Methylmercury Promotes Oxidative Stress and Activation of Matrix Metalloproteinases: Cardiovascular Implications

Preclinical and clinical studies worldwide have shown an association between methylmercury (MeHg) poisoning and the risk of developing cardiovascular diseases such as arrhythmias, arterial hypertension, atherosclerosis and myocardial infarction. One of the hypotheses raised for MeHg-induced toxicity is associated with redox imbalance, which promotes oxidative stress by increasing reactive oxygen species (ROS) and reducing the activity of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). In addition, oxidative stress and organomercurial compounds are capable of activating MMPs. MMP-2 and MMP-9 participate in pathophysiological processes associated with cardiovascular remodeling. A positive correlation between mercury exposure and increased plasma activity of MMP-2 and circulating MMP-9 has been demonstrated, suggesting a possible mechanism that could increase susceptibility to cardiovascular diseases.