Expression of Na+/I- symporter and pendred syndrome genes in trophoblast cells
Expression of Na+/I- symporter and pendred syndrome genes in trophoblast cells
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DOI：
10.1210/jc.85.11.4367
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发表时间：
2000-11-01
影响因子：
5.8
通讯作者：
Schlumberger, M
中科院分区：
文献类型：
--
作者：
Bidart, JM;Lacroix, L;Schlumberger, M
胎盘碘转运对胎儿甲状腺功能至关重要，但这种转运的分子机制尚不清楚。最近发现的两种碘转运蛋白，即钠/碘同向转运蛋白（NIS）和pendrin（Pendred综合征（PDS）基因的产物）的表达，采用实时动态定量PCR和免疫组织化学方法研究了1）在不同胎龄收集的胎盘组织和2）在原代培养的绒毛细胞滋养层细胞（VCT）中，NIS和PDS基因在胎盘中表达，尽管与甲状腺组织相比表达水平较低。孕早期和足月妊娠胎盘样本中NIS基因表达相似。与此相反，PDS基因的表达是在长期高于在早期妊娠样品。在体外培养条件下，NIS基因在孕早期VCT中高水平表达，在VSCT中VCT分化过程中其表达下降3 ~ 4倍。NIS的表达是较低的（高达30倍），在VCT中获得的胎盘样本从孕晚期比孕早期。相比之下，PDS基因的表达是低的VCT和VSCT形成过程中增加了5至10倍，这是观察到的细胞分离的胎盘样本的头三个月和足月妊娠。免疫组化分析显示，NIS蛋白存在于整个膜的VCT，而pendrin主要位于刷状缘膜的VSCT，面对母亲。总之，1）NIS和PDS基因在妊娠期间的胎盘中表达不同; 2）pendrin在合体滋养层细胞的刷状缘膜上表达，而NIS蛋白主要位于细胞滋养层。
Placental iodide transport is critical for the fetal thyroid function, but the molecular mechanisms of this transport are not understood. The expression of two recently identified iodide transporters, namely the sodium/iodide symporter (NIS) and pendrin, the product of the gene responsible for the Pendred syndrome (PDS), was studied using real-time kinetic quantitative PCR and immunohistochemistry 1) in placental tissues collected at different gestational ages and 2) in primary cultures of villous cytotrophoblast cells (VCT) that differentiate and fuse over 2-3 days in vitro to form villous syncytiotrophoblast (VSCT) cells.Both NIS and PDS genes are expressed in placenta, albeit at low levels compared with those in thyroid tissue. NIS gene expression in placental samples from first trimester and term pregnancies was similar. In contrast, the expression of PDS gene was higher in term than in first trimester pregnancy samples. In vitro, NIS gene was expressed at a high level in VCT obtained from first trimester pregnancy, and its expression decreased by 3- to 4-fold during the differentiation of VCT in VSCT. Expression of NIS was lower (up to 30-fold) in VCT obtained in placental samples from third trimester than from first trimester pregnancy. In contrast, the expression of PDS gene was low in VCT and increased by 5- to 10-fold during VSCT formation; this was observed in cells isolated from placental samples of both first trimester and term pregnancies. Immunohistochemical analysis showed that NIS protein was present on the entire membrane of VCT, whereas pendrin was mainly located at the brush border membrane of VSCT, facing the mother. In conclusion, 1) NIS and PDS genes are differently expressed in the placenta during gestation; and 2)whereas pendrin is expressed at the brush border membrane of syncytiotrophoblast cells, NIS protein is mainly located in the cytotrophoblast layer.