Effects of MeHg on ROS regulation in neutrophil cell culture

Abstract

"Methylmercury (MeHg) is an environmental toxin that targets the nervous system but can cause an array of effects on other systems as well. The main source of exposure is through fish consumption, because MeHg bioaccumulates in fresh water and marine food chains. MeHg has a high affinity for selenium and sulfur in the body, which assists in its solubility as well as its toxicity. MeHg has been shown to inhibited redox regulatory enzymes such as glutathione peroxidase (GPx). Inhibition of this enzyme leads to toxic levels of reactive oxygen species (ROS) which can damage DNA, proteins and lipids inside of the cell. Neutrophils, cells of the innate immune response, utilize these ROS to degrade pathogens. These cells utilize GPx to regulate ROS from causing cell damage. Protocols, assays and analytical methods were developed and modified to measure GPx activity and amount of lipid peroxidation within cell cultures. Embryonic chick brain cells were used to develop and modify methods. These cells showed decreases in GPx activity but not lipid oxidation. The neutrophil cell culture did not produce enough signals to measure, suggesting a possible interference within the neutrophil matrix. The data from this study suggests that cell culture can be used to analyze direct exposure of MeHg but the methods might need to be altered for every different cell that is being tested."