Hypoxia Inducible Factors (HIF1α and HIF3α) are differentially methylated in preeclampsia placentae and are associated with birth outcomes.

Preeclampsia is a placental vascular pathology and hypoxia is known to influence placental angiogenesis. Hypoxia Inducible Factors (HIF1α and HIF3α) mediate the response to cellular oxygen concentration and bind to hypoxia response element of target genes. However the mechanism regulating above activity is not well-understood. We investigated if placental DNA methylation (DNAm) and expression of HIF1α and 3α genes are altered and associated with pre-eclampsia, placental weight and birth outcomes. Using a cohort comprising women with preeclampsia [N = 100, delivering at term (N = 43) and preterm (N = 57)] and normotensive controls (N = 100), we analysed DNAm in HIF1α and 3α, and their mRNA expression in placentae, employing pyrosequencing and quantitative real-time PCR, respectively. We observed significant hypermethylation at cg22891070 of HIF3α in preeclampsia placentae compared to controls (ß = 1.5%, p = 0.04). CpG8 in the promoter region of HIF1α, showed marginally significant hypomethylation in preterm preeclampsia compared to controls (ß = - 0.15%, p = 0.055). HIF1α expression was significantly lower in preterm preeclampsia compared to controls (mean ± SE = 10.16 ± 2.00 vs 4.25 ± 0.90, p = 0.04). Further, DNAm in HIF1α promoter region was negatively associated with its expression levels (ß = - 0.165, p = 0.024). Several CpGs in HIF1α were negatively associated with placental weight and birth outcomes including birth weight (ß range = - 0.224-0.300) and birth length [ß range = - 0.248 to - 0.301 (p < 0.05 for all)]. Overall, we demonstrate altered DNAm in HIF1α and HIF3α in preeclampsia placentae, also associated with various birth outcomes. Correlation of DNAm in HIF1α and its expression suggests a possible role in the pathogenesis of pre-eclampsia. Further investigations on interactions between HIF1α and HIF3α in preeclampsia would be interesting.

Differential Expression of Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF) in Different Regions of Normal and Preeclampsia Placentae.

Background: Our recent study indicates differential protein levels of neurotrophins and angiogenic factors in various regions of the normotensive and preeclampsia (PE) placenta. These changes may be in a response to differential mRNA expression of neurotrophins.Methods: This study examines the mRNA levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in different regions of the placenta in normotensive control (NC) women and women with PE. Thirty NC women and forty one women with PE (18 delivered at term [T-PE] and 23 delivered preterm [PT-PE]) were included in the study. Placental samples were taken from four regions: central basal (CM), central chorionic (CF), peripheral basal (PM), and peripheral chorionic (PF). The mRNA levels of neurotrophins were measured by quantitative real-time PCR.Results: The BDNF mRNA levels were higher in peripheral fetal region as compared to peripheral basal region in NC (p < 0.05) group, PE group (p < 0.05) and term PE group (p < 0.01). The BDNF mRNA levels were lower in the central basal region of preterm PE group (p < 0.05) as compared to the NC group.Conclusion: The present study indicates that NGF and BDNF are expressed differentially across various regions of the placenta. This has implications for selection of the sampling site in the placenta while carrying out placental studies.

Maternal omega-3 fatty acids and vitamin E improve placental angiogenesis in late-onset but not early-onset preeclampsia.

Abnormal placental vasculature is associated with preeclampsia. Preeclampsia is of two types, i.e., early- and late-onset preeclampsia (LOP), both having different etiologies. We have earlier demonstrated low levels of omega-3 fatty acids and vitamin E in women with preeclampsia. The current study examines the effect of maternal omega-3 fatty acids and vitamin E supplementation on angiogenic factors in a rat model of preeclampsia. Pregnant rats were divided into a total of five groups control, early-onset preeclampsia (EOP); LOP; EOP supplemented with omega-3 fatty acid and vitamin E and LOP supplemented with omega-3 fatty acid and vitamin E. Preeclampsia was induced by administering L-nitroarginine methylester (L-NAME) at the dose of 50 mg/kg body weight/day. The vascular endothelial growth factor gene expression and protein levels were lower (p < 0.01 for both) in animals from both EOP as well as LOP groups (p < 0.01). In the EOP group, the protein levels of VEGF receptor-1 were also lower (p < 0.01). Supplementation of omega-3 fatty acids and vitamin E to LOP improved the levels of VEGF and VEGF receptor-1 only in the LOP but not in the EOP group. In the EOP group, the gene expression of hypoxia inducible factor 1 alpha (HIF-1α) in the placenta was higher (p < 0.05) and supplementation normalized these levels. Our findings indicate that maternal supplementation of omega-3 fatty acids and vitamin E has differential effect on preeclampsia subtypes.

The REVAMP study: research exploring various aspects and mechanisms in preeclampsia: study protocol.

BACKGROUND: Preeclampsia is a major cause of maternal, fetal and neonatal morbidity and mortality, particularly in developing countries. Considering the burden of preeclampsia and its associated complications, it is important to understand the underlying risk factors and mechanisms involved in its etiology. There is considerable interest in the potential for dietary long chain polyunsaturated fatty acids (LCPUFA) as a therapeutic intervention to prevent preeclampsia, as they are involved in angiogenesis, oxidative stress, and inflammatory pathways. METHODS: The REVAMP study (Research Exploring Various Aspects and Mechanisms in Preeclampsia) follows a cohort of pregnant women from early pregnancy until delivery to examine longitudinally the associations of maternal LCPUFA with clinical outcome in preeclampsia. A multisite centre for advanced research was established and pregnant women coming to Bharati hospital and Gupte hospital, Pune, India for their first antenatal visit are recruited and followed up at 11-14 weeks, 18-22 weeks, 26-28 weeks, and at delivery. Their personal, obstetric, clinical, and family history are recorded. Anthropometric measures (height, weight), food frequency questionnaire (FFQ), physical activity, socioeconomic status, fetal ultrasonography, and color Doppler measures are recorded at different time points across gestation. Maternal blood at all time points, cord blood, and placenta at delivery are collected, processed and stored at - 80 °C. The children's anthropometry is assessed serially up to the age of 2 years, when their neurodevelopmental scores will be assessed. DISCUSSION: This study will help in early identification of pregnant women who are at risk of developing preeclampsia. The prospective design of the study for the first time will establish the role of LCPUFA in understanding the underlying biochemical and molecular mechanisms involved in preeclampsia and their association with developmental programming in children.

Matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases -9 (MMP-9) are differentially expressed in different regions of normal and preeclampsia placentae.

Matrix metalloproteinases (MMPs) are involved in the extracellular matrix (ECM) remodeling during human placentation and parturition and have been shown to be associated with oxidative stress. Placental regional changes in oxygen availability and oxidative stress indices may influence regional differences in expression of MMPs. This study examines the protein and mRNA levels of MMP-2 and MMP-9 in different regions of the placenta in normotensive control (NC) women and women with preeclampsia (PE). Fifty-two NC women and 43 women with PE (18 delivered at term [T-PE] and 25 delivered preterm [PT-PE]) were recruited. Placental samples were taken from four regions: central basal (CM), central chorionic (CF), peripheral basal (PM), and peripheral chorionic (PF). MMP protein and mRNA levels were measured by ELISA and quantitative real time PCR, respectively. MMP-2 protein levels were higher in all the placental regions (P < 0.05) from PT-PE group as compared to the respective regions from the NC and T-PE groups. MMP-9 mRNA levels were higher in CM region as compared to CF and PM regions (P < 0.05) in the NC group and compared to CF and PF regions (P < 0.05) in the T-PE group. The MMP-9 mRNA levels were lower in the CF region in the PT-PE and T-PE groups (P < 0.05) as compared to the NC group. Elevated levels of MMP-2 protein levels were observed in all regions of PT-PE placenta possibly influencing the degradation of placental ECM. Lower mRNA expression of MMP-9 both in PT-PE and T-PE may contribute to a disturbed placental vascularization.

VEGF and VEGFR1 levels in different regions of the normal and preeclampsia placentae.

Altered placental angiogenesis is implicated in the pathophysiology of preeclampsia. We have earlier reported placental regional differences in oxidative stress markers and neurotrophins. Oxidative stress and neurotrophins are reported to regulate angiogenesis. This study aims to examine protein and mRNA levels of vascular endothelial growth factor (VEGF) and VEGF receptor 1 (VEGFR1) in four regions [central maternal (CM), central fetal (CF), peripheral maternal (PM), and peripheral fetal (PF)] of the placenta in normotensive control (NC) women (n = 51) and women with preeclampsia (PE) (n = 43) [18 delivered at term (T-PE) and 25 delivered preterm (PT-PE)]. In all groups, CF region reported highest VEGF protein levels compared to all other regions. VEGF mRNA level was higher in CF region as compared to CM region in PE group (p < 0.05). VEGF levels were lower in all regions of PE, T-PE, and PT-PE groups (p < 0.05) as compared to their respective regions in NC group. VEGFR1 levels were lower in CF (p < 0.05) and PF (p < 0.01) regions as compared to CM region only in control. However, VEGFR1 levels were higher in CF (p < 0.05) and PF (p < 0.01) regions of PT-PE group as compared to control. VEGFR1 mRNA level was higher in PM region of PE group and T-PE group (p < 0.05 for both) as compared to control. VEGF levels in the PF region were positively associated with birth weight and placental weight. This study describes placental regional changes in angiogenic factors particularly highlighting increased VEGF in CF region possibly in response to hypoxic conditions prevailing in placenta.

Investigating the expression of MMPs and TIMPs in preterm placenta and role of CpG methylation in regulating MMP-9 expression.

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are crucial to the processes of normal labor and parturition. We have previously reported aberrant protein levels of MMPs in placenta of women delivering preterm as compared to term. In this study, we examine the mRNA levels of MMPs (MMP-1, MMP-2, and MMP-9) and TIMPs (TIMP-1, TIMP-2) in the placenta from women delivering preterm as compared with term and further study the promoter DNA methylation of the MMP-9 gene in a sub-sample of term and preterm placentae. A total of 110 women were included in the study; 56 delivered term and 54 delivered preterm. MMP and TIMP mRNA levels were determined by Taqman-based qPCR. Promoter CpG methylation of MMP-9 gene was studied on a subset of 10 term and 8 preterm placenta using Epitect Methyl-II PCR assay kit. The mRNA levels of MMP-1,-2 were higher and those of TIMP-1,-2 were lower in the placentae of women delivering preterm. MMP-9 levels were comparable between the two groups. Among women undergoing spontaneous vaginal deliveries, higher mRNA levels of MMP-1, -2 and -9 were seen in the placentae of those delivering preterm as compared to term. Similar results were seen in women undergoing preterm labor as compared to term. MMP-9 gene promoter was hypomethylated in preterm placenta as compared to term placenta, while the mRNA levels were comparable between the two groups. The observed imbalance between MMP and TIMP expression may have prematurely triggered the signaling cascade leading to preterm birth. © 2017 IUBMB Life, 69(12):985-993, 2017.

Sex-specific differences and developmental programming for diseases in later life.

Epidemiological data indicate that developmental programming of various non-communicable diseases (NCDs) occurs as a consequence of altered maternal metabolic and physiological status due to a number of environmental insults during pregnancy. Sex-specific differences have also been reported in most NCDs. Evidence suggests that beginning from conception, the maternal and neonatal metabolic environment, including hormones, contributes to sex-specific placental development. The placenta then regulates the sex-specific differences in NCDs via the epigenetic mechanisms that are further affected by hormones. Male and female embryos have been reported to exhibit sex-specific transcriptional regulation, and it is suggested that their development can be considered as separate processes beginning from conception. This review summarises various animal and human studies examining sex-specific differences in NCDs due to differential placental epigenetic developmental programming. An overview of possible mechanisms underlying this is also discussed. Further, the review describes sex-specific changes in the structure and function of the placenta in pregnancies complicated by fetal growth restriction, pre-eclampsia and preterm birth. Thus, because sex-specific differences are associated with fetal outcome and survival, future studies need to take into consideration the sex of the fetus while explaining the concept of the developmental origins of health and disease.

Regional changes of placental vascularization in preeclampsia: a review.

Preeclampsia is characterized by vascular dysfunction and results in maternal and fetal morbidity and mortality. The placenta plays a critical role in the growth and development of the fetus, and recent studies indicate that placental architecture, oxygen availability, and oxidative stress indices vary across different regions of the placenta. Our earlier studies have reported altered maternal angiogenesis and differential placental gene expression and methylation patterns of angiogenic factors in women with preeclampsia when compared with normotensive women. We have also demonstrated lower maternal and placental neurotrophin (NT) levels in women with preeclampsia. Studies suggest that oxidative stress is associated with proteases like matrix metalloproteinases (MMPs) and growth factors like NTs and angiogenic factors known to be involved in the process of angiogenesis. Recently, we have reported regionwise differential oxidative stress, antioxidant enzyme activity, and NT levels in placenta from normotensive control women and women with preeclampsia. The current review describes the regional changes in the placenta and highlights the role of placental oxidative stress in influencing regional differences in the expression of angiogenic factors, MMPs, and NTs. This review discusses the need for further research on various growth factors and proteins involved in the process of placental development across different regions of the placenta. This would help to understand whether regional differences in these factors affect the growth and development of the fetus.

Maternal nutrition influences angiogenesis in the placenta through peroxisome proliferator activated receptors: A novel hypothesis.

Placental angiogenesis is critical to maintain adequate blood flow during gestation, and any alterations in this process can result in an adverse pregnancy. Growing evidence indicates that suboptimal maternal nutrition can alter placental development. Although the underlying mechanisms are not clear, maternal nutrition likely influences the expression of genes involved in placental development through regulation of various transcription factors such as peroxisome proliferator-activated receptors (PPARs), which can be activated by ligands including long-chain polyunsaturated fatty acids. Indeed, several studies demonstrated a role for PPAR in implantation, trophoblast differentiation, and angiogenesis. Alterations in maternal nutrition during pregnancy can affect the expression of PPARs via epigenetic mechanisms or through homocysteine, which is known to compete for PPARs. This review discusses the role of maternal nutrition-particularly micronutrients like folate, vitamin B12 , and omega-3 fatty acids-in modulating the activity of PPARs during placentation and angiogenesis, which affects placental and fetal growth. Additional animal and human studies need to be undertaken to elucidate the molecular mechanisms through which maternal nutrition regulates PPARs, specifically to determine whether PPARs affect placental angiogenesis directly through angiogenic factors or indirectly by modulating trophoblast differentiation.

Maternal angiogenic factor disruptions prior to clinical diagnosis of preeclampsia: insights from the REVAMP study.

Preeclampsia is characterized by impaired angiogenesis and assessment of angiogenic factors can play a crucial role in the early diagnosis of preeclampsia. The current study reports the levels of angiogenic factors longitudinally from early pregnancy in women with preeclampsia and in the subtypes of preeclampsia, to identify their role in early prediction of preeclampsia. A total of 1154 women with singleton pregnancies were recruited in early pregnancy from 2 hospitals. Blood samples were collected, plasma samples were separated and stored at four time points across gestation: V1 = 11-14 weeks, V2 = 18-22 weeks, V3 = 26-28 weeks, and V4 = at delivery. The current study includes a total of 108 women developed preeclampsia (PE), and 216 matched controls. Angiogenic factors were estimated using commercially available ELISA kits. Receiver operating characteristic (ROC) curves were used to evaluate the potential diagnostic value in the prediction of PE. Lower levels of VEGF, PlGF, and higher levels of sEng and sEng/PlGF ratio (p < 0.05 for all) predate clinical diagnosis in women with preeclampsia. sEng levels and sEng/PlGF ratio showed significant correlation with odds of preeclampsia at all the timepoints. This study identifies a cut off of 33.5 for sFlt-1/PlGF and 25.9 for sEng/PlGF for prediction of early onset preeclampsia. This study reports various angiogenic factors serially across gestation in a general population to identify women at risk of developing preeclampsia and its subtypes. The study also reports a potential biomarker and a pragmatic window for estimation of angiogenic markers to identify women at risk.

Fatty acids and their metabolites (resolvins) are altered in women with gestational diabetes mellitus (GDM).

The maternal fatty acid status plays a key role in influencing pregnancy outcomes. Omega-3 fatty acids are the precursors for E-series (RvE) and D-series resolvins (RvD) and possess anti-inflammatory properties. Pregnancy complications like gestational diabetes mellitus (GDM) are associated with excess maternal inflammation. This study reports the levels of maternal fatty acids across gestation in GDM and non-GDM women, placental fatty acids, resolvins and their association with the maternal fatty acid status. Pregnant women were recruited at 11-14 (V1) weeks and followed at 18-22 (V2) and 26-28 (V3) weeks and at delivery (V4). A total of 209 women who were diagnosed as GDM and 207 non-GDM women were included in this study. Fatty acids were estimated using gas chromatography. The protein levels of resolvins (RvE1, RvE2, RvD1 and RvD2) were measured using ELISA kits. Total PUFAs, eicosapentaenoic acid (EPA), omega-6 fatty acids, linoleic acid (LA) and arachidonic acid (AA) were lower, while saturated fatty acid (SFA) and alpha-linolenic acid (ALA) levels were higher in GDM women at 18-22 weeks. Placental AA was lower (p < 0.05) in women with GDM. Placental protein levels of RvE1, RvD1 and RvD2 were lower (p < 0.001 for all) in the GDM group. The maternal delta 5 desaturase index was positively associated, while erythrocyte omega-3 and omega-6 fatty acids were negatively associated with RvE2 at 11-14 weeks. Placental LA and ALA were positively associated with RvD1 and RvD2 (p < 0.05, for both), respectively. Our findings suggest that the maternal fatty acid status influences pro-resolving mediators which may lead to increased inflammation in GDM.

Matrix metalloproteinases-2, -3 and tissue inhibitors of metalloproteinases-1, -2 in placentas from preterm pregnancies and their association with one-carbon metabolites.

Maternal nutrition is an important determinant of one-carbon metabolism and defects in the one-carbon metabolism may lead to poor obstetric outcomes. This study was designed to test the hypothesis that altered intake/metabolism of micronutrients (folic acid and vitamin B12) and docosahexaenoic acid (DHA) contributes to increased homocysteine and oxidative stress leading to altered levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in women delivering preterm. We have earlier reported increased vitamin B12, homocysteine, and oxidative stress along with reduced placental DHA in women delivering preterm. In this study, we further examine the placental levels of MMP2, MMP3, TIMP1, and TIMP2 in 75 women delivering at term and 73 women delivering preterm. Placental levels of MMPs and TIMPs were determined by ELISA. Placental MMP2 and MMP3 levels were higher (P<0.01) in women delivering preterm as compared with term. There was no difference in the placental TIMP1 and TIMP2 levels in women delivering preterm and at term. Further placental MMP2 and MMP3 levels were higher (P<0.01) in women with preterm labor as compared with those in labor at term, suggesting that MMPs may favor degradation of extracellular matrix in the placenta during preterm labor. Our study for the first time suggests a crucial role of micronutrients and MMPs in preterm birth. Future studies need to examine if epigenetic modifications through the one-carbon cycle contribute to increased levels of MMPs leading to preterm deliveries.

Assisted reproductive technology (ART) and epigenetic modifications in the placenta.

Assisted reproductive technology (ART) has become common amongst couples with infertility issues. ART is known to be successful, but epidemiological data indicates that ART is associated with placental disorders. Additionally, reports show increased risks of short- and long-term complications in children born to mothers undergoing ART. However, the mechanisms responsible for these events are obscure. The placenta is considered as a key organ for programming of diseases and ART procedures are suggested to alter the placental function and intrauterine growth trajectories. Epigenetic changes in maternal and foetal tissues are suggested to be the underlying mechanisms for these outcomes. Epigenetic regulation is known to evolve following fertilisation and before implantation and subsequently across gestation. During these critical periods of epigenetic 'programming', DNA methylation and chromatin remodelling influence the placental structure and function by regulating the expression of various genes. ART treatment coinciding with epigenetic 'programming' events during gametogenesis and early embryo development may alter the programming phases leading to long-term consequences. Thus, disruptions in placental development observed in ART pregnancies could be associated with altered epigenetic regulation of vital genes in the placenta. The review summarises available literature on the influence of ART procedures on epigenetic changes in the placenta.

MicroRNAs targeting peroxisome proliferator-activated receptor (PPAR) gene are differentially expressed in low birth weight placentae.

INTRODUCTION: Peroxisome proliferator-activated receptors (PPARs) are activated by natural ligands like fatty acids and influence placental angiogenesis and pregnancy outcome. However, the underlying molecular mechanisms are not clear. This study aims to investigate the association of maternal and placental fatty acid levels with DNA methylation and microRNA regulation of PPARs in the placentae of women delivering low birth weight (LBW) babies. METHODS: This study includes 100 women delivering normal birth weight (NBW) baby and 70 women delivering LBW baby. Maternal and placental fatty acids levels were estimated by gas chromatograph. Gene promoter methylation and mRNA expression of PPARs was analyzed using Epitect Methyl-II PCR assay kit and RT-PCR respectively. Expression of miRNAs targeting PPAR mRNA were analyzed using a Qiagen miRCURY LNA PCR Array on RT-PCR. RESULTS: Placental docosahexaenoic acid (DHA) levels and placental mRNA expression of PPARα and PPARγ were lower (p < 0.05 for all) in the LBW group. Differential expression of miRNAs (upregulated miR-33a-5p and miR-22-5p; downregulated miR-301a-5p, miR-518d-5p, miR-27b-5p, miR-106a-5p, miR-21-5p, miR-548d-5p, miR-17-5p and miR-20a-5p) (p < 0.05 for all) was observed in the LBW group. Maternal and placental polyunsaturated fatty acids and total omega-3 fatty acids were positively associated while saturated fatty acids were negatively associated with expression of miRNAs (p < 0.05 for all). Placental expression of miRNAs were positively associated with birth weight (p < 0.05 for all). DISCUSSION: Our data suggests that maternal fatty acid status is associated with changes in the placental expression of miRNAs targeting PPAR gene in women delivering LBW babies.

Fatty acids, inflammation and angiogenesis in women with gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is a metabolic disorder in pregnancy whose prevalence is on the rise. Reports suggest a likely association between inflammation and maternal GDM. A balance between pro and anti-inflammatory cytokines is necessary for the regulation of maternal inflammation system throughout pregnancy. Along with various inflammatory markers, fatty acids also act as pro-inflammatory molecules. However, studies reporting the role of inflammatory markers in GDM are contradictory, suggesting the need of more studies to better understand the role of inflammation in pregnancies complicated by GDM. Inflammatory response can be regulated by angiopoietins suggesting a link between inflammation and angiogenesis. Placental angiogenesis is a normal physiological process which is tightly regulated during pregnancy. Various pro and anti-angiogenic factors influence the regulation of the feto-placental vascular development. Studies evaluating the levels of angiogenic markers in women with GDM are limited and the findings are inconsistent. This review summarizes the available literature on fatty acids, inflammatory markers and angiogenesis in women with GDM. We also discuss the possible link between them and their influence on placental development in GDM.

Altered expression of nutrient transporters in syncytiotrophoblast membranes in preeclampsia placentae.

INTRODUCTION: Expression of nutrient transporters in the placenta affects fetal growth. This study reports the protein expression of nutrient transporters in the syncytial membranes [microvillous membrane (MVM) and basal membrane (BM)] of normotensive control and preeclampsia placentae. METHODS: Placentae were collected from fourteen normotensive control women and fourteen women with preeclampsia. The syncytiotrophoblast MVM and BM membranes were isolated. The protein expression of glucose transporter (GLUT1), vitamin B12 transporter (CD320) and fatty acid transporters (FATP2, FATP4) was assessed in both the membranes. RESULTS: Comparison between membranes demonstrates similar CD320 protein expression in normotensive group whereas, in preeclampsia placentae it was higher in the BM as compared to MVM (p < 0.05). FATP2&4 protein expression was higher in the BM as compared to their respective MVM fraction in both the groups (p < 0.01 for both). Comparison between groups demonstrates higher GLUT1 expression in the MVM (p < 0.05) and BM (p < 0.05) whereas lower CD320 expression in the MVM (p < 0.05) of preeclampsia placentae as compared to their respective membranes in normotensive control. Furthermore, GLUT1 protein expression was positively associated and CD320 protein expression was negatively associated with maternal body mass index (BMI) (p < 0.05 for both). No difference was observed in the FATP2&4 protein expression. However, FATP4 protein expression was negatively associated with maternal blood pressure (p < 0.05 for MVM; p = 0.060 for BM) and birth weight (p < 0.05 for both membranes). DISCUSSION: The current study for the first time demonstrates differential expression of various transporters in the syncytiotrophoblast membranes of the preeclampsia placentae which may influence fetal growth.

Influence of maternal one carbon metabolites on placental programming and long term health.

Studies have shown that the maternal nutrition during critical periods of development not only influences fetal growth but also plays a significant role in determining the risk of chronic disease in later life through developmental 'programming'. The placenta acts as a tool for 'programming' as it has the ability to adapt according to the maternal environment. There are morphological adaptations and also alterations in the expression of genes as a consequence of placental adaptations; which are critical for both placental and fetal development. Maternal nutrients especially the micronutrients (folate, vitamin B12) of the one carbon cycle and long chain polyunsaturated fatty acids (LCPUFA) are essential for placental and fetal growth and development. They are interconnected through the one carbon cycle and play a critical role in determining pregnancy outcome. A disturbed one carbon cycle leads to altered methylation of genes which play an important role in placental development and fetal growth. This review discusses the role of maternal one carbon metabolites and its influence on placental 'programming' and long term health.

Role of Placental Glucose Transporters in Determining Fetal Growth.

Maternal nutrient availability and its transport through the placenta are crucial for fetal development. Nutrients are transported to the fetus via specific transporters present on the microvillous (MVM) and basal membrane (BM) of the placenta. Glucose is the most abundant nutrient transferred to the fetus and plays a key role in the fetal growth and development. The transfer of glucose across the human placenta is directly proportional to maternal glucose concentrations, and is mediated by glucose transporter family proteins (GLUTs). Maternal glucose concentration influences expression and activity of GLUTs in the MVM (glucose uptake) and BM (glucose delivery). Alteration in the number and function of these transporters may affect the growth and body composition of the fetus. The thin-fat phenotype of the Indian baby (low ponderal index, high adiposity) is proposed as a harbinger of future metabolic risk. We propose that placental function mediated through nutrient transporters contributes to the phenotype of the baby, specifically that glucose transporters will influence neonatal fat. This review discusses the role of various glucose transporters in the placenta in determining fetal growth and body composition, in light of the above hypothesis.

Association of placental fatty acid desaturase 2 (FADS2) methylation with maternal fatty acid levels in women with preeclampsia.

INTRODUCTION: Biosynthesis of long-chain polyunsaturated fatty acids requires sequential activities of desaturases and elongases for conversion of fatty acid precursors to products. The delta-6 desaturase enzyme, encoded by FADS2 gene, is a rate limiting enzyme in this pathway. Alterations in D6D enzyme activity can lead to altered fatty acid profiles. OBJECTIVES: To examine differences in placental DNA methylation (DNAm) and expression of FADS2 gene in preeclampsia women compared to normal women and their association with maternal variables (plasma fatty acids, desaturase enzyme index, blood pressure), placental weight and birth outcomes. METHODS: DNAm and expression of FADS2 gene were examined in placentae of normotensive (n = 100) control and preeclampsia (n = 100) women using pyrosequencing and quantitative real-time PCR respectively. Women with preeclampsia included those delivering at term (n = 43, gestation ≥ 37 weeks; T-PE) or preterm (n = 57, gestation < 37 weeks; PT-PE). A total of 26 CpGs in FADS2 promoter and region around it, were analysed in two PCR reactions (region 1 and 2). RESULTS: Out of 13 CpGs in region 1, significant hypermethylation was noted at CpG3 in T-PE (p = 0.03) and of 13 CpGs in region 2, CpG2 (p = 0.008), CpG11 (p = 0.04), CpG12 (p = 0.001) were hypomethylated and CpG13 (p = 0.001) was hypermethylated in preeclampsia group, as compared to controls. FADS2 expression was lower in PT-PE as compared to controls (p = 0.04). DNAm at various CpGs in the FADS2 were associated with maternal plasma FADS2 enzyme index and also associated with maternal fatty acid levels. However, we did not observe any association of DNAm with maternal blood pressure, placental weight and birth outcomes. CONCLUSIONS: This study for the first time reports differential methylation of FADS2 and its association with impaired maternal fatty acid metabolism in preeclampsia and provides a mechanistic basis to our earlier observations of altered maternal LCPUFA levels in women with preeclampsia.