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Boan AF, Delgadin TH, Canosa LF, Fernandino JI. Loss of function in somatostatin receptor 5 has no impact on the growth of medaka fish due to compensation by the other paralogs. Gen Comp Endocrinol 2024; 351:114478. [PMID: 38412943 DOI: 10.1016/j.ygcen.2024.114478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/29/2024]
Abstract
Somatic growth in vertebrates is regulated endocrinologically by the somatotropic axis, headed by the growth hormone (GH) and the insulin growth factor-I (IGF-I). Somatostatin (Sst), a peptide hormone synthesized in the hypothalamus, modulates GH actions through its receptors (Sstr). Four Sstr subtypes (Sstr 1-3 and 5) have been identified in teleosts. However, little is known about whether they have a specific function or tissue expression. The aim of this study was to determine the role of sstr2 and sstr5 in the growth of the medaka (Oryzias latipes). The assessed expression pattern across diverse tissues highlighted greater prevalence of sstr1 and sstr3 in brain, intestine and muscle than in pituitary or liver. The expression of sstr2 was high in all the tissues tested, while sstr5 was predominantly expressed in the pituitary gland. A CRISPR/Cas9 sstr5 mutant with loss of function (sstr5-/-) was produced. Assessment of sstr5-/- indicated no significant difference with the wild type regarding growth parameters such as standard length, body depth, or peduncle depth. Furthermore, the functional loss of sstr5 had no impact on the response to a nutritional challenge. The fact that several sstr subtypes were upregulated in different tissues in sstr5-/- medaka suggests that in the mutant fish, there may be a compensatory effect on the different tissues, predominantly by sstr1 in the liver, brain and pituitary, with sstr2 being upregulated in pituitary and liver, and sstr3 only presenting differential expression in the brain. Analysis of the sstr subtype and the sstr5-/- fish showed that sstr5 was not the only somatostatin receptor responsible for Sst-mediated Gh regulation.
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Affiliation(s)
- A F Boan
- Instituto Tecnológico de Chascomús, INTECH (CONICET-UNSAM), Chascomús, Argentina; Escuela de Bio y Nanotecnologías (UNSAM), Chascomús, Argentina
| | - T H Delgadin
- Universidad Nacional del Santa, Nuevo Chimbote, Ancash, Perú
| | - L F Canosa
- Instituto Tecnológico de Chascomús, INTECH (CONICET-UNSAM), Chascomús, Argentina; Escuela de Bio y Nanotecnologías (UNSAM), Chascomús, Argentina
| | - J I Fernandino
- Instituto Tecnológico de Chascomús, INTECH (CONICET-UNSAM), Chascomús, Argentina; Escuela de Bio y Nanotecnologías (UNSAM), Chascomús, Argentina.
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Park SR, Kook MG, Kim SR, Lee JW, Yu YS, Park CH, Lim S, Oh BC, Jung Y, Hong IS. A microscale 3D organ on a chip for recapitulating reciprocal neuroendocrine crosstalk between the hypothalamus and the pituitary gland. Biofabrication 2024; 16:025011. [PMID: 38277677 DOI: 10.1088/1758-5090/ad22f1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 01/26/2024] [Indexed: 01/28/2024]
Abstract
Conventional 2D or even recently developed 3Din vitroculture models for hypothalamus and pituitary gland cannot successfully recapitulate reciprocal neuroendocrine communications between these two pivotal neuroendocrine tissues known to play an essential role in controlling the body's endocrine system, survival, and reproduction. In addition, most currentvitroculture models for neuroendocrine tissues fail to properly reflect their complex multicellular structure. In this context, we developed a novel microscale chip platform, termed the 'hypothalamic-pituitary (HP) axis-on-a-chip,' which integrates various cellular components of the hypothalamus and pituitary gland with biomaterials such as collagen and hyaluronic acid. We used non-toxic blood coagulation factors (fibrinogen and thrombin) as natural cross-linking agents to increase the mechanical strength of biomaterials without showing residual toxicity to overcome drawbacks of conventional chemical cross-linking agents. Furthermore, we identified and verified SERPINB2 as a reliable neuroendocrine toxic marker, with its expression significantly increased in both hypothalamus and pituitary gland cells following exposure to various types of toxins. Next, we introduced SERPINB2-fluorescence reporter system into loaded hypothalamic cells and pituitary gland cells within each chamber of the HP axis on a chip, respectively. By incorporating this SERPINB2 detection system into the loaded hypothalamic and pituitary gland cells within our chip platform, Our HP axis-on-chip platform can better mimic reciprocal neuroendocrine crosstalk between the hypothalamus and the pituitary gland in the brain microenvironments with improved efficiency in evaluating neuroendocrine toxicities of certain drug candidates.
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Affiliation(s)
- Se-Ra Park
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Myung Geun Kook
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Soo-Rim Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Jin Woo Lee
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Young Soo Yu
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Chan Hum Park
- Department of Otolaryngology-Head and Neck Surgery, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Soyi Lim
- Gachon University Gil Hospital VIP Health Promotion Center, Incheon, Republic of Korea
| | - Byung-Chul Oh
- Department of Physiology, Lee Gil Ya Cancer and Diabetes Institute, Gachon University College of Medicine, Incheon 21999, Republic of Korea
| | - YunJae Jung
- Department of Microbiology, College of Medicine, Gachon University, Incheon 21999, Republic of Korea
| | - In-Sun Hong
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
- Department of Molecular Medicine, School of Medicine, Gachon University, Incheon 406-840, Republic of Korea
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3
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Brockway DF, Griffith KR, Aloimonos CM, Clarity TT, Moyer JB, Smith GC, Dao NC, Hossain MS, Drew PJ, Gordon JA, Kupferschmidt DA, Crowley NA. Somatostatin peptide signaling dampens cortical circuits and promotes exploratory behavior. Cell Rep 2023; 42:112976. [PMID: 37590138 PMCID: PMC10542913 DOI: 10.1016/j.celrep.2023.112976] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/31/2023] [Accepted: 07/29/2023] [Indexed: 08/19/2023] Open
Abstract
We sought to characterize the unique role of somatostatin (SST) in the prelimbic (PL) cortex in mice. We performed slice electrophysiology in pyramidal and GABAergic neurons to characterize the pharmacological mechanism of SST signaling and fiber photometry of GCaMP6f fluorescent calcium signals from SST neurons to characterize the activity profile of SST neurons during exploration of an elevated plus maze (EPM) and open field test (OFT). We used local delivery of a broad SST receptor (SSTR) agonist and antagonist to test causal effects of SST signaling. SSTR activation hyperpolarizes layer 2/3 pyramidal neurons, an effect that is recapitulated with optogenetic stimulation of SST neurons. SST neurons in PL are activated during EPM and OFT exploration, and SSTR agonist administration directly into the PL enhances open arm exploration in the EPM. This work describes a broad ability for SST peptide signaling to modulate microcircuits within the prefrontal cortex and related exploratory behaviors.
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Affiliation(s)
- Dakota F Brockway
- Neuroscience Graduate Program, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Keith R Griffith
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Chloe M Aloimonos
- Integrative Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas T Clarity
- Integrative Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - J Brody Moyer
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Grace C Smith
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Nigel C Dao
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Md Shakhawat Hossain
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Patrick J Drew
- Neuroscience Graduate Program, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Departments of Engineering Science and Mechanics and Neurosurgery, The Pennsylvania State University, University Park, PA 16802, USA
| | - Joshua A Gordon
- Integrative Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Office of the Director, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A Kupferschmidt
- Integrative Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole A Crowley
- Neuroscience Graduate Program, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
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Modena D, Moras ML, Sandrone G, Stevenazzi A, Vergani B, Dasgupta P, Kliever A, Gulde S, Marangelo A, Schillmaier M, Luque RM, Bäuerle S, Pellegata NS, Schulz S, Steinkühler C. Identification of a Novel SSTR3 Full Agonist for the Treatment of Nonfunctioning Pituitary Adenomas. Cancers (Basel) 2023; 15:3453. [PMID: 37444563 DOI: 10.3390/cancers15133453] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Somatostatin receptor (SSTR) agonists have been extensively used for treating neuroendocrine tumors. Synthetic therapeutic agonists showing selectivity for SSTR2 (Octreotide) or for SSTR2 and SSTR5 (Pasireotide) have been approved for the treatment of patients with acromegaly and Cushing's syndrome, as their pituitary tumors highly express SSTR2 or SSTR2/SSTR5, respectively. Nonfunctioning pituitary adenomas (NFPAs), which express high levels of SSTR3 and show only modest response to currently available SSTR agonists, are often invasive and cannot be completely resected, and therefore easily recur. The aim of the present study was the evaluation of ITF2984, a somatostatin analog and full SSTR3 agonist, as a new potential treatment for NFPAs. ITF2984 shows a 10-fold improved affinity for SSTR3 compared to Octreotide or Pasireotide. Molecular modeling and NMR studies indicated that the higher affinity for SSTR3 correlates with a higher stability of a distorted β-I turn in the cyclic peptide backbone. ITF2984 induces receptor internalization and phosphorylation, and triggers G-protein signaling at pharmacologically relevant concentrations. Furthermore, ITF2984 displays antitumor activity that is dependent on SSTR3 expression levels in the MENX (homozygous mutant) NFPA rat model, which closely recapitulates human disease. Therefore, ITF2984 may represent a novel therapeutic option for patients affected by NFPA.
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Affiliation(s)
- Daniela Modena
- Preclinical R&D, Italfarmaco Group, 20092 Cinisello Balsamo, Milan, Italy
| | - Maria Luisa Moras
- Preclinical R&D, Italfarmaco Group, 20092 Cinisello Balsamo, Milan, Italy
| | - Giovanni Sandrone
- Preclinical R&D, Italfarmaco Group, 20092 Cinisello Balsamo, Milan, Italy
| | - Andrea Stevenazzi
- Preclinical R&D, Italfarmaco Group, 20092 Cinisello Balsamo, Milan, Italy
| | - Barbara Vergani
- Preclinical R&D, Italfarmaco Group, 20092 Cinisello Balsamo, Milan, Italy
| | - Pooja Dasgupta
- Institute of Pharmacology and Toxicology, Universitätsklinikum Jena, Friedrich-Schiller-Universität, 07747 Jena, Germany
| | - Andrea Kliever
- Institute of Pharmacology and Toxicology, Universitätsklinikum Jena, Friedrich-Schiller-Universität, 07747 Jena, Germany
| | - Sebastian Gulde
- Institute for Diabetes and Cancer, Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Alessandro Marangelo
- Institute for Diabetes and Cancer, Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Mathias Schillmaier
- Department of Nuclear Medicine, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, 80333 Munich, Germany
- Department of Diagnostic and Interventional Radiology, Klinikum Rechts der Isar, School of Medicine, Technical University of Munich, 80333 Munich, Germany
| | - Raul M Luque
- Maimonides Biomedical Research Institute of Cordoba (IMIBIC), 14004 Cordoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain
- Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain
| | - Stephen Bäuerle
- Department of Mathematics, Technical University Munich, 85748 Garching, Germany
| | - Natalia S Pellegata
- Institute for Diabetes and Cancer, Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Universitätsklinikum Jena, Friedrich-Schiller-Universität, 07747 Jena, Germany
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5
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Martino M, Aboud N, Lucchetti B, Salvio G, Arnaldi G. An evaluation of pharmacological options for Cushing's disease: what are the state-of-the-art options? Expert Opin Pharmacother 2023; 24:557-576. [PMID: 36927238 DOI: 10.1080/14656566.2023.2192349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
INTRODUCTION Untreated Cushing's syndrome (CS) is associated with significant morbidity and mortality. Cortisol normalization is a key goal to treatment. Pituitary surgery remains the first-line approach for Cushing's disease, but sometimes it is impracticable, unsuccessful, or complicated by recurrence. Medical therapy has been historically considered a palliative. However, in the latest years, interest on this topic has grown due to both the availability of new drugs and the reevaluation of the old, commonly used drugs in clinical practice. AREAS COVERED In this article, we will discuss the current options and future directions of medical therapy for CS, aiming at fitting best patients' features. An extensive literature search regarding already approved and investigational principles was conducted (PubMed, ClinicalTrials.gov. Available drugs include inhibitors of ACTH secretion, steroidogenesis inhibitors, and glucocorticoid receptor antagonists; drugs acting at different levels can be also combined in uncontrolled patients. EXPERT OPINION Since there is still no standardized pharmacological approach and the superiority of one drug over another has not been established yet in the absence of comparative studies, each time clinicians' choices should be patient-tailored. Age, gender, tumor features, severity of hypercortisolism, comorbidities/complications, rapidity of action, side effects, drug-drug interactions, contraindications, availability, patients' preferences, and costs should be all considered.
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Affiliation(s)
- Marianna Martino
- Division of Endocrinology and Metabolic Diseases, Department of Clinical and Molecular Sciences (DISCLIMO). Polytechnic University of Marche Ancona, Italy
| | - Nairus Aboud
- Division of Endocrinology and Metabolic Diseases, Department of Clinical and Molecular Sciences (DISCLIMO). Polytechnic University of Marche Ancona, Italy
| | - Beatrice Lucchetti
- Division of Endocrinology and Metabolic Diseases, Department of Clinical and Molecular Sciences (DISCLIMO). Polytechnic University of Marche Ancona, Italy
| | - Gianmaria Salvio
- Division of Endocrinology and Metabolic Diseases, Department of Clinical and Molecular Sciences (DISCLIMO). Polytechnic University of Marche Ancona, Italy
| | - Giorgio Arnaldi
- Division of Endocrinology and Metabolic Diseases, Department of Clinical and Molecular Sciences (DISCLIMO). Polytechnic University of Marche Ancona, Italy
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Kaufmann J, Blum NK, Nagel F, Schuler A, Drube J, Degenhart C, Engel J, Eickhoff JE, Dasgupta P, Fritzwanker S, Guastadisegni M, Schulte C, Miess-Tanneberg E, Maric HM, Spetea M, Kliewer A, Baumann M, Klebl B, Reinscheid RK, Hoffmann C, Schulz S. A bead-based GPCR phosphorylation immunoassay for high-throughput ligand profiling and GRK inhibitor screening. Commun Biol 2022; 5:1206. [PMID: 36352263 PMCID: PMC9646841 DOI: 10.1038/s42003-022-04135-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 10/19/2022] [Indexed: 11/10/2022] Open
Abstract
Analysis of agonist-driven phosphorylation of G protein-coupled receptors (GPCRs) can provide valuable insights into the receptor activation state and ligand pharmacology. However, to date, assessment of GPCR phosphorylation using high-throughput applications has been challenging. We have developed and validated a bead-based immunoassay for the quantitative assessment of agonist-induced GPCR phosphorylation that can be performed entirely in multiwell cell culture plates. The assay involves immunoprecipitation of affinity-tagged receptors using magnetic beads followed by protein detection using phosphorylation state-specific and phosphorylation state-independent anti-GPCR antibodies. As proof of concept, five prototypical GPCRs (MOP, C5a1, D1, SST2, CB2) were treated with different agonizts and antagonists, and concentration-response curves were generated. We then extended our approach to establish selective cellular GPCR kinase (GRK) inhibitor assays, which led to the rapid identification of a selective GRK5/6 inhibitor (LDC8988) and a highly potent pan-GRK inhibitor (LDC9728). In conclusion, this versatile GPCR phosphorylation assay can be used extensively for ligand profiling and inhibitor screening. A G protein-coupled receptors (GPCRs) phosphorylation assay for cell culture plates can be used for ligand profiling and inhibitor screening, as evidenced by the identification of two GRK inhibitor compounds.
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Pharmacological Characterization of Veldoreotide as a Somatostatin Receptor 4 Agonist. Life (Basel) 2021; 11:life11101075. [PMID: 34685446 PMCID: PMC8541358 DOI: 10.3390/life11101075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/01/2021] [Accepted: 10/07/2021] [Indexed: 12/12/2022] Open
Abstract
Veldoreotide, a somatostatin analogue, binds to the somatostatin receptors (SSTR) 2, 4, and 5. The current aim was to assess its pharmacological activity as an SSTR4 agonist. G-protein signaling was assessed using a fluorescence-based membrane potential assay in human embryonic kidney 293 (HEK293) cells stably co-expressing G-protein-coupled inwardly rectifying potassium 2 channels and the individual SSTR2, SSTR4, and SSTR5, and in human BON-1 cells stably expressing these SSTRs. Veldoreotide effects on chromogranin A (CgA) secretion and cell proliferation were examined in BON-1 cells. In HEK293 transfected cells, veldoreotide showed a high efficacy for activating the SSTR4; octreotide and pasireotide had little activity (Emax, 99.5% vs. 27.4% and 52.0%, respectively). Veldoreotide also activated SSTR2 and SSTR5 (Emax, 98.4% and 96.9%, respectively). In BON-1 cells, veldoreotide activated SSTR2, SSTR4, and SSTR5 with high potency and efficacy. CgA secretion was decreased to a greater degree in the BON-1 cells expressing SSTR4 versus the cells expressing SSTR2 and SSTR5 (65.3% vs. 80.3% and 77.6%, respectively). In the BON-1 cells expressing SSTR4, veldoreotide inhibited cell proliferation more than somatostatin SS-14 (71.2% vs. 79.7%) and to a similar extent as the SSTR4 agonist J-2156 in the presence of SSTR2 and SSTR5 antagonists. Veldoreotide is a full agonist of SSTR2, SSTR4, and SSTR5.
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Cuny T, Graillon T, Defilles C, Datta R, Zhang S, Figarella-Branger D, Dufour H, Mougel G, Brue T, Landsman T, Halem HA, Culler MD, Barlier A, Saveanu A. Characterization of the ability of a, second-generation SST-DA chimeric molecule, TBR-065, to suppress GH secretion from human GH-secreting adenoma cells. Pituitary 2021; 24:351-358. [PMID: 33433890 DOI: 10.1007/s11102-020-01113-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/17/2020] [Indexed: 12/19/2022]
Abstract
CONTEXT Somatostatin (SST) and dopamine (DA) inhibit growth hormone (GH) secretion and proliferation of GH-secreting pituitary adenomas (GHomas) through binding to SSTR2 and D2R receptors. Chimeric SST-DA compounds (Dopastatins) display increased potency in inhibiting GH secretion, as compared with individual SST or DA analogs (alone or combined). OBJECTIVE To assess the efficacy of a second-generation dopastatin, TBR-065, in suppressing GH secretion from human GH- and GH/prolactin(PRL)-omas. DESIGN We compared the ability of TBR-065 to inhibit GH secretion from primary cultures of human GH- or GH/PRLoma cells to that of the first generation dopastatin, TBR-760 (formerly BIM-23A760), octreotide (OCT) and cabergoline (CAB), the later either alone or combined. We investigated whether there was any impact of BIM-133, the metabolite of TBR-065, on the ability of TBR-065 to inhibit GH in these cultures. METHODS 17 GH- and GH/PRLomas were included in this study. Inhibition of GH secretion by TBR-065, TBR-760, OCT and CAB (0.1 pM to 0.1 µM) was assessed over a period of 8 h. RESULTS All tumors expressed SSTR2 and D2R mRNAs. GH suppression was higher with TBR-065 as compared with TBR-760 (Emax = 57 ± 5.6% vs. 41.1 ± 12.5%, respectively, p < 0.001) or with OCT + CAB (Emax = 56.8 ± 7.2% vs. 44.4 ± 9.4%, p < 0.001). BIM-133 did not have any impact on the activity of TBR-065. CONCLUSION TBR-065 has significantly improved efficacy in suppressing GH secretion as compared to current available therapies and may represent a new promising option for the treatment of acromegaly.
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Affiliation(s)
- Thomas Cuny
- Service d'Endocrinologie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, 147 Boulevard Baille, 13005, Marseille, France.
| | - Thomas Graillon
- Service de Neurochirurgie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Timone, Marseille, France
| | - Célines Defilles
- Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Marseille, France
| | - Rakesh Datta
- Ipsen Bioscience (Formers Employees), Cambridge, MA, USA
| | - Shengwen Zhang
- Ipsen Bioscience (Formers Employees), Cambridge, MA, USA
| | | | - Henry Dufour
- Service de Neurochirurgie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Timone, Marseille, France
| | - Grégory Mougel
- Laboratoire de Biologie Moléculaire et Biochimie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, Marseille, France
| | - Thierry Brue
- Service d'Endocrinologie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, 147 Boulevard Baille, 13005, Marseille, France
| | - Tanya Landsman
- Ipsen Bioscience (Formers Employees), Cambridge, MA, USA
| | | | | | - Anne Barlier
- Laboratoire de Biologie Moléculaire et Biochimie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, Marseille, France
| | - Alexandru Saveanu
- Laboratoire de Biologie Moléculaire et Biochimie, Aix Marseille University, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, Marseille, France
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9
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Lu JJ, Polgar WE, Mann A, Dasgupta P, Schulz S, Zaveri NT. Differential In Vitro Pharmacological Profiles of Structurally Diverse Nociceptin Receptor Agonists in Activating G Protein and Beta-Arrestin Signaling at the Human Nociceptin Opioid Receptor. Mol Pharmacol 2021; 100:7-18. [PMID: 33958480 DOI: 10.1124/molpharm.120.000076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/26/2021] [Indexed: 11/22/2022] Open
Abstract
Agonists at the nociceptin opioid peptide receptor (NOP) are under investigation as therapeutics for nonaddicting analgesia, opioid use disorder, Parkinson's disease, and other indications. NOP full and partial agonists have both been of interest, particularly since NOP partial agonists show a reduced propensity for behavioral disruption than NOP full agonists. Here, we investigated the in vitro pharmacological properties of chemically diverse NOP receptor agonists in assays measuring functional activation of the NOP receptor such as guanosine 5'-O-[gamma-thio]triphosphate (GTPγS) binding, cAMP inhibition, G protein-coupled inwardly rectifying potassium (GIRK) channel activation, phosphorylation, β-arrestin recruitment and receptor internalization. When normalized to the efficacy of the natural agonist nociceptin/orphanin FQ (N/OFQ), we found that different functional assays that measure intrinsic activity produce inconsistent levels of agonist efficacy, particularly for ligands that were partial agonists. Agonist efficacy obtained in the GTPγS assay tended to be lower than that in the cAMP and GIRK assays. These structurally diverse NOP agonists also showed differential receptor phosphorylation profiles at the phosphosites we examined and induced varying levels of receptor internalization. Interestingly, although the rank order for β-arrestin recruitment by these NOP agonists was consistent with their ability to induce receptor internalization, their phosphorylation signatures at the time point we investigated were not indicative of the levels of β-arrestin recruitment or internalization induced by these agonists. It is possible that other phosphorylation sites, yet to be identified, drive the recruitment of NOP receptor ensembles and subsequent receptor trafficking by some nonpeptide NOP agonists. These findings potentially help understand NOP agonist pharmacology in the context of ligand-activated receptor trafficking. SIGNIFICANCE STATEMENT: Chemically diverse agonist ligands at the nociceptin opioid receptor G protein-coupled receptor showed differential efficacy for activating downstream events after receptor binding, in a suite of functional assays measuring guanosine 5'-O-[gamma-thio]triphosphate binding, cAMP inhibition, G protein-coupled inwardly rectifying protein channel activation, β-arrestin recruitment, receptor internalization and receptor phosphorylation. These analyses provide a context for understanding nociceptin opioid peptide receptor (NOP) agonist pharmacology driven by ligand-induced differential NOP receptor signaling.
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Affiliation(s)
- James J Lu
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
| | - Willma E Polgar
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
| | - Anika Mann
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
| | - Pooja Dasgupta
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
| | - Stefan Schulz
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
| | - Nurulain T Zaveri
- Astraea Therapeutics, Mountain View, California (J.J.L., W.E.P., N.T.Z.); and Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany (A.M., P.D., S.S.)
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10
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Mann A, Keen AC, Mark H, Dasgupta P, Javitch JA, Canals M, Schulz S, Robert Lane J. New phosphosite-specific antibodies to unravel the role of GRK phosphorylation in dopamine D 2 receptor regulation and signaling. Sci Rep 2021; 11:8288. [PMID: 33859231 PMCID: PMC8050214 DOI: 10.1038/s41598-021-87417-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
The dopamine D2 receptor (D2R) is the target of drugs used to treat the symptoms of Parkinson’s disease and schizophrenia. The D2R is regulated through its interaction with and phosphorylation by G protein receptor kinases (GRKs) and interaction with arrestins. More recently, D2R arrestin-mediated signaling has been shown to have distinct physiological functions to those of G protein signalling. Relatively little is known regarding the patterns of D2R phosphorylation that might control these processes. We aimed to generate antibodies specific for intracellular D2R phosphorylation sites to facilitate the investigation of these mechanisms. We synthesised double phosphorylated peptides corresponding to regions within intracellular loop 3 of the hD2R and used them to raise phosphosite-specific antibodies to capture a broad screen of GRK-mediated phosphorylation. We identify an antibody specific to a GRK2/3 phosphorylation site in intracellular loop 3 of the D2R. We compared measurements of D2R phosphorylation with other measurements of D2R signalling to profile selected D2R agonists including previously described biased agonists. These studies demonstrate the utility of novel phosphosite-specific antibodies to investigate D2R regulation and signalling.
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Affiliation(s)
- Anika Mann
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Alastair C Keen
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.,Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Hanka Mark
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Pooja Dasgupta
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Jonathan A Javitch
- Departments of Psychiatry and Pharmacology, Vagelos College of Physicians and Surgeons, Columbia University, New York, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, USA
| | - Meritxell Canals
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany.
| | - J Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK. .,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK.
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11
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Agonist-induced phosphorylation bar code and differential post-activation signaling of the delta opioid receptor revealed by phosphosite-specific antibodies. Sci Rep 2020; 10:8585. [PMID: 32444688 PMCID: PMC7244497 DOI: 10.1038/s41598-020-65589-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/05/2020] [Indexed: 01/08/2023] Open
Abstract
The δ-opioid receptor (DOP) is an attractive pharmacological target due to its potent analgesic, anxiolytic and anti-depressant activity in chronic pain models. However, some but not all selective DOP agonists also produce severe adverse effects such as seizures. Thus, the development of novel agonists requires a profound understanding of their effects on DOP phosphorylation, post-activation signaling and dephosphorylation. Here we show that agonist-induced DOP phosphorylation at threonine 361 (T361) and serine 363 (S363) proceeds with a temporal hierarchy, with S363 as primary site of phosphorylation. This phosphorylation is mediated by G protein-coupled receptor kinases 2 and 3 (GRK2/3) followed by DOP endocytosis and desensitization. DOP dephosphorylation occurs within minutes and is predominantly mediated by protein phosphatases (PP) 1α and 1β. A comparison of structurally diverse DOP agonists and clinically used opioids demonstrated high correlation between G protein-dependent signaling efficacies and receptor internalization. In vivo, DOP agonists induce receptor phosphorylation in a dose-dependent and agonist-selective manner that could be blocked by naltrexone in DOP-eGFP mice. Together, our studies provide novel tools and insights for ligand-activated DOP signaling in vitro and in vivo and suggest that DOP agonist efficacies may determine receptor post-activation signaling.
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12
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Walsh KB. Screening Technologies for Inward Rectifier Potassium Channels: Discovery of New Blockers and Activators. SLAS DISCOVERY 2020; 25:420-433. [PMID: 32292089 DOI: 10.1177/2472555220905558] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
K+ channels play a critical role in maintaining the normal electrical activity of excitable cells by setting the cell resting membrane potential and by determining the shape and duration of the action potential. In nonexcitable cells, K+ channels establish electrochemical gradients necessary for maintaining salt and volume homeostasis of body fluids. Inward rectifier K+ (Kir) channels typically conduct larger inward currents than outward currents, resulting in an inwardly rectifying current versus voltage relationship. This property of inward rectification results from the voltage-dependent block of the channels by intracellular polyvalent cations and makes these channels uniquely designed for maintaining the resting potential near the K+ equilibrium potential (EK). The Kir family of channels consist of seven subfamilies of channels (Kir1.x through Kir7.x) that include the classic inward rectifier (Kir2.x) channel, the G-protein-gated inward rectifier K+ (GIRK) (Kir3.x), and the adenosine triphosphate (ATP)-sensitive (KATP) (Kir 6.x) channels as well as the renal Kir1.1 (ROMK), Kir4.1, and Kir7.1 channels. These channels not only function to regulate electrical/electrolyte transport activity, but also serve as effector molecules for G-protein-coupled receptors (GPCRs) and as molecular sensors for cell metabolism. Of significance, Kir channels represent promising pharmacological targets for treating a number of clinical conditions, including cardiac arrhythmias, anxiety, chronic pain, and hypertension. This review provides a brief background on the structure, function, and pharmacology of Kir channels and then focuses on describing and evaluating current high-throughput screening (HTS) technologies, such as membrane potential-sensitive fluorescent dye assays, ion flux measurements, and automated patch clamp systems used for Kir channel drug discovery.
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Affiliation(s)
- Kenneth B Walsh
- Department of Pharmacology, Physiology & Neuroscience, School of Medicine, University of South Carolina, Columbia, SC, USA
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13
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Gadgaard C, Jensen AA. Functional characterization of 5-HT 1A and 5-HT 1B serotonin receptor signaling through G-protein-activated inwardly rectifying K + channels in a fluorescence-based membrane potential assay. Biochem Pharmacol 2020; 175:113870. [PMID: 32088264 DOI: 10.1016/j.bcp.2020.113870] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/18/2020] [Indexed: 11/15/2022]
Abstract
The 5-HT1A and 5-HT1B serotonin receptors are abundantly expressed in the CNS and constitute validated as well as putative drug targets in a variety of psychiatric and cognitive disorders, alcoholism/addiction, pain and migraine. In the present study we have characterized the functional properties of human 5-HT1A and 5-HT1B stably co-expressed with the human G-protein-activated inwardly rectifying K+ channel 2 (GIRK2) in HEK293 cells in the fluorescence-based FLIPR® Membrane Potential Blue (FMP) assay. Serotonin and other agonists induced robust decreases in fluorescence levels in the 5-HT1A/GIRK2- and 5-HT1B/GIRK2-HEK293 cells in a concentration-dependent manner in the assay, and these responses could be inhibited by selective 5-HT1A/5-HT1B antagonists and by the Gαi/o-protein inhibitor pertussis toxin (PTX). Five additional stable HEK293 cell lines co-expressing 5-HT1A or 5-HT1B with GIRK2 and one of the PTX-insensitive Gαi/o-subunit mutants Gαi1C351I, Gαi2C352I and Gαo1C351I were constructed, and 5-HT1A/5-HT1B-mediated responses through these specific Gαi/o-subunits were measured in these cells pretreated with PTX in the FMP assay. The functional properties of 16 reference 5-HT1 agonists were characterized at the seven cell lines, which constitutes the most detailed pharmacological profiling and comparison of 5-HT1A and 5-HT1B receptor signaling in the same assay published to date. We propose that this approach to assay 5-HT1-mediated signaling through endogenous Gαi/o-proteins in HEK293 cells or through specific Gαi/o-subunits in a fairly high-throughput manner holds some advantages to other functional assays for Gαi/o-coupled receptors. The assay will facilitate detailed profiling of the Gαi/o- and Gβγ-mediated signaling of 5-HT1A and 5-HT1B at the molecular level, and it could also be used to identify novel modulators for the receptors.
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Affiliation(s)
- Camilla Gadgaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
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14
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Sachdev S, Boyd R, Grimsey NL, Santiago M, Connor M. Brodifacoum does not modulate human cannabinoid receptor-mediated hyperpolarization of AtT20 cells or inhibition of adenylyl cyclase in HEK 293 cells. PeerJ 2019; 7:e7733. [PMID: 31579608 PMCID: PMC6765355 DOI: 10.7717/peerj.7733] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/23/2019] [Indexed: 01/04/2023] Open
Abstract
Background Synthetic cannabinoids are a commonly used class of recreational drugs that can have significant adverse effects. There have been sporadic reports of co-consumption of illicit drugs with rodenticides such as warfarin and brodifacoum (BFC) over the past 20 years but recently, hundreds of people have been reported to have been poisoned with a mixture of synthetic cannabinoids and BFC. We have sought to establish whether BFC directly affects cannabinoid receptors, or their activation by the synthetic cannabinoid CP55940 or the phytocannabinoid Δ9-tetrahydrocannabinol (Δ9-THC). Methods The effects of BFC on the hyperpolarization of wild type AtT20 cells, or AtT20 cells stably expressing human CB1- or CB2- receptors, were studied using a fluorescent assay of membrane potential. The effect of BFC on CB1- and CB2-mediated inhibition of forskolin-stimulated adenylyl cyclase (AC) activation was measured using a BRET assay of cAMP levels in HEK 293 cells stably expressing human CB1 or CB2. Results BFC did not activate CB1 or CB2 receptors, or affect the hyperpolarization of wild type AtT20 cells produced by somatostatin. BFC (1 µM) did not affect the hyperpolarization of AtT20-CB1 or AtT20-CB2 cells produced by CP55940 or Δ9-THC. BFC (1 µM) did not affect the inhibition of forskolin-stimulated AC activity by CP55940 in HEK 293 cells expressing CB1 or CB2. BFC (1 µM) also failed to affect the desensitization of CB1 and CB2 signaling produced by prolonged (30 min) application of CP55940 or Δ9-THC to AtT20 cells. Discussion BFC is not a cannabinoid receptor agonist, and appeared not to affect cannabinoid receptor activation. Our data suggests there is no pharmacodynamic rationale for mixing BFC with synthetic cannabinoids; however, it does not speak to whether BFC may affect synthetic cannabinoid metabolism or biodistribution. The reasons underlying the mixing of BFC with synthetic cannabinoids are unknown, and it remains to be established whether the “contamination” was deliberate or accidental. However, the consequences for people who ingested the mixture were often serious, and sometimes fatal, but this seems unlikely to be due to BFC action at cannabinoid receptors.
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Affiliation(s)
- Shivani Sachdev
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Rochelle Boyd
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia.,Cancer Research Unit, Children's Medical Research Institute, Sydney, NSW, Australia
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, and Centre for Brain Research School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Marina Santiago
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
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15
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Santiago M, Sachdev S, Arnold JC, McGregor IS, Connor M. Absence of Entourage: Terpenoids Commonly Found in Cannabis sativa Do Not Modulate the Functional Activity of Δ 9-THC at Human CB 1 and CB 2 Receptors. Cannabis Cannabinoid Res 2019; 4:165-176. [PMID: 31559333 PMCID: PMC6757242 DOI: 10.1089/can.2019.0016] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Introduction: Compounds present in Cannabis sativa such as phytocannabinoids and terpenoids may act in concert to elicit therapeutic effects. Cannabinoids such as Δ9-tetrahydrocannabinol (Δ9-THC) directly activate cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2); however, it is not known if terpenoids present in Cannabis also affect cannabinoid receptor signaling. Therefore, we examined six common terpenoids alone, and in combination with cannabinoid receptor agonists, on CB1 and CB2 signaling in vitro. Materials and Methods: Potassium channel activity in AtT20 FlpIn cells transfected with human CB1 or CB2 receptors was measured in real time using FLIPR® membrane potential dye in a FlexStation 3 plate reader. Terpenoids were tested individually and in combination for periods up to 30 min. Endogenous somatostatin receptors served as a control for direct effects of drugs on potassium channels. Results: α-Pinene, β-pinene, β-caryophyllene, linalool, limonene, and β-myrcene (up to 30-100 μM) did not change membrane potential in AtT20 cells expressing CB1 or CB2, or affect the response to a maximally effective concentration of the synthetic cannabinoid CP55,940. The presence of individual or a combination of terpenoids did not affect the hyperpolarization produced by Δ9-THC (10 μM): (CB1: control, 59%±7%; with terpenoids (10 μM each) 55%±4%; CB2: Δ9-THC 16%±5%, with terpenoids (10 μM each) 17%±4%). To investigate possible effect on desensitization of CB1 responses, all six terpenoids were added together with Δ9-THC and signaling measured continuously over 30 min. Terpenoids did not affect desensitization, after 30 min the control hyperpolarization recovered by 63%±6% in the presence of the terpenoids recovery was 61%±5%. Discussion: None of the six of the most common terpenoids in Cannabis directly activated CB1 or CB2, or modulated the signaling of the phytocannabinoid agonist Δ9-THC. These results suggest that if a phytocannabinoid-terpenoid entourage effect exists, it is not at the CB1 or CB2 receptor level. It remains possible that terpenoids activate CB1 and CB2 signaling pathways that do not involve potassium channels; however, it seems more likely that they may act at different molecular target(s) in the neuronal circuits important for the behavioral effect of Cannabis.
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Affiliation(s)
- Marina Santiago
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Shivani Sachdev
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Jonathon C. Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
- Discipline of Pharmacology, The University of Sydney, Sydney, New South Wales, Australia
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
- School of Psychology, The University of Sydney, Sydney, New South Wales, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
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16
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Feelders RA, Newell-Price J, Pivonello R, Nieman LK, Hofland LJ, Lacroix A. Advances in the medical treatment of Cushing's syndrome. Lancet Diabetes Endocrinol 2019; 7:300-312. [PMID: 30033041 DOI: 10.1016/s2213-8587(18)30155-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/30/2018] [Accepted: 05/08/2018] [Indexed: 01/05/2023]
Abstract
Cushing's syndrome is associated with multisystem morbidity and, when suboptimally treated, increased mortality. Medical therapy is an option for patients if surgery is not successful and can be classified into pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. In the last decade there have been new developments in each drug category. Targeting dopamine and somatostatin receptors on corticotroph adenomas with cabergoline or pasireotide, or both, controls cortisol production in up to 40% of patients. Potential new targets in corticotroph adenomas include the epidermal growth factor receptor, cyclin-dependent kinases, and heat shock protein 90. Osilodrostat and levoketoconazole are new inhibitors of steroidogenesis and are currently being evaluated in multicentre trials. CORT125134 is a new selective glucocorticoid receptor antagonist under investigation. We summarise the drug therapies for various forms of Cushing's syndrome and focus on emerging drugs and drug targets that have the potential for new and effective tailor-made pharmacotherapy for patients with Cushing's syndrome.
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Affiliation(s)
- Richard A Feelders
- Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Centre, Rotterdam, Netherlands.
| | - John Newell-Price
- Academic Unit of Endocrinology, University of Sheffield, Sheffield, UK
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università Federico II di Napoli, Naples, Italy
| | - Lynnette K Nieman
- Eunice Kennedy Shriver National Institute of Diabetes and Kidney Disease, National Institutes of Health, Bethesda, MD, USA
| | - Leo J Hofland
- Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Centre, Rotterdam, Netherlands
| | - Andre Lacroix
- Division of Endocrinology, Department of Medicine and Research Centre, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, QC, Canada
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17
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Mann A, Moulédous L, Froment C, O'Neill PR, Dasgupta P, Günther T, Brunori G, Kieffer BL, Toll L, Bruchas MR, Zaveri NT, Schulz S. Agonist-selective NOP receptor phosphorylation correlates in vitro and in vivo and reveals differential post-activation signaling by chemically diverse agonists. Sci Signal 2019; 12:12/574/eaau8072. [PMID: 30914485 DOI: 10.1126/scisignal.aau8072] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Agonists of the nociceptin/orphanin FQ opioid peptide (NOP) receptor, a member of the opioid receptor family, are under active investigation as novel analgesics, but their modes of signaling are less well characterized than those of other members of the opioid receptor family. Therefore, we investigated whether different NOP receptor ligands showed differential signaling or functional selectivity at the NOP receptor. Using newly developed phosphosite-specific antibodies to the NOP receptor, we found that agonist-induced NOP receptor phosphorylation occurred primarily at four carboxyl-terminal serine (Ser) and threonine (Thr) residues, namely, Ser346, Ser351, Thr362, and Ser363, and proceeded with a temporal hierarchy, with Ser346 as the first site of phosphorylation. G protein-coupled receptor kinases 2 and 3 (GRK2/3) cooperated during agonist-induced phosphorylation, which, in turn, facilitated NOP receptor desensitization and internalization. A comparison of structurally distinct NOP receptor agonists revealed dissociation in functional efficacies between G protein-dependent signaling and receptor phosphorylation. Furthermore, in NOP-eGFP and NOP-eYFP mice, NOP receptor agonists induced multisite phosphorylation and internalization in a dose-dependent and agonist-selective manner that could be blocked by specific antagonists. Our study provides new tools to study ligand-activated NOP receptor signaling in vitro and in vivo. Differential agonist-selective NOP receptor phosphorylation by chemically diverse NOP receptor agonists suggests that differential signaling by NOP receptor agonists may play a role in NOP receptor ligand pharmacology.
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Affiliation(s)
- Anika Mann
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, Jena 07747, Germany.
| | - Lionel Moulédous
- Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, CNRS, UPS, 31062 Toulouse Cedex 09, France
| | - Carine Froment
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Patrick R O'Neill
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pooja Dasgupta
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, Jena 07747, Germany
| | - Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, Jena 07747, Germany
| | - Gloria Brunori
- Biomedical Science Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Brigitte L Kieffer
- Douglas Research Center, Department of Psychiatry, Faculty of Medicine, McGill University, Montreal, QC H3A 1A1, Canada
| | - Lawrence Toll
- Biomedical Science Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Michael R Bruchas
- Center for the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, Jena 07747, Germany.
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18
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Günther T, Tulipano G, Dournaud P, Bousquet C, Csaba Z, Kreienkamp HJ, Lupp A, Korbonits M, Castaño JP, Wester HJ, Culler M, Melmed S, Schulz S. International Union of Basic and Clinical Pharmacology. CV. Somatostatin Receptors: Structure, Function, Ligands, and New Nomenclature. Pharmacol Rev 2019; 70:763-835. [PMID: 30232095 PMCID: PMC6148080 DOI: 10.1124/pr.117.015388] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Somatostatin, also known as somatotropin-release inhibitory factor, is a cyclopeptide that exerts potent inhibitory actions on hormone secretion and neuronal excitability. Its physiologic functions are mediated by five G protein-coupled receptors (GPCRs) called somatostatin receptor (SST)1-5. These five receptors share common structural features and signaling mechanisms but differ in their cellular and subcellular localization and mode of regulation. SST2 and SST5 receptors have evolved as primary targets for pharmacological treatment of pituitary adenomas and neuroendocrine tumors. In addition, SST2 is a prototypical GPCR for the development of peptide-based radiopharmaceuticals for diagnostic and therapeutic interventions. This review article summarizes findings published in the last 25 years on the physiology, pharmacology, and clinical applications related to SSTs. We also discuss potential future developments and propose a new nomenclature.
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Affiliation(s)
- Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Giovanni Tulipano
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Pascal Dournaud
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Corinne Bousquet
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Zsolt Csaba
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Kreienkamp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Amelie Lupp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Márta Korbonits
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Justo P Castaño
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Wester
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Michael Culler
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Shlomo Melmed
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
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19
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Heblinski M, Bladen C, Connor M. Regulation of heterologously expressed 5-HT 1B receptors coupling to potassium channels in AtT-20 cells. Br J Pharmacol 2018; 176:451-465. [PMID: 30447001 DOI: 10.1111/bph.14547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/08/2018] [Accepted: 10/17/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE 5-HT1B receptors are widely expressed GPCRs and a target of triptans, the most commonly prescribed anti-migraine drugs. There is very limited information about the acute, agonist-induced regulation of 5-HT1B receptor signalling and so we sought to characterize this in a neuron-like system. EXPERIMENTAL APPROACH Epitope-tagged human 5-HT1B receptors were expressed in mouse AtT20 cells. 5-HT1B receptor signalling was assessed using whole-cell patch-clamp recordings of endogenous G protein-gated inwardly rectified potassium (GIRK) channels, and receptor localization measured using immunofluorescence. KEY RESULTS 5-HT (EC50 65 nM) and sumatriptan (EC50 165 nM) activated GIRK channels in AtT20 cells expressing 5-HT1B receptors. Continuous application of both 5-HT (EC50 120 nM) and sumatriptan (EC50 280 nM) produced profound desensitization of 5-HT1B receptor signalling within a few minutes. Complete recovery from desensitization was observed after 10 min. Both 5-HT and sumatriptan induced significant heterologous desensitization of SRIF (somatostatin)-activated GIRK currents, with the 5-HT-induced heterologous desensitization being blocked by the protein kinase inhibitor staurosporine. Both agonists induced modest 5-HT1B receptor internalization, with a time course much slower than receptor desensitization. CONCLUSIONS AND IMPLICATIONS In AtT-20 cells, 5-HT1B receptors undergo rapid and reversible desensitization at concentrations of agonist similar to those required to activate the receptor. Desensitization is incomplete, and the continued signalling of the receptor in the presence of the agonist may lead to cellular adaptations. Finally, 5-HT1B receptor activation causes significant heterologous desensitization, which may lead to a reduced effectiveness of unrelated drugs in vivo.
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Affiliation(s)
- Marika Heblinski
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Christopher Bladen
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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Rodriguez M, Frost JA, Schonbrunn A. Real-Time Signaling Assays Demonstrate Somatostatin Agonist Bias for Ion Channel Regulation in Somatotroph Tumor Cells. J Endocr Soc 2018; 2:779-793. [PMID: 30151433 PMCID: PMC6106105 DOI: 10.1210/js.2018-00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/11/2018] [Indexed: 11/19/2022] Open
Abstract
Acromegaly is a neuroendocrine disorder caused by excess secretion of GH by somatotroph tumor cells. It is often treated with somatostatin receptor (SSTR) 2 agonists, which suppress GH secretion. SOM230 is a somatostatin analogue that targets multiple SSTRs and was recently approved for patients with treatment-resistant acromegaly. Previous reports indicate that SOM230 may function as a biased agonist, suggesting that its ability to selectively activate SSTR-dependent signaling events may contribute to its therapeutic efficacy. To better understand how SOM230 modulates Sstr2A function, which is the most commonly expressed SSTR in somatotrophs, we used real-time assays to study SOM230-dependent signaling in rat pituitary tumor cells. We observed that SOM230 suppressed cAMP production in a Gαi-dependent manner, similar to conventional Sstr2A agonists. However, it did not cause receptor internalization as would be expected for an Sstr2A agonist. Surprisingly, SOM230 did not cause membrane hyperpolarization, which is an important mechanism by which Sstr2a activation suppresses intracellular calcium (Ca2+) accumulation and GH secretion. In fact, SOM230 inhibited the ability of conventional somatostatin analogues to control membrane potential. However, SOM230 still inhibited intracellular Ca2+ accumulation in a novel, Gβγ-dependent manner. These studies show that SOM230 exhibits strong agonist bias in regulating signaling pathways downstream of Sstr2A that control GH secretion.
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Affiliation(s)
- Melissa Rodriguez
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Jeffrey A Frost
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Agnes Schonbrunn
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
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21
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Andersen HK, Piroli GG, Walsh KB. A real time screening assay for cannabinoid CB1 receptor-mediated signaling. J Pharmacol Toxicol Methods 2018; 94:44-49. [PMID: 29730318 DOI: 10.1016/j.vascn.2018.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 01/25/2023]
Abstract
The cannabinoid CB1 receptor is expressed throughout the central nervous system where it functions to regulate neurotransmitter release and synaptic plasticity. While the CB1 receptor has been identified as a target for both natural and synthetic cannabinoids, the specific downstream signaling pathways activated by these various ligands have not been fully described. In this study, we developed a real-time membrane potential fluorescent assay for cannabinoids using pituitary AtT20 cells that endogenously express G protein-gated inward rectifier K+ (GIRK) channels and were stably transfected with the CB1 receptor using a recombinant lentivirus. In whole-cell patch clamp experiments application of the cannabinoid agonist WIN 55,212-2 to AtT20 cells expressing the CB1 receptor (AtT20/CB1) activated GIRK currents that were blocked by BaCl2. WIN 55,212-2 activation of the GIRK channels was associated with a time- and concentration-dependent (EC50 = 309 nM) hyperpolarization of the membrane potential in the AtT20/CB1 cells when monitored using a fluorescent membrane potential-sensitive dye. The WIN 55,212-2-induced fluorescent signal was inhibited by pretreatment of the cells with either the GIRK channel blocker tertiapin-Q or the CB1 receptor antagonist SR141716. The cannabinoids displayed a response of WIN 55,212-2 ≈ anandamide (AEA) > CP 55,940 > Δ9-tetrahydrocannabinol (THC) when maximal concentrations of the four ligands were tested in the assay. Thus, the AtT20/CB1 cell fluorescent assay will provide a straightforward and efficient methodology for examining cannabinoid-stimulated Gi signaling.
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Affiliation(s)
- Haley K Andersen
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, United States
| | - Gerardo G Piroli
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, United States
| | - Kenneth B Walsh
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, United States.
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22
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Paragliola RM, Salvatori R. Novel Somatostatin Receptor Ligands Therapies for Acromegaly. Front Endocrinol (Lausanne) 2018; 9:78. [PMID: 29563895 PMCID: PMC5845985 DOI: 10.3389/fendo.2018.00078] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/20/2018] [Indexed: 12/21/2022] Open
Abstract
Surgery is considered the treatment of choice in acromegaly, but patients with persistent disease after surgery or in whom surgery cannot be considered require medical therapy. Somatostatin receptor ligands (SRLs) octreotide (OCT), lanreotide, and the more recently approved pasireotide, characterized by a broader receptor ligand binding profile, are considered the mainstay in the medical management of acromegaly. However, in the attempt to offer a more efficacious and better tolerated medical approach, recent research has been aimed to override some limitations related to the use of currently approved drugs and novel SRLs therapies, with potential attractive features, have been proposed. These include both new formulation of older molecules and new molecules. Novel OCT formulations are aimed in particular to improve patients' compliance and to reduce injection discomfort. They include an investigational ready-to-use subcutaneous depot OCT formulation (CAM2029), delivered via prefilled syringes and oral OCT that uses a "transient permeability enhancer" technology, which allows for OCT oral absorption. Another new delivery system is a long-lasting OCT implant (VP-003), which provide stable doses of OCT throughout a period of several months. Finally, a new SRL DG3173 (somatoprim) seems to be more selective for GH secretion, suggesting possible advantages in the presence of hyperglycemia or diabetes. How much these innovations will actually be beneficial to acromegaly patients in real clinical practice remains to be seen.
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Affiliation(s)
| | - Roberto Salvatori
- Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, Pituitary Center Johns Hopkins University School of Medicine, Baltimore, MD, United States
- *Correspondence: Roberto Salvatori,
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23
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Walsh KB, Gay EA, Blough BE, Geurkink DW. N-(2-methoxyphenyl) benzenesulfonamide, a novel regulator of neuronal G protein-gated inward rectifier K + channels. Eur J Pharmacol 2017; 815:233-240. [PMID: 28935562 DOI: 10.1016/j.ejphar.2017.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 02/07/2023]
Abstract
G protein-gated inward rectifier K+ (GIRK) channels are members of the super-family of proteins known as inward rectifier K+ (Kir) channels and are expressed throughout the peripheral and central nervous systems. Neuronal GIRK channels are the downstream targets of a number of neuromodulators including opioids, somatostatin, dopamine and cannabinoids. Previous studies have demonstrated that the ATP-sensitive K+ channel, another member of the Kir channel family, is regulated by sulfonamide drugs. Therefore, to determine if sulfonamides also modulate GIRK channels, we screened a library of arylsulfonamide compounds using a GIRK channel fluorescent assay that utilized pituitary AtT20 cells expressing GIRK channels along with the somatostatin type-2 and -5 receptors. Enhancement of the GIRK channel fluorescent signal by one compound, N-(2-methoxyphenyl) benzenesulfonamide (MPBS), was dependent on the activation of the channel by somatostatin. In whole-cell patch clamp experiments, application of MPBS both shifted the somatostatin concentration-response curve (EC50 = 3.5nM [control] vs.1.0nM [MPBS]) for GIRK channel activation and increased the maximum GIRK current measured with 100nM somatostatin. However, GIRK channel activation was not observed when MPBS was applied to the cells in the absence of somatostatin. While the MPBS structural analog 4-fluoro-N-(2-methoxyphenyl) benzenesulfonamide also augmented the somatostatin-induced GIRK fluorescent signal, no increase in the signal was observed with the sulfonamides tolbutamide, sulfapyridine and celecoxib. In conclusion, MPBS represents a novel prototypic GPCR-dependent regulator of neuronal GIRK channels.
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Affiliation(s)
- Kenneth B Walsh
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, United States.
| | - Elaine A Gay
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, United States
| | - Bruce E Blough
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, United States
| | - David W Geurkink
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, School of Medicine, Columbia, SC, United States
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24
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Vázquez López JL, Schild L, Günther T, Schulz S, Neurath H, Becker A. The effects of kratom on restraint-stress-induced analgesia and its mechanisms of action. JOURNAL OF ETHNOPHARMACOLOGY 2017; 205:178-185. [PMID: 28501425 DOI: 10.1016/j.jep.2017.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Mitragyna speciosa and its extracts are called kratom (dried leaves, extract). They contain several alkaloids with an affinity for different opioid receptors. They are used in traditional medicine for the treatment of different diseases, as a substitute by opiate addicts, and to mitigate opioid withdrawal symptoms. Apart from their medical properties, they are used to enhance physical endurance and as a means of overcoming stress. PURPOSE The aim of this study was to determine the mechanisms underlying the effects of kratom on restraint-stress-induced analgesia which occurs during or following exposure to a stressful or fearful stimulus. METHODS To gain further insights into the action of kratom on stress, we conducted experiments using restraint stress as a test system and stress-induced analgesia as a test parameter. Using transgenic mu opioid-receptor (MOR) deficient mice, we studied the involvement of this receptor type. We used nor-binaltorphimine (BNT), an antagonist at kappa opioid receptors (KOR), to study functions of this type of receptor. Membrane potential assay was also employed to measure the intrinsic activity of kratom in comparison to U50,488, a highly selective kappa agonist. RESULTS Treatment with kratom diminished stress-induced analgesia in wildtype and MOR knockout animals. Pretreatment of MOR deficient mice with BNT resulted in similar effects. In comparison to U50,488, kratom exhibited negligible intrinsic activity at KOR alone. CONCLUSIONS The results suggest that the use of kratom as a pharmacological tool to mitigate withdrawal symptoms is related to its action on KOR.
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Affiliation(s)
- José Luis Vázquez López
- Otto-von-Guericke University, Faculty of Medicine, Institute of Pharmacology and Toxicology, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Lorenz Schild
- Otto-von-Guericke-University, Faculty of Medicine, Department of Pathobiochemistry, Leipziger Strasse 44, 39120 Magdeburg, Germany
| | - Thomas Günther
- Friedrich Schiller University Jena, Jena University Hospital, Institute of Pharmacology and Toxicology, Drackendorfer Str. 1, 07747 Jena, Germany
| | - Stefan Schulz
- Friedrich Schiller University Jena, Jena University Hospital, Institute of Pharmacology and Toxicology, Drackendorfer Str. 1, 07747 Jena, Germany
| | - Hartmud Neurath
- Center of Pharmacology and Toxicology, Georg August University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Axel Becker
- Otto-von-Guericke University, Faculty of Medicine, Institute of Pharmacology and Toxicology, Leipziger Str. 44, 39120 Magdeburg, Germany.
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Lehmann A, Kliewer A, Günther T, Nagel F, Schulz S. Identification of Phosphorylation Sites Regulating sst3 Somatostatin Receptor Trafficking. Mol Endocrinol 2016; 30:645-59. [PMID: 27101376 DOI: 10.1210/me.2015-1244] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The human somatostatin receptor 3 (sst3) is expressed in about 50% of all neuroendocrine tumors and hence a promising target for multireceptor somatostatin analogs. The sst3 receptor is unique among ssts in that it exhibits a very long intracellular C-terminal tail containing a huge number of potential phosphate acceptor sites. Consequently, our knowledge about the functional role of the C-terminal tail in sst3 receptor regulation is very limited. Here, we have generated a series of phosphorylation-deficient mutants that enabled us to determine crucial sites for its agonist-induced β-arrestin mobilization, internalization, and down-regulation. Based on this information, we generated phosphosite-specific antibodies for C-terminal Ser(337)/Thr(341), Thr(348), and Ser(361) that enabled us to investigate the temporal patterns of sst3 phosphorylation and dephosphorylation. We found that the endogenous ligand somatostatin induced a rapid and robust phosphorylation that was completely blocked by the sst3 antagonist NVP-ACQ090. The stable somatostatin analogs pasireotide and octreotide promoted clearly less phosphorylation compared with somatostatin. We also show that sst3 phosphorylation occurred within seconds to minutes, whereas dephosphorylation of the sst3 receptor occurred at a considerable slower rate. In addition, we also identified G protein-coupled receptor kinases 2 and 3 and protein phosphatase 1α and 1β as key regulators of sst3 phosphorylation and dephosphorylation, respectively. Thus, we here define the C-terminal phosphorylation motif of the human sst3 receptor that regulates its agonist-promoted phosphorylation, β-arrestin recruitment, and internalization of this clinically relevant receptor.
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Affiliation(s)
- Andreas Lehmann
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Andrea Kliewer
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Falko Nagel
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, D-07747 Jena, Germany
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