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A blood test done in early pregnancy that measures cell-free DNA methylation could represent a novel way to predict the risk of preterm pre-eclampsia.

The genetic deletion of apelin receptor early endogenous ligand (Elabela; official name APELA) produces a preeclampsia-like phenotype in mice. However, evidence linking ELABELA with human disease is lacking. Therefore, we measured placental mRNA and circulating ELABELA in human samples. ELABELA mRNA (measured by RNA sequencing) was unchanged in 82 preeclamptic placentas compared with 82 matched controls (mean difference, 0.53%; 95% CI, −25.9 to 27.0; P = 0.78). We measured circulating ELABELA in 32 women with preterm preeclampsia (delivered at <34 weeks' gestation) and 32 matched controls sampled at the same gestational age. There was no difference in circulating ELABELA concentrations in the preeclamptic cohort compared with controls (median, 28.5 pg/mL; 95% CI, 5.3 to 63.2 versus median, 20.5 pg/mL; 95% CI, 9.2 to 58.0, respectively); the median difference was 8.0 pg/mL (95% CI, −17.7 to 12.1; P = 0.43). In contrast, soluble FLT1(a protein with an established association with preeclampsia) mRNA was increased in placental tissue (mean difference, 34.9%; 95% CI, 16.6 to 53.1; P = 0.001), and circulating concentrations were 16.8-fold higher among the preeclamptic cohort (P < 0.0001). In conclusion, we were able to recapitulate the association between circulating soluble FLT1 and preeclampsia, but there was no association with ELABELA. The speculated clinical relevance of observations in the murine model linking ELABELA to preeclampsia likely are incorrect.

Background:Preeclampsia is a severe complication of pregnancy. Chemerin is an adipokine secreted from adipose tissue and highly expressed in placenta. This study evaluated the biomarker potential of circulating chemerin to predict preeclampsia.Methods:Maternal plasma and placenta were collected from women with early-onset preeclampsia (<34 weeks), with preeclampsia and eclampsia, or before preeclampsia diagnosis (36 weeks). Human trophoblast stem cells were differentiated into syncytiotrophoblast or extravillous trophoblasts across 96 hours. Cells were cultured in 1% O2(hypoxia) or 5% O2(normoxia). Chemerin was measured by enzyme-linked immunosorbent assay (ELISA) and RARRES2(gene coding chemerin) by reverse transcription-quantitative polymerase chain reaction.Results:Circulating chemerin was increased in 46 women with early-onset preeclampsia (<34 weeks) compared to 17 controls (P< .0006). Chemerin was increased in placenta from 43 women with early-onset preeclampsia compared to 24 controls (P< .0001). RARRES2was reduced in placenta from 43 women with early-onset preeclampsia vs 24 controls (P< .0001).Chemerin was increased in plasma from 26 women with established preeclampsia (P= .006), vs 15 controls. Circulating chemerin was increased in 23 women who later developed preeclampsia vs 182 who did not (P= 3.23 × 10−6).RARRES2was reduced in syncytiotrophoblast (P= .005) or extravillous trophoblasts (P< .0001). Hypoxia increased RARRES2expression in syncytiotrophoblast (P= .01) but not cytotrophoblast cells.Conclusions:Circulating chemerin was elevated in women with early-onset preeclampsia, established preeclampsia, and preceding preeclampsia diagnosis of preeclampsia. RARRES2was dysregulated in placenta complicated by preeclampsia and may be regulated through hypoxia. Chemerin may have potential as a biomarker for preeclampsia but would need to be combined with other biomarkers.

(Abstracted from BMJ2021;374:n2103)Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality, particularly when presenting preterm. Because the only treatment for preeclampsia is delivery, preterm preeclampsia often leads to preterm delivery placing the neonate at risk of major neonatal disability and death.

Context:Preeclampsia (PE), a pregnancy-specific disorder closely associated with endothelial dysfunction and capillary leakage, is responsible for substantial maternal/fetal morbidity and mortality. PE can be classified as early-onset (<34 wk) and late-onset (>34 wk); the two subsets differ in presentation and pathogenesis.Objectives:The objectives of the study were to examine serine protease high-temperature requirement factor A4 (HtrA4) expression in the placenta and other human tissues and in early-onset vs late-onset PE, to determine serum HtrA4 levels in normal pregnancy and in PE subtypes, and to investigate the effect of high levels of HtrA4 on endothelial integrity and function.Methods:Microarray data analysis and RT-PCR determined HtrA4 expression in the human placenta, various tissues, and cell lines. The serum HtrA4 protein levels were analyzed by an ELISA. The potential impact of excessive circulating HtrA4 on the maternal vasculature was determined by in vitro endothelial tube and permeability assays.Results:Human HtrA4 expression was restricted to the placenta and significantly up-regulated in early-onset but not late-onset PE. The serum HtrA4 levels in normal pregnancy increased significantly between the first and second trimesters and then remained constant. Women with early-onset but not late-onset PE showed significantly higher HtrA4 levels in serum compared with gestational age-matched controls. In cell models, high levels of HtrA4 disturbed endothelial cell tube formation and permeability in a dose-dependent manner, and this was linked to alterations in junctional proteins and microtubule organization.Conclusions:HtrA4 represents a novel placenta-specific serine protease that is altered specifically in early-onset PE with potential causal roles in endothelial dysfunction and disease development.

Soluble endoglin is an anti-angiogenic protein that is released from the placenta and contributes to both maternal endothelial dysfunction and the clinical features of severe preeclampsia. The mechanism through which soluble endoglin is released from the placenta is currently unknown; however, recent work in colorectal cancer identified matrix metalloproteinase 14 (MMP-14) as the cleavage protease of endoglin. To determine whether this is also the mechanism responsible for soluble endoglin release in preeclampsia, we investigated the expression of MMP-14 within the placenta and the effects of its inhibition on soluble endoglin release. Placentas were obtained from severe, early onset preeclamptic pregnancies (n= 8) and gestationally matched preterm controls (n= 8). MMP-14 was predominately localized to the syncytiotrophoblast. Results from a proximity ligation assay showed protein interactions between endogenous MMP-14 and endoglin within the preeclamptic placenta. To demonstrate that this interaction produces soluble endoglin, we treated trophoblastic BeWo cells with either a broad-spectrum MMP inhibitor (GM6001) or MMP-14 siRNA. Both treatments produced a decrease in soluble endoglin (P≤ 0.05). Treatment of mice bearing BeWo xenografts with GM6001 decreased circulating soluble endoglin levels in mouse serum (P≤ 0.05). These findings indicate that MMP-14 is the likely cleavage protease of endoglin in the setting of preeclampsia. This approach provides a novel method for the development of potential therapeutics to reduce circulating soluble endoglin and ameliorate the clinical features of severe preeclampsia.

Repairof the postmenstrual endometrium presents a unique opportunity to examine nonscarring repair in an adult tissue. We aimed to characterize and determine the importance of extracellular matrix (ECM) dynamics in cell migration during endometrial repair. Utilizing an in vivo mouse model of postmenstrual repair and an in vitro model of human endometrial re-epithelialization, we determined the dynamic changes in expression of ECM and related factors in both models by array analysis of repairing areas. We also validated expression of integrins, growth factors, protease inhibitors, basement membrane, and adhesion molecules in vitro and in both mouse and human repairing endometrium by quantitative RT-PCR and immunohistochemical studies. Finally, we determined the functional importance of integrin–fibronectin interactions and matrix metalloprotease (MMP)-facilitated cell movement during re-epithelialization and propose a model for cell locomotion during postmenstrual repair. These data demonstrated the dynamic expression and functional importance of ECM interactions in endometrial repair, which may be important for scar-free repair.

ObjectiveTo evaluate whether extended release metformin could be used to prolong gestation in women being expectantly managed for preterm pre-eclampsia.DesignRandomised, double blind, placebo controlled trial.SettingReferral hospital in Cape Town, South Africa.Participants180 women with preterm pre-eclampsia between 26+0 to 31+6 weeks’ gestation undergoing expectant management: 90 were randomised to extended release metformin and 90 to placebo.Intervention3 g of oral extended release metformin or placebo daily, in divided doses, until delivery.Main outcome measureThe primary outcome was prolongation of gestation.ResultsOf 180 participants, one woman delivered before taking any trial drug. The median time from randomisation to delivery was 17.7 days (interquartile range 5.4-29.4 days; n=89) in the metformin arm and 10.1 (3.7-24.1; n=90) days in the placebo arm, a median difference of 7.6 days (geometric mean ratio 1.39, 95% confidence interval 0.99 to 1.95; P=0.057). Among those who continued to take the trial drug at any dose, the median prolongation of gestation in the metformin arm was 17.5 (interquartile range 5.4-28.7; n=76) days compared with 7.9 (3.0-22.2; n=74) days in the placebo arm, a median difference of 9.6 days (geometric mean ratio 1.67, 95% confidence interval 1.16 to 2.42). Among those who took the full dosage, the median prolongation of gestation in the metformin arm was 16.3 (interquartile range 4.8-28.8; n=40) days compared with 4.8 (2.5-15.4; n=61) days in the placebo arm, a median difference of 11.5 days (geometric mean ratio 1.85, 95% confidence interval 1.14 to 2.88). Composite maternal, fetal, and neonatal outcomes and circulating concentrations of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin did not differ. In the metformin arm, birth weight increased non-significantly and length of stay decreased in the neonatal nursery. No serious adverse events related to trial drugs were observed, although diarrhoea was more common in the metformin arm.ConclusionsThis trial suggests that extended release metformin can prolong gestation in women with preterm pre-eclampsia, although further trials are needed. It provides proof of concept that treatment of preterm pre-eclampsia is possible.Trial registrationPan African Clinical Trial Registry PACTR201608001752102 https://pactr.samrc.ac.za/.

The article focuses on the study conducted regarding endometrial repair following menstrual cycle. It explained that menstrual bleeding is the shedding of the endometrium that takes place after failure of fertilization. The researchers were able to study this mechanism by inducing menstruation in mice. The study concludes that cessation of bleeding is the hallmark of complete endometrial repair and healing errors leads to bleeding problems which is suffered by women worldwide.

The anti-angiogenic protein, soluble fms-like tyrosine kinase-1 (sFLT-1), plays a central role in preeclamptic pathophysiology. A splice variant of FLT-1 (VEGF receptor 1), sFLT-1 is released in excessive amounts from the preeclamptic placenta into the maternal circulation, where it causes endothelial dysfunction manifesting as end-organ disease. However, the mechanisms regulating its production within the placenta remain poorly understood. Recently it was shown in endothelial cells that Jumonji domain containing protein 6 (JMJD6) hydroxylates U2 small nuclear ribonucleoprotein auxiliary factor 65-kDa subunit (U2AF65, a component of the splicesome). The hydroxylation by JMJD6 is oxygen dependent. Under hypoxia, JMJD6 is less able to hydroxylate U2AF65, and this unhydroxylated form of U2AF65 biases splicing of FLT-1 to sFLT-1. We assessed whether oxygen-sensing JMJD6 is differentially expressed in preeclamptic placenta and regulates sFLT-1 splicing in placenta via U2AF65. JMJD6 protein expression was significantly reduced in preterm preeclamptic placenta (P< 0.0001; n = 21) relative to preterm controls (n = 10). Exposing both placental and endothelial cells to hypoxia significantly reduced JMJD6 mRNA and increased sFLT-1 mRNA and protein expression. Silencing JMJD6 in primary endothelial and trophoblast cells significantly increased sFLT-1 secretion. Next, we examined whether these molecules may be directly interacting. We demonstrated that placental U2AF65 colocalized with JMJD6. In turn, we found JMJD6 directly interacts with U2AF65, which in turn produces sFLT-1 mRNA transcripts. Taken together, our findings provide evidence that JMJD6 may play a role in regulating the production of sFLT-1 in the preeclamptic placenta. Decreased placental JMJD6 expression may be an important component to the pathophysiology of preeclampsia.

The human endometrium is incredibly dynamic, undergoing monthly cycles of growth and regression during a woman's reproductive life. Endometrial repair at the cessation of menstruation is critical for reestablishment of a functional endometrium receptive for embryo implantation; however, little is understood about the mechanisms behind this rapid and highly efficient process. This study utilized a functional mouse model of endometrial breakdown and repair to assess changes in endometrial vasculature that accompany these dynamic processes. Given that adult endometrial stem/progenitor cells identified in human and mouse endometrium are likely contributors to the remarkable regenerative capacity of endometrium, we also assessed label-retaining cells (LRC) as candidate stromal stem/progenitor cells and examined their relationship with endometrial vasculature. Newborn mouse pups were pulse-labeled with bromodeoxyuridine (BrdU) and chased for 5 wk before decidualization, endometrial breakdown, and repair were induced by hormonal manipulation. Mean vessel density did not change significantly throughout breakdown and repair; however, significantly elevated endothelial cell proliferation was observed in decidual tissue. Stromal LRC were identified throughout breakdown and repair, with significantly fewer observed during endometrial repair than before decidualization. A significantly higher percentage of LRC were associated with vasculature during repair than before decidualization, and a proportion were undergoing proliferation, indicative of their functional capacity. This study is the first to examine the endometrial vasculature and candidate stromal stem/progenitor cells in a functional mouse model of endometrial breakdown and repair and provides functional evidence suggesting that perivascular LRC may contribute to endometrial stromal expansion during the extensive remodeling associated with this process.

Knowledge of the molecular mechanisms underlying menstruation and menstrual disorders is limited. We propose that menstrual disorders are a result of incorrect or inadequate endometrial restoration/healing after menses, and that this is likely to be similar to a wound healing event. Wound healing occurs in three phases; inflammation, tissue formation and tissue remodelling. Similar events occur within the uterus during menstruation including a well characterised cascade of inflammatory responses. Thereafter rapid re-epithelialisation of the uterine surface occurs within the first 48h after the first two menstrual days followed closely by renewal of the stromal compartment. Activins are members of the transforming growth factor β (TGFβ) superfamily and include activin A. Follistatin, also a member of the TGFβ family binds activins with high affinity and inhibits their biological activity. In vivo studies support a contribution of endogenous activins to wound healing (ref). In βA over-expressing mice the rate of skin wound healing is enhanced, whilst in follistatin over-expressing mice wound healing is considerably delayed. We hypothesised that activin would enhance endometrial healing in vitro and in vivo. This study aimed to examine the contribution of activins to the healing process using both an in vitro wound healing assay, and our well characterised mouse model of endometrial breakdown and repair. The human endometrial epithelial cell line, ECC-1 was used for the in vitro assay. Cells were grown to confluence and wounded by vacuum suction. Cells were treated with carrier protein (bovine serum albumin) alone, activin A (50ng/ml) or EGF (positive control: 50ng/ml) and wound areas (expressed as % repair from original wound size) were quantitated for 6 days. For the in vivo study, mice over-expressing follistatin and wild-type (WT) littermates were subjected to a well characterised protocol to induce endometrial breakdown and repair to mimic menstruation in women (ref). Alterations in repair between the two groups were assessed using a morphological scoring system designed for our mouse model. ECC-1 wound repair was significantly (p<0.05) enhanced by activin A treatment compared to control from days 2-6 of culture. In transgenic mice with circulating follistatin levels >3x those of WT littermates, only 50% of uterine sections assessed had completely repaired, compared to 85% of those from WT animals. Together these results provide functional evidence for a role for activin A in endometrial restoration following menses. This work further contributes to our understanding of the contribution of TGFβ superfamily members to endometrial biology, and provides new insights into possible treatment options for women suffering from menstrual disorders. Research supported by NHMRC of Australia (#388901) and an Australian Postgraduate Scholarship.