Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pyrene and several derivatives of pyrene are used to investigate photo-induced kinetic processes in whole cells and membranes extracted from Escherichia coli. A mutant of E. coli was used which, under appropriate growth conditions, produced a complete or incomplete lipopolysaccharide in the outer membrane. The pyrene derivatives used were: pyrene sulfonic acid, pyrene butyric acid and the ester of pyrene butyric acid and 10-hydroxydecanoic acid. The pyrene chromophore was excited by the ultraviolet pulse from a Q switch, frequency-doubled, ruby laser. The lifetimes of the pyrene fluorescence in the presence of the quenchers O2, thallous ion (T1+), I-and CH3NO2 were measured and tabulated as second order rate constants. For the most part the quenching rate constants were much lower than the corresponding values observed in simple nonviscous solution, e.g. ethanol. This is interpreted as being due to the location of the probe within the membrane. The membrane inhibits the movement of the quenchers to the excited state. Cell membranes containing complete lipopolysaccharide showed significantly lower quenching rates for the probes pyrene and pyrene sulfonic acid than cell membranes with incomplete lipopolysaccharide. From an amalysis of the kinetic data it is suggested that pyrene and pyrene sulfonic acid are located near and under lipopolysaccharide and close to membrane proteins. On the other hand, no effect of lipopolysaccharide composition was observed for the probes pyrene butyric acid and pyrene butyroyl decanoic acid. This may suggest that these probes are located primarily in the lipid part of the membrane. A simple model for the outer membrane of E. coli is suggested that accounts for the observed laser-induced kinetic processes.
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PMID:Kinetic processes in Escherichia coli membranes and cells. A laser photolysis study using derivatives of pyrene. 76 28

Sodium butyrate, lithium acetate, and hydroxyurea given to serum-free culture of RSP-2 X P3 cells notably reduced the rate of cell proliferation but markedly enhanced the production of such a colony-stimulating factor (CSF) as one that stimulated predominantly neutrophilic granulocyte colony formation in mouse bone marrow cell cultures (Tsuneoka and Shikita, 1984). On the other hand, the production of macrophage CSF was not increased in the butyrate-treated RSP-2 X 3 cells. Butyrate also failed to enhance either macrophage CSF or neutrophil CSF production in L X P3 (mouse fibroblast line), Huk-1 X P3 (human kidney cell line) or Nil2C2 (hamster embryo fibroblast line) cells. The addition of bacterial lipopolysaccharide (LPS) together with butyrate resulted in further pronounced enhancement of the neutrophil CSF production in RSP-2 X P3 cells, while the cells did not develop tolerance against LPS upon repeated challenge. The yield of neutrophil CSF was thus increased by about 45 times that of the control during continuous culture for 12 days. Large-scale culture of the cells under these conditions must be an excellent source of a CSF for neutrophil granulocytes.
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PMID:A colony-stimulating factor for neutrophil granulocytes: a marked increase of its production by the addition of sodium butyrate and lipopolysaccharide in serum-free culture of RSP-2 X P3 cells. 387 31

Mouse monocytic Mm-A cells are a highly leukemogenic variant line of the monocytic and non-leukemogenic cell line Mm-1, which developed spontaneously from mouse myeloid leukemia M1 cells. Studies were made on whether Mm-A cells could be induced to differentiate further by agents that were effective for inducing differentiation of the parent M1 cells and other leukemic cells. Of the agents tested, butyrate, conditioned medium from concanavalin A-stimulated spleen cells, lipopolysaccharide (LPS) and N6,O2-dibutyryl adenosine 3'5'-cyclic-monophosphate (dbcAMP) significantly stimulated the lysozyme activity of Mm-A cells, which is one of the most characteristic biochemical markers of monocytes and macrophages. Butyrate was the most effective agent for increasing lysozyme production by Mm-A cells; culture with 0.5mM butyrate for 3 days increased lysozyme production by Mm-A cells about 50-fold. Inducers of M1 cell differentiation such as dexamethasone, 1 alpha,25-dihydroxyvitamin D3, arginase, and proteinous inducer did not increase the lysozyme activity. Butyrate also induced NBT reduction and stimulated other differentiation-associated functions, such as expressions of Fc receptors on the cell surface, immune phagocytosis and production of inducer for M1 cell differentiation. Its effect in stimulating differentiation of Mm-A cells was synergistic with that of dbcAMP or LPS. Incubation with butyrate inhibited the proliferation of Mm-A cells, about 0.3mM butyrate causing 50% inhibition. These results indicate that monocytic, leukemogenic Mm-A cells can be induced to differentiate further by butyrate and that the inducers of differentiation of Mm-A cells are markedly different from those of the parent myeloblastic M1 cells.
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PMID:Induction of differentiation of cultured mouse monocytic leukemia cells (Mm-A) by inducers different from those of parent myeloblastic leukemia cells (M1). 393 26

The induction of partial maturation in an in vitro derived Abelson virus-transformed murine lymphoid cell subline (ABC-1/AT1) is described. Pre-B (cytoplasmic, mu chain-positive) lymphocytes were induced from presumptive B cell precursors by prostaglandin E1, butyric acid, lipopolysaccharide and interferon. Maturation was independent of alterations in cellular growth rate and could be achieved in the absence of cell division. The AT1 subline was found to be restricted to the expression of a single light chain type (lambda) indicating a possible B cell lineage-committed precursor as the target for viral transformation.
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PMID:Partial maturation and light chain restriction of Abelson virus-transformed B cell precursors. 678 33

A sensitive method for the quantitative determination of lipid A, the covalently bound hydrophobic component of lipopolysaccharides (endotoxins), has been developed. The determination of lipid A was based on the quantitative measurement of beta-hydroxymyristic acid and beta-hydroxylauric acid by reversed-phase HPLC. beta-Hydroxy acids were liberated from ester and amide linkages in endotoxins by acid catalyzed methanolysis. The resulting methyl esters were derivatized with 9-anthracene-carboxyl chloride, 9-fluorene-carboxyl chloride and 4-(1-pyrenyl)butyric acid chloride and quantified with a fluorescence detector. The effectiveness of the three derivatizing agents was compared. As internal standards-beta-hydroxytridecanoic acid [beta-OH(13:0)] and beta-hydroxypentadecanoic acid [beta-OH(15:0)] ethyl esters were used. The limits of detection of beta-hydroxymyristic acid were 0.5 pg for the 9-anthroyl and 2 pg for the fluorenoyl and 4-(1-pyrenyl)butyroyl ester per sample (signal-to-noise ratio of 3). The detection limits of lipopolysaccharide from a smooth strain (Escherichia coli 0111:B4) was 20 pg, while that from two rough strains (E. coli Nissle 1917 and Salmonella typhimurium SL 1181) was 5 pg per sample after methanolysis and derivatization with 9-anthroyl chloride.
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PMID:Lipopolysaccharide determination by reversed-phase high-performance liquid chromatography after fluorescence labeling. 758 48

Butyrate at concentrations of 200-600 microM markedly enhanced the in vitro antibody productions against sheep red blood cells (SRBC) in murine splenocytes. However, other saturated short-chain fatty acids, including acetate, propionate and valeric acid, and 4-carbon compounds such as butanol, acetoacetate and beta- and gamma-hydroxybutyrate had no such effects. The presence of butyrate in the early phase of the cell culture was crucial for enhancement of the response. Butyrate also augmented the antibody production in T-cell-depleted splenocytes supplemented with the culture supernatant of concanavalin A (Con A)-stimulated lymphocytes. Interleukin (IL)-2 secreted from splenocytes in response to SRBC was increased by adding butyrate to the culture, but IL-1 secretion was not affected. On the other hand, Con A or lipopolysaccharide-stimulated proliferation of splenocytes was partly depressed by the addition of butyrate, while Con A-induced IL-2 production was not effected. These findings suggest that butyrate may act on T and B cells to promote their differentiation during the process of antibody production.
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PMID:Butyrate enhances the in vitro anti-SRBC (sheep red blood cell) antibody responses in murine splenocytes. 786 24

Nonpathogenic, resident bacteria participate in the pathogenesis of inflammation in the small intestine, but the molecular messages produced by such bacteria are unknown. Inflammatory responses involve the recruitment of specific leukocyte subsets. We, therefore, hypothesized that butyrate, a normal bacterial metabolite, may modulate chemokine secretion by epithelial cells, by amplifying their response to proinflammatory signals. We studied the expression of the chemokine, macrophage inflammatory protein-2 (MIP-2) by the rat small intestinal epithelial cell line, IEC-6. Cells were stimulated with lipopolysaccharide or with interleukin 1beta (IL-1beta) and incubated with sodium butyrate. Acetylation of histones was examined in Triton X acetic acid-urea gels by PAGE. Unstimulated IEC-6 cells did not secrete MIP-2. However, lipopolysaccharide and IL-1beta induced MIP-2 expression. Butyrate enhanced MIP-2 secretion both in lipopolysaccharide-stimulated and IL-1beta-stimulated enterocytes; but butyrate alone did not induce MIP-2 expression. Butyrate increased the acetylation of histones extracted from the nuclei of IEC-6 cells. Furthermore, acetylation of histones (induced by trichostatin A, a specific inhibitor of histone deacetylase) enhanced MIP-2 expression by cells stimulated with IL-1beta. In conclusion, trichostatin A reproduced the effects of butyrate on MIP-2 secretion. Butyrate, therefore, increases MIP-2 secretion in stimulated cells by increasing histone acetylation. We speculate that butyrate carries information from bacteria to epithelial cells. Epithelial cells transduce this signal through histone deacetylase, modulating the secretion of chemokines.
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PMID:Macrophage inflammatory protein-2: chromosomal regulation in rat small intestinal epithelial cells. 929 1

Intestinal epithelial (Caco-2) cells secrete the chemokine, IL-8, after stimulation with IL-1beta, but not after lipopolysaccharide. Butyrate is a short chain fatty acid derived from the metabolism of intestinal contents by gut bacteria. Butyrate concentrations reflect, therefore, the bacterial microenvironment established within the intestine. We hypothesized that butyrate may alter the secretion of IL-8 by intestinal epithelial cells in response to stimulation by IL-1beta or lipopolysaccharide. Caco-2 cells were incubated in varying concentrations of sodium butyrate (0-20 mM) for 24 h before stimulation with lipopolysaccharide or IL-1beta. IL-8 secretion was measured over 24 h by ELISA. IL-8 mRNA accumulation was detected by Northern blots. Lipopolysaccharide induced the secretion of IL-8 only after Caco-2 cells cells had been cultured with sodium butyrate. Furthermore, butyrate significantly enhanced IL-8 secretion by cells stimulated with IL-1beta. Butyrate also increased IL-8 mRNA accumulation in stimulated Caco-2 cells. Intestinal epithelial cells can, therefore, be primed by butyrate to become activated by lipopolysaccharide and proinflammatory cytokines. This may represent a mechanism by which intestinal epithelial cells can regulate intestinal inflammation in response to changes in the intestinal milieu.
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PMID:Butyrate enhances interleukin (IL)-8 secretion by intestinal epithelial cells in response to IL-1beta and lipopolysaccharide. 943 17

We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3(+)-T-cell apoptosis followed by similar levels of both CD4(+)- and CD8(+)-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3(+) PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4(+) and CD8(+) cells.
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PMID:Lipopolysaccharide stimulates butyric acid-induced apoptosis in human peripheral blood mononuclear cells. 986 91

The effect of butyrate, a natural bacterial product of colonic bacterial flora, on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 murine macrophage cells was studied. Butyrate significantly reduced NO production in LPS-stimulated RAW cells. The inhibition was abolished by the removal of butyrate. Butyrate also inhibited the expression of inducible type NO synthase (iNOS) in LPS-stimulated RAW cells. Furthermore, butyrate prevented the activation of nuclear factor (NF)-kappaB through the stabilization of IkappaB-alpha and IkappaB-beta. Butyrate did not affect the phosphorylation of mitogen-activated protein (MAP) kinases by LPS. It was, therefore, suggested that butyrate down-regulated LPS-induced NO production in RAW cells through preventing the expression of iNOS, and that it was due to the inhibitory action of butyrate on the activation of NF-kappaB.
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PMID:The inhibitory action of butyrate on lipopolysaccharide-induced nitric oxide production in RAW 264.7 murine macrophage cells. 1105 79


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