Objective To assess the protective effect of recombinant human erythropoietin (EPO) on human retinal pigment epithelial (RPE) cells injured by light. Methods Cultured human RPE cells were exposed to light for 12 hours, and the culture was stopped 24 hours later. The 3(4,5dimethylthiazole2y1)2,5diphenyl tetrazolium bromide (MTT) cell viability assay and annexin V flunorescein isothiocyanate/propidium iodium labeling and flow cytometry were used to assess the effects of EPO with different concentration on the cellular viability and apoptosis of human RPE cells. The protective effect and mechanism of EPO on RPE cells injured by light was detected by adding AG490. Results EPO, especially with the concentration of 40 IU/ml, obviously increased the cellular viability of RPE cells and apparently decrease the cellular apoptosis induced by light injury. After adding AG490, the effects of EPO on cellular viability and apoptosis were inhibited. Conclusion It is suggested that EPO can protect the human RPE cells from lightinduced injures, and its protective mechanism works after the combination of EPO and its receptor.
Objective To observe the effects of basic fibroblast growth factor (bFGF) on the expression of heat shock protein 70 (HSP70) in ratrs retina after iscbemia/reperfusion injury.Methods The rat model of experimental retinal ischemia/reperfusion injury was made by increasing the intraocular pressure. Tweenty-four Wistar rats were divided into normal (3 rats) and operation group (21 rats) randomly. The latter group was subdivided into group 0 hour, 4, 8, 12, 24, 48 and 72 hours after reperfusion, in which the left eyes of the rats were in the ischemia/reperfusion groups and the right ones were in the treatment groups (bFGF 2 t~g intracameral injection). The expression of HSP70 was observed by strept avidin-biotin complex (SABC) immunohistochemistry. Results No HSP70 positive cells were found in normal group; a few of HSP70 positive cells were found 0 hour after reperfusion [20.8±4. 5) cells/mm2], and increased gradually until reached the peak 24 hours later [(111.2±4.4) cells/mm2] and then decreased gradually. Few HSP70 positive cells were found 72 hours after reperfusion. The amount of HSP70 positive cells increased in treatment group at all time courses, and the peak time was earlier and longer than that in ischemia group. HSP70 positive cells distributed extensively in retinal ganglion cell layer and inner nucleous layer. The difference of the amount of HSP70 positive cells between the two groups was significant (Plt;0.05) 8, 12, 24, 48 and 72 hours after reperfusion.Conclusion bFGF can enhance the expression of HSP70 in rat’s retina after retinal ischemia/reperfusion injury.(Chin J Ocul Fundus Dis，2004，20：37-39)