Late outgrowth endothelial progenitor cells in patients with age-related macular degeneration.
OBJECTIVE
To evaluate the feasibility of isolating and expanding endothelial progenitor cells (EPCs), in the form of late outgrowth endothelial progenitor cells (OECs), from the peripheral blood of an aged population, particularly patients affected by different forms of AMD.


METHODS
Peripheral blood mononuclear cells were collected from young control subjects (n = 18) and from elderly subjects with non-AMD/low-risk dry AMD (n = 15), high-risk dry AMD (n = 6), or neovascular AMD (nvAMD; n = 32); cultured in established conditions; and observed for appearance of OEC clusters and growth characteristics on expansion. Expression of VEGF receptor-2 (KDR) in OECs after expansion was determined by Western blot. Plasma samples of study subjects were analyzed for CRP and VEGF levels.


RESULTS
OEC cultures were successfully generated from a similar number of subjects in each group. After adjustment for all other variables, subjects with high-risk dry AMD had a 5.6-fold higher number of OEC clusters per 20 mL blood, and subjects with nvAMD had a 5.1-fold high number than did subjects with non-AMD/low-risk dry AMD (P < 0.05). High-risk dry AMD generated 63 times more (NS) and nvAMD 32-times more (P < 0.05) OECs on expansion of clusters than did non-AMD/low-risk dry AMD. Population doubling occurred significantly faster in cultures from nvAMD eyes compared to non-AMD/low-risk dry AMD eyes. In addition, a significant correlation between the number of OEC clusters, expanded OECs and levels of KDR was demonstrated.


CONCLUSIONS
An OEC population was isolated and expanded from the blood of elderly control and AMD-affected patients and demonstrated significantly higher number of initial OEC clusters and expansion potential of OECs in patients at risk for or already affected by nvAMD. OECs may be used for further phenotypic, genetic, and functional analyses in patients with nvAMD.
National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA.
Michelle
M
Thill
Natalya V
NV
Strunnikova
Marc J
MJ
Berna
Nataliya
N
Gordiyenko
Kristin
K
Schmid
Scott W
SW
Cousins
Darby J S
DJ
Thompson
Karl G
KG
Csaky
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002097:C-Reactive Protein / Q000032:analysis; D049109:Cell Proliferation; D002469:Cell Separation; D002478:Cells, Cultured; D020256:Choroidal Neovascularization / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008268:Macular Degeneration / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012171:Retinal Vessels; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D015703:Antigens, CD; D015415:Biomarkers; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D002097:C-Reactive Protein; D040301:Vascular Endothelial Growth Factor Receptor-2