Abstract
Purpose::
Endothelial cell (EC) migration is a key event in angiogenesis, and is likely to play an important role in choroidal neovascularization in age-related macular degeneration (AMD). Systemic or local sources of extracellular matrix proteolytic fragments, such as elastin-derived peptides (EDPs), may promote neovascularization by increasing choroidal endothelial cell migration. In this study we employed endothelial cell cultures as a model for studying altered cell migration in response to biochemical stimuli, including EDPs.
Methods::
The chorioretinal EC line RF/6A and a primary culture of human choroidal ECs were seeded on the top surface of polycarbonate membrane inserts with 8 um diameter pores in serum-free medium. Media containing elastin bioactive hexapeptides (BPs), EDPs, or balanced salt solution were added to the lower chamber and ECs were allowed to migrate for 8 hours. The polycarbonate membranes were then fixed and the lower surfaces were examined by scanning electron microscopy. Cells which had migrated through the membrane were counted from 5-10 non-overlapping fields and significance was determined using a Student’s t-test.
Results::
For RF/6A cells exposed to EDPs or BPs, the number of ECs that migrated through the polycarbonate membrane was significantly higher than ECs exposed to balanced salt solution alone (p<0.05). Human choroidal ECs also showed increased migration when exposed to EDPs or BPs in comparison to balanced salt solution (p<0.05).
Conclusions::
Biochemical stimuli, EDPs and BPs, increase choroidal EC migration. These results suggest that systemic or local sources of these molecules contribute to angiogenesis in the choroid and may be involved in pathologic neovascular membrane formation in AMD.
Keywords: age-related macular degeneration • choroid: neovascularization • vascular cells