Mapping differential cellular protein response of mouse alveolar epithelial cells to multi-walled carbon nanotubes as a function of atomic layer deposition coating

Abstract

Carbon nanotubes (CNTs), a prototypical engineered nanomaterial, have been increasingly manufactured for a variety of novel applications over the past two decades. However, since CNTs possess fiber-like shape and cause pulmonary fibrosis in rodents, there is concern that mass production of CNTs will lead to occupational exposure and associated pulmonary diseases. The aim of this study was to use contemporary proteomics to investigate the mechanisms of cellular response in E10 mouse alveolar epithelial cells in-vitro after exposure to multi-walled CNTs (MWCNTs) that were functionalized by atomic layer deposition (ALD). ALD is a method used to generate highly uniform and conformal nanoscale thin-film coatings of metals to enhance novel conductive properties of CNTs. We hypothesized that specific types of metal oxide coatings applied to the surface of MWCNTs by ALD would determine distinct proteomic profiles in mouse alveolar epithelial cells in-vitro that could be used to predict oxidative stress and pulmonary inflammation. Uncoated (U)-MWCNTs were functionalized by ALD with zinc oxide (ZnO) to yield Z-MWCNTs or aluminum oxide (Al2O3) to yield A-MWCNTs. Significant differential protein expression was found in the following critical pathways: mTOR/eIF4/p70S6K signaling and Nrf-2 mediated oxidative stress response increased following exposure to Z-MWCNTs, interleukin-1 signaling increased following U-MWCNT exposure, and inhibition of angiogenesis by thrombospondin-1, oxidative phosphorylation, and mitochondrial dysfunction increased following A-MWCNT exposure. This study demonstrates that specific types of metal oxide thin film coatings applied by ALD produce distinct cellular and biochemical responses related to lung inflammation and fibrosis compared to uncoated MWCNT exposure in-vitro.

Characterization of the proteome and lipidome profiles of human lung cells after low dose and chronic exposure to multiwalled carbon nanotubes

“…Finally, although not included in the IPA dataset due to lack of identification in one of the low dose samples, HIF1A-inhibitor HIF1AN was found to be nearly 4-fold down-regulated in the high dose concentration in agreement with the increased ROS and the up-regulated HIF1A expression observed in the apoptosis experiments. Hilton et al (2017) using mouse alveolar epithelial cells in vitro investigated the effects of pristine (uncoated) MWCNTs and surface coated (functionalized) CNTs with zinc oxide (ZnO) or aluminum oxide (Al 2 O 3 ) metal oxides. They found distinct proteomic profiles in mTOR/eIF4/p70S6K signaling and Nrf-2 mediated oxidative stress response pathways.…”

“…For instance, human epidermal keratinocytes displayed differential expression of more than 30 and 100 proteins after 24 and 48 h of MWCNT exposure, respectively (Witzmann and Monteiro-Riviere 2006). Similarly, other proteomic analyses have identified alterations in the expression of several proteins upon MWCNT exposure (Haniu et al 2010;Ju et al 2014;Hilton et al 2015Hilton et al , 2017. These findings indicate that toxicoproteomic analyses may provide valuable information on the mechanisms underlying toxicity of MWCNTs.…”

Effects on human bronchial epithelial cells following low-dose chronic exposure to nanomaterials: A 6-month transformation study

“…For instance, human epidermal keratinocytes displayed differential expression of more than 30 and 100 proteins after 24 and 48 h of MWCNT exposure, respectively (Witzmann and Monteiro-Riviere 2006). Similarly, other proteomic analyses have identified alterations in the expression of several proteins upon MWCNT exposure (Haniu et al 2010;Ju et al 2014;Hilton et al 2015Hilton et al , 2017. These findings indicate that toxicoproteomic analyses may provide valuable information on the mechanisms underlying toxicity of MWCNTs.…”