Connecting G protein-coupled estrogen receptor biomolecular mechanisms with the pathophysiology of preeclampsia: a review.

BACKGROUND: Throughout the course of pregnancy, small maternal spiral arteries that are in contact with fetal tissue undergo structural remodeling, lose smooth muscle cells, and become less responsive to vasoconstrictors. Additionally, placental extravillous trophoblasts invade the maternal decidua to establish an interaction between the fetal placental villi with the maternal blood supply. When successful, this process enables the transport of oxygen, nutrients, and signaling molecules but an insufficiency leads to placental ischemia. In response, the placenta releases vasoactive factors that enter the maternal circulation and promote maternal cardiorenal dysfunction, a hallmark of preeclampsia (PE), the leading cause of maternal and fetal death. An underexplored mechanism in the development of PE is the impact of membrane-initiated estrogen signaling via the G protein-coupled estrogen receptor (GPER). Recent evidence indicates that GPER activation is associated with normal trophoblast invasion, placental angiogenesis/hypoxia, and regulation of uteroplacental vasodilation, and these mechanisms could explain part of the estrogen-induced control of uterine remodeling and placental development in pregnancy. CONCLUSION: Although the relevance of GPER in PE remains speculative, this review provides a summary of our current understanding on how GPER stimulation regulates some of the features of normal pregnancy and a potential link between its signaling network and uteroplacental dysfunction in PE. Synthesis of this information will facilitate the development of innovative treatment options.

Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery.

Functional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue's scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

Prospective study of pregnancy and newborn outcomes in mothers with West nile illness during pregnancy.

BACKGROUND: A previous case report of West Nile virus (WNV) illness during pregnancy suggested that WNV could be a cause of congenital defects. We performed a prospective, longitudinal cohort study of pregnant women with WNV illness to increase our knowledge of the effects of WNV illness during pregnancy. METHODS: Participants were enrolled in 2005 to 2008 from pregnant women with serologically confirmed WNV illness reported to the Centers for Disease Control and Prevention. Comparison was made to WNV-uninfected women, matched on maternal age and enrollment month. Pregnancy and newborn data were collected; cord blood WNV serology was obtained. Pediatric exams and the Bayley Scales of Infant and Toddler Development-Third Edition (Bayley-III) were performed. RESULTS: Twenty-eight WNV-infected mothers and 25 WNV-uninfected mothers participated. Maternal demographics were similar except for a higher rate of planned pregnancies, education, and household income in the WNV-uninfected mothers. There were no differences in pregnancy and delivery characteristics except that infected mothers had a higher incidence of febrile illnesses and used more medications. Birth weight, length, head circumference, and rate of congenital malformations were similar in babies born to WNV-infected and -uninfected mothers. Follow-up physical exams were generally normal. The Bayley-III assessments, available for 17 children born to mothers with WNV illness, showed performance at or above age level across domains. CONCLUSION: The risk for adverse pregnancy and newborn outcomes in women experiencing WNV illness in pregnancy appears to be low, but future studies with larger numbers are needed to rule out a small risk. Birth Defects Research (Part A) 106:716-723, 2016. © 2016 Wiley Periodicals, Inc.

Kaposi's sarcoma-associated herpesvirus G-protein coupled receptor activates the canonical Wnt/ß-catenin signaling pathway.

BACKGROUND: KSHV is a tumorigenic γ-herpesvirus that has been identified as the etiologic agent of Kaposi's sarcoma (KS), a multifocal highly vascularized neoplasm that is the most common malignancy associated with acquired immunodeficiency syndrome (AIDS). The virus encodes a constitutively active chemokine receptor homologue, vGPCR that possesses potent angiogenic and tumorigenic properties, and is critical for KSHV pathobiology. To date, a number of signaling pathways have been identified as key in mediating vGPCR oncogenic potential. FINDINGS: In this study, we identify a novel pathway, the Wnt/ß-catenin pathway, which is dysregulated by vGPCR expression in endothelial cells. Expression of vGPCR in endothelial cells enhances the nuclear accumulation of ß-catenin, that correlates with an increase in ß-catenin transcriptional activity. Activation of ß-catenin signaling by vGPCR is dependent on the PI3K/Akt pathway, as treatment of vGPCR-expressing cells with a pharmacological inhibitor of PI3K, leads to a decreased activation of a ß-catenin-driven reporter, a significant decrease in expression of ß-catenin target genes, and reduced endothelial tube formation. CONCLUSIONS: Given the critical role of Wnt/ß-catenin signaling in angiogenesis and tumorigenesis, the findings from this study suggest a novel mechanism in KSHV-induced malignancies.

Developmental outcomes in young children born to mothers with West Nile illness during pregnancy.

BACKGROUND: West Nile virus (WNV) infection is associated with acute morbidity and mortality in adults and children. Information on the effects of maternal WNV illness during pregnancy on early childhood development is limited. This study was designed to examine the relationship between maternal WNV illness during pregnancy and birth and developmental outcomes at age 3 years. METHODS: Mother-child participants were identified using a national surveillance registry for women with WNV illness during pregnancy. Maternal and infant health data and relevant family characteristics were obtained through medical record reviews and maternal questionnaires. All infants received ophthalmologic examinations. Child development was evaluated at age 3 years using the Bayley Scales of Infant and Toddler Development-Third Edition (Bayley-III). RESULTS: As a group, the children's (N = 11) birth weight, head circumference, and infant ophthalmologic examination results were within age expectations; one child was born preterm (gestational age 36 weeks). Mean (SD) age at the time of Bayley-III testing was 36.7 (3.8) months. The group's mean performance on the Bayley-III was at or above age level in all domains, but one child showed a mild delay in the Adaptive domain. The variability observed in this sample (1/53 [1.9%] Domain scores < -2.0 SDs) was consistent with expectations based upon the distribution of Bayley-III Domain scores in the general population. CONCLUSION: Maternal WNV infection does not appear to be associated with global developmental delays in young children. These results are preliminary, however, and require confirmation in future research.

Differences in gastric carcinoma microenvironment stratify according to EBV infection intensity: implications for possible immune adjuvant therapy.

Epstein-Barr virus (EBV) is associated with roughly 10% of gastric carcinomas worldwide (EBVaGC). Although previous investigations provide a strong link between EBV and gastric carcinomas, these studies were performed using selected EBV gene probes. Using a cohort of gastric carcinoma RNA-seq data sets from The Cancer Genome Atlas (TCGA), we performed a quantitative and global assessment of EBV gene expression in gastric carcinomas and assessed EBV associated cellular pathway alterations. EBV transcripts were detected in 17% of samples but these samples varied significantly in EBV coverage depth. In four samples with the highest EBV coverage (hiEBVaGC - high EBV associated gastric carcinoma), transcripts from the BamHI A region comprised the majority of EBV reads. Expression of LMP2, and to a lesser extent, LMP1 were also observed as was evidence of abortive lytic replication. Analysis of cellular gene expression indicated significant immune cell infiltration and a predominant IFNG response in samples expressing high levels of EBV transcripts relative to samples expressing low or no EBV transcripts. Despite the apparent immune cell infiltration, high levels of the cytotoxic T-cell (CTL) and natural killer (NK) cell inhibitor, IDO1, was observed in the hiEBVaGCs samples suggesting an active tolerance inducing pathway in this subgroup. These results were confirmed in a separate cohort of 21 Vietnamese gastric carcinoma samples using qRT-PCR and on tissue samples using in situ hybridization and immunohistochemistry. Lastly, a panel of tumor suppressors and candidate oncogenes were expressed at lower levels in hiEBVaGC versus EBV-low and EBV-negative gastric cancers suggesting the direct regulation of tumor pathways by EBV.

Extravillous Trophoblast Migration and Invasion Assay.

Extravillous trophoblast (EVT) migration and invasion through the decidualized endometrium is essential to successful placentation. SGHPL-4 cells, an EVT cell line derived from first trimester placenta, is a widely used model of cytotrophoblast differentiation into an invasive phenotype. Here we describe a quantitative cell migration assay that can be modified to also measure cell invasion. SGHPL-4 cells were seeded into BD Fluoroblok cell culture inserts constructed with an 8 µm porous membrane and allowed to migrate towards epidermal growth factor, a known chemoattractant for EVTs. To assess EVT invasion, Fluoroblok inserts were first coated with Matrigel, a basement membrane matrix. SGHPL-4 cells were labeled with calcein AM and cells that had invaded and/or migrated across the membrane were quantified by a bottom-reading fluorescence plate reader. The advantage of the Fluoroblok inserts over other migration/invasion assays is that they allow nondestructive detection of migrated cells.

Two isoforms of the leptin receptor are enhanced in pregnancy-specific tissues and soluble leptin receptor is enhanced in maternal serum with advancing gestation in the baboon.

Leptin is a polypeptide hormone produced by adipose and other endocrine tissues. Although it has been linked to receptor-mediated pathways that directly influence human conceptus development, mechanisms that regulate the leptin receptor in pregnancy-specific tissues remain unclear. Therefore, we assessed leptin-receptor ontogeny and regulation in the baboon (Papio sp.), a primate model for human pregnancy. Placentae, decidua, and amniochorion were collected from baboons in early (Days 54-63, n = 4), mid (Days 98-103, n = 4), and late (Days 159-165, n = 4) gestation. Regulation by estrogen was assessed by elimination of androgen precursors via removal of the fetus (fetectomy) at midgestation and collection of tissues in late gestation (n = 4; term, approximately 184 days). Maternal serum was sampled with advancing gestation, and the abundance of soluble leptin receptor (solLepR), a potential mediator of gestational hyperleptinemia, was determined. Two placental leptin-receptor isoforms (130 and 150 kDa) increased (P < 0.04 and P < 0.02, respectively) in abundance with advancing gestation. Similarly, the 130-kDa isoform increased approximately fourfold (P < 0.0025) in decidua and approximately 10-fold (P < 0.015) in amniochorion between early and late gestation. Following fetectomy, maternal serum estradiol levels declined approximately 85% (P < 0.03), and the 150-kDa placental leptin-receptor isoform was reduced by more than half (P < 0.002). Maternal serum solLepR concentrations were correlated with gestational age (r = 0.52, P < 0.01) and were unaffected by fetectomy. The presence of leptin-receptor isoforms in pregnancy-specific tissues further denoted leptin's potential to directly influence conceptus development, whereas the 130-kDa solLepR identified in maternal serum suggested a means to facilitate the hyperleptinemia typical of primate pregnancy. Although estrogen did not appear to be the principal regulator of solLepR, it and other factors linked to advancing gestation may be implicated in the regulation of leptin-receptor synthesis.

Expression of placental low-density lipoprotein receptor-related protein and scavenger receptors AI/AII transcripts in the baboon.

OBJECTIVE: This study was undertaken to assess potential secondary lipoprotein-dependent mechanisms, scavenger receptor AI and AII (SR-AI and SR-AII), and low-density lipoprotein (LDL) receptor-related protein (LRP) in the baboon (Papio sp) placenta. STUDY DESIGN: Baboon placental villous tissue and enriched fractions of syncytiotrophoblast cells were collected at early (approximately day 60, n = 3), mid (approximately day 100, n = 4), and late (approximately day 160, n = 4) pregnancy (term = approximately 184 days). The abundance of messenger RNA (mRNA) transcripts for SR-AI, SR-AII, and LRP were determined relative to constitutively expressed, glyceraldehyde-3-phosphate-dehydrogenase (GAPDH). RESULTS: No quantitative differences (P >.05) in SR-AI, SR-AII, or LRP mRNAs were noted in respect to stage of gestation. However, SR-AII/GAPDH mRNA ratios in syncytiotrophoblast cells (0.38 +/- 0.09, n = 11) were significantly (P <.05) higher than in villous tissue (0.15 +/- 0.04, n = 11), whereas LRP/GAPDH mRNA ratios were higher in villous tissue (0.43 +/- 0.10, n = 11) than in syncytiotrophoblast cells (0.18 +/- 0.02, n = 11). CONCLUSION: SR-AII mRNA in baboon placenta appears to be expressed, in greatest abundance, in the endocrinologically active syncytiotrophoblast.

Placental endocrine disruption induced by cadmium: effects on P450 cholesterol side-chain cleavage and 3beta-hydroxysteroid dehydrogenase enzymes in cultured human trophoblasts.

We previously suggested that cadmium (Cd), an environmental toxicant and constituent of tobacco smoke, inhibits progesterone secretion in cultured human placental trophoblasts by inhibiting low-density lipoprotein receptor mRNA expression. In the current study, we investigated whether Cd also disrupts progesterone synthesis via P450 cholesterol side-chain cleavage (P450(scc)) and 3beta-hydroxysteroid dehydrogenase (3beta-HSD), enzymes that play important roles in placental steroidogenesis. Human cytotrophoblasts were purified by density gradient centrifugation and incubated in Dulbecco modified Eagle medium + 10% fetal bovine serum with 0, 5, 10, or 20 microM CdCl(2) for 96 h. Cells progressed to syncytiotrophoblastic maturity regardless of treatment. No differences (P > 0.05) in cell protein and lactate dehydrogenase activity were observed between untreated trophoblasts and those treated with CdCl(2). However, P450(scc) and 3beta-HSD mRNA transcript levels declined in a dose-dependent manner (P <0.05) in trophoblasts cocultured with 5, 10, or 20 microM CdCl(2). P450(scc) activity was similarly inhibited (P < 0.05) by CdCl(2) treatment, although 3beta-HSD activity was not significantly affected. Coculture with 8-bromo-cAMP enhanced progesterone secretion in untreated cultures but did not reverse the decline in progesterone secretion induced by CdCl(2) treatment. CdCl(2) failed to influence cAMP content in cultured cells. Collectively, results suggest that P450(scc) enzyme is another site at which Cd interferes with placental progesterone production. However, it is unlikely that an inhibition of cAMP is involved with the inhibition of progesterone biosynthesis by Cd in human trophoblasts.