CFTR is involved in airway epithelial cell migration.

Abstract

Migration of Calu‐3 cells was investigated by measuring changes in impedance as cells moved onto an electrode imbedded within a tissue culture chamber slide. Experiments were performed in serum‐free, HCO3 buffered MEM maintained in a humidified 5% CO2 incubator at 37 °C. Once cells reached confluence, a circular lesion (250 μm diameter) was produced by electroporation of cells in contact with the electrode. Alternating current (∼1 μA) at high frequency was then continuously applied to measure impedance and monitor migration of cells from the margin into the lesioned area. Under serum free conditions, maximum impedance (∼10 kΩ) was restored after 10 hours. When cells were treated with EGF (5 μg/ml), maximum impedance was restored within 2.5 hours. Inhibition of actin polymerization with cytochalasin D completely inhibited migration. Moreover, pretreatment with EGF (5 μg/ml) and 50 μM CFTRinh–172, delayed restitution by 22 hours compared to EGF treated controls. Additionally, constitutive knockdown (>95%) of CFTR expression using shRNA also delayed recovery by >30 hours compared to cells expressing an altered shCFTR construct containing 4 bp substitutions that prevent targeting of CFTR. The results of these experiments indicate that functional activity of CFTR is necessary for Calu‐3 cell migration and suggests a role for CFTR in epithelial cell restitution.