Apoptosis through regulation of Bcl-2, Bax and Mcl-1 expressions in endometriotic cyst lesions and the endometrium of women with moderate to severe endometriosis

Molecular Mechanisms of Endometriosis Revealed Using Omics Data

Endometriosis is a gynecological disorder prevalent in women of reproductive age. The primary symptoms include dysmenorrhea, irregular menstruation, and infertility. However, the pathogenesis of endometriosis remains unclear. With the advent of high-throughput technologies, various omics experiments have been conducted to identify genes related to the pathophysiology of endometriosis. This review highlights the molecular mechanisms underlying endometriosis using omics. When genes identified in omics experiments were compared with endometriosis disease genes identified in independent studies, the number of overlapping genes was moderate. However, the characteristics of these genes were found to be equivalent when functional gene set enrichment analysis was performed using gene ontology and biological pathway information. These findings indicate that omics technology provides invaluable information regarding the pathophysiology of endometriosis. Moreover, the functional characteristics revealed using enrichment analysis provide important clues for discovering endometriosis disease genes in future research.

Endometriosis Cell Proliferation Induced by Bone Marrow Mesenchymal Stem Cells

Endometriosis is an estrogen-dependent gynecological disorder that affects 10% of reproductive-aged women and causes pelvic pain and infertility. Bone marrow-derived stem cells (BMDCs) are known to engraft endometriosis in association with lesion growth; however, they do not undergo significant clonal expansion. The indirect effects of BMDCs on endometriosis growth and cell proliferation are not well characterized. Here, we demonstrate that BMDCs' co-culture increased endometrial stromal cell proliferation. In vitro studies using endometrial cells showed that BMDCs increased cell proliferation and activation of CDK1 in both an endometriosis cell line and primary endometrial stromal cells from women with endometriosis, however not in normal endometrial cells. In vivo studies using a mouse model of endometriosis showed increased CDK1+ expression associated with engrafted GFP + BMDCs. These results suggest that endometrial cell proliferation is induced by stem cell-derived trophic factors leading to the growth of endometriotic lesions. Targeting the specific signaling molecules secreted by BMDC may lead to novel therapeutic strategies for controlling cell proliferation in endometriosis.

Effect of Dehydrocostus Lactone Isolated from the Roots of Aucklandia lappa on the Apoptosis of Endometriotic Cells and the Alternative Activation of Endometriosis-Associated Macrophages

The roots of Aucklandia lappa have been used in traditional medicine in Asia to treat inflammation and diseases associated with pain, including endometriosis. The aim of this study was to investigate the anti-endometriotic effect of dehydrocostus lactone, an active compound in A. lappa roots, using human endometriotic cells and macrophages stimulated by these cells. Dehydrocostus lactone induced apoptotic cell death in 12Z human endometriotic cells. Dehydrocostus lactone stimulated the activation of caspase-3, -8, and -9, while caspase inhibitors significantly reversed the dehydrocostus lactone-induced cell death in 12Z cells. In addition, dehydrocostus lactone decreased the production of PGE₂ and neurotrophins (BDNF, NGF, NT3, and NT4/5), which are regarded as endometriosis-associated pain factors in human endometriotic cells. Moreover, dehydrocostus lactone inhibited the expression of M2 markers (CD206, and Trem-2), IL-10, VEGF, and MMP-2/-9 in endometriosis-associated macrophages (EAMs). Furthermore, dehydrocostus lactone inhibited the Akt and NFκB pathways in both endometriotic cells and EAMs. Taken together, our findings suggest that dehydrocostus lactone, an active compound of A, lappa, has anti-endometriotic activities via induction of apoptosis and downregulation of pain factors in endometriotic cells and inhibition of the alternative activation of EAMs.

Immunoexpression of DNA fragmentation factor 40, DNA fragmentation factor 45, and B-cell lymphoma 2 protein in normal human endometrium and uterine myometrium depends on menstrual cycle phase and menopausal status

INTRODUCTION

DNA fragmentation factors 40 and 45 (DFF40 and DFF45) are final executors of apoptosis, and B-cell lymphoma 2 (Bcl-2) is a well-recognized apoptosis inhibitor. We aimed to evaluate DFF40, DFF45 and Bcl-2 immunoexpression in the normal human endometrium with respect to the glandular and stromal layer and in uterine myometrium.

MATERIAL AND METHODS

DFF40, DFF45, and Bcl-2 expression was assessed via immunohistochemistry in the endometrium and myometrium collected postmenopausally and premenopausally during the proliferative and secretory phases of the menstrual cycle.

RESULTS

Compared to the myometrium and stroma, endometrial glands showed the highest DFF40 and DFF45 expression in pre- and postmenopausal specimens. DFF45, but not DFF40, glandular expression dependent on menstrual cycle phase and DFF40 and DFF45 scoring was significantly lower in postmenopausal specimens. Significantly higher Bcl-2 expression was observed in proliferative glandular endometrium compared to secretory and postmenopausal specimens. No cycle- or menopause-dependent changes were reported for stromal or myometrial DFF40, DFF45 or Bcl-2 expression. DFF40, DFF45 and Bcl-2 expression was independent of age, age at menarche and menopause, BMI, menstrual cycle and menses lengths, parity and gravidity.

CONCLUSIONS

The study provides important evidence regarding menstrual cycle-dependent changes in the expression of DFF40, DFF45 and Bcl-2 in the normal human endometrium, especially in the glandular layer, and shows that their levels are stable in the normal uterine myometrium.

Regulation of apoptotic pathways during endometriosis: from the molecular basis to the future perspectives

PURPOSE

Endometriosis is defined as the presence of endometrial-like endometrial cells, glands and stroma outside the uterus, causing a strong inflammatory-like microenvironment in the affected tissue. This may provoke a breakdown in the peritoneal cavity homeostasis, with the consequent processes of immune alteration, documented by peripheral mononuclear cells recruitment and secretion of inflammatory cytokines in early phases and of angiogenic and fibrogenic cytokines in the late stages of the disease. Considering the pivotal role of interaction between immune and endometriotic cells, in this paper, we aim to shed light about the role of apoptosis pathways in modulating the fine-regulated peritoneal microenvironment during endometriosis.

METHODS

Narrative overview, synthesizing the findings of literature retrieved from searches of computerized databases.

RESULTS

In normal conditions, endometriotic cells, refluxed through the fallopian tubes into the peritoneal cavity, should be attacked and removed by phagocytes and NK cells. During endometriosis, the breakdown of peritoneal homeostasis causes the failure of scavenging mechanisms, allowing the survival of endometriotic cells. The consequent so-called "immunoescaping" of endometriotic cells could be due, at least in part, to the reduction of apoptotic-mediated pathways previously described.

CONCLUSION

Considering the large amount of evidence retrieved from in vitro as well as in vivo models, the reduced apoptosis of endometriotic cells together with the increased apoptosis of peritoneal fluid mononuclear cells may address the peritoneal homeostasis to a permissive environment for the progression of the disease.

Activated Hippo/Yes-Associated Protein Pathway Promotes Cell Proliferation and Anti-apoptosis in Endometrial Stromal Cells of Endometriosis

CONTEXT

The imbalance in cell proliferation and apoptosis is considered an important role in the pathogenesis of endometriosis, but the exact mechanisms remains unclear. A newly established signaling pathway–Hippo/Yes-associated protein (YAP) pathway plays a critical role in the proliferation and apoptosis processes. However, studies focusing on Hippo/YAP pathway and endometriosis are lacking.

OBJECTIVE

The objective was to explore the function of the Hippo/YAP pathway in endometriosis.

SETTING AND DESIGN

The expression of YAP was first investigated in endometrium of women with or without endometriosis. The role of YAP in cell proliferation and apoptosis is identified by transfection of endometrial stromal cells (ESCs) in vitro, subsequent Verteporfin treatments in eutopic ESCs in vitro, and endometriosis animal model of nude mice in vivo.

RESULTS

Our results revealed that increased expression of YAP and decreased expression of p-YAP in ectopic and eutopic endometrium compared with normal endometrium. YAP knockdown in eutopic ESCs decreased cell proliferation and enhanced cell apoptosis companied with decreased expression of TEAD1, CTGF, and B-cell lymphoma/leukemia (BCL)-2; whereas overexpression of YAP resulted in increased proliferation and decreased apoptosis of normal ESCs with increased expression of TEAD1, CTGF, and BCL-2. By chromatin immunoprecipitation qPCR CTGF and BCL-2 were identified as directly downstream target genes of YAP-TEAD1 active complex. Eutopic ESCs treated with Verteporfin revealed decreased proliferation and enhanced apoptosis whereas in endometriosis animal models of nude mice treated with Verteporfin, the size of endometriotic lesions was significantly reduced.

CONCLUSIONS

Our study suggests that the Hippo/YAP-signaling pathway plays a critical role in the pathogenesis of endometriosis and should present a novel therapeutic method against endometriosis.