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Babou Kammoe RB, Sévigny J. Extracellular nucleotides in smooth muscle contraction. Biochem Pharmacol 2024; 220:116005. [PMID: 38142836 DOI: 10.1016/j.bcp.2023.116005] [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: 08/24/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023]
Abstract
Extracellular nucleotides and nucleosides are crucial signalling molecules, eliciting diverse biological responses in almost all organs and tissues. These molecules exert their effects by activating specific nucleotide receptors, which are finely regulated by ectonucleotidases that break down their ligands. In this comprehensive review, we aim to elucidate the relevance of extracellular nucleotides as signalling molecules in the context of smooth muscle contraction, considering the modulatory influence of ectonucleotidases on this intricate process. Specifically, we provide a detailed examination of the involvement of extracellular nucleotides in the contraction of non-vascular smooth muscles, including those found in the urinary bladder, the airways, the reproductive system, and the gastrointestinal tract. Furthermore, we present a broader overview of the role of extracellular nucleotides in vascular smooth muscle contraction.
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Affiliation(s)
- Romuald Brice Babou Kammoe
- Centre de Recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada; Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Jean Sévigny
- Centre de Recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada; Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada.
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2
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Saffioti NA, Alvarez CL, Bazzi Z, Gentilini MV, Gondolesi GE, Schwarzbaum PJ, Schachter J. Dynamic recycling of extracellular ATP in human epithelial intestinal cells. PLoS Comput Biol 2023; 19:e1011196. [PMID: 37384797 DOI: 10.1371/journal.pcbi.1011196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/17/2023] [Indexed: 07/01/2023] Open
Abstract
Intestinal epithelial cells play important roles in the absorption of nutrients, secretion of electrolytes and food digestion. The function of these cells is strongly influenced by purinergic signalling activated by extracellular ATP (eATP) and other nucleotides. The activity of several ecto-enzymes determines the dynamic regulation of eATP. In pathological contexts, eATP may act as a danger signal controlling a variety of purinergic responses aimed at defending the organism from pathogens present in the intestinal lumen. In this study, we characterized the dynamics of eATP on polarised and non-polarised Caco-2 cells. eATP was quantified by luminometry using the luciferin-luciferase reaction. Results show that non-polarized Caco-2 cells triggered a strong but transient release of intracellular ATP after hypotonic stimuli, leading to low micromolar eATP accumulation. Subsequent eATP hydrolysis mainly determined eATP decay, though this effect could be counterbalanced by eATP synthesis by ecto-kinases kinetically characterized in this study. In polarized Caco-2 cells, eATP showed a faster turnover at the apical vs the basolateral side. To quantify the extent to which different processes contribute to eATP regulation, we created a data-driven mathematical model of the metabolism of extracellular nucleotides. Model simulations showed that eATP recycling by ecto-AK is more efficient a low micromolar eADP concentrations and is favored by the low eADPase activity of Caco-2 cells. Simulations also indicated that a transient eATP increase could be observed upon the addition of non-adenine nucleotides due the high ecto-NDPK activity in these cells. Model parameters showed that ecto-kinases are asymmetrically distributed upon polarization, with the apical side having activity levels generally greater in comparison with the basolateral side or the non-polarized cells. Finally, experiments using human intestinal epithelial cells confirmed the presence of functional ecto-kinases promoting eATP synthesis. The adaptive value of eATP regulation and purinergic signalling in the intestine is discussed.
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Affiliation(s)
- Nicolas Andres Saffioti
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Buenos Aires, Argentina
- Instituto de Nanosistemas, Universidad Nacional de General San Martin, Buenos Aires, Argentina
| | - Cora Lilia Alvarez
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
| | - Zaher Bazzi
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Buenos Aires, Argentina
| | - María Virginia Gentilini
- Fundación Favaloro Hospital Universitario, Unidad de Insuficiencia, Rehabilitación y Trasplante Intestinal, Buenos Aires, Argentina
- Instituto de Medicina Traslacional, Trasplante y Bioingeniería (IMETTyB, CONICET, Universidad Favaloro), Laboratorio de Inmunología asociada al Trasplante, Buenos Aires, Argentina
| | - Gabriel Eduardo Gondolesi
- Fundación Favaloro Hospital Universitario, Unidad de Insuficiencia, Rehabilitación y Trasplante Intestinal, Buenos Aires, Argentina
- Instituto de Medicina Traslacional, Trasplante y Bioingeniería (IMETTyB, CONICET, Universidad Favaloro), Laboratorio de Inmunología asociada al Trasplante, Buenos Aires, Argentina
| | - Pablo Julio Schwarzbaum
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Buenos Aires, Argentina
| | - Julieta Schachter
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica, Buenos Aires, Argentina
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Li Y, Zhang H, Yang J, Zhan M, Hu X, Liu Y, Yu L, Yan X, Liang S, Zhang R, Lu Y, Li B, Liu C, Li M. P2Y12 receptor as a new target for electroacupuncture relieving comorbidity of visceral pain and depression of inflammatory bowel disease. Chin Med 2021; 16:139. [PMID: 34930362 PMCID: PMC8686637 DOI: 10.1186/s13020-021-00553-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/10/2021] [Indexed: 12/16/2022] Open
Abstract
Background The P2Y12 receptor is a kind of purinoceptor that is engaged in platelet aggregation, and P2Y12 inhibitors have been used in clinical antithrombotic therapy. The P2Y12 receptor in microglia induces interleukin-1β (IL-1β) expression, which is a key mediator of depression in the brain. Although peripheral P2Y12 is involved in neuropathic pain, whether P2Y12 expression in the medial prefrontal cortex (mPFC) is associated with comorbidities of visceral pain and depression remains unclear. Accumulating evidence suggests that electroacupuncture (EA) is effective in treating inflammatory bowel disease (IBD), but its mechanism is unknown. This study aimed to determine whether P2Y12 expression in the mPFC is associated with comorbidities of visceral pain and depression in IBD and whether EA treats IBD by targeting the P2Y12 receptor. Methods We used 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced IBD mice. P2Y12 short hairpin RNA (shRNA) was stereotaxically injected into the bilateral mPFC. EA was performed on bilateral “Dachangshu” (BL25) acupoints once a day for 7 days. Von Frey filaments and colorectal distension were used to detect the mechanical pain threshold and visceral pain sensitivity. The sucrose preference test, tail suspension test and forced swimming test were used to evaluate depression in mice. Western blotting was used to test the expression of P2Y12 and IL-1β. Immunofluorescence staining was used to assess microglial activity. Results We found that IBD mice presented visceral pain and depression associated with increased P2Y12 expression in the mPFC. P2Y12 shRNA significantly attenuated visceral pain and depression in IBD mice. P2Y12 shRNA significantly downregulated IL-1β expression and inhibited the activation of microglia in the mPFC of IBD mice. Meanwhile, EA played a similar role of P2Y12 shRNA. EA significantly downregulated P2Y12 expression, weakened the activation of microglia, and then inhibited IL-1β expression in the mPFC, thus relieving visceral pain and depression in IBD mice. Conclusion The present study provided new ideas that the P2Y12 receptor in the mPFC could be a new target for the treatment of comorbid visceral pain and depression by EA. This may not only deepen our understanding of the analgesic and antidepressant mechanisms of EA but also promote the application of EA to treat IBD. Supplementary Information The online version contains supplementary material available at 10.1186/s13020-021-00553-9.
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Affiliation(s)
- Yanzhen Li
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Hong Zhang
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Jingwen Yang
- International Acupuncture and Moxibustion Innovation Institute, School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, 100029, China.
| | - Muouyang Zhan
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Xuefei Hu
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Yongmin Liu
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Lingling Yu
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaochen Yan
- Xiangya Hospital of Central South University, Changsha, 410000, China
| | - Shangdong Liang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, 330006, China
| | - Ruyue Zhang
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Ying Lu
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Beining Li
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Cunzhi Liu
- International Acupuncture and Moxibustion Innovation Institute, School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Man Li
- Department of Neurobiology, School of Basic Medicine, The Institute of Brain Research, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China.
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Dos Santos AGA, da Silva MGL, Carneiro EL, de Lima LL, Fernandes ACBS, Silveira TGV, Sant'Ana DDMG, Nogueira-Melo GDA. A New Target Organ of Leishmania (Viannia) braziliensis Chronic Infection: The Intestine. Front Cell Infect Microbiol 2021; 11:687499. [PMID: 34336715 PMCID: PMC8317265 DOI: 10.3389/fcimb.2021.687499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/22/2021] [Indexed: 01/22/2023] Open
Abstract
Leishmania (Viannia) braziliensis is one of the main causes of cutaneous leishmaniasis in the Americas. This species presents genetic polymorphism that can cause destructive lesions in oral, nasal, and oropharyngeal tracts. In a previous study, the parasite caused several histopathological changes to hamster ileums. Our study evaluates immune response components, morphological changes, and effects on neurons in the ileums of hamsters infected by three different strains of L. (V.) braziliensis in two infection periods. For the experiment, we separated hamsters into four groups: a control group and three infected groups. Infected hamsters were euthanized 90- or 120-days post infection. We used three strains of L. (V.) braziliensis: the reference MHOM/BR/1975/M2903 and two strains isolated from patients who had different responses to Glucantime® treatment (MHOM/BR/2003/2314 and MHOM/BR/2000/1655). After laparotomy, ileums were collected for histological processing, biochemical analysis, and evaluation of neurons in the myenteric and submucosal plexuses of the enteric nervous system (ENS). The results demonstrated the increase of blood leukocytes after the infection. Optical microscopy analysis showed histopathological changes with inflammatory infiltrates, edemas, ganglionitis, and Leishmania amastigotes in the ileums of infected hamsters. We observed changes in the organ histoarchitecture of infected hamsters when compared to control groups, such as thicker muscular and submucosa layers, deeper and wider crypts, and taller and broader villi. The number of intraepithelial lymphocytes and TGF-β-immunoreactive cells increased in all infected groups when compared to the control groups. Mast cells increased with longer infection periods. The infection also caused remodeling of intestinal collagen and morphometry of myenteric and submucosal plexus neurons; but this effect was dependent on infection duration. Our results show that L. (V.) braziliensis infection caused time-dependent alterations in hamster ileums. This was demonstrated by the reduction of inflammatory cells and the increase of tissue regeneration factors at 120 days of infection. The infected groups demonstrated different profiles in organ histoarchitecture, migration of immune cells, and morphometry of ENS neurons. These findings suggest that the small intestine (or at least the ileum) is a target organ for L. (V.) braziliensis infection, as the infection caused changes that were dependent on duration and strain.
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Affiliation(s)
| | | | - Erick Lincoln Carneiro
- Department of Clinical Analysis and Biomedicine, Universidade Estadual de Maringá, Maringá, Brazil
| | - Lainy Leiny de Lima
- Department of Morphological Sciences, Universidade Estadual de Maringá, Maringá, Brazil
| | | | | | - Debora de Mello Gonçales Sant'Ana
- Biosciences and Physiopathology Program, Universidade Estadual de Maringá, Maringá, Brazil.,Department of Morphological Sciences, Universidade Estadual de Maringá, Maringá, Brazil
| | - Gessilda de Alcantara Nogueira-Melo
- Biosciences and Physiopathology Program, Universidade Estadual de Maringá, Maringá, Brazil.,Department of Clinical Analysis and Biomedicine, Universidade Estadual de Maringá, Maringá, Brazil
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Schneider R, Leven P, Glowka T, Kuzmanov I, Lysson M, Schneiker B, Miesen A, Baqi Y, Spanier C, Grants I, Mazzotta E, Villalobos‐Hernandez E, Kalff JC, Müller CE, Christofi FL, Wehner S. A novel P2X2-dependent purinergic mechanism of enteric gliosis in intestinal inflammation. EMBO Mol Med 2021; 13:e12724. [PMID: 33332729 PMCID: PMC7799361 DOI: 10.15252/emmm.202012724] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/19/2022] Open
Abstract
Enteric glial cells (EGC) modulate motility, maintain gut homeostasis, and contribute to neuroinflammation in intestinal diseases and motility disorders. Damage induces a reactive glial phenotype known as "gliosis", but the molecular identity of the inducing mechanism and triggers of "enteric gliosis" are poorly understood. We tested the hypothesis that surgical trauma during intestinal surgery triggers ATP release that drives enteric gliosis and inflammation leading to impaired motility in postoperative ileus (POI). ATP activation of a p38-dependent MAPK pathway triggers cytokine release and a gliosis phenotype in murine (and human) EGCs. Receptor antagonism and genetic depletion studies revealed P2X2 as the relevant ATP receptor and pharmacological screenings identified ambroxol as a novel P2X2 antagonist. Ambroxol prevented ATP-induced enteric gliosis, inflammation, and protected against dysmotility, while abrogating enteric gliosis in human intestine exposed to surgical trauma. We identified a novel pathogenic P2X2-dependent pathway of ATP-induced enteric gliosis, inflammation and dysmotility in humans and mice. Interventions that block enteric glial P2X2 receptors during trauma may represent a novel therapy in treating POI and immune-driven intestinal motility disorders.
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Affiliation(s)
| | | | - Tim Glowka
- Department of SurgeryUniversity of BonnBonnGermany
| | | | | | | | - Anna Miesen
- Department of SurgeryUniversity of BonnBonnGermany
| | - Younis Baqi
- Faculty of ScienceDepartment of ChemistrySultan Qaboos UniversityMuscatOman
- Pharmaceutical InstitutePharmaceutical & Medical ChemistryUniversity of BonnBonnGermany
| | - Claudia Spanier
- Pharmaceutical InstitutePharmaceutical & Medical ChemistryUniversity of BonnBonnGermany
| | - Iveta Grants
- Department of AnesthesiologyWexner Medical CenterThe Ohio State UniversityColumbusOHUSA
| | - Elvio Mazzotta
- Department of AnesthesiologyWexner Medical CenterThe Ohio State UniversityColumbusOHUSA
| | | | - Jörg C Kalff
- Department of SurgeryUniversity of BonnBonnGermany
| | - Christa E Müller
- Pharmaceutical InstitutePharmaceutical & Medical ChemistryUniversity of BonnBonnGermany
| | - Fedias L Christofi
- Department of AnesthesiologyWexner Medical CenterThe Ohio State UniversityColumbusOHUSA
| | - Sven Wehner
- Department of SurgeryUniversity of BonnBonnGermany
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6
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Tocchetti GN, Domínguez CJ, Zecchinati F, Arana MR, Rigalli JP, Ruiz ML, Villanueva SSM, Mottino AD. Intraluminal nutrients acutely strengthen rat intestinal MRP2 barrier function by a glucagon-like peptide-2-mediated mechanism. Acta Physiol (Oxf) 2020; 230:e13514. [PMID: 32476256 DOI: 10.1111/apha.13514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/22/2020] [Accepted: 05/24/2020] [Indexed: 01/02/2023]
Abstract
AIM MRP2 is an intestinal ABC transporter that prevents the absorption of dietary xenobiotics. The aims of this work were: (1) to evaluate whether a short-term regulation of intestinal MRP2 barrier function takes place in vivo after luminal incorporation of nutrients and (2) to explore the underlying mechanism. METHODS MRP2 activity and localization were assessed in an in vivo rat model with preserved irrigation and innervation. Nutrients were administered into distal jejunum. After 30-minutes treatments, MRP2 activity was assessed in proximal jejunum by quantifying the transport of the model substrate 2,4-dinitrophenyl-S-glutathione. MRP2 localization was determined by quantitative confocal microscopy. Participation of extracellular mediators was evaluated using selective inhibitors and by immunoneutralization. Intracellular pathways were explored in differentiated Caco-2 cells. RESULTS Oleic acid, administered intraluminally at dietary levels, acutely stimulated MRP2 insertion into brush border membrane. This was associated with increased efflux activity and, consequently, enhanced barrier function. Immunoneutralization of the gut hormone glucagon-like peptide-2 (GLP-2) prevented oleic acid effect on MRP2, demonstrating the participation of this trophic factor as a main mediator. Further experiments using selective inhibitors demonstrated that extracellular adenosine synthesis and its subsequent binding to enterocytic A2B adenosine receptor (A2BAR) take place downstream GLP-2. Finally, studies in intestinal Caco-2 cells revealed the participation of A2BAR/cAMP/PKA intracellular pathway, ultimately leading to increased MRP2 localization in apical domains. CONCLUSION These findings reveal an on-demand, acute regulation of MRP2-associated barrier function, constituting a novel physiological mechanism of protection against the absorption of dietary xenobiotics in response to food intake.
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Affiliation(s)
- Guillermo N. Tocchetti
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
- Department of Clinical Pharmacology and Pharmacoepidemiology University of Heidelberg Heidelberg Germany
| | - Camila J. Domínguez
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
| | - Felipe Zecchinati
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
| | - Maite R. Arana
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
| | - Juan P. Rigalli
- Department of Clinical Pharmacology and Pharmacoepidemiology University of Heidelberg Heidelberg Germany
| | - María L. Ruiz
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
| | - Silvina S. M. Villanueva
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
| | - Aldo D. Mottino
- Institute of Experimental Physiology (IFISE) National Scientific and Technical Research Council (CONICET)National University of Rosario (UNR) Rosario Argentina
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Antonioli L, Fornai M, Pellegrini C, Bertani L, Nemeth ZH, Blandizzi C. Inflammatory Bowel Diseases: It's Time for the Adenosine System. Front Immunol 2020; 11:1310. [PMID: 32849492 PMCID: PMC7403190 DOI: 10.3389/fimmu.2020.01310] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/22/2020] [Indexed: 12/16/2022] Open
Affiliation(s)
- Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Matteo Fornai
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Lorenzo Bertani
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Zoltan H Nemeth
- Department of Surgery, Morristown Medical Center, Morristown, NJ, United States.,Department of Anesthesiology, Columbia University Medical Center, New York, NY, United States
| | - Corrado Blandizzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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8
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Dal Ben D, Antonioli L, Lambertucci C, Spinaci A, Fornai M, D'Antongiovanni V, Pellegrini C, Blandizzi C, Volpini R. Approaches for designing and discovering purinergic drugs for gastrointestinal diseases. Expert Opin Drug Discov 2020; 15:687-703. [PMID: 32228110 DOI: 10.1080/17460441.2020.1743673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Purines finely modulate physiological motor, secretory, and sensory functions in the gastrointestinal tract. Their activity is mediated by the purinergic signaling machinery, including receptors and enzymes regulating their synthesis, release, and degradation. Several gastrointestinal dysfunctions are characterized by alterations affecting the purinergic system. AREAS COVERED The authors provide an overview on the purinergic receptor signaling machinery, the molecules and proteins involved, and a summary of medicinal chemistry efforts aimed at developing novel compounds able to modulate the activity of each player involved in this machinery. The involvement of purinergic signaling in gastrointestinal motor, secretory, and sensory functions and dysfunctions, and the potential therapeutic applications of purinergic signaling modulators, are then described. EXPERT OPINION A number of preclinical and clinical studies demonstrate that the pharmacological manipulation of purinergic signaling represents a viable way to counteract several gastrointestinal diseases. At present, the paucity of purinergic therapies is related to the lack of receptor-subtype-specific agonists and antagonists that are effective in vivo. In this regard, the development of novel therapeutic strategies should be focused to include tools able to control the P1 and P2 receptor expression as well as modulators of the breakdown or transport of purines.
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Affiliation(s)
- Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Luca Antonioli
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Catia Lambertucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Andrea Spinaci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Matteo Fornai
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Vanessa D'Antongiovanni
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | | | - Corrado Blandizzi
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Rosaria Volpini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
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Guerra DD, Bok R, Lorca RA, Hurt KJ. Protein kinase A facilitates relaxation of mouse ileum via phosphorylation of neuronal nitric oxide synthase. Br J Pharmacol 2020; 177:2765-2778. [PMID: 31975425 DOI: 10.1111/bph.15001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/03/2020] [Accepted: 01/18/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE The enteric neurotransmitter nitric oxide (NO) regulates gastrointestinal motility by relaxing smooth muscle. Pharmacological cAMP induction also relaxes gastrointestinal smooth muscle, but it is uncertain whether cAMP augments or suppresses enteric NO signalling. In other organ systems, cAMP can increase neuronal NO production by stimulating protein kinase A (PKA) to phosphorylate neuronal NOS (nNOS) Serine-1412 (S1412). We hypothesized that cAMP also increases nNOS S1412 phosphorylation by PKA in enteric neurons to augment nitrergic relaxation of mouse ileum. EXPERIMENTAL APPROACH We measured contractile force and nNOS S1412 phosphorylation in ileal rings suspended in an organ bath. We used forskolin to induce cAMP-dependent relaxation of wild type, nNOSS1412A knock-in and nNOSα-null ileal rings in the presence or absence of PKA, protein kinase B (Akt) and NOS inhibitors. KEY RESULTS Forskolin stimulated phosphorylation of nNOS S1412 in mouse ileum. Forskolin relaxed nNOSα-null and nNOSS1412A ileal rings less than wild-type ileal rings. PKA inhibition blocked forskolin-induced nNOS phosphorylation and attenuated relaxation of wild type but not nNOSS1412A ileum. Akt inhibition did not alter nNOS phosphorylation with forskolin but did attenuate relaxation of wild type and nNOSS1412A . NOS inhibition with L-NAME eliminated the effects of PKA and Akt inhibitors on relaxation. CONCLUSION AND IMPLICATIONS PKA phosphorylation of nNOS S1412 augments forskolin-induced nitrergic ileal relaxation. The relationship between cAMP/PKA and NO is therefore synergistic in enteric nitrergic neurons. Because NO regulates gut motility, selective modulation of enteric neuronal cAMP synthesis may be useful for the treatment of gastrointestinal motility disorders.
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Affiliation(s)
- Damian D Guerra
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Rachael Bok
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Ramón A Lorca
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - K Joseph Hurt
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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10
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Grubišić V, Perez-Medina AL, Fried DE, Sévigny J, Robson SC, Galligan JJ, Gulbransen BD. NTPDase1 and -2 are expressed by distinct cellular compartments in the mouse colon and differentially impact colonic physiology and function after DSS colitis. Am J Physiol Gastrointest Liver Physiol 2019; 317:G314-G332. [PMID: 31188623 PMCID: PMC6774087 DOI: 10.1152/ajpgi.00104.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
ATP is both an important mediator of physiological gut functions such as motility and epithelial function, and a key danger signal that mediates cell death and tissue damage. The actions of extracellular ATP are regulated through the catalytic functions extracellular nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), -2, -3, and -8, which ultimately generate nucleosides. Ectonucleotidases have distinct cellular associations, but the specific locations and functional roles of individual NTPDases in the intestine are still poorly understood. Here, we tested the hypothesis that differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in gut physiology and disease. We studied Entpd1 and Entpd2 null mice in health and following colitis driven by 2% dextran sulfate sodium (DSS) administration using functional readouts of gut motility, epithelial barrier function, and neuromuscular communication. NTPDase1 is expressed by immune cells, and the ablation of Entpd1 altered glial numbers in the myenteric plexus. NTPDase2 is expressed by enteric glia, and the ablation of Entpd2 altered myenteric neuron numbers. Mice lacking either NTPDase1 or -2 exhibited decreased inhibitory neuromuscular transmission and altered components of inhibitory junction potentials. Ablation of Entpd2 increased gut permeability following inflammation. In conclusion, the location- and context-dependent extracellular nucleotide phosphohydrolysis by NTPDase1 and -2 substantially impacts gut function in health and disease.NEW & NOTEWORTHY Purines are important mediators of gastrointestinal physiology and pathophysiology. Nucleoside triphosphate diphosphohydrolases (NTPDases) regulate extracellular purines, but the roles of specific NTPDases in gut functions are poorly understood. Here, we used Entpd1- and Entpd2-deficient mice to show that the differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in barrier function, gut motility, and neuromuscular communication in health and disease.
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Affiliation(s)
- Vladimir Grubišić
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Alberto L. Perez-Medina
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - David E. Fried
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Jean Sévigny
- 3Centre de recherche du CHU de Québec–Université Laval, Québec City, Quebec, Canada,4Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Quebec, Canada
| | - Simon C. Robson
- 5Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - James J. Galligan
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
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11
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Buccioni M, Dal Ben D, Lambertucci C, Martí Navia A, Ricciutelli M, Spinaci A, Volpini R, Marucci G. New sensible method to quantize the intestinal absorption of receptor ligands. Bioorg Med Chem 2019; 27:3328-3333. [PMID: 31230970 DOI: 10.1016/j.bmc.2019.06.011] [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] [Received: 04/19/2019] [Revised: 05/31/2019] [Accepted: 06/05/2019] [Indexed: 02/08/2023]
Abstract
In recent years, special attention has been paid to the A3 adenosine receptor (A3AR) as a possible pharmacological target to treat intestinal inflammation. In this work, it was set up a novel method to quantify the concentration of a promising anti-inflammatory agent inside and outside of intestinal barrier using the everted gut sac technique. The compound chosen for the present study is one of the most potent and selective A3AR agonist reported so far, named AR 170 (N6-methyl-2-phenylethynyl-5'-N-methylcarboxamidoadenosine). In order to evaluate the intestinal absorption of AR 170 the radioligand binding assay in comparison with HPLC-DAD was used. Results showed that the compound is absorbed via passive diffusion by paracellular pathway. The concentrations determined in the serosal (inside the sac) fluid by radioligand binding assay are in good agreement with those obtained through the widely used HPLC/MS protocol, demonstrating the reliability of the method. It is worthwhile to note that the radioligand binding assay allows detecting very low concentrations of analyte, thus offering an excellent tool to measure the intestinal absorption of receptor ligands. Moreover, the AR 170 quantity outside the gut sac and the interaction with A3AR could presuppose good topical anti-inflammatory effects of this compound.
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Affiliation(s)
- Michela Buccioni
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Diego Dal Ben
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Catia Lambertucci
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Aleix Martí Navia
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Massimo Ricciutelli
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Andrea Spinaci
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Rosaria Volpini
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy
| | - Gabriella Marucci
- School of Medicinal Sciences and Health Products, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032 Camerino, Italy.
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12
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Park IK, Kim JH, Park CG, Kim MY, Parajuli SP, Hong CS, Choi S, Jun JY. Effects of ATP on Pacemaker Activity of Interstitial Cells of Cajal from the Mouse Small Intestine. Chonnam Med J 2018; 54:63-71. [PMID: 29399568 PMCID: PMC5794481 DOI: 10.4068/cmj.2018.54.1.63] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 01/23/2023] Open
Abstract
Purinergic receptors play an important role in regulating gastrointestinal (GI) motility. Interstitial cells of Cajal (ICCs) are pacemaker cells that regulate GI smooth muscle activity. We studied the functional roles of external adenosine 5′-triphosphate (ATP) on pacemaker activity in cultured ICCs from mouse small intestines by using the whole-cell patch clamp technique and intracellular Ca2+ ([Ca2+]i) imaging. External ATP dose-dependently depolarized the resting membrane and produced tonic inward pacemaker currents, and these effects were antagonized by suramin, a purinergic P2 receptor antagonist. ATP-induced effects on pacemaker currents were suppressed by an external Na+-free solution and inhibited by the nonselective cation channel blockers, flufenamic acid and niflumic acid. The removal of external Ca2+ or treatment with thapsigargin (inhibitor of Ca2+ uptake into endoplasmic reticulum) inhibited the ATP-induced effects on pacemaker currents. Spontaneous [Ca2+]i oscillations were enhanced by external ATP. These results suggest that external ATP modulates pacemaker activity by activating nonselective cation channels via external Ca2+ influx and [Ca2+]i release from the endoplasmic reticulum. Thus, it seems that activating the purinergic P2 receptor may modulate GI motility by acting on ICCs in the small intestine.
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Affiliation(s)
- Il Koo Park
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Jin Ho Kim
- Department of Neurology, College of Medicine, Chosun University, Gwangju, Korea
| | - Chan Guk Park
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Man Yoo Kim
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | | | - Chan Sik Hong
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Jae Yeoul Jun
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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13
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Asano T, Takenaga M. Adenosine A 2B Receptors: An Optional Target for the Management of Irritable Bowel Syndrome with Diarrhea? J Clin Med 2017; 6:jcm6110104. [PMID: 29099770 PMCID: PMC5704121 DOI: 10.3390/jcm6110104] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 12/12/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder, with the characteristic symptoms of chronic abdominal pain and altered bowel habits (diarrhea, constipation, or both). IBS is a highly prevalent condition, which negatively affects quality of life and is a significant burden on global healthcare costs. Although many pharmacological medicines have been proposed to treat IBS, including those targeting receptors, channels, and chemical mediators related to visceral hypersensitivity, successful pharmacotherapy for the disease has not been established. Visceral hypersensitivity plays an important role in IBS pathogenesis. Immune activation is observed in diarrhea-predominant patients with IBS and contributes to the development of visceral hypersensitivity. Adenosine is a chemical mediator that regulates many physiological processes, including inflammation and nociception. Among its receptors, the adenosine A2B receptor regulates intestinal secretion, motor function, and the immune response. We recently demonstrated that the adenosine A2B receptor is involved in visceral hypersensitivity in animal models of IBS. In this review, we discuss the possibility of the adenosine A2B receptor as a novel therapeutic target for IBS.
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Affiliation(s)
- Teita Asano
- Institute of Medical Science, St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki 216-8512, Japan.
| | - Mitsuko Takenaga
- Institute of Medical Science, St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki 216-8512, Japan.
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14
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Escalante J, McQuade RM, Stojanovska V, Nurgali K. Impact of chemotherapy on gastrointestinal functions and the enteric nervous system. Maturitas 2017; 105:23-29. [DOI: 10.1016/j.maturitas.2017.04.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 04/25/2017] [Indexed: 02/07/2023]
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15
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Soghomonyan S, Abdel-Rasoul M, Zuleta-Alarcon A, Grants I, Davila V, Yu J, Zhang C, Whitaker EE, Bergese SD, Stoicea N, Arsenescu R, Christofi FL. Clopidogrel IBS Patients Have Higher Incidence of Gastrointestinal Symptoms Influenced by Age and Gender. Dig Dis Sci 2017; 62:2728-2743. [PMID: 28840395 PMCID: PMC6075816 DOI: 10.1007/s10620-017-4707-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/31/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Clopidogrel is an irreversible antagonist of P2Y12 receptors (P2Y12Rs) used as an antiplatelet drug to reduce risk of thrombosis. P2Y12Rs are expressed in gastrointestinal (GI) tract where they might regulate GI function. AIM To evaluate if blockade of P2Y12Rs by clopidogrel is associated with higher incidence of GI symptoms in patients with irritable bowel syndrome (IBS). METHODS A retrospective analysis of our institutional database was conducted for a 13-year period. IBS patients were identified, and their demographics, GI symptoms and clopidogrel therapy were collected. Logistic regression models were used to characterize symptoms in clopidogrel versus no-clopidogrel IBS-groups, adjusting for Age and Sex differences. An additional study characterized the P2Y12R distribution in human gut. RESULTS The search identified 7217 IBS patients (6761 no-clopidogrel/456 clopidogrel). There were a higher proportion of patients with GI symptoms on clopidogrel (68%) compared to controls (60%, p = 0.0011) that were Females (70 vs. 60%, p = 0.0003) not Males (61 vs. 60%; p = 0.8312). In Females, clopidogrel was associated with higher incidence of GI symptoms (Age adjusted; p < 0.0001) for pain, constipation, gastroparesis (p ≤ 0.0001) and psychogenic pain (p = 0.0006). Age or Sex (adjusted models) influenced one or more GI symptoms (i.e., pain, p < 0.0001; constipation, p < 0.0001/p = 0.008; diarrhea, flatulence, p = 0.01). P2Y12R immunoreactivity was abundant in human ENS; glial-to-neuron ratio of P2Y12Rs expressed in Females ≫ Males. CONCLUSIONS Irreversible blockade of P2Y12R by clopidogrel is associated with higher incidence of GI symptoms in Female IBS patients, although Age or Sex alone contributes to symptomatology. Prospective studies can determine clinical implications of P2Y12Rs in IBS.
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Affiliation(s)
- Suren Soghomonyan
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Mahmoud Abdel-Rasoul
- Department of Biomedical Informatics, Center for Biostatistics, The Ohio State University, 1800 Cannon Drive, Room 320, Columbus, OH 43210, USA
| | - Alix Zuleta-Alarcon
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Iveta Grants
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Victor Davila
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Jeffrey Yu
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Cheng Zhang
- Department of Internal Medicine, Wexner Medical Center, The Ohio State University, 395 West 12th Ave, Suite 200, Columbus, OH 43210, USA
| | - Emmett E. Whitaker
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA,Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43205, USA
| | - Sergio D. Bergese
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Nicoleta Stoicea
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
| | - Razvan Arsenescu
- Department of Internal Medicine, Wexner Medical Center, The Ohio State University, 395 West 12th Ave, Suite 200, Columbus, OH 43210, USA,Atlantic Inflammatory Bowel Disease Center of Excellence, Atlantic Digestive Health Institute, 435 South Street, Suite 205, Morristown, NJ 07960, USA
| | - Fievos L. Christofi
- Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH 43210, USA
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16
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Arin RM, Gorostidi A, Navarro-Imaz H, Rueda Y, Fresnedo O, Ochoa B. Adenosine: Direct and Indirect Actions on Gastric Acid Secretion. Front Physiol 2017; 8:737. [PMID: 29018360 PMCID: PMC5614973 DOI: 10.3389/fphys.2017.00737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/11/2017] [Indexed: 12/12/2022] Open
Abstract
Composed by a molecule of adenine and a molecule of ribose, adenosine is a paradigm of recyclable nucleoside with a multiplicity of functions that occupies a privileged position in the metabolic and regulatory contexts. Adenosine is formed continuously in intracellular and extracellular locations of all tissues. Extracellular adenosine is a signaling molecule, able to modulate a vast range of physiologic responses in many cells and organs, including digestive organs. The adenosine A1, A2A, A2B, and A3 receptors are P1 purinergic receptors, G protein-coupled proteins implicated in tissue protection. This review is focused on gastric acid secretion, a process centered on the parietal cell of the stomach, which contains large amounts of H+/K+-ATPase, the proton pump responsible for proton extrusion during acid secretion. Gastric acid secretion is regulated by an extensive collection of neural stimuli and endocrine and paracrine agents, which act either directly at membrane receptors of the parietal cell or indirectly through other regulatory cells of the gastric mucosa, as well as mechanic and chemic stimuli. In this review, after briefly introducing these points, we condense the current body of knowledge about the modulating action of adenosine on the pathophysiology of gastric acid secretion and update its significance based on recent findings in gastric mucosa and parietal cells in humans and animal models.
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Affiliation(s)
- Rosa M Arin
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
| | - Adriana Gorostidi
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
| | - Hiart Navarro-Imaz
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
| | - Yuri Rueda
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
| | - Olatz Fresnedo
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
| | - Begoña Ochoa
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU)Leioa, Spain
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17
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Liñán-Rico A, Ochoa-Cortes F, Zuleta-Alarcon A, Alhaj M, Tili E, Enneking J, Harzman A, Grants I, Bergese S, Christofi FL. UTP - Gated Signaling Pathways of 5-HT Release from BON Cells as a Model of Human Enterochromaffin Cells. Front Pharmacol 2017; 8:429. [PMID: 28751862 PMCID: PMC5508028 DOI: 10.3389/fphar.2017.00429] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/15/2017] [Indexed: 12/30/2022] Open
Abstract
Background: Enterochromaffin cells (EC) synthesize and release 5-HT and ATP to trigger or modulate gut neural reflexes and transmit information about visceral/pain sensation. Alterations in 5-HT signaling mechanisms may contribute to the pathogenesis of IBD or IBS, but the pharmacologic or molecular mechanisms modulating Ca2+-dependent 5-HT release are not understood. Previous studies indicated that purinergic signaling via ATP and ADP is an important mechanism in modulation of 5-HT release. However, EC cells also respond to UTP and UDP suggesting uridine triphosphate receptor and signaling pathways are involved as well. We tested the hypothesis that UTP is a regulator of 5-HT release in human EC cells. Methods: UTP signaling mechanisms were studied in BON cells, a human EC model, using Fluo-4/Ca2+imaging, patch-clamp, pharmacological analysis, immunohistochemistry, western blots and qPCR. 5-HT release was monitored in BON or EC isolated from human gut surgical specimens (hEC). Results: UTP, UTPγS, UDP or ATP induced Ca2+oscillations in BON. UTP evoked a biphasic concentration-dependent Ca2+response. Cells responded in the order of UTP, ATP > UTPγS > UDP >> MRS2768, BzATP, α,β-MeATP > MRS2365, MRS2690, and NF546. Different proportions of cells activated by UTP and ATP also responded to UTPγS (P2Y4, 50% cells), UDP (P2Y6, 30%), UTPγS and UDP (14%) or MRS2768 (<3%). UTP Ca2+responses were blocked with inhibitors of PLC, IP3R, SERCA Ca2+pump, La3+sensitive Ca2+channels or chelation of intracellular free Ca2+ by BAPTA/AM. Inhibitors of L-type, TRPC, ryanodine-Ca2+pools, PI3-Kinase, PKC or SRC-Kinase had no effect. UTP stimulated voltage-sensitive Ca2+currents (ICa), Vm-depolarization and inhibited IK (not IA) currents. An IKv7.2/7.3 K+ channel blocker XE-991 mimicked UTP-induced Vm-depolarization and blocked UTP-responses. XE-991 blocked IK and UTP caused further reduction. La3+ or PLC inhibitors blocked UTP depolarization; PKC inhibitors, thapsigargin or zero Ca2+buffer did not. UTP stimulated 5-HT release in hEC expressing TPH1, 5-HT, P2Y4/P2Y6R. Zero-Ca2+buffer augmented Ca2+responses and 5-HT release. Conclusion: UTP activates a predominant P2Y4R pathway to trigger Ca2+oscillations via internal Ca2+mobilization through a PLC/IP3/IP3R/SERCA Ca2+signaling pathway to stimulate 5-HT release; Ca2+influx is inhibitory. UTP-induced Vm-depolarization depends on PLC signaling and an unidentified K channel (which appears independent of Ca2+oscillations or Ica/VOCC). UTP-gated signaling pathways triggered by activation of P2Y4R stimulate 5-HT release.
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Affiliation(s)
- Andromeda Liñán-Rico
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Fernando Ochoa-Cortes
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Alix Zuleta-Alarcon
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Mazin Alhaj
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Esmerina Tili
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
- Molecular Virology, Immunology and Medical Genetics, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Josh Enneking
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Alan Harzman
- Department of Surgery, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Iveta Grants
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Sergio Bergese
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
| | - Fievos L. Christofi
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States
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18
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Purinergic Signalling in the Gut. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 891:91-112. [PMID: 27379638 DOI: 10.1007/978-3-319-27592-5_10] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The article will begin with the discovery of purinergic inhibitory neuromuscular transmission in the 1960s/1970s, the proposal for purinergic cotransmission in 1976 and the recognition that sympathetic nerves release adenosine 5'-triphosphate (ATP), noradrenaline and neuropeptide Y, while non-adrenergic, non-cholinergic inhibitory nerve cotransmitters are ATP, nitric oxide and vasoactive intestinal polypeptide in variable proportions in different regions of the gut. Later, purinergic synaptic transmission in the myenteric and submucosal plexuses was established and purinergic receptors expressed by both glial and interstitial cells. The focus will then be on purinergic mechanosensory transduction involving release of ATP from mucosal epithelial cells during distension to activate P2X3 receptors on submucosal sensory nerve endings. The responses of low threshold fibres mediate enteric reflex activity via intrinsic sensory nerves, while high threshold fibres initiate pain via extrinsic sensory nerves. Finally, the involvement of purinergic signalling in an animal model of colitis will be presented, showing that during distension there is increased ATP release, increased P2X3 receptor expression on calcitonin gene-related peptide-labelled sensory neurons and increased sensory nerve activity.
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19
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da Silva MV, Marosti AR, Mendes CE, Palombit K, Castelucci P. Submucosal neurons and enteric glial cells expressing the P2X7 receptor in rat experimental colitis. Acta Histochem 2017; 119:481-494. [PMID: 28501138 DOI: 10.1016/j.acthis.2017.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/04/2017] [Accepted: 05/02/2017] [Indexed: 02/06/2023]
Abstract
The aim of this study was to evaluate the effect of ulcerative colitis on the submucosal neurons and glial cells of the submucosal ganglia of rats. 2,4,6-Trinitrobenzene sulfonic acid (TNBS; colitis group) was administered in the colon to induce ulcerative colitis, and distal colons were collected after 24h. The colitis rats were compared with those in the sham and control groups. Double labelling of the P2X7 receptor with calbindin (marker for intrinsic primary afferent neurons, IPANs, submucosal plexus), calretinin (marker for secretory and vasodilator neurons of the submucosal plexus), HuC/D and S100β was performed in the submucosal plexus. The density (neurons per area) of submucosal neurons positive for the P2X7 receptor, calbindin, calretinin and HuC/D decreased by 21%, 34%, 8.2% and 28%, respectively, in the treated group. In addition, the density of enteric glial cells in the submucosal plexus decreased by 33%. The profile areas of calbindin-immunoreactive neurons decreased by 25%. Histological analysis revealed increased lamina propria and decreased collagen in the colitis group. This study demonstrated that ulcerative colitis affected secretory and vasodilatory neurons, IPANs and enteric glia of the submucosal plexus expressing the P2X7 receptor.
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20
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Alcaino C, Knutson K, Gottlieb PA, Farrugia G, Beyder A. Mechanosensitive ion channel Piezo2 is inhibited by D-GsMTx4. Channels (Austin) 2017; 11:245-253. [PMID: 28085630 DOI: 10.1080/19336950.2017.1279370] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Enterochromaffin (EC) cells are the primary mechanosensors of the gastrointestinal (GI) epithelium. In response to mechanical stimuliEC cells release serotonin (5-hydroxytryptamine; 5-HT). The molecular details ofEC cell mechanosensitivity are poorly understood. Recently, our group found that human and mouseEC cells express the mechanosensitive ion channel Piezo2. The mechanosensitive currents in a humanEC cell model QGP-1 were blocked by the mechanosensitive channel blocker D-GsMTx4. In the present study we aimed to characterize the effects of the mechanosensitive ion channel inhibitor spider peptide D-GsMTx4 on the mechanically stimulated currents from both QGP-1 and human Piezo2 transfected HEK-293 cells. We found co-localization of 5-HT and Piezo2 in QGP-1 cells by immunohistochemistry. QGP-1 mechanosensitive currents had biophysical properties similar to dose-dependently Piezo2 and were inhibited by D-GsMTx4. In response to direct displacement of cell membranes, human Piezo2 transiently expressed in HEK-293 cells produced robust rapidly activating and inactivating inward currents. D-GsMTx4 reversibly and dose-dependently inhibited both the potency and efficacy of Piezo2 currents in response to mechanical force. Our data demonstrate an effective inhibition of Piezo2 mechanosensitive currents by the spider peptide D-GsMTx4.
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Affiliation(s)
- Constanza Alcaino
- a Department of Physiology & Biomedical Engineering, Enteric Neuroscience Program, Division of Gastroenterology & Hepatology , Mayo Clinic , Rochester , MN , USA
| | - Kaitlyn Knutson
- a Department of Physiology & Biomedical Engineering, Enteric Neuroscience Program, Division of Gastroenterology & Hepatology , Mayo Clinic , Rochester , MN , USA
| | - Philip A Gottlieb
- b Department of Physiology and Biophysics, Center for Single Molecule Biophysics , State University of New York , Buffalo , NY , USA
| | - Gianrico Farrugia
- b Department of Physiology and Biophysics, Center for Single Molecule Biophysics , State University of New York , Buffalo , NY , USA
| | - Arthur Beyder
- a Department of Physiology & Biomedical Engineering, Enteric Neuroscience Program, Division of Gastroenterology & Hepatology , Mayo Clinic , Rochester , MN , USA
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21
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Asano T, Tanaka KI, Tada A, Shimamura H, Tanaka R, Maruoka H, Takenaga M, Mizushima T. Aminophylline suppresses stress-induced visceral hypersensitivity and defecation in irritable bowel syndrome. Sci Rep 2017; 7:40214. [PMID: 28054654 PMCID: PMC5214462 DOI: 10.1038/srep40214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/05/2016] [Indexed: 02/08/2023] Open
Abstract
Pharmacological therapy for irritable bowel syndrome (IBS) has not been established. In order to find candidate drugs for IBS with diarrhea (IBS-D), we screened a compound library of drugs clinically used for their ability to prevent stress-induced defecation and visceral hypersensitivity in rats. We selected the bronchodilator aminophylline from this library. Using a specific inhibitor for each subtype of adenosine receptors (ARs) and phosphodiesterases (PDEs), we found that both A2BARs and PDE4 are probably mediated the inhibitory effect of aminophylline on wrap restraint stress (WRS)-induced defecation. Aminophylline suppressed maternal separation- and acetic acid administration-induced visceral hypersensitivity to colorectal distension (CRD), which was mediated by both A2AARs and A2BARs. We propose that aminophylline is a candidate drug for IBS-D because of its efficacy in both of stress-induced defecation and visceral hypersensitivity, as we observed here, and because it is clinically safe.
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Affiliation(s)
- Teita Asano
- Institute of Medical Science, St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki 216-8512, Japan
| | - Ken-ichiro Tanaka
- Laboratory of Bio-Analytical Chemistry, Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-2αhinmachi, Nishitokyo-shi, 202-8585, Japan
| | - Arisa Tada
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Hikaru Shimamura
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Rikako Tanaka
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Hiroki Maruoka
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Mitsuko Takenaga
- Institute of Medical Science, St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki 216-8512, Japan
| | - Tohru Mizushima
- LTT Bio-Pharma Co., Ltd, Shiodome Building 3F, 1-2-20 Kaigan, Minato-ku, Tokyo 105-0022, Japan
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22
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Linan-Rico A, Ochoa-Cortes F, Beyder A, Soghomonyan S, Zuleta-Alarcon A, Coppola V, Christofi FL. Mechanosensory Signaling in Enterochromaffin Cells and 5-HT Release: Potential Implications for Gut Inflammation. Front Neurosci 2016; 10:564. [PMID: 28066160 PMCID: PMC5165017 DOI: 10.3389/fnins.2016.00564] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022] Open
Abstract
Enterochromaffin (EC) cells synthesize 95% of the body 5-HT and release 5-HT in response to mechanical or chemical stimulation. EC cell 5-HT has physiological effects on gut motility, secretion and visceral sensation. Abnormal regulation of 5-HT occurs in gastrointestinal disorders and Inflammatory Bowel Diseases (IBD) where 5-HT may represent a key player in the pathogenesis of intestinal inflammation. The focus of this review is on mechanism(s) involved in EC cell "mechanosensation" and critical gaps in our knowledge for future research. Much of our knowledge and concepts are from a human BON cell model of EC, although more recent work has included other cell lines, native EC cells from mouse and human and intact mucosa. EC cells are "mechanosensors" that respond to physical forces generated during peristaltic activity by translating the mechanical stimulus (MS) into an intracellular biochemical response leading to 5-HT and ATP release. The emerging picture of mechanosensation includes Piezo 2 channels, caveolin-rich microdomains, and tight regulation of 5-HT release by purines. The "purinergic hypothesis" is that MS releases purines to act in an autocrine/paracrine manner to activate excitatory (P2Y1, P2Y4, P2Y6, and A2A/A2B) or inhibitory (P2Y12, A1, and A3) receptors to regulate 5-HT release. MS activates a P2Y1/Gαq/PLC/IP3-IP3R/SERCA Ca2+signaling pathway, an A2A/A2B-Gs/AC/cAMP-PKA signaling pathway, an ATP-gated P2X3 channel, and an inhibitory P2Y12-Gi/o/AC-cAMP pathway. In human IBD, P2X3 is down regulated and A2B is up regulated in EC cells, but the pathophysiological consequences of abnormal mechanosensory or purinergic 5-HT signaling remain unknown. EC cell mechanosensation remains poorly understood.
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Affiliation(s)
- Andromeda Linan-Rico
- Department of Anesthesiology, Wexner Medical Center at Ohio State UniversityColumbus, OH, USA; CONACYT-Centro Universitario de Investigaciones Biomedicas, University of ColimaColima, Mexico
| | - Fernando Ochoa-Cortes
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Arthur Beyder
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Physiology and Biomedical Engineering, Mayo Clinic Rochester, MN, USA
| | - Suren Soghomonyan
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Alix Zuleta-Alarcon
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
| | - Vincenzo Coppola
- SBS-Cancer Biology and Genetics, Ohio State University Columbus, OH, USA
| | - Fievos L Christofi
- Department of Anesthesiology, Wexner Medical Center at Ohio State University Columbus, OH, USA
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23
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Wang F, Knutson K, Alcaino C, Linden DR, Gibbons SJ, Kashyap P, Grover M, Oeckler R, Gottlieb PA, Li HJ, Leiter AB, Farrugia G, Beyder A. Mechanosensitive ion channel Piezo2 is important for enterochromaffin cell response to mechanical forces. J Physiol 2016; 595:79-91. [PMID: 27392819 DOI: 10.1113/jp272718] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/29/2016] [Indexed: 12/31/2022] Open
Abstract
KEY POINTS The gastrointestinal epithelial enterochromaffin (EC) cell synthesizes the vast majority of the body's serotonin. As a specialized mechanosensor, the EC cell releases this serotonin in response to mechanical forces. However, the molecular mechanism of EC cell mechanotransduction is unknown. In the present study, we show, for the first time, that the mechanosensitive ion channel Piezo2 is specifically expressed by the human and mouse EC cells. Activation of Piezo2 by mechanical forces results in a characteristic ionic current, the release of serotonin and stimulation of gastrointestinal secretion. Piezo2 inhibition by drugs or molecular knockdown decreases mechanosensitive currents, serotonin release and downstream physiological effects. The results of the present study suggest that the mechanosensitive ion channel Piezo2 is specifically expressed by the EC cells of the human and mouse small bowel and that it is important for EC cell mechanotransduction. ABSTRACT The enterochromaffin (EC) cell in the gastrointestinal (GI) epithelium is the source of nearly all systemic serotonin (5-hydroxytryptamine; 5-HT), which is an important neurotransmitter and endocrine, autocrine and paracrine hormone. The EC cell is a specialized mechanosensor, and it is well known that it releases 5-HT in response to mechanical forces. However, the EC cell mechanotransduction mechanism is unknown. The present study aimed to determine whether Piezo2 is involved in EC cell mechanosensation. Piezo2 mRNA was expressed in human jejunum and mouse mucosa from all segments of the small bowel. Piezo2 immunoreactivity localized specifically within EC cells of human and mouse small bowel epithelium. The EC cell model released 5-HT in response to stretch, and had Piezo2 mRNA and protein, as well as a mechanically-sensitive inward non-selective cation current characteristic of Piezo2. Both inward currents and 5-HT release were inhibited by Piezo2 small interfering RNA and antagonists (Gd3+ and D-GsMTx4). Jejunum mucosal pressure increased 5-HT release and short-circuit current via submucosal 5-HT3 and 5-HT4 receptors. Pressure-induced secretion was inhibited by the mechanosensitive ion channel antagonists gadolinium, ruthenium red and D-GsMTx4. We conclude that the EC cells in the human and mouse small bowel GI epithelium selectively express the mechanosensitive ion channel Piezo2, and also that activation of Piezo2 by force leads to inward currents, 5-HT release and an increase in mucosal secretion. Therefore, Piezo2 is critical to EC cell mechanosensitivity and downstream physiological effects.
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Affiliation(s)
- Fan Wang
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.,Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 300 Yanchang Middle Road, Shanghai, PR China
| | - Kaitlyn Knutson
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Constanza Alcaino
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - David R Linden
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Simon J Gibbons
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Purna Kashyap
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Madhusudan Grover
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Richard Oeckler
- Division of Pulmonary and Critical Care, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Philip A Gottlieb
- Department of Physiology and Biophysics, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY, USA
| | - Hui Joyce Li
- Department of Medicine, Division of Gastroenterology, University of Massachusetts Medical School, 55 N Lake Ave, Worcester, MA, USA
| | - Andrew B Leiter
- Department of Medicine, Division of Gastroenterology, University of Massachusetts Medical School, 55 N Lake Ave, Worcester, MA, USA
| | - Gianrico Farrugia
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Arthur Beyder
- Enteric Neuroscience Program, Division of Gastroenterology & Hepatology, Departments of Medicine and Physiology & Biomedical Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
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24
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Ochoa-Cortes F, Turco F, Linan-Rico A, Soghomonyan S, Whitaker E, Wehner S, Cuomo R, Christofi FL. Enteric Glial Cells: A New Frontier in Neurogastroenterology and Clinical Target for Inflammatory Bowel Diseases. Inflamm Bowel Dis 2016; 22:433-49. [PMID: 26689598 PMCID: PMC4718179 DOI: 10.1097/mib.0000000000000667] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 08/29/2015] [Indexed: 12/12/2022]
Abstract
The word "glia" is derived from the Greek word "γλoια," glue of the enteric nervous system, and for many years, enteric glial cells (EGCs) were believed to provide mainly structural support. However, EGCs as astrocytes in the central nervous system may serve a much more vital and active role in the enteric nervous system, and in homeostatic regulation of gastrointestinal functions. The emphasis of this review will be on emerging concepts supported by basic, translational, and/or clinical studies, implicating EGCs in neuron-to-glial (neuroglial) communication, motility, interactions with other cells in the gut microenvironment, infection, and inflammatory bowel diseases. The concept of the "reactive glial phenotype" is explored as it relates to inflammatory bowel diseases, bacterial and viral infections, postoperative ileus, functional gastrointestinal disorders, and motility disorders. The main theme of this review is that EGCs are emerging as a new frontier in neurogastroenterology and a potential therapeutic target. New technological innovations in neuroimaging techniques are facilitating progress in the field, and an update is provided on exciting new translational studies. Gaps in our knowledge are discussed for further research. Restoring normal EGC function may prove to be an efficient strategy to dampen inflammation. Probiotics, palmitoylethanolamide (peroxisome proliferator-activated receptor-α), interleukin-1 antagonists (anakinra), and interventions acting on nitric oxide, receptor for advanced glycation end products, S100B, or purinergic signaling pathways are relevant clinical targets on EGCs with therapeutic potential.
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Affiliation(s)
| | - Fabio Turco
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
- Department of Clinical and Experimental Medicine, Gastroenterological Unit, “Federico II” University of Naples, Naples, Italy; and
| | | | - Suren Soghomonyan
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
| | - Emmett Whitaker
- Department of Anesthesiology, The Ohio State University, Columbus, Ohio
| | - Sven Wehner
- Department of Surgery, University of Bonn, Bonn, Germany
| | - Rosario Cuomo
- Department of Clinical and Experimental Medicine, Gastroenterological Unit, “Federico II” University of Naples, Naples, Italy; and
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25
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Camilleri M, Carlson P, Acosta A, Busciglio I. Colonic mucosal gene expression and genotype in irritable bowel syndrome patients with normal or elevated fecal bile acid excretion. Am J Physiol Gastrointest Liver Physiol 2015; 309:G10-20. [PMID: 25930081 PMCID: PMC4491506 DOI: 10.1152/ajpgi.00080.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/28/2015] [Indexed: 02/08/2023]
Abstract
The mucosal gene expression in rectosigmoid mucosa (RSM) in irritable bowel syndrome with diarrhea (IBS-D) is unknown. Our objectives were, first, to study mRNA expression [by RT(2) PCR of 19 genes pertaining to tight junctions, immune activation, intestinal ion transport and bile acid (BA) homeostasis] in RSM in IBS-D patients (n = 47) and healthy controls (n = 17) and study expression of a selected protein (PDZD3) in 10 IBS-D patients and 4 healthy controls; second, to assess RSM mRNA expression according to genotype and fecal BA excretion (high ≥ 2,337 μmol/48 h); and third, to determine whether genotype or mucosal mRNA expression is associated with colonic transit or BA parameters. Fold changes were corrected for false detection rate for 19 genes studied (P < 0.00263). In RSM in IBS-D patients compared with controls, mRNA expression of GUC2AB, PDZD3, and PR2Y4 was increased, whereas CLDN1 and FN1 were decreased. One immune-related gene was upregulated (C4BP4) and one downregulated (CCL20). There was increased expression of a selected ion transport protein (PDZD3) on immunohistochemistry and Western blot in IBS-D compared with controls (P = 0.02). There were no significant differences in mucosal mRNA in 20 IBS-D patients with high compared with 27 IBS-D patients with normal BA excretion. GPBAR1 (P < 0.05) was associated with colonic transit. We concluded that mucosal ion transport mRNA (for several genes and PDZD3 protein) is upregulated and barrier protein mRNA downregulated in IBS-D compared with healthy controls, independent of genotype. There are no differences in gene expression in IBS-D with high compared with normal fecal BA excretion.
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Affiliation(s)
- Michael Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), Mayo Clinic, Rochester, Minnesota
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26
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Wang GD, Wang XY, Liu S, Xia Y, Zou F, Qu M, Needleman BJ, Mikami DJ, Wood JD. β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum. Am J Physiol Gastrointest Liver Physiol 2015; 308:G955-63. [PMID: 25813057 PMCID: PMC4451321 DOI: 10.1152/ajpgi.00430.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/18/2015] [Indexed: 01/31/2023]
Abstract
Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions.
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Affiliation(s)
- Guo-Du Wang
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
| | - Xi-Yu Wang
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
| | - Sumei Liu
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
| | - Yun Xia
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio; ,2Department of Anesthesiology, College of Medicine, The Ohio State University, Columbus, Ohio; and
| | - Fei Zou
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
| | - Meihua Qu
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
| | - Bradley J. Needleman
- 3Department of Surgery, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Dean J. Mikami
- 3Department of Surgery, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Jackie D. Wood
- 1Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, Ohio;
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27
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Enteric purinergic signaling: Shaping the "brain in the gut". Neuropharmacology 2015; 95:477-8. [PMID: 25981956 DOI: 10.1016/j.neuropharm.2015.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 04/09/2015] [Indexed: 12/26/2022]
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28
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Liñán-Rico A, Wunderlich JE, Enneking JT, Tso DR, Grants I, Williams KC, Otey A, Michel K, Schemann M, Needleman B, Harzman A, Christofi FL. Neuropharmacology of purinergic receptors in human submucous plexus: Involvement of P2X₁, P2X₂, P2X₃ channels, P2Y and A₃ metabotropic receptors in neurotransmission. Neuropharmacology 2015; 95:83-99. [PMID: 25724083 DOI: 10.1016/j.neuropharm.2015.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/11/2015] [Accepted: 02/15/2015] [Indexed: 02/08/2023]
Abstract
RATIONALE The role of purinergic signaling in human ENS is not well understood. We sought to further characterize the neuropharmacology of purinergic receptors in human ENS and test the hypothesis that endogenous purines are critical regulators of neurotransmission. EXPERIMENTAL APPROACH LSCM-Fluo-4/(Ca(2+))-imaging of postsynaptic Ca(2+) transients (PSCaTs) was used as a reporter of synaptic transmission evoked by fiber tract electrical stimulation in human SMP surgical preparations. Pharmacological analysis of purinergic signaling was done in 1,556 neurons (identified by HuC/D-immunoreactivity) in 235 ganglia from 107 patients; P2XR-immunoreactivity was evaluated in 19 patients. Real-time MSORT (Di-8-ANEPPS) imaging tested effects of adenosine on fast excitatory synaptic potentials (fEPSPs). RESULTS Synaptic transmission is sensitive to pharmacological manipulations that alter accumulation of extracellular purines: Apyrase blocks PSCaTs in a majority of neurons. An ecto-NTPDase-inhibitor 6-N,N-diethyl-D-β,γ-dibromomethyleneATP or adenosine deaminase augments PSCaTs. Blockade of reuptake/deamination of eADO inhibits PSCaTs. Adenosine inhibits fEPSPs and PSCaTs (IC50 = 25 µM), sensitive to MRS1220-antagonism (A3AR). A P2Y agonist ADPβS inhibits PSCaTs (IC50 = 111 nM) in neurons without stimulatory ADPbS responses (EC50 = 960 nM). ATP or a P2X1,2,2/3 (α,β-MeATP) agonist evokes fast, slow, biphasic Ca(2+) transients or Ca(2+) oscillations (ATP,EC50 = 400 mM). PSCaTs are sensitive to P2X1 antagonist NF279. Low (20 nM) or high (5 µM) concentrations of P2X antagonist TNP-ATP block PSCaTs in different neurons; proportions of neurons with P2XR-immunoreactivity follow the order P2X2 > P2X1 >> P2X3; P2X1 + P2X2 and P2X3 + P2X2 are co-localized. RT-PCR identified mRNA-transcripts for P2X1-7, P2Y1,2,12-14R. CONCLUSIONS Purines are critical regulators of neurotransmission in human ENS. Purinergic signaling involves P2X1, P2X2, P2X3 channels, P2X1 + P2X2 co-localization and inhibitory P2Y or A3 receptors. These are potential novel therapeutic targets for neurogastroenterology.
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Affiliation(s)
- A Liñán-Rico
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - J E Wunderlich
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - J T Enneking
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - D R Tso
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - I Grants
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - K C Williams
- Division of Pediatric Gastroenterology, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - A Otey
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - K Michel
- Human Biology, Technische Universität München, Freising, Germany
| | - M Schemann
- Human Biology, Technische Universität München, Freising, Germany
| | - B Needleman
- Department of Surgery, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - A Harzman
- Department of Surgery, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - F L Christofi
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA.
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29
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Antonioli L, Fornai M, Awwad O, Giustarini G, Pellegrini C, Tuccori M, Caputi V, Qesari M, Castagliuolo I, Brun P, Giron MC, Scarpignato C, Blandizzi C, Colucci R. Role of the A(2B) receptor-adenosine deaminase complex in colonic dysmotility associated with bowel inflammation in rats. Br J Pharmacol 2014; 171:1314-29. [PMID: 24286264 DOI: 10.1111/bph.12539] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 11/08/2013] [Accepted: 11/19/2013] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Adenosine A(2B) receptors regulate several physiological enteric functions. However, their role in the pathophysiology of intestinal dysmotility associated with inflammation has not been elucidated. Hence, we investigated the expression of A2B receptors in rat colon and their role in the control of cholinergic motility in the presence of bowel inflammation. EXPERIMENTAL APPROACH Colitis was induced by 2,4-dinitrobenzenesulfonic acid (DNBS). Colonic A(2B) receptor expression and localization were examined by RT-PCR and immunofluorescence. The interaction between A(2B) receptors and adenosine deaminase was assayed by immunoprecipitation. The role of A(2B) receptors in the control of colonic motility was examined in functional experiments on longitudinal muscle preparations (LMPs). KEY RESULTS A(2B) receptor mRNA was present in colon from both normal and DNBS-treated rats but levels were increased in the latter. A(2B) receptors were predominantly located in the neuromuscular layer, but, in the presence of colitis, were increased mainly in longitudinal muscle. Functionally, the A(2B) receptor antagonist MRS 1754 enhanced both electrically-evoked and carbachol-induced cholinergic contractions in normal LMPs, but was less effective in inflamed tissues. The A(2B) receptor agonist NECA decreased colonic cholinergic motility, with increased efficacy in inflamed LMP. Immunoprecipitation and functional tests revealed a link between A(2B) receptors and adenosine deaminase, which colocalize in the neuromuscular compartment. CONCLUSIONS AND IMPLICATIONS Under normal conditions, endogenous adenosine modulates colonic motility via A2B receptors located in the neuromuscular compartment. In the presence of colitis, this inhibitory control is impaired due to a link between A2B receptors and adenosine deaminase, which catabolizes adenosine, thus preventing A(2B) receptor activation.
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Affiliation(s)
- L Antonioli
- Division of Pharmacology and Chemotherapy, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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30
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Ochoa-Cortes F, Liñán-Rico A, Jacobson KA, Christofi FL. Potential for developing purinergic drugs for gastrointestinal diseases. Inflamm Bowel Dis 2014; 20:1259-87. [PMID: 24859298 PMCID: PMC4340257 DOI: 10.1097/mib.0000000000000047] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Treatments for inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), functional dyspepsia, or motility disorders are not adequate, and purinergic drugs offer exciting new possibilities. Gastrointestinal symptoms that could be targeted for therapy include visceral pain, inflammatory pain, dysmotility, constipation, and diarrhea. The focus of this review is on the potential for developing purinergic drugs for clinical trials to treat gastrointestinal symptoms. Purinergic receptors are divided into adenosine P1 (A(1), A(2A), A(2B), A(3)), ionotropic ATP-gated P2X ion channel (P2X(1-7)), or metabotropic P2Y(1,2,4,6,11-14) receptors. There is good experimental evidence for targeting A(2A), A(2B), A(3), P2X(7), and P2X(3) receptors or increasing endogenous adenosine levels to treat IBD, inflammatory pain, IBS/visceral pain, inflammatory diarrhea, and motility disorders. Purine genes are also potential biomarkers of disease. Advances in medicinal chemistry have an accelerated pace toward clinical trials: Methotrexate and sulfasalazine, used to treat IBD, act by stimulating CD73-dependent adenosine production. ATP protects against NSAID-induced enteropathy and has pain-relieving properties in humans. A P2X(7)R antagonist AZD9056 is in clinical trials for Crohn's disease. A(3) adenosine receptor drugs target inflammatory diseases (e.g., CF101, CF102). Dipyridamole, a nucleoside uptake inhibitor, is in trials for endotoxemia. Drugs for pain in clinical trials include P2X(3)/P2X(2/3) (AF-219) and P2X(7) (GSK1482160) antagonists and A(1) (GW493838) or A(2A) (BVT.115959) agonists. Iberogast is a phytopharmacon targeting purine mechanisms with efficacy in IBS and functional dyspepsia. Purinergic drugs have excellent safety/efficacy profile for prospective clinical trials in IBD, IBS, functional dyspepsia, and inflammatory diarrhea. Genetic polymorphisms and caffeine consumption may affect susceptibility to treatment. Further studies in animals can clarify mechanisms and test new generation drugs. Finally, there is still a huge gap in our knowledge of human pathophysiology of purinergic signaling.
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Affiliation(s)
- Fernando Ochoa-Cortes
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Andromeda Liñán-Rico
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Kenneth A. Jacobson
- Laboratory of Bioorganic Chemistry & Molecular Recognition Section, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health
| | - Fievos L. Christofi
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
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Burnstock G. Purinergic signalling in the gastrointestinal tract and related organs in health and disease. Purinergic Signal 2014; 10:3-50. [PMID: 24307520 PMCID: PMC3944042 DOI: 10.1007/s11302-013-9397-9] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 01/04/2023] Open
Abstract
Purinergic signalling plays major roles in the physiology and pathophysiology of digestive organs. Adenosine 5'-triphosphate (ATP), together with nitric oxide and vasoactive intestinal peptide, is a cotransmitter in non-adrenergic, non-cholinergic inhibitory neuromuscular transmission. P2X and P2Y receptors are widely expressed in myenteric and submucous enteric plexuses and participate in sympathetic transmission and neuromodulation involved in enteric reflex activities, as well as influencing gastric and intestinal epithelial secretion and vascular activities. Involvement of purinergic signalling has been identified in a variety of diseases, including inflammatory bowel disease, ischaemia, diabetes and cancer. Purinergic mechanosensory transduction forms the basis of enteric nociception, where ATP released from mucosal epithelial cells by distension activates nociceptive subepithelial primary afferent sensory fibres expressing P2X3 receptors to send messages to the pain centres in the central nervous system via interneurons in the spinal cord. Purinergic signalling is also involved in salivary gland and bile duct secretion.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Patel BA. Mucosal adenosine triphosphate mediates serotonin release from ileal but not colonic guinea pig enterochromaffin cells. Neurogastroenterol Motil 2014; 26:237-46. [PMID: 24188286 DOI: 10.1111/nmo.12254] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/26/2013] [Indexed: 12/27/2022]
Abstract
BACKGROUND Mechanical stimulation of the mucosal epithelium results in increased serotonin (5-HT) release from enterochromaffin (EC) cells. Little is known about how this process varies in different regions of the intestinal tract; however, purines are felt to play a role. We studied the relationship between mechanical stimulation, adenosine triphosphate (ATP), and 5-HT release from ileal and colonic mucosal tissue. METHODS Amperometric recordings of ATP and 5-HT were carried out using an ATP biosensor and boron-doped diamond microelectrode. Levels of extracellular ATP and 5-HT were monitored using high performance liquid chromatography. KEY RESULTS Under basal conditions, 5-HT levels were significantly decreased in the ileum (p < 0.001) but not the colon in the presence of the P2 antagonist suramin (100 μM). Ecto-ATPase inhibitor ARL67156 (10 μM) elevated ATP levels in the ileum and colon (both p < 0.001), but only 5-HT levels in the ileum (p < 0.001). Exogenous ATP increased 5-HT release in the presence of tetrodotoxin in the ileum (p < 0.001), but had not effect in the colon. Mechanical stimulation increased levels of 5-HT in the ileum (p < 0.001) and colon (p < 0.01), but levels returned to baseline in the presence of suramin and MRS2179 in the ileum. The onset of 5-HT release was delayed following mechanical stimulation. The rise time of the ATP response was quicker than that of 5-HT during mechanical stimulation. CONCLUSIONS & INFERENCES During mechanical stimulation of the mucosal epithelium, ATP mediates 5-HT release from EC cells in the ileum, but not the colon. Mucosal 5-HT signaling following mechanical stimulation is varied in different regions of the intestinal tract.
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Affiliation(s)
- B A Patel
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
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Purinergic autocrine regulation of mechanosensitivity and serotonin release in a human EC model: ATP-gated P2X3 channels in EC are downregulated in ulcerative colitis. Inflamm Bowel Dis 2013; 19:2366-79. [PMID: 23917247 PMCID: PMC4037929 DOI: 10.1097/mib.0b013e31829ecf4d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Alterations in 5-hydroxytryptamine (HT) signaling in inflamed gut may contribute to pathogenesis of inflammatory bowel diseases. Adenosine 5'-triphosphate (ATP) regulates mucosal-mechanosensory reflexes and ATP receptors are sensitive to mucosal inflammation. Yet, it remains unknown whether ATP can modulate 5-HT signaling in enterochromaffin cells (EC). We tested the novel purinergic hypothesis that ATP is a critical autocrine regulator of EC mechanosensitivity and whether EC expression of ATP-gated P2X3-ion channels is altered in inflammatory bowel diseases. METHODS Laser confocal (fluo-4) Ca imaging was performed in 1947 BON cells. Chemical stimulation or mechanical stimulation (MS) was used to study 5-HT or ATP release in human BON or surgical mucosal specimens, and purine receptors by reverse transcription-polymerase chain reaction, Western Blot, or P2X3-immunoreactivity in BON or 5-HT human EC (hEC) in 11 control and 10 severely inflamed ulcerative colitis (UC) cases. RESULTS ATP or MS triggered Ca-transients or 5-HT release in BON. ATP or adenosine diphosphate increased 5-HT release 5-fold. MS caused ATP release, detected after 5'ecto-ATPase inhibition by ARL67156. ARL67156 augmented and apyrase blocked Ca/5-HT mechanosensitive responses. 2-Methyl-thio-adenosine diphosphate 5'-monophosphate-evoked (P2Y1,12) or mechanically-evoked responses were blocked or augmented by a P2Y1,12 antagonist, MRS2179, in different cells or inhibited by U73122. A P2Y12 antagonist, 2MeSAMP, augmented responses. A P2X1,3 agonist, α,β-MeATP, triggered Ca responses, whereas a P2X1,2/3,3 antagonist, 2',3'-O-(2,4,6-trinitrophenyl)-ATP, blocked mechanical responses or cell-surface 5'ATP- labeling. In hEC, α,β-MeATP stimulated 5-HT release. In UC, P2X3-immunoreactivity decreased from 15% to 0.2% of 5-HThECs. Human mucosa and BON expressed P2X1, P2X3, P2X4, P2X5, P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, and P2Y12R-messenger RNA transcripts. CONCLUSIONS ATP is a critical determinant of mechanosensation and 5-HT release via autocrine activation of slow P2Y1-phospholipase C/inositol-1,4,5-triphosphate-Ca or inhibitory P2Y12-purinergic pathways, and fast ATP-gated P2X3-channels. UC downregulation of P2X3-channels (or A2B) is postulated to mediate abnormal 5-HT signaling.
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Peri LE, Sanders KM, Mutafova-Yambolieva VN. Differential expression of genes related to purinergic signaling in smooth muscle cells, PDGFRα-positive cells, and interstitial cells of Cajal in the murine colon. Neurogastroenterol Motil 2013; 25:e609-20. [PMID: 23809506 PMCID: PMC3735650 DOI: 10.1111/nmo.12174] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 05/26/2013] [Indexed: 12/19/2022]
Abstract
BACKGROUND Purinergic signaling provides regulation of colonic motility. Smooth muscle cells (SMC), interstitial cells of Cajal (ICC), and platelet-derived growth factor receptor α-positive (PDGFRα(+) ) cells are electrically coupled and form a functional (SIP) syncytium that constitutes the receptive field for motor neurotransmitters in the tunica muscularis. Each cell type in the SIP syncytium has specialized functions in mediating motor neurotransmission. We compared gene transcripts for purinergic receptors and membrane-bound enzymes for purine degradation expressed by each cell type of the SIP syncytium. METHODS Fluorescence-activated cell sorting (FACS) was used to purify SMC, ICC, and PDGFRα(+) cells from mixed cell populations of colonic muscles dispersed from reporter strains of mice with constitutive expression of green fluorescent proteins. Differential expression of functional groups of genes related to purinergic signaling was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). KEY RESULTS We detected marked phenotypic differences among SMC, ICC, and PDGFRα(+) cells. Substantial numbers of genes of importance in purinergic neurotransmission were enriched in PDGFRα(+) cells in relation to SMC and ICC. Notably, genes related to mediating effects and extracellular biotransformation of enteric purinergic inhibitory neurotransmitters were strongly expressed by PDGFRα(+) cells. CONCLUSIONS & INFERENCES Our results demonstrate differential expression of genes for proteins involved in purinergic signaling in the SIP syncytium. These results may further clarify the specific functions of each cell type, identify novel biomarkers for postjunctional cells, and provide hypotheses for further studies to understand the physiological roles of cells of the SIP syncytium.
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Affiliation(s)
- L. E. Peri
- Department of Physiology and Cell Biology; University of Nevada School of Medicine; Reno; NV; USA
| | - K. M. Sanders
- Department of Physiology and Cell Biology; University of Nevada School of Medicine; Reno; NV; USA
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Influence of carbohydrate on serum caffeine concentrations following caffeine ingestion. J Sci Med Sport 2013; 16:343-7. [DOI: 10.1016/j.jsams.2012.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 07/25/2012] [Accepted: 08/09/2012] [Indexed: 11/17/2022]
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Antonioli L, Colucci R, Pellegrini C, Giustarini G, Tuccori M, Blandizzi C, Fornai M. The role of purinergic pathways in the pathophysiology of gut diseases: pharmacological modulation and potential therapeutic applications. Pharmacol Ther 2013; 139:157-88. [PMID: 23588157 DOI: 10.1016/j.pharmthera.2013.04.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 03/15/2013] [Indexed: 02/08/2023]
Abstract
Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets.
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Affiliation(s)
- Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Italy.
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Skinner TL, Jenkins DG, Taaffe DR, Leveritt MD, Coombes JS. Coinciding exercise with peak serum caffeine does not improve cycling performance. J Sci Med Sport 2013; 16:54-9. [DOI: 10.1016/j.jsams.2012.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/16/2012] [Accepted: 04/22/2012] [Indexed: 10/28/2022]
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Furuya S, Furuya K. Roles of substance P and ATP in the subepithelial fibroblasts of rat intestinal villi. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:133-89. [PMID: 23809436 DOI: 10.1016/b978-0-12-407696-9.00003-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ingestion of food and water induces chemical and mechanical signals that trigger peristaltic reflexes and also villous movement in the gut. In the intestinal villi, subepithelial fibroblasts under the epithelium form contractile cellular networks and closely contact to the varicosities of substance P and nonsubstance P afferent neurons. Subepithelial fibroblasts of the duodenal villi possess purinergic receptor P2Y1 and tachykinin receptor NK1. ATP and substance P induce increase in intracellular Ca(2+) and cell contraction in subepithelial fibroblasts. They are highly mechanosensitive and release ATP by mechanical stimuli. Released ATP spreads to form an ATP "cloud" with nearly 1μM concentration and activates the surroundings via P2Y1 and afferent neurons via P2X receptors. These findings suggest that villous subepithelial fibroblasts and afferent neurons interact via ATP and substance P. This mutual interaction may play important roles in the signal transduction of mechano reflex pathways including a coordinate villous movement and also in the maturation of the structure and function of the intestinal villi.
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Affiliation(s)
- Sonoko Furuya
- Section of Brain Structure Information, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan.
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Roberts JA, Lukewich MK, Sharkey KA, Furness JB, Mawe GM, Lomax AE. The roles of purinergic signaling during gastrointestinal inflammation. Curr Opin Pharmacol 2012; 12:659-66. [PMID: 23063457 DOI: 10.1016/j.coph.2012.09.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 09/17/2012] [Accepted: 09/19/2012] [Indexed: 02/09/2023]
Abstract
Extracellular purines play important roles as neurotransmitters and paracrine mediators in the gastrointestinal (GI) tract. Inflammation of the GI tract causes marked changes in the release and extracellular catabolism of purines, and can modulate purinoceptor expression and/or signaling. The functional consequences of this include suppression of the purinergic component of inhibitory neuromuscular and neurovascular transmission, increased release of purines from immune and epithelial cells, loss of enteric neurons to damage through P2X(7) purinoceptors, and enhanced activation of pain fibres. The purinergic system represents an important target for drug therapies that may improve GI inflammation and its consequences.
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Affiliation(s)
- Jane A Roberts
- Department of Anatomy and Neurobiology, University of Vermont, Burlington, VT, USA
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Ingersoll SA, Laroui H, Kolachala VL, Wang L, Garg P, Denning T, Gewirtz A, Merlin D, Sitaraman SV. A(₂B)AR expression in non-immune cells plays an important role in the development of murine colitis. Dig Liver Dis 2012; 44:819-26. [PMID: 22721840 PMCID: PMC3436952 DOI: 10.1016/j.dld.2012.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/10/2012] [Accepted: 05/16/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND Adenosine, an endogenous purine nucleoside, is involved in several physiological functions. We have previously shown that A(2B)AR plays a pro-inflammatory role during colitis. AIMS Our goals were to determine if A(2B)AR expression was necessary on immune cells/non-immune cells during colitis and if A(2B)AR was a suitable target for treating intestinal inflammation. METHODS Wild-type and A(2B)AR knockout mice were utilized in bone marrow transplants to explore the importance of immune/non-immune A(2B)AR expression during the development of colitis. Additionally, a T-cell transfer model of colitis was used in Rag1 knockout or A(2B)AR/RAG1 double knockout recipients. Finally, A(2B)AR small interfering RNA nanoparticles were administered to dextran sodium sulphate-treated mice. RESULTS Wild-type mice receiving wild-type or knockout bone marrow developed severe colitis after dextran sodium sulphate treatment, whereas colitis was significantly attenuated in knockout mice receiving wild-type or knockout bone marrow. Colitis induced in Rag1 knockout animals was attenuated in A(2B)AR/RAG1 double knockout recipients. Animals receiving nanoparticles exhibited attenuated parameters of colitis severity compared to mice receiving control nanoparticles. CONCLUSIONS Our results suggest that A(2B)AR on non-immune cells plays an important role for the induction of colitis and targeting A(2B)AR expression during colitis may be useful for alleviating symptoms of intestinal inflammation.
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Affiliation(s)
- Sarah A. Ingersoll
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, GA,Veterans Affairs Medical Center, Decatur, GA
| | - Hamed Laroui
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, GA
| | | | - Lixin Wang
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, GA,Veterans Affairs Medical Center, Decatur, GA
| | - Pallavi Garg
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, GA
| | - Timothy Denning
- School of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Andrew Gewirtz
- Center for Inflammation, Immunity & Infection, Department of Biology, Georgia State University, Atlanta, GA
| | - Didier Merlin
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, GA,Veterans Affairs Medical Center, Decatur, GA
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Reimann F, Tolhurst G, Gribble FM. G-protein-coupled receptors in intestinal chemosensation. Cell Metab 2012; 15:421-31. [PMID: 22482725 DOI: 10.1016/j.cmet.2011.12.019] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 11/21/2011] [Accepted: 12/15/2011] [Indexed: 12/25/2022]
Abstract
Food intake is detected by the chemical senses of taste and smell and subsequently by chemosensory cells in the gastrointestinal tract that link the composition of ingested foods to feedback circuits controlling gut motility/secretion, appetite, and peripheral nutrient disposal. G-protein-coupled receptors responsive to a range of nutrients and other food components have been identified, and many are localized to intestinal chemosensory cells, eliciting hormonal and neuronal signaling to the brain and periphery. This review examines the role of G-protein-coupled receptors as signaling molecules in the gut, with a particular focus on pathways relevant to appetite and glucose homeostasis.
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Affiliation(s)
- Frank Reimann
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge, UK.
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Abstract
Mammalian taste buds use ATP as a neurotransmitter. Taste Receptor (type II) cells secrete ATP via gap junction hemichannels into the narrow extracellular spaces within a taste bud. This ATP excites primary sensory afferent fibers and also stimulates neighboring taste bud cells. Here we show that extracellular ATP is enzymatically degraded to adenosine within mouse vallate taste buds and that this nucleoside acts as an autocrine neuromodulator to selectively enhance sweet taste. In Receptor cells in a lingual slice preparation, Ca(2+) mobilization evoked by focally applied artificial sweeteners was significantly enhanced by adenosine (50 μM). Adenosine had no effect on bitter or umami taste responses, and the nucleoside did not affect Presynaptic (type III) taste cells. We also used biosensor cells to measure transmitter release from isolated taste buds. Adenosine (5 μM) enhanced ATP release evoked by sweet but not bitter taste stimuli. Using single-cell reverse transcriptase (RT)-PCR on isolated vallate taste cells, we show that many Receptor cells express the adenosine receptor, Adora2b, while Presynaptic (type III) and Glial-like (type I) cells seldom do. Furthermore, Adora2b receptors are significantly associated with expression of the sweet taste receptor subunit, Tas1r2. Adenosine is generated during taste stimulation mainly by the action of the ecto-5'-nucleotidase, NT5E, and to a lesser extent, prostatic acid phosphatase. Both these ecto-nucleotidases are expressed by Presynaptic cells, as shown by single-cell RT-PCR, enzyme histochemistry, and immunofluorescence. Our findings suggest that ATP released during taste reception is degraded to adenosine to exert positive modulation particularly on sweet taste.
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Abstract
Mammalian taste buds use ATP as a neurotransmitter. Taste Receptor (type II) cells secrete ATP via gap junction hemichannels into the narrow extracellular spaces within a taste bud. This ATP excites primary sensory afferent fibers and also stimulates neighboring taste bud cells. Here we show that extracellular ATP is enzymatically degraded to adenosine within mouse vallate taste buds and that this nucleoside acts as an autocrine neuromodulator to selectively enhance sweet taste. In Receptor cells in a lingual slice preparation, Ca(2+) mobilization evoked by focally applied artificial sweeteners was significantly enhanced by adenosine (50 μM). Adenosine had no effect on bitter or umami taste responses, and the nucleoside did not affect Presynaptic (type III) taste cells. We also used biosensor cells to measure transmitter release from isolated taste buds. Adenosine (5 μM) enhanced ATP release evoked by sweet but not bitter taste stimuli. Using single-cell reverse transcriptase (RT)-PCR on isolated vallate taste cells, we show that many Receptor cells express the adenosine receptor, Adora2b, while Presynaptic (type III) and Glial-like (type I) cells seldom do. Furthermore, Adora2b receptors are significantly associated with expression of the sweet taste receptor subunit, Tas1r2. Adenosine is generated during taste stimulation mainly by the action of the ecto-5'-nucleotidase, NT5E, and to a lesser extent, prostatic acid phosphatase. Both these ecto-nucleotidases are expressed by Presynaptic cells, as shown by single-cell RT-PCR, enzyme histochemistry, and immunofluorescence. Our findings suggest that ATP released during taste reception is degraded to adenosine to exert positive modulation particularly on sweet taste.
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Pharmacological characterization of uracil nucleotide-preferring P2Y receptors modulating intestinal motility: a study on mouse ileum. Purinergic Signal 2011; 8:275-85. [PMID: 22102167 DOI: 10.1007/s11302-011-9281-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 11/07/2011] [Indexed: 01/08/2023] Open
Abstract
We investigated the possible modulation of the intestinal contractility by uracil nucleotides (UTP and UDP), using as model the murine small intestine. Contractile activity of a mouse ileum longitudinal muscle was examined in vitro as changes in isometric tension. Transcripts encoding for uracil-sensitive receptors was investigated by RT-PCR. UDP induced muscular contractions, sensitive to PPADS, suramin, or MRS 2578, P2Y(6) receptor antagonist, and mimicked by PSB 0474, P2Y(6)-receptor agonist. UTP induced biphasic effects characterized by an early inhibition of the spontaneous contractile activity followed by muscular contraction. UTP excitatory effects were antagonized by PPADS, suramin, but not by MRS 2578, whilst the inhibitory effects were antagonized by PPADS but not by suramin or MRS 2578. UTPγS, P2Y(2)/(4) receptor agonist but not 2-thio-UTP, P2Y(2) receptor agonist, mimicked UTP effects. The inhibitory effects induced by UTP was abolished by ATP desensitization and increased by extracellular acidification. UDP or UTP responses were insensitive to TTX, atropine, or L-NAME antagonized by U-73122, inhibitor of phospholipase C (PLC) and preserved in the presence of nifedipine or low Ca(2+) solution. Transcripts encoding the uracil nucleotide-preferring receptors were expressed in mouse ileum. Functional postjunctional uracil-sensitive receptors are present in the longitudinal muscle of the mouse ileum. Activation of P2Y(6) receptors induces muscular contraction, whilst activation of P2Y(4) receptors leads to inhibition of the contractile activity. Indeed, the presence of atypical UTP-sensitive receptors leading to muscular contraction is suggested. All uracil-sensitive receptors are linked to the PLC pathway.
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Vieira C, Ferreirinha F, Silva I, Duarte-Araújo M, Correia-de-Sá P. Localization and function of adenosine receptor subtypes at the longitudinal muscle--myenteric plexus of the rat ileum. Neurochem Int 2011; 59:1043-55. [PMID: 21924311 DOI: 10.1016/j.neuint.2011.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/11/2011] [Accepted: 08/22/2011] [Indexed: 10/17/2022]
Abstract
Adenosine plays a dual role on acetylcholine (ACh) release from myenteric motoneurons via the activation of high-affinity inhibitory A₁ and facilitatory A(2A) receptors. The therapeutic potential of adenosine-related compounds for controlling intestinal motility and inflammation, prompted us to investigate further the role of low-affinity adenosine receptors, A(2B) and A₃, on electrically-evoked (5 Hz, 200 pulses) [³H]ACh release from myenteric neurons. Immunolocalization studies showed that A(2B) receptors exhibit a pattern of distribution similar to the glial cell marker, GFAP. Regarding A₁ and A₃ receptors, they are mainly distributed to cell bodies of ganglionic myenteric neurons, whereas A(2A) receptors are localized predominantly on cholinergic nerve terminals. Using selective antagonists (DPCPX, ZM241385 and MRS1191), data indicate that modulation of evoked [³H]ACh release is balanced through tonic activation of inhibitory (A₁) and facilitatory (A(2A) and A₃) receptors by endogenous adenosine. The selective A(2B) receptor antagonist, PSB603, alone was devoid of effect and failed to modify the inhibitory effect of NECA. The A₃ receptor agonist, 2-Cl-IB MECA (1-10 nM), concentration-dependently increased the release of [³H]ACh. The effect of 2-Cl-IB MECA was attenuated by MRS1191 and by ZM241385, which selectively block respectively A₃ and A(2A) receptors. In contrast to 2-Cl-IB MECA, activation of A(2A) receptors with CGS21680C attenuated nicotinic facilitation of ACh release induced by focal depolarization of myenteric nerve terminals in the presence of tetrodotoxin. Tandem localization of excitatory A₃ and A(2A) receptors along myenteric neurons explains why stimulation of A₃ receptors (with 2-Cl-IB MECA) on nerve cell bodies acts cooperatively with prejunctional facilitatory A(2A) receptors to up-regulate acetylcholine release. The results presented herein consolidate and expand the current understanding of adenosine receptor distribution and function in the myenteric plexus of the rat ileum, and should be taken into consideration for data interpretation regarding the pathophysiological implications of adenosine on intestinal motility disorders.
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Affiliation(s)
- Cátia Vieira
- Laboratório de Farmacologia e Neurobiologia/UMIB, Instituto de Ciências Biomédicas Abel Salazar-Universidade do Porto-ICBAS-UP, Portugal
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Ren T, Grants I, Alhaj M, McKiernan M, Jacobson M, Hassanain HH, Frankel W, Wunderlich J, Christofi FL. Impact of disrupting adenosine A₃ receptors (A₃⁻/⁻ AR) on colonic motility or progression of colitis in the mouse. Inflamm Bowel Dis 2011; 17:1698-713. [PMID: 21744424 PMCID: PMC3116114 DOI: 10.1002/ibd.21553] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 10/01/2010] [Indexed: 01/24/2023]
Abstract
BACKGROUND Pharmacological studies suggest that adenosine A₃AR influences motility and colitis. Functional A₃⁻/⁻AR knockout mice were used to prove whether A₃AR activation is involved in modulating either motility or colitis. METHODS A₃AR was probed by polymerase chain reaction (PCR) genotyping, Western blot, and immunochemistry. Motility was assessed in vivo by artificial bead-expulsion, stool-frequency, and FITC-dextran transit. Colitis was induced with dextran sodium sulfate (DSS) in A₃⁻/⁻AR or wildtype (WT) age- and sex-matched controls. Progression of colitis was evaluated by histopathology, changes in myeloperoxidase (MPO), colon length, CD4(+) -cells, weight-loss, diarrhea, and the guaiac test. RESULTS Goat anti-hu-A₃ antiserum identified a 66 kDa immunogenic band in colon. A₃AR-immunoreactivity is expressed in SYN(+) -nerve varicosities, s-100(+) -glia, and crypt cells, but not 5-HT(+) (EC), CD4(+) (T), tryptase(+) (MC), or muscle cells. A₃AR immunoreactivity in myenteric ganglia of distal colon >> proximal colon by a ratio of 2:1. Intestinal transit and bead expulsion were accelerated in A₃⁻/⁻AR mice compared to WT; stool retention was lower by 40%-60% and stool frequency by 67%. DSS downregulated A₃AR in epithelia. DSS histopathology scores indicated less mucosal damage in AA₃⁻/⁻AR mice than WT. A₃⁻/⁻AR phenotype protected against DSS-induced weight loss, neutrophil (MPO), or CD4(+) -T cell infiltration, colon shortening, change in splenic weight, diarrhea, or occult-fecal blood. CONCLUSIONS Functional disruption of A₃AR in A₃⁻/⁻AR mice alters intestinal motility. We postulate that ongoing release of adenosine and activation of presynaptic-inhibitory A₃AR can slow down transit and inhibit the defecation reflex. A₃AR may be involved in gliotransmission. In separate studies, A₃⁻/⁻AR protects against DSS colitis, consistent with a novel hypothesis that A₃AR activation contributes to development of colitis.
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Affiliation(s)
- Tianhua Ren
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210
| | - Iveta Grants
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210
| | - Mazin Alhaj
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210
| | - Matt McKiernan
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210
| | | | - Hamdy H. Hassanain
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210
| | - Wendy Frankel
- The Ohio State University, Dept of Pathology, Columbus, Ohio, 43210
| | | | - Fievos L. Christofi
- The Ohio State University, Dept of Anesthesiology, Columbus, Ohio, 43210,Correspondence to: Fievos L. Christofi, Ph.D., Professor and Vice Chair of Research, Department of Anesthesiology, Professor of Physiology & Cell Biology, College of Medicine and Public Health, The Ohio State University, 226 Tzagournis Medical Research Facility, 420 West 12 Avenue, Columbus, OH, U.S.A. 43210, Phone: 614-688-3802, Fax: 614-688-4894,
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Novak I. Purinergic signalling in epithelial ion transport: regulation of secretion and absorption. Acta Physiol (Oxf) 2011; 202:501-22. [PMID: 21073662 DOI: 10.1111/j.1748-1716.2010.02225.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intracellular ATP, the energy source for many reactions, is crucial for the activity of plasma membrane pumps and, thus, for the maintenance of transmembrane ion gradients. Nevertheless, ATP and other nucleotides/nucleosides are also extracellular molecules that regulate diverse cellular functions, including ion transport. In this review, I will first introduce the main components of the extracellular ATP signalling, which have become known as the purinergic signalling system. With more than 50 components or processes, just at cell membranes, it ranks as one of the most versatile signalling systems. This multitude of system components may enable differentiated regulation of diverse epithelial functions. As epithelia probably face the widest variety of potential ATP-releasing stimuli, a special attention will be given to stimuli and mechanisms of ATP release with a focus on exocytosis. Subsequently, I will consider membrane transport of major ions (Cl(-) , HCO(3)(-) , K(+) and Na(+) ) and integrate possible regulatory functions of P2Y2, P2Y4, P2Y6, P2Y11, P2X4, P2X7 and adenosine receptors in some selected epithelia at the cellular level. Some purinergic receptors have noteworthy roles. For example, many studies to date indicate that the P2Y2 receptor is one common denominator in regulating ion channels on both the luminal and basolateral membranes of both secretory and absorptive epithelia. In exocrine glands though, P2X4 and P2X7 receptors act as cation channels and, possibly, as co-regulators of secretion. On an organ level, both receptor types can exert physiological functions and together with other partners in the purinergic signalling, integrated models for epithelial secretion and absorption are emerging.
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Affiliation(s)
- I Novak
- Department of Biology, August Krogh Building, University of Copenhagen, Denmark.
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Hsieh YD, Chi CC, Chou CT, Cheng JS, Kuo CC, Liang WZ, Lin KL, Tseng LL, Jan CR. Investigation of carvedilol-evoked Ca²+ movement and death in human oral cancer cells. J Recept Signal Transduct Res 2011; 31:220-8. [PMID: 21619449 DOI: 10.3109/10799893.2011.577785] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The effect of carvedilol on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) in OC2 human oral cancer cells is unknown. This study examined if carvedilol altered basal [Ca²⁺](i) levels in suspended OC2 cells by using fura-2 as a Ca²⁺-sensitive fluorescent probe. Carvedilol at concentrations between 10 and 40 µM increased [Ca²⁺](i) in a concentration-dependent fashion. The Ca²⁺ signal was decreased by 50% by removing extracellular Ca²⁺. Carvedilol-induced Ca²⁺ entry was not affected by the store-operated Ca²⁺ channel blockers nifedipine, econazole, and SK&F96365, but was enhanced by activation or inhibition of protein kinase C. In Ca²⁺-free medium, incubation with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin did not change carvedilol-induced [Ca²⁺](i) rise; conversely, incubation with carvedilol did not reduce thapsigargin-induced Ca²⁺ release. Pretreatment with the mitochondrial uncoupler carbonylcyanide m-chlorophenylhydrazone (CCCP) inhibited carvedilol-induced [Ca²⁺](i) release. Inhibition of phospholipase C with U73122 did not alter carvedilol-induced [Ca²⁺](i) rise. Carvedilol at 5-50 µM induced cell death in a concentration-dependent manner. The death was not reversed when cytosolic Ca²⁺ was chelated with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM). Annexin V/propidium iodide staining assay suggests that apoptosis played a role in the death. Collectively, in OC2 cells, carvedilol induced [Ca²⁺](i) rise by causing phospholipase C-independent Ca²⁺ release from mitochondria and non-endoplasmic reticulum stores, and Ca²⁺ influx via protein kinase C-regulated channels. Carvedilol (up to 50 μM) induced cell death in a Ca²⁺-independent manner that involved apoptosis.
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Affiliation(s)
- Yao-Dung Hsieh
- Department of Dentistry, Kaohsiung Veterans General Hospital, Taiwan
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Lavoie EG, Gulbransen BD, Martín-Satué M, Aliagas E, Sharkey KA, Sévigny J. Ectonucleotidases in the digestive system: focus on NTPDase3 localization. Am J Physiol Gastrointest Liver Physiol 2011; 300:G608-20. [PMID: 21233276 DOI: 10.1152/ajpgi.00207.2010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Extracellular nucleotides and adenosine are biologically active molecules that bind members of the P2 and P1 receptor families, respectively. In the digestive system, these receptors modulate various functions, including salivary, gastric, and intestinal epithelial secretion and enteric neurotransmission. The availability of P1 and P2 ligands is modulated by ectonucleotidases, enzymes that hydrolyze extracellular nucleotides into nucleosides. Nucleoside triphosphate diphosphohydrolases (NTPDases) and ecto-5'-nucleotidase are the dominant ectonucleotidases at physiological pH. While there is some information about the localization of ecto-5'-nucleotidase and NTPDase1 and -2, the distribution of NTPDase3 in the digestive system is unknown. We examined the localization of these ectonucleotidases, with a focus on NTPDase3, in the gastrointestinal tract and salivary glands. NTPDase1, -2, and -3 are responsible for ecto-ATPase activity in these tissues. Semiquantitative RT-PCR, immunohistochemistry, and in situ enzyme activity revealed the presence of NTPDase3 in some epithelial cells in serous acini of salivary glands and mucous acini and duct cells of sublingual salivary glands, in cells from the stratified esophageal and forestomach epithelia, and in some enteroendocrine cells of the gastric antrum. Interestingly, NTPDase2 and ecto-5'-nucleotidase are coexpressed with NTPDase3 in salivary gland cells and stratified epithelia. In the colon, neurons express NTPDase3 and glial cells express NTPDase2. Ca(2+) imaging experiments demonstrate that NTPDases regulate P2 receptor ligand availability in the enteric nervous system. In summary, the specific localization of NTPDase3 in the digestive system suggests functional roles of the enzyme, in association with NTPDase2 and ecto-5'-nucleotidase, in epithelial functions such as secretion and in enteric neurotransmission.
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Affiliation(s)
- Elise G Lavoie
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, QC, Canada
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ATP induces contraction mediated by the P2Y(2) receptor in rat intestinal subepithelial myofibroblasts. Eur J Pharmacol 2011; 657:152-8. [PMID: 21296070 DOI: 10.1016/j.ejphar.2011.01.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 01/21/2011] [Accepted: 01/25/2011] [Indexed: 01/29/2023]
Abstract
Intestinal subepithelial myofibroblasts (IMFs) exist just under the epithelial membrane directly facing the mucosal microvascular capillary surface distributed in the lamina propria. In the gastrointestinal tract, ATP is released from epithelial and endothelial cells in response to mechanical stimuli. Although it has been reported that mechanical stimuli evoke synchronized Ca(2+) waves in cultured IMFs, the contractile responses by ATP stimulation have not been examined. The aim of this study was to clarify the mechanism of the contraction of IMFs in response to ATP. ATP (1-30μM) induced contraction in a concentration-dependent manner. These contractions were inhibited by LaCl(3) (100-300μM) and by Ca(2+)-free solution (0.5mM EGTA). Fura-2/Ca(2+) signals indicated that ATP (1-10μM) elicited transient increases in intracellular Ca(2+) concentration ([Ca(2+)](i)). In addition, αβ-methylene-ATP (10, 30 and 300μM), a broad spectrum P2X agonist at a concentration higher than 100μM, induced neither contraction nor [Ca(2+)](i) rise. UTP (1-30μM), a selective P2Y(2) and P2Y(4) agonist in rodent, induced concentration-dependent contractions and [Ca(2+)](i) increases, whereas ADP and UDP (10μM) did not induce contractions. Pretreatment with suramin (30-100μM), a relatively selective P2Y(2) antagonist, strongly inhibited ATP- and UTP-induced contractions and [Ca(2+)](i) increases. However, pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS: 10-30μM), a receptor antagonist for several P2X and P2Y but less effective to P2Y(2) receptor, failed to inhibit ATP- and UTP-induced contractions and [Ca(2+)](i) increases. By RT-PCR, mRNA expressions of the P2Y(1) and P2Y(2) receptors, but not P2Y(4) or P2Y(6), were detected in IMFs. These results suggest that ATP induces [Ca(2+)](i)-dependent contraction in IMFs, which is mediated through the P2Y(2) receptor.
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