RNA sequencing analysis of embryos exposed to nanoplastics: effects on developmental and transcriptomic alteration

<title>Abstract</title> The increasing prevalence of nanoplastics (NPs) in the environment has raised concerns regarding their potential risks to ecosystems and human health. NP exposure has been shown to interfere with cellular processes; however, their effects on preimplantation embryonic development remain unclear. Given the critical role of zygotic genome activation and early cell cycle progression, disruption during this period can significantly affect embryonic viability. To investigate the molecular effects of polymethylmethacrylate (PMMA)-NPs on early embryonic development, mouse zygotes were exposed to 0.1 or 1 mg/mL PMMA-NPs, and RNA sequencing was performed on four-cell stage embryos. Differential gene expression analysis revealed that 0.1 mg/mL NP exposure affected genes related to DNA damage repair, transcriptional regulation, and cellular homeostasis while 1 mg/mL NP exposure altered the expression of genes associated with apoptotic signaling, cell cycle arrest, and failure of blastocyst formation, suggesting a concentration-dependent effect on developmental progression. Thus, PMMA-NP exposure disrupts early embryonic development by inducing specific transcriptomic changes that potentially affect genome integrity and developmental competency. This study provides new insights into the molecular mechanisms underlying NP-induced embryo toxicity and elucidate the effect of NPs on preimplantation embryo development.