Arsenic ions (As3+) have been recognized as a hazard that threatens the health of humans. Metallothionein (MT) rich in cysteine may provide favorable binding sites for chelation of As3+. However, the influence of MT on As3+-induced toxicity and the underlying mechanism are poorly understood, especially at the metabolic level. Herein, the effects of MT on As3+-induced toxicity were evaluated. Cell viability analysis suggested that MT alleviated As3+-induced cytotoxicity. The metabolic response of PC12 cells to As3+ investigated by lipidomics and metabolomics indicated that the presence of As3+ disrupted phospholipids metabolism and induced cell membrane damage. Moreover, energy and amino acid metabolism were perturbed by As3+. The perturbation of As3+ on metabolism was further illustrated by the decrease of the mitochondrial membrane potential and the rise of cellular reactive oxygen species (ROS). On the contrary, MT rescued As3+-induced metabolic disorder and suppressed ROS accumulation. In addition, the binding process between As3+ and MT was characterized. The results proved that the As3+-MT complex was formed and chelated As3+-scavenged ROS, thus alleviating the toxic effects of As3+. These results revealed that MT would be a potential agent to reduce As3+-induced cytotoxicity.
Keywords: arsenic ions; cell cycle; lipidomics; metabolism; metallothionein.