Single-nucleus multi-omics implicates androgen receptor signaling in cardiomyocytes and NR4A1 regulation in fibroblasts during atrial fibrillation.

The dysregulation of gene expression programs in the human atria during persistent atrial fibrillation (AF) is not completely understood. Here, we reanalyze bulk RNA-sequencing datasets from two studies (N = 242) and identified 755 differentially expressed genes in left atrial appendages of individuals with persistent AF and non-AF controls. We combined the bulk RNA-sequencing differentially expressed genes with a left atrial appendage single-nucleus multi-omics dataset to assign genes to specific atrial cell types. We found noncoding genes at the IFNG locus (LINC01479, IFNG-AS1) strongly dysregulated in cardiomyocytes. We defined a gene expression signature potentially driven by androgen receptor signaling in cardiomyocytes from individuals with AF. Cell-type-specific gene expression modules suggested an increase in T cell and a decrease in adipocyte and neuronal cell gene expression in AF. Lastly, we showed that reducing NR4A1 expression, a marker of a poorly characterized human atrial fibroblast subtype, fibroblast activation markers, extracellular matrix remodeling and cell proliferation decreased.