PubMed Journals: Am J Physiol
Source: PMID: 7515578
⇦ ⇨ Am J Physiol. 1994 May;266(5 Pt 1):L493-501.
Calu-3: a human airway epithelial cell line
that shows cAMP-dependent Cl- secretion.
Shen BQ(1), Finkbeiner WE, Wine JJ, Mrsny
RJ, Widdicombe JH.
(1) Department of Physiology,
University of California, San Francisco
Of 12 cell lines derived from human lung
cancers, only Calu-3 cells showed high
transepithelial resistance (Rte) and increases
in short-circuit current (Isc) in response
to mediators. Calu-3 cells formed polarized
monolayers with tight junctions and Rte
of approximately 100 omega.cm2. Baseline
Isc was approximately 35 microA/cm2 and
was increased by approximately 75 microA/cm2
on elevation of intracellular adenosine
3',5'-cyclic monophosphate (cAMP) by isoproterenol.
Flux studies showed that the increase in
Isc was due to Cl- secretion. Forskolin
and permeant analogues of cAMP also increased
Isc. Consistent with the presence of cAMP-dependent
Cl- secretion, immunoprecipitation demonstrated
the presence of the cystic fibrosis transmembrane
conductance regulator (CFTR). Bradykinin,
methacholine, trypsin, and histamine all
transiently (15-30 s) elevated Isc, probably
by increasing intracellular Ca concentration.
Experiments in which the basolateral membrane
was permeabilized with nystatin indicated
that CFTR was substantially activated under
baseline conditions and that Ca-activated
Cl- channels were absent from the apical
membrane. We anticipate that Calu-3 cells
will prove useful in the study of Cl- secretion
and other functions of human airway epithelial
DOI: 10.1152/ajplung.1994.266.5.L493 PMID: 7515578
[Indexed for MEDLINE]