A synergistic negative effect of gestational smoke-exposure and small litter size on rat placental efficiency, vascularisation and angiogenic factors mRNA expression

Angiopoietin-2 regulates the phenotypic switch of vascular smooth muscle cells

During uterine spiral artery remodeling, vascular smooth muscle cells (VSMCs) become disorganized and undergo phenotypic switching from a contractile to a more synthetic phenotype. We have previously reported that uterine natural killer cells induce this VSMC phenotypic switching by secreting angiopoietin-2 (Ang-2). Here, we identified the specific mechanisms by which Ang-2 plays a role in this phenomenon. VSMCs isolated from human umbilical arteries were used as an in vitro model to investigate the role of Ang-2 in phenotypic switching. Human decidua tissue from preeclamptic and control pregnancies was collected to compare the expression levels of related proteins. Ang-2 induced a more synthetic phenotype in VSMCs as evidenced by decreased contractile marker expression, increased proliferation and migration, and an altered cytoskeleton. VSMC expressed integrin β6 interacted directly with Ang-2 and induced phosphorylation of FAK (S910 and Y397), AKT (S473), and mTOR (S2448). Knockdown of FAK recovered the calponin loss induced by Ang-2 and resulted in lower EZH2 abundance. Inhibition of FAK and EZH2 both attenuated Ang-2-induced inhibition of the LC3 II/LC3 I ratio and ATG7 expression, and proliferation. Lipid peroxidation inhibition by ferrostatin-1 or the IL-8 receptor antagonist navarixin inhibited the Ang-2-induced migration. IL-8 secretion was significantly lower with lipid peroxidation inhibition. In preeclamptic decidua, there were more unremodeled spiral arteries, and the abundance of Ang-2 was dysregulated. Ang-2 dysregulation may disrupt spiral artery remodeling and contribute to preeclampsia. Ang-2 may be a novel therapeutic target for the treatment of pregnancy complications affected by incomplete spiral artery remodeling.

Differential mRNA and lncRNA Expression Profiles Associated with Early Pregnancy Loss in ART Patients

Early pregnancy loss (EPL) is the most common complication in assisted reproductive technology (ART). However, the precise causes for nearly 50% patients remain unexplained. In the current study, we aimed to discover the differentially expressed profiling of mRNAs and lncRNAs by RNA sequencing (RNA-seq). Human chorionic villi tissues were collected from patients with EPL and natural control (NC) group. RNA sequencing (RNA-seq) of these specimens was performed for transcriptome analysis. As a result, we identified a total of 141 mRNAs and 137 lncRNAs that were significantly differentially expressed between villi tissues from EPL and NC. Functional enrichment analyses indicated enrichment of differentially expressed genes involved in pathways were associated with growth hormone receptor binding, PI3K-Akt signaling pathway, Jak-STAT signaling pathway, transcriptional misregulation in cancer, metabolic pathways and Rap1 signaling pathway. Additionally, the co-expression networks (lncRNA-miRNA-mRNA) was constructed based on the correlation analysis between the differentially expressed RNAs.7 mRNAs and 6 lncRNAs were successfully technically validated with RT-PCR. In conclusion, our results suggest a direction for the further study of EPL-related mRNAs and lncRNAs and may ultimately assist in understanding the pathogenesis of EPL.

Angiopoietin 2 stimulates trophoblast invasion via a mechanism associated with JNK signaling

Extravillous trophoblast cell (EVT) invasion is tightly controlled, and its dysregulation can lead to altered spiral artery remodeling and contribute to a number of different pregnancy complications. Angiopoietin-2 (Ang-2) is expressed by trophoblast cells and various cells in the decidua, and trophoblast cells express its receptor, Tie2. Ang-2 has been shown to play roles in tumor progression and metastasis but it is not known if it also regulates EVT invasion. Here, we show that both the HTR-8/SVneo cell line and primary isolates of human EVT expressed various integrins and the Tie2 receptor, and Ang-2 stimulated their migration and/or invasion. Ang-2 increased expression of matrix metalloproteinase (MMP)2 and MMP9, altered the cytoskeleton of HTR-8/SVneo cells and also induced phosphorylation of Tie2, JNK and c-Jun. Inhibition of p-JNK (using SP600125) blocked the Ang-2 induced invasion of HTR-8/SVneo cells. In addition, inhibition of Tie2 (pexmetinib) and integrin signaling (RGDS and ATN-161) also blocked Ang-2-induced invasion. In conclusion, we demonstrate that Ang-2 can stimulate EVT invasion via a mechanism associated with activation of both the Tie2 receptor and integrins, which appear to work through different pathways; Tie2 through the JNK/c-JUN pathway and integrins through an as yet unidentified pathway(s). We therefore propose that any alterations in Ang-2 expression in the decidua would lead to an imbalance in pro- and anti-invasive factors, disrupting regulation of EVT invasion and spiral artery remodeling and thereby contribute to the etiology of several complications of pregnancy.

Associations between metal concentrations in whole blood and placenta previa and placenta accreta: the Japan Environment and Children's Study (JECS)

Background

Placenta previa and placenta accreta associate with high morbidity and mortality for both mothers and fetus. Metal exposure may have relationships with placenta previa and placenta accreta. This study analyzed the associations between maternal metal (cadmium [Cd], lead [Pb], mercury [Hg], selenium [Se], and manganese [Mn]) concentrations and placenta previa and placenta accreta.

Methods

We recruited 17,414 women with singleton pregnancies. Data from a self-administered questionnaire regarding the first trimester and medical records after delivery were analyzed. Maternal blood samples were collected to measure metal concentrations. The subjects were classified into four quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations.

Results

The odds ratio for placenta previa was significantly higher among subjects with Q4 Cd than those with Q1 Cd. The odds ratio for placenta previa was significantly higher for subjects with Q2 Pb than those with Q1 Pb.

Conclusion

Participants with placenta previa had higher Cd concentrations. However, this study was cross-sectional and lacked important information related to Cd concentration, such as detailed smoking habits and sources of Cd intake. In addition, the subjects in this study comprised ordinary pregnant Japanese women, and it was impossible to observe the relationship between a wide range of Cd exposure and placenta previa. Therefore, epidemiological and experimental studies are warranted to verify the relationship between Cd exposure and pregnancy abnormalities.

Electronic supplementary material

The online version of this article (10.1186/s12199-019-0795-7) contains supplementary material, which is available to authorized users.