Caveolin-1 regulates the expression of tight junction proteins during hyperoxia-induced pulmonary epithelial barrier breakdown.
Caveolin-1 regulates the expression of tight junction proteins during hyperoxia-induced pulmonary epithelial barrier breakdown.
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Caveolin-1 在高氧诱导的肺上皮屏障破坏过程中调节紧密连接蛋白的表达
DOI：
10.1186/s12931-016-0364-1
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发表时间：
2016-05-12
影响因子：
5.8
通讯作者：
Fu J
中科院分区：
文献类型：
--
作者：
Xu S;Xue X;You K;Fu J
支气管肺发育不良（BPD）是早产儿常见的并发症，涉及紧密连接（TJ）蛋白的下调。然而，在高氧诱导的BPD的早期阶段，TJ蛋白的表达下调的机制仍有待了解。在这里，我们的目的是确定小窝蛋白-1（Cav-1）在高氧诱导的肺上皮屏障破坏中的作用。首先，我们利用新生大鼠原代肺泡Ⅱ型上皮细胞（AEC-Ⅱ）建立了体外肺上皮屏障模型。AEC-II被指定为高氧（85%O2/5%CO2）或常氧（21%O2/5%CO2）组。第二，在常氧暴露下用Cav-1-siRNA转染AEC-II以下调Cav-1。第三，用编码Cav-1的cDNA转染AEC-II以在高氧暴露下上调Cav-1表达。然后，Cav-1和TJ蛋白的表达水平通过免疫荧光染色，逆转录-聚合酶链反应，和蛋白质印迹检测。使用透射电子显微镜观察TJ结构，并测量作为屏障功能指标的异硫氰酸荧光素-葡聚糖的跨上皮阻力和表观渗透系数。我们的数据表明，暴露于高氧破坏肺上皮屏障的结构和功能，并降低ZO-1，occludin，claudin-4和Cav-1的表达水平。此外，在常氧暴露下，Cav-1敲低减弱了其他三个基因的表达，并破坏了肺上皮屏障的结构和功能。然而，Cav-1上调明显拮抗高氧诱导的肺上皮屏障破坏和TJ蛋白丢失。这是第一项研究，目前的证据表明，新的作用，Cav-1下调介导的TJ蛋白损失在肺上皮屏障破坏BPD。本文的在线版本（doi：10.1186/s12931-016-0364-1）包含补充材料，可供授权用户使用。
Bronchopulmonary dysplasia (BPD) is a common complication in preterm infants that involves the downregulation of tight junction (TJ) proteins. However, the mechanism underlying downregulation of the expression of TJ proteins during at the early stages of hyperoxia-induced BPD remains to be understood. Here, we aimed to identify the role of caveolin-1 (Cav-1) in hyperoxia-induced pulmonary epithelial barrier breakdown. First, we established an in vitro pulmonary epithelial barrier models using primary type II alveolar epithelial cells (AEC-II) from newborn rats. AEC-II was assigned to the hyperoxic (85 % O2/5 % CO2) or normoxic (21 % O2/5 % CO2) groups. Second, AEC-II was transfected with Cav-1-siRNA to downregulate Cav-1 under normoxic exposure. Third, AEC-II was transfected with a cDNA encoding Cav-1 to upregulate Cav-1 expression under hyperoxic exposure. Then, expression levels of Cav-1 and TJ proteins were examined by immunofluorescence staining, reverse transcription-polymerase chain reaction, and Western blotting. The TJ structures visualized using a transmission electron microscope, and transepithelial resistance and apparent permeability coefficient of fluorescein isothiocyanate–dextran, which are indicators of barrier function, were measured. Our data showed that exposure to hyperoxia disrupted the structure and function of the pulmonary epithelial barrier and decreased the ZO-1, occludin, claudin-4, and Cav-1 expression levels. Moreover, Cav-1 knockdown attenuated the expression of the other three genes and disrupted pulmonary epithelial barrier structure and function under normoxic exposure. However, Cav-1 upregulation markedly antagonized the hyperoxia-induced pulmonary epithelial barrier destruction and TJ protein loss. This is the first study to present evidence illustrating the novel role of Cav-1 downregulation-mediated TJ protein loss in pulmonary epithelial barrier destruction during BPD. The online version of this article (doi:10.1186/s12931-016-0364-1) contains supplementary material, which is available to authorized users.