Galicia J C, Naqvi A R, Ko C-C, Nares S, Khan A A
Department of Endodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC, USA.
Department of Periodontics, College of Dentistry, University of Illinois, Chicago, IL, USA.
Genes Immun. 2014 Jul-Aug;15(5):333-7. doi: 10.1038/gene.2014.24. Epub 2014 May 22.
MicroRNAs (miRNAs) regulate the synthesis of cytokines in response to Toll-like receptor (TLR) activation. Our recent microarray study comparing normal and inflamed human dental pulps showed that miRNA-181 (miR-181) family is differentially expressed in the presence of inflammation. Prior studies have reported that the dental pulp, which is composed primarily of TLR4/2+ fibroblasts, expresses elevated levels of cytokines including interleukin-8 (IL-8) when inflamed. In this study, we employed an in-vitro model to determine the role of the miRNA-181 family in the TLR agonist-induced response in human fibroblasts. TLR4/2+ primary human dental pulp fibroblasts were stimulated with lipopolysaccharide from Porphyromonas gingivalis (Pg LPS), a known oral pathogen, and IL-8 and miR-181 expression measured. An inversely proportional relationship between IL-8 and miR-181a was observed. In-silico analysis identified a miR-181a-binding site on the 3' untranslated region (UTR) of IL-8, which was confirmed by dual-luciferase assays. MiR-181a directly binds to the 3'UTR of IL-8, an important inflammatory component of the immune response, and modulates its levels. This is the very first report demonstrating miR-181a regulation of IL-8.
微小RNA（miRNA）可调节细胞因子的合成以响应Toll样受体（TLR）激活。我们最近一项比较正常和发炎人牙髓的微阵列研究表明，miRNA - 181（miR - 181）家族在炎症存在时差异表达。先前的研究报道，主要由TLR4/2 +成纤维细胞组成的牙髓在发炎时会表达升高水平的细胞因子，包括白细胞介素 - 8（IL - 8）。在本研究中，我们采用体外模型来确定miRNA - 181家族在人成纤维细胞中TLR激动剂诱导反应中的作用。用已知口腔病原体牙龈卟啉单胞菌的脂多糖（Pg LPS）刺激TLR4/2 +原代人牙髓成纤维细胞，并测量IL - 8和miR - 181的表达。观察到IL - 8与miR - 181a之间呈反比关系。计算机分析在IL - 8的3'非翻译区（UTR）鉴定出一个miR - 181a结合位点，双荧光素酶测定证实了这一点。MiR - 181a直接与免疫反应的重要炎症成分IL - 8的3'UTR结合，并调节其水平。这是首次证明miR - 181a对IL - 8有调节作用的报告。
