在增殖性视网膜病变模型中，可溶性EphrinB2和EphB4形式可减少视网膜新生血管形成。

Soluble forms of EphrinB2 and EphB4 reduce retinal neovascularization in a model of proliferative retinopathy.

作者信息

Zamora David O, Davies Michael H, Planck Stephen R, Rosenbaum James T, Powers Michael R

机构信息

Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, 97239, USA.

出版信息

Invest Ophthalmol Vis Sci. 2005 Jun;46(6):2175-82. doi: 10.1167/iovs.04-0983.

DOI:10.1167/iovs.04-0983

PMID:15914639

Abstract

PURPOSE

Ephrin ligands and their Eph receptors are key regulators of endothelial cell (EC) proliferation, migration, adhesion, and repulsion during mammalian vascular development. The hypothesis was that these molecules also play a role in pathologic neovascularization (NV) in the mouse model of oxygen-induced retinopathy.

METHODS

C57BL/6 mice at postnatal day (P)7 were exposed to 75% oxygen (O(2)) for 5 days (until P12) and allowed to recover in room air to induce retinal NV. Retinas from unexposed and hyperoxia-exposed mice between P7 to P24 were analyzed specifically for EphrinB2 and EphB4 transcript expression by RT-PCR. Phospho-Eph (p-Eph) receptor was evaluated during active EC proliferation at P15 and P17 by immunohistology. Some hyperoxia-exposed mice had one eye injected intravitreally with 150 ng/1.5 microL of soluble EphrinB2/Fc or EphB4/Fc chimeras during transition from high O(2) to room air (P12) and injected again on P14. Contralateral eyes were injected with human IgG as the control. Preretinal nuclei and retinal blood vessels were quantified at peak disease (P17).

RESULTS

EphrinB2 mRNA was constitutively expressed in the developing retina and was unchanged by hyperoxia. In contrast, EphB4 mRNA expression was modulated during normal retinal development and was altered by hyperoxia. Furthermore, p-Eph was detected in developing preretinal tufts, thus implying that Ephrin/Eph signaling system is active in this experimental model. Intravitreal injection of soluble versions of these molecules significantly reduced pathologic neovascularization. The number of preretinal nuclei in hyperoxia-treated mice was reduced by 66% (P < 0.05) in EphrinB2-injected eyes, whereas EphB4 treatment yielded a 69% reduction (P < 0.05), compared with control injections. Intraretinal vessel development was not altered by the injections.

CONCLUSIONS

These results support the hypothesis that endogenous EphrinB2 and EphB4 are regulators of retinal NV during oxygen-induced retinopathy and may be useful targets for therapeutic intervention.

摘要

目的

在哺乳动物血管发育过程中，Ephrin配体及其Eph受体是内皮细胞（EC）增殖、迁移、黏附和排斥的关键调节因子。本研究的假设是，在氧诱导性视网膜病变小鼠模型中，这些分子在病理性新生血管形成（NV）中也发挥作用。

方法

将出生后第7天（P7）的C57BL/6小鼠置于75%氧气（O₂）环境中5天（直至P12），然后在室温空气中恢复，以诱导视网膜NV。通过RT-PCR对P7至P24未暴露和高氧暴露小鼠的视网膜进行特异性分析，检测EphrinB2和EphB4转录本表达。在P15和P17通过免疫组织学评估活跃EC增殖期间的磷酸化Eph（p-Eph）受体。一些高氧暴露小鼠在从高氧向室温空气转变（P12）期间，一只眼玻璃体内注射150 ng/1.5 μL可溶性EphrinB2/Fc或EphB4/Fc嵌合体，并在P14再次注射。对侧眼注射人IgG作为对照。在疾病高峰期（P17）对视网膜前细胞核和视网膜血管进行定量分析。

结果

EphrinB2 mRNA在发育中的视网膜中持续表达，且不受高氧影响。相比之下，EphB4 mRNA表达在正常视网膜发育过程中受到调节，并因高氧而改变。此外，在发育中的视网膜前丛中检测到p-Eph，这意味着Ephrin/Eph信号系统在该实验模型中是活跃的。玻璃体内注射这些分子的可溶性形式可显著减少病理性新生血管形成。与对照注射相比，EphrinB2注射眼的高氧处理小鼠视网膜前细胞核数量减少了66%（P < 0.05），而EphB4处理使数量减少了69%（P < 0.05）。注射未改变视网膜内血管发育。