Trophoblast Cell Proliferation Research Articles

CircCUL1 inhibits trophoblast cell migration and invasion and promotes cell autophagy by sponging hsa-miR-30e-3p in fetal growth restriction via the ANXA1/PI3K/AKT axis.

Fetal growth restriction (FGR) severely affects the health outcome of newborns and represents a major cause of perinatal morbidity. The precise involvement of circCULT1 in the progression of FGR remains unclear. We performed next-generation sequencing and RT-qPCR to identify differentially expressed circRNAs in placental tissues affected by FGR by comparing them with unaffected counterparts. Edu, flow cytometry, and transwell assay were conducted to detect HTR8/SVneo cell's function in regard to cell proliferation, migration, and invasion. The interaction between circCUL1 and hsa-miR-30e-3p was assessed through dual-luciferase reporter assays, validation of the interaction between circCUL1 and ANXA1 was performed using RNA pulldown and immunoprecipitation assays. Western blot analysis was performed to evaluate protein levels of autophagy markers and components of the PI3K/AKT signaling pathway. A knockout (KO) mouse model was established for homologous mmu-circ-0001469 to assess fetal mouse growth and development indicators. Our findings revealed an upregulation of circCUL1 expression in placental tissues from patients with FGR. We found that suppression of circCUL1 increased the trophoblast cell proliferation, migration, and invasion, circCUL1 could interact with hsa-miR-30e-3p. Further, circCUL1 stimulated autophagy, modulating trophoblast cell autophagy via the ANXA1/PI3K/AKT pathway, and a notable disparity was observed, with KO mice displaying accelerated embryo development and exhibiting heavier placentas in comparison to wild-type C57BL/6 mice. By modulating the ANXA1/PI3K/AKT signaling pathway through the interaction with hsa-miR-30e-3p, circCUL1 promotes autophagy while concurrently suppressing trophoblast cell proliferation, migration, and invasion. These findings offer novel insights into potential diagnostic markers and therapeutic targets for FGR research.

MiR-371-5p regulates trophoblast cell proliferation, migration, and invasion by directly targeting ZNF516.

Despite its prevalence, preeclampsia (PE) remains unclear as to its etiology. Here, we aimed to investigate the mechanisms regulating differences in the gene expression of zinc-finger protein 516 (ZNF516) in the placenta. The expression of the placental ZNF516 gene and its association with critical clinical markers were verified, and a rigorous correlation analysis was conducted. With a dual-luciferase reporter gene assay, microRNA targeting the ZNF516 gene was predicted and confirmed. Finally, the molecular processes associated with ZNF516 were explored via microarray and bioinformatic analyses. In hypoxic conditions, miR-371-5p expression was reduced, resulting in ZNF516 expression being induced. Moreover, ZNF516 was shown to hinder trophoblast cell migration and invasion while enhancing trophoblast cell death in various in vitro cellular assays, such as cell counting kit-8, colony formation, wound healing, and Transwell assays. Our findings reveal a new regulatory network facilitated by ZNF516. ZNF516 overexpression inhibits trophoblast growth, movement, and penetration, potentially causing problems with placenta formation with the help of miR-371-5p suppression.

Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function

IntroductionSpontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage. MethodsPlacental villi (7–10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2′-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse). ResultsIn placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing. DiscussionLow expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

NANOG regulate the JAK/STAT3 pathway to promote trophoblast cell migration and epithelial-mesenchymal transition (EMT) in hypertensive disorders of pregnancy (HDP) through protein interaction with CDK1.

Hypertensive disorders of pregnancy (HDP) are a common pregnancy disease. NANOG and Cyclin-dependent kinase 1 (CDK1) are essential for regulating the function of cell proliferation and apoptosis. However, the mechanism of action in HDP is yet unclear. The microarray dataset GSE6573 was downloaded from the GEO database. Emt-related gene set was downloaded from Epithelial-Mesenchymal Transition gene database 2.0 were screened differentially expressed genes by bioinformatics analysis. Pathway Commons and Scansite 4.0 databases were used to predict the interaction between proteins. Placental tissue samples were collected from HDP patients and patients with uneventful pregnancies. RT-qPCR, Western blot and immunohistochemistry were used to detect the expression of NANOG, CDK1, MMP-2, MMP-9, EMT markers and the JAK/STAT3 pathway proteins. Transfection NANOG overexpression/knockdown, and CDK1 knockdown into the human chorionic trophoblast cells (HTR-8/Svneo). CCK-8, Transwell and Wound-healing assay were used to evaluate cell proliferation, invasion and migration. CO-IP and GST pull-down assays were used to confirm the protein interaction. A total obtained seven EMT-related differentially expressed genes, wherein NANOG, NODAL and LIN28A had protein interaction. In the HDP patients' tissue found that NANOG and CDK1 had lower expression. NANOG overexpression promoted HTR-8/Svneo proliferation, migration and EMT, while NANOG knockdown had the opposite effect. Further a protein interaction between STAT3 and CDK1 with NANOG. NANOG overexpression downregulated the JAK/STAT3 pathway to promote HTR-8/Svneo proliferation, migration and EMT, which was reversed by CDK1 knockdown. NANOG downregulated the JAK/STAT3 pathway to promote trophoblast cell proliferation, migration and EMT through protein interaction with CDK1.

Arginine and its metabolites stimulate proliferation, differentiation, and physiological function of porcine trophoblast cells through β-catenin and mTOR pathways.

Arginine, which is metabolized into ornithine, proline, and nitric oxide, plays an important role in embryonic development. The present study was conducted to investigate the molecular mechanism of arginine in proliferation, differentiation, and physiological function of porcine trophoblast cells (pTr2) through metabolic pathways. The results showed that arginine significantly increased cell viability (P < 0.05). The addition of arginine had a quadratic tendency to increase the content of progesterone (P = 0.06) and protein synthesis rate (P = 0.03), in which the maximum protein synthesis rate was observed at 0.4 mM arginine. Arginine quadratically increased (P < 0.05) the intracellular contents of spermine, spermidine and putrescine, as well as linearly increased (P < 0.05) the intracellular content of NO in a dose-dependent manner. Arginine showed a quadratic tendency to increase the content of putrescine (P = 0.07) and a linear tendency to increase NO content (P = 0.09) in cell supernatant. Moreover, increasing arginine activated (P < 0.05) the mRNA expressions for ARG, ODC, iNOS and PCNA. Furthermore, inhibitors of arginine metabolism (L-NMMA and DFMO) both inhibited cell proliferation, while addition of its metabolites (NO and putrescine) promoted the cell proliferation and cell cycle, the mRNA expressions of PCNA, EGF and IGF-1, and increased (P < 0.05) cellular protein synthesis rate, as well as estradiol and hCG secretion (P < 0.05). In conclusion, our results suggested that arginine could promote cell proliferation and physiological function by regulating the metabolic pathway. Further studies showed that arginine and its metabolites modulate cell function mainly through β-catenin and mTOR pathways.

Establishment of a placental lncRNA-mRNA expression network for early-onset preeclampsia

BackgroundThis study aimed to establish a placental long non-coding RNA (lncRNA)-mRNA expression network for early-onset preeclampsia (early-onset PE).MethodsThe RNA sequencing data of the GSE14821 dataset were acquired. Several crucial lncRNAs and mRNAs were exerted based on the differential expression analysis of lncRNA and mRNA. By analyzing the differentially expressed lncRNA and mRNA, we constructed a regulatory network to explore the mechanism of the lncRNA in early onset preeclampsia.Results A total of 4436 differentially expressed lncRNAs (DElncRNAs) were identified in early-onset PE placenta samples compared with control placenta samples. Pearson correlation analysis revealed significant correlations between 3659 DElncRNAs and 372 DEmRNAs. KEGG analysis showed that the DEmRNAs were enriched in cytokine-cytokine receptor and hypoxia-inducible factor (HIF)-1 pathways. Several well-known early-onset PE-related mRNAs, such as vascular endothelial growth factor A (VEGFA) and VEGF receptor 1 (FLT1), were involved in the two pathways. Weighted gene co-expression network analysis and cis-regulatory analysis further suggested the involvement of the two pathways and potential DElncRNA-DEmRNA interactions in early-onset PE. Moreover, the upregulation of representative DElncRNAs, such as RP11-211G3.3 and RP11-65J21.3, and DEmRNAs, such as VEGFA and FLT1, were validated in clinical placenta samples from patients with early-onset PE by quantitative reverse transcription PCR. Importantly, overexpression of RP11-65J21.3 significantly promoted the proliferation of HTR-8 trophoblast cells at 72 h after transfection.ConclusionsIn conclusion, we identified placental DElncRNAs of early-onset PE and established a DElncRNA-DEmRNA network that was closely related to the cytokine-cytokine receptor and HIF-1 pathways. Our results provide potential diagnostic markers and therapeutic targets for early-onset PE management.

CPEB2 inhibits preeclampsia progression by regulating SSTR3 translation through polyadenylation

AimsTrophoblast cell dysfunction is one of the important factors leading to preeclampsia (PE). Cytoplasmic polyadenylation element-binding 2 (CPEB2) has been found to be differentially expressed in PE patients, but whether it mediates PE process by regulating trophoblast cell function is unclear. MethodsThe expression of CPEB2 and somatostatin receptor 3 (SSTR3) was detected by quantitative real-time PCR, Western blot (WB) and immunofluorescence staining. Cell functions were analyzed by CCK-8 assay, EdU assay, flow cytometry and transwell assay. Epithelial-mesenchymal transition (EMT)-related protein levels were detected by WB. The interaction of CPEB2 and SSTR3 was confirmed by RIP assay, dual-luciferase reporter assay and PCR poly(A) tail assay. Animal experiments were performed to explore the effect of CPEB2 on PE progression in vivo, and the placental tissues of rat were used for H&E staining, immunohistochemical staining and TUNEL staining. ResultsCPEB2 was lowly expressed in PE patients. CPEB2 upregulation accelerated trophoblast cell proliferation, migration, invasion and EMT, while its knockdown had an opposite effect. CPEB2 bound to the CPE site in the 3′-UTR of SSTR3 mRNA to suppress SSTR3 translation through reducing poly(A) tails. Besides, SSTR3 overexpression suppressed trophoblast cell proliferation, migration, invasion and EMT, while its silencing accelerated trophoblast cell functions. However, these effects could be reversed by CPEB2 upregulation and knockdown, respectively. In vivo experiments, CPEB2 overexpression relieved histopathologic changes, inhibited apoptosis, promoted proliferation and enhanced EMT in the placenta of PE rat by decreasing SSTR3 expression. ConclusionCPEB2 inhibited PE progression, which promoted trophoblast cell functions by inhibiting SSTR3 translation through polyadenylation.

CircAMN1-Mediated Ferroptosis Regulates the Expulsion of Placenta in Trophoblast Cells.

After delivery, the death of trophoblast cells can promote the expulsion of the placenta. Ferroptosis, an iron-dependent programmed cell death, is involved in mammalian development. Circular RNAs are associated with placental development; however, it is unclear whether circular RNAs regulate the expulsion of fetal membranes through ferroptosis. The gene expression profiles in the tail vein blood of Holstein cows with normal and retained placentas were investigated using RNA sequencing and a GSE214588 dataset. circAMN1 and SLC39A8 expression was significantly downregulated in the blood of cows with a retained placenta, whereas miR-205_R-1 expression was significantly upregulated. We validated erastin-induced ferroptosis in trophoblast cells. Transfection with si-circAMN1 and miR-205_R-1 mimic reduced intracellular total iron, Fe2+, and glutathione disulfide levels; increased intracellular glutathione levels and glutathione/glutathione disulfide; and enhanced cell viability in these cells. In contrast, transfection with pcDNA3.1 circAMN1 and an miR-205_R-1 inhibitor promoted ferroptosis. As an miR-205_R-1 sponge, circAMN1 regulated the expression of SLC39A8 to control erastin-induced ferroptosis and regulated the proliferation, invasion, and migration of trophoblast cells. Our findings provide a theoretical basis for studying the mechanism by which programmed cell death regulates fetal membrane expulsion and indicate its potential as a therapeutic target for placenta retention.

Immunohistochemical Investigation of Autophagy in the Uterus during the First Trimester of Pregnancy in Rats

During placental development, autophagy has an important role at the molecular level, especially in cases such as trophoblast cell proliferation and cell death. Abnormal placental development due to trophoblast dysfunction causes serious gynaecological diseases and various fetal malformations. In the study conducted to investigate autophagy on the 5th day of pregnancy, in the pregnant and non pregnant group uterus tissues, uterine glands LC3 and Beclin 1 (+), in the evaluation of myometrium and perimetrium, weak (+) was observed in myometrium cells in pregnancy, while (+) reaction could not be distinguished in perimetrium. In this study, it was concluded that the immunohistochemical increase in LC3 and Beclin 1 intensity in the uterus, especially in the endometrial areas in the first trimester of pregnancy compared to the control group tissues is related to the physiology of pregnancy, homeostasis in pregnancy and hormonal mechanism.

MicroRNA‑155‑5p inhibits trophoblast cell proliferation and invasion by disrupting centrosomal function.

Recurrent miscarriage is used to refer to more than three pregnancy failures before 20 weeks of gestation. Defective trophoblast cell growth and invasion are frequently observed in recurrent miscarriage. Several microRNAs (miRs), including miR‑155‑5p, are aberrantly upregulated in recurrent miscarriage; however, the underlying molecular mechanisms remain unclear. The centrosome orchestrates microtubule networks and coordinates cell cycle progression. In addition, it is a base for primary cilia, which are antenna‑like organelles that coordinate signaling during development and growth. Thus, deficiencies in centrosomal functions can lead to several disease, such as breast cancer and microcephaly. In the present study, the signaling cascades were analyzed by western blotting, and the centrosome and primary cilia were observed and analyzed by immunofluorescence staining. The results showed that overexpression of miR‑155‑5p induced centrosome amplification and blocked primary cilia formation in trophoblast cells. Notably, centrosome amplification inhibited trophoblast cell growth by upregulating apoptotic cleaved‑caspase 3 and cleaved‑poly (ADP‑ribose) polymerase in miR‑155‑5p‑overexpressing trophoblast cells. In addition, overexpression of miR‑155‑5p inhibited primary cilia formation, thereby inhibiting epithelial‑mesenchymal transition and trophoblast cell invasion. All phenotypes could be rescued when cells were co‑transfected with the miR‑155‑5p inhibitor, thus supporting the role of miR‑155‑5p in centrosomal functions. It was also found that miR‑155‑5p activated autophagy, whereas disruption of autophagy via the depletion of autophagy‑related 16‑like 1 alleviated miR‑155‑5p‑induced apoptosis and restored trophoblast cell invasion. In conclusion, the present study indicated a novel role of miR‑55‑5p in mediating centrosomal function in recurrent miscarriage.

N-linked α2,6-sialylation of integrin β1 by the sialyltransferase ST6Gal1 promotes cell proliferation and stemness in gestational trophoblastic disease

IntroductionGestational trophoblastic disease (GTD) encompasses a spectrum of rare pre-malignant and malignant entities originating from trophoblastic tissue, including partial hydatidiform mole, complete hydatidiform mole and choriocarcinoma. β-galactoside α2,6 sialyltransferase 1 (ST6Gal1), the primary sialyltransferase responsible for the addition of α2,6 sialic acids, is strongly associated with the occurrence and development of several tumor types. However, the role of ST6Gal1/α2,6 -sialylation of trophoblast cells in GTD is still not well understood. MethodsThe expression of ST6Gal1 was investigated in GTD and human immortalized trophoblastic HTR-8/SVneo cells and human gestational choriocarcinoma JAR cells. We evaluated the effect of ST6Gal1 on proliferation and stemness of trophoblastic cells. We also examined the effect of internal miR-199a-5p on ST6Gal1 expression. The role of ST6Gal1 in regulating α2,6-sialylated integrin β1 and its significance in the activation of integrin β1/focal adhesion kinase (FAK) signaling pathway were also explored. ResultsST6Gal1 was observed to be highly expressed in GTD. Overexpression of ST6Gal1 promoted the proliferation and stemness of HTR-8/SVneo cells, whereas knockdown of ST6Gal1 suppressed the viability and stemness of JAR cells. MiR-199a-5p targeted and inhibited the expression of ST6Gal1 in trophoblastic cells. In addition, we revealed integrin β1 was highly α2,6-sialylated in JAR cells. Inhibition of ST6Gal1 reduced α2,6-sialylation on integrin β1 and suppressed the integrin β1/FAK pathway in JAR cells, thereby affecting its biological functions. DiscussionThis study demonstrated that ST6Gal1 plays important roles in promoting proliferation and stemness through the integrin β1 signaling pathway in GTD. Therefore, ST6Gal1 may have a potential role in the occurrence and development of GTD.

Low levels of nicotine and cotinine but not benzo[a]pyrene induce human trophoblast cell proliferation

E-cigarettes use constitutes a source of thirdhand nicotine exposure. The increasing use of electronic cigarettes in homes and public places increases the risk of exposure of pregnant women to thirdhand nicotine. The effects of exposure of pregnant women to very low levels of nicotine have not been studied in humans but detrimental in experimental animals. The objective of this study is to investigate the effect of nanomolar concentrations of nicotine and its metabolite cotinine on the proliferation of JEG-3, a human trophoblast cell line. We also studied the proliferative effect of nanomolar concentrations of benzo[a]pyrene (B[a]P), a polycyclic hydrocarbon in tobacco smoke, for comparison.We treated JEG-3 cells in culture with nanomolar concentrations of nicotine, cotinine, and B[a]P. Their effect on cell proliferation was determined, relative to untreated cells, by MTT assay. Western blotting was used to assess the mitogenic signaling pathways affected by nicotine and cotinine.In contrast to the inhibitory effects reported with higher concentrations, we showed that nanomolar concentrations of nicotine and cotinine resulted in significant JEG-3 cell proliferation and a rapid but transient increase in levels of phosphorylated ERK and AKT, but not STAT3. Biphasic, non-monotonic effect on cell growth is characteristic of endocrine disruptive chemicals like nicotine. The mitogenic effects of nicotine and cotinine potentially contribute to increased villous epithelial thickness, seen in placentas of some smoking mothers. This increases the diffusion distance for oxygen and nutrients between mother and fetus, contributing to intrauterine growth restriction in infants of smoking mothers.

Circ_0007445 inhibits trophoblast cell proliferation, migration and invasion by mediating the miR-4432/HTRA1 axis in preeclampsia.

: Circular RNAs (circRNAs) have been shown to be extensively involved in preeclampsia progression. At present, the role of circ_0007445 in preeclampsia progression is not clear. A total of 30 preeclampsia patients and 30 normal pregnant women were recruited in our study. The function of trophoblast cells was explored to clarify the role and mechanism of circ_0007445 on the preeclampsia progression. The expression of circ_0007445, microRNA (miR)-4432 and high temperature requirement A1 (HTRA1) was analyzed by quantitative real-time PCR. The proliferation, migration and invasion of trophoblast cells were determined by cell counting kit 8 assay, EdU assay, colony formation assay, flow cytometry, and transwell assay. Protein expression was examined by western blot analysis. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay were used to assess RNA interaction relationships. Our data suggested that circ_0007445 had increased expression in preeclampsia patients. Knockdown of circ_0007445 enhanced trophoblast cell proliferation, migration and invasion. MiR-4432 was lowly expressed in preeclampsia patients, and it could be sponged by circ_0007445. MiR-4432 inhibitor overturned the promotion effects of circ_0007445 knockdown on trophoblast cell functions. HTRA1 was highly expressed in preeclampsia patients, and it could be targeted by miR-4432. HTRA1 overexpression could also reverse the proliferation, migration and invasion of trophoblast cells promoted by miR-4432 mimic. In addition, circ_0007445 positively regulated HTRA1 through targeting miR-4432. :Our results suggested that circ_0007445 facilitated the development of preeclampsia by suppressing trophoblast cell function through miR-4432/HTRA1 axis.

Role of increased IGFBP2 in trophoblast cell proliferation and recurrent spontaneous abortion development: A pilot study.

Recurrent spontaneous abortion (RSA) is a serious condition that adversely affects women's health. Differentially expressed proteins (DEPs) in plasma of patients experiencing RSA is helpful to find new therapeutic targets and identified with mass spectrometry. In 57 DEPs, 21 were upregulated and 36 were downregulated in RSA. Gene ontology analyses indicated that identified DEPs were associated with cell proliferation, including significantly downregulated insulin-like growth factor binding protein 2 (IGFBP2). Immunohistochemical result using clinical decidual tissues also showed that IGFBP2 expression was significantly decreased in RSA trophoblasts. Cell proliferation assay indicated that IGFBP2 treatment increased the proliferation and mRNA expressions of PCNA and Ki67 in trophoblast cells. Transcriptome sequencing experiments and Kyoto Encyclopedia of Genes and Genomes analyses revealed that gene expression for components in PI3K-Akt pathway in trophoblasts was significantly upregulated following IGFBP2 treatment. To confirm bioinformatics findings, we did cell-based experiments and found that treatment of inhibitors for insulin-like growth factor (IGF)-1 receptor-PI3K-Akt pathway significantly reduced IGFBP2-induced trophoblast cell proliferation and mRNA expressions of PCNA and Ki67. Our findings suggest that IGFBP2 may increase trophoblast proliferation through the PI3K-Akt signaling pathway to affect pregnancy outcomes and that IGFBP2 may be a new target for future research and treatment of RSA.

The metabolic role of the CD73/adenosine signaling pathway in HTR-8/SVneo cells: A Double-Edged Sword?

The ecto-5′-nucleotidase (CD73)/adenosine signaling pathway has been reported to regulate tumor epithelial-mesenchymal transition (EMT), migration and proliferation. However, little is known about the metabolic mechanisms underlying its role in trophoblast proliferation and migration. In this study, we aimed to investigate the metabolic role of the CD73/adenosine signaling pathway on the proliferation and migration of trophoblast. We found that CD73 levels were upregulated in preeclamptic placentas compared with the placentas of normotensive pregnant women. EMT and migration of HTR-8/SVneo cells were enhanced when treated with a CD73 inhibitor (100 μM) in vitro. Conversely, excessive adenosine (25 or 50 μM) suppressed trophoblast cell EMT, migration and proliferation. RNA-seq, metabolomics and seahorse findings showed that adenosine treatment resulted in increased expression of PDK1, suppression of aerobic respiration, glycolysis and amino acids synthesis, as well as increased utilization of short-chain fatty acids (SCFAs). Furthermore, the 13C-adenosine isotope tracking experiment demonstrated that adenosine served as a carbon source for the tricarboxylic acid (TCA) cycle. Our results reveal the role of adenosine in regulating trophoblast energy metabolism is like a double-edged sword - either inhibiting aerobic respiration or supplementing carbon sources into metabolic flux. CD73/adenosine signaling regulated trophoblast EMT, migration, and proliferation by modulating energy metabolism. This study indicates that CD73/adenosine signaling potentially plays a role in the occurrence of placenta-derived diseases, including preeclampsia.

Exploring the clinical and cellular mechanisms of LncRNA-KCNQ1OT1/miR-29a-3p/SOCS3 molecular axis in cases of unexplained recurrent spontaneous abortion

Objective The objective of this study is to explore the functions and mechanisms of the LncRNA-KCNQ1OT1/miR-29a-3p/SOCS3 molecular pathway in the context of unexplained recurrent spontaneous abortion (URSA). Methods We conducted qRT-PCR to assess the levels of LncRNA-KCNQ1OT1, miR-29a-3p, and SOCS3 in both abortion tissues from women who experienced URSA and healthy early pregnant women. A dual-luciferase assay was employed to investigate whether miR-29a-3p targets SOCS3. Furthermore, RNA IP and RNA Pull-Down assays were employed to confirm the interaction between KCNQ1OT1 and SOCS3 with miR-29a-3p. RNA FISH was used to determine the cellular localization of KCNQ1OT1. Additionally, trophoblast cells (HTR8/SVneo) were cultured and the CCK-8 assay was utilized to assess cell proliferation, while flow cytometry was employed to analyze cell apoptosis. Results Compared to abortion tissues obtained from healthy early pregnant individuals, those from women who experienced URSA displayed a notable downregulation of KCNQ1OT1 and SOCS3, accompanied by an upregulation of miR-29a-3p. Suppression of KCNQ1OT1 resulted in the inhibition of cell proliferation and the facilitation of apoptosis in HTR8/SVneo cells. Our findings suggest that KCNQ1OT1 may exert a regulatory influence on SOCS3 through a competitive binding mechanism with miR-29a-3p. Notably, KCNQ1OT1 exhibited expression in both the cytoplasm and nucleus, with a predominant localization in the cytoplasm. Furthermore, we observed a negative regulatory relationship between miR-29a-3p and SOCS3, as the miR-29a-3p mimic group demonstrated significantly reduced cell proliferation and an increased rate of apoptosis when compared to the negative control (NC mimic) group. Additionally, the SOCS3 Vector group exhibited a substantial improvement in proliferation capability and a marked reduction in the apoptosis rate in comparison to the NC Vector group. The miR-29a-3p mimic + SOCS3 Vector group demonstrated a remarkable enhancement in proliferation and a reduction in apoptosis when compared to the miR-29a-3p mimic group. Conclusion The competitive binding of miR-29a-3p to LncRNA-KCNQ1OT1 appears to result in the elevation of SOCS3 expression, consequently fostering the proliferation of trophoblast cells while concomitantly suppressing apoptosis.

Implications for miR-339-5p regulation of trophoblast proliferation and migration in placentas associated with porcine intrauterine growth retardation using integrated transcriptome sequencing analysis

Placental dysfunction is considered as one of the main etiologies of fetal intrauterine growth retardation (IUGR). MicroRNAs (miRNAs) have been demonstrated to be a vital epigenetic modification involved in regulating the placental function and pregnancy outcomes in mammals. However, the mechanisms underlying placenta-specific miRNAs involved in the occurrence and development of pig IUGR remain unclear. In this work, we compared the placental morphologies of piglets with IUGR and normal birth weight (NBW) by using histomorphological analysis and performed a miRNA–mRNA integrative analysis of the gene expression profiles of IUGR and NBW placentas through RNA sequencing. We also investigated the role of differentially expressed ssc-miR-339-5p/GRIK3 through an in vitro experiment on porcine trophoblast cells (PTr2). IUGR piglets had significantly lower birth weight, placental weight, placental efficiency, and placental villus and capillary densities compared with the NBW piglets (P < 0.05). A total of 81 differentially expressed miRNAs and 726 differentially expressed genes in the placentas were screened out between the IUGR and NBW groups. The miRNA–mRNA interaction networks revealed the key core miRNA (ssc-miR-339-5p) and its corresponding target genes. Subsequently, we found that upregulation of ssc-miR-339-5p significantly inhibited the migration and proliferation of PTr2 cells (P < 0.05). The dual-luciferase reporter system showed that GRIK3 was the target gene of ssc-miR-339-5p, and the transcription level of GRIK3 may be negatively regulated by ssc-miR-339-5p. Additionally, overexpression of ssc-miR-339-5p significantly increased (P < 0.05) the mRNA expression levels of genes involved in the cytokine–cytokine receptor interaction pathway. These results indicate that ssc-miR-339-5p may affect the migration and proliferation of trophoblast cells by regulating the expression of GRIK3 and altering the placental inflammatory response, resulting in a suboptimal morphology and function of the placenta and the development of pig IUGR.

Circ_0001861 facilitates trophoblast cell proliferation, migration, invasion and epithelial-mesenchymal transition via the miR-296-5p/forkhead box protein 1 pathway in preeclampsia.

Preeclampsia (PE) is one of the leading causes of maternal mortality and placental trophoblastic disorders. Recent studies reported that circular RNAs (circRNAs) were involved in PE pathogenesis. However, the role of circ_0001861 in PE progression is largely unknown. The RNA expression of circ_0001861, forkhead box protein 1 (FOXP1) and microRNA-296-5p (miR-296-5p) was detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Western blot assay was performed to examine the protein levels of FOXP1 and epithelial-mesenchymal transition (EMT) markers. Cell viability, proliferation, migration and invasion were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and transwell assays. Luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay were conducted to explore the interaction between miR-296-5p and circ_0001861 or FOXP1. Circ_0001861 and FOXP1 were downregulated but miR-296-5p was upregulated in PE placenta. Upregulation of circ_0001861 facilitated trophoblast cell proliferation, migration, invasion and EMT. Mechanistically, circ_0001861 sponged miR-296-5p to elevate FOXP1 expression, thus promoting trophoblast cell progression. The circ_0001861/miR-296-5p/FOXP1 axis plays a critical role in trophoblast cell proliferation, migration, invasion and EMT, which may provide a novel insight into developing potential therapeutic targets for PE.

Oleuropein Stimulates Migration of Human Trophoblast Cells and Expression of Invasion-Associated Markers.

Successful pregnancy establishment requires highly synchronized cross talk between the invasive trophoblast cells and the receptive maternal endometrium. Any disturbances in this tightly regulated process may lead to pregnancy complications. Local factors such as nutrients, hormones, cytokines and reactive oxygen species modulate the invasion of extravillous trophoblasts through critical signaling cascades. Epidemiological studies strongly indicate that a Mediterranean diet can significantly impact molecular pathways during placentation. Therefore, the aim of the current study was to examine whether oleuropein (OLE), one of the main compounds of the Mediterranean diet, may influence trophoblast cell adhesion and migration, as well as the expression of invasion-associated molecular markers and inflammatory pathways fostering these processes. HTR-8/SVneo cells were incubated with OLE at selected concentrations of 10 and 100 µM for 24 h. Results showed that OLE did not affect trophoblast cell viability, proliferation and adhesion after 24 h in in vitro treatment. The mRNA expression of integrin subunits α1, α5 and β1, as well as matrix-degrading enzymes MMP-2 and -9, was significantly increased after treatment with 10 µM OLE. Furthermore, OLE at a concentration of 10 µM significantly increased the protein expression of integrin subunits α1 and β1. Also, OLE inhibited the activation of JNK and reduced the protein expression of COX-2. Finally, a lower concentration of OLE 10 µM significantly stimulated migration of HTR-8/SVneo cells. In conclusion, the obtained results demonstrate the effects of OLE on the function of trophoblast cells by promoting cell migration and stimulating the expression of invasion markers. As suggested from results, these effects may be mediated via inhibition of the JNK signaling pathway.

METTL14-mediated lncRNA XIST silencing alleviates GDM progression by facilitating trophoblast cell proliferation and migration via the miR-497-5p/FOXO1 axis.

Gestational diabetes mellitus (GDM),a prevalent complication during the gestation period, has been linked to impaired proliferation and migration of trophoblasts causing placental maldevelopment. We previously found that lncRNA X-inactive specific transcript (XIST)played an essential role in GDM progression. Here, we investigated the precise biological functions as well as the upstream and downstream regulatory mechanisms of XIST in GDM. We found that XISTand forkheadbox O1 (FOXO1) were conspicuously upregulated and miR-497-5p and methyltransferase-like 14 (METTL14) were downregulated in the placentas of GDM patients. XIST silencing facilitated proliferation and migration and inhibited cell apoptosis and cell cycle arrest in HG-cultured HTR8/SVneo cells. METTL14 inhibited XIST expression through m6A methylation modification. XIST overexpression abrogated the positive effect of METTL14 overexpression on HG-cultured HTR8/SVneo cell progression. MiR-497-5p and FOXO1 are downstream regulatory genes of XIST in HTR8/SVneo cells. Reverse experiments illustrated that XIST mediated HTR8/SVneo cell functions by regulating the miR-497-5p/FOXO1 axis. Additionally, XIST silencing augmented glucose tolerance and alleviated fetal detrimental changes in GDM rats. To conclude, METTL14-mediated XIST silencing facilitated proliferation and migration and inhibited cell apoptosis and cell cycle arrest in HG-cultured HTR8/SVneo cells via the miR-497-5p/FOXO1 axis, thereby alleviating GDM progression in rats.