Abstract
Purpose :
Treatment strategies for Hypoxia-induced damage to the retinal pigment epithelium (RPE) in retinal degenerative diseases are so far limited. Puerarin, a compound with properties like antiinflammation and antioxidant might be neuroprotective. Hence, we tried to investigate the cytoprotective effects of puerarin (PR) in hypoxia-induced RPE cell apoptosis and the possible mechanism of anti-apoptosis.
Methods :
Human retinal pigment epithelium cell line (ARPE19) was cultured in hypoxic- and normoxic-conditions to evaluate the effects of puerarin (PR). Immediately before they were subjected to ischemia, the cultures were treated with PR (10-1000 µM). The cytotoxicity of PR was evaluated by the WST-8 assay. The WST-8 assay and a fluorescence Annexin V staining were used to determine the number of viable cells under hypoxic-condition for evaluation of protective effect of PR. Retinal pigment epithelial barrier was evaluated by measuring transepithelial electrical resistance (TER), The localization of ZO-1 and occludin was determined by immunofluorescence microscopy and western blotting. The apoptosis protein levels of cleaved caspase 3, p-Bad, Bax ; anti-apoptosis protein level of Bcl-2 and the activities phosphorylation of PI3, Akt were determined by Western Blotting.
Results :
The hypoxia-repressed cell viability and the hypoxia-induced apoptosis was significantly rescued by the treatment with PR (50-100µM). PR decreased hypoxia-induced disruption of barrier function by eliciting the degradation of ZO-1, occludin in ARPE19 considerably .Compared with the non-treatment group, PR decreased the levels of cleaved caspase 3, p-Bad, Bax and increased the level of Bcl-2 in RPE cells. Treatment with PR induced Akt activation in the ARPE19 under hypoxic-condition. Inhibition of Akt activation (LY294002) in the PR-treated ARPE19 reversed the rescue effects of PR under hypoxic condition.
Conclusions :
PR protects hypoxia-induced RPE cells apoptosis through activation of the PI3/Akt pathway. These findings provide evidence that PR could be further investigated as a novel cell-protective agent for retinal ischemia.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.