Alpha B-crystallin expression in human and rat hepatic stellate cells

Background/Aims: We searched for factors implicated in early hepatic stella te cell (HSC) activation in diseased liver, by means of suppression subtrac tive hybridization (SSH). Methods: SSH was performed between messenger RNA (mRNA) from normal rat HSC and mRNA from HSC, isolated from rats with acute D-galactosamine (Gal)-ind uced hepatitis. Results: One of the potentially upregulated factors which we found was alph a B-crystallin (ABCRYS), a small heat-shock protein and a chaperone known t o protect the cell against protein degradation in conditions of cellular st ress and known to associate with various types of intermediate filaments. U pregulation of ABCRYS mRNA in HSC, following Gal-intoxication (3.5-fold) as well as by culturing the HSC on plastic (20-30-fold), was confirmed by qua ntitative realtime reverse transcription polymerase chain reaction. The exp ression of ABCRYS protein in human and rat HSC was demonstrated by immunohi stochemistry, in vitro and in vivo, in normal and diseased liver. Double-st aining co-localized ABCRYS immunoreactivity with alpha-smooth muscle actin immunoreactivity in human liver and with desmin immunoreactivity in rat liv er. In vivo upregulation of ABCRYS protein following Gal-intoxication was a lso shown, by comparison with desmin expression. Conclusions: Human and rat HSC express ABCRYS mRNA and protein. Both are ra pidly upregulated following HSC activation. (C) 2001 European Association f or the Study of the Liver. Published by Elsevier Science B.V. All rights re served.