J Korean Ophthalmol Soc.  2006 Sep;47(9):1472-1480.

Circulating Endothelial Progenitor Cells and Vasculogenic Factors in Pterygium Pathogenesis

• Song YS
• Lee JK
• Kim JC

Abstract

PURPOSE: We investigated whether endothelial progenitor cells (EPCs) and vasculogenic factors are involved in the pathogenesis of pterygium and the mechanism underlying the selective recruitment of EPCs during this process.
METHODS
We studied 13 normal controls and 28 pterygium patients [ primary (n=15), recurrent (n=13)]. Substance-P, vascular endothelial growth factor (VEGF), and stem cell factor (SCF) were measured in plasma and tears using ELISA, and circulating CD34+ and c-kit+ mononuclear cells (MNCs) by flow cytometry. Anterior segment fluorescein angiography (FAG) was performed to evaluate hypoxic conditions in the early stage of pterygium. Surgically removed pterygial tissues were analyzed immunohistochemically using the progenitor cell markers, CD34, c-kit, VEGFR-1 and VEGFR-2.
RESULTS
Anterior segment FAG findings showed an increase in non-perfusion areas and attenuated vessels in the nasal limbus during early stage pterygium. Circulating CD34+ MNCs and c-kit+ MNCs were increased in pterygium groups compared with normal controls. Systemic and local cytokines including SP, VEGF and SCF in pterygium groups were also elevated and showed positive correlations with CD34+ and c-kit+ MNC numbers. Immunohistochemical analysis of pterygium showed strong progenitor cell marker immunoreactivities.
CONCLUSIONS
EPCs might be involved in pterygium development, and ocular hypoxia triggers this neovascualrization by recruiting EPCs derived from the bone marrow via the production of systemic and local cytokines.

Keyword

Endothelial progenitor Cells; Pterygium; Stem cell factor; Substance-P; Vascular endothelial growth factor

MeSH Terms

Anoxia
Bone Marrow
Cytokines
Enzyme-Linked Immunosorbent Assay
Flow Cytometry
Fluorescein Angiography
Humans
Plasma
Pterygium*
Stem Cell Factor
Stem Cells*
Vascular Endothelial Growth Factor A
Vascular Endothelial Growth Factor Receptor-1
Vascular Endothelial Growth Factor Receptor-2
Cytokines
Stem Cell Factor
Vascular Endothelial Growth Factor A
Vascular Endothelial Growth Factor Receptor-1
Vascular Endothelial Growth Factor Receptor-2