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Orr HT. Cholecystokinin Activation of Cholecystokinin 1 Receptors: a Purkinje Cell Neuroprotective Pathway. CEREBELLUM (LONDON, ENGLAND) 2022:10.1007/s12311-022-01428-x. [PMID: 35733029 DOI: 10.1007/s12311-022-01428-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
This is a summary of the virtual presentation given at the 2021 meeting of the Society for Research on the Cerebellum and Ataxias, https://www.meetings.be/SRCA2021/ , where the therapeutic potential of the CCK-CCK1R pathway for treating diseases involving Purkinje cell degeneration was presented. Spinocerebellar ataxia type 1 (SCA1) is one of a group of almost 50 genetic diseases characterized by the degeneration of cerebellar Purkinje cells. The SCA1 Pcp2-ATXN1[30Q]D776 mouse model displays ataxia, i.e. Purkinje cell dysfunction, but lacks progressive Purkinje cell degeneration. RNA-seq revealed increased expression of cholecystokinin (CCK) in cerebella of Pcp2-ATXN1[30Q]D776 mice. Importantly, the absence of Cck1 receptor (CCK1R) in Pcp2-ATXN1[30Q]D776 mice conferred a progressive degenerative disease with Purkinje cell loss. Administration of a CCK1R agonist to Pcp2-AXTN1[82Q] mice reduced Purkinje cell pathology and associated deficits in motor performance. In addition, administration of the CCK1R agonist improved motor performance of Pcp2-ATXN2[127Q] SCA2 mice. Furthermore, CCK1R activation corrected mTORC1 signaling and improved the expression of calbindin in the cerebella of AXTN1[82Q] and ATXN2[127Q] mice. These results support the Cck-Cck1R pathway is a potential therapeutic target for the treatment of diseases involving Purkinje neuron degeneration.
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Affiliation(s)
- Harry T Orr
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA.
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Miedzybrodzka EL, Gribble FM, Reimann F. Targeting the Enteroendocrine System for Treatment of Obesity. Handb Exp Pharmacol 2022; 274:487-513. [PMID: 35419620 DOI: 10.1007/164_2022_583] [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] [Indexed: 11/27/2022]
Abstract
Mimetics of the anorexigenic gut hormone glucagon-like peptide 1 (GLP-1) were originally developed as insulinotropic anti-diabetic drugs but also evoke significant weight loss, leading to their recent approval as obesity therapeutics. Co-activation of receptors for GLP-1 and other gut hormones which reduce food intake - peptide YY (PYY3-36), cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP) - is now being explored clinically to enhance efficacy. An alternative approach involves pharmacologically stimulating endogenous secretion of these hormones from enteroendocrine cells (EECs) to recapitulate the metabolic consequences of bariatric surgery, where highly elevated postprandial levels of GLP-1 and PYY3-36 are thought to contribute to improved glycaemia and weight loss.
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Affiliation(s)
- Emily L Miedzybrodzka
- Wellcome Trust - MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Fiona M Gribble
- Wellcome Trust - MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
| | - Frank Reimann
- Wellcome Trust - MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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Wozniak EAL, Chen Z, Paul S, Yang P, Figueroa KP, Friedrich J, Tschumperlin T, Berken M, Ingram M, Henzler C, Pulst SM, Orr HT. Cholecystokinin 1 receptor activation restores normal mTORC1 signaling and is protective to Purkinje cells of SCA mice. Cell Rep 2021; 37:109831. [PMID: 34644575 PMCID: PMC8916043 DOI: 10.1016/j.celrep.2021.109831] [Citation(s) in RCA: 9] [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: 02/22/2021] [Revised: 07/23/2021] [Accepted: 09/22/2021] [Indexed: 12/20/2022] Open
Abstract
Spinocerebellar ataxias (SCAs) are a group of genetic diseases characterized by progressive ataxia and neurodegeneration, often in cerebellar Purkinje neurons. A SCA1 mouse model, Pcp2-ATXN1[30Q]D776, has severe ataxia in absence of progressive Purkinje neuron degeneration and death. Previous RNA-seq analyses identify cerebellar upregulation of the peptide hormone cholecystokinin (Cck) in Pcp2-ATXN1[30Q]D776 mice. Importantly, absence of Cck1 receptor (Cck1R) in Pcp2-ATXN1[30Q]D776 mice confers a progressive disease with Purkinje neuron death. Administration of a Cck1R agonist, A71623, to Pcp2-ATXN1[30Q]D776;Cck-/- and Pcp2-AXTN1[82Q] mice dampens Purkinje neuron pathology and associated deficits in motor performance. In addition, A71623 administration improves motor performance of Pcp2-ATXN2[127Q] SCA2 mice. Moreover, the Cck1R agonist A71623 corrects mTORC1 signaling and improves expression of calbindin in cerebella of AXTN1[82Q] and ATXN2[127Q] mice. These results indicate that manipulation of the Cck-Cck1R pathway is a potential therapeutic target for treatment of diseases involving Purkinje neuron degeneration.
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Affiliation(s)
- Emily A L Wozniak
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zhao Chen
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, UT 84112, USA
| | - Praseuth Yang
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Karla P Figueroa
- Department of Neurology, University of Utah, Salt Lake City, UT 84112, USA
| | - Jill Friedrich
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tyler Tschumperlin
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Michael Berken
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Melissa Ingram
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Christine Henzler
- RISS Bioinformatics, Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
| | - Harry T Orr
- Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA.
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Miller LJ, Harikumar KG, Wootten D, Sexton PM. Roles of Cholecystokinin in the Nutritional Continuum. Physiology and Potential Therapeutics. Front Endocrinol (Lausanne) 2021; 12:684656. [PMID: 34149622 PMCID: PMC8206557 DOI: 10.3389/fendo.2021.684656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/17/2021] [Indexed: 11/13/2022] Open
Abstract
Cholecystokinin is a gastrointestinal peptide hormone with important roles in metabolic physiology and the maintenance of normal nutritional status, as well as potential roles in the prevention and management of obesity, currently one of the dominant causes of direct or indirect morbidity and mortality. In this review, we discuss the roles of this hormone and its receptors in maintaining nutritional homeostasis, with a particular focus on appetite control. Targeting this action led to the development of full agonists of the type 1 cholecystokinin receptor that have so far failed in clinical trials for obesity. The possible reasons for clinical failure are discussed, along with alternative pharmacologic strategies to target this receptor for prevention and management of obesity, including development of biased agonists and allosteric modulators. Cellular cholesterol is a natural modulator of the type 1 cholecystokinin receptor, with elevated levels disrupting normal stimulus-activity coupling. The molecular basis for this is discussed, along with strategies to overcome this challenge with a corrective positive allosteric modulator. There remains substantial scope for development of drugs to target the type 1 cholecystokinin receptor with these new pharmacologic strategies and such drugs may provide new approaches for treatment of obesity.
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Affiliation(s)
- Laurence J. Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ, United States
- *Correspondence: Laurence J. Miller,
| | - Kaleeckal G. Harikumar
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ, United States
| | - Denise Wootten
- Drug Discovery Biology theme, Monash Institute for Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Patrick M. Sexton
- Drug Discovery Biology theme, Monash Institute for Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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Abás S, Rodríguez-Arévalo S, Bagán A, Griñán-Ferré C, Vasilopoulou F, Brocos-Mosquera I, Muguruza C, Pérez B, Molins E, Luque FJ, Pérez-Lozano P, de Jonghe S, Daelemans D, Naesens L, Brea J, Loza MI, Hernández-Hernández E, García-Sevilla JA, García-Fuster MJ, Radan M, Djikic T, Nikolic K, Pallàs M, Callado LF, Escolano C. Bicyclic α-Iminophosphonates as High Affinity Imidazoline I2 Receptor Ligands for Alzheimer’s Disease. J Med Chem 2020; 63:3610-3633. [DOI: 10.1021/acs.jmedchem.9b02080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sònia Abás
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Sergio Rodríguez-Arévalo
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Andrea Bagán
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Christian Griñán-Ferré
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Foteini Vasilopoulou
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Iria Brocos-Mosquera
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Carolina Muguruza
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Belén Pérez
- Department of Pharmacology, Therapeutic and Toxicology, Autonomous University of Barcelona, E-08193 Barcelona, Spain
| | - Elies Molins
- Institut de Ciència de Materials de Barcelona (CSIC), Campus UAB, E-08193 Cerdanyola, Spain
| | - F. Javier Luque
- Department of Nutrition, Food Sciences and Gastronomy, School of Pharmacy and Food Sciences, Institute of Biomedicine (IBUB), and Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, E-08921 Santa Coloma de Gramanet, Spain
| | - Pilar Pérez-Lozano
- Unit of Pharmaceutical Technology, Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Steven de Jonghe
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Dirk Daelemans
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Lieve Naesens
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - José Brea
- Innopharma screening platform, BioFarma research group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M. Isabel Loza
- Innopharma screening platform, BioFarma research group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Elena Hernández-Hernández
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Jesús A. García-Sevilla
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - M. Julia García-Fuster
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Milica Radan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Teodora Djikic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Katarina Nikolic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Mercè Pallàs
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Luis F. Callado
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Carmen Escolano
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
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Kissileff HR, Gordon RJ, Thornton JC, Laferrère B, Albu J, Pi-Sunyer X, Geliebter A. Combined effects of cholecystokinin-8 and gastric distension on food intake in humans. Am J Physiol Regul Integr Comp Physiol 2019; 317:R39-R48. [PMID: 30916576 DOI: 10.1152/ajpregu.00339.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In a previous study (Kissileff HR, Carretta JC, Geliebter A, Pi-Sunyer FX. Am J Physiol Regul Integr Comp Physiol 285: R992-R998, 2003), when subthreshold gastric distension (300 ml) and a low dose of cholecystokinin octapeptide (CCK-8) (112 ng/min for 21 min) were concurrently administered to human participants, intake of a test meal was significantly reduced. However, the supra-additive interaction of CCK-8 and gastric distension was not significant. The purpose of the present study was to determine whether a significant interaction would be obtained when CCK-8 and gastric distension were each increased by 50% above levels used in the previous study. Twelve normal-weight, healthy participants were tested four times each with either CCK-8 (168 ng/min for 30 min) or saline infusion crossed with gastric distension (450 ml) or no distension. The combination of CCK-8 and gastric distension reduced food intake by a mean of 405 ± 86 g (SE) in comparison with the saline nondistension condition (P < 0.001), which is a 51% reduction. Although there were some differences in the protocols, the combined effect was double that seen in the previous study. Although the interactive effect was larger [118 ± 109 g (SE)] than it was previously [73 ± 86 (SE)], it was not significant (P = 0.29). There were also reports of a short-lived sick feeling after CCK-8, with and without distension, that was not observed in the previous study. Thus the combination of CCK-8 at 1.5 times threshold and gastric distension at 450 ml (increased from 300 ml) resulted in a combined effect to reduce food intake, which was also 1.5 times its previous value, and thus appears linear.
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Affiliation(s)
- Harry R Kissileff
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - Rebecca J Gordon
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - John C Thornton
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - Blandine Laferrère
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - Jeanine Albu
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - X Pi-Sunyer
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
| | - Allan Geliebter
- New York Obesity Nutrition Research Center, Columbia University, Mount Sinai St. Luke's Hospital , New York, New York
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Caffeine – rich infusion from Cola nitida (kola nut) inhibits major carbohydrate catabolic enzymes; abates redox imbalance; and modulates oxidative dysregulated metabolic pathways and metabolites in Fe2+-induced hepatic toxicity. Biomed Pharmacother 2017; 96:1065-1074. [DOI: 10.1016/j.biopha.2017.11.120] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/05/2017] [Accepted: 11/27/2017] [Indexed: 12/11/2022] Open
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Jiang HN, Li Y, Cui ZJ. Photodynamic Physiology-Photonanomanipulations in Cellular Physiology with Protein Photosensitizers. Front Physiol 2017; 8:191. [PMID: 28421000 PMCID: PMC5378799 DOI: 10.3389/fphys.2017.00191] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/14/2017] [Indexed: 02/05/2023] Open
Abstract
Singlet oxygen generated in a type II photodynamic action, due to its limited lifetime (1 μs) and reactive distance (<10 nm), could regulate live cell function nanoscopically. The genetically-encoded protein photosensitizers (engineered fluorescent proteins such as KillerRed, TagRFP, and flavin-binding proteins such as miniSOG, Pp2FbFPL30M) could be expressed in a cell type- and/or subcellular organelle-specific manner for targeted protein photo-oxidative activation/desensitization. The newly emerged active illumination technique provides an additional level of specificity. Typical examples of photodynamic activation include permanent activation of G protein-coupled receptor CCK1 and photodynamic activation of ionic channel TRPA1. Protein photosensitizers have been used to photodynamically modulate major cellular functions (such as neurotransmitter release and gene transcription) and animal behavior. Protein photosensitizers are increasingly used in photon-driven nanomanipulation in cell physiology research.
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Duca FA, Bauer PV, Hamr SC, Lam TKT. Glucoregulatory Relevance of Small Intestinal Nutrient Sensing in Physiology, Bariatric Surgery, and Pharmacology. Cell Metab 2015. [PMID: 26212718 DOI: 10.1016/j.cmet.2015.07.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Emerging evidence suggests the gastrointestinal tract plays an important glucoregulatory role. In this perspective, we first review how the intestine senses ingested nutrients, initiating crucial negative feedback mechanisms through a gut-brain neuronal axis to regulate glycemia, mainly via reduction in hepatic glucose production. We then highlight how intestinal energy sensory mechanisms are responsible for the glucose-lowering effects of bariatric surgery, specifically duodenal-jejunal bypass, and the antidiabetic agents metformin and resveratrol. A better understanding of these pathways lays the groundwork for intestinally targeted drug therapy for the treatment of diabetes.
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Affiliation(s)
- Frank A Duca
- Toronto General Research Institute and Department of Medicine, UHN, Toronto, ON M5G 1L7, Canada
| | - Paige V Bauer
- Toronto General Research Institute and Department of Medicine, UHN, Toronto, ON M5G 1L7, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sophie C Hamr
- Toronto General Research Institute and Department of Medicine, UHN, Toronto, ON M5G 1L7, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Tony K T Lam
- Toronto General Research Institute and Department of Medicine, UHN, Toronto, ON M5G 1L7, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada; Banting and Best Diabetes Centre, University of Toronto, Toronto, ON M5G 2C4, Canada.
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Tripathi S, Flobak Å, Chawla K, Baudot A, Bruland T, Thommesen L, Kuiper M, Lægreid A. The gastrin and cholecystokinin receptors mediated signaling network: a scaffold for data analysis and new hypotheses on regulatory mechanisms. BMC SYSTEMS BIOLOGY 2015. [PMID: 26205660 PMCID: PMC4513977 DOI: 10.1186/s12918-015-0181-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background The gastrointestinal peptide hormones cholecystokinin and gastrin exert their biological functions via cholecystokinin receptors CCK1R and CCK2R respectively. Gastrin, a central regulator of gastric acid secretion, is involved in growth and differentiation of gastric and colonic mucosa, and there is evidence that it is pro-carcinogenic. Cholecystokinin is implicated in digestion, appetite control and body weight regulation, and may play a role in several digestive disorders. Results We performed a detailed analysis of the literature reporting experimental evidence on signaling pathways triggered by CCK1R and CCK2R, in order to create a comprehensive map of gastrin and cholecystokinin-mediated intracellular signaling cascades. The resulting signaling map captures 413 reactions involving 530 molecular species, and incorporates the currently available knowledge into one integrated signaling network. The decomposition of the signaling map into sub-networks revealed 18 modules that represent higher-level structures of the signaling map. These modules allow a more compact mapping of intracellular signaling reactions to known cell behavioral outcomes such as proliferation, migration and apoptosis. The integration of large-scale protein-protein interaction data to this literature-based signaling map in combination with topological analyses allowed us to identify 70 proteins able to increase the compactness of the map. These proteins represent experimentally testable hypotheses for gaining new knowledge on gastrin- and cholecystokinin receptor signaling. The CCKR map is freely available both in a downloadable, machine-readable SBML-compatible format and as a web resource through PAYAO (http://sblab.celldesigner.org:18080/Payao11/bin/). Conclusion We have demonstrated how a literature-based CCKR signaling map together with its protein interaction extensions can be analyzed to generate new hypotheses on molecular mechanisms involved in gastrin- and cholecystokinin-mediated regulation of cellular processes. Electronic supplementary material The online version of this article (doi:10.1186/s12918-015-0181-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sushil Tripathi
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
| | - Åsmund Flobak
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
| | - Konika Chawla
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
| | - Anaïs Baudot
- I2M, Marseilles Institute of Mathematics CNRS - AMU, Case 907, 13288, Marseille, Cedex 9, France.
| | - Torunn Bruland
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
| | - Liv Thommesen
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway. .,Department of Technology, Sør-Trøndelag University College, N-7004, Trondheim, Norway.
| | - Martin Kuiper
- Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway.
| | - Astrid Lægreid
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway. .,Institute of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7489, Trondheim, Norway.
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Differential expression of cholecystokinin A receptor in gallbladder cancer in the young and elderly suggests two subsets of the same disease? BIOMED RESEARCH INTERNATIONAL 2014; 2014:625695. [PMID: 25025063 PMCID: PMC4082861 DOI: 10.1155/2014/625695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/27/2014] [Accepted: 05/27/2014] [Indexed: 12/18/2022]
Abstract
Background. Cholecystokinin type A receptor (CCKAR) is known to be overexpressed in variety of human malignancies but information regarding its expression in gallbladder cancer (GBC) is limited. Attempts were now made to investigate expression pattern of CCKAR mRNA and protein in controls and GBC patients and correlate it with various clinicopathological parameters following surgical resection. Materials and Methods. Gallbladder tissue samples from 64 subjects (GBC: 39; control: 25) were studied. Expression of CCKAR mRNA was evaluated by reverse transcriptase-polymerase chain reaction and confirmed using real-time polymerase chain reaction. Protein expression was studied by enzyme-linked immunosorbent assay. Results. Significantly higher expression of CCKAR mRNA (P < 0.0001) and protein (P < 0.0001) was observed in GBC tissues. Overexpression was also observed for stage III and in moderately and poorly differentiated tumors. When the clinicopathological parameters were compared, we found age dependent decrease in CCKAR expression. Relatively higher expression of CCKAR was observed in younger patients (age < 45 years) having more aggressive disease when compared with elderly ones (age ≥ 45 years). Conclusions. Age related differential expression of CCKAR in GBC may suggest two possible variants of the disease in this endemic belt.
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Zhou L, Yang H, Okoro EU, Guo Z. Up-regulation of cholesterol absorption is a mechanism for cholecystokinin-induced hypercholesterolemia. J Biol Chem 2014; 289:12989-99. [PMID: 24692543 DOI: 10.1074/jbc.m113.534388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Excessive absorption of intestinal cholesterol is a risk factor for atherosclerosis. This report examines the effect of cholecystokinin (CCK) on plasma cholesterol level and intestinal cholesterol absorption using the in vivo models of C57BL/6 wild-type and low density lipoprotein receptor knock-out (LDLR(-/-)) mice. These data were supported by in vitro studies involving mouse primary intestinal epithelial cells and human Caco-2 cells; both express CCK receptor 1 and 2 (CCK1R and CCK2R). We found that intravenous injection of [Thr(28),Nle(31)]CCK increased plasma cholesterol levels and intestinal cholesterol absorption in both wild-type and LDLR(-/-) mice. Treatment of mouse primary intestinal epithelial cells with [Thr(28),Nle(31)]CCK increased cholesterol absorption, whereas selective inhibition of CCK1R and CCK2R with antagonists attenuated CCK-induced cholesterol absorption. In Caco-2 cells, CCK enhanced CCK1R/CCK2R heterodimerization. Knockdown of both CCK1R and CCK2 or either one of them diminished CCK-induced cholesterol absorption to the same extent. CCK also increased cell surface-associated NPC1L1 (Niemann-Pick C1-like 1) transporters but did not alter their total protein expression. Inhibition or knockdown of NPC1L1 attenuated CCK-induced cholesterol absorption. CCK enhanced phosphatidylinositide 3-kinase (PI3K) and Akt phosphorylation and augmented the interaction between NPC1L1 and Rab11a (Rab-GTPase-11a), whereas knockdown of CCK receptors or inhibition of G protein βγ dimer (Gβγ) diminished CCK-induced PI3K and Akt phosphorylation. Inhibition of PI3K and Akt or knockdown of PI3K diminished CCK-induced NPC1L1-Rab11a interaction and cholesterol absorption. Knockdown of Rab11a suppressed CCK-induced NPC1L1 translocation and cholesterol absorption. These data imply that CCK enhances cholesterol absorption by activation of a pathway involving CCK1R/CCK2R, Gβγ, PI3K, Akt, Rab11a, and NPC1L.
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Affiliation(s)
- LiChun Zhou
- From the Department of Physiology, Meharry Medical College, Nashville, Tennessee 37208
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Myer JR, Romach EH, Elangbam CS. Species- and Dose-Specific Pancreatic Responses and Progression in Single- and Repeat-Dose Studies with GI181771X. Toxicol Pathol 2013; 42:260-74. [DOI: 10.1177/0192623313506792] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Compound-induced pancreatic injury is a serious liability in preclinical toxicity studies. However, its relevance to humans should be cautiously evaluated because of interspecies variations. To highlight such variations, we evaluated the species- and dose-specific pancreatic responses and progression caused by GI181771X, a novel cholecystokinin 1 receptor agonist investigated by GlaxoSmithKline for the treatment of obesity. Acute (up to 2,000 mg/kg GI181771X, as single dose) and repeat-dose studies in mice and/or rats (0.25–250 mg/kg/day for 7 days to 26 weeks) showed wide-ranging morphological changes in the pancreas that were dose and duration dependent, including necrotizing pancreatitis, acinar cell hypertrophy/atrophy, zymogen degranulation, focal acinar cell hyperplasia, and interstitial inflammation. In contrast to rodents, pancreatic changes were not observed in cynomolgus monkeys given GI181771X (1–500 mg/kg/day with higher systemic exposure than rats) for up to 52 weeks. Similarly, no GI181771X treatment-associated abnormalities in pancreatic structure were noted in a 24-week clinical trial with obese patients (body mass index >30 or >27 kg/m2) as assessed by abdominal ultrasound or by magnetic resonance imaging. Mechanisms for interspecies variations in the pancreatic response to CCK among rodents, monkeys, and humans and their relevance to human risk are discussed.
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Affiliation(s)
- James R. Myer
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Elizabeth H. Romach
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
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Alén F, Ramírez-López MT, Gómez de Heras R, Rodríguez de Fonseca F, Orio L. Cannabinoid Receptors and Cholecystokinin in Feeding Inhibition. ANOREXIA 2013; 92:165-96. [DOI: 10.1016/b978-0-12-410473-0.00007-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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15
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Barrett TD, Lagaud G, Wagaman P, Freedman JM, Yan W, Andries L, Rizzolio MC, Morton MF, Shankley NP. The cholecystokinin CCK2 receptor antagonist, JNJ-26070109, inhibits gastric acid secretion and prevents omeprazole-induced acid rebound in the rat. Br J Pharmacol 2012; 166:1684-93. [PMID: 22300007 DOI: 10.1111/j.1476-5381.2012.01878.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND AND PURPOSE JNJ-26070109 [(R)4-bromo-N-[1-(2,4-difluoro-phenyl)-ethyl]-2-(quinoxaline-5-sulfonylamino)-benzamide] is a novel antagonist at cholecystokinin CCK(2) receptors with good pharmacokinetic properties and represents a novel mechanism for the treatment of gastro-oesophageal reflux disease (GORD). The purpose of the present study was to determine whether chronic treatment with JNJ-26070109 could prevent, as well as treat, acid rebound in rats. EXPERIMENTAL APPROACH A chronic fistula was surgically inserted into the stomach of rats to enable the measurement of acid secretion under basal, pentagastrin and histamine-stimulated conditions. JNJ-26070109 and omeprazole were administered separately and in combination. KEY RESULTS Sustained administration of omeprazole alone and in combination with JNJ-26070109 inhibited gastric acid secretion by >90%. However, 3 days after withdrawing treatment, there was a rebound hypersecretion by ∼1.5-fold in omeprazole-treated animals. No such acid rebound was observed with JNJ-26070109 alone or with co-administration of JNJ-26070109 and omeprazole. The anti-trophic effects of JNJ-26070109 in the gastric mucosal paralleled the effects on acid rebound. Administration of JNJ-26070109 for 3 days after cessation of omeprazole prevented the occurrence of acid rebound. Interestingly, chronic, but not acute, treatment with JNJ-26070109 also inhibited histamine-stimulated acid secretion. CONCLUSIONS AND IMPLICATIONS Chronic administration of JNJ-26070109 effectively inhibited gastric acid secretion and suppressed proton pump inhibitor (PPI)-induced acid rebound in the rat. This work advances the field by demonstrating that modest doses of a competitive CCK(2) receptor antagonist have significant and functionally important anti-trophic actions in the gastric mucosa. These properties make JNJ-26070109 a suitable candidate for clinical investigation for the treatment of GORD.
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Affiliation(s)
- T D Barrett
- Cardiovascular Metabolic Research, Janssen Pharmaceutical Companies of Johnson & Johnson, San Diego, CA, USA.
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Rai R, Chandra V, Tewari M, Kumar M, Shukla HS. Cholecystokinin and gastrin receptors targeting in gastrointestinal cancer. Surg Oncol 2012; 21:281-92. [PMID: 22801592 DOI: 10.1016/j.suronc.2012.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 05/16/2012] [Accepted: 06/21/2012] [Indexed: 12/12/2022]
Abstract
Cholecystokinin and Gastrin are amongst the first gastrointestinal hormone discovered. In addition to classical actions (contraction of gallbladder, growth and secretion in the stomach and pancreas), these also act as growth stimulants for gastrointestinal malignancies and cell lines. Growth of these tumours is inhibited by antagonists of the cholecystokinin and gastrin receptors. These receptors provides most promising approach in clinical oncology and several specific radiolabelled ligands have been synthesized for specific tumour targeting and therapy of tumours overexpressing these receptors. Therefore, definition of the molecular structure of the receptor involved in the autocrine/paracrine loop may contribute to novel therapies for gastrointestinal cancer. Hence, this review tries to focus on the role and distribution of these hormones and their receptors in gastrointestinal cancer with a brief talk about the clinical trial using available agonist and antagonist in gastrointestinal cancers.
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Affiliation(s)
- Rajani Rai
- Department of Surgical Oncology, Banaras Hindu University, 7 SKG Colony, Lanka, Varanasi 221005, Uttar Pradesh, India
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Kinch DC, Peters JH, Simasko SM. Comparative pharmacology of cholecystokinin induced activation of cultured vagal afferent neurons from rats and mice. PLoS One 2012; 7:e34755. [PMID: 22514663 PMCID: PMC3326049 DOI: 10.1371/journal.pone.0034755] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 03/05/2012] [Indexed: 12/18/2022] Open
Abstract
Cholecystokinin (CCK) facilitates the process of satiation via activation of vagal afferent neurons innervating the upper gastrointestinal tract. Recent findings indicate CCK acts on these neurons via a ruthenium red (RuR) sensitive pathway that involves members of the vanilloid (V) subfamily of transient receptor potential (TRP) channels. To further test this mechanism, the mouse provides an ideal model in which genetic tools could be applied. However, whether CCK acts by similar mechanism(s) in mice has not been determined. In the present study we explored the actions of CCK on nodose neurons isolated from Sprague Dawley (SD) rat and two strains of mice; C57BL/6 and BalbC using fluorescence-based calcium imaging. With minor exceptions nodose neurons isolated from all species/strains behaved similarly. They all respond to brief depolarization with a large calcium transient. A significant subset of neurons responded to capsaicin (CAP), a TRPV1 agonist, although neurons from C57BL/6 were 10-fold more sensitive to CAP than SD rats or BalbC mice, and a significantly smaller fraction of neurons from BalbC mice responded to CAP. CCK-8 dose-dependently activated a subpopulation of neurons with similar dose dependency, percent responders, and overlap between CCK and CAP responsiveness. In all species/strains CCK-8 induced activation was significantly attenuated (but not completely blocked) by pretreatment with the TRPV channel blocker RuR. Surprisingly, the CCK analogue JMV-180, which is reported to have pure antagonistic properties in rat but mixed agonist/antagonist properties in mice, behaved as a pure antagonist to CCK in both rat and mouse neurons. The pure antagonistic action of JMV-180 in this in vitro preparation suggests that prior reported differential effects of JMV-180 on satiation in rats versus mouse must be mediated by a site other than vagal afferent activation.
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Affiliation(s)
- Dallas C. Kinch
- Program in Neuroscience, Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, Washington, United States of America
| | - James H. Peters
- Program in Neuroscience, Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, Washington, United States of America
| | - Steven M. Simasko
- Program in Neuroscience, Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, Washington, United States of America
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Cawston EE, Lam PCH, Harikumar KG, Dong M, Ball AM, Augustine ML, Akgün E, Portoghese PS, Orry A, Abagyan R, Sexton PM, Miller LJ. Molecular basis for binding and subtype selectivity of 1,4-benzodiazepine antagonist ligands of the cholecystokinin receptor. J Biol Chem 2012; 287:18618-35. [PMID: 22467877 DOI: 10.1074/jbc.m111.335646] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Allosteric binding pockets in peptide-binding G protein-coupled receptors create opportunities for the development of small molecule drugs with substantial benefits over orthosteric ligands. To gain insights into molecular determinants for this pocket within type 1 and 2 cholecystokinin receptors (CCK1R and CCK2R), we prepared a series of receptor constructs in which six distinct residues in TM2, -3, -6, and -7 were reversed. Two novel iodinated CCK1R- and CCK2R-selective 1,4-benzodiazepine antagonists, differing only in stereochemistry at C3, were used. When all six residues within CCK1R were mutated to corresponding CCK2R residues, benzodiazepine selectivity was reversed, yet peptide binding selectivity was unaffected. Detailed analysis, including observations of gain of function, demonstrated that residues 6.51, 6.52, and 7.39 were most important for binding the CCK1R-selective ligand, whereas residues 2.61 and 7.39 were most important for binding CCK2R-selective ligand, although the effect of substitution of residue 2.61 was likely indirect. Ligand-guided homology modeling was applied to wild type receptors and those reversing benzodiazepine binding selectivity. The models had high predictive power in enriching known receptor-selective ligands from related decoys, indicating a high degree of precision in pocket definition. The benzodiazepines docked in similar poses in both receptors, with C3 urea substituents pointing upward, whereas different stereochemistry at C3 directed the C5 phenyl rings and N1 methyl groups into opposite orientations. The geometry of the binding pockets and specific interactions predicted for ligand docking in these models provide a molecular framework for understanding ligand selectivity at these receptor subtypes. Furthermore, the strong predictive power of these models suggests their usefulness in the discovery of lead compounds and in drug development programs.
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Affiliation(s)
- Erin E Cawston
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259, USA
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Staljanssens D, De Vos WH, Willems P, Van Camp J, Smagghe G. Time-resolved quantitative analysis of CCK1 receptor-induced intracellular calcium increase. Peptides 2012; 34:219-25. [PMID: 21352882 DOI: 10.1016/j.peptides.2011.02.014] [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] [Received: 01/10/2011] [Revised: 02/11/2011] [Accepted: 02/15/2011] [Indexed: 01/18/2023]
Abstract
Cholecystokinin (CCK) is a gastrointestinal hormone, which regulates many physiological functions such as satiety by binding to the CCK receptor (CCKR). Molecules, which recognize this receptor can mimic or block CCK signaling and thereby influence CCKR-mediated processes. We have set up a quantitative heterologous assay with CHO cells over-expressing the rat CCK1 receptor to screen for such candidate molecules. Receptor activation, induced by agonist binding, is followed by an intracellular calcium increase, which was monitored using a fluorescent sensor dye. For quantification of the calcium increase, a population average technique using a fluorescence plate reader was optimized and subsequently compared with a single-cell approach using confocal microscopy. With both strategies, dose-response curves were generated for the natural agonist CCK-8S, the partial agonist JMV-180 as well as the antagonist lorglumide. Significant differences were found between the ligands and a strong correspondence was observed between both methods in terms of maximum response and median effect concentrations. Both highly sensitive methods proved complementary: whereas the plate reader assay allowed faster, high throughput screening, the confocal microscopy identified single-cell variations and revealed factors that reduce specificity and sensitivity.
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Abstract
The control of food intake consists of neural and hormonal signals between the gut and central nervous system (CNS). Gut hormones such as CCK, PYY and PP signal to important areas in the CNS involved in appetite regulation to terminate a meal. These hormones can act directly via the circulation and activate their respective receptors in the hypothalamus and brainstem. In addition, gut vagal afferents also exist, providing an alternative pathway through which gut hormones can communicate with higher centres through the brainstem. Animal and human studies have demonstrated that peripheral administration of certain gut hormones reduces food intake and leads to weight loss. Gut hormones are therefore potential targets in the development of novel treatments for obesity and analogue therapies are currently under investigation.
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Affiliation(s)
- K Simpson
- Department of Investigative Medicine, Imperial College London, UK
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Tjong Y, Ip S, Lao L, Fong HHS, Sung JJY, Berman B, Che C. Analgesic effect of Coptis chinensis rhizomes (Coptidis Rhizoma) extract on rat model of irritable bowel syndrome. JOURNAL OF ETHNOPHARMACOLOGY 2011; 135:754-61. [PMID: 21511022 PMCID: PMC3100428 DOI: 10.1016/j.jep.2011.04.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 03/23/2011] [Accepted: 04/05/2011] [Indexed: 05/24/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Coptis chinensis rhizomes (Coptidis Rhizoma, CR), also known as "Huang Lian", is a common component of traditional Chinese herbal formulae used for the relief of abdominal pain and diarrhea. Yet, the action mechanism of CR extract in the treatment of irritable bowel syndrome is unknown. Thus, the aim of our present study is to investigate the effect of CR extract on neonatal maternal separation (NMS)-induced visceral hyperalgesia in rats and its underlying action mechanisms. MATERIALS AND METHODS Male Sprague-Dawley rats were subjected to 3-h daily maternal separation from postnatal day 2 to day 21 to form the NMS group. The control group consists of unseparated normal (N) rats. From day 60, rats were administrated CR (0.3, 0.8 and 1.3 g/kg) or vehicle (Veh; 0.5% carboxymethylcellulose solution) orally for 7 days for the test and control groups, respectively. RESULTS Electromyogram (EMG) signals in response to colonic distension were measured with the NMS rats showing lower pain threshold and increased EMG activity than those of the unseparated (N) rats. CR dose-dependently increased pain threshold response and attenuated EMG activity in the NMS rats. An enzymatic immunoassay study showed that CR treatment significantly reduced the serotonin (5HT) concentration from the distal colon of NMS rats compared to the Veh (control) group. Real-time quantitative PCR and Western-blotting studies showed that CR treatment substantially reduced NMS induced cholecystokinin (CCK) expression compared with the Veh group. CONCLUSIONS These results suggest that CR extract robustly reduces visceral pain that may be mediated via the mechanism of decreasing 5HT release and CCK expression in the distal colon of rats.
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Affiliation(s)
- Yungwui Tjong
- School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
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Harikumar KG, Cawston EE, Miller LJ. Fluorescence polarization screening for allosteric small molecule ligands of the cholecystokinin receptor. Assay Drug Dev Technol 2011; 9:394-402. [PMID: 21395402 DOI: 10.1089/adt.2010.0310] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success in screening for drug candidates is highly dependent on the power of the strategy implemented. In this work, we report and characterize a novel fluorescent benzodiazepine antagonist of the type 1 cholecystokinin receptor (3-(3-(7-fluoro-1-(2-isopropyl(4-methoxyphenyl)amino)-2-oxoethyl)-2,4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-benzo[b][1,4]-diazepin-3-yl)ureido)benzoic acid) that can be used as a receptor ligand in a fluorescence polarization assay, which is ideally suited for the identification of small molecule allosteric modulators of this physiologically important receptor. By binding directly to the small molecule-docking region within the helical bundle of this receptor, this indicator can be displaced by many small molecule candidate drugs, even those that might not affect the binding of an orthosteric cholecystokinin-like peptide ligand. The biological, pharmacological, and fluorescence properties of this reagent are described, and proof-of-concept is provided in a fluorescence polarization assay utilizing this fluorescent benzodiazepine ligand.
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Affiliation(s)
- Kaleeckal G Harikumar
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, USA
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Staljanssens D, Azari EK, Christiaens O, Beaufays J, Lins L, Van Camp J, Smagghe G. The CCK(-like) receptor in the animal kingdom: functions, evolution and structures. Peptides 2011; 32:607-19. [PMID: 21167241 DOI: 10.1016/j.peptides.2010.11.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 11/27/2010] [Accepted: 11/30/2010] [Indexed: 01/09/2023]
Abstract
In this review, the cholecystokinin (CCK)(-like) receptors throughout the animal kingdom are compared on the level of physiological functions, evolutionary basis and molecular structure. In vertebrates, the CCK receptor is an important member of the G-protein coupled receptors as it is involved in the regulation of many physiological functions like satiety, gastrointestinal motility, gastric acid secretion, gall bladder contraction, pancreatic secretion, panic, anxiety and memory and learning processes. A homolog for this receptor is also found in nematodes and arthropods, called CK receptor and sulfakinin (SK) receptor, respectively. These receptors seem to have evolved from a common ancestor which is probably still closely related to the nematode CK receptor. The SK receptor is more closely related to the CCK receptor and seems to have similar functions. A molecular 3D-model for the CCK receptor type 1 has been built together with the docking of the natural ligands for the CCK and SK receptors in the CCK receptor type 1. These molecular models can help to study ligand-receptor interactions, that can in turn be useful in the development of new CCK(-like) receptor agonists and antagonists with beneficial health effects in humans or potential for pest control.
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Affiliation(s)
- Dorien Staljanssens
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2011; 18:83-98. [PMID: 21178692 DOI: 10.1097/med.0b013e3283432fa7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
PURPOSE OF REVIEW This review identifies and puts into context the recent articles which have advanced understanding of the functions of pancreatic acinar cells and the mechanisms by which these functions are regulated. RECENT FINDINGS Receptors present on acinar cells, particularly those for cholecystokinin and secretin, have been better characterized as to the molecular nature of the ligand-receptor interaction. Other reports have described the potential regulation of acinar cells by GLP-1 and cannabinoids. Intracellular Ca2+ signaling remains at the center of stimulus secretion coupling and its regulation has been further defined. Recent studies have identified specific channels mediating Ca2+ release from intracellular stores and influx across the plasma membrane. Work downstream of intracellular mediators has focused on molecular mechanisms of exocytosis particularly involving small G proteins, SNARE proteins and chaperone molecules. In addition to secretion, recent studies have further defined the regulation of pancreatic growth both in adaptive regulation to diet and hormones in the regeneration that occurs after pancreatic damage. Lineage tracing has been used to show the contribution of different cell types. The importance of specific amino acids as signaling molecules to activate the mTOR pathway is being elucidated. SUMMARY Understanding the mechanisms that regulate pancreatic acinar cell function is contributing to knowledge of normal pancreatic function and alterations in disease.
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Abstract
G protein-coupled receptors are the largest group of membrane proteins and are the targets for approximately 30% of drugs currently used therapeutically. These 7-transmembrane-spanning proteins continue to provide new opportunities to develop therapeutics based on emerging knowledge of their structure, signalling properties and interactions with other proteins. This themed issue of the British Journal of Pharmacology contains a series of papers that cover these issues and identify approaches that may determine future directions. Many of these papers contain material that was presented at the 5th International Molecular Pharmacology of G Protein-Coupled Receptors meeting held in Sydney Australia in late 2008.
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