A potential role for free fatty acids in the pathogenesis of preeclampsia

Dietary risk factors for hypertensive disorders of pregnancy

OBJECTIVE

To assess whether diet quality and specific dietary components are associated with hypertensive disorders of pregnancy (HDP).

STUDY DESIGN

Nested case control study in a prospectively collected cohort of 450 participants with singleton pregnancies who completed the National Institutes of Health Diet Health Questionnaire II (DHQ-II) in the third trimester or within 3 months of delivery. Patients with fetal anomalies, conception by in-vitro fertilization, and deliveries at outside hospitals were excluded from the original prospective cohort study. Cases were patients diagnosed with HDP and controls were patients without HDP. Cases and controls were matched by BMI class in a 1:2 ratio. Exposures of interest were HEI-2015 score components and other DHQ-II dietary components including minerals, caffeine, and water. These dietary components were compared between cohorts using univariate analyses.

MAIN OUTCOME MEASURES

HEI-2015 total scores representing diet quality, component scores, and objective background data between patients with HDP and patients without HDP.

RESULTS

150 patients with HDP were matched to 300 controls without HDP. Baseline demographics were similar between groups, including BMI. Patients with HDP were less likely to have high quality diets (HEI ≥ 70) than controls (7.3 % v 15.7 %, P = 0.02). HDP were associated with significantly higher dairy, saturated fat, and sodium intake compared to controls. Other components were similar between groups.

CONCLUSION

Patients with HDP are more likely to have lower diet quality and higher consumption of sodium, dairy, and saturated fats. These results can be used to study antenatal diet modification in patients at high risk of HDP.

Biomarkers of Pre-eclampsia in Pregnant Women With Gestational Diabetes and Pre-existing Type 2 Diabetes: A Systematic Review

Pre-eclampsia (PE) is one of the leading causes of maternal and perinatal health morbidity, producing more than 4.6% of complications in pregnancy worldwide. This systematic review was conducted to determine the significance of specific biomarkers in predicting PE in gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (DM). The review measured and explained the significant abnormalities in lipids, blood glucose, cytokines, inflammatory markers, placental proteins, urinary proteins, and other serum biomarkers that contribute to the development of PE in GDM and type 2 DM populations. We searched CINAHL, EMBASE, Medline, Maternity and Infant care, Scopus, and Web of Science. Studies were included if they had a measurable component in the blood serum or urine of women who developed PE and suffered from GDM or pre-existing type 2 DM. A narrative synthesis was conducted instead of a meta-analysis due to the high heterogeneity of data from the studies. A total of 2,593 studies were screened, producing eight relevant studies. Twenty-seven different biomarkers were investigated from the study group of 40 to 1,344 participants. No single biomarker was identified; however, there is a need for further research on specific biomarkers of PE, especially in CRP, FABP4, and microalbuminuria in the GDM-PE group and calprotectin in the type 2 DM population. Many biomarkers were identified as practical in predicting PE when combined with other biomarkers and more data are required to verify the predictability of the diagnostic markers in pregnant women.

Dynamic changes in blood lipid levels and their associations with hypertensive disorders of pregnancy in twin pregnancy: A retrospective study

BACKGROUND

Little knowledge on the association of blood lipid levels with hypertensive disorders of pregnancy (HDP) in twin pregnancy.

OBJECTIVE

To investigate the association of blood lipid levels with HDP in twin pregnancy.

METHODS

This is a retrospective study in the Beijing Birth Cohort on patients followed between January 2014 and November 2021. A total of 2628 women pregnant with twins were included and divided into HDP (n = 565) and normal blood pressure (NBP, n = 2063) groups. HDP subtypes included gestational hypertension (GH, n = 190) and preeclampsia (PE, n = 375). Dynamic changes in blood lipid profiles and their associations with HDP were assessed.

RESULTS

Compared to NBP group, higher triglyceride (TG) and low-density lipoprotein  cholesterol (LDL-c) in the first (T1) and second trimesters (T2) existed in women with PE. In addition, TG increased significantly from T1 to T2, and high-density lipoprotein cholesterol (HDL-c) decreased significantly since T2 in women with PE, especially in women with early-onset PE and severe PE. Elevated TG and LDL-c were associated with HDP, mainly PE. In a subgroup analysis, higher TG or LDL-c increased the risk of HDP for underweight, overweight and primipara women.

CONCLUSIONS

In twin pregnancy, women with PE had higher TG and LDL-c, and elevated TG and LDL-c were associated with PE. A significant increase in TG or decrease in HDL-c were more prone to PE, especially early-onset PE and severe PE. It is helpful to monitor blood lipid levels in women pregnant with twins, especially in underweight, overweight, and primipara women.

Maternal Fibroblast Growth Factor 21 Levels Decrease during Early Pregnancy in Normotensive Pregnant Women but Are Higher in Preeclamptic Women-A Longitudinal Study

(1) Background: Fibroblast growth factor 21 (FGF-21) is an endocrine factor involved in glucose and lipid metabolism that exerts pleiotropic effects. The aim of this study was to investigate the serum FGF-21 profile in healthy and mild preeclamptic pregnant women at each trimester of pregnancy; (2) Methods: Serum FGF-21 levels were determined by ELISA in a nested case-control study within a longitudinal cohort study that included healthy (n = 54) and mild preeclamptic (n = 20) pregnant women, women at three months after delivery (n = 20) and eumenorrheic women during the menstrual cycle (n = 20); (3) Results: FGF-21 levels were significantly lower in the mid-luteal phase compared to the early follicular phase of the menstrual cycle in eumenorrheic women (p < 0.01). Maternal levels of FGF-21 were significantly lower in the first and second trimesters and peaked during the third trimester in healthy pregnant women (p < 0.01). Serum levels of FGF-21 in healthy pregnant were significantly lower in the first and second trimester of pregnancy compared with the follicular phase of the menstrual cycle and postpartum (p < 0.01). Serum FGF-21 levels were significantly higher in preeclamptic compared to healthy pregnant women during pregnancy (p < 0.01); (4) Conclusions: These results suggest that a peak of FGF-21 towards the end of pregnancy in healthy pregnancy and higher levels in preeclamptic women might play a critical role that contributes to protecting against the negatives effects of high concentrations of non-esterified fatty acids (NEFA) and hypertensive disorder. Furthermore, FGF-21 might play an important role in reproductive function in healthy eumenorrheic women during the menstrual cycle.

The relationship between free fatty acids and mitochondrial oxidative stress damage to trophoblast cell in preeclampsia

Aim

To investigate the effects of free fatty acids on mitochondrial oxidative stress and the pathogenesis of preeclampsia.

Methods

Human primary trophoblast cells at 6–8 weeks of gestation were retrieved and cultured to 70–80% confluence, then incubated in serum from women with a normal pregnancy (normal pregnancy group), women with preeclampsia (PE group), and a combination of serum from women with 24 h preeclampsia-like symptoms and free fatty acids (FFA group). Mitochondrial membrane potential was assessed by fluorescent dye concurrent with detection of membrane channel conversion pore activity by fluorescence microscope. Enzyme labeling instruments and RT-PCR were used to detect mitochondrial DNA (mtDNA) levels.

Results

The preeclampsia and free fatty acids groups both exhibited significantly higher levels of mitochondria oxidative stress damage when compared to the normal pregnancy group. However, no significant differences in mitochondrial oxidative stress damage were observed between the FFA and PE groups.

Conclusions

Serum free fatty acids might play an important role in the pathogenesis of preeclampsia by enhancing mitochondrial oxidative stress damage.

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.

Heparin Effects on Serum Gonadotropins

Introduction

Studies using lipid infusions to raise fatty acid levels require heparin to release lipoprotein lipase (LPL), thus calling into question the appropriate control infusion for this type of study: saline alone or saline plus heparin. We aimed to evaluate whether the addition of heparin alone, in doses needed to release LPL, would alter circulating free fatty acids (FFAs) and/or affect gonadotropins.

Materials and Methods

This was a secondary analysis using combined data from eumenorrheic normal-weight women subjected to "control" conditions in 1 of 2 separate studies. In 1 study, participants received saline alone (group 1) as a control, and in the other study participants received saline alone and/or saline plus heparin (groups 2-3) as a control. Both studies performed early follicular phase, frequent blood sampling. FSH and LH were compared across groups and in conditions with and without heparin. Linear mixed models were used to analyze the data.

Results

LH did not differ across any of the 3 groups. Estimated means (SE) for FSH differed between groups but this difference was marginal (P = .05) after adjusting for anti-Mullerian hormone and unrelated to heparin infusion (group 1: 4.47 IU/L [SE 1.19], group 2: 8.01 IU/L [SE 1.14], group 3: 7.94 IU/L [SE 1.13]).

Conclusions

Heparin does not exert major effects on gonadotropins when infused in quantities sufficient to release LPL. However, because it can release other vascular membrane-bound proteins, heparin should be considered part of the control infusions in lipid infusion studies where increased FFA levels are the goal.

Long-chain polyunsaturated fatty acid (LC-PUFA) status in severe preeclampsia and preterm birth: a cross sectional study

Long-Chain Polyunsaturated Fatty Acid (LCPUFA) is essential throughout pregnancy, since deficiency of LPUFA may linked to obstetrical complications. This study aimed to investigate LCPUFA status in severe preeclampsia and preterm birth. A cross sectional study was conducted in 104 pregnant women, which divided into normal pregnancy, severe preeclampsia and preterm birth groups. Serum percentage and concentration of total LCPUFA, omega-3, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), omega-6, linoleic acid (LA), and arachidonic acid (AA) were measured using gas chromatography/mass spectrometry. Receiver operating characteristic (ROC), bivariate and multivariate analysis were performed. Severe preeclampsia showed the highest concentration of total PUFA and the lowest DHA percentage, with significantly higher Omega-6/Omega-3 ratio (p = 0.004) and lower omega-3 index (p < 0.002) compared to control. Preterm birth showed the least omega-3 concentrations, with significantly low omega-6 derivates (LA (p = 0.014) and AA (p = 0.025)) compared to control. LCPUFA parameters have shown to increase the risk in both conditions, particularly ALA ≤ 53 µmol/L in preeclampsia with OR 5.44, 95%CI 1.16-25.42 and preterm birth with OR 4.68, 95%CI 1.52-14.38. These findings suggest that severe preeclampsia and preterm birth have an imbalance in LCPUFA status.

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.

NLRP3 inflammasome: a new therapeutic target for high-risk reproductive disorders?

ABSTRACT

The NOD-like receptor protein 3 (NLRP3) inflammasome is a key regulator of the host's immune response, and many immune and metabolic disorders are linked to its activation. This review aimed to investigate and clarify the relationship between this inflammasome and high-risk reproductive disorders. Papers cited here were retrieved from PubMed up to August 2020 using the keywords "NLRP3" or "NALP3", "caspase-1", "endometriosis", "gestational diabetes", "interleukin (IL)-18", "IL-1β", "pre-eclampsia (PE)", "preterm birth", "polycystic ovarian syndrome (PCOS)", "recurrent spontaneous abortion (RSA)", and combinations of these terms. The results show that NLRP3 inflammasome is associated with various high-risk reproductive disorders and many inflammatory factors are secreted during its activation, such as IL-1β induced during the development of endometriosis. PCOS is also associated with activation of the NLRP3 inflammasome, especially in overweight patients. It also participates in the pathogenesis of RSA and is activated in fetal membranes before preterm birth. The placentas of pregnant women with PE show higher expression of the NLRP3 inflammasome, and gestational diabetes mellitus occurs simultaneously with its activation. Current evidence suggest that the NLRP3 inflammasome plays an important role in female reproductive disorders. New treatment and management methods targeting it might help reduce the incidence of such disorders and improve neonatal outcomes.

Association of vitamin D with fatty acids in pregnancy

Preeclampsia is a pregnancy complication, associated with an increased risk of maternal and neonatal morbidity and mortality. The etiology of preeclampsia is not yet fully understood, although the current literature indicates an up regulation of inflammatory mediators. Vitamin D is known to have anti-inflammatory properties and influence vascular function. Fatty acids are also known to regulate inflammation in pregnancy. This study was carried out to explore the association of maternal vitamin D and fatty acids in pregnancy. The present study includes 69 normotensive control (NC) and 50 women with preeclampsia (PE). Maternal and cord serum 25-hydroxyvitamin D [25(OH)D] levels were lower (p<0.01for both) in women with PE compared to NC women. Maternal plasma total polyunsaturated fatty acids (PUFA) levels were lower (p<0.05) while levels of total saturated fatty acids (SFA) and total monounsaturated fatty acids (MUFA) were higher (p<0.05 for both) in women with PE. Cord erythrocyte PUFA levels were higher (p<0.01) in PE women. Maternal 25(OH)D levels were negatively associated with maternal systolic and diastolic BP (p<0.01 for both). Maternal 25(OH)D levels were positively associated with maternal total PUFA (p<0.01) and negatively associated with maternal total SFA (p<0.05), total MUFA (p<0.01). This study for the first time demonstrates an association of maternal vitamin D with fatty acid levels in pregnancy. Our results suggest that vitamin D and fatty acids may work in concert to regulate fetal growth.

Role of the NLRP3 Inflammasome in Preeclampsia

Reproduction involves tightly regulated series of events and the immune system is involved in an array of reproductive processes. Disruption of well-controlled immune functions leads to infertility, placental inflammation, and numerous pregnancy complications, including preeclampsia (PE). Inflammasomes are involved in the process of pathogen clearance and sterile inflammation. They are large multi-protein complexes that are located in the cytosol and play key roles in the production of the pivotal inflammatory cytokines, interleukin (IL)-1β and IL-18, and pyroptosis. The nucleotide-binding oligomerization domain, leucine-rich repeat-, and pyrin domain-containing 3 (NLRP3) inflammasome is a key mediator of sterile inflammation induced by various types of damage-associated molecular patterns (DAMPs). Recent evidence indicates that the NLRP3 inflammasome is involved in pregnancy dysfunction, including PE. Many DAMPs (uric acid, palmitic acid, high-mobility group box 1, advanced glycation end products, extracellular vesicles, cell-free DNA, and free fatty acids) are increased and associated with pregnancy complications, especially PE. This review focuses on the role of the NLRP3 inflammasome in the pathophysiology of PE.

Role of mammalian target of rapamycin signaling pathway in regulation of fatty acid oxidation in a preeclampsia-like mouse model treated with pravastatin

Background:

Fatty acid oxidation (FAO) disorder is involved in the pathogenesis of some cases of preeclampsia (PE). Several studies show that mammalian target of rapamycin (mTOR) signaling pathway is related to FAO. Pravastatin (Pra) can promote FAO in Nω-nitro-L-arginine methyl ester (L-NAME) PE-like mouse model in our previous study. This study aimed to investigate the effect of mTOR signaling pathway in PE-like model treated with Pra.

Methods:

Pregnant mice were randomly injected with L-NAME as PE-like model group or saline as control group respectively, from gestational 7th to 18th day. Giving Pra (L-NAME + Pra, Control + Pra, n = 8) or normal saline (NS; L-NAME + NS, Control + NS, n = 8) from gestational 8th to 18th day, the mice were sacrificed on day 18 and their liver and placental tissues were collected. Then the activation of mTOR and its substrates in the liver and placenta were detected. And the association between mTOR activation and serum free fatty acid (FFA) levels and the expression of long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) were evaluated using Pearson correlation test. Differences between groups were analyzed using independent t-test or one-way analysis of variance (ANOVA).

Results:

Both in the maternal liver and placenta, the activation of mTOR protein and its effect on substrates increased significantly in the L-NAME + NS group and decreased significantly in the L-NAME + Pra group. The p-mTOR/mTOR protein ratio decreased in the L-NAME + Pra group significantly than that in the L-NAME + NS group both in liver and placenta (liver: 0.74 ± 0.08 vs. 0.85 ± 0.06, t = 2.95, P < 0.05; placenta: 0.63 ± 0.06 vs. 0.77 ± 0.06, t = 4.64, P < 0.05). The activation of mTOR protein in the liver and placenta negatively correlated with the expression of LCHAD in the L-NAME + NS group (liver: r = −0.745, P < 0.05; placenta: r = −0.833, P < 0.05) and that in the maternal liver negatively correlated with the expression of LCHAD (r = −0.733, P < 0.05) and positively with the serum FFA levels (r = 0.841, P < 0.05) in the L-NAME + Pra group.

Conclusion:

The inhibition of mTOR signaling pathway might be involved in the regulation of FAO in mouse model treated with Pra.

Spontaneous superimposed preeclampsia: chronology and expression unveiled by temporal transcriptomic analysis

Preeclampsia (PE), a multifactorial pregnancy-specific syndrome accounting for up to 8% of pregnancy complications, is a leading cause of maternal and fetal morbidity and mortality. PE is also associated with long-term risk of hypertension and stroke for both mother and fetus. Currently, the only "cure" is delivery of the baby and placenta, largely because the pathogenesis of PE is not yet fully understood. PE is associated with impaired vascular remodeling at the maternal-fetal interface and placental insufficiency; however, specific factors contributing to this impairment have not been identified. To identify molecular pathways involved in PE, we examined temporal transcriptomic changes occurring within the uterus, uterine implantation sites, and placentae from the Dahl salt-sensitive (Dahl S) rat model of superimposed PE compared with Sprague Dawley (SD) rats. We hypothesized that targeted gene analysis and whole transcriptome analysis would identify genetic factors that contribute to development of the preeclamptic phenotype in the Dahl S rat and unveil novel biomarkers, therapeutic targets, and mechanistic pathways in PE. Quantitative real-time PCR (qRT-PCR) and whole genome microarray analysis were performed on isolated total RNA from uterus (day 0), uterine implantation sites (days 7 and 10), and placenta (days 14 and 20). We found 624, 332, 185, and 366 genes to be differentially expressed between Dahl S (PE) and SD (normal pregnancy) on days 0, 7, 10, and 14, respectively. Our data revealed numerous pathways that may play a role in the pathophysiology of spontaneous superimposed PE and allow for further investigation of novel therapeutic targets and biomarker development.

Disruption in the Regulation of Immune Responses in the Placental Subtype of Preeclampsia

Preeclampsia is a pregnancy-specific disorder, of which one of its major subtypes, the placental subtype is considered a response to an ischemic placental environment, impacting fetal growth and pregnancy outcome. Inflammatory immune responses have been linked to metabolic and inflammatory disorders as well as reproductive failures. In healthy pregnancy, immune regulatory mechanisms prevent excessive systemic inflammation. However, in preeclampsia, the regulation of immune responses is disrupted as a result of aberrant activation of innate immune cells and imbalanced differentiation of T-helper cell subsets creating a cytotoxic environment in utero. Recognition events that facilitate immune interaction between maternal decidual T cells, NK cells, and cytotrophoblasts are considered an indirect cause of the incomplete remodeling of spiral arteries in preeclampsia. The mechanisms involved include the activation of immune cells and the subsequent secretion of cytokines and placental growth factors affecting trophoblast invasion, angiogenesis, and eventually placentation. In this review, we focus on the role of excessive systemic inflammation as the result of a dysregulated immune system in the development of preeclampsia. These include insufficient control of inflammation, failure of tolerance toward paternal antigens at the fetal-maternal interface, and subsequent over- or insufficient activation of immune mediators. It is also possible that external stimuli, such as bacterial endotoxin, may contribute to the excessive systemic inflammation in preeclampsia by stimulating the release of pro-inflammatory cytokines. In conclusion, a disrupted immune system might be a predisposing factor or result of placental oxidative stress or excessive inflammation in preeclampsia. Preeclampsia can thus be considered a hyperinflammatory state associated with defective regulation of the immune system proposed as a key element in the pathological events of the placental subtype of this disorder.

Distribution of Fatty Acids and Lipids During Pregnancy

Maternal fatty acid and lipid metabolism undergoes changes during pregnancy to facilitate fetal growth and development. Different types of fatty acids have different roles in maintaining a successful pregnancy and they are incorporated into different forms of lipids for the purpose of storage and transport. This chapter aims to provide an understanding of the distribution and metabolism of fatty acids and lipids in the maternal, placental, and fetal compartments. We further describe how this distribution is altered in maternal obesity, preterm birth, and pregnancy complications such as gestational diabetes mellitus, preeclampsia, and intrauterine growth restriction.

Integration of metabolomic and transcriptomic networks in pregnant women reveals biological pathways and predictive signatures associated with preeclampsia

INTRODUCTION

Preeclampsia is a leading cause of maternal and fetal mortality worldwide, yet its exact pathogenesis remains elusive.

OBJECTIVES

This study, nested within the Vitamin D Antenatal Asthma Reduction Trial (VDAART), aimed to develop integrated omics models of preeclampsia that have utility in both prediction and in the elucidation of underlying biological mechanisms.

METHODS

Metabolomic profiling was performed on first trimester plasma samples of 47 pregnant women from VDAART who subsequently developed preeclampsia and 62 controls with healthy pregnancies, using liquid-chromatography tandem mass-spectrometry. Metabolomic profiles were generated based on logistic regression models and assessed using Received Operator Characteristic Curve analysis. These profiles were compared to profiles from generated using third trimester samples. The first trimester metabolite profile was then integrated with a pre-existing transcriptomic profile using network methods.

RESULTS

In total, 72 (0.9%) metabolite features were associated (p<0.01) with preeclampsia after adjustment for maternal age, race, and gestational age. These features had moderate to good discriminatory ability; in ROC curve analyses a summary score based on these features displayed an area under the curve (AUC) of 0.794 (95%CI 0.700, 0.888). This profile retained the ability to distinguish preeclamptic from healthy pregnancies in the third trimester (AUC:0.762 (95% CI 0.663, 0.860)). Additionally, metabolite set enrichment analysis identified common pathways, including glycerophospholipid metabolism, at the two time-points. Integration with the transcriptomic signature refined these results suggesting a particular role for lipid imbalance, immune function and the circulatory system.

CONCLUSIONS

These findings suggest it is possible to develop a predictive metabolomic profile of preeclampsia. This profile is characterized by changes in lipid and amino acid metabolism and dysregulation of immune response and can be refined through interaction with transcriptomic data. However validation in larger and more diverse populations is required.

Palmitic acid induces interleukin-1β secretion via NLRP3 inflammasomes and inflammatory responses through ROS production in human placental cells

Maternal obesity, a major risk factor for adverse pregnancy complications, results in inflammatory cytokine release in the placenta. Levels of free fatty acids are elevated in the plasma of obese human. These fatty acids include obesity-related palmitic acids, which is a major saturated fatty acid, that promotes inflammatory responses. Increasing evidence indicates that nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasomes mediate inflammatory responses induced by endogenous danger signals. We hypothesized that inflammatory responses associated with gestational obesity cause inflammation. To test this hypothesis, we investigated the effect of palmitic acid on the activation of NLRP3 inflammasomes and inflammatory responses in a human Sw.71 trophoblast cell line. Palmitic acid stimulated caspase-1 activation and markedly increased interleukin (IL)-1β secretion in Sw.71 cells. Treatment with a caspase-1 inhibitor diminished palmitic acid-induced IL-1β release. In addition, NLRP3 and caspase-1 genome editing using a CRISPR/Cas9 system in Sw.71 cells suppressed IL-1β secretion, which was stimulated by palmitic acid. Moreover, palmitic acid stimulated caspase-3 activation and inflammatory cytokine secretion (e.g., IL-6 and IL-8). Palmitic acid-induced cytokine secretion were dependent on caspase-3 activation. In addition, palmitic acid-induced IL-1β, IL-6, and IL-8 secretion was depended on reactive oxygen species (ROS) generation. In conclusion, palmitic acid caused activation of NLRP3 inflammasomes and inflammatory responses, inducing IL-1β, IL-6, and IL-8 secretion, which is associated with ROS generation, in human Sw.71 placental cells. We suggest that obesity-related palmitic acid induces placental inflammation, resulting in association with pregnancy complications.

Acute Respiratory Distress Syndrome: Role of Oleic Acid-Triggered Lung Injury and Inflammation

Lung injury especially acute respiratory distress syndrome (ARDS) can be triggered by diverse stimuli, including fatty acids and microbes. ARDS affects thousands of people worldwide each year, presenting high mortality rate and having an economic impact. One of the hallmarks of lung injury is edema formation with alveoli flooding. Animal models are used to study lung injury. Oleic acid-induced lung injury is a widely used model resembling the human disease. The oleic acid has been linked to metabolic and inflammatory diseases; here we focus on lung injury. Firstly, we briefly discuss ARDS and secondly we address the mechanisms by which oleic acid triggers lung injury and inflammation.

Correlation of long-chain fatty acid oxidation with oxidative stress and inflammation in pre-eclampsia-like mouse models

INTRODUCTION

Pre-eclampsia has been further recognized as a syndrome during pregnancy. Recent studies have found that long-chain fatty acid oxidation (FAO) disorders may be associated with some of pre-eclampsia. However, the mechanism remains unclear. In this study, we investigated the role of FAO and its relationship with oxidative stress and inflammatory signaling pathways in the pathogenesis of pre-eclampsia.

METHODS

PE-like groups included ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nω-nitro-l-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS), and antiphospholipid syndrome (APS) mouse model with β2GPI injection. The control group included wild-type mice with normal saline injection. Serum FFA was compared and placental and hepatic LCHAD, p47phox and NF-κB mRNA and protein were detected using real-time quantitative PCR and western blot.

RESULTS

FFA levels were significantly increased and were positively correlated with P47phox and NF-κB mRNA and protein expression in liver of all groups (p < 0.05), except LPS group (p < 0.05) as compared to control. LCHAD mRNA and protein expression in the liver and placenta was significantly increased in ApoC3+NS, ApoC3+L-NA, and β2GPI group, whereas decreased in L-NA group (p < 0.05) as compared to the control group. P47phox mRNA, NF-κB mRNA, and protein expression in the liver of all groups, except in LPS and in the placenta of β2GPI and L-NA groups, significantly increased (p < 0.05).

DISCUSSION

FAO disorders were involved in the pathogenesis of pre-eclampsia through oxidative stress and inflammatory endothelial cell injury.

Effect of oleic acid supplementation on prostaglandin production in maternal endometrial and fetal allantochorion cells isolated from late gestation ewes

INTRODUCTION

Elevated circulating non-esterified fatty acids including oleic acid (OA) are associated with many pregnancy related complications. Prostaglandins (PGs) play crucial roles during parturition. We investigated the effect of OA supplementation on PG production using an in vitro model of ovine placenta.

METHODS

Maternal endometrium (ME) and fetal allantochorion (FC) were collected in late pregnancy (day 135). Confluent cells were cultured in serum-free medium supplemented with 0, 20 or 100 μM OA and challenged with control medium, oxytocin (OT, 250 nM), lipopolysaccharide (LPS, 0.1 μg/ml) or dexamethasone (DEX, 5 μM). Spent medium was harvested at 2 and 24 h after challenge for quantifying PGs.

RESULTS

In ME cells OA increased PGE2 production moderately but attenuated PGF2α production leading to a doubling of the PGE2:PGF2α ratio (E:F) (P < 0.01). Without OA, both OT and LPS stimulated PG production for about 3-fold (P < 0.01) without changing the E:F ratio. In the ME cells challenged with OT, OA decreased both PGE2 and PGF2α production by up to 70% (P < 0.01) whereas in LPS treated cells OA increased the E:F ratio. In FC cells PGE2 production at 2 h was stimulated by 100 μM OA (P < 0.05). In these cells LPS caused a 3-fold increase in PGE2 (P < 0.01), an effect which was completely inhibited by DEX.

DISCUSSION

OA supplementation favours basal PGE2 production in both ME and FC. In ME OA increased E:F ratios and antagonized the stimulatory effect of OT on PG production. This suggests that raised circulating OA may affect both the initiation and progression of parturition.

Fatty acid oxidation changes and the correlation with oxidative stress in different preeclampsia-like mouse models

Background

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) expression is decreased in placenta of some cases of preeclampsia (PE) which may result in free fatty acid (FFA) increased. High FFA level will induce oxidative stress, so abnormal long-chain fatty acid-oxidation may participate in the pathogenesis of PE through oxidative stress pathway.

Methods

PE-like groups were ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nw-nitro-L-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS) and the antiphospholipid syndrome (APS) mouse model with β2GPI injection (ApoC3+NS, ApoC3+L-NA, L-NA, LPS and β2GPI groups). The control group was wild-type mice with normal saline injection. Except for β2GPI mice, the other mice were subdivided into pre-implantation (Pre) and mid-pregnancy (Mid) subgroups by injection time.

Results

All PE-like groups showed hypertension and proteinuria except ApoC3+NS mice only showed hypertension. Serum FFA levels increased significantly except in LPS group compared to controls (P<0.05). LCHAD mRNA and protein expression in the liver and placenta was significantly higher for ApoC3+NS, ApoC3+L-NA and β2GPI mice and lower for L-NA mice than controls (P<0.05) but did not differ between LPS mice and controls. P47phox mRNA and protein expression in the liver significantly increased in all PE-like groups except LPS group, while P47phox expression in the placenta only significantly increased in L-NA and β2GPI groups.

Conclusions

Abnormal long-chain fatty acid-oxidation may play a different role in different PE-like models and in some cases participate in the pathogenesis of PE through oxidative stress pathway.

Why does a high-fat diet induce preeclampsia-like symptoms in pregnant rats

Changes in neurotransmitter levels in the brain play an important role in epilepsy-like attacks after pregnancy-induced preeclampsia-eclampsia. Metabotropic glutamate receptor 1 participates in the onset of lipid metabolism disorder-induced preeclampsia. Pregnant rats were fed with a high-fat diet for 20 days. Thus, these pregnant rats experienced preeclampsia-like syndromes such as tension and proteinuria. Simultaneously, metabotropic glutamate receptor 1 mRNA and protein expressions were upregulated in the rat hippocampus. These findings indicate that increased sion of metabotropic glutamate receptor 1 promotes the occurrence of high-fat diet-induced preeclampsia in pregnant rats.

Biodiesel versus diesel exposure: enhanced pulmonary inflammation, oxidative stress, and differential morphological changes in the mouse lung

The use of biodiesel (BD) or its blends with petroleum diesel (D) is considered to be a viable approach to reduce occupational and environmental exposures to particulate matter (PM). Due to its lower particulate mass emissions compared to D, use of BD is thought to alleviate adverse health effects. Considering BD fuel is mainly composed of unsaturated fatty acids, we hypothesize that BD exhaust particles could induce pronounced adverse outcomes, due to their ability to readily oxidize. The main objective of this study was to compare the effects of particles generated by engine fueled with neat BD and neat petroleum-based D. Biomarkers of tissue damage and inflammation were significantly elevated in lungs of mice exposed to BD particulates. Additionally, BD particulates caused a significant accumulation of oxidatively modified proteins and an increase in 4-hydroxynonenal. The up-regulation of inflammatory cytokines/chemokines/growth factors was higher in lungs upon BD particulate exposure. Histological evaluation of lung sections indicated presence of lymphocytic infiltrate and impaired clearance with prolonged retention of BD particulate in pigment laden macrophages. Taken together, these results clearly indicate that BD exhaust particles could exert more toxic effects compared to D.

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.

Investigation of Preeclampsia Using Raman Spectroscopy

Preeclampsia is associated with increased perinatal morbidity and mortality. There have been numerous efforts to determine preeclampsia biomarkers by means of biophysical, biochemical, and spectroscopic methods. In this study, the preeclampsia and control groups were compared via band component analysis and multivariate analysis using Raman spectroscopy as an alternative technique. The Raman spectra of serum samples were taken from nine preeclamptic, ten healthy pregnant women. The Band component analysis and principal component analysis-linear discriminant analysis were applied to all spectra after a sensitive preprocess step. Using linear discriminant analysis, it was found that Raman spectroscopy has a sensitivity of 78% and a specificity of 90% for the diagnosis of preeclampsia. Via the band component analysis, a significant difference in the spectra of preeclamptic patients was observed when compared to the control group. 19 Raman bands exhibited significant differences in intensity, while 11 of them decreased and eight of them increased. This difference seen in vibrational bands may be used in further studies to clarify the pathophysiology of preeclampsia.

Pathological aspects of lipid peroxidation

Lipid peroxidation (LPO) product accumulation in human tissues is a major cause of tissular and cellular dysfunction that plays a major role in ageing and most age-related and oxidative stress-related diseases. The current evidence for the implication of LPO in pathological processes is discussed in this review. New data and literature review are provided evaluating the role of LPO in the pathophysiology of ageing and classically oxidative stress-linked diseases, such as neurodegenerative diseases, diabetes and atherosclerosis (the main cause of cardiovascular complications). Striking evidences implicating LPO in foetal vascular dysfunction occurring in pre-eclampsia, in renal and liver diseases, as well as their role as cause and consequence to cancer development are addressed.

Differences in maternal circulating fatty acid composition and dietary fat intake in women with gestational diabetes mellitus or mild gestational hyperglycemia

OBJECTIVE

We investigated the relationship between maternal circulating fatty acids (FAs) and dietary FA intake in pregnant women with gestational diabetes mellitus (GDM; n = 49), women with hyperglycemia less severe than GDM (impaired glucose challenge test [GCT] non-GDM; n = 80), and normal control subjects (n = 98).

RESEARCH DESIGN AND METHODS

A case-control design was nested within a prospective cohort of healthy pregnant women. Fasting concentrations of serum total FAs (enzymatic assay) and FA composition (gas chromatography-mass spectrometry) were determined at entry and the third trimester. Dietary fat intake data were obtained from 24-h recalls.

RESULTS

There was a graded increase among groups (control subjects, impaired GCT non-GDM, and GDM) during the third trimester for total FAs and individual FAs, including myristic, palmitic, palmitoleic, oleic, linoleic, linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic acids (P for trend <0.03 to P < 0.001). Similar relationships were observed at entry in total FAs and for four FAs (myristic, palmitic, palmitoleic, and eicosapentaenoic acids). Women with impaired GCT non-GDM with BMI >or=25 kg/m(2) had the highest levels of FAs at entry, whereas women with GDM with BMI >or=25 kg/m(2) had the highest levels during the third trimester, and all grouped FAs were significantly different from lean women with impaired GCT non-GDM or control subjects (P < 0.05). Dietary intake of polyunsaturated FAs was decreased, but saturated FAs were increased in GDM compared with impaired GCT non-GDM or control subjects (P < 0.05).

CONCLUSIONS

Abnormalities in fat metabolism are present in both GDM and impaired GCT non-GDM women. Reducing pregravid weight and altering diet might prevent the associated elevation of circulating FAs.

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.