Since the pioneering work of Ashton and others, the primate retina has been thought to vascularize by a vasculogenic linkage of endothelial precursor cells. Recent investigations using specific histologic and morphologic criteria question the contribution of vasculogenesis to retinal development. Instead, in primates and mice cells previously designated as retinal angioblasts have been identified as astrocytes that form a vascular-like plexus preceding vessel invasion. Further, in primates and mice retinal vascularization proceeds via angiogenic sprouting from pre-existing vessels in all regions and stages. However, the developing retinal vasculature may utilize novel sources of endothelial cells, such as recruitment of circulating stem cells and redeployment of mural cells from regressing vessel segments. These results provide a framework for study of retinal vascular development, validate the common use of perinatal retinal models in angiogenesis research, and clarify the cellular basis of retinopathy of prematurity.

中文翻译：

---

视网膜血管发育中的细胞机制。

自阿什顿等人的开创性工作以来，人们认为灵长类动物的视网膜通过内皮前体细胞的血管生成连接而血管化。最近使用特定的组织学和形态学标准进行的调查质疑了血管生成对视网膜发育的贡献。取而代之的是，在灵长类动物和小鼠中，先前被称为视网膜血管母细胞的细胞已被鉴定为星形胶质细胞，在血管浸润之前形成了血管样神经丛。此外，在灵长类动物和小鼠中，视网膜血管化是通过所有区域和各个阶段中已有血管的新生血管进行的。但是，发展中的视网膜脉管系统可能利用了内皮细胞的新来源，例如循环干细胞的募集和壁垒细胞从退化的血管节段的重新部署。