Placental DNA methylation signatures of prenatal air pollution exposure and potential effects on birth outcomes: an analysis of three prospective cohorts.

BACKGROUND: Pregnancy air pollution exposure (PAPE) has been linked to a wide range of adverse birth and childhood outcomes, but there is a paucity of data on its influence on the placental epigenome, which can regulate the programming of physiological functions and affect child development. This study aimed to investigate the association between prenatal air pollutant exposure concentrations and changes in placental DNA methylation patterns, and to explore the potential windows of susceptibility and sex-specific alterations. METHODS: This multi-site study used three prospective population-based mother-child cohorts: EDEN, PELAGIE, and SEPAGES, originating from four French geographical regions (Nancy, Poitiers, Brittany, and Grenoble). Pregnant women were included between 2003 and 2006 for EDEN and PELAGIE, and between 2014 and 2017 for SEPAGES. The main eligibility criteria were: being older than 18 years, having a singleton pregnancy, and living and planning to deliver in one of the maternity clinics in one of the study areas. A total of 1539 mother-child pairs were analysed, measuring placental DNA methylation using Illumina BeadChips. We used validated spatiotemporally resolved models to estimate PM2·5, PM10, and NO2 exposure over each trimester of pregnancy at the maternal residential address. We conducted a pooled adjusted epigenome-wide association study to identify differentially methylated 5'-C-phosphate-G-3' (CpG) sites and regions (assessed using the Infinium HumanMethylationEPIC BeadChip array, n=871), including sex-specific and sex-linked alterations, and independently validated our results (assessed using the Infinium HumanMethylation450 BeadChip array, n=668). FINDINGS: We identified four CpGs and 28 regions associated with PAPE in the total population, 469 CpGs and 87 regions in male infants, and 150 CpGs and 66 regions in female infants. We validated 35% of the CpGs available. More than 30% of the identified CpGs were related to one (or more) birth outcome and most significant alterations were enriched for neural development, immunity, and metabolism related genes. The 28 regions identified for both sexes overlapped with imprinted genes (four genes), and were associated with neurodevelopment (nine genes), immune system (seven genes), and metabolism (five genes). Most associations were observed for the third trimester for female infants (134 of 150 CpGs), and throughout pregnancy (281 of 469 CpGs) and the first trimester (237 of 469 CpGs) for male infants. INTERPRETATION: These findings highlight the molecular pathways through which PAPE might affect child health in a widespread and sex-specific manner, identifying the genes involved in the major physiological functions of a developing child. Further studies are needed to elucidate whether these epigenetic changes persist and affect health later in life. FUNDING: French Agency for National Research, Fondation pour la Recherche Médicale, Fondation de France, and the Plan Cancer.

Hydrogen gas inhalation ameliorates LPS-induced BPD by inhibiting inflammation via regulating the TLR4-NFκB-IL6/NLRP3 signaling pathway in the placenta.

INTRODUCTION: Hydrogen (H2) is regarded as a novel therapeutic agent against several diseases owing to its inherent biosafety. Bronchopulmonary dysplasia (BPD) has been widely considered among adverse pregnancy outcomes, without effective treatment. Placenta plays a role in defense, synthesis, and immunity, which provides a new perspective for the treatment of BPD. This study aimed to investigate if H2 reduced the placental inflammation to protect the neonatal rat against BPD damage and potential mechanisms. METHODS: We induced neonatal BPD model by injecting lipopolysaccharide (LPS, 1 µg) into the amniotic fluid at embryonic day 16.5 as LPS group. LPS + H2 group inhaled 42% H2 gas (4 h/day) until the samples were collected. We primarily analyzed the neonatal outcomes and then compared inflammatory levels from the control group (CON), LPS group and LPS + H2 group. HE staining was performed to evaluate inflammatory levels. RNA sequencing revealed dominant differentially expressed genes. Bioinformatics analysis (GO and KEGG) of RNA-seq was applied to mine the signaling pathways involved in protective effect of H2 on the development of LPS-induced BPD. We further used qRT-PCR, Western blot and ELISA methods to verify differential expression of mRNA and proteins. Moreover, we verified the correlation between the upstream signaling pathways and the downstream targets in LPS-induced BPD model. RESULTS: Upon administration of H2, the inflammatory infiltration degree of the LPS-induced placenta was reduced, and infiltration significantly narrowed. Hydrogen normalized LPS-induced perturbed lung development and reduced the death ratio of the fetus and neonate. RNA-seq results revealed the importance of inflammatory response biological processes and Toll-like receptor signaling pathway in protective effect of hydrogen on BPD. The over-activated upstream signals [Toll-like receptor 4 (TLR4), nuclear factor kappa-B p65 (NF-κB p65), Caspase1 (Casp1) and NLR family pyrin domain containing 3 (NLRP3) inflammasome] in LPS placenta were attenuated by H2 inhalation. The downstream targets, inflammatory cytokines/chemokines [interleukin (IL)-6, IL-18, IL-1ß, C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 1 (CXCL1)], were decreased both in mRNA and protein levels by H2 inhalation in LPS-induced placentas to rescue them from BPD. Correlation analysis displayed a positive association of TLR4-mediated signaling pathway both proinflammatory cytokines and chemokines in placenta. CONCLUSION: H2 inhalation ameliorates LPS-induced BPD by inhibiting excessive inflammatory cytokines and chemokines via the TLR4-NFκB-IL6/NLRP3 signaling pathway in placenta and may be a potential therapeutic strategy for BPD.

Ghrelin alleviates placental dysfunction by down-regulating NF-κB phosphorylation in LPS-induced rat model of preeclampsia.

In our previous study, we uncovered that ghrelin promotes angiogenesis in human umbilical vein endothelial cells (HUVECs) in vitro by activating the Jagged1/Notch2/VEGF pathway in preeclampsia (PE). However, the regulatory effects of ghrelin on placental dysfunction in PE are unclear. Therefore, we applied Normal pregnant Sprague-Dawley (SD) rats, treated with lipopolysaccharide (LPS), to establish a PE-like rat model. The hematoxylin-eosin (HE) staining method and immunohistochemistry (IHC) technology were used to detect morphological features of the placenta. IHC and Western blot were applied to examine Bax and Bcl-2 expression levels. The concentrations of serum soluble fms-like tyrosine kinase-1 (sFlt1) and placental growth factor (PIGF) were assessed by enzyme-linked immunosorbent assay (ELISA) kit. In addition, the apoptosis rates of JEG-3 and HTR-8/SVneo trophoblast cells were determined by Annexin V-FITC/PI apoptosis detection kit. Cell migratory capacities were assessed by scratch-wound assay, and RNA-sequencing assay was used to determine the mechanism of ghrelin in regulating trophoblast apoptosis. It has been found that ghrelin significantly reduced blood pressure, urinary protein, and urine creatinine in rats with PE, at the meanwhile, ameliorated placental and fetal injuries. Second, ghrelin clearly inhibited placental Bax expression and circulating sFlt-1 as well as elevated placental Bcl-2 expression and circulating PIGF, restored apoptosis and invasion deficiency of trophoblast cells caused by LPS in vitro. Finally, transcriptomics indicated that nuclear factor kappa B (NF-κB) was the potential downstream pathway of ghrelin. Our findings illustrated that ghrelin supplementation significantly improved LPS-induced PE-like symptoms and adverse pregnancy outcomes in rats by alleviating placental apoptosis and promoting trophoblast migration.

Differential impact of perfluorooctanoic acid and fluorotelomer ethoxylates on placental metabolism in mice.

Poly- and perfluoroalkyl substances (PFAS) are a group of compounds with uses in industry and many consumer products. Concerns about the potential health effects of these compounds resulted in regulation by the Stockholm Convention on the use of three of the most common PFAS, including perfluorooctanoic acid (PFOA). Thousands of PFAS remain in production that are unregulated and for which their toxicity is unknown. Our group recently identified a new class of PFAS, fluorotelomer ethoxylates (FTEOs), in indoor dust and industrial wastewater. In this study, we investigated the effect of PFAS on placental metabolism by exposing healthy, pregnant CD-1 mice to PFOA or FTEOs at one of three concentrations (0 ng/L (controls), 5 ng/L, 100 ng/L) (n = 7-8/group). While PFOA is banned and PFOA concentrations in human blood are decreasing, we hypothesize that FTEOs will cause adverse pregnancy outcomes similar to PFOA, the compounds they were meant to replace. Placental tissue samples were collected at embryonic day 17.5 and 1H solid-state magic angle spinning nuclear magnetic resonance spectroscopy was used to determine the relative concentration of placental metabolites (n = 18-20/group). At the highest concentration, the relative concentrations of glucose and threonine were increased and the relative concentration of creatine was decreased in the PFOA-exposed placentas compared to controls (p < 0.05). In contrast, the relative concentrations of asparagine and lysine were decreased and the relative concentration of creatine was increased in the FTEOs-exposed placentas compared to controls (p < 0.05). Partial least squares - discriminant analysis showed the FTEOs-exposed and control groups were significantly separated (p < 0.005) and pathway analysis found four biochemical pathways were perturbed following PFOA exposure, while one pathway was altered following FTEOs exposure. Maternal exposure to PFOA and FTEOs had a significant impact on the placental metabolome, with the effect depending on the pollutant. This work motivates further studies to determine exposure levels and evaluate associations with adverse outcomes in human pregnancies.

Gender associations between phthalate exposure and biomarkers of oxidative stress: A prospective cohort study.

Previous epidemiologic research has shown that phthalate exposure in pregnant women is related to adverse birth outcomes in a sex-specific manner. However, the biological mechanism of phthalate exposure that causes these birth outcomes remains poorly defined. In this research, we investigated the association between phthalate exposure and placental oxidative stress in a large population-based cohort study, aiming to initially explore the relationship between phthalate exposure and gene expression in placental oxidative stress in a sex-specific manner. Quantitative PCR was performed to measure the expression of placental inflammatory mRNAs (HO-1, HIF1α, and GRP78) in 2469 placentae. The multiple linear regression models were used to investigate the associations between mRNA and urinary phthalate monoesters. Phthalate metabolites monomethyl phthalate (MMP) and mono-n-butyl phthalate (MBP) were positively correlated with higher HIF1α expression in placentae of male fetuses (p < .05). Mono-benzyl phthalate (MBzP) increased the expression of HO-1, HIF1α, and GRP78 in placentae of male fetuses, and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) up-regulated the expression of HIF1α and GRP78. Additionally, mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) was negatively correlated with HO-1, HIF1α, and GRP78 in placentae of female fetuses. Maternal phthalate exposure was associated with oxidative stress variations in placental tissues. The associations were closer in the placentas of male fetuses than in that of female ones. The placenta oxidative stress is worth further investigation as a potential mediator of maternal exposure-induced disease risk in children.

Differential Effects of n-3 and n-6 Polyunsaturated Fatty Acids on Placental and Embryonic Growth and Development in Diabetic Pregnant Mice.

The present study aimed to investigate the differential effects of n-3 and n-6 polyunsaturated fatty acids (PUFAs) on placental and embryonic development. Pregnant mice were assigned to five groups: healthy control (HC), diabetes mellitus control (DMC), diabetes + low-dose n-3 PUFA (Ln-3), diabetes + high-dose n-3 PUFA (Hn-3), and diabetes + n-6 PUFA (n-6). On E12.5d, the Hn-3 group, but not the n-6 group, had a higher placenta weight. The weight ratio of embryo to placenta in the n-6 group was significantly lower than in the Hn-3 group but higher than in the DMC group. The Hn-3 group had significantly higher protein levels of VEGF, IGF-1, and IGFBP3, while the n-6 group had lower VEGF than the DMC group. Compared with the DMC group, embryonic Cer-16:0 was significantly higher in the Hn-3 group, while embryonic PC (36:6), PC (38:7), and PE (40:7) were significantly lower in the n-6 group. The embryo and placenta weights were positively correlated with placental VEGF, IGFBP3, and embryonic Cer-16:0, and they were negatively correlated with embryonic PC (36:6) and PE (40:7). The weight ratio of embryo to placenta was negatively correlated with embryonic PC (36:6). In addition, embryonic Cer-16:0 was positively correlated with placental VEGF and IGFBP3. In conclusion, n-3 PUFA and n-6 PUFA improved placental and embryonic growth through different mechanisms.

Cell type-dependent response to benzo(a)pyrene exposure of human placental cell lines under normoxic, hypoxic, and pro-inflammatory conditions.

Benzo(a)pyrene (BaP) can be detected in the human placenta. However, little is known about the effects of BaP exposure on different placental cells under various conditions. In this study, we aimed to investigate the effects of BaP on mitochondrial function, pyrin domain-containing protein 3 (NLRP3) inflammasome, and apoptosis in three human trophoblast cell lines under normoxia, hypoxia, and inflammatory conditions. JEG-3, BeWo, and HTR-8/SVneo cell lines were exposed to BaP under normoxia, hypoxia, or inflammatory conditions for 24 h. After treatment, we evaluated cell viability, apoptosis, aryl hydrocarbon receptor (AhR) protein and cytochrome P450 (CYP) gene expression, mitochondrial function, including mitochondrial DNA copy number (mtDNAcn), mitochondrial membrane potential (ΔΨm), intracellular adenosine triphosphate (iATP), and extracellular ATP (eATP), nitric oxide (NO), NLPR3 inflammasome proteins, and interleukin (IL)-1ß. We found that BaP upregulated the expression of AhR or CYP genes to varying degrees in all three cell lines. Exposure to BaP alone increased ΔΨm in all cell lines but decreased NO in BeWo and HTR-8/SVneo, iATP in HTR-8/SVneo, and cell viability in JEG-3, without affecting apoptosis. Under hypoxic conditions, BaP did not increase the expression of AhR and CYP genes in JEG-3 cells but increased CYP gene expression in two others. Pro-inflammatory conditions did not affect the response of the 3 cell lines to BaP with respect to the expression of CYP genes and changes in the mitochondrial function and NLRP3 inflammasome proteins. In addition, in HTR-8/SVneo cells, BaP increased IL-1ß secretion in the presence of hypoxia and poly(I:C). In conclusion, our results showed that BaP affected mitochondrial function in trophoblast cell lines by increasing ΔΨm. This increased ΔΨm may have rescued the trophoblast cells from activation of the NLRP3 inflammasome and apoptosis after BaP treatment. We also observed that different human trophoblast cell lines had cell type-dependent responses to BaP exposure under normoxia, hypoxia, or pro-inflammatory conditions.

Cadmium exposure activates mitophagy through downregulating thyroid hormone receptor/PGC1α signal in preeclampsia.

Gestational cadmium exposure increases the risk of preeclampsia. Placenta mitophagy was activated in preeclampsia. The aim of present study was to explore the mechanism of cadmium-induced mitophagy activation and its association with preeclampsia. Mitophagy markers expression levels were detected by quantitative real-time PCR, Western blot, immunofluorescence and immunochemistry in preeclampsia placenta. JEG3 cells were treated with CdCl2, iopanoic acid (IOP), 3-methyladenine and PGC1α SiRNA to verify mechanism of cadmium-induced mitophagy. Mitophagy marker LC3BII/I and P62 expression were increased and mitochondrial membrane receptor protein TOM20 and FUNDC1 expression were decreased in preeclampsia placenta as compared with that in normotension control. Mitophagy marker LC3BII/I and P62 expression were increased and TOM20 and FUNDC1 expression was decreased in CdCl2-treated JEG3 cells. Meanwhile, mitochondrial biogenesis regulator, PGC1α expression was decreased in preeclampsia and CdCl2-treated JEG3 cells. The expressions of LC3B and P62 were increased and the expressions of TOM20, FUNDC1 and PGC1α were decreased in IOP-treated cell. PGC1α SiRNA transfection led to increased expression of LC3BII/I and P62 and decreased expression of TOM20 and FUNDC1. The expression of sFlt1 was increased in preeclampsia placenta, CdCl2-treated cells, in IOP-treated cells and in PGC1α SiRNA transfected cells. 3-methyladenine treatment protected the increased expression of sFlt1 in CdCl2-treated cells, in IOP-treated cells and in PGC1α SiRNA transfected cells. Meanwhile, co-treatment of cadmium and IOP or PGC1αSiRNA led to a reduce expressions of OPA1, MFN1, MFN2 and FUNDC1 as compared to cadmium-treated, IOP-treated and PGC1α SiRNA-treated cells. These results elucidated that maternal cadmium exposure activated placenta mitophagy through downregulation of thyroid hormone receptor signal mediated decreased expression of PGC1α and was associated with the occurrence of preeclampsia.

d-galactose causes embryonic development arrest and placental development disorders in mice by increasing ROS and inhibiting SIRT1/FOXO3a axis.

INTRODUCTION: Does an elevation in d-Galactose (D-Gal) levels within the body contribute to abnormal embryonic development and placental dysfunction during pregnancy? METHODS: Mouse embryos were cultivated to the blastocyst stage under varying concentrations of D-Gal. The blastocyst formation rate was measured, and the levels of reactive oxygen species (ROS), sirtuin 1 (SIRT1), and forkhead box O3a (FOXO3a) in blastocysts were assessed. Mice were intraperitoneally injected with either saline or D-Gal with or without SRT1720. On the 14th day of pregnancy, the fetal absorption rate and placental weight were recorded. Placental levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. The expression of senescence-related factors, such as senescence-associated ß-galactosidase (SA-ß-gal) in the placenta was examined, and the expression of placental SIRT1, FOXO3a and p21 was evaluated by immunohistochemistry and Western blotting. RESULTS: D-Gal adversely affects early embryonic development in vitro, resulting in a decreased blastocyst formation rate. Furthermore, D-Gal downregulates SIRT1 and FOXO3a while increasing ROS levels in blastocysts. Concurrently, D-Gal induces placental dysfunction, characterized by an elevated fetal absorption rate, reduced placental weight, diminished SOD activity, and increased MDA content. The senescence-related factor SA-ß-gal was detected in the placenta, along with altered expression of placental SIRT1, FOXO3a, and p21. The SIRT1 agonist SRT1720 mitigated this damage by increasing SIRT1 and FOXO3a expression. DISCUSSION: The inhibition of early embryonic development and placental dysfunction induced by D-Gal may be attributed to the dysregulation of SIRT1. Activating SIRT1 emerges as a potentially effective strategy for alleviating the adverse effects of D-Gal exposure.

Maternal exposure to beta-Cypermethrin disrupts placental development by dysfunction of trophoblast cells from oxidative stress.

As a broad-spectrum and efficient insecticide, beta-Cypermethrin (ß-CYP) poses a health risk to pregnancy. It matters the mechanisms of maternal exposure to ß-CYP for impacting reproductive health. The placenta, a transient organ pivotal for maternal-fetal communication during pregnancy, plays a crucial role in embryonic development. The effect of ß-CYP exposure on the placenta and its underlying molecular mechanisms remain obscure. The objective of this study was to investigate the effect of ß-CYP exposure on placental development and the function of trophoblast, as well as the underlying mechanisms through CD-1 mouse model (1, 10, 20 mg/kg.bw) and in vitro HTR-8/SVneo cell model (12.5, 25, 50, 100 µM). We found slower weight gain and reduced uterine wet weight in pregnant mice with maternal exposure to ß-CYP during pregnancy, as well as adverse pregnancy outcomes such as uterine bleeding and embryo resorption. The abnormal placental development in response to ß-CYP was noticed, including imbalanced placental structure and disrupted labyrinthine vascular development. Trophoblasts, pivotal in placental development and vascular remodeling, displayed abnormal differentiation under ß-CYP exposure. This aberration was characterized by thickened trophoblast layers in the labyrinthine zone, accompanied by mitochondrial and endoplasmic reticulum swelling within trophoblasts. Further researches on human chorionic trophoblast cell lines revealed that ß-CYP exposure induced apoptosis in HTR-8/SVneo cells. This induction resulted in a notable decrease in migration and invasion abilities, coupled with oxidative stress and the inhibition of the Notch signaling pathway. N-acetylcysteine (an antioxidant) partially restored the impaired Notch signaling pathway in HTR-8/SVneo cells, and mitigated cellular functional damage attributed to ß-CYP exposure. Collectively, exposure to ß-CYP induced oxidative stress and then led to inhibition of the Notch signaling pathway and dysfunction of trophoblast cells, ultimately resulted in abnormal placenta and pregnancy. These findings indicate Reactive Oxygen Species as potential intervention targets to mitigate ß-CYP toxicity. The comprehensive elucidation contributes to our understanding of ß-CYP biosafety and offers an experimental basis for preventing and managing its reproductive toxicity.

Baicalein improves the symptoms of polycystic ovary syndrome by mitigating oxidative stress and ferroptosis in the ovary and gravid placenta.

BACKGROUND: Polycystic ovary syndrome is a metabolic and hormonal disorder that is closely linked to oxidative stress. Within individuals diagnosed with PCOS, changes occur in the ovaries, resulting in an excessive buildup of iron and peroxidation of lipids, both of which may be associated with the occurrence of ferroptosis. Baicalein, a flavonoid found in the roots of Scutellaria baicalensis and widely known as Chinese skullcap, is known for its anti-inflammatory and anti-ferroptotic properties, which protect against various diseases. Nevertheless, there has been no investigation into the impact of baicalein on polycystic ovary syndrome. PURPOSE: This study aimed to correlate ferroptosis with polycystic ovary syndrome and to assess the effects of baicalein on ovarian dysfunction and placental development in pregnant patients. STUDY DESIGN AND METHODS: Polycystic ovary syndrome was induced in a rat model through the administration of dehydroepiandrosterone, and these rats were treated with baicalein. Oxidative stress and inflammation levels were assessed in serum and ovaries, and tissue samples were collected for histological and protein analyses. Furthermore, different groups of female rats were mated with male rats to observe pregnancy outcomes and tissue samples were obtained for histological, protein, and RNA sequencing. Then, RNA sequencing of the placenta was performed to determine the key genes involved in ferroptosis negative regulation (FNR) signatures. RESULTS: Baicalein was shown to reduce ovarian oxidative stress and pathology. Baicalein also ameliorated polycystic ovary syndrome by decreasing lipid peroxidation and chronic inflammation and modulating mitochondrial functions and ferroptosis in the ovaries. Specifically, glutathione peroxidase and ferritin heavy chain 1 were considerably downregulated in polycystic ovary syndrome gravid rats compared to their expression in the control group, and most of these differences were reversed after baicalein intervention. CONCLUSIONS: Our findings, initially, indicated that baicalein could potentially enhance the prognosis of individuals suffering from polycystic ovary syndrome by reducing oxidative stress and ferroptosis, thus potentially influencing the formulation of a therapeutic approach to address this condition.

Single pulmonary nanopolystyrene exposure in late-stage pregnancy dysregulates maternal and fetal cardiovascular function.

Large-scale production and waste of plastic materials have resulted in widespread environmental contamination by the breakdown product of bulk plastic materials to micro- and nanoplastics (MNPs). The small size of these particles enables their suspension in the air, making pulmonary exposure inevitable. Previous work has demonstrated that xenobiotic pulmonary exposure to nanoparticles during gestation leads to maternal vascular impairments, as well as cardiovascular dysfunction within the fetus. Few studies have assessed the toxicological consequences of maternal nanoplastic (NP) exposure; therefore, the objective of this study was to assess maternal and fetal health after a single maternal pulmonary exposure to polystyrene NP in late gestation. We hypothesized that this acute exposure would impair maternal and fetal cardiovascular function. Pregnant rats were exposed to nanopolystyrene on gestational day 19 via intratracheal instillation. 24 h later, maternal and fetal health outcomes were evaluated. Cardiovascular function was assessed in dams using vascular myography ex vivo and in fetuses in vivo function was measured via ultrasound. Both fetal and placental weight were reduced after maternal exposure to nanopolystyrene. Increased heart weight and vascular dysfunction in the aorta were evident in exposed dams. Maternal exposure led to vascular dysfunction in the radial artery of the uterus, a resistance vessel that controls blood flow to the fetoplacental compartment. Function of the fetal heart, fetal aorta, and umbilical artery after gestational exposure was dysregulated. Taken together, these data suggest that exposure to NPs negatively impacts maternal and fetal health, highlighting the concern of MNPs exposure on pregnancy and fetal development.

Effect of Aromatase Inhibitor Letrozole on the Placenta of Adult Albino Rats: A Histopathological, Immunohistochemical, and Biochemical Study.

Background: Letrozole, an aromatase inhibitor, has recently been introduced as the preferred treatment option for ectopic pregnancy. To date, no study has investigated the effect of letrozole alone on placental tissue. The present study aimed to evaluate the effect of different doses of letrozole on the placenta of rats and to clarify the underlying mechanism. Methods: Sixty pregnant female rats were equally divided into three groups, namely the control group (GI), low-dose (0.5 mg/Kg/day) letrozole group (GII), which is equivalent to the human daily dose (HED) of 5 mg, and high-dose (1 mg/Kg/day) letrozole group (GIII), equivalent to the HED of 10 mg. Letrozole was administered by oral gavage daily from day 6 to 16 of gestation. Data were analyzed using a one-way analysis of variance followed by Tukey's post hoc test and Chi square test. P<0.05 was considered statistically significant. Results: Compared to the GI and GII groups, high-dose letrozole significantly increased embryonic mortality with a high post-implantation loss rate (P<0.001) and significantly reduced the number of viable fetuses (P<0.001) and placental weight (P<0.001) of pregnant rats. Moreover, it significantly reduced placental estrogen receptor (ER) and progesterone receptor (PR) (P<0.001) and the expression of vascular endothelial growth factor (P<0.001), while increasing the apoptotic index of cleaved caspase-3 (P<0.001). Conclusion: Letrozole inhibited the expression of ER and PR in rat placenta. It interrupted stimulatory vascular signals causing significant apoptosis and placental vascular dysfunction. Letrozole in an equivalent human daily dose of 10 mg caused a high post-implantation loss rate without imposing severe side effects.

Maternal supplementation of curcumin-olive oil nanocomposite improves uteroplacental blood flow, placental growth and antioxidant capacity in goats.

This experiment was designed to investigate the impact of curcumin-olive oil nanocomposite (CONC) supplementation on uteroplacental hemodynamics and ultrasonographic measurements as well as maternal oxidative status in midgestating goats. Twelve synchronized pregnant goats (85.58 ± 1.08 days of gestation; mean ± SD) were uniformly assigned to two groups (n = 6/group); the first group received daily oral supplementation of CONC (3 mg/kg body weight; nanocurcumin [NC] group) for 32 days, and the second group was offered physiological saline (control) following the NC group timeline. The goats of both groups were examined at 3-day intervals for middle uterine (MUA) and umbilical (UMA) arteries hemodynamics (pulsatility index [PI], resistive index [RI], systole/diastole [S/D] and blood flow rate [BFR]) and diameters, uteroplacental thickness (UPT), placentomes' diameter (PD) and echogenicity, steroid hormones (progesterone and estradiol 17ß), oxidative biomarkers (total antioxidant capacity [TAC], catalase [CAT], malondialdehyde [MDA]), nitric oxide (NO) and blood cells DNA integrity. The UPT (p = 0.012) and PD (p = 0.021) values were higher in the NC group than in their counterparts' control group (D11-32). There were increases in diameter (p = 0.021 and p = 0.012) and decreases (p = 0.021, p = 0.016 and p = 0.041 [MUA]; p = 0.015, p = 0.023 and p = 0.011 [UMA] respectively) in Doppler indices (PI, RI and S/D) of the MUA and UMA in the NC group compared to the control group (D14-32). On D20-32 (MUA) and D14-32 (UMA), the NC goats had higher BFR than the control group (p = 0.021, 0.018 respectively). The means of blood cells with fragmented DNA were lower (p = 0.022) in the NC group than in the control group on Days 8 and 21 postsupplementation. There were increases in CAT and NO (D20-32; p = 0.022 and p = 0.004 respectively), and TAC (D17-32; p = 0.007) levels in the NC goats compared to the control ones. The NC group had lower (p = 0.029) concentrations of MDA than the control group on Day 20 postsupplementation onward. In conclusion, oral supplementation of CONC improved uteroplacental blood flow and the antioxidant capacity of midgestating goats.

Gestational exposure to 1-NP induces ferroptosis in placental trophoblasts via CYP1B1/ERK signaling pathway leading to fetal growth restriction.

Fetal growth restriction (FGR) is a prevalent complication in obstetrics, yet its exact aetiology remains unknown. Numerous studies suggest that the degradation of the living environment is a significant risk factor for FGR. 1-Nitropyrene (1-NP) is a widespread environmental pollutant as a representative substance of nitro-polycyclic aromatic hydrocarbons. In this study, we revealed that 1-NP induced FGR in fetal mice by constructing 1-NP exposed pregnant mice models. Intriguingly, we found that placental trophoblasts of 1-NP exposed mice exhibited significant ferroptosis, which was similarly detected in placental trophoblasts from human FGR patients. In this regard, we established a 1-NP exposed cell model in vitro using two human trophoblast cell lines, HTR8/SVneo and JEG-3. We found that 1-NP not only impaired the proliferation, migration, invasion and angiogenesis of trophoblasts, but also induced severe cellular ferroptosis. Meanwhile, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively rescued 1-NP-induced trophoblast biological function impairment. Mechanistically, we revealed that 1-NP regulated ferroptosis by activating the ERK signaling pathway. Moreover, we innovatively revealed that CYP1B1 was essential for the activation of ERK signaling pathway induced by 1-NP. Overall, our study innovatively identified ferroptosis as a significant contributor to 1-NP induced trophoblastic functional impairment leading to FGR and clarified the specific mechanism by which 1-NP induced ferroptosis via the CYP1B1/ERK signaling pathway. Our study provided novel insights into the aetiology of FGR and revealed new mechanisms of reproductive toxicity of environmental pollutants.

Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function.

Importance: Cannabis use is increasing among reproductive-age individuals and the risks associated with cannabis exposure during pregnancy remain uncertain. Objective: To evaluate the association between maternal cannabis use and adverse pregnancy outcomes known to be related to placental function. Design, Setting, and Participants: Ancillary analysis of nulliparous individuals treated at 8 US medical centers with stored urine samples and abstracted pregnancy outcome data available. Participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort were recruited from 2010 through 2013; the drug assays and analyses for this ancillary project were completed from June 2020 through April 2023. Exposure: Cannabis exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol using frozen stored urine samples from study visits during the pregnancy gestational age windows of 6 weeks and 0 days to 13 weeks and 6 days (visit 1); 16 weeks and 0 days to 21 weeks and 6 days (visit 2); and 22 weeks and 0 days to 29 weeks and 6 days (visit 3). Positive results were confirmed with liquid chromatography tandem mass spectrometry. The timing of cannabis exposure was defined as only during the first trimester or ongoing exposure beyond the first trimester. Main Outcome and Measure: The dichotomous primary composite outcome included small-for-gestational-age birth, medically indicated preterm birth, stillbirth, or hypertensive disorders of pregnancy ascertained by medical record abstraction by trained perinatal research staff with adjudication of outcomes by site investigators. Results: Of 10 038 participants, 9257 were eligible for this analysis. Of the 610 participants (6.6%) with cannabis use, 32.4% (n = 197) had cannabis exposure only during the first trimester and 67.6% (n = 413) had ongoing exposure beyond the first trimester. Cannabis exposure was associated with the primary composite outcome (25.9% in the cannabis exposure group vs 17.4% in the no exposure group; adjusted relative risk, 1.27 [95% CI, 1.07-1.49]) in the propensity score-weighted analyses after adjustment for sociodemographic characteristics, body mass index, medical comorbidities, and active nicotine use ascertained via urine cotinine assays. In a 3-category cannabis exposure model (no exposure, exposure only during the first trimester, or ongoing exposure), cannabis use during the first trimester only was not associated with the primary composite outcome; however, ongoing cannabis use was associated with the primary composite outcome (adjusted relative risk, 1.32 [95% CI, 1.09-1.60]). Conclusions and Relevance: In this multicenter cohort, maternal cannabis use ascertained by biological sampling was associated with adverse pregnancy outcomes related to placental dysfunction.

Oxycodone does not affect placental circulatory physiology during the early first stage of labor-A randomized trial.

INTRODUCTION: Opioids are used for pain relief during the first stage of labor. Oxycodone can cause maternal hypotension that may modify utero- and fetoplacental circulatory physiology. We hypothesized that maternal intravenous (i.v.) oxycodone has no detrimental effect on utero- and fetoplacental hemodynamics during the early first stage of labor. MATERIAL AND METHODS: Twenty-two parturients requiring pain relief during the first stage of labor were randomized in a double-blinded and placebo-controlled study. By Doppler ultrasonography, both uterine artery (Ut) and umbilical vein (UV) volume blood flows (Q), Ut pulsatility index (PI), and Ut vascular resistance (RUt) were calculated. Blood flow velocity waveforms were obtained between uterine contractions. After baseline measurements, women received oxycodone 0.05 mg/kg or a placebo intravenous. Doppler ultrasonography was repeated up to 120 min after the first drug administration. The second dose of oxycodone 0.05 mg/kg was allowed at 60 min to all parturients with contraction pain ≥5/10. Maternal plasma samples were collected at each study phase and after delivery with umbilical cord plasma samples, to measure oxycodone concentrations. CLINICALTRIALS: gov identifier (NCT no. NCT02573831). RESULTS: At baseline, mean QUt and QUV did not differ significantly between the placebo-first (478 mL/min and 57 mL/min/kg) and the oxycodone-first (561 mL/min and 71 mL/min/kg) groups. In addition, RUt and Ut PI were comparable between the groups. Following oxycodone at 60 min, mean QUt and QUV (714 mL/min and 52 mL/min/kg) were similar to the placebo-first (520 mL/min and 55 mL/min/kg) group. Furthermore, all the measured parameters were comparable to the baseline values. At 60 min after the first study drug administration, all the parturients in the placebo-first group needed intravenous oxycodone 0.05 mg/kg. At 120 min, we found no statistically significant change in any of the measured parameters. No significant correlation was found between maternal oxycodone concentration and QUt or QUV. Furthermore, newborn oxycodone concentration did not correlate with QUV. CONCLUSIONS: Oxycodone did not have any detrimental effect on either utero- or fetoplacental circulatory physiology during the early first stage of labor. Maternal plasma oxycodone did not correlate with utero- and fetoplacental hemodynamics. No correlation was found between newborn oxycodone concentration and fetoplacental hemodynamics.

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.

Role of progesterone on dexamethasone-induced alterations in placental vascularization and progesterone receptors in rats†.

BACKGROUND: Intrauterine growth restriction (IUGR) is manifested by lower maternal progesterone levels, smaller placental size, and decreased placental vascularity indicated by lower expression of vascular endothelial growth factor (VEGF). Studies showed that progesterone increases angiogenesis and induces VEGF expression in different tissues. Therefore, the aim of the present study is to evaluate the effect of progesterone on placental vascular bed and VEGF expression and the modulation of nuclear and membranous progesterone receptors (PR) in dexamethasone-induced rat IUGR model. METHODS: Pregnant Sprague-Dawley rats were allocated into four groups and given intraperitoneal injections of either saline, dexamethasone, dexamethasone, and progesterone or progesterone. Injections started on gestation day (DG) 15 and lasted until the days of euthanization (19 and 21 DG). Enzyme-linked immunosorbent assay was used to evaluate plasma progesterone levels. Real-time PCR and western blotting were used to evaluate gene and protein expressions of VEGF, and PR in labyrinth and basal placental zones. Immunohistochemistry was used to locate VEGF and different PRs in placental cells. Immunofluorescence was used to monitor the expression of blood vessel marker (αSMA). RESULTS: Dexamethasone decreased the vascular bed fraction and the expression of VEGF in both placental zones. Progesterone co-treatment with dexamethasone prevented this reduction. Nuclear and membrane PRs showed tissue-specific expression in different placental zones and responded differently to both dexamethasone and progesterone. CONCLUSIONS: Progesterone treatment improves the outcomes in IUGR pregnancy. Progesterone alleviated DEX-induced IUGR probably by promoting placental VEGF and angiogenesis.

Toxicological effects of the Morinda citrifolia L. fruit extract on maternal reproduction and fetal development in rats.

Morinda citrifolia L., also known as Noni, is widely used plant in folk medicine for various therapeutic purposes. However, reports on its effects during pregnancy are limited. Therefore, the objective of this study was to evaluate the effects of the M. citrifolia fruit extract on maternal performance and fetal development during pregnancy in rats. Pregnant Wistar rats (n = 12/group) were treated from gestational days (GD) 0-21 with water (control group) or the aqueous extract of M. citrifolia fruit at doses of 200, 400, or 750 mg/kg, orally. During pregnancy, clinical signs of toxicity, maternal weight, feed intake, and water consumption were noted. On GD 21, the rats were anesthetized and blood was collected to evaluate various biochemical parameters. During laparotomy, reproductive performance parameters were recorded, and fetuses were weighed and the anomalies analyzed. Reduced placental efficiency and fetal growth restriction were observed in the group treated with 400 mg/kg of M. citrifolia extract. The highest dose (750 mg/kg) augmented aspartate aminotransferase concentration and preimplantation losses, while reducing the number of live fetuses. Furthermore, both doses (400 and 750 mg/kg) of the plant extract caused fetal anomalies. In conclusion, consumption of high doses of the M. citrifolia aqueous extrac during pregnancy leads to maternal hepatotoxicity, anti-implantation effects, intrauterine growth restriction and fetal abnormalities, indicating that the plant fruit extract can be harmful to both the mother and the fetus.