Suppression of IL-1β-induced COX-2 expression by trichostatin A (TSA) in human endometrial stromal cells

Adenomyosis-associated infertility: an update of the immunological perspective

Adenomyosis is characterized by the invasion of endometrial glands and stroma into the myometrium. Its clinical manifestations often include dysmenorrhoea, excessive menstrual bleeding and infertility. Reduced pregnancy and live birth rates and an increased miscarriage rate are observed in women with adenomyosis. This review summarizes relevant advances and presents the underlying mechanisms of adenomyosis-associated infertility from an immunological perspective. Individuals with adenomyosis exhibit imbalances in immune cell subpopulations and the endocrine hormone-immunomodulatory axis. These immunological alterations may be key contributors to, or at least accomplices in, impaired endometrial receptivity. In addition, adenomyosis often occurs in association with endometriosis, uterine leiomyoma or endometrial polyps, which are pathogenetically relevant; their similarities and differences are discussed from an immunological perspective. The clinical diagnostic criteria of adenomyosis are not perfect, and the pathogenesis remains to be fully explored. Therefore screening for effective targets for early diagnosis and treatment at the cellular and molecular levels from the immunological point of view holds great potential, which will be of great importance in preventing this disease and improving women's reproductive health.

Epigenetic Dysregulation in Endometriosis: Implications for Pathophysiology and Therapeutics

Endometriosis is a prevalent gynecological condition associated with pelvic pain and infertility. Despite more than a century of research, the etiology of endometriosis still eludes scientific consensus. This lack of clarity has resulted in suboptimal prevention, diagnosis, and treatment options. Evidence of genetic contributors to endometriosis is interesting but limited; however, significant progress has been made in recent years in identifying an epigenetic role in the pathogenesis of endometriosis through clinical studies, in vitro cell culture experiments, and in vivo animal models. The predominant findings include endometriosis-related differential expression of DNA methyltransferases and demethylases, histone deacetylases, methyltransferases, and demethylases, and regulators of chromatin architecture. There is also an emerging role for miRNAs in controlling epigenetic regulators in the endometrium and endometriosis. Changes in these epigenetic regulators result in differential chromatin organization and DNA methylation, with consequences for gene expression independent of a genetic sequence. Epigenetically altered expression of genes related to steroid hormone production and signaling, immune regulation, and endometrial cell identity and function have all been identified and appear to play into the pathophysiological mechanisms of endometriosis and resulting infertility. This review summarizes and critically discusses early seminal findings, the ever-growing recent evidence of epigenetic contributions to the pathophysiology of endometriosis, and implications for proposed epigenetically targeted therapeutics.

Aberrant expression of histone deacetylase 8 in endometriosis and its potential as a therapeutic target

Purpose

To screen Zn2+-dependent histone deacetylase (HDAC) 1-11 in endometriotic cells and then evaluated the HDACs identified from the screening in ovarian endometrioma (OE) and deep endometriotic (DE) lesions, and to evaluate the therapeutic potential of HDAC8 inhibition in mice.

Methods

Quantification of gene and protein expression levels of HDAC1-11 in endometriotic cells stimulated by TGF-β1, and immunohistochemistry analysis of Class I HDACs and HDAC6 in OE/DE lesion samples. The therapeutic potential of HDAC8 inhibition was evaluated by a mouse model of deep endometriosis.

Results

The screening identified Class I HDACs and HDAC6 as targets of interest. Immunohistochemistry analysis found a significant elevation in HDAC8 immunostaining in both OE and DE lesions, which was corroborated by gene and protein expression quantification. For other Class I HDACs and HDAC6, their lesional expression was more subtle and nuanced. HDAC1 and HDAC6 staining was significantly elevated in DE lesions while HDAC2 and HDAC3 staining was reduced in DE lesions. Treatment of mice with induced deep endometriosis with an HDAC8 inhibitor resulted in significantly longer hotplate latency, a reduction of lesion weight by nearly two-thirds, and significantly reduced lesional fibrosis.

Conclusions

These findings highlight the progression-dependent nature of specific HDAC aberrations in endometriosis, and demonstrate, for the first titme, the therapeutic potential of suppressing HDAC8.

Corroborating evidence for aberrant expression of histone deacetylase 8 in endometriosis

Purpose

The aim of this study was to evaluate the dynamic change in staining of Class I HDACs and Hdac6 in lesions harvested serially from different time points in mice with induced endometriosis. In addition, the effect of Hdac8 activation as well as Hdac8 and Hdac6 inhibition on lesional progression and fibrogenesis was evaluated.

Methods

Immunohistochemistry analysis of Class I HDACs and Hdac6 in serially harvested lesion samples in mouse. Hdac8 activation, as well as Hdac6/8 inhibition, was evaluated in mice with induced endometriosis.

Results

We found a progressive increase in lesional staining of Hdac1, Hdac8, and Hdac6 and gradual decrease in Hdac2 staining and consistently reduced staining of Hdac3 during the course of lesional progression. The stromal Hdac8 staining correlated most prominently with all markers of lesional fibrosis. Hdac8 activation significantly accelerated the progression and fibrogenesis of endometriotic lesions. In contrast, specific inhibition of Hdac8 or Hdac6, especially of Hdac8, significantly hindered lesional progression and fibrogenesis.

Conclusions

Hdac8 is progressively and aberrantly overexpressed as endometriotic lesions progress. This, along with the documented HDAC1 upregulation in endometriosis and the overwhelming evidence for the therapeutic potentials of HDACIs, calls for further and in-depth investigation of epigenetic aberrations of endometriosis in general and of HDACs in particular.

Cracking the enigma of adenomyosis: an update on its pathogenesis and pathophysiology

In brief

Traditionally viewed as enigmatic and elusive, adenomyosis is a fairly common gynecological disease but is under-recognized and under-researched. This review summarizes the latest development on the pathogenesis and pathophysiology of adenomyosis, which have important implications for imaging diagnosis of the disease and for the development of non-hormonal therapeutics.

Abstract

Traditionally considered as an enigmatic disease, adenomyosis is a uterine disease that affects many women of reproductive age and is a contributing factor for pelvic pain, heavy menstrual bleeding (HMB), and subfertility. In this review, the new development in the pathogenesis and pathophysiology of adenomyosis has been summarized, along with their clinical implications. After reviewing the progress in our understanding of the pathogenesis and describing the prevailing theories, in conjunction with their deficiencies, a new hypothesis, called endometrial-myometrial interface disruption (EMID), which is backed by extensive epidemiologic data and demonstrated by a mouse model, is reviewed, along with recent data implicating the role of Schwann cells in the EMI area in the genesis of adenomyosis. Additionally, the natural history of adenomyotic lesions is elaborated and underscores that, in essence, adenomyotic lesions are fundamentally wounds undergoing repeated tissue injury and repair (ReTIAR), which progress to fibrosis through epithelial-mesenchymal transition, fibroblast-to-myofibroblast transdifferentiation, and smooth muscle metaplasia. Increasing lesional fibrosis propagates into the neighboring EMI and endometrium. The increased endometrial fibrosis, with ensuing greater tissue stiffness, results in attenuated prostaglandin E2, hypoxia signaling and glycolysis, impairing endometrial repair and causing HMB. Compared with adenomyosis-associated HMB, the mechanisms underlying adenomyosis-associated pain are less understood but presumably involve increased uterine contractility, hyperinnervation, increased lesional production of pain mediators, and central sensitization. Viewed through the prism of ReTIAR, a new imaging technique can be used to diagnose adenomyosis more accurately and informatively and possibly help to choose the best treatment modality.

Perioperative Suppression of Schwann Cell Dedifferentiation Reduces the Risk of Adenomyosis Resulting from Endometrial–Myometrial Interface Disruption in Mice

We have recently demonstrated that endometrial–myometrial interface (EMI) disruption (EMID) can cause adenomyosis in mice, providing experimental evidence for the well-documented epidemiological finding that iatrogenic uterine procedures increase the risk of adenomyosis. To further elucidate its underlying mechanisms, we designed this study to test the hypothesis that Schwann cells (SCs) dedifferentiating after EMID facilitate the genesis of adenomyosis, but the suppression of SC dedifferentiation perioperatively reduces the risk. We treated mice perioperatively with either mitogen-activated protein kinase kinase (MEK)/extracellular-signal regulated protein kinase (ERK) or c-Jun N-terminal kinase (JNK) inhibitors or a vehicle 4 h before and 24 h, 48 h and 72 h after the EMID procedure. We found that EMID resulted in progressive SCs dedifferentiation, concomitant with an increased abundance of epithelial cells in the myometrium and a subsequent epithelial–mesenchymal transition (EMT). This EMID-induced change was abrogated significantly with perioperative administration of JNK or MEK/ERK inhibitors. Consistently, perioperative administration of a JNK or a MEK/ERK inhibitor reduced the incidence by nearly 33.5% and 14.3%, respectively, in conjunction with reduced myometrial infiltration of adenomyosis and alleviation of adenomyosis-associated hyperalgesia. Both treatments significantly decelerated the establishment of adenomyosis and progression of EMT, fibroblast-to-myofibroblast trans-differentiation and fibrogenesis in adenomyotic lesions. Thus, we provide the first piece of evidence strongly implicating the involvement of SCs in the pathogenesis of adenomyosis induced by EMID.

Does tumour necrosis factor alpha-induced cyclooxygenase-2 expression lead to spontaneous abortion in Chlamydia trachomatis-infected women

Cytokines might be involved in spontaneous abortion by triggering inflammatory mediators (Cyclooxygenases (Cox)) leading to spontaneous abortion in Chlamydia trachomatis (Ct)-infected women. Study aimed to quantitate the expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-8) and Cox-2 in endometrial curettage tissue (ECT) of Spontaneous Aborters (SA). SA (n = 135) and 120 age-matched controls were enrolled from SJH, New Delhi, India. PCR was performed for detection of Ct MOMP gene (537 bp) in ECT. mRNA expression of pro-inflammatory cytokines and Cox-2 was assessed by real-time qPCR. Data was statistically evaluated. 14.8% SA were diagnosed as Ct-positive. Elevated expression of TNF-α, IFN-γ, IL-8 and Cox-2 was observed in Ct-infected SA. Ct-positive recurrent aborters showed significantly higher cytokine expression. Significant positive correlation was found between expression of Cox-2 and TNF-α in infected SA. Data suggested an increased expression of Th-1 cytokines, particularly TNF-α that induced Cox-2 expression in ECT, leading to spontaneous abortion in Ct-infected pregnant women.

The Pathogenesis of Endometriosis: Molecular and Cell Biology Insights

The etiopathogenesis of endometriosis is a multifactorial process resulting in a heterogeneous disease. Considering that endometriosis etiology and pathogenesis are still far from being fully elucidated, the current review aims to offer a comprehensive summary of the available evidence. We performed a narrative review synthesizing the findings of the English literature retrieved from computerized databases from inception to June 2019, using the Medical Subject Headings (MeSH) unique ID term "Endometriosis" (ID:D004715) with "Etiology" (ID:Q000209), "Immunology" (ID:Q000276), "Genetics" (ID:D005823) and "Epigenesis, Genetic" (ID:D044127). Endometriosis may origin from Müllerian or non-Müllerian stem cells including those from the endometrial basal layer, Müllerian remnants, bone marrow, or the peritoneum. The innate ability of endometrial stem cells to regenerate cyclically seems to play a key role, as well as the dysregulated hormonal pathways. The presence of such cells in the peritoneal cavity and what leads to the development of endometriosis is a complex process with a large number of interconnected factors, potentially both inherited and acquired. Genetic predisposition is complex and related to the combined action of several genes with limited influence. The epigenetic mechanisms control many of the processes involved in the immunologic, immunohistochemical, histological, and biological aberrations that characterize the eutopic and ectopic endometrium in affected patients. However, what triggers such alterations is not clear and may be both genetically and epigenetically inherited, or it may be acquired by the particular combination of several elements such as the persistent peritoneal menstrual reflux as well as exogenous factors. The heterogeneity of endometriosis and the different contexts in which it develops suggest that a single etiopathogenetic model is not sufficient to explain its complex pathobiology.

Effects of histone methyltransferase inhibition in endometriosis

Although the histone methyltransferase EZH2 and its product H3K27me3 are well studied in cancer, little is known about their role and potential as therapeutic targets in endometriosis. We have previously reported that endometriotic lesions are characterized by global enrichment of H3K27me3. Therefore, we aimed to (1) characterize the expression levels of EZH2 in endometriotic tissues; (2) assess H3K27me3 enrichment in candidate genes promoter regions; and (3) determine if pharmacological inhibition of EZH2 impacts migration, proliferation, and invasion of endometriotic cells. Immunohistochemistry of an endometriosis-focused tissue microarray was used to assess the EZH2 protein levels in tissues. Chromatin immunoprecipitation-qPCR was conducted to assess enrichment of H3K27me3 in candidate gene promoter regions in tissues. Immunofluorescence was performed to assess the effect of an EZH2-specific pharmacological inhibitor on H3K27me3 global enrichment in cell lines. To measure effects of the inhibitor in migration, proliferation, and invasion in vitro we used Scratch, BrdU, and Matrigel assays, respectively. Endometriotic lesions had significantly higher EZH2α nuclear immunostaining levels compared to eutopic endometrium from patients (glands, stroma) and controls (glands). H3K27me3 was enriched within promoter regions of candidate genes in some but not all of the endometriotic lesions. Inhibition of EZH2 reduced H3K27me3 levels in the endometriotic cells specifically, and also reduced migration, proliferation but not invasion of endometriotic epithelial cells (12Z). These findings support future preclinical studies to determine in vivo efficacy of EZH2 inhibitors as promising nonhormonal treatments for endometriosis, still an incurable gynecological disease.

Investigational drugs for the treatment of endometriosis, an update on recent developments

INTRODUCTION

Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis.

AREAS COVERED

This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents.

EXPERT OPINION

Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human.

Tranylcypromine, a lysine-specific demethylase 1 (LSD1) inhibitor, suppresses lesion growth and improves generalized hyperalgesia in mouse with induced endometriosis

BACKGROUND

Growing evidence indicates that endometriosis is an epigenetic disease. Encouragingly, histone deacetylases (HDACs) and DNA methyltransferases have been shown to be promising targets by numerous in vitro studies. However, only a few studies have shown promising effects of HDAC inhibition in preclinical studies in endometriosis. While lysine-specific demethylase 1 (LSD1) is recently found to be aberrantly expressed in endometriosis, and that the treatment of endometriotic stromal cells with tranylcypromine (TC), an LSD1 inhibitor, significantly reduced cellular proliferation, cell cycle progression, and invasiveness, the in vivo effect of TC treatment is currently lacking. This study sought to evaluate the effect of TC in a mouse model of endometriosis.

METHODS

Forty-seven female C57BL/6 mice were used in this experimentation. All mice, except those randomly selected to form Sham surgery (M) and specificity control (S) groups, received an endometriosis-inducing surgery. Group S was set up mainly to ensure that the reduced generalized hyperalgesia in mice treated with TC is not due to any possible analgesic effect of TC, but rather resulting from the treatment effect specific to endometriosis. Two weeks after the surgery, mice that received surgery were further divided randomly into 3 groups: 1) untreated group (U); 2) low-dose TC group (L); 3) high-dose TC group (H). Group S received the same treatment as in group H. Two weeks after treatment, all mice were sacrificed and their ectopic endometrial tissues were harvested and analyzed by immunohistochemistry analysis. Hotplate test was administrated to all mice before the induction, treatment and sacrifice. Lesion size, hotplate latency, immunoreactivity against markers of proliferation, angiogenesis, H3K4 methylation, and of epithelial-mesenchymal transition (EMT).

RESULTS

TC treatment significantly and substantially reduced the lesion size and improved generalized hyperalgesia in a dose-dependent fashion in mice with induced endometriosis. In addition, TC treatment resulted in reduced immunoreactivity to biomarkers of proliferation, angiogenesis, and H3K4 methylation, leading to arrested EMT and lesion growth.

CONCLUSION

In light of our previously reported reduced cellular proliferation, cell cycle progression and invasiveness resulting from the LSD1 inhibition in in vitro studies, our data strongly suggest that LSD1 is a promising therapeutic target for endometriosis.

TRIAL REGISTRATION

Not applicable.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 modulates DNA methylation and histone modification machinery proteins in human endometriotic cells

Endometriosis is an inflammatory gynecological disease of reproductive-age women. The prevalence of endometriosis is 5-10% in reproductive-age women. Modern medical treatments are directed to inhibit the action of estrogen in endometriotic cells. However, hormonal therapies targeting estrogen can be prescribed only for a short time because of their undesirable side effects. Recent studies from our laboratory, using human endometriotic epithelial cell line 12Z and stromal cell line 22B derived from red lesion, discovered that selective inhibition of prostaglandin E2 (PGE2) receptors EP2 and EP4 inhibits adhesion, invasion, growth, and survival of 12Z and 22B cells by modulating integrins, MMPs and TIMPs, cell cycle, survival, and intrinsic apoptotic pathways, suggesting multiple epigenetic mechanisms. The novel findings of the present study indicate that selective pharmacological inhibition of EP2 and EP4: (i) decreases expression of DNMT3a, DNMT3b, H3K9me3, H3K27me3, SUV39H1, HP1a, H3K27, EZH2, JMJD2a, HDAC1, HDAC3, MeCP2, CoREST and Sin3A; (ii) increases expression of H3K4me3, H3H9ac, H3K27ac; and (iii) does not modulate the expression of DNMT1, hSET1, LSD1, MBD1, p300, HDAC2, and JMJD3 epigenetic machinery proteins in an epithelial and stromal cell specific manner. In this study, we report for the first time that inhibition of PGE2-EP2/EP4 signaling modulates DNA methylation, H3 histone methylation and acetylation, and epigenetic memory machinery proteins in human endometriotic epithelial cells and stromal cells. Thus, targeting EP2 and EP4 receptors may emerge as long-term nonsteroidal therapy for treatment of active endometriotic lesions in women.

Rapid changes in histone deacetylases and inflammatory gene expression in expert meditators

BACKGROUND

A growing body of research shows that mindfulness meditation can alter neural, behavioral and biochemical processes. However, the mechanisms responsible for such clinically relevant effects remain elusive.

METHODS

Here we explored the impact of a day of intensive practice of mindfulness meditation in experienced subjects (n=19) on the expression of circadian, chromatin modulatory and inflammatory genes in peripheral blood mononuclear cells (PBMC). In parallel, we analyzed a control group of subjects with no meditation experience who engaged in leisure activities in the same environment (n=21). PBMC from all participants were obtained before (t1) and after (t2) the intervention (t2-t1=8h) and gene expression was analyzed using custom pathway focused quantitative-real time PCR assays. Both groups were also presented with the Trier Social Stress Test (TSST).

RESULTS

Core clock gene expression at baseline (t1) was similar between groups and their rhythmicity was not influenced in meditators by the intensive day of practice. Similarly, we found that all the epigenetic regulatory enzymes and inflammatory genes analyzed exhibited similar basal expression levels in the two groups. In contrast, after the brief intervention we detected reduced expression of histone deacetylase genes (HDAC 2, 3 and 9), alterations in global modification of histones (H4ac; H3K4me3) and decreased expression of pro-inflammatory genes (RIPK2 and COX2) in meditators compared with controls. We found that the expression of RIPK2 and HDAC2 genes was associated with a faster cortisol recovery to the TSST in both groups.

CONCLUSIONS

The regulation of HDACs and inflammatory pathways may represent some of the mechanisms underlying the therapeutic potential of mindfulness-based interventions. Our findings set the foundation for future studies to further assess meditation strategies for the treatment of chronic inflammatory conditions.

Proinflammatory cytokines induced altered expression of cyclooxygenase-2 gene results in unreceptive endometrium in women with idiopathic recurrent spontaneous miscarriage

OBJECTIVE

To investigate the expression pattern of proinflammatory, anti-inflammatory, and angiogenic cytokines and their effect on various mediators of endometrial receptivity in women with idiopathic recurrent spontaneous miscarriage (IRSM).

DESIGN

A prospective study.

SETTING

Tertiary care hospital and reproductive health research unit.

PATIENT(S)

Thirty-six women with IRSM (<35 years) and 30 fertile women as controls matched by age and body mass index undergoing sterilization.

INTERVENTION(S)

Endometrial biopsies in all women corresponding to the window of implantation.

MAIN OUTCOME MEASURE(S)

Assessment of endometrial expression of proinflammatory, anti-inflammatory, and angiogenic cytokines, mediators of matrix turnover and angiogenesis, markers of receptivity.

RESULT(S)

A statistical significantly higher level of proinflammatory cytokines, mediators of matrix turnover and angiogenesis, and a reduced expression of anti-inflammatory and angiogenic cytokines were observed in women with IRSM. Additionally, the markers of endometrial receptivity were poorly expressed in women with IRSM.

CONCLUSION(S)

Aberrant expression of proinflammatory, anti-inflammatory, and angiogenic cytokines during implantation window in women with IRSM is one of the key factors that adversely affect endometrial development, as evidenced by the inadequate expression of various endometrial receptivity markers.

TSA suppresses miR-106b-93-25 cluster expression through downregulation of MYC and inhibits proliferation and induces apoptosis in human EMC

Histone deacetylase (HDAC) inhibitors are emerging as a novel class of anti-tumor agents and have manifested the ability to decrease proliferation and increase apoptosis in different cancer cells. A significant number of genes have been identified as potential effectors responsible for the anti-tumor function of HDAC inhibitor. However, the molecular mechanisms of these HDAC inhibitors in this process remain largely undefined. In the current study, we searched for microRNAs (miRs) that were affected by HDAC inhibitor trichostatin (TSA) and investigated their effects in endometrial cancer (EMC) cells. Our data showed that TSA significantly inhibited the growth of EMC cells and induced their apoptosis. Among the miRNAs that altered in the presence of TSA, the miR-106b-93-25 cluster, together with its host gene MCM7, were obviously down-regulated in EMC cells. p21 and BIM, which were identified as target genes of miR-106b-93-25 cluster, increased in TSA treated tumor cells and were responsible for cell cycle arrest and apoptosis. We further identified MYC as a regulator of miR-106b-93-25 cluster and demonstrated its down-regulation in the presence of TSA resulted in the reduction of miR-106b-93-25 cluster and up-regulation of p21 and BIM. More important, we found miR-106b-93-25 cluster was up-regulated in clinical EMC samples in association with the overexpression of MCM7 and MYC and the down-regulation of p21 and BIM. Thus our studies strongly indicated TSA inhibited EMC cell growth and induced cell apoptosis and cell cycle arrest at least partially through the down-regulation of the miR-106b-93-25 cluster and up-regulation of it's target genes p21 and BIM via MYC.

Valproic acid and progestin inhibit lesion growth and reduce hyperalgesia in experimentally induced endometriosis in rats

Accumulating evidence suggests that endometriosis is an epigenetic disease. This study was designed to evaluate the effect of valproic acid (VPA) and progesterone (P4) in a rat model of endometriosis on serum tumor necrosis factor-α (TNF-α) levels, hot plate and tail-flick latencies, lesion size, and body weight. We used 77 adult female rats, and endometriosis was induced by autotransplanting pieces of uterus (ENDO) or fat (SHAM) to the pelvic cavity. The BLANK group received no surgery. After 2 weeks, the ENDO group was further divided, randomly, into 5 groups, receiving, respectively, treatment with low- and high-dose VPA, P4 alone, VPA + P4, and no treatment. The SHAM rats received no treatment. The BLANK rats were further divided into 2 groups, one received VPA treatment and the other, no treatment. After 4 weeks, all rats were sacrificed. Response latency in hot plate and tail-flick tests, body weight, and serum TNF-α levels were measured before the surgery, before and after the treatment, along with lesion size. We found that induced endometriosis reduced response latency. ENDO rats receiving VPA and/or P4 treatment had significantly reduced lesion size as compared with untreated ones, and had significantly improved response to noxious thermal stimuli. They also had significantly increased weight gain. Serum TNF-α levels increased following surgery but eventually decreased regardless of treatment or not. In conclusion, VPA is well tolerated. Treatment with VPA significantly reduces lesion growth and improves sensitivity to nocifensive stimuli. The improvement is specific to endometriosis-induced hyperalgesia. Thus, histone deacetylase inhibitors may be a promising therapeutics for treating endometriosis.

Pyrrolidine dithiocarbamate attenuates nuclear factor-ĸB activation, cyclooxygenase-2 expression and prostaglandin E2 production in human endometriotic epithelial cells

BACKGROUND

The nuclear factor-κB (NF-κB) pathway activates many of the target genes that are critical to the initiation and establishment of endometriosis. We sought to examine the potential application of pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, in the treatment of endometriosis.

METHODS

The phosphorylation of IκB, expression of nuclear p65 protein and NF-κB DNA binding in endometriotic epithelial cells (EECs), endometriotic eutopic epithelial cells (EuECs) and normal epithelial cells (NECs) were detected by Western blot analysis and electrophoretic mobility shift assay. Cyclooxgenase-2 (COX-2) gene and protein expressions in EECs were measured by RT-PCR and Western blot analysis. Prostaglandin E(2) (PGE(2)) production of EECs was measured by ELISA.

RESULTS

PDTC in the absence or presence of tumor necrosing factor-α (TNF-α) showed stronger inhibitory effects on IκB phosphorylation, expression of nuclear p65 protein and NF-κB DNA-binding activity in EECs than in EuECs or NECs. Pretreatment of EECs with PDTC resulted in a dose-dependent reduction in the TNF-α-induced expressions of COX-2 at gene and protein levels, as well as a reduction of PGE(2) synthesis.

CONCLUSION

PDTC may represent a novel therapeutic strategy for treatment of endometriosis.

Interleukin-1β induces cyclooxygenase-2 expression and promotes the invasive ability of human mesenchymal stem cells derived from ovarian endometrioma

OBJECTIVE

To elucidate the role of interleukin-1β (IL-1β) on cyclooxygenase-2 (COX-2) expression and invasion of endometrioma-derived ectopic endometrial mesenchymal stem cells (EN-MSCs) and to develop an organoid method to study the invasive ability of endometrial cells.

DESIGN

Gene expression and cell functions.

SETTING

Kaohsiung Medical University, Kaohsiung, Taiwan.

PATIENT(S)

Human eutopic and endometrioma-derived ectopic EN-MSCs were isolated from different endometrium biopsy samples after surgery for treatment of endometriosis.

INTERVENTION(S)

Chemical treatment of cell culture.

MAIN OUTCOME MEASURE(S)

Comparative analysis of genomewide messenger RNA (mRNA) expression, cell migration, and invasion abilities in cell culture and organoid culture.

RESULT(S)

Gene expression profiles revealed that the expression of IL-1β and COX-2 were statistically significantly higher in ectopic EN-MSCs compared with eutopic EN-MSCs. These enhanced expressions coincided with a greater ability for cell migration and invasion in ectopic EN-MSCs and were found to be distinctly regulated by IL-1β which up-regulates COX-2 expression. Furthermore, IL-1β treatment of ectopic EN-MSCs in organoids was found to induce tentacle-like structures that mimicked cell invasion.

CONCLUSION(S)

These results indicate that COX-2 and IL-1β regulate the invasion ability of ectopic EN-MSCs. The information may be useful for developing a new therapeutic strategy for endometriosis. The ex vivo invasion model will be useful for characterization of EN-MSCs.

Anti-inflammatory effects of Cynanchum taiwanianum rhizome aqueous extract in IL-1β-induced NRK-52E cells

CONTEXT

Cynanchum taiwanianum T. Yamaza (Asclepiadaceae) is a medicinal herb used in folk medicine for the treatment of several inflammation-related diseases such as hepatitis and dermatitis in Taiwan.

OBJECTIVE

In the present study, we investigated the anti-inflammatory effect of C. taiwanianum T. Yamaza rhizome aqueous extract (CTAE).

MATERIALS AND METHODS

The present study investigated the anti-inflammatory effect of CTAE using IL-1β-induced NRK-52E cells. Production of NO and PGE(2) by ELISA, the mRNA and protein expression of iNOS and COX-2, phosphorylation of IκBα, and activation of NF-κB by RT-PCR and western blotting were determined.

RESULTS

The CTAE significantly (P < 0.05) inhibited NO and PGE(2) production (decreased by 46.1% and 51%, respectively), and also significantly (P < 0.05) attenuated protein and mRNA expression of iNOS and COX-2 (decreased by 90% and 55% for iNOS and by 72% and 74%% for COX-2, respectively) in IL-1β-induced NRK-52E cells, in a dose-dependent manner, without obvious cytotoxic effects. Furthermore, the CTAE suppressed the NF-κB nuclear translocation, in terms of inhibition of IκBα phosphorylation.

DISCUSSION AND CONCLUSION

Our results provided evidence for its folkloric uses and suggest that the anti-inflammatory activities of CTAE may result from the inhibition of inflammatory mediators, such as NO and PGE(2), and an upstream suppression of a NF-κB-dependent mechanism, might be involved.

Recurrence of endometriosis and its control

BACKGROUND Although surgery is currently the treatment of choice for managing endometriosis, recurrence poses a formidable challenge. To delay or to eliminate the recurrence is presently an unmet medical need in the management of endometriosis. To this end, proposals to investigate patterns of recurrence, to develop biomarkers for recurrence and to carry out biomarker-based intervention have been made. METHODS Publications pertaining to the recurrence of endometriosis and its related yet unaddressed issues were identified through MEDLINE. The reported recurrence rates, risk factors for recurrence, the effects of post-operative medication and causes of recurrence were reviewed and synthesized. In addition, several poorly explored issues such as time hazard function and mechanisms of recurrence were reviewed. Approaches to the development of biomarkers for recurrence and future intervention are discussed. RESULTS The reported recurrence rate was high, estimated as 21.5% at 2 years and 40-50% at 5 years. Few risk factors for recurrence have been consistently identified, and the evidence on the efficacy of the post-operative use of medication was scanty. The investigation on the patterns of recurrence may provide us with new insight into the possible mechanisms of recurrence and its control. The attempt to identify biomarkers for recurrence has started only very recently. CONCLUSIONS Much research is needed to better understand the patterns of recurrence and risk factors, and to develop biomarkers. One top priority is to develop biomarkers for recurrence, which may provide much needed clues to the possible mechanisms underlying recurrence and would allow the identification of patients with high recurrence risk, and permit for targeted intervention.

Peroxisome proliferator-activated receptor-gamma and retinoid X receptor agonists synergistically suppress proliferation of immortalized endometrial stromal cells

OBJECTIVE

To examine whether trichostatin A (TSA), a histone deacetylase inhibitor (HDACI), can induce up-regulation of peroxisome proliferator-activating receptor gamma (PPAR gamma) and to see whether LG100268, a retinoid X receptor (RXR) ligand, can inhibit proliferation of endometriotic cells alone or in synergy with ciglitazone, a PPAR gamma agonist.

DESIGN

One endometrial stromal cell line and two endometriotic cell lines used as a model system: Western blot analysis to determine whether TSA can up-regulate PPAR gamma expression, and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) proliferation assay to see whether ciglitazone and LG100268 have any antiproliferative effects individually or jointly.

SETTING

Academic.

PATIENT(S)

None.

INTERVENTION(S)

Culture of immortalized endometrial and endometriotic cell lines with TSA, or ciglitazone or LG100268.

MAIN OUTCOME MEASURE(S)

PPAR gamma protein expression levels in cells treated with or without TSA, and number of viable cells treated with or without ciglitazone, LG100268, or both.

RESULT(S)

The TSA treatment resulted in up-regulation of PPAR gamma expression in all cell lines in a dose-dependent fashion. Both ciglitazone and LG100268 inhibited proliferation in a dose-dependent manner, and the antiproliferative effects appeared to be synergistic. In addition, endometriotic cells were more sensitive than endometrial stromal cells to LG100268 treatment.

CONCLUSION(S)

The up-regulation of PPAR gamma induced by TSA indicates that the action of HDACIs also includes the PPAR gamma signaling pathway, suggesting that the activation of PPAR gamma is a desirable way to contain endometriosis phenotypes. The higher sensitivity of endometriotic cells than their endometrial counterpart to LG100268 treatment suggests that the sensitivity differential could be exploited effectively to eradicate unwanted ectopic endometrial tissues while minimizing the collateral damage to the normal endometrial tissues.

Cyclooxygenase-2 overexpression in ovarian endometriomas is associated with higher risk of recurrence

Cyclooxegenase-2 expression was evaluated by immunohistochemistry in endometrioma tissue samples taken from 109 patients, of whom 53 had recurrence by 30 months after surgery and 56 did not. Cyclooxegenase-2 overexpression, along with previous medical treatment of endometriosis and the presence of adhesion, is predictive of recurrence of ovarian endometrioma within 30 months after surgery, with a resultant sensitivity of 72.5% and a specificity of 72.4%, suggesting that there are intrinsic and identifiable biomarkers that confer recurrence risk.

Trichostatin A, a histone deacetylase inhibitor, attenuates invasiveness and reactivates E-cadherin expression in immortalized endometriotic cells

The objective of this study is to determine whether trichostatin A (TSA) can suppress the invasiveness of 2 endometriotic cell lines known to be invasive and E-cadherin negative. The membrane invasion culture system was used to assess cell invasion using invasive and a noninvasive bladder cancer cell lines as positive and negative controls, respectively. The E-cadherin mRNA levels and protein expression were evaluated by real-time reverse transcriptase polymerase chain reaction and Western blot analysis, respectively. The authors found that TSA attenuates the invasiveness of 2 cell lines in the presence or absence of tumor necrosis factor alpha (TNFalpha) stimulation. In addition, TSA treatment reactivates E-cadherin gene and protein expression in these cell lines. These results, along with recent findings that TSA suppresses proliferation, interleukin-1 beta-induced cyclo-oxygenase 2 expression, and constitutive or TNFalpha-stimulated nuclear factor kappa B activation in endometrial and endometriotic cells, makes histone deacetylase inhibitors a promising class of compounds for novel and more effective medical treatment of endometriosis, especially given the mounting evidence that endometrios be an epigenetic disease.

Histone deacetylase inhibitors trichostatin A and valproic acid induce cell cycle arrest and p21 expression in immortalized human endometrial stromal cells

OBJECTIVE

Following our observation that histone deacetylase inhibitors (HDACIs) trichostatin A (TSA) and valproic acid (VPA) can suppress proliferation of endometrial stromal cells, we sought to determine whether TSA and VPA do so by inducing cell cycle arrest and p21 expression.

STUDY DESIGN

A recently established immortalized endometrial stromal cell line was treated with TSA, VPA, and/or all-trans retinoic acid (ATRA) and the consequent cell cycle progression was measured by flow cytometry and p21 protein expression by Western blot analysis.

RESULTS

Both TSA and VPA induced cell cycle arrest and p21 expression in a concentration-dependent manner. Treatment with ATRA alone also induced cell cycle arrest and moderate increase in p21 expression but joint treatment of ATRA and TSA/VPA did not further enhance cell cycle arrest as compared with TSA/VPA treatment alone.

CONCLUSIONS

HDACIs suppress proliferation of endometrial stromal cells through induction of cell cycle arrest and possibly also through apoptosis as well. RA also induces cell cycle arrest but it does not synergize with HDACIs in inducing cell cycle arrest. HDACIs may be promising compounds for treating endometriosis.