GSE201753
Methylome and transcriptome profiling of giant cell arteritis monocytes reveals novel pathways involved in disease pathogenesis and molecular response to glucocorticoids [RNA-Seq]
Giant cell arteritis (GCA) is a complex systemic vasculitis mediated by the interplay between both genetic and epigenetic factors. Monocytes are crucial players of the inflammation occurring in GCA. Therefore, characterization of the monocyte methylome and transcriptome in GCA would be helpful to better understand disease pathogenesis. We performed an integrated epigenome- and transcriptome-wide association study in CD14+ monocytes from 82 patients with GCA, cross-sectionally classified into three different clinical status (active, in remission with or without glucocorticoid (GC)-treatment), and 31 healthy controls. We identified a global methylation and gene expression dysregulation in GCA monocytes. Specifically, monocytes from active patients showed a more pro-inflammatory phenotype compared with healthy controls and patients in remission. In addition to inflammatory pathways known to be involved in active GCA, such as response to interleukin (IL)-6 and IL-1, we identified a significant number of chemokines, such as CCRL2, and integrins. Furthermore, monocytes from patients in remission with treatment showed downregulation of genes involved in inflammatory processes as well as overexpression of GC receptor-target genes. Finally, we identified changes in DNA methylation correlating with alterations in expression levels of genes with a potential role in GCA pathogenesis, such as ITGA7 and CD63, as well as genes mediating the molecular response to GC, including FKBP5, ETS2, ZBTB16, and ADAMTS2. Our results revealed profound alterations in the methylation and transcriptomic profiles of monocytes from GCA patients, uncovering novel genes and pathways involved in GCA pathogenesis and in the molecular response to GC treatment. Overall design: DNA methylation and gene expression profiling analysis of Illumina Infinium EPIC array and RNA-seq data sets for CD14+ monocytes in healthy individuals and giant cell arteritis patients within three different clinical status (active (ACT), in remission with glucocorticoid (GC) treatment (RT), and in remission without treatment(RNT)).