Angiogenic potential of neural stem cells

神经干细胞(NSCs)是一种未分化的细胞，既能自我更新又能产生神经元和神经胶质细胞。它们存在于发育中的和成人中枢神经系统的不同区域。我们已经证明，神经干细胞在体外既可以分化为内皮细胞，也可以分化为平滑肌细胞。从胚胎12.5天(E12.5)小鼠大脑皮质分离培养神经干细胞，在含20 ng/ml碱性成纤维细胞生长因子(BFGF)的无血清培养液中形成神经球进行培养。将神经干细胞接种于含10%胎牛血清和碱性成纤维细胞生长因子的胶原凝胶中，培养10天，观察神经干细胞是否形成血管管样结构。凝胶内可见由PECAM-1或VE-钙粘素免疫反应阳性细胞组成的血管管样结构。偶见大量α-平滑肌肌动蛋白免疫反应细胞或胶质纤维酸性蛋白免疫反应细胞包被形成的血管管样结构。这些结果表明，神经干细胞在体外具有形成血管管的潜力，可能在脑血管生成中也是如此。

Neural stem cells (NSCs) are undifferentiated cells capable of both self-renewal and producing neurons and glial cells. They exist in various regions of the developing and adult central nervous system. We have shown that NSCs give rise to both endothelial cells and smooth muscle cells in vitro. NSCs were isolated from mouse embryonic day 12.5 (E12.5) cortex and cultured by neurosphere formation in serum-free medium in the presence of 20 ng/ml basic fibroblast growth factor (bFGF). To examine whether NSCs form vascular tube-like structures, NSCs were inoculated in collagen gels with 10% fetal bovine serum plus bFGF and incubated for 10 days. Vascular tube-like structures consisting of PECAM-1-or VE-cadherin-immunoreactive cells were formed in the gels. Moreover, the formation of vascular tube-like structures with massive investment of α-smooth muscle actin-immunoreactive or GFAP-immunoreactive cells was occasionally observed. These results suggested that NSCs have a potential to form vascular tubes in vitro and perhaps in cerebral angiogenesis as well.