Polystyrene microplastic particles induce autophagic cell death in BEAS‐2B human bronchial epithelial cells

Abstract

The detection of high levels of microplastics in indoor and outdoor air has increased concerns regarding its toxic effects on the respiratory system. They are not easily degradable and can be deposited deep in the lungs. Although several studies have reported inhalation toxicities of microplastics, they are still controversial due to a lack of evidence. Herein, we evaluated the inhalation toxicities of three differently charged polystyrene microplastics (PS-MPs), the most abundant microplastics in the air. Cytotoxicity and ROS generation were evaluated using WST-1 and DCF-DA assays, respectively. To evaluate the toxic effects on the lung, inflammatory responses were analyzed after repeated exposure to the PS-MPs through intratracheal instillation. To explore the mechanism of toxicity, autophagy and ER stress-associated proteins were analyzed. Only the positively charged PS-MPs (NH 2 -PS-MPs) showed cytotoxicity and increased ROS generation in BEAS-2B cells. Similarly, only NH 2 -PS-MPs significantly increased the expression and secretion of the pro-inflammatory cytokine IL-β in the animal experiments. The expression of ER stress proteins indicated that NH 2 -PS-MPs increased ER stress via PERK-EIF2α and ATF4-CHOP pathways. Moreover, accumulation of NH 2 -PS-MPs in lysosomes and deformity of the nucleus were observed in BEAS-2B cells with autophagy induction. Taken together, our results demonstrated that NH 2 -PS-MPs induced autophagic cell death in bronchial epithelial cells, leading to inflammatory responses in the lungs.These results suggest that repeated inhalation of microplastics can result in inflammatory responses in the lung through cellular damage of lung epithelial cells, and that inhalation microplastics should be monitored to reduce inhalation health risks.

Photodegradation of Microplastics by ZnO Nanoparticles with Resulting Cellular and Subcellular Responses

“…Provided that the increase of SSC intensity represented the uptake of particles in cells, the concentration-dependent increase of SSC by secondary MPs suggested that phototransformation enhanced the cellular uptake of MPs, in contrast to the nearly unchanged SSC intensity for original EMPs (Figure a). Due to the close contact of MPs on the cell membrane, the positively charged MPs showed higher cytotoxicity than the negatively charged MPs, which was opposite to the higher cytotoxicity caused by the carbonyl MPs in this study. However, fragmentation of MPs was induced by photocatalysis, possibly leading to different contacting behavior of MPs on cell surface.…”

The Effect of Plastic-Related Compounds on Transcriptome-Wide Gene Expression on CYP2C19-Overexpressing HepG2 Cells

“…However, plastic-related compounds may reduce this capacity by disrupting mitosis and DNA replication, blocking hepatocytes in G0/G1 phase. Moreover, the suppression of mitosis may cause cell death [ 82 , 83 ]. Regarding compounds 4 and 5 , the activation of pathways involved in autophagy was identified (such as ‘autophagy’ and ‘process utilizing autophagic mechanism’).…”

Important Factors Affecting Induction of Cell Death, Oxidative Stress and DNA Damage by Nano- and Microplastic Particles In Vitro

“…The results also depended on particle charge; only positively-charged particles (NH 2 -PS-MPs) triggered mechanisms that led to the initiation of different types of cell death. The results demonstrated that NH 2 -PS-MPs induced autophagic cell death in bronchial epithelial cells, leading to inflammatory responses in the lungs [58].…”