Feedback Mechanism Between Blood Vessels and Astrocytes in Retinal Vascular development☆

To meet tissue requirements for oxygen, blood vessels are efficiently distributed throughout the body. Multiple interactions between the vasculature and surrounding tissues are involved in this process. Retinal vascular development is controlled by interactions between ganglion cells, astrocytes, and endothelial cells. In particular, reciprocal feedback between endothelial cells and astrocytes is crucial for proper vascular patterning. Hypoxia-induced vascular endothelial growth factor expression in astrocytes plays a key role in retinal vascular growth. Recently, leukemia inhibitory factor secreted from endothelial cells was shown to act cooperatively with oxygen as a negative feedback signal. This reciprocal feedback mechanism provides a promising target for novel antiangiogenic strategies against ocular neovascular diseases and cancers. Here, we briefly review what is currently known about the molecular events involved in the cellular interactions between ganglion cells, astrocytes, and endothelial cells that control retinal vascular patterning.