Research of endocrine regulation of the invasive potential and apoptosis extravillous trophoblasts

本研究旨在探讨早期胎盘绒毛外滋养层细胞是否存在T_3受体，以及T_3对培养的早期胎盘绒毛外滋养层细胞Fas/Fas配体表达、半胱氨酸天冬氨酸氨基转移酶-3和多聚腺苷二磷酸核糖聚合酶(PARP)裂解及细胞凋亡的影响。早期胎盘EVT表达212bpc-erb Aβ1转录本和T_3受体蛋白，并在培养中表现出显著的细胞凋亡水平。经T_3处理后，培养的EVT细胞Fas和Fas配体表达减少，caspase-3和PARP裂解减少，细胞凋亡受到抑制。结果表明，胎盘EVT早期存在T_3受体，T_3通过下调Fas和Fas配体的表达而抑制细胞凋亡。此外，为了探讨T_3在EVT侵袭蜕膜中的可能作用，我们检测了T_3是否影响EVT侵袭潜能以及培养的早期胎盘EVT中基质金属蛋白酶-2(MMP2)、MMP3、组织抑制因子金属蛋白酶-1、胎儿纤维连接蛋白(FN)和整合素α_5β_1的表达。Matrigel侵袭实验表明，T_3处理可显著增加培养的EVT的细胞投射数目。逆转录聚合酶链式反应结果显示，T_3处理后EVT细胞基质金属蛋白酶-2、基质金属蛋白酶-3、胎儿纤维连接蛋白和整合素α_5、β_1m RNA的表达增加。免疫细胞化学和免疫印迹分析显示，经T_3处理后，培养的EVT中MMP2和MMP3的表达增加。结果提示，T_3(10^~(-8)~(-8)~(-M))可能在上调EVT对蜕膜的侵袭潜能中起重要作用。

The present study was conducted to determine whether T_3 receptor exists in early placental extravillous trophoblasts (EVTs) and evaluate the influence of T_3 on Fas/Fas ligand expression, caspase-3, and poly (ADP-ribose) polymerase (PARP) cleavage and apoptosis in cultured early placental EVTs. Early placental EVTs expressed a 212-bp c-erb Aβ1 transcript and the T_3 receptor protein and exhibited significant levels of apoptosis in culture. Treatment with T_3 reduced the expression of Fas and Fas ligand as well as cleavage of caspase-3 and PARP and suppressed apoptosis in cultured EVTs. These results demonstrate that T_3 receptor is present in early placental EVTs and that T_3 suppresses apoptosis by down-regulating the expression of Fas and Fas ligand. Furthermore, in order to investigate the possible role of T_3 in the regulation of EVT invasion to the decidua, we have examined whether T_3 affects EVT invasive potential and the expression of matrix metalloproteinase-2 (MMP-2), MMP-3, tissue inhibitor metalloproteinase-1, fetal fibronectin (FN), and integrin α_5β_1 in cultured early placental EVTs. Matrigel invasion assay demonstrated that the treatment with T_3 significantly increased the number of cell projections of cultured EVTs. RT-PCR analysis revealed that the treatment with T_3 increased the expression of MMP-2, MMP-3, fetal FN, and integrin α_5β_1 mRNA in cultured EVTs. Immunocytochemical and Western immunoblot analysis revealed that treatment with T_3 increased the expression of MMP-2 and MMP-3 in cultured EVTs. The present results suggest that T_3 (10^<-8>_M) may play a vital role in up-regulating the invasive potential of EVTs into the decidua.