Identification of hub genes associated with oxidative stress in heart failure and their correlation with immune infiltration using bioinformatics analysis

Figures

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  Figure 1. Oxidative stress-related differentially expressed genes in heart failure. (A) Volcano plot of differentially expressed genes (DEGs). The horizontal axis represents the fold change of gene expression between the Sham and TAC groups, and the longitudinal coordinate represents the P-value of the expression difference. The black dots represent genes without significant differences, the red dots represent upregulated differential genes, and the blue dots represent differential downregulated genes. (B) Venn diagrams showing intersected genes overlapping between OSRGs and DEGs. (C) The Heatmap of clustering analysis based on OSRDEGs. OSRGs, oxidative stress-related genes; DEGs, differentially expressed genes; OSRDEGs, oxidative stress-related differentially expressed genes.

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  Figure 2. Functional enrichment analysis of oxidative stress-related differentially expressed genes (OSRDEGs). (A) GO enrichment of OSRDEGs. The number of enriched OSRDEGs in the path is represented by the circled area, and the color of the circle represents the range of the P value. (B) KEGG pathway analysis of OSRDEGs. the color of the circle represents the enriched items in KEGG pathway analysis. GO, Gene Ontology; BP, biological processes; CC, cellular component. MF, molecular function. KEGG, Kyoto Encyclopedia of Genes and Genomes.

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  Figure 3. Construction of PPI network and hub gene analysis. (A) Protein–protein interaction networks of OSRDEGs. The nodes represent proteins, and the edges represent the interaction of proteins. (B) The top five key OSRDEGs were identified based on the degree of nodes. PPI, protein–protein interaction.

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  Figure 4. Immune cell infiltration patterns in TAC samples and Sham samples. (A) Bar charts of the proportions of 25 immune cell in TAC and Sham sample. Different colors represent different types of immune cells. horizontal axis: GEO samples; longitudinal coordinate: percentage of each immune cell type. (B) Differentially infiltrated immune cells between TAC and Sham sample. Red represents the sham group; blue represents the TAC group. *p < 0.05.

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  Figure 5. Correlation analyzes between immune cell and hub genes. Association of MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 with 25 of types immune cells. Horizontal axis represents the immune cells; longitudinal coordinate represents the hub genes; The numbers in the red triangle represent correlation coefficient, the lager the number, the stronger the correlation. The numbers in the blue triangle represent p value.

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  Figure 6. Validation of key OSRDEGs expression at the mRNA levels. MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 mRNA level in the TAC and Sham groups in mice. Expression levels were standardized for GAPDH levels. A two-tailed unpaired Student’s t-test was used to compare two groups. Values are expressed as means ± SD (n = 4), *p < 0.05; **p < 0.01 and ***p < 0.001 vs Sham group.

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  Figure 7. Validation of key OSRDEGs expression at protein levels by immunohistochemistry. (A) IHC staining of MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 proteins in the TAC and Sham groups. (B) Quantitative analysis of MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 proteins in the TAC and sham groups. A two-tailed unpaired Student’s t-test was used to compare two groups. Values are expressed as means ± SD (n = 3). *p < 0.05 and **p < 0.01 vs Sham group; original magnification, ×200. Scale bar: 100 µm. IHC, Immunohistochemistry.

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  Figure 8. Validation of key OSRDEGs expression at protein levels by western blotting. (A) Representative western blotting of MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 proteins of heart tissues in the TAC and Sham groups. (B) Quantitative analysis of MAPK14, HIF1a, Myc, Hsp90ab1 and Hsp90aa1 proteins of heart tissues in the TAC and sham groups. A two-tailed unpaired Student’s t-test was used to compare two groups. Values are expressed as means ± SD (n = 3). *p < 0.05 vs Sham group.