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Li G, Wang Y, Qian L, Li D, Yao Y, Pan J, Fan D. C8-ceramide modulates microglia BDNF expression to alleviate postoperative cognition dysfunction via PKCδ/NF-κB signaling pathway. Exp Brain Res 2024; 242:1543-1559. [PMID: 38750371 PMCID: PMC11208206 DOI: 10.1007/s00221-024-06847-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 05/06/2024] [Indexed: 06/27/2024]
Abstract
Postoperative cognitive dysfunction (POCD) is a kind of serious postoperative complication in surgery with general anesthesia and it may affect patients' normal lives. Activated microglia are thought to be one of the key factors in the regulation of POCD process. Once activated, resident microglia change their phenotype and secrete kinds of cytokines to regulate inflammatory response in tissues. Among these secretory factors, brain-derived neurotrophic factor (BDNF) is considered to be able to inhibit inflammation response and protect nervous system. Therefore, the enhancement of BDNF expression derived from resident microglia is suggested to be potential treatment for POCD. In our study, we focused on the role of C8-ceramide (a kind of interventional drug) and assessed its regulatory effect on improving the expression of BDNF secreted from microglia to treat POCD. According to the results of our study, we observed that C8-ceramide stimulated primary microglia to up-regulate the expression of BDNF mRNA after being treated with lipopolysaccharide (LPS) in vitro. We proved that C8-ceramide had ability to effectively improve POCD of mice after being accepted carotid artery exposure and their abnormal behavior recovered better than that of mice from the surgery group. Furthermore, we also demonstrated that C8-ceramide enhanced the cognitive function of mice via the PKCδ/NF-κB signaling pathway. In general, our study has confirmed a potential molecular mechanism that led to the occurrence of POCD caused by surgery and provided a new clinical strategy to treat POCD.
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Affiliation(s)
- Guangqian Li
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, #32 West Second Section, First-Ring Road, Chengdu, 610072, People's Republic of China
| | - Yuhao Wang
- State Key Laboratory of Oral Diseases and National Center for Stomatology and National Clinical Research Center for Oral Diseases and Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Frontier Innovation Center for Dental Medicine Plus, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lei Qian
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, #32 West Second Section, First-Ring Road, Chengdu, 610072, People's Republic of China
| | - Danni Li
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, #32 West Second Section, First-Ring Road, Chengdu, 610072, People's Republic of China
| | - Yuchen Yao
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, #32 West Second Section, First-Ring Road, Chengdu, 610072, People's Republic of China
| | - Jian Pan
- State Key Laboratory of Oral Diseases and National Center for Stomatology and National Clinical Research Center for Oral Diseases and Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
- Frontier Innovation Center for Dental Medicine Plus, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Dan Fan
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, #32 West Second Section, First-Ring Road, Chengdu, 610072, People's Republic of China.
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2
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de Wit NM, Mol K, Rodríguez-Lorenzo S, de Vries HE, Kooij G. The Role of Sphingolipids and Specialized Pro-Resolving Mediators in Alzheimer's Disease. Front Immunol 2021; 11:620348. [PMID: 33633739 PMCID: PMC7902029 DOI: 10.3389/fimmu.2020.620348] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is the leading cause of dementia worldwide giving rise to devastating forms of cognitive decline, which impacts patients’ lives and that of their proxies. Pathologically, AD is characterized by extracellular amyloid deposition, neurofibrillary tangles and chronic neuroinflammation. To date, there is no cure that prevents progression of AD. In this review, we elaborate on how bioactive lipids, including sphingolipids (SL) and specialized pro-resolving lipid mediators (SPM), affect ongoing neuroinflammatory processes during AD and how we may exploit them for the development of new biomarker panels and/or therapies. In particular, we here describe how SPM and SL metabolism, ranging from ω-3/6 polyunsaturated fatty acids and their metabolites to ceramides and sphingosine-1-phosphate, initiates pro- and anti-inflammatory signaling cascades in the central nervous system (CNS) and what changes occur therein during AD pathology. Finally, we discuss novel therapeutic approaches to resolve chronic neuroinflammation in AD by modulating the SPM and SL pathways.
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Affiliation(s)
- Nienke M de Wit
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Kevin Mol
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Sabela Rodríguez-Lorenzo
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Gijs Kooij
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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3
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Zwierzchowski G, Zhang G, Mandal R, Wishart DS, Ametaj BN. Milk Metabotyping Identifies Metabolite Alterations in the Whole Raw Milk of Dairy Cows with Lameness. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4507-4514. [PMID: 32223231 DOI: 10.1021/acs.jafc.9b08312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The objective of this study was to evaluate whether whole raw milk originating from Holstein dairy cows affected by lameness alters its composition. A total of 20 healthy control cows and 6 cows diagnosed with lameness were selected out of 100 sampled cows in a nested case control study at 2 weeks postpartum, and whole raw milk samples were collected and analyzed with direct inject/liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance. In total, 168 metabolites were identified and quantified using an in-house mass spectrometry library. A total of 35 of the identified metabolites decreased versus control cows. Only two metabolites (i.e., sn-glycero-3-phosphocholine and phosphatidylethanolamine ae C42:1) were increased in the milk of lame cows. In conclusion, milk metabotyping of lame cows revealed significant changes in multiple milk components, including amino acids, lipids, and biogenic amines. Most of the milk compounds identified as altered were lowered, suggesting deflection of nutrients from the mammary gland to the host needs for healing lameness-associated pathological processes.
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Affiliation(s)
- Grzegorz Zwierzchowski
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Guanshi Zhang
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Rupasri Mandal
- Departments of Biological and Computer Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - David S Wishart
- Departments of Biological and Computer Sciences, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Burim N Ametaj
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
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4
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Xue Q, Yin P, Li K, Fan H, Yang L, Cao X, Sun L, Liu Y. Identification of bioactive phenolics from Porana sinensis Hemsl. stem by UPLC-QTOF-MS/MS and the confirmation of anti-inflammatory indicators using LPS-induced RAW264.7 cells. Inflammopharmacology 2019; 27:1055-1069. [DOI: 10.1007/s10787-018-00558-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/26/2018] [Indexed: 01/18/2023]
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5
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Baker JE, Boudreau RM, Seitz AP, Caldwell CC, Gulbins E, Edwards MJ. Sphingolipids and Innate Immunity: A New Approach to Infection in the Post-Antibiotic Era? Surg Infect (Larchmt) 2018; 19:792-803. [DOI: 10.1089/sur.2018.187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Jennifer E. Baker
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
| | - Ryan M. Boudreau
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
| | - Aaron P. Seitz
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
| | - Charles C. Caldwell
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
- Division of Research, Shriners Hospital for Children, Cincinnati, Ohio
| | - Erich Gulbins
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
- Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael J. Edwards
- Division of Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio
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6
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Bezgovsek J, Gulbins E, Friedrich SK, Lang KS, Duhan V. Sphingolipids in early viral replication and innate immune activation. Biol Chem 2018; 399:1115-1123. [DOI: 10.1515/hsz-2018-0181] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/21/2018] [Indexed: 01/08/2023]
Abstract
Abstract
In this review, we summarize the mechanisms by which sphingolipids modulate virus multiplication and the host innate immune response, using a number of host-virus systems as illustrative models. Sphingolipids exert diverse functions, both at the level of the viral life cycle and in the regulation of antiviral immune responses. Sphingolipids may influence viral replication in three ways: by serving as (co)receptors during viral entry, by modulating virus replication, and by shaping the antiviral immune response. Several studies have demonstrated that sphingosine kinases (SphK) and their product, sphingosine-1-phosphate (S1P), enhance the replication of influenza, measles, and hepatitis B virus (HBV). In contrast, ceramides, particularly S1P and SphK1, influence the expression of type I interferon (IFN-I) by modulating upstream antiviral signaling and enhancing dendritic cell maturation, differentiation, and positioning in tissue. The synthetic molecule α-galactosylceramide has also been shown to stimulate natural killer cell activation and interferon (IFN)-γ secretion. However, to date, clinical trials have failed to demonstrate any clinical benefit for sphingolipids in the treatment of cancer or HBV infection. Taken together, these findings show that sphingolipids play an important and underappreciated role in the control of virus replication and the innate immune response.
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7
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Lee S, Lee D, Park JY, Seok S, Jang TS, Park HB, Shim SH, Kang KS, Kim KH. Antigastritis effects of Armillariella tabescens (Scop.) Sing. and the identification of its anti-inflammatory metabolites. J Pharm Pharmacol 2018; 70:404-412. [DOI: 10.1111/jphp.12871] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/25/2017] [Indexed: 01/09/2023]
Abstract
Abstract
Objectives
This study demonstrates the biological and chemical analysis of the mushroom Armillariella tabescens (Scop.) Sing. (Tricholomataceae).
Methods
Chemical structures of the isolates were determined by 1D and 2D NMR, and ESI-MS, as well as comparison with previously reported data. All isolates were tested for anti-inflammatory effects based on their ability to inhibit LPS-stimulated nitric oxide (NO) production in RAW264.7 cells.
Key findings
We found that the MeOH extract of the fruiting bodies of A. tabescens showed antigastritis activity against ethanol-induced gastric damage in rats and notably reduced the gastric damage index compared to control in a concentration-dependent manner. Chemical investigation of the MeOH extract led to the isolation of four steroids (1–4), three alkaloids (5–7), two nucleic acids (8–9) and four fatty acids (10–13). This is the first study to report the identification of all isolates, except for compound 7, from A. tabescens. Compounds 1, 2, 3, 4 and 10 showed inhibition on LPS-stimulated NO production. Treatment with compound 10 inhibited expression of iNOS, COX-2, phospho-IKKα, IKKα, phospho-IκBα, IκBα and NF-kappa B in LPS-stimulated RAW264.7 cells.
Conclusions
Compound 10 likely contributes to the health benefits of A. tabescens as an antigastritis agent through its anti-inflammatory effects.
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Affiliation(s)
- Seulah Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Dahae Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
- College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Jun Yeon Park
- College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Soonja Seok
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, RDA, Iseo-myeon, Wanju-gun, Jeollabuk-do, Korea
| | - Tae Su Jang
- Institute of Green Bio Science & Technology, Seoul National University, Pyeong Chang, Korea
| | - Hyun Bong Park
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Sang Hee Shim
- College of Pharmacy, Duksung Women's University, Dobong-gu, Seoul, Korea
| | - Ki Sung Kang
- College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Ki Hyun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
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Song M, Kim S, Yun HS, Kwon S. Anti-inflammatory effect of the ceramide mixture extracted from genetically modified Saccharomyces cerevisiae. BIOTECHNOL BIOPROC E 2017. [DOI: 10.1007/s12257-017-0216-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Dietary and Endogenous Sphingolipid Metabolism in Chronic Inflammation. Nutrients 2017; 9:nu9111180. [PMID: 29143791 PMCID: PMC5707652 DOI: 10.3390/nu9111180] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/21/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022] Open
Abstract
Chronic inflammation is a common underlying factor in many major metabolic diseases afflicting Western societies. Sphingolipid metabolism is pivotal in the regulation of inflammatory signaling pathways. The regulation of sphingolipid metabolism is in turn influenced by inflammatory pathways. In this review, we provide an overview of sphingolipid metabolism in mammalian cells, including a description of sphingolipid structure, biosynthesis, turnover, and role in inflammatory signaling. Sphingolipid metabolites play distinct and complex roles in inflammatory signaling and will be discussed. We also review studies examining dietary sphingolipids and inflammation, derived from in vitro and rodent models, as well as human clinical trials. Dietary sphingolipids appear to influence inflammation-related chronic diseases through inhibiting intestinal lipid absorption, altering gut microbiota, activation of anti-inflammatory nuclear receptors, and neutralizing responses to inflammatory stimuli. The anti-inflammatory effects observed with consuming dietary sphingolipids are in contrast to the observation that most cellular sphingolipids play roles in augmenting inflammatory signaling. The relationship between dietary sphingolipids and low-grade chronic inflammation in metabolic disorders is complex and appears to depend on sphingolipid structure, digestion, and metabolic state of the organism. Further research is necessary to confirm the reported anti-inflammatory effects of dietary sphingolipids and delineate their impacts on endogenous sphingolipid metabolism.
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10
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Ju Woo H, Jun DY, Lee JY, Park HS, Woo MH, Park SJ, Kim SC, Yang CH, Kim YH. Anti-inflammatory action of 2-carbomethoxy-2,3-epoxy-3-prenyl-1,4-naphthoquinone (CMEP-NQ) suppresses both the MyD88-dependent and TRIF-dependent pathways of TLR4 signaling in LPS-stimulated RAW264.7 cells. JOURNAL OF ETHNOPHARMACOLOGY 2017; 205:103-115. [PMID: 28465253 DOI: 10.1016/j.jep.2017.04.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 02/16/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The roots of Rubia cordifolia L. have been widely used as a traditional herbal medicine in Northeast Asia for treating inflammatory diseases. AIM OF THE STUDY To elucidate the anti-inflammatory mechanism of 2-carbomethoxy-2,3-epoxy-3- prenyl-1,4-naphthoquinone (CMEP-NQ), purified from the roots of R. cordifolia L. as the major anti-inflammatory component, in LPS-treated RAW264.7 murine macrophage cells. MATERIALS AND METHODS Anti-inflammatory activity of CMEP-NQ was investigated in LPS-treated RAW264.7 cells by measuring the levels of NO, PGE2, and cytokines (IL1β, IL-6, TNF-α) in the culture supernatants and the TLR4-mediated intracellular events including association of MyD88 with IRAK1, activation of IRAK1, TAK1, MAPKs, NF-κB/AP-1, and IRF3, and generation of ROS. RESULTS Pretreatment of RAW264.7 cells with CMEP-NQ reduced LPS-induced production of NO and PGE2 by suppressing iNOS and COX-2 gene expression. CMEP-NQ also reduced the secretion of IL-1β, IL-6, and TNF-α by down-regulating mRNA levels. Under these conditions, TLR4-mediated MyD88-dependent events were inhibited by CMEP-NQ, including the association of MyD88 with IRAK1, phosphorylation of IRAK1, TAK1, and MAPKs (ERK, JNK and p38 MAPK), and activation of NF-κB and AP-1. As TRIF-dependent events of TLR4 signaling, phosphorylation of IRF3 and induction of iNOS protein expression were also inhibited by CMEP-NQ. However, the binding of FITC-conjugated LPS to cell surface TLR4 was not affected by CMEP-NQ. Following LPS stimulation, intracellular ROS production was first detected by DCFH-DA staining at 1h; then it continuously increased until 16h. Although CMEP-NQ failed to exhibit DPPH radical- or ABTS radical-scavenging activity in vitro, LPS-induced ROS production in RAW264.7 cells was more efficiently blocked by CMEP-NQ than by NAC. CONCLUSIONS These results demonstrate that the suppressive effect of CMEP-NQ on LPS-induced inflammatory responses in RAW264.7 cells was mainly exerted via its inhibition of TLR4-mediated proximal events, such as MyD88-dependent NF-κB/AP-1 activation and ROS production, and TRIF-dependent IRF3 activation.
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Affiliation(s)
- Hyun Ju Woo
- Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, South Korea
| | - Do Youn Jun
- Institute of Life Science and Biotechnology, Kyungpook National University, Daegu 702-701, South Korea
| | - Ji Young Lee
- Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, South Korea
| | - Hae Sun Park
- Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, South Korea
| | - Mi Hee Woo
- College of Pharmacology, Daegu Catholic University, Gyeongsan 712-702, South Korea
| | - Sook Jahr Park
- College of Oriental Medicine, Daegu Hanny University, Daegu 706-060, South Korea
| | - Sang Chan Kim
- College of Oriental Medicine, Daegu Hanny University, Daegu 706-060, South Korea
| | - Chae Ha Yang
- College of Oriental Medicine, Daegu Hanny University, Daegu 706-060, South Korea
| | - Young Ho Kim
- Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, South Korea.
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11
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The constituent, anti-inflammation, and human neutrophil elastase inhibitory activity of Gnaphalium affine. J Funct Foods 2016. [DOI: 10.1016/j.jff.2016.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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12
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Abad B, Mesonero J, Salvador M, Garcia-Herrera J, Rodriguez-Yoldi M. Cellular mechanism underlying LPS-induced inhibition of in vitro L-leucine transport across rabbit jejunum. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519020080020601] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Lipopolysaccharide(LPS) is a known causative agent of sepsis. In previous studies, we have shown that it reduces L-leucine mediated transport across the rabbit jejunum by about 30%. In this study, the mechanism(s) of LPS inhibition on amino acid transport were analysed in detail. LPS did not inhibit L-leucine transport across brush border membrane vesicles, suggesting the need for an intracellular step. The inhibitory effect of LPS was not altered by the addition of protein kinase A (PKA) inhibitor (IP20, 10—7M) or an analog of cAMP (DB-cAMP, 3 × 10—4M), indicating that the PKA signal transduction pathway was not involved in the LPS effect. However, the inhibitory effect of LPS was suppressed by trifluoroperazine (10—7M), a Ca2+/calmodulin inhibitor and staurosporine (10—7M), an protein kinase C (PKC) inhibitor. Likewise, LPS inhibition disappeared in media without calcium. These results suggest that LPS could inhibit the intestinal uptake of L-leucine across the small intestine in vitro by intracellular processes related to calcium, involving PKC and calmodulin protein.
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Affiliation(s)
- B. Abad
- Physiology Unit, Department of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - J.E. Mesonero
- Physiology Unit, Department of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - M.T. Salvador
- Physiology Unit, Department of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - J. Garcia-Herrera
- Physiology Unit, Department of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - M.J. Rodriguez-Yoldi
- Physiology Unit, Department of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Zaragoza, Spain,
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Shoenfelt JL, Fenton MJ. TLR2- and TLR4-dependent activation of STAT1 serine phosphorylation in murine macrophages is protein kinase C-δ-independent. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519060120040401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Engagement of Toll-like receptor (TLR) proteins activates multiple signal transduction pathways. Previous studies demonstrated that TLR2 and TLR4 engagement leads to rapid phosphorylation of the transcription factor STAT1 at serine 727 (Ser-727 STAT1) in murine macrophages. Only TLR4 engagement induced STAT1 phosphorylation at tyrosine 701, although this response was delayed compared with Ser-727 STAT1 phosphorylation. Unlike other cell types, the p38 mitogen-activated protein kinase was necessary, but not sufficient, for TLR-induced phosphorylation of Ser-727 STAT1 in macrophages. We and others had previously shown that Ser-727 STAT1 phosphorylation could be blocked by rottlerin, an inhibitor of protein kinase C-δ (PKC—δ). Here we report that peritoneal exudate macrophages from PKC-δ-deficient mice can be activated through TLR2 and TLR4 to elicit rapid phosphorylation of Ser-727 STAT1, which was blocked by both rottlerin and the p38 inhibitor SB203580, but not by the pan-PKC inhibitor bisindoylmaleamide. Furthermore, both normal and PKC-δ-deficient macrophages secreted comparable amounts of IL-6, IP-10, and RANTES following TLR engagement. In contrast, IFN-γ-induced STAT1 serine phosphorylation was independent of both PKC-δ and p38. Overall, these studies demonstrate that a PKC-δindependent signaling pathway downstream of both TLR2 and TLR4 is necessary for Ser-727 STAT1 phosphorylation in primary murine macrophages.
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Affiliation(s)
- Joanna L. Shoenfelt
- Division of Pulmonary and Critical Care Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Matthew J. Fenton
- Division of Pulmonary and Critical Care Medicine and Mucosal Biology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, USA,
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14
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Płóciennikowska A, Hromada-Judycka A, Borzęcka K, Kwiatkowska K. Co-operation of TLR4 and raft proteins in LPS-induced pro-inflammatory signaling. Cell Mol Life Sci 2014; 72:557-581. [PMID: 25332099 PMCID: PMC4293489 DOI: 10.1007/s00018-014-1762-5] [Citation(s) in RCA: 499] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/01/2014] [Accepted: 10/13/2014] [Indexed: 11/28/2022]
Abstract
Toll-like receptor 4 (TLR4) is activated by lipopolysaccharide (LPS), a component of Gram-negative bacteria to induce production of pro-inflammatory mediators aiming at eradication of the bacteria. Dysregulation of the host responses to LPS can lead to a systemic inflammatory condition named sepsis. In a typical scenario, activation of TLR4 is preceded by binding of LPS to CD14 protein anchored in cholesterol- and sphingolipid-rich microdomains of the plasma membrane called rafts. CD14 then transfers the LPS to the TLR4/MD-2 complex which dimerizes and triggers MyD88- and TRIF-dependent production of pro-inflammatory cytokines and type I interferons. The TRIF-dependent signaling is linked with endocytosis of the activated TLR4, which is controlled by CD14. In addition to CD14, other raft proteins like Lyn tyrosine kinase of the Src family, acid sphingomyelinase, CD44, Hsp70, and CD36 participate in the TLR4 signaling triggered by LPS and non-microbial endogenous ligands. In this review, we summarize the current state of the knowledge on the involvement of rafts in TLR4 signaling, with an emphasis on how the raft proteins regulate the TLR4 signaling pathways. CD14-bearing rafts, and possibly CD36-rich rafts, are believed to be preferred sites of the assembly of a multimolecular complex which mediates the endocytosis of activated TLR4.
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Affiliation(s)
- Agnieszka Płóciennikowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Aneta Hromada-Judycka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Kinga Borzęcka
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland.
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15
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Assi E, Cazzato D, De Palma C, Perrotta C, Clementi E, Cervia D. Sphingolipids and brain resident macrophages in neuroinflammation: an emerging aspect of nervous system pathology. Clin Dev Immunol 2013; 2013:309302. [PMID: 24078816 PMCID: PMC3775448 DOI: 10.1155/2013/309302] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/01/2013] [Indexed: 12/25/2022]
Abstract
Sphingolipid metabolism is deeply regulated along the differentiation and development of the central nervous system (CNS), and the expression of a peculiar spatially and temporarily regulated sphingolipid pattern is essential for the maintenance of the functional integrity of the nervous system. Microglia are resident macrophages of the CNS involved in general maintenance of neural environment. Modulations in microglia phenotypes may contribute to pathogenic forms of inflammation. Since defects in macrophage/microglia activity contribute to neurodegenerative diseases, it will be essential to systematically identify the components of the microglial cell response that contribute to disease progression. In such complex processes, the sphingolipid systems have recently emerged to play important roles, thus appearing as a key new player in CNS disorders. This review provides a rationale for harnessing the sphingolipid metabolic pathway as a potential target against neuroinflammation.
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Affiliation(s)
- Emma Assi
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
| | - Denise Cazzato
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
| | - Clara De Palma
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
| | - Cristiana Perrotta
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
| | - Emilio Clementi
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
- E. Medea Scientific Institute, 23842 Bosisio Parini, Italy
| | - Davide Cervia
- Department of Biomedical and Clinical Sciences, Unit of Clinical Pharmacology, CNR Institute of Neuroscience, “Luigi Sacco” University Hospital, University of Milan, 20157 Milan, Italy
- Department for Innovation in Biological, Agro-Food and Forest Systems (DIBAF), University of Tuscia, 01100 Viterbo, Italy
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Jung JS, Shin KO, Lee YM, Shin JA, Park EM, Jeong J, Kim DH, Choi JW, Kim HS. Anti-inflammatory mechanism of exogenous C2 ceramide in lipopolysaccharide-stimulated microglia. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1016-26. [PMID: 23384839 DOI: 10.1016/j.bbalip.2013.01.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/17/2013] [Accepted: 01/28/2013] [Indexed: 01/04/2023]
Abstract
Ceramide is a major molecule among the sphingolipid metabolites which are produced in the brain and other organs and act as intracellular second messengers. Although a variety of physiological roles of ceramide have been reported in the periphery and central nervous systems, the role of ceramide in microglial activation has not been clearly demonstrated. In the present study, we examined the effects of exogenous cell permeable short chain ceramides on microglial activation in vitro and in vivo. We found that C2, C6, and C8 ceramide and C8 ceramide-1-phosphate inhibited iNOS and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated BV2 microglial cells and rat primary microglia. In addition, the administration of C2 ceramide suppressed microglial activation in the brains of LPS-exposed mice. By HPLC and LC/MS/MS analyses, we found that C2 ceramide on its own, rather than its modified form (i.e. ceramide-1-phosphate or long chain ceramides), mainly work by penetrating into microglial cells. Further mechanistic studies by using the most effective C2 ceramide among the short chain ceramides tested, revealed that C2 ceramide exerts anti-inflammatory effects via inhibition of the ROS, MAPKs, PI3K/Akt, and Jak/STAT pathways with upregulation of PKA and hemeoxygenase-1 expressions. Interestingly, we found that C2 ceramide inhibits TLR4 signaling by interfering with LPS and TLR4 interactions. Therefore, our data collectively suggests the therapeutic potential of short chain ceramides such as C2 for neuroinflammatory disorders such as Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
- Ji-Sun Jung
- Department of Molecular Medicine, Ewha Womans University Medical School, Seoul, Republic of Korea
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17
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Choi HJ, Chung TW, Kim JE, Jeong HS, Joo M, Cha J, Kim CH, Ha KT. Aesculin inhibits matrix metalloproteinase-9 expression via p38 mitogen activated protein kinase and activator protein 1 in lipopolysachride-induced RAW264.7 cells. Int Immunopharmacol 2012; 14:267-74. [DOI: 10.1016/j.intimp.2012.07.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 06/24/2012] [Accepted: 07/20/2012] [Indexed: 11/16/2022]
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18
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Anti-inflammatory mechanism of action of azithromycin in LPS-stimulated J774A.1 cells. Pharmacol Res 2012; 66:357-62. [DOI: 10.1016/j.phrs.2012.06.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/20/2012] [Accepted: 06/20/2012] [Indexed: 11/24/2022]
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19
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Lee J, Lee SJ, Lim KT. CTB glycoprotein (75kDa) inhibits IgE releasing, TNF-α and IL-6 expressed by bisphenol A in vivo and in vitro. Food Chem Toxicol 2012; 50:2109-17. [DOI: 10.1016/j.fct.2012.03.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 03/08/2012] [Accepted: 03/08/2012] [Indexed: 01/09/2023]
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20
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Shupik MA, Vanin AF, Alessenko AV. Interaction of the nitric oxide signaling system with the sphingomyelin cycle and peroxidation on transmission of toxic signal of tumor necrosis factor-α in ischemia-reperfusion. BIOCHEMISTRY (MOSCOW) 2012; 76:1197-209. [PMID: 22117546 DOI: 10.1134/s0006297911110010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review discusses the functional role of nitric oxide in ischemia-reperfusion injury and mechanisms of signal transduction of apoptosis, which accompanies ischemic damage to organs and tissues. On induction of apoptosis an interaction is observed of the nitric oxide signaling system with the sphingomyelin cycle, which is a source of a proapoptotic agent ceramide. Evidence is presented of an interaction of the sphingomyelin cycle enzymes and ceramide with nitric oxide and enzymes synthesizing nitric oxide. The role of a proinflammatory cytokine TNF-α in apoptosis and ischemia-reperfusion and mechanisms of its cytotoxic action, which involve nitric oxide, the sphingomyelin cycle, and lipid peroxidation are discussed. A comprehensive study of these signaling systems provides insight into the molecular mechanism of apoptosis during ischemia and allows us to consider new approaches for treatment of diseases associated with the activation of apoptosis.
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Affiliation(s)
- M A Shupik
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
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21
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Kue CS, Jung MY, Cho D, Kim TS. C6-ceramide enhances Interleukin-12-mediated T helper type 1 cell responses through a cyclooxygenase-2-dependent pathway. Immunobiology 2011; 217:601-9. [PMID: 22112438 DOI: 10.1016/j.imbio.2011.10.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Accepted: 10/25/2011] [Indexed: 12/24/2022]
Abstract
Ceramides, lipid molecules located predominantly within the plasma membrane of a cell, can function as second messengers, and have been known to carry out a number of cellular functions. T helper type 1 (Th1) immune responses are known to be involved in the cellular immunity, which is crucial in the cancer and allergy immunotherapy. This study was designed to evaluate the effects of ceramides on T helper cell responses and their underlying mechanisms. We demonstrated that a cell-permeable C6-ceramide (C6) together with IL-12 enhanced Th1 cell differentiation, whereas C6 alone had no effects, as demonstrated by the increased populations of IFN-γ expressing CD4(+) T cells and the up-regulation of IFN-γ production from CD4(+) T cells. In contrast, C2-ceramide and long chain ceramides (C16 and C24) did not affect the Th1 responses. C6 treatment was shown to increase the expression of T-bet, a master transcription factor of Th1 responses, in a dose-dependent fashion. Furthermore, C6 increased the expression of cyclooxygenase-2 (COX-2) in CD4(+) T cells. The C6-mediated increase of IFN-γ production and IFN-γ expressing CD4(+) T cell populations were significantly suppressed by a COX-2 specific inhibitor (NS-398) in a dose-dependent manner. T-bet expression was also decreased by NS-398 treatment, thereby indicating that C6 ceramide enhances Th1 responses via a COX-2 dependent pathway. This result demonstrates that C6 may be utilized in therapies for the treatment of immune diseases such cancer and allergy by enhancing the Th1 activity.
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Affiliation(s)
- Chin Siang Kue
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
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22
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Lee J, Oh PS, Lim KT. Allergy-related cytokines (IL-4 and TNF-α) are induced by Di(2-ethylhexyl) phthalate and attenuated by plant-originated glycoprotein (75 kDa) in HMC-1 cells. ENVIRONMENTAL TOXICOLOGY 2011; 26:364-372. [PMID: 20082445 DOI: 10.1002/tox.20563] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 11/22/2009] [Accepted: 12/06/2009] [Indexed: 05/28/2023]
Abstract
Phthalate esters as plasticizers have been widespread in the environment and may be associated with development of allergic diseases such as asthma and atopic dermatitis. In this study, we demonstrated that the CTB glycoprotein attenuates allergic reactions caused by di(2-ethylhexyl) phthalate (DEHP) in human mast cells (HMC-1). This experiment evaluated degranulation of histamine and β-hexosaminidase as well as activities of protein kinase C (PKC), stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), activator protein (AP)-1 and interleukin (IL)-4 and tumor necrosis factor (TNF)-α using immunoblotting and reverse transcription-polymerase chain reaction (RT-PCR). Our results revealed that the CTB glycoprotein in the presence of DEHP inhibits degranulation of mast cell, translocation of PKC from cytosol to membrane, and phosphorylation of SAPK/JNK in HMC -1 cells. We also found that the CTB glycoprotein (100 μg mL(-1) ) has suppressive effects on transcriptional activation of AP-1, and on the expression of IL-4 and TNF-α in DEHP-treated HMC-1 cells. We suggest that the CTB glycoprotein inhibits degranulation of mast cells and expressions of cytokines in HMC-1 cells.
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Affiliation(s)
- Jin Lee
- Molecular Biochemistry Laboratory, Biotechnology Research Institute and Center for the Control of Animal Hazards Using Biotechnology (BK21), Chonnam National University, 300 Yongbong-Dong, Gwang-ju 500-757, South Korea
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23
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Lim KT. Inhibitory effect of glycoprotein isolated from Opuntia ficus-indica var. saboten MAKINO on activities of allergy-mediators in compound 48/80-stimulated mast cells. Cell Immunol 2010; 264:78-85. [PMID: 20510397 DOI: 10.1016/j.cellimm.2010.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 05/02/2010] [Accepted: 05/04/2010] [Indexed: 11/15/2022]
Abstract
The present study was performed to investigate the anti-allergy potentials of glycoprotein (90kDa) isolated from Opuntia ficus-indica var. saboten MAKINO (OFI glycoprotein) in vivo (ICR mice) and in vitro (RBL-2H3 cells). At first, to know whether the OFI glycoprotein has an inhibitory ability for allergy in vivo, we evaluated the activities of allergy-related factors such as histamine and beta-hexosaminidase release, lactate dehydrogenase (LDH), and interleukin 4 (IL-4) in compound 48/80 (8 ml/kg BW)-treated ICR mice. After that, we studied to found the effect for anti-allergy in vitro such as nuclear factor kappa B (NF-kappaB) and inducible nitric oxide synthase (iNOS), extracellular signal-regulated kinase (ERK) 1/2, arachidonic acid, and cyclooxygenase-2 (COX-2) in compound 48/80 (5 microg/ml)-treated RBL-2H3 cells. Our results showed that the OFI glycoprotein (5 mg/kg) inhibited histamine and beta-hexosaminidase release, lactate dehydrogenase (LDH), and interleukin 4 (IL-4) in mice serum. Also OFI glycoprotein (25 microg/ml) has suppressive effects on the expression of MAPK (ERK1/2), and on protein expression of anti-allergic proteins (iNOS and COX-2). Thus, we speculate that the OFI glycoprotein is an example of natural compound that blocks anti-allergic signal transduction pathways.
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Affiliation(s)
- Kye-Taek Lim
- Molecular Biochemistry Laboratory, Biotechnology Research Institute, Chonnam National University, Gwang-ju 300, Yongbong-Dong 500-757, Republic of Korea.
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24
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25
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The inhibition of lipopolysaccharide-induced tumor necrosis factor-α and nitric oxide production by Clostridium perfringens α-toxin and its relation to α-toxin-induced intracellular ceramide generation. Int J Med Microbiol 2009; 299:554-62. [DOI: 10.1016/j.ijmm.2009.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 03/04/2009] [Accepted: 04/19/2009] [Indexed: 11/18/2022] Open
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26
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Huang DW, Chung CP, Kuo YH, Lin YL, Chiang W. Identification of compounds in adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) seed hull extracts that inhibit lipopolysaccharide-induced inflammation in RAW 264.7 macrophages. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:10651-10657. [PMID: 19886607 DOI: 10.1021/jf9028514] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We investigated the effects of adlay seed hull (AH) extracts on the lipopolysaccharide-induced inflammatory response in RAW 264.7 macrophages. An AH ethanol extract (AHE) was partitioned into ethyl acetate, n-butanol, and water fractions. Silica gel chromatography of the ethyl acetate fraction yielded 15 subfractions: AHE-Ea-A to AHE-Ea-O. Subfractions AHE-Ea-J, AHE-Ea-K, and AHE-Ea-M had anti-inflammatory activities, as they counteracted the increased cellular production of nitric oxide and prostaglandin E2 induced by lipopolysaccharide by down-regulating inducible nitric oxide synthase and cyclooxygenase 2 expression. Eriodictyol (1), the ceramide (2S,3S,4R)-2-[(2'R)-2'-hydroxytetracosanoyl-amino]-1,3,4-octadecanetriol (2), and p-coumaric acid (3) were found in the subfractions, and the first two compounds appeared to be primarily responsible for the anti-inflammatory activity. This is the first time that eriodictyol (1) and this ceramide (2) have been found in AH, and the anti-inflammatory properties of the AHE-Ea fraction can be attributed, at least in part, to the presence of these two compounds.
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Affiliation(s)
- Din-Wen Huang
- Graduate Institute of Food Science and Technology, Center for Food and Biomolecules, College of Bioresources and Agriculture, National Taiwan University, Taipei 106, Taiwan
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27
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Inhibitory effect of phytoglycoprotein (115 kDa) on the expression of TNF-alpha and interleukin-1beta via inhibition of MAP kinase in primary cultured mouse thymocytes. Biosci Biotechnol Biochem 2009; 73:2196-202. [PMID: 19809186 DOI: 10.1271/bbb.90277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The present study was performed to investigate the anti-inflammatory potential of 115 kDa glycoprotein isolated from Zanthoxylum piperitum DC leaves (ZPDC glycoprotein) in primary cultured mouse thymocytes. To determine whether the ZPDC glycoprotein has inhibitory capacity against inflammation in vitro, we evaluated the activities of inflammation-related factors such as phosphorylations of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) 1/2, and the activities of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in 12-O-tetradecanoylphorbol 13-acetata (PMA, 50 nM)-treated mouse thymocytes. Our results showed that the ZPDC glycoprotein (200 mug/ml) has a suppressive effect on the expression of MAPK (ERK1/2 and p38 MAPK), on mRNA expression of pro-inflammatory cytokines (TNF-alpha and IL-1beta), and on protein expression of pro-inflammatory proteins (iNOS and COX-2). We speculate that the ZPDC glycoprotein is an example of a natural compound that blocks pro-inflammatory signal transduction pathways.
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28
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Kitatani K, Sheldon K, Anelli V, Jenkins RW, Sun Y, Grabowski GA, Obeid LM, Hannun YA. Acid beta-glucosidase 1 counteracts p38delta-dependent induction of interleukin-6: possible role for ceramide as an anti-inflammatory lipid. J Biol Chem 2009; 284:12979-88. [PMID: 19279008 DOI: 10.1074/jbc.m809500200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Activation of protein kinase C (PKC) by the phorbol ester (phorbol 12-myristate 13-acetate) induces ceramide formation through the salvage pathway involving, in part, acid beta-glucosidase 1 (GBA1), which cleaves glucosylceramide to ceramide. Here, we examine the role of the GBA1-ceramide pathway, in regulating a pro-inflammatory pathway initiated by PKC and leading to activation of p38 and induction of interleukin 6 (IL-6). Inhibition of ceramide formation by fumonisin B1 or down-regulation of PKCdelta potentiated PMA-induced activation of p38 in human breast cancer MCF-7 cells. Similarly, knockdown of GBA1 by small interfering RNAs or pharmacological inhibition of GBA1 promoted further activation of p38 after PMA treatment, implicating the GBA1-ceramide pathway in the termination of p38 activation. Knockdown of GBA1 also evoked the hyperproduction of IL-6 in response to 4beta phorbol 12-myristate 13-acetate. On the other hand, increasing cellular ceramide with cell-permeable ceramide treatment resulted in attenuation of the IL-6 response. Importantly, silencing the delta isoform of the p38 family significantly attenuated the hyperproduction of IL-6. Reciprocally, p38delta overexpression induced IL-6 biosynthesis. Thus, the GBA1-ceramide pathway is suggested to play an important role in terminating p38delta activation responsible for IL-6 biosynthesis. Furthermore, the p38delta isoform was identified as a novel and predominant target of ceramide signaling as well as a regulator of IL-6 biosynthesis.
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Affiliation(s)
- Kazuyuki Kitatani
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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29
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Gutierrez MG, Gonzalez AP, Anes E, Griffiths G. Role of lipids in killing mycobacteria by macrophages: evidence for NF-kappaB-dependent and -independent killing induced by different lipids. Cell Microbiol 2008; 11:406-20. [PMID: 19016780 DOI: 10.1111/j.1462-5822.2008.01263.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have shown that several lipids can modulate the macrophage innate immune response against mycobacteria and enhance their killing. Since NF-kappaB is required for mycobacterial killing, we tested the ability of lipids to activate NF-kappaB in uninfected macrophages and those infected with mycobacteria. In uninfected cells, sphingomyelin (SM), phosphatidylinositol-4-phosphate (PIP) and arachidonic acid (AA) enhanced NF-kappaB activation and the cell surface expression of CD69, a macrophage activation marker regulated by NF-kappaB. Sphingosine (Sph), sphingosine-1-phosphate (S1P), diacylglycerol (DAG), eicosapentanoic acid (EPA) and phosphatidyl choline (PC) failed to activate either NF-kappaB or CD69. Ceramide (Cer) activated CD69 expression without activating NF-kappaB. In Mycobacterium smegmatis-infected cells, NF-kappaB was transiently activated in a manner that was enhanced by SM, PIP and AA. In contrast Mycobacterium avium mostly repressed NF-kappaB activation and only SM and AA could induce its partial activation. While lipids that activate NF-kappaB in uninfected cells tend to kill mycobacteria in macrophages Sph and S1P failed to activate NF-kappaB under most conditions but nevertheless enhanced killing of M. smegmatis, M. avium and M. tuberculosis H37Rv. Our results argue that both NF-kappaB-dependent and -independent mechanisms are involved in macrophage killing of mycobacteria and that both mechanisms can be enhanced by selected lipids.
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Affiliation(s)
- Maximiliano Gabriel Gutierrez
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Postfach 102209, 69117 Heidelberg, Germany.
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30
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Li Y, Komai-Koma M, Gilchrist DS, Hsu DK, Liu FT, Springall T, Xu D. Galectin-3 is a negative regulator of lipopolysaccharide-mediated inflammation. THE JOURNAL OF IMMUNOLOGY 2008; 181:2781-9. [PMID: 18684969 DOI: 10.4049/jimmunol.181.4.2781] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Galectin-3 is a beta-galactoside-binding lectin that plays an important role in inflammatory diseases. It also interacts with the surface carbohydrates of many pathogens, including LPS. However, its role in infection is not fully understood. Data presented herein demonstrate for the first time that galectin-3 is a negative regulator of LPS-induced inflammation. Galectin-3 is constitutively produced by macrophages and directly binds to LPS. Galectin-3-deficient macrophages had markedly elevated LPS-induced signaling and inflammatory cytokine production compared with wild-type cells, which was specifically inhibited by the addition of recombinant galectin-3 protein. In contrast, blocking galectin-3 binding sites by using a neutralizing Ab or its ligand, beta-lactose, enhanced LPS-induced inflammatory cytokine expression by wild-type macrophages. In vivo, mice lacking galectin-3 were more susceptible to LPS shock associated with excessive induction of inflammatory cytokines and NO production. However, these changes conferred greater resistance to Salmonella infection. Thus, galectin-3 is a previously unrecognized, naturally occurring, negative regulator of LPS function, which protects the host from endotoxin shock but, conversely, favors Salmonella survival.
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Affiliation(s)
- Yubin Li
- Division of Immunology, Infection and Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK
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31
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Inhibition of prostaglandin and nitric oxide production in lipopolysaccharide-treated RAW 264.7 cells by tanshinones from the roots of Salvia miltiorrhiza bunge. Arch Pharm Res 2008; 31:758-63. [DOI: 10.1007/s12272-001-1223-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 02/24/2008] [Accepted: 04/21/2008] [Indexed: 10/21/2022]
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32
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Erridge C, Kennedy S, Spickett CM, Webb DJ. Oxidized phospholipid inhibition of toll-like receptor (TLR) signaling is restricted to TLR2 and TLR4: roles for CD14, LPS-binding protein, and MD2 as targets for specificity of inhibition. J Biol Chem 2008; 283:24748-59. [PMID: 18559343 DOI: 10.1074/jbc.m800352200] [Citation(s) in RCA: 182] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The generation of reactive oxygen species is a central feature of inflammation that results in the oxidation of host phospholipids. Oxidized phospholipids, such as 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (OxPAPC), have been shown to inhibit signaling induced by bacterial lipopeptide or lipopolysaccharide (LPS), yet the mechanisms responsible for the inhibition of Toll-like receptor (TLR) signaling by OxPAPC remain incompletely understood. Here, we examined the mechanisms by which OxPAPC inhibits TLR signaling induced by diverse ligands in macrophages, smooth muscle cells, and epithelial cells. OxPAPC inhibited tumor necrosis factor-alpha production, IkappaBalpha degradation, p38 MAPK phosphorylation, and NF-kappaB-dependent reporter activation induced by stimulants of TLR2 and TLR4 (Pam3CSK4 and LPS) but not by stimulants of other TLRs (poly(I.C), flagellin, loxoribine, single-stranded RNA, or CpG DNA) in macrophages and HEK-293 cells transfected with respective TLRs and significantly reduced inflammatory responses in mice injected subcutaneously or intraperitoneally with Pam3CSK4. Serum proteins, including CD14 and LPS-binding protein, were identified as key targets for the specificity of TLR inhibition as supplementation with excess serum or recombinant CD14 or LBP reversed TLR2 inhibition by OxPAPC, whereas serum accessory proteins or expression of membrane CD14 potentiated signaling via TLR2 and TLR4 but not other TLRs. Binding experiments and functional assays identified MD2 as a novel additional target of OxPAPC inhibition of LPS signaling. Synthetic phospholipid oxidation products 1-palmitoyl-2-(5-oxovaleryl)-sn-glycero-3-phosphocholine and 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine inhibited TLR2 signaling from approximately 30 microm. Taken together, these results suggest that oxidized phospholipid-mediated inhibition of TLR signaling occurs mainly by competitive interaction with accessory proteins that interact directly with bacterial lipids to promote signaling via TLR2 or TLR4.
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Affiliation(s)
- Clett Erridge
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Univesity of Strathclyde, 204 George St., Glasgow G1 1XW, United Kingdom.
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33
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Phytoglycoprotein inhibits interleukin-1β and interleukin-6 via p38 mitogen-activated protein kinase in lipopolysaccharide-stimulated RAW 264.7 cells. Naunyn Schmiedebergs Arch Pharmacol 2008; 377:45-54. [DOI: 10.1007/s00210-007-0253-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
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34
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Topical application of a novel ceramide derivative, K6PC-9, inhibits dust mite extract-induced atopic dermatitis-like skin lesions in NC/Nga mice. Int Immunopharmacol 2007; 7:1589-97. [DOI: 10.1016/j.intimp.2007.08.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 07/20/2007] [Accepted: 08/03/2007] [Indexed: 11/24/2022]
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35
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Kim HJ, Oh JE, Kim SW, Chun YJ, Kim MY. Ceramide induces p38 MAPK-dependent apoptosis and Bax translocation via inhibition of Akt in HL-60 cells. Cancer Lett 2007; 260:88-95. [PMID: 18054155 DOI: 10.1016/j.canlet.2007.10.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 10/16/2007] [Accepted: 10/17/2007] [Indexed: 11/27/2022]
Abstract
Ceramide induces apoptosis through caspase activation, cytochrome c release, and Bax translocation in HL-60 cells. However, the upstream signal transduction pathways that induce Bax translocation during ceramide-mediated apoptosis have not been well defined yet. In this study, the activation of p38 mitogen-activated protein kinase (MAPK) was found to be critical for the induction of apoptosis and subcellular redistribution of Bax. Pharmacological inhibition of p38 MAPK with SB203580 or expression of a dominant-negative p38 MAPK attenuated DNA fragmentation, caspase-3 activation, and Bax translocation in response to ceramide. Overexpression of Akt also led to suppression of Bax translocation to mitochondria during ceramide-induced apoptosis in HL-60 cells. We also provide evidence for cross-talk between p38 MAPK and Akt pathways. Expression of myr-Akt or inhibition of phosphatidylinositol 3-kinase (PI3K) with LY294002 had no effect on p38 MAPK activation by ceramide as assessed by phosphorylation, while inhibition of p38 MAPK by a pharmacological inhibitor or a dominant-negative p38 inhibited Akt dephosphorylation in response to ceramide, suggesting that ceramide-induced p38 MAPK activation negatively regulates the Akt pathway.
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Affiliation(s)
- Hae Jong Kim
- Division of Biochemistry, College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
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Chiba N, Masuda A, Yoshikai Y, Matsuguchi T. Ceramide inhibits LPS-induced production of IL-5, IL-10, and IL-13 from mast cells. J Cell Physiol 2007; 213:126-36. [PMID: 17458900 DOI: 10.1002/jcp.21101] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mast cells are central regulators of allergic inflammation through production of various chemical mediators and cytokines. Bacterial infection occasionally worsens allergic inflammation. Although the exact mechanism of this phenomenon remains unclear, we have previously reported that LPS stimulates mast cells to produce not only pro-inflammatory cytokines, such as IL-6 and TNF-alpha, but also Th2-type cytokines, such as IL-5 and IL-13, and a regulatory cytokine, IL-10. In the present study, we have studied the effect of ceramide on LPS-mediated cytokine production from mast cells, as ceramide modulates various cellular functions in many cell types. Administration of cell-permeable C8 ceramide reduced production of IL-5, IL-10, and IL-13 from LPS-stimulated mouse bone marrow-derived mast cells (BMMCs) apparently through transcriptional inhibition, but did not affect IL-6 or TNF-alpha production. Consistently, LPS-stimulated production of IL-5, IL-10, and IL-13 from BMMCs is significantly enhanced in the presence of fumonisin B1, a de novo ceramide synthesis inhibitor. Interestingly, the same C8 ceramide treatment showed opposite effects on cytokine production from LPS-stimulated macrophages, reducing IL-6 and TNF-alpha while not affecting IL-10 production. C8 ceramide pretreatment significantly reduced LPS-induced Akt phosphorylation in BMMCs, but not in macrophages. Furthermore, pretreatment of BMMCs by wortmannin, a specific inhibitor of PI3 kinase, inhibited LPS-stimulated expression of IL-5, IL-10, and IL-13, but not that of TNF-alpha or IL-6. Thus, ceramide appeared to down-regulate LPS-stimulated production of IL-5, IL-10, and IL-13 from mast cells by inhibiting PI3 kinase-Akt pathway in a cell type-specific manner.
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Affiliation(s)
- Norika Chiba
- Division of Host Defense, Center for Neural Disease and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Rouzer CA, Ivanova PT, Byrne MO, Milne SB, Marnett LJ, Brown HA. Lipid profiling reveals arachidonate deficiency in RAW264.7 cells: Structural and functional implications. Biochemistry 2007; 45:14795-808. [PMID: 17144673 PMCID: PMC2443946 DOI: 10.1021/bi061723j] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycerophospholipids containing arachidonic acid (20:4) serve as the precursors for an array of biologically active lipid mediators, most of which are produced by macrophages. We have applied mass spectrometry-based lipid profiling technology to evaluate the glycerophospholipid structure and composition of two macrophage populations, resident peritoneal macrophages and RAW264.7 cells, with regard to their potential for 20:4-based lipid mediator biosynthesis. Fatty acid analysis indicated that RAW264.7 cells were deficient in 20:4 (10 +/- 1 mol %) compared to peritoneal macrophages (26 +/- 1 mol %). Mass spectrometry of total glycerophospholipids demonstrated a marked difference in the distribution of lipid species, including reduced levels of 20:4-containing lipids, in RAW264.7 cells compared to peritoneal macrophages. Enrichment of RAW264.7 cells with 20:4 increased the fatty acid to 20 +/- 1 mol %. However, the distribution of the incorporated 20:4 remained different from that of peritoneal macrophages. RAW264.7 cells pretreated with granulocyte-macrophage colony stimulating factor followed by lipopolysaccharide and interferon-gamma mobilized similar quantities of 20:4 and produced similar amounts of prostaglandins as peritoneal macrophages treated with LPS alone. LPS treatment resulted in detectable changes in specific 20:4-containing glycerophospholipids in peritoneal cells, but not in RAW264.7 cells. 20:4-enriched RAW264.7 cells lost 88% of the incorporated fatty acid during the LPS incubation without additional prostaglandin synthesis. These results illustrate that large differences in glycerophospholipid composition may exist, even in closely related cell populations, and demonstrate the importance of interpreting the potential for lipid-mediator biosynthesis in the context of overall glycerophospholipid composition.
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Affiliation(s)
- Carol A. Rouzer
- Department of Biochemistry, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
| | - Pavlina T. Ivanova
- Department of Pharmacology, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
| | - Mark O. Byrne
- Department of Pharmacology, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
| | - Stephen B. Milne
- Department of Pharmacology, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
| | - Lawrence J. Marnett
- Department of Biochemistry, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
- Department of Chemistry, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
| | - H. Alex Brown
- Department of Pharmacology, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
- Department of Chemistry, the Vanderbilt Institute of Chemical Biology, the Vanderbilt Ingram Cancer Center, Center in Molecular Toxicology, Center for Pharmacology and Drug Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146 USA
- To whom correspondence should be addressed. Tel: (615) 936-3888. Fax: (615) 936-6833.
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Kitatani K, Idkowiak-Baldys J, Bielawski J, Taha TA, Jenkins RW, Senkal CE, Ogretmen B, Obeid LM, Hannun YA. Protein Kinase C-induced Activation of a Ceramide/Protein Phosphatase 1 Pathway Leading to Dephosphorylation of p38 MAPK. J Biol Chem 2006; 281:36793-802. [PMID: 17030510 DOI: 10.1074/jbc.m608137200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently we showed that, in human breast cancer cells, activation of protein kinase C by 4beta-phorbol 12-myristate 13-acetate (PMA) produced ceramide formed from the salvage pathway (Becker, K. P., Kitatani, K., Idkowiak-Baldys, J., Bielawski, J., and Hannun, Y. A. (2005) J. Biol. Chem. 280, 2606-2612). In this study, we investigated intracellular signaling events mediated by this novel activated pathway of ceramide generation. PMA treatment resulted in transient activation of mitogen-activated protein kinases (ERK1/2, JNK1/2, and p38) followed by dephosphorylation/inactivation. Interestingly, fumonisin B1 (FB1), an inhibitor of the salvage pathway, attenuated loss of phosphorylation of p38, suggesting a role for ceramide in p38 dephosphorylation. This was confirmed by knock-down of longevity-assurance homologue 5, which partially suppressed the formation of C(16)-ceramide induced by PMA and increased the phosphorylation of p38. These results demonstrate a role for the salvage pathway in feedback inhibition of p38. To determine which protein phosphatases act in this pathway, specific knock-down of serine/threonine protein phosphatases was performed, and it was observed that knock-down of protein phosphatase 1 (PP1) catalytic subunits significantly increased p38 phosphorylation, suggesting activation of PP1 results in an inhibitory effect on p38. Moreover, PMA recruited PP1 catalytic subunits to mitochondria, and this was significantly suppressed by FB1. In addition, phospho-p38 resided in PMA-stimulated mitochondria. Upon PMA treatment, a mitochondria-enriched/purified fraction exhibited significant increases in C(16)-ceramide, a major ceramide specie, which was suppressed by FB1. Taken together, these data suggest that accumulation of C(16)-ceramide in mitochondria formed from the protein kinase C-dependent salvage pathway results at least in part from the action of longevity-assurance homologue 5, and the generated ceramide modulates the p38 cascade via PP1.
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Affiliation(s)
- Kazuyuki Kitatani
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Walton KA, Gugiu BG, Thomas M, Basseri RJ, Eliav DR, Salomon RG, Berliner JA. A role for neutral sphingomyelinase activation in the inhibition of LPS action by phospholipid oxidation products. J Lipid Res 2006; 47:1967-74. [PMID: 16775254 DOI: 10.1194/jlr.m600060-jlr200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies from our laboratory and others presented evidence that oxidized 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphatidylcholine (OxPAPC) and oxidized 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphatidylethanolamine can inhibit lipopolysaccharide (LPS)-mediated induction of interleukin-8 (IL-8) in endothelial cells. Using synthetic derivatives of phosphatidylethanolamine, we now demonstrate that phospholipid oxidation products containing alpha,beta-unsaturated carboxylic acids are the most active inhibitors we examined. 5-Keto-6-octendioic acid ester of 2-phosphatidylcholine (KOdiA-PC) was 500-fold more inhibitory than OxPAPC, being active in the nanomolar range. Our studies in human aortic endothelial cells identify one important mechanism of the inhibitory response as involving the activation of neutral sphingomyelinase. There is evidence that Toll-like receptor-4 and other members of the LPS receptor complex must be colocalized to the caveolar/lipid raft region of the cell, where sphingomyelin is enriched, for effective LPS signaling. Previous work from our laboratory suggested that OxPAPC could disrupt this caveolar fraction. These studies present evidence that OxPAPC activates sphingomyelinase, increasing the levels of 16:0, 22:0, and 24:0 ceramide and that the neutral sphingomyelinase inhibitor GW4869 reduces the inhibitory effect of OxPAPC and KOdiA-PC. We also show that cell-permeant C6 ceramide, like OxPAPC, causes the inhibition of LPS-induced IL-8 synthesis and alters caveolin distribution similar to OxPAPC. Together, these data identify a new pathway by which oxidized phospholipids inhibit LPS action involving the activation of neutral sphingomyelinase, resulting in a change in caveolin distribution. Furthermore, we identify specific oxidized phospholipids responsible for this inhibition.
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Affiliation(s)
- Kimberly A Walton
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
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40
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El Alwani M, Wu BX, Obeid LM, Hannun YA. Bioactive sphingolipids in the modulation of the inflammatory response. Pharmacol Ther 2006; 112:171-83. [PMID: 16759708 DOI: 10.1016/j.pharmthera.2006.04.004] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 04/06/2006] [Indexed: 12/13/2022]
Abstract
Inflammation is viewed as a protective response against insults to the organism. It involves the recruitment of many cell types and the production of various inflammatory mediators in attempts to contain and reverse the insult. However, inflammation can lead to irreversible tissue destruction by itself and, therefore, can represent a disease state that causes significant morbidity and mortality. Understanding the molecular mechanisms controlling the inflammatory response is essential to formulate therapeutic strategies for the treatment of inflammatory conditions. In fact, substantial research has unveiled important aspects of the inflammatory machinery, both at the cellular and molecular levels. Recently, sphingolipids (SLs) have emerged as signaling molecules that regulate many cell functions, and ample evidence emphasizes their role in the regulation of inflammatory responses. Here, we review the role of bioactive SL as regulators and mediators of inflammatory responses.
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Affiliation(s)
- Mazen El Alwani
- Department of Medicine, Division of General Internal Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
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41
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Zhang YH, Murphy WJ, Russell SW, Morrison DC, Koide N, Yoshida T, Yokochi T. Serum-dependent potentiation of lipopolysaccharide-induced nitric oxide production is mediated by the events after the transcription of inducible type of nitric oxide synthase. Cell Immunol 2005; 234:16-22. [PMID: 15936007 DOI: 10.1016/j.cellimm.2005.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Revised: 04/12/2005] [Accepted: 04/18/2005] [Indexed: 11/25/2022]
Abstract
The mechanism of serum-dependent potentiation of lipopolysaccharide (LPS)-induced nitric oxide (NO) production was studied by incubating mouse macrophage cell line, RAW 264.7, in the presence of fetal bovine serum (FBS). The addition of FBS definitely enhanced LPS-induced NO production through augmented expression of inducible type NO synthase (iNOS) mRNA and protein. However, nuclear run-on analysis demonstrated only marginal enhancement in the rate of LPS-induced iNOS gene transcription in the presence of FBS. Further, there was no significant difference in the luciferase reporter gene activity linked to the iNOS promoter-enhancer gene in response to LPS between the presence and absence of FBS. FBS-dependent enhancement did not appear to involve the initial step for triggering iNOS transcription in LPS-induced NO production. Rather, FBS was suggested to affect the accumulation and stabilization of iNOS mRNA leading to iNOS protein and NO production by some post-transcriptional regulatory mechanism.
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Affiliation(s)
- Yue H Zhang
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS 66160-7184, USA
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42
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Hassan F, Islam S, Mu MM, Ito H, Koide N, Mori I, Yoshida T, Yokochi T. Lipopolysaccharide Prevents Doxorubicin-Induced Apoptosis in RAW 264.7 Macrophage Cells by Inhibiting p53 Activation. Mol Cancer Res 2005; 3:373-9. [PMID: 16046548 DOI: 10.1158/1541-7786.mcr-05-0046] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effect of lipopolysaccharide on doxorubicin-induced cell death was studied by using mouse RAW 264.7 macrophage cells. Pretreatment with lipopolysaccharide at 10 ng/mL prevented doxorubicin-induced cell death and the inhibition was roughly dependent on the concentration of lipopolysaccharide. Posttreatment with lipopolysaccharide for 1 hour also prevented doxorubicin-induced cell death. Lipopolysaccharide inhibited DNA fragmentation and caspase-3 activation in doxorubicin-treated RAW 264.7 cells, suggesting the prevention of doxorubicin-induced apoptosis. Lipopolysaccharide did not significantly inhibit doxorubicin-induced DNA damage detected by single-cell gel electrophoresis (comet) assay. Lipopolysaccharide definitely inhibited the stabilization and nuclear translocation of p53 in doxorubicin-treated RAW 264.7 cells. Lipopolysaccharide, as well as being an inhibitor of p53, abolished doxorubicin-induced apoptosis. Therefore, p53 was suggested to play a pivotal role in the prevention of doxorubicin-induced apoptosis in RAW 264.7 cells by lipopolysaccharide.
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Affiliation(s)
- Ferdaus Hassan
- Department of Microbiology and Immunology, School of Medicine, Aichi Medical University, Nagakute, Aichi 480-1195, Japan
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43
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Bowdish DME, Davidson DJ, Scott MG, Hancock REW. Immunomodulatory activities of small host defense peptides. Antimicrob Agents Chemother 2005; 49:1727-32. [PMID: 15855488 PMCID: PMC1087655 DOI: 10.1128/aac.49.5.1727-1732.2005] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies have demonstrated that in addition to their antimicrobial activity, cationic host defense peptides, like the human cathelicidin LL-37, perform many activities relating to innate immunity, including the induction or modulation of chemokine and cytokine production, alteration of gene expression in host cells, and inhibition of proinflammatory responses of host cells to bacterial components such as lipopolysaccharide (LPS) in vitro and in vivo. To investigate if these properties are shared by smaller peptides, two cathelicidin peptides derived from bovine neutrophils, the 13-mer indolicidin and Bac2A, a linear 12-amino-acid derivative of bactenecin, were compared to the 37-amino-acid peptide LL-37. Indolicidin, like LL-37, inhibited LPS-induced tumor necrosis factor alpha (TNF-alpha) secretion, even when added up to an hour after the addition of Escherichia coli O111:B4 LPS to the human macrophage/monocyte-like THP-1 cell line. In contrast, Bac2A demonstrated no significant antiendotoxin activity. At low concentrations, indolicidin and LL-37 acted synergistically to suppress LPS-induced production of TNF-alpha. Indolicidin was analogous to LL-37 in its ability to induce the production of the chemokine interleukin-8 (IL-8) in a human bronchial cell line, 16HBE14o(-), but it was unable to induce production of IL-8 in THP-1 cells. In contrast, Bac2A was unable to induce IL-8 in either cell type. Conversely, Bac2A was chemotactic for THP-1 cells at concentrations between 10 and 100 mug/ml, while indolicidin and LL-37 were not chemotactic at these concentrations for THP-1 cells. This indicates that in addition to the potential for direct microbicidal activity, cationic host defense peptides may have diverse and complementary abilities to modulate the innate immune response.
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Affiliation(s)
- Dawn M E Bowdish
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, 2259 Lower Mall Road, Vancouver, British Columbia, Canada V6T 1Z4
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Cario E, Gerken G, Podolsky DK. Toll-like receptor 2 enhances ZO-1-associated intestinal epithelial barrier integrity via protein kinase C. Gastroenterology 2004; 127:224-38. [PMID: 15236188 DOI: 10.1053/j.gastro.2004.04.015] [Citation(s) in RCA: 374] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Protein kinase C (PKC) has been implicated in regulation of intestinal epithelial integrity in response to lumenal bacteria. Intestinal epithelial cells (IECs) constitutively express Toll-like receptor (TLR)2, which contains multiple potential PKC binding sites. The aim of this study was to determine whether TLR2 may activate PKC in response to specific ligands, thus potentially modulating barrier function in IECs. METHODS TLR2 agonist (synthetic bacterial lipopeptide Pam(3)CysSK4, peptidoglycan)-induced activation of PKC-related signaling cascades were assessed by immunoprecipitation, Western blotting, immunofluorescence, and kinase assays-combined with functional transfection studies in the human model IEC lines HT-29 and Caco-2. Transepithelial electrical resistance characterized intestinal epithelial barrier function. RESULTS Stimulation with TLR2 ligands led to activation (phosphorylation, enzymatic activity, translocation) of specific PKC isoforms (PKCalpha and PKCdelta). Phosphorylation of PKC by TLR2 ligands was blocked specifically by transfection with a TLR2 deletion mutant. Ligand-induced activation of TLR2 greatly enhanced transepithelial resistance in IECs, which was prevented by pretreatment with PKC-selective antagonists. This effect correlated with apical tightening and sealing of tight junction (TJ)-associated ZO-1, which was mediated via PKC in response to TLR2 ligands, whereas morphologic changes of occludin, claudin-1, or actin cytoskeleton were not evident. Downstream the endogenous PKC substrate myristoylated alanine-rich C kinase substrate (MARCKS), but not transcriptional factor activator protein-1 (AP-1), was activated significantly on stimulation. CONCLUSIONS The present study provides evidence that PKC is an essential component of the TLR2 signaling pathway with the physiologic consequence of directly enhancing intestinal epithelial integrity through translocation of ZO-1 on activation.
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Affiliation(s)
- Elke Cario
- Division of Gastroenterology and Hepatology, University Hospital of Essen, Germany.
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45
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Bowman CC, Bost KL. Cyclooxygenase-2-mediated prostaglandin E2 production in mesenteric lymph nodes and in cultured macrophages and dendritic cells after infection with Salmonella. THE JOURNAL OF IMMUNOLOGY 2004; 172:2469-75. [PMID: 14764719 DOI: 10.4049/jimmunol.172.4.2469] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although numerous studies have demonstrated the ability of intestinal epithelial cells to produce PGs after infection with wild-type strains of Salmonella, few studies have focused on Salmonella-induced prostanoids in mucosal lymphoid tissues. This is surprising in view of the profound effects PGs can have on the host response. To begin to address PG production at mucosal sites, mice were orally inoculated with Salmonella, and at varying times postinfection cyclooxygenase-2 (COX-2) mRNA expression and PGE(2) synthesis were investigated. COX-2 mRNA expression was highly inducible in the mesenteric lymph nodes, whereas COX-1 mRNA levels were constitutive. PGE(2) production also increased significantly in the mesenteric lymph nodes following exposure to viable Salmonella, but not after exposure to killed bacteria. This increased PGE(2) response could be blocked by treatment of mice with the selective COX-2 inhibitor, celecoxib. Treatment of mice with celecoxib during salmonellosis resulted in increased viable bacteria in the mesenteric lymph nodes by day 3 postinfection. However, celecoxib treatment prolonged the survival of lethally infected animals. In vitro studies demonstrated Salmonella-induced up-regulation of COX-2 mRNA expression and PGE(2) secretion by both macrophages and dendritic cells, which could also be blocked in the presence of celecoxib. Interestingly, exposure of these cultured APCs to viable Salmonella was a much greater stimulus for induction of PGE(2) synthesis than exposure to Salmonella-derived LPS. The present study demonstrates induction of PGE(2) synthesis in mesenteric lymph nodes, macrophages, and dendritic cells after infection with wild-type salmonella.
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MESH Headings
- Administration, Oral
- Animals
- Bone Marrow Cells/enzymology
- Bone Marrow Cells/metabolism
- Celecoxib
- Cells, Cultured
- Cyclooxygenase 2
- Dendritic Cells/enzymology
- Dendritic Cells/metabolism
- Dinoprostone/biosynthesis
- Dinoprostone/metabolism
- Female
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/biosynthesis
- Isoenzymes/genetics
- Isoenzymes/physiology
- Lymph Nodes/enzymology
- Lymph Nodes/metabolism
- Macrophages/enzymology
- Macrophages/metabolism
- Macrophages, Peritoneal/enzymology
- Macrophages, Peritoneal/metabolism
- Mesentery
- Mice
- Mice, Inbred BALB C
- Prostaglandin-Endoperoxide Synthases/biosynthesis
- Prostaglandin-Endoperoxide Synthases/genetics
- Prostaglandin-Endoperoxide Synthases/physiology
- Pyrazoles
- RNA, Messenger/biosynthesis
- Salmonella Infections, Animal/drug therapy
- Salmonella Infections, Animal/enzymology
- Salmonella Infections, Animal/immunology
- Salmonella Infections, Animal/metabolism
- Salmonella typhimurium/immunology
- Sulfonamides/administration & dosage
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Affiliation(s)
- Christal C Bowman
- Department of Biology, University of North Carolina, Charlotte, NC 28223, USA
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46
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Ho FM, Lai CC, Huang LJ, Kuo TC, Chao CM, Lin WW. The anti-inflammatory carbazole, LCY-2-CHO, inhibits lipopolysaccharide-induced inflammatory mediator expression through inhibition of the p38 mitogen-activated protein kinase signaling pathway in macrophages. Br J Pharmacol 2004; 141:1037-47. [PMID: 14980980 PMCID: PMC1574272 DOI: 10.1038/sj.bjp.0705700] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Revised: 11/18/2003] [Accepted: 01/15/2004] [Indexed: 11/09/2022] Open
Abstract
1. The present study was undertaken to investigate the anti-inflammatory effects of a synthetic compound, LCY-2-CHO, on the expression of inducible nitric oxide synthase (iNOS), COX-2, and TNF-alpha in murine RAW264.7 macrophages. 2. Within 1-30 microm, LCY-2-CHO concentration-dependently inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E(2) (PGE(2)), and tumor necrosis factor-alpha (TNF-alpha) formation, with IC(50) values of 2.3, 1, and 0.8 microm, respectively. Accompanying inhibition of LPS-induced iNOS, cyclooxygenase-2 (COX-2), and pro-TNF-alpha proteins was observed. 3. Reverse transcription-polymerase chain reaction (RT-PCR) and promoter analyses indicated that iNOS expression was inhibited at the transcriptional level (IC(50)=2.3 microm), that inhibition of COX-2 expression only partially depended on gene transcription (IC(50)=7.6 microm), and that TNF-alpha transcription was unaffected. 4. Transcriptional assays revealed that activation of AP-1, but not NF-kappaB, was concomitantly blocked by LCY-2-CHO. Our results showed that LCY-2-CHO was capable of interfering with post-transcriptional regulation, altering the stability of COX-2 and TNF-alpha mRNAs. 5. Since the 3'-untranslated region (3' UTR) of both COX-2 and TNF-alpha mRNA contains a p38 mitogen-activated protein kinase (MAPK)-regulated element involved in mRNA stability, we assessed the effect of LCY-2-CHO on p38 MAPK. Our data clearly indicated an inhibition (IC(50)=1.7 microm) of LPS-mediated p38 MAPK activity, but not of extracellular signal-regulated kinase (ERK) or c-Jun N-terminal kinase (JNK) activity. However, kinase assays ruled out a direct inhibition of p38 MAPK action. The selective p38 MAPK inhibitor, SB203580, inhibited the promoter activities of iNOS and COX-2 rather than that of TNF-alpha. 6. In conclusion, LCY-2-CHO downregulates inflammatory iNOS, COX-2, and TNF-alpha gene expression in macrophages through interfering with p38 MAPK and AP-1 activation.
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Affiliation(s)
- Feng-Ming Ho
- Department of Internal Medicine, Tao-Yuan General Hospital, Department of Health, the Executive Yuan, Taiwan
| | - Chih-Chang Lai
- Department of Internal Medicine, Tao-Yuan General Hospital, Department of Health, the Executive Yuan, Taiwan
| | - Li-Jiau Huang
- Graduate Institute of Pharmaceutical Chemistry, China Medical College, Taichung, Taiwan
| | - Tsun Cheng Kuo
- Department of Cosmetic Science, Chia-Nan University of Pharmacy, Tainan, Taiwan
| | - Chien M Chao
- Department of Orthopedics, National Taiwan University College of Medicine, Taipei, Taiwan and
| | - Wan-Wan Lin
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
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47
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Chen CW, Chang YH, Tsi CJ, Lin WW. Inhibition of IFN-gamma-mediated inducible nitric oxide synthase induction by the peroxisome proliferator-activated receptor gamma agonist, 15-deoxy-delta 12,14-prostaglandin J2, involves inhibition of the upstream Janus kinase/STAT1 signaling pathway. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:979-88. [PMID: 12847270 DOI: 10.4049/jimmunol.171.2.979] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been reported to exert anti-inflammatory activities in macrophages by competition for transcriptional coactivators with some transcriptional factors, including NF-kappaB. In the present study the influence of PPARgamma activators on IFN-gamma-elicited macrophage stimulation and signaling cascades was investigated. The results show that IFN-gamma-induced inducible NO synthase (iNOS) gene transcription, iNOS protein induction, and NO production are more sensitive to inhibition by 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) than by the other two PPARgamma agonists, GW1929 and ciglitazone. Delayed addition of 15dPGJ(2) for 2 h resulted in reduced inhibition, suggesting action by 15dPGJ(2) on the upstream signaling cascades. Immunoblotting, DNA binding, and reporter gene assays consistently revealed the inhibitory ability of 15dPGJ(2), but not GW1929 or ciglitazone, on IFN-gamma-elicited signaling cascades, including tyrosine phosphorylation of Janus tyrosine protein kinase 2 and STAT1, DNA binding, and IFN regulatory factor-1 trans-activation of STAT1. These effects of 15dPGJ(2) were not abrogated by the PPARgamma antagonist, bisphenol A diglycidyl ether, indicating the PPARgamma-independent actions. 15dPGJ(2) also attenuated IL-6-induced tyrosine phosphorylation of STAT1 and STAT3 in Hep3B hepatoma cells. Consistent with the inhibitory effect of reactive oxygen species on STAT1 signaling, STAT1 inhibition by 15dPGJ(2) was abrogated by N-acetylcysteine, glutathione, superoxide dismutase, and catalase. Furthermore, 15dPGJ(2)-induced inhibition of STAT1 phosphorylation and NO production still occurred in the presence of peroxovanadate, ruling out the action mechanism of 15dPGJ(2) on tyrosine phosphatase. Taken together, for the first time in this study we demonstrate that 15dPGJ(2) can inhibit cytokine-stimulated Janus kinase 2-STAT signaling through a PPARgamma-independent, reactive oxygen species-dependent mechanism. These data provide a novel molecular mechanism of iNOS inhibition by 15dPGJ(2) and confirm its physiological role in anti-inflammation.
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Affiliation(s)
- Ching-Wen Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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48
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Walton KA, Cole AL, Yeh M, Subbanagounder G, Krutzik SR, Modlin RL, Lucas RM, Nakai J, Smart EJ, Vora DK, Berliner JA. Specific phospholipid oxidation products inhibit ligand activation of toll-like receptors 4 and 2. Arterioscler Thromb Vasc Biol 2003; 23:1197-203. [PMID: 12775576 DOI: 10.1161/01.atv.0000079340.80744.b8] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE We have previously shown that phospholipid oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (ox-PAPC) inhibit lipopolysaccharide (LPS)-induced E-selectin expression and neutrophil binding in human aortic endothelial cells (HAECs). The current studies identify specific phospholipids that inhibit chemokine induction by Toll-like receptor-4 (TLR4) and -2 (TLR2) ligands inECs and macrophages. METHODS AND RESULTS Measurements of interleukin (IL)-8 and monocyte chemotactic protein-1 levels secreted from ox-PAPC- and LPS-cotreated ECs indicate that ox-PAPC inhibits activation of TLR4 by LPS. The effects of IL-1beta and tumor necrosis factor-alpha, which utilize the same intracellular signaling molecules, were not inhibited. Cell fractionation and immunofluorescence analyses demonstrate that LPS induces membrane translocation of the LPS receptor complex to a lipid raft/caveolar fraction in ECs. Ox-PAPC inhibits this translocation and alters caveolin-1 distribution. Supporting an important role for caveolae in LPS action, overexpression of caveolin-1 enhanced LPS-induced IL-8 synthesis. Ox-PAPC also inhibits the effect of TLR2 and TLR4 ligands in human macrophages. CONCLUSIONS These studies report a novel mechanism that involves alterations to lipid raft/caveolar processing, by which specific phospholipid oxidation products inhibit activation by TLR4 and TLR2 ligands. These studies have broader implications for the role of ox-PAPC as a regulator of specific lipid raft/caveolar function.
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Affiliation(s)
- Kimberly A Walton
- Department of Medicine, University of California, Los Angeles, CA 90095-1732, USA
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Cho YH, Lee CH, Kim SG. Potentiation of lipopolysaccharide-inducible cyclooxygenase 2 expression by C2-ceramide via c-Jun N-terminal kinase-mediated activation of CCAAT/enhancer binding protein beta in macrophages. Mol Pharmacol 2003; 63:512-23. [PMID: 12606757 DOI: 10.1124/mol.63.3.512] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ceramide, formed by sphingomyelinase, is involved in the expression of cyclooxygenase-2 (COX-2). This study examines the effect of C2-ceramide (C2), a cell-permeable ceramide analog, on the lipopolysaccharide (LPS)-inducible COX-2 expression and signaling pathways. C2 did not induce COX-2 but potentiated LPS-inducible COX-2 expression in Raw264.7 cells, whereas dihydro-C2 was inactive. Treatment of cells with C2 notably increased LPS-inducible CCAAT/enhancer binding protein (C/EBP) DNA binding. Antibody supershift experiments revealed that LPS-induced C/EBP DNA binding activity depended on C/EBP beta and C/EBP delta but not C/EBP alpha, C/EBP epsilon or CBP/p300. C/EBP beta contributed to C2-enhanced DNA binding activity. 4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl) 1H-imidazole (SB203580), a p38 kinase inhibitor, completely inhibited LPS-inducible and C2-potentiated LPS-inducible COX-2 expression. Enhancement of LPS-inducible COX-2 expression and C/EBP DNA binding by C2 was abrogated in dominant-negative mutant of JNK1 [JNK1(-)] cells. 2'-Amino-3'-methoxyflavone (PD98059) or stable transfection with dominant-negative mutant of MKK1 decreased COX-2 induction by LPS but failed to inhibit C2-enhanced LPS induction of COX-2. Transfection with dominant-negative mutant of C/EBP inhibited the ability of C2 to potentiate the induction of COX-2 by LPS. In LPS-treated cells, C2 enhanced both the nuclear translocation and the expression of LPS-inducible C/EBP beta with an increase in AP-1 DNA binding activity. These enhancements were abolished by JNK1(-) transfection. AP-1 decoy oligonucleotide suppressed C2-potentiated C/EBP beta expression, indicating that AP-1 was responsible for C2-mediated C/EBP beta expression. These results demonstrate that C2 increases C/EBP beta-mediated COX-2 induction by LPS and that the pathway of JNK1 but not ERK1/2 is responsible for C/EBP beta activation involving activator protein-1-mediated enhanced C/EBP beta expression.
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Affiliation(s)
- Yang Hee Cho
- National Research Laboratory (MDT), College of Pharmacy, Seoul National University, Seoul, Korea
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50
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Kleinert H, Schwarz PM, Förstermann U. Regulation of the Expression of Inducible Nitric Oxide Synthase. Biol Chem 2003; 384:1343-64. [PMID: 14669979 DOI: 10.1515/bc.2003.152] [Citation(s) in RCA: 289] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Nitric oxide (NO), generated by the inducible isoform of nitric oxide synthase (iNOS), has been described to have beneficial microbicidal, antiviral, antiparasital, immunomodulatory, and antitumoral effects. However, aberrant iNOS induction at the wrong place or at the wrong time has detrimental consequences and seems to be involved in the pathophysiology of several human diseases. iNOS is primarily regulated at the expression level by transcriptional and post-transcriptional mechanisms. iNOS expression can be induced in many cell types with suitable agents such as bacterial lipopolysaccharides (LPS), cytokines, and other compounds. Pathways resulting in the induction of iNOS expression may vary in different cells or different species. Activation of the transcription factors NF-kappaB and STAT-1alpha, and thereby activation of the iNOS promoter, seems to be an essential step for iNOS induction in most cells. However, at least in the human system, also post-transcriptional mechanism are critically involved in the regulation of iNOS expression. The induction of iNOS can be inhibited by a wide variety of immunomodulatory compounds acting at the transcriptional levels and/or post-transcriptionally.
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Affiliation(s)
- Hartmut Kleinert
- Department of Pharmacology, Johannes Gutenberg University, D-55101 Mainz, Germany
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