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Rosas-Martínez M, Gutiérrez-Venegas G. Myricetin Inhibition of Peptidoglycan-Induced COX-2 Expression in H9c2 Cardiomyocytes. Prev Nutr Food Sci 2019; 24:202-209. [PMID: 31328126 PMCID: PMC6615347 DOI: 10.3746/pnf.2019.24.2.202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 05/23/2019] [Indexed: 11/06/2022] Open
Abstract
Peptidoglycan (PGN) is a cell wall constituent in dental plaque bacteria that triggers inflammatory responses. PGN binds Toll-like receptors, leading to increases in prostaglandin E2 and interleukin-1β, which play crucial roles in the inflammatory response and tissue destruction. Dental surgery can give plaque bacteria access to blood circulation, thereby creating a risk of septic inflammation of the endocardium. Plant-derived flavonoids have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we investigated the effects of flavonoid myricetin on expression of cyclooxygenase 2 (COX-2) in the H9c2 cells treated with PGN from Streptococcus sanguinis, a bacterial constituent of dental plaque associated with infective endocarditis. Myricetin exposure resulted in dose-dependent suppression of PGN-induced COX-2 expression, diminished phosphorylation of p38, extracellular signal regulated kinase 1/2, and c-Jun N-terminal kinase, and reduced IκB-α degradation, consistent with decreased COX-2 activity. In conclusion, the aforementioned results suggest that myricetin is useful for moderating the inflammatory response in infective endocarditis.
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Affiliation(s)
- Marisol Rosas-Martínez
- Biochemistry Laboratory of the Division of Graduate Studies and Research, Faculty of Dentistry, National Autonomous University of Mexico, Mexico 04510, Mexico
| | - Gloria Gutiérrez-Venegas
- Biochemistry Laboratory of the Division of Graduate Studies and Research, Faculty of Dentistry, National Autonomous University of Mexico, Mexico 04510, Mexico
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Uribe G, Villéger R, Bressollier P, Dillard RN, Worthley DL, Wang TC, Powell DW, Urdaci MC, Pinchuk IV. Lactobacillus rhamnosus GG increases cyclooxygenase-2 expression and prostaglandin E2 secretion in colonic myofibroblasts via a MyD88-dependent mechanism during homeostasis. Cell Microbiol 2018; 20:e12871. [PMID: 29920917 DOI: 10.1111/cmi.12871] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/12/2022]
Abstract
Prostaglandin E2 (PGE2 ) plays a critical role in intestinal mucosal tolerance and barrier integrity. Cyclooxygenase-2 (COX-2)-dependent PGE2 production involves mobilisation of arachidonic acid. Lactobacillus rhamnosus GG (LbGG) is one of the most widely used probiotics reported to colonise the colonic mucosa. LbGG contributes to the protection of the small intestine against radiation injury through the repositioning of mucosal COX-2 expressing cells. However, it is unknown if LbGG modulates PGE2 production in the colonic mucosa under homeostasis and the major cellular elements involved in these processes. Colonic epithelial and CD90+ mesenchymal stromal cells, also known as (myo) fibroblasts (CMFs), are abundant innate immune cells in normal colonic mucosa able to produce PGE2 . Herein, we tested the hypothesis that under colonic mucosal homeostasis, LbGG modulates the eicosanoid pathway resulting in increased PGE2 production in both epithelial and stromal cells. Among the five tested human colonic epithelial cell lines, only exposure of Caco-2 to LbGG for 24 hr led to the mobilisation of arachidonic acid with concomitant increase in the components within the leukotriene and COX-2-dependent PGE2 pathways. By contrast, CMFs isolated from the normal human colonic mucosa responded to LbGG with increased expression of COX-2 and PGE2 in the prostaglandin pathway, but not 5-LO in the leukotriene pathway. Oral gavage of C57BL/6 mice for 5 days with LbGG (5 × 108 Colony-Forming Unit (CFU)/dose) increased COX-2 expression in the colonic mucosa. The majority of cells upregulating COX-2 protein expression were located in the colonic lamina propria and colocalised with α-SMA+ cells corresponding to the CMF phenotype. This process was myeloid differentiation factor-88-dependent, because silencing of myeloid differentiation factor-88 expression in CMFs abrogated LbGG-induced upregulation of COX-2 in culture and in vivo. Taken together, our data suggest that LbGG increases release of COX-2-mediated PGE2 , contributing to the maintenance of mucosal homeostasis in the colon and CMFs are among the major contributors to this process.
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Affiliation(s)
- Gabriela Uribe
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Romain Villéger
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Philippe Bressollier
- Laboratoire de Microbiologie, Bordeaux Sciences Agro, University of Bordeaux, Gradignan, France
| | - Rachel N Dillard
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Daniel L Worthley
- Cancer Theme, University of Adelaide and SAHMRI, Adelaide, Australia
| | - Timothy C Wang
- Department of Medicine, Columbia University Medical Center, New York, New York, USA
| | - Don W Powell
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Maria C Urdaci
- Laboratoire de Microbiologie, Bordeaux Sciences Agro, University of Bordeaux, Gradignan, France
| | - Irina V Pinchuk
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
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Ness T, Abdallah M, Adams J, Alvarado C, Gunn E, House B, Lamb J, Macguire J, Norris E, Robinson R, Sapp M, Sharma J, Garner R. Candida albicans-derived mannoproteins activate NF-κB in reporter cells expressing TLR4, MD2 and CD14. PLoS One 2017; 12:e0189939. [PMID: 29281684 PMCID: PMC5744952 DOI: 10.1371/journal.pone.0189939] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/05/2017] [Indexed: 01/10/2023] Open
Abstract
The ability of soluble C. albicans 20A (serotype A) mannoprotein (CMP) to serve as a ligand for toll-like receptor 4 (TLR4) and its co-receptors was examined using commercially available and stably-transfected HEK293 cells that express human TLR4, MD2 and CD14, but not MR. These TLR4 reporter cells also express an NF-κB-dependent, secreted embryonic alkaline phosphatase (SEAP) reporter gene. TLR4-reporter cells exhibited a dose-dependent SEAP response to both LPS and CMP, wherein peak activation was achieved after stimulation with 40–50 μg/mL of CMP. Incubation on polymyxin B resin had no effect on CMP’s ligand activity, but neutralized LPS-spiked controls. HEK293 Null cells lacking TLR4 and possessing the same SEAP reporter failed to respond to LPS or CMP, but produced SEAP when activated with TNFα. Reporter cell NF-κB responses were accompanied by transcription of IL-8, TNFα, and COX-2 genes. Celecoxib inhibited LPS-, CMP-, and TNFα-dependent NF-κB responses; whereas, indomethacin had limited effect on LPS and CMP responses. SEAP production in response to C. albicans A9 mnn4Δ mutant CMP, lacking phosphomannosylations on N-linked glycans, was significantly greater (p ≤ 0.005) than SEAP responses to CMP derived from parental A9 (both serotype B). These data confirm that engineered human cells expressing TLR4, MD2 and CD14 can respond to CMP with NF-κB activation and the response can be influenced by variations in CMP-mannosylation. Future characterizations of CMPs from other sources and their application in this model may provide further insight into variations observed with TLR4 dependent innate immune responses targeting different C. albicans strains.
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Affiliation(s)
- Traci Ness
- Department of Biology, Armstrong State University, Savannah, Georgia, United States of America
| | - Mahmud Abdallah
- Department of Biology, Armstrong State University, Savannah, Georgia, United States of America
| | - Jaime Adams
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Claudia Alvarado
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Edwin Gunn
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Brittany House
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - John Lamb
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Jack Macguire
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Emily Norris
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Rebekah Robinson
- Department of Biology, Armstrong State University, Savannah, Georgia, United States of America
| | - Morgan Sapp
- Department of Biology, Armstrong State University, Savannah, Georgia, United States of America
| | - Jill Sharma
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
| | - Ronald Garner
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, United States of America
- * E-mail:
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Falach R, Sapoznikov A, Gal Y, Israeli O, Leitner M, Seliger N, Ehrlich S, Kronman C, Sabo T. Quantitative profiling of the in vivo enzymatic activity of ricin reveals disparate depurination of different pulmonary cell types. Toxicol Lett 2016; 258:11-19. [PMID: 27298272 DOI: 10.1016/j.toxlet.2016.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/31/2016] [Accepted: 06/02/2016] [Indexed: 11/28/2022]
Abstract
The plant-derived toxins ricin and abrin, operate by site-specific depurination of ribosomes, which in turn leads to protein synthesis arrest. The clinical manifestation following pulmonary exposure to these toxins is that of a severe lung inflammation and respiratory insufficiency. Deciphering the pathways mediating between the catalytic activity and the developing lung inflammation, requires a quantitative appreciation of the catalytic activity of the toxins, in-vivo. In the present study, we monitored truncated cDNA molecules which are formed by reverse transcription when a depurinated 28S rRNA serves as template. We found that maximal depurination after intranasal exposure of mice to 2LD50 ricin was reached 48h, where nearly 40% of the ribosomes have been depurinated and that depurination can be halted by post-exposure administration of anti-ricin antibodies. We next demonstrated that the effect of ricin intoxication on different cell types populating the lungs differs greatly, and that outstandingly high levels of damage (80% depurination), were observed in particular for pulmonary epithelial cells. Finally, we found that the magnitude of depurination induced by the related plant-derived toxin abrin, was significantly lower in comparison to ricin, and can be attributed mostly to reduced depurination of pulmonary epithelial cells by abrin. This study provides for the first time vital information regarding the scope and timing of the catalytic performance of ricin and abrin in the lungs of intact animals.
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Affiliation(s)
- Reut Falach
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Anita Sapoznikov
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Moshe Leitner
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Nehama Seliger
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Sharon Ehrlich
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel.
| | - Tamar Sabo
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
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Zhang X, Zheng T, Sang L, Apisa L, Zhao H, Fu F, Wang Q, Wang Y, Zheng Q. Otitis media induced by peptidoglycan-polysaccharide (PGPS) in TLR2-deficient (Tlr2(-/-)) mice for developing drug therapy. INFECTION GENETICS AND EVOLUTION 2015; 35:194-203. [PMID: 26296608 DOI: 10.1016/j.meegid.2015.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 08/12/2015] [Accepted: 08/17/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Toll like receptor 2 (TLR2) signaling can regulate the pathogenesis of otitis media (OM). However, the precise role of TLR2 signaling in OM has not been clarified due to the lack of an optimal animal model. Peptidoglycan-polysaccharide (PGPS) of the bacterial cell wall can induce inflammation by activating the TLR2 signaling. This study aimed at examining the pathogenic characteristics of OM induced by PGPS in Tlr2(-/-) mice, and the potential therapeutic effect of sodium aescinate (SA) in this model. METHODS Wild-type (WT) and Tlr2(-/-) mice were inoculated with streptococcal PGPS into their middle ears (MEs) and treated intravenously with vehicle or SA daily beginning at 3days prior to PGPS for 6 consecutive days. The pathologic changes of individual mice were evaluated longitudinally. RESULTS In comparison with WT mice, Tlr2(-/-) mice were susceptible to PGPS-induced OM. Tlr2(-/-) mice displayed greater hearing loss, tympanic membrane damage, ME mucosal thickening, longer inflammation state, cilia and goblet cell loss. SA-treatment decreased neutrophil infiltration, modulated TLR2-related gene expression and improved ciliary organization. CONCLUSIONS PGPS induced a relatively stable OM in Tlr2(-/-) mice, providing a new model for OM research. Treatment with SA mitigated the pathogenic damage in the ME and may be valuable for intervention of OM.
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Affiliation(s)
- Xiaolin Zhang
- Transformative Otology and Neuroscience Center, Binzhou Medical University, Yantai 264003, Shandong, PR China; Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Tihua Zheng
- Transformative Otology and Neuroscience Center, Binzhou Medical University, Yantai 264003, Shandong, PR China
| | - Lu Sang
- Transformative Otology and Neuroscience Center, Binzhou Medical University, Yantai 264003, Shandong, PR China
| | - Luke Apisa
- Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Hongchun Zhao
- Department of Otolaryngology/Head and Neck Surgery, Institute of Otolaryngology, Affiliated Hospital of Binzhou Medical University, Binzhou 256600, Shandong, PR China
| | - Fenghua Fu
- Department of Pharmacology, School of Pharmacy, Yantai University, Yantai 264003, Shandong, PR China
| | - Qingzhu Wang
- Transformative Otology and Neuroscience Center, Binzhou Medical University, Yantai 264003, Shandong, PR China
| | - Yanfei Wang
- Department of Otolaryngology/Head and Neck Surgery, Institute of Otolaryngology, Affiliated Hospital of Binzhou Medical University, Binzhou 256600, Shandong, PR China.
| | - Qingyin Zheng
- Transformative Otology and Neuroscience Center, Binzhou Medical University, Yantai 264003, Shandong, PR China; Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH 44106, USA.
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6
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Boltaña S, Tridico R, Teles M, Mackenzie S, Tort L. Lipopolysaccharides isolated from Aeromonas salmonicida and Vibrio anguillarum show quantitative but not qualitative differences in inflammatory outcome in Sparus aurata (Gilthead seabream). FISH & SHELLFISH IMMUNOLOGY 2014; 39:475-482. [PMID: 24954838 DOI: 10.1016/j.fsi.2014.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/09/2014] [Accepted: 06/05/2014] [Indexed: 06/03/2023]
Abstract
In fish, the defence system recognises pathogenic microorganisms via pathogen recognition receptors (PRRs) that sense particular structures of the pathogens; the so-called pathogen associated molecular patterns (PAMPs) such as bacterial lipopolysaccharides (LPSs). The result of the PAMP-PRR interactions leads to complex and orchestrated immune responses. In this study, Sparus aurata (Gilthead seabream) were intraperitoneally injected with purified lipopolysaccharide (LPS) from Aeromonas salmonicida (As)- and Vibrio anguillarum (Va) (1 mg*Kgfish(-1)), both Gram negative bacteria responsible for vibriosis and furunculosis respectively, therefore causing an impact upon marine fish cultures. Head-kidney, intestine, spleen, liver and blood samples were collected at 3, 6, 12 and 24 h post-injection. Plasma levels of cortisol, prostaglandins and lactate were measured and were significantly increased after As-LPS and Va-LPS treatment. Furthermore, tissue-specific differences of the gene regulatory patterns were evident for each LPS. When monocyte/macrophage cell cultures were challenged with As-LPS and Va-LPS, the pro-inflammatory cytokine mRNA abundances present a similar pattern of response. However, As-LPS always triggered a stronger response concerning TNFα, IL1β and cyclooxygenase-2 (COX2) mRNA abundance as well as PGE2 levels in the supernatant. Overall, the results indicate that specific LPSs do not activate different pro-inflammatory responses and that the observed gene expression pattern is tissue and concentration dependent.
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Affiliation(s)
- S Boltaña
- Institut de Biotecnologia i de Biomedicina, Universitat Autónoma de Barcelona, Bellaterra, Barcelona 08193, Spain; Institute of Aquaculture, University of Stirling, UK.
| | - R Tridico
- Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, 08193 Barcelona, Spain
| | - M Teles
- Institut de Biotecnologia i de Biomedicina, Universitat Autónoma de Barcelona, Bellaterra, Barcelona 08193, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, 08193 Barcelona, Spain
| | - S Mackenzie
- Institut de Biotecnologia i de Biomedicina, Universitat Autónoma de Barcelona, Bellaterra, Barcelona 08193, Spain; Institute of Aquaculture, University of Stirling, UK
| | - L Tort
- Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, 08193 Barcelona, Spain
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Kogut MH, He H, Genovese KJ. Bacterial toll-like receptor agonists induce sequential NF-κB-mediated leukotriene B4 and prostaglandin E2 production in chicken heterophils. Vet Immunol Immunopathol 2011; 145:159-70. [PMID: 22119018 DOI: 10.1016/j.vetimm.2011.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/25/2011] [Accepted: 11/03/2011] [Indexed: 01/08/2023]
Abstract
Studies of the response of the primary avian polymorphonuclear leukocyte, the heterophil, to microbe associated molecular patterns (MAMPs) through toll-like receptors (TLR) has concentrated on the activation of the respiratory burst, release of intracellular granules, and the induction of cytokine and chemokine expression. Virtually no studies have been described on the role of lipid mediators, leukotrienes and prostaglandins, as effectors of the avian inflammatory response. We have previously shown that flagellin (FLG), the bacterial lipoprotein mimic palmitoly-3-cysteine-serine-lysine-4 (PAM), and unmethylated CpG motifs of bacteria DNA (CpG) are all potent activators of the avian innate immune system. In the present studies, we hypothesized that FLG, PAM, and CpG are also capable of eliciting the production of these lipid mediators of inflammation by avian heterophils. Compared to non-stimulated control heterophils, all three TLR agonists were potent inducers (3-5-fold increase) of a rapid production (30 min) of leukotriene B(4) (LTB(4)) followed by a later release (60-120 min) of prostaglandin (PGE(2)) by the heterophils. LTB(4) and PGE(2) production were derived from lipoxygenase-5 (5-LO) and cyclooxygenase-2 (COX-2) enzymatic activities, respectively, as the selective 5-LO (caffeic acid) and COX-2 (NS-398) inhibitors eliminated LTB(4) and PGE(2) production from the MAMP-stimulated heterophils. These results demonstrate that both the lipoxygenase and cycloxygenase pathways are operational in avian heterophils in response to bacterial MAMPs. Treatment of heterophils with either FLG, PAM, or CpG also induced a significant increase in DNA binding by NF-κB family members' p50, c-Rel, and RelB. Additionally, the production of LTB(4) and PGE(2) were inhibited following treatment of heterophils with the specific pharmacologic inhibitor of NF-κB (Bay 11-7086), thus suggesting that TLR pathway activation of NF-κB controls LTB(4) and PGE(2) production. This the first report of the production of lipid mediators of inflammation by avian heterophils in response to PAMPs. Since FLG, lipoproteins, and bacterial CpG DNA are abundant during bacterial infections, these data support their role in the inflammatory response mediated by avian heterophils.
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Affiliation(s)
- Michael H Kogut
- USDA-ARS, Southern Plains Agricultural Research Center, College Station, TX 77845, USA.
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Barrett NA, Rahman OM, Fernandez JM, Parsons MW, Xing W, Austen KF, Kanaoka Y. Dectin-2 mediates Th2 immunity through the generation of cysteinyl leukotrienes. ACTA ACUST UNITED AC 2011; 208:593-604. [PMID: 21357742 PMCID: PMC3058587 DOI: 10.1084/jem.20100793] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The innate signaling pathways for Th2 immunity activated by inhaled antigens are not well defined. We previously identified Dectin-2 as a receptor for glycans in allergen extracts from the house dust mite Dermatophagoides farinae (Df) that mediates cysteinyl leukotriene (cys-LT) generation from pulmonary CD11c+ cells and from GM-CSF-cultured bone marrow cells (BMCs(GM-CSF)). Using lentiviral knockdown of Dectin-2 in BMCs(GM-CSF) and adoptive transfer of Df-pulsed BMCs(GM-CSF) to sensitize naive mice, we now report that Dectin-2 is critical for the development of Df-elicited eosinophilic and neutrophilic pulmonary inflammation and Th2 cytokine generation in the lungs and restimulated lymph nodes. Sensitization with Df-pulsed BMCs(GM-CSF) from LTC(4) synthase (LTC(4)S)-deficient mice or type 1 cys-LT receptor (CysLT1R)-deficient mice demonstrated that both proteins were required for Df-elicited eosinophilic pulmonary inflammation and Th2 cytokine generation in the lungs and restimulated lymph nodes. Direct sensitization and challenge of Ltc4s-/- and Cysltr1-/- mice confirmed that cys-LTs mediate these parameters of Df-elicited Th2 pulmonary inflammation. Thus, the Dectin-2-cys-LT pathway is critical for the induction of Th2 immunity to a major allergen, in part through CysLT1R. These findings identify a previously unrecognized link between a myeloid C-type lectin receptor and Th2 immunity.
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Affiliation(s)
- Nora A Barrett
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA 02115, USA
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9
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Shiga toxin 1 and ricin A chain bind to human polymorphonuclear leucocytes through a common receptor. Biochem J 2010; 432:173-80. [PMID: 20809900 DOI: 10.1042/bj20100455] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The main cause of acute renal failure in children is HUS (haemolytic uraemic syndrome), a consequence of intestinal infections with Escherichia coli strains producing Stx (Shiga toxins). Stx released in the gut by the non-invasive bacteria reach the bloodstream and are targeted to cerebral and renal endothelium triggering HUS. PMN (polymorphonuclear leucocytes) seem to be involved in Stx delivery through an unidentified membrane receptor (Kd=10⁻⁸ M; 2×10⁵ binding sites) which does not allow internalization. Some experts in the field have defined the Stx-PMN interaction as non-specific and of little biological significance. In the present study, we show that the A chain of ricin, the well-known plant RIP (ribosome-inactivating protein), interacts with PMN (Kd=10⁻⁹ M; 2×10⁵ binding sites) competing for the same receptor that recognizes Stx, whereas diphtheria toxin and several agonists of TLRs (Toll-like receptors) or the mannose receptor were ineffective. No toxic effects of ricin A chain on PMN were observed, as assessed by measuring protein synthesis and the rate of spontaneous apoptosis of leucocytes. Moreover, two single-chain RIPs (gelonin and saporin S6) had the same competing effect. Thus RIPs and Stx1 share structural similarities, the same enzymatic activity and a common receptor on PMN. These observations reveal that the Stx-PMN interaction is specific, confirming that PMN recognize molecular patterns common to different foreign molecules.
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10
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Eicosanoids in the innate immune response: TLR and non-TLR routes. Mediators Inflamm 2010; 2010. [PMID: 20689730 PMCID: PMC2905620 DOI: 10.1155/2010/201929] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 04/09/2010] [Indexed: 12/14/2022] Open
Abstract
The variable array of pattern receptor expression in different cells of the innate immune system explains the induction of distinct patterns of arachidonic acid (AA) metabolism. Peptidoglycan and mannan were strong stimuli in neutrophils, whereas the fungal extract zymosan was the most potent stimulus in monocyte-derived dendritic cells since it induced the production of PGE2, PGD2, and several cytokines including a robust IL-10 response. Zymosan activated κB-binding activity, but inhibition of NF-κB was associated with enhanced IL-10 production. In contrast, treatments acting on CREB (CRE binding protein), including PGE2, showed a direct correlation between CREB activation and IL-10 production. Therefore, in dendritic cells zymosan induces il10 transcription by a CRE-dependent mechanism that involves autocrine secretion of PGE2, thus unraveling a functional cooperation between eicosanoid production and cytokine production.
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11
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Hsu MJ, Chang CK, Chen MC, Chen BC, Ma HP, Hong CY, Lin CH. Apoptosis signal-regulating kinase 1 in peptidoglycan-induced COX-2 expression in macrophages. J Leukoc Biol 2010; 87:1069-82. [PMID: 20200402 DOI: 10.1189/jlb.1009668] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In this study, we investigated the role of ASK1 in PGN-induced C/EBPbeta activation and COX-2 expression in RAW 264.7 macrophages. The PGN-induced COX-2 expression was attenuated by the DNs of ASK1, JNK1, JNK2, a JNK inhibitor (SP600125), and an AP-1 inhibitor (curcumin). PGN caused ASK1 dephosphorylation time-dependently at Ser967, dissociation from the ASK1-14-3-3 complex, and subsequent ASK1 activation. In addition, PGN activated PP2A and suppression of PP2A by okadaic acid markedly inhibited PGN-induced ASK1 Ser967 dephosphorylation and COX-2 expression. PGN induced the activation of the JNK-AP-1 signaling cascade downstream of ASK1. PGN-increased C/EBPbeta expression and DNA-binding activity were inhibited by the ASK1-JNK-AP-1 signaling blockade. COX-2 promoter luciferase activity induced by PGN was attenuated in cells transfected with the COX-2 reporter construct possessing the C/EBP-binding site mutation. In addition, the ASK1-JNK-AP-1-C/EBPbeta cascade was activated in human peripheral mononuclear cells exposure to PGN. The TLR2 agonist Pam(3)CSK(4) was also shown to induce ASK1 Ser967 dephosphorylation, JNK and c-jun phosphorylation, C/EBPbeta activation, and COX-2 expression in RAW 264.7 macrophages. PGN-induced COX-2 promoter luciferase activity was prevented by selective inhibition of TLR2 and c-Jun in RAW 264.7 macrophages. Our data demonstrate that PGN might activate the TLR2-mediated PP2A-ASK1-JNK-AP-1-C/EBPbeta cascade and subsequent COX-2 expression in RAW 264.7 macrophages.
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Affiliation(s)
- Ming-Jen Hsu
- Graduate Institute of Medical Sciences, Department of Pharmacology, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan
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12
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Esworthy RS, Smith DD, Chu FF. A Strong Impact of Genetic Background on Gut Microflora in Mice. Int J Inflam 2010; 2010:986046. [PMID: 20976020 PMCID: PMC2957666 DOI: 10.4061/2010/986046] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Genetic background affects susceptibility to ileocolitis in mice deficient in two intracellular glutathione peroxidases, GPx1 and GPx2. The C57BL/6 (B6) GPx1/2 double-knockout (DKO) mice have mild ileocolitis, and 129S1/Sv (129) DKO mice have severe inflammation. We used diet to modulate ileocolitis; a casein-based defined diet with AIN76A micronutrients (AIN) attenuates inflammation compared to conventional LabDiets. Because luminal microbiota induce DKO ileocolitis, we assessed bacterial composition with automated ribosomal intergenic-spacer analysis (ARISA) on cecal DNA. We found that mouse strain had the strongest impact on the composition of microbiota than diet and GPx genotypes. In comparing AIN and LabDiet, DKO mice were more resistant to change than the non-DKO or WT mice. However, supplementing yeast and inulin to AIN diet greatly altered microflora profiles in the DKO mice. From 129 DKO strictly, we found overgrowth of Escherichia coli. We conclude that genetic background predisposes mice to colonization of potentially pathogenic E. coli.
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Affiliation(s)
- R Steven Esworthy
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 Duarte Road, Duarte, CA 91010-3000, USA
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Simard P, Galarneau H, Marois S, Rusu D, Hoemann CD, Poubelle PE, El-Gabalawy H, Fernandes MJG. Neutrophils exhibit distinct phenotypes toward chitosans with different degrees of deacetylation: implications for cartilage repair. Arthritis Res Ther 2009; 11:R74. [PMID: 19460141 PMCID: PMC2714120 DOI: 10.1186/ar2703] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 02/23/2009] [Accepted: 05/21/2009] [Indexed: 11/14/2022] Open
Abstract
Introduction Osteoarthritis is characterized by the progressive destruction of cartilage in the articular joints. Novel therapies that promote resurfacing of exposed bone in focal areas are of interest in osteoarthritis because they may delay the progression of this disabling disease in patients who develop focal lesions. Recently, the addition of 80% deacetylated chitosan to cartilage microfractures was shown to promote the regeneration of hyaline cartilage. The molecular mechanisms by which chitosan promotes cartilage regeneration remain unknown. Because neutrophils are transiently recruited to the microfracture site, the effect of 80% deacetylated chitosan on the function of neutrophils was investigated. Most studies on neutrophils use preparations of chitosan with an uncertain degree of deacetylation. For therapeutic purposes, it is of interest to determine whether the degree of deacetylation influences the response of neutrophils to chitosan. The effect of 95% deacetylated chitosan on the function of neutrophils was therefore also investigated and compared with that of 80% deacetylated chitosan. Methods Human blood neutrophils from healthy donors were isolated by centrifugation on Ficoll-Paque. Chemotaxis was performed using the chemoTX system. Production of superoxide anions was evaluated using the cytochrome c reduction assay. Degranulation was determined by evaluating the release of myeloperoxidase and lactoferrin. The internalization of fluorescently labelled 80% deacetylated chitosan by neutrophils was studied by confocal microscopy. Results Neutrophils were dose dependently attracted to 80% deacetylated chitosan. In contrast, 95% deacetylated chitosan was not chemotactic for neutrophils. Moreover, the majority of the chemotactic effect of 80% deacetylated chitosan was mediated by phospholipase-A2-derived bioactive lipids. Contrary to the induction of chemotaxis, neither 80% nor 95% deacetylated chitosan activated the release of granule enzymes or the generation of active oxygen species. Despite the distinct response of neutrophils toward 80% and 95% deacetylated chitosan, both chitosans were internalized by neutrophils. Conclusions Eighty per cent deacetylated chitosan induces a phenotype in neutrophils that is distinct from the classical phenotype induced by pro-inflammatory agents. Our observations also indicate that the degree of deacetylation is an important factor to consider in the use of chitosan as an accelerator of repair because neutrophils do not respond to 95% deacetylated chitosan.
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Affiliation(s)
- Pascale Simard
- Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du CHUQ-CHUL, Laurier, Québec G1V 4G2, Canada.
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Lindner SC, Köhl U, Maier TJ, Steinhilber D, Sorg BL. TLR2 ligands augment cPLA2
α activity and lead to enhanced leukotriene release in human monocytes. J Leukoc Biol 2009; 86:389-99. [DOI: 10.1189/jlb.1008591] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Barrett NA, Maekawa A, Rahman OM, Austen KF, Kanaoka Y. Dectin-2 recognition of house dust mite triggers cysteinyl leukotriene generation by dendritic cells. THE JOURNAL OF IMMUNOLOGY 2009; 182:1119-28. [PMID: 19124755 DOI: 10.4049/jimmunol.182.2.1119] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
House dust mites are a significant source of airborne allergen worldwide, but there is little understanding of how they so potently generate allergic inflammation. We found that extracts from the house dust mites Dermatophagoides farinae (Df) and Dermatophagoides pteronyssinus and from the mold Aspergillus fumigatus stimulated a rapid and robust production of cysteinyl leukotrienes (cys-LTs), proinflammatory lipid mediators, from mouse bone marrow-derived dendritic cells (BMDCs). Con A affinity chromatography of the Df extract revealed that the relevant ligand is a glycan(s), suggesting stimulation via a dendritic cell (DC) lectin receptor. Cys-LT production in BMDCs from wild-type mice was inhibited by spleen tyrosine kinase (Syk) inhibitors and was abolished in BMDCs from FcRgamma-/- mice, implicating either Dectin-2 or DC immunoactivating receptor. Transfection of each receptor in bone marrow-derived mast cells revealed that only Dectin-2 mediates cys-LT production by Df, Dermatophagoides pteronyssinus, and Aspergillus fumigatus. Lentiviral knockdown of Dectin-2 in BMDCs attenuated Df extract-elicited cys-LT generation, thereby identifying Dectin-2 as the receptor. Lung CD11c+ cells, but not peritoneal or alveolar macrophages, also generated cys-LTs in response to Df. These findings place Dectin-2 among the C-type lectin receptors that activate arachidonic acid metabolism and identify the Dectin-2/FcRgamma/Syk/cys-LT axis as a novel mechanism by which three potent indoor allergens may activate innate immune cells to promote allergic inflammation.
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Affiliation(s)
- Nora A Barrett
- Department of Medicine, Harvard Medical School, and Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA
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Expression of phospholipases A2 in primary human lung macrophages: role of cytosolic phospholipase A2-alpha in arachidonic acid release and platelet activating factor synthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1791:92-102. [PMID: 19130898 DOI: 10.1016/j.bbalip.2008.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 11/24/2008] [Accepted: 12/05/2008] [Indexed: 10/21/2022]
Abstract
Macrophages are a major source of lipid mediators in the human lung. Expression and contribution of cytosolic (cPLA(2)) and secreted phospholipases A(2) (sPLA(2)) to the generation of lipid mediators in human macrophages are unclear. We investigated the expression and role of different PLA(2)s in the production of lipid mediators in primary human lung macrophages. Macrophages express the alpha, but not the zeta isoform of group IV and group VIA cPLA(2) (iPLA(2)). Two structurally-divergent inhibitors of group IV cPLA(2) completely block arachidonic acid release by macrophages in response to non-physiological (Ca(2+) ionophores and phorbol esters) and physiological agonists (lipopolysaccharide and Mycobacterium protein derivative). These inhibitors also reduce by 70% the synthesis of platelet-activating factor by activated macrophages. Among the full set of human sPLA(2)s, macrophages express group IIA, IID, IIE, IIF, V, X and XIIA, but not group IB and III enzymes. Me-Indoxam, a potent and cell impermeable inhibitor of several sPLA(2)s, has no effect on arachidonate release or platelet-activating factor production. Agonist-induced exocytosis is not influenced by cPLA(2) inhibitors at concentrations that block arachidonic acid release. Our results indicate that human macrophages express cPLA(2)-alpha, iPLA(2) and several sPLA(2)s. Cytosolic PLA(2)-alpha is the major enzyme responsible for lipid mediator production in human macrophages.
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Valera I, Fernández N, Trinidad AG, Alonso S, Brown GD, Alonso A, Crespo MS. Costimulation of dectin-1 and DC-SIGN triggers the arachidonic acid cascade in human monocyte-derived dendritic cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:5727-36. [PMID: 18390758 DOI: 10.4049/jimmunol.180.8.5727] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inflammatory mediators derived from arachidonic acid (AA) alter the function of dendritic cells (DC), but data regarding their biosynthesis resulting from stimulation of opsonic and nonopsonic receptors are scarce. To address this issue, the production of eicosanoids by human monocyte-derived DC stimulated via receptors involved in Ag recognition was assessed. Activation of FcgammaR induced AA release, short-term, low-grade PG biosynthesis, and IL-10 production, whereas zymosan, which contains ligands of both the mannose receptor and the human beta-glucan receptor dectin-1, induced a wider set of responses including cyclooxygenase 2 induction and biosynthesis of leukotriene C(4) and IL-12p70. The cytosolic phospholipase A(2) inhibitor pyrrolidine 1 completely inhibited AA release stimulated via all receptors, whereas the spleen tyrosine kinase (Syk) inhibitors piceatannol and R406 fully blocked AA release in response to immune complexes, but only partially blocked the effect of zymosan. Furthermore, anti-dectin-1 mAb partially inhibited the response to zymosan, and this inhibition was enhanced by mAb against DC-specific ICAM-3-grabbing nonintegrin (SIGN). Immunoprecipitation of DC lysates showed coimmunoprecipitation of DC-SIGN and dectin-1, which was confirmed using Myc-dectin-1 and DC-SIGN constructs in HEK293 cells. These data reveal a robust metabolism of AA in human DC stimulated through both opsonic and nonopsonic receptors. The FcgammaR route depends on the ITAM/Syk/cytosolic phospholipase A(2) axis, whereas the response to zymosan involves the interaction with the C-type lectin receptors dectin-1 and DC-SIGN. These findings help explain the distinct functional properties of DC matured by immune complexes vs those matured by beta-glucans.
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Affiliation(s)
- Isela Valera
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, Valladolid, Spain
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Oligodendrocyte Generation Is Differentially Influenced by Toll-Like Receptor (TLR) 2 and TLR4-Mediated Intraspinal Macrophage Activation. J Neuropathol Exp Neurol 2007; 66:1124-35. [DOI: 10.1097/nen.0b013e31815c2530] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Fernández N, González A, Valera I, Alonso S, Crespo MS. Mannan and peptidoglycan induce COX-2 protein in human PMN via the mammalian target of rapamycin. Eur J Immunol 2007; 37:2572-82. [PMID: 17683115 DOI: 10.1002/eji.200737262] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The induction of cyclooxygenase-2 (COX-2) protein expression was assessed in human polymorphonuclear leukocytes (PMN) stimulated via receptors of the innate immune system. Peptidoglycan (PGN) and mannan, and at a lower extent the bacterial lipoprotein mimic palmitoyl-3-cysteine-serine-lysine-4, induced COX-2 protein expression. In contrast, lipoteichoic acid and muramyldipeptide were irrelevant stimuli. The mRNA encoding COX-2 was present in resting PMN at an extent quite similar to that detected in stimulated PMN, whereas the expression of COX-2 protein was undetectable. Treatment with the phosphatidylinositol 3-kinase inhibitor (PI3K) wortmaninn, the mammalian target of rapamycin (mTOR) inhibitor rapamycin, and the translation inhibitor cycloheximide blocked the induction of COX-2 protein in response to mannan and PGN, whereas the transcriptional inhibitor actinomycin D did not show a significant effect. These results disclose a capability of pathogen-associated molecular patterns to induce the oxidative metabolism of arachidonic acid more robust than that of PMN archetypal chemoattractants, since mannan and PGN make it coincidental the release of arachidonic acid with a rapid induction of COX-2 protein regulated by a signaling cascade involving PI3K, mTOR, and the translation machinery. This mechanism of COX-2 protein induction expression in PMN is substantially different from that operative in mononuclear phagocytes, which is highly dependent on transcriptional regulation.
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Affiliation(s)
- Nieves Fernández
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, Valladolid, Spain
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