[Bioinformatics analysis of differentially expressed microRNAs in children with bronchial asthma]

Objective To study important micro-RNAs (miRNAs) and its target genes in children with asthma. Methods Microarray data of pediatric asthma (GSE120172) were downloaded from the GEO database and the differentially expressed miRNAs (DEMs) were analyzed with the R programming language. The potential target genes of DEMs were predicted by miRDB, miRTarBase and Targetscan tools, and annotated by the R software package clusterProfiler. Then the protein-protein interaction (PPI) and miRNA-hub gene network were constructed by the STRING database and Cytoscape software. Finally, the association between the hub gene and asthma was further verified by the CTD database. Results A total of 24 miRNAs were significantly differentially expressed, including 18 up-regulated and 6 down-regulated, and 297 target genes were predicted. The GO analysis showed that the target genes were mainly involved in epithelial cell proliferation and intercellular junction in the biological process, that the cellular components were mainly related to the plasma membrane and membrane components, and that the molecular functions included GTPase activity and receptor binding. KEGG pathway showed that target genes were mainly involved in the PI3K-AKT signal pathway and FoxO signal pathway. According to network analysis, miR-22-3p and miR-625-5p were important down-regulated molecules, while miR-206, miR-200b-3p, miR-548at-5p, miR-193a-3p and miR-935 were significantly up-regulated miRNAs associated with childhood asthma, and 15 potential target genes such as CCND1, SIRT1 and HDAC4 were the key genes selected. Conclusion The study has identified seven DEMs and their target genes that have potential roles in the occurrence and development of childhood asthma.