Normal First-trimester Placenta Research Articles

Proteome profiling of human placenta reveals developmental stage-dependent alterations in protein signature

IntroductionPlacenta is a complex organ that plays a significant role in the maintenance of pregnancy health. It is a dynamic organ that undergoes dramatic changes in growth and development at different stages of gestation. In the first-trimester, the conceptus develops in a low oxygen environment that favors organogenesis in the embryo and cell proliferation and angiogenesis in the placenta; later in pregnancy, higher oxygen concentration is required to support the rapid growth of the fetus. This oxygen transition, which appears unique to the human placenta, must be finely tuned through successive rounds of protein signature alterations. This study compares placental proteome in normal first-trimester (FT) and term human placentas (TP).MethodsNormal human first-trimester and term placental samples were collected and differentially expressed proteins were identified using two-dimensional liquid chromatography-tandem mass spectrometry.ResultsDespite the overall similarities, 120 proteins were differently expressed in first and term placentas. Out of these, 72 were up-regulated and 48 were down-regulated in the first when compared with the full term placentas. Twenty out of 120 differently expressed proteins were sequenced, among them seven showed increased (GRP78, PDIA3, ENOA, ECH1, PRDX4, ERP29, ECHM), eleven decreased (TRFE, ALBU, K2C1, ACTG, CSH2, PRDX2, FABP5, HBG1, FABP4, K2C8, K1C9) expression in first-trimester compared to the full-term placentas and two proteins exclusively expressed in first-trimester placentas (MESD, MYDGF).ConclusionAccording to Reactome and PANTHER softwares, these proteins were mostly involved in response to chemical stimulus and stress, regulation of biological quality, programmed cell death, hemostatic and catabolic processes, protein folding, cellular oxidant detoxification, coagulation and retina homeostasis. Elucidation of alteration in protein signature during placental development would provide researchers with a better understanding of the critical biological processes of placentogenesis and delineate proteins involved in regulation of placental function during development.

Senescent Changes and Endoplasmic Reticulum Stress May Be Involved in the Pathogenesis of Missed Miscarriage.

BackgroundSenescence is involved in many complications of pregnancy. However, whether senescent changes are also associated with missed miscarriage has not been fully investigated.MethodsThe levels of p16, p21, and γH2AX, markers of senescence, were measured in placentas collected from women with missed miscarriage by immunohistochemistry and Western blotting. Levels of misfolded proteins in missed miscarriage placentas or normal first-trimester placenta that had been treated with H2O2 (100 μM) or extracellular vesicles (EVs) collected from missed miscarriage placental explant culture were measured by fluorescent compound, thioflavin-T. The production of reactive oxygen species (ROS) by missed miscarriage placentas was measured by CellROX® Deep Red.ResultsIncreased levels of p16, p21, and γH2AX were presented in missed miscarriage placentas compared to controls. Increased levels of misfolded proteins were shown in missed miscarriage placentas, but not in EVs that were collected from missed miscarriage placentas. The ROS production was significantly increased in missed miscarriage placental explant cultures. Increased levels of misfolded proteins were seen in the normal first-trimester placenta that had been treated with H2O2 compared to untreated.ConclusionOur data demonstrate that there are increases in senescence and endoplasmic reticulum stress and ROS production in missed miscarriage placenta. Oxidative stress and an accumulation of misfolded proteins in missed miscarriage placentas may contribute to the changes of senescence and endoplasmic reticulum stress seen in missed miscarriage placentas.

Expression pattern Nanog is associated with the development of gestational trophoblastic neoplasia in Chinese women from Fujian province: a case-control study

Background Gestational trophoblastic disease (GTD) is a group of interrelated but distinct diseases and has a serious impact on the reproductive health of women. To analyze the expression of Nanog in GTD and to evaluate its potential to predict the development of gestational trophoblastic neoplasia (GTN). Methods The study included 41 normal first-trimester placentas matched by gestational age to 53 regressed-hydatidiform-moles (rHMs), 56 malignant-HMs (mHMs) and 17 choriocarcinomas (CCAs) and evaluated the Nanog expression by immunohistochemistry. The chi-square test, ANOVA, Fisher’s exact test and logistic regression were performed to assess the Nanog expression and clinical prognostic factors in GTD. Results Compared to normal placenta levels, the Nanog expression was increased in GTD samples (p < .05). In HMs, Nanog expression was positively correlated with serum β-hCG levels,uterine size and theca-lutein cysts (p < .05). Compared with the low-risk metastatic group (Federation of Gynecology and Obstetrics (FIGO) score ≤ 6), the high-risk metastatic group (FIGO score >7) had higher Nanog expression (p = .030). Moreover, logistic regression analysis showed that the positive expression of Nanog had the highest risk of developing into GTN (OR = 4.764, p < .001). Conclusions Nanog is an independent predictor of clinical outcomes. It can also be a reliable predictor for GTN development from GTD.

P-21-Activated kinase-1, -4 and -6 and estrogen receptor expression pattern in normal placenta and gestational trophoblastic diseases

ObjectivesTo delineate the potential role of p21-activated kinases (PAKs) in the pathogenesis of gestational trophoblastic diseases (GTD) by defining the expression pattern of PAK-1, -4 and -6 and their potential implication in estrogen receptor (ER) regulation of normal placental tissue and GTD. MethodsWe evaluated immunohistochemically 10 normal first-trimester placentas (NP), 10 partial moles (PM), 15 complete moles (CM) and 3 choriocarcinomas (CCA) for PAK-1, PAK-4, PAK-6 and ER expression intensity and localization. Staining outcomes were assessed utilizing non-parametric Kruskal–Wallis one-way analysis of variance test followed by pairwise Wilcoxon Rank Sum tests. Statistical significance was determined by two-sided p-value of <0.05. ResultsIn NP, PAK-6 immunoreactivity was predominantly cytoplasmic. Compared to NP, PM and CM demonstrated significant increase of cytoplasmic PAK-6 in cytotrophoblast (p=0.012, p=0.033 respectively), accompanied by significantly increased nuclear immunoreactivity in cytotrophoblast (p=0.008, p=0.045 respectively) and intermediate trophoblast (p=0.003, p=0.015 respectively). PAK-4 was found significantly upregulated in both cytoplasmic and nuclear compartments of cytotrophoblast and syncytiotrophoblast in PM (p=0.004 and p=0.002 for cytotrophoblast; p=0.018 and p=0.002 for syncytiotrophoblast, respectively) and CM (p=0.001 and p=0.001 for cytotrophoblast; p=0.002 and p=0.001 for syncytiotrophoblast, respectively) when compared to NP, whereas PAK-1 expression was significantly reduced in the syncytiotrophoblast of PM (p=0.025 for cytoplasm and p=0.008 for nucleus). Nuclear expression of ER was undetectable in all stained samples. ConclusionOur results reveal PAK-6 upregulation in GTD compared to NP. The absence of nuclear expression of ER might stem in part from the repressive effect of PAK-6 in trophoblastic tissue.

Matrix metalloproteinases and their inhibitors and inducer in gestational trophoblastic diseases and normal placenta

Objectives This study aimed to investigate the expression of recently identified matrix metalloproteinases (MMPs), their inhibitors (TIMPs), and inducer (CD147) in a wide range of gestational trophoblastic diseases (GTD) thereby expanding our understanding of the potential role of MMPs in GTD. Methods Paraffin sections of 10 normal first-trimester placentas (NP), 10 partial moles (PM), 10 complete moles (CM), 5 choriocarcinomas (CCA) and 5 placental site trophoblastic tumors (PSTT) were studied immunohistochemically for expression of MMP-7, MMP-14, MMP-21, MMP-28, TIMP-3, TIMP-4 and CD147. Immunolocalization of MMP-1, MMP-2, MMP-3, MMP-9, MMP-13 and TIMP-1 was performed on 5 CCA and 5 PSTTs. Results CCA showed stronger intensity for MMP-14 and MMP-28 than PSTT ( p < 0.05, p < 0.05). CCA and PSTT had stronger expression of MMP-21 than NP, PM and CM ( p < 0.05, p < 0.05, p < 0.01). PSTT ( p < 0.05, p < 0.05), NP ( p < 0.01, p < 0.01) and CM ( p < 0.01, p < 0.05) showed stronger staining for TIMP-3 and TIMP-4 than CCA. Conclusion Choriocarcinoma's high expression of MMPs and low expression of MMP inhibitors may contribute to its invasiveness and metastatic potential. Similarly, PSTT's lower expression of MMPs and high expression of MMP inhibitors may partly explain its lower invasiveness. Agents that inhibit MMP may prove useful in treating GTD.

Expression of laminin receptor 1 in gestational trophoblastic diseases and normal placenta and its relationship with the development of postmolar tumors

Objectives To investigate the expression of laminin receptor 1 (LR1), a non-integrin-type laminin receptor, in gestational trophoblastic diseases and normal first-trimester placenta, since it may play a role in controlling trophoblast invasion in normal and molar pregnancies. Methods Paraffin sections from 24 gestational age controlled normal first-trimester placentas, 47 partial moles, 56 complete moles, 3 invasive moles, 4 gestational choriocarcinomas, and 1 placental-site trophoblastic tumor were studied immunohistochemically for expression of LR1. Results In complete and partial moles, decidual cells showed significantly stronger LR1 protein staining compared to the normal placenta ( p < 0.01). When compared to the partial moles, weak staining in less than 33% of decidual cells was also more prominent in the normal placenta ( p < 0.05). Complete and partial moles, invasive moles, choriocarcinomas, and placental-site tumors did not differ from each other with respect to staining intensity. Strong immunostaining for LR1 in decidual cells, cytotrophoblasts, syncytiotrophoblasts, and extracellular matrix cells of partial and complete moles was not significantly correlated with the development of persistent postmolar gestational trophoblastic tumors. Conclusions LR1 may be important in the pathogenesis of gestational trophoblastic diseases. The increased expression of LR1 in decidual cells of partial and complete moles may not influence the development of persistent gestational trophoblastic tumor. Since they are seen rarely, multicentric studies should be planned to study LR1 expression in invasive moles and gestational trophoblastic neoplasms.

Expression of maspin in gestational trophoblastic disease

Background.Maspin is a tumor suppressor gene whose expression is altered in neoplasia and malignancies of many tissues. In the human placenta, the maspin gene is expressed in trophoblastic cells and might act as an inhibitory regulator of trophoblastic invasion. Hence, in gestational trophoblastic disease (GTD), where there is increased propensity for invasion in the trophoblastic tissue, we hypothesized that maspin expression would be decreased. The present study aimed at investigating the expression of maspin in GTD and its prognostic significance. Methods.Using immunohistochemical staining, we firstly studied the expression of maspin in hydatidiform moles, with gestational age-matched normal first trimester placenta used as control. A total of 38 cases of hydatidiform moles were studied, including 20 complete moles (CM) and 18 partial moles (PM). Among them, 10 cases of the CM group and 8 cases of the PM group subsequently developed gestational trophoblastic neoplasia (GTN). Immunostaining was also performed on tissue from 4 cases of choriocarcinoma and 5 cases of placental site trophoblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR) was further performed on RNA extracted from 10 hydatidiform moles (5 with GTN and 5 without) and 6 normal first-trimester placentae. Results.In all tissue sections, nuclear expression of immunostaining signal was demonstrated, mainly in the cytotrophoblasts. The percentage of trophoblastic nuclei stained in both complete and partial moles was significantly lower than that in normal first-trimester placenta (P < 0.001). However, there was no significant difference in immunostaining between complete and partial moles (P > 0.05). There was also significantly lower expression of maspin in those cases subsequently developing GTN than those which did not (P = 0.01). Immunostaining on choriocarcinoma and placental site trophoblastic tumor showed reduced expression of maspin in all the tumor cells. Reverse transcriptase-polymerase chain reaction revealed that the expression of maspin was consistently down-regulated in all the hydatidiform mole samples. Conclusions.Our results suggest that there is down-regulated expression of maspin in gestational trophoblastic diseases, and the down-regulation is more prominent in cases developing gestational trophoblastic neoplasia. This may play a role with prognostic significance in the pathogenesis and malignant transformation of hydatidiform moles.

Id helix‐loop‐helix proteins are differentially expressed in gestational trophoblastic disease

To assess the expression of Id proteins in trophoblastic tissues and to correlate this with clinical parameters, proliferative and apoptotic indices as well as to related oncogene expression. Immunohistochemistry for Id1, Id2, Id3 and Id4 was performed on 83 trophoblastic tissues including 17 normal first-trimester placentas, seven term placentas, 47 hydatidiform moles (HM), and 12 spontaneous miscarriages. The four Id proteins were predominantly expressed in the villous and implantation site intermediate trophoblast. Expression of Id1 in HM was significantly higher than that in normal placenta (P = 0.0006) and spontaneous miscarriage (P = 0.0001) but did not correlate with subsequent development of gestational trophoblastic neoplasia (GTN). Id1 expression correlated with the proliferation index as assessed by MCM7 (P = 0.003) and Ki67 (P = 0.017) and with the apoptotic activity assessed by TUNEL (P = 0.001) and M30 CytoDeath antibody (P = 0.013). Moreover, the expression of Id1 correlated with the expression of p53 (P = 0.004), p21(WAF1) (/CIP1) (P = 0.003) but not with p16 (P = 0.107). Id proteins may play a role in the regulation of proliferative and apoptotic activity in trophoblastic tissue and are potentially useful in differentiating molar and non-molar gestation, but are not helpful in predicting GTN.

Differential Gene Expression Identified in Complete Hydatidiform Mole by Combining Suppression Subtractive Hybridization and cDNA Microarray

Complete hydatidiform mole (CHM) is a type of gestational trophoblastic disease with pure paternal chromosome contribution and unpredictable malignant potential. As an attempt to assess the molecular pathogenesis of CHM, suppression subtractive hybridization (SSH) combined with cDNA microarray was used to compare the gene expression pattern of CHM compared with normal first-trimester placenta of similar gestational ages. cDNA microarray analysis using tissue-specific chips constructed with subtracted cDNA libraries identified 13 differentially expressed gene transcripts. Quantitative real-time polymerase chain reaction (PCR) confirmed up-regulation of human chorionic gonadotropin beta subunit (CGB) (P=0.0008) and KIAA1200 (P=0.0005), a G-protein regulator, as well as down-regulation of osteopontin (SPP1) (P<0.0001) in 14 genotyped CHM when compared with 15 normal placentas. These candidate genes may contribute toward understanding the mechanism involved with the development and progression of CHM.

Expression of leptin and leptin receptors in gestational trophoblastic diseases

Objectives. To investigate the expression profile of leptin and leptin receptors in gestational trophoblastic diseases (GTDs). Methods. Using immunohistochemical staining on archival paraffin-embedded tissue sections, we studied the expression of leptin and leptin receptor in hydatidiform moles, with gestational age-matched normal first-trimester placenta used as control. A total of 38 cases of hydatidiform moles were studied, including 20 complete moles (CHMs) and 18 partial moles (PHMs). Among them, 10 cases of the CHM group and 8 cases of the PHM group subsequently developed residual trophoblastic disease (RTD). In addition, two cases of choriocarcinoma and three cases of placental site trophoblastic tumor (PSTT) were also studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) was further performed using RNA extracted from frozen tissue (five CHMs, four PHMs and nine normal first-trimester placenta) to study the expression of leptin and individual leptin receptor isoforms at the transcription level. Results. In all tissue sections, immunostaining signal was shown in the cytoplasmic compartment of cytotrophoblasts and syncytiotrophoblasts, with much stronger staining in the former. Significantly higher immunostaining intensity was shown for both leptin ( P < 0.05) and leptin receptor ( P < 0.001) in both CHMs and PHMs compared to normal first-trimester placenta. There was no significant difference between those cases subsequently developing RTD and those which did not ( P > 0.05). In the choriocarcinoma and PSTT cases, intense immunostaining was found in the tumor cells. RT-PCR revealed that the expression of leptin and all leptin receptor isoforms were significantly higher in both CHMs and PHMs than in normal placenta ( P < 0.05). Conclusions. There is up-regulated expression of leptin and leptin receptor in GTDs. However, there is no obvious correlation with the development of RTD. The exact role played by leptin and its receptors in the pathogenesis of GTDs awaits further investigations.

Matrix Metalloproteinases and Their Inhibitors in Gestational Trophoblastic Diseases and Normal Placenta

Objective. Our purpose was to investigate the expression of matrix metalloproteinases (MMPs) in gestational trophoblastic diseases and normal first-trimester placenta.Methods. Paraffin sections of 16 partial moles, 25 complete moles, 10 gestational choriocarcinomas, and 11 normal first-trimester placentas were studied immunohistochemically for expression of MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, and tissue inhibitor of metalloproteinase-1 (TIMP-1).Results. Nine (90.0%) of the choriocarcinoma cases showed strong intensity of staining for MMP-1. Choriocarcinoma exhibited significantly stronger staining for MMP-1 than syncytiotrophoblast in normal placenta (P < 0.01), partial mole (P < 0.01), and complete mole (P < 0.01). Choriocarcinoma also showed significantly stronger staining for MMP-1 than the extravillous trophoblast in placenta (P < 0.05). MMP-2 was expressed only in syncytio- and extravillous trophoblasts in normal placenta, partial mole, and complete mole. Choriocarcinoma and the extravillous trophoblast in partial mole and complete mole had significantly stronger staining for MMP-2 than the extravillous trophoblast in placenta (P < 0.05, P < 0.01, P < 0.01, respectively). Choriocarcinoma also exhibited significantly stronger staining for MMP-2 than syncytiotrophoblasts in placenta (P < 0.01), partial mole (P = 0.05), and complete mole (P < 0.01). The expression of MMP-3, MMP-9, and MMP-13 was similar in all four tissues with the predominance of syncytiotrophoblast for MMP-3 and MMP-13 and cytotrophoblast for MMP-9. While 8 (73.0%) placentas, 14 (87.5%) partial moles, and 19 (76.0%) complete moles showed strong immunoreactivity for TIMP-1 in syncytiotrophoblasts, no strong staining was found in choriocarcinomas (P < 0.01, P < 0.01, P < 0.01, respectively).Conclusion. The extravillous trophoblast of first-trimester placenta has significantly less expression of MMP-1 than choriocarcinoma and significantly less expression of MMP-2 than choriocarcinoma and extravillous trophoblast of partial and complete mole. The expression of TIMP-1 was significantly less in choriocarcinoma than the syncytiotrophoblast of normal placenta, partial mole, and complete mole. MMPs and their inhibitors may play a role in the pathogenesis of gestational trophoblastic diseases.

Partial hydatidiform moles have impaired differentiated function (human chorionic gonadotropin and human placental lactogen secretion) in response to epidermal growth factor and 8-bromo-cyclic adenosine monophosphate

The null hypothesis is that partial hydatidiform moles have normal differentiated function (human chorionic gonadotropin and human placental lactogen secretion) in response to epidermal growth factor and 8-bromo-cyclic adenosine monophosphate. Two complete moles, 10 partial hydatidiform moles, and 19 normal first-trimester placentas in monolayer culture were exposed to 10 ng/ml epidermal growth factor, 1 mmol/L 8-bromo-cyclic adenosine monophosphate plus 1 mmol/L theophylline, or control. Human chorionic gonadotropin and human placental lactogen secretion was measured. Frequency of response to stimuli was compared by chi 2 analysis, and hormone secretion was compared by analysis of variance. Partial moles demonstrated reduced frequencies of response of human chorionic gonadotropin and human placental lactogen to epidermal growth factor (partial moles 2/8 and 2/8, respectively; normal placentas 16/19 and 7/18, respectively; p less than 0.025) and of human chorionic gonadotropin to 8-bromo-cyclic adenosine monophosphate (partial moles 3/5, normal placentas 13/16; p less than 0.005). Partial hydatidiform moles demonstrate impaired human chorionic gonadotropin and human placental lactogen secretory responsiveness to epidermal growth factor and cyclic nucleotides in comparison with normal first-trimester trophoblast.

Characteristics of alkaline phosphatase from two continuous lines of human choriocarcinoma cells

Several characteristics of human choriocarcinoma alkaline phosphatase have been studied. BeWo and Jar choriocarcinoma lines each contain heat-stable alkaline phosphatase activity with characteristics similar to the D-variant term placental isoenzyme. The activity is also similar to the Nagao enzyme found in many malignancies. Each choriocarcinoma also has heat-labile alkaline phosphatase activity with characteristics similar to the enzyme found in normal first-trimester placenta. Neither BeWo alkaline phosphatase could be stimulated with cortisol. Both BeWo alkaline phosphatase activities could be stimulated with methotrexate and actinomycin D.