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Bacterial Supernatant (bacterial + supernatant)
Selected AbstractsCharacterization of epithelial IL-8 response to inflammatory bowel disease mucosal E. coli and its inhibition by mesalamine,INFLAMMATORY BOWEL DISEASES, Issue 2 2008Sreedhar Subramanian MD Abstract Background: Mucosally adherent E. coli are found in inflammatory bowel disease (IBD) and colon cancer. They promote release of the proinflammatory cytokine interleukin-8 (IL-8). We explored mechanisms for this release and its inhibition by drugs. Methods: IL-8 release from colon epithelial cells in response to mucosal E. coli isolates from IBD, colon cancer, and controls was characterized at the cellular and molecular level. Results: IL-8 response of HT29 cells was greater with Crohn's disease (689 ± 298 [mean ± SD] pg IL-8/mL at 4 hours, n = 7) and colon cancer isolates (532 ± 415 pg/mL, n = 14) than with ulcerative colitis (236 ± 58 pg/mL, n = 6) or control isolates (236 ± 100 pg/mL, n = 6, P < 0.0001). Bacterial supernatants contained shed flagellin that triggered IL-8 release. For whole bacteria the IL-8 response to E. coli that agglutinate red blood cells (548 ± 428 pg IL-8/mL, n = 16), a function that correlates with epithelial invasion, was greater than for nonhemagglutinators (281 ± 253 pg/mL, n = 17; P < 0.0001). This was particularly marked among E. coli that, although flagellate, could not release IL-8 from TLR5-transfected HEK293 cells. IL-8 release was mediated by extracellular-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and inhibited by mesalamine, but not hydrocortisone, at therapeutic concentrations. Conclusions: Mucosa-associated E. coli shed flagellin that elicits epithelial IL-8 release but this may only become relevant when the mucosal barrier is weakened to expose basolateral TLR5. Adherent and invasive IBD and colon cancer E. coli isolates also elicit a flagellin-independent IL-8 response that may be relevant when the mucosal barrier is intact. The IL-8 release is MAPK-dependent and inhibited by mesalamine. (Inflamm Bowel Dis 2007) [source] Potential of bacterial indoleacetic acid to induce adventitious shoots in plant tissue cultureLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2007B. Ali Abstract Aims:, The main aim of this study was to investigate the possible role of indoleacetic acid (IAA) from bacteria to induce in vitro adventitious shoots in internodal explants of Brassica oleracea L. Methods and Results:, Culture supernatant of Halomonas sp. RE1 and Halomonas sp. HT1 that contain 21 and 40 ,g ml,1 IAA, respectively, was used to supplement Murashige and Skoog (MS) medium. Two combinations that were supplemented with bacterial supernatant (BS) are MS + BS and MS + BS + 10%CW (coconut water) while basal MS medium was used as control. The amounts of BS used in this experiment were 50, 100, 150 and 200 ,l in 5 ml MS medium in each combination. In vitro -grown internodal explants of B. oleracea were inoculated on these media combinations and incubated in a growth chamber at 25 ± 1°C and exposed to 16-h cool fluorescent light. After 5,6 weeks of incubation adventitious shoot induction was observed in all treatments that were supplemented with BS as compared with the controls where very low response was observed. The frequency of shoot induction was high in media that were supplemented with 10%CW in the presence of bacterial auxin. Conclusions:, It was concluded that IAA of microbial origin has the potential to induce adventitious shoots in internodal explants. Significance and Impact of the Study:, IAA from bacteria can be effectively used in plant tissue culture; especially a combination of MS + BS + 10%CW is very cost-effective as compared with synthetic phytohormones for in vitro studies. [source] Very severe thrombocytopenia and fragmentation hemolysis mimicking thrombotic thrombocytopenic purpura associated with a giant intracardiac vegetation infected with Staphylococcus epidermidis: Role of monocyte procoagulant activity induced by bacterial supernatantAMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2007Kathleen Selleng Abstract The pathogenesis of very severe thrombocytopenia in bacterial endocarditis is uncertain. We report a 50-year-old male with platelet counts < 10 × 109/l and fragmentation hemolysis complicating Staphyloccoccus epidermidis pacemaker endocarditis with a giant vegetation. Antibiotics, corticosteroids, high-dose intravenous gammaglobulin, and plasmapheresis (for initially-suspected thrombotic thrombocytopenic purpura) failed to produce significant platelet count increase. However, therapeutic-dose heparin anticoagulation was associated with a platelet count increase from <10 to ,40 × 109/l, with parallel reduction in thrombin-antithrombin complexes (from 8.9 to 3.5 ,g/l), facilitating surgical intervention. The thrombocytopenia promptly resolved following surgical removal of the vegetation. Culture supernatant from S. epidermidis isolated from the patient's blood induced monocytes to express procoagulant activity (assessed by factor Xa generation) equivalent to lipopolysaccharide (1 ,g/ml), with half-maximal activation seen with culture supernatant diluted to 1:12,800. These data are consistent with previous animal models of endocarditis demonstrating staphylococci-induced procoagulant changes in monocytes. This case demonstrates that heparin anticoagulation can be therapeutic in infective endocarditis-associated severe thrombocytopenia in a non-bleeding patient, and that such therapy may ameliorate the platelet count enough to permit surgical intervention. Am. J. Hematol 2007. © 2006 Wiley-Liss, Inc. [source] Differential modulation of innate immune cell functions by the Burkholderia cepacia complex: Burkholderia cenocepacia but not Burkholderia multivorans disrupts maturation and induces necrosis in human dendritic cellsCELLULAR MICROBIOLOGY, Issue 10 2008Kelly L. MacDonald Summary Burkholderia cepacia complex (BCC) bacteria cause pulmonary infections that can evolve into fatal overwhelming septicemia in chronic granulomatous disease or cystic fibrosis patients. Burkholderia cenocepacia and Burkholderia multivorans are responsible for the majority of BCC infections in cystic fibrosis patients, but B. cenocepacia is generally associated with a poorer prognosis than B. multivorans. The present study investigated whether these pathogens could modulate the normal functions of primary human monocyte-derived dendritic cells (DCs), important phagocytic cells that act as critical orchestrators of the immune response. Effects of the bacteria on maturation of DCs were determined using flow cytometry. DCs co-incubated for 24 h with B. cenocepacia, but not B. multivorans, had reduced expression of costimulatory molecules when compared with standard BCC lipopolysaccharide-matured DCs. B. cenocepacia, but not B. multivorans, also induced necrosis in DCs after 24 h, as determined by annexin V and propidium iodide staining. DC necrosis only occurred after phagocytosis of live B. cenocepacia; DCs exposed to heat-killed bacteria, bacterial supernatant or those pre-treated with cytochalasin D then exposed to live bacteria remained viable. The ability of B. cenocepacia to interfere with normal DC maturation and induce necrosis may contribute to its pathogenicity in susceptible hosts. [source] Analysis of S -adenosylmethionine and related sulfur metabolites in bacterial isolates of Pseudomonas aeruginosa (BAA-47) by liquid chromatography/electrospray ionization coupled to a hybrid linear quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 21 2009Tommaso R. I. Cataldi A comprehensive and highly selective method for detecting in bacterial supernatants a modified sulfur nucleoside, S -adenosyl-L-methionine (SAM), and its metabolites, i.e., S -adenosylhomocysteine (SAH), adenosine (Ado), 5,-deoxy-5,-methylthioadenosine (MTA), adenine (Ade), S -adenosyl-methioninamine (dcSAM), homocysteine (Hcy) and methionine (Met), was developed. The method is based on reversed-phase liquid chromatography with positive electrospray ionization (ESI+) coupled to a hybrid linear quadrupole ion trap (LTQ) and 7-T Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). A gradient elution was employed with a binary solvent of 0.05,M ammonium formate at pH 4 and acetonitrile. The assay involves a simultaneous cleanup of cell-free bacterial broths by solid-phase extraction and trace enrichment of metabolites with a 50-fold concentration factor by using immobilized phenylboronic and anion-exchange cartridges. While the quantitative determination of SAM was performed using stable-isotope-labeled SAM-d3 as an internal standard, in the case of Met and Ade, Met- 13C and Ade- 15N2 were employed as isotope-labeled internal standards, respectively. This method enabled the identification of SAM and its metabolites in cell-free culture of Pseudomonasaeruginosa grown in Davis minimal broth (formulation without sulphur organic compounds), with routine sub-ppm mass accuracies (,0.27,±,0.68,ppm). The resulting contents of SCSS -SAM, SS -dcSAM, MTA, Ado and Met in the free-cell supernatant of P. aeruginosa was 56.4,±,2.1,nM, 32.2,±,2.2,nM, 0.91,±,0.10,nM, 19.6,±,1.2,nM and 1.93,±,0.02,µM (mean,±,SD, n,=,4 extractions), respectively. We report also the baseline separation (Rs ,1.5) of both diastereoisomeric forms of SAM (SCSS and SCRS) and dcSAM (SS and RS), which can be very useful to establish the relationship between the biologically active versus the inactive species, SCSS/SCRS and SS/RS of SAM and dcSAM, respectively. An additional confirmation of SAM-related metabolites was accomplished by a systematic study of their MS/MS spectra. Copyright © 2009 John Wiley & Sons, Ltd. [source] Trefoil factor 3 is induced during degenerative and inflammatory joint disease, activates matrix metalloproteinases, and enhances apoptosis of articular cartilage chondrocytesARTHRITIS & RHEUMATISM, Issue 3 2010Sophie Rösler Objective Trefoil factor 3 (TFF3, also known as intestinal trefoil factor) is a member of a family of protease-resistant peptides containing a highly conserved motif with 6 cysteine residues. Recent studies have shown that TFF3 is expressed in injured cornea, where it plays a role in corneal wound healing, but not in healthy cornea. Since cartilage and cornea have similar matrix properties, we undertook the present study to investigate whether TFF3 could induce anabolic functions in diseased articular cartilage. Methods We used reverse transcriptase,polymerase chain reaction, Western blot analysis, and immunohistochemistry to measure the expression of TFF3 in healthy articular cartilage, osteoarthritis (OA),affected articular cartilage, and septic arthritis,affected articular cartilage and to assess the effects of cytokines, bacterial products, and bacterial supernatants on TFF3 production. The effects of TFF3 on matrix metalloproteinase (MMP) production were measured by enzyme-linked immunosorbent assay, and effects on chondrocyte apoptosis were studied by caspase assay and annexin V assay. Results Trefoil factors were not expressed in healthy human articular cartilage, but expression of TFF3 was highly up-regulated in the cartilage of patients with OA. These findings were confirmed in animal models of OA and septic arthritis, as well as in tumor necrosis factor ,, and interleukin-1,,treated primary human articular chondrocytes, revealing induction of Tff3/TFF3 under inflammatory conditions. Application of the recombinant TFF3 protein to cultured chondrocytes resulted in increased production of cartilage-degrading MMPs and increased chondrocyte apoptosis. Conclusion In this study using articular cartilage as a model, we demonstrated that TFF3 supports catabolic functions in diseased articular cartilage. These findings widen our knowledge of the functional spectrum of TFF peptides and demonstrate that TFF3 is a multifunctional trefoil factor with the ability to link inflammation with tissue remodeling processes in articular cartilage. Moreover, our data suggest that TFF3 is a factor in the pathogenesis of OA and septic arthritis. [source] | |||||||||||||