Influenza A alters host miRNA expression. (A) PCR analysis of individual miRNAs that showed differential expression in microarray analysis. miRNA isolated after 3 h of exposure to influenza A (A/WS/33 (H1N1), A/Aichi/2/68 (H3N2), A/Swine/1976/31 (H1N1), and A/Swine/Iowa/15/30 (H1N1)), (MOI of 3). The fold change represents the change in miRNA expression in infected cells relative to that obtained in uninfected cells. (B) A549 cells were infected with 3MOIs of influenza A (A/WS/33 (H1N1), A/Aichi/2/68 (H3N2), A/Swine/1976/31 (H1N1), and A/Swine/Iowa/15/30 (H1N1)), for 3 h and matrix copy numbers were determined by RT-PCR. (C) NS1ABP mRNA expression was normalized to expression of GAPDH mRNA in response to 3MOI of influenza. Data are expressed as ± standard error of the mean (SEM). n=4 (independent experiments) with triplicate replicates (*=p<0.05, **=p<0.01, ***=p<0.001). (D) PCR analysis of individual miRNAs in human bronchial epithelial cells (HBEpC) exposed to influenza A (A/WS/33 (H1N1), and A/Aichi/2/68 (H3N2)). miRNA isolated after 3 h of exposure to influenza A (MOI of 3). The fold change represents the change in miRNA expression in infected cells relative to that of uninfected cells. (E) HBEpC cells were infected with 3 MOIs of influenza A for 3 h and matrix copy numbers were determined by RT-PCR. (F) NS1ABP mRNA expression was normalized to expression of GAPDH mRNA in response to 3MOI of influenza A. p<0.05 was considered significant. The fold change represents the change in miRNA and mRNA expression in infected cells relative to that of uninfected cells. Data are expressed as ± standard error of the mean (SEM). n=4 (independent experiments) with triplicate replicates (*=p<0.05, **=p<0.01, ***=p<0.001).