Analysis of differential gene expression of heart failure based on Gene Expression Omnibus database

Background To screen and identify key genes involved in heart failure and explore underlying molecular mechanisms. Methods The expression profile of GSE26887 was downloaded from Gene Expression Omnibus (GEO), which contained 24 samples, including 19 left ventricle cardiac tissue of heart failure and 5 controls. The differentially expressed genes (DEGs) were obtained and got further analysis by bioinformatics methods. The DEGs and volcano plot were acquired with the use of ‘lima’ package in ‘R’ software and heat map was drawn through the ‘heatmap’ package. Gene ontology (GO) and pathway analysis of DEGs were performed by means of Database for Annotation, Visualization and Integrated Discovery (DAVID) and Kyoto Encyclopedia of Genes and Genomes (KEGG) online analyses, respectively. The DEGs interaction and network map were constructed through Search Tool for the Retrieval of Interacting Genes (STRING ) database and Cystoscope(v3.6.0)software. Results The transcriptome analysis of left ventricle cardiac tissue showed that 236 genes were differentially expressed between heart failure and control, of which 124 were significantly upregulated (P < 0.01) and 101 genes downregulated (P < 0.01). GO analysis uncovered that DEGs were enriched in extracellular space, extracellular matrix, extracellular matrix organization, cell adhesion, proteinaceous extracellular matrix and heparin binding. Thus, the function of extracellular matrix is mainly affected. The KEGG pathway enrichment indicated that the DEGs were involved in eight pathways, of these pathways, ECM-receptor interaction, Drug metabolism-cytochrome P450 and Pathogenic Escherichia coli infection are dominant. Protein-protein interaction (PPI) revealed the interactions of 30 protein products encoded of DEGs. Of the 30 protein products, the critical gene, called Interleukin-6 (IL6), was identified with the use of Cystoscope software. Conclusion Extracellular matrix and IL6 play an important role in the development of heart failure. Functional annotation and pathway analysis of these main genes were identified, which provide the basis for insight into the underlying pathogenetic mechanisms and predicting therapeutic targets of heart failure.