LncRNA MALAT1 promotes decidualization of endometrial stromal cells via sponging miR-498-3p and targeting histone deacetylase 4.

Decidualization of human endometrial stromal cells (hESCs) is important for the maintenance of a successful pregnancy. Histone deacetylase 4 (HDAC4) was reported to be involved in the dysfunction of decidua-derived mesenchymal stem cells. However, the role of HDAC4 underlying decidualization of hESCs remains unclear. We intended to explore the function and molecular mechanism of HDAC4 in hESCs. In vitro expansion of hESCs using a serum-free medium was used to confirm the characteristics of hESCs. Gene expression in hESCs was evaluated by reverse transcription-quantitative polymerase chain reaction. CCK-8 assay, TUNEL staining, flow cytometry analysis, and Western blot analysis were performed to test the effects of HDAC4 and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on hESCs. RNA pull-down and luciferase reporter assays were performed to validate the relationship between genes. In this study, the characteristics of hESCs were sustained in serum-free medium during a process of propagation. HDAC4 knockdown suppressed hESCs viability and promoted hESCs apoptosis. HDAC4 was targeted by miR-498-3p in hESCs. MALAT1 bound with miR-498-3p in hESCs. HDAC4 expression was positively regulated by MALAT1 and negatively regulated by miR-498-3p in hESCs. HDAC4 upregulation countervailed the effects of MALAT1 silencing on hESCs proliferation, apoptosis, and decidualization of hESCs. Overall, MALAT1 facilitated the decidualization of hESCs via binding with miR-498-3p and upregulating HDAC4, which might provide a new direction for the maintenance of a successful pregnancy.

Increased METTL3-mediated m6A methylation inhibits embryo implantation by repressing HOXA10 expression in recurrent implantation failure.

BACKGROUND: Recurrent implantation failure (RIF) is a major limitation of assisted reproductive technology, which is associated with impaired endometrial receptivity. Although N6-methyladenosine (m6A) has been demonstrated to be involved in various biological processes, its potential role in the endometrium of women with RIF has been poorly studied. METHODS: Global m6A levels and major m6A methyltransferases/demethylases mRNA levels in mid-secretory endometrium from normal and RIF women were examined by colorimetric m6A quantification strategy and quantitative real-time PCR, respectively. The effects of METTL3-mediated m6A modification on embryo attachment were evaluated by an vitro model of a confluent monolayer of Ishikawa cells co-cultured with BeWo spheroids, and the expression levels of homeo box A10 (HOXA10, a well-characterized marker of endometrial receptivity) and its downstream targets were evaluated by quantitative real-time PCR and Western blotting in METTL3-overexpressing Ishikawa cells. The molecular mechanism for METTL3 regulating HOXA10 expression was determined by methylated RNA immunoprecipitation assay and transcription inhibition assay. RESULTS: Global m6A methylation and METTL3 expression were significantly increased in the endometrial tissues from women with RIF compared with the controls. Overexpression of METTL3 in Ishikawa cells significantly decreased the ration of BeWo spheroid attachment, and inhibited HOXA10 expression with downstream decreased ß3-integrin and increased empty spiracles homeobox 2 expression. METTL3 catalyzed the m6A methylation of HOXA10 mRNA and contributed to its decay with shortened half-life. Enforced expression of HOXA10 in Ishikawa cells effectively rescued the impairment of METTL3 on the embryo attachment in vitro. CONCLUSION: Increased METTL3-mediated m6A modification represents an adverse impact on embryo implantation by inhibiting HOXA10 expression, contributing to the pathogenesis of RIF.

Krüppel-like factor 12 is a novel negative regulator of forkhead box O1 expression: a potential role in impaired decidualization.

BACKGROUND: Decidualization is a prerequisite for successful implantation and the establishment of pregnancy. Krüppel-like factor 12 (KLF12) is a negative regulator of endometrial decidualization in vitro. We investigated whether KLF12 was associated with impaired decidualization under conditions of repeated implantation failure (RIF). METHODS: Uterine tissues were collected from a mouse model of early pregnancy and artificial decidualization for immunohistochemistry, Western blot and real-time PCR analysis. Reporter gene assays, chromatin immunoprecipitation-PCR and avidin-biotin conjugate DNA precipitation assays were performed to analyze the transcriptional regulation of forkhead box O1 (FOXO1) by KLF12. Furthermore, the protein levels of KLF12 and FOXO1 in patients with RIF were analyzed by Western blot and immunohistochemistry. RESULTS: KLF12 led to defective implantation and decidualization in the mouse uterine model of early pregnancy and artificial decidualization by directly binding to the FOXO1 promoter region and inhibiting its expression in human endometrial stromal cells. Elevated KLF12 expression was accompanied by decreased FOXO1 expression in the endometria of patients with RIF. CONCLUSIONS: As a novel regulator, KLF12 predominantly controls uterine endometrial differentiation during early pregnancy and leads to implantation failure.

Activation of matrix metalloproteinase-26 by HOXA10 promotes embryo adhesion in vitro.

Successful embryonic implantation requires an effective maternal-embryonic molecular dialogue. However, the detailed mechanisms of epithelial-embryo adhesion remain poorly understood. Here, we report that matrix metalloproteinase-26 (MMP-26) is a novel downstream target gene of homeobox a 10 (HOXA10) in human endometrial cells. HOXA10 binds directly to a conserved TTAT unit (-442 to -439) located within the 5' regulatory region of the MMP-26 gene and regulates the expression and secretion of MMP-26 in a concentration-dependent manner. Moreover, the adenovirus-mediated overexpression of MMP-26 in Ishikawa cells markedly increased BeWo spheroid adhesion. An antibody blocking assay further demonstrated that the promotion of BeWo spheroid adhesion by HOXA10 and MMP-26 was significantly inhibited by pre-treatment with a specific antibody against MMP-26. These results demonstrate that the HOXA10-mediated expression of MMP-26 promotes embryo adhesion during the process of embryonic implantation.

Risk factors associated with cesarean section and adverse fetal outcomes in intrahepatic cholestasis of pregnancy.

Background: To determine the risk factors for cesarean section (CS) and adverse fetal outcomes (AFOs) in patients with intrahepatic cholestasis of pregnancy (ICP) based on the severity of maternal hypercholanemia. Methods: A hospital-based retrospective cohort study was performed between January 1, 2015, and December 31, 2019. A total of 227 nulliparous women with a singleton fetus complicated by ICP were included. The patients were divided into two groups according to the levels of total bile acids, that is, mild (10 µmol/L < total bile acids < 40 µmol/L) and severe (≥40 µmol/L). The patients' clinical characteristics and fetal outcomes were assessed. Results: Among the 227 eligible women, 177 (78.0%) were allocated to the mild group and 50 (22.0%) were in the severe group. Women with severe ICP also had a significantly higher incidence of planned and unplanned CS compared with mild ICP subjects (52.0% vs. 23.7% and 22.0% vs. 6.8%, respectively; p < 0.001). The indications for CS showed that fetal intolerance (65.4% vs. 14.3%) was higher in severe ICP compared with mild ICP (p < 0.001). Severe ICP was associated with an increased risk of preterm delivery (p < 0.001), low birthweight (p = 0.001), and neonatal intensive care unit (NICU) admission (p < 0.001). Women with severe ICP (OR 6.397, 95%CI 3.041-13.455, p < 0.001) or preeclampsia (OR 12.434, 95%CI 5.166-29.928, p < 0.001) had increased risks of AFOs compared to controls. Conclusions: Severe ICP and preeclampsia are associated with a higher incidence of AFOs.

Label-free proteomic analysis and functional analysis in patients with intrauterine adhesion.

Intrauterine adhesion (IUA) is one of the principal causes of secondary infertility in women of reproductive age, which seriously affects female reproductive function and quality of life. In recent years, the incidence of IUA has been increasing year by year, but its pathological mechanism has not yet been clarified. This study intended to reveal the pathogenesis of IUA and find new therapeutic targets by analyzing the proteomic differences between intrauterine adhesion tissues and normal human endometrial tissues. In the label-free quantitative proteomics, we identified 789 up-regulated differentially expressed proteins (DEPs) and 539 down-regulated DEPs. These DEPs were further analyzed by Gene Ontology (GO) annotation and enrichment analysis, Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis to preliminarily clarify the biomarkers involved in the pathogenesis of the IUA. The DEPs were further verified by parallel reaction monitoring (PRM) to confirm the results of proteomics. Finally, 7 target proteins may be candidates for treatment and elucidating the pathophysiology of IUA. SIGNIFICANCE: IUA is a fertility complication, which has increasing incidence recently. Until now, only a little research paid attention to the proteomic changes of IUA. This is the first study focused on the comparative analysis of endometrial tissue between IUA patients and normal women. We found 7 key proteins that may become the potential biomarkers of IUA.

Upregulation of METTL14 contributes to trophoblast dysfunction by elevating FOXO3a expression in an m6A-dependent manner.

INTRODUCTION: Preeclampsia, a specific complication of pregnancy, is a leading cause of perinatal and maternal mortality worldwide. N6-methyladenosine (m6A) is a prevalent and reversible modification of mammalian mRNAs, and is known to play an important role in various physiological and pathological processes. However, little is known about its possible effects on trophoblasts in preeclampsia. METHODS: Colorimetric RNA m6A methylation quantification assay and dot blotting were used to assess the levels of global RNA m6A modification in placental tissues collected from females with normal pregnancy and preeclampsia, while the mRNA levels of major m6A methyltransferases/demethylases were investigated by quantitative real-time polymerase chain reaction. The effects of methyltransferase-like 14 (METTL14) on trophoblasts were evaluated using cell counting kit-8, transwell invasion assay, autophagic flux assay, and Annexin V/propidium iodide apoptosis assay. The molecular mechanism underlying the regulation of forkhead box O3a (FOXO3a) expression by METTL14 was determined using methylated RNA immunoprecipitation and transcription inhibition assays. RESULTS: Global RNA m6A methylation and METTL14 expression were significantly increased in placental tissues obtained from patients with preeclampsia. In vitro studies showed that overexpression of METTL14 in HTR-8/SVneo cells inhibited trophoblast proliferation and invasion, but induced trophoblast autophagy and apoptosis. We further demonstrated that METTL14 epigenetically elevated FOXO3a expression via an m6A-dependent mechanism. FOXO3a inhibition effectively prevented the impairment of trophoblast proliferation and invasion, and diminished the induction of trophoblast autophagy and apoptosis in METTL14-overexpressing HTR-8/SVneo cells. DISCUSSION: Increased METTL14-mediated m6A modification results in an adverse impact on trophoblast function by elevating FOXO3a expression.

Up-regulation of PTEN via LPS/AP-1/NF-κB pathway inhibits trophoblast invasion contributing to preeclampsia.

Preeclampsia, a pregnancy-specific disorder, is characterized by abnormal vascular remodeling of the spiral arteries due to deficient trophoblast invasion. Lipopolysaccharide (LPS) administration to pregnant rats on day 5 of pregnancy could induce excessive immune response at the maternal-fetal interface contributing to poor early placentation that culminate in the preeclampsia-like syndrome. Furthermore, the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a critical tumor suppressor, is markedly increased in the placentas of patients with preeclampsia. Our goal was to investigate the association of PTEN with preeclampsia and the pathways involved using human-trophoblast-derived cell line (HTR-8/SVneo) stimulated with LPS. We found that the expression of PTEN was significantly increased in the placentas of patients with severe preeclampsia and preeclamptic rat model induced by LPS. In vitro trophoblasts results showed that significantly differential expression of PTEN with corresponding changes in JunB/FosB (subunits of AP-1) and NF-κB activity after LPS stimulation. We further demonstrated that LPS-induced PTEN expression was dependent on AP-1 and NF-κB in trophoblasts. The trophoblasts with enforced expression of PTEN showed a reduced ability to invasion. Taken together, LPS may undermine remodelling of the human-trophoblast-derived HTR-8/SVneo cells by increasing PTEN, acting in part through the AP-1 and NF-κB pathways.

Knocking down of LINC01220 inhibits proliferation and induces apoptosis of endometrial carcinoma through silencing MAPK11.

Background: Endometrial carcinoma (EC) still threatens the health of women. Thus, to explore how long intergenic non-protein coding RNA 01220 regulates the development of EC.Methods: Whole genome expression profile data of EC and paracancerous tissues in TCGA database were downloaded. LINC01220 expression in EC and paracancerous tissues of patients in our hospital were detected by qRT-PCR. Furthermore, the relationship between LINC01220 expression and clinicopathological features of EC patients was analyzed. After transfection with sh-LINC01220 and pcDNA-MAPK11 (mitogen-activated protein kinase) in EC cells, proliferative, colony formation abilities and apoptosis were determined by cell counting kit-8 (CCK-8), colony formation assay and flow cytometry, respectively. Western blot was conducted to determine the regulatory role of LINC01220 on MAPK11.Results: TCGA data showed that LINC01220 expression is markedly higher in EC tissues than that of paracancerous tissues, which was consistent without detection in EC patients of our hospital. LINC01220 expression was positively correlated to pathological grade and International Federation of Gynecology and Obstetrics (FIGO) stage of EC patients. After knockdown of LINC01220 in EC cells, proliferative and colony formation abilities decreased, whereas apoptotic rate increased. Cor function analysis revealed the positive correlation between LINC01220 and MAPK11 in EC. MAPK11 expression was regulated by LINC01220 in EC cells. Overexpression of MAPK11 can reverse the tumor suppressing effect of LINC01220 on EC.Conclusions: LINC01220 promotes EC development by stimulating proliferation and inhibiting apoptosis of EC cells through up-regulating MAPK11.

miR-133b Reverses the Hydrosalpinx-induced Impairment of Embryo Attachment Through Down-regulation of SGK1.

CONTEXT: Hydrosalpinx impairs endometrial receptivity and embryo implantation. However, the exact underlying mechanism remains elusive. OBJECTIVE: This study aimed to explore how an miR-133b-mediated mechanism controls endometrial receptivity and embryo attachment in the endometrium of women with hydrosalpinx. DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: Ishikawa cells were treated with hydrosalpinx fluid (HF) from infertile patients and cultured for in vitro analysis. The attachment rates of BeWo spheroids and mouse embryos to Ishikawa cells were assayed. PRIMARY OUTCOME MEASURE: miR-133b, serum and glucocorticoid-regulated kinase 1 (SGK1), and homeobox A10 (HOXA10) expression levels were evaluated by quantitative real-time PCR and Western blot assays. RESULTS: The expression of miR-133b and HOXA10 was significantly down-regulated, whereas the miR-133b target gene SGK1 was up-regulated in mid-secretory endometrial tissues of women with hydrosalpinx and in HF-treated Ishikawa cells. Moreover, hydrosalpinx inhibited miR-133b expression through the activation of nuclear factor κB/p65, and SGK1 decreased miR-133b-induced HOXA10 expression by phosphorylating cAMP responsive element binding protein in Ishikawa cells. Our results also showed that miR-133b and HOXA10 contributed to BeWo spheroid adhesiveness, whereas SGK1 inhibited BeWo spheroid attachment to Ishikawa cells. Importantly, miR-133b overexpression reversed the HF-mediated impairment of embryo attachment in vitro. CONCLUSIONS: miR-133b directly targets SGK1 to reverse the hydrosalpinx-induced down-regulation of HOXA10 and to attenuate the impairment of embryo attachment in vitro.