Comparative case study on NAMs: towards enhancing specific target organ toxicity analysis.

Area of Science:

• Toxicology and Ecotoxicology
• In Vitro Toxicology
• Omics Technologies

Background:

• Traditional toxicology relies on animal testing, facing ethical and reproducibility concerns.
• New Approach Methodologies (NAMs) offer mechanistic insights but struggle with whole-organism and toxicokinetic limitations.
• Bridging in vitro omics data to in vivo organ toxicity prediction is a significant challenge.

Purpose of the Study:

• To evaluate the transferability of NAM data by conducting comparative in vitro-in vivo studies.
• To assess the predictive power of transcriptomics and targeted proteomics from human cell lines for organ toxicity.
• To connect early cellular responses in vitro to established in vivo effects of pesticide active substances.

Main Methods:

• HepaRG and RPTEC/tERT1 human cell lines were exposed to hepatotoxic and nephrotoxic pesticide active substances at non-cytotoxic concentrations.
• Transcriptome-wide gene expression was analyzed using quantitative real-time PCR arrays.
• Proteome analysis was performed using multiplexed microsphere-based sandwich immunoassays.
• Bioinformatics tools were employed to analyze transcriptomics data and link in vitro endpoints to in vivo observations.

Main Results:

• Transcriptomics analysis revealed significant cellular responses, with Chlorotoluron showing the strongest impact in HepaRG cells (increased CYP1A1 and CYP1A2 expression).
• Targeted protein analysis identified affected pathways, with fewer effects observed in RPTEC/tERT1 cells compared to HepaRG cells.
• Transcriptomics data demonstrated a higher predictive capacity, correctly identifying up to 50% of observed in vivo effects, outperforming targeted protein analysis.

Conclusions:

• Comparative in vitro-in vivo studies are valuable for assessing NAM data transferability.
• Transcriptomics analysis of human cell lines shows significant potential for predicting in vivo organ toxicity.
• NAMs, particularly transcriptomics, offer a promising alternative to traditional animal testing in toxicology risk assessment.