Effects of fatty acids on angiogenic activity in the placental extravillious trophoblast cells

Vasoactive intestinal peptide induces metabolic rewiring of human-derived cytotrophoblast cells to promote cell migration

The placenta has an extraordinary metabolic rate with high oxygen consumption. Extravillous cytotrophoblast cells (EVT) metabolism and function are critical to sustain their invasive phenotype supporting fetal development. Deficient EVT function underlies pregnancy complications as preeclampsia (PE) and fetal growth restriction (FGR). The vasoactive intestinal peptide (VIP) promotes human cytotrophoblast cell migration and invasion through mTOR signaling pathways suggesting its crucial role during placentation. Here we explored fatty acid uptake as well as lipid and glucose metabolism in human-derived cytotrophoblast cell function upon VIP stimulation. We found that VIP induced long chain fatty acid (LCFAs) uptake along with the expression of FATP2 transporter, CPT1 fatty acid oxidation (FAO)-rate limiting step importer, and lipid droplet accumulation. VIP induced the expression of glucose 6-P-dehydrogenase, a rate-limiting enzyme of the pentose phosphate pathway (PPP) and pyruvate dehydrogenase complex enzyme DLAT E2, without altering lactate secretion. This metabolic rewiring of trophoblast cells induced by VIP takes place without compromising mitochondrial function or reactive oxygen species (ROS) production. Moreover, cytotrophoblast cell migration induced by VIP required the three glycolysis, oxidative phosphorylation (OXPHOS) and FAO pathways. Our results provide evidence supporting VIP as a metabolic regulatory peptide in cytotrophoblast cells sustaining proper placentation and fetal growth.

Maternal fish oil supplementation enhances nutrient transport in the placenta and milk biosynthesis in the mammary gland via the GPR120 signaling pathway

INTRODUCTION

Maternal fish oil (FO) supplementation during pregnancy has been shown to improve pregnancy outcomes. FO is recognized as dietary source for n-3 polyunsaturated fatty acids (n-3 PUFAs). While early research has focused on the benefits of n-3 PUFAs for fetal neurodevelopment, retinal maturation and neonatal behavior, their roles in the placenta during late pregnancy and in the mammary gland during lactation still remain unknow.

OBJECTIVES

Here, we aim to clarify the mechanisms by which maternal supplementation with FO during pregnancy and lactation affects placental and mammary gland function.

METHODS

We evaluated the effects of FO on maternal placental nutrient transport, mammary gland milk synthesis and offspring growth. We then explored the molecular mechanisms by which docosahexaenoic acid (DHA) affects the biological function of placental trophoblast cells and mammary epithelial cells through in vitro experiments. Finally, a lipopolysaccharide-challenged experiment was performed to access the potential of maternal FO supplementation in alleviating offspring intestinal inflammation.

RESULTS

Maternal supplementation with FO during late pregnancy increased offspring birth weight, associated with enhanced maternal placental vascularization and nutrient transporter abundance. Additionally, maternal FO supplementation during lactation improved milk biosynthesis, increasing the fat, protein, and non-fat solids content in both colostrum and mature milk, thereby promoting offspring growth. The stimulatory effects of DHA on nutrient transportation in placental trophoblast cells and nutrient secretion in mammary gland epithelial cells were mediated by GPR120 signaling pathways. Furthermore, maternal FO supplementation strengthened the placental barrier, reduced placental inflammation, oxidative stress and alleviated lipopolysaccharide-induced intestinal inflammation in offspring.

CONCLUSION

Maternal FO supplementation during late pregnancy and lactation enhances offspring growth by increasing placental nutrient transport and milk biosynthesis, mediated by GPR120. Additionally, maternal FO supplementation reduces the susceptibility of offspring to intestinal inflammation.

Pregnancy Metabolic Adaptation and Changes in Placental Metabolism in Preeclampsia

Pregnancy is a unique physiological state in which the maternal body undergoes a series of changes in the metabolism of glucose, lipids, amino acids, and other nutrients in order to adapt to the altered state of pregnancy and provide adequate nutrients for the fetus' growth and development. The metabolism of various nutrients is regulated by one another in order to maintain homeostasis in the body. Failure to adapt to the altered physiological conditions of pregnancy can lead to a range of pregnancy issues, including fetal growth limitation and preeclampsia. A failure of metabolic adaptation during pregnancy is linked to the emergence of preeclampsia. The treatment of preeclampsia by focusing on metabolic changes may provide new therapeutic alternatives.

Expression Profiles of Fatty Acid Transporters and the Role of n-3 and n-6 Polyunsaturated Fatty Acids in the Porcine Endometrium

Fatty acids (FAs) are important for cell membrane composition, eicosanoid synthesis, and metabolic processes. Membrane proteins that facilitate FA transport into cells include FA translocase (also known as CD36) and FA transporter proteins (encoded by SLC27A genes). The present study aimed to examine expression profiles of FA transporters in the endometrium of cyclic and early pregnant gilts on days 3 to 20 after estrus and the possible regulation by conceptus signals and polyunsaturated FAs (PUFAs). The effect of PUFAs on prostaglandin (PG) synthesis and transcript abundance of genes related to FA action and metabolism, angiogenesis, and immune response was also determined. Day after estrus and reproductive status of animals affected FA transporter expression, with greater levels of CD36, SLC27A1, and SLC27A4 observed in pregnant than in cyclic gilts. Conceptus-conditioned medium and/or estradiol-17β stimulated SLC27A1 and CD36 expression. Among PUFAs, linoleic acid decreased SLC27A1 and SLC27A6 mRNA expression, while arachidonic, docosahexaenoic, and eicosapentaenoic acids increased SLC27A4 transcript abundance. Moreover, arachidonic acid stimulated ACOX1, CPT1A, and IL1B expression and increased PGE2 and PGI2 secretion. In turn, α-linolenic acid up-regulated VEGFA, FGF2, FABP4, and PPARG mRNA expression. These results indicate the presence of an active transport of FAs in the porcine endometrium and the role of PUFAs as modulators of the uterine activity during conceptus implantation.

The Research Progress of DNA Methylation in the Development and Function of the Porcine Placenta

The pig is the most widely consumed domestic animal in China, providing over half of the meat supply in food markets. For livestock, a key economic trait is the reproductive performance, which is significantly influenced by placental development. The placenta, a temporary fetal organ, is crucial for establishing maternal-fetal communication and supporting fetal growth throughout pregnancy. DNA methylation is an epigenetic modification that can regulate the gene expression by recruiting proteins involved in gene silencing or preventing transcription factor binding. To enhance our understanding of the molecular mechanisms underlying DNA methylation in porcine placental development, this review summarizes the structure and function of the porcine placenta and the role of DNA methylation in placental development.

Docosahexaenoic acid insufficiency impairs placental angiogenesis by repressing the methylene-bridge fatty acylation of AKT in preeclampsia

INTRODUCTION

Preeclampsia (PE), characterised by hypertension in pregnancy, is regarded as a placental metabolism-related syndrome affecting 5-8% of pregnancies worldwide. The insufficiency of polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA), is a causative factor of PE pathogenesis. However, its molecular aetiology is yet to be comprehensively elucidated.

METHODS

CRISPR/Cas9 was used to construct Fads2 knockout mice. Gas chromatography-mass spectrometry was used to detect placental fatty acid levels. Gene Expression Omnibus was used to analyze placental FADS2 mRNA levels. CCK-8 assay was used to assess cell growth capacity. Cell migration and invasion abilities were measured by transwell and wound healing assay. Tube forming assay was used to test angiogenesis ability. The co-immunoprecipitation assay was used to validate interactions between two proteins. AKT inhibitor MK-2206 and methylene-bridge fatty acylation inhibitor tryptophan were used to rescue experiments.

RESULTS

Compared to those in women with normal pregnancies, the DHA levels in the placentas of patients with PE decreased with the downregulation of FADS2, the key desaturase in the synthesis of PUFAs. Pregnant Fads2+/- mice exhibited PE-like symptoms, including proteinuria and elevated systolic arterial blood pressure, due to defective placental angiogenesis. Mechanistically, FADS2 knockdown in trophoblasts decreased cellular DHA levels and repressed the methylene-bridge fatty-acylation of AKT, inhibiting AKT-VEGFA signalling, which is crucial for angiogenesis.

DISCUSSION

Our results suggest that placental DHA insufficiency downregulates placental angiogenesis via inhibiting fatty acylating AKT and AKT-VEGFA signalling, a novel insight into abnormal fatty acid metabolism in PE.

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.

Erythrocyte fatty acids and desaturase indices in early pregnancy are associated with risk of preeclampsia

Preeclampsia (PE) is a pregnancy disorder that may be associated with inadequate maternal nutrition. Fatty acids are vital for placental and fetal growth. Fatty acid desaturases, key enzymes influencing the metabolism of polyunsaturated fatty acids, are reported to be associated with cardiometabolic risk. Any imbalance in the levels of omega-3 and omega-6 fatty acids can result in increased inflammatory response. The current study reports the levels of erythrocyte fatty acids and desaturase index across gestation in women who develop PE (n = 108) and compares them with non-PE women (n = 216). Maternal erythrocyte fatty acids were measured at 4 time points during pregnancy (i.e., 11-14, 18-22, 26-28 weeks and at delivery) using gas chromatography. Maternal total erythrocyte saturated fatty acids and omega-6/omega-3 fatty acid ratio was higher in the PE group as compared to the non-PE group at 11-14 weeks and 18-22 weeks respectively. Maternal Δ5 desaturase index was lower while Δ6 desaturase index was higher in the PE group at 11-14 and 18-22 weeks. Maternal stearoyl CoA desaturase-18 (SCD-18) index was lower at 11-14 weeks and at delivery. These changes were mainly observed in the early onset PE (EOP) group. Δ6 desaturase index at 11-14 weeks predicted the risk of EOP. Imbalance in fatty acid levels and desaturase indices predate the clinical diagnosis of PE, indicating their role in its pathophysiology. Measurement of fatty acids and desaturase indices in early pregnancy merits evaluation as predictors of risk of PE.

Omega-3 fatty acid supplements and recurrent miscarriage: A perspective on potential mechanisms and clinical evidence

Recurrent miscarriage (RM) affects approximately 1%-5% of couples worldwide. Due to its complicated etiologies, the treatments for RM also vary greatly, including surgery for anatomic factors such as septate uterus and uterine adhesions, thyroid modulation drugs for hyperthyroidism and hypothyroidism, and aspirin and low molecular weight heparin for antiphospholipid syndrome. However, these treatment modalities are still insufficient to solve RM. Omega-3 fatty acids are reported to modulate the dysregulation of immune cells, oxidative stress, endocrine disorders, inflammation, etc., which are closely associated with the pathogenesis of RM. However, there is a lack of a systematic description of the involvement of omega-3 fatty acids in treating RM, and the underlying mechanisms are also not clear. In this review, we sought to determine the potential mechanisms that are highly associated with the pathogenesis of RM and the regulation of omega-3 fatty acids on these mechanisms. In addition, we also highlighted the direct and indirect clinical evidence of omega-3 fatty acid supplements to treat RM, which might encourage the application of omega-3 fatty acids to treat RM, thus improving pregnancy outcomes.

DHA supplementation and pregnancy complications

Docosahexaenoic acid (DHA) supplementation is recommended for women during pregnancy because of its neurological, visual, and cognitive effects. Previous studies have suggested that DHA supplementation during pregnancy may prevent and treat certain pregnancy complications. However, there are contradictions in the current related studies, and the specific mechanism by which DHA acts remains unclear. This review summarizes the research on the relationship between DHA intake during pregnancy and preeclampsia, gestational diabetes mellitus, preterm birth, intrauterine growth restriction, and postpartum depression. Furthermore, we explore the impact of DHA intake during pregnancy on the prediction, prevention, and treatment of pregnancy complications as well as its impact on offspring neurodevelopment. Our results suggest that there is limited and controversial evidence for the protective effect of DHA intake on pregnancy complications, with the exception of preterm birth and gestational diabetes mellitus. However, additional DHA supplementation may improve long-term neurodevelopmental outcomes in the offspring of women with pregnancy complications.

IGF2 May Enhance Placental Fatty Acid Metabolism by Regulating Expression of Fatty Acid Carriers in the Growth of Fetus and Placenta during Late Pregnancy in Pigs

Fatty acids (FAs) are essential substances for the growth and development of the fetus and placenta. The growing fetus and placenta must obtain adequate FAs received from the maternal circulation and facilitated by various placental FA carriers, including FA transport proteins (FATPs), FA translocase (FAT/CD36), and cytoplasmic FA binding proteins (FABPs). Placental nutrition transport was regulated by imprinted genes H19 and insulin-like growth factor 2 (IGF2). Nevertheless, the relationship between the expression patterns of H19/IGF2 and placental fatty acid metabolism throughout pig pregnancy remains poorly studied and unclear. We investigated the placental fatty acid profile, expression patterns of FA carriers, and H19/IGF2 in the placentae on Days 40 (D40), 65 (D65), and 95 (D95) of pregnancy. The results showed that the width of the placental folds and the number of trophoblast cells of D65 placentae were significantly increased than those of D40 placentae. Several important long-chain FAs (LCFAs), including oleic acid, linoleic acid, arachidonatic acid, eicosapentaenoic acid, and docosatetraenoic acid, in the pig placenta showed dramatically increased levels throughout pregnancy. The pig placenta possessed higher expression levels of CD36, FATP4, and FABP5 compared with other FA carriers, and their expression levels had significantly upregulated 2.8-, 5.6-, and 12.0-fold from D40 to D95, respectively. The transcription level of IGF2 was dramatically upregulated and there were corresponding lower DNA methylation levels in the IGF2 DMR2 in D95 placentae relative to D65 placentae. Moreover, in vitro experimentation revealed that the overexpression of IGF2 resulted in a significant increase in fatty acid uptake and expression levels of CD36, FATP4, and FABP5 in PTr2 cells. In conclusion, our results indicate that CD36, FATP4, and FABP5 may be important regulators that enhance the transport of LCFAs in the pig placenta and that IGF2 may be involved in FA metabolism by affecting the FA carriers expression to support the growth of the fetus and placenta during late pregnancy in pigs.

Maternal PUFAs, Placental Epigenetics, and Their Relevance to Fetal Growth and Brain Development

Dietary polyunsaturated fatty acids (PUFAs), especially omega-3 (n-3) and n-6 long-chain (LC) PUFAs, are indispensable for the fetus' brain supplied by the placenta. Despite being highly unsaturated, n-3 LCPUFA-docosahexaenoic acid (DHA) plays a protective role as an antioxidant in the brain. Deficiency of DHA during fetal development may cause irreversible damages in neurodevelopment programming. Dietary PUFAs can impact placental structure and functions by regulating early placentation processes, such as angiogenesis. They promote remodeling of uteroplacental architecture to facilitate increased blood flow and surface area for nutrient exchange. The placenta's fatty acid transfer depends on the uteroplacental vascular development, ensuring adequate maternal circulatory fatty acids transport to fulfill the fetus' rapid growth and development requirements. Maternal n-3 PUFA deficiency predominantly leads to placental epigenetic changes than other fetal developing organs. A global shift in DNA methylation possibly transmits epigenetic instability in developing fetuses due to n-3 PUFA deficiency. Thus, an optimal level of maternal omega-3 (n-3) PUFAs may protect the placenta's structural and functional integrity and allow fetal growth by controlling the aberrant placental epigenetic changes. This narrative review summarizes the recent advances and underpins the roles of maternal PUFAs on the structure and functions of the placenta and their relevance to fetal growth and brain development.

Identification of Diagnostic Markers in Infantile Hemangiomas

Background

Infantile Hemangiomas (IHs) are common benign vascular tumors of infancy that may have serious consequences. The research on diagnostic markers for IHs is scarce.

Methods

The "limma" R package was applied to identify differentially expressed genes (DEGs) in developing IHs. Plugin ClueGO in Cytoscape software performed functional enrichment of DEGs. The Search Tool for Retrieving Interacting Genes (STRING) database was utilized to construct the PPI network. The least absolute shrinkage and selection operator (LASSO) regression model and support vector machine recursive feature elimination (SVM-RFE) analysis were used to identify diagnostic genes for IHs. The receiver operating characteristic (ROC) curve evaluated diagnostic genes' discriminatory ability. Single-gene based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was conducted by Gene Set Enrichment Analysis (GSEA). The chemicals related to the diagnostic genes were excavated by the Comparative Toxicogenomics Database (CTD). Finally, the online website Network Analyst was used to predict the transcription factors targeting the diagnostic genes.

Results

A total of 205 DEGs were singled out from IHs samples of 6-, 12-, and 24-month-old infants. These genes principally participated in vasculogenesis and development-related, endothelial cell-related biological processes. Then we mined 127 interacting proteins and created a network with 127 nodes and 251 edges. Furthermore, LASSO and SVM-RRF algorithms identified five diagnostic genes, namely, TMEM2, GUCY1A2, ISL1, WARS, and STEAP4. ROC curve analysis results indicated that the diagnostic genes had a powerful ability to distinguish IHs samples from normal samples. Next, the results of GSEA for a single gene illustrated that all five diagnostic genes inhibited the "valine, leucine, and isoleucine degradation" pathway in the development of IHs. WARS, TMEM2, and STEAP4 activated the "blood vessel development" and "vasculature development" in IHs. Subsequently, inhibitors targeting TMEM2, GUCY1A2, ISL1, and STEAP4 were mined. Finally, 14 transcription factors regulating GUCY1A2, 14 transcription factors regulating STEAP4, and 26 transcription factors regulating ISL1 were predicted.

Conclusion

This study identified five diagnostic markers for IHs and further explored the mechanisms and targeting drugs, providing a basis for diagnosing and treating IHs.

Comprehensive Metabolomic Profiling of Cord Blood and Placental Tissue in Surviving Monochorionic Twins Complicated by Twin-Twin Transfusion Syndrome With or Without Fetoscopic Laser Coagulation Surgery: A Retrospective Cohort Study

Objectives: To investigate metabolomic perturbations caused by twin-twin transfusion syndrome, metabolic changes associated with fetoscopic laser coagulation in both placental tissue and cord plasma, and to investigate differential metabolites pertinent to varying fetal outcomes, including hemodynamic status, birth weight, and cardiac function, of live-born babies.

Methods: Placental tissue and cord plasma samples from normal term or uncomplicated preterm-born monochorionic twins and those complicated by twin-twin transfusion syndrome treated with or without fetoscopic laser coagulation were analyzed by high-performance liquid chromatography metabolomic profiling. Sixteen comparisons of different co-twin groups were performed. Partial least squares–discriminant analysis, metabolic pathway analysis, biomarker analysis, and Spearman’s correlation analysis were conducted based on differential metabolites used to determine potential biomarkers in different comparisons and metabolites that are pertinent to neonatal birth weight and left ventricular ejection fraction.

Results: These metabolomic investigations showed that the cord plasma metabolome has a better performance in discriminating fetuses among different hemodynamic groups than placental tissue. The metabolic alteration of twin-twin transfusion syndrome in these two types of samples centers on fatty acid and lipid metabolism. The fetoscopic laser coagulation procedure improves the metabolomic change brought by this syndrome, making the metabolomes of the treated group less distinguishable from those of the control and preterm birth groups. Certain compounds, especially lipids and lipid-like molecules, are noted to be potential biomarkers of this morbid disease and pertinent to neonatal birth weight and ejection fraction.

Conclusions: Fetoscopic laser coagulation can ameliorate the metabolomic alteration caused by twin-twin transfusion syndrome in placental tissue and cord plasma, which are involved mainly in fatty acid and lipid-like molecule metabolism. Certain lipids and lipid-like molecules are helpful in differentiating co-twins of different hemodynamic statuses and are significantly correlated with neonatal birth weight or ejection fraction.

Maternal Fatty Acid Metabolism in Pregnancy and Its Consequences in the Feto-Placental Development

During pregnancy, maternal plasma fatty acids are critically required for cell growth and development, cell signaling, and the development of critical structural and functional aspects of the feto-placental unit. In addition, the fatty acids modulate the early stages of placental development by regulating angiogenesis in the first-trimester human placenta. Preferential transport of maternal plasma long-chain polyunsaturated fatty acids during the third trimester is critical for optimal fetal brain development. Maternal status such as obesity, diabetes, and dietary intakes may affect the functional changes in lipid metabolic processes in maternal-fetal lipid transport and metabolism. Fatty acids traverse the placental membranes via several plasma membrane fatty acid transport/binding proteins (FAT, FATP, p-FABPpm, and FFARs) and cytoplasmic fatty acid-binding proteins (FABPs). This review discusses the maternal metabolism of fatty acids and their effects on early placentation, placental fatty acid transport and metabolism, and their roles in feto-placental growth and development. The review also highlights how maternal fat metabolism modulates lipid processing, including transportation, esterification, and oxidation of fatty acids.

Effects of palmitic acid and eicosapentaenoic acid on angiogenesis of porcine vascular endothelial cells

Restricted placental angiogenesis is an important cause of intrauterine growth retardation in piglets. During pregnancy, sow obesity can result in an increase in placental lipid deposition, subsequently inhibiting placental angiogenesis and fetal development. However, the effect of different types of fatty acids on placental angiogenesis is still unclear. Trophoblast cells and vascular endothelial cells constitute two important types of placental tissue. In this study, we used palmitic acid (C16:0) and eicosapentaenoic acid (C20:5, n-3), respectively, to treat porcine trophectoderm cells (pTr2) and porcine iliac artery endothelial cells (PIEC) to study the effects of saturated fatty acids and n-3 polyunsaturated fatty acids (PUFAs) on placental angiogenesis in vitro. We found that C16:0 caused significant cytotoxicity in pTr2 and PIEC (p < 0.01) and inhibited the proliferation and migration of PIEC (p < 0.01), whereas C20:5 treatment exhibited very low cytotoxicity and minimal inhibition of cellular proliferation. Meanwhile, a low concentration of C16:0 had no effect on the tube formation in PIEC, whereas C20:5 significantly promoted tube formation of PIEC (p < 0.01). These results suggested that saturated fatty acids and n-3 PUFAs had different effects on placental angiogenesis. As essential functional fatty acid, n-3 PUFA might be effective measure in alleviating the placental lipotoxicity caused by sow obesity during pregnancy.

Pro-angiogenic effects of pregnancy-specific glycoproteins in endothelial and extravillous trophoblast cells

We previously reported that binding to heparan sulfate (HS) is required for the ability of the placentally secreted pregnancy-specific glycoprotein 1 (PSG1) to induce endothelial tubulogenesis. PSG1 is composed of four immunoglobulin-like domains but which domains of the protein bind to HS remains unknown. To analyze the interaction of PSG1 with HS, we generated several recombinant proteins, including the individual domains, chimeric proteins between two PSG1 domains, and mutants. Using flow cytometric and surface plasmon resonance studies, we determined that the B2 domain of PSG1 binds to HS and that the positively charged amino acids encompassed between amino acids 43-59 are required for this interaction. Furthermore, we showed that the B2 domain of PSG1 is required for the increase in the formation of tubes by endothelial cells (EC) including a human endometrial EC line and two extravillous trophoblast (EVT) cell lines and for the pro-angiogenic activity of PSG1 observed in an aortic ring assay. PSG1 enhanced the migration of ECs while it increased the expression of matrix metalloproteinase-2 in EVTs, indicating that the pro-angiogenic effect of PSG1 on these two cell types may be mediated by different mechanisms. Despite differences in amino acid sequence, we observed that all human PSGs bound to HS proteoglycans and confirmed that at least two other members of the family, PSG6 and PSG9, induce tube formation. These findings contribute to a better understanding of the pro-angiogenic activity of human PSGs and strongly suggest conservation of this function among all PSG family members.

Placental Angiogenesis in Mammals: A Review of the Regulatory Effects of Signaling Pathways and Functional Nutrients

Normal placental development and proper angiogenesis are essential for fetal growth during pregnancy. Angiogenesis involves the regulatory action of many angiogenic factors and a series of signal transduction processes inside and outside the cell. The obstruction of placental angiogenesis causes fetal growth restriction and serious pregnancy complications, even leading to fetal loss and pregnancy cessation. In this review, the effects of placental angiogenesis on fetal development are described, and several signaling pathways related to placental angiogenesis and their key regulatory mediators are summarized. These factors, which include vascular endothelial growth factor (VEGF)-VEGF receptor, delta-like ligand 4 (DLL-4)-Notch, Wnt, and Hedgehog, may affect the placental angiogenesis process. Moreover, the degree of vascularization depends on cell proliferation, migration, and differentiation, which is affected by the synthesis and secretion of metabolites or intermediates and mutual coordination or inhibition in these pathways. Furthermore, we discuss recent advances regarding the role of functional nutrients (including amino acids and fatty acids) in regulating placental angiogenesis. Understanding the specific mechanism of placental angiogenesis and its influence on fetal development may facilitate the establishment of new therapeutic strategies for the treatment of preterm birth, pre-eclampsia, or intrauterine growth restriction, and provide a theoretical basis for formulating nutritional regulation strategies during pregnancy.

Maternal Supply of Both Arachidonic and Docosahexaenoic Acids Is Required for Optimal Neurodevelopment

During the last trimester of gestation and for the first 18 months after birth, both docosahexaenoic acid,22:6n-3 (DHA) and arachidonic acid,20:4n-6 (ARA) are preferentially deposited within the cerebral cortex at a rapid rate. Although the structural and functional roles of DHA in brain development are well investigated, similar roles of ARA are not well documented. The mode of action of these two fatty acids and their derivatives at different structural-functional roles and their levels in the gene expression and signaling pathways of the brain have been continuously emanating. In addition to DHA, the importance of ARA has been much discussed in recent years for fetal and postnatal brain development and the maternal supply of ARA and DHA. These fatty acids are also involved in various brain developmental processes; however, their mechanistic cross talks are not clearly known yet. This review describes the importance of ARA, in addition to DHA, in supporting the optimal brain development and growth and functional roles in the brain.

Maternal n-3 PUFA deficiency alters uterine artery remodeling and placental epigenome in the mice

The maternal n-3 polyunsaturated fatty acid (PUFA) deficiency on decidual vascular structure and angiogenesis in mice placenta was investigated. Namely, we studied uterine artery remodeling, fatty acid metabolism, and placental epigenetic methylation in this animal model. Weanling female Swiss albino mice were fed either alpha-linolenic acid (18:3 n-3, ALA) deficient diets (0.13% energy from ALA) or a sufficient diet (2.26% energy from ALA) throughout the study. The dietary n-3 PUFA deficiency altered uteroplacental morphology and vasculature by reversing luminal to vessel area and increased luminal wall thickness at 8.5-12.5gD. Further, placentas (F0 and F1) showed a significant decrease in the expression of VCAM1, HLAG proteins and an increase in MMP9, KDR expression. The conversion of ALA to long-chain (LC) n-3 PUFAs was significantly decreased in plasma and placenta during the n-3 deficiency state. Reduced n-3 LCPUFAs increased the placental expression of intracellular proteins FABP3, FABP4, and ADRP to compensate decreased availability of these fatty acids in the n-3 deficient mice. The N-3 PUFA deficiency significantly increased the 5-methylcytosine levels in the placenta but not in the liver. The alteration in DNA methylation continued to the next generation in the placental epigenome with augmented expression of DNMT3A and DNMT3B. Our study showed that maternal n-3 PUFA deficiency alters placental vascular architecture and induces epigenetic changes suggesting the importance of n-3 PUFA intake during the development of the fetus. Moreover, the study shows that the placenta is the susceptible target for epigenetic alteration in maternal deficiency n-3 fatty acids.

Twin-twin transfusion syndrome is associated with alterations in the metabolic profile of maternal plasma in early gestation: a pilot study

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) causes perinatal mortality and morbidity in monochorionic twins. The early recognition of and interventional therapy for TTTS is associated with a more favorable overall prognosis. However, the prediction by the use of ultrasound in the first trimester has relatively poor sensitivity and specificity. This study aimed to identify metabolic biomarkers to aid in ultrasound screening of TTTS.

METHODS

Maternal plasma was prospectively collected between 11 and 15 weeks of gestation in apparently uncomplicated monochorionic-diamniotic twin pregnancies. This cohort was divided into: (i) patients who were subsequently diagnosed with TTTS by using ultrasound; (ii) uncomplicated matched controls. Metabolome was profiled by using gas chromatography-mass spectrometry.

RESULTS

The levels of fatty acids, organic acids, oxaloacetic acid, and beta-alanine were significantly lower in the TTTS maternal plasma at 11-15 weeks of gestation, and methionine and glycine were also higher (p < 0.05, FDR<0.12). Generally, in TTTS pregnancies, the metabolisms of amino acid, carbohydrate, cofactors, vitamins, and purine were "down-regulated"; whereas bile secretion and pyrimidine metabolism were "upregulated."

CONCLUSIONS

The metabolomics scanning of early gestation maternal plasma may identify those pregnancies that subsequently develop TTTS; in particular, downregulated fatty acid levels may be biologically plausible to be implicated in the pathogenesis of TTTS.

Revisiting preeclampsia: a metabolic disorder of the placenta

Preeclampsia (PE) is a leading cause of maternal and neonatal mortality and morbidity worldwide, impacting the long-term health of both mother and offspring. PE has long been characterized by deficient trophoblast invasion into the uterus and consequent placental hypoperfusion, yet the upstream causative factors and effective interventional targets for PE remain unknown. Alterations in the metabolism of preeclamptic placentas are thought to result from placental ischemia, while disturbances of the metabolism and of metabolites in PE pathogenesis are largely ignored. In fact, as one of the largest fetal organs at birth, the placenta consumes a considerable amount of glucose and fatty acid. Increasing evidence suggests glucose and fatty acid exist as energy substrates and regulate placental development through bioactive derivates. Moreover, recent findings have revealed that the placental metabolism adapts readily to environmental changes, altering its response to nutrients and endocrine signals; this adaptability optimizes pregnancy outcomes by diversifying available carbon sources for energy production, hormone synthesis, angiogenesis, immune activation, and tolerance, and fetoplacental growth. These observations raise the possibility that carbohydrate and lipid metabolism abnormalities play a role in both the etiology and clinical progression of PE, sparking a renewed interest in the interrelationship between PE and metabolic dysregulation. This review will focus on key metabolic substrates and regulatory molecules in the placenta and aim to provide novel insights with respect to the metabolism's role in modulating placental development and functions. Further investigations from this perspective are poised to decipher the etiology of PE and suggest potential therapies.

Exploring the role of LC-PUFA metabolism in pregnancy complications

Maternal nutrition during pregnancy plays a significant role in growth and development of the placenta and influencing pregnancy outcome. Suboptimal nutritional status during early gestational period compromises the normal course of pregnancy leading to adverse maternal and fetal outcomes. Omega-3 and omega-6 long chain polyunsaturated fatty acids (LC-PUFA) are important for the growth and development of the placenta. Maternal fatty acids and their metabolites influence the normal course of pregnancy by regulating cell growth and development, cell signaling, regulate angiogenesis, modulate inflammatory responses and influence various structural and functional processes. Alterations in LC-PUFA and their metabolites may result in inadequate spiral artery remodeling or placental angiogenesis leading to structural and functional deficiency of the placenta which contributes to several pregnancy complications like preeclampsia, gestational diabetes mellitus, intrauterine growth restriction, and results in adverse birth outcomes. In this review, we summarize studies examining the role of fatty acids and their metabolites in pregnancy. We also discuss the possible molecular mechanisms through which LC-PUFA influences placental growth and development. Studies have demonstrated that omega-3 fatty acid supplementation lowers the incidence of preterm births, but its effect on reducing pregnancy complications are inconclusive.

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

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

Maternal dietary deficiency of n-3 fatty acids affects metabolic and epigenetic phenotypes of the developing fetus

Polyunsaturated fatty acids (PUFAs) play multiple physiological roles. They regulate the structure and function of cell membranes and cell growth and proliferation, and apoptosis. In addition, PUFAs are involved in cellular signaling, gene expression and serve as precursors to second messengers such as eicosanoids, docosanoids etc. and regulate several physiological processes including placentation, inflammation, immunity, angiogenesis, platelet function, synaptic plasticity, neurogenesis, bone formation, energy homeostasis, pain sensitivity, stress, and cognitive functions. Linoleic acid, 18:2n-6 (LA) and alpha-linolenic acid, 18:3n-3 (ALA) are the two essential fatty acids obtained from the diets and subsequently their long-chain polyunsaturated fatty acids (LCPUFAs) are accumulated in the body. The maternal plasma LCPUFAs especially accumulated in larger amounts in the brain during the third trimester of pregnancy via the placenta and postnatally from mother's breast milk. Various studies, including ours, suggest PUFA's important role in placentation, as well as in growth and development of the offspring. However, intakes of maternal n-3 PUFAs during pregnancy and lactation are much lower in India compared with the Western population. In India, n-3 fatty acid status is further reduced by higher intake of n-6 PUFA rich oils and trans fats. More data on the impacts of long term maternal n-3 PUFA deficiency on placental structure and function, gene expression, epigenetic changes and resultant cognitive function of fetus & infants are emerging. This review summarizes the impacts of n-3 PUFA deficiency in utero on fetal growth and development, adiposity, energy metabolism, musculoskeletal development, and epigenetic changes in feto-placental axis from the recently available pre-clinical and clinical data.

Plastics derived endocrine-disrupting compounds and their effects on early development

Despite the fact that the estrogenic effects of bisphenols were first described 80 years ago, recent data about its potential negative impact on birth outcome parameters raises a strong rationale to investigate further. The adverse health effects of plastics recommend to measure the impacts of endocrine-disrupting compounds (EDCs) such as bisphenols (BPA, BPS, BPF), bis(2-ethylhexyl) phthalate, and dibutyl phthalate (DBP) in human health. Exposure to these compounds in utero may program the diseases of the testis, prostate, kidney and abnormalities in the immune system, and cause tumors, uterine hemorrhage during pregnancy and polycystic ovary. These compounds also control the processes of epigenetic transgenerational inheritance of adult-onset diseases by modulating DNA methylation and epimutations in reproductive cells. The early developmental stage is the most susceptible window for developmental and genomic programming. The critical stages of the events for a normal human birth lie between the many transitions occurring between spermatogenesis, egg fertilization and the fully formed fetus. As the cells begin to grow and differentiate, there are critical balances of hormones, and protein synthesis. Data are emerging on how these plastic-derived compounds affect embryogenesis, placentation and feto-placental development since pregnant women and unborn fetuses are often exposed to these factors during preconception and throughout gestation. Impaired early development that ultimately influences fetal outcomes is at the center of many developmental disorders and contributes an independent risk factor for adult chronic diseases. This review will summarize the current status on the impact of exposure to plastic derived EDCs on the growth, gene expression, epigenetic and angiogenic activities of the early fetal development process and their possible effects on birth outcomes.

Maternal dietary fatty acids and their roles in human placental development

Fatty acids are essential for feto-placental growth and development. Maternal fatty acids and their metabolites are involved in every stage of pregnancy by supporting cell growth and development, cell signaling, and modulating other critical aspects of structural and functional processes. Early placentation process is critical for placental growth and function. Several fatty acids modulate angiogenesis as observed by increased tube formation and secretion of angiogenic growth factors in first-trimester human placental trophoblasts. Long-chain fatty acids stimulate angiogenesis in these cells via vascular endothelium growth factor (VEGF), angiopoietin-like protein 4 (ANGPTL4), fatty acid-binding proteins (FABPs), or eicosanoids. Inadequate placental angiogenesis and trophoblast invasion of the maternal decidua and uterine spiral arterioles leads to structural and functional deficiency of placenta, which contributes to preeclampsia, pre-term intrauterine growth restriction, and spontaneous abortion and also affects overall fetal growth and development. During the third trimester of pregnancy, placental preferential transport of maternal plasma long-chain polyunsaturated fatty acids is of critical importance for fetal growth and development. Fatty acids cross the placental microvillous and basal membranes by mainly via plasma membrane fatty acid transport system (FAT, FATP, p-FABPpm, & FFARs) and cytoplasmic FABPs. Besides, a member of the major facilitator superfamily-MFSD2a, present in the placenta is involved in the supply of DHA to the fetus. Maternal factors such as diet, obesity, endocrine, inflammation can modulate the expression and activity of the placental fatty acid transport activity and thereby impact feto-placental growth and development. In this review, we discuss the maternal dietary fatty acids, and placental transport and metabolism, and their roles in placental growth and development.

Upregulated LncZBTB39 in pre-eclampsia and its effects on trophoblast invasion and migration via antagonizing the inhibition of miR-210 on THSD7A expression

OBJECTIVE

Pre-eclampsia (PE) is a major cause of maternal morbidity and mortality, but its etiology remains to be elucidated. Accumulating evidence suggests that placental long noncoding RNAs (lncRNAs) might contribute to the pathogenesis of pre-eclampsia.

STUDY DESIGN

In the present study, the expression levels of lncRNAs in human placenta were first determined by microarray analysis and then validated by secondary RT-qPCR and FISH. LncZBTB39 expression manipulation in HTR8/SVneo trophoblast cells was achieved by shRNA and plasmid transfection. Then, the invasion and migration of lncZBTB39-deficient and lncZBTB39-overexpressing trophoblast cells were evaluated by transwell assays and wound-healing assays, respectively. MMP2 activity was measured by gelatin zymography. The downstream target genes of lncZBTB39 were then identified by a transcriptomic microarray, followed by RT-qPCR validation.

RESULTS

We found that lncZBTB39 was upregulated in PE-complicated human placentas, and overexpression of lncZBTB39 inhibited invasion and migration, as well as MMP2 activity in HTR8/SVneo cells, while downregulation of lncZBTB39 enhanced invasion, migration and MMP2 activity. In addition, THSD7A expression was elevated by lncZBTB39 overexpression but reduced in lncZBTB39-deficient cells; moreover, lncZBTB39 antagonized the inhibitory effects of miR-210 on THSD7A expression.

CONCLUSION

PE-complicated placentas are associated with upregulated lncZBTB39, which negatively regulates trophoblast invasion and migration, most likely by preserving the expression of THSD7A mRNA through sponging miR-210. The results of this study not only provide novel evidence that lncRNAs regulate trophoblastic activities but also suggest that lncZBTB39 may be a potential interventional target for PE.

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.

LncRNA TDRG1/miR-214-5p axis affects preeclampsia by modulating trophoblast cells

Because of limited treatment options, preeclampsia (PE) is the leading cause of perinatal morbidity and mortality worldwide. Recently, lncRNA TDRG1 is reported to be aberrantly down-regulated in PE placenta, and the abnormal expression of TDRG1 might play a key or partial role in PE development. In this study, we found that TDRG1 was significantly down-regulated in PE placenta compared with the normal placenta. The cell proliferation, migration, invasion, and cell cycle were explored by CCK-8, wound-healing, transwell, and flow cytometer assay, respectively. Experimental results showed that TDRG1 accelerated the proliferation, migration, and invasion of trophoblast cells. Dual-luciferase reporter assays confirmed that TDRG1 could bind to miR-214-5p. Besides, knockdown of TDRG1 suppressed the cell proliferation, migration, and invasion, while knockdown of miR-214-5p reversed the effect. Jagged1 and Notch1 were negatively regulated by miR-214-5p while positively modulated by TDRG1. In conclusion, TDRG1 promoted trophoblast cells viability and invasion by negatively regulating miR-214-5p expression, contributing to a better understanding of PE pathogenesis and providing new light on TDRG1-directed diagnosis and treatment. SIGNIFICANCE OF THE STUDY: In this work, we observed that TDRG1 was able to promote cell proliferation, migration, and invasion cells by suppressing the expression of miR-214-5p and regulating the Notch signalling pathway in trophoblast cells. As far as we know, the effect of TDRG1/miR-214-5p axis on cell viability, migration, and invasion of trophoblast cells was firstly introduced. Our findings provided a better understanding of the mechanism of PE. Moreover, it is reasonable to believe that TDRG1 may be employed as a strategy to treat PE in the future.

Metabolism of 13C-Labeled Fatty Acids in Term Human Placental Explants by Liquid Chromatography-Mass Spectrometry

Placental lipid transport and metabolism are poorly understood despite the importance for fetal development and lifelong health. We aimed to explore fatty acid (FA) processing in human villous placental explants from seven uncomplicated term singleton pregnancies delivered by elective cesarean section. Explants were treated with stable isotope-labeled palmitic acid (13C-PA), oleic acid (13C-OA), or docosahexaenoic acid (13C-DHA) for 3, 24, or 48 hours. Stable isotope-labeled lipids synthesized by placental explants from labeled FA were quantified, alongside endogenous unlabeled placental lipids, by liquid chromatography-mass spectrometry. Labeled phosphatidylcholines (PCs), triacylglycerols (TAGs), and phosphatidylethanolamines were detected in explants, whereas labeled lysophosphatidylcholines were found in both explants and conditioned media. 13C-PA was primarily directed into PC synthesis (74% of 13C-PA-labeled lipids), whereas 13C-OA was directed almost equally into PC and TAG synthesis (45% and 53%, respectively, of 13C-OA-labeled lipids). 13C-DHA was only detectable in TAGs. TAGs demonstrated the highest isotopic enrichment for all 13C-FAs with 13C-OA-TAGs comprising >50% of total OA-TAGs (unlabeled and labeled), consistent with TAGs being a labile and accessible reservoir for FA storage. Variations in lipid incorporation were correlated to maternal glycemia and body mass index, suggesting that this experimental model could be used to investigate the effect of maternal factors on placental lipid metabolism. We conclude that lipid metabolic partitioning of freshly imported FAs into labile and less labile lipid reservoirs in placenta is FA dependent. This process may partly mediate the physiological preferential transplacental transfer of particular FAs to the fetus, but may also be implicated in the fetoplacental pathophysiology of maternal metabolic dysfunction.

New insight into the role of long non-coding RNAs in the pathogenesis of preeclampsia

OBJECTIVE

Dysregulation of lncRNAs and the absence of coordination between them could affect the normal placentation, uteroplacental circulation, and endothelial cell function. All these misfunctions can finally lead to preeclampsia.

METHODS

 In the present review, we discuss current literature (till May 2018) about lncRNAs expression and function in the placenta, trophoblast cells, and decidua.

RESULTS AND CONCLUSION

It is explained how altered expression of the lncRNAs and abnormal regulation of them affect the risk of preeclampsia. However, the interaction between various lncRNAs and coordinate regulation of them in health and failure of such coordinative mechanisms in diseases such as preeclampsia need to be elucidated.

Serum fatty acids are positively associated with changes in systemic blood pressure throughout pregnancy

OBJECTIVES

To assess whether serum concentrations of saturated (SFAs), polyunsaturated (PUFAs), and monounsaturated (MUFAs) fatty acids are associated with changes in blood pressure (BP) throughout pregnancy.

STUDY DESIGN

Prospective cohort.

MAIN OUTCOME MEASURES

Longitudinal measurements of systolic (SBP) and diastolic (DBP) BP.

METHODS

Two hundred twenty-three healthy pregnant women were recruited in a public health center in Rio de Janeiro, Brazil between 2009 and 2011. Fasting blood samples and BP measurements were obtained at the 1st (5th-13th weeks), 2nd (20^th-26th) and 3rd trimester (30th-36th). Crude and adjusted (maternal age, education, energy intake, gestational body weight change, leptin concentrations, early pre-pregnancy BMI, leisure time physical activity prior to pregnancy and linear and quadratic gestational weeks) longitudinal linear mixed-effects models were employed.

RESULTS

SBP and DBP decreased from the 1st to the 2nd trimester and slightly increased from the 2nd to the 3rd trimester (P < 0.001). In the adjusted model (ß and 95% CI), total SFAs [0.005 (0.001-0.008); P = 0.008], total MUFAs [0.005 (0.001-0.009); P = 0.019] and total n-6 PUFAs [0.005 (0.001-0.009); P = 0.025] were positively associated with SBP throughout pregnancy.

CONCLUSIONS

Maternal serum concentrations of total SFAs, MUFAs and n-6 PUFAs were positively associated with BP levels in normotensive pregnant women.

Long Non-Coding RNA Uc.187 Is Upregulated in Preeclampsia and Modulates Proliferation, Apoptosis, and Invasion of HTR-8/SVneo Trophoblast Cells

Among the preeclampsia-related long non-cording RNAs (lncRNAs) screened with a gene chip in our preliminary study, uc.187 attracted our attention because of its high conservation across different species and significant positive correlation with preeclampsia (PE). The literature and bioinformatics analysis suggested that lncRNA uc.187 might be associated with cell growth, invasion, and apoptosis. The expression of uc.187 in severe preeclamptic placentas (n = 31) and normal placentas (n = 18) was evaluated by real-time reverse transcription polymerase chain reaction (qRT-PCR). We constructed a silencing lentivirus vector (uc.187 siRNA) to explore the biological function of uc.187 in the development and progression of HTR-8/SVneo trophoblast cells in vitro. Furthermore, we utilized CCK8 analysis, a transwell invasion assay, and flow cytometry to determine the role of uc.187 in the proliferation, invasion, and apoptosis of HTR-8/SVneo trophoblast cells. The proteins related to proliferation (PCNA, Ki67), invasion (MMP-2/-9 and TIMP-1), and apoptosis (caspase-3, Bcl-2) were evaluated with a Western blot assay. The results showed that there was an obvious upregulation of uc.187 expression in preeclamptic placental tissues. In addition, uc.187 silencing enhanced cell proliferation and invasion and reduced the cellular apoptotic response. Taken together, our findings suggest for the first time that abnormal expression of lncRNA uc.187 may lead to the aberrant biological behavior of HTR-8/SVneo cells. Therefore, we propose uc.187 as a novel lncRNA molecule that might contribute to the development of PE and might represent a potential diagnostic and therapeutic target for this disease. J. Cell. Biochem. 118: 1462-1470, 2017. © 2016 Wiley Periodicals, Inc.

Decorin-Mediated Inhibition of Human Trophoblast Cells Proliferation, Migration, and Invasion and Promotion of Apoptosis In Vitro

Preeclampsia (PE) is a unique complication of pregnancy, the pathogenesis of which has been generally accepted to be associated with the dysfunctions of extravillous trophoblast (EVT) including proliferation, apoptosis, and migration and invasion. Decorin (DCN) has been proved to be a decidua-derived TGF-binding proteoglycan, which negatively regulates proliferation, migration, and invasiveness of human extravillous trophoblast cells. In this study, we identified a higher expression level of decorin in severe PE placentas by both real-time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). And an inhibitory effect of decorin on proliferation, migration, and invasion and an enhanced effect on apoptosis in trophoblast cells HTR-8/SVneo and JEG-3 were validated in vitro. Also the modulations of decorin on trophoblast cells' metastasis and invasion functions were detected through regulating the matrix metalloproteinases (MMP2 and MMP9). Thus, we suggested that the contribution of decorin to the modulation of trophoblast cells might have implications for the pathogenesis of preeclampsia.

Maternal fish consumption, fatty acid levels and angiogenic factors: The Generation R Study

INTRODUCTION

Angiogenic factors, such as placental growth factor (PlGF) and soluble Flt-1 (sFlt-1), are key regulators of placental vascular development. Evidence from in vitro studies indicates that fatty acids can affect angiogenesis. We investigated the associations of maternal fish consumption and fatty acids levels with angiogenic factors during pregnancy, and in cord blood in a large population-based prospective cohort.

METHODS

First trimester fish consumption was assessed among 3134 pregnant women using a food-frequency questionnaire. Plasma fatty acid levels were measured in second trimester. Plasma PlGF and sFlt-1 were measured in first and second trimester and in cord blood. Associations of fish consumption or fatty acid levels with angiogenic factors were assessed by multivariable linear regression analyses.

RESULTS

There were no consistent associations of total fish or lean fish consumption with levels of PlGF, sFlt-1, or sFlt-1/PlGF ratio. Neither fatty fish nor shellfish were associated with angiogenic factors. Plasma omega-3 polyunsaturated fatty acids, which are the main type of fatty acids in fish, were inconsistently associated with angiogenic factors in second trimester and cord blood. Yet, higher levels of arachidonic acid, an omega-6 polyunsaturated fatty acid, were associated with lower levels of PlGF and sFlt-1.

DISCUSSION

We found no consistent associations of fish consumption or fatty acids levels with angiogenic factors in a population with low fish consumption. Studies including populations with higher fish consumption are required to fully grasp the potential effects of maternal fish consumption on placental angiogenesis.

Docosahexaenoic acid supplementation early in pregnancy may prevent deep placentation disorders

Uteroplacental ischemia may cause preterm birth, either due to preterm labor, preterm premature rupture of membranes, or medical indication (in the presence of preeclampsia or fetal growth restriction). Uteroplacental ischemia is the product of defective deep placentation, a failure of invasion, and transformation of the spiral arteries by the trophoblast. The failure of normal placentation generates a series of clinical abnormalities nowadays called "deep placentation disorders"; they include preeclampsia, fetal growth restriction, preterm labor, preterm premature rupture of membranes, in utero fetal death, and placental abruption. Early reports suggested that a LC-PUFAs (long chain polyunsaturated fatty acids) rich diet reduces the incidence of deep placentation disorders. Recent randomized controlled trials are inconsistent to show the benefit of docosahexaenoic acid (DHA) supplementation during pregnancy to prevent deep placentation disorders, but most of them showed that DHA supplementation was associated with lower risk of early preterm birth. We postulate that DHA supplementation, early in pregnancy, may reduce the incidence of deep placentation disorders. If our hypothesis is correct, DHA supplementation, early in pregnancy, will become a safe and effective strategy for primary prevention of highly relevant pregnancy diseases, such as preterm birth, preeclampsia, and fetal growth restriction.

Maternal dietary omega-3 fatty acids and placental function

The developing fetus requires substantial amounts of fatty acids to support rapid cellular growth and activity. Although the fatty acid composition delivered to the fetus is largely determined by maternal circulating levels, the placenta preferentially transfers physiologically important long-chain polyunsaturated fatty acids (LC-PUFAs), particularly omega-3 (n-3) PUFAs. Maternal dietary supplementation with n-3 PUFAs during pregnancy has been shown to increase gestation length, enhance fetal growth, and reduce the risk of pregnancy complications, although the precise mechanisms governing these effects remain uncertain. Omega-3 PUFAs are involved in several physiological pathways which could account for these effects, including anti-inflammatory, pro-resolving, and anti-oxidative pathways. Recent studies have shown that maternal dietary n-3 PUFA supplementation during rat pregnancy can reduce placental oxidative damage and increase placental levels of pro-resolving mediators, effects associated with enhanced fetal and placental growth. Because several placental disorders, such as intrauterine growth restriction, preeclampsia, and gestational diabetes mellitus, are associated with heightened placental inflammation and oxidative stress, there is considerable interest in the potential for dietary n-3 PUFAs as a therapeutic intervention for these disorders. In this study, we review the impact of dietary n-3 PUFAs on placental function, with particular focus on placental inflammation, inflammatory resolution, and oxidative stress.

Upregulation of long noncoding RNA SPRY4-IT1 modulates proliferation, migration, apoptosis, and network formation in trophoblast cells HTR-8SV/neo

SPRY4-IT1 has been reported to have extremely high expression in normal placenta tissues. It is a Long noncoding RNA (lncRNA), which is associated with cell growth, migration, invasion, and apoptosis in melanoma. A 2.8-fold increase of SPRY4-IT1 expression was validated by Real-time reverse transcription-polymerase chain reaction (qRT-PCR) in severe preeclamptic placenta as compared with that of the normal ones (n=25) in this study. Furthermore, the role of SPRY4-IT1 in proliferation, migration, apoptosis, and network formation ability of trophoblast cells HTR-8/SVneo was assessed. Suppression of SPRY4-IT1 using siRNA treatment and its overexpression using plasmid targeting SPRY4-IT1 were performed in order to explore the biological function of SPRY4-IT1 in the development and progression of trophoblast cells HTR-8/SVneo, in vitro. The results showed that SPRY4-IT1 knockdown enhanced the cell migration and proliferation, and reduced the response of cells to apoptosis. However, exogenous SPRY4-IT1 overexpression significantly decreased the cell migration and proliferation, while increased cell apoptosis. Our study showed for the first time that aberrant expression of lncRNA SPRY4-IT1 might contribute to the abnormal condition of trophoblast cells HTR-8/SVneo. Therefore, we proposed SPRY4-IT1 as a novel lncRNA molecule, which might be associated with the pathogenesis of preeclampsia and might provide a new target for its early diagnosis and treatment.