Prenatal exposure to polystyrene nanoplastics caused testicular development toxicities and relative mechanisms in male offspring mice from embryo to adulthood.

Polystyrene nanoplastics (PS-NPs) are extensively present in the environment. Population studies have confirmed the presence of micro- and nanoplastics in human blood and placental tissues, and animal experiments found PS-NPs had potential developmental and reproductive toxicity. However, the continuous effects of prenatal PS-NPs exposure on testicular differentiation and development in offspring from embryo to adult are not clear. Therefore, this study aimed to investigate potential toxicity of prenatal exposure to PS-NPs on testicular development in offspring mice from embryonic day 11.5 (E11.5) to postnatal day 90 (PND90). Results showed that PS-NPs led to limited growth during embryonic period. After birth, PS-NPs caused catch-up growth, early onset of puberty, and reduced male reproductive capacity in adult mice. Moreover, we conducted further research on the possible mechanisms and found that PS-NPs might cause male reproductive developmental toxicity by inhibiting mRNA levels of genes related to testicular differentiation and development (Sry/Sox9/Fgf9, AMH, Dmrt1) from embryo to adulthood, which might have relationships with reduced number of Sertoli cells in the seminiferous tubules. Also, PS-NPs interfered with testosterone synthesis and disturbed lipid metabolism according to our proteomic analysis. This research may provide more evidence to the possible male developmental and reproductive toxicity induced by PS-NPs.