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Ma J, Zhang X, Song Y, Qin Y, Tan Y, Zheng L, Cheng B, Xi X. D609 inhibition of phosphatidylcholine-specific phospholipase C attenuates prolonged insulin stimulation-mediated GLUT4 downregulation in 3T3-L1 adipocytes. J Physiol Biochem 2022; 78:355-363. [PMID: 35048323 PMCID: PMC9242966 DOI: 10.1007/s13105-022-00872-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/06/2022] [Indexed: 11/30/2022]
Abstract
Glucose uptake is stimulated by insulin via stimulation of glucose transporter 4 (GLUT4) translocation to the plasma membrane from intracellular compartments in adipose tissue and muscles. Insulin stimulation for prolonged periods depletes GLUT4 protein, particularly in highly insulin-responsive GLUT4 storage vesicles. This depletion mainly occurs via H2O2-mediated retromer inhibition. However, the post-receptor mechanism of insulin activation of oxidative stress remains unknown. Here, we show that phosphatidylcholine-specific phospholipase C (PC-PLC) plays an important role in insulin-mediated downregulation of GLUT4. In the study, 3T3-L1 adipocytes were exposed to a PC-PLC inhibitor, tricyclodecan-9-yl-xanthogenate (D609), for 30 min prior to the stimulation with 500 nM insulin for 4 h, weakening the depletion of GLUT4. D609 also prevents insulin-driven H2O2 generation in 3T3-L1 adipocytes. Exogenous PC-PLC and its product, phosphocholine (PCho), also caused GLUT4 depletion and promoted H2O2 generation in 3T3-L1 adipocytes. Furthermore, insulin-mediated the increase in the cellular membrane PC-PLC activity was observed in Amplex Red assays. These results suggested that PC-PLC plays an important role in insulin-mediated downregulation of GLUT4 and that PCho may serve as a signaling molecule.
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Affiliation(s)
- Jinhui Ma
- Department of Endocrinology, Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Xu Zhang
- Baoding Maternal and Child Hospital, Baoding, 071000, China
| | - Yankun Song
- School of Medicine, Hebei University, Baoding, 071000, China
| | - Yan Qin
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Yinghui Tan
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Lishuang Zheng
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Baoqian Cheng
- School of Medicine, Hebei Medical University, Shijiazhuang, 050017, China
| | - Xin Xi
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, 071000, China.
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Bestard-Escalas J, Maimó-Barceló A, Pérez-Romero K, Lopez DH, Barceló-Coblijn G. Ins and Outs of Interpreting Lipidomic Results. J Mol Biol 2019; 431:5039-5062. [PMID: 31422112 DOI: 10.1016/j.jmb.2019.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 12/20/2022]
Abstract
Membrane lipids are essential for life; however, research on how cells regulate cell lipid composition has been falling behind for quite some time. One reason was the difficulty in establishing analytical methods able to cope with the cell lipid repertoire. Development of a diversity of mass spectrometry-based technologies, including imaging mass spectrometry, has helped to demonstrate beyond doubt that the cell lipidome is not only greatly cell type dependent but also highly sensitive to any pathophysiological alteration such as differentiation or tumorigenesis. Interestingly, the current popularization of metabolomic studies among numerous disciplines has led many researchers to rediscover lipids. Hence, it is important to underscore the peculiarities of these metabolites and their metabolism, which are both radically different from protein and nucleic acid metabolism. Once differences in lipid composition have been established, researchers face a rather complex scenario, to investigate the signaling pathways and molecular mechanisms accounting for their results. Thus, a detail often overlooked, but of crucial relevance, is the complex networks of enzymes involved in controlling the level of each one of the lipid species present in the cell. In most cases, these enzymes are redundant and promiscuous, complicating any study on lipid metabolism, since the modification of one particular lipid enzyme impacts simultaneously on many species. Altogether, this review aims to describe the difficulties in delving into the regulatory mechanisms tailoring the lipidome at the activity, genetic, and epigenetic level, while conveying the numerous, stimulating, and sometimes unexpected research opportunities afforded by this type of studies.
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Affiliation(s)
- Joan Bestard-Escalas
- Lipids in Human Pathology, Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain
| | - Albert Maimó-Barceló
- Lipids in Human Pathology, Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain
| | - Karim Pérez-Romero
- Lipids in Human Pathology, Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain
| | - Daniel H Lopez
- Lipids in Human Pathology, Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain
| | - Gwendolyn Barceló-Coblijn
- Lipids in Human Pathology, Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
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Lechuga-Vieco AV, Groult H, Pellico J, Mateo J, Enríquez JA, Ruiz-Cabello J, Herranz F. Protein corona and phospholipase activity drive selective accumulation of nanomicelles in atherosclerotic plaques. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2018; 14:643-650. [DOI: 10.1016/j.nano.2017.12.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/27/2017] [Accepted: 12/23/2017] [Indexed: 10/24/2022]
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Podo F, Paris L, Cecchetti S, Spadaro F, Abalsamo L, Ramoni C, Ricci A, Pisanu ME, Sardanelli F, Canese R, Iorio E. Activation of Phosphatidylcholine-Specific Phospholipase C in Breast and Ovarian Cancer: Impact on MRS-Detected Choline Metabolic Profile and Perspectives for Targeted Therapy. Front Oncol 2016; 6:171. [PMID: 27532027 PMCID: PMC4969288 DOI: 10.3389/fonc.2016.00171] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/05/2016] [Indexed: 12/12/2022] Open
Abstract
Elucidation of molecular mechanisms underlying the aberrant phosphatidylcholine cycle in cancer cells plays in favor of the use of metabolic imaging in oncology and opens the way for designing new targeted therapies. The anomalous choline metabolic profile detected in cancer by magnetic resonance spectroscopy and spectroscopic imaging provides molecular signatures of tumor progression and response to therapy. The increased level of intracellular phosphocholine (PCho) typically detected in cancer cells is mainly attributed to upregulation of choline kinase, responsible for choline phosphorylation in the biosynthetic Kennedy pathway, but can also be partly produced by activation of phosphatidylcholine-specific phospholipase C (PC-PLC). This hydrolytic enzyme, known for implications in bacterial infection and in plant survival to hostile environmental conditions, is reported to be activated in mitogen- and oncogene-induced phosphatidylcholine cycles in mammalian cells, with effects on cell signaling, cell cycle regulation, and cell proliferation. Recent investigations showed that PC-PLC activation could account for 20–50% of the intracellular PCho production in ovarian and breast cancer cells of different subtypes. Enzyme activation was associated with PC-PLC protein overexpression and subcellular redistribution in these cancer cells compared with non-tumoral counterparts. Moreover, PC-PLC coimmunoprecipitated with the human epidermal growth factor receptor-2 (HER2) and EGFR in HER2-overexpressing breast and ovarian cancer cells, while pharmacological PC-PLC inhibition resulted into long-lasting HER2 downregulation, retarded receptor re-expression on plasma membrane and antiproliferative effects. This body of evidence points to PC-PLC as a potential target for newly designed therapies, whose effects can be preclinically and clinically monitored by metabolic imaging methods.
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Affiliation(s)
- Franca Podo
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Luisa Paris
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Serena Cecchetti
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Francesca Spadaro
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Laura Abalsamo
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Carlo Ramoni
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Alessandro Ricci
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Maria Elena Pisanu
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Francesco Sardanelli
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Research Hospital Policlinico San Donato , Milan , Italy
| | - Rossella Canese
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Egidio Iorio
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
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Cecchetti S, Bortolomai I, Ferri R, Mercurio L, Canevari S, Podo F, Miotti S, Iorio E. Inhibition of Phosphatidylcholine-Specific Phospholipase C Interferes with Proliferation and Survival of Tumor Initiating Cells in Squamous Cell Carcinoma. PLoS One 2015; 10:e0136120. [PMID: 26402860 PMCID: PMC4581859 DOI: 10.1371/journal.pone.0136120] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 07/29/2015] [Indexed: 12/31/2022] Open
Abstract
Purpose The role of phosphatidylcholine-specific phospholipase C (PC-PLC), the enzyme involved in cell differentiation and proliferation, has not yet been explored in tumor initiating cells (TICs). We investigated PC-PLC expression and effects of PC-PLC inhibition in two adherent (AD) squamous carcinoma cell lines (A431 and CaSki), with different proliferative and stemness potential, and in TIC-enriched floating spheres (SPH) originated from them. Results Compared with immortalized non-tumoral keratinocytes (HaCaT) A431-AD cells showed 2.5-fold higher PC-PLC activity, nuclear localization of a 66-kDa PC-PLC isoform, but a similar distribution of the enzyme on plasma membrane and in cytoplasmic compartments. Compared with A431-AD, A431-SPH cells showed about 2.8-fold lower PC-PLC protein and activity levels, but similar nuclear content. Exposure of adherent cells to the PC-PLC inhibitor D609 (48h) induced a 50% reduction of cell proliferation at doses comprised between 33 and 50 μg/ml, without inducing any relevant cytotoxic effect (cell viability 95±5%). In A431-SPH and CaSki-SPH D609 induced both cytostatic and cytotoxic effects at about 20 to 30-fold lower doses (IC50 ranging between 1.2 and 1.6 μg/ml). Furthermore, D609 treatment of A431-AD and CaSki-AD cells affected the sphere-forming efficiency, which dropped in both cells, and induced down-modulation of stem-related markers mRNA levels (Oct4, Nestin, Nanog and ALDH1 in A431; Nestin and ALDH1 in CaSki cells). Conclusions These data suggest that the inhibition of PC-PLC activity may represent a new therapeutic approach to selectively target the most aggressive and tumor promoting sub-population of floating spheres originated from squamous cancer cells possessing different proliferative and stemness potential.
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Affiliation(s)
- Serena Cecchetti
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Ileana Bortolomai
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Renata Ferri
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Laura Mercurio
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Silvana Canevari
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
- * E-mail: (FP); (SC)
| | - Franca Podo
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
- * E-mail: (FP); (SC)
| | - Silvia Miotti
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Egidio Iorio
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
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Asymmetrical diacylglycerol dynamics on the cytosolic and lumenal sides of a single endomembrane in living cells. Sci Rep 2015; 5:12960. [PMID: 26264517 PMCID: PMC4533005 DOI: 10.1038/srep12960] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/09/2015] [Indexed: 01/04/2023] Open
Abstract
The elucidation of lipid dynamics on the cytosolic and lumenal sides of a single endomembrane has been challenging in living cells because of the lack of appropriate methods. Diacylglycerol (DAG) is a lipid second messenger that is produced by enzymes that reside on both the cytosolic and lumenal sides of the endomembrane. In the present study, we attempted to observe both the cytosolic and lumenal DAG dynamics at endomembranes including the Golgi apparatus and the endoplasmic reticulum in Madin-Darby canine kidney (MDCK) cells. We developed a Förster resonance energy transfer (FRET)–based probe to detect DAG at the luminal side (lumenal DAG) of endomembranes. In combination with the FRET-based cytosolic DAG probe that has already been established, it was found that lumenal DAG is generated in a calcium-dependent manner by thapsigargin, which increases cytosolic calcium concentrations. In contrast, DAG production at the cytosolic side of endomembranes did not occur under the same experimental conditions. The thapsigargin-induced DAG generation was abolished by treatment with an inhibitor of sphingomyelin synthase (SMS) and phosphatidylcholine-specific phospholipase C (PC-PLC), which produce lumenal DAG. Thus, we have established a successful method for monitoring both cytosolic and lumenal DAG dynamics at the endomembrane in living cells.
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7
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Ueda Y, Ishitsuka R, Hullin-Matsuda F, Kobayashi T. Regulation of the transbilayer movement of diacylglycerol in the plasma membrane. Biochimie 2014; 107 Pt A:43-50. [DOI: 10.1016/j.biochi.2014.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/09/2014] [Indexed: 12/27/2022]
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8
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The role of red blood cells in enhancing or preventing HIV infection and other diseases. BIOMED RESEARCH INTERNATIONAL 2013; 2013:758682. [PMID: 24224178 PMCID: PMC3810323 DOI: 10.1155/2013/758682] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/13/2013] [Indexed: 01/30/2023]
Abstract
Aim. To highlight the apparently neglected role of erythrocyte antigens in the epidemiology of infectious diseases, especially HIV, with the prime objective of stimulating research in this area. Method. A literature search was performed on the PubMed for relevant papers from 1984 to 2013, the era covering active HIV research. This was achieved by using the phrases “erythrocyte blood groups HIV” (81 papers) or “red cell antigen, blood groups, and HIV” (60 papers). A manual Google Scholar search was done and supplemented by original papers referenced by various authors. However, the review was limited by the relative scarcity of papers on the subject, and only papers written in English were reviewed during the period October 2012 to September 2013. Results. Many communicable and noncommunicable diseases are associated with specific blood groups. Examples of these diseases are discussed in detail. HIV has been shown to bind to erythrocytes, and candidate erythrocyte-binding molecules and mechanisms are also discussed. Moreover, erythrocyte-HIV binding is associated with increased viral infectivity, thus, underscoring the need to study this phenomenon and its implications for HIV epidemiology. Conclusion. Erythrocyte antigens may be important in the pathogenesis and epidemiology of many diseases, including HIV.
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Identification of phospholipase activity in Rhinella arenarum sperm extract capable of inducing oocyte activation. ZYGOTE 2013; 22:483-95. [PMID: 24016596 DOI: 10.1017/s0967199413000348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Egg activation, which includes cortical granule exocytosis, resumption and completion of meiosis and pronuclear formation culminates in the first mitotic cleavage. However, the mechanism through which the fertilizing sperm induces this phenomenon is still controversial. We investigated the effect of the microinjection of homologous sperm soluble fractions obtained by fast protein liquid chromatography (FPLC) from reacted sperm (without acrosome) and non-reacted sperm on the activation of Rhinella arenarum oocytes matured in vitro. The FPLC-purified sperm fraction obtained from reacted or non-reacted sperm is able to induce oocyte activation when it is microinjected. This fraction has a 24 kDa protein and showed phospholipase C (PLC) activity in vitro, which was inhibited by D-609 but not by n-butanol or neomycin, suggesting that it is a PLC that is specific for phosphatidylcholine (PC-PLC). The assays conducted using inhibitors of inositol triphosphate (IP3) and ryanodine receptors (RyRs) indicate that the fraction with biological activity would act mainly through the cADPr (cyclic ADP ribose) pathway. Moreover, protein kinase C (PKC) inhibition blocks the activation produced by the same fraction. Immunocytochemical studies indicate that this PC-PLC can be found throughout the sperm head.
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Ueda Y, Makino A, Murase‐Tamada K, Sakai S, Inaba T, Hullin‐Matsuda F, Kobayashi T. Sphingomyelin regulates the transbilayer movement of diacylglycerol in the plasma membrane of Madin‐Darby canine kidney cells. FASEB J 2013; 27:3284-97. [DOI: 10.1096/fj.12-226548] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yoshibumi Ueda
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
| | - Asami Makino
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
| | | | - Shota Sakai
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
| | - Takehiko Inaba
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
| | - Françoise Hullin‐Matsuda
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1060Université Lyon 1VilleurbanneFrance
| | - Toshihide Kobayashi
- Lipid Biology LaboratoryRikagaku Kenkyūjo (RIKEN)WakoJapan
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1060Université Lyon 1VilleurbanneFrance
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Pokotylo I, Pejchar P, Potocký M, Kocourková D, Krčková Z, Ruelland E, Kravets V, Martinec J. The plant non-specific phospholipase C gene family. Novel competitors in lipid signalling. Prog Lipid Res 2012; 52:62-79. [PMID: 23089468 DOI: 10.1016/j.plipres.2012.09.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 09/25/2012] [Accepted: 09/25/2012] [Indexed: 11/16/2022]
Abstract
Non-specific phospholipases C (NPCs) were discovered as a novel type of plant phospholipid-cleaving enzyme homologous to bacterial phosphatidylcholine-specific phospholipases C and responsible for lipid conversion during phosphate-limiting conditions. The six-gene family was established in Arabidopsis, and growing evidence suggests the involvement of two articles NPCs in biotic and abiotic stress responses as well as phytohormone actions. In addition, the diacylglycerol produced via NPCs is postulated to participate in membrane remodelling, general lipid metabolism and cross-talk with other phospholipid signalling systems in plants. This review summarises information concerning this new plant protein family and focusses on its sequence analysis, biochemical properties, cellular and tissue distribution and physiological functions. Possible modes of action are also discussed.
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Affiliation(s)
- Igor Pokotylo
- Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
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12
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Hassold N, Seystahl K, Kempf K, Urlaub D, Zekl M, Einsele H, Watzl C, Wischhusen J, Seggewiss-Bernhardt R. Enhancement of natural killer cell effector functions against selected lymphoma and leukemia cell lines by dasatinib. Int J Cancer 2012; 131:E916-27. [PMID: 22419518 DOI: 10.1002/ijc.27537] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 02/28/2012] [Indexed: 11/06/2022]
Abstract
As NK cell immunotherapy is still poorly successful, combinations with drugs enhancing NK cell activity are of major interest. NK large granular lymphocyte expansions associated with improved survival have been described under monotherapy with the Bcr-Abl/Src inhibitor dasatinib, which inhibits NK cell functions in vitro. As Src kinases play a major role in inhibitory and activating signaling pathways of NK cells, both outcomes appear plausible. To clarify these contradictory observations and potentially enable the use of dasatinib as adjuvant, we analyzed how clinically relevant doses promote NK cell effector functions. Polyclonal human NK cells were studied ex vivo. Functional outcomes assessed included conjugate formation, calcium flux, receptor regulation, cytokine production, degranulation, cytotoxicity, apoptosis induction and signal transduction. While dasatinib inhibits NK cell effector functions during functional assays, 24 hr pretreatment of NK cells followed by washout of dasatinib, led to dose-dependent enhancement of cytokine production, degranulation marker expression and cytotoxicity against selected lymphoma and leukemia cell lines. Mechanistically, this was neither due to an altered viability of NK cells nor increased NKG2D, LFA-1 or conjugate formation with target cells. Receptor proximal signaling events were inhibited. However, a slight time dependent enhancement of Vav phosphorylation was observed under certain circumstances. The shift in Vav phosphorylation level may be one major mechanism for NK cell activity enhancement induced by dasatinib. Our findings argue for a careful timing and dosing of dasatinib application during leukemia/lymphoma treatment to enhance NK cell immunotherapeutic efforts.
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Affiliation(s)
- Nicole Hassold
- Immune Recovery Section, Comprehensive Cancer Center, Department of Internal Medicine II, University of Würzburg, Würzburg, Germany
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13
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Abalsamo L, Spadaro F, Bozzuto G, Paris L, Cecchetti S, Lugini L, Iorio E, Molinari A, Ramoni C, Podo F. Inhibition of phosphatidylcholine-specific phospholipase C results in loss of mesenchymal traits in metastatic breast cancer cells. Breast Cancer Res 2012; 14:R50. [PMID: 22429397 PMCID: PMC3446384 DOI: 10.1186/bcr3151] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 03/01/2012] [Accepted: 03/19/2012] [Indexed: 02/06/2023] Open
Abstract
Introduction Acquisition of mesenchymal characteristics confers to breast cancer (BC) cells the capability of invading tissues different from primary tumor site, allowing cell migration and metastasis. Regulators of the mesenchymal-epithelial transition (MET) may represent targets for anticancer agents. Accruing evidence supports functional implications of choline phospholipid metabolism in oncogene-activated cell signaling and differentiation. We investigated the effects of D609, a xanthate inhibiting phosphatidylcholine-specific phospholipase C (PC-PLC) and sphingomyelin synthase (SMS), as a candidate regulator of cell differentiation and MET in the highly metastatic BC cell line MDA-MB-231. Methods PC-PLC expression and activity were investigated using confocal laser scanning microscopy (CLSM), immunoblotting and enzymatic assay on human MDA-MB-231 compared with MCF-7 and SKBr3 BC cells and a nontumoral immortalized counterpart (MCF-10A). The effects of D609 on PC-PLC and SMS activity, loss of mesenchymal markers and changes in migration and invasion potential were monitored in MDA-MB-231 cells by enzymatic assays, CLSM, immunoblotting and transwell chamber invasion combined with scanning electron microscopy examinations. Cell proliferation, formation and composition of lipid bodies and cell morphology were investigated in D609-treated BC cells by cell count, CLSM, flow-cytometry of BODIPY-stained cells, nuclear magnetic resonance and thin-layer chromatography. Results PC-PLC (but not phospholipase D) showed 2- to 6-fold activation in BC compared with nontumoral cells, the highest activity (up to 0.4 pmol/μg protein/min) being detected in the poorly-differentiated MDA-MB-231 cells. Exposure of the latter cells to D609 (50 μg/mL, 24-72 h) resulted into 60-80% PC-PLC inhibition, while SMS was transiently inhibited by a maximum of 21%. These features were associated with progressive decreases of mesenchymal traits such as vimentin and N-cadherin expression, reduced galectin-3 and milk fat globule EGF-factor 8 levels, β-casein formation and decreased in vitro cell migration and invasion. Moreover, proliferation arrest, changes in cell morphology and formation of cytosolic lipid bodies typical of cell differentiation were induced by D609 in all investigated BC cells. Conclusions These results support a critical involvement of PC-PLC in controlling molecular pathways responsible for maintaining a mesenchymal-like phenotype in metastatic BC cells and suggests PC-PLC deactivation as a means to promote BC cell differentiation and possibly enhance the effectiveness of antitumor treatments.
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Affiliation(s)
- Laura Abalsamo
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, Roma, 00161, Italy
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14
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Li H, Zhang L, Yin D, Zhang Y, Miao J. Targeting phosphatidylcholine-specific phospholipase C for atherogenesis therapy. Trends Cardiovasc Med 2011; 20:172-6. [PMID: 21742273 DOI: 10.1016/j.tcm.2011.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Atherosclerosis, a dynamic and progressive vascular disease arising from the combination of endothelial dysfunction and inflammation, is becoming a major killer in the 21st century. Accumulating evidence implicates phosphatidylcholine-specific phospholipase C (PC-PLC) in endothelial dysfunction and several inflammation processes. In addition, in a recent study, we demonstrated that PC-PLC contributed to the progression of atherosclerosis. Considering the important roles of PC-PLC in vascular endothelial cell dysfunction and its proinflammatory properties, we propose that a pharmacological blockade of PC-PLC represents a rational approach to atherosclerosis therapy.
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Affiliation(s)
- HaiYing Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Institute of Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
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15
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Adibhatla RM, Hatcher JF, Gusain A. Tricyclodecan-9-yl-xanthogenate (D609) mechanism of actions: a mini-review of literature. Neurochem Res 2011; 37:671-9. [PMID: 22101393 DOI: 10.1007/s11064-011-0659-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/14/2011] [Accepted: 11/10/2011] [Indexed: 12/21/2022]
Abstract
Tricyclodecan-9-yl-xanthogenate (D609) is known for its antiviral and antitumor properties. D609 actions are widely attributed to inhibiting phosphatidylcholine (PC)-specific phospholipase C (PC-PLC). D609 also inhibits sphingomyelin synthase (SMS). PC-PLC and/or SMS inhibition will affect lipid second messengers 1,2-diacylglycerol (DAG) and/or ceramide. Evidence indicates either PC-PLC and/or SMS inhibition affected the cell cycle and arrested proliferation, and stimulated differentiation in various in vitro and in vivo studies. Xanthogenate compounds are also potent antioxidants and D609 reduced Aß-induced toxicity, attributed to its antioxidant properties. Zn²⁺ is necessary for PC-PLC enzymatic activity; inhibition by D609 might be attributed to its Zn²⁺ chelation. D609 has also been proposed to inhibit acidic sphingomyelinase or down-regulate hypoxia inducible factor-1α; however these are down-stream events related to PC-PLC inhibition. Characterization of the mammalian PC-PLC is limited to inhibition of enzymatic activity (frequently measured using Amplex red assay with bacterial PC-PLC as a standard). The mammalian PC-PLC has not been cloned; sequenced and structural information is unavailable. D609 showed promise in cancer studies, reduced atherosclerotic plaques (inhibition of PC-PLC) and cerebral infarction after stroke (PC-PLC or SMS). D609 actions as an antagonist to pro-inflammatory cytokines have been attributed to PC-PLC. The purpose of this review is to comprehensively evaluate the literature and summarize the findings and relevance to cell cycle and CNS pathologies.
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Affiliation(s)
- Rao Muralikrishna Adibhatla
- Department of Neurological Surgery, Clinical Science Center, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI 53792-3232, USA.
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Podo F, Canevari S, Canese R, Pisanu ME, Ricci A, Iorio E. MR evaluation of response to targeted treatment in cancer cells. NMR IN BIOMEDICINE 2011; 24:648-672. [PMID: 21387442 DOI: 10.1002/nbm.1658] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 11/22/2010] [Accepted: 11/29/2010] [Indexed: 05/30/2023]
Abstract
The development of molecular technologies, together with progressive sophistication of molecular imaging methods, has allowed the further elucidation of the multiple mutations and dysregulatory effects of pathways leading to oncogenesis. Acting against these pathways by specifically targeted agents represents a major challenge for current research efforts in oncology. As conventional anatomically based pharmacological endpoints may be inadequate to monitor the tumor response to these targeted treatments, the identification and use of more appropriate, noninvasive pharmacodynamic biomarkers appear to be crucial to optimize the design, dosage and schedule of these novel therapeutic approaches. An aberrant choline phospholipid metabolism and enhanced flux of glucose derivatives through glycolysis, which sustain the redirection of mitochondrial ATP to glucose phosphorylation, are two major hallmarks of cancer cells. This review focuses on the changes detected in these pathways by MRS in response to targeted treatments. The progress and limitations of our present understanding of the mechanisms underlying MRS-detected phosphocholine accumulation in cancer cells are discussed in the light of gene and protein expression and the activation of different enzymes involved in phosphatidylcholine biosynthesis and catabolism. Examples of alterations induced in the MRS choline profile of cells exposed to different agents or to tumor environmental factors are presented. Current studies aimed at the identification in cancer cells of MRS-detected pharmacodynamic markers of therapies targeted against specific conditional or constitutive cell receptor stimulation are then reviewed. Finally, the perspectives of present efforts addressed to identify enzymes of the phosphatidylcholine cycle as possible novel targets for anticancer therapy are summarized.
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Affiliation(s)
- Franca Podo
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
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17
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Human prostate cell lines from normal and tumourigenic epithelia differ in the pattern and control of choline lipid headgroups released into the medium on stimulation of protein kinase C. Br J Cancer 2011; 104:673-84. [PMID: 21266973 PMCID: PMC3049586 DOI: 10.1038/sj.bjc.6606077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Background: Expression of protein kinase C alpha (PKCα) is elevated in prostate cancer (PCa); thus, we have studied whether the development of tumourigenesis in prostate epithelial cell lines modifies the normal pattern of choline (Cho) metabolite release on PKC activation. Methods: Normal and tumourigenic human prostate epithelial cell lines were incubated with [3H]-Cho to label choline phospholipids. Protein kinase C was activated with phorbol ester and blocked with inhibitors. Choline metabolites were resolved by ion-exchange chromatography. Phospholipase D (PLD) activity was measured by transphosphatidylation. Protein expression was detected by western blotting and/or RT–PCR. Choline uptake was measured on cells in monolayers over 60 min. Results: Normal prostate epithelial cell lines principally released phosphocholine (PCho) in contrast to tumourigenic lines, which released Cho. In addition, only with normal cell lines did PKC activation stimulate Cho metabolite release. Protein kinase C alpha expression varied between normal and tumourigenic cell lines but all showed a PKCα link to myristoylated alanine-rich C kinase substrate (MARCKS) protein. The five cell lines differed in Cho uptake levels, with normal PNT2C2 line cells showing highest uptake over 60 min incubation. Normal and tumourigenic cell lines expressed mRNA for PLD1 and PLD2, and showed similar levels of basal and PKC-activated PLD activity. Conclusions: The transition to tumourigenesis in prostate epithelial cell lines results in major changes to Cho metabolite release into the medium and PKC signalling to phosphatidylcholine turnover. The changes, which reflect the metabolic and proliferative needs of tumourigenic cells compared with untransformed cells, could be significant for both diagnosis and treatment.
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Zhao WJ, Zhang M, Miao Y, Yang XL, Wang Z. Melatonin potentiates glycine currents through a PLC/PKC signalling pathway in rat retinal ganglion cells. J Physiol 2010; 588:2605-19. [PMID: 20519319 PMCID: PMC2916991 DOI: 10.1113/jphysiol.2010.187641] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 05/24/2010] [Indexed: 12/15/2022] Open
Abstract
In vertebrate retina, melatonin regulates various physiological functions. In this work we investigated the mechanisms underlying melatonin-induced potentiation of glycine currents in rat retinal ganglion cells (RGCs). Immunofluorescence double labelling showed that rat RGCs were solely immunoreactive to melatonin MT(2) receptors. Melatonin potentiated glycine currents of RGCs, which was reversed by the MT(2) receptor antagonist 4-P-PDOT. The melatonin effect was blocked by intracellular dialysis of GDP-beta-S. Either preincubation with pertussis toxin or application of the phosphatidylcholine (PC)-specific phospholipase C (PLC) inhibitor D609, but not the phosphatidylinositol (PI)-PLC inhibitor U73122, blocked the melatonin effect. The protein kinase C (PKC) activator PMA potentiated the glycine currents and in the presence of PMA melatonin failed to cause further potentiation of the currents, whereas application of the PKC inhibitor bisindolylmaleimide IV abolished the melatonin-induced potentiation. The melatonin effect persisted when [Ca(2+)](i) was chelated by BAPTA, and melatonin induced no increase in [Ca(2+)](i). Neither cAMP-PKA nor cGMP-PKG signalling pathways seemed to be involved because 8-Br-cAMP or 8-Br-cGMP failed to cause potentiation of the glycine currents and both the PKA inhibitor H-89 and the PKG inhibitor KT5823 did not block the melatonin-induced potentiation. In consequence, a distinct PC-PLC/PKC signalling pathway, following the activation of G(i/o)-coupled MT(2) receptors, is most likely responsible for the melatonin-induced potentiation of glycine currents of rat RGCs. Furthermore, in rat retinal slices melatonin potentiated light-evoked glycine receptor-mediated inhibitory postsynaptic currents in RGCs. These results suggest that melatonin, being at higher levels at night, may help animals to detect positive or negative contrast in night vision by modulating inhibitory signals largely mediated by glycinergic amacrine cells in the inner retina.
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Affiliation(s)
- Wen-Jie Zhao
- Institutes of Brain Science and Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
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Inhibition of phosphatidylcholine-specific phospholipase C downregulates HER2 overexpression on plasma membrane of breast cancer cells. Breast Cancer Res 2010; 12:R27. [PMID: 20462431 PMCID: PMC2917016 DOI: 10.1186/bcr2575] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 03/18/2010] [Accepted: 05/12/2010] [Indexed: 12/21/2022] Open
Abstract
Introduction Overexpression on plasma membrane of human epidermal growth factor receptor 2 (HER2) is reported in 25% to 30% of breast cancers. Heterodimer formation with cognate members of the epidermal growth factor receptor (EGFR) family, such as HER3 and EGFR, activates abnormal cell-signalling cascades responsible for tumorigenesis and further transcriptional HER2 gene upregulation. Targeting the molecular mechanisms controlling HER2 overexpression and recycling may effectively deactivate this feedback-amplification loop. We recently showed that inactivation of phosphatidylcholine-specific phospholipase C (PC-PLC) may exert a pivotal role in selectively modulating the expression on the membrane of specific receptors or proteins relevant to cell function. In the present study, we investigated the capability of PC-PLC inhibition to target the molecular mechanisms controlling HER2 overexpression on the membrane of breast cancer cells by altering the rates of its endocytosis and lysosomal degradation. Methods Localization on the membrane and interaction of PC-PLC with HER2, EGFR, and HER3 were investigated on HER2-overexpressing and HER2-low breast cancer cell lines, by using confocal laser scanning microscopy, flow cytometry, cell-surface biotinylation, isolation of lipid rafts, and immunoprecipitation experiments. The effects of the PC-PLC inhibitor tricyclodecan-9-yl-potassium xanthate (D609) on HER2 expression on the membrane and on the levels of overall HER2, HER2-HER3, and HER2-EGFR contents were monitored in the HER2-overexpressing SKBr3 cells, after either transient or continuous receptor engagement with anti-HER2 monoclonal antibodies, including trastuzumab. Changes of HER2 expression and cell proliferation were examined in SKBr3, BT-474, and MDA-MB-453 cells continuously exposed to D609 alone or combined with trastuzumab. Results PC-PLC selectively accumulates on the plasma membrane of HER2-overexpressing cells, where it colocalizes and associates with HER2 in raft domains. PC-PLC inhibition resulted in enhanced HER2 internalization and lysosomal degradation, inducing downmodulation of HER2 expression on the membrane. Moreover, PC-PLC inhibition resulted in strong retardation of HER2 reexpression on the membrane and a decrease in the overall cellular contents of HER2, HER2-HER3, and HER2-EGFR heterodimers. The PC-PLC inhibitor also induced antiproliferative effects, especially in trastuzumab-resistant cells. Conclusions The results pointed to PC-PLC inhibition as a potential means to counteract the tumorigenic effects of HER2 amplification and complement the effectiveness of current HER2-targeting therapies.
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20
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Chen Z, Yu Y, Fu D, Li Z, Niu X, Liao M, Lu S. Functional roles of PC-PLC and Cdc20 in the cell cycle, proliferation, and apoptosis. Cell Biochem Funct 2010; 28:249-57. [DOI: 10.1002/cbf.1634] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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21
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Mateos MV, Salvador GA, Giusto NM. Selective localization of phosphatidylcholine-derived signaling in detergent-resistant membranes from synaptic endings. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1798:624-36. [PMID: 20026046 DOI: 10.1016/j.bbamem.2009.12.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 11/19/2009] [Accepted: 12/14/2009] [Indexed: 01/21/2023]
Abstract
Detergent-resistant membranes (DRMs) are a class of specialized microdomains that compartmentalize several signal transduction processes. In this work, DRMs were isolated from cerebral cortex synaptic endings (Syn) on the basis of their relative insolubility in cold Triton X-100 (1%). The lipid composition and marker protein content were analyzed in DRMs obtained from adult and aged animals. Both DRM preparations were enriched in Caveolin, Flotillin-1 and c-Src and also presented significantly higher sphingomyelin (SM) and cholesterol content than purified Syn. Total phospholipid-fatty acid composition presented an increase in 16:0 (35%), and a decrease in 20:4n-6 (67%) and 22:6n-3 (68%) content in DRM from adults when compared to entire synaptic endings. A more dramatic decrease was observed in the 20:4n-6 and 22:6n-3 content in DRMs from aged animals (80%) with respect to the results found in adults. The coexistence of phosphatidylcholine-specific-phospholipase C (PC-PLC) and phospholipase D (PLD) in Syn was previously reported. The presence of these signaling pathways was also investigated in DRMs isolated from adult and aged rats. Both PC-PLC and PLD pathways generate the lipid messenger diacylglycerol (DAG) by catalyzing PC hydrolysis. PC-PLC and PLD1 localization were increased in the DRM fraction. The increase in DAG generation (60%) in the presence of ethanol, confirmed that PC-PLC was also activated when compartmentalized in DRMs. Conversely, PLD2 was excluded from the DRM fraction. Our results show an age-related differential fatty acid composition and a selective localization of PC-derived signaling in synaptic DRMs obtained from adult and aged rats.
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Affiliation(s)
- M V Mateos
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, CC 857, B8000FWB Bahía Blanca, Argentina
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22
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Colston J, Horobin RW, Rashid-Doubell F, Pediani J, Johal KK. Why fluorescent probes for endoplasmic reticulum are selective: an experimental and QSAR-modelling study. Biotech Histochem 2009; 78:323-32. [PMID: 15473580 DOI: 10.1080/10520290310001646659] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The basis of the selectivity of fluorochromes routinely used to visualize the endoplasmic reticulum (ER) in live cells remains obscure. To clarify this, interactions of living cells with fluorochromes of varied physicochemical properties were analyzed experimentally and numerically using a quantitative structure activity relationship analysis (QSAR). Routine selective ER probes were found to be amphipathic, lipophilic cations with moderate-sized conjugated systems. The moderately lipophilic character permits probe uptake by passive diffusion without nonspecific accumulation in biomembranes. The moderately amphipathic character favors uptake into the ER, perhaps owing to its high concentration of zwitterionic lipid head-groups. The QSAR model rationalizes the impractical character of some ER probes mentioned in the literature, and could permit design of novel ER probes with different emission colors. The possibility of using the QSAR model as a tool to predict the accumulation of xenobiotics in the ER of living cells is illustrated by the localization of certain antipsychotic drugs in cultured cells.
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Affiliation(s)
- J Colston
- Institute of Biomedical & Life Sciences, West Medical Building, The University of Glasgow, Glasgow G12 8QQ, Scotland.
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Fu D, Ma Y, Wu W, Zhu X, Jia C, Zhao Q, Zhang C, Wu XZ. Cell-cycle-dependent PC-PLC regulation by APC/CCdc20-mediated ubiquitin-proteasome pathway. J Cell Biochem 2009; 107:686-96. [DOI: 10.1002/jcb.22163] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Raemer PC, Kohl K, Watzl C. Statins inhibit NK‐cell cytotoxicity by interfering with LFA‐1‐mediated conjugate formation. Eur J Immunol 2009; 39:1456-65. [DOI: 10.1002/eji.200838863] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Spadaro F, Ramoni C, Mezzanzanica D, Miotti S, Alberti P, Cecchetti S, Iorio E, Dolo V, Canevari S, Podo F. Phosphatidylcholine-Specific Phospholipase C Activation in Epithelial Ovarian Cancer Cells. Cancer Res 2008; 68:6541-9. [DOI: 10.1158/0008-5472.can-07-6763] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Ivanov AI, Hopkins AM, Brown GT, Gerner-Smidt K, Babbin BA, Parkos CA, Nusrat A. Myosin II regulates the shape of three-dimensional intestinal epithelial cysts. J Cell Sci 2008; 121:1803-14. [PMID: 18460584 DOI: 10.1242/jcs.015842] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The development of luminal organs begins with the formation of spherical cysts composed of a single layer of epithelial cells. Using a model three-dimensional cell culture, this study examines the role of a cytoskeletal motor, myosin II, in cyst formation. Caco-2 and SK-CO15 intestinal epithelial cells were embedded into Matrigel, and myosin II was inhibited by blebbistatin or siRNA-mediated knockdown. Whereas control cells formed spherical cysts with a smooth surface, inhibition of myosin II induced the outgrowth of F-actin-rich surface protrusions. The development of these protrusions was abrogated after inhibition of F-actin polymerization or of phospholipase C (PLC) activity, as well as after overexpression of a dominant-negative ADF/cofilin. Surface protrusions were enriched in microtubules and their formation was prevented by microtubule depolymerization. Myosin II inhibition caused a loss of peripheral F-actin bundles and a submembranous extension of cortical microtubules. Our findings suggest that inhibition of myosin II eliminates the cortical F-actin barrier, allowing microtubules to reach and activate PLC at the plasma membrane. PLC-dependent stimulation of ADF/cofilin creates actin-filament barbed ends and promotes the outgrowth of F-actin-rich protrusions. We conclude that myosin II regulates the spherical shape of epithelial cysts by controlling actin polymerization at the cyst surface.
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Affiliation(s)
- Andrei I Ivanov
- Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA.
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Phosphatidylcholine-specific phospholipase C activation is required for CCR5-dependent, NF-kB-driven CCL2 secretion elicited in response to HIV-1 gp120 in human primary macrophages. Blood 2008; 111:3355-63. [PMID: 18203956 DOI: 10.1182/blood-2007-08-104901] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
CCL2 (MCP-1) has been shown to enhance HIV-1 replication. The expression of this chemokine by macrophages is up-modulated as a consequence of viral infection or gp120 exposure. In this study, we show for the first time that the phosphatidylcholine-specific phospholipase C (PC-PLC) is required for the production of CCL2 triggered by gp120 in human monocyte-derived macrophages (MDMs). Using a combination of pharmacologic inhibition, confocal laser-scanner microscopy, and enzymatic activity assay, we demonstrate that R5 gp120 interaction with CCR5 activates PC-PLC, as assessed by a time-dependent modification of its subcellular distribution and a concentration-dependent increase of its enzymatic activity. Furthermore, PC-PLC is required for NF-kB-mediated CCL2 production triggered by R5 gp120. Notably, PC-PLC activation through CCR5 is specifically induced by gp120, since triggering CCR5 through its natural ligand CCL4 (MIP-1beta) does not affect PC-PLC cellular distribution and enzymatic activity, as well as CCL2 secretion, thus suggesting that different signaling pathways can be activated through CCR5 interaction with HIV-1 or chemokine ligands. The identification of PC-PLC as a critical mediator of well-defined gp120-mediated effects in MDMs unravels a novel mechanism involved in bystander activation and may contribute to define potential therapeutic targets to block Env-triggered pathologic responses.
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Cecchetti S, Spadaro F, Lugini L, Podo F, Ramoni C. Functional role of phosphatidylcholine-specific phospholipase C in regulating CD16 membrane expression in natural killer cells. Eur J Immunol 2007; 37:2912-22. [PMID: 17899539 DOI: 10.1002/eji.200737266] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
CD16, the low-affinity FcIgG receptor (FcgammaRIIIA), is predominantly expressed in human NK cells. Our recent findings indicate that CD16 expression on the outer membrane surface of NK cells is correlated with the membrane expression of phosphatidylcholine-specific phospholipase C (PC-PLC). In the present study we analyzed the trafficking of CD16 from the plasma membrane to cytoplasmic regions, after stimulation with specific mAb. The CD16 receptor is internalized, likely degraded and newly synthesized; its endocytosis is independent of ATP, but requires an integral and functional actin cytoskeleton. Antibody-mediated CD16 cross-linking results in an approximately twofold increase in PC-PLC enzymatic activity within 10 min. Analysis of PC-PLC and CD16 distribution in NK cell plasma membrane demonstrates that the proteins are physically associated and partially accumulated in lipid rafts. Pre-incubation of NK cells with a PC-PLC inhibitor, D609, causes a dramatic decrease both in CD16 receptor and PC-PLC enzyme expression on the plasma membrane. Interestingly, among phenotype PBL markers, only CD16 is strongly down-modulated by D609 treatment. CD16-mediated cytotoxicity is also reduced after D609 incubation. Taken together, these data suggest that the PC-PLC enzyme could play an important role in regulating CD16 membrane expression, the CD16-mediated cytolytic mechanism and CD16-triggered signal transduction.
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MESH Headings
- Antibodies, Monoclonal/metabolism
- Biomarkers/blood
- Cells, Cultured
- Cross-Linking Reagents/metabolism
- Cytotoxicity Tests, Immunologic
- Down-Regulation/immunology
- Humans
- Immunophenotyping
- Killer Cells, Natural/enzymology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Membrane Microdomains/enzymology
- Membrane Microdomains/immunology
- Membrane Microdomains/metabolism
- Phosphatidylcholines/metabolism
- Protein Transport/immunology
- Receptors, IgG/antagonists & inhibitors
- Receptors, IgG/biosynthesis
- Receptors, IgG/immunology
- Receptors, IgG/metabolism
- Substrate Specificity/immunology
- Type C Phospholipases/metabolism
- Type C Phospholipases/physiology
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Affiliation(s)
- Serena Cecchetti
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
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Eliyahu G, Kreizman T, Degani H. Phosphocholine as a biomarker of breast cancer: Molecular and biochemical studies. Int J Cancer 2007; 120:1721-30. [PMID: 17236204 DOI: 10.1002/ijc.22293] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The discovery of metabolic and molecular markers that help improving the detection and diagnosis of breast cancer is an important goal to be achieved. A high composite-choline signal in magnetic resonance spectra of breast lesions has been demonstrated to improve the accuracy of breast cancer diagnosis. In the present study we revealed the principal molecular and biochemical steps associated with the induction of choline metabolism and phosphocholine accumulation in human breast cancer cell-lines in comparison with normal human mammary epithelial cells. We found upregulation of the expression levels of specific choline transporters: organic cation transporter-2 and choline high affinity transporter-1, as well as of the enzyme choline kinase alpha in the cancerous cells in comparison with that in the normal mammary epithelial cells. The expression levels of choline transporter like-1, organic cation transporter-1 and choline kinase beta were similar in normal and cancerous cells. We further showed that choline transport rates and choline kinase activity indeed increased by several fold in the cancer cells leading to the elevation of phosphocholine. The results strongly suggest that phosphocholine can serve as a biomarker of breast cancer reflecting upregulation of specific choline transporters and choline kinase genes.
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Affiliation(s)
- Galit Eliyahu
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
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30
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Spadaro F, Cecchetti S, Sanchez M, Ausiello CM, Podo F, Ramoni C. Expression and role of phosphatidylcholine-specific phospholipase C in human NK and T lymphocyte subsets. Eur J Immunol 2006; 36:3277-87. [PMID: 17111345 DOI: 10.1002/eji.200635927] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We recently reported evidence of phosphatidylcholine-specific phospholipase C (PC-PLC) involvement in NK cell-mediated cytotoxicity and in lytic granule exocytosis. In the present study, different subpopulations of human PBL were investigated in relation to PC-PLC enzyme expression. While a substantial intracellular amount of PC-PLC was detected in all lymphoid subsets, expression of this enzyme on the outer membrane surface reached high levels only in NK cells, was present at low levels in B lymphocytes and in some TCR gamma/delta T cells and was practically absent in CD4(+) and CD8(+ )T lymphocytes. Moreover, in NK cells two different subpopulations were identified, CD56(dim) PC-PLC(bright) and CD56(bright) PC-PLC(low/-) cells, corresponding to distinct subsets with cytolytic and immunoregulatory functions, respectively. Interestingly, the PC-PLC expression level on the NK membrane surface correlated closely with that of the CD16 receptor, suggesting a possible relationship between enzyme externalization and NK cell maturation. In summary, our results suggest that a high PC-PLC expression on the cell membrane surface of PBL is a peculiarity of NK cytolytic cells, in which the enzyme is apparently involved in the ability of this subset to lyse sensitive target cells.
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Affiliation(s)
- Francesca Spadaro
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
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31
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Rose TM, Prestwich GD. Synthesis and evaluation of fluorogenic substrates for phospholipase D and phospholipase C. Org Lett 2006; 8:2575-8. [PMID: 16737317 PMCID: PMC2535796 DOI: 10.1021/ol060773d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorogenic analogues of phosphatidylcholine and lysophosphatidylcholine, DDPB and lysoDDPB, were synthesized by an enzyme-assisted strategy. The analogues were evaluated as substrates for phospholipases C and D and lysophospholipase D. DDPB was cleaved by bacterial and plant phospholipase D (PLD) enzymes and represents the first direct fluorogenic substrate for real-time measurement of PLD activity. Both fluorogenic substrates have potential in screening for PLD and PC-PLC inhibitors and for monitoring spatiotemporal changes in PLD activity in cells. [structure: see text]
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Affiliation(s)
- Tyler M. Rose
- Department of Medicinal Chemistry, University of Utah, 419 Wakara Way, Suite 205, Salt Lake City, UT 84108
| | - Glenn D. Prestwich
- Department of Medicinal Chemistry, University of Utah, 419 Wakara Way, Suite 205, Salt Lake City, UT 84108
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32
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Mateos MV, Uranga RM, Salvador GA, Giusto NM. Coexistence of phosphatidylcholine-specific phospholipase C and phospholipase D activities in rat cerebral cortex synaptosomes. Lipids 2006; 41:273-80. [PMID: 16711602 DOI: 10.1007/s11745-006-5097-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
DAG derived from phosphatidylcholine (PtdCho) acts as a lipid second messenger. It can be generated by the activation of phospholipase D (PLD) and the phosphatidic acid phosphohydrolase type 2 (PAP2) pathway or by a PtdCho-specific phospholipase C (PtdCho-PLC). Our purpose was to study PtdCho-PLC activity in rat cerebral cortex synaptosomes (CC Syn). DAG production was highly stimulated by detergents such as Triton X-100 and sodium deoxycholate. Ethanol and tricyclodecan-9-yl-xanthate potassium salt decreased DAG generation by 42 and 61%, respectively, at 20 min of incubation. These data demonstrate that both the PLD/PAP2 pathway and PtdCho-PLC contribute to DAG generation in CC Syn. PtdCho-PLC activity remained located mainly in the synaptosomal plasma membrane fraction. Kinetic studies showed Km and Vmax values of 350 microM and 3.7 nmol DAG x (mg protein x h)(-1), respectively. Western blot analysis with anti-PtdCho-PLC antibody showed a band of 66 KDa in CC Syn. Our results indicate the presence of a novel DAG-generating pathway in CC Syn in addition to the known PLD/PAP2 pathway.
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Affiliation(s)
- Melina V Mateos
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, CC 857, B8000FWB Bahía Blanca, Argentina
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Ramoni C, Spadaro F, Barletta B, Dupuis ML, Podo F. Phosphatidylcholine-specific phospholipase C in mitogen-stimulated fibroblasts. Exp Cell Res 2004; 299:370-82. [PMID: 15350536 DOI: 10.1016/j.yexcr.2004.05.037] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2003] [Revised: 04/22/2004] [Indexed: 11/18/2022]
Abstract
To investigate expression, subcellular localization and mechanisms of translocation of phosphatidylcholine-specific phospholipase C (PC-PLC) during the cell proliferative response, biochemical, immunoblotting, and immunofluorescence analyses were performed on quiescent and mitogen-stimulated NIH-3T3 fibroblasts. Platelet-derived growth factor (PDGF), insulin and 12-O-tetradecanoylphorbol-13-acetate induced, in 10-60 min, PC-PLC translocation from a perinuclear cytoplasmic area to the plasma membrane. Following cell exposure to PDGF (60 min), the overall PC-PLC expression increased up to 2-3x, while the enzyme activity increased 5x in total cell lysates, 2x in the plasma membrane, and 4x in the nucleus; moreover, confocal laser scanning microscopy showed a progressive externalization of PC-PLC on the outer plasma membrane surface and its accumulation in the nuclear matrix. Pre-incubation of cells with the PC-PLC inhibitor tricyclodecan-9-yl potassium xanthate (D609), before PDGF-stimulation, not only reduced the enzyme activity in total cell lysates as well as in plasma membrane and nuclear fractions, but also blocked the mechanisms of PC-PLC subcellular redistribution. These effects were associated with a D609-induced long-lasting cell cycle block in Go.
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Affiliation(s)
- Carlo Ramoni
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
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Andrei C, Margiocco P, Poggi A, Lotti LV, Torrisi MR, Rubartelli A. Phospholipases C and A2 control lysosome-mediated IL-1 beta secretion: Implications for inflammatory processes. Proc Natl Acad Sci U S A 2004; 101:9745-50. [PMID: 15192144 PMCID: PMC470745 DOI: 10.1073/pnas.0308558101] [Citation(s) in RCA: 315] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Blocking the activity of IL-1 beta has entered the clinical arena of treating autoimmune diseases. However, a successful outcome of this approach requires a clear definition of the mechanisms controlling IL-1 beta release. These are still unclear as IL-1 beta, lacking a secretory signal peptide, follows a nonclassical pathway of secretion. Here, we analyze the molecular mechanism(s) undergoing IL-1 beta processing and release in human monocytes and provide a unifying model for the regulated secretion of the cytokine. Our data show that in a first step, pro-caspase-1 and endotoxin-induced pro-IL-1 beta are targeted in part to specialized secretory lysosomes, where they colocalize with other lysosomal proteins. Externalization of mature IL-1 beta and caspase-1 together with lysosomal proteins is then facilitated by extracellular ATP. ATP triggers the efflux of K(+) from the cell, followed by Ca(2+) influx and activation of three phospholipases: phosphatidylcholine-specific phospholipase C and calcium-independent and -dependent phospholipase A(2). Whereas calcium-independent phospholipase A(2) is involved in processing, phosphatidylcholine-specific phospholipase C and calcium-dependent phospholipase A(2) are required for secretion. Dissection of the events that follow ATP triggering allowed to demonstrate that K(+) efflux is responsible for phosphatidylcholine-specific phospholipase C induction, which in turn allows the rise in intracellular free calcium concentration required for activation of phospholipase A(2). This activation is ultimately responsible for lysosome exocytosis and IL-1 beta secretion.
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Affiliation(s)
- Cristina Andrei
- Cell Transport Unit, Department of Oncogenesis, National Cancer Research Institute, 16132 Genoa, Italy
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35
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Fantuzzi L, Spadaro F, Vallanti G, Canini I, Ramoni C, Vicenzi E, Belardelli F, Poli G, Gessani S. Endogenous CCL2 (monocyte chemotactic protein-1) modulates human immunodeficiency virus type-1 replication and affects cytoskeleton organization in human monocyte-derived macrophages. Blood 2003; 102:2334-7. [PMID: 12805068 DOI: 10.1182/blood-2002-10-3275] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CC chemokine ligand 2 (CCL2) is constitutively expressed at high levels in human peripheral blood monocytes, and its expression is further up-modulated during their differentiation into macrophages as well as in the course of HIV infection. To investigate the role of endogenous CCL2 on HIV replication and macrophage function, CCL2's activity was neutralized by specific antibodies. Infection of monocyte-derived macrophages with laboratory-adapted HIV-1 or primary viral isolates in the continuous presence of anti-CCL2 antibody resulted in significantly lower p24 Gag antigen release with respect to control cultures. Interestingly, CCL2 neutralization did not affect the early steps of the HIV life cycle but resulted in the intracellular accumulation of p24 Gag antigen. Simultaneously, remarkable changes in cell morphology and size occurred in cell cultures maintained in the presence of anti-CCL2 antibody. These results suggest that CCL2 may represent an autocrine factor important for enhancing virion production likely by affecting the macrophage cytoskeleton.
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Affiliation(s)
- Laura Fantuzzi
- Laboratory of Virology, Istituto Superiore di Sanità, Rome, Italy
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36
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Piccolella E, Spadaro F, Ramoni C, Marinari B, Costanzo A, Levrero M, Thomson L, Abraham RT, Tuosto L. Vav-1 and the IKK alpha subunit of I kappa B kinase functionally associate to induce NF-kappa B activation in response to CD28 engagement. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:2895-903. [PMID: 12626540 DOI: 10.4049/jimmunol.170.6.2895] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have recently observed that CD28 engagement initiates a signaling pathway leading to the activation of I kappa B kinase (IKK) complex and, consequently, to NF-kappa B activation, and we identified Vav-1 as an important mediator of this function. Here we report for the first time that Vav-1 constitutively associates with IKK alpha in both Jurkat and primary CD4(+) T cells. Vav-1/IKK alpha association is mediated by their helix-loop-helix domains, does not involve IKK beta, and is functionally relevant in that Vav-1-associated IKK alpha kinase activity is increased following CD28 engagement by B7. Moreover, we demonstrate that CD28-induced NF-kappa B activation is augmented by both IKK alpha and Vav-1, but not IKK beta. Confocal microscopy showed that endogenous Vav-1 and IKK alpha, but not IKK beta, were recruited to the membrane and colocalized in response to CD28 stimulation. Taken together, these data evidence that Vav-1 plays a key role in the control of NF-kappa B pathway by targeting IKK alpha in the T cell membrane and favoring its activation in response to CD28 stimulation.
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Affiliation(s)
- Enza Piccolella
- Department of Cellular and Developmental Biology, University of Rome La Sapienza, Rome, Italy
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Lande R, Giacomini E, Grassi T, Remoli ME, Iona E, Miettinen M, Julkunen I, Coccia EM. IFN-alpha beta released by Mycobacterium tuberculosis-infected human dendritic cells induces the expression of CXCL10: selective recruitment of NK and activated T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1174-82. [PMID: 12538673 DOI: 10.4049/jimmunol.170.3.1174] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We recently reported that dendritic cells (DC) infected with Mycobacterium tuberculosis (Mtb) produce Th1/IFN-gamma-inducing cytokines, IFN-alpha beta and IL-12. In the present article, we show that maturing Mtb-infected DC express high levels of CCR7 and they become responsive to its ligand CCL21. Conversely, CCR5 expression was rapidly lost from the cell surface following Mtb infection. High levels of CCL3 and CCL4 were produced within 8 h after infection, which is likely to account for the observed CCR5 down-modulation on Mtb-infected DC. In addition, Mtb infection stimulated the secretion of CXCL9 and CXCL10. Interestingly, the synthesis of CXCL10 was mainly dependent on the Mtb-induced production of IFN-alpha beta. Indeed, IFN-alpha beta neutralization down-regulated CXCL10 expression, whereas the expression of CXCL9 appeared to be unaffected. The chemotactic activity of the Mtb-infected DC supernatants was evaluated by migration assays using activated NK, CD4(+), and CD8(+) cells that expressed both CCR5 and CXCR3. Mtb-induced expression of CCL3, CCL4, CXCL9, and CXCL10 was involved in the stimulation of NK and T cell migration. In accordance with the data on the IFN-alpha beta-induced expression of CXCL10, neutralization of IFN-alpha beta significantly reduced the chemotactic activity of the supernatant from Mtb-infected DC. This indicates that IFN-alpha beta may modulate the immune response through the expression of CXCL10, which along with CXCL9, CCL3, and CCL4 participates in the recruitment and selective homing of activated/effector cells, which are known to accumulate at the site of Mtb infection and take part in the formation of the granulomas.
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Affiliation(s)
- Roberto Lande
- Laboratory of Immunology, Istituto Superiore di Sanità, Rome, Italy
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Pun WK, Chow SP, Fang D, Cheng CL, Leong JC, Ng C. Post-traumatic oedema of the foot after tibial fracture. Expert Rev Mol Diagn 1990; 15:735-47. [PMID: 2592102 DOI: 10.1586/14737159.2015.1039515] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A total of 97 patients with diaphyseal tibial fractures treated with functional bracing were studied prospectively. Persistent ipsilateral foot swelling was present in 84.5 per cent of the patients. Most of the swellings subsided with time, but a small percentage of them persisted for a duration of 2 years or more after injury. The time for disappearance of the swelling in 50 per cent of the patients was 18.6 weeks. The development of oedema is not related to the age and sex of the patients, the configuration, type and level of the fractures, or the association of a fibular fracture. The bone healed quicker in those who did not have swelling of the foot. Once the swelling has developed, it seems to run its own course and its disappearance is not related to the age and sex, the configuration, type and level of fractures, the association of a fibular fracture, or the time for fracture healing. This complication does not have any adverse effect on the functional recovery of the patients.
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Affiliation(s)
- W K Pun
- Department of Orthopaedic Surgery, University of Hong Kong, Queen Mary Hospital
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