Nr2e1 Downregulation Is Involved in Excess Retinoic Acid-induced Developmental Abnormality in the Mouse Brain

Area of Science:

• Developmental Neuroscience
• Molecular Biology
• Toxicology

Background:

• Retinoic acid (RA) is crucial for embryonic development but can cause brain abnormalities at high doses.
• Nuclear receptor subfamily 2 group E member 1 (Nr2e1) is a transcription factor implicated in neural development.
• The precise role of Nr2e1 in RA-induced teratogenesis remains unclear.

Purpose of the Study:

• To investigate the expression pattern of Nr2e1 during retinoic acid (RA)-induced brain abnormality.
• To elucidate the functional role of Nr2e1 in neural stem cells (NSCs) under RA exposure.
• To understand the regulatory relationship between RA and Nr2e1.

Main Methods:

• Established a mouse model of brain abnormality using RA administration.
• Isolated and cultured mouse embryonic neural stem cells (NSCs) in vitro.
• Quantified Nr2e1 expression using in situ hybridization, RT-PCR, and Western blotting.
• Assessed Nr2e1 function via shRNA knockdown and its effect on the sonic hedgehog (Shh) pathway.
• Determined RA's regulation of Nr2e1 expression in vitro.

Main Results:

• Nr2e1 expression was significantly downregulated in the brains and NSCs of RA-treated mouse embryos.
• Knockdown of Nr2e1 impaired NSC proliferation in vitro.
• Similar expression patterns of Nr2e1 and retinoic acid receptor (RAR) α were observed upon RA treatment.
• RA treatment influenced Nr2e1 expression in cultured NSCs.

Conclusions:

• Nr2e1 expression is regulated by RA during neural development.
• RA-induced downregulation of Nr2e1 may contribute to observed brain abnormalities.
• This study provides insights into the molecular mechanisms of RA teratogenicity.