Protein expression profiles of intestinal epithelial co-cultures: effect of functionalised carbon nanotube exposure

Abstract

To assess the biological effects of low level, water dispersible, functionalised carbon nanotube (f-CNT) exposure in an in vitro model simulating the digestive tract, cellular protein expression was quantified and compared using label-free quantitative mass spectrometry (LFQMS). Co-cultured cells were exposed to well-characterised SWCNT-COOH, MWCNT-COOH, and MWCNT-PVP. The relative expression of 2,282 unique proteins was compared across the dose groups. 428 proteins were found to be differentially expressed. At the high dose, the extent of differential protein expression was CNT-specific and directly related to CNT colloidal stability. Cells responded to low level MWCNT-PVP exposure with three-fold greater differential expression. Bioinformatic analysis indicated significant and f-CNT-specific effects on relevant molecular and cellular functions and canonical pathways, with little overlap across f-CNT type and in the absence of overt toxicity.

Nanoparticle toxicity by the gastrointestinal route: evidence and knowledge gaps

“…In an important in vitro study, citrate-capped Au NP-protein complexes formed in Roswell Park Memorial Institute (RPMI) media were internalised in HeLa and U937 cells to a greater extent than those from Dulbecco’s Modified Eagle’s (DMEM) media, resulting in higher cytotoxic effects (Maiorano et al, 2010). Thus, variable coronal protein composition may lead to some of the different biological effects of NPs that are otherwise identical (Lai et al, 2012). The above studies emphasise the need for adequate characterisation of NPs, both before and after exposure to culture media or biological fluids.…”

“…Furthermore, proteomic platforms using stable isotope label-free quantitative mass spectrometry (LFQMS) (Neilson et al, 2011) have turned out to be proficient and reliable. LFQMS has recently been applied to the assessment of NP effects (Blazer-Yost et al, 2011; Teeguarden et al, 2011; Lai et al, 2012). Using an LFQMS approach,Lai et al (2012) reported the first extensive proteomic description of biological responses to functionalised carbon nanotubes (f-CNT) in intestinal cells, where 2,282 unique proteins were identified, quantified, and statistically compared.…”

“…LFQMS has recently been applied to the assessment of NP effects (Blazer-Yost et al, 2011; Teeguarden et al, 2011; Lai et al, 2012). Using an LFQMS approach,Lai et al (2012) reported the first extensive proteomic description of biological responses to functionalised carbon nanotubes (f-CNT) in intestinal cells, where 2,282 unique proteins were identified, quantified, and statistically compared. They found that exposure to even very low levels of f-CNT (500 pg/mL) resulted in significant concentration-dependent alterations in specific pathways and molecular/cellular functions.…”

“…A similar approach was taken in other studies using Caco-2 cells (Chiaretti et al, 2008; Kulamarva et al, 2008; Zhang et al, 2008; Ponti et al, 2010). Only two studies investigated fully differentiated and polarised, post confluent Caco-2 cells (Jos et al, 2009) and Caco-2/HT29-MTX co-cultures (Lai et al, 2012) where no toxic effects were observed below 100 µg/mL exposures. Studies of other NPs where fully differentiated cell monolayers were used have been indicated as such in Table 4.…”

Advantages and risks of nanotechnologies in cancer patients and occupationally exposed workers

“…It has been found in vitro that CNTs can induce proinflammatory responses in human keratinocyte cells in skin [91]. In particular, exposure of non-purified CNTs to mice skin seems to cause oxidative stress, glutathione depletion, increase of dermal cell number and skin thickening probably due to the presence of metals, particularly iron [92,93].…”