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

The effects of long-term chronic exposure of human lung cells to multi-walled carbon nanotubes (MWCNT) and their impact upon cellular proteins and lipids were investigated. Since the lung is the major target organ, an in vitro normal bronchial epithelial cell line model was used. Additionally, to better mimic exposure to manufactured nanomaterials at occupational settings, cells were continuously exposed to two non-toxic and low doses of a MWCNT for 13-weeks. MWCNT-treatment increased ROS levels in cells without increasing oxidative DNA damage and resulted in differential expression of multiple anti- and pro-apoptotic proteins. The proteomic analysis of the MWCNT-exposed cells showed that among more than 5000 identified proteins; more than 200 were differentially expressed in the treated cells. Functional analyses revealed association of these differentially regulated proteins to cellular processes such as cell death and survival, cellular assembly, and organization. Similarly, shotgun lipidomic profiling revealed accumulation of multiple lipid classes. Our results indicate that long-term MWCNT-exposure of human normal lung cells at occupationally relevant low-doses may alter both the proteome and the lipidome profiles of the target epithelial cells in the lung.