microRNA-mediated GALNT3 upregulation facilitates mucin production and viral replication in influenza A virus-infected respiratory epithelial cells. Homo sapiens

Viral infections affecting the upper or lower respiratory tract induce mucin production in the epithelial surfaces of the respiratory cells. However, a little is known about how mucins are produced on the surfaces of respiratory epithelial cells and affects viral replication. In the course of the investigation of the cellular responses in the early stage of Influenza A virus (IAV) infection, we found that two miRNAs, miR-221 and miR-17-3p, which target the mRNA of GalNAc transferase 3 (GALNT3), are rapidly down-regulated as early as 1.5 h post-infection. Overall design: To understand the early host cell responses to the IAV infection, we performed miRNA microarray analysis using a human alveolar adenocarcinoma cell line, A549 cells, infected with influenza A/Puerto Rico/8/34 H1N1 (PR8) virus. We isolated the cellular RNAs at 0.5, 1.5 and 4.5 h post-infection and detected significant changes in the global profile of miRNA expression after infection with IAV. mouse embryonic fibroblasts. Each sample was run in duplicate.