Human glioma U-251 cells contain type 1 plasminogen activator inhibitor in a rapidly releasable form.
Human glioma U-251 cells contain type 1 plasminogen activator inhibitor in a rapidly releasable form.
复制标题
人神经胶质瘤 U-251 细胞含有快速释放形式的 1 型纤溶酶原激活剂抑制剂。
DOI：
10.1016/0014-5793(96)00865-4
复制
发表时间：
1996
期刊：
影响因子：
3.5
通讯作者：
Schleef,RR
中科院分区：
文献类型：
--
作者：
Salonen,EM;Gombau,L;Engvall,E;Schleef,RR
由于最近的信息表明，蛋白酶抑制剂的局部沉积是一种机制，细胞调节细胞周围的蛋白质水解在组织入侵，1型纤溶酶原激活物抑制剂（派-1）的分布与侵袭性的人胶质瘤细胞系U-251进行了研究。直接和反向纤维蛋白酶谱表明，在U-251条件培养基和细胞裂解液中存在尿激酶样纤溶酶原激活剂（u-PA）和派-1。派-1抗原免疫检测U-251细胞的细胞突起内存在的细胞质颗粒，这些细胞器可以分离Percoll密度梯度在一个高密度带。相比之下，u-PA活性和另一种分泌蛋白，淀粉样β蛋白前体，仅存在于梯度的低密度区域。高密度级分中所含颗粒中派-1的功能分析揭示了活性派-1的存在。U-251细胞与促分泌素8-溴腺苷3′：5′-环一磷酸孵育，导致这些细胞条件培养基中派-1的释放增加3倍。这些数据表明，人神经胶质瘤细胞系U-251含有派-1的快速释放的形式，这可能提供了另一种机制，这些肿瘤可以调节蛋白水解活性在一个本地化的方式。
Because recent information suggests that the localized deposition of protease inhibitors is one mechanism by which cells regulate pericellular proteolysis during tissue invasion, the distribution of type 1 plasminogen activator inhibitor (PAI-1) associated with the invasive human glioma cell line U-251 was investigated. Direct and reverse fibrin zymography indicated the presence of urokinase-like plasminogen activator (u-PA) and PAI-1 in U-251 conditioned media and cell lysates. PAI-1 antigen was detected immunologically in cytoplasmic granules present within cellular processes of U-251 cells and these organelles could be isolated on Percoll density gradients in a high density band. In contrast, u-PA activity and another secreted protein, amyloid β-protein precursor, were only present in the low density region of the gradients. Functional analysis of PAI-1 in the granules contained within the high density fractions revealed the presence of active PAI-1. Incubation of U-251 cells with the secretagogue, 8-bromoadenosine 3′:5′-cyclic monophosphate, resulted in a 3-fold increase in the release of PAI-1 in the media conditioned by these cells. These data suggest that the human glioma cell line U-251 contains PAI-1 in a rapidly releasable form, which may provide another mechanism by which these tumors could regulate proteolytic activity in a localized manner.