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Gerlach L, Beyer ASL, Kaemmerer D, Sänger J, Evert K, Schulz S, Lupp A. Expression of G protein-coupled receptor GPR19 in normal and neoplastic human tissues. Sci Rep 2023; 13:18993. [PMID: 37923782 PMCID: PMC10624815 DOI: 10.1038/s41598-023-46395-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 10/31/2023] [Indexed: 11/06/2023] Open
Abstract
Little is known about the expression of the orphan G protein-coupled receptor GPR19 at the protein level. Therefore, we developed a rabbit antibody, targeting human GPR19. After verification of the antibody specificity using GPR19-expressing cell lines and a GPR19-specific siRNA, the antibody was used for immunohistochemical staining of a variety of formalin-fixed, paraffin-embedded normal and neoplastic human tissue samples. In normal tissues, GPR19 expression was detected in a distinct cell population within the cortex, in single cells of the pancreatic islets, in intestinal ganglia, gastric chief cells, and in endocrine cells of the bronchial tract, the gastrointestinal tract, and the prostate. Among the 30 different tumour entities investigated, strong GPR19 expression was found in adenocarcinomas, typical and atypical carcinoids of the lung, and small cell lung cancer. To a lesser extent, the receptor was also present in large cell neuroendocrine carcinomas of the lung, medullary thyroid carcinomas, parathyroid adenomas, pheochromocytomas, and a subpopulation of pancreatic neuroendocrine neoplasms. In lung tumours, a negative correlation with the expression of the proliferation marker Ki-67 and a positive interrelationship with patient survival was observed. Overall, our results indicate that in adenocarcinomas and neuroendocrine tumours of the lung GPR19 may serve as a suitable diagnostic or therapeutic target.
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Affiliation(s)
- Lorena Gerlach
- Institute of Pharmacology and Toxicology, Jena University Hospital, Jena, Germany
| | | | - Daniel Kaemmerer
- Department of General and Visceral Surgery, Zentralklinik Bad Berka, Bad Berka, Germany
| | - Jörg Sänger
- Laboratory of Pathology and Cytology Bad Berka, Bad Berka, Germany
| | - Katja Evert
- Department of Pathology, University of Regensburg, Regensburg, Germany
- Institute of Pathology, University Medicine of Greifswald, Greifswald, Germany
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Jena, Germany
| | - Amelie Lupp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Jena, Germany.
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany.
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2
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Wang P, Lv L, Li H, Wang CY, Zhou J. Opportunities and challenges in drug discovery targeting the orphan receptor GPR12. Drug Discov Today 2023; 28:103698. [PMID: 37422169 DOI: 10.1016/j.drudis.2023.103698] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/26/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023]
Abstract
G-protein-coupled receptor 12 (GPR12) is a brain-specific expression orphan G-protein-coupled receptor (oGPCR) that regulates various physiological processes. It is an emerging therapeutic target for central nervous system (CNS) disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), attention deficit hyperactivity disorder (ADHD), and schizophrenia, as well as other human diseases, such as cancer, obesity, and metabolic disorders. GPR12 remains a less extensively investigated oGPCR, particularly in terms of its biological functions, signaling pathways, and ligand discovery. The discovery of drug-like small-molecule modulators to probe the brain functions of GPR12 or to act as a potential drug candidates, as well as the identification of reliable biomarkers, are vital to elucidate the roles of this receptor in various human diseases and develop novel target-based therapeutics.
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Affiliation(s)
- Pingyuan Wang
- Key Laboratory of Evolution and Marine Biodiversity Ministry of Education, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
| | - Ling Lv
- Key Laboratory of Evolution and Marine Biodiversity Ministry of Education, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Haoran Li
- Key Laboratory of Evolution and Marine Biodiversity Ministry of Education, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Chang-Yun Wang
- Key Laboratory of Evolution and Marine Biodiversity Ministry of Education, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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3
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Maudsley S, Schrauwen C, Harputluoğlu İ, Walter D, Leysen H, McDonald P. GPR19 Coordinates Multiple Molecular Aspects of Stress Responses Associated with the Aging Process. Int J Mol Sci 2023; 24:ijms24108499. [PMID: 37239845 DOI: 10.3390/ijms24108499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/15/2023] [Accepted: 04/15/2023] [Indexed: 05/28/2023] Open
Abstract
G protein-coupled receptors (GPCRs) play a significant role in controlling biological paradigms such as aging and aging-related disease. We have previously identified receptor signaling systems that are specifically associated with controlling molecular pathologies associated with the aging process. Here, we have identified a pseudo-orphan GPCR, G protein-coupled receptor 19 (GPR19), that is sensitive to many molecular aspects of the aging process. Through an in-depth molecular investigation process that involved proteomic, molecular biological, and advanced informatic experimentation, this study found that the functionality of GPR19 is specifically linked to sensory, protective, and remedial signaling systems associated with aging-related pathology. This study suggests that the activity of this receptor may play a role in mitigating the effects of aging-related pathology by promoting protective and remedial signaling systems. GPR19 expression variation demonstrates variability in the molecular activity in this larger process. At low expression levels in HEK293 cells, GPR19 expression regulates signaling paradigms linked with stress responses and metabolic responses to these. At higher expression levels, GPR19 expression co-regulates systems involved in sensing and repairing DNA damage, while at the highest levels of GPR19 expression, a functional link to processes of cellular senescence is seen. In this manner, GPR19 may function as a coordinator of aging-associated metabolic dysfunction, stress response, DNA integrity management, and eventual senescence.
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Affiliation(s)
- Stuart Maudsley
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Claudia Schrauwen
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - İrem Harputluoğlu
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Deborah Walter
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Hanne Leysen
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Patricia McDonald
- Moffitt Cancer Center, Department of Metabolism & Physiology, 12902 Magnolia Drive, Tampa, FL 33612, USA
- Lexicon Pharmaceuticals Inc. Research & Development, 2445 Technology Forest, The Woodlands, TX 77381, USA
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4
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Mushala BAS, Xie B, Sipula IJ, Stoner MW, Thapa D, Manning JR, Bugga P, Vandevender AM, Jurczak MJ, Scott I. G-protein coupled receptor 19 (GPR19) knockout mice display sex-dependent metabolic dysfunction. Sci Rep 2023; 13:6134. [PMID: 37061564 PMCID: PMC10105709 DOI: 10.1038/s41598-023-33308-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 04/10/2023] [Indexed: 04/17/2023] Open
Abstract
G-protein coupled receptors (GPCRs) mediate signal transduction from the cellular surface to intracellular metabolic pathways. While the function of many GPCRs has been delineated previously, a significant number require further characterization to elucidate their cellular function. G-protein coupled receptor 19 (GPR19) is a poorly characterized class A GPCR which has been implicated in the regulation of circadian rhythm, tumor metastasis, and mitochondrial homeostasis. In this report, we use a novel knockout (KO) mouse model to examine the role of GPR19 in whole-body metabolic regulation. We show that loss of GPR19 promotes increased energy expenditure and decreased activity in both male and female mice. However, only male GPR19 KO mice display glucose intolerance in response to a high fat diet. Loss of GPR19 expression in male mice, but not female mice, resulted in diet-induced hepatomegaly, which was associated with decreased expression of key fatty acid oxidation genes in male GPR19 KO livers. Overall, our data suggest that loss of GPR19 impacts whole-body energy metabolism in diet-induced obese mice in a sex-dependent manner.
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Affiliation(s)
- Bellina A S Mushala
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Bingxian Xie
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Ian J Sipula
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Michael W Stoner
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Dharendra Thapa
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Exercise Physiology, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - Janet R Manning
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Paramesha Bugga
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Amber M Vandevender
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Michael J Jurczak
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Iain Scott
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, BST E1259, 200 Lothrop Street, Pittsburgh, PA, 15261, USA.
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
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5
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Wong T, Gao W, Chen G, Qiu C, He G, Ye F, Wu Z, Zeng Z, Du Y. Cryo-EM structure of orphan G protein-coupled receptor GPR21. MedComm (Beijing) 2023; 4:e205. [PMID: 36721851 PMCID: PMC9877262 DOI: 10.1002/mco2.205] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/13/2022] [Accepted: 12/18/2022] [Indexed: 01/27/2023] Open
Abstract
GPR21 belongs to class A orphan G protein-coupled receptor (GPCR). The endogenous ligands for human GPR21 remain unidentified. GPR21 expression is associated with developing type 2 diabetes (T2DM), a multifactorial metabolic disease caused by pancreatic β-cell dysfunction, decreasing insulin production, insulin resistance, and obesity. Animal studies suggested that GPR21 is a potential therapeutic target for T2DM treatment. The underlying mechanisms leading to GPR21 self-activation remain unknown. In our co-expression analysis, we noted that GPR21 could also form a stable complex with an unreported Gα protein subtype, Gαs. To gain further insights into the structural mechanisms of GPR21 activation, we employed cryo-electron microscopy (cryo-EM) and single-particle analysis to resolve the high-resolution structure of GPR21-Gαs complexes. The clear electron density map of the GPR21-Gαs provided direct evidence that GPR21 could couple to Gαs protein at physiological conditions. Thus, GPR21 might mediate previously unexplored pathways in normal or pathological conditions, which warrants further investigation. Structure-guided mutagenesis and biochemical analysis revealed that extracellular loop 2 (ECL2) of GPR21 is essential for the receptor transducing intracellular signal via cAMP. Together, the new structure data reveal a novel signaling cascade of human GPR21 mediated by ECL2 and provide fundamental information for future structure-based drug development.
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Affiliation(s)
- Thian‐Sze Wong
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
- School of MedicineTsinghua UniversityBeijingChina
| | - Wei Gao
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
- Innovation Center for AI and Drug DiscoveryEast China Normal UniversityShanghaiChina
| | - Geng Chen
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
| | - Chen Qiu
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
| | - Guodong He
- School of MedicineTsinghua UniversityBeijingChina
| | - Fang Ye
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
| | - Zhangsong Wu
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
| | - Zicheng Zeng
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
| | - Yang Du
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug, Discovery and Development, School of Medicinethe Chinese University of Hong KongShenzhenGuangdongChina
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6
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Maudsley S, Walter D, Schrauwen C, Van Loon N, Harputluoğlu İ, Lenaerts J, McDonald P. Intersection of the Orphan G Protein-Coupled Receptor, GPR19, with the Aging Process. Int J Mol Sci 2022; 23:ijms232113598. [PMID: 36362387 PMCID: PMC9653598 DOI: 10.3390/ijms232113598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
G protein-coupled receptors (GPCRs) represent one of the most functionally diverse classes of transmembrane proteins. GPCRs and their associated signaling systems have been linked to nearly every physiological process. They also constitute nearly 40% of the current pharmacopeia as direct targets of remedial therapies. Hence, their place as a functional nexus in the interface between physiological and pathophysiological processes suggests that GPCRs may play a central role in the generation of nearly all types of human disease. Perhaps one mechanism through which GPCRs can mediate this pivotal function is through the control of the molecular aging process. It is now appreciated that, indeed, many human disorders/diseases are induced by GPCR signaling processes linked to pathological aging. Here we discuss one such novel member of the GPCR family, GPR19, that may represent an important new target for novel remedial strategies for the aging process. The molecular signaling pathways (metabolic control, circadian rhythm regulation and stress responsiveness) associated with this recently characterized receptor suggest an important role in aging-related disease etiology.
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Affiliation(s)
- Stuart Maudsley
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
- Correspondence:
| | - Deborah Walter
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Claudia Schrauwen
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Nore Van Loon
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - İrem Harputluoğlu
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
| | - Julia Lenaerts
- Receptor Biology Lab, University of Antwerp, 2610 Antwerpen, Belgium
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7
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Wang L, Yang D, Zhang Y, Jiao Y. GPR12 Inhibits Apoptosis in Epithelial Ovarian Cancer via the Activation of ERK1/2 Signaling. Front Oncol 2022; 12:932689. [PMID: 35903681 PMCID: PMC9316591 DOI: 10.3389/fonc.2022.932689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Epithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancies in women worldwide. G protein–coupled receptor 12 (GPR12) is a member of G protein–coupled receptors (GPCRs) and plays an important role in the regulation of cell proliferation and survival. However, its role in EOC is underappreciated. In this study, we found that GPR12 is highly expressed in the EOC tissues and can be an ideal biomarker to predict the prognosis of patients with EOC. GPR12 knockdown obviously inhibits the proliferation of EOC cells by inducing cellular apoptosis in vitro and in vivo. Meanwhile, bioinformatic analysis showed that the inhibitory effect of GPR12 knockdown on the cell viability is closely related with Extracellular signal-regulated kinases 1/2 (ERK1/2) pathway, which has been confirmed by the fact that the activity of ERK1/2 pathway has been significantly blocked in the GPR12 knockdown cells. LM22B-10, ERK1/2 pathway activator, could reverse the inhibited proliferation caused by GPR12 knockdown in the EOC cells. Our findings suggest that GPR12 is involved in the EOC process and is a potential therapeutic target for EOC.
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Affiliation(s)
- Lu Wang
- Department of General Medicine, Liaoning Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, China
| | - Da Yang
- Department of Urology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yao Zhang
- Department of Gynecology and Obstetrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yisheng Jiao
- Department of Gynecology and Obstetrics, Shengjing Hospital of China Medical University, Shenyang, China
- *Correspondence: Yisheng Jiao,
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8
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G protein–coupled receptor 21 in macrophages: An in vitro study. Eur J Pharmacol 2022; 926:175018. [DOI: 10.1016/j.ejphar.2022.175018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 04/27/2022] [Accepted: 05/04/2022] [Indexed: 11/20/2022]
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9
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Metabolic Syndrome: Updates on Pathophysiology and Management in 2021. Int J Mol Sci 2022; 23:ijms23020786. [PMID: 35054972 PMCID: PMC8775991 DOI: 10.3390/ijms23020786] [Citation(s) in RCA: 414] [Impact Index Per Article: 207.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 12/18/2022] Open
Abstract
Metabolic syndrome (MetS) forms a cluster of metabolic dysregulations including insulin resistance, atherogenic dyslipidemia, central obesity, and hypertension. The pathogenesis of MetS encompasses multiple genetic and acquired entities that fall under the umbrella of insulin resistance and chronic low-grade inflammation. If left untreated, MetS is significantly associated with an increased risk of developing diabetes and cardiovascular diseases (CVDs). Given that CVDs constitute by far the leading cause of morbidity and mortality worldwide, it has become essential to investigate the role played by MetS in this context to reduce the heavy burden of the disease. As such, and while MetS relatively constitutes a novel clinical entity, the extent of research about the disease has been exponentially growing in the past few decades. However, many aspects of this clinical entity are still not completely understood, and many questions remain unanswered to date. In this review, we provide a historical background and highlight the epidemiology of MetS. We also discuss the current and latest knowledge about the histopathology and pathophysiology of the disease. Finally, we summarize the most recent updates about the management and the prevention of this clinical syndrome.
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10
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Kinsella GK, Cannito S, Bordano V, Stephens JC, Rosa AC, Miglio G, Guaschino V, Iannaccone V, Findlay JBC, Benetti E. GPR21 Inhibition Increases Glucose-Uptake in HepG2 Cells. Int J Mol Sci 2021; 22:ijms221910784. [PMID: 34639123 PMCID: PMC8509304 DOI: 10.3390/ijms221910784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/24/2021] [Accepted: 09/29/2021] [Indexed: 02/08/2023] Open
Abstract
GPR21 is a constitutively active, orphan, G-protein-coupled receptor, with in vivo studies suggesting its involvement in the modulation of insulin sensitivity. However, its precise contribution is not fully understood. As the liver is both a major target of insulin signalling and critically involved in glucose metabolism, the aim of this study was to examine the role of GPR21 in the regulation of glucose uptake and production in human hepatocytes. In particular, HepG2 cells, which express GPR21, were adopted as cellular models. Compared with untreated cells, a significant increase in glucose uptake was measured in cells treated with siRNA to downregulate GPR21 expression or with the GPR21-inverse agonist, GRA2. Consistently, a significantly higher membrane translocation of GLUT-2 was measured under these conditions. These effects were accompanied by an increased ratio of phAKT(Ser473)/tot-AKT and phGSK-3β(Ser9)/tot-GSK-3β, thus indicating a marked activation of the insulin signalling pathway. Moreover, a significant reduction in ERK activation was observed with GPR21 inhibition. Collectively, these results indicate that GPR21 mediates the negative effects on glucose uptake by the liver cells. In addition, they suggest that the pharmacological inhibition of GPR21 could be a novel strategy to improve glucose homeostasis and counteract hepatic insulin resistance.
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Affiliation(s)
- Gemma K. Kinsella
- School of Food Sciences and Environmental Health, Technological University Dublin, Grangegorman, D07 ADY7 Dublin, Ireland;
| | - Stefania Cannito
- Department of Clinical and Biological Sciences, University of Turin, 10125 Turin, Italy;
| | - Valentina Bordano
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
| | - John C. Stephens
- Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland;
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Arianna C. Rosa
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
| | - Gianluca Miglio
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
| | - Valeria Guaschino
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
| | - Valeria Iannaccone
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
| | - John B. C. Findlay
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland;
- School of Biomedical Sciences, University of Leeds, LS2 9JT Leeds, UK
| | - Elisa Benetti
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy; (V.B.); (A.C.R.); (G.M.); (V.G.); (V.I.)
- Correspondence: ; Tel.: +39-0116707137
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11
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Schihada H, Shekhani R, Schulte G. Quantitative assessment of constitutive G protein-coupled receptor activity with BRET-based G protein biosensors. Sci Signal 2021; 14:eabf1653. [PMID: 34516756 DOI: 10.1126/scisignal.abf1653] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Hannes Schihada
- Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, Solnavägen 9, SE-17165 Stockholm, Sweden
| | - Rawan Shekhani
- Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, Solnavägen 9, SE-17165 Stockholm, Sweden
| | - Gunnar Schulte
- Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, Solnavägen 9, SE-17165 Stockholm, Sweden
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12
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Romero-Nava R, García N, Aguayo-Cerón KA, Sánchez Muñoz F, Huang F, Hong E, Villafaña S. Modifications in GPR21 and GPR82 genes expression as a consequence of metabolic syndrome etiology. J Recept Signal Transduct Res 2020; 41:38-44. [PMID: 32583711 DOI: 10.1080/10799893.2020.1784228] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Metabolic syndrome (MS) has been related with alterations in expression levels of orphan G protein coupled receptors (GPCRs) such as GPR21 and GPR82, which could be involved in some of the elements that characterizes the metabolic syndrome. The aim of this work was to evaluate changes in GPR21 and GPR82 receptors expression in two models of metabolic syndrome: one genetic (Zucker rats), and the other based on a diet (70% fructose for 9 weeks). GPR21 and GPR82 gene expressions were evaluated in brain, heart, aorta, liver and kidney by RT-qPCR. Rats with a high fructose diet, as well as obese Zucker rats, showed initial stages of pancreatic damage and alterations in some biochemical parameters related to the model consistent with the classification of MS. GPR21 and GPR82 receptors expressed in all tissues. The expression of GPR21 decreased in heart, aorta and kidney, but in liver the expression was different: decreased in diet model and increased in genetic model. In contrast, GPR82 expression depended of tissue and metabolic syndrome model. The results highlight the possible role of GPR21 and GPR82 receptors in the development MS. We conclude that the expression of GPR21 and GPR82 in different tissues is related with MS and depend of the origin of the syndrome, so they could be a therapeutic target for that syndrome.
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Affiliation(s)
- Rodrigo Romero-Nava
- Laboratorio de Señalización Intracelular, Sección de Estudios de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, Ciudad de México, México.,Laboratorio de Investigación en Farmacología, Hospital Infantil de México Federico Gómez (HIMFG), Ciudad de México, México
| | - Noemí García
- Escuela Nacional de Medicina, Tecnológico de Monterrey, Monterrey, México
| | - Karla Aidee Aguayo-Cerón
- Laboratorio de Señalización Intracelular, Sección de Estudios de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, Ciudad de México, México
| | - Fausto Sánchez Muñoz
- Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
| | - Fengyang Huang
- Laboratorio de Investigación en Farmacología, Hospital Infantil de México Federico Gómez (HIMFG), Ciudad de México, México
| | - Enrique Hong
- Departamento de Neurofarmacobiología, Centro de Investigación y de Estudios Avanzados, Ciudad de México, México
| | - Santiago Villafaña
- Laboratorio de Señalización Intracelular, Sección de Estudios de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, Ciudad de México, México
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13
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Watkins LR, Orlandi C. Orphan G Protein Coupled Receptors in Affective Disorders. Genes (Basel) 2020; 11:E694. [PMID: 32599826 PMCID: PMC7349732 DOI: 10.3390/genes11060694] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022] Open
Abstract
G protein coupled receptors (GPCRs) are the main mediators of signal transduction in the central nervous system. Therefore, it is not surprising that many GPCRs have long been investigated for their role in the development of anxiety and mood disorders, as well as in the mechanism of action of antidepressant therapies. Importantly, the endogenous ligands for a large group of GPCRs have not yet been identified and are therefore known as orphan GPCRs (oGPCRs). Nonetheless, growing evidence from animal studies, together with genome wide association studies (GWAS) and post-mortem transcriptomic analysis in patients, pointed at many oGPCRs as potential pharmacological targets. Among these discoveries, we summarize in this review how emotional behaviors are modulated by the following oGPCRs: ADGRB2 (BAI2), ADGRG1 (GPR56), GPR3, GPR26, GPR37, GPR50, GPR52, GPR61, GPR62, GPR88, GPR135, GPR158, and GPRC5B.
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Affiliation(s)
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA;
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14
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Allende G, Chávez-Reyes J, Guerrero-Alba R, Vázquez-León P, Marichal-Cancino BA. Advances in Neurobiology and Pharmacology of GPR12. Front Pharmacol 2020; 11:628. [PMID: 32457622 PMCID: PMC7226366 DOI: 10.3389/fphar.2020.00628] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/21/2020] [Indexed: 01/19/2023] Open
Abstract
GPR12 is a G protein-coupled orphan receptor genetically related to type 1 and type 2 cannabinoid receptors (CB1 and CB2) which are ancient proteins expressed all over the body. Both cannabinoid receptors, but especially CB1, are involved in neurodevelopment and cognitive processes such as learning, memory, brain reward, coordination, etc. GPR12 shares with CB1 that both are mainly expressed into the brain. Regrettably, very little is known about physiology of GPR12. Concerning its pharmacology, GPR12 seems to be endogenously activated by the lysophospholipids sphingosine-1-phosphate (S1P) and sphingosyl-phosphorylcholine (SPC). Exogenously, GPR12 is a target for the phytocannabinoid cannabidiol (CBD). Functionally, GPR12 seems to be related to neurogenesis and neural inflammation, but its relationship with cognitive functions remains to be characterized. Although GPR12 was initially suggested to be a cannabinoid receptor, it does not meet the five criteria proposed in 2010 by the International Union of Basic and Clinical Pharmacology (IUPHAR). In this review, we analyze all the direct available information in PubMed database about expression, function, and pharmacology of this receptor in central nervous system (CNS) trying to provide a broad overview of its current and prospective neurophysiology. Moreover, in this mini-review we highlight the need to produce more relevant data about the functions of GPR12 in CNS. Hence, this work should motivate further research in this field.
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Affiliation(s)
- Gonzalo Allende
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Aguascalientes, Mexico
| | - Jesús Chávez-Reyes
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Aguascalientes, Mexico
| | - Raquel Guerrero-Alba
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Aguascalientes, Mexico
| | - Priscila Vázquez-León
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Aguascalientes, Mexico
| | - Bruno A Marichal-Cancino
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Aguascalientes, Mexico
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15
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Laun AS, Shrader SH, Brown KJ, Song ZH. GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol. Acta Pharmacol Sin 2019; 40:300-308. [PMID: 29941868 PMCID: PMC6460361 DOI: 10.1038/s41401-018-0031-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/17/2018] [Indexed: 01/08/2023] Open
Abstract
The G protein-coupled receptors 3, 6, and 12 (GPR3, GPR6, and GPR12) comprise a family of closely related orphan receptors with no confirmed endogenous ligands. These receptors are constitutively active and capable of signaling through G protein-mediated and non-G protein-mediated mechanisms. These orphan receptors have previously been reported to play important roles in many normal physiological functions and to be involved in a variety of pathological conditions. Although they are orphans, GPR3, GPR6, and GPR12 are phylogenetically most closely related to the cannabinoid receptors. Using β-arrestin2 recruitment and cAMP accumulation assays, we recently found that the nonpsychoactive phytocannabinoid cannabidiol (CBD) is an inverse agonist for GPR3, GPR6, and GPR12. This discovery highlights these orphan receptors as potential new molecular targets for CBD, provides novel mechanisms of action, and suggests new therapeutic uses of CBD for illnesses such as Alzheimer's disease, Parkinson's disease, cancer, and infertility. Furthermore, identification of CBD as a new inverse agonist for GPR3, GPR6, and GPR12 provides the initial chemical scaffolds upon which potent and efficacious agents acting on these receptors can be developed, with the goal of developing chemical tools for studying these orphan receptors and ultimately new therapeutic agents.
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Affiliation(s)
- Alyssa S Laun
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Sarah H Shrader
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Kevin J Brown
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Zhao-Hui Song
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA.
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16
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Riddy DM, Delerive P, Summers RJ, Sexton PM, Langmead CJ. G Protein–Coupled Receptors Targeting Insulin Resistance, Obesity, and Type 2 Diabetes Mellitus. Pharmacol Rev 2017; 70:39-67. [DOI: 10.1124/pr.117.014373] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/13/2017] [Indexed: 12/18/2022] Open
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17
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Rao A, Herr DR. G protein-coupled receptor GPR19 regulates E-cadherin expression and invasion of breast cancer cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1318-1327. [PMID: 28476646 DOI: 10.1016/j.bbamcr.2017.05.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 04/04/2017] [Accepted: 05/01/2017] [Indexed: 12/16/2022]
Abstract
Dysregulation of G protein-coupled receptors (GPCRs) is known to be involved in the pathogenesis of a variety of diseases, including cancer initiation and progression. Within this family, approximately 140 GPCRs have no known endogenous ligands and these "orphan" GPCRs remain poorly characterized. The orphan GPCR GPR19 was identified and cloned 2 decades ago, but relatively little is known about its physio-pathological relevance. We observed its expression to be elevated in breast cancers and therefore sought to investigate its potential role in breast cancer pathology. In this work, we show that overexpression of GPR19 drives mesenchymal-like breast cancer cells to adopt an epithelial-like phenotype, as demonstrated by the upregulation in E-cadherin expression and changes in functional behavior. We confirm a previous report that a peptide, adropin, is an endogenous ligand for GPR19. We further show that adropin-mediated activation of GPR19 activates the MAPK/ERK1/2 pathway, which is essential for the observed upregulation in E-cadherin and accompanying phenotypic changes. The recapitulation of epithelial characteristics at the secondary tumor sites is now understood to be an essential step in the colonization process. Taken together our work shows for the first time that GPR19 plays a potential role in metastasis by promoting the mesenchymal-epithelial transition (MET) through the ERK/MAPK pathway, thus facilitating colonization of metastatic breast tumor cells.
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Affiliation(s)
- Angad Rao
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Deron R Herr
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore; Department of Biology, San Diego State University, San Diego, CA, USA.
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18
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Romero-Nava R, Zhou DS, García N, Ruiz-Hernández A, Si YC, Sánchez-Muñoz F, Huang F, Hong E, Villafaña S. Evidence of alterations in the expression of orphan receptors GPR26 and GPR39 due to the etiology of the metabolic syndrome. J Recept Signal Transduct Res 2017; 37:422-429. [DOI: 10.1080/10799893.2017.1298133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Rodrigo Romero-Nava
- Escuela Superior de Medicina del Instituto Politécnico Nacional, Laboratorio de Señalización Intracelular, Sección de Posgrado, Mexico
| | - De-Shan Zhou
- Department of Histology and Embryology, Capital Medical University, Beijing, China
| | - Noemí García
- Escuela Nacional de Medicina, Tecnológico de Monterrey, Monterrey, NL, Mexico
- Centro de Investigación Básica y de Transferencia, Hospital Zambrano Hellio, Garza García, NL, Mexico
| | - Armando Ruiz-Hernández
- Escuela Superior de Medicina del Instituto Politécnico Nacional, Laboratorio de Señalización Intracelular, Sección de Posgrado, Mexico
| | - Yin-Chu Si
- Department of Anatomy, Beijing University of Chinese Medicine, Beijing, China
| | - Fausto Sánchez-Muñoz
- Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico
| | - Fengyang Huang
- Departamento de Farmacología y Toxicología, Hospital Infantil de México Federico Gómez (HIMFG), México, Mexico
| | - Enrique Hong
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados, Ciudad de México, México
| | - Santiago Villafaña
- Escuela Superior de Medicina del Instituto Politécnico Nacional, Laboratorio de Señalización Intracelular, Sección de Posgrado, Mexico
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19
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Regulating the effects of GPR21, a novel target for type 2 diabetes. Sci Rep 2016; 6:27002. [PMID: 27243589 PMCID: PMC4886680 DOI: 10.1038/srep27002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/12/2016] [Indexed: 01/06/2023] Open
Abstract
Type 2 diabetes is a chronic metabolic disorder primarily caused by insulin resistance to which obesity is a major contributor. Expression levels of an orphan G protein-coupled receptor (GPCR), GPR21, demonstrated a trend towards a significant increase in the epididymal fat pads of wild type high fat high sugar (HFHS)-fed mice. To gain further insight into the potential role this novel target may play in the development of obesity-associated type 2 diabetes, the signalling capabilities of the receptor were investigated. Overexpression studies in HEK293T cells revealed GPR21 to be a constitutively active receptor, which couples to Gαq type G proteins leading to the activation of mitogen activated protein kinases (MAPKs). Overexpression of GPR21 in vitro also markedly attenuated insulin signalling. Interestingly, the effect of GPR21 on the MAPKs and insulin signalling was reduced in the presence of serum, inferring the possibility of a native inhibitory ligand. Homology modelling and ligand docking studies led to the identification of a novel compound that inhibited GPR21 activity. Its effects offer potential as an anti-diabetic pharmacological strategy as it was found to counteract the influence of GPR21 on the insulin signalling pathway.
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20
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Wang J, Pan Z, Baribault H, Chui D, Gundel C, Véniant M. GPR21 KO mice demonstrate no resistance to high fat diet induced obesity or improved glucose tolerance. F1000Res 2016; 5:136. [PMID: 27081476 PMCID: PMC4813635 DOI: 10.12688/f1000research.7822.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/13/2016] [Indexed: 12/24/2022] Open
Abstract
Gpr21 KO mice generated with
Gpr21 KO ES cells obtained from Deltagen showed improved glucose tolerance and insulin sensitivity when fed a high fat diet. Further mRNA expression analysis revealed changes in
Rabgap1 levels and raised the possibility that
Rabgap1 gene may have been modified. To assess this hypothesis a new
Gpr21 KO mouse line using TALENS technology was generated.
Gpr21 gene deletion was confirmed by PCR and
Gpr21 and
Rabgap1 mRNA expression levels were determined by RT-PCR. The newly generated
Gpr21 KO mice when fed a normal or high fat diet chow did not maintain their improved metabolic phenotype. In conclusion,
Rabgap1 disturbance mRNA expression levels may have contributed to the phenotype of the originally designed
Gpr21 KO mice.
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Affiliation(s)
- Jinghong Wang
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Zheng Pan
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Helene Baribault
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Danny Chui
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Caroline Gundel
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - Murielle Véniant
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
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21
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Im DS. Intercellular Lipid Mediators and GPCR Drug Discovery. Biomol Ther (Seoul) 2014; 21:411-22. [PMID: 24404331 PMCID: PMC3879912 DOI: 10.4062/biomolther.2013.080] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 01/08/2023] Open
Abstract
G-protein-coupled receptors (GPCR) are the largest superfamily of receptors responsible for signaling between cells and tissues, and because they play important physiological roles in homeostasis, they are major drug targets. New technologies have been developed for the identification of new ligands, new GPCR functions, and for drug discovery purposes. In particular, intercellular lipid mediators, such as, lysophosphatidic acid and sphingosine 1-phosphate have attracted much attention for drug discovery and this has resulted in the development of fingolimod (FTY-720) and AM095. The discovery of new intercellular lipid mediators and their GPCRs are discussed from the perspective of drug development. Lipid GPCRs for lysophospholipids, including lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylcholine, free fatty acids, fatty acid derivatives, and other lipid mediators are reviewed.
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Affiliation(s)
- Dong-Soon Im
- Molecular Inflammation Research Center for Aging Intervention (MRCA) and College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
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22
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Kastner S, Voss T, Keuerleber S, Glöckel C, Freissmuth M, Sommergruber W. Expression of G protein-coupled receptor 19 in human lung cancer cells is triggered by entry into S-phase and supports G(2)-M cell-cycle progression. Mol Cancer Res 2012; 10:1343-58. [PMID: 22912338 DOI: 10.1158/1541-7786.mcr-12-0139] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It has long been known that G protein-coupled receptors (GPCR) are subject to illegitimate expression in tumor cells. Presumably, hijacking the normal physiologic functions of GPCRs contributes to all biologic capabilities acquired during tumorigenesis. Here, we searched for GPCRs that were expressed in lung cancer: the mRNA encoding orphan G protein-coupled receptor 19 (GPR19) was found frequently overexpressed in tissue samples obtained from patients with small cell lung cancer. Several observations indicate that overexpression of Gpr19 confers a specific advantage to lung cancer cells by accelerating transition through the cell-cycle. (i) Knockdown of Gpr19 mRNA by RNA interference reduced cell growth of human lung cancer cell lines. (ii) Cell-cycle progression through G(2)-M-phase was impaired in cells transfected with siRNAs directed against Gpr19 and this was associated with increased protein levels of cyclin B1 and phosphorylated histone H3. (iii) The expression levels of Gpr19 mRNA varied along the cell-cycle with a peak observed in S-phase. (iv) The putative control of Gpr19 expression by E2F transcription factors was verified by chromatin immunoprecipitation: antibodies directed against E2F-1 to -4 allowed for the recovery of the Gpr19 promoter. (v) Removal of E2F binding sites in the Gpr19 promoter diminished the expression of a luciferase reporter. (vi) E2f and Gpr19 expression correlated in lung cancer patient samples. To the best of knowledge, this is the first example of a GPCR showing cell-cycle-specific mRNA expression. Our data also validate GPR19 as a candidate target when overexpressed in lung cancer.
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Affiliation(s)
- Stefan Kastner
- Boehringer Ingelheim RCV GmbH & Co KG, Department of Lead Discovery, Dr. Boehringer-Gasse 5-11, 1121 Vienna, Austria
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23
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Metabolic parameters and emotionality are little affected in G-protein coupled receptor 12 (Gpr12) mutant mice. PLoS One 2012; 7:e42395. [PMID: 22879962 PMCID: PMC3413656 DOI: 10.1371/journal.pone.0042395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 07/05/2012] [Indexed: 11/19/2022] Open
Abstract
Background G-protein coupled receptors (GPR) bear the potential to serve as yet unidentified drug targets for psychiatric and metabolic disorders. GPR12 is of major interest given its putative role in metabolic function and its unique brain distribution, which suggests a role in emotionality and affect. We tested Gpr12 deficient mice in a series of metabolic and behavioural tests and subjected them to a well-established high-fat diet feeding protocol. Methodology/Principal Findings Comparing the mutant mice with wild type littermates, no significant differences were seen in body weight, fatness or weight gain induced by a high-fat diet. The Gpr12 mutant mice displayed a modest but significant lowering of energy expenditure and a trend to lower food intake on a chow diet, but no other metabolic parameters, including respiratory rate, were altered. No emotionality-related behaviours (assessed by light-dark box, tail suspension, and open field tests) were affected by the Gpr12 gene mutation. Conclusions/Significance Studying metabolic and emotionality parameters in Gpr12 mutant mice did not reveal a major phenotypic impact of the gene mutation. Compared to previous results showing a metabolic phenotype in Gpr12 mice with a mixed 129 and C57Bl6 background, we suggest that a more pure C57Bl/6 background due to further backcrossing might have reduced the phenotypic penetrance.
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24
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Chen D, Liu X, Zhang W, Shi Y. Targeted inactivation of GPR26 leads to hyperphagia and adiposity by activating AMPK in the hypothalamus. PLoS One 2012; 7:e40764. [PMID: 22815809 PMCID: PMC3398048 DOI: 10.1371/journal.pone.0040764] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 06/12/2012] [Indexed: 11/22/2022] Open
Abstract
G-protein coupled receptor 26 (GPR26) is a brain-specific orphan GPCR with high expression in the brain region that controls satiety. Depletion of GPR26 has been shown to increase fat storage in C. elegans, whereas GPR26 deficiency in the hypothalamus is associated with high genetic susceptibility to the onset of obesity in mice. However, the metabolic function of GPR26 in mammals remains elusive. Herein, we investigated a role of GPR26 in regulating energy homeostasis by generating mice with targeted deletion of the GPR26 gene. We show that GPR26 deficiency causes hyperphagia and hypometabolism, leading to early onset of diet-induced obesity. Accordingly, GPR26 deficiency also caused metabolic complications commonly associated with obesity, including glucose intolerance, hyperinsulinemia, and dyslipidemia. Moreover, consistent with hyperphagia in GPR26 null mice, GPR26 deficiency significantly increased hypothalamic activity of AMPK, a key signaling event that stimulates appetite. In further support of a regulatory role of GPR26 in satiety, GPR26 knockout mice also demonstrate hypersensitivity to treatment of rimonabant, an endocannabinoid receptor-1 antagonist commonly used to treat obesity by suppressing appetite in humans. Together, these findings identified a key role of GPR26 as a central regulator of energy homeostasis though modulation of hypothalamic AMPK activation.
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Affiliation(s)
- Daohong Chen
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Xiaolei Liu
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
- Department of Pharmacology, School of Pharmaceutical Sciences Central South University, Changsha, China
| | - Weiping Zhang
- Department of Pathophysiology, Second Military Medical University Shanghai, China
| | - Yuguang Shi
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
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25
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Osborn O, Oh DY, McNelis J, Sanchez-Alavez M, Talukdar S, Lu M, Li P, Thiede L, Morinaga H, Kim JJ, Heinrichsdorff J, Nalbandian S, Ofrecio JM, Scadeng M, Schenk S, Hadcock J, Bartfai T, Olefsky JM. G protein-coupled receptor 21 deletion improves insulin sensitivity in diet-induced obese mice. J Clin Invest 2012; 122:2444-53. [PMID: 22653059 DOI: 10.1172/jci61953] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 04/24/2012] [Indexed: 02/06/2023] Open
Abstract
Obesity-induced inflammation is a key component of systemic insulin resistance, which is a hallmark of type 2 diabetes. A major driver of this inflammation/insulin resistance syndrome is the accumulation of proinflammatory macrophages in adipose tissue and liver. We found that the orphan GPCR Gpr21 was highly expressed in the hypothalamus and macrophages of mice and that whole-body KO of this receptor led to a robust improvement in glucose tolerance and systemic insulin sensitivity and a modest lean phenotype. The improvement in insulin sensitivity in the high-fat diet-fed (HFD-fed) Gpr21 KO mouse was traced to a marked reduction in tissue inflammation caused by decreased chemotaxis of Gpr21 KO macrophages into adipose tissue and liver. Furthermore, mice lacking macrophage expression of Gpr21 were protected from HFD-induced inflammation and displayed improved insulin sensitivity. Results of in vitro chemotaxis studies in human monocytes suggested that the defect in chemotaxis observed ex vivo and in vivo in mice is also translatable to humans. Cumulatively, our data indicate that GPR21 has a critical function in coordinating macrophage proinflammatory activity in the context of obesity-induced insulin resistance.
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Affiliation(s)
- Olivia Osborn
- Division of Endocrinology and Metabolism, Department of Medicine, UCSD, La Jolla, CA, USA
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26
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Somma G, Alger HM, McGuire RM, Kretlow JD, Ruiz FR, Yatsenko SA, Stankiewicz P, Harrison W, Funk E, Bergamaschi A, Oghalai JS, Mikos AG, Overbeek PA, Pereira FA. Head bobber: an insertional mutation causes inner ear defects, hyperactive circling, and deafness. J Assoc Res Otolaryngol 2012; 13:335-49. [PMID: 22383091 DOI: 10.1007/s10162-012-0316-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2010] [Accepted: 02/06/2012] [Indexed: 12/12/2022] Open
Abstract
The head bobber transgenic mouse line, produced by pronuclear integration, exhibits repetitive head tilting, circling behavior, and severe hearing loss. Transmitted as an autosomal recessive trait, the homozygote has vestibular and cochlea inner ear defects. The space between the semicircular canals is enclosed within the otic capsule creating a vacuous chamber with remnants of the semicircular canals, associated cristae, and vestibular organs. A poorly developed stria vascularis and endolymphatic duct is likely the cause for Reissner's membrane to collapse post-natally onto the organ of Corti in the cochlea. Molecular analyses identified a single integration of ~3 tandemly repeated copies of the transgene, a short duplicated segment of chromosome X and a 648 kb deletion of chromosome 7(F3). The three known genes (Gpr26, Cpxm2, and Chst15) in the deleted region are conserved in mammals and expressed in the wild-type inner ear during vestibular and cochlea development but are absent in homozygous mutant ears. We propose that genes critical for inner ear patterning and differentiation are lost at the head bobber locus and are candidate genes for human deafness and vestibular disorders.
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Affiliation(s)
- Giuseppina Somma
- Huffington Center on Aging, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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27
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Gardner J, Wu S, Ling L, Danao J, Li Y, Yeh WC, Tian H, Baribault H. G-protein-coupled receptor GPR21 knockout mice display improved glucose tolerance and increased insulin response. Biochem Biophys Res Commun 2012; 418:1-5. [DOI: 10.1016/j.bbrc.2011.11.117] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 11/22/2011] [Indexed: 11/27/2022]
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28
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Reinhart PH, Kaltenbach LS, Essrich C, Dunn DE, Eudailey JA, DeMarco CT, Turmel GJ, Whaley JC, Wood A, Cho S, Lo DC. Identification of anti-inflammatory targets for Huntington's disease using a brain slice-based screening assay. Neurobiol Dis 2011; 43:248-56. [PMID: 21458569 DOI: 10.1016/j.nbd.2011.03.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 02/02/2011] [Accepted: 03/23/2011] [Indexed: 10/18/2022] Open
Abstract
Huntington's disease (HD) is a late-onset, neurodegenerative disease for which there are currently no cures nor disease-modifying treatments. Here we report the identification of several potential anti-inflammatory targets for HD using an ex vivo model of HD that involves the acute transfection of human mutant huntingtin-based constructs into rat brain slices. This model recapitulates key components of the human disease, including the formation of intracellular huntingtin protein (HTT)-containing inclusions and the progressive neurodegeneration of striatal neurons-both occurring within the native tissue context of these neurons. Using this "high-throughput biology" screening platform, we conducted a hypothesis-neutral screen of a collection of drug-like compounds which identified several anti-inflammatory targets that provided neuroprotection against HTT fragment-induced neurodegeneration. The nature of these targets provide further support for non-cell autonomous mechanisms mediating significant aspects of neuropathogenesis induced by mutant HTT fragment proteins.
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Affiliation(s)
- Peter H Reinhart
- Discovery Neuroscience, Wyeth Research, Princeton, NJ 08543, USA
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29
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Im DS. New intercellular lipid mediators and their GPCRs: An update. Prostaglandins Other Lipid Mediat 2009; 89:53-6. [DOI: 10.1016/j.prostaglandins.2009.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 01/24/2009] [Accepted: 01/25/2009] [Indexed: 01/08/2023]
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30
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Swift JL, Burger MC, Massotte D, Dahms TES, Cramb DT. Two-photon excitation fluorescence cross-correlation assay for ligand-receptor binding: cell membrane nanopatches containing the human micro-opioid receptor. Anal Chem 2007; 79:6783-91. [PMID: 17683166 DOI: 10.1021/ac0709495] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Current ligand-receptor binding assays for G-protein coupled receptors cannot directly measure the system's dissociation constant, Kd, without purification of the receptor protein. Accurately measured Kd's are essential in the development of a molecular level understanding of ligand-receptor interactions critical in rational drug design. Here we report the introduction of two-photon excitation fluorescence cross-correlation spectroscopy (TPE-FCCS) to the direct analysis of ligand-receptor interactions of the human micro opioid receptor (hMOR) for both agonists and antagonists. We have developed the use of fluorescently distinct, dye-labeled hMOR-containing cell membrane nanopatches ( approximately 100-nm radius) and ligands, respectively, for this assay. We show that the output from TPE-FCCS data sets can be converted to the conventional Hill format, which provides Kd and the number of active receptors per nanopatch. When ligands are labeled with quantum dots, this assay can detect binding with ligand concentrations in the subnanomolar regime. Interestingly, conjugation to a bulky quantum dot did not adversely affect the binding propensity of the hMOR pentapeptide ligand, Leu-enkephalin.
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Affiliation(s)
- Jody L Swift
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
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31
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Tanaka S, Ishii K, Kasai K, Yoon SO, Saeki Y. Neural expression of G protein-coupled receptors GPR3, GPR6, and GPR12 up-regulates cyclic AMP levels and promotes neurite outgrowth. J Biol Chem 2007; 282:10506-15. [PMID: 17284443 DOI: 10.1074/jbc.m700911200] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclic AMP regulates multiple neuronal functions, including neurite outgrowth and axonal regeneration. GPR3, GPR6, and GPR12 make up a family of constitutively active G protein-coupled receptors (GPCRs) that share greater than 50% identity and 65% similarity at the amino acid level. They are highly expressed in the central nervous system, and their expression in various cell lines results in constitutive stimulation of cAMP production. When the constitutively active GPCRs were overexpressed in rat cerebellar granule neurons in culture, the transfected neurons exhibited significantly enhanced neurite outgrowth and overcame growth inhibition caused by myelin-associated glycoprotein. GPR12-mediated neurite outgrowth was the most prominent and was shown to depend on G(s) and cAMP-dependent protein kinase. Moreover, the GPR12-mediated rescue from myelin-associated glycoprotein inhibition was attributable to cAMP-dependent protein kinase-mediated inhibition of the small GTPase, RhoA. Among the three receptors, GPR3 was revealed to be enriched in the developing rat cerebellar granule neurons. When the endogenous GPR3 was knocked down, significant reduction of neurite growth was observed, which was reversed by expression of either GPR3 or GPR12. Taken together, our results indicate that expression of the constitutively active GPCRs up-regulates cAMP production in neurons, stimulates neurite outgrowth, and counteracts myelin inhibition. Further characterization of the GPCRs in developing and injured mammalian neurons should provide insights into how basal cAMP levels are regulated in neurons and could establish a firm scientific foundation for applying receptor biology to treatment of various neurological disorders.
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Affiliation(s)
- Shigeru Tanaka
- Dardinger Laboratory for Neuro-oncology and Neurosciences, Department of Neurological Surgery, the Ohio State University, Columbus, Ohio 43210, USA
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32
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Bjursell M, Gerdin AK, Jönsson M, Surve VV, Svensson L, Huang XF, Törnell J, Bohlooly-Y M. G protein-coupled receptor 12 deficiency results in dyslipidemia and obesity in mice. Biochem Biophys Res Commun 2006; 348:359-66. [PMID: 16887097 DOI: 10.1016/j.bbrc.2006.07.090] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Accepted: 07/04/2006] [Indexed: 10/24/2022]
Abstract
Obesity has been proposed to be a result of an imbalance in the physiological system that controls and maintains the body energy homeostasis. Several G-protein coupled receptors (GPCRs) are involved in the regulation of energy homeostasis. To investigate the importance of GPCR12, mice deficient of this receptor (GPCR12 KO) were studied regarding metabolism. Expression of GPCR12 was found primarily in the limbic and sensory systems, indicating its possible involvement in motivation, emotion together with various autonomic functions, and sensory information processing. GPCR12 KO mice were found to have higher body weight, body fat mass, lower respiratory exchange ratio (RER), hepatic steatosis, and were dyslipidemic. Neither food intake nor energy in faeces was affected in the GPCR12 KO mice. However, lower energy expenditure was found in the GPCR12 KO mice, which may explain the obesity. In conclusion, GPCR12 is considered important for the energy balance since GPCR12 KO mice develop obesity and have lower energy expenditure. This may be important for future drugs that target this receptor.
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Affiliation(s)
- Mikael Bjursell
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Göteborg University, Sweden
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33
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Sela-Abramovich S, Edry I, Galiani D, Nevo N, Dekel N. Disruption of gap junctional communication within the ovarian follicle induces oocyte maturation. Endocrinology 2006; 147:2280-6. [PMID: 16439460 DOI: 10.1210/en.2005-1011] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Meiotically arrested mammalian oocytes are stimulated to resume meiosis by LH. This response, which can be reversed by elevation of intraoocyte cAMP levels, is associated with interruption of gap junctional communication (GJC) within the ovarian follicle. In the present study, we examined the hypothesis that disruption of GJC within the ovarian follicle is sufficient for induction of oocyte maturation. For this purpose, we incubated rat follicle-enclosed oocytes with carbenoxolone (CBX), a known blocker of gap junctions. We found that this selective disruptor of GJC promoted maturation of almost all the follicle-enclosed oocytes after 5 h of incubation; this response was also obtained by a transient (2 h) exposure to this agent. CBX-induced oocyte maturation was accompanied by a substantial decrease in intraoocyte concentrations of cAMP that was not associated with elevated activity of type 3A phosphodiesterase (PDE3A). The effect of CBX on reinitiation of meiosis was blocked by isobutylmethylxanthine, a phosphodiesterase inhibitor. Unlike LH, CBX did not activate MAPK in the follicular cells, and inhibition of the MAPK signaling pathway by means of UO126 did not prevent the resumption of meiosis. Injection of CBX into the ovarian bursa of intact animals stimulated maturation in 30% of the oocytes, whereas no maturation was observed in the contralateral ovary injected with PBS. We conclude that, because experimentally induced breakdown of communication within the ovarian follicle is associated with a drop in intraoocyte cAMP concentrations and results in resumption of meiosis, this could be the physiological mechanism employed by LH to stimulate oocyte maturation.
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34
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Freudzon L, Norris RP, Hand AR, Tanaka S, Saeki Y, Jones TLZ, Rasenick MM, Berlot CH, Mehlmann LM, Jaffe LA. Regulation of meiotic prophase arrest in mouse oocytes by GPR3, a constitutive activator of the Gs G protein. ACTA ACUST UNITED AC 2006; 171:255-65. [PMID: 16247026 PMCID: PMC2171177 DOI: 10.1083/jcb.200506194] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The arrest of meiotic prophase in mouse oocytes within antral follicles requires the G protein G(s) and an orphan member of the G protein-coupled receptor family, GPR3. To determine whether GPR3 activates G(s), the localization of Galpha(s) in follicle-enclosed oocytes from Gpr3(+/+) and Gpr3(-/-) mice was compared by using immunofluorescence and Galpha(s)GFP. GPR3 decreased the ratio of Galpha(s) in the oocyte plasma membrane versus the cytoplasm and also decreased the amount of Galpha(s) in the oocyte. Both of these properties indicate that GPR3 activates G(s). The follicle cells around the oocyte are also necessary to keep the oocyte in prophase, suggesting that they might activate GPR3. However, GPR3-dependent G(s) activity was similar in follicle-enclosed and follicle-free oocytes. Thus, the maintenance of prophase arrest depends on the constitutive activity of GPR3 in the oocyte, and the follicle cell signal acts by a means other than increasing GPR3 activity.
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Affiliation(s)
- Leon Freudzon
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06032
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35
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Bond RA, Ijzerman AP. Recent developments in constitutive receptor activity and inverse agonism, and their potential for GPCR drug discovery. Trends Pharmacol Sci 2006; 27:92-6. [PMID: 16406086 DOI: 10.1016/j.tips.2005.12.007] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 11/21/2005] [Accepted: 12/15/2005] [Indexed: 11/18/2022]
Abstract
The concept of constitutively active G-protein-coupled receptors is now firmly rooted in receptor pharmacology. Many independent research groups have contributed to its acceptance since its introduction by Costa and Herz in 1989. This concept necessitated a revised ligand classification, and a new category of inverse agonists was introduced alongside existing agonist and antagonist ligands. Initially, it was hoped that new therapeutic modalities would become available. However, the drug industry has not adopted inverse agonism as a design criterion and instead accepted that some compounds emerge as (neutral) antagonists in compound screening, whereas other compounds possess inverse agonistic activity. In this article, we summarize aspects of the impact of constitutive activity on the drug-discovery process: for example, its use in orphan receptor assays, its link with pharmacogenetics and genomics, and its relevance for currently marketed drugs.
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Affiliation(s)
- Richard A Bond
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, 4800 Calhoun, Houston, TX 77204-5037, USA
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36
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Oosterom J, van Doornmalen EJP, Lobregt S, Blomenröhr M, Zaman GJR. High-Throughput Screening Using β-Lactamase Reporter-Gene Technology for Identification of Low-Molecular-Weight Antagonists of the Human Gonadotropin Releasing Hormone Receptor. Assay Drug Dev Technol 2005; 3:143-54. [PMID: 15871689 DOI: 10.1089/adt.2005.3.143] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
G-protein coupled receptors (GPCRs) signal via G-proteins to intracellular second messengers. Assays that link transcription of a detectable reporter to promoters that are activated by such signaling cascades are highly sensitive and allow screening for compounds that either activate or inactivate a GPCR of interest. This study describes the development and performance of an antagonistic screen on the human gonadotropin releasing hormone receptor (GnRH-R). Compounds (245,000) were tested in a high-throughput screen using a Chinese hamster ovary cell line stably expressing the human GnRH-R and the Ca2+ sensitive reporter nuclear factor activated in T-cells/ activator protein-1-beta-lactamase. In total, 4,160 active compounds were identified. Colored and toxic compounds, as well as dust and compound aggregates, have been depicted as artifacts. To deselect non-target hits, several follow-up assays, including luminescent and fluorescent Ca2+ mobilization assays and radioligand binding, were developed for the GnRH-R. These assays were validated using peptide and low-molecular-weight GnRH-R reference compounds before hits from screening were also profiled in these assays. For several reference compounds the use of different assay technologies resulted in a poor correlation of potency values. In conclusion, beta-lactamase as a primary high-throughput screening assay is a powerful complementation to other screening technologies. The beta-lactamase technology has several advantages, including lack of cell lysis and ratiometric read-out, which augments assay robustness. Based on technology comparison, it is not adequate to assume that the same hits would be found regardless of which assay technology is used.
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Affiliation(s)
- Julia Oosterom
- Molecular Pharmacology, N.V. Organon, Oss, The Netherlands.
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37
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Mehlmann LM, Saeki Y, Tanaka S, Brennan TJ, Evsikov AV, Pendola FL, Knowles BB, Eppig JJ, Jaffe LA. The Gs-Linked Receptor GPR3 Maintains Meiotic Arrest in Mammalian Oocytes. Science 2004; 306:1947-50. [PMID: 15591206 DOI: 10.1126/science.1103974] [Citation(s) in RCA: 256] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mammalian oocytes are held in prophase arrest by an unknown signal from the surrounding somatic cells. Here we show that the orphan Gs-linked receptor GPR3, which is localized in the oocyte, maintains this arrest. Oocytes from Gpr3 knockout mice resume meiosis within antral follicles, independently of an increase in luteinizing hormone, and this phenotype can be reversed by injection of Gpr3 RNA into the oocytes. Thus, the GPR3 receptor is a link in communication between the somatic cells and oocyte of the ovarian follicle and is crucial for the regulation of meiosis.
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Affiliation(s)
- Lisa M Mehlmann
- Department of Cell Biology, University of Connecticut Health Center (UCHC), Farmington, CT 06032, USA.
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38
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Dunlop J, Eglen RM. Identifying orphan G protein coupled receptors in drug discovery. DRUG DISCOVERY TODAY. TECHNOLOGIES 2004; 1:61-8. [PMID: 24981269 DOI: 10.1016/j.ddtec.2004.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
G-protein coupled receptors (GPCRs) represent the most tractable family of drug targets. Those GPCRs identified by sequence only, but lacking an endogenous ligand, are defined as orphan GPCRs (oGPCRs) and might represent the next generation of targets for GPCR drug discovery. Drug discovery at oGPCRs is a resource intensive approach and frequently taken 'at-risk' without a clear understanding of the role in a disease. Identification of oGPCRs is, therefore, a prerequisite for the initiation of a drug discovery program.:
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Affiliation(s)
- John Dunlop
- Neuroscience Discovery Research, Wyeth Research, CN-8000, Princeton, NJ 08543, USA
| | - Richard M Eglen
- DiscoveRx Corporation, 42501 Albrae St. Fremont, CA 94538, USA.
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