title: Altered protein expression profile associated with phenotypic changes in lung fibroblasts co-cultured with gold nanoparticle-treated small airway epithelial cells.
abstract: Despite the availability of toxicity studies on cellular exposure to gold nanoparticles (AuNPs), there is scarcity of information with regard to the bystander effects induced by AuNPs on neighboring cells not exposed to the NPs. In this study, we showed that exposure of small airway epithelial cells (SAECs) to AuNPs induced changes in protein expression associated with functional effects in neighboring MRC5 lung fibroblasts in a co-culture system. Uptake of 20 nm size AuNPs by SAECs was first verified by focused ion beam scanning electron microscopy. Subsequently, pretreated SAECs were co-cultured with unexposed MRC5 lung fibroblasts, which then underwent proteome profiling using a quantitative proteomic approach. Stable-isotope labeling by amino acids in cell culture (SILAC)-based mass spectrometry identified 109 proteins (which included 47 up-regulated and 62 down-regulated proteins) that were differentially expressed in the lung fibroblasts co-cultured with AuNP pretreated SAECs. There was altered expression of proteins such as Paxillin, breast cancer anti-estrogen resistance 1 and Caveolin-1, which are known to be involved in the cell adhesion process. Morphological studies revealed that there was a concomitant increase in cell adhesion and altered F-actin stress fiber arrangement involving vinculin in the lung fibroblasts. It is likely that phenotypic changes observed in the underlying lung fibroblasts were mediated by AuNP-induced downstream signals in the pretreated SAECs and cell-cell cross talk.
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, Block MD10, S117594, Singapore.
authors.forename: Cheng-Teng
authors.initials: CT
authors.lastname: Ng
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, S117576, Singapore.
authors.forename: Lin-Yue Lanry
authors.initials: LY
authors.lastname: Yung
authors.affiliation: Quantitative Proteomics Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, 61 Biopolis Drive, S138673, Singapore.
authors.forename: Hannah Lee-Foon
authors.initials: HL
authors.lastname: Swa
authors.affiliation: Carl Zeiss Pte Ltd, Microscopy Business Group, Electron Microscopy, 50 Kaki Bukit Place, #05-01, S415926, Singapore.
authors.forename: Rebecca Wan-Yan
authors.initials: RW
authors.lastname: Poh
authors.affiliation: Quantitative Proteomics Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, 61 Biopolis Drive, S138673, Singapore. Electronic address: jayanthag@imcb.a-star.edu.sg.
authors.forename: Jayantha
authors.initials: J
authors.lastname: Gunaratne
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, Block MD10, S117594, Singapore. Electronic address: boon_huat_bay@nuhs.edu.sg.
authors.forename: Boon-Huat
authors.initials: BH
authors.lastname: Bay
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D006046:Gold / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D008168:Lung / Q000166:cytology*; D053768:Metal Nanoparticles / Q000737:chemistry*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning
chemical_list: D006046:Gold
keywords: AuNPs; Co-culture; Nanotoxicology; Proteome profiling; SILAC-based mass spectrometry