Tumor necrosis factor/cachectin increases permeability of endothelial cell monolayers by a mechanism involving regulatory G proteins.
Tumor necrosis factor/cachectin increases permeability of endothelial cell monolayers by a mechanism involving regulatory G proteins.
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DOI：
10.1084/jem.169.6.1977
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发表时间：
1989-06-01
期刊：
影响因子：
--
通讯作者：
Stern D
中科院分区：
文献类型：
--
作者：
Brett J;Gerlach H;Nawroth P;Steinberg S;Godman G;Stern D
内皮素是肿瘤坏死因子/恶病质素（TNF）的重要靶点，肿瘤坏死因子/恶病质素是内毒素血症和革兰氏阴性脓毒症中宿主反应的中心介质。在这份报告中，显示TNF通过涉及百日咳毒素敏感性调节G蛋白的机制增加内皮细胞单层对大分子和低分子量溶质的渗透性。暴露于TNF（5 nM）1-3小时内，细胞形状/细胞骨架发生变化，导致单层连续性被破坏，并形成细胞间间隙。与这些结构变化相关的是内皮细胞对大分子和低分子量示踪剂的渗透性增加;在向培养物中加入TNF后，观察到这些示踪剂通过的时间依赖性、可逆性增加，在1-3 h时明显。TNF对屏障功能的干扰也取决于加入的TNF剂量，约为0.4 nM的半数最大值。仅需要TNF短暂暴露于内皮（15分钟）即可诱导通透性增加，放线菌酮或放线菌素D的存在并不能阻止这种增加。与百日咳毒素的单层细胞预孵育平行TNF诱导的增加通过溶质和细胞形状/细胞骨架扰动，表明这些内皮细胞功能的变化之间的密切相关性。与此相反，百日咳毒素没有改变TNF诱导的两个内皮细胞凝血性能的调制。这些数据提供了两个细胞内的TNF作用途径，百日咳毒素可区分的证据，并提供了一个潜在的机制，从TNF介导的血管内空间的溶质损失的洞察：内皮细胞屏障功能的改变。
Endothelium is an important target of tumor necrosis factor/cachectin (TNF), a central mediator of the host response in endotoxemia and Gram- negative sepsis. In this report, TNF is shown to increase the permeability of endothelial cell monolayers to macromolecules and lower molecular weight solutes by a mechanism involving a pertussis toxin- sensitive regulatory G protein. Within 1-3 h of exposure to TNF (5 nM), changes in cell shape/cytoskeleton occurred that led to disruption of monolayer continuity with the formation of intercellular gaps. Correlated with these structural changes was an increase in endothelial permeability to macromolecular and lower molecular weight tracers; time- dependent, reversible increases in passage of these tracers, evident by 1-3 h, were observed after addition of TNF to cultures. Perturbation of barrier function by TNF also depended on the dose of TNF added being half-maximal by approximately 0.4 nM. Only a brief exposure (15 min) of TNF to endothelium was required to induce an increase in permeability, and this was not prevented by the presence of cycloheximide or actinomycin D. Preincubation of monolayers with pertussis toxin blocked in parallel TNF-induced increased passage of solutes and cell shape/cytoskeletal perturbation, indicating the close correlation between these changes in endothelial cell function. In contrast, pertussis toxin did not alter TNF-induced modulation of two endothelial cell coagulant properties. These data provide evidence for two intracellular pathways of TNF action that are distinguishable by pertussis toxin and provide insight into a mechanism underlying loss of solute from the intravascular space mediated by TNF: alteration in endothelial cell barrier function.