Important role of collective cell migration and nerve fiber density in the development of deep nodular endometriosis

Overview of crosstalk between stromal and epithelial cells in the pathogenesis of adenomyosis and shared features with deep endometriotic nodules

Since the first description of adenomyosis more than 150 years ago, multiple hypotheses have attempted to explain its pathogenesis. Indeed, research over recent years has greatly enhanced our knowledge of the underlying causes. This has opened up avenues for the development of strategies for both disease prevention and treatment of its main symptoms, such as pelvic pain, heavy menstrual bleeding, and infertility. However, the current means are still largely ineffective, so it is vital that we shed light on the pathways involved. Dysregulated mechanisms and aberrant protein expression have been identified as contributing factors in interactions between endometrial epithelial and stromal cells, ultimately leading to the growth of adenomyotic lesions. These include collective cell migration, epithelial-to-mesenchymal transition, hormonal influence, and signaling from non-coding RNAs and extracellular vesicles. We provide a concise summary of the latest insights into the crosstalk between glands and stroma in ectopic adenomyotic lesion formation. While there is an abundance of literature on similarities between adenomyosis and deep endometriosis, there are insufficient data on the cytochemical, molecular, and pathogenetic mechanisms of these two disorders. However, various shared features, including alterations of cell adhesion molecules, abnormal hormone regulation, and the presence of cancer-driving mutations and epigenetic modifications, have been identified. Nevertheless, the pathogenic mechanisms that contribute to the cause and development of these enigmatic diseases have not been fully elucidated yet.

The Known, the Unknown and the Future of the Pathophysiology of Endometriosis

Endometriosis is one of the most common causes of chronic pelvic pain and infertility, affecting 10% of women of reproductive age. A delay of up to 9 years is estimated between the onset of symptoms and the diagnosis of endometriosis. Endometriosis is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in research on endometriosis have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". There are several theories on the etiology of the disease, but the origin of endometriosis remains unclear. This review addresses the role of microRNAs (miRNAs), which are naturally occurring post-transcriptional regulatory molecules, in endometriotic lesion development, the inflammatory environment within the peritoneal cavity, including the role that cytokines play during the development of the disease, and how animal models have helped in our understanding of the pathology of this enigmatic disease.

Nerve Bundle Density and Expression of NGF and IL-1β Are Intra-Individually Heterogenous in Subtypes of Endometriosis

Endometriosis is a gynecological disorder associated with local inflammation and neuroproliferation. Increased nerve bundle density has been attributed to increased expression of nerve growth factor (NGF) and interleukin-1β (IL-1β). Immunohistochemical analysis was carried out on 12 patients presenting with all three anatomic subtypes of endometriosis (deep, superficial peritoneal, endometrioma) at surgery, with at least two surgically excised subtypes available for analysis. Immunolocalization for nerve bundle density around endometriosis using protein gene product 9.5 (PGP9.5), as well as NGF and IL-1β histoscores in endometriosis epithelium/stroma, was performed to evaluate differences in scores between lesions and anatomic subtypes per patient. Intra-individual heterogeneity in scores across lesions was assessed using the coefficient of variation (CV). The degree of score variability between subtypes was evaluated using the percentage difference between mean scores from one subtype to another subtype for each marker. PGP9.5 nerve bundle density was heterogenous across multiple subtypes of endometriosis, ranging from 50.0% to 173.2%, where most patients (8/12) showed CV ≥ 100%. The percentage difference in scores showed that PGP9.5 nerve bundle density and NGF and IL-1β expression were heterogenous between anatomic subtypes within the same patient. Based on these observations of intra-individual heterogeneity, we conclude that markers of neuroproliferation in endometriosis should be stratified by anatomic subtype in future studies of clinical correlation.

Digestive system deep infiltrating endometriosis: What do we know

Digestive system infiltrating endometriosis (DSIE) is an uncommon form of endometriosis in the digestive system. DSIE often occurs in the intestines (especially the sigmoid rectum), liver, gallbladder and pancreas. Clinically, DSIE presents with the same symptoms as endometriosis, including cyclic pain, bleeding and infertility, in addition to specific biliary/intestinal obstruction and gastrointestinal bleeding. Compared to general endometriosis, DSIE has unique biological behaviour and pathophysiological mechanisms. Most DSIEs are deep invasive endometrioses, characterized by metastasis to the lymph nodes and lymphatic vessels, angiogenesis, peripheral nerve recruitment, fibrosis and invasion of surrounding tissues. DSIE-related peripheral angiogenesis is divided into three patterns: angiogenesis, vasculogenesis and inosculation. These patterns are regulated by interactions between multiple hypoxia-hormone cytokines. The nerve growth factors regulate the extensive neurofibril recruitment in DSIE lesions, which accounts for severe symptoms of deep pain. They are also associated with fibrosis and the aggressiveness of DSIE. Cyclic changes in DSIE lesions, recurrent inflammation and oxidative stress promote repeated tissue injury and repair (ReTIAR) mechanisms in the lesions, accelerating fibril formation and cancer-related mutations. Similar to malignant tumours, DSIE can also exhibit aggressiveness derived from collective cell migration mediated by E-cadherin and N-cadherin. This often makes DSIE misdiagnosed as a malignant tumour of the digestive system in clinical practice. In addition to surgery, novel treatments are urgently required to effectively eradicate this lesion.

Neuroproliferative dyspareunia in endometriosis and vestibulodynia

INTRODUCTION

Endometriosis is a common cause of deep dyspareunia, while provoked vestibulodynia is a common cause of superficial dyspareunia. The etiology of dyspareunia in both conditions is multifactorial and may include the role of local nerve growth (neurogenesis or neuroproliferation) that sensitizes pelvic structures and leads to pain with contact.

OBJECTIVES

To review the evidence for neuroproliferative dyspareunia in endometriosis and provoked vestibulodynia.

METHODS

Narrative review.

RESULTS

The pelvic peritoneum and vulvar vestibule receive somatic and autonomic innervation. Various markers have been utilized for nerve subtypes, including pan-neuronal markers and those specific for sensory and autonomic nerve fibers. The nerve growth factor family includes neurotrophic factors, such as nerve growth factor and brain-derived neurotrophic factor, and their receptors. Studies of endometriosis and provoked vestibulodynia have demonstrated the presence of nerve fibers around endometriosis epithelium/stroma in the pelvic peritoneum and within the vulvar vestibule. The number of nerve fibers is higher in these pain conditions as compared with control tissue. Nerve growth factor expression by endometriosis stroma and by immune cells in the vulvar vestibule may be involved in local neuroproliferation. Local inflammation is implicated in this neuroproliferation, with potential roles of interleukin 1β and mast cells in both conditions. Several studies have shown a correlation between nerve fibers around endometriosis and dyspareunia severity, but studies are lacking in provoked vestibulodynia. There are several possible clinical ramifications of neuroproliferative dyspareunia in endometriosis and provoked vestibulodynia, in terms of history, examination, biopsy, and surgical and medical treatment.

CONCLUSIONS

A neuroproliferative subtype of dyspareunia may be implicated in endometriosis and provoked vestibulodynia. Additional research is needed to validate this concept and to integrate it into clinical studies. Neuroproliferative pathways could serve as novel therapeutic targets for the treatment of dyspareunia in endometriosis and provoked vestibulodynia.

The Sphingosine 1-Phosphate Axis: an Emerging Therapeutic Opportunity for Endometriosis

Endometriosis is a common condition in women of reproductive age, but its current interventions are unsatisfactory. Recent research discovered a dysregulation of the sphingosine 1-phosphate (S1P) signaling pathway in endometriosis and showed a positive outcome by targeting it. The S1P axis participates in a series of fundamental pathophysiological processes. This narrative review is trying to expound the reported and putative (due to limited reports in this area for now) interactions between the S1P axis and endometriosis in those pathophysiological processes, to provide some perspectives for future research. In short, S1P signaling pathway is highly activated in the endometriotic lesion. The S1P concentration has a surge in the endometriotic cyst fluid and the peritoneal fluid, with the downstream dysregulation of its receptors. The S1P axis plays an essential role in the migration and activation of the immune cells, fibrosis, angiogenesis, pain-related hyperalgesia, and innervation. S1P receptor (S1PR) modulators showed an impressive therapeutic effect by targeting the different S1P receptors in the endometriosis model, and many other conditions resemble endometriosis. And several of them already got approval for clinical application in many diseases, which means a drug repurposing direction and a rapid clinical translation for endometriosis treatments.

Estetrol Increases Progesterone Genetic Response without Triggering Common Estrogenic Effects in Endometriotic Cell Lines and Primary Cultures

Estetrol (E4), a natural estrogen produced by the human fetal liver, is actively studied for menopause and breast cancer treatment. It has low side effects and preferential estrogen receptor alpha (ERα) affinity. There are no data about its effects on endometriosis, a common gynecological disease affecting 6-10% of cycling women, generating painful pelvic lesions and infertility. Current combined hormone treatment (progestins and estrogens) is safe and efficient; nevertheless, one-third of patients develop progesterone (P4) resistance and recurrence by reducing P4 receptors (PRs) levels. We aimed to compare E4 and 17β-estradiol (E2) effects using two human endometriotic cell lines (epithelial 11Z and stromal Hs832 cells) and primary cultures from endometriotic patients. We evaluated cell growth (MTS), migration (wound assay), hormone receptors levels (Western blot), and P4 response by PCR array. Compared to E2, E4 did not affect cell growth or migration but increased estrogen receptor alpha (ERα) and PRs, and reduced ERβ. Finally, the incubation with E4 improved the P4 gene response. In conclusion, E4 increased PRs levels and genetic response without inducing cell growth or migration. These results suggest that E4 might be useful for endometriosis treatment avoiding P4 resistance; however, evaluating its response in more complex models is required.

Emerging Drug Targets for Endometriosis

Endometriosis is a chronic inflammatory disease causing distressing symptoms and requiring a life-long management strategy. The objective of this review is to evaluate endometriosis-related pathways and identify novel therapies to treat it. We focused on the crucial role of inflammation and inflammatory molecules in order to define new perspectives for non-hormonal treatment of the disease by targeting inflammation, nuclear factor kappa B and cytokines, or reactive oxygen species, apoptotic and autophagic pathways, regulators of epithelial-mesenchymal transition, and angiogenesis and neuroangiogenesis. Novel non-steroidal therapies targeting these pathways for endometriosis were explored, but multiple challenges remain. While numerous agents have been investigated in preclinical trials, few have reached the clinical testing stage because of use of inappropriate animal models, with no proper study design or reporting of preclinical strategies. Targeting estrogens is still the best way to control endometriosis progression and inflammation.

T-Cadherin, E-Cadherin, PR-A, and ER-α Levels in Deep Infiltrating Endometriosis

The goal of this study was to compare the T-cadherin, E-cadherin, progesterone receptor (PR), and estrogen receptor (ER) staining levels of deep infiltrating endometriosis (DIE) tissue, ovarian endometriomas and normal endometrial tissues in the same individuals. The tissue sections of both DIE nodule(s) and endometrioma(s) of 15 cases were examined. As a control group, normal endometrial tissue sections of 23 cases were examined. T-cadherin, E-cadherin, ER-α, and PR-A staining levels of DIE, endometrioma tissues, and endometrial tissues were compared immunohistochemically. H -score was calculated to compare the expression of T-cadherin, E-cadherin, ER-α, and PR-A in immunohistochemical staining based on the percentage of cells stained at each intensity level. T-cadherin, E-cadherin, ER, and PR H -score were lowest in DIE tissue and highest in endometrial tissue ( P <0.0001, <0.0001, <0.0001, and <0.0001, respectively). In correlation analysis, a positive correlation was found between T-cadherin, E-cadherin, PR, and ER H -score ( P <0.0001 for each). T-cadherin, E-cadherin, ER, and PR H -score were lowest in DIE tissue and highest in endometrium tissue. We think that examination of DIE tissue and endometrioma tissue from the same individual excludes the possibility of an effect due to different genetic and environmental factors from different individuals. With the help of this exclusion we showed that DIE and endometrioma have different biological properties.

Elevated latent transforming growth factor beta binding protein 2 in endometriosis promotes endometrial stromal cell invasion and proliferation via the NF-kB signaling pathway

Endometriosis, defined as the abnormal growth of functional endometrium outside the uterus, is characterized by the abnormal phenotype of endometrial cells. This study aimed to investigate the role of latent transforming growth factor beta binding protein 2 (LTBP2), an extracellular matrix protein, in the occurrence and development of endometriosis. Elevated LTBP2 expression levels were observed in endometrial tissues and serum of endometriosis patients and their area under the ROC curve (AUC) values for distinguishing endometriosis were 0.9044 and 0.9534, respectively. Overexpressing-LTBP2 could promote proliferation, migration, and invasion, whereas suppressing apoptosis of endometrial stromal cells (ESCs). Moreover, LTBP2 downregulation induced the opposite effect. The supernatant from ESCs overexpressing LTBP2 promoted the tube formation of human umbilical vein endothelial cells (HUVECs), thus indicating an angiogenic effect. Furthermore, overexpression of LTBP2 facilitated the inflammation and might promote endometriosis progression through the NF-kB signaling pathway. Conclusively, LTBP2 might be a potential target in the diagnosis and treatment of endometriosis.

Diagnostic gene biomarkers for predicting immune infiltration in endometriosis

Objective

To determine the potential diagnostic markers and extent of immune cell infiltration in endometriosis (EMS).

Methods

Two published profiles (GSE7305 and GSE25628 datasets) were downloaded, and the candidate biomarkers were identified by support vector machine recursive feature elimination analysis and a Lasso regression model. The diagnostic value and expression levels of biomarkers in EMS were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting, then further validated in the GSE5108 dataset. CIBERSORT was used to estimate the composition pattern of immune cell components in EMS.

Results

One hundred and fifty-three differential expression genes (DEGs) were identified between EMS and endometrial with 83 upregulated and 51 downregulated genes. Gene sets related to arachidonic acid metabolism, cytokine–cytokine receptor interactions, complement and coagulation cascades, chemokine signaling pathways, and systemic lupus erythematosus were differentially activated in EMS compared with endometrial samples. Aquaporin 1 (AQP1) and ZW10 binding protein (ZWINT) were identified as diagnostic markers of EMS, which were verified using qRT-PCR and western blotting and validated in the GSE5108 dataset. Immune cell infiltrate analysis showed that AQP1 and ZWINT were correlated with M2 macrophages, NK cells, activated dendritic cells, T follicular helper cells, regulatory T cells, memory B cells, activated mast cells, and plasma cells.

Conclusion

AQP1 and ZWINT could be regarded as diagnostic markers of EMS and may provide a new direction for the study of EMS pathogenesis in the future.

The deep infiltrating endometriosis tissue has lower T-cadherin, E-cadherin, progesterone receptor and oestrogen receptor than endometrioma tissue

OBJECTIVE

To compare the T-cadherin, E-cadherin, PR and ER staining levels of deep infiltrating endometriosis (DIE) tissue, ovarian endometriomas and normal endometrial tissues.

MATERIALS AND METHODS

DIE tissue of 24 cases, endometrioma of 30 cases and normal endometrial tissues of 30 cases were examined. T-cadherin, E-cadherin, ER-α and PR-α staining levels of DIE, endometrioma tissues and endometrial tissues were compared immunohistochemically. H-score was calculated to compare the expression of T-cadherin, E-cadherin, ER-α, PR-α in IHC staining based on the percentage of cells stained at each intensity level.

RESULTS

T-cadherin, E-cadherin, ER and PR H-score were found lowest in DIE tissue and the highest in endometrial tissue (p < 0.0001, <0.0001, <0.0001 and < 0.0001, respectively). In correlation analysis, a positive correlation was found between T-cadherin, E-cadherin, PR and ER H-score (p < 0.0001 for each). No correlation was found between age, body mass index (BMI), visual analog scale (VAS) score, CA125, endometrioma size and the severity of dysmenorrhea, dyspareunia and dystonia (p > 0.05).

CONCLUSION

T-cadherin, E-cadherin, ER and PR H-score were found lowest in DIE tissue, the highest in endometrium tissue. The finding of lower expression of PR-α in endometriotic nodule in our study may be related to decrease in progesterone effect which could not inhibit the decrease in the expression of T-cadherin and E-cadherin, thus the invasiveness of DIE tissue. These findings suggest that DIE tissue and ovarian endometrioma tissues have a different biology.

Conservative Management of Rectovaginal Deep Endometriosis: Shaving Should Be Considered as the Primary Surgical Approach in a High Majority of Cases

Deep endometriosis infiltrating the rectum remains a challenging situation to manage, and it is even more important when ureters and pelvic nerves are also infiltrated. Removal of deep rectovaginal endometriosis is mandatory in case of symptoms strongly impairing quality of life, alteration of digestive, urinary, sexual and reproductive functions, or in case of growing. Extensive preoperative imaging is required to choose the right technique between laparoscopic shaving, disc excision, or rectal resection. When performed by skilled surgeons and well-trained teams, a very high majority of cases of deep endometriosis nodule (>95%) is feasible by the shaving technique, and this is associated with lower complication rates regarding rectal resection. In most cases, removing a part of the rectum is questionable according to the risk of complications, and the rectum should be preserved as far as possible. Shaving and rectal resection are comparable in terms of recurrence rates. As shaving is manageable whatever the size of the lesions, surgeons should consider rectal shaving as first-line surgery to remove rectal deep endometriosis. Rectal stenosis of more than 80% of the lumen, multiple bowel deep endometriosis nodules, and stenotic sigmoid colon lesions should be considered as indication for rectal resection, but this represents a minority of cases.

Pathogenesis of Endometriosis: New Insights into Prospective Therapies

Endometriosis is a female reproductive disorder characterized by growth of uterine cells and tissue in distant sites. Around 2-10% of women experience this condition during reproductive age, 35-50% of whom encounter fertility issues or pain. To date, there are no established methods for its early diagnosis and treatment, other than surgical procedures and scans. It is difficult to identify the disease at its onset, unless symptoms such as infertility and/or pain are present. Determining the mechanisms involved in its pathogenesis is vital, not only to pave the way for early identification, but also for disease management and development of less invasive but successful treatment strategies. Endometriosis is characterized by cell proliferation, propagation, evasion of immunosurveillance, and invasive metastasis. This review reports the underlying mechanisms that are individually or collectively responsible for disease establishment and evolution. Treatment of endometriosis mainly involves hormone therapies, which may be undesirable or have their own repercussions. It is therefore important to devise alternative strategies that are both effective and cause fewer side effects. Use of phytochemicals may be one of them. This review focuses on pharmacological inhibitors that can be therapeutically investigated in terms of their effects on signaling pathways and/or mechanisms involved in the pathogenesis of endometriosis.

GnRH Antagonists with or without Add-Back Therapy: A New Alternative in the Management of Endometriosis?

To evaluate the effectiveness of a new class of medical drugs, namely oral gonadotropin-releasing hormone (GnRH) antagonists, in the management of premenopausal women with endometriosis-associated pelvic pain. We reviewed the most relevant papers (n = 27) on the efficacy of new medical alternatives (oral GnRH antagonists) as therapy for endometriosis. We first briefly summarized the concept of progesterone resistance and established that oral contraceptives and progestogens work well in two-thirds of women suffering from endometriosis. Since clinical evidence shows that estrogens play a critical role in the pathogenesis of the disease, lowering their levels with oral GnRH antagonists may well prove effective, especially in women who fail to respond to progestogens. There is a need for reliable long-term oral treatment capable of managing endometriosis symptoms, taking into consideration both the main symptoms and phenotype of the disease. Published studies reviewed and discussed here confirm the efficacy of GnRH antagonists. There is a place for GnRH antagonists in the management of symptomatic endometriosis. Novel algorithms that take into account the different phenotypes are proposed.

Identifying Common Pathogenic Features in Deep Endometriotic Nodules and Uterine Adenomyosis

Increasing imaging data point to a link between deep endometriotic nodules (DENs) and uterine adenomyosis (AD). The study aimed to investigate this link at the histological level and detect potential features shared by the two diseases. We collected formalin-fixed paraffin-embedded tissue (endometrium and lesions) from women with DENs of the rectovaginal septum (n = 13), AD (n = 14), and control subjects (n = 14). Immunohistochemical analyses of CD41 and CD68 were conducted to explore the roles of platelets and macrophages, respectively. Picrosirius red staining was carried out to gather evidence of fibrosis. Vascular endothelial growth factor (VEGF) was assessed, and total numbers of CD31-positive vessels were calculated to investigate the mechanism governing angiogenesis. Double immunohistochemistry for CD31 and alpha smooth muscle actin (αSMA) was performed to discern stable vessels. Platelet aggregation was significantly decreased in both types of lesions compared to their corresponding eutopic endometrium and healthy controls. Macrophage numbers were higher in both lesions than in their corresponding endometrium and healthy subjects. Significantly higher rates of collagen accumulation were detected in DENs and AD lesions compared to their corresponding eutopic and healthy endometrium. VEGF expression was downregulated in the stromal compartment of AD lesions compared to the healthy endometrium. The total number of vessels per area was significantly higher in DENs and AD lesions than in the healthy endometrium. Rates of αSMA-surrounded vessels were decreased in DENs and AD lesions compared to their corresponding eutopic and healthy endometrium. We report common pathogenic mechanisms between DENs and AD, namely excessive macrophage accumulation, fibrosis, and irregular angiogenesis. Our results further support the notion of DENs and AD being linked at the histological level.

Intestinal endometriotic nodules with a length greater than 2.25 cm and affecting more than 27% of the circumference are more likely to undergo segmental resection, rather than linear nodulectomy

Study objective

To analyze the efficacy of intestinal ultrasonography with bowel preparation (TVUSBP) for endometriosis mapping in evaluating intestinal endometriosis to choose the surgical technique (segmental resection or linear nodulectomy) for treatment.

Design

Cross-sectional observational study.

Setting

University Hospital—Center for Advanced Endoscopic Gynecologic Surgery from April 2010 to November 2014.

Patient(s)

One hundred and eleven women with clinically suspected endometriosis and intestinal endometriotic nodule or intestinal adherence in TVUSBP for endometriosis mapping.

Intervention(s)

All patients with suspected endometriosis underwent TVUSBP for endometriosis mapping prior to videolaparoscopy for complete excision of endometriosis foci, including intestinal foci, using the linear nodulectomy or segmental resection techniques, depending on the characteristics of the intestinal lesion with confirmation of endometriosis on anatomopathological examination.

Measurements and main results

Preoperative ultrasonographic assessment of the length of the intestinal nodule, circumference of the intestinal loop affected by the endometriotic lesion, distance from the anal verge and intestinal wall layers infiltrated by endometriosis, as well as other endometriosis sites. Of the 111 patients who participated in the study, 63 (56.7%) presented intestinal endometriotic nodules in ultrasonography, performed by a single examiner (A.L.A.N.), and underwent intestinal surgical treatment of deep endometriosis—linear nodulectomy or segmental resection. The analysis of the receiver operating characteristic (ROC) curve showed that a longitudinal length of the intestinal nodule of 2.25 cm and a loop circumference of 27% are cutoff points separating linear nodulectomy from segmental resection techniques for excising intestinal endometriosis. The information obtained by TVUSBP helps the surgeon and patient, in the preoperative period, to select the surgical technique to be performed for resection of intestinal endometriosis and plan the surgical procedure while taking into account postoperative morbidity.

Collagen I triggers directional migration, invasion and matrix remodeling of stroma cells in a 3D spheroid model of endometriosis

Endometriosis is a painful gynecological condition characterized by ectopic growth of endometrial cells. Little is known about its pathogenesis, which is partially due to a lack of suitable experimental models. Here, we use endometrial stromal (St-T1b), primary endometriotic stromal, epithelial endometriotic (12Z) and co-culture (1:1 St-T1b:12Z) spheroids to mimic the architecture of endometrium, and either collagen I or Matrigel to model ectopic locations. Stromal spheroids, but not single cells, assumed coordinated directional migration followed by matrix remodeling of collagen I on day 5 or 7, resembling ectopic lesions. While generally a higher area fold increase of spheroids occurred on collagen I compared to Matrigel, directional migration was not observed in co-culture or in 12Z cells. The fold increase in area on collagen I was significantly reduced by MMP inhibition in stromal but not 12Z cells. Inhibiting ROCK signalling responsible for actomyosin contraction increased the fold increase of area and metabolic activity compared to untreated controls on Matrigel. The number of protrusions emanating from 12Z spheroids on Matrigel was decreased by microRNA miR-200b and increased by miR-145. This study demonstrates that spheroid assay is a promising pre-clinical tool that can be used to evaluate small molecule drugs and microRNA-based therapeutics for endometriosis.

The selective PGI2 receptor agonist selexipag ameliorates Sugen 5416/hypoxia-induced pulmonary arterial hypertension in rats

Pulmonary arterial hypertension (PAH) is a lethal disease characterized by a progressive increase in pulmonary artery pressure due to an increase in vessel tone and occlusion of vessels. The endogenous vasodilator prostacyclin and its analogs are used as therapeutic agents for PAH. However, their pharmacological effects on occlusive vascular remodeling have not been elucidated yet. Selexipag is a recently approved, orally available and selective prostacyclin receptor agonist with a non-prostanoid structure. In this study, we investigated the pharmacological effects of selexipag on the pathology of chronic severe PAH in Sprague-Dawley and Fischer rat models in which PAH was induced by a combination of injection with the vascular endothelial growth factor receptor antagonist Sugen 5416 and exposure to hypoxia (SuHx). Oral administration of selexipag for three weeks significantly improved right ventricular systolic pressure and right ventricular (RV) hypertrophy in Sprague-Dawley SuHx rats. Selexipag attenuated the proportion of lung vessels with occlusive lesions and the medial wall thickness of lung arteries, corresponding to decreased numbers of Ki-67-positive cells and a reduced expression of collagen type 1 in remodeled vessels. Administration of selexipag to Fischer rats with SuHx-induced PAH reduced RV hypertrophy and mortality caused by RV failure. These effects were probably based on the potent prostacyclin receptor agonistic effect of selexipag on pulmonary vessels. Selexipag has been approved and is used in the clinical treatment of PAH worldwide. It is thought that these beneficial effects of prostacyclin receptor agonists on multiple aspects of PAH pathology contribute to the clinical outcomes in patients with PAH.

Progression of deep infiltrating rectosigmoid endometriotic nodules

STUDY QUESTION

What is the risk of progression of deep endometriotic nodules infiltrating the rectosigmoid?

SUMMARY ANSWER

There is a risk of progression of deep endometriotic nodules infiltrating the rectosigmoid, particularly in menstruating women.

WHAT IS KNOWN ALREADY

Currently, there is a lack of acceptance in the literature on the probability that deeply infiltrating rectosigmoid endometriotic nodules progress in size.

STUDY DESIGN, SIZE, DURATION

We conducted a monocentric case-control study between September 2016 and March 2018 at Rouen University Hospital. We enrolled 43 patients who were referred to our tertiary referral centre with deep endometriosis infiltrating the rectosigmoid, who had undergone two MRI examinations at least 12 months apart and had not undergone surgical treatment of rectosigmoid endometriosis during this interval.

PARTICIPANTS/MATERIALS, SETTING, METHODS

MRI images were reinterpreted by a senior radiologist with experience and expertise in endometriosis, who measured the length and thickness of deep infiltrating colorectal lesions. Intra- and inter-observer reliability were tested on 30 randomly selected cases. We defined 'progression' of a nodule as an increase of ≥20% in length or in thickness and 'regression' of a lesion as a decrease of ≥20% in length or in thickness between two MRIs. Any nodule for which the variation in length and thickness was <20% was considered as 'stable'. Patients were divided into three groups based on evidence of progression, regression or stability of deep endometriotic nodules between their two MRI examinations. The total length of any period of amenorrhoea between the two MRI examinations, due to pregnancy, breastfeeding or hormonal treatment, was recorded. The total proportion of the time between MRIs where amenorrhoea occurred was compared between groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Eighty-six patients underwent at least two MRIs for deep endometriosis infiltrating the sigmoid or rectum between September 2016 and March 2018. Of these, we excluded 10 patients with an interval of <12 months between MRIs, 10 patients who underwent surgery between MRIs, 17 patients for whom at least 1 MRI was considered to be of poor quality and 6 patients for whom no deep colorectal lesion was found on repeat review of either MRI. This resulted in a total of 43 patients eligible for enrolment in the final analysis. Mean time (SD) between MRIs was 38.3 (22.1) months. About 60.5% of patients demonstrated stability of their colorectal lesions between the two MRIs, 27.9% of patients met the criteria for 'progression' of lesions and 11.6% met the criteria for 'regression' of lesions. There was no significant difference in time interval between MRIs for the three groups (P = 0.76). Median duration of amenorrhoea was significantly lower in women with progression of lesions (7.5 months) when compared to those with stability of lesions (8.5 months) or regression of lesions (21 months) (P < 0.001). Median duration of amenorrhoea (expressed as percentage of total time between two MRIs) was also found to be significantly lower in the group demonstrating progression (15.1%) when compared to the group demonstrating stability (19.2%) and the group demonstrating regression (94.1%; P = 0.006). Progression of rectosigmoid nodules was observed in 34% of patients without continuous amenorrhoea, in 39% who had never had amenorrhoea and in no patients with continuous amenorrhoea.

LIMITATIONS, REASONS FOR CAUTION

Due to a lack of universally accepted criteria for defining the progression or regression of deep endometriotic nodules on MRI, the values used in our study may be disputed. Due to the retrospective design of the study, there may be heterogeneity of interval between MRIs, MRI techniques used, reason for amenorrhoea and duration of amenorrhoea. The mean inter-MRI interval was of short duration and varied between patients. Our findings are reported for only deep endometriosis infiltrating the rectosigmoid and cannot be extrapolated, without caution, to nodules of other locations.

WIDER IMPLICATIONS OF THE FINDINGS

Patients with deeply infiltrating rectosigmoid endometriotic nodules, for which surgical management has not been performed, should undergo surveillance to allow detection of growth of nodules, particularly when continuous amenorrhoea has not been achieved. This recommendation is of importance to young patients with rectosigmoid nodules who wish to conceive, in whom first line ART is planned. There is a very low risk of progression of deep endometriotic nodules infiltrating the rectosigmoid in women with amenorrhoea induced by medical therapy, lactation or pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. The authors declare no competing interests related to this study.

miR-142-3p Reduces the Size, Migration, and Contractility of Endometrial and Endometriotic Stromal Cells by Targeting Integrin- and Rho GTPase-Related Pathways That Regulate Cytoskeletal Function

Downregulated microRNA-142-3p signaling contributes to the pathogenesis of endometriosis, an invasive disease where the lining of the uterus grows at ectopic locations, by yet incompletely understood mechanisms. Using bioinformatics and in vitro assays, this study identifies cytoskeletal regulation and integrin signaling as two relevant categories of miR-142-3p targets. qPCR revealed that miR-142-3p upregulation in St-T1b cells downregulates Rho-associated protein kinase 2 (ROCK2), cofilin 2 (CFL2), Ras-related C3 botulinum toxin substrate 1 (RAC1), neural Wiskott-Aldrich syndrome protein (WASL), and integrin α-V (ITGAV). qPCR and Western-blotting showed miR-142-3p effect on WASL and ITGAV was significant also in primary endometriotic stroma cells. Luciferase reporter assays in ST-T1b cells then confirmed direct regulation of ITGAV and WASL. On the functional side, miR-142-3p upregulation significantly reduced ST-T1b cell size, the size of vinculin plaques, migration through fibronectin-coated transwell filters, and the ability of ST-T1b and primary endometriotic stroma cells to contract collagen I gels. These results suggest that miR-142-3p has a strong mechanoregulatory effect on endometrial stroma cells and its external administration reduces the invasive endometrial phenotype. Within the limits of an in vitro investigation, our study provides new mechanistic insights into the pathogenesis of endometriosis and provides a perspective for the development of miR-142-3p based drugs for inhibiting invasive growth of endometriotic cells.

Deep endometriosis: The place of laparoscopic shaving

Deep endometriosis (DE) is considered to be one of the most challenging conditions to manage, especially when it invades surrounding organs like the rectum. Surgical excision of deep rectovaginal endometriosis is required when lesions are symptomatic, impairing bowel, urinary, sexual, and reproductive functions, or if they evolve. Preoperative radiological examination should be extensive to determine the appropriate surgery: laparoscopic shaving, disc excision, or rectal resection. We demonstrated that in the hands of experienced surgeons, rectal shaving is possible for DE in more than 95% of cases, with low complication rates compared to rectal resection. Shaving and bowel resection are associated with comparable recurrence rates. As shaving is indicated whatever the size of deep lesions, surgeons should first consider rectal shaving to remove DE. Bowel resection should only be performed in case of major rectal stenosis (>80%), multiple and/or posterior rectal lesions and stenotic sigmoid colon lesions.

Autonomic nervous system and inflammation interaction in endometriosis-associated pain

Endometriosis is a chronic inflammatory disease. Pain is the most common symptom in endometriosis. Endometriosis-associated pain is caused by inflammation, and is related to aberrant innervation. Although the specific mechanism between endometriosis-associated pain and the interaction of aberrant innervation and inflammation remains unclear, many studies have confirmed certain correlations between them. In addition, we found that some chronic inflammatory autoimmune diseases (AIDs) such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) share similar characteristics: the changes in dysregulation of inflammatory factors as well as the function and innervation of the autonomic nervous system (ANS). The mechanisms underlying the interaction between the ANS and inflammation have provided new advances among these disorders. Therefore, the purpose of this review is to compare the changes in inflammation and ANS in endometriosis, IBD, and RA; and to explore the role and possible mechanism of sympathetic and parasympathetic nerves in endometriosis-associated inflammation by referring to IBD and RA studies to provide some reference for further endometriosis research and treatment.

Relationship between Patient Age and Disease Features in a Prospective Cohort of 1560 Women Affected by Endometriosis

OBJECTIVE

To assess the relationship between age, location of the disease, and surgical procedures performed in patients undergoing surgical management of endometriosis.

DESIGN

Retrospective study using data prospectively recorded in the North-West Inter Regional Female Cohort for Patients with Endometriosis database.

SETTING

University tertiary referral center.

PATIENTS

Women who underwent surgical management of symptomatic endometriosis between April 2009 and April 2014.

INTERVENTIONS

Patients were allocated to 6 groups according to their age at the time of surgery: ≤20, 21 to 25, 26 to 30, 31 to 35, 36 to 40 and >40 years. Patient characteristics, prior history, location of endometriotic lesions, stage of disease, intraoperative findings, and surgical procedures were retrieved from a prospectively recorded database.

MEASUREMENTS AND MAIN RESULTS

Patient characteristics, symptoms, location of endometriosis, and type of surgery performed were compared between groups. In total, 1560 procedures were performed. Of these, more than one-half were carried out in women between the age of 26 to 35 years and the majority were performed in women aged between 26 and 30 years. Only 2% of procedures were performed in women under the age of 20 years. The mean stage of the disease at the time of surgical diagnosis was stage II for women younger than 20 years, stage III for those in the age group of 21 to 25 years, and stage IV for those older than 26 years. The rate of diagnosis of deep colorectal nodules increased progressively from 20 to 26 years and remained stable thereafter.

CONCLUSION

Our data confirm that endometriosis is a disease that probably progresses from adolescence until the adult period when symptoms (pain or infertility) become debilitating and require surgery. Our data suggest that policies relating to the prevention and early diagnosis of endometriosis should focus on women younger than 25 years.

Invasion of human deep nodular endometriotic lesions is associated with collective cell migration and nerve development

OBJECTIVE

To study the mechanisms of invasion and innervation of deep endometriosis in women.

DESIGN

Morphologic and immunohistochemical analysis of human endometriotic lesions.

SETTING

Academic research unit.

PATIENT(S)

Seventeen biopsy samples of deep endometriotic lesions were collected from patients undergoing surgery for deep endometriosis.

INTERVENTION(S)

The endometriotic samples were divided into two parts: the front (the most invasive area of lesions, approaching rectal infiltration) and center (the area close to the posterior part of the cervix).

MAIN OUTCOME(S)

To elucidate: gland morphology, proliferation, and expression of adhesion molecules (β-catenin, E-cadherin, and N-cadherin) to determine the possible role of collective cell migration (CCM) in the invasion process; and nerve growth factor (NGF) and nerve fiber density (NFD) values to shed further light on the mechanism of innervation.

RESULTS

Glands from the front showed significantly reduced thickness, but significantly higher proliferation. β-Catenin expression was similar between the lesion center and front. E-cadherin levels were significantly lower and N-cadherin levels significantly higher in glands located at the front of the lesions. Expression of matrix metalloproteinase-9 was significantly higher in glands and stromal cells located at the invasion front. NFD and NGF expression were also significantly higher at the lesion front.

CONCLUSION

Although some data in the literature point to features of epithelial to mesenchymal transition in human deep nodular endometriosis, our study suggests that gland invasion in these lesions is dominated by CCM. Innervation of deep nodular endometriotic lesions may be a consequence of nerve recruitment from surrounding organs.

Pathogenesis of endometriosis: the genetic/epigenetic theory

OBJECTIVE

To study the pathophysiology of endometriosis.

DESIGN

Overview of observations on endometriosis.

SETTING

Not applicable.

PATIENT(S)

None.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The hypothesis is compatible with all observations.

RESULT(S)

Endometriosis, endometrium-like tissue outside the uterus, has a variable macroscopic appearance and a poorly understood natural history. It is a hereditary and heterogeneous disease with many biochemical changes in the lesions, which are clonal in origin. It is associated with pain, infertility, adenomyosis, and changes in the junctional zone, placentation, immunology, plasma, peritoneal fluid, and chronic inflammation of the peritoneal cavity. The Sampson hypothesis of implanted endometrial cells following retrograde menstruation, angiogenic spread, lymphogenic spread, or the metaplasia theory cannot explain all observations if metaplasia is defined as cells with reversible changes and an abnormal behavior/morphology due to the abnormal environment. We propose a polygenetic/polyepigenetic mechanism. The set of genetic and epigenetic incidents transmitted at birth could explain the hereditary aspects, the predisposition, and the endometriosis-associated changes in the endometrium, immunology, and placentation. To develop typical, cystic ovarian or deep endometriosis lesions, a variable series of additional transmissible genetic and epigenetic incidents are required to occur in a cell which may vary from endometrial to stem cells. Subtle lesions are viewed as endometrium in a different environment until additional incidents occur. Typical cystic ovarian or deep endometriosis lesions are heterogeneous and represent three different diseases.

CONCLUSION(S)

The genetic epigenetic theory is compatible with all observations on endometriosis. Implications for treatment and prevention are discussed.

Pelvic organ cross-talk: A new paradigm for endometriosis-related pelvic pain?

Endometriosis patients often complain about pelvic and abdominal pain with varying bowel and bladder symptoms unrelated to the location and extent of the disease. The pathophysiology can be multifactorial, but one possibility is that pelvic organ cross-talk may play a role. The aim of this review was to evaluate the scientific support for this hypothesis. A search was performed in PubMed to identify relevant experimental and clinical studies. Data achieved in animal models and clinical evidence suggest that endometriosis-related pain may implicate interactions between pelvic structures like the urinary tract, the bowel and the vagina, mediated by the autonomous nervous system. Such pelvic organ cross-talk with involvement of nerve fibre outgrowth into endometriosis lesions, peripheral sensitisation and convergence of afferent nerve fibres could be an explanation for the varying pain problems in endometriosis, but the precise mechanisms are still poorly understood. Some patients with chronic pelvic pain, including those with endometriosis, also seem to have a more general somatic, musculoskeletal hyperalgesia, indicating a potential viscero-somatic convergence. This might be due to continuous nociceptive input to the brain, resulting in changes in brain structures and finally leading to central sensitisation. Thus, pelvic organ cross-talk seems to represent a new paradigm for endometriosis-related pain with novel possibilities for the development of therapeutic strategies.

Choosing the right surgical technique for deep endometriosis: shaving, disc excision, or bowel resection?

Deep endometriosis (DE) remains the most difficult endometriotic entity to treat. Medical treatment for DE can reduce symptoms but does not cure the disease, and surgical removal of the lesion is required when lesions are symptomatic, impairing bowel, urinary, sexual, and reproductive functions. Although several surgical techniques such as laparoscopic bowel resection, disc excision, and rectal shaving have been described, there is no consensus regarding the choice of technique or the timing of surgery. Our review of publications reporting results and complications of surgery for rectovaginal DE reveals a relatively higher complication rate after bowel resection compared with shaving and disc excision, especially for rectovaginal fistulas, anastomotic leakage, delayed hemorrhage, and long-term bladder catheterization. Data show that shaving is feasible even in advanced disease. The risk of immediate complications after shaving and disc excision is probably lower than after colorectal resection, allowing for better functional outcomes. The presumed higher risk of recurrence related to shaving has not been demonstrated. For these reasons, surgeons should consider rectal shaving as a first-line surgical treatment of rectovaginal DE, regardless of nodule size or association with other digestive localizations. When the result of rectal shaving is unsatisfactory (rare cases), disc excision may be performed either exclusively by laparoscopy or by using transanal staplers. Segmental resection may ultimately be reserved for advanced lesions responsible for major stenosis or for several cases of multiple nodules infiltrating the rectosigmoid junction or sigmoid colon.