HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Palmer, M. L. Articles by O'Grady, S. M. Search for Related Content PubMed PubMed Citation Articles by Palmer, M. L. Articles by O'Grady, S. M.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

Protease-activated receptor regulation of Cl^– secretion in Calu-3 cells requires prostaglandin release and CFTR activation

Departments of ¹Physiology and ²Animal Science, University of Minnesota, St. Paul, Minnesota; and ³Department of Veterinary Pharmacology, Seoul National University, Seoul, Republic of Korea

Submitted 16 September 2005 ; accepted in final form 20 November 2005

Human lung epithelial (Calu-3) cells were used to investigate the effects of protease-activated receptor (PAR) stimulation on Cl^– secretion. Quantitative RT-PCR (QRT-PCR) showed that Calu-3 cells express PAR-1, -2, and -3 receptor mRNAs, with PAR-2 mRNA in greatest abundance. Addition of either thrombin or the PAR-2 agonist peptide SLIGRL to the basolateral solution of monolayers mounted in Ussing chambers produced a rapid increase in short-circuit current (I_sc: thrombin, 21 ± 2 µA; SLIGRL, 83 ± 22 µA), which returned to baseline within 5 min after stimulation. Pretreatment of monolayers with the cell-permeant Ca²⁺-chelating agent BAPTA-AM (50 µM) abolished the increase in I_sc produced by SLIGRL. When monolayers were treated with the cyclooxygenase inhibitor indomethacin (10 µM), nearly complete inhibition of both the thrombin- and SLIGRL-stimulated I_sc was observed. In addition, basolateral treatment with the PGE₂ receptor antagonist AH-6809 (25 µM) significantly inhibited the effects of SLIGRL on I_sc. QRT-PCR revealed that Calu-3 cells express mRNAs for CFTR, the Ca²⁺-activated KCNN4 K⁺ channel, and the KCNQ1 K⁺ channel subunit, which, in association with KCNE3, is known to be regulated by cAMP. Stimulation with SLIGRL produced an increase in apical Cl^– conductance that was blocked in cells expressing short hairpin RNAs designed to target CFTR. These results support the conclusion that PAR stimulation of Cl^– secretion occurs by an indirect mechanism involving the synthesis and release of prostaglandins. In addition, PAR-stimulated Cl^– secretion requires activation of CFTR and at least two distinct K⁺ channels located in the basolateral membrane.

cystic fibrosis transmembrane conductance regulator; KCNQ1; calcium-activated potassium channels; KCNN4; cAMP

This article has been cited by other articles:

				A. P. Joy and E. A. Cowley 8-iso-PGE2 Stimulates Anion Efflux from Airway Epithelial Cells via the EP4 Prostanoid Receptor Am. J. Respir. Cell Mol. Biol., February 1, 2008; 38(2): 143 - 152. [Abstract] [Full Text] [PDF]

				J. Q. van der Merwe, M. D. Hollenberg, and W. K. MacNaughton EGF receptor transactivation and MAP kinase mediate proteinase-activated receptor-2-induced chloride secretion in intestinal epithelial cells Am J Physiol Gastrointest Liver Physiol, February 1, 2008; 294(2): G441 - G451. [Abstract] [Full Text] [PDF]

				S. Y. Lee, M. L. Palmer, P. J. Maniak, S. H. Jang, P. D. Ryu, and S. M. O'Grady P2Y receptor regulation of sodium transport in human mammary epithelial cells Am J Physiol Cell Physiol, November 1, 2007; 293(5): C1472 - C1480. [Abstract] [Full Text] [PDF]

				J. G. Kirkland, G. S. Cottrell, N. W. Bunnett, and C. U. Corvera Agonists of protease-activated receptors 1 and 2 stimulate electrolyte secretion from mouse gallbladder Am J Physiol Gastrointest Liver Physiol, July 1, 2007; 293(1): G335 - G346. [Abstract] [Full Text] [PDF]