Study On The MicroRNA Expression Profiles Of U251Cells Infected By Japanese Encephalitis Virus

Japanese encephalitis virus (JEV), a member of flaviviridae, is a severe pathogen of zoonotic infectious diseases. The virus could cause serious damage to human being through invading central nervous system after infection of human being, causing the patient dead or sufferring from serious neural sequelae. At the same time JEV can infects swine, resulting in breeding obstacle, leading to significant economic losses in swine industry. As an important way of the post-transcription gene regulatory mechanism, miRNA takes part in a wide range of life processes, including growth, differentiation, apoptosis and metabolism. MiRNA also plays an important role in viral entry and the antiviral response in the host cells. But no report is available about the cellular miRNA profile induced by JEV.In this study, total RNAs from JEV P3strain and SA14-14-2strain infected U251cells were extracted and then subjected to solexa sequencing. Compared with control,161miRNAs were differentially expressed upon JEV P3strain infection while175miRNAs were differentially expressed upon JEV SA14-14-2infection. Compared with SA14-14-2infection,76miRNAs were differentially expressed upon JEV P3infection. Further validation of some of the differentially expressed miRNAs was done by real time PCR.miR-487b was up-regulated significantly upon JEV P3infection in U251cells.miR-487b was bioinformatically predicted to target NS3gene of viral genomic RNA,and the MREs were conserved to some extent.furthermore,this prediction was validated by dual luciferase reporter system.viral mRNA and proteins were down regulated when synthetic miR-487b mimics were transfected into the cells.this results indicate that miR-487b could be useful for miRNA-mediated antiviral therapeutic strategies.