Effects of multiple stressors on DNA damage occurrence

This dissertation examines numerous environmental contaminants and their combined effects on DNA damage occurrence and repair. The environment is readily assaulted by complex mixtures of contaminants and stressors which likely affect the physiology of both humans and wildlife. Many of these ubiquitous contaminants interfere with cellular processes and pathways in the liver, including DNA repair pathways. These experiments examine different combinations of environmental stressors, and allow us to explore potential mechanistic effects in realistic exposure scenarios. Here we show that hepatic tissues (in vivo) and cells (in vitro) exposed to singular contaminants do not demonstrate significant changes in DNA damage occurrence and repair. However, in situations where multiple environmental stressors were introduced, significant changes occur in gene expression analyses and DNA damage formation. Additionally, DNA repair efficiency was adversely affected after exposure to a combination of stressors. Data presented here add to the growing body of knowledge on the varying effects of DNA damaging agents in both laboratory and field exposures. This research aims to give insight on potential hepatic impacts of these combination-exposure scenarios with respect do DNA damage and repair mechanisms.