期刊
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
卷 280, 期 6, 页码 C1367-C1374出版社
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpcell.2001.280.6.C1367
关键词
angiogenesis; hypoxia; hyperoxia; vessel regression
Development of microvascular networks is set to meet the metabolic requirements of the tissue they perfuse. Accordingly, impairment of oxygen homeostasis, either due to increased oxygen consumption or as a result of blood vessel occlusion, triggers compensatory neovascularization. This feedback reaction is mediated by a hypoxia- and hypoglycemia-induced vascular endothelial growth factor (VEGF). VEGF accumulates under stress as a result of increased hypoxia-inducible factor-1 alpha -mediated transcription, stabilization of the mRNA, and the function of a hypoxia- refractory internal ribosome entry site within its 5'-untranslated region. Matching of vascular density to the metabolic needs of the tissue may include a process of hyperoxia-induced vessel regression. Thus newly formed vascular networks may undergo a natural process of vascular pruning that takes place whenever VEGF, acting as a vascular survival factor, is downregulated below the level required to sustain immature vessels. Immature vessels are particularly vulnerable and are selectively obliterated upon withdrawal of VEGF. The plasticity window for vessel regression is determined by a delay in the recruitment of periendothelial cells to the preformed endothelial plexus. Thus fine-tuning of microvascular density takes place mostly in the newly formed plexus, but the mature system is refractory to episodic changes in tissue oxygenation. These regulatory links may malfunction in certain pathological settings.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据