Transcriptome analysis reveals that defects in cell cycle regulation contribute to preimplantation embryo arrest.

Patients with preimplantation embryo arrest (PREMBA) often experience assisted reproductive failure primarily due to the lack of transferable embryos, and the molecular mechanisms underlying PREMBA remain unclear. In our study, the embryos from five women with recurrent preimplantation embryo arrest and three women with tubal factor infertility were used for single-embryo transcriptome sequencing. Meanwhile, the transcriptomes of normal human preimplantation embryos obtained from GSE36552 were utilized to perform a comparative analysis with the transcriptomes of PREMBA embryos. Our results showed dysregulation of the cell cycle phase transition might be a potential pathogenic factor contributing to PREMBA. Through integrated analysis of the differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA), we identified a number of hub genes using the protein-protein interaction network. The top 5 hub genes were as follows: CCNB2, BUB1B, CDC25A, CCNB3, and PLK3. The expression of hub genes was validated in PREMBA embryos and donated embryos using RT-qPCR. The knockdown of Ccnb2 in mouse zygotes led to an increase in embryo fragmentation, a rise in apoptosis, and a reduction in blastocyst formation. Furthermore, silencing the expression of CDC25A in HEK293T cells resulted in a decrease in cell proliferation and an increase in apoptosis, providing further support for our findings. Our findings could predict the development outcomes of preimplantation embryos and be used as potential therapeutic targets to prevent recurrent failures of IVF/ICSI attempts.