Valproic Acid Induces Post-Translational Redox Modifications in Mouse Embryos That Are Prevented via Prior Nrf2...

Area of Science:

• Developmental toxicology
• Oxidative stress biology
• Proteomics

Background:

• Valproic acid (VPA) is a known human developmental toxicant.
• VPA induces neural tube defects and neurobehavioral deficits, linked to oxidative stress.
• Cell models show VPA alters protein post-translational modifications (PTMs) differently in undifferentiated vs. differentiated cells.

Purpose of the Study:

• To investigate the response of early-stage mouse embryos (gestational day 8.5) to VPA exposure.
• To characterize VPA-induced changes in redox potentials and protein PTMs in vivo.
• To assess the protective role of Nrf2 activation against VPA's developmental toxicity.

Main Methods:

• Whole mouse embryo culture (gestational day 8.5) with VPA treatment.
• Time-course assessment of glutathione/glutathione disulfide redox potentials via HPLC.
• Analysis of protein redox states and PTMs (Pr-SOH, Pr-SSG) using blotting techniques and whole mount staining.

Main Results:

• VPA caused significant oxidation of redox potentials, peaking between 2-6 hours.
• VPA treatment increased protein sulfenylation (Pr-SOH) but not S-glutathionylation (Pr-SSG).
• Preemptive Nrf2 activation prevented VPA-induced redox potential oxidation and increased Pr-SOH.

Conclusions:

• Early-stage mouse embryos are highly sensitive to VPA, exhibiting an oxidative response similar to undifferentiated cells.
• VPA exposure promotes Pr-SOH formation, indicating susceptibility during specific developmental windows.
• Understanding redox regulation in embryos may inform strategies to prevent VPA-induced developmental defects.