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Oxygen modifies artery differentiation and network morphogenesis in the retinal vasculature
Author(s) -
Claxton Suzanne,
Fruttiger Marcus
Publication year - 2005
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20407
Subject(s) - biology , anatomy , artery , retinal , retinal artery , hypoxia (environmental) , mural cell , oxygen tension , vein , cellular differentiation , blood vessel , vascular smooth muscle , microbiology and biotechnology , medicine , endocrinology , oxygen , smooth muscle , gene , chemistry , botany , biochemistry , organic chemistry
The mechanisms that control differentiation of immature blood vessels into either arteries or veins are not well understood. Because oxygen tension in arteries is higher than in veins, oxygen has the potential to be an instructive signal for artery/vein (AV) differentiation. We test this hypothesis by exposing newborn mice to moderate hypoxia (10% atmospheric oxygen) and studying AV differentiation in the developing retinal vasculature. Forming retinal arteries fail to express the artery‐specific markers Delta‐like 4 (Dll4) and EphrinB2 during hypoxia. However, other aspects of AV differentiation are retained such as high levels of alpha smooth muscle actin in arterial mural cells and vein‐specific expression of the msr/apj gene. The capillary network between arteries and veins is denser, and capillaries expressing the venous marker msr/apj are found in territories normally occupied by arterial capillaries. Thus, it appears that high oxygen in arterial blood is required for arterial expression of Dll4 and EphrinB2, which could be involved in cell–cell repulsion pathways that dictate the normal segregation of arteries and veins. Developmental Dynamics 233:822–828, 2005. © 2005 Wiley‐Liss, Inc.