Screening and experimental validation of key genes in non-alcoholic fatty liver disease based on bioinformatics

Objective: To explore potential key genes and microRNAs (miRNAs) in non-alcoholic fatty liver disease (NAFLD).Methods: Two gene expression profile chips (GSE96936 and GSE62267) were downloaded from the Gene Expression Omnibus (GEO) database of the National Center for Biotechnology Information (NCBI) in the United States.The differentially expressed genes (DEGs) in the NAFLD group and the control group were screened using GEO2R online tool, the GO and KEGG signaling pathway enrichment analysis was carried out on DEGs, and the protein-protein interaction (PPI) network was further constructed using STRING database.Key genes were screened out using Cytoscape to construct the NAFLD mouse model, the selected key genes were verified by realtime fluorescence quantitative polymerase chain reaction (RT-qPCR) and NetworkAnalyst was used to construct targeted miRNAs of key genes.Results: A total of 192 DEGs were identified.GO analysis showed that the biological functions of DEGs were mainly involved in five KEGG pathways, including signaling pathways related to steroid hormone biosynthesis, complement and coagulation cascade, biliary secretion, chemical carcinogenesis, and retinol metabolism.Combined with the results of PPI and CytoHubba, ten key genes, Tyrobp, Hck, Ctss, Aif1, Fcgr1, Cd68, Cd53, Ly86, Fyb and Alox5ap, were screened out RT-qPCR showed that compared with the normal liver tissues, the mRNA expression of Ly86 in the NAFLD liver tissues was down-regulated (P< 0.05), while the mRNA expressions of Hck, Ctss, Aif1, Fcgr1, Cd68, Cd53, Alox5ap and Fyb in the NAFLD liver tissues were upregulated (P< 0.05).According to the visualization of DEGs-miRNAs, four miRNAs (mmu-miR-155-5p, mmumiR-122-5p, mmu-miR-124-3p and mmu-miR-1a-3p) were closely linked to key genes, and were predicted to be the key miRNAs of NAFLD.Conclusion: The research findings will contribute to identifying potential biomarkers and new strategies for the treatment of NAFLD.