Figure 5. Transcriptomic profiling reveals that PLK1 inhibition reduces myofibroblast differentiation in the late inflammatory phase via the MAPK pathway. (A) Principal component analysis of six samples in the dataset. Each color represents one sample group. The red dot represents the vehicle group, the green triangle the TGF-β1+ DMSO group, and the blue square the TGF-β1+ BI6727 group. (B) Volcano plot of strongly upregulated (red; fold change > 2 and adjusted P value < 0.01) and downregulated (blue) genes in NIH-3T3 cells stimulated by TGF-β1 (1 ng/ml) vs DMSO (0.1%) for 72 h. There was a total of 414 upregulated and 444 downregulated genes. (C) Heatmap of differentially-expressed genes with BI6727 intervention. Red indicates increased gene expression, whereas blue indicates decreased gene expression. (D) KEGG pathway analysis of DEGs in PLK1-inhibited cells. The shades of the yellow bar correspond to -log10(P) Fisher’s exact test, used to select the significant (P < 0.05) pathways. (E) GSEA plot showing that PLK1 inhibition reduces myofibroblast differentiation in the late inflammatory phase via the MAPK pathway.