Neuropilin-1 expression by endothelial cells and retinal pigment epithelial cells in choroidal neovascular membranes.
OBJECTIVE
To determine if vascular endothelial growth factor (VEGF) coreceptor neuropilin-1 (NP-1) is expressed in choroidal neovascularization (CNV) and to localize the expression.


METHODS
Laboratory investigation.


METHODS
Six CNV membranes (CNVMs) obtained from patients with subfoveal CNV attributable to age-related macular degeneration (AMD) underwent immunohistochemistry for VEGF receptor-2 (VEGFR-2) and NP-1. The positive cell types were identified by double staining with anticytokeratin, anti-CD31, and antismooth muscle actin (SMA).


RESULTS
Immunohistochemical staining revealed positivity for VEGFR-2 and NP-1 in all six CNVMs. Both receptors were strongly expressed by new choroidal endothelial cell forming vessels and CD-31-positive cells in the nonvascular area. They were also expressed in the pigmented retinal pigment epithelial layer and by cytokeratin-positive, nonpigmented retinal pigment epithelium cells in the nonvascular area. The nonpigmented retinal pigment epithelium cells positive for VEGFR-2 and NP-1 were highly colocalized with SMA.


CONCLUSIONS
The presence of both VEGF and NP-1 suggest that NP-1 may play a role in the evolution of CNV in AMD.
Lim
Jennifer I
JI
Doheny Retina Institute of the Doheny Eye Institute and Department of Ophthalmology, University of Southern California Keck School of Medicine, 1450 San Pablo Street, Los Angeles, CA 90033, USA. jennifil@usc.edu
Spee
Christine
C
Hangai
Masanori
M
Rocha
Jorge
J
Ying
Howard S
HS
Ryan
Stephen J
SJ
Hinton
David R
DR
D000199:Actins / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000098:blood supply*; D020256:Choroidal Neovascularization / Q000209:etiology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D008268:Macular Degeneration / Q000150:complications / Q000378:metabolism; D008297:Male; D008566:Membranes / Q000378:metabolism; D018613:Microscopy, Confocal; D039942:Neuropilin-1 / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D000199:Actins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D039942:Neuropilin-1; D040301:Vascular Endothelial Growth Factor Receptor-2