Oxidative stress in pregnancy and reproduction

Computational Models on Pathological Redox Signalling Driven by Pregnancy: A Review

Oxidative stress is associated with a myriad of diseases including pregnancy pathologies with long-term cardiovascular repercussions for both the mother and baby. Aberrant redox signalling coupled with deficient antioxidant defence leads to chronic molecular impairment. Abnormal placentation has been considered the primary source for reactive species; however, placental dysfunction has been deemed secondary to maternal cardiovascular maladaptation in pregnancy. While various therapeutic interventions, aimed at combating deregulated oxidative stress during pregnancy have shown promise in experimental models, they often result as inconclusive or detrimental in clinical trials, warranting the need for further research to identify candidates. The strengths and limitations of current experimental methods in redox research are discussed. Assessment of redox status and oxidative stress in experimental models and in clinical practice remains challenging; the state-of-the-art of computational models in this field is presented in this review, comparing static and dynamic models which provide functional information such as protein-protein interactions, as well as the impact of changes in molecular species on the redox-status of the system, respectively. Enhanced knowledge of redox biology in during pregnancy through computational modelling such as generation of Systems Biology Markup Language model which integrates existing models to a larger network in the context of placenta physiology.

The Pivotal Role of the Placenta in Normal and Pathological Pregnancies: A Focus on Preeclampsia, Fetal Growth Restriction, and Maternal Chronic Venous Disease

The placenta is a central structure in pregnancy and has pleiotropic functions. This organ grows incredibly rapidly during this period, acting as a mastermind behind different fetal and maternal processes. The relevance of the placenta extends far beyond the pregnancy, being crucial for fetal programming before birth. Having integrative knowledge of this maternofetal structure helps significantly in understanding the development of pregnancy either in a proper or pathophysiological context. Thus, the aim of this review is to summarize the main features of the placenta, with a special focus on its early development, cytoarchitecture, immunology, and functions in non-pathological conditions. In contraposition, the role of the placenta is examined in preeclampsia, a worrisome hypertensive disorder of pregnancy, in order to describe the pathophysiological implications of the placenta in this disease. Likewise, dysfunction of the placenta in fetal growth restriction, a major consequence of preeclampsia, is also discussed, emphasizing the potential clinical strategies derived. Finally, the emerging role of the placenta in maternal chronic venous disease either as a causative agent or as a consequence of the disease is equally treated.

Asperulosidic Acid, a Bioactive Iridoid, Alleviates Placental Oxidative Stress and Inflammatory Responses in Gestational Diabetes Mellitus by Suppressing NF-κB and MAPK Signaling Pathways

BACKGROUND

Asperulosidic acid (ASP) is a bioactive iridoid exerting broad pharmacological and medicinal properties. However, it is still unknown if ASP has therapeutical effects on gestational diabetes mellitus (GDM). This study aims to evaluate the effects of ASP on GDM as well as its underlying mechanism.

METHODS

A mouse model of GDM was established and orally administrated ASP (10, 20, and 40 mg/kg) on gestation day (GD) 0. The mice were sacrificed on GD 18.

RESULTS

Blood glucose and serum insulin were then determined. The inflammatory cytokines including IL-6 and TNF-α and oxidative stress biomarkers including MDA, SOD, GSH, and GPx were determined by using specific ELISAs. In addition, the expressions of NF-κB and MAPK signaling pathway-related proteins were determined by using Western blotting. Treatment with ASP decreased blood glucose in the mouse model of GDM. Besides, ASP also increased serum insulin and attenuated β-cell function. Treatment with ASP suppressed IL-6 and TNF-α and regulated oxidative stress-related biomarkers. Western blotting analysis showed that treatment with ASP suppressed phosphorylation of NF-κB p65, ERK1/2, and p38 in placental tissues.

CONCLUSION

ASP alleviates placental oxidative stress and inflammatory responses in GDM by the inhibition of the NF-κB and MAPK signaling pathways.

Ginger honey affects cortisol, estrogen and glutathione levels; preliminary study to target preconceptional women

OBJECTIVE

This study was aimed to determine the effect of ginger honey supplementation on cortisol, glutathione, and estrogen levels. The study was conducted on mice that had not yet experienced conception, and prior stress induction was carried out so that they could be continued for human trials at the preconception stage and subjects who experienced mild stress.

METHOD

It was an in vivo study, pretest-posttest control group design. The sample of this study was 2-3 months female Balb/c mice, divided into negative control and ginger honey intervention as much as 28mg/20g BW for 14 days-the ELISA method used to examine cortisol hormone, glutathione levels, and estrogen levels. The mice chosen were those that had never experienced conception, and before the intervention, swimming activities were carried out on the mice until they showed symptoms of stress.

RESULTS

Results show 42mg/20g BW of ginger honey administration for 14 days increased 1.892 ng/dl of cortisol (p = 0.165), increased 2.438 ng/dl of glutathione (p=0.002), and also increased 22.754ng/ml estrogen levels in induced stress Balb/c female mice (p=0.001).

CONCLUSION

Ginger honey did not affect reducing cortisol levels but increasing glutathione and estrogen levels significantly. Ginger honey supplements are the potential to use as complementary therapies.

Child serum metabolome and traffic-related air pollution exposure in pregnancy

BACKGROUND

Maternal exposure to traffic-related air pollution during pregnancy has been shown to increase the risk of adverse birth outcomes and childhood disorders. High-resolution metabolomics (HRM) has previously been employed to identify metabolic responses to traffic-related air pollution in adults, including pregnant women. Thus far, no studies have examined metabolic effects of air pollution exposure in utero on neonates.

METHODS

We retrieved stored neonatal blood spots for 241 children born in California between 1998 and 2007. These children were randomly selected from all California birth rolls to serve as birth-year matched controls for children with retinoblastoma identified from the California cancer registry for a case control study of childhood cancer. We estimated prenatal traffic-related air pollution exposure (particulate matter less than 2.5 μm (PM_2.5)) during the third-trimester using the California Line Source Dispersion Model, version 4 (CALINE4) based on residential addresses recorded at birth. We employed untargeted HRM to obtain metabolic profiles, and metabolites associated with air pollution exposure were identified using partial least squares (PLS) regression and linear regressions. Biological effects were characterized using pathway enrichment analyses adjusting for potential confounders including maternal age, race/ethnicity, and education.

RESULTS

In total we extracted 4038 and 4957 metabolite features from neonatal blood spots in hydrophilic interaction (HILIC) chromatography (positive ion mode) and C18 reverse phase columns (negative ion mode), respectively. After controlling for confounding factors, partial least square regression (Variable Importance in Projection (VIP) ≥ 2) selected 402 HILIC positive and 182 C18 negative features as statistically significantly associated with increasing third trimester PM_2.5 exposure. Using pathway enrichment analysis, we identified metabolites in oxidative stress and inflammation pathways as being altered, primarily involving lipid metabolism.

CONCLUSION

The metabolite features and pathways associated with air pollution exposure in neonates suggest that maternal exposure during late pregnancy contributes to oxidative stress and inflammation in newborn children.

Protective placental inflammatory and oxidative stress responses are attenuated in the context of twin pregnancy and chorioamnionitis in assisted reproduction

PURPOSE

Assisted reproduction technologies (ART) are associated with increased risks of pregnancy complications and obstetric interventions. Here, we aimed to determine if ART affects placental inflammation and oxidative stress as a mechanism for unfavorable pregnancy outcomes.

METHODS

The levels of six cytokines (IFN-γ, IL-1β, IL-6, IL-8, IL-10, TNFα) were measured using multiplex ELISA. The activity of four antioxidant enzymes (glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase, superoxide dismutase) and levels of two antioxidants (GSH, vitamin E) were measured using commercial/in-house assays. Markers were compared between ART and unassisted pregnancies, and then groups were stratified using ICD9/10 codes to determine differences in specific clinical contexts.

RESULTS

In unassisted twin pregnancies, there was a trend of decreased cytokine levels (IL-1β, IL-6, IL-8, TNFα, p < 0.05), but cytokines in ART twins were the same or higher. Additionally, GST and GPx activities were lower in unassisted twins, and vitamin E levels were higher in ART twins (p < 0.05). In pregnancies complicated by chorioamnionitis, there was a trend of increased cytokine levels in unassisted pregnancies (IL-1β, IL-6, and IL-8, p < 0.05). No increase was observed in ART, and IFN-γ and TNFα were decreased (p < 0.05). Placental GST and GPx activities were higher in unassisted pregnancies with chorioamnionitis compared to ART (p < 0.05).

CONCLUSION

Attenuation of protective placental inflammatory and oxidative stress responses may play a role in the underlying pathogenesis of negative birth outcomes in ART, expanding our understanding of adverse pregnancy outcomes when ART is used to conceive.

Towards Personalized Antioxidant Use in Female Infertility: Need for More Molecular and Clinical Studies

Treatment with antioxidants is increasingly used to slow down aging processes in different organs of the human body, including those implicated in female fertility. There is a plethora of different natural, synthetic or semi-synthetic medicines available on the market; most of them can be purchased without medical prescription. Even though the use of antioxidants, even under conditions of auto-medication, was shown to improve many functions related to female infertility related to oxidative stress, the lack of medical control and supervision can lead to an overmedication resulting in an opposite extreme, reductive stress, which can be counterproductive with regard to reproductive function and produce various adverse health effects in general. This paper reviews the current knowledge relative to the effects of different antioxidants on female reproductive function. The persisting gaps in this knowledge are also highlighted, and the need for medical supervision and personalization of antioxidant prescription is underscored.

The role of nuclear factor erythroid 2-related factor 2 (NRF2) in normal and pathological pregnancy: A systematic review

OBJECTIVE

A homeostatic balance between reactive oxygen species production and the antioxidant redox system is an important component of normal pregnancy. Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) preserves cellular homeostasis by enhancing the cell's innate antioxidant status to reduce oxidative stress and inflammatory damage to the cell during pregnancy. Active Nrf2, in the nucleus of the cell, transactivates various antioxidant genes. The objective of this systematic review was to synthesize evidence on the role of Nrf2 in various adverse pregnancy outcomes (APOs).

METHODS

We conducted a systematic review of the role of Nrf2 in pregnancy. Articles written in English, Portuguese, and Spanish were obtained from three different databases from inception until January 2021. The titles, abstracts and full text were reviewed independently by six reviewers. The quality of the included studies was assessed using a quality assessment tool developed to assess basic science and clinical studies. Nrf2 expression (gene and protein), functional contributions, and association with APOs were assessed.

RESULTS

A total of 747 citations were identified; 80 were retained for full review. Most studies on Nrf2 have been carried out using placental tissues and placenta-derived cells. Limited studies have been conducted using fetal membranes, uterus, and cervix. Nuclear translocation of Nrf2 results in transactivation of antioxidant enzymes, including glutathione peroxidase, hemeoxygenase-1, and superoxide dismutase in gestational cells during pregnancy. This antioxidant response maintains cellular homeostasis during pregnancy. This promotes trophoblast cell survival and prevents cell death and abnormal angiogenesis in the placenta. Excessive and insufficient Nrf2 response may promote oxidative and reductive stress, respectively. This Nrf2 dysregulation has been associated with APOs including gestational diabetes mellitus, intrauterine growth restriction, reproductive toxicity, preeclampsia, and preterm birth.

CONCLUSION

Several studies have localized and reported an association between Nrf2's differential expression in reproductive tissues and the pathogenesis of APOs. However, a comprehensive functional understanding of Nrf2 in reproductive tissues is still lacking. Nrf2's activation and functions are complex, and therefore, current in vitro and in vivo studies are limited in their experimental approaches. We have identified key areas for future Nrf2 research that is needed to fill knowledge gaps.

Cord Blood Manganese Concentrations in Relation to Birth Outcomes and Childhood Physical Growth: A Prospective Birth Cohort Study

Gestational exposure to manganese (Mn), an essential trace element, is associated with fetal and childhood physical growth. However, it is unclear which period of growth is more significantly affected by prenatal Mn exposure. The current study was conducted to assess the associations of umbilical cord-blood Mn levels with birth outcomes and childhood continuous physical development. The umbilical cord-blood Mn concentrations of 1179 mother-infant pairs in the Sheyang mini birth cohort were measured by graphite furnace atomic absorption spectrometry (GFAAS). The association of cord-blood Mn concentrations with birth outcomes, and the BMI z-score at 1, 2, 3, 6, 7 and 8 years old, were estimated separately using generalized linear models. The relationship between prenatal Mn exposure and BMI z-score trajectory was assessed with generalized estimating equation models. The median of cord-blood Mn concentration was 29.25 μg/L. Significantly positive associations were observed between Mn exposure and ponderal index (β, regression coefficient = 0.065, 95% CI, confidence interval: 0.021, 0.109; p = 0.004). Mn exposure was negatively associated with the BMI z-score of children aged 1, 2, and 3 years (β = -0.383 to -0.249, p < 0.05), while no significant relationships were found between Mn exposure and the BMI z-score of children at the age of 6, 7, and 8 years. Prenatal Mn exposure was related to the childhood BMI z-score trajectory (β = -0.218, 95% CI: -0.416, -0.021; p = 0.030). These results indicated that prenatal Mn exposure was positively related to the ponderal index (PI), and negatively related to physical growth in childhood, which seemed most significant at an early stage.

Risk Factors for Periventricular Leukomalacia in Preterm Infants: A Systematic Review, Meta-analysis, and GRADE-Based Assessment of Certainty of Evidence

BACKGROUND

We analyzed the certainty of evidence (CoE) for risk factors of periventricular leukomalacia (PVL) in preterm neonates, a common morbidity of prematurity.

METHODS

Medline, CENTRAL, Embase, and CINAHL were searched. Cohort and case-control studies and randomised randomized controlled trials were included. Data extraction was performed in duplicate. A random random-effects meta-analysis was utilizedused. CoE was evaluated as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

One hundred eighty-six studies evaluating 95 risk factors for PVL were included. Of the 2,509,507 neonates assessed, 16,569 were diagnosed with PVL. Intraventricular hemorrhage [adjusted odds ratio: 3.22 (2.52-4.12)] had moderate CoE for its association with PVL. Other factors such as hypocarbia, chorioamnionitis, PPROM >48 hour, multifetal pregnancy reduction, antenatal indomethacin, lack of antenatal steroids, perinatal asphyxia, ventilation, shock/hypotension, patent ductus arteriosus requiring surgical ligation, late-onset circulatory collapse, sepsis, necrotizing enterocolitis, and neonatal surgery showed significant association with PVL after adjustment for confounders (CoE: very low to low). Amongst the risk factors associated with mother placental fetal (MPF) triad, there was paucity of literature related to genetic predisposition and defective placentation. Sensitivity analysis revealed that the strength of association between invasive ventilation and PVL decreased over time (P < 0.01), suggesting progress in ventilation strategies. Limited studies had evaluated diffuse PVL.

CONCLUSION

Despite decades of research, our findings indicate that the CoE is low to very low for most of the commonly attributed risk factors of PVL. Future studies should evaluate genetic predisposition and defective placentation in the MPF triad contributing to PVL. Studies evaluating exclusively diffuse PVL are warranted.

The Role of Oxidative Stress and Antioxidant Balance in Pregnancy

It has been widely known that oxidative stress disrupts the balance between reactive oxygen species (ROS) and the antioxidant system in the body. During pregnancy, the physiological generation of ROS is involved in a variety of developmental processes ranging from oocyte maturation to luteolysis and embryo implantation. While abnormal overproduction of ROS disrupts these processes resulting in reproductive failure. In addition, excessive oxidative stress impairs maternal and placental functions and eventually results in fetal loss, IUGR, and gestational diabetes mellitus. Although some oxidative stress is inevitable during pregnancy, a balancing act between oxidant and antioxidant production is necessary at different stages of the pregnancy. The review aims to highlight the importance of maintaining oxidative and antioxidant balance throughout pregnancy. Furthermore, we highlight the role of oxidative stress in pregnancy-related diseases.

Cross talk: Trafficking and functional impact of maternal exosomes at the Feto-maternal Interface under normal and pathologic states

Fetal cell-derived exosomes promote inflammation in uterine and cervical cells to promote labor and delivery. However, the effect of maternal exosomes on fetal cells is still not known. We tested the hypothesis that cervical cells exposed to infectious and oxidative stress (OS) signals produce exosomes that can induce inflammation at the feto-maternal interface (FMi). Exosomes isolated from medium samples from human ectocervical epithelial cells (Ecto), endocervical epithelial cells (Endo), and cervical stromal cells (Stroma) in normal cell culture (control) or exposed to infection or OS conditions were characterized based on morphology, size, quantity, expression of tetraspanin markers, and cargo proteins. Human decidual, chorion trophoblast (CTC), chorion mesenchymal (CMC), amnion mesenchymal (AMC), and amnion epithelial cells (AEC) were treated with control, LPS-, or OS-treated cervical exosomes. ELISA for pro-inflammatory cytokines and progesterone was done to determine the recipient cells' inflammatory status. Ecto, endo, and stroma released ∼110 nm, cup-shaped exosomes. LPS and OS treatments did not affect exosome size; however, OS significantly increased the number of exosomes released by all cervical cells. Cervical exosomes were detected by fluorescence microscopy in each target cell after treatment. Exosomes from LPS- and CSE-treated cervical cells increased the inflammatory cytokine levels in the decidual cells, CMC, AMC, and AEC. LPS-treated stromal cell exosomes increased IL-6, IL-8, and progesterone in CTC. In conclusion, infection and OS can produce inflammatory cargo-enriched cervical exosomes that can destabilize FMi cells. However, the refractoriness of CTC to exosome treatments suggests a barrier function of the chorion at the FMi.

Benefits of α-lipoic acid in high-risk pregnancies (Review)

α-Lipoic acid (ALA) is a natural molecule that is inconsistently synthesized by the human body and must be provided from exogenous sources, such as food and dietary supplements. Once absorbed, the oxidized form of ALA is transformed into its reduced form, dihydrolipoic acid (DHLA). ALA/DHLA exert direct and indirect antioxidant, anti-inflammatory and fine immunomodulatory effects. ALA/DHLA reduce the levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and IL-17), while increasing the secretion of anti-inflammatory cytokines (IL-10). They also inhibit cyclooxygenase 2, thereby decreasing the secretion of prostaglandin E2 and nitrogen oxide, and reducing the risk of miscarriage in the first trimester of pregnancy. In patients at risk of abortion, administration of ALA from the first trimester has shown efficacy by accelerating subchorionic hematoma resorption, with a significant decrease in the accompanying abdominal pain. ALA has been proven to be efficient in maintaining the length of the cervix and keeping it closed following one episode of premature labor. Preeclampsia is a dysfunction caused by abnormal placentation and an excessive maternal inflammatory response, leading to extreme hypoxia in the placental bed and exaggerated oxidative stress, with release of oxygen free radicals. Oxidative stress plays a key role in the development of preeclampsia and intrauterine growth restriction. The hypothesis of antioxidant supplementation may play an essential part in disease prevention and fetal neuroprotection.

Effect of Endogenic and Exogenic Oxidative Stress Triggers on Adverse Pregnancy Outcomes: Preeclampsia, Fetal Growth Restriction, Gestational Diabetes Mellitus and Preterm Birth

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) in cells and tissues and the ability of a biological system to detoxify them. During a normal pregnancy, oxidative stress increases the normal systemic inflammatory response and is usually well-controlled by the balanced body mechanism of the detoxification of anti-oxidative products. However, pregnancy is also a condition in which this adaptation and balance can be easily disrupted. Excessive ROS is detrimental and associated with many pregnancy complications, such as preeclampsia (PE), fetal growth restriction (FGR), gestational diabetes mellitus (GDM), and preterm birth (PTB), by damaging placentation. The placenta is a tissue rich in mitochondria that produces the majority of ROS, so it is important to maintain normal placental function and properly develop its vascular network to ensure a safe and healthy pregnancy. Antioxidants may ameliorate these diseases, and related research is progressing. This review aimed to determine the association between oxidative stress and adverse pregnancy outcomes, especially PE, FGR, GDM, and PTB, and explore how to overcome this oxidative stress in these unfavorable conditions.

The Effect of Mobile Radiation on the Oxidative Stress Biomarkers in Pregnant Mice

Objective: Due to the growing use of communication instruments such as cell phones and wireless devices, there is growing public concern about possible harmful effects, especially in sensitive groups such as pregnant women. This study aimed to investigate the oxidative stress induced by exposure to 900 MHz mobile phone radiation and the effect of vitamin C intake on reducing possible changes in pregnant mice. Materials and methods: Twenty-one pregnant mice were divided into three groups (control, mobile radiation-exposed, and mobile radiation plus with vitamin C intake co-exposed (200 mg /kg)). The mice in exposure groups were exposed to 900 MHz, 2 watts, and a power density of 0.045 μw /cm2 mobile radiation for eight hours/day for ten consecutive days. After five days of rest, MDA (Malondialdehyde), 8-OHdG (8-hydroxy-2' -deoxyguanosine), and TAC (Total Antioxidant Capacity) levels were measured in the blood of animals. The results were analyzed by SPSS.22.0 software. Results: The results showed that exposure to mobile radiation increased MDA (P=0.002), and 8-OHdG (P=0.001) significantly and decreased Total Antioxidant Capacity in the exposed groups (P=0.001). Taking vitamin C inhibited the significant increase in MDA and 8-OHdG levels in exposed groups. Conclusion: Although exposure to mobile radiation can cause oxidative stress in the blood of pregnant mice, vitamin C as an antioxidant can prevent it.

Commentary: Novel strategies and new tools to curtail the health effects of pesticides

BACKGROUND

Flaws in the science supporting pesticide risk assessment and regulation stand in the way of progress in mitigating the human health impacts of pesticides. Critical problems include the scope of regulatory testing protocols, the near-total focus on pure active ingredients rather than formulated products, lack of publicly accessible information on co-formulants, excessive reliance on industry-supported studies coupled with reticence to incorporate published results in the risk assessment process, and failure to take advantage of new scientific opportunities and advances, e.g. biomonitoring and "omics" technologies.

RECOMMENDED ACTIONS

Problems in pesticide risk assessment are identified and linked to study design, data, and methodological shortcomings. Steps and strategies are presented that have potential to deepen scientific knowledge of pesticide toxicity, exposures, and risks. We propose four solutions: (1) End near-sole reliance in regulatory decision-making on industry-supported studies by supporting and relying more heavily on independent science, especially for core toxicology studies. The cost of conducting core toxicology studies at labs not affiliated with or funded directly by pesticide registrants should be covered via fees paid by manufacturers to public agencies. (2) Regulators should place more weight on mechanistic data and low-dose studies within the range of contemporary exposures. (3) Regulators, public health agencies, and funders should increase the share of exposure-assessment resources that produce direct measures of concentrations in bodily fluids and tissues. Human biomonitoring is vital in order to quickly identify rising exposures among vulnerable populations including applicators, pregnant women, and children. (4) Scientific tools across disciplines can accelerate progress in risk assessments if integrated more effectively. New genetic and metabolomic markers of adverse health impacts and heritable epigenetic impacts are emerging and should be included more routinely in risk assessment to effectively prevent disease.

CONCLUSIONS

Preventing adverse public health outcomes triggered or made worse by exposure to pesticides will require changes in policy and risk assessment procedures, more science free of industry influence, and innovative strategies that blend traditional methods with new tools and mechanistic insights.

Moringa oleifera Supplementation Improves Antioxidant Status and Biochemical Indices by Attenuating Early Pregnancy Stress in Beetal Goats

This study investigated the effects of supplementing different levels of Moringa oleifera leaf powder (MOLP) on antioxidant status and blood biochemical indices during early gestation in Beetal goats. A total of 30 goats were randomly divided into three groups (n = 10) comprising control (basal diet without MOLP), the 1.6% MOLP supplemented group (basal diet + 1.6% MOLP), and the 3.2% MOLP supplemented group (basal diet + 3.2% MOLP). The experiment started 5 days before estrus synchronization and lasted till day 60 of gestation. The MOLP significantly increased plasma flavonoids in 1.6% as well as 3.2% supplemented group on days 40 and 60 of pregnancy, while total phenolic contents were observed to be higher in the 3.2% MOLP supplemented group throughout the experiment in comparison with the control group. The supplementation improved plasma total antioxidant capacity (TAC) by decreasing malondialdehyde (MDA) and total oxidant status (TOS) in contrast to the control group. The activities of superoxide dismutase (SOD) and peroxidase (POD) were enhanced in both supplemented groups, whereas catalase (CAT) activity was noticed to be significantly high in the 3.2% MOLP supplemented group. The protein contents were significantly elevated with 1.6 and 3.2% supplementation levels from day 40 to day 60 of the experiment. Plasma sugar level, carotenoids, progesterone profile, and hydrolytic (protease and amylase) enzymes activities were improved only when supplemented with 3.2% MOLP. The findings suggest that supplementing with 3.2% MOLP provides beneficial effects on early pregnancy stress in Beetal goats.

Oxidative stress promotes cellular damages in the cervix: implications for normal and pathologic cervical function in human pregnancy†

A physiologic increase in reactive oxygen species throughout pregnancy is required to remodel the cervix. Oxidative stress can cause cellular damage that contributes to dysfunctional tissue. This study determined the oxidative stress-induced cell fate of human cervical epithelial and cervical stromal cells. We treated the ectocervical and endocervical epithelial cells and cervical stromal cells with cigarette smoke extract, an oxidative stress inducer, for 48 h. Cell viability (crystal violet assay); cell cycle, apoptosis, and necrosis (flow cytometry); senescence (senescence-associated β-galactosidase staining); autophagy (staining for autophagosome protein, microtubule-associated protein 1 light chain 3B); stress signaler p38 mitogen-activated protein kinases pathway activation (western blot analyses); and inflammation by measuring interleukin-6 (enzyme-linked immunosorbent assay) were conducted after 48 h of cigarette smoke extract treatment. Oxidative stress induced reactive oxygen species production in cervical cells, which was inhibited by N-acetylcysteine. Oxidative stress promoted cell cycle arrest and induced necrosis in cervical cells. High senescence and low autophagy were observed in cervical stromal cells under oxidative stress. Conversely, senescence was low and autophagy was high in endocervical epithelial cells. Oxidative stress induced p38 mitogen-activated protein kinases (p38MAPK) activation in all cervical cells but only increased interleukin-6 production by the ectocervical epithelial cells. Inhibition of interleukin-6 production by a p38 mitogen-activated protein kinases inhibitor confirmed the activation of an oxidative stress-induced pathway. In conclusion, oxidative stress can promote cell death and sterile inflammation that is mediated by p38 mitogen-activated protein kinases activation in the cellular components of the cervix. These cellular damages may contribute to the normal and premature cervical ripening, which can promote preterm birth.

Peripheral leucocyte molecular indicators of inflammation and oxidative stress are altered in dairy cows with embryonic loss

Objective of experiment was to determine whether oxidative stress (OS) and inflammation altered embryonic loss in dairy cows. Blood samples were collected at days 0, 16, 32 and 60 after timed (AI) from 200 Holstein cows to determine embryonic loss based on interferon-stimulated gene-15 (ISG15) mRNA expression (day 16) and ultrasound at day 32 and day 60. Leucocyte expressions of mRNA TLR2, TLR4, TNF-α, IL1B, IL10, STAT3 (inflammation), PTGS2, PTGES (prostaglandin synthesis), and PLA2G4A and ALOX5AP (eicosanoid metabolism) at days 0 and 16 were determined. Plasma redox status for antioxidant enzymatic activities of glutathione peroxidase (GPX), superoxide dismutase (SOD), total antioxidant capacity (TAC), and concentrations of malondialdehyde (MDA) were determined at days 0, 16, 32 and 60. All antioxidant-redox responses were beneficially significant in pregnant cows diagnosed pregnant at day16 and sustained pregnancy to day 60 compared to non-pregnant cows at day16 or pregnant at day16 and lost embryos by days 32 or 60. The leucocyte mRNA expressions of TLR2, TLR4, STAT 3, IL1B, PTGS2, PLA2G4A and ALOX5AP were greater and PTGES was lower at day16 in pregnant cows that lost embryos early (P < 0.05). In conclusion peripheral leucocyte molecular indicators of inflammation and plasma indicators of OS were altered in pregnant cows undergoing embryonic losses compared to cows with a sustained pregnancy.

The relationship between serum thiol levels and thiol/disulfide homeostasis in women with tubal ectopic pregnancy

OBJECTIVE

The aim of this study was to investigate the thiol/disulfide homeostasis in tubal ectopic pregnancies in terms of early diagnosis of the disease.

DESIGN

A prospective case-control study was carried out between June 2017-February 2018 in the Gynaecology Department of Umraniye Medical and Research Hospital.

MATERIALS AND METHODS

A total of 42 women with ectopic pregnancy were compared with 44 healthy women who have intrauterine first trimester pregnancies. The thiol/disulfide homeostasis is evaluated with the spectrophotometric measurement method that was recently developed by Erel&Neselioglu.

RESULTS

Disulfide/native thiol and disulfide/total thiol ratios were increased (p = 0.018 and p = 0.023 respectively), while native thiol/total thiol ratios and native thiol levels were decreased in tubal ectopic pregnancy group according to control group (p = 0.023). Between control and tubal ectopic pregnancy groups no differences were measured in disulfide levels (p = 0.350). The area under curve for native thiol and total thiol were 0.937 and 0.927, respectively. The optimum cut off value for native thiol was 379.95 μmol/l with a sensitivity of 90% and specificity of 81%. The optimum cut off value for total thiol was 432.5 μmol/l had 92% sensitivity and 79% specificity.

LIMITATIONS

In the study, whether intrauterine pregnancies resulted in miscarriage or delivery can be examined.

CONCLUSION

Increased disulfide/native thiol levels, disulfide/total-thiol ratio and decreased native/total thiol ratio were found to be significantly associated with the presence of tubal ectopic pregnancy which can be useful for the early diagnosis of the disease.

The Role of Oxidative Stress in Hypertensive Disorders of Pregnancy (Preeclampsia, Gestational Hypertension) and Metabolic Disorder of Pregnancy (Gestational Diabetes Mellitus)

Purpose of the Review.To highlight the role of oxidative stress in hypertensive disorders of pregnancy (HDP) and metabolic disorders of pregnancy (gestational diabetes mellitus). Recent Findings. In both preeclampsia (PE) and gestational hypertension (GH), oxidative stress leads to inadequate placental perfusion thus resulting in a hypoxic placenta, which generally leads to the activation of maternal systemic inflammatory response. In PE, this causes inflammation in the kidneys and leads to proteinuria. A proteinuria marker known as urinary 8-oxoGuo excretion is expressed in preeclampsia. In GDM, oxidative stress plays a role in the pathogenesis of the disease, as a result of over secretion of insulin during pregnancy. This uncontrolled secretion of insulin results in the production of lipid peroxidation factors that also mask the secretion of antioxidants. Therefore, ROS becomes abundant at cellular level and prevents the cells from transporting glucose to body tissues. Summary. There is a need for more research investigating the role of oxidative stress, especially in obstetrics-related conditions. More studies are required in order to understand the difference between the pathogenesis and pathophysiology of PE versus GH since investigations on the differences in genetic aspects of each condition are lacking. Furthermore, research to improve diagnostic procedures for GDM in pregnancy is needed.

Association between moderated level of air pollution and fetal growth: the potential role of noise exposure

This study aims to analyze, in a population of singletons, the potential confounding or modifying effect of noise on the relationship between fetal growth restriction (FGR) or small for gestational age (SGA) and environmental exposure to air pollution. All women with single pregnancies living in one of two medium-sized cities (Besançon, Dijon) and who delivered at a university hospital between 2005 and 2009 were included. FGR and SGA were obtained from medical records. Outdoor residential exposure to nitrogen dioxide (NO₂) and particulate matter (PM₁₀) was quantified at the mother’s address at delivery over defined pregnancy periods; outdoor noise exposure was considered to be the annual average daily noise levels in the façade of building (L_{Aeq,24 h}). Adjusted odds ratios (OR_a) were estimated by multivariable logistic regressions. Among the 8994 included pregnancies, 587 presented FGR and 918 presented SGA. In the two-exposure models, for SGA, the OR_a for a 10-µg/m³ increase of PM₁₀ during the two last months before delivery was 1.18, 95%CI 1.00–1.41 and for FGR, these OR_a were for the first and the third trimesters, and the two last months before delivery: 0.77 (0.61–0.97), 1.38 (1.12–1.70), and 1.35 (1.11–1.66), respectively. Noise was not associated with SGA or FGR and did not confound the relationship between air pollution and SGA or FGR. These results are in favor of an association between PM₁₀ exposure and fetal growth, independent of noise, particularly towards the end of pregnancy, and of a lack of association between noise and fetal growth.

Vitamin E and selenium supplementation synergistically alleviate the injury induced by hydrogen peroxide in bovine granulosa cells

Dairy cows are susceptible to reproductive disorders, which are thought to be associated with oxidative stress. In the study, we investigated the effects of vitamin E (VE) and selenium (Se) on the proliferation, apoptosis, and steroidogenesis in bovine ovarian granulosa cells under hydrogen peroxide (H₂O₂) - induced oxidative stress and elaborated the underlying mechanisms. Our results showed that VE or Se could stimulate the granulosa cell proliferation, possibly due to up-regulating the expression of CCND1 and decreasing the P21 levels under oxidative stress. VE or Se treatment also increased the secretion of estradiol (E2) and progesterone (P4), which could be owing to improving the expression of genes associated with steroidogenesis (StAR, HSD3β1, and CYP19A1) expression. VE or Se treatment down-regulated the apoptosis-related genes (BAX, CASP3) expression and decreased cell apoptosis. Furthermore, VE or Se treatment inhibited reactive oxidative species (ROS) and malondialdehyde (MDA) generation, increased total antioxidant capacity (T-AOC), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). Additionally, VE or Se treatment also alleviated the endoplasmic reticulum stress, activated the nuclear factor erythroid 2-related factor 2 (NRF2), and up-regulated the expression of its downstream genes, including NQO1, HO-1, GCLM, GCLC. More importantly, compared with either VE or Se treatment alone, their combined treatment showed a better protective effect against oxidative damage. Overall, our results indicated that VE and Se synergistically stimulated the granulosa cell proliferation and steroidogenesis, decreased cell apoptosis, mitigated the endoplasmic reticulum stress by activating the NRF2 signal pathway.

Umbilical Cord Blood Metal Mixtures and Birth Size in Bangladeshi Children

BACKGROUND

Studies have evaluated environmental exposure to toxic metals such as arsenic (As), cadmium (Cd), manganese (Mn), or lead (Pb) on birth size; however, information on potential effects of exposures to metal mixtures is limited.

OBJECTIVES

We assessed the association between metal mixtures (As, Cd, Mn, Pb) in umbilical cord blood and neonate size in Bangladeshi children.

METHODS

In this birth cohort study, pregnant women who were ≥18 years of age with an ultrasound-confirmed singleton pregnancy of ≤16wk gestation were recruited from two Bangladesh clinics between 2008 and 2011. Neonate size metrics were measured at the time of delivery. Metals in cord blood were measured using inductively coupled plasma mass spectrometry. We employed multivariable linear regression and Bayesian kernel machine regression (BKMR) to estimate associations of individual metals and metal mixtures with birth size parameters.

RESULTS

Data from 1,088 participants was assessed. We found a significant negative association between metal mixture and birth length and head circumference when all metal concentrations were above the 60th and 55th percentiles, respectively, compared with the median. An interquartile range (IQR) increase in log Cd concentration {log[Cd (in micrograms per deciliter)] IQR=2.51} was associated with a 0.13-standard deviation (SD) decrease in mean birth length (95% CI: -0.25, -0.02) and a 0.17-SD decrease in mean head circumference (95% CI: -0.28, -0.05), based on linear regression models adjusted for covariates and the other metals. An IQR increase in log Mn concentration {log[Mn (in micrograms per deciliter)] IQR=0.69} was associated with a 0.07-SD decrease in mean birth weight (95% CI: -0.15, 0.002).

DISCUSSION

Metal mixtures in cord blood were associated with reduced birth size in Bangladeshi children. Results from linear regression models adjusted and the BKMR mixtures analyses suggest adverse effects of Cd and Mn, as individual metal exposures, on birth size outcomes. https://doi.org/10.1289/EHP7502.

Recurrent miscarriage: evidence to accelerate action

Women who have had repeated miscarriages often have uncertainties about the cause, the likelihood of recurrence, the investigations they need, and the treatments that might help. Health-care policy makers and providers have uncertainties about the optimal ways to organise and provide care. For this Series paper, we have developed recommendations for practice from literature reviews, appraisal of guidelines, and a UK-wide consensus conference that was held in December, 2019. Caregivers should individualise care according to the clinical needs and preferences of women and their partners. We define a minimum set of investigations and treatments to be offered to couples who have had recurrent miscarriages, and urge health-care policy makers and providers to make them universally available. The essential investigations include measurements of lupus anticoagulant, anticardiolipin antibodies, thyroid function, and a transvaginal pelvic ultrasound scan. The key treatments to consider are first trimester progesterone administration, levothyroxine in women with subclinical hypothyroidism, and the combination of aspirin and heparin in women with antiphospholipid antibodies. Appropriate screening and care for mental health issues and future obstetric risks, particularly preterm birth, fetal growth restriction, and stillbirth, will need to be incorporated into the care pathway for couples with a history of recurrent miscarriage. We suggest health-care services structure care using a graded model in which women are offered online health-care advice and support, care in a nurse or midwifery-led clinic, and care in a medical consultant-led clinic, according to clinical needs.

Increased homocysteine mediated oxidative stress as key determinant of hepatitis E virus (HEV) infected pregnancy complication and outcome: A study from Northeast India

With the background of association of oxidative stress and Hepatitis E virus (HEV) infection in pregnancy complications the present novel study aimed to evaluate the significance of changes in maternal homocysteine levels and the related mechanism(s) in the pathophysiology of HEV related pregnancy complications and negative outcomes. Term delivery (TD, N = 194) and HEV-IgM positive pregnancy cases [N = 109] were enrolled. Serum and placental homocysteine levels were evaluated by ELISA and immunofluorescence and in turn correlated with serum Vitamin B12 levels. Distribution of variant MTHFR C➔T and TYMS1494del6bp genotyping were studied by PCR-RFLP. Differential folate receptor alpha (FR-α) expression in placenta was evaluated by real-time PCR and immunofluorescence respectively. The HEV viral load was significantly higher in both FHF and AVH cases. Higher serum homocysteine levels was associated with preterm delivery (PTD) and fetal death in HEV infected cases and was significantly inversely correlated with serum VitaminB12 levels in HEV cases. Placental homocysteine expression was upregulated in HEV cases, and in cases with negative pregnancy outcome. A Homocysteine level was associated with MTHFR C677T status. Genetic alterations in folate pathway was associated with increased risk of PTD in HEV infected pregnancy cases, disease severity, and negative pregnancy outcome in AVH and FHF groups. FR-α expression was downregulated in placental tissues of HEV infected pregnancy.Placental stress caused by HEV inflicted increased homocysteine due to alterations in maternal vitamin B12 levels and folate pathway components is detrimental mechanism in PTD and negative pregnancy outcome in HEV infected pregnancy cases and holds prognostic and therapeutic significance.

Maternal Dietary Selenium Intake during Pregnancy and Neonatal Outcomes in the Norwegian Mother, Father, and Child Cohort Study

Properly working antioxidant defence systems are important for fetal development. One of the nutrients with antioxidant activity is selenium. Increased maternal selenium intake has been associated with reduced risk for being small for gestational age and preterm delivery. Based on the Norwegian Mother, Father, and Child Cohort Study and the Medical Birth Registry of Norway, we investigated the association of maternal selenium intake from food and dietary supplements during the first half of pregnancy (n = 71,728 women) and selenium status in mid-pregnancy (n = 2628 women) with neonatal health, measured as two composite variables (neonatal morbidity/mortality and neonatal intervention). Low maternal dietary selenium intake (<30 µg/day) was associated with increased risk for neonatal morbidity/mortality (adjusted odds ratio (adjOR) 1.36, 95% confidence interval (95% CI) 1.08–1.69) and neonatal intervention (adjOR 1.16, 95% CI 1.01–1.34). Using continuous variables, there were no associations between maternal selenium intake (from diet or supplements) or whole-blood selenium concentration and neonatal outcome in the adjusted models. Our findings suggest that sufficient maternal dietary selenium intake is associated with neonatal outcome. Adhering to the dietary recommendations may help ensure an adequate supply of selenium for a healthy pregnancy and optimal fetal development.

The Association Among Maternal Index of Nutritional Quality, Dietary Antioxidant Index, and Odds of Miscarriage Incidence: Case-Control Study

OBJECTIVE

Miscarriage is a pregnancy condition in which the fetus or embryo naturally dies before being able to survive independently. According to studies, diet and dietary factors are associated with the risk of miscarriage (pregnancies <20 weeks). A 168-item semi-quantitative feed frequency questionnaire was used to estimate the Dietary Antioxidant Index (DAI) and the Index of Nutritional Quality (INQ). We aimed to assess the relationship between INQ and DAI with odds of miscarriage.

METHOD

In summary, 135 Iranian women with a history of three or more miscarriages were included. We calculated the INQ using the following formula: INQ = consumed amount of a nutrient per 1,000 kcal/Recommended Dietary Allowance of that nutrient per 1,000 kcal. We standardized each dietary vitamins/minerals by subtracting the global mean and dividing the result by the universal standard deviation to compute DAI. We computed the DAI by summing up the standardized intakes of these vitamins and minerals and equal weight.

RESULTS

Regression models were used to extract the odds ratios (ORs) and 95% confidence intervals (CIs) in crude and multivariate adjustments. Controls significantly had higher INQ of vitamin B12, niacin, vitamin D, vitamin E, vitamin C, and zinc. Modeling INQs of vitamin D (OR: 0.004, 95% CI, 0.00-0.025) and B12 (OR: 0.04, 95% CI, 0.005-0.41) as a continuous variable showed a significant and protective effect in multivariate adjustment. Modeling DAI as a categorical variable showed a significant protective effect (OR_{DAI<0.054vs.DAI ≥0.054} = 0.43, 95% CI, 0.20-0.91).

CONCLUSIONS

Recommending a diet rich in antioxidants such as vitamin E, C, zinc, and selenium and a quality diet containing vitamins B12 and D can be considered an effective strategy to reduce the odds of miscarriage in women with a history of recurrent miscarriage.

The Impact of Early Pregnancy and Exposure to Tobacco Smoke on Blood Antioxidant Status and Copper, Zinc, Cadmium Concentration-A Pilot Study

The aim of the study was to evaluate the impact of early pregnancy and exposure to tobacco smoke on antioxidant status and copper, zinc, and cadmium concentrations in the blood of non-smoking and smoking, as well as non-pregnant or pregnant women. The study included 213 women. More specifically, 150 women in first trimester of pregnancy and 63 non-pregnant women. Women were divided into subgroups according to exposure to tobacco smoke. Pregnancy significant influences higher copper and lower zinc concentration in the serum, whereas exposure to tobacco smoke during pregnancy is mainly associated with an elevation in cadmium and zinc concentration. It seems that metallothionein, superoxide dismutase, and glutathione peroxidase are the important antioxidants during early pregnancy, when exposure to tobacco smoke occurs, whereas the pregnancy itself is associated with a higher concentration of metallothionein and activity of catalase. Both pregnancy in the first trimester and exposure to tobacco smoke decrease glutathione concentration. In addition, active and passive maternal smoking have a similarly negative effect on antioxidant status in the first trimester. Early pregnancy as well as exposure to tobacco smoke is associated with significant alteration in antioxidant status and copper, zinc, and cadmium concentration. Due to a small number of smoking subjects (11 cases of non-pregnant, active smokers and 14 pregnant active smokers), the obtained results should be treated as a pilot, and this should be considered for future studies.

Effects of perioperative oxygen concentration on oxidative stress in adult surgical patients: a systematic review

BACKGROUND

The fraction of inspired oxygen (FiO2) administered during general anaesthesia varies widely despite international recommendations to administer FiO2 0.8 to all anaesthetised patients to reduce surgical site infections (SSIs). Anaesthetists remain concerned that high FiO2 administration intraoperatively may increase harm, possibly through increased oxidative damage and inflammation, resulting in more complications and worse outcomes. In previous systematic reviews associations between FiO2 and SSIs have been inconsistent, but none have examined how FiO2 affects perioperative oxidative stress. We aimed to address this uncertainty by reviewing the available literature.

METHODS

EMBASE, MEDLINE, and Cochrane databases were searched from inception to March 9, 2020 for RCTs comparing higher with lower perioperative FiO2 and quantifying oxidative stress in adults undergoing noncardiac surgery. Candidate studies were independently screened by two reviewers and references hand-searched. Methodological quality was assessed using the Cochrane Collaboration Risk of Bias tool.

RESULTS

From 19 438 initial results, seven trials (n=422) were included. Four studies reported markers of oxidative stress during Caesarean section (n=328) and three reported oxidative stress during elective colon surgery (n=94). Risk of bias was low (four studies) to moderate (three studies). Pooled results suggested high FiO2 was associated with greater malondialdehyde, protein-carbonyl concentrations and reduced xanthine oxidase concentrations, together with reduced antioxidant markers such as superoxide dismutase and total sulfhydryl levels although total antioxidant status was unchanged.

CONCLUSIONS

Higher FiO2 may be associated with elevated oxidative stress during surgery. However, limited studies have specifically reported biomarkers of oxidation. Given the current clinical controversy concerning perioperative oxygen therapy, further research is urgently needed in this area.

Impact of Melatonin on Full-Term Fetal Brain Development and Transforming Growth Factor-β Level in a Rat Model of Preeclampsia

Preeclampsia (PE) is a leading cause of stroke and cognitive impairment in the offspring. Melatonin is involved in the outcome of normal pregnancy. Its receptors are widespread in the embryo. This study aimed to investigate the fetal neuroprotective effect of melatonin in experimentally induced PE. After induction of pregnancy in 18 female rats, they were divided into three equal groups. PE was induced in groups II and III by injection of deoxycorticosterone acetate and drinking isotonic saline. Melatonin was supplied to group III orally (10 mg/kg body weight) throughout pregnancy. Pregnancy was terminated on day 20, and macroanatomical investigation of three fetuses from each pregnant rat and their placentae was performed. Placental and brain homogenates were analyzed for malondialdehyde (MDA), placental growth factor (PLGF), tumor necrosis factor-α (TNF-α), and brain transforming growth factor-β (TGF-β). Histopathological analysis of fetal brain sections was performed. Melatonin improved placental, fetal, and brain weight; significantly reduced fetal death rate; significantly increased PLGF, placental and brain superoxide dismutase, and brain TGF-β; and significantly decreased placental TNF-α and brain MDA. Brain micromorphological study found normal glial cells and neuropil in the melatonin-treated group and a loss of neuronal cell outlines with an accumulation of cellular debris in the untreated group. In conclusion, melatonin approximately showed a neuroprotective activity by managing PE-induced oxidative stress in the placenta and fetal cerebral cortex of rats.

Biomarkers of Toxicant Exposure and Inflammation Among Women of Reproductive Age Who Use Electronic or Conventional Cigarettes

Background: Electronic cigarettes (e-cigarettes) generally have a more favorable toxicant profile than conventional cigarettes; however, limited information exists for women of reproductive age (WRA). Our aim was to compare biomarkers of toxicant exposure, inflammation, and oxidative stress among WRA who self-report exclusive e-cigarette use, exclusive cigarette smoking, or never tobacco use (controls). Methods: Multivariable linear regression models were used to compare the geometric means of urinary biomarkers of toxicant exposure and their metabolites, serum markers of inflammation [highly sensitive C-reactive protein, soluble intercellular adhesion molecule (sICAM), interleukin 6, fibrinogen], and a measurement of oxidative stress [prostaglandin F2a-8-isoprostane (F2PG2a)] among WRA from the Population Assessment of Tobacco and Health survey. Results: E-cigarette users had higher levels of lead, tobacco-specific nitrosamines, nicotine metabolites, and some volatile organic compounds (VOCs) than controls. Except for cadmium and lead, e-cigarette users had lower levels of the analyzed urinary toxicant biomarkers compared with cigarette smokers. Cigarette smokers had higher levels of all the biomarkers of toxicant exposure than controls. There were no significant differences in the levels of markers of inflammation and oxidative stress between e-cigarette users and controls. E-cigarette users and controls had lower levels of sICAM and F2PG2a than cigarette smokers. Conclusion: WRA who use e-cigarettes had lower levels of some of the evaluated urinary biomarkers of toxicant exposure and serum biomarkers of inflammation and oxidative stress than those who smoke cigarettes, but higher lead, nicotine metabolites, and some VOCs than controls, which can increase health risks.

Air Pollution and Adverse Pregnancy and Birth Outcomes: Mediation Analysis Using Metabolomic Profiles

PURPOSE OF REVIEW

Review how to use metabolomic profiling in causal mediation analysis to assess epidemiological evidence for air pollution impacts on birth outcomes.

RECENT FINDINGS

Maternal exposures to air pollutants have been associated with pregnancy complications and adverse pregnancy and birth outcomes. Causal mediation analysis enables us to estimate direct and indirect effects on outcomes (i.e., effect decomposition), elucidating causal mechanisms or effect pathways. Maternal metabolites and metabolic pathways are perturbed by air pollution exposures may lead to adverse pregnancy and birth outcomes, thus they can be considered mediators in the causal pathways. Metabolomic markers have been used to explain the biological mechanisms linking air pollution and respiratory function, and of arsenic exposure and birth weight. However, mediation analysis of metabolomic markers has not been used to assess air pollution effects on adverse birth outcomes. In this article, we describe the assumptions and applications of mediation analysis using metabolomic markers that elucidate the potential mechanisms of the effects of air pollution on adverse pregnancy and birth outcomes. The hypothesis of mediation along specified pathways can be assessed within the structural causal modeling framework. For causal inferences, several assumptions that go beyond the data-including no uncontrolled confounding-need to be made to justify the effect decomposition. Nevertheless, studies that integrate metabolomic information in causal mediation analysis may greatly improve our understanding of the effects of ambient air pollution on adverse pregnancy and birth outcomes as they allow us to suggest and test hypotheses about underlying biological mechanisms in studies of pregnant women.

SOD2 deficiency-induced oxidative stress attenuates steroidogenesis in mouse ovarian granulosa cells

This study investigated the effects of SOD2 (MnSOD)-deficiency-induced excessive oxidative stress on ovarian steroidogenesis in vivo and isolated and cultured granulosa cells using WT and Sod2+/- mice. Basal and 48 h eCG-stimulated plasma progesterone levels were decreased ~50% in female Sod2+/- mice, whereas plasma progesterone levels were decreased ~70% in Sod2+/- mice after sequential stimulation with eCG followed by hCG. Sod2+/- deficiency caused about 50% reduction in SOD2 activity in granulosa cells. SOD2-deficiency also caused a marked reduction in progestins and estradiol in isolated granulosa cells. qRT-PCR measurements indicated that the mRNA expression levels of StAR protein and steroidogenic enzymes are decreased in the ovaries of Sod2+/- mice. Further studies showed a defect in the movement of mobilized cytosolic cholesterol to mitochondria. The ovarian membrane from Sod2+/- mice showed higher susceptibility to lipid peroxidation. These data indicates that SOD2-deficiency induced oxidative stress inhibits ovarian granulosa cell steroidogenesis primarily by interfering with cholesterol transport to mitochondria and attenuating the expression of Star protein gene and key steroidogenic enzyme genes.

Role of Dietary Amino Acids and Nutrient Sensing System in Pregnancy Associated Disorders

Defective implantation is related to pregnancy-associated disorders such as spontaneous miscarriage, intrauterine fetal growth restriction and others. Several factors proclaimed to be involved such as physiological, nutritional, environmental and managemental that leads to cause oxidative stress. Overloading of free radicals promotes oxidative stress, and the internal body system could not combat its ability to encounter the damaging effects and subsequently leading to pregnancy-related disorders. During pregnancy, essential amino acids display important role for optimum fetal growth and other necessary functions for continuing fruitful pregnancy. In this context, dietary amino acids have received much attention regarding the nutritional concerns during pregnancy. Arginine, glutamine, tryptophan and taurine play a crucial role in fetal growth, development and survival while ornithine and proline are important players for the regulation of gene expression, protein synthesis and angiogenesis. Moreover, amino acids also stimulate the mammalian target of rapamycin (mTOR) signaling pathway which plays a central role in the synthesis of proteins in placenta, uterus and fetus. This review article explores the significances of dietary amino acids in pregnancy development, regulation of nutrient-sensing pathways such as mTOR, peroxisome proliferator-activated receptors (PPARs), insulin/insulin-like growth factor signaling pathway (IIS) and 5' adenosine monophosphate-activated protein kinase (AMPK) which exhibit important role in reproduction and its related problems. In addition, the antioxidant function of dietary amino acids against oxidative stress triggering pregnancy disorders and their possible outcomes will also be enlightened. Dietary supplementation of amino acids during pregnancy could help mitigate reproductive disorders and thereby improving fertility in animals as well as humans.

Vitamin E and Selenium Treatment Alleviates Saline Environment-Induced Oxidative Stress through Enhanced Antioxidants and Growth Performance in Suckling Kids of Beetal Goats

Salinity is a worldwide, threatening problem affecting socioeconomic status globally. Saline land comprises salt content in soil, plants, and drinking water. Livestock farming is the worthy option for proper utilization of saline land in a cost-effective approach. Animals reared on this land experience a variety of stresses. Such stresses promote oxidative stress and reduced animal performance. The purpose of this study was to investigate the antioxidative function of vitamin E and selenium (Se) on pregnant/nonpregnant animals reared on the saline environment. A total of 36 multiparous pregnant (n = 18) and nonpregnant (n = 18) goats weighing about 38-45 (average 41.5) kg were equally divided into control and supplemented groups. The experiment lasted from 120 days of gestation to 15 days after parturition for pregnant goats and 0 to 45 days for nonpregnant cyclic goats (>50 days post-kidding). The supplemented group was administered vitamin E (1000 mg/kg BW) and selenium (3 mg/50 kg BW), while the control group was kept on normal saline (0.9% NaCl) with the same route 15 days apart. The blood samples were collected with 15 days apart during the entire experimental period of 45 days and subjected to assessment of enzymatic/nonenzymatic antioxidants, hydrolytic enzymes, oxidants, stress metabolic biomarkers, Se, and progesterone concentration of (pregnant) animals. Results revealed that vitamin E and Se supplementation significantly enhanced the activity of enzymatic (catalase and peroxidase) and nonenzymatic antioxidants such as total phenolic/flavonoid content and vitamin C and increased blood plasma level of Se concentration in comparison with the control group (P < 0.01). Exposure to antioxidant supplementation mitigated lipid peroxidation and enhanced progesterone level and total antioxidant capacity (P < 0.01) as compared to the control group in pregnant goats. Administration of vitamin E and selenium promoted kid survival rate (100%) along with increased initial birth weight, daily average weight gain, and total weight gain in comparison with the control group. Besides, the twinning rate and sex ratio were also recorded in pregnant animals. It is concluded that vitamin E and Se supplementation ameliorated salinity-induced oxidative stress, improved antioxidant status, and enhanced reproductive and growth performance of suckling kids reared on saline land.

Association of Oxidative Stress on Pregnancy

The pathophysiological mechanism underlying pregnancy complications such as congenital malformations, miscarriage, preeclampsia, or fetal growth restriction is not entirely known. However, the negative impact of the mother's body oxidative imbalance on the fetus and the course of gestation is increasingly discussed. This article is an integrative review of some original studies and review papers on the effects of oxidative stress on the adverse pregnancy outcomes mainly birth defects in fetuses. A systematic search for English language articles published from 2010 until 2020 was made, using MEDLINE data. Additionally, we analyzed the Cochrane and Scopus databases, discussions with experts, and a review of bibliography of articles from scientifically relevant and valuable sources. The main purposes are to assess the contribution of the existing literature of associations of oxidative stress on the etiology of the abovementioned conditions and to identify relevant information and outline existing knowledge. Furthermore, the authors aim to find any gaps in the research, thereby providing grounds for our own research. The key search terms were "oxidative stress in pregnancy," "oxidative stress and congenital malformations," and "oxidative stress and adverse pregnancy outcomes." Studies have confirmed that oxidative stress has a significant impact on pregnancy and is involved in the pathomechanism of adverse pregnancy outcomes.

Stretch, scratch, and stress: Suppressors and supporters of senescence in human fetal membranes

INTRODUCTION

Throughout gestation, amnion membranes undergo mechanical and or physiological stretch, scratch, or stress which is withstood by repairing and remodeling processes to protect the growing fetus. At term, increased oxidative stress (OS) activates p38MAPK, induces senescence, and inflammation contributing to membrane dysfunction to promote labor. However, the signaling initiated by stretch and scratch is still unclear. This study compares the induction of p38MAPK mediated senescence by stretch, scratch, and stress in human amnion epithelial cells (AECs).

METHODS

Primary AECs from term, not-in-labor, fetal membranes were cultured using the following conditions (N = 3); 1) CellFlex chambers with or without 20% biaxial stretch, 2) 8-well coverslips with or without scratch, and 3) cells exposed to cigarette smoke extract (CSE) inducing OS. p38MAPK (Western blot or immunocytochemistry), senescence activation, and inflammation (matrix metalloproteinases 9 [MMP9] activity-ELISA) were determined in cells exposed to various conditions. T-test and One-Way ANOVA was used to assess significance.

RESULTS

Biological membrane extension, mimicked by 20% biaxial stretch of AEC, maintained an epithelial morphology and activated P-p38MAPK (P = 0.02) compared to the non-stretch controls, but did not induce senescence or MMP9 activation. AEC scratches were healed within 40-hrs, which included proliferation, migration, and cellular transitions aided by p38MAPK activation but not senescence. CSE induced OS increased p38MAPK (P = 0.018) activation, senescence (P = 0.019), and MMP9 (P = 0.02).

CONCLUSION

Physiologic stretch and scratch experienced during gestation can cause p38MAPK activation without causing senescence or inflammation. This may be indicative of p38MAPK's role in tissue remodeling during pregnancy. Overwhelming OS, experienced at term, results in P-p38MAPK mediated senescence and inflammation to disrupt membrane remodeling.

Vaginal Lactoferrin Administration Decreases Oxidative Stress in the Amniotic Fluid of Pregnant Women: An Open-Label Randomized Pilot Study

Background: Oxidative stress (OxS) has been linked to several pregnancy-related complications. Previous studies demonstrated that lactoferrin (LF) has the ability to modulate inflammation, OxS and the immune function. Therefore, we aimed to observe whether vaginal LF administration was able to decrease OxS in the amniotic fluid (AF) of pregnant women undergoing mid-trimester genetic amniocentesis. Methods: In this open-label clinical study, 60 pregnant women were divided into three groups: CONTROLS (n = 20), not treated with LF; LACTO 4HRS (n = 20), treated with LF 4 h prior to amniocentesis; LACTO 12HRS (n = 20), treated with LF 12 h prior to amniocentesis. Thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS) and oxidative stress index (OSI) were measured in AF samples. In addition, the in vitro antioxidant activity of LF on a cell line was tested. Results: LF decreased the concentration of TBARS in the AF, with LACTO 4HRS demonstrating the lowest value compared with CONTROLS (P < 0.0001). LACTO 4HRS had higher TAS and lower OSI than CONTROLS (P < 0.0001 for both). In vitro, LF was effective against the oxidative challenge regardless of the time of pretreatment. Conclusion: In conclusion, LF decreased both in vivo and in vitro OxS. LF administration may represent an intriguing clinical solution as an adjuvant to treat complications of pregnancy related to inflammation and OxS. Trial Registration: Clinicaltrials.gov, NCT02695563. Registered 01 March 2016-Retrospectively registered, https://clinicaltrials.gov/show/NCT02695563.

Oxidative stress levels and oral bacterial milieu in the saliva from pregnant vs. non-pregnant women

Background

Saliva plays a significant role in maintaining oral health and oral bacterial milieu. Difference in oxidative stress (OS) levels in saliva in conjunction with bacterial load between pregnant and non-pregnant women has not been studied previously. We hypothesized that the physiological changes in pregnancy alter oral bacterial milieu by promoting growth of Streptococcus mutans (SM) and Lactobacillus (LB), and increase OS in saliva. The aim of this study was to measure and compare the oral bacterial milieu, OS and total anti-oxidative capacity (TAC) in the saliva of pregnant and non-pregnant women.

Method

In this cross-sectional study, we assessed oral bacterial milieu by culturing the SM and LB by using commercial kits, TAC by measuring 2, 2′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid (ABTS) free radical scavenging activity spectrophotometrically and OS levels by measuring malondialdehyde (MDA) levels with commercial kits in the saliva of pregnant women (n = 38) at 18–20 weeks of gestation, who were compared with age-matching healthy non-pregnant women (n = 50).

Results

Streptococcus mutans were found to be more abundant in the saliva of pregnant women compared with non-pregnant women (p = 0.003) but the difference was not significant for the LB (p = 0.267). TAC was found to be 46% lower in pregnant women’s saliva compared to non-pregnant women [optical density (OD) measured at 731 nm as 0.118 ± 0.01 vs. 0.063 ± 0.02; p < 0.001]. OS, expressed as saliva MDA levels, was found to be 16% higher in pregnant women compared to non-pregnant women (1.07 nM MDA vs. 0.92 nM MDA; p = 0.023).

Conclusion

Pregnancy has an adverse impact on oral bacterial milieu as demonstrated by increased colonization with Streptococcus mutans together with higher OS levels and decreased TAC levels in saliva. This emphasizes the importance of improved oral hygiene and provision of oral healthcare services during pregnancy care.

The effect of PEGylated iron oxide nanoparticles on sheep ovarian tissue: An ex-vivo nanosafety study

Today, nanotechnology plays an important role in our ever-continuous quest to improve the quality of human life. Because of their infinitesimal size, nanostructures can actively interact and alter cellular functions. Therefore, while the clinical benefits of nanotechnology may outweigh most of the associated risks, assessment of the cytotoxicity of nanostructures in respect to cells and tissues early in product development processes is of great significance. To the best of our knowledge, no such assessment has been performed for nanomaterials on the ovarian cortex before. Herein, silica-coated, PEGylated silica-coated, and uncoated iron oxide nanoparticles (IONP) with core diameter of 11 nm (±4.2 nm) were synthesized. The oxidative stress in cultured ovarian tissue exposed to the various IONP was subsequently assessed. The results indicate that among the four groups, uncoated IONP induce the most oxidative stress on the ovarian cortex while tissues treated with PEGylated IONP exhibit no significant change in oxidative stress.

Altered gestational outcomes and delayed pubertal onset in prenatally and early postnatally food restricted male and female rats: mitigation by quercetin and kaempferol

Nutrigenomic malnutrition during pregnancy and early postnatal life has serious consequences on original organ-programing, growth pattern, puberty and quality of life. The aim of this was to investigate the effect of two notable flavonoids, quercetin and kaempferol, with nutrigenomic potentials on prenatal and early postnatal food restrictions or both on gestational outcomes and the onset of puberty in male and females Wister rats. In three sets of experiments consisting of prenatal, postnatal food deprivations or both, rats were distributed into various treatment groups (n = 6). Prenatal food restriction (PrNFR) was initiated by 50% of ad libitum available diet in pregnancy (days 1-22) simultaneously with quercetin (50, 100 and 200 mg/kg, p.o./day) or kaempferol (50, 100 and 200 mg/kg, p.o./day) until delivery. However, postnatal food restriction (PsNFR) was simulated by litter-increment to 16 pups per mother from postnatal day 2 together with quercetin (50-200 mg/kg, p.o.) or kaempferol (50-200 mg/kg, p.o.) treatments until weaning (day 24) respectively. The last experiment encompasses both protocols with similar treatment protocols. Kaempferol attenuated PrNFR-induced alterations in gestational length compared to PrNFR-control. Quercetin and kaempferol significantly (P < 0.05) normalized nose-length of pups of rats exposed to PrNFR. Quercetin and kaempferol reduced the number of stillbirths due to PrNFR. Both also reduced the delay in pubertal onset as evidenced by normal onset of balanopreputial-separation and vaginal-opening in the PrNFR, PsNFR and PrNFR-PsNFR male and female rats respectively. Together, quercetin and kaempferol prevents prenatal and postnatal malnutrition-induced altered gestational outcomes and pubertal delays in rats.

Role of ROS/RNS in Preeclampsia: Are Connexins the Missing Piece?

Preeclampsia is a pregnancy complication that appears after 20 weeks of gestation and is characterized by hypertension and proteinuria, affecting both mother and offspring. The cellular and molecular mechanisms that cause the development of preeclampsia are poorly understood. An important feature of preeclampsia is an increase in oxygen and nitrogen derived free radicals (reactive oxygen species/reactive nitrogen species (ROS/RNS), which seem to be central players setting the development and progression of preeclampsia. Cell-to-cell communication may be disrupted as well. Connexins (Cxs), a family of transmembrane proteins that form hemichannels and gap junction channels (GJCs), are essential in paracrine and autocrine cell communication, allowing the movement of signaling molecules between cells as well as between the cytoplasm and the extracellular media. GJCs and hemichannels are fundamental for communication between endothelial and smooth muscle cells and, therefore, in the control of vascular contraction and relaxation. In systemic vasculature, the activity of GJCs and hemichannels is modulated by ROS and RNS. Cxs participate in the development of the placenta and are expressed in placental vasculature. However, it is unknown whether Cxs are modulated by ROS/RNS in the placenta, or whether this potential modulation contributes to the pathogenesis of preeclampsia. Our review addresses the possible role of Cxs in preeclampsia, and the plausible modulation of Cxs-formed channels by ROS and RNS. We suggest these factors may contribute to the development of preeclampsia.

Oxidative status of maternal blood in pregnancies burdened by inherited thrombophilias

Oxidative status of maternal blood represents an important parameter of pregnancy that is involved in both, regulation of physiological processes and (if significantly altered) development of different pregnancy complications. Inherited thrombophilias represent genetic disorders that increase the risk of thromboembolism in pregnancy. Little is known about the impact of thrombophilia on the oxidative status of maternal blood. In this study, we analyzed oxidative status of blood of 56 women with pregnancies burdened by inherited thrombophilias. The status was established at three different trimesters using biochemical assays and electrochemical measurements, and it was compared to 10 age- and trimester-matching controls. Activities of superoxide dismutase, catalase, and glutathione reductase in the 1st and the 2nd trimester of thrombophilic pregnancy were lower than controls. Also, there was less oxidation in the plasma, according to higher concentration of reduced thiols and lower oxidation-reduction potential. Therefore, it appears that thrombophilic mothers do not experience oxidative stress in the circulation in the first two trimesters. However, the rise in GPx, GR and SOD activities in the 3rd trimester of thrombophilic pregnancy implies that the risk of oxidative stress is increased during the late pregnancy. These results are important for developing antioxidative treatment that could tackle thrombophilia-related pregnancy complications.

The Role of Danger Associated Molecular Patterns in Human Fetal Membrane Weakening

The idea that cellular stress (including that precipitated by stretch), plays a significant role in the mechanisms initiating parturition, has gained considerable traction over the last decade. One key consequence of this cellular stress is the increased production of Danger Associated Molecular Patterns (DAMPs). This diverse family of molecules are known to initiate inflammation through their interaction with Pattern Recognition Receptors (PRRs) including, Toll-like receptors (TLRs). TLRs are the key innate immune system surveillance receptors that detect Pathogen Associated Molecular Patterns (PAMPs) during bacterial and viral infection. This is also seen during Chorioamnionitis. The activation of TLR commonly results in the activation of the pro-inflammatory transcription factor Nuclear Factor Kappa-B (NF-kB) and the downstream production of pro-inflammatory cytokines. It is thought that in the human fetal membranes both DAMPs and PAMPs are able, perhaps via their interaction with PRRs and the induction of their downstream inflammatory cascades, to lead to both tissue remodeling and weakening. Due to the high incidence of infection-driven Pre-Term Birth (PTB), including those that have preterm Premature Rupture of the Membranes (pPROM), the role of TLR in fetal membranes with Chorioamnionitis has been the subject of considerable study. Most of the work in this field has focused on the effect of PAMPs on whole pieces of fetal membrane and the resultant inflammatory cascade. This is important to understand, in order to develop novel prevention, detection, and therapeutic approaches, which aim to reduce the high number of mothers suffering from infection driven PTB, including those with pPROM. Studying the role of sterile inflammation driven by these endogenous ligands (DAMPs) activating PRRs system in the mesenchymal and epithelial cells in the amnion is important. These cells are key for the maintenance of the integrity and strength of the human fetal membranes. This review aims to (1) summarize the knowledge to date pertinent to the role of DAMPs and PRRs in fetal membrane weakening and (2) discuss the clinical potential brought by a better understanding of these pathways by pathway manipulation strategies.

Mitochondria, spermatogenesis, and male infertility - An update

The incorporation of mitochondria in the eukaryotic cell is one of the most enigmatic events in the course of evolution. This important organelle was thought to be only the powerhouse of the cell, but was later learnt to perform many other indispensable functions in the cell. Two major contributions of mitochondria in spermatogenesis concern energy production and apoptosis. Apart from this, mitochondria also participate in a number of other processes affecting spermatogenesis and fertility. Mitochondria in sperm are arranged in the periphery of the tail microtubules to serve to energy demand for motility. Apart from this, the role of mitochondria in germ cell proliferation, mitotic regulation, and the elimination of germ cells by apoptosis are now well recognized. Eventually, mutations in the mitochondrial genome have been reported in male infertility, particularly in sluggish sperm (asthenozoospermia); however, heteroplasmy in the mtDNA and a complex interplay between the nucleus and mitochondria affect their penetrance. In this article, we have provided an update on the role of mitochondria in various events of spermatogenesis and male fertility and on the correlation of mitochondrial DNA mutations with male infertility.

Prenatal and early postnatal food restrictions cause changes in brain oxidative status and orexigenic/anorexigenic hormones in the offspring of rats: prevention by quercetin and kaempferol

Brain oxidative signaling pathways have been identified as important targets for alleviating food deprivation-induced changes in metabolic gate-ways. Previous studies have shown that prenatal and early postnatal malnutrition alters leptin and ghrelin signaling via oxidative pathways. Thus, it has been hypothesized that agents with antioxidant properties might be beneficial for the mitigation of prenatal and early postnatal food scarcity-induced oxidative damage. Quercetin and kaempferol are natural bioflavonoids with proven antioxidant properties. In this study, we evaluated their effects on prenatal maternal food consumption, maternal and pup weights, biomarkers of orexigenic and anorexigenic hormones and oxidative stress in rats. Rats were allotted into different treatment groups (n ​= ​6) in three different experiments (prenatal, postnatal food-deprivations or both). Prenatal-food restriction (PrNFR) was induced by 50% of ad libitum accessible diet during pregnancy till parturition and postnatal-food restriction (PsNFR) was simulated by litter-enlargement to 16 pups per mother from postnatal day (PND) 2. Rats in each experiment were concurrently treated with vehicle (10 ​mL/kg), quercetin (50, 100 and 200 ​mg/kg, p.o.) or kaempferol (50, 100 and 200 ​mg/kg, p.o.) respectively. A third experimental group consisted of both protocols. Quercetin and kaempferol dose-dependently increased the body weights of pups exposed to PrNFR, PsNFR and PrNFR-PsNFR at PNDs 1-22 respectively. Both compounds increased maternal body weights but attenuated maternal food-intake at prenatal days 7 and 14 due by PrNFR. Quercetin and kaempferol reduced brain malondialdehyde concentrations and increased glutathione levels in PrNFR, PsNFR and PrNFR-PsNFR-exposed offspring of rats. Importantly, quercetin and kaempferol significantly (p ​< ​0.05) prevented PrNFR-, PsNFR- or PrNFR-PsNFR-induced alterations in leptin and ghrelin levels. Cumulatively, quercetin and kaempferol increased pup and maternal weights and attenuated maternal food-intake of rats submitted to PrNFR, PsNFR and PrNFR-PsNFR respectively, likely via nutrigenomic modulations of orexigenic/anorexigenic hormones and inhibition of brain oxidative stress.