Epigenetically regulated co-expression network of genes significant for rheumatoid arthritis
Aim: To identify epigenetically regulated network of genes in peripheral blood mononuclear cells significant for rheumatoid arthritis (RA). Methods: Differentially expressed genes (DEGs) and their associated differentially expressed miRNAs and differentially methylated positions (DMPs) were identified. Causal inference test (CIT) identified the causal regulation chains. The analyses, for example, weighted gene co-expression network (WGCNA), protein–protein interaction and functional enrichment, evaluated interaction patterns among the DEGs and the associated epigenetic factors. Results: A total of 181 DEGs were identified. The DEGs were significantly regulated by DMPs and/or differentially expressed miRNAs. Causal inference test analyses identified 18 causal chains of DMP-DEG-RA and 16 intermediate DEGs enriched in ‘protein kinase inhibitor activity’. BTN2A1 was co-expressed with other 9 intermediate genes and 11 known RA-associated genes and played a pivotal role in the co-expression network. Conclusion: Epigenetically regulated network of genes in peripheral blood mononuclear cells (PBMC) contributed to RA. The causal DMPs and key intermediate genes may serve as potential biomarkers for RA.