A large scale mass spectrometry-based histone screening for assessing epigenetic developmental toxicity

Area of Science:

• Epigenetics and Toxicology
• Biochemical analysis of histone modifications

Background:

• Toxicoepigenetics investigates chemical effects on gene expression via heritable, non-genetic mechanisms like histone post-translational modifications (hPTMs).
• Advancements in studying hPTMs offer new toxicological insights, meeting demand for human-based in vitro toxicity assays, particularly for developmental toxicity.

Purpose of the Study:

• To develop and validate a mass spectrometry-based assay for screening multiple hPTM changes simultaneously in human embryonic stem cells.
• To assess the assay's capability in mapping hPTM dynamics and its scalability for toxicity testing.

Main Methods:

• Development of a mass spectrometry-based, untargeted workflow for histone code screening.
• Validation using valproic acid (VPA), a known histone deacetylase inhibitor.
• Dose-response study on ten compounds with known hPTM effects, developmental toxicity classifications, or presumed effects.

Main Results:

• The assay successfully mapped hPTM dynamics, showing increased acetylations with VPA treatment.
• Demonstrated the assay's capability to detect multiple hPTM changes.
• Showcased scalability through dose-response analysis of diverse chemical compounds.

Conclusions:

• The developed histone code screening assay is a promising tool for toxicoepigenetics research.
• This assay can simultaneously detect multiple hPTM changes in human embryonic stem cells.
• It supports the development of high-throughput, human-based in vitro assays for toxicity testing, especially developmental toxicity.