Knockdown of miR-155 protects microglia against LPS-induced inflammatory injury via targeting RACK1: A novel research for intracranial infection

Background: intracranial infection,one of the complications of traumatic brain injury,is usually associated with inflammation. several micrornas (mirnas),including mir-155,have been reported to be critical modulators in peripheral and central nervous system inflammation. in this study,we investigated the role of mir-155 in lipopolysaccharide (lps)-induced inflammatory injury in mouse microglia bv2 cells. results: the expression level of mir-155 was significantly up-regulated after lps stimulation in bv2 cells. lps administration decreased bv2 cell viability,promoted apoptosis and increased the release of pro-inflammatory cytokines; while mir-155 knockdown rescued bv2 cell from lps-induced injury. rack1 was a directly target of mir-155. interestingly,mir-155 knockdown did not attenuate lps-induced inflammatory injury when rack1 was knocked down. the mechanistic study indicated that mir-155 knockdown deactivated mapk/nf-κb and mtor signaling pathways under lps-treated conditions. conclusions: knockdown of mir-155 protected mouse microglia bv2 cells from lps-induced inflammatory injury via targeting rack1 and deactivating mapk/nf-κb and mtor signaling pathways. © 2017 the author(s).