ABSTRACT: Macrophages possess the hallmark feature of plasticity, allowing them to undergo a dynamic transition between M1 and M2 polarized phenotypes. The aim of the present study was to screen for differentially expressed genes (DEGs) that were associated with macrophage polarization. The transcription profiles of three M1 and three M2 samples were obtained using microarray analysis. Based on the threshold of fold-change >2.0 and a p-value < 0.05, we screened a total of 1,253 DEGs, of which 696 were upregulated and 557 downregulated in M1 macrophages compared to that in M2 macrophages. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were also performed. A gene-gene interaction network of the DEGs was constructed using the STRING database. GO annotation identified three categories, which included cellular component (CC), molecular function (MF), and biological process (BP), with 34 and 40 enrichment terms consisting of upregulated and downregulated DEGs, respectively. GO enrichment analysis of DEGs was mainly associated with protein binding, response to stimulus, cell differentiation, and regulation of biological process. KEGG enrichment identified 15 and four pathways involving upregulated and downregulated DEGs, respectively. Signaling pathway analysis showed that these DEGs were mainly involved in apoptosis, HIF-1 signaling pathway, innate immune system, TNF signaling pathway, cytokine-cytokine receptor interaction, and other signal transduction pathways. Interaction network analysis indicated that Tnf, Il6, Il1b, Socs3, Nos2, Hif1a, and other genes may play key roles in macrophage polarization. This study provides new insights into the role of genes in macrophage differentiation and polarization.
