Phenotypically Anchored mRNA and miRNA Expression Profiling in Zebrafish Reveals Flame Retardant Chemical Toxicity...

Area of Science:

• Environmental Toxicology
• Molecular Biology
• Genomics

Background:

• Flame retardant chemicals (FRCs) are widely used, leading to environmental contamination and human exposure.
• Assessing the toxicological impact of diverse FRCs is challenging due to their varied properties.
• Previous studies identified aryl phosphates as particularly active FRCs in zebrafish models.

Purpose of the Study:

• To investigate gene expression responses to 10 structurally diverse flame retardant chemicals (FRCs) in zebrafish.
• To identify common and unique mRNA and micro-RNA (miR) expression patterns across different FRCs.
• To establish a regulatory network involving mRNA, miR, and transcription factors (TFs) to understand FRC mechanisms.

Main Methods:

• Paired mRNA-micro-RNA (miR) sequencing was performed on zebrafish exposed to 10 selected FRCs.
• Differential gene expression analysis identified affected mRNAs and miRs.
• Bioinformatic tools predicted regulatory interactions between mRNAs, miRs, and transcription factors (TFs).

Main Results:

• Widespread disruption of mRNA and miR expression was observed across multiple FRCs, with neurodevelopment being a key affected process.
• Commonly differentially expressed molecules included specific mRNAs (e.g., osbpl2a) and miRs (e.g., mir-125b-5p).
• Predicted regulatory networks implicated TFs (e.g., retinoic acid receptor) and revealed potential roles in development and cancer signaling.

Conclusions:

• This study establishes the first comprehensive mRNA-miR-TF regulatory network for a diverse set of FRCs.
• The findings highlight neurodevelopmental disruption as a common toxicological outcome of FRC exposure.
• The developed approach provides a valuable tool for understanding the mechanisms of action of environmental contaminants.