Placental oxidative DNA damage and its repair in preeclamptic women with fetal growth restriction

Oxidative stress biomarkers for fetal growth restriction in umbilical cord blood: A scoping review

Fetal growth restriction and underlying placental insufficiency are associated with increased oxidative stress. Current diagnostics fail to identify all growth restricted fetuses and newborns, due to focus on small size. This scoping review aims to summarize the available evidence on usefulness of cord blood oxidative stress biomarkers for identification of growth restricted newborns in need of monitoring and support because of associated health risks. MEDLINE and EMBASE were searched from inception to May 2024. Studies were included if oxidative stress biomarkers were measured in cord blood collected immediately after delivery in newborns suspected to be growth restricted. Biomarkers were categorized based on the origin and/or biological function and their interrelationships. Oxidative stress was determined for each individual biomarker and category. Literature search identified 78 studies on 39 different biomarkers, with a total of 2707 newborns with suspected growth restriction, and 4568 controls. Total oxidant/antioxidant status, catalase, glutathione, ischemia-modified albumin, and nucleated red blood cells were most consistently associated with suspected growth restriction. Reactive oxygen species/reactive nitrogen species, factors in their production, antioxidant enzymes, non-enzymatic antioxidants, and products of oxidative stress were not consistently associated. This review collates the evidence of associations between cord blood oxidative stress biomarkers and growth restriction. Total oxidant/antioxidant status, catalase, glutathione, ischemia-modified albumin, and nucleated red blood cells could potentially be candidates for developing a cord blood diagnostic tool for future clinical use.

Impact of cash transfers on the association between prenatal exposures to high temperatures and low birthweight: Retrospective analysis from the LEAP 1000 study

OBJECTIVE

To explore the associations between prenatal temperature exposures and low birthweight (LBW) and modification by cash transfer (CT) receipt.

DESIGN

Retrospective cohort study.

SETTING

Five rural districts in Northern Ghana.

POPULATION OR SAMPLE

A total of 3016 infants born to women interviewed as part of the Livelihood Empowerment Against Poverty (LEAP 1000) impact evaluation between 2015 and 2017.

METHODS

Birthweight was collected using household surveys administered to LEAP 1000 eligible women. We used a UNICEF-developed multiple imputation approach to address missingness of birthweight and applied an empirical heaping correction to the multiply imputed birthweight data. Survey data were linked to the European Centre for Medium-Range Weather Forecasts Reanalysis 5-hourly temperature averaged to weeks for 2011-2017 using community centroids. Using distributed-lag nonlinear models, we explored the lag-specific associations between weekly average temperatures greater than 30°C and LBW, and stratified by LEAP 1000 treatment.

MAIN OUTCOME MEASURES

Low birthweight (<2.5 kg).

RESULTS

Twelve percent (n = 365) of infants were LBW; the mean ± SD birthweight was 3.02 ± 0.37 kg. Overall, increasing temperatures were associated with increased odds of LBW, with the greatest odds observed in the 3 weeks before birth (odds ratio 1.005-1.025). These positive associations were even larger among comparison infants and null among treatment infants.

CONCLUSIONS

Our study found increased odds of LBW with high weekly average temperatures throughout pregnancy and the preconception period and demonstrate mitigated effects by the LEAP 1000 CT program. More evidence on the potential of CTs to serve as adaptation interventions in low- and middle-income countries is needed to protect pregnant persons and their infants from the impacts of climate change.

Optimizing the Comet Assay-Based In Vitro DNA Repair Assay for Placental Tissue: A Pilot Study with Pre-Eclamptic Patients

The comet assay-based in vitro DNA repair assay has become a common tool for quantifying base excision repair (BER) activity in human lymphocytes or cultured cells. Here, we optimized the protocol for studying BER in human placental tissue because the placenta is a non-invasive tissue for biomonitoring of early-life exposures, and it can be used to investigate molecular mechanisms associated with prenatal disorders. The optimal protein concentration of placental protein extracts for optimal damage recognition and incision was 2 mg protein/mL. The addition of aphidicolin did not lead to reduced non-specific incisions and was, therefore, not included in the optimized protocol. The interval between sample collection and analysis did not affect BER activity up to 70 min. Finally, this optimized protocol was tested on pre-eclamptic (PE) placental tissues (n = 11) and significantly lower BER activity in PE placentas compared to controls (n = 9) was observed. This was paralleled by a significant reduction in the expression of BER-related genes and increased DNA oxidation in PE placentas. Our study indicates that BER activity can be determined in placentas, and lower activity is present in PE compared with healthy. These findings should be followed up in prospective clinical investigations to examine BER's role in the advancement of PE.

Exploring the Role of Mediterranean and Westernized Diets and Their Main Nutrients in the Modulation of Oxidative Stress in the Placenta: A Narrative Review

Oxidative stress is a major cellular event that occurs in the placenta, fulfilling critical physiological roles in non-pathological pregnancies. However, exacerbated oxidative stress is a pivotal feature of different obstetric complications, like pre-eclampsia, fetal growth restriction, and other diseases. Compelling evidence supports the relevant role of diet during pregnancy, with pleiotropic consequences for maternal well-being. The present review aims to examine the complex background between oxidative stress and placental development and function in physiological conditions, also intending to understand the relationship between different dietary patterns and the human placenta, particularly how this could influence oxidative stress processes. The effects of Westernized diets (WDs) and high-fat diets (HFDs) rich in ultra-processed foods and different additives are compared with healthy patterns such as a Mediterranean diet (MedDiet) abundant in omega 3 polyunsaturated fatty acids, monounsaturated fatty acids, polyphenols, dietary fiber, and vitamins. Although multiple studies have focused on the role of specific nutrients, mostly in animal models and in vitro, further observational and intervention studies focusing on the placental structure and function in women with different dietary patterns should be conducted to understand the precise influence of diet on this organ.

Hypoxia-inducible factor 1 signaling drives placental aging and can provoke preterm labor

Most cases of preterm labor have unknown cause, and the burden of preterm birth is immense. Placental aging has been proposed to promote labor onset, but specific mechanisms remain elusive. We report findings stemming from unbiased transcriptomic analysis of mouse placenta, which revealed that hypoxia-inducible factor 1 (HIF-1) stabilization is a hallmark of advanced gestational timepoints, accompanied by mitochondrial dysregulation and cellular senescence; we detected similar effects in aging human placenta. In parallel in primary mouse trophoblasts and human choriocarcinoma cells, we modeled HIF-1 induction and demonstrated resultant mitochondrial dysfunction and cellular senescence. Transcriptomic analysis revealed that HIF-1 stabilization recapitulated gene signatures observed in aged placenta. Further, conditioned media from trophoblasts following HIF-1 induction promoted contractility in immortalized uterine myocytes, suggesting a mechanism by which the aging placenta may drive the transition from uterine quiescence to contractility at the onset of labor. Finally, pharmacological induction of HIF-1 via intraperitoneal administration of dimethyloxalyl glycine (DMOG) to pregnant mice caused preterm labor. These results provide clear evidence for placental aging in normal pregnancy, and demonstrate how HIF-1 signaling in late gestation may be a causal determinant of the mitochondrial dysfunction and senescence observed within the trophoblast as well as a trigger for uterine contraction.

Relationship between birth weight and ambient temperature during pregnancy in a cross-sectional study of the residents of Suzhou, China

Objective

The association between birth weight and ambient temperature during pregnancy remains inconclusive, and data from Chinese populations are scarce. We conducted a cross-sectional study to investigate the association between birth weight and ambient temperature during pregnancy among the residents of Suzhou Industrial Park, Suzhou, China.

Methods

Information regarding 10,903 infants born between January 2018 and December 2018 who were born at the hospitals in Suzhou Industrial Park, Jiangsu province was obtained via public birth records.

Results

This study found that the ambient temperature during the first trimester of pregnancy was negatively correlated with birth weight, suggesting that elevated temperature may be related to lower birth weight. However, the ambient temperatures during the second and third trimesters of pregnancy were positively correlated with birth weight. Moreover, when the ambient temperature was below 15°C during the second trimester of pregnancy, the birth weight increased with temperature. However, when the temperature was higher than 15°C, the birth weight decreased with temperature. The relationship between ambient temperature in the third trimester and birth weight presented an inverted "U" curve. When the ambient temperature was lower than 20°C, the birth weight increased with ambient temperature, but when the ambient temperature was higher than 20°C, the increase of ambient temperature showed no significant relationship with the increase of birth weight.

Conclusion

The ambient temperature was correlated with birth weight. The ambient temperature during the first trimester of pregnancy was negatively correlated with birth weight. The relationship between ambient temperature in the third trimester and birth weight presented an inverted "U" curve.

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.

Oxidative nucleic acid damage as a biomarker for preeclampsia

Recent studies have reported that nucleic acid oxidation is elevated in preeclampsia. Furthermore, it is known that products of nucleic acid oxidation are eventually removed through the urine. The aim of this study was to check whether urine can be used as a non-invasive specimen to analyse nucleic acid oxidation in preeclampsia. We carried out a case-control study by enrolling preeclamptic pregnant (n = 31) and normotensive pregnant (n = 31) women. Urine samples from the study participants were collected and the levels of oxidised guanine species (a common product of nucleic acid oxidation) were determined by ELISA method. The urinary levels of oxidised guanine species were significantly higher in the preeclamptic pregnant group compared to the normotensive pregnant group (p = 0.001). The results were also analysed after stratifying the preeclamptic group in terms of severity and gestational age of onset. A significant difference was observed in both mild (p = 0.005) and severe preeclampsia (p = 0.01). However, a significant difference was observed only in the late onset (p = 0.001) and not in the early onset preeclampsia (p = 0.56). The results of this study show that oxidised guanine level is elevated in the urine of preeclamptic pregnant women. IMPACT STATEMENTWhat is already known on this subject? Nucleic acid oxidation is elevated in preeclampsia. However, the utility of urine (a non-invasive specimen) to analyse nucleic acid oxidation is not known.What do the results of this study add? This study shows that the levels of oxidised guanine (a marker of nucleic acid oxidation) are elevated in the urine of preeclamptic women.What are the implications of these findings for clinical practice and/or further research? Urinary levels of oxidised guanine may be developed as a non-invasive biomarker for preeclampsia.

Dysregulated Autophagy Leads to Oxidative Stress and Aberrant Expression of ABC Transporters in Women with Early Miscarriage

Early miscarriage (EMC) is a devastating obstetrical complication. ATP-binding cassette (ABC) transporters mediate cholesterol transfer across the placenta and enhance cell survival by effluxing substrates from target cells in the presence of stressors. Recent evidence reports an intricate interplay between autophagy and ABC transporters. We hypothesized that dysregulated autophagy and oxidative stress (OS) in the placenta leads to abnormal expression of membrane transporters contributing to poor pregnancy survival in EMC. We determined mRNA and protein expression of autophagy genes (Beclin-1/Bcl-2/LC3I/LC3II/p62) and ABC transporters (ABCA1/ABCG1/ABCG2) in placentae from EMC patients (n = 20), term controls (n = 19), first trimester (n = 6), and term controls (n = 5) controls. Oxidative/antioxidant status and biomarkers of oxidative damage were evaluated in maternal serum and placentae from EMC and healthy controls. In EMC, placental expression of LC3II/LC3I as well as of the key autophagy regulatory proteins Beclin-1 and Bcl-2 were reduced, whereas p62 was increased. Both in the serum and placentae of EMC patients, total OS was elevated reflected by increased oxidative damage markers (8-OHdG/malondialdehyde/carbonyl formation) accompanied by diminished levels of total antioxidant status, catalase, and total glutathione. Furthermore, we found reduced ABCG1 and increased ABCG2 expression. These findings suggest that a decreased autophagy status triggers Bcl-2-dependent OS leading to macromolecule damage in EMC placentae. The decreased expression of ABCG1 contributes to reduced cholesterol export to the growing fetus. Increasing ABCG2 expression could represent a protective feedback mechanism under inhibited autophagy conditions. In conclusion, dysregulated autophagy combined with increased oxidative toxicity and aberrant expression of placental ABC transporters affects materno-fetal health in EMC.

DNA damage analysis in newborns and their mothers related to pregnancy and delivery characteristics

INTRODUCTION

Increased DNA damage is associated with early events in carcinogenesis. The foetus may be more susceptible to effects of environment by transplacental exposure. We aimed to evaluate DNA damage in cells from umbilical cord (arteries and vein) and maternal blood from pregnant women.

METHODS

Fifty eight pregnant women and their offspring were included in this study. They were submitted to an interview to obtain information about personal history, clinical history, and lifestyle habits. Other Information was obtained from medical records. The samples were prepared for Single Cell Gel/Comet assay and Cytokinesis-block Micronucleus Cytome (CBMN-Cyt) assay.

RESULTS

Correlation between DNA damage frequency by Comet assay from newborns and their mothers was statistically significant and was significantly associated with nulliparity and more than 1 h of second stage of labour (umbilical vein and maternal blood). A positive MNi relationship was noticed for age (mother's blood) and inappropriate birth weight for gestational age (maternal blood). When multivariate statistical analyses were applied to measure the degree of association between variables that influenced DNA damage markers in the first evaluation, inadequate birth weight and pregnant weight gain were associated with MNi frequency in maternal and newborns blood, respectively.

DISCUSSION

Significant associations between DNA damage in newborns and pregnant women, and birth and pregnancy events suggest molecular evidence of transplacental genotoxic effects. However, a potentially increased risk of degenerative diseases, such as cancers, in this population should be carefully investigated by further prospective cohort studies.

Machine learning approaches to predict gestational age in normal and complicated pregnancies via urinary metabolomics analysis

The elucidation of dynamic metabolomic changes during gestation is particularly important for the development of methods to evaluate pregnancy status or achieve earlier detection of pregnancy-related complications. Some studies have constructed models to evaluate pregnancy status and predict gestational age using omics data from blood biospecimens; however, less invasive methods are desired. Here we propose a model to predict gestational age, using urinary metabolite information. In our prospective cohort study, we collected 2741 urine samples from 187 healthy pregnant women, 23 patients with hypertensive disorders of pregnancy, and 14 patients with spontaneous preterm birth. Using gas chromatography-tandem mass spectrometry, we identified 184 urinary metabolites that showed dynamic systematic changes in healthy pregnant women according to gestational age. A model to predict gestational age during normal pregnancy progression was constructed; the correlation coefficient between actual and predicted weeks of gestation was 0.86. The predicted gestational ages of cases with hypertensive disorders of pregnancy exhibited significant progression, compared with actual gestational ages. This is the first study to predict gestational age in normal and complicated pregnancies by using urinary metabolite information. Minimally invasive urinary metabolomics might facilitate changes in the prediction of gestational age in various clinical settings.

MiR-212-3p promotes proliferation and migration of trophoblast in fetal growth restriction by targeting placental growth factor

The purpose of this study was to evaluate the function and possible mechanism of miR-212-3p in fetal growth restriction (FGR) and to demonstrate the relationship between miR-212-3p and placental growth factor (PGF). First, we used qRT-PCR to detect the expression of miR-212-3p and PGF in placental tissues of normal delivery (HC group) and FGR, as well as in human trophoblast cell HTR-8/Svneo. The results revealed that miR-212-3p expression was significantly upregulated and PGF was significantly downregulated in placental tissue in the FGR group compared with the HC group. In addition, interference with miR-212-3p expression increased the proliferation, invasion, and migration of HTR-8/SVneo cells and decreased apoptosis of cells. Meanwhile, Western blot results showed that miR-212-3p expression downregulation promoted the phosphorylated protein expression of Phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT), which in turn activated the PI3K/AKT signaling pathway. And the results of dual luciferase reporter further showed that miR-212-3p could target PGF, and the expression of both was negatively correlated in FGR group tissues. In addition, downregulation of miR-212-3p expression reversed the inhibitory effect of PGF downregulation on HTR-8/SVneo cells. In conclusion, miR-212-3p can target and inhibit the PGF expression and regulate the PI3K/AKT signaling pathway to regulate trophoblast cell invasion, migration, proliferation and cell apoptosis. This provides a potential biomarker for the development of FGR.

Preeclampsia and Cardiovascular Risk for Offspring

There is growing evidence of long-term cardiovascular sequelae in children after in utero exposure to preeclampsia. Maternal hypertension and/or placental ischaemia during pregnancy increase the risk of hypertension, stroke, diabetes, and cardiovascular disease (CVD) in the offspring later in life. The mechanisms associated with CVD seem to be a combination of genetic, molecular, and environmental factors which can be defined as fetal and postnatal programming. The aim of this paper is to discuss the relationship between pregnancy complicated by preeclampsia and possibility of CVD in the offspring. Unfortunately, due to its multifactorial nature, a clear dependency mechanism between preeclampsia and CVD is difficult to establish.

Hypoxia and Mitochondrial Dysfunction in Pregnancy Complications

Hypoxia is a common and severe stress to an organism's homeostatic mechanisms, and hypoxia during gestation is associated with significantly increased incidence of maternal complications of preeclampsia, adversely impacting on the fetal development and subsequent risk for cardiovascular and metabolic disease. Human and animal studies have revealed a causative role of increased uterine vascular resistance and placental hypoxia in preeclampsia and fetal/intrauterine growth restriction (FGR/IUGR) associated with gestational hypoxia. Gestational hypoxia has a major effect on mitochondria of uteroplacental cells to overproduce reactive oxygen species (ROS), leading to oxidative stress. Excess mitochondrial ROS in turn cause uteroplacental dysfunction by damaging cellular macromolecules, which underlies the pathogenesis of preeclampsia and FGR. In this article, we review the current understanding of hypoxia-induced mitochondrial ROS and their role in placental dysfunction and the pathogenesis of pregnancy complications. In addition, therapeutic approaches selectively targeting mitochondrial ROS in the placental cells are discussed.

Effect of Selenium and Iodine on Oxidative Stress in the First Trimester Human Placenta Explants

Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p < 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p < 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.

Term birthweight and critical windows of prenatal exposure to average meteorological conditions and meteorological variability

BACKGROUND

Heat stress during pregnancy may limit fetal growth, with ramifications throughout the life course. However, critical exposure windows are unknown, and effects of meteorological variability have not been investigated.

OBJECTIVES

We aimed to identify sensitive windows for the associations of mean and variability of temperature and humidity with term birthweight.

METHODS

We analyzed data from two French mother-child cohorts, EDEN and PELAGIE (n = 4771), recruited in 2002-2006. Temperature exposure was assessed using a satellite-based model with daily 1-km² resolution, and relative humidity exposure data were obtained from Météo France monitors. Distributed lag models were constructed using weekly means and standard deviation (SD, to quantify variability) from the first 37 gestational weeks. Analyses were then stratified by sex. Results for each exposure were adjusted for the other exposures, gestational age at birth, season and year of conception, cohort and recruitment center, and individual confounders.

RESULTS

There was no evidence of association between term birthweight and mean temperature. We identified a critical window in weeks 6-20 for temperature variability (cumulative change in term birthweight of -54.2 g [95% CI: -102, -6] for a 1 °C increase in SD of temperature for each week in that window). Upon stratification by sex of the infant, the relationship remained for boys (weeks 1-21, cumulative change: -125 g [95% CI: -228, -21]). For mean humidity, there was a critical window in weeks 26-37, with a cumulative change of -28 g (95% CI: -49, -7) associated with a 5% increase in humidity for each week. The critical window was longer and had a stronger association in boys (weeks 29-37; -37 g, 95% CI: -63, -11) than girls (week 14; -1.8 g, 95% CI: -3.6, -0.1).

DISCUSSION

Weekly temperature variability and mean humidity during critical exposure windows were associated with decreased term birthweight, especially in boys.

Mechanisms linking exposure to preeclampsia in utero and the risk for cardiovascular disease

Preeclampsia (PE) is now recognised as a cardiovascular risk factor for women. Emerging evidence suggests that children exposed to PE in utero may also be at increased risk of cardiovascular disease (CVD) in later life. Individuals exposed to PE in utero have higher systolic and diastolic blood pressure and higher body mass index (BMI) compared to those not exposed to PE in utero. The aim of this review is to discuss the potential mechanisms driving the relationship between PE and offspring CVD. Exposure to an adverse intrauterine environment as a consequence of the pathophysiological changes that occur during a pregnancy complicated by PE is proposed as one mechanism that programs the fetus for future CVD risk. Consistent with this hypothesis, animal models of PE where progeny have been studied demonstrate causality for programming of offspring cardiovascular health by the preeclamptic environment. Shared alleles between mother and offspring, and shared lifestyle factors between mother and offspring provide alternate pathways explaining associations between PE and offspring CVD risk. In addition, adverse lifestyle habits can also act as second hits for those programmed for increased CVD risk. PE and CVD are both multifactorial diseases and, hence, identifying the relative contribution of PE to offspring risk for CVD is a very complex task. However, considering the emerging strong association between PE and CVD, those exposed to PE in utero may benefit from targeted primary CVD preventive strategies.

Membrane proteomic analysis reveals the intestinal development is deteriorated by intrauterine growth restriction in piglets

The alterations of the intestinal proteome were observed in intrauterine growth restriction (IUGR) piglets during early life by gel-based approaches. Nevertheless, how IUGR affects the intestinal membrane proteome during neonatal development remains unclear. Here, we applied the iTRAQ-based proteomics technology and biochemical analysis to investigate the impact of IUGR on the membrane proteome of the jejunal mucosa in the piglets. Three hundred sixty-one membrane proteins were screened by functional prediction. Among them, eight, five, and one differentially expressed membrane proteins were identified between IUGR and NBW piglets at day 0, day 7, and day 21 after birth, respectively. Differentially expressed membrane proteins (DEMPs) including F1SBL3, F1RRW8, F1S539, F1S2Z2, F1RIR2, F1RUF2 I3LP60, Q2EN79, and F1SIH8 were reduced while the relative abundance of I3L6A2, F1SCJ1, F1RI18, I3LRJ7, and F1RNN0 were increased in IUGR piglets than NBW piglets. From the aspects of function, F1RRW8, F1S539, F1S2Z2, and F1RIR2 are mainly associated with D2 dopamine receptor binding, transmembrane transport of small molecules, signal transduction, and translocation of GLUT4, respectively, and F1SIH8, I3LRJ7, and F1RNN0 are related to autophagy, metabolism of vitamins, and intracellular protein transport. Additionally, IUGR decreased the level of proteins (F1RRW8, Q2EN79, and F1RI18) that are involved in response to oxidative stress.

Biomarkers of oxidative stress in the fetus and in the newborn

The dynamic field of perinatology entails ever-increasing search for molecular mechanisms of neonatal diseases, especially in the domain of fetal growth and neurodevelopmental outcome. There is an urgent need for new molecular biomarkers, to early identify newborn at high risk for developing diseases and to provide new treatment targets. The interest in biomarkers of oxidative stress in perinatal period have begun to grow in the last century, when it was evidenced the importance of the free radicals generation underlying the various disease conditions. To date, interesting researches have been carried out, representing milestones for implementation of oxidative stress biomarkers in perinatal medicine. Use of a panel of "oxidative stress biomarkers", particularly non protein bound iron, advanced oxidative protein products and isoprostanes, may provide valuable information regarding functional pathways underlying free radical mediated diseases of newborns and their early identification and prevention. Here, we will review recent advances and the current knowledge on the application of biomarkers of oxidative stress in neonatal/perinatal medicine including novel biomarker discovery, defining yet unrecognized biologic therapeutic targets, and linking of oxidative stress biomarkers to relevant standard indices and long-term outcomes.

BRCA1 regulates HMGA2 levels in the Swan71 trophoblast cell line

During early placental development, tumor suppressors and oncogenes work synergistically to regulate cell proliferation and differentiation in a restrained manner compared with the uncontrollable growth in cancer. One example of this partnership is the regulation of the oncofetal protein HMGA2 by BRCA1. BRCA1 forms a repressor complex with ZNF350 and CtIP to bind to the promoter of HMGA2, preventing transcription. Chromatin immunoprecipitation determined BRCA1 forms this repressor complex in human trophoblast cells, suggesting a role in the placenta. Furthermore, miR-182 has been shown to target BRCA1 mRNA in ovarian cancer cells, blocking the formation of the BRCA1 repressor complex and allowing increased transcription of HMGA2. miR-182 was one of the first miRNAs described as elevated in the serum and placentas of preeclamptic women. Therefore, we hypothesized that BRCA1 is essential for normal trophoblast cell development. We used CRISPR-Cas9 genome editing and miR-182 overexpression to decrease BRCA1 protein in the Swan71 cell line. HMGA2 was significantly increased in the BRCA1 KO and miR-182 overexpressing cells compared to controls. We also determined that BRCA1 repressor complex binding to HMGA2 was significantly reduced in BRCA1 KO and miR-182 overexpressing cells compared with controls, leading us to conclude that increased HMGA2 was because of decreased binding of the BRCA1 repressor complex. Finally, we found that the caspase activity was significantly higher in BRCA1 KO and miR-182 overexpressing cells suggesting an increased amount of apoptosis. These data suggest that BRCA1 is an important regulator of the oncofetal protein HMGA2 and promotes cell survival in human placental cells.

Potential role of microRNA-424 in regulating ERRγ to suppress trophoblast proliferation and invasion in fetal growth restriction

BACKGROUND

Abnormal expression of estrogen-related receptor γ (ERRγ) protein is associated with fetal growth restriction (FGR). The upstream regulators of ERRγ are still unknown.

OBJECTIVE

To evaluate the placental expression level of microRNA-424 (miR-424) and to demonstrate the relationship between miR-424 and FGR.

METHODS

The expression levels of miR-424 were detected in FGR and control placentas. HTR-8/SVneo cells were transfected with mimics or inhibitors to increase or decrease the miR-424 expression level, respectively. The transwell and CCK-8 assays were used to determine trophoblast-derived cell line invasion and proliferation. The expression levels of miR-424, ERRγ, and 17 beta-hydroxysteroid dehydrogenase type 1 (HSD17B1) were detected by qRT-PCR and Western blotting. The relationship between miR-424, ERRγ, and HSD17B1 was determined by luciferase reporter assay.

RESULTS

Compared to the normal pregnancy group, FGR placental tissues showed a significantly higher expression level of miR-424. The up-regulation of miR-424 decreased trophoblast-derived cell line invasion and proliferation. Down-regulation of miR-424 enhanced invasive and proliferative abilities of the cell lines. Over-expression of miR-424 reduced ERRγ protein levels and decreased both mRNA and protein levels of HSD17B1. Thus down-regulation of miR-424 induced protein expression of ERRγ and enhanced the mRNA and protein expressions of HSD17B1. MiR-424 probably mediated the expression of ERRγ via binding to sites other than mRNA 3'UTR.

CONCLUSION

MiR-424 may be associated with the pathogenesis of FGR by modulating trophoblast-derived cell line proliferation and invasion. MiR-424 may play a role in mediating the protein expressions of ERRγ and HSD17B1.

Placental Ageing in Adverse Pregnancy Outcomes: Telomere Shortening, Cell Senescence, and Mitochondrial Dysfunction

Preeclampsia is a multisystemic pregnancy disorder and a major cause of maternal and neonatal morbidity and mortality worldwide. The exact pathophysiology of preeclampsia remains unclear; however, it is speculated that the various pathologies can be attributed to impaired vascular remodelling and elevated oxidative stress within the placenta. Oxidative stress plays a key role in cell ageing, and the persistent presence of elevated oxidative stress precipitates cellular senescence and mitochondrial dysfunction, resulting in premature ageing of the placenta. Premature ageing of the placenta is associated with placental insufficiency, which reduces the functional capacity of this critical organ and leads to abnormal pregnancy outcomes. The changes brought about by oxidative insults are irreversible and often lead to deleterious modifications in macromolecules such as lipids and proteins, DNA mutations, and alteration of mitochondrial functioning and dynamics. In this review, we have summarized the current knowledge of placental ageing in the aetiology of adverse pregnancy outcomes and discussed the hallmarks of ageing which could be potential markers for preeclampsia and fetal growth restriction.

Placental hypoplasia and maternal organic vascular disorder in pregnant women with gestational hypertension and preeclampsia

Objective: This study aimed to investigate the etiology and pathology of preeclampsia (PE), a two-stage disorder involving uteroplacental dysfunction resulting from abnormal implantation and placentation, and gestational hypertension (GH), for which maternal organic vascular disorder is often an underlying factor.Methods: We assessed concentrations of oxygen free radicals (d-ROMs), maternal angiogenic factor (PlGF), and antiangiogenic factor (sFlt-1), placental hypoxic changes, oxidative DNA damage, and maternal organic vascular disorders in 23 women with PE (PE group), 13 with GH (GH group), and 16 with uncomplicated pregnancies (normal group). Intima-media thickness (IMT) of the carotid artery was assessed as a proxy for maternal organ vascular disorder. Immunohistochemical analysis was performed to measure the proportion of placental trophoblast cell nuclei staining positive for hypoxia-inducible factor-1α (HIF-1α), which reflects hypoxic changes, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), which reflects oxidative DNA damage.Results: Maternal serum d-ROM concentrations were significantly increased in both GH and PE groups relative to the normal group. Maternal serum d-ROM concentrations were significantly increased in both GH and PE groups relative to the normal group. Maternal serum sFlt-1 concentrations, ratio of sFlt-1/PlGF, and proportions of HIF-1α-positive nuclei and 8-OHdG-positive nuclei were significantly higher in the PE group compared to GH and normal groups. IMT was significantly greater in GH and PE groups compared to the normal group, and was higher in the GH group compared to the PE group.Conclusions: Our findings suggest that placental hypoxic changes and oxidative DNA damage are severe in patients with PE and accompanied by an increase in antiangiogenic factors. Moreover, maternal organ vascular disorder was more severe in patients with GH compared to those with PE, as assessed by IMT.Key message: PE is a two-stage disorder that involves uteroplacental dysfunction, and organic vascular disorder underlies GH.

Maternal serum and fetal cord-blood ischemia-modified albumin concentrations in normal pregnancy and preeclampsia: a systematic review and meta-analysis

BACKGROUND/AIMS

A meta-analysis of maternal serum ischemia-modified albumin (IMA) and fetal cord-blood IMA concentrations in normal pregnancy (NP) compared to non-pregnant healthy controls (HC) and in preeclampsia (PE) compared with normal pregnant controls were studied.

METHODS

All major databases were searched for eligible studies. We included eight studies comparing serum IMA between NP and HC, 14 studies comparing serum IMA between PE and NP and five studies comparing cord-blood IMA between PE and NP groups. Meta-analyses on these included studies were performed using Review Manager 5.3. Pooled-overall effect size as standardized mean difference (SMD), publication bias, subgroup, and sensitivity analysis data were generated.

RESULTS

Random-effects meta-analysis indicated a significant increase in serum IMA in the NP group (SMD = 0.98, p = .01) and the PE group (SMD = 0.94, p < .0001) as compared with HC and NP groups, respectively. And, the cord-blood IMA has been found to be significantly increased in PE (SMD = 6.51, p < .0001) compared with the NP group.

CONCLUSIONS

This meta-analysis, the first of its kind showed that the increased serum IMA concentrations were indicative of increased oxidative stress in NP and PE. Measurement of maternal serum IMA and fetal cord-blood IMA concentrations were useful as simple, novel, and inexpensive markers of oxidative stress (OS) status in PE patients. Future large-scale studies are needed to explore IMA in relationship to the disease severity in PE.

Oxidative Stress as Cause, Consequence, or Biomarker of Altered Female Reproduction and Development in the Space Environment

Oxidative stress has been implicated in the pathophysiology of numerous terrestrial disease processes and associated with morbidity following spaceflight. Furthermore, oxidative stress has long been considered a causative agent in adverse reproductive outcomes. The purpose of this review is to summarize the pathogenesis of oxidative stress caused by cosmic radiation and microgravity, review the relationship between oxidative stress and reproductive outcomes in females, and explore what role spaceflight-induced oxidative damage may have on female reproductive and developmental outcomes.

Melatonin treatment in fetal and neonatal diseases

This literature review aims to address the main scientific findings on oxidative stress activity in different gestational disorders, as well as the function and application of melatonin in the treatment of fetal and neonatal changes. Oxidative stress has been associated with the etiopathogenesis of recurrent miscarriages, preeclampsia, intrauterine growth restriction, and stillbirth. Both, the exacerbated consumption of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase, and the increased synthesis of reactive oxygen species, such as superoxide, peroxynitrite, and hydrogen peroxide, induce phospholipid peroxidation and endothelial dysfunction, impaired invasion and death of trophoblast cells, impaired decidualization, and remodeling of maternal spiral arteries. It has been postulated that melatonin induces specific biochemical responses that regulate cell proliferation in fetuses, and that its antioxidant action promotes bioavailability of nitric oxide and, thus, placental perfusion and also fetal nutrition and oxygenation. Therefore, the therapeutic action of melatonin has been the subject of major studies that aim to minimize or prevent different injuries affecting this pediatric age group, such as intrauterine growth restriction, encephalopathy, chronic lung diseases, retinopathy of prematurity Conclusion: the results antioxidant and indicate that melatonin is an important therapy for the clinical treatment of these diseases.

Implication of Oxidative Stress in Fetal Programming of Cardiovascular Disease

Lifestyle and genetic background are well known risk factors of cardiovascular disease (CVD). A third contributing factor is suboptimal fetal development, due to nutrient or oxygen deprivation, placental insufficiency, or exposure to toxic substances. The fetus adapts to adverse intrauterine conditions to ensure survival; the immediate consequence is low birth weight (LBW) and the long-term effect is an increased susceptibility to develop CVD in adult life. This process is known as Developmental Origins of Health and Disease (DOHaD) or fetal programming of CVD. The influence of fetal life for the future cardiovascular health of the individual has been evidenced by numerous epidemiologic studies in populations suffering from starvation during intrauterine life. Furthermore, experimental animal models have provided support and enabled exploring the underlying mechanisms. Oxidative stress seems to play a central role in fetal programming of CVD, both in the response of the feto-placental unit to the suboptimal intrauterine environment and in the alterations of physiologic systems of cardiovascular control, ultimately leading to disease. This review aims to summarize current knowledge on the alterations in oxidative balance in response to fetal stress factors covering two aspects. Firstly, the evidence from human studies of the implication of oxidative stress in LBW induced by suboptimal conditions during intrauterine life, emphasizing the role of the placenta. In the second part we summarize data on specific redox alterations in key cardiovascular control organs induced by exposure to known stress factors in experimental animals and discuss the emerging role of the mitochondria.

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.

Immune activation by nucleic acids: A role in pregnancy complications

Cell-free self-DNA or RNA may induce an immune response by activating specific sensing receptors. During pregnancy, placental nucleic acids present in the maternal circulation further activate these receptors due to the presence of unmethylated CpG islands. A higher concentration of cell-free foetal DNA is associated with pregnancy complications and a higher risk for foetal rejection. Cell-free foetal DNA originates from placental trophoblasts. It appears in different forms: free, bound to histones in nucleosomes, in neutrophil extracellular traps (NETs) and in extracellular vesicles (EVs). In several pregnancy complications, cell-free foetal DNA triggers the production of proinflammatory cytokines, and this production results in a cellular and humoral immune response. This review discusses preeclampsia, systemic lupus erythematosus, foetal growth restriction, gestational diabetes, rheumatoid arthritis and obesity in pregnancy from an immunological point of view and closely examines the different pathways that result in maternal inflammation. Understanding the role of cell-free nucleic acids, as well as the biogenesis of NETs and EVs, will help us to specify their functions or targets, which seem to be important in pregnancy complications. It is still not clear whether higher concentrations of cell-free nucleic acids in the maternal circulation are the cause or consequence of various complications. Therefore, further clinical studies and, even more importantly, animal experiments that focus on the involved immunological pathways are needed.

Evaluation of DNA Damage in Experimental Preeclampsia by Comet Assay

Experimental preeclampsia induced by substitution of drinking water with 1.8% NaCl during pregnancy was associated with an increase in the level of DNA damage in fetal brain and placenta measured by DNA comet assay by 35.7 and 27.8 times, respectively, in comparison with physiological pregnancy.

Evaluation of DNA damage profile in obese women and its association to risk of metabolic syndrome, polycystic ovary syndrome and recurrent preeclampsia

Metabolic syndrome (MS) is a cluster of metabolic abnormalities. Obesity and MS are always accompanied by elevated oxidative stress which might affect cellular bio-molecules such as DNA. The aim of the present study is to investigate DNA damage profile in obese premenopausal women and its relation to the risk of MS, polycystic ovary syndrome (PCOS) and history of recurrent pre-eclampsia. The study included 90 obese women included cases with MS (n = 30), PCOS (n = 30) and previous history of recurrent preeclampsia (n = 30) and, age-matched healthy non-obese control women (n = 50). The assessment of leukocyte DNA damage was done by comet assay for all cases and controls. Anthropometry and biochemical parameters have been measured. Results showed that mean percent of DNA damage was significantly higher in MS, PCOS as well as in women with the recurrent preeclampsia as compared to healthy controls. The high level of mean DNA damage frequency in obese women was significantly associated with the increased number of metabolic syndrome components. Cases with 2, 3 and 3-5 components showed significantly higher levels of DNA damage than controls. Moreover, cases with 3-5 MS components showed significant higher DNA compared to those with the two components. Regarding PCOS, significant positive association between the mean frequency of DNA damage and waist circumference was observed. The study suggests that metabolic abnormalities, PCOS and recurrent pre-eclampsia might be contributed in development of DNA damage in obese women. DNA damage can serve as an early marker for obesity complications in premenopausal women.

Genetic and microscopic assessment of the human chemotherapy-exposed placenta reveals possible pathways contributive to fetal growth restriction

INTRODUCTION

Fetal growth restriction (FGR) carries an increased risk of perinatal mortality and morbidity. A major cause of FGR is placental insufficiency. After in utero chemotherapy-exposure, an increased incidence of FGR has been reported. In a prospective cohort study we aimed to explore which pathways may contribute to chemotherapy-associated FGR.

METHODS

Placental biopsies were collected from 25 cancer patients treated with chemotherapy during pregnancy, and from 66 control patients. Differentially expressed pathways between chemotherapy-exposed patients and controls were examined by whole transcriptome shotgun sequencing (WTSS) and Ingenuity Pathway Analysis (IPA). Immunohistochemical studies for 8-OHdG and eNOS (oxidative DNA damage), proliferation (PCNA) and apoptosis (Cleaved Caspase 3) were performed. The expression level of eNOS, PCNA and IGFBP6 was verified by real-time quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR).

RESULTS

Most differential expressed genes between chemotherapy-exposed patients and controls were related to growth, developmental processes, and radical scavenging networks. The duration of chemotherapy exposure had an additional impact on the expression of genes related to the superoxide radicals degeneration network. Immunohistochemical analyses showed a significantly increased expression of 8-OHdG (P = 0.003) and a decreased expression of eNOS (P=0.015) in the syncytiotrophoblast of the placenta of cancer patients. A decreased expression of PCNA was detected by immunohistochemistry as RT-qPCR (NS).

CONCLUSION

Chemotherapy exposure during pregnancy results in an increase of oxidative DNA damage and might impact the placental cellular growth and development, resulting in an increased incidence of FGR in this specific population. Further large prospective cohort studies and longitudinal statistical analyses are needed.

Is there a role for placental senescence in the genesis of obstetric complications and fetal growth restriction?

The placenta ages as pregnancy advances, yet its continued function is required for a successful pregnancy outcome. Placental aging is a physiological phenomenon; however, there are some placentas that show signs of aging earlier than others. Premature placental senescence and aging are implicated in a number of adverse pregnancy outcomes, including fetal growth restriction, preeclampsia, spontaneous preterm birth, and intrauterine fetal death. Here we discuss cellular senescence, a state of terminal proliferation arrest, and how senescence is regulated. We also explore the role of physiological placental senescence and how aberrant placental senescence alters placental function, contributing to the pathophysiology of fetal growth restriction, preeclampsia, spontaneous preterm labor/birth, and unexplained fetal death.

Expression of von Willebrand factor and caldesmon in the placental tissues of pregnancies complicated with intrauterine growth restriction

PURPOSE

The decreased placental perfusion is the underlying reason for intrauterine growth restriction that in turn leads to reduced placental perfusion and ischemia. However, there are several issues to be understood in the pathophysiology of intrauterine growth restriction. We aimed to study whether any compensatory response in placental vascular bed occur in pregnancies complicated with intrauterine growth restriction by the immunohistochemical staining of von Willebrand factor and caldesmon in placental tissues.

MATERIALS AND METHODS

A total of 103 pregnant women was enrolled in the study including 50 patients who were complicated with IUGR and 50 uncomplicated control patients. The study was designed in a prospective manner. All placentas were also stained with von Willebrand factor and caldesmon monoclonal kits.

RESULTS

The immunohistochemical staining of von Willebrand factor and caldesmon expressions in placental tissues were different between normal and intrauterine growth restriction group. The percentages of 2+ and 3+ von Willebrand factor expression were higher in the intrauterine growth restriction group comparing with the normal group, although the difference was not statistically significant. The intensity of caldesmon expression was significantly lower in the intrauterine growth restriction group in comparison with the normal group (p < .001).

CONCLUSION

Angiogenesis occurs as a placental response to intrauterine growth restriction which is a hypoxic condition. But newly formed vessels are immature and not strong enough. Our study is important to clarify the pathophysiology and placental compensatory responses in intrauterine growth restriction.

Adult Consequences of Extremely Preterm Birth: Cardiovascular and Metabolic Diseases Risk Factors, Mechanisms, and Prevention Avenues

Extremely preterm babies are exposed to various sources of injury during critical stages of development. The extremely preterm infant faces premature transition to ex utero physiology and undergoes adaptive mechanisms that may be deleterious in the long term because of permanent alterations in organ structure and function. Perinatal events can also directly cause structural injury. These disturbances induce morphologic and functional changes in their organ systems that might heighten their risks for later adult chronic diseases. This review examines the pathophysiology of programming of long-term health and diseases after preterm birth and associated perinatal risk factors.

Repeated measures of inflammation and oxidative stress biomarkers in preeclamptic and normotensive pregnancies

BACKGROUND

Preeclampsia is a prevalent and enigmatic disease, in part characterized by poor remodeling of the spiral arteries. However, preeclampsia does not always clinically present when remodeling has failed to occur. Hypotheses surrounding the "second hit" that is necessary for the clinical presentation of the disease focus on maternal inflammation and oxidative stress. Yet, the studies to date that have investigated these factors have used cross-sectional study designs or small study populations.

OBJECTIVE

In the present study, we sought to explore longitudinal trajectories, beginning early in gestation, of a panel of inflammation and oxidative stress markers in women who went on to have preeclamptic or normotensive pregnancies.

STUDY DESIGN

We examined 441 subjects from the ongoing LIFECODES prospective birth cohort, which included 50 mothers who experienced preeclampsia and 391 mothers with normotensive pregnancies. Participants provided urine and plasma samples at 4 time points during gestation (median, 10, 18, 26, and 35 weeks) that were analyzed for a panel of oxidative stress and inflammation markers. Oxidative stress biomarkers included 8-isoprostane and 8-hydroxydeoxyguanosine. Inflammation biomarkers included C-reactive protein, the cytokines interleukin-1β, -6, and -10, and tumor necrosis factor-α. We created Cox proportional hazard models to calculate hazard ratios based on time of preeclampsia diagnosis in association with biomarker concentrations at each of the 4 study visits.

RESULTS

In adjusted models, hazard ratios of preeclampsia were significantly (P<.01) elevated in association with all inflammation biomarkers that were measured at visit 2 (median, 18 weeks; hazard ratios, 1.31-1.83, in association with an interquartile range increase in biomarker). Hazard ratios at this time point were the most elevated for C-reactive protein, for interleukin-1β, -6, and -10, and for the oxidative stress biomarker 8-isoprostane (hazard ratio, 1.68; 95% confidence interval, 1.14-2.48) compared to other time points. Hazard ratios for tumor necrosis factor-α were consistently elevated at all 4 of the study visits (hazard ratios, 1.49-1.63; P<.01). In sensitivity analyses, we observed that these associations were attenuated within groups typically at higher risk of experiencing preeclampsia, which include African American mothers, mothers with higher body mass index at the beginning of gestation, and pregnancies that ended preterm.

CONCLUSIONS

This study provides the most robust data to date on repeated measures of inflammation and oxidative stress in preeclamptic compared with normotensive pregnancies. Within these groups, inflammation and oxidative stress biomarkers show different patterns across gestation, beginning as early as 10 weeks. The start of the second trimester appears to be a particularly important time point for the measurement of these biomarkers. Although biomarkers alone do not appear to be useful in the prediction of preeclampsia, these data are useful in understanding the maternal inflammatory profile in pregnancy before the development of the disease and may be used to further develop an understanding of potentially preventative measures.

Placental oxidative stress and maternal endothelial function in pregnant women with normotensive fetal growth restriction

OBJECTIVE

The purpose of this study was to investigate the relationship between placental oxidative stress and maternal endothelial function in pregnant women with normotensive fetal growth restriction (FGR).

METHODS

We examined serum concentrations of oxygen free radicals (d-ROMs), maternal angiogenic factor (PlGF), and sFlt-1, placental oxidative DNA damage, and maternal endothelial function in 17 women with early-onset preeclampsia (PE), 18 with late-onset PE, 14 with normotensive FGR, and 21 controls. Flow-mediated vasodilation (FMD) was assessed as a marker of maternal endothelial function. Immunohistochemical analysis was performed to measure the proportion of placental trophoblast cell nuclei staining positive for 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage.

RESULTS

Maternal serum d-ROM, sFlt-1 concentrations, and FMD did not significantly differ between the control and normotensive FGR groups. The proportion of nuclei staining positive for 8-OHdG was significantly higher in the normotensive FGR group relative to the control group.

CONCLUSIONS

Our findings demonstrate that, despite the presence of placental oxidative DNA damage as observed in PE patients, pregnant women with normotensive FGR show no increase in the concentrations of sFlt-1 and d-ROMs, or a decrease in FMD.

Oxidative stress, placental ageing-related pathologies and adverse pregnancy outcomes

Oxidative stress (OS), an imbalance between free radical generation and antioxidant defence, is recognized as a key factor in the pathogenesis of adverse pregnancy outcomes. Although OS is a common future of normal pregnancy, persistent, overwhelming OS leads to consumption and decline of antioxidants, affecting placental antioxidant capacity and reducing systems. The accumulation of OS causes damage to lipids, proteins and DNA in the placental tissue that induces a form of accelerated ageing. Premature ageing of the placenta is associated with placental insufficiency that prevents the organ meeting the needs of the foetus, and as a consequence, the viability of the foetus is compromised. This review summarizes the literature regarding the role of OS and premature placental ageing in the pathophysiology of pregnancy complications.

Molecular hydrogen ameliorates several characteristics of preeclampsia in the Reduced Uterine Perfusion Pressure (RUPP) rat model

Oxidative stress plays an important role in the pathogenesis of preeclampsia. Recently, molecular hydrogen (H₂) has been shown to have therapeutic potential in various oxidative stress-related diseases. The aim of this study is to investigate the effect of H₂ on preeclampsia. We used the reduced utero-placental perfusion pressure (RUPP) rat model, which has been widely used as a model of preeclampsia. H₂ water (HW) was administered orally ad libitum in RUPP rats from gestational day (GD) 12-19, starting 2 days before RUPP procedure. On GD19, mean arterial pressure (MAP) was measured, and samples were collected. Maternal administration of HW significantly decreased MAP, and increased fetal and placental weight in RUPP rats. The increased levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and diacron reactive oxygen metabolites as a biomarker of reactive oxygen species in maternal blood were decreased by HW administration. However, vascular endothelial growth factor level in maternal blood was increased by HW administration. Proteinuria, and histological findings in kidney were improved by HW administration. In addition, the effects of H₂ on placental villi were examined by using a trophoblast cell line (BeWo) and villous explants from the placental tissue of women with or without preeclampsia. H₂ significantly attenuated hydrogen peroxide-induced sFlt-1 expression, but could not reduce the expression induced by hypoxia in BeWo cells. H₂ significantly attenuated sFlt-1 expression in villous explants from women with preeclampsia, but not affected them from normotensive pregnancy. The prophylactic administration of H₂ attenuated placental ischemia-induced hypertension, angiogenic imbalance, and oxidative stress. These results support the theory that H₂ has a potential benefit in the prevention of preeclampsia.

Dynamics of Base Excision Repair at the Maternal-Fetal Interface in Pregnancies Complicated by Preeclampsia

Preeclampsia (PE) (gestational proteinuric hypertension) is the leading cause of maternal and perinatal mortality worldwide. Although placental endothelial dysfunction and oxidative stress are known to contribute to PE, the exact pathological basis for this disorder remains unclear. Previously, we demonstrated that DNA damage at the maternal-fetal interface is more common in the placentas of women with PE than normotensive controls. In this study, we utilized an in vivo comparative study, including 20 preeclamptic women and 8 healthy control subjects, and an in vitro hypoxia/reperfusion model to mimic the effects of oxidative stress at the maternal-fetal interface. We tracked the spatial pattern of expression of 2 base excision repair proteins, 8-oxoguanine glycosylase (OGG1) and apurinic/apyrimidinic endonuclease-1 (APE1), at the maternal-fetal interface in response to oxidative stress. In vivo, we found a significant increase in OGG1 and APE1 concentrations in PE placental tissues as compared to normotensive controls ( P < .0001). Further, our in vitro study revealed that OGG1 and APE1 expression is much greater in maternal cells (decidua) than in fetal cells (cytotrophoblasts) of placental tissue subjected to oxidative stress ( P < .0001). Our results suggest that OGG1 and APE1 likely protect decidual cells from oxidative base damage.

Placental aging and oxidation damage in a tissue micro-array model: an immunohistochemistry study

To evaluate the expression of markers correlated with cellular senescence and DNA damage (8-hydroxy-2'-deoxy-guanosine (8-OHdG), p53, p21, APE1/Ref-1 (APE1), interleukin (IL-6 and IL-8) in placentas from healthy and pathologic pregnancies. This retrospective study considered a placental tissue micro-array containing 92 controls from different gestational ages and 158 pathological cases including preeclampsia (PE), HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count), small for gestational age (SGA) fetuses, and intrauterine growth restriction (IUGR) occurring at different gestational ages. In this study, we demonstrated a significant influence of gestational age on the expression in the trophoblast of 8-OHdG, p53, p21, APE1, and IL-6. In placentas of cases affected by PE, HELLP, or IUGR, there was an increased expression of 8-OHdG, p53, APE1, and IL-6 compared to controls (only IL-8 was significantly decreased in cases). In both groups of pathology between 22- and 34-week gestation and after 34-week gestation, APE1 levels were higher in the trophoblast of women affected by hypertensive disorders of pregnancy than women carrying an IUGR fetus. The cytoplasmic expression of 8-OHdG was increased in placentas in IUGR cases compared to PE or HELLP pregnancies. In cases after 34-week gestation, p21 was higher in SGA and IUGR than in controls and late PE. Moreover, p53 was increased after 34-week gestation in IUGR pregnancies. Placentas from pathological pregnancies had an altered expression of 8-OHdG, p53, p21, APE1, IL-6, and IL-8. The alterations of intracellular pathways involving these elements may be the cause or the consequence of placental dysfunction, but in any case reflect an impaired placental function, possibly due to increased aging velocity in pathologic cases.

Discordant HIF1A mRNA levels and oxidative stress in placental shares of monochorionic twins with selective intra-uterine growth restriction

INTRODUCTION

Oxidative stress is a key factor in the pathogenesis of intra-uterine growth restriction in singleton. However, its role in selective intra-uterine growth restriction (sIUGR) in monochorionic twins (MCT) is still unknown. This study explored the characteristics of oxidative stresses in the placenta shares of MCT and analyzed their possible connections with sIUGR.

METHODS

The placental levels of hypoxia inducible factor-1α gene (HIF1A)mRNA, malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) were evaluated in normal MCT (Group A) and sIUGR MCT (Group B). The results were compared between the placental shares of the larger twins (A1/B1) and smaller twins (A2/B2).

RESULTS

Placental HIF1A mRNA level significantly increased in Group B. Particularly, HIF1A mRNA level was elevated in the placenta share of the growth-restricted fetus (B2) than the co-twin (B1) (P = 0.036). More discordant HIF1A mRNA level was detected in Group B than Group A with larger inter-twin difference (P = 0.021). The levels of MDA and 8-OHdG were significantly higher in B2 than B1 in sIUGR MCT (P < 0.05). Both the inter-twin differences of MDA and 8-OHdG were also significantly larger in Group B (P < 0.05), indicating that discordant oxidative stress existed in the placental shares of sIUGR pregnancies. Finally, MDA concentration was found inversely correlated with neonatal birth weight, in both sIUGR (r = -0.650, P = 0.022) and normal MCT (r = -0.632, P = 0.027) pregnancies.

DISCUSSION

The elevation of HIF1A mRNA, and MDA/8-OHdG levels in placenta shares of sIUGR MCT suggests that oxidative stress may be involved in the pathogenesis of sIUGR.

Nitroso-redox balance and mitochondrial homeostasis are regulated by STOX1, a pre-eclampsia-associated gene

AIMS

Storkhead box 1 (STOX1) is a winged-helix transcription factor that is implicated in the genetic forms of a high-prevalence human gestational disease, pre-eclampsia. STOX1 overexpression confers pre-eclampsia-like transcriptomic features to trophoblastic cell lines and pre-eclampsia symptoms to pregnant mice. The aim of this work was to evaluate the impact of STOX1 on free radical equilibrium and mitochondrial function, both in vitro and in vivo.

RESULTS

Transcriptome analysis of STOX1-transgenic versus nontransgenic placentas at 16.5 days of gestation revealed alterations of mitochondria-related pathways. Placentas overexpressing STOX1 displayed altered mitochondrial mass and were severely biased toward protein nitration, indicating nitroso-redox imbalance in vivo. Trophoblast cells overexpressing STOX1 displayed an increased mitochondrial activity at 20% O2 and in hypoxia, despite reduction of the mitochondrial mass in the former. STOX1 overexpression is, therefore, associated with hyperactive mitochondria, resulting in increased free radical production. Moreover, nitric oxide (NO) production pathways were activated, resulting in peroxynitrite formation. At low oxygen pressure, STOX1 overexpression switched the free radical balance from reactive oxygen species (ROS) to reactive nitrogen species (RNS) in the placenta as well as in a trophoblast cell line.

INNOVATION

In pre-eclamptic placentas, NO interacts with ROS and generates peroxynitrite and nitrated proteins as end products. This process will deprive the maternal organism of NO, a crucial vasodilator molecule.

CONCLUSION

Our data posit STOX1 as a genetic switch in the ROS/RNS balance and suggest an explanation for elevated blood pressure in pre-eclampsia.

Oxidative stress-mediated aging during the fetal and perinatal periods

Oxidative stress is worldwide recognized as a fundamental component of the aging, a process that begins before birth. There is a critical balance between free radical generation and antioxidant defenses. Oxidative stress is caused by an imbalance between the production of free radicals and the ability of antioxidant system to detoxify them. Oxidative stress can occur early in pregnancy and continue in the postnatal period; this damage is implicated in the pathophysiology of pregnancy-related disorders, including recurrent pregnancy loss, preeclampsia and preterm premature rupture of membranes. Moreover, diseases of the neonatal period such as bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and periventricular leukomalacia are related to free radical damage. The specific contribution of oxidative stress to the pathogenesis and progression of these neonatal diseases is only partially understood. This review summarizes what is known about the role of oxidative stress in pregnancy and in the pathogenesis of common disorders of the newborn, as a component of the early aging process.

Oxidative stress in pregnancy and fertility pathologies

Oxidative stress designates the state of imbalance between reactive oxygen species (ROS) production and antioxidant levels. In a healthy placenta, there is an increase in ROS production, due to formation of new tissues and inherent metabolism, but this is balanced by higher levels of antioxidants. However, this balance is lost in some situations, with a consequent increase in oxidative stress levels. Oxidative stress has been implicated in several placental disorders and pregnancy pathologies. The present review intends to summarize what is known about the relationship between oxidative stress and well-known pregnancy disorders.