Epigenetic Genome Modifications during Pregnancy: The Impact of Essential Nutritional Supplements on DNA Methylation

Pregnancy is an extremely stressful period in a pregnant woman's life. Currently, women's awareness of the proper course of pregnancy and its possible complications is constantly growing. Therefore, a significant percentage of women increasingly reach for various dietary supplements during gestation. Some of the most popular substances included in multi-ingredient supplements are folic acid and choline. Those substances are associated with positive effects on fetal intrauterine development and fewer possible pregnancy-associated complications. Recently, more and more attention has been paid to the impacts of specific environmental factors, such as diet, stress, physical activity, etc., on epigenetic modifications, understood as changes occurring in gene expression without the direct alteration of DNA sequences. Substances such as folic acid and choline may participate in epigenetic modifications by acting via a one-carbon cycle, leading to the methyl-group donor formation. Those nutrients may indirectly impact genome phenotype by influencing the process of DNA methylation. This review article presents the current state of knowledge on the use of folic acid and choline supplementation during pregnancy, taking into account their impacts on the maternal-fetal unit and possible pregnancy outcomes, and determining possible mechanisms of action, with particular emphasis on their possible impacts on epigenetic modifications.

One-carbon metabolite supplementation to nutrient-restricted beef heifers affects placental vascularity during early pregnancy

We hypothesized that restricted maternal nutrition and supplementation of one-carbon metabolites (OCM; methionine, folate, choline, and vitamin B12) would affect placental vascular development during early pregnancy. A total of 43 cows were bred, and 32 heifers successfully became pregnant with female calves, leading to the formation of four treatment groups: CON - OCM (n = 8), CON + OCM (n = 7), RES - OCM (n = 9), and RES + OCM (n = 8). The experimental design was a 2 × 2 factorial, with main factors of dietary intake affecting average daily gain: control (CON; 0.6 kg/d ADG) and restricted (RES; -0.23 kg/d ADG); and OCM supplementation (+OCM) in which the heifers were supplemented with rumen-protected methionine (7.4 g/d) and choline (44.4 g/d) and received weekly injections of 320 mg of folate and 20 mg of vitamin B12, or received no supplementation (-OCM; corn carrier and saline injections). Heifers were individually fed and randomly assigned to treatment at breeding (day 0). Placentomes were collected on day 63 of gestation (0.225 of gestation). Fluorescent staining with CD31 and CD34 combined with image analysis was used to determine the vascularity of the placenta. Images were analyzed for capillary area density (CAD) and capillary number density (CND). Areas evaluated included fetal placental cotyledon (COT), maternal placental caruncle (CAR), whole placentome (CAR + COT), intercotyledonary fetal membranes (ICOT, or chorioallantois), intercaruncular endometrium (ICAR), and endometrial glands (EG). Data were analyzed with the GLM procedure of SAS, with heifer as the experimental unit and significance at P ≤ 0.05 and a tendency at P > 0.05 and P < 0.10. Though no gain × OCM interactions existed (P ≥ 0.10), OCM supplementation increased (P = 0.01) CAD of EG, whereas nutrient restriction tended (P < 0.10) to increase CAD of ICOT and CND of COT. Additionally, there was a gain × OCM interaction (P < 0.05) for CAD within the placentome and ICAR, such that RES reduced and supplementation of RES with OCM restored CAD. These results indicate that maternal rate of gain and OCM supplementation affected placental vascularization (capillary area and number density), which could affect placental function and thus the efficiency of nutrient transfer to the fetus during early gestation.

Folate-depletion alters mouse trophoblast stem cell regulation in vitro

Maternal folate deficiency increases risk of congenital malformations, yet its effect on placenta development is unclear. Here, we investigated how folate-depleted culture medium affects the developmental potential of mouse trophoblast stem cells (TSCs). When cultured in stem cell conditions, TSC viability was unaffected by folate depletion, but ectopic differentiation of trophoblast cell subtypes occurred. When cultured in conditions that promote differentiation, folate-depleted TSCs were driven towards a syncytiotrophoblast cell fate potentially at the expense of other lineages. Additionally, trophoblast giant cell nuclei were small implicating folate in the regulation of endoreduplication. Therefore, dietary folate intake likely promotes trophoblast development.

Recent Advances in Folates and Autoantibodies against Folate Receptors in Early Pregnancy and Miscarriage

Though firstly identified in cerebral folate deficiency, autoantibodies against folate receptors (FRAbs) have been implicated in pregnancy complications such as miscarriage; however, the underlying mechanism needs to be further elaborated. FRAbs can be produced via sensitization mediated by folate-binding protein as well as gene mutation, aberrant modulation, or degradation of folate receptors (FRs). FRAbs may interfere with folate internalization and metabolism through blocking or binding with FRs. Interestingly, different types of FRs are expressed on trophoblast cells, decidual epithelium or stroma, and macrophages at the maternal-fetal interface, implying FRAbs may be involved in the critical events necessary for a successful pregnancy. Thus, we propose that FRAbs may disturb pregnancy establishment and maintenance by modulating trophoblastic biofunctions, placental development, decidualization, and decidua homeostasis as well as the functions of FOLR2+ macrophages. In light of these findings, FRAbs may be a critical factor in pathological pregnancy, and deserve careful consideration in therapies involving folic acid supplementation for pregnancy complications.

Diverse associations observed between pregnancy complications and RBC or plasma folates determined by an in-house developed LC-MS/MS method

BACKGROUND

As folates are essential for embryonic development and growth, it is necessary to accurately determine the levels of folates in plasma and red blood cells (RBCs) for clinical intervention. The aims of this study were to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantitation of folates in plasma and RBCs and to examine the association between plasma and RBC folate concentrations and gestational diabetes mellitus (GDM), gestational hypertension (GH) and preeclampsia (PE).

METHODS

With the in-house developed LC-MS/MS, a retrospective cross-sectional study was conducted. The healthy pregnant women of first- (n = 147), second- (n = 84) and third-trimester (n = 141) or the women diagnosed with GDM (n = 84), GH (n = 58) or PE (n = 23), that were aged between 22 and 46 years old and registered at our institute, were subjected for measurement of folic acid (FA) and 5-methyltetrahydrofolate (5-MTHF), followed by appropriate statistical association analysis.

RESULTS

The assay for simultaneous quantitation of FA and 5-MTHF in plasma and RBCs was linear, stable, with imprecision less than 15% and recoveries within ±10%. The lower limits of quantification for FA and 5-MTHF measurement in whole blood were 0.57 and 1.09 nmol/L, and in plasma were 0.5 and 1 nmol/L, respectively. In the association analysis, the patients with lower RBC folate level (<906 nmol/L) presented higher risks of PE development (OR 4.861 [95% CI 1.411-16.505]) by logistic regression and restricted cubic spline (RCS) regression in a nonlinear fashion. In addition, higher level of plasma folates in pregnancy was significantly associated with GH risk but may be protective for the development of GDM.

CONCLUSIONS

The in-house developed LC-MS/MS method for folates and metabolites in plasma or RBC showed satisfactory analytical performance for clinical application. Further, the levels of folates and metabolites were diversely associated with GDM, GH and PE development.

Maternal candidate gene variants, epigenetic factors, and susceptibility to idiopathic recurrent pregnancy loss: A systematic review

BACKGROUND

Recurrent pregnancy loss is defined as the loss of two or more pregnancies and is a distressing condition for couples.

OBJECTIVE

To investigate the relationship between variants in the candidate susceptibility genes and epigenetic factors to identify risk factors for idiopathic recurrent pregnancy loss (iRPL).

SEARCH STRATEGY

A systematic literature search was performed using PubMed, Google Scholar, ScienceDirect, and Scopus databases. Insilico analysis was carried out using ShinyGO and STRING software.

SELECTION CRITERIA

Research papers examining the association between variations in genetic and epigenetic factors and iRPL.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two authors.

MAIN RESULTS

In total, 83 research papers were finally selected for the present study. Among all the genes involved in the pathogenesis of recurrent pregnancy loss, polymorphisms in IL superfamily genes, VEGF, ESR, and MTHFR were the most investigated.

CONCLUSION

Polymorphisms in angiogenesis, immune tolerance, and thrombophilia pathway genes, which occur independently or synergistically, may lead to various complications during fetal development. Identification of multi-allele risk variants and epigenetic factors in women will be helpful in the identification of high-risk pregnancies.

PROSPERO REGISTRATION NUMBER

Prospero CRD42021287315.

Maternal, Fetal and Neonatal Outcomes Related to Recreational Cannabis Use during Pregnancy: Analysis of a Real-World Clinical Data Warehouse between 2010 and 2019

BACKGROUND

Cannabis is the main illicit psychoactive substance used in French childbearing women and very few data are available about adverse events (AEs) related to its use during pregnancy. The aim of this study was to evaluate the association between recreational cannabis use during pregnancy and adverse outcomes from a real-world clinical data warehouse.

METHODS

Data from the Poitiers University Hospital warehouse were analyzed between 1 January 2010 and 31 December 2019. Logistic regression models were used to evaluate associations between outcomes in three prenatal user groups: cannabis alone ± tobacco (C ± T) (n = 123), tobacco alone (T) (n = 191) and controls (CTRL) (n = 355).

RESULTS

Pregnant women in the C ± T group were younger (mean age: 25.5 ± 5.7 years), had lower pre-pregnancy body mass index (22.8 ± 5.5 kg/m2), more psychiatric history (17.5%) and were more likely to benefit from universal free health-care coverage (18.2%) than those in the T and CTRL groups. Cannabis use increases the occurrence of voluntary interruption of pregnancy, at least one AE during pregnancy, at least one neonatal AE, the composite adverse pregnancy outcome over 28, prematurity and small for gestational age.

CONCLUSION

Given the trivialization of recreational cannabis use during pregnancy, there is an urgent need to communicate on AEs of cannabis use during pregnancy.

Association of Vascular Endothelial Growth Factors (VEGFs) with Recurrent Miscarriage: A Systematic Review of the Literature

Recurrent miscarriage (RM) can be defined as two or more consecutive miscarriages before 20 weeks' gestation. Vascular endothelial growth factors (VEGFs) play an important role in endometrial angiogenesis and decidualization, prerequisites for successful pregnancy outcomes. We conducted a systematic review of the published literature investigating the role of VEGFs in RM. In particular, we explored the methodological inconsistencies between the published reports on this topic. To our knowledge, this is the first systematic literature review to examine the role of VEGFs in RM. Our systematic search followed PRISMA guidelines. Three databases, Medline (Ovid), PubMed, and Embase, were searched. Assessment-bias analyses were conducted using the Joanna Bigger Institute critical appraisal method for case-control studies. Thirteen papers were included in the final analyses. These studies included 677 cases with RM and 724 controls. Endometrial levels of VEGFs were consistently lower in RM cases compared to controls. There were no consistent significant findings with respect to VEGFs levels in decidua, fetoplacental tissues, and serum when RM cases were compared to controls. The interpretation of studies that explored the relationship between VEGFs and RM is hampered by inconsistencies in defining clinical, sampling, and analytical variables. To clarify the association between VEGF and RM in future studies, researchers ideally should use similarly defined clinical groups, similar samples collected in the same way, and laboratory analyses undertaken using the same methods.

Elevated Maternal Folate Status and Changes in Maternal Prolactin, Placental Lactogen and Placental Growth Hormone Following Folic Acid Food Fortification: Evidence from Two Prospective Pregnancy Cohorts

Folic acid (FA) food fortification in Australia has resulted in a higher-than-expected intake of FA during pregnancy. High FA intake is associated with increased insulin resistance and gestational diabetes. We aimed to establish whether maternal one-carbon metabolism and hormones that regulate glucose homeostasis change in healthy pregnancies post-FA food fortification. Circulating folate, B12, homocysteine, prolactin (PRL), human placental lactogen (hPL) and placental growth hormone (GH2) were measured in early pregnancy maternal blood in women with uncomplicated pregnancies prior to (SCOPE: N = 604) and post (STOP: N = 711)-FA food fortification. FA food fortification resulted in 63% higher maternal folate. STOP women had lower hPL (33%) and GH2 (43%) after 10 weeks of gestation, but they had higher PRL (29%) and hPL (28%) after 16 weeks. FA supplementation during pregnancy increased maternal folate and reduced homocysteine but only in the SCOPE group, and it was associated with 54% higher PRL in SCOPE but 28% lower PRL in STOP. FA food fortification increased maternal folate status, but supplements no longer had an effect, thereby calling into question their utility. An altered secretion of hormones that regulate glucose homeostasis in pregnancy could place women post-fortification at an increased risk of insulin resistance and gestational diabetes, particularly for older women and those with obesity.

The role of maternal choline, folate and one-carbon metabolism in mediating the impact of prenatal alcohol exposure on placental and fetal development

Prenatal alcohol consumption (PAE) may be associated with a broad spectrum of impacts, ranging from no overt effects, to miscarriage, fetal growth restriction and fetal alcohol spectrum disorder. A major mechanism underlying the effects of PAE is considered to be altered DNA methylation and gene expression. Maternal nutritional status may be an important factor in determining the extent to which PAE impacts pregnancy outcomes, particularly the dietary micronutrients folate and choline because they provide methyl groups for DNA methylation via one carbon metabolism. This review summarises the roles of folate and choline in development of the blastocyst, the placenta and the fetal brain, and examines the evidence that maternal intake of these micronutrients can modify the effects of PAE on development. Studies of folate or choline deficiency have found reduced blastocyst development and implantation, reduced placental invasion, vascularisation and nutrient transport capability, impaired fetal brain development, and abnormal neurodevelopmental outcomes. PAE has been shown to reduce absorption and/or metabolism of folate and choline and to produce similar outcomes to maternal choline/folate deficiency. A few studies have demonstrated that the effects of PAE on brain development can be ameliorated by folate or choline supplementation; however, there is very limited evidence on the effects of supplementation in early pregnancy on the blastocyst and placenta. Further studies are required to support these findings and to determine optimal supplementation parameters.

Biological Role of Folic Acid in Pregnancy and Possible Therapeutic Application for the Prevention of Preeclampsia

The rationale and importance of folic acid supplementation during pregnancy for fetal congenital defect prevention are accepted worldwide. Moreover, a sufficient plasma concentration of folates can reduce the incidence of spontaneous abortions, and support the normal expansion of placental blood vessels, ensuring physiological placental blood flow, thus promoting appropriate fetal growth and development. Furthermore, there is emerging evidence that long-term supplementation with folic acid can effectively prevent preeclampsia. Preeclampsia is unique to the human species in complications during pregnancy, which contributes to maternal and perinatal mortality worldwide. In the pathogenesis of preeclampsia abnormal placental invasion, the excess of antiangiogenic factors and maternal-placental syndrome play a key role. Increased blood levels of homocysteine during pregnancy are associated with the risk of preeclampsia. Moreover, hyperhomocysteinemia has been proposed to be an independent risk factor for preeclampsia. Folate supplementation helps to decrease elevated levels of homocysteine; thus, the role of folic acid supplementation in pregnancy is even more important. Multiple reports suggest that folate administration decreases the level of serum homocysteine and, therefore, reduce the risk and severity of preeclampsia. However, the association between folic acid supplementation and the decreased risk of preeclampsia has been investigated with controversial conclusions. Currently, the optimal dose of folic acid that is effective for preeclampsia prevention remains uncertain. In this review, we aim to summarize the accumulated knowledge on the role of folic acid in the pathogenesis of preeclampsia, and the possible impact of folate supplementation on the decreased risk of preeclampsia.

The impact of pre-pregnancy folic acid intake on placental DNA methylation in a fortified cohort

Folate plays an important role in the modulation of one-carbon metabolism and DNA methylation through a complex biosynthesis pathway. Folate deficiency during pregnancy has been associated with an increased risk for birth defects. This study investigates the extent to which the availability of folate and S-Adenosylmethionine (SAM) affects placental DNA methylation. We hypothesized that maintaining sufficient levels of folate and SAM is particularly important in individuals carrying the MTHFR C677T polymorphism. Maternal- and cord blood was analyzed to genotype the MTHFR rs1801133 SNP. Red blood cell (RBC) folate, vitamin B12, SAM, and S-Adenosylhomocysteine (SAH) were analyzed in cord blood. Epigenome-wide methylation analyses were performed on 90 placenta tissue samples isolated from the fetal side of the placenta; 45 originating from mother-infant dyads homozygous for the MTHFR C677T variant and 45 originating from mother-infant dyads with the homozygous wild type MTHFR677 genotype. Verification of the results was performed using pyrosequencing assays. Genome-wide placental DNA methylation patterns were relatively stable and not significantly affected by levels of one-carbon metabolites. MTHFR genotype was associated with DNA methylation of several loci, including a locus in the MTHFR region. RBC folate and particularly the SAM:SAH ratio did affect overall CpG DNA methylation in some CpG regions when the loci were split according to their CpG island relation. This was most evident in participants carrying the MTHFR C677T variant suggesting a stronger influence of the biosynthesis pathway on the overall placental DNA methylation in MTHFR TT individuals than in MTHFR CC individuals.

Folate in maternal rheumatoid arthritis-filial autism spectrum disorder continuum

Rheumatoid Arthritis (RA) is an inflammatory autoimmune disease that affects women three times more than men. Epidemiological studies found that the incidence of Autism Spectrum Disorder (ASD), a neurological and developmental disorder, in children born to mothers suffering from RA is higher compared with the control population. Considering that the pathogenesis of ASD could be traced back to pregnancy and in uterine conditions, and the evidence of reduced folate levels in the brain of ASD-affected children, we aimed to study the role of folate, as an important nutritional factor during pregnancy, in associating maternal RA to ASD development in the offspring. Folate balance during RA could be influenced twice, initially during the immune activation associated with disease onset, and later during the treatment with anti-folate drugs, with a potential consequence of folate deficiency. Maternal folate deficiency during pregnancy could increase homocysteine levels, oxidative stress, and global DNA hypomethylation, all known risk factors in ASD pathogenesis. These effects could be intensified by genetic polymorphisms in the folate system, which were also found as genetic risk factors for both RA and ASD. The available evidence suggests that folate level as an important factor during RA, pregnancy and ASD could have pathological and therapeutical significance and should be carefully monitored and investigated in the RA-pregnancy-ASD axis.

Profiling the Influence of Gene Variants Related to Folate-Mediated One-Carbon Metabolism on the Outcome of In Vitro Fertilization (IVF) with Donor Oocytes in Recipients Receiving Folic Acid Fortification

Nutritional status and gene polymorphisms of one-carbon metabolism confer a well-known interaction that in pregnant women may affect embryo viability and the health of the newborn. Folate metabolism directly impacts nucleotide synthesis and methylation, which is of increasing interest in the reproductive medicine field. Studies assessing the genetic influence of folate metabolism on IVF treatments have currently been performed in women using their own oocytes. Most of these patients seeking to have a child or undergoing IVF treatments are advised to preventively intake folate supplies that restore known metabolic imbalances, but the treatments could lead to the promotion of specific enzymes in specific women, depending on their genetic variance. In the present study, we assess the influence of candidate gene variants related to folate metabolism, such as Serine Hydroxymethyltransferase 1 SHMT1 (rs1979276 and rs1979277), Betaine-Homocysteine S-Methyltransferase BHMT (rs3733890), Methionine synthase reductase MTRR (rs1801394), Methylenetetrahydrofolate reductase MTHFR (rs1801131 and rs1801133), methionine synthase MTR (rs12749581), ATP Binding Cassette Subfamily B Member 1 ABCB1 (rs1045642) and folate receptor alpha FOLR1 (rs2071010) on the success of IVF treatment performed in women being recipients of donated oocytes. The implication of such gene variants seems to have no direct impact on pregnancy consecution after IVF; however, several gene variants could influence pregnancy loss events or pregnancy maintenance, as consequence of folic acid fortification.

Correlation between crown-rump length in the first trimester of pregnancy and neonatal outcomes

BACKGROUND

To investigate the association of crown-rump length (CRL) during the first trimester of pregnancy with neonatal outcomes.

METHODS

A total of 15,524 women with a reliable first day of the last menstrual period and a regular menstrual cycle (28 ± 4 days) were included from January 2015 to November 2016. CRL was measured by ultrasound from 7⁺⁰ to 13⁺⁶ weeks during pregnancy and transformed to a standard deviation score (SDS) adjusted for gestational age. Linear regression was used to explore risk factors for CRL. A generalised linear model was used to evaluate the association between CRL and neonatal outcomes.

RESULTS

In the multivariate analysis, maternal age (0.25 mm, 95% CI = [0.22-0.28], P < 0.001; 0.04 SDS, 95% CI = [0.03-0.04], P < 0.001), multipara (0.30 mm, 95% CI = [0.08-0.52], P = 0.007; 0.04 SDS, 95% CI = [0.00-0.07], P = 0.031) and folic acid supplement use (0.78 mm, 95% CI = [0.49-1.08], P < 0.001; 0.05 SDS, 95% CI = [0.01-0.10], P < 0.019) were positively associated with CRL, while pre-pregnancy BMI (-0.17 mm, 95% CI = [-0.21 to -0.13], P < 0.001; -0.02 SDS, 95% CI = [-0.03 to -0.02], P < 0.001) was negatively related to CRL. For neonatal outcomes, CRL was negatively associated with small for gestational age (SGA) ([risk ratio] (RR) = 0.733, 95% [CI] = 0.673-0.8004, P_adjusted < 0.001) and neonatal intensive care unit (NICU) admission ([RR] = 0.928, 95% [CI] = 0.883-0.976, P_adjusted = 0.003), and preterm birth ([RR] = 1.082, 95% [CI] = 1.008-1.162, P_adjusted = 0.029), but positively related to large for gestational age (LGA) ([RR] = 1.241, 95% [CI] = 1.184-1.301, P_adjusted = 0.012). When stratified by pre-pregnancy BMI, the risk of SGA and LGA remained significant in all groups, while the increased risk of preterm birth was only observed in the lean group (BMI < 18.5 kg/m²) and decreased risk of NICU admission rate in the normal group (BMI 18.5-24 kg/m²).

CONCLUSIONS

Maternal characteristics were independently associated with CRL in the first trimester, which was negatively related to foetal size, SGA, preterm birth, and admission rate to the NICU, but positively related to LGA.

Role of osteopontin (OPN) in uterine spiral artery remodeling

Uterine spiral artery (SpA) remodeling is critical for a successful pregnancy. The deficiency of SpA remodeling seriously affects the blood perfusion of the placenta, impacting the nutritional supply to the fetus and therefore fetal growth and development, which is one of the pathological causes of pregnancy related diseases. This process involves the interaction between all cells and related factors at the maternal-fetal interface, especially extravillous trophoblast cells (EVT), vascular smooth muscle cells (VSMCs) and decidual immune cells. Osteopontin (OPN), as a glycosylated protein, is widely localized in the extracellular matrix and participates in a variety of cellular activities such as migration, adhesion, differentiation and survival. OPN plays an important role in placental development, uterine decidualization and pregnancy success. This study focuses on the role of OPN in uterine spiral artery remodeling and its related molecular mechanism.

Folic Acid Levels During Pregnancy Regulate Trophoblast Invasive Behavior and the Possible Development of Preeclampsia

Background

One of the unique features of placentation is its similarity to tumorigenesis yet being very well regulated. It allows rapid proliferation, migration, and invasion of mononuclear trophoblast cells into the maternal uterus and remodeling the maternal vasculature. This pseudomalignant nature of trophoblastic cells is strictly regulated and its importance becomes evident in abnormal pregnancies that are characterized by aberrant trophoblast proliferation/invasion like preeclampsia. In addition to this, the importance of folic acid supplementation during pregnancy is well documented. We aimed to analyze the molecular and epigenetic regulation of the pseudomalignant nature of placentation via folic acid levels.

Methods

Placental tissue samples were collected from different pregnancies in three different gestational stages. We estimated the impact of folic acid levels on global methylation, LINE1 methylation, and expression of DNMTs in all three gestational stages in pregnant women and preeclampsia pregnancies. We also analyzed the effect of folic acid supplementation on trophoblastic invasion using placental derived cells viz, JEG-3 and HTR-8/SVneo cell line and verified the molecular and epigenetic mechanisms involved in this regulation.

Results

Development of preeclampsia was observed to be associated with lower folate levels in placental tissue, higher global methylation level, and higher expression of DNMT1and DNMT3A. Folic acid supplementation was found to increase the invasive potential of placental trophoblasts by almost two folds which were associated with the decreased expression of tumor suppressor genes and tissue inhibitors of matrix metalloproteinases; and increased expression of oncogenes, telomerase gene, and matrix metalloproteinases. These folic acid-mediated changes were observed to be regulated by CpG methylation in the case of many genes. Folic acid supplementation was also observed to significantly decrease global methylation in placental trophoblasts related to decreasing expression of DNMT1 and DNMT3A.

Conclusion

Lower folic acid levels are associated with preeclampsia development and folic acid supplementation regulates the invasive potential of placental trophoblasts as mediated by various epigenetic changes in the placenta suggesting the protective effect of folic acid against preeclampsia.

Folinic Acid Potentiates the Liver Regeneration Process after Selective Portal Vein Ligation in Rats

Simple Summary

Fewer than 30% of patients with liver metastases are eligible for major liver resection, because liver remaining after such a surgery would be insufficient to cover the patient’s needs; this is called a low percentage of future liver remnant (FLR). Folinic acid (FA) has been shown to play a crucial role in cellular synthesis, regeneration, and nucleotide and amino acid biosynthesis. The aim of this piece of research was to evaluate the effect of FA as a potential hypertrophic hepatic enhancer agent after selective portal vein ligation (PVL) to ensure adequate FLR. We have confirmed in our rodent model that FA accelerates liver regeneration after PVL and enhances recovery of liver function. These findings may allow more patients to be eligible for liver resection without jeopardizing postoperative liver function.

Abstract

Liver resection remains the gold standard for hepatic metastases. The future liver remnant (FLR) and its functional status are two key points to consider before performing major liver resections, since patients with less than 25% FLR or a Child–Pugh B or C grade are not eligible for this procedure. Folinic acid (FA) is an essential agent in cell replication processes. Herein, we analyze the effect of FA as an enhancer of liver regeneration after selective portal vein ligation (PVL). Sixty-four male WAG/RijHsd rats were randomly distributed into eight groups: a control group and seven subjected to 50% PVL, by ligation of left portal branch. The treated animals received FA (2.5 m/kg), while the rest were given saline. After 36 h, 3 days or 7 days, liver tissue and blood samples were obtained. FA slightly but significantly increased FLR percentage (FLR%) on the 7th day (91.88 ± 0.61%) compared to control or saline-treated groups (86.72 ± 2.5 vs. 87 ± 3.33%; p < 0.01). The hepatocyte nuclear area was also increased both at 36 h and 7days with FA (61.55 ± 16.09 µm², and 49.91 ± 15.38 µm²; p < 0.001). Finally, FA also improved liver function. In conclusion, FA has boosted liver regeneration assessed by FLR%, nuclear area size and restoration of liver function after PVL.

Preeclampsia: From Cellular Wellness to Inappropriate Cell Death, and the Roles of Nutrition

Preeclampsia is one of the most common obstetrical complications worldwide. The pathomechanism of this disease begins with abnormal placentation in early pregnancy, which is associated with inappropriate decidualization, vasculogenesis, angiogenesis, and spiral artery remodeling, leading to endothelial dysfunction. In these processes, appropriate cellular deaths have been proposed to play a pivotal role, including apoptosis and autophagy. The proper functioning of these physiological cell deaths for placentation depends on the wellbeing of the trophoblasts, affected by the structural and functional integrity of each cellular component including the cell membrane, mitochondria, endoplasmic reticulum, genetics, and epigenetics. This cellular wellness, which includes optimal cellular integrity and function, is heavily influenced by nutritional adequacy. In contrast, nutritional deficiencies may result in the alteration of plasma membrane, mitochondrial dysfunction, endoplasmic reticulum stress, and changes in gene expression, DNA methylation, and miRNA expression, as well as weakened defense against environmental contaminants, hence inducing a series of inappropriate cellular deaths such as abnormal apoptosis and necrosis, and autophagy dysfunction and resulting in abnormal trophoblast invasion. Despite their inherent connection, the currently available studies examined the functions of each organelle, the cellular death mechanisms and the nutrition involved, both physiologically in the placenta and in preeclampsia, separately. Therefore, this review aims to comprehensively discuss the relationship between each organelle in maintaining the physiological cell death mechanisms and the nutrition involved, and the interconnection between the disruptions in the cellular organelles and inappropriate cell death mechanisms, resulting in poor trophoblast invasion and differentiation, as seen in preeclampsia.

Maternal Dietary Quality and Dietary Inflammation Associations with Offspring Growth, Placental Development, and DNA Methylation

The ‘Developmental Origins of Health and Diseases’ hypothesis posits that prenatal maternal diet influences offspring growth and later life health outcomes. Dietary assessment has focused on selected nutrients. However, this approach does not consider the complex interactions between foods and nutrients. To provide a more comprehensive approach to public health, dietary indices have been developed to assess dietary quality, dietary inflammation and risk factors for non-communicable diseases. Thus far, their use in the context of placental development is limited and associations with offspring outcomes have been inconsistent. Although epidemiological studies have focused on the role of maternal diet on foetal programming, the underlying mechanisms are still poorly understood. Some evidence suggests these associations may be driven by placental and epigenetic changes. In this narrative review, we examine the current literature regarding relationships between key validated diet quality scores (Dietary Inflammatory Index [DII], Mediterranean diet [MD], Healthy Eating Index [HEI], Alternative Healthy Eating Index [AHEI], Dietary Approaches to Stop Hypertension [DASH], Glycaemic Index [GI] and Glycaemic Load [GL]) in pregnancy and birth and long-term offspring outcomes. We summarise findings, discuss potential underlying placental and epigenetic mechanisms, in particular DNA methylation, and highlight the need for further research and public health strategies that incorporate diet quality and epigenetics.

First trimester mechanisms of gestational sac placental and foetal teratogenicity: a framework for birth cohort studies

BACKGROUND

The function of the gestational sac (GS) and the placenta in the closely related processes of embryogenesis and teratogenicity in the first trimester has been minimally described. The prevailing assumption is that direct teratogenic effects are mediated by the critical extraembryonic organ, the placenta, which either blocks or transfers exposures to the foetus. Placental transfer is a dominant mechanism, but there are other paradigms by which the placenta can mediate teratogenic effects. Knowledge of these paradigms and first trimester human developmental biology can be useful to the epidemiologist in the conduct of biomarker-based studies of both maternal and child health.

OBJECTIVE AND RATIONALE

Our aim is to provide a causal framework for modelling the teratogenic effects of first trimester exposures on child health outcomes mediated by the GS and placenta using biomarker data collected in the first trimester. We initially present first trimester human developmental biology for the sake of informing and strengthening epidemiologic approaches. We then propose analytic approaches of modelling placental mechanisms by way of causal diagrams using classical non-embryolethal teratogens (diethylstilboestrol [DES], folic acid deficiency and cytomegalovirus [CMV]) as illustrative examples. We extend this framework to two chronic exposures of particular current interest, phthalates and maternal adiposity.

SEARCH METHODS

Information on teratogens was identified by a non-systematic, narrative review. For each teratogen, we included papers that answered the five following questions: (i) why were these exposures declared teratogens? (ii) is there a consensus on biologic mechanism? (iii) is there reported evidence of a placental mechanism? (iv) can we construct a theoretical model of a placental mechanism? and (v) can this knowledge inform future work on measurement and modelling of placental-foetal teratogenesis? We prioritized literature specific to human development, the organogenesis window in the first trimester and non-embryolethal mechanisms.

OUTCOMES

As a result of our review of the literature on five exposures considered harmful in the first trimester, we developed four analytic strategies to address first trimester placental mechanisms in birth cohort studies: placental transfer and direct effects on the foetus (DES and maternal adiposity), indirect effects through targeted placental molecular pathways (DES and phthalates), pre-placental effects through disruptions in embryonic and extraembryonic tissue layer differentiation (folic acid deficiency), and multi-step mechanisms that involve maternal, placental and foetal immune function and inflammation (DES and CMV).

WIDER IMPLICATIONS

The significance of this review is to offer a causal approach to classify the large number of potentially harmful exposures in pregnancy when the exposure occurs in the first trimester. Our review will facilitate future research by advancing knowledge of the first trimester mechanisms necessary for researchers to effectively associate environmental exposures with child health outcomes.

A narrative review on the role of folate-mediated one-carbon metabolism and its associated gene polymorphisms in posing risk to preeclampsia

Preeclampsia (PE) presents a major obstetrical problem for mother and fetus which is characterized by the onset of hypertension and proteinuria in formerly normotensive women. Altered folate-mediated one-carbon metabolism is one of the factors for PE development either due to nutritional insufficiencies such as folate deficiency or polymorphisms in genes that code for the key enzymes of the cycle. Commonly, there are four genes in the cycle whose polymorphisms have been described in relation to PE. These factors could cause elevation of homocysteine; the toxic metabolite, which subsequently leads to the development of PE. Sufficient levels of folate have been considered important during pregnancy and may reduce the risk of development of PE. This review aims at discussing genetic polymorphisms and nutritional deficiencies as probable predisposing factors and suggests considering fetal genotypes, varied ethnicities, and interaction of various other factors involved to render better conclusiveness to the present studies.

High maternal folic acid intake around conception alters mouse blastocyst lineage allocation and expression of key developmental regulatory genes

Folate, a cofactor for the supply of one-carbon groups, is required by epigenetic processes to regulate cell lineage determination during development. The intake of folic acid (FA), the synthetic form of folate, has increased significantly over the past decade, but the effects of high periconceptional FA intake on cell lineage determination in the early embryo remains unknown. Here, we investigated the effect of maternal high FA (HFA) intake on blastocyst development and expression of key regulatory genes. C57BL/6 adult female mice were fed either Control diet (1 mg FA) for 4 weeks before conception and during the preimplantation period (Con-Con); Control diet for 4 weeks preconception, followed by HFA (5 mg FA) diet during preimplantation (Con-HFA); or HFA diet for 4 weeks preconception and during preimplantation (HFA-HFA). At E3.5, blastocyst cell number, protein, and mRNA expression were measured. In HFA-HFA blastocysts, trophectoderm cell numbers and expression of CDX2, Oct-4, and Nanog were reduced compared with Con-Con blastocysts; Con-HFA blastocysts showed lower CDX2 and Oct-4 expression than Con-Con blastocysts. These findings suggest periconceptional HFA intake induces changes in key regulators of embryo morphogenesis with potential implications for subsequent development.

A 3-dimensional microfluidic platform for modeling human extravillous trophoblast invasion and toxicological screening

Placental trophoblast cells invasion into the maternal uterus is an essential and complex event in the formation of the maternal-fetal interface. Commonly used two-dimensional (2D) cell invasion tools do not accurately represent the in vivo cell invasion microenvironment. Three-dimensional (3D) silicone polymer polydimethylsiloxane (PDMS) microfluidic platforms are an emerging technology in developing organ-on-a-chip models. Here, we present a placenta-on-a-chip platform that enables the evaluation of trophoblast invasion with intraluminal flow within an engineered PDMS 3D microfluidic chip. This platform reproduces key elements of the placental microenvironment, including endothelial and trophoblast cells, layered with an extracellular matrix, and incorporates dynamic medium flow while allowing for real-time monitoring, imaging, evaluation of trophoblast cell invasion, and heterocellular cell-to-cell interactions. Coupled with fluorescent cell tagging and flow cytometry, this platform also allows collection of the invasive cells. This will help our understanding of pathways that regulate trophoblast cell invasion and may prove important for toxicological screening of exposures that interfere with invasiveness in a complex organ such as the placenta.

Maternal exposure to sulfonamides and adverse pregnancy outcomes: A systematic review and meta-analysis

Background

Sulfonamides are widely used to treat infectious diseases during pregnancy. However, the safety of maternal exposure to sulfonamides is controversial. This study aims to systematically review the available studies and examine the effect of maternal sulfonamides use on adverse pregnancy outcomes.

Methods

We searched PubMed, Science Direct, Web of Science, ClinicalTrials.gov, CNKI and Wanfang Database (in Chinese). The meta-analysis used random effects model or fixed effects model to obtain the total odds ratio (OR) for each outcome through Stata11.0 software. Study on the relationship between sulfonamide exposure during pregnancy and adverse pregnancy outcomes. The study design covered randomized controlled trials, cohort studies and case-control studies. The study protocol was registered in PROSPERO with protocol number CRD42020178687.

Results

A total of 10 studies, and 1096350 participants were included for systematic review. Maternal exposure to sulfonamides was found to be possibly associated with increased risk of congenital malformations (OR = 1.21, 95% CI 1.07–1.37). The use of sulfonamides in the first trimester of pregnancy and during the entire pregnancy might be associated with congenital malformations.

Conclusions

Maternal exposure to sulfonamides may be associated with offspring’ s congenital malformations. Prescription of sulfonamides for pregnant women is suggested to be carefully censored.

Maternal Docosahexaenoic Acid Status during Pregnancy and Its Impact on Infant Neurodevelopment

Dietary components are essential for the structural and functional development of the brain. Among these, docosahexaenoic acid, 22:6n-3 (DHA), is critically necessary for the structure and development of the growing fetal brain in utero. DHA is the major n-3 long-chain polyunsaturated fatty acid in brain gray matter representing about 15% of all fatty acids in the human frontal cortex. DHA affects neurogenesis, neurotransmitter, synaptic plasticity and transmission, and signal transduction in the brain. Data from human and animal studies suggest that adequate levels of DHA in neural membranes are required for maturation of cortical astrocyte, neurovascular coupling, and glucose uptake and metabolism. Besides, some metabolites of DHA protect from oxidative tissue injury and stress in the brain. A low DHA level in the brain results in behavioral changes and is associated with learning difficulties and dementia. In humans, the third trimester-placental supply of maternal DHA to the growing fetus is critically important as the growing brain obligatory requires DHA during this window period. Besides, DHA is also involved in the early placentation process, essential for placental development. This underscores the importance of maternal intake of DHA for the structural and functional development of the brain. This review describes DHA’s multiple roles during gestation, lactation, and the consequences of its lower intake during pregnancy and postnatally on the 2019 brain development and function.

Folic acid supplementation is associated with size at birth in the Screening for Pregnancy Endpoints (SCOPE) international prospective cohort study

BACKGROUND

Small-for-gestational-age (SGA) is a significant cause of morbidity and mortality, and there are currently few preventive strategies.

AIM

The aim of this study was to investigate the relationship between maternal folic acid supplement (FAS) use pre-conception through to the second trimester, and small-for-gestational age (SGA) and birth size parameters.

STUDY DESIGN

Women were recruited as part of the Screening for Pregnancy Endpoints (SCOPE) international prospective multi-centre cohort study: New Zealand, Australia, United Kingdom and Ireland. Information on FAS use pre-conception, during the first trimester and at 15 ± 1 weeks' gestation was collected via interview administered questionnaire. Participants were followed through to delivery. Pregnancy outcome data and birth measurements were collected within 72 h of birth. Multivariable regression analysis was used to investigate relationships between FAS and outcomes, adjusting for maternal sociodemographic and lifestyle factors.

SUBJECTS

Nulliparous women with singleton pregnancies.

OUTCOME MEASURES

SGA (<10th customised birthweight centile).

RESULTS

5606 women were included. SGA prevalence was 11.3%. Pre-conception FAS was associated with a significantly lower risk of SGA: aOR = 0.82 (95% CI: 0.67-01.00 p = 0.047). Although the association between FAS at 15 weeks' gestation and SGA did not reach significance, FAS at 15 weeks was associated with a significantly higher customised birthweight centile (β 2.56 (95% CI: 0.87-4.26; p = 0.003). There was no significant effect of FAS on large-for-gestational-age births or head circumference.

CONCLUSIONS

In this international cohort, FAS was positively associated with fetal growth, without increasing risks associated with LGA. Further studies are required to confirm whether continuing FAS beyond the first trimester might lower the risk of SGA.

Folic acid versus 5- methyl tetrahydrofolate supplementation in pregnancy

Folate (vitamin B9) is widely accepted to protect against fetal neural tube defects. The main sources of dietary folate are folic acid-fortified foods and folic acid-containing dietary supplements. However, folic acid is inactive in the human body and must be converted by the liver into the active molecule 5-methyltetrahydrofolate (5-MTHF). 5-MTHF functions as a methyl donor in many metabolic reactions, including the conversion of homocysteine into methionine, the biosynthesis of glycine from serine, and the biosynthesis of DNA precursor molecules. Therefore, folate is fundamental for growth, especially in the embryonic and fetal stages. Prescription of folic acid to women in the preconception period and during pregnancy is a consolidated practice. However, it can pose health risks in certain conditions, such as megaloblastic anemia, where it will conceal megaloblastic anemia due to vitamin B12 deficiency and in cases of reduced hepatic transformation of folic acid (e.g. due to genetic variants or during some pharmacotherapies). Some of these risks can be avoided by supplementation with 5-MTHF rather than folic acid. Because 5-MTHF does not require activation, it is immediately available to mother and fetus and does not accumulate in blood like folic acid does in cases of reduced hepatic transformation. This paper reviews the advantages and disadvantages of folate supplementation with folic acid versus 5-MTHF, with a focus on maternal and fetal health.

Endometrial Decidualization: The Primary Driver of Pregnancy Health

Interventions to prevent pregnancy complications have been largely unsuccessful. We suggest this is because the foundation for a healthy pregnancy is laid prior to the establishment of the pregnancy at the time of endometrial decidualization. Humans are one of only a few mammalian viviparous species in which decidualization begins during the latter half of each menstrual cycle and is therefore independent of the conceptus. Failure to adequately prepare (decidualize) the endometrium hormonally, biochemically, and immunologically in anticipation of the approaching blastocyst—including the downregulation of genes involved in the pro- inflammatory response and resisting tissue invasion along with the increased expression of genes that promote angiogenesis, foster immune tolerance, and facilitate tissue invasion—leads to abnormal implantation/placentation and ultimately to adverse pregnancy outcome. We hypothesize, therefore, that the primary driver of pregnancy health is the quality of the soil, not the seed.

The Effect of Interactions between Folic Acid Supplementation and One Carbon Metabolism Gene Variants on Small-for-Gestational-Age Births in the Screening for Pregnancy Endpoints (SCOPE) Cohort Study

Small-for-gestational-age (SGA) is associated with significant perinatal morbidity and mortality. Our aim was to investigate gene-nutrient interactions between maternal one-carbon single nucleotide polymorphisms (SNPs) and folic acid supplement (FAS) use, and their association with SGA. Nulliparous New Zealand women with singleton pregnancy were recruited as part of the Screening for Pregnancy Endpoints prospective cohort study. Data on FAS use was collected via face-to-face interview at 15 weeks’ gestation; participants were followed prospectively and birth outcome data collected within 72 h of delivery. Participants were genotyped for MTHFR 677, MTHFR 1298, MTHFD1 1958, MTR 2756, MTRR 66 and TCN2 776 SNPs. Genotype data for at least one SNP was available for 1873 (93%) of eligible participants. Analysis showed a significant SNP-FAS interaction for MTHFR 1298 (p = 0.020), MTHFR 677 (p = 0.019) and TCN2 776 (p = 0.017) in relation to SGA: MTHFR 1298 CC variant non-FAS users had an increased likelihood [Odds Ratio (OR) = 2.91 (95% Confidence Interval (CI) = 1.52, 5.60] compared with wild-type (MTHFR 1298 AA) FAS users. MTHFR 677 variant allele carrier (MTHFR 677 CT + MTHFR 677 TT) non-FAS users had an increased likelihood [OR = 1.87 (95% CI = 1.21, 2.88)] compared to wild-type (MTHFR 677 CC) FAS users. TCN2 776 variant (TCN2 776 GG) non-FAS users had an increased likelihood [OR = 2.16 (95% CI = 1.26, 3.71)] compared with wild type homozygote + heterozygote (TCN2 776 CC + TCN2 776 CG) FAS users. No significant interactions were observed for MTHFD1 1958, MTR 2756 or MTRR 66 (p > 0.05). We observed an overall pattern of FAS attenuating differences in the likelihood of SGA seen between genotype groups in FAS non-users. Future research should focus on how intake of other one-carbon nutrients might mediate these gene-nutrient interactions.

Autophagy regulates abnormal placentation induced by folate deficiency in mice

Folate deficiency has been linked to a wide range of pregnancy disorders. Most research about folate-deficiency has focused on the embryo itself, little attention has been paid to possible effects on the placenta. According to our results, the morphology of the placenta, endocrine function, and the expression of genes involved in placental differentiation were all abnormal in folate-deficient mice on days 10, 12, and 14 of pregnancy. Similar results were found in human placenta explants cultured in folate-deficient medium. Autophagy is an inducible catabolic process activated by external nutrients starvation. Here we explored further, whether autophagy was involved in the abnormal placentation caused by folate-deficiency. The aberrant number of autophagosomes measured by transmission electron microscopy and the deviant expression of autophagy-related markers showed a disordered autophagy in placentas under conditions of folate-deficiency in vivo and in vitro dual-fluorescence mRFP-eGFP-LC3 analysis indicated enhanced autophagy was detected in HTR8/SVneo cells incubated in folate-deficient medium. Importantly, the placentation impairment in mice and human placenta explants could be recovered by inhibiting placental autophagy using 3-MA. In addition, the apoptosis and invasive capability of HTR8/SVneo cells were obviously suppressed by folate deficiency but notably elevated by 3-MA. These data suggest that folate deficiency can impair placentation and autophagy is a key factor in this. However, the signal pathway by which folate deficiency causes aberrant autophagy needs to be explored further.

Preventive effects of folic acid on Zika virus-associated poor pregnancy outcomes in immunocompromised mice

Zika virus (ZIKV) infection may lead to congenital microcephaly and pregnancy loss in pregnant women. In the context of pregnancy, folic acid (FA) supplementation may reduce the risk of abnormal pregnancy outcomes. Intriguingly, FA may have a beneficial effect on the adverse pregnancy outcomes associated with ZIKV infection. Here, we show that FA inhibits ZIKV replication in human umbilical vein endothelial cells (HUVECs) and a cell culture model of blood-placental barrier (BPB). The inhibitory effect of FA against ZIKV infection is associated with FRα-AMPK signaling. Furthermore, treatment with FA reduces pathological features in the placenta, number of fetal resorptions, and stillbirths in two mouse models of in utero ZIKV transmission. Mice with FA treatment showed lower viral burden and better prognostic profiles in the placenta including reduced inflammatory response, and enhanced integrity of BPB. Overall, our findings suggest the preventive role of FA supplementation in ZIKV-associated abnormal pregnancy and warrant nutritional surveillance to evaluate maternal FA status in areas with active ZIKV transmission.

Association between serum homocysteine level and unexplained infertility in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI): A retrospective, hospital-based, case-control study

Background

Lower serum homocysteine (Hcy) levels are found to correlate with a better chance of clinical pregnancy and better embryo grades in assisted reproductive technology (ART). However, there is little knowledge on the association between Hcy level and unexplained infertility until now.

Methods

A total of 388 infertile women undergoing IVF/ICSI treatments were recruited, including 129 women with unexplained causes (case group) and 259 women with known causes (control group), and the case group was further divided into subgroups A (≤8 μmol/L), B (>8 and <15 μmol/L), and C (≥15 μmol/L) based on the serum Hcy level. The associations between serum Hcy level and IVF/ICSI pregnancy outcomes were examined in infertile women with unknown causes.

Results

A significantly higher serum Hcy level was measured in the case group than in the control group (P = .008). Subgroup analysis revealed a significant difference in the total number of oocytes retrieved among subgroups A, B, and C (P = .031), and no significant difference was seen among these three groups in terms of age, BMI, E₂ level on the hCG day, number of M‐II oocytes, number of fertilized oocytes, or total number of high‐quality embryos (P > .05). Spearman correlation analysis revealed a negative correlation between serum Hcy level and total number of oocytes retrieved (r = −.406, P = .019). Univariate and multivariate linear regression analyses revealed that serum Hcy level had no correlations with any IVF/ICSI outcomes.

Conclusion

Serum Hcy level has no associations with IVF/ICSI pregnancy outcomes.

Association between expression of long noncoding RNAs in placenta and pregnancy features

Aim: The contribution of long noncoding RNAs (lncRNAs) has been highlighted in a variety of human disorders including cancer and placenta-associated conditions. Methods: We evaluated expression of CCAT2, UCA1, FAS-AS1 and OIP5-AS1 lncRNAs in placenta samples obtained from normal and intrauterine growth restriction pregnancies. Results: There was no significant difference in expression of these lncRNAs between cases and controls. A significant association was found between CCAT2 expression and gravidity/parity. CCAT2 expression was higher in cases with abortion history. Cases who received folic acid had lower expression of this lncRNA. Conclusion: The current study provides evidences for association between expression of CCAT2 and clinical determinants of placenta function. Future studies are needed to elaborate the underlying mechanism.

Association Between Maternal Exposure to Lead, Maternal Folate Status, and Intergenerational Risk of Childhood Overweight and Obesity

IMPORTANCE

The first pediatric lead screening typically occurs at 1-year well-child care visits. However, data on the extent of maternal lead exposure and its long-term consequences for child health are lacking.

OBJECTIVE

To investigate the associations between maternal red blood cell (RBC) lead levels and intergenerational risk of overweight or obesity (OWO) and whether adequate maternal folate status is associated with a reduction in OWO risk.

DESIGN, SETTING, AND PARTICIPANTS

Prospective birth cohort study. The analysis was conducted from July 14, 2018, to August 2, 2019, at Johns Hopkins Bloomberg School of Public Health. This study included 1442 mother-child pairs recruited at birth from October 27, 2002, to October 10, 2013, and followed up prospectively at Boston Medical Center.

MAIN OUTCOMES AND MEASURES

Child body mass index (BMI) z score, calculated according to US national reference data, and OWO, defined as BMI at or exceeding the 85th percentile for age and sex. Maternal RBC lead levels and plasma folate levels were measured in samples obtained 24 to 72 hours after delivery; child whole-blood lead level was obtained from the first pediatric lead screening.

RESULTS

The mean (SD) age of mothers and children was 28.6 (6.5) years and 8.1 (3.1) years, respectively; 50.1% of children were boys. The median maternal RBC lead level and plasma folate level were 2.5 (interquartile range [IQR], 1.7-3.8) μg/dL and 32.2 (IQR, 22.1-44.4) nmol/L, respectively. The median child whole-blood lead level and child BMI z score were 1.4 (IQR, 1.4-2.0) μg/dL and 0.78 (IQR, -0.08 to 1.71), respectively. Maternal RBC lead level was associated with child OWO risk in a dose-response fashion, with an odds ratio (OR) of 1.65 (95% CI, 1.18-2.32) for high maternal RBC lead level (≥5.0 μg/dL) compared with low maternal RBC lead level (<2.0 μg/dL). Child OWO was highest among children of OWO mothers with high RBC lead levels (adjusted OR, 4.24; 95% CI, 2.64-6.82) compared with children of non-OWO mothers with low RBC lead levels. Children of OWO mothers with high RBC lead levels had 41% lower OWO risk (OR, 0.59; 95% CI, 0.36-0.95; P = .03) if their mothers had adequate plasma folate levels (≥20.4 nmol/L) compared with their counterparts.

CONCLUSIONS AND RELEVANCE

In this sample of a US urban population, findings suggest that maternal elevated lead exposure was associated with increased risk of intergenerational OWO independent of postnatal blood lead levels. Adequate maternal folate status appeared to be associated with lower OWO risk. If confirmed by additional studies, these findings have implications for prenatal lead screening and management to minimize adverse health consequences on children.

Paternal preconception folate intake in relation to gestational age at delivery and birthweight of newborns conceived through assisted reproduction

RESEARCH QUESTION

Studies in rodents have shown that paternal folate intake prior to conception is associated with pregnancy and offspring outcomes. The aim of this study was to assess whether those associations might apply to humans as well.

DESIGN

Between 2007 and 2017, the study prospectively analysed data from 108 couples participating in a preconception cohort of couples undergoing fertility treatment using their own gametes, whose treatment resulted in 113 pregnancies during the course of the study. Paternal and maternal preconception folate intake was assessed using a validated food frequency questionnaire. Linear mixed models were used to assess whether paternal preconception folate intake was associated with gestational age at delivery and gestational age-specific birthweight, while accounting for correlated data and potential confounders.

RESULTS

In a multivariable-adjusted model, a 400 μg/day increase in preconception paternal folate intake was associated with a 2.6-day longer gestation (95% confidence interval 0.8-4.3) after adjusting for potential confounders, including maternal folate intake. Similar associations were found for folate from food and supplements. Maternal folate intake was not associated with gestational age at delivery. Neither paternal nor maternal folate intake was associated with gestational-age-specific birthweight.

CONCLUSIONS

Higher paternal preconception folate intake was associated with slightly longer gestation among live births achieved through assisted reproduction. The results suggest that preconception exposures of the father may have an impact on the health of his offspring, and therefore that preconception care should shift from a woman-centric to a couple-based approach.

Fetal programming and Wilms tumor

BACKGROUND

The "fetal programming" hypothesis has been evaluated in many adult diseases including cancer, but not for Wilms tumor. Wilms tumor has been related to high birthweight, but little is known about other growth metrics such as a baby's birth length, ponderal index, or placenta size, which can shed additional light on growth patterns.

METHODS

Cases of Wilms tumor (N = 217) were taken from the Danish Cancer Registry, and controls (N = 4340) were randomly selected from the Population Register and matched to cases by sex and age. Linkage to the Medical Births Registry provided information on gestational factors and fetal growth measurements, while linkage to the Patient Register provided information on maternal and child health conditions.

RESULTS

Despite having typically normal to higher birthweights, Wilms tumor cases had smaller placentas (≤540 g; odds ratio (OR) = 4.24; 95% confidence interval (CI), 1.84-9.78) and a lower placenta-to-birthweight ratio (OR = 1.81; 95% CI, 1.17-2.82, per 1 SD decrease). Small placentas were more common among Wilms cases without congenital anomalies (OR = 6.43; 95% CI, 1.95-21.21). Wilms tumor cases had a higher prevalence of high birthweight (>4000 g; OR = 1.57; 95% CI, 1.11-2.22), birth length 55 cm or longer (OR = 1.74; 95% CI, 1.09-2.78), and being large for gestational age (OR = 1.79; 95% CI, 1.08-2.96).

CONCLUSIONS

Our study corroborates earlier studies showing associations with high birthweight and suggests associations between Wilms tumor and decreased placental size and low placenta-to-birthweight ratio.

Effects of EBN on embryo implantation, plasma concentrations of reproductive hormones, and uterine expressions of genes of PCNA, steroids, growth factors and their receptors in rats

This study was conducted to determine the effect of edible bird's nest (EBN) supplement on uterine function and embryo-implantation rate. A total of 24 adult female rats, divided equally into four groups, were treated with different doses of EBN for 8 weeks. In the last week of treatment, intact fertile male rats were introduced into each group (three per group) for overnight for mating. On day 7 post-mating (post-implantation), blood samples were collected from the hearts of anaesthetised rats that were later sacrificed. The uteri were removed for assessment of embryo implantation rate, histological and electron microscopic examination, and immunohistochemical analyses. Results showed that as the concentration of EBN supplemented increased, the pregnancy and embryo implantation rates were also increased in the treated groups; significantly at G3 and G4. Although histological evaluation did not show much difference among the groups, scanning electron microscopic examination showed enhanced development of elongated microvilli and pinopods in G4. Results also revealed up-regulated expressions of epidermal growth factor (EGF), EGF receptor (EGFR), vascular endothelial growth factor (VEGF), proliferating cell nulear antigen (PCNA), and progesterone and estrogen receptors (P₄R, E₂R) in the uteri of treated groups. Moreover, plasma E₂, P₄, growth hormone (GH) and prolactin (P) levels were higher (p < 0.05) in G3 and G4. The EBN increased the antioxidant (AO) and total AO capacities (TAC) and reduced oxidative stress (OS) levels in pregnant rats. In conclusion, findings of this study revealed that EBN enhances fertility and embryo implantation rate via promoting proliferation and differentiation of uterine structures as evidenced by the upregulation of the expressions of steroid receptors, EGF, EGFR, VEGF, and PCNA in the uterus. Furthermore, observations of improved growth of ultrastructural pinopods that assist in embryo attachment with uterine epithelium, increased concentrations of E₂, P₄, GH and P levels, as well as increased AO capacities with reduced OS levels in the treated groups might reflect additional possible mechanisms by which EBN enhances embryo implantation rate and pregnancy success.

Maternal folic acid supplementation for the prevention of preeclampsia: A systematic review and meta-analysis

BACKGROUND

Preeclampsia is a significant contributor to maternal and neonatal morbidity and mortality. Folic acid supplementation is recommended periconceptionally for the prevention of neural tube defects. Epidemiological evidence suggests that maternal folic acid supplementation may play a role in preventing other adverse birth outcomes. This systematic review aimed to investigate the effect of maternal folic acid supplementation during pregnancy on risk of preeclampsia and gestational hypertension.

METHODS

Multiple scientific databases and grey literature were searched for relevant studies. Studies were reviewed according to pre-specified inclusion and exclusion criteria. Study characteristics were summarised and study quality was assessed. A meta-analysis of observational studies was conducted to examine the effect of maternal folic acid supplementation on preeclampsia risk.

RESULTS

Meta-analysis of eight observational studies showed significantly lower odds of preeclampsia with folic acid supplementation in comparison to no folic acid supplementation: OR = 0.78 (95% CI 0.63, 0.98), with moderately high heterogeneity between studies. Subgroup analysis showed no significant subgroup difference between folic acid supplementation taken by itself, in comparison to folic acid taken in or alongside a multivitamin.

CONCLUSION

Low level evidence is available for a modest association between maternal folic acid supplementation and reduction in preeclampsia risk. Future studies should differentiate between early and late onset and mild vs severe preeclampsia, and should control for relevant confounders including the presence of multivitamin supplements. The protocol for this systematic review was prospectively registered with PROSPERO (CRD42015029310).

Effects of folic acid administration on testicular ischemia/reperfusion injury in rats

PURPOSE

To determine the effect of folic acid (FA) on experimental testicular ischemia/reperfusion (I/R) in rats.

METHODS

Sixty male Wistar rats were randomly divided into 6 groups. The control group received physiologic saline orally. The sham-operated group received physiologic saline orally then exposed to midline laparotomy without clamping the IR. The I/R rats received oral gavage of the saline then subjected to 1h ischemia /24h reperfusion, period. In folic acid (2mg/kg+IR) rats received oral gavage of the FA (2mg/kg) then subjected to 1h I/24h R. groups 5-6 received FA (5 and 10 mg/kg), then subjected to 1 h I/24 h, respectively. At the end of the study, semen samples were collected for spermatozoa characteristics. The left testis was removed for histological analysis and superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GPx) measurement.

RESULTS

Spermatozoa mobility, mortality (%) significantly decreased in I/R group (P<0.05). Dose dependent increase observed on spermatozoa mobility, mortality (%) using different levels of the FA (2, 5 and 10 mg/kg) treated rat (P<0.05). Tissue MDA levels significantly increased in I/R rat (P<0.05) while FA (2, 5 and 10mg/kg) in a dose dependent manner decreased I/R-induced MDA (P<0.05). Experimental I/R significantly decreased SOD and GPx activity (P<0.05). Administration of the FA (2, 5 and 10mg/kg) significantly increased tissue SOD and GPx activity in I/R rat (P<0.05). Seminiferous tubules degenerated and loss of spermatogenesis with few spermatocytes was observed in degenerated testis tubules in I/R rat. Orally administration of the FA (5 and 10 mg/kg) improved testis characteristics with few normal seminiferous tubules and spermatocyte in seminiferous tubules in experimental I/R-induced rat.

CONCLUSION

The treatment of folic acid had a benefit effect against ischemia-reperfusion.

MiR-203 Participates in Human Placental Angiogenesis by Inhibiting VEGFA and VEGFR2 Expression

Angiogenesis during placentation is of great significance in maintaining normal pregnancy. However, the molecular mechanisms of this process are not clear. It has been reported that miR-203 plays a critical role in the development and progression of many tumors but not focused on the relationship between miR-203 and placental angiogenesis. The present study aims to illustrate the correlation between miR-203 and vascular endothelial growth factor (VEGFA)/vascular endothelial growth factor receptors 2 (VEGFR2) in human placenta and human umbilical vein endothelial cells (HUVECs) obtained from 40 samples. Samples of human placenta were collected based on gestation age, which was divided into early preterm (n = 10), late preterm (n = 12), and term (n = 18). In this work, we demonstrated that the expression of miR-203 decreased significantly in the placenta according to the gestation age, in contrast, the expression of VEGFA and VEGFR2 increased accordingly. In vitro experiments revealed that overexpression of miR-203 not only suppressed the proliferation, migration, invasion, and tube formation of HUVECs but also affected the expression of VEGFA and VEGFR2. Furthermore, inhibition of miR-203 expression showed equally apparent positive effects on HUVECs. In conclusion, our study suggests that miR-203 plays an important role in regulating placental angiogenesis through inhibiting the expression of VEGFA and VEGFR2, thus miR-203 may represent a potential therapeutic target for patients with abnormal formation of blood vessels in the placenta.

Beyond organoids: In vitro vasculogenesis and angiogenesis using cells from mammals and zebrafish

The ability to culture complex organs is currently an important goal in biomedical research. It is possible to grow organoids (3D organ-like structures) in vitro; however, a major limitation of organoids, and other 3D culture systems, is the lack of a vascular network. Protocols developed for establishing in vitro vascular networks typically use human or rodent cells. A major technical challenge is the culture of functional (perfused) networks. In this rapidly advancing field, some microfluidic devices are now getting close to the goal of an artificially perfused vascular network. Another development is the emergence of the zebrafish as a complementary model to mammals. In this review, we discuss the culture of endothelial cells and vascular networks from mammalian cells, and examine the prospects for using zebrafish cells for this objective. We also look into the future and consider how vascular networks in vitro might be successfully perfused using microfluidic technology.

Mechanistic Target of Rapamycin Is a Novel Molecular Mechanism Linking Folate Availability and Cell Function

Folate deficiency has been linked to a wide range of disorders, including cancer, neural tube defects, and fetal growth restriction. Folate regulates cellular function mediated by its involvement in the synthesis of nucleotides, which are needed for DNA synthesis, and its function as a methyl donor, which is critical for DNA methylation. Here we review current data showing that folate sensing by mechanistic target of rapamycin (mTOR) constitutes a novel and distinct pathway by which folate modulates cell functions such as nutrient transport, protein synthesis, and mitochondrial respiration. The mTOR signaling pathway responds to growth factors and changes in nutrient availability to control cell growth, proliferation, and metabolism. mTOR exists in 2 complexes, mTOR complex (mTORC) 1 and mTORC2, which have distinct upstream regulators and downstream targets. Folate deficiency in pregnant mice caused a marked inhibition of mTORC1 and mTORC2 signaling in multiple maternal and fetal tissues, downregulation of placental amino acid transporters, and fetal growth restriction. In addition, folate deficiency in primary human trophoblast (PHT) cells resulted in inhibition of mTORC1 and mTORC2 signaling and decreased the activity of key amino acid transporters. Folate sensing by mTOR in PHT cells is independent of the accumulation of homocysteine and requires the proton-coupled folate transporter (PCFT; solute carrier 46A1). Furthermore, mTORC1 and mTORC2 regulate trophoblast folate uptake by modulating the cell surface expression of folate receptor α and the reduced folate carrier. These findings, which provide a novel link between folate availability and cell function, growth, and proliferation, may have broad biological significance given the critical role of folate in normal cell function and the multiple diseases that have been associated with decreased or excessive folate availability. Low maternal folate concentrations are linked to restricted fetal growth, and we propose that the underlying mechanisms involve trophoblast mTOR folate sensing resulting in inhibition of mTORC1 and mTORC2 and downregulation of placental amino acid transporters.

MicroRNA-16 inhibits feto-maternal angiogenesis and causes recurrent spontaneous abortion by targeting vascular endothelial growth factor

Recurrent spontaneous abortion (RSA) is a common health problem that affects women of reproductive age. Recent studies have indicated that microRNAs are important factors in miscarriage. This study investigated the role of miR-16 in regulating vascular endothelial growth factor (VEGF) expression and the pathogenesis of RSA. In this report, clinical samples revealed that miR-16 expression was significantly elevated in the villi and decidua of RSA patients. In vitro, miR-16 upregulation inhibited human umbilical vein endothelial cell proliferation, migration and tube formation. Conversely, the downregulation of miR-16 reversed these effects. In vivo, we demonstrated that abnormal miR-16 levels affect the weights of the placenta and embryo and the number of progeny and microvascular density, as well as cause recurrent abortions by controlling VEGF expression in pregnant mice. VEGF, a potential target gene of miR-16, was inversely correlated with miR-16 expression in the decidua of clinical samples. Furthermore, the luciferase reporter system demonstrated that miR-16 was found to directly downregulate the expression of VEGF by binding a specific sequence of its 3′-untranslated region (3′UTR). Collectively, these data strongly suggest that miR-16 regulates placental angiogenesis and development by targeting VEGF expression and is involved in the pathogenesis of RSA.

Molecular and cellular effects of vitamin B12 forms on human trophoblast cells in presence of excessive folate

Folic acid (FA) and iron are essential supplements during pregnancy. Similarly effects of vitamin B12 (B12) inadequacy and high folate and low B12 status, on pregnancy outcome are available. However there are no mandatory recommendations for B12. There are many forms of B12 viz. Cyanocobalamin (Cbl), Methylcobalamin (MeCbl), Adenosylcobalamin (AdCbl), and Hydroxycobalamin (HCbl) though there is limited consensus on which form has better efficacy. In the present study we have determined effect of various forms of B12 in the presence of two FA concentrations namely normal physiological (20ng/mL; NPFA) and supra-physiological (2000ng/mL; SPFA) concentration to mimic real time situation where FA is in excess due to supplementation. We assessed trophoblastic proliferation, viability, TNFα and EGFr mRNA expression, homocysteine, β-hCG and MDA levels. Trophoblastic viability was significantly suppressed at SPFA concentration and was restored by B12 treatment with Cbl, AdCbl and combination of MeCbl+AdCbl. The mRNA expressions of TNFα were up-regulated, while EGFr were down-regulated at SPFA concentrations, as validated by RT-PCR. Treatment with MeCbl+AdCbl significantly decreased homocysteine and MDA levels at SPFA concentrations. High levels of FA alone had a detrimental effect on placental health and functions as reflected by decreased viability, EGFr expression and increased TNFα expression, homocysteine and MDA levels. Combination of B12 active forms i.e. MeCbl+AdCbl was found to be most effective in neutralising excess folate effect in-vitro.