Transcriptomic fingerprints of C. elegans exposed to citrate coated superparamagnetic iron oxide nanoparticles (C-SPIONs)

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. We have investigated the molecular mechanisms responsive to in-house fabricated citrate coated SPIONs (C-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. C-SPIONs (500 µg/ml) affected the transcriptional response of signal transduction cascades (i.e. TFG-beta), protein processing in the endoplasmic reticulum, and RNA transport, among other biological processes. They also triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Interestingly, other pathways frequently linked to nanotoxicity like oxidative stress or apoptosis were not identified as significantly affected in this genome-wide in vivo study despite the high dose of exposure. The global transcriptome was compared in wild type N2 raised in the presence or absence of citrate-coated superparamagnetic iron oxide nanoparticles (C-SPIONs) at the concentration of 500 µg/mL for 24 hours at the L4 stage in 50% M9 buffer.