Matrix metalloproteinase-9 deficiency phenocopies features of preeclampsia and intrauterine growth restriction

The transcriptional repressor Blimp1/PRDM1 regulates the maternal decidual response in mice

The transcriptional repressor Blimp1 controls cell fate decisions in the developing embryo and adult tissues. Here we describe Blimp1 expression and functional requirements within maternal uterine tissues during pregnancy. Expression is robustly up-regulated at early post-implantation stages in the primary decidual zone (PDZ) surrounding the embryo. Conditional inactivation results in defective formation of the PDZ barrier and abnormal trophectoderm invasion. RNA-Seq analysis demonstrates down-regulated expression of genes involved in cell adhesion and markers of decidualisation. In contrast, genes controlling immune responses including IFNγ are up-regulated. ChIP-Seq experiments identify candidate targets unique to the decidua as well as those shared across diverse cell types including a highly conserved peak at the Csf-1 gene promoter. Interestingly Blimp1 inactivation results in up-regulated Csf1 expression and macrophage recruitment into maternal decidual tissues. These results identify Blimp1 as a critical regulator of tissue remodelling and maternal tolerance during early stages of pregnancy.

Differential processing of high-molecular-weight kininogen during normal pregnancy

RATIONALE

Studies identified kininogen as a potential biomarker of preeclampsia, a major cause of adverse maternal outcomes. High-molecular-weight kininogen (HK) and its activated form participate in numerous pathways associated with establishing and maintaining pregnancy. However, dynamic changes in HK and naturally occurring HK-derived peptides during the natural course of pregnancy are largely unknown.

METHODS

Longitudinal serum samples during the course of normal pregnancy (trimesters T1, T2, T3) from 60 pregnant women were analyzed by western blot with an anti-HK antibody. Circulating peptides in longitudinal serum specimens derived from 50 participants were enriched using nanoporous silica thin films. Peptides were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS) and database searching. Relative quantification was performed using MaxQuant and in-house scripts. Normality was evaluated by either ANOVA or Friedman tests with p < 0.05 for statistical significance.

RESULTS

Western blotting revealed that HK significantly decreased during normal pregnancy (T1 vs T2, p < 0.05; T1 vs T3, p < 0.0001). A 100 kDa intermediate increased during pregnancy (T1 vs T2, p < 0.005; T1 vs T3, p < 0.01). Moreover, the heavy chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.01) and light chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.05) significantly increased during pregnancy. LC/MS/MS analysis identified 180 kininogen-1 peptides, of which 167 mapped to domain 5 (D5). Seventy-three peptides with ten or more complete data sets were included for further analysis. Seventy peptides mapped to D5, and 3, 24, and 43 peptides showed significant decrease, no trend, and significant increase, respectively, during pregnancy.

CONCLUSIONS

This study demonstrates dynamic changes in HK and naturally occurring HK-derived peptides during pregnancy. Our study sheds light on the gestational changes of HK and its peptides for further validation of them as potential biomarkers for pregnancy-related complications.

Development of placental abnormalities in location and anatomy

Low‐lying placentas, placenta previa and abnormally invasive placentas are the most frequently occurring placental abnormalities in location and anatomy. These conditions can have serious consequences for mother and fetus mainly due to excessive blood loss before, during or after delivery. The incidence of such abnormalities is increasing, but treatment options and preventive strategies are limited. Therefore, it is crucial to understand the etiology of placental abnormalities in location and anatomy. Placental formation already starts at implantation and therefore disorders during implantation may cause these abnormalities. Understanding of the normal placental structure and development is essential to comprehend the etiology of placental abnormalities in location and anatomy, to diagnose the affected women and to guide future research for treatment and preventive strategies. We reviewed the literature on the structure and development of the normal placenta and the placental development resulting in low‐lying placentas, placenta previa and abnormally invasive placentas.

Gut Microbiota Dysbiosis and Increased Plasma LPS and TMAO Levels in Patients With Preeclampsia

Objective: To characterize the gut microbiota in patients with preeclampsia (PE) compared with healthy controls.

Methods: We analyzed and compared the microbiota communities in the feces of 48 PE patients with 48 age-, gestational weeks-, and pre-pregnancy body mass index-matched healthy controls using 16S rRNA gene sequencing, and also we tested fecal and plasma lipopolysaccharide (LPS) and plasma trimethylamine-N-oxide (TMAO) concentration levels in the two groups.

Results: Compared with the control group, microbial alpha diversity was lower in the PE group, but there was no statistically significant difference between the two groups. At the phylum level, Firmicutes (51.64% PE vs. 59.62% Control, P < 0.05), Bacteroidetes (40.51% PE vs. 34.81% Control, P< 0.05), Proteobacteria (4.51% PE vs. 2.56% Control, P < 0.05), and Actinobacteria (2.90% PE vs. 1.77% Control, P < 0.05), exhibited significant differences between the PE group and the control group. LEfSe analysis found 17 differentially abundant taxa between the two groups. PICRUSt analysis found that in the KEGG pathways, the microbial gene functions related to LPS biosynthesis were higher in the fecal microbiome of the PE group. The fecal and plasma LPS concentrations and plasma TMAO concentrations of PE patients were higher than those of the healthy controls.

Conclusion: PE patients had gut microbiota dysbiosis and increased plasma LPS and TMAO levels, which will lead to a better understanding of the relationship between the gut microbiota and PE.

Involvement of p38 MAPK pathway in benzo(a)pyrene-induced human hepatoma cell migration and invasion

The objective of this study was to investigate the potential role of p38 mitogen-activated protein kinases (MAPK) in benzo(a)pyrene (BaP)-induced hepatoma cell migration and invasion. Western blot assay was applied to detect the expression of proteins. qRT-PCR assay was used to measure the expression of mRNA. Wound healing assay and Transwell invasion assay were performed to evaluate cell migratory ability and cell invasive ability, respectively. Our data showed that BaP exposure increased the expression of p-p38 protein in human hepatoma HepG2 cells. Exposure to BaP facilitated HepG2 cell migration and invasion, which could be blocked by p38 MAPK inhibitors. In addition, BaP exposure induced upregulation of MMP9 mRNA expression, which was modulated by p-p38. In conclusion, p38 MAPK pathway was involved in BaP-induced hepatoma cell migration and invasion.

RITA Is Expressed in Trophoblastic Cells and Is Involved in Differentiation Processes of the Placenta

Preeclampsia (PE) remains a leading cause of maternal and perinatal mortality and morbidity worldwide. Its pathogenesis has not been fully elucidated and no causal therapy is currently available. It is of clinical relevance to decipher novel molecular biomarkers. RITA (RBP-J (recombination signal binding protein J)-interacting and tubulin-associated protein) has been identified as a negative modulator of the Notch pathway and as a microtubule-associated protein important for cell migration and invasion. In the present work, we have systematically studied RITA’s expression in primary placental tissues from patients with early- and late-onset PE as well as in various trophoblastic cell lines. RITA is expressed in primary placental tissues throughout gestation, especially in proliferative villous cytotrophoblasts, in the terminally differentiated syncytiotrophoblast, and in migrating extravillous trophoblasts. RITA’s messenger RNA (mRNA) level is decreased in primary tissue samples from early-onset PE patients. The deficiency of RITA impairs the motility and invasion capacity of trophoblastic cell lines, and compromises the fusion ability of trophoblast-derived choriocarcinoma cells. These data suggest that RITA may play important roles in the development of the placenta and possibly in the pathogenesis of PE.

MicroRNAs in Uteroplacental Vascular Dysfunction

Pregnancy complications of preeclampsia and intrauterine growth restriction (IUGR) are major causes of maternal and perinatal/neonatal morbidity and mortality. Although their etiologies remain elusive, it is generally accepted that they are secondary to placental insufficiency conferred by both failure in spiral artery remodeling and uteroplacental vascular malfunction. MicroRNAs (miRNAs) are small no-coding RNA molecules that regulate gene expression at the post-transcriptional level. Increasing evidence suggests that miRNAs participate in virtually all biological processes and are involved in numerous human diseases. Differentially expressed miRNAs in the placenta are typical features of both preeclampsia and IUGR. Dysregulated miRNAs target genes of various signaling pathways in uteroplacental tissues, contributing to the development of both complications. In this review, we provide an overview of how aberrant miRNA expression in preeclampsia and IUGR impacts the expression of genes involved in trophoblast invasion and uteroplacental vascular adaptation.

Molecular pathways of senescence regulate placental structure and function

The placenta is an autonomous organ that maintains fetal growth and development. Its multinucleated syncytiotrophoblast layer, providing fetal nourishment during gestation, exhibits characteristics of cellular senescence. We show that in human placentas from pregnancies with intrauterine growth restriction, these characteristics are decreased. To elucidate the functions of pathways regulating senescence in syncytiotrophoblast, we used dynamic contrast-enhanced MRI in mice with attenuated senescence programs. This approach revealed an altered dynamics in placentas of p53-/- , Cdkn2a-/- , and Cdkn2a-/- ;p53-/- mice, accompanied by histopathological changes in placental labyrinths. Human primary syncytiotrophoblast upregulated senescence markers and molecular pathways associated with cell-cycle inhibition and senescence-associated secretory phenotype. The pathways and components of the secretory phenotype were compromised in mouse placentas with attenuated senescence and in human placentas from pregnancies with intrauterine growth restriction. We propose that molecular mediators of senescence regulate placental structure and function, through both cell-autonomous and non-autonomous mechanisms.

Kisspeptin as a potential biomarker throughout pregnancy

Kisspeptins are a family of neuropeptides that are critical for the puberty initiation and female fertility. Plasma or serum kisspeptin is mainly derived from the placenta during pregnancy and plasma kisspeptin levels significantly increase across pregnancy. Plasma kisspeptin levels could be used as a potential biomarker for the detection of miscarriage, pre-eclampsia, gestational trophoblastic neoplasia (GTN), and fetal development. Kisspeptin may also be involved in the process of parturition by stimulating oxytocin secretion during term pregnancy. This review discussed the potential use of kisspeptin as a marker across pregnancy and highlighted the unresolved problems in this area. Tweetable abstract: Plasma kisspeptin levels could be used as a potential biomarker across pregnancy.

Gene expression analysis of MMPs in women with preeclampsia using cell-free fetal RNA in maternal plasma

OBJECTIVE

Nucleic acids released from the placenta into the mother's blood circulation system provide a valuable source of potential biomarkers for early detection of pregnancy complications such as preeclampsia (PE). PE affects nearly 5-10% of pregnancies worldwide and is a major contributor to the maternal and neonatal mortality and morbidity. It is known that altered placental expression of matrix metalloproteinases (MMPs) may cause shallow cytotrophoblastic invasion and ultimately lead to preeclampsia. The present study aimed to evaluate pattern of placental/fetal expression of the MMP family (MMP-2, MMP-9, MMP-14, MMP-15 and MMP-26) in preeclamptic women and compare it to normal pregnancies, using cell free fetal RNA (cff-RNA).

METHODS

Blood samples were obtained from 20 pregnant women diagnosed with severe PE (28-32 weeks) and 40 control healthy pregnant women in two groups of either matched gestational age (N = 20) or 14 and 28 weeks pregnancies (each 10). cff-RNA was extracted from plasma, followed by reverse transcription of cff-RNA. Expression of MMP genes was measured using quantitative reverse transcription PCR (qRT-PCR).

RESULTS

The expression levels of MMP-2, MMP-9 and MMP-15 were significantly increased, while MMP-14 expression level was significantly reduced and the expression of MMP-26 showed a relative increase in PE pregnancies compared to the control group. Additionally, increased level of MMPs expression was observed by comparing 14 and 28 weeks gestation age in normal pregnancy.

CONCLUSION

Using cff-RNA, circulatory expression level of MMP-2, MMP-9, MMP-14 and MMP-15 were significantly altered in preeclampsia compared to normal pregnancies.

Lvrn expression is not critical for mouse placentation

Preeclampsia is a systemic disease caused by abnormal placentation that affects both mother and fetus. It was reported that Laeverin (LVRN, also known as Aminopeptidase Q) was up-regulated in the placenta of preeclamptic patients. However, physiological and pathological functions of LVRN remained to be unknown. Here we characterized Lvrn function during placentation in mice. RT-PCR showed that Lvrn is expressed in both fetus and placenta during embryogenesis, and several adult tissues. When we overexpressed Lvrn in a placenta-specific manner using lentiviral vectors, we did not see any defects in both placentae and fetuses. The mice carrying Lvrn overexpressing placentas did not show any preeclampsia-like symptoms such as maternal high blood pressure and fetal growth restriction. We next ablated Lvrn by CRISPR/Cas9-mediated genome editing to see physiological function. In Lvrn ablated mice, maternal blood pressure during pregnancy was not affected, and both placentas and fetuses grew normally. Collectively, these results suggest that, LVRN is irrelevant to preeclampsia and dispensable for normal placentation and embryonic development in mice.

Transcriptomic analysis of the interaction of choriocarcinoma spheroids with receptive vs. non-receptive endometrial epithelium cell lines: an in vitro model for human implantation

PURPOSE

Several in vitro systems have been reported to model human implantation; however, the molecular dynamics of the trophoblast vs. the epithelial substrate during attachment have not been described. We have established an in vitro model which allowed us to dissect the transcriptional responses of the trophoblast and the receptive vs. non-receptive epithelium after co-culture.

METHODS

We established an in vitro system based on co-culture of (a) immortalized cells representing receptive (Ishikawa) or non-receptive (HEC-1-A) endometrial epithelium with (b) spheroids of a trophoblastic cell line (JEG-3) modified to express green fluorescent protein (GFP). After 48 h of co-culture, GFP+ (trophoblast cells) and GFP- cell fractions (receptive or non-receptive epithelial cells) were isolated by fluorescence-activated flow cytometry (FACS) and subjected to RNA-seq profiling and gene set enrichment analysis (GSEA).

RESULTS

Compared to HEC-1-A, the trophoblast challenge to Ishikawa cells differentially regulated the expression of 495 genes, which mainly involved cell adhesion and extracellular matrix (ECM) molecules. GSEA revealed enrichment of pathways related to cell division, cell cycle regulation, and metabolism in the Ishikawa substrate. Comparing the gene expression profile of trophoblast spheroids revealed that 1877 and 323 genes were upregulated or downregulated when co-cultured on Ishikawa substrates (compared to HEC-1-A), respectively. Pathways favorable to development, including tissue remodeling, organogenesis, and angiogenesis, were enhanced in the trophoblast compartment after co-culture of spheroids with receptive epithelium. By contrast, the co-culture with less receptive epithelium enriched pathways mainly related to trophoblast cell proliferation and cell cycle regulation.

CONCLUSIONS

Endometrial receptivity requires a transcriptional signature that determines the trophoblast response and drives attachment.

Role of proteases in dysfunctional placental vascular remodelling in preeclampsia

Preeclampsia is a syndrome characterised by vascular dysfunction, impaired angiogenesis, and hypertension during pregnancy. Even when the precise pathophysiology of preeclampsia remains elusive, impaired vascular remodelling and placental angiogenesis in the placental villi and defective trophoblast invasion of the uterus are proposed as crucial mechanisms in this syndrome. Reduced trophoblast invasion leads to reduced uteroplacental blood flow and oxygen availability and increased oxidative stress. These phenomena trigger the release of soluble factors into the maternal and foetoplacental circulation that are responsible of the clinical features of preeclampsia. New blood vessels generation as well as vascular remodelling are mechanisms that require expression and activity of different proteases, including matrix metalloproteases, a-disintegrin and metalloproteases, and a-disintegrin and metalloprotease with thrombospondin motifs. These proteases exert proteolysis of the extracellular matrix. Additionally, cathepsins, a family of proteolytic enzymes, are primarily located in lysosomes but are also released by cells to the extracellular space. This review focuses on the role that these proteases play in the regulation of the uterine trophoblast invasion and the placental vascular remodelling associated with preeclampsia.

Differences in Brain-Derived Neurotrophic Factor and Matrix Metalloproteinase-9 between Appropriate Neonates between Normal Birth Weight and Intrauterine Growth Restriction

BACKGROUND:

Intrauterine Growth Restriction (IUGR) was defined as the growth of the fetus less than its normal potential growth due to genetic and environmental factors. One of the most widely believed causes of IUGR was impaired uteroplacental mechanism from mother to fetus. Furthermore, factor which was thought to affect placental growth was due to the influence of Brain-Derived Neurotrophic Factor (BDNF) and Matrix Metalloproteinase (MMP-9) which play an important role in angiogenesis.

AIM:

This study aims to determine differences in Brain-Derived Neurotrophic Factor (BDNF) and moderately mature Matrix Metalloproteinase (MMP-9) between normal birth weight and intrauterine growth restriction.

MATERIAL AND METHODS:

The study design was a cross-sectional study at four hospitals in Padang city from August 2017-January 2018. The sample of this study was umbilical cord blood of appropriate gestational age neonate with normal birth weight (31 neonates) and IUGR (31 neonates) by consecutive sampling, samples taken from mothers who meet inclusion criteria. BDNF and MMP-9 levels were analysed by ELISA. The differences between normal birth weight and IUGR test were followed by unpaired T-test.

RESULTS:

The results showed that BDNF levels in normal neonates was 1.58 ± 0.23 ng/ml and in IUGR neonates were 1.25 ± 0.35 ng/ml (p = 0.001). MMP-9 levels in normal neonates was 1.09 ± 0.20 ng/ml and in IUGR neonates were 1.25 ± 0.35 (p = 0.03).

CONCLUSION:

The conclusion of this study was BDNF of moderately mature neonates was significantly higher in normal birth weight compared to intrauterine growth restriction, and the moderately high MMP-9 neonates were significantly higher in intrauterine growth restriction compared with normal birth weight.

Trophoblastic proliferation and invasion regulated by ACTN4 is impaired in early onset preeclampsia

Successful pregnancy requires normal placentation, which largely depends on the tight regulation of proliferation, invasion, and migration of trophoblast cells. Abnormal functioning of trophoblast cells may cause failure of uterine spiral artery remodeling, which may be related to pregnancy-related disorders, such as preeclampsia. Here, we reported that an actin-binding protein, α-actinin (ACTN)4, was dysregulated in placentas from early onset preeclampsia. Moreover, knockdown of ACTN4 markedly inhibited trophoblast cell proliferation by reducing AKT membrane translocation. Furthermore, E-cadherin regulated ACTN4 and β-catenin colocalization on trophoblast cell podosomes, and ACTN4 down-regulation suppressed the E-cadherin-induced cell invasion increase via depolymerizing actin filaments. Moreover, loss of ACTN4 recapitulated a number of the features of human preeclampsia. Therefore, our data indicate that ACNT4 plays a role in trophoblast function and is required for normal placental development.-Peng, W., Tong, C., Li, L., Huang, C., Ran, Y., Chen, X., Bai, Y., Liu, Y., Zhao, J., Tan, B., Luo, X., Wang, H., Wen, L., Zhang, C., Zhang, H., Ding, Y., Qi, H., Baker, P. N. Trophoblastic proliferation and invasion regulated by ACTN4 is impaired in early onset preeclampsia.

Propeptide glycosylation and galectin-3 binding decrease proteolytic activation of human proMMP-9/progelatinase B

Matrix metalloproteinases (MMPs) are secreted as proenzymes, containing propeptides that interact with the catalytic zinc, thereby controlling MMP activation. The MMP‐9 propeptide is unique in the MMP family because of its post‐translational modification with an N‐linked oligosaccharide. ProMMP‐9 activation by MMP‐3 occurs stepwise by cleavage of the propeptide in an aminoterminal (pro‐AT) and carboxyterminal (pro‐CT) peptide. We chemically synthesized aglycosyl pro‐AT and pro‐CT and purified recombinant glycosylated pro‐AT^Sf−9. First, we report new cleavage sites in the MMP‐9 propeptide by MMP‐3 and neutrophil elastase. Additionally, we demonstrated with the use of western blot analysis a higher resistance of glycosylated versus aglycosyl pro‐AT against proteolysis by MMP‐3, MMP‐9, meprin α, neutrophil elastase and by protease‐rich synovial fluids from rheumatoid arthritis patients. Moreover, we investigated the effect of glycosylation on proteolytic activation of human proMMP‐9 with the use of zymography and dye‐quenched gelatin cleavage analysis. Compared to recombinant Sf‐9 proMMP‐9 glycoforms, larger oligosaccharides of human neutrophil proMMP‐9 increased resistance against proteolytic activation. Additionally, proMMP‐9 from Congenital Disorder of Glycosylation patients, compared to healthy controls, showed a higher activation rate by MMP‐3. Finally, we demonstrated that glycan‐galectin‐3 interactions reduced proMMP‐9 activation. In conclusion, modification of MMP‐9 propeptide glycosylation is a fine‐tuning mechanism and co‐determines the specific activity of MMP‐9 in physiology and pathology.

Enzymes

MMP‐9 EC 3.4.24.35, MMP‐3 EC 3.4.24.17, meprin α EC 3.4.24.18, neutrophil elastase EC 3.4.21.37, trypsin EC 3.4.21.4 and PNGase F EC 3.5.1.52.

Total flavonoids from Semen Cuscutae target MMP9 and promote invasion of EVT cells via Notch/AKT/MAPK signaling pathways

Miscarriage is a common condition during pregnancy and its mechanisms remain largely unknown. Extravillous trophoblast (EVT) cell invasion is required to maintain normal pregnancy and its malfunction has been proposed as a major cause for miscarriage. Homeostasis of matrix metalloproteinase 9 (MMP9) is a key to regulate EVT cell invasion. Total flavonoids from Semen Cuscutae (TFSC) have been applied clinically used for preventing or treating miscarriage in the past. Given its potential clinical benefit on preventing miscarriage, this study aims at examining the therapeutic effect of TFSC in the prevention of premature birth by upregulating MMP9 and promote EVT cell invasion. HTR-8 cells migration and invasion functions were analyzed using wound healing and transwell assays. The regulatory effect of TFSC on MMP9 expression and relevant signaling pathways were analyzed by Western Blot. The results show compared to control group, TFSC significantly promoted the migration of EVT cells in a dose and time-dependent manner. The migration and invasion of EVT cells were maximized at the highest dosage of 5 μg/ml of TFSC. The expression of MMP9 in EVT cells was significantly increased after TFSC treatment. Furthermore, cells treated with TFSC significantly upregulated protein expressions in Notch, AKT and p38/MAPK signaling pathways. We believe TFSC can promote the migration and invasion of EVT cells by increasing MMP9 expression, and prevent miscarriage by activating Notch, AKT, and MAPK signaling pathways.

Molecular determinants of microvascular dysfunction in hypertensive pregnancy and preeclampsia

Preeclampsia is a pregnancy-related disorder characterized by hypertension and often fetal intrauterine growth restriction, but the underlying mechanisms are unclear. Defective placentation and apoptosis of invasive cytotrophoblasts cause inadequate remodeling of spiral arteries, placental ischemia, and reduced uterine perfusion pressure (RUPP). RUPP causes imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic vascular endothelial growth factor and placental growth factor, and stimulates the release of proinflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors target the vascular endothelium, smooth muscle and various components of the extracellular matrix. Generalized endotheliosis in systemic, renal, cerebral, and hepatic vessels causes decreases in endothelium-derived vasodilators such as nitric oxide, prostacyclin and hyperpolarization factor, and increases in vasoconstrictors such as endothelin-1 and thromboxane A2. Enhanced mechanisms of vascular smooth muscle contraction, such as intracellular Ca2+ , protein kinase C, and Rho-kinase cause further increases in vasoconstriction. Changes in matrix metalloproteinases and extracellular matrix cause inadequate vascular remodeling and increased arterial stiffening, leading to further increases in vascular resistance and hypertension. Therapeutic options are currently limited, but understanding the molecular determinants of microvascular dysfunction could help in the design of new approaches for the prediction and management of preeclampsia.

Murine transcription factor Math6 is a regulator of placenta development

The murine basic helix-loop-helix transcription (bHLH) factor mouse atonal homolog 6 (Math6) is expressed in numerous organs and supposed to be involved in several developmental processes. However, so far neither all aspects nor the molecular mechanisms of Math6 function have been explored exhaustively. To analyze the in vivo function of Math6 in detail, we generated a constitutive knockout (KO) mouse (Math6^−/−) and performed an initial histological and molecular biological investigation of its main phenotype. Pregnant Math6^−/− females suffer from a disturbed early placental development leading to the death of the majority of embryos independent of the embryonic Math6 genotype. A few placentas and fetuses survive the severe uterine hemorrhagic events at late mid-gestation (E13.5) and subsequently develop regularly. However, these fetuses could not be born due to obstructions within the gravid uterus, which hinder the birth process. Characterization of the endogenous spatiotemporal Math6 expression during placenta development reveals that Math6 is essential for an ordered decidualization and an important regulator of the maternal-fetal endocrine crosstalk regulating endometrial trophoblast invasion and differentiation. The strongly disturbed vascularization observed in the maternal placenta appears as an additional consequence of the altered endocrine status and as the main cause for the general hemorrhagic crisis.

The Notch Family Transcription Factor, RBPJκ, Modulates Glucose Transporter and Ovarian Steroid Hormone Receptor Expression During Decidualization

During decidualization, endometrial stromal cells differentiate into a secretory phenotype to modulate the uterine microenvironment and promote embryo implantation. This highly metabolic process relies on ovarian steroid receptors and glucose transporters. Canonical Notch signaling is mediated by the transcription factor Recombination Signal Binding Protein for Immunoglobulin Kappa J Region (RBPJ). Loss of RBPJ in the mouse uterus (Pgr^cre/+Rbpj^flox/flox; Rbpj c-KO) results in subfertility in part due to an abnormal uterine-embryonic axis during implantation and, as described herein, decidualization failure. Induced in vivo decidualization in Rbpj c-KO mice was impaired with the downregulation of decidual markers and decreased progesterone receptor (Pgr) signaling. Consistent with in vivo mouse data, RBPJ knockdown during in vitro Human uterine fibroblast (HuF) cell decidualization results in the reduced expression of decidual marker genes along with PGR. Expression of the glucose transporter, SLC2A1, was decreased in the RBPJ-silenced HuF cells, which corresponded to decreased Slc2a1 in the secondary decidual zone of Rbpj c-KO mouse uteri. Exogenous administration of pyruvate, which bypasses the need for glucose, rescues PRL expression in RBPJ-deficient HuF cells. In summary, Notch signaling through RBPJ controls both ovarian steroid receptor PGR and glucose transporter SLC2A1 expression during decidualization, and this dysregulation likely contributes to embryo implantation failure.

Trophoblast VIP deficiency entails immune homeostasis loss and adverse pregnancy outcome in mice

Immune homeostasis maintenance throughout pregnancy is critical for normal fetal development. Trophoblast cells differentiate into an invasive phenotype and contribute to the transformation of maternal arteries and the functional shaping of decidual leukocyte populations. Insufficient trophoblast invasion, inadequate vascular remodeling, and a loss of immunologic homeostasis are associated with pregnancy complications, such as preeclampsia and intrauterine growth restriction. Vasoactive intestinal peptide (VIP) is a pleiotropic neuropeptide synthetized in trophoblasts at the maternal-placental interface. It regulates the function of trophoblast cells and their interaction with decidual leukocytes. By means of a murine model of pregnancy in normal maternal background with VIP-deficient trophoblast cells, here we demonstrate that trophoblast VIP is critical for trophoblast function: VIP gene haploinsufficiency results in lower matrix metalloproteinase 9 expression, and reduced migration and invasion capacities. A reduced number of regulatory T cells at the implantation sites along with a lower expression of proangiogenic and antiinflammatory markers were also observed. Findings detected in the implantation sites at early stages were followed by an abnormal placental structure and lower fetal weight. This effect was overcome by VIP treatment of the early pregnant mice. Our results support the relevance of trophoblast-synthesized VIP as a critical factor in vivo for trophoblast-cell function and immune homeostasis maintenance in mouse pregnancy.-Hauk, V., Vota, D., Gallino, L., Calo, G., Paparini, D., Merech, F., Ochoa, F., Zotta, E., Ramhorst, R., Waschek, J., Leirós, C. P. Trophoblast VIP deficiency entails immune homeostasis loss and adverse pregnancy outcome in mice.

PAPP-A2 deficiency does not exacerbate the phenotype of a mouse model of intrauterine growth restriction

BACKGROUND

Pregnancy-associated plasma protein-A2 (PAPP-A2) is consistently upregulated in the placentae of pregnancies complicated by preeclampsia and fetal growth restriction. The causes and significance of this upregulation remain unknown, but it has been hypothesized that it is a compensatory response to improve placental growth and development. We predicted that, if the upregulation of PAPP-A2 in pregnancy complications reflects a compensatory response, then deletion of Pappa2 in mice would exacerbate the effects of a gene deletion previously reported to impair placental development: deficiency of matrix metalloproteinase-9 (MMP9).

METHODS

We crossed mice carrying deletions in Pappa2 and Mmp9 to produce pregnancies deficient in one, both, or neither of these genes. We measured pregnancy rates, number of conceptuses, fetal and placental growth, and the histological structure of the placenta.

RESULTS

We found no evidence of reduced fertility, increased pregnancy loss, or increased fetal demise in Mmp9 ^-/- females. In pregnancies segregating for Mmp9, Mmp9 ^-/- fetuses were lighter than their siblings with a functional Mmp9 allele. However, deletion of Pappa2 did not exacerbate or reveal any effects of Mmp9 deficiency. We observed some effects of Pappa2 deletion on placental structure that were independent of Mmp9 deficiency, but no effects on fetal growth. At G16, male fetuses were heavier than female fetuses and had heavier placentae with larger junctional zones and smaller labyrinths.

CONCLUSIONS

Effects of Mmp9 deficiency were not exacerbated by the deletion of Pappa2. Our results do not provide evidence that upregulation of placental PAPP-A2 represents a mechanism to compensate for impaired fetal growth.

Ten-eleven translocation 2 demethylates the MMP9 promoter, and its down-regulation in preeclampsia impairs trophoblast migration and invasion

Preeclampsia is the most common clinical disorder in pregnancy and might result from disordered uterine environments caused by epigenetic modifications, including deregulation of DNA methylation/demethylation. Recent research has indicated that 5-hydroxymethylcytosine (5hmC), a DNA base derived from 5-methylcytosine (5mC) via oxidation by ten-eleven translocation (TET) enzymes, is involved in DNA methylation-related plasticity. Here, we report that TET2 expression and 5hmC abundance are significantly altered in the placentas from preeclampsia patients. shRNA-mediated TET2 knockdown (shTET2) reduced trophoblast migration and invasion when cultured in Matrigel. Both real-time PCR of matrix metalloproteinase (MMP)-related transcripts and a human angiogenesis antibody array indicated that TET2 knockdown in trophoblasts inhibits the expression of MMP transcript, of which MMP9 represented one of the most significant TET2 downstream targets. Using an established shTET2 HTR-8/SVneo cell model, we further confirmed alterations of 5hmC levels and MMP9 expression at both mRNA and protein levels. In particular, we found that TET2 bound to and removed 5mC modifications at the MMP9 promoter region. Interestingly, in TET2 knockdown cells, both MMP9 expression and the compromised trophoblast phenotype could be rescued by vitamin C, an activator of TET enzyme activity. Finally, TET2 expression correlated with MMP9 levels in placenta samples from the preeclampsia patients, indicating that TET2 deregulation is critically involved in the pathogenesis of preeclampsia through down-regulation of MMP9 expression. Our findings highlight a critical role of TET2 in regulating trophoblast cell migration through demethylation at the MMP9 promoter, and suggest that down-regulation of the TET2-MMP9-mediated pathway contributes to preeclampsia pathogenesis.

Celastrol attenuates symptoms of preeclampsia in rats by inhibiting matrix metalloproteinase-9

Preeclampsia is reported in pregnant women around the world and often causes maternal/fetal mortality and morbidity. In the current study, we assessed the efficacy of celastrol on a rat preeclampsia model induced by N^ω-nitro-L-arginine methyl ester hydrochloride (L-NAME). Pregnant rats were administered L-NAME to establish preeclampsia. A total of 48 animals were randomly assigned into 4 groups (n = 12 each): control, control plus celastrol treatment (control+celastrol), preeclampsia, and preeclampsia plus celastrol. Physiological parameters including total urine protein, urine volume and blood pressure were evaluated. Urinary messenger RNA (mRNA) levels of podocin and nephrin were determined using RT-PCR. Further, levels of serum placenta growth factor (PlGF), matrix metalloproteinase (MMP)-9 and renal renal soluble fms-like tyrosine kinase-1 (sFlt-1) were also measured. In rats with preeclampsia, there were robust increases in total urine protein, urine volume and blood pressure, which were significantly attenuated in rats treated with celastrol. Urinary mRNA levels of podocin and nephrin, as well as PlGF, MMP-9 and sFlt-1, were all reversed in preeclampsia plus celastrol group compared to rats in the preeclampsia group without celastrol treatments. MMP-9 overexpression in rats completely abolished the alleviating effect of celastrol. We hereby presented the first evidence that celastrol attenuated preeclampsia symptoms in an L-NAME-induced rat model of preeclampsia through inhibition of MMP-9 expression, supporting the potential therapeutic value of celastrol in the treatment of preeclampsia.

Causative Effects of Genetically Determined High Maternal/Fetal Endothelin-1 on Preeclampsia-Like Conditions in Mice

Endothelin-1 (ET-1) is implicated in the pathophysiology of preeclampsia. An association between an EDN1 gene polymorphism with high ET-1 and preeclampsia was reported in humans, but their cause and effect relationships have not been defined. We examined the pregnancy effects in mice with a modified Edn1 allele that increases mRNA stability and thus ET-1 production. Heterozygous Edn1^H/+ females showed no obvious abnormalities before pregnancy, but when mated with wild-type (WT) males developed a full spectrum of preeclampsia-like phenotypes, including increased systolic blood pressure, proteinuria, glomerular endotheliosis, and intrauterine fetal growth restriction. At 7.5 days post-coitus, the embryos from Edn1^H/+ dams, regardless of their Edn1 genotype, lagged 12 hours in development compared with embryos from WT dams, had disoriented ectoplacental cones, and retained high E-cadherin expression. In contrast, WT females mated with Edn1^H/+ males, which also carried half of the fetuses with Edn1^H/+ genotype, showed a mild systolic blood pressure increase only. These WT dams had 2× higher plasma soluble fms-like tyrosine kinase-1 than WT dams mated with WT males. In human first trimester trophoblast cells, pharmacological doses of ET-1 increased the cellular sFlt1 transcripts and protein secretion via both type A and B ET-1 receptors. Our data demonstrate that high maternal ET-1 production causes preeclampsia-like phenotypes during pregnancy, affecting both initial stage of trophoblast differentiation/invasion and maternal peripheral vasculature during late gestation. High fetal ET-1 production, however, could cause increased soluble fms-like tyrosine kinase-1 in the maternal circulation and contribute to blood pressure elevation.

Therapeutic effect of human umbilical cord-derived mesenchymal stem cells on injured rat endometrium during its chronic phase

BACKGROUND

Repair deficiency after endometrial injury is an important reason for intra-uterine adhesions, amenorrhea, and infertility in females. Bone marrow-derived mesenchymal stem cell (BMSC) transplantation is effective in repairing the damaged endometrium. However, the possibility of using umbilical cord-derived MSCs (UC-MSCs) to treat endometrial injury is rarely reported.

METHODS

Ethanol (95%) was injected into rat uterus to establish a model of endometrial injury. UC-MSCs were injected through the tail vein, either as a single, twice, or thrice administration. Functional restoration of the uterus was assessed by testing embryo implantation rates. Endometrial morphological alteration was observed by hematoxylin and eosin staining. Endometrial fibrosis, markers of epithelial and stromal cells of endometrium, cell proliferation and angiogenesis, and inflammatory factors were detected using immunohistochemistry, Western blotting, and quantitative reverse-transcription polymerase chain reaction.

RESULTS

Endometrial morphology and embryo implantation rates were significantly improved on day 8 of transplantation among single-, twice-, or thrice-administered rats. Moreover, UC-MSCs could alleviate fibrosis in general, and reduced the expression of fibrosis markers, α-smooth muscle actin (α-SMA) and transforming growth factor (TGF)-β. The cell proliferation marker Ki-67 had a positive expression in the injured endometrium after UC-MSC transplantation. The endometrial stromal marker vimentin and epithelial marker cytokeratin-19 (CK-19) expressions were visibly increased. The expression of vascular markers CD31, vascular endothelial growth factor (VEGF)A, and matrix metalloprotein (MMP)9 was generally upregulated. Proinflammatory factors interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-2 were significantly downregulated in the rats administered UC-MSCs twice and thrice.

CONCLUSIONS

UC-MSC transplantation contributed to the repair of endometrial injury and restoration of fertility, likely through the suppression of excessive fibrosis and inflammation, and enhancement of endometrial cell proliferation and vascular remodeling.

Regulation of Placental Development and Its Impact on Fetal Growth-New Insights From Mouse Models

The placenta is the chief regulator of nutrient supply to the growing embryo during gestation. As such, adequate placental function is instrumental for developmental progression throughout intrauterine development. One of the most common complications during pregnancy is insufficient growth of the fetus, a problem termed intrauterine growth restriction (IUGR) that is most frequently rooted in a malfunctional placenta. Together with conventional gene targeting approaches, recent advances in screening mouse mutants for placental defects, combined with the ability to rapidly induce mutations in vitro and in vivo by CRISPR-Cas9 technology, has provided new insights into the contribution of the genome to normal placental development. Most importantly, these data have demonstrated that far more genes are required for normal placentation than previously appreciated. Here, we provide a summary of common types of placental defects in established mouse mutants, which will help us gain a better understanding of the genes impacting on human placentation. Based on a recent mouse mutant screen, we then provide examples on how these data can be mined to identify novel molecular hubs that may be critical for placental development. Given the close association between placental defects and abnormal cardiovascular and brain development, these functional nodes may also shed light onto the etiology of birth defects that co-occur with placental malformations. Taken together, recent insights into the regulation of mouse placental development have opened up new avenues for research that will promote the study of human pregnancy conditions, notably those based on defects in placentation that underlie the most common pregnancy pathologies such as IUGR and pre-eclampsia.

Efficacy of resveratrol to supplement oral nifedipine treatment in pregnancy-induced preeclampsia

OBJECTIVE

Preeclampsia (PE) is a complication affecting pregnant women worldwide, which usually manifests as severe maternal hypertension. Resveratrol (RESV), a naturally existing polyphenol, is known to exhibit beneficial effects in cardiovascular disease including hypertension. We evaluated the outcome of treatment combining oral nifedipine (NIFE) and RESV against PE.

DESIGN AND METHODS

Using a randomized group assignment, 400 PE patients were enrolled and received oral treatments of either NIFE + RESV or NIFE + placebo. Primary endpoints were defined as time to control blood pressure and time before a new hypertensive crisis. Secondary endpoints were defined as the number of doses needed to control blood pressure, maternal and neonatal adverse effects.

RESULTS

Compared with the NIFE + placebo group, the time needed to control blood pressure was significantly reduced in NIFE + RESV group, while time before a new hypertensive crisis was greatly delayed in NIFE + RESV group. The number of treatment doses needed to control blood pressure was also categorically lower in NIFE + RESV group. No differences in maternal or neonatal adverse effects were observed between the two treatment groups.

CONCLUSION

Our data support the potential of RESV as a safe and effective adjuvant of oral NIFE to attenuate hypertensive symptoms among PE patients.

Peroxisome proliferator activated receptor gamma in human placenta may mediate the adverse effects of phthalates exposure in pregnancy

Peroxisome-proliferator activated receptor gamma (PPARG) in placenta play an important role in pregnancy. Our previous study showed that it mediated the effects of phthalates on placental mRNA expression of estrogen synthetases in rats. To assess the effects of phthalate exposure on PPARG placental expression, and the contribution of PPARG to the effects of phthalates in human. 207 healthy pregnant women were recruited and their cord blood and placenta were collected upon delivery. Three phthalates, estrogens in cord blood and protein expression of PPARG in placenta were measured. Linear regression were used to analyze the relationship between phthalates exposure, PPARG expression and hormones. Phthalate levels in cord blood were positively associated with PPARG protein expression in placenta (p<0.05), whereas estrogens in cord blood were negatively associated with phthalate levels and PPARG expression (p<0.05). This study shows that PPARG in placenta may mediate the adverse effects of phthalates on pregnancy in human.

Matrix Metalloproteinases, Vascular Remodeling, and Vascular Disease

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation through removal of the propeptide domain from their latent zymogen form. MMPs are often secreted in an inactive proMMP form, which is cleaved to the active form by various proteinases including other MMPs. MMPs degrade various protein substrates in ECM including collagen and elastin. MMPs could also influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in vascular tissue remodeling during various biological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension, preeclampsia, atherosclerosis, aneurysm formation, as well as excessive venous dilation and lower extremity venous disease. MMPs are often regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs may serve as biomarkers and potential therapeutic targets for certain vascular disorders.

Role of kisspeptin/GPR54 in the first trimester trophoblast of women with a history of recurrent spontaneous abortion

Trophoblast migration and invasion during pregnancy are under strict physiological control, both temporally and spatially. The trophoblast's ability to invade the endometrium is regulated by the dynamic interaction between invasion-related genes. Once this dynamic balance is broken, the trophoblast exhibits abnormal invasion ability, often resulting in recurrent spontaneous abortion (RSA). Kisspeptins, products of the KISS1 gene, were originally identified as metastasis suppressor peptides with the ability to bind G protein-coupled receptors (i.e., GPR54). The human placenta expresses both KISS1 and kisspeptin receptor (KISS1R) mRNA within the trophoblast compartment, where it is thought to inhibit physiological invasion. In order to explore the effects of KISS1 on the biological behavior of human trophoblasts and its association with RSA, we used immunohistochemistry to compare the expression of kisspeptin and GPR54 at the maternal-fetal interface in RSA cases and cases with normal pregnancy. Abortion-prone CBA/J×DBA/2 matings were established as a model for spontaneous abortion, while non-abortion-prone CBA/J×BALB/c matings were used as a model for normal pregnancy. The expression of kisspeptin and GPR54 in mice placental tissues was compared by immunohistochemistry. Gene recombination and transfection technology were used to evaluate the effects of the KISS1 gene and kisspeptin on JAR cells in terms of proliferation, colony formation ability, and migration and invasion abilities. Kisspeptin/GPR54 revealed lower levels of expression at the maternal-fetal surface in RSA patients compared to controls (P<0.001). Similarly, the expression of kisspeptin/GPR54 at the maternal-fetal interface of spontaneous-abortion mice (CBA/J×DBA/2) was remarkably lower than the group of mice that experienced normal pregnancy (CBA/J×BALB/c) (P<0.05). Data indicated that the KISS1 gene and kisspeptin play a significant role in the inhibition of trophoblast migration and invasion propensity in vitro without affecting cell growth or proliferation. Moreover, kisspeptin appeared to exert an effect in a dose-dependent manner. These data support the fact that the downregulation of kisspeptin/GPR54 may be related to RSA, and that the abnormal expression of KISS1 acts as an invasion-inhibitor gene. Consequently, KISS1 possesses the ability to interfere with normal homeostasis of trophoblast regulation, ultimately resulting in miscarriage.

Celastrol synergizes with oral nifedipine to attenuate hypertension in preeclampsia: a randomized, placebo-controlled, and double blinded trial

Preeclampsia, a disease mainly manifesting as serious hypertension during pregnancy, affects expectant mothers around the globe. Celastrol, a naturally existing triterpenoid, is known to exhibit beneficial effects attenuating cardiovascular symptoms including hypertension. We here assessed the treatment outcome against preeclampsia with a combined use of celastrol and nifedipine. A total of 626 patients with preeclampsia were enrolled, screened, and assigned by random to groups receiving either nifedipine + placebo or nifedipine + celastrol orally. Time required to control hypertension as well as time before another hypertensive crisis were defined as primary end points. Secondary end points include the number of dosages required to control hypertension, as well as maternal and neonatal adverse effects. The time to control hypertension showed a marked reduction in nifedipine + celastrol group, while time before a new hypertensive crisis was significantly lengthened with the treatment, compared with the nifedipine + placebo group. The number of dosages required to control hypertension was also lower in the nifedipine + celastrol group. The two treatment groups were not statistically different regarding adverse effects, either maternal or neonatal. Results from the current study provide evidence for the potential role of celastrol serving as an effective and safe adjuvant to oral nifedipine against hypertension in patients with preeclampsia.

New Insights into the Role of Matrix Metalloproteinases in Preeclampsia

Preeclampsia is a severe pregnancy complication globally, characterized by poor placentation triggering vascular dysfunction. Matrix metalloproteinases (MMPs) exhibit proteolytic activity implicated in the efficiency of trophoblast invasion to the uterine wall, and a dysregulation of these enzymes has been linked to preeclampsia. A decrease in MMP-2 and MMP-9 interferes with the normal remodeling of spiral arteries at early pregnancy stages, leading to the initial pathophysiological changes observed in preeclampsia. Later in pregnancy, an elevation in MMP-2 and MMP-9 induces abnormal release of vasoactive factors conditioning hypertension. Although these two enzymes lead the scene, other MMPs like MMP-1 and MMP-14 seem to have a role in this pathology. This review gathers published recent evidence about the implications of different MMPs in preeclampsia, and the potential use of these enzymes as emergent biomarkers and biological therapeutic targets, focusing on studies involving human subjects.

Transcriptional Dynamics of Cultured Human Villous Cytotrophoblasts

During human pregnancy, cytotrophoblasts (CTBs) play key roles in uterine invasion, vascular remodeling, and anchoring of the feto-placental unit. Due to the challenges associated with studying human placentation in utero, cultured primary villous CTBs are used as a model of the differentiation pathway that leads to invasion of the uterine wall. In vitro, CTBs emulate in vivo cell behaviors, such as migration, aggregation, and substrate penetration. Although some of the molecular features related to these cell behaviors have been described, the underlying mechanisms, at a global level, remain undefined at midgestation. Thus, in this study, we characterized second-trimester CTB differentiation/invasion in vitro, correlating the major morphological transitions with the transcriptional changes that occurred at these steps. After plating on Matrigel as individual cells, CTBs migrated toward each other and formed multicellular aggregates. In parallel, using a microarray approach, we observed differentially expressed (DE) genes across time, which were enriched for numerous functions, including cell migration, vascular remodeling, morphogenesis, cell communication, and inflammatory signaling. DE genes encoded several molecules that we and others previously linked to critical CTB function in vivo, suggesting that the novel DE molecules we discovered played important roles. Immunolocalization confirmed that CTBs in situ gave a signal for two of the most highly expressed genes in vitro. In summary, we characterized, at a global level, the temporal dynamics of primary human CTB gene expression in culture. These data will enable future analyses of various types of in vitro perturbations-for example, modeling disease processes and environmental exposures.

Matrix Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy is associated with marked hemodynamic and uterine changes that allow adequate uteroplacental blood flow and uterine expansion for the growing fetus. These pregnancy-associated changes involve significant uteroplacental and vascular remodeling. Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. Increases in MMP-2 and MMP-9 have been implicated in vasodilation, placentation, and uterine expansion during normal pregnancy. The increases in MMPs could be induced by the increased production of estrogen and progesterone during pregnancy. MMP expression/activity may be altered during complications of pregnancy. Decreased vascular MMP-2 and MMP-9 may lead to decreased vasodilation, increased vasoconstriction, hypertensive pregnancy, and preeclampsia. Abnormal expression of uteroplacental integrins, cytokines, and MMPs may lead to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate remodeling of spiral arteries, and reduced uterine perfusion pressure (RUPP). RUPP may cause imbalance between the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the proangiogenic vascular endothelial growth factor and placental growth factor, or stimulate the release of inflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could target MMPs in the extracellular matrix as well as endothelial and vascular smooth muscle cells, causing generalized vascular dysfunction, increased vasoconstriction and hypertension in pregnancy. MMP activity can also be altered by endogenous tissue inhibitors of metalloproteinases (TIMPs) and changes in the MMP/TIMP ratio. In addition to their vascular effects, decreases in expression/activity of MMP-2 and MMP-9 in the uterus could impede uterine growth and expansion and lead to premature labor. Understanding the role of MMPs in uteroplacental and vascular remodeling and function could help design new approaches for prediction and management of preeclampsia and premature labor.

Decreased expression of MMP-9 in CD8+ cells in placenta with severe preeclampsia

We compared the number of CD4-positive (CD4⁺) and CD8-positive (CD8⁺) cells in severe and non-severe preeclampsia (PE), and in normal pregnancy. We also evaluated the expression of matrix metalloproteinase 9 (MMP-9) in CD4⁺ and CD8⁺ cells. Immunohistochemistry for CD4⁺ and CD8⁺ was performed on the decidua basalis of 15 severe and 13 non-severe PE women and compared to decidual tissue of 19 normal pregnancies (control group). Co-expression of MMP-9 with CD8⁺ and CD4⁺ cells was determined by double immunofluorescence staining. The median number of CD8⁺ cells/mm² was significantly lower for the severe PE group than for the normal pregnancy group, as was the number of CD4⁺ cells and MMP-9⁺CD8⁺ cells. No statistical difference was found between the non-severe PE group and the normal pregnancy group. The significant decrease of CD4⁺, CD8⁺ and MMP-9⁺CD8⁺ cells at the fetal-maternal interface only in the severe PE group suggests that immunological disorders play a role in the pathophysiology of severe PE.

Ratio of matrix metalloproteinase-2 to -9 is a more accurate predictive biomarker in women with suspected pre-eclampsia

Pre-eclampsia (PE) is a condition unique to pregnancy, and abnormal expression of matrix metalloproteinases (MMPs) has been implicated in its pathogenesis. We aimed to evaluate the reliability of plasma levels of MMP-2, MMP-9 and their relative ratio in predicting PE. A total of 318 women with suspected PE were recruited for the study, who were subsequently either cleared or diagnosed of PE and grouped accordingly. Their baseline characteristics were compared. Blood samples were also collected from all participants, to determine the plasma levels of MMP-2 and MMP-9. The predictive values of levels of MMP-2 and MMP-9, as well as their ratio, were analyzed using the receiver operating characteristic (ROC) curve. Either MMP-2 or MMP-9 alone did not exhibit any obvious differences between normal and PE pregnancies. However the ratio of MMP-2/MMP-9 was significantly higher in PE-affected pregnancy than normal control group. ROC curve analysis also indicated that the MMP-2/MMP-9 ratio provided better compromise between specificity and sensitivity in distinguishing PE from normal pregnancies, than either of the two MMPs alone. MMP-2/MMP-9 ratio is a more accurate biomarker to predict PE than either MMP-2 or MMP-9 alone.

Dlx3 and GCM-1 functionally coordinate the regulation of placental growth factor in human trophoblast-derived cells

Placental growth factor (PGF) is abundantly expressed by trophoblast cells within human placentae and is important for trophoblast development and placental vascularization. Circulating maternal serum levels of PGF are dynamically upregulated across gestation in normal pregnancies, whereas low circulating levels and placental production of PGF have been implicated in the pathogenesis of preeclampsia and other gestational diseases. However, the underlying molecular mechanism of regulating PGF expression in the human placenta remains poorly understood. In this study, we demonstrated that transcription factors Distal-less 3 (DLX3) and Glial cell missing-1 (GCM1) were both sufficient and required for PGF expression in human trophoblast-derived cells by overexpression and knockdown approaches. Surprisingly, while DLX3 and GCM1 were both positive regulators of PGF, co-overexpression of DLX3 and GCM1 led to an antagonist effect on PGF expression on the endogenous gene and a luciferase reporter. Further, deletion and site-directed mutagenesis studies identified a novel regulatory element on the PGF promoter mediating both DLX3- and GCM1-dependent PGF expression. This regulatory region was also found to be essential for the basal activity of the PGF promoter. Finally, Chromatin-immunoprecipitation (ChIP) assays revealed colocalization of DLX3 and GCM1 at the identified regulatory region on the PGF promoter. Taken together, our studies provide important insights into intrinsic regulation of human placental PGF expression through the functional coordination of DLX3 and GCM1, and are likely to further the understanding of pathogenesis of PGF dysregulation in preeclampsia and other disease conditions.

CASPASE-8 gene polymorphisms (rs13416436 and rs2037815) are not associated with preeclampsia development in Brazilian women

BACKGROUND

Preeclampsia is responsible for considerable mortality and morbidity of mother and sibling. The etiology of preeclampsia is still unknown. Family studies indicate the involvement of genes located on chromosome 2 in preeclampsia development. Considering the importance of apoptosis and chromosome 2, one promising candidate for the study of the genetic cause of this syndrome is the CASPASE-8 gene, which was chosen as the subject of this study.

OBJECTIVE

The aim of this study was to determine the frequencies of the genotypes for CASP8 gene polymorphisms (rs13416436 and rs2037815) and to associate these with preeclampsia development in Brazilian women.

METHODS

Women with and without preeclampsia were investigated. Accordingly, peripheral blood was collected and DNA extracted, followed by genotyping using Real-time PCR with hydrolysis probe (Taqman^® Life Technologies).

RESULTS

The results showed no association between genotypes and preeclampsia development for both polymorphisms studied (χ²=1.03; p = 0.59, for rs13416436 and χ²=1.06; p = 0.58 for rs2037815).

CONCLUSIONS

It seems that CASP8 gene polymorphisms (rs13416436 and rs2037815) are not important candidates for the development of preeclampsia. Other genes related to the apoptosis process or other polymorphisms in this gene should be studied in order to understand better the etiology of preeclampsia.

Up-regulation of CD81 inhibits cytotrophoblast invasion and mediates maternal endothelial cell dysfunction in preeclampsia

Preeclampsia (PE) is initiated by abnormal placentation in the early stages of pregnancy, followed by systemic activation of endothelial cells of the maternal small arterioles in the late second or third trimester (TM) of pregnancy. During normal pregnancy, placental cytotrophoblasts (CTBs) invade the maternal uterine wall and spiral arteries, whereas this process is interrupted in PE. However, it is not known how the malformed placenta triggers maternal endothelial crisis and the associated manifestations. Here, we have focused on the association of CD81 with PE. CD81, a member of the tetraspanin superfamily, plays significant roles in cell growth, adhesion, and motility. The function of CD81 in human placentation and its association with pregnancy complications are currently unknown. In the present study, we have demonstrated that CD81 was preferentially expressed in normal first TM placentas and progressively down-regulated with gestation advance. In patients with early-onset severe PE (sPE), CD81 expression was significantly up-regulated in syncytiotrophoblasts (STBs), CTBs and the cells in the villous core. In addition, high levels of CD81 were observed in the maternal sera of patients with sPE. Overexpressing CD81 in CTBs significantly decreased CTB invasion, and culturing primary human umbilical vein endothelial cells (HUVECs) in the presence of a high dose of exogenous CD81 resulted in interrupted angiogenesis and endothelial cell activation in vitro. Importantly, the phenotype of human PE was mimicked in the CD81-induced rat model.

MTA3 Regulates Extravillous Trophoblast Invasion Through NuRD Complex

Extravillous trophoblast (EVT) invasion is required for remodeling uterine tertiary arteries and placenta development during pregnancy. Compromised EVT invasion may contribute to the pathology of placenta-related diseases. Metastasis -associated protein 3 (MTA3) is one of the subunits of nucleosome remodeling and deacetylation (NuRD) complex that represses transcription in a histone deacetylase-dependent manner. MTA3 is reported to be down-regulated in preeclamptic placentas, suggesting its potential role in EVT invasion. Here, we investigate the role of MTA3 in EVT invasion by studying its molecular mechanisms in EVT cells. First, we confirmed MTA3 expression in the EVT cells in human placenta using immunohistochemistry. We then used lentivirus-mediated MTA3 short hairpin RNA (shRNA) to knock down MTA3 expression in EVT-derived HTR8/SVneo cells and found higher invasion capacity in MTA3 knockdown cells. Using quantitative real-time PCR, we showed higher expression of invasion-related genes matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and transcription factor Snail in MTA3 knockdown compared with control cells. Co-immunoprecipitation-Western blot assay showed the protein-protein interaction of histone deacetylase 1 (HDAC1), a subunit of NuRD, with MTA3 in HTR8/SVneo cells. Co-immunoprecipitation-Mass spectrometry assay further identified 71 proteins interacting with MTA3, including NuRD subunits, heterochromatin proteins, epigenetics modifiers and transcription factors. This result not only indicated the involvement of NuRD complex in MTA3’s function, but also demonstrated the complicated multiple co-players in MTA3 and NuRD complex mediated transcription repression in EVT. In summary, our data demonstrates that MTA3 regulates EVT invasion and related gene expression via NuRD complex in EVT.

Nicotinamide benefits both mothers and pups in two contrasting mouse models of preeclampsia

Preeclampsia (PE) complicates ∼5% of human pregnancies and is one of the leading causes of pregnancy-related maternal deaths. The only definitive treatment, induced delivery, invariably results in prematurity, and in severe early-onset cases may lead to fetal death. Many currently available antihypertensive drugs are teratogenic and therefore precluded from use. Nonteratogenic antihypertensives help control maternal blood pressure in PE, but results in preventing preterm delivery and correcting fetal growth restriction (FGR) that also occurs in PE have been disappointing. Here we show that dietary nicotinamide, a nonteratogenic amide of vitamin B₃, improves the maternal condition, prolongs pregnancies, and prevents FGR in two contrasting mouse models of PE. The first is caused by endotheliosis due to excess levels in the mothers of a soluble form of the receptor for vascular endothelial growth factor (VEGF), which binds to and inactivates VEGF. The second is caused by genetic absence of Ankiryn-repeat-and-SOCS-box-containing-protein 4, a factor that contributes to the differentiation of trophoblast stem cells into the giant trophoblast cells necessary for embryo implantation in mice; its absence leads to impaired placental development. In both models, fetal production of ATP is impaired and FGR is observed. We show here that nicotinamide decreases blood pressure and endotheliosis in the mothers, probably by inhibiting ADP ribosyl cyclase (ADPRC), and prevents FGR, probably by normalizing fetal ATP synthesis via the nucleotide salvage pathway. Because nicotinamide benefits both dams and pups, it merits evaluation for preventing or treating PE in humans.

Distinct expression profiles of lncRNAs between early-onset preeclampsia and preterm controls

Early-onset preeclampsia (EOPE), which is the most severe form of the syndrome, confers a high risk of neonatal morbidity and perinatal death. We aim to study the roles of long non-coding RNAs (lncRNAs) in the pathogenesis of early-onset preeclampsia (EOPE). Therefore, we examined the expression profiles of lncRNAs between early-onset preeclampsia and preterm controls using microarray analysis. Quantitative real-time PCR (qRT-PCR) was performed to verify the selected differentially expressed lncRNAs. In total, we identified 15,646 upregulated and 13,178 downregulated lncRNAs in the placenta of EOPE patients compared to the preterm controls. Gene ontology and pathway analysis revealed that compared to the preterm controls, many of the processes over-represented in the EOPE patients were related to cell migration and cell motility. A selection of the differentially expressed lncRNA transcripts was confirmed using qRT-PCR, particularly RP11-465L10.10, which is associated with the MMP9 gene. These data may offer a background/reference resource for future functional studies of lncRNAs related to EOPE.

HIF-KDM3A-MMP12 regulatory circuit ensures trophoblast plasticity and placental adaptations to hypoxia

The hemochorial placenta develops from the coordinated multilineage differentiation of trophoblast stem (TS) cells. An invasive trophoblast cell lineage remodels uterine spiral arteries, facilitating nutrient flow, failure of which is associated with pathological conditions such as preeclampsia, intrauterine growth restriction, and preterm birth. Hypoxia plays an instructive role in influencing trophoblast cell differentiation and regulating placental organization. Key downstream hypoxia-activated events were delineated using rat TS cells and tested in vivo, using trophoblast-specific lentiviral gene delivery and genome editing. DNA microarray analyses performed on rat TS cells exposed to ambient or low oxygen and pregnant rats exposed to ambient or hypoxic conditions showed up-regulation of genes characteristic of an invasive/vascular remodeling/inflammatory phenotype. Among the shared up-regulated genes was matrix metallopeptidase 12 (MMP12). To explore the functional importance of MMP12 in trophoblast cell-directed spiral artery remodeling, we generated an Mmp12 mutant rat model using transcription activator-like nucleases-mediated genome editing. Homozygous mutant placentation sites showed decreased hypoxia-dependent endovascular trophoblast invasion and impaired trophoblast-directed spiral artery remodeling. A link was established between hypoxia/HIF and MMP12; however, evidence did not support Mmp12 as a direct target of HIF action. Lysine demethylase 3A (KDM3A) was identified as mediator of hypoxia/HIF regulation of Mmp12 Knockdown of KDM3A in rat TS cells inhibited the expression of a subset of the hypoxia-hypoxia inducible factor (HIF)-dependent transcripts, including Mmp12, altered H3K9 methylation status, and decreased hypoxia-induced trophoblast cell invasion in vitro and in vivo. The hypoxia-HIF-KDM3A-MMP12 regulatory circuit is conserved and facilitates placental adaptations to environmental challenges.

Distribution of HLA-G extended haplotypes and one HLA-E polymorphism in a large-scale study of mother-child dyads with and without severe preeclampsia and eclampsia

The etiological pathways and pathogenesis of preeclampsia have rendered difficult to disentangle. Accumulating evidence points toward a maladapted maternal immune system, which may involve aberrant placental expression of immunomodulatory human leukocyte antigen (HLA) class Ib molecules during pregnancy. Several studies have shown aberrant or reduced expression of HLA-G in the placenta and in maternal blood in cases of preeclampsia compared with controls. Unlike classical HLA class Ia loci, the nonclassical HLA-G has limited polymorphic variants. Most nucleotide variations are clustered in the 5'-upstream regulatory region (5'URR) and 3'-untranslated regulatory region (3'UTR) of HLA-G and reflect a stringent expressional control. Based on genotyping and full gene sequencing of HLA-G in a large number of cases and controls (n > 900), the present study, which to our knowledge is the largest and most comprehensive performed, investigated the association between the HLA-G 14-bp ins/del (rs66554220) and HLA-E polymorphisms in mother and newborn dyads from pregnancies complicated by severe preeclampsia/eclampsia and from uncomplicated pregnancies. Furthermore, results from extended HLA-G haplotyping in the newborns are presented in order to assess whether a combined contribution of nucleotide variations spanning the 5'URR, coding region, and 3'UTR of HLA-G describes the genetic association with severe preeclampsia more closely. In contrast to earlier findings, the HLA-G 14-bp ins/del polymorphism was not associated with severe preeclampsia. Furthermore, the polymorphism (rs1264457) defining the two nonsynonymous HLA-E alleles, HLA-E*01:01:xx:xx and HLA-E*01:03:xx:xx, were not associated with severe preeclampsia. Finally, no specific HLA-G haplotypes were significantly associated with increased risk of developing severe preeclampsia/eclampsia.

Maternal obesity drives functional alterations in uterine NK cells

Over one-fifth of North American women of childbearing age are obese, putting these women at risk for a variety of detrimental chronic diseases. In addition, obesity increases the risk for developing major complications during pregnancy. The mechanisms by which obesity contributes to pregnancy complications and loss remain unknown. Increasing evidence indicates that obesity results in major changes to adipose tissue immune cell composition and function; whether or not obesity also affects immune function in the uterus has not been explored. Here we investigated the effect of obesity on uterine natural killer (uNK) cells, which are essential for uterine artery remodeling and placental development. Using a cohort of obese or lean women, we found that obesity led to a significant reduction in uNK cell numbers accompanied with impaired uterine artery remodeling. uNK cells isolated from obese women had altered expression of genes and pathways associated with extracellular matrix remodeling and growth factor signaling. Specifically, uNK cells were hyper-responsive to PDGF, resulting in overexpression of decorin. Functionally, decorin strongly inhibited placental development by limiting trophoblast survival. Together, these findings establish a potentially new link between obesity and poor pregnancy outcomes, and indicate that obesity-driven changes to uterine-resident immune cells critically impair placental development.

Preeclampsia, of mice and women

Preeclampsia (PE) is a devastating disorder of pregnancy that affects up to 8% of pregnant women in the United States. The diagnosis of PE is made by the presentation of new-onset hypertension, ≥140 mmHg systolic blood pressure (BP) or ≥90 mmHg diastolic BP, and either proteinuria or another accompanying sign/symptom, such as renal insufficiency, thrombocytopenia, hepatic dysfunction, pulmonary edema, or cerebral/visual. These signs can occur suddenly and without warning. PE that presents before 34 wk of gestation is considered early onset and carries a greater risk for perinatal morbidity/mortality than late-onset PE that occurs at or after 34 wk of gestation. At this time there is no cure for PE, and the only effective treatment is delivery of the baby and placenta. If allowed to progress to eclampsia (PE with neurologic involvement), seizures will occur and possibly death through stroke. PE also carries the risk of significant fetal and neonatal morbidity/mortality in addition to long-term health risks for mother and child. Despite significant research efforts to accurately predict, diagnose, and treat PE, a cure eludes us. Elucidating the pathophysiological mechanisms that can cause PE will aid in our ability to accurately prevent, manage, and treat PE to avoid maternal and fetal losses. Intense research efforts are focused on PE, and the mouse has proven to be a useful animal model for investigating molecular mechanisms that may hold the key to unraveling the mysteries of PE in women.