A FACS-Based Reporter Assay Prototype Employing the Mouse AHR Protein Sensitively and Autonomously Detects Dioxins in...

Area of Science:

• Environmental Science
• Toxicology
• Cell Biology

Background:

• Amphibian cells are sensitive to freshwater and osmotic stress, making them ideal environmental sentinels.
• Low activity of the amphibian aryl hydrocarbon receptor (AHR) protein limits their use in dioxin detection.
• Existing methods like RT-PCR have limitations in sensitivity and application for dioxin detection in amphibians.

Purpose of the Study:

• To develop a novel dioxin detection assay using amphibian cells.
• To enhance the sensitivity of amphibian cells to dioxins by introducing a mouse AHR gene.
• To create a reliable and reproducible method for monitoring environmental contaminants.

Main Methods:

• Designed dual vectors with an inducer cassette (mouse AHR and mCherry) and a reporter cassette (xenobiotic response elements driving GFP).
• Utilized Fluorescence-Activated Cell Sorting (FACS) analysis for measurements.
• Normalized GFP/mCherry intensity ratio on a cell-by-cell basis for reproducible results.

Main Results:

• The novel assay successfully detected various persistent organic pollutants (POPs) in Xenopus tropicalis frog cells at picomolar to nanomolar concentrations.
• Achieved a 400-fold improvement in sensitivity compared to traditional RT-PCR assays.
• Demonstrated high reproducibility in detecting diverse POPs including TCDD, PeCDF, B[k]F, PeCDD, PCB126, and dBA.

Conclusions:

• Engineered amphibian cells provide a sensitive and robust platform for dioxin detection.
• This assay expands the toolkit for environmental dioxin monitoring using readily available amphibian cell lines.
• The developed method offers a significant advancement over existing techniques for detecting persistent organic pollutants in aquatic environments.