Referenced in: none

Automatically associated channels: Kir6.2

Title: Loss of anion transport without increased sodium absorption characterizes newborn porcine cystic fibrosis airway epithelia.

Authors: Jeng-Haur Chen, David A Stoltz, Philip H Karp, Sarah E Ernst, Alejandro A Pezzulo, Thomas O Moninger, Michael V Rector, Leah R Reznikov, Janice L Launspach, Kathryn Chaloner, Joseph Zabner, Michael J Welsh

Journal, date & volume: Cell, 2010 Dec 10 , 143, 911-23

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/21145458

Abstract
Defective transepithelial electrolyte transport is thought to initiate cystic fibrosis (CF) lung disease. Yet, how loss of CFTR affects electrolyte transport remains uncertain. CFTR⁻(/)⁻ pigs spontaneously develop lung disease resembling human CF. At birth, their airways exhibit a bacterial host defense defect, but are not inflamed. Therefore, we studied ion transport in newborn nasal and tracheal/bronchial epithelia in tissues, cultures, and in vivo. CFTR⁻(/)⁻ epithelia showed markedly reduced Cl⁻ and HCO₃⁻ transport. However, in contrast to a widely held view, lack of CFTR did not increase transepithelial Na(+) or liquid absorption or reduce periciliary liquid depth. Like human CF, CFTR⁻(/)⁻ pigs showed increased amiloride-sensitive voltage and current, but lack of apical Cl⁻ conductance caused the change, not increased Na(+) transport. These results indicate that CFTR provides the predominant transcellular pathway for Cl⁻ and HCO₃⁻ in porcine airway epithelia, and reduced anion permeability may initiate CF airway disease.