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Sample records for agonist lipopolysaccharide lps

  1. Lipopolysaccharide (LPS) stimulation of fungal secondary metabolism

    PubMed Central

    Khalil, Zeinab G.; Kalansuriya, Pabasara; Capon, Robert J.

    2014-01-01

    We report on a preliminary investigation of the use the Gram-negative bacterial cell wall constituent lipopolysaccharide (LPS) as a natural chemical cue to stimulate and alter the expression of fungal secondary metabolism. Integrated high-throughput micro-cultivation and micro-analysis methods determined that 6 of 40 (15%) of fungi tested responded to an optimal exposure to LPS (0.6 ng/mL) by activating, enhancing or accelerating secondary metabolite production. To explore the possible mechanisms behind this effect, we employed light and fluorescent microscopy in conjunction with a nitric oxide (NO)-sensitive fluorescent dye and an NO scavenger to provide evidence that LPS stimulation of fungal secondary metabolism coincided with LPS activation of NO. Several case studies demonstrated that LPS stimulation can be scaled from single microplate well (1.5 mL) to preparative (>400 mL) scale cultures. For example, LPS treatment of Penicillium sp. (ACM-4616) enhanced pseurotin A and activated pseurotin A1 and pseurotin A2 biosynthesis, whereas LPS treatment of Aspergillus sp. (CMB-M81F) substantially accelerated and enhanced the biosynthesis of shornephine A and a series of biosynthetically related ardeemins and activated production of neoasterriquinone. As an indication of broader potential, we provide evidence that cultures of Penicillium sp. (CMB-TF0411), Aspergillus niger (ACM-4993F), Rhizopus oryzae (ACM-165F) and Thanatephorus cucumeris (ACM-194F) were responsive to LPS stimulation, the latter two examples being particular noteworthy as neither are known to produce secondary metabolites. Our results encourage the view that LPS stimulation can be used as a valuable tool to expand the molecular discovery potential of fungal strains that either have been exhaustively studied by or are unresponsive to traditional culture methodology. PMID:25379339

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

    PubMed

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

    2003-02-01

    Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with chylomicrons and enhance the amount of LPS binding to chylomicrons in a dose-dependent fashion. In addition, LBP accelerated LPS binding to chylomicrons. This LBP-induced interaction of LPS with chylomicrons prevented endotoxin toxicity, as demonstrated by reduced cytokine secretion by PBMC. When postprandial circulating concentrations of chylomicrons were compared with circulating levels of low density lipoprotein, very low density lipoprotein, and high density lipoprotein, chylomicrons exceeded the other lipoproteins in LPS-inactivating capacity. Furthermore, highly purified lipoteichoic acid, an immunostimulatory component of Gram-positive bacteria, was detoxified by incubation with LBP and chylomicrons. In conclusion, our results indicate that LBP associates with chylomicrons and enables chylomicrons to rapidly bind bacterial toxin, thereby preventing cell activation. Besides a role in the detoxification of bacterial toxin present in the circulation, we believe that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxin. PMID:12538700

  3. Locally administered T cells from mice immunized with lipopolysaccharide (LPS) accelerate LPS-induced bone resorption.

    PubMed

    Ozaki, Yukio; Ukai, Takashi; Yamaguchi, Masayuki; Yokoyama, Miho; Haro, Esperanza R Ayón; Yoshimoto, Mayumi; Kaneko, Takashi; Yoshinaga, Miho; Nakamura, Hirotaka; Shiraishi, Chiaki; Hara, Yoshitaka

    2009-06-01

    T cells play important roles in bone destruction and osteoclastogenesis and are found in chronic destructive bone lesions. Lipopolysaccharide (LPS) is one of several pathological factors involved in inflammatory bone destruction. We previously described the importance of T cells in the inflammatory bone resorption that occurs after repeated LPS administration. However, whether local or systemic T cells are important for inflammatory bone resorption and whether immunization of host animals influences bone resorption remain unclear. The present study examines the effects of local extant T cells from LPS-immunized mice on LPS-induced bone resorption. T cells from LPS-immunized or non-immunized mice were injected together with LPS into the gingival tissues of mice with severe combined immunodeficiency disease that lack both T and B cells. We histomorphometrically evaluated bone resorption at sites of T cell injections and examined the influence of T cells from LPS-immunized mice on osteoclastogenesis in vitro. We found that locally administered T cells from LPS-immunized but not non-immunized mice accelerated LPS-induced bone resorption in vivo. Moreover, T cells from LPS-immunized mice increased osteoclastogenesis in vitro induced by receptor activator of NF-kappa B ligand and LPS and anti-tumor necrosis factor (TNF)-alpha antibody inhibited this increase. These results demonstrated that local extant T cells accelerate inflammatory bone resorption. Furthermore, T cells from LPS-immunized mice appear to elevate LPS-induced bone resorption using TNF-alpha. PMID:19437611

  4. Geranylgeranylacetone Ameliorates Inflammatory Response to Lipopolysaccharide (LPS) in Murine Macrophages: Inhibition of LPS Binding to The Cell Surface

    PubMed Central

    Mochida, Shinsuke; Matsura, Tatsuya; Yamashita, Atsushi; Horie, Shunsuke; Ohata, Shuzo; Kusumoto, Chiaki; Nishida, Tadashi; Minami, Yukari; Inagaki, Yoshimi; Ishibe, Yuichi; Nakada, Junya; Ohta, Yoshiji; Yamada, Kazuo

    2007-01-01

    We investigated whether pretreatment with geranylgeranylacetone (GGA), a potent heat shock protein (HSP) inducer, could inhibit proinflammatory cytokine liberation and nitric oxide (NO) production in lipopolysaccharide (LPS)-treated murine macrophages. The levels of NO and tumor necrosis factor-α (TNF-α) released from murine macrophage RAW 264 cells were increased dose- and time-dependently following treatment with LPS (1 µg/ml). GGA (80 µM) treatment 2 h before LPS addition significantly suppressed TNF-α and NO productions at 12 h and 24 h after LPS, respectively, indicating that GGA inhibits activation of macrophages. However, replacement by fresh culture medium before LPS treatment abolished the inhibitory effect of GGA on NO production in LPS-treated cells. Furthermore, GGA inhibited both HSP70 and inducible NO synthase expressions induced by LPS treatment despite an HSP inducer. When it was examined whether GGA interacts with LPS and/or affects expression of Toll-like receptor 4 (TLR4) and CD14 on the cell surface, GGA inhibited the binding of LPS to the cell surface, while GGA did not affect TLR4 and CD14 expressions. These results indicate that GGA suppresses the binding of LPS to the cell surface of macrophages, resulting in inhibiting signal transduction downstream of TLR4. PMID:18193105

  5. The CRTH2 agonist Pyl A prevents lipopolysaccharide-induced fetal death but induces preterm labour

    PubMed Central

    Sykes, Lynne; Herbert, Bronwen R; MacIntyre, David A; Hunte, Emma; Ponnampalam, Sathana; Johnson, Mark R; Teoh, Tiong G; Bennett, Phillip R

    2013-01-01

    We have previously demonstrated that the anti-inflammatory prostaglandin 15-deoxy-Δ 12,14-prostaglandin J2 (15dPGJ2) delays inflammation-induced preterm labour in the mouse and improves pup survival through the inhibition of nuclear factor-κB (NF-κB) by a mechanism yet to be elucidated. 15dPGJ2 is an agonist of the second prostaglandin D2 receptor, chemoattractant receptor homologous to the T helper 2 cell (CRTH2). In human T helper cells CRTH2 agonists induce the production of the anti-inflammatory interleukins IL-10 and IL-4. We hypothesized that CRTH2 is involved in the protective effect of 15dPGJ2 in inflammation-induced preterm labour in the murine model. We therefore studied the effects of a specific small molecule CRTH2 agonist on preterm labour and pup survival. An intrauterine injection of lipopolysaccharide (LPS) was administered to CD1 mice at embryonic day 16, ± CRTH2 agonist/vehicle controls. Mice were killed at 4.5 hr to assess fetal wellbeing and to harvest myometrium and pup brain for analysis of NF-κB, and T helper type 1/2 interleukins. To examine the effects of the CRTH2 agonist on LPS-induced preterm labour, mice were allowed to labour spontaneously. Direct effects of the CRTH2 agonist on uterine contractility were examined ex vivo on contracting myometrial strips. The CRTH2 agonist increased fetal survival from 20 to 100% in LPS-treated mice, and inhibited circular muscle contractility ex vivo. However, it augmented LPS-induced labour and significantly increased myometrial NF-κB, IL-1β, KC-GRO, interferon-γ and tumour necrosis factor-α. This suggests that the action of 15dPGJ2 is not via CRTH2 and therefore small molecule CRTH2 agonists are not likely to be beneficial for the prevention of inflammation-induced preterm labour. PMID:23374103

  6. Prenatal transportation alters the metabolic response of Brahman bull calves exposed to a lipopolysaccharide (LPS) challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine if prenatal transportation influences the metabolic response to a postnatal lipopolysaccharide (LPS) challenge. Pregnant Brahman cows (n=96) matched by age and parity were separated into transported (TRANS; n=48; transported for 2 hours on gestational day 60, 80,...

  7. Immunoelectron microscopic localization of chlamydial lipopolysaccharide (LPS) in McCoy cells inoculated with Chlamydia trachomatis.

    PubMed

    Hearn, S A; McNabb, G L

    1991-08-01

    Interactions between Chlamydia trachomatis, host cells, and the immune system are believed to involve lipopolysaccharide (LPS). We used immunogold techniques to study the distribution of chlamydial LPS in cultured cells infected with C. trachomatis LGV-L1. McCoy cells inoculated with C. trachomatis were cultured and then fixed and embedded in situ with acrylic resins. Sections were immunolabeled with a protein A-gold method using antisera to the genus-specific, periodate-sensitive epitope on chlamydial LPS. Pre-embedding immunogold labeling on permeabilized cells was also done. By post-embedding methods, labeling for LPS was equally abundant over the outer membranes of elementary (EB) and reticulate bodies (RB). By post-embedding labeling, the sub-surface side of the EB outer membrane was more heavily labeled than the surface side. By pre-embedding labeling, LPS was found to be less abundant on the surface of EBs than RBs. Labeling for LPS was found over apparent lysosomes in McCoy cells and over electron-dense blebs on or near the surface of the plasma membranes of McCoy cells. These results indicate that the concentration of LPS in chlamydial membranes is constant during development but that with development its location changes from being mostly cell-surface to sub-surface. These results show that the post-embedding immunogold technique can be a useful approach for the cell culture-based study of chlamydial LPS. PMID:1649854

  8. Oenothein B Suppresses Lipopolysaccharide (LPS)-Induced Inflammation in the Mouse Brain

    PubMed Central

    Okuyama, Satoshi; Makihata, Nahomi; Yoshimura, Morio; Amakura, Yoshiaki; Yoshida, Takashi; Nakajima, Mitsunari; Furukawa, Yoshiko

    2013-01-01

    Oenothein B has been recently evaluated for its ability to affect inflammatory responses in peripheral tissues. In this study, we examined its effect on the damage to the central nervous system due to systemic inflammation. For this purpose, ICR mice were injected with an intraperitoneal (i.p.) dose of lipopolysaccharide (LPS; 1 mg/kg mouse). When oenothein B was administered per os (p.o.), it suppressed (1) LPS-induced abnormal behavior in open field; (2) LPS-induced microglial activation in the hippocampus and striatum; and (3) LPS-induced cyclooxygenase (COX)-2 production in the hippocampus and striatum of these mice. These results suggest that oenothein B had the ability to reduce neuroinflammation in the brain during systemic inflammation. PMID:23652834

  9. Oenothein B suppresses lipopolysaccharide (LPS)-induced inflammation in the mouse brain.

    PubMed

    Okuyama, Satoshi; Makihata, Nahomi; Yoshimura, Morio; Amakura, Yoshiaki; Yoshida, Takashi; Nakajima, Mitsunari; Furukawa, Yoshiko

    2013-01-01

    Oenothein B has been recently evaluated for its ability to affect inflammatory responses in peripheral tissues. In this study, we examined its effect on the damage to the central nervous system due to systemic inflammation. For this purpose, ICR mice were injected with an intraperitoneal (i.p.) dose of lipopolysaccharide (LPS; 1 mg/kg mouse). When oenothein B was administered per os (p.o.), it suppressed (1) LPS-induced abnormal behavior in open field; (2) LPS-induced microglial activation in the hippocampus and striatum; and (3) LPS-induced cyclooxygenase (COX)-2 production in the hippocampus and striatum of these mice. These results suggest that oenothein B had the ability to reduce neuroinflammation in the brain during systemic inflammation. PMID:23652834

  10. Diphosphoryl lipid A from Rhodobacter sphaeroides inhibits complexes that form in vitro between lipopolysaccharide (LPS)-binding protein, soluble CD14, and spectrally pure LPS.

    PubMed Central

    Jarvis, B W; Lichenstein, H; Qureshi, N

    1997-01-01

    An early event in septic shock is the activation of macrophages by a complex consisting of lipopolysaccharide (LPS), LPS-binding protein (LBP), and the cell surface antigen CD14. The complexes that form between [3H]ReLPS (ReLPS is deep-rough-chemotype hexacyl LPS from E. coli D31m4), soluble CD14 (sCD14), and LBP were analyzed by two independent methods, native (nondenaturing) gel electrophoresis and size-exclusion high-performance liquid chromatography (HPLC). This is the first reported use of HPLC to purify and study LPS-protein complexes. The binding of [3H]ReLPS to LBP and sCD14 was inhibited by preincubation with diphosphoryl lipid A from Rhodobacter sphaeroides (RsDPLA), a potent LPS antagonist. In addition, [3H]ReLPS bound to LBP and to a truncated form of sCD14 [sCD14(1-152)] that contained the LPS binding domain. Binding to both proteins was blocked by RsDPLA. Thus, RsDPLA competes in a 1:1 ratio for the same or nearby binding sites on ReLPS complexes. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of aggregated ReLPS eluting from the HPLC indicated that only LBP, not sCD14, was bound to the aggregated ReLPS. This finding supports the binary model of LPS complex formation with LBP and sCD14. PMID:9234747

  11. A lipopolysaccharide (LPS)-resistant mutant isolated from a macrophagelike cell line, J774.1, exhibits an altered activated-macrophage phenotype in response to LPS.

    PubMed

    Amano, F; Akamatsu, Y

    1991-06-01

    A bacterial lipopolysaccharide (LPS)-resistant mutant was isolated from murine macrophagelike cell line J774.1. The mutant showed selective resistance to LPS and lipid A and was almost 10(5)- to 10(6)-fold more resistant than the parent; it grew even in the presence of 1 mg of Escherichia coli O55:B5 LPS per liter, whereas the parent did not grow with less than 10 ng of LPS per milliliter. We next examined the mutant for activation of various functions of macrophages on LPS treatment. This LPS-resistant mutant secreted interleukin-1 and tumor necrosis factor almost as effectively as the parent did. The mutant cells also changed transiently from a round to a spread form; however, they became round again afterwards. The mutant cells secreted less arachidonic acid in response to LPS. These results also suggest that this LPS-resistant mutant responds to LPS and shows activation of some macrophage functions. However, this mutant did not exhibit elevation of O2- generation or H2O2 generation after LPS treatment. Also, treatment of the mutant cells with murine recombinant gamma interferon was partly able to correct the defect in O(2-)-generating activity in response to LPS, suggesting that this defect is probably due to some of the LPS signal pathways. This implies that there is some correlation between O2- metabolism in LPS-activated macrophages and decreases in cell growth and viability. PMID:1645329

  12. Lipopolysaccharide (LPS) disrupts particle transport, cilia function and sperm motility in an ex vivo oviduct model

    PubMed Central

    O’Doherty, A. M.; Di Fenza, M.; Kölle, S.

    2016-01-01

    The oviduct functions in the transportation of gametes to the site of fertilization (the ampulla) and is the site of early embryonic development. Alterations of this early developmental environment, such as the presence of sexually transmitted pathogens, may affect oviduct function leading to reduced fertilization rates and contribute to compromised embryonic development. In this study, sperm interactions, particle transport speed (PTS) and cilia beat frequency (CBF) in the ampulla following exposure to lipopolysaccharide (LPS), a constituent of the sexually transmitted pathogens Chlamydia trachomatis and Chlamydia abortus, was investigated. Three complementary experiments were performed to analyse; (1) bound sperm motility and cilia function (2) transport velocity in the oviduct and (3) the expression of genes related to immune function and inflammatory response (CASP3, CD14, MYD88, TLR4 and TRAF6). The motility of bound sperm was significantly lower in ampullae that were exposed to LPS. CBF and PTS significantly increased after treatment with LPS for 2 hours. Finally, gene expression analysis revealed that CASP3 and CD14 were significantly upregulated and TLR4 trended towards increased expression following treatment with LPS. These findings provide an insight on the impact of LPS on the oviduct sperm interaction, and have implications for both male and female fertility. PMID:27079521

  13. Gelam Honey Has a Protective Effect against Lipopolysaccharide (LPS)-Induced Organ Failure

    PubMed Central

    Kassim, Mustafa; Mansor, Marzida; Al-Abd, Nazeh; Yusoff, Kamaruddin Mohd

    2012-01-01

    Gelam honey exerts anti-inflammatory and antioxidant activities and is thought to have potent effects in reducing infections and healing wounds. The aim of this study was to investigate the effects of intravenously-injected Gelam honey in protecting organs from lethal doses of lipopolysaccharide (LPS). Six groups of rabbits (N = 6) were used in this study. Two groups acted as controls and received only saline and no LPS injections. For the test groups, 1 mL honey (500 mg/kg in saline) was intravenously injected into two groups (treated), while saline (1 mL) was injected into the other two groups (untreated); after 1 h, all four test groups were intravenously-injected with LPS (0.5 mg/kg). Eight hours after the LPS injection, blood and organs were collected from three groups (one from each treatment stream) and blood parameters were measured and biochemical tests, histopathology, and myeloperoxidase assessment were performed. For survival rate tests, rabbits from the remaining three groups were monitored over a 2-week period. Treatment with honey showed protective effects on organs through the improvement of organ blood parameters, reduced infiltration of neutrophils, and decreased myeloperoxidase activity. Honey-treated rabbits also showed reduced mortality after LPS injection compared with untreated rabbits. Honey may have a therapeutic effect in protecting organs during inflammatory diseases. PMID:22754370

  14. Upregulation of prolylcarboxypeptidase (PRCP) in lipopolysaccharide (LPS) treated endothelium promotes inflammation

    PubMed Central

    Ngo, My-Linh; Mahdi, Fakhri; Kolte, Dhaval; Shariat-Madar, Zia

    2009-01-01

    Background Prolylcarboxypeptidase (Prcp) gene, along with altered PRCP and kallikrein levels, have been implicated in inflammation pathogenesis. PRCP regulates angiotensin 1–7 (Ang 1–7) – and bradykinin (BK) – stimulated nitric oxide production in endothelial cells. The mechanism through which kallikrein expression is altered during infection is not fully understood. Investigations were performed to determine the association between PRCP and kallikrein levels as a function of the upregulation of PRCP expression and the link between PRCP and inflammation risk in lipopolysaccharide (LPS)-induced endothelium activation. Methods The Prcp transcript expression in LPS-induced human umbilical vein endothelial cells (HUVEC) activation was determined by RT-PCR for mRNA. PRCP-dependent kallikrein pathway was determined either by Enzyme Linked ImmunoSorbent Assay (ELISA) or by biochemical assay. Results We report that PRCP is critical to the maintenance of the endothelial cells, and its upregulation contributes to the risk of developing inflammation. Significant elevation in kallikrein was seen on LPS-treated HUVECs. The conversion of PK to kallikrein was blocked by the inhibitor of PRCP, suggesting that PRCP might be a risk factor for inflammation. Conclusion The increased PRCP lead to a sustained production of bradykinin in endothelium following LPS treatment. This amplification may be an additional mechanism whereby PRCP promotes a sustained inflammatory response. A better appreciation of the role of PRCP in endothelium may contribute to a better understanding of inflammatory vascular disorders and to the development of a novel treatment. PMID:19171072

  15. Picrasma quassiodes (D. Don) Benn. attenuates lipopolysaccharide (LPS)-induced acute lung injury.

    PubMed

    Lee, Jae-Won; Park, Ji-Won; Shin, Na-Rae; Park, So-Yeon; Kwon, Ok-Kyoung; Park, Hyun Ah; Lim, Yourim; Ryu, Hyung Won; Yuk, Heung Joo; Kim, Jung Hee; Oh, Sei-Ryang; Ahn, Kyung-Seop

    2016-09-01

    Picrasma quassiodes (D.Don) Benn. (PQ) is a medicinal herb belonging to the family Simaroubaceae and is used as a traditional herbal remedy for various diseases. In this study, we evaluated the effects of PQ on airway inflammation using a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI) and LPS-stimulated raw 264.7 cells. ALI was induced in C57BL/6 mice by the intranasal administration of LPS, and PQ was administered orally 3 days prior to exposure to LPS. Treatment with PQ significantly attenuated the infiltration of inflammatory cells in the bronchoalveolar lavage fluid (BALF). PQ also decreased the production of reactive oxygen species (ROS) and pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 in BALF. In addition, PQ inhibited airway inflammation by reducing the expression of inducible nitric oxide synthase (iNOS) and by increasing the expression of heme oxygenase-1 (HO-1) in the lungs. Furthermore, we demonstrated that PQ blocked the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) in the lungs of mice with LPS-induced ALI. In the LPS-stimulated RAW 264.7 cells, PQ inhibited the release of pro-inflammatory cytokines and increased the mRNA expression of monocyte chemoattractant protein-1 (MCP-1). Treatment with PQ decreased the translocation of nuclear factor (NF)-κB to the nucleus, and increased the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and the expression of HO-1. PQ also inhibited the activation of p38 in the LPS-stimulated RAW 264.7 cells. Taken together, our findings demonstrate that PQ exerts anti-inflammatory effects against LPS-induced ALI, and that these effects are associated with the modulation of iNOS, HO-1, NF-κB and MAPK signaling. Therefore, we suggest that PQ has therapeutic potential for use in the treatment of ALI. PMID:27431288

  16. Analysis of Ionomic Profiles of Canine Hairs Exposed to Lipopolysaccharide (LPS)-Induced Stress.

    PubMed

    So, Kyoung-Min; Lee, Yoonseok; Bok, Jin Duck; Kim, Eun Bae; Chung, Myung Il

    2016-08-01

    The purpose of this study was to provide a new insight on the response of canines to stress exposure; the ionomic profiles of canine hair (2.8 ± 0.3 years, 15.17 ± 2.1 kg) (n = 10) was determined before and after lipopolysaccharide (LPS) injections. LPS was intramuscularly injected to induce inflammatory stress responses which were confirmed by observing increases in the level of serum cortisol, aldosterone, and inflammatory cytokines such as IL-6, IL-1β, and TNF-α. The hair contents of 17 elements were obtained by applying analytical procedures using the inductively coupled plasma mass spectrometry (ICP-MS). The following elements: sodium(Na) and potassium(K) among macro-elements, iron(Fe) and manganese(Mn) among micro-elements, and aluminum(Al), nickel(Ni), and lead(Pb) for toxic elements, showed significant increased levels with the immunological stress. The degree of increase in toxic elements was remarkable with the stress exposure. A forty-five-fold increase seen in Al accumulation with the stress exposure was noteworthy. Although mercury(Hg) and cadmium(Cd) showed decreased levels with the stress exposure, the degree was negligible compared to the level of increase. Correlation pattern between the elements was changed with the immunological stress. Toxic elements became more correlated with macro- or micro-elements than with toxic elements themselves after the stress exposure. Principal component analysis (PCA) showed that LPS challenge shifted the overall hair mineral profiles to a consistent direction changing Al and K up, even in animals with different hair mineral profiles before LPS treatment. In conclusion, the multivariate data processing and study of element distribution patterns provided new information about the ionomic response of the canine hairs to immunological stress, i.e., the ionomic profiles of canine hairs is strongly affected by the stress induced by LPS injections. PMID:26758868

  17. Lipopolysaccharide (LPS) inhibits steroid production in theca cells of bovine follicles in vitro: distinct effect of LPS on theca cell function in pre- and post-selection follicles.

    PubMed

    Magata, Fumie; Horiuchi, Maya; Miyamoto, Akio; Shimizu, Takashi

    2014-01-01

    In postpartum dairy cows, lipopolysaccharide (LPS) derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation and leads to ovarian dysfunction. The aim of this study was to determine the effect of LPS on steroid production in bovine theca cells at different stages of follicular development. Theca cells isolated from pre- and post-selection follicles (PRFs, <8.5 mm in diameter, and POFs, >8.5 mm in diameter, respectively) of bovine ovaries were exposed to LPS under luteinizing hormone (LH) conditions, estradiol (E2) conditions or both conditions in vitro. Bovine theca cells expressed the LPS receptor gene complex: Toll-like receptor 4 (TLR4), CD14 and MD2. LPS suppressed progesterone (P4) and androstenedione (A4) production with downregulation of steroidogenic enzyme transcripts when theca cells were stimulated with LH. By contrast, LPS did not affect P4 or A4 production when theca cells were stimulated with E2. P4 and A4 production in theca cells from PRFs was suppressed by LPS as early as at 48 h of culture, whereas the effect of LPS on theca cells from POFs was observed at 96 h of culture. The results demonstrate that LPS inhibits steroid production in theca cells under LH conditions. Moreover, theca cells from POFs showed a slower response to LPS compared with that of theca cells from PRFs, which might imply a distinct effect of LPS on follicles at different developmental stages. These findings suggest a possible mechanism of ovarian dysfunction and subsequent infertility in cows with endometritis. PMID:24769841

  18. Lipopolysaccharide (LPS) Inhibits Steroid Production in Theca Cells of Bovine Follicles In Vitro: Distinct Effect of LPS on Theca Cell Function in Pre- and Post-selection Follicles

    PubMed Central

    MAGATA, Fumie; HORIUCHI, Maya; MIYAMOTO, Akio; SHIMIZU, Takashi

    2014-01-01

    In postpartum dairy cows, lipopolysaccharide (LPS) derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation and leads to ovarian dysfunction. The aim of this study was to determine the effect of LPS on steroid production in bovine theca cells at different stages of follicular development. Theca cells isolated from pre- and post-selection follicles (PRFs, <8.5 mm in diameter, and POFs, >8.5 mm in diameter, respectively) of bovine ovaries were exposed to LPS under luteinizing hormone (LH) conditions, estradiol (E2) conditions or both conditions in vitro. Bovine theca cells expressed the LPS receptor gene complex: Toll-like receptor 4 (TLR4), CD14 and MD2. LPS suppressed progesterone (P4) and androstenedione (A4) production with downregulation of steroidogenic enzyme transcripts when theca cells were stimulated with LH. By contrast, LPS did not affect P4 or A4 production when theca cells were stimulated with E2. P4 and A4 production in theca cells from PRFs was suppressed by LPS as early as at 48 h of culture, whereas the effect of LPS on theca cells from POFs was observed at 96 h of culture. The results demonstrate that LPS inhibits steroid production in theca cells under LH conditions. Moreover, theca cells from POFs showed a slower response to LPS compared with that of theca cells from PRFs, which might imply a distinct effect of LPS on follicles at different developmental stages. These findings suggest a possible mechanism of ovarian dysfunction and subsequent infertility in cows with endometritis. PMID:24769841

  19. Prenatal transportation alters the acute phase response (APR) of bull calves exposed to a lipopolysaccharide (LPS) challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine if prenatal transportation influences the acute phase response (APR) to a postnatal Lipopolysaccharide (LPS) challenge. Pregnant Brahman cows (n=96) matched by age and parity were separated into transported (TRANS; n=48; transported for 2 hours on gestational day...

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

    PubMed

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

    2013-08-01

    The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium was evaluated in sheep experimentally infected with Fasciola hepatica. Animals were divided into four groups: two treated with the LPS (T1/T2) and two controls (C1/C2). T1/C1 were slaughtered at 30 days postinfection (dpi) and T2/C2 at 85 dpi. Body weight and body condition were found higher in T1 and T2 than in controls, although differences were not significant. Treated sheep showed lower cumulative fecal egg count than controls (p < 0.01). Levels of red blood cells (RBC), white blood cells, hemoglobin, and hematocrit (HCT) were higher in T1 and T2. Significant differences (p < 0.05) in RBC and HCT were found between groups at 84 dpi. More severe macrocytic and hypochromic anemia was observed in C1 and C2 than in treated groups. Total protein and albumin values were higher in T1 and T2 (p < 0.01) until 29 dpi. At the end of the trial, no significant differences were observed in hepatic enzymes, although gamma-glutamyl transferase and aspartate aminotransferase values were higher in C2, and alanine aminotransferase was higher in T2. At necropsy, the mean weight of liver, fibrosis in portal triads, and ganglion size were similar in all groups. The number and size of flukes was greater in C2 than in T2 (p < 0.05). The histological examinations revealed a higher degree of parenchymatous fibrosis in T2 compared to C2 (p < 0.05). The administration of LPS from O. intermedium increased the nonspecific resistance against F. hepatica in experimentally infected sheep. PMID:23739808

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

    PubMed Central

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

    2011-01-01

    This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 μg/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 μg/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopolysaccharide (LPS) in the left or right radiocarpal joint. An epidural catheter was later introduced in the lumbosacral space and advanced up to the thoracolumbar level. The treatment started 6 h after synovitis induction. Lameness, maximum angle of carpal flexion, heart rate, systolic arterial pressure, respiratory rate, temperature, and intestinal motility were evaluated before LPS injection (baseline), 6 h after LPS injection (time 0), and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, and 24 h after treatments. Although the model of synovitis produced clear clinical signs of inflammation, the lameness scores in group C were different from the baseline for only up to 12 h. Both morphine and buprenorphine showed a reduction in the degree of lameness starting at 0.5 and 6 h, respectively. Reduced intestinal motility was observed at 0.5 h in group M and at 0.5 to 1 h in group B. Epidural morphine was a more effective analgesic that lasted for more than 12 h and without side effects. It was concluded that morphine would be a valuable analgesic option to alleviate joint pain in the thoracic limbs in ponies. PMID:21731186

  2. Esculetin attenuates lipopolysaccharide (LPS)-induced neuroinflammatory processes and depressive-like behavior in mice.

    PubMed

    Zhu, Lingpeng; Nang, Chen; Luo, Fen; Pan, Hong; Zhang, Kai; Liu, Jingyan; Zhou, Rui; Gao, Jin; Chang, Xiayun; He, He; Qiu, Yue; Wang, Jinglei; Long, Hongyan; Liu, Yu; Yan, Tianhua

    2016-09-01

    Esculetin is one of the major bioactive compounds of Cichorium intybus L. The main purpose of the present study was to investigate the effects and possible underlying mechanism of esculetin (Esc) on lipopolysaccharide (LPS)-induced neuroinflammatory processes and depressive-like behavior in mice. Mice were pretreatment with esculetin (Esc, 20, 40mg/kg, intragastric administration) and a positive control drug fluoxetine (Flu, 20mg/kg, intragastric administration) once daily for 7 consecutive days. At the 7th day, LPS (0.83mg/kg) was intraperitoneal injection 30min after drug administration. Higher dose (40mg/kg) of esculetin and fluoxetine significantly decreased immobility time in TST and FST. There was no significant effect on locomotor activity in mice by the drugs. Esculetin significantly reduced LPS-induced elevated levels of pro-inflammatory cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum and hippocampus. Esculetin attenuated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression by inhibiting nuclear factor-κB (NF-κB) pathway in hippocampus. In addition, neuroprotection of esculetin was attributed to the upregulations of Brain derived neurotrophic factor (BDNF) and phosphorylated tyrosine kinase B (p-TrkB) protein expression in hippocampus. The obtained results demonstrated that esculetin exhibited antidepressant-like effects which might be related to the inhibition of NF-κB pathway and the activation of BDNF/TrkB signaling. PMID:27133730

  3. Early expansion and expression of the lipopolysaccharide (LPS)-induced TNF-α factor (LITAF) gene family in the LPS-exposed monogonont rotifer Brachionus koreanus.

    PubMed

    Jeong, Chang-Bum; Lee, Jeong-Hyeon; Lee, Jae-Seong; Rhee, Jae-Sung

    2015-10-01

    To date, a single lipopolysaccharide-induced TNF-α factor (LITAF) homologue, mediating the expression of inflammatory cytokines including TNF-α in terms of host defense was identified in vertebrates and most invertebrates such as insects, mollusks, and crustaceans. However, LITAF gene family members have recently been characterized in only two mollusks, Crassostrea gigas and Mytilus galloprovincialis. Although a large gene family expansion of LITAF homologues was observed in the nematode Caenorhabditis elegans, the amino acid sequences encoded by the C. elegans LITAF homologue have low similarities to other LITAF gene family members. In this study, three LITAF genes were identified in the monogonont rotifer Brachionus koreanus. In silico analyses of B. koreanus LITAF genes of conserved domains and phylogenetic relationships supported gene annotations that indicated that LITAF is involved in innate immunity in primitive rotifers. To examine transcriptional sensitivity of B. koreanus LITAF genes, the rotifers were exposed to different concentrations of lipopolysaccharide (LPS). Transcriptional levels of LITAF1 and LITAF2 gene were significantly upregulated dose- and time-dependently in response to LPS exposure for 24 h. LPS exposure induced glutathione (GSH) depletion and antioxidant enzyme activity levels for 24 h in B. koreanus. These results suggested that the B. koreanus LITAF gene family has potential sensitivities directly and/or indirectly to immune stimulator-triggered oxidative stress. PMID:26056818

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

    PubMed

    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. PMID:26828112

  5. [Effect of paeoniflorin on oxidative stress and energy metabolism in mice with lipopolysaccharide (LPS)-induced brain injury].

    PubMed

    Liu, Ling; Qiu, Xiang-jun; He, Su-na; Yang, Hui; Wang, Deng; Yang, Xue-mei

    2015-07-01

    Paeoniflorin is the main active ingredient of Chinese herbaceous peony. This study is to investigate the protective effect of paeoniflorin (Pae) on acute brain damage induced by lipopolysaccharide (LPS) in mice. The mice were randomly assigned to the normal control, model control (LPS), as well as groups of paeoniflorin and lipopolysaccharide (Pae + LPS). Then the mice were administered intraperitioneally with normal saline or Pae (10, 30 mg · kg(-1)) once daily for 6 d. One hour after intrapertioneally treatment on the seventh day, each group were injected LPS (5 mg · kg(-1)) to establish the endotoxin lipopolysaccharide inflammation model except the normal group. The mice were sacrificed after 6 h and the brain homogenates were prepared and measured. The malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), hydrogen peroxide (H2O2), succinatedehydrogenase (SDH), Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase were dectected by the colorimetric method. The levels of HO-1 and Nrf2 protein in subcellular fractions of brain tissue were detected by Western blot. The results demonstrated that the administration with paeoniflorin reduced the levels of the MDA production; significantly increase the activities of antioxidant enzyme (SOD and GSH-PX). In addition, paeoniflorin could enhance the total antioxidant capacity, decrease the level of H2O2, and increase the activities of SDH, Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase. Furthermore, paeoniflorin can increase the expression of HO-1 and activate the nuclear transfer of Nrf2. Taking together, these findings suggest that paeoniflorin alleviate the acute inflammation in mice brain damage induced by LPS, which is related with its antioxidant effect and improvement of energy metabolism. PMID:26666042

  6. Rosiglitazone, a Peroxisome Proliferator-Activated Receptor (PPAR)-γ Agonist, Attenuates Inflammation Via NF-κB Inhibition in Lipopolysaccharide-Induced Peritonitis.

    PubMed

    Zhang, Yun-Fang; Zou, Xun-Liang; Wu, Jun; Yu, Xue-Qing; Yang, Xiao

    2015-12-01

    We assessed the anti-inflammatory effect of peroxisome proliferator-activated receptor (PPAR)-γ agonist, rosiglitazone, in a lipopolysaccharide (LPS)-induced peritonitis rat model. LPS was intraperitoneally injected into rats to establish peritonitis model. Male Sprague-Dawley (SD) rats were assigned to normal saline (the solvent of LPS), LPS, rosiglitazone plus LPS, and rosiglitazone alone. A simple peritoneal equilibrium test was performed with 20 ml 4.25 % peritoneal dialysis fluid. We measured the leukocyte count in dialysate and ultrafiltration volume. Peritoneal membrane histochemical staining was performed, and peritoneal thickness was assessed. CD40 and intercellular adhesion molecule-1 messenger RNA (ICAM-1 mRNA) levels in rat visceral peritoneum were detected by reverse transcription (RT)-PCR. IL-6 in rat peritoneal dialysis effluent was measured using enzyme-linked immunosorbent assay. The phosphorylation of NF-κB-p65 and IκBα was analyzed by Western blot. LPS administration resulted in increased peritoneal thickness and decreased ultrafiltration volume. Rosiglitazone pretreatment significantly decreased peritoneal thickness. In addition to CD40 and ICAM-1 mRNA expression, the IL-6, p-p65, and p-IκBα protein expressions were enhanced in LPS-administered animals. Rosiglitazone pretreatment significantly decreased ICAM-1 mRNA upregulation, secretion of IL-6 protein, and phosphorylation of NF-κB-p65 and IκBα without decreasing CD40 mRNA expression. Rosiglitazone has a protective effect in peritonitis, simultaneously decreasing NF-κB phosphorylation, suggesting that NF-κB signaling pathway mediated peritoneal inflammation induced by LPS. PPAR-γ might be considered a potential therapeutic target against peritonitis. PMID:26047949

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

    PubMed Central

    Kang, Ping; Zhang, Lili; Hou, Yongqing; Ding, Binying; Yi, Dan; Wang, Lei; Zhu, Huiling; Liu, Yulan; Yin, Yulong; Wu, Guoyao

    2014-01-01

    This trail was conducted to study the effect of L-proline on the growth performance, and blood parameter in the weaned lipopolysaccharide (LPS)-challenged pigs. Thirty six pigs (9.13±0.85 kg) were assigned randomly to dietary treatments in a 2×3 factorial arrangement in a 20-d growth assay. Factors were intraperitoneal injection with saline or LPS, and three dietary L-proline supplement levels (0%, 0.5%, or 1.0%). On d 10, blood samples were collected at 3 h after LPS (100 μg LPS/kg body weight [BW]) or saline injection. On d 20 of the trial, all pigs were orally administrated D-xylose (0.1 g/kg BW) at 2 h, and blood samples were collected at 3 h after LPS or saline injection. As a result, dietary supplementation with 0.5% proline had a tendency to increase average daily gain (ADG) in piglets during d 10 to 20 (p = 0.088). Without LPS challenge, dietary supplementation with 1.0% proline had no effect on growth hormone (GH) concentrations on d 10 (p>0.05), but decreased it after LPS challenge (p<0.05). There was LPS challenge×proline interaction for GH concentrations on d 10 (p<0.05). Dietary supplementation with 1.0% proline decreased glucagon concentration on d 10 after LPS challenge (p<0.05). In addition, dietary supplementation with proline increased superoxide dismutase (SOD) activity significantly on d 10 and 20 (p<0.05), and 1.0% proline increased heat shock proteins-70 concentration on d 10 (p<0.05). Moreover, proline supplementation increased diamine oxidase (DAO) concentrations after LPS challenge (p<0.05). There was LPS challenge×proline interaction for DAO (p<0.05). Furthermore, dietary supplementation with 1.0% proline increased the D-xylose level when no LPS challenge (p<0.05). These results indicate that proline supplementation could improve growth performance, increase SOD activities, and has a positive effect on the gastrointestinal tract digestibility in early weaned pigs. PMID:25083109

  8. Comparison of Gene Expression by Sheep and Human Blood Stimulated with the TLR4 Agonists Lipopolysaccharide and Monophosphoryl Lipid A

    PubMed Central

    Enkhbaatar, Perenlei; Nelson, Christina; Salsbury, John R.; Carmical, Joseph R.; Torres, Karen E. O.; Herndon, David; Prough, Donald S.; Luan, Liming; Sherwood, Edward R.

    2015-01-01

    Background Animal models that mimic human biology are important for successful translation of basic science discoveries into the clinical practice. Recent studies in rodents have demonstrated the efficacy of TLR4 agonists as immunomodulators in models of infection. However, rodent models have been criticized for not mimicking important characteristics of the human immune response to microbial products. The goal of this study was to compare genomic responses of human and sheep blood to the TLR4 agonists lipopolysaccharide (LPS) and monophosphoryl lipid A (MPLA). Methods Venous blood, withdrawn from six healthy human adult volunteers (~ 28 years old) and six healthy adult female sheep (~3 years old), was mixed with 30 μL of PBS, LPS (1μg/mL) or MPLA (10μg/mL) and incubated at room temperature for 90 minutes on a rolling rocker. After incubation, 2.5 mL of blood was transferred to Paxgene Blood RNA tubes. Gene expression analysis was performed using an Agilent Bioanalyzer with the RNA6000 Nano Lab Chip. Agilent gene expression microarrays were scanned with a G2565 Microarray Scanner. Differentially expressed genes were identified. Results 11,431 human and 4,992 sheep probes were detected above background. Among them 1,029 human and 175 sheep genes were differentially expressed at a stringency of 1.5-fold change (p<0.05). Of the 175 sheep genes, 54 had a known human orthologue. Among those genes, 22 had > 1.5-fold changes in human samples. Genes of major inflammatory mediators, such as IL-1, IL-6 and IL-8, TNF alpha, NF-kappaB, ETS2, PTGS2, PTX3, CXCL16, KYNU, and CLEC4E were similarly (>2-fold) upregulated by LPS and MPLA in both species. Conclusion The genomic responses of peripheral blood to LPS and MPLA in sheep are quite similar to those observed in humans, supporting the use of the ovine model for translational studies that mimic human inflammatory diseases and the study of TLR-based immunomodulators. PMID:26640957

  9. The influence of TLR4 agonist lipopolysaccharides on hepatocellular carcinoma cells and the feasibility of its application in treating liver cancer

    PubMed Central

    Gu, Junsheng; Sun, Ranran; Shen, Shen; Yu, Zujiang

    2015-01-01

    Objective This study was designed to explore the influence of Toll-like receptor 4 (TLR4) agonist lipopolysaccharides (LPS) on liver cancer cell and the feasibility to perform liver cancer adjuvant therapy. Methods Human liver cancer cell lines HepG2, H7402, and PLC/PRF/5 were taken as models, and the expression of TLRs mRNA was detected by real time-polymerase chain reaction method semiquantitatively. WST-1 method was used to detect the influence of LPS on the proliferation ability of liver cancer cells; propidium iodide (PI) single staining and Annexin V/PI double staining were used to test the influence of LPS on the cell cycle and apoptosis, respectively, on human liver cancer cell line H7402. Fluorescent quantitative polymerase chain reaction and Western blot method were used to determine the change of expression of Cyclin D1. Results The results demonstrated that most TLRs were expressed in liver cancer cells; stimulating TLR4 by LPS could upregulate TLR4 mRNA and the protein level, activate NF-κB signaling pathway downstream of TLR4, and mediate the generation of inflammatory factors IL-6, IL-8, and TNF-α; LPS was found to be able to strengthen the proliferation ability of liver cancer cells, especially H7402 cells; the expression of Cyclin D1 rose and H7402 cells were promoted to transit from G1 stage to S stage under the stimulation of LPS, but cell apoptosis was not affected. It was also found that LPS was able to activate signal transducer and activator of transcription -3 (STAT3) signaling pathway in H7402 cells and meanwhile significantly increase the initiation activity of STAT3; proliferation promoting effect of LPS to liver cancer cells remarkably lowered once STAT3 was blocked or inhibited. Conclusion Thus, TLR4 agonist LPS is proved to be able to induce liver cancer cells to express inflammation factors and mediate liver cancer cell proliferation and generation of multidrug resistance by activating the cyclooxygenase-2/prostaglandin signal axis

  10. Induction of long-term lipopolysaccharide tolerance by an agonistic monoclonal antibody to the toll-like receptor 4/MD-2 complex.

    PubMed

    Ohta, Shoichiro; Bahrun, Uleng; Shimazu, Rintaro; Matsushita, Hidetomo; Fukudome, Kenji; Kimoto, Masao

    2006-10-01

    We have established an agonistic monoclonal antibody, UT12, that induces stimulatory signals comparable to those induced by lipopolysaccharide (LPS) through Toll-like receptor 4 and MD-2. UT12 activated nuclear factor kappaB and induced the production of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) in peritoneal exudative cells. In addition, mice injected with UT12 rapidly fell into endotoxin shock concomitant with the augmentation of serum TNF-alpha and IL-6 levels, followed by death within 12 h. On the other hand, when the mice were pretreated with a sublethal dose of UT12, the mice survived the subsequent lethal LPS challenges, with significant suppression of serum TNF-alpha and IL-6, indicating that UT12 induced tolerance against LPS. This effect of UT12 was maintained for at least 9 days. In contrast, the tolerance induced by LPS continued for less than 3 days. These results illuminate a novel potential therapeutic strategy for endotoxin shock by the use of monoclonal antibodies against the Toll-like receptor 4/MD-2 complex. PMID:17028215

  11. Influence of temperament on inflammatory cytokine responses of cattle to a lipopolysaccharide (LPS) challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We previously reported that temperament influenced rectal temperature, sickness scores, and cortisol and epinephrine concentrations following an LPS challenge. Temperamental bulls displayed less sickness, fever and less of an epinephrine response 1 hour after an LPS challenge when compared to calm a...

  12. Differential response to lipopolysaccharide (LPS) and corticotrophin-releasing hormone (CRH) on immune parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of LPS and CRH to elicit immune responses was compared. Brahman heifers were transported from Overton, TX, to Lubbock, TX, were fitted with jugular catheters and separated into 2 treatments groups, LPS (0.25 microgram/kg BW; n=6; 194±11 kg) or CRH (0.5 microgram/kg BW; n=6; 202±9 kg). Bl...

  13. Lipopolysaccharide-binding protein is bound and internalized by host cells and colocalizes with LPS in the cytoplasm: Implications for a role of LBP in intracellular LPS-signaling.

    PubMed

    Kopp, Franziska; Kupsch, Sarah; Schromm, Andra B

    2016-04-01

    The lipopolysaccharide-binding protein (LBP) is critically involved in innate immune responses to Gram-negative infections. We show here that human peripheral blood-derived monocytes, but not lymphocytes, stain positive for endogenous LBP on the cell surface. Studies on human macrophages demonstrate LBP binding at normal serum concentrations of 1-10 μg/ml. Binding was increased in a concentration-dependent manner by lipopolysaccharide (LPS). Fluorescence quenching experiments and confocal microscopy revealed constitutive and LPS-induced internalization of LBP by macrophages. Experiments with macrophages and HEK293 cell lines showed that binding and uptake of LBP do not depend on the LPS receptors CD14 and TLR4/MD-2. Fractionation of Triton X-100 solubilized cytoplasmic membranes revealed that LBP was primarily localized in non-raft domains under resting conditions. Cellular LPS stimulation elevated LBP levels and induced enrichment in fractions marking the transition between non-raft and raft domains. LBP was found to colocalize with LPS at the cytoplasmic membrane and in intracellular compartments of macrophages. In macrophages stimulated with LPS and ATP for inflammasome activation, LBP was observed in close vicinity to activated caspases. Furthermore, LBP conferred IL-1β production by LPS in the absence of ATP. These data establish that LBP serves not only as an extracellular LPS shuttle but in addition facilitates intracellular transport of LPS. This observation adds a new function to this central immune regulator of LPS biology and raises the possibility for a role of LBP in the delivery of LPS to TLR4-independent intracellular receptors. PMID:26804480

  14. Lipopolysaccharide (LPS)-Induced Biliary Epithelial Cell NRas Activation Requires Epidermal Growth Factor Receptor (EGFR)

    PubMed Central

    Trussoni, Christy E.; Tabibian, James H.; Splinter, Patrick L.; O’Hara, Steven P.

    2015-01-01

    Cholangiocytes (biliary epithelial cells) actively participate in microbe-induced proinflammatory responses in the liver and contribute to inflammatory and infectious cholangiopathies. We previously demonstrated that cholangiocyte TLR-dependent NRas activation contributes to proinflammatory/ proliferative responses. We test the hypothesis that LPS-induced activation of NRas requires the EGFR. SV40-transformed human cholangiocytes (H69 cells), or low passage normal human cholangiocytes (NHC), were treated with LPS in the presence or absence of EGFR or ADAM metallopeptidase domain 17 (TACE) inhibitors. Ras activation assays, quantitative RT-PCR, and proliferation assays were performed in cells cultured with or without inhibitors or an siRNA to Grb2. Immunofluorescence for phospho-EGFR was performed on LPS-treated mouse samples and specimens from patients with primary sclerosing cholangitis, primary biliary cirrhosis, hepatitis C, and normal livers. LPS-treatment induced an association between the TLR/MyD88 and EGFR/Grb2 signaling apparatus, NRas activation, and EGFR phosphorylation. NRas activation was sensitive to EGFR and TACE inhibitors and correlated with EGFR phosphorylation. The TACE inhibitor and Grb2 depletion prevented LPS-induced IL6 expression (p<0.05) and proliferation (p<0.01). Additionally, cholangiocytes from LPS-treated mouse livers and human primary sclerosing cholangitis (PSC) livers exhibited increased phospho-EGFR (p<0.01). Moreover, LPS-induced mouse cholangiocyte proliferation was inhibited by concurrent treatment with the EGFR inhibitor, Erlotinib. Our results suggest that EGFR is essential for LPS-induced, TLR4/MyD88-mediated NRas activation and induction of a robust proinflammatory cholangiocyte response. These findings have implications not only for revealing the signaling potential of TLRs, but also implicate EGFR as an integral component of cholangiocyte TLR-induced proinflammatory processes. PMID:25915403

  15. Lipopolysaccharide (LPS)-Induced Biliary Epithelial Cell NRas Activation Requires Epidermal Growth Factor Receptor (EGFR).

    PubMed

    Trussoni, Christy E; Tabibian, James H; Splinter, Patrick L; O'Hara, Steven P

    2015-01-01

    Cholangiocytes (biliary epithelial cells) actively participate in microbe-induced proinflammatory responses in the liver and contribute to inflammatory and infectious cholangiopathies. We previously demonstrated that cholangiocyte TLR-dependent NRas activation contributes to proinflammatory/ proliferative responses. We test the hypothesis that LPS-induced activation of NRas requires the EGFR. SV40-transformed human cholangiocytes (H69 cells), or low passage normal human cholangiocytes (NHC), were treated with LPS in the presence or absence of EGFR or ADAM metallopeptidase domain 17 (TACE) inhibitors. Ras activation assays, quantitative RT-PCR, and proliferation assays were performed in cells cultured with or without inhibitors or an siRNA to Grb2. Immunofluorescence for phospho-EGFR was performed on LPS-treated mouse samples and specimens from patients with primary sclerosing cholangitis, primary biliary cirrhosis, hepatitis C, and normal livers. LPS-treatment induced an association between the TLR/MyD88 and EGFR/Grb2 signaling apparatus, NRas activation, and EGFR phosphorylation. NRas activation was sensitive to EGFR and TACE inhibitors and correlated with EGFR phosphorylation. The TACE inhibitor and Grb2 depletion prevented LPS-induced IL6 expression (p<0.05) and proliferation (p<0.01). Additionally, cholangiocytes from LPS-treated mouse livers and human primary sclerosing cholangitis (PSC) livers exhibited increased phospho-EGFR (p<0.01). Moreover, LPS-induced mouse cholangiocyte proliferation was inhibited by concurrent treatment with the EGFR inhibitor, Erlotinib. Our results suggest that EGFR is essential for LPS-induced, TLR4/MyD88-mediated NRas activation and induction of a robust proinflammatory cholangiocyte response. These findings have implications not only for revealing the signaling potential of TLRs, but also implicate EGFR as an integral component of cholangiocyte TLR-induced proinflammatory processes. PMID:25915403

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

    PubMed

    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. PMID:26811056

  17. The effect of lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) on whole blood oxidative response as assessed by luminol-amplified chemiluminescence in dairy cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The differences between lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) on whole blood oxidative response using luminol-amplified chemiluminescence (CL) are currently unknown in cattle. Luminol-dependent CL measures the amount of reactive oxygen species released from leukocytes a...

  18. Effects of transportation and lipopolysaccharide (LPS) challenge on vaginal temperature in crossbred heifer calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effects of transportation and subsequent LPS challenge on heifer vaginal temperature (Tvag). Brahman x British heifers (n=44) of from Raymond, MS, were weaned and acclimated to a high roughage diet fed in GrowSafe® bunks for 25 d. Heifers were blocked by body weight (BW) and...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Temporal pattern of the stress hormone and cytokine response in pigs following a lipopolysaccharide (LPS) challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study assessed the pattern of immune and stress response following a LPS challenge. Crossbred pigs (n=28 pigs, 2 males and 2 females from 7 litters) were obtained at weaning (21 to 28 d of age). Pigs were transferred to a climate controlled facility, placed into individual pens and allowed ad l...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  2. Effects of transportation and lipopolysaccharide (LPS) challenge on body weight and feed intake of crossbred heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to examine the effects of transportation and LPS challenge on feed intake (FI) and body weight (BW) of calves. Brahman x British heifers (n=44) from Raymond, MS, were weaned and acclimated to a high roughage diet fed in GrowSafe® bunks for 25 d. Heifers were blocked by BW...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. The symbiotic defect of Rhizobium meliloti exopolysaccharide mutants is suppressed by lpsZ sup + , a gene involved in lipopolysaccharide biosynthesis

    SciTech Connect

    Williams, M.N.V.; Klein, S.; Signer, E.R. ); Hollingsworth, R.I. )

    1990-05-01

    exo mutants of Rhizobium meliloti SU47, which fail to secrete acidic extracellular polysaccharide (EPS), induce Fix{sup {minus}} nodules on alfalfa. However, mutants of R. meliloti Rm41 carrying the same exo lesions induce normal Fix{sup +} nodules. The authors show that such induction is due to a gene from strain Rm41, which they call lpsZ{sup +}, that is missing in strain SU47. lpsZ{sup +} does not restore EPS production but instead alters the composition an structure of lipopolysaccharide. In both SU47 and Rm41, either lpsZ{sup +} or exo{sup +} is sufficient for normal nodulation. This suggests that in R. meliloti EPS and lipopolysaccharide can perform the same function in nodule development.

  5. Pulmonary hypertensive responses of broilers to bacterial lipopolysaccharide (LPS): evaluation of LPS source and dose, and impact of pre-existing pulmonary hypertension and cellulose micro-particle selection.

    PubMed

    Chapman, M E; Wang, W; Erf, G F; Wideman, R F

    2005-03-01

    Previous studies demonstrated that bacterial lipopolysaccharide (LPS, endotoxin) triggers pulmonary vasoconstriction leading to pulmonary hypertension (PHS, ascites) in broilers. The lungs of broilers are constantly challenged with LPS that can trigger pulmonary vasoconstriction. Among broilers from a single genetic line, some individuals respond to LPS with large increases in pulmonary arterial pressure (PAP), whereas others fail to exhibit any response to the same supramaximal dose of LPS. In the present study we evaluated the impact of a variety of factors on the magnitude of the PAP response of male broilers to LPS, including: (1) the role of the initial PAP (low vs. high initial PAP); (2) the source of the LPS (Salmonella typhimurium vs. Escherichia coli); (3) the dose of LPS (0.02, 0.1, and 0.5 mg/kg of BW); and (4) the role of micro-particle selection for improved pulmonary vascular capacity (cellulose survivors vs. saline-injected controls). Broilers in the low initial PAP group (21 +/- 0.34 mmHg, mean +/- SEM) did not differ in their pulmonary hypertensive response to LPS compared with broilers in the high initial PAP group (29 +/- 0.55 mmHg, mean +/- SEM). Lipopolysaccharide from S. typhimurium elicited pulmonary hypertensive responses qualitatively similar to those elicited by E. coli LPS. A detailed evaluation revealed that an LPS dose of 0.1 mg/kg of BW elicits a maximal pulmonary hypertensive response in male broilers, and broilers selected by micro-particle injection for a robust pulmonary vascular capacity did not differ in their pulmonary hypertensive response to LPS compared with unselected broilers. This research confirms that the variable pulmonary hypertensive responses among broilers cannot be attributed to the source or dosage of LPS, or to differences in the baseline pulmonary arterial pressure or micro-particle selection before injecting LPS. These findings are consistent with the hypothesis that innate rather than acquired variability may

  6. Protective effects of carnosine alone and together with alpha-tocopherol on lipopolysaccharide (LPS) plus ethanol-induced liver injury.

    PubMed

    Kalaz, Esra Betül; Aydın, A Fatih; Doğan-Ekici, Işın; Çoban, Jale; Doğru-Abbasoğlu, Semra; Uysal, Müjdat

    2016-03-01

    The aim of this study was to investigate the effect of carnosine (CAR) alone and together with vitamin E (Vit E) on alcoholic steatohepatitis (ASH) in rats. ASH was induced by ethanol (3 times; 5 g/kg; 12 h intervals, via gavage), followed by a single dose of lipopolysaccharide (LPS; 10 mg/kg; i.p.). CAR (250 mg/kg; i.p.) and Vit E (200 mg D-α-tocopherol/kg; via gavage) were administered 30 min before and 90 min after the LPS injection. CAR treatment lowered high serum transaminase activities together with hepatic histopathologic improvements in rats with ASH. Reactive oxygen species formation, malondialdehyde levels, myeloperoxidase activities and transforming growth factor β1 (TGF-β1) and collagen 1α1 (COL1A1) expressions were observed to decrease. These improvements were more remarkable in CAR plus Vit E-treated rats. Our results indicate that CAR may be effective in suppressing proinflammatory, prooxidant, and profibrotic factors in the liver of rats with ASH. PMID:26773358

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

    PubMed

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

    2015-08-01

    Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%-42% total fatty acids as n-3 PUFA and 5%-7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p < 0.05) and IL-8 (p < 0.05) while that of P. lutheri inhibited IL-6 (p < 0.01) production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1) by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases. PMID:26308008

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

    PubMed Central

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

    2015-01-01

    Algae contain a number of anti-inflammatory bioactive compounds such as omega-3 polyunsaturated fatty acids (n-3 PUFA) and chlorophyll a, hence as dietary ingredients, their extracts may be effective in chronic inflammation-linked metabolic diseases such as cardiovascular disease. In this study, anti-inflammatory potential of lipid extracts from three red seaweeds (Porphyra dioica, Palmaria palmata and Chondrus crispus) and one microalga (Pavlova lutheri) were assessed in lipopolysaccharide (LPS)-stimulated human THP-1 macrophages. Extracts contained 34%–42% total fatty acids as n-3 PUFA and 5%–7% crude extract as pigments, including chlorophyll a, β-carotene and fucoxanthin. Pretreatment of the THP-1 cells with lipid extract from P. palmata inhibited production of the pro-inflammatory cytokines interleukin (IL)-6 (p < 0.05) and IL-8 (p < 0.05) while that of P. lutheri inhibited IL-6 (p < 0.01) production. Quantitative gene expression analysis of a panel of 92 genes linked to inflammatory signaling pathway revealed down-regulation of the expression of 14 pro-inflammatory genes (TLR1, TLR2, TLR4, TLR8, TRAF5, TRAF6, TNFSF18, IL6R, IL23, CCR1, CCR4, CCL17, STAT3, MAP3K1) by the lipid extracts. The lipid extracts effectively inhibited the LPS-induced pro-inflammatory signaling pathways mediated via toll-like receptors, chemokines and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling molecules. These results suggest that lipid extracts from P. lutheri, P. palmata, P. dioica and C. crispus can inhibit LPS-induced inflammatory pathways in human macrophages. Therefore, algal lipid extracts should be further explored as anti-inflammatory ingredients for chronic inflammation-linked metabolic diseases. PMID:26308008

  9. Influence of lipopolysaccharides and lipids A from some marine bacteria on spontaneous and Escherichia coli LPS-induced TNF-alpha release from peripheral human blood cells.

    PubMed

    Vorobeva, E V; Krasikova, I N; Solov'eva, T F

    2006-07-01

    Some endotoxic properties of lipopolysaccharides (LPS) and lipids A (LA) from the marine bacteria Marinomonas communis ATCC 27118(T), Marinomonas mediterranea ATCC 700492(T), and Chryseobacterium indoltheticum CIP 103168(T) were studied. The preparations tested were shown to have high 50% lethal doses (4 microg per mouse for LPS from M. mediterranea and more than 12 microg per mouse for two other LPS and LA from C. indoltheticum) and were moderate (371 +/- 37 pg/ml at 10 microg/ml of C. indoltheticum LPS), weak (148 +/- 5 pg/ml at 1 microg/ml of M. mediterranea LPS), and zero (LA and LPS from M. communis and LA from C. indoltheticum) inducers of tumor necrosis factor alpha (TNF-alpha) release from peripheral human blood cells. The capacity of the LA and LPS samples from marine bacteria to inhibit TNF-alpha release induced by LPS from Escherichia coli O55 : B5 (10 ng/ml) was also studied. PMID:16903830

  10. Toll-Like Receptor 2- and 6-Mediated Stimulation by Macrophage-Activating Lipopeptide 2 Induces Lipopolysaccharide (LPS) Cross Tolerance in Mice, Which Results in Protection from Tumor Necrosis Factor Alpha but in Only Partial Protection from Lethal LPS Doses

    PubMed Central

    Deiters, Ursula; Gumenscheimer, Marina; Galanos, Chris; Mühlradt, Peter F.

    2003-01-01

    Patients or experimental animals previously exposed to lipopolysaccharide (LPS) become tolerant to further LPS challenge. We investigated the potential of the macrophage-activating lipopeptide 2 (MALP-2) to induce in vivo cross tolerance to tumor necrosis factor alpha (TNF-α) and LPS. MALP-2-induced tolerance could be of practical interest, as MALP-2 proved much less pyrogenic in rabbits than LPS. Whereas LPS signals via Toll-like receptor 4 (TLR4), MALP-2 uses TLR2 and TLR6. LPS-mediated cytokine release was studied in mice pretreated with intraperitoneal injections of MALP-2. No biologically active TNF-α could be detected in the serum of MALP-2-treated animals when challenged with LPS 24 or 72 h later, whereas suppression of LPS-dependent interleukin (IL)-6 lasted for only 24 h. Protection from lethal TNF-α shock was studied in galactosamine-treated mice. Dose dependently, MALP-2 prevented death from lethal TNF-α doses in TLR4−/− but not in TLR2−/− mice, with protection lasting from 5 to 24 h. To assay protection from LPS, mice were pretreated with MALP-2 doses of up to 10 μg. Five and 24 h later, the animals were simultaneously sensitized and challenged by intravenous coinjection of galactosamine and a lethal dose of 50 ng of LPS. There was only limited protection (four of seven mice survived) when mice were challenged 5 h after MALP-2 pretreatment, and no protection when mice were challenged at later times. The high effectiveness of MALP-2 in suppressing TNF-α, the known ways of biological inactivation, and low pyrogenicity make MALP-2 a potential candidate for clinical use. PMID:12874325

  11. Identification of a new anti-LPS agent, geniposide, from Gardenia jasminoides Ellis, and its ability of direct binding and neutralization of lipopolysaccharide in vitro and in vivo.

    PubMed

    Zheng, Xinchuan; Yang, Dong; Liu, Xin; Wang, Ning; Li, Bin; Cao, Hongwei; Lu, Yongling; Wei, Guo; Zhou, Hong; Zheng, Jiang

    2010-10-01

    Lipopolysaccharide (LPS/endotoxin) is a key pathogen recognition molecule for sepsis. Currently, one of the therapeutic approaches for severe sepsis is focusing on the neutralization of LPS, and clinical trials have shown a lot of traditional Chinese herbs possess anti-sepsis function. Herein, to elucidate the bioactive components of traditional Chinese herbs that can neutralize LPS, the lipid A-binding abilities of sixty herbs were tested using affinity biosensor technology. The aqueous extract of Gardenia jasminoides Ellis, traditionally used to treat inflammation in Asian countries for centuries, was further investigated. Subsequently, a monomer, identified as geniposide, was isolated. In vitro, geniposide was found to directly bind LPS and neutralize LPS. It dose-dependently inhibited cytokines release from RAW264.7 cells induced by LPS without affecting the cell viability, and inhibited TNF-α mRNA expression up-regulated by LPS. However, geniposide did not decrease TNF-α release induced by CpG DNA, Poly I:C or IL-1β. Significantly, geniposide dose-dependently down-regulated TLR4 mRNA expression up-regulated by LPS, and suppressed the phosphorylations of p38 MAKP induced by LPS but not by IL-1β. In vivo, geniposide (40mg/kg) could significantly protect mice challenge with lethal heat-killed E. coli, and dose-dependently decreased the level of serum endotoxin which was tightly associated with the cytokine levels in endotoxemia mice. In summary, we successfully isolated geniposide from G. jasminoides Ellis. Geniposide directly bound LPS and neutralized LPS in vitro, and significantly protected sepsis model mice. Therefore, geniposide could be as a useful lead compound for anti-sepsis drug development. PMID:20655404

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

    PubMed

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

    2015-05-01

    In this work, we primed Galleria mellonella larvae by haemocoel injection of lipopolysaccharide (LPS) extracted from Photorhabdus luminescens TT01 to determine whether bacterial LPS can induce enhanced immune protection (recently called immune priming). We also analyzed the relationship between changes in the levels of innate immune elements and the degree of enhanced immune protection in the larvae at designated time points after priming. The larvae that received experimental doses (20.0, 10.0 and 5.0μg per larva) of LPS demonstrated increased resistance against lethal challenge with P. luminescens TT01; the degree and period of protection correlated positively with the priming dose. These results indicated that the P. luminescens TT01 LPS could induce typical immune priming in G. mellonella. Moreover, the levels of innate immune parameters (i.e. haemocyte density, phagocytosis, haemocyte encapsulation ability, and antibacterial activity of cell-free haemolymph) and endogenous enzyme activities (i.e. acid phosphatase, ACP; alkaline phosphatase, AKP; superoxide dismutase, SOD and lysozyme, LSZ) were significantly increased following priming of the larvae with LPS, whereas the activities of peroxidase (POD) and catalase (CAT) were significantly decreased. All of the parameters examined changed in a dose- and time-dependent manner. This study demonstrated that G. mellonella larvae could modulate their immune responses based on different doses of LPS used for priming, and that priming phenomenon in G. mellonella larvae elicited by LPS was mediated by the innate immune elements and enzyme activity. PMID:25796336

  13. Thiazolidinedione (pioglitazone) blocks P. gingivalis- and F. nucleatum, but not E. coli, lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) production in adipocytes.

    PubMed

    Yamaguchi, M; Nishimura, F; Naruishi, H; Soga, Y; Kokeguchi, S; Takashiba, S

    2005-03-01

    An elevated level of C-reactive protein (CRP) predicts the future development of coronary heart disease. Periodontitis appears to up-regulate CRP. CRP is produced by hepatocytes in response to interleukin-6 (IL-6). A major source of IL-6 in obese subjects is adipocytes. We hypothesized that lipopolysaccharide (LPS) from periodontal pathogens stimulated adipocytes to produce IL-6, and that the production was suppressed by the drugs targeted against insulin resistance, thiazolidinedione (pioglitazone), since this agent potentially showed an anti-inflammatory effect. Mouse 3T3-L1 adipocytes were stimulated with E. coli, P. gingivalis, and F. nucleatum LPS. The IL-6 concentration in culture supernatants was measured. All LPS stimulated adipocytes to produce IL-6. Although pioglitazone changed adipocyte appearance from large to small, and completely suppressed P. gingivalis and F. nucleatum LPS-induced IL-6 production, E. coli LPS-induced IL-6 production was not efficiently blocked. Thus, pioglitazone completely blocked periodontal-bacteria-derived LPS-induced IL-6 production in adipocytes, a major inducer of CRP. PMID:15723863

  14. Variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps) biosynthetic locus in Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice

    PubMed Central

    Patil, Prabhu B; Sonti, Ramesh V

    2004-01-01

    Background In animal pathogenic bacteria, horizontal gene transfer events (HGT) have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (LPS). As a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. Since LPS is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. Although LPS has been suggested as a potentiator of plant defense responses, interstrain variation at lps biosynthetic gene clusters has not been reported for any plant pathogenic bacterium. Results We report here the complete sequence of a 12.2 kb virulence locus of Xanthomonas oryzae pv. oryzae (Xoo) encoding six genes whose products are homologous to functions involved in LPS biosynthesis and transport. All six open reading frames (ORFs) have atypical G+C content and altered codon usage, which are the hallmarks of genomic islands that are acquired by horizontal gene transfer. The lps locus is flanked by highly conserved genes, metB and etfA, respectively encoding cystathionine gamma lyase and electron transport flavoprotein. Interestingly, two different sets of lps genes are present at this locus in the plant pathogens, Xanthomonas campestris pv. campestris (Xcc) and Xanthomonas axonopodis pv. citri (Xac). The genomic island is present in a number of Xoo strains from India and other Asian countries but is not present in two strains, one from India (BXO8) and another from Nepal (Nepal624) as well as the closely related rice pathogen, Xanthomonas oryzae pv. oryzicola (Xoor). TAIL-PCR analysis indicates that sequences related to Xac are present at the lps locus in both BXO8 and Nepal624. The Xoor strain has a hybrid lps gene cluster, with sequences at the metB and etfA ends, being most closely related to sequences from Xac and the tomato pathogen, Pseudomonas syringae pv. tomato respectively

  15. PF-04886847 (an inhibitor of plasma kallikrein) attenuates inflammatory mediators and activation of blood coagulation in rat model of lipopolysaccharide (LPS) - induced sepsis

    PubMed Central

    Kolte, D; Bryant, JW; Gibson, GW; Wang, J; Shariat-Madar, Z

    2016-01-01

    The plasma kallikrein-mediated proteolysis regulates both thrombosis and inflammation. Previous study has shown that PF-04886847 is a potent and competitive inhibitor of kallikrein, suggesting that it might be useful for the treatment of kallikrein-kinin mediated inflammatory and thrombotic disorders. In the rat model of lipopolysaccharide (LPS) -induced sepsis used in this study, pretreatment of rats with PF-04886847 (1 mg/kg) prior to LPS (10 mg/kg) prevented endotoxin-induced increase in granulocyte count in the systemic circulation. PF-04886847 significantly reduced the elevated plasma 6-keto PGF1α levels in LPS treated rats, suggesting that PF-04886847 could be useful in preventing hypotensive shock during sepsis. PF-04886847 did not inhibit LPS-induced increase in plasma TNF-α level. Pretreatment of rats with PF-04886847 prior to LPS did not attenuate endotoxin-induced decrease in platelet count and plasma fibrinogen levels as well as increase in plasma D-dimer levels. PF-04886847 did not protect the animals against LPS-mediated acute hepatic and renal injury and disseminated intravascular coagulation (DIC). Since prekallikrein (the zymogen form of plasma kallikrein) deficient patients have prolonged aPPT without having any bleeding disorder, the anti-thrombotic property and mechanism of action of PF-04886847 was assessed. In a rabbit balloon injury model designed to mimic clinical conditions of acute thrombotic events, PF-04886847 reduced thrombus mass dose-dependently. PF-04886847 (1 mg/kg) prolonged both activated partial thromboplastin time (aPTT) and prothrombin time (PT) in a dose-dependent manner. Although the findings of this study indicate that PF-04886847 possesses limited anti-thrombotic and anti-inflammatory effects, PF-04886847 may have therapeutic potential in other kallikrein-kinin mediated diseases. PMID:22352684

  16. Prebiotic administration normalizes lipopolysaccharide (LPS)-induced anxiety and cortical 5-HT2A receptor and IL1-β levels in male mice.

    PubMed

    Savignac, Helene M; Couch, Yvonne; Stratford, Michael; Bannerman, David M; Tzortzis, George; Anthony, Daniel C; Burnet, Philip W J

    2016-02-01

    The manipulation of the enteric microbiota with specific prebiotics and probiotics, has been shown to reduce the host's inflammatory response, alter brain chemistry, and modulate anxiety behaviour in both rodents and humans. However, the neuro-immune and behavioural effects of prebiotics on sickness behaviour have not been explored. Here, adult male CD1 mice were fed with a specific mix of non-digestible galacto-oligosaccharides (Bimuno®, BGOS) for 3 weeks, before receiving a single injection of lipopolysaccharide (LPS), which induces sickness behaviour and anxiety. Locomotor and marble burying activities were assessed 4h after LPS injection, and after 24h, anxiety in the light-dark box was assessed. Cytokine expression, and key components of the serotonergic (5-Hydroxytryptamine, 5-HT) and glutamatergic system were evaluated in the frontal cortex to determine the impact of BGOS administration at a molecular level. BGOS-fed mice were less anxious in the light-dark box compared to controls 24h after the LPS injection. Elevated cortical IL-1β concentrations in control mice 28 h after LPS were not observed in BGOS-fed animals. This significant BGOS×LPS interaction was also observed for 5HT2A receptors, but not for 5HT1A receptors, 5HT, 5HIAA, NMDA receptor subunits, or other cytokines. The intake of BGOS did not influence LPS-mediated reductions in marble burying behaviour, and its effect on locomotor activity was equivocal. Together, our data show that the prebiotic BGOS has an anxiolytic effect, which may be related to the modulation of cortical IL-1β and 5-HT2A receptor expression. Our data suggest a potential role for prebiotics in the treatment of neuropsychiatric disorders where anxiety and neuroinflammation are prominent clinical features. PMID:26476141

  17. Bioactive phytochemicals of leaf essential oils of Cinnamomum osmophloeum prevent lipopolysaccharide/D-galactosamine (LPS/D-GalN)-induced acute hepatitis in mice.

    PubMed

    Tung, Yu-Tang; Huang, Chi-Chang; Ho, Shang-Tse; Kuo, Yueh-Hsiung; Lin, Chi-Chen; Lin, Chien-Tsong; Wu, Jyh-Horng

    2011-08-10

    The purpose of this study was to investigate the bioactive phytochemicals of leaf essential oils of Cinnamomum osmophloeum on lipopolysaccharide/D-galactosamine (LPS/D-GalN)-induced acute hepatitis. The results revealed that post-treatment with 100 μmol/kg trans-cinnamaldehyde, (-)-aromadendrene, T-cadinol, or α-cadinol significantly decreased the aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) levels in serum. Moreover, both T-cadinol and α-cadinol treatments decreased the expressions of cleaved caspase-3 and cleaved poly-ADP ribose polymerase (PARP) in the liver tissues when compared with the LPS/D-GalN group. Liver histopathology also showed that silymarin, trans-cinnamaldehyde, (-)-aromadendrene, T-cadinol, or α-cadinol significantly reduced the incidence of liver lesions induced by LPS/D-GalN. These results suggest that the above phytochemicals exhibit potent hepatoprotection against LPS/D-GalN-induced liver damage in mice, and their hepatoprotective effects may be due to the modulation of anti-inflammatory activities. PMID:21699244

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

    PubMed

    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. PMID:25300227

  19. Anti-inflammatory effect of methanolic extract of Conyzacanadensis in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophage cells.

    PubMed

    Song, Jia-Le; Yi, Ruo-Kun; Gao, Yang

    2016-05-01

    The aim of this study was to investigate the potential anti-inflammatory effect of Conyzacanadeusis methanol extract (CME) using a cell model of RAW264.7 murine macrophage cell stimulated with lipopolysaccharide (LPS)(1μg/ml). Co-treatment with different concentrations (10, 50 and 100μg/ml) of CME was concentration-dependently reduced the LPS-induced generation of prostaglandin E2 (PGE2), nitric oxide (NO) tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6. In addition, CME also reduced the mRNA expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide (iNOS), TNF-α, IL-1β and IL-6 in LPS-stimulated RAW264.7 cells. These results suggested that CME showed an anti-inflammatory activity through reduced the mRNA expression of COX-2, iNOS, TNF-α IL-1β and IL-6 and also decreased the productions of PGE2, NO, TNF-α IL-1β and IL-6in LPS-stimulated RAW264.7 cells. PMID:27166556

  20. Hydration, Ionic Valence and Cross-Linking Propensities of Cations Determine the Stability of Lipopolysaccharide (LPS) Membranes

    SciTech Connect

    Nascimento, Agrinaldo; Pontes, Frederico J.; Lins, Roberto D.; Soares, Thereza A.

    2013-10-29

    The supra-molecular structure of LPS aggregates governs outer membrane permeability and activation of the host immune response during Gram-negative bacterial infections. Molecular dynamics simulations unveil at atomic resolution 10 the subtle balance between cation hydration and cross-link ability in modulating phase transitions of LPS membranes.

  1. Viscoelastic and ultrastructural characteristics of whole blood and plasma in Alzheimer-type dementia, and the possible role of bacterial lipopolysaccharides (LPS)

    PubMed Central

    Bester, Janette; Soma, Prashilla; Kell, Douglas B.; Pretorius, Etheresia

    2015-01-01

    Alzheimer-type dementia (AD) is a neurodegenerative disorder and the most common form of dementia. Patients typically present with neuro- and systemic inflammation and iron dysregulation, associated with oxidative damage that reflects in hypercoagulability. Hypercoagulability is closely associated with increased fibrin(ogen) and in AD patients fibrin(ogen) has been implicated in the development of neuroinflammation and memory deficits. There is still no clear reason precisely why (a) this hypercoagulable state, (b) iron dysregulation and (c) increased fibrin(ogen) could together lead to the loss of neuronal structure and cognitive function. Here we suggest an alternative hypothesis based on previous ultrastructural evidence of the presence of a (dormant) blood microbiome in AD. Furthermore, we argue that bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, might be the cause of the continuing and low-grade inflammation, characteristic of AD. Here, we follow an integrated approach, by studying the viscoelastic and ultrastructural properties of AD plasma and whole blood by using scanning electron microscopy, Thromboelastography (TEG®) and the Global Thrombosis Test (GTT®). Ultrastructural analysis confirmed the presence and close proximity of microbes to erythrocytes. TEG® analysis showed a hypercoagulable state in AD. TEG® results where LPS was added to naive blood showed the same trends as were found with the AD patients, while the GTT® results (where only platelet activity is measured), were not affected by the added LPS, suggesting that LPS does not directly impact platelet function. Our findings reinforce the importance of further investigating the role of LPS in AD. PMID:26462180

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  4. miR-146a is essential for lipopolysaccharide (LPS)-induced cross-tolerance against kidney ischemia/reperfusion injury in mice.

    PubMed

    Dai, Yan; Jia, Ping; Fang, Yi; Liu, Hong; Jiao, Xiaoyan; He, John C; Ding, Xiaoqiang

    2016-01-01

    MicroRNA-146a is one of most important microRNAs involved in development of endotoxin tolerance via (toll-like receptors) TLRs/ NF-κB pathway. In this study, we sought to identify the mechanistic role of miR-146a in mediating the protective effect of lipopolysaccharide (LPS) pretreatment on kidney ischemia/reperfusion injury. A locked nucleic acid-modified anti-miR-146a given before LPS treatment knocked down miR-146a expression and completely negated LPS-mediated protection against kidney ischemia/reperfusion injury. Knockdown of miR-146a resulted in significantly higher histopathological scores for tubular damage, expression of proinflammatory cytokines and chemokines, and neutrophil and macrophage infiltration. Furthermore, knockdown of miR-146a greatly up-regulated the protein levels of IL-1 receptor-associated kinase (IRAK-1) and tumor-necrosis factor (TNF) receptor-associated factor 6 (TRAF6), which are known target genes of miR-146a, leading to activation of NF-κB. Finally, elevation of nuclear translocation of NF-κB p65/p50 and caspase-3 expression, degradation of cytosolic IkBα and BcL-xL, and substantially exacerbation of tubular cell apoptosis were inversely correlated with miR-146a expression. Taken together, our results identify that miR146a exerts a kidney protective effect through negative regulation of acute inflammatory response by suppressing NF-κB activation and proinflammatory genes expression. PMID:27250735

  5. miR-146a is essential for lipopolysaccharide (LPS)-induced cross-tolerance against kidney ischemia/reperfusion injury in mice

    PubMed Central

    Dai, Yan; Jia, Ping; Fang, Yi; Liu, Hong; Jiao, Xiaoyan; He, John C.; Ding, Xiaoqiang

    2016-01-01

    MicroRNA-146a is one of most important microRNAs involved in development of endotoxin tolerance via (toll-like receptors) TLRs/ NF-κB pathway. In this study, we sought to identify the mechanistic role of miR-146a in mediating the protective effect of lipopolysaccharide (LPS) pretreatment on kidney ischemia/reperfusion injury. A locked nucleic acid–modified anti-miR-146a given before LPS treatment knocked down miR-146a expression and completely negated LPS-mediated protection against kidney ischemia/reperfusion injury. Knockdown of miR-146a resulted in significantly higher histopathological scores for tubular damage, expression of proinflammatory cytokines and chemokines, and neutrophil and macrophage infiltration. Furthermore, knockdown of miR-146a greatly up-regulated the protein levels of IL-1 receptor-associated kinase (IRAK-1) and tumor-necrosis factor (TNF) receptor-associated factor 6 (TRAF6), which are known target genes of miR-146a, leading to activation of NF-κB. Finally, elevation of nuclear translocation of NF-κB p65/p50 and caspase-3 expression, degradation of cytosolic IkBα and BcL-xL, and substantially exacerbation of tubular cell apoptosis were inversely correlated with miR-146a expression. Taken together, our results identify that miR146a exerts a kidney protective effect through negative regulation of acute inflammatory response by suppressing NF-κB activation and proinflammatory genes expression. PMID:27250735

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    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.

  7. Cyanobacterial lipopolysaccharides and human health – a review

    PubMed Central

    Stewart, Ian; Schluter, Philip J; Shaw, Glen R

    2006-01-01

    Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation. PMID:16563160

  8. Garlic (Allium sativum) Extracts Inhibits Lipopolysaccharide-Induced Toll-Like Receptor 4 Dimerization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Garlic has been used as a folk medicine for a long history. Numerous studies demonstrated that garlic extracts and its sulfur-containing compounds inhibit nuclear factor-kappa B (NF-kB) activation induced by various receptor agonist including lipopolysaccharide (LPS). These effects suggest that garl...

  9. Molecular characterization and immune response to lipopolysaccharide (LPS) of the suppressor of cytokine signaling (SOCS)-1, 2 and 3 genes in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Cai-Zhi; He, An-Yuan; Chen, Li-Qiao; Limbu, Samwel Mchele; Wang, Ya-Wen; Zhang, Mei-Ling; Du, Zhen-Yu

    2016-03-01

    Suppressor of cytokine signaling (SOCS) proteins are inverse feedback regulators of cytokine and hormone signaling mediated by the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway that are involved in immunity, growth and development of organisms. In the present study, three SOCS genes, SOCS-1, SOCS-2 and SOCS-3, were identified in an economically important fish, Nile tilapia (Oreochromis niloticus) referred to as NtSOCS-1, NtSOCS-2 and NtSOCS-3. Multiple alignments showed that, the three SOCS molecules share highly conserved functional domains, including the SRC homology 2 (SH2) domain, the extended SH2 subdomain (ESS) and the SOCS box with others vertebrate counterparts. Phylogenetic analysis indicated that NtSOCS-1, 2 and 3 belong to the SOCS type II subfamily. Whereas NtSOCS-1 and 3 showed close evolutionary relationship with Perciformes, NtSOCS-2 was more related to Salmoniformes. Tissue specific expression results showed that, NtSOCS-1, 2 and 3 were constitutively expressed in all nine tissues examined. NtSOCS-1 and 3 were highly expressed in immune-related tissues, such as gills, foregut and head kidney. However, NtSOCS-2 was superlatively expressed in liver, brain and heart. In vivo, NtSOCS-1 and 3 mRNA levels were up-regulated after lipopolysaccharide (LPS) challenge while NtSOCS-2 was down-regulated. In vitro, LPS stimulation increased NtSOCS-3 mRNA expression, however it inhibited the transcription of NtSOCS-1 and 2. Collectively, our findings suggest that, the NtSOCS-1 and 3 might play significant role(s) in innate immune response, while NtSOCS-2 may be more involved in metabolic regulation. PMID:26820103

  10. Protective Role of Flavonoids and Lipophilic Compounds from Jatropha platyphylla on the Suppression of Lipopolysaccharide (LPS)-Induced Inflammation in Macrophage Cells.

    PubMed

    Ambriz-Pérez, Dulce L; Bang, Woo Young; Nair, Vimal; Angulo-Escalante, Miguel A; Cisneros-Zevallos, Luis; Heredia, J Basilio

    2016-03-01

    Seventeen polyphenols (e.g, apigenin, genistein, and luteolin glycosides) and 11 lipophilic compounds (e.g., fatty acids, sterols, and terpenes) were detected by LC-MS/MS-ESI and GC-MS, respectively, in Jatropha platyphylla. Extracts from pulp, kernel, and leaves and fractions were studied to know their effect on some pro-inflammatory mediators. Phenolic and lipophilic extracts showed significant inhibitory effects on ROS and NO production while not affecting mitochondrial activity or superoxide generation rate in lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells. In addition, NO production was also diminished by lipophilic leaf fractions F1 and F2 with the latter fraction showing a greater effect and composed mainly of sterols and terpene. Furthermore, total extracts showed nonselective inhibitions against cyclooxygenase COX-1 and COX-2 activities. All together, these results suggest that J. platyphylla extracts have potential in treating inflammatory diseases and their activity is mediated by flavonoids and lipophilic compounds. PMID:26872073

  11. Protective Role of Ternatin Anthocyanins and Quercetin Glycosides from Butterfly Pea (Clitoria ternatea Leguminosae) Blue Flower Petals against Lipopolysaccharide (LPS)-Induced Inflammation in Macrophage Cells.

    PubMed

    Nair, Vimal; Bang, Woo Young; Schreckinger, Elisa; Andarwulan, Nuri; Cisneros-Zevallos, Luis

    2015-07-22

    Twelve phenolic metabolites (nine ternatin anthocyanins and three glycosylated quercetins) were identified from the blue flowers of Clitoria ternatea by high-performance liquid chromatography diode array detection and electrospray ionization/mass spectrometry (HPLC-DAD-ESI/MS(n)). Three anthocyanins not reported in this species before show fragmentation pattern of the ternatin class. Extracts were fractionated in fractions containing flavonols (F3) and ternatin anthocyanins (F4). In general, C. ternatea polyphenols showed anti-inflammatory properties in lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells with distinct molecular targets. Flavonols (F3) showed strong inhibition of COX-2 activity and partial ROS suppression. On the other hand, the ternatin anthocyanins (F4) inhibited nuclear NF-κB translocation, iNOS protein expression, and NO production through a non-ROS suppression mechanism. Accordingly, quercetin glycosides and ternatin anthocyanins from the blue flower petals of C. ternatea may be useful in developing drugs or nutraceuticals for protection against chronic inflammatory diseases by suppressing the excessive production of pro-inflammatory mediators from macrophage cells. PMID:26120869

  12. Target deletion of complement component 9 attenuates antibody-mediated hemolysis and lipopolysaccharide (LPS)-induced acute shock in mice

    PubMed Central

    Fu, Xiaoyan; Ju, Jiyu; Lin, Zhijuan; Xiao, Weiling; Li, Xiaofang; Zhuang, Baoxiang; Zhang, Tingting; Ma, Xiaojun; Li, Xiangyu; Ma, Chao; Su, Weiliang; Wang, Yuqi; Qin, Xuebin; Liang, Shujuan

    2016-01-01

    Terminal complement membrane attack complex (MAC) formation is induced initially by C5b, followed by the sequential condensation of the C6, C7, C8. Polymerization of C9 to the C5b-8 complex forms the C5b-9 (or MAC). The C5b-9 forms lytic or non lytic pores in the cell membrane destroys membrane integrity. The biological functionalities of MAC has been previously investigated by using either the mice deficient in C5 and C6, or MAC’s regulator CD59. However, there is no available C9 deficient mice (mC9−/−) for directly dissecting the role of C5b-9 in the pathogenesis of human diseases. Further, since C5b-7 and C5b-8 complexes form non lytic pore, it may also plays biological functionality. To better understand the role of terminal complement cascades, here we report a successful generation of mC9−/−. We demonstrated that lack of C9 attenuates anti-erythrocyte antibody-mediated hemolysis or LPS-induced acute shock. Further, the rescuing effect on the acute shock correlates with the less release of IL-1β in mC9−/−, which is associated with suppression of MAC-mediated inflammasome activation in mC9−/−. Taken together, these results not only confirm the critical role of C5b-9 in complement-mediated hemolysis and but also highlight the critical role of C5b-9 in inflammasome activation. PMID:27444648

  13. Target deletion of complement component 9 attenuates antibody-mediated hemolysis and lipopolysaccharide (LPS)-induced acute shock in mice.

    PubMed

    Fu, Xiaoyan; Ju, Jiyu; Lin, Zhijuan; Xiao, Weiling; Li, Xiaofang; Zhuang, Baoxiang; Zhang, Tingting; Ma, Xiaojun; Li, Xiangyu; Ma, Chao; Su, Weiliang; Wang, Yuqi; Qin, Xuebin; Liang, Shujuan

    2016-01-01

    Terminal complement membrane attack complex (MAC) formation is induced initially by C5b, followed by the sequential condensation of the C6, C7, C8. Polymerization of C9 to the C5b-8 complex forms the C5b-9 (or MAC). The C5b-9 forms lytic or non lytic pores in the cell membrane destroys membrane integrity. The biological functionalities of MAC has been previously investigated by using either the mice deficient in C5 and C6, or MAC's regulator CD59. However, there is no available C9 deficient mice (mC9(-/-)) for directly dissecting the role of C5b-9 in the pathogenesis of human diseases. Further, since C5b-7 and C5b-8 complexes form non lytic pore, it may also plays biological functionality. To better understand the role of terminal complement cascades, here we report a successful generation of mC9(-/-). We demonstrated that lack of C9 attenuates anti-erythrocyte antibody-mediated hemolysis or LPS-induced acute shock. Further, the rescuing effect on the acute shock correlates with the less release of IL-1β in mC9(-/-), which is associated with suppression of MAC-mediated inflammasome activation in mC9(-/-). Taken together, these results not only confirm the critical role of C5b-9 in complement-mediated hemolysis and but also highlight the critical role of C5b-9 in inflammasome activation. PMID:27444648

  14. Immunomodulatory Effects of Yersinia pestis Lipopolysaccharides on Human Macrophages ▿

    PubMed Central

    Matsuura, Motohiro; Takahashi, Hideyuki; Watanabe, Haruo; Saito, Shinji; Kawahara, Kazuyoshi

    2010-01-01

    In the current study, we investigated the activity of lipopolysaccharide (LPS) purified from Yersinia pestis grown at either 27°C or 37°C (termed LPS-27 and LPS-37, respectively). LPS-27 containing hexa-acylated lipid A, similar to the LPS present in usual gram-negative bacteria, stimulated an inflammatory response in human U937 cells through Toll-like receptor 4 (TLR4). LPS-37, which did not contain hexa-acylated lipid A, exhibited strong antagonistic activity to the TLR4-mediated inflammatory response. The phagocytic activity in the cells was not affected by LPS-37. To estimate the activity of LPS in its bacterial binding form, formalin-killed bacteria (FKB) were prepared from Y. pestis cells grown at 27°C or 37°C (termed FKB-27 and FKB-37, respectively). FKB-27 strongly stimulated the inflammatory response. This activity was suppressed in the presence of an anti-TLR4 antibody but not an anti-TLR2 antibody. In addition, this activity was almost completely suppressed by LPS-37, indicating that the activity of FKB-27 is predominantly derived from the LPS-27 bacterial binding form. In contrast, FKB-37 showed no antagonistic activity. The results arising from the current study indicate that Y. pestis causes infection in humans without stimulating the TLR4-based defense system via bacterial binding of LPS-37, even when bacterial free LPS-37 is not released to suppress the defense system. This is in contrast to the findings for bacteria that possess agonistic LPS types, which are easily recognized by the defense system via the bacterial binding forms. PMID:19889939

  15. Flagellin and lipopolysaccharide up-regulation of IL-6 and CXCLi2 gene expression in chicken heterophils is mediated by NF-kappaB and AP-1 pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Toll-like receptor agonists, flagellin (FLG) and lipopolysaccharide (LPS) have been shown to stimulate chicken heterophils to induce the expression and secretion of pro-inflammatory cytokines by a mechanism involving the triggering of differential MEK-ERK signaling cascades. However, the transl...

  16. Peroxisome proliferator-activated receptor-delta agonist ameliorated inflammasome activation in nonalcoholic fatty liver disease

    PubMed Central

    Lee, Hyun Jung; Yeon, Jong Eun; Ko, Eun Jung; Yoon, Eileen L; Suh, Sang Jun; Kang, Keunhee; Kim, Hae Rim; Kang, Seoung Hee; Yoo, Yang Jae; Je, Jihye; Lee, Beom Jae; Kim, Ji Hoon; Seo, Yeon Seok; Yim, Hyung Joon; Byun, Kwan Soo

    2015-01-01

    AIM: To evaluate the inflammasome activation and the effect of peroxisome proliferator-activated receptors (PPAR)-δ agonist treatment in nonalcoholic fatty liver disease (NAFLD) models. METHODS: Male C57BL/6J mice were classified according to control or high fat diet (HFD) with or without PPAR-δ agonist (GW) over period of 12 wk [control, HFD, HFD + lipopolysaccharide (LPS), HFD + LPS + GW group]. HepG2 cells were exposed to palmitic acid (PA) and/or LPS in the absence or presence of GW. RESULTS: HFD caused glucose intolerance and hepatic steatosis. In mice fed an HFD with LPS, caspase-1 and interleukin (IL)-1β in the liver were significantly increased. Treatment with GW ameliorated the steatosis and inhibited overexpression of pro-inflammatory cytokines. In HepG2 cells, PA and LPS treatment markedly increased mRNA of several nucleotide-binding and oligomerization domain-like receptor family members (NLRP3, NLRP6, and NLRP10), caspase-1 and IL-1β. PA and LPS also exaggerated reactive oxygen species production. All of the above effects of PA and LPS were reduced by GW. GW also enhanced the phosphorylation of AMPK-α. CONCLUSION: PPAR-δ agonist reduces fatty acid-induced inflammation and steatosis by suppressing inflammasome activation. Targeting the inflammasome by the PPAR-δ agonist may have therapeutic implication for NAFLD. PMID:26668503

  17. 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.

    PubMed

    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. PMID:25637446

  18. Chemoattractant-induced release of elastase by lipopolysaccharide (LPS)-primed neutrophils; inhibitory effect of the anti-inflammatory drug nimesulide.

    PubMed

    Ottonello, L; Barbera, P; Dapino, P; Sacchetti, C; Dallegri, F

    1997-10-01

    Human neutrophils, pre-exposed to low concentrations (1-10 ng/ml) of bacterial LPS in the presence of 1% autologous serum, released elastase activity in response to N-formyl-met-leu-phe (fMLP). Both cell incubation with LPS without subsequent fMLP stimulus and fMLP stimulation without prior exposure to LPS failed to promote significant elastase release. Therefore, LPS primes neutrophils for the subsequent release of elastase in response to fMLP. Compared with fMLP, human recombinant C5a had a slight although not significant activity, whereas other chemoattractants such as IL-8, platelet-activating factor and leukotriene B4 were ineffective. The fMLP-induced response of LPS-primed neutrophils was susceptible to suppression by the methane-sulphonanilide anti-inflammatory drug nimesulide and RO 20-1724, which selectively inhibit cAMP-catabolizing phosphodiesterase type IV. This suggests that the elastase release by LPS-primed neutrophils is likely to be controlled by intracellular cAMP, and raises the possibility of limiting pharmacologically the elastase-mediated tissue injury during neutrophilic inflammation. PMID:9353161

  19. Chemoattractant-induced release of elastase by lipopolysaccharide (LPS)-primed neutrophils; inhibitory effect of the anti-inflammatory drug nimesulide

    PubMed Central

    OTTONELLO, L; BARBERA, P; DAPINO, P; SACCHETTI, C; DALLEGRI, F

    1997-01-01

    Human neutrophils, pre-exposed to low concentrations (1–10 ng/ml) of bacterial LPS in the presence of 1% autologous serum, released elastase activity in response to n-formyl-met-leu-phe (fMLP). Both cell incubation with LPS without subsequent fMLP stimulus and fMLP stimulation without prior exposure to LPS failed to promote significant elastase release. Therefore, LPS primes neutrophils for the subsequent release of elastase in response to fMLP. Compared with fMLP, human recombinant C5a had a slight although not significant activity, whereas other chemoattractants such as IL-8, platelet-activating factor and leukotriene B4 were ineffective. The fMLP-induced response of LPS-primed neutrophils was susceptible to suppression by the methane-sulphonanilide anti-inflammatory drug nimesulide and RO 20-1724, which selectively inhibit cAMP-catabolizing phosphodiesterase type IV. This suggests that the elastase release by LPS-primed neutrophils is likely to be controlled by intracellular cAMP, and raises the possibility of limiting pharmacologically the elastase-mediated tissue injury during neutrophilic inflammation. PMID:9353161

  20. Flagellin and lipopolysaccharide up-regulation of IL-6 and CXCLi2 gene expression in chicken heterophils is mediated by ERK1/2-dependent activation of AP-1 and NF-kappaB signaling pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Toll-like receptor agonists, flagellin (FLG) and lipopolysaccharide (LPS), stimulate chicken heterophils to induce the expression and secretion of pro-inflammatory cytokines by a mechanism involving the triggering of differential MEK-ERK signaling cascades. However, the translocation and activa...

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

    SciTech Connect

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

    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.

  2. 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

    PubMed Central

    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

  3. Counteracting Interactions between Lipopolysaccharide Molecules with Differential Activation of Toll-Like Receptors

    PubMed Central

    Hajishengallis, George; Martin, Michael; Schifferle, Robert E.; Genco, Robert J.

    2002-01-01

    We investigated counteracting interactions between the lipopolysaccharides (LPS) from Escherichia coli (Ec-LPS) and Porphyromonas gingivalis (Pg-LPS), which induce cellular activation through Toll-like receptor 4 (TLR4) and TLR2, respectively. We found that Ec-LPS induced tolerance in THP-1 cells to subsequent tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) induction by Pg-LPS, though the reverse was not true, and looked for explanatory differential effects on the signal transduction pathway. Cells exposed to Pg-LPS, but not to Ec-LPS, displayed persisting expression of IL-1 receptor-associated kinase without apparent degradation, presumably allowing prolonged relay of downstream signals. Accordingly, cells pretreated with Pg-LPS, but not with Ec-LPS, were effectively activated in response to subsequent exposure to either LPS molecule, as evidenced by assessing nuclear factor (NF)-κB activity. In fact, Pg-LPS primed THP-1 cells for enhanced NF-κB activation and TNF-α release upon restimulation with the same LPS. This was a dose-dependent effect and correlated with upregulation of surface TLR2 expression. Furthermore, we observed inhibition of NF-κB-dependent transcription in a reporter cell line pretreated with Ec-LPS and restimulated with Pg-LPS (compared to cells pretreated with medium only and restimulated with Pg-LPS), but not when the reverse treatment was made. Although Pg-LPS could not make cells tolerant to subsequent activation by Ec-LPS, Pg-LPS inhibited Ec-LPS-induced TNF-α and IL-6 release when the two molecules were added simultaneously into THP-1 cell cultures. Pg-LPS also suppressed P. gingivalis FimA protein-induced NF-κB-dependent transcription in the 3E10/huTLR4 reporter cell line, which does not express TLR2. This rules out competition for common signaling intermediates, suggesting that Pg-LPS may block component(s) of the TLR4 receptor complex. Interactions between TLR2 and TLR4 agonists may be important in the

  4. Soluble CD14 Enhances the Response of Periodontal Ligament Stem Cells to P. gingivalis Lipopolysaccharide

    PubMed Central

    Andrukhov, Oleh; Andrukhova, Olena; Özdemir, Burcu; Haririan, Hady; Müller-Kern, Michael; Moritz, Andreas; Rausch-Fan, Xiaohui

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) are lacking membrane CD14, which is an important component of lipopolysaccharide (LPS) signaling through toll-like receptor (TLR) 4. In the present study we investigated the effect of soluble CD14 on the response of human PDLSCs to LPS of Porphyromonas (P.) gingivalis. Human PDLSCs (hPDLSCs) were stimulated with P. gingivalis LPS in the presence or in the absence of soluble CD14 (sCD14) and the production of interleukin (IL)-6, chemokine C-X-C motif ligand 8 (CXCL8), and chemokine C-C motif ligand 2 (CCL2) was measured. The response to P. gingivalis LPS was compared with that to TLR4 agonist Escherichia coli LPS and TLR2-agonist Pam3CSK4. The response of hPDLSCs to both P. gingivalis LPS and E. coli LPS was significantly enhanced by sCD14. In the absence of sCD14, no significant difference in the hPDLSCs response to two kinds of LPS was observed. These responses were significantly lower compared to that to Pam3CSK4. In the presence of sCD14, the response of hPdLSCs to P. gingivalis LPS was markedly higher than that to E. coli LPS and comparable with that to Pam3CSK4. The response of hPdLSCs to bacterial LPS is strongly augmented by sCD14. Local levels of sCD14 could be an important factor for modulation of the host response against periodontal pathogens. PMID:27504628

  5. Structure and Bioactivity of a Modified Peptide Derived from the LPS-Binding Domain of an Anti-Lipopolysaccharide Factor (ALF) of Shrimp.

    PubMed

    Yang, Hui; Li, Shihao; Li, Fuhua; Xiang, Jianhai

    2016-05-01

    The lipopolysaccharide binding domain (LBD) in anti-lipopolysaccharide factor (ALF) is the main functional element of ALF, which exhibits antimicrobial activities. Our previous studies show that the peptide LBDv, synthesized based on the modified sequence of LBD (named LBD2) from FcALF2, exhibited an apparently enhanced antimicrobial activity. To learn the prospect of LBDv application, the characteristics of LBDv were analyzed in the present study. The LBDv peptide showed higher antimicrobial and bactericidal activities compared with LBD2. These activities of the LBDv peptide were stable after heat treatment. LBDv could also exhibit in vivo antimicrobial activity to Vibrio harveyi. The LBDv peptide was found to bind bacteria, quickly cause bacterial agglutination, and kill bacteria by damaging their membrane integrity. Structure analysis showed that both LBDv and LBD2 held the β-sheet structure, and the positive net charge and amphipathicity characteristic were speculated as two important components for their antimicrobial activity. The cytotoxicity of LBDv was evaluated in cultured Spodoptera frugiperda (Sf9) cells and Cherax quadricarinatus hemocytes. More than 80% cells could survive with the LBDv concentration up to 16 μM. Collectively, these findings highlighted the potential antimicrobial mechanism of LBD peptides, and provided important information for the commercial use of LBDv in the future. PMID:27213409

  6. Structure and Bioactivity of a Modified Peptide Derived from the LPS-Binding Domain of an Anti-Lipopolysaccharide Factor (ALF) of Shrimp

    PubMed Central

    Yang, Hui; Li, Shihao; Li, Fuhua; Xiang, Jianhai

    2016-01-01

    The lipopolysaccharide binding domain (LBD) in anti-lipopolysaccharide factor (ALF) is the main functional element of ALF, which exhibits antimicrobial activities. Our previous studies show that the peptide LBDv, synthesized based on the modified sequence of LBD (named LBD2) from FcALF2, exhibited an apparently enhanced antimicrobial activity. To learn the prospect of LBDv application, the characteristics of LBDv were analyzed in the present study. The LBDv peptide showed higher antimicrobial and bactericidal activities compared with LBD2. These activities of the LBDv peptide were stable after heat treatment. LBDv could also exhibit in vivo antimicrobial activity to Vibrio harveyi. The LBDv peptide was found to bind bacteria, quickly cause bacterial agglutination, and kill bacteria by damaging their membrane integrity. Structure analysis showed that both LBDv and LBD2 held the β-sheet structure, and the positive net charge and amphipathicity characteristic were speculated as two important components for their antimicrobial activity. The cytotoxicity of LBDv was evaluated in cultured Spodoptera frugiperda (Sf9) cells and Cherax quadricarinatus hemocytes. More than 80% cells could survive with the LBDv concentration up to 16 μM. Collectively, these findings highlighted the potential antimicrobial mechanism of LBD peptides, and provided important information for the commercial use of LBDv in the future. PMID:27213409

  7. Terlipressin inhibits in vivo aortic iNOS expression induced by lipopolysaccharide in rats with biliary cirrhosis.

    PubMed

    Moreau, Richard; Barrière, Eric; Tazi, Khalid A; Lardeux, Bernard; Dargère, Delphine; Urbanowicz, Waldemar; Poirel, Odile; Chauvelot-Moachon, Laurence; Guimont, Marie-Christine; Bernuau, Dominique; Lebrec, Didier

    2002-11-01

    In cirrhosis, lipopolysaccharide (LPS, a product of Gram-negative bacteria) in the blood may cause septic shock. LPS-elicited induction of arterial inducible nitric oxide synthase (iNOS) results in nitric oxide (NO)-induced vasodilation, which causes arterial hypotension and hyporeactivity to alpha(1)-adrenergic constrictors. In vitro studies have suggested that vasopressin inhibits iNOS expression in cultured vascular smooth muscle cells exposed to LPS. Thus, the aim of this study was to investigate the effects of terlipressin administration (a vasopressin analog) on in vivo LPS-induced aortic iNOS in rats with cirrhosis. LPS (1 mg/kg, intravenously) was administered followed by the intravenous administration of terlipressin (0.05 mg/kg, intravenously) or placebo 1 hour later. Arterial pressure was measured, and contractions to phenylephrine (an alpha(1)-adrenoceptor agonist), iNOS activity, and iNOS expressions (mRNA and protein) were investigated in isolated aortas. LPS-induced arterial hypotension and aortic hyporeactivity to phenylephrine were abolished in rats that received terlipressin. LPS-induced aortic iNOS activity and expression were suppressed in terlipressin-treated rats. In conclusion, in LPS-challenged rats with cirrhosis, terlipressin administration inhibits in vivo LPS-induced aortic iNOS expression. Terlipressin administration may be a novel approach for the treatment of arterial hypotension and hyporeactivity to alpha(1)-adrenergic constrictors in patients with cirrhosis and septic shock. PMID:12395316

  8. Flagellin or lipopolysaccharide treatment modified macrophage populations after colorectal radiation of rats.

    PubMed

    Lacavé-Lapalun, Jean-Victor; Benderitter, Marc; Linard, Christine

    2013-07-01

    Radiation-induced acute intestinal toxicity remains a major limitation to the delivery of tumoricidal doses of colorectal irradiation. Recent reports indicate that Toll-like receptor (TLR) agonists TLR4 and TLR5 protect against toxicity due to intestinal irradiation. The phenotype (M1 or M2) of macrophages expressing TLRs may play a role in tissue repair. The aim was to investigate whether administration of TLR4 agonist lipopolysaccharide (LPS) or TLR5 agonist flagellin after irradiation modified the recruitment and phenotype of colonic macrophages and improved tissue damage. Rats were exposed to single 20- or 27-Gy doses of colorectal irradiation. TLR4 agonist LPS or TLR5 agonist flagellin (at 50 or 200 µg/rat) was administered i.p. 3 days after irradiation. Flow cytometric analysis, immunostaining, and real-time polymerase chain reaction analysis were used to assess the M1/M2 phenotype and crypt cell proliferation 7 days after irradiation. Irradiation (20 and 27 Gy) increased TLR4⁺ and TLR5⁺ macrophage frequency in the mucosa. LPS or flagellin administration maintained this elevated frequency after the 27-Gy irradiation. LPS and flagellin drove macrophages toward the anti-inflammatory M2 phenotype by increasing Arg1 and CD163 expression and microenvironmental effector molecules (C-C motif chemokine 22, transforming growth factor-β1, and interleukin-10). Proliferating cell nuclear antigen immunostaining, Ki67 expression, and antimicrobial factor Reg3γ showed that the M2 shift correlated with epithelial regeneration. In conclusion, administration of either LPS or flagellin after colorectal irradiation may provide effective protection against epithelial remodeling. This tissue repair was associated with an M2 macrophage shift. Using TLR agonists to moderately activate innate immunity should be considered as a strategy for protecting healthy tissue from irradiation. PMID:23596059

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

    PubMed

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

    2016-02-01

    The adenine nucleotide translocases (ANTs) play a vital role in energy metabolism via ADP/ATP exchange in eukaryotic cells. Apostichopus japonicus (Echinodermata: Holothuroidea) is an important economic species in China. Here, a cDNA representing an ANT gene of A. japonicus was isolated and characterized from respiratory tree and named AjANT. The full-length AjANT cDNA is 1924 bp, including a 5'-untranslated region (UTR) of 38 bp, 3'-UTR of 980 bp and an open reading frame (ORF) of 906 bp encoding a polypeptide of 301 amino acids. The protein contains three homologous repeat Mito_carr domains (Pfam00153). The deduced AjANT protein sequence has 49-81% in comparison to ANT proteins from other individuals. The predicted tertiary structure of AjANT protein is highly similar to animal ANT proteins. Phylogenetic analysis showed that the AjANT is closely related to Holothuroidea ANT genes. Real-time quantitative reverse transcription-PCR (qPCR) analysis showed that AjANT expression is higher in the respiratory tree than in other examined tissues. After thermal stress or LPS challenge, expression of AjANT was significantly fluctuant compared to the control. These results suggested that changes in the expression of ANT gene might be involved in immune defense and in protecting A. japonicus against thermal stress. PMID:26706223

  10. Structure-activity relationships of lipopolysaccharide (LPS) in tumor necrosis factor-alpha (TNF-alpha) production and induction of macrophage cell death in the presence of cycloheximide (CHX) in a murine macrophage-like cell line, J774.1.

    PubMed

    Karahashi, H; Amano, F

    1998-10-01

    The structure-activity relationships of lipopolysaccharide (LPS) in tumor necrosis factor-alpha (TNF-alpha) production and induction of macrophage cell death in the presence of cycloheximide (CHX) were examined in a murine macrophage-like cell line, J774.1. TNF-alpha production is one of the characteristic phenotypes of LPS-activated macrophages, and is observed upon incubation with LPS. On the contrary, macrophage cell death, which had been found in our laboratory (Amano F., Karahashi H., J. Endotoxin Res., 3, 415423 (1996)) and was examined as the release of lactate dehydrogenase (LDH) from cells into the culture supernatant, was observed 2.5 h after the addition of LPS in the presence of CHX. However, both TNF-alpha production and macrophage cell death were similarly dependent on the structures of LPS and lipid A. At more than 10 ng/ml, wild-type LPS from E.coli and S. minnesota exhibited the highest activity, and LPS as well as diphosphoryl lipid A from S. minnesota rough mutants also exhibited activity, but E. coli LPS detoxified by alkaline treatment or monophosphoryl lipid A from S. minnesota exhibited no activity even at 100 ng/ml. These results suggest that LPS-induced macrophage cell death in the presence of CHX shows similar requirements for LPS and/or lipid A structures as for the macrophage activation at higher doses than 10 ng/ml, although the former was not observed at 1 ng/ml LPS, while the latter was. However, TNF-alpha does not seem to be involved in the induction of macrophage cell death, because a neutralizing anti-TNF-alpha antibody failed to block the macrophage cell death and because recombinant TNF-alpha had little effect on the extent of LDH release in the presence or absence of LPS and/or CHX, and also because TNF-alpha production by LPS was abolished in the presence of CHX. PMID:9821819

  11. Lipopolysaccharide recognition, CD14, and lipopolysaccharide receptors.

    PubMed

    Ingalls, R R; Heine, H; Lien, E; Yoshimura, A; Golenbock, D

    1999-06-01

    The ability of a host to sense invasion by a pathogenic organism, and to respond appropriately to control infection, is paramount to survival. To that end, an array of receptors and binding proteins has evolved as part of the innate immune system to detect Gram-negative bacteria. This article reviews the role of CD14, other LPS binding proteins, and the Toll family of receptors in the innate recognition of bacterial lipopolysaccharide. PMID:10340170

  12. [Characterization of Budvicia aquatica lipopolysaccharides].

    PubMed

    Varbanets', L D; Brovars'ka, O S; Pokhil, S Y

    2011-01-01

    For the first time lipopolysaccharides (LPS) of 6 Budvicia aquatica strains--representatives of new Enterobacteriaceae species have been isolated. It was shown that the yield of LPS ranged from 0.9 to 7.0 % of cells dry weight. On the basis of monosaccharide composition LPS of tested strains may be referred to 3 groups. The serological studies indicated the immunochemical heterogeneity of B. aquatica species: LPS interacted only in homological system and showed no cross-reactivity with heterological antisera. PMID:21809684

  13. Lipopolysaccharide induces macrophage migration via prostaglandin D(2) and prostaglandin E(2).

    PubMed

    Tajima, Tsuyoshi; Murata, Takahisa; Aritake, Kosuke; Urade, Yoshihiro; Hirai, Hiroyuki; Nakamura, Masataka; Ozaki, Hiroshi; Hori, Masatoshi

    2008-08-01

    Lipopolysaccharide (LPS) produces prostaglandins (PGs) concomitant to eliciting macrophage migration. We evaluated the role of PGs in initiating the migration of macrophages, especially focusing on PGD(2) and PGE(2). In RAW264.7 macrophages, cyclooxygenase (COX)-2 inhibitor, CAY10404 [3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole], completely inhibited LPS-mediated migration at 4 h (early phase) but only partially inhibited the migration at 8 h (late phase), suggesting the presence of PG-dependent and -independent pathways. In the early phase, LPS up-regulated mRNA expressions of COX-2, hematopoietic PGD synthase (H-PGDS), and microsomal-PGE synthase 1, increasing PGD(2) and PGE(2) substantially. The chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes (CRTH2) agonist, DK-PGD(2) (13-14-dihydro-15-keto-PGD(2)), and the EP4 agonist, ONO-AE1-329 (16-{3-methoxymethyl}phenyl-omega-tetranor-3,7-dithia-prostaglandin E(1)), but not selective agonists of D prostanoid receptor, E prostanoid receptor (EP) 2, or EP3, stimulated random migration (chemokinesis). In peritoneal macrophages from CRTH2-deficient and H-PGDS-deficient mice, LPS-mediated migration was significantly inhibited at either early or late phases of the migration. The H-PGDS inhibitor, HQL-79 [4-(diphenylmethoxy)-1-[3-(1H-tetrazol-5-yl)propyl-piperidine

  14. Influence of Brucella abortus lipopolysaccharide as an adjuvant on the immunogenicity of HPV-16 L1VLP vaccine in mice.

    PubMed

    Kianmehr, Zahra; Soleimanjahi, Hoorieh; Ardestani, Susan Kaboudanian; Fotouhi, Fatemeh; Abdoli, Asghar

    2015-04-01

    Brucella abortus lipopolysaccharide (LPS) has less toxicity and no pyrogenic properties in comparison with other bacterial LPS. It is a toll-like receptor 4 agonist and has been shown to have the potential use as a vaccine adjuvant. In this study, the immunostimulatory properties of LPS from smooth and rough strains of B. abortus (S19 and RB51) as adjuvants were investigated for the human papillomavirus type 16 (HPV16) L1 virus-like particles (L1VLPs) vaccines. C57BL/6 mice were immunized subcutaneously three times either with HPV-16 L1VLPs alone, or in combination with smooth LPS (S-LPS), rough LPS (R-LPS), aluminum hydroxide or a mixture of them as adjuvant. The humoral immunity was evaluated by measuring the specific and total IgG levels, and also the T-cell immune response of mice was evaluated by measuring different cytokines such as IFN-γ, TNF-α, IL-4, IL-10 and IL-17. Results showed that serum anti-HPV16 L1VLP IgG antibody titers was significantly higher in mice immunized with a combination of VLPs and R-LPS or S-LPS compared with other immunized groups. Co-administration of HPV-16 L1VLPs with R-LPS elicited the highest levels of splenocytes cytokines (IFN-γ, IL-4, IL-17 and TNF-α) and also effectively induced improvement of a Th1-type cytokine response characterized with a high ratio of IFN-γ/IL-10. The data indicate that B. abortus LPS particularly RB51-LPS enhances the immune responses to HPV-16 L1VLPs and suggests its potential as an adjuvant for the development of a potent prophylactic HPV vaccine and other candidate vaccines. PMID:25187406

  15. ENDOTHELIAL CELL TOLERANCE TO LIPOPOLYSACCHARIDE CHALLENGE IS INDUCED BY MONOPHOSPHORYL LIPID A

    PubMed Central

    Stark, Ryan J.; Choi, Hyehun; Koch, Stephen R.; Fensterheim, Benjamin A.; Lamb, Fred S.; Sherwood, Edward R.

    2015-01-01

    Prior exposure to lipopolysaccharide (LPS) produces a reduced or “tolerant” inflammatory response to subsequent challenges with LPS, however the potent pro-inflammatory effects of LPS limit its clinical benefit. The adjuvant Monophosphoryl lipid A (MPLA) is a weak toll-like receptor 4 (TLR4) agonist that induces negligible inflammation but retains potent immunomodulatory properties. We postulated that pre-treatment with MPLA would inhibit the inflammatory response of endothelial cells to secondary LPS challenge. Human umbilical vein endothelial cells (HUVECs), were exposed to MPLA (10 µg/ml), LPS (100 ng/ml) or vehicle control. HUVECs were then washed and maintained in culture for 24 hours before being challenged with LPS (100 ng/ml). Supernatants were collected and examined for cytokine production in the presence or absence of siRNA inhibitors of critical TLR4 signaling proteins. Pretreatment with MPLA attenuated IL-6 production to secondary LPS challenge to a similar degree as LPS. The application of MyD88 siRNA dramatically reduced MPLA-induced tolerance while TRIF siRNA had no effect. The tolerant phenotype in endothelial cells was associated with reduced IKK, p38 and JNK phosphorylation and enhanced IRAK-M expression for LPS primed HUVECs, but less so in MPLA primed cells. Instead, MPLA-primed HUVECs demonstrated enhanced ERK phosphorylation. In contrast to leukocytes in which tolerance is largely TRIF-dependent, MyD88 signaling mediated endotoxin tolerance in endothelial cells. Most importantly, MPLA, a vaccine adjuvant with a wide therapeutic window, induced tolerance to LPS in endothelial cells. PMID:26669797

  16. Endothelial cell tolerance to lipopolysaccharide challenge is induced by monophosphoryl lipid A.

    PubMed

    Stark, Ryan J; Choi, Hyehun; Koch, Stephen R; Fensterheim, Benjamin A; Lamb, Fred S; Sherwood, Edward R

    2016-03-01

    Prior exposure to lipopolysaccharide (LPS) produces a reduced or "tolerant" inflammatory response to subsequent challenges with LPS, however the potent pro-inflammatory effects of LPS limit its clinical benefit. The adjuvant monophosphoryl lipid A (MPLA) is a weak toll-like receptor 4 (TLR4) agonist that induces negligible inflammation but retains potent immunomodulatory properties. We postulated that pre-treatment with MPLA would inhibit the inflammatory response of endothelial cells to secondary LPS challenge. Human umbilical vein endothelial cells (HUVECs), were exposed to MPLA (10 μg/ml), LPS (100 ng/ml) or vehicle control. HUVECs were then washed and maintained in culture for 24 h before being challenged with LPS (100 ng/ml). Supernatants were collected and examined for cytokine production in the presence or absence of siRNA inhibitors of critical TLR4 signalling proteins. Pre-treatment with MPLA attenuated interleukin (IL)-6 production to secondary LPS challenge to a similar degree as LPS. The application of myeloid differentiation primary response gene 88 (MyD88) siRNA dramatically reduced MPLA-induced tolerance while TIR-domain-containing adapter-inducing interferon-β (TRIF) siRNA had no effect. The tolerant phenotype in endothelial cells was associated with reduced IκB kinase (IKK), p38 and c-Jun N-terminal kinase (JNK) phosphorylation and enhanced IL-1 receptor associated kinase-M (IRAK-M) expression for LPS-primed HUVECs, but less so in MPLA primed cells. Instead, MPLA-primed HUVECs demonstrated enhanced p-extracellular-signal-regulated kinase (ERK) phosphorylation. In contrast with leucocytes in which tolerance is largely TRIF-dependent, MyD88 signalling mediated endotoxin tolerance in endothelial cells. Most importantly, MPLA, a vaccine adjuvant with a wide therapeutic window, induced tolerance to LPS in endothelial cells. PMID:26669797

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

    SciTech Connect

    Zhang, Ying; Li, Jianguo

    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.

  18. Inhibition of IRAK-4 activity for rescuing endotoxin LPS-induced septic mortality in mice by lonicerae flos extract

    SciTech Connect

    Park, Sun Hong; Roh, Eunmiri; Kim, Hyun Soo; Baek, Seung-Il; Choi, Nam Song; Kim, Narae; Hwang, Bang Yeon; Han, Sang-Bae; Kim, Youngsoo

    2013-12-13

    Highlights: •Lonicerae flos extract (HS-23) is a clinical candidate, Phase I for sepsis treatment. •Here, HS-23 or its major constituents rescued LPS-induced septic mortality in mice. •As a mechanism, they directly inhibited IRAK-4-catalyzed kinase activity. •Thus, they suppressed LPS-induced expression of NF-κB/AP-1-target inflammatory genes. -- Abstract: Lonicerae flos extract (HS-23) is a clinical candidate currently undergoing Phase I trial in lipopolysaccharide (LPS)-injected healthy human volunteers, but its molecular basis remains to be defined. Here, we investigated protective effects of HS-23 or its major constituents on Escherichia coli LPS-induced septic mortality in mice. Intravenous treatment with HS-23 rescued LPS-intoxicated C57BL/6J mice under septic conditions, and decreased the levels of cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β and high-mobility group box-1 (HMGB-1) in the blood. Chlorogenic acid (CGA) and its isomers were assigned as major constituents of HS-23 in the protection against endotoxemia. As a molecular mechanism, HS-23 or CGA isomers inhibited endotoxin LPS-induced autophosphorylation of the IL-1 receptor-associated kinase 4 (IRAK-4) in mouse peritoneal macrophages as well as the kinase activity of IRAK-4 in cell-free reactions. HS-23 consequently suppressed downstream pathways critical for LPS-induced activation of nuclear factor (NF)-κB or activating protein 1 (AP-1) in the peritoneal macrophages. HS-23 also inhibited various toll-like receptor agonists-induced nitric oxide (NO) production, and down-regulated LPS-induced expression of NF-κB/AP-1-target inflammatory genes in the cells. Taken together, HS-23 or CGA isomers exhibited anti-inflammatory therapy against LPS-induced septic mortality in mice, at least in part, mediated through the inhibition of IRAK-4.

  19. Induction of murine adenosine A(2A) receptor expression by LPS: analysis of the 5' upstream promoter.

    PubMed

    Elson, G; Eisenberg, M; Garg, C; Outram, S; Ferrante, C J; Hasko, G; Leibovich, S J

    2013-04-01

    Non-activated macrophages express low levels of A(2A)Rs and lipopolysaccharides (LPS) upregulates A(2A)R expression in an NF-κB-dependent manner. The murine A(2A)R gene is encoded by three exons, m1, m2 and m3. Exons m2 and m3 are conserved, while m1 encodes the 5' untranslated UTR. Three m1 variants have been defined, m1A, m1B and m1C, with m1C being farthest from the transcriptional start site. LPS upregulates A(2A)Rs in primary murine peritoneal and bone-marrow-derived macrophages and RAW264.7 cells by selectively splicing m1C to m2, through a promoter located upstream of m1C. We have cloned ∼1.6 kb upstream of m1C into pGL4.16(luc2CP/Hygro) promoterless vector. This construct in RAW 264.7 cells responds to LPS, and adenosine receptor agonists augmented LPS responsiveness. The NF-κB inhibitors BAY-11 and triptolide inhibited LPS-dependent induction. Deletion of a key proximal NF-κB site (402-417) abrogated LPS responsiveness, while deletion of distal NF-κB and C/EBPβ sites did not. Site-directed mutagenesis of CREB (309-320), STAT1 (526-531) and AP2 (566-569) sites had little effect on LPS and adenosine receptor agonist responsiveness; however, mutation of a second STAT1 site (582-588) abrogated this responsiveness. Further analysis of this promoter should provide valuable insights into regulation of A(2A)R expression in macrophages in response to inflammatory stimuli. PMID:23328845

  20. A protease-activated receptor 2 agonist (AC-264613) suppresses interferon regulatory factor 5 and decreases interleukin-12p40 production by lipopolysaccharide-stimulated macrophages: Role of p53.

    PubMed

    Yamaguchi, Rui; Yamamoto, Takatoshi; Sakamoto, Arisa; Ishimaru, Yasuji; Narahara, Shinji; Sugiuchi, Hiroyuki; Yamaguchi, Yasuo

    2016-06-01

    The transcription factor interferon regulatory factor 5 (IRF5) has a key role in the production of interleukin (IL)-12 by macrophages. IRF5 is also a central mediator of toll-like receptor signaling and is a direct target of p53. Activation of protease-activated receptor 2 (PAR-2) upregulates p53 and suppresses apoptosis. This study investigated the influence of human neutrophil elastase (HNE) and PAR-2 agonists on expression of IRF5 and IL-12p40 by macrophages stimulated with lipopolysaccharide. Granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent macrophages showed upregulation of IRF5 expression, while HNE reduced expression of p53 and IRF5 in a concentration-dependent manner. HNE also caused a concentration-dependent decrease of IRF5 in macrophages transfected with small interfering RNA to silence p53, while silencing of β-arrestin 2 blunted the reduction of p53 or IRF5 by HNE. Incubation of macrophages with a PAR-2 agonist, AC-264613, caused a decrease of IRF5 expression and also significantly reduced p53 protein expression. HNE upregulated the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6) and caused transactivation of TLR4, while AC-264613 did not promote TLR4 transactivation. In conclusion, the PAR-2 agonist AC-264613 attenuated IRF5-associated IL-12p40 production by macrophages. PMID:26833899

  1. Exendin-4 Protected against Cognitive Dysfunction in Hyperglycemic Mice Receiving an Intrahippocampal Lipopolysaccharide Injection

    PubMed Central

    Liang, Keng-Chen; Jheng, Yu-Syuan; Jhao, Jhih-Jhen; Su, Ming-Tsan; Lee-Chen, Guey-Jen; Hsieh-Li, Hsiu Mei

    2012-01-01

    Background Chronic hyperglycemia-associated inflammation plays critical roles in disease initiation and the progression of diabetic complications, including Alzheimer’s disease (AD). However, the association of chronic hyperglycemia with acute inflammation of the central nervous system in the progression of AD still needs to be elucidated. In addition, recent evidence suggests that Glucagon-like peptide-1 receptor (GLP-1R) protects against neuronal damage in the brain. Therefore, the neuroprotective effects of the GLP-1R agonist exendin-4 (EX-4) against hyperglycemia/lipopolysaccharides (LPS) damage were also evaluated in this study. Methodology/Principal Findings Ten days after streptozotocin (STZ) or vehicle (sodium citrate) treatment in mice, EX-4 treatment (10 µg/kg/day) was applied to the mice before intrahippocampal CA1 injection of LPS or vehicle (saline) and continued for 28 days. This study examined the molecular alterations in these mice after LPS and EX4 application, respectively. The mouse cognitive function was evaluated during the last 6 days of EX-4 treatment. The results showed that the activation of NF-κB-related inflammatory responses induced cognitive dysfunction in both the hyperglycemic mice and the mice that received acute intrahippocampal LPS injection. Furthermore, acute intrahippocampal LPS injection exacerbated the impairment of spatial learning and memory through a strong decrease in monoaminergic neurons and increases in astrocytes activation and apoptosis in the hyperglycemic mice. However, EX-4 treatment protected against the cognitive dysfunction resulting from hyperglycemia or/and intrahippocampal LPS injection. Conclusions/Significance These findings reveal that both hyperglycemia and intrahippocampal LPS injection induced cognitive dysfunction via activation of NF-κB-related inflammatory responses. However, acute intrahippocampal LPS injection exacerbated the progression of cognitive dysfunction in the hyperglycemic mice via a

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

    SciTech Connect

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

    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.

  3. Activation of α2 adrenoceptor attenuates lipopolysaccharide-induced hepatic injury

    PubMed Central

    Chen, Jing-Hui; Yu, Gao-Feng; Jin, Shang-Yi; Zhang, Wen-Hua; Lei, Dong-Xu; Zhou, Shao-Li; Song, Xing-Rong

    2015-01-01

    Sepsis induces hepatic injury but whether alpha-2 adrenoceptor (α2-AR) modulates the severity of sepsis-induced liver damage remains unclear. The present study used lipopolysaccharide (LPS) to induce hepatic injury and applied α2-AR agonist dexmedetomidine (DEX) and/or antagonist yohimbine to investigate the contribution of α2-AR in LPS-induced liver injury. Our results showed that LPS resulted in histological and functional abnormality of liver tissue (ALT and AST transaminases, lactate), higher mortality, an increase in proinflammatory cytokines (IL-1β, IL-6 & TNF-α), as well as a change in oxidative stress (MDA, SOD). Activation of α2-AR by dexmedetomidine (DEX) attenuated LPS-induced deleterious effects on the liver and block of α2-AR by yohimbine aggravated LPS-induced liver damage. Our data suggest that α2-AR plays an important role in sepsis-induced liver damage and activation of α2-AR with DEX could be a novel therapeutic avenue to protect the liver against sepsis-induced injury. PMID:26617786

  4. Fenoterol inhibits LPS-induced AMPK activation and inflammatory cytokine production through β-arrestin-2 in THP-1 cell line

    SciTech Connect

    Wang, Wei; Zhang, Yuan; Xu, Ming; Zhang, You-Yi; He, Bei

    2015-06-26

    The AMP-activated protein kinase (AMPK) pathway is involved in regulating inflammation in several cell lines. We reported that fenoterol, a β{sub 2}-adrenergic receptor (β{sub 2}-AR) agonist, had anti-inflammatory effects in THP-1 cells, a monocytic cell line. Whether the fenoterol anti-inflammatory effect involves the AMPK pathway is unknown. In this study, we explored the mechanism of β{sub 2}-AR stimulation with fenoterol in a lipopolysaccharide (LPS)-induced inflammatory cytokine secretion in THP-1 cells. We studied whether fenoterol and β-arrestin-2 or AMPKα1 subunit knockdown could affect LPS-induced AMPK activation, nuclear factor-kappa B (NF-κB) activation and inflammatory cytokine secretion. LPS-induced AMPK activation and interleukin 1β (IL-1β) release were reduced with fenoterol pretreatment of THP-1 cells. SiRNA knockdown of β-arrestin-2 abolished the fenoterol inhibition of LPS-induced AMPK activation and interleukin 1β (IL-1β) release, thus β-arrestin-2 mediated the anti-inflammatory effects of fenoterol on LPS-treated THP-1 cells. In addition, siRNA knockdown of AMPKα1 significantly attenuated the LPS-induced NF-κB activation and IL-1β release, so AMPKα1 was a key signaling molecule involved in LPS-induced inflammatory cytokine production. These results suggested the β{sub 2}-AR agonist fenoterol inhibited LPS-induced AMPK activation and IL-1β release via β-arrestin-2 in THP-1 cells. The exploration of these mechanisms may help optimize therapeutic agents targeting these pathways in inflammatory diseases. - Highlights: • β{sub 2}-AR agonist fenoterol exerts its protective effect on LPS-treated THP-1 cells. • Fenoterol inhibits LPS-induced AMPK activation and IL-1β production. • β-arrestin2 mediates fenoterol-inhibited AMPK activation and IL-1β release. • AMPKα1 is involved in LPS-induced NF-κB activation and IL-1β production.

  5. Administration of the inverse benzodiazepine agonist MRK-016 rescues acquisition and memory consolidation following peripheral administration of bacterial endotoxin.

    PubMed

    Eimerbrink, M J; White, J D; Pendry, R J; Hodges, S L; Sadler, L N; Wiles, J D; Weintraub, M K; Chumley, M J; Boehm, G W

    2015-07-15

    Recent evidence suggests that inflammation-induced decrements in cognitive function can be mitigated via manipulation of excitatory or inhibitory transmission. We tested the ability of the inverse benzodiazepine agonist, MRK-016 (MRK) to protect against LPS-induced deficits in memory acquisition and consolidation, using a contextual fear conditioning (CFC) paradigm. In Experiment One, mice received lipopolysaccharide (LPS) and/or MRK injections prior to CFC training, and were then tested 24h after training. In Experiment Two, animals received similar treatment injections immediately after training, and were tested 24h later. Additionally, hippocampal samples were collected 4h after LPS injections and immediately after testing, to evaluate brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) mRNA expression. Results indicate that MRK can protect against LPS-induced learning/memory decrements in both paradigms. We also found, in both paradigms, that animals treated with LPS/Saline expressed significantly less BDNF mRNA when compared to Saline/Saline-treated animals 4h after LPS administration, but that MRK did not restore BDNF expression levels. Further, treatment administrations had no effect on IGF-1 mRNA expression at any collection time-point. In summary, MRK-016 can protect against LPS-induced deficits in memory acquisition and consolidation, in this hippocampus-dependent paradigm, though this protection occurs independently of recovery of BDNF expression. PMID:25823763

  6. Inflammatory caspases are innate immune receptors for intracellular LPS.

    PubMed

    Shi, Jianjin; Zhao, Yue; Wang, Yupeng; Gao, Wenqing; Ding, Jingjin; Li, Peng; Hu, Liyan; Shao, Feng

    2014-10-01

    The murine caspase-11 non-canonical inflammasome responds to various bacterial infections. Caspase-11 activation-induced pyroptosis, in response to cytoplasmic lipopolysaccharide (LPS), is critical for endotoxic shock in mice. The mechanism underlying cytosolic LPS sensing and the responsible pattern recognition receptor are unknown. Here we show that human monocytes, epithelial cells and keratinocytes undergo necrosis upon cytoplasmic delivery of LPS. LPS-induced cytotoxicity was mediated by human caspase-4 that could functionally complement murine caspase-11. Human caspase-4 and the mouse homologue caspase-11 (hereafter referred to as caspase-4/11) and also human caspase-5, directly bound to LPS and lipid A with high specificity and affinity. LPS associated with endogenous caspase-11 in pyroptotic cells. Insect-cell purified caspase-4/11 underwent oligomerization upon LPS binding, resulting in activation of the caspases. Underacylated lipid IVa and lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS) could bind to caspase-4/11 but failed to induce their oligomerization and activation. LPS binding was mediated by the CARD domain of the caspase. Binding-deficient CARD-domain point mutants did not respond to LPS with oligomerization or activation and failed to induce pyroptosis upon LPS electroporation or bacterial infections. The function of caspase-4/5/11 represents a new mode of pattern recognition in immunity and also an unprecedented means of caspase activation. PMID:25119034

  7. Non-typhoidal Salmonella encephalopathy involving lipopolysaccharide in cattle.

    PubMed

    Xiong, N; Brewer, M T; Anderson, K L; Carlson, S A

    2013-02-22

    This study assessed the involvement of lipopolysaccharide (LPS) in the non-typhoidal Salmonella encephalopathy (NTSE) caused by a unique isolate of Salmonella enterica serovar Saint-paul (SstpNPG). NTSE was prevented by genetic (deletion of murE) or pharmacologic (polymyxin) disruption of LPS on SstpNPG although the disruption of LPS did not deter brain penetration of the strain. This is the first study to demonstrate that LPS is involved in the manifestations of NTSE. PMID:22939987

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

    PubMed Central

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

    1989-01-01

    The tissue distribution of Klebsiella pneumoniae O3 lipopolysaccharide (KO3 LPS) was studied in mice injected subcutaneously (s.c.) or intraperitoneally (i.p.) with 125I-labeled KO3 LPS. Marked retention of KO3 LPS radioactivity could be found at the site of s.c. injection for several weeks. On the other hand, about 85% of the radioactivity rapidly disappeared from the peritoneal cavity within 6 h after i.p. injection. The long-term presence of KO3 LPS at the injection site was also supported by experiments with 51Cr-labeled KO3 LPS and immunoblotting and immunofluorescence staining methods. The R-form LPS lacking the O-specific polysaccharide chain of KO3 LPS and the lipid A fraction of KO3 LPS seemed to remain at the site in larger amounts and for longer times than KO3 LPS. There were no marked differences in the retention pattern at the injection site among KO3 LPS, Escherichia coli LPS, Salmonella typhosa LPS, and Salmonella enteritidis LPS. However, much less radioactivity accumulated in the livers and spleens of mice injected with either KO3 LPS or S. typhosa LPS compared with the other LPS preparations. It was suggested that retention of LPS at the site of s.c. injection may play an important role in the development of various biological actions of s.c. injected LPS. Images PMID:2722239

  9. BML-111 Protected LPS/D-GalN-Induced Acute Liver Injury in Rats

    PubMed Central

    Yan, Dan; Liu, Hai-Ling; Yu, Zhong-Jian; Huang, Yong-Hong; Gao, Dian; Hao, Hua; Liao, Shou-Sheng; Xu, Fang-Yun; Zhou, Xiao-Yan

    2016-01-01

    Lipoxins (LXs) display unique pro-resolving and anti-inflammatory functions in a variety of inflammatory conditions. The present study was undertaken to investigate the effects of BML-111 (5(S),6(R),7-trihydroxyheptanoic acid methyl ester), the agonist of lipoxin A4 receptor, in a model of Lipopolysaccharides (LPS) and d-Galactosamine (d-GalN) induced acute liver injury, and to explore the mechanisms. Histopathological analyses were carried out to quantify liver injury degree. The activities of myeloperoxidase (MPO) were examined to evaluate the levels of neutrophil infiltration. The activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum were detected to evaluate the functions of the liver. The amounts of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and interleukin-1β (IL-1β) were measured using enzyme-linked immunosorbent assay (ELISA), and the expression levels of transforming growth factor-β1(TGF-β1) and cyclooxygenase-2 (COX-2) were examined using Western blotting. The antioxidant capacity, the activities of inducible nitric oxide synthase (iNOS), the contents of malondialdehyde (MDA) and nitric oxide (NO) were analyzed with the kits via biochemical analysis. We established the model of acute liver injury with lipopolysaccharide and d-Galactosamine (LPS/d-GalN): (1) histopathological results and MPO activities, with the activities of AST and ALT in serum, consistently demonstrated LPS and d-GalN challenge could cause severe liver damage, but BML-111 could prevent pathological changes, inhibit neutrophil infiltration, and improve the hepatic function; (2) LPS/d-GalN increased TNF-α, IL-1β, COX-2, and IL-10, while decreasing TGF-β1. However, BML-111 could repress LPS/d-GalN -induced TNF-α, IL-1β and COX-2, meanwhile increasing the expression levels of TGF-β1 and IL-10; (3) LPS/d-GalN inhibited the activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and hydroxyl

  10. BML-111 Protected LPS/D-GalN-Induced Acute Liver Injury in Rats.

    PubMed

    Yan, Dan; Liu, Hai-Ling; Yu, Zhong-Jian; Huang, Yong-Hong; Gao, Dian; Hao, Hua; Liao, Shou-Sheng; Xu, Fang-Yun; Zhou, Xiao-Yan

    2016-01-01

    Lipoxins (LXs) display unique pro-resolving and anti-inflammatory functions in a variety of inflammatory conditions. The present study was undertaken to investigate the effects of BML-111 (5(S),6(R),7-trihydroxyheptanoic acid methyl ester), the agonist of lipoxin A₄ receptor, in a model of Lipopolysaccharides (LPS) and d-Galactosamine (d-GalN) induced acute liver injury, and to explore the mechanisms. Histopathological analyses were carried out to quantify liver injury degree. The activities of myeloperoxidase (MPO) were examined to evaluate the levels of neutrophil infiltration. The activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum were detected to evaluate the functions of the liver. The amounts of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and interleukin-1β (IL-1β) were measured using enzyme-linked immunosorbent assay (ELISA), and the expression levels of transforming growth factor-β1(TGF-β1) and cyclooxygenase-2 (COX-2) were examined using Western blotting. The antioxidant capacity, the activities of inducible nitric oxide synthase (iNOS), the contents of malondialdehyde (MDA) and nitric oxide (NO) were analyzed with the kits via biochemical analysis. We established the model of acute liver injury with lipopolysaccharide and d-Galactosamine (LPS/d-GalN): (1) histopathological results and MPO activities, with the activities of AST and ALT in serum, consistently demonstrated LPS and d-GalN challenge could cause severe liver damage, but BML-111 could prevent pathological changes, inhibit neutrophil infiltration, and improve the hepatic function; (2) LPS/d-GalN increased TNF-α, IL-1β, COX-2, and IL-10, while decreasing TGF-β1. However, BML-111 could repress LPS/d-GalN -induced TNF-α, IL-1β and COX-2, meanwhile increasing the expression levels of TGF-β1 and IL-10; (3) LPS/d-GalN inhibited the activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and hydroxyl

  11. Role of UCP2 in the protective effects of PPARβ/δ activation on lipopolysaccharide-induced endothelial dysfunction.

    PubMed

    Toral, Marta; Romero, Miguel; Jiménez, Rosario; Robles-Vera, Iñaki; Tamargo, Juan; Martínez, María Carmen; Pérez-Vizcaíno, Francisco; Duarte, Juan

    2016-06-15

    Bacterial endotoxin lipopolysaccharide (LPS) activates inflammatory pathways, induces cytokine expression in the endothelium, augments reactive oxygen species (ROS) production in the vascular wall, and induces endothelial dysfunction. The aim of the present study was to analyze the effects of peroxisome proliferator-activated receptor (PPAR)β/δ activation on LPS-induced inflammation, oxidative stress and endothelial dysfunction and to determine whether uncoupling protein-2 (UCP2) plays a role in these effects. In vivo, the PPARβ/δ agonist GW0742 treatment prevented the LPS-induced reduction in aortic relaxation, the increase in vascular ROS production, the upregulation of NOX1, NOX2, p47(phox), and p22(phox) mRNA levels, and the endoplasmic reticulum (ER) stress markers in mice. We show that in mouse aortic endothelial cells (MAECs), GW0742 prevented the decreased A23187-stimulated nitric oxide (NO) production, and the increased intracellular ROS levels caused by exposure to LPS in vitro. The PPARβ/δ antagonist GSK0660 abolished all these in vivo and in vitro protective effects induced by GW0742. This agonist also restored the reduced expression of UCP2 and mitofusin-2 induced by LPS. The effects of GW0742 on NO and ROS production in MAEC exposed to LPS were abolished by the UCP2 inhibitor genipin or by siRNA targeting UCP-2. Genipin also suppressed the expressional changes on NADPH oxidase and ER stress markers induced by GW0742. In conclusion, PPARβ/δ activation restored the LPS-induced endothelial dysfunction by upregulation of UCP2, with the subsequent alleviation of ER stress and NADPH oxidase activity, thus reducing intracellular ROS production and increasing NO bioavailability. PMID:27179975

  12. Quercetin and its principal metabolites, but not myricetin, oppose lipopolysaccharide-induced hyporesponsiveness of the porcine isolated coronary artery

    PubMed Central

    Al-Shalmani, Salmin; Suri, Sunita; Hughes, David A; Kroon, Paul A; Needs, Paul W; Taylor, Moira A; Tribolo, Sandra; Wilson, Vincent G

    2011-01-01

    BACKGROUND AND PURPOSE Quercetin is anti-inflammatory in macrophages by inhibiting lipopolysaccharide (LPS)-mediated increases in cytokine and nitric oxide production but there is little information regarding the corresponding effect on the vasculature. We have examined the effect of quercetin, and its principal human metabolites, on inflammatory changes in the porcine isolated coronary artery. EXPERIMENTAL APPROACH Porcine coronary artery segments were incubated overnight at 37°C in modified Krebs-Henseleit solution with or without 1 µg·mL−1 LPS. Some segments were also co-incubated with quercetin-related flavonoids or Bay 11-7082, an inhibitor of NFκB. Changes in isometric tension of segments to vasoconstrictor and vasodilator agents were recorded. Nitrite content of the incubation solution was estimated using the Griess reaction, while inducible nitric oxide synthase was identified immunohistochemically. KEY RESULTS Lipopolysaccharide reduced, by 35–50%, maximal contractions to KCl and U46619, thromboxane A2 receptor agonist, and impaired endothelium-dependent relaxations to substance P. Nitrite content of the incubation medium increased 3- to 10-fold following exposure to LPS and inducible nitric oxide synthase was detected in the adventitia. Quercetin (0.1–10 µM) opposed LPS-induced changes in vascular responses, nitrite production and expression of inducible nitric oxide synthase. Similarly, 10 µM Bay 11-7082, 10 µM quercetin 3′-sulphate and 10 µM quercetin 3-glucuronide prevented LPS-induced changes, while myricetin (10 µM) was inactive. Myricetin (10 µM) prevented quercetin-induced modulation of LPS-mediated nitrite production. CONCLUSION AND IMPLICATIONS Quercetin, quercetin 3′-suphate and quercetin 3-glucuronide, exerted anti-inflammatory effects on the vasculature, possibly through a mechanism involving inhibition of NFκB. Myricetin-induced antagonism of the effect of anti-inflammatory action of quercetin merits further investigation

  13. Social management of LPS-induced inflammation in Formica polyctena ants.

    PubMed

    Aubert, A; Richard, F-J

    2008-08-01

    Invertebrates, and especially insects, constitute valuable and convenient models for the study of the evolutionary roots of immune-related behaviors. With stable conditions in the nest, high population densities, and frequent interactions, social insects such as ants provide an excellent system for examining the spread of pathogens. The evolutionary success of these species raises questions about the behavioral responses of social insects to an infected nestmate. In this experiment, we tested the behavioral changes of the red wood ant Formica polyctena toward an immune-stimulated nestmate. We used bacterial endotoxin (lipopolysaccharides, LPS) to active the innate immune system of individual worker ants without biasing our observation with possible cues or host-manipulation from a living pathogen. We show that LPS-induced immune activation in ants triggers behavioral changes in nestmates. Contrary to what would be expected, we did not find removal strategies (e.g. agonistic behaviors) or avoidance of the pathogenic source, but rather a balance between a limitation of pathogen dissemination (i.e. decreased trophallaxis and locomotion of the LPS-treated ant), and what could constitute the behavioral basis for a "social vaccination" (i.e. increased grooming). This supports the importance of social interactions in resistance to disease in social insects, and perhaps social animals in general. PMID:18331785

  14. Oxidized low density lipoprotein suppresses lipopolysaccharide-induced inflammatory responses in microglia: Oxidative stress acts through control of inflammation

    SciTech Connect

    Kim, Ohn Soon; Lee, Chang Seok; Joe, Eun-hye; Jou, Ilo . E-mail: jouilo@ajou.ac.kr

    2006-03-31

    Low density lipoprotein (LDL) is readily oxidized under certain conditions, resulting in the formation of oxidized LDL (oxLDL). Despite numerous in vitro reports that reveal the pathogenic role of oxidative stress, anti-oxidative strategies have underperformed in the clinic. In this study, we examine the role of oxLDL in brain inflammatory responses using cultured rat brain microglia. We demonstrate that oxLDL inhibits lipopolysaccharide (LPS)-induced inflammatory responses in these cells. It also decreases LPS-induced expression of inducible nitric oxide synthase and production of nitric oxide, and reduces LPS-induced secretion of tumor necrosis factor-{alpha} and monocyte chemoattractant protein-1. Oxysterols, known components of oxLDL and endogenous agonists of liver X receptor, can simulate the inhibitory effects of oxLDL in LPS-activated microglia. In addition, their inhibitory effects were mimicked by liver X receptor (LXR) agonists and potentiated by a retinoid X receptor agonist, suggesting these molecules heterodimerize to function as oxysterol receptors. Taken together, our results demonstrate that oxLDL inhibits LPS-induced inflammatory responses in brain microglia and that these inhibitory effects are mediated by oxysterols and, at least in part, by the nuclear receptor LXR. Our results suggest an additional mechanism of action for oxidative stress that acts indirectly via modulation of inflammatory responses. Although further studies are needed, these results answer in part the question of why anti-oxidative strategies have not been successful in clinical situations. Moreover, as brain inflammation participates in the initiation and progression of several neurodegenerative disorders, the present data provide information that should prove a useful guide for designing therapeutic strategies to combat oxidative brain diseases.

  15. Structure and Function of Lipopolysaccharide Binding Protein

    NASA Astrophysics Data System (ADS)

    Schumann, Ralf R.; Leong, Steven R.; Flaggs, Gail W.; Gray, Patrick W.; Wright, Samuel D.; Mathison, John C.; Tobias, Peter S.; Ulevitch, Richard J.

    1990-09-01

    The primary structure of lipopolysaccharide binding protein (LBP), a trace plasma protein that binds to the lipid A moiety of bacterial lipopolysaccharides (LPSs), was deduced by sequencing cloned complementary DNA. LBP shares sequence identity with another LPS binding protein found in granulocytes, bactericidal/permeability-increasing protein, and with cholesterol ester transport protein of the plasma. LBP may control the response to LPS under physiologic conditions by forming high-affinity complexes with LPS that bind to monocytes and macrophages, which then secrete tumor necrosis factor. The identification of this pathway for LPS-induced monocyte stimulation may aid in the development of treatments for diseases in which Gram-negative sepsis or endotoxemia are involved.

  16. ABCA1 promotes the efflux of bacterial LPS from macrophages and accelerates recovery from LPS-induced tolerance[S

    PubMed Central

    Thompson, Patricia A.; Gauthier, Karine C.; Varley, Alan W.; Kitchens, Richard L.

    2010-01-01

    Macrophages play important roles in both lipid metabolism and innate immunity. We show here that macrophage ATP-binding cassette transporter A1 (ABCA1), a transporter known for its ability to promote apolipoprotein-dependent cholesterol efflux, also participates in the removal of an immunostimulatory bacterial lipid, lipopolysaccharide (LPS). Whereas monocytes require an exogenous lipoprotein acceptor to remove cell-associated LPS, macrophages released LPS in the absence of an exogenous acceptor by a mechanism that was driven, in part, by endogenous apolipoprotein E (apoE). Agents that increased ABCA1 expression increased LPS efflux from wild-type but not ABCA1-deficient macrophages. Preexposure of peritoneal macrophages to LPS for 24 h increased the expression of ABCA1 and increased LPS efflux with a requirement for exogenous apolipoproteins due to suppression of endogenous apoE production. In contrast, LPS preconditioning of ABCA1-deficient macrophages significantly decreased LPS efflux and led to prolonged retention of cell-surface LPS. Although the initial response to LPS was similar in wild-type and ABCA1-deficient macrophages, LPS-induced tolerance was greater and more prolonged in macrophages that lacked ABCA1. Our results define a new role for macrophage ABCA1 in removing cell-associated LPS and restoring normal macrophage responsiveness. PMID:20472936

  17. Critical residues involved in Toll-like receptor 4 activation by cationic lipid nanocarriers are not located at the lipopolysaccharide-binding interface.

    PubMed

    Lonez, Caroline; Irvine, Kate L; Pizzuto, Malvina; Schmidt, Boris I; Gay, Nick J; Ruysschaert, Jean-Marie; Gangloff, Monique; Bryant, Clare E

    2015-10-01

    DiC14-amidine is a cationic lipid that was originally designed as a lipid nanocarrier for nucleic acid transport, and turned out to be a Toll-like receptor 4 (TLR4) agonist as well. We found that while E. coli lipopolysaccharide (LPS) is a TLR4 agonist in all species, diC14-amidine nanoliposomes are full agonists for human, mouse and cat receptors but weak horse agonists. Taking advantage of this unusual species specificity, we used chimeric constructs based on the human and horse sequences and identified two regions in the human TLR4 that modulate the agonist activity of diC14-amidine. Interestingly, these regions lie outside the known LPS-binding domain. Competition experiments also support our hypothesis that diC14-amidine interacts primarily with TLR4 hydrophobic crevices located at the edges of the TLR4/TLR4* dimerization interface. We have characterized potential binding modes using molecular docking analysis and suggest that diC14-amidine nanoliposomes activate TLR4 by facilitating its dimerization in a process that is myeloid differentiation 2 (MD-2)-dependent and cluster of differentiation 14 (CD14)-independent. Our data suggest that TLR4 may be activated through binding at different anchoring points, expanding the repertoire of TLR4 ligands to non-MD-2-binding lipids. PMID:25956320

  18. Physical properties of defined lipopolysaccharide salts

    SciTech Connect

    Coughlin, R.T.; Haug, A.; McGroarty, E.J.

    1983-01-01

    The electron spin resonance probes 5-doxylstearate and 4-(dodecyldimethylammonia)-1-oxy-2,2,6,6-tetramethylpiperidine bromide were used to characterize the fluidity of the acyl chain and head-group regions, respectively, of defined salts of lipopolysaccharide (LPS) from Escherichia coli K12. The removal of the weakly bound divalent cations from native LPS by electrodialysis and their replacement by sodium had little effect on the midpoint of the lipid-phase transition or on head-group mobility. In contrast, lipopolysaccharide acyl chain mobility increased following electrodialysis. The replacement of most of the remaining cations with sodium resulted in a further dramatic increase in mobility in both the polar and nonpolar regions of lipopolysaccharide. Head-group mobility of the sodium salt of LPS was shown to be reduced with the addition of divalent cations. Furthermore, evidence is presented which suggests that low magnesium concentrations may induce phase separations in the sodium salt. The magnesium salt of lipopolysaccharide closely resembled the native form in both head-group and acyl chain mobility although the cation charge to phosphorus ratio in the magnesium salt was greater than that detected in the native isolate. Analyses of other lipopolysaccharide salts support our hypothesis that many of the observed differences in the physical and pathological properties of lipopolysaccharide salts may simply be explained by the degree of charge neutralization.

  19. Physical properties of defined lipopolysaccharide salts.

    PubMed

    Coughlin, R T; Haug, A; McGroarty, E J

    1983-04-12

    The electron spin resonance probes 5-doxylstearate and 4-(dodecyldimethylammonio)-1-oxy-2,2,6,6-tetramethylpiperidine bromide were used to characterize the fluidity of the acyl chain and head-group regions, respectively, of defined salts of lipopolysaccharide (LPS) from Escherichia coli K12. The removal of the weakly bound divalent cations from native LPS by electrodialysis and their replacement by sodium had little effect on the midpoint of the lipid-phase transition or on head-group mobility. In contrast, lipopolysaccharide acyl chain mobility increased following electrodialysis. The replacement of most of the remaining cations with sodium resulted in a further dramatic increase in mobility in both the polar and nonpolar regions of lipopolysaccharide. Head-group mobility of the sodium salt of LPS was shown to be reduced with the addition of divalent cations. Furthermore, evidence is presented which suggests that low magnesium concentrations may induce phase separations in the sodium salt. The magnesium salt of lipopolysaccharide closely resembled the native form in both head-group and acyl chain mobility although the cation charge to phosphorus ratio in the magnesium salt was greater than that detected in the native isolate. Analyses of other lipopolysaccharide salts support our hypothesis that many of the observed differences in the physical and pathological properties of lipopolysaccharide salts may simply be explained by the degree of charge neutralization. PMID:6303400

  20. 5-HT2A receptors control body temperature in mice during LPS-induced inflammation via regulation of NO production.

    PubMed

    Voronova, Irina P; Khramova, Galina M; Kulikova, Elizabeth A; Petrovskii, Dmitrii V; Bazovkina, Daria V; Kulikov, Alexander V

    2016-01-01

    G protein-coupled 5-HT2A receptors are involved in the regulation of numerous normal and pathological physiological functions. At the same time, its involvement in the regulation of body temperature (Tb) in normal conditions is obscure. Here we study the effect of the 5-HT2A receptor activation or blockade on Tb in sick animals. The experiments were carried out on adult C57BL/6 mouse males. Systemic inflammation and sickness were produced by lipopolysaccharide (LPS, 0.1mg/kg, ip), while the 5-HT2A receptor was stimulated or blocked through the administration of the receptor agonist DOI or antagonist ketanserin (1mg/kg), respectively. LPS, DOI or ketanserin alone produced no effect on Tb. However, administration of LPS together with a peripheral or central ketanserin injection reduced Tb (32.2°C). Ketanserin reversed the LPS-induced expression of inducible NO synthase in the brain. Consequently, an involvement of NO in the mechanism of the hypothermic effect of ketanserin in sick mice was hypothesized. Administration of LPS together with NO synthase inhibitor, l-nitro-arginine methyl ester (60mg/kg, ip) resulted in deep (28.5°C) and prolonged (8h) hypothermia, while administration of l-nitro-arginine methyl ester alone produced no effect on Tb. Thus, 5-HT2A receptors play a key role in Tb control in sick mice. Blockade of this GPCR produces hypothermia in mice with systemic inflammation via attenuation of LPS-induced NO production. These results indicate an unexpected role of 5-HT2A receptors in inflammation and NO production and have a considerable biological impact on understanding the mechanism of animal adaptation to pathogens and parasites. Moreover, adverse side effects of 5-HT2A receptor antagonists in patients with inflammation may be expected. PMID:26621247

  1. Synthetic LPS-Binding Polymer Nanoparticles

    NASA Astrophysics Data System (ADS)

    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

  2. Lipopolysaccharide Engineering in Neisseria meningitidis

    PubMed Central

    Pupo, Elder; Hamstra, Hendrik-Jan; Meiring, Hugo; van der Ley, Peter

    2014-01-01

    Engineering the lipopolysaccharide (LPS) biosynthetic pathway offers the potential to obtain modified derivatives with optimized adjuvant properties. Neisseria meningitidis strain H44/76 was modified by expression of the pagL gene encoding lipid A 3-O-deacylase from Bordetella bronchiseptica and by inactivation of the lgtB gene encoding the terminal oligosaccharide galactosyltransferase. Mass spectrometry analysis of purified mutant LPS was used for detailed compositional analysis of all present molecular species. This determined that the modified LPS was mainly pentaacylated, demonstrating high efficiency of conversion from the hexaacyl to the 3-O-deacylated form by heterologous lipid A 3-O-deacylase (PagL) expression. MS analyses also provided evidence for expression of only one major oligosaccharide glycoform, which lacked the terminal galactose residue as expected from inactivation of the lgtB gene. The immunomodulatory properties of PagL-deacylated LPS were compared with another pentaacyl form obtained from an lpxL1− mutant, which lacks the 2′ secondary acyl chain. Although both LPS mutants displayed impaired capacity to induce production of the pro-inflammatory cytokine IL-6 in the monocytic cell line Mono Mac 6, induction of the Toll-interleukin-1 receptor domain-containing adaptor-inducing interferon-β-dependent chemokine interferon-γ-induced protein 10 was largely retained only for the lgtB−/pagL+ mutant. Removal of remaining hexaacyl species exclusively present in lgtB−/pagL+ LPS demonstrated that these minor species potentiate but do not determine the activity of this LPS. These results are the first to indicate a qualitatively different response of human innate cells to pentaacyl lpxL1− and pagL+ LPS and show the importance of detailed structure-function analysis when working with modified lipid A structures. The pagL+ LPS has significant potential as immune modulator in humans. PMID:24492609

  3. Proteomic changes in chicken plasma induced by Salmonella typhimurium lipopolysaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipopolysaccharides (LPS) are cell wall components of gram-negative bacteria that cause inflammation and sickness through genetic and proteomic activation. The objective of our study was to identify the proteomic changes in plasma associated with inflammation induced by LPS treatment. Five-week-old ...

  4. Proteomic analysis of macrophage activated with salmonella lipopolysaccharide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macrophages play pivotal role in immunity. They are activated by many pathogen derived molecules such as lipopolysaccharides (LPS) which trigger the production of various proteins and peptides that drive and resolve inflammation. There are numerous studies on the effect of LPS at the genome level bu...

  5. [Phytotoxic properties of Ralstonia solanacearum lipopolysaccharides].

    PubMed

    Hrytsaĭ, R V; Iakovleva, L M; Varbanets', L D

    2014-01-01

    The study is dedicated to research of phytotoxic properties of Ralstonia solanacearum lipopolysaccharides. This causative agent is one of the most dangerous among potato bacterial diseases. It is revealed that the inhibitory effect of LPS solution on seedlings germination is more noticeable on crops susceptible to brown rot. Maximal total phytotoxic properties have been shown by LPS from strains 35, 52b, TX1 and TS3, which were characterized by relatively low rhamnose content. Relative to the control plants LPS may diminish and some ones--increase the root length, height and weight of seedlings, subject to particular strain. But the stimulation revealed is minor. PMID:25000727

  6. Role of the NOD1/NF-κB pathway on bovine neutrophil responses to crude lipopolysaccharide.

    PubMed

    Wei, Liang-Jun; Tan, Xun; Fan, Guo-Juan; Jiang, Ya-Nan; Shah, Qurban A

    2016-08-01

    Cytosolic nucleotide oligomerisation domain (NOD)-like receptors play an important role in host defence against infection. Reduced NOD1 expression has been observed in dysfunctional neutrophils derived from periparturient cattle known to be most susceptible to coliform mastitis. However, whether impairment of NOD1 suppresses the immune responses of bovine neutrophils during bacterial infections remains unknown. Crude (phenol extracted) lipopolysaccharide (cLPS), which often contains other immunostimulatory molecules, including NOD1 agonist, is known to induce almost the whole bacterial response. This study was conducted to explore the role of NOD1/nuclear factor (NF)-κB pathway in the cytokine and functional responses of bovine neutrophils challenged with Escherichia coli-derived cLPS. Freshly isolated blood neutrophils from healthy heifers were pre-incubated for 2 h with ML130, a selective inhibitor of NOD1/NF-κB pathway. Cells were then exposed to cLPS for additional 4 h. Inhibition of the NOD1/NF-κB pathway resulted in a decrease in cLPS-induced phosphorylation of the inhibitor of NF-κBα (IκBα) in neutrophils. Impairment of the NOD1/NF-κB pathway tended to down-regulate mRNA levels of pro-inflammatory cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α, chemokines IL-8 and C-X-C motif ligand 2 (CXCL2), and adhesion molecules CD11b and CD62L, in cLPS-challenged cells. Functional analyses showed that blocking the NOD1/NF-κB pathway inhibited neutrophil migration and phagocytic killing capacity, and promoted neutrophil death upon cLPS stimulation. The data presented here demonstrate that activation of NOD1/NF-κB pathway contributes to the functional responses of neutrophils to cLPS. PMID:27387722

  7. Neuroprotective Activity of (-)-Epigallocatechin Gallate against Lipopolysaccharide-Mediated Cytotoxicity.

    PubMed

    Liu, Jin-Biao; Zhou, Li; Wang, Yi-Zhong; Wang, Xu; Zhou, Yu; Ho, Wen-Zhe; Li, Jie-Liang

    2016-01-01

    Lipopolysaccharide- (LPS-) mediated systemic inflammation plays a critical role in neurodegenerative diseases. The present study was conducted to evaluate the protective effects of epigallocatechin gallate (EGCG), the major component in green tea, on LPS-mediated inflammation and neurotoxicity. LPS treatment of macrophages induced expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). However, EGCG pretreatment of macrophages significantly inhibited LPS-mediated induction of these cytokines. In addition, EGCG significantly diminished LPS-induced inflammatory cytokines in the peripheral mononuclear blood cells (PBMCs). Supernatant from EGCG-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-EGCG-pretreated and LPS-activated macrophage cultures. Furthermore, EGCG treatment of neurons could inhibit LPS-induced production of reactive oxygen species (ROS). Thus EGCG represents a potent and useful neuroprotective agent for inflammation-mediated neurological disorders. PMID:27191001

  8. Sulforaphane inhibits the engagement of LPS with TLR4/MD2 complex by preferential binding to Cys133 in MD2.

    PubMed

    Koo, Jung Eun; Park, Zee-Yong; Kim, Nam Doo; Lee, Joo Young

    2013-05-10

    Toll-like receptors (TLRs) are key pattern-recognition receptors that recognize invading pathogens and non-microbial endogenous molecules to induce innate and adaptive immune responses. Since activation of TLRs is deeply implicated in the pathological progress of autoimmune diseases, sepsis, metabolic diseases, and cancer, modulation of TLR activity is considered one of the most important therapeutic approaches. Lipopolysaccharide (LPS), an endotoxin of gram-negative bacteria, is a well-known agonist for TLR4 triggering inflammation and septic shock. LPS interacts with TLR4 through binding to a hydrophobic pocket in myeloid differentiation 2 (MD2), a co-receptor of TLR4. In this study, we showed that sulforaphane (SFN) interfered with the binding of LPS to MD2 as determined by in vitro binding assay and co-immunoprecipitation of MD2 and LPS in a cell system. The inhibitory effect of SFN on the interaction of LPS and MD2 was reversed by thiol supplementation with N-acetyl-L-cysteine or dithiothreitol showing that the inhibitory effect of SFN is dependent on its thiol-modifying activity. Indeed, micro LC-MS/MS analysis showed that SFN preferentially formed adducts with Cys133 in the hydrophobic pocket of MD2, but not with Cys95 and Cys105. Molecular modeling showed that SFN bound to Cys133 blocks the engagement of LPS and lipid IVa to hydrophobic pocket of MD2. Our results demonstrate that SFN interrupts LPS engagement to TLR4/MD2 complex by direct binding to Cys133 in MD2. Our data suggest a novel mechanism for the anti-inflammatory activity of SFN, and provide a novel target for the regulation of TLR4-mediated inflammatory and immune responses by phytochemicals. PMID:23583403

  9. Epigenetic Alterations Induced by Bacterial Lipopolysaccharides.

    PubMed

    Chiariotti, Lorenzo; Coretti, Lorena; Pero, Raffaela; Lembo, Francesca

    2016-01-01

    Lipopolysaccharide (LPS) is one of the principal bacterial products known to elicit inflammation. Cells of myeloid lineage such as monocytes and macrophages, but also epithelial cells give rise to an inflammatory response upon LPS stimulation. This phenomenon implies reprogramming of cell specific gene expression that can occur through different mechanisms including epigenetic modifications. Given their intrinsic nature, epigenetic modifications may be involved both in the acute response to LPS and in the establishment of a preconditioned genomic state (epigenomic memory) that may potentially influence the host response to further contacts with microorganisms. Information has accumulated during the last years aimed at elucidating the epigenetic mechanisms which underlie the cellular LPS response. These findings, summarized in this chapter, will hopefully be a good basis for a definition of the complete cascade of LPS-induced epigenetic events and their biological significance in different cell types. PMID:26659265

  10. [Comparative characterisation of lipopolysaccharides of Rahnella aquatills].

    PubMed

    Skokliuk, L B; Varbanets', L D; Pokhyl, S I

    2009-01-01

    Lipopolysaccharides (LPS) of eight strains of R. aquatilis isolated from different sources have been studied. The studies of neutral monosaccharide composition evidence that all of LPS contain galactose (13.4-68.5%), glucose (5.7-29.8%) and heptose (2.6-8.3%) (depending on strains). Some monosaccharides, such as ribose (95U007), rhamnose (95U011, 95U012, 96U036), fucose (95U003, 95U004, 95U007) and mannose (95U012, 96U035, 96U036, 96U037) were absent in LPS. Arabinose was present in two strains--95U003 and 95U007. On the basis of monosaccharide composition all investigated LPS can be divided into six groups. It was shown by double immunodiffusion in agar that all R. aquatilis LPS displayed antigenic activity in homological systems. The results of serological cross reactions indicate the immunochemical heterogeneity of R. aquatilis species. PMID:20455427

  11. Removal of lipopolysaccharides from protein-lipopolysaccharide complexes by nonflammable solvents.

    PubMed

    Lin, Miao-Fang; Williams, Christie; Murray, Michael V; Ropp, Philip A

    2005-02-25

    During the recovery of recombinant proteins from gram negative bacteria, many of the methods used to extract proteins from cells release lipopolysaccharides (LPS, endotoxin) along with the protein of interest. In many instances, LPS will co-purify with the target protein due to specific or non-specific protein-LPS interactions. We have investigated the ability of alkanediols to effect the separation of LPS from protein-LPS complexes while the complexes are immobilized on ion exchange chromatographic resins. Proteins were complexed with fluorescently labeled LPS and bound to ion exchange resin. Alkanediol washes of the resins were preformed and the proteins eluted. Column eluates were monitored for LPS and protein by fluorescence and UV spectroscopy, respectively. Alkanediols were effective agents for dissociating LPS from protein-LPS complexes. The efficiency of LPS removal increased with increasing alkanediol chain length. The 1,2-alkanediol isomers were more effective than terminal alkanediol isomers in the separation of LPS from protein-LPS complexes, while the separation of LPS from protein-LPS complexes was more efficient on cation exchangers than on anion exchangers. In addition, it was noted during these investigations that the 1,2-alkanediols increased the retention time of the proteins on the ion exchange resins. Alkanediols provide a safer alternative to the use of other organics such as alcohols or acetonitrile for the separation of LPS from protein due to their lower toxicity and decreased inflammability. In addition, they are less costly than many of the detergents that have been used for similar purposes. PMID:15664347

  12. Sitagliptin attenuates inflammatory responses in lipopolysaccharide-stimulated cardiomyocytes via nuclear factor-κB pathway inhibition

    PubMed Central

    LIN, CHIEN-HUNG; LIN, CHUNG-CHING

    2016-01-01

    Glucagon-like peptide-1 (GLP-1) and GLP-1 receptors (GLP-1Rs) are responsible for glucose homeostasis, and have been shown to reduce inflammation in preclinical studies. The aim of the present study was to determine whether sitagliptin, an inhibitor of the enzyme dipeptidyl peptidase-4 (DPP-4), as a GLP-1 receptor agonist, exerts an anti-inflammatory effect on cardiomyoblasts during lipopolysaccharide (LPS) stimulation. Exposure to LPS increased the expression levels of tumor necrosis factor (TNF)-α, interleukin-6 (IL)-6 and IL-1β in H9c2 cells, and also resulted in elevations in cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression and nuclear factor-κB (NF-κB) nuclear translocation. Treatment with the DPP-4 inhibitor sitagliptin dose-dependently downregulated the mRNA levels of IL-6, COX-2 and iNOS in LPS-stimulated H9c2 cells. In addition, sitagliptin inhibited the increased protein expression of IL-6, TNF-α and IL-1β. NF-κB mRNA expression was reduced and its translocation to the nucleus was suppressed by treatment with sitagliptin. The present results demonstrated that sitagliptin exerts a beneficial effect on cardiomyoblasts exposed to LPS by inhibiting expression of inflammatory mediators and suppressing NF-κB activation. These findings indicate that the DPP-4 inhibitor sitagliptin may serve a function in cardiac remodeling attributed to sepsis-induced inflammation. PMID:27284355

  13. LPS from Porphyromonas gingivalis Sensitizes Capsaicin-Sensitive Nociceptors

    PubMed Central

    Ferraz, Caio Cezar Randi; Diógenes, Aníbal; Henry, Michael A.; Hargreaves, Kenneth M.

    2010-01-01

    Although odontogenic infections are often accompanied by pain, little is known about the potential mechanisms mediating this effect. In this study, we tested the hypothesis that trigeminal nociceptive neurons are directly sensitized by lipopolysaccharide (LPS) isolated from an endodontic pathogen, Porphyromonas gingivalis (P. gingivalis). In vitro studies conducted with cultures of rat trigeminal neurons demonstrated that pretreatment with LPS produced a significant increase in the capsaicin-evoked release of calcitonin gene-related peptide (CGRP) when compared to vehicle pretreatment, thus showing sensitization of the capsaicin receptor, TRPV1, by LPS. Furthermore, confocal microscopic examination of human tooth pulp samples showed the colocalization of the LPS receptor (toll-like receptor 4; TLR4) with CGRP containing nerve fibers. Collectively, these results suggest the direct sensitization of nociceptors by LPS at concentrations found in infected canal systems as one mechanism responsible for the pain associated with bacterial infections. PMID:21146075

  14. Variation in Microbiome LPS Immunogenicity Contributes to Autoimmunity in Humans.

    PubMed

    Vatanen, Tommi; Kostic, Aleksandar D; d'Hennezel, Eva; Siljander, Heli; Franzosa, Eric A; Yassour, Moran; Kolde, Raivo; Vlamakis, Hera; Arthur, Timothy D; Hämäläinen, Anu-Maaria; Peet, Aleksandr; Tillmann, Vallo; Uibo, Raivo; Mokurov, Sergei; Dorshakova, Natalya; Ilonen, Jorma; Virtanen, Suvi M; Szabo, Susanne J; Porter, Jeffrey A; Lähdesmäki, Harri; Huttenhower, Curtis; Gevers, Dirk; Cullen, Thomas W; Knip, Mikael; Xavier, Ramnik J

    2016-05-01

    According to the hygiene hypothesis, the increasing incidence of autoimmune diseases in western countries may be explained by changes in early microbial exposure, leading to altered immune maturation. We followed gut microbiome development from birth until age three in 222 infants in Northern Europe, where early-onset autoimmune diseases are common in Finland and Estonia but are less prevalent in Russia. We found that Bacteroides species are lowly abundant in Russians but dominate in Finnish and Estonian infants. Therefore, their lipopolysaccharide (LPS) exposures arose primarily from Bacteroides rather than from Escherichia coli, which is a potent innate immune activator. We show that Bacteroides LPS is structurally distinct from E. coli LPS and inhibits innate immune signaling and endotoxin tolerance; furthermore, unlike LPS from E. coli, B. dorei LPS does not decrease incidence of autoimmune diabetes in non-obese diabetic mice. Early colonization by immunologically silencing microbiota may thus preclude aspects of immune education. PMID:27133167

  15. Pseudomonas aeruginosa bacteriophage phi PLS27-lipopolysaccharide interactions.

    PubMed Central

    Jarrell, K F; Kropinski, A M

    1981-01-01

    We investigated the phi PLS27 receptor in Pseudomonas aeruginosa strain PAO lipopolysaccharide (LPS) by analyzing a resistant mutant. This mutant, which was designated AK1282, had the most defective LPS yet reported for a P. aeruginosa rough mutant; this LPS contained only lipid A, 2-keto-3-deoxyoctonate, heptose, and alanine as major components. In addition, this LPS lacked galactosamine, which is present in the inner core of the LPS of other rough mutants. The loss of galactosamine but only a small decrease in the alanine content indicated that the core of strain PAO LPS differed from the core structure which has been suggested for the LPS of other well-characterized P. aeruginosa strains. Our analysis also indicated that galactosamine residues may be crucial for phi PLS27 receptor activity of the LPS. Electrodialysis of LPS and conversion to salt forms (sodium or triethylamine) influenced the phage-inactivating capacity of the LPS, as did the medium in which the inactivation occurred; experiments performed in 1/10-strength broth resulted in much lower PhI50 (concentration of LPS causing a 50% decrease in the titer of phage during 1 h of incubation at 37 degrees C) values than experiments performed in regular-strength broth. Sonication of the LPS also increased the phage-inactivating capacities of the LPS preparations. PMID:6798225

  16. Lipopolysaccharide Endotoxins

    PubMed Central

    Raetz, Christian R. H.; Whitfield, Chris

    2008-01-01

    Summary Since lipopolysaccharide endotoxins of Gram-negative bacteria were last reviewed in this series in 1990, much has been learned about the assembly and signaling functions of these remarkable glycoconjugates. Lipopolysaccharides typically consist of a hydrophobic domain known as lipid A (or endotoxin), a non-repeating “core” oligosaccharide, and a distal polysaccharide (or O-antigen). The flood of recent genomic data has made it possible to study lipopolysaccharide assembly in diverse Gram-negative bacteria, many of which are human or plant pathogens, and to create mutants or hybrid constructs with novel properties. Unexpectedly, key genes for lipid A biosynthesis have also been found in higher plants, indicating that eucaryotic lipid A-like molecules may exist. The carbohydrate diversity of lipopolysaccharides is better appreciated now than ten years ago, but much remains to be learned about function. Sequence comparisons suggest that extensive lateral transfer of genes for the assembly of O-antigens has occurred among bacteria. The most significant finding in the field of endotoxin biology since 1990 has been the identification of the plasma membrane protein TLR4 as the lipid A signaling receptor of animal cells. The latter belongs to a family of innate immunity receptors, all of which possess a large extracellular domain of leucine-rich repeats, a single trans-membrane segment and a smaller cytoplasmic signaling region that engages the adaptor protein MyD88. The expanding knowledge of TLR4 specificity and its downstream signaling pathways should provide new opportunities for blocking the inflammatory side effects of sepsis. Future progress will require insights into lipopolysaccharide-protein recognition at the atomic level, greater understanding of intra- and inter-cellular lipopolysaccharide trafficking, and incisive biological approaches that combine the tools of bacterial and animal genetics. PMID:12045108

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

    SciTech Connect

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

    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.

  18. Sirtuin 4 Regulates Lipopolysaccharide Mediated Leydig Cell Dysfunction.

    PubMed

    Ramatchandirin, Balamurugan; Sadasivam, Mohanraj; Kannan, Arun; Prahalathan, Chidambaram

    2016-04-01

    Bacterial lipopolysaccharide (LPS) is the most important contributing factor in pathogenesis of bacterial infection in male accessory glands; and it has shown to inhibit testicular steroidogenesis and induce apoptosis. The present study demonstrates that LPS causes mitochondrial dysfunction via suppression of sirtuin 4 (SIRT4); which in turn affects Leydig cell function by modulating steroidogenesis and apoptosis. LC-540 Leydig cells treated with LPS (10 µg/ml) showed impaired steroidogenesis and increased cellular apoptosis. The mRNA and protein expression of SIRT4 were decreased in LPS treated cells when compared to controls. The obtained data suggest that the c-Jun N-terminal kinase (JNK) activation suppresses SIRT4 expression in LPS treated Leydig cells. Furthermore, the overexpression of SIRT4 prevented LPS induced impaired steroidogenesis and cellular apoptosis by improving mitochondrial function. These findings provide valuable information that SIRT4 regulates LPS mediated Leydig cell dysfunction. PMID:26365714

  19. VISUALIZATION AND ANALYSIS OF LPS DISTRIBUTION IN BINARY PHOSPHOLIPID BILAYERS

    PubMed Central

    Florencia, Henning María; Susana, Sanchez; Laura, Bakás

    2010-01-01

    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 rol 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°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. PMID:19324006

  20. Anti-LPS antibodies reduce endotoxemia in whole body Co-60 irradiated primates - A preliminary report

    SciTech Connect

    Wells, M.T.; Gaffin, S.L.; Wessels, B.C.; Brock-Utne, J.G.; Jordaan, J.P. )

    1990-09-01

    A previously established primate model was used to evaluate the role of lipopolysaccharide (LPS, endotoxin) in radiation sickness. Vervet monkeys were Co-60 irradiated with an LD100 exposure and had periodic blood samples taken for the determination of LPS and anti-LPS lgG antibodies and for bacteriological studies. On day 2 postirradiation, primates were treated with either sterile 0.9 percent saline, or equine anti-LPS hyperimmune plasma, or tripotassium-dicitrato-bismuthate (Denol). Results indicate that anti-LPS-treated animals survived significantly longer than both the other groups and, since LPS may cause nausea, vomiting, diarrhea, anorexia, and headaches, it is suggested that Anti-LPS administration may be of value in reducing plasma LPS concentration in humans and improving their performance and survivability. 24 refs.

  1. Structure and Effects of Cyanobacterial Lipopolysaccharides

    PubMed Central

    Durai, Prasannavenkatesh; Batool, Maria; Choi, Sangdun

    2015-01-01

    Lipopolysaccharide (LPS) is a component of the outer membrane of mainly Gram-negative bacteria and cyanobacteria. The LPS molecules from marine and terrestrial bacteria show structural variations, even among strains within the same species living in the same environment. Cyanobacterial LPS has a unique structure, since it lacks heptose and 3-deoxy-d-manno-octulosonic acid (also known as keto-deoxyoctulosonate (KDO)), which are present in the core region of common Gram-negative LPS. In addition, the cyanobacterial lipid A region lacks phosphates and contains odd-chain hydroxylated fatty acids. While the role of Gram-negative lipid A in the regulation of the innate immune response through Toll-like Receptor (TLR) 4 signaling is well characterized, the role of the structurally different cyanobacterial lipid A in TLR4 signaling is not well understood. The uncontrolled inflammatory response of TLR4 leads to autoimmune diseases such as sepsis, and thus the less virulent marine cyanobacterial LPS molecules can be effective to inhibit TLR4 signaling. This review highlights the structural comparison of LPS molecules from marine cyanobacteria and Gram-negative bacteria. We discuss the potential use of marine cyanobacterial LPS as a TLR4 antagonist, and the effects of cyanobacterial LPS on humans and marine organisms. PMID:26198237

  2. Pioglitazone inhibition of lipopolysaccharide-induced nitric oxide synthase is associated with altered activity of p38 MAP kinase and PI3K/Akt

    PubMed Central

    Xing, Bin; Xin, Tao; Hunter, Randy Lee; Bing, Guoying

    2008-01-01

    Background Previous studies have suggested that peroxisome proliferator activated receptor-gamma (PPAR-γ)-mediated neuroprotection involves inhibition of microglial activation and decreased expression and activity of inducible nitric oxide synthase (iNOS); however, the underlying molecular mechanisms have not yet been well established. In the present study we explored: (1) the effect of the PPAR-γ agonist pioglitazone on lipopolysaccharide (LPS)-induced iNOS activity and nitric oxide (NO) generation by microglia; (2) the differential role of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun NH(2)-terminal kinase (JNK), and phosphoinositide 3-kinase (PI3K) on LPS-induced NO generation; and (3) the regulation of p38 MAPK, JNK, and PI3K by pioglitazone. Methods Mesencephalic neuron-microglia mixed cultures, and microglia-enriched cultures were treated with pioglitazone and/or LPS. The protein levels of iNOS, p38 MAPK, JNK, PPAR-γ, PI3K, and protein kinase B (Akt) were measured by western blot. Different specific inhibitors of iNOS, p38MAPK, JNK, PI3K, and Akt were used in our experiment, and NO generation was measured using a nitrite oxide assay kit. Tyrosine hydroxylase (TH)-positive neurons were counted in mesencephalic neuron-microglia mixed cultures. Results Our results showed that pioglitazone inhibits LPS-induced iNOS expression and NO generation, and inhibition of iNOS is sufficient to protect dopaminergic neurons against LPS insult. In addition, inhibition of p38 MAPK, but not JNK, prevented LPS-induced NO generation. Further, and of interest, pioglitazone inhibited LPS-induced phosphorylation of p38 MAPK. Wortmannin, a specific PI3K inhibitor, enhanced p38 MAPK phosphorylation upon LPS stimulation of microglia. Elevations of phosphorylated PPAR-γ, PI3K, and Akt levels were observed with pioglitazone treatment, and inhibition of PI3K activity enhanced LPS-induced NO production. Furthermore, wortmannin prevented the inhibitory effect of pioglitazone on

  3. LPS response and tolerance in the zebrafish (Danio rerio)

    PubMed Central

    Novoa, B.; Bowman, TV.; Zon, L.; Figueras, A

    2009-01-01

    Zebrafish (Danio rerio) has been used in the present work to study the fish response to bacterial lipopolysaccharide (LPS) exposure and LPS tolerance. These mechanisms are not completely understood in mammals and, presently, are totally unknown in fish. Zebrafish larval survival was assessed following treatment with various types of LPS at a variety of concentrations to determine the sensitivity of zebrafish to LPS-induced immune activation. In addition, fish pre-treated with a sublethal concentration of LPS did not die after exposure to a lethal concentration of LPS demonstrating, for the first time, that LPS tolerance also happens in fish. The time interval between pretreatment and secondary exposure as well as the type of pretreatment dictated the strength of protection. Since zebrafish are in intimate contact with microorganisms, the high resistance of fish to LPS suggests that there must be a tight control of the LPS receptor cluster in order to avoid an excess of inflammation. One of these components is CXCR4, which has previously been shown to regulate the signal transduced by TLR4. Treating fish with AMD 3100, a specific inhibitor of CXCR4, increased LPS treatment associated mortality. Blocking CXCR4 via chemical or genetic inhibition resulted in a reversion of LPS tolerance, thus further supporting the negative regulatory role of CXCR4 in this inflammatory response. In support of an inhibitory role for CXCR4 in the inflammatory cascade, IL1 transcript levels were elevated in both unstimulated and LPS stimulated zebrafish Odysseus (CXCR4 deficient mutant) larvae. PMID:19110060

  4. [Characterization of Pantoea agglomerans lipopolysaccharides].

    PubMed

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

    2014-01-01

    Lipopolysaccharides (LPS) from seven Pantoea agglomerans strains isolated from various plants were purified and chemically identified. LPS of the studied P. agglomerans strains were heterogeneous in monosaccharide composition. Thus, the LPS of P. agglomerans 8606 differed considerably from the LPSs of other strains, containing mannose as the predominant monosaccharide (69.8%), as well as ribose (15.1%) and xylose (12.6%), while the content of rhamnose, one of the predominant monosaccharides in other LPS samples, was 2.5%. Analysis of the fatty acid composition revealed the presence of C12-C16 acids. In lipids A of all the studied strains, 3-OH-C14:0 was the predominant acid (31.7 to 39.1%, depending on the strain). C12:0 (8.2 to 31.5%), C14:0 (12.9 to 30.8%), and C16:0 acids (3.4 to 16.9%) were also revealed. The studied P. agglomerans strains fell into three groups according to their fatty acid composition. The differences stemmed from the presence or absence of two fatty acids, 2-OH-C14:0 and C16:1. Ouchterlony double immunodiffusion in agar revealed that all the LPS under study exhibited antigenic activity in homologous systems. The results of serological cross reactions indicated immunochemical heterogeneity of the species P. agglomerans. Comparative investigation of the complex of parameters of peripheral blood cells from a healthy donor before and after treatment with LPS solutions showed that the values of no parameters exceeded the normal range. PMID:25941715

  5. Retinoic acid receptor agonist Am80 inhibits CXCL2 production from microglial BV-2 cells via attenuation of NF-κB signaling.

    PubMed

    Takaoka, Yuichiro; Takahashi, Moeka; Kurauchi, Yuki; Hisatsune, Akinori; Seki, Takahiro; Shudo, Koichi; Katsuki, Hiroshi

    2016-09-01

    Accumulating lines of evidence suggest that retinoic acid receptor agonists such as Am80 exerts anti-inflammatory actions in the central nervous system, although detailed mechanisms of the action remain largely unknown. Our previous findings suggest that Am80 provides therapeutic effect on intracerebral hemorrhage in mice via suppression of expression of chemokine (C-X-C motif) ligand 2 (CXCL2). Here we investigated the mechanisms of inhibitory action of Am80 on expression of CXCL2 and other pro-inflammatory factors in microglial BV-2 cells. Pretreatment with Am80 markedly suppressed lipopolysaccharide (LPS)-induced expression of CXCL2 mRNA and release of CXCL2 protein. Am80 had no effect on LPS-induced activation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase. On the other hand, Am80 prevented LPS-induced nuclear translocation of p65 subunit of NF-κB complex. In addition, total expression levels of p65 and IκBα proteins, as well as of mRNAs encoding p65 and IκBα, were lowered by Am80. Dependence of CXCL2 expression on NF-κB was confirmed by the effect of an NF-κB inhibitor caffeic acid phenethyl ester that abolished LPS-induced CXCL2 expression. Caffeic acid phenethyl ester also abolished LPS-induced expression of inducible nitric oxide synthase, interleukin-1β and tumor necrosis factor α, which may be relevant to the inhibitory effect of Am80 on expression of these pro-inflammatory factors. We additionally found that Am80 attenuated LPS-induced up-regulation of CD14, a co-receptor for Toll-like receptor 4 (TLR4). These results suggest that inhibitory effect on TLR4 signaling mediated by NF-κB pathway underlies the anti-inflammatory action of retinoic acid receptor agonists in microglia. PMID:27351827

  6. Flow cytometric analysis of crayfish haemocytes activated by lipopolysaccharides

    USGS Publications Warehouse

    Cardenas, W.; Dankert, J.R.; Jenkins, J.A.

    2004-01-01

    Lipopolysaccharides (LPS) from Gram-negative bacteria are strong stimulators of white river crayfish, Procambarus zonangulus, haemocytes in vitro. Following haemocyte treatment with LPS and with LPS from rough mutant R5 (LPS Rc) from Salmonella minnesota, flow cytometric analysis revealed a conspicuous and reproducible decrease in cell size as compared to control haemocytes. These LPS molecules also caused a reduction in haemocyte viability as assessed by flow cytometry with the fluorescent dyes calcein-AM and ethidium homodimer. The onset of cell size reduction was gradual and occurred prior to cell death. Haemocytes treated with LPS from S. minnesota without the Lipid A moiety (detoxified LPS) decreased in size without a reduction of viability. The action of LPS on crayfish haemocytes appeared to be related to the activation of the prophenoloxidase system because phenoloxidase (PO)-specific activity in the supernatants from control and detoxified LPS-treated cells was significantly lower than that from LPS and LPS-Rc treated cells (P < 0.05). Furthermore, addition of trypsin inhibitor to the LPS treatments caused noticeable delays in cell size and viability changes. These patterns of cellular activation by LPS formulations indicated that crayfish haemocytes react differently to the polysaccharide and lipid A moieties of LPS, where lipid A is cytotoxic and the polysaccharide portion is stimulatory. These effects concur with the general pattern of mammalian cell activation by LPS, thereby indicting commone innate immune recognition mechanisms to bacterial antigens between cells from mammals and invertebrates. These definitive molecular approaches used to verify and identify mechanisms of invertbrate haemocyte responses to LPS could be applied with other glycoconjugates, soluble mediators, or xenobiotic compounds.

  7. Pasteurella multocida Heddleston serovar 3 and 4 strains share a common lipopolysaccharide biosynthesis locus but display both inter- and intrastrain lipopolysaccharide heterogeneity.

    PubMed

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

    2013-11-01

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

  8. [Modulation of immune response by bacterial lipopolysaccharides].

    PubMed

    Aldapa-Vega, Gustavo; Pastelín-Palacios, Rodolfo; Isibasi, Armando; Moreno-Eutimio, Mario A; López-Macías, Constantino

    2016-01-01

    Lipopolysaccharide (LPS) is a molecule that is profusely found on the outer membrane of Gram-negative bacteria and is also a potent stimulator of the immune response. As the main molecule on the bacterial surface, is also the most biologically active. The immune response of the host is activated by the recognition of LPS through Toll-like receptor 4 (TLR4) and this receptor-ligand interaction is closely linked to LPS structure. Microorganisms have evolved systems to control the expression and structure of LPS, producing structural variants that are used for modulating the host immune responses during infection. Examples of this include Helicobacter pylori, Francisella tularensis, Chlamydia trachomatis and Salmonella spp. High concentrations of LPS can cause fever, increased heart rate and lead to septic shock and death. However, at relatively low concentrations some LPS are highly active immunomodulators, which can induce non-specific resistance to invading microorganisms. The elucidation of the molecular and cellular mechanisms involved in the recognition of LPS and its structural variants has been fundamental to understand inflammation and is currently a pivotal field of research to understand the innate immune response, inflammation, the complex host-pathogen relationship and has important implications for the rational development of new immunomodulators and adjuvants. PMID:27560917

  9. Lipopolysaccharide mutants of Rhizobium meliloti are not defective in symbiosis

    SciTech Connect

    Clover, R.H.; Kieber, J.; Signer, E.R. )

    1989-07-01

    Mutants of Rhizobium meliloti selected primarily for bacteriophage resistance fall into 13 groups. Mutants in the four best-characterized groups (class A, lpsB, lpsC, and class D), which map to the rhizobial chromosome, appear to affect lipopolysaccharide (LPS) as judged by the reactivity with monoclonal antibodies and behavior on sodium dodecyl sulfate-polyacrylamide gels of extracted LPS. Mutations in all 13 groups, in an otherwise wild-type genetic background, are Fix{sup +} on alfalfa. This suggests that LPS does not play a major role in symbiosis. Mutations in lpsB, however, are Fix{sup {minus}} in one particular genetic background, evidently because of the cumulative effect of several independent background mutations. In addition, an auxotrophic mutation evidently equivalent to Escherichia coli carAB is Fix{sup {minus}} on alfalfa.

  10. Lipopolysaccharide aggravates bisphosphonate-induced osteonecrosis in rats.

    PubMed

    Sakaguchi, O; Kokuryo, S; Tsurushima, H; Tanaka, J; Habu, M; Uehara, M; Nishihara, T; Tominaga, K

    2015-04-01

    The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is highly controversial. We have previously reported the development of osteonecrosis by periodontal pathogenic stimulation in the jaw and femur of rats treated with bisphosphonate. Since the major toxicity factor of Gram-negative bacteria is lipopolysaccharide (LPS), the present study aimed to evaluate the relationship between osteonecrosis and LPS in a rat model of BRON-like lesions. Seventeen male rats were injected subcutaneously with zoledronic acid weekly for 4 weeks and divided into three groups: LPS (LPS administered into the bone marrow of the mandible and femur) and LPS plus polymyxin B (PMB) and saline groups (given neutralized LPS with PMB or saline, respectively, using the same protocol). At 4 weeks after the procedure, harvested specimens were analyzed using histomorphology (n=5 from each group) and histochemistry (n=1 each from LPS and LPS plus PMB groups). There was a significantly wider area of osteonecrosis in the LPS group as compared to the saline and LPS plus PMB groups in both the mandible (P=0.030 and P=0.009, respectively) and femur (P=0.002 and P=0.020, respectively). Our results indicate that LPS stimulation is deeply involved in the development and promotion of BRON. PMID:25442743

  11. Biological and physicochemical properties of the lipopolysaccharide of Chromatium vinosum.

    PubMed Central

    Hurlbert, R E; Hurlbert, I M

    1977-01-01

    The lipopolysaccharide (LPS) of Chromatium vinosum has anticomplementary activity. This anticomplementary activity is destroyed by alkaline digestion of the LPS and is suppressed by both Mg2+ and Ca2+ ions. Treatment of the LPS with ethylenediaminetetraacetic acid, sodium deoxycholate, or dimethyl sulfoxide did not affect its toxicity toward mice; however, alkaline-treated LPS was not toxic. Treatment of the LPS with sodium deoxycholate, dimethyl sulfoxide, or sodium dodecyl sulfate resulted in reversible dissociation into subunits. Aggregation of the subunits into the original form was achieved by removing the dispersing agent by dialysis against distilled water followed by freezing and thawing. Electron micrographs of phenol-extracted LPS showed long filaments. Electron micrographs of sodium deoxycholate- and sodium dodecyl sulfate-treated and dialyzed LPS showed a mixture of small subunits and short filaments, whereas dimethyl sulfoxide-treated and dialyzed LPS contained only small ovoid spheres. The LPS produced an ordered series of multiple bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A similar banding pattern was observed for Salmonella abortus-equi and Proteus mirabilis LPS. The C. vinosum LPS appears to be mitogenic for mouse spleen cells. Images PMID:892903

  12. Modulation of Lipopolysaccharide-Induced Chorioamnionitis in Fetal Sheep by Maternal Betamethasone

    PubMed Central

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

    2013-01-01

    Objective: 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. Study Design: 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. Results: 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. Conclusions: 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. PMID:23653388

  13. Binding of Salmonella typhimurium lipopolysaccharides to rat high-density lipoproteins.

    PubMed Central

    Munford, R S; Hall, C L; Dietschy, J M

    1981-01-01

    These studies were undertaken to investigate the binding of gram-negative bacterial lipopolysaccharides (LPS) to high-density lipoproteins (HDL) of rat plasma. Purified Salmonella typhimurium LPS, intrinsically labeled with [3H]-galactose, bound rapidly in vitro to isolated rat HDL. Maximal binding of LPS to HDL occurred when LPS and HDL were incubated with lipoprotein-free plasma (rho greater than 1.21 g/ml). Since LPS, when purified, form large aggregates, we tested the hypothesis that disaggregation of LPS enhances LPS-HDL binding. We found that calcium chloride (1 mM), an agent which prevents LPS disaggregation, inhibited binding of LPS to HDL by interfering with the modification of LPS by lipoprotein-free plasma. Conversely, sodium deoxycholate (0.15 g/dl), which disaggregates LPS, greatly increased binding of LPS to HDL in the absence of lipoprotein-free plasma. Analysis of labeled LPS by sodium deodecyl sulfate-polyacrylamide gel electrophoresis showed only minor differences in the sizes of LPS molecules before and after binding to HDL, suggesting that chemical modification of LPS is not required for binding. The results provide evidence that disaggregation increases the binding of LPS to HDL. PMID:7037642

  14. Helicobacter pylori lipopolysaccharide can activate 70Z/3 cells via CD14.

    PubMed Central

    Kirkland, T; Viriyakosol, S; Perez-Perez, G I; Blaser, M J

    1997-01-01

    Helicobacter pylori persistently colonizes the human gastrointestinal tract and is associated with chronic gastritis and, in some cases, peptic ulcer disease or gastric neoplasms. One factor in the persistence of this organism may be its inability to elicit a strong inflammatory response. Lipopolysaccharide (LPS) is a proinflammatory substance found in the cell walls of all gram-negative bacteria. H. pylori LPS has been found by several different measures to be less active than LPS from Enterobacteriaceae. This study addresses the role of CD14 and LPS-binding protein in the cellular response to H. pylori LPS. We report that H. pylori LPS activates mammalian cells expressing CD14 at much lower LPS concentrations than those for control cells not expressing CD14. The maximal activation of CD14-70Z/3 cells by H. pylori LPS also requires LPS-binding protein. H. pylori LPS at concentrations as high as 30 microg/ml does not elicit an interleukin-8 (IL-8) response from the epithelial cell line SW620 in the presence of CD14; 10 ng of Escherichia coli LPS per ml elicits a maximal IL-8 response. Furthermore, in contrast to some other types of LPS with little activity, H. pylori LPS does not inhibit the CD14-70Z/3 cell response to E. coli LPS. From these studies, we conclude that H. pylori LPS, though much less active than E. coli LPS, stimulates cells via CD14. PMID:9009319

  15. Characterization of the apoLp-III/LPS complex: insight in the mode of binding interaction

    PubMed Central

    Oztug, Merve; Martinon, Daisy; Weers, Paul M.M.

    2012-01-01

    Apolipoproteins are able to associate with lipopolysaccharides (LPS), potentially providing protection against septic shock. To gain insight in the molecular details of this binding interaction, apolipophorin III (apoLp-III) from Galleria mellonella was used as a model. The binding of apoLp-III to LPS was optimal around 37–40 °C, close to the LPS phase transition temperature. ApoLp-III formed complexes with LPS from E. coli (serotype O55:B5) with a diameter of 24 nm, a molecular weight of ~390 kDa, containing four molecules of apoLp-III and 24 molecules of LPS. The LPS-bound form of the protein was substantially more resistant to guanidine-induced denaturation compared to unbound protein. The denaturation profile displayed a multiphase character with a steep drop in secondary structure between 0–1 M guanidine, and a slower decrease above 1 M guanidine HCl. In contrast, apoLp-III bound to detoxified LPS was only slightly more resistant to guanidine HCl induced denaturation compared to unbound protein. Analysis of size-exclusion FPLC elution profiles of mixtures of apoLp-III with LPS or detoxified LPS indicated a much weaker binding interaction with detoxified LPS compared to intact LPS. These results indicate that apoLp-III initially interacts with exposed carbohydrate regions, but that the lipid A region is required for a more stable LPS binding interaction. PMID:22779761

  16. Activation of AMPK attenuates LPS-induced acute lung injury by upregulation of PGC1α and SOD1

    PubMed Central

    Wang, Guizuo; Song, Yang; Feng, Wei; Liu, Lu; Zhu, Yanting; Xie, Xinming; Pan, Yilin; Ke, Rui; Li, Shaojun; Li, Fangwei; Yang, Lan; Li, Manxiang

    2016-01-01

    Evidence suggests that an imbalance between oxidation and antioxidation is involved in the pathogenesis of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Activation of AMP-activated protein kinase (AMPK) has been shown to inhibit the occurrence of ALI/ARDS. However, it is unknown whether activation of AMPK benefits ALI/ARDS by restoration of the oxidant and antioxidant balance, and which mechanisms are responsible for this process. The present study aimed to address these issues. Lipopolysaccharide (LPS) induced pronounced pathological changes of ALI in mice; these were accompanied by elevated production of malondialdehyde (MDA) and decreased activity of superoxide dismutase (SOD) compared with control mice. Prior treatment of mice with the AMPK agonist metformin significantly suppressed the LPS-induced development of ALI, reduced the elevation of MDA and increased the activity of SOD. Further analysis indicated that activation of AMPK also stimulated the protein expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and superoxide dismutase 1 (SOD1). This study suggests that activation of AMPK by metformin inhibits oxidative stress by upregulation of PGC1α and SOD1, thereby suppressing the development of ALI/ARDS, and has potential value in the clinical treatment of such conditions. PMID:27602077

  17. HYDROGEN-RICH MEDIUM AMELIORATES LIPOPOLYSACCHARIDE-INDUCED BARRIER DYSFUNCTION VIA RHOA-MDIA1 SIGNALING IN CACO-2 CELLS

    PubMed Central

    Yang, Tao; Wang, Lu; Sun, Ruiqiang; Chen, Hongguang; Zhang, Hongtao; Yu, Yang; Wang, Yanyan; Wang, Guolin; Yu, Yonghao; Xie, Keliang

    2016-01-01

    ABSTRACT Gastrointestinal barrier dysfunction is associated with the severity and prognosis of sepsis. Hydrogen gas (H2) can ameliorate multiple organ damage in septic animals. Ras homolog gene family member A (RhoA) and mammalian diaphanous-related formin 1 (mDia1) are important to regulate tight junction (TJ) and adherens junction (AJ), both of which determine the integrity of the intestinal barrier. This study was aimed to investigate whether H2 could modulate lipopolysaccharide (LPS)-stimulated dysfunction of the intestinal barrier and whether RhoA-mDia1 signaling is involved. Caco-2 cells were exposed to different concentrations of LPS (1 μg/mL–1 mg/mL). The permeability of the intestinal barrier was evaluated by transepithelial resistance (TER) and fluorescein-isothiocyanate-dextran flux. Expression and distribution of occludin and E-cadherin were analyzed by Western blot and immunofluorescence. RhoA activity was measured by G-Lisa assay, and mDia1 expression was assessed by Western blot. LPS (100 μg/mL) decreased TER and increased fluorescein-isothiocyanate-dextran flux, which were alleviated by H2-rich medium. Also, H2 down-regulated LPS-induced oxidative stress. Moreover, H2 improved the down-regulated expression and redistribution of occludin and E-cadherin caused by LPS. Additionally, H2 alleviated LPS-caused RhoA activation, and the beneficial effects of H2 on barrier were counteracted by RhoA agonist CN03. Rho inhibitor C3 exoenzyme mitigated LPS-induced barrier breakdown. Furthermore, H2-rich medium increased mDia1 expression, and mDia1 knockdown abolished protections of H2 on barrier permeability. mDia1 knockdown eliminated H2-induced benefits for occludin and E-cadherin. These findings suggest that H2 improves LPS-induced hyperpermeability of the intestinal barrier and disruptions of TJ and AJ by moderating RhoA-mDia1 signaling. PMID:26529665

  18. Lack of LCAT reduces the LPS-neutralizing capacity of HDL and enhances LPS-induced inflammation in mice.

    PubMed

    Petropoulou, Peristera-Ioanna; Berbée, Jimmy F P; Theodoropoulos, Vassilios; Hatziri, Aikaterini; Stamou, Panagiota; Karavia, Eleni A; Spyridonidis, Alexandros; Karagiannides, Iordanes; Kypreos, Kyriakos E

    2015-10-01

    HDL has important immunomodulatory properties, including the attenuation of lipopolysaccharide (LPS)-induced inflammatory response. As lecithin-cholesterol acyltransferase (LCAT) is a critical enzyme in the maturation of HDL we investigated whether LCAT-deficient (Lcat(-/-)) mice present an increased LPS-induced inflammatory response. LPS (100μg/kg body weight)-induced cytokine response in Lcat(-/-) mice was markedly enhanced and prolonged compared to wild-type mice. Importantly, reintroducing LCAT expression using adenovirus-mediated gene transfer reverted their phenotype to that of wild-type mice. Ex vivo stimulation of whole blood with LPS (1-100ng/mL) showed a similar enhanced pro-inflammatory phenotype. Further characterization in RAW 264.7 macrophages in vitro showed that serum and HDL, but not chylomicrons, VLDL or the lipid-free protein fraction of Lcat(-/-) mice, had a reduced capacity to attenuate the LPS-induced TNFα response. Analysis of apolipoprotein composition revealed that LCAT-deficient HDL lacks significant amounts of ApoA-I and ApoA-II and is primarily composed of ApoE, while HDL from Apoa1(-/-) mice is highly enriched in ApoE and ApoA-II. ApoA-I-deficiency did not affect the capacity of HDL to neutralize LPS, though Apoa1(-/-) mice showed a pronounced LPS-induced cytokine response. Additional immunophenotyping showed that Lcat(-/-) , but not Apoa1(-/-) mice, have markedly increased circulating monocyte numbers as a result of increased Cd11b(+)Ly6C(med) monocytes, whereas 'pro-inflammatory' Cd11b(+)Ly6C(hi) monocytes were reduced. In line with this observation, peritoneal macrophages of Lcat(-/-) mice showed a markedly dampened LPS-induced TNFα response. We conclude that LCAT-deficiency increases LPS-induced inflammation in mice due to reduced LPS-neutralizing capacity of immature discoidal HDL and increased monocyte number. PMID:26170061

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. GENE EXPRESSION PROFILING OF BOVINE MACROPHAGES IN RESPONSE TO ESCHERICHIA COLI O157:H7 LIPOPOLYSACCHARIDE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to identify changes in bovine macrophage gene expression in response to treatment with Escherichia coli 0157:H7 lipopolysaccharide (LPS), utilizing a human gene microarray. Bovine cDNA from control and LPS-treated primary macrophages hybridized to greater than 5,644 (79.8%)...

  1. EFFECTS OF CHRONIC EXERCISE CONDITIONING ON THERMAL RESPONSES TO LIPOPOLYSACCHARIDE AND TURPENTINE ABSCESS IN FEMALE RATS.

    EPA Science Inventory

    Chronic exercise conditioning has been shown to alter basal thermoregulatory processes as well as the response to inflammatory agents. Two such agents, lipopolysaccharide (LPS) and turpentine (TPT) are inducers of fever in rats. LPS, given intraperitoneally (i.p.), involves a sys...

  2. Profile of the bovine acute-phase response following an intravenous bolus-dose lipopolysaccharide challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to further define the acute-phase response to a lipopolysaccharide (LPS) challenge in beef steers. In Exp. 1, 9 crossbred beef steers (449 ± 12 kg BW) were used in a completely random design to determine the effects of 0.5, 1.0, or 2.0 micrograms of LPS/kilogram of bod...

  3. Toxicity and immunogenicity of Neisseria meningitidis lipopolysaccharide incorporated into liposomes.

    PubMed Central

    Petrov, A B; Semenov, B F; Vartanyan, Y P; Zakirov, M M; Torchilin, V P; Trubetskoy, V S; Koshkina, N V; L'Vov, V L; Verner, I K; Lopyrev, I V

    1992-01-01

    To obtain nontoxic and highly immunogenic lipopolysaccharide (LPS) for immunization, we incorporated Neisseria meningitidis LPS into liposomes. Native LPS and its salts were incorporated by the method of dehydration-rehydration of vesicles or prolonged cosonication. The most complete incorporation of LPS into liposomes and a decrease in toxicity were achieved by the method of dehydration-rehydration of vesicles. Three forms of LPS (H+ form, Mg2+ salt, and triethanolamine salt) showed different solubilities in water, the acidic form of LPS, with the most pronounced hydrophobic properties, being capable of practically complete association with liposomal membranes. An evaluation of the activity of liposomal LPS in vitro (by the Limulus amoebocyte test) and in vivo (by monitoring the pyrogenic reaction in rabbits) revealed a decrease in endotoxin activity of up to 1,000-fold. In addition, the pyrogenic activity of liposomal LPS was comparable to that of a meningococcal polysaccharide vaccine. Liposomes had a pronounced adjuvant effect on the immune response to LPS. Thus, the level of anti-LPS plaque-forming cells in the spleens of mice immunized with liposomal LPS was 1 order of magnitude higher and could be observed for a longer time (until day 21, i.e., the term of observation) than in mice immunized with free LPS. The same regularity was revealed in a study done with an enzyme-linked immunosorbent assay. This study also established that antibodies induced by immunization belonged to the immunoglobulin M and G classes, which are capable of prolonged circulation. Moreover, liposomal LPS induced a pronounced immune response in CBA/N mice (defective in B lymphocytes of the LyB-5+ subpopulation). The latter results indicate that the immunogenic action of liposomal LPS occurs at an early age. PMID:1500196

  4. Toxicity and immunogenicity of Neisseria meningitidis lipopolysaccharide incorporated into liposomes.

    PubMed

    Petrov, A B; Semenov, B F; Vartanyan, Y P; Zakirov, M M; Torchilin, V P; Trubetskoy, V S; Koshkina, N V; L'Vov, V L; Verner, I K; Lopyrev, I V

    1992-09-01

    To obtain nontoxic and highly immunogenic lipopolysaccharide (LPS) for immunization, we incorporated Neisseria meningitidis LPS into liposomes. Native LPS and its salts were incorporated by the method of dehydration-rehydration of vesicles or prolonged cosonication. The most complete incorporation of LPS into liposomes and a decrease in toxicity were achieved by the method of dehydration-rehydration of vesicles. Three forms of LPS (H+ form, Mg2+ salt, and triethanolamine salt) showed different solubilities in water, the acidic form of LPS, with the most pronounced hydrophobic properties, being capable of practically complete association with liposomal membranes. An evaluation of the activity of liposomal LPS in vitro (by the Limulus amoebocyte test) and in vivo (by monitoring the pyrogenic reaction in rabbits) revealed a decrease in endotoxin activity of up to 1,000-fold. In addition, the pyrogenic activity of liposomal LPS was comparable to that of a meningococcal polysaccharide vaccine. Liposomes had a pronounced adjuvant effect on the immune response to LPS. Thus, the level of anti-LPS plaque-forming cells in the spleens of mice immunized with liposomal LPS was 1 order of magnitude higher and could be observed for a longer time (until day 21, i.e., the term of observation) than in mice immunized with free LPS. The same regularity was revealed in a study done with an enzyme-linked immunosorbent assay. This study also established that antibodies induced by immunization belonged to the immunoglobulin M and G classes, which are capable of prolonged circulation. Moreover, liposomal LPS induced a pronounced immune response in CBA/N mice (defective in B lymphocytes of the LyB-5+ subpopulation). The latter results indicate that the immunogenic action of liposomal LPS occurs at an early age. PMID:1500196

  5. Deletion of Monoglyceride Lipase in Astrocytes Attenuates Lipopolysaccharide-induced Neuroinflammation*

    PubMed Central

    Grabner, Gernot F.; Eichmann, Thomas O.; Wagner, Bernhard; Gao, Yuanqing; Farzi, Aitak; Taschler, Ulrike; Radner, Franz P. W.; Schweiger, Martina; Lass, Achim; Holzer, Peter; Zinser, Erwin; Tschöp, Matthias H.; Yi, Chun-Xia; Zimmermann, Robert

    2016-01-01

    Monoglyceride lipase (MGL) is required for efficient hydrolysis of the endocannabinoid 2-arachidonoylglyerol (2-AG) in the brain generating arachidonic acid (AA) and glycerol. This metabolic function makes MGL an interesting target for the treatment of neuroinflammation, since 2-AG exhibits anti-inflammatory properties and AA is a precursor for pro-inflammatory prostaglandins. Astrocytes are an important source of AA and 2-AG, and highly express MGL. In the present study, we dissected the distinct contribution of MGL in astrocytes on brain 2-AG and AA metabolism by generating a mouse model with genetic deletion of MGL specifically in astrocytes (MKOGFAP). MKOGFAP mice exhibit moderately increased 2-AG and reduced AA levels in brain. Minor accumulation of 2-AG in the brain of MKOGFAP mice does not cause cannabinoid receptor desensitization as previously observed in mice globally lacking MGL. Importantly, MKOGFAP mice exhibit reduced brain prostaglandin E2 and pro-inflammatory cytokine levels upon peripheral lipopolysaccharide (LPS) administration. These observations indicate that MGL-mediated degradation of 2-AG in astrocytes provides AA for prostaglandin synthesis promoting LPS-induced neuroinflammation. The beneficial effect of astrocyte-specific MGL-deficiency is not fully abrogated by the inverse cannabinoid receptor 1 agonist SR141716 (Rimonabant) suggesting that the anti-inflammatory effects are rather caused by reduced prostaglandin synthesis than by activation of cannabinoid receptors. In conclusion, our data demonstrate that MGL in astrocytes is an important regulator of 2-AG levels, AA availability, and neuroinflammation. PMID:26565024

  6. Interaction of uranium(VI) with lipopolysaccharide.

    PubMed

    Barkleit, Astrid; Moll, Henry; Bernhard, Gert

    2008-06-01

    Bacteria have a great influence on the migration behaviour of heavy metals in the environment. Lipopolysaccharides form the main part of the outer membrane of Gram-negative bacteria. We investigated the interaction of the uranyl cation (UO2(2+)) with lipopolysaccharide (LPS) from Pseudomonas aeruginosa by using potentiometric titration and time-resolved laser-induced fluorescence spectroscopy (TRLFS) over a wide pH and concentration range. Generally, LPS consists of a high density of different functionalities for metal binding such as carboxyl, phosphoryl, amino and hydroxyl groups. The dissociation constants and corresponding site densities of these functional groups were determined using potentiometric titration. The combination of both methods, potentiometry and TRLFS, show that at an excess of LPS uranyl phosphoryl coordination dominates, whereas at a slight deficit on LPS compared to uranyl, carboxyl groups also become important for uranyl coordination. The stability constants of one uranyl carboxyl complex and three different uranyl phosphoryl complexes and the luminescence properties of the phosphoryl complexes are reported. PMID:18478152

  7. Lipopolysaccharide-Induced Toxic Shock Syndrome in Rabbits.

    PubMed

    Stach, Christopher S; Schlievert, Patrick M

    2016-01-01

    Enhancement of susceptibility to lipopolysaccharide (LPS; endotoxin) is a defining characteristic of Staphylococcus aureus superantigens. At the time of this publication, there are 24 identified staphylococcal superantigens (SAgs), some of which have yet to be fully characterized. Testing the capacity of superantigens to potentiate LPS sensitivity is essential to characterize the role of these proteins in disease development. Here we describe how to perform studies of the enhancement of LPS-induced toxic shock syndrome in rabbits. This protocol also provides information on a second important activity of superantigens: the production of fever. PMID:26676037

  8. Neuroprotective Activity of (−)-Epigallocatechin Gallate against Lipopolysaccharide-Mediated Cytotoxicity

    PubMed Central

    Liu, Jin-Biao; Zhou, Li; Wang, Yi-Zhong; Wang, Xu; Zhou, Yu; Ho, Wen-Zhe; Li, Jie-Liang

    2016-01-01

    Lipopolysaccharide- (LPS-) mediated systemic inflammation plays a critical role in neurodegenerative diseases. The present study was conducted to evaluate the protective effects of epigallocatechin gallate (EGCG), the major component in green tea, on LPS-mediated inflammation and neurotoxicity. LPS treatment of macrophages induced expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). However, EGCG pretreatment of macrophages significantly inhibited LPS-mediated induction of these cytokines. In addition, EGCG significantly diminished LPS-induced inflammatory cytokines in the peripheral mononuclear blood cells (PBMCs). Supernatant from EGCG-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-EGCG-pretreated and LPS-activated macrophage cultures. Furthermore, EGCG treatment of neurons could inhibit LPS-induced production of reactive oxygen species (ROS). Thus EGCG represents a potent and useful neuroprotective agent for inflammation-mediated neurological disorders. PMID:27191001

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

    PubMed Central

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

    2015-01-01

    Lipopolysaccharides (LPS) are a component of the outer cell surface of almost all Gram-negative bacteria and play an essential role for bacterial growth and survival. Lipopolysaccharides represent typical microbe-associated molecular pattern (MAMP) molecules and have been reported to induce defense-related responses, including the expression of defense genes and the suppression of the hypersensitive response in plants. However, depending on their origin and the challenged plant, LPS were shown to have complex and different roles. In this study we showed that LPS from plant pathogens Pectobacterium atrosepticum and Pectobacterium carotovorum subsp. carotovorum induce common and different responses in A. thaliana cells when compared to those induced by LPS from non-phytopathogens Escherichia coli and Pseudomonas aeruginosa. Among common responses to both types of LPS are the transcription of defense genes and their ability to limit of cell death induced by Pectobacterium carotovorum subsp carotovorum. However, the differential kinetics and amplitude in reactive oxygen species (ROS) generation seemed to regulate defense gene transcription and be determinant to induce programmed cell death in response to LPS from the plant pathogenic Pectobacterium. These data suggest that different signaling pathways could be activated by LPS in A. thaliana cells. PMID:25760034

  10. Effects of the TLR2 Agonists MALP-2 and Pam3Cys in Isolated Mouse Lungs

    PubMed Central

    Barrenschee, Martina; Lex, Dennis; Uhlig, Stefan

    2010-01-01

    Background Gram-positive and Gram-negative bacteria are main causes of pneumonia or acute lung injury. They are recognized by the innate immune system via toll-like receptor-2 (TLR2) or TLR4, respectively. Among all organs, the lungs have the highest expression of TLR2 receptors, but little is known about the pulmonary consequences of their activation. Here we studied the effects of the TLR2/6 agonist MALP-2, the TLR2/1 agonist Pam3Cys and the TLR4 agonist lipopolysaccharide (LPS) on pro-inflammatory responses in isolated lungs. Methodology/Principal Findings Isolated perfused mouse lungs were perfused for 60 min or 180 min with MALP-2 (25 ng/mL), Pam3Cys (160 ng/mL) or LPS (1 µg/mL). We studied mediator release by enzyme linked immunosorbent assay (ELISA), the activation of mitogen activated protein kinase (MAPK) and AKT/protein kinase B by immunoblotting, and gene induction by quantitative polymerase chain reaction. All agonists activated the MAPK ERK1/2 and p38, but neither JNK or AKT kinase. The TLR ligands upregulated the inflammation related genes Tnf, Il1β, Il6, Il10, Il12, Ifng, Cxcl2 (MIP-2α) and Ptgs2. MALP-2 was more potent than Pam3Cys in inducing Slpi, Cxcl10 (IP10) and Parg. Remarkable was the strong induction of Tnc by MALP2, which was not seen with Pam3Cys or LPS. The growth factor related genes Areg and Hbegf were not affected. In addition, all three TLR agonists stimulated the release of IL-6, TNF, CXCL2 and CXCL10 protein from the lungs. Conclusions/Significance TLR2 and TLR4 activation leads to similar reactions in the lungs regarding MAPK activation, gene induction and mediator release. Several genes studied here have not yet been appreciated as targets of TLR2-activation in the lungs before, i.e., Slpi, tenascin C, Parg and Traf1. In addition, the MALP-2 dependent induction of Tnc may indicate the existence of TLR2/6-specific pathways. PMID:21124967

  11. Response to LPS Injection after Anti-Orthostatic Hypokinesia in Rats, an Hypothesis for Endothelial Dysfunction

    NASA Astrophysics Data System (ADS)

    Navasiolava, N. M.; Pashkevich, S. G.; Custaud, M. A.; Emelianova, A. A.; Kulchitsky, V. A.

    2008-06-01

    The indirect estimation of lipopolysaccharide (LPS) translocation by measuring of IL-6 serum level after LPS injection was carried out. We found a decreased response to LPS injection as the result of previous LPS translocation in rats after head-down tilt -45° (HDT) during 7 days and in rats after the repeated injection of LPS in 7 days after the first injection. Under electron microscopy, fringe-looking protrusions in vessel lumen, disturbance of basal membrane integrity and infringement of interendothelial junctions, adhesion of leukocytes were found in arterioles of these groups of animals. So, we suppose that translocation of LPS from gut could occur in simulated weightlessness model in rats (HDT) and could be associated with endothelial dysfunction.

  12. Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction

    PubMed Central

    Czikora, Istvan; Sridhar, Supriya; Gorshkov, Boris; Alieva, Irina B.; Kasa, Anita; Gonzales, Joyce; Potapenko, Olena; Umapathy, Nagavedi S.; Pillich, Helena; Rick, Ferenc G.; Block, Norman L.; Verin, Alexander D.; Chakraborty, Trinad; Matthay, Michael A.; Schally, Andrew V.; Lucas, Rudolf

    2014-01-01

    Rationale: Antibiotic treatment of patients infected with G− or G+ bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion. Methods: Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting. Results: GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. Conclusions: GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the

  13. Revisiting the Interaction between the Chaperone Skp and Lipopolysaccharide

    PubMed Central

    Burmann, Björn M.; Holdbrook, Daniel A.; Callon, Morgane; Bond, Peter J.; Hiller, Sebastian

    2015-01-01

    The bacterial outer membrane comprises two main classes of components, lipids and membrane proteins. These nonsoluble compounds are conveyed across the aqueous periplasm along specific molecular transport routes: the lipid lipopolysaccharide (LPS) is shuttled by the Lpt system, whereas outer membrane proteins (Omps) are transported by chaperones, including the periplasmic Skp. In this study, we revisit the specificity of the chaperone-lipid interaction of Skp and LPS. High-resolution NMR spectroscopy measurements indicate that LPS interacts with Skp nonspecifically, accompanied by destabilization of the Skp trimer and similar to denaturation by the nonnatural detergent lauryldimethylamine-N-oxide (LDAO). Bioinformatic analysis of amino acid conservation, structural analysis of LPS-binding proteins, and MD simulations further confirm the absence of a specific LPS binding site on Skp, making a biological relevance of the interaction unlikely. Instead, our analysis reveals a highly conserved salt-bridge network, which likely has a role for Skp function. PMID:25809264

  14. [Biological activity of native and modified lipopolysaccharides of Pragia fontium].

    PubMed

    Varbanets', L D; Shubchyns'kyĭ, V V; Pokhyl, S I; Seĭfullina, I I; Shmatkova, N V; Samburs'kyĭ, S E

    2009-01-01

    Modified lipopolysaccharides (LPS) of Pragia fontium were obtained with germanium complexes (IV) of 2-aminobenzoylhydrazon of salicylic aldehyde (2-NH2-H2Bs), 2-hydroxybenzoylhydrazon salicylic aldehyde (2-OH-H2Bs) and nicotinoylhydrazon of salicylic aldehyde (H2Ns). The modification of LPS was confirmed by IR spectroscopy. Comparative investigations of pyrogenic activity of native and modified LPS showed, that only P. fontium 20125 LPS, modified by germanium complexes with 2-hydroxybenzoylhydrazon of salicylic aldehyde (2-OH-H2Bs) has lost the pyrogenic activity. In the homological reactions of double immunodiffusion in agar it was shown that all modified LPS unlike the native ones lose completely antigenic activity. PMID:19877414

  15. Maternal lipopolysaccharide treatment differentially affects 5-HT(2A) and mGlu2/3 receptor function in the adult male and female rat offspring.

    PubMed

    Wischhof, Lena; Irrsack, Ellen; Dietz, Frank; Koch, Michael

    2015-10-01

    Maternal infection during pregnancy increases the risk for the offspring to develop schizophrenia. However, it is still not fully understood which biochemical mechanisms are responsible for the emergence of neuropsychiatric symptoms following prenatal immune activation. The serotonin (5-hydroxytryptamine, 5-HT) and glutamate system have prominently been associated with the schizophrenia pathophysiology but also with the mechanism of antipsychotic drug actions. Here, we investigated the behavioral and cellular response to 5-HT2A and metabotropic glutamate (mGlu)2/3 receptor stimulation in male and female offspring born to lipopolysaccharide (LPS)-treated mothers. Additionally, we assessed protein expression levels of prefrontal 5-HT2A and mGlu2 receptors. Prenatally LPS-exposed male and female offspring showed locomotor hyperactivity and increased head-twitch behavior in response to the 5-HT2A receptor agonist DOI. In LPS-exposed male offspring, the mGlu2/3 receptor agonist LY379268 failed to reduce DOI-induced prepulse inhibition deficits. In LPS-males, the behavioral changes were further accompanied by enhanced DOI-induced c-Fos protein expression and an up-regulation of prefrontal 5-HT2A receptors. No changes in either 5-HT2A or mGlu2 receptor protein levels were found in female offspring. Our data support the hypothesis of an involvement of maternal infection during pregnancy contributing, at least partially, to the pathology of schizophrenia. Identifying biochemical alterations that parallel the behavioral deficits may help to improve therapeutic strategies in the treatment of this mental illness. Since most studies in rodents almost exclusively include male subjects, our data further contribute to elucidating possible gender differences in the effects of prenatal infection on 5-HT2A and mGlu2/3 receptor function. PMID:26051401

  16. Inflammatory effects of Edwardsiella ictaluri lipopolysaccharide modifications in catfish gut.

    PubMed

    Santander, Javier; Kilbourne, Jacquelyn; Park, Jie-Yeun; Martin, Taylor; Loh, Amanda; Diaz, Ignacia; Rojas, Robert; Segovia, Cristopher; DeNardo, Dale; Curtiss, Roy

    2014-08-01

    Bacterial lipopolysaccharides (LPS) are structural components of the outer membranes of Gram-negative bacteria and also are potent inducers of inflammation in mammals. Higher vertebrates are extremely sensitive to LPS, but lower vertebrates, like fish, are resistant to their systemic toxic effects. However, the effects of LPS on the fish intestinal mucosa remain unknown. Edwardsiella ictaluri is a primitive member of the Enterobacteriaceae family that causes enteric septicemia in channel catfish (Ictalurus punctatus). E. ictaluri infects and colonizes deep lymphoid tissues upon oral or immersion infection. Both gut and olfactory organs are the primary sites of invasion. At the systemic level, E. ictaluri pathogenesis is relatively well characterized, but our knowledge about E. ictaluri intestinal interaction is limited. Recently, we observed that E. ictaluri oligo-polysaccharide (O-PS) LPS mutants have differential effects on the intestinal epithelia of orally inoculated catfish. Here we evaluate the effects of E. ictaluri O-PS LPS mutants by using a novel catfish intestinal loop model and compare it to the rabbit ileal loop model inoculated with Salmonella enterica serovar Typhimurium LPS. We found evident differences in rabbit ileal loop and catfish ileal loop responses to E. ictaluri and S. Typhimurium LPS. We determined that catfish respond to E. ictaluri LPS but not to S. Typhimurium LPS. We also determined that E. ictaluri inhibits cytokine production and induces disruption of the intestinal fish epithelia in an O-PS-dependent fashion. The E. ictaluri wild type and ΔwibT LPS mutant caused intestinal tissue damage and inhibited proinflammatory cytokine synthesis, in contrast to E. ictaluri Δgne and Δugd LPS mutants. We concluded that the E. ictaluri O-PS subunits play a major role during pathogenesis, since they influence the recognition of the LPS by the intestinal mucosal immune system of the catfish. The LPS structure of E. ictaluri mutants is needed to

  17. Human monocyte CD14 is upregulated by lipopolysaccharide.

    PubMed Central

    Landmann, R; Knopf, H P; Link, S; Sansano, S; Schumann, R; Zimmerli, W

    1996-01-01

    Membrane CD14 is involved in lipopolysaccharide (LPS)-induced monocyte activation; it binds LPS, and antibodies against CD14 block the effects of low-dose LPS. It is unknown how LPS regulates its own receptor CD14 in vitro. Therefore, we investigated the effects of LPS on CD14 mRNA and membrane and soluble CD14 (mCD14 and sCD14, respectively) in human monocytes and macrophages. No changes were observed during the first 3 h of LPS stimulation. After 6 to 15 h, LPS weakly reduced CD14 mRNA and mCD14 and transiently enhanced sCD14 release. A 2-day incubation with LPS caused increases in the levels of CD14 mRNA (2-fold), mCD14 (2-fold), sCD14 (1.5-fold), and LPS-fluorescein isothiocyanate binding (1.5-fold); a 5-h incubation with LPS was sufficient to induce the late effects on mCD14 and sCD14. The maximal effect on mCD14 and sCD14 was reached with > or = 1 ng of LPS per ml; the proportional distribution of the two sCD14 isoforms was not modified by LPS. Besides rough and smooth LPS, lipid A, heat-killed Escherichia coli, lipoteichoic acid, and Staphylococcus aureus cell wall extract (10 micrograms/ml) caused similar increases of mCD14. The LPS effect was blocked by polymyxin B but not by anti-tumor necrosis factor alpha, anti-interleukin-6, anti-gamma interferon, and anti-LPS-binding protein. LPS-induced tumor necrosis factor alpha production was abolished after a second 4-h challenge. In contrast, the LPS-induced increases CD14 mRNA, mCD14, and sCD14 were stronger and appeared earlier after a second LPS challenge. In conclusion, CD14 is transcriptionally upregulated by LPS and other bacterial cell wall constituents. PMID:8613389

  18. Inhibition of Neuroinflammation in LPS-Activated Microglia by Cryptolepine.

    PubMed

    Olajide, Olumayokun A; Bhatia, Harsharan S; de Oliveira, Antonio C P; Wright, Colin W; Fiebich, Bernd L

    2013-01-01

    Cryptolepine, an indoloquinoline alkaloid in Cryptolepis sanguinolenta, has anti-inflammatory property. In this study, we aimed to evaluate the effects of cryptolepine on lipopolysaccharide (LPS)- induced neuroinflammation in rat microglia and its potential mechanisms. Microglial activation was induced by stimulation with LPS, and the effects of cryptolepine pretreatment on microglial activation and production of proinflammatory mediators, PGE2/COX-2, microsomal prostaglandin E2 synthase and nitric oxide/iNOS were investigated. We further elucidated the role of Nuclear Factor-kappa B (NF- κ B) and the mitogen-activated protein kinases in the antiinflammatory actions of cryptolepine in LPS-stimulated microglia. Our results showed that cryptolepine significantly inhibited LPS-induced production of tumour necrosis factor-alpha (TNF α ), interleukin-6 (IL-6), interleukin-1beta (IL-1 β ), nitric oxide, and PGE2. Protein and mRNA levels of COX-2 and iNOS were also attenuated by cryptolepine. Further experiments on intracellular signalling mechanisms show that I κ B-independent inhibition of NF- κ B nuclear translocation contributes to the anti-neuroinflammatory actions of cryptolepine. Results also show that cryptolepine inhibited LPS-induced p38 and MAPKAPK2 phosphorylation in the microglia. Cell viability experiments revealed that cryptolepine (2.5 and 5  μ M) did not produce cytotoxicity in microglia. Taken together, our results suggest that cryptolepine inhibits LPS-induced microglial inflammation by partial targeting of NF- κ B signalling and attenuation of p38/MAPKAPK2. PMID:23737832

  19. Analysis of bypass activation of C3 by endotoxic LPS and loss of this potency

    PubMed Central

    Dierich, M. P.; Bitter-Suermann, D.; König, W.; Hadding, U.; Galanos, C.; Rietschel, E. T.

    1973-01-01

    Endotoxic lipopolysaccharides prepared from Salmonella minnesota smooth form (LPS-S) and rough form, R 595 (LPS-R) activate C3 in guinea-pig serum as is demonstrated by C3 kinetics and generation of anaphylatoxic activity. The activation depends on the presence of certain serum factors, one of which is the protein (SF) interacting with the cobra venom factor, on the presence of Mg++, the temperature and on dose of LPS applied. This turnover of C3 is terminated at 37° within 2 minutes (LPS-R) to 12 minutes (LPS-S) and then reaches a plateau. The amount of C3 consumption, i.e. the level of the plateau, is typical for given concentrations of LPS-S and LPS-R (intermediate plateau). Above a certain LPS-concentration additional LPS does not induce further C3 turnover (maximal plateau). While the `maximal plateau' may be explained by a limitation of the factors needed for the LPS dependent consumption of C3, the `intermediate plateau' and the termination of the action on C3 are not well understood. It is hypothesized that coating of the LPS molecule by serum protein, e.g. albumin, inactivates LPS-S and LPS-R with regard to their action on C3. C3 and C5 in normal serum concentrations appear not to be involved. It is suggested that an additional mechanism for termination of LPS action is a rapid loss of activity of LPS-induced intermediates. ImagesFIG. 8 PMID:4122408

  20. Deacylated lipopolysaccharides inhibit biofilm formation by Gram-negative bacteria.

    PubMed

    Lee, Kyung-Jo; Lee, Mi-Ae; Hwang, Won; Park, Hana; Lee, Kyu-Ho

    2016-08-01

    The extracellular polysaccharides of Vibrio vulnificus play different roles during biofilm development. Among them, the effect of lipopolysaccharide (LPS), which is crucial for bacterial adherence to surfaces during the initial stage of biofilm formation, on the formation process was examined using various types of LPS extracts. Exogenously added LPS strongly inhibited biofilm formation in a dose-dependent manner. In addition, the exogenous addition of a deacylated form of LPS (dLPS) also inhibited biofilm formation. However, an LPS fraction extracted from a mutant not able to produce O-antigen polysaccharides (O-Ag) did not have an inhibitory effect. Furthermore, biofilm formation by several Gram-negative bacteria was inhibited by dLPS addition. In contrast, biofilm formation by Gram-positive bacteria was not influenced by dLPS but was affected by lipoteichoic acid. Therefore, this study demonstrates that O-Ag in LPS is important for inhibiting biofilm formation and may serve an efficient anti-biofilm agent specific for Gram-negative bacteria. PMID:27294580

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

    SciTech Connect

    Henning, Maria Florencia; Sanchez, Susana; Bakas, Laura

    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.

  2. Innate immunity probed by lipopolysaccharides affinity strategy and proteomics.

    PubMed

    Giangrande, Chiara; Colarusso, Lucia; Lanzetta, Rosa; Molinaro, Antonio; Pucci, Piero; Amoresano, Angela

    2013-01-01

    Lipopolysaccharides (LPSs) are ubiquitous and vital components of the cell surface of Gram-negative bacteria that have been shown to play a relevant role in the induction of the immune-system response. In animal and plant cells, innate immune defenses toward microorganisms are triggered by the perception of pathogen associated molecular patterns. These are conserved and generally indispensable microbial structures such as LPSs that are fundamental in the Gram-negative immunity recognition. This paper reports the development of an integrated strategy based on lipopolysaccharide affinity methodology that represents a new starting point to elucidate the molecular mechanisms elicited by bacterial LPS and involved in the different steps of innate immunity response. Biotin-tagged LPS was immobilized on streptavidin column and used as a bait in an affinity capture procedure to identify protein partners from human serum specifically interacting with this effector. The complex proteins/lipopolysaccharide was isolated and the protein partners were fractionated by gel electrophoresis and identified by mass spectrometry. This procedure proved to be very effective in specifically binding proteins functionally correlated with the biological role of LPS. Proteins specifically bound to LPS essentially gathered within two functional groups, regulation of the complement system (factor H, C4b, C4BP, and alpha 2 macroglobulin) and inhibition of LPS-induced inflammation (HRG and Apolipoproteins). The reported strategy might have important applications in the elucidation of biological mechanisms involved in the LPSs-mediated molecular recognition and anti-infection responses. PMID:22752448

  3. Lipopolysaccharide enhances FcεRI-mediated mast cell degranulation by increasing Ca2+ entry through store-operated Ca2+ channels: implications for lipopolysaccharide exacerbating allergic asthma.

    PubMed

    Yang, Chengbin; Mo, Xucheng; Lv, Jingzhang; Liu, Xiaoyu; Yuan, Meichun; Dong, Ming; Li, Li; Luo, Xinping; Fan, Xinmin; Jin, Zhe; Liu, Zhigang; Liu, Jie

    2012-12-01

    Lipopolysaccharide (LPS) can exacerbate asthma; however, the mechanisms are not fully understood. This study investigated the effect of LPS on antigen-stimulated mast cell degranulation and the underlying mechanisms. We found that LPS enhanced degranulation in RBL-2H3 cells and mouse peritoneal mast cells upon FcεRI activation, in a dose- and time-dependent manner. Parallel to the alteration of degranulation, LPS increased FcεRI-activated Ca(2+) mobilization, as well as Ca(2+) entry through store-operated calcium channels (SOCs) evoked by thapsigargin. Blocking Ca(2+) entry through SOCs completely abolished LPS enhancement of mast cell degranulation. Consistent with functional alteration of SOCs, LPS increased mRNA and protein levels of Orai1 and STIM1, two major subunits of SOCs, in a time-dependent manner. In addition, LPS increased the mRNA level of Toll-like receptor 4 (TLR4) in a time-dependent manner. Blocking TLR4 with Cli-095 inhibited LPS, increasing transcription and expression of SOC subunits. Concomitantly, the effect of LPS enhancement of Ca(2+) mobilization and mast cell degranulation was largely reduced by Cli-095. Administration of LPS (1 μg) in vivo aggravated airway hyperreactivity and inflammatory reactions in allergic asthmatic mice. Histamine levels in serum and bronchoalveolar lavage fluid were increased by LPS treatment. In addition, Ca(2+) mobilization was enhanced in peritoneal mast cells isolated from LPS-treated asthmatic mice. Taken together, these results imply that LPS enhances mast cell degranulation, which potentially contributes to LPS exacerbating allergic asthma. Lipopolysaccharide increases Ca(2+) entry through SOCs by upregulating transcription and expression of SOC subunits, mainly through interacting with TLR4 in mast cells, resulting in enhancement of mast cell degranulation upon antigen stimulation. PMID:22581748

  4. Thermo-nanoimprinted biomimetic probe for LPS and LTA immunosensing.

    PubMed

    Buchegger, Patricia; Lieberzeit, Peter A; Preininger, Claudia

    2014-02-01

    A complex prepolymerized film comprising monomers, cross-linkers, and initiator is usually used to create molecularly imprinted polymers. We herein exploit ready-to-use resist materials and link molecular surface imprinting with UV- and thermo-nanoimprinting techniques to create a sensor layer for the specific recognition of the bacterial surface markers lipopolysaccharide (LPS) and lipoteichoic acid (LTA). To account for the highly polar moieties of LPS and LTA, we evaluate different resist and stamp materials of distinct surface properties by AFM and molecularly imprinted sorbent assays. Thermo nanoimprinting of LPS and LTA micelles to Epon 1002F films exhibits excellent sensitivity of up to 13 times increased signals compared to those of the nonimprinted films and negligible cross-reaction with the tested nonspecific analyte. Additionally, the sensitivity and selectivity of the thermo nanoimprints is compared to conventional molecular surface imprints using a cocktail of acrylic monomers in QCM measurements. PMID:24392724

  5. The effects of Nigella sativa on sickness behavior induced by lipopolysaccharide in male Wistar rats

    PubMed Central

    Norouzi, Fatemeh; Abareshi, Azam; Anaeigoudari, Akbar; Shafei, Mohammad Naser; Gholamnezhad, Zahra; Saeedjalali, Mohsen; Mohebbati, Reza; Hosseini, Mahmoud

    2016-01-01

    Objective: Neuroimmune factors contribute on the pathogenesis of sickness behaviors. Nigella sativa (NS) has anti-inflammatory, anti-anxiety and anti-depressive effects. In the present study, the effect of NS hydro-alcoholic extract on sickness behavior induced by lipopolysaccharide (LPS) was investigated. Materials and Methods: The rats were divided into five groups (n=10 in each): (1) control (saline), (2) LPS (1 mg/kg, administered two hours before behavioral tests), (3-5) LPS-Nigella sativa 100 , 200 and 400 mg/kg (LPS-NS 100, LPS-NS 200 and LPS-NS 400, respectively). Open- field (OF), elevated plus maze (EPM) and forced swimming test (FST) were performed. Results: In OF, LPS reduced the peripheral crossing, peripheral distance, total crossing and total distance compared to control (p<0.01- p<0.001). The central crossing, central distance and central time in LPS-NS 100, LPS-NS200 and LPS-NS 400 groups were higher than LPS (p<0.01- p<0.001). In EPM, LPS decreased the open arm entries, open arm time and closed arm entries while increased the closed time compared to control (p<0.001). Pretreatment by NS extract reversed the effects of LPS (p<0.05- p<0.001). In FST, LPS increased the immobility time while, decreased the climbing and active times compared to control (p<0.05- p<0.001). In LPS-NS 100, LPS-NS 200 and LPS-NS 400 groups the immobility time was less while, the active and climbing times were more than those of LPS (p<0.05- p<0.001). Conclusion: The results of the present study showed that the hydro-alcoholic extract of NS reduced the LPS-induced sickness behaviors in rats. Further investigations are required for better understanding the responsible compound (s) and the underlying mechanism(s). PMID:27247927

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Lipopolysaccharide Sequestrants: Structural Correlates of Activity and Toxicity in Novel Acylhomospermines

    PubMed Central

    Miller, Kelly A.; Kumar, E.V.K. Suresh; Wood, Stewart J.; Cromer, Jens R.; Datta, Apurba; David*, Sunil A.

    2005-01-01

    Lipopolysaccharides (LPS), otherwise termed ‘endotoxins’, are outer-membrane constituents of Gram-negative bacteria. Lipopolysaccharides play a key role in the pathogenesis of ‘Septic Shock’, a major cause of mortality in the critically ill patient. Therapeutic options aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide do not exist at the present time. We have defined the pharmacophore necessary for small molecules to specifically bind and neutralize LPS and, using animal models of sepsis, have shown that the sequestration of circulatory LPS by small molecules is a therapeutically viable strategy. In this paper, the interactions of a series of acylated homologated spermine compounds with lipopolysaccharide (LPS) have been characterized. The optimal acyl chain length for effective sequestration of LPS was identified to be C16 for the mono-acyl compounds. The most promising of these compounds, 4e, binds LPS with an ED50 of 1.37 μM. Nitric oxide production in murine J774A.1 cells, as well as TNF-α in human blood, are inhibited in a dose-dependent manner by 4e at concentrations orders of magnitude lower than toxic doses. Administration of 4e to d-galactosamine-sensitized mice challenged with supralethal doses of LPS provided significant protection against lethality. Potent anti-endotoxic activity, low toxicity, and ease of synthesis render this class of compounds candidate endotoxin-sequestering agents of potential significant therapeutic value. PMID:15801849

  8. Lipopolysaccharide binding protein enhances the responsiveness of alveolar macrophages to bacterial lipopolysaccharide. Implications for cytokine production in normal and injured lungs.

    PubMed Central

    Martin, T R; Mathison, J C; Tobias, P S; Letúrcq, D J; Moriarty, A M; Maunder, R J; Ulevitch, R J

    1992-01-01

    A plasma lipopolysaccharide (LPS)-binding protein (LBP) has been shown to regulate the response of rabbit peritoneal macrophages and human blood monocytes to endotoxin (LPS). We investigated whether LBP is present in lung fluids and the effects of LBP on the response of lung macrophages to LPS. Immunoreactive LBP was detectable in the lavage fluids of patients with the adult respiratory distress syndrome by immunoprecipitation followed by Western blotting, and also by specific immunoassay. In rabbits, the LBP appeared to originate outside of the lungs, inasmuch as mRNA transcripts for LBP were identified in total cellular RNA from liver, but not from lung homogenates or alveolar macrophages. Purified LBP enhanced the response of human and rabbit alveolar macrophages to both smooth form LPS (Escherichia coli O111B:4) and rough form LPS (Salmonella minnesota Re595). In the presence of LBP and LPS, the onset of tumor necrosis factor-alpha (TNF alpha) production occurred earlier and at an LPS threshold dose that was as much as 1,000-fold lower for both types of LPS. In rabbit alveolar macrophages treated with LBP and LPS, TNF alpha mRNA appeared earlier, reached higher levels, and had a prolonged half-life as compared with LPS treatment alone. Neither LPS nor LPS and LBP affected pHi or [Cai++] in alveolar macrophages. Specific monoclonal antibodies to CD14, a receptor that binds LPS/LBP complexes, inhibited TNF alpha production by human alveolar macrophages stimulated with LPS alone or with LPS/LBP complexes, indicating the importance of CD14 in mediating the effects of LPS on alveolar macrophages. Thus, immunoreactive LBP accumulates in lung lavage fluids in patients with lung injury and enhances LPS-stimulated TNF alpha gene expression in alveolar macrophages by a pathway that depends on the CD14 receptor. LBP may play an important role in augmenting TNF alpha expression by alveolar macrophages within the lungs. Images PMID:1281827

  9. DSP30 enhances the immunosuppressive properties of mesenchymal stromal cells and protects their suppressive potential from lipopolysaccharide effects: A potential role of adenosine.

    PubMed

    Sangiorgi, Bruno; De Freitas, Helder Teixeira; Schiavinato, Josiane Lilian Dos Santos; Leão, Vitor; Haddad, Rodrigo; Orellana, Maristela Delgado; Faça, Vitor Marcel; Ferreira, Germano Aguiar; Covas, Dimas Tadeu; Zago, Marco Antônio; Panepucci, Rodrigo Alexandre

    2016-07-01

    Multipotent mesenchymal stromal cells (MSC) are imbued with an immunosuppressive phenotype that extends to several immune system cells. In this study, we evaluated how distinct Toll-like receptor (TLR) agonists impact immunosuppressive properties of bone marrow (BM)-MSC and explored the potential mechanisms involved. We show that TLR4 stimulation by lipopolysaccharide (LPS) restricted the ability of MSC to suppress the proliferation of T lymphocytes, increasing the gene expression of interleukin (IL)-1β and IL-6. In contrast, stimulation of TLR9 by DSP30 induced proliferation and the suppressive potential of BM-MSC, coinciding with reducing tumor necrosis factor (TNF)-α expression, increased expression of transforming growth factor (TGF)-β1, increased percentages of BM-MSC double positive for the ectonucleotidases CD39+CD73+ and adenosine levels. Importantly, following simultaneous stimulation with LPS and DSP30, BM-MSC's ability to suppress T lymphocyte proliferation was comparable with that of non-stimulated BM-MSC levels. Moreover, stimulation of BM-MSC with LPS reduced significantly the gene expression levels, on co-cultured T lymphocyte, of IL-10 and interferon (IFN)γ, a cytokine with potential to enhance the immunosuppression mediated by MSC and ameliorate the clinical outcome of patients with graft-versus-host disease (GVHD). Altogether, our findings reiterate the harmful effects of LPS on MSC immunosuppression, besides indicating that DSP30 could provide a protective effect against LPS circulating in the blood of GVHD patients who receive BM-MSC infusions, ensuring a more predictable immunosuppressive effect. The novel effects and potential mechanisms following the stimulation of BM-MSC by DSP30 might impact their clinical use, by allowing the derivation of optimal "licensing" protocols for obtaining therapeutically efficient MSC. PMID:27260206

  10. Titanium particles and surface-bound LPS activate different pathways in IC-21 macrophages.

    PubMed

    Schwab, Luciana P; Xing, Zhiqing; Hasty, Karen A; Smith, Richard A

    2006-10-01

    It is still unknown if wear-debris particles themselves induce osteolysis or if they serve a functional role as receptors for ligands that incite an inflammatory response that ultimately leads to bone resorption. In this study, commercially pure titanium particles (cpTi) were subjected to a serial combination of different cleaning methods to remove Lipopolysaccharide (LPS) or were incubated in LPS solutions of known concentrations. Then, the response of the macrophage cell line IC-21 to the cleaned particles, LPS-bound Ti particles, and soluble LPS was examined. It was found that cleaned particles up to 1000 particles per cell did not stimulate macrophages to release Tumor necrosis factor-alpha (TNF-alpha) or Interleukin 6 (IL-6), but they significantly increased the release of Prostaglandin E(2) (PGE(2)) when the particle concentration was higher than 500 particles per cell. At one particle per cell, Ti particles bound with LPS stimulated the release of IL-6 and TNF-alpha by macrophages. The level of released cytokines was dependent on, and correlated with, the amount of LPS present on the particles. The macrophages were more sensitive to soluble LPS than to particle-bound LPS, and the simultaneous addition of cleaned Ti particles did not have additional effects on the effects of soluble LPS. This study shows evidence that, cpTi particles and LPS have distinct mechanisms of action on the IC-21 macrophages, but that both contribute to the development of an inflammatory response. PMID:16544307

  11. T4 Phage Tail Adhesin Gp12 Counteracts LPS-Induced Inflammation In Vivo.

    PubMed

    Miernikiewicz, Paulina; Kłopot, Anna; Soluch, Ryszard; Szkuta, Piotr; Kęska, Weronika; Hodyra-Stefaniak, Katarzyna; Konopka, Agnieszka; Nowak, Marcin; Lecion, Dorota; Kaźmierczak, Zuzanna; Majewska, Joanna; Harhala, Marek; Górski, Andrzej; Dąbrowska, Krystyna

    2016-01-01

    Bacteriophages that infect Gram-negative bacteria often bind to the bacterial surface by interaction of specific proteins with lipopolysaccharide (LPS). Short tail fiber proteins (tail adhesin, gp12) mediate adsorption of T4-like bacteriophages to Escherichia coli, binding surface proteins or LPS. Produced as a recombinant protein, gp12 retains its ability to bind LPS. Since LPS is able to exert a major impact on the immune response in animals and in humans, we have tested LPS-binding phage protein gp12 as a potential modulator of the LPS-induced immune response. We have produced tail adhesin gp12 in a bacterial expression system and confirmed its ability to form trimers and to bind LPS in vitro by dynamic light scattering. This product had no negative effect on mammalian cell proliferation in vitro. Further, no harmful effects of this protein were observed in mice. Thus, gp12 was used in combination with LPS in a murine model, and it decreased the inflammatory response to LPS in vivo, as assessed by serum levels of cytokines IL-1 alpha and IL-6 and by histopathological analysis of spleen, liver, kidney and lungs. Thus, in future studies gp12 may be considered as a potential tool for modulating and specifically for counteracting LPS-related physiological effects in vivo. PMID:27471503

  12. T4 Phage Tail Adhesin Gp12 Counteracts LPS-Induced Inflammation In Vivo

    PubMed Central

    Miernikiewicz, Paulina; Kłopot, Anna; Soluch, Ryszard; Szkuta, Piotr; Kęska, Weronika; Hodyra-Stefaniak, Katarzyna; Konopka, Agnieszka; Nowak, Marcin; Lecion, Dorota; Kaźmierczak, Zuzanna; Majewska, Joanna; Harhala, Marek; Górski, Andrzej; Dąbrowska, Krystyna

    2016-01-01

    Bacteriophages that infect Gram-negative bacteria often bind to the bacterial surface by interaction of specific proteins with lipopolysaccharide (LPS). Short tail fiber proteins (tail adhesin, gp12) mediate adsorption of T4-like bacteriophages to Escherichia coli, binding surface proteins or LPS. Produced as a recombinant protein, gp12 retains its ability to bind LPS. Since LPS is able to exert a major impact on the immune response in animals and in humans, we have tested LPS-binding phage protein gp12 as a potential modulator of the LPS-induced immune response. We have produced tail adhesin gp12 in a bacterial expression system and confirmed its ability to form trimers and to bind LPS in vitro by dynamic light scattering. This product had no negative effect on mammalian cell proliferation in vitro. Further, no harmful effects of this protein were observed in mice. Thus, gp12 was used in combination with LPS in a murine model, and it decreased the inflammatory response to LPS in vivo, as assessed by serum levels of cytokines IL-1 alpha and IL-6 and by histopathological analysis of spleen, liver, kidney and lungs. Thus, in future studies gp12 may be considered as a potential tool for modulating and specifically for counteracting LPS-related physiological effects in vivo. PMID:27471503

  13. LPS priming potentiates and prolongs proinflammatory cytokine response to the trichothecene deoxynivalenol in the mouse

    SciTech Connect

    Islam, Zahidul; Pestka, James J. . E-mail: pestka@msu.edu

    2006-02-15

    Simultaneous exposure to lipopolysaccharide (LPS) markedly amplifies induction of proinflammatory cytokine expression as well as IL-1-driven lymphocyte apoptosis by trichothecene deoxynivalenol (DON) in the mouse. The purpose of this research was to test the hypothesis that LPS priming will sensitize a host to DON-induced proinflammatory cytokine induction and apoptosis. In mice primed with LPS (1 mg/kg bw) ip. and treated 8 h later with DON po., the minimum DON doses for inducing IL-1{alpha}, IL-1{beta}, IL-6 and TNF-{alpha} serum proteins and splenic mRNAs were significantly lower than the DON doses required for vehicle-primed mice. LPS priming also decreased onset time and dramatically increased magnitude and duration of cytokine responses. LPS-primed mice maintained heightened sensitivity to DON for up to 24 h. LPS priming doses as low as 50 {mu}g/kg bw evoked sensitization. DNA fragmentation analysis and flow cytometry also revealed that mice primed with LPS (1 mg/kg) for 8 h and exposed to DON (12.5 mg/kg) exhibited massive thymocyte loss by apoptosis 12 h later compared to mice exposed to DON or LPS alone. LPS priming decreased DON-induced p38 and ERK 1/2 phosphorylation suggesting that enhanced mitogen-activated protein kinase activation was not involved in increased cytokine responses. Taken together, exposure to LPS rendered mice highly susceptible to DON induction of cytokine expression and this correlated with increased apoptosis in the thymus.

  14. The Genetic and Molecular Basis of O-Antigenic Diversity in Burkholderia pseudomallei Lipopolysaccharide

    PubMed Central

    Tuanyok, Apichai; Stone, Joshua K.; Mayo, Mark; Kaestli, Mirjam; Gruendike, Jeffrey; Georgia, Shalamar; Warrington, Stephanie; Mullins, Travis; Allender, Christopher J.; Wagner, David M.; Chantratita, Narisara; Peacock, Sharon J.; Currie, Bart J.; Keim, Paul

    2012-01-01

    Lipopolysaccharide (LPS) is one of the most important virulence and antigenic components of Burkholderia pseudomallei, the causative agent of melioidosis. LPS diversity in B. pseudomallei has been described as typical, atypical or rough, based upon banding patterns on SDS-PAGE. Here, we studied the genetic and molecular basis of these phenotypic differences. Bioinformatics was used to determine the diversity of genes known or predicted to be involved in biosynthesis of the O-antigenic moiety of LPS in B. pseudomallei and its near-relative species. Multiplex-PCR assays were developed to target diversity of the O-antigen biosynthesis gene patterns or LPS genotypes in B. pseudomallei populations. We found that the typical LPS genotype (LPS genotype A) was highly prevalent in strains from Thailand and other countries in Southeast Asia, whereas the atypical LPS genotype (LPS genotype B) was most often detected in Australian strains (∼13.8%). In addition, we report a novel LPS ladder pattern, a derivative of the atypical LPS phenotype, associated with an uncommon O-antigen biosynthesis gene cluster that is found in only a small B. pseudomallei sub-population. This new LPS group was designated as genotype B2. We also report natural mutations in the O-antigen biosynthesis genes that potentially cause the rough LPS phenotype. We postulate that the diversity of LPS may correlate with differential immunopathogenicity and virulence among B. pseudomallei strains. PMID:22235357

  15. Lipopolysaccharide-induced memory impairment in rats is preventable using 7-nitroindazole.

    PubMed

    Anaeigoudari, Akbar; Shafei, Mohammad Naser; Soukhtanloo, Mohammad; Sadeghnia, Hamid Reza; Reisi, Parham; Beheshti, Farimah; Mohebbati, Reza; Mousavi, Seyed Mojtaba; Hosseini, Mahmoud

    2015-09-01

    Inflammation and oxidative stress have important roles in memory impairment. The effect of 7-nitroindazole (7NI) on lipopolysaccharide (LPS)-induced memory impairment was investigated. Rats were used, divided into four groups that were treated as follows: (1) control (saline); (2) LPS; (3) 7NI-LPS; and (4) 7NI before passive avoidance (PA). In the LPS group, the latency for entering the dark compartment was shorter than in the controls (p < 0.01 and p < 0.001); while in the 7NI-LPS group, it was longer than in the LPS group (p < 0.01 and p < 0.001). Malondialdehyde (MDA) and nitric oxide (NO) metabolite concentrations in the brain tissues of the LPS group were higher than in the controls (p < 0.001 and p < 0.05); while in the 7NI-LPS group, they were lower than in the LPS group (p < 0.001 and p < 0.05, respectively). The thiol content in the brain of the LPS group was lower than in the controls (p < 0.001); while in the 7NI-LPS group, it was higher than in the LPS group (p < 0.001). It is suggested that brain tissue oxidative damage and NO elevation have a role in the deleterious effects of LPS on memory retention that are preventable using 7NI. PMID:26352498

  16. Morphological damage induced by Escherichia coli lipopolysaccharide in cultured hepatocytes: localization and binding properties.

    PubMed Central

    Pagani, R.; Portolés, M. T.; Díaz-Laviada, I.; Municio, A. M.

    1988-01-01

    Lipopolysaccharides (LPS) from Gram-negative bacteria are considered to be the responsible agents for the induction of endotoxic shock, affecting the liver as a target organ. In this study, the cell morphology and some biochemical properties of 24 h-culture-hepatocyte monolayers treated with Escherichia coli 0111:B4 lipopolysaccharide, were observed. Cell morphology was observed by scanning electron microscopy and immunofluorescence methods. LPS interaction induced an increase in rounded cells with diminished adhesion capacity. As biochemical parameters, albumin synthesis and 2-deoxyglucose uptake were measured. LPS decreased the hexose uptake in a dose-dependent manner. Binding of (14C)LPS to cultured hepatocytes showed that LPS binds to non-specific constituents of the membrane bilayer. Images Fig. 1 Fig. 2 Fig. 3 Fig. 7 PMID:3052562

  17. A lectin S-domain receptor kinase mediates lipopolysaccharide sensing in Arabidopsis thaliana.

    PubMed

    Ranf, Stefanie; Gisch, Nicolas; Schäffer, Milena; Illig, Tina; Westphal, Lore; Knirel, Yuriy A; Sánchez-Carballo, Patricia M; Zähringer, Ulrich; Hückelhoven, Ralph; Lee, Justin; Scheel, Dierk

    2015-04-01

    The sensing of microbe-associated molecular patterns (MAMPs) triggers innate immunity in animals and plants. Lipopolysaccharide (LPS) from Gram-negative bacteria is a potent MAMP for mammals, with the lipid A moiety activating proinflammatory responses via Toll-like receptor 4 (TLR4). Here we found that the plant Arabidopsis thaliana specifically sensed LPS of Pseudomonas and Xanthomonas. We isolated LPS-insensitive mutants defective in the bulb-type lectin S-domain-1 receptor-like kinase LORE (SD1-29), which were hypersusceptible to infection with Pseudomonas syringae. Targeted chemical degradation of LPS from Pseudomonas species suggested that LORE detected mainly the lipid A moiety of LPS. LORE conferred sensitivity to LPS onto tobacco after transient expression, which demonstrated a key function in LPS sensing and indicated the possibility of engineering resistance to bacteria in crop species. PMID:25729922

  18. Participation of α2 -adrenoceptors in sodium appetite inhibition during sickness behaviour following administration of lipopolysaccharide.

    PubMed

    De Luca, Laurival A; Almeida, Roberto L; David, Richard B; de Paula, Patricia M; Andrade, Carina A F; Menani, José V

    2016-03-15

    Sickness behaviour, a syndrome characterized by a general reduction in animal activity, is part of the active-phase response to fight infection. Lipopolysaccharide (LPS), an effective endotoxin to model sickness behaviour, reduces thirst and sodium excretion, and increases neurohypophysial secretion. Here we review the effects of LPS on thirst and sodium appetite. Altered renal function and hydromineral fluid intake in response to LPS occur in the context of behavioural reorganization, which manifests itself as part of the syndrome. Recent data show that, in addition to its classical effect on thirst, non-septic doses of LPS injected intraperitoneally produce a preferential inhibition of intracellular thirst versus extracellular thirst. Moreover, LPS also reduced hypertonic NaCl intake in sodium-depleted rats that entered a sodium appetite test. Antagonism of α2 -adrenoceptors abolished the effect of LPS on sodium appetite. LPS and cytokine transduction potentially recruit brain noradrenaline and α2 -adrenoceptors to control sodium appetite and sickness behaviour. PMID:26036817

  19. Meningococcal lipopolysaccharides: virulence factor and potential vaccine component.

    PubMed Central

    Verheul, A F; Snippe, H; Poolman, J T

    1993-01-01

    Lipopolysaccharides (LPS) are surface components of the outer membrane of Neisseria meningitidis. Today, 12 different types of meningococcal LPS (immunotypes) are known, of which 3 are prevalent in the western world. The differences between these immunotypes are in the oligosaccharide part of the LPS molecule and consist of small differences in the oligosaccharide structure, the amount and location of phosphoethanolamine groups, and the degree of O acetylation of individual monosaccharides. Although the differences between the various immunotypes are small, they have a profound influence on the immunochemical and immunological properties of these molecules. Furthermore, each individual strain synthesizes a number of different LPS molecules. The expression of the various components (protective epitopes) is influenced by growth conditions and growth phase. Meningococci can endogenously sialyate their LPS, which constitutes one of the mechanisms by which N. meningitidis can evade the response of the human host. Meningococcal LPS play a key role in the induction of septic shock and can probably enhance the invasiveness of meningococcal strains and shield protective epitopes. Therefore, incorporation of (detoxified) LPS or oligosaccharide components derived therefrom might be very beneficial for the efficacy of a vaccine against group B meningococci. An overview of the development of vaccines against group B meningococci is given, and the status and potential of meningococcal LPS-derived (synthetic) oligosaccharide-protein conjugate vaccines are discussed. PMID:8464406

  20. Allergen immunotherapy with nanoparticles containing lipopolysaccharide from Brucella ovis.

    PubMed

    Gómez, Sara; Gamazo, Carlos; San Roman, Beatriz; Ferrer, Marta; Sanz, Maria Luisa; Espuelas, Socorro; Irache, Juan M

    2008-11-01

    The adjuvant and protective capacity against anaphylactic shock of the association between rough lipopolysaccharide of Brucella ovis (LPS) coencapsulated with ovalbumin (OVA), as a model allergen, in Gantrez AN nanoparticles was investigated. Several strategies were performed in order to study the adjuvant effect of the LPS either encapsulated or coating the nanoparticles. OVA, as well as LPS, was incorporated either during the manufacturing process (OVA-encapsulated or LPS-encapsulated nanoparticles, respectively) or after the preparation (OVA-coated or LPS-coated nanoparticles, respectively). After the administration of 10 microg of OVA incorporated in the different formulations, all the nanoparticles, with or without LPS, were capable of amplifying the immune response (IgG(1) and IgG(2a)). However, in a model of sensitized mice to OVA, the formulation with OVA and LPS-entrapped inside the nanoparticles administered intradermally in three doses of 3 microg of OVA each was the only treatment that totally protected the mice from death after a challenge with an intraperitoneal injection of OVA. In contrast, the control group administered with OVA adsorbed onto a commercial alhydrogel adjuvant showed 80% mortality. These results are highly suggestive for the valuable use of Gantrez nanoparticles combined with rough LPS of B. ovis in immunotherapy. PMID:18582571

  1. Human CAP18: a novel antimicrobial lipopolysaccharide-binding protein.

    PubMed Central

    Larrick, J W; Hirata, M; Balint, R F; Lee, J; Zhong, J; Wright, S C

    1995-01-01

    CAP18 (18-kDa cationic antimicrobial protein) is a protein originally identified and purified from rabbit leukocytes on the basis of its capacity to bind and inhibit various activities of lipopolysaccharide (LPS). Here we report the cloning of human CAP18 and characterize the anti-LPS activity of the C-terminal fragment. Oligonucleotide probes designed from the rabbit CAP18 cDNA were used to identify human CAP18 from a bone marrow cDNA library. The cDNA encodes a protein composed of a 30-amino-acid signal peptide, a 103-amino-acid N-terminal domain of unknown function, and a C-terminal domain of 37 amino acids homologous to the LPS-binding antimicrobial domain of rabbit CAP18, designated CAP18(104-140). A human CAP18-specific antiserum was generated by using CAP18 expressed as a fusion protein with the maltose-binding protein. Western blots (immunoblots) with this antiserum showed specific expression of human CAP18 in granulocytes. Synthetic human CAP18(104-140) and a more active truncated fragment, CAP18(104-135), were shown to (i) bind to erythrocytes coated with diverse strains of LPS, (ii) inhibit LPS-induced release of nitric oxide from macrophages, (iii) inhibit LPS-induced generation of tissue factor, and (iv) protect mice from LPS lethality. CAP18(104-140) may have therapeutic utility for conditions associated with elevated concentrations of LPS. PMID:7890387

  2. Antioxidant Effects of Cranberry Powder in Lipopolysaccharide Treated Hypercholesterolemic Rats

    PubMed Central

    Kim, Mi Joung; Kim, Jung Hee; Kwak, Ho-Kyung

    2014-01-01

    This study was conducted to investigate the effects of cranberry power on antioxidant defense system in rats fed an atherogenic diet and injected with lipopolysaccharide (LPS). Sprague-Dawley rats were divided into the following 5 groups: normal diet+saline (NS), atherogenic diet+saline (AS), atherogenic diet+LPS (AL), atherogenic diet with 5% cranberry powder+LPS (AL-C5), and atherogenic diet with 10% cranberry powder+LPS (AL-C10). Total antioxidant status measured by ferric reducing ability of plasma (FRAP) was significantly reduced by LPS injection (24%) and was restored by the cranberry powder treatment (P<0.05). In addition, the mean level of plasma total phenolics was significantly decreased by LPS injection (P<0.05) and tended to be increased when cranberry powder was incorporated in to the diet. Activity of serum superoxide dismutase (SOD) tended to be lowered by LPS injection and declined further in cranberry powder fortified groups. Overall results indicate that dietary cranberry powder may provide appropriate antioxidants to counter the diminished antioxidant status induced by exposing hypercholesterolemic rats to LPS. PMID:25054105

  3. Micheliolide inhibits LPS-induced inflammatory response and protects mice from LPS challenge

    PubMed Central

    Qin, Xiangyang; Jiang, Xinru; Jiang, Xin; Wang, Yuli; Miao, Zhulei; He, Weigang; Yang, Guizhen; Lv, Zhenhui; Yu, Yizhi; Zheng, Yuejuan

    2016-01-01

    Sepsis is the principal cause of fatality in the intensive care units worldwide. It involves uncontrolled inflammatory response resulting in multi-organ failure and even death. Micheliolide (MCL), a sesquiterpene lactone, was reported to inhibit dextran sodium sulphate (DSS)-induced inflammatory intestinal disease, colitis-associated cancer and rheumatic arthritis. Nevertheless, the role of MCL in microbial infection and sepsis is unclear. We demonstrated that MCL decreased lipopolysaccharide (LPS, the main cell wall component of Gram-negative bacteria)-mediated production of cytokines (IL-6, TNF-α, MCP-1, etc) in Raw264.7 cells, primary macrophages, dendritic cells and human monocytes. MCL plays an anti-inflammatory role by inhibiting LPS-induced activation of NF-κB and PI3K/Akt/p70S6K pathways. It has negligible impact on the activation of mitogen-activated protein kinase (MAPK) pathways. In the acute peritonitis mouse model, MCL reduced the secretion of IL-6, TNF-α, IL-1β, MCP-1, IFN-β and IL-10 in sera, and ameliorated lung and liver damage. MCL down-regulated the high mortality rate caused by lethal LPS challenge. Collectively, our data illustrated that MCL enabled maintenance of immune equilibrium may represent a potentially new anti-inflammatory and immunosuppressive drug candidate in the treatment of sepsis and septic shock. PMID:26984741

  4. Inhibitory effect of a phosphatidyl ethanolamine derivative on LPS-induced sepsis.

    PubMed

    Lee, Chunghyun; An, Hyun-Jung; Kim, Jung-Ln; Lee, Hayyoung; Paik, Sang-Gi

    2009-02-28

    Sepsis is the leading cause of death in critically ill patients. Today, around 60% of all cases of sepsis are caused by Gram-negative bacteria. The cell wall component lipopoly-saccharide (LPS) is the main initiator of the cascade of cellular reactions in Gram-negative infections. The core receptors for LPS are toll-like receptor 4 (TLR4), MD-2 and CD14. Attempts have been made to antagonize the toxic effect of endotoxin using monoclonal antibodies against CD14 and synthetic lipopolysaccharides but there is as yet no effective treatment for septic syndrome. Here, we describe an inhibitory effect of a phosphatidylethanolamine derivative, PE-DTPA (phosphatidylethanolamine diethyl-enetriaminepentaacetate) on LPS recognition. PE-DTPA bound strongly to CD14 (K ( d ), 9.52 x 10(-8) M). It dose dependency inhibited LPS-mediated activation of human myeloid cells, mouse macrophage cells and human whole blood as measured by the production of tumor necrosis factor-a (TNF-alpha) and nitric oxide, whereas other phospho-lipids including phosphatidylserine and phosphatidylethanolamine had little effect. PE-DTPA also inhibited transcription dependent on NF-kappaB activation when it was added together with LPS, and it rescued LPS-primed mice from septic death. These results suggest that PE-DTPA is a potent antagonist of LPS, and that it acts by competing for binding to CD14. PMID:19277509

  5. CD14 Mediates Binding of High Doses of LPS but Is Dispensable for TNF-α Production

    PubMed Central

    Borzęcka, Kinga; Płóciennikowska, Agnieszka; Björkelund, Hanna; Sobota, Andrzej

    2013-01-01

    Activation of macrophages with lipopolysaccharide (LPS) involves a sequential engagement of serum LPS-binding protein (LBP), plasma membrane CD14, and TLR4/MD-2 signaling complex. We analyzed participation of CD14 in TNF-α production stimulated with 1–1000 ng/mL of smooth or rough LPS (sLPS or rLPS) and in sLPS binding to RAW264 and J744 cells. CD14 was indispensable for TNF-α generation induced by a low concentration, 1 ng/mL, of sLPS and rLPS. At higher doses of both LPS forms (100–1000 ng/mL), TNF-α release required CD14 to much lower extent. Among the two forms of LPS, rLPS-induced TNF-α production was less CD14-dependent and could proceed in the absence of serum as an LBP source. On the other hand, the involvement of CD14 was crucial for the binding of 1000 ng/mL of sLPS judging from an inhibitory effect of the anti-CD14 antibody. The binding of sLPS was also strongly inhibited by dextran sulfate, a competitive ligand of scavenger receptors (SR). In the presence of dextran sulfate, sLPS-induced production of TNF-α was upregulated about 1.6-fold. The data indicate that CD14 together with SR participates in the binding of high doses of sLPS. However, CD14 contribution to TNF-α production induced by high concentrations of sLPS and rLPS can be limited. PMID:24489448

  6. Systemic and Splanchnic Lipopolysaccharide and Endothelin-1 Plasma Levels in Liver Cirrhosis before and after Transjugular Intrahepatic Portosystemic Shunt

    PubMed Central

    Meng, Jiaxiang; Wang, Qing; Liu, Kai; Yang, Shuofei; Fan, Xinxin; Liu, Baochen; He, Changsheng; Wu, Xingjiang

    2016-01-01

    Lipopolysaccharide (LPS) and endothelin- (ET-) 1 may aggravate portal hypertension by increasing intrahepatic resistance and splanchnic blood flow. In the portal vein, after TIPS shunting, LPS and ET-1 were significantly decreased. Our study suggests that TIPS can benefit cirrhotic patients not only in high hemodynamics related variceal bleeding but also in intestinal bacterial translocation associated complications such as endotoxemia. PMID:26941788

  7. Characterization of Xylella fastidiosa lipopolysaccharide and its role in key steps of the disease cycle in grapevine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This project aims to elucidate molecular mechanisms of Xylella fastidiosa (Xf) pathogenicity. Work is focused on the lipopolysaccharide (LPS) component of the outer membrane, which consists of lipid A, core oligosaccharides, and a variable O-antigen moiety. Specifically, the O-antigen portion of LPS...

  8. Atrial natriuretic peptide attenuates agonist-induced pulmonary edema in mice with targeted disruption of the gene for natriuretic peptide receptor-A

    PubMed Central

    Tsai, Shu-Whei; Green, Sabrina; Grinnell, Katie L.; Machan, Jason T.; Harrington, Elizabeth O.

    2013-01-01

    Atrial natriuretic peptide (ANP) inhibits agonist-induced pulmonary edema formation, but the signaling pathway responsible is not well defined. To investigate the role of the particulate guanylate cyclase-linked receptor, natriuretic peptide receptor-A (NPR-A), we measured acute lung injury responses in intact mice and pulmonary microvascular endothelial cells (PMVEC) with normal and disrupted expression of NPR-A. NPR-A wild-type (NPR-A+/+), heterozygous (NPR-A+/−), and knockout (NPR-A−/−) mice were anesthetized and treated with thrombin receptor agonist peptide (TRAP) or lipopolysaccharide (LPS). Lung injury was assessed by lung wet-to-dry (W/D) weight and by protein and cell concentration of bronchoalveolar lavage (BAL) fluid. No difference in pulmonary edema formation was seen between NPR-A genotypes under baseline conditions. TRAP and LPS increased lung W/D weight and BAL fluid cell counts more in NPR-A−/− mice than in NPR-A+/− or NPR-A+/+ mice, but no genotype-related differences were seen in TRAP-induced increases in bloodless lung W/D weight or LPS-induced increases in BAL protein concentration. Pretreatment with ANP infusion completely blocked TRAP-induced increases in lung W/D weight and blunted LPS-induced increases in BAL cell counts and protein concentration in both NPR-A−/− and NPR-A+/+ mice. Thrombin decreased transmembrane electrical resistance in monolayers of PMVECs in vitro, and this effect was attenuated by ANP in PMVECs isolated from both genotypes. Administration of the NPR-C-specific ligand, cANF, also blocked TRAP-induced increases in lung W/D weight and LPS-induced increases in BAL cell count and protein concentration in NPR-A+/+ and NPR-A−/− mice. We conclude that ANP is capable of attenuating agonist-induced lung edema in the absence of NPR-A. The protective effect of ANP on agonist-induced lung injury and pulmonary barrier function may be mediated by NPR-C. PMID:23195629

  9. Atrial natriuretic peptide attenuates agonist-induced pulmonary edema in mice with targeted disruption of the gene for natriuretic peptide receptor-A.

    PubMed

    Klinger, James R; Tsai, Shu-Whei; Green, Sabrina; Grinnell, Katie L; Machan, Jason T; Harrington, Elizabeth O

    2013-02-01

    Atrial natriuretic peptide (ANP) inhibits agonist-induced pulmonary edema formation, but the signaling pathway responsible is not well defined. To investigate the role of the particulate guanylate cyclase-linked receptor, natriuretic peptide receptor-A (NPR-A), we measured acute lung injury responses in intact mice and pulmonary microvascular endothelial cells (PMVEC) with normal and disrupted expression of NPR-A. NPR-A wild-type (NPR-A+/+), heterozygous (NPR-A+/-), and knockout (NPR-A-/-) mice were anesthetized and treated with thrombin receptor agonist peptide (TRAP) or lipopolysaccharide (LPS). Lung injury was assessed by lung wet-to-dry (W/D) weight and by protein and cell concentration of bronchoalveolar lavage (BAL) fluid. No difference in pulmonary edema formation was seen between NPR-A genotypes under baseline conditions. TRAP and LPS increased lung W/D weight and BAL fluid cell counts more in NPR-A-/- mice than in NPR-A+/- or NPR-A+/+ mice, but no genotype-related differences were seen in TRAP-induced increases in bloodless lung W/D weight or LPS-induced increases in BAL protein concentration. Pretreatment with ANP infusion completely blocked TRAP-induced increases in lung W/D weight and blunted LPS-induced increases in BAL cell counts and protein concentration in both NPR-A-/- and NPR-A+/+ mice. Thrombin decreased transmembrane electrical resistance in monolayers of PMVECs in vitro, and this effect was attenuated by ANP in PMVECs isolated from both genotypes. Administration of the NPR-C-specific ligand, cANF, also blocked TRAP-induced increases in lung W/D weight and LPS-induced increases in BAL cell count and protein concentration in NPR-A+/+ and NPR-A-/- mice. We conclude that ANP is capable of attenuating agonist-induced lung edema in the absence of NPR-A. The protective effect of ANP on agonist-induced lung injury and pulmonary barrier function may be mediated by NPR-C. PMID:23195629

  10. Arabidopsis LBP/BPI related-1 and -2 bind to LPS directly and regulate PR1 expression.

    PubMed

    Iizasa, Sayaka; Iizasa, Ei'ichi; Matsuzaki, Sawako; Tanaka, Hiroyuki; Kodama, Yutaka; Watanabe, Keiichi; Nagano, Yukio

    2016-01-01

    Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and acts as a pathogen-associated molecular pattern that triggers immune responses in both plants and animals. LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI), which bind to LPS and play important roles in immunity of mammals, have been well studied. However, the molecule contributing to LPS binding in plants is mostly unknown. The Arabidopsis genome carries two genes encoding LBP/BPI-related proteins which we designated as AtLBP/BPI related-1 (AtLBR-1) and AtLBP/BPI related-2 (AtLBR-2). We found that their N-terminal domains were co-purified with cell wall-derived LPS when expressed in E. coli. Since this finding implied the direct binding of AtLBRs to LPS, we also confirmed binding by using LPS-free AtLBRs and purified LPS. AtLBRs directly bind to both rough and smooth types of LPS. We also demonstrated that LPS-treated atlbr mutant Arabidopsis exhibit a significant delay of induction of defence-related gene pathogenesis-related 1 (PR1) but no other PR genes. Furthermore, LPS-treated atlbr mutants showed defects in reactive oxygen species (ROS) generation. These results demonstrate that, as well as LBP and BPI of mammals, AtLBRs also play an important role in the LPS-induced immune response of plants. PMID:27273538

  11. Arabidopsis LBP/BPI related-1 and -2 bind to LPS directly and regulate PR1 expression

    PubMed Central

    Iizasa, Sayaka; Iizasa, Ei’ichi; Matsuzaki, Sawako; Tanaka, Hiroyuki; Kodama, Yutaka; Watanabe, Keiichi; Nagano, Yukio

    2016-01-01

    Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and acts as a pathogen-associated molecular pattern that triggers immune responses in both plants and animals. LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI), which bind to LPS and play important roles in immunity of mammals, have been well studied. However, the molecule contributing to LPS binding in plants is mostly unknown. The Arabidopsis genome carries two genes encoding LBP/BPI-related proteins which we designated as AtLBP/BPI related-1 (AtLBR-1) and AtLBP/BPI related-2 (AtLBR-2). We found that their N-terminal domains were co-purified with cell wall-derived LPS when expressed in E. coli. Since this finding implied the direct binding of AtLBRs to LPS, we also confirmed binding by using LPS-free AtLBRs and purified LPS. AtLBRs directly bind to both rough and smooth types of LPS. We also demonstrated that LPS-treated atlbr mutant Arabidopsis exhibit a significant delay of induction of defence-related gene pathogenesis-related 1 (PR1) but no other PR genes. Furthermore, LPS-treated atlbr mutants showed defects in reactive oxygen species (ROS) generation. These results demonstrate that, as well as LBP and BPI of mammals, AtLBRs also play an important role in the LPS-induced immune response of plants. PMID:27273538

  12. Bone repair: Effects of physical exercise and LPS systemic exposition.

    PubMed

    Nogueira, Jonatas E; Branco, Luiz G S; Issa, João Paulo M

    2016-08-01

    Bone repair can be facilitated by grafting, biochemical and physical stimulation. Conversely, it may be delayed lipopolysaccharide (LPS). Physical exercise exerts beneficial effects on the bone, but its effect on bone repair is not known. We investigated the effect of exercise on the LPS action on bone healing through bone densitometry, quantitative histological analysis for bone formation rate and immunohistochemical markers in sedentary and exercised animals. Rats ran on the treadmill for four weeks. After training the rats were submitted to a surgical procedure (bone defect in the right tibia) and 24h after the surgery LPS was administered at a dose of 100μg/kg i.p., whereas the control rats received a saline injection (1ml/kg, i.p.). Right tibias were obtained for analysis after 10days during which rats were not submitted to physical training. Physical exercise had a positive effect on bone repair, increasing bone mineral density, bone mineral content, bone formation rate, type I collagen and osteocalcin expression. These parameters were not affected by systemic administration of LPS. Our data indicate that physical exercise has an important osteogenic effect, which is maintained during acute systemic inflammation induced by exposure to a single dose of LPS. PMID:27319388

  13. Expression Profiling of LPS Responsive miRNA in Primary Human Macrophages

    PubMed Central

    Naqvi, Afsar Raza; Zhong, Sheng; Dang, Hong; Fordham, Jezrom B; Nares, Salvador; Khan, Asma

    2016-01-01

    microRNAs (miRNAs) have emerged as important regulators of the innate and adaptive immune response. The purpose of the present study was to interrogate miRNA profiles of primary human macrophages challenged with bacterial lipopolysaccharide (LPS) with focus on expression kinetics. We employed Nanostring platform to precisely characterize the changes in miRNA expression following different doses and durations of LPS exposure. Differentially expressed miRNAs were identified in response to LPS challenge with convergent and divergent expression profiles. Pathway analysis of LPS-responsive miRNAs revealed regulation of biological processes linked to key cell signaling (including PIK3-Akt, MAP kinase, ErbB) and pathogen response pathways. Our data provide a comprehensive miRNA profiling of human primary macrophages treated with LPS. These results show that bacterial Toll like receptor (TLR) ligands can temporally modulate macrophage miRNA expression. PMID:27307950

  14. ROLE OF CELL SIGNALING IN PROTECTION FROM DIESEL AND LPS INDUCED ACUTE LUNG INJURY

    EPA Science Inventory

    We have previously demonstrated in CD-1 mice that pre-administration of N-acetyl cysteine (NAC) or the p38 MAP kinase inhibitor (SB203580) reduces acute lung injury and inflammation following pulmonary exposures to diesel exhaust particles (DEP) or lipopolysaccharide (LPS). Here ...

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

    PubMed

    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 < 0.01) decreased in LPS-Propolfenol(®) rabbits. In conclusion, a chocolate and propolis-enriched diet showed a protective effect on the spermatogenetic process of buck rabbits following LPS treatment. PMID:24785944

  16. Impaired phagocyte responses to lipopolysaccharide in paroxysmal nocturnal hemoglobinuria.

    PubMed Central

    Duchow, J; Marchant, A; Crusiaux, A; Husson, C; Alonso-Vega, C; De Groote, D; Neve, P; Goldman, M

    1993-01-01

    Bone marrow-derived cells from patients suffering from paroxysmal nocturnal hemoglobinuria (PNH) show a defect in the expression of phosphatidylinositol-anchored membrane proteins, including the CD14 molecule. Blocking experiments with anti-CD14 monoclonal antibodies have shown that lipopolysaccharide (LPS)-induced tumor necrosis factor alpha production by monocytes depends on the interaction between CD14 and a complex formed by LPS and LPS-binding protein. We used a whole-blood model to examine the LPS-induced production of tumor necrosis factor alpha and interleukin-6 in PNH patients and healthy volunteers. At low endotoxin concentrations (1 ng/ml), PNH patients displayed a marked defect in the production of both cytokines, whereas at high LPS concentrations (100 ng/ml), cytokine production was similar to that in healthy volunteers. Using flow cytometry, we also studied the expression of the adhesion molecules Mac-1 (CD11b/CD18) and ICAM-1 (CD54) by monocytes and granulocytes after LPS stimulation. Compared with phagocytes from healthy volunteers, CD14-deficient cells showed poor Mac-1 and ICAM-1 upregulation when whole blood was stimulated with LPS (1 ng/ml), whereas their response to higher LPS doses (100 and 1,000 ng/ml) was essentially normal. The importance of the CD14 molecule in the activation of phagocytes by low LPS concentrations was confirmed by the inhibitory effect of an anti-CD14 antibody both in healthy volunteers and in PNH patients. Since these patients produce the soluble form of the CD14 molecule, these data suggest that soluble CD14 could play a role in phagocyte responses to LPS. We conclude that, in whole blood, phagocytes from PNH patients show impaired responsiveness to LPS and this phenomenon is most probably related to their defect in expression of membrane CD14. PMID:7691746

  17. Identification and Characterization of a Glycosyltransferase Involved in Acinetobacter baumannii Lipopolysaccharide Core Biosynthesis▿

    PubMed Central

    Luke, Nicole R.; Sauberan, Shauna L.; Russo, Thomas A.; Beanan, Janet M.; Olson, Ruth; Loehfelm, Thomas W.; Cox, Andrew D.; St. Michael, Frank; Vinogradov, Evgeny V.; Campagnari, Anthony A.

    2010-01-01

    Although Acinetobacter baumannii has emerged as a significant cause of nosocomial infections worldwide, there have been few investigations describing the factors important for A. baumannii persistence and pathogenesis. This paper describes the first reported identification of a glycosyltransferase, LpsB, involved in lipopolysaccharide (LPS) biosynthesis in A. baumannii. Mutational, structural, and complementation analyses indicated that LpsB is a core oligosaccharide glycosyl transferase. Using a genetic approach, lpsB was compared with the lpsB homologues of several A. baumannii strains. These analyses indicated that LpsB is highly conserved among A. baumannii isolates. Furthermore, we developed a monoclonal antibody, monoclonal antibody 13C11, which reacts to an LPS core epitope expressed by approximately one-third of the A. baumannii clinical isolates evaluated to date. Previous studies describing the heterogeneity of A. baumannii LPS were limited primarily to structural analyses; therefore, studies evaluating the correlation between these surface glycolipids and pathogenesis were warranted. Our data from an evaluation of LpsB mutant 307::TN17, which expresses a deeply truncated LPS glycoform consisting of only two 3-deoxy-d-manno-octulosonic acid residues and lipid A, suggest that A. baumannii LPS is important for resistance to normal human serum and confers a competitive advantage for survival in vivo. These results have important implications for the role of LPS in A. baumannii infections. PMID:20194587

  18. Pseudomonas aeruginosa PAO-1 Lipopolysaccharide-Diphtheria Toxoid Conjugate Vaccine: Preparation, Characterization and Immunogenicity

    PubMed Central

    Najafzadeh, Faezeh; Shapouri, Reza; Rahnema, Mehdi; Rokhsartalab Azar, Shadi; Kianmehr, Anvarsadat

    2015-01-01

    Background: Treatment of Pseudomonas aeruginosa PAO-1 infections through immunological means has been proved to be efficient and protective. Objectives: The purpose of this study was to produce a conjugate vaccine composed of detoxified lipopolysaccharide (D-LPS) P. aeruginosa and diphtheria toxoid (DT). Materials and Methods: Firstly, LPS was purified and characterized from P. aeruginosa PAO1 and then detoxified. D-LPS was covalently coupled to DT as a carrier protein via amidation method with adipic acid dihydrazide (ADH) as a spacer molecule and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDAC) as a linker. The molar ratio of LPS to DT in the prepared conjugate was 3:1. The immunogenicity of D-LPS-DT conjugate vaccine in mice model was evaluated as well. Results: The conjugate was devoid of endotoxin activity and 0.125 U/mL of D-LPS was acceptable for immunization. D-LPS-DT conjugate was nonpyrogenic for rabbits and nontoxic for mice. Mice immunization with D-LPS-DT conjugate vaccine elicited the fourfold higher IgG antibody compared to D-LPS. Anti-LPS IgG antibody was predominantly IgG1 subclass and then IgG3, IgG2a and IgG2b, respectively. Conclusions: Vaccine based on the conjugation of P. aeruginosa PAO-1 LPS with DT increased anti-LPS antibodies and had a significant potential to protect against Pseudomonas infections. PMID:26301059

  19. Identification and characterization of a glycosyltransferase involved in Acinetobacter baumannii lipopolysaccharide core biosynthesis.

    PubMed

    Luke, Nicole R; Sauberan, Shauna L; Russo, Thomas A; Beanan, Janet M; Olson, Ruth; Loehfelm, Thomas W; Cox, Andrew D; St Michael, Frank; Vinogradov, Evgeny V; Campagnari, Anthony A

    2010-05-01

    Although Acinetobacter baumannii has emerged as a significant cause of nosocomial infections worldwide, there have been few investigations describing the factors important for A. baumannii persistence and pathogenesis. This paper describes the first reported identification of a glycosyltransferase, LpsB, involved in lipopolysaccharide (LPS) biosynthesis in A. baumannii. Mutational, structural, and complementation analyses indicated that LpsB is a core oligosaccharide glycosyl transferase. Using a genetic approach, lpsB was compared with the lpsB homologues of several A. baumannii strains. These analyses indicated that LpsB is highly conserved among A. baumannii isolates. Furthermore, we developed a monoclonal antibody, monoclonal antibody 13C11, which reacts to an LPS core epitope expressed by approximately one-third of the A. baumannii clinical isolates evaluated to date. Previous studies describing the heterogeneity of A. baumannii LPS were limited primarily to structural analyses; therefore, studies evaluating the correlation between these surface glycolipids and pathogenesis were warranted. Our data from an evaluation of LpsB mutant 307::TN17, which expresses a deeply truncated LPS glycoform consisting of only two 3-deoxy-d-manno-octulosonic acid residues and lipid A, suggest that A. baumannii LPS is important for resistance to normal human serum and confers a competitive advantage for survival in vivo. These results have important implications for the role of LPS in A. baumannii infections. PMID:20194587

  20. Brucella spp noncanonical LPS: structure, biosynthesis, and interaction with host immune system

    PubMed Central

    Cardoso, Patrícia Gomes; Macedo, Gilson Costa; Azevedo, Vasco; Oliveira, Sergio Costa

    2006-01-01

    Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and non-professional phagocytes, and cause abortion in domestic animals and undulant fever in humans. Several species are recognized within the genus Brucella and this classification is mainly based on the difference in pathogenicity and in host preference. Brucella strains may occur as either smooth or rough, expressing smooth LPS (S-LPS) or rough LPS (R-LPS) as major surface antigen. This bacterium possesses an unconventional non-endotoxic lipopolysaccharide that confers resistance to anti-microbial attacks and modulates the host immune response. The strains that are pathogenic for humans (B. abortus, B. suis, B. melitensis) carry a smooth LPS involved in the virulence of these bacteria. The LPS O-chain protects the bacteria from cellular cationic peptides, oxygen metabolites and complement-mediated lysis and it is a key molecule for Brucella survival and replication in the host. Here, we review i) Brucella LPS structure; ii) Brucella genome, iii) genes involved in LPS biosynthesis; iv) the interaction between LPS and innate immunity. PMID:16556309

  1. Lipopolysaccharide-Related Stimuli Induce Expression of the Secretory Leukocyte Protease Inhibitor, a Macrophage-Derived Lipopolysaccharide Inhibitor

    PubMed Central

    Jin, Fenyu; Nathan, Carl F.; Radzioch, Danuta; Ding, Aihao

    1998-01-01

    Mouse secretory leukocyte protease inhibitor (SLPI) was recently characterized as a lipopolysaccharide (LPS)-induced product of macrophages that antagonizes their LPS-induced activation of NF-κB and production of NO and tumor necrosis factor (TNF) (F. Y. Jin, C. Nathan, D. Radzioch, and A. Ding, Cell 88:417–426, 1997). To better understand the role of SLPI in innate immune and inflammatory responses, we examined the kinetics of SLPI expression in response to LPS, LPS-induced cytokines, and LPS-mimetic compounds. SLPI mRNA was detectable in macrophages by Northern blot analysis within 30 min of exposure to LPS but levels peaked only at 24 to 36 h and remained elevated at 72 h. Despite the slowly mounting and prolonged response, early expression of SLPI mRNA was cycloheximide resistant. Two LPS-induced proteins—interleukin-10 (IL-10) and IL-6—also induced SLPI, while TNF and IL-1β did not. The slow attainment of maximal induction of SLPI by LPS in vitro was mimicked by infection with Pseudomonas aeruginosa in vivo, where SLPI expression in the lung peaked at 3 days. Two LPS-mimetic molecules—taxol from yew bark and lipoteichoic acid (LTA) from gram-positive bacterial cell walls—also induced SLPI. Transfection of macrophages with SLPI inhibited their LTA-induced NO production. An anti-inflammatory role for macrophage-derived SLPI seems likely based on SLPI’s slowly mounting production in response to constituents of gram-negative and gram-positive bacteria, its induction both as a direct response to LPS and as a response to anti-inflammatory cytokines induced by LPS, and its ability to suppress the production of proinflammatory products by macrophages stimulated with constituents of both gram-positive and gram-negative bacteria. PMID:9596701

  2. Lipopolysaccharide induced conversion of recombinant prion protein

    PubMed Central

    Saleem, Fozia; Bjorndahl, Trent C; Ladner, Carol L; Perez-Pineiro, Rolando; Ametaj, Burim N; Wishart, David S

    2014-01-01

    The conformational conversion of the cellular prion protein (PrPC) to the β-rich infectious isoform PrPSc is considered a critical and central feature in prion pathology. Although PrPSc is the critical component of the infectious agent, as proposed in the “protein-only” prion hypothesis, cellular components have been identified as important cofactors in triggering and enhancing the conversion of PrPC to proteinase K resistant PrPSc. A number of in vitro systems using various chemical and/or physical agents such as guanidine hydrochloride, urea, SDS, high temperature, and low pH, have been developed that cause PrPC conversion, their amplification, and amyloid fibril formation often under non-physiological conditions. In our ongoing efforts to look for endogenous and exogenous chemical mediators that might initiate, influence, or result in the natural conversion of PrPC to PrPSc, we discovered that lipopolysaccharide (LPS), a component of gram-negative bacterial membranes interacts with recombinant prion proteins and induces conversion to an isoform richer in β sheet at near physiological conditions as long as the LPS concentration remains above the critical micelle concentration (CMC). More significant was the LPS mediated conversion that was observed even at sub-molar ratios of LPS to recombinant ShPrP (90–232). PMID:24819168

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

    PubMed

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

    2004-05-01

    Endotoxin-neutralizing protein (ENP) of the horseshoe crab is one of the most potent neutralizers of endotoxins [bacterial lipopolysaccharide (LPS)]. Here, we report on the interaction of LPS with recombinant ENP using a variety of physical and biological techniques. In biological assays (Limulus amebocyte lysate and tumour necrosis factor-alpha induction in human mononuclear cells), ENP causes a strong reduction of the immunostimulatory ability of LPS in a dose-dependent manner. Concomitantly, the accessible negative surface charges of LPS and lipid A (zeta potential) are neutralized and even converted into positive values. The gel to liquid crystalline phase transitions of LPS and lipid A shift to higher temperatures indicative of a rigidification of the acyl chains, however, the only slight enhancement of the transition enthalpy indicates that the hydrophobic moiety is not strongly disturbed. The aggregate structure of lipid A is converted from a cubic into a multilamellar phase upon ENP binding, whereas the secondary structure of ENP does not change due to the interaction with LPS. ENP contains a hydrophobic binding site to which the dye 1-anilino-8-sulfonic acid binds at a K(d) of 19 micro m, which is displaced by LPS. Because lipopolysaccharide-binding protein (LBP) is not able to bind to LPS when ENP and LPS are preincubated, tight binding of ENP to LPS can be deduced with a K(d) in the low nonomolar range. Importantly, ENP is able to incorporate by itself into target phospholipid liposomes, and is also able to mediate the intercalation of LPS into the liposomes thus acting as a transport protein in a manner similar to LBP. Thus, LPS-ENP complexes might enter target membranes of immunocompetent cells, but are not able to activate due to the ability of ENP to change LPS aggregates from an active into an inactive form. PMID:15128313

  4. Selective pressures and lipopolysaccharide subunits as determinants of resistance of clinical isolates of gram-negative bacilli to human serum.

    PubMed Central

    Porat, R; Johns, M A; McCabe, W R

    1987-01-01

    Differences in molecular composition of lipopolysaccharides (LPS) between serum-sensitive (S) clinical isolates of Escherichia coli and serum-resistant (R) clones derived by serial passage in serum were demonstrated to determine sensitivity or resistance to killing by normal human serum (NHS). LPS from R clones had a greater proportion of higher-molecular-weight, more highly O-antigen-substituted subunits than LPS from their serum S parents. Utilization of a liposomal model with inserted LPS simulating bacterial cell walls established LPS as the site of serum bactericidal action. Liposomes containing S LPS were lysed, while liposomes containing R LPS were unaffected by NHS. R and S LPS were fractionated into higher (F1)- and lower (F2)-molecular-weight fractions. Liposomes containing R LPS or the F1 fraction of S and R LPS were not lysed by serum. Liposomes containing the F2 fraction of S or R LPS were lysed by serum analogous to that observed with liposomes containing intact S LPS. These findings establish LPS to be one site of serum bactericidal activity and demonstrate that the higher-molecular-weight, highly O-antigen-substituted LPS subunits mediate resistance to killing by NHS. Images PMID:3804440

  5. Activation of the anti-inflammatory reflex blocks lipopolysaccharide-induced decrease in synaptic inhibition in the temporal cortex of the rat.

    PubMed

    Garcia-Oscos, Francisco; Peña, David; Housini, Mohammad; Cheng, Derek; Lopez, Diego; Cuevas-Olguin, Roberto; Saderi, Nadia; Salgado Delgado, Roberto; Galindo Charles, Luis; Salgado Burgos, Humberto; Rose-John, Stefan; Flores, Gonzalo; Kilgard, Michael P; Atzori, Marco

    2015-06-01

    Stress is a potential trigger for a number of neuropsychiatric conditions, including anxiety syndromes and schizophrenic psychoses. The temporal neocortex is a stress-sensitive area involved in the development of such conditions. We have recently shown that aseptic inflammation and mild electric shock shift the balance between synaptic excitation and synaptic inhibition in favor of the former in this brain area (Garcia-Oscos et al., 2012), as well as in the prefrontal cortex (Garcia-Oscos et al., 2014). Given the potential clinical importance of this phenomenon in the etiology of hyperexcitable neuropsychiatric illness, this study investigates whether inactivation of the peripheral immune system by the "anti-inflammatory reflex" would reduce the central response to aseptic inflammation. For a model of aseptic inflammation, this study used i.p. injections of the bacterial toxin lipopolysaccharide (LPS; 5 µM) and activated the anti-inflammatory reflex either pharmacologically by i.p. injections of the nicotinic α7 receptor agonist PHA543613 or physiologically through electrical stimulation of the left vagal nerve (VNS). Patch-clamp recording was used to monitor synaptic function. Recordings from LPS-injected Sprague Dawley rats show that activation of the anti-inflammatory reflex either pharmacologically or by VNS blocks or greatly reduces the LPS-induced decrease of the synaptic inhibitory-to-excitatory ratio and the saturation level of inhibitory current input-output curves. Given the ample variety of pharmacologically available α7 nicotinic receptor agonists as well as the relative safety of clinical VNS already approved by the FDA for the treatment of epilepsy and depression, our findings suggest a new therapeutic avenue in the treatment of stress-induced hyperexcitable conditions mediated by a decrease in synaptic inhibition in the temporal cortex. PMID:25626997

  6. SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

    SciTech Connect

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

    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

  7. Hemopexin down-regulates LPS-induced proinflammatory cytokines from macrophages

    PubMed Central

    Liang, Xueya; Lin, Tian; Sun, Guangjie; Beasley-Topliffe, Laura; Cavaillon, Jean-Marc; Warren, H. Shaw

    2009-01-01

    Detection of LPS in tissues is an integral component of innate immunity that acts to protect against invasion by Gram-negative bacteria. Plasma down-regulates LPS-induced cytokine production from macrophages, thereby limiting systemic inflammation in blood and distant tissues. To identify the protein(s) involved in this process, we used classical biochemical chromatographic techniques to identify fractions of mouse sera that suppress LPS-induced TNF from bone marrow-derived macrophages (BMDMs). Fractionation yielded microgram quantities of a protein that was identified by MS to be hemopexin (Hx). Mouse Hx purified on hemin-agarose beads and rhHx decreased the production of cytokines from BMDMs and peritoneal macrophages induced by LPS. Preincubation of LPS with Hx did not affect the activity of LPS on LAL, whereas preincubation of Hx with macrophages followed by washing resulted in decreased activity of these cells in response to LPS, suggesting that Hx acts on macrophages rather than LPS. Heme-free Hx did not stimulate HO-1 in the macrophages. Purified Hx also decreased TNF and IL-6 from macrophages induced by the synthetic TLR2 agonist Pam3Cys. Our data suggest that Hx, which is an acute-phase protein that increases during inflammation, limits TLR4 and TLR2 agonist-induced macrophage cytokine production directly through a mechanism distinct from HO-1. PMID:19395472

  8. Lipopolysaccharide Disrupts Mitochondrial Physiology in Skeletal Muscle via Disparate Effects on Sphingolipid Metabolism

    PubMed Central

    Hansen, Melissa E.; Simmons, Kurtis J.; Tippetts, Trevor S.; Thatcher, Mikayla O.; Saito, Rex R.; Hubbard, Sheryl T.; Trumbull, Annie M.; Parker, Brian A.; Taylor, Oliver J.; Bikman, Benjamin T.

    2015-01-01

    ABSTRACT Lipopolysaccharides (LPS) are prevalent pathogenic molecules that are found within tissues and blood. Elevated circulating LPS is a feature of obesity and sepsis, both of which are associated with mitochondrial abnormalities that are key pathological features of LPS excess. However, the mechanism of LPS-induced mitochondrial alterations remains poorly understood. Herein we demonstrate the necessity of sphingolipid accrual in mediating altered mitochondrial physiology in skeletal muscle following LPS exposure. In particular, we found LPS elicited disparate effects on the sphingolipids dihydroceramides (DhCer) and ceramides (Cer) in both cultured myotubes and in muscle of LPS-injected mice. Although LPS-treated myotubes had reduced DhCer and increased Cer as well as increased mitochondrial respiration, muscle from LPS-injected mice manifested a reverse trend, namely elevated DhCer, but reduced Cer as well as reduced mitochondrial respiration. In addition, we found that LPS treatment caused mitochondrial fission, likely via dynamin-related protein 1, and increased oxidative stress. However, inhibition of de novo sphingolipid biosynthesis via myriocin protected normal mitochondrial function in spite of LPS, but inhibition of DhCer desaturase 1, which increases DhCer, but not Cer, exacerbated mitochondrial respiration with LPS. In an attempt to reconcile the incongruent effects of LPS in isolated muscle cells and whole muscle tissue, we incubated myotubes with conditioned medium from treated macrophages. In contrast to direct myotube LPS treatment, conditioned medium from LPS-treated macrophages reduced myotube respiration, but this was again mitigated with sphingolipid inhibition. Thus, macrophage sphingolipid production appears to be necessary for LPS-induced mitochondrial alterations in skeletal muscle tissue. PMID:26529656

  9. Legionella pneumophila lipopolysaccharide activates the classical complement pathway.

    PubMed Central

    Mintz, C S; Schultz, D R; Arnold, P I; Johnson, W

    1992-01-01

    Legionella pneumophila is a gram-negative bacterium capable of entering and growing in alveolar macrophages and monocytes. Complement and complement receptors are important in the uptake of L. pneumophila by human mononuclear phagocytes. The surface molecules of L. pneumophila that activate the complement system are unknown. To identify these factors, we investigated the effects of L. pneumophila lipopolysaccharide (LPS) on the classical and alternative complement pathways of normal human serum by functional hemolytic assays. Although incubation of LPS in normal human serum at 37 degrees C resulted in the activation of both pathways, complement activation proceeded primarily through the classical pathway. Activation of the classical pathway by LPS was dependent on natural antibodies of the immunoglobulin M class that were present in various quantities in sera from different normal individuals but were absent in an immunoglobulin-deficient serum obtained from an agammaglobulinemic patient. Additional studies using sheep erythrocytes coated with LPS suggested that the antibodies recognized antigenic sites in the carbohydrate portion of LPS. The ability of LPS to interact with the complement system suggests a role for LPS in the uptake of L. pneumophila by mononuclear phagocytes. PMID:1612744

  10. Effects of lipopolysaccharide on the catabolic activity of macrophages

    SciTech Connect

    Cluff, C.; Ziegler, H.K.

    1986-03-05

    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 /sup 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.

  11. Wogonoside ameliorates lipopolysaccharide-induced acute lung injury in mice.

    PubMed

    Zhang, Liang; Ren, Yi; Yang, Chengliang; Guo, Yue; Zhang, Xiaojing; Hou, Gang; Guo, Xinjin; Sun, Nan; Liu, Yongyu

    2014-12-01

    Wogonoside has been reported to have anti-inflammatory properties. In this study, we evaluated the effect of wogonoside on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Male BALB/c mice with ALI, induced by intranasal instillation of LPS, were treated with wogonoside 1 h prior to LPS exposure. Mice treated with LPS alone showed significantly increased TNF-α, IL-6, and IL-1β levels in the bronchoalveolar lavage fluid (BALF). When pretreated with wogonoside, the TNF-α, IL-6, and IL-1β levels were significantly decreased. Meanwhile, wogonoside significantly inhibited LPS-induced increases in the macrophage and neutrophil infiltration of lung tissues and markedly attenuated myeloperoxidase activity. Furthermore, wogonoside inhibited the TLR4 expression and the phosphorylation of NF-κB p65, and IκB induced by LPS. In conclusion, our results indicate that wogonoside exhibits a protective effect on LPS-induced ALI via suppression of TLR4-mediated NF-κB signaling pathways. PMID:24854163

  12. Characterization of the lipopolysaccharide from Vibrio cholerae 395 (Ogawa).

    PubMed Central

    Kabir, S

    1982-01-01

    The chemical structure and biological properties of the lipopolysaccharide (LPS) from Vibrio cholerae 395 (Ogawa), isolated by the phenol-water procedure, were studied. Upon acid hydrolysis, the LPS was split into its polysaccharide and lipid A moieties. The polysaccharide contained both neutral (glucose, heptose, fructose) and amino (glucosamine, quinovosamine) sugars. The LPS contained the acid-labile amino sugar, 4-amino-arabinose, which was absent in the Inaba serotype of V. cholerae. The LPS differed from the LPSs of Enterobacteriaceae by the absence of 2-keto-3-deoxyoctonate and the presence of fructose. Analysis of the methylated polysaccharide by gas-liquid chromatography and mass spectrometry showed that it had a branched structure with glucose and heptose residues primarily appearing at the nonreducing-end groups. Interactions with lectins, concanavalin A. and wheat germ agglutinin suggested that terminal glucose residues were alpha linked, whereas terminal glucosamine residues were connected by alpha-1,3 linkages. The major fatty acids of the LPS were C14:0, C16:0, C12h:0, and C14h:0 compounds, of which only the C14h:0 were amide linked, the remainder being ester linked to the backbone. Biological studies showed that the LPS possessed endotoxic properties such as lethality, pyrogenicity, limulus lysate gelation, and ability to induce non-specific resistance to infection. Thus, the LPS from V. cholerae 395 (Ogawa) possessed both common and distinct features as compared with the LPSs from the Enterobacteriaceae. Images PMID:7152669

  13. Bacterial lipopolysaccharide promotes destabilization of lung surfactant-like films.

    PubMed

    Cañadas, Olga; Keough, Kevin M W; Casals, Cristina

    2011-01-01

    The airspaces are lined with a dipalmitoylphosphatidylcholine (DPPC)-rich film called pulmonary surfactant, which is named for its ability to maintain normal respiratory mechanics by reducing surface tension at the air-liquid interface. Inhaled airborne particles containing bacterial lipopolysaccharide (LPS) may incorporate into the surfactant monolayer. In this study, we evaluated the effect of smooth LPS (S-LPS), containing the entire core oligosaccharide region and the O-antigen, on the biophysical properties of lung surfactant-like films composed of either DPPC or DPPC/palmitoyloleoylphosphatidylglycerol (POPG)/palmitic acid (PA) (28:9:5.6, w/w/w). Our results show that low amounts of S-LPS fluidized DPPC monolayers, as demonstrated by fluorescence microscopy and changes in the compressibility modulus. This promoted early collapse and prevented the attainment of high surface pressures. These destabilizing effects could not be relieved by repeated compression-expansion cycles. Similar effects were observed with surfactant-like films composed of DPPC/POPG/PA. On the other hand, the interaction of SP-A, a surfactant membrane-associated alveolar protein that also binds to LPS, with surfactant-like films containing S-LPS increased monolayer destabilization due to the extraction of lipid molecules from the monolayer, leading to the dissolution of monolayer material in the aqueous subphase. This suggests that SP-A may act as an LPS scavenger. PMID:21190662

  14. Effect of lipopolysaccharide on the hemocyte apoptosis of Eriocheir sinensis *

    PubMed Central

    Xu, Hai-sheng; Lyu, Sun-jian; Xu, Jie-hao; Lu, Bin-jie; Zhao, Jing; Li, Song; Li, Yi-qun; Chen, Yu-yin

    2015-01-01

    In the present study, we investigated the possible toxicity mechanism of lipopolysaccharide (LPS) extracted from Gram-negative bacteria in Eriocheir sinensis hemocytes. Apoptotic hemocytes and reactive oxygen species (ROS) production induced by the LPS were monitored by the combination of flow cytometry and microscope observation. It was shown that LPS induced serious damage on the DNA and morphological changes in hemocytes, including cell shrinkage, fracture of nucleus membrane, margination, condensation and fragmentation of chromatin, and formation of apoptotic bodies indicating obvious hemocyte apoptosis. As compared with the control group, the apoptotic cell ratio increased to 30.61% and 39.01% after 1-h exposure and 57.72% and 75.01% after 2-h exposure to 1 and 10 μg/ml LPS, respectively (P<0.05). Significant outburst of ROS production was observed in LPS-treated hemocytes with approximately 176.6% of relative dichlorofluorescein mean fluorescence at 1-h exposure, followed by a drastic decline (P<0.05). These results indicated that LPS would induce oxidative stress on hemocytes from E. sinensis and cause ROS burst, DNA damage, and subsequently apoptosis. The process of ROS-mediated apoptosis might be one of the potential toxicity mechanisms of LPS on crustacean hemocytes. PMID:26642180

  15. Chikusetsusaponin V attenuates lipopolysaccharide-induced liver injury in mice.

    PubMed

    Dai, Yan Wen; Zhang, Chang Cheng; Zhao, Hai Xia; Wan, Jing Zhi; Deng, Li Li; Zhou, Zhi Yong; Dun, Yao Yan; Liu, Chao Qi; Yuan, Ding; Wang, Ting

    2016-06-01

    Chikusetsusaponin V (CsV), a saponin from Panax japonicus, has been reported to inhibit inflammatory responses in lipopolysaccharide (LPS)-induced macrophage cells. However, whether CsV could alleviate LPS-induced liver injury in vivo and the potential mechanisms involved remain unclear. In the present study, we investigated the anti-inflammatory effects of CsV on LPS-induced acute liver injury in mice and further explored the potential mechanisms involved. Our results showed that CsV significantly attenuated elevation of alanine transaminase (ALT) and aspartate aminotransferase (AST) levels and improved liver histopathological changes in LPS-induced mice. In addition, CsV decreased serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels and inhibited mRNA expressions of inducible nitric oxide synthase (iNOS), TNF-α and IL-1β in LPS challenged mice. Furthermore, CsV inhibited nuclear factor kappa B (NF-κB) activation by downregulating phosphorylated NF-κB, IκB-α, ERK, c-Jun N-terminal kinase (JNK) and p38 levels in the liver tissue, which ultimately decreased nucleus NF-κB protein level. In conclusion, our data suggested that CsV could be a promising drug for preventing LPS challenged liver injury since it attenuated LPS-induced inflammatory responses, partly via inhibiting NF-κB and MAPK signaling pathways. PMID:26981791

  16. Interleukin-1 in Lipopolysaccharide Induced Chorioamnionitis in the Fetal Sheep

    PubMed Central

    Berry, Clare A.; Nitsos, Ilias; Hillman, Noah H.; Pillow, J. Jane; Polglase, Graeme R.; Kramer, Boris W.; Kemp, Matthew W.; Newnham, John P.; Jobe, Alan H.; Kallapur, Suhas G.

    2011-01-01

    We tested the hypothesis that interleukin 1 (IL-1) mediates intra-amniotic lipopolysaccharide (LPS)-induced chorioamnionitis in preterm fetal sheep. Time-mated Merino ewes with singleton fetuses received IL-1α, LPS, or saline (control) by intra-amniotic injection 1 to 2 days before operative delivery at 124 ± 1 days gestational age (N = 5-9/group; term = 150 days). Recombinant human IL-1 receptor antagonist (rhIL-1ra) was given into the amniotic fluid 3 hours before intra-amniotic LPS or saline to block IL-1 signaling. Inflammation in the chorioamnion was determined by histology, cytokine messenger RNA (mRNA), protein expression, and by quantitation of activated inflammatory cells. Intra-amniotic IL-1 and LPS both induced chorioamnionitis. However, IL-1 blockade with IL-1ra did not decrease intra-amniotic LPS-induced increases in pro-inflammatory cytokine mRNAs, numbers of inflammatory cells, myeloperoxidase, or monocyte chemotactic protein-1-expressing cells in the chorioamnion. We conclude that IL-1 and LPS both can cause chorioamnionitis, but IL-1 is not an important mediator of LPS-induced chorioamnionitis in fetal sheep. PMID:21493953

  17. Biophysical characterization of lipopolysaccharide and lipid A inactivation by lactoferrin.

    PubMed

    Brandenburg, K; Jürgens, G; Müller, M; Fukuoka, S; Koch, M H

    2001-08-01

    The interaction of bacterial endotoxins (LPS Re and lipid A, the 'endotoxic principle' of LPS) with the endogenous antibiotic lactoferrin (LF) was investigated using various physical techniques and biological assays. By applying Fourier-transform infrared (FTIR) spectroscopy, we find that LF binds to the phosphate group within the lipid A part and induces a rigidification of the acyl chains of LPS. The secondary structure of the protein - as monitored by the amide I band - is, however, not changed. Concomitant with the IR data, scanning calorimetric data indicate a sharpening of the acyl chain phase transition. From titration calorimetric and zeta potential data, saturation of LF binding to LPS was found to lie at a [LF]:[LPS] ratio of 1:3 to 1:5 M from the former and 1:10 M from the latter technique. X-ray scattering data indicate a change of the lipid A aggregate structure from inverted cubic to multilamellar, and with fluorescence (FRET) spectroscopy, LF is shown to intercalate by itself into phospholipid liposomes and may also block the lipopolysaccharide-binding protein (LBP)-induced intercalation of LPS. The LPS-induced cytokine production of human mononuclear cells exhibits a decrease due to LF binding, whereas the coagulation of amebocyte lysate in the Limulus test exhibited concentration-dependent changes. Based on these results, a model for the mechanisms of endotoxin inactivation by LF is proposed. PMID:11592403

  18. Repeated LPS Injection Induces Distinct Changes in the Kynurenine Pathway in Mice.

    PubMed

    Larsson, M K; Faka, A; Bhat, M; Imbeault, S; Goiny, M; Orhan, F; Oliveros, A; Ståhl, S; Liu, X C; Choi, D S; Sandberg, K; Engberg, G; Schwieler, L; Erhardt, S

    2016-09-01

    The immune system has been recognized as a potential contributor to psychiatric disorders. In animals, lipopolysaccharide (LPS) is used to induce inflammation and behaviors analogous to some of the symptoms in these disorders. Recent data indicate that the kynurenine pathway contributes to LPS-induced aberrant behaviors. However, data are inconclusive regarding optimal LPS dose and treatment strategy. Here, we therefore aimed to evaluate the effects of single versus repeated administration of LPS on the kynurenine pathway. Adult C57BL6 mice were given 0.83 mg/kg LPS as a single or a repeated injection (LPS + LPS) and sacrificed after 24, 48, 72, or 120 h. Mice receiving LPS + LPS had significantly elevated brain kynurenine levels at 24 and 48 h, and elevated serum kynurenine at 24, 48 and 72 h. Brain kynurenic acid and quinolinic acid were significantly increased at 24 and 48 h in mice receiving LPS + LPS, whereas serum kynurenic acid levels were significantly decreased at 24 h. The increase of brain kynurenic acid by LPS + LPS was likely unrelated to the higher total dose as a separate group of mice receiving 1.66 mg/kg LPS as single injection 24 h prior to sacrifice did not show increased brain kynurenic acid. Serum quinolinic acid levels were not affected by LPS + LPS compared to vehicle. Animals given repeated injections of LPS showed a more robust induction of the kynurenine pathway in contrast to animals receiving a single injection. These results may be valuable in light of data showing the importance of the kynurenine pathway in psychiatric disorders. PMID:27165635

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

    SciTech Connect

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

    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.

  20. Montelukast attenuates lipopolysaccharide-induced cardiac injury in rats.

    PubMed

    Khodir, A E; Ghoneim, H A; Rahim, M A; Suddek, G M

    2016-04-01

    This study investigates the possible protective effects of montelukast (MNT) against lipopolysaccharide (LPS)-induced cardiac injury, in comparison to dexamethasone (DEX), a standard anti-inflammatory. Male Sprague Dawley rats (160-180 g) were assigned to five groups (n = 8/group): (1) control; (2) LPS (10 mg/kg, intraperitoneal (i.p.)); (3) LPS + MNT (10 mg/kg, per os (p.o.)); (4) LPS + MNT (20 mg/kg, p.o.); and (5) LPS + DEX (1 mg/kg, i.p.). Twenty-four hours after LPS injection, heart/body weight (BW) ratio and percent survival of rats were determined. Serum total protein, creatine kinase muscle/brain (CK-MB), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) activities were measured. Heart samples were taken for histological assessment and for determination of malondialdehyde (MDA) and glutathione (GSH) contents. Cardiac tumor necrosis factor α (TNF-α) expression was evaluated immunohistochemically. LPS significantly increased heart/BW ratio, serum CK-MB, ALP, and LDH activities and decreased percent survival and serum total protein levels. MDA content increased in heart tissues with a concomitant reduction in GSH content. Immunohistochemical staining of heart specimens from LPS-treated rats revealed high expression of TNF-α. MNT significantly reduced percent mortality and suppressed the release of inflammatory and oxidative stress markers when compared with LPS group. Additionally, MNT effectively preserved tissue morphology as evidenced by histological evaluation. MNT (20 mg/kg) was more effective in alleviating LPS-induced heart injury when compared with both MNT (10 mg/kg) and DEX (1 mg/kg), as evidenced by decrease in positive staining by TNF-α immunohistochemically, decrease MDA, and increase GSH content in heart tissue. This study demonstrates that MNT might have cardioprotective effects against the inflammatory process during endotoxemia. This effect can be attributed to its antioxidant and/or anti-inflammatory properties. PMID:26089034

  1. Lipopolysaccharide-induced early response genes in bovine peripheral blood mononuclear cells implicate GLG1/E-selectin as a key ligand–receptor interaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study uses a systems biology approach, integrating global gene expression information and knowledge of the regulatory events in cells to identify transcription networks controlling peripheral blood mononuclear cells’ (PBMCs) immune response to lipopolysaccharide (LPS) and to identify the molecu...

  2. Computer Simulation of the Rough Lipopolysaccharide Membrane of Pseudomonas Aeruginosa

    SciTech Connect

    Lins, Roberto D.; Straatsma, TP

    2001-08-01

    Lipopolysaccharides (LPS) form the major constituent of the outer membrane of Gram-negative bacteria, and are believed to play a key role in processes that govern microbial metal binding, microbial adsorption to mineral surfaces, and microbe mediated oxidation/reduction reactions at the bacterial exterior surface. A computational modeling capability is being developed for the study of geochemical reactions at the outer bacterial envelope of Gram-negative bacteria. The understanding of these mechanisms is crucial for the development of successful environmental bioremediation strategies. A molecular model for the rough LPS of Pseudomonas aeruginosa has been designed based on available experimentally determined structural information.

  3. Immunologic activity of lipopolysaccharides released from macrophages after the uptake of intact E coli in vitro

    SciTech Connect

    Duncan, R.L. Jr.; Hoffman, J.; Tesh, V.L.; Morrison, D.C.

    1986-04-15

    Lipopolysaccharides (LPS) have been isolated from culture supernatants and from cell lysates after the in vitro phagocytosis of E. coli by murine macrophages. By using E. coli radiolabeled specifically in the LPS component with (/sup 3/H)galactose, the authors studies have shown that the macrophage-processed LPS is enhanced with respect to its immunostimulatory activity in comparison with control phenol-water-extracted LPS. As assessed by its ability to induce interluekin 1 production in naive macrophages or proliferation in cultures of murine splenocytes, the macrophage-processed LPS is between 10- and 100-fold greater in specific activity. Evidence is presented for both structural and chemical alterations in the LPS macromolecule.

  4. Bacteriophage adhesin-coated long-period gratings for bacterial lipopolysaccharide recognition

    NASA Astrophysics Data System (ADS)

    Koba, Marcin; Śmietana, Mateusz; Brzozowska, Ewa; Górska, Sabina; Mikulic, Predrag; Bock, Wojtek J.

    2014-05-01

    In this work we report an application of the optical fiber long-period gratings (LPGs) working near the dispersion turning point of higher order cladding modes for bacterial lipopolysaccharide (LPS) recognition. We show that when the LPG is functionalized with the bacteriophage adhesin, it is capable of very specific LPS detection. Thus, we compare label-free binding effect for specific to the adhesin LPS-positive and non-specific LPS-negative. The resonance wavelength shift induced by the LPS-positive reaches 2.9 nm, while for LPS-negative the shift is negligible. The LPG-based sensing structure allows for monitoring of the binding phenomenon in real time and with good accuracy.

  5. Antigenic potential of a highly conserved Neisseria meningitidis lipopolysaccharide inner core structure defined by chemical synthesis.

    PubMed

    Reinhardt, Anika; Yang, You; Claus, Heike; Pereira, Claney L; Cox, Andrew D; Vogel, Ulrich; Anish, Chakkumkal; Seeberger, Peter H

    2015-01-22

    Neisseria meningitidis is a leading cause of bacterial meningitis worldwide. We studied the potential of synthetic lipopolysaccharide (LPS) inner core structures as broadly protective antigens against N. meningitidis. Based on the specific reactivity of human serum antibodies to synthetic LPS cores, we selected a highly conserved LPS core tetrasaccharide as a promising antigen. This LPS inner core tetrasaccharide induced a robust IgG response in mice when formulated as an immunogenic glycoconjugate. Binding of raised mouse serum to a broad collection of N. meningitidis strains demonstrated the accessibility of the LPS core on viable bacteria. The distal trisaccharide was identified as the crucial epitope, whereas the proximal Kdo moiety was immunodominant and induced mainly nonprotective antibodies that are responsible for lack of functional protection in polyclonal serum. Our results identified key antigenic determinants of LPS core glycan and, hence, may aid the design of a broadly protective immunization against N. meningitidis. PMID:25601073

  6. The effect of Escherichia coli lipopolysaccharide and Tumor Necrosis Factor alpha on ovarian function

    PubMed Central

    Williams, Erin J.; Sibley, Kelly; Miller, Aleisha N.; Lane, Elizabeth A.; Fishwick, John; Nash, Deborah M.; Herath, Shan; England, Gary CW; Dobson, Hilary; Sheldon, I. Martin

    2009-01-01

    Problem Pelvic inflammatory disease and metritis are important causes of infertility in humans and domestic animals. Uterine infection with Escherichia coli in cattle is associated with reduced ovarian follicle growth and decreased estradiol secretion. We hypothesized that this effect could be mediated by the bacterial lipopolysaccharide (LPS) or cytokines such as tumor necrosis factor alpha (TNFα). Method of study In vitro, bovine ovarian theca and granulosa cells were treated with LPS or TNFα and steroid secretion measured. In vivo, the effect of LPS or TNFα intrauterine infusion was determined by ovarian ultrasonography and measurement of hormones in cattle. Results LPS reduced granulosa cell estradiol secretion, whilst TNFα decreased theca and granulosa cell androstenedione and estradiol production, respectively. In vivo, fewer animals ovulated following intrauterine infusion with LPS or TNFα. Conclusion LPS and TNFα suppress ovarian cell function, supporting the concept that pelvic inflammatory disease and metritis are detrimental for bovine ovarian health. PMID:19238751

  7. Deletion of Ovarian Hormones Induces a Sickness Behavior in Rats Comparable to the Effect of Lipopolysaccharide

    PubMed Central

    Azizi-Malekabadi, Hamid; Hosseini, Mahmoud; Pourganji, Masoume; Zabihi, Hoda; Saeedjalali, Mohsen; Anaeigoudari, Akbar

    2015-01-01

    Neuroimmune factors have been proposed as the contributors to the pathogenesis of sickness behaviors. The effects of female gonadal hormones on both neuroinflammation and depression have also been well considered. In the present study, the capability of deletion of ovarian hormones to induce sickness-like behaviors in rats was compared with the effect lipopolysaccharide (LPS). The groups were including Sham, OVX, Sham-LPS, and OVX-LPS. The Sham-LPS and OVX-LPS groups were treated with LPS (250 μg/kg) two hours before conducting the behavioral tests. In the forced swimming (FST), the immobility times in both OVX and Sham-LPS groups were higher than that of Sham (P < 0.001). In open-field (OP) test, the central crossing number by OVX and Sham-LPS groups were lower than Sham (P < 0.001) while there were no significant differences between OVX-LPS and OVX groups. In elevated plus maze (EPM), the percent of entries to the open arm by both OVX and Sham-LPS groups was lower than that of Sham group (P < 0.001). The results of present study showed that deletion of ovarian hormones induced sickness behaviors in rats which were comparable to the effects of LPS. Moreover, further investigations are required in order to better understand the mechanism(s) involved. PMID:25705518

  8. Alkaline Phosphatase Protects Lipopolysaccharide-Induced Early Pregnancy Defects in Mice

    PubMed Central

    Lei, Wei; Ni, Hua; Herington, Jennifer; Reese, Jeff; Paria, Bibhash C.

    2015-01-01

    Excessive cytokine inflammatory response due to chronic or superphysiological level of microbial infection during pregnancy leads to pregnancy complications such as early pregnancy defects/loss and preterm birth. Bacterial toxin lipopolysaccharide (LPS), long recognized as a potent proinflammatory mediator, has been identified as a risk factor for pregnancy complications. Alkaline phosphatase (AP) isozymes have been shown to detoxify LPS by dephosphorylation. In this study, we examined the role of alkaline phosphatase (AP) in mitigating LPS-induced early pregnancy complications in mice. We found that 1) the uterus prior to implantation and implantation sites following embryo implantation produce LPS recognition and dephosphorylation molecules TLR4 and tissue non-specific AP (TNAP) isozyme, respectively; 2) uterine TNAP isozyme dephosphorylates LPS at its sites of production; 3) while LPS administration following embryo implantation elicits proinflammatory cytokine mRNA levels at the embryo implantation sites (EISs) and causes early pregnancy loss, dephosphorylated LPS neither triggers proinflammatory cytokine mRNA levels at the EISs nor induces pregnancy complications; 4) AP isozyme supplementation to accelerate LPS detoxification attenuates LPS-induced pregnancy complications following embryo implantation. These findings suggest that a LPS dephosphorylation strategy using AP isozyme may have a unique therapeutic potential to mitigate LPS- or Gram-negative bacteria-induced pregnancy complications in at-risk women. PMID:25910276

  9. Lipopolysaccharide Is Cleared from the Circulation by Hepatocytes via the Low Density Lipoprotein Receptor

    PubMed Central

    Topchiy, Elena; Cirstea, Mihai; Kong, HyeJin Julia; Boyd, John H.; Wang, Yingjin; Russell, James A.; Walley, Keith R.

    2016-01-01

    Sepsis is the leading cause of death in critically ill patients. While decreased Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) function improves clinical outcomes in murine and human sepsis, the mechanisms involved have not been fully elucidated. We tested the hypothesis that lipopolysaccharide (LPS), the major Gram-negative bacteria endotoxin, is cleared from the circulation by hepatocyte Low Density Lipoprotein Receptors (LDLR)—receptors downregulated by PCSK9. We directly visualized LPS uptake and found that LPS is rapidly taken up by hepatocytes into the cell periphery. Over the course of 4 hours LPS is transported towards the cell center. We next found that clearance of injected LPS from the blood was reduced substantially in Ldlr knockout (Ldlr-/-) mice compared to wild type controls and, simultaneously, hepatic uptake of LPS was also reduced in Ldlr-/- mice. Specifically examining the role of hepatocytes, we further found that primary hepatocytes isolated from Ldlr-/- mice had greatly decreased LPS uptake. In the HepG2 immortalized human hepatocyte cell line, LDLR silencing similarly resulted in decreased LPS uptake. PCSK9 treatment reduces LDLR density on hepatocytes and, therefore, was another independent strategy to test our hypothesis. Incubation with PCSK9 reduced LPS uptake by hepatocytes. Taken together, these findings demonstrate that hepatocytes clear LPS from the circulation via the LDLR and PCSK9 regulates LPS clearance from the circulation during sepsis by downregulation of hepatic LDLR. PMID:27171436

  10. Orally administered melatonin prevents lipopolysaccharide-induced neural tube defects in mice.

    PubMed

    Fu, Lin; Yu, Zhen; Chen, Yuan-Hua; Xia, Mi-Zhen; Wang, Hua; Zhang, Cheng; Tao, Fang-Biao; Xu, De-Xiang

    2014-01-01

    Lipopolysaccharide (LPS) has been associated with adverse pregnant outcomes, including fetal demise, intra-uterine growth restriction (IUGR), neural tube defects (NTDs) and preterm delivery in rodent animals. Previous studies demonstrated that melatonin protected against LPS-induced fetal demise, IUGR and preterm delivery. The aim of the present study was to investigate the effects of melatonin on LPS-induced NTDs. All pregnant mice except controls were intraperitoneally injected with LPS (25 µg/kg) daily from gestational day (GD)8 to GD12. Some pregnant mice were orally administered with melatonin (MT, 50 mg/kg) before each LPS injection. A five-day LPS injection resulted in 27.5% of fetuses with anencephaly, exencephaly or encephalomeningocele. Additional experiment showed that maternal LPS exposure significantly down-regulated placental proton-coupled folate transporter (pcft) and disturbed folate transport from maternal circulation through the placentas into the fetus. Interestingly, melatonin significantly attenuated LPS-induced down-regulation of placental pcft. Moreover, melatonin markedly improved the transport of folate from maternal circulation through the placentas into the fetus. Correspondingly, orally administered melatonin reduced the incidence of LPS-induced anencephaly, exencephaly or encephalomeningocele. Taken together, these results suggest that orally administered melatonin prevents LPS-induced NTDs through alleviating LPS-induced disturbance of folate transport from maternal circulation through the placenta into the fetus. PMID:25420102

  11. Cell-surface nucleolin is involved in lipopolysaccharide internalization and signalling in alveolar macrophages.

    PubMed

    Wang, Yi; Mao, Mei; Xu, Jian-cheng

    2011-07-01

    C23 (nucleolin) shuttling between the nucleus, cytoplasm and cell surface has been implicated in controlling regulatory processes and may play a role in pathogen infection and autoimmune diseases. It has been reported that cell surface-expressed C23 on THP-1 monocytes is involved in the inflammatory response induced by LPS (lipopolysaccharide). This study investigates whether C23 is a membrane receptor for LPS during LPS-induced AMs (alveolar macrophages) activation. First, using immunofluorescence and microscopy, we detected the expression of C23 on the surface of AMs. Second, using LPS affinity columns, we demonstrated that C23 directly binds to LPS. Third, we found that LPS colocalized with C23 on both the cell surface and in the cytoplasm. Finally, knockdown of C23 expression on the cell surface using siRNA (small interfering RNA) led to significant reductions in the internalization of LPS, in LPS-induced NF-κB (nuclear factor κB)-DNA binding and in the protein expression of TNF (tumour necrosis factor)-α and IL-6 (interleukin-6). These findings provide evidence that cell-surface C23 on AMs may serve as a receptor for LPS and are essential for internalization and transport of LPS. Furthermore, C23 participates in the regulation of LPS-induced inflammation of AMs, which indicates that cell-surface C23 is a new and promising therapeutic target for the treatment of bacterial infections. PMID:21309751

  12. Neonatal lipopolysaccharide exposure does not diminish the innate immune response to a subsequent lipopolysaccharide challenge in Holstein bull calves.

    PubMed

    Benjamin, A L; Korkmaz, F T; Elsasser, T H; Kerr, D E

    2016-07-01

    The innate immune response following experimental mastitis is quite variable between individual dairy cattle. An inflammatory response that minimizes collateral damage to the mammary gland while still effectively resolving the infection following pathogen exposure is beneficial to dairy producers. The ability of a lipopolysaccharide (LPS) exposure in early life to generate a low-responding phenotype and thus reduce the inflammatory response to a later-life LPS challenge was investigated in neonatal bull calves. Ten Holstein bull calves were randomly assigned to either an early life LPS (ELL) group (n=5) or an early life saline (ELS) group (n=5). At 7d of age, calves received either LPS or saline, and at 32d of age, all calves were challenged with an intravenous dose of LPS to determine the effect of the early life treatment (LPS or saline) on the immune response generated toward a subsequent LPS challenge. Dermal fibroblast and monocyte-derived macrophage cultures from each calf were established at age 20 and 27d, respectively, to model sustained effects from the early life LPS exposure on gene expression and protein production of components within the LPS response pathway. The ELL calves had greater levels of plasma IL-6 and tumor necrosis factor-α than the ELS calves following the early life LPS or saline treatments. However, levels of these 2 immune markers were similar between ELL and ELS calves when both groups were subsequently challenged with LPS. A comparison of the in vitro LPS responses of the ELL and ELS calves revealed similar patterns of protein production and gene expression following an LPS challenge of both dermal fibroblast and monocyte-derived macrophage cultures established from the treatment groups. Whereas an early life exposure to LPS did not result in a dampened inflammatory response toward a later LPS challenge in these neonatal bull calves, the potential that exposure to inflammation or stress in early life or in utero can create an

  13. Inhibition of Neuroinflammation in LPS-Activated Microglia by Cryptolepine

    PubMed Central

    Olajide, Olumayokun A.; Bhatia, Harsharan S.; de Oliveira, Antonio C. P.; Wright, Colin W.; Fiebich, Bernd L.

    2013-01-01

    Cryptolepine, an indoloquinoline alkaloid in Cryptolepis sanguinolenta, has anti-inflammatory property. In this study, we aimed to evaluate the effects of cryptolepine on lipopolysaccharide (LPS)- induced neuroinflammation in rat microglia and its potential mechanisms. Microglial activation was induced by stimulation with LPS, and the effects of cryptolepine pretreatment on microglial activation and production of proinflammatory mediators, PGE2/COX-2, microsomal prostaglandin E2 synthase and nitric oxide/iNOS were investigated. We further elucidated the role of Nuclear Factor-kappa B (NF-κB) and the mitogen-activated protein kinases in the antiinflammatory actions of cryptolepine in LPS-stimulated microglia. Our results showed that cryptolepine significantly inhibited LPS-induced production of tumour necrosis factor-alpha (TNFα), interleukin-6 (IL-6), interleukin-1beta (IL-1β), nitric oxide, and PGE2. Protein and mRNA levels of COX-2 and iNOS were also attenuated by cryptolepine. Further experiments on intracellular signalling mechanisms show that IκB-independent inhibition of NF-κB nuclear translocation contributes to the anti-neuroinflammatory actions of cryptolepine. Results also show that cryptolepine inhibited LPS-induced p38 and MAPKAPK2 phosphorylation in the microglia. Cell viability experiments revealed that cryptolepine (2.5 and 5 μM) did not produce cytotoxicity in microglia. Taken together, our results suggest that cryptolepine inhibits LPS-induced microglial inflammation by partial targeting of NF-κB signalling and attenuation of p38/MAPKAPK2. PMID:23737832

  14. Lipopolysaccharide deacylation by an endogenous lipase controls innate antibody responses to Gram-negative bacteria.

    PubMed

    Lu, Mingfang; Zhang, Mei; Takashima, Akira; Weiss, Jerrold; Apicella, Michael A; Li, Xiang-Hong; Yuan, Dorothy; Munford, Robert S

    2005-10-01

    T cell-independent type 1 agonists such as Gram-negative bacterial lipopolysaccharides can stimulate B lymphocytes to proliferate and produce antibodies by signaling through Toll-like receptors. This phenomenon is well established in vitro, yet polyclonal B cell responses after bacterial infection in vivo are often weak and short-lived. We show here that B cell proliferation and polyclonal antibody production in response to Gram-negative bacterial infection are modulated by acyloxyacyl hydrolase, a host enzyme that deacylates bacterial lipopolysaccharides. Deacylation of lipopolysaccharide occurred over several days, allowing lipopolysaccharide to act as an innate immune stimulant yet limiting the eventual amount of B cell proliferation and polyclonal antibody production. Control of lipopolysaccharide activation by acyloxyacyl hydrolase indicates that mammals can regulate immune responses to bacterial infection by chemical modification of a Toll-like receptor agonist. PMID:16155573

  15. Preservation of Renal Blood Flow by the Antioxidant EUK-134 in LPS-Treated Pigs

    PubMed Central

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

    2015-01-01

    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. PMID:25815596

  16. Protective effect of carbon monoxide pre-conditioning on LPS-induced endothelial cell stress

    PubMed Central

    Zannoni, Augusta; Bacci, Maria Laura; Forni, Monica

    2009-01-01

    Increasing evidence indicates that carbon monoxide (CO) may protect against several diseases including sepsis. The ability of CO pre-treatment to provide good pre-conditioning against lipopolysaccharide (LPS)-induced injury was tested using an in vitro model of primary culture of porcine aortic endothelial cells (pAEC). pAEC were exposed to CO (250 ppm) or air for 1 h prior to the addition of LPS (10 μg/ml). Hsp70, HO-1, and Egr-1 protein levels were determined as well as vascular endothelial growth factor (VEGF) secretion after 4, 7, and 15 h. The effect of CO on LPS-induced apoptosis was also detected at 15 h. CO pre-treatment before the addition of LPS, significantly reduced LPS-induced apoptosis. LPS induced an increase in the level of VEGF in culture media after 7 and 15 h, and a larger increase was detected in CO pre-treated cells. In addition, CO pre-treatment reduced LPS-induced Hsp70, HO-1, and Egr-1 protein expression. In conclusion, CO treatment seems to provide a good pre-conditioning for the prevention of LPS-induced endothelial injury. PMID:19693705

  17. Gram-negative trimeric porins have specific LPS binding sites that are essential for porin biogenesis.

    PubMed

    Arunmanee, Wanatchaporn; Pathania, Monisha; Solovyova, Alexandra S; Le Brun, Anton P; Ridley, Helen; Baslé, Arnaud; van den Berg, Bert; Lakey, Jeremy H

    2016-08-23

    The outer membrane (OM) of gram-negative bacteria is an unusual asymmetric bilayer with an external monolayer of lipopolysaccharide (LPS) and an inner layer of phospholipids. The LPS layer is rigid and stabilized by divalent cation cross-links between phosphate groups on the core oligosaccharide regions. This means that the OM is robust and highly impermeable to toxins and antibiotics. During their biogenesis, OM proteins (OMPs), which function as transporters and receptors, must integrate into this ordered monolayer while preserving its impermeability. Here we reveal the specific interactions between the trimeric porins of Enterobacteriaceae and LPS. Isolated porins form complexes with variable numbers of LPS molecules, which are stabilized by calcium ions. In earlier studies, two high-affinity sites were predicted to contain groups of positively charged side chains. Mutation of these residues led to the loss of LPS binding and, in one site, also prevented trimerization of the porin, explaining the previously observed effect of LPS mutants on porin folding. The high-resolution X-ray crystal structure of a trimeric porin-LPS complex not only helps to explain the mutagenesis results but also reveals more complex, subtle porin-LPS interactions and a bridging calcium ion. PMID:27493217

  18. Effects of exendin-4, a glucagon like peptide-1 receptor agonist, on neutrophil count and inflammatory cytokines in a rat model of endotoxemia

    PubMed Central

    Yanay, Ofer; Bailey, Adam L; Kernan, Kelly; Zimmerman, Jerry J; Osborne, William R

    2015-01-01

    Background Sepsis remains a major cause of morbidity and mortality. A variety of strategies targeting modulation of the pro-inflammatory response associated with early sepsis have been reported without clinical success. GLP-1 enhances glucose-stimulated insulin secretion. In addition, it was shown to have anti-inflammatory effects. We hypothesized that treatment with exendin-4, a GLP-1 receptor agonist, would attenuate inflammation and improve glucose control in a lipopolysaccharide (LPS) rat model of inflammation. Methods Two-month-old male Wistar rats were randomly assigned to one of the following four groups: 1) treatment: intraperitoneal (IP) injection of LPS 10 mg/kg followed by exendin-4, 30 μg/kg, 10 minutes later; 2) control-1: IP injection of LPS 10 mg/kg, followed by normal saline (NS); 3) control-2: IP NS injection followed by exendin-4; 4) sham: IP injection of NS followed by another NS injection. Glucose concentration, total white blood count with absolute neutrophil count, and pro- and anti-inflammatory cytokine concentrations were measured at 0, 3, 6, and 10 hours following LPS injection. Results At 3 hours, rats injected with LPS developed neutropenia, elevated pro- and anti-inflammatory cytokines, and mild hypoglycemia. Treatment with exendin-4 significantly modulated neutropenia, and decreased pro-inflammatory cytokine concentrations (IL-1α, IL-1β, IL-6, TNFα, and IFNγ). However, exendin-4 had no effect on IL-10 concentrations. LPS injection led to mild hypoglycemia, that was not observed in rats treated with exendin-4. Sham animals exhibited no significant change from baseline in all parameters. Conclusion In this LPS model of acute early phase inflammation, treatment with exendin-4 decreased pro-inflammatory cytokine concentrations without changing IL-10 blood levels and improved neutropenia. Following LPS injection, rats developed a tendency toward hypoglycemia that improved with exendin-4. Overall our data suggest that exogenous exendin-4

  19. Systemic LPS Causes Chronic Neuroinflammation and Progressive Neurodegeneration

    PubMed Central

    Qin, Liya; Wu, Xuefei; Block, Michelle L.; Liu, Yuxin; Breese, George R.; Hong, Jau-Shyong; Knapp, Darin J.; Crews, Fulton T.

    2010-01-01

    Inflammation is implicated in the progressive nature of neurodegenerative diseases, such as Parkinson's disease, but the mechanisms are poorly understood. A single systemic lipopolysaccharide (LPS, 5 mg/kg, i.p.) or tumor necrosis factor alpha (TNFα, 0.25 mg/kg, i.p.) injection was administered in adult wild-type mice and in mice lacking TNFα receptors (TNF R1/R2−/−) to discern the mechanisms of inflammation transfer from the periphery to the brain and the neurodegenerative consequences. Systemic LPS administration resulted in rapid brain TNFα increase that remained elevated for 10 months, while peripheral TNFα (serum and liver) had subsided by 9 h (serum) and 1 week (liver). Systemic TNFα and LPS administration activated microglia and increased expression of brain pro-inflammatory factors (i.e., TNFα, MCP-1, IL-1β, and NF-κB p65) in wild-type mice, but not in TNF R1/R2−/− mice. Further, LPS reduced the number of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra (SN) by 23% at 7-months post-treatment, which progressed to 47% at 10 months. Together, these data demonstrate that through TNFα, peripheral inflammation in adult animals can: (1) activate brain microglia to produce chronically elevated pro-inflammatory factors; (2) induce delayed and progressive loss of DA neurons in the SN. These findings provide valuable insight into the potential pathogenesis and self-propelling nature of Parkinson's disease. PMID:17203472

  20. LPS induces pulp progenitor cell recruitment via complement activation.

    PubMed

    Chmilewsky, F; Jeanneau, C; Laurent, P; About, I

    2015-01-01

    Complement system, a major component of the natural immunity, has been recently identified as an important mediator of the dentin-pulp regeneration process through STRO-1 pulp cell recruitment by the C5a active fragment. Moreover, it has been shown recently that under stimulation with lipoteichoic acid, a complex component of the Gram-positive bacteria cell wall, human pulp fibroblasts are able to synthesize all proteins required for complement activation. However, Gram-negative bacteria, which are also involved in tooth decay, are known as powerful activators of complement system and inflammation. Here, we investigated the role of Gram-negative bacteria-induced complement activation on the pulp progenitor cell recruitment using lipopolysaccharide (LPS), a major component of all Gram-negative bacteria. Our results show that incubating pulp fibroblasts with LPS induced membrane attack complex formation and C5a release in serum-free fibroblast cultures. The produced C5a binds to the pulp progenitor cells' membrane and induces their migration toward the LPS stimulation chamber, as revealed by the dynamic transwell migration assays. The inhibition of this migration by the C5aR-specific antagonist W54011 indicates that the pulp progenitor migration is mediated by the interaction between C5a and C5aR. Our findings demonstrate, for the first time, a direct interaction between the recruitment of progenitor pulp cells and the activation of complement system generated by pulp fibroblast stimulation with LPS. PMID:25359783

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

    PubMed

    Biedroń, Rafał; Peruń, Angelika; Józefowski, Szczepan

    2016-01-01

    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 immunity. PMID

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

    PubMed Central

    Biedroń, Rafał; Peruń, Angelika; Józefowski, Szczepan

    2016-01-01

    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 immunity. PMID

  3. Characterization of a rabbit cationic protein (CAP18) with lipopolysaccharide-inhibitory activity.

    PubMed Central

    Hirata, M; Shimomura, Y; Yoshida, M; Morgan, J G; Palings, I; Wilson, D; Yen, M H; Wright, S C; Larrick, J W

    1994-01-01

    Cationic antibacterial proteins (CAP) were purified from rabbit granulocytes, and the effects of CAP on lipopolysaccharide (LPS)-induced tissue factor generation by murine peritoneal macrophages and human blood monocytes were studied. CAP were purified from rabbit peritoneal leukocytes by using as an assay the agglutination of erythrocytes coated with Re-LPS. Two proteins with CAP activity, CAP18 (18 kDa) and CAP7 (7 kDa), were isolated by acid extraction, ethanol precipitation, affinity chromatography, gel filtration, and reverse-phase high-pressure liquid chromatography. On the basis of protein sequencing, CAP7 was identified as the C-terminal fragment of CAP18, designated CAP18(106-142). Various forms of LPS (S-LPS, Re-LPS, and lipid A) activate murine macrophages and human blood monocytes to generate tissue factor (tissue thromboplastin). Incubation of LPS for 18 h with partially purified CAP (heparin-Sepharose fraction) inhibited the capacity of LPS to induce tissue factor; however, purified CAP18 inhibited about 75% of the activity of S-LPS after 1 h of incubation. CAP more effectively inhibited S-LPS than Re-LPS or lipid A. Synthetic CAP18(106-142) inhibited LPS-induced tissue factor generation by murine macrophages. CAP18(106-142) has greater LPS-binding and LPS-neutralizing activities than CAP18. We hypothesize that CAP18 and the derivative peptide, CAP18(106-142), bind to LPS and alter the capacity of LPS to initiate disseminated intravascular coagulation. In this regard, CAP may have therapeutic potential for sepsis and endotoxin shock. Images PMID:8132348

  4. The effects of L-arginine on spatial memory and synaptic plasticity impairments induced by lipopolysaccharide

    PubMed Central

    Anaeigoudari, Akbar; Shafei, Mohammad Naser; Soukhtanloo, Mohammad; Sadeghnia, Hamid Reza; Reisi, Parham; Nosratabadi, Reza; Behradnia, Sepehr; Hosseini, Mahmoud

    2015-01-01

    Background: An important role of nitric oxide (NO) in neuroinflammation has been suggested. It is also suggested that NO has a critical role in learning and memory. Neuro-inflammation induced by lipopolysaccharide (LPS) has been reported that deteriorates learning and memory. The effect of L-arginine (LA) as a precursor of NO on LPS-induced spatial learning and memory and neuronal plasticity impairment was evaluated. Materials and Methods: The animals were grouped into: (1) Control, (2) LPS, (3) LA-LPS, and (4) LA. The rats received intraperitoneally LPS (1 mg/kg) 2 h before experiments and LA (200 mg/kg) 30 min before LPS. The animals were examined in Morris water maze (MWM). Long-term potentiation (LTP) from CA1 area of the hippocampus was also assessed by 100 Hz stimulation in the ipsilateral Schaffer collateral pathway. Results: In MWM, time latency and traveled path were higher in LPS group than the control group (P < 0.001) whereas in LA-LPS group they were shorter than LPS group (P < 0.001). The amplitude and slope of field excitatory postsynaptic potential (fEPSP) decreased in LPS group compared to control group (P < 0.05 and P < 0.01) whereas, there was not any significant difference in these parameters between LPS and LA-LPS groups. Conclusion: Administration of LPS impaired spatial memory and synaptic plasticity. Although LA ameliorated deleterious effects of LPS on learning of spatial tasks, it could not restore LPS-induced LTP impairment. PMID:26601090

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

    PubMed Central

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

    2015-01-01

    Background: Brucella abortus RB51 is a rough stable mutant strain, which has been widely used as a live vaccine for prevention of brucellosis in cattle instead of B. abortus strain S19. B. abortus lipopolysaccharide (LPS) has unique properties in comparison to other bacterial LPS. Objectives: In the current study, two types of LPS, smooth (S-LPS) and rough (R-LPS) were purified from B. abortus S19 and RB51, respectively. The aim of this study was to evaluate biological and immunological properties of purified LPS as an immunogenical determinant. Materials and Methods: Primarily, S19 and RB51 LPS were extracted and purified by two different modifications of the phenol water method. The final purity of LPS was determined by chemical analysis (2-keto-3-deoxyoctonate (KDO), glycan, phosphate and protein content) and different staining methods, following sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). C57BL/6 mice were immunized subcutaneously three times at biweekly intervals with the same amount of purified LPSs. The humoral immunity was evaluated by measuring specific IgG levels and also different cytokine levels, such as IFN-γ, TNF-α, IL-4 and IL-10, were determined for assessing T-cell immune response. Results: Biochemical analysis data and SDS-PAGE profile showed that the chemical nature of S19 LPS is different from RB51 LPS. Both S and R-LPS induce an immune response. T-cell immune response induced by both S and R-LPS had almost the same pattern whereas S19 LPS elicited humoral immunity, which was higher than RB51 LPS. Conclusions: Purified LPS can be considered as a safe adjuvant and can be used as a component in prophylactic and therapeutic vaccines targeting infectious disease, cancer and allergies. PMID:26862376

  6. Characterization of the lipopolysaccharide from a Rhizobium phaseoli mutant that is defective in infection thread development.

    PubMed Central

    Carlson, R W; Kalembasa, S; Turowski, D; Pachori, P; Noel, K D

    1987-01-01

    The lipopolysaccharide (LPS) from a Rhizobium phaseoli mutant, CE109, was isolated and compared with that of its wild-type parent, CE3. A previous report has shown that the mutant is defective in infection thread development, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that it has an altered LPS (K. D. Noel, K. A. VandenBosch, and B. Kulpaca, J. Bacteriol. 168:1392-1462, 1986). Mild acid hydrolysis of the CE3 LPS released a polysaccharide and an oligosaccharide, PS1 and PS2, respectively. Mild acid hydrolysis of CE109 LPS released only an oligosaccharide. Chemical and immunochemical analyses showed that CE3-PS1 is the antigenic O chain of this strain and that CE109 LPS does not contain any of the major sugar components of CE3-PS1. CE109 oligosaccharide was identical in composition to CE3-PS2. The lipid A's from both strains were very similar in composition, with only minor quantitative variations. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of CE3 and CE109 LPSs showed that CE3 LPS separated into two bands, LPS I and LPS II, while CE109 had two bands which migrated to positions similar to that of LPS II. Immunoblotting with anti-CE3 antiserum showed that LPS I contains the antigenic O chain of CE3, PS1. Anti-CE109 antiserum interacted strongly with both CE109 LPS bands and CE3 LPS II and interacted weakly with CE3 LPS I. Mild-acid hydrolysis of CE3 LPS I, extracted from the polyacrylamide gel, showed that it contained both PS1 and PS2. The results in this report showed that CE109 LPS consists of only the lipid A core and is missing the antigenic O chain. Images PMID:3667520

  7. Moesin Functions as a Lipopolysaccharide Receptor on Human Monocytes

    PubMed Central

    Tohme, Ziad N.; Amar, Salomon; Van Dyke, Thomas E.

    1999-01-01

    Bacterial endotoxin (lipopolysaccharide [LPS]), a glycolipid found in the outer membranes of gram-negative bacteria, induces the secretion of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), and IL-6 by monocytes/macrophages. The secretion of these biologically active compounds leads to multiple pathological conditions, such as septic shock. There is substantial evidence that chronic exposure to LPS mediates, at least in part, the tissue destruction associated with gram-negative infection. CD14, a 55-kDa protein, has been identified as an LPS receptor. In conjunction with a serum protein, LPS binding protein (LBP), LPS-CD14 interactions mediate many LPS functions in the inflammatory response. However, CD14 lacks a cytoplasmic domain, or any known signal transduction sequence motif, suggesting the existence of another cell surface domain capable of transducing signals. In this paper, we report a second, CD14-independent LPS binding site, which, based on biological activity, appears to be a functional LPS receptor. Cross-linking experiments were performed to identify LPS binding sites. Two molecules were identified: a 55-kDa protein (CD14) and a second, 78-kDa band. Sequencing of the 78-kDa protein by mass spectroscopic analysis revealed 100% homology with moesin (membrane-organizing extension spike protein). Antibody to CD14 induced partial blocking of the LPS response. However, antimoesin monoclonal antibody completely blocked the LPS-induced TNF-α response in human monocytes, without blocking CD14 binding of LPS. Irrelevant isotype controls had no effect. Additional experiments were performed to evaluate the specificity of the antimoesin blocking. Separate experiments evaluated antimoesin effects on monocyte chemotaxis, IL-1 production in response to IL-1 stimulation, and TNF-α secretion in response to Staphylococcus aureus stimulation. Antimoesin blocked only LPS-mediated events. The data suggest that moesin

  8. Lipopolysaccharides of Actinobacillus pleuropneumoniae bind pig hemoglobin.

    PubMed Central

    Bélanger, M; Bégin, C; Jacques, M

    1995-01-01

    A previous study indicated that lipopolysaccharides (LPS) extracted from Actinobacillus pleuropneumoniae bind two low-molecular-mass proteins, of approximately 10 and 11 kDa, present in porcine respiratory tract secretions (M. Bélanger, D. Dubreuil, and M. Jacques, Infect. Immun. 62:868-873, 1994). In the present study, we determined the N-terminal amino acid sequences of these two proteins, which revealed high homology with the alpha and beta chains of pig hemoglobin. Some isolates of A. pleuropneumoniae were able to use hemoglobin from various animal species as well as other heme compounds as sole sources of iron for growth, while other isolates were unable to use them. Immunoelectron microscopy showed binding of pig hemoglobin at the surface of all A. pleuropneumoniae isolates as well as labeling of outer membrane blebs. We observed, using Western blotting (immunoblotting), that the lipid A-core region of LPS of all isolates was binding pig hemoglobin. Furthermore, lipid A obtained after acid hydrolysis of LPS extracted from A. pleuropneumoniae was able to bind pig hemoglobin and this binding was completely abolished by preincubation of lipid A with polymyxin B but was not inhibited by preincubation with glucosamines. Fatty acids constituting the lipid A of A. pleuropneumoniae, namely, dodecanoic acid, tetradecanoic acid, 3-hydroxytetradecanoic acid, hexadecanoic acid, and octadecanoic acid, were also binding pig hemoglobin. Our results indicate that LPS of all A. pleuropneumoniae isolates tested bind pig hemoglobin and that lipid A is involved in this binding. Our results also indicate that some A. pleuropneumoniae isolates are, in addition, able to use hemoglobin for growth. Binding of hemoglobin to LPS might represent an important means by which A. pleuropneumoniae acquires iron in vivo from hemoglobin released from erythrocytes lysed by the action of its hemolysins. PMID:7822035

  9. Deletion of Monoglyceride Lipase in Astrocytes Attenuates Lipopolysaccharide-induced Neuroinflammation.

    PubMed

    Grabner, Gernot F; Eichmann, Thomas O; Wagner, Bernhard; Gao, Yuanqing; Farzi, Aitak; Taschler, Ulrike; Radner, Franz P W; Schweiger, Martina; Lass, Achim; Holzer, Peter; Zinser, Erwin; Tschöp, Matthias H; Yi, Chun-Xia; Zimmermann, Robert

    2016-01-01

    Monoglyceride lipase (MGL) is required for efficient hydrolysis of the endocannabinoid 2-arachidonoylglyerol (2-AG) in the brain generating arachidonic acid (AA) and glycerol. This metabolic function makes MGL an interesting target for the treatment of neuroinflammation, since 2-AG exhibits anti-inflammatory properties and AA is a precursor for pro-inflammatory prostaglandins. Astrocytes are an important source of AA and 2-AG, and highly express MGL. In the present study, we dissected the distinct contribution of MGL in astrocytes on brain 2-AG and AA metabolism by generating a mouse model with genetic deletion of MGL specifically in astrocytes (MKO(GFAP)). MKO(GFAP) mice exhibit moderately increased 2-AG and reduced AA levels in brain. Minor accumulation of 2-AG in the brain of MKO(GFAP) mice does not cause cannabinoid receptor desensitization as previously observed in mice globally lacking MGL. Importantly, MKO(GFAP) mice exhibit reduced brain prostaglandin E2 and pro-inflammatory cytokine levels upon peripheral lipopolysaccharide (LPS) administration. These observations indicate that MGL-mediated degradation of 2-AG in astrocytes provides AA for prostaglandin synthesis promoting LPS-induced neuroinflammation. The beneficial effect of astrocyte-specific MGL-deficiency is not fully abrogated by the inverse cannabinoid receptor 1 agonist SR141716 (Rimonabant) suggesting that the anti-inflammatory effects are rather caused by reduced prostaglandin synthesis than by activation of cannabinoid receptors. In conclusion, our data demonstrate that MGL in astrocytes is an important regulator of 2-AG levels, AA availability, and neuroinflammation. PMID:26565024

  10. Interaction between Leptospiral Lipopolysaccharide and Toll-like Receptor 2 in Pig Fibroblast Cell Line, and Inhibitory Effect of Antibody against Leptospiral Lipopolysaccharide on Interaction

    PubMed Central

    Guo, Yijie; Fukuda, Tomokazu; Nakamura, Shuichi; Bai, Lanlan; Xu, Jun; Kuroda, Kengo; Tomioka, Rintaro; Yoneyama, Hiroshi; Isogai, Emiko

    2015-01-01

    Leptospiral lipopolysaccharide (L-LPS) has shown potency in activating toll-like receptor 2 (TLR2) in pig fibroblasts (PEFs_NCC1), and causes the expression of proinflammatory cytokines. However, the stimulation by L-LPS was weak eliciting the function of TLR2 sufficiently in pig innate immunity responses during Leptospira infection. In this study, the immune response of pig embryonic fibroblast cell line (PEFs_SV40) was investigated and was found to be the high immune response, thus TLR2 is the predominate receptor of L-LPS in pig cells. Further, we found a strategy using the antibody against L-LPS, to prevent L-LPS interaction with TLR2 in pig cells which could impact on immune activation. PMID:25557825

  11. TIMAP protects endothelial barrier from LPS-induced vascular leakage and is down-regulated by LPS

    PubMed Central

    Poirier, Christophe; Gorshkov, Boris A.; Zemskova, Marina A.; Bogatcheva, Natalia V.; Verin, Alexander D.

    2011-01-01

    TIMAP is a regulatory subunit of protein phosphatase 1, whose role remains largely unknown. Our recent data suggested that TIMAP is involved in the regulation of barrier function in cultured pulmonary endothelial monolayers (Csortos et al., Am J Physiol Lung Cell Mol Physiol 295: L440-450, 2008). Here we showed that TIMAP depletion exacerbates lipopolysaccharide (LPS)-induced vascular leakage in murine lung, suggesting that TIMAP has a barrier-protective role in vivo. Real-Time RT PCR analysis revealed that treatment with LPS significantly suppressed Timap mRNA level. This suppression was not achieved via the down-regulation of Timap promoter activity, suggesting that LPS decreased Timap mRNA stability. Pretreatment with protein kinase A (PKA) inhibitor H-89 reduced TIMAP mRNA level, whereas pretreatment with PKA activator, bnz-cAMP, increased this level and attenuated LPS-induced decrease in TIMAP mRNA. Altogether, these data confirmed the barrier-protective role of TIMAP and suggested that barrier-disruptive and barrier-protective agents may employ modulation of TIMAP expression as a mechanism affecting barrier permeability. PMID:21907835

  12. Usefulness of ELISA Methods for Assessing LPS Interactions with Proteins and Peptides

    PubMed Central

    Martínez-Sernández, Victoria; Orbegozo-Medina, Ricardo A.; Romarís, Fernanda; Paniagua, Esperanza; Ubeira, Florencio M.

    2016-01-01

    Lipopolysaccharide (LPS), the major constituent of the outer membrane of Gram-negative bacteria, can trigger severe inflammatory responses during bacterial infections, possibly leading to septic shock. One approach to combatting endotoxic shock is to neutralize the most conserved part and major mediator of LPS activity (lipid A) with LPS-binding proteins or peptides. Although several available assays evaluate the biological activity of these molecules on LPS (e.g. inhibition of LPS-induced TNF-α production in macrophages), the development of simple and cost-effective methods that would enable preliminary screening of large numbers of potential candidate molecules is of great interest. Moreover, it would be also desirable that such methods could provide information about the possible biological relevance of the interactions between proteins and LPS, which may enhance or neutralize LPS-induced inflammatory responses. In this study, we designed and evaluated different types of ELISA that could be used to study possible interactions between LPS and any protein or peptide. We also analysed the usefulness and limitations of the different ELISAs. Specifically, we tested the capacity of several proteins and peptides to bind FITC-labeled LPSs from Escherichia coli serotypes O111:B4 and O55:B5 in an indirect ELISA and in two competitive ELISAs including casein hydrolysate (hCAS) and biotinylated polymyxin B (captured by deglycosylated avidin; PMX) as LPS-binding agents in the solid phase. We also examined the influence of pH, detergents and different blocking agents on LPS binding. Our results showed that the competitive hCAS-ELISA performed under mildly acidic conditions can be used as a general method for studying LPS interactions, while the more restrictive PMX-ELISA may help to identify proteins/peptides that are likely to have neutralizing properties in vitro or in vivo. PMID:27249227

  13. LPS-Stimulated Human Skin-Derived Stem Cells Enhance Neo-Vascularization during Dermal Regeneration

    PubMed Central

    Rapoport, Daniel H.; Kruse, Charli; Schumann, Sandra; Stang, Felix H.; Siemers, Frank; Matthießen, Anna E.

    2015-01-01

    High numbers of adult stem cells are still required to improve the formation of new vessels in scaffolds to accelerate dermal regeneration. Recent data indicate a benefit for vascularization capacity by stimulating stem cells with lipopolysaccharide (LPS). In this study, stem cells derived from human skin (SDSC) were activated with LPS and seeded in a commercially available dermal substitute to examine vascularization in vivo. Besides, in vitro assays were performed to evaluate angiogenic factor release and tube formation ability. Results showed that LPS-activated SDSC significantly enhanced vascularization of the scaffolds, compared to unstimulated stem cells in vivo. Further, in vitro assays confirmed higher secretion rates of proangiogenic as well as proinflammatoric factors in the presence of LPS-activated SDSC. Our results suggest that combining activated stem cells and a dermal substitute is a promising option to enhance vascularization in scaffold-mediated dermal regeneration. PMID:26565617

  14. The supramolecular structure of LPS-chitosan complexes of varied composition in relation to their biological activity.

    PubMed

    Davydova, V N; Volod'ko, A V; Sokolova, E V; Chusovitin, E A; Balagan, S A; Gorbach, V I; Galkin, N G; Yermak, I M; Solov'eva, T F

    2015-06-01

    The complexes of chitosan (Ch) with lipopolysaccharides (LPSs) from Escherichia coli O55:B5 (E-LPS) and Yersinia pseudotuberculosis 1B 598 (Y-LPS) of various weight compositions were investigated using quasi-elastic light scattering, ζ-potential distribution assay and atomic force microscopy. The alteration of ζ-potential of E-LPS-Ch complexes from negative to positive values depending on Ch content was detected. The Y-LPS-Ch complexes had similar positive ζ-potentials regardless of Ch content. The transformation of the supramolecular structure of E-LPS after binding with to Ch was revealed. Screening of E-LPS and Y-LPS particles by Ch in the complexes with high polycation was detected. The ability of LPS-Ch complex to induce biosynthesis of TNF-α and reactive oxygen species in stimulated human mononuclear cells was studied. A significant decrease in activity complexes compared to that of the initial LPS was observed only for E-LPS-Ch complexes. PMID:25843841

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

    PubMed Central

    Mgcina, Londiwe S.; Dubery, Ian A.; Piater, Lizelle A.

    2015-01-01

    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 labeled LPS were conducted in Arabidopsis thaliana protoplasts and quantified using flow cytometry fluorescence changes. Quantum dots (Qdots), which allow non-covalent, hydrophobic labeling were used as a novel strategy in this study and compared to covalent, hydrophilic labeling 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 labeled 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-labeling strategy in comparison to the conventional Alexa 488 hydrazide label for binding studies. PMID:26029233

  16. The binding capability of plasma phospholipid transfer protein, but not HDL pool size, is critical to repress LPS induced inflammation

    PubMed Central

    Yu, Yang; Cui, Yingjie; Zhao, Yanan; Liu, Shuai; Song, Guohua; Jiao, Peng; Li, Bin; Luo, Tian; Guo, Shoudong; Zhang, Xiangjian; Wang, Hao; Jiang, Xian-Cheng; Qin, Shucun

    2016-01-01

    Phospholipid transfer protein (PLTP) participates in high density lipoprotein (HDL) metabolism. Increased plasma PLTP activity was observed in lipopolysaccharide (LPS) triggered acute inflammatory diseases. This study aimed to determine the exact role of PLTP in LPS induced inflammation. HDL pool size was shrunk both in PLTP deficient mice (PLTP−/−) and PLTP transgenic mice (PLTP-Tg). PLTP displayed a strong protective effect on lethal endotoxemia in mice survival study. Furthermore, after LPS stimulation, the expression of pro-inflammatory cytokines were increased in bone marrow derived macrophage (BMDM) from PLTP−/−, while decreased in BMDM from PLTP-Tg compared with BMDM from wild-type mice (WT). Moreover, LPS induced nuclear factor kappa-B (NFκB) activation was enhanced in PLTP−/− BMDM or PLTP knockdown RAW264.7. Conversely, PLTP overexpression countered the NFκB activation in LPS challenged BMDM. Additionally, the activation of toll like receptor 4 (TLR4) induced by LPS showed no alteration in PLTP−/− BMDM. Finally, PLTP could bind to LPS, attenuate the pro-inflammatory effects of LPS, and improve the cell viability in vitro. To sum up, these findings elucidated that PLTP repressed LPS induced inflammation due to extracellular LPS binding capability, and the protective effects were not related to HDL pool size in mice. PMID:26857615

  17. Ligustrazine effect on lipopolysaccharide-induced pulmonary damage in rats.

    PubMed

    Wang, Huiqi; Chen, Yuanzhuo; Li, Wenjie; Li, Congye; Zhang, Xiangyu; Peng, Hu; Gao, Chengjin

    2015-09-01

    We investigated the effectiveness of ligustrazine (tetramethylpyrazine, TMP) in alleviating pulmonary damage induced by lipopolysaccharide (LPS). Twenty-four healthy male Sprague-Dawley rats were randomly divided into three groups: the blank group, LPS group, and TMP treatment group (TMP group). The LPS group was intraperitoneally injected with LPS (20mg/kg), and the TMP group was intraperitoneally injected with LPS (20mg/kg) and ligustrazine (80mg/kg). Blood gas analysis, hematoxylin-eosin staining dye extravasation and diffuse alveolar damage (DAD) score, the wet/dry lung tissue (W/D) ratios, the expression of CD31+ vascular endothelial microparticles (EMPs), tumor necrosis factor alpha (TNF-α) levels, and the protein expression of Rho-associated coiled-coil-forming protein kinase (ROCK) II and Toll-like receptor 4 (TLR4) were analyzed. Compared with the blank group, the arterial partial pressure of oxygen (PaO2) declined in both 1 and 4h (P<0.01), the W/D ratio and DAD score increased (P<0.01), and the TNF-α levels in serum, CD31+ EMPs, and protein expression of ROCK II and TLR4 were significantly increased (P<0.01) in the LPS group. Compared with the LPS group, PaO2 significantly increased in the TMP group at 4h (P<0.05), while the W/D ratio and DAD score were significantly decreased in the TMP group (P<0.01). TNF-α levels, CD31+ EMPs, and protein expression of ROCK II and TLR4 were significantly decreased in the TMP group compared with the LPS group (P<0.01). This study demonstrated that TMP can alleviate LPS-induced pulmonary damage by attenuating pulmonary vascular permeability and CD31+ EMP levels in the plasma, reducing the release of the inflammatory mediator TNF-α and inhibiting the protein expression of ROCK II and TLR4. PMID:26088147

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

    PubMed Central

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

    1993-01-01

    Lipopolysaccharide (LPS), or endotoxin, is the major mediator of septic shock, a serious complication of Gram-negative bacterial infections in humans. Molecules that bind LPS and neutralize its biological effects or enhance its clearance could have important clinical applications. Limulus anti-LPS factor (LALF) binds LPS tightly, and, in animal models, reduces mortality when administered before or after LPS challenge or bacterial infection. Here we present the high resolution structure of a recombinant LALF. It has a single domain consisting of three alpha-helices packed against a four-stranded beta-sheet. The wedge-shaped molecule has a striking charge distribution and amphipathicity that suggest how it can insert into membranes. The binding site for LPS probably involves an extended amphipathic loop, and we propose that two mammalian LPS-binding proteins will have a similar loop. The amphipathic loop structure may be used in the design of molecules with therapeutic properties against septic shock. Images PMID:8253062

  19. Use of mice tolerant to lipopolysaccharide to demonstrate requirement of cooperation between macrophages and lymphocytes to generate lipopolysaccharide-induced colony-stimulating factor in vivo.

    PubMed Central

    Williams, Z; Hertogs, C F; Pluznik, D H

    1983-01-01

    Injection of lipopolysaccharide (LPS) into mice was followed by a rapid elevation of colony-stimulating factor (CSF) in the serum. A second, challenging injection of LPS given 3 to 4 days later failed to induce elevated levels of CSF in the serum. Such mice tolerant to LPS were used as an experimental tool to identify the CSF-producing cells which respond to LPS. We observed that generation of LPS-induced CSF in mice tolerant to LPS could be restored by an intraperitoneal injection of spleen cells 24 h before the challenging injection of LPS. Depletion of the adherent cells from the spleen cells reduced the ability of the splenic lymphocytes to restore the capacity of the mice tolerant to LPS to generate serum CSF. Reconstitution of the splenic lymphocytes with 5% thioglycolate-elicited peritoneal macrophages, however, reestablished the restorative capacity of these cells, whereas almost no restoration was observed after direct injection of elicited peritoneal macrophages. These data suggest that the spleen cells are active in generating CSF, provided that macrophages are present and can interact with the splenic lymphocytes to generate LPS-induced CSF in the serum. PMID:6602767

  20. Interaction between tachyplesin I, an antimicrobial peptide derived from horseshoe crab, and lipopolysaccharide.

    PubMed

    Kushibiki, Takahiro; Kamiya, Masakatsu; Aizawa, Tomoyasu; Kumaki, Yasuhiro; Kikukawa, Takashi; Mizuguchi, Mineyuki; Demura, Makoto; Kawabata, Shun-ichiro; Kawano, Keiichi

    2014-03-01

    Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and is the very first site of interactions with antimicrobial peptides (AMPs). In order to gain better insight into the interaction between LPS and AMPs, we determined the structure of tachyplesin I (TP I), an antimicrobial peptide derived from horseshoe crab, in its bound state with LPS and proposed the complex structure of TP I and LPS using a docking program. CD and NMR measurements revealed that binding to LPS slightly extends the two β-strands of TP I and stabilizes the whole structure of TP I. The fluorescence wavelength of an intrinsic tryptophan of TP I and fluorescence quenching in the presence or absence of LPS indicated that a tryptophan residue is incorporated into the hydrophobic environment of LPS. Finally, we succeeded in proposing a structural model for the complex of TP I and LPS by using a docking program. The calculated model structure suggested that the cationic residues of TP I interact with phosphate groups and saccharides of LPS, whereas hydrophobic residues interact with the acyl chains of LPS. PMID:24389234

  1. Peptide-assembled graphene oxide as a fluorescent turn-on sensor for lipopolysaccharide (endotoxin) detection.

    PubMed

    Lim, Seng Koon; Chen, Peng; Lee, Fook Loy; Moochhala, Shabbir; Liedberg, Bo

    2015-09-15

    Lipopolysaccharide (LPS) is a toxic inflammatory stimulator released from the outer cell membrane of Gram-negative bacteria, known to be directly related to, for example, septic shock, that causes millions of casualties annually. This number could potentially be lowered significantly if specific, sensitive, and more simply applicable LPS biosensors existed. In this work, we present a facile, sensitive and selective LPS sensor, developed by assembling tetramethylrhodamine-labeled LPS-binding peptides on graphene oxide (GO). The fluorescence of the dye-labeled peptide is quenched upon interaction with GO. Specific binding to LPS triggers the release of the peptide-LPS complex from GO, resulting in fluorescence recovery. This fluorescent turn-on sensor offers an estimated limit of detection of 130 pM, which is the lowest ever reported among all synthetic LPS sensors to date. Importantly, this sensor is applicable for detection of LPS in commonly used clinical injectable fluids, and it enables selective detection of LPS from different bacterial strains as well as LPS on the membrane of living E. coli. PMID:26303386

  2. Porphyromonas gingivalis Lipopolysaccharide Induced Proliferation and Activation of Natural Killer Cells in Vivo.

    PubMed

    Wang, Yuhua; Zhang, Wei; Xu, Li; Jin, Jun-O

    2016-01-01

    Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) promoted different innate immune activation than that promoted by Escherichia coli (E. coli) LPS. In this study, we examined the effect of P. gingivalis LPS on the proliferation and activation of natural killer (NK) cells in vivo and compared that function with that of E. coli LPS. Administration of P. gingivalis LPS to C57BL/6 mice induced stronger proliferation of NK cells in the spleen and submandibular lymph nodes (sLNs) and increased the number of circulating NK cells in blood compared to those treated with E. coli LPS. However, P. gingivalis LPS did not induce interferon-gamma (IFN-γ) production and CD69 expression in the spleen and sLN NK cells in vivo, and this was attributed to the minimal activation of the spleen and sLN dendritic cells (DCs), including low levels of co-stimulatory molecule expression and pro-inflammatory cytokine production. Furthermore, P. gingivalis LPS-treated NK cells showed less cytotoxic activity against Yac-1 target cells than E. coli LPS-treated NK cells. Hence, these data demonstrated that P. gingivalis LPS promoted limited activation of spleen and sLN NK cells in vivo, and this may play a role in the chronic inflammatory state observed in periodontal disease. PMID:27548133

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

    PubMed

    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. PMID:26530889

  4. Lipopolysaccharide, central in vivo biogenic amine variations, and anhedonia.

    PubMed

    Borowski, T; Kokkinidis, L; Merali, Z; Anisman, H

    1998-12-01

    Systemic administration of lipopolysaccharide (LPS), a non-specific activator of proinflammatory cytokine release from macrophages, provokes sickness characterized by anorexia, soporific effects, and disturbances of locomotor activity and exploration. In addition, endotoxin treatment may provoke an anhedonic response. Assessment of anhedonia in appetitive paradigms, however, is compromised by the anorexia provoked by the treatment. The present investigation assessed the anhedonic effects of LPS on rewarding lateral hypothalamic brain stimulation. Using a simultaneous discrimination, current titration procedure in the assessment of intracranial self-stimulation (ICSS), it was found that acute systemic administration of LPS (50 microg, 100 microg or 200 microg) reduced ICSS during the ascending sequence of current presentations, but had little effect on responding to a series of descending currents. In a parallel experiment, peripheral administration of LPS (100 microg) increased in vivo dopamine (DA) efflux from the nucleus accumbens, a region thought to be involved in goal-directed responding to positively reinforcing stimuli. It is suggested that LPS alters ICSS in a manner different than that observed following stressor exposure or peripheral IL-2 treatment. Furthermore, LPS may engender an anhedonic effect (possibly secondary to sickness), and the decline of responding reflects the relation between the cost of responding given in the face of sickness and the reward received for responding. PMID:9875707

  5. Lipopolysaccharide Attenuates the Cytotoxicity of Resveratrol in Transformed Mouse Macrophages.

    PubMed

    Achy-Brou, Christelle A Adiabouah; Billack, Blase

    2016-09-01

    Resveratrol and pterostilbene are natural products that are present in plants and have been incorporated into various dietary supplements. Numerous beneficial pharmacologic effects have been reported for these stilbenes; however, the mechanism by which these compounds exert a cytotoxic effect in RAW 264.7 macrophages has not been well characterized. We have previously described that resveratrol is toxic to these tumor-derived macrophages and that stimulation with lipopolysaccharide (LPS) reduces resveratrol toxicity via a mechanism that involves activation of toll like receptor 4. In the present work, we examined the cellular and molecular effects of resveratrol and the related compound pterostilbene by determining cell viability and caspase 3 activity in control and LPS-stimulated RAW 264.7 macrophages incubated with these stilbenes for 24 h. We found that LPS stimulation reduced the cytotoxicity of resveratrol but not of pterostilbene in these cells. When examined for effects on caspase 3 activation after a 24 h incubation, resveratrol and pterostilbene were each found to separately and significantly increase caspase 3 activity in these cells. LPS stimulation prevented caspase 3 activation by pterostilbene and reduced caspase 3 activation by resveratrol in RAW 264.7 macrophages. The data presented here indicate that LPS induces a phenotype switch in tumor-derived RAW 264.7 macrophages in which cells experiencing LPS in the presence of resveratrol or pterostilbene become less likely to activate the pro-apoptotic factor caspase 3. PMID:27277074

  6. A method for generating pulmonary neutrophilia using aerosolized lipopolysaccharide.

    PubMed

    Roos, Abraham B; Berg, Tove; Ahlgren, Kerstin M; Grunewald, Johan; Nord, Magnus

    2014-01-01

    Acute lung injury (ALI) is a severe disease characterized by alveolar neutrophilia, with limited treatment options and high mortality. Experimental models of ALI are key in enhancing our understanding of disease pathogenesis. Lipopolysaccharide (LPS) derived from gram positive bacteria induces neutrophilic inflammation in the airways and lung parenchyma of mice. Efficient pulmonary delivery of compounds such as LPS is, however, difficult to achieve. In the approach described here, pulmonary delivery in mice is achieved by challenge to aerosolized Pseudomonas aeruginosa LPS. Dissolved LPS was aerosolized by a nebulizer connected to compressed air. Mice were exposed to a continuous flow of LPS aerosol in a Plexiglas box for 10 min, followed by 2 min conditioning after the aerosol was discontinued. Tracheal intubation and subsequent bronchoalveolar lavage, followed by formalin perfusion was next performed, which allows for characterization of the sterile pulmonary inflammation. Aerosolized LPS generates a pulmonary inflammation characterized by alveolar neutrophilia, detected in bronchoalveolar lavage and by histological assessment. This technique can be set up at a small cost with few appliances, and requires minimal training and expertise. The exposure system can thus be routinely performed at any laboratory, with the potential to enhance our understanding of lung pathology. PMID:25548888

  7. Membrane insertion for the detection of lipopolysaccharides: Exploring the dynamics of amphiphile-in-lipid assays

    DOE PAGESBeta

    Stromberg, Loreen R.; Hengartner, Nicolas W.; Swingle, Kirstie L.; Moxley, Rodney A.; Graves, Steven W.; Montano, Gabriel A.; Mukundan, Harshini; Gasset, Maria

    2016-05-26

    Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assaysmore » to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. In addition, we also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection

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

    PubMed

    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. PMID:23751331

  9. Cross-reactive polyclonal antibodies to the inner core of lipopolysaccharide from Neisseria meningitidis.

    PubMed

    Andersen, Svein Rune; Guthrie, Terry; Guile, Geoffrey R; Kolberg, Jan; Hou, Sam; Hyland, Lisa; Wong, Simon Y C

    2002-03-01

    Sera from mice immunized with native or detergent-extracted outer membrane vesicles derived from lipopolysaccharide (LPS) mutant 44/76(Mu-4) of Neisseria meningitidis were analyzed for antibodies to LPS. The carbohydrate portion of 44/76(Mu-4) LPS consists of the complete inner core, Glc beta 1-->4[GlcNAc alpha 1-->2Hep alpha 1-->3]Hep alpha 1-->5KDO[4-->2 alpha KDO]. Immunoblot analysis revealed that some sera contained antibodies to wild-type LPS which has a fully extended carbohydrate chain of immunotype L3,7, as well as to the homologous LPS. Sera reacted only weakly to LPS from 44/76(Mu-3), which lacks the terminal glucose of the inner core. No binding to more truncated LPS was observed. Consequently, the cross-reactive epitopes are expressed mainly by the complete inner core. Dephosphorylation of wild-type LPS abolished antibody binding to LPS in all but one serum. Thus, at least two specificities of cross-reactive antibodies exist: one is dependent on phosphoethanolamine groups in LPS, and one is not. Detection of these cross-reactive antibodies strongly supports the notion that epitopes expressed by meningococcal LPS inner core are also accessible to antibodies when the carbohydrate chain is fully extended. Also, these inner core epitopes are sufficiently immunogenic to induce antibody levels detectable in polyclonal antibody responses. Meningococci can escape being killed by antibodies to LPS that bind only to a specific LPS variant, by altering the carbohydrate chain length. Cross-reactive antibodies may prevent such escape. Therefore, inner core LPS structures may be important antigens in future vaccines against meningococcal disease. PMID:11854213

  10. Nitric oxide production by murine spleen cells stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans.

    PubMed

    Sosroseno, Wihaskoro; Herminajeng, Endang; Susilowati, Heni; Budiarti, Sri

    2002-12-01

    The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could induce murine spleen cells to produce nitric oxide (NO). Spleen cells derived from Balb/c mice were stimulated with LPS-A. actinomycetemcomitans or LPS from Escherichia coli for 4 days. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B, and cytokines (IFN-gamma and IL-4) on the production of NO were also assessed. The NO production from the carrageenan-treated spleen cells stimulated with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma was determined. The carrageenan-treated mice were transferred with splenic macrophages and the NO production was assessed from the spleen cells stimulated with LPS-A. actinomycetemcomitans or LPS-A. actinomycetemcomitans and IFN-gamma. The results showed that NO production was detectable in the cultures of spleen cells stimulated with LPS-A. actinomycetemcomitans in a dose-dependent fashion, but was lower than in the cells stimulated with LPS from E. coli. The NO production was blocked by NMMA and polymyxin B. IFN-gamma up-regulated but IL-4 suppressed the production of NO by the spleen cells stimulated with LPS-A. actinomycetemcomitans. The carrageenan-treated spleen cells failed to produce NO after stimulation with LPS-A. actinomycetemcomitans or both LPS-A. actinomycetemcomitans and IFN-gamma. Adoptive transfer of splenic macrophages to the carrageenan-treated mice could restore the ability of the spleen cells to produce NO. The results of the present study suggest that LPS-A. actinomycetemcomitans under the regulatory control of cytokines induces murine spleen cells to produce NO and that splenic macrophages are the cellular source of the NO production. Therefore, these results may support the view that NO production by LPS-A. actinomycetemcomitans-stimulated macrophages may play a role in the course of periodontal diseases. PMID:16887678

  11. Membrane Insertion for the Detection of Lipopolysaccharides: Exploring the Dynamics of Amphiphile-in-Lipid Assays

    PubMed Central

    Hengartner, Nicolas W.; Swingle, Kirstie L.; Moxley, Rodney A.; Graves, Steven W.

    2016-01-01

    Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assays to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. We also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures. PMID

  12. Adsorption of Toll-Like Receptor 4 Agonist to Alum-Based Tetanus Toxoid Vaccine Dampens Pro-T Helper 2 Activities and Enhances Antibody Responses.

    PubMed

    Bortolatto, Juliana; Mirotti, Luciana; Rodriguez, Dunia; Gomes, Eliane; Russo, Momtchilo

    2015-01-01

    Aluminum salts gels (alum) are TLR-independent adjuvants and have been used to boost antibody responses in alum-based vaccines such as diphtheria, pertussis, and tetanus toxoid (DPT) triple vaccine. However, the pro-Th2 activity of alum-based vaccine formulations has not been fully appreciated. Here we found that alum-based tetanus toxoid (TT) vaccine was biased toward a Th-2 profile as shown by TT-induced airway eosinophilic inflammation, type 2 cytokine production, and high levels of IgE anaphylactic antibodies. The adsorption into alum of prototypic TLR4 agonists such as lipopolysaccharides (LPS) derived from Escherichia coli consistently dampened TT-induced Th2 activities without inducing IFNγ or Th1-like responses in the lung. Conversely, adsorption of monophosphoryl lipid A (MPLA) extracted from Salmonella minnesota, which is a TIR-domain-containing adapter-inducing interferon-β- (TRIF-) biased TLR4 agonist, was less effective in decreasing Th-2 responses. Importantly, in a situation with antigenic competition (OVA plus TT), TT-specific IgG1 or IgG2a was decreased compared with TT sensitization. Notably, LPS increased the production of IgG1 and IgG2a TT-specific antibodies. In conclusion, the addition of LPS induces a more robust IgG1 and IgG2a TT-specific antibody production and concomitantly decreases Th2-cellular and humoral responses, indicating a potential use of alum/TLR-based vaccines. PMID:26380316

  13. Adsorption of Toll-Like Receptor 4 Agonist to Alum-Based Tetanus Toxoid Vaccine Dampens Pro-T Helper 2 Activities and Enhances Antibody Responses

    PubMed Central

    Bortolatto, Juliana; Mirotti, Luciana; Rodriguez, Dunia; Gomes, Eliane; Russo, Momtchilo

    2015-01-01

    Aluminum salts gels (alum) are TLR-independent adjuvants and have been used to boost antibody responses in alum-based vaccines such as diphtheria, pertussis, and tetanus toxoid (DPT) triple vaccine. However, the pro-Th2 activity of alum-based vaccine formulations has not been fully appreciated. Here we found that alum-based tetanus toxoid (TT) vaccine was biased toward a Th-2 profile as shown by TT-induced airway eosinophilic inflammation, type 2 cytokine production, and high levels of IgE anaphylactic antibodies. The adsorption into alum of prototypic TLR4 agonists such as lipopolysaccharides (LPS) derived from Escherichia coli consistently dampened TT-induced Th2 activities without inducing IFNγ or Th1-like responses in the lung. Conversely, adsorption of monophosphoryl lipid A (MPLA) extracted from Salmonella minnesota, which is a TIR-domain-containing adapter-inducing interferon-β- (TRIF-) biased TLR4 agonist, was less effective in decreasing Th-2 responses. Importantly, in a situation with antigenic competition (OVA plus TT), TT-specific IgG1 or IgG2a was decreased compared with TT sensitization. Notably, LPS increased the production of IgG1 and IgG2a TT-specific antibodies. In conclusion, the addition of LPS induces a more robust IgG1 and IgG2a TT-specific antibody production and concomitantly decreases Th2-cellular and humoral responses, indicating a potential use of alum/TLR-based vaccines. PMID:26380316

  14. Lipopolysaccharide modification in Gram-negative bacteria during chronic infection.

    PubMed

    Maldonado, Rita F; Sá-Correia, Isabel; Valvano, Miguel A

    2016-07-01

    The Gram-negative bacterial lipopolysaccharide (LPS) is a major component of the outer membrane that plays a key role in host-pathogen interactions with the innate immune system. During infection, bacteria are exposed to a host environment that is typically dominated by inflammatory cells and soluble factors, including antibiotics, which provide cues about regulation of gene expression. Bacterial adaptive changes including modulation of LPS synthesis and structure are a conserved theme in infections, irrespective of the type or bacteria or the site of infection. In general, these changes result in immune system evasion, persisting inflammation and increased antimicrobial resistance. Here, we review the modifications of LPS structure and biosynthetic pathways that occur upon adaptation of model opportunistic pathogens (Pseudomonas aeruginosa, Burkholderia cepacia complex bacteria, Helicobacter pylori and Salmonella enterica) to chronic infection in respiratory and gastrointestinal sites. We also discuss the molecular mechanisms of these variations and their role in the host-pathogen interaction. PMID:27075488

  15. Molecular Mechanisms Regulating LPS-Induced Inflammation in the Brain

    PubMed Central

    Lykhmus, Olena; Mishra, Nibha; Koval, Lyudmyla; Kalashnyk, Olena; Gergalova, Galyna; Uspenska, Kateryna; Komisarenko, Serghiy; Soreq, Hermona; Skok, Maryna

    2016-01-01

    Neuro-inflammation, one of the pathogenic causes of neurodegenerative diseases, is regulated through the cholinergic anti-inflammatory pathway via the α7 nicotinic acetylcholine receptor (α7 nAChR). We previously showed that either bacterial lipopolysaccharide (LPS) or immunization with the α7(1–208) nAChR fragment decrease α7 nAChRs density in the mouse brain, exacerbating chronic inflammation, beta-amyloid accumulation and episodic memory decline, which mimic the early stages of Alzheimer’s disease (AD). To study the molecular mechanisms underlying the LPS and antibody effects in the brain, we employed an in vivo model of acute LPS-induced inflammation and an in vitro model of cultured glioblastoma U373 cells. Here, we report that LPS challenge decreased the levels of α7 nAChR RNA and protein and of acetylcholinesterase (AChE) RNA and activity in distinct mouse brain regions, sensitized brain mitochondria to the apoptogenic effect of Ca2+ and modified brain microRNA profiles, including the cholinergic-regulatory CholinomiRs-132/212, in favor of anti-inflammatory and pro-apoptotic ones. Adding α7(1–208)-specific antibodies to the LPS challenge prevented elevation of both the anti-inflammatory and pro-apoptotic miRNAs while supporting the resistance of brain mitochondria to Ca2+ and maintaining α7 nAChR/AChE decreases. In U373 cells, α7-specific antibodies and LPS both stimulated interleukin-6 production through the p38/Src-dependent pathway. Our findings demonstrate that acute LPS-induced inflammation induces the cholinergic anti-inflammatory pathway in the brain, that α7 nAChR down-regulation limits this pathway, and that α7-specific antibodies aggravate neuroinflammation by inducing the pro-inflammatory interleukin-6 and dampening anti-inflammatory miRNAs; however, these antibodies may protect brain mitochondria and decrease the levels of pro-apoptotic miRNAs, preventing LPS-induced neurodegeneration. PMID:27013966

  16. Rhizobium meliloti chromosomal loci required for suppression of exopolysaccharide mutations by lipopolysaccharide

    SciTech Connect

    Williams, M.N.V.; Brzoska, P.M.; Signer, E.R. ); Hollingsworth, R.I. )

    1990-11-01

    Mutants of alfalfa symbiont Rhizobium meliloti SU47 that fail to make extracellular polysaccharide (exo mutants) induce the formation of nodules that are devoid of bacteria and consequently do not fix nitrogen. This Fix{sup {minus}} phenotype can be suppressed by an R. meliloti Rm41 gene that affects lipopolysaccharide structure. Here we describe mutations preventing suppression that map at two new chromosomal loci, lpsY and lpsX, present in both strains. Two other lps mutations isolated previously from SU47 also prevented suppression.

  17. Changes in endothelial cell proliferation and vascular permeability after systemic lipopolysaccharide administration in the subfornical organ.

    PubMed

    Morita-Takemura, Shoko; Nakahara, Kazuki; Tatsumi, Kouko; Okuda, Hiroaki; Tanaka, Tatsuhide; Isonishi, Ayami; Wanaka, Akio

    2016-09-15

    The subfornical organ (SFO) has highly permeable fenestrated vasculature and is a key site for immune-to-brain communications. Recently, we showed the occurrence of continuous angiogenesis in the SFO. In the present study, we found that systemic administration of bacterial lipopolysaccharide (LPS) reduced the vascular permeability and endothelial cell proliferation. In LPS-administered mice, the SFO vasculature showed a significant decrease in the immunoreactivity of plasmalemma vesicle associated protein-1, a marker of endothelial fenestral diaphragms. These data suggest that vasculature undergoes structural change to decrease vascular permeability in response to systemic LPS administration. PMID:27609286

  18. Exogenous heat shock protein HSP70 reduces response of human neuroblastoma cells to lipopolysaccharide.

    PubMed

    Yurinskaya, M M; Funikov, S Y; Evgen'ev, M B; Vinokurov, M G

    2016-07-01

    The effect of exogenous heat shock protein HSP70 and lipopolysaccharide (LPS) on the production of reactive oxygen species (ROS), TNFα secretion, and mRNA expression by human neuroblastoma SK-N-SH cells. It was shown that exogenous HSP70 protects neuroblastoma cells from the action of LPS. The protection mechanism of HSP70 includes a reduction in the production of ROS and TNFα and a decrease in the expression of TLR4 and IL-1β mRNA in SK-N-SH cells induced by LPS. PMID:27599502

  19. Attenuation of lipopolysaccharide-induced oxidative stress and apoptosis in fetal pulmonary artery endothelial cells by hypoxia.

    PubMed

    Sampath, Venkatesh; Radish, Aaron C; Eis, Annie L; Broniowska, Katarzyna; Hogg, Neil; Konduri, Girija G

    2009-03-01

    Pulmonary vascular endothelial injury resulting from lipopolysaccharide (LPS) and oxygen toxicity contributes to vascular simplification seen in the lungs of premature infants with bronchopulmonary dysplasia. Whether the severity of endotoxin-induced endothelial injury is modulated by ambient oxygen tension (hypoxic intrauterine environment vs. hyperoxic postnatal environment) remains unknown. We posited that ovine fetal pulmonary artery endothelial cells (FPAEC) will be more resistant to LPS toxicity under hypoxic conditions (20-25 Torr) mimicking the fetal milieu. LPS (10 microg/ml) inhibited FPAEC proliferation and induced apoptosis under normoxic conditions (21% O(2)) in vitro. LPS-induced FPAEC apoptosis was attenuated in hypoxia (5% O(2)) and exacerbated by hyperoxia (55% O(2)). LPS increased intracellular superoxide formation, as measured by 2-hydroxyethidium (2-HE) formation, in FPAEC in normoxia and hypoxia. 2-HE formation in LPS-treated FPAEC increased in parallel with the severity of LPS-induced apoptosis in FPAEC, increasing from hypoxia to normoxia to hyperoxia. Differences in LPS-induced apoptosis between hypoxia and normoxia were abolished when LPS-treated FPAEC incubated in hypoxia were pretreated with menadione to increase superoxide production. Apocynin decreased 2-HE formation, and attenuated LPS-induced FPAEC apoptosis under normoxic conditions. We conclude that ambient oxygen concentration modulates the severity of LPS-mediated injury in FPAEC by regulating superoxide levels produced in response to LPS. PMID:19135525

  20. A broadband capacitive sensing method for label-free bacterial LPS detection.

    PubMed

    Rydosz, Artur; Brzozowska, Ewa; Górska, Sabina; Wincza, Krzysztof; Gamian, Andrzej; Gruszczynski, Slawomir

    2016-01-15

    In this paper, the authors present a new type of highly sensitive label-free microwave sensor in a form of interdigital capacitor coated with T4 bacteriophage gp37 adhesin. The adhesin binds Escherichia coli B (E. coli B) by precise recognizing its bacterial host lipopolysaccharide (LPS). The C-terminal part of the adhesin consists of the receptor-binding amino acid residues which are involved in a specific interaction with two terminal glucose residues of the bacterial LPS. The change of the sensors' capacitance and conductance as a subject to LPS presence is an indicator of the detection. The measurements in the frequency range of 0-3GHz utilizing vector network analyzer have been carried out at different concentrations to verify experimentally the proposed method. The measured capacitance change between the reference and the biofunctionalized sensor equals 15% in the entire frequency range and the measured conductance change exceeds 19%. The changes of both parameters can be used as good indicators of the LPS detection. The selectivity has been confirmed by the ELISA experiments and tested by sensor measurements with lipopolysaccharide (LPS) from E. coli B, E. coli 056, E. coli 0111, Pseudomonas aeruginosa NBRC 13743 and Hafnia alvei 1185. PMID:26339930

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

    PubMed Central

    López-Abarrategui, Carlos; del Monte-Martínez, Alberto; Reyes-Acosta, Osvaldo; Franco, Octavio L.; Otero-González, Anselmo J.

    2013-01-01

    Lipopolysaccharides (LPSs) are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no Food and Drug Administration-approved drug yet that interacts directly against LPS. Cationic host-defense peptides (HDPs) could be an alternative solution since they possess both antimicrobial and antiseptic properties. HDPs are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating HDPs that recognize LPS. This approach could expand the rational search for anti-LPS HDPs. PMID:24409171

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

    PubMed

    López-Abarrategui, Carlos; Del Monte-Martínez, Alberto; Reyes-Acosta, Osvaldo; Franco, Octavio L; Otero-González, Anselmo J

    2013-01-01

    Lipopolysaccharides (LPSs) are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no Food and Drug Administration-approved drug yet that interacts directly against LPS. Cationic host-defense peptides (HDPs) could be an alternative solution since they possess both antimicrobial and antiseptic properties. HDPs are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating HDPs that recognize LPS. This approach could expand the rational search for anti-LPS HDPs. PMID:24409171

  3. Astragalus polysaccharide reduces inflammatory response by decreasing permeability of LPS-infected Caco2 cells.

    PubMed

    Wang, Xiaofei; Li, Yulong; Yang, Xiaojun; Yao, Junhu

    2013-10-01

    As the major constituent of Radix Astragali, Astragalus polysaccharide (APS) is known for its anti-inflammation and immunomodulatory functions. The objective of this study was to investigate the effect of APS on inflammatory response and structural changes in lipopolysaccharide (LPS)-infected Caco2 cells. Caco2 cells were co-cultured with APS and LPS, with APS added after the addition of LPS (post-addition), before the addition of LPS (pre-addition), or simultaneously with the addition of LPS (simultaneous addition). The mRNA expression of inflammatory indicators and tight junctions was measured by RT-qPCR. Short circuit current (Isc) was recorded by an Ussing chamber system. Addition of APS significantly down-regulated the expression of TNF-α, IL-1β and IL-8 (P<0.05) and the Isc levels (P<0.05) of LPS-infected Caco2 cells for all three administration treatments. The minimum anti-inflammatory concentration of APS was 50, 100, and 100 μg/mL for pre-, post-, and simultaneous additions of APS, respectively. The mRNA expression of zonula occludens-1 (ZO-1) and occludin was significantly up-regulated for post- and pre-additions of APS, respectively (P<0.05). Results suggested that APS had anti-inflammatory and structure protective properties for LPS-infected Caco2 cells, and may be used as a preventative treatment for intestine cells. PMID:23916649

  4. Lung mechanics are both dose and tidal volume dependant in LPS-induced lung injury.

    PubMed

    Dixon, Dani-Louise; De Smet, Hilde R; Bersten, Andrew D

    2009-07-31

    Endotoxin stimulus plays a significant role in various forms of acute lung injury (ALI) which may be exacerbated by mechanical ventilation. Here, we identify the temporal pathophysiologic sequence following inhaled lipopolysaccharide (LPS) and subsequently examine both LPS dose and V(T) relationships. Rats received intratracheal LPS (3, 9 or 15 mg/kg) prior to mechanical ventilation (V(T)=6, 9 or 12 ml/kg) and measurement of forced impedance mechanics for up to 4h. LPS-induced lung injury was achieved within the 15 min of LPS instillation with a 78% decrease in PaO(2) promptly followed by approximately 30% deterioration in tissue elastance. Despite a 41% increase in total surfactant, the active disaturated phospholipid fraction decreased 3-7% with decreasing PaO(2) and tissue mechanics and with increases in total lung lavage protein (150%) and wet-to-dry lung weight ratio (10%). V(T)=12 ml/kg resulted in an additional deterioration in tissue resistance (130%) and elastance (63%). These results suggest that LPS-induced lung injury is both LPS dose and V(T) sensitive, supporting a 'two hit' model of ALI. PMID:19539791

  5. TSPO ligand PK11195 alleviates neuroinflammation and beta-amyloid generation induced by systemic LPS administration.

    PubMed

    Ma, Li; Zhang, Hui; Liu, Na; Wang, Pei-qi; Guo, Wen-zhi; Fu, Qiang; Jiao, Lin-bo; Ma, Ya-qun; Mi, Wei-Dong

    2016-03-01

    Translocator protein 18 kDa (TSPO) is now an attractive drug target for controlling neuroinflammation. Studies applying TSPO ligands to neurodegenerative diseases, especially Alzheimer's disease (AD), were rare. Our study was aimed to evaluate the effect of PK11195, a specific TSPO ligand, in an animal model of neuroinflammation caused by systemic LPS administration. C57/BL6 mice were treated with lipopolysaccharide (LPS, 500 μg/kg, i.p.) three days after PK11195 administration (3mg/kg, i.p.). The drugs were not discontinued until the mice were sacrificed. Cognitive function was assessed by Morris water maze (MWM) seven days after LPS injection. Chronic LPS-injection in mice was characterized by cognitive dysfunction, increased expression of cyclooxygenase (COX)-2 and TSPO, elevated Aβ content with increased expression of β-site APP cleaving enzyme-1 (BACE-1) and insulin-degrading enzyme (IDE) as well as decreased brain progesterone and brain-derived neurophic factor (BDNF) level. PK11195 pretreatment protected cognitive function in LPS-injected animals and normalized the inflammatory proteins. Moreover, PK11195 pre-administration decreased elevated hippocampal Aβx-42 levels and increased brain levels of progesterone, allopregnanolone. However, LPS-induced BDNF decrease was not reversed by PK11195 administration. Our data demonstrated that PK11195 could protect cognitive deficits induced by chronic LPS administration. The underling mechanism may involve alleviated neuroinflammation, increased synthesis of neurosteroid and decreased Aβ accumulation accompanied by down-regulation of BACE-1. PMID:26851069

  6. Effects of matrix metalloproteinase inhibitor on LPS-induced goblet cell metaplasia.

    PubMed

    Kim, Je Hyeong; Lee, Sung Yong; Bak, Sang Myeon; Suh, In Bum; Lee, Sang Yeub; Shin, Chol; Shim, Jae Jeong; In, Kwang Ho; Kang, Kyung Ho; Yoo, Se Hwa

    2004-07-01

    Bacterial infections of the lung are known to induce inflammatory responses, which lead to mucus hypersecretion. Moreover, mucin synthesis in the airways has been reported to be regulated by neutrophilic inflammation-induced epidermal growth factor receptor (EGFR) expression and its activation. Furthermore, matrix metalloproteinases (MMPs), especially MMP-9, have been reported to promote the transmigration of activated neutrophils. In this study, we investigated the associations between lipopolysaccharide (LPS)-induced goblet cell (GC) metaplasia and EGFR expression and the effects of MMP inhibitor (MMPI). Various concentrations of LPS were instilled into the tracheas of pathogen-free Sprague-Dawley rats, and airways were examined at different times after LPS instillation. To examine the role of MMP-9, we treated rats 3 days before LPS instillation and daily thereafter with MMPI. Neutrophilic infiltration, Alcian blue/periodic acid-Schiff (AB/PAS) staining, and immunohistochemical staining for MUC5AC, EGFR, and MMP-9 were performed. The instillation of LPS increased AB/PAS and MUC5AC staining in time- and dose-dependent manners, and treatment with MMPI significantly prevented GC metaplasia. The instillation of LPS into the trachea also induced neutrophilic infiltration and EGFR and MMP-9 expression in the airway epithelium, and MMPI was found to significantly prevent neutrophil recruitment, GC metaplasia, and EGFR and MMP-9 expression. This study demonstrates that the MMP-9 and EGFR cascades are associated with LPS-induced mucus hypersecretion. PMID:15020297

  7. Granzyme K synergistically potentiates LPS-induced cytokine responses in human monocytes.

    PubMed

    Wensink, Annette C; Kemp, Vera; Fermie, Job; García Laorden, M Isabel; van der Poll, Tom; Hack, C Erik; Bovenschen, Niels

    2014-04-22

    Granzymes are serine proteases released by cytotoxic lymphocytes to induce apoptosis in virus-infected cells and tumor cells. Evidence is emerging that granzymes also play a role in controlling inflammation. Granzyme serum levels are elevated in patients with autoimmune diseases and infections, including sepsis. However, the function of extracellular granzymes in inflammation largely remains unknown. Here, we show that granzyme K (GrK) binds to Gram-negative bacteria and their cell-wall component lipopolysaccharide (LPS). GrK synergistically enhances LPS-induced cytokine release in vitro from primary human monocytes and in vivo in a mouse model of LPS challenge. Intriguingly, these extracellular effects are independent of GrK catalytic activity. GrK disaggregates LPS from micelles and augments LPS-CD14 complex formation, thereby likely boosting monocyte activation by LPS. We conclude that extracellular GrK is an unexpected direct modulator of LPS-TLR4 signaling during the antimicrobial innate immune response. PMID:24711407

  8. Transiently enhanced LPS-induced fever following hyperthermic stress in rabbits

    NASA Astrophysics Data System (ADS)

    Shibata, Masaaki; Uno, Tadashi; Riedel, Walter; Nishimaki, Michiyo; Watanabe, Kaori

    2005-11-01

    Hyperthermia has been shown to induce an enhanced febrile response to the bacterial-derived endotoxin lipopolysaccharide (LPS). The aim of the present study was to test the hypothesis that the enhanced LPS-induced fever seen in heat stressed (HS) animals is caused by leakage of intestinal bacterial LPS into the circulation. Male rabbits were rendered transiently hyperthermic (a maximum rectal temperature of 43°C) and divided into three groups. They were then allowed to recover in a room at 24°C for 1, 2 or 3 days post-HS. One day after injection with LPS, the post-HS rabbits exhibited significantly higher fevers than the controls, though this was not seen in rabbits at either 2 or 3 days post-HS. The plasma levels of endogenous LPS were significantly increased during the HS as compared to those seen in normothermic rabbits prior to HS. LPS fevers were not induced in these animals. One day post-HS, rabbits that had been pretreated with oral antibiotics exhibited significantly attenuated LPS levels. When challenged with human recombinant interleukin-1β instead of LPS, the 1-day post-HS rabbits did not respond with enhanced fevers. The plasma levels of TNFα increased similarly during LPS-induced fevers in both the control and 1-day post-HS rabbits, while the plasma levels of corticosterone and the osmolality of the 1-day post-HS rabbits showed no significant differences to those seen prior to the HS. These results suggest that the enhanced fever in the 1-day post-HS rabbits is LPS specific, and may be caused by increased leakage of intestinal endotoxin into blood circulation.

  9. 4-Hydroxydocosahexaenoic acid, a potent peroxisome proliferator-activated receptor {gamma} agonist alleviates the symptoms of DSS-induced colitis

    SciTech Connect

    Yamamoto, Keiko; Ninomiya, Yuichi; Iseki, Mioko; Nakachi, Yutaka; Kanesaki-Yatsuka, Yukiko; Yamanoue, Yu; Itoh, Toshimasa; Nishii, Yasuho; Petrovsky, Nikolai; Okazaki, Yasushi

    2008-03-14

    (5E,7Z,10Z,13Z,16Z,19Z)-4-Hydroxy-5,7,10,13,16,19-docosahexaenoic acid (4-OHDHA) is a potential agonist of peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) and antidiabetic agent as has been previously reported. As PPAR{gamma} agonists may also have anti-inflammatory functions, in this study, we investigated whether 4-OHDHA has an inhibitory effect on expression of inflammatory genes in vitro and whether 4-OHDHA could relieve the symptoms of dextran sodium sulfate (DSS)-induced colitis in a murine model of inflammatory bowel disease. 4-OHDHA inhibited production of nitric oxide and expression of a subset of inflammatory genes including inducible nitric oxide synthase (Nos2/iNOS) and interleukin 6 (Il6) by lipopolysaccharide (LPS)-activated macrophages. In addition, 4-OHDHA-treated mice when compared to control mice not receiving treatment recovered better from the weight loss caused by DSS-induced colitis. Changes in disease activity index (DAI) of 4-OHDHA-treated mice were also more favorable than for control mice and were comparable with mice treated with a typical anti-inflammatory-drug, 5-aminosalichylic acid (5-ASA). These results suggest that 4-OHDHA has potentially clinically useful anti-inflammatory effects mediated by suppression of inflammatory gene expression.

  10. Chemical synthesis, docking studies and biological effects of a pan peroxisome proliferator-activated receptor agonist and cyclooxygenase inhibitor.

    PubMed

    Santin, José Roberto; Uchôa, Flávia D T; Lima, Maria do Carmo A; Rabello, Marcelo M; Machado, Isabel Daufenback; Hernandes, Marcelo Z; Amato, Angelica A; Milton, Flora Aparecida; Webb, Paul; Neves, Francisco de Assis Rocha; Galdino, Suely L; Pitta, Ivan Rocha; Farsky, Sandra H P

    2013-03-12

    The compound (5Z)-5-[(5-bromo-1H-indol-3-yl)methylene]-3-(4-chlorobenzyl)-thiazolidine-2,4-dione (LYSO-7) was synthesised in order to obtain a new type of anti-inflammatory drug, designed with hybrid features to inhibit cyclooxygenase (COX) and also to activate peroxisome proliferator-activated receptor (PPAR). Results obtained from docking (in silico) studies corroborated with experimental data, showing the potential affinity between the studied ligand and targets. The specificity of LYSO-7 for COX-enzymes was detected by the inhibition of COX-1 and COX-2 activities by 30% and 20%, respectively. In transactivation reporter gene assays LYSO-07 showed a pan partial agonist effect on the three PPAR subtypes (PPARγ, PPARα and PPARβ/δ). The agonist action on PPARγ was also observed by a pharmacological approach, as the reduction in the Escherichia coli lipopolysaccharide (LPS)-induced interleukin 1 beta (IL-1β) secretion and nitric oxide (NO) production by mouse neutrophils was blocked by GW9962, a specific PPARγ antagonist. Additionally, the in vivo effect was measured by reduced carrageenan-induced neutrophil influx into the subcutaneous tissue of mice. Taken together, these data show that LYSO-7 displays a potent in vivo anti-inflammatory effect during the innate acute response, which is dependent on its associated COX inhibitory activities and PPAR activation. PMID:23305993

  11. Effect of feeding fermented soybean meal on plasma concentration of cortisol in LPS-challenged nursery pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the present study was to determine if feeding nursery pigs diets containing either plasma protein (PP) or fermented soybean meal (FSBM) would alter the overall stress response to a lipopolysaccharide (LPS) challenge as indicated by plasma concentrations of cortisol. Pigs (n=24) were...

  12. Citrus polymethoxylated flavone inhibition of tumor necrosis factor-alpha in LPS-challenged mice and human monocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus flavonoids have been investigated for their biological actions in animals, particularly for their anti-cancer effects, and for their cholesterol-lowering and anti-inflammatory properties. An investigation of the production of cytokines in bacterial lipopolysaccharide (LPS)-treated human mono...

  13. LPS-mediated endothelial activation in pulmonary endothelial cells: role of Nox2-dependent IKK-β phosphorylation

    PubMed Central

    Menden, Heather; Tate, Everett; Hogg, Neil

    2013-01-01

    Lipopolysaccharide (LPS)-mediated endothelial activation contributes to lung inflammation and alveolar remodeling seen in premature infants with bronchopulmonary dysplasia (BPD). The mechanisms underlying LPS-mediated oxidative stress and proinflammatory signaling in human pulmonary microvascular endothelial cells (HPMEC) remain unclear. We hypothesized that NADPH oxidase (Nox) mediates LPS-induced endothelial activation in HPMEC by regulating phosphorylation of Toll-like receptor (TLR) pathway proteins. LPS-induced expression of intercellular adhesion molecule 1 (ICAM-1) was associated with increased 2-OH-E+ (marker for superoxide formation) levels and was attenuated by apocynin and the Nox inhibitor, VAS2870. LPS triggered membrane translocation of p67phox, suggesting activation of Nox2. Silencing Nox2, but not Nox4, suppressed LPS-induced ICAM-1 expression in HPMEC. Immunoprecipitation studies showed that inhibitor of κ-B kinase-β (IKK-β) serine phosphorylation induced by LPS was inhibited by Nox2 silencing. We examined whether Nox2-dependent, LPS-mediated IKK-β phosphorylation was regulated by protein phosphatase 2A (PP2A) or TGF-β associated kinase-1 (TAK1) in HPMEC. LPS increased PP2A activity in HPMEC, and inhibition of PP2A did not alter LPS-mediated ICAM-1 expression but attenuated IKK-β phosphorylation. TAK1 inhibition decreased LPS-induced ICAM-1 expression in HPMEC, and Nox2 silencing attenuated LPS-mediated TAK1 phosphorylation (Thr184/187). We demonstrate that Nox2 regulates LPS-mediated endothelial activation in pulmonary endothelial cells by modulating phosphorylation of key kinases in the TLR signaling cascade. Our data support a novel mechanism by which Nox-dependent signaling regulates proinflammatory signaling in pulmonary endothelial cells. Inhibition of vascular Nox may potentially limit lung injury and alveolar remodeling caused by infections in BPD. PMID:23333803

  14. Protective effect of carvacrol on acute lung injury induced by lipopolysaccharide in mice.

    PubMed

    Feng, Xiaosheng; Jia, Aiqing

    2014-08-01

    Carvacrol, the major component of Plectranthus amboinicus, has been known to exhibit anti-inflammatory activities. The aim of this study was to investigate the effects of carvacrol on lipopolysaccharide (LPS)-induced endotoxemia and acute lung injury (ALI) in mice. Mice were injected intraperitoneally (i.p.) with LPS and the mortality of mice for 7 days were observed twice a day. Meanwhile, the protective effect of carvacrol (20, 40 or 80 mg/kg) on LPS-induced endotoxemia were detected. Using an experimental model of LPS-induced ALI, we examined the effect of carvacrol in resolving lung injury. The results showed that carvacrol could improve survival during lethal endotoxemia and attenuate LPS-induced ALI in mice. The anti-inflammatory mechanisms of carvacrol may be due to its ability to inhibit NF-κB and MAPKs signaling pathways, thereby inhibiting inflammatory cytokines TNF-α, IL-6 and IL-1β production. PMID:24577726

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

    PubMed

    Pardon, Marie Christine

    2015-01-01

    Lipopolysaccharide (LPS) endotoxins are widely used as experimental models of systemic bacterial infection and trigger robust inflammation by potently activating toll-like receptors 4 (TLR4) expressed on innate immune cells. Their ability to trigger robust neuroinflammation despite poor brain penetration can prove useful for the understanding of how inflammation induced by viral infections contributes to the pathogenesis of neurodegenerative diseases. A single LPS challenge often result in a blunted inflammatory response to subsequent stimulation by LPS and other TLR ligands, but the extent to which endotoxin tolerance occur in the brain requires further clarification. LPS is also thought to render the brain transiently resistant to subsequent brain injuries by attenuating the concomitant pro-inflammatory response. While LPS hyporesponsiveness and preconditioning are classically seen as protective mechanisms limiting the toxic effects of sustained inflammation, recent research casts doubt as to whether they have beneficial or detrimental roles on the brain and in neurodegenerative disease. These observations suggest that spatio-temporal aspects of the immune responses to LPS and the disease status are determinant factors. Endotoxin tolerance may lead to a late pro-inflammatory response with potential harmful consequences. And while reduced TLR4 signaling reduces the risk of neurodegenerative diseases, up-regulation of anti-inflammatory cytokines associated with LPS hyporesponsiveness can have deleterious consequences to the brain by inhibiting the protective phenotype of microglia, aggravating the progression of some neurodegenerative conditions such as Alzheimer's disease. Beneficial effects of LPS preconditioning, however appear to require a stimulation of anti-inflammatory mediators rather than an attenuation of the pro-inflammatory response. PMID:26662122

  16. Inhibition of acute lung injury by rubriflordilactone in LPS-induced rat model through suppression of inflammatory factor expression

    PubMed Central

    Wang, Yan-Ying; Qiu, Xin-Guang; Ren, Hong-Liang

    2015-01-01

    The present study demonstrates the effect of rubriflordilactone on lipopolysaccharide (LPS)-induced acute kidney injury in rats and MLE-15 cells. LPS administration in rats resulted in formation of edema which was inhibited by pretreatment with rubriflordilactone. The pulmonary tissues of LPS administered rats and MLE-15 cells showed a significant increase in the expression of matrix metalloproteinase-9, interleukin-6 and inducible nitric oxide synthase. However, rubriflordilactone treatment prior to LPS administration caused a significant reduction in the expression of these factors at a concentration of 10 nm/kg. Analysis of the Sirtuin 1 (Sirt1) expression revealed significant (P=0.002) reduction on exposure to LPS in MLE-15 cells. However, rubriflordilactone treatment at 10 nm/ml concentration before LPS exposure caused inhibition of LPS induced reduction in Sirt1 expression. Silencing of Sirt1 by siRNA in MLE-15 cells led to inhibition of increased Sirt1 expression by rubriflordilactone in LPS administered rats. These findings suggest that rubriflordilactone inhibits LPS induced acute lung injury in rats and MLE-15 cells through promotion of Sirt1 expression. PMID:26884869

  17. Inhibition of acute lung injury by rubriflordilactone in LPS-induced rat model through suppression of inflammatory factor expression.

    PubMed

    Wang, Yan-Ying; Qiu, Xin-Guang; Ren, Hong-Liang

    2015-01-01

    The present study demonstrates the effect of rubriflordilactone on lipopolysaccharide (LPS)-induced acute kidney injury in rats and MLE-15 cells. LPS administration in rats resulted in formation of edema which was inhibited by pretreatment with rubriflordilactone. The pulmonary tissues of LPS administered rats and MLE-15 cells showed a significant increase in the expression of matrix metalloproteinase-9, interleukin-6 and inducible nitric oxide synthase. However, rubriflordilactone treatment prior to LPS administration caused a significant reduction in the expression of these factors at a concentration of 10 nm/kg. Analysis of the Sirtuin 1 (Sirt1) expression revealed significant (P=0.002) reduction on exposure to LPS in MLE-15 cells. However, rubriflordilactone treatment at 10 nm/ml concentration before LPS exposure caused inhibition of LPS induced reduction in Sirt1 expression. Silencing of Sirt1 by siRNA in MLE-15 cells led to inhibition of increased Sirt1 expression by rubriflordilactone in LPS administered rats. These findings suggest that rubriflordilactone inhibits LPS induced acute lung injury in rats and MLE-15 cells through promotion of Sirt1 expression. PMID:26884869

  18. Probucol via inhibition of NHE1 attenuates LPS-accelerated atherosclerosis and promotes plaque stability in vivo.

    PubMed

    Li, Jian-Fei; Chen, Song; Feng, Jun-Duo; Zhang, Ming-Yu; Liu, Xiao-Xia

    2014-04-01

    Activation of Na(+)/H(+) exchanger 1 (NHE1) by lipopolysaccharide (LPS) via Ca(2+)/calpain is responsible in vascular smooth muscle cell (VSMC) apoptosis and to the process of atherosclerosis. Probucol is a lipid-lowering drug which has an anti-atherosclerosis effect. The mechanism remains poorly understood. Here we hypothesized that probucol via inhibition of NHE1 in VSMCs attenuates LPS-accelerated atherosclerosis and promotes plaque stability. Our results revealed that treatment of VSMCs with LPS increased the NHE1 activity in a time-dependent manner, associated with the increased Ca(2+)i. Probucol inhibited the LPS-induced increase of NHE1 activity in a dose-dependent manner in VSMCs for 24-hour co-incubation, as well as the change of Ca(2+)i. In addition, LPS enhanced the calpain activity. Both probucol and calcium chelation of Ca(2+) abolished the LPS-induced increase of calpain activity. Treatment of VSMCs with LPS reduced the expression of Bcl-2 without altering the mRNA level. Probucol inhibited the LPS-reduced expression of Bcl-2 protein in VSMCs. Animal studies indicated administration of probucol suppressed LPS-accelerated apoptosis, atherosclerosis and plaque instability in Apoe(-/-) mice. In conclusion, probucol via inhibition of NHE1 attenuates atherosclerosis lesion growth and promotes plaque stability. PMID:24594116

  19. Heterogeneous Porphyromonas gingivalis LPS modulates immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in human gingival fibroblasts

    PubMed Central

    Herath, Thanuja D. K.; Darveau, Richard P.; Seneviratne, Chaminda J.; Wang, Cun-Yu; Wang, Yu; Jin, Lijian

    2016-01-01

    Periodontal (gum) disease is a highly prevalent infection and inflammation accounting for the majority of tooth loss in adult population worldwide. Porphyromonas gingivalis is a keystone periodontal pathogen and its lipopolysaccharide (PgLPS) acts as a major virulence attribute to the disease. Herein, we deciphered the overall host response of human gingival fibroblasts (HGFs) to two featured isoforms of tetra-acylated PgLPS1435/1449 and penta-acylated PgLPS1690 with reference to E. coli LPS through quantitative proteomics. This study unraveled differentially expressed novel biomarkers of immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs. PgLPS1690 greatly upregulated inflammatory proteins (e.g. cyclophilin, inducible nitric oxide synthase, annexins, galectin, cathepsins and heat shock proteins), whereas the anti-inflammatory proteins (e.g. Annexin A2 and Annexin A6) were significantly upregulated by PgLPS1435/1449. Interestingly, the antioxidants proteins such as mitochondrial manganese-containing superoxide dismutase and peroxiredoxin 5 were only upregulated by PgLPS1690. The cytoskeletal rearrangement-related proteins like myosin were differentially regulated by these PgLPS isoforms. The present study gives new insight into the biological properties of P. gingivalis LPS lipid A moiety that could critically modulate immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs, and thereby enhances our understanding of periodontal pathogenesis. PMID:27538450

  20. Heterogeneous Porphyromonas gingivalis LPS modulates immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in human gingival fibroblasts.

    PubMed

    Herath, Thanuja D K; Darveau, Richard P; Seneviratne, Chaminda J; Wang, Cun-Yu; Wang, Yu; Jin, Lijian

    2016-01-01

    Periodontal (gum) disease is a highly prevalent infection and inflammation accounting for the majority of tooth loss in adult population worldwide. Porphyromonas gingivalis is a keystone periodontal pathogen and its lipopolysaccharide (PgLPS) acts as a major virulence attribute to the disease. Herein, we deciphered the overall host response of human gingival fibroblasts (HGFs) to two featured isoforms of tetra-acylated PgLPS1435/1449 and penta-acylated PgLPS1690 with reference to E. coli LPS through quantitative proteomics. This study unraveled differentially expressed novel biomarkers of immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs. PgLPS1690 greatly upregulated inflammatory proteins (e.g. cyclophilin, inducible nitric oxide synthase, annexins, galectin, cathepsins and heat shock proteins), whereas the anti-inflammatory proteins (e.g. Annexin A2 and Annexin A6) were significantly upregulated by PgLPS1435/1449. Interestingly, the antioxidants proteins such as mitochondrial manganese-containing superoxide dismutase and peroxiredoxin 5 were only upregulated by PgLPS1690. The cytoskeletal rearrangement-related proteins like myosin were differentially regulated by these PgLPS isoforms. The present study gives new insight into the biological properties of P. gingivalis LPS lipid A moiety that could critically modulate immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs, and thereby enhances our understanding of periodontal pathogenesis. PMID:27538450

  1. Effect of prenatal stress on subsequent response to mixing stress and a lipopolysaccharide challenge in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sows subjected to prenatal stress have been found to produce offspring that alter the manner in which they respond to stress. Our objective was to determine if exposing a sow to stress altered the response of the offspring to lipopolysaccharide (LPS) at 2 mo of age or their response to mixing stres...

  2. Arginine supplementation does not alter nitrogen metabolism of beef steers during a lipopolysaccharide challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for Arg is reported to increase during immune challenge. This study evaluated the effects of lipopolysaccharide (LPS) and abomasal Arg infusion on N metabolism and immune response of 20 ruminally cannulated steers (369 ± 46 kg BW) in a randomized block design. Each block was 20 d and consiste...

  3. Effect of Sodium Butyrate on Growth Performance and Response to Lipopolysaccharide in Weanling Pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to determine the effects of dietary sodium butyrate on growth performance and response to E. coli. lipopolysaccharide (LPS) in weanling pigs. In the first 28 d experiment, 180 pigs (initial BW 6.3 kg) were fed 0, 0.05, 0.1, 0.2, and 0.4% sodium butyrate, or 110 mg/kg d...

  4. Arginine supplementation does not alter nitrogen metabolism of beef steers during a lipopolysaccharide challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for arginine (Arg) is reported to increase during immune challenges. This study evaluated effects of lipopolysaccharide (LPS) and abomasal Arg infusion on nitrogen (N) metabolism and immune response of 20 ruminally cannulated steers (369 ± 46 kg BW) in a randomized block design. Each block co...

  5. Milk Thistle Extract and Silymarin Inhibit Lipopolysaccharide Induced Lamellar Separation of Hoof Explants in Vitro

    PubMed Central

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2014-01-01

    The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

  6. Milk thistle extract and silymarin inhibit lipopolysaccharide induced lamellar separation of hoof explants in vitro.

    PubMed

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2014-10-01

    The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

  7. Effect of low doses of lipopolysaccharide prior to ozone exposure on bronchoalveolar lavage

    PubMed Central

    Haque, Rizwanul; Umstead, Todd M.; Ahn, Kwangmi; Phelps, David S.; Floros, Joanna

    2010-01-01

    SUMMARY Background Several aspects of the inflammatory response to a single insult, i.e., exposure to 2 ppm of ozone (O3) for 3 h or 6 h, are less pronounced in surfactant protein A deficient (SP-A −/−) mice (KO) than in wild type mice (WT). It was hypothesized that a mild insult, specifically low doses of lipopolysaccharide (LPS), would adversely affect host defense and differentially potentiate O3-induced injury in WT and KO mice. METHODS WT and KO mice were treated with different doses of LPS or LPS (2 ng) + O3 (2 ppm) or filtered air (FA) for 3 h, then sacrificed 4 h following exposure (O3, FA) or 20 h after LPS treatment alone. Several endpoints of inflammation were measured in bronchoalveolar lavage (BAL). RESULTS 1) At 20 h after LPS treatment alone, both WT and KO mice exhibited signs of inflammation, but with differences in the macrophage inflammatory protein 2 (MIP-2) response pattern, total cells (at 0.5 ng LPS) and basal levels of oxidized protein and phospholipids; 2) After LPS + O3, KO compared to WT showed decrease in polymorphonuclear leukocytes (PMNs) and MIP-2 and increase in phospholipids, and after LPS + FA an increase in total cells; 3) WT after LPS + FA showed an increase in SP-A with no further increase after LPS + O3, and an increase in oxidized SP-A dimer following O3 or LPS + O3. CONCLUSIONS LPS treatment has negative effects on inflammation endpoints in mouse BAL long after exposure and renders KO mice less capable of responding to a second insult. LPS and O3 affect SP-A, quantitatively and qualitatively, respectively. PMID:21278811

  8. Aryl hydrocarbon receptor mediates both proinflammatory and anti-inflammatory effects in lipopolysaccharide-activated microglia.

    PubMed

    Lee, Yi-Hsuan; Lin, Chun-Hua; Hsu, Pei-Chien; Sun, Yu-Yo; Huang, Yu-Jie; Zhuo, Jiun-Horng; Wang, Chen-Yu; Gan, Yu-Ling; Hung, Chia-Chi; Kuan, Chia-Yi; Shie, Feng-Shiun

    2015-07-01

    The aryl hydrocarbon receptor (AhR) regulates peripheral immunity; but its role in microglia-mediated neuroinflammation in the brain remains unknown. Here, we demonstrate that AhR mediates both anti-inflammatory and proinflammatory effects in lipopolysaccharide (LPS)-activated microglia. Activation of AhR by its ligands, formylindolo[3,2-b]carbazole (FICZ) or 3-methylcholanthrene (3MC), attenuated LPS-induced microglial immune responses. AhR also showed proinflammatory effects, as evidenced by the findings that genetic silence of AhR ameliorated the LPS-induced microglial immune responses and LPS-activated microglia-mediated neurotoxicity. Similarly, LPS-induced expressions of tumor necrosis factor α (TNFα) and inducible nitric oxide synthase (iNOS) were reduced in the cerebral cortex of AhR-deficient mice. Intriguingly, LPS upregulated and activated AhR in the absence of AhR ligands via the MEK1/2 signaling pathway, which effects were associated with a transient inhibition of cytochrome P450 1A1 (CYP1A1). Although AhR ligands synergistically enhance LPS-induced AhR activation, leading to suppression of LPS-induced microglial immune responses, they cannot do so on their own in microglia. Chromatin immunoprecipitation results further revealed that LPS-FICZ co-treatment, but not LPS alone, not only resulted in co-recruitment of both AhR and NFκB onto the κB site of TNFα gene promoter but also reduced LPS-induced AhR binding to the DRE site of iNOS gene promoter. Together, we provide evidence showing that microglial AhR, which can be activated by LPS, exerts bi-directional effects on the regulation of LPS-induced neuroinflammation, depending on the availability of external AhR ligands. These findings confer further insights into the potential link between environmental factors and the inflammatory brain disorders. PMID:25690886

  9. Effect of synthetic agonists of toll-like receptor 9 on canine lymphocyte proliferation and cytokine production in vitro.

    PubMed

    Im Hof, Michelle; Williamson, Lina; Summerfield, Artur; Balmer, Vreni; Dutoit, Virginie; Kandimalla, Ekambar R; Yu, Dong; Zurbriggen, Andreas; Doherr, Marcus G; Peel, John; Roosje, Petra J

    2008-07-15

    Synthetic agonists of TLR9 containing novel DNA structures and R'pG (wherein R=1-(2'-deoxy-beta-d-ribofuranosyl)-2-oxo-7-deaza-8-methyl-purine) motifs, referred to as immune modulatory oligonucleotides (IMOs), have been shown to stimulate T(H)-1-type-immune responses and potently reverse allergen-induced T(H)-2 responses to T(H)-1 responses in vitro and in vivo in mice. In order to investigate the immunomodulatory potential of IMOs in dogs, canine peripheral blood mononuclear cells (PBMC) from healthy dogs were stimulated with three different IMOs and a control IMO, alone or in combination with concanavalin A (ConA). Lipopolysaccharide (LPS) was used as a positive control for B lymphocyte activation. Carboxyfluorescein diacetate succinimidyl ester and phenotype staining was used to tag proliferating T and B lymphocytes (CD5(+) and CD21(+)) by flow cytometry. Real-time PCR and ELISA were processed to assay cytokine production of IFN-gamma, IL-10, TGF-beta, IL-6 and IL-10. Like LPS, IMOs alone induced neither proliferation of CD5(+) T cells nor CD21(+) B cells, but both LPS and IMO had the capacity to co-stimulate ConA and induced proliferation of B cells. In combination with ConA, one of the IMOs (IMO1) also induced proliferation of T cells. IMO1 also significantly enhanced the expression of IFN-gamma on the mRNA and protein level in canine PBMC, whereas expression of IL-10, TGF-beta and IL-4 mRNAs was not induced by any of the IMOs. These results indicate that in canine PBMC from healthy dogs, IMO1 was able to induce a T(H)-1 immune response including T- and B-cell proliferation. PMID:18452997

  10. Carrageenans effect on neutrophils alone and in combination with LPS in vitro.

    PubMed

    Sokolova, E V; Karetin, Y; Davydova, V N; Byankina, A O; Kalitnik, A A; Bogdanovich, L N; Yermak, I M

    2016-07-01

    Influence of sulfated red algal polysaccharides (κ-, λ-, and κ/β-carrageenans) and degraded derivative of κ/β-carrageenan on neutrophils/monocytes activation alone and in combination with lipopolysaccharide was investigated by means of determination of reactive oxygen species production, latex microparticles engulfment, total and extracellular myeloperoxidase induction and the analysis of silhouette and contour two-dimensional images of flattened cells. Carrageenans alone can activate neutrophils with much less potency than lipopolysaccharide (LPS) and the sulfation degree of carrageenans stipulates high activity in this role. On the other hand, carrageenans especially with low contents of sulfate groups are able to interfere with LPS in vitro resulting in reducing inter- and intracellular activation of neutrophils killing mechanisms. Further research is necessary to relate these findings to actions on the whole animal or human in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1603-1609, 2016. PMID:26915063

  11. The antimicrobial antiproteinase elafin binds to lipopolysaccharide and modulates macrophage responses.

    PubMed

    McMichael, Jonathan W; Roghanian, Ali; Jiang, Lu; Ramage, Robert; Sallenave, Jean-Michel

    2005-05-01

    Lipopolysaccharides (LPS) of the outer membrane of Gram-negative bacteria represent a primary target for innate immune responses. We demonstrate here that the antimicrobial/anti-neutrophil elastase full-length elafin (FL-EL) is able to bind both smooth and rough forms of LPS. The N-terminus was shown to bind both forms of LPS more avidly. We demonstrate that the lipid A core-binding proteins polymyxin B (PB) and LPS-binding protein (LBP) compete with elafin for binding, and that LBP is able to displace prebound elafin from LPS. When PB, FL-EL, N-EL, and C-EL were pre-incubated with LPS before addition to immobilized LBP, PB was the most potent inhibitor of LPS transfer to LBP. These data prompted us to examine the biological consequences of elafin binding to LPS, using tumor necrosis factor (TNF)-alpha release by murine macrophages. In serum-containing conditions, N-EL had no effect, whereas both C-EL and FL-EL inhibited TNF-alpha production. In serum-free conditions, however, all moieties had a stimulatory activity on TNF-alpha release, with C-EL being the most potent at the highest concentration. The differential biological activity of elafin in different conditions suggests a role for this molecule in either LPS detoxification or activation of innate immune responses, depending on the external cellular environment. PMID:15668324

  12. Bacterial lipopolysaccharides prime human neutrophils for enhanced production of leukotriene B4.

    PubMed Central

    Doerfler, M E; Danner, R L; Shelhamer, J H; Parrillo, J E

    1989-01-01

    Neutrophils can be "primed" for an enhanced respiratory burst by lipopolysaccharide (LPS) in concentrations measurable in patients with septic shock. Leukotriene B4 (LTB4) is the primary eicosanoid product of neutrophils and is felt to be a mediator of host defense and inflammation. We investigated the in vitro effects of LPS on neutrophil production of LTB4 and the omega-oxidation metabolites of LTB4. Incubation of neutrophils with LPS in concentrations ranging from 0.01 to 100 ng/ml did not result in production of LTB4 or metabolites in the absence of a second stimulus. Priming neutrophils with LPS and then stimulating with opsonized zymosan, phorbol-myristate-acetate or a low concentration of the calcium ionophore A23187 resulted in enhanced production of LTB4. LPS priming of neutrophils occurred in a concentration dependent manner. LPS did not result in LTB4 production in response to the chemoattractant peptide FMLP. LPS priming of neutrophils had no effect on cytosolic calcium concentrations of resting or zymosan-stimulated cells. These results suggest that LPS might effect host defense and tissue injury by potentiating the effect of other stimulants on neutrophil production of LTB4. This LPS induced enhancement may represent an important pathogenetic pathway in patients with gram negative sepsis. PMID:2537852

  13. The Aeromonas salmonicida Lipopolysaccharide Core from Different Subspecies: The Unusual subsp. pectinolytica.

    PubMed

    Merino, Susana; Tomás, Juan M

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses. PMID:26904002

  14. Synthesis, characterization and immunological properties of Escherichia coli 0157:H7 lipopolysaccharide- diphtheria toxoid conjugate vaccine

    PubMed Central

    Rokhsartalab-Azar, Shadi; Shapouri, Reza; Rahnema, Mehdi; Najafzadeh, Faezeh

    2015-01-01

    Background and Objective: Escherichia coli O157:H7, an emerging pathogen, causes severe enteritis and the extraintestinal complication of hemolytic-uremic syndrome. The goal of this study was to evaluate the conjugate of E. coli O157: H7 lipopolysaccharide (LPS) with diphtheria toxoid (DT) as a candidate vaccine in mice model. Material and Methods: LPS from E. coli O157:H7 was extracted by hot phenol method and then detoxified. Purified LPS was coupled to DT with adipic acid dihydrazide (ADH) as a spacer and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as a linker. The coupling molar ratio of LPS to DT was 3:1. Clinical evaluation of E. coli O157:H7 LPS-DT conjugate was also performed. Results: The conjugate was devoid of endotoxin activity and indicated 0.125 U/ml of D-LPS. Mice immunization with D-LPS DT conjugate elicited fourfold higher IgG antibody in comparison to D-LPS. Also, in vivo protection of mice with conjugate provided high protection against the LD50 of E. coli O157:H7, which indicated a good correlation with the IgG titer. Conclusion: Our results showed that the suggested vaccine composed of E. coli O157:H7 LPS and DT had a significant potential to protect against E. coli infections. PMID:26668702

  15. Effects of Citral on Lipopolysaccharide-Induced Inflammation in Human Umbilical Vein Endothelial Cells.

    PubMed

    Song, Yan; Zhao, Hongfeng; Liu, Jinyang; Fang, Chao; Miao, Renying

    2016-04-01

    Citral is an active compound of lemongrass oil which has been reported to have anti-inflammatory effects. In this study, we investigated the effects of citral on lipopolysaccharide (LPS)-induced inflammatory response in a rat model of peritonitis and human umbilical vein endothelial cells (HUVECs). LPS was intraperitoneally injected into rats to establish a peritonitis model. The HUVECs were treated with citral for 12 h before exposure to LPS. The levels of TNF-α and IL-8 were measured using ELISA. Western blotting was used to detect the expression of VCAM-1, ICAM-1, NF-κB, and PPAR-γ. The results showed that citral had a protective effect against LPS-induced peritonitis. Citral decreased the levels of WBCs and inflammatory cytokines TNF-α and IL-6. Citral also inhibited LPS-induced myeloperoxidase (MPO) activity in the peritoneal tissue. Treatment of HUVECs with citral significantly inhibited TNF-α and IL-8 expression induced by LPS. LPS-induced VCAM-1 and ICAM-1 expression were also suppressed by citral. Meanwhile, we found that citral inhibited LPS-induced NF-κB activation in HUVECs. Furthermore, we found that citral activated PPAR-γ and the anti-inflammatory effects of citral can be reversed by PPAR-γ antagonist GW9662. In conclusion, citral inhibits LPS-induced inflammatory response via activating PPAR-γ which attenuates NF-κB activation and inflammatory mediator production. PMID:26658749

  16. The Aeromonas salmonicida Lipopolysaccharide Core from Different Subspecies: The Unusual subsp. pectinolytica

    PubMed Central

    Merino, Susana; Tomás, Juan M.

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses. PMID:26904002

  17. Role of NF-κB-dependent Caveolin-1 Expression in the Mechanism of Increased Endothelial Permeability Induced by Lipopolysaccharide*S

    PubMed Central

    Tiruppathi, Chinnaswamy; Shimizu, Jun; Miyawaki-Shimizu, Kayo; Vogel, Stephen M.; Bair, Angela M.; Minshall, Richard D.; Predescu, Dan; Malik, Asrar B.

    2008-01-01

    We investigated the role of NF-κB activation by the bacterial product lipopolysaccharide (LPS) in inducing caveolin-1 (Cav-1) expression and its consequence in contributing to the leakiness of the endothelial barrier. We observed that LPS challenge of human lung microvascular endothelial cells induced concentration- and time-dependent increases in expression of Cav-1 mRNA and protein. The NEMO (NF-κB essential modifier binding domain)-binding domain peptide (IkB kinase (IKK)-NEMO-binding domain (NBD) peptide), which prevents NF-κB activation by inhibiting the interaction of IKKγ with the IKK complex, blocked LPS-induced Cav-1 mRNA and protein expression. Knockdown of NF-κB subunit p65/RelA expression with small interfering RNA also prevented LPS-induced Cav-1 expression. Caveolae open to the apical and basal plasmalemma of endothelial cells increased 2–4-fold within 4 h of LPS exposure. IKK-NBD peptide markedly reduced the LPS-induced increase in the number of caveolae as well as transendothelial albumin permeability. These observations were recapitulated in mouse studies in which IKK-NBD peptide prevented Cav-1 expression and interfered with the increase in lung microvessel permeability induced by LPS. Thus, LPS mediates NF-κB-dependent Cav-1 expression that results in increased caveolae number and thereby contributes to the mechanism of increased transendothelial albumin permeability. PMID:18077459

  18. Effects of cyanobacterial lipopolysaccharides from microcystis on glutathione-based detoxification pathways in the zebrafish (Danio rerio) embryo.

    PubMed

    Jaja-Chimedza, Asha; Gantar, Miroslav; Mayer, Gregory D; Gibbs, Patrick D L; Berry, John P

    2012-06-01

    Cyanobacteria ("blue-green algae") are recognized producers of a diverse array of toxic secondary metabolites. Of these, the lipopolysaccharides (LPS), produced by all cyanobacteria, remain to be well investigated. In the current study, we specifically employed the zebrafish (Danio rerio) embryo to investigate the effects of LPS from geographically diverse strains of the widespread cyanobacterial genus, Microcystis, on several detoxifying enzymes/pathways, including glutathione-S-transferase (GST), glutathione peroxidase (GPx)/glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT), and compared observed effects to those of heterotrophic bacterial (i.e., E. coli) LPS. In agreement with previous studies, cyanobacterial LPS significantly reduced GST in embryos exposed to LPS in all treatments. In contrast, GPx moderately increased in embryos exposed to LPS, with no effect on reciprocal GR activity. Interestingly, total glutathione levels were elevated in embryos exposed to Microcystis LPS, but the relative levels of reduced and oxidized glutathione (i.e., GSH/GSSG) were, likewise, elevated suggesting that oxidative stress is not involved in the observed effects as typical of heterotrophic bacterial LPS in mammalian systems. In further support of this, no effect was observed with respect to CAT or SOD activity. These findings demonstrate that Microcystis LPS affects glutathione-based detoxification pathways in the zebrafish embryo, and more generally, that this model is well suited for investigating the apparent toxicophore of cyanobacterial LPS, including possible differences in structure-activity relationships between heterotrophic and cyanobacterial LPS, and teleost fish versus mammalian systems. PMID:22822454

  19. Induction of hepatocyte lipopolysaccharide binding protein in models of sepsis and the acute-phase response.

    PubMed

    Geller, D A; Kispert, P H; Su, G L; Wang, S C; Di Silvio, M; Tweardy, D J; Billiar, T R; Simmons, R L

    1993-01-01

    Lipopolysaccharide binding protein (LBP) is a serum glycoprotein that complexes with lipopolysaccharide (LPS) to facilitate macrophage response to endotoxin. To determine the conditions that stimulate LBP production in vivo, we measured the induction of LBP in models of inflammation produced by LPS, Corynebacterium parvum, and turpentine injection. Plasma aspartate aminotransferase and alanine aminotransferase concentrations and hepatocyte fibrinogen synthesis were elevated in all models. Northern blot analysis revealed 17-, 14-, and 20-fold upregulation of hepatocyte LBP mRNA following treatment with LPS, C parvum, and turpentine, respectively. Peritoneal macrophage interleukin 6 and tumor necrosis factor production following endotoxin stimulation was augmented by cultured hepatocyte supernatants, suggesting increased LBP synthesis in these groups. The results show that LBP mRNA is induced during hepatic inflammation and suggest that LBP is an acute-phase protein important in regulating the in vivo response to endotoxin. PMID:8418776

  20. The N-terminal half of membrane CD14 is a functional cellular lipopolysaccharide receptor.

    PubMed Central

    Viriyakosol, S; Kirkland, T N

    1996-01-01

    CD14, a glycosylphosphatidylinositol-anchored protein on the surface of monocytes, macrophages, and polymorphonuclear leukocytes, is a receptor for lipopolysaccharide (LPS). It was recently reported that an N-terminal 152-amino-acid fragment of soluble CD14 was an active soluble lipopolysaccharide receptor (T. S. -C. Juan, M. J. Kelley, D. A. Johnson, L. A. Busse, E. Hailman, S. D. Wright, and H. S. Lichenstein, J. Biol. Chem. 270:1382-1387, 1995). To determine whether the N-terminal half of the membrane CD14 was a functional LPS receptor on the cell membrane, we engineered a chimeric gene coding for amino acids 1 to 151 of CD14 fused to the C-terminal region of decay-accelerating factor and expressed it in Chinese hamster ovary cells and 70Z/3 cells. We found that the chimeric, truncated CD14 is a fully functional LPS receptor in both cell lines. PMID:8550221

  1. Consequences of Alteration in Leucine Zipper Sequence of Melittin in Its Neutralization of Lipopolysaccharide-induced Proinflammatory Response in Macrophage Cells and Interaction with Lipopolysaccharide*

    PubMed Central

    Srivastava, Raghvendra M.; Srivastava, Saurabh; Singh, Manish; Bajpai, Virendra Kumar; Ghosh, Jimut Kanti

    2012-01-01

    The bee venom antimicrobial peptide, melittin, besides showing versatile activity against microorganisms also neutralizes lipopolysaccharide (LPS)-induced proinflammatory responses in macrophage cells. However, how the amino acid sequence of melittin contributes in its anti-inflammatory properties is mostly unknown. To determine the importance of the leucine zipper sequence of melittin in its neutralization of LPS-induced inflammatory responses in macrophages and interaction with LPS, anti-inflammatory properties of melittin and its three analogues and their interactions with LPS were studied in detail. Two of these analogues, namely melittin Mut-1 (MM-1) and melittin Mut-2 (MM-2), possess leucine to alanine substitutions in the single and double heptadic leucine residue(s) of melittin, respectively, whereas the third analogue is a scrambled peptide (Mel-SCR) that contains the amino acid composition of melittin with minor rearrangement in its leucine zipper sequence. Although MM-1 partly inhibited the production of proinflammatory cytokines in RAW 264.7 and rat primary macrophage cells in the presence of LPS, MM-2 and Mel-SCR were negligibly active. A progressive decrease in interaction of melittin with LPS, aggregation in LPS, and dissociation of LPS aggregates with alteration in the leucine zipper sequence of melittin was observed. Furthermore, with alteration in the leucine zipper sequence of melittin, these analogues failed to exhibit cellular responses associated with neutralization of LPS-induced inflammatory responses in macrophage cells by melittin. The data indicated a probable important role of the leucine zipper sequence of melittin in neutralizing LPS-induced proinflammatory responses in macrophage cells as well as in its interaction with LPS. PMID:22128186

  2. AS-703026 Inhibits LPS-Induced TNFα Production through MEK/ERK Dependent and Independent Mechanisms

    PubMed Central

    Li, Ping; Wu, Yonghong; Li, Manxiang; Qiu, Xiaojuan; Bai, Xiaoyan; Zhao, Xiaojing

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is characterized by intense lung infiltrations of immune cells (macrophages and monocytes). Lipopolysaccharide (LPS) activates macrophages/monocytes, leading to production of tumor necrosis factor α (TNFα) and other cytokines, which cause subsequent lung damages. In the current study, our results demonstrated that AS-703026, a novel MEK/ERK inhibitor, suppressed LPS-induced TNFα mRNA expression and protein secretion in RAW 264.7 murine macrophages, and in murine bone marrow-derived macrophages (BMDMs). Meanwhile, TNFα production in LPS-stimulated COPD patents’ peripheral blood mononuclear cells (PBMCs) was also repressed by AS-703026. At the molecular level, we showed that AS-703026 blocked LPS-induced MEK/ERK activation in above macrophages/monocytes. However, restoring ERK activation in AS-703026-treated RAW 264.7 cells by introducing a constitutive-actively (CA)-ERK1 only partially reinstated LPS-mediated TNFα production. Meanwhile, AS-703026 could still inhibit TNFα response in ERK1/2-depleted (by shRNA) RAW 264.7 cells. Significantly, we found that AS-703026 inhibited LPS-induced nuclear factor κB (NFκB) activation in above macrophages and COPD patients’ PBMCs. In vivo, oral administration of AS-703026 inhibited LPS-induced TNFα production and endotoxin shock in BALB/c mice. Together, we show that AS-703026 in vitro inhibits LPS-induced TNFα production in macrophages/monocytes, and in vivo protects mice from LPS-induced endotoxin shock. Thus, it could be further studied as a useful anti-inflammatory therapy for COPD patients. PMID:26381508

  3. Decreased survival of newborn neurons in the dorsal hippocampus after neonatal LPS exposure in mice☆

    PubMed Central

    Järlestedt, K.; Naylor, A.S.; Dean, J.; Hagberg, H.; Mallard, C.

    2013-01-01

    Experimental studies show that inflammation reduces the regenerative capacity in the adult brain. Less is known about how early postnatal inflammation affects neurogenesis, stem cell proliferation, cell survival and learning and memory in young adulthood. In this study we examined if an early-life inflammatory challenge alters cell proliferation and survival in distinct anatomical regions of the hippocampus and whether learning and memory were affected. Lipopolysaccharide (LPS, 1 mg/kg) was administered to mice on postnatal day (P) 9 and proliferation and survival of hippocampal cells born either prior to (24 h before LPS), or during the inflammatory insult (48 h after LPS) was evaluated. Long-term cell survival of neurons and astrocytes was determined on P 41 and P 60 in the dorsal and ventral horns of the hippocampus. On day 50 the mice were tested in the trace fear conditioning (TFC) paradigm. There was no effect on the survival of neurons and astrocytes that were born before LPS injection. In contrast, the number of neurons and astrocytes that were born after LPS injection were reduced on P 41. The LPS-induced reduction in cell numbers was specific for the dorsal hippocampus. Neither early (48 h after LPS) or late (33 days after LPS) proliferation of cells was affected by neonatal inflammation and neonatal LPS did not alter the behavior of young adult mice in the TFC test. These data highlight that neonatal inflammation specifically affects survival of dividing neurons and astrocytes, but not post-mitotic cells. The reduction in cell survival could be attributed to less cell survival in the dorsal hippocampus, but had no effect on learning and memory in the young adult. PMID:23994184

  4. LPS INHIBITION OF GLUCOSE PRODUCTION THROUGH THE TLR4, MYD88, NFκB PATHWAY

    PubMed Central

    Raetzsch, Carl F.; Brooks, Natasha L.; Alderman, J. McKee; Moore, Kelli S.; Hosick, Peter A.; Klebanov, Simon; Akira, Shizuo; Bear, James E.; Baldwin, Albert S.; Mackman, Nigel; Combs, Terry P.

    2010-01-01

    Acute exposure to lipopolysaccharide (LPS) can cause hypoglycemia and insulin resistance; the underlying mechanisms however, are unclear. We set out to determine whether insulin resistance is linked to hypoglycemia through TLR4, MyD88 and NFκB, a cell signaling pathway that mediates LPS induction of the proinflammatory cytokine TNFα. LPS induction of hypoglycemia was blocked in TLR4−/− and MyD88−/− mice but not in TNFα−/− mice. Both glucose production and glucose utilization were decreased during hypoglycemia. Hypoglycemia was associated with the activation of NFκB in the liver. LPS inhibition of glucose production was blocked in hepatocytes isolated from TLR4−/− and MyD88−/− mice and hepatoma cells expressing an IκB mutant that interferes with NFκB activation. Thus, LPS-induced hypoglycemia was mediated by the inhibition of glucose production from the liver through the TLR4, MyD88, NFκB pathway, independent of LPS induced TNFα. LPS inhibition of glucose production was not blocked by pharmacologic inhibition of the insulin signaling intermediate PI3K in hepatoma cells. Insulin injection caused a similar reduction of circulating glucose in TLR4−/− and TLR4+/+ mice. These two results suggest that LPS and insulin inhibit glucose production by separate pathways. Recovery from LPS induced hypoglycemia was linked to glucose intolerance and hyperinsulinemia in TLR4+/+ mice, but not in TLR4−/− mice. Conclusion Insulin resistance is linked to the inhibition of glucose production by the TLR4, MyD88 and NFκB pathway. PMID:19492426

  5. AS-703026 Inhibits LPS-Induced TNFα Production through MEK/ERK Dependent and Independent Mechanisms.

    PubMed

    Li, Ping; Wu, Yonghong; Li, Manxiang; Qiu, Xiaojuan; Bai, Xiaoyan; Zhao, Xiaojing

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is characterized by intense lung infiltrations of immune cells (macrophages and monocytes). Lipopolysaccharide (LPS) activates macrophages/monocytes, leading to production of tumor necrosis factor α (TNFα) and other cytokines, which cause subsequent lung damages. In the current study, our results demonstrated that AS-703026, a novel MEK/ERK inhibitor, suppressed LPS-induced TNFα mRNA expression and protein secretion in RAW 264.7 murine macrophages, and in murine bone marrow-derived macrophages (BMDMs). Meanwhile, TNFα production in LPS-stimulated COPD patents' peripheral blood mononuclear cells (PBMCs) was also repressed by AS-703026. At the molecular level, we showed that AS-703026 blocked LPS-induced MEK/ERK activation in above macrophages/monocytes. However, restoring ERK activation in AS-703026-treated RAW 264.7 cells by introducing a constitutive-actively (CA)-ERK1 only partially reinstated LPS-mediated TNFα production. Meanwhile, AS-703026 could still inhibit TNFα response in ERK1/2-depleted (by shRNA) RAW 264.7 cells. Significantly, we found that AS-703026 inhibited LPS-induced nuclear factor κB (NFκB) activation in above macrophages and COPD patients' PBMCs. In vivo, oral administration of AS-703026 inhibited LPS-induced TNFα production and endotoxin shock in BALB/c mice. Together, we show that AS-703026 in vitro inhibits LPS-induced TNFα production in macrophages/monocytes, and in vivo protects mice from LPS-induced endotoxin shock. Thus, it could be further studied as a useful anti-inflammatory therapy for COPD patients. PMID:26381508

  6. Active hexose correlated compound modulates LPS-induced hypotension and gut injury in rats.

    PubMed

    Doursout, Marie-Francoise; Liang, Yangyan; Sundaresan, Alamelu; Wakame, Koji; Fujii, Hajime; Takanari, Jun; Devakottai, Sundar; Kulkarni, Anil

    2016-10-01

    We hypothesized that AHCC; (Amino UP Chemical Co., Ltd., Sapporo, Japan), a mushroom mycelium extract obtained from liquid culture of Lentinula edodes, restores immune function in LPS-induced inflammation in the gut, especially when the nitric oxide signaling pathway is impaired. This is the first inter-disciplinary proposal to identify molecular mechanisms involved in LPS-induced immune dysfunction in the gut in conscious animals treated or non-treated with AHCC, a promoter of immune support. Specifically, we have tested the effects of AHCC on LPS-induced deleterious effects on blood pressure and gut injury in conscious rats. The time course of biological markers of innate/acquired immune responses, and inflammation/oxidative stress is fully described in the present manuscript. Rats were randomly assigned into 3 groups (N=6 per group). Group 1 received 10% of AHCC in drinking water for 5days; Group 2 received lipopolysaccharide (LPS; Escherichia coli 0111:B4 purchased from Sigma) only at 20mg/kg IV; Group 3 received combined treatments (AHCC + LPS). LPS was administered at 20mg/kg IV, 5days following AHCC treatment. We have demonstrated that AHCC decreased the LPS-deleterious effects of blood pressure and also decreased inflammatory markers e.g., cytokines, nitric oxide and edema formation. Finally, AHCC diminished lymphocyte infiltration, restoring gut architecture. Because AHCC was administered prior to LPS, our results indicate the potential impact of AHCC's prophylactic effects on LPS inflammation. Consequently, additional experiments are warrant to assess its therapeutic effects in sepsis-induced inflammation. PMID:27500458

  7. NAC Attenuates LPS-Induced Toxicity in Aspirin-Sensitized Mouse Macrophages via Suppression of Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Raza, Haider; John, Annie; Shafarin, Jasmin

    2014-01-01

    Bacterial endotoxin lipopolysaccharide (LPS) induces the production of inflammatory cytokines and reactive oxygen species (ROS) under in vivo and in vitro conditions. Acetylsalicylic acid (ASA, aspirin) is a commonly used anti-inflammatory drug. Our aim was to study the effects of N-acetyl cysteine (NAC), an antioxidant precursor of GSH synthesis, on aspirin-sensitized macrophages treated with LPS. We investigated the effects of LPS alone and in conjunction with a sub-toxic concentration of ASA, on metabolic and oxidative stress, apoptosis, and mitochondrial function using J774.2 mouse macrophage cell line. Protection from LPS-induced toxicity by NAC was also studied. LPS alone markedly induced ROS production and oxidative stress in macrophage cells. When ASA was added to LPS-treated macrophages, the increase in oxidative stress was significantly higher than that with LPS alone. Similarly, alteration in glutathione-dependent redox metabolism was also observed in macrophages after treatment with LPS and ASA. The combination of LPS and ASA selectively altered the CYP 3A4, CYP 2E1 and CYP 1A1 catalytic activities. Mitochondrial respiratory complexes and ATP production were also inhibited by LPS-ASA treatment. Furthermore a higher apoptotic cell death was also observed in LPS-ASA treated macrophages. NAC pre-treatment showed protection against oxidative stress induced apoptosis and mitochondrial dysfunction. These effects are presumed, at least in part, to be associated with alterations in NF-κB/Nrf-2 mediated cell signaling. These results suggest that macrophages are more sensitive to LPS when challenged with ASA and that NAC pre-treatment protects the macrophages from these deleterious effects. PMID:25075522

  8. Resveratrol attenuates left ventricular remodeling in old rats with COPD induced by cigarette smoke exposure and LPS instillation.

    PubMed

    Hu, Yi Xin; Cui, Hua; Fan, Li; Pan, Xiu Jie; Wu, Ji Hua; Shi, Suo Zhu; Cui, Shao Yuan; Wei, Zhi Min; Liu, Lin

    2013-12-01

    The objective of this study was to investigate left cardiac damage and the cardioprotective effects of resveratrol in old rats with COPD. Rats 22 months old were divided into three groups: control (CTL), smoking and lipopolysaccharides (SM/LPS), and SM/LPS plus resveratrol (SM/LPS-Res). Cardiac function, pathology, oxidative stress, and apoptosis index were measured. Expression of myocardial SIRT1 was studied by real-time quantitative polymerase chain reaction (PCR) and Western blot detection. The heart weight-body weight ratio (LVW/BW) increased in the SM/LPS group compared with the CTL group. Both the LVW/BW and the area of fibrosis in the SM/LPS-Res group decreased compared with those in the SM/LPS group. 8-OHdG expression increased in cardiac tissue of rats in the SM/LPS group, which could be inhibited by resveratrol. Resveratrol significantly increased the activity of superoxide dismutase (SOD) and reduced the cardiac malonyldialdehyde (MDA) level in the SM/LPS-Res group. There was a significant decrease in the extent of cardiomyocyte apoptosis in the SM/LPS-Res group compared with the SM/LPS group. SIRT1 mRNA increased in the SM/LPS-Res group compared with the SM/LPS group. In conclusion, resveratrol attenuated cardiac oxidative damage and left ventricular remodeling and enhanced the decreased expression of SIRT1 in hearts of old rats with emphysema and thus might be a therapeutic modality for cardiac injury complicated in chronic obstructive pulmonary disease (COPD). PMID:24289075

  9. High-fat diet induces site-specific unresponsiveness to LPS-stimulated STAT3 activation in the hypothalamus.

    PubMed

    Borges, Beatriz de Carvalho; Rorato, Rodrigo; Uchoa, Ernane Torres; Marangon, Paula; da Silva, Glauber S F; de Paula, Francisco José; Branco, Luiz G S; Antunes-Rodrigues, José; Elias, Lucila Leico Kagohara

    2014-01-01

    Hypophagia induced by inflammation is associated with Janus kinase (JAK)-2/signal transducer and activator of transcription (STAT) 3 signaling pathway, and leptin-mediated hypophagia is also mediated by JAK2-STAT3 pathway. We have previously reported that lipopolysaccharide (LPS) did not reduce food intake in leptin-resistant high-fat diet (HFD) rats but maintained body weight loss. We investigated whether changes in p-STAT3 expression in the hypothalamus and brain stem could account for the desensitization of hypophagia in HFD animals after a low LPS dose (100 μg/kg). Wistar rats fed standard diet (3.95 kcal/g) or HFD (6.3 kcal/g) for 8 wk were assigned into control diet-saline, control diet-LPS, HFD-saline, and HFD-LPS groups. LPS reduced feeding in the control diet but not HFD. This group showed no p-STAT3 expression in the paraventricular nucleus (PVN) and ventromedial hypothalamic nucleus (VMH), but sustained, though lower than control, p-STAT3 in the nucleus of the solitary tract (NTS) and raphe pallidus (RPa). LPS decreased body weight in HFD rats and increased Fos expression in the NTS. LPS increased body temperature, oxygen consumption, and energy expenditure in both control diet and HFD rats, and this response was more pronounced in HFD-LPS group. Brown adipose tissue (BAT) thermogenesis and increased energy expenditure seem to contribute to body weight loss in HFD-LPS. This response might be related with increased brain stem activation. In conclusion, LPS activates STAT3-mediated pathway in the hypothalamus and brain stem, leading to hypophagia, however, LPS effects on food intake, but not body weight loss, are abolished by leptin resistance induced by HFD. The preserved STAT3 phosphorylation in the brain stem suggests that unresponsiveness to LPS on STAT3 activation under HFD might be selective to the hypothalamus. PMID:24226027

  10. Peroxisome proliferator activated receptor gamma is not necessary for the development of LPS-induced tolerance in macrophages.

    PubMed

    Zingarelli, Basilia; Fan, Hongkuan; Ashton, Sarah; Piraino, Giovanna; Mangeshkar, Prajakta; Cook, James A

    2008-05-01

    Peroxisome proliferator activated receptor-gamma (PPARgamma) has been reported to exert anti-inflammatory properties in endotoxic shock and sepsis. One phenomenon that alters the inflammatory response to endotoxin [lipopolysaccharide (LPS)] is endotoxin tolerance, which is caused by previous exposure to endotoxin. Here, we investigate whether changes in endogenous PPARgamma function regulate this phenomenon using three different models of LPS-induced tolerance in macrophages. In a first in vitro model, previous LPS exposure of murine J774.2 macrophages suppressed tumour necrosis factor-alpha (TNF-alpha) release in response to subsequent LPS challenge. Treatment of J774.2 cells with the PPARgamma inhibitor GW9662 did not alter tolerance induction because these cells were still hyporesponsive to the secondary LPS challenge. In a second ex vivo model, primary rat peritoneal macrophages from LPS-primed rats exhibited suppression of thromboxane B2 and TNF-alpha production, while maintaining nitrite production in response to in vitro LPS challenge. Pretreatment of rats with the PPARgamma inhibitor GW9662 in vivo failed to alter the tolerant phenotype of these primary macrophages. In a third ex vivo model, primary peritoneal macrophages with conditional deletion of PPARgamma were harvested from LPS-primed Cre-lox mice (Cre+/+ PPARgamma-/-) and exhibited significant suppression of TNF-alpha production in response to in vitro LPS challenge. Furthermore, both LPS-primed PPARgamma-deficient Cre+/+ PPARgamma-/- mice and wild-type Cre-/- PPARgamma+/+ mice exhibited reduced plasma TNF-alpha levels in response to a high dose of LPS in vivo. These data demonstrate that PPARgamma does not play a role in the LPS-induced tolerant phenotype in macrophages. PMID:18028370

  11. Lipopolysaccharide does not affect acoustic startle reflex in mice.

    PubMed

    Juszczak, Grzegorz R; Blaszczyk, Janusz; Sadowski, Bogdan; Sliwa, Adam T; Wolak, Patrycja; Tymosiak-Zielinska, Agnieszka; Lisowski, Pawel; Swiergiel, Artur H

    2008-01-01

    Bacterial endotoxin (lipopolysaccharide; LPS) evokes in rodents an adaptive sickness behavior. It also produces changes in stress hormones secretion and activity of brain serotonergic and noradrenergic systems that have been implicated in stress responses, fear, and anxiety. Acoustic startle reflex (ASR) is regarded as a protective behavioral response that is enhanced in threatening situations or following an aversive event, and it can be modulated by physiological and emotional state of an animal. Effects of intraperitoneal injections of LPS on ASR, prepulse inhibition (PPI), locomotor activity in open field, and blood plasma corticosterone concentration were studied in lines of mice that display high (HA line) or low (LA line) swim stress-induced analgesia and also differ in emotional behaviors, including the magnitude of ASR. In both lines LPS produced robust sickness behavior, as evidenced by a decrease in locomotion and body weight, and an increase in corticosterone concentration. However, in neither line LPS injections affected responses to acoustic stimuli as assessed by the ASR and PPI magnitudes. The findings suggest that in sickness behavior induced by LPS the protective responses to salient environmental stimuli are not impaired. The significance of this finding for the concept of sickness behavior is discussed. PMID:17651939

  12. Immobilization and molecular interactions between bacteriophage and lipopolysaccharide bilayers.

    PubMed

    Handa, Hitesh; Gurczynski, Stephen; Jackson, Matthew P; Mao, Guangzhao

    2010-07-20

    The paper describes immobilization methods of bacteriophage P22 and tailspike gp9 proteins isolated from P22 on atomic force microscope (AFM) probes. The paper also reports single molecule force spectroscopy (SMFS) using AFM of the immobilized P22 (or gp9) interactions with substrate-supported O-antigenic lipopolysaccharides (LPS) bilayers. LPS covers the outer membrane of gram-negative bacteria, such as Salmonella typhimurium. Evidence from AFM imaging and SMFS shows that immobilized P22 (or gp9) are capable of strong and multivalent binding to supported LPS. The most common rupture forces between P22 and LPS were identified to be 72, 130, 206, and 279 pN at force loading rate of 12,000 pN/s. The quantized unbinding force was found to decrease with decreasing force loading rate as predicted by the Bell model. By fitting the force data with the Bell model, an energy barrier of 55 kJ/mol was obtained. Evidence is also provided that demonstrates the resilience of phage to pH and temperature fluctuation as well as dehydration/rehydration cycles. The biospecific interactions between P22 and the LPS are relevant to cell infection, inflammation, cancer progression and metastasis, food safety, pharmaceuticals, and biosensor development. PMID:20481467

  13. Genomic and Proteomic Studies on Plesiomonas shigelloides Lipopolysaccharide Core Biosynthesis

    PubMed Central

    Aquilini, Eleonora; Merino, Susana; Regué, Miguel

    2014-01-01

    We report here the identification of waa clusters with the genes required for the biosynthesis of the core lipopolysaccharides (LPS) of two Plesiomonas shigelloides strains. Both P. shigelloides waa clusters shared all of the genes besides the ones flanking waaL. In both strains, all of the genes were found in the waa gene cluster, although one common core biosynthetic gene (wapG) was found in a different chromosome location outside the cluster. Since P. shigelloides and Klebsiella pneumoniae share a core LPS carbohydrate backbone extending up at least to the second outer-core residue, the functions of the common P. shigelloides genes were elucidated by genetic complementation studies using well-defined K. pneumoniae mutants. The function of strain-specific inner- or outer-core genes was identified by using as a surrogate acceptor LPS from three well-defined K. pneumoniae core LPS mutants. Using this strategy, we were able to assign a proteomic function to all of the P. shigelloides waa genes identified in the two strains encoding six new glycosyltransferases (WapA, -B, -C, -D, -F, and -G). P. shigelloides demonstrated an important variety of core LPS structures, despite being a single species of the genus, as well as high homologous recombination in housekeeping genes. PMID:24244003

  14. Lipopolysaccharide Pretreatment Protects from Renal Ischemia/Reperfusion Injury

    PubMed Central

    Heemann, Uwe; Szabo, Attila; Hamar, Peter; Müller, Veronika; Witzke, Oliver; Lutz, Jens; Philipp, Thomas

    2000-01-01

    In vivo administration of low doses of lipopolysaccharide (LPS) to rodents can protect these animals from subsequently administrated, usually lethal doses of endotoxin or LPS. In this study we tested the effects of LPS pretreatment on ischemia/reperfusion injury in the kidney. Male C57/B1 mice were pretreated with different doses of LPS or phosphate-buffered saline on days −4 and −3. The right kidney was removed, and the vessels of the left kidney were clamped for 30 or 45 minutes on day 0. Creatinine levels and survival of animals were monitored. To test the involvement of cytokines, additional animals were harvested before (“time 0”) and 15 minutes, 1, 2, 8, and 16 hours after reperfusion for histology, immunohistochemistry, terminal deoxynucleotidyltransferase-mediated UTP end-labeling assay, and reverse transcriptase-polymerase chain reaction analysis (including tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, inducible nitric oxide synthase (iNOS), and interferon (IFN)-γ messenger RNA (mRNA)). In controls, renal ischemia of 30 minutes was nonlethal, whereas 73% of the animals died within 48 ± 18 hours, after 45 minutes of ischemia. All different doses of LPS protected the animals from lethal renal ischemia/reperfusion injury. Starting at similar levels, serum creatinine increased significantly in controls but not in LPS-pretreated animals over time. As early as 2 hours after reperfusion, tubular cell damage was significantly more pronounced in controls than in LPS-treated mice. In controls, tubules deteriorated progressively until 8 hours of reperfusion. At this time, more than 50% of tubular cells were destroyed. This destruction was accompanied by a pronounced leukocytic infiltration, predominantly by macrophages. In contrast, LPS pretreatment prevented the destruction of kidney tissue and infiltration by leukocytes. The terminal deoxynucleotidyltransferase-mediated UTP end-labeling assay revealed significantly more apoptotic cells in

  15. Isolation of monoclonal antibodies reacting with the core component of lipopolysaccharide from Rhizobium leguminosarum strain 3841 and mutant derivatives.

    PubMed Central

    Lucas, M M; Peart, J L; Brewin, N J; Kannenberg, E L

    1996-01-01

    Monoclonal antibodies reacting with the core oligosaccharide or lipid A component of Rhizobium lipopolysaccharide (LPS) could be useful for the elucidation of the structure and biosynthesis of this group of macromolecules. Mutant derivatives of Rhizobium leguminosarum 3841 with LPS structures lacking the major O-antigen moiety were used as immunogens, and eight antibodies were selected for further study. All the antibodies reacted with the fast-migrating species known as LPS-2 following gel electrophoresis of Rhizobium cell extracts. For four of these antibodies, reactivity with affinity-purified LPS was lost after mild acid hydrolysis, indicating that they probably recognized the core oligosaccharide component. The four other antibodies still reacted with acid-treated LPS and may recognize the lipid A moiety, which is stable to mild acid hydrolysis. The pattern of antibody staining after gel electrophoresis revealed differences in LPS-2 epitope structure between each of the mutants and the wild type. Furthermore, for each of the mutants the antibodies crossreacted with a minor band that migrated more slowly than LPS-2; we have termed this more slowly migrating form LPS-3. The majority of the antibodies also reacted with LPS from strain CE109, a derivative of Rhizobium etli CE3, confirming that the LPS core antigens can be relatively conserved between strains of different Rhizobium species. One of the antibodies isolated in this study (JIM 32) was unusual because it appeared to react with all forms of LPS from strain 3841 (namely, LPS-1, LPS-2, and LPS-3). Furthermore, JIM 32 reacted positively with the LPS from many strains of Rhizobium tested (excluding the Rhizobium meliloti subgroup). JIM 32 did not react with representative strains from Bradyrhizobium, Azorhizobium or other related bacterial species. PMID:8631658

  16. Febuxostat protects rats against lipopolysaccharide-induced lung inflammation in a dose-dependent manner.

    PubMed

    Fahmi, Alaa N A; Shehatou, George S G; Shebl, Abdelhadi M; Salem, Hatem A

    2016-03-01

    The aim of the present work was to investigate possible protective effects of febuxostat, a highly potent xanthine oxidase inhibitor, against acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rats. Male Sprague Dawley rats were randomly divided into six groups, as follows: (i) vehicle control group; (ii) and (iii) febuxostat 10 and febuxostat 15 groups, drug-treated controls; (iv) LPS group, receiving an intraperitoneal injection of LPS (7.5 mg/kg); (v) and (vi) febuxostat 10-LPS and febuxostat 15-LPS groups, receiving oral treatment of febuxostat (10 and 15 mg/kg/day, respectively) for 7 days before LPS. After 18 h administration of LPS, blood was collected for C-reactive protein (CRP) measurement. Bronchoalveolar lavage fluid (BALF) was examined for leukocyte infiltration, lactate dehydrogenase (LDH) activity, protein content, and total nitrate/nitrite. Lung weight gain was determined, and lung tissue homogenate was prepared and evaluated for oxidative stress. Tumor necrosis factor-α (TNF-α) was assessed in BALF and lung homogenate. Moreover, histological changes of lung tissues were evaluated. LPS elicited lung injury characterized by increased lung water content (by 1.2 fold), leukocyte infiltration (by 13 fold), inflammation and oxidative stress (indicated by increased malondialdehyde (MDA), by 3.4 fold), and reduced superoxide dismutase (SOD) activity (by 34 %). Febuxostat dose-dependently decreased LPS-induced lung edema and elevations in BALF protein content, infiltration of leukocytes, and LDH activity. Moreover, the elevated levels of TNF-α in BALF and lung tissue of LPS-treated rats were attenuated by febuxostat pretreatment. Febuxostat also displayed a potent antioxidant activity by decreasing lung tissue levels of MDA and enhancing SOD activity. Histological analysis of lung tissue further demonstrated that febuxostat dose-dependently reversed LPS-induced histopathological changes. These findings demonstrate a significant dose

  17. Outer Membrane Remodeling: The Structural Dynamics and Electrostatics of Rough Lipopolysaccharide Chemotypes.

    PubMed

    Dias, Roberta P; da Hora, Gabriel C A; Ramstedt, Madeleine; Soares, Thereza A

    2014-06-10

    Lipopolysaccharides (LPS) are the primary constituent of the outer membrane of Gram-negative bacteria such as Pseudomonas aeruginosa. Gram-negative bacteria can synthesize modified forms of LPS in response to environmental stimuli or due to genetic mutations, a process known as outer membrane remodeling. Chemical modifications of the LPS modulate the integrity and antibiotic susceptibility of bacterial outer membranes. It also governs microbial adhesion to tissues and artificial material surfaces. We have extended a previous model of the rough LPS to include four novel chemotypes rmlC, galU, LPS Re, and Lipid-A. Atomistic molecular dynamics (MD) simulations were performed for outer membrane models constituted of each LPS chemotypes and 1,2-dipalmitoyl-3-phosphatidylethanolamine. It is shown that the decrease in the LPS polysaccharide chain length leads to a significant increase in the diffusion coefficients for the Ca(2+) counterions, increase in acyl chain packing (decrease in membrane fluidity), and attenuation of the negative potential across the LPS surface as positive counterions becomes more exposed to the solvent. The electrostatic potential on the LPS surfaces reflects heterogeneous charge distributions with increasingly larger patches of positive and negative potentials as the polysaccharide chain length decreases. Such a pattern originates from the spatial arrangement of charged phosphate-Ca(2+) clusters in the LPS inner-core that becomes exposed in the membrane surface as monosaccharide units are lost in the shortest chemotypes LPS Re and Lipid-A. These MD-derived conformational ensembles reproduce experimental trends and provide atom-level structural information on the rough LPS chemotypes that can help to rationalize antibiotic resistance and bacterial adhesion processes. PMID:26580769

  18. Movement-evoked hyperalgesia induced by lipopolysaccharides is not suppressed by glucocorticoids

    PubMed Central

    Kovács, Katalin J.; Papic, Jonathan C.; Larson, Alice A.

    2008-01-01

    Systemic exposure to lipopolysaccharides (LPS) produces a variety of effects, including movement-evoked hyperalgesia that can be measured using the grip force assay in mice. Because both lethality and enhanced sensitivity to cutaneous pain following exposure to endotoxins have each been attributed to inflammatory mediators, we explored the possibility that LPS-induced movement-evoked hyperalgesia is also sensitive to manipulations of glucocorticoids that regulate these other LPS responses. We found that the hyperalgesic effect of LPS (5 mg/kg s.c.) in mice that were adrenalectomized did not differ from that in control mice that were sham-operated, even though mortality after LPS was potentiated by adrenalectomy. The development of tolerance to the movement-evoked hyperalgesic effect of LPS also did not differ between adrenalectomized and sham-operated control mice. In addition, mifepristone (25 mg/kg s.c.), a glucocorticoid antagonist, did not attenuate the hyperalgesic effect of LPS (2 mg/kg s.c.), yet this dose of mifepristone was sufficient to enhance the incidence of lethality induced by LPS. Enhancement of glucocorticoid activity by two injections of dexamethasone (1 mg/kg s.c.) had no effect on the degree of hyperalgesia in mice injected with LPS (5 mg/kg s.c.), yet this dose of dexamethasone was sufficient to attenuate the incidence of mortality induced by LPS in adrenalectomized mice. Finally, morphine (10 mg/kg i.p.) reversed the decrease in grip force caused by LPS (5 mg/kg i.p.), supporting the interpretation that decreases in grip force produced by LPS reflect muscle hyperalgesia that is not sensitive to glucocorticoids. PMID:17686584

  19. Extraction, Purification and Characterization of Lipopolysaccharide from Escherichia coli and Salmonella typhi

    PubMed Central

    Rezania, Simin; Amirmozaffari, Noor; Tabarraei, Bahman; Jeddi-Tehrani, Mahmood; Zarei, Omid; Alizadeh, Reza; Masjedian, Faramarz; Zarnani, Amir Hassan

    2011-01-01

    Lipopolysaccharide (LPS) is an important structural component of the outer cell membrane complex of gram negative microorganisms. Its causative role in gram negative bacteria-induced diseases and broad applications in different kinds of cell stimulation experiments provided a conceptual basis for studies directed at the isolation, purification, and detailed chemical characterization of LPS. The main problem with LPS purification protocols is the contamination of the end product with nucleic acids and proteins in variable proportions which could potentially interfere with downstream applications. In this study, a simple procedure for purification of LPS from Escherichia coli (E.coli) and Salmonella typhi (S.typhi) with high purity and very low contaminating nucleic acids and proteins based on the hot phenol-water extraction protocol has been introduced. The purity of extracted LPS was evaluated by silver and coomassie blue staining of SDS-PAGE gels and HPLC analysis. Limulus Amebocyte Lysate (LAL) coagulation activity and rabbit pyrogen assay were exploited to monitor the functionality of purified LPS. The results showed that DNase and RNase treatment of the sample is essential after the sonication step to eliminate nucleic acid contamination in the LPS fraction. Silver staining demonstrated ladder pattern which is characteristic of LPS. No contaminating protein was found as assessed by coomassie blue staining. HPLC fractionation revealed high degree of purity comparable with commercial LPS. Parenteral administration of purified LPS resulted in substantial increase of rabbits’ body temperature (mean: 1.45°C). LAL coagulation assay confirmed the functional activity of the purified LPS. In conclusion, the protocol presented here could be employed for isolation of LPS with high purity and functional activity. PMID:23407691

  20. Barrier protective effects of piperlonguminine in LPS-induced inflammation in vitro and in vivo.

    PubMed

    Lee, Wonhwa; Yoo, Hayoung; Kim, Jeong Ah; Lee, Sangkyu; Jee, Jun-Goo; Lee, Min Young; Lee, You-Mie; Bae, Jong-Sup

    2013-08-01

    Piperlonguminine (PL), an important component of Piper longum fruits, is well known to possess potent anti-hyperlipidemic, anti-platelet and anti-melanogenesis activities. In this study, we first investigated the possible barrier protective effects of piperlonguminine against proinflammatory responses induced by lipopolysaccharide (LPS) and the associated signaling pathways in vitro and in vivo. The barrier protective activities of PL were determined by measuring permeability, monocytes adhesion and migration, and activation of proinflammatory proteins in LPS-activated human umbilical vein endothelial cells (HUVECs) and in mice. We found that PL inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of monocytes to human endothelial cells. PL also suppressed LPS-induced hyperpermeability and leukocytes migration in vivo. Further studies revealed that PL suppressed the production of tumor necrosis factor-α (TNF-α) or Interleukin (IL)-6 and activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, treatment with PL resulted in reduced LPS-induced septic mortality. Collectively, these results suggest that PL protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases. PMID:23619565

  1. Exogenous rhTRX reduces lipid accumulation under LPS-induced inflammation

    PubMed Central

    Han, Gi-Yeon; Lee, Eun-Kyung; Park, Hey-won; Kim, Hyun-Jung; Kim, Chan-Wha

    2014-01-01

    Redox-regulating molecule, recombinant human thioredoxin (rhTRX) which shows anti-inflammatory, and anti-oxidative effects against lipopolysaccharide (LPS)-stimulated inflammation and regulate protein expression levels. LPS-induced reactive oxygen intermediates (ROI) and NO production were inhibited by exogenous rhTRX. We identified up/downregulated intracellular proteins under the LPS-treated condition in exogenous rhTRX-treated A375 cells compared with non-LPS-treated cells via 2-DE proteomic analysis. Also, we quantitatively measured cytokines of in vivo mouse inflammation models using cytometry bead array. Exogenous rhTRX inhibited LPS-stimulated production of ROI and NO levels. TIP47 and ATP synthase may influence the inflammation-related lipid accumulation by affecting lipid metabolism. The modulation of skin redox environments during inflammation is most likely to prevent alterations in lipid metabolism through upregulation of TIP47 and ATP synthase and downregulation of inflammatory cytokines. Our results demonstrate that exogenous rhTRX has anti-inflammatory properties and intracellular regulatory activity in vivo and in vitro. Monitoring of LPS-stimulated pro-inflammatory conditions treated with rhTRX in A375 cells could be useful for diagnosis and follow-up of inflammation reduction related with candidate proteins. These results have a therapeutic role in skin inflammation therapy. PMID:24406320

  2. Dexamethasone and betamethasone protect against LPS-induced brain damage in the neonatal rats

    PubMed Central

    Pang, Yi; Fan, Lir-Wan; Zheng, Baoying; Campbell, Leigh R.; Cai, Zhengwei; Rhodes, Philip G.

    2013-01-01

    The aim of this study is to test whether dexamethasone (Dex) and betamethasone (Beta), two of the most commonly used corticosteroids, protect against lipopolysaccharide (LPS)-induced white matter damage and neurobehavioral dysfunction. LPS or sterile saline was injected into the brain white matter of rat pups at postnatal day 5 (P5) and Dex or Beta was given intraperitoneally to the rat pups 1 h before the LPS microinjection. Brain inflammatory response, brain damage, and myelination were examined at P6, P8 and P14. Neurobehavioral tests were performed from P3 through P22. Our results demonstrate that Dex and Beta markedly diminish the LPS-induced brain inflammatory response, restore myelin basic protein (MBP) expression and alleviate lateral ventricle dilation. Both corticosteroids demonstrate significant protection against most of LPS-induced behavioral deficits, including those in rearing, vibrissa-elicited forelimb-placing, beam walking, learning and elevated plus-maze test. Notably, only Beta improved the locomotion and stereotype dysfunction. In contrast to their beneficial effects, neither drug prevented LPS-induced delay in body weight gain from P6 through P21. Our study suggests that if their adverse effects are minimized, corticosteroids may be the potential candidate drugs to prevent brain damage in premature infants. PMID:22314662

  3. Bacterial Outer Membrane Vesicles Mediate Cytosolic Localization of LPS and Caspase-11 Activation.

    PubMed

    Vanaja, Sivapriya Kailasan; Russo, Ashley J; Behl, Bharat; Banerjee, Ishita; Yankova, Maya; Deshmukh, Sachin D; Rathinam, Vijay A K

    2016-05-19

    Sensing of lipopolysaccharide (LPS) in the cytosol triggers caspase-11 activation and is central to host defense against Gram-negative bacterial infections and to the pathogenesis of sepsis. Most Gram-negative bacteria that activate caspase-11, however, are not cytosolic, and the mechanism by which LPS from these bacteria gains access to caspase-11 in the cytosol remains elusive. Here, we identify outer membrane vesicles (OMVs) produced by Gram-negative bacteria as a vehicle that delivers LPS into the cytosol triggering caspase-11-dependent effector responses in vitro and in vivo. OMVs are internalized via endocytosis, and LPS is released into the cytosol from early endosomes. The use of hypovesiculating bacterial mutants, compromised in their ability to generate OMVs, reveals the importance of OMVs in mediating the cytosolic localization of LPS. Collectively, these findings demonstrate a critical role for OMVs in enabling the cytosolic entry of LPS and, consequently, caspase-11 activation during Gram-negative bacterial infections. PMID:27156449

  4. Effect of anti-dementia drugs on LPS induced neuroinflammation in mice.

    PubMed

    Tyagi, Ethika; Agrawal, Rahul; Nath, Chandishwar; Shukla, Rakesh

    2007-05-01

    Inflammation has been recently implicated in pathogenesis of dementia disorders. Effect of anti-dementia (Acetylcholinesterase inhibitor) drugs tacrine, rivastigmine and donepezil were studied on neuroinflammation induced by intraperitoneal administration of lipopolysaccharide (LPS) in mice. Interleukin-2 (IL-2) and isoforms of acetylcholinesterase (AChE) were estimated in different brain areas as marker for neuroinflammation and cholinergic activity respectively. LPS significantly increased the level of IL-2 in all the brain areas while enhancement of AChE activity varied in brain areas. It was found that administration of tacrine, rivastigmine and donepezil in mice significantly attenuated the LPS induced increased levels of IL-2 along with the significant reduction of AChE activity predominantly in salt soluble (SS) fraction as compared to the detergent soluble (DS) fraction in a dose dependent manner. In vitro effect of LPS was also studied in different brain areas. LPS significantly increased the AChE activity in SS fractions but the significant increase was not found in DS fractions. The present study indicate that cholinesterase inhibitor anti-dementia drugs are effective against LPS induced neuroinflammation that may be linked to enhanced cholinergic activity. PMID:17395211

  5. Ulinastatin attenuates pulmonary endothelial glycocalyx damage and inhibits endothelial heparanase activity in LPS-induced ARDS.

    PubMed

    Wang, Lipeng; Huang, Xiao; Kong, Guiqing; Xu, Haixiao; Li, Jiankui; Hao, Dong; Wang, Tao; Han, Shasha; Han, Chunlei; Sun, Yeying; Liu, Xiangyong; Wang, Xiaozhi

    2016-09-16

    Acute respiratory distress syndrome (ARDS) is a syndrome of acute respiratory failure characterized by major pathologic mechanisms of increased microvascular permeability and inflammation. The glycocalyx lines on the endothelial surface, which determines the vascular permeability, and heparanase play pivotal roles in the degradation of heparan sulfate (HS). HS is the major component of the glycocalyx. The aim of this study is to examine the effects of Ulinastatin (UTI) on vascular permeability and pulmonary endothelial glycocalyx dysfunction induced by lipopolysaccharide (LPS). In our study, C57BL/6 mice and human umbilical vein endothelial cells were stimulated with LPS to induce injury models. After 6 h of LPS stimulation, pulmonary pathological changes, pulmonary edema, and vascular permeability were notably attenuated by UTI. UTI inhibited LPS-induced endothelial glycocalyx destruction and significantly decreased the production of HS as determined by ELISA and immunofluorescence. UTI also reduced the active form of heparanase (50 kDa) expression and heparanase activity. Moreover, lysosome pH was investigated because heparanase (65 kDa) can be reduced easily in its active form at 50 kDa in a low pH environment within lysosome. Results showed that UTI could inhibit LPS-induced pH elevation in lysosome. In conclusion, UTI protects pulmonary endothelial glycocalyx integrity and inhibits heparanase activity during LPS-induced ARDS. PMID:27498004

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

    PubMed

    Yu, Lingling; Zhao, Yingmin; Gu, Xin; Wang, Jijun; Pang, Lei; Zhang, Yanqing; Li, Yaoyao; Jia, Xiaoqin; Wang, Xin; Gu, Jian; Yu, Duonan

    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. PMID:26968634

  7. Heterogeneity of lipopolysaccharides from Pseudomonas aeruginosa: analysis of lipopolysaccharide chain length.

    PubMed Central

    Rivera, M; Bryan, L E; Hancock, R E; McGroarty, E J

    1988-01-01

    Lipopolysaccharide (LPS) from smooth strains of Pseudomonas aeruginosa 503, PAZ1, PAO1715, PAO1716, and Z61 was fractionated by gel filtration chromatography. LPS samples from the first four strains, all PAO1 derivatives, separated into three major size populations, whereas LPS from strain Z61, a Pac K799/WT mutant strain, separated into two size populations. When column fractions were applied to sodium dodecyl sulfate-polyacrylamide gels in their order of elution, molecules of decreasing size were resolved, and the ladder of molecules with different-length O antigens formed a diagonal across the gel. The LPS from the PAO1 derivatives contained two distinct sets of bands, distinguished on the gels as two sets of diagonals. The set of bands with the faster mobility, the B bands, was found in column fractions comprising the three major amino sugar-containing peaks. In the sample from strain 503, a fourth minor peak which contained B bands was resolved. The slower-moving set of bands, the A bands, were recovered in a minor peak. LPS from strain Z61 contained only one set of bands, with the higher-molecular-weight molecules eluting from the column in a volume similar to that of the B bands of the PAO1 strains. Analysis of the fractions of LPS from all strains indicated that less than 8% of the LPS molecules had a long, attached O antigen. Analysis of the peak that contained mainly A bands indicated a lack of reactive amino sugar and phosphate, although heptose and 2-keto-3-deoxyoctulosonic acid were detected. Reaction of isolated fractions with monoclonal antibody specific for the PAO1 O-antigen side chain indicated that only the B bands from the PAO1 strains were antigenically reactive. The bands from strain Z61 showed no reactivity. The data suggest that the A and B bands from the PAO1 strains are antigenically distinct. We propose that PAO1 strains synthesize two types of molecules that are antigenically different. Images PMID:3123455

  8. Altered T Lymphocyte Proliferation upon Lipopolysaccharide Challenge Ex Vivo

    PubMed Central

    Poujol, Fanny; Monneret, Guillaume; Pachot, Alexandre; Textoris, Julien; Venet, Fabienne

    2015-01-01

    Context Sepsis is characterized by the development of adaptive immune cell alterations, which intensity and duration are associated with increased risk of health-care associated infections and mortality. However, pathophysiological mechanisms leading to such lymphocyte dysfunctions are not completely understood, although both intrinsic lymphocyte alterations and antigen-presenting cells (APCs) dysfunctions are most likely involved. Study The aim of the current study was to evaluate whether lipopolysaccharide (LPS, mimicking initial Gram negative bacterial challenge) could directly impact lymphocyte function after sepsis. Therefore, we explored ex-vivo the effect of LPS priming on human T lymphocyte proliferation induced by different stimuli. Results We showed that LPS priming of PBMCs reduced T cell proliferative response and altered IFNγ secretion after stimulation with OKT3 but not with phytohaemagglutinin or anti-CD2/CD3/CD28-coated beads stimulations. Interestingly only LPS priming of monocytes led to decreased T cell proliferative response as opposed to LPS priming of lymphocytes. Importantly, LPS priming was associated with reduced expression of HLA-DR, CD86 and CD64 on monocytes but not with the modification of CD3, CTLA4, PD-1 and CD28 expressions on lymphocytes. Finally, IFNγ stimulation restored monocytes accessory functions and T cell proliferative response to OKT3. Conclusion We conclude that LPS priming does not directly impact lymphocyte functions but reduces APC’s capacity to activate T cells. This recapitulates ex vivo indirect mechanisms participating in sepsis-induced lymphocyte alterations and suggests that monocyte-targeting immunoadjuvant therapies in sepsis may also help to improve adaptive immune dysfunctions. Direct mechanisms impacting lymphocytes being also at play during sepsis, the respective parts of direct versus indirect sepsis-induced lymphocyte alterations remain to be evaluated in clinic. PMID:26642057

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

    PubMed

    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. PMID:24309634

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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. Results 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. Conclusions 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. PMID:24886300

  11. Comparison of the effect of recombinant bovine wild and mutant lipopolysaccharide-binding protein in lipopolysaccharide-challenged bovine mammary epithelial cells.

    PubMed

    Li, Xiaojuan; Li, Lian; Sun, Yu; Wu, Jie; Wang, Genlin

    2016-05-01

    Lipopolysaccharide (LPS)-binding protein (LBP) plays a crucial role in the recognition of bacterial components, such as LPS that causes an immune response. The aim of this study was to compare the different effects of recombinant bovine wild LBP and mutant LBP (67 Ala → Thr) on the LPS-induced inflammatory response of bovine mammary epithelial cells (BMECs). When BMECs were treated with various concentrations of recombinant bovine lipopolysaccharide-binding protein (RBLBP) (1, 5, 10, and 15 μg/mL) for 12 h, RBLBP of 5 μg/mL increased the apoptosis of BMECs induced by LPS without cytotoxicity, and mutant LBP resulted in a higher cell apoptosis than wild LBP did. By gene-chip microarray and bioinformatics, the data identified 2306 differentially expressed genes that were changed significantly between the LPS-induced inflamed BMECs treated with 5 μg/mL of mutant LBP and the BMECs only treated with 10 μg/mL of LPS (fold change ≥2). Meanwhile, 1585 genes were differently expressed between the inflamed BMECs treated with 5 μg/mL of wild LBP and 10 μg/mL of LPS-treated BMECs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that these differentially expressed genes were involved in different pathways that regulate the inflammation response. It predicted that carriers of this mutation increase the risk for a more severe inflammatory response. Our study provides an overview of the gene expression profile between wild LBP and mutant LBP on the LPS-induced inflammatory response of BMECs, which will lead to further understanding of the potential effects of LBP mutations on bovine mammary glands. PMID:26813383

  12. Effects of Lipopolysaccharide and Progesterone Exposures on Embryonic Cerebral Cortex Development in Mice.

    PubMed

    Tronnes, Ashlie A; Koschnitzky, Jenna; Daza, Ray; Hitti, Jane; Ramirez, Jan Marino; Hevner, Robert

    2016-06-01

    Our objective was to determine if progesterone pretreatment could ameliorate the detrimental effects of lipopolysaccharide (LPS)-induced inflammation on cortical neurogenesis. Timed pregnant mouse dams (n = 8) were given intraperitoneal injections of progesterone (42 mg/kg) or vehicle on embryonic day 17.5. Two hours later, mice were given intraperitoneal LPS (140 μg/kg) or vehicle. Mice were sacrificed 16 hours later on embryonic day 18. Two-color immunofluorescence was performed with primary antibodies T-box transcription factor 2 (Tbr2), ionized calcium binding adapter molecule 1 (Iba1), cleaved caspase 3 (CC3), and 5-bromo-2'-deoxyuridine (BrdU). Cells were counted, and statistical analysis was determined using analysis of variance and Tukey-Kramer method. The Tbr2 intermediate neural progenitor cell density decreased after LPS exposure (P = .0022). Pre-exposure to progesterone statistically increased Tbr2 intermediate neural progenitors compared to LPS treatment alone and was similar to controls (P = .0022). After LPS exposure, microglia displayed an activated phenotype, and cell density was increased (P < .001). Cell death rates were low among study groups but was increased in LPS exposure groups compared to progesterone alone (P = .0015). Lipopolysaccharide-induced systemic inflammation reduces prenatal neurogenesis in mice. Pre-exposure with progesterone is associated with increased neurogenesis. Progesterone may protect the preterm brain from defects of neurogenesis induced by inflammation. PMID:26621965

  13. The effectiveness of potent dental adhesives on the viability of LPS challenged human gingival fibroblasts.

    PubMed

    Garner, Angelia D; Tucci, Michelle A; Benghuzzi, Hamed A

    2014-01-01

    Dental adhesives are necessary for the retention of specific dental restorations utilized to repair the anatomy of the tooth after dental decay is removed. Adhesives come into contact with healthy and diseased periodontal tissues. Porphyromonas gingivalis is a gram negative bacterial pathogen, and lipopolysaccharide (LPS-PG) is an endotoxin found in gingival connective tissues of patients who suffer from periodontal disease. The presence of the endotoxin causes inflammation. This study aims to evaluate the effectiveness of potent dental adhesives when human gingival fibroblasts are challenged with LPS-PG. The fibroblasts were exposed to the dental adhesives polymethly methacrylate (PMMA), OptiBond®, and Prime & Bond® which were purchased from Patterson Dental, a national dental materials supplier. The human gingival fibroblasts (HGF-1, ATCC® CRL-2014™) were purchased from American Type Culture Collection (ATCC). The porphyromonas gingival lipopolysaccharide (LPS-PG) was purchased from Fisher Scientific (Pittsburg, PA). No significant differences in metabolic behavior was detected among the groups (p<0.132). While the glutathione assay determined that there was not any significant increase in oxidative stress levels; the lactate dehydrogenase assay identified significant cellular damage in the group exposed to combinations of the Prime & Bond® adhesives and LPS-PG at 48 hour intervals (p<0.003). No significant changes were noted in cellular morphology at any phases, and all cells demonstrated typical fibroblast spindle shape. PMID:25405402

  14. Phylogenomic analysis supports the ancestral presence of LPS-outer membranes in the Firmicutes.

    PubMed

    Antunes, Luisa Cs; Poppleton, Daniel; Klingl, Andreas; Criscuolo, Alexis; Dupuy, Bruno; Brochier-Armanet, Céline; Beloin, Christophe; Gribaldo, Simonetta

    2016-01-01

    One of the major unanswered questions in evolutionary biology is when and how the transition between diderm (two membranes) and monoderm (one membrane) cell envelopes occurred in Bacteria. The Negativicutes and the Halanaerobiales belong to the classically monoderm Firmicutes, but possess outer membranes with lipopolysaccharide (LPS-OM). Here, we show that they form two phylogenetically distinct lineages, each close to different monoderm relatives. In contrast, their core LPS biosynthesis enzymes were inherited vertically, as in the majority of bacterial phyla. Finally, annotation of key OM systems in the Halanaerobiales and the Negativicutes shows a puzzling combination of monoderm and diderm features. Together, these results support the hypothesis that the LPS-OMs of Negativicutes and Halanaerobiales are remnants of an ancient diderm cell envelope that was present in the ancestor of the Firmicutes, and that the monoderm phenotype in this phylum is a derived character that arose multiple times independently through OM loss. PMID:27580370

  15. Selective Exposure of the Fetal Lung and Skin/Amnion (but Not Gastro-Intestinal Tract) to LPS Elicits Acute Systemic Inflammation in Fetal Sheep

    PubMed Central

    Saito, Masatoshi; Newnham, John P.; Cox, Tom; Jobe, Alan H.; Kramer, Boris W.; Kallapur, Suhas G.

    2013-01-01

    Inflammation of the uterine environment (commonly as a result of microbial colonisation of the fetal membranes, amniotic fluid and fetus) is strongly associated with preterm labour and birth. Both preterm birth and fetal inflammation are independently associated with elevated risks of subsequent short- and long-term respiratory, gastro-intestinal and neurological complications. Despite numerous clinical and experimental studies to investigate localised and systemic fetal inflammation following exposure to microbial agonists, there is minimal data to describe which fetal organ(s) drive systemic fetal inflammation. We used lipopolysaccharide (LPS) from E.coli in an instrumented ovine model of fetal inflammation and conducted a series of experiments to assess the systemic pro-inflammatory capacity of the three major fetal surfaces exposed to inflammatory mediators in pregnancy (the lung, gastro-intestinal tract and skin/amnion). Exposure of the fetal lung and fetal skin/amnion (but not gastro-intestinal tract) caused a significant acute systemic inflammatory response characterised by altered leucocytosis, neutrophilia, elevated plasma MCP-1 levels and inflammation of the fetal liver and spleen. These novel findings reveal differential fetal organ responses to pro-inflammatory stimulation and shed light on the pathogenesis of fetal systemic inflammation after exposure to chorioamnionitis. PMID:23691033

  16. Lipopolysaccharide potentiates hyperthermia-induced seizures

    PubMed Central

    Eun, Baik-Lin; Abraham, Jayne; Mlsna, Lauren; Kim, Min Jung; Koh, Sookyong

    2015-01-01

    Background Prolonged febrile seizures (FS) have both acute and long-lasting effects on the developing brain. Because FS are often associated with peripheral infection, we aimed to develop a preclinical model of FS that simulates fever and immune activation in order to facilitate the implementation of targeted therapy after prolonged FS in young children. Methods The innate immune activator lipopolysaccharide (LPS) was administered to postnatal day 14 rat (200 μg/kg) and mouse (100 μg/kg) pups 2–2.5 h prior to hyperthermic seizures (HT) induced by hair dryer or heat lamp. To determine whether simulation of infection enhances neuronal excitability, latency to seizure onset, threshold temperature and total number of seizures were quantified. Behavioral seizures were correlated with electroencephalographic changes in rat pups. Seizure-induced proinflammatory cytokine production was assessed in blood samples at various time points after HT. Seizure-induced microglia activation in the hippocampus was quantified using Cx3cr1GFP/+ mice. Results Lipopolysaccharide priming increased susceptibility of rats and mice to hyperthemic seizures and enhanced seizure-induced proinflammatory cytokine production and microglial activation. Conclusions Peripheral inflammation appears to work synergistically with hyperthermia to potentiate seizures and to exacerbate seizure-induced immune responses. By simulating fever, a regulated increase in body temperature from an immune challenge, we developed a more clinically relevant animal model of prolonged FS. PMID:26357586

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

    PubMed Central

    Kroager, Toke P.; Sanggaard, Kristian W.; Knudsen, Anders D.; Stensballe, Allan; Enghild, Jan J.; Ølholm, Jens; Richelsen, Bjørn; Pedersen, Steen B.

    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 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 adipose tissue

  18. Lipopolysaccharide Inhibits the Channel Activity of the P2X7 Receptor

    PubMed Central

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

    2011-01-01

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

  19. Lipopolysaccharide stimulation improves the odontoblastic differentiation of human dental pulp cells.

    PubMed

    Huang, Yihua; Jiang, Hongwei; Gong, Qimei; Li, Xuyan; Ling, Junqi

    2015-05-01

    Lipopolysaccharide (LPS) is one of the causative agents of pulpitis and previous studies have demonstrated that the LPS stimulation of human aortic valve interstitial cells induces inflammatory mediators and the gene expression of osteogenic factors. Therefore, in the present study, it was hypothesized that LPS affects the odontoblastic differentiation of human dental pulp cells (hDPCs). In order to investigate this, an in vitro study using hDPCs was performed. Increased alkaline phosphatase (ALP) activity was observed in the hDPCs treated with LPS, which was more marked when the cells were costimulated with odontogenic induction medium (OM). LPS also appeared to increase the gene expression levels of dentin sialophosphoprotein and dentin matrix protein‑1 and the protein expression level of dental sialoprotein in the hDPCs, particularly in combination with OM. In addition, the size and the number of nodules formed in the hDPCs exposed to OM and LPS were increased compared to those stimulated by OM alone. To determine the role of nuclear factor κB (NF‑κB) during the LPS‑induced odontoblastic differentiation of hDPCs, immunofluorescence was performed. The nuclear translocation of NF‑κB, induced by LPS was confirmed, suggesting its involvement in the LPS‑induced increase in odontoblastic differentiation of hDPCs. In conclusion, there may be an association between LPS stimulation, with or without OM, and odontoblastic differentiation. PMID:25528991

  20. Lipopolysaccharide inhibits the channel activity of the P2X7 receptor.

    PubMed

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

    2011-01-01

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

  1. LIPOPOLYSACCHARIDE ATTENUATES PHRENIC LONG-TERM FACILITATION FOLLOWING ACUTE INTERMITTENT HYPOXIA

    PubMed Central

    Vinit, Stéphane; Windelborn, James A.; Mitchell, Gordon S.

    2011-01-01

    Lipopolysaccharide (LPS) induces inflammatory responses, including microglial activation in the central nervous system. Since LPS impairs certain forms of hippocampal and spinal neuroplasticity, we hypothesized that LPS would impair phrenic long-term facilitation (pLTF) following acute intermittent hypoxia (AIH) in outbred Sprague-Dawley (SD) and inbred Lewis (L) rats.. Approximately three hours following a single LPS injection (i.p.), the phrenic response during hypoxic episodes is reduced in both rat strains versus vehicle treated, control rats (SD: 84±7% vs. 128±14% baseline for control, p<0.05; L: 62±10% vs. 90±9% baseline for control, p<0.05). At 60 min post-AIH, pLTF is also diminished by LPS in both strains: (SD: 22±5% vs. 73.5±14% baseline for control, p<0.05; L: 18±15% vs. 56±8% baseline for control, p<0.05). LPS alone does not affect phrenic burst frequency in either rat strain, suggesting that acute LPS injection has minimal effect on brainstem respiratory rhythm generation. Thus, systemic LPS injections and (presumptive) inflammation impair pLTF, a form of spinal neuroplasticity in respiratory motor control. These results suggest that ongoing infection or inflammation must be carefully considered in studies of respiratory plasticity, or during attempts to harness spinal plasticity as a therapeutic tool in the treatment of respiratory insufficiency, such as spinal cord injury. PMID:21334467

  2. Differential Responses Between Monocytes and Monocyte-Derived Macrophages for Lipopolysaccharide Stimulation of Calves

    PubMed Central

    Guo, Yijie; Zhao, Guoqi; Tanaka, Sachi; Yamaguchi, Takahiro

    2009-01-01

    In this experiment Toll-like receptor expression pattern in monocytes and monocyte-derived macrophages by lipopolysaccharide (LPS) stimulation was examined. Jugular venous blood was collected from four Japanese calves, and the peripheral blood mononuclear cells (PBMCs) were isolated. The cells were directly used for collecting monocytes by magnetic cell sorting or cultured for 7 days to collect monocyte-derived macrophages in Repcell. Then we analyzed the mRNA expression pattern of TLRs and cytokines in monocytes and monocyte-derived macrophages after LPS stimulation for 24 h. LPS stimulation of both monocytes and monocyte-derived macrophages resulted in an increase in the levels of mRNA transcripts for TNF-α, IL-6 and IL-8. Moreover, TNF-α and IL-6 mRNA expressions were significantly augmented by LPS stimulation in monocyte-derived macrophages. TLRs mRNA expressions were unchanged after LPS stimulation of monocytes, while TLRs mRNA expressions in monocyte-derived macrophages were complicated. TLR1, 3, 5, 8 and 10 were significantly decreased after LPS stimulation and there were no differences in the mRNA expressions of TLR2, 4, 6 and 7 between the groups of control and LPS stimulation. Besides, no expression of TLR9 was found. As antigen presenting cells, monocytes and monocyte-derived macrophages respond differently to LPS, so they may have different functions in the innate immune system. PMID:19567206

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

    PubMed

    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. PMID:26712364

  4. Interactions between magainin 2 and Salmonella typhimurium outer membranes: Effect of lipopolysaccharide structure

    SciTech Connect

    Rana, F.R.; Macias, E.A.; Sultany, C.M.; Modzrakowski, M.C.; Blazyk, J. )

    1991-06-18

    The role of the outer membrane and lipopolysaccharide (LPS) in the interaction between the small cationic antimicrobial peptide magainin 2 and the Gram-negative cell envelope was studied by FT-IR spectroscopy. Magainin 2 alters the thermotropic properties of the outer membrane-peptidoglycan complexes from wild-type Salmonella typhimurium and a series of LPS mutants which display differential susceptibility to the bactericidal activity of cationic antibiotics. These results are correlated with the LPS phosphorylation pattern and charge (characterized by high-resolution {sup 31}P NMR) and outer membrane lipid composition, and are compared to the bactericidal susceptibility. LPS mutants show a progressive loss of resistance to killing by magainin 2 as the length of the LPS polysaccharide moiety decreases. Disordering of the outer membrane lipid fatty acyl chains by magainin 2, however, depends primarily upon the magnitude of PLS charge rather than the length of the LPS polysaccharide. While disruption of outer membrane structure most likely is not the primary factor leading to cell death, the susceptibility of Gram-negative cells to magainin 2 is associated with factors that facilitate the transport of the peptide across the outer membrane, such as the magnitude and location of LPS charge, and concentration of LPS in the outer membrane, outer membrane molecular architecture, and the presence or absence of the O-antigen side chain.

  5. Protective effect of catalpol on lipopolysaccharide-induced acute lung injury in mice.

    PubMed

    Fu, Kai; Piao, Taikui; Wang, Mingzhi; Zhang, Jian; Jiang, Jiuyang; Wang, Xuefeng; Liu, Hongyu

    2014-12-01

    Catalpol, an iridiod glucoside isolated from Rehmannia glutinosa, has been reported to have anti-inflammatory properties. Although anti-inflammatory activity of catalpol already reported, its involvement in lung protection has not been reported. Thus, we investigated the role of catalpol on lipopolysaccharide (LPS)-induced acute lung injury in this study. Mice acute lung injury model was induced by intranasal instillation of LPS. Catalpol was administrated 1h prior to or after LPS exposure. The severity of pulmonary injury was evaluated 12h after LPS administration. The results showed that catalpol inhibited lung W/D ratio, myeloperoxidase activity of lung samples, the amounts of inflammatory cells and TNF-α, IL-6, IL-4 and IL-1β in BALF induced by LPS. The production of IL-10 in BALF was up-regulated by catalpol. In vitro, catalpol inhibited TNF-α, IL-6, IL-4 and IL-1β production and up-regulated IL-10 expression in LPS-stimulated alveolar macrophages. Moreover, western blot analysis showed that the activation of NF-κB and MAPK signaling pathways was inhibited by catalpol. Furthermore, catalpol was found to inhibit TLR4 expression induced by LPS. In conclusion, catalpol potently protected against LPS-induced ALI. The protective effect may attribute to the inhibition of TLR4-mediated NF-κB and MAPK signaling pathways. PMID:25063711

  6. Interactions between chensinin-1, a natural antimicrobial peptide derived from Rana chensinensis, and lipopolysaccharide.

    PubMed

    Dong, Weibing; Sun, Yue; Shang, Dejing

    2015-12-01

    Lipopolysaccharide (LPS) plays a critical role in the pathogenesis of sepsis caused by gram-negative bacterial infections. Therefore, LPS-neutralizing molecules would have important clinical applications. Chensinin-1, a novel antimicrobial peptide with atypical structural features, was found in the skin secretions of the Chinese brown frog Rana chensinensis. To understand the role of LPS in the bacterial susceptibility to chensinin-1 and to investigate its anti-endotoxin effects, the interactions of chensinin-1 with LPS were investigated in this study using circular dichroism, in situ IR, isothermal titration calorimetry, and zeta potential. This study is the first to use in situ IR spectroscopy to evaluate the secondary structural changes of this peptide. The capacity of chensinin-1 to block the LPS-dependent cytokine secretion of macrophages was also investigated. Our results show that chensinin-1 can form α-helical structures in LPS suspensions. LPS can affect the antimicrobial activity of chensinin-1, and chensinin-1 was able to mitigate the effects of LPS. These data may facilitate the development of antimicrobial peptides with potent antimicrobial and anti-endotoxin activities. PMID:26340228

  7. A mutant Escherichia coli that attaches peptidoglycan to lipopolysaccharide and displays cell wall on its surface

    PubMed Central

    Grabowicz, Marcin; Andres, Dorothee; Lebar, Matthew D; Malojčić, Goran; Kahne, Daniel; Silhavy, Thomas J

    2014-01-01

    The lipopolysaccharide (LPS) forms the surface-exposed leaflet of the outer membrane (OM) of Gram-negative bacteria, an organelle that shields the underlying peptidoglycan (PG) cell wall. Both LPS and PG are essential cell envelope components that are synthesized independently and assembled by dedicated transenvelope multiprotein complexes. We have identified a point-mutation in the gene for O-antigen ligase (WaaL) in Escherichia coli that causes LPS to be modified with PG subunits, intersecting these two pathways. Synthesis of the PG-modified LPS (LPS*) requires ready access to the small PG precursor pool but does not weaken cell wall integrity, challenging models of precursor sequestration at PG assembly machinery. LPS* is efficiently transported to the cell surface without impairing OM function. Because LPS* contains the canonical vancomycin binding site, these surface-exposed molecules confer increased vancomycin-resistance by functioning as molecular decoys that titrate the antibiotic away from its intracellular target. This unexpected LPS glycosylation fuses two potent pathogen-associated molecular patterns (PAMPs). DOI: http://dx.doi.org/10.7554/eLife.05334.001 PMID:25551294

  8. Role of tumor necrosis factor-alpha in lipopolysaccharide-induced pathologic alterations.

    PubMed Central

    Remick, D. G.; Strieter, R. M.; Eskandari, M. K.; Nguyen, D. T.; Genord, M. A.; Raiford, C. L.; Kunkel, S. L.

    1990-01-01

    Tumor necrosis factor-alpha (TNF) has been implicated strongly as a principal mediator in the pathogenesis of septic shock. The authors investigated the in vivo production of TNF in CBA/J and CD-1 mice that had been primed by an intraperitoneal injection of complete Freund's adjuvant followed 2 weeks later by an intraperitoneal injection of lipopolysaccharide (LPS). TNF bioactivity peaked in both the ascites and plasma one hour after challenge, and TNF mRNA expression in the ascites cells peaked 30 minutes after LPS. After the induction of bioactivity, an interstitial pulmonary neutrophilic infiltrate occurred that was quantitated both morphometrically and by a myeloperoxidase (MPO) assay. Peripheral blood neutrophilia and lymphopenia developed after the LPS injection (PMNs: control, 46 +/- 2%; LPS, 65 +/- 3%; Lymphs control, 53 +/- 2%; LPS, 37 +/- 3%). Treatment with dexamethasone (Dex) completely inhibited the pulmonary neutrophilic infiltrate as measured by the (MPO) assay. Because Dex will inhibit the production of several cytokines, anti-TNF antiserum was given to mice at the same time as the LPS challenge to assess specifically the role of TNF in inducing these changes. This antiserum partially blocked the pulmonary neutrophil infiltrate, and completely blocked the peripheral blood changes at one hour after LPS. These data demonstrate that TNF plays an important role in the early pathophysiologic alterations that occur after systemic exposure to LPS. Images Figure 3 Figure 4 Figure 6 Figure 11 PMID:2297050

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

    SciTech Connect

    Islam, Shamima; Hassan, Ferdaus; Tumurkhuu, Gantsetseg; Dagvadorj, Jargalsaikhan; Koide, Naoki; Naiki, Yoshikazu; Mori, Isamu; Yoshida, Tomoaki; Yokochi, Takashi . E-mail: yokochi@aichi-med-u.ac.jp

    2007-08-24

    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)-{alpha} antibody, but not antibodies to macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-{kappa}B ligand (RANKL). TNF-{alpha} might play a critical role in LPS-induced osteoclast formation in RAW 264.7 cells. Inhibitors of NF-{kappa}B and stress activated protein kinase (SAPK/JNK) prevented the LPS-induced osteoclast formation. The detailed mechanism of LPS-induced osteoclast formation is discussed.

  10. Interaction of peptide-bound beads with lipopolysaccharide and lipoproteins.

    PubMed

    Suzuki, Masatsugu M; Matsumoto, Megumi; Omi, Hiroyuki; Kobayashi, Tomomi; Nakamura, Akio; Kishi, Hiroko; Kobayashi, Sei; Takagi, Takashi

    2014-05-01

    We previously reported the generation of lipopolysaccharide (LPS)-binding peptides by phage display and chemical modification. Among them, a dodecapeptide designated Li5-025 (K'YSSSISSIRAC'; K' and C' denote d-lysine and d-cysteine, respectively) showed a high binding affinity for LPS and was resistant to protease digestion (Suzuki et al., 2010). In the current study, Li5-025-bound silica beads, hereafter referred to as P-beads, were generated and found to be devoid of LPS-neutralizing activity. Thus, LPS bound to the P-beads could be directly used in the Limulus amebocyte lysate (LAL) assay. P-beads bound LPS dissolved in solutions of ethanol, pH4, pH10, and 0.5M NaCl and LPS bound to the P-beads was quantitatively assayed. The sensitivity of this assay was observed to be approximately 0.1pg/mL LPS. P-beads bound LPS dissolved in antithrombin III (AT III) solution which is a strong inhibitor of activated factors C and B as well as the clotting enzyme in the LAL assay; the inhibitory effect of AT III was completely reversed upon washing the P-beads with 25% acetonitrile. This was employed as the first step for the detection of free LPS in plasma using the LAL assay. LPS added to human plasma at 0°C followed by application to the P-beads and subsequent washing with 25% acetonitrile resulted in low LPS activity as detected by the LAL assay. However, further washing of the P-beads with 0.1% Triton X100 in 25% acetonitrile resulted in high LPS activity. This is the first instance of quantitative detection of free LPS in plasma using the LAL assay, and the sensitivity of this method was observed to be 1pg/mL of LPS. The proteins eluted in the 0.1% Triton X-100 wash were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Two protein bands of 28kDa and 18kDa were predominantly observed. Mass spectrometry analysis revealed that the 28kDa and 18kDa bands corresponded to apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II), respectively. Apo

  11. The OVLT initiates the fall in arterial pressure evoked by high dose lipopolysaccharide: evidence that dichotomous, dose-related mechanisms mediate endotoxic hypotension.

    PubMed

    Feleder, Carlos; Sertac Yilmaz, M; Peng, Jianya; Göktalay, Gökhan; Millington, William R

    2015-08-15

    This study tested the hypothesis that lipopolysaccharide (LPS) lowers arterial pressure through two different mechanisms depending on the dose. Previously, we found that a low hypotensive dose of LPS (1mg/kg) lowers arterial pressure by activating vagus nerve afferents. Here we report that hypotension evoked by high dose LPS (15mg/kg) can be prevented by injecting lidocaine into the OVLT but not by vagotomy or inactivation of the NTS. The hypotension produced by both LPS doses was correlated with elevated extracellular norepinephrine concentrations in the POA and prevented by blocking alpha-adrenergic receptors. Thus, initiation of endotoxic hypotension is dose-related, mechanistically. PMID:26198924

  12. Expression of Rhizobium leguminosarum CFN42 genes for lipopolysaccharide in strains derived from different R. leguminosarum soil isolates

    SciTech Connect

    Brink, B.A.; Noel, K.D. ); Miller, J.; Carlson, R.W. )

    1990-02-01

    Two mutant derivatives of Rhizobium leguminosarum ANU843 defective in lipopolysaccharide (LPS) were isolated. The LPSs of both mutants lacked O antigen and some sugar residues of the LPS core oligosaccharides. Genetic regions previously cloned from another Rhizobium leguminosarum wild-type isolate, strain CFN42, were used to complement these mutants. One mutant was complemented to give LPS that was apparently identical to the LPS of strain ANU843 in antigenicity, electrophoretic mobility, and sugar composition. The other mutant was complemented by a second CFN42lps genetic region. In this case the resulting LPS contained O-antigen sugars characteristic of donor strain CFN42 and reacted weakly with antiserum against CFN42 cells, but did not react detectably with antiserum against ANU843 cells. Therefore, one of the CFN42 lps genetic regions specifies a function that is conserved between the two R. leguminosarum wild-type isolates, whereas the other region, at least in part, specifies a strain-specific LPS structure. Transfer of these two genetic regions into wild-type strains derived from R. leguminosarum ANU843 and 128C53 gave results consistent with this conclusion. The mutants derived from strain ANU843 elicited incompletely developed clover nodules that exhibited low bacterial populations and very low nitrogenase activity. Both mutants elicited normally developed, nitrogen-fixing clover nodules when they carried CFN42 lps DNA that permitted synthesis of O-antigen-containing LPS, regardless of whether the O antigen was the one originally made by strain ANU843.

  13. Synthetic Antimicrobial Peptides Exhibit Two Different Binding Mechanisms to the Lipopolysaccharides Isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae

    PubMed Central

    Chai, Hanbo; Allen, William E.; Hicks, Rickey P.

    2014-01-01

    Circular dichroism and 1H NMR were used to investigate the interactions of a series of synthetic antimicrobial peptides (AMPs) with lipopolysaccharides (LPS) isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae. Previous CD studies with AMPs containing only three Tic-Oic dipeptide units do not exhibit helical characteristics upon interacting with small unilamellar vesicles (SUVs) consisting of LPS. Increasing the number of Tic-Oic dipeptide units to six resulted in five analogues with CD spectra that exhibited helical characteristics on binding to LPS SUVs. Spectroscopic and in vitro inhibitory data suggest that there are two possible helical conformations resulting from two different AMP-LPS binding mechanisms. Mechanism one involves a helical binding conformation where the AMP binds LPS very strongly and is not efficiently transported across the LPS bilayer resulting in the loss of inhibitory activity. Mechanism two involves a helical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. Mechanism three involves a nonhelical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. PMID:25610647

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

    PubMed Central

    Brancaccio, Mariarita; Coretti, Lorena; Florio, Ermanno; Pezone, Antonio; Calabrò, Viola; Falco, Geppino; Keller, Simona; Lembo, Francesca; Avvedimento, Vittorio Enrico; Chiariotti, Lorenzo

    2016-01-01

    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. PMID:27253528

  15. The tyrosine kinase inhibitor imatinib prevents lung injury and death after intravenous LPS in mice

    PubMed Central

    Stephens, R Scott; Johnston, Laura; Servinsky, Laura; Kim, Bo S; Damarla, Mahendra

    2015-01-01

    Severe sepsis and septic shock are frequent causes of the acute respiratory distress syndrome, and important sources of human mortality. Lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls, plays a major role in the pathogenesis of severe sepsis and septic shock. LPS exposure induces the production of harmful reactive oxygen species, and the resultant oxidant injury has been implicated in the pathogenesis of both severe sepsis and ARDS. We previously showed that the tyrosine kinase inhibitor imatinib increases lung endothelial antioxidant enzymes and protects against pulmonary endothelial antioxidant injury. In the present study, we tested the hypothesis that imatinib would protect against lung injury and systemic inflammation caused by intravenous LPS in an intact mouse model of endotoxemia mimicking early sepsis. We found that intravenous LPS induced a significant increase in the activity of lung xanthine oxidoreductase (XOR), an enzyme which is a major source of reactive oxygen species and implicated in the pathogenesis of acute lung injury. Imatinib had no effect of LPS-induced XOR activity. However, pretreatment of mice with imatinib increased lung catalase activity and decreased intravenous LPS-induced lung oxidant injury as measured by γ-H2AX, a marker of oxidant-induced DNA damage, lung apoptosis, and pulmonary edema. Imatinib also attenuated systemic cytokine expression after intravenous LPS exposure. Finally, imatinib completely prevented mortality in an in vivo, intravenous LPS mouse model of endotoxemia and lung injury. These results support the testing of imatinib as a novel pharmacologic agent in the treatment of Gram-negative sepsis and sepsis-induced ARDS. PMID:26620257

  16. Endothelial cell tetrahydrobiopterin deficiency attenuates LPS-induced vascular dysfunction and hypotension☆

    PubMed Central

    Chuaiphichai, Surawee; Starr, Anna; Nandi, Manasi; Channon, Keith M.; McNeill, Eileen

    2016-01-01

    Overproduction of nitric oxide (NO) is thought to be a key mediator of the vascular dysfunction and severe hypotension in patients with endotoxaemia and septic shock. The contribution of NO produced directly in the vasculature by endothelial cells to the hypotension seen in these conditions, vs. the broader systemic increase in NO, is unclear. To determine the specific role of endothelium derived NO in lipopolysaccharide (LPS)-induced vascular dysfunction we administered LPS to mice deficient in endothelial cell tetrahydrobiopterin (BH4), the essential co-factor for NO production by NOS enzymes. Mice deficient in endothelial BH4 production, through loss of the essential biosynthesis enzyme Gch1 (Gch1fl/flTie2cre mice) received a 24 hour challenge with LPS or saline control. In vivo LPS treatment increased vascular GTP cyclohydrolase and BH4 levels in aortas, lungs and hearts, but this increase was significantly attenuated in Gch1fl/flTie2cre mice, which were also partially protected from the LPS-induced hypotension. In isometric tension studies, in vivo LPS treatment reduced the vasoconstriction response and impaired endothelium-dependent and independent vasodilatations in mesenteric arteries from wild-type mice, but not in Gch1fl/flTie2cre mesenteric arteries. Ex vivo LPS treatment decreased vasoconstriction response to phenylephrine in aortic rings from wild-type and not in Gch1fl/flTie2cre mice, even in the context of significant eNOS and iNOS upregulation. These data provide direct evidence that endothelial cell NO has a significant contribution to LPS-induced vascular dysfunction and hypotension and may provide a novel therapeutic target for the treatment of systemic inflammation and patients with septic shock. PMID:26276526

  17. Enhanced Biofilm Formation by Escherichia coli LPS Mutants Defective in Hep Biosynthesis

    PubMed Central

    Nakao, Ryoma; Ramstedt, Madeleine; Wai, Sun Nyunt; Uhlin, Bernt Eric

    2012-01-01

    Lipopolysaccharide (LPS) is the major component of the surface of Gram-negative bacteria and its polysaccharide portion is situated at the outermost region. We investigated the relationship between the polysaccharide portion of LPS and biofilm formation using a series of Escherichia coli mutants defective in genes earlier shown to affect the LPS sugar compositions. Biofilm formation by a deep rough LPS mutant, the hldE strain, was strongly enhanced in comparison with the parental strain and other LPS mutants. The hldE strain also showed a phenotype of increased auto-aggregation and stronger cell surface hydrophobicity compared to the wild-type. Similar results were obtained with another deep rough LPS mutant, the waaC strain whose LPS showed same molecular mass as that of the hldE strain. Confocal laser scanning microscopy (CLSM) analysis and biofilm formation assay using DNase I revealed that biofilm formation by the hldE strain was dependent on extracellular DNA. Furthermore, a loss of flagella and an increase in amount of outer membrane vesicles in case of the hldE strain were also observed by transmission electron microscopy and atomic force microscopy, respectively. In addition, we demonstrated that a mutation in the hldE locus, which alters the LPS structure, caused changes in both expression and properties of several surface bacterial factors involved in biofilm formation and virulence. We suggest that the implication of these results should be considered in the context of biofilm formation on abiotic surfaces, which is frequently associated with nosocominal infections such as the catheter-associated infections. PMID:23284671

  18. Involvement of mitogen-activated protein kinases and NF{kappa}B in LPS-induced CD40 expression on human monocytic cells

    SciTech Connect

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

    2008-04-15

    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 NF{kappa}B were activated by LPS exposure and involved in LPS-induced CD40 expression. Activation of MAPKs was not responsible for LPS-induced NF{kappa}B 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 NF{kappa}B 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 NF{kappa}B activation, and CD40 expression. Moreover, blockage of MAPK and NF{kappa}B activation inhibited LPS-induced TLR4 expression. In summary, LPS-induced CD40 expression in monocytic cells involves MAPKs and NF{kappa}B.

  19. Protective Effect of SAHA against LPS-induced Liver Damage in Rodents

    PubMed Central

    Zhao, Yili; Zhou, Peter; Liu, Baoling; Bambakidis, Ted; Mazitschek, Ralph; Alam, Hasan B.; Li, Yongqing

    2014-01-01

    BACKGROUND Lipopolysaccharide (LPS) has a deleterious effect on several organs including the liver and eventually leads to endotoxic shock and death. LPS-induced hepatotoxicity is characterized by disturbed intracellular redox balance and excessive reactive oxygen species (ROS) accumulation, leading to liver injury. We have shown that treatment with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor (HDACI), improves survival in a murine model of LPS-induced shock, but the protective effect of SAHA against liver damage remains unknown. The goal of this study was to investigate the mechanism underlying SAHA action in murine livers. METHOD Male C57BL/6J mice (6-8 weeks) weighing 20-25 g were randomly divided into three groups: (A) a sham group was given isotonic sodium chloride solution (10 μL/g body weight, intraperitoneal, i.p.) with DMSO (1 μl/g body weight, i.p.); (B) a LPS group was challenged with LPS (20 mg/kg, i.p.) dissolved in isotonic sodium chloride solution with DMSO; (C) a LPS plus SAHA group was treated with SAHA (50 mg/kg, i.p.) dissolved in DMSO immediately after injection of LPS (20 mg/kg, i.p.). Mice were anesthetized, and their livers were harvested 6 or 24 hours after injection to analyze whether SAHA affected production of reactive oxygen species (ROS) and activation of apoptotic proteins in the liver cells of challenged mice. RESULTS SAHA counteracted LPS-induced production of ROS (thiobarbituric acid reactive substances (TBARS) and nitrite) and reversed an LPS-induced decrease in antioxidant enzyme, glutathione (GSH). SAHA also attenuated LPS-induced hepatic apoptosis. Moreover, SAHA inhibited activation of the redox-sensitive kinase, apoptosis signal-regulating kinase-1 (ASK1), and the mitogen-activated protein kinases (MAPKs) p38 and Jun N-terminal kinase (JNK). CONCLUSION Our data indicates, for the first time, that SAHA is capable of alleviating LPS-induced hepatotoxicity and suggests that a blockade of the upstream

  20. Broiler pulmonary hypertensive responses during lipopolysaccharide-induced tolerance and cyclooxygenase inhibition.

    PubMed

    Wideman, R F; Bowen, O T; Erf, G F

    2009-01-01

    Bacterial lipopolysaccharide (LPS, endotoxin) triggers pulmonary hypertension (PH) characterized by an increase in pulmonary arterial pressure (PAP) that reaches a peak value within 20 to 25 min and then gradually subsides within 60 min. As the PAP subsides PH cannot be reinitiated, signifying the onset of a period of tolerance (refractoriness) to repeated LPS exposure. The present study was conducted to determine the duration of this tolerance, and to evaluate key mediators thought to contribute to LPS-mediated PH in broilers. Tolerance was shown to persist for 4 to 5 d after the initial exposure to LPS. In tolerant broilers supramaximal i.v. injections of LPS did not reinitiate PH, nor was a significant modulatory role for nitric oxide demonstrated. The pulmonary vasculature of tolerant broilers remains responsive to the thromboxane A(2) (TxA(2)) mimetic U44069, 5-hydroxytryptamine (5-HT, serotonin), and constitutive nitric oxide. Meclofenamate successfully blocked the conversion of arachidonic acid to vasoconstrictive eicosanoids such as TxA(2); nevertheless, meclofenamate failed to inhibit PH in response to LPS. Therefore, TxA(2) does not appear to be the primary vasoconstrictor involved in the PH response to LPS and neither does 5-HT. Broilers emerging from tolerance 5 d after the initial exposure to LPS exhibited interindividual variation in their PH responsiveness to a second LPS injection, ranging from zero response (individuals that remain fully tolerant) to large increases in PAP (post-tolerant individuals). Tolerance might be an important compensatory or protective mechanism for broilers whose pulmonary vascular capacity is marginally adequate under optimal conditions, and whose respiratory systems are chronically challenged with LPS in commercial production facilities. The key vasoconstrictors responsible for the PH elicited by LPS remain to be determined. PMID:19096060

  1. Lipopolysaccharide-Induced Dynamic Lipid Membrane Reorganization: Tubules, Perforations, and Stacks

    PubMed Central

    Adams, Peter G.; Lamoureux, Loreen; Swingle, Kirstie L.; Mukundan, Harshini; Montaño, Gabriel A.

    2014-01-01

    Lipopolysaccharide (LPS) is a unique lipoglycan, with two major physiological roles: 1), as a major structural component of the outer membrane of Gram-negative bacteria and 2), as a highly potent mammalian toxin when released from cells into solution (endotoxin). LPS is an amphiphile that spontaneously inserts into the outer leaflet of lipid bilayers to bury its hydrophobic lipidic domain, leaving the hydrophilic polysaccharide chain exposed to the exterior polar solvent. Divalent cations have long been known to neutralize and stabilize LPS in the outer membrane, whereas LPS in the presence of monovalent cations forms highly mobile negatively-charged aggregates. Yet, much of our understanding of LPS and its interactions with the cell membrane does not take into account its amphiphilic biochemistry and charge polarization. Herein, we report fluorescence microscopy and atomic force microscopy analysis of the interaction between LPS and fluid-phase supported lipid bilayer assemblies (sLBAs), as model membranes. Depending on cation availability, LPS induces three remarkably different effects on simple sLBAs. Net-negative LPS-Na+ leads to the formation of 100-μm-long flexible lipid tubules from surface-associated lipid vesicles and the destabilization of the sLBA resulting in micron-size hole formation. Neutral LPS-Ca2+ gives rise to 100-μm-wide single- or multilamellar planar sheets of lipid and LPS formed from surface-associated lipid vesicles. Our findings have important implications about the physical interactions between LPS and lipids and demonstrate that sLBAs can be useful platforms to study the interactions of amphiphilic virulence factors with cell membranes. Additionally, our study supports the general phenomenon that lipids with highly charged or bulky headgroups can promote highly curved membrane architectures due to electrostatic and/or steric repulsions. PMID:24896118

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

    PubMed Central

    2012-01-01

    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 infection contributes to

  3. Galantamine protects against lipopolysaccharide-induced acute lung injury in rats.

    PubMed

    Li, G; Zhou, C L; Zhou, Q S; Zou, H D

    2016-02-01

    Lipopolysaccharide (LPS)-induced endotoxemia triggers the secretion of proinflammatory cytokines and can cause acute lung injury (ALI). The high mobility group box 1 (HMGB1) protein plays an important role as a late mediator of sepsis and ALI. Galantamine (GAL) is a central acetylcholinesterase inhibitor that inhibits the expression of HMGB1. This study evaluated the effects of GAL by measuring levels of inflammatory mediators and observing histopathological features associated with LPS-induced ALI. Sixty 8-10 week old male Sprague-Dawley rats (200-240 g) were randomized into three groups as follows: control group, LPS group (7.5 mg/kg LPS), and LPS+GAL group (5 mg/kg GAL before LPS administration). Histopathological examination of lung specimens obtained 12 h after LPS administration was performed to analyze changes in wet-to-dry (W/D) weight ratio, myeloperoxidase (MPO) activity, and HMGB1 expression level. Additionally, plasma concentrations of tumor necrosis factor-α, interleukin-6, and HMGB1 were measured using an enzyme-linked immunosorbent assay at 0 (baseline), 3, 6, 9, and 12 h after LPS administration. Mortality in the three groups was recorded at 72 h. LPS-induced ALI was characterized by distortion of pulmonary architecture and elevation of MPO activity, W/D weight ratio, and levels of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-6, and HMGB1. Pretreatment with GAL significantly reduced the LPS-induced lung pathological changes, W/D weight ratio, levels of pro-inflammatory cytokines and MPO activity (ANOVA). Moreover, GAL treatment significantly decreased the mortality rate (ANOVA). In conclusion, we demonstrated that GAL exerted a protective effect on LPS-induced ALI in rats. PMID:26648090

  4. Recognition of Heptoses and the Inner Core of Bacterial Lipopolysaccharides by Surfactant Protein D

    SciTech Connect

    Wang,H.; Head, J.; Kosma, P.; Brade, H.; Muller-Loennies, S.; Sheikh, S.; McDonald, B.; Smith, K.; Cafarella, T.; et al

    2008-01-01

    Lipopolysaccharides (LPS) of Gram-negative bacteria are important mediators of bacterial virulence that can elicit potent endotoxic effects. Surfactant protein D (SP-D) shows specific interactions with LPS, both in vitro and in vivo. These interactions involve binding of the carbohydrate recognition domain (CRD) to LPS oligosaccharides (OS); however, little is known about the mechanisms of LPS recognition. Recombinant neck+CRDs (NCRDs) provide an opportunity to directly correlate binding interactions with a crystallographic analysis of the binding mechanism. In these studies, we examined the interactions of wild-type and mutant trimeric NCRDs with rough LPS (R-LPS). Although rat NCRDs bound more efficiently than human NCRDs to Escherichia coli J-5 LPS, both proteins exhibited efficient binding to solid-phase Rd2-LPS and to Rd2-LPS aggregates presented in the solution phase. Involvement of residues flanking calcium at the sugar binding site was demonstrated by reciprocal exchange of lysine and arginine at position 343 of rat and human CRDs. The lectin activity of hNCRDs was inhibited by specific heptoses, including l-glycero-{alpha}-d-manno-heptose (l, d-heptose), but not by 3-deoxy-{alpha}-d-manno-oct-2-ulosonic acid (Kdo). Crystallographic analysis of the hNCRD demonstrated a novel binding orientation for l, d-heptose, involving the hydroxyl groups of the side chain. Similar binding was observed for a synthetic {alpha}1{yields}3-linked heptose disaccharide corresponding to heptoses I and II of the inner core region in many LPS. 7-O-Carbamoyl-l, d-heptose and d-glycero-{alpha}-d-manno-heptose were bound via ring hydroxyl groups. Interactions with the side chain of inner core heptoses provide a potential mechanism for the recognition of diverse types of LPS by SP-D.

  5. Galantamine protects against lipopolysaccharide-induced acute lung injury in rats

    PubMed Central

    Li, G.; Zhou, CL.; Zhou, QS.; Zou, HD.

    2015-01-01

    Lipopolysaccharide (LPS)-induced endotoxemia triggers the secretion of proinflammatory cytokines and can cause acute lung injury (ALI). The high mobility group box 1 (HMGB1) protein plays an important role as a late mediator of sepsis and ALI. Galantamine (GAL) is a central acetylcholinesterase inhibitor that inhibits the expression of HMGB1. This study evaluated the effects of GAL by measuring levels of inflammatory mediators and observing histopathological features associated with LPS-induced ALI. Sixty 8-10 week old male Sprague-Dawley rats (200-240 g) were randomized into three groups as follows: control group, LPS group (7.5 mg/kg LPS), and LPS+GAL group (5 mg/kg GAL before LPS administration). Histopathological examination of lung specimens obtained 12 h after LPS administration was performed to analyze changes in wet-to-dry (W/D) weight ratio, myeloperoxidase (MPO) activity, and HMGB1 expression level. Additionally, plasma concentrations of tumor necrosis factor-α, interleukin-6, and HMGB1 were measured using an enzyme-linked immunosorbent assay at 0 (baseline), 3, 6, 9, and 12 h after LPS administration. Mortality in the three groups was recorded at 72 h. LPS-induced ALI was characterized by distortion of pulmonary architecture and elevation of MPO activity, W/D weight ratio, and levels of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-6, and HMGB1. Pretreatment with GAL significantly reduced the LPS-induced lung pathological changes, W/D weight ratio, levels of pro-inflammatory cytokines and MPO activity (ANOVA). Moreover, GAL treatment significantly decreased the mortality rate (ANOVA). In conclusion, we demonstrated that GAL exerted a protective effect on LPS-induced ALI in rats. PMID:26648090

  6. Vitamin D3 pretreatment regulates renal inflammatory responses during lipopolysaccharide-induced acute kidney injury

    PubMed Central

    Xu, Shen; Chen, Yuan-Hua; Tan, Zhu-Xia; Xie, Dong-Dong; Zhang, Cheng; Zhang, Zhi-Hui; Wang, Hua; Zhao, Hui; Yu, De-Xin; Xu, De-Xiang

    2015-01-01

    Vitamin D receptor (VDR) is highly expressed in human and mouse kidneys. Nevertheless, its functions remain obscure. This study investigated the effects of vitamin D3 (VitD3) pretreatment on renal inflammation during lipopolysaccharide (LPS)-induced acute kidney injury. Mice were intraperitoneally injected with LPS. In VitD3 + LPS group, mice were pretreated with VitD3 (25 μg/kg) at 48, 24 and 1 h before LPS injection. As expected, an obvious reduction of renal function and pathological damage was observed in LPS-treated mice. VitD3 pretreatment significantly alleviated LPS-induced reduction of renal function and pathological damage. Moreover, VitD3 pretreatment attenuated LPS-induced renal inflammatory cytokines, chemokines and adhesion molecules. In addition, pretreatment with 1,25(OH)2D3, the active form of VitD3, alleviated LPS-induced up-regulation of inflammatory cytokines and chemokines in human HK-2 cells, a renal tubular epithelial cell line, in a VDR-dependent manner. Further analysis showed that VitD3, which activated renal VDR, specifically repressed LPS-induced nuclear translocation of nuclear factor kappa B (NF-κB) p65 subunit in the renal tubules. LPS, which activated renal NF-κB, reciprocally suppressed renal VDR and its target gene. Moreover, VitD3 reinforced the physical interaction between renal VDR and NF-κB p65 subunit. These results provide a mechanistic explanation for VitD3-mediated anti-inflammatory activity during LPS-induced acute kidney injury. PMID:26691774

  7. Vitamin D3 pretreatment regulates renal inflammatory responses during lipopolysaccharide-induced acute kidney injury.

    PubMed

    Xu, Shen; Chen, Yuan-Hua; Tan, Zhu-Xia; Xie, Dong-Dong; Zhang, Cheng; Zhang, Zhi-Hui; Wang, Hua; Zhao, Hui; Yu, De-Xin; Xu, De-Xiang

    2015-01-01

    Vitamin D receptor (VDR) is highly expressed in human and mouse kidneys. Nevertheless, its functions remain obscure. This study investigated the effects of vitamin D3 (VitD3) pretreatment on renal inflammation during lipopolysaccharide (LPS)-induced acute kidney injury. Mice were intraperitoneally injected with LPS. In VitD3 + LPS group, mice were pretreated with VitD3 (25 μg/kg) at 48, 24 and 1 h before LPS injection. As expected, an obvious reduction of renal function and pathological damage was observed in LPS-treated mice. VitD3 pretreatment significantly alleviated LPS-induced reduction of renal function and pathological damage. Moreover, VitD3 pretreatment attenuated LPS-induced renal inflammatory cytokines, chemokines and adhesion molecules. In addition, pretreatment with 1,25(OH)2D3, the active form of VitD3, alleviated LPS-induced up-regulation of inflammatory cytokines and chemokines in human HK-2 cells, a renal tubular epithelial cell line, in a VDR-dependent manner. Further analysis showed that VitD3, which activated renal VDR, specifically repressed LPS-induced nuclear translocation of nuclear factor kappa B (NF-κB) p65 subunit in the renal tubules. LPS, which activated renal NF-κB, reciprocally suppressed renal VDR and its target gene. Moreover, VitD3 reinforced the physical interaction between renal VDR and NF-κB p65 subunit. These results provide a mechanistic explanation for VitD3-mediated anti-inflammatory activity during LPS-induced acute kidney injury. PMID:26691774

  8. Nitric oxide isoenzymes regulate lipopolysaccharide-enhanced insulin transport across the blood-brain barrier.

    PubMed

    Banks, William A; Dohgu, Shinya; Lynch, Jessica L; Fleegal-DeMotta, Melissa A; Erickson, Michelle A; Nakaoke, Ryota; Vo, Than Q

    2008-04-01

    Insulin transported across the blood-brain barrier (BBB) has many effects within the central nervous system. Insulin transport is not static but altered by obesity and inflammation. Lipopolysaccharide (LPS), derived from the cell walls of Gram-negative bacteria, enhances insulin transport across the BBB but also releases nitric oxide (NO), which opposes LPS-enhanced insulin transport. Here we determined the role of NO synthase (NOS) in mediating the effects of LPS on insulin BBB transport. The activity of all three NOS isoenzymes was stimulated in vivo by LPS. Endothelial NOS and inducible NOS together mediated the LPS-enhanced transport of insulin, whereas neuronal NOS (nNOS) opposed LPS-enhanced insulin transport. This dual pattern of NOS action was found in most brain regions with the exception of the striatum, which did not respond to LPS, and the parietal cortex, hippocampus, and pons medulla, which did not respond to nNOS inhibition. In vitro studies of a brain endothelial cell (BEC) monolayer BBB model showed that LPS did not directly affect insulin transport, whereas NO inhibited insulin transport. This suggests that the stimulatory effect of LPS and NOS on insulin transport is mediated through cells of the neurovascular unit other than BECs. Protein and mRNA levels of the isoenzymes indicated that the effects of LPS are mainly posttranslational. In conclusion, LPS affects insulin transport across the BBB by modulating NOS isoenzyme activity. NO released by endothelial NOS and inducible NOS acts indirectly to stimulate insulin transport, whereas NO released by nNOS acts directly on BECs to inhibit insulin transport. PMID:18187549

  9. Sepsis progression to multiple organ dysfunction in carotid chemo/baro-denervated rats treated with lipopolysaccharide.

    PubMed

    Nardocci, Gino; Martin, Aldo; Abarzúa, Sebastián; Rodríguez, Jorge; Simon, Felipe; Reyes, Edison P; Acuña-Castillo, Claudio; Navarro, Cristina; Cortes, Paula P; Fernández, Ricardo

    2015-01-15

    Sepsis progresses to multiple organ dysfunction (MOD) due to the uncontrolled release of inflammatory mediators. Carotid chemo/baro-receptors could play a protective role during sepsis. In anesthetized male rats, we measured cardiorespiratory variables and plasma TNF-α, glucocorticoids, epinephrine, and MOD marker levels 90min after lipopolysaccharide (LPS) administration in control (SHAM surgery) and bilateral carotid chemo/baro-denervated (BCN) rats. BCN prior to LPS blunted the tachypneic response and enhanced tachycardia and hypotension. BCN-LPS rats also showed blunted plasma glucocorticoid responses, boosted epinephrine and TNF-α responses, and earlier MOD onset with a lower survival time compared with SHAM-LPS rats. Consequently, the complete absence of carotid chemo/baro-sensory function modified the neural, endocrine and inflammatory responses to sepsis. Thus, carotid chemo/baro-receptors play a protective role in sepsis. PMID:25595251

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

    PubMed Central

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

    2011-01-01

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

  11. The core and O-polysaccharide structure of the Caulobacter crescentus lipopolysaccharide.

    PubMed

    Jones, Michael D; Vinogradov, Evgeny; Nomellini, John F; Smit, John

    2015-01-30

    Here we describe the analysis of the structure of the lipopolysaccharide (LPS) from Caulobacter crescentus strain JS1025, a derivative of C. crescentus CB15 NA1000 with an engineered amber mutation in rsaA, leading to the loss of the protein S-layer and gene CCNA_00471 encoding a putative GDP-L-fucose synthase. LPS was isolated using an aqueous membrane disruption method. Polysaccharide and core oligosaccharide were produced by mild acid hydrolysis and analyzed by nuclear magnetic resonance spectroscopy and chemical methods. Spectra revealed the presence of two polysaccharides, one of them, a rhamnan, could be removed using periodate oxidation. Another polymer, built from 4-amino-4-deoxy-D-rhamnose (perosamine), mannose, and 3-O-methyl-glucose, should be the O-chain of the LPS according to genetic data. The attribution of the rhamnan as a part of LPS or a separate polymer was not possible. PMID:25498010

  12. Biphasic effects of muramyl dipeptide or lipopolysaccharide on superoxide anion-generating activities of macrophages.

    PubMed Central

    Yagawa, K; Kaku, M; Ichinose, Y; Nagao, S; Tanaka, A; Tomoda, A

    1984-01-01

    The superoxide anion (O2-)-generating activity of guinea pig macrophages stimulated by wheat germ agglutinin (WGA), immune complexes, or phorbol myristate acetate (PMA) was studied after short- and long-term exposures of the cells to muramyl dipeptide (MDP) or lipopolysaccharide (LPS). Neither MDP nor LPS alone induced O2- release in macrophages. Short-term (30 min) exposure to these agents caused the enhanced release of O2- in response to WGA or immune complexes, though the PMA-induced O2- generation was not affected. On the other hand, long-term exposure (more than 24 h) to MDP or LPS progressively enhanced O2- generation of the cells induced by WGA, immune complexes, or even PMA. These results suggest that the mechanism for O2- generation of macrophages stimulated by WGA or immune complexes differs from that stimulated by PMA and that the differences also exist between short- and long-term exposure to MDP or LPS. PMID:6329960

  13. Upregulation of PRDM5 Is Associated with Astrocyte Proliferation and Neuronal Apoptosis Caused by Lipopolysaccharide.

    PubMed

    Zhang, Yu; Liu, Xiaojuan; Xue, Huaqing; Liu, Xiaorong; Dai, Aihua; Song, Yan; Ke, Kaifu; Cao, Maohong

    2016-05-01

    PRDM5 (PR domain containing 5) belongs to PRDM family which consists of transcriptional regulators that modulate cellular processes such as cell growth, differentiation and apoptosis. However, the function of PRDM5 in central nervous system (CNS) inflammatory response is unknown. In recent study, an adult rat neuroinflammation model via lipopolysaccharide (LPS) lateral ventricle injection was constructed. PRDM5 expression was increased in activated astrocytes and apoptotic neurons of the adult rat cerebral cortex after LPS injection. In vitro studies showed that the remarkable upregulation of PRDM5 might be involved in rat primary astrocyte proliferation and rat primary neuronal apoptosis in the cerebral cortex following LPS administration. In addition, using PRDM5 RNA interference both in rat primary asrtocytes and neurons, further indicated that PRDM5 was required for astrocyte proliferation and neuronal apoptosis induced by LPS. Our findings on the cellular signaling pathway may provide a new therapeutic strategy against neuroinflammation in the CNS. PMID:27074744

  14. Efficient method for preparation of highly purified lipopolysaccharides by hydrophobic interaction chromatography.

    PubMed

    Muck, A; Ramm, M; Hamburger, M

    1999-09-10

    A method for the efficient preparation of highly purified lipopolysaccharides (LPSs) by hydrophobic interaction chromatography (HIC) has been developed. The procedure can be used for the purification of cell wall bound LPSs after hot phenol-water extraction and for the isolation of extracellular LPSs from the supernatant, respectively. The method described has been tested with artificial mixtures containing LPSs, polysaccharide, protein and RNA and subsequently employed for the preparative purification of two LPSs of different origin, namely the extracellular LPS secreted by Escherichia coli E49 into the culture medium, and the cell wall bound LPS from Pseudomonas aeruginosa VA11465/1. Compared to currently used methods for LPS purification such as enzymatic digestion and ultracentrifugation, the chromatographic separation reported here combines superior purity with minimal loss of LPS, high reproducibility and simple handling. The removal of contaminants such as protein, RNA and polysaccharides and the recovery of LPSs were monitored by appropriate assays. PMID:10517220

  15. Gram-Negative Marine Bacteria: Structural Features of Lipopolysaccharides and Their Relevance for Economically Important Diseases

    PubMed Central

    Anwar, Muhammad Ayaz; Choi, Sangdun

    2014-01-01

    Gram-negative marine bacteria can thrive in harsh oceanic conditions, partly because of the structural diversity of the cell wall and its components, particularly lipopolysaccharide (LPS). LPS is composed of three main parts, an O-antigen, lipid A, and a core region, all of which display immense structural variations among different bacterial species. These components not only provide cell integrity but also elicit an immune response in the host, which ranges from other marine organisms to humans. Toll-like receptor 4 and its homologs are the dedicated receptors that detect LPS and trigger the immune system to respond, often causing a wide variety of inflammatory diseases and even death. This review describes the structural organization of selected LPSes and their association with economically important diseases in marine organisms. In addition, the potential therapeutic use of LPS as an immune adjuvant in different diseases is highlighted. PMID:24796306

  16. Gene expression profiles in the intestine of lipopolysaccharide-challenged piglets.

    PubMed

    Yi, Dan; Hou, Yongqing; Wang, Lei; Zhao, Di; Ding, Binying; Wu, Tao; Chen, Hongbo; Liu, Yulan; Kang, Ping; Wu, Guoyao

    2016-01-01

    Bowel diseases are common in human and animals and are characterized by intestinal dysfunction and injury. A well-established porcine model of intestinal injury can be induced by lipopolysaccharide (LPS), an endotoxin released from the cell wall of pathogenic bacteria. LPS affects the expression of genes associated with intestinal immune response, mucosal growth, energy metabolism, absorption, mucosal barrier function, and antiviral function. Transcriptional analysis of intestinal genes reveals that the duodenum, jejunum, ileum and colon respond to LPS challenge in a similar pattern. Moreover, the jejunum and ileum exhibit greater responses to LPS challenge than the duodenum and colon with regard to gene expression. Additionally, over 85% of genes are co-expressed along the small and large intestines and there is a clear distinction in gene expression patterns amongst the different intestinal segments in pigs. These findings have important implications for underlying molecular mechanisms responsible for endotoxin-induced intestinal injury and dysfunction. PMID:26709789

  17. Wet heat inactivation of lipopolysaccharide from E. coli serotype 055:B5.

    PubMed

    Fujii, Shinji; Takai, Masaki; Maki, Takehiko

    2002-01-01

    Wet heat inactivation of lipopolysaccharide (LPS) from E. coli Serotype 055:B5 was investigated. The LPS solutions were heated at study temperatures ranging from 78 degrees C to 175 degrees C, and were assayed using the Limulus Amebocyte Lysate (LAL) test. Plots of the log of the amount of endotoxin remaining versus heating time showed biphasic decreases. The initial slopes are associated with a faster rate of decrease to about a 0.5-log unit reduction, and were followed by a slower, linear rate of decline in the secondary slopes. The curves were applied to the biexponential model expressed by the equation (Et = E1e-klt + E2e-k2t). The LPS inactivation rates (k1 and k2) each conformed to their own Arrhenius equation. Therefore, the processes required to achieve the desired level of LPS inactivation can be obtained by mathematical means. PMID:12181806

  18. Cyclooxygenase-1 is involved in the inhibition of hippocampal neurogenesis after lipopolysaccharide-induced neuroinflammation

    PubMed Central

    Russo, Isabella; Amornphimoltham, Panomwat; Weigert, Roberto; Barlati, Sergio

    2011-01-01

    Growing evidence indicates that neuroinflammation can alter adult neurogenesis by mechanisms as yet unclear. We have previously demonstrated that the neuroinflammatory response and neuronal damage after lipopolysaccharide (LPS) injection is reduced in cyclooxygenase-1 deficient (COX-1-/-) mice. In this study, we investigated the role of CoX-1 on hippocampal neurogenesis during LPS-induced neuroinflammation, using COX-1-/- and wild-type (WT) mice. We found that LPS-induced neuroinflammation resulted in the decrease of proliferation, survival and differentiation of hippocampal progenitor cells in WT but not in COX-1-/- mice. Thus, we demonstrate for the first time that COX-1 is involved in the inhibition of BrdU progenitor cells in proliferation and hippocampal neurogenesis after LPS. These results suggest that COX-1 may represent a viable therapeutic target to reduce neuroinflammation and promote neurogenesis in neurodegenerative diseases with a strong inflammatory component. PMID:21694498

  19. Effects of Porphyromonas gingivalis and Escherichia coli lipopolysaccharides on mononuclear phagocytes.

    PubMed Central

    Roberts, F A; Richardson, G J; Michalek, S M

    1997-01-01

    The mononuclear phagocyte plays an important role in the regulation of microbe-induced inflammation, in part through its ability to secrete mediators, particularly cytokines, in response to microorganisms and their products. To evaluate the effects of the microbial flora associated with chronic adult periodontitis on cytokine induction, lipopolysaccharide (LPS) from the periodontopathogen Porphyromonas gingivalis was used to stimulate naive and phorbol ester-primed U937 monocytic cells, as well as elutriated human peripheral blood monocytes. We assessed the effect of this LPS, in comparison to that of LPS from Escherichia coli, on cell proliferation, cytokine induction, and surface expression of the LPS receptor CD14. P. gingivalis LPS stimulated proliferation of U937 cells at concentrations of greater than 1 ng/ml, while E. coli LPS inhibited proliferation. Phorbol myristic acid (PMA)-treated U937 cells and elutriated monocytes responded to E. coli LPS activation by producing tumor necrosis factor alpha (TNF-alpha) mRNA and protein; however, P. gingivalis LPS induced greater numbers of TNF-alpha mRNA-positive cells and higher (P < 0.05) levels of protein than did E. coli LPS. Both cell types expressed interleukin-1 beta (IL-1beta) mRNA and protein in response to either LPS treatment. Compared with E. coli LPS, P. gingivalis LPS induced significantly (P < 0.05) higher numbers of IL-1 mRNA-positive U937 cells and elutriated monocytes, as well as production of significantly more (P < 0.05) IL-1 protein by the monocytes. The PMA-treated U937 cells and the monocytes produced high levels of IL-1 receptor antagonist mRNA and protein which were only marginally affected by the LPS preparations. While E. coli LPS induced expression of CD 14 on the surface of PMA-primed U937 cells and monocytes, P. gingivalis LPS exhibited a significantly (P < 0.05) greater ability to enhance receptor levels. Our results indicate that P. gingivalis LPS can activate the mononuclear phagocyte

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

    PubMed Central

    Andoh, Tsugunobu; Ouchi, Kenji; Inatomi, Satoshi

    2014-01-01

    Pleurotus eryngii (P. eryngii) is consumed as a fresh cultivated mushroom worldwide and demonstrated to have multiple beneficial effects. We investigated the anti-inflammatory effect of P. eryngii in mice with acute lung injury (ALI). Intranasal instillation of lipopolysaccharide (LPS) (10 μg/site/mouse) induced marked lung inflammation (increase in the number of inflammatory cells, protein leakage, and production of nitric oxide in bronchoalveolar lavage fluid) as well as histopathological damage in the lung, 6 h after treatment. Mice administered heat-treated P. eryngii (0.3–1 g/kg, p.o. (HTPE)) 1 h before LPS challenge showed decreased pulmonary inflammation and ameliorated histopathological damage. These results suggest that HTPE has anti-inflammatory effects against ALI. Thus, P. eryngii itself may also have anti-inflammatory effects and could be a beneficial food for the prevention of ALI induced by bacterial infection. PMID:24799939

  1. Structural investigation of the antagonist LPS from the cyanobacterium Oscillatoria planktothrix FP1.

    PubMed

    Carillo, Sara; Pieretti, Giuseppina; Bedini, Emiliano; Parrilli, Michelangelo; Lanzetta, Rosa; Corsaro, Maria Michela

    2014-03-31

    Cyanobacteria are aquatic and photosynthetic microorganisms, which contribute up to 30% of the yearly oxygen production on the earth. They have the distinction of being the oldest known fossils, more than 3.5 billion years old, and are one of the largest and most important groups of bacteria on earth. Cyanobacteria are an emerging source of potentially pharmacologically active products and, among these, there are the lipopolysaccharides. Despite their significant and well documented activity, very little is known about the cyanobacteria lipopolysaccharides (LPS) structure. The aim of this work is to investigate the structure of the highly TLR4-antagonist lipopolysaccharide from the cyanobacterium Oscillatoria plankthotrix FP1. The LPS was purified and analysed by means of chemical analysis and 1H and 13C NMR spectroscopy. The LPS was then degraded by Smith degradation, HF and acetic acid hydrolyses. All the obtained products were investigated in detail by chemical analysis, NMR spectroscopy and by mass spectrometry. The LPS consists of a high molecular mass and very complex molecule lacking Kdo and heptose residues, where the polysaccharide chain is mainly constituted by a backbone of 3-substituted α-l-rhamnose units. The core region is rich in galacturonic acid and mannose residues. Moreover a glycolipid portion, similar to Gram-negative lipid A, was identified. This was built up of a non phosphorylated (1'→6) linked glucosamine disaccharide, acylated with 3-hydroxylated fatty acids. In particular 3-hydroxypentadecanoic and 3-hydroxyesadecanoic acids were found, together with esadecanoic and tetradecanoic ones. Finally the presence of a galacturonic acid residue at 6-position of the distal glucosamine in place of the Kdo residue is suggested. PMID:24632212

  2. Macrophage cytokine response to particles and lipopolysaccharide in vitro.

    PubMed

    Daniels, A U; Barnes, F H; Charlebois, S J; Smith, R A

    2000-03-15

    Several investigators have suggested that biologic molecules adsorbed onto particles may play a key role in determining macrophage response. Adsorbed endotoxins (bacterial debris) may be of particular importance since they are widely present exogenously and endogenously and adhere strongly to many materials. Murine-transformed peritoneal macrophages (IC-21) were used in this in vitro study. Secretions of IL-1 beta, TNF alpha, and IL-6 were used as a measure of macrophage response to micron-range particles of high-density polyethylene and Co-Cr-Mo alloy, with and without adsorbed lipopolysaccharide (LPS) endotoxin. Little cytokine secretion was measured in response to particles (and to polypropylene experimental chambers) cleaned with ethanol and saline and not exposed to LPS. The lack of macrophage response to cleaned particles has been reported by others and may help reconcile conflicting reports in the literature. Cytokine secretion levels were high in all cases if the chambers (with or without particles) were exposed to LPS (and rinsed to minimize nonbound LPS). Secretion patterns were different with particles present and for polymer versus metal particles. Overall, these results suggest that (1) adsorbed molecules on material surfaces strongly affect macrophage response and (2) particle surface chemistry and microstructure affect the concentration and configuration of adsorbed molecules, further influencing particle interaction with macrophage surface receptors. PMID:10602080

  3. Arctigenin attenuates lipopolysaccharide-induced acute lung injury in rats.

    PubMed

    Shi, Xianbao; Sun, Hongzhi; Zhou, Dun; Xi, Huanjiu; Shan, Lina

    2015-04-01

    Arctigenin (ATG) has been reported to possess anti-inflammatory properties. However, the effects of ATG on lipopolysaccharide (LPS)-induced acute lung injury (ALI) remains not well understood. In the present study, our investigation was designed to reveal the effect of ATG on LPS-induced ALI in rats. We found that ATG pretreatment attenuated the LPS-induced ALI, as evidenced by the reduced histological scores, myeloperoxidase activity, and wet-to-dry weight ratio in the lung tissues. This was accompanied by the decreased levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-1 (IL-6) in the bronchoalveolar lavage fluid. Furthermore, ATG downregulated the expression of nuclear factor kappa B (NF-κB) p65, promoted the phosphorylation of inhibitor of nuclear factor-κB-α (IκBα) and activated the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPKα) in the lung tissues. Our results suggested that ATG attenuates the LPS-induced ALI via activation of AMPK and suppression of NF-κB signaling pathway. PMID:25008149

  4. Proteomic Changes in Chicken Plasma Induced by Salmonella typhimurium Lipopolysaccharides

    PubMed Central

    Packialakshmi, Balamurugan; Liyanage, Rohana; Lay, Jackson O.; Makkar, Sarbjeet K.; Rath, Narayan C.

    2016-01-01

    Lipopolysaccharides (LPS) are cell wall components of Gram-negative bacteria that produce inflammation and sickness in higher animals. The objective was to identify plasma proteomic changes in an avian model of inflammation. Chickens were treated with either saline or LPS, and blood was collected at 24 hours postinjection. The pooled plasma samples were depleted of high-abundant proteins and analyzed by matrix-assisted laser desorption ionization (MALDI)-time-of-flight mass spectrometry and liquid chromatography–tandem mass spectrometry (LC–MS/MS). MALDI analyses showed an increase in fibrinogen beta-derived peptide and a decrease in apolipoprotein-AII-derived peptide in LPS samples. Label-free quantitation of LC–MS/MS spectra revealed an increase in the levels of α1-acid glycoprotein, a chemokine CCLI10, and cathelicidin-2, but a decrease in an interferon-stimulated gene-12-2 protein in the LPS group. These differentially expressed proteins are associated with immunomodulation, cytokine changes, and defense mechanisms, which may be useful as candidate biomarkers of infection and inflammation. PMID:27053921

  5. [SEROLOGICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF PANTOEA AGGLOMERANS LIPOPOLYSACCHARIDES].

    PubMed

    Bulygina, T V; Yakovleva, L M; Brovarska, O S; Varbanets, L D

    2015-01-01

    The serological and phytotoxic properties of lipopolysaccharide (LPS) of plant pathogens--Pantoea agglomerans were studied. It is known that the thin variations in the structure of the O-specific polysaccharides determining serological specificity of gram- negative bacteria and used as a molecular basis of serological classification schemes. For P. agglomerans still does not exist a classification scheme based on serology specificity of their LPS. The results of cross serological tests demonstrate immunochemical heterogeneity of species P agglomerans. Only three strains of the 8488, 8490 and 7969 according to the agglutination of O-antigens and direct hemagglutination and inhibition direct hemagglutination can be attributed to a single serogroup. Other strains--each separate group, although some have a relationship. Compared with control plants under the influence of seed treatment of LPS in plants may be reduced, and in some cases increased root length, height and weight sprout, depending on the strain from which the selected LPS. Dive seedlings of tomatoes in the solutions of the studied preparations FSC caused the loss, and after some time, restore turgor. PMID:26829835

  6. Passive transfer of leishmania lipopolysaccharide confers parasite survival in macrophages

    SciTech Connect

    Handman, E.; Schnur, L.F.; Spithill, T.W.; Mitchell, G.F.

    1986-12-01

    Infection of macrophages by the intracellular protozoan parasite Leishmania involves specific attachment to the host membrane, followed by phagocytosis and intracellular survival and growth. Two parasite molecules have been implicated in the attachment event: Leishmania lipopolysaccharide (L-LPS) and a glycoprotein (gp63). This study was designed to clarify the role of L-LPS in infection and the stage in the process of infection at which it operates. The authors have recently identified a Leishmania major strain (LRC-L119) which lacks the L-LPS molecule and is not infective for hamsters or mice. This parasite was isolated from a gerbil in Kenya and was identified phenotypically as L. major by isoenzyme and fatty acid analysis. In this study they have confirmed at the genotype level that LRC-L119 is L. major by analyzing and comparing the organization of cloned DNA sequences in the genome of different strains of L. major. Here they show that LRC-L119 promastigotes are phagocytosed rapidly by macrophages in vitro, but in contrast to virulent strains of L. major, they are then killed over a period of 18 hr. In addition, they show that transfer of purified L-LPS from a virulent clone of L. major (V121) into LRC-L119 promastigotes confers on them the ability to survive in macrophages in vitro.

  7. Lipopolysaccharide-Induced Apoptosis of Astrocytes: Therapeutic Intervention by Minocycline.

    PubMed

    Sharma, Arpita; Patro, Nisha; Patro, Ishan K

    2016-05-01

    Astrocytes are most abundant glial cell type in the brain and play a main defensive role in central nervous system against glutamate-induced toxicity by virtue of numerous transporters residing in their membranes and an astrocyte-specific enzyme glutamine synthetase (GS). In view of that, a dysregulation in the astrocytic activity following an insult may result in glutamate-mediated toxicity accompanied with astrocyte and microglial activation. The present study suggests that the lipopolysaccharide (LPS)-induced inflammation results in significant astrocytic apoptosis compared to other cell types in hippocampus and minocycline could not efficiently restrict the glutamate-mediated toxicity and apoptosis of astrocytes. Upon LPS exposure 76 % astrocytes undergo degeneration followed by 44 % oligodendrocytes, 26 % neurons and 10 % microglia. The pronounced astrocytic apoptosis resulted from the LPS-induced glutamate excitotoxicity leading to their hyperactivation as evident from their hypertrophied morphology, glutamate transporter 1 upregulation and downregulation of GS. Therapeutic minocycline treatment to LPS-infused rats efficiently restricted the inflammatory response and degeneration of other cell types but could not significantly combat with the apoptosis of astrocytes. Our study demonstrates a novel finding on cellular degeneration in the hippocampus revealing more of astrocytic death and suggests a more careful consideration on the protective efficacy of minocycline. PMID:26188416

  8. Lipopolysaccharide induces expression of collagen VI in the rat lung.

    PubMed

    Okawa, Sayuri; Unuma, Kana; Yamada, Atsushi; Aki, Toshihiko; Uemura, Koichi

    2015-01-01

    The involvement of the lung during the septic systemic inflammatory response elicited by administration of lipopolysaccharide (LPS) was investigated. Eight-week-old male Sprague-Dawley rats were injected i.p. with 15 mg/kg LPS. After 24 h, the lungs were excised to evaluate the cellular responses to LPS. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) analysis revealed that type VI collagen (ColVI) was extremely upregulated during sepsis in the rat lung within the first 24 h of LPS administration. Upregulation of ColVI protein and its mRNA was demonstrated by Western blot analysis, real time PCR, and immunohistochemistry. To the best of our knowledge, this is the first report demonstrating the activation of ColVI in the rat lung at the early stage of systemic inflammation. Activation of ColVI might be involved in sepsis-mediated lung fibrosis at an early stage. PMID:26023260

  9. Inhibitory Effects of Antimicrobial Peptides on Lipopolysaccharide-Induced Inflammation

    PubMed Central

    Sun, Yue; Shang, Dejing

    2015-01-01

    Antimicrobial peptides (AMPs) are usually small molecule peptides, which display broad-spectrum antimicrobial activity, high efficiency, and stability. For the multiple-antibiotic-resistant strains, AMPs play a significant role in the development of novel antibiotics because of their broad-spectrum antimicrobial activities and specific antimicrobial mechanism. Besides broad-spectrum antibacterial activity, AMPs also have anti-inflammatory activity. The neutralization of lipopolysaccharides (LPS) plays a key role in anti-inflammatory action of AMPs. On the one hand, AMPs can readily penetrate the cell wall barrier by neutralizing LPS to remove Gram-negative bacteria that can lead to infection. On the contrary, AMPs can also inhibit the production of biological inflammatory cytokines to reduce the inflammatory response through neutralizing circulating LPS. In addition, AMPs also modulate the host immune system by chemotaxis of leukocytes, to promote immune cell proliferation, epithelialization, and angiogenesis and thus play a protective role. This review summarizes some recent researches about anti-inflammatory AMPs, with a focus on the interaction of AMPs and LPS on the past decade. PMID:26612970

  10. [The protective activity of polyclonal and monoclonal antibodies to the lipopolysaccharide of Neisseria meningitidis serogroup A in in vivo experiments].

    PubMed

    Del'vig, A A; Krasnoproshina, L I; Volgareva, G M; Bobyleva, G V; Kuvakina, V I; Artem'eva, T A

    1990-10-01

    The protective activity of the sera of mice immunized with the preparations of native and detoxified N. meningitidis lipopolysaccharide (LPS), group A, as well as with monoclonal antibodies to N. meningitidis antigens, groups A and B, was studied on the mucin model of meningococcal infection. The study showed that the maximum level of anti-LPS antibodies in mice was observed on day 7 after the injection of LPS. Immune sera obtained from mice were capable of protecting the animals from fetal meningococcemia induced by N. meningitidis strains of homologous and heterologous groups. As shown by the results of this study, the alkaline treatment of N. meningitidis native LPS did not decrease the protective properties of antibodies. The monoclonal antibodies under study were found to possess high preventive activity in mice challenged with N. meningitidis, groups A and B. Anti-LPS monoclonal antibodies showed greater protective activity than antipolysaccharide monoclonal antibodies. PMID:2127501

  11. The role of IL-1β and glutamate in the effects of lipopolysaccharide on the hippocampal electrical kindling of seizures.

    PubMed

    Kołosowska, Karolina; Maciejak, Piotr; Szyndler, Janusz; Turzyńska, Danuta; Sobolewska, Alicja; Płaźnik, Adam

    2016-09-15

    In our study, we used rapid electrical hippocampal kindling and in vivo microdialysis methods to assess the involvement of inflammatory mediators: lipopolysaccharide (LPS) and proinflammatory interleukin-1β (IL-1β) in mechanisms of epileptogenesis. We observed, that both, LPS and IL-1β, administered into stimulated hippocampus, accelerated kindling process. LPS also increased the expression of IL-1β in stimulated hippocampus in kindled rats. In vivo acute LPS perfusion, via a microdialysis cannula implanted into the naïve rat's hippocampus, produced an increase in extracellular glutamate release. We suppose, that particularly IL-1β action and increased glutamate concentration may significantly contribute to LPS effects on kindling development. PMID:27609288

  12. Nilotinib ameliorates lipopolysaccharide-induced acute lung injury in rats

    SciTech Connect

    El-Agamy, Dina S.

    2011-06-01

    The present study aimed to investigate the effect of the new tyrosine kinase inhibitor, nilotinib on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats and explore its possible mechanisms. Male Sprague-Dawley rats were given nilotinib (10 mg/kg) by oral gavage twice daily for 1 week prior to exposure to aerosolized LPS. At 24 h after LPS exposure, bronchoalveolar lavage fluid (BALF) samples and lung tissue were collected. The lung wet/dry weight (W/D) ratio, protein level and the number of inflammatory cells in the BALF were determined. Optical microscopy was performed to examine the pathological changes in lungs. Malondialdehyde (MDA) content, superoxidase dismutase (SOD) and reduced glutathione (GSH) activities as well as nitrite/nitrate (NO{sub 2}{sup -}/NO{sub 3}{sup -}) levels were measured in lung tissues. The expression of inflammatory cytokines, tumor necrosis factor-{alpha} (TNF-{alpha}), transforming growth factor-{beta}{sub 1} (TGF-{beta}{sub 1}) and inducible nitric oxide synthase (iNOS) were determined in lung tissues. Treatment with nilotinib prior to LPS exposure significantly attenuated the LPS-induced pulmonary edema, as it significantly decreased lung W/D ratio, protein concentration and the accumulation of the inflammatory cells in the BALF. This was supported by the histopathological examination which revealed marked attenuation of LPS-induced ALI in nilotinib treated rats. In addition, nilotinib significantly increased SOD and GSH activities with significant decrease in MDA content in the lung. Nilotinib also reduced LPS mediated overproduction of pulmonary NO{sub 2}{sup -}/NO{sub 3}{sup -} levels. Importantly, nilotinib caused down-regulation of the inflammatory cytokines TNF-{alpha}, TGF-{beta}{sub 1} and iNOS levels in the lung. Taken together, these results demonstrate the protective effects of nilotinib against the LPS-induced ALI. This effect can be attributed to nilotinib ability to counteract the inflammatory cells

  13. Abrogating ClC-3 Inhibits LPS-induced Inflammation via Blocking the TLR4/NF-κB Pathway

    PubMed Central

    Xiang, Nan-lin; Liu, Jun; Liao, Yun-jian; Huang, You-wei; Wu, Zheng; Bai, Zhi-quan; Lin, Xi; Zhang, Jian-hua

    2016-01-01

    This study investigated the function of a chloride channel blocker, DIDS. Both in vitro and in vivo studies found that DIDS significantly inhibits lipopolysaccharide (LPS)-induced release of proin flammatory cytokines. Here, we show that DIDS inhibits LPS-induced inflammation, as shown by downregulation of inflammatory cytokines via inhibition of the TLR4/NF-κB pathway. Furthermore, we show that ClC-3siRNA transfection reduces LPS-induced pro-inflammation in Raw264.7 cells, indicating that ClC-3 is involved in the inhibitory effect of DIDS during LPS-induced cytokines release. In vivo, DIDS reduced LPS-induced mortality, decreased LPS-induced organic damage, and down-regulated LPS-induced expression of inflammatory cytokines. In sum, we demonstrate that ClC-3 is a pro-inflammatory factor and that inhibition of ClC-3 inhibits inflammatory induction both in vitro and in vivo, suggesting that ClC-3 is a potential anti-inflammatory target. PMID:27363391

  14. Ulinastatin attenuates LPS-induced human endothelial cells oxidative damage through suppressing JNK/c-Jun signaling pathway.

    PubMed

    Li, Chunping; Ma, Dandan; Chen, Man; Zhang, Linlin; Zhang, Lin; Zhang, Jicheng; Qu, Xin; Wang, Chunting

    2016-06-01

    Lipopolysaccharide (LPS)-induced oxidative stress is a main feature observed in the sepsis by increasing endothelial oxidative damage. Many studies have demonstrated that Ulinastatin (UTI) can inhibit pro-inflammatory proteases, decrease inflammatory cytokine levels and suppress oxidative stress. However, the potential molecular mechanism underlying UTI which exerts its antioxidant effect is not well understood. In this study, we aimed to investigate the effects of UTI on the LPS-induced oxidative stress and the underlying mechanisms using human umbilical vein endothelial cells (HUVECs). After oxidative stress induced By LPS in HUVECs, the cell viability and reactive oxygen species (ROS) in cytoplasm were measured. In addition, superoxide dismutase (SOD) and malondialdehyde (MDA) were examined. We found that LPS resulted in a profound elevation of ROS production and MDA levels. The decrease in Cu/Zn-SOD protein and increased in Mn-SOD protein were observed in a time- and dose-dependent manner. These responses were suppressed by an addition of UTI. The increase in c-Jun N-terminal kinases (JNK) phosphorylation by LPS in HUVECs was markedly blocked by UTI or JNK inhibitor SP600125. Our results suggest that UTI exerts its anti-oxidant effects by decreasing overproduction of ROS induced by LPS via suppressing JNK/c-Jun phosphorylation. Therefore UTI may play a protective role in vascular endothelial injury induced by oxidative stress such as sepsis. This study may provide insight into a possible molecular mechanism by which Ulinastatin inhibits LPS-induced oxidative stress. PMID:27109479

  15. Differential regulation of proinflammatory mediators following LPS- and ATP-induced activation of monocytes from patients with antiphospholipid syndrome.

    PubMed

    Martirosyan, Anush; Petrek, Martin; Navratilova, Zdenka; Blbulyan, Armen; Boyajyan, Anna; Manukyan, Gayane

    2015-01-01

    Antiphospholipid syndrome (APS) is an acquired autoimmune disorder characterized by recurrent thrombosis and pregnancy morbidity in association with the presence of antiphospholipid antibodies. Growing evidence supports the involvement of monocytes in APS pathogenesis. Inflammatory activation of monocytes promotes thrombus formation and other APS complications. However, mechanisms underlying their activation are poorly investigated. We aimed to determine transcriptional activity of monocytes after exposing them to low concentrations of lipopolysaccharide (LPS) and LPS + adenosine triphosphate (ATP) using comparative qRT-PCR. The results showed that LPS significantly increased transcriptional levels of TLR2, IL-23, CCL2, CXCL10, IL-1β, and IL-6 in APS cells, while, in cells from healthy donors, LPS resulted in IL-6 and STAT3 elevated mRNAs. Double stimulation of the cells resulted in decreased mRNA levels of NLRP3 in monocytes isolated from healthy donors and CCL2, IL-1β in APS cells. By contrast, TLR2 mRNAs were elevated in both investigated groups after culture of the cells with LPS + ATP. Thus, the findings indicate increased sensitivity of APS cells to LPS that may contribute to thrombus formation and enhance development or progression of autoimmune processes. Low concentrations of ATP diminish LPS-induced inflammatory state of APS monocytes which might be a potential mechanism which regulates inflammatory state of the cells. PMID:25785264

  16. Eriodictyol, a plant flavonoid, attenuates LPS-induced acute lung injury through its antioxidative and anti-inflammatory activity

    PubMed Central

    ZHU, GUANG-FA; GUO, HONG-JUAN; HUANG, YAN; WU, CHUN-TING; ZHANG, XIANG-FENG

    2015-01-01

    Acute lung injury (ALI) is characterized by excessive inflammatory responses and oxidative injury in the lung tissue. It has been suggested that anti-inflammatory or antioxidative agents could have therapeutic effects in ALI, and eriodictyol has been reported to exhibit antioxidative and anti-inflammatory activity in vitro. The aim of the present study was to investigate the effect of eriodictyol on lipopolysaccharide (LPS)-induced ALI in a mouse model. The mice were divided into four groups: Phosphate-buffered saline-treated healthy control, LPS-induced ALI, vehicle-treated ALI (LPS + vehicle) and eriodictyol-treated ALI (LPS + eriodictyol). Eriodictyol (30 mg/kg) was administered orally once, 2 days before the induction of ALI. The data showed that eriodictyol pretreatment attenuated LPS-induced ALI through its antioxidative and anti-inflammatory activity. Furthermore, the eriodictyol pretreatment activated the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway in the ALI mouse model, which attenuated the oxidative injury and inhibited the inflammatory cytokine expression in macrophages. In combination, the results of the present study demonstrated that eriodictyol could alleviate the LPS-induced lung injury in mice by regulating the Nrf2 pathway and inhibiting the expression of inflammatory cytokines in macrophages, suggesting that eriodictyol could be used as a potential drug for the treatment of LPS-induced lung injury. PMID:26668626

  17. Differential Regulation of Proinflammatory Mediators following LPS- and ATP-Induced Activation of Monocytes from Patients with Antiphospholipid Syndrome

    PubMed Central

    Martirosyan, Anush; Petrek, Martin; Navratilova, Zdenka; Blbulyan, Armen; Boyajyan, Anna; Manukyan, Gayane

    2015-01-01

    Antiphospholipid syndrome (APS) is an acquired autoimmune disorder characterized by recurrent thrombosis and pregnancy morbidity in association with the presence of antiphospholipid antibodies. Growing evidence supports the involvement of monocytes in APS pathogenesis. Inflammatory activation of monocytes promotes thrombus formation and other APS complications. However, mechanisms underlying their activation are poorly investigated. We aimed to determine transcriptional activity of monocytes after exposing them to low concentrations of lipopolysaccharide (LPS) and LPS + adenosine triphosphate (ATP) using comparative qRT-PCR. The results showed that LPS significantly increased transcriptional levels of TLR2, IL-23, CCL2, CXCL10, IL-1β, and IL-6 in APS cells, while, in cells from healthy donors, LPS resulted in IL-6 and STAT3 elevated mRNAs. Double stimulation of the cells resulted in decreased mRNA levels of NLRP3 in monocytes isolated from healthy donors and CCL2, IL-1β in APS cells. By contrast, TLR2 mRNAs were elevated in both investigated groups after culture of the cells with LPS + ATP. Thus, the findings indicate increased sensitivity of APS cells to LPS that may contribute to thrombus formation and enhance development or progression of autoimmune processes. Low concentrations of ATP diminish LPS-induced inflammatory state of APS monocytes which might be a potential mechanism which regulates inflammatory state of the cells. PMID:25785264

  18. LPS impairs oxygen utilization in epithelia by triggering degradation of the mitochondrial enzyme Alcat1.

    PubMed

    Zou, Chunbin; Synan, Matthew J; Li, Jin; Xiong, Sheng; Manni, Michelle L; Liu, Yuan; Chen, Bill B; Zhao, Yutong; Shiva, Sruti; Tyurina, Yulia Y; Jiang, Jianfei; Lee, Janet S; Das, Sudipta; Ray, Anuradha; Ray, Prabir; Kagan, Valerian E; Mallampalli, Rama K

    2016-01-01

    Cardiolipin (also known as PDL6) is an indispensable lipid required for mitochondrial respiration that is generated through de novo synthesis and remodeling. Here, the cardiolipin remodeling enzyme, acyl-CoA:lysocardiolipin-acyltransferase-1 (Alcat1; SwissProt ID, Q6UWP7) is destabilized in epithelia by lipopolysaccharide (LPS) impairing mitochondrial function. Exposure to LPS selectively decreased levels of carbon 20 (C20)-containing cardiolipin molecular species, whereas the content of C18 or C16 species was not significantly altered, consistent with decreased levels of Alcat1. Alcat1 is a labile protein that is lysosomally degraded by the ubiquitin E3 ligase Skp-Cullin-F-box containing the Fbxo28 subunit (SCF-Fbxo28) that targets Alcat1 for monoubiquitylation at residue K183. Interestingly, K183 is also an acetylation-acceptor site, and acetylation conferred stability to the enzyme. Histone deacetylase 2 (HDAC2) interacted with Alcat1, and expression of a plasmid encoding HDAC2 or treatment of cells with LPS deacetylated and destabilized Alcat1, whereas treatment of cells with a pan-HDAC inhibitor increased Alcat1 levels. Alcat1 degradation was partially abrogated in LPS-treated cells that had been silenced for HDAC2 or treated with MLN4924, an inhibitor of Cullin-RING E3 ubiquitin ligases. Thus, LPS increases HDAC2-mediated Alcat1 deacetylation and facilitates SCF-Fbxo28-mediated disposal of Alcat1, thus impairing mitochondrial integrity. PMID:26604221

  19. Acute systemic LPS-mediated inflammation induces lasting changes in mouse cortical neuromodulation and behavior.

    PubMed

    Ming, Z; Sawicki, G; Bekar, L K

    2015-03-17

    Systemic lipopolysaccharide (LPS) is widely used to induce a neuroinflammatory response that is associated with short-term 'sickness'-behavior that can include fever, loss of activity, loss of appetite, impaired cognition, anxiety and depression. If large enough or left unchecked, this neuroinflammatory response can become self-perpetuating and lead to long-term neurodegenerative processes. In this study, we assess the longer-term effects of a single systemic LPS injection on electrophysiological neuromodulator effects and basic behavioral analysis in mice. Five months after LPS injection, we find a mild reduction in cortical inhibition and altered temporal dynamics of acetylcholine but not norepinephrine or serotonin neuromodulator effects. Consistent with electrophysiological findings, LPS treated mice showed a deficit in memory performance in the novel object recognition test with no effect on measures of anxiety or despair as measured in the open field test and tail suspension test, respectively. Furthermore, LPS-treated mice showed an increase in acetylcholinesterase activity. As increased acetylcholinesterase activity is associated with reduced acetylcholine signaling and impaired cognitive ability, these studies demonstrate the potential for a single inflammatory event to initiate processes that may lead to long-term neurodegeneration. PMID:25650524

  20. Enforced expression of miR-125b attenuates LPS-induced acute lung injury.

    PubMed

    Guo, Zhongliang; Gu, Yutong; Wang, Chunhong; Zhang, Jie; Shan, Shan; Gu, Xia; Wang, Kailing; Han, Yang; Ren, Tao

    2014-11-01

    The acute respiratory distress syndrome (ARDS), a severe form of 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. Recent evidence implicated a potential role of miR-125b in development of ALI. Here we evaluated the miR-125b-based strategy in treatment of ARDS using the murine model of lipopolysaccharide (LPS)-induced ALI. We found that up-regulation of miR-125b expression maintained the body weight and survival of ALI mice, and significantly reduced LPS-induced pulmonary inflammation as reflected by reductions in total cell and neutrophil counts, proinflammatory cytokines, as well as chemokines in BAL fluid. Further, enforced expression of miR-125b resulted in remarkable reversal of LPS-induced increases in lung permeability as assessed by reductions in total protein, albumin and IgM in BAL fluid, and ameliorated the histopathology changes of lung in LPS-induced ALI mice. Of interest, serum miR-125b expression was also decreased and inversely correlated with the disease severity in patients with ARDS. Our findings strongly demonstrated that enforced expression of miR-125b could effectively ameliorate the LPS-induced ALI, suggesting a potential application for miR-125b-based therapy to treat clinical ARDS. PMID:25004393

  1. Catalpol protects dopaminergic neurons from LPS-induced neurotoxicity in mesencephalic neuron-glia cultures.

    PubMed

    Tian, Yuan-Yuan; An, Li-Jia; Jiang, Lan; Duan, Yan-Long; Chen, Jun; Jiang, Bo

    2006-12-23

    Inflammation plays an important role in the pathogenesis of Parkinson's disease (PD). Microglia, the resident immune cells in the central nervous system, are pivotal in the inflammatory reaction. Activated microglia can induce expression of inducible nitric-oxide synthase (iNOS) and release significant amounts of nitric oxide (NO) and TNF-alpha, which can damage the dopaminergic neurons. Catalpol, an iridoid glycoside, contained richly in the roots of Rehmannia glutinosa, was found to be neuroprotective in gerbils subjected to transient global cerebral ischemia. But the effect of catalpol on inflammation-mediated neurodegeneration has not been examined. In this study, microglia in mesencephalic neuron-glia cultures were activated with lipopolysaccharide (LPS) and the aim of the study was to examine whether catalpol could protect dopaminergic neurons from LPS-induced neurotoxicity. The results showed that catalpol significantly reduced the release of reactive oxygen species (ROS), TNF-alpha and NO after LPS-induced microglial activation. Further, catalpol attenuated LPS-induced the expression of iNOS. As determined by immunocytochemical analysis, pretreatment by catalpol dose-dependently protected dopaminergic neurons against LPS-induced neurotoxicity. These results suggest that catalpol exerts its protective effect on dopaminergic neurons by inhibiting microglial activation and reducing the production of proinflammatory factors. Thus, catalpol may possess therapeutic potential against inflammation-related neurodegenerative diseases. PMID:17049947

  2. Resistance of LPS-activated bone marrow derived macrophages to apoptosis mediated by dexamethasone

    PubMed Central

    Haim, Yasmin Ohana; Unger, Naamit Deshet; Souroujon, Miriam C.; Mittelman, Moshe; Neumann, Drorit

    2014-01-01

    Glucocorticoids (GC) display pleiotropic effects on the immune system. Macrophages are a major target for GC action. Here we show that dexamethasone (DEX), a synthetic GC, decreased viability of naïve bone marrow-derived macrophages (BMDM), involving an apoptotic mechanism. Administration of DEX together with lipopolysaccharide (LPS) protected BMDM against DEX-mediated cell death, suggesting that activated BMDM respond to DEX differently than naïve BMDM. An insight to the molecular basis of LPS