The adverse effects of plastic on adult animal and human health have been receiving increasing attention. However, its potential toxicity to fetuses has not been fully elucidated. Herein, biodistribution of polystyrene (PS) particles was determined after the maternal mice were orally given PS micro- and/or nano-particles with and without surface modifications during gestational days 1 to 17. The results showed that PS microplastics (MPs) and nanoparticles (NPs) mainly emerged in the alimentary tract, brain, uterus, and placenta in maternal mice, and only the latter infiltrated into the fetal thalamus. PS NPs and carboxyl-modified NPs induced differentially expressed genes mainly enriched in oxidative phosphorylation and GABAergic synapse. Maternal administration of PS particles during gestation led to anxiety-like behavior of the progenies and their γ-aminobutyric acid (GABA) reduction in the prefrontal cortex and amygdala at Week 8. N-Acetylcysteine (NAC), an antioxidant, alleviated PS particles-induced oxidative injury in the fetal brain and rescued the anxiety-like behavior of the progenies. Additionally, PS nanoparticles caused excessive ROS and apoptosis in neuronal cell lines, which were prevented by glutathione supplementation. These results suggested that PS particles produced a negative effect on fetuses by inducing oxidative injury and suppressing GABA synthesis in their brain. The findings contribute to estimating the risk for PS particles to human and animal health.

Numerous post-translational modifications are involved in oocyte maturation and embryo development. Recently, lactylation has emerged as a novel epigenetic modification implicated in the regulation of diverse cellular processes. However, it remains unclear whether lactylation occurs during oocyte maturation and embryo development processes. Herein, the lysine lactylation (Kla) modifications were determined during mouse oocyte maturation and early embryo development by immunofluorescence staining. Exogenous lactate was supplemented to explore the consequences of modulating histone lactylation levels on oocyte maturation and embryo development processes by transcriptomics. Results demonstrated that lactylated proteins are widely present in mice with tissue- and cell-specific distribution. During mouse oocyte maturation, immunofluorescence for H3K9la, H3K14la, H4K8la, and H4K12la was most intense at the germinal vesicle (GV) stage and subsequently weakened or disappeared. Further, supplementing the culture medium with 10 mM sodium lactate elevated both the oocyte maturation rate and the histone Kla levels in GV oocytes, and there were substantial increases in Kla levels in metaphase II (MII) oocytes. It altered the transcription of molecules involved in oxidative phosphorylation. Moreover, histone lactylation levels changed dynamically during mouse early embryogenesis. Sodium lactate at 10 mM enhanced early embryo development and significantly increased lactylation, while impacting glycolytic gene transcription. This study reveals the roles of lactylation during oocyte maturation and embryo development, providing new insights to improving oocyte maturation and embryo quality.