Glycoconjugates of choroidal neovascular membranes in age-related macular degeneration.
OBJECTIVE
Choroidal neovascularization (CNV) is a complication of multiple eye diseases, including age-related macular degeneration, that usually results in irreversible vision loss. It is characterized by proliferation and growth of choroidal blood vessels through Bruch's membrane into the subpigment epithelial and/or subretinal space. The purpose of this study was to characterize the carbohydrate groups associated with CNV by lectin histochemistry.


METHODS
Frozen sections from three human eyes with CNV (two fixed eyes and one unfixed eye) were prepared. Sections containing choroidal neovascular membranes were incubated with a battery of biotinylated lectins directed against a number of distinct oligosaccharide moieties. Lectin labeling of the vessels in CNV was visualized with avidin-Texas red.


RESULTS
Several carbohydrate groups were preferentially associated with the vascular elements in CNV. Glycoconjugates that react with lectins derived from wheat germ, soybean, and hairy vetch seed (sWGA, SBA, and VVA, respectively) all showed reactivity with CNV vessels that was higher than the labeling of the surrounding matrix. SBA and sWGA also reacted with CNV vessels at low concentrations at which normal retinal and choroidal vessels were largely unlabeled.


CONCLUSIONS
Choroidal neovascular membranes possess a distinct set of carbohydrate moieties. These data may be valuable in understanding endothelial cell biology in CNV.
Mullins
Robert F
RF
Center for Macular Degeneration, Department of Ophthalmology and Visual Science, The University of Iowa Carver College of Medicine, Iowa City, IA, USA. robert-mullins@uiowa.edu
Grassi
Michael A
MA
Skeie
Jessica M
JM
D000368:Aged; D050260:Carbohydrate Metabolism; D020256:Choroidal Neovascularization / Q000378:metabolism*; D006001:Glycoconjugates / Q000378:metabolism*; D006651:Histocytochemistry; D006801:Humans; D037102:Lectins; D008268:Macular Degeneration / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D037121:Plant Lectins; D030262:Soybean Proteins; D014909:Wheat Germ Agglutinins; D010835:Phytohemagglutinins
D006001:Glycoconjugates; D037102:Lectins; D037121:Plant Lectins; D030262:Soybean Proteins; D014909:Wheat Germ Agglutinins; C028824:soybean lectin; D010835:Phytohemagglutinins