Pigment Epithelium Derived Factor Inhibits the Growth of Human Endometrial Implants in Nude Mice and of Ovarian Endometriotic Stromal Cells In Vitro

Angiogenesis is a prerequisite for the formation and development of endometriosis. Pigment epithelium derived factor (PEDF) is a natural inhibitor of angiogenesis. We previously demonstrated a reduction of PEDF in the peritoneal fluid, serum and endometriotic lesions from women with endometriosis compared with women without endometriosis. Here, we aim to investigate the inhibitory effect of PEDF on human endometriotic cells in vivo and in vitro. We found that PEDF markedly inhibited the growth of human endometrial implants in nude mice and of ovarian endometriotic stromal cells in vitro by up-regulating PEDF expression and down-regulating vascular endothelial growth factor (VEGF) expression. Moreover, apoptotic index was significantly increased in endometriotic lesions in vivo and endometriotic stromal cells in vitro when treated with PEDF. In mice treated with PEDF, decreased microvessel density labeled by Von Willebrand factor but not by α-Smooth Muscle Actin was observed in endometriotic lesions. And it showed no increase in PEDF expression of the ovary and uterus tissues. These findings suggest that PEDF gene therapy may be a new treatment for endometriosis.     

Involvement of the Wnt/β-Catenin Signaling Pathway in the Cellular and Molecular Mechanisms of Fibrosis in Endometriosis

Background

During the development and progression of endometriotic lesions, excess fibrosis may lead to scarring, chronic pain, and altered tissue function. However, the cellular and molecular mechanisms of fibrosis in endometriosis remain to be clarified.

Objectives

The objective of the present study was to investigate whether the Wnt/β-catenin signaling pathway was involved in regulating the cellular and molecular mechanisms of fibrosis in endometriosis in vitro and to evaluate whether fibrosis could be prevented by targeting the Wnt/β-catenin pathway in a xenograft model of endometriosis in immunodeficient nude mice.

Methods

Seventy patients (40 with and 30 without endometriosis) with normal menstrual cycles were recruited. In vitro effects of small-molecule antagonists of the Tcf/β-catenin complex (PKF 115-584 and CGP049090) on fibrotic markers (alpha smooth muscle actin, type I collagen, connective tissue growth factor, fibronectin) and collagen gel contraction were evaluated in endometrial and endometriotic stromal cells from patients with endometriosis. In vitro effects of activation of the Wnt/β-catenin signaling pathway by treatment with recombinant Wnt3a on profibrotic responses were evaluated in endometrial stromal cells of patients without endometriosis. The effects of CGP049090 treatment on the fibrosis of endometriotic implants were evaluated in a xenograft model of endometriosis in immunodeficient nude mice.

Results

Treatment with PKF 115-584 and CGP049090 significantly decreased the expression of alpha smooth muscle actin, type I collagen, connective tissue growth factor and fibronectin mRNAs in both endometriotic and endometrial stromal cells with or without transforming growth factor-β1 stimulation. Both endometriotic and endometrial stromal cell-mediated contraction of collagen gels was significantly decreased by treatment with PKF 115-584 and CGP049090 as compared to that of untreated cells. The animal experiments showed that CGP049090 prevented the progression of fibrosis and reversed established fibrosis in endometriosis.

Conclusion

Aberrant activation of the Wnt/β-catenin pathway may be involved in mediating fibrogenesis in endometriosis.     

High-Throughput Sequencing Approach Uncovers the miRNome of Peritoneal Endometriotic Lesions and Adjacent Healthy Tissues

Accumulating data have shown the involvement of microRNAs (miRNAs) in endometriosis pathogenesis. In this study, we used a novel approach to determine the endometriotic lesion-specific miRNAs by high-throughput small RNA sequencing of paired samples of peritoneal endometriotic lesions and matched healthy surrounding tissues together with eutopic endometria of the same patients. We found five miRNAs specific to epithelial cells – miR-34c, miR-449a, miR-200a, miR-200b and miR-141 showing significantly higher expression in peritoneal endometriotic lesions compared to healthy peritoneal tissues. We also determined the expression levels of miR-200 family target genes E-cadherin, ZEB1 and ZEB2 and found that the expression level of E-cadherin was significantly higher in endometriotic lesions compared to healthy tissues. Further evaluation verified that studied miRNAs could be used as diagnostic markers for confirming the presence of endometrial cells in endometriotic lesion biopsy samples. Furthermore, we demonstrated that the miRNA profile of peritoneal endometriotic lesion biopsies is largely masked by the surrounding peritoneal tissue, challenging the discovery of an accurate lesion-specific miRNA profile. Taken together, our findings indicate that only particular miRNAs with a significantly higher expression in endometriotic cells can be detected from lesion biopsies, and can serve as diagnostic markers for endometriosis.     

In Vitro Effects of a Small-Molecule Antagonist of the Tcf/?-Catenin Complex on Endometrial and Endometriotic Cells of Patients with Endometriosis

Background

Our previous studies suggested that aberrant activation of Wnt/ß-catenin signaling might be involved in the pathophysiology of endometriosis. We hypothesized that inhibition of Wnt/ß-catenin signaling might result in inhibition of cell proliferation, migration, and/or invasion of endometrial and endometriotic epithelial and stromal cells of patients with endometriosis.

Objectives

The aim of the present study was to evaluate the effects of a small-molecule antagonist of the Tcf/ß-catenin complex (PKF 115–584) on cell proliferation, migration, and invasion of endometrial and endometriotic epithelial and stromal cells.

Methods

One hundred twenty-six patients (78 with and 48 without endometriosis) with normal menstrual cycles were recruited. In vitro effects of PKF 115–584 on cell proliferation, migration, and invasion and on the Tcf/ß-catenin target genes were evaluated in endometrial epithelial and stromal cells of patients with and without endometriosis, and in endometrial and endometriotic epithelial and stromal cells of the same patients.

Results

The inhibitory effects of PKF 115–584 on cell migration and invasion in endometrial epithelial and stromal cells of patients with endometriosis prepared from the menstrual phase were significantly higher than those of patients without endometriosis. Levels of total and active forms of MMP-9 were significantly higher in epithelial and stromal cells prepared from menstrual endometrium in patients with endometriosis compared to patients without endometriosis. Treatment with PKF 115–584 inhibited MMP-9 activity to undetectable levels in both menstrual endometrial epithelial and stromal cells of patients with endometriosis. The number of invasive cells was significantly higher in epithelial and stromal cells of endometriotic tissue compared with matched eutopic endometrium of the same patients. Treatment with PKF 115–584 decreased the number of invasive endometriotic epithelial cells by 73% and stromal cells by 75%.

Conclusions

The present findings demonstrated that cellular mechanisms known to be involved in endometriotic lesion development are inhibited by targeting the Wnt/β-catenin pathway.     

Endoglin (cd105) and S100A13 as markers of active angiogenesis in endometriosis

The aim of the present study was to evaluate the expression of the neo-angiogenic marker endoglin and its localization in tissues of normal and endometriotic patients as well as to compare it with one new angiogenic marker candidate - S100A13. Human recombinant S100A13 and endoglin 35mer synthetic peptide of the intracellular domain were used for the production of rabbit polyclonal antisera. The antisera were characterized for specificity, using immunoenzyme assay (ELISA), Western blot and immunohistochemistry. Formalin-fixed, paraffin-embedded tissue sections from normal endometrium, adenomyosis, ovarian endometriosis, eutopic endometrium from different endometriotic specimens were tested by immunohistochemistry. No endoglin specific staining was observed on the microvessels of the normal endometrium. In adenomyosis and ovarian endometriosis, the expression pattern was different - endoglin was expressed in all microvessels, with an even stronger expression in the myometrial compartment. Weak endoglin-positive staining was detected in the microvessels of eutopic endometrium specimens from different endometriosis cases. In comparison to endoglin, S100A13 exhibited a moderate expression in endometrial glands of normal endometrium, but strong expression in endometriotic specimens. No S100A13 extensive staining of the microvessels was observed in normal endometrium, while in endometriosis, it exhibited very intense staining in microvascular endothelia and less intense in the perivascular area of middle to large-sized vessels. This study for the first time shows over-expression of S100A13 in endometriosis. These data show that the expression of endoglin and S100A13 corresponds to the activation of the endothelial cells in the process of endometriotic angiogenesis, suggesting a beneficial role for these two molecules as markers for actively progressing endometriotic process.     

A new isoform of steroid receptor coactivator-1 is crucial for pathogenic progression of endometriosis

Endometriosis is considered to be an estrogen-dependent inflammatory disease, but its etiology is unclear. Thus far, a mechanistic role for steroid receptor coactivators (SRCs) in the progression of endometriosis has not been elucidated. An SRC-1-null mouse model reveals that the mouse SRC-1 gene has an essential role in endometriosis progression. Notably, a previously unidentified 70-kDa SRC-1 proteolytic isoform is highly elevated both in the endometriotic tissue of mice with surgically induced endometriosis and in endometriotic stromal cells biopsied from patients with endometriosis compared to normal endometrium. Tnf?/? and Mmp9?/? mice with surgically induced endometriosis showed that activation of tumor necrosis factor a (TNF-α)-induced matrix metallopeptidase 9 (MMP9) activity mediates formation of the 70-kDa SRC-1 C-terminal isoform in endometriotic mouse tissue. In contrast to full-length SRC-1, the endometriotic 70-kDa SRC-1 C-terminal fragment prevents TNF-α-mediated apoptosis in human endometrial epithelial cells and causes the epithelial-mesenchymal transition and the invasion of human endometrial cells that are hallmarks of progressive endometriosis. Collectively, the newly identified TNF-α-MMP9-SRC-1 isoform functional axis promotes pathogenic progression of endometriosis.     

Genome‐wide analysis of DNA methylation in endometriosis using Illumina Human Methylation 450 K BeadChips

Endometriosis is a common chronic gynecologic disorder characterized by the presence and growth of endometrial‐like tissue outside of the uterine cavity. Although the exact etiology remains unclear, epigenetic modifications, such as DNA methylation, are thought to contribute to the pathogenesis of endometriosis. Here, we used the Illumina Human Methylation 450 K BeadChip Array to analyze the genome‐wide DNA methylation profiles of six endometriotic lesions and six eutopic endometria from patients with ovarian endometriosis and six endometria of women without endometriosis. Compared with the eutopic endometria of women with endometriosis, 12,159 differentially methylated CpG sites and 375 differentially methylated promoter regions were identified in endometriotic lesions. GO analyses showed that these putative differentially methylated genes were primarily associated with immune response, inflammatory response, response to steroid hormone stimulus, cell adhesion, negative regulation of apoptosis, and activation of the MAPK activity. In addition, the expression levels of DNMT1, DNMT3A, DNMT3B, and MBD2 in endometriotic lesions and eutopic endometria were significantly decreased compared with control endometria. Our findings suggest that aberrant DNA methylation status in endometriotic lesions may play a significant role in the pathogenesis and progression of endometriosis.     

Potential Role of Semaphorin 3A and Its Receptors in Regulating Aberrant Sympathetic Innervation in Peritoneal and Deep Infiltrating Endometriosis

Previous studies have demonstrated the involvement of nerve repellent factors in regulation of the imbalanced innervation of endometriosis. This prospective study aims to explore the role of Sema 3A in regulating aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis. Ectopic endometriotic lesion were collected from patients with peritoneal endometriosis (n = 24) and deep infiltrating endometriosis of uterosacral ligament (n = 20) undergoing surgery for endometriosis. Eutopic endometrial samples were collected from patients with endometriosis (n = 22) or without endometriosis (n = 26). Healthy peritoneum (n = 13) from the lateral pelvic wall and healthy uterosacral ligament (n = 13) were obtained from patients who had no surgical and histological proof of endometriosis during hysterectomy for uterine fibroids. Firstly, we studied the immunostaining of Sema 3A, Plexin A1 and NRP-1 in all the tissues described above. Then we studied the nerve fiber density (NFD) of endometriosis-associated (sympathetic) nerve and para-endometriotic (sympathetic) nerve by double immunofluorescence staining. Finally we analyzed the relationship between expression of Sema 3A in stromal cells of endometriotic lesion and the aberrant innervation of endometriosis. Semi-quantitative immunostaining demonstrated that (1) Higher immunostaining of Sema 3A were found in the eutopic endometrial glandular epithelial cells from patients with endometriosis (p = 0.041) than those without endometriosis; (2) Sema 3A immunostaining was higher in glandular epithelial cells of peritoneal endometriosis (P<0.001) and deep infiltrating endometriotic lesions of uterosacral ligament (P = 0.028)compared with glandular epithelial cells of the endometrium from women with endometriosis, while its expression in ectopic stormal cells in both groups were significantly lower than that from eutopic endometrium of women without endometirosis (P<0.001, P<0.001, respectively). NFDs of Anti-TH (+) endometriosis-associated sympathetic nerve of peritoneal endometriosis (p<0.001) and deep endometriosis of uterosacral ligament (p<0.001) were significantly lower than NFDs of para-endometriotic sympathetic nerve. Our results suggest that Sema 3A may contribute to the regulation of aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis.     

Interleukin-12 inhibits development of ectopic endometriotic tissues in peritoneal cavity via activation of NK cells in a murine endometriosis model

Involvement of impaired peritoneal immunosurveillance systems has been well established in the pathology of endometriosis. On the other hand, it has been observed that peritoneal administration of IL-12 suppress development of endometriotic lesions in a mouse endometriosis model. We investigated the effect of peritoneal administration of IL-12 on the peritoneal immunosurveillance system regarding NK cells in the mouse model. Treating the endometrial-tissue challenged mice with IL-12 for 5 consecutive days, from day -2 to day 2 (implantation of the endometrial tissues was done on day 0), cytotoxicity of splenic NK cells was enhanced immediately after the administration, on day 3, and development of the endometriotic lesions was reduced on day 21. In vivo NK cell depletion by administration of anti-IL-2Rβ mAb resulted in reduction of the cytotoxicity of splenic NK cells concomitant with a significant attenuation of suppressive effect of IL-12 on development of endometriotic lesions. Therefore, it was suggested that IL-12 suppresses development of endometriotic lesions via activation of NK cells, and that NK cells are involved in the primary defense for the development of endometriotic lesions.     

<Emphasis Type="Italic">Lactobacillus gasseri</Emphasis> OLL2809 inhibits development of ectopic endometrial cell in peritoneal cavity via activation of NK cells in a murine endometriosis model

Involvement of impaired peritoneal immunosurveillance systems has been well established in the pathology of endometriosis. On the other hand, it has been observed that peritoneal administration of IL-12 suppress development of endometriotic lesions in a mouse endometriosis model. We investigated the effect of peritoneal administration of IL-12 on the peritoneal immunosurveillance system regarding NK cells in the mouse model. Treating the endometrial-tissue challenged mice with IL-12 for 5 consecutive days, from day -2 to day 2 (implantation of the endometrial tissues was done on day 0), cytotoxicity of splenic NK cells was enhanced immediately after the administration, on day 3, and development of the endometriotic lesions was reduced on day 21. In vivo NK cell depletion by administration of anti-IL-2Rβ mAb resulted in reduction of the cytotoxicity of splenic NK cells concomitant with a significant attenuation of suppressive effect of IL-12 on development of endometriotic lesions. Therefore, it was suggested that IL-12 suppresses development of endometriotic lesions via activation of NK cells, and that NK cells are involved in the primary defense for the development of endometriotic lesions.     

Macrophage Migration Inhibitory Factor Is Involved in Ectopic Endometrial Tissue Growth and Peritoneal-Endometrial Tissue Interaction In Vivo: A Plausible Link to Endometriosis Development

Pelvic inflammation is a hallmark of endometriosis pathogenesis and a major cause of the disease''s symptoms. Abnormal immune and inflammatory changes may not only contribute to endometriosis-major symptoms, but also contribute to ectopic endometrial tissue growth and endometriosis development. A major pro-inflammatory factors found elevated in peritoneal fluid of women with endometriosis and to be overexpressed in peritoneal fluid macrophages and active, highly vascularized and early stage endometriotic lesions, macrophage migration inhibitory factor (MIF) appeared to induce angiogenic and inflammatory and estrogen producing phenotypes in endometriotic cells in vitro and to be a possible therapeutic target in vivo. Using a mouse model where MIF-knock out (KO) mice received intra-peritoneal injection of endometrial tissue from MIF-KO or syngeneic wild type (WT) mice and vice versa, our current study revealed that MIF genetic depletion resulted in a marked reduction ectopic endometrial tissue growth, a disrupted tissue structure and a significant down regulation of the expression of major inflammatory (cyclooxygenease-2), cell adhesion (αv and β3 integrins), survival (B-cell lymphoma-2) and angiogenic (vascular endothelial cell growth) factorsrelevant to endometriosis pathogenesis, whereas MIF add-back to MIF-KO mice significantly restored endometriosis-like lesions number and size. Interestingly, cross-experiments revealed that MIF presence in both endometrial and peritoneal host tissues is required for ectopic endometrial tissue growth and pointed to its involvement in endometrial-peritoneal interactions. This study provides compelling evidence for the role of MIF in endometriosis development and its possible interest for a targeted treatment of endometriosis.     

CXCR4 or CXCR7 antagonists treat endometriosis by reducing bone marrow cell trafficking

Adult stem cells have a major role in endometrial physiology, including remodelling and repair. However, they also have a critical role in the development and progression of endometriosis. Bone marrow‐derived stem cells engraft eutopic endometrium and endometriotic lesions, differentiating to both stromal and epithelial cell fates. Using a mouse bone marrow transplantation model, we show that bone marrow‐derived cells engrafting endometriosis express CXCR4 and CXCR7. Targeting either receptor by the administration of small molecule receptor antagonists AMD3100 or CCX771, respectively, reduced BM‐derived stem cell recruitment into endometriosis implants. Endometriosis lesion size was decreased compared to vehicle controls after treatment with each antagonist in both an early growth and established lesion treatment model. Endometriosis lesion size was not effected when the local effects of CXCL12 were abrogated using uterine‐specific CXCL12 null mice, suggesting an effect primarily on bone marrow cell migration rather than a direct endometrial effect. Antagonist treatment also decreased hallmarks of endometriosis physiopathology such as pro‐inflammatory cytokine production and vascularization. CXCR4 and CXCR7 antagonists are potential novel, non‐hormonal therapies for endometriosis.     

The role of DJ-1 in the pathogenesis of endometriosis

Background

Endometriosis is an estrogen-dependent disease causing pelvic pain and infertility in 10% of reproductive-aged women. Despite a long history of the disease the pathogenesis of endometriosis is poorly understood. It is known that the expression of several proteins is either up or down regulated during endometriosis, but their precise role remains to be determined. DJ-1 is one such protein that is upregulated in eutopic endometrium of women having endometriosis suggesting that DJ-1 may be involved in the pathogenesis of endometriosis.

Methodology and Principal Findings

The role of DJ-1 in the pathogenesis of endometriosis was investigated. For this purpose the influence of DJ-1 on endometrial cell survival, attachment, proliferation, migration, and invasion either by overexpressing DJ-1 in normal endometrial cells or by knocking down DJ-1 expression in endometriotic cells using siRNA was investigated. The results indicated that DJ-1 protects endometrial cells from oxidative stress mediated apoptosis. Overexpression of DJ-1 in normal endometrial epithelial cells increases the adhesion on collagen type IV. However, no significant difference was observed incase of stromal cells. It was further demonstrated that DJ-1 regulates cell proliferation, migration, and invasion in normal endometrial and endometriotic epithelial cells whereas in the case of normal endometrial and endometriotic stromal cells, it regulates cell proliferation and invasion but not migration. Furthermore, the present study also indicated that DJ-1 regulates these cellular processes by modulating PI3K/Akt pathway by interacting and negatively regulating PTEN.

Conclusions

Abnormally high levels of DJ-1 expression may be involved in endometriosis, possibly by stimulating endometrial cell survival, proliferation, migration, and invasion.     

Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor

ABSTRACT: Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643.     

Progesterone and transforming growth factor-beta coordinately regulate suppression of endometrial matrix metalloproteinases in a model of experimental endometriosis.

Endometriosis is a benign, though aggressive, disease of the female reproductive tract that consists of endometrial stromal and epithelial cells growing at an extrauterine site. Although it is widely accepted that the majority of cases of endometriosis result from the ectopic implantation of refluxed menstrual tissue, the precise mechanisms by which this disease becomes established are not well understood. Matrix metalloproteinases (MMPs), enzymes which are important for extracellular matrix turnover, have recently been implicated in the development of endometriosis. MMPs appear to be overexpressed in endometriotic lesions, but expression levels decrease following successful medical therapy. Intriguingly, although transforming growth factor-beta (TGF-beta) mediates progesterone suppression of specific endometrial MMPs, this growth factor is overexpressed in women with endometriosis. In the current study, we used an established experimental model of endometriosis to explore MMP regulation by TGF-beta. Our findings indicate that blocking the action of TGF-beta opposes progesterone-mediated suppression of MMPs and blocks the ability of this steroid to prevent experimental endometriosis. However, we also show that the action of TGF-beta does not lead to a sustained suppression of MMPs as observed following progesterone treatment. Taken together, our data suggest that in the absence of a normal progesterone response, common in ectopic lesions of endometriosis, sensitivity to TGF-beta may be altered, resulting in a failure to regulate MMPs.     

Promoter methylation regulates estrogen receptor 2 in human endometrium and endometriosis

Steroid receptors in the stromal cells of endometrium and its disease counterpart tissue endometriosis play critical physiologic roles. We found that mRNA and protein levels of estrogen receptor 2 (ESR2) were strikingly higher, whereas levels of estrogen receptor 1 (ESR1), total progesterone receptor (PGR), and progesterone receptor B (PGR B) were significantly lower in endometriotic versus endometrial stromal cells. Because ESR2 displayed the most striking levels of differential expression between endometriotic and endometrial cells, and the mechanisms for this difference are unknown, we tested the hypothesis that alteration in DNA methylation is a mechanism responsible for severely increased ESR2 mRNA levels in endometriotic cells. We identified a CpG island occupying the promoter region (-197/+359) of the ESR2 gene. Bisulfite sequencing of this region showed significantly higher methylation in primary endometrial cells (n = 8 subjects) versus endometriotic cells (n = 8 subjects). The demethylating agent 5-aza-2'-deoxycytidine significantly increased ESR2 mRNA levels in endometrial cells. Mechanistically, we employed serial deletion mutants of the ESR2 promoter fused to the luciferase reporter gene and transiently transfected into both endometriotic and endometrial cells. We demonstrated that the critical region (-197/+372) that confers promoter activity also bears the CpG island, and the activity of the ESR2 promoter was strongly inactivated by in vitro methylation. Taken together, methylation of a CpG island at the ESR2 promoter region is a primary mechanism responsible for differential expression of ESR2 in endometriosis and endometrium. These findings may be applied to a number of areas ranging from diagnosis to the treatment of endometriosis.