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EphB4 is expressed in preretinal neovascularization in a mouse model of oxygen‐induced retinopathy
Author(s) -
EHLKEN C,
MARTIN G,
LEINWEBER M,
HANSEN LL,
AGOSTINI HT
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.652.x
Subject(s) - neovascularization , retina , ganglion cell layer , retinopathy , inner plexiform layer , in vivo , retinal , pathology , outer plexiform layer , hypoxia (environmental) , angiogenesis , biology , medicine , ophthalmology , chemistry , cancer research , endocrinology , oxygen , neuroscience , microbiology and biotechnology , diabetes mellitus , organic chemistry
Purpose EphrinB2 is predominantly expressed in arteries, while its ligand EphB4 is predominantly expressed in veins. Activation of ephrinB2 and EphB4 by receptor dimers have been shown to enhance neovascularization, whereas inhibition of EphB4 reduced neovascularization both in vitro and in vivo in a mouse model of oxygen‐induced retinopathy (OIR). These data suggest a role of the ephrinB2‐EphB4 system in retinal neovascularization. We looked for expression of these membrane‐bound factors in a mouse model of OIR. Methods Heterogenic EphB4lacZ+/‐ mice were examined in a well‐established mouse model of oxygen‐induced retinopathy. Mice were kept in 75% oxygen for postnatal days P7‐P12. Returned to room air, they underwent a relative hypoxia and developed a proliferative retinopathy within the next 5‐7 days. Eyes were enucleated on P17‐P19 during the peak of vascular proliferation, stained for LacZ, and embedded in paraffin. Sections were investigated for LacZ staining. Results Sections show a strong expression of EphB4 in preretinal neovascularization both in small and larger vessels. EphB4 is also mildly expressed in vessels in the inner plexiform layer and in the ganglion cell layer. Conclusion The expression pattern suggests a role of EphB4 in preretinal neovascularization in a mouse model of OIR. Further studies of the intracellular localisation of EphB4 are needed to add to understanding the role of the ephrin system in OIR.