title: Chemical rescue of ΔF508-CFTR in C127 epithelial cells reverses aberrant extracellular pH acidification to wild-type alkalization as monitored by microphysiometry.
abstract: Cystic fibrosis (CF) is caused by mutations in the gene for CFTR, a cAMP-activated anion channel expressed in apical membranes of wet epithelia. Since CFTR is permeable to HCO3(-), and may regulate bicarbonate exchangers, it is not surprising evidence of changes in extracellular pH (pHo) have been found in CF. Previously we have shown that tracking pHo can be used to differentiate cells expressing wild-type CFTR from controls in mouse mammary epithelial (C127) and fibroblast (NIH/3T3) cell lines. In this study we characterized forskolin-stimulated extracellular acidification rates in epithelia where chemical correction of mutant ΔF508-CFTR converted an aberrant response in acidification (10%+ increase) to wild-type (25%+ decrease). Thus treatment with corrector (10% glycerol) and the resulting increased expression of ΔF508-CFTR at the surface was detected by microphysiometry as a significant reversal from acidification to alkalization of pHo. These results suggest that CFTR activation as well as correction can be detected by carefully monitoring pHo and support findings in the field that extracellular pH acidification may impact the function of airway surface liquid in CF.
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States. Electronic address: luckie@msu.edu.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Luckie
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Van Alst
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Marija K
authors.initials: MK
authors.lastname: Massey
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Flood
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Aashish A
authors.initials: AA
authors.lastname: Shah
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Vishal
authors.initials: V
authors.lastname: Malhotra
authors.affiliation: Cystic Fibrosis Research Laboratory, Department of Physiology and Lyman Briggs College, Michigan State University, 2100 Biomedical Sciences Bldg., East Lansing, MI 48824, United States.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Kozel
mesh_terms: D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D003550:Cystic Fibrosis / Q000503:physiopathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D018181:Mice, Inbred CFTR; D041681:NIH 3T3 Cells
chemical_list: D001639:Bicarbonates; C093349:cystic fibrosis transmembrane conductance regulator delta F508; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005576:Colforsin
keywords: Bicarbonate; CFTR; Corrector; Cystic fibrosis; Glycerol; pH