内皮细胞对神经干细胞增殖与分化的影响

已经确定神经干细胞在脑中不是随意分布,而是集中在血管周围的。尽管神经干细胞存在于血管周围,但是对于其与血管组成细胞之间的关系还不是很清楚。据报道,内皮细胞释放的可溶性因子可以刺激神经干细胞自我增殖,抑制其分化,并且提高神经元的比例。将内皮细胞与神经干细胞共同培养可以激活Notch途径来促进神经干细胞自我增殖。另外,血管内皮生长因子对神经细胞的生长也起着非常重要的作用,它促进了中枢神经系统星形胶质细胞的生长与分化。因此,内皮细胞不仅是传统意义上血管的组成部分,还是神经干细胞所在区域的重要成分,并且可以通过大脑产生的神经营养性分泌物来提高神经元的发生。

Effects of Endothelial Cells on Renewal and Differentiation of Neural Stem Cells

It is well established that neural stem cells(NSCs) are not randomly distributed throughout the brain,but rather are concentrated around blood vessels.Although NSCs lie in a vascular niche,there is no direct evidence for a functional relationship between the NSCs and blood vessel component cells.It is reported that endothelial cells release soluble factors that stimulate the self-renewal of NSCs,inhibit their differentiation,and enhance their neuron production.Endothelial coculture can activate Notch to promote self-renewal.Furthermore,vascular endothelial growth factor(VEGF) plays a significant role in neural cells;it stimulates the growth and differentiation of astrocytes in the central nervous system(CNS).Therefore,beyond their traditional role as structural components of blood vessels,endothelial cells are not only critical component of the neural stem cell niche,but they also are able to enhance neurogenesis,possibly through the secretion of brain-derived neurotrophic factor.