29 research outputs found
Hypoxia inducible factors (HIF1α and HIF3α) are differentially methylated in preeclampsia placentae and are associated with birth outcomes
No full textPreeclampsia 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 (β = 1.5%, p = 0.04). CpG8 in the promoter region of HIF1α, showed marginally significant hypomethylation in preterm preeclampsia compared to controls (β = - 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 (β = - 0.165, p = 0.024). Several CpGs in HIF1α were negatively associated with placental weight and birth outcomes including birth weight (β range = - 0.224-0.300) and birth length [β 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
Role of maternal nutrition and oxidative stress in placental telomere attrition in women with preeclampsia
No full textBackground:Maternal nutrition influences the growth and development of the fetus and influences pregnancy outcome. We have earlier demonstrated altered maternal nutrition and increased oxidative stress in women with preeclampsia. Oxidative stress is known to be associated with reduced telomere length and short telomere aggregates. Increased telomere attrition leads to increased cellular senescence and tissue ageing. Methods:The present review focuses on the role of maternal nutrition and oxidative stress in telomere attrition in preeclampsia. Results and Conclusion:Future studies need to examine the association between maternal nutritional status in early pregnancy, oxidative stress and telomere attrition in preeclampsia
Maternal one carbon metabolism through increased oxidative stress and disturbed angiogenesis can influence placental apoptosis in preeclampsia
No full textDifferential Expression of Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF) in Different Regions of Normal and Preeclampsia Placentae
No full textBackground: 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
Gestation dependant changes in angiogenic factors and their associations with fetal growth measures in normotensive pregnancy.
No full textEarlier studies indicate that altered angiogenesis at birth is associated with poor birth outcome in women with preeclampsia. Now, we hypothesize that the progressive gestation dependant changes in markers of angiogenesis will be more useful to predict birth weight early even in a normotensive pregnancy. This study for the first time examines the association of gestation dependant changes in the levels of maternal angiogenic factors in addition to their levels in cord with birth weight.Ninety two pregnant women were followed at three different time points: 16-20 weeks, 26-30 weeks and at delivery during pregnancy. Plasma levels of angiogenic and anti angiogenic factors were determined by commercial enzyme-linked immunosorbent assay (ELISA) kits.Maternal plasma VEGF levels increased (p<0.01) till the second time point and decreased (p<0.05) up to delivery while plasma sFlt-1 levels increased (p<0.01) at delivery. PlGF levels peaked (p<0.01) at second time point and decreased (p<0.01) at delivery. Cord plasma VEGF levels were higher (p<0.01) and sFlt-1 levels were lower (p<0.01) as compared to maternal values at all time points. Maternal plasma VEGF levels at first time point and PlGF levels at delivery were positively (p<0.05 and p<0.01 respectively), while sFlt-1/PlGF ratio at delivery was negatively associated (p<0.05) with birth weight.Levels of pro- and anti-angiogenic factors may be differentially regulated across gestation. Maternal VEGF levels at early gestation (16-20 weeks) may be predictive of birth weight in healthy term pregnancies
Matrix metalloproteinase-1 and -9 in human placenta during spontaneous vaginal delivery and caesarean sectioning in preterm pregnancy.
No full textPreterm birth is a major public health problem in terms of loss of life, long-term and short term disabilities worldwide. The process of parturition (both term and preterm) involves intensive remodelling of the extracellular matrix (ECM) in the placenta and fetal membranes by matrix metalloproteinases (MMPs). Our previous studies show reduced docosahexaenoic acid (DHA) in women delivering preterm. Further omega 3 fatty acids are reported to regulate MMP levels. This study was undertaken to examine the placental levels of MMPs and their association with placental DHA levels in women delivering preterm. The levels of MMP-1 and MMP-9 in 74 women delivering preterm (52 by spontaneous vaginal delivery and 22 by caesarean sectioning) and 75 women delivering at term (59 by spontaneous vaginal delivery and 16 by caesarean sectioning) were determined by enzyme-linked immunosorbent assay (ELISA) and their association with placental DHA was studied. Placental MMP-1 levels were higher (p<0.05) in women delivering preterm (both by spontaneous vaginal delivery and caesarean sectioning) as compared to those delivering at term. In contrast, placental MMP-9 levels in preterm pregnancies was higher (p<0.05) in women with spontaneous vaginal delivery while lower (p<0.05) in women delivering by caesarean sectioning. Low placental DHA was associated with higher placental MMP-9 levels. Our study suggests a differential effect of mode of delivery on the levels of MMPs from placenta. Further this study suggests a negative association of DHA and the levels of MMP-9 in human placenta although the mechanisms need further study
Altered Methylation and Expression Patterns of Genes Regulating Placental Angiogenesis in Preterm Pregnancy
No full textIntroduction
Altered angiogenesis has been implicated in the pathogenesis of various pregnancy complications, particularly preeclampsia. At present, there is a lack of data on the possible role of angiogenesis and its molecular mechanism in preterm pregnancy. We have previously reported reduced placental global DNA methylation levels in preterm pregnancy. Now, we have extended the study to examine plasma levels of angiogenic factors from maternal and cord blood and correlate them with placental promoter CpG methylation and messenger RNA expression of these angiogenic genes in preterm pregnancies.
Methods
We recruited 99 women delivering at term and 90 women delivering preterm. Plasma levels of angiogenic factors, vascular endothelial growth factor (VEGF), placental growth factor (PlGF), fms-related tyrosine kinase 1 (FLT-1), and kinase insert domain receptor (KDR) were analyzed by enzyme-linked immunosorbent assay. Expression levels and promoter CpG methylation of angiogenic genes in placentae were determined by quantitative real-time polymerase chain reaction and by the Sequenom EpiTYPER technology, respectively.
Results
Maternal VEGF and PlGF levels (P < .01 for both) were lower but soluble FLT-1 (sFLT-1) levels and sFLT-1–PlGF ratio (P < .05 for both) were higher in the preterm group. Placental VEGF expression (P < .05) was lower, and CpG site 14 in the VEGF promoter was hypermethylated (P < .05) in the preterm group. The KDR expression (P < .05) was higher in women delivering preterm.
Conclusions
Our study provides first evidence of differential placental CpG methylation patterns and expression of VEGF, FLT-1, and KDR genes in women delivering preterm. This may explain the possible mechanism for angiogenic imbalance in the pathophysiology of preterm pregnancy
Altered metabolism of maternal micronutrients and omega 3 fatty acids epigenetically regulate matrix metalloproteinases in preterm pregnancy: A novel hypothesis
No full textUnravelling the potential of angiogenic factors for the early prediction of preeclampsia
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