Phenylquinoxalinone CFTR activator as potential prosecretory therapy for constipation.
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.
Departments of Medicine and Physiology, University of California San Francisco, San Francisco, Calif.
Onur
O
Cil
Departments of Medicine and Physiology, University of California San Francisco, San Francisco, Calif.
Puay-Wah
PW
Phuan
Department of Chemistry, University of California, Davis, Calif.
Jung-Ho
JH
Son
Department of Chemistry, University of California, Davis, Calif.
Jie S
JS
Zhu
Department of Chemistry, University of California, Davis, Calif.
Colton K
CK
Ku
Department of Chemistry, University of California, Davis, Calif.
Niloufar Akhavan
NA
Tabib
Department of Chemistry, University of California, Davis, Calif.
Andrew P
AP
Teuthorn
Istituto Giannina Gaslini, Genova, Italy.
Loretta
L
Ferrera
Departments of Physiology and Medicine, Gastroenterology Division, Johns Hopkins University School of Medicine, Baltimore, Md.
Nicholas C
NC
Zachos
Departments of Physiology and Medicine, Gastroenterology Division, Johns Hopkins University School of Medicine, Baltimore, Md.
Ruxian
R
Lin
Istituto Giannina Gaslini, Genova, Italy.
Luis J V
LJV
Galietta
Departments of Physiology and Medicine, Gastroenterology Division, Johns Hopkins University School of Medicine, Baltimore, Md.
Mark
M
Donowitz
Department of Chemistry, University of California, Davis, Calif.
Mark J
MJ
Kurth
Departments of Medicine and Physiology, University of California San Francisco, San Francisco, Calif. Electronic address: Alan.Verkman@ucsf.edu.
Alan S
AS
Verkman
D000208:Acute Disease; D000818:Animals; D001826:Body Fluids / Q000187:drug effects / Q000378:metabolism*; D002460:Cell Line; D002908:Chronic Disease; D003248:Constipation / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D004195:Disease Models, Animal; D004386:Duodenum / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D006801:Humans; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism; D000068238:Lubiprostone / Q000494:pharmacology; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D011810:Quinoxalines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D012601:Scopolamine / Q000494:pharmacology; D013329:Structure-Activity Relationship
D010455:Peptides; D011810:Quinoxalines; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000068238:Lubiprostone; D012601:Scopolamine; C523483:linaclotide