title: Live cell imaging of in vitro human trophoblast syncytialization.
abstract: 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.
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Obstetrics and Gynecology, the 306th Hospital of PLA, Beijing, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Dang
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China College of Life Science, Beijing Normal University, Beijing, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China linhy@ioz.ac.cn.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China wanghm@ioz.ac.cn.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Wang
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D001562:Benzimidazoles / Q000494:pharmacology; D002459:Cell Fusion / Q000379:methods; D045744:Cell Line, Tumor; D002822:Choriocarcinoma / Q000473:pathology; D005576:Colforsin / Q000494:pharmacology; D003593:Cytoplasm / Q000502:physiology; D005260:Female; D005456:Fluorescent Dyes / Q000494:pharmacology; D006801:Humans; D021962:Membrane Microdomains / Q000502:physiology*; D008856:Microscopy, Fluorescence / Q000379:methods*; D018715:Microscopy, Video / Q000379:methods*; D010929:Placentation / Q000502:physiology*; D011247:Pregnancy; D061251:Primary Cell Culture; D014327:Trophoblasts / Q000166:cytology* / Q000187:drug effects; D014594:Uterine Neoplasms / Q000473:pathology
chemical_list: D000276:Adjuvants, Immunologic; D001562:Benzimidazoles; D005456:Fluorescent Dyes; D005576:Colforsin; C017807:bisbenzimide ethoxide trihydrochloride
keywords: BeWo; developmental biology; live imaging; placental development; placentation; pregnancy; primary cultured cytotrophoblast cells; syncytialization; syncytiotrophoblast; trophoblast