Multi-omics analysis of dynamic dose-response in macrophages recapitulates multi-walled carbon nanotube -induced lung fibrosis [methylation]

Toxicogenomics approaches are increasingly applied to gain mechanistic insight into the toxicity of engineered nanomaterials (ENMs). These emerging technologies have been shown to aid the translation of in vitro experimentation into relevant information on real-life exposures. Furthermore, integrating multiple layers of molecular alteration can improve the systemic understanding of the toxicological insult. While evidence of the immunotoxic effects of several ENMs is arising, the mechanisms are less characterized, and the dynamics of the molecular adaptation of the immune cells are still largely unknown. Here, we carried out a multi-omics approach characterizing the dynamic dose-dependent (DDD) molecular alterations in a model of human macrophages. THP-1 macrophages were exposed to increasing concentrations of rigid multiwalled carbon nanotubes (rCNTs) and the genome-wide alterations in the transcriptome and gene promoter methylation were assessed at three consecutive time points. The results suggest dynamic patterns of molecular alterations with a rapid response in the gene expression and contribution of DNA methylation in the long-term adaptation. Moreover, our analytical approach is able to highlight patterns of molecular alteration in vitro that recapitulate several elements of pathogenesis of pulmonary fibrosis, a known long-term effect of rCNTs exposure in vivo. DNA methylation profiles of THP-1 macrophages exposed to three concentrations (5, 10 or 20 µg/mL) of rigid multi-walled carbon and untreated controls were profiled at 24, 48 and 72 hours. Exposures were performed as triplicates, untreated controls with four replictes.