A new discovery of polystyrene microplastics toxicity: The injury difference on bladder epithelium of mice is correlated with the size of exposed particles

Microplastics (MPs), as widespread hazardous substances in the environment, can cause potential adverse effects on biological health. However, reports on the toxic effects of different diameters MPs on urinary system are limited. !ere, we investigated the types and mechanisms of damage to mice bladder epithelial cells treated with diameter (1-10 mu m and 50-100 mu m) polystyrene microplastics (PS-MPs). The results showed that exposure to PS-MPs of both diameters resulted in necroptosis and inflammation to bladder epithelium. However, 1-10 mu m PS-MPs posed more severe necroptosis and 50-100 mu m PS-MPs led to a higher degree of inflammatory injury at the same exposure concentration. Mechanistically, PS-MPs were found to induce necroptosis as well as p-NF kappa B-mediated inflammation by triggering oxidative stress and excessive release of reactive oxygen species (ROS). Furthermore, N-Acetyl-L-cysteine (NAC) attenuated the toxic effects of PS-MPs on bladder epithelial cells. In conclusion, our study demonstrated for the first time that PS-MPs caused necroptosis and inflammation in mice bladders tissues, and the difference of injury correlates with the size of PS-MPs particles.

Automated summary

This study investigated the types and mechanisms of damage caused by different diameters of polystyrene microplastics (PS-MPs) to mice bladder epithelial cells. The results showed that both diameters of PS-MPs led to necroptosis and inflammation in the bladder epithelium. 1-10 μm PS-MPs caused more severe necroptosis, while 50-100 μm PS-MPs led to a higher degree of inflammatory injury. Mechanistically, PS-MPs induced necroptosis and p-NF kappa B-mediated inflammation by triggering oxidative stress and excessive release of reactive oxygen species (ROS). Furthermore, N-Acetyl-L-cysteine (NAC) attenuated the toxic effects of PS-MPs on bladder epithelial cells.