Endo A, Nagai N, Urano T, Ihara H, Takada Y, Hashimoto K, Takada A
Department of Dentistry and Oral and Maxilloralfacial Surgery, Hamamatsu University School of Medicine, Japan.
Neurosci Lett. 1998 Apr 17;246(1):37-40. doi: 10.1016/s0304-3940(98)00204-3.
Tissue-type plasminogen activator (tPA), a serine protease which converts the zymogen plasminogen to the active protease plasmin, is believed to regulate neurite extension and neural cell migration by modulating extracellular metabolism. The highly polysialylated form of the neural cell adhesion molecule (NCAM-H) is strongly expressed in the developing brain and is believed to play a role in organizing the neural network. In this report, we incubated neonatal rat brain homogenates with human tPA and rat plasminogen in order to determine whether NCAM-H would be degraded. NCAM-H was degraded by plasmin which was formed from rat plasminogen by human tPA. The degradation was inhibited by the addition of plasminogen activator inhibitor type 1 (PAI-1) or aprotinin. These results suggest a possible contribution of the tPA-plasmin system to NCAM-H turnover in the developing brain.
组织型纤溶酶原激活剂（tPA）是一种丝氨酸蛋白酶，可将纤溶酶原酶原转化为活性蛋白酶纤溶酶，据信它通过调节细胞外代谢来调节神经突延伸和神经细胞迁移。神经细胞粘附分子的高度多聚唾液酸化形式（NCAM-H）在发育中的大脑中强烈表达，据信在神经网络的组织中发挥作用。在本报告中，我们将新生大鼠脑匀浆与人tPA和大鼠纤溶酶原一起孵育，以确定NCAM-H是否会被降解。NCAM-H被由人tPA从大鼠纤溶酶原形成的纤溶酶降解。通过添加1型纤溶酶原激活剂抑制剂（PAI-1）或抑肽酶可抑制这种降解。这些结果表明tPA-纤溶酶系统可能对发育中的大脑中NCAM-H的周转有贡献。
