MicroRNAs are dynamically regulated and play an important role in LPS-induced lung injury
MicroRNAs are dynamically regulated and play an important role in LPS-induced lung injury
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DOI：
10.1139/y11-095
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发表时间：
2012-01-01
影响因子：
2.1
通讯作者：
Xu, Xiao-Ping
中科院分区：
文献类型：
--
作者：
Cai, Zhi-Gang;Zhang, Shao-Ming;Xu, Xiao-Ping
急性肺损伤以炎性反应增加和严重的肺水肿为特征。即使在鉴定急性肺损伤相关基因和信号通路方面取得了很大进展，但急性肺损伤启动和传播的基本机制尚未完全了解。越来越多的证据表明microRNAs（miRNAs）参与了多种人类疾病。然而，miRNAs在急性肺损伤中的表达谱和功能尚未研究。在这里，使用实时聚合酶链反应分析，我们表明，收集的miRNA是动态调节脂多糖（LPS）诱导的小鼠急性肺损伤。其中miR-199 a和miR-16是下调最显著的miRNAs。为了研究miR-199 a和miR-16在急性肺损伤中的作用，在LPS处理的A549细胞中进行miR-199 a或miR-16的过表达测定，然后分析炎性因子的表达。过表达miR-199 a不能改变IL-6和TNF-α的表达水平，而上调miR-16可显著下调IL-6和TNF-α的表达水平。使用生物信息学分析，我们表明IL-6和TNF α的3'非翻译区（UTR）含有miR-16的结合位点。因此，过表达miR-16可显著抑制与TNF α 3' UTR区结合位点融合的报告基因的荧光素酶活性，提示miR-16在LPS诱导的肺部炎症中以直接方式发挥作用。在这项研究中，我们第一次表明，miRNAs是动态调节的，并在LPS诱导的肺损伤中发挥重要作用。
Acute lung injury is characterized by an increase of inflammatory reaction and severe lung edema. Even if there have been great advances in the identification of genes and signaling pathways involved in acute lung injury, the fundamental mechanisms of initiation and propagation of acute lung injury have not been understood completely. A growing amount of evidence indicates that microRNAs (miRNAs) are involved in various human diseases. However, the expression profile and function of miRNAs in acute lung injury have not been investigated. Here, using real-time polymerase chain reaction analysis, we show that a collection of miRNAs is dynamically regulated in lipopolysaccharide (LPS)-induced mouse acute lung injury. Among them, miR-199a and miR-16 are the most significantly down-regulated miRNAs. To study the role of miR-199a and miR-16 in acute lung injury, an over-expression of miR-199a or miR-16 assay was performed in LPS-treated A549 cells, and then the expression of inflammatory factors was analyzed. Over-expression of miR-199a could not alter the expression level of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF alpha), while up-regulation of miR-16 could significantly down-regulate IL-6 and TNF alpha expression level. Using bioinformatic analysis, we show that a 3' untranslational region (UTR) of IL-6 and TNF alpha contains the binding sites of miR-16. Accordingly, over-expression of miR-16 could significantly suppress the luciferase activity of reporter fusion with the binding sites of TNF alpha in its 3' UTR region, suggesting that miR-16 played its role in LPS-induced lung inflammation by a direct manner. In this study, we show for the first time that miRNAs are dynamically regulated and play an important function in LPS-induced lung injury.