Placental tissue cyclo-oxygenase 1 and 2 in pre-eclamptic and normal pregnancy

Global Transcriptomic Analysis of Placentas from Women with Gestational SARS-CoV-2 Infection during the Third Trimester of Pregnancy

The COVID-19 pandemic has had a significant and enduring influence on global health, including maternal and fetal well-being. Evidence suggests that placental dysfunction is a potential consequence of SARS-CoV-2 infection during pregnancy, which may result in adverse outcomes such as preeclampsia and preterm birth. However, the molecular mechanisms underlying this association remain unclear, and it is uncertain whether a mature placenta can protect the fetus from SARS-CoV-2 infection. To address the above gap, we conducted a transcriptome-based study of the placenta in both maternal and fetal compartments. We collected placental samples from 16 women immediately after term delivery, seven of which had SARS-CoV-2 infection confirmed by PCR before parturition. Notably, we did not detect any viral load in either the maternal or fetal compartments of the placenta, regardless of symptomatic status. We separately extracted total RNA from placental tissues from maternal and fetal compartments, constructed cDNA libraries, and sequenced them to assess mRNA. Our analysis revealed 635 differentially expressed genes when a false discovery rate (FDR ≤ 0.05) was applied in the maternal placental tissue, with 518 upregulated and 117 downregulated genes in the SARS-CoV-2-positive women (n = 6) compared with the healthy SARS-CoV-2-negative women (n = 8). In contrast, the fetal compartment did not exhibit any significant changes in gene expression with SARS-CoV-2 infection. We observed a significant downregulation of nine genes belonging to the pregnancy-specific glycoprotein related to the immunoglobulin superfamily in the maternal compartment with active SARS-CoV-2 infection (fold change range from -13.70 to -5.28; FDR ≤ 0.01). Additionally, comparing symptomatic women with healthy women, we identified 1788 DEGs. Furthermore, a signaling pathway enrichment analysis revealed that pathways related to oxidative phosphorylation, insulin secretion, cortisol synthesis, estrogen signaling, oxytocin signaling, antigen processing, and presentation were altered significantly in symptomatic women. Overall, our study sheds light on the molecular mechanisms underlying the reported clinical risks of preeclampsia and preterm delivery in women with SARS-CoV-2 infection. Nonetheless, studies with larger sample sizes are warranted to further deepen our understanding of the molecular mechanisms of the placenta's anti-viral effects in maternal SARS-CoV-2 infection.

Evaluation of oxidative stress markers in subtypes of preeclampsia: A systematic review and meta-analysis

Studies about oxidative stress biomarkers revealed different phenotypes between early and late preeclampsia (PE). Despite that, there is extensive evidence of oxidative stress in investigations that combinate forms different of preeclampsia. This study reviews the oxidative stress profile in the PE subtypes and evaluates which markers are altered in the blood and placental tissue. A search was conducted in databases such as MEDLINE, EMBASE, LILACS, and Web of Science without restricting the year and language of publication. The quality of the studies was evaluated by the Newcastle-Ottawa scale and Joanna Briggs Institute for analytical Cross-Sectional Studies. After 13,319 screened records, 65 were included in the systematic review. The markers of stress oxidative of damage and reactive species were those selected, such as malondialdehyde (MDA), lipid peroxide, advanced protein oxidation products, carbonyl protein, 8-hydroxy-2'-deoxyguanosine, total oxidant status, hydrogen peroxide, nitric oxide (NO). We described the antioxidant activity, including the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase, free glutathione, and total antioxidant capacity (TAC). We results demonstrated that oxidative stress is related to pathophysiology of PE, there were increased lipid peroxidation in the blood and placenta, and in blood a reduction of NO levels and of TAC, like lower enzymatic activity of GPx, CAT in PE, and SOD in mild PE. In addition, altered levels of MDA in the placenta and blood show that placental changes have repercussions on the clinical syndrome and are related to the severity of the disease.

Uteroplacental Circulation in Normal Pregnancy and Preeclampsia: Functional Adaptation and Maladaptation

Uteroplacental blood flow increases as pregnancy advances. Adequate supply of nutrients and oxygen carried by uteroplacental blood flow is essential for the well-being of the mother and growth/development of the fetus. The uteroplacental hemodynamic change is accomplished primarily through uterine vascular adaptation, involving hormonal regulation of myogenic tone, vasoreactivity, release of vasoactive factors and others, in addition to the remodeling of spiral arteries. In preeclampsia, hormonal and angiogenic imbalance, proinflammatory cytokines and autoantibodies cause dysfunction of both endothelium and vascular smooth muscle cells of the uteroplacental vasculature. Consequently, the vascular dysfunction leads to increased vascular resistance and reduced blood flow in the uteroplacental circulation. In this article, the (mal)adaptation of uteroplacental vascular function in normal pregnancy and preeclampsia and underlying mechanisms are reviewed.

Molecular Changes on Maternal-Fetal Interface in Placental Abruption-A Systematic Review

Placental abruption is the separation of the placenta from the lining of the uterus before childbirth. It is an infrequent perinatal complication with serious after-effects and a marked risk of maternal and fetal mortality. Despite the fact that numerous placental abruption risk factors are known, the pathophysiology of this issue is multifactorial and not entirely clear. The aim of this review was to examine the current state of knowledge concerning the molecular changes on the maternal–fetal interface occurring in placental abruption. Only original research articles describing studies published in English until the 15 March 2021 were considered eligible. Reviews, book chapters, case studies, conference papers and opinions were excluded. The systematic literature search of PubMed/MEDLINE and Scopus databases identified 708 articles, 22 of which were analyzed. The available evidence indicates that the disruption of the immunological processes on the maternal–fetal interface plays a crucial role in the pathophysiology of placental abruption. The features of chronic non-infectious inflammation and augmented immunological cytotoxic response were found to be present in placental abruption samples in the reviewed studies. Various molecules participate in this process, with only a few being examined. More advanced research is needed to fully explain this complicated process.

Maternal vitamin D deficiency influences long-chain polyunsaturated fatty acids and pregnancy outcome in association with alterations in one-carbon metabolism

Preeclampsia is a pregnancy-specific disorder, leading to maternal and infant morbidity and mortality. Abnormal placentation has been reported in preeclampsia. Nutrients like vitamin D and long-chain polyunsaturated fatty acids (LCPUFA) are known to play a role in placental development. In an animal model, we have previously demonstrated that maternal vitamin D deficiency increases the thromboxane/prostacyclin ratio and contributes to inflammation and vasoconstriction. We hypothesize that maternal vitamin D status influences placental LCPUFA metabolism through alterations in one carbon metabolism in women with preeclampsia. To test this hypothesis, we recruited 69 normotensive control (NC) women and 50 women with preeclampsia. Women with preeclampsia had lower placental protein and mRNA levels of cystathionine-β-synthase (CBS), higher plasma malondialdehyde (MDA) levels and higher levels of arachidonic acid (AA) and total omega-6 fatty acids in the placenta. Women with preeclampsia also demonstrated higher placental mRNA levels of cyclooxygenase-2 (COX-2) as compared to NC women. Maternal 25(OH)D levels were negatively associated with maternal plasma MDA levels. Placental vitamin D receptor (VDR) levels were positively associated with CBS while maternal MDA levels were positively associated with serum levels of thromboxane-B2 (TXB2) levels. Our findings indicate that vitamin D deficiency increases oxidative stress through alterations in one carbon metabolism to influence pro-inflammatory omega-6 metabolic pathway in the placenta. This study demonstrates a possible mechanism through which vitamin D deficiency can result in an imbalance in the LCPUFA metabolites and contribute to placental inflammation and endothelial dysfunction in preeclampsia.

Serum protein marker panel for predicting preeclampsia

BACKGROUND

Preeclampsia is a multi-system disorder in pregnancy which has no effective treatment. The diagnosis of preeclampsia is based on clinical presentation and routine laboratory tests.

OBJECTIVE

This study aimed at identifying serum protein markers for diagnosis of preeclampsia and predicting its severe features.

STUDY DESIGN

In total, 172 pregnant women were enrolled in this study including 110 subjects with preeclampsia and 62 normotensive subjects. Eleven serum proteins (VEGF, sFlt-1, sEndoglin, PlGF, sEGFR, prolactin, PTX3, PAI-1, NGAL, IL-27, COX-2) were assessed using Luminex multiplex immunoassay and ELISA.

RESULTS

The levels of seven proteins (sFlt-1, VEGF, sEndoglin, sEGFR, PlGF, NGAL, COX-2) correlated with preeclampsia, and 4 proteins (VEGF, sEndoglin, PlGF, sEGFR) were identified as independent factors associated with preeclampsia. The levels of three proteins (sEndoglin, PTX3, sFlt-1) correlated with severe features of preeclampsia, and three variables (serum creatinine, platelet count and sEndoglin) were identified as independent factors in predicting severe features of preeclampsia.

CONCLUSIONS

A combination of serum protein markers (VEGF, sEndoglin, PlGF, sEGFR) and clinical variables (serum creatinine, platelet count and sEndoglin) could be used as analytical tool in diagnosis of preeclampsia and its severe features, respectively. Serum sEGFR, a novel biomarker in preeclampsia, may be involved in the pathogenesis of preeclampsia.

Expression levels of cyclooxygenase-2, tumor necrosis factor-α and inducible NO synthase in placental tissue of normal and preeclamptic pregnancies

OBJECTIVE

Although preeclampsia (PE) is one of the most important problems affecting pregnant women, etiologic factors in its development are still unclear. We aimed to investigate the expression levels of cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α) and inducible NO synthase (iNOS) in preeclamptic and healthy control placentas.

PATIENTS AND METHODS

Placental tissue samples were obtained after delivery from patients diagnosed with PE and from normal-term pregnants and analyzed for COX-2, TNF-α and iNOS expression by immunohistochemistry.

RESULTS

A strong expression of COX-2 was observed in syncytiotrophoblast cells of preeclamptic placentas, which was significantly higher than that of normal placentas (p = 0.005). A mild expression of TNF-α in both normal and preeclamptic syncytiotrophoblasts was seen (p = 0.435). In addition, a strong expression of iNOS in normal syncytiotrophoblasts was found, but the intensity of the iNOS expression was highly reduced in preeclamptic placentas (p = 0.001). No correlation was detected between COX-2, TNF-α and iNOS expression levels.

CONCLUSION

The findings of a decrease of iNOS expression and an increase of COX-2 expression in placenta suggest the existence of functional roles of iNOS and COX-2 in the pathophysiology of PE, probably by contributing to the reduced placental blood flow and increased resistance to flow in the fetomaternal circulation.

Examination of the expression of cyclooxygenase-2 in placenta villi from sufferers of pregnancy induced hypertension

OBJECTIVES

The purpose of this paper is to elucidate the roles of phospholipase A(2) (PLA(2)), cyclooxygenase-2 (COX-2), and prostaglandin I(2) (PGI(2)) synthase in pregnancy induced hypertension (PIH).

METHODS

In placentas from normal pregnant women and pregnant women with severe PIH, the enzyme expression of PLA(2), COX-2, and PGI(2) synthase was measured using real time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The expression of each enzyme was compared between normal (n=12) and PIH (n=12) groups. The expression levels of COX-2 and PGI(2) synthase during PIH pregnancy were significantly decreased to about 51% and 68%, respectively, of their values in normal pregnancy. However, the expression of PLA(2) was hardly changed by PIH.

CONCLUSIONS

The decreases in COX-2 and PGI(2) synthase expression in severe PIH placentas may be causal factors in the disruption of the PGI(2)-thromboxane A(2) (TXA(2)) balance in favor of TXA(2). The decrease in COX-2 was more marked than that of PGI(2) synthase.

Changes in the metabolic footprint of placental explant-conditioned culture medium identifies metabolic disturbances related to hypoxia and pre-eclampsia

Pre-eclampsia (PE) is a multi-system disorder thought to be mediated by circulating factors released from damaged placental villous trophoblast. There is extensive evidence of changes in the villous tissue in PE, some of which may be replicated by culturing villous tissue in hypoxic conditions. Metabolic footprinting offers a hypothesis-generating strategy to investigate factors released from this tissue in vitro. This study investigated differences in the factors released from villous trophoblast from uncomplicated pregnancies (n=6) and those with PE (n=6). In both cases, explanted placental villous fragments were cultured for 96 h in 1% O(2) (hypoxia) or 6% O(2) (placental normoxia). Metabolites consumed from and released into serum-conditioned culture medium were analysed by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS). The relative concentration of 154 features of the metabolic footprint were observed to change in culture medium from uncomplicated pregnancies cultured in normoxic and hypoxic conditions (p<0.00005). 21 and 80 features were also different in culture medium from PE versus uncomplicated pregnancies cultured in hypoxic and normoxic conditions, respectively (p<0.00005). When comparing all 4 groups, 47 metabolic features showed a similar relative concentration in PE-derived media cultured in normoxic conditions to conditioned media from normal villous tissue cultured in hypoxic conditions. These data suggest that hypoxia may have a role in the placental pathogenesis of PE. Three areas of metabolism were highlighted for systems biology investigation; glutamate and glutamine, tryptophan metabolism and leukotriene or prostaglandin metabolism.

Second trimester hepatic rupture in a 35 year old nulliparous woman with HELLP syndrome: a case report

The HELLP syndrome (haemolysis, elevated liver blood tests and low platelets) is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10–20% of cases with severe preeclampsia. Hepatic capsular rupture is a rare yet dramatic complication of HELLP syndrome. The majority of cases occur in multiparous women over the age of 30. Classically it presents with acute onset right upper quadrant pain in the presence of constitutional symptoms such as vomiting and pyrexia. However, symptoms and signs are usually non specific. Spontaneous hepatic rupture can be preceded by signs of hypovolaemic shock; yet the diagnosis is infrequently made prior to emergent laparotomy. We present the case of a 35 year old nulliparous woman with a second trimester gestational hepatic rupture associated with HELLP syndrome. We briefly discuss the aetiology, diagnostic difficulties and treatment options associated with this rare presentation.