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Chruścicka B, Burnat G, Brański P, Chorobik P, Lenda T, Marciniak M, Pilc A. Tetracycline-based system for controlled inducible expression of group III metabotropic glutamate receptors. ACTA ACUST UNITED AC 2014; 20:350-8. [PMID: 25394730 DOI: 10.1177/1087057114559183] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A stable and inducible expression of metabotropic glutamate receptor type 4, 7, and 8 was obtained in T-REx 293 cells using the tetracycline system. Tetracycline administration to the cell medium resulted in rapid induction and time-dependent expression of mGlu receptors, which also correlates with its functionality in a cAMP accumulation assay. The pharmacological properties of recombinant mGlu receptors were verified using orthosteric and allosteric ligands. Data suggest that the Tet-on inducible system is suitable for functional mGlu receptors' expression and characterization by means of the cAMP accumulation assay. It makes this system a precise, reproducible, and large-scale screening method, as well as a reasonable tool to study signaling properties of mGlu receptors.
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Affiliation(s)
- Barbara Chruścicka
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Grzegorz Burnat
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Piotr Brański
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Paulina Chorobik
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Tomasz Lenda
- Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Marcin Marciniak
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland
| | - Andrzej Pilc
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Smętna, Poland Faculty of Health Sciences, Medical College, Jagiellonian University, Kraków, Grzegórzecka, Poland
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Ren J, Li XR, Liu PC, Cai MJ, Liu W, Wang JX, Zhao XF. G-protein αq participates in the steroid hormone 20-hydroxyecdysone nongenomic signal transduction. J Steroid Biochem Mol Biol 2014; 144 Pt B:313-23. [PMID: 25125388 DOI: 10.1016/j.jsbmb.2014.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 08/02/2014] [Accepted: 08/08/2014] [Indexed: 11/22/2022]
Abstract
The nuclear receptor-mediated genomic pathways of the animal steroid hormones are well known. However, the cell membrane receptor-mediated nongenomic pathways of the animal steroid hormones are little understood. In this study, we report the participation of a G-protein alpha q (Gαq)(1) subunit in the 20E nongenomic pathway in the cell membrane and regulating gene expression during molting and metamorphosis in a lepidopteran insect, Helicoverpa armigera. 20E-induced phosphorylation of Gαq was detected using two-dimensional electrophoresis techniques. Knockdown of Gαq by injecting double-stranded RNA suppressed the development of larvae, delayed metamorphosis, and inhibited 20E-induced gene expression. Gαq was distributed throughout the cell, and migrated toward the plasma membrane upon 20E induction. Gαq was necessary in the 20E-induced intracellular Ca(2+) release and extracellular Ca(2+) influx. The protein kinase C (PKC) inhibitor could repress 20E-induced phosphorylation of cyclin-dependent kinase 10 (CDK10) and transcription factor ultraspiracle (USP1). PKC inhibitor could repress the Gαq phosphorylation and membrane trafficking. These results suggest that Gαq participates in 20E signaling in the cell membrane at the pre-genomic stage by modulating the increase of the intracellular Ca(2+) and phosphorylation of CDK10 and USP1 in 20E transcription complex to regulate gene transcription.
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Affiliation(s)
- Jing Ren
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Xiang-Ru Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Peng-Cheng Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Mei-Juan Cai
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Wen Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Jin-Xing Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
| | - Xiao-Fan Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China.
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Wangari-Talbot J, Wall BA, Goydos JS, Chen S. Functional effects of GRM1 suppression in human melanoma cells. Mol Cancer Res 2012; 10:1440-50. [PMID: 22798429 DOI: 10.1158/1541-7786.mcr-12-0158] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ectopic expression of a neuronal receptor, metabotropic glutamate receptor 1 (Grm1), in melanocytes has been implicated in melanoma development in mouse models. The human relevance of this receptor's involvement in melanoma pathogenesis was shown by detecting GRM1 expression in subsets of human melanomas, an observation lacking in benign nevi or normal melanocytes. Grm1-transformed mouse melanocytes and a conditional Grm1 transgenic mouse model confirmed a requirement for sustained expression of Grm1 for the maintenance of transformed phenotypes in vitro and tumorigenicity in vivo. Here, we investigate if continued GRM1 expression is also required in human melanoma cell lines by using two inducible, silencing RNA systems: the ecdysone/Ponasterone A and tetracycline on/off approaches to regulate GRM1 expression in the presence of each inducer. Various in vitro assays were conducted to assess the consequences of a reduction in GRM1 expression on cell proliferation, apoptosis, downstream targeted signaling pathways, and in vivo tumorigenesis. We showed that suppression of GRM1 expression in several human melanoma cell lines resulted in a reduction in the number of viable cells and a decrease in stimulated mitogen-activated protein kinase (MAPK) and PI3K/AKT and suppressed tumor progression in vivo. These results reinforce earlier observations where a reduction in cell growth in vitro and tumorigenesis in vivo were correlated with decreased GRM1 activities by pharmacologic inhibitors of the receptor, supporting the notion that GRM1 plays a role in the maintenance of transformed phenotypes in human melanoma cells in vitro and in vivo and could be a potential therapeutic target for the treatment of melanoma.
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Affiliation(s)
- Janet Wangari-Talbot
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, USA
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Inducible expression of G protein-coupled receptors in transfected cells. Methods Mol Biol 2011. [PMID: 21607849 DOI: 10.1007/978-1-61779-126-0_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Biochemical or pharmacological studies of G protein-coupled receptors (GPCRs) are widely conducted in transfected mammalian cells. A variety of commercially available systems allow the generation of stable cell-lines in which expression of the recombinant receptor can be induced on addition of a defined chemical to the culture medium, which operates as a control switch for the transcription of the cloned sequence. Such systems offer the possibility to induce graded levels of receptor expression in the experimental model, or to induce an abrupt downregulation of receptor expression during the maintenance of the cell-line. This chapter provides an overview of the different systems available and provides methods for the generation and validation of stably transfected cell-lines expressing the GPCR of choice.
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Cahlíková L, Macáková K, Chlebek J, Hošt'álková A, Kulhánková A, Opletal L. Ecdysterone and its Activity on some Degenerative Diseases. Nat Prod Commun 2011. [DOI: 10.1177/1934578x1100600527] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Beside ecdysone (1), ecdysterone (2) is one of the most common 5β-cholest-7-en-6-one (ecdysteroid) derivatives, which, besides having a hormonal effect on invertebrates, possesses a number of favorable non-hormonal biological effects on mammals. The most interesting of these is that on degenerative diseases, one of which, up to now not clarified in detail, is the so-called adaptogenic effect (protection of the organism against adverse stress factors) associated with anabolic, gastroprotective, and antioxidant effects. A second group of favorable effects is the possibility of suppression of neurodegenerative processes and protection of the cardiovascular system (metabolic syndrome symptom suppression, antidiabetic activity, and protection of heart and blood vessels). Because of these properties, ecdysterone has the potential to be developed as a medicinal agent.
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Affiliation(s)
- Lucie Cahlíková
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Kateřina Macáková
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Jakub Chlebek
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Anna Hošt'álková
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Andrea Kulhánková
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Lubomír Opletal
- Department of Pharmaceutical Botany and Ecology, ADINACO Research Group, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
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Saeki S, Kunitomo H, Narita Y, Mimura H, Nishi T, Sasaki K. A reporter assay for G-protein-coupled receptors using a B-cell line suitable for stable episomal expression. Anal Biochem 2010; 400:163-72. [PMID: 20122890 DOI: 10.1016/j.ab.2010.01.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 12/03/2009] [Accepted: 01/26/2010] [Indexed: 01/22/2023]
Abstract
We have established a cAMP response element (CRE)-mediated reporter assay system for G-protein-coupled receptors (GPCRs) using an oriP-based estrogen-inducible expression vector and the B-cell line (GBC53 or GBCC71) that expresses EBNA-1 and is adapted to serum-free culture. GBC53 harbors a GAL4-ER expression unit and a CRE-luciferase gene in the genome, and GBCC71 also harbors expression units for two chimeric Galphas proteins (Gs/q and Gs/i). Introduction of a GPCR expression plasmid into GBC53 or GBCC71 creates polyclonal stable transformants in 2 weeks, and these are easily expanded and used for assays after induction of the GPCR expression. Using GBC53, we detected ligand-dependent signals of Gs-coupled GPCRs such as glucagon-like peptide 1 receptor (GLP1R) and beta2 adrenergic receptor (beta2AR) with high sensitivity. Interestingly, we also detected constitutive activity of beta2AR. Using GBCC71, we detected ligand-dependent signals of Gq- or Gi-coupled GPCRs such as H1 histamine receptor and CXCR1 chemokine receptor in addition to Gs-coupled GPCRs. An agonist, antagonist, or inverse agonist was successfully evaluated in this system. We succeeded in constructing a 384-well high-throughput screening (HTS) system for GLP1R. This system enabled us to easily and rapidly make a large number of efficient GPCR assay systems suitable for HTS as well as ligand hunting of orphan GPCRs.
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MESH Headings
- B-Lymphocytes/metabolism
- Cell Line, Tumor
- Cyclic AMP Response Element-Binding Protein/genetics
- Cyclic AMP Response Element-Binding Protein/metabolism
- Gene Expression
- Genes, Reporter
- Glucagon-Like Peptide-1 Receptor
- High-Throughput Screening Assays
- Humans
- Ligands
- Luciferases/genetics
- Luciferases/metabolism
- Plasmids
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Glucagon/genetics
- Receptors, Glucagon/metabolism
- Receptors, Histamine H1/genetics
- Receptors, Histamine H1/metabolism
- Receptors, Interleukin-8A/genetics
- Receptors, Interleukin-8A/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
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Affiliation(s)
- Satoshi Saeki
- Drug Discovery Research Laboratories, Research Division, Kyowa Hakko Kirin, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8731, Japan
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Kurko D, Bekes Z, Gere A, Baki A, Boros A, Kolok S, Bugovics G, Nagy J, Szombathelyi Z, Ignácz-Szendrei G. Comparative pharmacology of adrenergic alpha(2C) receptors coupled to Ca(2+) signaling through different Galpha proteins. Neurochem Int 2009; 55:467-75. [PMID: 19426776 DOI: 10.1016/j.neuint.2009.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 04/24/2009] [Accepted: 04/28/2009] [Indexed: 10/20/2022]
Abstract
Adrenergic alpha(1), alpha(2) and beta receptors are members of the G-protein-coupled receptor families (GPCRs) mediating physiological responses to adrenaline (epinephrine) and noradrenaline (norepinephrine). Since GPCRs are major targets for potential therapeutic agents, development of robust, reliable and cost effective functional screening methods for these receptors is in the focus of pharmacological research. For this reason, the aim of the present study was to develop an intracellular calcium assay for investigating the pharmacology of the alpha(2C) type of adrenergic receptors (alpha(2C)-AR). Although activation of alpha(2C)-AR is not linked to calcium mobilization, co-expression of these receptors with the chimeric Galpha(qi5) protein, containing the five carboxyl-terminal amino acids from G(i), or promiscuosus Galpha(16) protein can divert receptor signaling to the G(q) pathway generating Ca(2+) release from intracellular stores. In order to assess the functional potency of alpha(2)-AR agonists and antagonists, we established a fluorometric Ca(2+) assay using cell lines stably and constitutively co-expressing alpha(2C)-AR and Galpha(qi5) or Galpha(16) proteins (Galpha(qi5)/alpha(2C) and Galpha(16)/alpha(2C)). As part of the pharmacological characterization, we measured the changes in cytoplasmic Ca(2+) levels due to activation of the chimeric Galpha(qi5) or Galpha(16) coupled recombinant alpha(2C) receptors as a function of increasing concentration of several agonists (noradrenaline, brimonidine, oxymetazoline, clonidine, moxonidine) and antagonists (MK912, yohimbine). The binding affinities of alpha(2)-AR agonist and antagonists and the inhibition of the forskolin-stimulated cAMP accumulation in alpha(2C)-AR expressing cells were also measured. These results confirmed that the Galpha(qi5)/alpha(2C) and Galpha(16)/alpha(2C) recombinant systems can be useful for modelling the native G(i)-coupled system. Our results indicate that a plate-reader based fluorometric Ca(2+) assay may be suitable in high-throughput screening for alpha(2C)-AR ligands as well.
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Affiliation(s)
- Dalma Kurko
- Pharmacological and Drug Safety Research, Budapest, Hungary.
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Identification of single nucleotide polymorphisms of the human metabotropic glutamate receptor 1 gene and pharmacological characterization of a P993S variant. Biochem Pharmacol 2008; 77:1246-53. [PMID: 19146831 DOI: 10.1016/j.bcp.2008.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 12/10/2008] [Accepted: 12/11/2008] [Indexed: 11/23/2022]
Abstract
mGluR1 receptors are believed to play major roles in the pathophysiology of diseases such as anxiety and chronic pain and are being actively investigated as targets for drug development. Sequence polymorphisms can potentially influence the efficacy of drugs in patient populations and are therefore an important consideration in the drug development process. To identify DNA sequence variants of the mGluR1 receptor, comparative DNA sequencing was performed on DNA samples (n=186) from apparently healthy subjects representing two ethnic groups. In total, eight non-synonymous single nucleotide polymorphisms (SNPs) were identified and one SNP (c2977>T) was found to be particularly common, this SNP results in a proline to serine substitution at residue 993 (P993S). The WT (P993) and S993 variants were expressed in an inducible system which allowed us to titrate gene expression to equivalent levels and were pharmacologically characterized. We determined the potency and affinity of standard antagonist compounds as well as the potency and efficacy of the endogenous ligand glutamate and other agonist compounds at both receptor variants. Agonist evoked increases in intracellular Ca(2+) were measured by fluorometric imaging plate reader (FLIPR). The potency of mGluR1 antagonists was evaluated by their ability to inhibit quisqualate induced increases in intracellular Ca(2+), while their affinities were determined by radio-ligand binding studies. This study demonstrates that the Pro993Ser amino acid exchange is highly frequent in the human mGluR1 gene. This polymorphism however, does not appear to affect the potency of agonist compounds or the potencies or affinities of small molecule antagonist compounds.
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Salisbury BG, Mukhopadhyay G, Kostich M, Laz TM, Norris ED. Inducible expression and pharmacological characterization of the mouse metabotropic glutamate 5b receptor. Eur J Pharmacol 2008; 579:34-9. [PMID: 17967450 DOI: 10.1016/j.ejphar.2007.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 08/28/2007] [Accepted: 10/05/2007] [Indexed: 11/18/2022]
Abstract
The metabotropic glutamate receptor subtype 5 (mGlu5) and glutamatergic neurotransmission are associated with the pathophysiology of disorders such as anxiety, depression or chronic pain. Human and rat mGlu5 receptors have been cloned and characterized previously. We now describe the cloning of the mouse mGlu5b receptor gene from adult mouse brain and its expression using an ecdysone-inducible system. This subtype has an extra 96 bp sequence which is inserted to the cytoplasmic tail and is identical to the insert present in human and rat mGlu5b. Mouse mGlu5b receptor expression was induced in HEK-293EcR cells by incubation with ponasterone A, an analogue of the insect hormone ecdysone. A fluorometric calcium transient assay system was used to characterize the basic pharmacologic profile of an isolated stable cell line. Quisqualic acid was the most potent receptor agonist (EC(50) approximately 7 nM) although the cells also responded to l-glutamic acid and the Group I-selective receptor agonist, 3,5-dihydroxyphenylglycine (3,5-DHPG). The calcium transients stimulated by these agonists were potently inhibited by reference allosteric mGlu5 antagonists - 2-methyl-6-(phenylethynyl)pyridine (MPEP), 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) and 3-methoxy-5-(pyridine-2-ylethynyl)pyridine (methoxy-PEPy) (IC(50) ranges: 0.8-66 nM). The availability of this mouse mGlu5b receptor-expressing cell line will facilitate in vitro characterization of mGlu5 receptor-selective agonists or antagonists prior to in vivo pharmacologic testing.
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Affiliation(s)
- Brian G Salisbury
- Neurobiology Research and Discovery Technologies, Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
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