Role of HERV-W Syncytin-1 in Placentation and Maintenance of Human Pregnancy
Role of HERV-W Syncytin-1 in Placentation and Maintenance of Human Pregnancy
复制标题
DOI：
10.1097/pai.0b013e31819640f9
复制
发表时间：
2009-07-01
影响因子：
1.6
通讯作者：
Bagasra, Omar
中科院分区：
文献类型：
--
作者：
Noorali, Samina;Rotar, Ioana C.;Bagasra, Omar
超过一半的人类基因组含有逆转录元件，包括逆转录转座子、逆转录病毒和其他元件。人内源性逆转录病毒（HERV）约占人类基因组的8%。在16个已鉴定的HERV-W基因中，有2个基因的产物在胎盘形成过程中起关键作用。这2个基因是HERV-W env糖蛋白（合胞素-1）和HERV-FRD env糖蛋白（合胞素-2）。先前已经表明，合胞素-1介导细胞滋养层到合胞体滋养层的细胞-细胞融合。此外，HERV-W em含有免疫抑制区域，其可防止母亲免疫系统对半同种异体胎儿的排斥。我们分析了40个足月胎盘组织定位syncytin-1-ISR的表达，免疫组化染色和逆转录酶（RT）原位聚合酶链反应（PCR）。免疫组化和原位RT-PCR均显示，在足月胎盘组织的合体滋养层中，syncytin-1有强表达。为了进一步分析早期胚胎HERV-Wem激活的机制，我们利用了从第一个三个月的人滋养层发育的HTR-8/SVneo细胞系，并使θ经受各种生理浓度的母体激素。定量RT-PCR分析表明，暴露于孕酮显着上调HERV-W env的表达，而其他几种激素显然发挥较小的作用。总之，我们的研究结果表明，表达合胞体蛋白-1（HERV-W env）在子宫内只表达在合胞体滋养层，并上调孕激素。
Over half of human genome contains retroelements, including retrotransposons, retroviruses, and other elements. Human endogenous retroviruses (HERVs) comprise about 8% of human genome. The products of 2 of 16 identified genes of HERV-W seem to play a pivotal role in the placentation. These 2 genes are HERV-W env glycoprotein (syncytin-1) and HERV-FRD env glycoprotein (syncytin-2). It has been shown previously that syncytin-1 mediates cell-cell fusions of cytotrophoblasts into syncytiotrophoblasts. In addition, HERV-W em, contains an immunosuppressive region that may prevent rejection of a semiallogenic fetus from the mother's immune system. We analyzed 40 full-term placental tissues to localize the expression of syncytin-1-ISR by immunohistochemical staining and by reverse trancscriptase (RT) in situ polymerase chain reaction (PCR). Both the immunostaining and in situ RT-PCR showed strong expression of syncytin-1 in the syncytiotrophoblast layer from the full-term placental tissues. To further analyze the mechanism of early embryo HERV-W em, activation, we utilized a HTR-8/SVneo cell line developed from first trimester human trophoblasts and subjected theta to various physiologic concentrations of maternal hormones. Quantitative RT-PCR analyses demonstrated that exposure to progesterone significantly upregulated the HERV-W env expression, whereas several other hormones apparently played lesser roles. In conclusion, our findings suggest that expression of syncytin-1 (HERV-W env) in utero is expressed exclusively in the syncytiotrophoblast layer and is upregulated by progesterone.