Maternal Immune Stimulation With Interferon-Gamma Limits Embryonic Valproic Acid Induced Apoptotic Gene Expression

Area of Science:

• Developmental Biology
• Immunology
• Toxicology

Background:

• Neural tube defects (NTDs) affect approximately 1300 US newborns annually.
• Valproic acid (VA), an anticonvulsant and mood stabilizer, is a known teratogen causing NTDs.
• Increased apoptosis in embryonic neural tubes is a potential mechanism for VA-induced NTDs.

Purpose of the Study:

• To investigate the role of maternal immune stimulation (MIS) in preventing VA-induced NTDs.
• To examine the effects of MIS on maternal cytokine production.
• To analyze embryonic apoptotic gene expression following VA exposure and MIS.

Main Methods:

• Mice were treated with VA alone or with interferon-gamma (IFN-γ) plus VA.
• Maternal serum cytokine levels (GM-CSF, IFN-γ, IL-6, IL-10, TNFα) were measured.
• Apoptotic and anti-apoptotic gene expression was assessed in exposed embryonic neural tissues.

Main Results:

• MIS significantly decreased the incidence of NTDs (from 45.3% to 21.2%).
• MIS modulated maternal cytokine profiles, including GM-CSF, IFN-γ, IL-6, and IL-10.
• VA exposure upregulated pro-apoptotic genes and downregulated anti-apoptotic genes; this was normalized by VA + IFN-γ in embryos with closed neural tubes.

Conclusions:

• GM-CSF and IFN-γ are identified as potential mediators of MIS's protective effects against NTDs.
• MIS, via modulation of cytokines like GM-CSF, IL-6, and IL-10, normalizes apoptotic gene expression, offering a molecular basis for preventing VA-induced NTDs.