血脑屏障——形态、调节和临床意义

Blood-brain barrier-morphology, modulation and clinical implications

血脑屏障为中枢神经系统提供解剖和生理上的保护,防止血细胞和大多数血源性物质进入中枢神经系统。大脑微血管的三种细胞成分(内皮细胞、星形胶质细胞终足和周围细胞)组成了血脑屏障。在大脑内皮细胞之间表达的紧密连接(TJs)形成的弥散屏障是血脑屏障非常重要的组成部分。星形胶质细胞和其他细胞可以调节血脑屏障的通透性,使恰当的化学物质通过。血脑屏障的破坏,比如TJs层的破坏可见于一系列的神经系统疾病,包括卒中、感染、脑肿瘤、多发性硬化和Alzheimer病。我们回顾了最近的文献以帮助我们认识血脑屏障的生理功能及其功能异常和中枢神经系统疾病之间的关系。

The blood-brain barrier （BBB） provides both anatomical and physiological protection for the central nervous system （CNS） , strictly regulating or impeding the entry of many substances and blood-borne ceils into the nervous tissue. Three cellular elements of the brain microvasculature compose the BBB-endothelial ceils, astrocyte end feet, and perivascular ceils （PCs）. Tight junctions （TJs）, present between the cerebral endothelial ceils, form a diffusion barrier, which is a very important part of BBB. The astrocytes and other ceils can release chemical factors that modulate endothelial permeability. Dysfunction of the BBB, for example, impairment of the TJ seal, complicates a number of neurological diseases including stroke, infection, brain tumor, multiple sclerosis and Alzheimer disease. We review here the recent develop- ments in our understanding of the BBB and the role of BBB dysfunction in CNS diseases.