Omics analyses of stromal cells from ACM patients reveal alterations in chromatin organization and mitochondrial homeostasis [Bisulfite-Seq]

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder, characterized by ventricular ar-rhythmias, contractile dysfunctions and fibro-adipose replacement of the myocardium. Cardiac mesenchymal stromal cells (CMSC) participate to disease pathogenesis by differentiating towards adipocytes and myofibroblasts. Some altered pathways in ACM are known, but many are yet to be discovered. In order to define changes in the gene expression profiles between ACM- and HC-CMSC, we performed a high throughput Bisulfite-seq on 6 ACM and 6 HC samples. Out of 12466 expressed peaks, 30 resulted differentially expressed. Through enrichment and gene network analyses, we identified differentially regulated pathways, some of which never associated with ACM, including mitochondrial functioning and chromatin organization. Functional validations confirmed that ACM-CMSC exhibited a higher amount of active mitochondria and ROS production, a lower proliferation rate and a more pronounced epicardial-to-mesenchymal transition, compared to controls. In conclusion, ACM-CMSC -omics revealed some additional altered molecular pathways, relevant in the disease pathogenesis, which may constitute novel targets for specific therapies. DNA was extracted 6 ACM and 6 control CMSC, and methylome analyses were performed by bisulfite conversion of DNA combined with next generation sequencing (NGS).