Endometrial Cell Proliferation Research Articles

Ageing, a modulator of human endometrial stromal cell proliferation and decidualization: a role for implantation?

Research questionDoes ageing affect endometrial stromal cell function and gene expression involved in decidualization? DesignStromal cells were isolated and cultured (98% purity) from pipelle endometrial biopsies obtained from female donors, at the proliferative phase of the menstrual cycle. Initially, 28 samples were collected (age range 25–46 years). These samples were divided into two groups: 25–35 years and 36–46 years. Cell proliferation assays were carried out to determine changes in stromal cell proliferation, in vitro, between the two groups. In addition, mRNA and protein expression of decidualization factors, BMP2 and STAT3, were analysed for the same age groups and samples using real-time polymerase chain reaction and western blot analysis, respectively. Finally, another 12 pipelle endometrial biopsies (age range 25–46 years) were used in separate in-vitro decidualization experiments. The mRNA expression of decidualization markers, prolactin and IGFBP-1 were analysed in cultured stromal cells after adding 8-bromo-cAMP. ResultsA statistically significant decrease was observed in stromal cell proliferation with increasing age (P = 0.0006). Messenger RNA expression of BMP2 and STAT3 were found to decrease (P = 0.0167; P = 0.0037, respectively) in the older age group. In addition, BMP2 and STAT3 protein expression between the samples analysed changed significantly (P = 0.0085; P = 0.0463, respectively) with increasing age. In-vitro induced decidualization experiments showed significant changes in stromal cell mRNA expression of decidualization markers (IGFBP1 and prolactin) between different age groups. ConclusionAgeing affected endometrial cell function and gene expression. Changes in cell function and expression of associated molecules that differ in the ageing endometrium can help understand the causes of infertility.

Comparative proteomics identify HSP90A, STIP1 and TAGLN-2 in serum extracellular vesicles as potential circulating biomarkers for human adenomyosis.

Extracellular vesicles (EVs) carry specific proteins involved in intercellular communication. EVs with different protein contents are released into circulation in different diseases. Recent studies have identified proteins in adenomyosis (AM)-derived EVs (AMEVs) from blood as biomarkers for this disease. AM is an extension of endometrial tissue into the uterine myometrium. Magnetic resonance imaging (MRI) is the most accurate imaging tool for identifying adenomyosis. Therefore, the present study aimed to investigate the role of EVs in diagnosing AM. In the present study, tissue AMEVs (T-AMEVs) were isolated from lesion homogenates of patients with adenomyosis, and blood AMEVs (B-AMEVs) were isolated from peripheral blood of patients with AM via differential centrifugation and density gradient centrifugation. T-AMEVs and B-AMEVs were characterized by electron microscopy, western blotting and mass spectrometry and analysed using FunRich3.1.3 software. T-AMEVs (average diameter, 150.9±102.2 nm) and B-AMEVs (194.1±66.81 nm) expressed the CD9, CD63 and flotillin-2 EV markers. A total of 211 proteins expressed in T-AMEVs and B-AMEVs overlapped with Vesiclepedia database entries, including 2 epithelial-to-mesenchymal transition (EMT)-associated proteins and 6 invasion-associated proteins. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these 211 proteins were associated with the ‘regulation of cell morphogenesis’ and ‘cytoskeletal organization’ terms, as well as the PPAR and HIF-1 signalling pathways, which are related to the proliferation and metastasis of endometrial cells that cannot invade the myometrium under normal circumstances. Among the 211 proteins, HSP90A, STIP1 and TAGLN-2 were expressed in T-AMEVs and B-AMEVs, but not in serum EVs of women without adenomyosis/endometriosis, and these proteins might be the potential biomarkers for adenomyosis. These findings provide insights into the molecular features of adenomyosis and the new candidate biomarkers for diagnosis.

Long non-coding RNA DHRS4 antisense RNA 1 inhibits ectopic endometrial cell proliferation, migration, and invasion in endometriosis by regulating microRNA-139-5p expression

ABSTRACT Endometriosis is an estrogen-dependent chronic gynecological syndrome. Recent studies have shown that long non-coding RNAs participate in the pathogenesis and development of endometriosis. This study aimed to explore the mechanisms of DHRS4 antisense RNA 1 (DHRS4-AS1) in endometriosis. Dual-luciferase reporter assays were conducted to determine the relationship between DHRS4-AS1, microRNA (miR)-139-5p, and arrestin domain-containing 3 (ARRDC3). Furthermore, the expression of DHRS4-AS1 and miR-139-5p in ectopic endometrial stromal cells (EC-ESCs) and endometriosis tissues was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry, and Transwell assays were performed to evaluate the proliferation, apoptosis, and migration and invasion of EC-ESCs, respectively. Western blotting and RT-qPCR were further utilized to determine cleaved-Caspase 3, Caspase 3, and matrix metalloproteinase 9 (MMP-9) expression levels. Compared with the EN group, DHRS4-AS1 levels were lower and miR-139-5p levels were higher in EC-ESCs and tissues obtained from patients with endometriosis. Functional assays validated that DHRS4-AS1 targets miR-139-5p, with ARRDC3 being a downstream target of miR-139-5p. Rescue experiments demonstrated that DHRS4-AS1 inhibited EC-ESC proliferation, migration, and invasion, but promoted apoptosis, by targeting miR-139-5p in endometriosis. cleaved-Caspase3 expression level and the cleaved-Caspase 3/Caspase 3 ratio increased, while the expression levels of MMP-9 decreased, after transfection with DHRS4-AS1 overexpression plasmids; however, the effects induced by DHRS4-AS1 overexpression could be partially reversed by co-transfection with the miR-139-5p mimic. The current study demonstrates that the DHRS4-AS1/miR-139-5p/ARRDC3 axis participates in the regulation of EC-ESC function.

Chemerin Effect on the Endometrial Proteome of the Domestic Pig during Implantation Obtained by LC-MS/MS Analysis.

Chemerin (CHEM) is a hormone mainly expressed in adipocytes involved in the regulation of energy homeostasis and inflammatory response. CHEM expression has been demonstrated in the structures of the porcine hypothalamic-pituitary-gonadal axis, as well as in the uterus, trophoblasts and conceptuses of pigs. In this study, we performed high-throughput proteomic analyses (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the influence of CHEM (400 ng/mL) on differentially regulated proteins (DRPs) in the porcine endometrial tissue explants during implantation (15 to 16 days of gestation). Among all 352 DRPs, 164 were up-regulated and 188 were down-regulated in CHEM-treated group. DRPs were assigned to 47 gene ontology (GO) terms (p-adjusted < 0.05). Validation of four DRPs (IFIT5, TGFβ1, ACO1 and PGRMC1) by Western blot analysis confirmed the veracity and accuracy of the LC-MS/MS method used in the present study. We suggest that CHEM, by modulating various protein expressions, takes part in the endometrial cell proliferation, migration and invasion at the time of implantation. It also regulates the endometrial immune response, sensitivity to P4 and the formation of new blood vessels. Additionally, CHEM appears to be an important factor involved in endothelial cell dysfunction during the pathogenesis of preeclampsia. The identification of a large number of DRPs under the influence of CHEM provides a valuable resource for understanding the molecular mechanisms of this hormone action during implantation, which is a prerequisite for better control of pig reproduction.

Effect of Human Peripheral Blood Mononuclear Cells on Mouse Endometrial Cell Proliferation: A Potential Therapeutics for Endometrial Regeneration

Objectives: The persistently thin endometrium is a major cause of repeated implantation failure; however, there is no definite treatment for it yet. This study aimed to confirm the potential of human peripheral blood mononuclear cells (hPBMCs) as a therapeutic agent for endometrial regeneration. Design: An experimental study was carried out. Participants/Materials, Setting, Methods: To assess the in vitro effect of hPBMC, the human primary endometrial epithelial cell lines SNU-685 and SNU-1077 were co-cultured with or without 1 × 105 hPBMCs for 24 h. To evaluate the in vivo effect, either 1 × 105 hPBMCs in PBS or PBS alone were injected into the left uterine horn of nonobese diabetic-severe combined immune-deficient mice, and the right untreated uterine horn was used as control. Results: Co-culture with hPBMCs stimulated significant proliferation in both SNU-685 and SNU-1077 cell lines (p = 0.002 and 0.044, respectively). Moreover, treatment with hPBMCs significantly increased the thickness in all parts of the endometrium compared with that in the untreated control uterine horn (proximal: 1.69 ± 0.19 vs. 1.00 ± 0.10, p = 0.009; middle: 1.51 ± 0.14 vs. 1.00 ± 0.12, p = 0.010; distal: 1.72 ± 0.22 vs. 1.00 ± 0.12, p = 0.003, respectively). Compared with the PBS injection group, the hPBMC injection group had significantly thickened endometrium in the middle (p = 0.036) and distal segments (p = 0.002) of the uterine horn. Immunohistochemical analysis revealed the presence of exogenously injected hPBMCs in the uterus of recipient mice. hPBMC-recipient mice had cyclic uterus with normal histology in the endometrium. Limitations: hPBMCs were not applied directly to a mouse model with thin endometrium, so further study is needed. Conclusion: The beneficial effect of hPBMCs on endometrium may suggest their clinical feasibility for the safe treatment of infertile patients with persistently thin endometrium.

The Role of mTOR and eIF Signaling in Benign Endometrial Diseases.

Adenomyosis, endometriosis, endometritis, and typical endometrial hyperplasia are common non-cancerous diseases of the endometrium that afflict many women with life-impacting consequences. The mammalian target of the rapamycin (mTOR) pathway interacts with estrogen signaling and is known to be dysregulated in endometrial cancer. Based on this knowledge, we attempt to investigate the role of mTOR signaling in benign endometrial diseases while focusing on how the interplay between mTOR and eukaryotic translation initiation factors (eIFs) affects their development. In fact, mTOR overactivity is apparent in adenomyosis, endometriosis, and typical endometrial hyperplasia, where it promotes endometrial cell proliferation and invasiveness. Recent data show aberrant expression of various components of the mTOR pathway in both eutopic and ectopic endometrium of patients with adenomyosis or endometriosis and in hyperplastic endometrium as well. Moreover, studies on endometritis show that derangement of mTOR signaling is linked to the establishment of endometrial dysfunction caused by chronic inflammation. This review shows that inhibition of the mTOR pathway has a promising therapeutic effect in benign endometrial conditions, concluding that mTOR signaling dysregulation plays a critical part in their pathogenesis.

Hypoxic induction of apoptosis occurs through HIF-1α and accompanies mammalian sterile 20-like kinase 2 cleavage in human endometrial adenocarcinoma Ishikawa cells

The incidence of endometrial cancer is increasing worldwide. One of the main causes of this cancer is a hormone imbalance; progesterone derivatives have been used for treatment. However, reports have shown that hypoxia plays important and possibly beneficial roles in endometrial function. Here, we show the effect of hypoxia on the proliferation of human endometrial adenocarcinoma Ishikawa cells. Hypoxia induced caspase-dependent apoptosis in Ishikawa cells. Overexpression and siRNA-mediated knockdown of hypoxia-inducible factor-1α (HIF-1α) confirmed that HIF-1α accelerates hypoxia-induced cell death. Treatment with dimethyloxalglycine, which stabilizes HIF-1α, suppressed cell proliferation. Kaplan–Meier analysis showed that the expression level of HIF-1α has a significant positive effect on the survival rate of endometrial cancer patients. In our search for cellular targets involved in hypoxic apoptosis, we noticed that mammalian sterile 20-like kinase 2 (MST2), a member of the Hippo pathway, was positively correlated with HIF-1α expression in 176 endometrial cancer patients extracted from the TCGA database. Hypoxia induced caspase-dependent MST2 cleavage. In addition, a MST2 inhibitor suppressed HIF-1α-mediated reporter activity. These results suggest HIF-1α and the Hippo signaling pathway are involved in endometrial cancer.

Heat Stress Impairs Maternal Endometrial Integrity and Results in Embryo Implantation Failure by Regulating Transport-Related Gene Expression in Tongcheng Pigs.

Heat stress (HS) poses a significant threat to production and survival in the global swine industry. However, the molecular regulatory effects of heat stress on maternal endometrial cells are poorly understood in pigs during early embryo implantation. In this study, we systematically examined morphological changes in the endometrium and the corresponding regulation mechanism in response to HS by combining scanning electron microscopy (SEM), hematoxylin/eosin (H&E) staining, western blot, and RNA-seq analyses. Our results showed that HS led to porcine endometrium damage and endometrial thinness during embryo implantation. The expression levels of cell adhesion-related proteins, including N-cadherin and E-cadherin, in the uterus were significantly lower in the heat stress group (39 ± 1 °C, n = 3) than in the control group (28 ± 1 °C, n = 3). A total of 338 up-regulated genes and 378 down-regulated genes were identified in porcine endometrium under HS. The down-regulated genes were found to be mainly enriched in the pathways related to the microtubule complex, immune system process, and metalloendopeptidase activity, whereas the up-regulated genes were mainly involved in calcium ion binding, the extracellular region, and molecular function regulation. S100A9 was found to be one of the most significant differentially expressed genes (DEGs) in the endometrium under HS, and this gene could promote proliferation of endometrial cells and inhibit their apoptosis. Meanwhile, HS caused endometrial epithelial cell (EEC) damage and inhibited its proliferation. Overall, our results demonstrated that HS induced uterine morphological change and tissue damage by regulating the expression of genes associated with calcium ions and amino acid transport. These findings may provide novel molecular insights into endometrial damage under HS during embryo implantation.

ATI-2341 Trifluoroacetic Acid (TFA) Promotes Menstrual Blood-Derived Mesenchymal Stem Cell Recruitment and Enhances Uterine Repair Through Gi Pathway in Asherman’s Syndrome

This study aimed to explore the role of ATI-2341 in Asherman’s syndrome and its impact on menstrual blood-derived mesenchymal stem cells (MenSCs). Following establishment of endometrial injury model, MenSCs were extracted from rats and cultured. They were treated with ATI-2341 TFA at different concentrations (10 ng/mL, 50 ng/mL, 100 ng/mL) and MenSCs treated without ATI-2341 TFA were taken as controls. Flow cytometry was conducted to detect the cell cycle. MTT was carried out to evaluate proliferation of endometrial cells. The expression levels of MMP-9, TIMP-1, CK, and VIM were determined with staining used to reflect morphology of endometrium. Administration with ATI-2341 TFA resulted in decreased expression of MMP-9 and increased expression of TIMP-1 in a dose-dependent manner. Of note, the increase of ATI-2341 TFA concentration was accompanied with elevated cell proliferation rate, increased number of glands in the endometrium, and decreased fibrosis area. As treated with 100 ng/mL ATI-2341 TFA, the cells exhibited more glands than that under other concentrations with uniformly arranged glands and lowest expression levels of CK and VIM, control group had plenty of blue-stained collagen fibers in the intima and least amount of glands. ATI-2341 TFA 100 ng/mL induced endometrial epithelial recruitment effect on MenSCs and promoted endometrial repair more significantly than Gi-3 pathway agonists. Collectively, ATI-2341 TFA enhances MenSC recruitment and facilitates endometrial epithelial cells proliferation and the repair of uterine damage in Asherman’s syndrome through Gi pathway. These findings provide a\ novel insight into the MenSC-based treatment against Asherman’s syndrome and deserve further investigation.

Long Intergenic Non-Protein Coding RNA 02381 Promotes the Proliferation and Invasion of Ovarian Endometrial Stromal Cells through the miR-27b-3p/CTNNB1 Axis.

Purpose: Catenin Beta 1 (CTNNB1) is a key regulator of cell proliferation and invasion in endometriosis; however, its upstream factor is not clear. Long noncoding RNAs may participate in endometriosis. The aim of this study was to investigate the mechanism of interaction between LINC02381 and CTNNB1 in endometriosis. Method: Screening and validation of RNAs were completed by whole transcriptional sequencing and qRT-PCR. The subcellular localization of LINC02381 was determined by RNA in situ hybridization and nucleo-cytoplasmic separation. Plasmids were transfected for functional experiments. Luciferase assay was used to verify the binding relationship. Results: The expression of LINC02381 and CTNNB1 was significantly increased in ovarian ectopic endometrial tissues (OSAs) and ectopic endometrial stromal cells (ESCs). When LINC02381 was downregulated in ESCs, the expression of CTNNB1, metallopeptidase 9 (MMP9) and cyclinD1, as well as ESCs invasion and proliferation, decreased. LINC02381 was mainly present in the cytoplasm of ESCs, indicating that it may act as a competitive endogenous RNA. Bioinformatic analysis revealed that microRNA-27b-3p (miR-27b-3p) is a downstream target of LINC02381. miR-27b-3p decreased in OSAs and ESCs. Moreover, when miR-27b-3p was upregulated in ESCs, the expression of CTNNB1, MMP9 and cyclinD1, as well as the invasion and proliferation ability of ESCs, were reduced. Additionally, rescue experiments demonstrated that the expression of CTNNB1, MMP9 and cyclinD1, as well as the invasion and proliferation ability, were significantly increased in the group transfected with both sh-LINC02381 and a miR-27b-3p inhibitor. Conclusion: LINC02381 upregulated CTNNB1 by adsorbing miR-27b-3p, causing increased proliferation and invasion of ESCs.

Effect of miR1290 on the growth of endometrial cancer and the related mechanism

Objective: To explore the expression of miR1290 in endometrial cancer tissues and its relationship with the pathological grade, and to find out the effect of miR1290 on biological characteristics of endometrial cancer cells and its mechanism. Methods: A total of 38 cases of endometrioid adenocarcinoma tissues, 10 cases of adjacent tissues and 23 cases of normal endometrial tissues were collected in Provincial Hospital Affiliated to Shandong University from May 2020 to October 2020. The expression of miR1290 was detected by reverse transcription polymerase chain reaction (RT-PCR). The expressions of miR1290 in endometrial cancer cells including KLE and Ishikawa were knocked down by lentiviral transfection. Cell counting kit 8 (CCK-8) test and colony formation test were used to detect cell proliferation ability, wound healing and Transwell test were used to detect cell invasion and migration ability, western blot was used to detect the expressions of epithelial-mesenchymal transition (EMT), phospholipids acylinositide 3-kinase (PI3K)/Akt and Wnt/β-catenin pathway related proteins. Results: The relative expressions of miR1290 in endometrial cancer tissues were 5.40±3.20, which was 1.55 times of normal endometrial tissues (P<0.01) and 1.75 times of adjacent tissues (P<0.01). The relative expressions of miR1290 in 17 cases of endometrial tissues at proliferative stage and 6 cases of endometrial tissues at secretory stage were 3.00±1.08 and 4.97±0.58, respectively, and the difference was statistically significant (P<0.01). In KLE cells and Ishikawa cells, the expression of miR1290 in miR1290 knockdown (Sh-miR1290) group was decreased when compared with the negative control (Sh-NC) group. The absorbance value of Sh-miR1290 group detected by the CCK-8 method and the colony formation rate detected by the colony formation experiment were both increased, the number of cells penetrating the basement membrane in the Transwell experiment and the wound healing rate in the scratch experiment were decreased (P<0.05). In KLE cells, knockdown of miR1290 reduced the expressions of EMT-related proteins including N-cadherin, Vimentin, Snail and Slug(P<0.05), and the expressions of PI3K and P-Akt/Akt (P<0.05), while there was no significant change in the expressions of Wnt and β-catenin (P>0.05). In Ishikawa cells, knockdown of miR1290 decreased the expressions of EMT-related proteins including N-cadherin, Snail and Slug, and the expressions of Wnt and β-catenin, increased the expression of E-cadherin (P<0.05), while there was no significant change in the expressions of PI3K and P-Akt/Akt (P>0.05). Conclusions: The expressions of miR1290 in endometrial cancer tissues are higher than that in the adjacent tissues and normal endometrial tissues. Knockdown of miR1290 expression can promote the proliferation of endometrial cancer cells, but inhibit cell invasion, migration and EMT ability through the PI3K/Akt and Wnt/β-catenin pathways.

Identification of miR-34-3p as a candidate follicular phase serum marker for endometriosis: a pilot study

To identify early follicular phase microribonucleic acids (miRNAs) that are altered in serum of women with endometriosis. Case-control study. Large university-affiliated invitro fertilization center. Women with (n = 21) and without (n = 24) endometriosis. Serum samples were obtained from laparoscopy-confirmed patients with endometriosis. The differential expression of serum miRNAs relative to controls was measured using the NanoString nCounter technology and validated by quantitative real-time polymerase chain reaction in an independent cohort of 27 patients with endometriosis and controls (n = 24). Microribonucleic acid target signaling pathways and genes were analyzed bioinformatically. A chemically modified stable miR-34-3p oligonucleotide was used to examine the effect on proliferation of VK2E6/E7 endometrial cells invitro. Eighteen miRNAs were significantly up-regulated, and 1 miRNA (hsa-miR-34c-3p) was significantly down-regulated in the follicular phase of patients with endometriosis. The analysis of target signaling pathways using TargetScan predicted regulation of the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B, Hippo, adenosine monophosphate-activated protein kinase, transforming growth factor beta, and endometrial cancer pathways, which have been implicated in the pathogenesis of endometriosis, by these miRNAs. The analysis of sequence complementarity identified prostaglandin E2 receptor 4, interleukin 6 signal transducer, and polo-like kinase 4 genes as possible direct targets of hsa-miR-34-3p. DSDI-1, a chemically modified stable miR-34-3p oligonucleotide, reduced cell proliferation in VK2E6/E7 endometrial cells invitro. The follicular phase miRNA levels are altered in serum of women with endometriosis and may be useful as reproducible detection biomarkers for early diagnosis of endometriosis. hsa-miR-34-3p is significantly down-regulated in endometriosis, targets endometriosis genes, and reduces endometrial cell proliferation invitro. These results support hsa-miR-34-3p as a potential therapeutic target in endometriosis.

WNT5A Interacts With FZD5 and LRP5 to Regulate Proliferation and Self-Renewal of Endometrial Mesenchymal Stem-Like Cells.

Endometrial mesenchymal stem-like cells (eMSC) reside in the basal layer of the endometrium and are responsible for cyclic regeneration during the reproductive lives of women. Myometrial cells act as a component of the niche and regulate the stem cell fate through the activation of WNT/β-catenin signaling via WNT5A. Since WNT5A-responsive mechanisms on eMSC are still uncertain, we hypothesize that the WNT ligand–WNT5A works to activate WNT/β-catenin signaling through binding to Frizzled receptors (FZDs) and co-receptor low-density lipoprotein receptor-related protein 5 (LRP5). Among the various receptors that have been reported to interact with WNT5A, we found FZD5 abundantly expressed by eMSC when compared to unfractionated stromal cells. Neutralizing the protein expression by using anti-FZD5 antibody suppressed the stimulatory effects on phenotypic expression and the clonogenicity of eMSC in a myometrial cell–eMSC co-culture system as well as in an L-Wnt5a conditioned medium. Gene silencing of FZD5 not only reduced the binding of WNT5A to eMSC but also decreased the TCF/LEF transcriptional activities and expression of active β-catenin. Inhibition of LRP coreceptors with recombinant Dickkopf-1 protein significantly reduced the binding affinity of eMSC to WNT5A as well as the proliferation and self-renewal activity. During postpartum remodeling in mouse endometrium, active β-catenin (ABC) was detected in label-retaining stromal cells (LRSCs), and these ABC+ LRSCs express FZD5 and LRP5, suggesting the activation of WNT/β-catenin signaling. In conclusion, our findings demonstrate the interaction of WNT5A, FZD5, and LRP5 in regulating the proliferation and self-renewal of eMSC through WNT/β-catenin signaling.

CHCHD2 Regulates Mitochondrial Function and Apoptosis of Ectopic Endometrial Stromal Cells in the Pathogenesis of Endometriosis.

Endometriosis is a disease that involves dysfunction of mitochondria, imbalance of proliferation, and apoptosis. Coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2) is a major mitochondrial protein which could regulate the mitochondrial function and apoptosis in various tumor cells, promote migration and then lead to tumor progression. This study aimed to explore the role of CHCHD2 on endometriosis. We investigated the expression of CHCHD2 in ectopic and eutopic endometrium tissues of patients with endometriosis and normal endometrium tissues. Furthermore, CHCHD2 was downregulated to explore the corresponding change of mitochondrial function and morphology, mitochondrial-mediated apoptosis pathway, and proliferation and migration of ectopic endometrial stromal cells. Our results demonstrated that the mRNA and protein expression levels of CHCHD2 were significantly increased in eutopic and ectopic endometrium tissues compared with the normal endometrium tissues. The knockdown of CHCHD2 could cause mitochondrial dysfunction, including the opening of mitochondrial permeability transition pore, loss of mitochondrial membrane potential and the release of cytochrome c, and morphological damage. In addition, CHCHD2 down-expression could also lead to inhibition of cell proliferation, decrease of migration ability, and aggravation of mitochondrial-mediated apoptosis. Together, these findings suggest that increased expression of CHCHD2 in endometriotic tissues may contribute to the pathogenesis of endometriosis via regulating mitochondrial function and apoptosis, and CHCHD2 may be a potential target for interrupting the development of endometriosis.

MAX deficiency impairs human endometrial decidualization through down-regulating OSR2 in women with recurrent spontaneous abortion

Human uterine stromal cell undergoes decidualization for pregnancy establishment and maintenance, which involved extensive proliferation and differentiation. Increasing studies have suggested that recurrent spontaneous abortion (RSA) may result from defective endometrial stromal decidualization. However, the critical molecular mechanisms underlying impaired decidualization during RSA are still elusive. By using our recently published single-cell RNA sequencing (scRNA-seq) atlas, we found that MYC-associated factor X (MAX) was significantly downregulated in the stromal cells derived from decidual tissues of women with RSA, followed by verification with immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR). MAX knockdown significantly impairs human endometrial stromal cells (HESCs) proliferation as determined by MTS assay and Ki67 immunostaining, and decidualization determined by F-actin, and decidualization markers. RNA-seq together with chromatin immunoprecipitation sequencing (ChIP-seq) and cleavage under targets and release using nuclease sequencing (CUT&RUN-seq) analysis were applied to explore the molecular mechanisms of MAX in regulation of decidualization, followed by dual-luciferase reporter assay to verify that MAX targets to (odd-skipped related transcription factor 2) OSR2 directly. Reduced expression of OSR2 was also confirmed in decidual tissues in women with RSA by IHC and qRT-PCR. OSR2 knockdown also significantly impairs HESCs decidualization. OSR2-overexpression could at least partly rescue the downregulated insulin-like growth factor binding protein 1 (IGFBP1) expression level in response to MAX knockdown. Collectively, MAX deficiency observed in RSA stromal cells not only attenuates HESCs proliferation but also impairs HESCs decidualization by downregulating OSR2 expression at transcriptional level directly.

Synergistic regenerative therapy of thin endometrium by human placenta-derived mesenchymal stem cells encapsulated within hyaluronic acid hydrogels

BackgroundThin endometrium is a primary cause of defective endometrial receptivity, resulting in infertility or recurrent miscarriage. Much effort has been devoted toward regenerating thin endometrium by stem cell-based therapies. The human placenta-derived mesenchymal stem cells (HP-MSCs) are emerging alternative sources of MSCs with various advantages. To maximize their retention inside the uterus, we loaded HP-MSCs with cross-linked hyaluronic acid hydrogel (HA hydrogel) to investigate their therapeutic efficacy and possible underlying mechanisms.MethodsEthanol was injected into the mice uterus to establish the endometrium-injured model. The retention time of HP-MSCs and HA hydrogel was detected by in vivo imaging, while the distribution of HP-MSCs was detected by immunofluorescence staining. Functional restoration of the uterus was assessed by testing embryo implantation rates. The endometrial morphological alteration was observed by H&E staining, Masson staining, and immunohistochemistry. In vitro studies were further conducted using EdU, transwell, tube formation, and western blot assays.ResultsInstilled HP-MSCs with HA hydrogel (HP-MSCs-HA) exhibited a prolonged retention time in mouse uteri than normal HP-MSCs. In vivo studies showed that the HP-MSCs-HA could significantly increase the gland number and endometrial thickness (P < 0.001, P < 0.05), decrease fibrous area (P < 0.0001), and promote the proliferation and angiogenesis of endometrial cells (as indicated by Ki67 and VEGF, P < 0.05, P < 0.05, respectively) in mice injured endometrium. HP-MSCs-HA could also significantly improve the embryo implantation rate (P < 0.01) compared with the ethanol group. Further mechanistic study showed the paracrine effects of HP-MSCs. They could not only promote the proliferation and migration of human endometrial stromal cells via the JNK/Erk1/2-Stat3-VEGF pathway but also facilitate the proliferation of glandular cells via Jak2-Stat5 and c-Fos-VEGF pathway. In turn, the increased VEGF in the endometrium promoted the angiogenesis of endothelial cells.ConclusionOur study suggested the potential therapeutic effects and the underlying mechanisms of HP-MSCs-HA on treating thin endometrium. HA hydrogel could be a preferable delivery method for HP-MSCs, and the strategy represents a promising therapeutic approach against endometrial injury in clinical settings.Graphical abstract

Down-regulation of PBK inhibits proliferation of human endometrial stromal cells in thin endometrium

BackgroundThin endometrium (TE) is a challenging clinical issue in the reproductive medicine characterized by inadequate endometrial thickness, poor response to estrogen and no effective treatments currently. At present, the precise pathogenesis of thin endometria remains to be elucidated. We aimed to explore the related molecular mechanism of TE by comparing the transcriptome profiles of late-proliferative phase endometria between TE and matched controls.MethodsWe performed a bulk RNA-Seq (RNA-sequencing) of endometrial tissues in the late-proliferative phase in 7 TE and 7 matched controls for the first time. Differential gene expression analysis, gene ontology enrichment analysis and protein-protein interactions (PPIs) network analysis were performed. Immunohistochemistry was used for molecular expression and localization in endometria. Human endometrial stromal cells (HESCs) were isolated and cultured for verifying the functions of hub gene.ResultsIntegrative data mining of our RNA-seq data in endometria revealed that most genes related to cell division and cell cycle were significantly inhibited, while inflammation activation, immune response and reactive oxygen species associated genes were upregulated in TE. PBK was identified as a hub of PPIs network, and its expression level was decreased by 2.43-fold in endometria of TE patients, particularly reduced in the stromal cells, which was paralleled by the decreased expression of Ki67. In vitro experiments showed that the depletion of PBK reduced the proliferation of HESCs by 50% and increased the apoptosis of HESCs by 1 time, meanwhile PBK expression was inhibited by oxidative stress (reduced by 76.2%), hypoxia (reduced by 51.9%) and inflammatory factors (reduced by approximately 50%). These results suggested that the insufficient expression of PBK was involved in the poor endometrial thickness in TE.ConclusionsThe endometrial transcriptome in late-proliferative phase showed suppressed cell proliferation in women with thin endometria and decreased expression of PBK in human endometrial stromal cells (HESCs), to which inflammation and reactive oxygen species contributed.

Circ_0002577/miR-126-5p/MACC1 axis promotes endometrial carcinoma progression by regulation of proliferation, migration, invasion, and apoptosis of endometrial carcinoma cells.

Endometrial carcinoma (EC) is a common female reproductive malignant tumor. Circular RNAs (circRNAs) have been reported to participate in tumorigenesis, including EC. Therefore, this study was designed to clarify the role and underlying molecular mechanisms of circ_0002577 in EC. The expression levels of circ_0002577, miR-126-5p, and metastasis associated in colon cancer 1 (MACC1) was determined by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The protein expression was quantified by western blot assay. The proliferation of EC cells was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and colony-forming assays. The migration and invasion of EC cells was measured by transwell assay. The apoptosis was determined by flow cytometry assay. Dual-luciferase reporter assay and RNA pull-down assays were performed to confirm the relationship between miR-126-5p and circ_0002577 or MACC1. The influence of circ_0002577 inhibition on tumor growth was assessed by xenograft experiment. Circ_0002577 and MACC1 were increased while miR-126-5p was decreased in EC tissues and cells. Loss-of-functional experiment revealed that silencing of circ_0002577 inhibited the proliferation, migration, and invasion while induced apoptosis of EC cells, which were overturned by overexpression of MACC1. The upregulation of miR-126-5p also impeded proliferation and mobility while induced apoptosis of EC cells. MiR-126-5p, negatively regulating MACC1 expression, was a functional target of circ_0002577 in EC cells. Moreover, we also confirmed that suppression of circ_0002577 repressed tumor growth in vivo. The contributions of the circ_0002577 in EC were contributed to its interactions with miR-126-5p and MACC1, which offered a new perspective to the roles of circ_0002577 in EC.

Hsa_circ_0039569 facilitates the progression of endometrial carcinoma by targeting the miR-197/high mobility group protein A1 axis

ABSTRACT Circular RNAs are novel regulators in endometrial carcinoma. Hsa_circ_0039569 was reportedly upregulated in endometrial carcinoma; however, the functional roles and mechanisms of hsa_circ_0039569 need further investigation. Therefore, we used quantitative real-time PCR (qRT–PCR) to determine the mRNA levels of hsa_circ_0039569, miR-197 and high mobility group protein A1 (HMGA1). The protein level of HMGA1 was determined by Western blot. Cell Counting Kit-8 and colony formation assays were used to assess cell proliferation. Cell migration was measured via wound healing and Transwell assays. Transwell assay was also performed to determine cell invasion ability. Direct binding of the indicated molecules were verified by RNA binding protein immunoprecipitation (RIP) assay and dual luciferase reporter assay. The results revealed that hsa_circ_0039569 and HMGA1 were elevated, while miR-197 was downregulated in endometrial carcinoma. Moreover, hsa_circ_0039569 was positively correlated with the expression of HMGA1 and was negatively correlated with the level of miR-197. In addition, hsa_circ_0039569 facilitated the proliferation, migration and invasion of endometrial carcinoma cells. The underlying mechanism is that hsa_circ_0039569 serves as a sponge of miR-197 to repress the inhibitory effect of miR-197 on HMGA1. Furthermore, the miR-197/HMGA1 axis was implicated in endometrial carcinoma progression accelerated by hsa_circ_0039569. Collectively, hsa_circ_0039569 may promote the development of endometrial carcinoma by serving as an endogenous sponge of miR-197, increasing HMGA1 expression and identifying a novel target for endometrial carcinoma treatment.

Rhotekin 2 promotes progression of endometrial carcinoma by activating Akt/GSK3β signaling pathway

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To investigate the expression of rhotekin 2 (RTKN2) in human endometrial carcinoma tissues and its role in cancer progression.&#x0D; Methods: Quantitative polymerase chain reaction (qPCR) and immunoblot assays were performed to determine the expression of RTKN2 in endometrial carcinoma tissues and cells. The effects of RTKN2 on cell proliferation were assessed using cell counting kit-8 and EdU assays, while its effects on cell cycle and apoptosis in endometrial carcinoma cells were evaluated by flow cytometry. The involvement of RTKN2 in activating Akt/glycogen synthase kinase-3 beta (GSK3β) pathway was characterized using an immunoblot assay. Tumor growth assays were performed to assess the effects of RTKN2 on the progression of endometrial carcinoma in vivo, while protein expression in tumor tissues was determined by an immunohistochemical assay.&#x0D; Results: High expression of RTKN2 was found in human endometrial carcinoma tissues and cell lines (p &lt; 0.05). RTKN2 promoted the proliferation and cell cycle of endometrial carcinoma cells in vitro and suppressed apoptosis (p &lt; 0.05). RTKN2 also activated Akt/GSK3β pathway in endometrial carcinoma cells and thus promoted tumor growth in vivo.&#x0D; Conclusion: The involvement of RTKN2 in the progression of endometrial carcinoma has been confirmed in this study. RTKN2 is thus a promising therapeutic target for patients with this disease.&#x0D; &#x0D; &#x0D; &#x0D;