Trypsin activates pancreatic duct epithelial cell ion channels through proteinase-activated receptor-2

Toan D. Nguyen, Mark W. Moody, Martin Steinhoff, Charles Okolo, Duk Su Koh, Nigel W. Bunnett

Research output: Contribution to journalArticle

Abstract

Proteinase-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved by trypsin within the NH2-terminus, exposing a tethered ligand that binds and activates the receptor. We examined the secretory effects of trypsin, mediated through PAR-2, on well-differentiated nontransformed dog pancreatic duct epithelial cells (PDEC). Trypsin and activating peptide (AP or SLIGRL-NH2, corresponding to the PAR-2 tethered ligand) stimulated both an 125I- efflux inhibited by Ca2+-activated Cl- channel inhibitors and a 86Rb+ efflux inhibited by a Ca2+-activated K+ channel inhibitor. The reverse peptide (LRGILS-NH2) and inhibited trypsin were inactive. Thrombin had no effect, suggesting absence of PAR-1, PAR-3, or PAR-4. In Ussing chambers, trypsin and AP stimulated a short- circuit current from the basolateral, but not apical, surface of PDEC monolayers. In monolayers permeabilized basolaterally or apically with nystatin, AP activated apical Cl- and basolateral K+ conductances. PAR-2 agonists increased [Ca2+](i) in PDEC, and the calcium chelator BAPTA inhibited the secretory effects of AP. PAR-2 expression on dog pancreatic ducts and PDEC was verified by immunofluorescence. Thus, trypsin interacts with basolateral PAR-2 to increase [Ca2+](i) and activate ion channels in PDEC. In pancreatitis, when trypsinogen is prematurely activated, PAR-2- mediated ductal secretion may promote clearance of toxins and debris.

Original languageEnglish (US)
Pages (from-to)261-269
Number of pages9
JournalJournal of Clinical Investigation
Volume103
Issue number2
DOIs
StatePublished - Jan 1999

ASJC Scopus subject areas

  • Medicine(all)

Fingerprint Dive into the research topics of 'Trypsin activates pancreatic duct epithelial cell ion channels through proteinase-activated receptor-2'. Together they form a unique fingerprint.

  • Cite this

    Nguyen, T. D., Moody, M. W., Steinhoff, M., Okolo, C., Koh, D. S., & Bunnett, N. W. (1999). Trypsin activates pancreatic duct epithelial cell ion channels through proteinase-activated receptor-2. Journal of Clinical Investigation, 103(2), 261-269. https://doi.org/10.1172/JCI2539