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Ranzato E, Bonsignore G, Patrone M, Martinotti S. Endothelial and Vascular Health: A Tale of Honey, H 2O 2 and Calcium. Cells 2021; 10:cells10051071. [PMID: 33946572 PMCID: PMC8147193 DOI: 10.3390/cells10051071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022] Open
Abstract
Intracellular Ca2+ regulation plays a pivotal role in endothelial biology as well as during endothelial restoration processes. Interest in honey utilization in wound approaches is rising in recent years. In order to evaluate the positive effects of buckwheat honey on endothelial responses, we utilized an immortalized endothelial cell line to evaluate cellular responses upon honey exposure, with particular interest in Ca2+ signaling involvement. The results highlight the positive effects of buckwheat honey on endothelial cells’ responses and the central role played by Ca2+ signaling as an encouraging target for more efficacious clinical treatments.
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Affiliation(s)
- Elia Ranzato
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (E.R.); (G.B.); (M.P.)
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Piazza Sant’Eusebio 5, 13100 Vercelli, Italy
| | - Gregorio Bonsignore
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (E.R.); (G.B.); (M.P.)
| | - Mauro Patrone
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (E.R.); (G.B.); (M.P.)
| | - Simona Martinotti
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (E.R.); (G.B.); (M.P.)
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Piazza Sant’Eusebio 5, 13100 Vercelli, Italy
- Correspondence: ; Tel.: +39-0131-360260
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Inaba H, Miao Q, Nakata T. Optogenetic control of small GTPases reveals RhoA mediates intracellular calcium signaling. J Biol Chem 2021; 296:100290. [PMID: 33453281 PMCID: PMC7949103 DOI: 10.1016/j.jbc.2021.100290] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/06/2021] [Accepted: 01/11/2021] [Indexed: 01/05/2023] Open
Abstract
Rho/Ras family small GTPases are known to regulate numerous cellular processes, including cytoskeletal reorganization, cell proliferation, and cell differentiation. These processes are also controlled by Ca2+, and consequently, cross talk between these signals is considered likely. However, systematic quantitative evaluation has not yet been reported. To fill this gap, we constructed optogenetic tools to control the activity of small GTPases (RhoA, Rac1, Cdc42, Ras, Rap, and Ral) using an improved light-inducible dimer system (iLID). We characterized these optogenetic tools with genetically encoded red fluorescence intensity-based small GTPase biosensors and confirmed these optogenetic tools’ specificities. Using these optogenetic tools, we investigated calcium mobilization immediately after small GTPase activation. Unexpectedly, we found that a transient intracellular calcium elevation was specifically induced by RhoA activation in RPE1 and HeLa cells. RhoA activation also induced transient intracellular calcium elevation in MDCK and HEK293T cells, suggesting that generally RhoA induces calcium signaling. Interestingly, the molecular mechanisms linking RhoA activation to calcium increases were shown to be different among the different cell types: In RPE1 and HeLa cells, RhoA activated phospholipase C epsilon (PLCε) at the plasma membrane, which in turn induced Ca2+ release from the endoplasmic reticulum (ER). The RhoA–PLCε axis induced calcium-dependent nuclear factor of activated T cells nuclear translocation, suggesting that it does activate intracellular calcium signaling. Conversely, in MDCK and HEK293T cells, RhoA–ROCK–myosin II axis induced the calcium transients. These data suggest universal coordination of RhoA and calcium signaling in cellular processes, such as cellular contraction and gene expression.
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Affiliation(s)
- Hironori Inaba
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Qianqian Miao
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takao Nakata
- Department of Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan; The Center for Brain Integration Research (CBIR), Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
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Jimenez I, Prado Y, Marchant F, Otero C, Eltit F, Cabello-Verrugio C, Cerda O, Simon F. TRPM Channels in Human Diseases. Cells 2020; 9:E2604. [PMID: 33291725 PMCID: PMC7761947 DOI: 10.3390/cells9122604] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential melastatin (TRPM) subfamily belongs to the TRP cation channels family. Since the first cloning of TRPM1 in 1989, tremendous progress has been made in identifying novel members of the TRPM subfamily and their functions. The TRPM subfamily is composed of eight members consisting of four six-transmembrane domain subunits, resulting in homomeric or heteromeric channels. From a structural point of view, based on the homology sequence of the coiled-coil in the C-terminus, the eight TRPM members are clustered into four groups: TRPM1/M3, M2/M8, M4/M5 and M6/M7. TRPM subfamily members have been involved in several physiological functions. However, they are also linked to diverse pathophysiological human processes. Alterations in the expression and function of TRPM subfamily ion channels might generate several human diseases including cardiovascular and neurodegenerative alterations, organ dysfunction, cancer and many other channelopathies. These effects position them as remarkable putative targets for novel diagnostic strategies, drug design and therapeutic approaches. Here, we review the current knowledge about the main characteristics of all members of the TRPM family, focusing on their actions in human diseases.
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Affiliation(s)
- Ivanka Jimenez
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Yolanda Prado
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Felipe Marchant
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Carolina Otero
- Faculty of Medicine, School of Chemistry and Pharmacy, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Felipe Eltit
- Vancouver Prostate Centre, Vancouver, BC V6Z 1Y6, Canada;
- Department of Urological Sciences, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | - Claudio Cabello-Verrugio
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago 7560484, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| | - Oscar Cerda
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Felipe Simon
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
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Huang W, Carr AJ, Hajicek N, Sokolovski M, Siraliev-Perez E, Hardy PB, Pearce KH, Sondek J, Zhang Q. A High-Throughput Assay to Identify Allosteric Inhibitors of the PLC-γ Isozymes Operating at Membranes. Biochemistry 2020; 59:4029-4038. [PMID: 33028071 DOI: 10.1021/acs.biochem.0c00511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The two phospholipase C-γ (PLC-γ) isozymes are major signaling hubs and emerging therapeutic targets for various diseases, yet there are no selective inhibitors for these enzymes. We have developed a high-throughput, liposome-based assay that features XY-69, a fluorogenic, membrane-associated reporter for mammalian PLC isozymes. The assay was validated using a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) in 384-well format; it is highly reproducible and has the potential to capture both orthosteric and allosteric inhibitors. Selected hit compounds were confirmed with secondary assays, and further profiling led to the interesting discovery that adenosine triphosphate potently inhibits the PLC-γ isozymes through noncompetitive inhibition, raising the intriguing possibility of endogenous, nucleotide-dependent regulation of these phospholipases. These results highlight the merit of the assay platform for large scale screening of chemical libraries to identify allosteric modulators of the PLC-γ isozymes as chemical probes and for drug discovery.
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Han C, Xia K, Yang J, Zhang H, DeLisa MP, Liang X. Investigation of lipid profile in Acetobacter pasteurianus Ab3 against acetic acid stress during vinegar production. Extremophiles 2020; 24:909-922. [PMID: 33026498 DOI: 10.1007/s00792-020-01204-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 09/21/2020] [Indexed: 10/23/2022]
Abstract
Elucidation of the acetic acid resistance (AAR) mechanisms of Acetobacter pasteurianus is significant for vinegar production. In this study, cell membrane lipid profile of A. pasteurianus Ab3 was investigated by gas chromatography-mass spectrometer (GC-MS) and high performance liquid chromatography-electrospray ionization (HPLC-ESI) combined with high resolution accurate mass/mass spectrometry (HRAM/MS). We observed that cell remodeled the membrane physical state by decreasing the ratio of saturated fatty acids (SFAs)/unsaturated fatty acids (UFAs), and increasing the chain length of fatty acids (FAs) and the content of cyclopropane FAs in response to extreme acid stress. Noticeably, the content of octadecadienoic acid (C18:2) elevated remarkably. Moreover, a continuous reduction in cell membrane fluidity and a "V-type" variance in permeability were discovered. The content of glycerophospholipid and ceramide increased significantly in cells harvested from culture with acidity of 75 g/L and 95 g/L compared to that with acidity of 30 g/L. Among the identified lipid species, the content of phosphatidylcholine (e.g. PC 19:0/18:2 and 19:1/18:0), ceramide (e.g. Cer d18:0/16:1 and d18:0/16:1 + O), and dimethylphosphatidylethanolamine (e.g. dMePE 19:1/16:1) increased notably with increasing acidity. Collectively, these findings refresh our current understanding of the AAR mechanisms in A. pasteurianus Ab3, and should direct future strain breeding and vinegar fermentation.
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Affiliation(s)
- Chengcheng Han
- Department of Biochemical Engineering, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Kai Xia
- Department of Biochemical Engineering, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Jieqiong Yang
- Department of Biochemical Engineering, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Hong Zhang
- Department of Biochemical Engineering, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Matthew P DeLisa
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, NY, 14853, USA
| | - Xinle Liang
- Department of Biochemical Engineering, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China.
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Martinotti S, Patrone M, Balbo V, Mazzucco L, Ranzato E. Endothelial response boosted by platelet lysate: the involvement of calcium toolkit. Int J Mol Sci 2020; 21:ijms21030808. [PMID: 31991927 PMCID: PMC7036775 DOI: 10.3390/ijms21030808] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 12/26/2022] Open
Abstract
Wound repair is a dynamic process during which crucial signaling pathways are regulated by growth factors and cytokines released by several kinds of cells directly involved in the healing process. However, the limited applications and heterogeneous clinical results of single growth factors in wound healing encouraged the use of a mixture of bioactive molecules such as platelet derivatives for best results in wound repair. An interesting platelet derivative, obtained from blood samples, is platelet lysate (PL), which has shown potential clinical application. PL is obtained from freezing and thawing of platelet-enriched blood samples. Intracellular calcium (Ca2+) signals play a central role in the control of endothelial cell survival, proliferation, motility, and differentiation. We investigated the role of Ca2+ signaling in the PL-driven endothelial healing process. In our experiments, the functional significance of Ca2+ signaling machinery was highlighted performing the scratch wound assay in presence of different inhibitors or specific RNAi. We also pointed out that the PL-induced generation of intracellular ROS (reactive oxygen species) via NOX4 (NADPH oxidase 4) is necessary for the activation of TRPM2 and the resulting Ca2+ entry from the extracellular space. This is the first report of the mechanism of wound repair in an endothelial cell model boosted by the PL-induced regulation of [Ca2+]i.
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Affiliation(s)
- Simona Martinotti
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (M.P.); (E.R.)
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, piazza Sant’Eusebio 5, 13100 Vercelli, Italy
- Correspondence: ; Tel.: +39-0131-360260; Fax: +39-0131-360243
| | - Mauro Patrone
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (M.P.); (E.R.)
| | - Valeria Balbo
- Laboratorio Produzione Emocomponenti e Medicina Rigenerativa, SIMT—AO “SS Antonio e Biagio”, 15121 Alessandria, Italy; (V.B.); (L.M.)
| | - Laura Mazzucco
- Laboratorio Produzione Emocomponenti e Medicina Rigenerativa, SIMT—AO “SS Antonio e Biagio”, 15121 Alessandria, Italy; (V.B.); (L.M.)
| | - Elia Ranzato
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, 15121 Alessandria, Italy; (M.P.); (E.R.)
- DiSIT—Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, piazza Sant’Eusebio 5, 13100 Vercelli, Italy
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Simonowski A, Wilhelm T, Habib P, Zorn CN, Huber M. Differential use of BTK and PLC in FcεRI- and KIT-mediated mast cell activation: A marginal role of BTK upon KIT activation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118622. [PMID: 31837347 DOI: 10.1016/j.bbamcr.2019.118622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 11/16/2019] [Accepted: 12/08/2019] [Indexed: 02/04/2023]
Abstract
In mast cells (MCs), the TEC family kinase (TFK) BTK constitutes a central regulator of antigen (Ag)-triggered, FcεRI-mediated PLCγ phosphorylation, Ca2+ mobilization, degranulation, and pro-inflammatory cytokine production. Less is known about the function of BTK in the context of stem cell factor (SCF)-induced KIT signaling. In bone marrow-derived MCs (BMMCs), Ag stimulation caused intense phosphorylation of BTK at Y551 in its active center and at Y223 in its SH3-domain, whereas in response to SCF only Y223 was significantly phosphorylated. Further data using the TFK inhibitor Ibrutinib indicated that BTK Y223 is phosphorylated by a non-BTK TFK upon SCF stimulation. In line, SCF-induced PLCγ1 phosphorylation was stronger attenuated by Ibrutinib than by BTK deficiency. Subsequent pharmacological analysis of PLCγ function revealed a total block of SCF-induced Ca2+ mobilization by PLC inhibition, whereas only the sustained phase of Ca2+ flux was curtailed in Ag-stimulated BMMCs. Despite this severe stimulus-dependent difference in inducing Ca2+ mobilization, PLCγ inhibition suppressed Ag- and SCF-induced degranulation and pro-inflammatory cytokine production to comparable extents, suggesting involvement of additional TFK(s) or PLCγ-dependent signaling components. In addition to PLCγ, the MAPKs p38 and JNK were activated by Ag in a BTK-dependent manner; this was not observed upon SCF stimulation. Hence, FcεRI and KIT employ different mechanisms for activating PLCγ, p38, and JNK, which might strengthen their cooperation regarding pro-inflammatory MC effector functions. Importantly, our data clearly demonstrate that analyzing BTK Y223 phosphorylation is not sufficient to prove BTK activation.
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Affiliation(s)
- Anne Simonowski
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Thomas Wilhelm
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Pardes Habib
- Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Carolin N Zorn
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Michael Huber
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany.
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Johnson AA. Lipid Hydrolase Enzymes: Pragmatic Prolongevity Targets for Improved Human Healthspan? Rejuvenation Res 2019; 23:107-121. [PMID: 31426688 DOI: 10.1089/rej.2019.2211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Compelling evidence suggests that lipid metabolism, which plays critical roles in fat storage, cell membrane maintenance, and cell signaling, is intricately linked to aging. Lipid hydrolases are important enzymes that catalyze the hydrolysis of more complex lipids into simpler lipids. Diverse interventions targeting lipid hydrolases can prolong or shorten life in model organisms. For example, the genetic removal of or RNAi knockdown against a phospholipase can reduce lifespan in Caenorhabditis elegans, Drosophila melanogaster, and Mus musculus. The removal of lysosomal acid lipase results in premature death in mice, while its overexpression in nematodes generates lean, long-lived individuals. The overexpression or inhibition of diacylglycerol lipase leads to enhanced or reduced longevity, respectively, in both worms and flies. Lifespan can also be extended by knocking down triacylglycerol lipases in yeast, overexpressing fatty acid amide hydrolase in worms, or removing hepatic lipase in a mouse model of coronary disease. Conversely, flies lacking the triacylglycerol lipase Brummer are obese and short lived. Linking sphingolipids and aging, removing the sphingomyelinase inositol phosphosphingolipid phospholipase shortens chronological lifespan in Saccharomyces cerevisiae, while inhibiting an acid sphingomyelinase in worms or inactivating alkaline ceramidase in flies extends lifespan. The clinical potential of manipulating these enzymes is highlighted by the FDA-approved obesity drug orlistat, which is an inhibitor of pancreatic and hepatic lipases that induces weight loss and improves insulin/glucose homeostasis. Additional research is warranted to better understand how these lipid hydrolases impact aging and to determine if clinical interventions targeting them are capable of improving human healthspan.
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Guo Y, Lv Q, Zou XQ, Yan ZX, Yan YX. Mechanical Strain Regulates Osteoblast Proliferation Through Ca 2+-CaMK-CREB Signal Pathway. ACTA ACUST UNITED AC 2018; 31:100-106. [PMID: 28031098 DOI: 10.1016/s1001-9294(16)30033-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Objective To investigate the effects of mechanical strain on Ca2+-calmodulin dependent kinase (CaMK)-cAMP response element binding protein (CREB) signal pathway and proliferation of osteoblasts.Methods Using a four-point bending device, MC3T3-E1 cells were exposed to mechanical tensile strains of 2500 µs and 5000 µs at 0.5 Hz respectively. The intracellular free Ca2+ ([Ca2+]i) concentration and calmodulin activity were assayed by fluorospectrophotometry, CaMK II β, CREB, and phosphorylated (activated) CREB (p-CREB) were assessed by Western blot, and cells proliferation was assayed with MTT. Pretreatment with verapamil was carried out to block Ca2+ channel, and inhibitor U73122 was used to inhibit phospholipase C (PLC).Results Mechanical strains of 2500 µs and 5000 µs for 1 to 10 minutes both increased [Ca2+]i level of the cells. The 2500 µs strain, a periodicity of 1 h/d for 3 days, activated calmodulin, elevated protein levels of CaMK II β and p-CREB, and promoted cells proliferation, which were attenuated by pretreatment of verapamil or U73122. The effects of 5000 µs strain on calmodulin, CaMK II β, p-CREB and proliferation were contrary to 2500 µs strain.Conclusion The mechanical strain regulates osteoblasts proliferation through Ca2+-CaMK-CREB signal pathway via Ca2+ channel and PLC/IP3 transduction cascades.
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Affiliation(s)
- Yong Guo
- Depantment of Bioengineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, China; Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, China
| | - Qi Lv
- Experiment Management Center, Logistical College of People Armed Police Forces, Tianjin 300162, China
| | - Xian-Qiong Zou
- Depantment of Bioengineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, China
| | - Zhi-Xiong Yan
- Depantment of Bioengineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, China
| | - Yu-Xian Yan
- Depantment of Bioengineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, China; Experiment Management Center, Logistical College of People Armed Police Forces, Tianjin 300162, China
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Leitner MG, Michel N, Behrendt M, Dierich M, Dembla S, Wilke BU, Konrad M, Lindner M, Oberwinkler J, Oliver D. Direct modulation of TRPM4 and TRPM3 channels by the phospholipase C inhibitor U73122. Br J Pharmacol 2016; 173:2555-69. [PMID: 27328745 DOI: 10.1111/bph.13538] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 06/10/2016] [Accepted: 06/15/2016] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND AND PURPOSE Signalling through phospholipase C (PLC) controls many cellular processes. Much information on the relevance of this important pathway has been derived from pharmacological inhibition of the enzymatic activity of PLC. We found that the most frequently employed PLC inhibitor, U73122, activates endogenous ionic currents in widely used cell lines. Given the extensive use of U73122 in research, we set out to identify these U73122-sensitive ion channels. EXPERIMENTAL APPROACH We performed detailed biophysical analysis of the U73122-induced currents in frequently used cell lines. KEY RESULTS At concentrations required to inhibit PLC, U73122 modulated the activity of transient receptor potential melastatin (TRPM) channels through covalent modification. U73122 was shown to be a potent agonist of ubiquitously expressed TRPM4 channels and activated endogenous TRPM4 channels in CHO cells independently of PLC and of the downstream second messengers PI(4,5)P2 and Ca(2+) . U73122 also potentiated Ca(2) (+) -dependent TRPM4 currents in human Jurkat T-cells, endogenous TRPM4 in HEK293T cells and recombinant human TRPM4. In contrast to TRPM4, TRPM3 channels were inhibited whereas the closely related TRPM5 channels were insensitive to U73122, showing that U73122 exhibits high specificity within the TRPM channel family. CONCLUSIONS AND IMPLICATIONS Given the widespread expression of TRPM4 and TRPM3 channels, these actions of U73122 must be considered when interpreting its effects on cell function. U73122 may also be useful for identifying and characterizing TRPM channels in native tissue, thus facilitating the analysis of their physiology.
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Affiliation(s)
- Michael G Leitner
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Niklas Michel
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Marc Behrendt
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Marlen Dierich
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Sandeep Dembla
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Bettina U Wilke
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Maik Konrad
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Moritz Lindner
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Johannes Oberwinkler
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
| | - Dominik Oliver
- Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps-University Marburg, Marburg, Germany
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11
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Kim CS, Mitchell IP, Desotell AW, Kreeger PK, Masters KS. Immobilized epidermal growth factor stimulates persistent, directed keratinocyte migration via activation of PLCγ1. FASEB J 2016; 30:2580-90. [PMID: 27025961 DOI: 10.1096/fj.201600252] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/21/2016] [Indexed: 01/19/2023]
Abstract
Epidermal growth factor (EGF) is a critical element in dermal repair, but EGF-containing wound dressings have not been successful clinically. However, these dressings have delivered only soluble EGF, and the native environment provides both soluble and matrix-bound EGF. To address our hypothesis that tethered EGF can stimulate cell behaviors not achievable with soluble EGF, we examined single-cell movement and signaling in human immortalized HaCaT keratinocytes treated with soluble or immobilized EGF. Although both EGF treatments increased collective sheet displacement and individual cell speed, only cells treated with immobilized EGF exhibited directed migration, as well as 2-fold greater persistence compared with soluble EGF. Immunofluorescence showed altered EGF receptor (EGFR) trafficking, where EGFR remained membrane-localized in the immobilized EGF condition. Cells treated with soluble EGF demonstrated higher phosphorylated ERK1/2, and cells on immobilized EGF exhibited higher pPLCγ1, which was localized at the leading edge. Treatment with U0126 inhibited migration in both conditions, demonstrating that ERK1/2 activity was necessary but not responsible for the observed differences. In contrast, PLCγ1 inhibition with U73122 significantly decreased persistence on immobilized EGF. Combined, these results suggest that immobilized EGF increases collective keratinocyte displacement via an increase in single-cell migration persistence resulting from altered EGFR trafficking and PLCγ1 activation.-Kim, C. S., Mitchell, I. P., Desotell, A. W., Kreeger, P. K., Masters, K. S. Immobilized epidermal growth factor stimulates persistent, directed keratinocyte migration via activation of PLCγ1.
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Affiliation(s)
- Chloe S Kim
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Isaiah P Mitchell
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Anthony W Desotell
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Pamela K Kreeger
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kristyn S Masters
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
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12
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Gorai S, Bagdi PR, Borah R, Paul D, Santra MK, Khan AT, Manna D. Insights into the inhibitory mechanism of triazole-based small molecules on phosphatidylinositol-4,5-bisphosphate binding pleckstrin homology domain. Biochem Biophys Rep 2015; 2:75-86. [PMID: 29124147 PMCID: PMC5668642 DOI: 10.1016/j.bbrep.2015.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/11/2022] Open
Abstract
Background Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is an important regulator of several cellular processes and a precursor for other second messengers which are involved in cell signaling pathways. Signaling proteins preferably interact with PI(4,5)P2 through its pleckstrin homology (PH) domain. Efforts are underway to design small molecule-based antagonist, which can specifically inhibit the PI(4,5)P2/PH-domain interaction to establish an alternate strategy for the development of drug(s) for phosphoinositide signaling pathways. Methods Surface plasmon resonance, molecular docking, circular dichroism, competitive Förster resonance energy transfer, isothermal titration calorimetric analyses and liposome pull down assay were used. Results In this study, we employed 1,2,3-triazol-4-yl methanol containing small molecule (CIPs) as antagonists for PI(4,5)P2/PH-domain interaction and determined their inhibitory effect by using competitive-surface plasmon resonance analysis (IC50 ranges from 53 to 159 nM for PI(4,5)P2/PLCδ1-PH domain binding assay). We also used phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3], phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2], PI(4,5)P2 specific PH-domains to determine binding selectivity of the compounds. Various physicochemical analyses showed that the compounds have weak affect on fluidity of the model membrane but, strongly interact with the phospholipase C δ1 (PLCδ1)-PH domains. The 1,2,3-triazol-4-yl methanol moiety and nitro group of the compounds are essential for their exothermic interaction with the PH-domains. Potent compound can efficiently displace PLCδ1-PH domain from plasma membrane to cytosol in A549 cells. Conclusions Overall, our studies demonstrate that these compounds interact with the PIP-binding PH-domains and inhibit their membrane recruitment. General significance These results suggest specific but differential binding of these compounds to the PLCδ1-PH domain and emphasize the role of their structural differences in binding parameters. These triazole-based compounds could be directly used/further developed as potential inhibitor for PH domain-dependent enzyme activity.
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Affiliation(s)
- Sukhamoy Gorai
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Prasanta Ray Bagdi
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Rituparna Borah
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Debasish Paul
- National Center for Cell Science, Pune 411007, Maharashtra, India
| | | | - Abu Taleb Khan
- Alia University, DN 18, 8th Floor, Sector V, Kolkata 700091, India
| | - Debasis Manna
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
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13
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Kamato D, Thach L, Bernard R, Chan V, Zheng W, Kaur H, Brimble M, Osman N, Little PJ. Structure, Function, Pharmacology, and Therapeutic Potential of the G Protein, Gα/q,11. Front Cardiovasc Med 2015; 2:14. [PMID: 26664886 PMCID: PMC4671355 DOI: 10.3389/fcvm.2015.00014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/11/2015] [Indexed: 11/19/2022] Open
Abstract
G protein coupled receptors (GPCRs) are one of the major classes of cell surface receptors and are associated with a group of G proteins consisting of three subunits termed alpha, beta, and gamma. G proteins are classified into four families according to their α subunit; Gαi, Gαs, Gα12/13, and Gαq. There are several downstream pathways of Gαq of which the best known is upon activation via guanosine triphosphate (GTP), Gαq activates phospholipase Cβ, hydrolyzing phosphatidylinositol 4,5-biphosphate into diacylglycerol and inositol triphosphate and activating protein kinase C and increasing calcium efflux from the endoplasmic reticulum. Although G proteins, in particular, the Gαq/11 are central elements in GPCR signaling, their actual roles have not yet been thoroughly investigated. The lack of research of the role on Gαq/11 in cell biology is partially due to the obscure nature of the available pharmacological agents. YM-254890 is the most useful Gαq-selective inhibitor with antiplatelet, antithrombotic, and thrombolytic effects. YM-254890 inhibits Gαq signaling pathways by preventing the exchange of guanosine diphosphate for GTP. UBO-QIC is a structurally similar compound to YM-254890, which can inhibit platelet aggregation and cause vasorelaxation in rats. Many agents are available for the study of signaling downstream of Gαq/11. The role of G proteins could potentially represent a novel therapeutic target. This review will explore the range of pharmacological and molecular tools available for the study of the role of Gαq/11 in GPCR signaling.
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Affiliation(s)
- Danielle Kamato
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Lyna Thach
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Rebekah Bernard
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Vincent Chan
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Wenhua Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre , Guangzhou , China ; Faculty of Health Sciences, University of Macau , Macau , China
| | - Harveen Kaur
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Margaret Brimble
- Department of Chemistry, University of Auckland , Auckland , New Zealand
| | - Narin Osman
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
| | - Peter J Little
- Discipline of Pharmacy, Diabetes Complications Group, School of Medical Sciences, Health Innovations Research Institute, RMIT University , Bundoora, VIC , Australia
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Bak HJ, Kim MS, Kim NY, Lee AR, Park JH, Lee JY, Kim BS, Ahn SJ, Lee HH, Chung JK. Expression analysis and enzymatic characterization of phospholipase Cδ4 from olive flounder (Paralichthys olivaceus). Comp Biochem Physiol B Biochem Mol Biol 2013; 166:215-24. [PMID: 24029817 DOI: 10.1016/j.cbpb.2013.09.001] [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: 05/20/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 10/26/2022]
Abstract
Phospholipase Cδ4 (PLCδ4) plays a significant role in cell proliferation, tumorigenesis, and in an early stage of fertilization. Despite the characterization of the mammalian PLCδ4, extensive study in aquatic organisms has not been carried out so far. Here, we performed the molecular and biochemical characterization of flatfish Paralichthys olivaceus PLCδ4 (PoPLCδ4) to understand its enzymatic properties and physiological functions. The olive flounder PLCδ4 cDNA has an open reading frame (ORF) of 2,268 bp, and encodes a 755 amino acid polypeptide with a predicted molecular weight of 86 kDa. All the characteristic domains found in mammalian PLCδ isoforms (PH domain, EF hands, an X-Y catalytic region, and a C2 domain) were found to be present in PoPLCδ4. The mRNA expression analysis of PoPLCδ4 showed that PoPLCδ4 is predominantly expressed in the brain, eye and heart tissues. Like other mammalian PLCδ proteins, the enzyme activity of recombinant PoPLCδ4 to phosphatidylinositol-4,5-bis-phosphate (PIP2) was noted to be concentration- and Ca(2+)-dependent. The structural features and biochemical characteristics of PoPLCδ4 were found to be similar to those of mammalian PLCδ4. This is the first demonstration of the expression analysis and enzymatic characterization of piscine PLCδ4.
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Affiliation(s)
- Hye Jin Bak
- Department of Biotechnology, Pukyong National University, Busan 608-737, South Korea
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15
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Inflammatory lipid sphingosine-1-phosphate upregulates C-reactive protein via C/EBPβ and potentiates breast cancer progression. Oncogene 2013; 33:3583-93. [PMID: 23955082 DOI: 10.1038/onc.2013.319] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/20/2013] [Indexed: 12/25/2022]
Abstract
A crucial role of the inflammatory lipid sphingosine-1-phosphate (S1P) in breast cancer aggressiveness has been reported. Recent clinical studies have suggested that C-reactive protein (CRP) has a role in breast cancer development. However, limited information is available on the molecular basis for the expression of CRP and its functional significance in breast cell invasion. The present study aimed to elucidate the molecular link between S1P and CRP during the invasive process of breast epithelial cells. This is the first report showing that transcription of CRP was markedly activated by S1P in breast cells. Our data suggest that not only S1P treatment but also the endogenously produced S1P may upregulate CRP in breast carcinoma cells. Transcription factors CCAAT/enhancer-binding protein beta and c-fos were required for S1P-induced CRP expression. Coupling of S1P3 to heterotrimeric Gαq triggered the expression of CRP, utilizing signaling pathways involving reactive oxygen species (ROS), Ca(2+) and extracellular signal-related kinases (ERKs). S1P-induced CRP expression was crucial for the transcriptional activation of matrix metalloproteinase-9 through ERKs, ROS and c-fos, leading to breast cell invasion. Using a xenograft mice tumor model, we demonstrated that S1P induced CRP expression both in vitro and in vivo. Taken together, our findings have revealed a molecular basis for S1P-induced transcriptional activation of CRP and its functional significance in the acquisition of the invasive phenotype of human breast epithelial cells under inflammatory conditions. Our findings may provide useful information on the identification of useful therapeutic targets for inflammatory breast cancer.
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Djafi N, Vergnolle C, Cantrel C, Wietrzyñski W, Delage E, Cochet F, Puyaubert J, Soubigou-Taconnat L, Gey D, Collin S, Balzergue S, Zachowski A, Ruelland E. The Arabidopsis DREB2 genetic pathway is constitutively repressed by basal phosphoinositide-dependent phospholipase C coupled to diacylglycerol kinase. FRONTIERS IN PLANT SCIENCE 2013; 4:307. [PMID: 23964284 PMCID: PMC3737466 DOI: 10.3389/fpls.2013.00307] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 07/22/2013] [Indexed: 05/02/2023]
Abstract
Phosphoinositide-dependent phospholipases C (PI-PLCs) are activated in response to various stimuli. They utilize substrates provided by type III-Phosphatidylinositol-4 kinases (PI4KIII) to produce inositol triphosphate and diacylglycerol (DAG) that is phosphorylated into phosphatidic acid (PA) by DAG-kinases (DGKs). The roles of PI4KIIIs, PI-PLCs, and DGKs in basal signaling are poorly understood. We investigated the control of gene expression by basal PI-PLC pathway in Arabidopsis thaliana suspension cells. A transcriptome-wide analysis allowed the identification of genes whose expression was altered by edelfosine, 30 μM wortmannin, or R59022, inhibitors of PI-PLCs, PI4KIIIs, and DGKs, respectively. We found that a gene responsive to one of these molecules is more likely to be similarly regulated by the other two inhibitors. The common action of these agents is to inhibit PA formation, showing that basal PI-PLCs act, in part, on gene expression through their coupling to DGKs. Amongst the genes up-regulated in presence of the inhibitors, were some DREB2 genes, in suspension cells and in seedlings. The DREB2 genes encode transcription factors with major roles in responses to environmental stresses, including dehydration. They bind to C-repeat motifs, known as Drought-Responsive Elements that are indeed enriched in the promoters of genes up-regulated by PI-PLC pathway inhibitors. PA can also be produced by phospholipases D (PLDs). We show that the DREB2 genes that are up-regulated by PI-PLC inhibitors are positively or negatively regulated, or indifferent, to PLD basal activity. Our data show that the DREB2 genetic pathway is constitutively repressed in resting conditions and that DGK coupled to PI-PLC is active in this process, in suspension cells and seedlings. We discuss how this basal negative regulation of DREB2 genes is compatible with their stress-triggered positive regulation.
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Affiliation(s)
- Nabila Djafi
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Chantal Vergnolle
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Catherine Cantrel
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | | | - Elise Delage
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Françoise Cochet
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Juliette Puyaubert
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Ludivine Soubigou-Taconnat
- Unité de Recherche en Biologie Végétale, UMR INRA 1165, Université d'Evry Val d'Essonne, ERL CNRS 8196Evry Cedex, France
| | - Delphine Gey
- Unité de Recherche en Biologie Végétale, UMR INRA 1165, Université d'Evry Val d'Essonne, ERL CNRS 8196Evry Cedex, France
| | - Sylvie Collin
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Sandrine Balzergue
- Unité de Recherche en Biologie Végétale, UMR INRA 1165, Université d'Evry Val d'Essonne, ERL CNRS 8196Evry Cedex, France
| | - Alain Zachowski
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
| | - Eric Ruelland
- Physiologie Cellulaire et Moléculaire des Plantes, CNRS EAC7180Paris, France
- Physiologie Cellulaire et Moléculaire des Plantes, UPMC-Univ Paris06 UR5Paris, France
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17
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(4-Phenoxyphenyl)tetrazolecarboxamides and related compounds as dual inhibitors of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Eur J Med Chem 2013; 63:64-75. [DOI: 10.1016/j.ejmech.2013.01.050] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/11/2013] [Accepted: 01/15/2013] [Indexed: 01/19/2023]
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18
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Functional analysis of duplicated genes and N-terminal splice variant of phospholipase C-δ1 in Paralichthys olivaceus. Comp Biochem Physiol B Biochem Mol Biol 2013; 165:201-10. [PMID: 23629421 DOI: 10.1016/j.cbpb.2013.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 04/22/2013] [Accepted: 04/22/2013] [Indexed: 11/22/2022]
Abstract
Phosphoinositide-specific phospholipase C δ (PLC δ) plays an important role in many cellular responses and is involved in the production of second messenger. Here, we describe the presence of novel N-terminal extended alternative splice form of PLC-δ1B in Paralichthys olivaceus, which differs from the reported mammalian PLC-δ1 isoform. The two variants PoPLC-δ1B-Lf and PoPLC-δ1B-Sf share exon 3 (including the PH domain) to exon 16, but differ at the exon 1 (Short form: Sf) and novel exon 2 (Long form: Lf) of the transcript. For the characterization of the novel duplicated gene variant of PLC-δ1B in P. olivaceus, tissue-specific expression with RT-PCR and real-time PCR, and purification and enzymatic characterization of native and recombinant proteins of all the three-types of PLC-δ1 isoforms (PoPLC-δ1A, PoPLC-δ1B-Lf and PoPLC-δ1B-Sf) of P. olivaceus were studied. The PoPLC-δ1A was ubiquitously distributed in gill, kidney and spleen. The PoPLC-δ1B-Lf gene was widely detected in various tissues, especially in the digestive system, while PoPLC-δ1B-Sf was highly expressed in the stomach. The recombinant PoPLC-δ1A, PoPLC-δ1B-Lf and PoPLC-δ1B-Sf proteins were expressed as a histidine-tagged fusion protein in Escherichia coli. The PLC activity of the PoPLC-δ1 isoform proteins showed a concentration-dependent activity to phosphatidylinositol (PI) and phosphatidylinositol 4,5-bisphosphate (PIP(2)). In addition, U73122, the PLC inhibitor, effectively inhibited PLC activities of PoPLC-δ1A, PoPLC-δ1B-Lf and PoPLC-δ1B-Sf proteins. However, PoPLC-δ1A and PoPLC-δ1B-Lf were sensitive at pH 7.5, while PoPLC-δ1B-Sf was relatively sensitive at pH 7. These results might be useful for the study of phospholipase C-mediated signal transduction in fish.
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Huang W, Barrett M, Hajicek N, Hicks S, Harden TK, Sondek J, Zhang Q. Small molecule inhibitors of phospholipase C from a novel high-throughput screen. J Biol Chem 2013; 288:5840-8. [PMID: 23297405 DOI: 10.1074/jbc.m112.422501] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Phospholipase C (PLC) isozymes are important signaling molecules, but few small molecule modulators are available to pharmacologically regulate their function. With the goal of developing a general approach for identification of novel PLC inhibitors, we developed a high-throughput assay based on the fluorogenic substrate reporter WH-15. The assay is highly sensitive and reproducible: screening a chemical library of 6280 compounds identified three novel PLC inhibitors that exhibited potent activities in two separate assay formats with purified PLC isozymes in vitro. Two of the three inhibitors also inhibited G protein-coupled receptor-stimulated PLC activity in intact cell systems. These results demonstrate the power of the high-throughput assay for screening large collections of small molecules to identify novel PLC modulators. Potent and selective modulators of PLCs will ultimately be useful for dissecting the roles of PLCs in cellular processes, as well as provide lead compounds for the development of drugs to treat diseases arising from aberrant phospholipase activity.
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Affiliation(s)
- Weigang Huang
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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20
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Brkić L, Riederer M, Graier WF, Malli R, Frank S. Acyl chain-dependent effect of lysophosphatidylcholine on cyclooxygenase (COX)-2 expression in endothelial cells. Atherosclerosis 2012; 224:348-54. [PMID: 22901457 PMCID: PMC3465554 DOI: 10.1016/j.atherosclerosis.2012.07.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/10/2012] [Accepted: 07/25/2012] [Indexed: 11/19/2022]
Abstract
Objective Previously we identified palmitoyl-, oleoyl- linoleoyl-, and arachidonoyl-lysophosph-atidylcholine (LPC 16:0, 18:1, 18:2 and 20:4) as the most prominent LPC species generated by endothelial lipase (EL). In the present study, we examined the capacity of those LPC to modulate expression of cyclooxygenase (COX)-2 in vascular endothelial cells. Methods & results LPC 16:0 and 20:4 promoted both COX-2 mRNA- and protein synthesis with different potencies and kinetics. While LPC 18:1 induced a weak and transient increase in COX-2 mRNA, but not protein, LPC 18:2 increased COX-2 protein, without impacting mRNA. Chelation of intracellular Ca2+ and inhibition of p38 MAPK markedly attenuated 16:0 LPC- and 20:4 LPC- elicited induction of COX-2 expression, whereas inhibition of phospholipase C (PLC) attenuated only the effect of 16:0 LPC. LPC 16:0 and 20:4 differed markedly in their potencies to increase cytosolic Ca2+ concentration and in the kinetics of p38 MAPK activation. While the effects of 16:0 and 20:4 LPC on COX-2 expression were profoundly sensitive to silencing of either c-Jun or p65 (NF-κB), respectively, silencing of cyclic AMP responsive element binding protein (CREB) attenuated markedly the effect of both LPC. Conclusion Our results indicate that the tested LPC species are capable of inducing COX-2 expression, whereby the efficacy and the relative contribution of underlying signaling mechanisms markedly differ, due to the length and degree of saturation of LPC acyl chains.
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Affiliation(s)
- Lada Brkić
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Harrachgasse 21/III, Medical University Graz, 8010 Graz, Austria
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Adibhatla RM. Distinction between phosphatidylcholine (PC)–specific phospholipase C (PC–PLC) and phosphatidylinositol (PI)–specific phospolipase C (PI–PLC) needs clarification. Biochem Biophys Res Commun 2012; 419:447; author reply 448-9. [DOI: 10.1016/j.bbrc.2012.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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22
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Ehrlich LS, Medina GN, Carter CA. ESCRT machinery potentiates HIV-1 utilization of the PI(4,5)P(2)-PLC-IP3R-Ca(2+) signaling cascade. J Mol Biol 2011; 413:347-58. [PMID: 21875593 PMCID: PMC3193579 DOI: 10.1016/j.jmb.2011.08.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 08/05/2011] [Accepted: 08/16/2011] [Indexed: 01/09/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) release efficiency is directed by late (L) domain motifs in the viral structural precursor polyprotein Gag, which serve as links to the ESCRT (endosomal sorting complex required for transport) machinery. Linkage is normally through binding of Tsg101, an ESCRT-1 component, to the P(7)TAP motif in the p6 region of Gag. In its absence, budding is directed by binding of Alix, an ESCRT adaptor protein, to the LY(36)PX(n)L motif in Gag. We recently showed that budding requires activation of the inositol 1,4,5-triphosphate receptor (IP3R), a protein that "gates" Ca(2+) release from intracellular stores, triggers Ca(2+) cell influx and thereby functions as a major regulator of Ca(2+) signaling. In the present study, we determined whether the L domain links Gag to Ca(2+) signaling machinery. Depletion of IP3R and inactivation of phospholipase C (PLC) inhibited budding whether or not Tsg101 was bound to Gag. PLC hydrolysis of phosphatidylinositol-(4,5)-bisphosphate generates inositol (1,4,5)-triphosphate, the ligand that activates IP3R. However, with Tsg101 bound, Gag release was independent of Gq-mediated activation of PLC, and budding was readily enhanced by pharmacological stimulation of PLC. Moreover, IP3R was redistributed to the cell periphery and cytosolic Ca(2+) was elevated, events indicative of induction of Ca(2+) signaling. The results suggest that L domain function, ESCRT machinery and Ca(2+) signaling are linked events in Gag release.
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Affiliation(s)
- Lorna S. Ehrlich
- Dept. of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Gisselle N. Medina
- Dept. of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Carol A. Carter
- Dept. of Molecular Genetics & Microbiology, Stony Brook University, Stony Brook, NY 11794-5222, USA
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Donadeu FX, Esteves CL, Doyle LK, Walker CA, Schauer SN, Diaz CA. Phospholipase Cβ3 mediates LH-induced granulosa cell differentiation. Endocrinology 2011; 152:2857-69. [PMID: 21586561 DOI: 10.1210/en.2010-1298] [Citation(s) in RCA: 18] [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: 11/19/2022]
Abstract
Previous studies showed that under certain conditions LH can stimulate not only adenylate cyclase (AC) but also phospholipase Cβ (PLCβ) signaling in target cells; however, the physiological involvement of PLCβ in LH-induced ovarian follicular cell differentiation has not been determined. To address this, ex vivo expression analyses and specific PLCβ targeting were performed in primary bovine granulosa cells. Expression analyses in cells from small (2.0-5.9 mm), medium (6.0-9.9 mm), and ovulatory-size (10.0-13.9 mm) follicles revealed an increase in mRNA and protein levels of heterotrimeric G protein subunits-αs, -αq, -α11, and -αi2 in ovulatory-size follicles, simultaneous with a substantial increase in LH receptor expression. Among the four known PLCβ isoforms, PLCβ3 (PLCB3) was specifically up-regulated in cells from ovulatory-size follicles, in association with a predominantly cytoplasmic location of PLCB3 in these cells and a significant inositol phosphate response to LH stimulation. Furthermore, RNA interference-mediated PLCB3 down-regulation reduced the ability of LH to induce hallmark differentiation responses of granulosa cells, namely transcriptional up-regulation of prostaglandin-endoperoxide synthase 2 and down-regulation of both aromatase expression and estradiol production. Responses to the AC agonist, forskolin, however, were not affected. In addition, PLCB3 down-regulation did not alter cAMP responses to LH in granulosa cells, ruling out a primary involvement of AC in mediating the effects of PLCB3. In summary, we provide evidence of a physiological involvement of PLCβ signaling in ovulatory-size follicles and specifically identify PLCB3 as a mediator of LH-induced differentiation responses of granulosa cells.
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Affiliation(s)
- Francesc X Donadeu
- Roslin Institute, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, Scotland, United Kingdom.
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Huang W, Hicks SN, Sondek J, Zhang Q. A fluorogenic, small molecule reporter for mammalian phospholipase C isozymes. ACS Chem Biol 2011; 6:223-8. [PMID: 21158426 DOI: 10.1021/cb100308n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Phospholipase C isozymes (PLCs) catalyze the conversion of the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP(2)) into two second messengers, inositol 1,4,5-trisphosphate and diacylglycerol. This family of enzymes are key signaling proteins that regulate the physiological responses of many extracellular stimuli such as hormones, neurotransmitters, and growth factors. Aberrant regulation of PLCs has been implicated in various diseases including cancer and Alzheimer's disease. How, when, and where PLCs are activated under different cellular contexts are still largely unknown. We have developed a fluorogenic PLC reporter, WH-15, that can be cleaved in a cascade reaction to generate fluorescent 6-aminoquinoline. When applied in enzymatic assays with either pure PLCs or cell lysates, this reporter displays more than a 20-fold fluorescence enhancement in response to PLC activity. Under assay conditions, WH-15 has comparable K(m) and V(max) with the endogenous PIP(2). This novel reporter will likely find broad applications that vary from imaging PLC activity in live cells to high-throughput screening of PLC inhibitors.
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Affiliation(s)
- Weigang Huang
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Stephanie N. Hicks
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - John Sondek
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Qisheng Zhang
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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25
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Andrikopoulos P, Fraser SP, Patterson L, Ahmad Z, Burcu H, Ottaviani D, Diss JKJ, Box C, Eccles SA, Djamgoz MBA. Angiogenic functions of voltage-gated Na+ Channels in human endothelial cells: modulation of vascular endothelial growth factor (VEGF) signaling. J Biol Chem 2011; 286:16846-60. [PMID: 21385874 DOI: 10.1074/jbc.m110.187559] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Voltage-gated sodium channel (VGSC) activity has previously been reported in endothelial cells (ECs). However, the exact isoforms of VGSCs present, their mode(s) of action, and potential role(s) in angiogenesis have not been investigated. The main aims of this study were to determine the role of VGSC activity in angiogenic functions and to elucidate the potentially associated signaling mechanisms using human umbilical vein endothelial cells (HUVECs) as a model system. Real-time PCR showed that the primary functional VGSC α- and β-subunit isoforms in HUVECs were Nav1.5, Nav1.7, VGSCβ1, and VGSCβ3. Western blots verified that VGSCα proteins were expressed in HUVECs, and immunohistochemistry revealed VGSCα expression in mouse aortic ECs in vivo. Electrophysiological recordings showed that the channels were functional and suppressed by tetrodotoxin (TTX). VGSC activity modulated the following angiogenic properties of HUVECs: VEGF-induced proliferation or chemotaxis, tubular differentiation, and substrate adhesion. Interestingly, different aspects of angiogenesis were controlled by the different VGSC isoforms based on TTX sensitivity and effects of siRNA-mediated gene silencing. Additionally, we show for the first time that TTX-resistant (TTX-R) VGSCs (Nav1.5) potentiate VEGF-induced ERK1/2 activation through the PKCα-B-RAF signaling axis. We postulate that this potentiation occurs through modulation of VEGF-induced HUVEC depolarization and [Ca(2+)](i). We conclude that VGSCs regulate multiple angiogenic functions and VEGF signaling in HUVECs. Our results imply that targeting VGSC expression/activity could be a novel strategy for controlling angiogenesis.
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Affiliation(s)
- Petros Andrikopoulos
- Division of Cell and Molecular Biology, Neuroscience Solutions to Cancer Research Group, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
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26
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Duffy DM. Prostaglandin dehydrogenase (PGDH) in granulosa cells of primate periovulatory follicles is regulated by the ovulatory gonadotropin surge via multiple G proteins. Mol Cell Endocrinol 2011; 333:119-26. [PMID: 21167905 PMCID: PMC3039104 DOI: 10.1016/j.mce.2010.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 12/06/2010] [Accepted: 12/09/2010] [Indexed: 02/01/2023]
Abstract
The ovulatory gonadotropin surge increases granulosa cell prostaglandin synthesis as well as prostaglandin dehydrogenase (PGDH), the key enzyme responsible for prostaglandin metabolism. To investigate gonadotropin regulation of PGDH in the primate follicle, monkey granulosa cells were obtained across the 40-h periovulatory interval. PGDH activity was low before the ovulatory hCG stimulus, peaked 12-24 h after hCG, and was low again 36 h after hCG administration. Granulosa cells maintained in vitro with hCG showed a similar temporal pattern of PGDH. The LH/CG receptor can utilize multiple signaling pathways to regulate intracellular events. Gonadotropin-stimulated cAMP appears to act primarily via the Epacs to increase PGDH mRNA, protein, and activity. In contrast, PLC activation of PKC likely decreases PGDH mRNA, protein, and activity late in the periovulatory interval. Increased, then decreased PGDH activity may delay accumulation of prostaglandins in the follicle until late in the periovulatory interval, contributing to timely ovulation in primates.
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Affiliation(s)
- Diane M Duffy
- Department of Physiological Sciences, Eastern Virginia Medical School, 700 Olney Road, Lewis Hall, Norfolk, VA 23507, United States.
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Klein RR, Bourdon DM, Costales CL, Wagner CD, White WL, Williams JD, Hicks SN, Sondek J, Thakker DR. Direct activation of human phospholipase C by its well known inhibitor u73122. J Biol Chem 2011; 286:12407-16. [PMID: 21266572 DOI: 10.1074/jbc.m110.191783] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C (PLC) enzymes are an important family of regulatory proteins involved in numerous cellular functions, primarily through hydrolysis of the polar head group from inositol-containing membrane phospholipids. U73122 (1-(6-((17β-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione), one of only a few small molecules reported to inhibit the activity of these enzymes, has been broadly applied as a pharmacological tool to implicate PLCs in diverse experimental phenotypes. The purpose of this study was to develop a better understanding of molecular interactions between U73122 and PLCs. Hence, the effects of U73122 on human PLCβ3 (hPLCβ3) were evaluated in a cell-free micellar system. Surprisingly, U73122 increased the activity of hPLCβ3 in a concentration- and time-dependent manner; up to an 8-fold increase in enzyme activity was observed with an EC50=13.6±5 μm. Activation of hPLCβ3 by U73122 required covalent modification of cysteines as evidenced by the observation that enzyme activation was attenuated by thiol-containing nucleophiles, l-cysteine and glutathione. Mass spectrometric analysis confirmed covalent reaction with U73122 at eight cysteines, although maximum activation was achieved without complete alkylation; the modified residues were identified by LC/MS/MS peptide sequencing. Interestingly, U73122 (10 μm) also activated hPLCγ1 (>10-fold) and hPLCβ2 (∼2-fold); PLCδ1 was neither activated nor inhibited. Therefore, in contrast to its reported inhibitory potential, U73122 failed to inhibit several purified PLCs. Most of these PLCs were directly activated by U73122, and a simple mechanism for the activation is proposed. These results strongly suggest a need to re-evaluate the use of U73122 as a general inhibitor of PLC isozymes.
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Affiliation(s)
- Ryan R Klein
- Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7360, USA
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28
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Activation of the inositol (1,4,5)-triphosphate calcium gate receptor is required for HIV-1 Gag release. J Virol 2010; 84:6438-51. [PMID: 20427533 DOI: 10.1128/jvi.01588-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The structural precursor polyprotein, Gag, encoded by all retroviruses, including the human immunodeficiency virus type 1 (HIV-1), is necessary and sufficient for the assembly and release of particles that morphologically resemble immature virus particles. Previous studies have shown that the addition of Ca(2+) to cells expressing Gag enhances virus particle production. However, no specific cellular factor has been implicated as mediator of Ca(2+) provision. The inositol (1,4,5)-triphosphate receptor (IP3R) gates intracellular Ca(2+) stores. Following activation by binding of its ligand, IP3, it releases Ca(2+) from the stores. We demonstrate here that IP3R function is required for efficient release of HIV-1 virus particles. Depletion of IP3R by small interfering RNA, sequestration of its activating ligand by expression of a mutated fragment of IP3R that binds IP3 with very high affinity, or blocking formation of the ligand by inhibiting phospholipase C-mediated hydrolysis of the precursor, phosphatidylinositol-4,5-biphosphate, inhibited Gag particle release. These disruptions, as well as interference with ligand-receptor interaction using antibody targeted to the ligand-binding site on IP3R, blocked plasma membrane accumulation of Gag. These findings identify IP3R as a new determinant in HIV-1 trafficking during Gag assembly and introduce IP3R-regulated Ca(2+) signaling as a potential novel cofactor in viral particle release.
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Xiong Y, Huo Y, Chen C, Zeng H, Lu X, Wei C, Ruan C, Zhang X, Hu Z, Shibuya M, Luo J. Vascular endothelial growth factor (VEGF) receptor-2 tyrosine 1175 signaling controls VEGF-induced von Willebrand factor release from endothelial cells via phospholipase C-gamma 1- and protein kinase A-dependent pathways. J Biol Chem 2009; 284:23217-24. [PMID: 19570985 DOI: 10.1074/jbc.m109.019679] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
There is increasing evidence that vascular endothelial growth factor (VEGF) contributes to inflammation independent of its angiogenic functions. Targeting some of the components in endothelial Weibel-Palade bodies (WPBs) effectively inhibits VEGF-induced inflammation, but little is known about how VEGF regulates WPB exocytosis. In this study, we showed that VEGF receptor-2 (VEGFR2), but not VEGFR1, is responsible for VEGF-induced release of von Willebrand factor (vWF), a major marker of WPBs. This is in good contrast to VEGF-stimulated interleukin-6 release from endothelium, which is selectively mediated through VEGFR1. We further demonstrated that VEGFR2-initiated phospholipase C-gamma1 (PLCgamma1)/calcium signaling is important but insufficient for full vWF release, suggesting the possible participation of another effector pathway. We found that cAMP/protein kinase A (PKA) signaling is required for full vWF release. Importantly, a single mutation of Tyr(1175) in the C terminus of VEGFR2, a tyrosine residue crucial for embryonic vasculogenesis, abolished vWF release, concomitant with defective activations of both PLCgamma1 and PKA. These data suggest that Tyr(1175) mediates both PLCgamma1-dependent and PKA-dependent signaling pathways. Taken together, our results not only reveal a novel Tyr(1175)-mediated signaling pathway but also highlight a potentially new therapeutic target for the management of vascular inflammation.
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Affiliation(s)
- Yan Xiong
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing 10087, China
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Boggs JM, Gao W, Hirahara Y. Signal transduction pathways involved in interaction of galactosylceramide/sulfatide-containing liposomes with cultured oligodendrocytes and requirement for myelin basic protein and glycosphingolipids. J Neurosci Res 2008; 86:1448-58. [DOI: 10.1002/jnr.21603] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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