GSE157616
Epigenetic effects of silver nanoparticles and ionic silver in Tetrahymena thermophila
The widespread use of silver nanoparticles (Ag NPs) has raised substantial health risks to environmental and human beings. Although various negative effects had been reported, little is known about the epigenetic toxicity induced by Ag+ and Ag NPs. This study characterized physiological and lncRNA profiles to explore the toxic effects and epigenetic mechanisms in Tetrahymena thermophila on exposure to Ag+ and three types of Ag NPs. We found that both of Ag+ and Ag NPs exhibited strong growth-inhibiting effects on T. thermophila. The toxicity was mainly caused by high levels of reactive oxygen species (ROS), which subsequently led to lipid peroxidation and mitochondrial dysfunction. As a defense mechanism against oxidative stress, the protist elicited an antioxidant response. Importantly, 1250 lncRNAs were differentially expressed under Ag+ or Ag NPs exposure relative to the non-exposure control, which were clustered into 15 expression modules in weighted gene co-expression network analysis. These gene modules exhibited toxicant-specific expression patterns, indicating that they play various regulatory roles, including cell growth inhibition, cell membrane cation channel activation, and oxidoreductase activity promotion. Taken together, this research illuminates how post-transcriptional mechanisms of a ciliated protozoa regulate responses to Ag+ and Ag NPs toxicities. Overall design: We conducted lncRNA sequencing after the 24h-IC50 concentration of the Ag+ and three types of silver nanoparticles (Ag-Cit10, Ag-Cit80 and Ag-PVP80) were treatment on Tetrahymena thermophila for 24h, respectively. Each treatment conducted 3 replicates,and totally 15 samples were generated.