Oxidative stress causes vascular dysfunction in the placenta

Oxidative stress on vessels at the maternal-fetal interface for female reproductive system disorders: Update

Considerable evidence shows that oxidative stress exists in the pathophysiological process of female reproductive system diseases. At present, there have been many studies on oxidative stress of placenta during pregnancy, especially for preeclampsia. However, studies that directly focus on the effects of oxidative stress on blood vessels at the maternal-fetal interface and their associated possible outcomes are still incomplete and ambiguous. To provide an option for early clinical prediction and therapeutic application of oxidative stress in female reproductive system diseases, this paper briefly describes the composition of the maternal-fetal interface and the molecular mediators produced by oxidative stress, focuses on the sources of oxidative stress and the signaling pathways of oxidative stress at the maternal-fetal interface, expounds the adverse consequences of oxidative stress on blood vessels, and deeply discusses the relationship between oxidative stress and some pregnancy complications and other female reproductive system diseases.

Maternal supply of cysteamine alleviates oxidative stress and enhances angiogenesis in porcine placenta

BACKGROUND

Oxidative stress in placenta is associated with the occurrence of adverse pregnancy outcomes in sow, but there are few satisfactory treatment strategies for these conditions. This study investigated the potential of cysteamine (CS) as an antioxidant protectant for regulating the reproductive performance, redox status, and placental angiogenesis of sows.

METHODS

The placental oxidative stress status and vascular density of piglets with different birth weights: < 1.0 kg (low birth weight, LBW) and 1.4-1.6 kg (normal birth weight, NBW) were evaluated, followed by allotting 84 sows to four treatments (n = 21) and feeding them with a basal diet supplemented with 0, 100, 300, or 500 mg/kg of CS from d 85 of gestation to d 21 of lactation, respectively. Placenta, serum, and colostrum samples of sows or piglets were collected, and the characteristics of sows and piglets were recorded. Furthermore, the in vivo results were validated using porcine vascular endothelial cells (PVECs).

RESULTS

Compared with the NBW placentae, the LBW placentae showed increased oxidative damage and were vulnerable to angiogenesis impairment. Particularly, H2O2-induced oxidative stress prompted intracellular reactive oxygen species generation and inhibited the tube formation and migration of PVECs as well as the expression of vascular endothelial growth factor-A (VEGF-A) in vitro. However, dietary CS supplementation can alleviate oxidative stress and improve the reproductive performance of sows. Specifically, compared with the control group, dietary 100 mg/kg CS could (1) decrease the stillbirth and invalid rates, and increase both the piglet birth weight in the low yield sows and the placental efficiency; (2) increase glutathione and reduce malondialdehyde in both the serum and the colostrum of sows; (3) increase the levels of total antioxidant capacity and glutathione in LBW placentae; (4) increase the vascular density, the mRNA level of VEGF-A, and the immune-staining intensity of platelet endothelial cell adhesion molecule-1 in the LBW placentae. Furthermore, the in vitro experiment indicated that CS pre-treatment could significantly reverse the NADPH oxidase 2-ROS-mediated inactivation of signal transducer and activator of transcription-3 (Stat3) signaling pathway induced by H2O2 inhibition of the proliferation, tube formation, and migration of PVECs. Meanwhile, inhibition of Stat3 significantly decreased the cell viability, tube formation and the VEGF-A protein level in CS pretreated with H2O2-cultured PVECs.

CONCLUSIONS

The results indicated that oxidative stress and impaired angiogenesis might contribute to the occurrence of LBW piglets during pregnancy, but CS supplementation at 100 mg/kg during late gestation and lactation of sows could alleviate oxidative stress and enhance angiogenesis in placenta, thereby increasing birth weight in low yield sows and reducing stillbirth rate. The in vitro data showed that the underlying mechanism for the positive effects of CS might be related to the activation of Stat3 in PVECs.

Cigarette Smoking during Pregnancy: Effects on Antioxidant Enzymes, Metallothionein and Trace Elements in Mother-Newborn Pairs

The effect of maternal smoking as a source of exposure to toxic metals Cd and Pb on superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, metallothionein (MT), Cd, Pb, Cu, Fe, Mn, Se and Zn concentrations were assessed in maternal and umbilical cord blood and placenta in 74 healthy mother-newborn pairs after term delivery. Sparse discriminant analysis (SDA) was used to identify elements with the strongest impact on the SOD, GPx and MT in the measured compartments, which was then quantified by multiple regression analysis. SOD activity was lower in maternal and cord plasma, and higher in the placenta of smokers compared to non-smokers, whereas GPx activity and MT concentration did not differ between the groups. Although active smoking during pregnancy contributed to higher maternal Cd and Pb concentrations, its contribution to the variability of SOD, GPx or MT after control for other elements identified by SDA was not significant. However, an impaired balance in the antioxidant defence observed in the conditions of relatively low-to-moderate exposure levels to Cd and Pb could contribute to an increased susceptibility of offspring to oxidative stress and risk of disease development later in life. Further study on a larger number of subjects will help to better understand complex interactions between exposure to toxic elements and oxidative stress related to maternal cigarette smoking.

Placentae for Low Birth Weight Piglets Are Vulnerable to Oxidative Stress, Mitochondrial Dysfunction, and Impaired Angiogenesis

Intrauterine growth restriction (IUGR) is associated with fetal mortality and morbidity. One of the most common causes of IUGR is placental insufficiency, including placental vascular defects, and mitochondrial dysfunction. In addition, a high level of oxidative stress induces placental vascular lesions. Here, we evaluated the oxidative stress status, mitochondrial function, angiogenesis, and nutrient transporters in placentae of piglets with different birth weights: <500 g (L), 500-600 g (LM), 600-700 g (M), and >700 g (H). Results showed that placentae from the L group had higher oxidative damage, lower adenosine triphosphate and citrate synthase levels, and lower vascular density, compared to those from the other groups. Protein expression of angiogenic markers, including vascular endothelial cadherin, vascular endothelial growth factor A, and platelet endothelial cell adhesion molecule-1, was the lowest in the L group placentae compared to the other groups. In addition, the protein levels of glucose transporters GLUT1 and GLUT3 were downregulated in the L group, compared to the other groups. Furthermore, oxidative stress induced by H2O2 inhibited tube formation and migration in porcine vascular endothelial cells. Collectively, placentae for lower birth weight neonates are vulnerable to oxidative damage, mitochondrial dysfunction, and impaired angiogenesis.

Occupational exposure to organic particles and combustion products during pregnancy and birth outcome in a nationwide cohort study in Sweden

Objective

To study if children of women exposed to organic particles and combustion products at work during pregnancy, have an increased risk of low birth weight, preterm birth or small for gestational age.

Methods

A nationwide cohort of all occupationally active mothers and their children from single births during 1994 to the end of 2012 (1 182 138 observations) was formed. Information on birth outcome was obtained from the medical birth register. Information on absence from work, education, occupation, age, nationality and smoking habits was obtained from national registers. A job exposure matrix (FINJEM) was used to assess the exposure.

Results

Pregnant women with low absence from work and high (>50th percentile) exposure to organic particles had an increased risk of giving birth to children with low birth weight (OR=1.19; 95% CI: 1.07 to 1.32), small for gestational age (OR=1.22; 95% CI: 1.07 to 1.38) or preterm birth (OR=1.17; 95% CI: 1.08 to 1.27). Subgroup analyses showed an increased risk of small for gestational age in association with exposure to oil mist. Exposure to oil mist and cooking fumes was associated with low birth weight. Paper and other organic dust was associated with preterm birth. Exposure to combustion products showed an increased risk of small for gestational age (OR=1.40; 95% CI: 1.15 to 1.71).

Conclusions

The results indicate that occupational exposure to organic particles or combustion products during pregnancy is associated with restriction of fetal growth and preterm birth. More studies are needed to confirm a casual association.

AP39, a Modulator of Mitochondrial Bioenergetics, Reduces Antiangiogenic Response and Oxidative Stress in Hypoxia-Exposed Trophoblasts: Relevance for Preeclampsia Pathogenesis

Although the cause of preeclampsia, a pregnancy complication with significant maternal and neonatal morbidity, has not been fully characterized, placental ischemia attributable to impaired spiral artery remodeling and abnormal secretion of antiangiogenic factors are thought to be important in the pathogenesis of the disease. Placental ischemia could impair trophoblast mitochondrial function and energy production, leading to the release of reactive oxygen species (ROS). ROS have been shown to stabilize hypoxia-inducible factor (HIF)-1α, which, in turn, may induce transcription of antiangiogenic factors, soluble fms-like tyrosine kinase 1 (sFLT1), and soluble endoglin in trophoblasts. Herein, we tested whether the angiogenic imbalance and oxidative stress in the preeclamptic placenta may be prevented by improving mitochondrial function. First, to evaluate the cause-effect relationship between mitochondrial function and sFLT1 production, a human trophoblast primary cell culture model was established in which hypoxia induced mitochondrial ROS production and concurrent sFLT1 increase. Second, treatment with AP39, a novel mitochondria-targeted hydrogen sulfide donor, prevented ROS production, reduced HIF-1α protein levels, and diminished sFLT1 production. Finally, AP39, a modulator of mitochondrial bioenergetics enhanced cytochrome c oxidase activity, reversed oxidative stress and antiangiogenic response in hypoxic trophoblasts. These results suggest that placental hypoxia induces ROS production, HIF-1α stabilization, and sFLT1 up-regulation; these pathophysiological alterations can be attenuated by mitochondrial-targeted antioxidants.

Oxidative Stress in Preeclampsia and Placental Diseases

Preeclampsia is a persistent hypertensive gestational disease characterized by high blood pressure and proteinuria, which presents from the second trimester of pregnancy. At the cellular level, preeclampsia has largely been associated with the release of free radicals by the placenta. Placenta-borne oxidative and nitrosative stresses are even sometimes considered as the major molecular determinants of the maternal disease. In this review, we present the recent literature evaluating free radical production in both normal and pathological placentas (including preeclampsia and other major pregnancy diseases), in humans and animal models. We then assess the putative effects of these free radicals on the placenta and maternal endothelium. This analysis was conducted with regard to recent papers and possible therapeutic avenues.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Selective Targeting of a Novel Vasodilator to the Uterine Vasculature to Treat Impaired Uteroplacental Perfusion in Pregnancy

Fetal growth restriction (FGR) in pregnancy is commonly caused by impaired uteroplacental blood flow. Vasodilators enhance uteroplacental perfusion and fetal growth in humans and animal models; however, detrimental maternal and fetal side effects have been reported. We hypothesised that targeted uteroplacental delivery of a vasodilator would enhance drug efficacy and reduce the risks associated with drug administration in pregnancy. Phage screening identified novel peptides that selectively accumulated in the uteroplacental vasculature of pregnant mice. Following intravenous injection, the synthetic peptide CNKGLRNK selectively bound to the endothelium of the uterine spiral arteries and placental labyrinth in vivo; CNKGLRNK-decorated liposomes also selectively bound to these regions. The nitric oxide donor 2-[[4-[(nitrooxy)methyl]benzoyl]thio]-benzoic acid methyl ester (SE175) induced significant relaxation of mouse uterine arteries and human placental arteries in vitro; thus, SE175 was encapsulated into these targeted liposomes and administered to healthy pregnant C57BL/6J mice or endothelial nitric oxide synthase knockout (eNOS-/-) mice, which exhibit impaired uteroplacental blood flow and FGR. Liposomes containing SE175 (0.44mg/kg) or PBS were administered on embryonic (E) days 11.5, 13.5, 15.5 and 17.5; fetal and placental weights were recorded at term and compared to mice injected with free PBS or SE175. Targeted uteroplacental delivery of SE175 had no effect on fetal weight in C57BL/6J mice, but significantly increased fetal weight and mean spiral artery diameter, and decreased placental weight, indicative of improved placental efficiency, in eNOS-/- mice; free SE175 had no effect on fetal weight or spiral artery diameter. Targeted, but not free SE175 also significantly reduced placental expression of 4-hydroxynonenal, cyclooxygenase-1 and cyclooxygenase-2, indicating a reduction in placental oxidative stress. These data suggest that exploiting vascular targeting peptides to selectively deliver SE175 to the uteroplacental vasculature may represent a novel treatment for FGR resulting from impaired uteroplacental perfusion.

Redox Properties of Tryptophan Metabolism and the Concept of Tryptophan Use in Pregnancy

During pregnancy, tryptophan (Trp) is required for several purposes, and Trp metabolism varies over time in the mother and fetus. Increased oxidative stress (OS) with high metabolic, energy and oxygen demands during normal pregnancy or in pregnancy-associated disorders has been reported. Taking the antioxidant properties of Trp and its metabolites into consideration, we made four hypotheses. First, the use of Trp and its metabolites is optional based on their antioxidant properties during pregnancy. Second, dynamic Trp metabolism is an accommodation mechanism in response to OS. Third, regulation of Trp metabolism could be used to control/attenuate OS according to variations in Trp metabolism during pregnancy. Fourth, OS-mediated injury could be alleviated by regulation of Trp metabolism in pregnancy-associated disorders. Future studies in normal/abnormal pregnancies and in associated disorders should include measurements of free Trp, total Trp, Trp metabolites, and activities of Trp-degrading enzymes in plasma. Abnormal pregnancies and some associated disorders may be associated with disordered Trp metabolism related to OS. Mounting evidence suggests that the investigation of the use of Trp and its metabolites in pregnancy will be meanful.

Mother's Pre-pregnancy BMI and Placental Candidate miRNAs: Findings from the ENVIRONAGE Birth Cohort

There is increasing evidence that the predisposition for development of chronic diseases arises at the earliest times of life. In this context, maternal pre-pregnancy weight might modify fetal metabolism and the child’s predisposition to develop disease later in life. The aim of this study is to investigate the association between maternal pre-pregnancy body mass index (BMI) and miRNA alterations in placental tissue at birth. In 211 mother-newborn pairs from the ENVIRONAGE birth cohort, we assessed placental expression of seven miRNAs important in crucial cellular processes implicated in adipogenesis and/or obesity. Multiple linear regression models were used to address the associations between pre-pregnancy BMI and placental candidate miRNA expression. Maternal pre-pregnancy BMI averaged (±SD) 23.9 (±4.1) kg/m². In newborn girls (not in boys) placental miR-20a, miR-34a and miR-222 expression was lower with higher maternal pre-pregnancy BMI. In addition, the association between maternal pre-pregnancy BMI and placental expression of these miRNAs in girls was modified by gestational weight gain. The lower expression of these miRNAs in placenta in association with pre-pregnancy BMI, was only evident in mothers with low weight gain (<14 kg). The placental expression of miR-20a, miR-34a, miR-146a, miR-210 and miR-222 may provide a sex-specific basis for epigenetic effects of pre-pregnancy BMI.

Excessive autophagy induces the failure of trophoblast invasion and vasculature: possible relevance to the pathogenesis of preeclampsia

INTRODUCTION

Preeclampsia affects 5-7% of all healthy pregnancies and is characterized by hypertension and proteinuria. Although the pathogenesis of preeclampsia is still not fully understood, a failure of spiral artery transformation and aberrant placental vasculature are considered to be facets of this disease. Studies have also implicated increased autophagic activity. In this study, we investigated whether oxidative stress could increase autophagic activity and consequently affect trophoblast invasion and the placental vasculature.

METHODS

Placentas from 18 pregnancies complicated by preeclampsia and from 18 uncomplicated pregnancies, trophoblast HTR8/SVneo cell line (HTR8/SVneo) extravillous trophoblasts, and human umbilical vein endothelial cells (HUVECs) were employed. The levels of autophagy markers LC3, Beclin-1 and autophagosome were quantified by immunohistochemistry, Western blotting and RT-PCR in placental tissue, and in trophoblasts and endothelial cells that had been treated with an oxidative stress inducer glucose oxidase. Trophoblast invasion and endothelial cell tube formation were assessed in HTR8/SVneo cells or HUVECs that had been treated with glucose oxidase.

RESULTS

The expression of LC3, Beclin-1 and autophagosome was significantly increased in placentas from pregnancies complicated by early-onset preeclampsia and in HTR8/SVneo cells and HUVECs treated with glucose oxidase. In addition, trophoblast invasion and endothelial cell tube formation were significantly reduced in HTR8/SVneo cells or HUVECs that had been treated with glucose oxidase.

CONCLUSION

Our data suggest that oxidative stress induces increased autophagy in trophoblasts or endothelial cells which affects trophoblast invasion and the placental vasculature. Excessive autophagic activity may be involved in the development of preeclampsia.

Ultrastructure of Placenta of Gravidas with Gestational Diabetes Mellitus

Objectives. Gestational diabetes mellitus (GDM) leads to an abnormal placental environment which may cause some structural alterations of placenta and affect placental development and function. In this study, the ultrastructural appearances of term placentas from women with GDM and normal pregnancy were meticulously compared. Materials and Methods. The placenta tissues of term birth from 10 women with GDM and 10 women with normal pregnancy were applied with the signed informed consent. The morphology of fetomaternal interface of placenta was examined using light microscopy (LM) and transmission electron microscopy (TEM). Results. On LM, the following morphological changes in villous tissues were found in the GDM placentas when compared with the control placentas: edematous stroma, apparent increase in the number of syncytial knots, and perivillous fibrin deposition. On TEM, the distinct ultrastructural alterations indicating the degeneration of terminal villi were found in the GDM placentas as follows: thickening of the basal membrane (BM) of vasculosyncytial membrane (VSM) and the VSM itself, significantly fewer or even absent syncytiotrophoblastic microvilli, swollen or completely destroyed mitochondria and endoplasmic reticulum, and syncytiotrophoblasts with multiple vacuoles. Conclusion. Ultrastructural differences exist between GDM and control placentas. The differences of placenta ultrastructure are likely responsible for the impairment of placental barrier and function in GDM.

Angiogenesis in the placenta: the role of reactive oxygen species signaling

Proper placental development and function are central to the health of both the mother and the fetus during pregnancy. A critical component of healthy placental function is the proper development of its vascular network. Poor vascularization of the placenta can lead to fetal growth restriction, preeclampsia, and in some cases fetal death. Therefore, understanding the mechanisms by which uterine stressors influence the development of the placental vasculature and contribute to placental dysfunction is of central importance to ensuring a healthy pregnancy. In this review we discuss how oxidative stress observed in maternal smoking, maternal obesity, and preeclampsia has been associated with aberrant angiogenesis and placental dysfunction resulting in adverse pregnancy outcomes. We also highlight that oxidative stress can influence the expression of a number of transcription factors important in mediating angiogenesis. Therefore, understanding how oxidative stress affects redox-sensitive transcription factors within the placenta may elucidate potential therapeutic targets for correcting abnormal placental angiogenesis and function.

Pregnant mice lacking indoleamine 2,3-dioxygenase exhibit preeclampsia phenotypes

Preeclampsia is a cardiovascular disorder of late pregnancy that is, commonly characterized by hypertension, renal structural damage and dysfunction, and fetal growth restriction. Prevailing etiologic models of this disorder include T-cell dysfunction as an initiating cause of preeclampsia. Indoleamine 2,3-dioxygenase (IDO), an enzyme that mediates the conversion of tryptophan to kynurenine, has been linked to preeclampsia in humans, and is known to regulate T-cell activity and an endothelial-derived relaxing factor. To test the hypothesis that IDO is causally involved in the pathogenesis of preeclampsia, mice deficient for IDO (IDO-KO) were generated on a C57BL/6 background. IDO-KO and wild-type C57BL/6 mice were bred, and preeclampsia phenotypes were evaluated during pregnancy. Pregnant IDO-KO mice exhibited pathognomonic renal glomerular endotheliosis, proteinuria, pregnancy-specific endothelial dysfunction, intrauterine growth restriction, and mildly elevated blood pressure compared to wild-type mice. Together these findings highlight an important role for IDO in the generation of phenotypes typical of preeclampsia. Loss of IDO function may represent a risk factor for the development of preeclampsia. By extension, increased IDO activity, reductions in IDO reactants, or increases in IDO products may represent novel therapeutic approaches for this disorder.

Maternal plasma fetuin-A concentration is lower in patients who subsequently developed preterm preeclampsia than in uncomplicated pregnancy: a longitudinal study

Objective: Fetuin-A is a negative acute phase protein reactant that acts as a mediator for lipotoxicity, leading to insulin resistance. Intravascular inflammation and insulin resistance have been implicated in the mechanisms of disease responsible for preeclampsia (PE). Maternal plasma concentrations of fetuin-A at the time of diagnosis of preterm PE are lower than in control patients with a normal pregnancy outcome. However, it is unknown if the changes in maternal plasma fetuin-A concentrations precede the clinical diagnosis of the disease. We conducted a longitudinal study to determine whether patients who subsequently developed PE had a different profile of maternal plasma concentrations of fetuin-A as a function of gestational age (GA) than those with uncomplicated pregnancies. Methods: A longitudinal case-control study was performed and included 200 singleton pregnancies in the following groups: (1) patients with uncomplicated pregnancies who delivered appropriate for gestational age (AGA) neonates (n = 160); and (2) patients who subsequently developed PE (n = 40). Longitudinal samples were collected at each prenatal visit and scheduled at 4-week intervals from the first or early second trimester until delivery. Plasma fetuin-A concentrations were determined by ELISA. Analysis was performed using mixed-effects models. Results: The profiles of maternal plasma concentrations of fetuin-A differ between PE and uncomplicated pregnancies. Forward analysis indicated that the rate of increase of plasma fetuin-A concentration in patients who subsequently developed PE was lower at the beginning of pregnancy (p = 0.001), yet increased faster mid-pregnancy (p = 0.0017) and reached the same concentration level as controls by 26 weeks. The rate of decrease was higher towards the end of pregnancy in patients with PE than in uncomplicated pregnancies (p = 0.002). The mean maternal plasma fetuin-A concentration was significantly lower in patients with preterm PE at the time of clinical diagnosis than in women with uncomplicated pregnancies (p < 0.05). In contrast, there were no significant differences in maternal plasma fetuin-A concentration in patients who developed PE at term. Conclusions: (1) The profile of maternal plasma concentrations of fetuin-A over time (GA) in patients who develop PE is different from that of normal pregnant women; (2) the rate of change of maternal plasma concentrations of fetuin-A is positive (increases over time) in the midtrimester of normal pregnancy, and negative (decreases over time) in patients who subsequently develop PE; (3) at the time of diagnosis, the maternal plasma fetuin-A concentration is lower in patients with preterm PE than in those with a normal pregnancy outcome; however, such differences were not demonstrable in patients with term PE.

Associations between prenatal exposure to air pollution, small for gestational age, and term low birthweight in a state-wide birth cohort

A range of health effects, including adverse pregnancy outcomes, have been associated with exposure to ambient concentrations of particulate matter (PM) and ozone (O3). The objective of this study was to determine whether maternal exposure to fine particulate matter (PM2.5) and O3 during pregnancy is associated with the risk of term low birthweight and small for gestational age infants in both single and co-pollutant models. Term low birthweight and small for gestational age were determined using all birth certificates from North Carolina from 2003 to 2005. Ambient air concentrations of PM2.5 and O3 were predicted using a hierarchical Bayesian model of air pollution that combined modeled air pollution estimates from the EPA׳s Community Multi-Scale Air Quality (CMAQ) model with air monitor data measured by the EPA׳s Air Quality System. Binomial regression, adjusted for multiple potential confounders, was performed. In adjusted single-pollutant models for the third trimester, O3 concentration was positively associated with small for gestational age and term low birthweight births [risk ratios for an interquartile range increase in O3: 1.16 (95% CI 1.11, 1.22) for small for gestational age and 2.03 (95% CI 1.80, 2.30) for term low birthweight]; however, inverse or null associations were observed for PM2.5 [risk ratios for an interquartile range increase in PM2.5: 0.97 (95% CI 0.95, 0.99) for small for gestational age and 1.01 (95% CI 0.97, 1.06) for term low birthweight]. Findings were similar in co-pollutant models and linear models of birthweight. These results suggest that O3 concentrations in both urban and rural areas may be associated with an increased risk of term low birthweight and small for gestational age births.

The placental pursuit for an adequate oxidant balance between the mother and the fetus

The placenta is the exchange organ that regulates metabolic processes between the mother and her developing fetus. The adequate function of this organ is clearly vital for a physiologic gestational process and a healthy baby as final outcome. The umbilico-placental vasculature has the capacity to respond to variations in the materno-fetal milieu. Depending on the intensity and the extensity of the insult, these responses may be immediate-, mediate-, and long-lasting, deriving in potential morphostructural and functional changes later in life. These adjustments usually compensate the initial insults, but occasionally may switch to long-lasting remodeling and dysfunctional processes, arising maladaptation. One of the most challenging conditions in modern perinatology is hypoxia and oxidative stress during development, both disorders occurring in high-altitude and in low-altitude placental insufficiency. Hypoxia and oxidative stress may induce endothelial dysfunction and thus, reduction in the perfusion of the placenta and restriction in the fetal growth and development. This Review will focus on placental responses to hypoxic conditions, usually related with high-altitude and placental insufficiency, deriving in oxidative stress and vascular disorders, altering fetal and maternal health. Although day-to-day clinical practice, basic and clinical research are clearly providing evidence of the severe impact of oxygen deficiency and oxidative stress establishment during pregnancy, further research on umbilical and placental vascular function under these conditions is badly needed to clarify the myriad of questions still unsettled.

Differences and similarities in the transcriptional profile of peripheral whole blood in early and late-onset preeclampsia: insights into the molecular basis of the phenotype of preeclampsiaa

OBJECTIVE

Preeclampsia (PE) can be sub-divided into early- and late-onset phenotypes. The pathogenesis of these two phenotypes has not been elucidated. To gain insight into the mechanisms of disease, the transcriptional profiles of whole blood from women with early- and late-onset PE were examined.

METHODS

A cross-sectional study was conducted to include women with: i) early-onset PE (diagnosed prior to 34 weeks, n=25); ii) late-onset PE (after 34 weeks, n=47); and iii) uncomplicated pregnancy (n=61). Microarray analysis of mRNA expression in peripheral whole blood was undertaken using Affymetrix microarrays. Differential gene expression was evaluated using a moderated t-test (false discovery rate <0.1 and fold change >1.5), adjusting for maternal white blood cell count and gestational age. Validation by real-time qRT-PCR was performed in a larger sample size [early PE (n=31), late PE (n=72) and controls (n=99)] in all differentially expressed genes. Gene ontology analysis and pathway analysis were performed.

RESULTS

i) 43 and 28 genes were differentially expressed in early- and late-onset PE compared to the control group, respectively; ii) qRT-PCR confirmed the microarray results for early and late-onset PE in 77% (33/43) and 71% (20/28) of genes, respectively; iii) 20 genes that are involved in coagulation (SERPINI2), immune regulation (VSIG4, CD24), developmental process (H19) and inflammation (S100A10) were differentially expressed in early-onset PE alone. In contrast, only seven genes that encoded proteins involved in innate immunity (LTF, ELANE) and cell-to-cell recognition in the nervous system (CNTNAP3) were differentially expressed in late-onset PE alone. Thirteen genes that encode proteins involved in host defense (DEFA4, BPI, CTSG, LCN2), tight junctions in blood-brain barrier (EMP1) and liver regeneration (ECT2) were differentially expressed in both early- and late-onset PE.

CONCLUSION

Early- and late-onset PE are characterized by a common signature in the transcriptional profile of whole blood. A small set of genes were differentially regulated in early- and late-onset PE. Future studies of the biological function, expression timetable and protein expression of these genes may provide insight into the pathophysiology of PE.

The anti-aging factor α-klotho during human pregnancy and its expression in pregnancies complicated by small-for-gestational-age neonates and/or preeclampsia

OBJECTIVE

α-klotho, a protein with anti-aging properties, has been involved in important biological processes, such as calcium/phosphate metabolism, resistance to oxidative stress, and nitric oxide production in the endothelium. Recent studies have suggested a role of α-klotho in endocrine regulation of mineral metabolism and postnatal growth in infants. Yet, the role of α-klotho during pregnancy remains largely unknown. The aim of this study was to determine whether maternal plasma concentration of α-klotho changes during pregnancy and evaluate its expression in pregnancies complicated by small for gestational age (SGA) and/or preeclampsia (PE).

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) non pregnant women (n = 37); (2) uncomplicated pregnancy (n = 130); (3) PE without an SGA neonate (PE; n = 58); (4) PE with an SGA neonate (PE and SGA; n = 52); and (5) SGA neonate without PE (SGA; n = 52). Plasma concentrations of α-klotho were determined by ELISA.

RESULTS

The median plasma α-klotho concentration was higher in pregnant than in non-pregnant women. Among women with an uncomplicated pregnancy, the median plasma concentration of α-klotho increased as a function of gestational age (Spearman Rho = 0.2; p = 0.006). The median (interquartile range) plasma concentration of α-klotho in women with PE and SGA [947.6 (762-2013) pg/mL] and SGA without PE [1000 (585-1567) pg/mL] were 21% and 17% lower than that observed in women with an uncomplicated pregnancy [1206.6 (894-2012) pg/mL], (p = 0.005 and p = 0.02), respectively. Additionally, there were no significant differences in the median plasma concentration of α-klotho between uncomplicated pregnancies and women with PE without an SGA neonate (p = 0.5).

CONCLUSION

Maternal plasma concentration of α-klotho was higher during pregnancy than in a non-pregnant state. Moreover, the median maternal plasma concentration of α-klotho was lower in mothers who delivered an SGA neonate than in those with an uncomplicated pregnancy regardless of the presence or absence of PE.

Comparison of dietary food and nutrient intakes by supplement use in pregnant and lactating women in Seoul

This study was performed to compare the dietary food and nutrient intakes according to supplement use in pregnant and lactating women in Seoul. The subjects were composed of 201 pregnant and 104 lactating women, and their dietary food intake was assessed using the 24-h recall method. General information on demographic and socioeconomic factors, as well as health-related behaviors, including the use of dietary supplements, were collected. About 88% and 60% of the pregnant and lactating women took dietary supplements, respectively. The proportion of dietary supplements used was higher in pregnant women with a higher level of education. After adjusting for potential confounders, among the pregnant women, supplement users were found to consume 45% more vegetables, and those among the lactating women were found to consume 96% more beans and 58% more vegetables. The intakes of dietary fiber and β-carotene among supplement users were higher than those of non-users, by 23% and 39%, respectively. Among pregnant women, the proportion of women with an intake of vitamin C (from diet alone) below the estimated average requirements (EAR) was lower among supplement users [users (44%) vs. non-users (68%)], and the proportion of lactating women with intakes of iron (from diet alone) below the EAR was lower among supplement users [usesr (17%) vs. non-users (38%)]. These results suggest that among pregnant and lactating women, those who do not use dietary supplements tend to have a lower intake of healthy foods, such as beans and vegetables, as well as a lower intake of dietary fiber and β-carotene, which are abundant in these foods, and non-users are more likely than users to have inadequate intake of micro-nutrient such as vitamin C and iron.

Maternal plasma concentrations of sST2 and angiogenic/anti-angiogenic factors in preeclampsia

OBJECTIVES

Angiogenic/anti-angiogenic factors have emerged as one of the promising biomarkers for the prediction of preeclampsia. Since not all patients with preeclampsia can be identified by these analytes, the search for additional biomarkers continues. The soluble form of ST2 (sST2), a protein capable of binding to interleukin (IL)-33 and thus contributing to a Th1-biased immune response, has been reported to be elevated in maternal plasma of women with preeclampsia. The aims of this study were to examine: (1) differences in maternal plasma concentrations of sST2 and IL-33 between women diagnosed with preeclampsia and those having uncomplicated pregnancies; (2) the relationship between sST2, umbilical and uterine artery Doppler velocimetry, and the severity of preeclampsia; and (3) the performance of sST2 and angiogenic/anti-angiogenic factors in identifying patients with preeclampsia at the time of diagnosis.

METHODS

This cross-sectional study included women with preeclampsia (n = 106) and women with an uncomplicated pregnancy (n = 131). Plasma concentrations of sST2, IL-33, soluble vascular endothelial growth factor receptor (sVEGFR)-1, soluble endoglin (sEng) and placental growth factor (PlGF) were determined by enzyme linked immune sorbent assay. Area under the receiver operating characteristic curve (AUC) for the identification of preeclampsia was examined for each analyte.

RESULTS

(1) Patients with preeclampsia had a higher mean plasma concentrations of sST2 than those with an uncomplicated pregnancy (p < 0.0001), while no significant difference in the mean plasma concentration of IL-33 between the two groups was observed; (2) the magnitude of this difference was greater in early-onset, compared to late-onset disease, and in severe compared to mild preeclampsia; (3) sST2 plasma concentrations did not correlate with the results of uterine or umbilical artery Doppler velocimetry (p = 0.7 and p = 1, respectively) among women with preeclampsia; (4) sST2 correlated positively with plasma concentrations of sVEGFR1-1 and sEng (Spearman's Rho = 0.72 and 0.63; each p < 0.0001), and negatively with PlGF (Spearman's Rho = -0.56, p < 0.0001); and (5) while the AUC achieved by sST2 and angiogenic/anti-angiogenic factors in identifying women with preeclampsia at the time of diagnosis were non-significantly different prior to term (<37 weeks of gestation), thereafter the AUC achieved by sST2 was significantly less than that achieved by angiogenic/anti-angiogenic factors.

CONCLUSIONS

Preeclampsia is associated with increased maternal plasma concentrations of sST2. The findings that sST2 concentrations do not correlate with uterine or umbilical artery Doppler velocimetry in women with preeclampsia suggest that elevated maternal plasma sST2 concentrations in preeclampsia are not related to the increased impedance to flow in the utero-placental circulation. The performance of sST2 in identifying preeclampsia at the time of diagnosis prior to 37 weeks of gestation was comparable to that of angiogenic/anti-angiogenic factors. It remains to be elucidated if an elevation of maternal plasma sST2 concentrations in pregnancy is specific to preeclampsia.

Maternal plasma concentrations of angiogenic/antiangiogenic factors in the third trimester of pregnancy to identify the patient at risk for stillbirth at or near term and severe late preeclampsia

OBJECTIVE

To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30-34 weeks of gestation can identify patients at risk for stillbirth, late preeclampsia, and delivery of small-for-gestational-age (SGA) neonates.

STUDY DESIGN

A prospective cohort study included 1269 singleton pregnant women from whom blood samples were obtained at 30-34 weeks of gestation and who delivered at >34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of late (>34 weeks of gestation) preeclampsia, severe late preeclampsia, stillbirth, and SGA was 3.2% (n = 40), 1.8% (n = 23), 0.4% (n = 5), and 8.5% (n = 108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late preeclampsia (adjusted odds ratio, 16); the addition of PlGF/sEng to clinical risk factors increased the area under the receiver-operating characteristic curve from 0.76 to 0.88 (P = .03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20-25 weeks of gestation for the prediction of severe late preeclampsia (comparison of areas under the receiver-operating characteristic curve; each P ≤ .02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false-positive rate of 15% for the identification of severe late preeclampsia. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30-34 weeks of gestation had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80%; specificity 93%) were observed in a separate case-control study.

CONCLUSION

Risk assessment for stillbirth and severe late preeclampsia in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and antiangiogenic factors at 30-34 weeks of gestation.

Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

OBJECTIVES

The current study sought to identify macroscopic placental changes associated with clinical conditions in women with or without diabetes and their newborns.

METHODS

The study population consisted of 62 pregnant women clinically diagnosed with diabetes and 62 healthy women (control group).

RESULTS

Among the subjects with diabetes, 43 women (69.3%) were diagnosed with gestational diabetes mellitus, 15 had diabetes mellitus I (24.2%), and four had diabetes mellitus II (6.5%). The mean age of the women studied was 28.5 ± 5.71 years, and the mean gestational age of the diabetic women was 38.51 weeks. Of the 62 placentas from diabetic pregnancies, 49 (79%) maternal surfaces and 59 (95.2%) fetal surfaces showed abnormalities, including calcium and fibrin deposits, placental infarction, hematoma, and fibrosis. A statistical association was found between newborn gender and fetal and maternal placental changes (p = 0.002). The mean weight of the newborns studied was 3,287 ± 563 g for women with diabetes mellitus, 3,205 ± 544 g for those with gestational diabetes mellitus, 3,563 ± 696 g for those with diabetes mellitus II, and 3,095 ± 451 g for those with diabetes mellitus I.

CONCLUSIONS

Infarction, hematoma, calcification, and fibrin were found on the maternal and fetal placental surfaces in women with diabetes. Women with gestational diabetes and post-term infants had more calcium deposits on the maternal placental surface as compared to those with type I and type II diabetes.

Intrauterine growth retardation and nonalcoholic Fatty liver disease in children

Intrauterine growth retardation (IUGR), the most important cause of perinatal mortality and morbidity, is defined as a foetal growth less than normal for the population, often used as synonym of small for gestational age (SGA). Studies demonstrated the relationships between metabolic syndrome (MS) and birthweight. This study suggested that, in children, adolescents, and adults born SGA, insulin resistance could lead to other metabolic disorders: type 2 diabetes (DM2), dyslipidemia, and nonalcoholic fatty liver disease (NAFLD). NAFLD may evolve to nonalcoholic steatohepatitis (NASH), and it is related to the development of MS. Lifestyle intervention, physical activity, and weight reduction represent the mainstay of NAFLD therapy. In particular, a catch-up growth reduction could decrease the risk to develop MS and NAFLD. In this paper, we outline clinical and experimental evidences of the association between IUGR, metabolic syndrome, insulin resistance, and NAFLD and discuss on a possible management to avoid the risk of MS in adulthood.

High-saturated-fat diet induces gestational diabetes and placental vasculopathy in C57BL/6 mice

Gestational diabetes mellitus (GDM) is a commonly encountered disorder of mid to late pregnancy that is characterized by hyperglycemia, hyperinsulinemia, and impaired glucose tolerance. Gestational diabetes mellitus is thought to be multifactorial in origin and derives from both genetic and environmental factors. However, the mechanisms underlying GDM are incompletely understood; and current GDM animal models do not appear to closely mimic the clinical situation in humans. The present study used environmental exposure to high-saturated-fat diet (HFD) in an effort to develop a GDM mouse model that closely simulates metabolic abnormalities seen in human GDM. This model was then used to determine the contributions of HFD-induced placental oxidative stress (OS) and vascular dysregulation, which are observed in GDM patients and are believed to contribute to the pathogenesis of the disease. Pathologic manifestations of the disease were quantified by evaluating the extent of placental lipid peroxidation and by determining protective effects of dietary antioxidant quercetin supplementation to reduce HFD-associated placental OS. In this study, female C57BL/6 mice were fed HFD for 1 month before conception and throughout gestation to mimic chronic maternal fast food consumption. Maternal body weight increased from gestation day (GD) 0 to GD19 by 41% with HFD, as compared with 23% in control dams; HFD dams also developed insulin resistance (66% increase in plasma insulin and 27% increase in plasma glucose levels by GD10) as compared with control dams. Placentas from HFD GD19 dams demonstrated loss of trophoblasts and OS-mediated labyrinthine endothelial cellular damage, the latter of which was prevented with quercetin supplementation. Our findings suggest that prenatal HFD alters glucose metabolism and elevates placental OS, which are believed to collectively relate to improper formation of the conceptus and impaired birth outcome.

Ethanol-induced inhibition of fetal hypothalamic-pituitary-adrenal axis due to prenatal overexposure to maternal glucocorticoid in mice

Prenatal ethanol exposure has been well documented to be one of the etiological factors responsible for intrauterine growth retardation (IUGR). Previous studies have shown that chronic ethanol exposure during pregnancy elevated the basic level of corticosterone in fetus. However, the potential mechanisms behind them are still unclear. The aim of the present study was to investigate the effects of prenatal ethanol exposure on maternal and fetal hypothalamic-pituitary-adrenal (HPA) axis as well as placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2), and to clarify the mechanism of ethanol-induced IUGR. Pregnant mice were intragastricly administrated with ethanol at a dose of 6.4 g kg(-1) d(-1) from day 11 to 17 of gestation and parameters representing fetal growth and development were recorded either. The level of corticosterone in maternal serum was determined by ELISA kit. The mRNA expressions of steroidogenic acute regulatory protein (StAR) and cytochrome P450 cholesterol side chain cleavage (P450scc) both in maternal and fetal adrenal, and placental 11β-HSD-2 were detected by real-time quantitative PCR, respectively. The results showed that fetal body weight significantly decreased, and the incidence of IUGR was obviously increased after prenatal ethanol exposure. Maternal serum corticosterone level was elevated, and the expressions of StAR and P450scc were increased in maternal adrenal while decreased in fetal adrenal. The expression of placental 11β-HSD-2 was significantly reduced. These results suggest that prenatal ethanol exposure induces an inhibition of fetal HPA axis activity and IUGR occurs. The mechanism may be associated with ethanol-induced maternal HPA axis activation and high glucocorticoid condition, which impair the placental barrier, and lead to an overexposure of elevated maternal glucocorticoid to fetus, and eventually result in the inhibition of the fetal HPA axis.

Mitochondrial manganese superoxide dismutase mRNA expression in human chorioamniotic membranes and its association with labor, inflammation, and infection

OBJECTIVE

Human parturition is characterized by the activation of genes involved in acute inflammatory responses in the fetal membranes. Manganese superoxide dismutase (Mn SOD) is a mitochondrial enzyme that scavenges reactive oxygen species (ROS). Mn SOD is up-regulated in sites of inflammation and has an important role in the down-regulation of acute inflammatory processes. Therefore, the aim of this study was to determine the differences in Mn SOD mRNA expression in the fetal membranes in patients with term and preterm labor (PTL) as well as in acute chorioamnionitis.

STUDY DESIGN

Fetal membranes were obtained from patients in the following groups: (1) term not in labor (n = 29); (2) term in labor (n = 29); (3) spontaneous PTL with intact mebranes (n = 16); (4) PTL with histological chorioamnionitis (n = 12); (5) preterm prelabor rupture of the membranes (PPROM; n = 17); and (6) PPROM with histological chorioamnionitis (n = 21). Mn SOD mRNA expression in the membranes was determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

(1) Mn SOD mRNA expression was higher in the fetal membranes of patients at term in labor than those not in labor (2.4-fold; p = 0.02); (2) the amount of Mn SOD mRNA in the fetal membranes was higher in PTL than in term labor or in PPROM (7.2-fold, p = 0.03; 3.2-fold, p = 0.03, respectively); (3) Mn SOD mRNA expression was higher when histological chorioamnionitis was present both among patients with PPROM (3.8-fold, p = 0.02) and with PTL (5.4-fold, p = 0.02) than in patients with these conditions without histological chorioamnionitis; (4) expression of Mn SOD mRNA was higher in PTL with chorioamnionitis than in PPROM with chorioamnionitis (4.3-fold, p = 0.03).

CONCLUSION

The increase in Mn SOD mRNA expression by fetal membranes in term labor and in histological chorioamnionitis in PTL and PPROM suggests that the fetus deploys anti-oxidant mechanisms to constrain the inflammatory processes in the chorioamniotic membranes.

Maternal exposure to environmental tobacco smoke, GSTM1/T1 polymorphisms and oxidative stress

Environmental tobacco smoking (ETS) is known to be associated with adverse pregnancy outcomes. The purpose of this study was to investigate the relationship between maternal exposure to ETS and oxidative stress for neonates, as well as the effect of maternal genetic polymorphisms, glutathione-S-transferase M1 (GSTM1) and GSTT1, on this relationship. We used the radioimmunoassay to measure the urinary concentration of cotinine in 266 pregnant women who denied smoking cigarettes during pregnancy and in their singleton babies. In addition, the urinary concentration of malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OH-dG) were assessed using high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. We also extracted DNA from whole blood obtained from the mothers and then conducted polymerase chain reaction on the samples to determine the GSTM1 and GSTT1 genotypes. The maternal cotinine concentration was found to be significantly associated with the fetal cotinine concentration, particularly for mothers whose urine cotinine concentrations were above 120 microg/gcr (p<0.01). The fetal urine cotinine concentration was also found to be significantly associated with the fetal urine MDA concentration (p<0.01). When the null type maternal GSTM1 or the wild type GSTT1 was present, the maternal oxidative stress level increased significantly as the maternal continine concentration increased (MDA: p<0.01; 8-OH-dG: p<0.01). No significant relationships were found between maternal cotinine and fetal oxidative stress markers, however, the fetal MDA levels increased significantly as fetal cotinine levels increased. These results suggest that the maternal exposure to ETS affects the fetal urine cotinine concentration and induces production of maternal oxidative stress. In addition, maternal genetic polymorphisms of GSTM1 and GSTT1 may modify the oxidative stress by maternal exposure to ETS.

Overexpression of thioredoxin-1 reduces oxidative stress in the placenta of transgenic mice and promotes fetal growth via glucose metabolism

Oxidative stress occurs where there is an imbalance between the production and scavenging of free radicals. Pregnancy per se is a state of oxidative stress due to the increased metabolic activity of placental mitochondria and reduced scavenging ability of antioxidant systems. Overproduction of reactive oxygen species may be associated with impaired fetal growth. However, the physiological influence of antioxidant systems on fetal growth is not well understood. In this study we assessed the effects of antioxidant systems on fetal growth using human thioredoxin (hTRX)-1 overexpressing transgenic (Tg) mice. Tg or C57BL/6 [wild-type (WT)] male mice were mated with WT female mice, and dams were killed to obtain the fetuses and placentas on gestational d 15. Tg fetuses were significantly heavier than WT fetuses, whereas placental weight did not differ significantly between the two groups. Immunohistochemically, hTRX-1 was localized to the nuclei of labyrinthine trophoblasts in Tg mice. In addition, placental expression of 8-hydroxy-2'-deoxyguanosine, which reflects DNA damage caused by oxidative stress, was reduced in Tg mice compared with WT mice. Placental expression of glucose transporter-1 mRNA and protein was significantly higher in Tg mice than WT mice, whereas no significant differences were observed for glucose transporter-3, IGF, and IGF-binding protein mRNA expression. These results suggest that placental and/or systemic antioxidant systems can influence fetal growth. In particular, increased hTRX-1 activity and the resulting modified placental redox state may play an important role in fetal growth by increasing the availability of glucose.

Causes of Intrauterine Growth Restriction and the Postnatal Development of the Metabolic Syndrome

The term intrauterine growth restriction (IUGR) is assigned to newborns with a birth weight and/or birth length below the 10th percentile for their gestational age and whose abdominal circumference is below the 2.5th percentile with pathologic restriction of fetal growth. IUGR is usually due to maternal, fetal, or placental factors. However, many IUGR cases have unknown underlying cause. Recent studies focus on new factors that can influence fetal development and birth outcome like the timing and the type of fetal nutrition, maternal psychosocial stress and personality variables, 11beta-hydroxysteroid dehydrogenase type 2 placental activity, the activity of the neuroendocrine system that mediates the effects of psychosocial stress, and the role of proinflammatory cytokines and of oxidative stress. Data have shown that IUGR is associated with a late life increased prevalence of metabolic syndrome, a condition associating obesity with hypertension, type 2 diabetes mellitus (DM2), and cardiovascular disease. Recent data demonstrated that the diabetes-associated mortality appears to be disproportionately concentrated among individuals of abnormal birth weight.

Peroxynitrite treatment in vitro disables catalytic activity of recombinant p38 MAPK

Protein tyrosine nitration is a post-translational modification occurring under conditions of oxidative stress in a number of diseases. The causative agent of tyrosine nitration is the potent prooxidant peroxynitrite that results from the interaction of nitric oxide and superoxide. We have previously demonstrated existence of nitrotyrosine in placenta from pregnancies complicated by preeclampsia, which suggested the possibility of the existence of nitrated proteins. Nitration of various proteins has been demonstrated to more commonly result in loss of protein function. Potential nitration of p38 MAPK, a critical signaling molecule has been suggested and also tentatively identified in certain in vivo systems. In this study we demonstrate for the first time nitration of recombinant p38 MAPK in vitro and an associated loss of its catalytic activity. LC-MS data identified tyrosine residues Y132, Y245 and Y258 to be nitrated. Nitration of these specific residues was deduced from the 45.0-Da change in mass that these residues exhibited that was consistent with the loss of a proton and addition of the nitro group.

Maternal exposure to low levels of ambient air pollution and preterm birth in Brisbane, Australia

BACKGROUND

[corrected] There is evidence that maternal exposure to ambient air pollution during pregnancy is associated with adverse birth outcomes.

OBJECTIVE

To assess preterm birth (PTB) in relation to maternal exposure to ambient air pollution.

DESIGN

Retrospective cohort.

SETTING

Brisbane, Australia.

POPULATION

A total of 28,200 singleton live births for the period of 1 July 2000 to 30 June 2003.

METHODS

Average maternal exposure estimates for ambient particulate matter (PM(10) and bsp), ozone (O(3)) and nitrogen dioxide were calculated over the first 3 months after last menstrual period (LMP) and the last 3 months prior to birth (individually and combined as trimesters).

MAIN OUTCOME MEASURES

PTB was defined as gestation <37 weeks and odds ratios (OR) were calculated for PTB per interquartile range increase in the maternal exposure estimate for each pollutant. Various covariates were controlled for, including season of birth.

RESULTS

Exposure to PM(10) and O(3) during trimester one was associated with an increased risk of PTB (OR = 1.15, 95% CI 1.06-1.25 and OR = 1.26, 95% CI 1.10-1.45, respectively). The PM(10) exposure effect associated with trimester one was strongly related to exposure during the first month post-LMP (PM(10), month one; OR = 1.19, 95% CI 1.13-1.26).

CONCLUSION

These results suggest that maternal exposure to low levels of ambient air pollution is associated with PTB.

Endogenous anti-oxidants in pregnancy and preeclampsia

Oxidative stress has been implicated in a wide variety of diseases and degenerative states including cancer, rheumatoid arthritis, cardiovascular disease and ageing. There is now considerable evidence to suggest that pregnancy leads to the generation of an increased oxidative burden, but whether this overwhelms the anti-oxidant capacity within the placenta and/or the peripheral circulation remains a point of conjecture. There is little doubt that oxidative stress is a significant contributor in the pathogenesis of preeclampsia. The use of exogenous anti-oxidants such as vitamins C and E in the prevention of preeclampsia is the subject of several large clinical trials currently being conducted in many countries around the world. The results of these studies are eagerly awaited, but what of the endogenous anti-oxidant systems that have evolved to combat the oxidative burden associated with living in an aerobic environment? This review will focus on several important anti-oxidant enzyme systems, their role in pregnancy and the evidence to suggest that endogenous anti-oxidants are important in the development of complications of pregnancy such as preeclampsia.

Villous histomorphometry and placental bed biopsy investigation in Type I diabetic pregnancies

Insulin-dependent diabetes mellitus (Type I) is associated with disregulation of the glucose and oxygen metabolic pathways during pregnancy, both of which affect placental villous development. Term complete placentas and placental bed biopsies, between 37 and 40 weeks, from 12 singleton pregnancies complicated by Type I diabetes were collected following delivery by elective Caesarean section. The controls consisted of 10 term placentas from uncomplicated pregnancies delivered by elective Caesarean section. Villous morphology was investigated using unbiased histomorphometric techniques, in relation to the degree of transformation of the spiral arteries and the presence of fetal macrosomia. A significant increase in fetal and placental weights, placental volume, volumes of the intervillous space and the trophoblast was found in the diabetic group compared to the controls. A significant reduction in the villous membrane specific diffusing capacity was observed between the diabetic and control groups (1.32 vs 1.72 cm3 min(-1)mmHg(-1)kg(-1), P=0.032). A significant increase in the volume of the intermediate and terminal villi, the surface area of the villi and of the fetal capillaries, and the harmonic thickness of the villous membrane was found in the macrosomic subgroup compared to the controls. There were no differences between the hypertensive subgroup with histological evidence of partial transformation of the spiral arteries and the controls. These data indicate that placental development in insulin-dependent diabetic pregnancies is affected differentially when pregnancies complicated by fetal macrosomia are separated from those complicated by maternal hypertensive disorders with partial transformation of the spiral arteries. The reduction in the specific diffusing capacity of the villous membrane may contribute to the fetal hypoxia and increased fetal and neonatal morbidity associated with diabetes.

Accumulation of advanced glycation end products in women with preeclampsia: possible involvement of placental oxidative and nitrative stress

Advanced glycation end products (AGEs) are known to cause oxidative damage in various cells by binding with its receptor, RAGE. We measured the serum level of AGEs and examined the AGEs, RAGE, and the other biomarkers of oxidative stress in the placentas from preeclamptic women. Competitive ELISA was carried out to measure the AGEs in serum. Western blotting was performed to analyze AGEs and RAGE in the placenta. Immunohistochemical analyses were performed to examine the localization of AGEs, RAGE, and other biomarkers of oxidative stress in the placenta. The mean level of serum AGEs in preeclamptic women was significantly higher than that in healthy non-pregnant women or healthy pregnant women. Western blotting revealed that the level of AGEs or RAGE in preeclamptic placenta was significantly higher than that in normal placenta. Immunohistochemical analyses showed that levels of nitrotyrosine and nitroguanosine, which are formed by reactive nitrogen species, in preeclamptic placenta were higher than those in normal placenta. Accumulation of 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine indicated enhanced oxidative modifications of lipids and DNA in preeclamptic placenta. The AGE-RAGE system, which is upregulated in preeclampsia, is likely to be involved in the oxidative stress of preeclampsia.

Functional proteomics of neurokinin B in the placenta indicates a novel role in regulating cytotrophoblast antioxidant defences

Neurokinin B (NKB) has recently been demonstrated to be secreted from the placenta in abnormally high amounts in preeclampsia (PE) and to cause hypertension in rats, suggesting it may be a mediator of some pathophysiological features of PE. It is also known that NKB receptors exist in the placenta. To determine the effect of high levels of NKB on the placenta, we have performed proteomics on five separate preparations of cultured purified human term cytotrophoblast cells. The results showed a statistically significant decrease in 20 proteins, of which five were unknown proteins. Proteins important in antioxidant defenses that decreased were thioredoxin, cyclophilin A, cytokeratin 1, and peroxiredoxin 5. Two proteins that inhibit intravascular anticoagulation, cytokeratin 1 and annexin 11 were also decreased. Pathways involving pro-inflammatory cytokine activation of NF-kappa B are opposed by Raf kinase inhibitor protein, which was also decreased. Cofilin 1, a protein involved in defense against bacteria, was also decreased. Among other proteins that were suppressed by NKB were proteasome proteins, desmoplakin, and calgizzarin. Western blots confirmed the decrease in cytokeratin 1 and cyclophilin A protein after NKB exposure. In PE, there is reduced antioxidant activity and increased intravascular coagulation. The findings that high levels of NKB, similar to those observed in PE, can impair these two classes of activity support the hypothesis that high NKB levels may contribute to the pathogenesis of PE.

Levels of oxidative stress and redox-related molecules in the placenta in preeclampsia and fetal growth restriction

Recent evidence suggests that oxidative stress is involved in the pathophysiology of preeclampsia. Using immunohistochemistry and Western blotting, we investigated the oxidative stress- and redox-related molecules, such as 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), thioredoxin (TRX) and redox factor-1 (ref-1) in the placenta in preeclampsia, intrauterine growth restriction (IUGR), preeclampsia + IUGR and in normal pregnancy. Using immunohistochemistry, the level of 8-OHdG was significantly higher in IUGR ( P=0.012) or preeclampsia + IUGR (P=0.0021) than in normal pregnancy, while TRX expression was significantly higher in preeclampsia (P=0.045), and ref-1 expression was significantly higher in preeclampsia (P=0.017), IUGR (P=0.016) and preeclampsia + IUGR (P=0.0038) than in normal pregnancy. The levels of 4-HNE did not differ significantly between either preeclampsia or IUGR and normal pregnancy. A significant positive correlation was observed between TRX and ref-1 expressions in both normal (rho=0.52) and complicated (rho=0.43) pregnancies. Using Western blotting, ref-1 expression tended to be higher in complicated pregnancies than in normal pregnancy (P=0.09). These results suggest that oxidative DNA damage is increased in IUGR and that redox function is enhanced in both preeclampsia and IUGR compared with normal pregnancy.

The pharmacology of nitric oxide in the peripheral nervous system of blood vessels

Unanticipated, novel hypothesis on nitric oxide (NO) radical, an inorganic, labile, gaseous molecule, as a neurotransmitter first appeared in late 1989 and into the early 1990s, and solid evidences supporting this idea have been accumulated during the last decade of the 20th century. The discovery of nitrergic innervation of vascular smooth muscle has led to a new understanding of the neurogenic control of vascular function. Physiological roles of the nitrergic nerve in vascular smooth muscle include the dominant vasodilator control of cerebral and ocular arteries, the reciprocal regulation with the adrenergic vasoconstrictor nerve in other arteries and veins, and in the initiation and maintenance of penile erection in association with smooth muscle relaxation of the corpus cavernosum. The discovery of autonomic efferent nerves in which NO plays key roles as a neurotransmitter in blood vessels, the physiological roles of this nerve in the control of smooth muscle tone of the artery, vein, and corpus cavernosum, and pharmacological and pathological implications of neurogenic NO have been reviewed. This nerve is a postganglionic parasympathetic nerve. Mechanical responses to stimulation of the nerve, mainly mediated by NO, clearly differ from those to cholinergic nerve stimulation. The naming "nitrergic or nitroxidergic" is therefore proposed to avoid confusion of the term "cholinergic nerve", from which acetylcholine is released as a major neurotransmitter. By establishing functional roles of nitrergic, cholinergic, adrenergic, and other autonomic efferent nerves in the regulation of vascular tone and the interactions of these nerves in vivo, especially in humans, progress in the understanding of cardiovascular dysfunctions and the development of pharmacotherapeutic strategies would be expected in the future.

Maternal diabetes in vivo and high glucose in vitro diminish GAPDH activity in rat embryos

The aim of the present study was to investigate whether diabetic embryopathy may be associated with the inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) resulting from an excess of reactive oxygen species (ROS) in the embryo. Recent demonstrations of enhanced ROS production in mitochondria of bovine aortic endothelial cells exposed to high glucose have supported the idea that the pathogenesis of diabetic complications may involve ROS-induced GAPDH inhibition. We investigated whether a teratogenic diabetic environment also inhibits embryonic GAPDH activity and alters GAPDH gene expression and whether antioxidants diminish such GAPDH inhibition. In addition, we determined whether the inhibition of GAPDH with iodoacetate induces dysmorphogenesis, analogous to that caused by high glucose concentration, and whether antioxidants modulated the putative teratogenic effect of such direct GAPDH inhibition. We found that embryos from diabetic rats and embryos cultured in high glucose concentrations showed decreased activity of GAPDH (by 40-60%) and severe dysmorphogenesis on gestational days 10.5 and 11.5. GAPDH mRNA was decreased in embryos of diabetic rats compared to control embryos. Supplementing the high-glucose culture with the antioxidant N-acetylcysteine (NAC) increased GAPDH activity and diminished embryonic dysmorphogenesis. Embryos cultured with iodoacetate showed both decreased GAPDH activity and dysmorphogenesis; supplementing the culture with NAC increased both parameters toward normal values. In conclusion, dysmorphogenesis caused by maternal diabetes is correlated with ROS-induced inhibition of GAPDH in embryos, which could indicate that inhibition of GAPDH plays a causal role in diabetic embryopathy.

Nitrotyrosine immunostaining correlates with increased extracellular matrix: evidence of postplacental hypoxia

Nitrotyrosine residues (NT), an index of oxidative stress arising from peroxynitrite formation and action, are found in placental vasculature of pregnancies complicated by pre-eclampsia (PE) or pregestational insulin-dependent diabetes mellitus (IDDM). This study correlates conventional placental pathology with NT immunostaining in 20 cases of perinatal mortality (13 stillbirths and seven cases of neonatal mortality) associated with PE, IDDM, amniotic fluid infection syndrome (AFIS), or from fetal/neonatal demise not related to these conditions (congenital anomalies) (n = five/group). Patients with PE have more decidual arteriolopathy and Tenney-Parker change, while patients with IDDM and ascending infection have more villous cytotrophoblastic hyperplasia. Archival paraffin-embedded placental sections were immunostained for NT for correlation with clinical features and H&E histological findings. The intensity of immunostaining for NT varied from absent (n = 7) to 1+ (n = 5) or 2+ (n = 8). All eight placentae with 2+ staining showed increased villous extracellular matrix (ECM), compared to none of five with 1+ staining and two of seven with no staining (chi2 = 14.3, P = 0.001). There was no statistically significant difference in the percentage of stem villi with luminal vascular abnormalities (5.7 vs 10 vs 35.7 per cent, F = 2.3, P = 0.1). Our data show that increased production of reactive oxygen species by placental tissue may be associated with increased extracellular matrix, itself produced by fibroblasts under the influence of oxygen. NT immunostaining may therefore help differentiate those cases of perinatal morbidity/mortality associated with post-placental hypoxia provided that the secondary impact of intrauterine fetal death can be excluded by future studies.