Expression of Gadd45α in human early placenta and its role in trophoblast invasion.

Well-controlled trophoblast migration and invasion at the maternal-foetal interface are crucial events for normal placentation and successful pregnancy. Growing evidence has revealed that growth arrest and DNA damage-inducible 45 alpha (Gadd45α) participates in tumour migration and invasion as a tumour suppressor. However, the expression and function of Gadd45α in trophoblasts is unknown. This study aimed to determine the Gadd45α expression and function in the human first trimester placenta and identify the underlying mechanisms. The expression of Gadd45α in human first trimester placenta was determined using immunohistochemistry. HTR8/SVneo cell line was used to investigate the effects of Gadd45α on proliferation, apoptosis, migration/invasion, matrix metalloproteinase (MMP)2/9 activities, and tissue inhibitor of metalloproteinase (TIMP)1/2 expression using cell proliferation assays, flow cytometric analysis, transwell migration/invasion assays, gelatin gel zymography, and western blotting, respectively. Moreover, a placental villous explant model was employed to verify its functions in placentation. Gadd45α was strongly expressed in syncytiotrophoblasts and trophoblast columns of human placental villi, extravillous trophoblast cells and glandular epithelium within the maternal decidua. Gadd45α knockdown significantly promoted migration and invasion of HTR8/SVneo cells, whereas it did not affect cell proliferation or apoptosis. Silencing Gadd45α also enhanced trophoblast outgrowth and migration in placental explants. These effects were related to increased activities of MMP2/9 and the decreased expression of TIMP1/2. Gadd45α may be involved in human trophoblast migration and invasion and may function as an important negative regulator at the foetal-maternal interface during early pregnancy by directly or indirectly regulating MMP2/9 activities.

Liu X ，Mu H ，Luo X ，Xiao X ，Ding Y ，Yin N ，Deng Q ，Qi H ... -  《-》

N-acetylglucosaminyltransferase V inhibits the invasion of trophoblast cells by attenuating MMP2/9 activity in early human pregnancy.

The invasion and migration of trophoblast cells are essential steps of normal placentation and successful pregnancy. The process is well-regulated by many factors at the fetal-maternal surface. Inadequate invasion by trophoblast cells may lead to poor perfusion of the placenta or complications such as preeclampsia (PE). Accumulating evidence suggests that N-acetylglucosaminyltransferase V (MGAT5) is correlated with tumor invasion and metastasis. Our objective was to characterize MGAT5 expression and function during placental development. The expression of MGAT5 in humans in placental tissue from the first trimester was determined by immunohistochemistry. To investigate whether MGAT5 regulates trophoblast invasion and migration, we investigated invasion/migration of the HTR8/SVneo trophoblast cells and used human villous explants. Cell proliferation and apoptosis were measured by CCK-8 assay and flow cytometry, respectively. The activity of matrix metalloproteinase (MMP) 2/9, and the expression of tissue inhibitors of metalloproteinases (TIMPs) 1/2 were determined by gelatin zymography and Western blot, respectively. MGAT5 was specifically localized within the cytotrophoblast, the syncytiotrophoblast and the trophoblast columns of human placental villi, decidual cells and some extravillous cells in the maternal decidua. MGAT5 shRNA significantly enhanced the invasion and migration capability of HTR8/SVneo cells, and increased villous explant outgrowth but did not affect proliferation and apoptosis of the trophoblast. The enhanced effect of MGAT5 shRNA on trophoblast cell invasion was associated with increased gelatinolytic activity of MMP2/9 and decreased expression of TIMP1/2. Our data support a role for MGAT5 in the inhibition of human trophoblast cell invasion and migration during early pregnancy by direct or indirect regulation of MMP2/9 activity.

Deng Q ，Chen Y ，Yin N ，Shan N ，Luo X ，Tong C ，Zhang H ，Baker PN ，Liu X ，Qi H ... -  《-》

The chemokine CXCL6 restricts human trophoblast cell migration and invasion by suppressing MMP-2 activity in the first trimester.

Can the chemokine CXCL6 affect trophoblast cell migration and invasion in human first-trimester placenta? Chemokine CXCL6 inhibits trophoblast cell migration and invasion by suppressing matrix metalloproteinase (MMP)-2 activity in human first-trimester placenta. Several chemokines including CXCL8, CXCL12, CXCL14, CXCL16, CX3CL1, CCL14 and CCL4 can promote or inhibit trophoblast cell migration and invasion in human first-trimester placenta. We used the trophoblast cell line HTR8/SVneo cells, primary trophoblast cells and villi explants to investigate the effect of rhCXCL6 on trophoblast cell migration and invasion. First, the CXCL6 RNA transcript level was detected in HTR8/SVneo cells derived from human first-trimester, second-trimester and third-trimester placenta by RT-PCR. Protein expression of CXCL6 and its receptors was tested in first-trimester placenta by immunohistochemistry. Secreted CXCL6 protein was detected in HTR8/SVneo cell supernatants by enzyme-linked immunosorbent assay. Secondly, the effect of rhCXCL6 on HTR8/SVneo cell proliferation was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Thirdly, the effect of rhCXCL6 on cell migration and invasion of HTR8/SVneo cells, primary trophoblast cells and villi explants was tested by transwell migration and invasion assays, respectively. Last, MMP-2 and MMP-9 activity in the supernatants of HTR8/SVneo and primary trophoblast cells treated by rhCXCL6 in the invasion assay was assessed by gelatin zymography. Abundance of the CXCL6 RNA transcript increased with pregnancy development. CXCL6 and its receptor were expressed in several cells at the human maternal-fetal interface. RhCXCL6 inhibited trophoblast cell migration and invasion by suppressing MMP-2 activity. These experiments are only in vitro. According to the literature, CXCL6 could promote tumour cell migration and invasion by accelerating MMP-9 activity. However, CXCL6 inhibited trophoblast cell migration and invasion by suppressing MMP-2 activity in human first-trimester interface. These data suggest that strict regulation of CXCL6 is required for normal migration and invasion of cells, such as those involved at the maternal-fetal interface.

Zhang H ，Hou L ，Li CM ，Zhang WY ... -  《-》

Expression of N-Acetylglucosaminyltransferase III Promotes Trophoblast Invasion and Migration in Early Human Placenta.

Trophoblast migration and invasion at the maternal-fetal interface are crucial events for normal placentation and successful pregnancy. This progress is well controlled by many placenta-specific factors. Inadequate trophoblast invasion results in poor placenta plantation or even complications such as preeclampsia. It has been shown that N-acetylglucosaminyltransferase III (GnT-III) participates in tumor invasion and metastasis as a suppressor; however, the expression of GnT-III and its role in normal pregnancy is unclear. Our objective was to characterize GnT-III expression and function during placental development and identify the underlying mechanisms. The expression of GnT-III in human placental tissue from the first trimester was determined by immunohistochemistry. The HTR8/SVneo cell line was used to investigate the effects of GnT-III on proliferation, apoptosis, migration/invasion, matrix metalloproteinase (MMP) 2/9 activity, and the expression of the tissue inhibitor of metalloproteinase (TIMP) 1/2 using cell 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays, flow cytometric analysis, transwell migration/invasion assays, gelatin zymography, and Western blot, respectively. Moreover, a placental villous explant model was employed to determine its functions in placentation. In the first-trimester placental tissue, GnT-III was localized within the cytotrophoblast, the syncytiotrophoblast and the trophoblast columns of human placental villi, decidual cells, and some extravillous cells in the maternal decidua. GnT-III silencing significantly inhibited HTR8/SVneo cell invasion and migration as well as extravillous explant outgrowth. The application of GnT-III siRNA significantly attenuated MMP2/9 activity and increased TIMP1/2 expression. GnT-III is expressed in trophoblasts during normal human pregnancy and is involved in regulating trophoblast function.

Deng Q ，Liu X ，Yang Z ，Xie L ... -  《-》

The cytokine gene CXCL14 restricts human trophoblast cell invasion by suppressing gelatinase activity.

Well-controlled trophoblast invasion into uterine decidua is a critical process for the normal development of placenta, which is tightly regulated by various factors produced within the trophoblast-endometrial microenvironment. CXCL14 is involved in tumor growth and metastasis, and its expression in placenta is temporally regulated during pregnancy. However, the role of CXCL14 in trophoblast function during human pregnancy is not clear. In this study, by using RT-PCR through human pregnancy, we found that CXCL14 was selectively expressed at early but not late pregnancy. Immunostaining revealed that CXCL14 proteins were strongly expressed in villous cytotrophoblasts and moderately in decidualized stromal cells but very weakly in syncytiotrophoblasts and extravillous trophoblasts. The effect of CXCL14 on trophoblast invasion were examined by using human villous explants cultured on Matrigel and further proved by invasion and migration assay of primary trophoblast cells and trophoblast cell line HTR-8/SVneo. Our data showed that CXCL14 significantly inhibited outgrowth of villous explant in vitro; this effect is due to suppression of trophoblast invasion and migration through regulating matrix metalloproteinases activities, whereas the trophoblast proliferation was not affected. Moreover, because a receptor for CXCL14 has not been identified, we performed further cell-specific CXCL14 binding activities with regard to different cell types within the maternal-fetal interface. Our data revealed that CXCL14 could specifically bind to trophoblast cells but not decidual cells from the maternal-fetal interface. These results suggest that CXCL14 plays an important role in regulating trophoblast invasion through an autocrine/paracrine manner during early pregnancy.

Kuang H ，Chen Q ，Zhang Y ，Zhang L ，Peng H ，Ning L ，Cao Y ，Duan E ... -  《-》