Placental Explant Cultures Research Articles

Endoplasmic reticulum stress occurs in association with the extrusion of toxic extracellular vesicles from human placentae treated with antiphospholipid antibodies.

Antiphospholipid autoantibodies (aPLs), a major maternal risk factor for preeclampsia, are taken into the syncytiotrophoblast where they bind intracellular vesicles and mitochondria. Subsequently, large quantities of extracellular vesicles (EVs) extruded from syncytiotrophoblast into the maternal circulation are altered such that they cause maternal endothelial cell activation. However, the mechanism driving this change is unknown. First trimester placental explants were treated with aPL for 18 h. The EVs were then collected by different centrifugation. The levels of HSP 70, misfolded proteins, caspase 8 activity, and Mixed Lineage Kinase domain-Like (MLKL) were measured in placental explants and EVs. In addition, the levels of TNF-α and CD95 in conditioned medium were also measured. Treating placental explants with aPL caused an increase in levels of HSP 70, misfolded proteins and MLKL in placental explants and EVs. Increased activity of caspase 8 was also seen in placental explants. Higher levels of TNF-α were seen conditioned medium from aPL-treated placental explant cultures. aPLs appear to induce endoplasmic reticulum stress in the syncytiotrophoblast in a manner that involved caspase 8 and TNF-α. To avoid accumulation of the associated misfolded proteins and MLKL, the syncytiotrophoblast exports these potentially dangerous proteins in EVs. It is likely that the dangerous proteins that are loaded into placental EVs in preeclampsia contribute to dysfunction of the maternal cells.

Localization of Indoleamine 2,3-Dioxygenase-1 and Indoleamine 2,3-Dioxygenase-2 at the Human Maternal-Fetal Interface

Immunohistochemical localization of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, the first and rate-limiting enzyme in tryptophan metabolism along the kynurenine pathway, has been studied in order to better understand the physiological significance of these enzymes at the maternal-fetal interface of human pregnancy with a gestational age of 7 weeks (n = 1) and term placentas (37-40 weeks of gestation, n = 5). Indoleamine 2,3-dioxygenase-1 protein immunoreactivity was found in glandular epithelium of the decidua and the endothelium of the fetal blood vessels in the villous stroma with some additional positive cells in the villous core and in the decidua. The syncytiotrophoblast stained strongly for indoleamine 2,3-dioxygenase-2. Immunoreactivity of kynurenine, the immediate downstream product of indoleamine 2,3-dioxygenase-mediated tryptophan metabolism, showed the same localization as that of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, suggesting these are functional enzymes. Interferon-γ added to placental villous explant culture markedly stimulated expression level of both mRNA and immunoreactivity of indoleamine 2,3-dioxygenase-1. The different cellular expression and interferon-γ sensitivity of these enzymes at the maternal-fetal interface suggests distinct physiological roles for each enzyme in normal human viviparity.

Tissue factor and thrombomodulin: Determination of mRNA levels in exosomes derived from human placental explant cultures.

Excoriation (skin picking) disorder is included in the DSM-5 in the obsessive compulsive and related disorders category. It is defined as the recurrent urge to touch, scratch, scrape, scrub, rub, squeeze, bite or dig in the skin, leading to skin lesions. It is a rare disorder (1.4–5.4% of the population) and occurs mainly in women.this article reports the case of a 31-year-old female patient, initially assessed by dermatology and orthopaedics for the presence of infected ulcerated lesions on her lower limbs, with other superficial lesions from scratching on her chest, arms, forearms, back and head. The patient also reported symptoms of anxiety, so was assessed by consultation-liaison psychiatry.skin picking, normal behaviour in mammals, becomes pathological from a psychiatric point of view when it is repetitive and persistent, as in the case of excoriation disorder. In view of the reported relationship with the obsessive-compulsive spectrum, use of selective serotonin reuptake inhibitors and cognitive behavioural therapy are recommended.El trastorno por excoriación está incluido en el DSM - 5 dentro de la categoría de trastorno obsesivo compulsivo y trastornos relacionados. Se define como la urgencia de tocar, rascar, frotar, restregar, friccionar, apretar, morder o excavar la piel de forma recurrente hasta producirse lesiones cutáneas. Es un trastorno poco frecuente (1.4 - 5.4% de la población) y se presenta principalmente en mujeres.Se presenta el caso de una mujer de 31 años quien fue valorada por dermatología y ortopedia por presencia de lesiones ulceradas e infectadas en miembros inferiores, junto con otras lesiones superficiales por rascado en tórax, brazos, antebrazos, espalda y cabeza; además reportando síntomas ansiosos, razón por la cual es valorada por el servicio de Psiquiatría de enlace.El rascado cutáneo, conducta normal en los mamíferos, cobra valor patológico desde el punto de vista psiquiátrico al ser un acto repetitivo y persistente, como la conducta que se presenta en el trastorno por excoriación. Dada la relación descrita con el espectro obsesivo - compulsivo, se recomienda el uso de inhibidores selectivos de la recaptación de serotonina y la terapia cognitivo conductual.

Evaluation of FasL and TRAIL in exosomes derived from placental explant cultures of women with early- and late-onset preeclampsia.

El proyecto DIADA, entendido como una experiencia de implementación de un modelo de atención en salud mental, en el contexto de un país de medianos ingresos como Colombia, incentiva la necesaria discusión acerca de su papel en el marco de la salud mental global. El siguiente artículo expone los puntos principales en los que ocurre esta relación, entendiendo cómo el proyecto contribuye a la salud mental global, y de forma paralela, cómo la salud mental global nutre el desarrollo de este proyecto. Se reflexiona sobre aspectos como el tamizaje sistemático de pacientes con trastornos mentales, el uso de tecnologías en salud, la adopción del modelo colaborativo, la investigación en implementación, el aprendizaje colaborativo y el sistema de salud colombiano, puntos claves al momento de interpretar este ciclo de retroalimentación entre lo individual y lo global. El análisis de estos componentes demuestra cómo el aprendizaje colaborativo es un eje central en el crecimiento de la salud mental global, desde la incorporación de metodologías, implementación de modelos, evaluación de desenlaces y, finalmente, la difusión de los resultados obtenidos entre actores locales, regionales e internacionales.The DIADA project, understood as a mental healthcare implementation experience in the context of a middle-income country like Colombia, promotes a necessary discussion about its role in the global mental health framework. The following article outlines the main points by which this relationship occurs, understanding how the project contributes to global mental health and, at the same time, how global mental health nurtures the development of this project. It reflects on aspects like the systematic screening of patients with mental illness, the use of technology in health, the adoption of a collaborative model, the investigation on implementation, a collaborative learning and the Colombian healthcare system. These are all key aspects when interpreting the feedback cycle between the individual and the global. The analysis of these components shows how collaborative learning is a central axis in the growth of global mental health: from the incorporation of methodologies, implementation of models, assessment of outcomes and, finally, the dissemination of results to local, regional and international stakeholders.

Identification of optimal conditions for human placental-explant culture

Identification of optimal conditions for human placental-explant culture

Pro- and anti-inflammatory effects of sulforaphane on placental cytokine production

Placental inflammation increases the risk of adverse pregnancy outcomes and possibly neurodevelopmental disorders in the offspring. Previous research suggests it may be possible to modulate the placental immune response to bacteria to favor an anti-inflammatory phenotype with dietary factors. Sulforaphane (SFN) is a dietary supplement with known anti-inflammatory activities, however, its effects on placental cytokine production are unclear. Therefore, we evaluated the effects of SFN on biomarkers of inflammation and neurodevelopment under basal conditions and a setting of mild infection. Placental explant cultures were established and treated with up to 10 μM SFN in the presence and absence of 107 CFU/ml heat-killed E. coli. Concentrations of IL-1β, TNF-α, IL-6, sgp130, HO-1 and BDNF in conditioned medium were quantified by immunoassay. SFN increased antioxidant HO-1 expression in the absence, but not the presence, of infection. SFN inhibited IL-1β and IL-10, but tended to promote, TNF-α production by bacteria-stimulated cultures. IL-6 and BDNF were inhibited by SFN irrespective of co-treatment with E.coli. A negative regulator of IL-6 signaling, sgp130, was increased by SFN under basal conditions, but not in E. coli-stimulated cultures. These results suggest that SFN has mixed effects on the placenta inhibiting both pro-inflammatory (IL-1β) and anti-inflammatory factors (IL-10) but promoting regulators of oxidative stress and inflammation (HO-1 and sgp130) in an infection-dependent manner.

48. ELABELA and placental development in pregnancy and preeclampsia

The peptide hormone ELABELA (ELA) was discovered in 2013 and found to be essential for zebrafish cardiovascular development through activation of the Apelin receptor (APLNR). In humans, ELA has been found to be expressed in adult kidney and prostate, and in embryonic pluripotent stem cells where it serves as a growth factor, but signals via a yet unidentified second receptor. To further investigate the contribution of ELA to mammalian development ELA knockout mice were generated. The knockout embryos showed clear cardiovascular defects, but also the placentas were affected, which may lead to preeclampsia-like symptoms in ELA knockout mothers. Indeed, the mice showed significantly increased blood pressure and proteinuria. Remarkably, infusion of synthetic ELA was able to entirely rescue blood pressure, proteinuria, and increase fetal birth weight. The above findings let to studying ELA in human placentation and preeclampsia (PE). ELA was localized in villous cytotrophoblasts and, as expected for a hormone, in the syncytiotrophoblast layer of first trimester placental tissues. High expression was also observed in invading extravillous trophoblasts. In trophoblast cell lines ELA addition significantly increased the invasive capacity of these cells as measured in transwell invasion assays. In first trimester placental explant cultures ELA changed the morphology of the extravillous outgrowth and decreased trophoblast proliferation. Interestingly, preliminary results suggest that these downstream effects of ELA are not initiated by ELA binding to the Apelin receptor, therefore the second unknown receptor must be considered instead. Finally, circulating ELA in plasma of healthy and PE pregnancies measured at multiple time points in gestation did not appear to be associated with PE development. However, ELA’s peptide properties were found to interfere with the initial measurements done. These technical issues therefore first need to be resolved before definite conclusions can be drawn on the applicability of ELA as potential PE biomarker.

Dendritic polyglycerol nanoparticles show charge dependent bio-distribution in early human placental explants and reduce hCG secretion

A thorough understanding of nanoparticle bio-distribution at the feto-maternal interface will be a prerequisite for their diagnostic or therapeutic application in women of childbearing age and for teratologic risk assessment. Therefore, the tissue interaction of biocompatible dendritic polyglycerol nanoparticles (dPG-NPs) with first- trimester human placental explants were analyzed and compared to less sophisticated trophoblast-cell based models. First-trimester human placental explants, BeWo cells and primary trophoblast cells from human term placenta were exposed to fluorescence labeled, ∼5 nm dPG-NPs, with differently charged surfaces, at concentrations of 1 µM and 10 nM, for 6 and 24 h. Accumulation of dPGs was visualized by fluorescence microscopy. To assess the impact of dPG-NP on trophoblast integrity and endocrine function, LDH, and hCG releases were measured. A dose- and charge-dependent accumulation of dPG-NPs was observed at the early placental barrier and in cell lines, with positive dPG-NP-surface causing deposits even in the mesenchymal core of the placental villi. No signs of plasma membrane damage could be detected. After 24 h we observed a significant reduction of hCG secretion in placental explants, without significant changes in trophoblast apoptosis, at low concentrations of charged dPG-NPs. In conclusion, dPG-NP’s surface charge substantially influences their bio-distribution at the feto-maternal interface, with positive charge facilitating trans-trophoblast passage, and in contrast to more artificial models, the first-trimester placental explant culture model reveals potentially hazardous influences of charged dPG-NPs on early placental physiology.

The reduction in circulating levels of estrogen and progesterone in women with preeclampsia.

Abnormalities in the development of placental vasculature in early pregnancy and the failure of transformation of the spiral arteries are associated with the pathogenesis of preeclampsia. Sex hormones influence neovascularisation during pregnancy. However the profiling of estrogen and progesterone in preeclampsia is controversial. In this study we investigated the serum levels of estrogen and progesterone in women with preeclampsia. Blood samples were collected from 86 preeclamptic and 97 gestation-matched normotensive pregnancies. The levels of 17β-estradiol (E2), progesterone and 2-methoxyestradiol (2-ME) in serum were measured. In addition, the levels of E2 and progesterone in conditioned media from preeclamptic or normotensive term placental explant cultures or placental explants that had been treated with hydrogen peroxide (H2O2) were measured. The expression of estrogen receptors (ER) and progesterone receptors (PR) in preeclamptic and control placentae were measured by immunohistochemistry. The serum levels of E2, progesterone and 2-ME were significantly reduced in women with preeclampsia compared to controls. There was no difference in the serum levels of E2 and progesterone between severe and mild or between early-onset and late-onset preeclampsia as well as between preeclampsia with and without fetal growth restriction (FGR). The levels of E2 and progesterone in preeclamptic placental explants cultures were significantly lower than in normotensive term placental explant cultures. Treatment with H2O2 was found to be associated with a reduction in E2 production by the placenta. We demonstrated lower levels of estrogen in preeclampsia and speculate that this reduction may be due to the impairment of placental function in preeclampsia.

Effect of polybrominated diphenyl ether congeners on placental cytokine production

Polybrominated diphenyl ethers (PBDEs) are pollutants that may increase the risk of preterm birth. In previous studies, we found that a mixture of PBDEs altered the expression of biomarkers for preterm birth by the placenta. However, there are 209 different PBDE congeners with different tissue distributions. How these different congeners may alter the production of immunomodulators by the placenta that help to maintain the survival of the fetal allograft is unclear. Therefore, we compared the effects 5 common congeners on basal and bacteria-stimulated cytokine production by the placenta. Placental explant cultures were incubated with 20 μM of PBDE congeners 47, 99, 100, 153, 209 or vehicle in the presence and absence of Escherichia coli for 20 h. Conditioned medium was harvested and concentrations of IL-1β, TNF-α, IL-6, sgp130, HO-1, IL-10, BDNF, and 8-IsoP quantified. For unstimulated cultures, all congeners, except for PBDE-47, reduced the production of IL-1β and IL-6 production was enhanced by PBDE-153. BDNF concentrations tended to be reduced by most PBDE congeners and IL-10 production was enhanced by PBDE-99, −153, and −209. 8-IsoP production was enhanced by PBDE-153, but not the other congeners. For bacteria-stimulated cultures, PBDE-47 increased IL-1β production and PBDE-47, −153, and −209 tended to reduce TNF-α production. IL-6 production was enhanced by all PBDEs except 153. IL-10 production was enhanced by all congeners except for PBDE-47. All congeners significantly enhanced BDNF and 8-IsoP. These results suggest that PBDEs can alter the expression of placental biomarkers in a congener and infection-dependent manner.

Isolation and Characterization of Extracellular Vesicles from Ex Vivo Cultured Human Placental Explants.

Ex vivo culture of human placental explants has long allowed placentologists to study the milieu of soluble factors secreted by the human placenta throughout gestation while retaining the correct three-dimensional structure of the placental villi. Here, we detail the placental explant culture method employed in our laboratory to collect extracellular vesicles which are known to be released by the human placenta throughout pregnancy from 6weeks of gestation. Using this method, at least three different populations of placental extracellular vesicles can be simultaneously collected from each placental sample, allowing for comparative analysis of the cargos and downstream effects of the different types of extracellular vesicles produced by the human placenta.

Abstract 037: Exaggerated Placental Ischemia-induced Hypertension in Endothelin Receptor Type B (ETB)-deficient Pregnant Rats s Independent of Increased sFlt-1 or ROS Levels

While the pathogenesis of preeclampsia is not fully understood, studies implicate placental ischemia. Reduced uterine perfusion pressure (RUPP)-induced placental ischemia/hypoxia in animal models stimulates release of factors like antiangiogenic sFlt-1 into the maternal circulation increasing vascular-renal ET-1. ET-1 promotes hypertension via reactive oxygen species (ROS). Blockade of vasoconstrictive ETA abolishes RUPP hypertension. Deficiency of vasodilatory ETB in rats leads to increased blood pressure in pregnancy. While ETB deficiency markedly enhances RUPP hypertension, it is unknown if there is exaggerated RUPP-induced sFlt-1, ET-1 or ROS levels in ETB-def rats. The hypothesis was tested that placental ischemia/hypoxia-induced release of sFlt-1 and circulating ET-1 and ROS are greater in ETB-def rats. Eighteen-week-old ETB-def and transgenic (Tg) control pregnant rats were generated with Wistar Hannover males. RUPP or Sham surgeries were on gestational day 14 and assessment of plasmas and placentas at day 19. RUPP increased placental sFlt-1 (pg/mg) similarly in RUPP ETB-def (781±113, N=5) vs Sham ETB-def (573±54, N=12) and RUPP Tg (631±62, N=5) vs Sham Tg (547±31, N=12) (P<0.05). In placental explant cultures, acute hypoxia (48 h 1% O2 vs normoxia 6% O2) stimulated a comparable release of sFlt-1 (pg/mg) in Sham ETB-def (2577±135 vs 2070±78) and Sham Tg (3208±318 vs 2553±107) (P<0.05). Unexpectedly, plasma sFlt-1 (pg/mL) was lower in RUPP ETB-def (153±48) vs Sham ETB-def (476±125) and RUPP Tg (238±32) vs Sham Tg (463±102) (P<0.05). Plasma ET-1 (fmol/L) was exaggerated in RUPP ETB-def (954±70) and greater in Sham ETB-def (735±43) vs RUPP Tg (122±14) or Sham Tg (142±41) (P<0.05). Plasma H2O2 (umol/L) was not exaggerated in RUPP ETB-def (5.4±1.2) or RUPP Tg (4.0±0.5) but was greater (P<0.05) in Sham ETB-def (6.2±0.3) vs Sham Tg (3.6±0.3). In conclusion, these data suggest in 1) normal pregnancy, ETB is crucial for blood pressure control by regulating bioavailable ET-1 to prevent ROS production and 2) placental ischemia, ETB reduces excess ET-1 to buffer hypertension independently of sFlt-1 or ROS. These data support ETB physiology as important in controlling blood pressure in pregnancy and its loss in mediating hypertension in preeclampsia.

Evidence that fetal death is associated with placental aging

The risk of unexplained fetal death or stillbirth increases late in pregnancy, suggesting that placental aging is an etiological factor. Aging is associated with oxidative damage to DNA, RNA, and lipids. We hypothesized that placentas at >41 completed weeks of gestation (late-term) would show changes consistent with aging that would also be present in placentas associated with stillbirths. We sought to determine whether placentas from late-term pregnancies and unexplained stillbirth show oxidative damage and other biochemical signs of aging. We also aimed to develop an invitro term placental explant culture model to test the aging pathways. We collected placentas from women at 37-39 weeks' gestation (early-term and term), late-term, and with unexplained stillbirth. We used immunohistochemistry to compare the 3 groups for: DNA/RNA oxidation (8-hydroxy-deoxyguanosine), lysosomal distribution (lysosome-associated membrane protein 2), lipid oxidation (4-hydroxynonenal), and autophagosome size (microtubule-associated proteins 1A/1B light chain 3B, LC3B). The expression of aldehyde oxidase 1 was measured by real-time polymerase chain reaction. Using a placental explant culture model, we tested the hypothesis that aldehyde oxidase 1 mediates oxidative damage to lipids in the placenta. Placentas from late-term pregnancies show increased aldehyde oxidase 1 expression, oxidation of DNA/RNA and lipid, perinuclear location of lysosomes, and larger autophagosomes compared to placentas from women delivered at 37-39 weeks. Stillbirth-associated placentas showed similar changes in oxidation of DNA/RNA and lipid, lysosomal location, and autophagosome size to placentas from late-term. Placental explants from term deliveries cultured in serum-free medium also showed evidence of oxidation of lipid, perinuclear lysosomes, and larger autophagosomes, changes that were blocked by the G-protein-coupled estrogen receptor 1 agonist G1, while the oxidation of lipid was blocked by the aldehyde oxidase 1 inhibitor raloxifene. Our data are consistent with a role for aldehyde oxidase 1 and G-protein-coupled estrogen receptor 1 in mediating aging of the placenta that may contribute to stillbirth. The placenta is a tractable model of aging in human tissue.

ADAM28 localizes to HLA-G+ trophoblasts and promotes column cell outgrowth

IntroductionTrophoblast progenitor cell differentiation towards the extravillous trophoblast (EVT) lineage initiates within proximal regions of anchoring columns of first trimester placental villi. While molecular processes controlling the initial stages of progenitor cell differentiation along the EVT pathway have been described, much remains unknown about factors important in distal column cell differentiation into invasive EVTs. ADAMs are proteases that regulate growth factor signaling, cell-matrix adhesion, and matrix proteolysis, and thus impact many processes relevant in placentation. Global gene expression studies identified the ADAM subtype, ADAM28, to be highly expressed in EVT-like trophoblasts, suggesting that it may play a role in EVT function. This study aims to test the functional importance of ADAM28 in column cell outgrowth and maintenance. MethodsADAM28 mRNA levels and protein localization were determined by qPCR and immunofluorescence microscopy analyses in purified placental villi cell populations and tissues. ADAM28 function in trophoblast column outgrowth was examined using ADAM28-targetting siRNAs in Matrigel-imbedded placental explant cultures. ResultsWithin placental villi, ADAM28 mRNA levels were highest in HLA-G+ column trophoblasts, and consistent with this, ADAM28 was preferentially localized to HLA-G+ trophoblasts within distal anchoring columns and decidual tissue. siRNA-directed loss of ADAM28 impaired trophoblast column outgrowth and resulted in increased apoptosis in matrix-invading trophoblasts. DiscussionOur findings suggest that ADAM28 promotes column outgrowth by providing survival cues within anchoring column cells. This study also provides insight into a possible role for ADAM28 in driving differentiation of column trophoblasts into invasive HLA-G+ EVT subsets.

Differential expression of thioredoxin binding protein-2/Txnip in human placenta: Possible involvement of hypoxia in its suppression during early pregnancy.

Thioredoxin binding protein-2 (TBP-2), which is identical to thioredoxin interacting protein (Txnip), controls cellular proliferation and differentiation. The aim of the present study was to compare TBP-2 protein and mRNA expression in human placenta during the three trimesters of pregnancy and to investigate the role of hypoxia in the change of these expressions in placental tissue. A secondary objective was to determine the gene expression of peroxisome proliferator-activated receptors (PPARs) in TBP-2 deficient placenta using TBP-2 gene disrupted mice (TBP-2-/- ). Protein and mRNA expression of TBP-2 in human placenta from each trimester were analyzed by immunohistochemistry, Western blots, and by quantitative reverse-transcriptase-polymerase chain reaction. The effect of hypoxia on TBP-2 expression was tested using an explant culture of human placenta. In TBP-2-/- mouse placenta, we detected PPAR mRNA expression. TBP-2 was located in syncytiotrophoblasts and cytotrophoblasts, and also in the endothelium in human placenta. Its expression in the placenta was low in the first trimester, and increased in the second and third trimesters. Hypoxia decreased TBP-2 mRNA and protein expression in human placental explant culture. In TBP-2-/- mice, placental mRNA levels of PPARα and γ were significantly suppressed compared with those in wild-type mice. Hypoxia suppresses TBP-2 gene expression, which may ultimately alter placental development.

Effects of chemotherapeutics on trophoblast cells in 2D, 3D and placental explant culture

Effects of chemotherapeutics on trophoblast cells in 2D, 3D and placental explant culture

In vivo localisation and vascular effects of nano-vesicles derived from normal first trimester human placentae

In vivo localisation and vascular effects of nano-vesicles derived from normal first trimester human placentae

Gelsolin is an endogenous inhibitor of syncytiotrophoblast extracellular vesicle shedding in pregnancy.

Preeclampsia, a pregnancy-specific inflammatory disorder, is characterized by high levels of anti-angiogenic protein, soluble fms-like tyrosine kinase 1 (sFlt1), in the maternal circulation. sFlt1 producing molecular machinery is present in syncytiotrophoblast extracellular vesicles that are released by the placenta into maternal plasma during normal pregnancy, a process greatly accelerated in preeclampsia. We hypothesized that syncytiotrophoblast extracellular vesicles exposes cytoplasmic actin to plasma resulting in depletion of plasma gelsolin (pGSN), an abundant plasma protein that scavenges circulating actin and other pro-inflammatory mediators. To test whether pGSN levels would be lower in preeclampsia and to assess whether recombinant human plasma gelsolin (rhpGSN) may promote placental health by decreasing shedding of syncytiotrophoblast extracellular vesicles. We tested pGSN levels in third trimester plasma samples from women with preeclampsia and non-hypertensive pregnancies. We then assessed whether rhpGSN may act as a negative regulator of syncytial shedding in placental explant culture and dynamic mechanical stretch studies. pGSN levels fall in late pregnancy and decline further in preeclampsia patients. Recombinant human pGSN (rhpGSN) at 100μg/ml limits spontaneous syncytiotrophoblast vesicle release and sFlt1 protein dissemination by normal placental explants. Higher rhpGSN doses (500μg/ml) also limit syncytiotrophoblast vesicle and sFlt1 dissemination from preeclamptic placental explants. rhpGSN also mitigates syncytiotrophoblast vesicle during dynamic mechanical stretch. 1) pGSN, an anti-inflammatory factor of maternal origin is reduced in preeclampsia and may contribute to disease progression and 2) exogenous rhpGSN supplementation can limit the dissemination of toxic syncytiotrophoblast vesicle that characterizes the disease state.

The xenoestrogens, bisphenol A and para-nonylphenol, decrease the expression of the ABCG2 transporter protein in human term placental explant cultures

Many endogenous and xenobiotic compounds are substrates and regulators of human placental ABC transporters. ABCG2 is protecting fetus against foreign chemicals. Environmental xenoestrogens, like bisphenol A (BPA) and p-nonylphenol (p-NP), mimic natural estrogens and can affect hormonal systems.Effects of BPA, p-NP, DES (diethylstilbestrol) and estradiol (E2), on ABCG2 expression were studied using human first trimester and term placental explants. Role of estrogen receptors (ER) in the effects of chemicals was studied by ER antagonist.Term placenta expressed less ABCG2 protein. In term placentas BPA (p < 0.05), p-NP (p < 0.01) and E2 (p < 0.05) decreased the ABCG2 protein expression after 48 h exposure while after 24 h exposure, only E2 decreased the expression (p < 0.05). The chemicals did not affect ABCG2 in first trimester placentas. The ER antagonist affected differently the responses of chemicals.In conclusion, environmental xenoestrogens downregulate placental ABCG2 protein expression depending on gestational age.

Expression of PAPPA2 in human fetomaternal interface and involvement in trophoblast invasion and migration.

Pregnancy-associated plasma protein-A 2 (PAPPA2) is a placental-enriched gene that is important for normal human placentation and defects in the gene can cause complications in pregnancy. Yet the exact expression pattern and role of PAPPA2 in the human fetomaternal interface are not clear. In this study, in situ hybridization (ISH) and immunohistochemistry (IHC) were employed to examine the spatial and temporal expression of PAPPA2 in the human fetomaternal interface. IHC results exhibited wide expression of PAPPA2 in the fetomaternal interface, with placental syncytiatrophoblast (STB) and extravillous trophoblast (EVT) showing strong expression and the cytotrophoblast (CTB) showing weak expression of PAPPA2. These results were confirmed by ISH. Quantitative reverse transcription-polymerase chain reaction and western blot showed the elevation of PAPPA2 in first trimester EVT differentiation and term CTB spontaneous syncytialization. PAPPA2-siRNA transfection significantly depressed the invasion and migration ability of a trophoblast cell line (HTR8/SVneo) in a transwell migration and Matrigel invasion model compared to a negative control siRNA (P < 0.05), also revealing that matrix metalloproteinase 9 (MMP9) secretion is downregulated. This was confirmed using a human first trimester placental villi explant culture model. Our results reveal the spatial and temporal expression of PAPPA2 in the human fetomaternal interface and show the positive regulatory role of PAPPA2 in human trophoblast invasion and migration through the secretion of MMP9.