Wang Rui, Dang Yan-Li, Zheng Ru, Li Yue, Li Weiwei, Lu Xiaoyin, Wang Li-Juan, Zhu Cheng, Lin Hai-Yan, Wang Hongmei
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China.
Department of Obstetrics and Gynecology, the 306th Hospital of PLA, Beijing, China.
Biol Reprod. 2014 Jun;90(6):117. doi: 10.1095/biolreprod.113.114892. Epub 2014 Apr 16.
Human trophoblast syncytialization, a process of cell-cell fusion, is one of the most important yet least understood events during placental development. Investigating the fusion process in a placenta in vivo is very challenging given the complexity of this process. Application of primary cultured cytotrophoblast cells isolated from term placentas and BeWo cells derived from human choriocarcinoma formulates a biphasic strategy to achieve the mechanism of trophoblast cell fusion, as the former can spontaneously fuse to form the multinucleated syncytium and the latter is capable of fusing under the treatment of forskolin (FSK). Live-cell imaging is a powerful tool that is widely used to investigate many physiological or pathological processes in various animal models or humans; however, to our knowledge, the mechanism of trophoblast cell fusion has not been reported using a live- cell imaging manner. In this study, a live-cell imaging system was used to delineate the fusion process of primary term cytotrophoblast cells and BeWo cells. By using live staining with Hoechst 33342 or cytoplasmic dyes or by stably transfecting enhanced green fluorescent protein (EGFP) and DsRed2-Nuc reporter plasmids, we observed finger-like protrusions on the cell membranes of fusion partners before fusion and the exchange of cytoplasmic contents during fusion. In summary, this study provides the first video recording of the process of trophoblast syncytialization. Furthermore, the various live-cell imaging systems used in this study will help to yield molecular insights into the syncytialization process during placental development.
人滋养层细胞融合是一种细胞间融合过程，是胎盘发育过程中最重要但也是最不为人所了解的事件之一。鉴于这一过程的复杂性，在体内胎盘研究融合过程极具挑战性。应用从足月胎盘中分离的原代培养细胞滋养层细胞以及源自人绒毛膜癌的BeWo细胞，形成了一种双相策略来实现滋养层细胞融合机制，因为前者可自发融合形成多核合体，而后者在福司可林（FSK）处理下能够融合。活细胞成像作为一种强大的工具，被广泛用于研究各种动物模型或人类中的许多生理或病理过程；然而，据我们所知，尚未有使用活细胞成像方式报道滋养层细胞融合机制的研究。在本研究中，使用活细胞成像系统来描绘原代足月细胞滋养层细胞和BeWo细胞的融合过程。通过用Hoechst 33342或细胞质染料进行活细胞染色，或通过稳定转染增强型绿色荧光蛋白（EGFP）和DsRed2-Nuc报告质粒，我们观察到融合前融合伙伴细胞膜上的指状突起以及融合过程中细胞质内容物的交换。总之，本研究提供了滋养层细胞融合过程的首个视频记录。此外，本研究中使用的各种活细胞成像系统将有助于深入了解胎盘发育过程中合体化过程的分子机制。
