Functional differentiation of neural stem cells into smooth muscle cells.

我们已经在中枢神经系统中建立了神经干细胞（NSCs）向平滑肌细胞（SMCs）和内皮细胞的分化。为了研究nsc来源的SMCs是否具有收缩平滑肌（SM）的特征，我们制备了nsc来源的SMCs的重建SM纤维并测量了其收缩张力。纤维在KC1、ACh和内皮素-1的作用下收缩。硝苯地平可部分抑制乙酰胆碱引起的收缩，而MLCK抑制剂ML-9和rho激酶抑制剂Y-27632可完全消除乙酰胆碱引起的收缩，提示SMCs中存在SM收缩机制。为了检验nsc来源的内皮细胞能否在体外形成血管样结构，将分化的细胞接种于含有10%胎牛血清和bFGF的胶原凝胶中，培养5天，凝胶中形成由pecam -1或ve -cadherin免疫反应细胞组成的血管样管结构。此外，偶见α-平滑肌肌动蛋白免疫反应细胞大量投资形成血管管样结构。这些结果表明，NSCs在体外可产生内皮细胞和SMCs两种类型的血管细胞，并具有形成血管管的能力。这些结果提出了一种可能性，即头部血管至少部分来源于NSCs。

We have established the differentiation of neural stem cells (NSCs) in the CNS into smooth muscle cells (SMCs) and endothelial cells. To examine whether NSC-derived SMCs possess a characteristic of contractile smooth muscle (SM), we have prepared a reconstituted SM fiber of NSC-derived SMCs and measured its contractile tension. The fiber contracted in response to KC1, ACh, and endothelin-1. ACh-induced contraction was partially inhibited by nifedipine and completely abolished by the MLCK inhibitor ML-9 and the Rho-kinase inhibitor Y-27632, suggesting that SM contractile mechanisms are present in the SMCs. To examine whether NSC-derived endothelial cells can form a vascular tube-like structure in vitro, the differentiated cells were inoculated in collagen gels with 10% FBS and bFGF and incubated for 5 days, vessel-like tube structures consisting of PECAM-1-or VE-cadherin-immunoreactive cells were formed in the gels. Moreover, the formation of vascular tube-like structures with a massive investment of α-smooth muscle actin-immunoreactive cells was occasionally observed. These results suggested that NSCs give rise to two types of vascular cells, endothelial cells and SMCs in vitro, which have the ability to form vascular tubes. These results arise one possibility that blood vessels in head are at least in part derived from NSCs.