Responses of A549 human lung epithelial cells to cristobalite and α-quartz exposures assessed by toxicoproteomics and gene expression analysis

Ngoc Q Vuong; Patrick Goegan; Francesco De Rose; Dalibor Breznan; Errol M Thomson; Julie S O'Brien; Subramanian Karthikeyan; Andrew Williams; Renaud Vincent; Premkumari Kumarathasan

doi:10.1002/jat.3420

Responses of A549 human lung epithelial cells to cristobalite and α-quartz exposures assessed by toxicoproteomics and gene expression analysis

J Appl Toxicol. 2017 Jun;37(6):721-731. doi: 10.1002/jat.3420. Epub 2016 Dec 5.

Authors

Affiliations

¹ Inhalation Toxicology Laboratory, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada.
² Department of Biochemistry, Faculty of Science, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.
³ Biostatistics Section, Population Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada.
⁴ Analytical Biochemistry and Proteomics Laboratory, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada.

Abstract

In this study, we used cytotoxicity assays, proteomic and gene expression analyses to examine the difference in response of A549 cells to two silica particles that differ in physical properties, namely cristobalite (CR) and α-quartz (Min-U-Sil 5, MI). Cytotoxicity assays such as lactate dehydrogenase release, 5-bromo-2'-deoxyuridine incorporation and cellular ATP showed that both silica particles could cause cell death, decreased cell proliferation and metabolism in the A549 human lung epithelial cells. While cytotoxicity assays revealed little difference between CR and MI exposures, proteomic and gene expression analyses unveiled both similar and unique molecular changes in A549 cells. For instance, two-dimensional gel electrophoresis data indicated that the expression of proteins in the cell death (e.g., ALDH1A1, HTRA2 and PRDX6) and cell proliferation (e.g., FSCN1, HNRNPAB and PGK1) pathways were significantly different between the two silica particles. Reverse transcription-polymerase chain reaction data provided additional evidence supporting the proteomic findings. Preliminary assessment of the physical differences between CR and MI suggested that the extent of surface interaction between particles and cells could explain some of the observed biological effects. However, the differential dose-response curves for some other genes and proteins suggest that other physical attributes of particulate matter can also contribute to particulate matter-related cellular toxicity. Our results demonstrated that toxicoproteomic and gene expression analyses are sensitive in distinguishing subtle toxicity differences associated with silica particles of varying physical properties compared to traditional cytotoxicity endpoints. Copyright © 2016 Her Majesty the Queen in Right of Canada. Journal of Applied Toxicology published by John Wiley & Sons, Ltd.

Keywords: 2D-GE: two-dimensional gel electrophoresis; A549 cells; RT-PCR; cristobalite; cytotoxicity; genomics; proteomics; silica; α-quartz.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

A549 Cells
Cell Culture Techniques
Cell Survival / drug effects
Electrophoresis, Gel, Two-Dimensional
Epithelial Cells / drug effects*
Epithelial Cells / metabolism
Gene Expression Profiling / methods
Humans
Particulate Matter / chemistry
Particulate Matter / toxicity*
Proteome / drug effects*
Proteomics / methods
Quartz / chemistry
Quartz / toxicity
Sensitivity and Specificity
Silicon Dioxide / chemistry
Silicon Dioxide / toxicity*
Surface Properties
Transcriptome / drug effects*

Substances

Particulate Matter
Proteome
Quartz
Silicon Dioxide