Astrocyte regulation of human brain capillary endothelial fibrinolysis
Astrocyte regulation of human brain capillary endothelial fibrinolysis
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DOI：
10.1016/j.thromres.2003.10.021
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发表时间：
2003-01-01
影响因子：
7.5
通讯作者：
Fisher, MJ
中科院分区：
文献类型：
--
作者：
Kim, JA;Tran, ND;Fisher, MJ
介绍：星形胶质细胞是已知的调节各种脑内皮细胞的功能。先前的工作，使用混合物种共培养系统，已显示星形胶质细胞调节脑毛细血管内皮表达关键止血因子组织纤溶酶原激活物（tPA）及其抑制剂，纤溶酶原激活物抑制剂-1（派-1）。本研究的目的是明确人星形胶质细胞对人脑毛细血管内皮细胞纤溶的调节作用。材料与方法：我们使用了一个血脑屏障模型，该模型由在transwell膜插入物上生长的人星形胶质细胞组成，并与人脑毛细血管内皮细胞共培养。共培养48小时后，我们分析了内皮单培养物和星形胶质细胞-内皮共培养物的tPA和派-1 mRNA、蛋白质和活性的表达。结果与结论：tPA和派-1 mRNA都有显著变化：与单培养物相比，在共培养物中tPA mRNA水平降低（55 +/-16%的单培养物，p < 0.0005），派-1 mRNA水平增加144 +/-38%（p < 0.005）。共培养物产生tPA蛋白54%的降低（12.7 +/- 3.8对27.5 +/- 7.1 ng/ml，p < 0.005）和派-1蛋白24%的增加（117.5 +/- 3.2对94.9 +/- 5.9 ng/ml，p < 0.0005）。TGF-β中和抗体减弱了观察到的tPA和派-1的变化。这些数据表明，人星形胶质细胞通过抑制tPA和增强派-1表达来调节体外人脑毛细血管纤溶。这种调节部分由转化生长因子β介导。我们的研究结果为星形胶质细胞在脑特异性止血调节中的作用提供了进一步的证据。(C)2003 Elsevier Ltd.保留所有权利。
Introduction: Astrocytes are known to regulate a wide variety of brain endothelial cell functions. Prior work, using a mixed species co-culture system, has shown astrocyte regulation of brain capillary endothelial expression of key hemostasis factors tissue plasminogen activator (tPA) and its inhibitor, plasminogen activator inhibitor-1 (PAI-1). The purpose of this study is to define the fibrinolytic regulatory role of human astrocytes on human brain capillary endothelial cells. Materials and methods: We used a blood-brain barrier model consisting of human astrocytes grown on transwell membrane inserts and co-cultured with human brain capillary endothelial cells. Following 48 h co-culture, we analyzed both endothelial mono-cultures and astrocyte-endothelial co-cultures for expression of tPA and PAI-1 mRNA, protein, and activity. Results and conclusions: There were significant changes for both tPA and PAI-1 mRNA:tPA mRNA levels were decreased in co-cultures (55 +/- 16% of mono-cultures, p < 0.0005) and PAI-1 mRNA levels were increased 144 +/- 38%, compared to mono-cultures (p < 0.005). Co-cultures produced a 54% reduction in tPA protein (12.7 +/- 3.8 vs. 27.5 +/- 7.1 ng/ml, p < 0.005) and a 24% increase in PAI-1 protein (117.5 +/- 3.2 vs. 94.9 +/- 5.9 ng/ml, p < 0.0005). TGF-beta neutralizing antibody attenuated the observed changes in both tPA and PAI-1. These data indicate that human astrocytes regulate human brain capillary fibrinolysis in vitro by inhibiting tPA and enhancing PAI-1 expression. This regulation is mediated, in part, by transforming growth factor-beta. Our findings provide further evidence for the role of astrocytes in brain-specific hemostasis regulation. (C) 2003 Elsevier Ltd. All rights reserved.