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Gao N, Wang J, Fang C, Bai P, Sun Y, Wu W, Shan A. Combating bacterial infections with host defense peptides: Shifting focus from bacteria to host immunity. Drug Resist Updat 2024; 72:101030. [PMID: 38043443 DOI: 10.1016/j.drup.2023.101030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/12/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
The increasing prevalence of multidrug-resistant bacterial infections necessitates the exploration of novel paradigms for anti-infective therapy. Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), have garnered extensive recognition as immunomodulatory molecules that leverage natural host mechanisms to enhance therapeutic benefits. The unique immune mechanism exhibited by certain HDPs that involves self-assembly into supramolecular nanonets capable of inducing bacterial agglutination and entrapping is significantly important. This process effectively prevents microbial invasion and subsequent dissemination and significantly mitigates selective pressure for the evolution of microbial resistance, highlighting the potential of HDP-based antimicrobial therapy. Recent advancements in this field have focused on developing bio-responsive materials in the form of supramolecular nanonets. A comprehensive overview of the immunomodulatory and bacteria-agglutinating activities of HDPs, along with a discussion on optimization strategies for synthetic derivatives, is presented in this article. These optimized derivatives exhibit improved biological properties and therapeutic potential, making them suitable for future clinical applications as effective anti-infective therapeutics.
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Affiliation(s)
- Nan Gao
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China
| | - Jiajun Wang
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China.
| | - Chunyang Fang
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China
| | - Pengfei Bai
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China
| | - Yu Sun
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China
| | - Wanpeng Wu
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China
| | - Anshan Shan
- Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China.
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Yang Y, Zhao J, Jiang C, Zhang Y, Han M, Liu H. WKYMVm Works by Targeting Immune Cells. J Inflamm Res 2023; 16:45-55. [PMID: 36636250 PMCID: PMC9831254 DOI: 10.2147/jir.s390394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/24/2022] [Indexed: 01/07/2023] Open
Abstract
WKYMVm (Trp-Lys-Tyr-Met-Val-D-Met) is a synthetic hexapeptide identified as a potent agonist of FPRs. FPRs are widely expressed on the cell membrane of immune cells. Therefore, WKYMVm participates in the regulation of immune cells by activating FPRs, and plays a therapeutic role in infections, tumors, autoimmune diseases and so on. WKYMVm can promote the chemotactic migration, increase the bactericidal activity of neutrophils and monocytes. WKYMVm also regulates the number and polarization of macrophages, affects the maturation of DCs and the differentiation of T cells, and promotes the activation and chemotaxis of NK cells. These functions make WKYMVm a candidate drug for immunotherapy. In this paper, we summarize the regulatory effects and underlying mechanisms of WKYMVm on six immune cells (neutrophils, monocytes, macrophages, DCs, T cells and NK cells) to increase comprehensive understanding and promote further research on WKYMVm.
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Affiliation(s)
- Yuting Yang
- Department of Gastroenterology, Second Hospital of Dalian Medical University, Dalian, Liaoning, 116000, People’s Republic of China
| | - Jin Zhao
- Department of Pulmonary and Critical Care Medicine, Air Force Medical Center, PLA, Beijing, 100000, People’s Republic of China
| | - Chunmeng Jiang
- Department of Gastroenterology, Second Hospital of Dalian Medical University, Dalian, Liaoning, 116000, People’s Republic of China
| | - Yue Zhang
- Department of Gastroenterology, Second Hospital of Dalian Medical University, Dalian, Liaoning, 116000, People’s Republic of China
| | - Mei Han
- Department of Gastroenterology, Second Hospital of Dalian Medical University, Dalian, Liaoning, 116000, People’s Republic of China
| | - Hui Liu
- Department of Gastroenterology, Second Hospital of Dalian Medical University, Dalian, Liaoning, 116000, People’s Republic of China,Correspondence: Hui Liu; Mei Han, Department of Gastroenterology, Second Hospital of Dalian Medical University, 467 Zhongshan Road, Shahekou Region, Dalian, Liaoning, 116000, People’s Republic of China, Email ;
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Characterization of the binding of cytosolic phospholipase A 2 alpha and NOX2 NADPH oxidase in mouse macrophages. Mol Biol Rep 2022; 49:3511-3518. [PMID: 35092565 DOI: 10.1007/s11033-022-07191-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/25/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND Previous studies have demonstrated that cytosolic phospholipase A2α (cPLA2α) is required for NOX2 NADPH oxidase activation in human and mouse phagocytes. Moreover, upon stimulation, cPLA2α translocates to the plasma membranes by binding to the assembled oxidase, forming a complex between its C2 domain and the PX domain of the cytosolic oxidase factor, p47phox in human phagocytes. Intravenous administration of antisense against cPLA2α that significantly inhibited its expression in mouse peritoneal neutrophils and macrophages also inhibited superoxide production, in contrast to cPLA2α knockout mice that showed normal superoxide production. The present study aimed to determine whether there is a binding between cPLA2α-C2 domain and p47phox-PX in mouse macrophages, to further support the role of cPLA2α in oxidase regulation also in mouse phagocytes. METHODS AND RESULTS A significant binding of mouse GST-p47phox-PX domain fusion protein and cPLA2α in stimulated mouse phagocyte membranes was demonstrated by pull-down experiments, although lower than that detected by the human p47phox-PX domain. Substituting the amino acids Phe98, Asn99, and Gly100 to Cys98, Ser99, and Thr100 in the mouse p47phox-PX domain (present in the human p47phox-PX domain) caused strong binding that was similar to that detected by the human p47phox-PX domain CONCLUSIONS: The binding between cPLA2α-C2 and p47phox-PX domains exists in mouse macrophages and is not unique to human phagocytes. The binding between the two proteins is lower in the mice, probably due to the absence of amino acids Cys98, Ser 99, and Thr100in the p47phox-PX domain that facilitate the binding to cPLA2α.
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Nauseef WM, Clark RA. Intersecting Stories of the Phagocyte NADPH Oxidase and Chronic Granulomatous Disease. Methods Mol Biol 2019; 1982:3-16. [PMID: 31172463 DOI: 10.1007/978-1-4939-9424-3_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Neutrophils serve as the circulating cells that respond early and figure prominently in human host defense to infection and in inflammation in other settings. Optimal oxidant-dependent antimicrobial activity by neutrophils relies on the ability of stimulated phagocytes to utilize a multicomponent NADPH oxidase to generate oxidants. The frequent, severe, and often fatal infections experienced by individuals with chronic granulomatous disease (CGD), an inherited disorder in which one of the NADPH oxidase components is absent or dysfunctional, underscore the link between a functional phagocyte NADPH oxidase and robust host protection against microbial infection.The history of the discovery and characterization of the normal neutrophil NADPH oxidase and the saga of recognizing CGD and its underlying causes together illustrate how the observations of astute clinicians and imaginative basic scientists synergize to forge new understanding of both basic cell biology and pathogenesis of human disease.In this chapter, we review the events in the stepwise evolution of our understanding of the phagocyte NADPH oxidase, both in the context of normal human neutrophil function and in the setting of CGD. The phagocyte oxidase complex employs a heterodimeric transmembrane protein composed of gp91phox and p22phox to relay electrons from NADPH to molecular oxygen, while other cofactors contribute to localization and regulation of the activity of the assembled oxidase. The b-type cytochrome gp91phox, also known as NOX2, serves as the catalytic component of this multicomponent enzyme complex. Although many of the features of the composition and regulation of the phagocyte oxidase may apply as well to NOX2 expressed in non-phagocytes and to other members of the NOX protein family, exceptions exist and pose special challenges to investigators exploring the biology of NADPH oxidases.
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Affiliation(s)
- William M Nauseef
- Inflammation Program, Department of Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Robert A Clark
- Institute for Integration of Medicine and Science and Department of Medicine, University of Texas Health Science Center, and South Texas Veterans Healthcare System, San Antonio, TX, USA.
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5
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Kim HS, Park MY, Lee SK, Park JS, Lee HY, Bae YS. Activation of formyl peptide receptor 2 by WKYMVm enhances emergency granulopoiesis through phospholipase C activity. BMB Rep 2018. [PMID: 30021674 PMCID: PMC6130828 DOI: 10.5483/bmbrep.2018.51.8.080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Emergency granulopoiesis is a very important strategy to supply efficient neutrophil number in response to infection. However, molecular mechanism involved in this process remains unclear. Here, we found that administration of WKYMVm, an immune modulating peptide, to septic mice strongly increased neutrophil number through augmented emergency granulopoiesis. WKYMVm-induced emergency granulopoiesis was blocked not only by a formyl peptide receptor 2 (FPR2) antagonist (WRW4), but also by FPR2 deficiency. As progenitors of neutrophils, Lin−c-kit+Sca-1− cells expressed FPR2. WKYMVm-induced emergency granulopoiesis was also blocked by a phospholipase C inhibitor (U-73122). These results suggest that WKYMVm can stimulate emergency granulopoiesis via FPR2 and phospholipase C enzymatic activity.
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Affiliation(s)
- Hyung Sik Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
| | - Min Young Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
| | - Sung Kyun Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
- Present address: Institute for Stem Cell & Regenerative Medicine Research of Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Joon Seong Park
- Department of Hematology-Oncology, Ajou University School of Medicine, Suwon 16499, Korea
| | - Ha Young Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
| | - Yoe-Sik Bae
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
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6
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Boros D, Thompson J, Larson DF. Adenosine regulation of the immune response initiated by ischemia reperfusion injury. Perfusion 2015; 31:103-10. [PMID: 25987550 DOI: 10.1177/0267659115586579] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
It is clinically established that adenosine has negative chronotropic, antiarrhythmic effects and reduces arterial blood pressure. Adenosine addition to cardioplegic solutions used in cardiac operations is clinically well tolerated and has been shown to improve myocardial protection in several studies. However, the mechanism of action remains unclear. Therefore, it is important to define the effect of adenosine on the inflammatory cascade as immune cell activation occurs early during ischemia reperfusion injury. Adenosine appears to mediate the initial steps of the inflammatory cascade via its four G-coupled protein receptors: A1, A2A, A2B, and A3, expressed on neutrophils, lymphocytes and macrophages. The adenosine receptor isotype dictates the immune response. More specifically, the A1 and A3 receptors stimulate a pro-inflammatory immune response whereas the A2A and A2B are immunosuppressive. As the adenosine receptors are important for cardiac pre-conditioning and post-conditioning, adenosine may regulate the inflammatory responses initiated during ischemia-mediated immune injury related to myocardial protection.
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Affiliation(s)
- D Boros
- Sarver Heart Center, College of Medicine, The University of Arizona, Tucson, AZ, USA
| | - J Thompson
- Sarver Heart Center, College of Medicine, The University of Arizona, Tucson, AZ, USA
| | - D F Larson
- Sarver Heart Center, College of Medicine, The University of Arizona, Tucson, AZ, USA
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A novel delivery platform for therapeutic peptides. Biochem Biophys Res Commun 2014; 450:13-8. [DOI: 10.1016/j.bbrc.2014.05.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 05/13/2014] [Indexed: 12/20/2022]
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Kim SD, Lee HY, Shim JW, Kim HJ, Baek SH, Zabel BA, Bae YS. A WKYMVm-containing combination elicits potent anti-tumor activity in heterotopic cancer animal model. PLoS One 2012; 7:e30522. [PMID: 22295090 PMCID: PMC3266298 DOI: 10.1371/journal.pone.0030522] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 12/18/2011] [Indexed: 01/09/2023] Open
Abstract
The development of efficient anti-cancer therapy has been a topic of intense interest for several decades. Combined administration of certain molecules and immune cells has been shown to be an effective form of anti-cancer therapy. Here, we examined the effects of administering an immune stimulating peptide (WKYMVm), 5-fluoro-uracil (5-FU), and mature dendritic cells (mDCs) against heterotopic cancer animal model. Administration of the triple combination strongly reduced tumor volume in CT-26-inoculated heterotopic cancer animal model. The induced anti-tumor activity was well correlated with FAS expression, caspase-3 activation, and cancer cell apoptosis. The triple combination treatment caused recruitment of CD8 T lymphocytes and natural killer (NK) cells into the tumor. The production of two cytokines, IFN-γ and IL-12, were strongly stimulated by administration of the triple combination. Depletion of CD8 T lymphocytes or NK cells by administration of anti-CD8 or anti-asialoGM1 antibody inhibited the anti-tumor activity and cytokine production of the triple combination. The triple combination strongly inhibited metastasis of colon cancer cells in a heterotopic cancer animal model as well as in a metastatic cancer animal model, and enhanced the survival rate of the mice model. Adoptive transfer of CD8 T lymphocytes and NK cells further increased the survival rate. Taken together, we suggest that the use of triple combination therapy of WKYMVm, 5-FU, and mDCs may have implications in solid tumor and metastasis treatment.
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Affiliation(s)
- Sang Doo Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
- Mitochondria Hub Regulation Center, Dong-A University, Busan, South Korea
| | - Ha Young Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
- Mitochondria Hub Regulation Center, Dong-A University, Busan, South Korea
| | - Jae Woong Shim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Hak Jung Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
- Mitochondria Hub Regulation Center, Dong-A University, Busan, South Korea
| | - Suk-Hwan Baek
- Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu, Korea
| | - Brian A. Zabel
- Palo Alto Institute for Research and Education, Veterans Affairs Hospital, Palo Alto, California, United States of America
| | - Yoe-Sik Bae
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
- Mitochondria Hub Regulation Center, Dong-A University, Busan, South Korea
- * E-mail:
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9
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Pergola C, Rogge A, Dodt G, Northoff H, Weinigel C, Barz D, Rådmark O, Sautebin L, Werz O. Testosterone suppresses phospholipase D, causing sex differences in leukotriene biosynthesis in human monocytes. FASEB J 2011; 25:3377-87. [PMID: 21693622 DOI: 10.1096/fj.11-182758] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sex disparities in inflammation have been reported, but the cellular and molecular basis for these discrepancies is unknown. Monocytes are central effector cells in immunity and possess high capacities to produce proinflammatory leukotrienes (LTs). Here, we investigated sex differences in the activation of 5-lipoxygenase (5-LO), the key enzyme in LT biosynthesis, in human peripheral monocytes. In cells from females, 5-LO product formation was 1.8-fold higher than in cells from males, as evaluated by HPLC. When female monocytes were resuspended in plasma from males, 5-LO products were significantly lower than in female plasma. Interestingly, 5α-dihydrotestosterone (5α-DHT, 10 nM) repressed LT synthesis in female cells down to the levels observed in males, while estradiol (100 nM) was without effect, and progesterone (100 nM) caused only a slight inhibition. 5α-DHT (10 nM) caused ERK phosphorylation and inhibition of phospholipase D (PLD), as evaluated by Western blot and measurement of PLD activity via radioenzymatic diacylglyceride (DAG) and nonradioactive choline assays. Accordingly, PLD activity and DAG formation were 1.4- to 1.8-fold lower in male vs. female monocytes connected to increased ERK phosphorylation. Our data indicate that ERK activation by androgens in monocytes represses PLD activity, resulting in impaired 5-LO product formation due to lack of activating DAGs.
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Affiliation(s)
- Carlo Pergola
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University, Jena, Germany
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Szaingurten-Solodkin I, Hadad N, Levy R. Regulatory role of cytosolic phospholipase A2alpha in NADPH oxidase activity and in inducible nitric oxide synthase induction by aggregated Abeta1-42 in microglia. Glia 2010; 57:1727-40. [PMID: 19455582 DOI: 10.1002/glia.20886] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In Alzheimer's disease, extracellular deposits of amyloid beta(1-42) (Abeta(1-42)) may induce activation of microglial cells by releasing proinflammatory factors that contribute to the neurodegeneration process. Since the activation of cytosolic phospholipase A(2)alpha (cPLA(2)alpha) has been reported in inflammatory conditions, its role in primary rat microglial cell activated by aggregated Abeta(1-42) was elucidated. The results of the present study show that activation of microglia by 5 microM aggregated Abeta(1-42) (as evident by the amoeboid morphology and increased CD68 immunofluorescence reactivity) caused an immediate activation of cPLA(2)alpha, measured by its phosphorylated form and its specific activity, followed by a gradual elevation of its expression and activity during 24 h. Inhibition of cPLA(2)alpha expression and activity by the presence of 1 microM specific antisense resulted in a significant decrease in NADPH oxidase activity that releases superoxides, PGE(2) formation, iNOS expression, and NO production, indicating a major role for cPLA(2)alpha in the regulation of these inflammatory processes. NADPH oxidase activity, which is under cPLA(2)alpha regulation, was found to upregulate cPLA(2)alpha and COX-2 protein expression through the redox-sensitive NFkappaB activation as evident by its phosphorylation on Ser-536, resulting in increased PGE(2) formation. The secreted PGE(2) induced the synthesis of iNOS and the production of NO through the PKA-CREB pathway. Taken together, our results suggest that the response of cPLA(2)alpha to aggregated Abeta(1-42) is probably a key player in the oxidative stress present in AD, regulating potent oxidative agents: the production of superoxides by NADPH oxidase and NO formation by iNOS.
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Affiliation(s)
- I Szaingurten-Solodkin
- Infectious Diseases and Immunology Laboratory, Department of Clinical Biochemistry, Faculty of Health Sciences, Soroka University Medical Center and Ben-Gurion University of the Negev, Beer Sheva, Israel
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Shmelzer Z, Karter M, Eisenstein M, Leto TL, Hadad N, Ben-Menahem D, Gitler D, Banani S, Wolach B, Rotem M, Levy R. Cytosolic Phospholipase A2α Is Targeted to the p47 -PX Domain of the Assembled NADPH Oxidase via a Novel Binding Site in Its C2 Domain. J Biol Chem 2008; 283:31898-908. [DOI: 10.1074/jbc.m804674200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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12
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Kam AYF, Tse TTM, Kwan DHT, Wong YH. Formyl peptide receptor like 1 differentially requires mitogen-activated protein kinases for the induction of glial fibrillary acidic protein and interleukin-1α in human U87 astrocytoma cells. Cell Signal 2007; 19:2106-17. [PMID: 17643960 DOI: 10.1016/j.cellsig.2007.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 06/08/2007] [Accepted: 06/12/2007] [Indexed: 11/21/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) are not only pivotal mediators of signal transduction but they also regulate diverse biological processes ranging from survival, proliferation and differentiation to apoptosis. By using human U87 astrocytoma and transfected FPRL1/CHO cells, we have demonstrated that activation of FPRL1 with WKYMVM effectively phosphorylated JNK and ERK. Interestingly, p38 MAPK activation was only seen with FPRL1/CHO cells. The MAPK phosphorylations in response to WKYMVM were blocked by WRW(4) (a selective FPRL1 antagonist), but not cyclosporine H (a well-known FPR antagonist). The key signaling intermediates in the MAPK pathways were also delineated. G(i)/G(o) proteins, Src family tyrosine kinases, but not phosphatidylinositol-3 kinase, protein kinase C and calmodulin-dependent kinase II, were required to transmit signals from FPRL1 toward JNK, ERK and p38 MAPK. Furthermore, phospholipase Cbeta was distinctively involved in the regulation of JNK but not the other MAPKs. Importantly, WKYMVM-stimulated U87 cells triggered noticeable increases in glial fibrillary acidic protein (GFAP) and interleukin-1alpha (IL-1alpha), which are correlated with reactive astrocytosis. In contrast, GFAP expression was not altered following stimulation with N-formyl-methionyl-leucyl-phenylalanine. Moreover, inhibitions of G(i)/G(o) proteins and JNK completely abolished both GFAP and IL-1alpha upregulations by FPRL1, while blockade of the MEK/ERK cascade exclusively suppressed the GFAP production. Consistently, overexpression of MEK1 and constitutively active JNKK in U87 cells led to ERK and JNK activation, respectively, which was accompanied with markedly increased GFAP production. We have thus identified a possible linkage among FPRL1, MAPKs, astrocytic activation and the inflammatory response.
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Affiliation(s)
- Angel Y F Kam
- Department of Biochemistry, Molecular Neuroscience Center and Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Cao W, Cheng L, Behar J, Biancani P, Harnett KM. IL-1beta signaling in cat lower esophageal sphincter circular muscle. Am J Physiol Gastrointest Liver Physiol 2006; 291:G672-80. [PMID: 16645161 DOI: 10.1152/ajpgi.00110.2006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In a cat model of acute experimental esophagitis, resting in vivo lower esophageal sphincter (LES) pressure and in vitro tone are lower than in normal LES, and the LES circular smooth muscle layer contains elevated levels of IL-1beta that decrease the LES tone of normal cats. We now examined the mechanisms of IL-1beta-induced reduction in LES tone. IL-1beta significantly reduced acetylcholine-induced Ca(2+) release in Ca(2+)-free medium, and this effect was partially reversed by catalase, demonstrating a role of H(2)O(2) in these changes. IL-1beta significantly increased the production of H(2)O(2), and the increase was blocked by the p38 MAPK inhibitor SB-203580, by the cytosolic phospholipase A(2) (cPLA(2)) inhibitor AACOCF3, and by the NADPH oxidase inhibitor apocynin, but not by the MEK1 inhibitor PD-98059. IL-1beta significantly increased the phosphorylation of p38 MAPK and cPLA(2). IL-1beta-induced cPLA(2) phosphorylation was blocked by SB-203580 but not by AACOCF3, suggesting sequential activation of p38 MAPK-phosphorylating cPLA(2). The IL-1beta-induced reduction in LES tone was partially reversed by AACOCF3 and by the Ca(2+)-insensitive PLA(2) inhibitor bromoenol lactone (BEL). IL-1beta significantly increased cyclooxygenase (COX)-2 and PGE(2) levels. The increase in PGE(2) was blocked by SB-203580, AACOCF3, BEL, and the COX-2 inhibitor NS-398 but not by PD-98059 or the COX-1 inhibitor valeryl salicylate. The data suggested that IL-1beta reduces LES tone by producing H(2)O(2), which may affect Ca(2+)-release mechanisms and increase the synthesis of COX-2 and PGE(2). Both H(2)O(2) and PGE(2) production depend on sequential activation of p38 MAPK and cPLA(2). cPLA(2) activates NADPH oxidases, producing H(2)O(2), and may produce arachidonic acid, converted to PGE(2) via COX-2.
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Affiliation(s)
- Weibiao Cao
- Dept. of Medicine, Brown Medical School and Rhode Island Hospital, 55 Claverick St., Rm. 336, Providence, RI 02903, USA
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Levy R. The role of cytosolic phospholipase A2-alfa in regulation of phagocytic functions. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1323-34. [PMID: 17046321 DOI: 10.1016/j.bbalip.2006.09.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 08/14/2006] [Accepted: 09/06/2006] [Indexed: 11/16/2022]
Abstract
Phospholipase A2(s) (PLA2(s)) are a family of enzymes that is present in a variety of mammalian and nonmammalian sources. Phagocytic cells contain cytosolic PLA2 (cPLA2) as well as several types of secreted PLA2, all of which have the potential to produce proinflammatory lipid mediators. The role of the predominant form of cPLA2 present in neutrophils is cPLA2alpha was studied by many groups. By modulating its expression in a variety of phagocytes it was found that it plays a major role in formation of eicosanoids. In addition, it was reported that cPLA2alpha also regulates the NADPH oxidase activation. The specificity of its effect on the NADPH oxidase is evident by results demonstrating that the differentiation process as well as other phagocytic functions are normal in cPLA2alpha-deficient PLB cell model. The novel dual subcellular localization of cPLA2alpha in different compartments, in the plasma membranes and in the nucleus, provides a molecular mechanism for the participation of cPLA2alpha in different processes (stimulation of NADPH oxidase and formation of eicosanoids) in the same cells.
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Affiliation(s)
- Rachel Levy
- Infectious Diseases Laboratory, Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev and Soroka Medical Center, Beer Sheva 84105, Israel.
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Lee HY, Jo SH, Lee C, Baek SH, Bae YS. Differential production of leukotriene B4 or prostaglandin E2 by WKYMVm or serum amyloid A via formyl peptide receptor-like 1. Biochem Pharmacol 2006; 72:860-8. [PMID: 16859643 DOI: 10.1016/j.bcp.2006.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 06/03/2006] [Accepted: 06/15/2006] [Indexed: 10/24/2022]
Abstract
Serum amyloid A (SAA) and Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm) have been reported as formyl peptide receptor-like 1 (FPRL1) ligands. WKYMVm but not SAA stimulated superoxide generation by human neutrophils. In terms of the downstream signalings triggered by WKYMVm and SAA, both agonists stimulated cytosolic phospholipase A2-mediated arachidonic acid release, a precursor of leukotriene B4 (LTB4) and prostaglandin E2 (PGE2). WKYMVm also strongly stimulated LTB4 production in human neutrophils without affecting PGE2 production, whereas SAA strongly stimulates cyclooxygenase-2 (COX-2) expression and PGE2 production but not LTB4 production. In terms of the receptors responsible for the differential actions of these two agonists, we found that FPRL1 is involved in the production of LTB4 by WKYMVm and PGE2 production by SAA. This study demonstrates that the chemoattractant receptor, FPRL1, can be differentially regulated by distinct ligands to generate different lipid mediators, and thus, different immune responses.
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Affiliation(s)
- Ha Young Lee
- Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan, Republic of Korea
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16
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Cheng L, Cao W, Fiocchi C, Behar J, Biancani P, Harnett KM. HCl-induced inflammatory mediators in cat esophageal mucosa and inflammatory mediators in esophageal circular muscle in an in vitro model of esophagitis. Am J Physiol Gastrointest Liver Physiol 2006; 290:G1307-17. [PMID: 16439466 DOI: 10.1152/ajpgi.00576.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Platelet-activating factor (PAF) and interleukin-6 (IL-6) are produced in the esophagus in response to HCl and affect ACh release, causing changes in esophageal motor function similar to esophagitis (Cheng L, Cao W, Fiocchi C, Behar J, Biancani P, and Harnett KM. Am J Physiol Gastrointest Liver Physiol 289: G418-G428, 2005). We therefore examined HCl-activated mechanisms for production of PAF and IL-6 in cat esophageal mucosa and circular muscle. A segment of normal mucosa was tied at both ends, forming a mucosal sac (Cheng L, Cao W, Fiocchi C, Behar J, Biancani P, and Harnett KM. Am J Physiol Gastrointest Liver Physiol 289: G860-G869, 2005) that was filled with acidic Krebs buffer (pH 5.8) or normal Krebs buffer (pH 7.0) as control and kept in oxygenated Krebs buffer for 3 h. The supernatant of the acidic sac (MS-HCl) abolished contraction of normal muscle strips in response to electric field stimulation. The inhibition was reversed by the PAF antagonist CV3988 and by IL-6 antibodies. PAF and IL-6 levels in MS-HCl and mucosa were significantly elevated over control. IL-6 levels in mucosa and supernatant were reduced by CV3988, suggesting that formation of IL-6 depends on PAF. PAF-receptor mRNA levels were not detected by RT-PCR in normal mucosa, but were significantly elevated after exposure to HCl, indicating that HCl causes production of PAF and expression of PAF receptors in esophageal mucosa and that PAF causes production of IL-6. PAF and IL-6, produced in the mucosa, are released to affect the circular muscle layer. In the circular muscle, PAF causes production of additional IL-6 that activates NADPH oxidase to induce production of H(2)O(2). H(2)O(2) causes formation of IL-1beta that may induce production of PAF in the muscle, possibly closing a self-sustaining cycle of production of inflammatory mediators.
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Affiliation(s)
- Ling Cheng
- Department of Medicine, Rhode Island Hospital and Brown University, Providence, 02903, USA
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17
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Lee CG, Choi SY, Park SH, Park KS, Ryu SH, Sung YC. The synthetic peptide Trp-Lys-Tyr-Met-Val-D-Met as a novel adjuvant for DNA vaccine. Vaccine 2005; 23:4703-10. [PMID: 15936851 DOI: 10.1016/j.vaccine.2005.03.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Revised: 02/25/2005] [Accepted: 03/03/2005] [Indexed: 11/29/2022]
Abstract
Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm) is a synthetic peptide known to activate human neutrophils, monocytes and dendritic cells, resulting in the enhancement of superoxide generation, bactericidal activity, chemotactic migration and survival. In this study, we demonstrated that WKYMVm enhanced the surface expression of CD80, but not that of CD40, CD86 and MHC class II, on mouse bone marrow-derived dendritic cells which is one of the essential costimulatory signals for the induction of immune responses. Furthermore, when WKYMVm was codelivered with HIV, HBV and Influenza DNA vaccines, WKYMVm selectively enhanced the vaccine-induced CD8(+) T cell responses in a dose-dependent manner, in terms of IFN-gamma secretion and cytolytic activity. Our results indicate that a synthetic peptide, WKYMVm can function as a novel adjuvant for DNA vaccine.
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Affiliation(s)
- Chang Geun Lee
- National Research Laboratory of DNA medicine, Division of Molecular and Life Science, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk 790-784, Republic of Korea
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18
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Kang HK, Lee HY, Kim MK, Park KS, Park YM, Kwak JY, Bae YS. The synthetic peptide Trp-Lys-Tyr-Met-Val-D-Met inhibits human monocyte-derived dendritic cell maturation via formyl peptide receptor and formyl peptide receptor-like 2. THE JOURNAL OF IMMUNOLOGY 2005; 175:685-92. [PMID: 16002663 DOI: 10.4049/jimmunol.175.2.685] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm) has been reported to stimulate monocytes, neutrophils, and dendritic cells (DCs). However, although WKYMVm has been reported to function as a DC chemoattractant, its role on DC maturation has not been examined. In this study, we investigated the effects of WKYMVm on human DC maturation. The costimulation of DCs with WKYMVm and LPS dramatically inhibited LPS-induced IL-12 production, CD86 and HLA-DR surface expression, and DC-mediated T cell proliferation. However, DC phagocytic activity was increased by WKYMVm stimulation. These findings demonstrate that WKYMVm inhibits DC maturation by LPS. In terms of the mechanism underlying DC maturation inhibition by WKYMVm, we found that LPS-induced DC maturation was negatively regulated by WKYMVm-stimulated ERK activity. Moreover, the costimulation of DCs with WKYMVm and LPS dramatically inhibited the LPS-induced accumulations of IL-12 mRNA, thus suggesting that WKYMVm inhibits LPS-induced IL-12 production at the transcriptional level. We also found that DCs express two WKYMVm receptors, formyl peptide receptor (FPR) and FPR-like 2 (FPRL2). In addition, formyl-Met-Leu-Phe (a FPR ligand), Trp-Lys-Tyr-Met-Val-Met, Hp(2-20) peptide, and F2L (three FPRL2 ligands) inhibited LPS-induced IL-12 production in DCs. Taken together, our findings indicate that the activations of FPR and FPRL2 inhibit LPS-induced DC maturation, and suggest that these two receptors should be regarded as important potential therapeutic targets for the modulation of DC maturation.
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Affiliation(s)
- Hyun Kyu Kang
- Medical Research Center for Cancer Molecular Therapy and Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714, Korea
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Lee HY, Kim MK, Park KS, Shin EH, Bae YS. Group IB secretory phospholipase A2 stimulates leukotriene B4 production by a unique mechanism in human neutrophils. Biochem Biophys Res Commun 2005; 334:500-8. [PMID: 16005851 DOI: 10.1016/j.bbrc.2005.06.115] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Accepted: 06/21/2005] [Indexed: 11/30/2022]
Abstract
We found that group IB secretory phospholipase A(2) (sPLA(2)-IB) stimulates leukotriene B4 (LTB4) production in the absence of cytochalasin B in human neutrophils. Although LTB4 production has been reported to be associated with arachidonic acid release, the exogenous addition of sPLA(2)-IB did not induce this release from human neutrophils, suggesting that sPLA(2)-IB stimulates LTB4 production without affecting arachidonic acid. Moreover, the intracellular signaling events induced by sPLA(2)-IB included an increase in intracellular Ca(2+), which is required for LTB4 production. sPLA(2)-IB also stimulated mitogen-activated protein kinase ERK, but its activity was not required for LTB4 production. In terms of functional aspects, the supernatant of sPLA(2)-IB-stimulated human neutrophils caused chemotactic migration, which was almost completely inhibited by preincubating these cells with three different 5-lipoxygenase inhibitors (MK-886, AA-861, or NDGA). Taken together, we suggest that sPLA(2)-IB plays a role in the modulation of inflammatory and immune responses by inducing LTB4 production in human neutrophils.
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Affiliation(s)
- Ha Young Lee
- Medical Research Center for Cancer Molecular Therapy, College of Medicine, Dong-A University, Busan 602-714, Republic of Korea
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20
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Shin MH, Lee YA, Bae YS, Kita H, Kim Y, Ryu SH. The synthetic chemoattractant peptide WKYMVm induces superoxide production by human eosinophils via the phosphoinositide 3-kinase-mediated activation of ERK1/2. Int Arch Allergy Immunol 2005; 137 Suppl 1:21-6. [PMID: 15947481 DOI: 10.1159/000085428] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Eosinophils play a key role in allergic inflammation and parasitic infections. The synthetic peptide, Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm), has been previously shown to activate eosinophils and thus to enhance respiratory burst through the formyl peptide receptors. OBJECTIVE This study was undertaken to determine the intracellular signaling pathway involved in WKYMVm-stimulated superoxide production by human eosinophils. METHODS Purified eosinophils from peripheral blood were stimulated with various concentrations (10(-3) to 10 microM) of WKYMVm and the involvement of PI3-kinase and MAP kinases in WKYMVm-triggered superoxide production was investigated using pharmacological inhibitors. RESULTS WKYMVm-induced superoxide production by eosinophils was strongly inhibited by pretreatment with the PI3-kinase inhibitor LY294002. In addition, pretreatment with the ERK1/2 kinase inhibitor PD98059 resulted in marked inhibition of superoxide production induced by WKYMVm. Indeed, WKYMVm strongly induced phosphorylation of ERK1/2. The ERK1/2 activation by the peptide was transient and peaked after 2 min of stimulation. Furthermore, ERK1/2 activation by WKYMVm was completely inhibited by pretreatment with the PI3-kinase inhibitor LY294002, but not by the PKC inhibitor Ro-31-8220. CONCLUSION These results suggest that WKYMVm stimulates human eosinophils to induce superoxide production via a PI3-kinase-mediated ERK1/2 pathway.
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Affiliation(s)
- Myeong Heon Shin
- Department of Parasitology, Institute of Tropical Medicine and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
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21
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Kang HK, Lee HY, Lee YN, Jo EJ, Kim JI, Kim GY, Park YM, Min DS, Yano A, Kwak JY, Bae YS. Up-regulation of phospholipase Cgamma1 and phospholipase D during the differentiation of human monocytes to dendritic cells. Int Immunopharmacol 2005; 4:911-20. [PMID: 15182730 DOI: 10.1016/j.intimp.2004.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 03/30/2004] [Accepted: 04/01/2004] [Indexed: 11/26/2022]
Abstract
Phospholipase C (PLC)gamma and phospholipase D (PLD) play pivotal roles in the signal transduction required for various cellular responses, including cell proliferation and differentiation. Dendritic cells (DCs), which are professional antigen-presenting cells, can be generated from human monocytes by stimulating the cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 4 (IL-4). We investigated whether PLCgamma and PLD expression levels can be changed during the differentiation of the human monocytes into DCs. The enzymatic activity and protein level of PLC gamma1 were significantly increased in the human monocyte-derived DCs by GM-CSF/IL-4, but the protein levels of PLC gamma2 were unaltered. Moreover, the enzymatic activity and protein level of PLD1b and PLD2 were up-regulated during the differentiation of human monocytes to DCs, but those of PLD1a were not changed. A higher phagocytic activity of DCs was found to be correlated with the up-regulations of PLCgamma1 and PLD, and the phagocytic activity of DCs was inhibited by a PLC-specific inhibitor (U73122) and by a phosphatidic acid acceptor (n-butanol), but to be increased by phosphatidic acid. Thus, suggesting that PLC and PLD participate in the process. This study suggests that the up-regulations of PLCgamma1 and PLD are accompanied by the differentiation of monocytes into DCs, which results in increased phagocytic activity.
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Affiliation(s)
- Hyun Kyu Kang
- Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan 602-714, South Korea
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22
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Bae YS, Park EY, Lee HY, Kang HK, Suh PG, Kwak JY, Ryu SH, Lee T. Compounds stimulating cytosolic phospholipase A2 activity with a combinational action mode. Biochem Biophys Res Commun 2004; 325:632-8. [PMID: 15530440 DOI: 10.1016/j.bbrc.2004.10.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2004] [Indexed: 10/26/2022]
Abstract
The screening of small synthetic compound libraries is a useful means of identifying molecules that modulate various cellular responses. We screened more than 10,000 different small compounds and identified three synthetic compounds that stimulate arachidonic acid (AA) release in a combinational manner in neutrophil-like differentiated HL60 cells. These three compounds were designated as AARIC-1, -2, and -3, representing AA release inducing compounds-1, -2, and -3. Although AA release was not induced by any single one of these compounds, it was dramatically stimulated by the three compounds in combination. Moreover, the effect of combined treatment by these compounds on AA release was completely abolished by MAFP and AACOCF(3), specific cytosolic phospholipase A(2) inhibitors. Furthermore, we found that AARIC-3 stimulates cytosolic calcium influx, while AARIC-1 induces ERK activation. Taken together, we demonstrate a useful approach to the study of complicated and nonlinear intracellular signaling networks using small synthetic compounds in combination.
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Affiliation(s)
- Yoe-Sik Bae
- Medical Research Center for Cancer Molecular Therapy, College of Medicine, Dong-A University, Busan 602-714, Republic of Korea.
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23
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Offer S, Eliraz A, Fink G, Stark AH, Madar Z. Interactions between nitric oxide and arachidonic acid in lung epithelial cells: possible roles for peroxynitrite and superoxide. Pharmacology 2004; 73:155-61. [PMID: 15572879 DOI: 10.1159/000082375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Accepted: 09/21/2004] [Indexed: 11/19/2022]
Abstract
This study investigated interactions between nitric oxide synthesis and phospholipase A2 (PLA2) activation in lung epithelial cells. Nitrite formation, inducible nitric oxide synthase expression, and [3H]arachidonic acid (AA) release were determined following treatment with: (1) the nitric oxide synthase inhibitors N(G)-nitro-L-arginine methyl esther (L-NAME) and aminoguanidine; (2) arachidonyl trifluoromethyl ketone (AACOCF3), a specific cytosolic PLA2 inhibitor; (3) S-morpholinosydnonimine (SIN-1), a nitric oxide donor which provokes peroxynitrite formation; (4) trolox, a free radical scavenger, and (5) the AA release agonists calcium ionophore, phorbol 12-myristate 13-acetate, and sodium vanadate. The results demonstrated that (1) L-NAME and aminoguanidine inhibited agonist-induced AA release by 40 and 65%, respectively; (2) AACOCF3 inhibited nitrite formation and inducible nitric oxide synthase expression in a dose-dependent manner; (3) SIN-1, together with AA release agonists, significantly increased the AA output, and (4) trolox counteracted the SIN-1 effects. Our results demonstrate cross talk between nitric oxide synthase and PLA(2) pathways, with a possible intermediary role for peroxynitrite and superoxide.
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Affiliation(s)
- Sarit Offer
- Institute of Biochemistry, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
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24
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Kang HK, Lee HY, Lee YN, Jo EJ, Kim JI, Aosai F, Yano A, Kwak JY, Bae YS. Toxoplasma gondii-derived heat shock protein 70 stimulates the maturation of human monocyte-derived dendritic cells. Biochem Biophys Res Commun 2004; 322:899-904. [PMID: 15336548 DOI: 10.1016/j.bbrc.2004.07.205] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Indexed: 11/15/2022]
Abstract
We investigated the role of Toxoplasma gondii-derived heat shock protein 70 (TgHSP70) as a dendritic cell (DC) maturation-inducing molecule. TgHSP70 induced the maturation of human monocyte-derived dendritic cells as determined by increased levels of surface markers, namely, CD40, CD80, CD86, and HLA-DR. Moreover, TgHSP70 also reduced phagocytic activity and increased the allostimulatory capacity of DCs, suggesting the functional maturation of DCs by TgHSP70. Maturation of DCs by TgHSP70 also elicited a significant increase in IL-12 production in a polymyxin B-insensitive manner. TgHSP70 also stimulated extracellular signal-regulated kinase and p38 kinase pathways in DCs, and TgHSP70-induced IL-12 production was inhibited by SB203580 but not by PD98059, thus indicating the role of p38 kinase in the maturation of DCs by TgHSP70. This study demonstrates the role of TgHSP70 in the functional maturation of DCs and suggests TgHSP70 as a useful molecule for the development of a vaccine against T. gondii.
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Affiliation(s)
- Hyun Kyu Kang
- Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan 602-714, Republic of Korea
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Lee HY, Kang HK, Yoon HR, Kwak JY, Bae YS. Lysophosphatidic acid is a mediator of Trp-Lys-Tyr-Met-Val-d-Met-induced calcium influx. Biochem Biophys Res Commun 2004; 324:458-65. [PMID: 15465041 DOI: 10.1016/j.bbrc.2004.09.072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Indexed: 11/16/2022]
Abstract
Intracellular calcium (Ca(2+)) homeostasis is very strictly regulated, and the activation of G-protein-coupled receptor (GPCR) can cause two different calcium changes, intracellular calcium release, and calcium influx. In this study, we investigated the possible role of lysophosphatidic acid (LPA) on GPCR-induced Ca(2+) signaling. The addition of exogenous LPA induced dramatic Ca(2+) influx but not intracellular Ca(2+) release in U937 cells. LPA-induced Ca(2+) influx was not affected by pertussis toxin and phospholipase C inhibitor (U73122), ruling out the involvement of pertussis toxin-sensitive G-proteins, and phospholipase C. Stimulation of U937 cells with Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm), which binds to formyl peptide receptor like 1, enhanced phospholipase A(2) and phospholipase D activation, indicating LPA formation. The inhibition of LPA synthesis by phospholipase A(2)-specific inhibitor (MAFP) or n-butanol significantly inhibited WKYMVm-induced Ca(2+) influx, suggesting a crucial role for LPA in the process. Taken together, we suggest that LPA mediates WKYMVm-induced Ca(2+) influx.
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Affiliation(s)
- Ha-Young Lee
- Medical Research Center for Cancer Molecular Therapy, College of Medicine, Dong-A University, Busan 602-714, Republic of Korea
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26
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Jo EJ, Lee HY, Kim JI, Kang HK, Lee YN, Kwak JY, Bae YS. Activation of formyl peptide receptor-like 1 by WKYMVm induces serine phosphorylation of STAT3, which inhibits its tyrosine phosphorylation and nuclear translocation induced by hydrogen peroxide. Life Sci 2004; 75:2217-32. [PMID: 15325847 DOI: 10.1016/j.lfs.2004.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 04/23/2004] [Indexed: 11/28/2022]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor that modulates the expression of several genes. The activation of STAT3 accompanies tyrosine phosphorylation and its translocation to the nucleus. Formyl peptide receptor like 1 (FPRL1) is an important classical chemoattractant receptor. In this study, we observed that the stimulation of FPRL1 by Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm) caused serine phosphorylation but not tyrosine phosphorylation of STAT3 in a pertussis toxin-sensitive manner. Moreover, downstream of FPRL1 stimulation, phospholipase D (PLD) activity was dramatically increased. n-butanol, a well-known phosphatidic acid (PA) acceptor, completely inhibited WKYMVm-induced STAT3 serine phosphorylation. Moreover, the exogenous addition of PA mimicked STAT3 phosphorylation by WKYMVm. We also found that WKYMVm stimulated extracellular signal regulated kinase (ERK), and that ERK activity is required for STAT3 serine phosphorylation. This WKYMVm-induced ERK activation was inhibited by n-butanol, whereas ERK activation was also induced by the addition of exogenous PA. In terms of the functional aspects of the WKYMVm-induced serine phosphorylation of STAT3, we found that hydrogen peroxide-stimulated STAT3 activation was blocked by pretreating WKYMVm. Taken together, we found that WKYMVm stimulated FPRL1, and that this resulted in STAT3 serine phosphorylation via PLD-mediated ERK activation, and that the serine phosphorylation of STAT3 blocked hydrogen peroxide-induced STAT3 activity.
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Affiliation(s)
- Eun Jin Jo
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, 602-714, South Korea
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27
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Kim JI, Jo EJ, Lee HY, Kang HK, Lee YN, Kwak JY, Bae YS. Stimulation of early gene induction and cell proliferation by lysophosphatidic acid in human amnion-derived WISH cells: role of phospholipase D-mediated pathway. Biochem Pharmacol 2004; 68:333-40. [PMID: 15194005 DOI: 10.1016/j.bcp.2004.03.034] [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] [Received: 02/25/2004] [Accepted: 03/26/2004] [Indexed: 11/28/2022]
Abstract
Human-amniotic WISH cells express the lysophosphatidic acid (LPA) receptor, LPA(1), LPA(2) but not LPA(3). When WISH cells were stimulated with LPA, phospholipase D (PLD) activation was dramatically induced via a cytosolic calcium increase and protein kinase C activation. We also found that LPA stimulated two kinds of mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and p38 kinase via PLD-dependent signaling pathways in WISH cells. In terms of the LPA-mediated functional modulation of WISH cells, we observed that LPA stimulates the induction of two early genes (c-Jun and c-Fos) and cellular proliferation in WISH cells. We examined the signaling pathways involved in LPA-mediated cellular responses. LPA-induced early gene induction was completely blocked by normal butanol (n-butanol) but not by t-butanol, suggesting that PLD activity is essentially required for the process. PD98059 (2'-amino-3'-methoxyflavone) but not SB203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole) also significantly blocked LPA-induced early gene induction, suggesting a crucial role for ERK. Pertussis toxin (PTX) did not affect on the LPA-induced early gene induction and ERK activation, ruling out the role of Gi/o protein(s) in the process. The cellular proliferation of WISH cells was also dramatically inhibited by n-butanol or PD98059. This study demonstrates the physiological role of LPA on the modulation of early gene induction and on WISH cell proliferation, and the crucial role played by PLD in the process.
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Affiliation(s)
- Jung Im Kim
- Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan 602-714, Republic of Korea
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Bae YS, Park EY, Kim Y, He R, Ye RD, Kwak JY, Suh PG, Ryu SH. Novel chemoattractant peptides for human leukocytes. Biochem Pharmacol 2003; 66:1841-51. [PMID: 14563494 DOI: 10.1016/s0006-2952(03)00552-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phospholipase A(2) plays a key role in phagocytic cell functions. By screening a synthetic hexapeptide combinatorial library, we identified 24 novel peptides based on their ability to stimulate arachidonic acid release associated with cytosolic phospholipase A(2) activity in differentiated HL60 cells. The identified peptides, that contain the consensus sequence (K/R/M)KYY(P/V/Y)M, also induce intracellular calcium release in a pertussis toxin-sensitive manner showing specific action on phagocytic leukocytes, but not on other cells. Functionally, the peptides stimulate superoxide generation and chemotactic migration in human neutrophils and monocytes. Four of the tested active peptides were ligands for formyl peptide receptor like 1. Among these, two peptides with the consensus sequence (R/M)KYYYM can induce intracellular calcium release in undifferentiated HL60 cells that do not express formyl peptide receptor like 1, indicating usage of other receptor(s). A study of intracellular signaling in differentiated HL60 cells induced by the peptides has revealed that four of the novel peptides can induce extracellular signal-regulated protein kinase activation via shared and distinct signaling pathways, based on their dependence of phospatidylinositol-3-kinase, protein kinase C, and MEK. These peptides provide previously unavailable tools for study of differential signaling in leukocytes.
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Affiliation(s)
- Yoe-Sik Bae
- Department of Biochemistry, College of Medicine, Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan 02-714, South Korea
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29
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Bae YS, Park JC, He R, Ye RD, Kwak JY, Suh PG, Ho Ryu S. Differential signaling of formyl peptide receptor-like 1 by Trp-Lys-Tyr-Met-Val-Met-CONH2 or lipoxin A4 in human neutrophils. Mol Pharmacol 2003; 64:721-30. [PMID: 12920210 DOI: 10.1124/mol.64.3.721] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Classical chemoattractant receptors are of fundamental importance to immune responses. The two major roles of such receptors are the modulation of chemotaxis and the generation of reactive oxygen species. The formyl peptide receptor-like 1 (FPRL1) can be stimulated by two different ligands, Trp-Lys-Tyr-Met-Val-Met-CONH2 (WKYMVM) and lipoxin A4 (LXA4). Although leukocyte chemotaxis mediated by activated FPRL1 has been reported, the role of FPRL1 in superoxide generation remains to be studied. In this study, we examined the effect of WKYMVM or LXA4 on chemotactic migration and superoxide generation in human neutrophils. WKYMVM and LXA4 stimulated neutrophil chemotaxis via tyrosine phosphorylation events. In terms of reactive oxygen species generation, WKYMVM but not LXA4 stimulated superoxide generation in neutrophils. To understand this difference on superoxide generation via the same receptor, FPRL1, we compared the signaling pathways downstream of FPRL1 by the two different ligands. At first, we confirmed that both WKYMVM and LXA4 caused intracellular calcium ([Ca2+]i) increase in a pertussis toxin-sensitive manner and that these ligands competitively inhibited each other with respect to [Ca2+]i increase in neutrophils. This result suggests that WKYMVM and LXA4 share the same receptor, FPRL1. By investigating cellular signaling by WKYMVM and LXA4, we found that WKYMVM but not LXA4 induced extracellular signal-regulated protein kinases (ERKs), c-Jun NH2-terminal kinase, and phospholipase A2 (PLA2) activation. We also found that ERK-mediated cytosolic PLA2 activity is essential for superoxide generation. These results indicate that the activation of FPRL1 by the two different ligands can induce differential cellular signaling and unique functional consequences in human neutrophils.
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Affiliation(s)
- Yoe-Sik Bae
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Pohang, 790-784, Korea.
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30
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Mankelow TJ, Pessach E, Levy R, Henderson LM. The requirement of cytosolic phospholipase A2 for the PMA activation of proton efflux through the N-terminal 230-amino-acid fragment of gp91phox. Biochem J 2003; 374:315-9. [PMID: 12765544 PMCID: PMC1223598 DOI: 10.1042/bj20030495] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2003] [Revised: 05/19/2003] [Accepted: 05/23/2003] [Indexed: 11/17/2022]
Abstract
The absolute requirement for the 85 kDa cytosolic phospholipase A(2) (cPLA(2)) in the PMA stimulation of proton efflux through the NADPH-oxidase-associated proton channel, has previously been demonstrated using a PLB-985 cell line deficient in cPLA(2) (PLB-D). The flux of protons in Chinese-Hamster ovary (CHO) cells that express the N-terminal 230-amino-acid (NT) fragment of gp91(phox) is activated by arachidonic acid (AA) added externally. To investigate the physiological role of cPLA(2), and the intracellular AA that it releases, in the activation of proton flux through the NT fragment of gp91(phox), this fragment was stably expressed in PLB-985 cells (PLB-985 NT) and in PLB-D cells (PLB-D NT). The expression of the NT fragment of gp91(phox) by itself in PLB-985 did not initiate differentiation and did not alter their ability to undergo differentiation after the addition of DMSO. Addition of PMA induced a proton efflux from undifferentiated PLB-985 NT cells expressing the NT fragment of gp91(phox), which was inhibited by zinc. In contrast, PMA failed to activate proton efflux in undifferentiated PLB-D NT cells, lacking the expression of cPLA(2); however, addition of AA restored the efflux of protons in these cells. These results establish an essential and specific physiological requirement of cPLA(2)-generated AA in the activation of proton flux through the NT fragment of gp91(phox).
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Affiliation(s)
- Tosti J Mankelow
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK
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Shmelzer Z, Haddad N, Admon E, Pessach I, Leto TL, Eitan-Hazan Z, Hershfinkel M, Levy R. Unique targeting of cytosolic phospholipase A2 to plasma membranes mediated by the NADPH oxidase in phagocytes. J Cell Biol 2003; 162:683-92. [PMID: 12913107 PMCID: PMC2173789 DOI: 10.1083/jcb.200211056] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cytosolic phospholipase A2 (cPLA2)-generated arachidonic acid (AA) has been shown to be an essential requirement for the activation of NADPH oxidase, in addition to its being the major enzyme involved in the formation of eicosanoid at the nuclear membranes. The mechanism by which cPLA2 regulates NADPH oxidase activity is not known, particularly since the NADPH oxidase complex is localized in the plasma membranes of stimulated cells. The present study is the first to demonstrate that upon stimulation cPLA2 is transiently recruited to the plasma membranes by a functional NADPH oxidase in neutrophils and in granulocyte-like PLB-985 cells. Coimmunoprecipitation experiments and double labeling immunofluorescence analysis demonstrated the unique colocalization of cPLA2 and the NADPH oxidase in plasma membranes of stimulated cells, in correlation with the kinetic burst of superoxide production. A specific affinity in vitro binding was detected between GST-p47phox or GST-p67phox and cPLA2 in lysates of stimulated cells. The association between these two enzymes provides the molecular basis for AA released by cPLA2 to activate the assembled NADPH oxidase. The ability of cPLA2 to regulate two different functions in the same cells (superoxide generation and eicosanoid production) is achieved by a novel dual subcellular localization of cPLA2 to different targets.
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Affiliation(s)
- Zeev Shmelzer
- Infectious Diseases Laboratory, Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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32
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Bae YS, Lee TG, Park JC, Hur JH, Kim Y, Heo K, Kwak JY, Suh PG, Ryu SH. Identification of a compound that directly stimulates phospholipase C activity. Mol Pharmacol 2003; 63:1043-50. [PMID: 12695532 DOI: 10.1124/mol.63.5.1043] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Phosphoinositide-specific phospholipase C (PLC) plays a pivotal role in the signal transduction of various cellular responses. However, although it is undeniably important that modulators of PLC activity be identified, no direct PLC activity modulator has been identified until now. In this study, by screening more than 10,000 different compounds in human neutrophils, we identified a compound that strongly enhances superoxide-generating activity, which is well known to be PLC-dependent. The active compound 2,4,6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benzenesulfonamide (m-3M3FBS) stimulated a transient intracellular calcium concentration ([Ca(2+)](i)) increase in neutrophils. Moreover, m-3M3FBS stimulated the formation of inositol phosphates in U937 cells, indicating that it stimulates PLC activity. The compound showed no cell-type specificity in terms of [Ca(2+)](i) increase in the various cell lines including leukocytes, fibroblasts, and neuronal cells. We also ruled out the possible involvement of heterotrimeric G proteins in m-3M3FBS-stimulated signaling by confirming the following: 1) pertussis toxin does not inhibit m-3M3FBS-induced [Ca(2+)](i) increase; 2) m-3M3FBS does not stimulate cyclic AMP generation; and 3) the inhibition of G(q) by the regulator of G protein-signaling 2 does not affect the m-3M3FBS-induced [Ca(2+)](i) increase. We also observed that m-3M3FBS stimulated PLC activity in vitro. The purified isoforms of PLC that were tested (i.e., beta2, beta3, gamma1, gamma2, and delta1) were activated by m-3M3FBS and showed no isoform specificity. Taken together, these results demonstrate that m-3M3FBS modulates neutrophil functions by directly activating PLC. Because m-3M3FBS is the first compound known to directly activate PLC, it should prove useful in the study of the basic molecular mechanisms of PLC activation and PLC-mediated cell signaling.
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Affiliation(s)
- Yoe-Sik Bae
- Medical Research Center for Cancer Molecular Therapy and Department of Biochemistry, College of Medicine, Dong-A University, Busan, Korea
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Abstract
Phospholipase A2 (PLA2) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid (AA), a precursor of eicosanoids including prostaglandins and leukotrienes. The same reaction also produces lysophosholipids, which represent another class of lipid mediators. So far, at least 19 enzymes that possess PLA2 activity have been identified and cloned in mammals. The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of low-molecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense. The cytosolic PLA2 (cPLA2) family consists of three enzymes, among which cPLA2alpha has been paid much attention by researchers as an essential component of the initiation of AA metabolism. The activation of cPLA2alpha is tightly regulated by Ca2+ and phosphorylation. The Ca2+-independent PLA2 (iPLA2) family contains two enzymes and may play a major role in phospholipid remodeling. The platelet-activating factor (PAF) acetylhydrolase (PAF-AH) family contains four enzymes that exhibit unique substrate specificity toward PAF and/or oxidized phospholipids. Degradation of these bioactive phospholipids by PAF-AHs may lead to the termination of inflammatory reaction and atherosclerosis.
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Affiliation(s)
- Ichiro Kudo
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
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Bae Y, Kim Y, Park JC, Suh P, Ryu SH. The synthetic chemoattractant peptide, Trp‐Lys‐Tyr‐Met‐Val‐
d
‐Met, enhances monocyte survival via PKC‐dependent Akt activation. J Leukoc Biol 2002. [DOI: 10.1189/jlb.71.2.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Yoe‐Sik Bae
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Youndong Kim
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Jun Chul Park
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Pann‐Ghill Suh
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
| | - Sung Ho Ryu
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
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Locati M, Riboldi E, Bonecchi R, Transidico P, Bernasconi S, Haribabu B, Morris AJ, Mantovani A, Sozzani S. Selective induction of phospholipase D1 in pathogen-activated human monocytes. Biochem J 2001; 358:119-25. [PMID: 11485559 PMCID: PMC1222039 DOI: 10.1042/0264-6021:3580119] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Phospholipase D (PLD) activation is part of the complex signalling cascade induced during phagocyte activation. Two PLD isoforms have been cloned, but their role in phagocyte functions is still poorly defined. We report that resting fresh circulating human monocytes expressed PLD1. PLD1 protein expression was rapidly down-regulated during cell culture. Lipopolysaccharide and pathogen-derived agonists (Candida albicans, arabinoside-terminated lipoarabinomannan and Gram-positive bacteria, but not mannose-capped lipoarabinomannan or double-stranded RNA) strongly induced PLD1 expression at both the mRNA and protein levels. Pro-inflammatory cytokines [interleukin (IL)-1beta and tumour necrosis factor alpha] had only a weak effect, whereas immune cytokines (IL-6 and interferon gamma), anti-inflammatory cytokines (IL-13 and IL-10) and chemoattractants (fMet-Leu-Phe and macrophage chemoattractant protein 1) were inactive. None of the agonists tested induced significant changes in the basal expression of PLD2 mRNA. Consistent with PLD1 up-regulation was the observation that PLD enzymic activity was higher in monocytes treated with active-pathogen-derived agonists than in control cells, when stimulated with PMA or with chemotactic agonists (fMet-Leu-Phe and C5a). Thus PLD2 seems to be a constitutive enzyme in circulating monocytes. Conversely, PLD1 is an inducible protein, rapidly regulated during culture conditions and selectively induced during cell activation. Therefore PLD1 might have a relevant role in immune responses against pathogens and in chronic inflammation.
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Affiliation(s)
- M Locati
- Istituto di Ricerche Farmacologiche Mario Negri, via Eritrea 62, 20157 Milano, Italy
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36
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Ueno N, Murakami M, Kudo I. Functional crosstalk between phospholipase D(2) and signaling phospholipase A(2)/cyclooxygenase-2-mediated prostaglandin biosynthetic pathways. FEBS Lett 2000; 475:242-6. [PMID: 10869564 DOI: 10.1016/s0014-5793(00)01691-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We performed reconstitution analyses of functional interaction between phospholipase A(2) (PLA(2)) and phospholipase D (PLD) enzymes. Cotransfection of HEK293 cells with cytosolic (cPLA(2)) or type IIA secretory (sPLA(2)-IIA) PLA(2) and PLD(2), but not PLD(1), led to marked augmentation of stimulus-induced arachidonate release. Interleukin-1-stimulated arachidonate release was accompanied by prostaglandin E(2) production via cyclooxygenase-2, the expression of which was augmented by PLD(2). Conversely, activation of PLD(2), not PLD(1), was facilitated by cPLA(2) or sPLA(2)-IIA. Thus, our results revealed functional crosstalk between signaling PLA(2)s and PLD(2) in the regulation of various cellular responses in which these enzymes have been implicated.
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Affiliation(s)
- N Ueno
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, 142-8555, Tokyo, Japan
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