Li Yanhe, Zheng Caihong, Liu Yingdong, He Jincan, Zhang Qiang, Zhang Yalin, Kou Xiaochen, Zhao Yanhong, Liu Kuisheng, Bai Dandan, Jia Yanping, Han Xiaoxiao, Sheng Yifan, Yin Jiqing, Wang Hong, Gao Shuai, Liu Wenqiang, Gao Shaorong
Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China.
Natl Sci Rev. 2023 Aug 16;10(9):nwad173. doi: 10.1093/nsr/nwad173. eCollection 2023 Sep.
Somatic cell nuclear transfer (SCNT) can reprogram differentiated somatic cells into totipotency. Although pre-implantation development of SCNT embryos has greatly improved, most SCNT blastocysts are still arrested at the peri-implantation stage, and the underlying mechanism remains elusive. Here, we develop a 3D culture system for SCNT peri-implantation embryos and discover that persistent Wnt signals block the naïve-to-primed pluripotency transition of epiblasts with aberrant H3K27me3 occupancy, which in turn leads to defects in epiblast transformation events and subsequent implantation failure. Strikingly, manipulating Wnt signals can attenuate the pluripotency transition and H3K27me3 deposition defects in epiblasts and achieve up to a 9-fold increase in cloning efficiency. Finally, single-cell RNA-seq analysis reveals that Wnt inhibition markedly enhances the lineage developmental trajectories of SCNT blastocysts during peri-implantation development. Overall, these findings reveal diminished potentials of SCNT blastocysts for lineage specification and validate a critical peri-implantation barrier for SCNT embryos.
体细胞核移植（SCNT）能够将分化的体细胞重编程为全能性细胞。尽管SCNT胚胎的植入前发育已得到显著改善，但大多数SCNT囊胚仍在植入周围阶段停滞，其潜在机制仍不清楚。在此，我们为SCNT植入周围胚胎开发了一种三维培养系统，并发现持续的Wnt信号通过异常的H3K27me3占据阻止上胚层从原始多能性向始发态多能性的转变，这反过来又导致上胚层转化事件缺陷和随后的植入失败。引人注目的是，操纵Wnt信号可以减弱上胚层多能性转变和H3K27me3沉积缺陷，并使克隆效率提高多达9倍。最后，单细胞RNA测序分析表明，Wnt抑制在植入周围发育过程中显著增强了SCNT囊胚的谱系发育轨迹。总体而言，这些发现揭示了SCNT囊胚在谱系特化方面的潜力降低，并验证了SCNT胚胎植入周围的关键障碍。
