2-methoxyestradiol plasma levels are associated with clinical severity indices and biomarkers of preeclampsia

Lipidomics and plasma hormone analysis differentiate reproductive and pregnancy statuses in Florida manatees (Trichechus manatus latirostris)

Florida manatees (Trichechus manatus latirostris) are protected as a threatened species, and data are lacking regarding their reproductive physiology. This study aimed to (1) quantify plasma steroid hormones in Florida manatees from two field sites, Crystal River and Indian River Lagoon, at different gestational stages and to (2) identify individual lipids associated with pregnancy status. Ultra-high performance liquid chromatography-tandem mass spectrometric analysis was used to measure plasma steroid hormones and lipids. Pregnant female manatees were morphometrically distinct from male and non-pregnant female manatees, characterized by larger body weight and maximal girth. Progesterone concentrations in manatees were also elevated during early gestation versus late gestation. Cholesterol, an important metabolic lipid, and precursor for reproductive steroids, was not different between groups. Mass spectrometry quantified 949 lipids. Plasma concentrations of glycerophospholipids, glycerolipids, sphingolipids, acylcarnitines, and cholesteryl esters were associated with pregnancy status in the Florida manatee. Most of the lipid species associated with pregnancy were triacylglycerides, phosphatidylethanolamines, and ether-linked phosphatidylethanolamines, which may serve as energy sources for fetal development. This research contributes to improving knowledge of manatee reproductive physiology by providing data on plasma steroid hormones relative to reproductive status and by identifying plasma lipids that may be important for pregnancy. Elucidation of lipid species directly associated with pregnancy has the potential to serve as a diagnostic approach to identify pregnant individuals in fresh and archived samples. These biochemical and morphometric indicators of reproductive status advance the understanding of manatee physiology.

Pregnancy by Oocyte Donation: Reviewing Fetal-Maternal Risks and Complications

Oocyte donation (OD) has greatly improved over the last three decades, becoming a preferred practice of assisted reproductive technology (ART) for infertile women wishing for motherhood. Through OD, indeed, it has become possible to overcome the physiological limitation due to the ovarian reserve (OR) exhaustion as well as the poor gamete reliability which parallels the increasing age of women. However, despite the great scientific contribution related to the success of OD in the field of infertility, this practice seems to be associated with a higher rate of major risky events during pregnancy as recurrent miscarriage, infections and placental diseases including gestational hypertension, pre-eclampsia and post-partum hemorrhage, as well as several maternal-fetal complications due to gametes manipulation and immune system interaction. Here, we will revisit this questioned topic since a number of studies in the medical literature focus on the successful aspects of the OD procedure in terms of pregnancy rate without, however, neglecting the risks and complications potentially linked to external manipulation or heterologous implantation.

Sex differences in placenta-derived markers and later autistic traits in children

Autism is more prevalent in males and males on average score higher on measures of autistic traits. Placental function is affected significantly by the sex of the fetus. It is unclear if sex differences in placental function are associated with sex differences in the occurrence of autistic traits postnatally. To assess this, concentrations of angiogenesis-related markers, placental growth factor (PlGF) and soluble fms-like tyrosine kinase (sFlt-1) were assessed in maternal plasma of expectant women in the late 1^st (mean= 13.5 [SD = 2.0] weeks gestation) and 2^nd trimesters (mean=20.6 [SD = 1.2] weeks gestation), as part of the Generation R Study, Rotterdam, the Netherlands. Subsequent assessment of autistic traits in the offspring at age 6 was performed with the 18-item version of the Social Responsiveness Scale (SRS). Associations of placental protein concentrations with autistic traits were tested in sex-stratified and cohort-wide regression models. Cases with pregnancy complications or a later autism diagnosis (n = 64) were also assessed for differences in placenta-derived markers. sFlt-1 levels were significantly lower in males in both trimesters but showed no association with autistic traits. PlGF was significantly lower in male pregnancies in the 1^st trimester, and significantly higher in the 2^nd trimester, compared to female pregnancies. Higher PlGF levels in the 2^nd trimester and the rate of PlGF increase were both associated with the occurrence of higher autistic traits (PlGF-2^nd: n = 3469,b = 0.24 [SE = 0.11], p = 0.03) in both unadjusted and adjusted linear regression models that controlled for age, sex, placental weight and maternal characteristics. Mediation analyses showed that higher autistic traits in males compared to females were partly explained by higher PlGF or a faster rate of PlGF increase in the second trimester (PlGF-2^nd: n = 3469, ACME: b = 0.005, [SE = 0.002], p = 0.004). In conclusion, higher PlGF levels in the 2^nd trimester and a higher rate of PlGF increase are associated with both being male, and with a higher number of autistic traits in the general population.

Factors Involved in Endothelial Dysfunction Related to Angiogenic Disbalance and Oxidative Stress, in Women at High Risk of Term Pre-Eclampsia

Oxidative and inflammatory stress, angiogenic imbalance, and endothelial dysfunction are pathophysiological mechanisms occurring in pre-eclampsia (PE) that may persist over time and predispose women to a higher risk of cardiovascular disease (CVD) in the future. However, there is little evidence on the vascular function of women at risk of PE who have not developed the disease. The main objective of this research is to study factors and biomarkers involved in endothelial dysfunction related to oxidative stress, angiogenic disbalance, and inflammation in women at high risk of term PE who do not develop the disease. An observational, analytical, retrospective, and descriptive study was carried out in a selected sample of 68 high-risk and 57 non-risk of term PE participants in the STATIN study (FFIS/2016/02/ST EUDRACT No: 2016-005206-19). A significant increase in mean arterial pressure (MAP) levels and oxidative stress biomarkers (uric acid, homocysteine, and total serum antioxidant capacity) was found. Biomarkers of inflammation (interleukin-6 and growth differentiation factor 15) and endothelial function (asymmetric dimethylarginine) were significantly elevated in the group at risk of pre-eclampsia. A significative dependence relationship was also established between MAP and interleukin-6 and uric acid. These results suggest that women at high risk of term PE may represent pregnancies with pre-existing maternal risk factors for CVD, manifested by the own cardiovascular overload of pregnancy. A better understanding of maternal cardiovascular function in pregnancy would allow the improved prediction of CVD late in life in women.

Secretory products of the corpus luteum and preeclampsia

BACKGROUND

Despite significant advances in our understanding of the pathophysiology of preeclampsia (PE), there are still many unknowns and controversies in the field. Women undergoing frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium have been found to have an unexpected increased risk of PE compared to women who receive embryos in a natural FET cycle. The differences in risk have been hypothesized to be related to the absence or presence of a functioning corpus luteum (CL).

OBJECTIVE AND RATIONALE

To evaluate the literature on secretory products of the CL that could be essential for a healthy pregnancy and could reduce the risk of PE in the setting of FET.

SEARCH METHODS

For this review, pertinent studies were searched in PubMed/Medline (updated June 2020) using common keywords applied in the field of assisted reproductive technologies, CL physiology and preeclampsia. We also screened the complete list of references in recent publications in English (both animal and human studies) on the topics investigated. Given the design of this work as a narrative review, no formal criteria for study selection or appraisal were utilized.

OUTCOMES

The CL is a major source of multiple factors regulating reproduction. Progesterone, estradiol, relaxin and vasoactive and angiogenic substances produced by the CL have important roles in regulating its functional lifespan and are also secreted into the circulation to act remotely during early stages of pregnancy. Beyond the known actions of progesterone and estradiol on the uterus in early pregnancy, their metabolites have angiogenic properties that may optimize implantation and placentation. Serum levels of relaxin are almost undetectable in pregnant women without a CL, which precludes some maternal cardiovascular and renal adaptations to early pregnancy. We suggest that an imbalance in steroid hormones and their metabolites and polypeptides influencing early physiologic processes such as decidualization, implantation, angiogenesis and maternal haemodynamics could contribute to the increased PE risk among women undergoing programmed FET cycles.

WIDER IMPLICATIONS

A better understanding of the critical roles of the secretory products of the CL during early pregnancy holds the promise of improving the efficacy and safety of ART based on programmed FET cycles.

Estrogen and Preeclampsia: Potential of Estrogens as Therapeutic Agents in Preeclampsia

There is a significant decline in the estrogen levels in preeclampsia, and exogenous administration of estradiol normalizes blood pressure and other associated symptoms of preeclampsia. The decrease in estrogen levels may be due to changes in enzyme activities of hydroxysteroid (17-β) dehydrogenase 1, aromatase, and COMT. There is also a decrease in the novel, estrogenic G-protein-coupled receptor 30 (GPR30) in the placental trophoblast cells in preeclampsia. The activation of GPR30 protects the placenta from hypoxia-reoxygenation injury, decreases apoptosis and increases proliferation through eNOS and PI3K-Akt signaling pathways. Estrogens may also increase Ca²⁺-activated K⁺ channel function, decrease the release of inflammatory cytokines, and oxidative stress to improve placental perfusion. Both preclinical and clinical studies show the decrease in the 2-methoxyestradiol levels in preeclampsia, which may be due to a decrease in estradiol itself along with a decrease in the enzymatic actions of the COMT enzyme. 2-Methoxyestradiol activates HIF1α and vascular endothelial growth factor receptors (VEGFR-2) to maintain placental perfusion by increasing angiogenesis. The present review discusses the preclinical and clinical studies describing the role of estrogen in preeclampsia along with possible mechanisms.

Loss of placental growth factor ameliorates maternal hypertension and preeclampsia in mice

Preeclampsia remains a clinical challenge due to its poorly understood pathogenesis. A prevailing notion is that increased placental production of soluble fms-like tyrosine kinase-1 (sFlt-1) causes the maternal syndrome by inhibiting proangiogenic placental growth factor (PlGF) and VEGF. However, the significance of PlGF suppression in preeclampsia is uncertain. To test whether preeclampsia results from the imbalance of angiogenic factors reflected by an abnormal sFlt-1/PlGF ratio, we studied PlGF KO (Pgf-/-) mice and noted that the mice did not develop signs or sequelae of preeclampsia despite a marked elevation in circulating sFLT-1. Notably, PlGF KO mice had morphologically distinct placentas, showing an accumulation of junctional zone glycogen. We next considered the role of placental PlGF in an established model of preeclampsia (pregnant catechol-O-methyltransferase-deficient [COMT-deficient] mice) by generating mice with deletions in both the Pgf and Comt genes. Deletion of placental PlGF in the context of COMT loss resulted in a reduction in maternal blood pressure and increased placental glycogen, indicating that loss of PlGF might be protective against the development of preeclampsia. These results identify a role for PlGF in placental development and support a complex model for the pathogenesis of preeclampsia beyond an angiogenic factor imbalance.

Association of 2-Methoxyestradiol (2ME) Plasma Levels with Clinical Severity Indices and Biomarkers of Preeclampsia

Introduction

Preeclampsia is an important cause of maternal and perinatal morbidity and mortality. The pathophysiology of preeclampsia has been extensively studied. 2ME seems to maintain placental homeostasis necessary for appropriate cytotrophoblast invasion of the maternal deciduas. We plan this study to compare its value in the plasma of normotensive and preeclamptic women and studying its correlation with the severity indices of preeclampsia.

Aim and Objectives

The aim of this study was to estimate plasma levels of 2ME in preeclamptic and normotensive pregnant women and correlate it with the severity in terms of clinical indices, laboratory investigations, and fetomaternal outcome.

Materials and Methods

This study was a case-control study conducted in KGMU, Lucknow, August 2015-2016. Sample size was 90 pregnant women including 30 normotensive, 30 non-severe preeclampsia, and 30 severe preeclampsia patients. Plasma 2ME levels were analyzed using ELISA kit and the outcome was compared in terms of systolic and diastolic blood pressure, proteinuria, liver and renal function tests, serum LDH, uric acid, plasma 2ME levels, and fetomaternal outcome.

Results

There was a significant (p = 0.0001) difference in 2ME plasma levels among the groups (normotensive, non severe and severe preeclampsia patients). 2ME plasma levels significantly negatively correlated with SBP (r = - 0.62, p = 0.0001) and DBP (r = - 0.63, p = 0.0001). With one-unit increase in SBP, 2ME will decrease by 2445.14 units, and in one-unit increase in DBP, 2ME will decrease by 1807.28 units. The sensitivity and specificity of 2ME for preeclampsia were found to be high.

Conclusion

It was seen that there was a statistically significant difference between plasma 2ME levels among the three groups. The ROC curve obtained showed that sensitivity was predicted to be 98.3%, specificity 76.7%, positive predictive value of 89.4%, negative predictive value of 95.8% and accuracy of 91.1%.

2-Methoxyestradiol causes matrix metalloproteinase 9-mediated transactivation of epidermal growth factor receptor and angiotensin type 1 receptor downregulation in rat aortic smooth muscle cells

Studies have demonstrated the therapeutic potential of estrogen metabolite 2-methoxyestradiol (2ME2) in several cardiovascular disorders, including hypertension. However, the exact mechanism(s) remains unknown. In this study, primary rat aortic smooth muscle cells (RASMCs) were exposed to 2ME2, and angiotensin type 1 receptor (AT1R) expression, function, and associated signaling pathways were evaluated. In RASMCs, 2ME2 downregulated AT1R expression in a concentration- and time-dependent manner, which was correlated with reduced mRNA expression. The 2ME2 effect was through G protein-coupled receptor 30 (GPR30) that inhibits second messenger cAMP. Moreover, 2ME2 exposure phosphorylated ERK1/2 that was sensitive to MEK inhibitor PD98059. Selective epidermal growth factor receptor (EGFR) inhibitor AG1478 blocked 2ME2-induced EGFR transactivation and attenuated subsequent phosphorylation of ERK1/2 preventing AT1R downregulation. The transactivation was dependent on 2ME2-induced release of matrix metalloproteinase 9 (MMP9) and epidermal growth factor demonstrated by ELISA. Furthermore, transfection with small interfering (si) RNA targeting MMP9 impeded ERK1/2 activation and AT1R downregulation in response to 2ME2 and G1 stimulation. Interestingly, under similar conditions, stimulation of GPR30 with the selective agonist G1 elicited similar signaling pathways and downregulated the AT1R expression that was reversed by GPR30 antagonist G15. Furthermore, 2ME2 and G1 inhibited angiotensin II (ANG II) induced Ca2+ release, a response consistent with AT1R downregulation. Collectively, our study demonstrates for the first time that 2ME2 binding to GPR30 induces MMP9 specific transactivation of EGFR that mediates ERK1/2-dependent downregulation of AT1R in RASMCs. The study provides critical insights into the newly discovered role and signaling pathways of 2ME2 in the regulation of AT1R in vascular cells and its potential to be developed as a therapeutic agent that ameliorates hypertension.

Lipidomics in translational research and the clinical significance of lipid-based biomarkers

Lipidomics is a rapidly developing field of study that focuses on the identification and quantitation of various lipid species in the lipidome. Lipidomics has now emerged in the forefront of scientific research due to the importance of lipids in metabolism, cancer, and disease. Using both targeted and untargeted mass spectrometry as a tool for analysis, progress in the field has rapidly progressed in the last decade. Having the ability to assess these small molecules in vivo has led to better understanding of several lipid-driven mechanisms and the identification of lipid-based biomarkers in neurodegenerative disease, cancer, sepsis, wound healing, and pre-eclampsia. Biomarker identification and mechanistic understanding of specific lipid pathways linked to a disease's pathologies can form the foundation in the development of novel therapeutics in hopes of curing human disease.

Fetal Val108/158Met catechol-O-methyltransferase (COMT) polymorphism and placental COMT activity are associated with the development of preeclampsia

OBJECTIVE

To evaluate the association between fetal and maternal catechol-O-methyltransferase (COMT) Val158Met and methyl tetrahydrofolate reductase (MTHFR) C677T functional polymorphisms and preeclampsia, examining its influence on placental COMT and in maternal 2-methoxyestradiol (2-ME) plasma levels.

DESIGN

Prospective case-control study.

SETTING

University hospital.

PATIENT(S)

A total of 53 preeclamptic and 72 normal pregnant women.

INTERVENTION(S)

Maternal and cord blood samples and placental tissue samples were obtained.

MAIN OUTCOME MEASURE(S)

Maternal and fetal COMT and MTHFR polymorphisms were genotyped. Maternal plasma 2-ME and homocysteine levels, and expression and activity of placental COMT were measured.

RESULT(S)

The odds ratio for the risk of preeclampsia for fetal COMT Met/Met was 3.22, and it increased to 8.65 when associated with fetal MTHFR TT. Placental COMT activity and expression were influenced by genotype, but COMT activity in preeclamptic placentas did not differ from control pregnancies. There was no association between any genotypes and maternal 2-ME. Homocysteine levels were higher in women with preeclampsia than in normal pregnancies, and were inversely correlated with 2-ME plasma levels, indicating that its altered metabolism may lower COMT activity in vivo.

CONCLUSION(S)

Fetal Met-Met COMT genotype reduces COMT placental expression and activity in vitro and increases preeclampsia, risk but it does not explain the difference in maternal 2-ME levels between preeclamptic and normal pregnancies. However, the preeclamptic patients had elevated homocysteine levels that correlated inversely with 2-ME, indicating that an altered methionine-homocysteine metabolism may contribute to reduce COMT activity in vivo and explain the decreased levels of 2-ME in preeclamptic women.