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Ehrlich V, Bil W, Vandebriel R, Granum B, Luijten M, Lindeman B, Grandjean P, Kaiser AM, Hauzenberger I, Hartmann C, Gundacker C, Uhl M. Consideration of pathways for immunotoxicity of per- and polyfluoroalkyl substances (PFAS). Environ Health 2023; 22:19. [PMID: 36814257 PMCID: PMC9944481 DOI: 10.1186/s12940-022-00958-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 12/30/2022] [Indexed: 05/02/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) are of public health concern, because of their ubiquitous and extremely persistent occurrence, and depending on their structure, their bio-accumulative, mobile and toxic properties. Human health effects associated with exposure to PFAS include adverse effects on the immune system. In 2020, EFSA (the European Food Safety Authority) defined adverse effects on the immune system as the most critical effect for human health risk assessment, based on reduced antibody responses to childhood vaccines and similar effects observed in experimental animal studies. Likewise, the U.S. EPA (Environmental Protection Agency) considers PFAS-induced immunotoxicity, especially in children, as the critical effect for risk assessment. However, the mechanisms by which antibody concentrations are impacted are not completely understood. Furthermore, other targets of the immune system functions have been reported in the literature. OBJECTIVE The aim of this review is to explore PFAS-associated immune-related effects. This includes, relevant mechanisms that may underlie the observed effects on the immune system, immunosuppression as well as immunoenhancement, such as i) modulation of cell signalling and nuclear receptors, such as NF-κB and PPARs; ii) alteration of calcium signalling and homoeostasis in immune cells; iii) modulation of immune cell populations; iv) oxidative stress and v) impact on fatty acid metabolism & secondary effects on the immune system. METHODS A literature research was conducted using three databases (Web of Science, PubMed, and Scopus), which were searched in July 2021 for relevant studies published in the time frame from 2018 to 2021. In total, 487 publications were identified as potentially eligible and following expert-based judgement, articles relevant for mechanisms of PFAS induced immunotoxicity are discussed. CONCLUSIONS Taken together, we show that there is substantial evidence from both in vitro and in vivo experimental as well as epidemiological studies, supporting that various PFAS, not only PFOA and PFOS, affect multiple aspects of the immune system. Timing of exposure is critical, because the developing immune system is especially vulnerable to toxic insults, resulting in a higher risk of particularly adverse immune effects but also other organs later in life.
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Affiliation(s)
- Veronika Ehrlich
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Wieneke Bil
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Rob Vandebriel
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Berit Granum
- Division of Climate and Environment Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Birgitte Lindeman
- Division of Climate and Environment Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Philippe Grandjean
- Department of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | - Andreas-Marius Kaiser
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Ingrid Hauzenberger
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Christina Hartmann
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Claudia Gundacker
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Maria Uhl
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria.
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Pagliari F, Marafioti MG, Genard G, Candeloro P, Viglietto G, Seco J, Tirinato L. ssRNA Virus and Host Lipid Rearrangements: Is There a Role for Lipid Droplets in SARS-CoV-2 Infection? Front Mol Biosci 2020; 7:578964. [PMID: 33134318 PMCID: PMC7579428 DOI: 10.3389/fmolb.2020.578964] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/03/2020] [Indexed: 12/12/2022] Open
Abstract
Since its appearance, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has immediately alarmed the World Health Organization for its very high contagiousness and the complexity of patient clinical profiles. The worldwide scientific community is today gathered in a massive effort in order to develop safe vaccines and effective therapies in the shortest possible time. Every day, new pieces of SARS-CoV-2 infective puzzle are disclosed. Based on knowledge gained with other related coronaviruses and, more in general, on single-strand RNA viruses, we highlight underexplored molecular routes in which lipids and lipid droplets (LDs) might serve essential functions in viral infections. In fact, both lipid homeostasis and the pathways connected to lipids seem to be fundamental in all phases of the coronavirus infection. This review aims at describing potential roles for lipid and LDs in host-virus interactions and suggesting LDs as new and central cellular organelles to be investigated as potential targets against SARS-CoV-2 infection.
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Affiliation(s)
- Francesca Pagliari
- Biomedical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany
| | - Maria Grazia Marafioti
- Biomedical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany
| | - Geraldine Genard
- Biomedical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany
| | - Patrizio Candeloro
- BioNEM Laboratory, Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro, Italy
| | - Giuseppe Viglietto
- Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro, Italy
| | - Joao Seco
- Biomedical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany.,Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Luca Tirinato
- Biomedical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg, Germany.,BioNEM Laboratory, Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro, Italy
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3
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Díaz Acosta CC, Dias AA, Rosa TLSA, Batista-Silva LR, Rosa PS, Toledo-Pinto TG, Costa FDMR, Lara FA, Rodrigues LS, Mattos KA, Sarno EN, Bozza PT, Guilhot C, de Berrêdo-Pinho M, Pessolani MCV. PGL I expression in live bacteria allows activation of a CD206/PPARγ cross-talk that may contribute to successful Mycobacterium leprae colonization of peripheral nerves. PLoS Pathog 2018; 14:e1007151. [PMID: 29979790 PMCID: PMC6056075 DOI: 10.1371/journal.ppat.1007151] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 07/23/2018] [Accepted: 06/11/2018] [Indexed: 01/24/2023] Open
Abstract
Mycobacterium leprae, an obligate intracellular bacillus, infects Schwann cells (SCs), leading to peripheral nerve damage, the most severe leprosy symptom. In the present study, we revisited the involvement of phenolic glycolipid I (PGL I), an abundant, private, surface M. leprae molecule, in M. leprae-SC interaction by using a recombinant strain of M. bovis BCG engineered to express this glycolipid. We demonstrate that PGL I is essential for bacterial adhesion and SC internalization. We also show that live mycobacterium-producing PGL I induces the expression of the endocytic mannose receptor (MR/CD206) in infected cells in a peroxisome proliferator-activated receptor gamma (PPARγ)-dependent manner. Of note, blocking mannose recognition decreased bacterial entry and survival, pointing to a role for this alternative recognition pathway in bacterial pathogenesis in the nerve. Moreover, an active crosstalk between CD206 and the nuclear receptor PPARγ was detected that led to the induction of lipid droplets (LDs) formation and prostaglandin E2 (PGE2), previously described as fundamental players in bacterial pathogenesis. Finally, this pathway was shown to induce IL-8 secretion. Altogether, our study provides evidence that the entry of live M. leprae through PGL I recognition modulates the SC phenotype, favoring intracellular bacterial persistence with the concomitant secretion of inflammatory mediators that may ultimately be involved in neuroinflammation. Nerve damage is the most severe symptom of leprosy, an ancient disease that continues to be a major health problem in several countries. Nerve damage is due to the ability of Mycobacterium leprae, the etiologic agent, to invade SCs, the glial cells of the peripheral nervous system. Understanding the molecular basis of M. leprae–SC interaction is essential for the creation of new tools aiming to treat and, above all, prevent leprosy neuropathy. This study demonstrates the critical role of PGL I, an M. leprae-abundant specific cell wall lipid, in establishing infection. PGL I is not only a prerequisite in initiating bacterial adhesion to and subsequent invasion of SCs, but also for changing the repertoire of cell surface proteins to allow for the entrance of bacteria via alternative pathways. These new invasive pathways induced by PGL I involve recognition of other bacterial cell surface glycolipids that, in turn, evoke functional changes in the infected cell, including the accumulation of host cell-derived lipids, which favor bacterial survival. These pathways also promote the secretion of inflammatory mediators that may contribute to nerve damage. In an era of translational-oriented research, exploring these receptors in depth could lead to the development of attractive strategies to ensure the targeted intracellular delivery of therapeutics aiming to prevent neuropathy.
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Affiliation(s)
| | - André Alves Dias
- Laboratory of Cellular Microbiology, Oswaldo Cruz Institute, Rio de Janeiro, RJ, Brazil
| | | | | | | | | | | | - Flávio Alves Lara
- Laboratory of Cellular Microbiology, Oswaldo Cruz Institute, Rio de Janeiro, RJ, Brazil
| | | | | | | | - Patrícia Torres Bozza
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Rio de Janeiro, RJ, Brazil
| | - Christophe Guilhot
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
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Ballester M, Puig-Oliveras A, Castelló A, Revilla M, Fernández AI, Folch JM. Association of genetic variants and expression levels of porcine FABP4 and FABP5 genes. Anim Genet 2017; 48:660-668. [PMID: 29076225 DOI: 10.1111/age.12620] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2017] [Indexed: 12/31/2022]
Abstract
The FABP4 and FABP5 genes, coding for fatty acid transport proteins, have long been studied as positional candidate genes for SSC4 QTL affecting fat deposition and composition traits in pigs. Polymorphisms in these genes, FABP4:g.2634_2635insC and FABP5:g.3000T>G, have previously been associated with fatness traits in an Iberian by Landrace cross (IBMAP). The aim of the present work was to evaluate the functional implication of these genetic variants. For this purpose, FABP4 and FABP5 mRNA expression levels in 114 BC1_LD animals (25% Iberian × 75% Landrace) were analyzed using real-time quantitative PCR in backfat and muscle. FABP4 gene expression in backfat, but not in muscle, was associated with FABP4:g.2634_2635insC. In contrast, FABP5:g.3000T>G was not associated with gene expression levels. An expression-based genome-wide association study highlighted the FABP4:g.2634_2635insC polymorphism as the polymorphism most associated with FABP4 gene expression in backfat. Furthermore, other genomic regions associated in trans with the mRNA expression of FABP4 in backfat and FABP5 in muscle were also identified. Finally, two putative transcription binding sites for PPARG and NR4A2 may be affected by the FABP4:g.2634_2635insC polymorphism, modifying FABP4 gene expression. Our results reinforce FABP4 as a candidate gene for fatness traits on SSC4.
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Affiliation(s)
- M Ballester
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Genètica i Millora Animal, IRTA, Torre Marimon, 08140, Caldes de Montbui, Spain
| | - A Puig-Oliveras
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - A Castelló
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - M Revilla
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - A I Fernández
- Departamento de Genética Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28040, Madrid, Spain
| | - J M Folch
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, 08193, Barcelona, Spain.,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, 08193, Barcelona, Spain
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Zhang SY, Shao D, Liu H, Feng J, Feng B, Song X, Zhao Q, Chu M, Jiang C, Huang W, Wang X. Metabolomics analysis reveals that benzo[a]pyrene, a component of PM 2.5, promotes pulmonary injury by modifying lipid metabolism in a phospholipase A2-dependent manner in vivo and in vitro. Redox Biol 2017; 13:459-469. [PMID: 28715731 PMCID: PMC5512213 DOI: 10.1016/j.redox.2017.07.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/26/2017] [Accepted: 07/02/2017] [Indexed: 12/17/2022] Open
Abstract
Particulate matter with an aerodynamic diameter less than 2.5μM (PM2.5) is one of the major environmental pollutants in China. In this study, we carried out a metabolomics profile study on PM2.5-induced inflammation. PM2.5 from Beijing, China, was collected and given to rats through intra-tracheal instillation in vivo. Acute pulmonary injury were observed by pulmonary function assessment and H.E. staining. The lipid metabolic profile was also altered with increased phospholipid and sphingolipid metabolites in broncho-alveolar lavage fluid (BALF) after PM2.5 instillation. Organic component analysis revealed that benzo[a]pyrene (BaP) is one of the most abundant and toxic components in the PM2.5 collected on the fiber filter. In vitro, BaP was used to treat A549 cells, an alveolar type II cell line. BaP (4μM, 24h) induced inflammation in the cells. Metabolomics analysis revealed that BaP (4μM, 6h) treatment altered the cellular lipid metabolic profile with increased phospholipid metabolites and reduced sphingolipid metabolites and free fatty acids (FFAs). The proportion of ω-3 polyunsaturated fatty acid (PUFA) was also decreased. Mechanically, BaP (4μM) increased the phospholipase A2 (PLA2) activity at 4h as well as the mRNA level of Pla2g2a at 12h. The pro-inflammatory effect of BaP was reversed by the cytosolic PLA2 (cPLA2) inhibitor and chelator of intracellular Ca2+. This study revealed that BaP, as a component of PM2.5, induces pulmonary injury by activating PLA2 and elevating lysophosphatidylcholine (LPC) in a Ca2+-dependent manner in the alveolar type II cells.
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Affiliation(s)
- Song-Yang Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China
| | - Danqing Shao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China
| | - Huiying Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China
| | - Juan Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China
| | - Baihuan Feng
- Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, People's Republic of China
| | - Xiaoming Song
- Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, People's Republic of China
| | - Qian Zhao
- Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, People's Republic of China
| | - Ming Chu
- Department of Immunology, School of Basic Medical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Changtao Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China
| | - Wei Huang
- Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, People's Republic of China.
| | - Xian Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, People's Republic of China.
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6
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Cytosolic phospholipase A2 modulates TLR2 signaling in synoviocytes. PLoS One 2015; 10:e0119088. [PMID: 25893499 PMCID: PMC4404349 DOI: 10.1371/journal.pone.0119088] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 01/09/2015] [Indexed: 12/29/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic synovitis leading to destruction of cartilage and bone. PLA2 enzymes are key players in inflammation regulating the release of unsaturated fatty acids such as arachidonic acid (AA), a precursor of pro-inflammatory eicosanoids. Several lines of evidence point to toll-like receptors (TLRs) as drivers of synovitis and joint destruction in RA. However, few studies have addressed the implication of PLA2 activity downstream TLR activation in the synovium. Here, we aimed to characterize PLA2 enzyme involvement in TLR2-induced signaling in synovial fibroblast-like cells. TLRs1-7 and a range of sPLA2, iPLA2 and cPLA2 enzymes were found to be transcriptionally expressed in cultured synoviocytes. Activation of TLR2/1 and TLR2/6 led to phosphorylation of cPLA2α at Ser505, and induced AA release and PGE2 production; effects that were attenuated by cPLA2α inhibitors. In contrast, sPLA2 inhibitors did not affect AA or PGE2 release. cPLA2α inhibitors furthermore attenuated TLR-induced expression of IL-6, IL-8 and COX2. COX1/2 inhibitors attenuated TLR2/6-induced IL-6 transcription and protein production comparable to cPLA2α inhibition. Moreover, exogenously PGE2 added alone induced IL-6 production and completely rescued IL-6 transcription when added simultaneously with FSL-1 in the presence of a cPLA2α inhibitor. Our results demonstrate for the first time that cPLA2α is involved in TLR2/1- and TLR2/6-induced AA release, PGE2 production and pro-inflammatory cytokine expression in synoviocytes, possibly through COX/PGE2-dependent pathways. These findings expand our understanding of cPLA2α as a modulator of inflammatory molecular mechanisms in chronic diseases such as RA.
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7
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Liu Y, Chen LY, Sokolowska M, Eberlein M, Alsaaty S, Martinez-Anton A, Logun C, Qi HY, Shelhamer JH. The fish oil ingredient, docosahexaenoic acid, activates cytosolic phospholipase A₂ via GPR120 receptor to produce prostaglandin E₂ and plays an anti-inflammatory role in macrophages. Immunology 2014; 143:81-95. [PMID: 24673159 DOI: 10.1111/imm.12296] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 03/11/2014] [Accepted: 03/21/2014] [Indexed: 12/13/2022] Open
Abstract
Docosahexaenoic acid (DHA) is one of the major ingredients of fish oil and has been reported to have anti-inflammatory properties mediated through the GPR120 receptor. Whether cytosolic phospholipase A2 (cPLA2 ) and lipid mediators produced from cPLA2 activation are involved in the anti-inflammatory role of DHA in macrophages has not been reported. We report here that DHA and the GPR120 agonist, GW9508, activate cPLA2 and cyclooxygenase 2 (COX-2), and cause prostaglandin E2 (PGE2) release in a murine macrophage cell line RAW264.7 and in human primary monocyte-derived macrophages. DHA and GW9508 activate cPLA2 via GPR120 receptor, G protein Gαq and scaffold protein β-arrestin 2. Extracellular signal-regulated kinase 1/2 activation is involved in DHA- and GW9508-induced cPLA2 activation, but not p38 mitogen-activated protein kinase. The anti-inflammatory role of DHA and GW9508 is in part via activation of cPLA2 , COX-2 and production of PGE2 as a cPLA2 inhibitor or a COX-2 inhibitor partially reverses the DHA- and GW9508-induced inhibition of lipopolysaccharide-induced interleukin-6 secretion. The cPLA2 product arachidonic acid and PGE2 also play an anti-inflammatory role. This effect of PGE2 is partially through inhibition of the nuclear factor-κB signalling pathway and through the EP4 receptor of PGE2 because an EP4 inhibitor or knock-down of EP4 partially reverses DHA inhibition of lipopolysaccharide-induced interleukin-6 secretion. Hence, DHA has an anti-inflammatory effect partially through induction of PGE2.
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Affiliation(s)
- Yueqin Liu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
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8
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Serum specific IgG response to toluene diisocyanate-tissue transglutaminase conjugate in toluene diisocyanate-induced occupational asthmatics. Ann Allergy Asthma Immunol 2014; 113:48-54. [PMID: 24950844 DOI: 10.1016/j.anai.2014.04.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/23/2014] [Accepted: 04/29/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND Tissue transglutaminase (tTG) is a post-translational modifying enzyme located in airway epithelial cells. A potential contribution of serum specific IgG (sIgG) to tTG in airway inflammation of toluene diisocyanate (TDI)-induced occupational asthma (OA) has been suggested. OBJECTIVE To prepare a TDI-tTG conjugate and detect serum specific antibodies in sera of patients with TDI-OA to understand this mechanism. METHODS Ninety-nine patients with TDI-OA, 76 asymptomatic exposed controls, 208 patients with non-OA, and 74 unexposed controls were enrolled for this study. The TDI-tTG conjugate was prepared and confirmed by a native gel. Serum sIgG and/or sIgE antibodies to tTG, TDI-tTG, TDI conjugated to human serum albumin, cytokeratin 19, and serum cytokine levels, such as interleukin-8, transforming growth factor-β1, and tissue inhibitor of metalloproteinase-1, were measured by enzyme-linked immunosorbent assay. The level of interleukin-8 produced from airway epithelial cells (A549) treated with tTG was evaluated to investigate the inflammatory effect of tTG and TDI-tTG. RESULTS In the TDI-OA group, the prevalence of serum sIgG to TDI-tTG (17.2%) was higher than that of sIgG to tTG (11.1%), which were significantly higher than those of the 3 control groups (P < .05 for all groups). TDI-exposed subjects with high levels of serum sIgG to TDI-tTG had a high prevalence of sIgG to cytokeratin 19 and higher serum levels of transforming growth factor-β1 and tissue inhibitor of metalloproteinase-1. The tTG and TDI-tTG dose-dependently increased interleukin-8 production from A549 cells. CONCLUSION These findings suggest that TDI exposure in the workplace binds to tTG to form a conjugate that can induce serum sIgG antibody production, airway inflammation, and airway remodeling in patients with TDI-OA.
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9
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Sokolowska M, Chen LY, Eberlein M, Martinez-Anton A, Liu Y, Alsaaty S, Qi HY, Logun C, Horton M, Shelhamer JH. Low molecular weight hyaluronan activates cytosolic phospholipase A2α and eicosanoid production in monocytes and macrophages. J Biol Chem 2013; 289:4470-88. [PMID: 24366870 DOI: 10.1074/jbc.m113.515106] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Hyaluronan (HA) is the major glycosaminoglycan in the extracellular matrix. During inflammation, there is an increased breakdown of HA, resulting in the accumulation of low molecular weight (LMW) HA and activation of monocytes and macrophages. Eicosanoids, derived from the cytosolic phospholipase A2 group IVA (cPLA2α) activation, are potent lipid mediators also attributed to acute and chronic inflammation. The aim of this study was to determine the effect of LMW HA on cPLA2α activation, arachidonic acid (AA) release, and subsequent eicosanoid production and to examine the receptors and downstream mechanisms involved in these processes in monocytes and differently polarized macrophages. LMW HA was a potent stimulant of AA release in a time- and dose-dependent manner, induced cPLA2α, ERK1/2, p38, and JNK phosphorylation, as well as activated COX2 expression and prostaglandin (PG) E2 production in primary human monocytes, murine RAW 264.7, and wild-type bone marrow-derived macrophages. Specific cPLA2α inhibitor blocked HA-induced AA release and PGE2 production in all of these cells. Using CD44, TLR4, TLR2, MYD88, RHAMM or STAB2 siRNA-transfected macrophages and monocytes, we found that AA release, cPLA2α, ERK1/2, p38, and JNK phosphorylation, COX2 expression, and PGE2 production were activated by LMW HA through a TLR4/MYD88 pathway. Likewise, PGE2 production and COX2 expression were blocked in Tlr4(-/-) and Myd88(-/-) mice, but not in Cd44(-/-) mice, after LMW HA stimulation. Moreover, we demonstrated that LMW HA activated the M1 macrophage phenotype with the unique cPLA2α/COX2(high) and COX1/ALOX15/ALOX5/LTA4H(low) gene and PGE2/PGD2/15-HETE(high) and LXA4(low) eicosanoid profile. These findings reveal a novel link between HA-mediated inflammation and lipid metabolism.
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Affiliation(s)
- Milena Sokolowska
- From the Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland 20892 and
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10
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Sommerfelt RM, Feuerherm AJ, Jones K, Johansen B. Cytosolic phospholipase A2 regulates TNF-induced production of joint destructive effectors in synoviocytes. PLoS One 2013; 8:e83555. [PMID: 24349530 PMCID: PMC3861525 DOI: 10.1371/journal.pone.0083555] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/06/2013] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Rheumatoid arthritis (RA) is an inflammatory disease of the joint characterized by chronic synovitis causing pain, swelling and loss of function due to destruction of cartilage and bone. The complex series of pathological events occurring in RA is largely regulated via excessive production of pro-inflammatory cytokines, the most prominent being tumor necrosis factor (TNF). The objective of this work was to elucidate possible involvement of group IVA cytosolic phospholipase A2 (cPLA2α) in TNF-induced regulation of synovitis and joint destructive effectors in RA, to evaluate the potential of cPLA2α as a future therapeutic target. METHODS The involvement of cPLA2α in tumor necrosis factor (TNF)-induced intracellular signaling cascades in synoviocytes (synovial fibroblast-like cells) was analyzed by arachidonic acid (AA) release assay, synoviocyte enzyme activity assay, gene expression analysis by real-time PCR and ELISA immunoassay for the detection of prostaglandin E2 (PGE2), interleukin 8 (IL8) and stromelysin-1 (MMP3), respectively. RESULTS Inhibitors of cPLA2α enzyme activity (AVX002, ATK) significantly reduced TNF-induced cellular release of AA, PGE2, IL8 and MMP3. This reduction was evident both at transcriptional, protein or metabolite levels. Interestingly, cPLA2α inhibition affected several key points of the arachidonyl cascade; AA-release, cyclooxygenase-2 (COX2) expression and PGE2 production. Furthermore, the results suggest that cPLA2α is subject to transcriptional auto-regulation as inhibition of cPLA2α resulted in reduced PLA2G4A gene expression in TNF-stimulated synoviocytes. CONCLUSIONS cPLA2α appears to be an important regulator of central effectors of inflammation and joint destruction, namely MMP3, IL8, COX2, and PGE2. Decreased transcription of the PLA2G4A and COX2 genes in response to cPLA2α enzyme inhibition further suggest a self-reinforcing effect of cPLA2α inhibition in response to TNF. Collectively, these results support that cPLA2α is an attractive therapeutic target candidate as its inhibition reduces the production of multiple key pro-inflammatory factors involved in RA pathogenesis.
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Affiliation(s)
- Randi M. Sommerfelt
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Astrid J. Feuerherm
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kymry Jones
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Berit Johansen
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
- * E-mail:
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11
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Díaz-Gandarilla JA, Osorio-Trujillo C, Hernández-Ramírez VI, Talamás-Rohana P. PPAR activation induces M1 macrophage polarization via cPLA₂-COX-2 inhibition, activating ROS production against Leishmania mexicana. BIOMED RESEARCH INTERNATIONAL 2013; 2013:215283. [PMID: 23555077 PMCID: PMC3600276 DOI: 10.1155/2013/215283] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 12/06/2012] [Accepted: 12/11/2012] [Indexed: 12/17/2022]
Abstract
Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPAR γ , induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF- α , IL-1 β , and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production.
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Affiliation(s)
- J. A. Díaz-Gandarilla
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional No. 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, 07360 México, DF, Mexico
| | - C. Osorio-Trujillo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional No. 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, 07360 México, DF, Mexico
| | - V. I. Hernández-Ramírez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional No. 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, 07360 México, DF, Mexico
| | - P. Talamás-Rohana
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional No. 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, 07360 México, DF, Mexico
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Singh TSK, Lee S, Kim HH, Choi JK, Kim SH. Perfluorooctanoic acid induces mast cell-mediated allergic inflammation by the release of histamine and inflammatory mediators. Toxicol Lett 2012; 210:64-70. [PMID: 22322153 DOI: 10.1016/j.toxlet.2012.01.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 01/18/2012] [Accepted: 01/19/2012] [Indexed: 10/14/2022]
Abstract
Perfluorooctanoic acid (PFOA) has unique physical and chemical characteristics, water and oil repellency, thermal stability, and surfactant properties. PFOA has been regularly found in the blood of animals and humans worldwide, and has become an increasing concern because of its adverse effects in immune system. However, the role of PFOA in the allergic inflammation is not well-known. To further extend the immunotoxicity of PFOA, we examined the role of PFOA on the mast cell-mediated allergic inflammation and studied the possible mechanism of action. PFOA dose- and time-dependently increased histamine release from mast cells and serum histamine by the induction of intracellular calcium. PFOA exacerbated the IgE-dependent local allergic reaction in the mouse allergy model. PFOA induced gene expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 in mast cells. The inducing effect of PFOA on the pro-inflammatory cytokines was nuclear factor-κB, p38 mitogen-activated protein kinase, and caspase-1 dependent. Furthermore, the activation of cyclooxygenase-2 by PFOA suggests the induction of allergic inflammatory mediators by the PFOA. Our findings provide evidence that PFOA, the known immunotoxic agent, induces mast cell-derived allergic inflammatory reactions by histamine release and expression of pro-inflammatory cytokines.
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Affiliation(s)
- Thoudam S K Singh
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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13
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Walters JN, Bickford JS, Beachy DE, Newsom KJ, Herlihy JDH, Peck MV, Qiu X, Nick HS. cPLA(2)α gene activation by IL-1β is dependent on an upstream kinase pathway, enzymatic activation and downstream 15-lipoxygenase activity: a positive feedback loop. Cell Signal 2011; 23:1944-51. [PMID: 21771656 DOI: 10.1016/j.cellsig.2011.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 07/04/2011] [Indexed: 01/01/2023]
Abstract
Cytosolic phospholipase A(2)α (cPLA(2)α) is the most widely studied member of the Group IV PLA(2) family. The enzyme is Ca(2+)-dependent with specificity for phospholipid substrates containing arachidonic acid. As the pinnacle of the arachidonic acid pathway, cPLA(2)α has a primary role in the biosynthesis of a diverse family of eicosanoid metabolites, with potent physiological, inflammatory and pathological consequences. cPLA(2)α activity is regulated by pro-inflammatory stimuli through pathways involving increased intracellular Ca(2+) levels, phosphorylation coupled to increased enzymatic activity and de novo gene transcription. This study addresses the signal transduction pathways for protein phosphorylation and gene induction following IL-1β stimulation in human fetal lung fibroblasts. Our results utilizing both inhibitors and kinase-deficient cells demonstrate that cPLA(2)α is phosphorylated within 10min of IL-1β treatment, an event requiring p38 MAPK as well as the upstream kinase, MKK3/MKK6. Inhibition of p38 MAPK also blocks the phosphorylation of a downstream, nuclear kinase, MSK-1. Our results further demonstrate that the activities of both cPLA(2)α and a downstream lipoxygenase (15-LOX2) are required for IL-1β-dependent induction of cPLA(2)α mRNA expression. Overall, these data support an MKK3/MKK6→p38 MAPK→MSK-1→cPLA(2)α→15-LOX2-dependent, positive feedback loop where a protein's enzymatic activity is required to regulate its own gene induction by a pro-inflammatory stimulus.
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Affiliation(s)
- Jewell N Walters
- Department of Neuroscience, University of Florida, Gainesville, FL 32610, USA
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14
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Bavencoffe A, Kondratskyi A, Gkika D, Mauroy B, Shuba Y, Prevarskaya N, Skryma R. Complex regulation of the TRPM8 cold receptor channel: role of arachidonic acid release following M3 muscarinic receptor stimulation. J Biol Chem 2011; 286:9849-55. [PMID: 21245133 DOI: 10.1074/jbc.m110.162016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cold/menthol-activated TRPM8 (transient receptor potential channel melastatin member 8) is primarily expressed in sensory neurons, where it constitutes the principal receptor of environmental innocuous cold. TRPM8 has been shown to be regulated by multiple influences such as phosphorylation, pH, Ca(2+), and lipid messengers. One such messenger is arachidonic acid (AA), which has been shown to inhibit TRPM8 channel activity. However, the physiological pathways mediating the inhibitory effect of AA on TRPM8 still remain unknown. Here, we demonstrate that TRPM8 is regulated via M3 muscarinic acetylcholine receptor-coupled signaling cascade based on the activation of cytosolic phospholipase A2 (cPLA2) and cPLA2-catalyzed derivation of AA. Stimulation of M3 receptors heterologously co-expressed with TRPM8 in HEK-293 cells by nonselective muscarinic agonist, oxotremorine methiodide (Oxo-M), caused inhibition of TRPM8-mediated membrane current, which could be mimicked by AA and antagonized by pharmacological or siRNA-mediated cPLA2 silencing. Our results demonstrate the intracellular functional link between M3 receptor and TRPM8 channel via cPLA2/AA and suggest a novel physiological mechanism of arachidonate-mediated regulation of TRPM8 channel activity through muscarinic receptors. We also summarize the existing TRPM8 regulations and discuss their physiological and pathological significance.
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Affiliation(s)
- Alexis Bavencoffe
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université des Sciences et Technologies de Lille, F59656 Villeneuve d'Ascq, France
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15
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Barr J, Vázquez-Chantada M, Alonso C, Pérez-Cormenzana M, Mayo R, Galán A, Caballería J, Martín-Duce A, Tran A, Wagner C, Luka Z, Lu SC, Castro A, Le Marchand-Brustel Y, Martínez-Chantar ML, Veyrie N, Clément K, Tordjman J, Gual P, Mato JM. Liquid chromatography-mass spectrometry-based parallel metabolic profiling of human and mouse model serum reveals putative biomarkers associated with the progression of nonalcoholic fatty liver disease. J Proteome Res 2011; 9:4501-12. [PMID: 20684516 DOI: 10.1021/pr1002593] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in most western countries. Current NAFLD diagnosis methods (e.g., liver biopsy analysis or imaging techniques) are poorly suited as tests for such a prevalent condition, from both a clinical and financial point of view. The present work aims to demonstrate the potential utility of serum metabolic profiling in defining phenotypic biomarkers that could be useful in NAFLD management. A parallel animal model/human NAFLD exploratory metabolomics approach was employed, using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) to analyze 42 serum samples collected from nondiabetic, morbidly obese, biopsy-proven NAFLD patients, and 17 animals belonging to the glycine N-methyltransferase knockout (GNMT-KO) NAFLD mouse model. Multivariate statistical analysis of the data revealed a series of common biomarkers that were significantly altered in the NAFLD (GNMT-KO) subjects in comparison to their normal liver counterparts (WT). Many of the compounds observed could be associated with biochemical perturbations associated with liver dysfunction (e.g., reduced Creatine) and inflammation (e.g., eicosanoid signaling). This differential metabolic phenotyping approach may have a future role as a supplement for clinical decision making in NAFLD and in the adaption to more individualized treatment protocols.
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Affiliation(s)
- Jonathan Barr
- OWL Genomics, Bizkaia Technology Park, 48160-Derio, Bizkaia, Spain
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16
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Hatzidaki E, Nakos G, Galiatsou E, Lekka ME. Impaired phospholipases A₂production by stimulated macrophages from patients with acute respiratory distress syndrome. Biochim Biophys Acta Mol Basis Dis 2010; 1802:986-94. [PMID: 20600872 DOI: 10.1016/j.bbadis.2010.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 06/09/2010] [Accepted: 06/11/2010] [Indexed: 01/31/2023]
Abstract
The aim of this study was to investigate whether early phase of acute respiratory distress syndrome (ARDS) is associated with changes in immune response, either systemic or localized to the lung. ARDS and control mechanically ventilated patients, as well as healthy volunteers were studied. Alveolar macrophages (AMΦ) and blood monocytes (BM) were treated ex vivo with lipopolysaccharide (LPS), interferon-γ (IFNγ), and surfactant. Phospholipase A₂ (PLA₂) activity and TLR4 expression were evaluated as markers of cell response. AMΦ from ARDS patients did not respond upon treatment with either LPS or IFN-γ by inducing PLA₂ production. On the contrary, upon stimulation, in control patients the intracellular PLA₂, (mainly cPLA₂) levels were increased, but secretion of PLA₂ (mainly sPLA₂-IIA) was observed only after treatment with LPS. Surfactant suppressed PLA₂ production in cells from both groups of patients. Increased relative changes of total PLA₂ activity and an upregulation of TLR4 expression upon stimulation was observed in BM from primary ARDS, control patients and healthy volunteers. In BM from secondary ARDS patients, however, no PLA₂ induction was observed, with a concomitant down-regulation of TLR4 expression. Cytosolic PLA₂, its activated form, p-cPLA₂, and sPLA₂-IIA were the predominant PLA₂ types within the cells, while extracellularly only sPLA₂-IIA was identified. These results support the concept of down-regulated innate immunity in early ARDS that is compartmentalized in primary and systemic in secondary ARDS. PLA₂ isoforms could serve as markers of the immunity status in ARDS. Finally, our data highlight the role of surfactant in controlling inflammation.
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Affiliation(s)
- Eleana Hatzidaki
- Chemistry Department, University of Ioannina, 45100 Ioannina, Greece
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17
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Rajaram MVS, Brooks MN, Morris JD, Torrelles JB, Azad AK, Schlesinger LS. Mycobacterium tuberculosis activates human macrophage peroxisome proliferator-activated receptor gamma linking mannose receptor recognition to regulation of immune responses. THE JOURNAL OF IMMUNOLOGY 2010; 185:929-42. [PMID: 20554962 DOI: 10.4049/jimmunol.1000866] [Citation(s) in RCA: 199] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mycobacterium tuberculosis enhances its survival in macrophages by suppressing immune responses in part through its complex cell wall structures. Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor superfamily member, is a transcriptional factor that regulates inflammation and has high expression in alternatively activated alveolar macrophages and macrophage-derived foam cells, both cell types relevant to tuberculosis pathogenesis. In this study, we show that virulent M. tuberculosis and its cell wall mannose-capped lipoarabinomannan induce PPARgamma expression through a macrophage mannose receptor-dependent pathway. When activated, PPARgamma promotes IL-8 and cyclooxygenase 2 expression, a process modulated by a PPARgamma agonist or antagonist. Upstream, MAPK-p38 mediates cytosolic phospholipase A(2) activation, which is required for PPARgamma ligand production. The induced IL-8 response mediated by mannose-capped lipoarabinomannan and the mannose receptor is independent of TLR2 and NF-kappaB activation. In contrast, the attenuated Mycobacterium bovis bacillus Calmette-Guérin induces less PPARgamma and preferentially uses the NF-kappaB-mediated pathway to induce IL-8 production. Finally, PPARgamma knockdown in human macrophages enhances TNF production and controls the intracellular growth of M. tuberculosis. These data identify a new molecular pathway that links engagement of the mannose receptor, an important pattern recognition receptor for M. tuberculosis, with PPARgamma activation, which regulates the macrophage inflammatory response, thereby playing a role in tuberculosis pathogenesis.
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Affiliation(s)
- Murugesan V S Rajaram
- Center for Microbial Interface Biology, Ohio State University, Columbus, OH 43210, USA
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Cytosolic phospholipase A2 group IVA is overexpressed in patients with persistent asthma and regulated by the promoter microsatellites. J Allergy Clin Immunol 2010; 125:1393-5. [DOI: 10.1016/j.jaci.2010.02.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 01/13/2010] [Accepted: 02/17/2010] [Indexed: 11/22/2022]
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19
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Naidich M, Shterntal B, Furman R, Pawson AJ, Jabbour HN, Morgan K, Millar RP, Jia J, Tomic M, Stojilkovic S, Stern N, Naor Z. Elucidation of mechanisms of the reciprocal cross talk between gonadotropin-releasing hormone and prostaglandin receptors. Endocrinology 2010; 151:2700-12. [PMID: 20392830 DOI: 10.1210/en.2009-1335] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We recently described a novel GnRH receptor signaling pathway mediated by the prostaglandins (PGs) F(2alpha) and PGI(2), which acts through an autocrine/paracrine modality to limit autoregulation of the GnRH receptor and inhibit LH but not FSH release. Here we further explore the cross talk between GnRH and the PG receptors. GnRH stimulates arachidonic acid (AA) release from LbetaT2 gonadotrope cells via the Ca(2+)-independent phospholipase A(2) (iPLA(2)) and not via the more common Ca(2+)-dependent cytosolic phospholipase A(2)alpha (cPLA(2)alpha). AA release was followed by a marked induction of cyclooxygenase (COX)-1 and COX-2 by GnRH via the protein kinase C/c-Src/phosphatidylinositol 3-kinase/MAPK pathway. COX-2 transcription by GnRH is mediated by the two nuclear factor-kappaB sites and the CCAAT/enhancer-binding protein site within its promoter. Indeed, GnRH stimulates p65/RelA phosphorylation (22-fold) in LbetaT2 cells and the two nuclear factor-kappaB sites apparently act as a composite response element. Although GnRH stimulates cAMP formation in LbetaT2 cells, we found no role for cAMP acting via the cAMP response element site in the COX-2 promoter. PGF(2alpha), PGI(2), or PGE(2) had no effect on GnRH-stimulated ERK, c-Jun N-terminal kinase, and p38MAPK activation or on GnRH- and high K(+)-stimulated intracellular Ca(2+) elevation in LbetaT2 and gonadotropes in primary culture. Although, PGF(2alpha), PGI(2), and PGE(2) reduced GnRH-stimulated cAMP formation, we could not correlate it to the inhibition of GnRH receptor expression, which is exerted only by PGF(2alpha) and PGI(2.) Hence, the inhibition by PGF(2alpha) and PGI(2) of the autoregulation of GnRH receptor expression is most likely mediated via inhibition of GnRH-stimulated phosphoinositide turnover and not by inhibition of Ca(2+) elevation and MAPK activation.
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Affiliation(s)
- Michal Naidich
- Department of Biochemistry, Tel Aviv University, Tel Aviv 69978, Israel
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Buttar NS, DeMars CJ, Lomberk G, Ilyas SI, Bonilla-Velez J, Achra S, Rashtak S, Wang KK, Fernandez-Zapico ME, Urrutia R. Distinct role of Kruppel-like factor 11 in the regulation of prostaglandin E2 biosynthesis. J Biol Chem 2010; 285:11433-44. [PMID: 20154088 PMCID: PMC2857022 DOI: 10.1074/jbc.m109.077065] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 02/02/2010] [Indexed: 12/15/2022] Open
Abstract
Kruppel-like factor (KLF) proteins are emerging as key regulators of lipid metabolism, diabetes, and the biosynthesis of immunological cytokines. However, their role in the synthesis of prostaglandins, widely known biochemical mediators that act in a myriad of cell biological processes remain poorly understood. Consequently, in this study a comprehensive investigation at the cellular, biochemical, and molecular levels reveal that KLF11 inhibits prostaglandin E(2) synthesis via transcriptional silencing of the promoter of its biosynthetic enzyme, cytosolic phospholipase A2alpha. Mechanistically, KLF11 accomplishes this function by binding to the promoter via specific GC-rich sites and recruiting the Sin3-histone deacetylase chromatin remodeling complex. Further functional characterization reveals that this function of KLF11 can be reversed by epidermal growth factor receptor-AKT-mediated post-translational modification of threonine 56, a residue within its Sin3-binding domain. This is the first evidence supporting a relevant role for any KLF protein in doing both: transcriptionally inhibiting prostaglandin biosynthesis and its reversibility by an epidermal growth factor receptor-AKT signaling-mediated posttranslational mechanisms.
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Affiliation(s)
- Navtej S Buttar
- Division of Gastroenterology, Mayo Clinic, Rochester, Minnesota 55902, USA.
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Boyanovsky BB, Li X, Shridas P, Sunkara M, Morris AJ, Webb NR. Bioactive products generated by group V sPLA(2) hydrolysis of LDL activate macrophages to secrete pro-inflammatory cytokines. Cytokine 2010; 50:50-7. [PMID: 20138782 DOI: 10.1016/j.cyto.2009.12.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 12/16/2009] [Accepted: 12/18/2009] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Previous studies have established that hydrolysis of LDL by Group V secretory phospholipase A(2) (GV sPLA(2)) generates a modified particle capable of inducing macrophage foam cell formation. The aim of the present study was to determine whether GV sPLA(2)-hydrolyzed LDL (GV-LDL) produces pro-atherogenic effects in macrophages independent of cholesterol accumulation. METHODS AND RESULTS J-774 cells incubated with GV-LDL produced more TNF-alpha and IL-6 compared to cells incubated with control-LDL. Indirect immunofluorescence showed that GV-LDL but not control-LDL induced nuclear translocation of NFkappaB. Inhibitors of NFkappaB activation, effectively blocked cytokine production induced by GV-LDL. Control-LDL and GV-LDL were separated from albumin present in reaction mixtures by ultracentrifugation. The albumin fraction derived from GV-LDL contained 80% of the FFA generated and was more potent than the re-isolated GV-LDL in inducing pro-inflammatory cytokine secretion. Linoleic acid (18:2) and oleic acid (18:1) were the most abundant FFAs generated, whereas newly formed lyso-PCs contained 14:0 (myristic), 16:1 (palmitic), and 18:2 fatty acyl groups. Experiments with synthetic FFA showed that 18:1 induced J-774 cells to secrete TNF-alpha and IL-6. CONCLUSIONS These results indicate that in addition to promoting atherosclerotic lipid accumulation in macrophages, GV sPLA(2) hydrolysis of LDL leads to activation of NFkappaB, a key regulator of inflammation.
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Affiliation(s)
- Boris B Boyanovsky
- Department of Internal Medicine Endocrinology Division, University of Kentucky, Lexington, 40536, USA.
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Combination Therapy of PPARgamma Ligands and Inhibitors of Arachidonic Acid in Lung Cancer. PPAR Res 2009; 2008:750238. [PMID: 19277204 PMCID: PMC2652614 DOI: 10.1155/2008/750238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 11/26/2008] [Accepted: 12/03/2008] [Indexed: 12/27/2022] Open
Abstract
Lung cancer is the leading cause of cancer death in the United States and five-year survival remains low. Numerous studies have shown that chronic inflammation may lead to progression of carcinogenesis. As a result of inflammatory stimulation, arachidonic acid (AA) metabolism produces proliferation mediators through complex and dynamic interactions of the products of the LOX/COX enzymes. One important mediator in the activation of the AA pathways is the nuclear protein PPARgamma. Targeting LOX/COX enzymes and inducing activation of PPARgamma have resulted in significant reduction of cell growth in lung cancer cell lines. However, specific COX-inhibitors have been correlated with an increased cardiovascular risk. Clinical applications are still being explored with a novel generation of dual LOX/COX inhibitors. PPARgamma activation through synthetic ligands (TZDs) has revealed a great mechanistic complexity since effects are produced through PPARgamma-dependent and -independent mechanisms. Furthermore, PPARgamma could also be involved in regulation of COX-2. Overexpression of PPARgamma has reported to play a role in control of invasion and differentiation. Exploring the function of PPARgamma, in this new context, may provide a better mechanistic model of its role in cancer and give an opportunity to design a more efficient therapeutic approach in combination with LOX/COX inhibitors.
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Multiple roles of phospholipase A2 during lung infection and inflammation. Infect Immun 2008; 76:2259-72. [PMID: 18411286 DOI: 10.1128/iai.00059-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Paruchuri S, Jiang Y, Feng C, Francis SA, Plutzky J, Boyce JA. Leukotriene E4 activates peroxisome proliferator-activated receptor gamma and induces prostaglandin D2 generation by human mast cells. J Biol Chem 2008; 283:16477-87. [PMID: 18411276 DOI: 10.1074/jbc.m705822200] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cysteinyl leukotrienes (cys-LTs) are potent inflammatory lipid mediators, of which leukotriene (LT) E(4) is the most stable and abundant in vivo. Although only a weak agonist of established G protein-coupled receptors (GPCRs) for cys-LTs, LTE(4) potentiates airway hyper-responsiveness (AHR) by a cyclooxygenase (COX)-dependent mechanism and induces bronchial eosinophilia. We now report that LTE(4) activates human mast cells (MCs) by a pathway involving cooperation between an MK571-sensitive GPCR and peroxisome proliferator-activated receptor (PPAR)gamma, a nuclear receptor for dietary lipids. Although LTD(4) is more potent than LTE(4) for inducing calcium flux by the human MC sarcoma line LAD2, LTE(4) is more potent for inducing proliferation and chemokine generation, and is at least as potent for upregulating COX-2 expression and causing prostaglandin D(2) (PGD(2)) generation. LTE(4) caused phosphorylation of extracellular signal-regulated kinase (ERK), p90RSK, and cyclic AMP-regulated-binding protein (CREB). ERK activation in response to LTE(4), but not to LTD(4), was resistant to inhibitors of phosphoinositol 3-kinase. LTE(4)-mediated COX-2 induction, PGD(2) generation, and ERK phosphorylation were all sensitive to interference by the PPARgamma antagonist GW9662 and to targeted knockdown of PPARgamma. Although LTE(4)-mediated PGD(2) production was also sensitive to MK571, an antagonist for the type 1 receptor for cys-LTs (CysLT(1)R), it was resistant to knockdown of this receptor. This LTE(4)-selective receptor-mediated pathway may explain the unique physiologic responses of human airways to LTE(4) in vivo.
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Affiliation(s)
- Sailaja Paruchuri
- Department of Medicine, Division of Rheumatology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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25
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Sokolowska M, Borowiec M, Ptasinska A, Cieslak M, Shelhamer JH, Kowalski ML, Pawliczak R. 85-kDa cytosolic phospholipase A2 group IValpha gene promoter polymorphisms in patients with severe asthma: a gene expression and case-control study. Clin Exp Immunol 2007; 150:124-31. [PMID: 17672871 PMCID: PMC2219277 DOI: 10.1111/j.1365-2249.2007.03459.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cytosolic phospholipase A(2) (cPLA(2)) group IValpha is a critical enzyme involved in the liberation of arachidonic acid from cellular membranes. cPLA(2)(-/-) mice have reduced allergen-induced bronchoconstriction and bronchial hyperresponsiveness. The goal of this study was to investigate polymorphisms of the (CA)(n) and (T)(n) microsatellites and surrounding regions in the cPLA(2)alpha gene promoter. We analysed the cPLA(2) promoter regions containing (CA)(n) and (T)(n) repeats in 87 patients with severe asthma and in 48 control subjects by bidirectional sequencing. Functional studies were performed utilizing reporter genes derived from subjects with varying numbers of these repeats, and on constructs with a series of deletions. We found that the (CA)(n) and (T)(n) regions are polymorphic and that constructs with CA or T repeats or CA and T repeats deleted revealed, respectively, a 41.8 +/- 7%, 22.3 +/- 5% and 100 +/- 20% increase in reporter gene activity. A lower number of CA or T repeats caused higher cPLA(2) promoter luciferase activity. The group of shorter alleles of the (CA)(n) microsatellite region (n = 12-18) (P(cor) = 0.00006), and the group of shorter alleles of (T)(n) repeats region (n = 17-38) (P(cor) = 0.0039) occurred significantly more often in patients with severe asthma. We also found novel SNPs in positions -292 C > G, -185 A > C, -180 T > C and -165 A > C. Two of them were associated with the severe asthma phenotype: -180T allele (P(cor) = 0.03996) and -185 A allele (P(cor) = 0.03966). These results demonstrate that (CA)(n) and (T)(n) repeats may have an influence on cPLA(2) transcription which might play a role in severe asthma pathogenesis.
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Affiliation(s)
- M Sokolowska
- Department of Immunopathology, Medical University of Lodz, Poland
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26
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Bezdecny SA, Karmaus P, Roth RA, Ganey PE. 2,2',4,4'-Tetrachlorobiphenyl upregulates cyclooxygenase-2 in HL-60 cells via p38 mitogen-activated protein kinase and NF-kappaB. Toxicol Appl Pharmacol 2007; 221:285-94. [PMID: 17482227 PMCID: PMC1950673 DOI: 10.1016/j.taap.2007.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 03/15/2007] [Accepted: 03/19/2007] [Indexed: 01/25/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous, persistent environmental contaminants that affect a number of cellular systems, including neutrophils. Among the effects caused by the noncoplanar PCB 2,2',4,4'-tetrachlorobiphenyl (2244-TCB) in granulocytic HL-60 cells are increases in superoxide anion production, activation of phospholipase A(2) with subsequent release of arachidonic acid (AA) and upregulation of the inflammatory gene cyclooxygenase-2 (COX-2). The objective of this study was to determine the signal transduction pathways involved in the upregulation of COX-2 by 2244-TCB. Treatment of HL-60 cells with 2244-TCB led to increased expression of COX-2 mRNA. This increase was prevented by the transcriptional inhibitor actinomycin D in cells pretreated with 2244-TCB for 10 min. The increase in COX-2 mRNA was associated with release of (3)H-AA, phosphorylation of p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinases, increased levels of nuclear NF-kappaB and increased superoxide anion production. Bromoenol lactone, an inhibitor of the calcium-independent phospholipase A(2), reduced (3)H-AA release but had no effect on COX-2 mRNA, protein or activity. Pretreatment with SB-202190 or SB-203580, inhibitors of the p38 MAP kinase pathway, prevented the 2244-TCB-mediated induction of COX-2 and phosphorylation of p38 and ERK MAP kinases. These inhibitors did not alter (3)H-AA release. Treatment with PD 98059 or U 0126, inhibitors of the MAP/ERK (MEK) pathway, prevented the 2244-TCB-mediated activation of ERK but had no effect on COX-2 induction or p38 phosphorylation. 2244-TCB treatment did not affect c-Jun N-terminal kinase (JNK) phosphorylation. 2244-TCB exposure increased the amount of nuclear NF-kappaB. This increase was prevented by pretreatment with p38 MAP kinase inhibitors, but not by pretreatment with MEK inhibitors. Pretreatment with inhibitors of NF-kappaB prevented the 2244-TCB-mediated induction of COX-2 mRNA. 2244-TCB-mediated increases in superoxide anion were prevented by the NADPH oxidase inhibitor apocynin or the free radical scavenger 4-hydroxy TEMPO, but neither of these inhibitors affected the 2244-TCB-induced changes in COX-2 mRNA levels or (3)H-AA release. Taken together these data suggest that p38 MAP kinase-dependent activation of NF-kappaB is critical for the 2244-TCB-mediated upregulation of COX-2 mRNA.
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Affiliation(s)
| | | | | | - Patricia E. Ganey
- Dr. Patricia E. Ganey, Department of Pharmacology and Toxicology, Center for Integrative Toxicology, 214 National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan 48824, E-mail: , Phone: (517) 432-1761, Fax: (517) 432-2310
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27
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Chêne G, Dubourdeau M, Balard P, Escoubet-Lozach L, Orfila C, Berry A, Bernad J, Aries MF, Charveron M, Pipy B. n-3 and n-6 polyunsaturated fatty acids induce the expression of COX-2 via PPARgamma activation in human keratinocyte HaCaT cells. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:576-89. [PMID: 17459764 DOI: 10.1016/j.bbalip.2007.02.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2006] [Revised: 12/31/2006] [Accepted: 02/21/2007] [Indexed: 01/22/2023]
Abstract
Polyunsaturated fatty acids (PUFA) n-3 inhibit inflammation, in vivo and in vitro in keratinocytes. We examined in HaCaT keratinocyte cell line whether eicosapentaenoic acid (EPA) a n-3 PUFA, gamma-linoleic acid (GLA) a n-6 PUFA, and arachidic acid a saturated fatty acid, modulate expression of cyclooxygenase-2 (COX-2), an enzyme pivotal to skin inflammation and reparation. We demonstrate that only treatment of HaCaT with GLA and EPA or a PPARgamma ligand (roziglitazone), induced COX-2 expression (protein and mRNA). Moreover stimulation of COX-2 promoter activity was increased by those PUFAs or rosiglitazone. The inhibitory effects of GW9662 and T0070907 (PPARgamma antagonists), on COX-2 expression and on stimulation of COX-2 promoter activity by EPA and GLA suggest that PPARgamma is implicated in COX-2 induction. Finally, PLA2 inhibitor methyl arachidonyl fluorophosphonate blocked the PUFA effects on COX-2 induction, promoter activity and arachidonic acid mobilization suggesting involvement of AA metabolites in PPAR activation. These findings demonstrate that n-3 and n-6 PUFA increased PPARgamma activity is necessary for the COX-2 induction in HaCaT human keratinocyte cells. Given the anti-inflammatory properties of EPA, we suggest that induction of COX-2 in keratinocytes may be important in the anti-inflammatory and protective mechanism of action of PUFAs n-3 or n-6.
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Affiliation(s)
- Gérald Chêne
- Macrophages, Mediateurs de l'Inflammation et Interactions Cellulaires, Université Paul Sabatier, EA 2405- INSERM IFR 31, Institut Louis Bugnard, BP 84225, 31432 Toulouse CEDEX 4, France
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28
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Naor Z, Jabbour HN, Naidich M, Pawson AJ, Morgan K, Battersby S, Millar MR, Brown P, Millar RP. Reciprocal cross talk between gonadotropin-releasing hormone (GnRH) and prostaglandin receptors regulates GnRH receptor expression and differential gonadotropin secretion. Mol Endocrinol 2006; 21:524-37. [PMID: 17138645 PMCID: PMC1951794 DOI: 10.1210/me.2006-0253] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The asynchronous secretion of gonadotrope LH and FSH under the control of GnRH is crucial for ovarian cyclicity but the underlying mechanism is not fully resolved. Because prostaglandins (PG) are autocrine regulators in many tissues, we determined whether they have this role in gonadotropes. We first demonstrated that GnRH stimulates PG synthesis by induction of cyclooxygenase-2, via the protein kinase C/c-Src/phosphatidylinositol 3'-kinase/MAPK pathway in the LbetaT2 gonadotrope cell line. We then demonstrated that PGF(2alpha) and PGI2, but not PGE2 inhibited GnRH receptor expression by inhibition of phosphoinositide turnover. PGF(2alpha), but not PGI2 or PGE2, reduced GnRH-induction of LHbeta gene expression, but not the alpha-gonadotropin subunit or the FSHbeta subunit genes. The prostanoid receptors EP1, EP2, FP, and IP were expressed in rat gonadotropes. Incubations of rat pituitaries with PGF(2alpha), but not PGI2 or PGE2, inhibited GnRH-induced LH secretion, whereas the cyclooxygenase inhibitor, indomethacin, stimulated GnRH-induced LH secretion. None of these treatments had any effect on GnRH-induced FSH secretion. The findings have thus elaborated a novel GnRH signaling pathway mediated by PGF(2alpha)-FP and PGI2-IP, which acts through an autocrine/paracrine modality to limit autoregulation of the GnRH receptor and differentially inhibit LH and FSH release. These findings provide a mechanism for asynchronous LH and FSH secretions and suggest the use of combination therapies of GnRH and prostanoid analogs to treat infertility, diseases with unbalanced LH and FSH secretion and in hormone-dependent diseases such as prostatic cancer.
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Affiliation(s)
- Zvi Naor
- Medical Research Council (MRC), Huamn Reproduction Sciences, Centre for Reproductive Biology, The Queen's Medical Research Institute, Edinburgh, United Kingdom.
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29
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Schaloske RH, Dennis EA. The phospholipase A2 superfamily and its group numbering system. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1246-59. [PMID: 16973413 DOI: 10.1016/j.bbalip.2006.07.011] [Citation(s) in RCA: 637] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 07/05/2006] [Accepted: 07/29/2006] [Indexed: 01/07/2023]
Abstract
The superfamily of phospholipase A(2) (PLA(2)) enzymes currently consists of 15 Groups and many subgroups and includes five distinct types of enzymes, namely the secreted PLA(2)s (sPLA(2)), the cytosolic PLA(2)s (cPLA(2)), the Ca(2+) independent PLA(2)s (iPLA(2)), the platelet-activating factor acetylhydrolases (PAF-AH), and the lysosomal PLA(2)s. In 1994, we established the systematic Group numbering system for these enzymes. Since then, the PLA(2) superfamily has grown continuously and over the intervening years has required several updates of this Group numbering system. Since our last update, a number of new PLA(2)s have been discovered and are now included. Additionally, tools for the investigation of PLA(2)s and approaches for distinguishing between the different Groups are described.
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Affiliation(s)
- Ralph H Schaloske
- Department of Pharmacology, School of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0601, USA
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Yedgar S, Cohen Y, Shoseyov D. Control of phospholipase A2 activities for the treatment of inflammatory conditions. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1373-82. [PMID: 16978919 DOI: 10.1016/j.bbalip.2006.08.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 08/01/2006] [Indexed: 01/10/2023]
Abstract
Phospholipase-A2 (PLA2) enzymes hydrolyze cell membrane phospholipids to produce arachidonic acid (AA) and lyso-phospholipids (LysoPL), playing a key role in the production of inflammatory lipid mediators, mainly eicosanoids. They are therefore considered pro-inflammatory enzymes and their inhibition has long been recognized as a desirable therapeutic target. However, attempts to develop suitable PLA2 inhibitors for the treatment of inflammatory diseases have yet to succeed. This is due to their functional and structural diversity, and their homeostatic and even anti-inflammatory roles in certain circumstances. In the present review we outline the diversity and functions of PLA2 isoforms, and their interplay in the induction and inhibition of inflammatory processes, with emphasis on discussing approaches for therapeutic manipulation of PLA2 activities.
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Affiliation(s)
- Saul Yedgar
- Department of Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
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31
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Cowan MJ, Coll T, Shelhamer JH. Polyamine-mediated reduction in human airway epithelial migration in response to wounding is PGE2 dependent through decreases in COX-2 and cPLA2 protein levels. J Appl Physiol (1985) 2006; 101:1127-35. [PMID: 16741257 DOI: 10.1152/japplphysiol.01287.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Both ornithine decarboxylase inhibition to deplete polyamines and cyclooxygenase inhibition diminish the migration response to injury of human airway epithelial cells in tissue culture monolayers by approximately 75%. Restoration of normal migration responses is achieved in the polyamine depleted system either by exogenous reconstitution of polyamines or the addition of prostaglandin E(2) (PGE(2)). However, only PGE(2) was able to restore migration in the cyclooxygenase-inhibited systems. Western blot for cyclooxygenase-2 and cytosolic phospholipase A(2) protein levels and ELISAs for PGE(2) secretion demonstrate dramatic increases over 24-48 h after monolayer wounding. These increases are completely abolished by polyamine depletion or cyclooxygenase inhibition. We conclude that polyamine inhibition decreases cellular migration in response to injury in airway epithelial cells at least in part through inhibiting normal PGE(2) production in response to injury. This may be brought about by decreases in cytosolic phospholipase A(2) and cyclooxygenase-2 protein levels.
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Affiliation(s)
- Mark J Cowan
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The University of Maryland, 10 North Greene St., Rm. 3D122, Baltimore, 21201, USA.
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32
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Li J, Lu H, Huang C. NFAT3 is Required for EGF-Induced COX-2 Transcription, but Neither iNOS Transcription Nor Cell Transformation in Cl 41 Cells. Mol Cell Biochem 2006; 289:73-82. [PMID: 16718377 DOI: 10.1007/s11010-006-9149-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2005] [Accepted: 02/03/2006] [Indexed: 10/24/2022]
Abstract
Epidermal growth factor (EGF) has been reported to act as a tumor promoter in several tissues, such as skin, in association with the induction of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). However, molecular mechanisms involved in these regulations are not well defined. This study addressed a potential role of nuclear factor of activated T cells 3 (NFAT3) in EGF-induced COX-2 and iNOS transcription and cell transformation in mouse epidermal Cl 41 cells. We found that EGF markedly induced anchorage-independent growth (cell transformation) of Cl 41 cells, as well as COX-2 (> 6-fold) and iNOS (> 5-fold) promoter-dependent transcription. The EGF-induced COX-2 transcription was blocked by knockdown of NFAT3 with NFAT3 siRNA, whereas the transcription of iNOS and cell transformation induced by EGF were not affected. Although our recent studies supported that NFAT3 plays an essential role in chemical carcinogen benzo[a]pyrene-7,8-diol-9,10-epoxide (B[a]PDE)-induced cell transformation, the data presented here demonstrated that NFAT3 is required for EGF-induced COX-2 transcription, but neither iNOS transcription nor cell transformation, indicating that the role of NFAT3 in regulating cell transformation is carcinogen-specific.
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Affiliation(s)
- Jingxia Li
- Nelson Institute of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, USA
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33
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Ozbay T, Rowan A, Leon A, Patel P, Sewer MB. Cyclic adenosine 5'-monophosphate-dependent sphingosine-1-phosphate biosynthesis induces human CYP17 gene transcription by activating cleavage of sterol regulatory element binding protein 1. Endocrinology 2006; 147:1427-37. [PMID: 16306078 DOI: 10.1210/en.2005-1091] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the human adrenal cortex, ACTH activates steroid hormone biosynthesis by acutely increasing cholesterol delivery to the mitochondrion and chronically increasing the transcription of steroidogenic genes (including CYP17) via a cAMP-dependent pathway. In the present study, we characterized the role of sphingolipids in ACTH-dependent steroidogenesis. H295R human adrenocortical cells were treated with ACTH or dibutyryl cAMP (Bt2cAMP) and the content of several sphingolipid species quantified by mass spectrometry. Both ACTH and Bt2cAMP decreased cellular amounts of several sphingolipids, including sphingomyelin, ceramides, and sphingosine and stimulating the activity of sphingosine kinase and increasing the release of sphingosine-1-phosphate (S1P) into the media. S1P increased CYP17 mRNA expression by promoting the cleavage and nuclear localization of sterol regulatory element binding protein (SREBP) 1. Chromatin immunoprecipitation assays revealed that Bt2cAMP and S1P increased acetylation of histone H3 and promoted binding of SREBP1 to the -520/-331 region of the CYP17 promoter. In summary, our studies demonstrate a role for sphingolipid metabolism and SREBP1 in ACTH-dependent CYP17 regulation and steroidogenesis.
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Affiliation(s)
- Tuba Ozbay
- School of Biology, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, Georgia 30332-0230, USA
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Abstract
Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer related mortality worldwide. The incidence of HCC is rising worldwide, especially in the United States. The overall survival of patients with HCC is grim and currently no efficient secondary prevention or systemic treatments are available. Recent evidence suggests that COX-2 signaling is implicated in hepatocarcinogenesis and COX-2 inhibitors prevent HCC cell growth in vitro and in animal models. However, given the recently reported side effect associated with some of the COX-2 inhibitors, it is imperative to develop chemotherapeutic strategy that simultaneously targets COX-2 and other related key molecules in hepatocarcinogenesis or to utilize agents inhibiting COX-2 signaling in conjunction with other standard chemotherapy or radiation therapy. Such combinational therapeutic approaches are expected to provide synergistic anti-tumor effect with lesser side effect. In this regard, the recently delineated interplay between COX-2-derived PG signaling and other growth-regulatory pathways such as EGFR, Met, iNOS, VEGF and n-3 polyunsaturated fatty acids is expected to provide important therapeutic implications. This review summarizes the recent advances in understanding the mechanisms for COX-2-derived PG signaling in hepatocarcinogenesis and focuses on the newly unveiled interactions between PG cascade and other key signaling pathways that coordinately regulate HCC growth. Understanding these mechanisms and interplays will facilitate the development of more effective chemopreventive and therapeutic strategies.
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Affiliation(s)
- Tong Wu
- Department of Pathology, University of Pittsburgh School of Medicine, MUH E-740, 200 Lothrop Street, Pittsburgh, PA 15213, USA.
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35
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Hurley BP, Williams NL, McCormick BA. Involvement of phospholipase A2 in Pseudomonas aeruginosa-mediated PMN transepithelial migration. Am J Physiol Lung Cell Mol Physiol 2005; 290:L703-L709. [PMID: 16272174 DOI: 10.1152/ajplung.00390.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Inflammation resulting from bacterial infection of the respiratory mucosal surface during pneumonia and cystic fibrosis contributes to pathology. A major consequence of the inflammatory response is recruitment of polymorphonuclear cells (PMNs) to the infected site. To reach the airway, PMNs must travel through several cellular and extracellular barriers, via the actions of multiple cytokines, chemokines, and adhesion molecules. Using a model of polarized lung epithelial cells (A549 or Calu-3) grown on Transwell filters and human PMNs, we have shown that Pseudomonas aeruginosa induces PMN migration across lung epithelial barriers. The process is mediated by epithelial production of the eicosanoid hepoxilin A(3) (HXA(3)) in response to P. aeruginosa infection. HXA(3) is a PMN chemoattractant metabolized from arachidonic acid (AA). Given that release of AA is believed to be the rate-limiting step in generating eicosanoids, we investigated whether P. aeruginosa infection of lung epithelial cells resulted in an increase in free AA. P. aeruginosa infection of A549 or Calu-3 monolayers resulted in a significant increase in [(3)H]AA released from prelabeled lung epithelial cells. This was partially inhibited by PLA(2) inhibitors ONO-RS-082 and ACA as well as an inhibitor of diacylglycerol lipase. Both PLA(2) inhibitors dramatically reduced P. aeruginosa-induced PMN transmigration, whereas the diacylglycerol lipase inhibitor had no effect. In addition, we observed that P. aeruginosa infection caused an increase in the phosphorylation of cytosolic PLA(2) (cPLA(2)), suggesting a mechanism whereby P. aeruginosa activates cPLA(2) generating free AA that may be converted to HXA(3), which is required for mediating PMN transmigration.
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Affiliation(s)
- Bryan P Hurley
- Mucosal Immunology Laboratories, Massachusetts General Hospital, 3503 Charlestown, MA 02129, USA.
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36
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Abstract
Cholangiocarcinoma is a highly malignant epithelial neoplasm arising within the biliary tract and its incidence and mortality is rising. Early diagnosis is difficult and there is presently no effective treatment. Significant progress has been made over the past several years in defining the link between COX-2 and cholangiocarcinogenesis. Selective COX-2 inhibitors have been shown to inhibit cholangiocarcinoma cell growth in vitro and in animal models. However, recently, concerns have been raised about the cardiovascular side effect associated with some COX-2 inhibitors utilized at relatively high dose for antitumor chemoprevention, despite that these inhibitors have a proven safety profile when given as monotherapy to arthritis patients. Therefore, there is an urgent and practical need to develop novel chemopreventive strategy that simultaneously targets COX-2 signaling and other related key molecules in cholangiocarcinogenesis, such as EGFR or utilization of agents inhibiting COX-2 signaling in conjunction with other standard chemotherapy or radiation therapy; these approaches are expected to provide synergistic anti-tumor effect with lesser side effect. In this context, the recently delineated interplay between COX-2-derived PG signaling and other growth-regulatory pathways, such as EGFR, ErbB2, IL-6/GP130, HGF/Met, TGF-beta/Smad, and iNOS is expected to provide important therapeutic implications. This review will summarize the recent advances in understanding the mechanisms for COX-2-derived PG signaling in cholangiocarcinogenesis and focus on the newly unveiled interactions between PG cascade and other key signaling pathways that coordinately regulate cholangiocarcinoma growth. Knowledge on these aspects will help develop more effective therapeutic strategy targeting COX-2 and related key signaling molecules.
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37
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Wu T. Cyclooxygenase-2 and prostaglandin signaling in cholangiocarcinoma. Biochim Biophys Acta Rev Cancer 2005; 1755:135-50. [PMID: 15921858 DOI: 10.1016/j.bbcan.2005.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 04/07/2005] [Accepted: 04/21/2005] [Indexed: 11/25/2022]
Abstract
Cholangiocarcinoma is a highly malignant epithelial neoplasm arising within the biliary tract and its incidence and mortality is rising. Early diagnosis is difficult and there is presently no effective treatment. Significant progress has been made over the past several years in defining the link between COX-2 and cholangiocarcinogenesis. Selective COX-2 inhibitors have been shown to inhibit cholangiocarcinoma cell growth in vitro and in animal models. However, recently, concerns have been raised about the cardiovascular side effect associated with some COX-2 inhibitors utilized at relatively high dose for antitumor chemoprevention, despite that these inhibitors have a proven safety profile when given as monotherapy to arthritis patients. Therefore, there is an urgent and practical need to develop novel chemopreventive strategy that simultaneously targets COX-2 signaling and other related key molecules in cholangiocarcinogenesis, such as EGFR or utilization of agents inhibiting COX-2 signaling in conjunction with other standard chemotherapy or radiation therapy; these approaches are expected to provide synergistic anti-tumor effect with lesser side effect. In this context, the recently delineated interplay between COX-2-derived PG signaling and other growth-regulatory pathways, such as EGFR, ErbB2, IL-6/GP130, HGF/Met, TGF-beta/Smad, and iNOS is expected to provide important therapeutic implications. This review will summarize the recent advances in understanding the mechanisms for COX-2-derived PG signaling in cholangiocarcinogenesis and focus on the newly unveiled interactions between PG cascade and other key signaling pathways that coordinately regulate cholangiocarcinoma growth. Knowledge on these aspects will help develop more effective therapeutic strategy targeting COX-2 and related key signaling molecules.
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Affiliation(s)
- Tong Wu
- Department of Pathology, University of Pittsburgh School of Medicine, MUH E-740, 200 Lothrop Street, Pittsburgh, PA 15213, USA.
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38
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Kawao N, Nagataki M, Nagasawa K, Kubo S, Cushing K, Wada T, Sekiguchi F, Ichida S, Hollenberg MD, MacNaughton WK, Nishikawa H, Kawabata A. Signal transduction for proteinase-activated receptor-2-triggered prostaglandin E2 formation in human lung epithelial cells. J Pharmacol Exp Ther 2005; 315:576-89. [PMID: 16120814 DOI: 10.1124/jpet.105.089490] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated proteinase-activated receptor-2 (PAR(2))-triggered signal transduction pathways causing increased prostaglandin E(2) (PGE(2)) formation in human lung-derived A549 epithelial cells. The PAR(2) agonist, SLIGRL-NH(2) (Ser-Leu-Ile-Gly-Arg-Leu-amide), evoked immediate cytosolic Ca(2+) mobilization and delayed (0.5-3 h) PGE(2) formation. The PAR(2)-triggered PGE(2) formation was attenuated by inhibition of the following signal pathway enzymes: cyclooxygenases 1 and 2 (COX-1 and COX-2, respectively), cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)), the mitogen-activated protein kinases (MAPKs), mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) and p38 MAPK, Src family tyrosine kinase, epidermal growth factor (EGF) receptor tyrosine kinase (EGFRK), and protein kinase C (PKC), but not by inhibition of matrix metalloproteinases. SLIGRL-NH(2) caused prompt (5 min) and transient ERK phosphorylation, blocked in part by inhibitors of PKC and tyrosine kinases but not by an EGFRK inhibitor. SLIGRL-NH(2) also evoked a relatively delayed (15 min) and persistent (30 min) phosphorylation of p38 MAPK, blocked by inhibitors of Src and EGFRK but not by inhibitors of COX-1 or COX-2. SLIGRL-NH(2) elicited a Src inhibitor-blocked prompt (5 min) and transient phosphorylation of the EGFRK. SLIGRL-NH(2) up-regulated COX-2 protein and/or mRNA levels that were blocked by inhibition of p38 MAPK, EGFRK, Src, and COX-2 but not MEK-ERK. SLIGRL-NH(2) also caused COX-1-dependent up-regulation of microsomal PGE synthase-1 (mPGES-1). We conclude that PAR(2)-triggered PGE(2) formation in A549 cells involves a coordinated up-regulation of COX-2 and mPGES-1 involving cPLA(2), increased cytosolic Ca(2+), PKC, Src, MEK-ERK, p38 MAPK, Src-mediated EGF receptor trans-activation, and also metabolic products of both COX-1 and COX-2.
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Affiliation(s)
- Naoyuki Kawao
- Division of Physiology and Pathophysiology, School of Pharmaceutical Sciences, Kinki University, Higashi-Osaka, Japan
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Yan W, Jenkins CM, Han X, Mancuso DJ, Sims HF, Yang K, Gross RW. The Highly Selective Production of 2-Arachidonoyl Lysophosphatidylcholine Catalyzed by Purified Calcium-independent Phospholipase A2γ. J Biol Chem 2005; 280:26669-79. [PMID: 15908428 DOI: 10.1074/jbc.m502358200] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Herein, we report the heterologous expression of the human peroxisomal 63-kDa calcium-independent phospholipase A2gamma (iPLA2gamma) isoform in Sf9 cells, purification of the N-terminal His-tagged enzyme by affinity chromatography, and the identification of its remarkable substrate selectivity that results in the highly selective generation of 2-arachidonoyl lysophosphatidylcholine. Mass spectrometric analyses demonstrated that purified iPLA2gamma hydrolyzed saturated or monounsaturated aliphatic groups readily from either the sn-1 or sn-2 positions of phospholipids. In addition, purified iPLA2gamma effectively liberated arachidonic acid from the sn-2 position of plasmenylcholine substrates. In contrast, incubation of iPLA2gamma with 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine resulted in the rapid release of palmitic acid and the selective accumulation of 2-arachidonoyl lysophosphatidylcholine (LPC), which was not metabolized further by iPLA2gamma. The putative regiospecificity of the 2-arachidonoyl LPC product was authenticated by its diagnostic fragmentation pattern during tandem mass spectrometric analysis. To identify the physiological relevance of iPLA2gamma-mediated 2-arachidonoyl LPC production utilizing naturally occurring membranes, we incubated purified rat hepatic peroxisomes with iPLA2gamma and similarly identified the selective accumulation of 2-arachidonoyl LPC. Furthermore, tandem mass spectrometric analysis demonstrated that 2-arachidonoyl LPC is a natural product in human myocardium, a tissue in which iPLA2gamma expression is robust. Because 2-arachidonoyl LPC represents a key branch point intermediate that can potentially lead to a variety of bioactive molecules in eicosanoid signaling (e.g. arachidonic acid, 2-arachidonoylglycerol), these results have uncovered a novel eicosanoid selective pathway through iPLA2gamma-mediated 2-arachidonoyl LPC production to amplify and diversify the repertoire of biologic lipid second messengers in response to cellular stimulation.
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Affiliation(s)
- Wei Yan
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Parhamifar L, Jeppsson B, Sjölander A. Activation of cPLA 2 is required for leukotriene D 4 -induced proliferation in colon cancer cells. Carcinogenesis 2005; 26:1988-98. [PMID: 15975962 DOI: 10.1093/carcin/bgi159] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It is well documented that prolonged inflammatory conditions, particularly those relating to the colon, have been shown to induce cancer. We have previously demonstrated that the pro-inflammatory mediator leukotriene D(4) (LTD(4)) induces survival and proliferation in intestinal cells and that its receptor, CysLT(1), is upregulated in human colon cancer tissue. Here we demonstrate, for the first time that in both Int 407 (a non-transformed human intestinal epithelial cell line) and Caco-2 cells (a human colorectal carcinoma cell line), cytosolic phospholipase A(2)alpha (cPLA(2)alpha) is activated and translocates to the nucleus upon LTD(4) stimulation via a calcium-dependent mechanism that involves activation of protein kinase C (PKC), and the mitogen-activated protein kinases ERK1/2 and p38. We also show with a cPLA(2)alpha promoter luciferase assay, that LTD(4) induces an increase in the transcriptional activity of cPLA(2)alpha via activation of cPLA(2)alpha and the transcription factor NFkappaB. Interestingly we demonstrate here that both the basal and the LTD(4)-induced cPLA(2)alpha activity is elevated approximately 3-fold in Caco-2 colon cancer cells compared with Int 407 cells. The difference in basal activity was confirmed in human colon tumor samples by the finding of a similar increase in cPLA(2)alpha activity when compared with normal colon tissue. A functional role of the increased cPLA(2)alpha activity in tumor cells was revealed by our findings that inhibition of this enzyme reduced both basal and LTD(4)-induced proliferation, the effects being most pronounced in Caco-2 tumor cells. The present data reveal that cPLA(2)alpha, an important intracellular signal activated by inflammatory mediators, is an important regulator of colon tumor growth.
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Affiliation(s)
- Ladan Parhamifar
- Experimental Pathology, The Department of Laboratory Medicine and Surgery, Lund University, Malmö University Hospital, Malmö, Sweden
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Abstract
PURPOSE OF REVIEW Immunohistochemistry studies have confirmed the presence of group IIA, group V and group X secretory phospholipase A2 in human or mouse atherosclerotic lesions. The possibility that secretory phospholipase A2 plays a role in the pathophysiology of atherosclerosis (and is not merely a marker for localized inflammation) has been substantiated by a number of recent in-vitro and in-vivo studies. RECENT FINDINGS A mouse strain with a targeted deletion of group V secretory phospholipase A2 has been developed. Peritoneal macrophages from these mice have significantly blunted eicosanoid generation in response to zymosan, providing the first direct evidence that a secretory phospholipase A2 plays a role in stimulation-induced arachidonic acid production in vivo. A recent in-vitro study indicated that de novo synthesized groups IIA and X secretory phospholipase A2 can mediate arachidonic acid release intracellularly, without the requirement for previous secretion from cells, as was previously thought. Several studies support the previously proposed model that secretory phospholipase A2 hydrolysis generates pro-atherogenic LDL. These data, coupled with the finding that macrophage-specific expression of human group IIA secretory phospholipase A2 promotes atherosclerotic lipid deposition in mice, draw attention to secretory phospholipase A2 as an attractive target for the treatment of atherosclerotic disease. SUMMARY Secretory phospholipase A2 activity in the arterial intima has the potential to amplify atherogenic processes by liberating potent pro-inflammatory lipid mediators and by generating pro-atherogenic LDL. Future in-vivo studies will aid in defining the mechanism(s) that underlie the pro-atherosclerotic effects of secretory phospholipase A2.
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Affiliation(s)
- Nancy R Webb
- Department of Internal Medicine, University of Kentucky, Lexington, Kentucky 40536-0200, USA.
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Kuwata H, Nonaka T, Murakami M, Kudo I. Search of factors that intermediate cytokine-induced group IIA phospholipase A2 expression through the cytosolic phospholipase A2- and 12/15-lipoxygenase-dependent pathway. J Biol Chem 2005; 280:25830-9. [PMID: 15878884 DOI: 10.1074/jbc.m500168200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Inducible expression of group IIA secretory phospholipase A2 (sPLA2-IIA) by interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNFalpha) is under the control of group IVA cytosolic PLA2alpha and 12/15-lipoxygenase (12/15-LOX) in rat fibroblastic 3Y1 cells. We show here that this cytokine induction of sPLA2-IIA mRNA requires de novo protein synthesis. By means of cDNA array analysis, we found that the level of the CXC chemokine MIP-2 (macrophage inflammatory protein-2) was significantly elevated in 12/15-LOX-transfected cells compared with control cells. IL-1beta/TNFalpha-stimulated induction of endogenous MIP-2 preceded that of sPLA2-IIA, and exogenous MIP-2 induced sPLA2-IIA dose-dependently. Moreover, a MIP-2-specific antisense oligonucleotide and small interfering RNA attenuated the IL-1beta/TNFalpha-induced expression of sPLA2-IIA, suggesting that MIP-2 is an absolute intermediate requirement for optimal induction of sPLA2-IIA. In addition, the expression of c-jun and fra-1, which are components of the transcription factor AP-1, was elevated in 12/15-LOX-transfected cells, in which cytokine-dependent binding of AP-1 to the sPLA2-IIA promoter was increased significantly. Conversely, the receptors for transforming growth factor-beta and platelet-derived growth factor, which contributed to down-regulation of sPLA2-IIA expression, were decreased following 12/15-LOX overexpression. Taken together, 12/15-LOX-dependent up-regulation of sPLA2-IIA expression may result from the interplay between accelerated MIP-2 signaling, AP-1 activation, and attenuated transforming growth factor-beta and platelet-derived growth factor signaling.
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Affiliation(s)
- Hiroshi Kuwata
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Tokyo 142-8555, Japan
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