Regulation of actin dynamics is critical for endothelial barrier functions
Regulation of actin dynamics is critical for endothelial barrier functions
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DOI：
10.1152/ajpheart.00687.2004
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发表时间：
2005-03-01
影响因子：
4.8
通讯作者：
Drenckhahn, D
中科院分区：
文献类型：
--
作者：
Waschke, J;Curry, FE;Drenckhahn, D
肌动蛋白动力学的调节对于内皮屏障功能至关重要。 Am J Physiol Heart Circ Physiol 288：H1296-H1305，2005。首次发表于 2004 年 11 月 4 日； doi:10.1152/ajpheart.00687.2004.-我们测试了这样的假设：内皮细胞中 F- 和 G-肌动蛋白之间的平衡调节肌动蛋白细胞骨架的完整性，并且对于体内和体外维持内皮屏障功能很重要。我们使用肌动蛋白解聚剂细胞松弛素 D 和 jasplakinolide（一种肌动蛋白丝 (F-actin) 稳定和促进物质）来调节肌动蛋白细胞骨架。我们之前已经证明低剂量的 jasplakinolide (0.1 muM) 可以降低细胞松弛素 D 的通透性增加作用，但对体内单灌注肠系膜微血管的静息通透性以及单层完整性没有影响。培养的内皮细胞的F-肌动蛋白含量保持不变。相反，较高剂量（10 μM）的 jasplakinolide 增加渗透性（水力传导率）的程度与细胞松弛素 D 相同，并诱导培养的心肌内皮 (MyEnd) 单层细胞中细胞间隙的形成。伴随着 MyEnd 细胞中 F-肌动蛋白增加 34% 以及肌动蛋白细胞骨架的明显紊乱。此外，我们测试了毛喉素和咯利普兰增加 cAMP 是否会阻止细胞松弛素 D 诱导的屏障破坏。增加细胞内 cAMP 的条件未能阻止细胞松弛素 D 诱导的体内通透性增加和体外血管内皮钙粘蛋白介导的粘附的减少。总之，这些数据支持这样的假设：肌动蛋白细胞骨架的聚合状态对于维持内皮屏障功能至关重要，并且细胞松弛素 D 的解聚和 jasplakinolide 的肌动蛋白高聚合都会导致体内微血管通透性增加。然而，已知支持内皮屏障功能的 cAMP 似乎通过稳定 F-肌动蛋白以外的机制发挥作用。
Regulation of actin dynamics is critical for endothelial barrier functions. Am J Physiol Heart Circ Physiol 288: H1296-H1305, 2005. First published November 4, 2004; doi:10.1152/ajpheart.00687.2004.-We tested the hypothesis that the equilibrium between F- and G-actin in endothelial cells modulates the integrity of the actin cytoskeleton and is important for the maintenance of endothelial barrier functions in vivo and in vitro. We used the actin-depolymerizing agent cytochalasin D and jasplakinolide, an actin filament (F-actin) stabilizing and promoting substance, to modulate the actin cytoskeleton. Low doses of jasplakinolide (0.1 muM), which we have previously shown to reduce the permeability-increasing effect of cytochalasin D, had no influence on resting permeability of single-perfused mesenteric microvessels in vivo as well as on monolayer integrity. The F- actin content of cultured endothelial cells remained unchanged. In contrast, higher doses (10 muM) of jasplakinolide increased permeability (hydraulic conductivity) to the same extent as cytochalasin D and induced formation of intercellular gaps in cultured myocardial endothelial (MyEnd) cell monolayers. This was accompanied by a 34% increase of F-actin and pronounced disorganization of the actin cytoskeleton in MyEnd cells. Furthermore, we tested whether an increase of cAMP by forskolin and rolipram would prevent the cytochalasin D-induced barrier breakdown. Conditions that increase intracellular cAMP failed to block the cytochalasin D-induced permeability increase in vivo and the reduction of vascular endothelial cadherin-mediated adhesion in vitro. Taken together, these data support the hypothesis that the state of polymerization of the actin cytoskeleton is critical for maintenance of endothelial barrier functions and that both depolymerization by cytochalasin D and hyperpolymerization of actin by jasplakinolide resulted in an increase of microvessel permeability in vivo. However, cAMP, which is known to support endothelial barrier functions, seems to work by mechanisms other than stabilizing F-actin.