Inflammation-induced fetal growth restriction in rats is associated with increased placental HIF-1α accumulation

The interaction of ER stress and autophagy in trophoblasts: navigating pregnancy outcome†

The endoplasmic reticulum is a complex and dynamic organelle that initiates unfolded protein response and endoplasmic reticulum stress in response to the accumulation of unfolded or misfolded proteins within its lumen. Autophagy is a paramount intracellular degradation system that facilitates the transportation of proteins, cytoplasmic components, and organelles to lysosomes for degradation and recycling. Preeclampsia and intrauterine growth retardation are two common complications of pregnancy associated with abnormal trophoblast differentiation and placental dysfunctions and have a major impact on fetal development and maternal health. The intricate interplay between endoplasmic reticulum stress, and autophagy and their impact on pregnancy outcomes, through mediating trophoblast differentiation and placental development, has been highlighted in various reports. Autophagy controls trophoblast regulation through a variety of gene expressions and signaling pathways while excessive endoplasmic reticulum stress triggers downstream apoptotic signaling, culminating in trophoblast apoptosis. This comprehensive review delves into the intricacies of placental development and explores the underlying mechanisms of preeclampsia and intrauterine growth retardation. In addition, this review will elucidate the molecular mechanisms of endoplasmic reticulum stress and autophagy, both individually and in their interplay, in mediating placental development and trophoblast differentiation, particularly highlighting their roles in preeclampsia and intrauterine growth retardation development. This research seeks to the interplay between endoplasmic reticulum stress and impaired autophagy in the placental trophoderm, offering novel insights into their contribution to pregnancy complications.

Manganese porphyrin-based treatment improves fetal-placental development and protects against oxidative damage and NLRP3 inflammasome activation in a rat maternal hypothyroidism model

Oxidative stress (OS) and endoplasmic reticulum stress (ERS) are at the genesis of placental disorders observed in preeclampsia, intrauterine growth restriction, and maternal hypothyroidism. In this regard, cationic manganese porphyrins (MnPs) comprise potent redox-active therapeutics of high antioxidant and anti-inflammatory potential, which have not been evaluated in metabolic gestational diseases yet. This study evaluated the therapeutic potential of two MnPs, [MnTE-2-PyP]5+ (MnP I) and [MnT(5-Br-3-E-Py)P]5+ (MnP II), in the fetal-placental dysfunction of hypothyroid rats. Hypothyroidism was induced by administration of 6-Propyl-2-thiouracil (PTU) and treatment with MnPs I and II 0.1 mg/kg/day started on the 8th day of gestation (DG). The fetal and placental development, and protein and/or mRNA expression of antioxidant mediators (SOD1, CAT, GPx1), hypoxia (HIF1α), oxidative damage (8-OHdG, MDA), ERS (GRP78 and CHOP), immunological (TNFα, IL-6, IL-10, IL-1β, IL-18, NLRP3, Caspase1, Gasdermin D) and angiogenic (VEGF) were evaluated in the placenta and decidua on the 18th DG using immunohistochemistry and qPCR. ROS and peroxynitrite (PRX) were quantified by fluorometric assay, while enzyme activities of SOD, GST, and catalase were evaluated by colorimetric assay. MnPs I and II increased fetal body mass in hypothyroid rats, and MnP I increased fetal organ mass. MnPs restored the junctional zone morphology in hypothyroid rats and increased placental vascularization. MnPs blocked the increase of OS and ERS mediators caused by hypothyroidism, showing similar levels of expression of HIFα, 8-OHdG, MDA, Gpx1, GRP78, and Chop to the control. Moreover, MnPs I and/or II increased the protein expression of SOD1, Cat, and GPx1 and restored the expression of IL10, Nlrp3, and Caspase1 in the decidua and/or placenta. However, MnPs did not restore the low placental enzyme activity of SOD, CAT, and GST caused by hypothyroidism, while increased the decidual and placental protein expression of TNFα. The results show that treatment with MnPs improves the fetal-placental development and the placental inflammatory state of hypothyroid rats and protects against oxidative stress and reticular stress caused by hypothyroidism at the maternal-fetal interface.

Cited2 is a key regulator of placental development and plasticity

The biology of trophoblast cell lineage development and placentation is characterized by the involvement of several known transcription factors. Central to the action of a subset of these transcriptional regulators is CBP-p300 interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2). CITED2 acts as a coregulator modulating transcription factor activities and affecting placental development and adaptations to physiological stressors. These actions of CITED2 on the trophoblast cell lineage and placentation are conserved across the mouse, rat, and human. Thus, aspects of CITED2 biology in hemochorial placentation can be effectively modeled in the mouse and rat. In this review, we present information on the conserved role of CITED2 in the biology of placentation and discuss the use of CITED2 as a tool to discover new insights into regulatory mechanisms controlling placental development.

HIF-1α regulated pathomechanism of low birth weight through angiogenesis factors in placental Plasmodium vivax infection

Background

Malaria in pregnancy leads to placental malaria. The primary pathogenesis of the complex fetal implications in placental malaria is tissue hypoxia due to sequestrations of Plasmodium falciparum-infected erythrocytes in the placenta. However, the pathomechanism of placental Plasmodium vivax infection has not been thoroughly investigated. Hypoxia-inducible factor-1α (HIF-1α) is a key transcriptional mediator of the response to hypoxic conditions, which interacts with the change and imbalances of many chemical mediators, including angiogenic factors, leading to fetal growth abnormality.

Methods

This study was conducted cross-sectionally in Maumere, Sikka Regency, East Nusa Tenggara Province, previously known as one of the malaria endemic areas with a high incidence of low birth weight (LBW) cases. This study collected peripheral and umbilical blood samples and placental tissues from mothers who delivered their babies with LBW at the TC Hiller Regional Hospital. All of the blood samples were examined for parasites by microscopic and PCR techniques, while the plasma levels of VEGF, PlGF, VEGFR-1, VEGFR-2, and HIF-1α were determined using ELISA. The sequestration of infected erythrocytes and hemozoin was determined from placental histological slides, and the expression of placenta angiogenic factors was observed using the immunofluorescent technique.

Results

In this study, 33 cases had complete data to be analyzed. Of them, 19 samples were diagnosed as vivax malaria and none of falciparum malaria. There were significant differences in Δ 10th percentile growth curve of baby's body weights and also all angiogenic factors in placental tissues {VEGF, PlGF, and VEGFR-1, VEGFR-2, and HIF-1α} between those infected and not infected cases (p<0.05), but not for VEGF and VEGFR-2 in the plasma.

Conclusion

This study indicated that Plasmodium vivax sequestration may promote LBW through alterations and imbalances in angiogenic factors led by HIF-1α.

High amniotic fluid fractalkine and MIP-1β levels are associated with intrauterine growth restriction: a prospective cohort study

Background/aim

Proinflammatory chemokines have been shown to play crucial roles in implantation, spiral artery invasion, and the fetomaternal immunological response. In this context, we investigated the levels of fractalkine (CX3CL1) and chemokine CC motif ligand 4 (CCL4 or MIP-1β) in maternal serum and amniotic fluids in pregnant women with intrauterine growth restriction (IUGR).

Materials and methods

This prospective cohort study was carried out at Fırat University Obstetrics Clinic between January 1, 2022 and July 1, 2022. Group (G) 1: The control group consisted of 40 pregnant women who underwent elective cesarean section (CS) at 38-40 weeks of gestation. G2: A total of 40 pregnant women with IUGR at 28-37 weeks of gestation were included in the study group. Levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), hypoxia-inducible factor-1 alpha (HIF-1α), macrophage inflammatory protein-1 beta (MIP-1β), and fractalkine were measured in maternal serum and amniotic fluid samples obtained during CS.

Results

When maternal age was compared, no statistically significant difference was observed between G1 and G2 (p = 0.374). The number of gravidity was found to be statistically higher in G1 compared to G2 (p = 0.003). The mean gestational week was statistically higher in G1 (p < 0.001). Maternal serum MIP-1β (p = 0.03) and IFN-γ (p = 0.006) levels were higher in G1. The birth weight of the baby (p < 0.001) and umbilical cord blood gas pH value (p < 0.001) at birth were higher in G1. HIF-1α (p < 0.001), fractalkine (p < 0.001), MIP-1β (p < 0.001), TNF-α (p = 0.007), IL-1β (p < 0.001), and IFN-γ levels (p = 0.007) in amniotic fluid were higher in G2.

Conclusion

Elevated levels of proinflammatory factors, including fractalkine and MIP-1β, along with inflammatory factors such as TNF-α, IL-1β, and IFN-γ, as well as increased HIF-1α levels in amniotic fluid, are associated with intrauterine growth restriction (IUGR) attributed to a hypoxic amniotic environment.

Gut Microbiota, Inflammation, and Probiotic Supplementation in Fetal Growth Restriction-A Comprehensive Review of Human and Animal Studies

Fetal growth restriction (FGR) is a pathological state that represents a fetus's inability to achieve adequate growth during pregnancy. Several maternal, placental, and fetal factors are likely associated with FGR etiology. FGR is linked to severe fetal and neonatal complications, as well as adverse health consequences in adulthood. Numerous randomized controlled trials (RCTs) have demonstrated improved growth in FGR fetuses with promising treatment strategies such as maternal micronutrient, amino acid, and nitric oxide supplementation. Elevated inflammation in pregnant women diagnosed with FGR has been associated with an imbalance between pro- and anti-inflammatory cytokines. Gut microbiota dysbiosis may result in increased FGR-related inflammation. Probiotic treatment may relieve FGR-induced inflammation and improve fetal growth. The aim of this review is to provide an overview of the gut microbiota and inflammatory profiles associated with FGR and explore the potential of probiotics in treating FGR.

From Molecules to Imaging: Assessment of Placental Hypoxia Biomarkers in Placental Insufficiency Syndromes

Placental hypoxia poses significant risks to both the developing fetus and the mother during pregnancy, underscoring the importance of early detection and monitoring. Effectively identifying placental hypoxia and evaluating the deterioration in placental function requires reliable biomarkers. Molecular biomarkers in placental tissue can only be determined post-delivery and while maternal blood biomarkers can be measured over time, they can merely serve as proxies for placental function. Therefore, there is an increasing demand for non-invasive imaging techniques capable of directly assessing the placental condition over time. Recent advancements in imaging technologies, including photoacoustic and magnetic resonance imaging, offer promising tools for detecting and monitoring placental hypoxia. Integrating molecular and imaging biomarkers may revolutionize the detection and monitoring of placental hypoxia, improving pregnancy outcomes and reducing long-term health complications. This review describes current research on molecular and imaging biomarkers of placental hypoxia both in human and animal studies and aims to explore the benefits of an integrated approach throughout gestation.

NCOA2-induced secretion of leptin leads to fetal growth restriction via the NF-κB signaling pathway

Background

Fetal growth restriction (FGR) is one of the most common fetal complications during pregnancy in the obstetrics department, with poor therapeutic efficacy. The local inflammatory response of the placenta has gradually become known as the main mechanism for the occurrence and development of FGR. The aim of this study was to improve the knowledge of placental inflammatory response mechanisms in regulating gene expression.

Methods

The differentially expressed genes (DEGs) in FGR patients were analyzed through bioinformatics analysis. The expression of gene level was detected by immunohistochemistry (IHC) staining, quantitative polymerase chain reaction (qPCR), or enzyme-linked immunosorbent assay (ELISA). The proliferation, migration, and apoptosis of HTR-8/SVneo trophoblast cells stimulated with lipopolysaccharide (LPS) was performed by Cell Counting Kit-8 (CCK-8) assay, clone formation assay, Transwell assay, and flow cytometry. The mechanisms of gene expression in regulating placental inflammatory response were elucidated by western blotting.

Results

Nuclear receptor coactivator 2 (NCOA2) was identified as a very critical gene in the progression of FGR by bioinformatics analysis and the expression of NCOA2 was shown to be down-regulated in FGR patients. Overexpression of NCOA2 promoted the proliferation, migration, and inhibited apoptosis and pro-inflammatory cytokines secretion in HTR-8/SVneo trophoblast cells stimulated with LPS via the nuclear factor (NF)-κB pathway. In addition, leptin was increased in both tissue and peripheral blood samples of FGR patients, and overexpression of NCOA2 inhibited the secretion of leptin in HTR-8/SVneo trophoblast cells stimulated with LPS.

Conclusions

All these findings suggest that NCOA2-induced secretion of leptin leads to FGR progression via the NF-κB pathway and provides a clinical therapeutic target in FGR and a potent marker for the identification of FGR.

Cross-Generational Impact of Innate Immune Memory Following Pregnancy Complications

Pregnancy complications can have long-term negative effects on the health of the affected mothers and their children. In this review, we highlight the underlying inflammatory etiologies of common pregnancy complications and discuss how aberrant inflammation may lead to the acquisition of innate immune memory. The latter can be described as a functional epigenetic reprogramming of innate immune cells following an initial exposure to an inflammatory stimulus, ultimately resulting in an altered response following re-exposure to a similar inflammatory stimulus. We propose that aberrant maternal inflammation associated with complications of pregnancy increases the cross-generational risk of developing noncommunicable diseases (i.e., pregnancy complications, cardiovascular disease, and metabolic disease) through a process mediated by innate immune memory. Elucidating a role for innate immune memory in the cross-generational health consequences of pregnancy complications may lead to the development of novel strategies aimed at reducing the long-term risk of disease.

Modeling Trophoblast Cell-Guided Uterine Spiral Artery Transformation in the Rat

The rat possesses hemochorial placentation with deep intrauterine trophoblast cell invasion and trophoblast-guided uterine spiral artery remodeling, which resembles human placentation. Uterine spiral arteries are extensively remodeled to deliver sufficient supply of maternal blood and nutrients to the developing fetus. Inadequacies in these key processes negatively impact fetal growth and development. Recent innovations in genome editing combined with effective phenotyping strategies have provided new insights into placental development. Application of these research approaches has highlighted both conserved and species-specific features of hemochorial placentation. The review provides foundational information on rat hemochorial placental development and function during physiological and pathological states, especially as related to the invasive trophoblast cell-guided transformation of uterine spiral arteries. Our goal is to showcase the utility of the rat as a model for in vivo mechanistic investigations targeting regulatory events within the uterine-placental interface.

Antenatal mesenchymal stromal cell extracellular vesicle treatment preserves lung development in a model of bronchopulmonary dysplasia due to chorioamnionitis

Antenatal stressors such as chorioamnionitis (CA) increase the risk for bronchopulmonary dysplasia (BPD). Studies have shown that experimental BPD can be ameliorated by postnatal treatment with mesenchymal stromal cell-derived extracellular vesicles (MEx). However, the antenatal efficacy of MEx to prevent BPD is unknown. To determine whether antenatal MEx therapy attenuates intrauterine inflammation and preserves lung growth in a rat model of CA-induced BPD. At embryonic day (E)20, rat litters were treated with intra-amniotic injections of saline, endotoxin (ETX) to model chorioamnionitis, MEx, or ETX plus MEx followed by cesarean section delivery with placental harvest at E22. Placental and lung evaluations were conducted at day 0 and day 14, respectively. To assess the effects of ETX and MEx on lung growth in vitro, E15 lung explants were imaged for distal branching. Placental tissues from ETX-exposed pregnancies showed increased expression of inflammatory markers NLRP-3 and IL-1ß and altered spiral artery morphology. In addition, infant rats exposed to intrauterine ETX had reduced alveolarization and pulmonary vessel density (PVD), increased right ventricular hypertrophy (RVH), and decreased lung mechanics. Intrauterine MEx therapy of ETX-exposed pups reduced inflammatory cytokines, normalized spiral artery architecture, and preserved distal lung growth and mechanics. In vitro studies showed that MEx treatment enhanced distal lung branching and increased VEGF and SPC gene expression. Antenatal MEx treatment preserved distal lung growth and reduced intrauterine inflammation in a model of CA-induced BPD. We speculate that MEx may provide a novel therapeutic strategy to prevent BPD due to antenatal inflammation.

Maternal omega-3 fatty acids maintained positive maternal lipids and cytokines profile, and improved pregnancy outcomes of C57BL/6 mice

Omega (n)-3 polyunsaturated fatty acids (PUFA) are known to regulate lipid metabolism and inflammation; however, the regulation of maternal lipid metabolism and cytokines profile by n-3 PUFA during different gestation stages, and its impact on fetal sustainability is not known. We investigated the effects of maternal diet varying in n-3 PUFA prior to, and during gestation, on maternal metabolic profile, placental inflammatory cytokines, and fetal outcomes. Female C57BL/6 mice were fed either a high, low or very low (9, 3 or 1% w/w n-3 PUFA) diet, containing n-6:n-3 PUFA of 5:1, 20:1 and 40:1, respectively for two weeks before mating, and throughout pregnancy. Animals were sacrificed prior to mating (NP), and during pregnancy at gestation days 6.5, 12.5 and 18.5. Maternal metabolic profile, placental cytokines and fetal outcomes were determined. Our results show for the first time that a maternal diet high in n-3 PUFA prevented dyslipidemia in NP mice, and maintained the expected lipid profile during pregnancy. However, females fed the very low n-3 PUFA diet became hyperlipidemic prior to pregnancy, and carried this profile into pregnancy. Maternal diet high in n-3 PUFA maintained maternal plasma progesterone and placental pro-inflammatory cytokines profile, and sustained fetal numbers throughout pregnancy, while females fed the low and very-low n-3 PUFA diet had fewer fetuses. Our findings demonstrate the importance of maternal diet before, and during pregnancy, to maintain maternal metabolic profile and fetus sustainability. These findings are important when designing dietary strategies to optimize maternal metabolism during pregnancy for successful pregnancy outcome.

Protective role of IL33 signaling in negative pregnancy outcomes associated with lipopolysaccharide exposure

Interleukin 33 (IL33) signaling has been implicated in the establishment and maintenance of pregnancy and in pregnancy disorders. The goal of this project was to evaluate the role of IL33 signaling in rat pregnancy. The rat possesses hemochorial placentation with deep intrauterine trophoblast invasion; features also characteristic of human placentation. We generated and characterized a germline mutant rat model for IL33 using CRISPR/Cas9 genome editing. IL33 deficient rats exhibited deficits in lung responses to an inflammatory stimulus (Sephadex G-200) and to estrogen-induced uterine eosinophilia. Female rats deficient in IL33 were fertile and exhibited pregnancy outcomes (gestation length and litter size) similar to wild-type rats. Placental weight was adversely affected by the disruption of IL33 signaling. A difference in pregnancy-dependent adaptations to lipopolysaccharide (LPS) exposure was observed between wild-type and IL33 deficient pregnancies. Pregnancy in wild-type rats treated with LPS did not differ significantly from pregnancy in vehicle-treated wild-type rats. In contrast, LPS treatment decreased fetal survival rate, fetal and placental weights, and increased fetal growth restriction in IL33 deficient rats. In summary, a new rat model for investigating IL33 signaling has been established. IL33 signaling participates in the regulation of placental development and protection against LPS-induced fetal and placental growth restriction.

A new mixed model of periodontitis-induced preeclampsia: A pilot study

OBJECTIVES/BACKGROUND

Recent studies have shown that periodontal disease is strongly related to gestational complications such as preeclampsia (PE). PE is responsible for 42% of maternal deaths worldwide and kills approximately 76 000 women a year. In addition, children born under PE conditions are at increased risk of hospitalization due to metabolic disorders, epilepsy, and other complications. Numerous reviews and clinical studies on PE have been published, but the mechanisms underlying the relationship between periodontal disease and PE and the way periodontopathogens alter vascular response in pregnant women remain unclear.

METHODS

This study aims to verify whether periodontal disease induces PE by using the association of two periodontitis (PD) models: ligature and oral Porphyromonas gingivalis (P. gingivalis) W83 inoculation in Wistar rats. At gestational day 5, the ligature was placed on each mandibular first molar, which was followed by daily oral P. gingivalis inoculation for 15 days. At gestational day 19, urine was collected, and invasive arterial pressure was measured. The animals were euthanized, and plasma and tissues were collected.

RESULTS

After 15 days of the association of ligature and P. gingivalis inoculation, the animals presented the characteristic symptoms of PE: altered blood pressure, proteinuria, and change in litter size (number of pups) and pup weight when compared to the control group (p < .005). The PE animals also presented greater bone porosity, trabecular separation, and reduced bone volume in the hemimandibles, as well as altered inflammatory response. The level of cytokine IL-6 was higher in the PE group than in the control group (p < .005).

CONCLUSION

The association of two PD models effectively induced PE. To our knowledge, this is the first study on the oral use of P. gingivalis for PE induction. Our results support the importance of PD as a possible cause for PE development, opening an important new avenue to study cause and consequence relationships in inflammation and PE due to exposure to periodontal infection.

Integrated Analysis of Key Genes and Pathways Involved in Fetal Growth Restriction and Their Associations With the Dysregulation of the Maternal Immune System

Fetal growth restriction (FGR) is a common pregnancy complication and a risk factor for infant death. Most patients with FGR have preeclampsia, gestational diabetes mellitus, or other etiologies, making it difficult to determine the specific molecular mechanisms underlying FGR. In this study, an integrated analysis was performed using gene expression profiles obtained from Gene Expression Omnibus. Differentially expressed genes (DEGs) between healthy and FGR groups were screened and evaluated by functional enrichment and network analyses. In total, 80 common DEGs (FDR < 0.05) and 17 significant DEGs (FDR < 0.005) were screened. These genes were enriched for functions in immune system dysregulation in the placenta based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Among hub genes identified as candidates for FGR and fetal reprogramming, LEP, GBP5, HLA–DQA1, and CTGF were checked by quantitative polymerase chain reaction, immunohistochemistry, and western blot assays in placental tissues. Immune imbalance could cause hypoxia environment in placenta tissues, thus regulating the fetal-reprogramming. A significant association between CTGF and HIF-1α levels was confirmed in placenta tissues and HTR8 cells under hypoxia. Our results suggest that an immune imbalance in the placenta causes FGR without other complications. We provide the first evidence for roles of CTGF in FGR and show that CTGF may function via HIF-1α-related pathways. Our findings elucidate the pathogenesis of FGR and provide new therapeutic targets.

Perinatal Hypoxia-Inducible Factor Stabilization Preserves Lung Alveolar and Vascular Growth in Experimental Bronchopulmonary Dysplasia

Rationale: Antenatal inflammation with placental dysfunction is strongly associated with high bronchopulmonary dysplasia (BPD) risk in preterm infants. Whether antenatal or postnatal HIF (hypoxia-inducible factor) augmentation can preserve lung structure and function and prevent pulmonary hypertension after intrauterine inflammation is controversial.Objectives: To determine whether antenatal or postnatal prolyl-hydroxylase inhibitor (PHi) therapy increases lung HIF expression, preserves lung growth and function, and prevents pulmonary hypertension in a rat model of chorioamnionitis-induced BPD caused by antenatal inflammation.Methods: Endotoxin (ETX) was administered to pregnant rats by intraamniotic injection at Embryonic Day 20, and pups were delivered by cesarean section at Embryonic Day 22. Selective PHi drugs, dimethyloxalylglycine or GSK360A, were administered into the amniotic space at Embryonic Day 20 or after birth by intraperitoneal injection for 2 weeks. Placentas and lung tissue were collected at birth for morphometric and Western blot measurements of HIF-1a, HIF-2a, VEGF (vascular endothelial growth factor), and eNOS (endothelial nitric oxide synthase) protein contents. At Day 14, lung function was assessed, and tissues were harvested to determine alveolarization by radial alveolar counts, pulmonary vessel density, and right ventricle hypertrophy (RVH).Measurements and Main Results: Antenatal PHi therapy preserves lung alveolar and vascular growth and lung function and prevents RVH after intrauterine ETX exposure. Antenatal administration of PHi markedly upregulates lung HIF-1a, HIF-2a, VEGF, and eNOS expression after ETX exposure.Conclusions: HIF augmentation improves lung structure and function, prevents RVH, and improves placental structure following antenatal ETX exposure. We speculate that antenatal or postnatal PHi therapy may provide novel strategies to prevent BPD due to antenatal inflammation.

Novel relationships between porcine fetal size, sex, and endometrial angiogenesis†

It is hypothesized that growth restriction occurs due to inadequate vascularization of the feto-maternal interface. Evidence exists for sexual dimorphism in placental function although associations between fetal sex and the endometrium remain poorly investigated. This study investigated the relationship between porcine fetal size, sex and endometrial angiogenesis at multiple gestational days (GD). Endometrial samples supplying the lightest and closest to mean litter weight (CTMLW), male and female Large White X Landrace conceptuses or fetuses were obtained at GD18, 30, 45, 60, and 90 (n = 5-9 litters/GD). Immunohistochemistry for CD31 revealed a greater number of blood vessels in endometrium supplying females compared to those supplying males at GD45. Endometrial samples supplying the lightest fetuses had fewer blood vessels (GD60) and uterine glands (GD90) compared to those supplying the CTMLW fetuses. Quantitative PCR revealed decreased CD31 (GD60), HPSE and VEGFA (GD90) expression, alongside increased HIF1A (GD45) expression in endometrial samples supplying the lightest compared to the CTMLW fetuses. At GD30, PTGFR, CD31, and VEGFA mRNA expression was increased in samples supplying female fetuses compared to those supplying male fetuses. Intriguingly, decreased expression of ACP5, CD31, HIF1A, and VEGFA mRNAs was observed at GD60 in endometrial samples supplying female fetuses compared to those supplying their male littermates. Endothelial cell branching assays demonstrated impaired endothelial cell branching in response to conditioned media from endometrial samples supplying the lightest and female fetuses compared with the CTMLW and male fetuses, respectively. This study has highlighted that endometrial tissues supplying the lightest and female fetuses have impaired angiogenesis when compared with the CTMLW and female fetuses respectively. Importantly, the relationship between fetal size, sex and endometrial vascularity is dynamic and dependent upon the GD investigated.

Maternal Obesity and the Uterine Immune Cell Landscape: The Shaping Role of Inflammation

Inflammation is often equated to the physiological response to injury or infection. Inflammatory responses defined by cytokine storms control cellular mechanisms that can either resolve quickly (i.e., acute inflammation) or remain prolonged and unabated (i.e., chronic inflammation). Perhaps less well-appreciated is the importance of inflammatory processes central to healthy pregnancy, including implantation, early stages of placentation, and parturition. Pregnancy juxtaposed with disease can lead to the perpetuation of aberrant inflammation that likely contributes to or potentiates maternal morbidity and poor fetal outcome. Maternal obesity, a prevalent condition within women of reproductive age, associates with increased risk of developing multiple pregnancy disorders. Importantly, chronic low-grade inflammation is thought to underlie the development of obesity-related obstetric and perinatal complications. While diverse subsets of uterine immune cells play central roles in initiating and maintaining healthy pregnancy, uterine leukocyte dysfunction as a result of maternal obesity may underpin the development of pregnancy disorders. In this review we discuss the current knowledge related to the impact of maternal obesity and obesity-associated inflammation on uterine immune cell function, utero-placental establishment, and pregnancy health.

Circular RNA hsa_circ_0000848 Promotes Trophoblast Cell Migration and Invasion and Inhibits Cell Apoptosis by Sponging hsa-miR-6768-5p

Background

Fetal growth restriction (FGR) is a worldwide problem, and a major cause of perinatal morbidity. The precise molecular mechanisms involved in placental development and function during FGR remain poorly understood. Circular RNAs (circRNAs) are important biological molecules associated with disease pathogenesis. However, the role of circRNAs in FGR has not been well studied.

Methods

circRNA expression profiles in placental tissues with and without FGR were identified by circRNA microarray. circRNA expression was verified by quantitative reverse-transcription PCR (RT-qPCR) assay. The effect of hsa_circ_0000848 and hsa-miR-6768-5p on HTR-8 cell apoptosis, migration, and invasion was evaluated. The association between hsa_circ_0000848 and hsa-miR-6768-5p was confirmed by dual luciferase activity and anti-AGO2 RNA immunoprecipitation (RIP) assays. Protein levels were examined via western blotting.

Results

RT-qPCR results showed that hsa_circ_0000848 expression was significantly down-regulated in FGR placenta. Hsa_circ_0000848 overexpression and hsa-miR-6768-5p inhibitor suppressed apoptosis, and promoted cell migration and invasion. In addition, hsa_circ_0000848 overexpression and hsa-miR-6768-5p inhibitor increased the protein abundance of BCL2, MMP2 and MMP9, and decreased the protein abundance of cleaved caspase-3, cleaved caspase-9, and BAX, whereas hsa_circ_0000848 knockdown caused the opposite effect. Moreover, a significant increase in hsa-miR-6768-5p expression and a negative correlation between hsa_circ_0000848 and hsa-miR-6768-5p were identified in the FGR tissues. Luciferase reporter and RIP assay results revealed binding of hsa-miR-6768-5p to hsa_circ_0000848. Furthermore, hsa-miR-6768-5p overexpression eliminated the effect of hsa_circ_0000848 overexpression in HTR-8 cells.

Conclusions

hsa_circ_0000848 expression is significantly down-regulated in the FGR placenta. hsa_circ_0000848 promotes trophoblast cell migration and invasion, and inhibits cell apoptosis via the sponging of hsa-miR-6768-5p. Our study provided a novel insight into mechanisms underlying the pathogenesis of FGR, as well as into new strategies for the treatment of FGR.

Aberrant hydroxymethylation of ANGPTL4 is associated with selective intrauterine growth restriction in monochorionic twin pregnancies

Selective intrauterine growth restriction (sIUGR) is a severe complication in monochorionic (MC) twin pregnancies, and it carries increased risks of poor prognosis. Current data suggest that vascular anastomoses and unequal placental sharing may be the key contributor to discordant foetal growth. While MC twins derive from a single zygote and have almost identical genetic information, the precise mechanisms remain unknown. DNA hydroxymethylation is a newly discovered epigenetic feature associated with gene regulation and modification. Here, we investigate discordant hydroxymethylation patterns between two placental shares of sIUGR and analyse the potential role of aberrant hydroxymethylation of angiopoietin-like 4 (ANGPTL4) in placental dysplasia. Hydroxymethylation DNA immunoprecipitation (hMeDIP)-chip and mRNA sequencing were performed to identify hydroxymethylation-associated genes. Real-time qPCR, western blotting, and immunohistochemistry were used to confirm ANGPTL4 expression. The mechanisms regulating ANGPTL4 were investigated by cell migration assay, invasion assay, viability assay, and apoptotic ratio assays, western blotting and hMeDIP-qPCR. Decreased ANGPTL4 was detected in the smaller placental shares of sIUGR. ANGPTL4 knockdown suppressed trophoblast invasiveness and migration, which possibly occurred through hypoxia inducible factor 1α (HIF-1α) and HIF-1 signalling pathway. Hypoxia leads to aberrant expression of ANGPTL4 and HIF-1α, positively correlated with their aberrant hydroxymethylation levels in promoter regions. Aberrant hydroxymethylation of ANGPTL4 may contribute to placental impairment by the HIF-1 signalling pathway in smaller placental shares of sIUGR.

Direct Peritoneal Resuscitation with Pyruvate Protects the Spinal Cord and Induces Autophagy via Regulating PHD2 in a Rat Model of Spinal Cord Ischemia-Reperfusion Injury

Direct peritoneal resuscitation with pyruvate (Pyr-PDS) has emerged as an interesting candidate to alleviate injury in diverse organs, while the potential mechanism has yet to be fully elucidated. To explore the effect of autophagy in the spinal cord ischemia-reperfusion (SCIR) injury and the underlying mechanism, we established a model of SCIR in vivo and in vitro. In vivo, male SD rats underwent aortic occlusion for 60 min and then followed by intraperitoneally infused with 20 mL of pyruvate or normal saline for 30 min, and the spinal cords were removed for analysis after 48 h of reperfusion. The functional and morphological results showed that Pyr-PDS alleviated SCIR injury; meanwhile, the expression of autophagy-related genes and transmission electron microscopy displayed autophagy was activated by SCIR injury, and Pyr-PDS treatment could further upregulate the degree of autophagy which plays a protective part in the SCIR injury, while there is no significant difference after treatment with saline. In addition, SCIR injury inhibited expression of PHD2, which results to activate its downstream HIF-1α/BNIP3 pathway to promote autophagy. In the Pyr-PDS, the results revealed PHD2 was further inhibited compared to the SCIR group, which could further activate the HIF-1α/BNIP3 signaling pathway. Additionally, oxygen-glucose deprivation and reoxygenation were applied to SH-SY5Y cells to mimic anoxic conditions in vitro, and the expression of autophagy-related genes, PHD2, and its downstream HIF-1α/BNIP3 pathway showed the same trend as the results in vivo. Besides, IOX2, a specific inhibitor of PHD2 was also treated to SH-SY5Y cells during reoxygenation, in which the result is as same as the pyruvate group. Then, we observed the expression of autophagy-related genes and the HIF-1α signal pathway in the process of reoxygenation; the results showed that as the reoxygenation goes, the expression of the HIF-1α signal pathway and degree of autophagy came to decrease gradually, while treated with pyruvate could maintain autophagy high and stable through keeping PHD2 at a lower level during reoxygenation, and the latter was observed downregulated during reoxygenation process from 0 to 24 hours in a time-effect way. The above results indicated that direct peritoneal resuscitation with pyruvate showed effective protection to ischemia-reperfusion of the spinal cord through activating autophagy via acting on PHD2 and its downstream HIF-1α/BNIP3 pathway.

Se deficiency induces renal pathological changes by regulating selenoprotein expression, disrupting redox balance, and activating inflammation

Selenium (Se) is closely associated with kidney disease, and renal injury often occurs together with hyposelenemia. This study was designed to reveal the mechanism underlying renal injury induced by Se deficiency in pigs. Twenty-four castrated male Yorkshire pigs were divided into two groups fed either a Se-deficient diet (0.007 mg Se per kg) or a Se-adequate diet (0.3 mg Se per kg). Serum and kidney samples were collected at the 16th week of the trial, processed, and analyzed for serum biochemistry, Se concentration, kidney index markers, histology, selenoprotein mRNA expression, redox status, and inflammatory cytokines. Dietary Se deficiency induced kidney injury, decreased (P < 0.05) Se concentrations, and increased (P < 0.05) kidney index and serum blood urea nitrogen, creatinine, and carbon dioxide values. Histological analysis indicated that Se deficiency induced inflammatory lesions and renal tubular atrophy in the renal medulla. Se deficiency downregulated (P < 0.05) nine selenoprotein genes (GPX1, SELENOW, SELENOH, SELENOP, GPX3, TXNRD2, SELENOI, SELENON, and SELENOM) and upregulated (P < 0.05) SEPHS2 in the kidneys. Se deficiency decreased (P < 0.05) the activity of glutathione peroxidase, thioredoxin reductase, and catalase, as well as the hydroxyl radical inhibition capacity, and increased (P < 0.05) the content of malondialdehyde and nitric oxide. Se deficiency increased (P < 0.05) the expression of the transcription factors NF-κB and HIF-1α, and regulated inflammatory cytokines. Se deficiency increased (P < 0.05) the expression of IL-6, IL-8, IL-12, IL-17, and cyclooxygenase-2, and decreased (P < 0.05) the expression of IL-10, IL-13, and TGF-β. These results indicated that Se deficiency induces kidney injury through the regulation of selenoproteins, oxidative stress, and inflammation.

Models of Intrauterine growth restriction and fetal programming in rabbits

Intrauterine growth restriction (IUGR) affects approximately 10% of human pregnancies globally and has immediate and life-long consequences for offspring health. However, the mechanisms underlying the pathogenesis of IUGR and its association with later health and disease outcomes are poorly understood. To address these knowledge gaps, the use of experimental animals is critically important. Since the 50's different environmental, pharmacological, and surgical manipulations have been performed in the rabbit to improve our knowledge of the control of fetal growth, fetal responses to IUGR, and mechanisms by which offspring may be programmed by an adverse gestational environment. The purpose of this review is therefore to summarize the utility of the rabbit as a model for IUGR research. It first summarizes the knowledge of prenatal and postnatal development in the rabbit and how these events relate to developmental milestones in humans. It then describes the methods used to induce IUGR in rabbits and the knowledge gained about the mechanisms determining prenatal and postnatal outcomes of the offspring. Finally, it discusses the application of state of the art approaches in the rabbit, including high-resolution ultrasound, magnetic resonance imaging, and gene targeting, to gain a deeper integrative understanding of the physiological and molecular events governing the development of IUGR. Overall, we hope to engage and inspire investigators to employ the rabbit as a model organism when studying pregnancy physiology so that we may advance our understanding of mechanisms underlying IUGR and its consequences in humans and other mammalian species.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Trophoblast-Specific Expression of Hif-1α Results in Preeclampsia-Like Symptoms and Fetal Growth Restriction

The placenta is an essential organ that is formed during pregnancy and its proper development is critical for embryonic survival. While several animal models have been shown to exhibit some of the pathological effects present in human preeclampsia, these models often do not represent the physiological aspects that have been identified. Hypoxia-inducible factor 1 alpha (Hif-1α) is a necessary component of the cellular oxygen-sensing machinery and has been implicated as a major regulator of trophoblast differentiation. Elevated levels of Hif-1α in the human placenta have been linked to the development of pregnancy-associated disorders, such as preeclampsia and fetal growth restriction. As oxygen regulation is a critical determinant for placentogenesis, we determined the effects of constitutively active Hif-1α, specifically in trophoblasts, on mouse placental development in vivo. Our research indicates that prolonged expression of trophoblast-specific Hif-1α leads to a significant decrease in fetal birth weight. In addition, we noted significant physiological alterations in placental differentiation that included reduced branching morphogenesis, alterations in maternal and fetal blood spaces, and failure to remodel the maternal spiral arteries. These placental alterations resulted in subsequent maternal hypertension with parturitional resolution and maternal kidney glomeruloendotheliosis with accompanying proteinuria, classic hallmarks of preeclampsia. Our findings identify Hif-1α as a critical molecular mediator of placental development and indicate that prolonged expression of Hif-1α, explicitly in placental trophoblasts causes maternal pathology and establishes a mouse model that significantly recapitulates the physiological and pathophysiological characteristics of preeclampsia with fetal growth restriction.

HIF-1α-Deficiency in Myeloid Cells Leads to a Disturbed Accumulation of Myeloid Derived Suppressor Cells (MDSC) During Pregnancy and to an Increased Abortion Rate in Mice

Abortions are the most important reason for unintentional childlessness. During pregnancy, maternal immune cells are in close contact to cells of the semi-allogeneic fetus. Dysregulation of the maternal immune system leading to defective adaptation to pregnancy often plays a role in pathogenesis of abortions. Myeloid-derived suppressor cells (MDSC) are myeloid cells that suppress functions of other immune cells, especially T-cells, thereby negatively affecting diseases such as cancer, sepsis or trauma. They seem, however, also necessary for maintenance of maternal-fetal tolerance. Mechanisms regulating MDSC expansion and function during pregnancy are only incompletely understood. In tumor environment, hypoxia is crucial for MDSC accumulation and activation. Hypoxia is also important for early placenta and embryo development. Effects of hypoxia are mediated through hypoxia-inducible factor 1α (HIF-1α). In the present study we aimed to examine the role of HIF-1α in myeloid cells for MDSC accumulation and MDSC function during pregnancy and for pregnancy outcome. We therefore used a mouse model with targeted deletion of HIF-1α in myeloid cells (myeloid HIF-KO) and analyzed blood, spleens and uteri of pregnant mice at gestational day E 10.5 in comparison to non-pregnant animals and wildtype (WT) animals. Further we analyzed pregnancy success by determining rates of failed implantation and abortion in WT and myeloid HIF-KO animals. We found that myeloid HIF-KO in mice led to an abrogated MDSC accumulation in the pregnant uterus and to impaired suppressive activity of MDSC. While expression of chemokine receptors and integrins on MDSC was not affected by HIF-1α, myeloid HIF-KO led to increased apoptosis rates of MDSC in the uterus. Myeloid-HIF-KO resulted in increased proportions of non-pregnant animals after positive vaginal plug and increased abortion rates, suggesting that activation of HIF-1α dependent pathways in MDSC are important for maintenance of pregnancy.

Associations between fetal size, sex and placental angiogenesis in the pig

Inadequate fetal growth cannot be remedied postnatally, leading to severe consequences for neonatal and adult development. It is hypothesized that growth restriction occurs due to inadequate placental vascularization. This study investigated the relationship between porcine fetal size, sex, and placental angiogenesis at multiple gestational days (GD). Placental samples supplying the lightest and closest to mean litter weight (CTMLW), male and female Large White X Landrace fetuses were obtained at GD30, 45, 60, and 90. Immunohistochemistry revealed increased chorioallantoic membrane CD31 staining in placentas supplying the lightest compared to those supplying the CTMLW fetuses at GD60. At GD90, placentas supplying the lightest fetuses had decreased CD31 staining in the chorioallantoic membrane compared to those supplying the CTMLW fetuses. The mRNA expression of six candidate genes with central roles at the feto-maternal interface increased with advancing gestation. At GD60, ACP5 expression was increased in placentas supplying the lightest compared to the CTMLW fetuses. At GD45, CD31 expression was decreased in placentas supplying the lightest compared to the CTMLW fetuses. In contrast, CD31 expression was increased in placentas supplying the lightest compared the CTMLW fetuses at GD60. In vitro endothelial cell branching assays demonstrated that placentas supplying the lightest and male fetuses impaired endothelial cell branching compared to placentas from the CTMLW (GD45 and 60) and female fetuses (GD60), respectively. This study has highlighted that placentas supplying the lightest and male fetuses have impaired angiogenesis. Importantly, the relationship between fetal size, sex, and placental vascularity is dynamic and dependent upon the GD investigated.

CD38 affects the biological behavior and energy metabolism of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is the most common malignant tumor type in Southern China and South-East Asia. Cluster of differentiation (CD)38 is highly expressed in the human immune system and participates in the activation of T, natural killer and plasma cells mediated by CD2 and CD3 through synergistic action. CD38 is a type II transmembrane glycoprotein, which was observed to mediate diverse activities, including signal transduction, cell adhesion and cyclic ADP-ribose synthesis. However, the significance of CD38 in NPC biological behavior and cellular energy metabolism has not been examined. In order to elucidate the effect of CD38 on the biological behavior of NPC cells, stable CD38-overexpressed NPC cell lines were established. It was demonstrated that CD38 promoted NPC cell proliferation with Cell Counting Kit-8 and colony formation assays. It was also indicated that CD38 inhibited cell senescence, and promoted cell metastasis. Furthermore, it was determined that CD38 promoted the conversion of cells to the S phase and decreased the content of reactive oxygen species and Ca²⁺. Additionally, cell metabolism assays demonstrated that CD38 increased the concentration of ATP, lactic acid, cyclic adenosine monophosphate and human ADP/acrp30 concentration in NPC cells. To investigate the possible mechanism, bioinformatics analysis and mass spectrometry technology was used to determine the most notably changing molecule and signaling pathways, and it was determined and verified that CD38 regulated the metabolic-associated signaling pathways associated with tumor protein 53, hypoxia inducible factor-1α and sirtuin 1. The present results indicated that CD38 may serve a carcinogenic role in NPC by regulating metabolic-associated signaling pathways.

Hypoxia and Placental Development

Hemochorial placentation is orchestrated through highly regulated temporal and spatial decisions governing the fate of trophoblast stem/progenitor cells. Trophoblast cell acquisition of specializations facilitating invasion and uterine spiral artery remodeling is a labile process, sensitive to the environment, and represents a process that is vulnerable to dysmorphogenesis in pathologic states. Hypoxia is a signal guiding placental development, and molecular mechanisms directing cellular adaptations to low oxygen tension are integral to trophoblast cell differentiation and placentation. Hypoxia can also be used as an experimental tool to investigate regulatory processes controlling hemochorial placentation. These developmental processes are conserved in mouse, rat, and human placentation. Consequently, elements of these developmental events can be modeled and hypotheses tested in trophoblast stem cells and in genetically manipulated rodents. Hypoxia is also a consequence of a failed placenta, yielding pathologies that can adversely affect maternal adjustments to pregnancy, fetal health, and susceptibility to adult disease. The capacity of the placenta for adaptation to environmental challenges highlights the importance of its plasticity in safeguarding a healthy pregnancy. Birth Defects Research 109:1309-1329, 2017.© 2017 Wiley Periodicals, Inc.

Management of Obstructive Sleep Apnea in Pregnancy

The spectrum of sleep-disordered breathing (SDB) ranges from mild snoring to obstructive sleep apnea, the most severe form of SDB. Current recommendations are to treat these women with continuous positive airway pressure despite limited data. SDB in early and mid-pregnancy is associated with preeclampsia and gestational diabetes. Pregnant women with a diagnosis of obstructive sleep apnea at delivery were at significantly increased risk of having cardiomyopathy, congestive heart failure, pulmonary embolism, and in-hospital death. These effects were exacerbated in the presence of obesity. Postpartum, these women are at risk for respiratory suppression and should be monitored.

Persistence of risk factors associated with maternal cardiovascular disease following aberrant inflammation in rat pregnancy

Introduction

Pre-eclampsia is associated with increased risk of subsequent cardiovascular and metabolic disease in the affected mothers. While aberrant inflammation contributes to the pathophysiology of pre-eclampsia, it is unclear whether maternal inflammation contributes to the increased risk of disease. Here, we determined the effect of aberrant inflammation in pregnancy on cardiovascular and metabolic disease risk factors.

Methods

Wistar rats were administered low doses of lipopolysaccharide (LPS) on gestational days (GD) 13.5-16.5 to induce inflammation. Controls included pregnant rats treated with saline and nonpregnant rats treated with LPS or saline. We previously showed that LPS-treated pregnant rats exhibit key features of pre-eclampsia. Echocardiographic parameters, heart weight, blood pressure, blood lipids, pulse-wave velocity, and glucose tolerance, were assessed at 16 weeks postpartum. Messenger RNA levels of transcription factors associated with cardiac growth were measured in left ventricular tissue; histone modifications and global DNA methylation were determined in hearts and livers at GD 17.5 and at 16 weeks postpartum.

Results

Compared with saline-treated pregnant rats and nonpregnant rats treated with LPS or saline, LPS-treated pregnant rats exhibited left ventricular hypertrophy and increased blood cholesterol and low-density lipoprotein levels at 16 weeks postdelivery. LPS-treated rats had increased left ventricular mRNA levels of hypertrophy-associated transcription factors at GD 17.5 and increased levels of modified histones in hearts and livers at GD 17.5 and 16 weeks postpartum. Other parameters remained unchanged.

Conclusion

Aberrant inflammation during pregnancy results in persistent alterations in maternal physiological parameters and epigenetic modifications that could contribute to the pathophysiology of cardiovascular disease.

Placentas from women with pregnancy-associated venous insufficiency show villi damage with evidence of hypoxic cellular stress

Lower extremity venous insufficiency (VI) is a complication of pregnancy. The potential association of this venous disease with structural damage of the placenta has not been described. We analyzed the pattern of histopathologic lesions and the gene and protein expression of HIF1-α and apoptosis regulatory proteins. A prospective study was carried out on placenta samples from 43 women with pregnancy-associated VI and 24 age-matched pregnant healthy controls (HCs). Women with VI showed a significant increase in the number of villi (150.77 ± 42.55 VI versus 122.13 ± 27.74 HC) and in syncytial knots compared with those found in the placentas from HCs (67.15 ± 31.08 VI versus 42.49 ± 17.36 HC), and an increase in the number of bridges (32.40 ± 2.67 VI versus 22.73 ± 2.37 HC; P < .05). The mean number of syncytial nodes per villus is 1.37 ± 0.90 in the VI group and 0.49 ± 0.58 in the HC group (P < .001). Significant increases in the expression of Bax and caspase-3 and caspase-9 in the placentas from women with VI were observed compared with those found in HC. The expression of HIF-1α at both the messenger RNA and protein levels was also significantly increased in the placentas from women with VI. Our study demonstrates that placentas from women with pregnancy-associated VI show structural remodeling, with an increase in the number of villi and syncytial knots and enhanced apoptotic cellular death. Interestingly, this placental damage is associated with an increased expression of hypoxia-triggered molecular pathways, such as HIF-1α.