Mitochondrial dysfunction, disruption of F-actin polymerization, and transcriptomic alterations in zebrafish larvae exposed to trichloroethylene

Trichloroethylene (TCE) is primarily used as an industrial degreasing agent and has been in use since the 1940s. TCE is released into the soil, surface, and groundwater. From an environmental and regulatory standpoint more than half of Superfund hazardous waste sites on the National Priority List are contaminated with TCE. Occupational exposure to TCE occurs primarily via inhalation, while environmental TCE exposure also occurs through ingestion of contaminated drinking water. Current literature links TCE exposure to various adverse health effects including cardiovascular toxicity. Current studies aiming to address developmental cardiovascular toxicity utilized rodent and avian models with the majority of studies using relatively higher parts per million (ppm; mg/L) doses. In this study to further investigate developmental cardiotoxicity of TCE, zebrafish embryos were treated with 0, 10, 100, or 500 parts per billion (ppb; μg/L) TCE during embryogenesis and/or through early larval stages. After the appropriate exposure period, angiogenesis, F-actin polymerization, and mitochondrial function were assessed. A significant dose response decrease in angiogenesis, F-actin polymerization, and mitochondrial function was observed. To further complement this data, a transcriptomic profile of zebrafish larvae was completed to identify gene alterations associated with the 10 ppb TCE exposure. Results from the transcriptomic data revealed that an embryonic TCE exposure caused significant changes in genes associated with cardiovascular disease, cancer, and organismal injury and abnormalities with a number of targets in the FAK signaling pathway. Overall, results from our study further support TCE as a developmental cardiovascular toxicant and continued priority for environmental regulation. To identify whether an embryonic TCE exposure alters heart development, zebrafish embryos were exposed to 0, 10, 100, or 500 ppb TCE during embryogenesis and/or through early larval stages. Following the exposure periods, angiogenesis, F-actin polymerization, and mitochondrial potential were analyzed. In addition, a transcriptomic profile of zebrafish larvae was completed to identify gene alterations associated with the lowest exposure concentration of 10 ppb of TCE.