Trimester Chorionic Villi Research Articles

β-Thalassemia in Pakistan

Prenatal diagnosis (PND) of β-thalassemia has been underutilized in Pakistan because of a number of social and economic factors. National Institute for Biotechnology and Genetic Engineering Faisalabad in collaboration with Multan Institute of Nuclear Medicine and Radiotherapy Multan introduced free PND service for carrier couples of Multan district. Multan has a population of about 4 million. More than 170 couples registered for retrospective PND and in 2 years 105 PND were carried out through first trimester chorionic villus sampling. Almost 90% of these couples were unable to afford the cost of PND and would not have undergone the test as free service was not available. Monoplex and Multiplex Amplification Refractory Mutation System-polymerase chain reaction and genomic DNA sequencing were used for detection of IVS (intervening sequence)-I-5 (G-C), FSC (frameshift codon)-8/9 (+G), FSC-41/42 (-TTCT), IVS-I-1 (G-T), 619 bp deletion, and CD-15 (G-A) β-globin mutations. Eighty-one percent (85/105) couples analyzed were in a consanguineous marriage. Twenty-three fetuses were found homozygous mutant and all couples opted for discontinuation of affected pregnancies. More families are registering for PND after establishment of this free and accessible PND service.

T11.2 Evaluation of the oxidative state of maternal serum low density lipoproteins in intrauterine growth restriction and preeclampsia

Preeclampsia (preE), is characterized by abnormal placental invasion and function. Marinobufagenin (MBG), a cardiotonic steroid (CTS), inhibits cytotrophoblast (CTB) cell functions that are critical for normal placental development. This study tests the hypothesis that CTSs induce anti-angiogenic and anti-proliferative effects in CTB cells.Human extravillous CTB cells of the line Sw-71, derived from first trimester chorionic villus tissue, were incubated with 0, 0.1, 1, 10, and 100 nM of each of three CTSs (MBG, cinobufatalin (CINO) and ouabain (OUB)) for 48 h. Thereafter, levels of pro-angiogenic (vascular endothelial growth factor (VEGF165), placental growth factor (PlGF)) and anti-angiogenic (soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng)) factors were measured in culture media using ELISA kits. Expression of three receptors (VEGF receptor 1 (VEGFR1), angiogenic angiotensin type 1 receptor (AT1) and anti-angiogenic angiotensin type 2 receptor (AT2)) were assayed using immunoblotting (western blots) in cell lysates.sFlt-1 and sEng secretion were increased while VEGF165 and PIGF were decreased in the culture media of CTB cells treated with 1 nM or more of each CTSs (p < 0.01 for each). The AT2 receptor expression was up-regulated (p < 0.05) in CTB cells treated with 1 nM or more of MBG and CINO and with 100 nM OUB, while AT1 and VEGFR1 expressions decreased (p < 0.05) with 1 nM or more of MBG and 10 nM or more of CINO and OUB.CTSs influence extravillous CTB cells to induce an anti-angiogenic and anti-proliferative profile.

Histomorphometric characteristics of first trimester chorionic villi in pregnancies with low serum pregnancy-associated plasma protein-A levels: relationship with placental three-dimensional power doppler ultrasonographic vascularization

Objective. To evaluate histomorphometric vascular characteristics from samples obtained by chorionic villus sampling (CVS) in pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) levels and to relate these findings to three-dimensional (3D) placental volume and power Doppler vascularization.Methods. Immediately before CVS, placental 3D-power Doppler ultrasonography was performed at 11 + 0 to 13 + 6 weeks in 12 pregnancies with PAPP-A concentrations <0.3 multiples of median (MoM) as well as in 11 control women. Using a standardized setting placental volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were measured. Histomorphometric parameters of villi were blindly evaluated with a video-computerized-image-analysis system.Results. Pregnancies with low PAPP-A showed a significantly reduced number of capillary vessels per villus cross-section (p = 0.005) and a smaller capillary diameter (p = 0.041). Placental vascular indices were significantly related to the number of fetal capillary vessels per villus (VI: r = 0.51, p = 0.03; FI: r = 0.48, p = 0.04; VFI: r = 0.56, p = 0.01).Conclusions. Differences in placental vascularization are present in first trimester in pregnancies with low PAPP-A and they are associated to altered 3D placental Doppler indices.

Identification of Multipotent Cytotrophoblast Cells from Human First Trimester Chorionic Villi

In this article we used immunohistochemistry and FACS analyses to show that cells expressing markers typical of human stem cells such as SSEA4, OCT-4, ALP, and CD117 are present within the cytotrophoblastic tissue of human fetal chorionic villus samples (CVSs). After immunoselection of CV cells for SSEA4, FACS analyses showed an increased number of cells positive for OCT-4 and ALP and a small percentage (around 4%) of side population (SP) cells. In the same cell population, RT-PCR indicated the presence of OCT-4, NANOG, and SOX2 transcripts, also typical of stem cells. Depending on the in vitro conditions, a subset of SSEA4+ cells formed colonies resembling hESCs, with limited self renewal ability. At the same time, these cells were able to differentiate in vitro into derivatives of all three germ layers. When inoculated into immunocompromised mice, SSEA4+ cells did not form teratomas but were able to populate depleted hematopoietic tissues. Moreover, after injection into mouse blastocysts, they were incorporated into the inner cell mass and could be traced into several tissues of the adult chimeric mice. Finally, we show that SSEA4+ cells isolated from fetuses affected by Spinal Muscular Atrophy (SMA) can be genetically corrected with high efficiency in culture by Small Fragment Homologous Recombination (SFHR), a gene targeting approach. Taken together, our results indicate that SSEA4+ cells obtained from human CVSs contain a subpopulation of multipotent cells that we propose to name Human Cytotrophoblastic-derived Multipotent Cells (hCTMCs). These cells may be a safe and convenient source of cells for cell-based therapy, as well as an ideal target for in utero fetal gene therapy.

Placenta mesenchymal stem cells on a chorion scaffold as a potential osteogenic graft for peripartal bone regeneration

1 Objective To manufacture a three dimensional, biodegradable and stem cell-loaded composite graft from placental components for site-specific perinatal repair of bone defects in newborns suffering from genetic skeletal dysplasias. 2 Study Design We manufactured a scaffold from human chorion membrane by removing cellular components from the chorionic reticular layer enzymatically and mechanically. That acellular scaffold served as a support material for placental mesenchymal stem cell (MSC) outgrowth in that we cultured human MSCs derived from either first trimester chorionic villi or term chorion membrane on it. We recently showed that these cell types possess a sound osteogenic differentiation potential. Differentiation to the osteogenic lineage was induced. Construct assembly and bone formation were investigated by light-, scanning- and transmission electron microscopy, antibody staining and bone specific assays. 3 Results We managed to free the extracellular matrix of chorionic reticular layer from cells and obtained a bare three dimensional fibrous network. Inoculated MSCs did not only anchor on that scaffold but also invaded it to build a three dimensional structure. Under specific culture conditions these cell-scaffold-constructs differentiated osteogenically. 4 Conclusion The composite graft we obtained might allow a direct supply of autologous or allogeneic mesenchymal stem cells to injured sites and might be a prospective novel treatment option of bony lesions of fetuses and newborns affected with genetic skeletal dysplasias.

The Oncofetal Protein IMP3

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is an oncofetal protein highly expressed in fetal tissue and malignant tumors but rarely found in adult benign tissues. The aim of this study is to determine the expression of IMP3 in benign endometrium, endometrial cancer, and its precursor lesions, trying to see whether IMP3 has any diagnostic usage. Two hundred ninety-eight endometrial samples were examined for IMP3 expression by immunohistochemistry. These included benign endometrium (n=68), atypical hyperplasia or endometrial intraepithelial neoplasia (n=35), endometrial glandular dysplasia (n=21), endometrial intraepithelial carcinoma (n=18), endometrioid carcinoma (n=70), mucinous carcinoma (n=8), serous carcinoma (n=51), clear cell carcinoma (n=12), and other malignancies (n=15). Maturational patterns in the 68 benign endometrial samples included atrophic (n=12), proliferative (n=18), secretory (n=14), menstrual (n=8), and gestational (n=16). Most of the carcinomas were histologically pure; where mixed, the second component constituted <10% of the total tumor volume. The extent and intensity of IMP3 expression was semiquantitatively determined and scored for all samples. A renal cell carcinoma with known IMP3 expression was used as positive control for each immunohistochemistry run. Among the malignant cases, IMP3 expression was predominantly found in endometrial serous carcinoma and its putative precursor lesions, with 3 (14%) of 21 endometrial glandular dysplasia, 16 (89%) of 18 serous endometrial intraepithelial carcinoma, and 48 (94%) of 51 serous carcinomas (P<0.001). In contrast, the frequency of IMP3 expression was significantly lesser in nonserous malignancies with 0 (0%) of 35, 5 (7%) of 70, 0 (0%) of 8, 3 (25%) of 12, and 5 (33%) of 15 positive expression rates in atypical hyperplasia or endometrial intraepithelial neoplasia, endometrioid, mucinous, clear cell carcinomas, and other malignancies, respectively. The IMP3 staining was universally cytoplasmic, with diffuse staining of strong intensity in serous carcinomas, whereas staining was typically patchy and of moderate or weak intensity in nonserous malignancies. Among the benign endometrial samples, decidualized endometrial stroma showed 100% positivity for IMP3. The remaining samples were negative, with the exception of a few weakly proliferative glands in 3 (5%) of 68 cases that showed focal weak immunoreactivity of IMP3. The trophoblasts in the first trimester chorionic villi were also diffusely positive, which was consistent with previously reported findings. We conclude that expression of IMP3, a newly identified cytoplasmic marker, is closely associated with type II endometrial cancer. It seems that IMP3 expression is associated with an aggressive histologic phenotype among endometrial neoplastic lesions. Strong and diffuse IMP3 expression is highly sensitive for endometrial serous and clear cell carcinomas including their putative precursor lesions. Therefore, IMP3 may be a useful diagnostic marker in the assessment of endometrial cancers and their precursor lesions, particularly when the amount of available tissue material is limited and a concern of type II cancer arises. High frequency of IMP3 expression is present in decidualized endometrial stroma of gestational endometrium and chorionic villi in early pregnancy. Although the significance of the latter finding remains unclear, the differential diagnosis between decidual changes and endometrial serous carcinoma is rarely problematic.

The architecture of first trimester chorionic villous vascularization: a confocal laser scanning microscopical study

The aim of this study was to investigate normal chorionic villous vascularization using CD31 immunofluorescence and confocal laser scanning microscopy (CLSM) to elucidate the spatial arrangement in terms of connections between vessels and cords and their branching patterns compared to deficient chorionic villous vascularization in complicated pregnancies. A descriptive morphologic study using CLSM after CD31 immunofluorescence staining of placental biopsies from normal pregnancies (n = 20), complete hydatidiform molar pregnancies (CHMs; n = 3) and empty sacs (n = 3), with a well documented gestational age (GA). In this three-dimensional study, first trimester chorionic villi were occupied by a complex network of mainly cords with redundant connections as early as 5(+5) weeks GA. With increasing GA cords transform into vessels. From about 9 weeks GA onwards, vascular development is characterized by the presence of two large vessels located centrally and surrounded by and connected to a capillary network. In first trimester CHM and empty sacs, we observed a primitive network of mainly cords. This first visualization of the spatio-temporal patterns of blood vessel formation in placental villi is characterized by the development of the vasculosyncytial membrane from a complex network of cords and can be regarded as the placental development before it becomes functional at the end of organogenesis.

Expression of the Fusogenic HERV-FRD Env Glycoprotein (Syncytin 2) in Human Placenta is Restricted to Villous Cytotrophoblastic Cells

Recently, the expression of a human endogenous retrovirus HERV-FRD, able to encode a fusogenic envelope protein (syncytin 2), has been observed in human placenta. The aim of the present study was to localize the expression of syncytin 2 in first trimester placenta. In addition, we investigated the presence of HERV-FRD transcripts during the in vitro differentiation of isolated villous and extravillous trophoblastic cells from first trimester chorionic villi. Using a monoclonal antibody specifically raised against the HERV-FRD Env protein, syncytin 2 was immunolocalized only in the villous trophoblast of the chorionic villi, at the level of cytotrophoblastic cells. Interestingly, immunostaining was not observed in all cells but only in some of them, and was detected, more frequently, at the membrane level at the interface between the cytotrophoblastic cells and syncytiotrophoblast. Labeling was observed neither in the syncytiotrophoblast nor in the mesenchymal core of the villi nor in the extravillous trophoblast. In vitro detection of HERV-FRD transcripts was restricted to villous trophoblastic cells and decreased significantly with time in culture. These results suggest that syncytin 2 might play a role in human trophoblastic cell fusion.

Placental mesenchymal stem cells as potential autologous graft for pre- and perinatal neuroregeneration

Mesenchymal stem cells (MSCs) have a broad differentiation potential. We aimed to determine if MSCs are present in fetal membranes and placental tissue and to assess their potential to differentiate into neurogenic and mesodermal lineages. MSCs isolated from first and third trimester chorion and amnion and first trimester chorionic villi and characterized morphologically and by flourescence-activated cell sorting analysis. Their ability to mature under different culture conditions into various cells of mesodermal and neuroectodermal cell lines was assessed by immuno- and cytochemical staining. Independent of gestational age, cells isolated from fetal membranes and placenta showed typical MSC phenotype (positive for CD166, CD105, CD90, CD73, CD49e, CD44, CD29, CD13, MHC I; negative for CD14, CD34, CD45, MHC II) and were able to differentiate into mesodermal cells expressing cell markers/cytologic staining consistent with mature chondroblasts, osteoblasts, adipocytes, or myocytes and into neuronal cells presenting markers of various stages of maturation. The differentiation pattern was mainly dependent on cell type. Mesenchymal cells from chorion, amnion, and villous stroma can be differentiated into neurogenic, chondrogenic, osteogenic, adipogenic, and myogenic lineage. Placental tissue obtained during prenatal chorionic villous sampling or at delivery might be an ideal source for autologous stem cell graft for peripartum neuroregeneration and other clinical issues.

Modulation of PAPP-A Expression By PPARγ in Human First Trimester Trophoblast

Pregnancy-associated plasma protein-A (PAPP-A) is a metzincin metalloproteinase that cleaves the insulin-like growth factor (IGF)-dependent binding protein-4 and increases in maternal serum during pregnancy. In human placenta PAPP-A is expressed both in villous cytotrophoblasts (VCT) that cover the chorionic villi and in extravillous cytotrophoblasts (EVCT) of the anchoring villi. Due to the key role of PPARgamma in human trophoblast differentiation such as syncytiotrophoblast formation and EVCT invasion, we studied the effect of PPARgamma activation on PAPP-A expression using our in vitro model of EVCT and VCT primary cultures isolated from the same first trimester chorionic villi. First, we demonstrated that invasive EVCT expressed and secreted 10 times more PAPP-A than VCT did. Then, we showed that activation of PPARgamma inhibited PAPP-A gene expression and secretion in EVCT, whereas it had no effect in VCT. Since we have previously shown that PPARgamma agonist inhibits EVCT invasion in vitro, we suggest that PPARgamma-mediated inhibition of PAPP-A might decrease the amount of bioactive IGFII, a factor known to promote trophoblast invasion.

Bi-potential Behaviour of Cytotrophoblasts in First Trimester Chorionic Villi

Murine trophoblast stem (TS) cells express fibroblast growth factor receptor 2 (FGFR2) and are maintained in their proliferative state by fibroblast growth factor 4 (FGF4). We show in this report that in the first trimester human placenta FGFR2 expression is similarly found in a subset of villous cytotrophoblast and in proximal anchoring columns. Western analysis demonstrated declining FGFR2 protein expression as gestation advanced, suggesting a similar role for FGF in early human trophoblast proliferation. Mouse TS cell differentiation is known to occur along two distinct transcriptionally-regulated pathways; extravillous trophoblast (EVT) cells invade the uterine wall to promote maternal blood flow whilst syncytiotrophoblast lines chorionic villi in the labyrinth. Similar differentiation steps occur in the human placenta though the fate of human trophoblast stem cells is presently unknown. To investigate the mechanisms underlying human cytotrophoblast differentiation we have developed a novel cultured floating first trimester villous explant model in which denuded first trimester villi spontaneously regenerate syncytiotrophoblast following 48 h of culture. Addition of FGF4 and heparin inhibited syncytiotrophoblast regeneration in favor of forming clumps of cytotrophoblast. Proximal cells in these clumps were FGFR2 immuno-reactive and proliferative, intermediate parts expressed alpha5beta1-integrin, while the distal portion expressed HLA-G and the invasive integrin alpha1beta1 indicating differentiation to the EVT phenotype. In contrast, non-denuded villi exposed to FGF4 exhibited similar proliferation of the cytotrophoblast; however, these cells did not express any of the invasive EVT markers. We conclude that FGFR2-positive chorionic cytotrophoblasts exhibit bi-potential behaviour, being capable of forming either syncytiotrophoblast or EVT. We suggest bipotential trophoblast progenitor cells persist during first trimester human placental development.

First trimester maternal serum α-fetoprotein screening for Down syndrome and other aneuploidies

Low maternal serum AFP (MSAFP) values in the first trimester of pregnancy have been associated with an increased risk for chromosome disorders. In our own first trimester chorionic villus sampling (CVS) series, MSAFP determinations were carried out in 1,448 singleton pregnancies. Aneuploidies were detected in 26 of these. The pre-CVS MSAFP values in these pregnancies were compared to those in pregnancies with normal outcome. Statistical analysis did not show a diagnostically useful correlation between low first trimester MSAFP values and aneuploidy in our cohort.

Abnormal development of the vasculosyncytial membrane in early pregnancy failure

To investigate chorionic villous vasculogenesis (maturation) and development of the vasculosyncytial membrane (margination) using CD34 immunohistochemistry. Case-control study. Microscopic analysis of first trimester chorionic villi. Twelve patients with anembryonic pregnancies, 12 with embryonic death, and 12 with terminated normal pregnancies. Quantitative analysis of chorionic villi blinded to group and gestational age using CD34 immunohistochemistry. Vascular parameters (mean functional vascular area, vessels with a lumen, and hemangiogenetic cords, peripherally or centrally located). Terminated normal pregnancies show significantly more vessels per chorionic villus (maturation) (mean +/- SEM) in comparison with embryonic deaths and anembryonic pregnancies (5.3 +/- 0.3 vs. 1.4 +/- 0.2 and 0.7 +/- 0.1), located mainly peripherally (margination) (3.0 +/- 0.2 vs. 0.9 +/- 0.2 and 0.2 +/- 0.0). Anembryonic pregnancies show significantly more centrally located cords in comparison with embryonic deaths and termination of pregnancies (3.3 +/- 0.2 vs. 2.7 +/- 0.2 and 1.5 +/- 0.1). A defective chorionic villous vascularization, demonstrating inadequate vasculogenesis and abnormal development of the vasculosyncytial membrane, is seen in pregnancies complicated by embryonic death and is even more pronounced in anembryonic pregnancies. Initiation of placental vasculogenesis is a basic feature in all types of pregnancy and is subsequently modulated directly or indirectly by embryonic signaling.

Cellular localization of gonadotropin-releasing hormone (GnRH) I and GnRH II in first-trimester human placenta and decidua.

There is increasing evidence to suggest that the classical form of GnRH (GnRH I) and the second mammalian form of this hormone, GnRH II, play regulatory roles in human implantation and placentation. To date, the cellular distribution of these two hormones at the maternal-fetal interface remains poorly characterized. In these studies, we localized GnRH I and GnRH II expression in human placenta and decidua to distinct subpopulations of cells isolated from these tissues and in a chorionic villous/decidual tissue coculture system that mimics many of the cellular events of early placentation. GnRH I and GnRH II mRNA transcripts were detected in first-trimester placenta, whereas only GnRH I was detected in tissues obtained at term. Both hormones were further immunolocalized to the mononucleate villous and distinct subpopulations of extravillous cytotrophoblasts of the placenta in vivo and in vitro. In contrast, GnRH I but not GnRH II was expressed in the outer multinucleated syncytial trophoblast layer of first trimester chorionic villi and in cultures of villous cytotrophoblasts allowed to undergo differentiation and fusion in vitro. GnRH I and GnRH II were also found to be coexpressed in first-trimester decidua and primary cultures of decidual stromal cells. Collectively, these observations demonstrate that GnRH I and GnRH II have both common and discrete cellular distributions in the placenta and decidua and suggest that these two hormones are capable of eliciting their biological actions in an autocrine and/or paracrine manner within and between these maternal and fetal cellular compartments.

Dysthymic Reactions of Women Undergoing Chorionic Villus Sampling for Prenatal Diagnosis of Hemoglobinopathies or Karyotyping

Objectives: The aim of the study was to investigate the levels of anxiety and depression, as well as liability to depression, of women undergoing chorionic villus sampling (CVS) due to the risk of giving birth to a child suffering from hemoglobinopathy, or trisomy. Methods: The study population consisted of 309 women who attended the Fetal Medicine Unit of Alexandra Hospital, University of Athens, Athens, Greece for a first trimester chorionic villus sampling (CVS). One hundred and fifty-nine women (group A) underwent CVS due to increased possibility of carrying an embryo with β-thalassemia, while 150 women had the procedure because of an increased nuchal translucency measurement, or a positive first trimester biochemical screening (group B). Three hundred and nine women, matched by age and gestational age with those of the study group, who were not subjected to any diagnostic intervention formed the control group. We further investigated differences of dysthymic reactions among three subgroups of women at risk for hemoglobinopathy: (a) women undergoing their first pregnancy; (b) women who had been pregnant more than once but had not any children, and (c) women who had given birth to at least one healthy child, irrespective of previous terminations. Results: The incidence of clinically elevated levels of anxiety and depression was significantly higher in groups A and B compared to controls (p < 0.001), while no significant difference was found in mean anxiety and depression, as well as the liability to depression among the three groups. Clinically elevated levels of depression were found in 10.1 and 4.7% of the women of the hemoglobinopathy and karyotyping group, respectively. Especially women who had no children, due to previous pregnancy terminations presented significantly higher incidence of elevated depression compared to women who were pregnant for the first time, or women who had given birth to at least one healthy child in their life. Conclusions: The findings of this study highlight the necessity of training medical and nursing personnel to understand and respond to the psychological and social needs of women undergoing CVS due to increased risk for hemoglobinopathy, and especially to those who have no children and who have a history of pregnancy termination due to an affected fetus.

Regulatory effects of gonadotropin-releasing hormone (GnRH) I and GnRH II on the levels of matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinases-1 in primary cultures of human extravillous cytotrophoblasts.

An intricate balance between the production of matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs), modulates the overall proteolytic activity of trophoblasts during human implantation. In these studies we have examined the ability of classical GnRH I and the second form of this hormone (GnRH II) to regulate MMP-2, MMP-9, and TIMP-1 mRNA and protein levels in extravillous cytotrophoblasts propagated from explants of first trimester chorionic villi. GnRH I and GnRH II were found to increase MMP-2 and MMP-9 mRNA and protein levels in these primary cell cultures in a dose- and time-dependent manner using quantitative competitive-PCR and ELISA. In contrast, these two hormones decreased trophoblastic TIMP-1 mRNA and protein levels. Cetrorelix, a GnRH receptor antagonist, inhibited the regulatory effects of GnRH I, but not GnRH II, on MMP-2, MMP-9, and TIMP-1 expression in these cells. Collectively, these observations suggest that GnRH I and GnRH II differentially regulate MMP-2, MMP-9, and TIMP-1 expression in human trophoblasts, possibly via distinct receptor-mediated intracellular signaling pathways.

Effect of matrigel on human extravillous trophoblasts differentiation: modulation of protease pattern gene expression.

The human placenta is characterized by extensive trophoblast invasion of the uterus. Indeed, extravillous cytotrophoblast cells invade the decidua and the upper third of uterine spiral arteries in the myometrium. This invasion is reflected in situ by the expression of specific markers. In order to study this invasion process, we have established an in vitro culture model of human extravillous trophoblast isolated from first trimester chorionic villi. The aim of this study was to investigate the effect of a composite matrix, the Matrigel required for the culture of this homogenous population of extravillous trophoblasts (EVCT), on their in vitro differentiation. The effect of Matrigel was studied on different markers characterized by immunocytochemistry and by real-time polymerase chain reaction assay of transcripts. In addition, the expression of 12 different matrix metalloproteases and their inhibitors were investigated. We show that human extravillous cytotrophoblasts acquire an invasive phenotype on Matrigel associated with a specific pattern of protease gene expression. This in vitro model will be of interest to study the cellular mechanisms involved in abnormal trophoblast invasion observed in poor placentation and preeclampsia.

Trisomy 13 or 18 (mosaicism) in first trimester cytotrophoblast cells: false-positive results in 11 out of 51 cases

Objective: The finding of full or mosaic trisomy 13 or 18 in first trimester chorionic villus sampling (CVS) may be a false-positive result. This report provides incidence and outcome information that may be helpful in counselling individual patients and in choosing adequate follow-up. Study design: From a series of 6820 CVS cases, we retrospectively collected data on all patients ( n=51) with full ( n=30) or mosaic ( n=5) trisomy 18, and full ( n=13) or mosaic ( n=3) trisomy 13 in cytotrophoblast cells. Results: Five false-positives were seen in patients with full trisomy 18 and three in the mosaic cases. One false-positive result was observed in full trisomy 13 and two false-positives in cases of mosaicism. No false-negative results were reported. Conclusion: The diagnosis of trisomy 13 or 18 in cytotrophoblasts should be confirmed in other tissues, unless fetal abnormalities are seen at ultrasound. In case of mosaicism, follow-up amniocentesis is advised.

FISH analysis of fetal nucleated red blood cells from CVS washings in cases of aneuploidy.

In chorionic villus sampling (CVS) the chromosome analysis is inconclusive in 1-2% of the samples. In many cases follow-up amniocentesis is performed. Fetal nucleated red blood cells (FNRBCs) are present in washings of chorionic villus samples. We wanted to establish whether analysis of these true fetal cells, using fluorescence in situ hybridization (FISH), could support the CVS karyotype. We analysed washings of first trimester chorionic villi from non-mosaic 45,X (n=6) and full trisomy 18 cases (n=7). FNRBCs were identified by immunostaining and FISH was performed with chromosome-specific probes for X, Y and 18. In all 13 samples FNRBCs were present (between 4 and 30 cells per sample). Five cases of monosomy X showed one X signal in 89-100% of the nuclei; in the other case 50% of the nuclei displayed one signal. In the trisomy 18 cases three spots were seen in 60-100% of the cells. The CVS aneuploidy was confirmed in FNRBCs in all samples, so FISH on FNRBCs can be used in cases of non-mosaic numerical chromosomal abnormalities. This test can confirm a CVS diagnosis of monosomy X or trisomy 18 and thus minimize the risk for false-positive diagnoses. An additional invasive test may be prevented.

Flow Cytometric Measurement of Intracellular Th1 and Th2 Cytokine Production by Human Villous and Extravillous Cytotrophoblast

A wide variety of cytokines are present at the maternal–fetal interface, but the extreme cellular complexity of the placenta has made it difficult to determine which cytokines are produced by which cells. Hence novel flow cytometric methods have been applied to determine intracellular cytokine production by specific cell-types in placental cell suspensions. Cell suspensions were prepared from first and third trimester chorionic villi and third trimester amniochorion by enzymatic digestion and Percoll density gradient centrifugation. After overnight incubation in the presence of monensin, cells were fixed, permeabilized and labelled with antibodies for villous cytotrophoblast (cytokeratin+, MHC class I-), extravillous cytotrophoblast (cytokeratin+, MHC class 1+) and leucocytes (CD45+). These cell types were further characterized by their expression of EGFR (proliferative cytotrophoblast) and c-erbB2 (invasive cytotrophoblast). Production of IL-4, IL-10, TNF-α, IFN-γ and IL-12 was determined by simultaneous labelling with the appropriate monoclonal antibodies. Only IL-4 was detected consistently in all samples of cytotrophoblast. IL-10 was not detected but IL-10 mRNA was demonstrated in third trimester chorionic villus digests by RT-PCR. Although IL-4 secretion has not been demonstrated, these data suggest that, in vivo there may be a ‘Th2 type cytokine bias’ orchestrated by the trophoblast. It is proposed that other cytokines (including IL-10 and TNF-α) are produced by decidual leukocytes, and not cytotrophoblast, at the maternal–fetal interface.