T2-TrpRS inhibits preretinal neovascularization and enhances physiological vascular regrowth in OIR as assessed by a new method of quantification
T2-TrpRS inhibits preretinal neovascularization and enhances physiological vascular regrowth in OIR as assessed by a new method of quantification
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DOI：
10.1167/iovs.05-1096
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发表时间：
2006-05-01
影响因子：
4.4
通讯作者：
Friedlander, Martin
中科院分区：
文献类型：
--
作者：
Banin, Eyal;Dorrell, Michael I.;Friedlander, Martin
色氨酸tRNA合成酶的羧基末端片段（T2-TrpRS）在体内视网膜发育性新生血管形成过程中表现出有效的血管生成抑制活性。使用氧诱导的视网膜病变（OIR）的小鼠模型测试T2-TrpRS对病理性新血管形成的作用，并与有效的VEGF拮抗剂进行比较。方法. C57 BL/6 J小鼠在出生后第7天（P7）和P12之间短暂暴露于高氧条件（75%O-2），然后返回室内空气。分离视网膜，用isolectin Griffonia simplicifolia染色血管，获得视网膜整体切片图像，并定量血管闭塞面积和视网膜前新生血管形成程度。将该方法与常用的OIR定量方法进行比较，其中在整个眼睛的连续切片中计数前内界膜（ILM）核的数量。为了评估T2-TrpRS的血管抑制活性，在P12时用T2-TrpRS、VEGF适体或单独的媒介物（PBS）玻璃体内注射小鼠，并评估对闭塞面积和对视网膜前新生血管簇形成的影响。结果在小鼠OIR模型中使用基于异凝集素染色的视网膜整体图像的改良的定量方法，我们能够可靠且一致地评估同一标本中的血管闭塞和视网膜前新生血管簇形成。T2-TrpRS表现出有效的血管抑制活性，减少病理性新生血管簇的出现高达90%。令人惊讶的是，T2-TrpRS还增强了闭塞的视网膜血管的生理性血管重建，与PBS注射的眼睛相比，这些区域减少了高达60%。相反，VEGF拮抗剂虽然同样减少视网膜前新生血管簇的形成，但并没有增强闭塞区域的血管重建。在OIR模型中使用快速、可定量的方法来评估T2-TrpRS对视网膜血管生成的影响，证明了定量系统的重要性，该系统允许同时分析药物对血管闭塞以及对视网膜前新生血管形成的影响。使用该方法获得的结果表明，诸如T2-TrpRS的化合物的临床价值增强，其不仅抑制病理性新血管形成，而且促进缺血组织的生理性再血管形成。
A carboxyl-terminal fragment of tryptophan tRNA synthetase (T2-TrpRS) has demonstrated potent angiostatic activity during retinal developmental neovascularization in vivo. The effects of T2-TrpRS on pathologic neovascularization were tested and compared with a potent VEGF antagonist using the mouse model of oxygen-induced retinopathy (OIR). METHODS. C57BL/6J mice were transiently exposed to hyperoxic conditions (75% O-2) between postnatal day 7 (P7) and P12 and then returned to room air. Retinas were isolated, blood vessels stained with isolectin Griffonia simplicifolia, images of retinal whole-mounts acquired, and the area of vascular obliteration and extent of preretinal neovascularization quantified. This method was compared to the commonly used method of OIR quantification in which the number of pre-inner limiting membrane (ILM) nuclei is counted in serial sections of whole eyes. To assess the angiostatic activity of T2-TrpRS, mice were injected intravitreally at P12 with either T2-TrpRS, a VEGF aptamer, or vehicle (PBS) alone, and the effects on area of obliteration and on preretinal neovascular tuft formation were assessed. RESULTS. Using a modified method of quantification in the mouse OIR model based on images of isolectin-stained retinal wholemounts, we were able to assess reliably and consistently both vascular obliteration and preretinal neovascular tuft formation in the same specimen. T2-TrpRS demonstrated potent angiostatic activity, reducing the appearance of pathologic neovascular tufts by up to 90%. Surprisingly, T2-TrpRS also enhanced physiological revascularization of the obliterated retinal vasculature, reducing these areas by up to 60% compared with PBS-injected eyes. In contrast, the VEGF antagonist, while similarly reducing preretinal neovascular tuft formation, did not enhance revascularization of the obliterated areas.CONCLUSIONS. Use of a rapid, quantifiable method to assess the effect of T2-TrpRS on retinal angiogenesis in the OIR model demonstrates the importance of a quantification system that permits simultaneous analysis of a drug's effect on vascular obliteration as well as on preretinal neovascularization. The results obtained using this method suggest enhanced clinical value for compounds such as T2-TrpRS that not only inhibit pathologic neovascularization, but also facilitate physiological revascularization of ischemic tissue.