Elastin-mediated choroidal endothelial cell migration: possible role in age-related macular degeneration.
OBJECTIVE
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). Altered elastin metabolism has been described in AMD, and the present study sought to determine the effects of elastin-derived peptides (EDPs) on choroidal EC migration and proliferation.


METHODS
Migration of the chorioretinal EC line Rf/6a and a primary culture of human choroidal ECs through polycarbonate membrane inserts was quantified in the presence of elastin bioactive hexapeptides (BPs), EDPs, bovine serum albumin (BSA), or balanced salt solution. Proliferation assays and in vitro wound closure experiments were also performed in the presence of elastin fragments or balanced salt solution (control). Elastin overlay experiments were performed on sections of human eyes.


RESULTS
For both Rf/6a and human primary choroidal ECs 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 or to BSA (P < 0.05) in all experiments. In contrast, the rate of EC proliferation did not significantly change in comparison to controls. Elastin binding sites were identified on choroidal ECs in human eyes.


CONCLUSIONS
Elastin fragments increase choroidal EC migration, whereas they do not appear to increase or decrease EC proliferation. Local or systemic abnormalities in elastin physiology may participate in pathologic neovascular membrane formation in AMD.
Skeie
Jessica M
JM
Center for Macular Degeneration, Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, Iowa 52242, USA.
Mullins
Robert F
RF
D001665:Binding Sites; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002829:Choroid / Q000098:blood supply*; D020256:Choroidal Neovascularization / Q000378:metabolism* / Q000473:pathology; D004549:Elastin / Q000378:metabolism / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D007124:Immunoenzyme Techniques; D008268:Macular Degeneration / Q000378:metabolism* / Q000473:pathology; D008855:Microscopy, Electron, Scanning; D010446:Peptide Fragments / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects
D010446:Peptide Fragments; D004549:Elastin