Dataset Information

Phenylquinoxalinone CFTR activator as potential prosecretory therapy for constipation.

ABSTRACT: Constipation is a common condition for which current treatments can have limited efficacy. By high-throughput screening, we recently identified a phenylquinoxalinone activator of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel that stimulated intestinal fluid secretion and normalized stool output in a mouse model of opioid-induced constipation. Here, we report phenylquinoxalinone structure-activity analysis, mechanism of action, animal efficacy data in acute and chronic models of constipation, and functional data in ex vivo primary cultured human enterocytes. Structure-activity analysis was done on 175 phenylquinoxalinone analogs, including 15 synthesized compounds. The most potent compound, CFTRact-J027, activated CFTR with EC50 ? 200 nM, with patch-clamp analysis showing a linear CFTR current-voltage relationship with direct CFTR activation. CFTRact-J027 corrected reduced stool output and hydration in a mouse model of acute constipation produced by scopolamine and in a chronically constipated mouse strain (C3H/HeJ). Direct comparison with the approved prosecretory drugs lubiprostone and linaclotide showed substantially greater intestinal fluid secretion with CFTRact-J027, as well as greater efficacy in a constipation model. As evidence to support efficacy in human constipation, CFTRact-J027 increased transepithelial fluid transport in enteroids generated from normal human small intestine. Also, CFTRact-J027 was rapidly metabolized in vitro in human hepatic microsomes, suggesting minimal systemic exposure upon oral administration. These data establish structure-activity and mechanistic data for phenylquinoxalinone CFTR activators, and support their potential efficacy in human constipation.

SUBMITTER: Cil O

PROVIDER: S-EPMC5453637 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Phenylquinoxalinone CFTR activator as potential prosecretory therapy for constipation.

Cil Onur O Phuan Puay-Wah PW Son Jung-Ho JH Zhu Jie S JS Ku Colton K CK Tabib Niloufar Akhavan NA Teuthorn Andrew P AP Ferrera Loretta L Zachos Nicholas C NC Lin Ruxian R Galietta Luis J V LJV Donowitz Mark M Kurth Mark J MJ Verkman Alan S AS

Translational research : the journal of laboratory and clinical medicine 20161015

Constipation is a common condition for which current treatments can have limited efficacy. By high-throughput screening, we recently identified a phenylquinoxalinone activator of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel that stimulated intestinal fluid secretion and normalized stool output in a mouse model of opioid-induced constipation. Here, we report phenylquinoxalinone structure-activity analysis, mechanism of action, animal efficacy data in acute and c ...[more]

PMID: 27815136

Similar Datasets

Project description:Loss of prosecretory Cl- channel CFTR activity is considered as the key cause of gastrointestinal disorders in cystic fibrosis including constipation and meconium ileus. Clc-2 is proposed as an alternative Cl- channel in intestinal epithelia that can compensate for CFTR loss-of-function. Lubiprostone is an FDA-approved drug with Clc-2 activation as its presumed mechanism of action. However, relative contribution of Clc-2 in intestinal Cl- secretion and the mechanism of action of lubiprostone remain controversial due to lack of selective Clc-2 inhibitors. Using recently identified selective Clc-2 inhibitor AK-42, we characterized the roles of Clc-2 in Cl- secretion in human intestinal epithelial T84 cells. Clc-2 inhibitor AK-42 had minimal (15%) inhibitory effect on secretory short-circuit current (Isc) induced by cAMP agonists, where subsequently applied CFTR inhibitor (CFTRinh-172) caused 2-3 fold greater inhibition. Similarly, AK-42 inhibited lubiprostone-induced secretory Isc by 20%, whereas CFTRinh-172 caused 2-3 fold greater inhibition. In addition to increasing CFTR and Clc-2-mediated apical Cl- conductance, lubiprostone increased basolateral membrane K+ conductance, which was completely reversed by cAMP-activated K+ channel inhibitor BaCl2 All components of lubiprostone-induced secretion (Clc-2, CFTR and K+ channels) were inhibited by ~65% with the extracellular Ca2+-sensing receptor (CaSR) activator cinacalcet that stimulates cAMP hydrolysis. Lastly, EP4 prostaglandin receptor inhibitor GW627368 pretreatment inhibited lubiprostone-induced secretion by 40% without any effect on forskolin response. Our findings suggest that Clc-2 has minor role in cAMP-induced intestinal Cl- secretion; and lubiprostone is not a selective Clc-2 activator, but general activator of cAMP-gated ion channels in human intestinal epithelial cells. Significance Statement Cl- channel Clc-2 activation is the proposed mechanism of action of the FDA-approved constipation drug lubiprostone. Using first-in-class selective Clc-2 inhibitor AK-42, we showed that Clc-2 has minor contribution in intestinal Cl- secretion induced by lubiprostone and cAMP agonists. We also found that lubiprostone is a general activator of cAMP-gated ion channels in human intestinal epithelial cells (via EP4 receptors). Our findings clarify the roles of Clc-2 in intestinal Cl- secretion and elucidate the mechanism of action of approved-drug lubiprostone.

Project description:IntroductionTo inform the patient-centered discussion regarding comparative outcomes with irritable bowel syndrome/chronic idiopathic constipation pharmacotherapy, we evaluated reasons and timing of discontinuation of FDA-approved pharmacotherapy for irritable bowel syndrome and chronic idiopathic constipation in a large observational real-world cohort.MethodsWe identified patients initiating lubiprostone or linaclotide within the University of Michigan Electronic Medical Record (2012-2016). Medication start and stop dates were determined in manual chart review including detailed review of all documentation including office notes and telephone encounters. A Cox model was constructed to predict the hazard of discontinuation.ResultsOn multivariate analysis of 1,612 patients, linaclotide users had a lower risk of discontinuing therapy than lubiprostone users for any reason (hazard ratio [HR] = 0.6, 95% confidence interval [CI] 0.5-0.8). At 3 and 12 months, the overall discontinuation rates were 23% and 43% for lubiprostone compared with 14% and 24% for linaclotide. Over the first year of therapy, more than half of discontinuations due to intolerance occurred in the first 3 months for both drugs. Linaclotide users were more likely to discontinue due to intolerance (HR = 1.6 [95% CI, 1.2-2.3]) but less likely to discontinue due to insufficient efficacy of therapy (HR = 0.5 [95% CI, 0.4-0.8]). IBS diagnosis increased the hazard of discontinuation of lubiprostone relative to linactolide (HR = 1.4, 95% CI, 1.1-1.6). Loss of prescription drug coverage remained a common reason for discontinuation over the first year of therapy.DiscussionIndividuals appear more likely to discontinue lubiprostone than linaclotide overall, but more likely to discontinue linaclotide compared with lubiprostone due to intolerance (mostly diarrhea). Most discontinuations due to intolerance occur in the first 3 months. These results may be useful in individualized treatment selection and enhancing patient knowledge regarding long-term outcomes.

Dataset Information

Phenylquinoxalinone CFTR activator as potential prosecretory therapy for constipation.

Publications

Phenylquinoxalinone CFTR activator as potential prosecretory therapy for constipation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets