title: Bioelectric characterization of epithelia from neonatal CFTR knockout ferrets.
abstract: Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4'-diisothiocyano-2,2'-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin-stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)-inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin-inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport.
authors.affiliation: Departments of 1 Anatomy & Cell Biology.
authors.forename: John T
authors.initials: JT
authors.lastname: Fisher
authors.forename: Scott R
authors.initials: SR
authors.lastname: Tyler
authors.forename: Yulong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Lee
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liu
authors.forename: Xingshen
authors.initials: X
authors.lastname: Sun
authors.forename: Hongshu
authors.initials: H
authors.lastname: Sui
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.forename: Meihui
authors.initials: M
authors.lastname: Luo
authors.forename: Weiliang
authors.initials: W
authors.lastname: Xie
authors.forename: Yaling
authors.initials: Y
authors.lastname: Yi
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.forename: Yi
authors.initials: Y
authors.lastname: Song
authors.forename: Nicholas
authors.initials: N
authors.lastname: Keiser
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Hugo R
authors.initials: HR
authors.lastname: de Jonge
authors.forename: John F
authors.initials: JF
authors.lastname: Engelhardt
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D000831:Animals, Newborn; D002712:Chlorides / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D003550:Cystic Fibrosis / Q000235:genetics / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000172:deficiency* / Q000187:drug effects / Q000235:genetics; D004195:Disease Models, Animal; D017097:Electric Impedance; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D005289:Ferrets / Q000235:genetics*; D005704:Gallbladder / Q000187:drug effects / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism*; D055786:Gene Knockout Techniques; D005838:Genotype; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D017136:Ion Transport; D008564:Membrane Potentials; D049990:Membrane Transport Modulators / Q000494:pharmacology; D010641:Phenotype; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
chemical_list: D002712:Chlorides; D020536:Enzyme Activators; D049990:Membrane Transport Modulators; D010726:Phosphodiesterase Inhibitors; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D012964:Sodium; D000242:Cyclic AMP; D000262:Adenylyl Cyclases