Liver-specific decrease in Tff3 gene expression in infant mice perinatally exposed to 2,3,7,8-tetrabromodibenzofuran...

Area of Science:

• Environmental Toxicology
• Developmental Toxicology
• Molecular Toxicology

Background:

• Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs) are toxic byproducts of brominated flame retardants.
• Limited data exists on the health effects of PBDD/DFs, unlike their chlorinated counterparts.

Purpose of the Study:

• To investigate the toxicological effects of perinatal exposure to a specific brominated congener, 2,3,7,8-tetrabromodibenzofuran (TBDF), on infant mice.
• To compare the effects of TBDF with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

Main Methods:

• Mice dams were administered TBDF or TCDD on gestational day 12.5.
• Gene expression analysis (microarray and qPCR) was performed on liver and brain tissues of offspring.
• Ultrasonic vocalizations were recorded and analyzed in infant mice.

Main Results:

• Perinatal TBDF or TCDD exposure led to increased liver size in infant mice.
• Significant alterations in liver gene expression, including upregulation of Cyp1a1 and downregulation of Tff3, were observed in TBDF-exposed offspring.
• Impaired ultrasonic calling was noted in TBDF- and TCDD-exposed offspring.

Conclusions:

• Perinatal exposure to polyhalogenated dioxin/furan congeners disrupts hepatic gene expression and ultrasonic communication in infancy.
• Liver injury may be a contributing factor to the observed neurobehavioral deficits.