Prenatal progesterone treatment modulates fetal brain transcriptome and impacts adult offspring behavior in mice

Maternal exposure to elevated levels of steroid hormones during pregnancy is associated with the development of chronic conditions in offspring that manifest in adulthood. However, the effects of progesterone (P4) administration during early pregnancy on fetal development and subsequent offspring behavior remain poorly understood. In this study, we aimed to investigate the effects of P4 treatment during early pregnancy on the transcript abundance in the fetal brain and assess the behavioral consequences in the offspring during adolescence and adulthood. Using RNA-seq analysis, we examined the impact of P4 treatment on the fetal brain transcriptome in a dosage-dependent manner. Our results revealed differential regulation of genes involved in neurotransmitter transport, synaptic transmission, and transcriptional regulation. Specifically, we observed bidirectional regulation of transcription factors (TFs) by P4 at different doses, highlighting the critical role of these TFs in neurodevelopment. To assess behavioral outcomes, we conducted open field and elevated plus maze tests. Offspring treated with low-dose P4 (LP4) displayed increased exploratory behavior during both adolescence and adulthood. In contrast, the high-dose P4 (HP4) group exhibited impaired exploration and heightened anxiety-like behaviors compared to the control mice. Moreover, in a novel object recognition test, HP4-treated offspring demonstrated impaired object recognition memory during both developmental stages. Additionally, both LP4 and HP4 groups showed reduced social interaction in the three-chamber test. These results suggest that prenatal exposure to P4 exerts a notable influence on the expression of genes associated with neurodevelopment and may induce alterations in behavioral characteristics in progeny, highlighting the need to monitor progesterone levels during pregnancy for long-term impacts on fetal brain development and behavior.