Host: The Japanese Society of Toxicology
Name : The 49th Annual Meeting of the Japanese Society of Toxicology
Date : June 30, 2022 - July 02, 2022
Microplastics are a growing problem in the environment and are materials that may be ingested orally. Recently, it was reported that polystyrene particles (PS-NPs) of about 0.1 ㎛ in diameter were taken up by Caco-2 cells, a model cell of the intestinal tract, and that some of these particles accumulated in lysosomes. This result indicates that microplastics may affect the regulatory mechanisms of cell survival. Azithromycin (AZM), a macrolide antibiotic, has been reported to adversely affect cells by excessive accumulation in lysosomes at high doses. When AZM is treated, the presence of PS-NPs may enhance the adversely effects of AZM. Therefore, in this study, we evaluated how PS-NPs modulate the effects of AZM by simultaneously treating Caco-2 cells with PS-NPs and AZM. Treatment of AZM alone inhibited cell proliferation and decreased viability at high concentrations. In addition, AZM treatment increased in LC3-II protein and the number and size of lysosomes. Treatment of AZM with PS-NPs increased LC3-II protein and the number and size of lysosomes. Combination of AZM and PS-NPs suppressed the proliferation of Caco-2 cells compared to AZM alone. These results indicated that the presence of PS-NPs enhanced the proliferation inhibition and the accumulation of autolysosomes by AZM, and it was considered that the adverse effects of AZM were enhanced by PS-NPs. The action of drugs that affect lysosomes may be enhanced by the presence of PS-NPs in the cells.
