Abstract
Abstract: :
Purpose: Oxidative stress is strongly suggested as one of the initial cause of age-related macular degeneration (AMD). However, little is known how the disease progresses subsequently. Given that histopathological co-localization of phospholipid-containing debris and macrophages in Bruch’s membrane in AMD, we hypothesize that macrophages may accumulate in order to take up oxidized lipoprotein in AMD. In this study, therefore, we investigated oxidized low density lipoprotein (OxLDL)-specific cell-surface receptor expression in choroidal neovascularization (CNV) associated with AMD. Methods: Immunohistochemistry was performed on five surgically excised CNV, using antibodies against scavenger receptors, LOX-1 (lectin-like Ox-LDL receptor-1) and SR-PSOX (scavenger receptor that binds phosphatidylserine and oxidized lipoprotein). We also used antibodies against cytokeratin, CD68 and von Willebrand factor to localize retinal pigment epithelium (RPE), macrophages and vascular endothelial cells, respectively. Results: Intense immunostaining with the anti-SR-PSOX antibody was observed at the CNV outer surface in all samples, while LOX-1 immunostaining was weak and was observed in only 2 of 5 samples. Cells expressing SR-PSOX were suspected to be macrophages and RPE, and those expressing LOX-1 to be macrophages. Conclusion: Some RPE and macrophages in CNV of AMD express cell surface scavenger receptors for OxLDL. Response to OxLDL may play a key role in AMD pathogenesis, and control of oxidative stress and macrophage responses may be potential therapeutic targets for AMD.
Keywords: 308 age-related macular degeneration • 504 oxidation/oxidative or free radical damage • 434 immunohistochemistry