For Publishers
DiscoveryMetadataPeer reviewHostingPublishing
For Researchers
JoinPublishReviewCollect
Register
Blog
About
Search
Advanced search
My ScienceOpen
Search
For Publishers
For Researchers
Blog
About
46
views
36
references
 Top references
cited by
22
    
0 reviews
 Review
0
comments
 Comment
0
recommends
+1 Recommend
0 collections
    0
    shares
      496
      similar
       All similar
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Role of Sphingomyelinase in Infectious Diseases Caused by Bacillus cereus

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Bacillus cereus ( B. cereus) is a pathogen in opportunistic infections. Here we show that Bacillus cereus sphingomyelinase ( Bc-SMase) is a virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew in vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant of the ATCC strain carrying a recombinant plasmid containing the Bc-SMase gene grew in vivo, but that with the gene for E53A, which has little enzymatic activity, did not. Administration of an anti- Bc-SMase antibody and immunization against Bc-SMase prevented death caused by the clinical isolates, showing that Bc-SMase plays an important role in the diseases caused by B. cereus. Treatment of mouse macrophages with Bc-SMase resulted in a reduction in the generation of H 2O 2 and phagocytosis of macrophages induced by peptidoglycan (PGN), but no effect on the release of TNF-α and little release of LDH under our experimental conditions. Confocal laser microscopy showed that the treatment of mouse macrophages with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that the cells treated with Bc-SMase exhibited a reduction in membrane fluidity. The results suggest that Bc-SMase is essential for the hydrolysis of SM in membranes, leading to a reduction in phagocytosis.

          Related collections

          Most cited references36

          • Record: found
          • Abstract: found
          • Article: not found

          Plasma ceramide and lysophosphatidylcholine inversely correlate with mortality in sepsis patients.

          Gregor Rothe, F Audebert, Edward Frohlich … (2003)
          Recent data indicate that ceramide (Cer) and lysophosphatidylcholine (LPC) regulate immune cell functions. Since these bioactive lipids are generated in blood plasma by inflammatory lipases, we hypothesized that they may be involved in the process of acute systemic sepsis. In order to provide support for this hypothesis, we analyzed the plasma levels of Cer and LPC by quantitative tandem mass spectrometry in 102 sepsis patients starting with the day at which the sepsis criteria were fulfilled for the first time, as well as on day 4 and day 11. The values were compared with 56 healthy controls and correlated with sepsis-related mortality within 30 days of study entry. Most Cer species were increased in sepsis patients, while all LPC species were markedly decreased. In addition, we determined the molar ratios with their precursor molecules sphingomyelin (SPM) and phosphatidylcholine (PC), which reflect the enzymatic reactions responsible for their formation. Species-specific as well as total Cer-SPM ratios were increased, whereas LPC-PC ratios were decreased in sepsis patients. The increased Cer-SPM ratios as well as the decreased LPC-PC ratios showed a strong predictive power for sepsis-related mortality. Together with existing data from in vitro experiments and animal models, the results provide the first ex vivo indication for the role of Cer and lysophospholipids in systemic inflammation in humans.
          Article 0 comments Cited 109 times – based on 0 reviews     Review now
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The PlcR Virulence Regulon of Bacillus cereus

            Michel Gohar, Karoline Faegri, Stéphane Perchat … (2008)
            PlcR is a Bacillus cereus transcriptional regulator, which activates gene expression by binding to a nucleotidic sequence called the ‘PlcR box’. To build a list of all genes included in the PlcR regulon, a consensus sequence was identified by directed mutagenesis. The reference strain ATCC14579 sequenced genome was searched for occurrences of this consensus sequence to produce a virtual regulon. PlcR control of these genes was confirmed by comparing gene expression in the reference strain and its isogenic Δ-plcR strain using DNA microarrays, lacZ fusions and proteomics methods. The resulting list included 45 genes controlled by 28 PlcR boxes. Forty of the PlcR controlled proteins were exported, of which 22 were secreted in the extracellular medium and 18 were bound or attached to cell wall structures (membrane or peptidoglycan layer). The functions of these proteins were related to food supply (phospholipases, proteases, toxins), cell protection (bacteriocins, toxins, transporters, cell wall biogenesis) and environment-sensing (two-component sensors, chemotaxis proteins, GGDEF family regulators). Four genes coded for cytoplasmic regulators. The PlcR regulon appears to integrate a large range of environmental signals, including food deprivation and self cell-density, and regulate the transcription of genes designed to overcome obstacles that hinder B. cereus growth within the host: food supply, host barriers, host immune defenses, and competition with other bacterial species. PlcR appears to be a key component in the efficient adaptation of B. cereus to its host environment.
            Article 0 comments Cited 102 times – based on 0 reviews     Review now
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Effects of ceramide and other simple sphingolipids on membrane lateral structure.

              Alicia Alonso, Félix M. Goñi (2008)
              The available data concerning the ability of ceramide and other simple sphingolipids to segregate laterally into rigid, gel-like domains in a fluid bilayer has been reviewed. Ceramides give rise to rigid ceramide-enriched domains when their N-acyl chain is longer than C12. The high melting temperature of hydrated ceramides, revealing a tight intermolecular interaction, is probably responsible for their lateral segregation. Ceramides compete with cholesterol for the formation of domains with lipids such as sphingomyelin or saturated phosphatidylcholines; under these conditions displacement of cholesterol by ceramide involves a transition from a liquid-ordered to a gel-like phase in the domains involved. When ceramide is generated in situ by a sphingomyelinase, instead of being premixed with the other lipids, gel-like domain formation occurs as well, although the topology of the domains may not be the same, the enzyme causing clustering of domains that is not detected with premixed ceramide. Ceramide-1-phosphate is not likely to form domains in fluid bilayers, and the same is true of sphingosine and of sphingosine-1-phosphate. However, sphingosine does rigidify pre-existing gel domains in mixed bilayers.
              Article 0 comments Cited 46 times – based on 0 reviews     Review now
                Bookmark
                All references

                Author and article information

                Contributors
                : Role: Editor
                Journal
                Journal ID (nlm-ta): PLoS One
                Journal ID (iso-abbrev): PLoS ONE
                Journal ID (publisher-id): plos
                Journal ID (pmc): plosone
                Title: PLoS ONE
                Publisher: Public Library of Science (San Francisco, USA )
                ISSN (Electronic): 1932-6203
                Publication date Collection: 2012
                Publication date (Electronic): 6 June 2012
                Volume: 7
                Issue: 6
                Electronic Location Identifier: e38054
                Affiliations
                [1 ]Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, Japan
                [2 ]Institute for Health Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, Japan
                [3 ]Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama Kita-ku, Kyoto, Japan
                [4 ]School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
                [5 ]School of Medicine, Jichi Medical University, Shimono-city, Tochigi, Japan
                The Scripps Research Institute, United States of America
                Author notes

                Conceived and designed the experiments: MO. Performed the experiments: MO MH MT YO SS RK AF HT. Analyzed the data: MO MN SO TS SH YH JS. Contributed reagents/materials/analysis tools: MO HT. Wrote the paper: MO JS.

                Article
                Publisher ID: PONE-D-12-02609
                DOI: 10.1371/journal.pone.0038054
                PMC ID: 3368938
                PubMed ID: 22701599
                SO-VID: e4149f66-1d20-4fff-bcb3-a92b3989584b
                Copyright © Oda et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
                History
                Date received : 28 January 2012
                Date accepted : 2 May 2012
                Page count
                Pages: 11
                Categories
                Subject: Research Article
                Subject: Biology
                Subject: Biochemistry
                Subject: Lipids
                Subject: Sphingolipids
                Subject: Proteins
                Subject: Protein Structure
                Subject: Microbiology
                Subject: Microbial Growth and Development
                Subject: Microbial Mutation
                Subject: Pathogenesis
                Subject: Medicine
                Subject: Clinical Immunology
                Subject: Immunity
                Subject: Vaccination
                Subject: Vaccines
                Subject: Infectious Diseases
                Subject: Infectious Disease Control

                ScienceOpen disciplines: Uncategorized
                Data availability:
                ScienceOpen disciplines: Uncategorized

                Comments

                Comment on this article

                scite_

                Similar content496

                See all similar

                Cited by21

                See all cited by

                Most referenced authors877

                See all reference authors