Increased expression of fatty acid binding protein 4 in preeclamptic Placenta and its relevance to preeclampsia

Maternal hypertensive condition alters adipose tissue function and blood pressure sensitivity in offspring

Preeclampsia (PE) is characterized by hypertension, proteinuria, and fetal growth restriction during pregnancy, suggesting that the preeclamptic intrauterine environment may affect the growth and health of the offspring. This study aimed to how maternal hypertension affects male offspring growth, focusing on lipid metabolism and blood pressure in mice. Female mice were infused with angiotensin II (Ang II) on gestational day 12. Dysregulation and accumulation of lipid were observed in the placenta of Ang II-induced maternal hypertensive dams, associating with fetal growth restriction. Ang II-offspring showed lower birth weight than in the control-offspring. Isolated and differentiated adipocyte from neonatal mice of Ang II-dams showed higher Pparγ mRNA expression compared with the control group. Lower body weight tendency had continued in Ang II-offspring during long period, body weight of Ang II-offspring caught up the control-offspring at 16 weeks of age. The adipose tissue of Ang II-offspring in adult also showed higher Pparγ mRNA expression with the accumulation of neutrophils and inflammatory monocytes than in those control. In addition, Ang II-offspring had higher basal blood pressure and higher sensitivity to hypertensive stimuli than in the control-offspring. Taken together, maternal hypertension induced by Ang II changes placental function, causing a lower birth weight. These changes in the intrauterine environment may affect adipocyte function and blood pressure of offspring after growth.

Serum fatty acid binding protein 4 and Doppler of uterine artery ultrasound in the first trimester for the prediction of preeclampsia

The objective of this study was to determine the predictive value of serum fatty acid binding protein 4 (FABP4) combined with Doppler of the uterine artery in singleton pregnancy at gestational age (GA) 11-13+6 weeks for prediction of preeclampsia. A prospective observational study included singleton pregnant women at GA 11-13+6 weeks and was conducted at the Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, between December 2020 and April 2022. Serum FABP4 levels and Doppler of the uterine artery were performed. Pregnancy outcomes were recorded. The predictive values of these combined tests at the optimal cut-off values were determined to predict preeclampsia. A total of 330 participants with 15 cases of preeclampsia (4.5%) and 6 cases of them had preterm preeclampsia (GA < 37 weeks) (1.8%) were analyzed. Women with preeclampsia had significantly higher serum FABP4 levels than normal pregnant women (12.9 ± 6.5 ng/ml vs 10.1 ± 4.8 ng/ml, p = 0.034) but no difference in the mean pulsatility index (PI) of the uterine artery and the presence of an early diastolic notch. When using serum FABP4 levels greater than 1.0 multiple of the median of GA as a cut-off value to predict preeclampsia, combined with abnormal Doppler PI of the uterine artery, the sensitivity, specificity, positive predictive value, and negative predictive value were 73.3%, 47.3%, 6.2%, and 97.4%, respectively. This study demonstrated that serum FABP4 levels combined with Doppler of the uterine artery at GA 11-13+6 weeks were effective in predicting preeclampsia.

Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium

BACKGROUND

Placenta accreta spectrum disorders are associated with severe maternal morbidity and mortality. Placenta accreta spectrum disorders involve excessive adherence of the placenta preventing separation at birth. Traditionally, this condition has been attributed to excessive trophoblast invasion; however, an alternative view is a fundamental defect in decidual biology.

OBJECTIVE

This study aimed to gain insights into the understanding of placenta accreta spectrum disorder by using single-cell and spatially resolved transcriptomics to characterize cellular heterogeneity at the maternal-fetal interface in placenta accreta spectrum disorders.

STUDY DESIGN

To assess cellular heterogeneity and the function of cell types, single-cell RNA sequencing and spatially resolved transcriptomics were used. A total of 12 placentas were included, 6 placentas with placenta accreta spectrum disorder and 6 controls. For each placenta with placenta accreta spectrum disorder, multiple biopsies were taken at the following sites: placenta accreta spectrum adherent and nonadherent sites in the same placenta. Of note, 2 platforms were used to generate libraries: the 10× Chromium and NanoString GeoMX Digital Spatial Profiler for single-cell and spatially resolved transcriptomes, respectively. Differential gene expression analysis was performed using a suite of bioinformatic tools (Seurat and GeoMxTools R packages). Correction for multiple testing was performed using Clipper. In situ hybridization was performed with RNAscope, and immunohistochemistry was used to assess protein expression.

RESULTS

In creating a placenta accreta cell atlas, there were dramatic difference in the transcriptional profile by site of biopsy between placenta accreta spectrum and controls. Most of the differences were noted at the site of adherence; however, differences existed within the placenta between the adherent and nonadherent site of the same placenta in placenta accreta. Among all cell types, the endothelial-stromal populations exhibited the greatest difference in gene expression, driven by changes in collagen genes, namely collagen type III alpha 1 chain (COL3A1), growth factors, epidermal growth factor-like protein 6 (EGFL6), and hepatocyte growth factor (HGF), and angiogenesis-related genes, namely delta-like noncanonical Notch ligand 1 (DLK1) and platelet endothelial cell adhesion molecule-1 (PECAM1). Intraplacental tropism (adherent versus non-adherent sites in the same placenta) was driven by differences in endothelial-stromal cells with notable differences in bone morphogenic protein 5 (BMP5) and osteopontin (SPP1) in the adherent vs nonadherent site of placenta accreta spectrum.

CONCLUSION

Placenta accreta spectrum disorders were characterized at single-cell resolution to gain insight into the pathophysiology of the disease. An atlas of the placenta at single cell resolution in accreta allows for understanding in the biology of the intimate maternal and fetal interaction. The contributions of stromal and endothelial cells were demonstrated through alterations in the extracellular matrix, growth factors, and angiogenesis. Transcriptional and protein changes in the stroma of placenta accreta spectrum shift the etiologic explanation away from "invasive trophoblast" to "loss of boundary limits" in the decidua. Gene targets identified in this study may be used to refine diagnostic assays in early pregnancy, track disease progression over time, and inform therapeutic discoveries.

Maternal serum fatty acid binding protein-4 level is upregulated in fetal growth restriction with abnormal Doppler flow patterns

PURPOSE

This study aimed to determine fatty acid binding protein-4 (FABP-4) concentrations in maternal serum of fetal growth restriction (FGR) pregnancies and controls of normal pregnancies. Furthermore, we hypothesized that the alterations in FABP-4 levels might correlate with FGR severity.

METHODS

We performed this prospective case-control study with 83 pregnant women. The study groups included 26 FGR pregnancies without abnormal fetal Doppler flow patterns and 25 pregnancies complicated with FGR accompanied by abnormal fetal Doppler flow patterns.

RESULTS

The median serum FABP-4 concentrations were significantly higher in the FGR cases with abnormal Doppler flow pattern group (2.09 ng/mL) than in the FGR cases without abnormal Doppler flow pattern group (1.62 ng/mL) and the control group (1.20 ng/mL, p < 0.001). A significant negative correlation was observed between maternal serum FABP-4 levels and time to birth from blood sample collection (r = -0.356 and p = 0.001), gestational week at birth (r = -0.386 and p < 0.001), and birth weight (r = -0.394 and p < 0.001). A 1.35 ng/mL cut-off value of serum FABP-4 level could be used to discriminate FGR cases with a 78.4% sensitivity and 60.6% specificity. The optimal cut-off value of FABP-4 levels as an indicator for the diagnosis of FGR with abnormal Doppler flow pattern was estimated to be 1.76 ng/mL, which yielded a sensitivity of 84.0% and a specificity of 75.8%.

CONCLUSION

FABP-4 is a crucial biomarker in the diagnosis and determining the severity of pregnancies with restricted fetal growth. We consider that FABP-4 is a powerful, reliable, and unique biomarker to diagnose FGR pregnancies.

Elevated gestational testosterone impacts vascular and uteroplacental function

Maternal vascular adaptations to establish an adequate blood supply to the uterus and placenta are essential for optimal nutrient and oxygen delivery to the developing fetus in eutherian mammals, including humans. Numerous factors contribute to maintaining appropriate hemodynamics and placental vascular development throughout pregnancy. Failure to achieve or sustain these pregnancy-associated changes in women is strongly associated with an increased risk of antenatal complications, such as preeclampsia, a hypertensive disorder of pregnancy. The precise etiology of preeclampsia is unknown, but emerging evidence points to a potential role for androgens. The association between androgens and maternal cardiovascular and placental function merits particular attention due to the notable 2- to 3-fold elevated plasma testosterone (T) levels observed in preeclampsia. T levels in preeclamptic women positively correlate with vascular dysfunction, and preeclampsia is associated with increased androgen receptor (AR) levels in placental tissues. Moreover, animal studies replicating the pattern and magnitude of T increase observed in preeclamptic pregnancies have reproduced key features of preeclampsia, including gestational hypertension, endothelial dysfunction, heightened vasoconstriction to angiotensin II, impaired spiral artery remodeling, placental hypoxia, reduced nutrient transport, and fetal growth restriction. Collectively, these findings suggest that AR-mediated activity plays a significant role in the clinical presentation of preeclampsia. This review critically evaluates this hypothesis, considering both clinical and preclinical evidence.

PPARγ regulates lipid metabolism and viability of sheep trophoblast cells

Peroxisome proliferator-activated receptor γ (PPARγ) is highly expressed in trophoblast tissues in pregnancy during which the protein participates in diverse events, including embryo implantation and placental formation. However, little is known about the role of PPARγ in embryonic development. This study investigated the function of PPARγ in sheep trophoblast cells. The coding sequence of sheep PPARγ encoded 475 amino acids and included one synonymou mutation compared with the sheep reference sequence for PPARγ. The PPARγ protein was localized in the nucleus and cytoplasm of sheep trophoblasts. The relative expression of PPARγ was elevated in cells treated with rosiglitazone and reduced following administration of GW9662. Activation of PPARγ promoted cell proliferation and mobility, but inhibited apoptosis. In addition, stimulation of PPARγ promoted the expression of lipid metabolism-related genes FABP4 and PLIN2. The expression of prostaglandin metabolism-related genes PLA2G4A, PTGS2 and PTGES also was upregulated significantly in trophoblast cells when PPARγ was activated. In contrast, activation of PPARγ did not impact expression of the prostaglandin-related genes PGFS and SLCO2A1. At the same time, activation of PPARγ activity increased the ratio of PGE2 to PGF2α. Furthermore, fluorescence labelling showed that the numbers of cell lipid droplets increased after stimulation of PPARγ activity, but decreased when PPARγ was inhibited. In conclusion, PPARγ is critical for the regulation of lipid metabolism and prostaglandin synthesis and secretion in sheep trophoblast cells and also has a potent effect on cell proliferation and viability.

Placental Inflammation Significantly Correlates with Reduced Risk for Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a blinding condition affecting preterm infants, is an interruption of retinal vascular maturation that is incomplete when born preterm. Although ROP demonstrates delayed onset following preterm birth, representing a window for therapeutic intervention, there are no curative or preventative measures available for this condition. The in utero environment, including placental function, is increasingly recognized for contributions to preterm infant disease risk. The current study identified a protective association between acute placental inflammation and preterm infant ROP development using logistic regression, with the most significant association found for infants without gestational exposure to maternal preeclampsia and those with earlier preterm birth. Expression analysis of proteins with described ROP risk associations demonstrated significantly decreased placental high temperature requirement A serine peptidase-1 (HTRA-1) and fatty acid binding protein 4 protein expression in infants with acute placental inflammation compared with those without. Within the postnatal peripheral circulation, HTRA-1 and vascular endothelial growth factor-A demonstrated inverse longitudinal trends for infants born in the presence of, compared with absence of, acute placental inflammation. An agnostic approach, including whole transcriptome and differential methylation placental analysis, further identify novel mediators and pathways that may underly protection. Taken together, these data build on emerging literature showing a protective association between acute placental inflammation and ROP development and identify novel mechanisms that may inform postnatal risk associations in preterm infants.

DHA supplementation and pregnancy complications

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

Adipokine chemerin overexpression in trophoblasts leads to dyslipidemia in pregnant mice: implications for preeclampsia

BACKGROUND

The adipokine chemerin regulates adipogenesis and the metabolic function of both adipocytes and liver. Chemerin is elevated in preeclamptic women, and overexpression of chemerin in placental trophoblasts induces preeclampsia-like symptoms in mice. Preeclampsia is known to be accompanied by dyslipidemia, albeit via unknown mechanisms. Here, we hypothesized that chemerin might be a contributor to dyslipidemia.

METHODS

Serum lipid fractions as well as lipid-related genes and proteins were determined in pregnant mice with chemerin overexpression in placental trophoblasts and chemerin-overexpressing human trophoblasts. In addition, a phospholipidomics analysis was performed in chemerin-overexpressing trophoblasts.

RESULTS

Overexpression of chemerin in trophoblasts increased the circulating and placental levels of cholesterol rather than triglycerides. It also increased the serum levels of lysophosphatidic acid, high-density lipoprotein cholesterol (HDL-C), and and low-density lipoprotein cholesterol (LDL-C), and induced placental lipid accumulation. Mechanistically, chemerin upregulated the levels of peroxisome proliferator-activated receptor g, fatty acid-binding protein 4, adiponectin, sterol regulatory element-binding protein 1 and 2, and the ratio of phosphorylated extracellular signal-regulated protein kinase (ERK)1/2 / total ERK1/2 in the placenta of mice and human trophoblasts. Furthermore, chemerin overexpression in human trophoblasts increased the production of lysophospholipids and phospholipids, particularly lysophosphatidylethanolamine.

CONCLUSIONS

Overexpression of placental chemerin production disrupts trophoblast lipid metabolism, thereby potentially contributing to dyslipidemia in preeclampsia.

Hyperandrogenism diminishes maternal-fetal fatty acid transport by increasing FABP 4-mediated placental lipid accumulation

Long-chain polyunsaturated fatty acids (LCPUFAs) are critical for fetal brain development. Infants born to preeclamptic mothers or those born growth restricted due to placental insufficiency have reduced LCPUFA, and are at higher risk for developing neurodevelopmental disorders. Since plasma levels of testosterone (T) and fatty acid-binding protein 4 (FABP4) are elevated in preeclampsia, we hypothesized that elevated T induces the expression of FABP4 in the placenta leading to compromised transplacental transport of LCPUFAs. Increased maternal T in pregnant rats significantly decreased n-3 and n-6 LCPUFA levels in maternal and fetal circulation, but increased their placental accumulation. Dietary LCPUFAs supplementation in T dams increased LCPUFA levels in the maternal circulation and further augmented placental storage, while failing to increase fetal levels. The placenta in T dams exhibited increased FABP4 mRNA and protein levels. In vitro, T dose-dependently upregulated FABP4 transcription in trophoblasts. T stimulated androgen receptor (AR) recruitment to the androgen response element and trans-activated FABP4 promoter activity, both of which were abolished by AR antagonist. T in pregnant rats and cultured trophoblasts significantly reduced transplacental transport of C14-docosahexaenoic acid (DHA) and increased C14-DHA accumulation in the placenta. Importantly, FABP4-overexpression by itself in pregnant rats and trophoblasts increased transplacental transport of C14-DHA with no significant placental accumulation. T exposure, in contrast, inhibited this FABP4-mediated effect by promoting C14-DHA placental accumulation. In summary, our studies show that maternal hyperandrogenism increases placental FABP4 expression via transcriptional upregulation and preferentially routes LCPUFAs toward cellular storage in the placenta leading to offspring lipid deficiency.

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

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

Fatty acids in normal and pathological pregnancies

Long chain fatty acids, namely omega-3 and omega-6, are essential fatty acids and are necessary for proper pregnancy progression and fetal growth and development. Maternal fatty acid consumption and release of fatty acids from lipid stores provide increased availability of fatty acids for the placenta to transport to the growing fetus. Both omega-3 and omega-6 fatty acids are then utilized for generation of signaling molecules, such as eicosanoids, and for promoting of growth and developmental, most notably in the nervous system. Perturbations in fatty acid concentration and fatty acid signaling have been implicated in three major pregnancy complications - gestational diabetes, preeclampsia, and preterm birth. In this review we discuss the growing literature surrounding the role of fatty acids in normal and pathological pregnancies. Differences in maternal, placental, and fetal fatty acids and molecular regulation of fatty acid signaling and transport are presented. A look into novel fatty acid-based therapies for each of the highlighted disorders are discussed, and may present exciting bench to bedside alternatives to traditional pharmacological intervention.

Lipid signatures reflect the function of the murine primary placentation

The placenta regulates maternal-fetal communication, and its defect leads to significant pregnancy complications. The maternal and embryonic circulations are primitively connected in early placentation, but the function of the placenta during this developmentally essential period is relatively unknown. We thus performed a comparative proteomic analysis of the placenta before and after primary placentation and found that the metabolism and transport of lipids were characteristically activated in this period. The placental fatty acid (FA) carriers in specific placental compartments were upregulated according to gestational age, and metabolomic analysis also showed that the placental transport of FAs increased in a time-dependent manner. Further analysis of two mutant mice models with embryonic lethality revealed that lipid-related signatures could reflect the functional state of the placenta. Our findings highlight the importance of the nutrient transport function of the primary placenta in the early gestational period and the role of lipids in embryonic development.

Galectin-14 Promotes Trophoblast Migration and Invasion by Upregulating the Expression of MMP-9 and N-Cadherin

Galectin-14 is specifically expressed in placental trophoblasts, and its expression is reduced in trophoblasts retrieved from the cervix of women destined to develop early pregnancy loss. However, the roles of galectin-14 in regulating trophoblasts and in the pathogenesis of pregnancy complication have never been investigated. In the current research, we aimed to investigate the roles of galectin-14 in the regulation of trophoblasts. Tissues of the placenta and villi were collected. Primary trophoblasts and human trophoblast cell line HTR-8/SVneo were used. Western blotting and RT-PCR were used to quantify gene expression. The siRNA-mediated galectin-14 knockdown and lentivirus-mediated overexpression were performed to manipulate the gene expression in trophoblasts. Transwell migration and invasion assays were used to evaluate cell migration and invasion capacity. Gelatin zymography was used to determine the gelatinase activity. Galectin-14 was significantly decreased in the villi of early pregnancy loss and the placenta of preeclampsia. Knockdown of galectin-14 in primary trophoblasts inhibited cell migration and invasion, downregulated the expression of matrix metalloproteinase (MMP)-9 and N-cadherin, the activity of MMP-9, and decreased the phosphorylation of Akt. Meanwhile, the overexpression of galectin-14 in HTR-8/SVneo promoted cell migration and invasion, upregulated the expression of MMP-9 and N-cadherin, the activity of MMP-9, and increased the phosphorylation of Akt. Increased Akt phosphorylation promoted cell migration and invasion and upregulated the expression and activity of MMP-9, while decreased Akt phosphorylation inhibited cell migration and invasion and downregulated the expression and activity of MMP-9. Thus, galectin-14 promotes trophoblast migration and invasion by enhancing the expression of MMP-9 and N-cadherin through Akt phosphorylation. The dysregulation of galectin-14 is involved in the pathogenesis of early pregnancy loss and preeclampsia.

Decidua basalis and acute atherosis: Expression of atherosclerotic foam cell associated proteins

INTRODUCTION

Uteroplacental acute atherosis is frequently observed in preeclampsia, and shares features with early atherosclerotic lesions, including artery wall foam cells. The lipid-associated proteins FABP4 (fatty acid binding protein 4), perilipin-2, and LOX-1 (lectin-like oxidized LDL-receptor 1) are involved in atherosclerotic foam cell formation. Increased levels of these proteins have been associated with preeclampsia systemically and in placental tissue. Their role in acute atherosis is yet unidentified. Our aim was to describe the presence of these proteins in acute atherosis, and compare our findings to what is known in early atherosclerotic lesions.

METHODS

Serial sections of decidua basalis tissue from 12 normotensive (4 with acute atherosis) and 23 preeclamptic pregnancies (16 with acute atherosis) were stained with HE and immunostained for CK7, CD68, FABP4, perilipin-2, and LOX-1. Artery wall and perivascular protein expression was assessed in 190 spiral artery sections; 55 with acute atherosis.

RESULTS

Acute atherosis foam cells were commonly positive for perilipin-2 (55%), less often for FABP4 (13%), and never for LOX-1. LOX-1 was frequently observed in intramural trophoblasts of normal spiral arteries. Perivascularly, LOX-1 positivity of decidual stromal cells surrounding arteries with acute atherosis was significantly increased as compared to arteries lacking acute atherosis (38% vs. 15%, p < 0.001).

DISCUSSION

We found that perilipin-2 and FABP4 are expressed by acute atherosis foam cells, similar to atherosclerosis, supporting possible shared pathways for foam cell generation. Unlike atherosclerosis, LOX-1 is not present in acute atherosis, possibly explained by pregnancy-specific routes to decidua basalis foam cell generation.

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.

Stimulation of soluble guanylate cyclase diminishes intrauterine growth restriction in a rat model of placental ischemia

Placental ischemia in preeclampsia (PE) results in hypertension and intrauterine growth restriction (IUGR). Stimulation of soluble guanylate cyclase (sGC) reduces blood pressure in the clinically relevant reduced uterine perfusion pressure (RUPP) rat model of PE, implicating involvement in RUPP-induced hypertension. However, the contribution of sGC in the development of IUGR in PE is not known. Thus, this study demonstrated the efficacy of Riociguat, an sGC stimulator, in IUGR reversion in the RUPP rat model of PE, and tested the hypothesis that improvement in fetal weight occurs in association with improvement in placental perfusion, placental morphology, and placental nutrient transport protein expression. Sham or RUPP surgery was performed at gestational day 14 (G14) with administration of vehicle (Sham or RUPP) or the sGC stimulator (Riociguat, 10 mg/kg/day sc; sGC-treated) until G20. Fetal weight was reduced (P = 0.004) at G20 in RUPP but not in sGC-treated RUPP compared with Sham, the control group. At G20, uterine artery resistance index (UARI) was increased (P = 0.010) in RUPP, indicating poor placental perfusion; proportional junctional zone surface area was elevated (P = 0.035), indicating impaired placental development. These effects were ameliorated in sGC-treated RUPP. Placental protein expression of nutrient transporter heart fatty acid-binding protein (hFABP) was increased (P = 0.008) in RUPP but not in sGC-treated RUPP, suggesting a compensatory mechanism to maintain normal neurodevelopment. Yet, UARI (P < 0.001), proportional junctional zone surface area (P = 0.013), and placental hFABP protein expression (P = 0.008) were increased in sGC-treated Sham, suggesting a potential adverse effect of Riociguat. Collectively, these results suggest sGC contributes to IUGR in PE.

Fetal macrosomia in a Hispanic/Latinx predominant cohort and altered expressions of genes related to placental lipid transport and metabolism

Fetal overgrowth, termed fetal macrosomia when birth weight is greater than 4000 grams, is the major concern in the treatment of gestational diabetes mellitus (GDM). However, to date, the underlying mechanisms of fetal macrosomia have not been understood completely. Placental lipid metabolism is emerging as a critical player in fetal growth. In this study, we hypothesized that fatty acid transport and metabolism in the placental tissue was impaired in GDM women, dependent on fetal sex. To test this hypothesis, we analyzed the incidence of GDM, fetal macrosomia, and obesity in a large cohort consisting of 17995 pregnant subjects and majority of subjects being Hispanic/Latinx, and investigated expression of genes related to lipid transport and metabolism in placenta from obese women with or without GDM, and with or without fetal macrosomia. The main findings include: 1) There is a higher incidence of GDM and obesity in Hispanic subjects compared to non-Hispanic subjects, but not fetal macrosomia; 2) Expressions of most of genes related to placental lipid transport and metabolism are not altered by the presence of GDM, fetal macrosomia, or fetal sex; 3) Expression of FABP4 is increased in obese women with GDM and fetal macrosomia, and this occurred in male placentas; 4) Expression of LPL is decreased in obese women with GDM despite fetal macrosomia, and this occurred in male placentas; 5) Expression of ANGPTL3 is decreased in obese women with GDM and fetal macrosomia, but is not altered when fetal sex is included in the analysis. This study indicates that there is race disparity in GDM with higher incidence of GDM in obese Hispanic women, although fetal macrosomia disparity is not present. Moreover, altered placental lipid transport may contribute to fetal overgrowth in obese women with GDM.

The role of serum adipokine levels in preeclampsia: A systematic review

BACKGROUND

Preeclampsia represents a major pregnancy complication, associated with high rates of perinatal morbidity. The aim of this systematic review is to accumulate current literature evidence in order to examine the pattern of serum adipokine levels among preeclamptic women and asses their potential efficacy in the prediction of the disease.

METHODS

Medline, Scopus, CENTRAL, Clinicaltrials.gov and Google Scholar databases were systematically searched from inception. All observational studies reporting serum adipokine values among preeclamptic and healthy pregnant women were held eligible.

RESULTS

A total of 163 studies were included, comprising 23,482 women. Leptin was evaluated in 91 studies and its values were found to be significantly elevated in preeclamptic women during all pregnancy trimester, independently of disease onset and severity. Preeclampsia was also associated with increased serum fatty acid binding protein-4 and chemerin levels, when measured both during the 1st and 3rd trimester. Data concerning the rest adipokines were either conflicting or limited to reach firm conclusions. Quality of evidence was evaluated to be high for leptin, moderate for serum fatty acid binding protein-4 and chemerin and low for the other adipokines.

CONCLUSIONS

The existing evidence suggests that preeclampsia is linked to increased levels of leptin, chemerin and fatty acid binding protein-4 in all pregnancy trimesters and forms of the disease. Inconsistent data currently exists concerning the role of the other adipokines. Large-scale prospective studies should longitudinally evaluate the serum concentration of novel adipokines and define the optimal threshold and timing of measurement to be widely applied in clinical practice.

From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.

Maternal dietary fatty acids and their roles in human placental development

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

Declined placental PLAC1 expression is involved in preeclampsia

BACKGROUND

This study aimed to clarify the change of the expression of placenta-specific 1 (PLAC1) in the placenta of preeclamptic women and to explore the regulatory effects on thophoblast by PLAC1.

METHODS

Nineteen women with preeclampsia and 19 with normal pregnancies were recruited, and then we determined the expression of PLAC1 by immunohistochemistry (IHC) and Western blotting. To observe the effect of hypoxia on the expression of PLAC1, trophoblasts were cultured at the normoxia or hypoxia condition. Small interference of ribonucleic acid (siRNA) was used to silence PLAC1. The proliferation, migration and invasion of trophoblasts were evaluated with cell counting kit-8 and transwell analysis, and the apoptosis of trophoblast was evaluated by flow cytometry with FITC and PI staining.

RESULTS

Placental PLAC1 expression was significantly decreased in severe preeclampsia compared with control (P < .001). The expression of PLAC1 in trophoblasts was significantly decreased after treated with low oxygen concentration (P = .018). PLAC1 siRNA significantly inhibited the proliferation (P < .001), the migration (P < .001) and invasion (P < .001) of trophoblasts, but increased the apoptosis (P = .004 for Swan-71; P = .031 for Jar).

CONCLUSIONS

The expression of PLAC1 was declined in preeclampsia and this inhibited the function of trophoblast, suggesting PLAC1 may play a role in the development of preeclampsia.

Increased plasma fatty acid binding protein 4 concentration at the first prenatal visit and its relevance to preeclampsia

Preeclampsia affects 2-8% of all pregnancies, and it is associated with significant perinatal mortality and morbidities including preterm birth and small for gestational age. We examined whether plasma fatty acid binding protein 4 (FABP4) concentrations are associated with risk of later preeclampsia development. From March 2015 to May 2016, serum FABP4 was measured in 1486 women in early pregnancy. The relationship between the levels of FABP4 and preeclampsia were evaluated using univariate and multivariate regression analysis. The median plasma concentration of FABP4 at the first prenatal visit was significantly higher in women in whom preeclampsia developed later compared with those in whom it did not (P < 0.001). For each 1 unit increase in FABP4 plasma concentration, the unadjusted and adjusted risk of preeclampsia increased by 8% (odds ratio (OR): 1.08; 95% confidence interval [CI]: 1.05-1.12) and 4% (1.04; 95% CI: 1.02-1.07), respectively. The addition of FABP4 to established risk factors significantly improved net reclassification improvement. Increased FABP4 at the first prenatal visit of gestation independently predicted preeclampsia and significantly improved reclassification and discrimination. This information is important to guide public health efforts in preeclampsia prevention.