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Wu KC, Leong IL, Leung YM. Ca 2+-sensing receptor-TRP channel-mediated Ca 2+ signaling: Functional diversity and pharmacological complexity. Eur J Pharmacol 2024; 977:176717. [PMID: 38857682 DOI: 10.1016/j.ejphar.2024.176717] [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: 01/10/2024] [Revised: 05/07/2024] [Accepted: 06/05/2024] [Indexed: 06/12/2024]
Abstract
The Ca2+-sensing receptor (CaSR) is a G-protein-coupled receptor activated by elevated concentrations of extracellular Ca2+, and was initially known for its regulation of parathyroid hormone (PTH) release. Ubiquitous expression of CaSR in different tissues and organs was later noted and CaSR participation in various physiological functions was demonstrated. Accumulating evidence has suggested that CaSR functionally interacts with transient receptor potential (TRP) channels, which are mostly non-selective cation channels involved in sensing temperature, pain and stress. This review describes the interactions of CaSR with TRP channels in diverse cell types to trigger a variety of biological responses. CaSR has been known to interact with different types of G proteins. Possible involvements of G proteins, other signaling and scaffolding protein intermediates in CaSR-TRP interaction are discussed. In addition, an attempt will be made to extend the current understanding of biased agonism of CaSR.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology, Chiayi, Taiwan; Shu-Zen Junior College of Medicine and Management, Kaohsiung, Taiwan
| | - Iat-Lon Leong
- Division of Cardiology, University Hospital, Macau University of Science and Technology, Macau
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan.
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2
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Díaz-Piña DA, Rivera-Ramírez N, García-López G, Díaz NF, Molina-Hernández A. Calcium and Neural Stem Cell Proliferation. Int J Mol Sci 2024; 25:4073. [PMID: 38612887 PMCID: PMC11012558 DOI: 10.3390/ijms25074073] [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: 02/08/2024] [Revised: 03/31/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
Intracellular calcium plays a pivotal role in central nervous system (CNS) development by regulating various processes such as cell proliferation, migration, differentiation, and maturation. However, understanding the involvement of calcium (Ca2+) in these processes during CNS development is challenging due to the dynamic nature of this cation and the evolving cell populations during development. While Ca2+ transient patterns have been observed in specific cell processes and molecules responsible for Ca2+ homeostasis have been identified in excitable and non-excitable cells, further research into Ca2+ dynamics and the underlying mechanisms in neural stem cells (NSCs) is required. This review focuses on molecules involved in Ca2+ entrance expressed in NSCs in vivo and in vitro, which are crucial for Ca2+ dynamics and signaling. It also discusses how these molecules might play a key role in balancing cell proliferation for self-renewal or promoting differentiation. These processes are finely regulated in a time-dependent manner throughout brain development, influenced by extrinsic and intrinsic factors that directly or indirectly modulate Ca2+ dynamics. Furthermore, this review addresses the potential implications of understanding Ca2+ dynamics in NSCs for treating neurological disorders. Despite significant progress in this field, unraveling the elements contributing to Ca2+ intracellular dynamics in cell proliferation remains a challenging puzzle that requires further investigation.
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Affiliation(s)
- Dafne Astrid Díaz-Piña
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Montes Urales 800, Miguel Hidalgo, Ciudad de México 11000, Mexico
- Facultad de Medicina, Circuito Exterior Universitario, Universidad Nacional Autónoma de México Universitario, Copilco Universidad, Coyoacán, Ciudad de México 04360, Mexico
| | - Nayeli Rivera-Ramírez
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Montes Urales 800, Miguel Hidalgo, Ciudad de México 11000, Mexico
| | - Guadalupe García-López
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Montes Urales 800, Miguel Hidalgo, Ciudad de México 11000, Mexico
| | - Néstor Fabián Díaz
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Montes Urales 800, Miguel Hidalgo, Ciudad de México 11000, Mexico
| | - Anayansi Molina-Hernández
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Montes Urales 800, Miguel Hidalgo, Ciudad de México 11000, Mexico
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Ikeda Y, Fujii J. The Emerging Roles of γ-Glutamyl Peptides Produced by γ-Glutamyltransferase and the Glutathione Synthesis System. Cells 2023; 12:2831. [PMID: 38132151 PMCID: PMC10741565 DOI: 10.3390/cells12242831] [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: 10/24/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
L-γ-Glutamyl-L-cysteinyl-glycine is commonly referred to as glutathione (GSH); this ubiquitous thiol plays essential roles in animal life. Conjugation and electron donation to enzymes such as glutathione peroxidase (GPX) are prominent functions of GSH. Cellular glutathione balance is robustly maintained via regulated synthesis, which is catalyzed via the coordination of γ-glutamyl-cysteine synthetase (γ-GCS) and glutathione synthetase, as well as by reductive recycling by glutathione reductase. A prevailing short supply of L-cysteine (Cys) tends to limit glutathione synthesis, which leads to the production of various other γ-glutamyl peptides due to the unique enzymatic properties of γ-GCS. Extracellular degradation of glutathione by γ-glutamyltransferase (GGT) is a dominant source of Cys for some cells. GGT catalyzes the hydrolytic removal of the γ-glutamyl group of glutathione or transfers it to amino acids or to dipeptides outside cells. Such processes depend on an abundance of acceptor substrates. However, the physiological roles of extracellularly preserved γ-glutamyl peptides have long been unclear. The identification of γ-glutamyl peptides, such as glutathione, as allosteric modulators of calcium-sensing receptors (CaSRs) could provide insights into the significance of the preservation of γ-glutamyl peptides. It is conceivable that GGT could generate a new class of intercellular messaging molecules in response to extracellular microenvironments.
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Affiliation(s)
- Yoshitaka Ikeda
- Division of Molecular Cell Biology, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata City 990-9585, Japan
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Fujii J, Osaki T, Soma Y, Matsuda Y. Critical Roles of the Cysteine-Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System. Int J Mol Sci 2023; 24:ijms24098044. [PMID: 37175751 PMCID: PMC10179188 DOI: 10.3390/ijms24098044] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys-GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys-GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.
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Affiliation(s)
- Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Tsukasa Osaki
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Yuya Soma
- Graduate School of Nursing, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan
| | - Yumi Matsuda
- Graduate School of Nursing, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan
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Chinoy A, Nicholson J, Skae M, Hannan FM, Thakker RV, Mughal MZ, Padidela R. Neurodevelopmental Abnormalities in Patients with Familial Hypocalciuric Hypercalcemia Type 3. J Pediatr 2023:S0022-3476(23)00126-9. [PMID: 36868303 DOI: 10.1016/j.jpeds.2023.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/26/2022] [Accepted: 02/24/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVES To evaluate the prevalence and degree of any neurodevelopmental abnormalities in children with familial hypocalciuric hypercalcemia type 3 (FHH3). STUDY DESIGN A formal neurodevelopmental assessment was performed in children diagnosed with FHH3. The Vineland Adaptive Behavior Scales, which is a standardized parent report assessment tool for adaptive behavior, was used to assess communication, social skills, and motor function and to generate a composite score. RESULTS Six patients were diagnosed with hypercalcemia between 0.1 and 8 years of age. All had neurodevelopmental abnormalities in childhood consisting of either global developmental delay, motor delay, expressive speech disturbances, learning difficulties, hyperactivity, or autism spectrum disorder. Four out of the 6 probands had a composite Vineland Adaptive Behavior Scales SDS of < -2.0, indicating adaptive malfunctioning. Significant deficits were observed in the domains of communication (mean SDS: -2.0, P < .01), social skills (mean SDS: -1.3, P < .05), and motor skills (mean SDS: 2.6, P < .05). Individuals were equally affected across domains, with no clear genotype-phenotype correlation. All family members affected with FHH3 also described evidence of neurodevelopmental dysfunction, including mild-to-moderate learning difficulties, dyslexia, and hyperactivity. CONCLUSION Neurodevelopmental abnormalities appear to be a highly penetrant and common feature of FHH3, and early detection is warranted to provide appropriate educational support. This case series also supports consideration of serum calcium measurement as part of the diagnostic work-up in any child presenting with unexplained neurodevelopmental abnormalities.
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Affiliation(s)
- Amish Chinoy
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom.
| | - Jacqueline Nicholson
- Paediatric Psychosocial Department, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Mars Skae
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - Fadil M Hannan
- Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom; NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - M Zulf Mughal
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - Raja Padidela
- Paediatric Endocrine Department, Royal Manchester Children's Hospital, Manchester, United Kingdom; Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
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Chen L, Li S, Shi W, Wu Y. An Integrative Transcriptomic Analysis Reveals EGFR Exon-19 E746-A750 Fragment Deletion Regulated miRNA, circRNA, mRNA and lncRNA Networks in Lung Carcinoma. Int J Gen Med 2022; 15:6031-6042. [PMID: 35818580 PMCID: PMC9270948 DOI: 10.2147/ijgm.s370247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/27/2022] [Indexed: 11/23/2022] Open
Abstract
Introduction Competing endogenous RNA (ceRNA) appears to be an important post-transcriptional manner that regulates gene expression through a miRNA-mediated mechanism. Mutations in exon-19 of EGFR were frequently observed in lung cancer genes, which were associated with EGFR activity and EGFR-targeted therapies. Methods We explored the transcriptome regulated by mutation in EGFR exon-19 E746-A750 fragment via using a network modeling strategy. We applied transcriptome sequencing to detect the deletion process of EGFR exon-19 E746-A750 fragment. Bio-informatics analyses were used to predict the gene target pairs and explain their potential roles in tumorigenesis and progression of lung cancer. Results We conducted an explorative lncRNA/miRNA/circRNA and mRNA expression study with two groups of lung adenocarcinoma tissues, including EGFR exon-19 E746-A750 deletion group and EGFR exon-19 wild-type group. Meanwhile, we screen out the hub genes related to the EGFR-19-D patient. Significant pathways and biological functions potentially regulated by the deregulated 128 non-coding genes were enriched. Conclusion Our work provides an important theoretical, experimental and clinical foundation for further research on more effective targets for the diagnosis, therapy and prognosis of lung cancer.
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Affiliation(s)
- Ling Chen
- The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, People’s Republic of China
| | - Shenyi Li
- The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, People’s Republic of China
| | - Weifeng Shi
- The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, People’s Republic of China
| | - Yibo Wu
- The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, People’s Republic of China
- Correspondence: Yibo Wu; Weifeng Shi, The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, People’s Republic of China, Tel +86-510-68089762; +86-510-68089762, Fax +86-510-68089762, Email ;
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Goralski T, Ram JL. Extracellular Calcium Receptor as a Target for Glutathione and Its Derivatives. Int J Mol Sci 2022; 23:ijms23020717. [PMID: 35054903 PMCID: PMC8776003 DOI: 10.3390/ijms23020717] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/03/2022] [Accepted: 01/05/2022] [Indexed: 12/16/2022] Open
Abstract
Extracellular glutathione (GSH) and oxidized glutathione (GSSG) can modulate the function of the extracellular calcium sensing receptor (CaSR). The CaSR has a binding pocket in the extracellular domain of CaSR large enough to bind either GSH or GSSG, as well as the naturally occurring oxidized derivative L-cysteine glutathione disulfide (CySSG) and the compound cysteinyl glutathione (CysGSH). Modeling the binding energies (ΔG) of CySSG and CysGSH to CaSR reveals that both cysteine derivatives may have greater affinities for CaSR than either GSH or GSSG. GSH, CySSG, and GSSG are found in circulation in mammals and, among the three, CySSG is more affected by HIV/AIDs and aging than either GSH or GSSG. The beta-carbon linkage of cysteine in CysGSH may model a new class of calcimimetics, exemplified by etelcalcetide. Circulating glutathionergic compounds, particularly CySSG, may mediate calcium-regulatory responses via receptor-binding to CaSR in a variety of organs, including parathyroids, kidneys, and bones. Receptor-mediated actions of glutathionergics may thus complement their roles in redox regulation and detoxification. The glutathionergic binding site(s) on CaSR are suggested to be a target for development of drugs that can be used in treating kidney and other diseases whose mechanisms involve CaSR dysregulation.
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Affiliation(s)
- Thomas Goralski
- Department of Physiology, Wayne State University, Detroit, MI 48201, USA;
- Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Jeffrey L. Ram
- Department of Physiology, Wayne State University, Detroit, MI 48201, USA;
- Correspondence: ; Tel.: +1-248-200-9431
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Lu Y, Wang J, Soladoye OP, Aluko RE, Fu Y, Zhang Y. Preparation, receptors, bioactivity and bioavailability of γ-glutamyl peptides: A comprehensive review. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.04.051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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9
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Tiwari A, Khera R, Rahi S, Mehan S, Makeen HA, Khormi YH, Rehman MU, Khan A. Neuroprotective Effect of α-Mangostin in the Ameliorating Propionic Acid-Induced Experimental Model of Autism in Wistar Rats. Brain Sci 2021; 11:brainsci11030288. [PMID: 33669120 PMCID: PMC7996534 DOI: 10.3390/brainsci11030288] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/09/2021] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
Several studies have documented the role of hyper-activation of extracellular signal-regulated kinases (ERK) in Autism pathogenesis. Alpha-mangostin (AMG) is a phytoconstituents with anti-oxidants, anti-inflammatory, and ERK inhibition properties in many diseases. Our research aims to investigate the neuroprotective effect of AMG in the rat model of intracerebroventricular-propionic acid (ICV-PPA) induced autism with a confirmation of its effect on the ERK signaling. Autism was induced in Wistar rats (total 36 rats; 18 male/18 female) by multiple doses of PPA through ICV injection for 11 days. Actophotometer and beam walking tasks were used to evaluate animals’ motor abilities, and the Morris water maze task was utilized to confirm the cognition and memory in animals. Long term administration of AMG100 mg/kg and AMG200 mg/kg continued from day 12 to day 44 of the experiment. Before that, animals were sacrificed, brains isolated, morphological, gross pathological studies were performed, and neurochemical analysis was performed in the brain homogenates. Cellular and molecular markers, including ERK, myelin basic protein, apoptotic markers including caspase-3, Bax, Bcl-2, neuroinflammatory markers, neurotransmitters, and oxidative stress markers, have been tested throughout the brain. Thus, AMG reduces the overactivation of the ERK signaling and also restored autism-like behavioral and neurochemical alterations.
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Affiliation(s)
- Aarti Tiwari
- Department of Pharmacology, Neuropharmacology Division, ISF College of Pharmacy, Moga, Punjab 142001, India; (A.T.); (R.K.); (S.R.)
| | - Rishabh Khera
- Department of Pharmacology, Neuropharmacology Division, ISF College of Pharmacy, Moga, Punjab 142001, India; (A.T.); (R.K.); (S.R.)
| | - Saloni Rahi
- Department of Pharmacology, Neuropharmacology Division, ISF College of Pharmacy, Moga, Punjab 142001, India; (A.T.); (R.K.); (S.R.)
| | - Sidharth Mehan
- Department of Pharmacology, Neuropharmacology Division, ISF College of Pharmacy, Moga, Punjab 142001, India; (A.T.); (R.K.); (S.R.)
- Correspondence: (S.M.); (A.K.); Tel.: +91-80-5988-9909 (S.M.)
| | - Hafiz Antar Makeen
- Department of Clinical Pharmacy, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia;
| | - Yahya H. Khormi
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Jazan University, Jazan 45142, Saudi Arabia;
| | - Muneeb U Rehman
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Andleeb Khan
- Department of Pharmacology & Toxicology, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia
- Correspondence: (S.M.); (A.K.); Tel.: +91-80-5988-9909 (S.M.)
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Danger-Sensing/Patten Recognition Receptors and Neuroinflammation in Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21239036. [PMID: 33261147 PMCID: PMC7731137 DOI: 10.3390/ijms21239036] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
Fibrillar aggregates and soluble oligomers of both Amyloid-β peptides (Aβs) and hyperphosphorylated Tau proteins (p-Tau-es), as well as a chronic neuroinflammation are the main drivers causing progressive neuronal losses and dementia in Alzheimer’s disease (AD). However, the underlying pathogenetic mechanisms are still much disputed. Several endogenous neurotoxic ligands, including Aβs, and/or p-Tau-es activate innate immunity-related danger-sensing/pattern recognition receptors (PPRs) thereby advancing AD’s neuroinflammation and progression. The major PRR families involved include scavenger, Toll-like, NOD-like, AIM2-like, RIG-like, and CLEC-2 receptors, plus the calcium-sensing receptor (CaSR). This quite intricate picture stresses the need to identify the pathogenetically topmost Aβ-activated PRR, whose signaling would trigger AD’s three main drivers and their intra-brain spread. In theory, the candidate might belong to any PRR family. However, results of preclinical studies using in vitro nontumorigenic human cortical neurons and astrocytes and in vivo AD-model animals have started converging on the CaSR as the pathogenetically upmost PRR candidate. In fact, the CaSR binds both Ca2+ and Aβs and promotes the spread of both Ca2+ dyshomeostasis and AD’s three main drivers, causing a progressive neurons’ death. Since CaSR’s negative allosteric modulators block all these effects, CaSR’s candidacy for topmost pathogenetic PRR has assumed a growing therapeutic potential worth clinical testing.
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Arrais AC, Melo LHMF, Norrara B, Almeida MAB, Freire KF, Melo AMMF, Oliveira LCD, Lima FOV, Engelberth RCGJ, Cavalcante JDS, Araújo DPD, Guzen FP, Freire MAM, Cavalcanti JRLP. S100B protein: general characteristics and pathophysiological implications in the Central Nervous System. Int J Neurosci 2020; 132:313-321. [DOI: 10.1080/00207454.2020.1807979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ana Cristina Arrais
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Lívia Helena M. F. Melo
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Bianca Norrara
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Marina Abuquerque B. Almeida
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Kalina Fernandes Freire
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Acydalia Madruga M. F. Melo
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Lucidio Clebeson de Oliveira
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Francisca Overlânia Vieira Lima
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Rovena Clara G. J. Engelberth
- Laboratory of Neurochemical Studies, Department of Physiology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Jeferson de Souza Cavalcante
- Laboratory of Neurochemical Studies, Department of Physiology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Dayane Pessoa de Araújo
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Fausto Pierdoná Guzen
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Marco Aurelio M. Freire
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - José Rodolfo L. P. Cavalcanti
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Faculty of Health Sciences, University of the State of Rio Grande do Norte, Mossoró, RN, Brazil
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Guo T, Zhang D, Zeng Y, Huang TY, Xu H, Zhao Y. Molecular and cellular mechanisms underlying the pathogenesis of Alzheimer's disease. Mol Neurodegener 2020; 15:40. [PMID: 32677986 PMCID: PMC7364557 DOI: 10.1186/s13024-020-00391-7] [Citation(s) in RCA: 431] [Impact Index Per Article: 107.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 06/17/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disorder seen in age-dependent dementia. There is currently no effective treatment for AD, which may be attributed in part to lack of a clear underlying mechanism. Studies within the last few decades provide growing evidence for a central role of amyloid β (Aβ) and tau, as well as glial contributions to various molecular and cellular pathways in AD pathogenesis. Herein, we review recent progress with respect to Aβ- and tau-associated mechanisms, and discuss glial dysfunction in AD with emphasis on neuronal and glial receptors that mediate Aβ-induced toxicity. We also discuss other critical factors that may affect AD pathogenesis, including genetics, aging, variables related to environment, lifestyle habits, and describe the potential role of apolipoprotein E (APOE), viral and bacterial infection, sleep, and microbiota. Although we have gained much towards understanding various aspects underlying this devastating neurodegenerative disorder, greater commitment towards research in molecular mechanism, diagnostics and treatment will be needed in future AD research.
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Affiliation(s)
- Tiantian Guo
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Denghong Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Yuzhe Zeng
- Department of Orthopaedics, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, China
| | - Timothy Y Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.
| | - Huaxi Xu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA.
| | - Yingjun Zhao
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China.
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Feng C, Bao X, Shan L, Ling Y, Ding Y, Wang J, Cao Y, Wang Q, Cui W, Xu S. Calcium-Sensing Receptor Mediates β-Amyloid-Induced Synaptic Formation Impairment and Cognitive Deficits via Regulation of Cytosolic Phospholipase A2/Prostaglandin E2 Metabolic Pathway. Front Aging Neurosci 2020; 12:144. [PMID: 32670047 PMCID: PMC7328130 DOI: 10.3389/fnagi.2020.00144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Calcium-sensing receptor (CaSR) is a G protein-coupled receptor (GPCRs). Soluble β-amyloid peptide (Aβ) is one of the orthosteric modulators of CaSR, while, the role and underlying mechanism of CaSR in cognitive decline in Alzheimer’s disease (AD) is unclear. In this study, molecular technology such as live-cell imaging combined with behavioral tests were used to explore the role and the underlying mechanism of CaSR in the cognitive deficits in AD mice. The expression levels of CaSR were increased both in AD mice and Aβ1–42 (β-amyloid protein)-treated primary cultured neurons. Pharmacological inhibition of CaSR ameliorated recognitive and spatial memory deficits of Aβ1–42-oligomer-treated mice in a dose-dependent manner. Pharmacological inhibition of CaSR or down-regulation of the expression of CaSR by CaSR-shRNA-lentivirus prevented the impairment of filopodia, and the synapse induced by oligomeric Aβ1–42. The contents of cytosolic phospholipase A2 (cPLA2) and prostaglandin E2 (PGE2) in hippocampal neurons and tissue were increased after treatment with Aβ1–42 oligomers. Inhibition or down-regulation of CaSR mediates Aβ-induced synapse formation and cognitive deficits partially, through the activation of the cPLA2/PGE2 pathway. This study provides novel insights on CaSR, which is a promising therapeutic target for AD.
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Affiliation(s)
- Chenxi Feng
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China.,Children's Hospital of Soochow University, Suzhou, China
| | - Xiaoming Bao
- HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo, China.,Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
| | - Ling Shan
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Yunxiang Ling
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Yanfei Ding
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Jia Wang
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Yanzi Cao
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Qinwen Wang
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Wei Cui
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
| | - Shujun Xu
- School of Medicine, Ningbo University, Zhejiang Provincial Key Laboratory of Pathophysiology, Ningbo, China
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Chiarini A, Armato U, Hu P, Dal Prà I. CaSR Antagonist (Calcilytic) NPS 2143 Hinders the Release of Neuroinflammatory IL-6, Soluble ICAM-1, RANTES, and MCP-2 from Aβ-Exposed Human Cortical Astrocytes. Cells 2020; 9:cells9061386. [PMID: 32498476 PMCID: PMC7349863 DOI: 10.3390/cells9061386] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/29/2020] [Accepted: 05/29/2020] [Indexed: 02/07/2023] Open
Abstract
Available evidence shows that human cortical neurons’ and astrocytes’ calcium-sensing receptors (CaSRs) bind Amyloid-beta (Aβ) oligomers triggering the overproduction/oversecretion of several Alzheimer’s disease (AD) neurotoxins—effects calcilytics suppress. We asked whether Aβ•CaSR signaling might also play a direct pro-neuroinflammatory role in AD. Cortical nontumorigenic adult human astrocytes (NAHAs) in vitro were untreated (controls) or treated with Aβ25–35 ± NPS 2143 (a calcilytic) and any proinflammatory agent in their protein lysates and growth media assayed via antibody arrays, enzyme-linked immunosorbent assays (ELISAs), and immunoblots. Results show Aβ•CaSR signaling upregulated the synthesis and release/shedding of proinflammatory interleukin (IL)-6, intercellular adhesion molecule-1 (ICAM-1) (holoprotein and soluble [s] fragment), Regulated upon Activation, normal T cell Expressed and presumably Secreted (RANTES), and monocyte chemotactic protein (MCP)-2. Adding NPS 2143 (i) totally suppressed IL-6′s oversecretion while remarkably reducing the other agents’ over-release; and (ii) more effectively than Aβ alone increased over controls the four agents’ distinctive intracellular accumulation. Conversely, NPS 2143 did not alter Aβ-induced surges in IL-1β, IL-3, IL-8, and IL-16 secretion, consequently revealing their Aβ•CaSR signaling-independence. Finally, Aβ25–35 ± NPS 2143 treatments left unchanged MCP-1′s and TIMP-2′s basal expression. Thus, NAHAs Aβ•CaSR signaling drove four proinflammatory agents’ over-release that NPS 2143 curtailed. Therefore, calcilytics would also abate NAHAs’ Aβ•CaSR signaling direct impact on AD’s neuroinflammation.
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Affiliation(s)
- Anna Chiarini
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics and Gynecology, Medical School, University of Verona, Veneto, 37134 Verona, Italy; (U.A.); (P.H.)
- Correspondence: (A.C.); (I.D.P.); Tel.: +39-045-802-7646 (A.C.); +39-045-802-7161 (I.D.P)
| | - Ubaldo Armato
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics and Gynecology, Medical School, University of Verona, Veneto, 37134 Verona, Italy; (U.A.); (P.H.)
- Burns Department, Shenzhen Second People’s Hospital, University of Shenzhen, Shenzhen 518000, China
| | - Peng Hu
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics and Gynecology, Medical School, University of Verona, Veneto, 37134 Verona, Italy; (U.A.); (P.H.)
| | - Ilaria Dal Prà
- Human Histology and Embryology Section, Department of Surgery, Dentistry, Pediatrics and Gynecology, Medical School, University of Verona, Veneto, 37134 Verona, Italy; (U.A.); (P.H.)
- Burns Department, Shenzhen Second People’s Hospital, University of Shenzhen, Shenzhen 518000, China
- Correspondence: (A.C.); (I.D.P.); Tel.: +39-045-802-7646 (A.C.); +39-045-802-7161 (I.D.P)
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15
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Lagunin AA, Ivanov SM, Gloriozova TA, Pogodin PV, Filimonov DA, Kumar S, Goel RK. Combined network pharmacology and virtual reverse pharmacology approaches for identification of potential targets to treat vascular dementia. Sci Rep 2020; 10:257. [PMID: 31937840 PMCID: PMC6959222 DOI: 10.1038/s41598-019-57199-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/21/2019] [Indexed: 02/07/2023] Open
Abstract
Dementia is a major cause of disability and dependency among older people. If the lives of people with dementia are to be improved, research and its translation into druggable target are crucial. Ancient systems of healthcare (Ayurveda, Siddha, Unani and Sowa-Rigpa) have been used from centuries for the treatment vascular diseases and dementia. This traditional knowledge can be transformed into novel targets through robust interplay of network pharmacology (NetP) with reverse pharmacology (RevP), without ignoring cutting edge biomedical data. This work demonstrates interaction between recent and traditional data, and aimed at selection of most promising targets for guiding wet lab validations. PROTEOME, DisGeNE, DISEASES and DrugBank databases were used for selection of genes associated with pathogenesis and treatment of vascular dementia (VaD). The selection of new potential drug targets was made by methods of NetP (DIAMOnD algorithm, enrichment analysis of KEGG pathways and biological processes of Gene Ontology) and manual expert analysis. The structures of 1976 phytomolecules from the 573 Indian medicinal plants traditionally used for the treatment of dementia and vascular diseases were used for computational estimation of their interactions with new predicted VaD-related drug targets by RevP approach based on PASS (Prediction of Activity Spectra for Substances) software. We found 147 known genes associated with vascular dementia based on the analysis of the databases with gene-disease associations. Six hundred novel targets were selected by NetP methods based on 147 gene associations. The analysis of the predicted interactions between 1976 phytomolecules and 600 NetP predicted targets leaded to the selection of 10 potential drug targets for the treatment of VaD. The translational value of these targets is discussed herewith. Twenty four drugs interacting with 10 selected targets were identified from DrugBank. These drugs have not been yet studied for the treatment of VaD and may be investigated in this field for their repositioning. The relation between inhibition of two selected targets (GSK-3, PTP1B) and the treatment of VaD was confirmed by the experimental studies on animals and reported separately in our recent publications.
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Affiliation(s)
- Alexey A Lagunin
- Pirogov Russian National Research Medical University, Department of Bioinformatics, Moscow, 117997, Russia.
- Institute of Biomedical Chemistry, Department of Bioinformatics, Moscow, 119121, Russia.
| | - Sergey M Ivanov
- Pirogov Russian National Research Medical University, Department of Bioinformatics, Moscow, 117997, Russia
- Institute of Biomedical Chemistry, Department of Bioinformatics, Moscow, 119121, Russia
| | - Tatyana A Gloriozova
- Institute of Biomedical Chemistry, Department of Bioinformatics, Moscow, 119121, Russia
| | - Pavel V Pogodin
- Institute of Biomedical Chemistry, Department of Bioinformatics, Moscow, 119121, Russia
| | - Dmitry A Filimonov
- Institute of Biomedical Chemistry, Department of Bioinformatics, Moscow, 119121, Russia
| | - Sandeep Kumar
- Punjabi University, Department of Pharmaceutical Sciences and Drug Research, Patiala, 147002, India
| | - Rajesh K Goel
- Punjabi University, Department of Pharmaceutical Sciences and Drug Research, Patiala, 147002, India.
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16
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Sensing Extracellular Calcium - An Insight into the Structure and Function of the Calcium-Sensing Receptor (CaSR). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:1031-1063. [PMID: 31646544 DOI: 10.1007/978-3-030-12457-1_41] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The calcium-sensing receptor (CaSR) is a G protein-coupled receptor that plays a key role in calcium homeostasis, by sensing free calcium levels in blood and regulating parathyroid hormone secretion in response. The CaSR is highly expressed in parathyroid gland and kidney where its role is well characterised, but also in other tissues where its function remains to be determined. The CaSR can be activated by a variety of endogenous ligands, as well as by synthetic modulators such as Cinacalcet, used in the clinic to treat secondary hyperparathyroidism in patients with chronic kidney disease. The CaSR couples to multiple G proteins, in a tissue-specific manner, activating several signalling pathways and thus regulating diverse intracellular events. The multifaceted nature of this receptor makes it a valuable therapeutic target for calciotropic and non-calciotropic diseases. It is therefore essential to understand the complexity behind the pharmacology, trafficking, and signalling characteristics of this receptor. This review provides an overview of the latest knowledge about the CaSR and discusses future hot topics in this field.
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17
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Fonin AV, Darling AL, Kuznetsova IM, Turoverov KK, Uversky VN. Multi-functionality of proteins involved in GPCR and G protein signaling: making sense of structure-function continuum with intrinsic disorder-based proteoforms. Cell Mol Life Sci 2019; 76:4461-4492. [PMID: 31428838 PMCID: PMC11105632 DOI: 10.1007/s00018-019-03276-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/05/2019] [Accepted: 08/12/2019] [Indexed: 12/21/2022]
Abstract
GPCR-G protein signaling system recognizes a multitude of extracellular ligands and triggers a variety of intracellular signaling cascades in response. In humans, this system includes more than 800 various GPCRs and a large set of heterotrimeric G proteins. Complexity of this system goes far beyond a multitude of pair-wise ligand-GPCR and GPCR-G protein interactions. In fact, one GPCR can recognize more than one extracellular signal and interact with more than one G protein. Furthermore, one ligand can activate more than one GPCR, and multiple GPCRs can couple to the same G protein. This defines an intricate multifunctionality of this important signaling system. Here, we show that the multifunctionality of GPCR-G protein system represents an illustrative example of the protein structure-function continuum, where structures of the involved proteins represent a complex mosaic of differently folded regions (foldons, non-foldons, unfoldons, semi-foldons, and inducible foldons). The functionality of resulting highly dynamic conformational ensembles is fine-tuned by various post-translational modifications and alternative splicing, and such ensembles can undergo dramatic changes at interaction with their specific partners. In other words, GPCRs and G proteins exist as sets of conformational/basic, inducible/modified, and functioning proteoforms characterized by a broad spectrum of structural features and possessing various functional potentials.
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Affiliation(s)
- Alexander V Fonin
- Laboratory of structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - April L Darling
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Irina M Kuznetsova
- Laboratory of structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Konstantin K Turoverov
- Laboratory of structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
- Department of Biophysics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya av. 29, St. Petersburg, 195251, Russian Federation
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
- Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow, Russian Federation.
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18
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Dal Prà I, Armato U, Chiarini A. Family C G-Protein-Coupled Receptors in Alzheimer's Disease and Therapeutic Implications. Front Pharmacol 2019; 10:1282. [PMID: 31719824 PMCID: PMC6826475 DOI: 10.3389/fphar.2019.01282] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/07/2019] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD), particularly its sporadic or late-onset form (SAD/LOAD), is the most prevalent (96–98% of cases) neurodegenerative dementia in aged people. AD’s neuropathology hallmarks are intrabrain accumulation of amyloid-β peptides (Aβs) and of hyperphosphorylated Tau (p-Tau) proteins, diffuse neuroinflammation, and progressive death of neurons and oligodendrocytes. Mounting evidences suggest that family C G-protein-coupled receptors (GPCRs), which include γ-aminobutyric acid B receptors (GABABRs), metabotropic glutamate receptors (mGluR1-8), and the calcium-sensing receptor (CaSR), are involved in many neurotransmitter systems that dysfunction in AD. This review updates the available knowledge about the roles of GPCRs, particularly but not exclusively those expressed by brain astrocytes, in SAD/LOAD onset and progression, taking stock of their respective mechanisms of action and of their potential as anti-AD therapeutic targets. In particular, GABABRs prevent Aβs synthesis and neuronal hyperexcitability and group I mGluRs play important pathogenetic roles in transgenic AD-model animals. Moreover, the specific binding of Aβs to the CaSRs of human cortical astrocytes and neurons cultured in vitro engenders a pathological signaling that crucially promotes the surplus synthesis and release of Aβs and hyperphosphorylated Tau proteins, and also of nitric oxide, vascular endothelial growth factor-A, and proinflammatory agents. Concurrently, Aβs•CaSR signaling hinders the release of soluble (s)APP-α peptide, a neurotrophic agent and GABABR1a agonist. Altogether these effects progressively kill human cortical neurons in vitro and likely also in vivo. Several CaSR’s negative allosteric modulators suppress all the noxious effects elicited by Aβs•CaSR signaling in human cortical astrocytes and neurons thus safeguarding neurons’ viability in vitro and raising hopes about their potential therapeutic benefits in AD patients. Further basic and clinical investigations on these hot topics are needed taking always heed that activation of the several brain family C GPCRs may elicit divergent upshots according to the models studied.
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Affiliation(s)
- Ilaria Dal Prà
- Human Histology and Embryology Unit, University of Verona Medical School, Verona, Italy
| | - Ubaldo Armato
- Human Histology and Embryology Unit, University of Verona Medical School, Verona, Italy
| | - Anna Chiarini
- Human Histology and Embryology Unit, University of Verona Medical School, Verona, Italy
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19
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Hannan FM, Kallay E, Chang W, Brandi ML, Thakker RV. The calcium-sensing receptor in physiology and in calcitropic and noncalcitropic diseases. Nat Rev Endocrinol 2018; 15:33-51. [PMID: 30443043 PMCID: PMC6535143 DOI: 10.1038/s41574-018-0115-0] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Ca2+-sensing receptor (CaSR) is a dimeric family C G protein-coupled receptor that is expressed in calcitropic tissues such as the parathyroid glands and the kidneys and signals via G proteins and β-arrestin. The CaSR has a pivotal role in bone and mineral metabolism, as it regulates parathyroid hormone secretion, urinary Ca2+ excretion, skeletal development and lactation. The importance of the CaSR for these calcitropic processes is highlighted by loss-of-function and gain-of-function CaSR mutations that cause familial hypocalciuric hypercalcaemia and autosomal dominant hypocalcaemia, respectively, and also by the fact that alterations in parathyroid CaSR expression contribute to the pathogenesis of primary and secondary hyperparathyroidism. Moreover, the CaSR is an established therapeutic target for hyperparathyroid disorders. The CaSR is also expressed in organs not involved in Ca2+ homeostasis: it has noncalcitropic roles in lung and neuronal development, vascular tone, gastrointestinal nutrient sensing, wound healing and secretion of insulin and enteroendocrine hormones. Furthermore, the abnormal expression or function of the CaSR is implicated in cardiovascular and neurological diseases, as well as in asthma, and the CaSR is reported to protect against colorectal cancer and neuroblastoma but increase the malignant potential of prostate and breast cancers.
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Affiliation(s)
- Fadil M Hannan
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Enikö Kallay
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Wenhan Chang
- Endocrine Research Unit, Veterans Affairs Medical Center, University of California, San Francisco, San Francisco, CA, USA
| | - Maria Luisa Brandi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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20
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Lee JY, Oh SJ. Functional Analysis and Immunochemical Analyses of Ca 2+ Homeostasis-Related Proteins Expression of Glaucoma-Induced Retinal Degeneration in Rats. Exp Neurobiol 2018. [PMID: 29535566 PMCID: PMC5840458 DOI: 10.5607/en.2018.27.1.16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The retinal degeneration resulting from elevated intraocular pressure was evaluated through functional and morphological analyses, for better understanding of the pathophysiology of glaucoma. Ocular hypertension was induced via unilateral episcleral venous cauterization in rats. Experimental time was set at 1 and 3 days, and 1, 2, 4, and 8 weeks post-operation. Retinal function was analyzed using electroretinography. For morphological analysis, retinal tissues were processed for immunochemistry by using antibodies against the calcium-sensing receptor and calcium-binding proteins. Apoptosis was analyzed using the TUNEL method and electron microscopy. Amplitudes of a- and b-wave in scotopic and photopic responses were found to be reduced in all glaucomatous retinas. Photopic negative response for ganglion cell function significantly reduced from 1-day and more significantly reduced in 2-week glaucoma. Calcium-sensing receptor immunoreactivity in ganglion cells remarkably reduced at 8 weeks; conversely, protein amounts increased significantly. Calcium-binding proteins immunoreactivity in amacrine cells clearly reduced at 8 weeks, despite of uneven changes in protein amounts. Apoptosis appeared in both photoreceptors and ganglion cells in 8-week glaucomatous retina. Apoptotic feature of photoreceptors was typical, whereas that of ganglion cells was necrotic in nature. These findings suggest that elevated intraocular pressure affects the sensitivity of photoreceptors and retinal ganglion cells, and leads to apoptotic death. The calcium-sensing receptor may be a useful detector for alteration of extracellular calcium levels surrounding the ganglion cells.
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Affiliation(s)
- Ji-Yeon Lee
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Su-Ja Oh
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
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21
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Chiarini A, Armato U, Liu D, Dal Prà I. Calcium-Sensing Receptor Antagonist NPS 2143 Restores Amyloid Precursor Protein Physiological Non-Amyloidogenic Processing in Aβ-Exposed Adult Human Astrocytes. Sci Rep 2017; 7:1277. [PMID: 28455519 PMCID: PMC5430644 DOI: 10.1038/s41598-017-01215-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/27/2017] [Indexed: 12/11/2022] Open
Abstract
Physiological non-amyloidogenic processing (NAP) of amyloid precursor holoprotein (hAPP) by α-secretases (e.g., ADAM10) extracellularly sheds neurotrophic/neuroprotective soluble (s)APPα and precludes amyloid-β peptides (Aβs) production via β-secretase amyloidogenic processing (AP). Evidence exists that Aβs interact with calcium-sensing receptors (CaSRs) in human astrocytes and neurons, driving the overrelease of toxic Aβ42/Aβ42-os (oligomers), which is completely blocked by CaSR antagonist (calcilytic) NPS 2143. Here, we investigated the mechanisms underlying NPS 2143 beneficial effects in human astrocytes. Moreover, because Alzheimer's disease (AD) involves neuroinflammation, we examined whether NPS 2143 remained beneficial when both fibrillary (f)Aβ25-35 and a microglial cytokine mixture (CMT) were present. Thus, hAPP NAP prevailed over AP in untreated astrocytes, which extracellularly shed all synthesized sAPPα while secreting basal Aβ40/42 amounts. Conversely, fAβ25-35 alone dramatically reduced sAPPα extracellular shedding while driving Aβ42/Aβ42-os oversecretion that CMT accelerated but not increased, despite a concurring hAPP overexpression. NPS 2143 promoted hAPP and ADAM10 translocation to the plasma membrane, thereby restoring sAPPα extracellular shedding and fully suppressing any Aβ42/Aβ42-os oversecretion, but left hAPP expression unaffected. Therefore, as anti-AD therapeutics calcilytics support neuronal viability by safeguarding astrocytes neurotrophic/neuroprotective sAPPα shedding, suppressing neurons and astrocytes Aβ42/Aβ42-os build-up/secretion, and remaining effective even under AD-typical neuroinflammatory conditions.
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Affiliation(s)
- Anna Chiarini
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy.
| | - Ubaldo Armato
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy
| | - Daisong Liu
- The Third Xiangya Hospital of Central South University, Department of Plastic Surgery, Changsha, Hunan, China
| | - Ilaria Dal Prà
- Human Histology & Embryology Unit, Medical School, University of Verona, Verona, Venetia, Italy.
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22
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Voltage Dependence of a Neuromodulator-Activated Ionic Current. eNeuro 2016; 3:eN-NWR-0038-16. [PMID: 27257619 PMCID: PMC4874538 DOI: 10.1523/eneuro.0038-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/18/2016] [Accepted: 04/25/2016] [Indexed: 02/07/2023] Open
Abstract
The neuromodulatory inward current (IMI) generated by crab Cancer borealis stomatogastric ganglion neurons is an inward current whose voltage dependence has been shown to be crucial in the activation of oscillatory activity of the pyloric network of this system. It has been previously shown that IMI loses its voltage dependence in conditions of low extracellular calcium, but that this effect appears to be regulated by intracellular calmodulin. Voltage dependence is only rarely regulated by intracellular signaling mechanisms. Here we address the hypothesis that the voltage dependence of IMI is mediated by intracellular signaling pathways activated by extracellular calcium. We demonstrate that calmodulin inhibitors and a ryanodine antagonist can reduce IMI voltage dependence in normal Ca(2+), but that, in conditions of low Ca(2+), calmodulin activators do not restore IMI voltage dependence. Further, we show evidence that CaMKII alters IMI voltage dependence. These results suggest that calmodulin is necessary but not sufficient for IMI voltage dependence. We therefore hypothesize that the Ca(2+)/calmodulin requirement for IMI voltage dependence is due to an active sensing of extracellular calcium by a GPCR family calcium-sensing receptor (CaSR) and that the reduction in IMI voltage dependence by a calmodulin inhibitor is due to CaSR endocytosis. Supporting this, preincubation with an endocytosis inhibitor prevented W7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride)-induced loss of IMI voltage dependence, and a CaSR antagonist reduced IMI voltage dependence. Additionally, myosin light chain kinase, which is known to act downstream of the CaSR, seems to play a role in regulating IMI voltage dependence. Finally, a Gβγ-subunit inhibitor also affects IMI voltage dependence, in support of the hypothesis that this process is regulated by a G-protein-coupled CaSR.
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23
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Pak HJ, Riew TR, Shin YJ, Choi JH, Jin X, Lee MY. Enhanced expression of the calcium-sensing receptor in reactive astrocytes following ischemic injury in vivo and in vitro. J Neurol Sci 2016; 366:102-109. [PMID: 27288786 DOI: 10.1016/j.jns.2016.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 11/19/2022]
Abstract
We recently demonstrated that the G protein-coupled calcium-sensing receptor (CaSR) is associated with the pathogenesis of ischemic stroke and may be involved in vascular remodeling and astrogliosis. To further substantiate the involvement of CaSR in the astroglial reaction common to ischemic insults, we investigated the temporal and cell type-specific expression patterns of CaSR in the hippocampus after transient forebrain ischemia. CaSR was constitutively expressed in neurons of the pyramidal and granule cell layers, whereas increased CaSR immunoreactivity was observed in reactive astrocytes, but not in activated microglia or macrophages, in the CA1 region of the post-ischemic hippocampus. Astroglial induction of CaSR expression was evident on days 3-7 after reperfusion and appeared to increase progressively through day 28, at which time CaSR expression was prominent in astrocytes with a highly reactive hypertrophic phenotype and elevated levels of glial fibrillary acidic protein. This expression pattern was supported by results of immunoblot analyses. Furthermore, CaSR expression was upregulated in rat primary cortical astrocytes exposed to oxygen-glucose deprivation, which undergo reactive gliosis-like changes. Thus, our results demonstrate that selective and long-lasting astroglial induction of CaSR expression is a common characteristic of ischemic injury and suggest its involvement in the ischemia-induced astroglial reaction.
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Affiliation(s)
- Ha-Jin Pak
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Yoo-Jin Shin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Jeong-Heon Choi
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Xuyan Jin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea.
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Mateo-Lozano S, García M, Rodríguez-Hernández CJ, de Torres C. Regulation of Differentiation by Calcium-Sensing Receptor in Normal and Tumoral Developing Nervous System. Front Physiol 2016; 7:169. [PMID: 27242543 PMCID: PMC4861737 DOI: 10.3389/fphys.2016.00169] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 04/25/2016] [Indexed: 12/14/2022] Open
Abstract
During normal development of the nervous system (NS), neural progenitor cells (NPCs) produce specialized populations of neurons and glial cells upon cell fate restriction and terminal differentiation. These sequential processes require the dynamic regulation of thousands of genes. The calcium-sensing receptor (CaSR) is temporally and spatially regulated in both neurons and glial cells during development of the NS. In particular, CaSR expression and function have been shown to play a significant role during differentiation of NPCs toward the oligodendrocyte lineage and also in maturation of cerebellar granule cell precursors (GCPs). Moreover, CaSR regulates axonal and dendritic growth in both central and peripheral nervous systems (PNSs), a process necessary for proper construction of mature neuronal networks. On the other hand, several lines of evidence support a role for CaSR in promotion of cell differentiation and inhibition of proliferation in neuroblastoma, a tumor arising from precursor cells of developing PNS. Thus, among the variety of NS functions in which the CaSR participates, this mini-review focuses on its role in differentiation of normal and tumoral cells. Current knowledge of the mechanisms responsible for CaSR regulation and function in these contexts is also discussed, together with the therapeutic opportunities provided by CaSR allosteric modulators.
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Affiliation(s)
- Silvia Mateo-Lozano
- Developmental Tumor Biology Laboratory, Institut de Recerca Pediàtrica - Hospital Sant Joan de Déu Barcelona, Spain
| | - Marta García
- Developmental Tumor Biology Laboratory, Institut de Recerca Pediàtrica - Hospital Sant Joan de Déu Barcelona, Spain
| | - Carlos J Rodríguez-Hernández
- Developmental Tumor Biology Laboratory, Institut de Recerca Pediàtrica - Hospital Sant Joan de Déu Barcelona, Spain
| | - Carmen de Torres
- Developmental Tumor Biology Laboratory, Institut de Recerca Pediàtrica - Hospital Sant Joan de DéuBarcelona, Spain; Department of Oncology, Institut de Recerca Pediàtrica - Hospital Sant Joan de DéuBarcelona, Spain
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Chiarini A, Armato U, Liu D, Dal Prà I. Calcium-Sensing Receptors of Human Neural Cells Play Crucial Roles in Alzheimer's Disease. Front Physiol 2016; 7:134. [PMID: 27199760 PMCID: PMC4844916 DOI: 10.3389/fphys.2016.00134] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/28/2016] [Indexed: 12/21/2022] Open
Abstract
In aged subjects, late-onset Alzheimer's disease (LOAD) starts in the lateral entorhinal allocortex where a failure of clearance mechanisms triggers an accumulation of neurotoxic amyloid-β42 oligomers (Aβ42-os). In neurons and astrocytes, Aβ42-os enhance the transcription of Aβ precursor protein (APP) and β-secretase/BACE1 genes. Thus, by acting together with γ-secretase, the surpluses of APP and BACE1 amplify the endogenous production of Aβ42-os which pile up, damage mitochondria, and are oversecreted. At the plasmalemma, exogenous Aβ42-os bind neurons' and astrocytes' calcium-sensing receptors (CaSRs) activating a set of intracellular signaling pathways which upkeep Aβ42-os intracellular accumulation and oversecretion by hindering Aβ42-os proteolysis. In addition, Aβ42-os accumulating in the extracellular milieu spread and reach mounting numbers of adjacent and remoter teams of neurons and astrocytes which in turn are recruited, again via Aβ42-os•CaSR-governed mechanisms, to produce and release additional Aβ42-os amounts. This relentless self-sustaining mechanism drives AD progression toward upper cortical areas. Later on accumulating Aβ42-os elicit the advent of hyperphosphorylated (p)-Tau oligomers which acting together with Aβ42-os and other glial neurotoxins cooperatively destroy wider and wider cognition-related cortical areas. In parallel, Aβ42-os•CaSR signals also elicit an excess production and secretion of nitric oxide and vascular endothelial growth factor-A from astrocytes, of Aβ42-os and myelin basic protein from oligodendrocytes, and of proinflammatory cytokines, nitric oxide and (likely) Aβ42-os from microglia. Activated astrocytes and microglia survive the toxic onslaught, whereas neurons and oligodendrocytes increasingly die. However, we have shown that highly selective allosteric CaSR antagonists (calcilytics), like NPS 2143 and NPS 89626, efficiently suppress all the neurotoxic effects Aβ42-os•CaSR signaling drives in cultured cortical untransformed human neurons and astrocytes. In fact, calcilytics increase Aβ42 proteolysis and discontinue the oversecretion of Aβ42-os, nitric oxide, and vascular endothelial growth factor-A from both astrocytes and neurons. Seemingly, calcilytics would also benefit the other types of glial cells and cerebrovascular cells otherwise damaged by the effects of Aβ42-os•CaSR signaling. Thus, given at amnestic minor cognitive impairment (aMCI) or initial symptomatic stages, calcilytics could prevent or terminate the propagation of LOAD neuropathology and preserve human neurons' viability and hence patients' cognitive abilities.
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Affiliation(s)
- Anna Chiarini
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
| | - Ubaldo Armato
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
| | - Daisong Liu
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
- Proteomics Laboratory, Institute for Burn Research, Third Military Medical UniversityChongqing, China
| | - Ilaria Dal Prà
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
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Noh JS, Pak HJ, Shin YJ, Riew TR, Park JH, Moon YW, Lee MY. Differential expression of the calcium-sensing receptor in the ischemic and border zones after transient focal cerebral ischemia in rats. J Chem Neuroanat 2015; 66-67:40-51. [DOI: 10.1016/j.jchemneu.2015.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/20/2015] [Accepted: 05/15/2015] [Indexed: 10/23/2022]
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Wang J, Tergel T, Chen J, Yang J, Kang Y, Qi Z. Arabidopsis transcriptional response to extracellular Ca2+ depletion involves a transient rise in cytosolic Ca2+. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:138-150. [PMID: 24850424 DOI: 10.1111/jipb.12218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/19/2014] [Indexed: 06/03/2023]
Abstract
Ecological evidence indicates a worldwide trend of dramatically decreased soil Ca(2+) levels caused by increased acid deposition and massive timber harvesting. Little is known about the genetic and cellular mechanism of plants' responses to Ca(2+) depletion. In this study, transcriptional profiling analysis helped identify multiple extracellular Ca(2+) ([Ca(2+) ]ext ) depletion-responsive genes in Arabidopsis thaliana L., many of which are involved in response to other environmental stresses. Interestingly, a group of genes encoding putative cytosolic Ca(2+) ([Ca(2+) ]cyt ) sensors were significantly upregulated, implying that [Ca(2+) ]cyt has a role in sensing [Ca(2+) ]ext depletion. Consistent with this observation, [Ca(2+) ]ext depletion stimulated a transient rise in [Ca(2+) ]cyt that was negatively influenced by [K(+) ]ext , suggesting the involvement of a membrane potential-sensitive component. The [Ca(2+) ]cyt response to [Ca(2+) ]ext depletion was significantly desensitized after the initial treatment, which is typical of a receptor-mediated signaling event. The response was insensitive to an animal Ca(2+) sensor antagonist, but was suppressed by neomycin, an inhibitor of phospholipase C. Gd(3+) , an inhibitor of Ca(2+) channels, suppressed the [Ca(2+) ]ext -triggered rise in [Ca(2+) ]cyt and downstream changes in gene expression. Taken together, this study demonstrates that [Ca(2+) ]cyt plays an important role in the putative receptor-mediated cellular and transcriptional response to [Ca(2+) ]ext depletion of plant cells.
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Affiliation(s)
- Jing Wang
- College of Life Sciences, Inner Mongolia University, Hohhot, 010021, China
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28
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Dal Prà I, Chiarini A, Pacchiana R, Gardenal E, Chakravarthy B, Whitfield JF, Armato U. Calcium-Sensing Receptors of Human Astrocyte-Neuron Teams: Amyloid-β-Driven Mediators and Therapeutic Targets of Alzheimer's Disease. Curr Neuropharmacol 2014; 12:353-64. [PMID: 25342943 PMCID: PMC4207075 DOI: 10.2174/1570159x12666140828214701] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/19/2014] [Accepted: 06/26/2014] [Indexed: 12/24/2022] Open
Abstract
It is generally assumed that the neuropathology of sporadic (late-onset or nonfamilial) Alzheimer’s disease (AD) is driven by the overproduction and spreading of first Amyloid-βx-42 (Aβ42) and later hyperphosphorylated (hp)-Tau oligomeric “infectious seeds”. Hitherto, only neurons were held to make and spread both oligomer types; astrocytes would just remove debris. However, we have recently shown that exogenous fibrillar or soluble Aβ peptides specifically bind and activate the Ca2+-sensing receptors (CaSRs) of untransformed human cortical adult astrocytes and postnatal neurons cultured in vitro driving them to produce, accrue, and secrete surplus endogenous Aβ42. While the Aβ-exposed neurons start dying, astrocytes survive and keep oversecreting Aβ42, nitric oxide (NO), and vascular endothelial growth factor (VEGF)-A. Thus astrocytes help neurons’ demise. Moreover, we have found that a highly selective allosteric CaSR agonist (“calcimimetic”), NPS R-568, mimics the just mentioned neurotoxic actions triggered by Aβ●CaSR signaling. Contrariwise, and most important, NPS 2143, a highly selective allosteric CaSR antagonist (“calcilytic”), fully suppresses all the Aβ●CaSR signaling-driven noxious actions. Altogether our findings suggest that the progression of AD neuropathology is promoted by unceasingly repeating cycles of accruing exogenous Aβ42 oligomers interacting with the CaSRs of swelling numbers of astrocyte-neuron teams thereby recruiting them to overrelease additional Aβ42 oligomers, VEGF-A, and NO. Calcilytics would beneficially break such Aβ/CaSR-driven vicious cycles and hence halt or at least slow the otherwise unstoppable spreading of AD neuropathology
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Affiliation(s)
- I Dal Prà
- Histology & Embryology Section, Department of Life & Reproduction Sciences, University of Verona Medical School, Verona, Venetia, Italy
| | - A Chiarini
- Histology & Embryology Section, Department of Life & Reproduction Sciences, University of Verona Medical School, Verona, Venetia, Italy
| | - R Pacchiana
- Histology & Embryology Section, Department of Life & Reproduction Sciences, University of Verona Medical School, Verona, Venetia, Italy
| | - E Gardenal
- Histology & Embryology Section, Department of Life & Reproduction Sciences, University of Verona Medical School, Verona, Venetia, Italy
| | - B Chakravarthy
- National Research Council of Canada, Ottawa, Ontario, Canada
| | - J F Whitfield
- National Research Council of Canada, Ottawa, Ontario, Canada
| | - U Armato
- Histology & Embryology Section, Department of Life & Reproduction Sciences, University of Verona Medical School, Verona, Venetia, Italy
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Emerging roles of the extracellular calcium-sensing receptor in nutrient sensing: control of taste modulation and intestinal hormone secretion. Br J Nutr 2014; 111 Suppl 1:S16-22. [PMID: 24382107 DOI: 10.1017/s0007114513002250] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The extracellular Ca-sensing receptor (CaSR) is a sensor for a number of key nutrients within the body, including Ca ions (Ca²⁺) and L-amino acids. The CaSR is expressed in a number of specialised cells within the gastrointestinal (GI) tract, and much work has been done to examine CaSR's role as a nutrient sensor in this system. This review article examines two emerging roles for the CaSR within the GI tract--as a mediator of kokumi taste modulation in taste cells and as a regulator of dietary hormone release in response to L-amino acids in the intestine.
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Ward DT, Mughal MZ, Ranieri M, Dvorak-Ewell MM, Valenti G, Riccardi D. Molecular and clinical analysis of a neonatal severe hyperparathyroidism case caused by a stop mutation in the calcium-sensing receptor extracellular domain representing in effect a human 'knockout'. Eur J Endocrinol 2013; 169:K1-7. [PMID: 23612447 DOI: 10.1530/eje-13-0094] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Loss-of-function calcium-sensing receptor (CAR) mutations cause elevated parathyroid hormone (PTH) secretion and hypercalcaemia. Although full Car deletion is possible in mice, most human CAR mutations result from a single amino acid substitution that maintains partial function. However, here, we report a case of neonatal severe hyperparathyroidism (NSHPT) in which the truncated CaR lacks any transmembrane domain (CaR(R392X)), in effect a full CAR 'knockout'. CASE REPORT The infant (daughter of distant cousins) presented with hypercalcaemia (5.5-6 mmol/l corrected calcium (2.15-2.65)) and elevated PTH concentrations (650-950 pmol/l (12-81)) together with skeletal demineralisation. NSHPT was confirmed by CAR gene sequencing (homozygous c.1174C-to-T mutation) requiring total parathyroidectomy during which only two glands were located and removed, resulting in normalisation of her serum PTH/calcium levels. DESIGN AND METHODS The R392X stop codon was inserted into human CAR and the resulting mutant (CaR(R392X)) expressed transiently in HEK-293 cells. RESULTS CaR(R392X) expressed as a 54 kDa dimeric glycoprotein that was undetectable in conditioned medium or in the patient's urine. The membrane localisation observed for wild-type CaR in parathyroid gland and transfected HEK-293 cells was absent from the proband's parathyroid gland and from CaR(R392X)-transfected cells. Expression of the mutant was localised to endoplasmic reticulum consistent with its lack of functional activity. CONCLUSIONS Intriguingly, the patient remained normocalcaemic throughout childhood (2.5 mM corrected calcium, 11 pg/ml PTH (10-71), age 8 years) but exhibited mild asymptomatic hypocalcaemia at age 10 years, now treated with 1-hydroxycholecalciferol and Ca2+ supplementation. Despite representing a virtual CAR knockout, the patient displays no obvious pathologies beyond her calcium homeostatic dysfunction.
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Affiliation(s)
- D T Ward
- Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
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The Cav3-Kv4 complex acts as a calcium sensor to maintain inhibitory charge transfer during extracellular calcium fluctuations. J Neurosci 2013; 33:7811-24. [PMID: 23637173 DOI: 10.1523/jneurosci.5384-12.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synaptic transmission and neuronal excitability depend on the concentration of extracellular calcium ([Ca](o)), yet repetitive synaptic input is known to decrease [Ca](o) in numerous brain regions. In the cerebellar molecular layer, synaptic input reduces [Ca](o) by up to 0.4 mm in the vicinity of stellate cell interneurons and Purkinje cell dendrites. The mechanisms used to maintain network excitability and Purkinje cell output in the face of this rapid change in calcium gradient have remained an enigma. Here we use single and dual patch recordings in an in vitro slice preparation of Sprague Dawley rats to investigate the effects of physiological decreases in [Ca](o) on the excitability of cerebellar stellate cells and their inhibitory regulation of Purkinje cells. We find that a Ca(v)3-K(v)4 ion channel complex expressed in stellate cells acts as a calcium sensor that responds to a decrease in [Ca]o by dynamically adjusting stellate cell output to maintain inhibitory charge transfer to Purkinje cells. The Ca(v)3-K(v)4 complex thus enables an adaptive regulation of inhibitory input to Purkinje cells during fluctuations in [Ca](o), providing a homeostatic control mechanism to regulate Purkinje cell excitability during repetitive afferent activity.
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Abstract
The calcium sensing receptor (CaSR) is expressed by subpopulations of neuronal and glial cells throughout the brain and is activated by extracellular calcium [Formula: see text] . During development, the CaSR regulates neuronal cell growth and migration as well as oligodendroglial maturation and function. Emerging evidence suggests that in nerve terminals, CaSR is implicated in synaptic plasticity and neurotransmission. In this review, we analyze the roles attributed to CaSR in regulating diverse brain functions, including central regulation of body fluid composition and blood pressure. We also discuss the potential relevance of Ca(2+)-sensing in brain by other family C G protein-coupled receptors. Finally, evidence that the CaSR contributes to the pathogenesis of various brain disorders raises the possibility that pharmacological modulators of the CaSR may have therapeutic benefit.
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Affiliation(s)
- Martial Ruat
- CNRS-UPR-3294, Laboratory of Neurobiology and Development, Institute of Neurobiology, Alfred Fessard IFR2118, Signal Transduction and Developmental Neuropharmacology Team, 1 Avenue de la Terrasse, F-91198, Gif-sur-Yvette, France.
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Sarkar P, Kumar S. Calcium sensing receptor modulation for cancer therapy. Asian Pac J Cancer Prev 2013; 13:3561-8. [PMID: 23098435 DOI: 10.7314/apjcp.2012.13.8.3561] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The calcium sensing receptor (CaSR) is a member of the largest family of cell surface receptors, the G protein-coupled receptors involved in calcium homeostasis. The role of the CaSR in neoplasia appears to be homeostatic; loss of normal CaSR-induced response to extracellular calcium is observed in cancers of the colon and ovary, while increased release of PTHrP is observed in cancers of the breast, prostate and Leydig cells. Currently CaSR can be considered as a molecule that can either promote or prevent tumor growth depending on the type of cancer. Therefore, recognition of the multifaceted role of CaSR in gliomas and other malignant tumors in general is fundamental to elucidating the mechanisms of tumor progression and the development of novel therapeutic agents. Emphasis should be placed on development of drug-targeting methods to modulate CaSR activity in cancer cells.
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Affiliation(s)
- Puja Sarkar
- IGNOU-I2IT Centre of Excellence for Advanced Education and Research, Pune, Maharashtra, India
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34
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Liu XL, Lu YS, Gao JY, Marshall C, Xiao M, Miao DS, Karaplis A, Goltzman D, Ding J. Calcium Sensing Receptor Absence Delays Postnatal Brain Development via Direct and Indirect Mechanisms. Mol Neurobiol 2013; 48:590-600. [DOI: 10.1007/s12035-013-8448-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/18/2013] [Indexed: 12/22/2022]
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Abstract
Pancreatic β cells secrete insulin, the body's only hormone capable of lowering plasma glucose levels. Impaired or insufficient insulin secretion results in diabetes mellitus. The β cell is electrically excitable; in response to an elevation of glucose, it depolarizes and starts generating action potentials. The electrophysiology of mouse β cells and the cell's role in insulin secretion have been extensively investigated. More recently, similar studies have been performed on human β cells. These studies have revealed numerous and important differences between human and rodent β cells. Here we discuss the properties of human pancreatic β cells: their glucose sensing, the ion channel complement underlying glucose-induced electrical activity that culminates in exocytotic release of insulin, the cellular control of exocytosis, and the modulation of insulin secretion by circulating hormones and locally released neurotransmitters. Finally, we consider the pathophysiology of insulin secretion and the interactions between genetics and environmental factors that may explain the current diabetes epidemic.
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Affiliation(s)
- Patrik Rorsman
- Oxford Center for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LJ, United Kingdom.
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Bandyopadhyay BC, Swaim WD, Sarkar A, Liu X, Ambudkar IS. Extracellular Ca(2+) sensing in salivary ductal cells. J Biol Chem 2012; 287:30305-16. [PMID: 22778254 DOI: 10.1074/jbc.m112.394122] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ca(2+) is secreted from the salivary acinar cells as an ionic constituent of primary saliva. Ions such as Na(+) and Cl(-) get reabsorbed whereas primary saliva flows through the salivary ductal system. Although earlier studies have shown that salivary [Ca(2+)] decreases as it flows down the ductal tree into the oral cavity, ductal reabsorption of Ca(2+) remains enigmatic. Here we report a potential role for the G protein-coupled receptor, calcium-sensing receptor (CSR), in the regulation of Ca(2+) reabsorption by salivary gland ducts. Our data show that CSR is present in the apical region of ductal cells where it is co-localized with transient receptor potential canonical 3 (TRPC3). CSR is activated in isolated salivary gland ducts as well as a ductal cell line (SMIE) by altering extracellular [Ca(2+)] or by aromatic amino acid, L-phenylalanine (L-Phe, endogenous component of saliva), as well as neomycin. CSR activation leads to Ca(2+) influx that, in polarized cells grown on a filter support, is initiated in the luminal region. We show that TRPC3 contributes to Ca(2+) entry triggered by CSR activation. Further, stimulation of CSR in SMIE cells enhances the CSR-TRPC3 association as well as surface expression of TRPC3. Together our findings suggest that CSR could serve as a Ca(2+) sensor in the luminal membrane of salivary gland ducts and regulate reabsorption of [Ca(2+)] from the saliva via TRPC3, thus contributing to maintenance of salivary [Ca(2+)]. CSR could therefore be a potentially important protective mechanism against formation of salivary gland stones (sialolithiasis) and infection (sialoadenitis).
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Affiliation(s)
- Bidhan C Bandyopadhyay
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, DC 20422, USA.
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37
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Yamamura A, Guo Q, Yamamura H, Zimnicka AM, Pohl NM, Smith KA, Fernandez RA, Zeifman A, Makino A, Dong H, Yuan JXJ. Enhanced Ca(2+)-sensing receptor function in idiopathic pulmonary arterial hypertension. Circ Res 2012; 111:469-81. [PMID: 22730443 DOI: 10.1161/circresaha.112.266361] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
RATIONALE A rise in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary arterial smooth muscle cells (PASMC) is an important stimulus for pulmonary vasoconstriction and vascular remodeling. Increased resting [Ca(2+)](cyt) and enhanced Ca(2+) influx have been implicated in PASMC from patients with idiopathic pulmonary arterial hypertension (IPAH). OBJECTIVE We examined whether the extracellular Ca(2+)-sensing receptor (CaSR) is involved in the enhanced Ca(2+) influx and proliferation in IPAH-PASMC and whether blockade of CaSR inhibits experimental pulmonary hypertension. METHODS AND RESULTS In normal PASMC superfused with Ca(2+)-free solution, addition of 2.2 mmol/L Ca(2+) to the perfusate had little effect on [Ca(2+)](cyt). In IPAH-PASMC, however, restoration of extracellular Ca(2+) induced a significant increase in [Ca(2+)](cyt). Extracellular application of spermine also markedly raised [Ca(2+)](cyt) in IPAH-PASMC but not in normal PASMC. The calcimimetic R568 enhanced, whereas the calcilytic NPS 2143 attenuated, the extracellular Ca(2+)-induced [Ca(2+)](cyt) rise in IPAH-PASMC. Furthermore, the protein expression level of CaSR in IPAH-PASMC was greater than in normal PASMC; knockdown of CaSR in IPAH-PASMC with siRNA attenuated the extracellular Ca(2+)-mediated [Ca(2+)](cyt) increase and inhibited IPAH-PASMC proliferation. Using animal models of pulmonary hypertension, our data showed that CaSR expression and function were both enhanced in PASMC, whereas intraperitoneal injection of the calcilytic NPS 2143 prevented the development of pulmonary hypertension and right ventricular hypertrophy in rats injected with monocrotaline and mice exposed to hypoxia. CONCLUSIONS The extracellular Ca(2+)-induced increase in [Ca(2+)](cyt) due to upregulated CaSR is a novel pathogenic mechanism contributing to the augmented Ca(2+) influx and excessive PASMC proliferation in patients and animals with pulmonary arterial hypertension.
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Affiliation(s)
- Aya Yamamura
- Kinjo Gakuin University School of Pharmacy, Nagoya, Japan
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Leclerc C, Néant I, Moreau M. The calcium: an early signal that initiates the formation of the nervous system during embryogenesis. Front Mol Neurosci 2012; 5:3. [PMID: 22593733 PMCID: PMC3351002 DOI: 10.3389/fnmol.2012.00064] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/25/2012] [Indexed: 01/19/2023] Open
Abstract
The calcium (Ca(2+)) signaling pathways have crucial roles in development from fertilization through differentiation to organogenesis. In the nervous system, Ca(2+) signals are important regulators for various neuronal functions, including formation and maturation of neuronal circuits and long-term memory. However, Ca(2+) signals are also involved in the earliest steps of neurogenesis including neural induction, differentiation of neural progenitors into neurons, and the neuro-glial switch. This review examines when and how Ca(2+) signals are generated during each of these steps with examples taken from in vivo studies in vertebrate embryos and from in vitro assays using embryonic and neural stem cells (NSCs). During the early phases of neurogenesis few investigations have been performed to study the downstream targets of Ca(2+) which posses EF-hand in their structure. This opens an entire field of research. We also discuss the highly specific nature of the Ca(2+) signaling pathway and its interaction with the other signaling pathways involved in early neural development.
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Affiliation(s)
- Catherine Leclerc
- Centre de Biologie du Développement, Université Toulouse III, CNRS UMR 5547Toulouse, France and GDRE n731, “Ca toolkit coded proteins as drug targets in animal and plant cells”
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Riccardi D, Kemp PJ. The Calcium-Sensing Receptor Beyond Extracellular Calcium Homeostasis: Conception, Development, Adult Physiology, and Disease. Annu Rev Physiol 2012; 74:271-97. [DOI: 10.1146/annurev-physiol-020911-153318] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Daniela Riccardi
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Cardiff, CF10 3AX, United Kingdom; ,
| | - Paul J. Kemp
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Cardiff, CF10 3AX, United Kingdom; ,
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40
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Davey AE, Leach K, Valant C, Conigrave AD, Sexton PM, Christopoulos A. Positive and negative allosteric modulators promote biased signaling at the calcium-sensing receptor. Endocrinology 2012; 153:1232-41. [PMID: 22210744 DOI: 10.1210/en.2011-1426] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The calcium-sensing receptor (CaSR) is a G protein-coupled receptor whose function can be allosterically modulated in a positive or negative manner by calcimimetics or calcilytics, respectively. Indeed, the second-generation calcimimetic, cinacalcet, has proven clinically useful in the treatment of chronic kidney disease patients with secondary hyperparathyroidism but is not widely used in earlier stages of renal disease due to the potential to predispose such patients to hypocalcaemia and hyperphosphatemia. The development of a biased CaSR ligand that is more selective for specific signaling pathway(s) leading only to beneficial effects may overcome this limitation. The detection of such stimulus-bias at a G protein-coupled receptor requires investigation across multiple signaling pathways and the development of methods to quantify the effects of allosteric ligands on orthosteric ligand affinity and cooperativity at each pathway. In the current study, we determined the effects of the calcimimetics, NPS-R568 or cinacalcet, and the calcilytic, NPS-2143, on Ca(o)(2+)-mediated intracellular Ca(2+) mobilization, ERK1/2 phosphorylation, and plasma membrane ruffling in a stably transfected human embryonic kidney 293-TREx c-myc-CaSR cell line and applied a novel analytical model to quantify these modulator effects. We present quantitative evidence for the generation of stimulus bias by both positive and negative allosteric modulators of the CaSR, manifested as greater allosteric modulation of intracellular Ca(2+) mobilization relative to ERK1/2 phosphorylation, and a higher affinity of the modulators for the state of the CaSR mediating plasma membrane ruffling relative to the other two pathways. Our findings provide the first evidence that an allosteric modulator used in clinical practice exhibits stimulus bias.
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Affiliation(s)
- Anna E Davey
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia
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41
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Amin A, Murphy KG. Nutritional sensing and its utility in treating obesity. Expert Rev Endocrinol Metab 2012; 7:209-221. [PMID: 30764012 DOI: 10.1586/eem.12.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Obesity remains a major worldwide health problem, with current medical treatments being poorly effective. Nutrient sensing allows organs such as the GI tract and the brain to recognize and respond to fuel substrates such as carbohydrates, protein and fats. Specialized neural and hormonal pathways exist to facilitate and regulate these chemosensory mechanisms. Manipulation of factors involved in either central or peripheral chemosensory pathways may provide possible targets for the manipulation of appetite. However, further research is required to assess the utility of this approach to developing novel anti-obesity agents.
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Affiliation(s)
- Anjali Amin
- a Section of Investigative Medicine, Faculty of Medicine, Imperial College London, 6th Floor, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Kevin G Murphy
- b Section of Investigative Medicine, Faculty of Medicine, Imperial College London, 6th Floor, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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42
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Huang Y, Cavanaugh A, Breitwieser GE. Regulation of stability and trafficking of calcium-sensing receptors by pharmacologic chaperones. ADVANCES IN PHARMACOLOGY 2012; 62:143-73. [PMID: 21907909 DOI: 10.1016/b978-0-12-385952-5.00007-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Gain- or loss-of-function mutations and polymorphisms of the calcium-sensing receptor (CaSR) cause Ca(2+) handling diseases. Altered expression and/or signaling of wild-type CaSR can also contribute to pathology. Recent studies have demonstrated that a significant proportion of mutations cause altered targeting and/or trafficking of CaSR to the plasma membrane. Pharmacological approaches to rescue of CaSR function include treatment with allosteric modulators, which potentiate the effects of the orthosteric agonist Ca(2+). Dissection of the mechanism(s) contributing to allosteric agonist-mediated rescue of loss-of-function CaSR mutants has demonstrated pharmacologic chaperone actions coincident with CaSR biosynthesis. The distinctive responses to the allosteric agonist (NPS R-568), which promotes CaSR stability, and the allosteric antagonist (NPS 2143), which promotes CaSR degradation, have led to a model for a conformational checkpoint during CaSR biosynthesis. The conformational checkpoint would "tune" CaSR biosynthesis to cellular signaling state. Navigation of a distinct checkpoint for endoplasmic release can also be augmented by pharmacologic chaperones. The diverse, post-endoplasmic reticulum quality control site(s) for pharmacologic chaperone modulation of CaSR stability and trafficking redefines the role(s) of allosteric modulators in regulation of overall GPCR function.
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Affiliation(s)
- Ying Huang
- Cancer Drug Research Laboratory, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada
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Abstract
The calcium-sensing receptor (CaR) is the key controller of extracellular calcium (Ca(2+)(o)) homeostasis via its regulation of parathyroid hormone (PTH) secretion and renal Ca(2+) reabsorption. The CaR-selective calcimimetic drug Cinacalcet stimulates the CaR to suppress PTH secretion in chronic kidney disease and represents the world's first clinically available receptor positive allosteric modulator (PAM). Negative CaR allosteric modulators (NAMs), known as calcilytics, can increase PTH secretion and are being investigated as possible bone anabolic treatments against age-related osteoporosis. Here we address the current state of development and clinical use of a series of positive and negative CaR modulators. In addition, clinical CaR mutations and transgenic mice carrying tissue-specific CaR deletions have provided a novel understanding of the relative functional importance of CaR in both calciotropic tissues and those elsewhere in the body. The development of CaR-selective modulators and signalling reagents have provided us with a more detailed appreciation of how the CaR signals in vivo. Thus, both of these areas of CaR research will be reviewed.
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Affiliation(s)
- Donald T Ward
- Faculty of Life Sciences, The University of ManchesterManchester, UK
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Signaling through the extracellular calcium-sensing receptor (CaSR). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:103-42. [PMID: 22453940 DOI: 10.1007/978-94-007-2888-2_5] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The extracellular calcium ([Formula: see text])-sensing receptor (CaSR) was the first GPCR identified whose principal physiological ligand is an ion, namely extracellular Ca(2+). It maintains the near constancy of [Formula: see text] that complex organisms require to ensure normal cellular function. A wealth of information has accumulated over the past two decades about the CaSR's structure and function, its role in diseases and CaSR-based therapeutics. This review briefly describes the CaSR and key features of its structure and function, then discusses the extracellular signals modulating its activity, provides an overview of the intracellular signaling pathways that it controls, and, finally, briefly describes CaSR signaling both in tissues participating in [Formula: see text] homeostasis as well as those that do not. Factors controlling CaSR signaling include various factors affecting the expression of the CaSR gene as well as modulation of its trafficking to and from the cell surface. The dimeric cell surface CaSR, in turn, links to various heterotrimeric and small molecular weight G proteins to regulate intracellular second messengers, lipid kinases, various protein kinases, and transcription factors that are part of the machinery enabling the receptor to modulate the functions of the wide variety of cells in which it is expressed. CaSR signaling is impacted by its interactions with several binding partners in addition to signaling elements per se (i.e., G proteins), including filamin-A and caveolin-1. These latter two proteins act as scaffolds that bind signaling components and other key cellular elements (e.g., the cytoskeleton). Thus CaSR signaling likely does not take place randomly throughout the cell, but is compartmentalized and organized so as to facilitate the interaction of the receptor with its various signaling pathways.
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Calcilytics: antagonists of the calcium-sensing receptor for the treatment of osteoporosis. Future Med Chem 2011; 3:535-47. [PMID: 21526895 DOI: 10.4155/fmc.11.17] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The only bone anabolic agents currently available on the market are based on the parathyroid hormone (PTH). Secretion of endogenous PTH is controlled by a calcium-sensing receptor at the surface of the parathyroid glands. Antagonists of this receptor (calcilytics) induce the release of the hormone. Provided the effect of the calcilytic is of short duration, a bone anabolic effect should also result. Although the first calcilytic series became known approximately 10 years ago, the number of different structural types is still small today. This article outlines the quest from hits to potent development candidates of all relevant calcilytic series currently known. Even after the front-runners unexpectedly failed in the clinic, the approach for an oral alternative to parenteral PTH remains highly attractive.
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Leclerc C, Néant I, Moreau M. Early neural development in vertebrates is also a matter of calcium. Biochimie 2011; 93:2102-11. [PMID: 21742011 DOI: 10.1016/j.biochi.2011.06.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/24/2011] [Indexed: 12/19/2022]
Abstract
The calcium (Ca(2+)) signaling pathways have crucial roles in development from fertilization through differentiation to organogenesis. In the nervous system, Ca(2+) signals are important regulators for various neuronal functions, including formation and maturation of neuronal circuits and long-term memory. However, Ca(2+) signals are mainly involved in the earliest steps of nervous system development including neural induction, differentiation of neural progenitors into neurons, and the neuro-glial switch. This review examines when and how Ca(2+) signals are generated during each of these steps with examples taken from in vivo studies in vertebrate embryos and from in vitro assays using embryonic and neural stem cells. Also discussed is the highly specific nature of the Ca(2+) signaling pathway and its interaction with the other signaling pathways involved in early neural development.
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Affiliation(s)
- Catherine Leclerc
- Centre de Biologie du Développement, UMR CNRS 5547 and GDR 2688, Université de Toulouse, 118 route de Narbonne, Toulouse, France.
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