Neisseria meningitidis induces brain microvascular endothelial cell detachment from the matrix and cleavage of occludin: a role for MMP-8.
Neisseria meningitidis induces brain microvascular endothelial cell detachment from the matrix and cleavage of occludin: a role for MMP-8.
复制标题
DOI：
10.1371/journal.ppat.1000874
复制
发表时间：
2010-04-29
期刊：
影响因子：
6.7
通讯作者：
Frosch M
中科院分区：
文献类型：
--
作者：
Schubert-Unkmeir A;Konrad C;Slanina H;Czapek F;Hebling S;Frosch M
血脑屏障（BBB）的破坏是细菌性脑膜炎病理生理学的标志性事件。几种炎症介质，如肿瘤坏死因子α（TNF-α），一氧化氮和基质金属蛋白酶（MMP），有助于这种破坏。在这里，我们表明，感染脑膜炎奈瑟氏菌的人脑微血管内皮细胞（HBMEC）诱导的渗透性增加，在感染时间延长。这被从感染细胞收集的上清液中MMP-8活性的增加所证实。详细的分析显示，MMP-8参与紧密连接蛋白occludin的蛋白水解裂解，导致其从细胞外周消失，并在感染的HBMEC中裂解为较小尺寸的50 kDa蛋白。通过特异性抑制剂消除MMP-8活性以及用MMP-8 siRNA转染消除了切割片段的产生，occludin仍然附着在细胞外周。此外，MMP-8影响细胞与底层基质的粘附。观察到MMP活性和细胞脱离的类似时间关系。HBMEC单层的损伤表明需要直接细胞接触，因为当细菌置于transwell膜上方或当细菌上清液直接加入细胞时，未观察到分离。MMP-8的抑制部分地防止了感染的HBMEC的脱离并恢复了BBB通透性。总之，我们确定MMP-8活性在脑膜炎球菌感染期间细胞连接组分的分解和细胞粘附中起着至关重要的作用。细菌性脑膜炎发病的关键环节是脑微血管内皮功能紊乱，导致血脑屏障（BBB）破坏。基质金属蛋白酶（MMPs）在几项研究中与细菌性脑膜炎的BBB损伤有关。MMP是锌依赖性内肽酶家族，其催化细胞外基质蛋白的蛋白水解，但也可以切割一系列其他分子，包括细胞粘附分子。在这项研究中，我们发现，脑内皮细胞产生MMP-特别是MMP-8-感染脑膜炎奈瑟菌，一种细菌，导致脑膜炎和感染性休克。我们发现MMP-8参与了紧密连接蛋白occludin的破坏。除了MMP-8对紧密连接成分的影响外，MMP-8活性也解释了在N.脑膜炎当我们抑制MMP-8的活性，occludin破坏完全取消和细胞脱离可以部分防止，这导致恢复血脑屏障通透性。我们的数据揭示了脑膜炎球菌性脑膜炎期间细胞功能障碍的分子机制，增强了我们对MMPs如何影响脑内皮功能的理解，并有助于我们理解和预防这种疾病。
Disruption of the blood-brain barrier (BBB) is a hallmark event in the pathophysiology of bacterial meningitis. Several inflammatory mediators, such as tumor necrosis factor alpha (TNF-α), nitric oxide and matrix metalloproteinases (MMPs), contribute to this disruption. Here we show that infection of human brain microvascular endothelial cells (HBMEC) with Neisseria meningitidis induced an increase of permeability at prolonged time of infection. This was paralleled by an increase in MMP-8 activity in supernatants collected from infected cells. A detailed analysis revealed that MMP-8 was involved in the proteolytic cleavage of the tight junction protein occludin, resulting in its disappearance from the cell periphery and cleavage to a lower-sized 50-kDa protein in infected HBMEC. Abrogation of MMP-8 activity by specific inhibitors as well as transfection with MMP-8 siRNA abolished production of the cleavage fragment and occludin remained attached to the cell periphery. In addition, MMP-8 affected cell adherence to the underlying matrix. A similar temporal relationship was observed for MMP activity and cell detachment. Injury of the HBMEC monolayer suggested the requirement of direct cell contact because no detachment was observed when bacteria were placed above a transwell membrane or when bacterial supernatant was directly added to cells. Inhibition of MMP-8 partially prevented detachment of infected HBMEC and restored BBB permeability. Together, we established that MMP-8 activity plays a crucial role in disassembly of cell junction components and cell adhesion during meningococcal infection. A crucial step in the pathogenesis of bacterial meningitis is the disturbance of cerebral microvascular endothelial function, resulting in blood-brain barrier (BBB) breakdown. Matrix metalloproteinases (MMPs) have been implicated in BBB damage in bacterial meningitis in several studies. MMPs are a family of zinc-dependent endopeptidases that catalyze the proteolysis of extracellular matrix proteins, but can also cleave a range of other molecules, including cell adhesion molecules. In this study we showed that brain endothelial cells produced MMPs—in particular MMP-8—upon infection with Neisseria meningitidis, a bacterium that causes meningitis and septic shock. We found that MMP-8 was then involved in disruption of the tight junction protein occludin. In addition to the effect of MMP-8 on the tight junction component, MMP-8 activity also accounted for brain endothelial cell detachment that occurred during prolonged time of infection with N. meningitidis. When we inhibited MMP-8 activity, occludin disruption was completely abolished and cell detachment could be partially prevented, which resulted in restored BBB permeability. Our data reveal a molecular mechanism of cellular dysfunction during meningococcal meningitis that enhances our understanding how MMPs affect cerebral endothelial function and that can aid in our understanding and prevention of this disease.
登录
查看更多内容
DOI：
10.1038/nrmicro1952
发表时间：
2008-08
期刊：
Nature reviews. Microbiology
影响因子：
--
作者：
通讯作者：
--
DOI：
10.1084/jem.187.4.579
发表时间：
1998-02-16
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Levkau B;Herren B;Koyama H;Ross R;Raines EW
通讯作者：
Raines EW
影响因子：
56.9
作者：
Coureuil, Mathieu;Mikaty, Guillain;Nassif, Xavier
通讯作者：
Nassif, Xavier
影响因子：
4.8
作者：
Gorodeski, George I.
通讯作者：
Gorodeski, George I.
影响因子：
2.9
作者：
Lohmann, C;Krischke, M;Galla, HJ
通讯作者：
Galla, HJ