Differential Expression of HrtA1 and ADAM12 in Placentas from Preeclamptic and Normotensive Pregnancies

Circ_0001326 suppresses trophoblast cell proliferation, invasion, migration and epithelial-mesenchymal transition progression in preeclampsia by miR-188-3p/HtrA serine peptidase 1 axis

BACKGROUND

It has been reported that the alteration of circular RNAs (circRNAs) during preeclampsia (PE) can be associated with the pathogenesis of this disease. Herein, this work investigated the potential functions and mechanism of circ_0001326 in PE process.

METHODS

The levels of genes and proteins were evaluated by quantitative real-time PCR (qRT-PCR) and western blotting. The functional experiments were conducted using cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, and wound healing assays, respectively. The binding between miR-188-3p and circ_0001326 or HtrA serine peptidase 1 (HTRA1) was verified by bioinformatics analysis and dual-luciferase reporter assays.

RESULTS

Circ_0001326 and HTRA1 expression was increased, while miR-188-3p expression was decreased in the placental tissues of preeclamptic singleton pregnant women compared with the normal pregnant women. Functionally, up-regulation of circ_0001326 or HTRA1, or down-regulation of miR-188-3p led to the arrest of cell growth, invasion, migration and epithelial-mesenchymal transition (EMT) process in trophoblast cells. Mechanistically, circ_0001326 acted as a sponge for miR-188-3p, which directly targeted HTRA1. Moreover, circ_0001326 could regulate HTRA1 through sequestering miR-188-3p. A series of rescue experiments showed that miR-188-3p reversed the inhibitory effects of circ_0001326 knockdown on above behaviors of trophoblast cells. Besides that, HTRA1 silencing attenuated the action of miR-188-3p inhibitor on trophoblast cell phenotype alteration.

CONCLUSION

Our study demonstrated that circ_0001326 could promote trophoblast cell proliferation, invasion, migration and EMT in PE by miR-188-3p/HTRA1 axis, indicating a novel insight into the pathogenesis of PE.

Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.

Melatonin regulates trophoblast pyroptosis, invasion and migration in preeclampsia by inhibiting HtrA1 transcription through the microRNA-520c-3p/SETD7 axis

OBJECTIVE

Melatonin has an inhibitory effect on preeclampsia (PE). This study was launched to explore the way that melatonin regulated trophoblast migration, invasion, and pyroptosis in PE and to provide new ideas for the diagnosis and treatment of PE.

METHODS

Expression levels of melatonin receptors (MT1 and MT2), microRNA (miR)-520c-3p, SETD7, and HtrA1 in placental tissues and HTR8/SVneo cells were measured by RT-qPCR and Western blot. Scratch, Transwell, and Western blot assays were performed to detect migration, invasion, and pyroptosis of hypoxia/reoxygenation (H/R)-treated HTR8/SVneo cells. Dual-luciferase reporter assay was utilized to verify the targeting relationship between miR-520c-3p and SETD7. ChIP experiment was conducted to detect the enrichment of H3K4me3 and SETD7 in HtrA1 promoter.

RESULTS

Low expression of MT1, MT2, and miR-520c-3p and high expression of SETD7 and HtrA1 were observed in the placental tissues of PE patients and H/R-treated HTR8/Svneo cells. A high concentration of melatonin promoted migration and invasion and inhibited pyroptosis of PE cell models. Knockdown of miR-520c-3p, overexpression of SETD7, or overexpression of HtrA1 impaired migration and invasion and accelerated pyroptosis of H/R-treated HTR8/SVneo cells, but these outcomes could be reversed by treatment with 1000 μM melatonin. miR-520c-3p targeted SETD7 which promoted histone methylation in the promoter region of HtrA1.

CONCLUSION

Melatonin may inhibit HtrA1 transcription through the miR-520c-3p/SETD7 axis to promote trophoblast invasion and migration and reduce trophoblast pyroptosis in PE.

Transcriptomic analysis of primate placentas and novel rhesus trophoblast cell lines informs investigations of human placentation

BACKGROUND

Proper placentation, including trophoblast differentiation and function, is essential for the health and well-being of both the mother and baby throughout pregnancy. Placental abnormalities that occur during the early stages of development are thought to contribute to preeclampsia and other placenta-related pregnancy complications. However, relatively little is known about these stages in humans due to obvious ethical and technical limitations. Rhesus macaques are considered an ideal surrogate for studying human placentation, but the unclear translatability of known human placental markers and lack of accessible rhesus trophoblast cell lines can impede the use of this animal model.

RESULTS

Here, we performed a cross-species transcriptomic comparison of human and rhesus placenta and determined that while the majority of human placental marker genes (HPGs) were similarly expressed, 952 differentially expressed genes (DEGs) were identified between the two species. Functional enrichment analysis of the 447 human-upregulated DEGs, including ADAM12, ERVW-1, KISS1, LGALS13, PAPPA2, PGF, and SIGLEC6, revealed over-representation of genes implicated in preeclampsia and other pregnancy disorders. Additionally, to enable in vitro functional studies of early placentation, we generated and thoroughly characterized two highly pure first trimester telomerase (TERT) immortalized rhesus trophoblast cell lines (iRP-D26 and iRP-D28A) that retained crucial features of isolated primary trophoblasts.

CONCLUSIONS

Overall, our findings help elucidate the molecular translatability between human and rhesus placenta and reveal notable expression differences in several HPGs and genes implicated in pregnancy complications that should be considered when using the rhesus animal model to study normal and pathological human placentation.