The expression and localization of neutral endopeptidase 24.11/CD10 in human gestational trophoblastic diseases

Neutral endopeptidase 24.11 (NEP)/CD10 is a cell-surface peptidase that hydrolyzes various bioactive peptides. NEP is distributed in both normal and neoplastic cells and plays a functional role by modulating cellular responses to peptide substrates. Recently, NEP has been shown to be expressed in normal placental trophoblasts, suggesting its physiological role during pregnancy. In the present study, we investigated the expression of NEP in hyperplastic and anaplastic trophoblasts in gestational trophoblastic diseases (GTDs). Flow cytometric analysis demonstrated that NEP was expressed in all choriocarcinoma cell lines examined. The NEP enzyme activity in these cell lines correlated with cell-surface protein levels and was abolished by the NEP inhibitor phosphoramidon. On immunoblot analysis, NEP protein was detected in both hydatidiform mole and choriocarcinoma tissues as a double band of 95 and 100 kDa similar to that of the normal placental tissues. Immunohistochemical analysis revealed that NEP was present on syncytiotrophoblasts, while no or very faint NEP immunoreactivity was observed on cytotrophoblasts in the normal placenta. Similarly, NEP in hydatidiform mole and invasive mole was localized on the membrane of syncytiotrophoblasts, but not on hyperplastic cytotrophoblasts. In contrast, in choriocarcinoma, NEP was highly expressed not only on syncytiotrophoblastic cells but also on invading anaplastic cytotrophoblasts. In addition, NEP was also expressed on intermediate trophoblasts in placental site trophoblastic tumors. In summary, this is the first study demonstrating the expression of NEP/CD10 in GTDs. The differential localization of NEP among various trophoblastic tumors suggests that NEP may play a functional role in the regulation of trophoblast transformation and human chorionic gonadotropin secretion.     

自然流产患者绒毛滋养层细胞PCNA和caspase-3的表达

目的从细胞增殖与细胞凋亡的角度探讨自然流产的发生机制。方法取正常早孕流产和自然流产病例各20例的绒毛组织,光镜观察绒毛形态学变化;免疫组织化学SP法检测增殖细胞核抗原(PCNA)及凋亡蛋白酶caspase-3在滋养层细胞中的表达。结果自然流产绒毛组织均出现不同程度的退行性改变,细胞滋养层的增殖指数较对照组降低,而细胞滋养层、合体滋养层的凋亡指数却明显升高。结论凋亡蛋白酶caspase-3可能参与自然流产的发生机制。     

Analysis of the vascular profile and CD99 protein expression in the partial and complete hydatidiform moles using quantitative CD34 immunohistochemistry

BackgroundHydatidiform mole is a gestational trophoblastic disease with two different types: complete (CHM) and partial hydatidiform moles (PHM). The villous stroma of CHM is avascular or contains primitive endothelial-lined vascular elements. CD99 is a leukocyte antigen expressed in both normal and neoplastic tissue.ObjectivesTo examine the expression of CD99 and vascular profile in PHM and CHM compared to first trimester pregnancy termination (TOP).Materials and methodsFifty trophoblastic tissue specimens were immunostained using monoclonal antibodies decorating CD99 and CD34 antigens (vasculogenesis). CD99 expression and the vascular parameters were scored.ResultsIn CHM and PHM, the number of blood vessels with distinct lumens in the villous stroma (centrally and peripherally located) was significantly reduced (p < 0.05), compared to TOM. In CHM, the number of the centrally located hemangiogenetic cords was higher compared to TOP. No statistically significant differences were found between CHM and PHM. In chorionic villi of TOP, a strong CD99 reactivity was seen in the endothelial, decidual, fibroblastic and in trophoblastic cells (syncytiotrophoblasts and cytotrophoblasts). Weak to virtually absent CD99 reactivity was seen in the trophoblastic cells of chorionic villi with molar changes.ConclusionsVasculogenesis can be initiated in the molar pregnancies despite the absence of embryos or maternal derived chromosomes. CD99 may have a possible role in the development of molar changes.     

Trophoblastic tumors: ultrastructural comparison of choriocarcinoma and placental-site trophoblastic tumor

Ten trophoblastic tumors, including seven classical choriocarcinomas, two choriocarcinomas with atypical histology, and one placental-site trophoblastic tumor (PSTT), were studied to compare their fine structural features. Ultrastructurally, the classical choriocarcinomas showed well-defined cytotrophoblasts and syncytiotrophoblasts. The cytotrophoblasts were primitive epithelial cells, while the syncytiotrophoblasts were complex cells with multiple nuclei and dense cytoplasm containing dilated endoplasmic reticulum, lysosomes, vesicles, and tonofilaments. The syncytiotrophoblast cell membranes often contained numerous microvilli. In the choriocarcinomas, scattered intermediate trophoblasts showed features transitional between the cytotrophoblasts and the syncytiotrophoblasts, with moderately complex cytoplasm containing some of the organelles found in the syncytiotrophoblasts. Histologically, the atypical choriocarcinomas showed a predominance of mononucleate and binucleate cells and indistinct syncytiotrophoblasts. Ultrastructurally, these atypical tumors were composed largely of intermediate trophoblasts, yet contained scattered syncytiotrophoblasts with microvilli in compressed aggregates. The PSTT was composed primarily of intermediate trophoblasts that contained prominent paranuclear filaments not seen in the intermediate trophoblasts of the choriocarcinomas. Rare cells resembling syncytiotrophoblasts were found in the PSTT, but no cytotrophoblasts were observed. Immunoreactivity for human chorionic gonadotropin and human placental lactogen was found in the intermediate trophoblasts and syncytiotrophoblasts of both the choriocarcinomas and the PSTT, demonstrating functional homology between these tumors despite some ultrastructural differences. These results demonstrate ultrastructural features of trophoblastic cells that correlate with the morphologic diversity seen in these tumors by light microscopy. Furthermore, the comparisons suggest that the PSTT is composed of a distinct form of intermediate trophoblast that appears to reflect its origin from the extravillous trophoblast.     

子痫前期患者胎盘组织中visfatin蛋白与mRNA表达及意义

目的:探讨内脂素(visfatin,VF)在子痫前期(PE)患者胎盘组织中的表达及意义。方法:选择2011年8月至2013年12月在温州医科大学附属第一医院住院分娩的孕妇共计100例,根据病情轻重分为重度PE组、轻度PE组和正常妊娠组。采用苏木素-伊红染色法观察3组胎盘组织病理变化;免疫组化法及real-time PCR技术分别检测3组胎盘VF蛋白及mRNA的表达并分析其与子痫前期发病的关系。结果:PE的病理改变主要表现为细胞滋养细胞及合体滋养细胞结构紊乱且形态不完整;细胞滋养细胞增生,合体滋养细胞结节增多;绒毛毛细血管减少、淤血。免疫组化及real-time PCR结果显示胎盘组织中内脂素定位于合体及细胞滋养层细胞的胞浆,随着病情的加重,VF蛋白及mRNA表达量逐渐升高,重度PE组明显高于正常妊娠组,差异有统计学意义(P0.05)。结论:PE患者存在绒毛血管内皮细胞损伤和功能紊乱。胎盘VF蛋白及mRNA在PE孕妇中高表达,表明VF与PE的发生具有一定关系。     

Expression of functional chemokine receptors of human placental cells

PROBLEM: Chemokine receptors of placental trophoblasts possibly act as co-receptors or alternative receptors of maternal fetal infection by HIV. To clarify their possible expression and the physiological roles of chemokines on human placentae, we studied chemokine chemokine receptor expression and the effects of exogenous chemokines on choriocarcinoma cell lines. MATERIALS AND METHODS: Placental samples were obtained from 13 placentae of various gestational ages. Villous tissue was mechanically dissected from samples. Trophoblasts were enriched by anti-human chorionic gonadotropin (hCG)-coated magnetic beads. Human choriocarcinoma cell lines (JAR, BeWo, JEG-3) were maintained in RPMI 1640 media supplemented with 10% FCS. Expression of chemokine receptors was studied by RT-PCR. The effects of MIP-1alpha, RANTES, MCP-1 on hCG production were estimated by EIA. Effects of chemokines on proliferation of choriocarcinoma cell lines were examined by MTT assay. RESULTS: We observed mRNA expression of CCR-1, 2, 3, 4, 5 and CXCR-1, 2, 4 in 1st trimester placental villi, CCR-I, 2, 4 and CXCR-1, 2. 4 in 2nd trimester placental villi, CCR-1, 2, 4 and CXCR-4 in 3rd trimester placental villi. Using MACS enriched trophoblasts, we observed identical results. A choriocarcinoma cell line BeWo expressed CCR-1, 3, 4 and CXCR-1, 2, 4 while JEG-3 and JAR expressed CCR-1, 3, 4, 5 and CXCR-1, 2, 4. Expression of the CCR-5 and CXCR-4 protein in choriocarcinoma cell lines and MACS-enriched trophoblats were confirmed by flow cytometry. Chemokine MCP-3, MIP-1alpha, RANTES mRNA were expressed by the 1st, 2nd and 3rd trimester placental samples and the three choriocarcinoma cell lines examined. MCP-1 was expressed by 1st and 2nd trimester placental villi. Administration of chemokines up-regulated proliferation (10(-1) - 10 ng/mL) and hCG production (10(-1) - 10(-2)ng/ mL) of the three choriocarcinoma cell lines examined. CONCLUSIONS: Our results suggest possible roles of chemokines/chemokine receptors on placental physiology and their involvement in HIV transmission as alternative receptors.     

DEVELOPMENTAL REGULATION OF TISSUE TRANSGLUTAMINASE DURING HUMAN PLACENTATION AND EXPRESSION IN NEOPLASTIC TROPHOBLAST

The expression of tissue transglutaminase (tTG) was studied during the formation of the normal human placenta and in molar pregnancies and choriocarcinoma, in order to correlate its expression with the functional characteristics of the recognized trophoblast cell types. tTG expression was found to be developmentally regulated. Before 6–7 weeks' gestation, only the chorionic villous cytotrophoblast expresses tTG. Thereafter the overlying syncytiotrophoblast becomes positive. tTG expression is gradually downregulated in the intermediate trophoblast cells emerging from the tips of the chorionic villi invading the uterine tissue. In the decidual wall, the intermediate trophoblast does not express tTG, whereas scattered syncytial cells, the placental bed giant cells, express tTG. Villi from complete hydatidiform mole (CHM) show tTG expression in both the cyto- and the syncytiotrophoblast. The intermediate trophoblast cells from CHM show heterogeneous tTG expression, with a majority of negative cells, whereas extravillous syncytia always express tTG. In choriocarcinoma, the tumour cells show heterogeneous tTG expression, with a majority of positive cells. Analysis of tTG protein and mRNA in placental extracts by Western and Northern blotting did not provide evidence for expression of the truncated form of tTG found in some cell types. The regulated expression of tTG in the normal placenta suggests that the enzyme is involved in important trophoblastic functions and may participate in the control of invasion. © 1997 by John Wiley & Sons, Ltd.     

Characterization of human villous and extravillous trophoblasts isolated from first trimester placenta

Trophoblasts of the human placenta differentiate along two pathways to give either extravillous cytotrophoblasts (EVCT) with invasive properties and that are implicated in the implantation process, or villous cytotrophoblasts (VCT) that by cell fusion form multinucleated syncytiotrophoblasts. We report the first isolation and purification of these two cell types from the same chorionic villi of first trimester human placenta. We also studied their differentiation in vitro. Electron microscopy showed that in contrast to VCT, EVCT had no microvilli but contained large fibrinoid inclusions. EVCT cultures required a matrix to invade, and as previously established, VCT cultured on plastic dishes aggregated and fused to form syncytiotrophoblasts. These differentiation processes were characterized by a particular pattern of gene expression as assessed by real-time PCR and confirmed by immunocytochemical analysis of the corresponding proteins. EVCT cultured in vitro expressed high levels of HLA-G, c-erbB2, human placental lactogen, and very little human chorionic gonadotropin. Interestingly, TGFbeta2 was a marker of EVCT in vitro and in situ. These data offer a new tool for cell biologists to study the molecular mechanisms involved in human placental development and its pathology.     

P57和Ki-67在葡萄胎鉴别诊断中的作用

目的:探讨P57和Ki-67蛋白在完全性和部分性葡萄胎鉴别诊断中的作用.方法:分别收集正常胎盘绒毛、部分性葡萄胎和完全性葡萄胎石蜡标本各12例,应用免疫组织化学方法检测P57和Ki-67蛋白在这些病变中的分布及表达水平.结果:P57蛋白在正常绒毛及部分性葡萄胎组织中主要分布于绒毛的细胞滋养叶细胞及间质细胞,两组间阳性率...     

Human migrating extravillous trophoblasts express a cell surface peptidase, carboxypeptidase-M

We previously reported that a cell-surface aminopeptidase, dipeptidyl peptidase IV, is expressed on extravillous trophoblasts (EVT) and suggested the involvement of its enzyme activity in EVT migration. In this study, we examined the expression of another cell-surface peptidase, carboxypeptidase-M (CP-M), at human embryo implantation sites, which catalyses biologically active peptides at extracellular sites. CP-M was immunohistochemically detected on syncytiotrophoblast, but not on cytotrophoblasts in floating chorionic villi (9-12 weeks of gestation). At villus-anchoring sites, CP-M was weakly detected on some EVT in the distal part of the cell column. CP-M was clearly expressed on EVT in the trophoblastic shells and in the maternal vessels. In the decidua, almost all interstitial trophoblasts expressed CP-M. Flow cytometry and RT-PCR showed that CP-M expression was induced on the outgrown EVT in primary villous explant culture. The CP-M induction on cultured EVT under 20% O(2) concentration was significantly higher than that under 1% O(2) concentration. In invasion assays, migration of JEG-3 cells, a CP-M-bearing human choriocarcinoma cell line, was significantly enhanced by an inhibitor of CP-M, DL-mercaptomethyl-3-guanidino-ethyltiopropanoic acid (MGTA). These findings indicate that CP-M is a differentiation-related molecule for human EVT and suggest that CP-M expression on EVT is partially regulated by tissue oxygen concentration.     

人早期胎盘绒毛运动神经诱向因子1及其受体的免疫组织化学定位

为了解人胎盘绒毛是不存在运动神经诱向因子及其可能的功能意义，本实验用ＭＮＴＦ１单克隆抗体及抗独特型单克隆抗体在人早期胎盘绒毛石蜡切片上进行免疫组织化学反应，对人早期胎盘绒毛的ＭＮＴＦ１及其受体进行定位。结果显示，胎盘绒毛的细胞滋养层细胞，合体滋养层细胞和基质细胞均呈ＭＮＴＦ１强免疫反尖，ＭＮＴＦ１样免疫反应物质分布在胞质内，胞核内阴性。     

Promyelocytic leukaemia (PML) protein expression in human placenta and choriocarcinoma

Promyelocytic leukaemia (PML) protein, the product of the pml gene, is heterogeneously expressed in various normal and neoplastic tissues, and the fusion of the pml gene with retinoic acid receptor-alpha is believed to be a central mechanism in acute PML tumourigenesis. As PML is important for controlling major cellular processes, such as growth and differentiation, it is believed that it plays an important role during human gestation. The human placenta is a critical organ for the maintenance of gestation, but the expression pattern and functional significance of PML in the placenta have not been documented. The present study has therefore investigated the expression of PML in the human placenta and in choriocarcinoma, and has observed the biological effects following the overexpression of PML in choriocarcinoma cell lines (BeWo and JEG-3). In the human placenta, PML expression was readily found in villous stromal fibroblasts, capillary endothelial cells, Hofbauer cells, and occasionally in amnion cells. Moreover, immunoblotting of placental lysates demonstrated increased PML expression with increasing gestation. Interestingly, PML expression was confined to intermediate trophoblasts and syncytiotrophoblastic giant cells at the placental site (placental site giant cells) in the trophoblastic cell population. Intermediate trophoblasts at non-placental sites, and villous cytotrophoblasts and syncytiotrophoblasts consistently did not express PML. Further screening of PML expression in hydatidiform moles (n = 4) and choriocarcinomas (n = 7) also revealed selective PML expression in intermediate trophoblastic cells and syncytiotrophoblastic cells, but not in the cytotrophoblastic populations, which corresponds well with observations in the placental bed. Adenoviral transduction of PML resulted in a marked reduction in cell growth in both choriocarcinoma cell lines, which was associated with increased apoptosis. The findings of the present study strongly suggest that PML plays an important role in human placental development and growth, and in the pathobiology of trophoblasts and trophoblastic neoplasia.     

Effect of maternal age on incidences of apoptotic and proliferative cells in trophoblasts of full-term human placenta.

Advanced maternal age is known to be a risk factor for various kinds of obstetric complications, including placental dysfunction. As a first step towards determining the maternal age-related changes in placental, as well as trophoblastic function, we examined the incidences of apoptotic and proliferative cells in trophoblasts of placentae from women of various ages using the TUNEL method and immunohistochemistry for Ki-67 antigen. Tissue sections were collected from the placentae of healthy mothers with normal delivery of healthy babies so that the placental cell kinetics maintaining normal pregnancy and delivery could be studied. The TUNEL-positive cells of the placenta were syncytiotrophoblasts with clustering of nuclei and the TUNEL-positive index of these cells varied from 0.28-1.2%. This index revealed a significant inverse correlation with maternal age. In contrast, the Ki-67-positive index of mononuclear trophoblasts of the placenta ranged between 1.2-2.8% and showed a positive correlation with maternal age. Many of the apoptotic cells of placental villi expressed the pro-apoptotic Bak protein, but were negative for expression of the anti-apoptotic Bcl-2 protein. These results suggest that trophoblasts have higher proliferative activity in older mothers, with a normal process of pregnancy and delivery. The Bcl-2 family proteins could be important for the regulation of trophoblastic apoptosis, although the cellular and molecular mechanisms mediating maternal age-related changes of the placenta remain to be determined.     

Nuclear beta-catenin expression is rare and its potential association with short survival in colorectal signet-ring cell carcinoma.

Colorectal signet-ring cell carcinoma (SRCC) is a rare cancer and the prognosis is usually very poor. The biologic pathways involved in its oncogenesis are unknown. beta-catenin, a key target in the Wnt-signaling pathway, is recognized to play an important role in the carcinogenesis in conventional colorectal carcinoma. This study explores the involvement of Wnt-signaling molecules beta-catenin and cyclin D1, cell cycle regulators cyclin D3, proliferative index Ki-67, apoptotic index, and angiogenic indicator CD31 in 20 colorectal SRCC paraffin-embedded specimens. Results showed that there were 2 specimens with nuclear beta-catenin and higher expression of cyclin D1 than the remaining 18 specimens. Surprisingly, those 2 patients had a much shorter survival of 6 months than the remaining 15 patients, who had around 24 months. Moreover, all colorectal SRCC specimens had an overexpression of cyclin D1, cyclin D3, and Ki-67, as well as much more angiogenesis and apoptosis than adjacent normal epithelial tissues. The authors make the preliminary comment that nuclear beta-catenin is a rare phenomenon in colorectal SRCC, but the involvement of it may indicate a worse prognosis with shorter survival than colorectal SRCC without nuclear beta-catenin expression. Besides, overexpression of cyclin D1, cyclin D3, Ki-67, and increased angiogenesis and apoptosis may play a vital role in promoting colorectal SRCC development.     

Intraplacental choriocarcinoma with fetomaternal transfusion

Intraplacental choriocarcinoma is very rare, and is usually found only after maternal and fetal metastatic disease is identified. The purpose of this case report is to review the incidence and findings of intraplacental choriocarcinoma. A term placenta was investigated because the newborn was born with severe anemia (Hb 3.0 g/dL). A 2 cm nodule was noted on the surface of the amniotic membrane and grossly resembled an infarction. The tumor was examined microscopically with immunohistochemical staining for the alpha- and beta-human chorionic gonadotropin (alpha-hCG, beta-hCG) subunits, human placental lactogen (hPL) and Ki-67. Microscopically, the tumor consisted of necrotic areas with proliferation of atypical trophoblastic cells and destruction of the villi and capillaries. The cells were positive for the alpha-hCG, beta-hCG subunits, hPL and Ki-67, consistent with intraplacental choriocarcinoma. The mother and newborn were investigated for the presence of metastatic disease. Computed tomography scans and magnetic resonance imaging of the mother and infant were negative for metastatic disease. Choriocarcinoma, limited only to the placenta with no evidence of metastatic disease is very rare. Primary intraplacental choriocarcinoma may frequently be overlooked or missed, and choriocarcinoma may possibly arise in the placenta more often than in retained or persistent trophoblast following pregnancy.     

p57和p53蛋白在水肿性流产及葡萄胎鉴别诊断中的作用

目的探讨p57和p53蛋白在水肿性流产、完全性和部分性葡萄胎鉴别诊断中的作用。方法分别收集正常绒毛、水肿性流产、部分性葡萄胎和完全性葡萄胎石蜡标本10、12、23和20例,应用免疫组织化学EnVision法检测p57和p53蛋白在这些组织中的分布及表达水平。结果p57蛋白在正常绒毛、水肿性流产及部分性葡萄胎组织中主要分布于绒毛的细胞滋养细胞及间质细胞,阳性表达比例分别为10/10、12/12和100％( 23/23),各组间相比差异无统计学意义(P＞0.05)。在完全性葡萄胎中细胞滋养细胞及间质细胞p57表达缺失,与部分性葡萄胎相比,差异有统计学意义(P＜0.05)。p53蛋白主要表达于完全性和部分性葡萄胎的细胞滋养细胞及中间滋养细胞。在正常绒毛中p53蛋白呈阴性表达,水肿性流产中仅1例p53蛋白呈阳性表达(1/12),部分性葡萄胎和完全性葡萄胎中p53蛋白的阳性率分别为60.9％( 14/23)和85.0％ (17/20);p53蛋白的阳性率,部分性葡萄胎较水肿性流产明显增加,完全性葡萄胎较部分性葡萄胎也明显增加,差异均有统计学意义(均P ＜0.05)。结论p57蛋白免疫组织化学检测可辅助鉴别完全性和部分性葡萄胎,而p53蛋白的检测则有助于鉴别水肿性流产和部分性葡萄胎。     

Expression of placental leucine aminopeptidase and adipocyte-derived leucine aminopeptidase in human normal and malignant invasive trophoblastic cells

We recently identified two novel aminopeptidases, placental leucine aminopeptidase (P-LAP) and adipocyte-derived leucine aminopeptidase (A-LAP). Enzymatically, P-LAP degrades oxytocin, vasopressin, and angiotensin III, while A-LAP degrades angiotensin II and kallidin. In this study we investigated the expression and localization of P-LAP and A-LAP in human trophoblastic cells in the normal placenta (n = 26), gestational choriocarcinoma (n = 8), and placental site trophoblastic tumor (n = 3). On immunoblot analysis both P-LAP and A-LAP proteins were detected in normal placenta and five choriocarcinoma tissues, as well as in two choriocarcinoma cell lines. Immunohistochemical staining of normal placental tissues demonstrated that P-LAP was not only localized in villous syncytiotrophoblasts but also highly expressed in extravillous trophoblasts (EVTs) invading the decidua or maternal spiral arteries. The expression level of P-LAP on these invasive EVTs reached a maximum during the late first to second trimesters of pregnancy, and it decreased in the third trimester. Similarly, A-LAP was strongly expressed in EVTs invading the decidua or spiral arteries in the second trimester of pregnancy, while it was weakly or moderately expressed in villous cytotrophoblasts or EVTs located in the cell columns. These two aminopeptidases were more strongly expressed in all eight choriocarcinomas and three placental site trophoblastic tumors and mainly localized to the intermediate-type trophoblastic tumor cells invading the uterine myometrium or stromal vessels. In summary P-LAP and A-LAP were predominantly expressed in the invasive phenotype of EVTs during placentation, as well as in the invasive tumor cells of trophoblastic neoplasms. These results suggest the involvement of these aminopeptidases in invasiveness of both normal and malignant intermediate-type trophoblasts possibly through degradation of specific peptide substrates.