Department of Cardio-Thoracic Surgery, Number 455 Hospital of The Chinese People's Liberation Army, Shanghai 200052, China.
Can J Physiol Pharmacol. 2012 Jan;90(1):37-43. doi: 10.1139/y11-095. Epub 2011 Dec 20.
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 (TNFα), while up-regulation of miR-16 could significantly down-regulate IL-6 and TNFα expression level. Using bioinformatic analysis, we show that a 3' untranslational region (UTR) of IL-6 and TNFα 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 TNFα 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.
急性肺损伤的特征是炎症反应增加和严重肺水肿。即使在鉴定涉及急性肺损伤的基因和信号通路方面取得了重大进展，但急性肺损伤的起始和传播的基本机制仍未完全理解。越来越多的证据表明 microRNAs (miRNAs) 参与了各种人类疾病。然而，miRNAs 在急性肺损伤中的表达谱和功能尚未被研究过。在这里，我们使用实时聚合酶链反应分析显示，一组 miRNAs 在脂多糖 (LPS) 诱导的小鼠急性肺损伤中是动态调节的。其中，miR-199a 和 miR-16 是下调最显著的 miRNAs。为了研究 miR-199a 和 miR-16 在急性肺损伤中的作用，在 LPS 处理的 A549 细胞中进行了 miR-199a 或 miR-16 的过表达实验，然后分析了炎症因子的表达。miR-199a 的过表达不能改变白细胞介素 (IL)-6 和肿瘤坏死因子-α (TNFα) 的表达水平，而 miR-16 的上调可以显著下调 IL-6 和 TNFα 的表达水平。通过生物信息学分析，我们显示 IL-6 和 TNFα 的 3'非翻译区 (UTR) 包含 miR-16 的结合位点。因此，miR-16 的过表达可以显著抑制与 TNFα 3'UTR 区域结合位点融合的报告基因的荧光素酶活性，这表明 miR-16 通过直接方式在 LPS 诱导的肺炎症中发挥作用。在这项研究中，我们首次表明 miRNAs 是动态调节的，并在 LPS 诱导的肺损伤中发挥重要作用。
