GR/HDAC3 Regulates Npas4 Signaling Pathway and Mediates Cognitive Impairment in Prenatal Hypoxia Male Offspring

Area of Science:

• Neuroscience
• Developmental Biology
• Reproductive Medicine

Background:

• Prenatal hypoxia (PH) is a significant complication of pregnancy.
• PH is linked to cognitive deficits in offspring, but mechanisms are poorly understood.
• Glucocorticoids (GC) and the hypothalamic-pituitary-adrenal (HPA) axis are implicated in stress responses.

Purpose of the Study:

• To investigate the mechanisms underlying cognitive impairment in male offspring exposed to prenatal hypoxia.
• To explore the role of the glucocorticoid receptor (GR)/histone deacetylase 3 (HDAC3)-Npas4 pathway in PH-induced neurodevelopmental changes.
• To evaluate the therapeutic potential of Mifepristone (MIF) in mitigating PH-related cognitive deficits.

Main Methods:

• Established a mouse model of PH by exposing pregnant C57 mice to hypoxia (10.5% O2) from gestational day 12.5 to 17.5.
• Assessed cognitive function and hippocampal neurogenesis in male offspring.
• Investigated the expression and localization of GR, HDAC3, and Npas4 in the hippocampus.
• Administered Mifepristone (MIF) to PH-exposed offspring to assess its effects.

Main Results:

• PH offspring exhibited cognitive impairment and reduced hippocampal neurogenesis.
• PH increased maternal GC transfer, leading to fetal HPA axis hyperactivity and GR downregulation.
• PH promoted GR/HDAC3 nuclear translocation, repressing Npas4 expression.
• MIF treatment ameliorated neurogenesis and cognitive deficits in PH offspring.

Conclusions:

• The GR/HDAC3-Npas4 signaling pathway is crucial in mediating hippocampal dysfunction and cognitive impairment following prenatal hypoxia.
• Targeting this pathway with GR antagonists like MIF offers a potential therapeutic strategy for fetal cognitive impairment.
• This study elucidates key molecular mechanisms linking prenatal stress to offspring neurodevelopmental outcomes.