Time resolved study of cell death mechanisms induced by amine-modified polystyrene nanoparticles

Abstract

Positively charged polymers and nanoparticles (NPs) can be toxic to cells in various systems. Using human astrocytoma cells, we have previously shown that 50 nm amine-modified polystyrene NPs damage mitochondria and induce cell death by apoptosis. Here we provide comprehensive details of the cellular events occurring after exposure to the NPs in a time-resolved manner. We demonstrate that the accumulation of NPs in lysosomes plays a central role in the observed cell death, leading to swelling of the lysosomes and release of cathepsins into the cytosol, which ultimately propagates the damage to the mitochondria with subsequent activation of apoptosis. This is accompanied and sustained by other events, such as increasing ROS levels and autophagy. Using various inhibitors, we also show the interplay between apoptosis and autophagy as a response to NP accumulation in lysosomes.

Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae

“…Common functionalized PS NPs include anionic carboxylated (-COOH) and cationic unsaturated amino (-NH 2 ) (Casado et al, 2013;Loos et al, 2014). Several studies revealed their cellular uptake using in vitro models with human cell lines (Bramini et al, 2014;Lesniak et al, 2010;Liu et al, 2011;Lunov et al, 2011;Rossi et al, 2014), but also cytotoxicity and apoptosis in particular for PS-NH 2 (Bexiga et al, 2011;Wang et al, 2013a). Based on the current data, PS NPs uptake and toxicity depend on their intrinsic properties such as size and surface charges which affect their interaction with exposure media (Della Torre et al, 2014a).…”

Coating of Quantum Dots strongly defines their effect on lysosomal health and autophagy

“…This type of enlargement is a commonly reported phenomenon and has been described for various NMs including ZnO NPs, fullerenol NPs, polystyrene NPs and QDs. [27,[60][61][62] Interestingly, the increase in In combination with the reduced oxidative stress, this could explain the lack of toxicity we observed upon exposure of HeLa cells to these QDs. Our findings thus confirm that MPA-coated QDs are quite biocompatible.…”

Hemocyte responses of the thick shell mussel Mytilus coruscus exposed to nano-TiO 2 and seawater acidification

“…Wang et al (2013) suggested that lysosomal damage caused by NP exposure can increase the amount of apoptotic cell death. Caza et al (2015) observed the induction of cell death in mussel hemocytes from both M. edulis and Aulacomya ater exposed to cadmium.…”