Chloride transporting capability of Calu‐3 epithelia following persistent knockdown of the cystic fibrosis transmembrane conductance regulator, CFTR

• Published in: British journal of pharmacology Vol. 150; no. 8; pp. 1055 - 1065
• Main Authors: MacVinish, L J, Cope, G, Ropenga, A, Cuthbert, A W
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2007; Nature Publishing; Nature Publishing Group
• Subjects: Adenylyl Cyclases - metabolism; Alprostadil - analogs & derivatives; Alprostadil - pharmacology; Biological and medical sciences; Calu‐3 cells; Carbachol - pharmacology; Cell Line; CFTR channel blocker; Chloride Channels - metabolism; Chlorides - metabolism; Colforsin - pharmacology; Cyclic AMP - metabolism; Cystic Fibrosis - metabolism; Cystic fibrosis transmembrane conductance regulator; Cystic Fibrosis Transmembrane Conductance Regulator - deficiency; Cystic Fibrosis Transmembrane Conductance Regulator - drug effects; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - metabolism; Dose-Response Relationship, Drug; Enzyme Activation; Epithelial Cells - drug effects; Epithelial Cells - metabolism; epithelial chloride secretion; Errors of metabolism; Fatty Acids - pharmacology; Genetic Vectors; GlyH‐101; human airway submucosal glands; Humans; Lubiprostone; Lung - cytology; Lung - drug effects; Lung - metabolism; Medical sciences; Membrane Potentials; Metabolic diseases; Miscellaneous hereditary metabolic disorders; Muscarinic Agonists - pharmacology; Pharmacology. Drug treatments; Research Papers; Retroviridae - genetics; RNA Interference; RNA, Small Interfering - genetics; RNA, Small Interfering - metabolism; Time Factors; Human; CFTR channel blocker; GlyH-101; Respiratory disease; Secretion; Calu-3 cells; Metabolic diseases; Cystic fibrosis; Respiratory system; In vitro; epithelial chloride secretion; Genetic disease; Respiratory tract; Chlorides; Lubiprostone; Digestive diseases; Antagonist; Cystic fibrosis transmembrane conductance regulator; human airway submucosal glands; Pancreatic disease; Prostaglandin derivatives
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0707175

Background and purpose: Calu‐3 cells are derived from serous cells of human lung submucosal glands, a prime target for therapy in cystic fibrosis (CF). Calu‐3 cells can be cultured to form epithelia capable of transepithelial transport of chloride. A CF Calu‐3 cell is not available. Experimental approach: A retroviral vector was used to cause persistent down regulation of CFTR using siRNA methodology, in Calu‐3 cells. A Calu‐3 cell line with CFTR content less than 5% of the original line has been established. Epithelia grown using the modified cells have been used in comparative studies of transporting capability. Key results: All aspects of cAMP activated chloride secretion were attenuated in the epithelia with reduced CFTR content. However transporting capability was reduced less than the CFTR content. From studies with the CFTR channel inhibitor, GlyH‐101, it was concluded that wild type Calu‐3 cells have a reserve of CFTR channels not located in the membrane, but available for replacement, while in the modified Calu‐3 cell line there was little or no reserve. Lubiprostone, a putative ClC‐2 activator, increased transepithelial chloride secretion in both modified and wild type Calu‐3 epithelia. Modified Calu‐3 epithelia with the residual CFTR currents blocked with GlyH‐101 responded equally well to lubiprostone as those without the blocking agent. Conclusions and implications: It appears that lubiprostone is capable of stimulating a non‐CFTR dependent transepithelial chloride secretion in Calu‐3 monolayers, with obvious implications for CF therapy. Cell lines, however, do not always reflect the behaviour of the native tissue with integrity. British Journal of Pharmacology (2007) 150, 1055–1065. doi:10.1038/sj.bjp.0707175