Role of Claudin-5 in the Attenuation of Murine Acute Lung Injury by Simvastatin
Role of Claudin-5 in the Attenuation of Murine Acute Lung Injury by Simvastatin
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DOI：
10.1165/rcmb.2013-0058oc
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发表时间：
2014-02-01
影响因子：
6.4
通讯作者：
Jacobson, Jeffrey R.
中科院分区：
文献类型：
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作者：
Chen, Weiguo;Sharma, Rajesh;Jacobson, Jeffrey R.
他汀类药物现在被认为具有多效性，包括增强内皮屏障功能。为了探索其中的机制，我们研究了辛伐他汀对内皮细胞（EC）紧密连接的影响。用辛伐他汀（5 μ M）治疗的人肺动脉内皮细胞的Western blotting证实，与对照组相比，claudin-5蛋白表达明显的时间依赖性增加（16-48 h），而闭塞带-1或occludin没有检测到改变。这些作用与VE-cadherin的膜易位有关，而血管内皮cadherin （VE-cadherin；沉默RNA）的易位抑制辛伐他汀诱导的cladin -5上调。此外，辛伐他汀治疗ECs诱导fox01和β -catenin磷酸化增加，后者是由VE-cadherin介导的cladin -5表达的转录调节因子。随后，我们发现cludin -5沉默对辛伐他汀响应凝血酶刺激的EC屏障保护没有影响，这是通过经内皮电阻或fitc -葡聚糖EC单层通量（2,000 kD）来测量的。然而，通过荧光素钠单层通量（376 Da）测量，cludin -5的沉默确实显著减弱了辛伐他汀介导的EC对凝血酶的屏障保护作用。最后，采用lps诱导的小鼠急性肺损伤模型，体内claudin-5沉默（气管内注射）对支气管肺泡灌洗液蛋白或细胞计数没有影响，但与辛伐他汀处理的对照动物相比，claudin-5沉默的动物lps诱导的肺组织外渗小分子标记物荧光素钠和Hochst染色（562 Da）显著增加。这些发现暗示了他汀类药物具有大小选择性内皮屏障保护特性的独特机制，并可能最终为急性肺损伤患者提供新的治疗靶点。
The statins are now recognized to have pleiotropic properties, including augmentation of endothelial barrier function. To explore the mechanisms involved, we investigated the effect of simvastatin on endothelial cell (EC) tight junctions. Western blotting of human pulmonary artery ECs treated with simvastatin (5 mu M) confirmed a significant time-dependent increase (16-48 h) in claudin-5 protein expression compared with controls, without detectable alterations in zonula occludens-1 or occludin. These effects were associated with membrane translocation of VE-cadherin, whereas translocation of vascular endothelial cadherin (VE-cadherin; silencing RNA) inhibited simvastatin-induced claudin-5 up-regulation. Moreover, simvastatin treatment of ECs induced increased phosphorylation of both FoxO1 and beta-catenin, transcriptional regulators of claudin-5 expression mediated by VE-cadherin. Subsequently, we found no effect of claudin-5 silencing on EC barrier protection by simvastatin in response to thrombin stimulation, as measured by either transendothelial electrical resistance or by EC monolayer flux of FITC-dextran (2,000 kD). However, silencing of claudin-5 did significantly attenuate simvastatin-mediated EC barrier protection in response to thrombin, as measured by monolayer flux of sodium fluorescein (376 Da). Finally, employing a murine model of LPS-induced acute lung injury, there was no effect of claudin-5 silencing in vivo (intratracheal injection) on bronchoalveolar lavage fluid protein or cell counts, but LPS-induced lung tissue extravasation of the small molecular weight markers, sodium fluorescein and Hochst stain (562 Da), were significantly increased in claudin-5-silenced animals compared with simvastatin-treated control animals. These findings implicate a distinct mechanism underlying size-selective endothelial barrier-protective properties of statins, and may ultimately lead to new novel therapeutic targets for patients with acute lung injury.