Integrated bioinformatics analysis of aberrantly methylated-differentially expressed genes and pathways in age-related macular degeneration
Abstract Background: Age-related macular degeneration (AMD) represents the leading cause of visual impairment in the aging population. The goal of this study was to identify aberrantly methylated-differentially expressed genes (MDEGs) in AMD and explore the involved pathways by integrated bioinformatic analysis. Methods: Data of expression profiling GSE29801 and methylation profiling GSE102952 were obtained from the Gene Expression Omnibus database. We analyzed differentially methylated genes and differentially expressed genes in R software. Functional enrichment and protein–protein interaction (PPI) network analysis were performed using R package and Search Tool for the Retrieval of Interacting Genes online database. Hub genes were identified using Cytoscape. Results: 827 and 592 genes showed high and low expression, respectively, in GSE29801; 4117 hyper-methylated genes and 511 hypo-methylated genes were detected in GSE102952. After overlapping, we categorized 153 genes as hyper-methylated, low-expression genes (Hyper-LGs) and 24 genes as hypo-methylated, high-expression genes (Hypo-HGs). Four Hyper-LGs ( CKB , PPP3CA , TGFB2 , SOCS2 ) overlapped with AMD risk genes in Public Health Genomics and Precision Health Knowledge Base. KEGG pathway enrichment analysis indicated Hypo-HGs were enriched in the calcium signaling pathway, whereas Hyper-LGs were enriched in sphingolipid metabolism. In GO analysis, Hypo-HGs were enriched in fibroblast migration, membrane raft, coenzyme binding, etc. Hyper-LGs were enriched in mRNA transport, nuclear speck, DNA binding, etc. In PPI networks analysis, 23 nodes and 2 edges were established from Hypo-HGs, and 151 nodes and 73 edges were established from Hyper-LGs. Hub genes ( DHX9 , MAPT , PAX6 ) showed the greatest overlap. Conclusion: This study revealed potentially aberrantly MDEGs and pathways in AMD, which may improve the understanding of this disease.