Epigenetic Analysis of Regulation of the Inflammasome-activating NLRP3 Gene in Monocytes From Atrial Fibrillation Patients and Controls

Overview

The study will analyze blood from volunteers to determine whether there is an underlying epigenetic cause of the inflammation of the heart associated with atrial fibrillation (AF) and its progression with age. Confirming the regions of epigenetic elements associated with upregulation of the inflammatory genes will help the investigators in identifying target sites for developing future therapeutic interventions. The investigators propose to confirm the monocyte-cell type specific DNA methylation profile of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and determine the age-related and AF-related changes in DNA methylation and expression of NLRP3 in monocytes. This study will provide insights into the epigenetic regulation of NLRP3 in young and elderly patients, as well as in AF patients vs. controls which will help in devising methods of modulating NLRP3 expression and decreasing cardiac fibrosis progression.

Blood samples will be collected from 30 female participants as follows: 10 women between the ages of 50 - 80 years diagnosed with AF as evidenced by rhythm strips or written documentation; 10 healthy women subjects between the ages of 50-80 years and 10 healthy women between the ages of 20-30 years. Participants will be recruited from the Tulane University Cardiology Clinics and also from volunteer research registries. These participants will be asked for consent to draw for another 8 ml (1.5 teaspoons) of blood during routine diagnostic blood draws. These blood samples will be de-identified by the PI upon receipt and no identifiable information will be maintained. Leukocyte subtypes including monocytes, neutrophils and B cells will be isolated from blood and DNA extraction will be carried out from the leukocyte subtypes. These leukocyte DNA samples will be sent to New England Biolabs, Ipswich, Massachusetts for DNA methylation analysis to identify target regions of epigenetic elements associated with upregulation of NLRP3 gene expression that might be related to disease progression with age. Real-Time Polymerase chain reaction (PCR) will be carried out at Tulane Research and Innovation for Arrhythmia Discoveries (TRIAD) Center, Tulane University School of Medicine from RNA extracted from leukocyte subtype to check the level of expression of NLRP3 highly associated with inflammation in AF.