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Zhang X, Zhang X, Shi Y, Zhang Z, Wang J, Ru S, Tian H. Interacting with luteinizing hormone receptor provides a new elucidation of the mechanism of anti-androgenicity of bisphenol S. CHEMOSPHERE 2024; 350:141056. [PMID: 38158086 DOI: 10.1016/j.chemosphere.2023.141056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/25/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Bisphenol S (BPS) exhibited inhibitory effects on androgen synthesis, but its target of action remains unclear. We investigated the effects of BPS exposure at environmentally relevant concentrations (1 μg/L, 10 μg/L and 100 μg/L) for 48 h on androgen synthesis in rat ovarian theca cells and explored the underlying mechanisms, target site and target molecule. The results showed that BPS exposure inhibited the transcript levels of steroidogenic genes and reduced the contents of androgen precursors, testosterone and dihydrotestosterone. BPS exposure decreased the phosphorylation levels of extracellular signal-related kinase 1/2 (ERK1/2), and the inhibitory effects of BPS on testosterone content and steroidogenic gene expression were blocked by ERK1/2 agonist LY2828360, suggesting that ERK1/2 signaling pathway mediates the inhibitory effects of BPS on androgen synthesis. BPS mainly accumulated on the cell membrane, impermeable BPS-bovine serum albumin exposure still inhibited androgen synthesis, BPS interacted with rat luteinizing hormone receptor (LHR) via formation of hydrogen bonds in the transmembrane region, and the inhibitory effects of BPS on ERK1/2 phosphorylation were blocked by luteinizing hormone (the natural agonist of LHR), indicating that LHR located on the cell membrane is the target of action of BPS. This paper provides a new elucidation of the mechanism of anti-androgenicity of BPS, especially for the non-genomic pathways.
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Affiliation(s)
- Xinda Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Xiaorong Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yijiao Shi
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Zhenzhong Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Jun Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shaoguo Ru
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Hua Tian
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
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2
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Lazzaretti C, Simoni M, Casarini L, Paradiso E. Allosteric modulation of gonadotropin receptors. Front Endocrinol (Lausanne) 2023; 14:1179079. [PMID: 37305033 PMCID: PMC10248450 DOI: 10.3389/fendo.2023.1179079] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/12/2023] [Indexed: 06/13/2023] Open
Abstract
Gonadotropins regulate reproductive functions by binding to G protein-coupled receptors (FSHR and LHCGR) expressed in the gonads. They activate multiple, cell-specific signalling pathways, consisting of ligand-dependent intracellular events. Signalling cascades may be modulated by synthetic compounds which bind allosteric sites of FSHR and LHCGR or by membrane receptor interactions. Despite the hormone binding to the orthosteric site, allosteric ligands, and receptor heteromerizations may reshape intracellular signalling pattern. These molecules act as positive, negative, or neutral allosteric modulators, as well as non-competitive or inverse agonist ligands, providing a set of new compounds of a different nature and with unique pharmacological characteristics. Gonadotropin receptor allosteric modulation is gathering increasing interest from the scientific community and may be potentially exploited for clinical purposes. This review summarizes the current knowledge on gonadotropin receptor allosteric modulation and their potential, clinical use.
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Affiliation(s)
- Clara Lazzaretti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Baggiovara Hospital, University of Modena and Reggio Emilia, Modena, Italy
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Baggiovara Hospital, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- Department of Medical Specialties, Azienda Ospedaliero-Universitaria di Modena, Baggiovara Hospital, Modena, Italy
| | - Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Baggiovara Hospital, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Elia Paradiso
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Baggiovara Hospital, University of Modena and Reggio Emilia, Modena, Italy
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3
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Shpakov AO. Allosteric Regulation of G-Protein-Coupled Receptors: From Diversity of Molecular Mechanisms to Multiple Allosteric Sites and Their Ligands. Int J Mol Sci 2023; 24:6187. [PMID: 37047169 PMCID: PMC10094638 DOI: 10.3390/ijms24076187] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Allosteric regulation is critical for the functioning of G protein-coupled receptors (GPCRs) and their signaling pathways. Endogenous allosteric regulators of GPCRs are simple ions, various biomolecules, and protein components of GPCR signaling (G proteins and β-arrestins). The stability and functional activity of GPCR complexes is also due to multicenter allosteric interactions between protomers. The complexity of allosteric effects caused by numerous regulators differing in structure, availability, and mechanisms of action predetermines the multiplicity and different topology of allosteric sites in GPCRs. These sites can be localized in extracellular loops; inside the transmembrane tunnel and in its upper and lower vestibules; in cytoplasmic loops; and on the outer, membrane-contacting surface of the transmembrane domain. They are involved in the regulation of basal and orthosteric agonist-stimulated receptor activity, biased agonism, GPCR-complex formation, and endocytosis. They are targets for a large number of synthetic allosteric regulators and modulators, including those constructed using molecular docking. The review is devoted to the principles and mechanisms of GPCRs allosteric regulation, the multiplicity of allosteric sites and their topology, and the endogenous and synthetic allosteric regulators, including autoantibodies and pepducins. The allosteric regulation of chemokine receptors, proteinase-activated receptors, thyroid-stimulating and luteinizing hormone receptors, and beta-adrenergic receptors are described in more detail.
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Affiliation(s)
- Alexander O Shpakov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
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4
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Hanyroup S, Anderson RC, Nataraja S, Yu HN, Millar RP, Newton CL. Rescue of Cell Surface Expression and Signaling of Mutant Follicle-Stimulating Hormone Receptors. Endocrinology 2021; 162:6311857. [PMID: 34192304 DOI: 10.1210/endocr/bqab134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Indexed: 11/19/2022]
Abstract
Mutations in G protein-coupled receptors (GPCRs) underlie numerous diseases. Many cause receptor misfolding and failure to reach the cell surface. Pharmacological chaperones are cell-permeant small molecules that engage nascent mutant GPCRs in the endoplasmic reticulum, stabilizing folding and "rescuing" cell surface expression. We previously demonstrated rescue of cell surface expression of luteinizing hormone receptor mutants by an allosteric agonist. Here we demonstrate that a similar approach can be employed to rescue mutant follicle-stimulating hormone receptors (FSHRs) with poor cell surface expression using a small-molecule FSHR agonist, CAN1404. Seventeen FSHR mutations described in patients with reproductive dysfunction were expressed in HEK 293T cells, and cell surface expression was determined by enzyme-linked immunosorbent assay of epitope-tagged FSHRs before/after treatment with CAN1404. Cell surface expression was severely reduced to ≤18% of wild-type (WT) for 11, modestly reduced to 66% to 84% of WT for 4, and not reduced for 2. Of the 11 with severely reduced cell surface expression, restoration to ≥57% of WT levels was achieved for 6 by treatment with 1 µM CAN1404 for 24 h, and a corresponding increase in FSH-induced signaling was observed for 4 of these, indicating restored functionality. Therefore, CAN1404 acts as a pharmacological chaperone and can rescue cell surface expression and function of certain mutant FSHRs with severely reduced cell surface expression. These findings aid in advancing the understanding of the effects of genetic mutations on GPCR function and provide a proof of therapeutic principle for FSHR pharmacological chaperones.
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Affiliation(s)
- Sharika Hanyroup
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ross C Anderson
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | | | | | - Robert P Millar
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- School of Medicine, Medical and Biological Sciences Building, University of St Andrews, St Andrews, UK
| | - Claire L Newton
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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5
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Roy N, Mascolo E, Lazzaretti C, Paradiso E, D’Alessandro S, Zaręba K, Simoni M, Casarini L. Endocrine Disruption of the Follicle-Stimulating Hormone Receptor Signaling During the Human Antral Follicle Growth. Front Endocrinol (Lausanne) 2021; 12:791763. [PMID: 34956099 PMCID: PMC8692709 DOI: 10.3389/fendo.2021.791763] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/23/2021] [Indexed: 12/21/2022] Open
Abstract
An increasing number of pollutants with endocrine disrupting potential are accumulating in the environment, increasing the exposure risk for humans. Several of them are known or suspected to interfere with endocrine signals, impairing reproductive functions. Follicle-stimulating hormone (FSH) is a glycoprotein playing an essential role in supporting antral follicle maturation and may be a target of disrupting chemicals (EDs) likely impacting female fertility. EDs may interfere with FSH-mediated signals at different levels, since they may modulate the mRNA or protein levels of both the hormone and its receptor (FSHR), perturb the functioning of partner membrane molecules, modify intracellular signal transduction pathways and gene expression. In vitro studies and animal models provided results helpful to understand ED modes of action and suggest that they could effectively play a role as molecules interfering with the female reproductive system. However, most of these data are potentially subjected to experimental limitations and need to be confirmed by long-term observations in human.
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Affiliation(s)
- Neena Roy
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisa Mascolo
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
| | - Clara Lazzaretti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Modena, Italy
| | - Elia Paradiso
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Modena, Italy
| | - Sara D’Alessandro
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Modena, Italy
| | - Kornelia Zaręba
- First Department of Obstetrics and Gynecology, Center of Postgraduate Medical Education, Warsaw, Poland
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria di Modena, Modena, Italy
| | - Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Ospedale Civile Sant’Agostino-Estense, 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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6
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Comparative Study of the Steroidogenic Effects of Human Chorionic Gonadotropin and Thieno[2,3-D]pyrimidine-Based Allosteric Agonist of Luteinizing Hormone Receptor in Young Adult, Aging and Diabetic Male Rats. Int J Mol Sci 2020; 21:ijms21207493. [PMID: 33050653 PMCID: PMC7590010 DOI: 10.3390/ijms21207493] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 12/16/2022] Open
Abstract
Low-molecular-weight agonists of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor (LHCGR), which interact with LHCGR transmembrane allosteric site and, in comparison with gonadotropins, more selectively activate intracellular effectors, are currently being developed. Meanwhile, their effects on testicular steroidogenesis have not been studied. The purpose of this work is to perform a comparative study of the effects of 5-amino-N-tert-butyl-4-(3-(1-methylpyrazole-4-carboxamido)phenyl)-2-(methylthio)thieno[2,3-d] pyrimidine-6-carboxamide (TP4/2), a LHCGR allosteric agonist developed by us, and hCG on adenylyl cyclase activity in rat testicular membranes, testosterone levels, testicular steroidogenesis and spermatogenesis in young (four-month-old), aging (18-month-old) and diabetic male Wistar rats. Type 1 diabetes was caused by a single streptozotocin (50 mg/kg) injection. TP4/2 (20 mg/kg/day) and hCG (20 IU/rat/day) were administered for 5 days. TP4/2 was less effective in adenylyl cyclase stimulation and ability to activate steroidogenesis when administered once into rats. On the 3rd–5th day, TP4/2 and hCG steroidogenic effects in young adult, aging and diabetic rats were comparable. Unlike hCG, TP4/2 did not inhibit LHCGR gene expression and did not hyperstimulate the testicular steroidogenesis system, moderately increasing steroidogenic proteins gene expression and testosterone production. In aging and diabetic testes, TP4/2 improved spermatogenesis. Thus, during five-day administration, TP4/2 steadily stimulates testicular steroidogenesis, and can be used to prevent androgen deficiency in aging and diabetes.
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7
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Wortmann L, Lindenthal B, Muhn P, Walter A, Nubbemeyer R, Heldmann D, Sobek L, Morandi F, Schrey AK, Moosmayer D, Günther J, Kuhnke J, Koppitz M, Lücking U, Röhn U, Schäfer M, Nowak-Reppel K, Kühne R, Weinmann H, Langer G. Discovery of BAY-298 and BAY-899: Tetrahydro-1,6-naphthyridine-Based, Potent, and Selective Antagonists of the Luteinizing Hormone Receptor Which Reduce Sex Hormone Levels in Vivo. J Med Chem 2019; 62:10321-10341. [PMID: 31670515 DOI: 10.1021/acs.jmedchem.9b01382] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The human luteinizing hormone receptor (hLH-R) is a member of the glycoprotein hormone family of G-protein-coupled receptors (GPCRs), activated by luteinizing hormone (hLH) and essentially involved in the regulation of sex hormone production. Thus, hLH-R represents a valid target for the treatment of sex hormone-dependent cancers and diseases (polycystic ovary syndrome, uterine fibroids, endometriosis) as well as contraception. Screening of the Bayer compound library led to the discovery of tetrahydrothienopyridine derivatives as novel, small-molecule (SMOL) hLH-R inhibitors and to the development of BAY-298, the first nanomolar hLH-R antagonist reducing sex hormone levels in vivo. Further optimization of physicochemical, pharmacokinetic, and safety parameters led to the identification of BAY-899 with an improved in vitro profile and proven efficacy in vivo. BAY-298 and BAY-899 serve as valuable tool compounds to study hLH-R signaling in vitro and to interfere with the production of sex hormones in vivo.
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Affiliation(s)
- Lars Wortmann
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | | | - Peter Muhn
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Alexander Walter
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | | | - Dieter Heldmann
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Lothar Sobek
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Federica Morandi
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP) , Robert-Rössle Strasse 10 , Campus Berlin-Buch, 13125 Berlin , Germany
| | - Anna K Schrey
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP) , Robert-Rössle Strasse 10 , Campus Berlin-Buch, 13125 Berlin , Germany
| | - Dieter Moosmayer
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Judith Günther
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Joachim Kuhnke
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Marcus Koppitz
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Ulrich Lücking
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Ulrike Röhn
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Martina Schäfer
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | | | - Ronald Kühne
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP) , Robert-Rössle Strasse 10 , Campus Berlin-Buch, 13125 Berlin , Germany
| | - Hilmar Weinmann
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
| | - Gernot Langer
- Bayer AG, Research & Development, Pharmaceuticals , 13353 Berlin , Germany
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8
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Landomiel F, De Pascali F, Raynaud P, Jean-Alphonse F, Yvinec R, Pellissier LP, Bozon V, Bruneau G, Crépieux P, Poupon A, Reiter E. Biased Signaling and Allosteric Modulation at the FSHR. Front Endocrinol (Lausanne) 2019; 10:148. [PMID: 30930853 PMCID: PMC6425863 DOI: 10.3389/fendo.2019.00148] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/19/2019] [Indexed: 12/12/2022] Open
Abstract
Knowledge on G protein-coupled receptor (GPCRs) structure and mechanism of activation has profoundly evolved over the past years. The way drugs targeting this family of receptors are discovered and used has also changed. Ligands appear to bind a growing number of GPCRs in a competitive or allosteric manner to elicit balanced signaling or biased signaling (i.e., differential efficacy in activating or inhibiting selective signaling pathway(s) compared to the reference ligand). These novel concepts and developments transform our understanding of the follicle-stimulating hormone (FSH) receptor (FSHR) biology and the way it could be pharmacologically modulated in the future. The FSHR is expressed in somatic cells of the gonads and plays a major role in reproduction. When compared to classical GPCRs, the FSHR exhibits intrinsic peculiarities, such as a very large NH2-terminal extracellular domain that binds a naturally heterogeneous, large heterodimeric glycoprotein, namely FSH. Once activated, the FSHR couples to Gαs and, in some instances, to other Gα subunits. G protein-coupled receptor kinases and β-arrestins are also recruited to this receptor and account for its desensitization, trafficking, and intracellular signaling. Different classes of pharmacological tools capable of biasing FSHR signaling have been reported and open promising prospects both in basic research and for therapeutic applications. Here we provide an updated review of the most salient peculiarities of FSHR signaling and its selective modulation.
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9
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Anderson RC, Newton CL, Anderson RA, Millar RP. Gonadotropins and Their Analogs: Current and Potential Clinical Applications. Endocr Rev 2018; 39:911-937. [PMID: 29982442 DOI: 10.1210/er.2018-00052] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/25/2018] [Indexed: 12/15/2022]
Abstract
The gonadotropin receptors LH receptor and FSH receptor play a central role in governing reproductive competency/fertility. Gonadotropin hormone analogs have been used clinically for decades in assisted reproductive therapies and in the treatment of various infertility disorders. Though these treatments are effective, the clinical protocols demand multiple injections, and the hormone preparations can lack uniformity and stability. The past two decades have seen a drive to develop chimeric and modified peptide analogs with more desirable pharmacokinetic profiles, with some displaying clinical efficacy, such as corifollitropin alfa, which is now in clinical use. More recently, low-molecular-weight, orally active molecules with activity at gonadotropin receptors have been developed. Some have excellent characteristics in animals and in human studies but have not reached the market-largely as a result of acquisitions by large pharma. Nonetheless, such molecules have the potential to mitigate risks currently associated with gonadotropin-based fertility treatments, such as ovarian hyperstimulation syndrome and the demands of injection-based therapies. There is also scope for novel use beyond the current remit of gonadotropin analogs in fertility treatments, including application as novel contraceptives; in the treatment of polycystic ovary syndrome; in the restoration of function to inactivating mutations of gonadotropin receptors; in the treatment of ovarian and prostate cancers; and in the prevention of bone loss and weight gain in postmenopausal women. Here we review the properties and clinical application of current gonadotropin preparations and their analogs, as well as the development of novel orally active, small-molecule nonpeptide analogs.
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Affiliation(s)
- Ross C Anderson
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Claire L Newton
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Robert P Millar
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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10
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Nataraja S, Sriraman V, Palmer S. Allosteric Regulation of the Follicle-Stimulating Hormone Receptor. Endocrinology 2018; 159:2704-2716. [PMID: 29800292 DOI: 10.1210/en.2018-00317] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 05/16/2018] [Indexed: 01/08/2023]
Abstract
Follicle-stimulating hormone receptor (FSHR) belongs to the leucine-rich repeat family of the G protein-coupled receptor (LGR), which includes the glycoprotein hormone receptors luteinizing hormone receptor, thyrotropin receptor, and other LGRs 4, 5, 6, and 7. FSH is the key regulator of folliculogenesis in females and spermatogenesis in males. FSH elicits its physiological response through its cognate receptor on the cell surface. Binding of the hormone FSH to its receptor FSHR brings about conformational changes in the receptor that are transduced through the transmembrane domain to the intracellular region, where the downstream effector interaction takes place, leading to activation of the downstream signaling cascade. Identification of small molecules that could activate or antagonize FSHR provided interesting tools to study the signal transduction mechanism of the receptor. However, because of the nature of the ligand-receptor interaction of FSH-FSHR, which contains multiple sites in the extracellular binding domain, most of the small-molecule modulators of FSHR are unable to bind to the orthosteric site of the receptors. Rather they modulate receptor activation through allosteric sites in the transmembrane region. This review will discuss allosteric modulation of FSHR primarily through the discovery of small-molecule modulators, focusing on current data on the status of development and the utility of these as tools to better understand signaling mechanisms.
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11
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Anderson RC, Newton CL, Millar RP. Small Molecule Follicle-Stimulating Hormone Receptor Agonists and Antagonists. Front Endocrinol (Lausanne) 2018; 9:757. [PMID: 30728807 PMCID: PMC6352558 DOI: 10.3389/fendo.2018.00757] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/29/2018] [Indexed: 12/19/2022] Open
Abstract
The follicle-stimulating hormone receptor (FSHR) has been targeted therapeutically for decades, due to its pivotal role in reproduction. To date, only purified and recombinant/biosimilar FSH have been used to target FSHR in assisted reproduction, with the exception of corifollitropin alfa; a modified gonadotropin in which the FSH beta subunit is joined to the C-terminal peptide of the human choriogonadotropin beta subunit, to extend serum half-life. Assisted reproduction protocols usually entail the trauma of multiple injections of FSH to initiate and promote folliculogenesis, which has prompted the development of a number of orally-available low molecular weight (LMW) chemical scaffolds targeting the FSHR. Furthermore, the recently documented roles of the FSHR in diverse extragonadal tissues, including cancer, fat metabolism, and bone density regulation, has highlighted the potential utility of LMW modulators of FSHR activity. Despite these chemical scaffolds encompassing a spectrum of in vitro and in vivo activities and pharmacological profiles, none have yet reached the clinic. In this review we discuss the major chemical classes of LMW molecules targeting the FSHR, and document their activity profiles and current status of development, in addition to discussing potential clinical applications.
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Affiliation(s)
- Ross C. Anderson
- Centre for Neuroendocrinology, Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- *Correspondence: Ross C. Anderson
| | - Claire L. Newton
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Robert P. Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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12
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Abstract
The gonadotropin receptors (luteinising hormone receptor; LHR and follicle-stimulating hormone receptor; FSHR) are G protein-coupled receptors (GPCRs) that play an important role in the endocrine control of reproduction. Thus genetic mutations that cause impaired function of these receptors have been implicated in a number of reproductive disorders. Disease-causing genetic mutations in GPCRs frequently result in intracellular retention and degradation of the nascent protein through misfolding and subsequent recognition by cellular quality control machinery. The discovery and development of novel compounds termed pharmacological chaperones (pharmacoperones) that can stabilise misfolded receptors and restore trafficking and plasma membrane expression are therefore of great interest clinically, and promising in vitro data describing the pharmacoperone rescue of a number of intracellularly retained mutant GPCRs has provided a platform for taking these compounds into in vivo trials. Thienopyrimidine small molecule allosteric gonadotropin receptor agonists (Org 42599 and Org 41841) have been demonstrated to have pharmacoperone activity. These compounds can rescue cell surface expression and in many cases, hormone responsiveness, of a range of retained mutant gonadotropin receptors. Should gonadotropin receptor selectivity of these compounds be improved, they could offer therapeutic benefit to subsets of patients suffering from reproductive disorders attributed to defective gonadotropin receptor trafficking.
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Affiliation(s)
- Claire L Newton
- Centre for Neuroendocrinology and Department of Immunology, Faculty of Health Sciences, University of Pretoria, PO Box 2034, Pretoria, 0001, South Africa.
| | - Ross C Anderson
- Centre for Neuroendocrinology and Department of Immunology, Faculty of Health Sciences, University of Pretoria, PO Box 2034, Pretoria, 0001, South Africa
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El Mountassir F, Belloir C, Briand L, Thomas-Danguin T, Le Bon AM. Encoding odorant mixtures by human olfactory receptors. FLAVOUR FRAG J 2016. [DOI: 10.1002/ffj.3331] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Fouzia El Mountassir
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRA; Univ. Bourgogne Franche-Comté; F-21000 Dijon France
| | - Christine Belloir
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRA; Univ. Bourgogne Franche-Comté; F-21000 Dijon France
| | - Loïc Briand
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRA; Univ. Bourgogne Franche-Comté; F-21000 Dijon France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRA; Univ. Bourgogne Franche-Comté; F-21000 Dijon France
| | - Anne-Marie Le Bon
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRA; Univ. Bourgogne Franche-Comté; F-21000 Dijon France
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Schaarschmidt J, Nagel MBM, Huth S, Jaeschke H, Moretti R, Hintze V, von Bergen M, Kalkhof S, Meiler J, Paschke R. Rearrangement of the Extracellular Domain/Extracellular Loop 1 Interface Is Critical for Thyrotropin Receptor Activation. J Biol Chem 2016; 291:14095-14108. [PMID: 27129207 DOI: 10.1074/jbc.m115.709659] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Indexed: 11/06/2022] Open
Abstract
The thyroid stimulating hormone receptor (TSHR) is a G protein-coupled receptor (GPCR) with a characteristic large extracellular domain (ECD). TSHR activation is initiated by binding of the hormone ligand TSH to the ECD. How the extracellular binding event triggers the conformational changes in the transmembrane domain (TMD) necessary for intracellular G protein activation is poorly understood. To gain insight in this process, the knowledge on the relative positioning of ECD and TMD and the conformation of the linker region at the interface of ECD and TMD are of particular importance. To generate a structural model for the TSHR we applied an integrated structural biology approach combining computational techniques with experimental data. Chemical cross-linking followed by mass spectrometry yielded 17 unique distance restraints within the ECD of the TSHR, its ligand TSH, and the hormone-receptor complex. These structural restraints generally confirm the expected binding mode of TSH to the ECD as well as the general fold of the domains and were used to guide homology modeling of the ECD. Functional characterization of TSHR mutants confirms the previously suggested close proximity of Ser-281 and Ile-486 within the TSHR. Rigidifying this contact permanently with a disulfide bridge disrupts ligand-induced receptor activation and indicates that rearrangement of the ECD/extracellular loop 1 (ECL1) interface is a critical step in receptor activation. The experimentally verified contact of Ser-281 (ECD) and Ile-486 (TMD) was subsequently utilized in docking homology models of the ECD and the TMD to create a full-length model of a glycoprotein hormone receptor.
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Affiliation(s)
- Joerg Schaarschmidt
- Department of Internal Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Marcus B M Nagel
- Department of Internal Medicine, University of Leipzig, 04103 Leipzig, Germany,; Department of Proteomics, Helmholtz-Centre for Environmental Research, 04318 Leipzig, Germany
| | - Sandra Huth
- Department of Internal Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Holger Jaeschke
- Department of Internal Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Rocco Moretti
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235
| | - Vera Hintze
- Institute of Materials Science, Max Bergmann Center of Biomaterials, TU Dresden, 01069 Dresden, Germany
| | - Martin von Bergen
- Department of Proteomics, Helmholtz-Centre for Environmental Research, 04318 Leipzig, Germany,; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, University of Leipzig, 04103 Leipzig, Germany,; Aalborg University, Department of Chemistry and Bioscience, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark
| | - Stefan Kalkhof
- Department of Proteomics, Helmholtz-Centre for Environmental Research, 04318 Leipzig, Germany,; Department of Bioanalytics, University of Applied Sciences and Arts of Coburg, 96450 Coburg, Germany
| | - Jens Meiler
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235
| | - Ralf Paschke
- Division of Endocrinology and Metabolism and Arnie Charbonneau Cancer Institute University of Calgary, Calgary, Alberta T2N 1N4, Canada.
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Dinter J, Khajavi N, Mühlhaus J, Wienchol CL, Cöster M, Hermsdorf T, Stäubert C, Köhrle J, Schöneberg T, Kleinau G, Mergler S, Biebermann H. The Multitarget Ligand 3-Iodothyronamine Modulates β-Adrenergic Receptor 2 Signaling. Eur Thyroid J 2015; 4:21-9. [PMID: 26601070 PMCID: PMC4640289 DOI: 10.1159/000381801] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/19/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND 3-Iodothyronamine (3-T1AM), a signaling molecule with structural similarities to thyroid hormones, induces numerous physiological responses including reversible body temperature decline. One target of 3-T1AM is the trace amine-associated receptor 1 (TAAR1), which is a member of the rhodopsin-like family of G protein-coupled receptors (GPCRs). Interestingly, the effects of 3-T1AM remain detectable in TAAR1 knockout mice, suggesting further targets for 3-T1AM such as adrenergic receptors. Therefore, we evaluated whether β-adrenergic receptor 1 (ADRB1) and 2 (ADRB2) signaling is affected by 3-T1AM in HEK293 cells and in human conjunctival epithelial cells (IOBA-NHC), where these receptors are highly expressed endogenously. METHODS A label-free EPIC system for prescreening the 3-T1AM-induced effects on ADRB1 and ADRB2 in transfected HEK293 cells was used. In addition, ADRB1 and ADRB2 activation was analyzed using a cyclic AMP assay and a MAPK reporter gene assay. Finally, fluorescence Ca(2+) imaging was utilized to delineate 3-T1AM-induced Ca(2+) signaling. RESULTS 3-T1AM (10(-5)-10(-10)M) enhanced isoprenaline-induced ADRB2-mediated Gs signaling but not that of ADRB1-mediated signaling. MAPK signaling remained unaffected for both receptors. In IOBA-NHC cells, norepinephrine-induced Ca(2+) influxes were blocked by the nonselective ADRB blocker timolol (10 µM), indicating that ADRBs are most likely linked with Ca(2+) channels. Notably, timolol was also found to block 3-T1AM (10(-5)M)-induced Ca(2+) influx. CONCLUSIONS The presented data support that 3-T1AM directly modulates β-adrenergic receptor signaling. The relationship between 3-T1AM and β-adrenergic signaling also reveals a potential therapeutic value for suppressing Ca(2+) channel-mediated inflammation processes, occurring in eye diseases such as conjunctivitis.
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Affiliation(s)
- Juliane Dinter
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | - Noushafarin Khajavi
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jessica Mühlhaus
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | | | - Maxi Cöster
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Thomas Hermsdorf
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Claudia Stäubert
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Torsten Schöneberg
- Institut für Biochemie, Molekulare Biochemie, Medizinische Fakultät, University of Leipzig, Leipzig, Germany
| | - Gunnar Kleinau
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
| | - Stefan Mergler
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische Endokrinologie, Berlin, Germany
- *Heike Biebermann, Institut für Experimentelle Pädiatrische Endokrinologie, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, DE-13353 Berlin (Germany), E-Mail , Stefan Mergler, Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, DE-13353 Berlin (Germany), E-Mail
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Derkach KV, Dar'in DV, Lobanov PS, Shpakov AO. Intratesticular, intraperitoneal, and oral administration of thienopyrimidine derivatives increases the testosterone level in male rats. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2015; 459:326-9. [PMID: 25560207 DOI: 10.1134/s0012496614060040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Indexed: 11/22/2022]
Affiliation(s)
- K V Derkach
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Morisa Toresa 44, St. Petersburg, 194223, Russia
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Nataraja SG, Yu HN, Palmer SS. Discovery and Development of Small Molecule Allosteric Modulators of Glycoprotein Hormone Receptors. Front Endocrinol (Lausanne) 2015; 6:142. [PMID: 26441832 PMCID: PMC4568768 DOI: 10.3389/fendo.2015.00142] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/31/2015] [Indexed: 11/30/2022] Open
Abstract
Glycoprotein hormones, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid-stimulating hormone (TSH) are heterodimeric proteins with a common α-subunit and hormone-specific β-subunit. These hormones are dominant regulators of reproduction and metabolic processes. Receptors for the glycoprotein hormones belong to the family of G protein-coupled receptors. FSH receptor (FSHR) and LH receptor are primarily expressed in somatic cells in ovary and testis to promote egg and sperm production in women and men, respectively. TSH receptor is expressed in thyroid cells and regulates the secretion of T3 and T4. Glycoprotein hormones bind to the large extracellular domain of the receptor and cause a conformational change in the receptor that leads to activation of more than one intracellular signaling pathway. Several small molecules have been described to activate/inhibit glycoprotein hormone receptors through allosteric sites of the receptor. Small molecule allosteric modulators have the potential to be administered orally to patients, thus improving the convenience of treatment. It has been a challenge to develop a small molecule allosteric agonist for glycoprotein hormones that can mimic the agonistic effects of the large natural ligand to activate similar signaling pathways. However, in the past few years, there have been several promising reports describing distinct chemical series with improved potency in preclinical models. In parallel, proposal of new structural model for FSHR and in silico docking studies of small molecule ligands to glycoprotein hormone receptors provide a giant leap on the understanding of the mechanism of action of the natural ligands and new chemical entities on the receptors. This review will focus on the current status of small molecule allosteric modulators of glycoprotein hormone receptors, their effects on common signaling pathways in cells, their utility for clinical application as demonstrated in preclinical models, and use of these molecules as novel tools to dissect the molecular signaling pathways of these receptors.
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Affiliation(s)
- Selvaraj G. Nataraja
- TocopheRx Inc., Burlington, MA, USA
- *Correspondence: Selvaraj G. Nataraja, TocopheRx Inc., 15 New England Executive Park, Suite 1087, Burlington, MA 01803, USA,
| | - Henry N. Yu
- TocopheRx Inc., Burlington, MA, USA
- EMD Serono Research and Development Institute Inc., Billerica, MA, USA
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18
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Shpakov AO, Dar'in DV, Derkach KV, Lobanov PS. The stimulating influence of thienopyrimidine compounds on the adenylyl cyclase signaling systems in the rat testes. DOKL BIOCHEM BIOPHYS 2014; 456:104-7. [PMID: 24993967 DOI: 10.1134/s1607672914030065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Indexed: 11/23/2022]
Affiliation(s)
- A O Shpakov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Morisa Toreza 44, St. Petersburg, 194223, Russia,
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19
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Kennedy DP, McRobb FM, Leonhardt SA, Purdy M, Figler H, Marshall MA, Chordia M, Figler R, Linden J, Abagyan R, Yeager M. The second extracellular loop of the adenosine A1 receptor mediates activity of allosteric enhancers. Mol Pharmacol 2014; 85:301-9. [PMID: 24217444 PMCID: PMC3913357 DOI: 10.1124/mol.113.088682] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 11/11/2013] [Indexed: 01/26/2023] Open
Abstract
Allosteric enhancers of the adenosine A1 receptor amplify signaling by orthosteric agonists. Allosteric enhancers are appealing drug candidates because their activity requires that the orthosteric site be occupied by an agonist, thereby conferring specificity to stressed or injured tissues that produce adenosine. To explore the mechanism of allosteric enhancer activity, we examined their action on several A1 receptor constructs, including (1) species variants, (2) species chimeras, (3) alanine scanning mutants, and (4) site-specific mutants. These findings were combined with homology modeling of the A1 receptor and in silico screening of an allosteric enhancer library. The binding modes of known docked allosteric enhancers correlated with the known structure-activity relationship, suggesting that these allosteric enhancers bind to a pocket formed by the second extracellular loop, flanked by residues S150 and M162. We propose a model in which this vestibule controls the entry and efflux of agonists from the orthosteric site and agonist binding elicits a conformational change that enables allosteric enhancer binding. This model provides a mechanism for the observations that allosteric enhancers slow the dissociation of orthosteric agonists but not antagonists.
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Affiliation(s)
- Dylan P Kennedy
- Department of Pharmacology (D.P.K.), Department of Molecular Physiology and Biological Physics (S.A.L., M.P., H.F., M.C., R.F., M.Y.), Cardiovascular Research Center (M.A.M., R.F., M.Y.), Center for Membrane Biology (M.Y.), and Department of Medicine, Division of Cardiovascular Medicine (M.Y.), University of Virginia School of Medicine, Charlottesville, Virginia; the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California (F.M.M., R.A.); and the La Jolla Institute for Allergy and Immunology (J.L.), La Jolla, California
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Kleinau G, Neumann S, Grüters A, Krude H, Biebermann H. Novel insights on thyroid-stimulating hormone receptor signal transduction. Endocr Rev 2013; 34:691-724. [PMID: 23645907 PMCID: PMC3785642 DOI: 10.1210/er.2012-1072] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The TSH receptor (TSHR) is a member of the glycoprotein hormone receptors, a subfamily of family A G protein-coupled receptors. The TSHR is of great importance for the growth and function of the thyroid gland. The TSHR and its endogenous ligand TSH are pivotal proteins with respect to a variety of physiological functions and malfunctions. The molecular events of TSHR regulation can be summarized as a process of signal transduction, including signal reception, conversion, and amplification. The steps during signal transduction from the extra- to the intracellular sites of the cell are not yet comprehensively understood. However, essential new insights have been achieved in recent years on the interrelated mechanisms at the extracellular region, the transmembrane domain, and intracellular components. This review contains a critical summary of available knowledge of the molecular mechanisms of signal transduction at the TSHR, for example, the key amino acids involved in hormone binding or in the structural conformational changes that lead to G protein activation or signaling regulation. Aspects of TSHR oligomerization, signaling promiscuity, signaling selectivity, phenotypes of genetic variations, and potential extrathyroidal receptor activity are also considered, because these are relevant to an understanding of the overall function of the TSHR, including physiological, pathophysiological, and pharmacological perspectives. Directions for future research are discussed.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Ostring 3, Augustenburger Platz 1, 13353 Berlin, Germany.
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Molecular sampling of the allosteric binding pocket of the TSH receptor provides discriminative pharmacophores for antagonist and agonists. Biochem Soc Trans 2013; 41:213-7. [PMID: 23356285 PMCID: PMC3561627 DOI: 10.1042/bst20120319] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The TSHR (thyrotropin receptor) is activated endogenously by the large hormone thyrotropin and activated pathologically by auto-antibodies. Both activate and bind at the extracellular domain. Recently, SMLs (small-molecule ligands) have been identified, which bind in an allosteric binding pocket within the transmembrane domain. Modelling driven site-directed mutagenesis of amino acids lining this pocket led to the delineation of activation and inactivation sensitive residues. Modified residues showing CAMs (constitutively activating mutations) indicate signalling-sensitive positions and mark potential trigger points for agonists. Silencing mutations lead to an impairment of basal activity and mark contact points for antagonists. Mapping these residues on to a structural model of TSHR indicates locations where an SML may switch the receptor to an inactive or active conformation. In the present article, we report the effects of SMLs on these signalling-sensitive amino acids at the TSHR. Surprisingly, the antagonistic effect of SML compound 52 was reversed to an agonistic effect, when tested at the CAM Y667A. Switching agonism to antagonism and the reverse by changing either SMLs or residues covering the binding pocket provides detailed knowledge about discriminative pharmacophores. It prepares the basis for rational optimization of new high-affinity antagonists to interfere with the pathogenic activation of the TSHR.
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Troppmann B, Kleinau G, Krause G, Gromoll J. Structural and functional plasticity of the luteinizing hormone/choriogonadotrophin receptor. Hum Reprod Update 2013; 19:583-602. [DOI: 10.1093/humupd/dmt023] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Dupakuntla M, Pathak B, Roy BS, Mahale SD. Extracellular loop 2 in the FSH receptor is crucial for ligand mediated receptor activation. Mol Cell Endocrinol 2012; 362:60-8. [PMID: 22641019 DOI: 10.1016/j.mce.2012.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 05/17/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
The present study aims to determine the role of the specific residues of the extracellular loops (ELs) of the FSH receptor (FSHR) in hormone binding and receptor activation. By substituting the sequences of each of the ELs of human FSHR with those of the luteinizing hormone/choriogonadotropin receptor (LH/CGR), we generated three mutant constructs where the three ELs were individually replaced. A fourth construct had all the three substituted ELs. The receptor expression and hormone binding ability of the mutants were comparable to that of the wild type. Hormone-induced signaling and internalization were lower in the EL2 substitution mutant (EL2M). In this mutant, the EL2 of FSHR was substituted with the corresponding loop of LH/CGR. Interestingly, homology modeling revealed a change in the orientation of EL2 in the mutant receptor. Thus, disruption of EL2 affected overall receptor function, suggesting the role of FSHR specific residues of the loop in ligand mediated signaling.
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Affiliation(s)
- Madhavi Dupakuntla
- Division of Structural Biology, National Institute for Research in Reproductive Health (Indian Council of Medical Research), Parel, Mumbai 400 012, India
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Allosteric modulators of rhodopsin-like G protein-coupled receptors: opportunities in drug development. Pharmacol Ther 2012; 135:292-315. [PMID: 22728155 DOI: 10.1016/j.pharmthera.2012.06.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
Abstract
Rhodopsin-like (class A) G protein-coupled receptors (GPCRs) are one of the most important classes of drug targets. The discovery that these GPCRs can be allosterically modulated by small drug molecules has opened up new opportunities in drug development. It will allow the drugability of "difficult targets", such as GPCRs activated by large (glyco)proteins, or by very polar or highly lipophilic physiological agonists. Receptor subtype selectivity should be more easily achievable with allosteric than with orthosteric ligands. Allosteric modulation will allow a broad spectrum of pharmacological effects largely expanding that of orthosteric ligands. Furthermore, allosteric modulators may show an improved safety profile as compared to orthosteric ligands. Only recently, the explicit search for allosteric modulators has been started for only a few rhodopsin-like GPCRs. The first negative allosteric modulators (allosteric antagonists) of chemokine receptors, maraviroc (CCR5 receptor), used in HIV therapy, and plerixafor (CXCR4 receptor) for stem cell mobilization, have been approved as drugs. The development of allosteric modulators for rhodopsin-like GPCRs as novel drugs is still at an early stage; it appears highly promising.
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