Abstract

Objective: To investigate the expression of proangiogenic and antiangiogenic factors, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in retinal pigment epithelial (RPE) cells after photodynamic therapy (PDT), especially focusing on their change in the presence of triamcinolone acetonide.

Methods: Firstly, the cellular uptake of verteporfin was quantified after confluent ARPE-19 (human retinal pigment epithelial) cells were exposed to 5 μg/ml verteporfin combined with or without 1 μg/ml triamcinolone acetonide for 1 h. Secondly, ARPE-19 cells exposed to various doses of verteporfin were irradiated with 120 mJ/cm² light. After incubation with or without 1 μg/ml triamcinolone acetonide for 2 days, cell viability and expressions of VEGF and PEDF were assessed.

Results: Cellular uptake of verteporfin was not significantly changed by the presence of 1 μg/ml triamcinolone acetonide. In addition, 0.01–0.1 μg/ml of verteporfin showed a dose-dependent toxicity on the ARPE-19 cells 2 days after the light exposure. The presence of verteporfin at a concentration of 0.01 μg/ml did not affect the cell viability but significantly increased VEGF (p<0.001) and reduced PEDF (p = 0.03) expression. Administration of triamcinolone acetonide significantly suppressed both this increase in VEGF (p<0.001) and decrease in PEDF (p = 0.001).

Conclusions: VEGF was increased and PEDF reduced in cultured RPE cells shortly after PDT even at a sublethal dose. Triamcinolone acetonide suppressed this proangiogenic response.