circRNA3669 promotes goat endometrial epithelial cells proliferation via miR-26a/RCN2 to activate PI3K/AKT-mTOR and MAPK pathways

The development of receptive endometrium(RE) from pre-receptive endometrium(PE) for successful embryo implantation is a complex dynamic process in which the morphology and physiological states of the endometrial epithelium undergo a series of significant changes, including cell proliferation and apoptosis. However, the molecular mechanisms are not yet fully understood. In this study, a higher circRNA3669 level was observed in PE than in RE of goats. Functional assays revealed that this overexpression promoted the proliferation of goat endometrial epithelial cells(GEECs) by activating the expression of genes related to the PI3K/AKT-mTOR and MAPK pathways,thereby inhibiting apoptosis in vitro. Furthermore, circRNA3669 functioned as a competing endogenous RNA(ceRNA) to upregulate Reticulocalbin-2(RCN2) expression at the post-transcriptional level by interacting with and downregulating miR-26a in GEECs. In addition, RCN2, which is highly expressed in the PE of goats, was found to be regulated by β-estradiol(E2) and progesterone(P4). Our results demonstrated that RCN2 also affected the key proteins PI3K, AKT, mTOR, JNK, and P38 in the PI3K/AKT-mTOR and MAPK pathways, thereby facilitating GEECs proliferation and suppressing their apoptosis in vitro. Collectively, we constructed a new circRNA3669-miR-26aRCN2 regulatory network in GEECs, which further provides strong evidence that circRNA could potentially play a crucial regulatory role in the development of RE in goats.

Punicalagin protects bovine endometrial epithelial cells against lipopolysaccharide-induced inflammatory injury

Objective：Bovine endometritis is one of the most common reproductive disorders in cattle.The aim of this study was to investigate the anti-inflammation potential of punicalagin in lipopolysaccharide（LPS）-induced bovine endometrial epithelial cells（bE ECs）and to uncover the underlying mechanisms.Methods：bE ECs were stimulated with different concentrations（1,10,30,50,and 100μg/ml）of LPS for 3,6,9,12,and 18 h.MTT assay was used to assess cell viability and to identify the conditions for inflammatory injury and effective concentrations of punicalagin.Quantitative real-time polymerase chain reaction（q RT-PCR）was used to assess gene expression of pro-inflammatory cytokines.Western blotting was used to assess levels of inflammation-related proteins.Results：Treatment of b EECs with 30μg/ml LPS for 12 h induced cell injury and reduced cell viability.Punicalagin（5,10,or 20μg/ml）pretreatment significantly decreased LPS-induced productions of interleukin（IL）-1β,IL-6,IL-8,and tumor necrosis factor-α（TNF-α）in bE ECs.Molecular research showed that punicalagin inhibited the activation of the upstream mediator nuclear factor-κB（NF-κB）by suppressing the production of inhibitorκBα（IκBα）and phosphorylation of p65.Results also indicated that punicalagin can suppress the phosphorylation of mitogen-activated protein kinases（MAPKs）including p38,c-Jun N-terminal kinase（JNK）,and extracellular signal-regulated kinase（ERK）.Conclusions：Punicalagin may attenuate LPS-induced inflammatory injury and provide a potential option for the treatment of dairy cows with Escherichia coli endometritis.

Adenomyosis-derived extracellular vesicles endow endometrial epithelial cells with an invasive phenotype through epithelial-mesenchymal transition

Extracellular vesicles from highly metastatic tumor cells have been shown to mediate epithelial-mesenchymal transition(EMT)-related events in recipient cells.In endometrial epithelial cells,EMT processes are known to be involved in the development of adenomyosis.We aimed to investigate whether adenomyosis-derived extracellular vesicles(AMEVs)are able to induce an EMT process in endometrial epithelial cells.In this study,AMEVs were isolated from patients with adenomyosis and characterized by transmission electron microscopy,Western blot,and nanoparticle tracking.Primary endometrial epithelial cells(EECs)were derived from normal endometrium tissues from patients with leiomyoma and co-cultured with AMEVs in vitro.AMEV uptake was examined by fluorescence confocal microscopy.The invasion of EECs was confirmed by Transwell assay.Immunohistochemistry,Western blot,and qRT-PCR were performed on EECs to illustrate the expression levels of cytokeratin 19,E-cadherin,vimentin,and zinc finger E-boxbinding homeobox 1(ZEB1).The results indicated that the cellular fluorescence intensity gradually increased after 48 h of co-culture,but decreased after 72 h.After co-culturing with AMEVs for 72 h,EECs expressed significantly lower levels of cytokeratin 19 and E-cadherin,and significantly higher levels of vimentin and ZEB1.Together these results demonstrated that AMEVs induce an EMT process and enhance the invasion of EECs.These changes may contribute to the pathogenesis and progression of adenomyosis.

Differentiation of Human Adipose-Derived Stem Cells into Endometrial Epithelial Cells

Objective:This study aimed to investigate the differentiation of human adipose-derived stem cells(hASCs)into endometrial epithelial cells(EECs)under certain induction conditions and to a further step provide a promising approach for ASCs in clinical practice to the treatment of severe intrauterine adhesion.Methods:Four groups of hASCs were separately cultured as follows:in Group 1,hASCs were cultured in a control medium(5%fetal bovine serum[FBS]+α-minimum Eagle’s medium[α-MEM]);in Group 2,hASCs were cultured in an induction medium(5%FBS+α-MEM+[1×10-7 mol/L 17β-estradiol]+10 ng/mL transforming growth factorβ1[TGF-β1]+10 ng/mL epidermal growth factor[EGF]+10 ng/mL platelet-derived growth factor BB[PDGF-BB]);in Group 3,hASCs and human endometrium cells(hEMCs)were cocultured in the control medium;and in Group 4,hASCs and hEMCs were cocultured in the induction medium.Results:When cocultured with hEMCs,the morphology of hASCs became similar with EECs,and the addition of factors such as EGF,TGFβ,PDGF-BB,and 17β-estradiol promoted differentiation.This study,for the first time,demonstrated estrogen receptor(ER)αand ERβexpression in hASCs and preliminarily explored changes in ERα,ERβ,β-catenin,and H19 mRNA expression during hASC differentiation.Furthermore,we concluded that H19 mRNA expression was negatively correlated with differentiation,which is seemingly related to the estrogen signaling pathway.Conclusions:hASCs revealed the potential for differentiating to EECs when cocultured with hEMCs.

Isolation, Cuture and Biological Characteristic Analysis of Stromal and Glandular Epithelial Cells of Buffalo (Bubalus bubalis) Endometrium

[Objective] The experiment aimed to set up a method for isolating and culturing endometrial stromal cells (BESC) and endometrial glandular epithelial cells(BEGEC) of buffalo as well as laid foundation for studying biological mechanism of embryo implantation and uterine diseases. [Method] The enzymatic digestion method, scraping method, serial filtration and differential velocity adherent technique were used to isolate BESC and BEGEC, then immunocytochemical method and TRYPAN-Blue assay were used to determine the purity and survival rate of isolated cells. [Result] The BESC and BEGEC were successfully isolated and cultured while immunocytochemical method and cell count method demonstrated that the purity was over 90%. The result of TRYPAN-Blue assay shown that survival rate of BESC and BEGEC was 91% and 78% respectively. [Conclusion] The enzymatic digestion method, scraping method, serial filtration and differential velocity adherent technique could isolate BESC and BEGEC with high purity.