b or to ATII cells (e.g., surfactant proteins were constitutively decreased in in the α7E260A:G lung, but they were strongly induced in response to i.n. LPS. Protein analysis applying immunohistochemistry and ELISA also revealed α7-associated differences suggested by RNA-Seq including altered mucin protein 5b (Muc5b accumulation in the α7E260A:G bronchia, that in some cases appeared to form airway plugs, and a substantial increase in extracellular matrix deposits around α7E260A:G airway bronchia linings that was not seen in controls. Our results show that α7 is

  4. Upregulation of PRMT6 by LPS suppresses Klotho expression through interaction with NF-κB in glomerular mesangial cells.

    Science.gov (United States)

    Tsai, Kuen-Daw; Lee, Wen-Xi; Chen, Wei; Chen, Bo-Yu; Chen, Kuan-Lin; Hsiao, Tzu-Chia; Wang, Sue-Hong; Lee, Yi-Ju; Liang, Shan-Yuan; Shieh, Jia-Ching; Lin, Ting-Hui

    2018-04-01

    Lipopolysaccharide (LPS) released from gram-negative bacteria stimulates immune responses in infected cells. Epigenetic modifications such as DNA methylation and protein methylation modulate LPS-induced innate immune gene expressions. Expression of the Klotho protein decreased with LPS treatment in rats. In a cellular model, information regarding the effect of LPS on Klotho expression was meager. In the present study, we demonstrated that LPS triggered global DNA and protein methylation in glomerular mesangial MES-13 cells. LPS upregulated protein expressions of enzymes central to cellular methylation reactions, especially protein arginine methyltransferase 6 (PRMT6) in MES-13 cells. Expression of the Klotho protein was diminished by LPS and was restored by 5-Aza-2'-deoxycytidine (5-Aza-2'-dc), AMI-1, and ammonium pyrrolidinedithiocarbamate (PDTC), but not adenosine aldehyde (AdOx). NF-κB was identified as a substrate for arginine methylation and interacted with PRMT6 in MES-13 cells. Inhibition of PRMT activity by AMI-1 blocked LPS-induced NF-κB nuclear translocation in MES-13 cells. Our data indicate that NF-κB negatively regulated Klotho expression with an interaction with PRMT6, which was upregulated by LPS in MES-13 cells. © 2017 Wiley Periodicals, Inc.

  5. Chlorogenic Acid Combined with Lactobacillus plantarum 2142 Reduced LPS-Induced Intestinal Inflammation and Oxidative Stress in IPEC-J2 Cells.

    Science.gov (United States)

    Palócz, Orsolya; Pászti-Gere, Erzsébet; Gálfi, Péter; Farkas, Orsolya

    2016-01-01

    This study was carried out to investigate protective effect of chlorogenic acid against lipopolysaccharide-induced inflammation and oxidative stress in intestinal epithelial cells. As a marker of inflammatory response, IL-6, IL-8, TNF-α mRNA and protein levels, furthermore, COX-2 mRNA level were followed up. Intracellular redox status and extracellular H2O2 level were also monitored by two fluorescent assays (DCFH-DA, Amplex Red). Moreover, the effect of gut microbiota metabolites in the above mentioned processes was taken into account in our model using Lactobacillus plantarum 2142 bacterial strain. Our data revealed that chlorogenic acid had significant lowering effect on the inflammatory response. Treatment with chlorogenic acid (25-50 μM) significantly decreased gene expression and concentration of proinflammatory cytokines IL-6 and IL-8 compared to LPS-treated cells. COX-2 and TNF-α mRNA levels were also reduced. Furthermore, chlorogenic acid reduced the level of reactive oxygen species in IPEC-J2 cells. Simultaneous application of chlorogenic acid and Lactobacillus plantarum 2142 supernatant resulted protective effect against LPS-induced inflammation and oxidative stress as well.

  6. IgG Responses to Porins and Lipopolysaccharide within an Outer Membrane-Based Vaccine against Nontyphoidal Salmonella Develop at Discordant Rates.

    Science.gov (United States)

    Schager, Anna E; Dominguez-Medina, C Coral; Necchi, Francesca; Micoli, Francesca; Goh, Yun Shan; Goodall, Margaret; Flores-Langarica, Adriana; Bobat, Saeeda; Cook, Charlotte N L; Arcuri, Melissa; Marini, Arianna; King, Lloyd D W; Morris, Faye C; Anderson, Graham; Toellner, Kai-Michael; Henderson, Ian R; López-Macías, Constantino; MacLennan, Calman A; Cunningham, Adam F

    2018-03-06

    Antibodies acquired after vaccination or natural infection with Gram-negative bacteria, such as invasive Salmonella enterica serovar Typhimurium, can protect against disease. Immunization with naturally shed outer membrane vesicles from Gram-negative bacteria is being studied for its potential to protect against many infections, since antigens within vesicles maintain their natural conformation and orientation. Shedding can be enhanced through genetic modification, and the resulting particles, generalized modules for membrane antigens (GMMA), not only offer potential as vaccines but also can facilitate the study of B-cell responses to bacterial antigens. Here we show that the response to immunization with GMMA from S  Typhimurium (STmGMMA) provides B-cell-dependent protection and induces antibodies to two immunodominant antigens, lipopolysaccharide (LPS) and porins. Antibodies to LPS O antigen (O-Ag) markedly enhance protection in the spleen, but this effect is less marked in the liver. Strikingly, IgG responses to LPS and porins develop with distinct kinetics. In the first week after immunization, there is a dramatic T-cell-independent B1b-cell-associated induction of all IgG isotypes, except IgG1, to porins but not to LPS. In contrast, production of IgG1 to either antigen was delayed and T cell dependent. Nevertheless, after 1 month, cells in the bone marrow secreting IgG against porins or LPS were present at a similar frequency. Unexpectedly, immunization with O-Ag-deficient STmGMMA did not substantially enhance the anti-porin response. Therefore, IgG switching to all antigens does not develop synchronously within the same complex and so the rate of IgG switching to a single component does not necessarily reflect its frequency within the antigenic complex. IMPORTANCE Vaccines save millions of lives, yet for some infections there are none. This includes some types of Salmonella infections, killing hundreds of thousands of people annually. We show how a new type

  7. Characterization of Two Novel Lipopolysaccharide Phosphoethanolamine Transferases in Pasteurella multocida and Their Role in Resistance to Cathelicidin-2.

    Science.gov (United States)

    Harper, Marina; Wright, Amy; St Michael, Frank; Li, Jianjun; Deveson Lucas, Deanna; Ford, Mark; Adler, Ben; Cox, Andrew D; Boyce, John D

    2017-11-01

    The lipopolysaccharide (LPS) produced by the Gram-negative bacterial pathogen Pasteurella multocida has phosphoethanolamine (PEtn) residues attached to lipid A, 3-deoxy-d-manno-octulosonic acid (Kdo), heptose, and galactose. In this report, we show that PEtn is transferred to lipid A by the P. multocida EptA homologue, PetL, and is transferred to galactose by a novel PEtn transferase that is unique to P. multocida called PetG. Transcriptomic analyses indicated that petL expression was positively regulated by the global regulator Fis and negatively regulated by an Hfq-dependent small RNA. Importantly, we have identified a novel PEtn transferase called PetK that is responsible for PEtn addition to the single Kdo molecule (Kdo 1 ), directly linked to lipid A in the P. multocida glycoform A LPS. In vitro assays showed that the presence of a functional petL and petK , and therefore the presence of PEtn on lipid A and Kdo 1 , was essential for resistance to the cationic, antimicrobial peptide cathelicidin-2. The importance of PEtn on Kdo 1 and the identification of the transferase responsible for this addition have not previously been shown. Phylogenetic analysis revealed that PetK is the first representative of a new family of predicted PEtn transferases. The PetK family consists of uncharacterized proteins from a range of Gram-negative bacteria that produce LPS glycoforms with only one Kdo molecule, including pathogenic species within the genera Vibrio , Bordetella , and Haemophilus We predict that many of these bacteria will require the addition of PEtn to Kdo for maximum protection against host antimicrobial peptides. Copyright © 2017 American Society for Microbiology.

  8. Development of a bead-based Luminex assay using lipopolysaccharide specific monoclonal antibodies to detect biological threats from Brucella species.

    Science.gov (United States)

    Silbereisen, Angelika; Tamborrini, Marco; Wittwer, Matthias; Schürch, Nadia; Pluschke, Gerd

    2015-10-05

    Brucella, a Gram-negative bacterium, is classified as a potential bioterrorism agent mainly due to the low dose needed to cause infection and the ability to transmit the bacteria via aerosols. Goats/sheep, cattle, pigs, dogs, sheep and rodents are infected by B. melitensis, B. abortus, B. suis, B. canis, B. ovis and B. neotomae, respectively, the six classical Brucella species. Most human cases are caused by B. melitensis and B. abortus. Our aim was to specifically detect Brucellae with 'smooth' lipopolysaccharide (LPS) using a highly sensitive monoclonal antibody (mAb) based immunological assay. To complement molecular detection systems for potential bioterror agents, as required by international biodefense regulations, sets of mAbs were generated by B cell hybridoma technology and used to develop immunological assays. The combination of mAbs most suitable for an antigen capture assay format was identified and an immunoassay using the Luminex xMAP technology was developed. MAbs specific for the LPS O-antigen of Brucella spp. were generated by immunising mice with inactivated B. melitensis or B. abortus cells. Most mAbs recognised both B. melitensis and B. abortus and antigen binding was not impeded by inactivation of the bacterial cells by γ irradiation, formalin or heat treatment, a step required to analyse the samples immunologically under biosafety level two conditions. The Luminex assay recognised all tested Brucella species with 'smooth' LPS with detection limits of 2×10(2) to 8×10(4) cells per mL, depending on the species tested. Milk samples spiked with Brucella spp. cells were identified successfully using the Luminex assay. In addition, the bead-based immunoassay was integrated into a multiplex format, allowing for simultaneous, rapid and specific detection of Brucella spp., Bacillus anthracis, Francisella tularensis and Yersinia pestis within a single sample. Overall, the robust Luminex assay should allow detection of Brucella spp. in both natural

  9. Effects of tylosin on serum cytokine levels in healthy and lipopolysaccharide-treated mice.

    Science.gov (United States)

    Er, Ayse; Yazar, Enver; Uney, Kamil; Elmas, Muammer; Altan, Feray; Cetin, Gul

    2010-03-01

    The effects of different doses of tylosin on serum cytokine concentrations were investigated in healthy and lipopolysaccharide-treated mice. The mice were divided into seven groups. Lipopolysaccharide (LPS) was injected into the positive control group. The other six groups received three different tylosin doses concurrently without or with LPS: 10 mg/kg, 100 mg/kg, 500 mg/kg, 10 mg/kg + LPS, 100 mg/kg + LPS and 500 mg/kg + LPS. After treatment, serum samples were collected at 0, 1, 2, 3, 6, 12 and 24 hours. Serum tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta) and IL10 levels were determined by enzyme-linked immunosorbent assay (ELISA). Tylosin doses of 10 and 100 mg/kg induced no cytokine production in the healthy mice. Tylosin at 500 mg/kg had no effect on TNFalpha or IL1beta production, but it induced IL10 production in healthy mice. All doses of tylosin reduced the elevated TNFalpha and IL1beta in LPS-treated mice but increased their IL10 levels. In conclusion, these data suggest that tylosin has an immunomodulatory effect at the dose recommended for use against infection.

  10. Pre- and neonatal exposure to lipopolysaccharide or the enteric metabolite, propionic acid, alters development and behavior in adolescent rats in a sexually dimorphic manner.

    Directory of Open Access Journals (Sweden)

    Kelly A Foley

    Full Text Available Alterations in the composition of the gut microbiome and/or immune system function may have a role in the development of autism spectrum disorders (ASD. The current study examined the effects of prenatal and early life administration of lipopolysaccharide (LPS, a bacterial mimetic, and the short chain fatty acid, propionic acid (PPA, a metabolic fermentation product of enteric bacteria, on developmental milestones, locomotor activity, and anxiety-like behavior in adolescent male and female offspring. Pregnant Long-Evans rats were subcutaneously injected once a day with PPA (500 mg/kg on gestation days G12-16, LPS (50 µg/kg on G15-16, or vehicle control on G12-16 or G15-16. Male and female offspring were injected with PPA (500 mg/kg or vehicle twice a day, every second day from postnatal days (P 10-18. Physical milestones and reflexes were monitored in early life with prenatal PPA and LPS inducing delays in eye opening. Locomotor activity and anxiety were assessed in adolescence (P40-42 in the elevated plus maze (EPM and open-field. Prenatal and postnatal treatments altered behavior in a sex-specific manner. Prenatal PPA decreased time spent in the centre of the open-field in males and females while prenatal and postnatal PPA increased anxiety behavior on the EPM in female rats. Prenatal LPS did not significantly influence those behaviors. Evidence for the double hit hypothesis was seen as females receiving a double hit of PPA (prenatal and postnatal displayed increased repetitive behavior in the open-field. These results provide evidence for the hypothesis that by-products of enteric bacteria metabolism such as PPA may contribute to ASD, altering development and behavior in adolescent rats similar to that observed in ASD and other neurodevelopmental disorders.

  11. Outer membrane protein X (Ail) contributes to Yersinia pestis virulence in pneumonic plague and its activity is dependent on the lipopolysaccharide core length.

    Science.gov (United States)

    Kolodziejek, Anna M; Schnider, Darren R; Rohde, Harold N; Wojtowicz, Andrzej J; Bohach, Gregory A; Minnich, Scott A; Hovde, Carolyn J

    2010-12-01

    Yersinia pestis, the causative agent of plague, is one of the most virulent microorganisms known. The outer membrane protein X (OmpX) in Y. pestis KIM is required for efficient bacterial adherence to and internalization by cultured HEp-2 cells and confers resistance to human serum. Here, we tested the contribution of OmpX to disease progression in the fully virulent Y. pestis CO92 strain by engineering a deletion mutant and comparing its ability in mediating pneumonic plague to that of the wild type in two animal models. The deletion of OmpX delayed the time to death up to 48 h in a mouse model and completely attenuated virulence in a rat model of disease. All rats challenged with 1 × 10(8) CFU of the ompX mutant survived, compared to the 50% lethal dose (LD50) of 1.2 × 10(3) CFU for the wild-type strain. Because murine serum is not bactericidal for the ompX mutant, the mechanism underlying the delay in time to death in mice was attributed to loss of adhesion/internalization properties but not serum resistance. The rat model, which is most similar to humans, highlighted the critical role of serum resistance in disease. To resolve conflicting evidence for the role of Y. pestis lipopolysaccharide (LPS) and OmpX in serum resistance, ompX was cloned into Escherichia coli D21 and three isogenic derivatives engineered to have progressively truncated LPS core saccharides. OmpX-mediated serum resistance, adhesiveness, and invasiveness, although dependent on LPS core length, displayed these functions in E. coli, independently of other Yersinia proteins and/or LPS. Also, autoaggregation was required for efficient OmpX-mediated adhesiveness and internalization but not serum resistance.

  12. Pre- and neonatal exposure to lipopolysaccharide or the enteric metabolite, propionic acid, alters development and behavior in adolescent rats in a sexually dimorphic manner.

    Science.gov (United States)

    Foley, Kelly A; Ossenkopp, Klaus-Peter; Kavaliers, Martin; Macfabe, Derrick F

    2014-01-01

    Alterations in the composition of the gut microbiome and/or immune system function may have a role in the development of autism spectrum disorders (ASD). The current study examined the effects of prenatal and early life administration of lipopolysaccharide (LPS), a bacterial mimetic, and the short chain fatty acid, propionic acid (PPA), a metabolic fermentation product of enteric bacteria, on developmental milestones, locomotor activity, and anxiety-like behavior in adolescent male and female offspring. Pregnant Long-Evans rats were subcutaneously injected once a day with PPA (500 mg/kg) on gestation days G12-16, LPS (50 µg/kg) on G15-16, or vehicle control on G12-16 or G15-16. Male and female offspring were injected with PPA (500 mg/kg) or vehicle twice a day, every second day from postnatal days (P) 10-18. Physical milestones and reflexes were monitored in early life with prenatal PPA and LPS inducing delays in eye opening. Locomotor activity and anxiety were assessed in adolescence (P40-42) in the elevated plus maze (EPM) and open-field. Prenatal and postnatal treatments altered behavior in a sex-specific manner. Prenatal PPA decreased time spent in the centre of the open-field in males and females while prenatal and postnatal PPA increased anxiety behavior on the EPM in female rats. Prenatal LPS did not significantly influence those behaviors. Evidence for the double hit hypothesis was seen as females receiving a double hit of PPA (prenatal and postnatal) displayed increased repetitive behavior in the open-field. These results provide evidence for the hypothesis that by-products of enteric bacteria metabolism such as PPA may contribute to ASD, altering development and behavior in adolescent rats similar to that observed in ASD and other neurodevelopmental disorders.

  13. Photodynamic therapy for inactivating endodontic bacterial biofilms and effect of tissue inhibitors on antibacterial efficacy

    Science.gov (United States)

    Shrestha, Annie; Kishen, Anil

    Complex nature of bacterial cell membrane and structure of biofilm has challenged the efficacy of antimicrobial photodynamic therapy (APDT) to achieve effective disinfection of infected root canals. In addition, tissue-inhibitors present inside the root canals are known to affect APDT activity. This study was aimed to assess the effect of APDT on bacterial biofilms and evaluate the effect of tissue-inhibitors on the APDT. Rose-bengal (RB) and methylene-blue (MB) were tested on Enterococcus faecalis (gram-positive) and Pseudomonas aeruginosa (gram-negative) biofilms. In vitro 7- day old biofilms were sensitized with RB and MB, and photodynamically activated with 20-60 J/cm2. Photosensitizers were pre-treated with different tissue-inhibitors (dentin, dentin-matrix, pulp tissue, bacterial lipopolysaccharides (LPS), and bovine serum albumin (BSA)) and tested for antibacterial effect of APDT. Microbiological culture based analysis was used to analyze the cell viability, while Laser Scanning Confocal Microscopy (LSCM) was used to examine the structure of biofilm. Photoactivation resulted in significant reduction of bacterial biofilms with RB and MB. The structure of biofilm under LSCM was found to be disrupted with reduced biofilm thickness. Complete biofilm elimination could not be achieved with both tested photosensitizers. APDT effect using MB and RB was inhibited in a decreasing order by dentin-matrix, BSA, pulp, dentin and LPS (Pendodontic environment.

  14. Compound list: LPS [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available LPS LPS 00A07 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/LPS....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/LPS.Rat.in..._vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/LPS.Rat.in_vivo.Liver.Single.zip ...

  15. Contribution of bacterial pathogens to evoking serological disease markers and aggravating disease activity in rheumatoid arthritis

    Science.gov (United States)

    Waritani, Takaki; Fukai, Richio; Shionoya, Hiroshi; Itoh, Hiroshi

    2018-01-01

    Commensal bacteria and their pathogenic components in the gastrointestinal tract and oral cavity may play pathological roles in autoimmune diseases. To study the possible involvement of bacterial pathogens in autoimmune diseases, IgG and IgA antibodies against pathogenic components produced by three strains of commensal bacteria, Escherichia coli-lipopolysaccharide (E. coli-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and peptidoglycan polysaccharide (PG-PS) from Streptococcus pyogenes, were determined by an improved ELISA system for sera from two groups of patients with rheumatoid arthritis (RA), who met rapid radiographic progression (RRP) criteria and non-RRP, and compared to normal (NL) controls. Antibody responses to these bacterial pathogens are unique and consistent in individuals, and no fundamental difference was observed between RA and NL controls. Despite the similar antibody responses to pathogens, lower IgG or higher IgA and consequent higher IgA/IgG antibody ratio among the patients with RA related to disease marker levels and disease activity. Peculiarly, the IgA/IgG anti-Pg-LPS antibody ratio resulted from lower IgG and higher IgA antibody responses to Pg-LPS strongly correlated not only with rheumatoid factor (RF), but also correlated with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and disease activity score of 28 joints with ESR (DAS28-ESR) in the RRP group. In contrast, the IgA/IgG anti-E. coli-LPS and anti-PG-PS antibody ratio correlated or tended to correlate with RF, ESR, CRP, and DAS28-ESR in the non-RRP group, whereas either the IgG or IgA anti-Pg-LPS antibody levels and consequent IgA/IgG anti-Pg-LPS antibody ratio did not correlate with any clinical marker levels in this group. Notably, anti-circular-citrullinated peptide (CCP) antibody levels, which did not correlate with either IgG or IgA antibody levels to any pathogens, did not correlate with severity of arthritis in both RRP and non-RRP. Taken together, we propose

  16. Contribution of bacterial pathogens to evoking serological disease markers and aggravating disease activity in rheumatoid arthritis.

    Science.gov (United States)

    Terato, Kuniaki; Waritani, Takaki; Fukai, Richio; Shionoya, Hiroshi; Itoh, Hiroshi; Katayama, Kou

    2018-01-01

    Commensal bacteria and their pathogenic components in the gastrointestinal tract and oral cavity may play pathological roles in autoimmune diseases. To study the possible involvement of bacterial pathogens in autoimmune diseases, IgG and IgA antibodies against pathogenic components produced by three strains of commensal bacteria, Escherichia coli-lipopolysaccharide (E. coli-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and peptidoglycan polysaccharide (PG-PS) from Streptococcus pyogenes, were determined by an improved ELISA system for sera from two groups of patients with rheumatoid arthritis (RA), who met rapid radiographic progression (RRP) criteria and non-RRP, and compared to normal (NL) controls. Antibody responses to these bacterial pathogens are unique and consistent in individuals, and no fundamental difference was observed between RA and NL controls. Despite the similar antibody responses to pathogens, lower IgG or higher IgA and consequent higher IgA/IgG antibody ratio among the patients with RA related to disease marker levels and disease activity. Peculiarly, the IgA/IgG anti-Pg-LPS antibody ratio resulted from lower IgG and higher IgA antibody responses to Pg-LPS strongly correlated not only with rheumatoid factor (RF), but also correlated with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and disease activity score of 28 joints with ESR (DAS28-ESR) in the RRP group. In contrast, the IgA/IgG anti-E. coli-LPS and anti-PG-PS antibody ratio correlated or tended to correlate with RF, ESR, CRP, and DAS28-ESR in the non-RRP group, whereas either the IgG or IgA anti-Pg-LPS antibody levels and consequent IgA/IgG anti-Pg-LPS antibody ratio did not correlate with any clinical marker levels in this group. Notably, anti-circular-citrullinated peptide (CCP) antibody levels, which did not correlate with either IgG or IgA antibody levels to any pathogens, did not correlate with severity of arthritis in both RRP and non-RRP. Taken together, we propose

  17. Biochemical principle of Limulus test for detecting bacterial endotoxins.

    Science.gov (United States)

    Iwanaga, Sadaaki

    2007-05-01

    A hemocyte lysate from horseshoe crab (Limulus) produced a gel, when exposed to Gram-negative bacterial endotoxins, lipopolysaccharides (LPS). This gelation reaction of the lysate, so-called Limulus test, has been widely employed as a simple and very sensitive assay method for endotoxins. Recent biochemical studies on the principle of Limulus test indicate that the hemocytes contain several serine protease zymogens, which constitute a coagulation cascade triggered by endotoxins, and that there is a (1,3)-β-D-glucan-mediated coagulation pathway which also results in the formation of gel. Up to now, six protein components, designated coagulogen, proclotting enzyme, factor B, factor C, and factor G, all of which are closely associated with the endotoxin-mediated coagulation pathway, have been purified and biochemically characterized. The molecular structures of these proteins have also been elucidated. Moreover, the reconstitution experiments using the isolated clotting factors, factor C, factor B, proclotting enzyme and coagulogen in the presence of endotoxin, leads to the formation of coagulin gel. Here, I will focus on the biochemical principle of Limulus test for detecting bacterial endotoxins, and its activation and regulation mechanism on the LPS-mediated coagulation cascade.

  18. A Fermented Whole Grain Prevents Lipopolysaccharides-Induced Dysfunction in Human Endothelial Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Laura Giusti

    2017-01-01

    Full Text Available Endogenous and exogenous signals derived by the gut microbiota such as lipopolysaccharides (LPS orchestrate inflammatory responses contributing to development of the endothelial dysfunction associated with atherosclerosis in obesity, metabolic syndrome, and diabetes. Endothelial progenitor cells (EPCs, bone marrow derived stem cells, promote recovery of damaged endothelium playing a pivotal role in cardiovascular repair. Since healthy nutrition improves EPCs functions, we evaluated the effect of a fermented grain, Lisosan G (LG, on early EPCs exposed to LPS. The potential protective effect of LG against LPS-induced alterations was evaluated as cell viability, adhesiveness, ROS production, gene expression, and NF-kB signaling pathway activation. Our results showed that LPS treatment did not affect EPCs viability and adhesiveness but induced endothelial alterations via activation of NF-kB signaling. LG protects EPCs from inflammation as well as from LPS-induced oxidative and endoplasmic reticulum (ER stress reducing ROS levels, downregulating proinflammatory and proapoptotic factors, and strengthening antioxidant defense. Moreover, LG pretreatment prevented NF-kB translocation from the cytoplasm into the nucleus caused by LPS exposure. In human EPCs, LPS increases ROS and upregulates proinflammatory tone, proapoptotic factors, and antioxidants. LG protects EPCs exposed to LPS reducing ROS, downregulating proinflammatory and proapoptotic factors, and strengthening antioxidant defenses possibly by inhibiting NF-κB nuclear translocation.

  19. Protective effects of melatonin on lipopolysaccharide-induced mastitis in mice.

    Science.gov (United States)

    Shao, Guoxi; Tian, Yinggang; Wang, Haiyu; Liu, Fangning; Xie, Guanghong

    2015-12-01

    Melatonin, a secretory product of the pineal gland, has been reported to have antioxidant and anti-inflammatory effects. However, the protective effects of melatonin on lipopolysaccharide (LPS)-induced mastitis have not been reported. The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of melatonin on LPS-induced mastitis both in vivo and in vitro. In vivo, our results showed that melatonin attenuated LPS-induced mammary histopathologic changes and myeloperoxidase (MPO) activity. Melatonin also inhibited LPS-induced inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) production in mammary tissues. In vitro, melatonin was found to inhibit LPS-induced TNF-α and IL-6 production in mouse mammary epithelial cells. Melatonin also suppressed LPS-induced Toll-like receptor 4 (TLR4) expression and nuclear factor-kappaB (NF-κB) activation in a dose-dependent manner. In addition, melatonin was found to up-regulate the expression of PPAR-γ. Inhibition of PPAR-γ by GW9662 reduced the anti-inflammatory effects of melatonin. In conclusion, we found that melatonin, for the first time, had protective effects on LPS-induced mastitis in mice. The anti-inflammatory mechanism of melatonin was through activating PPAR-γ which subsequently inhibited LPS-induced inflammatory responses. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Novel insights in preventing Gram-negative bacterial infection in cirrhotic patients: review on the effects of GM-CSF in maintaining homeostasis of the immune system.

    Science.gov (United States)

    Xu, Dong; Zhao, Manzhi; Song, Yuhu; Song, Jianxin; Huang, Yuancheng; Wang, Junshuai

    2015-01-01

    Cirrhotic patients with dysfunctional and/or low numbers of leukocytes are often infected with bacteria, especially Gram-negative bacteria, which is characterized by producing lipopolysaccharide (LPS). Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine that influences the production, maturation, function, and survival of various immune cells. In this paper, we reviewed not only Toll-like receptors 4 (TLR4) signaling pathway and its immunological effect, but also the specific stimulating function and autocrine performance of GM-CSF on hematopoietic cells, as well as the recent discovery of innate response activator-B cells in protection against microbial sepsis and the direct LPS-TLR4 signaling on hematopoiesis. Thus we concluded that GM-CSF might play important roles in preventing Gram-negative bacterial infections in cirrhotic patients through maintaining immune system functions and homeostasis.

  1. Accumulation mode particles and LPS exposure induce TLR-4 dependent and independent inflammatory responses in the lung.

    Science.gov (United States)

    Fonceca, Angela M; Zosky, Graeme R; Bozanich, Elizabeth M; Sutanto, Erika N; Kicic, Anthony; McNamara, Paul S; Knight, Darryl A; Sly, Peter D; Turner, Debra J; Stick, Stephen M

    2018-01-22

    Accumulation mode particles (AMP) are formed from engine combustion and make up the inhalable vapour cloud of ambient particulate matter pollution. Their small size facilitates dispersal and subsequent exposure far from their original source, as well as the ability to penetrate alveolar spaces and capillary walls of the lung when inhaled. A significant immuno-stimulatory component of AMP is lipopolysaccharide (LPS), a product of Gram negative bacteria breakdown. As LPS is implicated in the onset and exacerbation of asthma, the presence or absence of LPS in ambient particulate matter (PM) may explain the onset of asthmatic exacerbations to PM exposure. This study aimed to delineate the effects of LPS and AMP on airway inflammation, and potential contribution to airways disease by measuring airway inflammatory responses induced via activation of the LPS cellular receptor, Toll-like receptor 4 (TLR-4). The effects of nebulized AMP, LPS and AMP administered with LPS on lung function, cellular inflammatory infiltrate and cytokine responses were compared between wildtype mice and mice not expressing TLR-4. The presence of LPS administered with AMP appeared to drive elevated airway resistance and sensitivity via TLR-4. Augmented TLR4 driven eosinophilia and greater TNF-α responses observed in AMP-LPS treated mice independent of TLR-4 expression, suggests activation of allergic responses by TLR4 and non-TLR4 pathways larger than those induced by LPS administered alone. Treatment with AMP induced macrophage recruitment independent of TLR-4 expression. These findings suggest AMP-LPS as a stronger stimulus for allergic inflammation in the airways then LPS alone.

  2. Real-time imaging reveals endothelium-mediated leukocyte retention in LPS-treated lung microvessels

    Science.gov (United States)

    Kandasamy, Kathirvel; Sahu, Geetaram; Parthasarathi, Kaushik

    2012-01-01

    Endotoxemia, a major feature of sepsis, is a common cause of acute lung injury and initiates rapid accumulation of leukocytes in the lung vasculature. Endothelial mechanisms that underlie this accumulation remain unclear, as current experimental models of endotoxemia are less suitable for targeted activation of the endothelium. Toward elucidating this, we used the isolated blood-perfused rat lung preparation. With a microcatheter inserted through a left atrial cannula, we cleared blood cells from a small lung region and then infused lipopolysaccharide (LPS) into microvessels. After a Ringer’s wash to remove residual LPS, we infused fluorescently-labeled autologous leukocytes and imaged their transit through the treated microvessels. Image analysis revealed that leukocytes infused 90 min after LPS treatment, were retained more in treated venules and capillaries than untreated vessels. Further, pretreatment with either the intercellular adhesion molecule (ICAM-1) mAb or polymyxin-B blunted LPS-induced leukocyte retention in both microvessel segments. In addition, retention of leukocytes treated ex vivo with LPS in LPS-treated microvessels was higher compared to retention of untreated leukocytes. In situ immunofluorescence experiments revealed that LPS significantly increased microvessel ICAM-1 expression at 90 min post treatment. Polymyxin pretreatment inhibited this increase. Taken together, the data suggest that LPS increased leukocyte retention in both venules and capillaries and this response was mediated by the increased expression of endothelial ICAM1. Thus, endothelial mechanisms may themselves play a major role in LPS-induced leukocyte retention in lung microvessels. Blunting the endothelial responses may mitigate endotoxin-induced morbidity. PMID:22342350

  3. Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Lingling [Department of Pediatrics, Jingjiang People' s Hospital, Yangzhou University, Jingjiang 214500 (China); Noncoding RNA Center, Yangzhou University, Yangzhou 225001 (China); Zhao, Yingmin [Department of Pediatrics, Jingjiang People' s Hospital, Yangzhou University, Jingjiang 214500 (China); Gu, Xin; Wang, Jijun; Pang, Lei; Zhang, Yanqing; Li, Yaoyao; Jia, Xiaoqin; Wang, Xin [Noncoding RNA Center, Yangzhou University, Yangzhou 225001 (China); Gu, Jian [Department of Hematology, Yangzhou University School of Clinical Medicine, Yangzhou 225001 (China); Yu, Duonan, E-mail: duonan@yahoo.com [Department of Pediatrics, Jingjiang People' s Hospital, Yangzhou University, Jingjiang 214500 (China); Noncoding RNA Center, Yangzhou University, Yangzhou 225001 (China); Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Disease, Yangzhou 225001 (China); Institute of Comparative Medicine, Yangzhou University, Yangzhou 225001 (China); Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou 225001 (China)

    2016-06-10

    Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feeder layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment. - Highlights: • LPS alone in culture is required for the proliferation of murine myeloid tumor cells. • Bone marrow stromal cells as a feeder layer is also required for the proliferation of myeloid tumor cells. • However, the growth of myeloid tumor cells is inhibited when LPS and stromal cells are both available in culture. • Thus LPS can either facilitate or attenuate tumor growth through its direct effect or modulation of tumor microenvironment.

  4. Propofol inhibits LPS-induced apoptosis in lung epithelial cell line, BEAS-2B.

    Science.gov (United States)

    Lv, Xiang; Zhou, Xuhui; Yan, Jia; Jiang, Jue; Jiang, Hong

    2017-03-01

    Lipopolysaccharide (LPS) plays an important role in lung endothelial apoptosis which is crucial for lung fibrogenesis in ARDS progression. Reactive oxygen species (ROS) has been reported to be involved in LPS-induced lung epithelial cell apoptosis. Propofol is a commonly used intravenous anesthetic agent in clinic and it could attenuate LPS-induced epithelial cells oxidation and apoptosis. However, the mechanisms are still obscure. In this study, we examined whether and how propofol attenuates LPS-induced oxidation and apoptosis in BEAS-2B cells. Compared with control group, LPS up-regulated Pin-1, phosphatase A2 (PP2A) expression, induced p66 Shc -Ser 36 phosphorylation, and facilitated p66 Shc mitochondrial translocation, thus leading to superoxide anion (O 2 - ) generation, mitochondrial cytochrome c release, active caspase 3 over-expression and cell viability inhibition. Importantly, propofol was shown to down-regulate LPS-induced PP2A expression, limit p66 Shc mitochondrial translocation, decrease O 2 - generation, inhibit mitochondrial cytochrome c release, reduce active caspase 3 expression, and recover cells viability, while propofol had no effects on LPS-induced Pin-1 expression and p66 Shc -Ser 36 phosphorylation. Moreover, the protective effects of propofol on LPS-induced BEAS-2B cells apoptosis were similar to that of calyculin A, which is an inhibitor of PP2A. We also found that FTY720, which is an activator of PP2A, can effectively reverse the protective function of propofol. Our data illustrated that propofol could alleviate LPS-induced BEAS-2B cells oxidation and apoptosis through down-regulating PP2A expression, limiting p66 Shc -Ser 36 dephosphorylation and p66 Shc mitochondrial translocation, decreasing O 2 - generation, mitochondrial cytochrome c release, activating caspase 3 expression. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Dexmedetomidine alleviates LPS-induced septic cardiomyopathy via the cholinergic anti-inflammatory pathway in mice.

    Science.gov (United States)

    Kong, Weilan; Kang, Kai; Gao, Yang; Liu, Haitao; Meng, Xianglin; Yang, Songliu; Yu, Kaijiang; Zhao, Mingyan

    2017-01-01

    This study was conducted to investigate the role of the cholinergic anti-inflammatory pathway in LPS-induced septic cardiomyopathy in mice. C57BL/6 mice were used to construct septic cardiomyopathy models. The optimal duration of lipopolysaccharide (LPS) treatment was determined by HE staining and TUNEL assay. Blank controls were intraperitoneally injected with saline and models were injected with LPS (10 mg/kg) (LPS), α-bungarotoxin (BT-LPS), BT and dexmedetomidine (BT-DEX-LPS). The pathological examinations were performed on HE- stained myocardium tissues, apoptosis was determined using TUNEL assay, mRNA expression of NF-κB p65, Caspase-3, Caspase-8, Bcl-2, Bax, p53 and α7nACh was quantified using qRT-PCR, protein levels of IL-6, IL-1β, TNF-α and phosphorylated STAT3 (p-STAT3) were analyzed using Western blot analysis. HE staining and TUNEL assays showed that the optimal LPS treatment time for septic cardiomyopathy induction was 16 h. Compared with the blank control, mice in LPS group had significantly higher apoptosis, while DEX and BT reduced apoptosis when they were used separately and increased apoptosis when they were used jointly. In the LPS-treated mice, the levels of NF-κb p65, Caspase-3, Caspase-8, Bax, p53, IL-6, IL-1β, TNF-α and p-STAT3 were significantly increased, while α7nAChR level was decreased significantly ( P < 0.01); DEX alone had no impact on the expression of these proteins but significantly up-regulated the expression of these genes except α7nAChR when used jointly with BT ( P < 0.01). It is clear that DEX can alleviate heart injury, while α7nAChR-specific blocker BT is antagonistic against the anti-inflammatory effect of DEX on sepsis in mice.

  6. [Penehyclidine hydrochloride attenuates LPS-induced acute lung injury in rats].

    Science.gov (United States)

    Guo, Yan; Wei, Min; Yan, Zhiqiang; Wang, Guoxia

    2017-11-01

    Objective To study the protective effect of penehyclidine hydrochloride (PHCD) against acute lung injury induced by lipopolysaccharide (LPS) in rats. Methods 36 Sprague Dawley (SD) rats were randomly divided into control group, LPS-induced shock group (LPS group), and PHCD treated group (PHCD group). Rat shock model was prepared by intraperitoneal injection of LPS (5 mg/kg). The rats of PHCD group were treated with PHCD (1.0 mg/kg) by caudal vein injection. Rat blood gas analysis was performed 6 hours after the injection. Lung wet/dry mass ratio (W/D) was detected after the rats were sacrificed. The levels of tumor necrosis factor α (TNF-α), interleukin 8 (IL-8), and IL-6 in bronchoalveolar lavage fluid (BALF) were tested by ELISA. The lung tissue inflammation was observed by HE staining. The expression of inducible nitric oxide synthase (iNOS) was detected by real-time quantitative PCR and Western blot analysis. Results Compared with the control group, lung W/D and blood lactate acid (LAC) increased significantly in the LPS group, while the blood pH and the arterial oxygen partial pressure (PaO 2 ) decreased markedly. The levels of TNF-α, IL-8 and IL-6 significantly increased in lung BALF of the LPS-induced rats, and the expression of iNOS increased significantly. HE staining showed that LPS treatment caused pulmonary edema, congestion and inflammatory cell infiltration. After PHCD treatment, lung W/D and LAC were reduced; the pH and PaO 2 were elevated compared with LPS-induced rats; the levels of TNF-α, IL-8 and IL-6 in BALF were evidently down-regulated; the expression of iNOS decreased obviously. HE staining showed that the lung inflammation was attenuated by PHCD treatment. Conclusion PHCD attenuates lung injury by inhibiting LPS-induced lung inflammation.

  7. Role of xanthine oxidase and reactive oxygen intermediates in LPS- and TNF-induced pulmonary edema.

    Science.gov (United States)

    Faggioni, R; Gatti, S; Demitri, M T; Delgado, R; Echtenacher, B; Gnocchi, P; Heremans, H; Ghezzi, P

    1994-03-01

    We studied the role of reactive oxygen intermediates (ROI) in lipopolysaccharide (LPS)-induced pulmonary edema. LPS treatment (600 micrograms/mouse, IP) was associated with a marked induction of the superoxide-generating enzyme xanthine oxidase (XO) in serum and lung. Pretreatment with the antioxidant N-acetylcysteine (NAC)--1 gm/kg orally, 45 minutes before LPS--or with the XO inhibitor allopurinol (AP)--50 mg/kg orally at -1 hour and +3 hours--was protective. On the other hand nonsteroidal antiinflammatory drugs (ibuprofen, indomethacin, and nordihydroguaiaretic acid) were ineffective. These data suggested that XO might be involved in the induction of pulmonary damage by LPS. However, treatment with the interferon inducer polyriboinosylic-polyribocytidylic acid, although inducing XO to the same extent as LPS, did not cause any pulmonary edema, indicating that XO is not sufficient for this toxicity of LPS. To define the possible role of cytokines, we studied the effect of direct administration of LPS (600 micrograms/mouse, IP), tumor necrosis factor (TNF, 2.5 or 50 micrograms/mouse, IV), interleukin-1 (IL-1 beta, 2.5 micrograms/mouse, IV), interferon-gamma (IFN-gamma, 2.5 micrograms/mouse, IV), or their combination at 2.5 micrograms each. In addition to LPS, only TNF at the highest dose induced pulmonary edema 24 hours later. LPS-induced pulmonary edema was partially inhibited by anti-IFN-gamma antibodies but not by anti-TNF antibodies, anti-IL-1 beta antibodies, or IL-1 receptor antagonist (IL-1Ra).

  8. Tanshinone IIA Sodium Sulfonate Attenuates LPS-Induced Intestinal Injury in Mice

    Directory of Open Access Journals (Sweden)

    Xin-Jing Yang

    2018-01-01

    Full Text Available Background. Tanshinone IIA sodium sulfonate (TSS is known to possess anti-inflammatory effects and has exhibited protective effects in various inflammatory conditions; however, its role in lipopolysaccharide- (LPS- induced intestinal injury is still unknown. Objective. The present study is designed to explore the role and possible mechanism of TSS in LPS-induced intestinal injury. Methods. Male C57BL/6J mice, challenged with intraperitoneal LPS injection, were treated with or without TSS 0.5 h prior to LPS exposure. At 1, 6, and 12 h after LPS injection, mice were sacrificed, and the small intestine was excised. The intestinal tissue injury was analyzed by HE staining. Inflammatory factors (TNF-α, IL-1β, and IL-6 in the intestinal tissue were examined by ELISA and RT-PCR. In addition, expressions of autophagy markers (microtubule-associated light chain 3 (LC3 and Beclin-1 were detected by western blot and RT-PCR. A number of autophagosomes were also observed under electron microscopy. Results. TSS treatment significantly attenuated small intestinal epithelium injury induced by LPS. LPS-induced release of inflammatory mediators, including TNF-α, IL-1β, and IL-6, were markedly inhibited by TSS. Furthermore, TSS treatment could effectively upregulate LPS-induced decrease of autophagy levels, as evidenced by the increased expression of LC3 and Beclin-1, and more autophagosomes. Conclusion. The protective effect of TSS on LPS-induced small intestinal injury may be attributed to the inhibition of inflammatory factors and promotion of autophagy levels. The present study may provide novel insight into the molecular mechanisms of TSS on the treatment of intestinal injury.

  9. Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

    International Nuclear Information System (INIS)

    Yu, Lingling; Zhao, Yingmin; Gu, Xin; Wang, Jijun; Pang, Lei; Zhang, Yanqing; Li, Yaoyao; Jia, Xiaoqin; Wang, Xin; Gu, Jian; Yu, Duonan

    2016-01-01

    Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feeder layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment. - Highlights: • LPS alone in culture is required for the proliferation of murine myeloid tumor cells. • Bone marrow stromal cells as a feeder layer is also required for the proliferation of myeloid tumor cells. • However, the growth of myeloid tumor cells is inhibited when LPS and stromal cells are both available in culture. • Thus LPS can either facilitate or attenuate tumor growth through its direct effect or modulation of tumor microenvironment.

  10. AWRK6, A Synthetic Cationic Peptide Derived from Antimicrobial Peptide Dybowskin-2CDYa, Inhibits Lipopolysaccharide-Induced Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Qiuyu Wang

    2018-02-01

    Full Text Available Lipopolysaccharides (LPS are major outer membrane components of Gram-negative bacteria and produce strong inflammatory responses in animals. Most antibiotics have shown little clinical anti-endotoxin activity while some antimicrobial peptides have proved to be effective in blocking LPS. Here, the anti-LPS activity of the synthetic peptide AWRK6, which is derived from antimicrobial peptide dybowskin-2CDYa, has been investigated in vitro and in vivo. The positively charged α-helical AWRK6 was found to be effective in blocking the binding of LBP (LPS binding protein with LPS in vitro using ELISA. In a murine endotoxemia model, AWRK6 offered satisfactory protection efficiency against endotoxemia death, and the serum levels of LPS, IL-1β, IL-6, and TNF-α were found to be attenuated using ELISA. Further, histopathological analysis suggested that AWRK6 could improve the healing of liver and lung injury in endotoxemia mice. The results of real-time PCR and Western blotting showed that AWRK6 significantly reversed LPS-induced TLR4 overexpression and IκB depression, as well as the enhanced IκB phosphorylation. Additionally, AWRK6 did not produce any significant toxicity in vivo and in vitro. In summary, AWRK6 showed efficacious protection from LPS challenges in vivo and in vitro, by blocking LPS binding to LBP, without obvious toxicity, providing a promising strategy against LPS-induced inflammatory responses.

  11. Impact of bacteria and bacterial components on osteogenic and adipogenic differentiation of adipose-derived mesenchymal stem cells

    International Nuclear Information System (INIS)

    Fiedler, Tomas; Salamon, Achim; Adam, Stefanie; Herzmann, Nicole; Taubenheim, Jan; Peters, Kirsten

    2013-01-01

    Adult mesenchymal stem cells (MSC) are present in several tissues, e.g. bone marrow, heart muscle, brain and subcutaneous adipose tissue. In invasive infections MSC get in contact with bacteria and bacterial components. Not much is known about how bacterial pathogens interact with MSC and how contact to bacteria influences MSC viability and differentiation potential. In this study we investigated the impact of three different wound infection relevant bacteria, Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes, and the cell wall components lipopolysaccharide (LPS; Gram-negative bacteria) and lipoteichoic acid (LTA; Gram-positive bacteria) on viability, proliferation, and osteogenic as well as adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells (adMSC). We show that all three tested species were able to attach to and internalize into adMSC. The heat-inactivated Gram-negative E. coli as well as LPS were able to induce proliferation and osteogenic differentiation but reduce adipogenic differentiation of adMSC. Conspicuously, the heat-inactivated Gram-positive species showed the same effects on proliferation and adipogenic differentiation, while its cell wall component LTA exhibited no significant impact on adMSC. Therefore, our data demonstrate that osteogenic and adipogenic differentiation of adMSC is influenced in an oppositional fashion by bacterial antigens and that MSC-governed regeneration is not necessarily reduced under infectious conditions. - Highlights: • Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli bind to and internalize into adMSC. • Heat-inactivated cells of these bacterial species trigger proliferation of adMSC. • Heat-inactivated E. coli and LPS induce osteogenic differentiation of adMSC. • Heat-inactivated E. coli and LPS reduce adipogenic differentiation of adMSC. • LTA does not influence adipogenic or osteogenic differentiation of adMSC

  12. Impact of bacteria and bacterial components on osteogenic and adipogenic differentiation of adipose-derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, Tomas, E-mail: tomas.fiedler@med.uni-rostock.de [Institute for Medical Microbiology, Virology, and Hygiene, Rostock University Medical Center, Schillingallee 70, D-18057 Rostock (Germany); Salamon, Achim; Adam, Stefanie; Herzmann, Nicole [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Taubenheim, Jan [Institute for Medical Microbiology, Virology, and Hygiene, Rostock University Medical Center, Schillingallee 70, D-18057 Rostock (Germany); Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Peters, Kirsten [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany)

    2013-11-01

    Adult mesenchymal stem cells (MSC) are present in several tissues, e.g. bone marrow, heart muscle, brain and subcutaneous adipose tissue. In invasive infections MSC get in contact with bacteria and bacterial components. Not much is known about how bacterial pathogens interact with MSC and how contact to bacteria influences MSC viability and differentiation potential. In this study we investigated the impact of three different wound infection relevant bacteria, Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes, and the cell wall components lipopolysaccharide (LPS; Gram-negative bacteria) and lipoteichoic acid (LTA; Gram-positive bacteria) on viability, proliferation, and osteogenic as well as adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells (adMSC). We show that all three tested species were able to attach to and internalize into adMSC. The heat-inactivated Gram-negative E. coli as well as LPS were able to induce proliferation and osteogenic differentiation but reduce adipogenic differentiation of adMSC. Conspicuously, the heat-inactivated Gram-positive species showed the same effects on proliferation and adipogenic differentiation, while its cell wall component LTA exhibited no significant impact on adMSC. Therefore, our data demonstrate that osteogenic and adipogenic differentiation of adMSC is influenced in an oppositional fashion by bacterial antigens and that MSC-governed regeneration is not necessarily reduced under infectious conditions. - Highlights: • Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli bind to and internalize into adMSC. • Heat-inactivated cells of these bacterial species trigger proliferation of adMSC. • Heat-inactivated E. coli and LPS induce osteogenic differentiation of adMSC. • Heat-inactivated E. coli and LPS reduce adipogenic differentiation of adMSC. • LTA does not influence adipogenic or osteogenic differentiation of adMSC.

  13. Examination of chlorpromazine and other amphipathic drugs on the activity of lipopolysaccharide antagonists, E5564 and E5531.

    Science.gov (United States)

    Yang, H; Daun, J M; Rose, J R; Christ, W J; Gusovsky, F; Chow, J C

    2000-01-01

    The synthetic antagonists of lipopolysaccharide (LPS), E5531 and E5564, are analogs of the lipid A portion of LPS that not only lack agonistic activity but also inhibit the biological effects of LPS both in vitro and in vivo. The effects of LPS and these synthetic antagonists have been localized to the recently described Toll-like receptor 4 (TLR4). A recent report indicated that the naturally occurring LPS antagonist Rhodobacter sphaeroides LPS loses its antagonist properties and gains pro-inflammatory qualities in the presence of chlorpromazine and other amphipathic drugs. To determine whether these reported actions occur with our chemically defined LPS antagonists, we examined the effects of chlorpromazine, fluphenazine, trifluoperazine, and lidocaine on the antagonism elicited by RsLPS and E5531 in U373 cells, which produce IL-6 in response to LPS. We also tested the effects of these amphipathic molecules on the LPS-neutralizing activity of RsLPS and E5564 on LPS-induced TNF-alpha release in human whole blood. The results indicate that neither chlorpromazine, fluphenazine, trifluoperazine nor lidocaine alter the activity of E5531 or E5564 in an in vitro cell system or human whole blood. Furthermore, chlorpromazine did not affect the antagonistic activity of RsLPS or E5564 on IL-6 generation by peripheral blood mononuclear cells. Thus, based on these data, our purified synthetic LPS-antagonists do not appear to lose their antagonistic properties and/or become agonists in the presence of amphipathic agents or drugs.

  14. Effect of lipopolysaccharide on inflammation and insul