Dexamethasone regulated expression of pancreatic lipase and two
related proteins in ar42j cells.
Kullman, John, Catherine Gisi, and Mark E. Lowe.
Departments of Pediatrics and of Molecular Biology and
Pharmacology, Washington University School of Medicine, St. Louis, MO
63110
APStracts 2:0218G, 1995.
The pancreas makes two pancreatic proteins (PLRP1 and PLRP2) with
marked homology to pancreatic lipase (PL). To determine if a
pancreatic acinar cell line, AR42J, also expresses PLRP1 and PLRP2,
we examined the cells for the presence of PL, PLRP1, and PLRP2. RNA
Blot analysis with specific probes and immunoblot analysis with anti
-peptide antibodies demonstrated the presence of mRNA and protein for
all three homologues in AR42J cells. Additionally, we showed that
dexamethasone decreased PLRP1 mRNA levels 2-fold and increased PLRP2
mRNA 20-fold, but had little effect on PL or colipase mRNA.
Extracellular PLRP2 protein levels increased 3-fold and intracellular
PLRP2 protein levels increased about 4-fold. The characteristics of
the dexamethasone-induced increase in PLRP2 mRNA, a rapid change
requiring new protein synthesis that is independent of mRNA turnover,
suggested that dexamethasone regulated transcription. We conclude
that AR42J cells synthesize and secrete PL, PLRP1, and PLRP2 and that
dexamethasone discoordinately regulates the expression of the three
genes.
Received 2 March 1995; accepted in final form 14 October 1995.
APS Manuscript Number G94-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95