Published online Oct 21, 2005. doi: 10.3748/wjg.v11.i39.6144
Revised: February 15, 2005
Accepted: February 18, 2005
Published online: October 21, 2005
AIM: To examine the ability of ET-1 to affect the cell functions of PSCs and the underlying molecular mechanisms.
METHODS: PSCs were isolated from the pancreas of male Wistar rats after perfusion with collagenase, and cells between passages two and five were used. Expression of ET-1 and ET receptors was assessed by reverse transcription-PCR and immunostaining. Phosphorylation of myosin regulatory light chain (MLC), extracellular-signal regulated kinase (ERK), and Akt was examined by Western blotting. Contraction of PSCs was assessed on hydrated collagen lattices. Cell migration was examined using modified Boyden chambers. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2×deoxyuridine.
RESULTS: Culture-activated PSCs expressed ETA and ETB receptors, and ET-1. ET-1 induced phosphorylation of MLC and ERK, but not Akt. ET-1 induced contraction and migration, but did not alter proliferation of PSCs. ET-1-induced contraction was inhibited by an ETA receptor antagonist BQ-123 and an ETB receptor antagonist BQ-788, whereas migration was inhibited by BQ-788 but not by BQ-123. A Rho kinase inhibitor Y-27632 abolished both contraction and migration.
CONCLUSION: ET-1 induced contraction and migration of PSCs through ET receptors and activation of Rho-Rho kinase. ETA and ETB receptors play different roles in the regulation of these cellular functions in response to ET-1.