Lipopolysaccharide: a Link between Periodontitis and Cardiometabolic Disorders

OpenAIRE

Kallio, Elisa

2014-01-01

Periodontitis is characterized by an inflammatory response to bacterial infection in the supporting tissues of the teeth. The disease manifests with gingival swelling and bleeding, increased periodontal pocket depth, and alveolar bone loss. Intact bacteria or bacterial products, including lipopolysaccharide (LPS), may enter the bloodstream through inflamed periodontal tissue or via saliva. Bacterial dissemination, further potentiated by gastrointestinal microbiota, may result in endotoxemia a...

Intratracheal administration of bacterial lipopolysaccharide elicits pulmonary hypertension in broilers with primed airways.

Science.gov (United States)

Lorenzoni, A G; Wideman, R F

2008-04-01

Broilers reared under commercial conditions inhale irritant gases and aerosolized particulates contaminated with gram-negative bacteria and bacterial lipopolysaccharide (LPS). Previous studies demonstrated that i.v. injections of LPS can trigger an increase in the pulmonary arterial pressure (PAP); however, the pulmonary hemodynamic response to aerosolized LPS entering via the most common route, the respiratory tract, had not been evaluated in broilers. In experiment 1, broilers reared on new wood shavings litter in clean environmental chambers either were not pretreated (control group) or were pretreated via aerosol inhalation of substances (food color dyes and propylene glycol) known to sensitize the airways. One day later, the broilers were anesthetized, catheterized to record the PAP, and an intratracheal aerosol spray of LPS (1 mL of 2 mg/mL of LPS) was administered. Broilers in the control group as well as broilers pretreated with aerosolized distilled water or yellow and blue food color dyes did not develop pulmonary hypertension (PH; an increase in PAP) after the intratracheal spray of LPS, whereas broilers that had been pretreated with red food color did develop PH in response to intratracheal LPS. In experiment 2, birds raised under commercial conditions on used wood shavings litter developed PH in response to intratracheal LPS regardless of whether they had been pretreated with aerosolized red food color dye. In experiment 3, broilers reared in clean environmental chambers on new wood shavings litter were used to demonstrate that Red Dye #3 and propylene glycol are capable of priming the responsiveness of the airways to a subsequent intratracheal LPS challenge. Common air contaminants such as LPS can result in PH leading to pulmonary hypertension syndrome (ascites) in broilers with appropriately primed airways.

Effect of chocolate and Propolfenol on rabbit spermatogenesis and sperm quality following bacterial lipopolysaccharide treatment.

Science.gov (United States)

Collodel, Giulia; Moretti, Elena; Del Vecchio, Maria Teresa; Biagi, Marco; Cardinali, Raffaella; Mazzi, Lucia; Brecchia, Gabriele; Maranesi, Margherita; Manca, Daniela; Castellini, Cesare

2014-08-01

The aims of the study were to evaluate the effects of chocolate and propolis-enriched diets on rabbit spermatogenesis, sperm motility, and ultrastructure following bacterial lipopolysaccharide (LPS) treatment. Thirty-two New Zealand White rabbits were divided into four groups. The LPS-Propolfenol(®) group received propolis (500 mg/kg/day) in their diet for 15 days, while the LPS-chocolate group was fed 70% cacao chocolate (1 g/1 kg/day) for the same period. Following the diet treatments, rabbits in the LPS-Propolfenol(®) and LPS-chocolate groups, and an LPS group received a single intraperitoneal dose of 50 μg/kg LPS, and the control group received only saline. Kinematic sperm traits were evaluated with a computer assisted sperm analyzer (CASA) system, and ultrastructural characteristics were examined by transmission electron microscopy (TEM). Testicular and epididymal tissues were observed by light microscopy and TEM and multiplex real time reverse transcriptase-polymerase chain reaction (RT-PCR) assay was used to detect and quantify toll-like receptor-4 (TLR-4) gene expression. The values of the analyzed semen parameters of rabbits treated with LPS-Propolfenol(®) and LPS-chocolate did not show any variations compared with the control group, but they were lower in rabbits treated only with LPS. Alterations observed in the testicular tissue of LPS treated-rabbits were not detected in specimens from the LPS-chocolate and LPS-Propolfenol(®) groups, which showed normal spermatogenesis. The TLR-4 mRNA expression was similar in controls, in LPS treated, and in LPS-chocolate groups, but it was significantly (p chocolate and propolis-enriched diet showed a protective effect on the spermatogenetic process of buck rabbits following LPS treatment.

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 ...

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, ...

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 Title Structural and functi...onal analyses of bacterial lipopolysaccharides. Authors

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...

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.

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

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

Lipopolysaccharide (LPS) of Porphyromonas gingivalis induces IL-1beta, TNF-alpha and IL-6 production by THP-1 cells in a way different from that of Escherichia coli LPS.

Science.gov (United States)

Diya Zhang; Lili Chen; Shenglai Li; Zhiyuan Gu; Jie Yan

2008-04-01

Lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis has been shown to differ from enterobacterial LPS in structure and function; therefore, the Toll-like receptors (TLRs) and the intracellular inflammatory signaling pathways are accordingly different. To elucidate the signal transduction pathway of P. gingivalis, LPS-induced pro-inflammatory cytokine production in the human monocytic cell line THP-1 was measured by ELISA, and the TLRs were determined by the blocking test using anti-TLRs antibodies. In addition, specific inhibitors as well as Phospho-ELISA kits were used to analyze the intracellular signaling pathways. Escherichia coli LPS was used as the control. In this study, P. gingivalis LPS showed the ability to induce cytokine production in THP-1 cells and its induction was significantly (P THP-1 cells, and that the TLR2-JNK pathway might play a significant role in P. gingivalis LPS-induced chronic inflammatory periodontal disease.

Application of bacterial lipopolysaccharide to improve survival of the black tiger shrimp after Vibrio harveyi exposure.

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Rungrassamee, Wanilada; Maibunkaew, Sawarot; Karoonuthaisiri, Nitsara; Jiravanichpaisal, Pikul

2013-10-01

This study investigates an effect of bacterial lipopolysaccharide (LPS) as feed supplement to improve immunity of the black tiger shrimp (Penaeus monodon). LPS was coated to commercial feed pellets and given to the shrimp once or twice a day for 10 days before an exposure with shrimp pathogenic bacterium Vibrio harveyi. The growth rates, percent weight gains, total hemocyte and granulocyte counts and survival rates of shrimp between the LPS-coated pellet fed groups and a control group where shrimp fed with commercial feed pellets were compared. After 10 days of the feeding trials, growth rates were not significantly different in all groups, suggesting no toxicity from LPS supplement. To determine beneficial effect of LPS diets, each group was subsequently exposed to V. harveyi by immersion method and the survival rates were recorded for seven days after the immersion. Regardless of the dosages of LPS, the shrimp groups fed with LPS-coated pellets showed higher survival rates than the control group. There was no significant difference in survival rates between the two LPS dosages groups. In addition to survival under pathogen challenge, we also determine effect of LPS on immune-related genes after 10-day feeding trial. Gene expression analysis in the P. monodon intestines revealed that antilipopolysaccharide factor isoform 3 (ALF3), C-type lectin, and mucine-like peritrophin (mucin-like PM) were expressed significantly higher in a group fed with LPS supplemental diet once or twice a day than in a control group. The transcript levels of C-type lectin and mucin-like PM had increased significantly when LPS was given once a day, while significant induction of ALF3 transcripts was observed when shrimp were fed with LPS twice a day. The up-regulation of the immune gene levels in intestines and higher resistance to V. harveyi of the shrimp fed with LPS provide the evidence for potential application of LPS as an immunostimulant in P. monodon farming. Copyright © 2013

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

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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.

Stress hormone release is a key component of the metabolic response to lipopolysaccharide (LPS): studies in hypopituitary and healthy subjects

DEFF Research Database (Denmark)

Bach, Ermina; Møller, Andreas Buch; Jørgensen, Jens Otto Lunde

2016-01-01

OBJECTIVE: Lipopolysaccharide (LPS) generates acute and chronic inflammatory and metabolic responses during acute illness and in the pathogenesis of the metabolic syndrome, type 2 diabetes and cardiovascular disease, but it is unclear whether these responses depend on intact pituitary release...... but not in HP. LPS increased whole body palmitate fluxes (3-fold) and decreased palmitate specific activity 40-50 % in CTR, but not in HP. G(0)/G(1) Switch Gene 2 (G0S2 - an inhibitor of lipolysis) adipose tissue mRNA was decreased in CTR. LPS increased phenylalanine fluxes significantly more in CTR, whereas...

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)

Extract of corn silk (stigma of Zea mays) inhibits the tumour necrosis factor-alpha- and bacterial lipopolysaccharide-induced cell adhesion and ICAM-1 expression.

Science.gov (United States)

Habtemariam, S

1998-05-01

Treatment of human endothelial cells with cytokines such as tumour necrosis factor-alpha (TNF) or E. coli lipopolysaccharide (LPS) induces the expression of several adhesion molecules and enhances leukocyte adhesion to endothelial cell surface. Interfering with this leukocyte adhesion or adhesion molecules upregulation is an important therapeutic target for the treatment of bacterial sepsis and various inflammatory diseases. In the course of screening marketed European anti-inflammatory herbal drugs for TNF antagonistic activity, a crude ethanolic extract of corn silk (stigma of Zea mays) exhibited significant activity. The extract at concentrations of 9-250 micrograms/ml effectively inhibited the TNF- and LPS-induced adhesiveness of EAhy 926 endothelial cells to monocytic U937 cells. Similar concentration ranges of corn silk extract did also block the TNF and LPS but not the phorbol 12-myristate 13-acetate-induced ICAM-1 expression on EAhy 926 endothelial cell surface. The extract did not alter the production of TNF by LPS-activated macrophages and failed to inhibit the cytotoxic activity of TNF. It is concluded that corn silk possesses important therapeutic potential for TNF- and LPS-mediated leukocyte adhesion and trafficking.

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

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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.

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

International Nuclear Information System (INIS)

Laude-Sharp, M.; Caroff, M.; Simard, L.; Pusineri, C.; Kazatchkine, M.D.; Haeffner-Cavaillon, N.

1990-01-01

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

Lipopolysaccharide-induced Pulpitis Up-regulates TRPV1 in Trigeminal Ganglia

Science.gov (United States)

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

Aggregatibacter actinomycetemcomitans lipopolysaccharide affects human gingival fibroblast cytoskeletal organization.

Science.gov (United States)

Gutiérrez-Venegas, Gloria; Contreras-Marmolejo, Luis Arturo; Román-Alvárez, Patricia; Barajas-Torres, Carolina

2008-04-01

The cytoskeleton is a dynamic structure that plays a key role in maintaining cell morphology and function. This study investigates the effect of bacterial wall lipopolysaccharide (LPS), a strong inflammatory agent, on the dynamics and organization of actin, tubulin, vimentin, and vinculin proteins in human gingival fibroblasts (HGF). A time-dependent study showed a noticeable change in actin architecture after 1.5 h of incubation with LPS (1 microg/ml) with the formation of orthogonal fibers and further accumulation of actin filament at the cell periphery by 24 h. When 0.01-10 microg/ml of LPS was added to human gingival fibroblast cultures, cells acquired a round, flat shape and gradually developed cytoplasmic ruffling. Lipopolysaccharides extracted from Aggregatibacter actinomycetemcomitans periodontopathogenic bacteria promoted alterations in F-actin stress fibres of human gingival cells. Normally, human gingival cells have F-actin fibres that are organized in linear distribution throughout the cells, extending along the cell's length. LPS-treated cells exhibited changes in cytoskeletal protein organization, and F-actin was reorganized by the formation of bundles underneath and parallel to the cell membrane. We also found the reorganization of the vimentin network into vimentin bundling after 1.5 h of treatment. HGF cells exhibited diffuse and granular gamma-tubulin stain. There was no change in LPS-treated HGF. However, vinculin plaques distributed in the cell body diminished after LPS treatment. We conclude that the dynamic and structured organization of cytoskeletal filaments and actin assembly in human gingival fibroblasts is altered by LPS treatment and is accompanied by a decrease in F-actin pools.

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.

Supramolecular structure of enterobacterial wild-type lipopolysaccharides (LPS), fractions thereof, and their neutralization by Pep19-2.5.

Science.gov (United States)

Brandenburg, Klaus; Heinbockel, Lena; Correa, Wilmar; Fukuoka, Satoshi; Gutsmann, Thomas; Zähringer, Ulrich; Koch, Michel H J

2016-04-01

Lipopolysaccharides (LPS) belong to the strongest immune-modulating compounds known in nature, and are often described as pathogen-associated molecular patterns (PAMPs). In particular, at higher concentrations they are responsible for sepsis and the septic shock syndrome associated with high lethality. Since most data are indicative that LPS aggregates are the bioactive units, their supramolecular structures are considered to be of outmost relevance for deciphering the molecular mechanisms of its bioactivity. So far, however, most of the data available addressing this issue, were published only for the lipid part (lipid A) and the core-oligosaccharide containing rough LPS, representing the bioactive unit. By contrast, it is well known that most of the LPS specimen identified in natural habitats contain the smooth-form (S-form) LPS, which carry additionally a high-molecular polysaccharide (O-chain). To fill this lacuna and going into a more natural system, here various wild-type (smooth form) LPS including also some LPS fractions were investigated by small-angle X-ray scattering with synchrotron radiation to analyze their aggregate structure. Furthermore, the influence of a recently designed synthetic anti-LPS peptide (SALP) Pep19-2.5 on the aggregate structure, on the binding thermodynamics, and on the cytokine-inducing activity of LPS were characterized, showing defined aggregate changes, high affinity binding and inhibition of cytokine secretion. The data obtained are suitable to refine our view on the preferences of LPS for non-lamellar structures, representing the highest bioactive forms which can be significantly influenced by the binding with neutralizing peptides such as Pep19-2.5. Copyright © 2016 Elsevier Inc. All rights reserved.

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

The effect of bacterial lipopolysaccharide on gastric emptying in rats suffering from moderate renal insufficiency

Directory of Open Access Journals (Sweden)

Rigatto S.Z.P.

1998-01-01

Full Text Available The objective of the present study was to evaluate the response of rats suffering from moderate renal insufficiency to bacterial lipopolysaccharide (LPS, or endotoxin. The study involved 48 eight-week-old male SPF Wistar rats (175-220 g divided into two groups of 24 animals each. One group underwent 5/6 nephrectomy while the other was sham-operated. Two weeks after surgery, the animals were further divided into two subgroups of 12 animals each and were fasted for 20 h but with access to water ad libitum. One nephrectomized and one sham-treated subgroup received E. coli LPS (25 µg/kg, iv while the other received a sterile, pyrogen-free saline solution. Gastric retention (GR was determined 10 min after the orogastric infusion of a standard saline test meal labeled with phenol red (6 mg/dl. The gastric emptying of the saline test meal was studied after 2 h. Renal function was evaluated by measuring the plasma levels of urea and creatinine. The levels of urea and creatinine in 5/6 nephrectomized animals were two-fold higher than those observed in the sham-operated rats. Although renal insufficiency did not change gastric emptying (median %GR = 26.6 for the nephrectomized subgroup and 29.3 for the sham subgroup, LPS significantly retarded the gastric emptying of the sham and nephretomized groups (median %GR = 42.0 and 61.0, respectively, and was significantly greater (P<0.01 in the nephrectomized rats. We conclude that gastric emptying in animals suffering from moderate renal insufficiency is more sensitive to the action of LPS than in sham animals

Lipopolysaccharide interactions of C-terminal peptides from human thrombin.

Science.gov (United States)

Singh, Shalini; Kalle, Martina; Papareddy, Praveen; Schmidtchen, Artur; Malmsten, Martin

2013-05-13

Interactions with bacterial lipopolysaccharide (LPS), both in aqueous solution and in lipid membranes, were investigated for a series of amphiphilic peptides derived from the C-terminal region of human thrombin, using ellipsometry, dual polarization interferometry, fluorescence spectroscopy, circular dichroism (CD), dynamic light scattering, and z-potential measurements. The ability of these peptides to block endotoxic effects caused by LPS, monitored through NO production in macrophages, was compared to peptide binding to LPS and its endotoxic component lipid A, and to size, charge, and secondary structure of peptide/LPS complexes. While the antiendotoxic peptide GKY25 (GKYGFYTHVFRLKKWIQKVIDQFGE) displayed significant binding to both LPS and lipid A, so did two control peptides with either selected D-amino acid substitutions or with maintained composition but scrambled sequence, both displaying strongly attenuated antiendotoxic effects. Hence, the extent of LPS or lipid A binding is not the sole discriminant for the antiendotoxic effect of these peptides. In contrast, helix formation in peptide/LPS complexes correlates to the antiendotoxic effect of these peptides and is potentially linked to this functionality. Preferential binding to LPS over lipid membrane was furthermore demonstrated for these peptides and preferential binding to the lipid A moiety within LPS inferred.

Involvement of JNK and NF-κB pathways in lipopolysaccharide (LPS)-induced BAG3 expression in human monocytic cells.

Science.gov (United States)

Wang, Hua-Qin; Meng, Xin; Liu, Bao-Qin; Li, Chao; Gao, Yan-Yan; Niu, Xiao-Fang; Li, Ning; Guan, Yifu; Du, Zhen-Xian

2012-01-01

Lipopolysaccharide (LPS) is an outer-membrane glycolipid component of Gram-negative bacteria known for its fervent ability to activate monocytic cells and for its potent proinflammatory capabilities. Bcl-2-associated athanogene 3 (BAG3) is a survival protein that has been shown to be stimulated during cell response to stressful conditions, such as exposure to high temperature, heavy metals, proteasome inhibition, and human immunodeficiency virus 1 (HIV-1) infection. In addition, BAG3 regulates replication of Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) replication, suggesting that BAG3 could participate in the host response to infection. In the current study, we found that LPS increased the expression of BAG3 in a dose- and time-dependent manner. Actinomycin D completely blocked the LPS-induced BAG3 accumulation, as well as LPS activated the proximal promoter of BAG3 gene, supported that the induction by LPS occurred at the level of gene transcription. LPS-induced BAG3 expression was blocked by JNK or NF-κB inhibition, suggesting that JNK and NF-κB pathways participated in BAG3 induction by LPS. In addition, we also found that induction of BAG3 was implicated in monocytic cell adhesion to extracellular matrix induced by LPS. Overall, the data support that BAG3 is induced by LPS via JNK and NF-κB-dependent signals, and involved in monocytic cell-extracellular matrix interaction, suggesting that BAG3 may have a role in the host response to LPS stimulation. Copyright © 2011 Elsevier Inc. All rights reserved.

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

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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.

Lipopolysaccharides of the cyanobacterium Microcystis aeruginosa

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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.

C–C Chemokines Released by Lipopolysaccharide (LPS)-stimulated Human Macrophages Suppress HIV-1 Infection in Both Macrophages and T Cells

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Verani, Alessia; Scarlatti, Gabriella; Comar, Manola; Tresoldi, Eleonora; Polo, Simona; Giacca, Mauro; Lusso, Paolo; Siccardi, Antonio G.; Vercelli, Donata

1997-01-01

Human immunodeficiency virus-1 (HIV-1) expression in monocyte-derived macrophages (MDM) infected in vitro is known to be inhibited by lipopolysaccharide (LPS). However, the mechanisms are incompletely understood. We show here that HIV-1 suppression is mediated by soluble factors released by MDM stimulated with physiologically significant concentrations of LPS. LPS-conditioned supernatants from MDM inhibited HIV-1 replication in both MDM and T cells. Depletion of C–C chemokines (RANTES, MIP-1α, and MIP-1β) neutralized the ability of LPS-conditioned supernatants to inhibit HIV-1 replication in MDM. A combination of recombinant C–C chemokines blocked HIV-1 infection as effectively as LPS. Here, we report an inhibitory effect of C–C chemokines on HIV replication in primary macrophages. Our results raise the possibility that monocytes may play a dual role in HIV infection: while representing a reservoir for the virus, they may contribute to the containment of the infection by releasing factors that suppress HIV replication not only in monocytes but also in T lymphocytes. PMID:9120386

Porphyromonas endodontalis lipopolysaccharides induce RANKL by mouse osteoblast in a way different from that of Escherichia coli lipopolysaccharide.

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Tang, Yin; Sun, Feifei; Li, Xiaoting; Zhou, Yuan; Yin, Shihai; Zhou, Xuedong

2011-12-01

Porphyromonas endodontalis lipopolysaccharide (LPS) has been shown to have a high positive rate in infected root canals and symptomatic apical periodontitis. It may play an integral role as a potent stimulator of inflammatory cytokines involved in apical lesions. The receptor activator of nuclear factor-κB ligand (RANKL) has been proven to be the key regulator of bone remodeling. This study investigated P. endodontalis LPS-induced RANKL production and LPS signaling in mouse osteoblasts. LPS-induced RANKL production in mouse osteoblast MC3T3-E1 cells was measured by Western blot and real-time polymerase chain reaction, and the Toll-like receptors (TLRs) were determined by the blocking test using anti-TLRs antibodies. In addition, specific inhibitors were used to analyze the intracellular signaling pathways. Escherichia coli LPS was used as the control. Both of the anti-TLR2 and anti-TLR4 antibodies significantly (P endodontalis LPS; only anti-TLR2 antibody had a significant (P endodontalis LPS-infected osteoblasts (P endodontalis LPS has the ability to promote the expression of RANKL in mouse osteoblasts, and this induction was mainly through the TLR2/4-JNK signaling pathway, a situation quite different from that of typical bacterial endotoxin (E. coli LPS). Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Lipopolysaccharide and Lipoteichoic Acid Virulence Deactivation by Stannous Fluoride.

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Haught, Chris; Xie, Sancai; Circello, Ben; Tansky, Cheryl S; Khambe, Deepa; Klukowska, Malgorzata; Huggins, Tom; White, Donald J

2016-09-01

Oral bacterial pathogens promote gingivitis and periodontal disease. Bacterial endotoxins, also known as lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), are known to enhance bacterial pathogenicity through binding with Toll-like receptors (TLRs), a group of pattern recognition receptors critical to the activation of innate immunity, that are expressed on host cells. Both LPS and LTA contain lipophilic domains and anionic charges that may be susceptible to reactivity with stannous fluoride, a commonly used ingredient clinically proven for the treatment and prevention of gingivitis. This study examined the effects of stannous fluoride on Toll-like receptor activation in response to bacterially derived LPS and LTA in select cell lines and secretion of inflammatory cytokines from human primary peripheral monocytes likewise exposed to LPS. TLR4 and TLR2 transfected HEK293 cells and THP1-Dual™ cells were exposed to bacterial LPS and LTA in the presence of increasing concentrations of stannous fluoride. Gene expression was assessed by measurement of secreted embryonic alkaline phosphatase (SEAP) reporter gene for HEK293 cells and SEAP and luciferase for THP-1 cells. Cell viability was confirmed using PrestoBlue. Human primary monocytes were treated with LPS with various concentrations of supplemented stannous fluoride, and cytokine expression was directly measured. Stannous fluoride inhibited gene expression response of TLR4 and TLR2 in HEK293 cells and THP1-Dual™ cells in a dose response fashion, producing complete inhibition at micromolar concentrations. The addition of stannous fluoride suppressed production of TNF-a, IFN-g, IL12p70, IL10, IL-1b, IL2, and IL-6, and also increased secretion of Il-8 in dose response fashion. Viability assays confirmed no effects of LPS or stannous fluoride on viability of HEK293, THP-1, and primary human monocytes. These results support the potential for stannous fluoride to provide clinical gingivitis benefits by directly

Structural Characterization of Core Region in Erwinia amylovora Lipopolysaccharide

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Angela Casillo

2017-03-01

Full Text Available Erwinia amylovora (E. amylovora is the first bacterial plant pathogen described and demonstrated to cause fire blight, a devastating plant disease affecting a wide range of species including a wide variety of Rosaceae. In this study, we reported the lipopolysaccharide (LPS core structure from E. amylovora strain CFBP1430, the first one for an E. amylovora highly pathogenic strain. The chemical characterization was performed on the mutants waaL (lacking only the O-antigen LPS with a complete LPS-core, wabH and wabG (outer-LPS core mutants. The LPSs were isolated from dry cells and analyzed by means of chemical and spectroscopic methods. In particular, they were subjected to a mild acid hydrolysis and/or a hydrazinolysis and investigated in detail by one and two dimensional Nuclear Magnetic Resonance (NMR spectroscopy and ElectroSpray Ionization Fourier Transform-Ion Cyclotron Resonance (ESI FT-ICR mass spectrometry.

Inhibition of TNF-alpha production contributes to the attenuation of LPS-induced hypophagia by pentoxifylline.

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Porter, M H; Hrupka, B J; Altreuther, G; Arnold, M; Langhans, W

2000-12-01

Cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) are assumed to mediate anorexia during bacterial infections. To improve our understanding of the role that these two cytokines serve in mediating infection during anorexia, we investigated the ability of pentoxifylline (PTX), a potent inhibitor of TNF-alpha production, to block the anorectic effects of the bacterial products lipopolysaccharide (LPS) and muramyl dipeptide (MDP) in rats. Intraperitoneally injected PTX (100 mg/kg body wt) completely eliminated the anorectic effect of intraperitoneally injected LPS (100 microg/kg body wt) and attenuated the anorectic effect of a higher dose of intraperitoneally injected LPS (250 microg/kg body wt). Concurrently, PTX pretreatment suppressed low-dose LPS-induced TNF-alpha production by more than 95% and IL-1beta production 39%, as measured by ELISA. Similarly, high-dose LPS-induced TNF-alpha production was reduced by approximately 90%. PTX administration also attenuated the tolerance that is normally observed with a second injection of LPS. In addition, PTX pretreatment attenuated the hypophagic effect of intraperitoneally injected MDP (2 mg/kg body wt) but had no effect on the anorectic response to intraperitoneally injected recombinant human TNF-alpha (150 ug/kg body wt). The results suggest that suppression of TNF-alpha production is sufficient to attenuate LPS- and MDP-induced anorexia. This is consistent with the hypothesis that TNF-alpha plays a major role in the anorexia associated with bacterial infection.

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

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

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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.

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

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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

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

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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.

Effects of lipopolysaccharide on the catabolic activity of macrophages

International Nuclear Information System (INIS)

Cluff, C.; Ziegler, H.K.

1986-01-01

The ability of macrophages to degrade and catabolize antigens is of relevance both as a means to process complex antigens prior to presentation to T cells, as well as a way to down regulate immune responses by destroying the antigenicity of polypeptides. With these considerations, the authors have investigated the regulation of macrophage catabolic activity by lipopolysaccharide (LPS). Catabolic activity was quantitated by following the distribution and molecular form of 125 -I labelled surface components of heat-killed Listeria monocytogenes (HKLM) subsequent to their uptake by macrophages. They have compared the catabolic activity of macrophages from peritoneal exudates of mice injected i.p. with saline or LPS and have found that LPS-elicited macrophages display a greatly enhanced (3 fold) rate of catabolism. This increase in catabolic activity peaks 3 days after LPS injection and steadily declines thereafter, approaching a baseline level after 3 weeks. The enhancement of catabolic activity is under LPS gene control. LPS-elicited macrophages rapidly destroy the antigenicity of bacterial antigens and function poorly as antigen presenting cells in vitro. These results suggest that LPS elicits a macrophage population specialized for antigen degradation functions with negative regulatory effects on the induction of specific immune responses

Lipopolysaccharides with acylation defects potentiate TLR4 signaling and shape T cell responses.

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Anna Martirosyan

Full Text Available Lipopolysaccharides or endotoxins are components of Gram-negative enterobacteria that cause septic shock in mammals. However, a LPS carrying hexa-acyl lipid A moieties is highly endotoxic compared to a tetra-acyl LPS and the latter has been considered as an antagonist of hexa-acyl LPS-mediated TLR4 signaling. We investigated the relationship between the structure and the function of bacterial LPS in the context of human and mouse dendritic cell activation. Strikingly, LPS with acylation defects were capable of triggering a strong and early TLR4-dependent DC activation, which in turn led to the activation of the proteasome machinery dampening the pro-inflammatory cytokine secretion. Upon activation with tetra-acyl LPS both mouse and human dendritic cells triggered CD4(+ T and CD8(+ T cell responses and, importantly, human myeloid dendritic cells favored the induction of regulatory T cells. Altogether, our data suggest that LPS acylation controlled by pathogenic bacteria might be an important strategy to subvert adaptive immunity.

Lipopolysaccharide Binding Protein Enables Intestinal Epithelial Restitution Despite Lipopolysaccharide Exposure

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Richter, Juli M.; Schanbacher, Brandon L.; Huang, Hong; Xue, Jianjing; Bauer, John A.; Giannone, Peter J.

2011-01-01

Intestinal epithelial restitution is the first part in the process of mucosal repair after injury in the intestine. Integrity of the intestinal mucosal barrier is important as a first line of defense against bacteria and endotoxin. Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in extremely low birth weight infants, but its mechanisms are not well defined. Abnormal bacterial colonization, immature barrier function, innate immunity activation and inflammation likely play a role. Lipopolysaccharide (LPS) binding protein (LBP) is secreted by enterocytes in response to inflammatory stimuli and has concentration-dependent effects. At basal concentrations, LBP stimulates the inflammatory response by presenting LPS to its receptor. However, at high concentrations, LBP is able to neutralize LPS and prevent an exaggerated inflammatory response. We sought to determine how LBP would affect wound healing in an in vitro model of intestinal cell restitution and protect against intestinal injury in a rodent model of NEC. Immature intestinal epithelial cells (IEC-6) were seeded in poly-l-lysine coated 8 chamber slides and grown to confluence. A 500μm wound was created using a cell scraper mounted on the microscope to achieve uniform wounding. Media was replaced with media containing LPS +/− LBP. Slide wells were imaged after 0, 8, and 24 hours and then fixed. Cellular restitution was evaluated via digital images captured on an inverted microscope and wound closure was determined by automated analysis. TLR4 was determined by rtPCR after RNA isolation from wounded cells 24 hours after treatment. LPS alone attenuated wound healing in immature intestinal epithelium. This attenuation is reversed by 24 hours with increasing concentrations of LBP so that wound healing is equivalent to control (p< 0.001). TLR4 was increased with LPS alone but levels returned to that of control after addition of LBP in the higher concentrations. LBP had no effect on the

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.

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

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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.

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.

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.

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.

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

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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.

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

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).

The Glycosyltransferases of LPS Core: A Review of Four Heptosyltransferase Enzymes in Context

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Joy M. Cote

2017-10-01

Full Text Available Bacterial antibiotic resistance is a rapidly expanding problem in the world today. Functionalization of the outer membrane of Gram-negative bacteria provides protection from extracellular antimicrobials, and serves as an innate resistance mechanism. Lipopolysaccharides (LPS are a major cell-surface component of Gram-negative bacteria that contribute to protecting the bacterium from extracellular threats. LPS is biosynthesized by the sequential addition of sugar moieties by a number of glycosyltransferases (GTs. Heptosyltransferases catalyze the addition of multiple heptose sugars to form the core region of LPS; there are at most four heptosyltransferases found in all Gram-negative bacteria. The most studied of the four is HepI. Cells deficient in HepI display a truncated LPS on their cell surface, causing them to be more susceptible to hydrophobic antibiotics. HepI–IV are all structurally similar members of the GT-B structural family, a class of enzymes that have been found to be highly dynamic. Understanding conformational changes of heptosyltransferases are important to efficiently inhibiting them, but also contributing to the understanding of all GT-B enzymes. Finding new and smarter methods to inhibit bacterial growth is crucial, and the Heptosyltransferases may provide an important model for how to inhibit many GT-B enzymes.

Effects of a bacterial lipopolysaccharide on the reproductive functions of rabbit does.

Science.gov (United States)

Brecchia, G; Menchetti, L; Cardinali, R; Castellini, C; Polisca, A; Zerani, M; Maranesi, M; Boiti, C

2014-06-30

Systemic and local infections and inflammations are known to cause infertility in humans and animals. However, the mechanisms by which infection/inflammation induces infertility are only partially known. The objectives of this study were: (i) to provide models of systemic (acute) and local (sub-acute) inflammation by intra-peritoneal injection or intra-cervical deposition of lipopolysaccharide (LPS) in the rabbit and (ii) to assess their effects on uterine tissues and sperm transport in the genital tract of rabbit does. Intra-peritoneal administration of different doses of LPS induced systemic effects such as fever, anorexia and changes in white blood cells (WBC) count. In our study, LPS inoculation (100μg/kg) produced an inflammation-like status that lasted for about 3 days, with minimal distress for the animals. Intra-peritoneal administration of LPS 60h before artificial insemination induced a rapid increase of IL-1β concentrations. The intra-cervical inoculation of LPS did not show any systemic effects, as confirmed by the lack of changes in body temperature, feed intake and WBC count. Histological examination of uterine tissues showed an endometritis-like inflammation status in LPS-treated does, more severe in those inoculated intra-cervically. The number of spermatozoa recovered from uterine horns and oviducts of intra-cervically treated does was less than that retrieved from intra-peritoneally treated animals and controls. These results suggest (i) that sub-acute or acute inflammation may cause infertility by compromising the uterine environment and/or impairing sperm transport and (ii) that the LPS-induced -infection/inflammation experimental model is useful for studying the mechanisms involved in reproductive dysfunctions in the rabbit. Copyright © 2014 Elsevier B.V. All rights reserved.

Transcriptional profiles of Rel/NF-κB, inhibitor of NF-κB (IκB), and lipopolysaccharide-induced TNF-α factor (LITAF) in the lipopolysaccharide (LPS) and two Vibrio sp.-exposed intertidal copepod, Tigriopus japonicus.

Science.gov (United States)

Kim, Bo-Mi; Jeong, Chang-Bum; Rhee, Jae-Sung; Lee, Jae-Seong

2014-02-01

The immune system and the role of immunity-related genes have rarely been studied in copepods, even though copepods have a primitive immune response system and also have a potential in pathogen transport higher trophic levels. In this study, we firstly cloned and characterized three core immune genes such as nuclear factor κB (NF-κB), inhibitor of NF-κB (IκB), and lipopolysaccharide-induced TNF-α factor (LITAF) genes in the intertidal copepod Tigriopus japonicus. Several in silico analyses based on conserved domains, motifs, and phylogenetic relationships were supporting their annotations. To investigate the immune-related role of three genes, we exposed lipopolysaccharide (LPS) and two Vibrio sp. to T. japonicus. After exposure of different concentrations of LPS and two Vibrio sp., transcripts of TJ-IκB and TJ-LITAF genes were significantly elevated during the time course in a dose-dependent manner, while TJ-NF-κB transcripts were not significantly changed during exposure. These findings demonstrated that the copepod T. japonicus has a conserved immunity against infection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterizing the effect of polymyxin B antibiotics to lipopolysaccharide on Escherichia coli surface using atomic force microscopy.

Science.gov (United States)

Oh, Yoo Jin; Plochberger, Birgit; Rechberger, Markus; Hinterdorfer, Peter

2017-06-01

Lipopolysaccharide (LPS) on gram-negative bacterial outer membranes is the first target for antimicrobial agents, due to their spatial proximity to outer environments of microorganisms. To develop antibacterial compounds with high specificity for LPS binding, the understanding of the molecular nature and their mode of recognition is of key importance. In this study, atomic force microscopy (AFM) and single molecular force spectroscopy were used to characterize the effects of antibiotic polymyxin B (PMB) to the bacterial membrane at the nanoscale. Isolated LPS layer and the intact bacterial membrane were examined with respect to morphological changes at different concentrations of PMB. Our results revealed that 3 hours of 10 μg/mL of PMB exposure caused the highest roughness changes on intact bacterial surfaces, arising from the direct binding of PMB to LPS on the bacterial membrane. Single molecular force spectroscopy was used to probe specific interaction forces between the isolated LPS layer and PMB coupled to the AFM tip. A short range interaction regime mediated by electrostatic forces was visible. Unbinding forces between isolated LPS and PMB were about 30 pN at a retraction velocity of 500 nm/s. We further investigated the effects of the polycationic peptide PMB on bacterial outer membranes and monitored its influences on the deterioration of the bacterial membrane structure. Polymyxin B binding led to rougher appearances and wrinkles on the outer membranes surface, which may finally lead to lethal membrane damage of bacteria. Our studies indicate the potential of AFM for applications in pathogen recognition and nano-resolution approaches in microbiology. Copyright © 2017 John Wiley & Sons, Ltd.

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.

Effectiveness of Brucella abortus lipopolysaccharide as an adjuvant for tuberculin PPD.

Science.gov (United States)

Jamalan, Mostafa; Ardestani, Susan Kaboudanian; Zeinali, Majid; Mosaveri, Nader; Mohammad Taheri, Mohammad

2011-01-01

Bacterial lipopolysaccharide (LPS) has T-helper 1 (Th1) immunostimulatory activities but because of toxicity and pyrogenicity cannot be used as an adjuvant. Brucella abortus LPS has less toxicity and no pyrogenic properties in comparison to other bacterial LPS. In the current study, the immunostimulatory properties of B. abortus LPS were evaluated for its adjuvant activity. Tuberculin purified protein derivative (PPD) from Mycobacterium tuberculosis was extracted and after anion-exchange chromatography on Q-sepharose column, two fractions (17 and 23), which dominantly contained 30- and 70-kDa antigens, were collected for immunological studies. BALB/c mice were immunized with four different antigen preparations (BCG, PPD, 17th and 23rd PPD fractions) along with complete Freund's adjuvant or B. abortus LPS. The T-cell immune response of mice was assessed by measurement of Th1-type cytokine (IFN-γ) and Th2-type cytokines (IL-5 and IL-10) levels. Also, the humoral immunity was evaluated by measuring the specific IgG levels. Our results showed that immunization of mice with 17th PPD fraction along with B. abortus LPS can induce a Th1-type cytokine response characterized with a high IFN-γ/IL-5 ratio, while immunization with PPD or 23rd PPD fraction along with the same adjuvant resulted to a mixed Th1/Th2-type cytokine response. Copyright © 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Design, synthesis and evaluation of a new fluorescent probe for measuring polymyxin-lipopolysaccharide binding interactions

Science.gov (United States)

Soon, Rachel L.; Velkov, Tony; Chiu, Francis; Thompson, Philip E.; Kancharla, Rashmi; Roberts, Kade; Larson, Ian; Nation, Roger L.; Li, Jian

2011-01-01

Fluorescence assays employing semi-synthetic or commercial dansyl-polymyxin B, have been widely employed to assess the affinity of polycations, including polymyxins, for bacterial cells and lipopolysaccharide (LPS). The five primary γ-amines on diaminobutyric-acid residues of polymyxin B are potentially derivatized with dansyl-cholride. Mass spectrometric analysis of the commercial product revealed a complex mixture of di- or tetra- dansyl-substituted polymyxin B. We synthesized a mono-substituted fluorescent derivative, dansyl[Lys]1polymyxinB3. The affinity of polymyxin for purified Gram-negative LPS, and whole bacterial cells was investigated. The affinity of dansyl[Lys]1polymyxinB3 for LPS was comparable to polymyxin B and colistin, and considerably greater (kd dansyl[Lys]1polymyxinB3 to LPS, attributed to electrostatic interactions. The hydrophobic dansyl moiety imparted a greater entropic contribution to the dansyl[Lys]1polymyxinB3-LPS reaction. Molecular modeling revealed a loss of electrostatic contact within the dansyl[Lys]1polymyxinB3-LPS complex due to steric hindrance from the dansyl[Lys]1 fluorophore; this corresponded with diminished antibacterial activity (MIC ≥ 16 μg/mL). Dansyl[Lys]1polymyxinB3 may prove useful as a screening tool for drug development. PMID:21050838

Cyclical DNA Methylation and Histone Changes Are Induced by LPS to Activate COX-2 in Human Intestinal Epithelial Cells.

Directory of Open Access Journals (Sweden)

Tiziana Angrisano

Full Text Available Bacterial lipopolysaccharide (LPS induces release of inflammatory mediators both in immune and epithelial cells. We investigated whether changes of epigenetic marks, including selected histone modification and DNA methylation, may drive or accompany the activation of COX-2 gene in HT-29 human intestinal epithelial cells upon exposure to LPS. Here we describe cyclical histone acetylation (H3, methylation (H3K4, H3K9, H3K27 and DNA methylation changes occurring at COX-2 gene promoter overtime after LPS stimulation. Histone K27 methylation changes are carried out by the H3 demethylase JMJD3 and are essential for COX-2 induction by LPS. The changes of the histone code are associated with cyclical methylation signatures at the promoter and gene body of COX-2 gene.

SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

International Nuclear Information System (INIS)

Lee, Ae Sin; Jung, Yu Jin; Kim, Dal; Nguyen-Thanh, Tung; Kang, Kyung Pyo; Lee, Sik; Park, Sung Kwang; Kim, Won

2014-01-01

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

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

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 ...

Benzoxazole derivatives suppress lipopolysaccharide-induced mast cell activation.

Science.gov (United States)

Cho, Kyung-Ah; Park, Minhwa; Kim, Yu-Hee; Choo, Hea-Young Park; Lee, Kyung Ho

2018-05-01

Mast cells are central regulators of allergic inflammation that function by releasing various proallergic inflammatory mediators, including histamine, eicosanoids and proinflammatory cytokines. Occasionally, bacterial infections may initiate or worsen allergic inflammation. A number of studies have indicated that activation of lipoxygenase in mast cells positive regulates allergic inflammatory responses by generating leukotrienes and proinflammatory cytokines. In the present study, the effects of benzoxazole derivatives on the lipopolysaccharide (LPS)‑induced expression of proinflammatory cytokines, production of histamine and surface expression of co‑stimulatory molecules on bone marrow-derived mast cells (BMMCs) were studied. The benzoxazole derivatives significantly reduced the expression of interleukin (IL)‑1β, IL‑6, IL‑13, tumor necrosis factor‑α, perilipin (PLIN) 2, and PLIN3 in BMMCs treated with LPS. Furthermore, histamine production was suppressed in BMMCs treated with LPS, or treated with phorbol-12-myristate-13-acetate/ionomycin. Benzoxazole derivatives marginally affected the surface expression of cluster of differentiation (CD)80 and CD86 on BMMCs in the presence of LPS, although LPS alone did not increase the expression of those proteins. Therefore, benzoxazole derivatives inhibited the secretion of proinflammatory cytokines in mast cells and may be potential candidate anti‑allergic agents to suppress mast cell activation.

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.

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...

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.

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.

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.

Lipopolysaccharide from Crypt-Specific Core Microbiota Modulates the Colonic Epithelial Proliferation-to-Differentiation Balance

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Tomoaki Naito

2017-10-01

Full Text Available We identified a crypt-specific core microbiota (CSCM dominated by strictly aerobic, nonfermentative bacteria in murine cecal and proximal colonic (PC crypts and hypothesized that, among its possible functions, it may affect epithelial regeneration. In the present work, we isolated representative CSCM strains using selective media based upon our initial 16S rRNA-based molecular identification (i.e., Acinetobacter, Delftia, and Stenotrophomonas. Their tropism for the crypt was confirmed, and their influence on epithelial regeneration was demonstrated in vivo by monocolonization of germfree mice. We also showed that lipopolysaccharide (LPS, through its endotoxin activity, was the dominant bacterial agonist controlling proliferation. The relevant molecular mechanisms were analyzed using colonic crypt-derived organoids exposed to bacterial sonicates or highly purified LPS as agonists. We identified a Toll-like receptor 4 (TLR4-dependent program affecting crypts at different stages of epithelial differentiation. LPS played a dual role: it repressed cell proliferation through RIPK3-mediated necroptosis of stem cells and cells of the transit-amplifying compartment and concurrently enhanced cell differentiation, particularly the goblet cell lineage.

Hepatic regulation of platelet-activating factor acetylhydrolase and lecithin:cholesterol acyltransferase biliary and plasma output in rats exposed to bacterial lipopolysaccharide.

Science.gov (United States)

Svetlov, S I; Sturm, E; Olson, M S; Crawford, J M

1999-07-01

Normal rat bile contains secretory platelet-activating factor acetylhydrolase (PAF-AH), the enzyme capable of hydrolyzing the inflammatory mediator platelet-activating factor (PAF), and phospholipids containing oxidized truncated fatty acids. Because lecithin:cholesterol acyltransferase (LCAT) possesses intrinsic PAF-AH-like activity, it also may represent a potential anti-inflammatory enzyme. The behavior of PAF-AH and LCAT in hepatobiliary inflammatory responses in vivo has not been characterized. We therefore investigated the biliary and plasma secretion and pharmacological characteristics of these enzymes in rats subjected to intraportal bacterial endotoxin exposure (lipopolysaccharide [LPS], Escherichia coli, 055:B5). Portal vein LPS infusion (1 mg/kg, bolus) resulted in a maximal 4- to 5-fold increase in bile PAF-AH-specific activity with a gradual decline to baseline by 18 hours. Biliary PAF-AH hydrolyzed also the truncated sn-2-succinoyl and sn-2-glutaroyl analogs of PAF, indicating a broader activity of PAF-AH in bile toward byproducts of glycerophospholipid peroxidation. Plasma PAF-AH activity was not altered 5 hours after LPS injection compared with saline injection, but it was significantly elevated 18 hours after endotoxin exposure. The levels of LCAT in bile were low and declined to nearly undetectable values by 5 hours after cannulation in both control and LPS-exposed rats. Plasma LCAT activity was significantly increased after 5 hours and decreased 18 hours after LPS injection. In summary, hepatic exposure to endotoxin results in a rapid increase in biliary secretion of PAF-AH followed by elevation of LCAT and PAF-AH levels in plasma. We propose that biliary secretion of PAF-AH may be involved in the hepatic response to endotoxic insult by counteracting potential inflammatory damage in the biliary tree and gastrointestinal tract, whereas plasma increases in LCAT and PAF-AH may promote elimination of excess PAF and oxidized phospholipids in the

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

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.

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

Overnutrition Determines LPS Regulation of Mycotoxin Induced Neurotoxicity in Neurodegenerative Diseases

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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.

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....

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

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

Lipopolysaccharide Associates with Amyloid Plaques, Neurons and Oligodendrocytes in Alzheimer’s Disease Brain: A Review

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Xinhua Zhan

2018-02-01

Full Text Available This review proposes that lipopolysaccharide (LPS, found in the wall of all Gram-negative bacteria could play a role in causing sporadic Alzheimer’s disease (AD. This is based in part upon recent studies showing that: Gram-negative E. coli bacteria can form extracellular amyloid; bacterial-encoded 16S rRNA is present in all human brains with over 70% being Gram-negative bacteria; ultrastructural analyses have shown microbes in erythrocytes of AD patients; blood LPS levels in AD patients are 3-fold the levels in control; LPS combined with focal cerebral ischemia and hypoxia produced amyloid-like plaques and myelin injury in adult rat cortex. Moreover, Gram-negative bacterial LPS was found in aging control and AD brains, though LPS levels were much higher in AD brains. In addition, LPS co-localized with amyloid plaques, peri-vascular amyloid, neurons, and oligodendrocytes in AD brains. Based upon the postulate LPS caused oligodendrocyte injury, degraded Myelin Basic Protein (dMBP levels were found to be much higher in AD compared to control brains. Immunofluorescence showed that the dMBP co-localized with β amyloid (Aβ and LPS in amyloid plaques in AD brain, and dMBP and other myelin molecules were found in the walls of vesicles in periventricular White Matter (WM. These data led to the hypothesis that LPS acts on leukocyte and microglial TLR4-CD14/TLR2 receptors to produce NFkB mediated increases of cytokines which increase Aβ levels, damage oligodendrocytes and produce myelin injury found in AD brain. Since Aβ1–42 is also an agonist for TLR4 receptors, this could produce a vicious cycle that accounts for the relentless progression of AD. Thus, LPS, the TLR4 receptor complex, and Gram-negative bacteria might be treatment or prevention targets for sporadic AD.

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.

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

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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.

Recognition of Lipopolysaccharide and Activation of NF-κB by Cytosolic Sensor NOD1 in Teleost Fish

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Dekun Bi

2018-06-01

Full Text Available Lipopolysaccharide (LPS is the major component of the outer membrane of Gram-negative bacteria. This molecule can induce strong immune response and various biological effects. In mammals, TLR4 can recognize LPS and induce inflammatory response. However, the innate receptor in fish for recognizing LPS remains ambiguous. LPS can invade the cytoplasm via outer membrane vesicles produced by Gram-negative bacteria and could be detected by intracellular receptor caspase-11 in mammals, so, there may also exist the intracellular receptors that can recognize LPS in fish. NOD1 is a member of NOD-like receptors family and can recognize the iE-DAP in the cytoplasm in mammals. In fish, NOD1 can also respond to infection of Gram-negative bacteria and may play an important role in the identification of bacterial components. In this study, to study whether NOD1 is a recognition receptor for LPS, we detected the expression of NOD1 and several cytokines at transcript levels to determine whether LPS can induce inflammatory response in teleost fish and NOD1 can respond to LPS. Then, we perform the binding analysis between NOD1 and ultrapure LPS by using Streptavidin pulldown assay and enzyme-linked immunosorbent assay to prove that NOD1 can be combined with LPS, and using dual luciferase reporter gene assay to verify the signal pathways activated by NOD1. Next, through cell viability analysis, we proved that LPS-induced cytotoxicity can be mediated by NOD1 in fish. The results showed that NOD1 can identify LPS and activate the NF-κB signal pathway by recruiting RIPK2 and then promoting the expression of inflammatory cytokines to induce the resistance of organism against bacterial infection.

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

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

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.

Smooth and rough Proteus mirabilis lipopolysaccharides studied by total internal reflection ellipsometry

International Nuclear Information System (INIS)

Gleńska-Olender, J.; Dworecki, K.; Sęk, S.; Kwinkowski, M.; Kaca, W.

2013-01-01

Total internal reflection ellipsometry (TIRE), a label-free optical detection technique for studying interactions between biomolecules, was used to examine the adsorption of various forms of lipopolysaccharides (LPSs) isolated from Proteus mirabilis S1959, R110, and R45 strains on a gold surface. The thickness of the adsorbed layers was determined by TIRE, with the average values for S1959, R110, and R45 LPS layers being 78 ± 5, 39 ± 3, and 12 ± 2 nm, respectively. The thickness of LPS layers corresponds to the presence and length of O-specific parts in P. mirabilis LPS molecules. Atomic force microscopy was used as a complementary technique for visualizing lipopolysaccharides on the surface. Force measurements seem to confirm the data obtained from TIRE experiments. - Highlights: • Proteus mirabilis lipopolysaccharides were adsorbed on the gold surface. • Thickness of adsorbed layers was determined by total internal reflection ellipsometry. • Atomic force microscopy was used to visualize lipopolysaccharide build-up on gold surface. • Time is important in the evolution of biomolecular film thickness created on gold surface

Smooth and rough Proteus mirabilis lipopolysaccharides studied by total internal reflection ellipsometry

Energy Technology Data Exchange (ETDEWEB)

Gleńska-Olender, J., E-mail: joannaglenska@wp.pl [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland); Świętokrzyski Biobank, Regional Science and Technology Center, 26-060 Chęciny (Poland); Dworecki, K. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Sęk, S. [Department of Chemistry, University of Warsaw, 02-093 Warsaw (Poland); Kwinkowski, M.; Kaca, W. [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland)

2013-12-02

Total internal reflection ellipsometry (TIRE), a label-free optical detection technique for studying interactions between biomolecules, was used to examine the adsorption of various forms of lipopolysaccharides (LPSs) isolated from Proteus mirabilis S1959, R110, and R45 strains on a gold surface. The thickness of the adsorbed layers was determined by TIRE, with the average values for S1959, R110, and R45 LPS layers being 78 ± 5, 39 ± 3, and 12 ± 2 nm, respectively. The thickness of LPS layers corresponds to the presence and length of O-specific parts in P. mirabilis LPS molecules. Atomic force microscopy was used as a complementary technique for visualizing lipopolysaccharides on the surface. Force measurements seem to confirm the data obtained from TIRE experiments. - Highlights: • Proteus mirabilis lipopolysaccharides were adsorbed on the gold surface. • Thickness of adsorbed layers was determined by total internal reflection ellipsometry. • Atomic force microscopy was used to visualize lipopolysaccharide build-up on gold surface. • Time is important in the evolution of biomolecular film thickness created on gold surface.

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.

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

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

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.

Anti-Neuroinflammatory Effects of Houttuynia cordata Extract on LPS ...

African Journals Online (AJOL)

lipopolysaccharide (LPS)-stimulated BV-2 microglial cells, and its anti-oxidant properties. ... Keywords: Houttuynia cordata, DPPH radicals, antioxidant, neuroinflammation, BV-2 cells, iNOS, ..... extracts on anaphylactic reaction and mast cell.

Identification of lipopolysaccharide-interacting plasma membrane-type proteins in Arabidopsis thaliana.

Science.gov (United States)

Vilakazi, Cornelius S; Dubery, Ian A; Piater, Lizelle A

2017-02-01

Lipopolysaccharide (LPS) is an amphiphatic bacterial glycoconjugate found on the external membrane of Gram-negative bacteria. This endotoxin is considered as a microbe-associated molecular pattern (MAMP) molecule and has been shown to elicit defense responses in plants. Here, LPS-interacting proteins from Arabidopsis thaliana plasma membrane (PM)-type fractions were captured and identified in order to investigate those involved in LPS perception and linked to triggering of innate immune responses. A novel proteomics-based affinity-capture strategy coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the enrichment and identification of LPS-interacting proteins. As such, LPS isolated from Burkholderia cepacia (LPS B.cep. ) was immobilized on three independent and distinct affinity-based matrices to serve as bait for interacting proteins from A. thaliana leaf and callus tissue. These were resolved by 1D electrophoresis and identified by mass spectrometry. Proteins specifically bound to LPS B.cep. have been implicated in membrane structure (e.g. COBRA-like and tubulin proteins), membrane trafficking and/or transport (e.g. soluble NSF attachment protein receptor (SNARE) proteins, patellin, aquaporin, PM instrinsic proteins (PIP) and H + -ATPase), signal transduction (receptor-like kinases and calcium-dependent protein kinases) as well as defense/stress responses (e.g. hypersensitive-induced response (HIR) proteins, jacalin-like lectin domain-containing protein and myrosinase-binding proteins). The novel affinity-capture strategy for the enrichment of LPS-interacting proteins proved to be effective, especially in the binding of proteins involved in plant defense responses, and can thus be used to elucidate LPS-mediated molecular recognition and disease mechanism(s). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period.

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McDonald, Fiona B; Chandrasekharan, Kumaran; Wilson, Richard J A; Hasan, Shabih U

2016-02-01

Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on

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

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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.

Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus)

DEFF Research Database (Denmark)

Lazado, Carlo Cabacang; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

2016-01-01

The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L...... experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS...... significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15...

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

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 ...

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.

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

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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

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.

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

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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.

Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

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Donovan, Chantal; Royce, Simon G; Vlahos, Ross; Bourke, Jane E

2015-01-01

The bacterial endotoxin, lipopolysaccharide (LPS) has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml) for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

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Chantal Donovan

Full Text Available The bacterial endotoxin, lipopolysaccharide (LPS has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

Bacterial and fungal markers in tobacco smoke

International Nuclear Information System (INIS)

Szponar, B.; Pehrson, C.; Larsson, L.

2012-01-01

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 3 (N = 5) and 0.0007/m 3 (N = 6) in the smoking vs. non-smoking rooms (p = 0.0559) of the studied private houses, and 0.0231 nmol/m 3 (N = 5) vs. 0.0006 nmol/m 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: ► Air concentration of bacterial and fungal markers is significantly higher in rooms with ongoing smoking than without smoking. ► Bacterial LPS correlates with fungal marker in rooms with ongoing smoking but not without smoking. ► LPS from mainstream smoke contains 3-hydroxy 14:0 and 12:0 fatty acids in similar proportion as

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

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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.

Lipopolysaccharide (LPS) stimulates adipokine and socs3 gene expression in mouse brain and pituitary gland in vivo, and in N-1 hypothalamic neurons in vitro.

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Brown, Russell; Imran, Syed A; Wilkinson, Michael

2009-04-30

Adipokines that modulate metabolic and inflammatory responses, such as resistin (rstn) and fasting-induced adipose factor (fiaf), are also expressed in mouse brain and pituitary gland. Since lipopolysaccharide (LPS)-induced endotoxinemia provokes an anorectic response via a hypothalamic-dependent mechanism we hypothesized that LPS would also modify hypothalamic adipokine expression. Challenging male CD-1 mice with LPS (5 mg/kg; s.c.) significantly reduced bodyweight (24 h) and realtime RT-PCR revealed time- and tissue-dependent increases in rstn, fiaf and suppressor of cytokine signaling-3 (socs-3) mRNA in hypothalamic, pituitary, cortical and adipose tissues. Gene expression was rapidly increased (3-6 h) in the hypothalamus and pituitary, but returned to normal within 24 h. In contrast, with the exception of rstn in fat, the expression of target genes remained elevated in cortex and visceral fat at 24 h post-injection. In order to more specifically examine the hypothalamic response to LPS we investigated its effects directly on N-1 hypothalamic neurons in vitro. LPS (25 microg/mL; 3 h) had no effect on rstn mRNA, but significantly stimulated fiaf and socs-3 expression. Although various toll-like receptor 4 (TLR4) antagonists (parthenolide, PD098059, and SB202190) did not prevent the LPS-induced increases in fiaf and socs-3, they did partially attenuate its stimulatory effects. We conclude that LPS treatment increases the expression of central, and possibly neuronal, adipokine genes which may influence local tissue repair and function, but could also have downstream consequences on the hypothalamic control of appetite and energy metabolism following an inflammatory insult.

CD36 Differently Regulates Macrophage Responses to Smooth and Rough Lipopolysaccharide.

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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

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.

Bacterial contamination hypothesis: a new concept in endometriosis.

Science.gov (United States)

Khan, Khaleque N; Fujishita, Akira; Hiraki, Koichi; Kitajima, Michio; Nakashima, Masahiro; Fushiki, Shinji; Kitawaki, Jo

2018-04-01

Endometriosis is a multifactorial disease that mainly affects women of reproductive age. The exact pathogenesis of this disease is still debatable. The role of bacterial endotoxin (lipopolysaccharide, LPS) and Toll-like receptor 4 (TLR4) in endometriosis were investigated and the possible source of endotoxin in the pelvic environment was examined. The limulus amoebocyte lysate test was used to measure the endotoxin levels in the menstrual fluid and peritoneal fluid and their potential role in the growth of endometriosis was investigated. Menstrual blood and endometrial samples were cultured for the presence of microbes. The effect of gonadotrophin-releasing hormone agonist (GnRHa) treatment on intrauterine microbial colonization (IUMC) and the occurrence of endometritis was investigated. Lipopolysaccharide regulates the pro-inflammatory response in the pelvis and growth of endometriosis via the LPS/TLR4 cascade. The menstrual blood was highly contaminated with Escherichea coli and the endometrial samples were colonized with other microbes. A cross-talk between inflammation and ovarian steroids or the stress reaction also was observed in the pelvis. Treatment with GnRHa further worsens intrauterine microbial colonization, with the consequent occurrence of endometritis in women with endometriosis. For the first time, a new concept called the "bacterial contamination hypothesis" is proposed in endometriosis. This study's findings of IUMC in women with endometriosis could hold new therapeutic potential in addition to the conventional estrogen-suppressing agent.

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

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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

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...

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.

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...

Variability in In Vitro Macrophage Activation by Commercially Diverse Bulk Echinacea Plant Material is Predominantly Due to Bacterial Lipoproteins and Lipopolysaccharides

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We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overa...

Lipopolysaccharide aggravated DOI-induced Tourette syndrome: elaboration for recurrence of Tourette syndrome.

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Hongyan, Long; Zhenyang, Si; Chunyan, Wang; Qingqing, Pan

2017-12-01

Tourette syndrome (TS) is a neurological disorder characterized by highest familial recurrence rate among neuropsychiatric diseases with complicated inheritance. Recurrence of Tourette syndrome was frequently observed in clinical. Unexpectedly, the mechanism of recurrence of Tourette syndrome was failure to elucidate. Here, we first shown that lipopolysaccharide(LPS) may played an important role in the recurrence of Tourette syndrome. The TS model in rats was induced by DOI (the selective 5-HT2A/2C agonist 1-(2, 5-dimethoxy-4-iodophenyl) -2- aminopropane). The rats were randomly divided into 4 groups:(1)Control;(2) Control + LPS; (2)TS; (3)TS + LPS. The results demonstrated that the LPS treatment significantly increased stereotypic score and autonomic activity. LPS treatment also significantly increased inflammatory cytokines such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum and striatum. Also, highly expressed TLR4, MyD88, P-NF-κBp65, P-IκBα in TS rats were increased respectively by LPS treatment as indicted in western blot analysis and immunohistochemistry analysis. Thus, it was supposed that lipopolysaccharide(LPS) may played an important role in the recurrence of Tourette syndrome and its mechanism was related to TLR/NF-κB pathway.

Lipopolysaccharides of Rhizobium etli strain G12 act in potato roots as an inducing agent of systemic resistance to infection by the cyst nematode Globodera pallida.

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Reitz, M; Rudolph, K; Schröder, I; Hoffmann-Hergarten, S; Hallmann, J; Sikora, R A

2000-08-01

Recent studies have shown that living and heat-killed cells of the rhizobacterium Rhizobium etli strain G12 induce in potato roots systemic resistance to infection by the potato cyst nematode Globodera pallida. To better understand the mechanisms of induced resistance, we focused on identifying the inducing agent. Since heat-stable bacterial surface carbohydrates such as exopolysaccharides (EPS) and lipopolysaccharides (LPS) are essential for recognition in the symbiotic interaction between Rhizobium and legumes, their role in the R. etli-potato interaction was studied. EPS and LPS were extracted from bacterial cultures, applied to potato roots, and tested for activity as an inducer of plant resistance to the plant-parasitic nematode. Whereas EPS did not affect G. pallida infection, LPS reduced nematode infection significantly in concentrations as low as 1 and 0.1 mg ml(-1). Split-root experiments, guaranteeing a spatial separation of inducing agent and challenging pathogen, showed that soil treatments of one half of the root system with LPS resulted in a highly significant (up to 37%) systemic induced reduction of G. pallida infection of potato roots in the other half. The results clearly showed that LPS of R. etli G12 act as the inducing agent of systemic resistance in potato roots.

Effects of lidocaine on lipopolysaccharide-induced synovitis in horses

OpenAIRE

Campebell,R.C.; Peiró,J.R.; Valadão,C.A.A.; Santana,A.E.; Cunha,F.Q.

2004-01-01

Lidocaine (100mg 2%) injected into the carpal joint was used to evaluate the inflammatory response induced by injection (1.5ng) of intra-articular E. coli lipopolysaccharide (LPS) endotoxin. Seventeen male Mangalarga horses aged two to three years were divided into three groups and in all animals was injected 0.9% saline (SAL) in the left carpus (LC), and in the right carpus (RC) one of the following combinations were injected: group A (n=6) LPS plus SAL; group B (n=6) LPS plus lidocaine; gro...

Lipopolysaccharide contamination of beta-lactoglobulin affects the immune response against intraperitoneally and orally administered antigen

DEFF Research Database (Denmark)

Pedersen, Susanne Brix; Kjær, T.M.R.; Barkholt, Vibeke

2004-01-01

Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like co......-LG was contaminated with LPS. Conclusions: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein.......Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like cow......'s milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. Methods: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein beta-lactoglobulin (beta-LG) on antigen-specific immune responses. IgG1/IgG2a production upon...

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.

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

Directory of Open Access Journals (Sweden)

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.

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

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Gardères, Johan; Bedoux, Gilles; Koutsouveli, Vasiliki; Crequer, Sterenn; Desriac, Florie; Le Pennec, Gaël

2015-01-01

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. PMID:26262625

The role of lipopolysaccharide in infectious bone resorption of periapical lesion.

Science.gov (United States)

Hong, Chi-Yuan; Lin, Sze-Kwan; Kok, Sang-Heng; Cheng, Shih-Jung; Lee, Ming-Shu; Wang, Tong-Mei; Chen, Chuan-Shuo; Lin, Li-Deh; Wang, Juo-Song

2004-03-01

The role of lipopolysaccharide (LPS) in periapical lesion-induced bone resorption was investigated. Polymyxin B (PMB), a specific inhibitor of LPS, was evaluated to treat the apical lesion. Lipopolysaccharide isolated from two common endodontic pathogens, Fusobacterium nucleatum and Porphyromonas endodontalis, stimulated mouse macrophage (J774) to release interleukin-1alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) in a time-dependent manner. Combination of LPS further enhanced the stimulation. PMB inhibited these effects significantly. LPS also stimulated matrix metalloproteinase-1 (MMP-1) gene expression in J774, whereas anti-IL-1 alpha and anti-TNF-alpha antibodies, as well as PMB, diminished this effect. A disease model of periapical lesion was established in Wistar rat. Administration of PMB reduced the extent of lesion-associated bone resorption by 76% to approximately 80%, and simultaneously reduced the numbers of MMP-1-producing macrophages. It is suggested that LPS released from the infected root canal triggers the synthesis of IL-1 alpha and TNF-alpha from macrophages. These pro-inflammatory cytokines up-regulate the production of MMP-1 by macrophages to promote periapical bone resorption.

TLR4-NOX4-AP-1 signaling mediates lipopolysaccharide-induced CXCR6 expression in human aortic smooth muscle cells

International Nuclear Information System (INIS)

Patel, Devang N.; Bailey, Steven R.; Gresham, John K.; Schuchman, David B.; Shelhamer, James H.; Goldstein, Barry J.; Foxwell, Brian M.; Stemerman, Michael B.; Maranchie, Jodi K.; Valente, Anthony J.; Mummidi, Srinivas; Chandrasekar, Bysani

2006-01-01

CXCL16 is a transmembrane non-ELR CXC chemokine that signals via CXCR6 to induce aortic smooth muscle cell (ASMC) proliferation. While bacterial lipopolysaccharide (LPS) has been shown to stimulate CXCL16 expression in SMC, its effects on CXCR6 are not known. Here, we demonstrate that LPS upregulates CXCR6 mRNA, protein, and surface expression in human ASMC. Inhibition of TLR4 with neutralizing antibodies or specific siRNA interference blocked LPS-mediated CXCR6 expression. LPS stimulated both AP-1 (c-Fos, c-Jun) and NF-κB (p50 and p65) activation, but only inhibition of AP-1 attenuated LPS-induced CXCR6 expression. Using dominant negative expression vectors and siRNA interference, we demonstrate that LPS induces AP-1 activation via MyD88, TRAF6, ERK1/2, and JNK signaling pathways. Furthermore, the flavoprotein inhibitor diphenyleniodonium chloride significantly attenuated LPS-mediated AP-1-dependent CXCR6 expression, as did inhibition of NOX4 NADPH oxidase by siRNA. Finally, CXCR6 knockdown inhibited CXCL16-induced ASMC proliferation. These results demonstrate that LPS-TLR4-NOX4-AP-1 signaling can induce CXCR6 expression in ASMC, and suggest that the CXCL16-CXCR6 axis may be an important proinflammatory pathway in the pathogenesis of atherosclerosis

Metabonomic evaluation of idiosyncrasy-like liver injury in rats cotreated with ranitidine and lipopolysaccharide

International Nuclear Information System (INIS)

Maddox, Jane F.; Luyendyk, James P.; Cosma, Gregory N.; Breau, Alan P.; Bible, Roy H.; Harrigan, George G.; Goodacre, Royston; Ganey, Patricia E.; Cantor, Glenn H.; Cockerell, Gary L.; Roth, Robert A.

2006-01-01

Idiosyncratic liver injury occurs in a small fraction of people on certain drug regimens. The cause of idiosyncratic hepatotoxicity is not known; however, it has been proposed that environmental factors such as concurrent inflammation initiated by bacterial lipopolysaccharide (LPS) increase an individual's susceptibility to drug toxicity. Ranitidine (RAN), a histamine-2 receptor antagonist, causes idiosyncratic liver injury in humans. In a previous report, idiosyncrasy-like liver toxicity was created in rats by cotreating them with LPS and RAN. In the present study, the ability of metabonomic techniques to distinguish animals cotreated with LPS and RAN from those treated with each agent individually was investigated. Rats were treated with LPS or its vehicle and with RAN or its vehicle, and urine was collected for nuclear magnetic resonance (NMR)- and mass spectroscopy-based metabonomic analyses. Blood and liver samples were also collected to compare metabonomic results with clinical chemistry and histopathology. NMR metabonomic analysis indicated changes in the pattern of metabolites consistent with liver damage that occurred only in the LPS/RAN cotreated group. Principal component analysis of urine spectra by either NMR or mass spectroscopy produced a clear separation of the rats treated with LPS/RAN from the other three groups. Clinical chemistry (serum alanine aminotransferase and aspartate aminotransferase activities) and histopathology corroborated these results. These findings support the potential use of a noninvasive metabonomic approach to identify drug candidates with potential to cause idiosyncratic liver toxicity with inflammagen coexposure

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

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

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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

A midgut lysate of the Riptortus pedestris has antibacterial activity against LPS O-antigen-deficient Burkholderia mutants.

Science.gov (United States)

Jang, Ho Am; Seo, Eun Sil; Seong, Min Young; Lee, Bok Luel

2017-02-01

Riptortus pedestris, a common pest in soybean fields, harbors a symbiont Burkholderia in a specialized posterior midgut region of insects. Every generation of second nymphs acquires new Burkholderia cells from the environment. We compared in vitro cultured Burkholderia with newly in vivo colonized Burkholderia in the host midgut using biochemical approaches. The bacterial cell envelope of in vitro cultured and in vivo Burkholderia differed in structure, as in vivo bacteria lacked lipopolysaccharide (LPS) O-antigen. The LPS O-antigen deficient bacteria had a reduced colonization rate in the host midgut compared with that of the wild-type Burkholderia. To determine why LPS O-antigen-deficient bacteria are less able to colonize the host midgut, we examined in vitro survival rates of three LPS O-antigen-deficient Burkholderia mutants and lysates of five different midgut regions. The LPS O-antigen-deficient mutants were highly susceptible when cultured with the lysate of a specific first midgut region (M1), indicating that the M1 lysate contains unidentified substance(s) capable of killing LPS O-antigen-deficient mutants. We identified a 17 kDa protein from the M1 lysate, which was enriched in the active fractions. The N-terminal sequence of the protein was determined to be a soybean Kunitz-type trypsin inhibitor. These data suggest that the 17 kDa protein, which was originated from a main soybean source of the R. pedestris host, has antibacterial activity against the LPS O-antigen deficient (rough-type) Burkholderia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preconditioning with Lipopolysaccharide or Lipoteichoic Acid Protects against Staphylococcus aureus Mammary Infection in Mice

Directory of Open Access Journals (Sweden)

Koen Breyne

2017-07-01

Full Text Available Staphylococcus aureus is one of the most causative agents of mastitis and is associated with chronic udder infections. The persistency of the pathogen is believed to be the result of an insufficient triggering of local inflammatory signaling. In this study, the preclinical mastitis model was used, aiming to evaluate if lipopolysaccharide (LPS or lipoteichoic acid (LTA preconditioning could aid the host in more effectively clearing or at least limiting a subsequent S. aureus infection. A prototypic Gram-negative virulence factor, i.e., LPS and Gram-positive virulence factor, i.e., LTA were screened whether they were able to boost the local immune compartment. Compared to S. aureus-induced inflammation, both toxins had a remarkable high potency to efficiently induce two novel selected innate immunity biomarkers i.e., lipocalin 2 (LCN2 and chitinase 3-like 1 (CHI3L1. When combining mammary inoculation of LPS or LTA prior to a local S. aureus infection, we were able to modulate the innate immune response, reduce local bacterial loads, and induce either LCN2 or CHI3L1 at 24 h post-infection. Clodronate depletion of mammary macrophages also identified that macrophages contribute only to a limited extend to the LPS/LTA-induced immunomodulation upon S. aureus infection. Based on histological neutrophil influx evaluation, concomitant local cytokine profiles and LCN2/CHI3L1 patterns, the macrophage-independent signaling plays a major role in the LPS- or LTA-pretreated S. aureus-infected mouse mammary gland. Our results highlight the importance of a vigilant microenvironment during the innate immune response of the mammary gland and offer novel insights for new approaches concerning effective immunomodulation against a local bacterial infection.

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.

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.

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.

Importance of lipopolysaccharide aggregate disruption for the anti-endotoxic effects of heparin cofactor II peptides.

Science.gov (United States)

Singh, Shalini; Papareddy, Praveen; Kalle, Martina; Schmidtchen, Artur; Malmsten, Martin

2013-11-01

Lipid membrane and lipopolysaccharide (LPS) interactions were investigated for a series of amphiphilic and cationic peptides derived from human heparin cofactor II (HCII), using dual polarization interferometry, ellipsometry, circular dichroism (CD), cryoTEM, and z-potential measurements. Antimicrobial effects of these peptides were compared to their ability to disorder bacterial lipid membranes, while their capacity to block endotoxic effects of LPS was correlated to the binding of these peptides to LPS and its lipid A moiety, and to charge, secondary structure, and morphology of peptide/LPS complexes. While the peptide KYE28 (KYEITTIHNLFRKLTHRLFRRNFGYTLR) displayed potent antimicrobial and anti-endotoxic effects, its truncated variants KYE21 (KYEITTIHNLFRKLTHRLFRR) and NLF20 (NLFRKLTHRLFRRNFGYTLR) provide some clues on structure-activity relations, since KYE21 retains both the antimicrobial and anti-endotoxic effects of KYE28 (although both attenuated), while NLF20 retains the antimicrobial but only a fraction of the anti-endotoxic effect, hence locating the anti-endotoxic effects of KYE28 to its N-terminus. The antimicrobial effect, on the other hand, is primarily located at the C-terminus of KYE28. While displaying quite different endotoxic effects, these peptides bind to a similar extent to both LPS and lipid A, and also induce comparable LPS scavenging on model eukaryotic membranes. In contrast, fragmentation and densification of LPS aggregates, in turn dependent on the secondary structure in the peptide/LPS aggregates, correlate to the anti-endotoxic effect of these peptides, thus identifying peptide-induced packing transitions in LPS aggregates as key for anti-endotoxic functionality. This aspect therefore needs to be taken into account in the development of novel anti-endotoxic peptide therapeutics. Copyright © 2013. Published by Elsevier B.V.

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

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

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Wang, Jun; Si, Yanfang; Wu, Chen; Sun, Lu; Ma, Yudong; Ge, Aili; Li, Baomin

2012-10-17

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. 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). 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 infection contributes to the pathological process of

Thalidomide protects mice against LPS-induced shock

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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

Effect of ionizing radiation on macrophage stimulating property of Vibrio parahaemolyticus lipopolysaccharide

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Bandekar, J R; Nene, S P; Nerkar, D P

1988-09-01

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.

O antigen modulates insect vector acquisition of the bacterial plant pathogen Xylella fastidiosa.

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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.

Lung cell reactions in guinea pigs exposed to tobacco smoke and silica dust or bacterial lipopolysaccharides

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Sjoestrand, M; Rylander, R

1984-02-01

In order to investigate the possibility of the synergistic effects of tobacco smoke and/or silica dust (SiO2) or bacterial endotoxins (LPS), guinea pigs were exposed to combinations of these agents. A 15-day exposure to SiO2 alone caused a decrease in intracellular lysosomal enzymes of alveolar macrophages (AM) and an increase of lysosomal enzymes detected in lung lavage fluid which was present 16 weeks after exposure. The effect was the same in animals which received SiO2 in combination with tobacco smoke. Exposure to LPS caused an increase in the number of neutrophils recovered in lavage fluid. The increase in neutrophils was less in animals previously exposed to tobacco smoke alone or in combination with LPS. Acute exposure to LPS also caused an increase in lactate dehydrogenase, N-acetyl-beta-D-glucosaminidase and acid phosphatase activity detectable in lung lavage fluid. The increase was less pronounced in animals previously exposed to smoke. Cathepsin D was increased in AM after tobacco smoke exposure alone and was decreased to below control values of the animals which received an acute LPS exposure.

Mechanisms of the priming effect of low doses of lipopoly-saccharides on leukocyte-dependent platelet aggregation in whole blood.

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Montrucchio, Giuseppe; Bosco, Ornella; Del Sorbo, Lorenzo; Fascio Pecetto, Paolo; Lupia, Enrico; Goffi, Alberto; Omedè, Paola; Emanuelli, Giorgio; Camussi, Giovanni

2003-11-01

Several studies focused on the ability of bacterial lipopolysac-charides (LPS) in triggering platelet and/or leukocyte activation. The aim of this study was to investigate the molecular mechanisms involved in the aggregation of platelets and in their interaction with leukocytes in whole blood after stimulation with low doses of LPS. LPS did not directly induce platelet aggregation in whole blood, but they primed the aggregation of platelets induced by epinephrine, adenosine diphosphate and arachidonic acid. As shown by cytofluorimetry, platelets neither bind FITC-LPS, nor express the LPS-receptors CD14 and toll-like receptor 4 (TLR4). On the contrary, LPS primed monocytes and to a lesser extent polymorphonuclear neutrophils to adhere to platelets. Both platelet-leukocyte interaction and platelet aggregation in whole blood were inhibited by blockade of CD14 and TLR4. Moreover, the interaction between platelets and leukocytes was inhibited by P-selectin, and by blockade of PAF and reactive oxygen species, suggesting a role of P-selectin and of leukocyte-derived mediators. In conclusion, these results elucidate the mechanisms leading to platelet activation and interaction with leukocytes triggered by LPS. They suggest that the activation of platelets by LPS is mainly dependent on leukocytes and especially monocytes as a result of CD14 and TLR4 engagement. Moreover, we found that leukocyte-platelet interaction was triggered by the synthesis of PAF and the generation of oxygen radicals that induced upregulation of surface expression of P-selectin.

Coxiella burnetii Lipopolysaccharide: What Do We Know?

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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.

Coxiella burnetii Lipopolysaccharide: What Do We Know?

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Abnave, Prasad; Muracciole, Xavier; Ghigo, Eric

2017-01-01

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. PMID:29168790

Modulation of lipopolysaccharide-induced chorioamnionitis in fetal sheep by maternal betamethasone.

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Wolfe, Katherine B; Snyder, Candice C; Gisslen, Tate; Kemp, Matthew W; Newnham, John P; Kramer, Boris W; Jobe, Alan H; Kallapur, Suhas

2013-12-01

We tested the hypothesis that the order of exposure to maternal betamethasone and intra-amniotic (IA) lipopolysaccharide (LPS) will differentially modulate inflammation in the chorioamnion. Time-mated Merino ewes with singleton fetuses received saline alone, IA LPS alone, maternal betamethasone before LPS, or betamethasone after LPS. We assessed inflammatory markers in the chorioamnion and the amniotic fluid. Inflammatory cell infiltration, expression of myeloperoxidase, serum amyloid A3 (acute phase reactant) in the chorioamnion, and levels of interleukin (IL)-8 in the amniotic fluid increased 7 days after LPS exposure. Betamethasone prior to LPS decreased infiltration of the inflammatory cells, CD3+ T cells, and decreased the levels of IL-1β and IL-8 in the amniotic fluid. Betamethasone 7 days prior to LPS exposure suppressed LPS-induced inflammation. The markers of inflammation largely had returned to the baseline 14 days after LPS exposure.

Single-cell and population NF-κB dynamic responses depend on lipopolysaccharide preparation.

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Miriam V Gutschow

Full Text Available Lipopolysaccharide (LPS, found in the outer membrane of gram-negative bacteria, elicits a strong response from the transcription factor family Nuclear factor (NF-κB via Toll-like receptor (TLR 4. The cellular response to lipopolysaccharide varies depending on the source and preparation of the ligand, however. Our goal was to compare single-cell NF-κB dynamics across multiple sources and concentrations of LPS.Using live-cell fluorescence microscopy, we determined the NF-κB activation dynamics of hundreds of single cells expressing a p65-dsRed fusion protein. We used computational image analysis to measure the nuclear localization of the fusion protein in the cells over time. The concentration range spanned up to nine orders of magnitude for three E. coli LPS preparations. We find that the LPS preparations induce markedly different responses, even accounting for potency differences. We also find that the ability of soluble TNF receptor to affect NF-κB dynamics varies strikingly across the three preparations.Our work strongly suggests that the cellular response to LPS is highly sensitive to the source and preparation of the ligand. We therefore caution that conclusions drawn from experiments using one preparation may not be applicable to LPS in general.

Synthetic LPS-Binding Polymer Nanoparticles

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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

Fetal calf serum heat inactivation and lipopolysaccharide contamination influence the human T lymphoblast proteome and phosphoproteome

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Rahman Hazir

2011-11-01

Full Text Available Abstract Background The effects of fetal calf serum (FCS heat inactivation and bacterial lipopolysaccharide (LPS contamination on cell physiology have been studied, but their effect on the proteome of cultured cells has yet to be described. This study was undertaken to investigate the effects of heat inactivation of FCS and LPS contamination on the human T lymphoblast proteome. Human T lymphoblastic leukaemia (CCRF-CEM cells were grown in FCS, either non-heated, or heat inactivated, having low ( Results A total of four proteins (EIF3M, PRS7, PSB4, and SNAPA were up-regulated when CCRF-CEM cells were grown in media supplemented with heat inactivated FCS (HE as compared to cells grown in media with non-heated FCS (NHE. Six proteins (TCPD, ACTA, NACA, TCTP, ACTB, and ICLN displayed a differential phosphorylation pattern between the NHE and HE groups. Compared to the low concentration LPS group, regular levels of LPS resulted in the up-regulation of three proteins (SYBF, QCR1, and SUCB1. Conclusion The present study provides new information regarding the effect of FCS heat inactivation and change in FCS-LPS concentration on cellular protein expression, and post-translational modification in human T lymphoblasts. Both heat inactivation and LPS contamination of FCS were shown to modulate the expression and phosphorylation of proteins involved in basic cellular functions, such as protein synthesis, cytoskeleton stability, oxidative stress regulation and apoptosis. Hence, the study emphasizes the need to consider both heat inactivation and LPS contamination of FCS as factors that can influence the T lymphoblast proteome.

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

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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

Gomisin N ameliorates lipopolysaccharide-induced depressive-like behaviors by attenuating inflammation in the hypothalamic paraventricular nucleus and central nucleus of the amygdala in mice

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Ryota Araki

2016-10-01

Full Text Available Emotional impairments such as depressive symptoms often develop in patients with sustained and systemic immune activation. The objective of this study is to investigate the effect of gomisin N, a dibenzocyclooctadiene lignan isolated from the dried fruits of Schisandra chinensis (Turcz. Baill., which exhibited inhibitory effects of the bacterial endotoxin lipopolysaccharide (LPS-induced NO production in a screening assay, on inflammation-induced depressive symptoms. We examined the effects of gomisin N on inflammation induced by LPS in murine microglial BV-2 cells and on LPS-induced behavioral changes in mice. Gomisin N inhibited LPS-induced expression of mRNAs for inflammation-related genes (inducible nitric oxide synthase (iNOS, cyclooxygenase (COX-2, interleukin (IL-1β, IL-6 and tumor necrosis factor (TNF-α in BV-2 cells. Administration of gomisin N attenuated LPS-induced expression of mRNAs for inflammation-related genes, increases in the number of c-Fos immunopositive cells in the hypothalamus and amygdala, depressive-like behavior in the forced swim test and exploratory behavior deficits 24 h after LPS administration in mice. These results suggest that gomisin N might ameliorate LPS-induced depressive-like behaviors through inhibition of inflammatory responses and neural activation in the hypothalamus and amygdala.

Anti-inflammation effect of methyl salicylate 2-O-β-D-lactoside on adjuvant induced-arthritis rats and lipopolysaccharide (LPS)-treated murine macrophages RAW264.7 cells.

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Zhang, Xue; Sun, Jialin; Xin, Wenyu; Li, Yongjie; Ni, Lin; Ma, Xiaowei; Zhang, Dan; Zhang, Dongming; Zhang, Tiantai; Du, Guanhua

2015-03-01

Methyl salicylate 2-O-β-D-lactoside (MSL) is a derivative of natural salicylate isolated from Gaultheria yunnanensis (Franch.) Rehder, which is widely used for treating rheumatoid arthritis (RA), swelling and pain. The aim of the present study was to investigate the effect of MSL on the progression of adjuvant-induced arthritis (AIA) in rat in vivo and explore the anti-inflammatory effects and mechanism of MSL in lipopolysaccharide (LPS)-treated murine macrophages RAW264.7 cells in vitro. Our results showed that MSL significantly inhibited the arthritis progression in AIA rats, decreasing the right hind paw swelling and ankle diameter, attenuating histopathological changes and suppressing the plasma levels of TNF-α and IL-1β in AIA rats. Besides, MSL had potent anti-inflammatory effects on the LPS-activated RAW264.7. MSL dose-dependently inhibited the activity of COX-1, and COX-2. Moreover, MSL prominently inhibited LPS-induced activation of MAPK in RAW264.7 cells by blocking phosphorylation of p38 and ERK. Our study suggests that MSL may be effective in the treatment of inflammatory diseases by inhibiting the pro-inflammatory cytokine production and regulating the MAPK signal pathway. Copyright © 2015. Published by Elsevier B.V.

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....

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

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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

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

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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

RNA interference prevents lipopolysaccharide-induced preprotachykinin gene expression

International Nuclear Information System (INIS)

Lai, Y.-L.; Yu, S.C.; Chen, M.-J.

2003-01-01

We showed previously that lipopolysaccharide (LPS) induces noncholinergic airway hyperreactivity to capsaicin via an upregulation of tachykinin synthesis. This study was designed to test whether double-stranded preprotachykinin (ds PPT) RNA, RNA interference (RNAi), prevents the LPS-induced alterations. First, cultured primary nodose ganglial cells of newborn Brown-Norway rats were divided into four groups: control; LPS; LPS+RNAi; and LPS+RNAi+liposome. Second, young Brown-Norway rats for the in vivo study were divided into three groups (control; LPS; and LPS+RNAi), and ds PPT RNA was microinjected bilaterally into the nodose ganglia in the LPS+RNAi group. Then, ganglial cells were collected from the culture whereas the nodose ganglia and lungs were sampled from the animals, and PPT mRNA and substance P (SP) levels were analyzed. Also, airway reactivity to capsaicin was performed in vivo. LPS induced significant increases in PPT mRNA and SP levels in vitro and in vivo and an increase in airway reactivity to capsaicin in vivo. However, ds PPT RNA, but not scrambled RNA, prevented all LPS-induced alterations. The effect of ds PPT RNA was not enhanced by liposome in vitro. Therefore, we demonstrated that the local application of RNAi prevents effectively the activation of the noncholinergic system modulating the lungs/airways

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

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Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-09-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p < 0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness.

Anti-lipopolysaccharide toxin therapy for whole body X-irradiation overdose

International Nuclear Information System (INIS)

Gaffin, S.L.; Wells, M.; Jordan, J.P.

1985-01-01

Death in humans from ionising radiation overexposure in the 3-8 Gy (300-800 rad) range is in part due to the toxaemia caused by the entry of gram-negative bacteria and/or their lipopolysaccharide toxin (LPS) into the blood circulation through the walls of partially denuded gut. Anti-LPS hyperimmune equine plasma was evaluated for its ability to lower irradiation-induced lethality. Mice were irradiated with 6.3 Gy (630 rad) and six days later received equine Anti-LPS hyperimmune plasma, control plasma or saline. Mortalities in the three groups were 58%, 92% and 79% (p<0.01) respectively. Thus Anti-LPS may prove useful as an adjunct to conventional therapy in treating radiation sickness. (author)

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

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...

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

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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.

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)

Revisiting the systemic lipopolysaccharide mediated neuroinflammation: Appraising the effect of l-cysteine mediated hydrogen sulphide on it

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Abdulaziz S. Al-Saeedan

2018-05-01

Full Text Available The present research was ventured to examine the effect of l-cysteine on neuro-inflammation persuaded by peripheral lipopolysaccharides (LPS, 125 μg/kg, i.p. administration. No behavioral, biochemical, and inflammatory abnormality was perceived in the brain tissues of experimental animals after LPS administration. l-cysteine precipitated marginal symptoms of toxicity in the brain tissue. Similar pattern of wholesome effect of LPS were perceived when evaluated through the brain tissue fatty acid profile, histopathologically and NF-ĸBP65 protein expression. LPS was unsuccessful to alter the levels of hydrogen sulphide (H2S, cyclooxygenase (COX and lipoxygenase (LOX enzyme in brain tissue. LPS afforded significant peripheral toxicity, when figured out through inflammatory markers (COX, LOX, gaseous signaling molecules nitric oxide (NO, H2S, liver toxicity (SGOT, SGPT, and inflammatory transcription factor (NF-ĸBP65 and l-cysteine also provided a momentous protection against the same as well. The study inculcated two major finding, firstly LPS (i.p. cannot impart inflammatory changes to brain and secondly, l-cysteine can afford peripheral protection against deleterious effect of LPS (i.p. Keywords: Hydrogen sulphide, l-cysteine, Inflammation, Lipopolysaccharide, Neuroinflammation

Visualization and analysis of lipopolysaccharide distribution in binary phospholipid bilayers

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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.

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

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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

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.

Endogenous brain IL-1 mediates LPS-induced anorexia and hypothalamic cytokine expression.

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Layé, S; Gheusi, G; Cremona, S; Combe, C; Kelley, K; Dantzer, R; Parnet, P

2000-07-01

The present study was designed to determine the role of endogenous brain interleukin (IL)-1 in the anorexic response to lipopolysaccharide (LPS). Intraperitoneal administration of LPS (5-10 microgram/mouse) induced a dramatic, but transient, decrease in food intake, associated with an enhanced expression of proinflammatory cytokine mRNA (IL-1beta, IL-6, and tumor necrosis factor-alpha) in the hypothalamus. This dose of LPS also increased plasma levels of IL-1beta. Intracerebroventricular pretreatment with IL-1 receptor antagonist (4 microgram/mouse) attenuated LPS-induced depression of food intake and totally blocked the LPS-induced enhanced expression of proinflammatory cytokine mRNA measured in the hypothalamus 1 h after treatment. In contrast, LPS-induced increases in plasma levels of IL-1beta were not altered. These findings indicate that endogenous brain IL-1 plays a pivotal role in the development of the hypothalamic cytokine response to a systemic inflammatory stimulus.

Calcium hydroxide suppresses Porphyromonas endodontalis lipopolysaccharide-induced bone destruction.

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Guo, J; Yang, D; Okamura, H; Teramachi, J; Ochiai, K; Qiu, L; Haneji, T

2014-05-01

Porphyromonas endodontalis and its main virulence factor, lipopolysaccharide (LPS), are associated with the development of periapical diseases and alveolar bone loss. Calcium hydroxide is commonly used for endodontic therapy. However, the effects of calcium hydroxide on the virulence of P. endodontalis LPS and the mechanism of P. endodontalis LPS-induced bone destruction are not clear. Calcium hydroxide rescued the P. endodontalis LPS-suppressed viability of MC3T3-E1 cells and activity of nuclear factor-κB (NF-κB) in these cells, resulting in the reduced expression of interleukin-6 and tumor necrosis factor-α. In addition, calcium hydroxide inhibited P. endodontalis LPS-induced osteoclastogenesis by decreasing the activities of NF-κB, p38, and ERK1/2 and the expression of nuclear factor of activated T-cell cytoplasmic 1 in RAW264.7 cells. Calcium hydroxide also rescued the P. endodontalis LPS-induced osteoclastogenesis and bone destruction in mouse calvaria. Taken together, our present results indicate that calcium hydroxide suppressed bone destruction by attenuating the virulence of P. endodontalis LPS on bone cells.

CHARACTERIZATION OF AN INTRAVENOUS LIPOPOLYSACCHARIDE INFLAMMATION MODEL IN BROILER CHICKENS

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De Boever , Sandra; Croubels , Siska; Meyer , Evelyne; Sys , Stanislas; Beyaert , Rudi; Ducatelle , Richard; De Backer , Patrick

2009-01-01

Abstract Intravenous administration of lipopolysaccharide (LPS) from Escherichia coli O127:B8 at a dose of 1,500,000 units/kg BW evoked a hypothermic response followed by a fever phase in five week old broiler chickens. The hypothermic phase coincided with a severe decrease in blood pressure. We assume that this decrease in blood pressure is, at least partly, responsible for the hypothermic phase of the body temperature curve. LPS administration also caused a decrease in circulatin...

De Novo Endotoxin-Induced Production of Antibodies against the Bile Salt Export Pump Associated with Bacterial Infection following Major Hepatectomy

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Kun-Ming Chan

2018-01-01

Full Text Available Background. Clinically severe infection-related inflammation after major liver resection may cause hyperbilirubinemia. This study aims to clarify the impact of bacterial infection and endotoxins on the hepatobiliary transporter system and to explore possible mechanisms of endotoxin-related postoperative hyperbilirubinemia. Method. Mice that underwent major hepatectomy with removal of at least 70% of liver volume were exposed to lipopolysaccharide (LPS at different dosages. Subsequently, hepatobiliary transporter compounds related to bile salt excretion were further investigated. Results. The expression of genes related to hepatobiliary transporter compounds was not significantly different in the liver tissue of mice after major hepatectomy and LPS exposure. However, bile salt export pump (BSEP protein expression within the liver tissue of mice treated with LPS after major hepatectomy was relatively weaker and was even further reduced in the high-dose LPS group. The formation of antibodies against the BSEP in response to endotoxin exposure was also detected. Conclusion. This study illustrates a possible mechanism whereby the dysfunction of hepatobiliary transporter systems caused by endotoxin-induced autoantibodies may be involved in the development of postoperative jaundice associated with bacterial infection after major hepatectomy.

Bacteroides fragilis lipopolysaccharide and inflammatory signaling in Alzheimer’s disease

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Walter J. Lukiw

2016-09-01

Full Text Available The human microbiome consists of ~3.8x1013 symbiotic microorganisms that form a highly complex and dynamic ecosystem: the gastrointestinal (GI tract constitutes the largest repository of the human microbiome by far, and its impact on human neurological health and disease is becoming increasingly appreciated. Bacteroidetes, the largest phylum of gram-negative bacteria in the GI tract microbiome, while generally beneficial to the host when confined to the GI tract, have potential to secrete a remarkably complex array of pro-inflammatory neurotoxins that include surface lipopolysaccharides (LPSs and toxic proteolytic species. The deleterious effects of these bacterial exudates appear to become more important as GI tract and blood-brain barriers alter or increase their permeability with aging and disease. For example, presence of the unique LPSs of the abundant Bacteroidetes species Bacteroides fragilis (BF-LPS in the serum represents a major contributing factor to systemic inflammation. BF-LPS is further recognized by TLR2, TLR4 and/or CD14 microglial cell receptors as are the pro-inflammatory 42 amino acid amyloid-beta (Aβ42 peptides that characterize Alzheimer’s disease (AD brain. Here we provide the first evidence that BF-LPS exposure to human primary brain cells is an exceptionally potent inducer of the pro-inflammatory transcription factor NF-kB (p50/p65 complex, a known trigger in the expression of pathogenic pathways involved in inflammatory neurodegeneration. This ‘Perspectives communication’ will in addition highlight work from recent studies that advance novel and emerging concepts on the potential contribution of microbiome-generated factors, such as BF-LPS, in driving pro-inflammatory degenerative neuropathology in the AD brain.

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

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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.

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

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Haider Raza

Full Text Available 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.

Activation of coagulation and inhibition of fibrinolysis in the lung after inhalation of lipopolysaccharide by healthy volunteers

NARCIS (Netherlands)

Maris, Nico A.; de Vos, Alex F.; Bresser, Paul; van der Zee, Jaring S.; Meijers, Joost C.; Lijnen, H. Roger; Levi, Marcel; Jansen, Henk M.; van der Poll, Tom

2005-01-01

Pneumonia is frequently associated with changes in coagulation and fibrinolysis in the bronchoalveolar space. To determine the effect of lipopolysaccharide (LPS) on the hemostatic balance in the human lung, six healthy subjects inhaled nebulized LPS or saline in a randomized cross-over study and

Computer simulation of uranyl uptake by the rough lipopolysaccharide membrane of Pseudomonas aeruginosa.

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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.

Maize root lectins mediate the interaction with Herbaspirillum seropedicae via N-acetyl glucosamine residues of lipopolysaccharides.

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Eduardo Balsanelli

Full Text Available Herbaspirillum seropedicae is a plant growth-promoting diazotrophic betaproteobacterium which associates with important crops, such as maize, wheat, rice and sugar-cane. We have previously reported that intact lipopolysaccharide (LPS is required for H. seropedicae attachment and endophytic colonization of maize roots. In this study, we present evidence that the LPS biosynthesis gene waaL (codes for the O-antigen ligase is induced during rhizosphere colonization by H. seropedicae. Furthermore a waaL mutant strain lacking the O-antigen portion of the LPS is severely impaired in colonization. Since N-acetyl glucosamine inhibits H. seropedicae attachment to maize roots, lectin-like proteins from maize roots (MRLs were isolated and mass spectrometry (MS analysis showed that MRL-1 and MRL-2 correspond to maize proteins with a jacalin-like lectin domain, while MRL-3 contains a B-chain lectin domain. These proteins showed agglutination activity against wild type H. seropedicae, but failed to agglutinate the waaL mutant strain. The agglutination reaction was severely diminished in the presence of N-acetyl glucosamine. Moreover addition of the MRL proteins as competitors in H. seropedicae attachment assays decreased 80-fold the adhesion of the wild type to maize roots. The results suggest that N-acetyl glucosamine residues of the LPS O-antigen bind to maize root lectins, an essential step for efficient bacterial attachment and colonization.

Maize root lectins mediate the interaction with Herbaspirillum seropedicae via N-acetyl glucosamine residues of lipopolysaccharides.

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Balsanelli, Eduardo; Tuleski, Thalita Regina; de Baura, Valter Antonio; Yates, Marshall Geoffrey; Chubatsu, Leda Satie; Pedrosa, Fabio de Oliveira; de Souza, Emanuel Maltempi; Monteiro, Rose Adele

2013-01-01

Herbaspirillum seropedicae is a plant growth-promoting diazotrophic betaproteobacterium which associates with important crops, such as maize, wheat, rice and sugar-cane. We have previously reported that intact lipopolysaccharide (LPS) is required for H. seropedicae attachment and endophytic colonization of maize roots. In this study, we present evidence that the LPS biosynthesis gene waaL (codes for the O-antigen ligase) is induced during rhizosphere colonization by H. seropedicae. Furthermore a waaL mutant strain lacking the O-antigen portion of the LPS is severely impaired in colonization. Since N-acetyl glucosamine inhibits H. seropedicae attachment to maize roots, lectin-like proteins from maize roots (MRLs) were isolated and mass spectrometry (MS) analysis showed that MRL-1 and MRL-2 correspond to maize proteins with a jacalin-like lectin domain, while MRL-3 contains a B-chain lectin domain. These proteins showed agglutination activity against wild type H. seropedicae, but failed to agglutinate the waaL mutant strain. The agglutination reaction was severely diminished in the presence of N-acetyl glucosamine. Moreover addition of the MRL proteins as competitors in H. seropedicae attachment assays decreased 80-fold the adhesion of the wild type to maize roots. The results suggest that N-acetyl glucosamine residues of the LPS O-antigen bind to maize root lectins, an essential step for efficient bacterial attachment and colonization.

Heme oxygenase-1 induction alters chemokine regulation and ameliorates human immunodeficiency virus-type-1 infection in lipopolysaccharide-stimulated macrophages

International Nuclear Information System (INIS)

Zhou, Zhao-Hua; Kumari, Namita; Nekhai, Sergei; Clouse, Kathleen A.; Wahl, Larry M.; Yamada, Kenneth M.; Dhawan, Subhash

2013-01-01

Highlights: •Lipopolysaccharide stimulation of heme oxygenase-1 (HO-1) ameliorated HIV-1 infection of primary human macrophages. •The partial protection by HO-1 against HIV infection was associated with induction of chemokines such as MIP1α and MIP1β. •This mechanism explains lipopolysaccharide-stimulated HO-1-mediated inhibition of HIV-1 infection of macrophages. -- Abstract: We have elucidated a putative mechanism for the host resistance against HIV-1 infection of primary human monocyte-derived macrophages (MDM) stimulated with lipopolysaccharide (LPS). We show that LPS-activated MDM both inhibited HIV-1 entry into the cells and were refractory to post-entry productive viral replication. LPS-treated cells were virtually negative for mature virions as revealed by transmission electron microscopy. LPS activation of MDM markedly enhanced the expression of heme oxygenase-1 (HO-1), a potent inducible cytoprotective enzyme. Increased HO-1 expression was accompanied by elevated production of macrophage inflammatory chemokines (MIP1α and MIP1β) by LPS-activated MDM, significantly decreased surface chemokine receptor-5 (CCR-5) expression, and substantially reduced virus replication. Treatment of cells with HO-1 inhibitor SnPP IX (tin protoporphyrin IX) attenuated the LPS-mediated responses, HIV-1 replication and secretion of MIP1α, MIP1β, and LD78β chemokines with little change in surface CCR-5 expression. These results identify a novel role for HO-1 in the modulation of host immune response against HIV infection of MDM

Long term effects of lipopolysaccharide on satellite glial cells in mouse dorsal root ganglia

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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.

Protective role of benfotiamine, a fat-soluble vitamin B1 analogue, in lipopolysaccharide-induced cytotoxic signals in murine macrophages.

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Yadav, Umesh C S; Kalariya, Nilesh M; Srivastava, Satish K; Ramana, Kota V

2010-05-15

This study was designed to investigate the molecular mechanisms by which benfotiamine, a lipid-soluble analogue of vitamin B1, affects lipopolysaccharide (LPS)-induced inflammatory signals leading to cytotoxicity in the mouse macrophage cell line RAW264.7. Benfotiamine prevented LPS-induced apoptosis, expression of the Bcl-2 family of proapoptotic proteins, caspase-3 activation, and PARP cleavage and altered mitochondrial membrane potential and release of cytochrome c and apoptosis-inducing factor and phosphorylation and subsequent activation of p38-MAPK, stress-activated kinases (SAPK/JNK), protein kinase C, and cytoplasmic phospholipase A2 in RAW cells. Further, phosphorylation and degradation of inhibitory kappaB and consequent activation and nuclear translocation of the redox-sensitive transcription factor NF-kappaB were significantly prevented by benfotiamine. The LPS-induced increased expression of cytokines and chemokines and the inflammatory marker proteins iNOS and COX-2 and their metabolic products NO and PGE(2) was also blocked significantly. Thus, our results elucidate the molecular mechanism of the anti-inflammatory action of benfotiamine in LPS-induced inflammation in murine macrophages. Benfotiamine suppresses oxidative stress-induced NF-kappaB activation and prevents bacterial endotoxin-induced inflammation, indicating that vitamin B1 supplementation could be beneficial in the treatment of inflammatory diseases. Copyright 2010 Elsevier Inc. All rights reserved.

Lipopolysaccharide induces amyloid formation of antimicrobial peptide HAL-2.

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Wang, Jiarong; Li, Yan; Wang, Xiaoming; Chen, Wei; Sun, Hongbin; Wang, Junfeng

2014-11-01

Lipopolysaccharide (LPS), the important component of the outer membrane of Gram-negative bacteria, contributes to the integrity of the outer membrane and protects the cell against bactericidal agents, including antimicrobial peptides. However, the mechanisms of interaction between antimicrobial peptides and LPS are not clearly understood. Halictines-2 (HAL-2), one of the novel antimicrobial peptides, was isolated from the venom of the eusocial bee Halictus sexcinctus. HAL-2 has exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria and even against cancer cells. Here, we studied the interactions between HAL-2 and LPS to elucidate the antibacterial mechanism of HAL-2 in vitro. Our results show that HAL-2 adopts a significant degree of β-strand structure in the presence of LPS. LPS is capable of inducing HAL-2 amyloid formation, which may play a vital role in its antimicrobial activity. Copyright © 2014 Elsevier B.V. All rights reserved.

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

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

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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.

Lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFα) blunt the response of Neuropeptide Y/Agouti-related peptide (NPY/AgRP) glucose inhibited (GI) neurons to decreased glucose.

Science.gov (United States)

Hao, Lihong; Sheng, Zhenyu; Potian, Joseph; Deak, Adam; Rohowsky-Kochan, Christine; Routh, Vanessa H

2016-10-01

A population of Neuropeptide Y (NPY) neurons which co-express Agouti-related peptide (AgRP) in the arcuate nucleus of the hypothalamus (ARC) are inhibited at physiological levels of brain glucose and activated when glucose levels decline (e.g. glucose-inhibited or GI neurons). Fasting enhances the activation of NPY/AgRP-GI neurons by low glucose. In the present study we tested the hypothesis that lipopolysaccharide (LPS) inhibits the enhanced activation of NPY/AgRP-GI neurons by low glucose following a fast. Mice which express green fluorescent protein (GFP) on their NPY promoter were used to identify NPY/AgRP neurons. Fasting for 24h and LPS injection decreased blood glucose levels. As we have found previously, fasting increased c-fos expression in NPY/AgRP neurons and increased the activation of NPY/AgRP-GI neurons by decreased glucose. As we predicted, LPS blunted these effects of fasting at the 24h time point. Moreover, the inflammatory cytokine tumor necrosis factor alpha (TNFα) blocked the activation of NPY/AgRP-GI neurons by decreased glucose. These data suggest that LPS and TNFα may alter glucose and energy homeostasis, in part, due to changes in the glucose sensitivity of NPY/AgRP neurons. Interestingly, our findings also suggest that NPY/AgRP-GI neurons use a distinct mechanism to sense changes in extracellular glucose as compared to our previous studies of GI neurons in the adjacent ventromedial hypothalamic nucleus. Copyright © 2016 Elsevier B.V. All rights reserved.

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...

Modulation of lipopolysaccharide-induced chorioamnionitis by Ureaplasma parvum in sheep.

Science.gov (United States)

Snyder, Candice C; Wolfe, Katherine B; Gisslen, Tate; Knox, Christine L; Kemp, Matthew W; Kramer, Boris W; Newnham, John P; Jobe, Alan H; Kallapur, Suhas G

2013-05-01

Ureaplasma colonization in the setting of polymicrobial flora is common in women with chorioamnionitis, and is a risk factor for preterm delivery and neonatal morbidity. We hypothesized that Ureaplasma colonization of amniotic fluid would modulate chorioamnionitis induced by Escherichia coli lipopolysaccharide (LPS). Sheep received intraamniotic (IA) injections of media (control) or live Ureaplasma either 7 or 70 days before delivery. Another group received IA LPS 2 days before delivery. To test for interactions, U parvum-exposed animals were challenged with IA LPS, and delivered 2 days later. All animals were delivered preterm at 125 ± 1 day of gestation. Both IA Ureaplasma and LPS induced leukocyte infiltration of chorioamnion. LPS greatly increased the expression of proinflammatory cytokines and myeloperoxidase in leukocytes, while Ureaplasma alone caused modest responses. Interestingly, 7-day but not 70-day Ureaplasma exposure significantly down-regulated LPS-induced proinflammatory cytokines and myeloperoxidase expression in the chorioamnion. Acute (7-day) U parvum exposure can suppress LPS-induced chorioamnionitis. Copyright © 2013 Mosby, Inc. All rights reserved.

Salmonella O48 Serum Resistance is Connected with the Elongation of the Lipopolysaccharide O-Antigen Containing Sialic Acid

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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.

A fluorescent probe distinguishes between inhibition of early and late steps of lipopolysaccharide biogenesis in whole cells

Science.gov (United States)

Moison, Eileen; Xie, Ran; Zhang, Ge; Lebar, Matthew D.; Meredith, Timothy C.; Kahne, Daniel

2017-01-01

Lipopolysaccharide (LPS) biogenesis in Gram-negative organisms involves its biosynthesis in the cytoplasm and subsequent transport across three cellular compartments to the cell surface. We developed a fluorescent probe that allows us to determine the spatial distribution of LPS in whole cells. We show that polymyxin B nonapeptide (PMBN) containing a dansyl fluorophore specifically binds to LPS in membranes. We show that this probe detects decreases in LPS levels on the cell surface when LPS biosynthesis is inhibited at an early step. We also can detect accumulation of LPS in particular subcellular locations when LPS assembly is blocked during transport, allowing us to differentiate inhibitors targeting early and late stages of LPS biogenesis. PMID:28248483

Effect of 60Co γ-rays on PWM and LPS induced lymphocytes

International Nuclear Information System (INIS)

Su Liaoyuan; Liu Keliang; Liu Fenju

1987-01-01

The relationship between lymphocytes induced by PWM (pokeweed mitogen) and LPS (lipopolysaccharide) was investigated by means of 3 H-TdR incorporation. The study showed that, in vitro, PWM-induced cells were able to promote the stimulating effect of LPS to B lymphocytes. The stimulating effect of PWM-induced cells was obviously weakened after PWM cells being irradiated with γ-rays. When PWM-induced cells and LPS-induced cells were incubated together, with one kind of cells exposed to 60 Co γ-ray, incorporation value of 3 H-TdR became much smaller and the synergetic function disappeared, especially, when PWM-induced cells were irradiated. For patients suffering from carcinoma of nasopharynx, while treated with 60 Co γ-rays, the incorporation value in LPS-induced cells approached normal level, meanwhile, the incorporation value in PEM-induced cells reduced significantly and the stimulating effect of PWM-induced cells on LPS-induced cells became much weaker. The facts described above demonstrated that PWM-induced cells have the function of T-helper cells and play more important role in the synergy than LPS-induced cells

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.

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 ...

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

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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

Monoclonal antibody against Porphyromonas (Bacteroides) endodontalis lipopolysaccharide and application of the antibody for direct identification of the species.

Science.gov (United States)

Hanazawa, S; Sagiya, T; Kitami, H; Ohta, K; Nishikawa, H; Kitano, S

1991-01-01

The aim of the present study was to develop a monoclonal antibody that recognizes the shared antigen of Porphyromonas endodontalis so that we could use the antibody in direct identification and detection of P. endodontalis in infectious material from apical periodontal patients. We established a hybridoma cell line producing monoclonal antibody (BEB5) specific for P. endodontalis. BEB5 antibody reacted with all of the P. endodontalis strains tested, but not with any of the other black-pigmented Porphyromonas and Bacteroides spp. The antibody reacted specifically with the lipopolysaccharide (LPS) of three P. endodontalis strains of different serotypes (O1K1, O1K2, and O1K-). Western blotting (immunoblotting) analysis confirmed the specificity of the antibody to these LPSs, because the antibody recognized the typical "repetitive ladder" pattern characteristic of LPS on sodium dodecyl sulfate-polyacrylamide electrophoretic gels. These observations demonstrate that P. endodontalis LPS is the shared antigen of this species. The antibody can specifically identify P. endodontalis on nitrocellulose membrane blots of bacterial colonies grown on agar. The antibody is also capable of directly detecting the presence of P. endodontalis in infectious material by immunoslot blot assay. These results indicate that LPS is the shared antigen of P. endodontalis and that BEB5 antibody against LPS is a useful one for direct identification and detection of the organisms in samples from apical periodontal patients. Images PMID:1774262

SILAC-MS Based Characterization of LPS and Resveratrol Induced Changes in Adipocyte Proteomics

DEFF Research Database (Denmark)

Nøhr, Mark K; Kroager, Toke P; Sanggaard, Kristian W

2016-01-01

Adipose tissue inflammation is believed to play a pivotal role in the development obesity-related morbidities such as insulin resistance. However, it is not known how this (low-grade) inflammatory state develops. It has been proposed that the leakage of lipopolysaccharides (LPS), originating from...

LYATK1 potently inhibits LPS-mediated pro-inflammatory response

Energy Technology Data Exchange (ETDEWEB)

Xi, Feng [Department of Intensive Care Unit, Taixing People" ' s Hospital, Taixing, Jiangsu Province, 225400 (China); Liu, Yuan [Department of Ophthalmology, Nanjing First Hospital, Nanjing Medical University, Nanjing (China); Wang, Xiujuan; Kong, Wei [Department of Intensive Care Unit, Taixing People" ' s Hospital, Taixing, Jiangsu Province, 225400 (China); Zhao, Feng, E-mail: taixingzhaofeng163@163.com [Department of Intensive Care Unit, Taixing People" ' s Hospital, Taixing, Jiangsu Province, 225400 (China)

2016-01-29

Lipopolysaccharide (LPS)-primed monocytes/macrophages produce pro-inflammatory cytokines, which could lead to endotoxin shock. TGF-β-activated kinase1 (TAK1) activation is involved in the process. In the current study, we studied the potential effect of a selective TAK1 inhibitor, LYTAK1, on LPS-stimulated response both in vitro and in vivo. We demonstrated that LYTAK1 inhibited LPS-induced mRNA expression and production of several pro-inflammatory cytokines [interleukin 1β (IL-1β), tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6)] in RAW 264.7 macrophages. LYTAK1's activity was almost nullified with TAK1 shRNA-knockdown. Meanwhile, in both primary mouse bone marrow derived macrophages (BMDMs) and human peripheral blood mononuclear cells (PBMCs), LPS-induced pro-inflammatory cytokine production was again attenuated with LYTAK1 co-treatment. Molecularly, LYTAK1 dramatically inhibited LPS-induced TAK1-nuclear factor kappa B (NFκB) and mitogen-activated protein kinase (Erk, Jnk and p38) activation in RAW 264.7 cells, mouse BMDMs and human PBMCs. In vivo, oral administration of LYTAK1 inhibited LPS-induced activation of TAK1-NFκB-p38 in ex-vivo cultured PBMCs, and cytokine production and endotoxin shock in mice. Together, these results demonstrate that LYTAK1 inhibits LPS-induced production of several pro-inflammatory cytokines and endotoxin shock probably through blocking TAK1-regulated signalings. - Highlights: • LYTAK1 inhibits LPS-induced pro-inflammatory cytokine production in RAW 264.7 cells. • The effect by LYTAK1 is more potent than other known TAK1 inhibitors. • LYTAK1 inhibits LPS-induced cytokine production in primary macrophages/monocytes. • LYTAK1 inhibits LPS-induced TAK1-NFκB and MAPK activation in macrophages/monocytes. • LYTAK1 gavage inhibits LPS-induced endotoxin shock and cytokine production in mice.

LYATK1 potently inhibits LPS-mediated pro-inflammatory response

International Nuclear Information System (INIS)

Xi, Feng; Liu, Yuan; Wang, Xiujuan; Kong, Wei; Zhao, Feng

2016-01-01

Lipopolysaccharide (LPS)-primed monocytes/macrophages produce pro-inflammatory cytokines, which could lead to endotoxin shock. TGF-β-activated kinase1 (TAK1) activation is involved in the process. In the current study, we studied the potential effect of a selective TAK1 inhibitor, LYTAK1, on LPS-stimulated response both in vitro and in vivo. We demonstrated that LYTAK1 inhibited LPS-induced mRNA expression and production of several pro-inflammatory cytokines [interleukin 1β (IL-1β), tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6)] in RAW 264.7 macrophages. LYTAK1's activity was almost nullified with TAK1 shRNA-knockdown. Meanwhile, in both primary mouse bone marrow derived macrophages (BMDMs) and human peripheral blood mononuclear cells (PBMCs), LPS-induced pro-inflammatory cytokine production was again attenuated with LYTAK1 co-treatment. Molecularly, LYTAK1 dramatically inhibited LPS-induced TAK1-nuclear factor kappa B (NFκB) and mitogen-activated protein kinase (Erk, Jnk and p38) activation in RAW 264.7 cells, mouse BMDMs and human PBMCs. In vivo, oral administration of LYTAK1 inhibited LPS-induced activation of TAK1-NFκB-p38 in ex-vivo cultured PBMCs, and cytokine production and endotoxin shock in mice. Together, these results demonstrate that LYTAK1 inhibits LPS-induced production of several pro-inflammatory cytokines and endotoxin shock probably through blocking TAK1-regulated signalings. - Highlights: • LYTAK1 inhibits LPS-induced pro-inflammatory cytokine production in RAW 264.7 cells. • The effect by LYTAK1 is more potent than other known TAK1 inhibitors. • LYTAK1 inhibits LPS-induced cytokine production in primary macrophages/monocytes. • LYTAK1 inhibits LPS-induced TAK1-NFκB and MAPK activation in macrophages/monocytes. • LYTAK1 gavage inhibits LPS-induced endotoxin shock and cytokine production in mice.

Atomic force microscopy observation of lipopolysaccharide-induced cardiomyocyte cytoskeleton reorganization.

Science.gov (United States)

Wang, Liqun; Chen, Tangting; Zhou, Xiang; Huang, Qiaobing; Jin, Chunhua

2013-08-01

We applied atomic force microscopy (AFM) to observe lipopolysaccharide (LPS)-induced intracellular cytoskeleton reorganization in primary cardiomyocytes from neonatal mouse. The nonionic detergent Triton X-100 was used to remove the membrane, soluble proteins, and organelles from the cell. The remaining cytoskeleton can then be directly visualized by AFM. Using three-dimensional technique of AFM, we were able to quantify the changes of cytoskeleton by the "density" and total "volume" of the cytoskeleton fibers. Compared to the control group, the density of cytoskeleton was remarkably decreased and the volume of cytoskeleton was significantly increased after LPS treatment, which suggests that LPS may induce the cytoskeleton reorganization and change the cardiomyocyte morphology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analyses of performance of novel sensors with different coatings for detection of Lipopolysaccharide

KAUST Repository

Mohd. Syaifudin, A. R.; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Matias, Ignacio R.; Goicoechea, J.; Kosel, Jü rgen; Gooneratne, Chinthaka Pasan

2011-01-01

Interdigital sensors have been widely used for non-destructive applications. New types of planar interdigital sensors have been fabricated with different coating materials to assess the response to Lipopolysaccharide, LPS. All the coatings were

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

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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.

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

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

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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

Post-ruminal branched-chain amino acid supplementation and intravenous lipopolysaccharide infusion alters blood metabolites, rumen fermentation, and nitrogen balance of beef steers.

Science.gov (United States)

Löest, C A; Gilliam, G G; Waggoner, J W; Turner, J L

2018-04-27

Steers exposed to an endotoxin may require additional branched-chain AA (BCAA) to support an increase in synthesis of immune proteins. This study evaluated effects of bacterial lipopolysaccharide (LPS) and BCAA supplementation on blood metabolites and N balance of 20 ruminally-cannulated steers (177 ± 4.2 kg BW). The experiment was a randomized block design, with 14-d adaptation to metabolism stalls and diet (DM fed = 1.5% BW) and 6-d collection. Treatments were a 2 × 2 factorial of LPS (0 vs 1.0 to 1.5 μg/kg BW; -LPS vs +LPS) and BCAA (0 vs 35 g/d; -BCAA vs +BCAA). The LPS in 100 mL sterile saline was infused (1 mL/min via i.v. catheter) on d 15. The BCAA in an essential AA solution were abomasally infused (900 mL/d) 3 times daily in equal portions beginning on d 7. Blood, rumen fluid, and rectal temperature were collected on d 15 at h 0, 2, 4, 8, 12, and 24 after LPS infusion. Feces and urine were collected from d 16 to 20. Rectal temperatures were greater for +LPS vs. -LPS steers at 4 h and lower at 8 h after LPS infusion (LPS h, P BCAA than -BCAA steers at 12 h after LPS infusion (BCAA × h, P BCAA, P BCAA than -BCAA steers at 0 h and 24 h after LPS infusion (BCAA × h, P ≤ 0.05). Steers receiving +LPS had lower rumen pH at 8 h, greater total VFA at 8 h, and lower rumen NH3 at 24 h after LPS infusion compared with -LPS steers (LPS × h, P ≤ 0.04). Total tract passage rates, DM, OM, NDF, ADF, and N intake, fecal N, digested N, and retained N were lower (P BCAA vs -BCAA steers. The absence of LPS × BCAA interactions (P ≥ 0.20) for N balance indicated that post-ruminal supplementation of BCAA did not alleviate the negative effects of endotoxin on N utilization by growing steers.

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

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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.

Study of Nitric Oxide production by murine peritoneal macrophages induced by Brucella Lipopolysaccharide

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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

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 ...

Caffeoyl glucosides from Nandina domestica inhibit LPS-induced endothelial inflammatory responses.

Science.gov (United States)

Kulkarni, Roshan R; Lee, Wonhwa; Jang, Tae Su; Lee, JungIn; Kwak, Soyoung; Park, Mi Seon; Lee, Hyun-Shik; Bae, Jong-Sup; Na, MinKyun

2015-11-15

Endothelial dysfunction is a key pathological feature of many inflammatory diseases, including sepsis. In the present study, a new caffeoyl glucoside (1) and two known caffeoylated compounds (2 and 3) were isolated from the fruits of Nandina domestica Thunb. (Berberidaceae). The compounds were investigated for their effects against lipopolysaccharide (LPS)-mediated endothelial inflammatory responses. At 20 μM, 1 and 2 inhibited LPS-induced hyperpermeability, adhesion, and migration of leukocytes across a human endothelial cell monolayer in a dose-dependent manner suggesting that 1 and 2 may serve as potential scaffolds for the development of therapeutic agents to treat vascular inflammatory disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stimulation of interleukin-6 production of periodontal ligament cells by Porphyromonas endodontalis lipopolysaccharide.

Science.gov (United States)

Ogura, N; Shibata, Y; Kamino, Y; Matsuda, U; Hayakawa, M; Oikawa, T; Takiguchi, H; Izumi, H; Abiko, Y

1994-12-01

Interleukin-6 (IL-6), which is a multifunctional cytokine, has important roles in acute and chronic inflammation and may also be implicated in bone resorption. We examined the IL-6 production in periodontal ligament (PDL) cells which were treated with lipopolysaccharide (LPS) from several oral inflammatory pathogens. The LPS from Porphyromonas endodontalis, which was isolated from infected root canals and radicular cyst fluids, was more potent than the LPS from any other periodontal organisms examined. P. endodontalis LPS stimulated IL-6 release from PDL cells in a time- and dose-dependent manner. Northern blot hybridization analysis revealed that the IL-6 mRNA level in PDL cells was increased by P. endodontalis LPS. These results suggest that stimulation of the IL-6 release of PDL cells by P. endodontalis LPS may have a role in the progression of inflammation and alveolar bone resorption in periodontal and periapical diseases.

Melatonin protects against myocardial hypertrophy induced by lipopolysaccharide.

Science.gov (United States)

Lu, Qi; Yi, Xin; Cheng, Xiang; Sun, Xiaohui; Yang, Xiangjun

2015-04-01

Melatonin is thought to have the ability of antiatherogenic, antioxidant, and vasodilatory. It is not only a promising protective in acute myocardial infarction but is also a useful tool in the treatment of pathological remodeling. However, its role in myocardial hypertrophy remains unclear. In this study, we investigated the protective effects of melatonin on myocardial hypertrophy induced by lipopolysaccharide (LPS) and to identify their precise mechanisms. The cultured myocardial cell was divided into six groups: control group, LPS group, LPS + ethanol (4%), LPS + melatonin (1.5 mg/ml) group, LPS + melatonin (3 mg/ml) group, and LPS + melatonin (6 mg/ml) group. The morphologic change of myocardial cell was observed by inverted phase contrast microscope. The protein level of myocardial cell was measured by Coomassie brilliant blue protein kit. The secretion level of tumor necrosis factor-α (TNF-α) was evaluated by enzyme-linked immunosorbent assay (ELISA). Ca(2+) transient in Fura-2/AM-loaded cells was measured by Till image system. The expression of Ca(2+)/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) was measured by Western blot analysis. Our data demonstrated that LPS induced myocardial hypertrophy, promoted the secretion levels of TNF-α, and increased Ca(2+) transient level and the expression of CaMKII and CaN. Administration of melatonin 30 min prior to LPS stimulation dose-dependently attenuated myocardial hypertrophy. In conclusion, the results revealed that melatonin had the potential to protect against myocardial hypertrophy induced by LPS in vitro through downregulation of the TNF-α expression and retains the intracellular Ca(2+) homeostasis.

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

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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

Radioprotective Properties of Detoxified Lipid A from Salmonella minnesota R595

Science.gov (United States)

1986-01-01

irradiated animals treated with bacterial endotoxins. Am. J. Physiol. 191, 124-130 (1957). 3. M. PARANT, Effect of LPS on nonspecific recistance to...Salmonella minnesota R595. Radiat. Res. 107, 107-114(1986). . in the past, the toxicity of bacterial lipopolysaccharide (LPS) or its principal bioactive...contained significantly less CSA than those receiving either GLY or LAD. DISCUSSION The radioprotective effect of bacterial endotoxins has been known for over

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.

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.

Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination

International Nuclear Information System (INIS)

Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani; Qiao, Juan; Lu, Yun

2016-01-01

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.

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

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

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.

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

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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

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.

Carbachol ameliorates lipopolysaccharide-induced intestinal epithelial tight junction damage by down-regulating NF-{kappa}{beta} and myosin light-chain kinase pathways

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ying [Department of Anesthesia, Critical Care Medicine and Emergency Medicine Center, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei Province, People' s Republic of China (China); Li, Jianguo, E-mail: 2010lijianguo@sina.cn [Department of Anesthesia, Critical Care Medicine and Emergency Medicine Center, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei Province, People' s Republic of China (China)

2012-11-16

Highlights: Black-Right-Pointing-Pointer Carbachol reduced the lipopolysaccharide-induced intestinal barrier breakdown. Black-Right-Pointing-Pointer Carbachol ameliorated the lipopolysaccharide-induced ileal tight junction damage. Black-Right-Pointing-Pointer Carbachol prevented the LPS-induced NF-{kappa}{beta} and myosin light-chain kinase activation. Black-Right-Pointing-Pointer Carbachol exerted its beneficial effects in an {alpha}7 nicotinic receptor-dependent manner. -- Abstract: Carbachol is a cholinergic agonist that protects the intestines after trauma or burn injury. The present study determines the beneficial effects of carbachol and the mechanisms by which it ameliorates the lipopolysaccharide (LPS)-induced intestinal barrier breakdown. Rats were injected intraperitoneally with 10 mg/kg LPS. Results showed that the gut barrier permeability was reduced, the ultrastructural disruption of tight junctions (TJs) was prevented, the redistribution of zonula occludens-1 and claudin-2 proteins was partially reversed, and the nuclear factor-kappa beta (NF-{kappa}{beta}) and myosin light-chain kinase (MLCK) activation in the intestinal epithelium were suppressed after carbachol administration in LPS-exposed rats. Pretreatment with the {alpha}7 nicotinic acetylcholine receptor ({alpha}7nAchR) antagonist {alpha}-bungarotoxin blocked the protective action of carbachol. These results suggested that carbachol treatment can protect LPS-induced intestinal barrier dysfunction. Carbachol exerts its beneficial effect on the amelioration of the TJ damage by inhibiting the NF-{kappa}{beta} and MLCK pathways in an {alpha}7nAchR-dependent manner.

Edaravone abrogates LPS-induced behavioral anomalies, neuroinflammation and PARP-1.

Science.gov (United States)

Sriram, Chandra Shaker; Jangra, Ashok; Gurjar, Satendra Singh; Mohan, Pritam; Bezbaruah, Babul Kumar

2016-02-01

Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA nick-sensor enzyme that functions at the center of cellular stress response and affects the immune system at several key points, and thus modulates inflammatory diseases. Our previous study demonstrated that lipopolysaccharide (LPS)-induced depressive-like behavior in mice can be ameliorated by 3-aminobenzamide, which is a PARP-1 inhibitor. In the present study we've examined the effect of a free radical scavenger, edaravone pretreatment against LPS-induced anxiety and depressive-like behavior as well as various hippocampal biochemical parameters including PARP-1. Male Swiss albino mice were treated with edaravone (3 & 10mg/kgi.p.) once daily for 14days. On the 14th day 30min after edaravone treatment mice were challenged with LPS (1mg/kgi.p.). After 3h and 24h of LPS administration we've tested mice for anxiety and depressive-like behaviors respectively. Western blotting analysis of PARP-1 in hippocampus was carried out after 12h of LPS administration. Moreover, after 24h of LPS administration serum corticosterone, hippocampal BDNF, oxido-nitrosative stress and pro-inflammatory cytokines were estimated by ELISA. Results showed that pretreatment of edaravone (10mg/kg) ameliorates LPS-induced anxiety and depressive-like behavior. Western blotting analysis showed that LPS-induced anomalous expression of PARP-1 significantly reverses by the pretreatment of edaravone (10mg/kg). Biochemical analyses revealed that LPS significantly diminishes BDNF, increases pro-inflammatory cytokines and oxido-nitrosative stress in the hippocampus. However, pretreatment with edaravone (10mg/kg) prominently reversed all these biochemical alterations. Our study emphasized that edaravone pretreatment prevents LPS-induced anxiety and depressive-like behavior, mainly by impeding the inflammation, oxido-nitrosative stress and PARP-1 overexpression. Copyright © 2015. Published by Elsevier Inc.

Protective effects of kaempferol on lipopolysaccharide-induced mastitis in mice.

Science.gov (United States)

Cao, Rongfeng; Fu, Kaiqiang; Lv, Xiaopei; Li, Weishi; Zhang, Naisheng

2014-10-01

Kaempferol isolated from the root of Zingiberaceae plants galangal and other Chinese herbal medicines have been reported to have anti-inflammatory properties. However, the anti-inflammatory effects of kaempferol on lipopolysaccharide (LPS)-induced mastitis are unknown and their underlying molecular mechanisms remain to be explored. The aim of this study was to evaluate the effects of kaempferol on LPS-induced mouse mastitis. The mouse model of mastitis was induced by injection of LPS through the duct of mammary gland. Kaempferol was injected 1 h before and 12 h after induction of LPS intraperitoneally. The present results showed that kaempferol markedly reduced infiltration of neutrophilic granulocyte, activation of myeloperoxidase (MPO), expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in a dose-dependent manner, which were increased in LPS-induced mouse mastitis. Furthermore, kaempferol suppressed the phosphorylation of nuclear factor-κB (NF-κB) p65 subunit and the degradation of its inhibitor IκBα. All results suggest that anti-inflammatory effects of kaempferol against the LPS-induced mastitis possibly through inhibition of the NF-κB signaling pathway. Kaempferol may be a potential therapeutic agent for mastitis.

Inhibition of lipopolysaccharide induced acute inflammation in lung by chlorination.

Science.gov (United States)

Zhang, Jinshan; Xue, Jinling; Xu, Bi; Xie, Jiani; Qiao, Juan; Lu, Yun

2016-02-13

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. Copyright © 2015 Elsevier B.V. All rights reserved.

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...

Murine P-glycoprotein deficiency alters intestinal injury repair and blunts lipopolysaccharide-induced radioprotection.

Science.gov (United States)

Staley, Elizabeth M; Yarbrough, Vanisha R; Schoeb, Trenton R; Daft, Joseph G; Tanner, Scott M; Steverson, Dennis; Lorenz, Robin G

2012-09-01

P-glycoprotein (P-gp) has been reported to increase stem cell proliferation and regulate apoptosis. Absence of P-gp results in decreased repair of intestinal epithelial cells after chemical injury. To further explore the mechanisms involved in the effects of P-gp on intestinal injury and repair, we used the well-characterized radiation injury model. In this model, injury repair is mediated by production of prostaglandins (PGE(2)) and lipopolysaccharide (LPS) has been shown to confer radioprotection. B6.mdr1a(-/-) mice and wild-type controls were subjected to 12 Gy total body X-ray irradiation and surviving crypts in the proximal jejunum and distal colon were evaluated 3.5 days after irradiation. B6.mdr1a(-/-) mice exhibited normal baseline stem cell proliferation and COX dependent crypt regeneration after irradiation. However, radiation induced apoptosis was increased and LPS-induced radioprotection was blunted in the C57BL6.mdr1a(-/-) distal colon, compared to B6 wild-type controls. The LPS treatment induced gene expression of the radioprotective cytokine IL-1α, in B6 wild-type controls but not in B6.mdr1a(-/-) animals. Lipopolysaccharid-induced radioprotection was absent in IL-1R1(-/-) animals, indicating a role for IL-1α in radioprotection, and demonstrating that P-gp deficiency interferes with IL-1α gene expression in response to systemic exposure to LPS.

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

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.

Annexin A5 binds to lipopolysaccharide and reduces its endotoxin activity.

Science.gov (United States)

Rand, Jacob H; Wu, Xiao-Xuan; Lin, Elaine Y; Griffel, Alexander; Gialanella, Philip; McKitrick, John C

2012-01-01

Annexin A5 (AnxA5) has a high affinity for phosphatidylserine. The protein is widely used to detect apoptotic cells because phosphatidylserine, a phospholipid that is normally present in the inner leaflets of cytoplasmic membranes, becomes translocated to the outer leaflets during programmed cell death. Here we report the novel observation that AnxA5 binds to Gram-negative bacteria via the lipid A domain of lipopolysaccharide (LPS). Binding of AnxA5 to bacteria was measured quantitatively, confirmed by fluorescence microscopy, and found to be inhibited by antibodies against lipid A. AnxA5 also bound to purified dot-blotted LPS and lipid A. Through ellipsometry, we found that the binding of AnxA5 to purified LPS was calcium dependent and rapid and showed a high affinity-characteristics similar to those of AnxA5 binding to phosphatidylserine. Initial functional studies indicated that AnxA5 can affect LPS activities. AnxA5 inhibited LPS-mediated gelation in the Limulus amebocyte lysate assay. Incubation of LPS with the protein reduced the quantity of tumor necrosis factor alpha (TNF-α) released by cultured monocytes compared to that released upon incubation with LPS alone. Initial in vivo experiments indicated that injection of mice with LPS preincubated with AnxA5 produced serum TNF-α levels lower than those seen after injection of LPS alone. These data demonstrate that AnxA5 binds to LPS and open paths to investigation of the potential biological and therapeutic implications of this interaction. AnxA5 is highly expressed in cells that have a barrier function-including, among others, vascular endothelium, placental trophoblasts, and epithelial cells lining bile ducts, renal tubules, mammary ducts, and nasal epithelium. The protein has been well characterized for its binding to phospholipid bilayers that contain phosphatidylserine. This report of a previously unrecognized activity of AnxA5 opens the door to investigation of the possibility that this binding may have

Dexmedetomidine reduces lipopolysaccharide induced neuroinflammation, sickness behavior, and anhedonia.

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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.

SILAC-MS Based Characterization of LPS and Resveratrol Induced Changes in Adipocyte Proteomics - Resveratrol as Ameliorating Factor on LPS Induced Changes.

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Mark K Nøhr

Full Text Available Adipose tissue inflammation is believed to play a pivotal role in the development obesity-related morbidities such as insulin resistance. However, it is not known how this (low-grade inflammatory state develops. It has been proposed that the leakage of lipopolysaccharides (LPS, originating from the gut microbiota, through the gut epithelium could drive initiation of inflammation. To get a better understanding of which proteins and intracellular pathways are affected by LPS in adipocytes, we performed SILAC proteomic analysis and identified proteins that were altered in expression. Furthermore, we tested the anti-inflammatory compound resveratrol. A total of 927 proteins were quantified by the SILAC method and of these 57- and 64 were significantly up- and downregulated by LPS, respectively. Bioinformatic analysis (GO analysis revealed that the upregulated proteins were especially involved in the pathways of respiratory electron transport chain and inflammation. The downregulated proteins were especially involved in protein glycosylation. One of the latter proteins, GALNT2, has previously been described to regulate the expression of liver lipases such as ANGPTL3 and apoC-III affecting lipid metabolism. Furthermore, LPS treatment reduced the protein levels of the insulin sensitizing adipokine, adiponectin, and proteins participating in the final steps of triglyceride- and cholesterol synthesis. Generally, resveratrol opposed the effect induced by LPS and, as such, functioning as an ameliorating factor in disease state. Using an unbiased proteomic approach, we present novel insight of how the proteome is altered in adipocytes in response to LPS as seen in obesity. We suggest that LPS partly exerts its detrimental effects by altering glycosylation processes of the cell, which is starting to emerge as important posttranscriptional regulators of protein expression. Furthermore, resveratrol could be a prime candidate in ameliorating dysfunctioning

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

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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

In vitro effects of sodium bicarbonate buffer on rumen fermentation, levels of lipopolysaccharide and biogenic amine, and composition of rumen microbiota.

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Mao, Shengyong; Huo, Wenjie; Liu, Junhua; Zhang, Ruiyang; Zhu, Weiyun

2017-03-01

Diets containing high levels of carbohydrates provoke a rapid decrease of rumen pH and high levels of biogenic amines and lipopolysaccharides (LPS), which severely impair the health and performance of ruminants. The goal of this study was to evaluate the effects of sodium bicarbonate (BC) buffer on rumen fermentation, levels of LPS and biogenic amine, and composition of rumen microbiota using in vitro rumen cultures. Sodium bicarbonate supplementation increased (P < 0.05) the final pH levels and concentrations of total volatile fatty acids and LPS, as well as the proportions of acetate, propionate, isobutyrate, isovalerate and valerate, and it decreased (P < 0.05) the proportion of butyrate and the levels of lactic acid, methylamine, tryptamine, tyramine, histamine and putrescine compared with the control. Pyrosequencing of the 16S rRNA gene showed that BC inclusion increased (P < 0.05) the bacterial diversity index compared with the control. Adding BC also decreased (P < 0.05) the relative abundance of Streptococcus and Butyrivibrio and increased (P < 0.05) the proportions of Ruminococcus, Succinivibrio and Prevotella. Sodium bicarbonate supplementation has beneficial effects in the reduction of bioamine levels and the increase in ruminal pH, and in modifying the microbial ecology of the rumen; however, it results in an accumulation of LPS under high-grain diet conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Lipopolysaccharide (LPS)-mediated macrophage activation: the role of calcium in the generation of tumoricidal activity

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Drysdale, B.E.; Shin, H.S.

1986-01-01

As the authors reported, calcium ionophore, A23187, activates macrophages (M theta) for tumor cell killing and the activated M theta produce a soluble cytotoxic factor (M theta-CF) that is similar if not identical to tumor necrosis factor. Based on these observations they have investigated whether calcium is involved in the activation mediated by another potent M theta activator, LPS. The authors have shown that A23187 caused uptake of extracellular 45 Ca ++ but LPS did not. They have examined the effect of depleting extracellular calcium by using medium containing no added calcium containing 1.0 mM EGTA. In no case did depletion result in decreased M theta-CF production by the M theta activated with LPS. Measurements using the fluorescent, intracellular calcium indicator, Quin 2 have also been performed. While ionomycin, caused a rapid change in the Quin-2 signal, LPS at a concentration even in excess of that required to activate the M theta caused no change in the signal. When high doses of Quin 2 or another intracellular chelator, 8-(diethylaminol-octyl-3,4,5-trimethoxybenzoate, were used to treat M theta, M theta-CF production decreased and cytotoxic activity was impaired. These data indicate that one or more of the processes involved in M theta-CF production does require calcium, but that activation mediated by LPS occurs without the influx of extracellular calcium or redistribution of intracellular calcium

Fatty Acid Oxidation Compensates for Lipopolysaccharide-Induced Warburg Effect in Glucose-Deprived Monocytes

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Nora Raulien

2017-05-01

Full Text Available Monocytes enter sites of microbial or sterile inflammation as the first line of defense of the immune system and initiate pro-inflammatory effector mechanisms. We show that activation with bacterial lipopolysaccharide (LPS induces them to undergo a metabolic shift toward aerobic glycolysis, similar to the Warburg effect observed in cancer cells. At sites of inflammation, however, glucose concentrations are often drastically decreased, which prompted us to study monocyte function under conditions of glucose deprivation and abrogated Warburg effect. Experiments using the Seahorse Extracellular Flux Analyzer revealed that limited glucose supply shifts monocyte metabolism toward oxidative phosphorylation, fueled largely by fatty acid oxidation at the expense of lipid droplets. While this metabolic state appears to provide sufficient energy to sustain functional properties like cytokine secretion, migration, and phagocytosis, it cannot prevent a rise in the AMP/ATP ratio and a decreased respiratory burst. The molecular trigger mediating the metabolic shift and the functional consequences is activation of AMP-activated protein kinase (AMPK. Taken together, our results indicate that monocytes are sufficiently metabolically flexible to perform pro-inflammatory functions at sites of inflammation despite glucose deprivation and inhibition of the LPS-induced Warburg effect. AMPK seems to play a pivotal role in orchestrating these processes during glucose deprivation in monocytes.

Anti-Inflammatory Effect of Melittin on Porphyromonas Gingivalis LPS-Stimulated Human Keratinocytes.

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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.

Associations of Escherichia coli K-12 OmpF trimers with rough and smooth lipopolysaccharides

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Diedrich, D.L.; Stein, M.A.; Schnaitman, C.A.

1990-01-01

The associations of both rough and smooth lipopolysaccharides (LPS) with the OmpF porin of Escherichia coli K-12 were examined in galE strains deleted for ompC. Transformation with pSS37 and growth with galactose conferred the ability to assemble a Shigella dysenteriae O antigen onto the core oligosaccharide of E. coli K-12 LPS. The association of LPS with OmpF trimers was assessed by staining, autoradiography of LPS specifically labeled with [1-14C]galactose, and Western immunoblotting with a monoclonal antibody specific for OmpF trimers. These techniques revealed that the migration distances and multiple banding patterns of OmpF porin trimers in sodium dodecyl sulfate-polyacrylamide gels were dictated by the chemotype of associated LPS. Expression of smooth LPS caused almost all of the trimeric OmpF to run in gels with a slower mobility than trimers from rough strains. The LPS associated with trimers from a smooth strain differed from the bulk-phase LPS by consisting almost exclusively of molecules with O antigen

Piracetam Attenuates LPS-Induced Neuroinflammation and Cognitive Impairment in Rats.

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Tripathi, Alok; Paliwal, Pankaj; Krishnamurthy, Sairam

2017-11-01

The present study was performed to investigate the effect of piracetam on neuroinflammation induced by lipopolysaccharide (LPS) and resulting changes in cognitive behavior. Neuroinflammation was induced by a single dose of LPS solution infused into each of the lateral cerebral ventricles in concentrations of 1 μg/μl, at a rate of 1 μl/min over a 5-min period, with a 5-min waiting period between the two infusions. Piracetam in doses of 50, 100, and 200 mg/kg i.p. was administered 30 min before LPS infusion and continued for 9 days. On ninth day, the behavioral test for memory and anxiety was done followed by blood collection and microdissection of the hippocampus (HIP) and prefrontal cortex brain regions. Piracetam attenuated the LPS-induced decrease in coping strategy to novel environment indicating anxiolytic activity. It also reversed the LPS-induced changes in the known arm and novel arm entries in the Y-maze test indicating amelioration of spatial memory impairment. Further, piracetam moderated LPS-induced decrease in the mitochondrial complex enzyme activities (I, II, IV, and V) and mitochondrial membrane potential. It ameliorated changes in hippocampal lipid peroxidation and nitrite levels including the activity of superoxide dismutase. Piracetam region specifically ameliorated LPS-induced increase in the level of IL-6 in HIP indicating anti-neuroinflammatory effect. Further, piracetam reduced HIP Aβ (1-40) and increased blood Aβ level suggesting efflux of Aβ from HIP to blood. Therefore, the present study indicates preclinical evidence for the use of piracetam in the treatment of neuroinflammatory disorders.

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.

SOX6 and PDCD4 enhance cardiomyocyte apoptosis through LPS-induced miR-499 inhibition.

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Jia, Zhuqing; Wang, Jiaji; Shi, Qiong; Liu, Siyu; Wang, Weiping; Tian, Yuyao; Lu, Qin; Chen, Ping; Ma, Kangtao; Zhou, Chunyan

2016-02-01

Sepsis-induced cardiac apoptosis is one of the major pathogenic factors in myocardial dysfunction. As it enhances numerous proinflammatory factors, lipopolysaccharide (LPS) is considered the principal mediator in this pathological process. However, the detailed mechanisms involved are unclear. In this study, we attempted to explore the mechanisms involved in LPS-induced cardiomyocyte apoptosis. We found that LPS stimulation inhibited microRNA (miR)-499 expression and thereby upregulated the expression of SOX6 and PDCD4 in neonatal rat cardiomyocytes. We demonstrate that SOX6 and PDCD4 are target genes of miR-499, and they enhance LPS-induced cardiomyocyte apoptosis by activating the BCL-2 family pathway. The apoptosis process enhanced by overexpression of SOX6 or PDCD4, was rescued by the cardiac-abundant miR-499. Overexpression of miR-499 protected the cardiomyocytes against LPS-induced apoptosis. In brief, our results demonstrate the existence of a miR-499-SOX6/PDCD4-BCL-2 family pathway in cardiomyocytes in response to LPS stimulation.

Exogenous normal lymph reduces liver injury induced by lipopolysaccharides in rats

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Zhao, Z.G.; Zhang, L.L.; Niu, C.Y.; Zhang, J.

2014-01-01

The liver is one of the target organs damaged by septic shock, wherein the spread of endotoxins begins. This study aimed to investigate the effects of exogenous normal lymph (ENL) on lipopolysaccharide (LPS)-induced liver injury in rats. Male Wistar rats were randomly divided into sham, LPS, and LPS+ENL groups. LPS (15 mg/kg) was administered intravenously via the left jugular vein to the LPS and LPS+ENL groups. At 15 min after the LPS injection, saline or ENL without cell components (5 mL/kg) was administered to the LPS and LPS+ENL groups, respectively, at a rate of 0.5 mL/min. Hepatocellular injury indices and hepatic histomorphology, as well as levels of P-selectin, intercellular adhesion molecule 1 (ICAM-1), myeloperoxidase (MPO), and Na + -K + -ATPase, were assessed in hepatic tissues. Liver tissue damage occurred after LPS injection. All levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma as well as the wet/dry weight ratio of hepatic tissue in plasma increased. Similarly, P-selectin, ICAM-1, and MPO levels in hepatic tissues were elevated, whereas Na + -K + -ATPase activity in hepatocytes decreased. ENL treatment lessened hepatic tissue damage and decreased levels of AST, ALT, ICAM-1, and MPO. Meanwhile, the treatment increased the activity of Na + -K + -ATPase. These results indicated that ENL could alleviate LPS-induced liver injury, thereby suggesting an alternative therapeutic strategy for the treatment of liver injury accompanied by severe infection or sepsis

Direct effects of locally administered lipopolysaccharide on glucose, lipid, and protein metabolism in the placebo-controlled, bilaterally infused human leg

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Buhl, Mads; Bosnjak, Ermina; Vendelbo, Mikkel H.

2013-01-01

Context: Accumulating evidence suggests that chronic exposure to lipopolysaccharide (LPS, endotoxin) maycreate a constant low-grade inflammation, leading to insulin resistance and diabetes. All previous human studies assessing the metabolic actions of LPS have used systemic administration, making...... palmitate isotopic dilution, although primary ANOVA tests did not reveal significant dilution. Leg blood flows, phenylalanine, lactate kinetics, cytokines, and intramyocellular insulin signaling were not affected by LPS. LPS thus directly inhibits insulin-stimulated glucose uptake and increases palmitate...... and stress hormone release may lead to overt glucose intolerance and diabetes....

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

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Wang, Yuli; Wu, Hongxia; Shen, Ming; Ding, Siyang; Miao, Jing; Chen, Ning

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.

Tanshinone IIA Sodium Sulfonate Attenuates LPS-Induced Intestinal Injury in Mice

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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.

Prevention of LPS-Induced Acute Lung Injury in Mice by Progranulin

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Zhongliang Guo

2012-01-01

Full Text Available The acute respiratory distress syndrome (ARDS, a clinical complication of severe acute lung injury (ALI in humans, is a leading cause of morbidity and mortality in critically ill patients. Despite decades of research, few therapeutic strategies for clinical ARDS have emerged. Here we carefully evaluated the effect of progranulin (PGRN in treatment of ARDS using the murine model of lipopolysaccharide (LPS-induced ALI. We reported that administration of PGRN maintained the body weight and survival of ALI mice. We revealed that administration of PGRN significantly reduced LPS-induced pulmonary inflammation, as reflected by reductions in total cell and neutrophil counts, proinflammatory cytokines, as well as chemokines in bronchoalveolar lavage (BAL fluid. Furthermore, administration of PGRN resulted in remarkable reversal of LPS-induced increases in lung permeability as assessed by reductions in total protein, albumin, and IgM in BAL fluid. Consistently, we revealed a significant reduction of histopathology changes of lung in mice received PGRN treatment. Finally, we showed that PGRN/TNFR2 interaction was crucial for the protective effect of PGRN on the LPS-induced ALI. Our findings strongly demonstrated that PGRN could effectively ameliorate the LPS-induced ALI in mice, suggesting a potential application for PGRN-based therapy to treat clinical ARDS.

Minocycline protects against lipopolysaccharide-induced cognitive impairment in mice.

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Hou, Yue; Xie, Guanbo; Liu, Xia; Li, Guoxun; Jia, Congcong; Xu, Jinghua; Wang, Bing

2016-03-01

The role of glial cells, especially microglia and astrocytes, in neuroinflammation and cognition has been studied intensively. Lipopolysaccharide (LPS), a commonly used inducer of neuroinflammation, can cause cognitive impairment. Minocycline is known to possess potent neuroprotective activity, but its effect on LPS-induced cognitive impairment is unknown. This study aims to investigate the effects of minocycline on LPS-induced cognitive impairment and glial cell activation in mice. Behavioral tests were conducted for cognitive function, immunohistochemistry for microglial and astrocyte response, and quantitative PCR for mRNA expression of proinflammatory cytokines. Minocycline significantly reversed the decreased spontaneous alternation induced by intrahippocampal administration of LPS in the Y-maze task. In the Morris water maze place navigation test, minocycline decreased the escape latency and distance traveled compared to LPS-treated mice. In the probe test, minocycline-treated mice spent more time in the target quadrant and crossed the platform area more frequently than animals in the LPS-treated group. Minocycline produced a significant decrease in the number of Iba-1- and GFAP-positive hippocampal cells compared to the LPS-treated group. Minocycline-treated mice had significantly reduced hippocampal TNF-α and IL-1β mRNA levels compared with LPS-treated animals. Minocycline caused a significant increase in hippocampal BDNF expression compared to the LPS-treated group. Minocycline can attenuate LPS-induced cognitive impairments in mice. This effect may be associated with its action to suppress the activation of microglia and astrocytes and to normalize BDNF expression. Since neuroinflammatory processes and cognitive impairments are implicated in neurodegenerative disorders, minocycline may be a promising candidate for treating such diseases.

Hydrogel-embedded endothelial progenitor cells evade LPS and mitigate endotoxemia.

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Ghaly, Tammer; Rabadi, May M; Weber, Mia; Rabadi, Seham M; Bank, Michael; Grom, John M; Fallon, John T; Goligorsky, Michael S; Ratliff, Brian B

2011-10-01

Sepsis and its complications are associated with poor clinical outcomes. The circulatory system is a well-known target of lipopolysaccharide (LPS). Recently, several clinical studies documented mobilization of endothelial progenitor cells (EPCs) during endotoxemia, with the probability of patients' survival correlating with the rise in circulating EPCs. This fact combined with endotoxemia-induced vascular injury led us to hypothesize that the developing functional EPC incompetence could impede vascular repair and that adoptive transfer of EPCs could improve hemodynamics in endotoxemia. We used LPS injection to model endotoxemia. EPCs isolated from endotoxemic mice exhibited impaired clonogenic potential and LPS exerted Toll-like receptor 4-mediated cytotoxic effects toward EPCs, which was mitigated by embedding them in hyaluronic acid (HA) hydrogels. Therefore, intact EPCs were either delivered intravenously or embedded within pronectin-coated HA hydrogels. Adoptive transfer of EPCs in LPS-injected mice improved control of blood pressure and reduced hepatocellular and renal dysfunction. Specifically, EPC treatment was associated with the restoration of renal microcirculation and improved renal function. EPC therapy was most efficient when cells were delivered embedded in HA hydrogel. These findings establish major therapeutic benefits of adoptive transfer of EPCs, especially when embedded in HA hydrogels, in mice with LPS-induced endotoxemia, and they argue that hemodynamic and renal abnormalities of endotoxemia are in significant part due to developing incompetence of endogenous EPCs.

Impact of training status on LPS-induced acute inflammation in humans

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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......) healthy male subjects were included in the study with eight subjects assigned to a trained (T) group and nine subjects assigned to an untrained (UT) group. On the experimental day, catheters were inserted in the femoral artery and vein of one leg for blood sampling and a bolus of 0.3 ng LPS•kg-1 body...... weight was injected into an antecubital vein in the forearm. Femoral arterial blood flow was measured before (Pre) the LPS injection and continuously throughout the experiment by Ultrasound Doppler and arterial and venous blood samples were drawn Pre and 30, 60, 90 and 120 min after the LPS injection...

Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

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Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

2018-01-15

To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

Pseudane-VII Isolated from Pseudoalteromonas sp. M2 Ameliorates LPS-Induced Inflammatory Response In Vitro and In Vivo

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Mi Eun Kim

2017-11-01

Full Text Available The ocean is a rich resource of flora, fauna, food, and biological products. We found a wild-type bacterial strain, Pseudoalteromonas sp. M2, from marine water and isolated various secondary metabolites. Pseudane-VII is a compound isolated from the Pseudoalteromonas sp. M2 metabolite that possesses anti-melanogenic activity. Inflammation is a response of the innate immune system to microbial infections. Macrophages have a critical role in fighting microbial infections and inflammation. Recent studies reported that various compounds derived from natural products can regulate immune responses including inflammation. However, the anti-inflammatory effects and mechanism of pseudane-VII in macrophages are still unknown. In this study, we investigated the anti-inflammatory effects of pseudane-VII. In present study, lipopolysaccharide (LPS-induced nitric oxide (NO production was significantly decreased by pseudane-VII treatment at 6 μM. Moreover, pseudane-VII treatment dose-dependently reduced mRNA levels of pro-inflammatory cytokines including inos, cox-2, il-1β, tnf-α, and il-6 in LPS-stimulated macrophages. Pseudane-VII also diminished iNOS protein levels and IL-1β secretion. In addition, Pseudane-VII elicited anti-inflammatory effects by inhibiting ERK, JNK, p38, and nuclear factor (NF-κB-p65 phosphorylation. Consistently, pseudane-VII was also shown to inhibit the LPS-stimulated release of IL-1β and expression of iNOS in mice. These results suggest that pseudane-VII exerted anti-inflammatory effects on LPS-stimulated macrophage activation via inhibition of ERK, JNK, p38 MAPK phosphorylation, and pro-inflammatory gene expression. These findings may provide new approaches in the effort to develop anti-inflammatory therapeutics.

Pseudane-VII Isolated from Pseudoalteromonas sp. M2 Ameliorates LPS-Induced Inflammatory Response In Vitro and In Vivo.

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Kim, Mi Eun; Jung, Inae; Lee, Jong Suk; Na, Ju Yong; Kim, Woo Jung; Kim, Young-Ok; Park, Yong-Duk; Lee, Jun Sik

2017-11-01

The ocean is a rich resource of flora, fauna, food, and biological products. We found a wild-type bacterial strain, Pseudoalteromonas sp. M2, from marine water and isolated various secondary metabolites. Pseudane-VII is a compound isolated from the Pseudoalteromonas sp. M2 metabolite that possesses anti-melanogenic activity. Inflammation is a response of the innate immune system to microbial infections. Macrophages have a critical role in fighting microbial infections and inflammation. Recent studies reported that various compounds derived from natural products can regulate immune responses including inflammation. However, the anti-inflammatory effects and mechanism of pseudane-VII in macrophages are still unknown. In this study, we investigated the anti-inflammatory effects of pseudane-VII. In present study, lipopolysaccharide (LPS)-induced nitric oxide (NO) production was significantly decreased by pseudane-VII treatment at 6 μM. Moreover, pseudane-VII treatment dose-dependently reduced mRNA levels of pro-inflammatory cytokines including inos , cox-2 , il-1β , tnf-α , and il-6 in LPS-stimulated macrophages. Pseudane-VII also diminished iNOS protein levels and IL-1β secretion. In addition, Pseudane-VII elicited anti-inflammatory effects by inhibiting ERK, JNK, p38, and nuclear factor (NF)-κB-p65 phosphorylation. Consistently, pseudane-VII was also shown to inhibit the LPS-stimulated release of IL-1β and expression of iNOS in mice. These results suggest that pseudane-VII exerted anti-inflammatory effects on LPS-stimulated macrophage activation via inhibition of ERK, JNK, p38 MAPK phosphorylation, and pro-inflammatory gene expression. These findings may provide new approaches in the effort to develop anti-inflammatory therapeutics.

Chondroitin Sulfate-Rich Extract of Skate Cartilage Attenuates Lipopolysaccharide-Induced Liver Damage in Mice.

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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

2017-06-15

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.

LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

International Nuclear Information System (INIS)

Russe, Otto Quintus; Möser, Christine V.; Kynast, Katharina L.; King, Tanya S.; Olbrich, Katrin; Grösch, Sabine; Geisslinger, Gerd; Niederberger, Ellen

2014-01-01

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

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.

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

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

The anti-inflammatory effect of TR6 on LPS-induced mastitis in mice.

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Hu, Xiaoyu; Fu, Yunhe; Tian, Yuan; Zhang, Zecai; Zhang, Wenlong; Gao, Xuejiao; Lu, Xiaojie; Cao, Yongguo; Zhang, Naisheng

2016-01-01

[TRIAP]-derived decoy peptides have anti-inflammatory properties. In this study, we synthesized a TRIAP-derived decoy peptide (TR6) containing, the N-terminal portion of the third helical region of the [TIRAP] TIR domain (sequence "N"-RQIKIWFQNRRMKWK and -KPGFLRDPWCKYQML-"C"). We evaluated the effects of TR6 on lipopolysaccharide-induced mastitis in mice. In vivo, the mastitis model was induced by LPS administration for 24h, and TR6 treatment was initiated 1h before or after induction of LPS. In vitro, primary mouse mammary epithelial cells and neutrophils were used to investigate the effects of TR6 on LPS-induced inflammatory responses. The results showed that TR6 significantly inhibited mammary gland hisopathologic changes, MPO activity, and LPS-induced production of TNF-α, IL-1β and IL-6. In vitro, TR6 significantly inhibited LPS-induced TNF-α and IL-6 production and phosphorylation of NF-κB and MAPKs. In conclusion, this study demonstrated that the anti-inflammatory effect of TR6 against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB and MAPK signaling pathways. TR6 may be a promising therapeutic reagent for mastitis treatment. Copyright © 2015. Published by Elsevier B.V.

Exogenous normal lymph reduces liver injury induced by lipopolysaccharides in rats

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Z.G. Zhao

2014-02-01

Full Text Available The liver is one of the target organs damaged by septic shock, wherein the spread of endotoxins begins. This study aimed to investigate the effects of exogenous normal lymph (ENL on lipopolysaccharide (LPS-induced liver injury in rats. Male Wistar rats were randomly divided into sham, LPS, and LPS+ENL groups. LPS (15 mg/kg was administered intravenously via the left jugular vein to the LPS and LPS+ENL groups. At 15 min after the LPS injection, saline or ENL without cell components (5 mL/kg was administered to the LPS and LPS+ENL groups, respectively, at a rate of 0.5 mL/min. Hepatocellular injury indices and hepatic histomorphology, as well as levels of P-selectin, intercellular adhesion molecule 1 (ICAM-1, myeloperoxidase (MPO, and Na+-K+-ATPase, were assessed in hepatic tissues. Liver tissue damage occurred after LPS injection. All levels of alanine aminotransferase (ALT and aspartate aminotransferase (AST in plasma as well as the wet/dry weight ratio of hepatic tissue in plasma increased. Similarly, P-selectin, ICAM-1, and MPO levels in hepatic tissues were elevated, whereas Na+-K+-ATPase activity in hepatocytes decreased. ENL treatment lessened hepatic tissue damage and decreased levels of AST, ALT, ICAM-1, and MPO. Meanwhile, the treatment increased the activity of Na+-K+-ATPase. These results indicated that ENL could alleviate LPS-induced liver injury, thereby suggesting an alternative therapeutic strategy for the treatment of liver injury accompanied by severe infection or sepsis.

Exogenous normal lymph reduces liver injury induced by lipopolysaccharides in rats

Energy Technology Data Exchange (ETDEWEB)

Zhao, Z.G.; Zhang, L.L.; Niu, C.Y.; Zhang, J. [Institute of Microcirculation, Hebei North University, Zhangjiakou, China, Institute of Microcirculation, Hebei North University, Zhangjiakou, Hebei (China)

2014-02-17

The liver is one of the target organs damaged by septic shock, wherein the spread of endotoxins begins. This study aimed to investigate the effects of exogenous normal lymph (ENL) on lipopolysaccharide (LPS)-induced liver injury in rats. Male Wistar rats were randomly divided into sham, LPS, and LPS+ENL groups. LPS (15 mg/kg) was administered intravenously via the left jugular vein to the LPS and LPS+ENL groups. At 15 min after the LPS injection, saline or ENL without cell components (5 mL/kg) was administered to the LPS and LPS+ENL groups, respectively, at a rate of 0.5 mL/min. Hepatocellular injury indices and hepatic histomorphology, as well as levels of P-selectin, intercellular adhesion molecule 1 (ICAM-1), myeloperoxidase (MPO), and Na{sup +}-K{sup +}-ATPase, were assessed in hepatic tissues. Liver tissue damage occurred after LPS injection. All levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma as well as the wet/dry weight ratio of hepatic tissue in plasma increased. Similarly, P-selectin, ICAM-1, and MPO levels in hepatic tissues were elevated, whereas Na{sup +}-K{sup +}-ATPase activity in hepatocytes decreased. ENL treatment lessened hepatic tissue damage and decreased levels of AST, ALT, ICAM-1, and MPO. Meanwhile, the treatment increased the activity of Na{sup +}-K{sup +}-ATPase. These results indicated that ENL could alleviate LPS-induced liver injury, thereby suggesting an alternative therapeutic strategy for the treatment of liver injury accompanied by severe infection or sepsis.

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

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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.

Lipopolysaccharide modulation of a CD14-like molecule on porcine alveolar macrophages

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Kielian, T. L.; Ross, C. R.; McVey, D. S.; Chapes, S. K.; Blecha, F.; Spooner, B. S. (Principal Investigator)

1995-01-01

Cluster of differentiation antigen 14 (CD14) functions as a receptor for lipopolysaccharide (LPS) LPS-binding protein (LBP) complexes. Because LPS has varying effects on CD14 expression in vitro, we evaluated CD14 expression in response to LPS with a fully differentiated macrophage phenotype, the alveolar macrophage. By using flow microfluorometric analysis and a radioimmunoassay with an anti-human CD14 monoclonal antibody (My4) that cross-reacts with porcine CD14, we found that macrophages stimulated with LPS for 24 h exhibited a two- to fivefold increase in CD14-like antigen compared with unstimulated cells. At low concentrations of LPS, up-regulation of the CD14-like antigen was dependent on serum; at higher concentrations of LPS, serum was not required. In the absence of serum a 10-fold higher dose of LPS (10 ng/ml) was required to increase CD14-like expression. In addition, LPS-induced CD14-like up-regulation correlated with secretion of tumor necrosis factor-alpha, regardless of serum concentration. Blockade with My4 antibody significantly inhibited LPS-induced tumor necrosis factor-alpha secretion at 1 ng/ml of LPS. However, inhibition decreased as we increased the LPS concentration, suggesting the existence of CD14-independent pathways of macrophage activation in response to LPS. Alternatively, My4 may have a lower affinity for the porcine CD14 antigen than LPS, which may have only partially blocked the LPS-LBP binding site at high concentrations of LPS. Therefore, these data suggest that LPS activation of porcine alveolar macrophages for 24 h increased CD14-like receptor expression. The degree of CD14-like up-regulation was related to LPS concentration, however, activation did not require the presence of serum at high concentrations of LPS.

Sildenafil (Viagra(®)) prevents and restores LPS-induced inflammation in astrocytes.

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de Santana Nunes, Ana Karolina; Rapôso, Catarina; Björklund, Ulrika; da Cruz-Höfling, Maria Alice; Peixoto, Christina Alves; Hansson, Elisabeth

2016-09-06

Astrocytes are effectively involved in the pathophysiological processes in the central nervous system (CNS) and may contribute to or protect against development of inflammatory and degenerative diseases. Sildenafil is a potent and selective phosphodiesterase-5 (PDE-5) inhibitor, which induces cyclic GMP accumulation. However, the mechanisms of actions on glial cells are not clear. The aim of the present work is to evaluate the role of sildenafil in lipopolysaccharide (LPS)-stimulated astrocytes. The cytoskeleton integrity and Ca(2+) waves were assessed as indicators of inflammatory state. Two main groups were done: (A) one prevention and (B) one restoration. Each of these groups: A1: control; A2: LPS for 24h; A3: sildenafil 1 or 10μM for 4h and then sildenafil 1 or 10μM+LPS for 24h. B1: control; B2: LPS for 24h; B3: LPS for 24h and then LPS+sildenafil 1 or 10μM for 24h. Cytoskeleton integrity was analyzed through GFAP immunolabeling and actin labeling with an Alexa 488-conjugated phalloidin probe. Calcium responses were assessed through a Ca(2+)-sensitive fluorophore Fura-2/AM. The results show that both preventive and restorative treatments with sildenafil (in both concentrations) reduced the Ca(2+) responses in intensity and induced a more organized actin fiber pattern, compared to LPS treated cells. This work demonstrated for the first time that astrocytes are a key part of the sildenafil protective effects in the CNS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Relationship between luminous fish and symbiosis. I. Comparative studies of lipopolysaccharides isolated from symbiotic luminous bacteria of the luminous marine fish, Physiculus japonicus.

Science.gov (United States)

Kuwae, T; Andoh, M; Fukasawa, S; Kurata, M

1983-01-01

In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically. Five symbiotic luminous bacteria (PJ strains) were separately isolated from five individuals of this fish species caught at three points, off the coasts of Chiba, Nakaminato, and Oharai. LPS preparations were made from these bacteria by Westphal's phenol-water method and highly purified by repeated ultracentrifugation. These LPSs contained little or no 2-keto-3-deoxyoctonate and had powerful mitogenic activity. In sodium dodecylsulfate polyacrylamide gel electrophoresis, these PJ-1 to -5 LPSs were separated by their electrophoretic patterns into three groups; the first group included PJ-1 and PJ-4, the second group PJ-2 and PJ-3, and the third group PJ-5 alone. The results agreed with those of the double immunodiffusion test; precipitin lines completely coalesced within each group but not with other groups. In immunoelectrophoresis, one precipitin line was observed between anti PJ-2 LPS serum and PJ-5 LPS but the electrophoretic mobility of PJ-5 LPS was clearly different from that of the PJ-2 LPS group. Furthermore, in a 50% inhibition test with PJ-2 LPS by the passive hemolysis system, the doses of PJ-2 LPS, PJ-3 LPS, and PJ-5 LPS required for 50% inhibition (ID50) in this system were 0.25, 0.25, and 21.6 micrograms/ml for each alkali-treated LPS, respectively, and the ID50's of both PJ-1 LPS and PJ-4 LPS were above 1,000 micrograms/ml. These results indicate that PJ-5 LPS has an antigenic determinant partially in common with LPS from the PJ-2 group but not with LPS from the PJ-1 group and that the symbiotic luminous bacterium PJ-5 is more closely related to the PJ-2 group than to the PJ-1 group. These results show that the species Physiculus japonicus is symbiotically associated with at least three immunologically different

Evolutionary conservation of the lipopolysaccharide binding site of β₂-glycoprotein I

NARCIS (Netherlands)

Ağar, Çetin; de Groot, Philip G.; Marquart, J. Arnoud; Meijers, Joost C. M.

2011-01-01

β₂-Glycoprotein I (β₂GPI) is a highly abundant plasma protein and the major antigen for autoantibodies in the antiphospholipid syndrome. Recently, we have described a novel function of β₂GPI as scavenger of lipopolysaccharide (LPS). With this in mind we investigated the conservation of β₂GPI in

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.

Prenatal exposure to lipopolysaccharide combined with pre- and postnatal high-fat diet result in lowered blood pressure and insulin resistance in offspring rats.

Science.gov (United States)

Hao, Xue-Qin; Du, Jing-Xia; Li, Yan; Li, Meng; Zhang, Shou-Yan

2014-01-01

Adult metabolic syndrome may in part have origins in fetal or early life. This study was designed to explore the effect of prenatal exposure to lipopolysaccharide and high-fat diet on metabolic syndrome in offspring rats. 32 pregnant rats were randomly divided into four groups, including Control group; LPS group (pregnant rats were injected with LPS 0.4 mg/kg intraperitoneally on the 8(th), 10(th) and 12(th) day of pregnancy); High-fat group (maternal rats had high-fat diet during pregnancy and lactation period, and their pups also had high-fat diet up to the third month of life); LPS + High-fat group (rats were exposed to the identical experimental scheme with LPS group and High-fat group). Blood pressure elevated in LPS group and High-fat group, reduced in LPS+High-fat group, accompanied by the increase of serum leptin level in LPS and High-fat group and increase of serum IL-6, TNF-a in High-fat group; both serum insulin and cholesterol increased in High-fat and LPS+High-fat group, as well as insulin in LPS group. HOMA-IR value increased in LPS, High-fat and LPS+High-fat group, and QUICKI decreased in these groups; H-E staining showed morphologically pathological changes in thoracic aorta and liver tissue in the three groups. Increased serum alanine and aspartate aminotransferase suggest impaired liver function in LPS+High-fat group. Prenatal exposure to lipopolysaccharide combined with pre- and postnatal high-fat diet result in lowered blood pressure, insulin resistance and impaired liver function in three-month old offspring rats. The lowered blood pressure might benefit from the predictive adaptive response to prenatal inflammation.

Adaptive Redox Response of Mesenchymal Stromal Cells to Stimulation with Lipopolysaccharide Inflammagen: Mechanisms of Remodeling of Tissue Barriers in Sepsis

Directory of Open Access Journals (Sweden)

Nikolai V. Gorbunov

2013-01-01

Full Text Available Acute bacterial inflammation is accompanied by excessive release of bacterial toxins and production of reactive oxygen and nitrogen species (ROS and RNS, which ultimately results in redox stress. These factors can induce damage to components of tissue barriers, including damage to ubiquitous mesenchymal stromal cells (MSCs, and thus can exacerbate the septic multiple organ dysfunctions. The mechanisms employed by MSCs in order to survive these stress conditions are still poorly understood and require clarification. In this report, we demonstrated that in vitro treatment of MSCs with lipopolysaccharide (LPS induced inflammatory responses, which included, but not limited to, upregulation of iNOS and release of RNS and ROS. These events triggered in MSCs a cascade of responses driving adaptive remodeling and resistance to a “self-inflicted” oxidative stress. Thus, while MSCs displayed high levels of constitutively present adaptogens, for example, HSP70 and mitochondrial Sirt3, treatment with LPS induced a number of adaptive responses that included induction and nuclear translocation of redox response elements such as NFkB, TRX1, Ref1, Nrf2, FoxO3a, HO1, and activation of autophagy and mitochondrial remodeling. We propose that the above prosurvival pathways activated in MSCs in vitro could be a part of adaptive responses employed by stromal cells under septic conditions.

Identification of Residues in the Lipopolysaccharide ABC Transporter That Coordinate ATPase Activity with Extractor Function.

Science.gov (United States)

Simpson, Brent W; Owens, Tristan W; Orabella, Matthew J; Davis, Rebecca M; May, Janine M; Trauger, Sunia A; Kahne, Daniel; Ruiz, Natividad

2016-10-18

The surface of most Gram-negative bacteria is covered with lipopolysaccharide (LPS), creating a permeability barrier against toxic molecules, including many antimicrobials. To assemble LPS on their surface, Gram-negative bacteria must extract newly synthesized LPS from the inner membrane, transport it across the aqueous periplasm, and translocate it across the outer membrane. The LptA to -G proteins assemble into a transenvelope complex that transports LPS from the inner membrane to the cell surface. The Lpt system powers LPS transport from the inner membrane by using a poorly characterized ATP-binding cassette system composed of the ATPase LptB and the transmembrane domains LptFG. Here, we characterize a cluster of residues in the groove region of LptB that is important for controlling LPS transport. We also provide the first functional characterization of LptFG and identify their coupling helices that interact with the LptB groove. Substitutions at conserved residues in these coupling helices compromise both the assembly and function of the LptB 2 FG complex. Defects in LPS transport conferred by alterations in the LptFG coupling helices can be rescued by changing a residue in LptB that is adjacent to functionally important residues in the groove region. This suppression is achieved by increasing the ATPase activity of the LptB 2 FG complex. Taken together, these data identify a specific binding site in LptB for the coupling helices of LptFG that is responsible for coupling of ATP hydrolysis by LptB with LptFG function to achieve LPS extraction. Lipopolysaccharide (LPS) is synthesized at the cytoplasmic membrane of Gram-negative bacteria and transported across several compartments to the cell surface, where it forms a barrier that protects these organisms from antibiotics. The LptB 2 FG proteins form an ATP-binding cassette (ABC) transporter that uses energy from ATP hydrolysis in the cytoplasm to facilitate extraction of LPS from the outer face of the

The Structural Basis for Lipid and Endotoxin Binding in RP105-MD-1, and Consequences for Regulation of Host Lipopolysaccharide Sensitivity.

Science.gov (United States)

Ortiz-Suarez, Maite L; Bond, Peter J

2016-01-05

MD-1 is a member of the MD-2-related lipid-recognition (ML) family, and associates with RP105, a cell-surface protein that resembles Toll-like receptor 4 (TLR4). The RP105⋅MD-1 complex has been proposed to play a role in fine-tuning the innate immune response to endotoxin such as bacterial lipopolysaccharide (LPS) via TLR4⋅MD-2, but controversy surrounds its mechanism. We have used atomically detailed simulations to reveal the structural basis for ligand binding and consequent functional dynamics of MD-1 and the RP105 complex. We rationalize reports of endogenous phospholipid binding, by showing that they prevent collapse of the malleable MD-1 fold, before refining crystallographic models and uncovering likely binding modes for LPS analogs. Subsequent binding affinity calculations reveal that endotoxin specificity arises from the entropic cost of expanding the MD-1 cavity to accommodate bulky lipid tails, and support the role of MD-1 as a "sink" that sequesters endotoxin from TLR4 and stabilizes RP105/TLR4 interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

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....

Endocannabinergic modulation of interleukin-1β in mouse hippocampus under basal conditions and after in vivo systemic lipopolysaccharide stimulation.

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Csölle, Cecília; Sperlágh, Beáta

2011-01-01

Cannabinoids play an important role in the suppression of proinflammatory cytokine production in the periphery and brain. In this study, we explored whether endogenous activation of cannabinoid (CB) 1 receptors (CB1Rs) affects interleukin (IL)-1β levels in the mouse hippocampus under basal conditions and following stimulation with in vivo bacterial lipopolysaccharide (LPS, 250 μg/kg i.p.). IL-1β levels were determined in the hippocampi of wild-type (WT), CB1R-/- and P2X₇ receptor (P2X₇R)-/- mice using an ELISA kit. Basal but not LPS-induced IL-1β levels were downregulated when CB1R function was abrogated by genetic deletion, suggesting that endocannabinoids contributed to basal IL-1β content in the mouse hippocampus. AM251 (3 mg/kg i.p.), an antagonist of CB1Rs, also inhibited basal IL-1β protein in WT but not in CB1R-/- mice. In the absence of P2X₇R, LPS-induced IL-1β production was lower, while the inhibitory effect of CB1R antagonists on basal IL-1β was significantly attenuated. The LPS-induced elevation in IL-1β production was decreased in the presence of AM251 and AM281, with no significant difference between WT and P2X₇R-/- mice. CB1Rs are responsible for the modulation of basal IL-1β levels in the hippocampus, while the effects of CB1 antagonists on systemic LPS-induced IL-1β concentrations are independent of CB1Rs. Copyright © 2011 S. Karger AG, Basel.

IL-8 and MCP Gene Expression and Production by LPS-Stimulated Human Corneal Stromal Cells

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Roni M. Shtein

2012-01-01

Full Text Available Purpose. To determine time course of effect of lipopolysaccharide (LPS on production of interleukin-8 (IL-8 and monocyte chemotactic protein (MCP by cultured human corneal stromal cells. Methods. Human corneal stromal cells were harvested from donor corneal specimens, and fourth to sixth passaged cells were used. Cell cultures were stimulated with LPS for 2, 4, 8, and 24 hours. Northern blot analysis of IL-8 and MCP gene expression and ELISA for IL-8 and MCP secretion were performed. ELISA results were analyzed for statistical significance using two-tailed Student's t-test. Results. Northern blot analysis demonstrated significantly increased IL-8 and MCP gene expression after 4 and 8 hours of exposure to LPS. ELISA for secreted IL-8 and MCP demonstrated statistically significant increases (P<0.05 after corneal stromal cell stimulation with LPS. Conclusions. This paper suggests that human corneal stromal cells may participate in corneal inflammation by secreting potent leukocyte chemotactic and activating proteins in a time-dependent manner when exposed to LPS.

Immunobiological, biochemical, and physico-chemical characteristics of Brucella lipopolysaccharide subjected to various doses of gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Dranovskaya, E A; Shibaeva, I V [Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Ehpidemiologii i Mikrobiologii; Khabakpasheva, N A; Rostovtseva, N A [Institut Vaktsin i Syvorotok, Moscow (USSR)

1975-01-01

A comparative study is presented of toxicity, serological activity, some biochemical and physico-chemical properties of the highly toxic Brucella lipopolysaccharide (LPS) and of preparations obtained as a result of gamma irradiation in doses of 1, 3, and 10 mrad on the antigen. The toxicity of LPS was found to decrease with increasing radiation dose. Irradiation with a dose of 3 mrad produced a marked decrease in the toxicity of the antigen without essentially changing its serological properties. The process of LPS detoxication under the effect of irradiation was accompanied by changes in certain biochemical and physico-chemical indices suggestive of a modification of the primary structure of the LPS molecule and of an impairment especially of its polysaccharide side chains.

Immunobiological, biochemical and physico-chemical characteristics of Brucella lipopolysaccharide subjected to various doses of gamma radiation

International Nuclear Information System (INIS)

Dranovskaya, E.A.; Shibaeva, I.V.

1975-01-01

A comparative study is presented of toxicity, serological activity, some biochemical and physico-chemical properties of the highly toxic Brucella lipopolysaccharide (LPS) and of preparations obtained as a result of gamma irradiation in doses of 1, 3, and 10 mrad on the antigen. The toxicity of LPS was found to decrease with increasing radiation dose. Irradiation with a dose of 3 mrad produced a marked decrease in the toxicity of the antigen without essentially changing its serological properties. The process of LPS detoxication under the effect of irradiation was accompanied by changes in certain biochemical and physico-chemical indices suggestive of a modification of the primary structure of the LPS molecule and of an impairment especially of its polysaccharide side chains. (author)

Designed beta-boomerang antiendotoxic and antimicrobial peptides: structures and activities in lipopolysaccharide.

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Bhunia, Anirban; Mohanram, Harini; Domadia, Prerna N; Torres, Jaume; Bhattacharjya, Surajit

2009-08-14

Lipopolysaccharide (LPS), an integral part of the outer membrane of Gram-negative bacteria, is involved in a variety of biological processes including inflammation, septic shock, and resistance to host-defense molecules. LPS also provides an environment for folding of outer membrane proteins. In this work, we describe the structure-activity correlation of a series of 12-residue peptides in LPS. NMR structures of the peptides derived in complex with LPS reveal boomerang-like beta-strand conformations that are stabilized by intimate packing between the two aromatic residues located at the 4 and 9 positions. This structural feature renders these peptides with a high ability to neutralize endotoxicity, >80% at 10 nM concentration, of LPS. Replacements of these aromatic residues either with Ala or with Leu destabilizes the boomerang structure with the concomitant loss of antiendotoxic and antimicrobial activities. Furthermore, the aromatic packing stabilizing the beta-boomerang structure in LPS is found to be maintained even in a truncated octapeptide, defining a structured LPS binding motif. The mode of action of the active designed peptides correlates well with their ability to perturb LPS micelle structures. Fourier transform infrared spectroscopy studies of the peptides delineate beta-type conformations and immobilization of phosphate head groups of LPS. Trp fluorescence studies demonstrated selective interactions with LPS and the depth of insertion into the LPS bilayer. Our results demonstrate the requirement of LPS-specific structures of peptides for endotoxin neutralizations. In addition, we propose that structures of these peptides may be employed to design proteins for the outer membrane.

Ficolins do not alter host immune responses to lipopolysaccharide-induced inflammation in vivo

DEFF Research Database (Denmark)

Genster, Ninette; Østrup, Olga; Schjalm, Camilla

2017-01-01

. Yet, the contribution of ficolins to inflammatory disease processes remains elusive. To address this, we investigated ficolin deficient mice during a lipopolysaccharide (LPS)-induced model of systemic inflammation. Although murine serum ficolin was shown to bind LPS in vitro, there was no difference...... an unaltered spleen transcriptome profile in ficolin deficient mice compared to wildtype mice. Collectively, results from this study demonstrate that ficolins are not involved in host response to LPS-induced systemic inflammation.......Ficolins are a family of pattern recognition molecules that are capable of activating the lectin pathway of complement. A limited number of reports have demonstrated a protective role of ficolins in animal models of infection. In addition, an immune modulatory role of ficolins has been suggested...

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

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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.

Effect of Lipopolysaccharide on Progesterone Production during Luteinization of Granulosa and Theca cells In Vitro.

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Shimizu, Takashi; Echizenya, Riku; Miyamoto, Akio

2016-04-01

The aim of this study is to examine the effect of lipopolysaccharide (LPS) on progesterone production during luteinization of granulosa and theca cells isolated from bovine large follicles. Granulosa and theca cells isolated from large follicles of bovine ovaries were exposed to LPS under appropriate hormone conditions in vitro. Progesterone (P4) production in theca cells, but not granulosa cells, was decreased by long-term exposure of LPS. Long-term exposure of LPS suppressed the gene expression of luteinizing hormone receptor in theca cells. Although long-term exposure of LPS did not affect the expression of steroidogenic acute regulatory protein (StAR) and 3β-hydroxy-steroid dehydrogenase (3β-HSD) genes, it did inhibit the protein expression of StAR and 3β-HSD in theca cells. These findings suggest that theca cells, rather than granulosa cells, are susceptible to LPS during luteinization and that LPS inhibits P4 production by decreasing protein levels of StAR during luteinization of theca cells. © 2016 Wiley Periodicals, Inc.

Minocycline hydrochloride nanoliposomes inhibit the production of TNF-α in LPS-stimulated macrophages

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Liu D

2012-08-01

Full Text Available D Liu, P S YangShandong Provincial Key Laboratory of Oral Biomedicine, College of Stomatology, Shandong University, Shandong Province, People's Republic of ChinaBackground: As an adjunctive treatment of chronic periodontitis, it seems that the application of periocline or the other antimicrobials is effective against periodontopathogens. In this study, nanoliposomes were investigated as carriers of minocycline hydrochloride and the inhibition effects of minocycline hydrochloride nanoliposomes on the proliferation and lipopolysaccharide (LPS-stimulated production of tumor necrosis factor-α (TNF-α of macrophages were elucidated.Methods: After stimulation with 10 µg/mL LPS, murine macrophages (ANA-1 were treated with 10, 20, 40, 50 and 70 µg/mL 2% minocycline hydrochloride nanoliposomes, minocycline hydrochloride solution, and periocline for 6, 12, 24, 48 and 60 hours, respectively. A tetrazolium (MTT assay was used to evaluate macrophages cell proliferation rate and the levels of TNF-α mRNA were measured by SYBR Green Real Time PCR.Results: Ten to 70 µg/mL 2% minocycline hydrochloride nanoliposomes, minocycline hydrochloride solution, and periocline showed dose- and time-dependent inhibition of ANA-1 proliferation. Minocycline hydrochloride nanoliposomes showed dose- and ratio-dependent inhibition of LPS-stimulated TNF-α secretion of ANA-1. The inhibition effect of 10 µg/mL minocycline hydrochloride nanoliposomes was significantly better than that of two positive control groups, and equated to that of 60 or 70 µg/mL periocline. The expression of TNF-α mRNA in experimental group continued to reduce linearly with time.Conclusion: All three preparations of minocycline hydrochloride showed dose- and time-dependent inhibition of proliferation of ANA-1. Minocycline hydrochloride nanoliposomes have stronger and longer inhibition effect on LPS-stimulated TNF-α secretion of macrophages cell than minocycline hydrochloride solution and periocline

Neisseria meningitidis expressing lgtB lipopolysaccharide targets DC-SIGN and modulates dendritic cell function.

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Steeghs, Liana; van Vliet, Sandra J; Uronen-Hansson, Heli; van Mourik, Andries; Engering, Anneke; Sanchez-Hernandez, Martha; Klein, Nigel; Callard, Robin; van Putten, Jos P M; van der Ley, Peter; van Kooyk, Yvette; van de Winkel, Jan G J

2006-02-01

Neisseria meningitidis lipopolysaccharide (LPS) has been identified as a major determinant of dendritic cell (DC) function. Here we report that one of a series of meningococcal mutants with defined truncations in the lacto-N-neotetraose outer core of the LPS exhibited unique strong adhesion and internalization properties towards DC. These properties were mediated by interaction of the GlcNAc(beta1-3)-Gal(beta1-4)-Glc-R oligosaccharide outer core of lgtB LPS with the dendritic-cell-specific ICAM-3 grabbing non-integrin (DC-SIGN) lectin receptor. Activation of DC-SIGN with this novel oligosaccharide ligand skewed T-cell responses driven by DC towards T helper type 1 activity. Thus, the use of lgtB LPS may provide a powerful instrument to selectively induce the desired arm of the immune response and potentially increase vaccine efficacy.

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

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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 ...

HemoHIM, a herbal preparation, alleviates airway inflammation caused by cigarette smoke and lipopolysaccharide

OpenAIRE

Shin, Na-Rae; Kim, Sung-Ho; Ko, Je-Won; Park, Sung-Hyeuk; Lee, In-Chul; Ryu, Jung-Min; Kim, Jong-Choon; Shin, In-Sik

2017-01-01

HemoHIM, herbal preparation has designed for immune system recovery. We investigated the anti-inflammatory effect of HemoHIM on cigarette smoke (CS) and lipopolysaccharide (LPS) induced chronic obstructive pulmonary disease (COPD) mouse model. To induce COPD, C57BL/6 mice were exposed to CS for 1 h per day (eight cigarettes per day) for 4 weeks and intranasally received LPS on day 26. HemoHIM was administrated to mice at a dose of 50 or 100 mg/kg 1h before CS exposure. HemoHIM reduced the inf...

Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

LENUS (Irish Health Repository)

Power, C

2012-02-03

INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

Prolonged neuroinflammation after lipopolysaccharide exposure in aged rats.

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Hui Qun Fu

Full Text Available Inflammation is a hallmark of several disease states ranging from neurodegeneration to sepsis but is also implicated in physiological processes like ageing. Non-resolving inflammation and prolonged neuroinflammation are unclear processes implicated in several conditions, including ageing. In this study we studied the long-term effects of endotoxemia, as systemic lipopolysaccharide (LPS injection, focusing on the role of astrocyte activation and cytokine release in the brain of aged rats. A single dose of LPS (2 mg/kg or 0.9% saline was injected intraperitoneally in aged rats. Levels of pro-inflammatory cytokines (TNFα and IL-1β and NF-κB p65 activation were measured systemically and in hippocampal tissue. Astrocytes and cytokines release in the CNS were detected via double immunofluorescence staining at different time-points up to day 30. Serum levels of TNFα and IL-1β were significantly increased acutely after 30 minutes (p<0.001 and up to 6 hours (p<0.001 following LPS-injection. Centrally, LPS-treated rats showed up-regulated mRNA expression and protein levels of pro-inflammatory cytokines in the hippocampus. These changes associated with astrogliosis in the hippocampus dentate gyrus (DG, IL-1β immunoreactivity and elevated NF-κB p65 expression up to day 30 post LPS exposure. Overall, these data demonstrate that LPS induces prolonged neuroinflammation and astrocyte activation in the hippocampus of aged rats. Hippocampal NF-κB p65 and excessive astrocytes-derived IL-1β release may play a pivotal role in regulating long-lasting neuroinflammation.

Effect of lipopolysaccharide on inflammation and insulin action in human muscle.

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Liang, Hanyu; Hussey, Sophie E; Sanchez-Avila, Alicia; Tantiwong, Puntip; Musi, Nicolas

2013-01-01

Accumulating evidence from animal studies suggest that chronic elevation of circulating intestinal-generated lipopolysaccharide (LPS) (i.e., metabolic endotoxemia) could play a role in the pathogenesis of insulin resistance. However, the effect of LPS in human muscle is unclear. Moreover, it is unknown whether blockade/down regulation of toll-like receptor (TLR)4 can prevent the effect of LPS on insulin action and glucose metabolism in human muscle cells. In the present study we compared plasma LPS concentration in insulin resistant [obese non-diabetic and obese type 2 diabetic (T2DM)] subjects versus lean individuals. In addition, we employed a primary human skeletal muscle cell culture system to investigate the effect of LPS on glucose metabolism and whether these effects are mediated via TLR4. Obese non-diabetic and T2DM subjects had significantly elevated plasma LPS and LPS binding protein (LBP) concentrations. Plasma LPS (r = -0.46, P = 0.005) and LBP (r = -0.49, P = 0.005) concentrations negatively correlated with muscle insulin sensitivity (M). In human myotubes, LPS increased JNK phosphorylation and MCP-1 and IL-6 gene expression. This inflammatory response led to reduced insulin-stimulated IRS-1, Akt and AS160 phosphorylation and impaired glucose transport. Both pharmacologic blockade of TLR4 with TAK-242, and TLR4 gene silencing, suppressed the inflammatory response and insulin resistance caused by LPS in human muscle cells. Taken together, these findings suggest that elevations in plasma LPS concentration found in obese and T2DM subjects could play a role in the pathogenesis of insulin resistance and that antagonists of TLR4 may improve insulin action in these individuals.

Soybean-derived Bowman-Birk inhibitor inhibits neurotoxicity of LPS-activated macrophages

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Persidsky Yuri

2011-02-01

Full Text Available Abstract Background Lipopolysaccharide (LPS, the major component of the outer membrane of gram-negative bacteria, can activate immune cells including macrophages. Activation of macrophages in the central nervous system (CNS contributes to neuronal injury. Bowman-Birk inhibitor (BBI, a soybean-derived protease inhibitor, has anti-inflammatory properties. In this study, we examined whether BBI has the ability to inhibit LPS-mediated macrophage activation, reducing the release of pro-inflammatory cytokines and subsequent neurotoxicity in primary cortical neural cultures. Methods Mixed cortical neural cultures from rat were used as target cells for testing neurotoxicity induced by LPS-treated macrophage supernatant. Neuronal survival was measured using a cell-based ELISA method for expression of the neuronal marker MAP-2. Intracellular reactive oxygen species (ROS production in macrophages was measured via 2', 7'-dichlorofluorescin diacetate (DCFH2DA oxidation. Cytokine expression was determined by quantitative real-time PCR. Results LPS treatment of macrophages induced expression of proinflammatory cytokines (IL-1β, IL-6 and TNF-α and of ROS. In contrast, BBI pretreatment (1-100 μg/ml of macrophages significantly inhibited LPS-mediated induction of these cytokines and ROS. Further, supernatant from BBI-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-BBI-pretreated and LPS-activated macrophage cultures. BBI, when directly added to the neuronal cultures (1-100 μg/ml, had no protective effect on neurons with or without LPS-activated macrophage supernatant treatment. In addition, BBI (100 μg/ml had no effect on N-methyl-D-aspartic acid (NMDA-mediated neurotoxicity. Conclusions These findings demonstrate that BBI, through its anti-inflammatory properties, protects neurons from neurotoxicity mediated by activated macrophages.

Preservation of renal blood flow by the antioxidant EUK-134 in LPS-treated pigs.

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Magder, Sheldon; Parthenis, Dimitrios G; Ghouleh, Imad Al

2015-03-25

Sepsis is associated with an increase in reactive oxygen species (ROS), however, the precise role of ROS in the septic process remains unknown. We hypothesized that treatment with EUK-134 (manganese-3-methoxy N,N'-bis(salicyclidene)ethylene-diamine chloride), a compound with superoxide dismutase and catalase activity, attenuates the vascular manifestations of sepsis in vivo. Pigs were instrumented to measure cardiac output and blood flow in renal, superior mesenteric and femoral arteries, and portal vein. Animals were treated with saline (control), lipopolysaccharide (LPS; 10 µg·kg-1·h-1), EUK-134, or EUK-134 plus LPS. Results show that an LPS-induced increase in pulmonary artery pressure (PAP) as well as a trend towards lower blood pressure (BP) were both attenuated by EUK-134. Renal blood flow decreased with LPS whereas superior mesenteric, portal and femoral flows did not change. Importantly, EUK-134 decreased the LPS-induced fall in renal blood flow and this was associated with a corresponding decrease in LPS-induced protein nitrotyrosinylation in the kidney. PO2, pH, base excess and systemic vascular resistance fell with LPS and were unaltered by EUK-134. EUK-134 also had no effect on LPS-associated increase in CO. Interestingly, EUK-134 alone resulted in higher CO, BP, PAP, mean circulatory filling pressure, and portal flow than controls. Taken together, these data support a protective role for EUK-134 in the renal circulation in sepsis.

Comparative conventional- and quantum dot-labelling strategies for LPS binding site detection in Arabidopsis thaliana mesophyll protoplasts

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Londiwe Siphephise Mgcina

2015-05-01

Full Text Available Lipopolysaccharide (LPS from Gram-negative bacteria is recognized as a microbe-associated molecular pattern (MAMP and not only induces an innate immune response in plants, but also stimulates the development of characteristic defense responses. However, identification and characterization of a cell surface LPS-receptor/binding site, as described in mammals, remains elusive in plants. As an amphiphilic, macromolecular lipoglycan, intact LPS potentially contains three MAMP-active regions, represented by the O-polysaccharide chain, the core and the lipid A. Binding site studies with intact labelled LPS were conducted in Arabidopsis thaliana protoplasts and quantified using flow cytometry fluorescence changes. Qdots, which allow non-covalent, hydrophobic labelling were used as a novel strategy in this study and compared to covalent, hydrophilic labelling with Alexa 488. Affinity for LPS-binding sites was clearly demonstrated by concentration-, temperature- and time-dependent increases in protoplast fluorescence following treatment with the labelled LPS. Moreover, this induced fluorescence increase was convincingly reduced following pre-treatment with excess unlabeled LPS, thereby indicating reversibility of LPS binding. Inhibition of the binding process is also reported using endo- and exocytosis inhibitors. Here, we present evidence for the anticipated presence of LPS-specific binding sites in Arabidopsis protoplasts, and furthermore propose Qdots as a more sensitive LPS-labelling strategy in comparison to the conventional Alexa 488 hydrazide label for binding studies.

Role of xanthine oxidase and reactive oxygen intermediates in LPS- and TNF-induced pulmonary edema.

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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).

Monocytes can be induced by lipopolysaccharide-triggered T lymphocytes to express functional factor VII/VIIa protease activity

OpenAIRE

1984-01-01

In the present study we demonstrate that human monocytes can be induced by the model stimulus, lipopolysaccharide (LPS), to produce and assemble on their surface functional Factor VII/VIIa. This protease was not induced in relatively purified monocytes alone following exposure to LPS; but was induced in the presence of Leu-3a positive helper/inducer T cells. The Factor VII/VIIa protease activity represented 35-40% of the potential initiating activity for the extrinsic coagulation pathway and ...

Piperine Augments the Protective Effect of Curcumin Against Lipopolysaccharide-Induced Neurobehavioral and Neurochemical Deficits in Mice.

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Jangra, Ashok; Kwatra, Mohit; Singh, Tavleen; Pant, Rajat; Kushwah, Pawan; Sharma, Yogita; Saroha, Babita; Datusalia, Ashok Kumar; Bezbaruah, Babul Kumar

2016-06-01

The aim of the present study was to investigate the protective effects of curcumin alone and in combination with piperine against lipopolysaccharide (LPS)-induced neurobehavioral and neurochemical deficits in the mice hippocampus. Mice were treated with curcumin (100, 200, and 400 mg/kg, p.o.) and piperine (20 mg/kg, p.o.) for 7 days followed by LPS (0.83 mg/kg, i.p.) administration. Animals exhibited anxiety and depressive-like phenotype after 3 and 24 h of LPS exposure, respectively. LPS administration increased the oxido-nitrosative stress as evident by elevated levels of malondialdehyde, nitrite, and depletion of glutathione level in the hippocampus. Furthermore, we found raised level of pro-inflammatory cytokines (IL-1β and TNF-α) in the hippocampus of LPS-treated mice. Pretreatment with curcumin alleviated LPS-induced neurobehavioral and neurochemical deficits. Furthermore, co-administration of curcumin with piperine significantly potentiated the neuroprotective effect of curcumin. These results demonstrate that piperine enhanced the neuroprotective effect of curcumin against LPS-induced neurobehavioral and neurochemical deficits.

C-Reactive Protein (CRP), Interferon Gamma-Inducible Protein 10 (IP-10), and Lipopolysaccharide (LPS) Are Associated with Risk of Tuberculosis after Initiation of Antiretroviral Therapy in Resource-Limited Settings

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Tenforde, Mark W.; Gupte, Nikhil; Dowdy, David W.; Asmuth, David M.; Balagopal, Ashwin; Pollard, Richard B.; Sugandhavesa, Patcharaphan; Lama, Javier R.; Pillay, Sandy; Cardoso, Sandra W.; Pawar, Jyoti; Santos, Breno; Riviere, Cynthia; Mwelase, Noluthando; Kanyama, Cecilia; Kumwenda, Johnstone; Hakim, James G.; Kumarasamy, Nagalingeswaran; Bollinger, Robert; Semba, Richard D.; Campbell, Thomas B.; Gupta, Amita

2015-01-01

Objective The association between pre-antiretroviral (ART) inflammation and immune activation and risk for incident tuberculosis (TB) after ART initiation among adults is uncertain. Design Nested case-control study (n = 332) within ACTG PEARLS trial of three ART regimens among 1571 HIV-infected, treatment-naïve adults in 9 countries. We compared cases (participants with incident TB diagnosed by 96 weeks) to a random sample of controls (participants who did not develop TB, stratified by country and treatment arm). Methods We measured pre-ART C-reactive protein (CRP), EndoCab IgM, ferritin, interferon gamma (IFN-γ), interleukin 6 (IL-6), interferon gamma-inducible protein 10 (IP-10), lipopolysaccharide (LPS), soluble CD14 (sCD14), tumor necrosis factor alpha (TNF-α), and CD4/DR+/38+ and CD8/DR+/38+ T cells. Markers were defined according to established cutoff definitions when available, 75th percentile of measured values when not, and detectable versus undetectable for LPS. Using logistic regression, we measured associations between biomarkers and incident TB, adjusting for age, sex, study site, treatment arm, baseline CD4 and log10 viral load. We assessed the discriminatory value of biomarkers using receiver operating characteristic (ROC) analysis. Results Seventy-seven persons (4.9%) developed incident TB during follow-up. Elevated baseline CRP (aOR 3.25, 95% CI: 1.55–6.81) and IP-10 (aOR 1.89, 95% CI: 1.05–3.39), detectable plasma LPS (aOR 2.39, 95% CI: 1.13–5.06), and the established TB risk factors anemia and hypoalbuminemia were independently associated with incident TB. In ROC analysis, CRP, albumin, and LPS improved discrimination only modestly for TB risk when added to baseline routine patient characteristics including CD4 count, body mass index, and prior TB. Conclusion Incident TB occurs commonly after ART initiation. Although associated with higher post-ART TB risk, baseline CRP, IP-10, and LPS add limited value to routine patient characteristics

Systemic administration of lipopolysaccharide increases the expression of aquaporin-4 in the rat anterior pituitary gland.

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Kuwahara-Otani, Sachi; Maeda, Seishi; Tanaka, Koichi; Hayakawa, Tetsu; Seki, Makoto

2013-01-01

We investigated the effects of lipopolysaccharide (LPS)-induced endotoxemia on the expression of aquaporin-4 (AQP4) in the rat anterior pituitary gland, using the real-time polymerase chain reaction and immunohistochemistry. After intraperitoneal injection of LPS, the level of AQP4 mRNA doubled at 2, 4 and 8 hr. Immunohistochemical analysis showed an increase with time in AQP4 immunostaining in folliculo-stellate cells following LPS injection; the intensity of immunoreactivity peaked at 8 hr. At the same time, some cyst-like structures, formed by AQP4-positive cells, were observed. These findings indicate that LPS induces the expression of AQP4 in the anterior pituitary gland. The present results should provide an important key to elucidate the pathogenesis of the anterior pituitary gland during endotoxemia.

Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans.

Science.gov (United States)

Palma, C; Cassone, A; Serbousek, D; Pearson, C A; Djeu, J Y

1992-11-01

Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented release of lactoferrin, an iron-binding protein which itself could inhibit the growth of C. albicans in vitro. Antibodies against lactoferrin effectively and specifically reduced the anti-C. albicans activity of both LPS-stimulated and unstimulated PMN. Northern (RNA blot) analysis showed enhanced production of mRNAs for interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 and in neutrophils within 1 h of stimulation with LPS. The cytokines were also detected in the supernatant of the activated PMN, and their synthesis was prevented by pretreatment of LPS-stimulated PMN with protein synthesis inhibitors, such as emetine and cycloheximide. These inhibitors, however, did not block either lactoferrin release or the anti-Candida activity of LPS-stimulated PMN. These results demonstrate the ability of various bacterial LPSs to augment neutrophil function against C. albicans and suggest that the release of a candidastatic, iron-binding protein, lactoferrin, may contribute to the antifungal effect of PMN. Moreover, the ability to produce cytokines upon stimulation by ubiquitous microbial products such as the endotoxins points to an extraphagocytic, immunomodulatory role of PMN during infection.

Obese mice exhibit an altered behavioural and inflammatory response to lipopolysaccharide

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Catherine B. Lawrence

2012-09-01

Obesity is associated with an increase in the prevalence and severity of infections. Genetic animal models of obesity (ob/ob and db/db mice display altered centrally-mediated sickness behaviour in response to acute inflammatory stimuli such as lipopolysaccharide (LPS. However, the effect of diet-induced obesity (DIO on the anorectic and febrile response to LPS in mice is unknown. This study therefore determined how DIO and ob/ob mice respond to a systemic inflammatory challenge. C57BL/6 DIO and ob/ob mice, and their respective controls, were given an intraperitoneal (i.p. injection of LPS. Compared with controls, DIO and ob/ob mice exhibited an altered febrile response to LPS (100 μg/kg over 8 hours. LPS caused a greater and more prolonged anorexic effect in DIO compared with control mice and, in ob/ob mice, LPS induced a reduction in food intake and body weight earlier than it did in controls. These effects of LPS in obese mice were also seen after a fixed dose of LPS (5 μg. LPS (100 μg/kg induced Fos protein expression in several brain nuclei of control mice, with fewer Fos-positive cells observed in the brains of obese mice. An altered inflammatory response to LPS was also observed in obese mice compared with controls: changes in cytokine expression and release were detected in the plasma, spleen, liver and peritoneal macrophages in obese mice. In summary, DIO and ob/ob mice displayed an altered behavioural response and cytokine release to systemic inflammatory challenge. These findings could help explain why obese humans show increased sensitivity to infections.

Characterization of Chemically-Induced Bacterial Ghosts (BGs Using Sodium Hydroxide-Induced Vibrio parahaemolyticus Ghosts (VPGs

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Hyun Jung Park

2016-11-01

Full Text Available Acellular bacterial ghosts (BGs are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene E of bacteriophage PhiX174. In this study, Vibrio parahaemolyticus ghosts (VPGs were generated by chemically-induced lysis and the method is based on minimum inhibitory concentration (MIC of sodium hydroxide (NaOH, acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid, and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, <50.0, 25.0, 6.25, 1.56, and 0.781 mg/mL. Except for boric acid, the lysis efficiency reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs appeared completely DNA-free, which was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells, as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened, or modified by the MIC of NaOH. Nevertheless, Limulus amoebocyte lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 106 CFU/mL showed cell viability of 97.9%, however, the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like Escherichia coli LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS, anti-inflammatory cytokine (IL-10, and dual activities (IL-6 in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning

Differential myelopoietic responsiveness of BALB/c (Itys) and C.D2 (Ityr) mice to lipopolysaccharide administration and Salmonella typhimurium infection.

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Peterson, V M; Madonna, G S; Vogel, S N

1992-04-01

Inheritance of the Ityr or the Itys allele of the Ity murine gene confers resistance or increased susceptibility, respectively, to Salmonella typhimurium infection. Recent studies have documented that Ity gene expression may determine net intracellular replication of S. typhimurium by modulating macrophage function. The purpose of this study was to determine if Ity gene expression modulated macrophage stem cell proliferation as well. To detect possible Ity-associated alterations in macrophage stem cell proliferation during endotoxin challenge or S. typhimurium infection, the congenic strain pair BALB/c (Itys) and C.D2-Idh-1, Pep-3 N20F8 (Ityr) were injected intraperitoneally with 25 micrograms of bacterial lipopolysaccharide (LPS) or approximately 10(3) S. typhimurium, and myelopoiesis was evaluated. At 72 h after LPS injection, both BALB/c and C.D2 mice developed comparable degrees of bone marrow hypocellularity and splenomegaly, and cell sizing profiles indicated a normal response to a single injection of LPS in both strains of mice. Although an inhibitor to colony-stimulating factor activity was detected in the sera and plasma of C.D2 mice, the number of myeloid stem cells cultured from the bone marrow and spleen of each mouse strain were comparable. S. typhimurium infection resulted in earlier symptoms, a larger bacterial load, a higher mortality rate, and a greater bone marrow hypocellularity and splenomegaly in BALB/c mice compared with those in C.D2 mice. Despite a dramatic increase in bacterial load, a decrease in both bone marrow and splenic myeloid stem cell numbers was noted in BALB/c mice, while stem cell numbers remained constant in C.D2 mice between days 3 and 5 and increased dramatically at day 7 after infection. These data suggest that BALB/c and C.D2 mice may exhibit a divergent myelopoietic response to S. typhimurium infection. It appears that a paradoxical failure of myelopoiesis in Itys mice during S. typhimurium infection may contribute to the

Production of macrophage inflammatory protein (MIP)-1alpha and MIP-1beta by human polymorphonuclear neutrophils stimulated with Porphyromonas endodontalis lipopolysaccharide.

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Ko, Hyun Jung; Lim, Sung Sam

2002-11-01

This study was undertaken to investigate the capacity of polymorphonuclear neutrophils (PMNs) to secrete Macrophage Inflammatory Protein (MIP)-1alpha and MIP-1beta after stimulation with Porphyromonas endodontalis lipopolysaccharide (LPS). Escherichia coli LPS was used as a positive control. Venous blood was collected and PMNs were isolated from healthy volunteers. Cells were cultured with various concentrations of LPS for different periods of time. Cell supernatants were assayed by enzyme-linked immunosorbent assay. The levels of chemokine secretion in PMNs stimulated with each LPS were found to be significantly higher than in the unstimulated control cells (p endodontalis LPS. These findings demonstrated that P. endodontalis LPS is capable of stimulating PMNs to produce chemotactic cytokines and suggested that PMNs stimulated with P. endodontalis LPS may play a crucial role in the inflammatory and immunopathological reactions of pulpal and periapical diseases.

Synergistic effects of pyrrolizidine alkaloids and lipopolysaccharide on preterm delivery and intrauterine fetal death in mice.

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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.

A Fermented Whole Grain Prevents Lipopolysaccharides-Induced Dysfunction in Human Endothelial Progenitor Cells

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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.

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.

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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.

Focal Targeting of the Bacterial Envelope by Antimicrobial Peptides

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Rafi eRashid

2016-06-01

Full Text Available Antimicrobial peptides (AMPs are utilized by both eukaryotic and prokaryotic organisms. AMPs such as the human beta defensins, human neutrophil peptides, human cathelicidin, and many bacterial bacteriocins are cationic and capable of binding to anionic regions of the bacterial surface. Cationic AMPs (CAMPs target anionic lipids (e.g. phosphatidylglycerol (PG and cardiolipins (CL in the cell membrane and anionic components (e.g. lipopolysaccharide (LPS and lipoteichoic acid (LTA of the cell envelope. Bacteria have evolved mechanisms to modify these same targets in order to resist CAMP killing, e.g. lysinylation of PG to yield cationic lysyl-PG and alanylation of LTA. Since CAMPs offer a promising therapeutic alternative to conventional antibiotics, which are becoming less effective due to rapidly emerging antibiotic resistance, there is a strong need to improve our understanding about the AMP mechanism of action. Recent literature suggests that AMPs often interact with the bacterial cell envelope at discrete foci. Here we review recent AMP literature, with an emphasis on focal interactions with bacteria, including (1 CAMP disruption mechanisms, (2 delocalization of membrane proteins and lipids by CAMPs, and (3 CAMP sensing systems and resistance mechanisms. We conclude with new approaches for studying the bacterial membrane, e.g., lipidomics, high resolution imaging and non-detergent-based membrane domain extraction.

Cytokine and acute phase protein gene expression in liver biopsies from dairy cows with a lipopolysaccharide - induced mastitis

DEFF Research Database (Denmark)

Vels, J; Røntved, Christine M.; Bjerring, Martin

2009-01-01

A minimally invasive liver biopsy technique was tested for its applicability to study the hepatic acute phase response (APR) in dairy cows with Escherichia coli lipopolysaccharide (LPS)-induced mastitis. The hepatic mRNA expression profiles of the inflammatory cytokines, tumor necrosis factor (TNF......, a minimally invasive liver biopsy technique can be used for studying the hepatic APR in diseased cattle. Lipopolysaccharide-induced mastitis resulted in a time-dependent production of inflammatory cytokines and SAA and Hp in the liver of dairy cows.......- ), IL-1β, IL-6, and IL-10, and the acute phase proteins serum amyloid A isoform 3 (SAA3), haptoglobin (Hp), and 1-acid glycoprotein (AGP) were determined by real-time reverse transcription-PCR. Fourteen primiparous cows in mid lactation were challenged with 200 µg of LPS (n = 8) or NaCl solution (n = 6...

Energetics of Endotoxin Recognition in the Toll-Like Receptor 4 Innate Immune Response.

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Paramo, Teresa; Tomasio, Susana M; Irvine, Kate L; Bryant, Clare E; Bond, Peter J

2015-12-09

Bacterial outer membrane lipopolysaccharide (LPS) potently stimulates the mammalian innate immune system, and can lead to sepsis, the primary cause of death from infections. LPS is sensed by Toll-like receptor 4 (TLR4) in complex with its lipid-binding coreceptor MD-2, but subtle structural variations in LPS can profoundly modulate the response. To better understand the mechanism of LPS-induced stimulation and bacterial evasion, we have calculated the binding affinity to MD-2 of agonistic and antagonistic LPS variants including lipid A, lipid IVa, and synthetic antagonist Eritoran, and provide evidence that the coreceptor is a molecular switch that undergoes ligand-induced conformational changes to appropriately activate or inhibit the receptor complex. The plasticity of the coreceptor binding cavity is shown to be essential for distinguishing between ligands, whilst similar calculations for a model bacterial LPS bilayer reveal the "membrane-like" nature of the protein cavity. The ability to predict the activity of LPS variants should facilitate the rational design of TLR4 therapeutics.

Thymoquinone restores liver fibrosis and improves oxidative stress status in a lipopolysaccharide-induced inflammation model in rats

OpenAIRE

Asgharzadeh, Fereshteh; Bargi, Rahimeh; Beheshti, Farimah; Hosseini, Mahmoud; Farzadnia, Mehdi; Khazaei, Majid

2017-01-01

Objective: Liver fibrosis is the primary sign of chronic liver injury induced by various causes. Thymoquinone (TQ) is the major ingredient of Nigella sativa with several beneficial effects on the body. In the present study, we aimed to investigate the effect of TQ on liver fibrosis in a lipopolysaccharide (LPS)-induced inflammation in male rats. Materials and methods: Fifty male Wistar rats were randomly divided into five groups (n=10 in each group) as follow: (1) control; (2) LPS (1 mg/kg/da...

Thymoquinone restores liver fibrosis and improves oxidative stress status in a lipopolysaccharide-induced inflammation model in rats

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Fereshteh Asgharzadeh

2017-10-01

Full Text Available Objective: Liver fibrosis is the primary sign of chronic liver injury induced by various causes. Thymoquinone (TQ is the major ingredient of Nigella sativa with several beneficial effects on the body. In the present study, we aimed to investigate the effect of TQ on liver fibrosis in a lipopolysaccharide (LPS-induced inflammation in male rats. Materials and methods: Fifty male Wistar rats were randomly divided into five groups (n=10 in each group as follow: (1 control; (2 LPS (1 mg/kg/day; i.p; (3 LPS+TQ 2 mg/kg/day (i.p (LPs+TQ2; (4 LPS+TQ 5 mg/kg/day (LPS+TQ5; (5 LPS+ TQ 10 mg/kg/day (LPS+ TQ10. After three weeks, blood samples were taken for evaluation of liver function tests. Then, the livers were harvested for histological evaluation of fibrosis and collagen content and measurement of oxidative stress markers including malondialdehyde (MDA, total thiol groups, superoxide dismutase (SOD and catalase activity in tissue homogenates. Results: LPS group showed higher levels of fibrosis and collagen content stained by Masson’s trichrome in liver tissue with impaired liver function test and increased oxidative stress markers (p

The effects of propolis on cytokine production in lipopolysaccharide-stimulated macrophages

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Hatice Özbilge

2011-12-01

Full Text Available Objectives: Propolis, a bee-product, has attracted researchers’ interest in recent years because of several biological and pharmacological properties. Lipopolysaccharide (LPS is a component of the outer membrane of Gram-negative bacteria and has an important role in the pathogenesis of septic shock and several inflammatory diseases by causing excessive release of inflammatory cytokines. The aim of this study was to investigate the effects of ethanol extract of propolis collected in Kayseri and its surroundings on production of pro-inflammatory cytokines in LPS-stimulated macrophages.Materials and methods: In vitro, U937 human macrophage cells were grown in RPMI-1640 medium supplemented with fetal bovine serum (10% and penicillin-streptomycin (2% and divided into: control, LPS treated, and propolis+LPS treated cell groups. After incubation in an atmosphere of 5% CO2 and at 37°C of cells, interleukin (IL-1β, IL-6 and tumor necrosis factor (TNF-α levels were measured in cell-free supernatants by ELISA.Results: IL-1β, IL-6 and TNF-α levels increased in LPS treated cell group according to control, statistically significant. Each cytokine levels significantly decreased in LPS and propolis treated cell group according to only LPS treated cell group (p<0.05.Conclusion: Propolis is a natural product to be examined for usage when needed the suppression of pro-inflammatory cytokines. J Clin Exp Invest 2011; 2 (4: 366-370

Inhibitory Effects of Ketamine on Lipopolysaccharide-Induced Microglial Activation

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Yi Chang

2009-01-01

Full Text Available Microglia activated in response to brain injury release neurotoxic factors including nitric oxide (NO and proinflammatory cytokines such as tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β. Ketamine, an anesthetic induction agent, is generally reserved for use in patients with severe hypotension or respiratory depression. In this study, we found that ketamine (100 and 250 μM concentration-dependently inhibited lipopolysaccharide (LPS-induced NO and IL-1β release in primary cultured microglia. However, ketamine (100 and 250 μM did not significantly inhibit the LPS-induced TNF-α production in microglia, except at the higher concentration (500 μM. Further study of the molecular mechanisms revealed that ketamine markedly inhibited extracellular signal-regulated kinase (ERK1/2 phosphorylation but not c-Jun N-terminal kinase or p38 mitogen-activated protein kinase stimulated by LPS in microglia. These results suggest that microglial inactivation by ketamine is at least partially due to inhibition of ERK1/2 phosphorylation.

The relationship between lymphocytes activated by pokeweed mitogen and by lipopolysaccharides and their radiosensitivity

International Nuclear Information System (INIS)

Su Liaoyuan; Liu Fenju; Liu Keliang; Xu Changshao; Xu Yingdong; Geng Yongzhi

1992-07-01

Human whole blood was incubated in vitro. Lymphocytes were activated by poke-weed mitogen (PWM) and by Lipopolysaccharides (LPS). The relationship between the two kinds of lymphocytes was investigated using radioactive compound incorporation. The study showed that PWM-activated lymphocytes were able to promote the stimulating effect of LPS on B lymphocytes. The stimulating effect of PWM-activated lymphocytes was obviously decreased after they were irradiated with 10 Gy gamma rays. When PWM-activated lymphocytes and LPS-activated lymphocytes were incubated together after one of the cell populations had been exposed 10 Gy 60 Co gamma rays, the incorporation of [ 3 H] TdR was much decreased and the synergistic function disappeared, especially when the PWM-activated lymphocytes were irradiated. In cells from patients treated with 60 Co gamma rays for carcinoma of nasopharynx, the incorporation in LPS-activated lymphocytes approached normal levels while that in PWM-activated lymphocytes was reduced significantly and the stimulating effect of PWM-activated lymphocytes on LPS-activated lymphocytes was also markedly reduced. These demonstrate that PWM-activated lymphocytes have a similar function to T-helper cells and seem to be more radiosensitive than LPS-activated lymphocytes

Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species.

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Patra, Kailash P; Choudhury, Biswa; Matthias, Michael M; Baga, Sheyenne; Bandyopadhya, Keya; Vinetz, Joseph M

2015-10-30

Lipopolysaccharides (LPS) are complex, amphipathic biomolecules that constitute the major surface component of Gram-negative bacteria. Leptospira, unlike other human-pathogenic spirochetes, produce LPS, which is fundamental to the taxonomy of the genus, involved in host-adaption and also the target of diagnostic antibodies. Despite its significance, little is known of Leptospira LPS composition and carbohydrate structure among different serovars. LPS from Leptospira interrogans serovar Copenhageni strain L1-130, a pathogenic species, and L. licerasiae serovar Varillal strain VAR 010, an intermediately pathogenic species, were studied. LPS prepared from aqueous and phenol phases were analyzed separately. L. interrogans serovar Copenhageni has additional sugars not found in L. licerasiae serovar Varillal, including fucose (2.7%), a high amount of GlcNAc (12.3%), and two different types of dideoxy HexNAc. SDS-PAGE indicated that L. interrogans serovar Copenhageni LPS had a far higher molecular weight and complexity than that of L. licerasiae serovar Varillal. Chemical composition showed that L. interrogans serovar Copenhageni LPS has an extended O-antigenic polysaccharide consisting of sugars, not present in L. licerasiae serovar Varillal. Arabinose, xylose, mannose, galactose and L-glycero-D-mannoheptose were detected in both the species. Fatty acid analysis by gas chromatography-mass spectrometry (GC-MS) showed the presence of hydroxypalmitate (3-OH-C16:0) only in L. interrogans serovar Copenhageni. Negative staining electron microscopic examination of LPS showed different filamentous morphologies in L. interrogans serovar Copenhageni vs. L. licerasiae serovar Varillal. This comparative biochemical analysis of pathogenic and intermediately pathogenic Leptospira LPS reveals important carbohydrate and lipid differences that underlie future work in understanding the mechanisms of host-adaptation, pathogenicity and vaccine development in leptospirosis.

17beta-estradiol and progesterone do not influence the production of cytokines from lipopolysaccharide-stimulated monocytes in humans

NARCIS (Netherlands)

Bouman, Annechien; Schipper, Martin; Heineman, Maas Jan; Faas, Marijke

2004-01-01

OBJECTIVE: To test whether 17beta-estradiol or progesterone influence the cytokine productive capacity of lipopolysaccharide (LPS)-stimulated monocytes in humans. DESIGN: Prospective study. SETTING: Academic research institution. PATIENT(S): Seven women in the luteal phase of a normal ovarian cycle,

17 beta-estradiol and progesterone do not influence the production of cytokines from lipopolysaccharide-stimulated monocytes in humans

NARCIS (Netherlands)

Schipper, M; Heineman, MJ; Faas, M; Bouman, A.

2004-01-01

Objective: To test whether 17beta-estradiol or progesterone influence the cytokine productive capacity of lipopolysaccharide (LPS)-stimulated monocytes in humans. Design: Prospective study. Setting: Academic research institution. Patient(s): Seven women in the luteal phase of a normal ovarian cycle,

Effects of lipopolysaccharide (LPS) induced inflammatory response on early embryo survival in ewes

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Early pregnant ewes were used to determine the effects of endogenous (through LPS activation) and exogenous TNF-alpha tumor necrosis factor-alpha (TNF-alpha) on embryonic loss. Thirty-eight Dorset x Texel ewes were synchronized for estrus and bred to fertile rams (d0). On d5/6, ewes were assigned t...

Shiga toxin 1 induces on lipopolysaccharide-treated astrocytes the release of tumor necrosis factor-alpha that alter brain-like endothelium integrity.

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Verónica I Landoni

Full Text Available The hemolytic uremic syndrome (HUS is characterized by hemolytic anemia, thrombocytopenia and renal dysfunction. The typical form of HUS is generally associated with infections by Gram-negative Shiga toxin (Stx-producing Escherichia coli (STEC. Endothelial dysfunction induced by Stx is central, but bacterial lipopolysaccharide (LPS and neutrophils (PMN contribute to the pathophysiology. Although renal failure is characteristic of this syndrome, neurological complications occur in severe cases and is usually associated with death. Impaired blood-brain barrier (BBB is associated with damage to cerebral endothelial cells (ECs that comprise the BBB. Astrocytes (ASTs are inflammatory cells in the brain and determine the BBB function. ASTs are in close proximity to ECs, hence the study of the effects of Stx1 and LPS on ASTs, and the influence of their response on ECs is essential. We have previously demonstrated that Stx1 and LPS induced activation of rat ASTs and the release of inflammatory factors such as TNF-α, nitric oxide and chemokines. Here, we demonstrate that rat ASTs-derived factors alter permeability of ECs with brain properties (HUVECd; suggesting that functional properties of BBB could also be affected. Additionally, these factors activate HUVECd and render them into a proagregant state promoting PMN and platelets adhesion. Moreover, these effects were dependent on ASTs secreted-TNF-α. Stx1 and LPS-induced ASTs response could influence brain ECs integrity and BBB function once Stx and factors associated to the STEC infection reach the brain parenchyma and therefore contribute to the development of the neuropathology observed in HUS.

Shiga Toxin 1 Induces on Lipopolysaccharide-Treated Astrocytes the Release of Tumor Necrosis Factor-alpha that Alter Brain-Like Endothelium Integrity

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Landoni, Verónica I.; Schierloh, Pablo; de Campos Nebel, Marcelo; Fernández, Gabriela C.; Calatayud, Cecilia; Lapponi, María J.; Isturiz, Martín A.

2012-01-01

The hemolytic uremic syndrome (HUS) is characterized by hemolytic anemia, thrombocytopenia and renal dysfunction. The typical form of HUS is generally associated with infections by Gram-negative Shiga toxin (Stx)-producing Escherichia coli (STEC). Endothelial dysfunction induced by Stx is central, but bacterial lipopolysaccharide (LPS) and neutrophils (PMN) contribute to the pathophysiology. Although renal failure is characteristic of this syndrome, neurological complications occur in severe cases and is usually associated with death. Impaired blood-brain barrier (BBB) is associated with damage to cerebral endothelial cells (ECs) that comprise the BBB. Astrocytes (ASTs) are inflammatory cells in the brain and determine the BBB function. ASTs are in close proximity to ECs, hence the study of the effects of Stx1 and LPS on ASTs, and the influence of their response on ECs is essential. We have previously demonstrated that Stx1 and LPS induced activation of rat ASTs and the release of inflammatory factors such as TNF-α, nitric oxide and chemokines. Here, we demonstrate that rat ASTs-derived factors alter permeability of ECs with brain properties (HUVECd); suggesting that functional properties of BBB could also be affected. Additionally, these factors activate HUVECd and render them into a proagregant state promoting PMN and platelets adhesion. Moreover, these effects were dependent on ASTs secreted-TNF-α. Stx1 and LPS-induced ASTs response could influence brain ECs integrity and BBB function once Stx and factors associated to the STEC infection reach the brain parenchyma and therefore contribute to the development of the neuropathology observed in HUS. PMID:22479186

Recurrent exposure to subclinical lipopolysaccharide increases mortality and induces cardiac fibrosis in mice.

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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.

Glucocorticoid inhibition of leptin- and lipopolysaccharide-induced interleukin-6 production in obesity.

Science.gov (United States)

Huang, Chun-Jung; Acevedo, Edmund O; Mari, David C; Randazzo, Christopher; Shibata, Yoshimi

2014-01-01

Obesity is considered a chronic inflammatory condition that enhances the risk of numerous inflammatory diseases, including diabetes and cardiovascular disease. Glucocorticoids (GCs) and synthetic therapeutic GCs are anti-inflammatory agents, but the exact functions of GCs in obesity-related inflammation are unknown. Therefore, the objective of this study was to examine the inhibitory effect of an exogenous GC (dexamethasone, DEX) on leptin- and lipopolysaccharide (LPS)-induced IL-6 production by peripheral blood mononuclear cells (PBMCs) ex vivo in obese subjects compared to normal-weight subjects. Blood samples were drawn from 14 obese (BMI>30 kg/m(2)) and 14 normal-weight (BMIobese subjects showed greater leptin- and LPS-induced IL-6 production compared to normal-weight subjects. The suppressive effect of DEX on leptin- and LPS-induced IL-6 production (IC50) was not different between the two groups. However, the IC50 of DEX for LPS-induced was correlated with BMI, waist circumference, and hip circumference. These findings suggest that reduced GC sensitivity may be an important mechanism in the up-regulation of selected obese inflammation. Published by Elsevier Inc.

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)

Gut microbiota-derived lipopolysaccharide uptake and trafficking to adipose tissue: implications for inflammation and obesity.

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Hersoug, L-G; Møller, P; Loft, S

2016-04-01

The composition of the gut microbiota and excessive ingestion of high-fat diets (HFD) are considered to be important factors for development of obesity. In this review we describe a coherent mechanism of action for the development of obesity, which involves the composition of gut microbiota, HFD, 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 are transported via lymph to the circulation, where LPS is transferred to other lipoproteins by translocases, preferentially to HDL. LPS increases the SR-BI binding, transcytosis of lipoproteins over the endothelial barrier,and endocytosis in adipocytes. Especially large size adipocytes with high metabolic 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 is involved in the development of obesity as a direct targeting molecule for lipid delivery and storage in adipose tissue. © 2015 World Obesity.

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.

Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

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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.

Dopamine-dependent neurotoxicity of lipopolysaccharide in substantia nigra.

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De Pablos, Rocío M; Herrera, Antonio J; Villarán, Ruth F; Cano, Josefina; Machado, Alberto

2005-03-01

Intranigral injection of lipopolysaccharide (LPS), a potent inductor of inflammation, induces degeneration of dopaminergic neurons, along with an inflammatory process that features activation of microglial cells and loss of astrocytes. To test the involvement of dopamine (DA) in this degeneration induced by LPS, we treated albino Wistar rats with different concentrations of alpha-methyl-p-tyrosine (alpha-MPT), an inhibitor of tyrosine hydroxylase (TH) activity. Results showed that alpha-MPT prevented LPS-induced loss of TH immunostaining and expression of mRNA for TH and DA transporter; it also prevented substantial activation of microglial cells. Loss of the astroglial population, a marker of damage in our model, was also prevented. This protective effect resulted from inhibition of TH and the consequent decrease in DA concentration, because treatment with L-DOPA/benserazide, which bypasses TH inhibition induced by alpha-MPT, reversed the protective effect produced by this drug. These results point out the important contribution of DA to the vulnerability and degeneration of dopaminergic neurons of the substantia nigra. Knowledge about the involvement of DA in this process may lead to the possibility of new protection strategies against this important degenerative process.

Peptide-assembled graphene oxide as fluorescent turn-on sensor for ultrasensitive Lipopolysaccharide (Endotoxin detection

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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.

Involvement of interleukin-23 induced by Porphyromonas endodontalis lipopolysaccharide in osteoclastogenesis

OpenAIRE

Ma, Nan; Yang, Di; Okamura, Hirohiko; Teramachi, Jumpei; Hasegawa, Tomokazu; Qiu, Lihong; Haneji, Tatsuji

2016-01-01

Periapical lesions are characterized by the destruction of periapical bone, and occur as a result of local inflammatory responses to root canal infection by microorganisms including Porphyromonas endodontalis (P. endodontalis). P. endodontalis and its primary virulence factor, lipopolysaccharide (LPS), are associated with the development of periapical lesions and alveolar bone loss. Interleukin-23 (IL-23) is critical in the initiation and progression of periodontal disease via effects on peri...

Suppression of the lipopolysaccharide-induced expression of MARCKS-related protein (MRP) affects transmigration in activated RAW264.7 cells.

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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.

A simple method for purification of lipopolysaccharides from E. coli 55:B5 using size exclusion chromatography

International Nuclear Information System (INIS)

Perdomo, Rolando; Montero, Vivian

2006-01-01

Several methods for the extraction of endotoxin or lipopolysaccharide from Gram negative bacteria have been described. However, the product is often contaminated with nucleic acids or proteins in a proportion depending on the extraction method used. Molecular and immunological studies require further purification of the raw LPS. We present here, a simple method for the purification of raw LPS obtained by the standard hot phenol-water procedure using size exclusion chromatography in Sepharose CL-6B. We demonstrated that the using of DNAse and RNAse treatment of the sample before the chromatographic step is necessary to abrogate the nucleic acid contamination in the LPS fraction. The spectrophotometric properties of the pure LPS were verified, supporting the immediate online detection of the LPS and oligonucleotides fractions spectrophotometrically at 206 nm. The mobile phase used (NaCl 0.2 M) do not absorb at 206 nm while maintains the LPS aggregates and therefore, allows the separation of the LPS fraction from the oligoribonucleotide and desoxioligoribonucleotide fractions. The yield of pure LPS was around 98%. Chemical and biological characterizations were conducted in order to assess the feasibility of the procedure developed. (Author)

Nitric oxide-mediated maintenance of redox homeostasis contributes to NPR1-dependent plant innate immunity triggered by lipopolysaccharides.

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Sun, Aizhen; Nie, Shengjun; Xing, Da

2012-10-01

The perception of lipopolysaccharides (LPS) by plant cells can lead to nitric oxide (NO) production and defense gene induction. However, the signaling cascades underlying these cellular responses have not yet been resolved. This work investigated the biosynthetic origin of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) to gain insight into the mechanism involved in LPS-induced resistance of Arabidopsis (Arabidopsis thaliana). Analysis of inhibitors and mutants showed that LPS-induced NO synthesis was mainly mediated by an arginine-utilizing source of NO generation. Furthermore, LPS-induced NO caused transcript accumulation of alternative oxidase genes and increased antioxidant enzyme activity, which enhanced antioxidant capacity and modulated redox state. We also analyzed the subcellular localization of NPR1 to identify the mechanism for protein-modulated plant innate immunity triggered by LPS. LPS-activated defense responses, including callose deposition and defense-related gene expression, were found to be regulated through an NPR1-dependent pathway. In summary, a significant NO synthesis induced by LPS contributes to the LPS-induced defense responses by up-regulation of defense genes and modulation of cellular redox state. Moreover, NPR1 plays an important role in LPS-triggered plant innate immunity.

Selenium Pretreatment Alleviated LPS-Induced Immunological Stress Via Upregulation of Several Selenoprotein Encoding Genes in Murine RAW264.7 Cells.

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Wang, Longqiong; Jing, Jinzhong; Yan, Hui; Tang, Jiayong; Jia, Gang; Liu, Guangmang; Chen, Xiaoling; Tian, Gang; Cai, Jingyi; Shang, Haiying; Zhao, Hua

2018-04-18

This study was conducted to profile selenoprotein encoding genes in mouse RAW264.7 cells upon lipopolysaccharide (LPS) challenge and integrate their roles into immunological regulation in response to selenium (Se) pretreatment. LPS was used to develop immunological stress in macrophages. Cells were pretreated with different levels of Se (0, 0.5, 1.0, 1.5, 2.0 μmol Se/L) for 2 h, followed by LPS (100 ng/mL) stimulation for another 3 h. The mRNA expression of 24 selenoprotein encoding genes and 9 inflammation-related genes were investigated. The results showed that LPS (100 ng/mL) effectively induced immunological stress in RAW264.7 cells with induced inflammation cytokines, IL-6 and TNF-α, mRNA expression, and cellular secretion. LPS increased (P immunological stress in RAW264.7 cells accompanied with the global downregulation of selenoprotein encoding genes and Se pretreatment alleviated immunological stress via upregulation of a subset of selenoprotein encoding genes.

The influence of age and repeated LPS administration on body temperature and the relation with interleukin-6 and IgM antibodies in broiler chickens

OpenAIRE

De Boever , Sandra; Beyaert , Rudi; Vandemaele , Fréderic; Baert , Kris; Duchateau , Luc; Goddeeris , Bruno; De Backer , Patrick; Croubels , Siska

2008-01-01

Abstract Our objective was to create a standardized and reproducible inflammation model in chickens in order to study the pharmacodynamics of several anti-pyretic and anti-inflammatory drugs. We studied the influence of age and repeated lipopolysaccharide (LPS) administration on body temperature and the correlation of this with concentrations of interleukin 6 (IL-6) and IgM antibodies against LPS in plasma of chickens. Three and five week old broilers were injected intravenously...

Atorvastatin reduces lipopolysaccharide-induced expression of cyclooxygenase-2 in human pulmonary epithelial cells

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Chen Ping

2005-04-01

Full Text Available Abstract Objective To explore the effects of atorvastatin on expression of cyclooxygenase-2 (COX-2 in human pulmonary epithelial cells (A549. Methods A549 cells were incubated in DMEM medium containing lipopolysaccharide (LPS in the presence or absence of atorvastatin. After incubation, the medium was collected and the amount of prostaglandin E2 (PGE2 was measured by enzyme-linked immunosorbent assay (ELISA. The cells were harvested, and COX-2 mRNA and protein were analyzed by RT-PCR and western-blot respectively. Results LPS increased the expression of COX-2 mRNA and production of PGE2 in a dose- and time-dependent manner in A549. Induction of COX-2 mRNA and protein by LPS were inhibited by atorvastatin in a dose-dependent manner. Atorvastatin also significantly decreased LPS-induced production of PGE2. There was a positive correlation between reduced of COX-2 mRNA and decreased of PGE2 (r = 0.947, P Conclusion Atorvastatin down-regulates LPS-induced expression of the COX-2 and consequently inhibits production of PGE2 in cultured A549 cells.

The LPS-induced neutrophil recruitment into rat air pouches is mediated by TNFα: likely macrophage origin

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C-D. Arreto

1997-01-01

Full Text Available The role of resident cells during the lipopolysaccharide (LPS-induced neutrophil recruitment into rat air pouches was investigated. In this model, LPS (Escherichia coli, O55: B5 strain; 2–2000 ng induced a dose– and time-dependent neutrophil recruitment accompanied by the generation of a tumour necrosis factor-α (TNFα-like activity. Dexamethasone (0.05–5 mug and cycloheximide (6 ng, injected 2 h before LPS into the pouches, inhibited the neutrophil recruitment and the generation of the TNFα-like activity, while the H1-receptor antagonist mepyramine (1 and 4 mg/kg, i.p., 0.5 h before LPS and the PAF-receptor antagonist WEB 2170 (0.05 and 1 mg/kg, i.p., 0.5 h before LPS had no effect. Purified alveolar macrophages (AM were used to replenish the pouches of cycloheximide-treated recipient rats. AM provided by PBS-treated animals led to the recovery of the LPS-induced neutrophil recruitment and of the TNFα-like formation contrasting with those from cycloheximide-treated animals (1 mg/kg, i.p.. When delivered in situ, liposome-encapsulated clodronate, a macrophage depletor, significantly impaired both the LPSinduced neutrophil recruitment and the TNFα-like activity. An anti-murine TNFα polyclonal antibody (0.5 h before LPS was also effective. These results emphasize the pivotal role of macrophages for LPS-induced neutrophil recruitment via the formation of TNFα.

Lipopolysaccharide-binding protein and leptin are associated with stress-induced interleukin-6 cytokine expression ex vivo in obesity.

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Huang, Chun-Jung; Stewart, Jennifer K; Shibata, Yoshimi; Slusher, Aaron L; Acevedo, Edmund O

2015-05-01

Obesity is associated with enhanced inflammation and mental stress, but limited information has addressed the potential additive effect of psychological stress on obesity-associated inflammation. This study examined whether obese subjects would elicit a greater host immune response (IL-6 mRNA and cytokine) to lipopolysaccharide (LPS) in response to mental stress. Blood samples for LPS-stimulated IL-6 mRNA and cytokine were collected prior to and following mental stress. Results showed that obese subjects elicited a greater LPS-induced IL-6 along with its mRNA expression following mental stress compared to normal-weight subjects. Stress-induced IL-6 cytokine response to LPS was correlated with the baseline levels of plasma LPS binding protein (LBP) and leptin. These findings are consistent with the idea that endogenous inflammatory agents (e.g., LBP and leptin), often elevated with obesity, enhance inflammatory responses to psychological stress. © 2014 Society for Psychophysiological Research.

Effect of threonine on secretory immune system using a chicken intestinal ex vivo model with lipopolysaccharide challenge

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Secretory IgA (sIgA) and its transcytosis receptor, polymeric immunoglobulin receptor (pIgR), along with mucus, form the first lines of intestinal defense. Threonine (Thr) is a major constituent component of intestinal mucins and IgA, which are highly secreted under lipopolysaccharide (LPS) induced ...

Methyl jasmonate attenuated lipopolysaccharide-induced depressive-like behaviour in mice.

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Adebesin, Adaeze; Adeoluwa, Olusegun A; Eduviere, Anthony T; Umukoro, Solomon

2017-11-01

Depression is a recurrent neuropsychiatric disorder that affects millions of individuals worldwide and impact negatively on the patients' social functions and quality of life. Studies have shown that i.p injection of lipopolysaccharide (LPS) induces depressive-like behavior in rodents via induction of oxidative stress and neuroinflammation. Methyl jasmonate (MJ), an isolated compound from jasmine plant has gained reputation in aromatherapy for treatment of depression, nervousness and memory deficits. This study was designed to evaluate the effects of MJ on LPS-induced depressive-like behavior in mice. Mice were given MJ (5-20 mg/kg), imipramine (10 mg/kg) or vehicle (10 mL/kg) intraperitoneally for 7 consecutive days. On day 7, treatment was carried out 30 min prior to i.p injection of LPS (830 μg/kg). Twenty four hours after LPS administration, tail suspension, forced swim and sucrose preference tests were carried out. Thereafter, serum corticosterone levels were determined using ELISA. The levels of malondialdehyde (MDA), glutathione (GSH) and tumor necrosis factor-alpha (TNF-α) were determined in brain tissue homogenates. LPS significantly increased immobility time in the tail suspension and forced swim tests when compared with vehicle (p < 0.05), which indicates depressive-like syndromes. However, the increased immobility time was significantly reduced by MJ (5-20 mg/kg) when compared with LPS-treated group. LPS administration also altered the levels of MDA, GSH, corticosterone and TNF alpha in mice, which was significantly reversed by MJ. These findings suggest that attenuation of LPS-induced depressive-like behavior by MJ may be related to suppression of oxidative stress and release of TNF alpha. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vildagliptin ameliorates pulmonary fibrosis in lipopolysaccharide-induced lung injury by inhibiting endothelial-to-mesenchymal transition.

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Suzuki, Toshio; Tada, Yuji; Gladson, Santhi; Nishimura, Rintaro; Shimomura, Iwao; Karasawa, Satoshi; Tatsumi, Koichiro; West, James

2017-10-16

Pulmonary fibrosis is a late manifestation of acute respiratory distress syndrome (ARDS). Sepsis is a major cause of ARDS, and its pathogenesis includes endotoxin-induced vascular injury. Recently, endothelial-to-mesenchymal transition (EndMT) was shown to play an important role in pulmonary fibrosis. On the other hand, dipeptidyl peptidase (DPP)-4 was reported to improve vascular dysfunction in an experimental sepsis model, although whether DPP-4 affects EndMT and fibrosis initiation during lipopolysaccharide (LPS)-induced lung injury is unclear. The aim of this study was to investigate the anti-EndMT effects of the DPP-4 inhibitor vildagliptin in pulmonary fibrosis after systemic endotoxemic injury. A septic lung injury model was established by intraperitoneal injection of lipopolysaccharide (LPS) in eight-week-old male mice (5 mg/kg for five consecutive days). The mice were then treated with vehicle or vildagliptin (intraperitoneally, 10 mg/kg, once daily for 14 consecutive days from 1 day before the first administration of LPS.). Flow cytometry, immunohistochemical staining, and quantitative polymerase chain reaction (qPCR) analysis was used to assess cell dynamics and EndMT function in lung samples from the mice. Lung tissue samples from treated mice revealed obvious inflammatory reactions and typical interstitial fibrosis 2 days and 28 days after LPS challenge. Quantitative flow cytometric analysis showed that the number of pulmonary vascular endothelial cells (PVECs) expressing alpha-smooth muscle actin (α-SMA) or S100 calcium-binding protein A4 (S100A4) increased 28 days after LPS challenge. Similar increases in expression were also confirmed by qPCR of mRNA from isolated PVECs. EndMT cells had higher proliferative activity and migration activity than mesenchymal cells. All of these changes were alleviated by intraperitoneal injection of vildagliptin. Interestingly, vildagliptin and linagliptin significantly attenuated EndMT in the absence of immune

Pseudomonas aeruginosa lipopolysaccharide induces CF-like alteration of protein secretion by human tracheal gland cells.

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Kammouni, W; Figarella, C; Baeza, N; Marchand, S; Merten, M D

1997-12-18

Human tracheal gland (HTG) serous cells are now believed to play a major role in the physiopathology of cystic fibrosis. Because of the persistent inflammation and the specific infection by Pseudomonas aeruginosa in the lung, we looked for the action of the lipopolysaccharide (LPS) of this bacteria on human tracheal gland cells in culture by studying the secretion of the secretory leukocyte proteinase inhibitor (SLPI) which is a specific serous secretory marker of these cells. Treatment with Pseudomonas aeruginosa LPS resulted in a significant dose-dependent increase in the basal production of SLPI (+ 250 +/- 25%) whilst the SLPI transcript mRNA levels remained unchanged. This LPS-induced increase in secretion was inhibited by glucocorticoides. Furthermore, LPS treatment of HTG cells induces a loss of responsiveness to carbachol and isoproterenol but not to adenosine triphosphate. These findings indicate that HTG cells treated by Pseudomonas aeruginosa LPS have the same behavior as those previously observed with CF-HTG cells. Exploration by using reverse transcriptase polymerase chain reaction amplification showed that LPS downregulated cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression in HTG cells indicative of a link between CFTR function and consequent CF-like alteration in protein secretory process.

[Effect of lipopolysaccharides extracted from Porphyromonas endodontalis on the expression of CD14 in osteoblast].

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Jia, Ge; Qiu, Li-hong; Li, Ren; Yang, Di; Guo, Yan

2010-10-01

To investigate the effect of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of CD14 in osteoblast. Under the condition with or without serum, MC3T3-E1 cells were stimulated with 10 μg/mL P.e-LPS for 24 hours, then the expression of CD14 was measured using flow cytometry; the membrane CD14 mRNA was detected at different time point (0, 1, 3, 6, 12, 24 h) by RT-PCR. Statistical analysis was performed using two-sample t test, one-way ANOVA and Dunnett t test with SPSS13.0 software package. Flow cytometry showed that CD14 protein increased after the stimulation of P.e-LPS for 24 h, while the non-serum group demonstrated more increase; the membrane CD14 mRNA level was up-regulated by 10 μg/mL P.e-LPS at 1 hour, and reached the maximum at 3 h and declined after 6 h. P.e-LPS can induce the expression of CD14 in osteoblast MC3T3-E1, which indicates that P.e-LPS may play an important role in osteoblast through CD14.

Structural insights into the dual strategy of recognition by peptidoglycan recognition protein, PGRP-S: structure of the ternary complex of PGRP-S with lipopolysaccharide and stearic acid.

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Pradeep Sharma

Full Text Available Peptidoglycan recognition proteins (PGRPs are part of the innate immune system. The 19 kDa Short PGRP (PGRP-S is one of the four mammalian PGRPs. The concentration of PGRP-S in camel (CPGRP-S has been shown to increase considerably during mastitis. The structure of CPGRP-S consists of four protein molecules designated as A, B, C and D forming stable intermolecular contacts, A-B and C-D. The A-B and C-D interfaces are located on the opposite sides of the same monomer leading to the the formation of a linear chain with alternating A-B and C-D contacts. Two ligand binding sites, one at C-D contact and another at A-B contact have been observed. CPGRP-S binds to the components of bacterial cell wall molecules such as lipopolysaccharide (LPS, lipoteichoic acid (LTA, and peptidoglycan (PGN from both gram-positive and gram-negative bacteria. It also binds to fatty acids including mycolic acid of the Mycobacterium tuberculosis (Mtb. Previous structural studies of binary complexes of CPGRP-S with LPS and stearic acid (SA have shown that LPS binds to CPGRP-S at C-D contact (Site-1 while SA binds to it at the A-B contact (Site-2. The binding studies using surface plasmon resonance showed that LPS and SA bound to CPGRP-S in the presence of each other. The structure determination of the ternary complex showed that LPS and SA bound to CPGRP-S at Site-1 and Site-2 respectively. LPS formed 13 hydrogen bonds and 159 van der Waals contacts (distances ≤4.2 Å while SA formed 56 van der Waals contacts. The ELISA test showed that increased levels of productions of pro-inflammatory cytokines TNF-α and IFN-γ due to LPS and SA decreased considerably upon the addition of CPGRP-S.

Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages

OpenAIRE

M. Allegra; F. D’Acquisto; L. Tesoriere; A. Attanzio; M.A. Livrea

2014-01-01

Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia ...

Study of monocyte membrane proteome perturbation during lipopolysaccharide-induced tolerance using iTRAQ-based quantitative proteomic approach

KAUST Repository

Zhang, Huoming

2010-07-02

Human monocytes\\' exposure to low-level lipopolysaccharide (LPS) induces temporary monocytic insensitivity to subsequent LPS challenge. The underlying mechanism of this phenomenon could have important clinical utilities in preventing and/or treating severe infections. In this study, we used an iTRAQ-based quantitative proteomic approach to comprehensively characterize the membrane proteomes of monocytes before and after LPS exposure. We identified a total of 1651 proteins, of which 53.6% were membrane proteins. Ninety-four percent of the proteins were quantified and 255 proteins were shown to be tightly regulated by LPS. Subcellular location analysis revealed organelle-specific response to LPS exposure: more than 90% of identified mitochondrial membrane proteins were significant downregulated, whereas the majority of proteins from other organelles such as ER, Golgi and ribosome were upregulated. Moreover, we found that the expression of most receptors potentially involved in LPS signal pathway (CD14, toll-like receptor 4, CD11/CD18 complex) were substantially decreased, while the expression of molecules involved in LPS neutralization were enhanced after LPS challenge. Together, these findings could be of significance in understanding the mechanism of LPS tolerance and provide values for designing new approaches for regulating monocytic responses in sepsis patients.

Study of monocyte membrane proteome perturbation during lipopolysaccharide-induced tolerance using iTRAQ-based quantitative proteomic approach

KAUST Repository

Zhang, Huoming; Zhao, Changqing; Li, Xin; Zhu, Yi; Gan, Chee Sian; Wang, Yong; Ravasi, Timothy; Qian, Pei-Yuan; Wong, Siew Cheng; Sze, Siu Kwan

2010-01-01

Human monocytes' exposure to low-level lipopolysaccharide (LPS) induces temporary monocytic insensitivity to subsequent LPS challenge. The underlying mechanism of this phenomenon could have important clinical utilities in preventing and/or treating severe infections. In this study, we used an iTRAQ-based quantitative proteomic approach to comprehensively characterize the membrane proteomes of monocytes before and after LPS exposure. We identified a total of 1651 proteins, of which 53.6% were membrane proteins. Ninety-four percent of the proteins were quantified and 255 proteins were shown to be tightly regulated by LPS. Subcellular location analysis revealed organelle-specific response to LPS exposure: more than 90% of identified mitochondrial membrane proteins were significant downregulated, whereas the majority of proteins from other organelles such as ER, Golgi and ribosome were upregulated. Moreover, we found that the expression of most receptors potentially involved in LPS signal pathway (CD14, toll-like receptor 4, CD11/CD18 complex) were substantially decreased, while the expression of molecules involved in LPS neutralization were enhanced after LPS challenge. Together, these findings could be of significance in understanding the mechanism of LPS tolerance and provide values for designing new approaches for regulating monocytic responses in sepsis patients.

Innate immune activation by inhaled lipopolysaccharide, independent of oxidative stress, exacerbates silica-induced pulmonary fibrosis in mice.

Directory of Open Access Journals (Sweden)

David M Brass

Full Text Available Acute exacerbations of pulmonary fibrosis are characterized by rapid decrements in lung function. Environmental factors that may contribute to acute exacerbations remain poorly understood. We have previously demonstrated that exposure to inhaled lipopolysaccharide (LPS induces expression of genes associated with fibrosis. To address whether exposure to LPS could exacerbate fibrosis, we exposed male C57BL/6 mice to crystalline silica, or vehicle, followed 28 days later by LPS or saline inhalation. We observed that mice receiving both silica and LPS had significantly more total inflammatory cells, more whole lung lavage MCP-1, MIP-2, KC and IL-1β, more evidence of oxidative stress and more total lung hydroxyproline than mice receiving either LPS alone, or silica alone. Blocking oxidative stress with N-acetylcysteine attenuated whole lung inflammation but had no effect on total lung hydroxyproline. These observations suggest that exposure to innate immune stimuli, such as LPS in the environment, may exacerbate stable pulmonary fibrosis via mechanisms that are independent of inflammation and oxidative stress.

Cytosolic NADP(+)-dependent isocitrate dehydrogenase protects macrophages from LPS-induced nitric oxide and reactive oxygen species.

Science.gov (United States)

Maeng, Oky; Kim, Yong Chan; Shin, Han-Jae; Lee, Jie-Oh; Huh, Tae-Lin; Kang, Kwang-il; Kim, Young Sang; Paik, Sang-Gi; Lee, Hayyoung

2004-04-30

Macrophages activated by microbial lipopolysaccharides (LPS) produce bursts of nitric oxide and reactive oxygen species (ROS). Redox protection systems are essential for the survival of the macrophages since the nitric oxide and ROS can be toxic to them as well as to pathogens. Using suppression subtractive hybridization (SSH) we found that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) is strongly upregulated by nitric oxide in macrophages. The levels of IDPc mRNA and of the corresponding enzymatic activity were markedly increased by treatment of RAW264.7 cells or peritoneal macrophages with LPS or SNAP (a nitric oxide donor). Over-expression of IDPc reduced intracellular peroxide levels and enhanced the survival of H2O2- and SNAP-treated RAW264.7 macrophages. IDPc is known to generate NADPH, a cellular reducing agent, via oxidative decarboxylation of isocitrate. The expression of enzymes implicated in redox protection, superoxide dismutase (SOD) and catalase, was relatively unaffected by LPS and SNAP. We propose that the induction of IDPc is one of the main self-protection mechanisms of macrophages against LPS-induced oxidative stress.

Obeticholic acid protects mice against lipopolysaccharide-induced liver injury and inflammation.

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Xiong, Xi; Ren, Yuqian; Cui, Yun; Li, Rui; Wang, Chunxia; Zhang, Yucai

2017-12-01

Cholestasis, as a main manifestation, induces liver injury during sepsis. The farnesoid X receptor (FXR) plays an important role in regulating bile acid homeostasis. Whether FXR activation by its agonist obeticholic acid (OCA) is contributed to improve sepsis-induced liver injury remains unknown. The aim of the present study was to investigate the effect of OCA on lipopolysaccharide (LPS)-induced acute liver injury in mice. 8-week old male C57BL/6J mice were randomly divided into control group, LPS group, oral OCA group and LPS plus oral OCA (LPS + OCA) group. The serum and livers were collected for further analysis. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA) and total bilirubin (TBIL) were measured at indicated time after LPS administration. Liver sections were stained with hematoxylin & eosin (H&E). Orally OCA pretreatment stimulated the expression of FXR and BSEP in livers and protected mice from LPS-induced hepatocyte apoptosis and inflammatory infiltration. Consistently, LPS-induced higher serum levels of ALT, AST, TBA and TBIL were significantly reversed by OCA administration. Meanwhile, the mRNA levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α) and IL-6 were decreased in livers of mice in LPS + OCA group compared with LPS group. Further investigation indicated that the higher expression of ATF4 and LC3II/I were associated with the protective effect of OCA on LPS-induced liver injury. Orally OCA pretreatment protects mice from LPS-induced liver injury possibly contributed by improved bile acid homeostasis, decreased inflammatory factors and ATF4-mediated autophagy activity in hepatocytes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Capture of lipopolysaccharide (endotoxin) by the blood clot: a comparative study.

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Armstrong, Margaret T; Rickles, Frederick R; Armstrong, Peter B

2013-01-01

In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot) and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse) operate to capture lipopolysaccharide (LPS, endotoxin). The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL) test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

Capture of lipopolysaccharide (endotoxin by the blood clot: a comparative study.

Directory of Open Access Journals (Sweden)

Margaret T Armstrong

Full Text Available In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse operate to capture lipopolysaccharide (LPS, endotoxin. The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

Proinflammatory effects of bacterial lipoprotein on human neutrophil activation status, function and cytotoxic potential in vitro.

LENUS (Irish Health Repository)

Power, C

2012-02-03

Bacterial lipoprotein (BLP) is the most abundant protein in gram-negative bacterial cell walls, heavily outweighing lipopolysaccharide (LPS). Herein we present findings demonstrating the potent in vitro effects of BLP on neutrophil (PMN) activation status, function, and capacity to transmigrate an endothelial monolayer. PMNs are the principal effectors of the initial host response to injury or infection and constitute a significant threat to invading bacterial pathogens. The systemic inflammatory response syndrome (SIRS) is characterised by significant host tissue injury mediated, in part, by uncontrolled regulation of PMN cytotoxic activity. We found that BLP-activated human PMN as evidenced by increased CD11b\\/CD18 (Mac-1) expression. Up-regulation of PMN Mac-1 in response to BLP occurred independently of membrane-bound CD14 (mCD14). A similar up-regulation of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells was observed whilst E-Selectin expression was unaffected. PMN transmigration across a human umbilical vein endothelial cell (HUVEC) monolayer was markedly increased after treating either PMN\\'s or HUVEC independently with BLP. This increased transmigration did not occur as a result of any direct effect of BLP on HUVEC monolayer permeability, assessed objectively using the passage of FITC-labeled Dextran-70. BLP primed PMN for enhanced respiratory burst and superoxide anion production in response to PMA, but did not influence phagocytosis of opsonized Escherichia coli. BLP far exceeds LPS as a gram-negative bacterial wall component, these findings therefore implicate BLP as an additional putative mediator of SIRS arising from gram-negative infection.

An O antigen capsule modulates bacterial pathogenesis in Shigella sonnei.

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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.

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.

Concurrent administration effect of antibiotic and anti-inflammatory drugs on the immunotoxicity of bacterial endotoxins.

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El Amir, Azza M; Tanious, Dalia G; Mansour, Hanaa A

2017-11-01

Pseudomonas aeruginosa (P. aeruginosa) is a gram-negative bacterium that causes a variety of diseases in compromised hosts. Bacterial endotoxins such as lipopolysaccharide (LPS) are the major outer surface membrane components that are present in almost all gram-negative bacteria and act as extremely strong stimulators of innate immunity and inflammation of the airway. This study was undertaken to determine the effect of combined administration of Gentamicin (GENT) as an antibiotic and Dexamethasone (DEXA) as an anti-inflammatory drug on some immunological and histological parameters. After determination of LD 50 of P. aeruginosa, mice groups were injected with DEXA, GENT and lipopolysaccharide alone or in combination. Lipopolysaccharide single injection caused a significant increase of total leukocyte count, lymphocytes, neutrophils and levels of IgM and IgG. DEXA induced an increase of neutrophilia and lymphopenia. Immunological examination demonstrated that combined treatment has a significant effect of decreasing lymphocytes and IgG levels than single treatment does. Histological examination demonstrated that the inflammation of thymus, spleen, lymph node and liver decreases in mice that received combined treatment than those that received individual treatment. Concurrent administration of DEXA and GENT has a great effect on protecting organs against damage in case of endotoxemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Cell surface physico chemistry alters biofilm development of Pseudomonas aeruginosa lipopolysaccharide mutants

NARCIS (Netherlands)

Flemming, CA; Palmer, RJ; Arrage, AA; van der Mei, H.C.; White, DC

1999-01-01

The hydrophobic and electrostatic characteristics of bacterial cell surfaces were compared with attachment proclivity and biomass accumulation over time between wildtype Pseudomonas aeruginosa serotype O6 (possesses A and B band LPS), and three LPS-deficient mutants, vi;. A28 (A(+)B(-)), R5

Cardiac-Specific Overexpression of Catalase Attenuates Lipopolysaccharide-Induced Myocardial Contractile Dysfunction: Role of Autophagy

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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 with LPS (6 mg/kg) and cardiac function was evaluated. Levels of oxidative stress, autophagy, apoptosis and protein damage were examined using fluorescence microscopy, Western blot, TUNEL assay, caspase-3 activity and carbonyl formation. Kaplan-Meier curve was constructed for survival following LPS treatment. Our results revealed a lower mortality in catalase mice compared with FVB mice following LPS challenge. LPS injection led to depressed cardiac contractile capacity as evidenced by echocardiography and cardiomyocyte contractile function, the effect of which was ablated by catalase overexpression. LPS treatment induced elevated TNF-α level, autophagy, apoptosis (TUNEL, caspase-3 activation, cleaved caspase-3), production of ROS and O2−, and protein carbonyl formation, the effects of which were significantly attenuated by catalase overexpression. Electron microscopy revealed focal myocardial damage characterized by mitochondrial injury following LPS treatment, which was less severe in catalase mice. Interestingly, LPS-induced cardiomyocyte contractile dysfunction was prevented by antioxidant NAC and the autophagy inhibitor 3-methyladenine. Taken together, our data revealed that catalase protects against LPS-induced cardiac dysfunction and mortality, which may be associated with inhibition of oxidative stress and autophagy. PMID:22902401

Hyperin protects against LPS-induced acute kidney injury by inhibiting TLR4 and NLRP3 signaling pathways

Science.gov (United States)

Chunzhi, Gong; Zunfeng, Li; Chengwei, Qin; Xiangmei, Bu; Jingui, Yu

2016-01-01

Hyperin is a flavonoid compound derived from Ericaceae, Guttifera, and Celastraceae that has been shown to have various biological effects, such as anti-inflammatory and anti-oxidant effects. However, there is no evidence to show the protective effects of hyperin on lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Therefore, we investigated the protective effects and mechanism of hyperin on LPS-induced AKI in mice. The levels of TNF-α, IL-6, and IL-1β were tested by ELISA. The effects of hyperin on blood urea nitrogen (BUN) and serum creatinine were also detected. In addition, the expression of TLR4, NF-κB, and NLRP3 were detected by western blot analysis. The results showed that hyperin significantly inhibited LPS-induced TNF-α, IL-6, and IL-1β production. The levels of BUN and creatinine were also suppressed by hyperin. Furthermore, LPS-induced TLR4 expression and NF-κB activation were also inhibited by hyperin. In addition, treatment of hyperin dose-dependently inhibited LPS-induced NLRP3 signaling pathway. In conclusion, the results showed that hyperin inhibited LPS-induced inflammatory response by inhibiting TLR4 and NLRP3 signaling pathways. Hyperin has potential application prospects in the treatment of sepsis-induced AKI. PMID:27813491

Over-expression and siRNA of a novel environmental lipopolysaccharide-responding gene on the cell cycle of the human hepatoma-derived cell line HepG2

International Nuclear Information System (INIS)

Du Kejun; Chai Yubo; Hou Lichao; Chang Wenhui; Chen Suming; Luo Wenjing; Cai Tongjian; Zhang Xiaonan; Chen Nanchun; Chen Yaoming; Chen Jingyuan

2008-01-01

Lipopolysaccharide (LPS) is the toxic determinant for Gram-negative bacterium infection. The individual response to LPS was related to its gene background. It is necessary to identify new molecules and signaling transduction pathways about LPS. The present study was undertaken to evaluate the effects of a novel environmental lipopolysaccharide-responding (Elrg) gene on the regulation of proliferation and cell cycle of the hepatoma-derived cell line, HepG2. By means of RT-PCR, the new molecule of Elrg was generated from a human dental pulp cell cDNA library. Expression level of Elrg in HepG2 cells was remarkably upgraded by the irritation of LPS. Localization of Elrg in HepG2 cells was positioned mainly in cytoplasm. HepG2 cells were markedly arrested in the G1 phase by over-expressing Elrg. The percentage of HepG2 cells in G1 phase partly decreased after Elrg-siRNA. In conclusion, Elrg is probably correlative with LPS responding. Elrg is probably a new protein in cytoplasm which plays an important role in regulating cell cycle. The results will deepen our understanding about the potential effects of Elrg on the human hepatoma-derived cell line HepG2

Inhibitory mechanism of chroman compound on LPS-induced nitric oxide production and nuclear factor-κB activation

International Nuclear Information System (INIS)

Kim, Byung Hak; Reddy, Alavala Matta; Lee, Kum-Ho; Chung, Eun Yong; Cho, Sung Min; Lee, Heesoon; Min, Kyung Rak; Kim, Youngsoo

2004-01-01

6-Hydroxy-7-methoxychroman-2-carboxylic acid phenylamide (KL-1156) is a novel chemically synthetic compound. In the present study, the chroman KL-1156 compound was found to inhibit lipopolysaccharide (LPS)-induced nitric oxide production in macrophages RAW 264.7. KL-1156 compound attenuated LPS-induced synthesis of both mRNA and protein of inducible nitric oxide synthase (iNOS), in parallel, and inhibited LPS-induced iNOS promoter activity, indicating that the chroman compound down-regulated iNOS expression at transcription level. As a mechanism of the anti-inflammatory action shown by KL-1156 compound, suppression of nuclear factor (NF)-κB has been documented. KL-1156 compound exhibited a dose-dependent inhibitory effect on LPS-induced NF-κB transcriptional activity in macrophages RAW 264.7. Furthermore, the compound inhibited LPS-induced nuclear translocation of NF-κB p65 and DNA binding activity of NF-κB complex, in parallel, but did not affect IκBα degradation. Taken together, this study demonstrated that chroman KL-1156 compound interfered with nuclear translocation step of NF-κB p65, which was attributable to its anti-inflammatory action

Antioxidant and anti-inflammatory effects of cauliflower leaf powder-enriched diet against LPS induced toxicity in rabbits.

Science.gov (United States)

Larocca, Marilena; Perna, Anna Maria; Simonetti, Amalia; Gambacorta, Emilio; Iannuzzi, Alessandra; Perucatti, Angela; Rossano, Rocco

2017-09-20

Brassica phytochemicals exert a broad spectrum of health-promoting activities. The aim of this study was to investigate the possible beneficial effects of a cauliflower leaf powder (CLP)-enriched diet to prevent inflammation and oxidative stress resulting from injection of lipopolysaccharide (LPS) into rabbits. Animals (24 rabbits) were randomly divided into two groups and fed with a standard diet (SD) or a standard diet supplemented with a 100 g kg -1 diet of CLP. After 60 days, six rabbits of both groups received a LPS injection (100 μg per kg body weight). Serum samples collected after 90 min of LPS injection were assessed for their content of both inflammatory biomarkers such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and matrix-metalloproteinases (MMP-2 and MMP-9) and oxidative stress biomarkers such as thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). LPS increased the levels of TNF-α, IL-6, and TBARS as well as MMP-2 and MMP-9 activities, whereas it decreased the GSH levels and SOD and CAT activities. In conclusion, preventive supplementation with CLP can protect rabbits from the inflammation and oxidative stress induced by LPS.

Teuvincenone F Suppresses LPS-Induced Inflammation and NLRP3 Inflammasome Activation by Attenuating NEMO Ubiquitination

OpenAIRE

Xibao Zhao; Xibao Zhao; Debing Pu; Debing Pu; Zizhao Zhao; Huihui Zhu; Hongrui Li; Hongrui Li; Yaping Shen; Xingjie Zhang; Ruihan Zhang; Jianzhong Shen; Weilie Xiao; Weilie Xiao; Weilin Chen

2017-01-01

Inflammation causes many diseases that are serious threats to human health. However, the molecular mechanisms underlying regulation of inflammation and inflammasome activation are not fully understood which has delayed the discovery of new anti-inflammatory drugs of urgent clinic need. Here, we found that the natural compound Teuvincenone F, which was isolated and purified from the stems and leaves of Premna szemaoensis, could significantly inhibit lipopolysaccharide (LPS)–induced pro-inflamm...

Teuvincenone F Suppresses LPS-Induced Inflammation and NLRP3 Inflammasome Activation by Attenuating NEMO Ubiquitination

OpenAIRE

Zhao, Xibao; Pu, Debing; Zhao, Zizhao; Zhu, Huihui; Li, Hongrui; Shen, Yaping; Zhang, Xingjie; Zhang, Ruihan; Shen, Jianzhong; Xiao, Weilie; Chen, Weilin

2017-01-01

Inflammation causes many diseases that are serious threats to human health. However, the molecular mechanisms underlying regulation of inflammation and inflammasome activation are not fully understood which has delayed the discovery of new anti-inflammatory drugs of urgent clinic need. Here, we found that the natural compound Teuvincenone F, which was isolated and purified from the stems and leaves of Premna szemaoensis, could significantly inhibit lipopolysaccharide (LPS)?induced pro-inflamm...

Leptin potentiates Prevotella intermedia lipopolysaccharide-induced production of TNF-alpha in monocyte-derived macrophages.

Science.gov (United States)

Kim, Sung-Jo

2010-06-01

In addition to regulating body weight, leptin is also recognized for its role in the regulation of immune function and inflammation. The purpose of this study was to investigate the effect of leptin on Prevotella (P.) intermedia lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha production in differentiated THP-1 cells, a human monocytic cell line. LPS from P. intermedia ATCC 25611 was prepared by the standard hot phenol-water method. THP-1 cells were incubated in the medium supplemented with phorbol myristate acetate to induce differentiation into macrophage-like cells. The amount of TNF-alpha and interleukin-8 secreted into the culture medium was determined by enzyme-linked immunosorbent assay (ELISA). TNF-alpha and Ob-R mRNA expression levels were determined by semi-quantitative reverse transcription-polymerase chain reaction analysis. Leptin enhanced P. intermedia LPS-induced TNF-alpha production in a dose-dependent manner. Leptin modulated P. intermedia LPS-induced TNF-alpha expression predominantly at the transcriptional level. Effect of leptin on P. intermedia LPS-induced TNF-alpha production was not mediated by the leptin receptor. The ability of leptin to enhance P. intermedia LPS-induced TNF-alpha production may be important in the establishment of chronic lesion accompanied by osseous tissue destruction observed in inflammatory periodontal disease.

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.

Paeonol attenuates lipopolysaccharide-induced depressive-like behavior in mice.

Science.gov (United States)

Tao, Weiwei; Wang, Hanqing; Su, Qiang; Chen, Yanyan; Xue, Wenda; Xia, Baomei; Duan, Jinao; Chen, Gang

2016-04-30

The present study was designed to detect the anti-depressant effects of paeonol and the possible mechanisms in the lipopolysaccharide-induced depressive-like behavior. Open-field test(OFT), tail suspension test(TST) and forced swimming test(FST) were used to evaluate the behavioral activity. The contents of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in mice hippocampus were determined by HPLC-ECD. Serum interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α levels were evaluated by enzyme-linked immunosorbent assay (ELISA). Our results showed that LPS significantly decreased the levels of 5-HT and NE in the hippocampus. LPS also reduced open-field activity, as well as increased immobility duration in FST and TST. Paeonol administration could effectively reverse the alterations in the concentrations of 5-HT, NE and reduce the IL-6 and TNF-α levels. Moreover, paeonol effectively downregulated brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB) and Nuclear factor-κB (NF-κB) in hippocampal. In conclusion, paeonol administration exhibited significant antidepressant-like effects in mice with LPS-induced depression. Copyright © 2016. Published by Elsevier Ireland Ltd.

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.

Equine colostral carbohydrates reduce lipopolysaccharide-induced inflammatory responses in equine peripheral blood mononuclear cells.

Science.gov (United States)

Vendrig, J C; Coffeng, L E; Fink-Gremmels, J

2012-12-01

Increasing evidence suggests that reactions to lipopolysaccharide (LPS), particularly in the gut, can be partly or completely mitigated by colostrum- and milk-derived oligosaccharides. Confirmation of this hypothesis could lead to the development of new therapeutic concepts. To demonstrate the influence of equine colostral carbohydrates on the inflammatory response in an in vitro model with equine peripheral blood mononuclear cells (PBMCs). Carbohydrates were extracted from mare colostrum, and then evaluated for their influence on LPS-induced inflammatory responses in PBMCs isolated from the same mares, mRNA expression of tumour necrosis factor-alpha, interleukin-6 and interleukin-10 was measured as well as the protein levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10). Equine colostral carbohydrates significantly reduced LPS-induced TNF-alpha protein at both times measured and significantly reduced LPS-induced TNF-alpha, IL-6 and IL-10 mRNA expression by PBMCs. Moreover, cell viability significantly increased in the presence of high concentrations of colostral carbohydrates. Carbohydrates derived from equine colostrum reduce LPS-induced inflammatory responses of equine PBMCs. Colostrum and milk-derived carbohydrates are promising candidates for new concepts in preventive and regenerative medicine.

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection

International Nuclear Information System (INIS)

Tsang, R.S.W.; Chau, P.Y.; Lam, S.K.

1981-01-01

Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique with 125 I labelled anti-immunoglobulin antibody. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM immunoglobulin levels and gave significantly higher anti-LPS and anti-protein antibody titres in all three major immunoglobulin classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titres to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titres measured by radioimmunoassay and the anti-O antibody titres measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed. (author)

HemoHIM, a herbal preparation, alleviates airway inflammation caused by cigarette smoke and lipopolysaccharide.

Science.gov (United States)

Shin, Na-Rae; Kim, Sung-Ho; Ko, Je-Won; Park, Sung-Hyeuk; Lee, In-Chul; Ryu, Jung-Min; Kim, Jong-Choon; Shin, In-Sik

2017-03-01

HemoHIM, herbal preparation has designed for immune system recovery. We investigated the anti-inflammatory effect of HemoHIM on cigarette smoke (CS) and lipopolysaccharide (LPS) induced chronic obstructive pulmonary disease (COPD) mouse model. To induce COPD, C57BL/6 mice were exposed to CS for 1 h per day (eight cigarettes per day) for 4 weeks and intranasally received LPS on day 26. HemoHIM was administrated to mice at a dose of 50 or 100 mg/kg 1h before CS exposure. HemoHIM reduced the inflammatory cell count and levels of tumor necrosis factor receptor (TNF)-α, interleukin (IL)-6 and IL-1β in the broncho-alveolar lavage fluid (BALF) induced by CS+LPS exposure. HemoHIM decreased the inflammatory cell infiltration in the airway and inhibited the expression of iNOS and MMP-9 and phosphorylation of Erk in lung tissue exposed to CS+LPS. In summary, our results indicate that HemoHIM inhibited a reduction in the lung inflammatory response on CS and LPS induced lung inflammation via the Erk pathway. Therefore, we suggest that HemoHIM has the potential to treat pulmonary inflammatory disease such as COPD.

Lipopolysaccharide administration in the dominant mouse destabilizes social hierarchy.

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Cohn, Daniel Wagner Hamada; Gabanyi, Ilana; Kinoshita, Denise; de Sá-Rocha, Luiz Carlos

2012-09-01

Sickness behavior is a set of behavioral changes that are part of an adaptive strategy to overcome infection. Mice that interact with conspecifics displaying sickness behavior also show relevant behavioral changes. In this work we sought to determine the role of sickness behavior display by a dominant mouse as a promoter of hierarchy instability. We treated the dominant mouse within a dyad with lipopolysaccharide (LPS) (400 μg/kg, i.p.) for three consecutive days and assessed social dominance behavior. Since elder animals display increased inflammatory responses and the behaviors toward conspecifics are influenced by kinship we also assessed whether kinship and age, might influence sickness related hierarchy instability. Our results show that administration of LPS in the dominant mouse promotes social instability within a dyad, and indicates that this instability could be influenced by kinship and age. Copyright © 2012 Elsevier B.V. All rights reserved.

Interleukin-10 Protection against Lipopolysaccharide-Induced Neuro-Inflammation and Neurotoxicity in Ventral Mesencephalic Cultures.

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Zhu, Yan; Chen, Xiao; Liu, Zhan; Peng, Yu-Ping; Qiu, Yi-Hua

2015-12-28

Interleukin (IL)-10, an anti-inflammatory cytokine, is expressed in the brain and can inhibit microglial activation. Herein, we utilized lipopolysaccharide (LPS)-induced inflammatory Parkinson's disease (PD) cell model to determine whether microglia and astrocytes are necessary targets for IL-10 neuroprotection. Primary ventral mesencephalic (VM) cultures with different composition of neurons, microglia and astrocytes were prepared. The cells were exposed to IL-10 (15, 50 or 150 ng/mL) 1 h prior to LPS (50 ng/mL) treatment. LPS induced dopaminergic and non-dopaminergic neuronal loss in VM cultures, VM neuron-enriched cultures, and neuron-microglia co-cultures, but not in neuron-astrocyte co-cultures. IL-10 reduced LPS-induced neuronal loss particularly in single VM neuron cultures. Pro-inflammatory mediators (TNF-α, IL-1β, inducible nitric oxide synthase and cyclooxygenase-2) were upregulated in both neuron-microglia and neuron-astrocyte co-cultures by LPS. In contrast, neurotrophic factors (brain-derived neurotrophic factor, insulin-like growth factor-1 or glial cell-derived neurotrophic factor) were downregulated in neuron-microglia co-cultures, but upregulated in neuron-astrocyte co-cultures by LPS. IL-10 reduced both the increase in production of the pro-inflammatory mediators and the decrease in production of the neurotrophic factors induced by LPS. These results suggest that astrocytes can balance LPS neurotoxicity by releasing more neurotrophic factors and that IL-10 exerts neuroprotective property by an extensive action including direct on neurons and indirect via inhibiting microglial activation.

Inhibition of LPS-induced splenocyte proliferation by ortho-substituted polychlorinated biphenyl congeners

International Nuclear Information System (INIS)

Smithwick, L. Ashley; Smith, Andrew; Quensen, John F.; Stack, Allison; London, Lucille; Morris, Pamela J.

2003-01-01

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants, and their ubiquitous nature has prompted studies of their potential health hazards. As a result of their lipophilic nature, PCBs accumulate in breast milk and subsequently affect the health of offspring of exposed individuals. Biological effects of PCBs in animals have mostly been attributed to coplanar congeners, although effects of ortho congeners also have been demonstrated. To investigate the relationship of immunotoxicity and chlorine substitution pattern, the effects of PCB congeners and mixtures of ortho and non-ortho-substituted constituents of Aroclor 1242 on splenocytes from C57B1/6 mice were examined. The immunotoxic endpoints investigated included splenocyte viability, lipopolysaccharide (LPS)-induced splenocyte proliferation, and LPS-induced antibody secretion. Congeners with multiple ortho chlorines preferentially inhibited splenocyte proliferation as compared with non- or mono-ortho-substituted congeners. However, mixtures of non- and mono-ortho-substituted congeners and multi-ortho-substituted congeners inhibited LPS-induced splenocyte proliferation and antibody secretion at similar concentrations. Exposure of splenocytes to these mixtures did not activate the aryl hydrocarbon receptor (AhR) signal transduction pathway. These results suggest individual multi-ortho-substituted congeners preferentially inhibit LPS-induced splenocyte proliferation, while congeners not exhibiting an effect individually may have additive effects in a mixture to produce an immunotoxic response through an AhR-independent pathway

Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

Energy Technology Data Exchange (ETDEWEB)

Tang, J.; Jiang, Y. [Southern Medical University, Nanfang Hospital, Department of Anesthesia, Guangzhou, China, Department of Anesthesia, Nanfang Hospital, Southern Medical University, Guangzhou (China); Tang, Y.; Chen, B. [Guangzhou General Hospital of Guangzhou Military Command, Department of Intensive Care Unit, Guangzhou, China, Department of Intensive Care Unit, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou (China); Sun, X. [Laboratory of Traditional Chinese Medicine Syndrome, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou (China); Su, L.; Liu, Z. [Guangzhou General Hospital of Guangzhou Military Command, Department of Intensive Care Unit, Guangzhou, China, Department of Intensive Care Unit, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou (China)

2013-06-25

Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6) was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS). In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries.

Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

International Nuclear Information System (INIS)

Tang, J.; Jiang, Y.; Tang, Y.; Chen, B.; Sun, X.; Su, L.; Liu, Z.

2013-01-01

Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6) was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS). In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries

Adrenaline stimulates the proliferation and migration of mesenchymal stem cells towards the LPS-induced lung injury.

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Wu, Xiaodan; Wang, Zhiming; Qian, Mengjia; Wang, Lingyan; Bai, Chunxue; Wang, Xiangdong

2014-08-01

Bone marrow-derived mesenchymal stem cells (BMSCs) could modulate inflammation in experimental lung injury. On the other hand, adrenergic receptor agonists could increase DNA synthesis of stem cells. Therefore, we investigated the therapeutic role of adrenaline-stimulated BMSCs on lipopolysaccharide (LPS)-induced lung injury. BMSCs were cultured with adrenergic receptor agonists or antagonists. Suspensions of lung cells or sliced lung tissue from animals with or without LPS-induced injury were co-cultured with BMSCs. LPS-stimulated alveolar macrophages were co-cultured with BMSCs (with adrenaline stimulation or not) in Transwell for 6 hrs. A preliminary animal experiment was conducted to validate the findings in ex vivo study. We found that adrenaline at 10 μM enhanced proliferation of BMSCs through both α- and β-adrenergic receptors. Adrenaline promoted the migration of BMSCs towards LPS-injured lung cells or lung tissue. Adrenaline-stimulated BMSCs decreased the inflammation of LPS-stimulated macrophages, probably through the expression and secretion of several paracrine factors. Adrenaline reduced the extent of injury in LPS-injured rats. Our data indicate that adrenaline-stimulated BMSCs might contribute to the prevention from acute lung injury through the activation of adrenergic receptors, promotion of proliferation and migration towards injured lung, and modulation of inflammation. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Starch source in high concentrate rations does not affect rumen pH, histamine and lipopolysaccharide concentrations in dairy cows

NARCIS (Netherlands)

Pilachai, R.; Schonewille, J.T.; Thamrongyoswittayakul, C.; Aiumlamai, S.; Wachirapakom, C.; Everts, H.; Hendriks, W.H.

2012-01-01

The replacement of ground corn by cassava meal on rumen pH, lipopolysaccharide (LPS) and histamine concentrations under typical Thai feeding conditions (high concentrate diets and rice straw as the sole source of roughage) was investigated. Four rumen-fistulated crossbred Holstein, non-pregnant, dry

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

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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...

Long-term impact of systemic bacterial infection on the cerebral vasculature and microglia

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Püntener Ursula

2012-06-01

Full Text Available Abstract Background Systemic infection leads to generation of inflammatory mediators that result in metabolic and behavioural changes. Repeated or chronic systemic inflammation leads to a state of innate immune tolerance: a protective mechanism against overactivity of the immune system. In this study, we investigated the immune adaptation of microglia and brain vascular endothelial cells in response to systemic inflammation or bacterial infection. Methods Mice were given repeated doses of lipopolysaccharide (LPS or a single injection of live Salmonella typhimurium. Inflammatory cytokines were measured in serum, spleen and brain, and microglial phenotype studied by immunohistochemistry. To assess priming of the innate immune response in the brain, mice were infected with Salmonella typhimurium and subsequently challenged with a focal unilateral intracerebral injection of LPS. Results Repeated systemic LPS challenges resulted in increased brain IL-1β, TNF-α and IL-12 levels, despite attenuated systemic cytokine production. Each LPS challenge induced significant changes in burrowing behaviour. In contrast, brain IL-1β and IL-12 levels in Salmonella typhimurium-infected mice increased over three weeks, with high interferon-γ levels in the circulation. Behavioural changes were only observed during the acute phase of the infection. Microglia and cerebral vasculature display an activated phenotype, and focal intracerebral injection of LPS four weeks after infection results in an exaggerated local inflammatory response when compared to non-infected mice. Conclusions These studies reveal that the innate immune cells in the brain do not become tolerant to systemic infection, but are primed instead. This may lead to prolonged and damaging cytokine production that may have a profound effect on the onset and/or progression of pre-existing neurodegenerative disease.

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

TNF-α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells.

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Shin, M R; Kang, S K; Kim, Y S; Lee, S Y; Hong, S C; Kim, E-C

2015-07-01

To assess whether SIRT1 and VEGF are responsible for tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS)-induced angiogenesis and to examine the molecular mechanism(s) of action in human dental pulp cells (HDPCs). Immortalized HDPCs obtained from Prof. Takashi Takata (Hiroshima University, Japan) were treated with LPS (1 μg mL(-1) ) and TNF-α (10 ng mL(-1) ) for 24 h. mRNA and protein levels were examined by RT-PCR and Western blotting, respectively. Migration and tube formation were examined in human umbilical vein endothelial cells (HUVECs). The data were analysed by one-way anova. Statistical analysis was performed at α = 0.05. LPS and TNF-α upregulated VEGF and SIRT1 mRNA and protein levels. Inhibition of SIRT1 activity by sirtinol and SIRT1 siRNA or inhibition of the VEGF receptor by CBO-P11 significantly attenuated LPS + TNF-α-stimulated MMPs production in HDPCs, as well as migration and tube formation in HUVECs (P disease. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The value of 99Tcm-HSA in monitoring acute lung injury induced by lipopolysaccharide in rats

International Nuclear Information System (INIS)

Fu Zhanli; Zhang Chunli; Wang Rongfu; Zhang Shengsuo; Xue Yun

2005-01-01

To evaluate the value of 99 Tc m labeled human serum albumin ( 99 Tc m -HSA) in monitoring acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rats, twenty adult Wistar rats are given 99 Tc m -HSA intravenously, and are randomly divided into four groups 30 min later. The control and LPS group are given intravenous injection of 0.9% saline and LPS 8 mg/kg respectively. The ketamine and aminoguanidine group are given intraperitoneal injection of ketamine 4 mg/kg and aminoguanidine 20 mg/kg respectively just 30 min after administration of LPS 8 mg/kg. All of the four group rats are killed by blood letting at 3 h post-injection of 99 Tc m -HSA. Pulmonary permeability index (PPI) and the ratio of lung wet weight and dry weight (W/D) is calculated. The results of PPI and W/D in control and LPS group are 95.58 ± 11.32 and 5.38 ± 0.24, 6.61 ± 0.18 and 4.19 ± 0.11, respectively. The PPI and W/D in LPS group are much higher than that in the control group (P 0.05). So 99 tc m -HSA is an effective tracer in monitoring ALI induced by LPS in rats. (authors)

Differential Cell Sensitivity between OTA and LPS upon Releasing TNF-α

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Lauy Al-Anati

2010-06-01

Full Text Available The release of tumor necrosis factor α (TNF-α by ochratoxin A (OTA was studied in various macrophage and non-macrophage cell lines and compared with E. coli lipopolysaccharide (LPS as a standard TNF-α release agent. Cells were exposed either to 0, 2.5 or 12.5 µmol/L OTA, or to 0.1 µg/mL LPS, for up to 24 h. OTA at 2.5 µmol/L and LPS at 0.1 µg/mL were not toxic to the tested cells as indicated by viability markers. TNF-a was detected in the incubated cell medium of rat Kupffer cells, peritoneal rat macrophages, and the mouse monocyte macrophage cell line J774A.1: TNF-a concentrations were 1,000 pg/mL, 1,560 pg/mL, and 650 pg/mL, respectively, for 2.5 µmol/L OTA exposure and 3,000 pg/mL, 2,600 pg/mL, and 2,115 pg/mL, respectively, for LPS exposure. Rat liver sinusoidal endothelial cells, rat hepatocytes, human HepG2 cells, and mouse L929 cells lacked any cytokine response to OTA, but showed a significant release of TNF-a after LPS exposure, with the exception of HepG2 cells. In non-responsive cell lines, OTA lacked both any activation of NF-κB or the translocation of activated NF-κB to the cell nucleus, i.e., in mouse L929 cells. In J774A.1 cells, OTA mediated TNF-a release via the pRaf/MEK 1/2–NF-κB and p38-NF-κB pathways, whereas LPS used pRaf/MEK 1/2-NF-κB, but not p38-NF-κB pathways. In contrast, in L929 cells, LPS used other pathways to activate NF-κB. Our data indicate that only macrophages and macrophage derived cells respond to OTA and are considered as sources for TNF-a release upon OTA exposure.

Prenatal zinc reduces stress response in adult rat offspring exposed to lipopolysaccharide during gestation.

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Galvão, Marcella C; Chaves-Kirsten, Gabriela P; Queiroz-Hazarbassanov, Nicolle; Carvalho, Virgínia M; Bernardi, Maria M; Kirsten, Thiago B

2015-01-01

Previous investigations by our group have shown that prenatal treatment with lipopolysaccharide (LPS; 100 μg/kg, intraperitoneally) on gestation day (GD) 9.5 in rats, which mimics infections by Gram-negative bacteria, induces short- and long-term behavioral and neuroimmune changes in the offspring. Because LPS induces hypozincemia, dams were treated with zinc after LPS in an attempt to prevent or ameliorate the impairments induced by prenatal LPS exposure. LPS can also interfere with hypothalamic-pituitary-adrenal (HPA) axis development; thus, behavioral and neuroendocrine parameters linked to HPA axis were evaluated in adult offspring after a restraint stress session. We prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on GD 9.5). One hour later they received zinc (ZnSO4, 2 mg/kg, subcutaneously). Adult female offspring that were in metestrus/diestrus were submitted to a 2 h restraint stress session. Immediately after the stressor, 22 kHz ultrasonic vocalizations, open field behavior, serum corticosterone and brain-derived neurotrophic factor (BDNF) levels, and striatal and hypothalamic neurotransmitter and metabolite levels were assessed. Offspring that received prenatal zinc after LPS presented longer periods in silence, increased locomotion, and reduced serum corticosterone and striatal norepinephrine turnover compared with rats treated with LPS and saline. Prenatal zinc reduced acute restraint stress response in adult rats prenatally exposed to LPS. Our findings suggest a potential beneficial effect of prenatal zinc, in which the stress response was reduced in offspring that were stricken with infectious/inflammatory processes during gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

Fisetin administration improves LPS-induced acute otitis media in mouse in vivo

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Li, Peng; Chen, Dan; Huang, Yang

2018-01-01

Acute otitis media is one of the most common infectious diseases worldwide in spite of the widespread vaccination. The present study was conducted to explore the effects of fisetin on mouse acute otitis media models. The animal models were established by lipopolysaccharide (LPS) injection into the middle ear of mice via the tympanic membrane. Fisetin was administered to mice for ten days through intragastric administration immediate after LPS application. Hematoxylin and eosin (H&E) staining was performed and the pro-inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 and VEGF, were measured through enzyme-linked immunosorbent assay (ELISA) method and RT-qPCR analysis. Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway was detected by immunoblotting assays. Reactive oxygen species (ROS) generated levels were determined through assessment of anti-oxidants, and TXNIP/MAPKs signaling pathways were explored to reveal the possible molecular mechanism for acute otitis media progression and the function of fisetin. Fisetin reduced mucosal thickness caused by LPS. In fisetin-treated animals, pro-inflammatory cytokine release was downregulated accompanied with TLR4/NF-κB inactivation. ROS production was significantly decreased in comparison to the LPS-treated group. The TXNIP/MAPKs signaling pathway was inactivated for fisetin treatment in LPS-induced mice with acute otitis media. The above results indicated that fisetin improved acute otitis media through inflammation and ROS suppression via inactivating TLR4/NF-κB and TXNIP/MAPKs signaling pathways. PMID:29568876

Fisetin administration improves LPS-induced acute otitis media in mouse in vivo.

Science.gov (United States)

Li, Peng; Chen, Dan; Huang, Yang

2018-07-01

Acute otitis media is one of the most common infectious diseases worldwide in spite of the widespread vaccination. The present study was conducted to explore the effects of fisetin on mouse acute otitis media models. The animal models were established by lipopolysaccharide (LPS) injection into the middle ear of mice via the tympanic membrane. Fisetin was administered to mice for ten days through intragastric administration immediate after LPS application. Hematoxylin and eosin (H&E) staining was performed and the pro-inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 and VEGF, were measured through enzyme-linked immunosorbent assay (ELISA) method and RT-qPCR analysis. Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway was detected by immunoblotting assays. Reactive oxygen species (ROS) generated levels were determined through assessment of anti-oxidants, and TXNIP/MAPKs signaling pathways were explored to reveal the possible molecular mechanism for acute otitis media progression and the function of fisetin. Fisetin reduced mucosal thickness caused by LPS. In fisetin-treated animals, pro-inflammatory cytokine release was downregulated accompanied with TLR4/NF-κB inactivation. ROS production was significantly decreased in comparison to the LPS-treated group. The TXNIP/MAPKs signaling pathway was inactivated for fisetin treatment in LPS-induced mice with acute otitis media. The above results indicated that fisetin improved acute otitis media through inflammation and ROS suppression via inactivating TLR4/NF-κB and TXNIP/MAPKs signaling pathways.

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

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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

Modification of Salmonella Lipopolysaccharides Prevents the Outer Membrane Penetration of Novobiocin

Energy Technology Data Exchange (ETDEWEB)

Nobre, Thatyane M.; Martynowycz, Michael W.; Andreev, Konstantin; Kuzmenko, Ivan; Nikaido, Hiroshi; Gidalevitz, David

2015-12-01

Small hydrophilic antibiotics traverse the outer membrane of Gram-negative bacteria through porin channels. Large lipophilic agents traverse the outer membrane through its bilayer, containing a majority of lipopolysaccharides in its outer leaflet. Genes controlled by the two-component regulatory system PhoPQ modify lipopolysaccharides. We isolate lipopolysaccharides from isogenic mutants of Salmonella sp., one lacking the modification, the other fully modified. These lipopolysaccharides were reconstituted asmonolayers at the air-water interface, and their properties, aswell as their interaction with a large lipophilic drug, novobiocin, was studied. X-ray reflectivity showed that the drug penetrated the monolayer of the unmodified lipopolysaccharides reaching the hydrophobic region,butwas prevented fromthis penetration intothemodified lipopolysaccharides.Results correlatewith behavior of bacterial cells, which become resistant to antibiotics after PhoPQ-regulated modifications. Grazing incidence x-ray diffraction showed that novobiocin produced a striking increase in crystalline coherence length, and the size of the near-crystalline domains.

Activation of PPARα by Wy-14643 ameliorates systemic lipopolysaccharide-induced acute lung injury

International Nuclear Information System (INIS)

Yoo, Seong Ho; Abdelmegeed, Mohamed A.; Song, Byoung-Joon

2013-01-01

Highlights: •Activation of PPARα attenuated LPS-mediated acute lung injury. •Pretreatment with Wy-14643 decreased the levels of IFN-γ and IL-6 in ALI. •Nitrosative stress and lipid peroxidation were downregulated by PPARα activation. •PPARα agonists may be potential therapeutic targets for acute lung injury. -- Abstract: Acute lung injury (ALI) is a major cause of mortality and morbidity worldwide. The activation of peroxisome proliferator-activated receptor-α (PPARα) by its ligands, which include Wy-14643, has been implicated as a potential anti-inflammatory therapy. To address the beneficial efficacy of Wy-14643 for ALI along with systemic inflammation, the in vivo role of PPARα activation was investigated in a mouse model of lipopolysaccharide (LPS)-induced ALI. Using age-matched Ppara-null and wild-type mice, we demonstrate that the activation of PPARα by Wy-14643 attenuated LPS-mediated ALI. This was evidenced histologically by the significant alleviation of inflammatory manifestations and apoptosis observed in the lung tissues of wild-type mice, but not in the corresponding Ppara-null mice. This protective effect probably resulted from the inhibition of LPS-induced increases in pro-inflammatory cytokines and nitroxidative stress levels. These results suggest that the pharmacological activation of PPARα might have a therapeutic effect on LPS-induced ALI

Activation of PPARα by Wy-14643 ameliorates systemic lipopolysaccharide-induced acute lung injury

Energy Technology Data Exchange (ETDEWEB)

Yoo, Seong Ho, E-mail: yoosh@snu.ac.kr [Seoul National University Hospital, Biomedical Research Institute and Institute of Forensic Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Abdelmegeed, Mohamed A. [Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD (United States); Song, Byoung-Joon, E-mail: bj.song@nih.gov [Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD (United States)

2013-07-05

Highlights: •Activation of PPARα attenuated LPS-mediated acute lung injury. •Pretreatment with Wy-14643 decreased the levels of IFN-γ and IL-6 in ALI. •Nitrosative stress and lipid peroxidation were downregulated by PPARα activation. •PPARα agonists may be potential therapeutic targets for acute lung injury. -- Abstract: Acute lung injury (ALI) is a major cause of mortality and morbidity worldwide. The activation of peroxisome proliferator-activated receptor-α (PPARα) by its ligands, which include Wy-14643, has been implicated as a potential anti-inflammatory therapy. To address the beneficial efficacy of Wy-14643 for ALI along with systemic inflammation, the in vivo role of PPARα activation was investigated in a mouse model of lipopolysaccharide (LPS)-induced ALI. Using age-matched Ppara-null and wild-type mice, we demonstrate that the activation of PPARα by Wy-14643 attenuated LPS-mediated ALI. This was evidenced histologically by the significant alleviation of inflammatory manifestations and apoptosis observed in the lung tissues of wild-type mice, but not in the corresponding Ppara-null mice. This protective effect probably resulted from the inhibition of LPS-induced increases in pro-inflammatory cytokines and nitroxidative stress levels. These results suggest that the pharmacological activation of PPARα might have a therapeutic effect on LPS-induced ALI.

DNA methylcytosine dioxygenase ten-eleven translocation 2 enhances lipopolysaccharide-induced cytokine expression in human dental pulp cells by regulating MyD88 hydroxymethylation.

Science.gov (United States)

Wang, Xinxuan; Feng, Zhihui; Li, Qimeng; Yi, Baicheng; Xu, Qiong

2018-04-13

Dental pulp inflammation is a bacterially driven inflammation process characterized by the local accumulation of cytokines/chemokines that participate in destructive processes in the pulp. Multiple mechanisms are involved in dental pulp inflammation, including epigenetic events, such as DNA methylation/demethylation. Ten-eleven translocation 2 (TET2) is a recently discovered DNA methylcytosine dioxygenase that plays important roles in inflammatory disease. However, its role in the inflammatory response of dental pulp is unknown. We observed elevated mRNA and protein levels of TET2 after lipopolysaccharide (LPS) stimulation in human dental pulp cells (hDPCs). To identify the effects of TET2 on cytokine expression, TET2 was knocked down and cytokines were detected using a cytokine antibody array after LPS stimulation. The protein expression of GM-CSF, IL-6, IL-8 and RANTES decreased in the LPS-induced hDPCs following TET2 knockdown. The downregulated expression levels of IL-6 and IL-8 were further confirmed by real-time quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Additionally, the phosphorylation levels of IKK-α/β, p65 and IκBα of the NF-κB signaling pathway were decreased in the TET2-silenced group. Furthermore, the global 5-hydroxymethylcytosine (5hmC) level was significantly decreased and the genomic 5-methylcytosine (5mC) level was increased in the TET2-deficient hDPCs; TET2 depletion resulted in a decrease in the 5hmC level of the MyD88 promoter following LPS stimulation. These findings indicate that TET2 knockdown inhibits LPS-induced inflammatory response in hDPCs by downregulating MyD88 hydroxymethylation. Thus, TET2-dependent DNA demethylation might play an important role in dental pulp inflammation as an epigenetic regulator.

Evaluation of an Aqueous Extract from Horseradish Root (Armoracia rusticana Radix against Lipopolysaccharide-Induced Cellular Inflammation Reaction

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Corinna Herz

2017-01-01

Full Text Available Horseradish (Armoracia rusticana is a perennial crop and its root is used in condiments. Traditionally, horseradish root is used to treat bacterial infections of the respiratory tract and urinary bladder. The antiphlogistic activity, determined in activated primary human peripheral blood mononuclear cells (PBMC, was evaluated for an aqueous extract and its subfractions, separated by HPLC. Compound analysis was done by UHPLC-QToF/MS and GC-MS. The aqueous extract concentration-dependently inhibited the anti-inflammatory response to lipopolysaccharide (LPS in terms of TNF-α release at ≥37 μg/mL. Further, the cyclooxygenase as well as lipoxygenase pathway was blocked by the extract as demonstrated by inhibition of COX-2 protein expression and PGE2 synthesis at ≥4 μg/mL and leukotriene LTB4 release. Mechanistic studies revealed that inhibition of ERK1/2 and c-Jun activation preceded COX-2 suppression upon plant extract treatment in the presence of LPS. Chemical analysis identified target compounds with a medium polarity as relevant for the observed bioactivity. Importantly, allyl isothiocyanate, which is quite well known for its anti-inflammatory capacity and as the principal pungent constituent in horseradish roots, was not relevant for the observations. The results suggest that horseradish root exerts an antiphlogistic activity in human immune cells by regulation of the COX and LOX pathway via MAPK signalling.

Evaluation of an Aqueous Extract from Horseradish Root (Armoracia rusticana Radix) against Lipopolysaccharide-Induced Cellular Inflammation Reaction.

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Herz, Corinna; Tran, Hoai Thi Thu; Márton, Melinda-Rita; Maul, Ronald; Baldermann, Susanne; Schreiner, Monika; Lamy, Evelyn

2017-01-01

Horseradish ( Armoracia rusticana ) is a perennial crop and its root is used in condiments. Traditionally, horseradish root is used to treat bacterial infections of the respiratory tract and urinary bladder. The antiphlogistic activity, determined in activated primary human peripheral blood mononuclear cells (PBMC), was evaluated for an aqueous extract and its subfractions, separated by HPLC. Compound analysis was done by UHPLC-QToF/MS and GC-MS. The aqueous extract concentration-dependently inhibited the anti-inflammatory response to lipopolysaccharide (LPS) in terms of TNF- α release at ≥37  μ g/mL. Further, the cyclooxygenase as well as lipoxygenase pathway was blocked by the extract as demonstrated by inhibition of COX-2 protein expression and PGE 2 synthesis at ≥4  μ g/mL and leukotriene LTB4 release. Mechanistic studies revealed that inhibition of ERK1/2 and c-Jun activation preceded COX-2 suppression upon plant extract treatment in the presence of LPS. Chemical analysis identified target compounds with a medium polarity as relevant for the observed bioactivity. Importantly, allyl isothiocyanate, which is quite well known for its anti-inflammatory capacity and as the principal pungent constituent in horseradish roots, was not relevant for the observations. The results suggest that horseradish root exerts an antiphlogistic activity in human immune cells by regulation of the COX and LOX pathway via MAPK signalling.

Neocryptotanshinone inhibits lipopolysaccharide-induced inflammation in RAW264.7 macrophages by suppression of NF-κB and iNOS signaling pathways

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Chuanhong Wu

2015-07-01

Full Text Available Neocryptotanshinone (NCTS is a natural product isolated from traditional Chinese herb Salvia miltiorrhiza Bunge. In this study, we investigated its anti-inflammatory effects in lipopolysaccharide (LPS-stimulated mouse macrophage (RAW264.7 cells. MTT results showed that NCTS partly reversed LPS-induced cytotoxicity. Real-time PCR results showed that NCTS suppressed LPS-induced mRNA expression of inflammatory cytokines, including tumor necrosis factor α (TNFα, interleukin-6 (IL-6 and interleukin-1β (IL-1β. Moreover, NCTS could decrease LPS-induced nitric oxide (NO production. Western blotting results showed that NCTS could down-regulate LPS-induced expression of inducible nitric oxide synthase (iNOS, p-IκBα, p-IKKβ and p-NF-κB p65 without affecting cyclooxygenase-2 (COX-2. In addition, NCTS inhibited LPS-induced p-NF-κB p65 nuclear translocation. In conclusion, these data demonstrated that NCTS showed anti-inflammatory effect by suppression of NF-κB and iNOS signaling pathways.

Nitric oxide-releasing flurbiprofen reduces formation of proinflammatory hydrogen sulfide in lipopolysaccharide-treated rat

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Anuar, Farhana; Whiteman, Matthew; Siau, Jia Ling; Kwong, Shing Erl; Bhatia, Madhav; Moore, Philip K

2006-01-01

The biosynthesis of both nitric oxide (NO) and hydrogen sulfide (H2S) is increased in lipopolysaccharide (LPS)-injected mice and rats but their interaction in these models is not known. In this study we examined the effect of the NO donor, nitroflurbiprofen (and the parent molecule flurbiprofen) on NO and H2S metabolism in tissues from LPS-pretreated rats. Administration of LPS (10 mg kg−1, i.p.; 6 h) resulted in an increase (PFlurbiprofen (21 mg kg−1, i.p.) was without effect. These results show for the first time that nitroflurbiprofen downregulates the biosynthesis of proinflammatory H2S and suggest that such an effect may contribute to the augmented anti-inflammatory activity of this compound. These data also highlight the existence of ‘crosstalk' between NO and H2S in this model of endotoxic shock. PMID:16491094

Increase in hypothalamic AMPK phosphorylation induced by prolonged exposure to LPS involves ghrelin and CB1R signaling.

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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.

Aggregation of thrombin-derived C-terminal fragments as a previously undisclosed host defense mechanism

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Petrlova, Jitka; Hansen, Finja C; van der Plas, Mariena J A

2017-01-01

bind to and form amorphous amyloid-like aggregates with both bacterial lipopolysaccharide (LPS) and gram-negative bacteria. In silico molecular modeling using atomic resolution and coarse-grained simulations corroborates our experimental observations, altogether indicating increased aggregation through...

Structural and functional studies of conserved nucleotide-binding protein LptB in lipopolysaccharide transport

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Wang, Zhongshan [Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, NR4 7TJ (United Kingdom); College of Life Sciences, Sichuan University, Chengdu 610065 (China); Biomedical Sciences Research Complex, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST (United Kingdom); Xiang, Quanju [College of Life Sciences, Sichuan University, Chengdu 610065 (China); Biomedical Sciences Research Complex, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST (United Kingdom); Department of Microbiology, College of Resource and Environment Science, Sichuan Agriculture University, Yaan 625000 (China); Zhu, Xiaofeng [College of Life Sciences, Sichuan University, Chengdu 610065 (China); Dong, Haohao [Biomedical Sciences Research Complex, School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST (United Kingdom); He, Chuan [School of Electronics and Information, Wuhan Technical College of Communications, No. 6 Huangjiahu West Road, Hongshan District, Wuhan, Hubei 430065 (China); Wang, Haiyan; Zhang, Yizheng [College of Life Sciences, Sichuan University, Chengdu 610065 (China); Wang, Wenjian, E-mail: Wenjian166@gmail.com [Laboratory of Department of Surgery, The First Affiliated Hospital, Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong 510080 (China); Dong, Changjiang, E-mail: C.Dong@uea.ac.uk [Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, NR4 7TJ (United Kingdom)

2014-09-26

Highlights: • Determination of the structure of the wild-type LptB in complex with ATP and Mg{sup 2+}. • Demonstrated that ATP binding residues are essential for LptB’s ATPase activity and LPS transport. • Dimerization is required for the LptB’s function and LPS transport. • Revealed relationship between activity of the LptB and the vitality of E. coli cells. - Abstract: Lipopolysaccharide (LPS) is the main component of the outer membrane of Gram-negative bacteria, which plays an essential role in protecting the bacteria from harsh conditions and antibiotics. LPS molecules are transported from the inner membrane to the outer membrane by seven LPS transport proteins. LptB is vital in hydrolyzing ATP to provide energy for LPS transport, however this mechanism is not very clear. Here we report wild-type LptB crystal structure in complex with ATP and Mg{sup 2+}, which reveals that its structure is conserved with other nucleotide-binding proteins (NBD). Structural, functional and electron microscopic studies demonstrated that the ATP binding residues, including K42 and T43, are crucial for LptB’s ATPase activity, LPS transport and the vitality of Escherichia coli cells with the exceptions of H195A and Q85A; the H195A mutation does not lower its ATPase activity but impairs LPS transport, and Q85A does not alter ATPase activity but causes cell death. Our data also suggest that two protomers of LptB have to work together for ATP hydrolysis and LPS transport. These results have significant impacts in understanding the LPS transport mechanism and developing new antibiotics.