Stable expression of a human hsp70 gene in a rat myogenic cell line
confers protection against endotoxin.
Chi, Shun-Hua, and Ruben Mestril.
Department of Medicine, Division of Endocrinology & Metabolism,
University of California, San Diego, La Jolla, CA 92093-0618
APStracts 2:0360C, 1995.
Recent reports show that a pre-heat shock has a protective effect
against endotoxin "in vivo" in rodents. It remains unclear
what actually confers the protection against endotoxin. One candidate
for this protective effect is the heat shock protein 70 (hsp70). We
found that a mild heat shock pretreatment in the rat myogenic cell
line, H9c2, confers resistance to a subsequent exposure to endotoxin.
A myogenic rat cell line stably transfected with the human inducible
hsp70 exhibits an increased survival rate as compared to cells stably
transfected solely with the selectable neomycin marker gene or the
parental cell line H9c2 when exposed to endotoxin. The mechanism of
endotoxin-induced cell injury is postulated to be through the
generation of nitric oxide, tumor necrosis factor [alpha] or
interleukin-1 [beta]. We did not detect the generation of any of
these two cytokines or nitric oxide in these myogenic cells during
exposure to endotoxin. We conclude that hsp70, regardless of the
particular mechanism of cytotoxicity, plays a role in protecting the
cell against the deleterious effects of endotoxin.
Received 21 June 1995; accepted in final form 4 October 1995.
APS Manuscript Number C362-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95