Ab-crystallin protects glial cells from hypertonic stress.
Kegel, Kimberly B., Akiko Iwaki, Toru Iwaki, and James E. Goldman.
Department of Pathology, Division of Neuropathology and Center for
Neurobiology and Behavior, Columbia University College of Physicians
and Surgeons, New York, NY
APStracts 2:0347C, 1995.
[alpha]B-crystallin and the small stress protein, hsp27, share
structural similarities and are coordinately induced by classical
stress stimuli. We have recently observed that hypertonic stress
produced by high NaCl concentrations selectively induces [alpha]B
-crystallin in glial cells. To examine divergence of the functional
properties of these two related proteins, we have constructed stable,
[alpha]B-crystallin-expressing glial cell lines from the U251MG
glioma cells, which are normally deficient in [alpha]B-crystallin
expression but constitutively express hsp27 . These transfected cells
lines are more resistant to acute hypertonic stress than the parental
line from which they were derived. Moreover, the parental line
acclimates to stepwise increases in hypertonicity and upregulates
endogenous [alpha]B-crystallin in the process, but not hsp27. The
overexpression of hsp27 and [alpha]B-crystallin in NIH3T3
fibroblasts, a cell line that normally expresses little [alpha]B
-crystallin and no hsp27, does not result in increased survival. This
suggests that [alpha]B-crystallin interacts with cell-type specific
mechanisms to aid in protection from hypertonic stress.
Received 15 June 1995; accepted in final form 19 September 1995.
APS Manuscript Number C340-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95