Institute for Experimental Ophthalmology and Interdisciplinary Center for Clinical Research, School of Medicine, Domagkstraße 3,15, D-48149 Münster, Germany.
Exp Eye Res. 2011 Feb;92(2):128-37. doi: 10.1016/j.exer.2010.12.002. Epub 2010 Dec 11.
To examine retinal angiogenesis in the Royal College of Surgeons rat (RCS) serving as a model for ischemic proliferative retinopathies at morphological, proteomic and mRNA levels in order to evaluate the interplay of morphological and molecular changes in the course of the disease. Photoreceptor degeneration was confirmed by histological cross-sections and optical coherence tomography. The capillary retinal network was visualized in RCS rats aged between 14 and 45 days (P14-P45) by perfusion with high molecular weight fluorescein isothiocyanate-labeled dextran and compared with corresponding Sprague-Dawley rats. Vascular crosstalks within central areas to peripheral retinal eccentricities were analyzed. The expression of vascular growth-associated factors and their receptors in the course of the abnormal vascular development, namely vascular endothelial growth factor (VEGF), VEGF receptor subtype 1 (VEGF-R1) and -2 (VEGF-R2), somatostatin (SRIF), somatostatin receptor subtype 2 (Sstr-2), angiopoietin-2 (Ang-2) and tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (Tie-2), was analyzed by immunohistochemistry, western blotting and quantitative real-time polymerase chain reaction. Underperfused areas without capillarization were found in the middle and peripheral retinal eccentricities of RCS rats until P29. Through the course of vascularization previously low perfused areas became completely perfused, but were characterized by significantly increased neovascularizations. Western blotting revealed specific expression of growth-associated factors and their receptors in the course of capillary development. VEGF was significantly increased until P29 in RCS rats, while SRIF was significantly upregulated at P21 and P29 at proteomic level in SD rats. At mRNA level Ang-2 was significantly upregulated in RCS rats at P29, VEGF-R1 and VEGF-R2 at P36 and SRIF at P36. Initial incomplete perfusion is followed by aberrant vessel formation. VEGF, SRIF, Ang-2 and their receptors are regulated at protein and mRNA levels, providing therapeutic possibilities for treating ischemic proliferative retinopathies in the course of the disease.
为了在形态学、蛋白质组学和 mRNA 水平上研究作为缺血性增生性视网膜病变模型的皇家外科医生学院大鼠（RCS）中的视网膜血管生成，以评估疾病过程中形态学和分子变化的相互作用。通过组织学切片和光相干断层扫描证实了光感受器变性。通过在 14 至 45 天龄（P14-P45）的 RCS 大鼠中用高分子量荧光素异硫氰酸酯标记的葡聚糖进行灌注，将其与相应的 Sprague-Dawley 大鼠进行比较，从而可视化视网膜毛细血管网络。分析了中央区域到周边视网膜偏心度的血管串扰。通过免疫组织化学、western blot 和定量实时聚合酶链反应分析了血管生长相关因子及其受体在异常血管发育过程中的表达，即血管内皮生长因子（VEGF）、VEGF 受体亚型 1（VEGF-R1）和 -2（VEGF-R2）、生长抑素（SRIF）、生长抑素受体亚型 2（Sstr-2）、血管生成素-2（Ang-2）和酪氨酸激酶免疫球蛋白样和表皮生长因子样结构域 2（Tie-2）。在 RCS 大鼠的中周边视网膜偏心度中发现了未毛细血管化的灌注不足区域，直到 P29 才出现。在血管化过程中，以前灌注不足的区域完全灌注，但具有明显增加的新生血管。Western blot 显示了在毛细血管发育过程中生长相关因子及其受体的特异性表达。在 RCS 大鼠中，VEGF 直到 P29 才显著增加，而在 SD 大鼠中，SRIF 在蛋白质组学水平上在 P21 和 P29 时显著上调。在 RCS 大鼠中，Ang-2 在 P29 时显著上调，而在 P36 时，VEGF-R1 和 VEGF-R2 以及在 P36 时，SRIF 在 mRNA 水平上显著上调。初始不完全灌注后，出现异常血管形成。VEGF、SRIF、Ang-2 及其受体在蛋白质和 mRNA 水平上受到调节，为治疗疾病过程中的缺血性增生性视网膜病变提供了治疗可能性。
