ENaC mediates human extravillous trophblast cell line (HTR8/SVneo) invasion by regulating levels of matrix metalloproteinase 2 (MMP2)

USP8 targeted by Mir-874-3p promotes trophoblastic cell invasion by stabilizing the expression of ENaC on trophoblast membrane

The aim of this study was to investigate the role of ubiquitin-specific peptidase 8 (USP8) in human trophoblast cells and its molecular mechanism. Based on the GSE30186 dataset, USP8 was identified as a downregulated gene in pre-eclampsia (PE). Analysis of clinical samples also revealed that USP8 expression at both the mRNA and protein levels in placental tissue from patients with PE was significantly lower than that from healthy pregnant women. Plate clone formation, scratch-wound healing, Transwell, tubule formation, and western blot assays collectively revealed that USP8 overexpression promoted the proliferation, migration, invasion, and pro-angiogenesis function of trophoblast cells, while USP8 knockdown induced the opposite effects. Bioinformatics analysis and luciferase reporter assay results indicated that the 3' untranslated region of USP8 was targeted by miR-874-3p. USP8 expression in the placental tissue of patients with PE was significantly lower than that of healthy pregnant women. USP8 actively regulated the growth and invasion of human trophoblast cells and stabilized the epithelial sodium channel (ENaC) on the cell membrane. MiR-874 targeted USP8 in the trophoblast cells and upregulation of miR-874-3p resulted in a decrease in the proliferation, migration, invasion, and pro-angiogenesis ability of trophoblast cells. These results indicate that USP8 can reverse the above mentioned negative effects of miR-874-3p on trophoblast cells. USP8 targeted by miR-874-3p facilitates the invasion of trophoblastic cells by stabilizing the expression of the ENaC, which may be a possible therapeutic target for PE.

Placental ion channels: potential target of chemical exposure

The placenta is an important organ for the exchange of substances between the fetus and the mother, hormone secretion, and fetoplacental immunological defense. Placenta has an organ-specific distribution of ion channels and trophoblasts, and placental vessels express a large number of ion channels. Several placental housekeeping activities and pregnancy complications are at least partly controlled by ion channels, which are playing an important role in regulating hormone secretion, trophoblastic homeostasis, ion transport, and vasomotor activity. The function of several placental ion channels (Na, Ca, and Cl ion channels, cation channel, nicotinic acetylcholine receptors, and aquaporin-1) is known to be influenced by chemical exposure, i.e., their responses to different chemicals have been tested and confirmed in experimental models. Here, we review the possibility that placental ion channels are targets of toxicological concern in terms of placental function, fetal growth, and development.

Placental Models for Evaluation of Nanocarriers as Drug Delivery Systems for Pregnancy Associated Disorders

Pregnancy-associated disorders affect around 20% of pregnancies each year around the world. The risk associated with pregnancy therapeutic management categorizes pregnant women as "drug orphan" patients. In the last few decades, nanocarriers have demonstrated relevant properties for controlled drug delivery, which have been studied for pregnancy-associated disorders. To develop new drug dosage forms it is mandatory to have access to the right evaluation models to ensure their usage safety and efficacy. This review exposes the various placental-based models suitable for nanocarrier evaluation for pregnancy-associated therapies. We first review the current knowledge about nanocarriers as drug delivery systems and how placenta can be used as an evaluation model. Models are divided into three categories: in vivo, in vitro, and ex vivo placental models. We then examine the recent studies using those models to evaluate nanocarriers behavior towards the placental barrier and which information can be gathered from these results. Finally, we propose a flow chart on the usage and the combination of models regarding the nanocarriers and nanoparticles studied and the intended therapeutic strategy.

IGFBP1 inhibits the invasion, migration, and apoptosis of HTR-8/SVneo trophoblast cells in preeclampsia

OBJECTIVE

To investigate the effects and underlying mechanisms of IGFBP1 on the biological functions of trophoblasts in simulated preeclampsia.

METHODS

IGFBP1 expression in placenta was determined by immunohistochemistry. HTR-8/SVneo cells were stimulated with/without IGFBP1-overexpression and hypoxia-reoxygenation, and the proliferation, invasion, migration, and apoptosis were detected by CCK8, transwell, and flow cytometry, respectively.

RESULTS

IGFBP1 expression was increased in placenta of preeclampsia. IGFBP1 overexpression inhibited proliferation, invasion, migration, and apoptosis of HTR-8/SVneo cells and induced MMP-26 expression with/without hypoxia-reoxygenation challenge.

CONCLUSION

IGFBP1 affects biological functions of trophoblasts, and it may play a role in pathophysiology of preeclampsia by inducing MMP-26.

Experimental models of maternal-fetal interface and their potential use for nanotechnology applications

During pregnancy, the placenta regulates the transfer of oxygen, nutrients, and residual products between the maternal and fetal bloodstreams and is a key determinant of fetal exposure to xenobiotics from the mother. To study the disposition of substances through the placenta, various experimental models are used, especially the perfused placenta, placental villi explants, and cell lineage models. In this context, nanotechnology, an area of study that is on the rise, enables the creation of particles on nanometric scales capable of releasing drugs aimed at specific tissues. An important reason for furthering the studies on transplacental transfer is to explore the potential of nanoparticles (NPs), in new delivery strategies for drugs that are specifically aimed at the mother, the placenta, or the fetus and that involve less toxicity. Due to the fact that the placental barrier is essential for the interaction between the maternal and fetal organisms as well as the possibility of NPs being used in the treatment of various pathologies, the aim of this review is to present the main experimental models used in studying the maternal-fetal interaction and the action of NPs in the placental environment.

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.

Maspin impairs the function of endothelial cells: an implying pathway of preeclampsia

Backgroud

Widespread endothelial injury contributes to the occurrence of preeclampsia. Maspin, first identified as a tumor suppressor, plays a critical role in cell invasion and angiogenesis. Our previous studies found that the expression of maspin was increased in preeclampsic placenta. In this research, we studied the function of human umbilical vein endothelial cells (HUVECs) to explore the role and possible mechanism of maspin gene in the pathogenesis of preeclampsia.

Methods

HUVECs were treated with different concentration of recombinant human maspin protein (r-maspin) during normoxia and hypoxia, we detected the proliferation, apoptosis, migration and tube formation of HUVECs. We also assessed nitride oxide (NO) synthesis and the expression of matrix metalloproteinase 2 (MMP2) to further explore the underlying molecular mechanism.

Results

There was only slight maspin expression at mRNA level in HUVECs. Treated HUVECs with r-maspin, the proliferation of HUVECs was significantly promoted both under normoxia and hypoxia. The tubes formed by HUVECs were significantly inhibited and NO synthesis was significantly reduced by r-maspin. Meantime, r-maspin also inhibited MMP2 expression and activity in HUVECs. However, there was no significant change in the migration and apoptosis of HUVECs.

Conclusions

Maspin may be an important participant for mediating endothelial function and ultimately leads to the occurence of preeclamsia.

Potential Roles of Amiloride-Sensitive Sodium Channels in Cancer Development

The ENaC/degenerin ion channel superfamily includes the amiloride-sensitive epithelial sodium channel (ENaC) and acid sensitive ionic channel (ASIC). ENaC is a multimeric ion channel formed by heteromultimeric membrane glycoproteins, which participate in a multitude of biological processes by mediating the transport of sodium (Na⁺) across epithelial tissues such as the kidney, lungs, bladder, and gut. Aberrant ENaC functions contribute to several human disease states including pseudohypoaldosteronism, Liddle syndrome, cystic fibrosis, and salt-sensitive hypertension. Increasing evidence suggests that ion channels not only regulate ion homeostasis and electric signaling in excitable cells but also play important roles in cancer cell behaviors such as proliferation, apoptosis, invasion, and migration. Indeed, ENaCs/ASICs had been reported to be associated with cancer characteristics. Given their cell surface localization and pharmacology, pharmacological strategies to target ENaC/ASIC family members may be promising cancer therapeutics.