Environ Health Toxicol.  2011 ;26(1):e2011013.

SiO2 Nanoparticles Induced Cytotoxicity by Oxidative Stress in Human Bronchial Epithelial Cell, Beas-2B

• Eom HJ
• Choi J

Abstract

OBJECTIVES
In this study, we investigated the potential harmful effect of the exposure to silicon dioxide (SiO2) nanoparticles through in vitro toxicity assay using human bronchial epithelial cell, Beas-2B with a focus on the involvement of oxidative stress as the toxic mechanism.
METHODS
SiO2-induced oxidative stress was assessed by examining formation of reactive oxygen species (ROS), the induction of superoxide dismutase (SOD) and heme oxygenase-1 (HO-1), as well as cytotoxicity effect was evaluation by cell viability. Subsequently, to understand the molecular mechanism of nanoparticle-induced oxidative stress, the involvement of oxidative stress-responding transcription factors, such as, nuclear factor-kappaB (NF-kappaB) and nuclear factor-E2-related factor-2 (Nrf-2), and mitogen-activated protein (MAP) kinase signal transduction pathway was also investigated.
RESULTS
5-d i phenyltera zolium bromide (MTT) assay results show that decrease 20% in cell viability and the number of cells in the subG1 phase increased. The increase in ROS formation was observed in SiO2 nanoparticle treated cells. The expression of SOD protein was not changed, whereas that of HO-1 was increased by SiO2 nanoparticle exposure. transcription factors Nrf-2 and the expression of phosphorylated form of extracellular signal-regulating kinase (ERK) was strongly induced by SiO2 nanoparticle exposure.
CONCLUSIONS
SiO2 nanoparticles exert their toxicity through oxidative stress as they cause the significant increase ROS level. SiO2 nanoparticles induce induction of HO-1 via Nrf-2-ERK MAP kinase pathway. Our tested oxidative stress parameters are rather limited in terms of allowing the full understanding of oxidative stress and cellular response by SiO2 nanoparticle exposure.

Keyword

Extracellular signal-regulating kinase; Heme oxygenase-1; Nuclear factor-E2-related factor-2; Oxidative stress; Silicon dioxide nanoparticles

MeSH Terms

Cell Survival
Epithelial Cells
Heme Oxygenase-1
Humans
Nanoparticles
Oxidative Stress
Phosphotransferases
Reactive Oxygen Species
Signal Transduction
Silicon Dioxide
Superoxide Dismutase
Transcription Factors
Heme Oxygenase-1
Phosphotransferases
Reactive Oxygen Species
Silicon Dioxide
Superoxide Dismutase
Transcription Factors