Figure 3.

Heatmap analysis of plasma lipidome data. Male C57BL/6 mice were intranasally inoculated with PBS control or PBS comprising PR8 virus (50 or 500 PFU), and lipidome analyses determined the concentrations of 297 molecules in the plasma samples collected at 1, 3, and 6 dpi (n = 5 mice). After data filtering on the basis of relative standard deviation, the remaining 222 values were then log-transformed and normalized by the autoscaling function. Within them, 169 significant features were found; false discovery rate (FDR) < 0.01, one-way analysis of variance (ANOVA). (a) Utilizing the top 100 lipids with the lowest FDR values, heatmap analysis with data clustering was performed using Euclidean distance measuring and a Ward clustering algorithm. The colored boxes indicate the relative values of the features in each group. The three major clusters are shown in gray, red, and blue. (b) Concentrations of PEs containing monounsaturated fatty acid (MUFA; PE-MUFA) and polyunsaturated fatty acid (PUFA; PE-PUFA) and (c) the ratios of PE-PUFA to PE-MUFA are shown separately. (b,c) In each panel, dots represent individual values, the box shows the interquartile range, the horizontal line within the box shows the median value, and the whiskers/vertical lines show maximum (top) and minimum (bottom) values. White, light gray, and dark gray boxes indicate data from PBS control, and 50 or 500 PFU of PR8 virus-infected mice, respectively. Two-way ANOVA using a multiple comparison correction. (a–c) PR8 influenza virus A/Puerto Rico/8/34, PFU plaque-forming unit, dpi day-post-infection.