Role of RNA-binding protein HuR and CUGBP1 in LPS-induced Interleukin-6 Expression in Macrophages

Interleukin 6 (IL6) is an important proinflammatory cytokine involved in the pathogenesis of many inflammatory diseases. RNA-binding proteins, HuR and CUGBP1, regulate the mRNA stability and protein translation through direct binding to the AU-rich domain or CUG repeats in the 3 untranslated region (3 UTR) of target genes. However, the exact role of HuR and CUGBP1 in LPS-induced IL6 expression remains unknown. The current study examined the potential role of HuR and CUGBP1 in posttranscriptional regulation of IL6 expression during LPS-mediated inflammatory response in macrophages. MethodsMouse macrophages were used in this study. The IL6 mRNA and protein levels were determined by real time RT-PCR and ELISA, respectively. Protein levels of HuR and CUGBP1 were determined by Western blot analysis. The interaction between RNA binding proteins and IL6 mRNA was identified by pull-down assay and immunoprecipitation. ResultsLPS increased cytosolic HuR and CUGBP1 protein levels and the binding of HuR and CUGBP1 to...