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Li S, Qin C, Peng SM, Wang YB, Wang Y, Wang XS, Shi JG, Li XC. A newly identified secretory phospholipase A2 group XIIA homolog (LcPLA2XIIA) in Larimichthys crocea exhibits antimicrobial and antitumor activities. FISH & SHELLFISH IMMUNOLOGY 2024:109924. [PMID: 39332653 DOI: 10.1016/j.fsi.2024.109924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Revised: 09/22/2024] [Accepted: 09/24/2024] [Indexed: 09/29/2024]
Abstract
The phospholipase A2 (PLA2) superfamily has attracted increasing attention in recent years due to the multiple physiological and pathological functions exerted by its members. Up to date, the knowledge about the biological role of PLA2XIIA subfamily members remains limited. In this study, a new member of PLA2XIIA subfamily, LcPLA2XIIA, was characterized in large yellow croaker. Different from most members of the PLA2 superfamily with positive charge, LcPLA2XIIA encodes an anionic protein, which is similar to other members of PLA2XIIA subfamily. LcPLA2XIIA is highly expressed in the intestine, and afterwards, it is up-regulated after with Pseudomonas plecoglossicida or Staphylococcus aureus. LcPLA2XIIA exhibits strong inhibitory activity against these two bacteria. The results indicate that LcPLA2XIIA plays an important role in the antimicrobial immune responses of large yellow croaker. LcPLA2XIIA displays strong binding activity to all the tested bacteria. It specifically interacts with LTA, a unique component on the surface of Gram-positive bacteria. It also significantly promotes bacterial agglutination in the presence of Ca2+. These findings reveal that the binding and agglutinating abilities of LcPLA2XIIA to bacteria contribute greatly to its antibacterial activity. In addition, LcPLA2XIIA significantly inhibits the proliferation of infectious hematopoietic necrosis virus instead of recombinant human adenovirus type 5. It also suppresses the growth of human colorectal adenocarcinoma cells by inducing apoptosis, but it has no obvious inhibitory effect on the growth of epithelioma papulosum cyprinid cells. This study provides new insights into the antibacterial activity, and the mechanism of LcPLA2XIIA in large yellow croaker, and antiviral and antitumor functions of PLA2XIIA subfamily members.
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Affiliation(s)
- Shouhu Li
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of Inland Saline-alkaline Aquaculture, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China
| | - Chuang Qin
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of Inland Saline-alkaline Aquaculture, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China
| | - Shi-Ming Peng
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Ya-Bing Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Yuan Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of Inland Saline-alkaline Aquaculture, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China
| | - Xiao-Shan Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Jian-Gao Shi
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China.
| | - Xin-Cang Li
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China; Key Laboratory of Inland Saline-alkaline Aquaculture, Ministry of Agriculture and Rural Affairs, Shanghai 200090, China.
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Murakami M, Sato H, Taketomi Y. Modulation of immunity by the secreted phospholipase A 2 family. Immunol Rev 2023; 317:42-70. [PMID: 37035998 DOI: 10.1111/imr.13205] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Among the phospholipase A2 (PLA2 ) superfamily, which typically catalyzes the sn-2 hydrolysis of phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2 ) family contains 11 isoforms in mammals. Individual sPLA2 s have unique enzymatic specificity toward fatty acids and polar heads of phospholipid substrates and display distinct tissue/cellular distributions, suggesting their distinct physiological functions. Recent studies using knockout and/or transgenic mice for a full set of sPLA2 s have revealed their roles in modulation of immunity and related disorders. Application of mass spectrometric lipidomics to these mice has enabled to identify target substrates and products of individual sPLA2 s in given tissue microenvironments. sPLA2 s hydrolyze not only phospholipids in the plasma membrane of activated, damaged or dying mammalian cells, but also extracellular phospholipids such as those in extracellular vesicles, microbe membranes, lipoproteins, surfactants, and dietary phospholipids, thereby exacerbating or ameliorating various diseases. The actions of sPLA2 s are dependent on, or independent of, the generation of fatty acid- or lysophospholipid-derived lipid mediators according to the pathophysiological contexts. In this review, we make an overview of our current understanding of the roles of individual sPLA2 s in various immune responses and associated diseases.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Hiroyasu Sato
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshitaka Taketomi
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Pungerčar J, Bihl F, Lambeau G, Križaj I. What do secreted phospholipases A 2 have to offer in combat against different viruses up to SARS-CoV-2? Biochimie 2021; 189:40-50. [PMID: 34097986 PMCID: PMC8449419 DOI: 10.1016/j.biochi.2021.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/24/2021] [Accepted: 05/31/2021] [Indexed: 12/09/2022]
Abstract
Secreted phospholipases A2 (sPLA2s) form a widespread group of structurally-related enzymes that catalyse the hydrolysis of the sn-2 ester bond of glycerophospholipids to produce free fatty acids and lysophospholipids. In humans, nine catalytically active and two inactive sPLA2 proteins have been identified. These enzymes play diverse biological roles, including host defence against bacteria, parasites and viruses. Several of these endogenous sPLA2s may play a defensive role in viral infections, as they display in vitro antiviral activity by both direct and indirect mechanisms. However, endogenous sPLA2s may also exert an offensive and negative role, dampening the antiviral response or promoting inflammation in animal models of viral infection. Similarly, several exogenous sPLA2s, most of them from snake venoms and other animal venoms, possess in vitro antiviral activities. Thus, both endogenous and exogenous sPLA2s may be exploited for the development of new antiviral substances or as therapeutic targets for antagonistic drugs that may promote a more robust antiviral response. In this review, the antiviral versus proviral role of both endogenous and exogenous sPLA2s against various viruses including coronaviruses is presented. Based on the highlighted developments in this area of research, possible directions of future investigation are envisaged. One of them is also a possibility of exploiting sPLA2s as biological markers of the severity of the Covid-19 pandemic caused by SARS-CoV-2 infection.
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Affiliation(s)
- Jože Pungerčar
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia.
| | - Franck Bihl
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France
| | - Gérard Lambeau
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France.
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia.
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Dacheux M, Chaouch S, Joy A, Labat A, Payré C, Petit-Paitel A, Bihl F, Lagrange I, Grellier P, Touqui L, Lambeau G, Deregnaucourt C. Role of human group IIA secreted phospholipase A2 in malaria pathophysiology: Insights from a transgenic mouse model. Biochimie 2021; 189:120-136. [PMID: 34175441 DOI: 10.1016/j.biochi.2021.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/17/2021] [Accepted: 06/19/2021] [Indexed: 01/08/2023]
Abstract
We previously showed that injection of recombinant human group IIA secreted phospholipase A2 (hGIIA sPLA2) to Plasmodium chabaudi-infected mice lowers parasitaemia by 20%. Here, we show that transgenic (TG) mice overexpressing hGIIA sPLA2 have a peak of parasitaemia about 30% lower than WT littermates. During infection, levels of circulating sPLA2, enzymatic activity and plasma lipid peroxidation were maximal at day-14, the peak of parasitaemia. Levels of hGIIA mRNA increased in liver but not in spleen and blood cells, suggesting that liver may contribute as a source of circulating hGIIA sPLA2. Before infection, baseline levels of leukocytes and pro-inflammatory cytokines were higher in TG mice than WT littermates. Upon infection, the number of neutrophils, lymphocytes and monocytes increased and were maximal at the peak of parasitaemia in both WT and TG mice, but were higher in TG mice. Similarly, levels of the Th1 cytokines IFN-γ and IL-2 increased in WT and TG mice, but were 7.7- and 1.7-fold higher in TG mice. The characteristic shift towards Th2 cytokines was observed during infection in both WT and TG mice, with increased levels of IL-10 and IL-4 at day-14. The current data are in accordance with our previous in vitro findings showing that hGIIA kills parasites by releasing toxic lipids from oxidized lipoproteins. They further show that hGIIA sPLA2 is induced during mouse experimental malaria and has a protective in vivo role, lowering parasitaemia by likely releasing toxic lipids from oxidized lipoproteins but also indirectly by promoting a more sustained innate immune response.
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Affiliation(s)
- Mélanie Dacheux
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France
| | - Soraya Chaouch
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France
| | - Alonso Joy
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France
| | - Amandine Labat
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France
| | - Christine Payré
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France
| | - Agnès Petit-Paitel
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France
| | - Franck Bihl
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France
| | - Isabelle Lagrange
- Ecole Nationale Vétérinaire d'Alfort, BioPôle, Laboratoire d'hématologie, 94704 Maisons-Alfort, France
| | - Philippe Grellier
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France
| | - Lhousseine Touqui
- Cystic fibrosis and Bronchial diseases team - INSERM U938, Institut Pasteur, 75015 Paris, France; Sorbonne Université, INSERM UMRS938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
| | - Gérard Lambeau
- Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), UMR7275, Valbonne Sophia Antipolis, France.
| | - Christiane Deregnaucourt
- UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Muséum National d'Histoire Naturelle, CNRS, CP52, 61 rue Buffon, Paris Cedex 05 75231, France.
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Roca-Pinilla R, López-Cano A, Saubi C, Garcia-Fruitós E, Arís A. A new generation of recombinant polypeptides combines multiple protein domains for effective antimicrobial activity. Microb Cell Fact 2020; 19:122. [PMID: 32503648 PMCID: PMC7275485 DOI: 10.1186/s12934-020-01380-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 05/27/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Although most of antimicrobial peptides (AMPs), being relatively short, are produced by chemical synthesis, several AMPs have been produced using recombinant technology. However, AMPs could be cytotoxic to the producer cell, and if small they can be easily degraded. The objective of this study was to produce a multidomain antimicrobial protein based on recombinant protein nanoclusters to increase the yield, stability and effectivity. RESULTS A single antimicrobial polypeptide JAMF1 that combines three functional domains based on human α-defensin-5, human XII-A secreted phospholipase A2 (sPLA2), and a gelsolin-based bacterial-binding domain along with two aggregation-seeding domains based on leucine zippers was successfully produced with no toxic effects for the producer cell and mainly in a nanocluster structure. Both, the nanocluster and solubilized format of the protein showed a clear antimicrobial effect against a broad spectrum of Gram-negative and Gram-positive bacteria, including multi-resistant strains, with an optimal concentration between 1 and 10 µM. CONCLUSIONS Our findings demonstrated that multidomain antimicrobial proteins forming nanoclusters can be efficiently produced in recombinant bacteria, being a novel and valuable strategy to create a versatile, highly stable and easily editable multidomain constructs with a broad-spectrum antimicrobial activity in both soluble and nanostructured format.
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Affiliation(s)
- Ramon Roca-Pinilla
- Department of Ruminant Production, Institute of Agriculture and Food Research (IRTA), 08140, Caldes de Montbui, Spain
| | - Adrià López-Cano
- Department of Ruminant Production, Institute of Agriculture and Food Research (IRTA), 08140, Caldes de Montbui, Spain
| | - Cristina Saubi
- Department of Ruminant Production, Institute of Agriculture and Food Research (IRTA), 08140, Caldes de Montbui, Spain
| | - Elena Garcia-Fruitós
- Department of Ruminant Production, Institute of Agriculture and Food Research (IRTA), 08140, Caldes de Montbui, Spain.
| | - Anna Arís
- Department of Ruminant Production, Institute of Agriculture and Food Research (IRTA), 08140, Caldes de Montbui, Spain.
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Murakami M, Miki Y, Sato H, Murase R, Taketomi Y, Yamamoto K. Group IID, IIE, IIF and III secreted phospholipase A 2s. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:803-818. [PMID: 30905347 PMCID: PMC7106514 DOI: 10.1016/j.bbalip.2018.08.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/31/2018] [Accepted: 08/27/2018] [Indexed: 12/02/2022]
Abstract
Among the 11 members of the secreted phospholipase A2 (sPLA2) family, group IID, IIE, IIF and III sPLA2s (sPLA2-IID, -IIE, -IIF and -III, respectively) are “new” isoforms in the history of sPLA2 research. Relative to the better characterized sPLA2s (sPLA2-IB, -IIA, -V and -X), the enzymatic properties, distributions, and functions of these “new” sPLA2s have remained obscure until recently. Our current studies using knockout and transgenic mice for a nearly full set of sPLA2s, in combination with comprehensive lipidomics, have revealed unique and distinct roles of these “new” sPLA2s in specific biological events. Thus, sPLA2-IID is involved in immune suppression, sPLA2-IIE in metabolic regulation and hair follicle homeostasis, sPLA2-IIF in epidermal hyperplasia, and sPLA2-III in male reproduction, anaphylaxis, colonic diseases, and possibly atherosclerosis. In this article, we overview current understanding of the properties and functions of these sPLA2s and their underlying lipid pathways in vivo.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; AMED-CREST, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
| | - Yoshimi Miki
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Hiroyasu Sato
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Remi Murase
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Yoshitaka Taketomi
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Kei Yamamoto
- PRIME, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan; Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima 770-8513, Japan.
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7
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Murakami M, Yamamoto K, Miki Y, Murase R, Sato H, Taketomi Y. The Roles of the Secreted Phospholipase A 2 Gene Family in Immunology. Adv Immunol 2016; 132:91-134. [PMID: 27769509 PMCID: PMC7112020 DOI: 10.1016/bs.ai.2016.05.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Within the phospholipase A2 (PLA2) family that hydrolyzes phospholipids to yield fatty acids and lysophospholipids, secreted PLA2 (sPLA2) enzymes comprise the largest group containing 11 isoforms in mammals. Individual sPLA2s exhibit unique tissue or cellular distributions and enzymatic properties, suggesting their distinct biological roles. Although PLA2 enzymes, particularly cytosolic PLA2 (cPLA2α), have long been implicated in inflammation by driving arachidonic acid metabolism, the precise biological roles of sPLA2s have remained a mystery over the last few decades. Recent studies employing mice gene-manipulated for individual sPLA2s, in combination with mass spectrometric lipidomics to identify their target substrates and products in vivo, have revealed their roles in diverse biological events, including immunity and associated disorders, through lipid mediator-dependent or -independent processes in given microenvironments. In this review, we summarize our current knowledge of the roles of sPLA2s in various immune responses and associated diseases.
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Affiliation(s)
- M Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.
| | - K Yamamoto
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Y Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - R Murase
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - H Sato
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Y Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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8
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Zhang C, Yu H, Xu H, Yang L. Expression of secreted phospholipase A2-Group IIA correlates with prognosis of gastric adenocarcinoma. Oncol Lett 2015; 10:3050-3058. [PMID: 26722288 DOI: 10.3892/ol.2015.3736] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 08/17/2015] [Indexed: 12/14/2022] Open
Abstract
The present study investigated the expression of secretory phospholipase A2-Group IIA (sPLA2-II) in gastric adenocarcinoma, in order to evaluate the correlation between sPLA2-II expression, and the clinicopathological features and prognosis of patients with gastric adenocarcinoma. Between January 2007 and April 2010, data were collected from 65 patients (44 males, 21 females; age range, 30-79 years; mean 66.7 ± 10.7 years). All patients exhibited a pathologically confirmed diagnosis of gastric adenocarcinoma. Endoscopic biopsy specimens of normal gastric mucosa from 11 of these patients were used as controls. Patients were subsequently followed-up at 3-month intervals, and survival data were recorded until April 2010. Expression of sPLA2-II in 65 gastric adenocarcinoma and 11 normal gastric mucosa specimens was evaluated via immunohistochemistry. A semi-quantitative method, consisting of evaluation of staining percentage and intensity, was utilized for immunohistochemical scoring, and the receiver operating characteristic curve method was applied to select a cut-off score for high and low sPLA2-II expression. The value of 8 was selected as the cut-off score, with maximum sensitivity and specificity. High sPLA2-II expression was observed in stage III/IV cases (83.3%; 40/48) and poorly differentiated cells (94.1%; 32/34), while sPLA2-II expression levels were observed to be significantly lower in stage I/II cases (52.9%; 9/17) and well and moderately differentiated cells (54.8%; 17/31; P=0.021 and P<0.001, respectively). There were no significant correlations observed between sPLA2-II expression and any other clinicopathological parameters, including gender, age, tumor diameter and Helicobacter pylori infection. Patients exhibiting low sPLA2-II expression experienced significantly improved overall survival (OS) and disease-free survival (DFS), compared with those exhibiting high sPLA2-II expression (P=0.043 and P=0.035, respectively). Multivariate analysis confirmed that high sPLA2-II expression may be an independent prognostic factor for OS [relative risk, 2.849; 95% confidence interval (CI), 1.088-7.459; P=0.033] and DFS (relative risk, 2.735; 95% CI, 1.104-6.776; P=0.030) in gastric adenocarcinoma. Therefore, sPLA2-II may be correlated with the histogenesis of gastric adenocarcinoma, and increased sPLA2-II expression may be an indicator of poor prognosis.
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Affiliation(s)
- Chengwei Zhang
- Department of Anesthesiology, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
| | - Haipeng Yu
- Department of Interventional Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, P.R. China
| | - Haiyan Xu
- Department of Physiology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Lanlan Yang
- Department of Biliary and Pancreatic Internal Medicine, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
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9
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Murakami M, Sato H, Miki Y, Yamamoto K, Taketomi Y. A new era of secreted phospholipase A₂. J Lipid Res 2015; 56:1248-61. [PMID: 25805806 DOI: 10.1194/jlr.r058123] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Indexed: 12/18/2022] Open
Abstract
Among more than 30 members of the phospholipase A2 (PLA2) superfamily, secreted PLA2 (sPLA2) enzymes represent the largest family, being Ca(2+)-dependent low-molecular-weight enzymes with a His-Asp catalytic dyad. Individual sPLA2s exhibit unique tissue and cellular distributions and enzymatic properties, suggesting their distinct biological roles. Recent studies using transgenic and knockout mice for nearly a full set of sPLA2 subtypes, in combination with sophisticated lipidomics as well as biochemical and cell biological studies, have revealed distinct contributions of individual sPLA2s to various pathophysiological events, including production of pro- and anti-inflammatory lipid mediators, regulation of membrane remodeling, degradation of foreign phospholipids in microbes or food, or modification of extracellular noncellular lipid components. In this review, we highlight the current understanding of the in vivo functions of sPLA2s and the underlying lipid pathways as revealed by a series of studies over the last decade.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Hiroyasu Sato
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Kei Yamamoto
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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10
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Peuravuori H, Kollanus S, Nevalainen TJ. Expression of group XIIA phospholipase A2in human digestive organs. APMIS 2014; 122:1171-7. [DOI: 10.1111/apm.12280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 03/10/2014] [Indexed: 11/29/2022]
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11
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Ee SM, Lo YL, Shui G, Wenk MR, Shin EJ, Kim HC, Ong WY. Distribution of secretory phospholipase A2 XIIA in the brain and its role in lipid metabolism and cognition. Mol Neurobiol 2014; 50:60-75. [PMID: 24464264 DOI: 10.1007/s12035-014-8635-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/02/2014] [Indexed: 01/03/2023]
Abstract
Phospholipases A(2) (PLA(2)) catalyze the hydrolysis of membrane phospholipids to produce free fatty acids and lysophospholipids, which have important functions in cell signaling. The present study elucidated differential expression of PLA(2) isoforms in the rat cortex by quantitative reverse transcription PCR and demonstrated that sPLA(2)-XIIA had greater messenger RNA expression than iPLA(2)-VI or cPLA(2)-IVA in different brain regions, or compared to other sPLA(2) isoforms in the prefrontal cortex (PFC) and hippocampus. Western blots identified a 24-kDa band in different regions of the adult brain, and high levels of sPLA(2)-XIIA protein expression were detected in the PFC, striatum, and thalamus. Electron microscopy showed that sPLA(2)-XIIA is present in axon terminals and dendrites. Injection of antisense oligonucleotide to sPLA(2)-XIIA in the PFC and lipidomic analysis showed increase in phospholipid but decrease in lysophospholipid species consistent with decreased catalytic activity of the enzyme, changes in arachidonic acid release, and alterations in sphingolipids. sPLA(2)-XIIA knockdown also resulted in shorter latency timings in the passive avoidance test, and higher number of errors in the attention set-shifting task, indicating deficits in working memory and attention. Together, the results show an important role of sPLA(2)-XIIA in lipid metabolism, prefrontal cortical function, and cognition.
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Affiliation(s)
- Sze-Min Ee
- Department of Anatomy, National University of Singapore, Singapore, 119260, Singapore
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Romero R, Yoon BH, Chaemsaithong P, Cortez J, Park CW, Gonzalez R, Behnke E, Hassan SS, Gotsch F, Yeo L, Chaiworapongsa T. Secreted phospholipase A2 is increased in meconium-stained amniotic fluid of term gestations: potential implications for the genesis of meconium aspiration syndrome. J Matern Fetal Neonatal Med 2014; 27:975-83. [PMID: 24063538 DOI: 10.3109/14767058.2013.847918] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Meconium-stained amniotic fluid (MSAF) represents the passage of fetal colonic content into the amniotic cavity. Meconium aspiration syndrome (MAS) is a complication that occurs in a subset of infants with MSAF. Secreted phospholipase A2 (sPLA2) is detected in meconium and is implicated in the development of MAS. The purpose of this study was to determine if sPLA2 concentrations are increased in the amniotic fluid of women in spontaneous labor at term with MSAF. MATERIALS AND METHODS This was a cross-sectional study of patients in spontaneous term labor who underwent amniocentesis (n = 101). The patients were divided into two study groups: (1) MSAF (n = 61) and (2) clear fluid (n = 40). The presence of bacteria and endotoxin as well as interleukin-6 (IL-6) and sPLA2 concentrations in the amniotic fluid were determined. Statistical analyses were performed to test for normality and bivariate analysis. The Spearman correlation coefficient was used to study the relationship between sPLA2 and IL-6 concentrations in the amniotic fluid. RESULTS Patients with MSAF have a higher median sPLA2 concentration (ng/mL) in amniotic fluid than those with clear fluid [1.7 (0.98-2.89) versus 0.3 (0-0.6), p < 0.001]. Among patients with MSAF, those with either microbial invasion of the amniotic cavity (MIAC, defined as presence of bacteria in the amniotic cavity), or bacterial endotoxin had a significantly higher median sPLA2 concentration (ng/mL) in amniotic fluid than those without MIAC or endotoxin [2.4 (1.7-6.0) versus 1.7 (1.3-2.5), p < 0.05]. There was a positive correlation between sPLA2 and IL-6 concentrations in the amniotic fluid (Spearman Rho = 0.3, p < 0.05). CONCLUSION MSAF that contains bacteria or endotoxin has a higher concentration of sPLA2, and this may contribute to induce lung inflammation when meconium is aspirated before birth.
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Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS , Bethesda, MD and Detroit, MI , USA
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Nevalainen TJ, Cardoso JCR. Conservation of group XII phospholipase A2 from bacteria to human. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2012; 7:340-50. [PMID: 22909802 DOI: 10.1016/j.cbd.2012.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/18/2012] [Accepted: 07/18/2012] [Indexed: 12/26/2022]
Abstract
Vertebrate group XII phospholipases A(2) (GXII PLA(2), conserved domain pfam06951) are proteins with unique structural and functional features within the secreted PLA(2) family. In humans, two genes (GXIIA PLA(2) and GXIIB PLA(2)) have been characterised. GXIIA PLA(2) is enzymatically active whereas GXIIB PLA(2) is devoid of catalytic activity. Recently, putative homologues of the vertebrate GXII PLA(2)s were described in non-vertebrates. In the current study a total of 170 GXII PLA(2) sequences were identified in vertebrates, invertebrates, non-metazoan eukaryotes, fungi and bacteria. GXIIB PLA(2) was found only in vertebrates and the searches failed to identify putative GXII PLA(2) homologues in Archaea. Comparisons of the predicted functional domains of GXII PLA(2)s revealed considerable structural identity within the Ca(2+)-binding and the catalytic sites among the various organisms suggesting that functional conservation may have been retained across evolution. The preservation of GXII PLA(2) family members from bacteria to human indicates that they have emerged early in evolution and evolved via gene/genome duplication events prior to Eubacteria. Gene duplicates were identified in some invertebrate taxa suggesting that species-specific duplications occurred. The analysis of the GXII PLA(2) homologue genome environment revealed that gene synteny and gene order are preserved in vertebrates. Conservation of GXII PLA(2)s indicates that important functional roles involved in species survival and were maintained across evolution and may be dependent on or independent of the enzyme's phospholipolytic activity.
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Abstract
Phospholipids are present in all living organisms. They are a major component of all biological membranes, along with glycolipids and cholesterol. Enzymes aimed at cleaving the various bonds in phospholipids, namely phospholipases, are consequently widespread in nature, playing very diverse roles from aggression in snake venom to signal transduction, lipid mediators production, and digestion in humans. Although all phospholipases target phospholipids as substrates, they vary in the site of action on the phospholipids molecules, physiological function, mode of action, and their regulation. Significant studies on phospholipases characterization, physiological role, and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances, such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factors and major causes of pathophysiological effects. In this introductory chapter, we provide brief details of different phospholipases.
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Affiliation(s)
- Ahmed Aloulou
- National School of Engineers of Sfax, University of Sfax, Sfax, Tunisia.
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15
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Characterization of serum phospholipase a(2) activity in three diverse species of west african crocodiles. Biochem Res Int 2011; 2011:925012. [PMID: 22110960 PMCID: PMC3205705 DOI: 10.1155/2011/925012] [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: 03/27/2011] [Revised: 07/21/2011] [Accepted: 07/25/2011] [Indexed: 11/17/2022] Open
Abstract
Secretory phospholipase A(2), an enzyme that exhibits substantial immunological activity, was measured in the serum of three species of diverse West African crocodiles. Incubation of different volumes of crocodile serum with bacteria labeled with a fluorescent fatty acid in the sn-2 position of membrane lipids resulted in a volume-dependent liberation of fluorescent probe. Serum from the Nile crocodile (Crocodylus niloticus) exhibited slightly higher activity than that of the slender-snouted crocodile (Mecistops cataphractus) and the African dwarf crocodile (Osteolaemus tetraspis). Product formation was inhibited by BPB, a specific PLA(2) inhibitor, confirming that the activity was a direct result of the presence of serum PLA(2). Kinetic analysis showed that C. niloticus serum produced product more rapidly than M. cataphractus or O. tetraspis. Serum from all three species exhibited temperature-dependent PLA(2) activities but with slightly different thermal profiles. All three crocodilian species showed high levels of activity against eight different species of bacteria.
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Murakami M, Taketomi Y, Sato H, Yamamoto K. Secreted phospholipase A2 revisited. J Biochem 2011; 150:233-55. [PMID: 21746768 DOI: 10.1093/jb/mvr088] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Phospholipase A(2) (PLA(2)) catalyses the hydrolysis of the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. So far, more than 30 enzymes that possess PLA(2) or related activity have been identified in mammals. About one third of these enzymes belong to the secreted PLA(2) (sPLA(2)) family, which comprises low molecular weight, Ca(2+) requiring, secreted enzymes with a His/Asp catalytic dyad. Individual sPLA(2)s display distinct localizations and enzymatic properties, suggesting their specialized biological roles. However, in contrast to intracellular PLA(2)s, whose roles in signal transduction and membrane homoeostasis have been well documented, the biological roles of sPLA(2)s in vivo have remained obscure until recently. Over the past decade, information fuelled by studies employing knockout and transgenic mice as well as specific inhibitors, in combination with lipidomics, has clarified when and where the different sPLA(2) isoforms are expressed, which isoforms are involved in what types of pathophysiology, and how they exhibit their specific functions. In this review, we highlight recent advances in PLA(2) research, focusing mainly on the physiological functions of sPLA(2)s and their modes of action on 'extracellular' phospholipid targets versus lipid mediator production.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Abu-Maziad A, Schaa K, Bell EF, Dagle JM, Cooper M, Marazita ML, Murray JC. Role of polymorphic variants as genetic modulators of infection in neonatal sepsis. Pediatr Res 2010; 68:323-9. [PMID: 20463618 PMCID: PMC2940937 DOI: 10.1203/pdr.0b013e3181e6a068] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study is a retrospective, case control study involving 535 preterm infants examining the roles of sequence polymorphisms in genes that mediate host immune responses to bacterial infection in newborn infants. A total of 49 single nucleotide polymorphisms (SNPs) in 19 candidate genes including inflammatory cytokines (IL6, IL10, IL1B, and TNF), cytokine receptors (IL1RN), toll-like receptors (TLR2, TLR4, and TLR5), and cell surface receptors (CD14) were genotyped. Subjects were stratified into three groups (sepsis, suspected sepsis, and control). The data were analyzed using a family-based transmission disequilibrium test. We found that birth weight, gestational age, duration of rupture of membranes, and presence of clinical chorioamnionitis were strongly associated with sepsis. Polymorphisms in TLR2 (rs3804099), TLR5 (rs5744105), IL10 (rs1800896), and PLA2G2A (rs1891320) genes were associated with sepsis. Allelic variants in PLA2G2A and TLR2 were associated with Gram-positive infections, whereas IL10 was associated with Gram-negative infections (p < 0.05). We conclude allelic variations in PLA2G2A, TLR2, TLR5, and IL10 may moderate the predisposition to sepsis in preterm infants.
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Affiliation(s)
- Asmaa Abu-Maziad
- Department of Pediatrics, University of Iowa, Children's Hospital, Iowa City, Iowa 52242, USA
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Domingo-Gil E, González JM, Esteban M. Identification of cellular genes induced in human cells after activation of the OAS/RNaseL pathway by vaccinia virus recombinants expressing these antiviral enzymes. J Interferon Cytokine Res 2010; 30:171-88. [PMID: 20038200 DOI: 10.1089/jir.2009.0037] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interferon (IFN) type I induces the expression of antiviral proteins such as 2',5'-oligoadenylate synthetases (OAS). The enzyme OAS is activated by dsRNA to produce 5'-phosphorylated, 2-5-linked oligoadenylates (2-5A) that activate RNaseL which, in turn, triggers RNA breakdown, leading to multiple biological functions. Although RNaseL is required for IFN antiviral function, there are many aspects of the molecular mechanisms that remain obscure. Here, we have used microarray analyses from human HeLa cells infected with vaccinia virus (VACV) recombinants expressing OAS-RNaseL enzymes (referred as 2-5A system) with the aim to identify host genes that are up- or down-regulated in the course of infection by the activation of this antiviral pathway. We found that activation of the 2-5A system from VACV recombinants produces a remarkable stimulation of transcription for genes that regulate many cellular processes, like those that promote cell growth arrest, GADD45B and KCTD11, apoptosis as CUL2, PDCD6, and TNFAIP8L2, IFN-stimulated genes as IFI6, and related to tumor suppression as PLA2G2A. The 2-5A system activation produces down-regulation of transcription of some genes that promote cell growth as RUNX2 and ESR2 and of genes in charge to maintain mitochondria homeostasis as MIPEP and COX5A. These results reveal new genes induced in response to the activation of the 2-5A system with roles in apoptosis, translational control, cell growth arrest, and tumor suppression.
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Affiliation(s)
- Elena Domingo-Gil
- Department of Cellular and Molecular Biology, Centro Nacional de Biotecnología, CSIC, Ciudad Universitaria Cantoblanco, Madrid, Spain
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20
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Murakami M, Taketomi Y, Girard C, Yamamoto K, Lambeau G. Emerging roles of secreted phospholipase A2 enzymes: Lessons from transgenic and knockout mice. Biochimie 2010; 92:561-82. [PMID: 20347923 DOI: 10.1016/j.biochi.2010.03.015] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 03/18/2010] [Indexed: 11/15/2022]
Abstract
Among the emerging phospholipase A(2) (PLA(2)) superfamily, the secreted PLA(2) (sPLA(2)) family consists of low-molecular-mass, Ca(2+)-requiring extracellular enzymes with a His-Asp catalytic dyad. To date, more than 10 sPLA(2) enzymes have been identified in mammals. Individual sPLA(2)s exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Despite numerous enzymatic and cell biological studies on this enzyme family in the past two decades, their precise in vivo functions still remain largely obscure. Recent studies using transgenic and knockout mice for several sPLA(2) enzymes, in combination with lipidomics approaches, have opened new insights into their distinct contributions to various biological events such as food digestion, host defense, inflammation, asthma and atherosclerosis. In this article, we overview the latest understanding of the pathophysiological functions of individual sPLA(2) isoforms fueled by studies employing transgenic and knockout mice for several sPLA(2)s.
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Affiliation(s)
- Makoto Murakami
- Biomembrane Signaling Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Olson ED, Nelson J, Griffith K, Nguyen T, Streeter M, Wilson-Ashworth HA, Gelb MH, Judd AM, Bell JD. Kinetic evaluation of cell membrane hydrolysis during apoptosis by human isoforms of secretory phospholipase A2. J Biol Chem 2010; 285:10993-1002. [PMID: 20139082 DOI: 10.1074/jbc.m109.070797] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Some isoforms of secretory phospholipase A(2) (sPLA(2)) distinguish between healthy and damaged or apoptotic cells. This distinction reflects differences in membrane physical properties. Because various sPLA(2) isoforms respond differently to properties of artificial membranes such as surface charge, they should also behave differently as these properties evolve during a dynamic physiological process such as apoptosis. To test this idea, S49 lymphoma cell death was induced by glucocorticoid (6-48 h) or calcium ionophore. Rates of membrane hydrolysis catalyzed by various concentrations of snake venom and human groups IIa, V, and X sPLA(2) were compared after each treatment condition. The data were analyzed using a model that evaluates the adsorption of enzyme to the membrane surface and subsequent binding of substrate to the active site. Results were compared temporally to changes in membrane biophysics and composition. Under control conditions, membrane hydrolysis was confined to the few unhealthy cells present in each sample. Increased hydrolysis during apoptosis and necrosis appeared to reflect substrate access to adsorbed enzyme for the snake venom and group X isoforms corresponding to weakened lipid-lipid interactions in the membrane. In contrast, apoptosis promoted initial adsorption of human groups V and IIa concurrent with phosphatidylserine exposure on the membrane surface. However, this observation was inadequate to explain the behavior of the groups V and IIa enzymes toward necrotic cells where hydrolysis was reduced or absent. Thus, a combination of changes in cell membrane properties during apoptosis and necrosis capacitates the cell for hydrolysis differently by each isoform.
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Affiliation(s)
- Erin D Olson
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah 84602, USA
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22
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Lambeau G, Gelb MH. Biochemistry and physiology of mammalian secreted phospholipases A2. Annu Rev Biochem 2008; 77:495-520. [PMID: 18405237 DOI: 10.1146/annurev.biochem.76.062405.154007] [Citation(s) in RCA: 406] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phospholipases A(2) (PLA2s) are esterases that hydrolyze the sn-2 ester of glycerophospholipids and constitute one of the largest families of lipid hydrolyzing enzymes. The mammalian genome contains 10 enzymatically active secreted PLA2s (sPLA2s) and two sPLA2-related proteins devoid of lipolytic enzymatic activity. In addition to the well-established functions of one of these enzymes in digestion of dietary phospholipids and another in host defense against bacterial infections, accumulating evidence shows that some of these sPLA2s are involved in arachidonic acid release from cellular phospholipids for the biosynthesis of eicosanoids, especially during inflammation. More speculative results suggest the involvement of one or more sPLA2s in promoting atherosclerosis and cancer. In addition, the mammalian genome encodes several types of sPLA2-binding proteins, and mounting evidence shows that sPLA2s may have functions related to binding to cellular target proteins in a manner independent of their lipolytic enzymatic activity.
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Affiliation(s)
- Gérard Lambeau
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Université de Nice-Sophia-Antipolis, 06560 Valbonne, France.
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23
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Variation near complement factor I is associated with risk of advanced AMD. Eur J Hum Genet 2008; 17:100-4. [PMID: 18685559 DOI: 10.1038/ejhg.2008.140] [Citation(s) in RCA: 263] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A case-control association study for advanced age-related macular degeneration was conducted to explore several regions of interest identified by linkage. This analysis identified a single nucleotide polymorphism just 3' of complement factor I on chromosome 4 showing significant association (P<10(-7)). Sequencing was performed on coding exons in linkage disequilibrium with the detected association. No obvious functional variation was discovered that could be the proximate cause of the association, suggesting a noncoding regulatory mechanism.
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Peters GH, Møller MS, Jørgensen K, Rönnholm P, Mikkelsen M, Andresen TL. Secretory phospholipase A2 hydrolysis of phospholipid analogues is dependent on water accessibility to the active site. J Am Chem Soc 2007; 129:5451-61. [PMID: 17419625 DOI: 10.1021/ja067755b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A new and unnatural type of phospholipids with the head group attached to the 2-position of the glycerol backbone has been synthesized and shown to be a good substrate for secretory phospholipase A2 (sPLA2). To investigate the unexpected sPLA2 activity, we have compared three different phospholipids by using fluorescence techniques and HPLC, namely: (R)-1,2-dipalmitoyl-glycero-3-phosphocholine (hereafter referred to as 1R), (R)-1-O-hexadecyl-2-palmitoyl-glycero-3-phoshocholine (2R), and (S)-1-O-hexadecyl-3-palmitoyl-glycero-2-phosphocholine (3S). Furthermore, to understand the underlying mechanisms for the observed differences, we have performed molecular dynamics simulations to clarify on a structural level the substrate specificity of sPLA2 toward phospholipid analogues with their head groups in the 2-position of the glycerol backbone. We have studied the lipids above 1R, 2R, and 3S as well as their enantiomers 1S, 2S, and 3R. In the simulations of sPLA2-1S and sPLA2-3R, structural distortion in the binding cleft induced by the phospholipids showed that these are not substrates for sPLA2. In the case of the phospholipids 1R, 2R, and 3S, our simulations revealed that the difference observed experimentally in sPLA2 activity might be caused by reduced access of water molecules to the active site. We have monitored the number of water molecules that enter the active site region for the different sPLA2-phospholipid complexes and found that the probability of a water molecule reaching the correct position such that hydrolysis can occur is reduced for the unnatural lipids. The relative water count follows 1R > 2R > 3S. This is in good agreement with experimental data that indicate the same trend for sPLA2 activity: 1R > 2R > 3S.
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Affiliation(s)
- Günther H Peters
- Department of Chemistry, MEMPHYS-Center for Biomembrane Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
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Lee VT, Pukatzki S, Sato H, Kikawada E, Kazimirova AA, Huang J, Li X, Arm JP, Frank DW, Lory S. Pseudolipasin A is a specific inhibitor for phospholipase A2 activity of Pseudomonas aeruginosa cytotoxin ExoU. Infect Immun 2006; 75:1089-98. [PMID: 17178785 PMCID: PMC1828555 DOI: 10.1128/iai.01184-06] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A number of bacterial pathogens utilize the type III secretion pathway to deliver effector proteins directly into the host cell cytoplasm. Certain strains of Pseudomonas aeruginosa associated with acute infections express a potent cytotoxin, exoenzyme U (ExoU), that is delivered via the type III secretion pathway directly into contacting host cells. Once inside the mammalian cell, ExoU rapidly lyses the intoxicated cells via its phospholipase A(2) (PLA(2)) activity. A high-throughput cell-based assay was developed to screen libraries of compounds for those capable of protecting cells against the cytotoxic effects of ExoU. A number of compounds were identified in this screen, including one group that blocks the intracellular activity of ExoU. In addition, these compounds specifically inhibited the PLA(2) activity of ExoU in vitro, whereas eukaryotic secreted PLA(2) and cytosolic PLA(2) were not inhibited. This novel inhibitor of ExoU-specific PLA(2) activity, named pseudolipasin A, may provide a new lead for virulence factor-based therapeutic design.
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Affiliation(s)
- Vincent T Lee
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
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