PIM2 Promotes the Development of Ovarian Endometriosis by Enhancing Glycolysis and Fibrosis

Extracellular vesicle-packaged PKM2 from endometriotic stromal cells promotes endometrial collagen I deposition by inhibiting autophagy in endometriosis

Aberrant endometrial collagen I deposition during the implantation window impairs endometrial stromal cell (ESC) decidualization, which may contribute to lower pregnancy rate in endometriosis (EMs) patients with in vitro fertilization (IVF) treatment. However, the underlying mechanism of eutopic aberrant endometrium collagen I deposition in EMs remains unclear. In this study, we found increased endometrial collagen I and defective decidualization in the mid-secretory phase of EMs patients, while the level of eutopic ESCs' autophagy was decreased, which was an important mechanism of intracellular collagen degradation. Lower ESCs' autophagy level may cause the endometrial collagen I deposition in EMs. Furthermore, in vivo and in vitro studies showed that the extracellular vesicles derived from the ectopic ESCs of EMs patients (EMs-EVs) encapsulated higher PKM2 inhibited autophagy of the ESCs accompanied by an increase of collagen I. We also found that the constructed EMs-EVsAd-PKM2 with PKM2 overexpression inhibited ESCs' autophagy by activating the Akt/mTOR signaling pathway. And the expressions of PKM2, p-Akt and p-mTOR were also increased in the endometrium of EMs patients. Collectively, these data showed that EMs-EVs delivering PKM2 inhibited autophagy inducing aberrant endometrial collagen I deposition via the Akt/mTOR signaling pathway to impair decidualization, which provided a potential therapeutic target for improving the IVF pregnancy rate in EMs patients.

Endometriosis and Cytoskeletal Remodeling: The Functional Role of Actin-Binding Proteins

Endometriosis is a chronic, estrogen-dependent gynecological disorder characterized by the presence of endometrial-like tissue outside the uterine cavity. Despite its prevalence and significant impact on women's health, the underlying mechanisms driving the invasive and migratory behavior of endometriotic cells remain incompletely understood. Actin-binding proteins (ABPs) play a critical role in cytoskeletal dynamics, regulating processes such as cell migration, adhesion, and invasion, all of which are essential for the progression of endometriosis. This review aims to summarize current knowledge on the involvement of key ABPs in the development and pathophysiology of endometriosis. We discuss how these proteins influence cytoskeletal remodeling, focal adhesion formation, and interactions with the extracellular matrix, contributing to the unique mechanical properties of endometriotic cells. Furthermore, we explore the putative potential of targeting ABPs as a therapeutic strategy to mitigate the invasive phenotype of endometriotic lesions. By elucidating the role of ABPs in endometriosis, this review provides a foundation for future research and innovative treatment approaches.

AURKA inhibits the decidualization of the eutopic endometrium in endometriosis through nuclear factor-κB p65†

Endometriosis is an estrogen dependent disease, which is related to infertility. Decidualization is a prerequisite for successful implantation of human embryos, and endometriosis affects the occurrence of decidualization. However, the mechanism that affects decidualization in endometriosis is not fully understood. Here, we find that Aurora kinase A (AURKA) is upregulated in the eutopic endometrium of endometriosis. AURKA inhibits the decidualization of stromal cells in the eutopic endometrium of endometriosis. Furthermore, in animal experiments, AURKA promotes endometriosis and inhibits decidualization in mice with endometriosis, leading to decreased expression of decidualization markers, such as prolactin, insulin-like growth factor-binding protein-1, and desmin. Afterwards, we find that nuclear factor-κB (NF-κB) p65 is a new substrate of AURKA. AURKA interacts with p65 to promote its phosphorylation and nuclear translocation. Meanwhile, AURKA enhances the protein stability of p65 by prolonging its half-life. In summary, AURKA inhibits the decidualization of the eutopic endometrium in patients with endometriosis by regulating p65, which may provide new ideas for improving decidualization defect in patients with endometriosis.

The PKM2/HIF-1α Axis is Involved in the Pathogenesis of Endometriosis via TGF-β1 under Endometrial Polyps

BACKGROUND

Endometriosis patients exhibit a cancer-like glycolytic phenotype. The pyruvate kinase M2 (PKM2)/hypoxia-inducible factor-1 alpha (HIF-1α) axis plays important roles in glycolysis-related diseases, but its role in patients with endometrial polyps (EPs) combined with endometriosis has not been validated.

METHODS

EP samples were collected from patients with and without endometriosis. PKM2, HIF-1α, and transforming growth factor-beta 1 (TGF-β1) levels were detected by immunohistochemistry (IHC), quantitative polymerase chain reaction, western blotting, and/or immunofluorescence. Primary endometrial stromal cells (ESCs) and non-endometriotic patient-derived ESCs (NESCs) were isolated from patients with EP with or without endometriosis. PKM2 loss-of-function assays in ESCs and gain-of-function assays in NESCs were performed to assess the function of PKM2. The effects of PKM2 and TGF-β1 on the promoter activity of HIF-1α were determined by dual-luciferase reporter assay.

RESULTS

PKM2 was overexpressed in ESCs compared to NESCs. Furthermore, PKM2 knockdown repressed viability, decreased migration and invasion, and restrained glycolysis of ESCs, accompanied by reduced HIF-1α levels and weakened promoter activity of HIF-1α. In addition, PKM2 overexpression had the opposite effect on these indicators in NESCs. Of note, an anti-TGF-β1 Ab reversed the PKM2-overexpression-mediated effects on cell viability, migration, and invasion, but not glycolysis or HIF-1α promoter activity, in NESCs. Additionally, PKM2, HIF-1α, and TGF-β1 levels were higher in EP samples with endometriosis than in EP samples without endometriosis, and there were positive correlations between PKM2, HIF-1α, and TGF-β1 IHC scores in all EP samples.

CONCLUSIONS

PKM2/HIF-1α-axis-dependent glycolysis participates in the pathogenesis of EP combined with endometriosis by mediating TGF-β1 signaling.

The role of fibrosis in endometriosis: a systematic review

BACKGROUND

Fibrosis is an important pathological feature of endometriotic lesions of all subtypes. Fibrosis is present in and around endometriotic lesions, and a central role in its development is played by myofibroblasts, which are cells derived mainly after epithelial-to-mesenchymal transition (EMT) and fibroblast-to-myofibroblast transdifferentiation (FMT). Transforming growth factor-β (TGF-β) has a key role in this myofibroblastic differentiation. Myofibroblasts deposit extracellular matrix (ECM) and have contracting abilities, leading to a stiff micro-environment. These aspects are hypothesized to be involved in the origin of endometriosis-associated pain. Additionally, similarities between endometriosis-related fibrosis and other fibrotic diseases, such as systemic sclerosis or lung fibrosis, indicate that targeting fibrosis could be a potential therapeutic strategy for non-hormonal therapy for endometriosis.

OBJECTIVE AND RATIONALE

This review aims to summarize the current knowledge and to highlight the knowledge gaps about the role of fibrosis in endometriosis. A comprehensive literature overview about the role of fibrosis in endometriosis can improve the efficiency of fibrosis-oriented research in endometriosis.

SEARCH METHODS

A systematic literature search was performed in three biomedical databases using search terms for 'endometriosis', 'fibrosis', 'myofibroblasts', 'collagen', and 'α-smooth muscle actin'. Original studies were included if they reported about fibrosis and endometriosis. Both preclinical in vitro and animal studies, as well as research concerning human subjects were included.

OUTCOMES

Our search yielded 3441 results, of which 142 studies were included in this review. Most studies scored a high to moderate risk of bias according to the bias assessment tools. The studies were divided in three categories: human observational studies, experimental studies with human-derived material, and animal studies. The observational studies showed details about the histologic appearance of fibrosis in endometriosis and the co-occurrence of nerves and immune cells in lesions. The in vitro studies identified several pro-fibrotic pathways in relation to endometriosis. The animal studies mainly assessed the effect of potential therapeutic strategies to halt or regress fibrosis, for example targeting platelets or mast cells.

WIDER IMPLICATIONS

This review shows the central role of fibrosis and its main cellular driver, the myofibroblast, in endometriosis. Platelets and TGF-β have a pivotal role in pro-fibrotic signaling. The presence of nerves and neuropeptides is closely associated with fibrosis in endometriotic lesions, and is likely a cause of endometriosis-associated pain. The process of fibrotic development after EMT and FMT shares characteristics with other fibrotic diseases, so exploring similarities in endometriosis with known processes in diseases like systemic sclerosis, idiopathic pulmonary fibrosis or liver cirrhosis is relevant and a promising direction to explore new treatment strategies. The close relationship with nerves appears rather unique for endometriosis-related fibrosis and is not observed in other fibrotic diseases.

REGISTRATION NUMBER

N/A.

Integrin β3 enhances glycolysis and increases lactate production in endometriosis

BACKGROUND

Endometriosis (EMs) is a chronic disease characterized by endometrial-like tissue present outside of the uterus. Macrophages have been confirmed to participate in the development of EMs. Integrin β3 (ITGB3), a β-subunit of the integrin family, is crucial in tumor progression. In this study, we investigated the pivotal role of ITGB3 in endometrial stromal cells (ESCs) and its influence on the development of EMs, particularly focusing on the regulatory impact of macrophages.

METHODS

In this study, we used western blot, Real-time qPCR, Immunohistochemistry to detected the high expression of ITGB3 in ESCs. ITGB3-overexpression ESCs (ITGB3-OE) was constructed and detected by RNA-seq with normal ESCs. ATP and lactate expression assay, transwell migration assay, wound healing, cell adhesion assay and other molecular biology techniques were used to explore the potential mechanisms. In vivo, we constructed the EMs mouse model and injected with cilengitite to inhibit ITGB3.

RESULTS

Here, we found ITGB3 highly expressed in ectopic lesions in EMs. The increasing ITGB3 resulted in activating the glycolysis, which produced more ATP and lactate in ITGB3-OE. After culturing with lactate, the migration, proliferation and invasion ability of ESCs were enhanced, while the result in 2-DG was reversed. In vivo, the results showed that after antagonizing ITGB3, the number of ectopic lesions was decrease.

CONCLUSIONS

Our findings indicate that ITGB3 up-regulated by macrophages are able to regulate the glycolysis to promote the development of EMs and lactate enhances the ability of proliferation, migration, invasion and adhesion of EMs iv vivo and in vitro.

NEK2 promotes the development of ovarian endometriosis and impairs decidualization by phosphorylating FOXO1

Ovarian endometriosis is a common gynecological disease, and one of its most significant symptoms is infertility. In patients with endometriosis, defects in endometrial decidualization lead to impaired endometrial receptivity and embryo implantation, thus affecting early pregnancy and women's desire to have children. However, the mechanisms underlying the development of endometriosis and its associated defective decidualization are unclear. We find that NEK2 expression is increased in the ectopic and eutopic endometrium of patients with endometriosis. Meanwhile, NEK2 interacts with FOXO1 and phosphorylates FOXO1 at Ser184, inhibiting the stability of the FOXO1 protein. Importantly, NEK2-mediated phosphorylation of FOXO1 at Ser184 promotes cell proliferation, migration, invasion and impairs decidualization. Furthermore, INH1, an inhibitor of NEK2, inhibits the growth of ectopic lesions in mouse models of endometriosis and promotes endometrial decidualization in mouse models of artificially induced decidualization. Taken together, these findings indicate that NEK2 regulates the development of endometriosis and associated disorders of decidualization through the phosphorylation of FOXO1, providing a new therapeutic target for its treatment.

AURKA Enhances the Glycolysis and Development of Ovarian Endometriosis Through ERβ

Ovarian endometriosis (EMs) is a benign, estrogen-dependent gynecological disorder. Estrogen receptor beta (ERβ), a nuclear receptor for estradiol, plays an important role in the development of ovarian EMs. Here, we investigated the biological significance of aurora kinase A (AURKA) in ovarian EMs and the mechanism by which it regulates ERβ. We used immunohistochemical assays to verify that AURKA and ERβ were highly expressed in ectopic endometrial tissues. Cell proliferation and colony formation assays were used to demonstrate that AURKA promoted the proliferation of EMs cells. Wound-healing assay, Transwell migration assay, and Matrigel invasion assay further showed that AURKA enhanced the ability of EMs cells to migrate and invade. In addition, AURKA was shown to stimulate glycolysis in EMs cells by measuring the concentration of glucose and lactate in the cell supernatants. Moreover, the AURKA inhibitor alisertib was found to inhibit the progression of ovarian EMs and glycolysis in a mouse model of EMs by measuring ectopic tissues as well as by testing the peritoneal fluid of mice. Furthermore, coimmunoprecipitation assay showed that AURKA interacted with ERβ. The rescue experiments confirmed that AURKA regulated the development and glycolysis of ovarian EMs in an ERβ-dependent manner. AURKA contributed to the development of ovarian EMs by upregulating of ERβ. AURKA may represent a new target for the treatment of ovarian EMs.

The role of mitochondrial dynamics in the pathophysiology of endometriosis

AIM

Endometriosis is a chronic disease of reproductive age, associated with pelvic pain and infertility. Endometriotic cells adapt to changing environments such as oxidative stress and hypoxia in order to survive. However, the underlying mechanisms remain to be fully elucidated. In this review, we summarize our current understanding of the pathogenesis of endometriosis, focusing primarily on the molecular basis of energy metabolism, redox homeostasis, and mitochondrial function, and discuss perspectives on future research directions.

METHODS

Papers published up to March 31, 2023 in the PubMed and Google Scholar databases were included in this narrative literature review.

RESULTS

Mitochondria serve as a central hub sensing a multitude of physiological processes, including energy production and cellular redox homeostasis. Under hypoxia, endometriotic cells favor glycolysis and actively produce pyruvate, nicotinamide adenine dinucleotide phosphate (NADPH), and other metabolites for cell proliferation. Mitochondrial fission and fusion dynamics may regulate the phenotypic plasticity of cellular energy metabolism, that is, aerobic glycolysis or OXPHOS. Endometriotic cells have been reported to have reduced mitochondrial numbers, increased lamellar cristae, improved energy efficiency, and enhanced cell proliferation and survival. Increased mitochondrial fission and fusion turnover by hypoxic and normoxic conditions suggests an activation of mitochondrial quality control mechanisms. Recently, candidate molecules that influence mitochondrial dynamics have begun to be identified.

CONCLUSION

This review suggests that unique energy metabolism and redox homeostasis driven by mitochondrial dynamics may be linked to the pathophysiology of endometriosis. However, further studies are needed to elucidate the regulatory mechanisms of mitochondrial dynamics in endometriosis.