[Endoplasmic reticulum stress participates in the cell apoptosis process in experimental retinal detachment].
OBJECTIVE
To determine whether the endoplasmic reticulum stress participates into the apoptosis process of the retina during experimental retinal detachment-by detecting the level of mRNA and protein of the GADD153, the marker of endoplasmic reticulum stress.


METHODS
Completely random design is applied. Experimental retinal detachment was created in the left eyes of 77 wistar rats by injecting hyaluronic acid into the subretinal space. Rats were sacrificed at 1/2 d, 1 d, 2 d, 4 d, 8 d, 16 d and 32 d after creation of retinal detachment. Apoptosis of retinal cells was detected by TdT-mediated fluorescein-16-dUTP nick-end labeling (TUNEL) assay. GADD153 mRNA expression in the retina was determined using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The GADD153 protein expression was determined using western blotting. Retinal sections were studied by immunofluorescence labeling and confocal microscopy. The SPSS 10.0 software was applied to analyze data; Kruskal wallis test was applied to analyze the data about the apoptotic rate of retinal cells and the expression of GADD153 mRNA; One-way ANOVA test was applied to analyze the data about expression of GADD153 protein. P < 0.05 represents statistically significant difference.


RESULTS
TUNEL positive staining cells were mainly presented in photoreceptor cell layer, peaked at 24 days and markedly decreased at 8 days after retinal detachment. The difference of apoptotic retinal cell rate between groups is significant (chi2 = 22.423, P < 0.05); The expression of retinal GADD153 mRNA was significantly increased at 1/2 d, 1 d, 2 d, 4 d after retinal detachment (chi2 = 27.223, P < 0.05); The expression of retinal GADD153 protein was significantly increased at these days (F = 16.052, P < 0.05). GADD153-positive cells were located in the photoreceptor cell layer.


CONCLUSIONS
GADD153, the maker of endoplasmic reticulum stress mediated apoptosis, is activated and over-expressed, associated with the occurrence of apoptosis during retinal detachment. Endoplasmic reticulum stress participates into the apoptosis process during retinal detachment.
Liu
Hai-Yang
HY
Department of Ophthalmology, Affiliated First People's Hospital of Shanghai Jiao Tong University, Shanghai 200080, China.
Qian
Jin
J
Wang
Feng-Hua
FH
Xu
Xun
X
Zhang
Xi
X
Zhang
Xian
X
Li
Su-Yan
SY
Zhang
Zheng-Pei
ZP
Sun
Xiao-Dong
XD
D000818:Animals; D017209:Apoptosis; D017931:DNA Primers; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012163:Retinal Detachment / Q000378:metabolism* / Q000473:pathology; D051742:Transcription Factor CHOP / Q000378:metabolism
D017931:DNA Primers; C497251:Ddit3 protein, rat; D051742:Transcription Factor CHOP