Background:Retinal degenerative diseases are the leading causes of blindness in developed world.Retinal progenitor cells (RPCs) play a key role in retina restoration.Triamcinolone acetonide (TA) is widely used for the treatment of retinal degenerative diseases.In this study,we investigated the role of TA on RPCs in hypoxia condition.Methods:RPCs were primary cultured and identified by immunofluorescence staining.Cells were cultured under normoxia,hypoxia 6 h,and hypoxia 6 h with TA treatment conditions.For the TA treatment groups,after being cultured under hypoxia condition for 6 h,RPCs were treated with different concentrations of TA for 48-72 h.Cell viability was measured by cell counting kit-8 (CCK-8) assay.Cell cycle was detected by flow cytometry.West blotting was employed to examine the expression ofcyclin D 1,Akt,p-Akt,nuclear factor (NF)-κB p65,and caspase-3.Results:CCK-8 assays indicated that the viability of RPCs treated with 0.01 mg/ml TA in hypoxia group was improved after 48 h,comparing with control group (P ＜ 0.05).After 72 h,the cell viability was enhanced in both 0.01 mg/ml and 0.02 mg/ml TA groups compared with control group (all P ＜ 0.05).Flow cytometry revealed that there were more cells in S-phase in hypoxia 6 h group than in normoxia control group (P ＜ 0.05).RPCs in S and G2/M phases decreased in groups given TA,comparing with other groups (all P ＜ 0.05).There was no significant difference in the total Akt protein expression among different groups,whereas upregulation ofp-Akt and NF-κB p65 protein expression and downregulation of caspase-3 and cyclin D1 protein expression were observed in 0.01 mg/ml TA group,comparing with hypoxia 6 h group and control group (all P ＜ 0.05).Conclusion:Low-dose TA has anti-apoptosis effect on RPCs while it has no stimulatory effect on cell proliferation.