Regulation of prepro endothelin-1 gene after thrombin stimulation:
involvement of calcium/calmodulin-dependent kinase in endothelial
cells.
Marsen, Tobias A., Michael S. Simonson, Michael J. Dunn.
Departments of Medicine, Physiology and Biophysics, School of
Medicine, Case Western Reserve University, Division of Nephrology,
University Hospitals of Cleveland, Cleveland, Ohio, 44106
APStracts 3:0151H, 1996.
The release of the vasoactive peptide Endothelin-1 (ET-1) is calcium
-dependent after thrombin stimulation, however little is known which
pathways are involved. We studied the importance of calcium-dependent
signal transduction pathways on prepro ET-1 mRNA induction in human
endothelial cells. Thrombin-mediated prepro ET-1 mRNA induction was
inhibited after clamping of cytosolic free calcium [Ca2+]i with
BAPTA. Chelation of extracellular calcium with EGTA also had a
significant inhibitory effect on the induction of prepro ET-1 mRNA.
The calcium ionophore A23187 induced constitutive as well as
thrombin-stimulated prepro ET-1 mRNA expression. Mobilization of
calcium stores into the cytosol by inhibition of endoplasmatic
reticulum Ca2+-ATPase with thapsigargin was effective, also, to
induce prepro ET-1 mRNA. Calmodulin antagonists W-7 and
calmidazolium, as well as calcium/calmodulin-dependent kinase II
inhibitor KN-62 significantly reduced thrombin-induced prepro ET-1
mRNA. Inhibition by cyclosporin A of the Ca2+-calmodulin-dependent
phosphatase, calcineurin, potentiated constitutive prepro ET-1 mRNA.
These data suggest that in human endothelial cells thrombin-mediated
prepro ET-1 gene induction is regulated by a stimulatory
calcium/calmodulin kinase II-dependent pathway.
Received 3 November 1995; accepted in final form 4 April 1996.
APS Manuscript Number H1030-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 23 April 96