microRNA-196b alleviates lipopolysaccharide-induced inflammatory injury by targeting NRAS.

Bovine endometritis is a serious hazard to husbandry, so it is necessary to know the mechanism of endometritis. In past research, we found microRNAs (miRNAs) might be regulators in inflammation, including miR-196b, but the mechanism of miR-196b in bovine endometritis was unknown. Therefore, we tended to find out what role miR-196b would play in bovine endometritis. As a result, we found miR-196b up-regulated in the endometritis tissue and the high concentration lipopolysaccharide (LPS)-stimulated bovine endometrial epithelial (BEND) cell line, but down-regulated in the low concentration. And, over-expression of miR-196b inhibited the expressions of some inflammatory factors, such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and neuroblastoma RAS (NRAS)/nuclear factor (NF)-κB pathway proteins. Furthermore, the dual-luciferase reporter assay and NRAS knockdown confirmed that miR-196b inhibited activation of the downstream pathway by directly targeting NRAS. In conclusion, we provide evidence that miR-196b alleviates LPS-induced inflammatory injury by targeting NRAS.