[The research of the protection of recombinant human erythropoietin in human RPE cells by light-induced injuries].

Objective: The aim of this study was to assess the protection of recombinant human erythropoietin (rhEPO) in light-induced injures in human retinal pigment epithelial (RPE) cells.
Methods: It was a experimental study. Cultured human RPE cells were exposed to light of 8w 2000 +/- 500 Lux for 12 hours. The 3-(4,5-dimethylthiazole-2y1)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay were used to assess the effects of rhEPO in light-induced injury on human RPE cells. The effect of inhibiting apoptosis of rhEPO was detected by AnnexinV-fluorescein isothiocyanate/Propidium iodium labeling and flow cytometry. The enzyme linked immunosorbant assay (ELISA) and immunocytochemical staining were used to assess the expressions of caspase-3 treated by different doses of rhEPO in light-induced injury on human RPE cells and examine the protective mechanism of rhEPO by treatment with AG490 (the special inhibitor of jak2).
Results: There was a significant increase of inhibiting apoptosis in every rhEPO group, and cell viability was the highest in 40 U/ml rhEPO group, the value was 4.93 +/- 1.45/ml. The decrease in expression of caspase-3 was the most obvious in 40 U/ml rhEPO group, in which the value was 0.125 +/- 0.029 ng/ml. There was a significant increased effect on inhibiting apoptosis in every rhEPO group, and it was the most conspicuous in 40 U/ml rhEPO group. But these increased cell viability and effect on inhibiting apoptosis in rhEPO group were restrained by AG490, in which the value of apoptosis was 11.29 +/- 2.11/ml and the density of caspase-3 increased to 0.362 +/- 0.042 ng/ml.
Conclusions: It is suggested that rhEPO can protect human RPE cells from the light-induced injures. Its protective mechanism is principally mediated by the EPO-EPOR pathway, which subsequently leads to jak2 activation.