| 19650740 |
Xiao B, Liu Z, Li BS, Tang B, Li W, Guo G, Shi Y, Wang F, Wu Y, Tong WD, Guo H, Mao XH, Zou QM: Induction of microRNA-155 during Helicobacter pylori infection and its negative regulatory role in the inflammatory response. J Infect Dis. 2009 Sep 15;200(6):916-25.
BACKGROUND: MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression at posttranscriptional level. H. pylori is a major human pathogenic bacterium in gastric mucosa. To date, the role of miRNAs in response to H. pylori infection has not been explored. METHODS: The expression profile of cellular miRNAs during H. pylori infection was analyzed by using microarray and quantitative reverse-transcriptase polymerase chain reaction. The potential target of miR-155 was identified by luciferase assay and Western blot. Promoter analysis and inhibitor experiment were used to investigate the pathway involved in the induction of miR-155. Examination of miR-155 function was performed by overexpression and inhibition of miR-155. RESULTS: H. pylori was able to increase the miR-155 expression in gastric epithelial cell lines and gastric mucosal tissues, and nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) pathway were required for the induction of miR-155. miR-155 may down-regulate IkappaB kinase epsilon, Sma- and Mad-related protein 2 (SMAD2), and Fas-associated death domain protein. Furthermore, the overexpression of miR-155 negatively regulated the release of interleukin-8 and growth-related oncogene-alpha. CONCLUSIONS: This study provides the first description of increased expression of miR-155 in H. pylori infection, and miR-155 may function as novel negative regulator that help to fine-tune the inflammation response of H. pylori infection. |
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