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A Potent Inhibitor of the Cystic Fibrosis Transmembrane Conductance Regulator Blocks Disease and Morbidity Due to Toxigenic Vibrio cholerae. Toxins (Basel) 2022; 14:toxins14030225. [PMID: 35324722 PMCID: PMC8948642 DOI: 10.3390/toxins14030225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 01/24/2023] Open
Abstract
Vibrio cholerae uses cholera toxin (CT) to cause cholera, a severe diarrheal disease in humans that can lead to death within hours of the onset of symptoms. The catalytic activity of CT in target epithelial cells increases cellular levels of 3',5'-cyclic AMP (cAMP), leading to the activation of the cystic fibrosis transmembrane conductance regulator (CFTR), an apical ion channel that transports chloride out of epithelial cells, resulting in an electrolyte imbalance in the intestinal lumen and massive water loss. Here we report that when administered perorally, benzopyrimido-pyrrolo-oxazinedione, (R)-BPO-27), a potent small molecule inhibitor of CFTR, blocked disease symptoms in a mouse model for acute diarrhea caused by toxigenic V. cholerae. We show that both (R)-BPO-27 and its racemic mixture, (R/S)-BPO-27, are able to protect mice from CT-dependent diarrheal disease and death. Furthermore, we show that, consistent with the ability of the compound to block the secretory diarrhea induced by CT, BPO-27 has a measurable effect on suppressing the gut replication and survival of V. cholerae, including a 2010 isolate from Haiti that is representative of the most predominant 'variant strains' that are causing epidemic and pandemic cholera worldwide. Our results suggest that BPO-27 should advance to human Phase I studies that could further address its safety and efficacy as therapeutic or preventative drug intervention for diarrheal syndromes, including cholera, that are mediated by CFTR channel activation.
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Abstract
Chloride transport across cell membranes is broadly involved in epithelial fluid transport, cell volume and pH regulation, muscle contraction, membrane excitability, and organellar acidification. The human genome encodes at least 53 chloride-transporting proteins with expression in cell plasma or intracellular membranes, which include chloride channels, exchangers, and cotransporters, some having broad anion specificity. Loss-of-function mutations in chloride transporters cause a wide variety of human diseases, including cystic fibrosis, secretory diarrhea, kidney stones, salt-wasting nephropathy, myotonia, osteopetrosis, hearing loss, and goiter. Although impactful advances have been made in the past decade in drug treatment of cystic fibrosis using small molecule modulators of the defective cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel, other chloride channels and solute carrier proteins (SLCs) represent relatively underexplored target classes for drug discovery. New opportunities have emerged for the development of chloride transport modulators as potential therapeutics for secretory diarrheas, constipation, dry eye disorders, kidney stones, polycystic kidney disease, hypertension, and osteoporosis. Approaches to chloride transport-targeted drug discovery are reviewed herein, with focus on chloride channel and exchanger classes in which recent preclinical advances have been made in the identification of small molecule modulators and in proof of concept testing in experimental animal models.
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Affiliation(s)
- Alan S Verkman
- Department of Medicine, University of California, San Francisco, California.,Department of Physiology, University of California, San Francisco, California
| | - Luis J V Galietta
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
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3
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Javadi N, Rezaeian M, Fakhraian H. The conglomerate crystal formation of methoxetamine salts in the presence of some organic achiral anions: a theoretical approach. Supramol Chem 2021. [DOI: 10.1080/10610278.2021.1961259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Nabi Javadi
- Department of Chemistry, Faculty of Science, Imam Hossein University, Tehran, Iran
| | - Mojtaba Rezaeian
- Research Center for Modeling and Computational Science, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hossein Fakhraian
- Department of Chemistry, Faculty of Science, Imam Hossein University, Tehran, Iran
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4
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de Jonge HR, Ardelean MC, Bijvelds MJC, Vergani P. Strategies for cystic fibrosis transmembrane conductance regulator inhibition: from molecular mechanisms to treatment for secretory diarrhoeas. FEBS Lett 2020; 594:4085-4108. [PMID: 33113586 PMCID: PMC7756540 DOI: 10.1002/1873-3468.13971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/22/2020] [Accepted: 10/15/2020] [Indexed: 02/06/2023]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is an unusual ABC transporter. It acts as an anion‐selective channel that drives osmotic fluid transport across many epithelia. In the gut, CFTR is crucial for maintaining fluid and acid‐base homeostasis, and its activity is tightly controlled by multiple neuro‐endocrine factors. However, microbial toxins can disrupt this intricate control mechanism and trigger protracted activation of CFTR. This results in the massive faecal water loss, metabolic acidosis and dehydration that characterize secretory diarrhoeas, a major cause of malnutrition and death of children under 5 years of age. Compounds that inhibit CFTR could improve emergency treatment of diarrhoeal disease. Drawing on recent structural and functional insight, we discuss how existing CFTR inhibitors function at the molecular and cellular level. We compare their mechanisms of action to those of inhibitors of related ABC transporters, revealing some unexpected features of drug action on CFTR. Although challenges remain, especially relating to the practical effectiveness of currently available CFTR inhibitors, we discuss how recent technological advances might help develop therapies to better address this important global health need.
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Affiliation(s)
- Hugo R. de Jonge
- Department of Gastroenterology & HepatologyErasmus University Medical CenterRotterdamThe Netherlands
| | - Maria C. Ardelean
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonUK
- Department of Natural SciencesUniversity College LondonUK
| | - Marcel J. C. Bijvelds
- Department of Gastroenterology & HepatologyErasmus University Medical CenterRotterdamThe Netherlands
| | - Paola Vergani
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonUK
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5
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Duan T, Cil O, Tse CM, Sarker R, Lin R, Donowitz M, Verkman AS. Inhibition of CFTR-mediated intestinal chloride secretion as potential therapy for bile acid diarrhea. FASEB J 2019; 33:10924-10934. [PMID: 31268738 PMCID: PMC6766649 DOI: 10.1096/fj.201901166r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/04/2019] [Indexed: 12/19/2022]
Abstract
Bile acid diarrhea (BAD) is common with ileal resection, Crohn's disease, and diarrhea-predominant irritable bowel syndrome. Here, we demonstrate the efficacy of cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor (R)-benzopyrimido-pyrrolo-oxazine-dione-27 (BPO-27) in reducing bile acid-induced fluid and electrolyte secretion in colon. Short-circuit current measurements in human T84 colonic epithelial cells and planar colonic enteroid cultures showed a robust secretory response following mucosal but not serosal addition of chenodeoxycholic acid (CDCA) or its taurine conjugate, which was fully blocked by CFTR inhibitors, including (R)-BPO-27. (R)-BPO-27 also fully blocked CDCA-induced secretory current in murine colon. CFTR activation by CDCA primarily involved Ca2+ signaling. In closed colonic loops in vivo, luminal CDCA produced a robust secretory response, which was reduced by ∼70% by (R)-BPO-27 or in CFTR-deficient mice. In a rat model of BAD produced by intracolonic infusion of CDCA, (R)-BPO-27 reduced the elevation in stool water content by >55%. These results implicate CFTR activation in the colon as a major prosecretory mechanism of CDCA, a bile acid implicated in BAD, and support the potential therapeutic efficacy of CFTR inhibition in bile acid-associated diarrheas.-Duan, T., Cil, O., Tse, C. M., Sarker, R., Lin, R., Donowitz, M., Verkman, A. S. Inhibition of CFTR-mediated intestinal chloride secretion as potential therapy for bile acid diarrhea.
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Affiliation(s)
- Tianying Duan
- Department of Medicine, University of California–San Francisco, San Francisco, California, USA
- Department of Physiology, University of California–San Francisco, San Francisco, California, USA
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Onur Cil
- Department of Medicine, University of California–San Francisco, San Francisco, California, USA
- Department of Pediatrics, University of California–San Francisco, San Francisco, California, USA
| | - C. Ming Tse
- Gastroenterology Division, Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rafiquel Sarker
- Gastroenterology Division, Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ruxian Lin
- Gastroenterology Division, Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mark Donowitz
- Gastroenterology Division, Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Alan S. Verkman
- Department of Medicine, University of California–San Francisco, San Francisco, California, USA
- Department of Physiology, University of California–San Francisco, San Francisco, California, USA
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Duan T, Cil O, Thiagarajah JR, Verkman AS. Intestinal epithelial potassium channels and CFTR chloride channels activated in ErbB tyrosine kinase inhibitor diarrhea. JCI Insight 2019; 4:126444. [PMID: 30668547 PMCID: PMC6478423 DOI: 10.1172/jci.insight.126444] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/14/2019] [Indexed: 12/11/2022] Open
Abstract
Diarrhea is a major side effect of ErbB receptor tyrosine kinase inhibitors (TKIs) in cancer chemotherapy. Here, we show that the primary mechanism of ErbB TKI diarrhea is activation of basolateral membrane potassium (K+) channels and apical membrane chloride (Cl-) channels in intestinal epithelia and demonstrate the efficacy of channel blockers in a rat model of TKI diarrhea. Short-circuit current in colonic epithelial cells showed that the TKIs gefitinib, lapatinib, and afatinib do not affect basal secretion but amplify carbachol-stimulated secretion by 2- to 3-fold. Mechanistic studies with the second-generation TKI afatinib showed that the amplifying effect on Cl- secretion was Ca2+ and cAMP independent, was blocked by CF transmembrane conductance regulator (CFTR) and K+ channel inhibitors, and involved EGFR binding and ERK signaling. Afatinib-amplified activation of basolateral K+ and apical Cl- channels was demonstrated by selective membrane permeabilization, ion substitution, and channel inhibitors. Rats that were administered afatinib orally at 60 mg/kg/day developed diarrhea with increased stool water from approximately 60% to greater than 80%, which was reduced by up to 75% by the K+ channel inhibitors clotrimazole or senicapoc or the CFTR inhibitor (R)-BPO-27. These results indicate a mechanism for TKI diarrhea involving K+ and Cl- channel activation and support the therapeutic efficacy of channel inhibitors.
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Affiliation(s)
- Tianying Duan
- Departments of Medicine and Physiology, UCSF, San Francisco, California, USA.,Department of Gastroenterology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Onur Cil
- Departments of Medicine and Physiology, UCSF, San Francisco, California, USA.,Department of Pediatrics, UCSF, San Francisco, California, USA
| | - Jay R Thiagarajah
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan S Verkman
- Departments of Medicine and Physiology, UCSF, San Francisco, California, USA
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Hwang TC, Yeh JT, Zhang J, Yu YC, Yeh HI, Destefano S. Structural mechanisms of CFTR function and dysfunction. J Gen Physiol 2018; 150:539-570. [PMID: 29581173 PMCID: PMC5881446 DOI: 10.1085/jgp.201711946] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/05/2018] [Indexed: 12/18/2022] Open
Abstract
Hwang et al. integrate new structural insights with prior functional studies to reveal the functional anatomy of CFTR chloride channels. Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel plays a critical role in regulating transepithelial movement of water and electrolyte in exocrine tissues. Malfunction of the channel because of mutations of the cftr gene results in CF, the most prevalent lethal genetic disease among Caucasians. Recently, the publication of atomic structures of CFTR in two distinct conformations provides, for the first time, a clear overview of the protein. However, given the highly dynamic nature of the interactions among CFTR’s various domains, better understanding of the functional significance of these structures requires an integration of these new structural insights with previously established biochemical/biophysical studies, which is the goal of this review.
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Affiliation(s)
- Tzyh-Chang Hwang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO .,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO.,Department of Biological Engineering, University of Missouri, Columbia, MO
| | - Jiunn-Tyng Yeh
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
| | - Jingyao Zhang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO.,Department of Biological Engineering, University of Missouri, Columbia, MO
| | - Ying-Chun Yu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| | - Han-I Yeh
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| | - Samantha Destefano
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
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Cil O, Phuan PW, Gillespie AM, Lee S, Tradtrantip L, Yin J, Tse M, Zachos NC, Lin R, Donowitz M, Verkman AS. Benzopyrimido-pyrrolo-oxazine-dione CFTR inhibitor (R)-BPO-27 for antisecretory therapy of diarrheas caused by bacterial enterotoxins. FASEB J 2016; 31:751-760. [PMID: 27871064 DOI: 10.1096/fj.201600891r] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 10/24/2016] [Indexed: 12/15/2022]
Abstract
Secretory diarrheas caused by bacterial enterotoxins, including cholera and traveler's diarrhea, remain a major global health problem. Inappropriate activation of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel occurs in these diarrheas. We previously reported that the benzopyrimido-pyrrolo-oxazinedione (R)-BPO-27 inhibits CFTR chloride conductance with low-nanomolar potency. Here, we demonstrate using experimental mouse models and human enterocyte cultures the potential utility of (R)-BPO-27 for treatment of secretory diarrheas caused by cholera and Escherichia coli enterotoxins. (R)-BPO-27 fully blocked CFTR chloride conductance in epithelial cell cultures and intestine after cAMP agonists, cholera toxin, or heat-stable enterotoxin of E. coli (STa toxin), with IC50 down to ∼5 nM. (R)-BPO-27 prevented cholera toxin and STa toxin-induced fluid accumulation in small intestinal loops, with IC50 down to 0.1 mg/kg. (R)-BPO-27 did not impair intestinal fluid absorption or inhibit other major intestinal transporters. Pharmacokinetics in mice showed >90% oral bioavailability with sustained therapeutic serum levels for >4 h without the significant toxicity seen with 7-d administration at 5 mg/kg/d. As evidence to support efficacy in human diarrheas, (R)-BPO-27 blocked fluid secretion in primary cultures of enteroids from human small intestine and anion current in enteroid monolayers. These studies support the potential utility of (R)-BPO-27 for therapy of CFTR-mediated secretory diarrheas.-Cil, O., Phuan, P.-W., Gillespie, A. M., Lee, S., Tradtrantip, L., Yin, J., Tse, M., Zachos, N. C., Lin, R., Donowitz, M., Verkman, A. S. Benzopyrimido-pyrrolo-oxazine-dione CFTR inhibitor (R)-BPO-27 for antisecretory therapy of diarrheas caused by bacterial enterotoxins.
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Affiliation(s)
- Onur Cil
- Department of Medicine, University of California San Francisco, San Francisco, California, USA.,Department of Physiology, University of California San Francisco, San Francisco, California, USA
| | - Puay-Wah Phuan
- Department of Medicine, University of California San Francisco, San Francisco, California, USA.,Department of Physiology, University of California San Francisco, San Francisco, California, USA
| | - Anne Marie Gillespie
- Department of Medicine, University of California San Francisco, San Francisco, California, USA.,Department of Physiology, University of California San Francisco, San Francisco, California, USA
| | - Sujin Lee
- Department of Medicine, University of California San Francisco, San Francisco, California, USA.,Department of Physiology, University of California San Francisco, San Francisco, California, USA
| | - Lukmanee Tradtrantip
- Department of Medicine, University of California San Francisco, San Francisco, California, USA.,Department of Physiology, University of California San Francisco, San Francisco, California, USA
| | - Jianyi Yin
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and.,Gastroenterology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ming Tse
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and.,Gastroenterology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nicholas C Zachos
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and.,Gastroenterology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ruxian Lin
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and.,Gastroenterology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mark Donowitz
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; and.,Gastroenterology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Alan S Verkman
- Department of Medicine, University of California San Francisco, San Francisco, California, USA; .,Department of Physiology, University of California San Francisco, San Francisco, California, USA
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9
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Kim Y, Anderson MO, Park J, Lee MG, Namkung W, Verkman AS. Benzopyrimido-pyrrolo-oxazine-dione (R)-BPO-27 Inhibits CFTR Chloride Channel Gating by Competition with ATP. Mol Pharmacol 2015; 88:689-96. [PMID: 26174774 DOI: 10.1124/mol.115.098368] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/13/2015] [Indexed: 12/16/2022] Open
Abstract
We previously reported that benzopyrimido-pyrrolo-oxazinedione BPO-27 [6-(5-bromofuran-2-yl)-7,9-dimethyl-8,10-dioxo-11-phenyl-7,8,9,10-tetrahydro-6H-benzo[b]pyrimido [4',5':3,4]pyrrolo [1,2-d][1,4]oxazine-2-carboxylic acid] inhibits the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel with low nanomolar potency and reduces cystogenesis in a model of polycystic kidney disease. We used computational chemistry and patch-clamp to show that enantiomerically pure (R)-BPO-27 inhibits CFTR by competition with ATP, whereas (S)-BPO-27 is inactive. Docking computations using a homology model of CFTR structure suggested that (R)-BPO-27 binds near the canonical ATP binding site, and these findings were supported by molecular dynamics simulations showing a lower binding energy for the (R) versus (S) stereoisomers. Three additional lower-potency BPO-27 analogs were modeled in a similar fashion, with the binding energies predicted in the correct order. Whole-cell patch-clamp studies showed linear CFTR currents with a voltage-independent (R)-BPO-27 block mechanism. Single-channel recordings in inside-out patches showed reduced CFTR channel open probability and increased channel closed time by (R)-BPO-27 without altered unitary channel conductance. At a concentration of (R)-BPO-27 that inhibited CFTR chloride current by ∼50%, the EC50 for ATP activation of CFTR increased from 0.27 to 1.77 mM but was not changed by CFTRinh-172 [4-[[4-oxo-2-thioxo-3-[3-trifluoromethyl)phenyl]-5-thiazolidinylidene]methyl]benzoic acid], a thiazolidinone CFTR inhibitor that acts at a site distinct from the ATP binding site. Our results suggest that (R)-BPO-27 inhibition of CFTR involves competition with ATP.
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Affiliation(s)
- Yonjung Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
| | - Marc O Anderson
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
| | - Jinhong Park
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
| | - Min Goo Lee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
| | - Wan Namkung
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
| | - A S Verkman
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea (Y.K., M.G.L.); Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California (M.O.A.); College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea (J.P., W.N.); and Departments of Medicine and Physiology, University of California, San Francisco, California (A.S.V.)
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Chloride channel-targeted therapy for secretory diarrheas. Curr Opin Pharmacol 2013; 13:888-94. [PMID: 23992767 DOI: 10.1016/j.coph.2013.08.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/30/2013] [Accepted: 08/01/2013] [Indexed: 12/18/2022]
Abstract
Secretory diarrheas caused by bacterial and viral enterotoxins remain a significant cause of morbidity and mortality. Enterocyte Cl(-) channels represent an attractive class of targets for diarrhea therapy, as they are the final, rate-limiting step in enterotoxin-induced fluid secretion in the intestine. Activation of cyclic nucleotide and/or Ca(2+) signaling pathways in secretory diarrheas increases the conductance of Cl(-) channels at the enterocyte luminal membrane, which include the cystic fibrosis transmembrane conductance regulator (CFTR) and Ca(2+)-activated Cl(-) channels (CaCCs). High-throughput screens have yielded several chemical classes of small molecule CFTR and CaCC inhibitors that show efficacy in animal models of diarrheas. Natural-product diarrhea remedies with Cl(-) channel inhibition activity have also been identified, with one product recently receiving FDA approval for HIV-associated diarrhea.
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