Alcohol-induced premature permeability in mouse placenta-yolk sac barriers in vivo

Longitudinal intravital imaging of mouse placenta

Studying placental functions is crucial for understanding pregnancy complications. However, imaging placenta is challenging due to its depth, volume, and motion distortions. In this study, we have developed an implantable placenta window in mice that enables high-resolution photoacoustic and fluorescence imaging of placental development throughout the pregnancy. The placenta window exhibits excellent transparency for light and sound. By combining the placenta window with ultrafast functional photoacoustic microscopy, we were able to investigate the placental development during the entire mouse pregnancy, providing unprecedented spatiotemporal details. Consequently, we examined the acute responses of the placenta to alcohol consumption and cardiac arrest, as well as chronic abnormalities in an inflammation model. We have also observed viral gene delivery at the single-cell level and chemical diffusion through the placenta by using fluorescence imaging. Our results demonstrate that intravital imaging through the placenta window can be a powerful tool for studying placenta functions and understanding the placental origins of adverse pregnancy outcomes.

Prenatal alcohol exposure is associated with changes in placental gene co-expression networks

Alcohol consumption during pregnancy can result in a range of adverse postnatal outcomes among exposed children. However, identifying at-risk children is challenging given the difficulty to confirm prenatal alcohol exposure and the lack of early diagnostic tools. Placental surveys present an important opportunity to uncover early biomarkers to identify those at risk. Here, we report the first transcriptome-wide evaluation to comprehensively evaluate human placental pathways altered by fetal alcohol exposure. In a prospective longitudinal birth cohort in Cape Town, South Africa, we performed bulk tissue RNAseq in placenta samples from 32 women reporting heavy drinking during pregnancy and 30 abstainers/light drinkers. Weighted gene co-expression network analysis (WGCNA) and differential gene expression analysis were performed to assess associations between fetal alcohol exposure and placental gene expression patterns at a network-wide and single gene level, respectively. The results revealed altered expression in genes related to erythropoiesis and angiogenesis, which are implicated in established postnatal phenotypes related to alcohol exposure, including disruptions in iron homeostasis, growth, and neurodevelopment. The reported findings provide insights into the molecular pathways affected by prenatal alcohol exposure and highlight the potential of placental biomarkers for detecting and understanding the effects of alcohol on fetal development.

Expression of placental CD146 is dysregulated by prenatal alcohol exposure and contributes in cortical vasculature development and positioning of vessel-associated oligodendrocytes

Recent data showed that prenatal alcohol exposure (PAE) impairs the "placenta-brain" axis controlling fetal brain angiogenesis in human and preclinical models. Placental growth factor (PlGF) has been identified as a proangiogenic messenger between these two organs. CD146, a partner of the VEGFR-1/2 signalosome, is involved in placental angiogenesis and exists as a soluble circulating form. The aim of the present study was to investigate whether placental CD146 may contribute to brain vascular defects described in fetal alcohol spectrum disorder. At a physiological level, quantitative reverse transcription polymerase chain reaction experiments performed in human placenta showed that CD146 is expressed in developing villi and that membrane and soluble forms of CD146 are differentially expressed from the first trimester to term. In the mouse placenta, a similar expression pattern of CD146 was found. CD146 immunoreactivity was detected in the labyrinth zone and colocalized with CD31-positive endothelial cells. Significant amounts of soluble CD146 were quantified by ELISA in fetal blood, and the levels decreased after birth. In the fetal brain, the membrane form of CD146 was the majority and colocalized with microvessels. At a pathophysiological level, PAE induced marked dysregulation of CD146 expression. The soluble form of CD146 decreased in both placenta and fetal blood, whereas it increased in the fetal brain. Similarly, the expression of several members of the CD146 signalosome, such as VEGFR2 and PSEN, was differentially impaired between the two organs by PAE. At a functional level, targeted repression of placental CD146 by in utero electroporation (IUE) of CRISPR/Cas9 lentiviral plasmids resulted in (i) a decrease in cortical vessel density, (ii) a loss of radial vascular organization, and (iii) a reduced density of oligodendrocytes. Statistical analysis showed that the more the vasculature was impaired, the more the cortical oligodendrocyte density was reduced. Altogether, these data support that placental CD146 contributes to the proangiogenic "placenta-brain" axis and that placental CD146 dysfunction contributes to the cortical oligo-vascular development. Soluble CD146 would represent a promising placental biomarker candidate representative of alcohol-induced neurovascular defects in neonates, as recently suggested by PlGF (patents WO2016207253 and WO2018100143).

Involvement of metalloproteinase and nitric oxide synthase/nitric oxide mechanisms in early decidual angiogenesis-vascularization of normal and experimental pathological mouse placenta related to maternal alcohol exposure

Successful pregnancy for optimal fetal growth requires adequate early angiogenesis and remodeling of decidual spiral arterioles during placentation. Prior to the initiation of invasion and endothelial replacement by trophoblasts, interactions between decidual stromal cells and maternal leukocytes, such as uterine natural killer cells and macrophages, play crucial roles in the processes of early maternal vascularization, such as proliferation, apoptosis, migration, differentiation, and matrix and vessel remodeling. These placental angiogenic events are highly dependent on the coordination of several mechanisms at the early maternal-fetal interface, and one of them is the expression and activity of matrix metalloproteinases (MMPs) and endothelial nitric oxide synthases (NOSs). Inadequate balances of MMPs and nitric oxide (NO) are involved in several placentopathies and pregnancy complications. Since alcohol consumption during gestation can affect fetal growth associated with abnormal placental development, recently, we showed, in a mouse model, that perigestational alcohol consumption up to organogenesis induces fetal malformations related to deficient growth and vascular morphogenesis of the placenta at term. In this review, we summarize the current knowledge of the early processes of maternal vascularization that lead to the formation of the definitive placenta and the roles of angiogenic MMP and NOS/NO mechanisms during normal and altered early gestation in mice. Then, we propose hypothetical defective decidual cellular and MMP and NOS/NO mechanisms involved in abnormal decidual vascularization induced by perigestational alcohol consumption in an experimental mouse model. This review highlights the important roles of decidual cells and their MMP and NOS balances in the physiological and pathophysiological early maternal angiogenesis-vascularization during placentation in mice.

Early Abnormal Placentation and Evidence of Vascular Endothelial Growth Factor System Dysregulation at the Feto-Maternal Interface After Periconceptional Alcohol Consumption

Adequate placentation, placental tissue remodeling and vascularization is essential for the success of gestation and optimal fetal growth. Recently, it was suggested that abnormal placenta induced by maternal alcohol consumption may participate in fetal growth restriction and relevant clinical manifestations of the Fetal Alcohol Spectrum Disorders (FASD). Particularly, periconceptional alcohol consumption up to early gestation can alter placentation and angiogenesis that persists in pregnancy beyond the exposure period. Experimental evidence suggests that abnormal placenta following maternal alcohol intake is associated with insufficient vascularization and defective trophoblast development, growth and function in early gestation. Accumulated data indicate that impaired vascular endothelial growth factor (VEGF) system, including their downstream effectors, the nitric oxide (NO) and metalloproteinases (MMPs), is a pivotal spatio-temporal altered mechanism underlying the early placental vascular alterations induced by maternal alcohol consumption. In this review we propose that the periconceptional alcohol intake up to early organogenesis (first trimester) alters the VEGF-NO-MMPs system in trophoblastic-decidual tissues, generating imbalances in the trophoblastic proliferation/apoptosis, insufficient trophoblastic development, differentiation and migration, deficient labyrinthine vascularization, and uncompleted remodelation and transformation of decidual spiral arterioles. Consequently, abnormal placenta with insufficiency blood perfusion, vasoconstriction and reduced labyrinthine blood exchange can be generated. Herein, we review emerging knowledge of abnormal placenta linked to pregnancy complications and FASD produced by gestational alcohol ingestion and provide evidence of the early abnormal placental angiogenesis-vascularization and growth associated to decidual-trophoblastic dysregulation of VEGF system after periconceptional alcohol consumption up to mid-gestation, in a mouse model.

Selenium, a dietary-antioxidant with cardioprotective effects, prevents the impairments in heart rate and systolic blood pressure in adolescent rats exposed to binge drinking treatment

BACKGROUND

Binge drinking (BD) during adolescence is related to cardiovascular alterations. Selenium (Se) is an essential trace element with antioxidant, anti-inflammatory and antiapoptotic properties, essential for correct heart function.

OBJECTIVES

To study the protective cardiovascular effects of selenium in adolescent rats exposed to a BD-like procedure.

METHODS

32 adolescent male rats exposed to an intraperitoneally BD-like model or not, and supplemented with 0.4ppm of selenite or not, were divided into 4 groups: control, alcohol, control-selenium and alcohol-selenium. Blood pressure and heart rate (HR) were determined after experimentation. Se deposits, oxidative balance and the expression of glutathione peroxidases (GPxs), NF-kB and caspase-3 were measured in the heart. Also, DNA instability in rat lymphocytes and serum vascular markers were determined. Statistical analysis was performed with the ANOVA model.

RESULTS

The BD-like model depleted Se heart deposits (p < .01), decreased GPx activity (p < .01) and GPx1 (p < .001) and GPx4 (p < .05) expression, increased NF-kB (p < .01), caspase-3 (p < .001) expression, and generated oxidation in myocytes. Outside the heart, the BD-like model caused double-strand breaks in lymphocyte DNA and increased all the vascular markers measured. These cardiovascular alterations were related to higher systolic (p < .001) and diastolic (p < .05) blood pressure and HR (p < .05). In the heart, Se supplementation in BD-exposed rats significantly increased Se deposits (p < .001) and improved oxidative balance and vascular damage, including increased GPxs and decreased NF-kB and caspase-3 activation, consequently decreasing systolic (p < .05) blood pressure and HR (p < .01).

CONCLUSIONS

Se supplementation presents cardioprotective effects since it reversed HR and systolic blood pressure observed in BD-exposed adolescent rats.

Allogenic Use of Human Placenta-Derived Stromal Cells as a Highly Active Subtype of Mesenchymal Stromal Cells for Cell-Based Therapies

The application of mesenchymal stromal cells (MSCs) from different sources, including bone marrow (BM, bmMSCs), adipose tissue (atMSCs), and human term placenta (hPSCs) has been proposed for various clinical purposes. Accumulated evidence suggests that the activity of the different MSCs is indirect and associated with paracrine release of pro-regenerative and anti-inflammatory factors. A major limitation of bmMSCs-based treatment for autologous application is the limited yield of cells harvested from BM and the invasiveness of the procedure. Similar effects of autologous and allogeneic MSCs isolated from various other tissues were reported. The easily available fresh human placenta seems to represent a preferred source for harvesting abundant numbers of human hPSCs for allogenic use. Cells derived from the neonate tissues of the placenta (f-hPSC) can undergo extended expansion with a low risk of senescence. The low expression of HLA class I and II on f-hPSCs reduces the risk of rejection in allogeneic or xenogeneic applications in normal immunocompetent hosts. The main advantage of hPSCs-based therapies seems to lie in the secretion of a wide range of pro-regenerative and anti-inflammatory factors. This renders hPSCs as a very competent cell for therapy in humans or animal models. This review summarizes the therapeutic potential of allogeneic applications of f-hPSCs, with reference to their indirect pro-regenerative and anti-inflammatory effects and discusses clinical feasibility studies.

Epigallocatechin Gallate Ameliorates the Effects of Prenatal Alcohol Exposure in a Fetal Alcohol Spectrum Disorder-Like Mouse Model

Fetal alcohol spectrum disorder is the main preventable cause of intellectual disability in the Western world. Although binge drinking is the most studied prenatal alcohol exposure pattern, other types of exposure, such as the Mediterranean, are common in specific geographic areas. In this study, we analyze the effects of prenatal alcohol exposure in binge and Mediterranean human drinking patterns on placenta and brain development in C57BL/6J mice. We also assess the impact of prenatal treatment with the epigallocatechin-3-gallate antioxidant in both groups. Study experimental groups for Mediterranean or binge patterns: (1) control; (2) ethanol; (3) ethanol + epigallocatechin-3-gallate. Brain and placental tissue were collected on gestational Day 19. The molecular pathways studied were fetal and placental growth, placental angiogenesis (VEGF-A, PLGF, VEGF-R), oxidative stress (Nrf2), and neurodevelopmental processes including maturation (NeuN, DCX), differentiation (GFAP) and neural plasticity (BDNF). Prenatal alcohol exposure resulted in fetal growth restriction and produced imbalances of placental angiogenic factors. Moreover, prenatal alcohol exposure increased oxidative stress and caused significant alterations in neuronal maturation and astrocyte differentiation. Epigallocatechin-3-gallate therapy ameliorated fetal growth restriction, attenuated alcohol-induced changes in placental angiogenic factors, and partially rescued neuronal nuclear antigen (NeuN), (doublecortin) DCX, and (glial fibrillary acidic protein) GFAP levels. Any alcohol consumption (Mediterranean or binge) during pregnancy may generate a fetal alcohol spectrum disorder phenotype and the consequences may be partially attenuated by a prenatal treatment with epigallocatechin-3-gallate.

The Placenta as a Target for Alcohol During Pregnancy: The Close Relation with IGFs Signaling Pathway

Alcohol is one of the most consumed drugs in the world, even during pregnancy. Its use is a risk factor for developing adverse outcomes, e.g. fetal death, miscarriage, fetal growth restriction, and premature birth, also resulting in fetal alcohol spectrum disorders. Ethanol metabolism induces an oxidative environment that promotes the oxidation of lipids and proteins, triggers DNA damage, and advocates mitochondrial dysfunction, all of them leading to apoptosis and cellular injury. Several organs are altered due to this harmful behavior, the brain being one of the most affected. Throughout pregnancy, the human placenta is one of the most important organs for women's health and fetal development, as it secretes numerous hormones necessary for a suitable intrauterine environment. However, our understanding of the human placenta is very limited and even more restricted is the knowledge of the impact of toxic substances in its development and fetal growth. So, could ethanol consumption during this period have wounding effects in the placenta, compromising proper fetal organ development? Several studies have demonstrated that alcohol impairs various signaling cascades within G protein-coupled receptors and tyrosine kinase receptors, mainly through its action on insulin and insulin-like growth factor 1 (IGF-1) signaling pathway. This last cascade is involved in cell proliferation, migration, and differentiation and in placentation. This review tries to examine the current knowledge and gaps in our existing understanding of the ethanol effects in insulin/IGFs signaling pathway, which can explain the mechanism to elucidate the adverse actions of ethanol in the maternal-fetal interface of mammals.

Perigestational alcohol consumption induces altered early placentation and organogenic embryo growth restriction by disruption of trophoblast angiogenic factors

RESEARCH QUESTION

Maternal alcohol consumption produces fetal retardation and malformations, probably associated with placental defects. Does perigestational alcohol consumption up to organogenesis lead to abnormal placentation and embryo growth restriction by disrupting the vascular endothelial growth factor (VEGF) system in embryo-placental development?

DESIGN

Female mice were treated with 10% ethanol in drinking water before and up to day 10 of gestation. Control mice received ethanol-free water. After treatment, the trophoblastic tissue, embryo growth and the angiogenic VEGF pathway were analysed.

RESULTS

Female mice who had received treatment had resorbed and delayed implantation sites with poor ectoplacental cone development. Reduced trophoblastic area tissue from female mice who had received treatment had abnormal junctional zone and diminished labyrinthine vascularization. After treatment, the labyrinth had increased chorionic trophoblast proliferation, hypoxia inducible factor-1α immunoexpression but reduced apoptosis. The embryo growth was reduced concomitantly with low VEGF immunostaining but high endothelial nitric oxide synthase (eNOS) expression. In junctional and labyrinth of treated female mice, gene and protein immunoexpression of VEGF was reduced and the protein expression of FLT-1 increased compared with controls. Increased activation of kinase insert domain receptor receptor (phosphorylated KDR) and expression of eNOS were observed in placenta of treated female mice. Immunoexpression of metalloproteinase-9, however, was reduced in junctional zone but increased in labyrinth, compared with controls.

CONCLUSIONS

These data reveal inadequate expression of VEGF/receptors and angiogenic eNOS and metalloproteinase factors related to abnormal early placentation after perigestational alcohol ingestion, providing insight into aetiological factors underlying early placentopathy associated with intrauterine growth restriction caused by maternal alcohol consumption.

Murine Models for the Study of Fetal Alcohol Spectrum Disorders: An Overview

Prenatal alcohol exposure is associated to different physical, behavioral, cognitive, and neurological impairments collectively known as fetal alcohol spectrum disorder. The underlying mechanisms of ethanol toxicity are not completely understood. Experimental studies during human pregnancy to identify new diagnostic biomarkers are difficult to carry out beyond genetic or epigenetic analyses in biological matrices. Therefore, animal models are a useful tool to study the teratogenic effects of alcohol on the central nervous system and analyze the benefits of promising therapies. Animal models of alcohol spectrum disorder allow the analysis of key variables such as amount, timing and frequency of ethanol consumption to describe the harmful effects of prenatal alcohol exposure. In this review, we aim to synthetize neurodevelopmental disabilities in rodent fetal alcohol spectrum disorder phenotypes, considering facial dysmorphology and fetal growth restriction. We examine the different neurodevelopmental stages based on the most consistently implicated epigenetic mechanisms, cell types and molecular pathways, and assess the advantages and disadvantages of murine models in the study of fetal alcohol spectrum disorder, the different routes of alcohol administration, and alcohol consumption patterns applied to rodents. Finally, we analyze a wide range of phenotypic features to identify fetal alcohol spectrum disorder phenotypes in murine models, exploring facial dysmorphology, neurodevelopmental deficits, and growth restriction, as well as the methodologies used to evaluate behavioral and anatomical alterations produced by prenatal alcohol exposure in rodents.

Placental Myeloid Cells Protect against Zika Virus Vertical Transmission in a Rag1-Deficient Mouse Model

The ability of Zika virus (ZIKV) to cross the placenta and infect the fetus is a key mechanism by which ZIKV causes microcephaly. How the virus crosses the placenta and the role of the immune response in this process remain unclear. In the current study, we examined how ZIKV infection affected innate immune cells within the placenta and fetus and whether these cells influenced virus vertical transmission (VTx). We found myeloid cells were elevated in the placenta of pregnant ZIKV-infected Rag1-/- mice treated with an anti-IFNAR Ab, primarily at the end of pregnancy as well as transiently in the fetus several days before birth. These cells, which included maternal monocyte/macrophages, neutrophils, and fetal myeloid cells contained viral RNA and infectious virus, suggesting they may be infected and contributing to viral replication and VTx. However, depletion of monocyte/macrophage myeloid cells from the dam during ZIKV infection resulted in increased ZIKV infection in the fetus. Myeloid cells in the fetus were not depleted in this experiment, likely because of an inability of liposome particles containing the cytotoxic drug to cross the placenta. Thus, the increased virus infection in the fetus was not the result of an impaired fetal myeloid response or breakdown of the placental barrier. Collectively, these data suggest that monocyte/macrophage myeloid cells in the placenta play a significant role in inhibiting ZIKV VTx to the fetus, possibly through phagocytosis of virus or virus-infected cells.

[Fetal alcohol exposure: when placenta would help to the early diagnosis of child brain impairments]

Alcohol consumption during pregnancy constitutes a major cause of neurodevelopmental and behavioral disabilities. Whereas it is possible for clinicians to establish a perinatal diagnosis of fetal alcohol syndrome, the more severe expression of fetal alcohol spectrum disorder (FASD), most FASD children are late or mis-diagnosed due to a lack of clear morphological and neurodevelopmental abnormalities. Several precious years of care are consequently lost. Recent data revealed a functional placenta-brain axis involved in the control of the fetal brain angiogenesis which is impaired by in utero alcohol exposure. Because in the developing fetal brain a correct angiogenesis is required for a correct neurodevelopment, these preclinical and clinical advances pave the way for a new generation of placental biomarkers for early diagnosis of FASD.

Chemerin-induced macrophages pyroptosis in fetal brain tissue leads to cognitive disorder in offspring of diabetic dams

Background

Chemerin is highly expressed in the serum, placenta tissue, and umbilical cord blood of diabetic mother; however, the impact of chemerin on cognitive disorders of offspring from mothers with diabetes in pregnancy remains unclear.

Methods

A diabetic phenotype in pregnant mice dams was induced by streptozocin (STZ) injection or intraperitoneal injection of chemerin. Behavioral changes in offspring of diabetic dams and nondiabetic controls were assessed, and changes in chemerin, two receptors of chemerin [chemerin receptor 23 (ChemR23) and chemokine (C-C motif) receptor-like 2 (CCRL2)], macrophages, and neurons in the brain tissue were studied to reveal the underlying mechanism of the behavioral changes.

Results

Chemerin treatment mimicked the STZ-induced symptom of maternal diabetes in mice along with the altered behavior of offspring in the open field test (OFT) assay. In the exploring process for potential mechanism, the brain tissues of offspring from chemerin-treated dams were observed with an increase level of macrophage infiltration and a decrease number of neuron cells. Moreover, an increased level of NOD-like receptor family pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like (Asc) protein as well as pyroptosis [characterized by increased active caspase-1 content and secretion of cytokines such as interleukin (IL) 1 beta (IL-1β) and IL-18] more activated in macrophages is also observed in the brain of these diabetic dam’s offspring, in the presence of ChemR23. In vitro, it was found that pyroptosis activation was increased in macrophages separated from the abdominal cavity of normal mice, after chemerin treatment. However, depletion of CCRL2 decreased the level of chemerin in the brain tissues of diabetic dams’ offspring; depletion of ChemR23 decreased macrophage pyroptosis, and depletion of either receptor reversed chemerin-mediated neurodevelopmental deficits and cognitive impairment of offspring of diabetic pregnant dams.

Conclusions

Chemerin induced diabetic pregnant disease and CCRL2 were required to enrich chemerin in the brain of offspring. Aggregation of chemerin could lead to macrophage recruitment, activation of pyroptosis, the release of inflammatory cytokines, a decrease in the number of neurons, and cognitive impairment in offspring in a ChemR23-dependent manner. Targeting CCRL2 and/or ChemR23 could be useful for treating neuropsychological deficits in offspring of dams with diabetes in pregnancy.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1573-6) contains supplementary material, which is available to authorized users.

PLGF, a placental marker of fetal brain defects after in utero alcohol exposure

Most children with in utero alcohol exposure do not exhibit all features of fetal alcohol syndrome (FAS), and a challenge for clinicians is to make an early diagnosis of fetal alcohol spectrum disorders (FASD) to avoid lost opportunities for care. In brain, correct neurodevelopment requires proper angiogenesis. Since alcohol alters brain angiogenesis and the placenta is a major source of angiogenic factors, we hypothesized that it is involved in alcohol-induced brain vascular defects. In mouse, using in vivo repression and overexpression of PLGF, we investigated the contribution of placenta on fetal brain angiogenesis. In human, we performed a comparative molecular and morphological analysis of brain/placenta angiogenesis in alcohol-exposed fetuses. Results showed that prenatal alcohol exposure impairs placental angiogenesis, reduces PLGF levels and consequently alters fetal brain vasculature. Placental repression of PLGF altered brain VEGF-R1 expression and mimicked alcohol-induced vascular defects in the cortex. Over-expression of placental PGF rescued alcohol effects on fetal brain vessels. In human, alcohol exposure disrupted both placental and brain angiogenesis. PLGF expression was strongly decreased and angiogenesis defects observed in the fetal brain markedly correlated with placental vascular impairments. Placental PGF disruption impairs brain angiogenesis and likely predicts brain disabilities after in utero alcohol exposure. PLGF assay at birth could contribute to the early diagnosis of FASD.

Rat visceral yolk sac cells: viability and expression of cell markers during maternal diabetes

The function of the visceral yolk sac (VYS) is critical for embryo organogenesis until final fetal development in rats, and can be affected by conditions such as diabetes. In view of the importance of diabetes during pregnancy for maternal and neonatal health, the objective of this study was to assess fetal weight, VYS cell markers, and viability in female Wistar rats (200-250 g) with induced diabetes (alloxan, 37 mg/kg) on the 8th gestational day (gd 8). At gd 15, rats from control (n=5) and diabetic (n=5) groups were anesthetized and laparotomized to remove the uterine horns for weighing of fetuses and collecting the VYS. Flow cytometry was used for characterizing VYS cells, and for determining mitochondrial activity, cell proliferation, DNA ploidy, cell cycle phases, and caspase-3 activity. Fetal weight was reduced in the diabetic group. Expression of the cell markers CD34, VEGFR1, CD115, CD117, CD14, CCR2, CD90, CD44, STRO-1, OCT3/4, and Nanog was detected in VYS cells in both groups. In the diabetic group, significantly decreased expression of CD34 (P<0.05), CCR2 (P<0.001), and OCT3/4 (P<0.01), and significantly increased expression of CD90 (P<0.05), CD117 (P<0.01), and CD14 (P<0.05) were observed. VYS cells with inactive mitochondria, activated caspase-3, and low proliferation were present in the rats with diabetes. Severe hyperglycemia caused by maternal diabetes had negative effects on pregnancy, VYS cell viability, and the expression of cell markers.

Ethanol-induced impairment of polyamine homeostasis--a potential cause of neural tube defect and intrauterine growth restriction in fetal alcohol syndrome

INTRODUCTION

Polyamines play a fundamental role during embryogenesis by regulating cell growth and proliferation and by interacting with RNA, DNA and protein. The polyamine pools are regulated by metabolism and uptake from exogenous sources. The use of certain inhibitors of polyamine synthesis causes similar defects to those seen in alcohol exposure e.g. retarded embryo growth and endothelial cell sprouting.

METHODS

CD-1 mice received two intraperitoneal injections of 3 g/kg ethanol at 4 h intervals 8.75 days post coitum (dpc). The fetal head, trunk, yolk sac and placenta were collected at 9.5 and 12.5 dpc and polyamine concentrations were determined.

RESULTS

No measurable quantity of polyamines could be detected in the embryo head at 9.5 dpc, 12 h after ethanol exposure. Putrescine was not detectable in the trunk of the embryo at that time, whereas polyamines in yolk sac and placenta were at control level. Polyamine deficiency was associated with slow cell growth, reduction in endothelial cell sprouting, an altered pattern of blood vessel network formation and consequently retarded migration of neural crest cells and growth restriction.

DISCUSSION

Our results indicate that the polyamine pools in embryonic and extraembryonic tissues are developmentally regulated. Alcohol administration, at the critical stage, perturbs polyamine levels with various patterns, depending on the tissue and its developmental stage. The total absence of polyamines in the embryo head at 9.5 dpc may explain why this stage is so vulnerable to the development of neural tube defect, and growth restriction, the findings previously observed in fetal alcohol syndrome.

Metformin decreases the incidence of ovarian hyperstimulation syndrome: an experimental study

Background

In assisted reproduction cycles, gonadotropins are administered to obtain a greater number of oocytes. A majority of patients do not have an adverse response; however, approximately 3-6% develop ovarian hyperstimulation syndrome (OHSS). Metformin reduces the risk of OHSS but little is known about the possible effects and mechanisms of action involved.

Objective

To evaluate whether metformin attenuates some of the ovarian adverse effects caused by OHSS and to study the mechanisms involved.

Material and methods

A rat OHSS model was used to investigate the effects of metformin administration. Ovarian histology and follicle counting were performed in ovarian sections stained with Masson trichrome. Vascular permeability was measured by the release of intravenously injected Evans Blue dye (EB). VEGF levels were measured by commercially immunosorbent assay kit. COX-2 protein expression was evaluated by western blot and NOS levels were analyses by immunohistochemistry.

Results

Animals of the OHSS group showed similar physiopathology characteristics to the human syndrome: increased body weight, elevated progesterone and estradiol levels (P<0.001), increased number of corpora lutea (P<0.001), higher ovarian VEGF levels and vascular permeability (P<0.001 and P<0.01); and treatment with metformin prevented this effect (OHSS+M group; P<0.05). The vasoactive factors: COX-2 and NOS were increased in the ovaries of the OHSS group (P<0.05 and P<0.01) and metformin normalized their expression (P<0.05); suggesting that metformin has a role preventing the increased in vascular permeability caused by the syndrome.

Conclusion

Metformin has a beneficial effect preventing OHSS by reducing the increase in: body weight, circulating progesterone and estradiol and vascular permeability. These effects of metformin are mediated by inhibiting the increased of the vasoactive molecules: VEGF, COX-2 and partially NOS. Molecules that are increased in OHSS and are responsible for a variety of the symptoms related to OHSS.