ROS and NF-kappaB are involved in upregulation of IL-8 in A549 cells exposed to multi-walled carbon nanotubes.

Carbon nanotubes (CNTs) have potential applications in biosensors, tissue engineering, and biomedical devices because of their unique physico-chemical, electronic and mechanical properties. However, there is limited literature data available concerning the biological properties and toxicity of CNTs. This study aimed to assess the toxicity exhibited by multi-walled CNTs (MWCNTs) and to elucidate possible molecular mechanisms underlying the biological effects of MWCNTs in A549 cells. Exposing A549 cells to MWCNTs led to cell death, changes in cell size and complexity, reactive oxygen species (ROS) production, interleukin-8 (IL-8) gene expression and nuclear factor (NF)-kappaB activation. Treatment of A549 cells with antioxidants prior to adding MWCNTs decreased ROS production and abrogated expression of IL-8 mRNA. Pretreatment of A549 cells with NF-kappaB inhibitors suppressed MWCNTs-induced IL-8 mRNA expression. These results indicate that MWCNTs are able to induce expression of IL-8 in A549 cells, at least in part, mediated by oxidative stress and NF-kappaB activation.