Promotion of BST2 expression by the transcription factor IRF6 affects the progression of endometriosis

Downregulated METTL3 Accumulates TERT Expression that Promote the Progression of Ovarian Endometriosis

BACKGROUND

Endometriosis is a complicated and enigmatic disease that significantly diminishes the quality of life for women affected by this condition. Increased levels of human telomerase reverse transcriptase (TERT) mRNA and telomerase activity have been found in the endometrium of these patients. However, the precise function of TERT in endometriosis and the associated biological mechanisms remain poorly understood.

METHODS

We analyzed TERT expression in ectopic endometrial (EC), eutopic endometrial (EU), and normal endometrial (NC) tissues. Human endometrial stromal cells (HESCs) were used to study the effects of TERT depletion and knockdown on cell behavior. We also assessed methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine (m6A) modification in TERT transcripts and its impact on mRNA stability and cell functions.

RESULTS

The current results indicate that TERT expression is elevated in EC tissue compared to both EU and NC. Depletion of TERT suppressed the proliferation and migration of HESCs, while TERT overexpression had the opposite effect. We found high levels of METTL3-mediated m6A modification in TERT transcripts, particularly in the coding sequence region, resulting in increased translation. However, EC tissues had lower m6A levels due to the downregulation of METTL3. Mechanistically, m6A modification mediated by METTL3 negatively regulates the stability of TERT mRNA in a YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)-dependent manner. Furthermore, METTL3 negatively regulated the proliferation and migration of HESCs.

CONCLUSIONS

Together, our study identified a new molecular mechanism that underlies the pathogenesis of endometriosis. Inhibition of m6A modification and of the METTL3/TERT axis may enhance cellular proliferation and migration, thereby contributing to the progression of endometriosis.

Endostatin-expressing endometrial mesenchymal stem cells inhibit angiogenesis in endometriosis through the miRNA-21-5p/TIMP3/PI3K/Akt/mTOR pathway

Endometriosis is a chronic inflammatory and neoangiogenic disease. Endostatin is one of the most effective inhibitors of angiogenesis. Mesenchymal stem cells (MSCs) have been investigated as compelling options for cell therapy. However, the effect and mechanism of action of endostatin-expressing endometrial MSCs (EMSCs) in endometriosis are unclear. Here, EMSCs were genetically modified to overexpress endostatin (EMSCs-Endo). A reduction in the angiogenic capacity of HUVECs was observed in vitro after treatment with EMSCs-Endo. EMSCs-Endo significantly suppressed endometriotic lesion growth in vivo. The limited efficacy was associated with suppressed angiogenesis. The miRNA-21-5p level and the levels of p-PI3K, p-mTOR, and p-Akt in HUVECs and mouse endometriotic lesions significantly decreased after treatment with EMSCs-Endo, whereas TIMP3 expression significantly increased. In summary, targeted gene therapy with EMSCs-Endo is feasible, and its efficacy in regulating endometriosis can be attributed to the inhibition of angiogenesis, suggesting that EMSCs could be used as promising vehicles for targeted gene therapy.

Lymphatic vessel: origin, heterogeneity, biological functions, and therapeutic targets

Lymphatic vessels, comprising the secondary circulatory system in human body, play a multifaceted role in maintaining homeostasis among various tissues and organs. They are tasked with a serious of responsibilities, including the regulation of lymph absorption and transport, the orchestration of immune surveillance and responses. Lymphatic vessel development undergoes a series of sophisticated regulatory signaling pathways governing heterogeneous-origin cell populations stepwise to assemble into the highly specialized lymphatic vessel networks. Lymphangiogenesis, as defined by new lymphatic vessels sprouting from preexisting lymphatic vessels/embryonic veins, is the main developmental mechanism underlying the formation and expansion of lymphatic vessel networks in an embryo. However, abnormal lymphangiogenesis could be observed in many pathological conditions and has a close relationship with the development and progression of various diseases. Mechanistic studies have revealed a set of lymphangiogenic factors and cascades that may serve as the potential targets for regulating abnormal lymphangiogenesis, to further modulate the progression of diseases. Actually, an increasing number of clinical trials have demonstrated the promising interventions and showed the feasibility of currently available treatments for future clinical translation. Targeting lymphangiogenic promoters or inhibitors not only directly regulates abnormal lymphangiogenesis, but improves the efficacy of diverse treatments. In conclusion, we present a comprehensive overview of lymphatic vessel development and physiological functions, and describe the critical involvement of abnormal lymphangiogenesis in multiple diseases. Moreover, we summarize the targeting therapeutic values of abnormal lymphangiogenesis, providing novel perspectives for treatment strategy of multiple human diseases.