Maternal nutrient restriction in guinea pigs leads to fetal growth restriction with increased brain apoptosis

Abstract

Background: We determined whether maternal nutrient restriction (MNR) in guinea pigs leading to fetal growth restriction (FGR) impacts cell death in the brain with implications for neurodevelopmental adversity. Methods: Guinea pigs were fed ad libitum (Control) or 70% of the control diet before pregnancy, switching to 90% at mid-pregnancy (MNR). Fetuses were necropsied near term and brain tissues processed for necrosis (H&E), apoptosis (TUNEL), and pro- (Bax) and anti- (Bcl-2 and Grp78) apoptotic protein immunoreactivity. Results: FGR-MNR fetal and brain weights were decreased 38% and 12%, respectively, indicating brain sparing but with brains still smaller. While necrosis remained unchanged, apoptosis was increased in the white matter and hippocampus in the FGR brains, and control and FGR-related apoptosis were increased in males for most brain areas. Bax was increased in the CA4 and Bcl-2 was decreased in the dentate gyrus in the FGR brains supporting a role in the increased apoptosis, while Grp78 was increased in the FGR females, possibly contributing to the sex-related differences. Conclusions: MNR-induced FGR results in increased brain apoptosis with regional and sex-related differences that may contribute to the reduction in brain area size reported clinically and increased risk in FGR males for later neurodevelopmental adversity.