Toxicity induction of nanopolystyrene under microgravity stress condition in Caenorhabditis elegans.

Caenorhabditis elegans is a useful animal model for assessing adverse effects of environmental toxicants or stresses. C. elegans was used as an assay system to investigate the effects of exposure to nanopolystyrene (30 nm) on wild-type and sod-3 mutant animals under microgravity stress condition. Using brood size and locomotion behaviors as endpoints, we found that nanopolystyrene exposure enhanced the toxicity of microgravity stress on nematodes, and this toxicity enhancement could be further strengthened by mutation of sod-3 encoding a Mn-SOD protein. Induction of reactive oxygen species (ROS) production and activation of mitochondrial unfolded protein response (mt UPR) were associated with this toxicity enhancement. In sod-3 mutant nematodes, the enhancement in toxicity of microgravity stress by exposure to nanopolystyrene (10 μg/L) was detected. Our data will be helpful for understanding the potential effects of nanopolystyrene exposure on nematodes under the microgravity stress condition.