Purchase this article with an account.
Nataly Strunnikova, Judit Baffi, Adriano Gonzalez, Wesam Silk, Scott W. Cousins, Karl G. Csaky; Regulated Heat Shock Protein 27 Expression in Human Retinal Pigment Epithelium. Invest. Ophthalmol. Vis. Sci. 2001;42(9):2130-2138.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. To examine the expression and regulation of an injury-related protein,
heat shock protein (Hsp) 27, in retinal pigment epithelium (RPE), since
RPE injury may be an important feature of age-related macular
methods. Retinal cross sections from eyes of Lewis rats were examined for Hsp27
in vivo by immunohistochemistry, and in vitro expression of Hsp27 in
human ARPE-19 cells was determined by Northern and Western blot
analysis. Oxidant-mediated injury was performed by exposing ARPE-19
cells to myeloperoxidase and hydrogen peroxide. Cell lines stably
expressing green fluorescent protein (GFP) targeted to the cell
membrane were used to study injury-induced membrane blebbing, and XTT
conversion was used to detect cell viability.
results. High level of Hsp27 expression was detected in vivo in ganglion cells,
RPE, and photoreceptor outer segments of rat retina. ARPE-19 cells also
expressed high levels of Hsp27 in vitro. Oxidative injury in ARPE-19
cells resulted in transcriptional and translational activation of Hsp27
and induced extensive membrane blebbing. A high level of Hsp 27 protein
was detected within membrane blebs. Increased expression of Hsp27 was
also observed in differentiated ARPE-19 cells when compared with
dividing cells. Higher Hsp27 levels in differentiated RPE cells
correlated with increased viability and phenotypically different
blebbing after exposure to the injury stimulus. In addition, sublethal
injury doses caused a moderate amount of membrane blebbing, which was
well tolerated by differentiated ARPE-19 cells.
conclusions. These results indicate that Hsp27 may be an important component of the
RPE injury response and may contribute to injury-induced membrane
blebbing in differentiated RPE cells. It is hypothesized that Hsp27
levels may play a role in disease states in the retina, such as
This PDF is available to Subscribers Only