Research

SiO₂ nanoparticles induce cytotoxicity and protein expression alteration in HaCaT cells

Xifei Yang^1* , Jianjun Liu^1* , Haowei He^1,2 , Li Zhou¹ , Chunmei Gong¹ , Xiaomei Wang² , Lingqing Yang^1,2 , Jianhui Yuan¹ , Haiyan Huang¹ , Lianhua He¹ , Bing Zhang^1,2 and Zhixiong Zhuang¹

¹  Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Centre for Disease Control and Prevention, No. 21, Road 1st Tianbei, Luohu District, Shenzhen, 518020, PR China

²  Department of Biochemistry and Molecular Biology, Life Science School, Shenzhen University, Nanhai Ave 3688, Shenzhen, 518060, PR China

author email corresponding author email* Contributed equally

Particle and Fibre Toxicology 2010, 7:1doi:10.1186/1743-8977-7-1

Published:	19 January 2010

Abstract

Background

Nanometer silicon dioxide (nano-SiO₂) has a wide variety of applications in material sciences, engineering and medicine; however, the potential cell biological and proteomic effects of nano-SiO₂ exposure and the toxic mechanisms remain far from clear.

Results

Here, we evaluated the effects of amorphous nano-SiO₂ (15-nm, 30-nm SiO₂). on cellular viability, cell cycle, apoptosis and protein expression in HaCaT cells by using biochemical and morphological analysis, two-dimensional differential gel electrophoresis (2D-DIGE) as well as mass spectrometry (MS). We found that the cellular viability of HaCaT cells was significantly decreased in a dose-dependent manner after the treatment of nano-SiO₂ and micro-sized SiO₂ particles. The IC₅₀ value (50% concentration of inhibition) was associated with the size of SiO₂ particles. Exposure to nano-SiO₂ and micro-sized SiO₂ particles also induced apoptosis in HaCaT cells in a dose-dependent manner. Furthermore, the smaller SiO₂ particle size was, the higher apoptotic rate the cells underwent. The proteomic analysis revealed that 16 differentially expressed proteins were induced by SiO₂ exposure, and that the expression levels of the differentially expressed proteins were associated with the particle size. The 16 proteins were identified by MALDI-TOF-TOF-MS analysis and could be classified into 5 categories according to their functions. They include oxidative stress-associated proteins; cytoskeleton-associated proteins; molecular chaperones; energy metabolism-associated proteins; apoptosis and tumor-associated proteins.

Conclusions

These results showed that nano-SiO₂ exposure exerted toxic effects and altered protein expression in HaCaT cells. The data indicated the alterations of the proteins, such as the proteins associated with oxidative stress and apoptosis, could be involved in the toxic mechanisms of nano-SiO₂ exposure.