An OGG1 polymorphism is associated with mitochondrial DNA content in pesticide-exposed fruit growers

Abstract

Exposure to pesticides has the capacity to cause mitochondrial dysfunction. An increase mitochondrial DNA (mtDNA) content has also been suggested to relate with DNA damaging agent. In mitochondria, the manganese superoxide dismutase (MnSOD) is a scavenger of reactive oxygen species, and the 8-oxoguanine DNA glycosylase (OGG1) is the major DNA glycosylase for the repair of 8-oxoG lesions. However, the alteration of mtDNA content elicited by pesticide exposure in people with genetic variations in MnSOD or OGG1 has not been investigated. In this study, the mitochondrial to nuclear DNA ratio was quantified in the peripheral blood of 120 fruit growers who experienced pesticide exposure and 106 unexposed controls by real-time quantitative polymerase chain reaction (real-time qPCR). Questionnaires were administered to obtain demographic data and occupational history. The MnSOD and OGG1 genotypes were identified by the PCR based restriction fragment length polymorphism analysis. After adjusting for confounding effects, multiple regression model revealed that subjects experiencing high or low pesticide exposure had a greater mtDNA content than that of controls. The OGG1 Ser-Ser genotype was also associated with an increased mtDNA content. No association between MnSOD genotype and mtDNA content was revealed. Thus, subjects experiencing pesticide exposure had greater mtDNA content and the OGG1 genotype may modulate mtDNA content in pesticide-exposed fruit growers.