Objective：To observe the expression of gene and protein l evel of unfolded protein, glucoseregulated protein 78 (GRP78), after retinal d etachment (RD); to find out the relationship between UPR and the cell damage after RD. Methods：Eightyeight Wistar rats were divided into 2 groups: con trol group (11 rats) and RD group (77 rats). In RD group, subretinal injection with 10 mg/ml hyaluronic acid sodium was performed on the left eyes of the rats t o set up RD model, and the left eyes and retinal tissue were collected 1/2 day, 1 day, 2, 4, 8, 1 6 and 32 days after RD; there were 11 rats in each subgroup. The expression of G RP78 mRNA in retina tissue was detected by semiquantitative reverse transcript i on polymerase chain reaction (RT－PCR), the expression of GRP78 protein level wa s detected by Western blotting, and the distribution of GRP78 in each retinal lay er was observed by immunofluorescence labeling method and confocal microscopy. Results：The expression of retinal GRP78 mRNA significantly in creased in 1/2 day , 1 day, 2, and 4 days subgroups after RD (Plt;0.05). The expression of GRP7 8 protein significantly increased in each subgroup after RD compared with which in the control group, and reached the peak in 8, 16, and 32 days subgroups. The expres sion of GRP78 protein was detected in all of the retinal layers after RD. Conclusion：The protection mechanism of UPR starts up after RD, and l eads the correc t pucker of the protein and reduces cellular injury by upregulating the expres s ion of GRP78, which provide the theoretic basis for reducing the cellular injury and improving the visual function in patients with RD.
Objective To investigate the expression and significance of inducible co-stimulator (ICOS) in experimental autoimmune uveoretinitis (EAU). Methods EAU was induced in 24 Lewis rats (immune group) by immunization with retinal S-antigen (50 mu;g) and complete Freundprime;s adjuvant, and another 4 rats were in the control group. Anterior segment of the ratsprime; eyes were observed by split microscope every day. Immunohistochemical staining was performed using polyclonal antibodies to ICOS on the sections of the spleen which were obtained from the rats in immune group at the 7th, 12th, 15th and 21st days after immunisation respectively. Western blotting was performed to investigate the dynamic expression of ICOS protein in the spleen. The same procedures were made at the corresponding time points in the rats in control group. Results A few ICOS positive cells were observed in the normal spleen. The number of ICOS positive cells in immune group increased obviously at the 7th and 12th days after immunization, reached the peak at the 15th day, and decreased at the 21st day which was still higher than that in the control group. The result of Western blotting showed that the dynamic changes of ICOS protein was identical with the changes of positive-cell number detected by immunohistochemistry. Conclusions The enhanced expression of ICOS happens before EAU occurs, which increases when the inflammation occurs and deteriorates, and decreases at the alleviative stage of EAU. It suggests that ICOS participates in the formation, development and disappearance of EAU and plays an important role in the incidence of EAU. (Chin J Ocul Fundus Dis, 2005,21:114-117)