Nuclear Translocation of Nrf2 and Expression of Antioxidant Defence Genes in THP-1 Cells Exposed to Carbon Nanotubes

David M. Brown, Kenneth Donaldson, Vicki Stone

    Research output: Contribution to journalArticle

    34 Citations (Scopus)

    Abstract

    Carbon nanotubes have a wide range of applications in various industries and their use is likely to rise in the future. Currently, a major concern is that with the increasing use and production of these materials, there may be increased health risks to exposed workers. Long (>15 mu m) straight nanotubes may undergo frustrated phagocytosis which is likely to result in reduced clearance. We examine here the effects of multiwalled carbon nanotubes of different sizes on monocytic THP-1 cells, with regard to their ability to stimulate increased expression of the HO-1 and GST genes and their ability to produce nuclear translocation of the transcription factor, Nrf2, as well as the release of several pro-inflammatory cytokines and mediators of inflammation. Our results suggest that long (50 mu m) carbon nanotubes (62.5 mu g/ml for 4 hours) produce increased nuclear translocation of Nrf2 and increased HO-1 gene expression compared with shorter entangled nanotubes. There was no increased gene expression for GST. The long nanotubes (NT1) caused increased release of the pro-inflammatory cytokine IL-1 beta, an effect which was diminished by the antioxidant trolox, suggesting a role of oxidative stress in the upregulation of this cytokine. Tentatively, our study suggests that long carbon nanotubes may exert their effect in THP-1 cells in part via an oxidative stress mechanism.

    Original languageEnglish
    Pages (from-to)224-233
    Number of pages10
    JournalJournal of Biomedical Nanotechnology
    Volume6
    Issue number3
    DOIs
    Publication statusPublished - Jun 2010

    Keywords

    • CARBON NANOTUBES
    • THP-1 CELLS
    • TRANSCRIPTION FACTOR
    • ANTIOXIDANT
    • CYTOKINE

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