Placental Tissue Levels of Nonesterified Polyunsaturated Fatty Acids in Normal and Preeclamptic Pregnancies

Multidimensional Plasma Lipids Affect Preeclampsia/Eclampsia: A Mendelian Randomization Study

Circulating lipids play a crucial role during pregnancy and may impact various pregnancy-related diseases. This study employed a two-sample Mendelian randomization (MR) framework to investigate the causal relationship between alterations in multidimensional plasma lipid levels and the risk of preeclampsia or eclampsia, offering deeper insight into this association. The inverse variance weighted (IVW) method was utilized as the main analysis. Summary statistics from plasma lipidomics of 7174 Finnish individuals and summary data on preeclampsia/eclampsia from the FinnGen consortium involving 219 817 European participants were employed. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy. The study identified 17 lipid species from a total of 179 lipid species associated with susceptibility to preeclampsia/eclampsia. Notably, ten species, including six triacylglycerols (TAGs) (50:1, 48:1, 56:4, 49:2, 48:2, 54:3), a diacylglycerol (DAG) (16:1_18:1), and three sphingomyelins (SMs) (d36:1, d34:1, d38:1), were found to increase the risk of preeclampsia/eclampsia. Conversely, seven species, including five phosphatidylcholines (PCs) (16:1_20:4, O-18:1_20:4, 18:1_20:4, 16:0_20:4, 17:0_20:4) and two phosphatidylethanolamines (PEAs) (18:0_20:4, 16:0_20:4), all containing arachidonic acid (ARA) in the sn-2 position, were associated with a reduced risk of preeclampsia/eclampsia (all p < 0.05). The results of the stratified analysis were consistent with these findings. Furthermore, reverse MR analysis indicated that preeclampsia/eclampsia does not causally affect plasma levels of these lipids. Our findings established a causal relationship between specific plasma lipid species and modulation of preeclampsia/eclampsia risk, providing improved resolution for risk assessment and potential therapeutic targets in the disease.

Association between circulating unsaturated fatty acid and preeclampsia: a two-sample Mendelian randomization study

OBJECTIVE

In recent years, several studies have reported an association between unsaturated fatty acids (UFAs) and the risk of developing preeclampsia; however, its exact causal effect is unclear. This study assessed the causal association between circulating UFAs and preeclampsia.

METHODS

A two-sample Mendelian randomization (MR) study using publicly available genome-wide association study (GWAS) summary data for circulating UFA s (N = 114,999) and preeclampsia (N = 118,291) was performed. Single nucleotide polymorphisms (SNPs) significantly associated with exposure was selected as instrumental variables (IVs). The inverse variance weighted (IVW) test was used as the primary method for estimating causality in MR analysis, while MR pleiotropy residual sum and outlier (MR-PRESSO) and MR-Egger regression methods were used to assess horizontal pleiotropy. Cochran's Q test was used to evaluate heterogeneity among SNPs, and leave-one-out sensitivity analysis was used to determine the effect of individual SNPs on the results of the MR analysis. Bonferroni correction was used as a correction for multiple corrections.

RESULTS

Two-sample MR analysis suggested that the ratio of monounsaturated fatty acids (MUFAs) to total fatty acids (OR 1.150, 95% CI 1.006-1.315, p = 0.041), the ratio of polyunsaturated fatty acids (PUFAs) to total fatty acids (OR 0.805, 95% CI 0.658-0.986, p = 0.036) and the ratio of PUFAs to MUFAs (OR 0.807, 95% CI 0.694-0.938, p = 0.005) were causally associated with preeclampsia. After Bonferroni correction, the causal association between the ratio of polyunsaturated to MUFAs and preeclampsia remained statistically different.

CONCLUSIONS

This MR analysis provides evidence for a genetic causal association between circulating UFAs and preeclampsia.

Bidirectional Mendelian Randomization Analysis of Genetic Proxies of Plasma Fatty Acids and Pre-Eclampsia Risk

BACKGROUND

Previous studies have reported associations between fatty acids and the risk of pre-eclampsia. However, the causality of these associations remains uncertain. This study postulates a causal relationship between specific plasma fatty acids and pre-eclampsia or other maternal hypertensive disorders (PE-HTPs). To test this hypothesis, two-sample bidirectional Mendelian randomization (MR) analyses were employed to determine the causality effects.

METHODS

Single-nucleotide polymorphisms associated with PE-HTPs and fatty acids were obtained from a genome-wide association study (GWAS) of European ancestry. Bidirectional MR analyses were conducted using methods such as inverse variance weighted, MR-Egger, weighted median, simple mode, and weighted mode. Sensitivity analyses, including tests for heterogeneity, horizontal pleiotropy, and co-localization, were conducted to assess the robustness of MR results.

RESULTS

The analyses revealed causal relationships between PE-HTPs and several fatty acids, including monounsaturated fatty acid (MUFA), omega-6 fatty acid (n-6 FA), linoleic acid (LA), docosahexaenoic acid (DHA), and the PUFA/MUFA ratio. Genetically predicted higher risk of PE-HTPs was significantly associated with lower plasma n-6 FA (OR = 0.96, 95% CI: 0.93-0.99), particularly LA (OR = 0.95, 95% CI: 0.92-0.98). Conversely, increased DHA (OR = 0.86, 95% CI: 0.78-0.96) and a higher PUFA/MUFA ratio (OR = 0.86, 95% CI: 0.76-0.98) were associated with a reduced risk of PE-HTPs. Elevated MUFA levels (OR = 1.12, 95% CI: 1.00-1.25) were related to an increased risk.

CONCLUSIONS

This study provides robust genetic evidence supporting bidirectional causal relationships between PE-HTPs and specific plasma fatty acids, underscoring the critical role of fatty acid metabolism in maternal hypertensive disorders.

BMA-based Mendelian randomization identifies blood metabolites as causal candidates in pregnancy-induced hypertension

Pregnancy-induced hypertension (PIH), a prominent determinant of maternal mortality and morbidity worldwide, is hindered by the absence of efficacious biomarkers for early diagnosis, contributing to suboptimal outcomes. Here, we explored potential causal relationships between blood metabolites and the risk of PIH using Mendelian randomization (MR). We employed a two-sample univariable MR approach to empirically estimate the causal relationships between 249 circulating metabolites and PIH. Inverse variance weighted, MR-egger, weight median, simple mode, and weighted mode methods were used for causal estimates. The exposure-to-outcome directionality was confirmed with the MR Steiger test. The Bayesian model averaging MR (MR-BMA) method was applied to detect the predominant causal metabolic traits with alignment for pleiotropy effects. In the primary analysis, analyzing 249 metabolites, we identified 25 causally linked to PIH, including 11 lipid-related traits and 6 associated with fatty acid (un)saturation. Importantly, MR-BMA analyses corroborated the total concentration of branched-chain amino acids(total-BCAA) to be the highest rank causal metabolite, followed by leucine (Leu), phospholipids to total lipids ratio in medium LDL (M-LDL-PL-pct), and Val (all P < 0.05). The directionality of causality predicted by univariable MR and MR-BMA for these metabolites remained consistent. This study highlights the causal connection between metabolites and PIH risk. It highlighted BCAAs as the strongest causal candidates warranting further investigation. Since PIH typically occurs in the second and third trimesters, extending these findings could inform earlier strategies to reduce its risk. Directed acyclic graph of the MR framework investigating the causal relationship between metabolites and PIH. MR: Mendelian randomization; GIVs: genetic instrument variables; SNPs: single-nucleotide polymorphism; IVW: inverse variance weighted; WM: weighted median; PIH: pregnancy-induced hypertension; SM: significant metabolite; MR-BMA: Bayesian model averaging MR.

Integrated bioinformatic analysis reveals NOS2 as a novel ferroptosis-related biomarker for pre-eclampsia

BACKGROUND

Pre-eclampsia (PE) is a common condition in pregnancy; however, methods for early diagnosis and effective treatment options are lacking. Ferroptosis is a newly identified iron-dependent cell death pathway. The aim of this study was to investigate the role of ferroptosis-related genes in PE, the underlying mechanism, and their potential diagnostic value using a bioinformatics approach.

METHODS

We downloaded the GSE48424 and GSE98224 datasets from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between PE and healthy pregnancy samples were identified in the GSE48424 dataset and subjected to weighted gene co-expression network analysis; the most relevant modules were intersected with known ferroptosis-related genes to distinctly identify the role of ferroptosis in PE. We further searched transcription factors and microRNAs that are predicted to regulate these ferroptosis-related genes, and patients in the GSE48424 dataset were divided into two groups according to high or low expression of the key ferroptosis-related genes associated with PE. To obtain robust key ferroptosis-related genes in PE, we validated their expression levels in the external dataset GSE98224. Finally, the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay was utilized to access the expression of these genes in the PE and normal blood samples.

RESULTS

Six ferroptosis-related genes involved in PE were obtained by overlapping 3661 genes most associated with PE, 565 DEGs between PE and normal samples, and 259 known ferroptosis-related genes. Among these genes, patients with PE displaying lower expression levels of NOS2 and higher expression levels of PTGS2 had a higher ferroptosis potential index. The expression pattern of NOS2 was consistent in the GSE48424 and GSE98224 datasets. RT-qPCR data confirmed that NOS2 expression was more significantly elevated in patients with PE than in those with a normal pregnancy.

CONCLUSIONS

Our study explored the diagnostic value of ferroptosis-related genes in PE, and identified NOS2 as the key gene linking ferroptosis and PE, suggesting a new candidate biomarker for early PE diagnosis.

Placental dysfunction: The core mechanism for poor neurodevelopmental outcomes in the offspring of preeclampsia pregnancies

Preeclampsia (PE) is a leading condition threatening pregnant women and their offspring. The offspring of PE pregnancies have a high risk of poor neurodevelopmental outcomes and neuropsychological diseases later in life. However, the pathophysiology and pathogenesis of poor neurodevelopment remain undetermined. Abnormal placental functions are at the core of most PE cases, and recent research evidence supports that the placenta plays an important role in fetal brain development. Here, we summarize the relationship between abnormal fetal brain development and placental dysfunction in PE conditions, which include the dysfunction of nutrient and gas-waste exchange, impaired angiogenesis stimulation, abnormal neurotransmitter regulation, disrupted special protectors, and immune disorders. All these factors could lead to poor neurodevelopmental outcomes.

Comprehensive fatty acid fractionation profilling in preeclampsia: a case control study with multivariable analysis

Background

Preeclampsia is a complication during pregnancy characterised by new-onset hypertension and proteinuria that develops after 20 weeks of gestation. Dyslipidemia in pregnancy is correlated with an increased risk of preeclampsia. However, the dynamic changes in lipid metabolic product, particularly fatty acid fraction, in preeclampsia maternal circulation, are not well understood. This study aimed to investigate fatty acid fraction in preeclampsia maternal blood compared with normotensive normal pregnancy.

Methods

A total of 34 women who developed preeclampsia and 32 women with normotensive normal pregnancy were included in our case-control study. Maternal blood samples were collected for serum fatty acid fractions analysis and other biochemical parameters. Serum fatty acid fractions included long-chain polyunsaturated fatty acid (LCPUFA), monounsaturated fatty acid (MUFA), saturated fatty acid, and total fatty acid, measured with gas chromatography-mass spectrometry (GC-MS). The mean difference of fatty acid level was analysed using parametric and non-parametric bivariate analysis based on normality distributed data, while the risk of preeclampsia based on fatty acid fraction was analysed using a logistic regression model.

Results

Women with preeclampsia have lower high-density lipoprotein (53.97 ± 12.82 mg/dL vs. 63.71 ± 15.20 mg/dL, p = 0.006), higher triglyceride (284.91 ± 97.68 mg/dL vs. 232.84 ± 73.69 mg/dL, p = 0.018) than that in the normotensive group. Higher palmitoleic acid was found in women with preeclampsia compared to normotensive normal pregnancy (422.94 ± 195.99 vs. 325.71 ± 111.03 μmol/L, p = 0.037). The binary logistic regression model showed that pregnant women who had total omega-3 levels within the reference values had a higher risk of suffering preeclampsia than those with the higher reference value (odds ratio OR (95% CI): 8,5 (1.51–48.07), p = 0.015). Pregnant women who have saturated fatty acid within reference values had a lower risk for suffering preeclampsia than those in upper reference value (OR (95% CI): 0.21 (0.52–0.88), p = 0.032).

Conclusion

Overall, palmitoleic acid was higher in women with preeclampsia. Further analysis indicated that reference omega-3 in and high saturated fatty acid serum levels are characteristics of women with preeclampsia.

Neuroinflammatory Triangle Presenting Novel Pharmacological Targets for Ischemic Brain Injury

Ischemic stroke is one of the leading causes of morbidity and mortality globally. Hundreds of clinical trials have proven ineffective in bringing forth a definitive and effective treatment for ischemic stroke, except a myopic class of thrombolytic drugs. That, too, has little to do with treating long-term post-stroke disabilities. These studies proposed diverse options to treat stroke, ranging from neurotropic interpolation to venting antioxidant activity, from blocking specific receptors to obstructing functional capacity of ion channels, and more recently the utilization of neuroprotective substances. However, state of the art knowledge suggests that more pragmatic focus in finding effective therapeutic remedy for stroke might be targeting intricate intracellular signaling pathways of the 'neuroinflammatory triangle': ROS burst, inflammatory cytokines, and BBB disruption. Experimental evidence reviewed here supports the notion that allowing neuroprotective mechanisms to advance, while limiting neuroinflammatory cascades, will help confine post-stroke damage and disabilities.

The association between dietary fatty acid intake and the risk of developing preeclampsia: a matched case-control study

The association between dietary fat intake during pregnancy and the risk of developing preeclampsia has been examined in many epidemiological studies, but the results remain inconsistent. The aim of this study was to clarify this association in pregnant Chinese women. After conducting 1:1 matching, 440 pairs consisting of pregnant women with preeclampsia and hospital-based, healthy pregnant women matched by gestational week (± 1 week) and age (± 3 years) were recruited. A 79-item semi-quantitative food frequency questionnaire administered during face-to-face interviews was used to estimate the participants’ dietary intake of fatty acids. We found that the intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were inversely associated with the risk of developing preeclampsia. Compared with the lowest quartile intake, the multivariate-adjusted odds ratios (95% confidence interval) of the highest quartile intake were 0.42 (0.26–0.68, p-trend < 0.001) for EPA, 0.52 (0.3–0.83, p-trend = 0.005) for DHA, and 0.41 (0.19–0.88, p-trend = 0.007) for AA. However, we did not observe any significant associations between the intake of total fatty acids, saturated fatty acids, and mono-unsaturated fatty acids and the risk of developing preeclampsia. Our results showed that the dietary intake of long-chain polyunsaturated fatty acids (i.e., EPA, DHA, and AA) may protect pregnant Chinese women against the development of preeclampsia.

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.

Role of maternal nutrition and oxidative stress in placental telomere attrition in women with preeclampsia

Background: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.

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 Omega-3 Nutrition, Placental Transfer and Fetal Brain Development in Gestational Diabetes and Preeclampsia

Omega-3 fatty acids, particularly docosahexaenoic fatty acid (DHA), are widely recognized to impact fetal and infant neurodevelopment. The impact of DHA on brain development, and its inefficient synthesis from the essential alpha-linolenic acid (ALA), has led to recommended DHA intakes of 250-375 mg eicosapentaenoic acid + DHA/day for pregnant and lactating women by the Dietary Guidelines for Americans. Despite these recommendations, the intake of omega-3s in women of child-bearing age in the US remains very low. The low maternal status of DHA prior to pregnancy could impair fetal neurodevelopment. This review focuses on maternal omega-3 status in conditions of gestational diabetes mellitus (GDM) and preeclampsia, and the subsequent impact on placental transfer and cord blood concentration of omega-3s. Both GDM and preeclampsia are associated with altered maternal omega-3 status, altered placental omega-3 metabolism, reduced cord blood omega-3 levels and have an impact on neurodevelopment in the infant and on brain health later in life. These findings indicate lower DHA exposure of the developing baby may be driven by lower placental transfer in both conditions. Thus, determining approaches which facilitate increased delivery of DHA during pregnancy and early development might positively impact brain development in infants born to mothers with these diseases.

Fat intake during pregnancy and risk of preeclampsia: a prospective cohort study in Denmark

BACKGROUND

Previous studies suggest that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), may decrease the risk of preeclampsia, but many suffer from important methodological limitations.

METHODS

We prospectively examined the association between fat intake during pregnancy and preeclampsia and among 65,220 singleton pregnancies in the Danish National Birth Cohort (1996-2002). Women were asked to report their diet around gestation week 20 with a food frequency questionnaire. Preeclampsia diagnosis was obtained via linkage with the Danish National Patient Registry. We estimated relative risks (RR) and 95% confidence intervals (95% CI) of preeclampsia and severe preeclampsia according to fat intake using logistic regression models with generalized estimating equations to account for repeated pregnancies per woman while adjusting for potential confounders.

RESULTS

We documented 1302 cases of preeclampsia, including 301 cases of severe preeclampsia. Intake of long-chain omega-3 fatty acids was associated to preeclampsia. Women in the top quintile of DHA intake had a lower risk of preeclampsia (RR 0.67 (0.51-0.89)) and severe preeclampsia (RR 0.46 (0.25-0.83)) than women in the bottom quintile. Women who met daily recommended intake of EPA+DHA according to the Dietary Guidelines for Americans (≥250 mg/day), had a lower risk of severe preeclampsia (RR 0.77 (0.60-0.99)), but not of preeclampsia (RR 0.93 (0.82-1.05)). Conversely, ALA intake was associated with higher risk of severe preeclampsia (RR 1.71 (1.07-2.75)).

CONCLUSIONS

Higher intake of DHA is inversely related to preeclampsia and severe preeclampsia, whereas ALA increases the risk of severe preeclampsia among Danish women.

Maternal long chain polyunsaturated fatty acid status and pregnancy complications

Maternal nutrition plays a crucial role in influencing fetal growth and birth outcome. Any nutritional insult starting several weeks before pregnancy and during critical periods of gestation is known to influence fetal development and increase the risk for diseases during later life. Literature suggests that chronic adult diseases may have their origin during early life - a concept referred to as Developmental Origins of Health and Disease (DOHaD) which states that adverse exposures early in life "program" risks for later chronic disorders. Long chain polyunsaturated fatty acids (LCPUFA), mainly omega-6 and omega-3 fatty acids are known to have an effect on fetal programming. The placental supply of optimal levels of LCPUFA to the fetus during early life is extremely important for the normal growth and development of both placenta and fetus. Any alteration in placental development will result in adverse pregnancy outcome such as gestational diabetes mellitus (GDM), preeclampsia, and intrauterine growth restriction (IUGR). A disturbed materno-fetal LCPUFA supply is known to be linked with each of these pathologies. Further, a disturbed LCPUFA metabolism is reported to be associated with a number of metabolic disorders. It is likely that LCPUFA supplementation during early pregnancy may be beneficial in improving the health of the mother, improving birth outcome and thereby reducing the risk of diseases in later life.

Supplementation of docosahexaenoic acid (DHA) / Eicosapentaenoic acid (EPA) in a ratio of 1/1.3 during the last trimester of pregnancy results in EPA accumulation in cord blood

Omega-3 fatty acids (n-3 FA), specifically DHA, are associated with fetal growth and development. We aimed to determine the levels of DHA and EPA in cord serum after n-3 FA supplementation during the last trimester of pregnancy. Among 55 women, 23 were administered daily one capsule of n-3 FA supplement, involving DHA/EPA in a ratio of 1/1.3. Twenty nine women were enrolled as control group. Blood samples were collected at 22-24 weeks of gestation and at delivery. Fatty acids were analyzed with the method of GC-MS. Cord DHA level increased and EPA level decreased in both groups between the days of 22-24 and delivery. However, decrease in cord EPA level was significant in control group (p < 0.001) but not in supplement group (p > 0.05). Supplementation of DHA/EPA in a ratio of 1/1.3 during the last trimester of pregnancy caused higher cord EPA level compared to control group indicating an accumulation in umbilical cord.

Fatty acids profile in preterm Colostrum of Tunisian women. Association with selected maternal characteristics

Fatty acids (FA), especially arachidonic (AA, 20:4ω6) and docosahexaenoic (DHA, 22:6ω3) acids are critical for the health and development of infants. Colostrum FA composition has been examined in 101 lactating Tunisian women delivering prematurely using gas chromatography. Among polyunsaturated FA, linoleic acid predominated whereas each of the other polyunsaturated FA accounted for 1% or less of total FA. Colostrum AA and DHA contents were lower in women aged above 34 years compared to those less than 34 years. Preeclampsia was associated with lower DHA (0.40±0.22 vs. 0.53±0.27; p=0.018), but higher AA (1.14±0.44 vs. 0.93±0.30; p<0.006) and AA:DHA ratio (4.31±4.04 vs. 2.29±2.79; p<0.001). In multivariate analysis, colostrum DHA correlated with plasma DHA (β, 0.417; p=0.002), maternal age (β, -0.290; p=0.028) and preeclampsia (β, -0.270; p=0.042). Preterm colostrum FA profile in Tunisian women is comparable to those of other populations. Colostrum AA and DHA levels are altered in aged and pre-eclamptic women.

Reduced Maternal Erythrocyte Long Chain Polyunsaturated Fatty Acids Exist in Early Pregnancy in Preeclampsia

The present prospective study examines proportions of maternal erythrocyte fatty acids across gestation and their association with cord erythrocyte fatty acids in normotensive control (NC) and preeclamptic pregnancies. We hypothesize that maternal fatty acid status in early pregnancy influences fetal fatty acid stores in preeclampsia. 137 NC women and 58 women with preeclampsia were included in this study. Maternal blood was collected at 3 time points during pregnancy (16-20th weeks, 26-30th weeks and at delivery). Cord blood was collected at delivery. Fatty acids were analyzed using gas chromatography. The proportions of maternal erythrocyte α-linolenic acid, docosahexaenoic acid, nervonic acid, and monounsaturated fatty acids (MUFA) (p < 0.05 for all) were lower while total n-6 fatty acids were higher (p < 0.05) at 16-20th weeks of gestation in preeclampsia as compared with NC. Cord 18:3n-3, 22:6n-3, 24:1n-9, MUFA, and total n-3 fatty acids (p < 0.05 for all) were also lower in preeclampsia as compared with NC. A positive association was observed between maternal erythrocyte 22:6n-3 and 24:1n-9 at 16-20th weeks with the same fatty acids in cord erythrocytes (p < 0.05 for both) in preeclampsia. Our study for the first time indicates alteration in maternal erythrocyte fatty acids at 16th weeks of gestation which is further reflected in cord erythrocytes at delivery in preeclampsia.

Heterogeneity of the Fatty Acid Composition of Japanese Placentae for Determining the Perinatal Fatty Acid Status: a Methodological Study

Analysis of the placenta can be a useful way to determine the fatty acid (FA) status of pregnant women and neonates since this large organ can be obtained easily and non-invasively. Although several studies have been conducted on using placental tissue for FA analysis, the sampling methods have not been thoroughly examined. The aim of the present study was to determine a suitable method of sampling human placentae by focusing on their heterogeneity. Twenty-four placentae were collected from healthy pregnant Japanese women in the Miyagi Prefecture of Japan. Five of them were used to compare the FA composition between the peripheral area and the central area of the placentae. The other 19 were examined to determine differences in the FA composition between the fetal and maternal side. Placental tissue crude lipid was saponified, and methyl was esterified with 14% sodium boron trifluoride methanol for gas chromatography with flame ionization detector analysis. Fifty-six peaks were detected from the methyl esters of the placental total lipid, and 33 of those were identified as FA methyl esters. There were considerable variations in the FA composition, as the variation was low in the central parts and high in the peripheral parts of the placentae. The 18:1n-9 and 18:2n-6 levels were higher in the fetal side, whereas the 20:3n-6, 20:4n-6, and 22:6n-3 levels were higher in the maternal side. These findings indicate the presence of heterogeneity in the FA composition of human placenta, and they suggest the necessity for standardizing the sampling method so that the placental tissue can be used to determine the FA status.

Differential regional fatty acid distribution in normotensive and preeclampsia placenta

Background

Long chain polyunsaturated fatty acids (LCPUFAs) are biologically active fatty acids which regulate placental angiogenesis, inflammation, and oxidative stress. Abnormalities in these aspects have been associated with preeclampsia (PE). Further, placenta has a heterogeneous structure with differential vascularization across different regions. We therefore hypothesize that the distribution of fatty acids in various regions of the placenta is altered in PE leading to poor fetal outcome.

Methods

In this cross-sectional study we recruited 69 normotensive control (NC) and 44 women with PE. PE women were further classified as those delivered preterm (PTPE, n = 24) and at term (TPE, n = 20). Fatty acid levels were analyzed from placental samples from four different regions (CF—central fetal, PF—peripheral fetal, CM—central maternal and PM—peripheral maternal).

Results

In the NC placenta, AA levels were lower (p < 0.05) in CM as compared with CF region. However, such differences were not seen in the TPE and PTPE. In contrast, the DHA levels varied between regions only in the PTPE placenta. Between groups, DHA levels were lower (p < 0.05 for both) in the CM and CF regions of the PTPE as compared with NC. The levels of DHA in TPE placenta were similar to NC. AA levels were lower (p < 0.05 for both) in CF region of TPE and PF region of PTPE placenta than NC.

Conclusions

There is differential pattern of LCPUFA distribution across various regions of the NC, TPE and PTPE placenta. This may have implications for placental growth and development as well as transfer of LCPUFA to the fetus.

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There are regional differences in fatty acid levels in normal placenta.

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Regional fatty acid distribution is further affected in preeclampsia.

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Preterm preeclampsia placenta is more affected than term preeclampsia and control.

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DHA of peripheral fetal region positively associated with baby weight in preeclampsia.

Cytokines, angiogenic, and antiangiogenic factors and bioactive lipids in preeclampsia

Preeclampsia is a low-grade systemic inflammatory condition in which oxidative stress and endothelial dysfunction occurs. Plasma levels of soluble receptor for vascular endothelial growth factor (VEGFR)-1, also known as sFlt1 (soluble fms-like tyrosine kinase 1), an antiangiogenic factor have been reported to be elevated in preeclampsia. It was reported that pregnant mice deficient in catechol-O-methyltransferase (COMT) activity show a preeclampsia-like phenotype due to a deficiency or absence of 2-methoxyoestradiol (2-ME), a natural metabolite of estradiol that is elevated during the third trimester of normal human pregnancy. Additionally, autoantibodies (AT1-AAs) that bind and activate the angiotensin II receptor type 1 a (AT1 receptor) also have a role in preeclampsia. None of these abnormalities are consistently seen in all the patients with preeclampsia and some of them are not specific to pregnancy. Preeclampsia could occur due to an imbalance between pro- and antiangiogenic factors. VEGF, an angiogenic factor, is necessary for the transport of polyunsaturated fatty acids (PUFAs) to endothelial cells. Hence reduced VEGF levels decrease the availability of PUFAs to endothelial cells. This leads to a decrease in the formation of anti-inflammatory and angiogenic factors: lipoxins, resolvins, protectins, and maresins from PUFAs. Lipoxins, resolvins, protectins, maresins, and PUFAs suppress insulin resistance; activation of leukocytes, platelets, and macrophages; production of interleukin-6 and tumor necrosis factor-α; and oxidative stress and endothelial dysfunction; and enhance production of prostacyclin and nitric oxide (NO). Estrogen enhances the formation of lipoxin A4 and NO. PUFAs also augment the production of NO and inhibit the activity of angiotensin-converting enzyme and antagonize the actions of angiotensin II. Thus, PUFAs can prevent activation of angiotensin II receptor type 1 a (AT1 receptor). Patients with preeclampsia have decreased plasma phospholipid concentrations of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), the precursors of lipoxins (from AA), resolvins (from EPA and DHA), and protectins (from DHA) and prostaglandin E1 (PGE1 from DGLA: dihomo-γ-linolenic acid) and prostacyclin (PGI2 derived from AA). Based on these evidences, it is proposed that preeclampsia may occur due to deficiency of PUFAs and their anti-inflammatory products: lipoxins, resolvins, protectins, and maresins.

Altered maternal proportions of long chain polyunsaturated fatty acids and their transport leads to disturbed fetal stores in preeclampsia

Our previous cross-sectional studies have shown altered proportions of long chain polyunsaturated fatty acids (LCPUFA) in preeclampsia (PE) at the end of pregnancy when the pathology has already progressed. The present longitudinal study for the first time reports fatty acid proportions from 16th week of gestation till delivery and placental transport in PE. This is a hospital based study where women were recruited in early pregnancy. Maternal blood was collected at 3 time points i.e. T1=16-20th week, T2=26-30th week and T3=at delivery. Cord blood and placenta were collected at delivery. This study reports data on 140 normotensive control (NC) and 54 PE women. In PE we report lower proportions of DHA in maternal plasma at T1, cord plasma and placenta (p<0.05 for all). The mRNA levels of placental ∆5 desaturase, fatty acid transport proteins -1, -4, were lower (p<0.05 for all) in PE. There was also a positive association between cord and maternal plasma DHA and total omega-3 fatty acids at T1. This study demonstrates that women with PE have lower fatty acids stores at 16-20th week of gestation and lower placental synthesis and transport. It is likely that supplementation of omega-3 fatty acids during the 16-20th week of gestation may help in improving fatty acid status in infants born to mothers with PE.

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.

Dimethyl acetals, an indirect marker of the endogenous antioxidant plasmalogen level, are reduced in blood lipids of Sudanese pre-eclamptic subjects whose background diet is high in carbohydrate

In Sudanese women with (n = 60) and without (n = 65) pre-eclampsia, circulating lipids, plasma and red cell saturated and monounsaturated fatty (MUFA) acids and dimethyl acetals (DMAs) were investigated. DMAs are an indirect marker of levels of plasmalogens, endogenous antioxidants, which play a critical role in oxidative protection, and cholesterol homeostasis. The pre-eclamptics had higher C18:1n-9 (p < 0.001) and ΣMUFA (p < 0.01) in plasma free fatty acids, C16:1n-7, C18:1n-9, ΣMUFA; 16:0/16:1n-7 (p < 0.01) in erythrocyte choline phosphoglycerides (ePC) and 16:1n-7, 18:1n-7 and 16:0/16:1n-7 (p < 0.01) in erythrocyte ethanolamine phosphoglycerides (ePE). In contrast, the DMAs 18:0, 18:1 and ΣDMAs in ePE, and 16:0, 18:0 and ΣDMAs in ePC were reduced (p < 0.001) in the pre-eclamptic women. This study of pregnant women with high carbohydrate and low fat background diet suggests pre-eclampsia is associated with oxidative stress and enhanced activity of the microsomal enzyme stearyl-CoA desaturase (delta 9 desaturase), as assessed by palmitic/palmitoleic (C16:0/C16:n-1) and stearic/oleic (C18/C18:1n-9) ratios.

Maternal fatty acid status during pregnancy and lactation and relation to newborn and infant status

The present review of determinants of infant fatty acid status was undertaken as part of a conference on 'Fatty acid status in early life in low-income countries: determinants and consequences'. Emphasis is placed on the essential fatty acids, and particularly the physiologically important long chain polyunsaturated fatty acids (LCPUFAs) of 20 and 22 carbons. We are unaware of any studies of determinants of infant fatty acid status in populations with a cultural dietary pattern with low amounts of linoleic acid (LA, 18:2n-6) and α-linolenic acid (ALA,18:3n-3). Many reports suggest that there may be adverse health effects related to the increased proportion of LA in relation to ALA, which have occurred worldwide due to the increased availability of vegetable oils high in LA. The issue of dietary n-6 to n-3 balance may apply to infant fatty acid status both during fetal and post-natal life; however, this review focuses on the n-3 and n-6 LCPUFA, in particular, docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6), which are the predominant n-3 and n-6 LCPUFA found in cell membranes. The evidence that these fatty acids are preferentially transferred from maternal to fetal circulation across the placenta, and the sources and mechanisms for this transfer, are reviewed. We also address the sources of DHA and AA for the newborn including human milk DHA and AA and the factors that influence maternal DHA status and consequently the amount of DHA available for transfer to the fetus and infant via human milk.

Reduced placental docosahexaenoic acid levels associated with increased levels of sFlt-1 in preeclampsia

Our earlier studies, in preeclamptic women have shown altered levels of long chain polyunsaturated fatty acids (LCPUFA), essential constituents of the cell membrane lipids responsible for membrane stability as one of the key factors contributing to the pathophysiology of preeclampsia. We have also reported elevated levels of sFlt-1 in preeclampsia. The present study examines the levels of LCPUFA and their association with sFlt-1 levels in 69 pre-eclamptic women and 40 normotensive women. DHA and omega 3 fatty acid levels were lower (p<0.001) while arachidonic acid and omega 6 fatty acid levels were higher (p<0.05) in preeclamptic women as compared to normotensive women. Maternal plasma sFlt-1 levels were higher (p<0.05) in preeclamptic women and were negatively associated with DHA (p=0.008) and omega 3 fatty acids concentrations (p=0.031). Our results suggest that altered placental LCPUFA may result in altered membrane lipid fatty acid composition leading to increased release of sFlt-1 in circulation.

Role of nutrition in the risk of preeclampsia

Preeclampsia (PE) accounts for about one-quarter of the cases of maternal mortality and ranks second among the causes of pregnancy-associated maternal deaths in Canada and worldwide. The identification of an effective strategy to prevent PE is a priority and a challenge for research in obstetrics. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet in the etiology of PE has recently received increased attention. The objective of this paper is to provide an overview of the literature concerning 1) the current understanding of the pathogenesis of PE, 2) the biological plausibility and potential mechanisms underlying the associations between maternal dietary exposures, nutrition, and the risk of PE, and 3) the epidemiological findings of maternal nutrient intake in relation to the risk of PE.

Redox modulation of Ca2+ signaling in human endothelial and smooth muscle cells in pre-eclampsia

Pre-eclampsia (PE) is a leading cause of maternal hypertension in pregnancy and is associated with fetal growth restriction, premature birth, and fetal and maternal mortality. Activation and dysfunction of the maternal and fetal endothelium in PE appears to be a consequence of increased oxidative stress, resulting from elevated levels of circulating lipid peroxides. Accumulating evidence implicates reactive oxygen species (ROS) in the pathogenesis of vascular dysfunction in PE, perhaps involving a disturbance in intracellular Ca(2+) signaling. Several ion-transport pathways are highly sensitive to oxidative stress, and the resulting modulation of ion transport by ROS will affect intracellular Ca(2+) homeostasis. We review the evidence that changes in ion transport induced by ROS may be linked with abnormalities in Ca(2+)-mediated signal transduction, leading to endothelial and smooth muscle dysfunction in maternal and fetal circulations in PE. As dysregulation of Ca(2+) signaling in fetal umbilical endothelial cells is maintained in culture and embryonic, fetal, and postnatal development is affected by the cellular redox state, we hypothesize that impaired redox signaling in PE may influence "programming" of the fetal cardiovascular system and endothelial function in adulthood.

Higher de novo synthesized fatty acids and lower omega3- and omega6-long-chain polyunsaturated fatty acids in umbilical vessels of women with preeclampsia and high fish intakes

Umbilical veins (UV) and arteries (UA) of preeclamptic women in Curaçao harbor lower long-chain polyunsaturated fatty acids (LCP). The present aim was to test these findings in Mwanza (Tanzania), whose inhabitants have high LCPomega3 and LCPomega6 intakes from Lake Victoria fish. Women with preeclampsia (n=28) in Mwanza had lower PUFA and higher 20:0 in UV and UA, compared with normotensive/non-proteinuric controls (n=31). Their UV 22:6omega3, 22:4omega6, LCPomega6, omega6, and LCPomega3+omega6 were lower, while saturated FA, potentially de novo synthesized FA (Sigmade novo) and (Sigmade novo)/(LCPomega3+omega6) ratio were higher. Their UA had higher 16:1omega7, omega7, 18:0, and 16:1omega7/16:0. Umbilical vessels in Mwanza had higher 22:6omega3, LCPomega3, omega3, and 16:0, and lower 22:5omega6, 20:2omega6, 18:1omega9, and omega9, compared to those in Curaçao. Preeclampsia in both Mwanza and Curaçao is characterized by lower LCP and higher Sigmade novo. An explanation of this might be placental dysfunction, while the similarity of umbilical vessel FA-abnormalities in preeclamptic and diabetic pregnancies suggests insulin resistance as a common denominator.

A prospective study of early-pregnancy plasma malondialdehyde concentration and risk of preeclampsia

OBJECTIVES

Preeclampsia is associated with elevated plasma malondialdehyde concentration, but prospective data are scarce. We examined the relation between early-pregnancy plasma malondialdehyde and subsequent preeclampsia risk.

DESIGN AND METHODS

In a nested case-control analysis, we measured malondialdehyde concentrations in 22 women who developed preeclampsia and 711 who remained normotensive during pregnancy. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI). We repeated analyses after adjustment for early-pregnancy plasma lipid concentrations, which are related to preeclampsia risk and lipid peroxidation measures.

RESULTS

After adjustment for confounders, preeclampsia risk increased across tertiles of malondialdehyde concentration (trend P = 0.04). Further adjustment for triglyceride concentration slightly strengthened the association. Middle- and high-tertile malondialdehyde ORs were 3.2 (CI 0.8-12.2) and 4.2 (1.1-16.0) versus low-tertile exposure.

CONCLUSIONS

Early-pregnancy plasma malondialdehyde concentration is positively associated with subsequent preeclampsia risk independent of plasma lipid concentrations. These results support lipid peroxidation as an etiologic component of preeclampsia.