Placenta - Articles in Press

Differential susceptibility of isolated human trophoblasts to infection by Trypanosoma cruzi - Corrected Proof

C. Díaz-Luján, M.F. Triquell, A. Schijman, P. Paglini, R.E. Fretes — 2012-02-02

Abstract: The aim of the work was to analyze the susceptibility of the placental syncytiotrophoblast (STB) and cytotrophoblast (CTB) cells to infection by the causal agent of congenital Chagas’ disease, Trypanosoma cruzi, and the possible parasite route for placental invasion. Monolayers of CTB and STB and VERO as control cells were used. The infection of STB was significantly lower that of the CTB and Vero cells (p < 0.05) which coincided with a significantly increased mortality of parasite cells in the culture medium and trypanocidal levels of nitric oxide. We conclude that the syncytiotrophoblast, the first placental barrier, is the main barrier of the chorionic villous that limits the infection by T. cruzi. This work opens the possibility of a new mechanism for placental infection when there are discontinuities in the first placental barrier.

Placenta accreta: Pathogenesis of a 20th century iatrogenic uterine disease - Corrected Proof

E. Jauniaux, D. Jurkovic — 2012-01-30

Abstract: Placenta accreta refers to different grades of abnormal placental attachment to the uterine wall, which are characterised by invasion of trophoblast into the myometrium. Placenta accreta has only been described and studied by pathologists for less than a century. The fact that the first detailed description of a placenta accreta happened within a couple of decades of major changes in the caesarean surgical techniques is highly suggestive of a direct relationship between prior uterine surgery and abnormal placenta adherence. Several concepts have been proposed to explain the abnormal placentation in placenta accreta including a primary defect of the trophoblast function, a secondary basalis defect due to a failure of normal decidualization and more recently an abnormal vascularisation and tissue oxygenation of the scar area. The vast majority of placenta accreta are found in women presenting with a previous history of caesarean section and a placenta praevia. Recent epidemiological studies have also found that the strongest risk factor for placenta praevia is a prior caesarean section suggesting that a failure of decidualization in the area of a previous uterine scar can have an impact on both implantation and placentation. Ultrasound studies of uterine caesarean section scar have shown that large and deep myometrial defects are often associated with absence of re-epithelialisation of the scar area. These findings support the concept of a primary deciduo-myometrium defect in placenta accreta, exposing the myometrium and its vasculature below the junctional zone to the migrating trophoblast. The loss of this normal plane of cleavage and the excessive vascular remodelling of the radial and arcuate arteries can explain the in-vivo findings and the clinical consequence of placenta accreta. Overall these data support the concept that abnormal decidualization and trophoblastic changes of the placental bed in placenta accreta are secondary to the uterine scar and thus entirely iatrogenic.

Rat placentation: An experimental model for investigating the hemochorial maternal-fetal interface - Corrected Proof

M.J. Soares, D. Chakraborty, M.A. Karim Rumi, T. Konno, S.J. Renaud — 2012-01-30

Abstract: The rat possesses hemochorial placentation with deep intrauterine trophoblast cell invasion and trophoblast-directed uterine spiral artery remodeling; features shared with human placentation. Recognition of these similarities spurred the establishment of in vitro and in vivo research methods using the rat as an animal model to address mechanistic questions regarding development of the hemochorial placenta. The purpose of this review is to provide the requisite background to help move the rat to the forefront in placentation research.

Connection between the secretion of few proteins and the growth of the gestational sac and the placenta: Scientific observations - Corrected Proof

M.I. Nor Azlin, S. Das — 2012-01-30

We read with much interest the published article by Sahraravand et al. . We think that it would be interesting to have nuchal translucency done within the period of study. This is because, one has to watch for fetal anomaly and see how this could have its effect on the levels of those placental proteins as well correlating to the findings of the nuchal ultrasound scanning. Regarding the Fig. 1 in the result section, at week 8, hCG had the highest level (i.e. in its function maintaining the supply of progesterone). After 8 weeks, the level declined. Nevertheless, from 8 weeks onwards, a steep curve was observed both in PAPPA and ADAM12 (as they function on IGF for placental growth and also for progesterone supply replacing the percussion effect of declining hCG). On the other hand, the rate of PP13 increment was lesser after week 8, as the hCG declined compared to the other two placental proteins. This was probably when the invasion of maternal spiral artery had been achieved (with the help by prostaglandin released by PP13). At the same time, progesterone from placenta was sufficient enough (as supported by the other two placental proteins) to begin its function and as clearly described as organ of transfer . Although the three placental proteins were equally important for placental growth and supported its function, but PP13 rates peaked, earlier. This probably reflects the prominent function of its maternal vascular remodeling.We applaud the meticulous work by the authors.

An experimental mixed bacterial infection induced differential secretion of proinflammatory cytokines (IL-1β, TNFα) and proMMP-9 in human fetal membranes - Corrected Proof

2012-01-27

Abstract: Overall, 1–4% of all births in the US are complicated by choriamnionitis. Choriamnionitis is a polymicrobial infection most often due to ascending genital microbes which, in over 65% of positive amniotic fluid cultures, involves two or more organisms. In this study, we determine the cytokines expression (IL-1β, TNFα) and prometalloproteinase activation (proMMP-2 and proMMP-9) after double o single infection an in vitro model of human fetal membranes. Fetal membranes at term were mounted in the Transwell culture system and after 24 h of infection, choriodecidual, and amnion media was collected. IL-1β and TNFα were evaluated by ELISA, whereas proMMP-9 and proMMP-2 were determined by substrate gel zymography. The choriodecidual and amnion compartments actively respond to the infectious process, which induced the secretion of IL-1β, TNFα, and proMMP-9 after either mixed or single infection. The proMMP-2 secretion profile was the same after all experimental conditions. There was no synergy between Streptococcus agalactiae and Escherichia coli for inducing the secretion of inflammatory factors or degradative metalloproteinase. In conclusion, these two bacteria could initiate different pathways to induce chorioamnioitis.

Role of Ureaplasma urealyticum in altering the endothelial metal concentration during preeclampsia - Corrected Proof

E. Padmini, V. Uthra — 2012-01-27

Abstract: Objectives: Preeclampsia is a pregnancy specific disorder connected with endothelial cell dysfunction. In vitro stimulation of preeclamptic placental endothelial cell with Ureaplasma urealyticum will help in understanding its relationship with the host cell. Metals and metal-containing compounds are known to play important roles in many biological processes, including metabolic pathway, inflammation and function of proteins.Study design: The variation in expression of various metals was assessed for the first time using FESEM (Field Emission Scanning Electron Microscope) with EDX (Energy Dispersive X-ray spectroscopy) technique in endothelial cells isolated from normotensive and preeclamptic placenta with and without in vitro U. urealyticum stimulation. The results were correlated with the expression of HSP (heat shock protein) 70 in all the 4 endothelial cells.Results: Preeclampsia and U. urealyticum infection alters endothelial cell size, HSP70 expression and metal (sodium, potassium, calcium, iron) concentration. There is a significant increase in the concentration of iron and calcium and decrease in HSP70 expression and endothelial cell size in preeclamptic endothelial cell with U. urealyticum stimulation.Conclusion: This work is the first step in the identification of metals pertinent to mollicute infection and lays the foundation for future studies concentrating on characterization of these metal associated or containing molecules. The ionic imbalance observed infers that calcium and iron supplementation should be executed with caution both during preeclampsia and U. urealyticum infection in pregnancy. This study also suggests that the HSP70 mediated protection exhibited in endothelial cell during preeclampsia is lost upon U. urealyticum infection which further contributes to the observed endothelial cell damage.

Abruptio placentae in the baboon (Papio spp.) - Corrected Proof

2012-01-24

Abstract: Introduction: Placental abruption is a serious condition that increases perinatal morbidity and mortality. Clinical prevention and treatment options are limited, especially in human preterm deliveries. Knowledge of the mechanisms that keep the placenta in place during pregnancy is critical for developing strategies for the prevention of abruption. Failure of physiological transformation of spiral arteries has been described as a major contributing factor of the placental abruption development. Baboons (Papio spp.) share striking similarities with humans in regard to placental structure, utero-placental blood flow, and fetal development; however, the mode of trophoblast invasion is shallow in baboons. This fact prompted the hypothesis that the incidence of placental abruption will be increased in baboons compared to humans.Material and methods: Baboon placentas were collected between 2002 and 2008. Two independent veterinary pathologists evaluated the slides. A certified physician pathologist performed additional histology.Results: Placental abruption was diagnosed in 22 baboons among 2423 live births during the study period (0.9% prevalence). The most common clinical presentations were fetal demise and vaginal bleeding. The most common pathological findings were intraplacental hemorrhages with or without hematoma formation (86.4%). Other findings consisted of neutrophil infiltration (50%), decidual necrosis (22.7%), decidual vascular congestion and inflammation, villous congestion and retroplacental hemorrhage/hematoma (each 18.2%). These pathologic findings were the same for term and preterm deliveries.Conclusion: This is the first systematic study of placental abruption in non-human primates, analyzing a large colony of baboons. Despite differences in trophoblast invasion, the clinical features observed in placental abruption affecting baboons resembled those reported in humans. The cluster of placental pathological findings in baboons also agreed with clinical reports, but the prevalence of these findings differed between baboons and humans. We discuss a mechanism of anti-abruption forces that offset shallow trophoblast invasion observed in baboons.

Uteroplacental arterio-venous difference in soluble VEGFR-1 (sFlt-1), but not in soluble endoglin concentrations in preeclampsia - Corrected Proof

M.C. Paasche Roland, B. Lorentzen, K. Godang, T. Henriksen — 2012-01-24

Abstract: The aim was to determine plasma levels of sFlt-1 and sEng on the arterial and venous side of the uteroplacental circulation in preeclamptic patients and healthy controls.Preeclamptic patients had higher arterial concentrations than controls of sFlt-1 (17,450 vs 5055 pg/ml, p = 0.003) and sEng (68.7 vs 28.7 ng/ml, p = 0.003).In the preclampsia group sFlt-1 was higher in the uterine vein than in the radial artery (22,450 vs 17,450 pg/ml, p = 0.005). We found no gradient for sEng.Our results support the hypothesis that excess sFlt-1 at least partly originates in placenta, while excess sEng appears to have a different origin.

Myeloperoxidase in the plasma and placenta of normal pregnant women and women with pregnancies complicated by preeclampsia and intrauterine growth restriction - Corrected Proof

T.-H. Hung, S.-F. Chen, L.-M. Lo, M.-J. Li, Y.-L. Yeh, T.-T. Hsieh — 2012-01-24

Abstract: Myeloperoxidase (MPO) is a heme protein produced and released by activated neutrophils and monocytes, and increased MPO is considered important in the pathophysiology of cardiovascular diseases (CVD). Accumulating evidence suggests that preeclampsia (PE), idiopathic intrauterine growth restriction (IUGR), and CVD share many similar metabolic disturbances, including an enhanced systemic inflammatory response and endothelial dysfunction. We hypothesized that MPO plays an important role in the development of PE and IUGR. Plasma samples were collected mid-gestation and at delivery from women with normal pregnancies (n = 40) and those who subsequently developed PE (n = 20), IUGR (n = 11) or both (PE + IUGR, n = 8). Placental samples were obtained immediately after delivery from 22 women with normal pregnancies, 19 women with PE, 14 women with IUGR, and 14 women with PE + IUGR. The MPO concentrations were measured using ELISA. Women with PE + IUGR had significantly higher plasma MPO before delivery than normal pregnant women. There was no difference in plasma levels at mid-gestation or the placental concentrations between women with normal pregnancies and those who developed PE, IUGR, or PE + IUGR. Using explants prepared from the placentas of 8 women with normal pregnancies and 8 women with PE, we found no difference in the levels of MPO in the tissue homogenates and culture media between these two groups of women. Together, these results indicate that increased maternal circulating MPO in women with PE + IUGR is likely a result of enhanced systemic inflammation caused by the established disease rather than a primary pathophysiological factor.

Secretion and transfer of the thyroid hormone binding protein transthyretin by human placenta - Corrected Proof

2012-01-24

Abstract: Context: The thyroid hormone and retinol binding protein transthyretin (TTR) is synthesised by human trophoblasts. Polarised JEG-3 choriocarcinoma cells grown in bicameral chambers secrete TTR predominantly apically but also basally and these cells and human trophoblasts also take up TTR suggesting that there may be a placental TTR shuttle that participates in materno-fetal transfer of thyroid hormones and retinol.Objectives and methods: Our objective was to investigate TTR secretion into the maternal and fetal circuits of the ex vivo dually perfused placental lobule to confirm that placenta secretes TTR into the fetal circulation. We also investigated translocation of Alexa Fluor-594 labelled TTR from incubation medium into the fetal placental capillaries in early (14–15 weeks) and term placental villus explants.Results: The perfused placental lobule secretes TTR into the maternal and fetal circuits. Secretion in both circuits is linear with time and is predominantly into the maternal circuit (mean maternal/fetal ratio 99.4 ± 25.6). The mean data fitted well to a three compartment mathematical model (maternal circuit, placenta and fetal circuit, constant secretion of TTR and return of maternal circuit TTR to the placental compartment). Explants from early (14–15 weeks) and late (38–40 weeks) placentas translocated fluorescently labelled TTR from medium to villus (fetal) capillaries.Conclusions: Our results confirm that human placenta secretes TTR into maternal and fetal circulations and supports the hypothesis that placental TTR secreted into the maternal placental circulation can be taken up by trophoblasts and translocated to the fetal circulation, forming a TTR shuttle system. This may have important implications for materno-fetal transfer of thyroid hormones, retinol/retinol binding protein and xenobiotics (such as polychlorinated biphenyls) all of which bind to TTR.

Placental drug transporters and their role in fetal protection - Corrected Proof

M. Iqbal, M.C. Audette, S. Petropoulos, W. Gibb, S.G. Matthews — 2012-01-24

Abstract: The human placenta has a number of protective mechanisms that help to prevent potentially harmful compounds from entering the fetal compartment. Two important transporter proteins are phospho-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) which are mainly expressed in the syncytiotrophoblast where they actively extrude a wide range of xenobiotics. The expression profile of these transporters varies with advancing gestation. P-gp has been shown to decline near term, leaving the fetus susceptible to potentially teratogenic drugs commonly administered to pregnant women (i.e. synthetic glucocorticoids, selective serotonin reuptake inhibitors, glyburide, antiretrovirals, etc.). Drug transporter expression is regulated by a number of transcription factors, and steroid hormones present during pregnancy, such as progesterone, estrogen and corticosteroids. Drug transporter levels have also been found to be altered in pathological pregnancies (preterm, pre-eclampsia, growth restriction and infection). Genetic variation in the genes that encode these drug transporters can significantly alter transporter function and may play a significant role in determining the susceptibility of a fetus to maternally-administered therapeutic drugs. Understanding the regulation of placental drug transporters in normal and pathological pregnancies is critical to further our knowledge of fetal development, and may lead to the development of more selectively-targeted maternal and fetal drug treatments.

A distinct microvascular endothelial gene expression profile in severe IUGR placentas - Corrected Proof

2012-01-20

Abstract: The placental microvasculature is essential for efficient transfer of gases, nutrients and waste between the mother and fetus. Microvascular hypoplasia of the terminal villi is a common pathology in severe Intra Uterine Growth Restriction (IUGR). We used novel methods to obtain placental micro-vascular endothelial cells (PlMEC) from preterm control placentas (n = 3) and placentas from pregnancies with severe IUGR (n = 6) with absent or reversed end-diastolic velocity in the umbilical artery. Distal placental villous tissue was collected to enrich for intermediate and terminal villi. Tissue was digested and PlMEC positively selected using tocosylated magnetic Dynabeads labeled with Human Endothelial Antigen lectin. The purity of the PlMEC (94 ± 2 SD %) was assessed by CD31 and vimentin immunocytochemistry. RNA was extracted from the PlMEC samples and subjected to Affymetrix microarray analysis (U133Plus2 array chips). Comparison of preterm and IUGR PlMEC gene expression profiles identified BTNL9 and NTRK2 transcripts to be upregulated and SAA1 and SLAMF1 transcripts to be downregulated in all 6 IUGR cases relative to preterm controls. A third downregulated gene GNAS was identified to be near significance. Changes were demonstrated to be significant at the mRNA level by Real Time PCR in the PlMEC samples. Changes in the IUGR endothelium were confirmed at the protein level by immunohistochemistry for the 3 with available antibodies. We used a tissue microarray constructed from an independent cohort of placental samples from severe IUGR (n = 7), preeclamptic (n = 7), preterm control (n = 6) and term control (n = 6) pregnancies. Results confirmed differential endothelial expression of BTNL9, NTRK2 and SLAMF1 in IUGR versus preterm and term samples. These studies are the first to characterize PlMEC gene expression profiles thus we have advanced our understanding of the molecular basis of placental micro-vascular pathophysiology in fetal growth restriction.

Apoptotic DC-SIGN+ cells in normal human decidua - Corrected Proof

2012-01-19

Abstract: Background: Normal pregnancy and spontaneous abortion in humans and mice are associated with immune responses. The decidua harbors dendritic cells identifiable in humans by their expression of DC-SIGN. Because dendritic cells are essential for immune response regulation, decidual DC-SIGN+ cells may play a role in normal or pathological pregnancy outcomes. Previous reports suggested that DC interact with NK cells in decidua, although the functional significance of this phenomenon remains unknown.Objective: We studied the presence of conjugates of DC-SIGN+ cells with CD56+ NK cells in normal human decidua.Methods: Conjugates of DC-SIGN+ cells with CD56+ NK cells were studied in leukocyte suspensions of normal human decidua (6–11 weeks) by flow cytometry and confocal microscopy. The presence of apoptotic cells was determined by the TUNEL assay, incubation with annexin V and confocal microscopy in decidual leukocyte suspensions and by the TUNEL assay in decidual sections.Results: We observed conjugates of decidual DC-SIGN+ cells with CD56+ NK cells (40.2±26.1% of all the DC-SIGN+ cells by flow cytometry and 52.3±10.2% by confocal microscopy). We also found that a proportion of DC-SIGN+ cells were in apoptosis, since they were TUNEL+ (40.2±7.2% of all DC-SIGN+ cells in decidual sections) and annexin V+ (34.4±15.2% in leukocyte suspensions). And sorted DC-SIGN+ cells had multilobulated nuclei.Conclusions: The conjugates of decidual DC-SIGN+ cells with CD56+ NK cells strongly suggest that these latter cells induce apoptosis in DC-SIGN+ cells during normal pregnancy. We discuss this possibility in the context of maternal–fetal tolerance.

Arterio-arterial vascular anastomoses in monochorionic twin placentas with and without twin anemia-polycythemia sequence - Corrected Proof

2012-01-18

Abstract: We performed a matched case–control study to analyze the placental angioarchitecture, in particular the diameter of arterio-arterial (AA) anastomoses in monochorionic placentas from pregnancies with spontaneous twin anemia-polycythemia sequence (TAPS) compared to a control group of uncomplicated monochorionic placentas. Placental angioarchitecture was analyzed using colored dye injection. AA anastomoses were detected in 20% (3/15) of spontaneous TAPS placentas. The median diameter of AA anastomoses in the group with and without TAPS was 0.4 mm and 2.2 mm, respectively (p = 0.01). In conclusion, AA anastomoses are rarely detected in TAPS placentas. When present, the AA anastomosis is very small, preventing equilibration of hemoglobin levels between both twins.

Stability of reference proteins in human placenta: General protein stains are the benchmark - Corrected Proof

D. Lanoix, J. St-Pierre, A.-A. Lacasse, M. Viau, J. Lafond, C. Vaillancourt — 2012-01-16

Abstract: The stability of reference proteins in semi-quantitative Western blot experiments in normal and diseased placenta has never been studied. This study aims to determine the stability of five reference proteins and two general protein stains in placentas from preeclampsia, gestational diabetes mellitus and matched control pregnancies. The stability of the reference proteins was analysed using indicators of inter-group (P value) and intra-group (coefficient of variation) stability. The effect of different normalization strategies was determined by normalizing serotonin transporter (SERT) expression against the different reference protein markers. Results show significant expression variability of β-actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine phosphoribosyltransferase 1 (HPRT1), peptidylprolyl isomerase A (PPIA) and α-tubulin, and that amido black staining is the most stable reference protein marker. Furthermore, results show that SERT expression significantly differs according to the reference protein markers used for its normalization. The present study demonstrated the importance of using stable reference protein markers and normalization strategy in order to get correct results in semi-quantitative Western blot experiments in placental tissues.

Investigation of confined placental mosaicism by CGH in IVF and ICSI pregnancies - Corrected Proof

E. Chan Wong, C. Hatakeyama, A. Minor, S. Ma — 2012-01-12

Abstract: Background: Assisted reproductive technologies include in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). It has been shown that embryos derived from ART have higher rates of aneuploidy. Although the majority of ART pregnancies are genetically normal, it is suspected that aneuploid embryos may persist as mosaics and lead to confined placental mosaicism (CPM). Due to the greater risks of sperm aneuploidy in infertile men, CPM may be more prevalent in ICSI than IVF pregnancies. In this report, we investigated the prevalence of CPM in IVF and ICSI pregnancies using comparative genomic hybridization and flow cytometry.Methods: The placenta and umbilical cord blood were collected after birth. To determine the presence of CPM, karyotypes of umbilical cord blood were compared to the results of placental analyses. For each placenta, multiple villous sites were investigated for DNA gains/losses and polyploidy using comparative genomic hybridization and flow cytometry. Detected abnormalities were further confirmed by fluorescent in-situ hybridization (FISH).Results: In total, 134 IVF/ICSI cases were investigated. CPM was detected in five of these cases (5/134) giving an overall rate of 3.73%. CPM was detected in one IVF case (1/31; 3.23%) and four ICSI cases (4/103; 3.88%). The prevalence of CPM in IVF and ICSI pregnancies was not statistically different from each other. CPM was not observed in 13 ICSI and 6 IVF cases that were determined to be small for gestational age (SGA).Conclusions: The prevalence of CPM in ICSI pregnancies is not greater than IVF pregnancies. In addition, the overall prevalence of CPM in ART pregnancies (IVF and ICSI) is similar to that of the general population. CPM was not observed in the limited cases that were affected by small for gestational age. Our results suggest that ART pregnancies are not at a greater risk for CPM.

Galectin fingerprinting detects differences in expression profiles between bovine endometrium and placentomes as well as early and late gestational stages - Corrected Proof

2012-01-12

Abstract: The concept of a network within the family of adhesion/growth regulatory galectins implies distinct spatio-temporal expression profiles. To test this assumption immunohistochemically for bovine placenta, placentomal (P) and interplacentomal tissues (IP) were collected at a slaughterhouse from the three stages of pregnancy (early gestation = day 30–130; mid gestation = day 130–220; late gestation = day 220–275). The specimens were snap-frozen or fixed in Bouin’s solution, then embedded in paraffin. Gene expression for galectins-1, -3, -4 and -9 in P and IP of late gestational stages was monitored by RT-PCR. Galectin-type-specific antibodies were used for immunohistochemical localization. In IP, galectin-1 was present in stroma cells and early gestational trophoblast giant cells (TGC), whereas galectin-3 was confined to uterine epithelial cells. In contrast, both galectins were found in epithelia of P tissue. Uterine epithelial cells and blood vessel walls were positive for galectin-4, while galectin-9 was detected predominantly in uterine epithelial cells and late gestational TGC. Our study thus reveals individual profiles among the galectins tested, an indication for specific functions exerted by each protein in the bovine endometrium and placenta.

The characterization of fibrocyte-like cells: A novel fibroblastic cell of the placenta - Corrected Proof

2012-01-09

Abstract: The placenta is a highly vascularized organ thus angiogenesis is a key process in placental development. The contribution that different cells in the villous stroma play in placental angiogenesis is largely unknown. In this study we identified a novel stromal cell type in sections of term placenta which is morphologically fibroblastic and expressing the fibroblast marker TE-7 but also positive for the monocytic markers CD115 and CD14 and designated these cells as fibrocyte-like cells. Populations of fibrocyte-like cells from the placenta were isolated by two methods: culture of adherence-selected placental cells and, for higher purity, by CD45 fluorescence activated cell sorting (FACS).Fibrocyte-like cell conditioned medium increased endothelial tubule-like structure formation 2-fold versus control medium. Both pro-angiogenic growth factors vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) and the anti-angiogenic factor soluble-Flt were found in the conditioned medium. Neutralizing antibodies against VEGF and b-FGF reduced endothelial cell tubule-like structures to control levels. These data suggests that fibrocyte-like cells, a previously unidentified cell of the villous stroma, may play an important role in the regulation of placental angiogenesis.

Crim1 has an essential role in glycogen trophoblast cell and sinusoidal-trophoblast giant cell development in the placenta - Corrected Proof

D.J. Pennisi, G. Kinna, H.S. Chiu, D.G. Simmons, L. Wilkinson, M.H. Little — 2012-01-09

Abstract: Normal placental development and function is essential for fetal growth of eutherian mammals. Mutational studies have shown that numerous growth factors are required for placental development and differentiation of placental lineages. Here, using a gene-trap mutant mouse line, Crim1KST264, we show that Crim1 is essential for murine placental development. Crim1 is a developmentally expressed, trans-membrane regulator of growth factor activity. Crim1KST264/KST264 mutant placentae displayed hypoplasia from 13.5 dpc, and altered structure from 15.5 dpc, including alterations in cell number in both the junctional and labyrinth zones. Using the reporter gene from the Crim1KST264 allele, we found that Crim1 is expressed in multiple cell types of the placenta, including strong expression in the spongiotrophoblast cells of the junctional zone. In the junctional zone of Crim1KST264/KST264 placentae, there was an increase in the glycogen trophoblast cells adjacent to the spongiotrophoblast cells. In the labyrinth zone, we found a decrease in the density of sinusoidal-trophoblast giant cells. Our findings show that Crim1 is required for placental development, and is necessary for the proper differentiation of sinusoidal-trophoblast giant cells and glycogen trophoblast cells.

A perfusion confusion – The authors’ reply - Corrected Proof

S. Collins, L. Impey — 2012-01-09

We thank Dr Leslie and Professor Thilaganathan for their comments on our case report . They infer that we have not measured the uterine artery, but a collateral pelvic vessel supplying the placenta. They base this on the absence of the external iliac artery from our images. This vessel is indeed an essential landmark for the identification of the uterine artery and the optimal point of insonation when a normal gravid uterus has expanded out of the pelvis in the second trimester. However, although the pregnancy itself was late second trimester, it was abdominal. Therefore the uterus did not contain the fetus and was the size of a normal uterus of around 12 weeks’ gestation. Uterine artery Doppler assessment in the first trimester requires a different technique as the uterus and the uterine vessels are anatomically lower . The external iliac arteries are not an essential landmark for this: ‘a sagittal section of the uterus and endocervical canal is visualised and the probe gently tilted to identify the uterine arteries in colour Doppler as aliasing vessels coursing along the side of the cervix and uterus’ . Pulsed wave Doppler is then used to obtain flow velocity waveforms from the ascending branch of the uterine artery at the point closest to the internal os. This is what we did, and is why the external iliac artery is not seen in our images. Indeed, it is logical to assume that there is likely to be less distortion of the uterine vessel if sampled at this point.

Altered placental methyl donor transport in the dexamethasone programmed rat - Corrected Proof

C.S. Wyrwoll, D. Kerrigan, M.C. Holmes, J.R. Seckl, A.J. Drake — 2012-01-09

Abstract: There is increasing evidence for a role for epigenetic modifications in early life ‘programming’ effects. Altered placental methyl donor transport may impact on the establishment of epigenetic marks in the fetus. This study investigated the effects of prenatal glucocorticoid overexposure on placental methyl donor transport. Glucocorticoids increased folate but decreased choline transport and reduced fetal plasma methionine levels. There was no change in global DNA methylation in fetal liver. These data suggest prenatal glucocorticoid overexposure causes complex alterations in the placental transport of key methyl donors which may have important implications for maternal diet and nutrient supplementation in pregnancy.

Transfer of gangliosides across the human placenta - Corrected Proof

M.D. Mitchell, K. Henare, B. Balakrishnan, E. Lowe, B.Y. Fong, P. Mcjarrow — 2012-01-09

Abstract: Objectives: Gangliosides are structural and functional glycosphingolipids, considered to have important roles in neuronal development in fetal and neonatal development and in memory formation. In this report, we have investigated the ability of bovine milk-derived gangliosides GM3 and GD3 to cross the human placenta.Study design: We have employed the ex-vivo model of dually-perfused isolated human placental lobules.Results: There was significant uptake of both GD3 and GM3 from the maternal perfusate. There was significant increase of GM3 in the fetal side and a non-statistically significant trend for GD3 to increase on the fetal side.Conclusions: Hence an apparent preference for GM3 release into fetal circulation. We suggest that gangliosides consumed by the mother enter her circulation, can be transferred across the placenta and may be available to the developing fetus for building neural connections.

A placental sub-proteome: The apical plasma membrane of the syncytiotrophoblast - Corrected Proof

D.D. Vandré, W.E. Ackerman, A. Tewari, D.A. Kniss, J.M. Robinson — 2012-01-06

Abstract: As a highly vascularized tissue, the placenta mediates gas and solute exchange between maternal and fetal circulations. In the human placenta, the interface with maternal blood is a unique epithelial structure known as the syncytiotrophoblast. Previously we developed a colloidal-silica based method to generate highly enriched preparations of the apical plasma membrane of the syncytiotrophoblast. Using similar preparations, a proteomics assessment of this important sub-proteome has identified 340 proteins as part of this apical membrane fraction. The expression of 38 of these proteins was previously unknown in the human placental syncytiotrophoblast. Together with previous studies, the current proteomic database expands our knowledge of the proteome of the syncytiotrophoblast apical plasma membrane from normal placentas to include more than 500 proteins. This database is a valuable resource for future comparisons to diseased placentas. Additionally, this data set provides a basis for further experimental studies of placenta and trophoblast function.

DNA methylation of stress-related genes and LINE-1 repetitive elements across the healthy human placenta - Corrected Proof

A.L. Non, A.M. Binder, L. Barault, R.C. Rancourt, L.D. Kubzansky, K.B. Michels — 2012-01-06

Abstract: Objectives: DNA methylation is known to play a critical role in regulating development of placental morphology and physiology. The methylation of genes mediated by glucocorticoid hormones may be particularly vulnerable to intrauterine stress in the placenta. However little is known about DNA methylation of stress-related genes within a healthy placenta, and particularly whether methylation occurs uniformly across different regions of the placenta, which is a critical question for researchers seeking to analyze methylation patterns. We examined DNA methylation across four regions of the placenta to evaluate methylation levels of stress-related genes within a healthy placenta, and to evaluate whether methylation patterns vary by sampling location.Study design: We evaluated levels of DNA methylation of three stress-related genes: NR3C1, BDNF, and 11B-HSD2 and of the repetitive element, LINE-1, in four different sample locations of 20 healthy placentas.Main outcome measures: Pyrosequencing was used to quantify levels of methylation at CpG sites within the promoter regions of each of the three stress-related genes, and global methylation of LINE-1.Results: Very low levels of methylation were found across all three stress-related genes; no gene showed a median methylation level greater than 4.20% across placental regions. Variation in methylation between placental regions for stress-related genes and for LINE-1 was minimal.Conclusions: Our data suggest that these frequently studied stress-related genes have low levels of methylation in healthy placenta tissue. Minimal variation between sites suggests that sampling location does not affect DNA methylation analyses of these genes or of LINE-1 repetitive elements.

Variety in placental shape: When does it originate? - Corrected Proof

C.M. Salafia, M. Yampolsky, A. Shlakhter, D.H. Mandel, N. Schwartz — 2012-01-05

Abstract: Objectives: Observational and empirical evidence suggest that the average placental shape is round with a centrally inserted umbilical cord. Yet variability of shape is common. When in pregnancy do shape and cord insertion variations originate?Materials and methods: Placental measures from published datasets obtained ultrasonographically at 11–14 weeks and/or at term were correlated.Results: Significant correlations were found between the normalized distance of cord insertion to the margin at 11–14 weeks with the same quantity at delivery (r = 0.509, p < 0.0001). First trimester cord marginality was not correlated with two measures of roundness of the delivered placenta (p = 0.448, and p = 0.812). There was a strong correlation between delivered placental thickness and first trimester cord marginality (r = −0.368, p = 0.009). There was a significant relationship between the cord marginality at 11–14 weeks and the mean chorionic vascular density at delivery (r = −0.287, p = 0.015). Placental position in the uterine cavity influences cord marginality at delivery. Modeling suggests that placental growth in the first trimester is non-round. Placental shape at 11–14 weeks is found to be irregular. This irregularity is not correlated with the roundness of the delivered placenta. Both empirically, and in the context of IVF pregnancies, deformation of the vasculogenic zone yields a bi-lobate placental shape.Conclusions: Our findings strongly support the hypothesis that abnormal cord insertion and a multi-lobate shape result from early influences on the placental growth, such as the shape of the vasculogenic zone, or placental position in the uterus, rather than trophotropism later in pregnancy.

Pro-inflammatory cytokine-stimulated first trimester decidual cells enhance macrophage-induced apoptosis of extravillous trophoblasts - Corrected Proof

Z.-M. Wu, H. Yang, M. Li, C.-C. Yeh, F. Schatz, C.J. Lockwood, W. Di, S.J. Huang — 2012-01-04

Abstract: Objective: As human blastocyst-derived extravillous trophoblasts (EVTs) invade the early decidua, they are positioned to interact with immune cells and resident decidual cells, and remodel spiral arteries into high capacity vessels that increase blood flow to the developing fetal-placental unit. Shallow EVT invasion elicits incomplete vascular transformation and reduces uteroplacental blood flow that presages adverse pregnancy outcomes. Excess macrophages in the decidua induce EVT apoptosis via tumor necrosis factor-alpha (TNF-α) secretion. Our previous observation that pro-inflammatory cytokines enhance neutrophil and macrophage activator granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in first trimester decidual cells is now extended to include: 1) the specific macrophage activator M-CSF; 2) macrophage activation and subsequent enhancement of EVT apoptosis by both GM-CSF and M-CSF.Study design: Quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay assessed M-CSF expression in first trimester decidual cells incubated with interleukin-1 beta (IL-1β) or TNF-α. Peripheral monocyte-derived macrophages pre-incubated with conditioned media from decidual cell cultures were co-cultured with a first trimester EVT cell line, HTR-8/SVneo cells. Macrophage activation was examined and EVT apoptosis evaluated by DNA fragmentation, caspase activation and cell membrane asymmetry.Results: IL-1β or TNF-α significantly enhanced M-CSF expression in first trimester decidual cells. The conditioned media from these cultures activates macrophages, which promote caspase 3/7-dependent EVT apoptosis with antibodies against GM-CSF or M-CSF blocking this effect.Conclusions: Pro-inflammatory cytokines increases synthesis of M-CSF in first trimester decidual cells. Both GM-CSF and M-CSF activate macrophages, which initiate caspase-dependent EVT apoptosis.

TMED2/p24β1 is expressed in all gestational stages of human placentas and in choriocarcinoma cell lines - Corrected Proof

A. Zakariyah, W. Hou, R. Slim, L. Jerome-Majewska — 2012-01-04

Abstract: Members of the transmembrane emp24 domain (Tmed)/p24 family of proteins are required for transport of proteins between the endoplasmic reticulum and the Golgi. One member of this family, Tmed2/p24β1, is expressed during placental development in mice and its expression is required for normal development of the labyrinth layer. Although TMED2 is conserved in humans, little is known about its expression and function in human placenta. We examined TMED2 expression in human placenta between 5.5 and 40 weeks of gestation and showed that TMED2 is expressed in syncytiotrophoblast, cytotrophoblast, and stromal cells. We also found high levels of TMED2 expression in BeWo but not in JEG-3 choriocarcinoma cell line. We used the BeWo cell line to determine TMED2 subcellular localization in placental cells and show its co-localization with the endoplasmic reticulum Golgi intermediate compartment. Our findings show conservation of TMED2 expression in human placenta and suggest that this protein may also play a role during placental development in humans.

A perfusion confusion? - Corrected Proof

K. Leslie, B. Thilaganathan — 2011-12-30

We read with interest the case report by Collins et al. (2011) who observed normal uterine artery Doppler indices in an abdominal pregnancy where the placenta was implanted into the right lateral pelvic side wall The authors inferred that normal (low resistance) uterine artery indices may develop in pregnancy even without a connection to the placental bed. They used this inference to challenge the widely held belief of a ‘cause and effect’ mechanism between trophoblast invasion and changes in the uterine artery waveform. The accompanying editorial very elegantly highlights the importance of some case reports in challenging perceived wisdoms and dogma, and calls for caution in the use and interpretation of Doppler studies .

Placental characteristics in growth-discordant monochorionic twins: A matched case-control study - Corrected Proof

E. Lopriore, S.A. Pasman, F.J. Klumper, J.M. Middeldorp, F.J. Walther, D. Oepkes — 2011-12-26

Abstract: Objective: To compare the placental characteristics in monochorionic (MC) twin pregnancies with and without birth weight discordance (BWD).Methods: We performed a matched case-control study to compare the placental characteristics of MC placentas from pregnancies with BWD (≥25%) (n = 47) with a control group of MC placentas without BWD (n = 47), matched for gestational age at birth. Placental sharing, angioarchitecture and diameter of the arterio-arterial (AA) anastomosis were assessed by placental injection with colored dye.Results: The rate of velamentous cord insertion in MC placentas with and without BWD was 30% (28/94) and 16% (15/94), respectively (p = 0.036). Placental sharing discordance in MC placentas with and without BWD was 36% and 17%, respectively (p < 0.001). The mean diameter of the AA anastomosis in MC placentas with and without BWD was 2.2 mm and 1.8 mm, respectively (p = 0.024).Conclusion: MC placentas from growth-discordant twins are more unequally shared, have a higher rate of velamentous cord insertions and larger diameter of AA anastomosis compared to gestational age matched controls.

Variation in Macrophage Migration Inhibitory Factor [MIF] immunoreactivity during bovine gestation - Corrected Proof

2011-12-26

Abstract: Macrophage Migration Inhibitory Factor (MIF) is a proinflammatory cytokine involved in several aspects of the immune response. MIF appears to play important roles in materno-fetal immuno-tolerance during placental establishment, modulation and growth as studied in epitheliochorial porcine and hemochorial human and mouse placentae. Here we studied the bovine placenta being multiplex, villous and synepitheliochorial with a low degree of invasion, to see if MIF could be involved. Placental tissues sampled from 12 cows at 9 stages of gestation (days 18–250), and endometrial tissues from two non-pregnant animals were processed for immunohistochemistry. Bovine MIF was detected by Western blot using anti-human MIF monoclonal antibodies. An immunoreactive band of approximately 12kDa confirmed similarities between bovine and human MIFs. Compared to the non-pregnant stage with very faint staining, the caruncular epithelium during pregnancy showed stronger staining for MIF. The intercaruncular epithelium in non-pregnant endometrium showed some reaction apically with increasing intensity at uterine gland openings; in contrast, at day 18 of gestation this staining was markedly increased. During gestation both caruncular and trophoblast epithelium of the placentomes were positive with different intensity in relation to the gestational stage. In the uterine glands, some strongly stained cells were present. The mature binucleated trophoblast giant cells were negative throughout pregnancy. During reestablishment of vascularisation, the vasculature in the caruncular area showed MIF reactivity. While supporting involvement of MIF in different placental types, the spatio-temporal variation in the bovine placenta suggests a regulatory role for MIF mainly in the interhemal barrier and during vascular development.