Preeclampsia: a defect in decidualization is associated with deficiency of Annexin A2

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

Factors Influencing Delayed Onset of Lactogenesis: A Scoping Review

Purpose

Delayed onset of lactogenesis is a significant barrier to achieving the WHO-recommended 50% exclusive breastfeeding rate in the first six months. This study maps the main factors influencing this condition, addressing gaps in the current research landscape.

Methods

Following Arksey and O'Malley's scoping review framework, databases such as PubMed, Web of Science (WOS), Embase, Cochrane Library, CINAHL plus with full text, China National Knowledge Infrastructure (CNIK), Weipu Chinese Journal Service Platform (VIP), Wanfang Data Knowledge Service Platform, and China Biomedical Literature Database (CBM) were searched on February 1, 2023. Studies in Chinese and English involving pregnant and postpartum women, focusing on delayed onset of lactogenesis, were included without restrictions on publication date or geography.

Results

Forty-six studies published between 2002 and 2022 met the inclusion criteria, revealing variable incidences of delayed lactogenesis among different groups. Thirty-four influencing factors were identified and organized into five themes: maternal-infant characteristics, perinatal mental state, physical activity participation during pregnancy, breastfeeding behaviors, and medical staff interventions. Within eighteen major factors highlighted, factors such as age, pre-pregnancy BMI, gestational weight gain, average LATCH score within 24 hours postpartum, labor analgesia, sleep, frequency of postpartum breastfeeding, and timing of initial breast suckling/pumping showed inconsistent or conflicting conclusions.

Conclusion

High and variable incidences of delayed lactogenesis underline its multifactorial nature. Effective interventions require strong advocacy from healthcare professionals and adherence by pregnant women. Further research using standardized methods is essential to clarify inconsistent or conflicting findings on the influencing factors.

Excessive endometrial PlGF- Rac1 signalling underlies endometrial cell stiffness linked to pre-eclampsia

Cell stiffness is regulated by dynamic interaction between ras-related C3 botulinum toxin substrate 1 (Rac1) and p21 protein-activated kinase 1 (PAK1) proteins, besides other biochemical and molecular regulators. In this study, we investigated how the Placental Growth Factor (PlGF) changes endometrial mechanics by modifying the actin cytoskeleton at the maternal interface. We explored the global effects of PlGF in endometrial stromal cells (EnSCs) using the concerted approach of proteomics, atomic force microscopy (AFM), and electrical impedance spectroscopy (EIS). Proteomic analysis shows PlGF upregulated RhoGTPases activating proteins and extracellular matrix organization-associated proteins in EnSCs. Rac1 and PAK1 transcript levels, activity, and actin polymerization were significantly increased with PlGF treatment. AFM further revealed an increase in cell stiffness with PlGF treatment. The additive effect of PlGF on actin polymerization was suppressed with siRNA-mediated inhibition of Rac1, PAK1, and WAVE2. Interestingly, the increase in cell stiffness by PlGF treatment was pharmacologically reversed with pravastatin, resulting in improved trophoblast cell invasion. Taken together, aberrant PlGF levels in the endometrium can contribute to an altered pre-pregnancy maternal microenvironment and offer a unifying explanation for the pathological changes observed in conditions such as pre-eclampsia (PE).

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

The role of the annexin A protein family at the maternal-fetal interface

Successful pregnancy requires the tolerance of the maternal immune system for the semi-allogeneic embryo, as well as a synchrony between the receptive endometrium and the competent embryo. The annexin family belongs to calcium-regulated phospholipid-binding protein, which functions as a membrane skeleton to stabilize the lipid bilayer and participate in various biological processes in humans. There is an abundance of the annexin family at the maternal-fetal interface, and it exerts a crucial role in embryo implantation and the subsequent development of the placenta. Altered expression of the annexin family and dysfunction of annexin proteins or polymorphisms of the ANXA gene are involved in a range of pregnancy complications. In this review, we summarize the current knowledge of the annexin A protein family at the maternal-fetal interface and its association with female reproductive disorders, suggesting the use of ANXA as the potential therapeutic target in the clinical diagnosis and treatment of pregnancy complications.

The mutation of NSUN5 R295C promotes preeclampsia by impairing decidualization through downregulating IL-11Rα

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder that severely impairs maternal and fetal health. However, its pathogenesis remains elusive. NOP2/Sun5 (NSUN5) is an RNA methyltransferase. This study discovered a significant correlation between rs77133388 of NSUN5 and PE in a cohort of 868 severe PE patients and 982 healthy controls. To further explore this association, the researchers generated single-base mutant mice (NSUN5 R295C) at rs77133388. The pregnant NSUN5 R295C mice exhibited PE symptoms. Additionally, compared to the controls, the decidual area of the placenta was significantly reduced in NSUN5 R295C mice, and their decidualization was impaired with a significantly decrease in polyploid cell numbers after artificially induced decidualization. The study also found a decrease in phosphorylated JAK2, STAT3, and IL-11Rα, Cyclin D3 expression in NSUN5 R295C mice. Overall, these findings suggest that NSUN5 mutation potentially alters decidualization through the IL-11Rα/JAK2/STAT3/Cyclin D3 pathway, ultimately impairing placental development and contributing to PE occurrence.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Spiral, uterine artery doppler and placental ultrasound in relation to preeclampsia

Preeclampsia (PE) is a multiorgan disorder that complicates around 2-8% of pregnancies and is a major cause of perinatal and maternal morbidity and mortality. PE is a clinical syndrome characterized by hypertension secondary to systemic inflammation, endothelial dysfunction, and syncytiotrophoblast stress leading to hypertension and multiorgan dysfunction. The uterine arteries are the main blood vessels that supply blood to the uterus. They give off branches and plays an important role in maintaining blood supply during pregnancy. The arcuate artery originates from the uterine artery and runs medially through the myometrium. The arcuate arteries divide almost directly into anterior and posterior branches, from which the radial artery leads directly to the uterine cavity during their course. Near the endometrium-myometrium junction, the radial artery generates spiral arteries within the basal layer and functional endometrium. The walls of radial and spiral arteries are rich in smooth muscle, which is lost when trophoblast cells invade and become large-caliber vessels. This physiological transformation of uteroplacental spiral arteries is critical for successful placental implantation and normal placental function. In normal pregnancy, the luminal diameter of the spiral arteries is greatly increased, and the vascular smooth muscle is replaced by trophoblast cells. This process and changes in the spiral arteries are called spiral artery remodeling. In PE, this genetically and immunologically governed process is deficient and therefore there is decreased vascular capacitance and increased resistance in the uteroplacental circulation. Furthermore, this defect in uteroplacental spiral artery remodeling is not only associated with early onset PE, but also with fetal growth restriction, placental abruption, and spontaneous premature rupture of membranes. Doppler ultrasound allows non-invasive assessment of placentation, while the flow impedance decreases as the pregnancy progresses in normal pregnancies, in those destined to develop preeclampsia the impedance is increased.

Immunologic aspects of preeclampsia

Preeclampsia is a syndrome with multiple etiologies. The diagnosis can be made without proteinuria in the presence of dysfunction of at least 1 organ associated with hypertension. The common pathophysiological pathway includes endothelial cell activation, intravascular inflammation, and syncytiotrophoblast stress. There is evidence to support, among others, immunologic causes of preeclampsia. Unlike defense immunology, reproductive immunology is not based on immunologic recognition systems of self/non-self and missing-self but on immunotolerance and maternal-fetal cellular interactions. The main mechanisms of immune escape from fetal to maternal immunity at the maternal-fetal interface are a reduction in the expression of major histocompatibility complex molecules by trophoblast cells, the presence of complement regulators, increased production of indoleamine 2,3-dioxygenase, activation of regulatory T cells, and an increase in immune checkpoints. These immune protections are more similar to the immune responses observed in tumor biology than in allograft biology. The role of immune and nonimmune decidual cells is critical for the regulation of trophoblast invasion and vascular remodeling of the uterine spiral arteries. Regulatory T cells have been found to play an important role in suppressing the effectiveness of other T cells and contributing to local immunotolerance. Decidual natural killer cells have a cytokine profile that is favored by the presence of HLA-G and HLA-E and contributes to vascular remodeling. Studies on the evolution of mammals show that HLA-E, HLA-G, and HLA-C1/C2, which are expressed by trophoblasts and their cognate receptors on decidual natural killer cells, are necessary for the development of a hemochorial placenta with vascular remodeling. The activation or inhibition of decidual natural killer cells depends on the different possible combinations between killer cell immunoglobulin-like receptors, expressed by uterine natural killer cells, and the HLA-C1/C2 antigens, expressed by trophoblasts. Polarization of decidual macrophages in phenotype 2 and decidualization of stromal cells are also essential for high-quality vascular remodeling. Knowledge of the various immunologic mechanisms required for adequate vascular remodeling and their dysfunction in case of preeclampsia opens new avenues of research to identify novel biological markers or therapeutic targets to predict or prevent the onset of preeclampsia.

Advances in understanding canine pregnancy: Endocrine and morpho-functional regulation

Canine pregnancy relies on luteal steroidogenesis for progesterone (P4) production. The canine placenta responds to P4, depending on the nuclear P4 receptor (PGR). This has sparked interest in investigating the interaction between ovarian luteal steroids and the placenta in dogs. Canine placentation is characterized by restricted (shallow) trophoblast invasion, making the dog an interesting model for studying decidua-derived modulation of trophoblast invasion, compared with the more invasive (hemochorial) placentation. The PGR is expressed in maternally derived decidual cells and plays a crucial role in feto-maternal communication during pregnancy maintenance. Understanding PGR-mediated signalling has clinical implications for improving reproductive performance control in dogs. Altering the PGR signalling induces the release of PGF2α from the foetal trophoblast, hindering placental homeostasis, which can also be achieved with antigestagens like aglepristone. Consequently, luteolysis, both natural and antigestagen-induced, involves apoptosis, vascular lesion, and immune cell infiltration in the placenta, resulting in placentolysis and foetal membranes expulsion. Our laboratory developed the immortalized dog uterine stromal (DUS) cell line to study canine-specific decidualization. We study canine reproduction by observing physiological processes and investigating evidence-based mechanisms of decidualization and feto-maternal interaction. Our focus on morphology, function and molecular aspects enhances understanding and enables targeted and translational studies.

Associations between IGFBP1 gene polymorphisms and the risk of preeclampsia and fetal growth restriction

IGFBP1 plays a critical role in the pathogenesis of preeclampsia (PE), but the association between single nucleotide polymorphism (SNP) of IGFBP1 gene and PE susceptibility has not yet been determined. In our study, 229 women with PE and 361 healthy pregnant (non-PE) women were enrolled to investigate its association via TaqMan genotyping assay. In addition, the protein levels of IGFBP1 under different genotypes were explored by ELISA and IHC. We found that IGFBP1 SNP rs1065780A > G was associated with an decreased risk for PE. Women with GG (P = 0.027) or AG (Padj. = 0.023) genotype manifested a significantly lower risk for PE compared to women with AA genotype. In PE group, women carrying G allele exhibited greater fetal birth weight, lower diastolic BP, and lower levels of ALT and AST. The G genotype was found significantly less frequently in the severe preeclampsia (SPE) group than in the non-PE group (GG vs. AA, P = 0.007; G vs. A, P = 0.006). Additionally, women in the PE group who experienced fetal growth restriction (FGR) reflected a lower level of the allele G than did the non-FGR group (P = 0.032); this was not the case for the non-PE group.Rs1065780A>G elevated IGFBP1 protein level in plasma and decidua in PE group. In conclusion Chinese Han women with the SNP IGFBP1 rs1065780 occupied by G exhibited a lower risk of developing PE relative to women with the A genotype and augured for improved pregnancy outcomes through elevation of IGFBP1 protein level.

Association between pregnant women with rheumatoid arthritis and preeclampsia: A systematic review and meta-analysis

BACKGROUND

To examine the association between pregnant women with rheumatoid arthritis (RA) and the risk of preeclampsia.

METHODS

This study was registered on the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42022361571. The primary outcome was preeclampsia. Two evaluators independently reviewed the included studies, assessed their risk of bias, and extracted the data. Unadjusted and adjusted ratios with 95% confidence intervals and 95% prediction intervals were calculated. Heterogeneity was quantified using the І2 statistic, where І2 ≥ 50% indicated the presence of significant heterogeneity. Subgroup and sensitivity analyses were performed to test the robustness of the overall findings.

RESULTS

A total of 8 studies, including 10,951,184 pregnant women, of whom 13,333 were diagnosed with RA, met the inclusion criteria. Meta-analysis revealed that pregnant women with RA were significantly more likely to develop preeclampsia than those without RA (pooled odds ratio, 1.66; 95% confidence interval, 1.52-1.80; P < .001; І2 < .001).

CONCLUSION

RA during pregnancy is associated with higher odds of preeclampsia.

lincRNA RP24-315D19.10 promotes endometrial decidualization via upregulation of hnRNPA2B1

Decidualization is a critical process for successful pregnancy. Disorders in this process are tightly associated with adverse pregnancy outcomes including spontaneous abortion. However, the potential molecular mechanisms of lncRNAs underlying this process are yet to be fully elucidated. In this study, we utilized RNA sequencing (RNA-seq) to identify differentially expressed lncRNAs during endometrial decidualization with a pregnant mouse model. Based on RNA-seq analysis, weighted gene co-expression network analysis (WGCNA) was performed to construct the lncRNA-mRNA co-expression network and to identify decidualization-associated hub lncRNAs. Through comprehensive screening and validation, we identified a novel lncRNA, RP24-315D19.10 and studied its function in primary mouse endometrial stromal cells (mESCs). lncRNA RP24-315D19.10 was highly expressed during decidualization. Knockdown of RP24-315D19.10 significantly inhibited mESCs decidualization in vitro. Mechanistically, RNA pull-down and RNA immunoprecipitation assays indicated that cytoplasmic RP24-315D19.10 could bind to hnRNPA2B1, thereby upregulating hnRNPA2B1 expression. Site-directed mutagenesis followed by biolayer interferometry analysis additionally illustrated that hnRNPA2B1 protein specifically bound to the ~-142ccccc~-167 region of the RP24-315D19.10 sequence. hnRPA2B1 deficiency impairs mESCs decidualization in vitro and we found that the inhibition in decidualization caused by RP24-315D19.10 knockdown was rescued by hnRNPA2B1 overexpression. Moreover, the expression of hnRNPA2B1 in spontaneous abortion women with deficient decidualization was significantly lower than that in healthy individuals, suggesting that hnRNPA2B1 may be involved in the development and progression of spontaneous abortion caused by decidualization failure. Collectively, our study indicates RP24-315D19.10 is a critical regulator for endometrial decidualization and RP24-315D19.10-regulated hnRNPA2B1 might be a new mark of decidualization-related spontaneous abortion.

The Enzyme 15-Hydroxyprostaglandin Dehydrogenase Inhibits a Shift to the Mesenchymal Pattern of Trophoblasts and Decidual Stromal Cells Accompanied by Prostaglandin Transporter in Preeclampsia

Preeclampsia (PE) is a pregnancy complication beginning after 20 weeks of pregnancy that involves high blood pressure (systolic > 140 mmHg or diastolic > 90 mmHg), with or without proteinuria. Insufficient trophoblast invasion and abnormal decidualization are involved in PE development. However, whether unhealthy placenta and decidua have the same biological activities is unclear. The enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH; encoded by HPGD) degrades prostaglandin, and prostaglandin transporter (PGT), as a candidate molecule of prostaglandin carriers, helps transport prostaglandin into cells. Whether 15-PGDH and PGT are involved in PE has not been researched. In this study, we investigated the shared pathogenesis of foetal placenta and maternal decidua from the perspective of epithelial–mesenchymal transition (EMT)/mesenchymal–epithelial transition (MET) and explored the combined effects of 15-PGDH and PGT on the EMT/MET of trophoblasts and decidual stromal cells (DSCs). Here, we demonstrated that placental development and decidualization both involved EMT/MET. In PE, both trophoblasts and DSCs show more epithelial patterns. Moreover, 15-PGDH expression was downregulated in the placentas but upregulated in the deciduas of PE patients. Inhibiting 15-PGDH promotes a shift to a mesenchymal pattern of trophoblasts and DSCs depending on the PGT-mediated transport of prostaglandin E2 (PGE2). In conclusion, our results showed that inhibiting 15-PGDH promotes a shift to the mesenchymal pattern of trophoblasts and DSCs and may provide a new and alternative therapy for the treatment of PE.

Endometrial Inflammation and Impaired Spontaneous Decidualization: Insights into the Pathogenesis of Adenomyosis

Adenomyosis is an estrogen-dependent gynecologic disease characterized by the myometrial invasion of the endometrial tissue. This review summarized the current understanding and recent findings on the pathophysiology of adenomyosis, focusing on repeated menstruation, persistent inflammation, and impaired spontaneous decidualization. A literature search was performed in the PubMed and Google Scholar databases from inception to 30 April 2022. Thirty-one full-text articles met the eligibility criteria. Repeated episodes of physiological events (i.e., endometrial shedding, damage, proliferation, differentiation, repair, and regeneration) during the menstrual cycle are associated with inflammation, angiogenesis, and immune processes. The decidualization process in humans is driven by the rise in progesterone levels, independently of pregnancy (i.e., spontaneous decidualization). Adenomyotic cells produce angiogenic and fibrogenic factors with the downregulation of decidualization-associated molecules. This decidualization dysfunction and persistent inflammation are closely related to the pathogenesis of adenomyosis. Recently, it has been found that the reproductive tract microbiota composition and function in women with adenomyosis differ from those without. An increase in opportunistic pathogens and a decrease in beneficial commensals may promote impaired defense mechanisms against inflammation and predispose women to uncontrolled endometrial inflammation. However, currently, there is no direct evidence that adenomyosis is linked to pre-existing inflammation and impaired spontaneous decidualization. Overall, persistent inflammation, impaired spontaneous decidualization, and microbiota dysbiosis (i.e., an imbalance in the composition and function of endometrial microbiota) may be involved in the pathophysiology of adenomyosis.

Annexin A2 modulates phospholipid membrane composition upstream of Arp2 to control angiogenic sprout initiation

The intersection of protein and lipid biology is of growing importance for understanding how cells address structural challenges during adhesion and migration. While protein complexes engaged with the cytoskeleton play a vital role, support from the phospholipid membrane is crucial for directing localization and assembly of key protein complexes. During angiogenesis, dramatic cellular remodeling is necessary for endothelial cells to shift from a stable monolayer to invasive structures. However, the molecular dynamics between lipids and proteins during endothelial invasion are not defined. Here, we utilized cell culture, immunofluorescence, and lipidomic analyses to identify a novel role for the membrane binding protein Annexin A2 (ANXA2) in modulating the composition of specific membrane lipids necessary for cortical F-actin organization and adherens junction stabilization. In the absence of ANXA2, there is disorganized cortical F-actin, reduced junctional Arp2, excess sprout initiation, and ultimately failed sprout maturation. Furthermore, we observed reduced filipin III labeling of membrane cholesterol in cells with reduced ANXA2, suggesting there is an alteration in phospholipid membrane dynamics. Lipidomic analyses revealed that 42 lipid species were altered with loss of ANXA2, including an accumulation of phosphatidylcholine (16:0_16:0). We found that supplementation of phosphatidylcholine (16:0_16:0) in wild-type endothelial cells mimicked the ANXA2 knock-down phenotype, indicating that ANXA2 regulated the phospholipid membrane upstream of Arp2 recruitment and organization of cortical F-actin. Altogether, these data indicate a novel role for ANXA2 in coordinating events at endothelial junctions needed to initiate sprouting and show that proper lipid modulation is a critical component of these events.

Impact of endometrial claudin-3 deletion on murine implantation, decidualization and embryo development

The composition of cell contacts in the endometrium plays an important role in the process of embryo implantation and the establishment of pregnancy. In previous studies, we showed an induction of the tight junction protein claudin-3 in the developing decidua from 6.5 dpc onwards. To evaluate the role if this specific claudin-3 distribution, we here evaluated the effect of an endometrial claudin-3 deletion in implantation and embryo development in claudin-3 knockout mice. Claudin-3 KO mice were fertile but revealed a slightly reduced amount of implantation sites as well as of litter size. Though implantation sites showed morphologically regularly developed embryos and deciduas, depth of ectoplacental cone invasion was reduced in tendency compared to controls. The weight of the implantation sites on 6.5 and 8.5 dpc as well as the weight of the embryos on 17.5 dpc, but not of the placentas, was significantly reduced in claudin-3 KO mice due to a maternal effect. This could be due to an impairment of decidualization as substantiated by a downregulation of the transcription of various decidua-associated genes in the early implantation sites of claudin-3 KO mice. The fact that claudin-3 KO mice are nevertheless fertile possibly may be compensated by the presence of other claudins like claudin-4 and claudin-10.

LncRNA MALAT1 promotes decidualization of endometrial stromal cells via sponging miR-498-3p and targeting histone deacetylase 4

Decidualization of human endometrial stromal cells (hESCs) is important for the maintenance of a successful pregnancy. Histone deacetylase 4 (HDAC4) was reported to be involved in the dysfunction of decidua-derived mesenchymal stem cells. However, the role of HDAC4 underlying decidualization of hESCs remains unclear. We intended to explore the function and molecular mechanism of HDAC4 in hESCs. In vitro expansion of hESCs using a serum-free medium was used to confirm the characteristics of hESCs. Gene expression in hESCs was evaluated by reverse transcription-quantitative polymerase chain reaction. CCK-8 assay, TUNEL staining, flow cytometry analysis, and Western blot analysis were performed to test the effects of HDAC4 and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on hESCs. RNA pull-down and luciferase reporter assays were performed to validate the relationship between genes. In this study, the characteristics of hESCs were sustained in serum-free medium during a process of propagation. HDAC4 knockdown suppressed hESCs viability and promoted hESCs apoptosis. HDAC4 was targeted by miR-498-3p in hESCs. MALAT1 bound with miR-498-3p in hESCs. HDAC4 expression was positively regulated by MALAT1 and negatively regulated by miR-498-3p in hESCs. HDAC4 upregulation countervailed the effects of MALAT1 silencing on hESCs proliferation, apoptosis, and decidualization of hESCs. Overall, MALAT1 facilitated the decidualization of hESCs via binding with miR-498-3p and upregulating HDAC4, which might provide a new direction for the maintenance of a successful pregnancy.

Identification of nucleotide polymorphisms in the key promoter region of chicken annexins A2 gene associatied with egg laying traits

Annexin A2 (ANXA2) is a member of the A subfamily of a multifunctional calcium dependent membrane phospholipid binding protein family. The mRNA expression of ANXA2 is consistent with ovary function and egg laying in chickens. In this study, six nucleotide polymorphisms in the key promoter region of chicken ANXA2 gene (-2861 bp to -1394 bp), i.e.,: g.-2337 indel (GT), g.-2255 C > T, g. -2248 A > G, g.-2188 A > G, g.-2169 G > A, g.-2160 A > C, were identified. Their distributions in populations of Xinyang Brown, Recessive White Rock, Wenchang and Wenshang Barred chickens were analyzed. In the Recessive White Rock chicken population, CAA, CAG and TGG were three major haplotypes. Association analysis indicated that the individuals with diplotype TGG/TGG laid more eggs at 32 weeks, and the individual with diplotype CAG/TGG laid at the earlier age. Luciferase activity assay showed that mutation from C to T at -2255 increased trascriptional activity of chicken ANXA2, which is consistent with its effect on egg laying traits.

First trimester preeclampsia screening and prediction

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. Early-onset disease requiring preterm delivery is associated with a higher risk of complications in both mothers and babies. Evidence suggests that the administration of low-dose aspirin initiated before 16 weeks' gestation significantly reduces the rate of preterm preeclampsia. Therefore, it is important to identify pregnant women at risk of developing preeclampsia during the first trimester of pregnancy, thus allowing timely therapeutic intervention. Several professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) and National Institute for Health and Care Excellence (NICE) have proposed screening for preeclampsia based on maternal risk factors. The approach recommended by ACOG and NICE essentially treats each risk factor as a separate screening test with additive detection rate and screen-positive rate. Evidence has shown that preeclampsia screening based on the NICE and ACOG approach has suboptimal performance, as the NICE recommendation only achieves detection rates of 41% and 34%, with a 10% false-positive rate, for preterm and term preeclampsia, respectively. Screening based on the 2013 ACOG recommendation can only achieve detection rates of 5% and 2% for preterm and term preeclampsia, respectively, with a 0.2% false-positive rate. Various first trimester prediction models have been developed. Most of them have not undergone or failed external validation. However, it is worthy of note that the Fetal Medicine Foundation (FMF) first trimester prediction model (namely the triple test), which consists of a combination of maternal factors and measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has undergone successful internal and external validation. The FMF triple test has detection rates of 90% and 75% for the prediction of early and preterm preeclampsia, respectively, with a 10% false-positive rate. Such performance of screening is superior to that of the traditional method by maternal risk factors alone. The use of the FMF prediction model, followed by the administration of low-dose aspirin, has been shown to reduce the rate of preterm preeclampsia by 62%. The number needed to screen to prevent 1 case of preterm preeclampsia by the FMF triple test is 250. The key to maintaining optimal screening performance is to establish standardized protocols for biomarker measurements and regular biomarker quality assessment, as inaccurate measurement can affect screening performance. Tools frequently used to assess quality control include the cumulative sum and target plot. Cumulative sum is a sensitive method to detect small shifts over time, and point of shift can be easily identified. Target plot is a tool to evaluate deviation from the expected multiple of median and the expected median of standard deviation. Target plot is easy to interpret and visualize. However, it is insensitive to detecting small deviations. Adherence to well-defined protocols for the measurements of mean arterial pressure, uterine artery pulsatility index, and placental growth factor is required. This article summarizes the existing literature on the different methods, recommendations by professional organizations, quality assessment of different components of risk assessment, and clinical implementation of the first trimester screening for preeclampsia.

Decidualization resistance in the origin of preeclampsia

Preeclampsia is a major obstetrical complication with short- and long-term life-threatening consequences for both mother and child. Shallow cytotrophoblast invasion through the uterine decidua into the spiral arteries is implicated in the pathogenesis of preeclampsia, although the cause of deficient arterial invasion remains unknown. Research that is focused on the "soil"-the maternal decidua-highlights the importance of this poorly understood but influential uterine layer. Decidualization of endometrial cells regulates embryo invasion, which is essential for spiral artery remodeling and establishing the maternal-fetal interface. Exploration of the association between impaired decidualization and preeclampsia revealed suboptimal endometrial maturation and uterine natural killer cells present in the decidua before preeclampsia development. Furthermore, decidualization defects in the endometrium of women with severe preeclampsia, characterized by impaired cytotrophoblast invasion, were detected at the time of delivery and persisted 5 years after the affected pregnancy. Recently, a maternal deficiency of annexin A2 expression was found to influence aberrant decidualization and shallow cytotrophoblast invasion, suggesting that decidualization resistance, which is a defective endometrial cell differentiation during the menstrual cycle, could underlie shallow trophoblast invasion and the poor establishment of the maternal-fetal interface. Based on these findings, the transcriptional signature in the endometrium that promotes decidualization deficiency could be detected before (or after) conception. This would serve to identify women at risk of developing severe preeclampsia and aid the development of therapies focused on improving decidualization, perhaps also preventing severe preeclampsia. Here, we discuss decidualization deficiency as a contributor to the pathogenesis of pregnancy disorders with particular attention to severe preeclampsia. We also review current diagnostic strategies and discuss future directions in diagnostic methods based on decidualization.

Dysregulated GLUT1 may be involved in the pathogenesis of preeclampsia by impairing decidualization

Preeclampsia (PE), a hypertensive complication in pregnancy, is a major contributor to maternal and fetal morbidity and mortality. PE has long been regarded a heterogeneous disorder with a pathogenesis that involves multiple genes and factors. Glucose transporter 1 (GLUT1) is a central rate-limiting pump that is involved in glucose uptake and subsequent utilization. Our previous RNA-seq results demonstrated GLUT1 was significantly downregulated in deciduas from patients with severe PE. Therefore, in this study, we aimed to explore the role of GLUT1 in the occurrence of PE. Our data showed that mRNA and protein levels of GLUT1 were significantly downregulated in the deciduas from patients with severe PE. Additionally, GLUT1 levels were substantially upregulated in human endometrial stromal cells (HESCs) during in vitro decidualization. Moreover, GLUT1 knockdown significantly reduced the mRNA levels of decidualization markers (IGFBP1 and PRL) and aerobic glycolysis-related genes (LDHA and MCT4), as well as decreased glucose uptake and lactate production. Furthermore, upon GLUT1 knockdown, the levels of apoptotic genes P53, P21, and BAX increased whereas the level of BCL2 decreased. Target prediction results and luciferase analysis showed that GLUT1 is one of the targets of miR-140-5p, which is partly responsible for downregulated GLUT1 levels. Collectively, these results demonstrate that GLUT1 exerts a pivotal role in human decidualization by participating in glycolysis, and that GLUT1 deficiency may trigger aberrant glycolysis, thereby leading to destructive decidualization that may impede blastocyst implantation, trophoblast invasion, and subsequent placental development, which are associated with PE. Taken together, these data suggest that GLUT1 might be a promising target for PE therapy.

Proteomic analysis of extracellular vesicles secreted by primary human epithelial endometrial cells reveals key proteins related to embryo implantation

BACKGROUND

Successful implantation is dependent on coordination between maternal endometrium and embryo, and the role of EVs in the required cross-talk cell-to-cell has been recently established. In this regard, it has been reported that EVs secreted by the maternal endometrium can be internalized by human trophoblastic cells transferring their contents and enhancing their adhesive and invasive capacity. This is the first study to comprehensively evaluate three EV isolation methods on human endometrial epithelial cells in culture and to describe the proteomic content of EVs secreted by pHEECs from fertile women.

METHODS

Ishikawa cells and pHEECs were in vitro cultured and hormonally treated; subsequently, conditioned medium was collected and EVs isolated. Ishikawa cells were used for the comparison of EVs isolation methods ultracentrifugation, ExoQuick-TC and Norgen Cell Culture Media Exosome Purification Kit (n = 3 replicates/isolation method). pHEECs were isolated from endometrial biopsies (n = 8/replicate; 3 replicates) collected from healthy oocyte donors with confirmed fertility, and protein content of EVs isolated by the most efficient methodology was analysed using liquid chromatography-tandem mass spectrometry. EV concentration and size were analyzed by nanoparticle tracking analysis, EV morphology visualized by transmission electron microscopy and protein marker expression was determined by Western blotting.

RESULTS

Ultracentrifugation was the most efficient methodology for EV isolation from medium of endometrial epithelial cells. EVs secreted by pHEECs and isolated by ultracentrifugation were heterogeneous in size and expressed EV protein markers HSP70, TSG101, CD9, and CD81. Proteomic analysis identified 218 proteins contained in these EVs enriched in biological processes involved in embryo implantation, including cell adhesion, differentiation, communication, migration, extracellular matrix organization, vasculature development, and reproductive processes. From these proteins, 82 were selected based on their functional relevance in implantation success as possible implantation biomarkers.

CONCLUSIONS

EV protein cargos are implicated in biological processes related to endometrial receptivity, embryo implantation, and early embryo development, supporting the concept of a communication system between the embryo and the maternal endometrium via EVs. Identified proteins may define new biomarkers of endometrial receptivity and implantation success.

SARS-CoV-2 infection during pregnancy and risk of preeclampsia: a systematic review and meta-analysis

OBJECTIVE

To examine the relationship between SARS-CoV-2 infection during pregnancy and the risk for preeclampsia.

DATA SOURCES

MEDLINE, Embase, POPLINE, CINAHL, LILACS, and the World Health Organization COVID-19, Chinese, and preprint databases (all from December 1, 2019, to May 31, 2021). Google Scholar, bibliographies, and conference proceedings were also searched.

STUDY ELIGIBILITY CRITERIA

Observational studies that assessed the association between SARS-CoV-2 infection during pregnancy and preeclampsia and that reported unadjusted and/or adjusted risk estimates and 95% confidence intervals or data to calculate them.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was preeclampsia. Secondary outcomes included preeclampsia with severe features, preeclampsia without severe features, eclampsia, and hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. Two reviewers independently reviewed studies for inclusion, assessed their risk of bias, and extracted data. Pooled unadjusted and adjusted odds ratios with 95% confidence intervals, and 95% prediction interval were calculated. Heterogeneity was quantified using the І2 statistic, for which І2≥30% indicated substantial heterogeneity. Subgroup and sensitivity analyses were performed to test the robustness of the overall findings.

RESULTS

A total of 28 studies comprising 790,954 pregnant women, among which 15,524 were diagnosed with SARS-CoV-2 infection, met the inclusion criteria. The meta-analysis of unadjusted odds ratios showed that the odds of developing preeclampsia were significantly higher among pregnant women with SARS-CoV-2 infection than among those without SARS-CoV-2 infection (7.0% vs 4.8%; pooled odds ratio, 1.62; 95% confidence interval, 1.45-1.82; P<.00001; І2=17%; 26 studies; 95% prediction interval of the odds ratio, 1.28-2.05). The meta-analysis of adjusted odds ratios also showed that SARS-CoV-2 infection during pregnancy was associated with a significant increase in the odds of preeclampsia (pooled odds ratio, 1.58; 95% confidence interval, 1.39-1.80; P<.0001; І2=0%; 11 studies). There was a statistically significant increase in the odds of preeclampsia with severe features (odds ratio, 1.76; 95% confidence interval, 1.18-2.63; І2=58%; 7 studies), eclampsia (odds ratio, 1.97; 95% confidence interval, 1.01-3.84; І2=0%, 3 studies), and HELLP syndrome (odds ratio, 2.10; 95% confidence interval, 1.48-2.97; 1 study) among pregnant women with SARS-CoV-2 infection when compared to those without the infection. Overall, the direction and magnitude of the effect of SARS-CoV-2 infection during pregnancy on preeclampsia was consistent across most prespecified subgroup and sensitivity analyses. Both asymptomatic and symptomatic SARS-CoV-2 infections significantly increased the odds of developing preeclampsial; however, it was higher among patients with symptomatic illness (odds ratio, 2.11; 95% confidence interval, 1.59-2.81) than among those with asymptomatic illness (odds ratio, 1.59; 95% confidence interval, 1.21-2.10).

CONCLUSION

SARS-CoV-2 during pregnancy is associated with higher odds of preeclampsia.

Vascular Dysfunction in Preeclampsia

Preeclampsia is a life-threatening pregnancy-associated cardiovascular disorder characterized by hypertension and proteinuria at 20 weeks of gestation. Though its exact underlying cause is not precisely defined and likely heterogenous, a plethora of research indicates that in some women with preeclampsia, both maternal and placental vascular dysfunction plays a role in the pathogenesis and can persist into the postpartum period. Potential abnormalities include impaired placentation, incomplete spiral artery remodeling, and endothelial damage, which are further propagated by immune factors, mitochondrial stress, and an imbalance of pro- and antiangiogenic substances. While the field has progressed, current gaps in knowledge include detailed initial molecular mechanisms and effective treatment options. Newfound evidence indicates that vasopressin is an early mediator and biomarker of the disorder, and promising future therapeutic avenues include mitigating mitochondrial dysfunction, excess oxidative stress, and the resulting inflammatory state. In this review, we provide a detailed overview of vascular defects present during preeclampsia and connect well-established notions to newer discoveries at the molecular, cellular, and whole-organism levels.

Disrupted PGR-B and ESR1 signaling underlies defective decidualization linked to severe preeclampsia

Background:

Decidualization of the uterine mucosa drives the maternal adaptation to invasion by the placenta. Appropriate depth of placental invasion is needed to support a healthy pregnancy; shallow invasion is associated with the development of severe preeclampsia (sPE). Maternal contribution to sPE through failed decidualization is an important determinant of placental phenotype. However, the molecular mechanism underlying the in vivo defect linking decidualization to sPE is unknown.

Methods:

Global RNA sequencing was applied to obtain the transcriptomic profile of endometrial biopsies collected from nonpregnant women who suffer sPE in a previous pregnancy and women who did not develop this condition. Samples were randomized in two cohorts, the training and the test set, to identify the fingerprinting encoding defective decidualization in sPE and its subsequent validation. Gene Ontology enrichment and an interaction network were performed to deepen in pathways impaired by genetic dysregulation in sPE. Finally, the main modulators of decidualization, estrogen receptor 1 (ESR1) and progesterone receptor B (PGR-B), were assessed at the level of gene expression and protein abundance.

Results:

Here, we discover the footprint encoding this decidualization defect comprising 120 genes—using global gene expression profiling in decidua from women who developed sPE in a previous pregnancy. This signature allowed us to effectively segregate samples into sPE and control groups. ESR1 and PGR were highly interconnected with the dynamic network of the defective decidualization fingerprint. ESR1 and PGR-B gene expression and protein abundance were remarkably disrupted in sPE.

Conclusions:

Thus, the transcriptomic signature of impaired decidualization implicates dysregulated hormonal signaling in the decidual endometria in women who developed sPE. These findings reveal a potential footprint that could be leveraged for a preconception or early prenatal screening of sPE risk, thus improving prevention and early treatments.

Funding:

This work has been supported by the grant PI19/01659 (MCIU/AEI/FEDER, UE) from the Spanish Carlos III Institute awarded to TGG. NCM was supported by the PhD program FDGENT/2019/008 from the Spanish Generalitat Valenciana. IMB was supported by the PhD program PRE2019-090770 and funding was provided by the grant RTI2018-094946-B-100 (MCIU/AEI/FEDER, UE) from the Spanish Ministry of Science and Innovation with CS as principal investigator. This research was funded partially by Igenomix S.L.

Network Pharmacology-based and Molecular Docking Analysis of Resveratrol's Pharmacological Effects on Type I Endometrial Cancer

Background

Resveratrol is a natural polyphenol commonly seen in foods. It has demonstrated an inhibitive effect on endometrial cancer, but the molecular action is still not known.

Objective

We aimed to use network pharmacology to systematically study the possible mechanisms of resveratrol’s pharmacological effects on type I endometrial cancer.

Methods

Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) were used to predict resveratrol’s possible target genes. They were then converted to UniProt gene symbols. Simultaneously, type I endometrial cancer-related target genes were collected from GeneCards. All data were pooled to identify common target genes. The protein-protein interaction (PPI) network was constructed and further analyzed via STRING Online Database. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were also performed afterward. To visualise resveratrol's overall pharmacological effects on type I endometrial cancer, a network of drug components-target gene-disease (CTD) was constructed. Then, we performed in silico molecular docking study to validate the possible binding conformation between resveratrol and candidate targets.

Results

There are 150 target genes of resveratrol retrieved after UniProt conversion; 122 of them shared interaction with type I endometrial cancer. Some important oncogenes and signaling pathways are involved in the process of resveratrol’s pharmacological effects on endometrioid cancer. Molecular docking analysis confirmed that hydrogen bonding and hydrophobic interaction are the main interaction between resveratrol and its targets.

Conclusion

We have explored the possible underlying mechanism of resveratrol in antagonising type I endometrial cancer through a network pharmacology-based approach and in-silico verification. However, further experiments are necessary to add to the evidence identifying resveratrol as a promising anti-type I endometrial cancer agent.

Annexin A2 acts as an adherent molecule under the regulation of steroids during embryo implantation

We previously showed that annexin A2 (Axna2) was transiently expressed at the embryo-uterine luminal epithelium interface during the window of implantation and was involved in mouse embryo implantation. At the same time, Axna2 was reported to be upregulated in human receptive endometrium, which was critical for embryo attachment as an intracellular molecule. Here, we identified Axna2 as a membrane-bound molecule on human endometrial epithelial cells and trophoblast cells, and the outer surface membrane-bound Axna2 was involved in human embryo attachment. In addition, physiological levels of estrogen and progesterone increased the expression of overall Axna2 as well as that in the extracellular surface membrane protein fraction in human endometrial cells. Furthermore, p11 (or S100A10, a member of the S100 EF-hand family protein, molecular weight 11 kDa) was involved in the translocation of Axna2 to the outer surface membrane of endometrial epithelial cells without affecting its overall expression. Finally, the surface relocation of Axna2 was also dependent on cell-cell contact and calcium binding. A better understanding of the function and regulation of Axna2 in human endometrium may help us to identify a potential therapeutic target for subfertile and infertile patients.

Expression and significance of let-7a and tumor necrosis factor-alpha in placenta of severe preeclampsia

OBJECTIVE

To investigate the expression and clinical significance of let-7a and tumor necrosis factor-alpha (TNF-α) in placental tissue of patients with severe preeclampsia (SPE).

METHODS

From January 2018 to October 2019, 64 cases of puerperal delivery at the First People's Hospital of Lianyungang City, 44 cases of SPE (SPE group), and 20 cases of healthy pregnant women (NC group) were selected. QRT-PCR and Western-blot were used to detect the expression levels of let-7a, TNF-αmRNA, and protein in the two groups of placental tissues. The correlation and the clinical significance of the two were statistically analyzed.

RESULTS

The relative expression of let-7a in the SPE group was significantly lower than that in the control group (0.06 ± 0.02 versus 0.25 ± 0.04, p < .05); the expression of TNF-αmRNA in the SPE group was significantly higher than that in the control group (0.48 ± 0.04 versus 0.17 ± 0.03, p < .05); TNF-α protein expression was significantly increased in the SPE group (1.09 ± 0.12 versus 0.56 ± 0.03, p < .05); let-7a and TNF-α were significantly negatively correlated (r = -0.41, p < .05); the blood pressure and birth weight of the pregnant women in the SPE group and the control group were significantly different [systolic blood pressure (164.27 ± 4.62) mmHg versus (125.01 ± 2.23)] mmHg, diastolic blood pressure (109.24 ± 2.97) mmHg versus (75.94 ± 2.74) mmHg, neonatal birth weight (2507.02 ± 161.46) g versus (3592.12 ± 153.05) g, p < .05]; the expression of TNF-α in placental tissue of SPE group was significantly positively correlated with systolic and diastolic blood pressure (r = 0.93 and 0.89, p < .05).

CONCLUSION

let-7a may participate in the occurrence and development of SPE by negatively regulating the expression of TNF-α.

Screening Candidate Genes Regulating Placental Development from Trophoblast Transcriptome at Early Pregnancy in Dazu Black Goats (Capra hircus)

Simple Summary

The trophoblast is an original placental tissue whose normal proliferation, differentiation, migration, adhesion, and angiopoiesis are essential for placenta formation and fetal survival during early pregnancy. However, the key genes and molecular mechanisms involved in placenta development in goats are unknown. Herein, the morphology and histological structures of trophoblast tissues from day 20 to 30 of pregnancy were determined. RNA-sequencing was used to screen potential functional genes in common highly expressed and differentially expressed genes. RAP1 signaling pathway was used as the contact center and coordinated with other pathways to regulate placenta development. This study could provide insights into the molecular mechanisms underlying ruminant placentation.

Abstract

This study explored the trophoblast transcriptome to understand potential functional genes involved in early placental development in goats and their enriched signaling pathways. Trophoblast samples were collected from nine Dazu Black goats on days 20, 25, and 30 of pregnancy (D20, D25, and D30). As the pregnancy progressed, the morphology and histological structures showed significant growth, adhesion, and angiogenesis. A total of 23,253 commonly expressed genes (CEGs) and 4439 differently expressed genes (DEGs) were detected by RNA sequencing. The common highly expressed genes (ChEGs) (the top 100 CEGs) with the highest FPKM percentage (29.9%) of all CEGs were annotated to the ribosome pathway and maintain pregnancy. DEGs were abundant in D30 vs. D20 (3715 DEGs). Besides, the DEGs were associated with the inhibition of oxidative phosphorylation and activation of PI3K-Akt, focal adhesion, ECM–receptor interaction, Rap1, and CAM signaling pathways. The RAP1 may be a central pathway since it coordinates with others to regulate the cell proliferation, invasion, migration, and fusion of trophoblasts. qRT-PCR and Western blot analysis confirmed the transcriptional expression in IGF1, VEGFC, RAPGEF3, PIK3CA, AKT3, ITGB3, ITGA11, SPP1, NOS1, and ATP6V0B genes and protein levels in VEGF, RAPGEF3, and Akt. This is the first study of transcriptome profiling in goat placenta and provides diverse genetic resources for further research on placenta development.

Clinical consequences of defective decidualization

Decidualization is characterized by a series of genetic, metabolic, morphological, biochemical, vascular and immune changes occurring in the endometrial stroma in response to the implanting embryo or even before conception and involves the stromal cells of the endometrium. It is a fundamental reproductive event occurring in mammalian species with hemochorial placentation. A growing body of experimental and clinical evidence strongly suggests that defective or disrupted decidualization contributes to the establishment of an inappropriate maternal-fetal interface. This has relevant clinical consequences, ranging from recurrent implantation failure and recurrent pregnancy loss in early pregnancy to several significant complications of advanced gestation. Moreover, recent evidence indicates that selected diseases of the endometrium, such as chronic endometritis and endometriosis, can have a detrimental impact on the decidualization response in the endometrium and may help explain some aspects of the reduced reproductive outcome associated with these conditions. Further research efforts are needed to fully understand the biomolecular mechanisms ans events underlying an abnormal decidualization response. This will permit the development of new diagnostic and therapeutic strategies aimed to improve the likelihood of achieveing a successful pregnancy.

MicroRNA-342 Promotes the Malignant-Like Phenotype of Endometrial Stromal Cells via Regulation of Annexin A2

The relevance of miRNA- (miR-) 342 to endometriosis has been highlighted, while its function in regulating the malignant-like phenotype of endometrial stromal cells which demonstrate epigenetic abnormalities that alter expression of transcription factors, remains unclear. Therefore, we sought to characterize the effects of miR-342 in endometrial stromal cell proliferation by regulating Annexin A2 (ANXA2). We first characterized the levels of miR-342 and ANXA2 in 31 cases of normal endometrium from patients with grade II-III cervical intraepithelial neoplasia or patients with hysterectomy versus ectopic endometrial tissues of 42 patients with endometriosis. miR-342 was upregulated, while ANXA2 was downregulated in ectopic endometrial tissues. Bioinformatics website and dual-luciferase reporter assay revealed that miR-342 negatively modulated ANXA2 expression. Following loss- and gain-of-function approaches, CCK-8, Transwell, and flow cytometry demonstrated that overexpression of miR-342 markedly increased cell proliferation, migration, and invasion but inhibited cell apoptotic ratio of endometrial stromal cells, which was reversed by ANXA2 elevation. Further, overexpressed miR-342 activated the PI3K/AKT/mTOR signaling pathway, as evidenced by upregulated levels of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. Taken together, miR-342 targets ANXA2 to activate the PI3K/AKT/mTOR signaling pathway, thereby promoting the malignant-like phenotype of endometrial stromal cells, highlighting miR-342 inhibition as a promising approach for the treatment of endometriosis.

Dysfunction of Decidual Macrophages Is a Potential Risk Factor in the Occurrence of Preeclampsia

Preeclampsia is a multi-factorial and multi-genetic disorder that affects more than eight million mother and baby pairs each year. Currently, most of the attention to the pathogenesis of preeclampsia has been focused on placenta, but recent progresses suggest that excellent decidualization lays foundation for placentation and growth. Moreover, preeclampsia is associated with an imbalance in immunoregulatory mechanisms, however, how the immune regulatory system in the decidua affects preeclampsia is still unclear. In our study, after intersecting the genes of differentially expressed between preeclampsia and the control gotten by conventional expression profile analysis and the genes contained in the ligand receptor network, we found eight differentially expressed genes in a ligand-receptor relationship, and the eight genes have a characteristic: most of them participate in the interaction between decidual macrophages and other decidual immune cells. The results of single-cell sequencing of decidual cells further demonstrated that decidual macrophages affect the functions of other immune cells through export. As a result, abnormal gene expression affects the export function of decidual macrophages, which in turn affects the interaction of decidual macrophages with other immune cells, thereby destroying the original immune regulation mechanism, and ultimately leading to the occurrence of preeclampsia.

Impaired decidualization of human endometrial stromal cells from women with adenomyosis†

Differentiation of endometrial stromal cells (ESCs) into secretory decidualized cells (dESCs) is essential for embryo implantation. Adenomyosis is a common benign gynecological disease that causes infertility. However, whether adenomyosis affects decidualization of human ESCs is elusive. Primary eutopic ESCs were obtained from patients with adenomyosis (n = 9) and women with nonendometrial diseases (n = 12). We determined the capacity of decidualization of human ESCs by qRT-PCR, Edu proliferation assay, cytokine array, and ELISA assay. We found that the expression of decidualization markers (IGFBP1 and PRL) in ESCs of adenomyosis was reduced, concomitant with increased cell proliferation. Differential secretion of cytokines in dESCs, including CXCL1/2/3, IL-6, IL-8, MCP-1, VEGF-A, MIP-3α, OPN, SDF-1α, HGF, and MMP-9, was observed between adenomyosis and nonadenomyosis. Moreover, the expression of decidualization regulators (HOXA10 at both mRNA and protein levels, FOXO1, KLF5, CEBPB, and HAND2 at mRNA levels) in the eutopic endometrium of adenomyosis was lower than that of nonadenomyosis. We propose that ESCs from adenomyosis have defected ability to full decidualization, which may lead to a nonreceptive endometrium.

Usp22 is expressed in mouse uterus during early pregnancy and involved in endometrial stromal cell decidualization

While decidualization is essential for embryo implantation in the context of a normal pregnancy, the molecular basis for this process remains poorly understood. Ubiquitin-specific protease 22 (Usp22), one of the deubiquitinating enzymes, is an important regulator of tumor progression and knocking out this gene in mice results in placental vascular dysplasia and embryonic lethality. In this study, we first demonstrated that Usp22 is spatiotemporally expressed in the mouse peri-implantation uterus. Under artificial decidualization, Usp22 upregulation was detected in both in vivo and in vitro. Progesterone treatment could stimulate Usp22 expression in mouse endometrial stromal cells through progesterone/progesterone receptor (PR) pathway, which is inhibited by PR antagonist. The downregulation of Usp22 within mouse endometrial stomal cells by shRNA impaired their ability to proliferate and undergo decidualization. Taken together, these results suggest that Usp22 is involved in uterine stromal decidualization in mice.

Annexin Animal Models-From Fundamental Principles to Translational Research

Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca²⁺)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.

Overexpression of LVRN impedes the invasion of trophoblasts by inhibiting epithelial-mesenchymal transition

Laeverin (LVRN) was first detected on the outer layer of the chorion laeve and migrating extravillous trophoblasts (EVTs). It is an enzyme that plays an important role in the placentation and pathophysiology of preeclampsia (PE). Previous studies have indicated that LVRN may be required for the invasion of human trophoblast cells. Paradoxically, LVRN was found to be highly expressed in the trophoblasts of PE patients with impaired invasive capacities. In this study, we detected the expression of LVRN in the placentas of PE patients (n=5) and normal term pregnancy women (n=5) as a control group by immunohistochemistry. LVRN was elevated in decidua (P=0.0083) and villi (P=0.0079) of PE patients. Next, LVRN was overexpressed via adeno-associated virus-mediated gene transfer in trophoblastic cell lines HTR8, Swan71, and JAR. Matrigel transwell assay and wound healing assay showed that overexpression of LVRN impeded the invasion of these three cell lines. Western blot analysis showed that LVRN overexpression caused downregulation of N-cadherin and vimentin and upregulation of E-cadherin, suggesting the inhibitory role of LVRN in epithelial-mesenchymal transition (EMT). Moreover, our data indicated that long noncoding RNA NONSTAT103348 (lnc10-7) was elevated in PE patients. Silencing lnc10-7 led to decreased LVRN expression. Taken together, although the basal level of LVRN may be crucial for cell invasion, overexpression of LVRN may abrogate the cell invasiveness, suggesting a multifaceted role of LVRN in the pathogenesis of PE.

Endometrial Decidualization: The Primary Driver of Pregnancy Health

Interventions to prevent pregnancy complications have been largely unsuccessful. We suggest this is because the foundation for a healthy pregnancy is laid prior to the establishment of the pregnancy at the time of endometrial decidualization. Humans are one of only a few mammalian viviparous species in which decidualization begins during the latter half of each menstrual cycle and is therefore independent of the conceptus. Failure to adequately prepare (decidualize) the endometrium hormonally, biochemically, and immunologically in anticipation of the approaching blastocyst—including the downregulation of genes involved in the pro- inflammatory response and resisting tissue invasion along with the increased expression of genes that promote angiogenesis, foster immune tolerance, and facilitate tissue invasion—leads to abnormal implantation/placentation and ultimately to adverse pregnancy outcome. We hypothesize, therefore, that the primary driver of pregnancy health is the quality of the soil, not the seed.

Perfluoroalkyl substances in early pregnancy and risk of hypertensive disorders of pregnancy: A prospective cohort study

BACKGROUND

Perfluoroalkyl substances (PFASs) were reported to be associated with hypertensive disorders of pregnancy (HDP) but the results were inconsistent and prospective data are scarce. We aimed to examine these associations in a large prospective birth cohort study in Shanghai, China.

METHODS

A total of 10 PFASs were measured by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS-MS) in the plasma samples from 3220 women who were enrolled during early pregnancy and gave birth to a singleton live birth between 2013 and 2016. The outcomes included gestational hypertension (GH), preeclampsia (PE) and overall HDP. Associations of these outcomes with each PFASs were estimated by multivariable logistic regression and expressed as odd ratios (ORs) and 95% confidence intervals (95% CIs). Potential non-linear association between PFASs and HDP was examined with restricted cubic spline model. To handle the potential confounding by correlated PFASs, we applied elastic net regression (ENR) to identify independent PFASs components of outcomes.

RESULTS

Among all singleton live births, the incidence rates of GH and PE were 2.0% and 2.2%, respectively. Overall, PFASs did not show a significant and consistent pattern of the associations with GH, PE or overall HDP, both before and after controlling for potential confounders. ENR model confirmed the results that there was no independently predictive role of PFASs on GH, PE or overall HDP.

CONCLUSIONS

In this large prospective cohort study, maternal plasma concentration of PFASs in early pregnancy were not associated with GH, PE or overall HDP in singleton livebirths.