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Advantages and shortcomings of cell-based electrical impedance measurements as a GPCR drug discovery tool. Biosens Bioelectron 2019; 137:33-44. [PMID: 31077988 DOI: 10.1016/j.bios.2019.04.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/05/2019] [Accepted: 04/20/2019] [Indexed: 12/13/2022]
Abstract
G Protein-Coupled Receptors (GPCRs) transduce extracellular signals and activate intracellular pathways, usually through activating associated G proteins. Due to their involvement in many human diseases, they are recognized worldwide as valuable drug targets. Many experimental approaches help identify small molecules that target GPCRs, including in vitro cell-based reporter assays and binding studies. Most cell-based assays use one signaling pathway or reporter as an assay readout. Moreover, they often require cell labeling or the integration of reporter systems. Over the last decades, cell-based electrical impedance biosensors have been explored for drug discovery. This label-free method holds many advantages over other cellular assays in GPCR research. The technology requires no cell manipulation and offers real-time kinetic measurements of receptor-mediated cellular changes. Instead of measuring the activity of a single reporter, the impedance readout includes information on multiple signaling events. This is beneficial when screening for ligands targeting orphan GPCRs since the signaling cascade(s) of the majority of these receptors are unknown. Due to its sensitivity, the method also applies to cellular models more relevant to disease, including patient-derived cell cultures. Despite its advantages, remaining issues regarding data comparability and interpretability has limited implementation of cell-based electrical impedance (CEI) in drug discovery. Future optimization must include both full exploitation of CEI response data using various ways of analysis as well as further exploration of its potential to detect biased activities early on in drug discovery. Here, we review the contribution of CEI technology to GPCR research, discuss its comparative benefits, and provide recommendations.
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Riccetti L, Sperduti S, Lazzaretti C, Klett D, De Pascali F, Paradiso E, Limoncella S, Potì F, Tagliavini S, Trenti T, Galano E, Palmese A, Satwekar A, Daolio J, Nicoli A, Villani MT, Aguzzoli L, Reiter E, Simoni M, Casarini L. Glycosylation Pattern and in vitro Bioactivity of Reference Follitropin alfa and Biosimilars. Front Endocrinol (Lausanne) 2019; 10:503. [PMID: 31396162 PMCID: PMC6667556 DOI: 10.3389/fendo.2019.00503] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/11/2019] [Indexed: 12/20/2022] Open
Abstract
Recombinant follicle-stimulating hormone (FSH) (follitropin alfa) and biosimilar preparations are available for clinical use. They have specific FSH activity and a unique glycosylation profile dependent on source cells. The aim of the study is to compare the originator (reference) follitropin alfa (Gonal-f®)- with biosimilar preparations (Bemfola® and Ovaleap®)-induced cellular responses in vitro. Gonadotropin N-glycosylation profiles were analyzed by ELISA lectin assay, revealing preparation specific-patterns of glycan species (Kruskal-Wallis test; p < 0.05, n = 6) and by glycotope mapping. Increasing concentrations of Gonal-f® or biosimilar (1 × 10-3-1 × 103 ng/ml) were used for treating human primary granulosa lutein cells (hGLC) and FSH receptor (FSHR)-transfected HEK293 cells in vitro. Intracellular cAMP production, Ca2+ increase and β-arrestin 2 recruitment were evaluated by BRET, CREB, and ERK1/2 phosphorylation by Western blotting. 12-h gene expression, and 8- and 24-h progesterone and estradiol synthesis were measured by real-time PCR and immunoassay, respectively. We found preparation-specific glycosylation patterns by lectin assay (Kruskal-Wallis test; p < 0.001; n = 6), and similar cAMP production and β-arrestin 2 recruitment in FSHR-transfected HEK293 cells (cAMP EC50 range = 12 ± 0.9-24 ± 1.7 ng/ml; β-arrestin 2 EC50 range = 140 ± 14.1-313 ± 18.7 ng/ml; Kruskal-Wallis test; p ≥ 0.05; n = 4). Kinetics analysis revealed that intracellular Ca2+ increased upon cell treatment by 4 μg/ml Gonal-f®, while equal concentrations of biosimilars failed to induced a response (Kruskal-Wallis test; p < 0.05; n = 3). All preparations induced both 8 and 24 h-progesterone and estradiol synthesis in hGLC, while no different EC50s were demonstrated (Kruskal-Wallis test; p > 0.05; n = 5). Apart from preparation-specific intracellular Ca2+ increases achieved at supra-physiological hormone doses, all compounds induced similar intracellular responses and steroidogenesis, reflecting similar bioactivity, and overall structural homogeneity.
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Affiliation(s)
- Laura Riccetti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Samantha Sperduti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Clara Lazzaretti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Danièle Klett
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | | | - Elia Paradiso
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvia Limoncella
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Francesco Potì
- Unit of Neurosciences, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Simonetta Tagliavini
- Department of Laboratory Medicine and Pathological Anatomy, Azienda USL, NOCSAE, Modena, Italy
| | - Tommaso Trenti
- Department of Laboratory Medicine and Pathological Anatomy, Azienda USL, NOCSAE, Modena, Italy
| | - Eugenio Galano
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Angelo Palmese
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Abhijeet Satwekar
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Jessica Daolio
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Alessia Nicoli
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Maria Teresa Villani
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Lorenzo Aguzzoli
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Eric Reiter
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria, Modena, Italy
| | - Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Livio Casarini
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Bobkov V, Zarca AM, Van Hout A, Arimont M, Doijen J, Bialkowska M, Toffoli E, Klarenbeek A, van der Woning B, van der Vliet HJ, Van Loy T, de Haard H, Schols D, Heukers R, Smit MJ. Nanobody-Fc constructs targeting chemokine receptor CXCR4 potently inhibit signaling and CXCR4-mediated HIV-entry and induce antibody effector functions. Biochem Pharmacol 2018; 158:413-424. [DOI: 10.1016/j.bcp.2018.10.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/14/2022]
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Dupré C, Bruno O, Bonnaud A, Giganti A, Nosjean O, Legros C, Boutin JA. Assessments of cellular melatonin receptor signaling pathways: β-arrestin recruitment, receptor internalization, and impedance variations. Eur J Pharmacol 2017; 818:534-544. [PMID: 29154938 DOI: 10.1016/j.ejphar.2017.11.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/03/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022]
Abstract
Melatonin receptors belong to the family of G-protein coupled receptors. Agonist-induced receptor activation is terminated with the recruitment of β-arrestin, which leads to receptor internalization. Furthermore, agonist binding induces a shift in cellular shape that translates into a change in the electric impedance of the cell. In the present study, we employed engineered cells to study these internalization-related processes in the context of the two melatonin receptors, MT1 and MT2. To assess these three receptor internalization-related functions and validate the results, we employed four classical ligands of melatonin receptors: the natural agonist melatonin; the super-agonist 2-iodo-melatonin and the two antagonists luzindole and 4-phenyl-2-propionamidotetralin. The assessments confirmed the nature of the agonistic ligands but showed that 4-phenyl-2-propionamidotetralin, a described antagonist, is a biased partial agonist at MT2 with poorer affinity for MT1. The methods are now available to be applied to any receptor system for which multiple signaling pathways must be evaluated for new molecules.
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Affiliation(s)
- Clémence Dupré
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Olivier Bruno
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Anne Bonnaud
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Adeline Giganti
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Olivier Nosjean
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Céline Legros
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France
| | - Jean A Boutin
- Pôle d'Expertise Biotechnologie, Chimie, Biologie, Institut de Recherches SERVIER, 125, Chemin De Ronde, 78290 Croissy-sur-Seine, France.
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Abstract
Cellular dielectric spectroscopy (CDS) provides realtime, label-free, universal measurements, enabling comprehensive pharmacological evaluation of cell surface receptors in living cells. The sensitivity of the measurement allows monitoring of ligand-mediated activation of endogenous receptors, therefore generating physiologically relevant data. Activation of receptors results in CDS response profiles that are characteristic of main subsets of G-protein coupled receptors (GPCRs) within a cell line. This allows cluster analysis of response profiles that may be used in several important applications, which include identification of the G-protein coupling of orphan GPCRs and the cataloging of active endogenous receptors in cells. In this study, CDS technology is used in the pharmacological evaluation of multiple receptors in many cell types, including primary cells. Specifically, data is presented demonstrating hit confirmation, receptor selectivity analysis, ligand potency, and Schild analysis of receptor-selective antagonists. CDS results compare favorably to other cell-based assays, and the robustness and reproducibility of CDS assays are reflected by low assay coefficient of variation (CVs) and reliable Z'-scores of the data. Because CDS requires no stable or transiently transfected cells or special reagents, assay development and data acquisition is simple and fast. The ease of use, universality, and label-free nature of the CDS-based platform make it well suited to secondary screening applications in drug discovery.
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Petersen TS, Kristensen SG, Jeppesen JV, Grøndahl ML, Wissing ML, Macklon KT, Andersen CY. Distribution and function of 3',5'-Cyclic-AMP phosphodiesterases in the human ovary. Mol Cell Endocrinol 2015; 403:10-20. [PMID: 25578602 DOI: 10.1016/j.mce.2015.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 01/03/2015] [Accepted: 01/05/2015] [Indexed: 12/29/2022]
Abstract
The concentration of the important second messenger cAMP is regulated by phosphodiesterases (PDEs) and hence an attractive drug target. However, limited human data are available about the PDEs in the ovary. The aim of the present study was to describe and characterise the PDEs in the human ovary. Results were obtained by analysis of mRNA microarray data from follicles and granulosa cells (GCs), combined RT-PCR and enzymatic activity analysis in GCs, immunohistochemical analysis of ovarian sections and by studying the effect of PDE inhibitors on progesterone production from cultured GCs. We found that PDE3, PDE4, PDE7 and PDE8 are the major families present while PDE11A was not detected. PDE8B was differentially expressed during folliculogenesis. In cultured GCs, inhibition of PDE7 and PDE8 increased basal progesterone secretion while PDE4 inhibition increased forskolin-stimulated progesterone secretion. In conclusion, we identified PDE3, PDE4, PDE7 and PDE8 as the major PDEs in the human ovary.
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Affiliation(s)
- T S Petersen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark; Medical Department, LEO Pharma, Ballerup 2750, Denmark.
| | - S G Kristensen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - J V Jeppesen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - M L Grøndahl
- The Fertility Clinic, Herlev Hospital, Copenhagen University Hospital, Copenhagen University, Herlev 2730, Denmark
| | - M L Wissing
- The Fertility Clinic, Holbæk Sygehus, Holbæk 4300, Denmark
| | - K T Macklon
- The Fertility Clinic, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - C Y Andersen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
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Casarini L, Moriondo V, Marino M, Adversi F, Capodanno F, Grisolia C, La Marca A, La Sala GB, Simoni M. FSHR polymorphism p.N680S mediates different responses to FSH in vitro. Mol Cell Endocrinol 2014; 393:83-91. [PMID: 24970684 DOI: 10.1016/j.mce.2014.06.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 02/07/2023]
Abstract
The single nucleotide polymorphism p.N680S of the follicle-stimulating hormone (FSH) receptor (FSHR) is a discrete marker of ovarian response but previous in vitro studies failed to demonstrate differences in the response to FSH between N and S carrier cells. Here we demonstrate that p.N680S mediates different kinetics of the response to FSH in vitro. Intracellular cAMP production is faster in p.N680S N than in S homozygous human granulosa cells (45 versus 90 min to achieve the plateau, respectively; Mann-Whitney's U-test; p < 0.005; n = 4). Reflecting the cAMP kinetics, phospho-ERK1/2 and -CREB activation, AREG and STARD1 gene expressions and progesterone production were qualitatively and quantitatively different in N versus S homozygous cells. Finally, the blockade of ERK pathway by U0126 abolishes the genotype-mediated different effects on gene expression and progesterone production (Mann-Whitney's U-test; p ≥ 0.005; n = 3).
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Affiliation(s)
- Livio Casarini
- Unit of Endocrinology, Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy.
| | - Valeria Moriondo
- Unit of Endocrinology, Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Marino
- Unit of Endocrinology, Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Francesca Adversi
- Unit of Obstetrics and Gynecology, IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Francesco Capodanno
- Unit of Obstetrics and Gynecology, IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Chiarina Grisolia
- Dept. of Laboratory Medicine and Pathology, Laboratory of Chemical-Clinical Analysis, University Hospital of Modena, Modena, Italy
| | - Antonio La Marca
- Dept. of Medical and Mother-Infant and Adult Surgical Sciences, Unit of Obstetrics and Gynecology, University Hospital of Modena, Modena, Italy
| | - Giovanni Battista La Sala
- Unit of Obstetrics and Gynecology, IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Italy; Dept. of Medical and Surgical Sciences for Children and Adults, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Manuela Simoni
- Unit of Endocrinology, Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy; Azienda USL, Modena, Italy
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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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Dickinson RE, Stewart AJ, Myers M, Millar RP, Duncan WC. Differential expression and functional characterization of luteinizing hormone receptor splice variants in human luteal cells: implications for luteolysis. Endocrinology 2009; 150:2873-81. [PMID: 19246536 DOI: 10.1210/en.2008-1382] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The human LH receptor (LHR) plays a key role in luteal function and the establishment of pregnancy through its interaction with the gonadotropins LH and human chorionic gonadotropin. We previously identified four splice variants of the LHR in human luteinized granulosa cells (LGCs) and corpora lutea (CL). Real-time quantitative PCR revealed that expression of the full-length LHR (LHRa) and the most truncated form (LHRd) changed significantly in CL harvested at different stages of the ovarian cycle (P < 0.01, ANOVA). LHRa expression was reduced in the late luteal CL (P < 0.05). Conversely, an increase in LHRd expression was observed in the late luteal CL (P < 0.01). Chronic manipulation of human chorionic gonadotropin in LGC primary cultures supported the in vivo findings. LHRd encodes a protein lacking the transmembrane and carboxyl terminal domains. COS-7 cells expressing LHRd were unable to produce cAMP in response to LH stimulation. COS-7 cells coexpressing LHRd and LHRa also failed to generate cAMP in response to LH, suggesting that this truncated form has a negative effect on the signaling of LHRa. Immunofluorescence staining of LGC and COS-7 cells implied that there is a reduction in cell surface expression of LHRa when LHRd is present. Overall, these results imply expression of LHR splice variants is regulated in the human CL. Furthermore, during functional luteolysis a truncated variant could modulate the cell surface expression and activity of full-length LHR.
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Affiliation(s)
- Rachel E Dickinson
- Department of Reproductive and DevelopmentalSciences, Division of Obstetrics and Gynaecology, Centre for Reproductive Biology,The Queen's Medical Research Institute, Edinburgh, United Kingdom.
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Differing pharmacological activities of thiazolidinone analogs at the FSH receptor. Biochem Biophys Res Commun 2008; 368:723-8. [DOI: 10.1016/j.bbrc.2008.01.119] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 01/26/2008] [Indexed: 11/24/2022]
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Verdonk E, Johnson K, McGuinness R, Leung G, Chen YW, Tang HR, Michelotti JM, Liu VF. Cellular Dielectric Spectroscopy: A Label-Free Comprehensive Platform for Functional Evaluation of Endogenous Receptors. Assay Drug Dev Technol 2006; 4:609-19. [PMID: 17115931 DOI: 10.1089/adt.2006.4.609] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The CellKey (MDS Sciex, South San Francisco, CA) system enables comprehensive pharmacological evaluation of cell surface receptors, including G-protein coupled receptors (GPCRs) and tyrosine kinase receptors, using adherent and suspension cell lines and primary cells. A unique application enabled by the ability of the CellKey system to reliably quantify activation of endogenous receptors is receptor panning. This application allows investigators to easily screen disease-relevant cell types for functionally active target receptors by treating cells with a panel of receptor-specific ligands. Receptor panning of multiple cell types including Chinese hamster ovary, human embryonic kidney 293, HeLa, U-937, U-2 OS, and TE671 cells resulted in the identification of many functionally active, differently coupled endogenous GPCRs, some of which have not been previously documented in the literature. Upon detecting GPCR activation in live cells, unique cellular dielectric spectroscopy (CDS) response profiles are generated within minutes that reflect the signaling pathways utilized and have been shown to be characteristic of Gs, Gq, and Gi GPCRs. The fact that the CDS response profiles are predictive of the G-protein coupling mechanism of the receptor was demonstrated by using examples of subtype-selective agonists/antagonists to identify the subtypes of the endogenous histamine and beta-adrenergic receptors expressed in U-2 OS cells. A direct correlation is shown between receptor subtype G-protein coupling and CDS response profile. In addition, complex pharmacology, including detection of partial agonism and Schild analysis for endogenous receptors, is presented. The CellKey system allows investigators to conduct studies using endogenously expressed receptors to generate data that are physiologically relevant and in disease context.
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Sun L, Peng Y, Sharrow AC, Iqbal J, Zhang Z, Papachristou DJ, Zaidi S, Zhu LL, Yaroslavskiy BB, Zhou H, Zallone A, Sairam MR, Kumar TR, Bo W, Braun J, Cardoso-Landa L, Schaffler MB, Moonga BS, Blair HC, Zaidi M. FSH Directly Regulates Bone Mass. Cell 2006; 125:247-60. [PMID: 16630814 DOI: 10.1016/j.cell.2006.01.051] [Citation(s) in RCA: 490] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 09/02/2005] [Accepted: 01/23/2006] [Indexed: 11/29/2022]
Abstract
Postmenopausal osteoporosis, a global public health problem, has for decades been attributed solely to declining estrogen levels. Although FSH levels rise sharply in parallel, a direct effect of FSH on the skeleton has never been explored. We show that FSH is required for hypogonadal bone loss. Neither FSHbeta nor FSH receptor (FSHR) null mice have bone loss despite severe hypogonadism. Bone mass is increased and osteoclastic resorption is decreased in haploinsufficient FSHbeta+/- mice with normal ovarian function, suggesting that the skeletal action of FSH is estrogen independent. Osteoclasts and their precursors possess G(i2alpha)-coupled FSHRs that activate MEK/Erk, NF-kappaB, and Akt to result in enhanced osteoclast formation and function. We suggest that high circulating FSH causes hypogonadal bone loss.
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Affiliation(s)
- Li Sun
- Mount Sinai Bone Program, Department of Medicine and Department of Orthopedics, Mount Sinai School of Medicine, New York, NY 10029, USA
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Karas K, Brauer P, Petzel D. Actin redistribution in mosquito malpighian tubules after a blood meal and cyclic AMP stimulation. JOURNAL OF INSECT PHYSIOLOGY 2005; 51:1041-54. [PMID: 15993891 DOI: 10.1016/j.jinsphys.2005.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 05/05/2005] [Accepted: 05/05/2005] [Indexed: 05/03/2023]
Abstract
Fluid secretion by mosquito Malpighian tubules is critical to maintaining fluid and electrolyte balance after a blood meal. Endogenous cAMP levels increase in Malpighian tubules after a blood meal. Here, we determined if corresponding changes in intracellular actin distribution occur after a blood meal or dibutyryl-cAMP (db-cAMP) stimulation and whether altering actin turnover inhibits secretion. In untreated Malpighian tubules, beta-actin immunostaining was more intense in the apical region of adult Malpighian tubules than in the cytoplasm. Stimulation by a blood meal or db-cAMP significantly decreased beta-actin immunostaining in the non-apical region of the cell. Db-cAMP had similar effects in larvae and pupae Malpighian tubules. In contrast, no detectable shift in F-actin distribution was detected; however, F-actin bundles within the cytoplasm increased in size after treatment with db-cAMP. Pretreatment of Malpighian tubules with agents perturbing actin fiber assembly and disassembly decreased basal secretion rates and inhibited the stimulatory effects of db-cAMP. Our results show (1) beta-actin redistributes toward the apical membrane after a blood meal and this correlates temporally with increase urine flow rate and intracellular cAMP levels, (2) Malpighian tubules from all developmental stages exhibit this same response to db-cAMP-stimulation, and (3) dynamic assembly and disassembly of beta-actin is required for db-cAMP-stimulated secretion.
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Affiliation(s)
- Katherine Karas
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
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Wang YJ, Gregory RB, Barritt GJ. Regulation of F-actin and endoplasmic reticulum organization by the trimeric G-protein Gi2 in rat hepatocytes. Implication for the activation of store-operated Ca2+ inflow. J Biol Chem 2000; 275:22229-37. [PMID: 10787407 DOI: 10.1074/jbc.m001563200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The roles of the heterotrimeric G-protein, G(i2), in regulating the actin cytoskeleton and the activation of store-operated Ca(2+) channels in rat hepatocytes were investigated. Galpha(i2) was principally associated with the plasma membrane and microsomes. Both F-actin and Galpha(i2) were detected by Western blot analysis in a purified plasma membrane preparation, the supernatant and pellet obtained by treating the plasma membrane with Triton X-100, and after depolymerization and repolymerization of F-actin in the Triton X-100-insoluble pellet. Actin in the Triton X-100-soluble supernatant co-precipitated with Galpha(i2) using either anti-Galpha(i2) or anti-actin antibodies. The principally cortical location of F-actin in hepatocytes cultured for 0.5 h changed to a pericanalicular distribution over a further 3.5 h. Some Galpha(i2) co-localized with F-actin at the plasma membrane. Pretreatment with pertussis toxin ADP-ribosylated 70-80% of Galpha(i2) in the plasma membrane and microsomes, prevented the redistribution of F-actin, caused redistribution and fragmentation of the endoplasmic reticulum, and inhibited vasopressin-stimulated Ca(2+) inflow. It is concluded that (i) a significant portion of hepatocyte Galpha(i2) associates with, and regulates the arrangement of, cortical F-actin and the endoplasmic reticulum and (ii) either or both of these regulatory roles are likely to be required for normal vasopressin activation of Ca(2+) inflow.
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Affiliation(s)
- Y J Wang
- Department of Medical Biochemistry, School of Medicine, Faculty of Health Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
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