Department of Obstetrics and Gynecology, University of British Columbia, 4490 Oak Street, Vancouver, British Columbia, Canada V6H 3V5.
J Clin Endocrinol Metab. 2011 Dec;96(12):3881-90. doi: 10.1210/jc.2010-2714. Epub 2011 Oct 12.
The formation of the multinucleated syncytiotrophoblast of the human placenta by the terminal differentiation and fusion of mononucleate cytotrophoblasts is a critical step in pregnancy. Previous studies have demonstrated that this cellular event is dependent on a progressive decrease in the levels of the cell-adhesion molecule, E-cadherin.
The aim of the study was to examine the role of Twist, a transcription factor identified as a key repressor of E-cadherin expression, in the differentiation of human trophoblastic cells.
The expression of Twist or E-cadherin were first examined in first-trimester chorionic villi by immunohistochemistry. Gain- or loss-of-function studies on Twist were then performed in BeWo choriocarcinoma cells. The presence or absence of multinucleated syncytium was confirmed by indirect immunofluorescence using antibodies directed against Twist, E-cadherin, or desmoplakin, a cellular marker of mononucleate cytotrophoblasts.
The formation of multinucleated syncytium was associated with increased Twist and a decreased E-cadherin expression. Similarly, exogenous expression of Twist resulted in a continuous and progressive decrease in E-cadherin expression and the subsequent formation of syncytium in BeWo cells maintained under normal culture conditions. In contrast, small interfering RNA specific for Twist inhibited 8-Br-cAMP (8-bromoadenosine 3',5'-cyclic monophosphate)-mediated differentiation and fusion of over time in culture.
Twist is an upstream regulator of the E-cadherin-mediated terminal differentiation and fusion in a human trophoblastic cell line in vitro.
人类胎盘的多核合胞滋养层的形成是通过单核滋养细胞的终末分化和融合，这是妊娠的关键步骤。先前的研究表明，这种细胞事件依赖于细胞黏附分子 E-钙黏蛋白水平的逐渐降低。
本研究旨在探讨转录因子 Twist 在人滋养细胞分化中的作用，该转录因子被鉴定为 E-钙黏蛋白表达的关键抑制因子。
首先通过免疫组织化学法检测妊娠早期绒毛组织中 Twist 和 E-钙黏蛋白的表达。然后在 BeWo 绒毛膜癌细胞中进行 Twist 的功能获得或功能丧失研究。通过间接免疫荧光法用针对 Twist、E-钙黏蛋白或 desmoplakin（单核滋养细胞的细胞标志物）的抗体确认多核合胞体的存在或不存在。
多核合胞体的形成与 Twist 的增加和 E-钙黏蛋白表达的减少有关。同样，外源性表达 Twist 导致 E-钙黏蛋白表达的持续和渐进性下降，并随后在正常培养条件下培养的 BeWo 细胞中形成合胞体。相比之下，针对 Twist 的小干扰 RNA 特异性抑制了 8-Br-cAMP（8-溴腺苷 3'，5'-环单磷酸）介导的分化和融合。
在体外人滋养细胞系中，Twist 是 E-钙黏蛋白介导的终末分化和融合的上游调节剂。
