MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 （TLR4） rapidly increased the level of microRNA-124 （miR- ...MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 （TLR4） rapidly increased the level of microRNA-124 （miR- 124） in lipopolysaccharide （LPS）-treated macrophages and mice. MiR-124 knockdown significantly increased the production of the pro-inflammatory cytokine TNF-oL at the post-transcriptional level in LPS-triggered macrophages. Furthermore, miR-124 knockdown or overexpression significanly increased or decreased the protein stability of TNF- α. We found miR-124 directly targeted ubiquitin-specific proteases 2 （USP2） and 14 （USP14）, two components of deubiquitinating enzymes. Knockdown of USP2 and USP14 attenuated the miR-124-mediated protein degradation of TNF-α. Together, our data identify miR-124 as an important feedback negative regulator for LPS-induced pro- duction of TNF-α by targeting USP2 and USP14, thus outlining new mechanisms for fine-tuning the TLR-triggered inflammatory response.展开更多
文摘MicroRNAs play pivotal roles in the regulation of both innate and adaptive immune responses. In this study, we found that activation of toll-like receptor 4 （TLR4） rapidly increased the level of microRNA-124 （miR- 124） in lipopolysaccharide （LPS）-treated macrophages and mice. MiR-124 knockdown significantly increased the production of the pro-inflammatory cytokine TNF-oL at the post-transcriptional level in LPS-triggered macrophages. Furthermore, miR-124 knockdown or overexpression significanly increased or decreased the protein stability of TNF- α. We found miR-124 directly targeted ubiquitin-specific proteases 2 （USP2） and 14 （USP14）, two components of deubiquitinating enzymes. Knockdown of USP2 and USP14 attenuated the miR-124-mediated protein degradation of TNF-α. Together, our data identify miR-124 as an important feedback negative regulator for LPS-induced pro- duction of TNF-α by targeting USP2 and USP14, thus outlining new mechanisms for fine-tuning the TLR-triggered inflammatory response.
