Bdnf-Nrf-2 crosstalk and emotional behavior are disrupted in a sex-dependent fashion in adolescent mice exposed to maternal stress or maternal obesity

Abstract

Abstract Maternal obesity affects the developing fetal brain, leading to long-term negative outcomes comparable to those resulting from maternal psychological stress, although the mechanisms have not been completely elucidated. In this study we tested the hypothesis that prenatal adverse conditions as diverse as maternal stress and maternal obesity might affect emotional regulation and stress response in the offspring through common pathways, with a main focus on oxidative stress and neuroplasticity. We contrasted and compared adolescent male and female offspring in two mouse models of maternal psychophysical stress (restraint during pregnancy - PNS) and maternal obesity (high-fat diet before and during gestation - mHFD) by combining behavioral assays, evaluation of the hypothalamic-pituitary-adrenal (HPA) axis reactivity and gene expression analysis of selected neuroinflammatory and plasticity-related markers in the hippocampus as a key region involved in stress appraisal. Prenatal administration of the antioxidant N-acetyl-cysteine (NAC) was used as a strategy to protect fetal neurodevelopment from the negative effects of PNS and mHFD. Our findings show that these two stressors produce comparable effects, reducing brain anti-oxidant defenses (Nrf-2), leading to sex-dependent impairments of hippocampal Bdnf expression and alterations of the emotional behavior and HPA axis functionality. Prenatal NAC administration, by restoring the redox balance, was able to exert long-term protective effects on brain development, suggesting that the modulation of redox pathways might be an effective strategy to target common shared mechanisms between different adverse prenatal conditions.