Abnormal activation of the sonic hedgehog signaling pathway in endometriosis and its diagnostic potency

PDLIM3 knockdown promotes ferroptosis in endometriosis progression via inducing Gli1 degradation and blocking Hedgehog signaling pathway

AIMS

Current evidence suggests that there is no completely effective method for endometriosis (EMS) without trauma due to diverse adverse effects. Reliable evidence illustrates that inhibiting ferroptosis is a potential strategy for EMS. We sufficiently verified that the expression of endogenous protein PDZ and LIM domain 3 (PDLIM3) was significantly increased in EMS.

METHODS

PDLIM3 knockdown reduced primary ectopic endometrial stromal cells' (EESCs) viability and migration, and elevated ferroptosis signaling indicators including Fe2+, malondialdehyde (MDA), and reactive oxygen species (ROS) in EESCs.

RESULTS

Mechanistic studies revealed that inhibition of PDLIM3 accelerated glioma-associated oncogene-1 (Gli1) degradation and further deactivated Hedgehog signaling. Gli1 inhibitor, GANT61, abrogated the impact of PDLIM3 deletion on EESC growth, migration, and ferroptosis. In vivo experiments suggested that PDLIM3 reduction repressed the growth of endometrial lesions. Likewise, repression of PDLIM3 promoted ferroptosis and attenuated Hedgehog signaling in endometrial lesions.

CONCLUSIONS

Collectively, silencing of PDLIM3 facilitates ferroptosis in EMS by inducing Gli1 degradation and blocking Hedgehog signaling. It may provide an alternative strategy for developing therapeutic agents of EMS in the future.

METTL3-mediated m6A modification of SIRT1 mRNA inhibits progression of endometriosis by cellular senescence enhancing

BACKGROUND

Endometriosis (EMs), the ectopic planting of functional endometrium outside of the uterus, is a leading cause of infertility and pelvic pain. As a fundamental mRNA modification, N6-methyladenosine (m6A) participates in various pathological processes. However, the role of m6A RNA modification in endometriosis remains unclear. The present study explores METTL3-mediated m6A modification and the mechanisms involved in endometriosis.

METHODS

The dominant m6A regulators in EMs were analysed using RT‒PCR. Candidate targets and possible mechanisms of METTL3 were assessed by m6A-mRNA epitranscriptomic microarray and RNA sequencing. A primary ESCs model was employed to verify the effect of METTL3 on m6A modification of SIRT1 mRNA, and the mechanism was elucidated by RT‒PCR, Western blotting, MeRIP, and RIP assays. CCK-8 viability assays, Transwell invasion assays, EdU proliferation assays, wound healing migration assays, and senescence-associated β-galactosidase staining were performed to illuminate the potential biological mechanism of METTL3 and SIRT1 in ESCs in vitro. An in vivo PgrCre/ + METTL3 -/- female homozygous mouse model and a nude mouse xenograft model were employed to further investigate the physiologic consequences of METTL3-mediated m6A alteration on EMs.

RESULTS

Our data show that decreased METTL3 expression significantly downregulates m6A RNA methylation levels in ESCs. Silencing m6A modifications mediated by METTL3 accelerates ESCs viability, proliferation, migration, and invasion in vitro. The m6A reader protein YTHDF2 binds to m6A modifications to induce the degradation of SIRT1 mRNA. SIRT1/FOXO3a signalling pathway activation is subsequently inhibited, promoting the cellular senescence of ESCs and inhibiting the ectopic implantation of ESCs in vitro and in vivo.

CONCLUSIONS

Our findings demonstrate that METTL3-mediated m6A methylation epigenetically regulates the ectopic implantation of ESCs, resulting in the progression of endometriosis. Our study establishes METTL3-YTHDF2-SIRT1/FOXO3a as a critical axis and potential mechanism in endometriosis.

Research advances in endometriosis-related signaling pathways: A review

Endometriosis (EM) is characterized by the existence of endometrial mucosa outside the uterine cavity, which causesinfertility, persistent aches, and a decline in women's quality of life. Both hormone therapies and nonhormone therapies, such as NSAIDs, are ineffective, generic categories of EM drugs. Endometriosis is a benign gynecological condition, yet it shares a number of features with cancer cells, including immune evasion, survival, adhesion, invasion, and angiogenesis. Several endometriosis-related signaling pathways are comprehensively reviewed in this article, including E2, NF-κB, MAPK, ERK, PI3K/Akt/mTOR, YAP, Wnt/β-catenin, Rho/ROCK, TGF-β, VEGF, NO, iron, cytokines and chemokines. To find and develop novel medications for the treatment of EM, it is essential to implicitly determine the molecular pathways that are disordered during EM development. Additionally, research on the shared pathways between EM and tumors can provide hypotheses or suggestions for endometriosis therapeutic targets.

IHH, SHH, and primary cilia mediate epithelial-stromal cross-talk during decidualization in mice

The establishment of pregnancy depends on interactions between the epithelial and stromal cells of the endometrium that drive the decidual reaction that remodels the stroma and enables embryo implantation. Decidualization in mice also depends on ovarian hormones and the presence of a blastocyst. Hedgehog signaling is transduced by primary cilia in many tissues and is involved in epithelial-stromal cross-talk during decidualization. We found that primary cilia on mouse uterine stromal cells increased in number and length during early pregnancy and were required for decidualization. In vitro and in vivo, progesterone promoted stromal ciliogenesis and the production of Indian hedgehog (IHH) in the epithelium and Sonic hedgehog (SHH) in the stroma. Blastocyst-derived TNF-α also induced epithelial IHH, which stimulated the production of SHH in the stroma through a mechanism that may involve the release of arachidonic acid from epithelial cells. In the stroma, SHH activated canonical Hedgehog signaling through primary cilia and promoted decidualization through a mechanism that depended on interleukin-11 (IL-11) and primary cilia. Our findings identify a primary cilia-dependent network that controls endometrial decidualization and suggest primary cilia as a candidate therapeutic target for endometrial diseases.

Effects of an inhibitor of the SHH signaling pathway on endometrial cells of patients with endometriosis

Background

Endometriosis is one of the most common gynecological diseases, and seriously reduces the quality of life of patients. However, the pathogenesis of this disease is unclear. Therefore, more studies are needed to elucidate its pathogenesis. Our previous publication found that the Sonic Hedgehog (SHH) signaling pathway was activated in endometriosis. This study tested whether SHH signaling in endometrial stromal cells (ESCs) was critical for the pathogenesis of endometriosis.

Methods

To examine the effect of inhibiting the SHH signaling pathway on endometriosis, we first isolated ESCs from eutopic endometrial tissues of patients with or without endometriosis and identified the extracted cells by morphological observation and immunofluorescence. Then, we treated ESCs with the GLI inhibitor GANT61 and used CCK-8, wound healing and invasion assays to detect cell activities, such as proliferation, invasion and metastasis. Furthermore, we detected the expression of key proteins and proliferation markers of the SHH signaling pathway in the lesions of nude mice using immunochemistry.

Results

We demonstrated that higher concentrations of GANT61 decreased the proliferation rate and migration distance of ESCs. We observed that GANT61 inhibited the invasion of ESCs. In addition, blockage of the SHH signaling pathway significantly reduced cell proliferation in vitro.

Conclusions

Our study suggested that inhibition of the SHH pathway is involved in cell proliferation and invasive growth in the pathogenesis of endometriosis.

Anti-hepatoma effect of taccalonolide A through suppression of sonic hedgehog pathway

Taccalonolide A has been reported to have anti-tumour efficiency. However, the underlying mechanism for taccalonolides A therapy of hepatocellular carcinoma (HCC) is still obscure. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. Apoptosis was determined by flow cytometry. Protein expression of B cell lymphoma (Bcl-2), Bcl-2 associated X (Bax), sonic hedgehog (Shh), Smoothened (Smo) and Gli family zinc finger 1 (Gli1) was analyzed by western blot. The expression of Shh, Smo and Gli1 mRNA was determined using quantitative real-time polymerase chain reaction (qRT-PCR). Results showed that taccalonolide A inhibited cell proliferation, induced apoptosis and cell cycle arrest at the G0/G1 phase, and improved the cytotoxicity of sorafenib in HCC cells. The expressions of Shh, Smo, Gli1 mRNA and protein were decreased after taccalonolide A treatment. More importantly, activation of the Shh pathway attenuated taccalonolide A-induced inhibition on cell viability and promotion on apoptosis and cell cycle arrest in HCC. Also, activation of the Shh pathway neutralized the effect of taccalonolide A on sorafenib cytotoxicity in HCC. We clarified that taccalonolide A suppressed cell viability facilitated apoptosis, and improved the cytotoxicity of sorafenib in HCC by inhibition of the activation of the Shh pathway, providing alternative treatments for HCC.

The effects of hedgehog ligand neutralising antibody 5E1 in a mouse model of endometriosis

Objective

Endometriosis is a common and painful condition characterised by the formation of endometrial lesions within the peritoneal cavity. Previous studies have suggested a role for hedgehog signalling in the pathogenesis of endometriosis. We investigated the role of hedgehog signalling in the establishment of endometriosis lesions using 5E1, a hedgehog ligand neutralising antibody, and a mouse model of endometriosis. To mimic the initiation of endometriosis by retrograde menstruation, which is believed to occur in humans, donor mice underwent an artificial menstruation protocol. Fragments of menstrual endometrium were injected into the peritoneal cavity of estrogen primed recipients. Recipients received twice weekly injections of 5E1 or an isotype matched control antibody for three weeks. Lesions were collected and analysed for markers of epithelium, proliferation and apoptosis by immunofluorescence microscopy.

Results

Treatment with 5E1 reduced the number of lesions found on the mesentery. No significant changes were found in the size of lesions, abundance of endometrial epithelial cells, proliferation or apoptosis.

Analysis of exosomal lncRNA, miRNA and mRNA expression profiles and ceRNA network construction in endometriosis

Aim: To investigate exosomal RNAs (long noncoding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNAs (mRNAs)) profiling and their related networks in endometriosis (EMs). Materials & methods: RNA sequence was performed in exosomes from ovarian endometriomas (EC), eutopic endometria (EU) and normal endometria (Control) stromal cells. The bioinformatics algorithms evaluated competing endogenous RNA (ceRNA) networks. The top-ranked ceRNA networks were confirmed by RT-PCR. Results: Overlapped differentially expressed 938 lncRNAs, 39 miRNAs and 1449 mRNAs were identified. 13 co-expression modules and 61 ceRNA networks were constructed. Conclusion: This study for the first time shows exosomal RNA biomarkers and lncRNA-related networks in EMs, which reveals a novel molecular mechanism of EMs and provides new resources for EM diagnosis and treatment.

Dysregulation of miR-202-3p Affects Migration and Invasion of Endometrial Stromal Cells in Endometriosis via Targeting ROCK1

Dysregulation of microRNAs in endometrial cells plays a pivotal role in the pathogenesis of endometriosis (EM). This study aims to investigate the implication of aberrant miR-202-3p expression in EM and the underlying mechanisms. We demonstrated that miR-202-3p was significantly downregulated in eutopic endometrium of EM in comparison to normal endometrial samples (P < 0.05). Primary endometrial stromal cells (ESCs) isolated from eutopic or ectopic endometrium also showed a significant decrease in miR-202-3p level compared to ESCs from normal endometrium (P < 0.01). Functional studies using MTT, wound healing assay and transwell assay indicated that overexpression of miR-202-3p greatly impaired cell viability, migration, and invasion, whereas suppression of miR-202-3p exhibited the opposite effects (P < 0.05 or P < 0.01). miR-202-3p mimics or inhibitors transfection significantly decreased or increased expression of Rho-associated, coiled-coil containing protein kinase 1 (ROCK1), respectively, in ESCs (P < 0.01). Using dual luciferase reporter assay, we validated ROCK1 as a direct target of miR-202-3p. Moreover, negative correlations between miR-202-3p and ROCK1 mRNA/protein levels were determined in both eutopic and normal control endometrium (P < 0.01). In conclusion, these findings suggest that suppression of miR-202-3p in ESCs results in enhanced cell viability, invasion, and migration at least partially via upregulation of its target ROCK1, which eventually contributes to the development of endometriosis.

Sonic Hedgehog, a Novel Endogenous Damage Signal, Activates Multiple Beneficial Functions of Human Endometrial Stem Cells

Local endometrial stem cells play an important role in regulating endometrial thickness, which is an essential factor for successful embryo implantation and pregnancy outcomes. Importantly, defects in endometrial stem cell function can be responsible for thin endometrium and subsequent recurrent pregnancy losses. Therefore, many researchers have directed their efforts toward finding a novel stimulatory factor that can enhance the regenerative capacity of endometrial stem cells. Sonic hedgehog (SHH) is a morphogen that plays a key role in regulating pattern formation throughout embryonic limb development. In addition to this canonical function, we identified for the first time that SHH is actively secreted as a stem cell-activating factor in response to tissue injury and subsequently stimulates tissue regeneration by promoting various beneficial functions of endometrial stem cells. Our results also showed that SHH exerts stimulatory effects on endometrial stem cells via the FAK/ERK1/2 and/or phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways. More importantly, we also observed that endometrial stem cells stimulated with SHH showed markedly enhanced differentiation and migratory capacities and subsequent in vivo therapeutic effects in an endometrial ablation animal model.

GLI1 is increased in ovarian endometriosis and regulates migration, invasion and proliferation of human endometrial stromal cells in endometriosis

BACKGROUND

Endometriosis is a benign gynecological disorder which shares certain characteristics with malignant tumor like migration, invasion and proliferation. Glioma-associated oncogene homolog 1 (GLI1) has been implicated in some cancers including endometrial cancer, however, its role in endometriosis remains unknown.

METHODS

The aim of this study was to explore the expression pattern of GLI1 in endometriosis, and further investigate the effect of GLI1 regulation on human endometrial stromal cells. The expression of GLI1 in normal endometrium and ectopic tissues was analyzed by immunohistochemistry, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot. The Short hairpin RNA (ShRNA) intervention technique and GLI1 inhibitor GANT-61 were used to silence GLI1. The expression levels of GLI1, MMP2 and MMP9 was detected by qRT-PCR and western blot. The migration and invasion ability of human endometrial stromal cells was determined by wound healing assay and transwell migration/invasion assay. The viability and proliferation potentiality of cells was detected by MTT assays and colony formation assay, respectively.

RESULTS

We found that the expression of GLI1 mRNA and protein were significantly higher in ectopic endometrium from patients with endometriosis. Our analyses also show that GLI1 downregulation attenuated cells migration, invasion and proliferation abilities. What's more, reduced expression of GLI1 inhibited the expression of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9).

CONCLUSIONS

Our findings suggest that high levels of GLI1 may contribute to the development of endometriosis by promoting cell migration, invasion and proliferation involving regulation of MMP2 and MMP9 expression. Therefore, inhibition of GLI1 might be a novel potential therapeutic approach to the treatment of endometriosis, which sheds new light on our understanding of the pathogenesis of endometriosis.

Regulation of Hedgehog signaling Offers A Novel Perspective for Bone Homeostasis Disorder Treatment

The hedgehog (HH) signaling pathway is central to the regulation of bone development and homeostasis. HH signaling is not only involved in osteoblast differentiation from bone marrow mesenchymal stem cells (BM-MSCs), but also acts upstream within osteoblasts via the OPG/RANK/RANKL axis to control the expression of RANKL. HH signaling has been found to up-regulate parathyroid hormone related protein (PTHrP) expression in osteoblasts, which in turn activates its downstream targets nuclear factor of activated T cells (NFAT) and cAMP responsive element binding protein (CREB), and as a result CREB and NFAT cooperatively increase RANKL expression and osteoclastogenesis. Osteoblasts must remain in balance with osteoclasts in order to avoid excessive bone formation or resorption, thereby maintaining bone homeostasis. This review systemically summarizes the mechanisms whereby HH signaling induces osteoblast development and controls RANKL expression through PTHrP in osteoblasts. Proper targeting of HH signaling may offer a therapeutic option for treating bone homeostasis disorders.