Comparative study on transcriptional responses of human neuronal cells to silica nanoparticles with different stabilizers

Abstract

There is growing concern about the safety of engineered nanoparticles, which are produced for various industrial applications. The potential applications of the nanoparticles are critically compromised due to the well documented toxicity and lack of understanding about the mechanisms involved in the intracellular responses. In this study, we investigated about the comprehensive set of biological responses by LUDOX® silica nanoparticles (commercial colloidal silica nanoparticles in aqueous phase) with two different types (similar size and charge but different stabilizers) in human neuronal cell line. The gene expression profiles were examined in SH-SY5Y cells exposed to LUDOX® silica AM and TM nanoparticles by using human whole genome oligonucleotide chip. Although the difference of cytotoxicity by silica AM and TM nanoparticles was not observed, transcriptional changes by these silica nanoparticles represented that silica TM affected to more many genes than silica AM. Several gene ontology (GO) categories of commonly changed genes by silica AM and TM nanoparticles include sterol metabolic process, lipid transport, ribosomal subunit, negative regulation of cellular component (including cytoskeleton) organization, and thyroglobulin type-1. In the case of silica TM nanoparticle data set, the changes of more various functions than it of silica AM were observed. Especially, functions related to cytoskeleton were annotated in both silica AM and TM nanoparticles. Therefore, it suggests that endocytosis of silica nanoparticles occurs by the reorganization of cell cytoskeleton through transcriptional changes of related genes. Thus, this study suggests that silica AM and TM nanoparticles affect on neuronal cell systems through a variety of interruption to biological processes. In the present study, we identified several silica AM and TM nanoparticles-responsive common genes. Further research is required to study the biological consequences of these differentially expressed genes (DEGs) and to verify usefulness of the potential biomarkers for risk assessment of silica nanoparticles.