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Hashimoto M, Ozono M, Furuyashiki M, Baba R, Hashiguchi S, Suda Y, Fukase K, Fujimoto Y. Characterization of a Novel d-Glycero-d-talo-oct-2-ulosonic acid-substituted Lipid A Moiety in the Lipopolysaccharide Produced by the Acetic Acid Bacterium Acetobacter pasteurianus NBRC 3283. J Biol Chem 2016; 291:21184-21194. [PMID: 27539854 DOI: 10.1074/jbc.m116.751271] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Indexed: 01/17/2023] Open
Abstract
Acetobacter pasteurianus is an aerobic Gram-negative rod that is used in the fermentation process used to produce the traditional Japanese black rice vinegar kurozu. Previously, we found that a hydrophobic fraction derived from kurozu stimulates Toll-like receptors to produce cytokines. LPSs, particularly LPS from A. pasteurianus, are strong candidates for the immunostimulatory component of kurozu. The LPS of A. pasteurianus remains stable in acidic conditions during the 2 years of the abovementioned fermentation process. Thus, we hypothesized that its stability results from its structure. In this study, we isolated the LPS produced by A. pasteurianus NBRC 3283 bacterial cells and characterized the structure of its lipid A component. The lipid A moiety was obtained by standard weak acid hydrolysis of the LPS. However, the hydrolysis was incomplete because a certain proportion of the LPS contained acid-stable d-glycero-d-talo-oct-2-ulosonic acid (Ko) residues instead of the acid-labile 3-deoxy-d-manno-oct-2-ulosonic acid residues that are normally found in typical LPS. Even so, we obtained a Ko-substituted lipid A with a novel sugar backbone, α-Man(1-4)[α-Ko(2-6)]β-GlcN3N(1-6)α-GlcN(1-1)α-GlcA. Its reducing end GlcN(1-1)GlcA bond was also found to be quite acid-stable. Six fatty acids were attached to the backbone. Both the whole LPS and the lipid A moiety induced TNF-α production in murine cells via Toll-like receptor 4, although their activity was weaker than those of Escherichia coli LPS and lipid A. These results suggest that the structurally atypical A. pasteurianus lipid A found in this study remains stable and, hence, retains its immunostimulatory activity during acetic acid fermentation.
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Affiliation(s)
- Masahito Hashimoto
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan,
| | - Mami Ozono
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Maiko Furuyashiki
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Risako Baba
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Shuhei Hashiguchi
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Yasuo Suda
- From the Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Koichi Fukase
- the Department of Chemistry, Graduate School of Science, Osaka University, Osaka 560-0043, Japan, and
| | - Yukari Fujimoto
- the Faculty of Science and Technology, Keio University, Kanagawa 223-8522, Japan
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Comalada M, Xaus J, Valledor AF, López-López C, Pennington DJ, Celada A. PKC epsilon is involved in JNK activation that mediates LPS-induced TNF-alpha, which induces apoptosis in macrophages. Am J Physiol Cell Physiol 2003; 285:C1235-45. [PMID: 12867362 DOI: 10.1152/ajpcell.00228.2003] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Lipopolysaccharide (LPS) is a powerful stimulator of macrophages and induces apoptosis in these cells. Using primary cultures of bone marrow-derived macrophages, we found that the autocrine production of tumor necrosis factor-alpha (TNF-alpha) has a major function in LPS-induced apoptosis. LPS activates PKC and regulates the different mitogen-activated protein kinases (MAPK). We aimed to determine its involvement either in the secretion of TNF-alpha or in the induction of apoptosis. Using specific inhibitors and mice with the gene for PKCepsilon disrupted, we found that LPS-induced TNF-alpha-dependent apoptosis is mostly mediated by PKCepsilon, which is not directly involved in the signaling mechanism of apoptosis but rather in the process of TNF-alpha secretion. In our cell model, all three MAPKs were involved in the regulation of TNF-alpha secretion, but at different levels. JNK mainly regulates TNF-alpha transcription and apoptosis, whereas ERK and p38 contribute to the regulation of TNF-alpha production, probably through posttranscriptional mechanisms. Only JNK activity is mediated by PKCepsilon in response to LPS and so plays a major role in TNF-alpha secretion and LPS-induced apoptosis. We demonstrated in macrophages that LPS involving PKCepsilon regulates JNK activity and produces TNF-alpha, which induces apoptosis.
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Affiliation(s)
- Mònica Comalada
- Macrophage Biology Group, Biomedical Research Institute of Barcelona-Science Park, University of Barcelona, Josep Samitier 1-5, 08028 Barcelona, Spain
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