Glutamine protects intestinal epithelial cells: role of inducible
hsp70.
Wischmeyer, Paul E., Mark W. Musch, Mary Beth Madonna, Ronald Thisted,
and Eugene B. Chang.
IBD Research Center, Department of Medicine, University of Chicago,
Chicago, Illinois. 60637, Dept. of Biostatistics, University of
Chicago, Chicago, Illinois, 60637
APStracts 3:0250G, 1996.
Glutamine (GLN) protects gut mucosa against injury and promotes
mucosal healing. Because the induction of heat shock proteins (hsps)
protects cells under conditions of stress, we determined if GLN
conferred protection to stress in an intestinal epithelial cell line
through hsp induction. GLN added to IEC-18 cells induces an increase
in hsp70 protein, a concentration dependent effect also seen with
mRNA. Two forms of injury were used: (1) lethal heat (49 C) and (2)
oxidant, and viability determined by 51Cr release. GLN treated cells
were significantly more resistant to injury. DON [diazo-oxo
-norleucine, a non-metabolizable analog of GLN], treatment induced
hsp70 and protected cells from injury, but less than GLN. This
findings suggest that GLN's effects on hsp70 induction and providing
cellular protection are mediated by both metabolic and non-metabolic
mechanisms. To determine if hsp induction was central to the action
of GLN and DON, quercetin, which blocks hsp induction, was used.
Quercetin blocked both hsp70 induction and the protective effect of
GLN and DON. We conclude that GLN's protective effects in intestinal
epithelial cells are in part mediated by hsp70 induction.
Received 8 December 1995; accepted in final form 15 October 1996.
APS Manuscript Number G516-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996