DNA methylation changes associated with exposure to wildfire smoke in dogs enrolled in the Dog Aging Project

Abstract

This study investigates the association between wildfire smoke and DNA methylation changes and how those changes may cause disease. We utilize data from the Precision Cohort in the Dog Aging Project which includes methylome data from peripheral blood mononuclear cells for 527 dogs. Our analysis employs reduced-representation bisulfite sequencing to measure DNA methylation levels. Wildfire smoke exposure was defined using fire report data available from the National Interagency Fire Center. Our results indicate that exposure to wildfire smoke leads to a significant change in DNA methylation, with 667 sites hypermethylated and 198 sites hypomethylated. Functional gene annotation indicates that there are several associations between the upregulation (hyper-) and downregulation (hypo-) of the significant genes. These biological implications include factors contributing to cardiovascular disease, lung disease, and cancer which are diseases known to result from smoke exposure. While the evidence from this study does not prove the causal link between DNA methylation and disease, it does show that there are DNA methylation changes associated with exposure to wildfire smoke.