PHALLACIDIN PREVENTS THROMBIN-INDUCED INCREASES IN ENDOTHELIAL PERMEABILITY TO ALBUMIN
PHALLACIDIN PREVENTS THROMBIN-INDUCED INCREASES IN ENDOTHELIAL PERMEABILITY TO ALBUMIN
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DOI：
10.1152/ajpcell.1989.257.3.c562
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发表时间：
1989-09-01
影响因子：
--
通讯作者：
TSAN, MF
中科院分区：
文献类型：
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作者：
PHILLIPS, PG;LUM, H;TSAN, MF
利用在聚碳酸酯过滤器上培养的小牛肺动脉内皮单层来研究125 I标记的白蛋白渗透性和肌动蛋白丝分布对凝血酶挑战的反应。30分钟暴露于α-凝血酶（10-7 M）显著增加白蛋白清除率。这些变化与肌动蛋白丝分布的显著改变有关，导致外周肌动蛋白带的丢失和细胞质应力纤维数量的增加。 由于肌动蛋白周边丝被认为在交界处的稳定性发挥重要作用，我们假设，稳定的肌动蛋白丝应防止凝血酶诱导的屏障破坏。用0.3 μ M 7-硝基苯-2-氧杂-1，3-二唑（NBD）-鬼笔毒肽（一种特异性肌动蛋白稳定剂）预处理细胞，防止肌动蛋白丝分布的变化，并显著减弱白蛋白渗透性的增加。由于鬼笔毒素的潜在毒性，我们评估了预处理对细胞活力和生长参数的影响。与对照相比，用0.3 μ M NBD-鬼笔毒肽处理的细胞的存活率、接种效率或倍增时间没有差异。我们的数据支持的假设，肌动蛋白丝，特别是周边带，有助于显着的屏障功能的维持培养的内皮细胞。
Calf pulmonary artery endothelial monolayers cultured on polycarbonate filters were utilized to study 125I-labeled albumin permeability and actin filament distribution in response to thrombin challenge. Thirty-minute exposure to .alpha.-thrombin (10-7 M) significantly increased albumin clearance rates. These changes were associated with marked alterations in actin filament distribution, resulting in loss of peripheral actin bands and an increase in the number of cytoplasmic stress fibers. Because the actin peripheral filaments are thought to play an important role in junctional stability, we postulated that stabilization of actin filaments should protect against thrombin-induced barrier disruptions. Pretreatment of cells with 0.3 .mu.M 7-nitrobenz-2-oxa-1,3-diazole (NBD)-phallacidin, a specific actin-stabilizing agent, prevented the changes in actin filament distribution and markedly attenuated the increase in albumin permeability. Because of the potential toxicity of phallatoxins, we evaluated the effects of pretreatment on cell viability and growth parameters. There were no differences in viability, seeding efficiency, or doubling times in cells treated with 0.3 .mu.M NBD-phallacidin in comparison to controls. Our data support the hypothesis that actin filaments, particularly peripheral bands, contribute significantly to the maintenance of barrier function in cultured endothelial cells.