Abstract
Purpose: :
Vascular endothelial growth factor (VEGF) plays a central role in the pathogenesis of age-related macular degeneration by promoting migration, proliferation and permeability of choroidal endothelial (CE) cells. Our previous studies showed that platelet-activating factor (PAF) may play a role in the choroidal neovascularization by promoting CE cell migration and by upregulating VEGF level in the retinal pigment epithelial cells. In the current study, we determined if PAF increases the permeability of CE cells.
Methods: :
The permeability of monkey CE cells was determined by an In Vitro Vascular Permeability Assay Kit. Monkey CE was purchased from American Type Culture Collection and maintained in Eagle's minimal essential medium until 80% confluent. CE cells were harvested and seeded onto the upper surface of the porous membrane in the upper chamber to allow formation of cell monolayer. Following starvation, the cell monolayers were treated with PAF, PAF with Web 2086, an antagonist to PAF, or VEGF. Cell monolayer treated with culture media only was used as the negative control. The permeability of the CE monolayer under different conditions were measured and compared.
Results: :
The CE cell permeability in the presence of PAF is significantly higher than that of the negative control, and is comparable to that in the presence of VEGF. The addition of WEB 2086 completely blocked the effect of PAF on the permeability of CE cells.
Conclusions: :
PAF may play a role in the pathogenesis of AMD by increasing CE permeability.
Keywords: age-related macular degeneration • growth factors/growth factor receptors