MicroRNA 34a contributes to virus-mediated apoptosis through binding to its target gene Bax in influenza A virus infection.

Abstract Objective Influenza A virus is a cytolytic virus that induces apoptosis in numerous cell types. However, molecular mechanism of cell apoptosis induced by influenza A virus is not well understood. The present study was aimed to investigate the molecular mechanism of miR-34a involved in influenza A virus induced apoptosis. Methods Firstly, microRNA array was used to select miRNAs involved in influenza A virus infection. Then, Luciferase reporter assay and western blot were carried to determine the target gene of miR-34a. Finally, miR-34a mimic was transfected in influenza A virus-infected A549 cells, and western blot was used to test the function of miR-34a and its target gene in in influenza A virus infection. Results miR-34a was found significantly down-regulated in influenza A virus-infected A549 cells and was further confirmed by qRT-PCR in vitro and in vivo (P  Conclusion It is, therefore, concluded that influenza virus infection regulated pro-apoptotic Bax expression through miR-34a downregulation, which might be the partial mechanism of influenza virus-induced cell apoptosis.