Gene Expression Analysis Suggests Immunological Changes of Peripheral Blood Monocytes in the Progression of Patients With Coronary Artery Disease

FIGURE 1. Volcano plots of differentially expressed genes (DEGs). (A) ICL group vs. NCA group; (B) AMI group vs. NCA group. X-axis represents log2 the fold change of gene expression in the compared groups, and Y-axis represents-1 × log10 (FDR value) for each DEG. Red dots indicate up-regulated DEGs, blue dots indicate down-regulated DEGs, and gray dots indicate non-significant DEGs. DEGs, differentially expressed genes. NS, None Significant.

FIGURE 2. Venn map shows the intersection of up-regulated (A) and down-regulated (B) DEGs between ICL vs. NCA and AMI vs. NCA.

FIGURE 3. (A) The heat map of the 98 DEGs overlapping between ICL group vs. NCA group and AMI group vs. NCA group. The X-axis represents the samples, NCA1 – NCA8: NCA controls (n = 8); ICL1 – ICL8: ICL patients (n = 8); AMI1 – AMI8: AMI patients (n = 8). The Y-axis denotes the DEGs. The red and blue tones in the picture indicate the expression levels of DEGs (represents by log2FPKM) and the colors changing from blue to red indicate higher expression levels. (B) The scatter plot of the 98 DEGs. The X-axis represents the log2 FC of DEGs between ICL and NCA. The Y-axis denotes log2 FC of DEGs between AMI and NCA. DEGs, differentially expressed genes; FPKM, Fragments per Kilobase per Million Mapped Fragments; FC, Fold Change.

FIGURE 4. Bar plot of GO enrichment analysis of DEGs overlapping between ICL group vs. NCA group and AMI group vs. NCA group. X-axis represents –log10 P value. Y-axis represents different functional groups (also named as different GO terms). The green bars indicate cellular component terms, the blue bars indicate biological process terms, and the red bars indicate molecular function term.

FIGURE 5. Bubble Plot of KEGG enrichment analysis of DEGs overlapping between ICL group vs. NCA group and AMI group vs. NCA group. X-axis represents ratios of the number of differential genes to the total gene number in a specific pathway. The color and size of the dots represent significance and amount of genes enrichment, respectively. DEGs, differentially expressed genes, KEGG, Kyoto Encyclopedia of Genes and Genomes.

FIGURE 6. KEGG enrichment pathways of DEGs related to IL-17 signal pathway and cytokine–cytokine receptor interaction. Up-regulated genes are marked with red, down-regulated genes are marked with blue. DEGs, differentially expressed genes; KEGG, Kyoto Encyclopedia of Genes and Genomes.

FIGURE 7. Hub genes identified from the protein-protein interaction (PPI) network. (A) PPI network of 98 DEGs related to the progression of CAD, consisting of 54 nodes and 161 edges. The edge indicates the interaction between two genes. A degree is used to describe the importance of the protein nodes in the network. Color of the hubs is related to connectivity degree. Brighter red of node color is for more connectivity of the DEGs. (B) PPI network of 10 hub genes extracted from (A). Up-regulated genes are marked with red, down-regulated genes are marked with blue. CAD, coronary artery disease. DEGs, differentially expressed genes.

FIGURE 8. The expression levels of five hub genes (represents by FPKM) identified from the PPI analysis (A–E). *P < 0.05, **P < 0.01, ***P < 0.001.