Adhesion of endometrial cells labeled with 111Indium-tropolonate to peritoneum: a novel in vitro model to study endometriosis

Research advances in endometriosis-related signaling pathways: A review

Endometriosis (EM) is characterized by the existence of endometrial mucosa outside the uterine cavity, which causesinfertility, persistent aches, and a decline in women's quality of life. Both hormone therapies and nonhormone therapies, such as NSAIDs, are ineffective, generic categories of EM drugs. Endometriosis is a benign gynecological condition, yet it shares a number of features with cancer cells, including immune evasion, survival, adhesion, invasion, and angiogenesis. Several endometriosis-related signaling pathways are comprehensively reviewed in this article, including E2, NF-κB, MAPK, ERK, PI3K/Akt/mTOR, YAP, Wnt/β-catenin, Rho/ROCK, TGF-β, VEGF, NO, iron, cytokines and chemokines. To find and develop novel medications for the treatment of EM, it is essential to implicitly determine the molecular pathways that are disordered during EM development. Additionally, research on the shared pathways between EM and tumors can provide hypotheses or suggestions for endometriosis therapeutic targets.

Effect of early inflammatory reaction on ovarian reserve after laparoscopic cystectomy for ovarian endometriomas

This study aimed to investigate the effect of early inflammatory reaction on ovarian reserve of patients with ovarian endometriomas after laparoscopic cystectomy. Our retrospective case series included 112 patients with ovarian endometriomas that underwent the laparoendoscopic single-site cystectomy. Interleukin-6 (IL-6), hs-CRP, tumour necrosis factor-α (TNF-α), interleukin-17A (IL-17A) and AMH level were detected during perioperative and postoperative period. In our study, ovarian endometriomas with low AMH group were found having higher level of IL-6 than the normal AMH group in the preoperative status. On the 3rd day after operation, the change of AMH level was inversely proportional to the IL-6 level. During the follow-up within one year, it was found that the bilateral nature of the cyst and the postoperative IL-6 increased level were the risk factors for AMH not returning to baseline level. Our results suggested that inflammatory reaction is indeed involved in the damage of ovarian reserve during laparoscopic cystectomy. Hence, the negative impact of inflammatory injury should be fully considered before operation, especially young women with bilateral ovarian endometriomas.Impact StatementWhat is already known on this subject? Ovarian reserve in women always was reduced after the laparoscopic cystectomy. It is reported that it may be related to the use of energy instruments, haemostatic methods or the size of cysts in minimally invasive surgery.What do the results of this study add? Inflammatory reaction is indeed involved in the damage of ovarian reserve during LESS cystectomy. Interleukin-6 (IL-6) may act as the most main inflammatory factor aggravating damage of the ovarian reserve. Moreover, increased IL-6 level after surgery and bilateral cyst burden are the two risk factors for AMH not returning to baseline level within one year after surgery.What are the implications of these findings for clinical practice and/or further research? In clinic, the negative impact of inflammatory injury on ovarian reserve should be fully considered before operation, especially young women with bilateral ovarian endometriomas. Moreover, this is also the clinical basis for further study on the mechanism of inflammatory ovarian injury or the method of blocking the inflammatory response to reduce the damage of ovarian reserve after surgery.

Efficacy of niclosamide on the intra-abdominal inflammatory environment in endometriosis

Endometriosis, a common gynecological disease, causes chronic pelvic pain and infertility in women of reproductive age. Due to the limited efficacy of current therapies, a critical need exists to develop new treatments for endometriosis. Inflammatory dysfunction, instigated by abnormal macrophage (MΦ) function, contributes to disease development and progression. However, the fundamental role of the heterogeneous population of peritoneal MΦ and their potential druggable functions is uncertain. Here we report that GATA6-expressing large peritoneal MΦ (LPM) were increased in the peritoneal cavity following lesion induction. This was associated with increased cytokine and chemokine secretion in the peritoneal fluid (PF), as well as MΦ infiltration, vascularization and innervation in endometriosis-like lesions (ELL). Niclosamide, an FDA-approved anti-helminthic drug, was effective in reducing LPM number, but not small peritoneal MΦ (SPM), in the PF. Niclosamide also inhibits aberrant inflammation in the PF, ELL, pelvic organs (uterus and vagina) and dorsal root ganglion (DRG), as well as MΦ infiltration, vascularization and innervation in the ELL. PF from ELL mice stimulated DRG outgrowth in vitro, whereas the PF from niclosamide-treated ELL mice lacked the strong stimulatory nerve growth response. These results suggest LPM induce aberrant inflammation in endometriosis promoting lesion progression and establishment of the inflammatory environment that sensitizes peripheral nociceptors in the lesions and other pelvic organs, leading to increased hyperalgesia. Our findings provide the rationale for targeting LPM and their functions with niclosamide and its efficacy in endometriosis as a new non-hormonal therapy to reduce aberrant inflammation which may ultimately diminish associated pain.

Endometrioma, the follicular fluid inflammatory network and its association with oocyte and embryo characteristics

RESEARCH QUESTION

What is the association between endometrioma-affected ovaries, their follicular fluid inflammatory microenvironment, and ovary-specific oocyte and embryo yield and quality?

DESIGN

Exposure-matched prospective cohort study conducted at a university-affiliated infertility clinic. Thirty-four women presenting for oocyte retrieval were enrolled between 2012 and 2013: women with unilateral endometrioma and no other observed peritoneal or deep lesions (n = 10) and women with no signs or symptoms of endometriosis (n = 24). Follicular fluid was aspirated at the time of oocyte retrieval. Samples from each ovary were analysed using a 27-plex immunoassay panel. The associations were evaluated by ovary-specific endometrioma exposure status (affected, unaffected, unexposed) with cytokine levels, oocyte yield and embryo quality.

RESULTS

Levels of interleukin (IL)-8 and monocyte chemoattractant protein-1 were higher in fluid obtained from endometrioma-affected ovaries compared with the unexposed ovaries from women without endometriosis, with intermediate levels observed in the contralateral unaffected ovaries. More modest differences were observed for IL-1β and IL-6. The affected ovaries of women with endometriosis yielded fewer oocytes (mean ± SD = 4.6 ± 2.3) compared with both the unaffected (6.0 ± 3.8) and unexposed (7.9 ± 5.6) ovaries. After adjusting for potential confounders and variables generated in a cytokine principal components analysis, oocyte yield remained slightly lower for the endometrioma-affected ovaries compared with unexposed ovaries. No informative differences among ovary groups for embryo quality parameters were observed.

CONCLUSIONS

The results suggest that the inflammatory milieu of ovarian endometriosis is strongly localized and has a more modestly systemic effect. The effect of endometriomas on infertility, however, cannot be entirely explained by increased inflammation.

Iatrogenic parasitic myoma and iatrogenic adenomyoma after laparoscopic morcellation: A mini-review

Laparoscopy is widely recognized as a procedure of choice for gynaecological surgery. Myomectomy and hysterectomy are the most frequently performed surgical procedures in gynaecology. A morcellator is often used in myomectomies or subtotal hysterectomies, but morcellation may cause rare complications, such as parasitic iatrogenic myoma or adenomyoma. To improve patient counselling, proper risk estimation as well as risk factor identification should be acknowledged. This article aimed to review the literature on parasitic myoma and adenomyoma and to compare these diseases in terms of clinical, surgical, and prognostic factors. All published literature (case series and case reports) on iatrogenic myoma and adenomyoma was reviewed using PubMed/MEDLINE and ScienceDirect resources. Despite both conditions having an iatrogenic origin, iatrogenic parasitic myoma and adenomyoma are two different entities in terms of clinical manifestations as well as intraoperative particularities, with a common point: iatrogenic complication. A possible solution to avoid these iatrogenic complications is by using in-bag morcellation or switching to another surgical procedure (e.g., a vaginal or abdominal approach). It is concluded that parasitic myoma and iatrogenic adenomyoma are two different iatrogenic morcellator-related complications. In patients with a history of uterus or myoma morcellation who report pelvic symptoms, iatrogenic parasitic myoma or adenomyoma should be considered in the differential diagnosis.

Membrane Radiolabelling of Exosomes for Comparative Biodistribution Analysis in Immunocompetent and Immunodeficient Mice - A Novel and Universal Approach

Extracellular vesicles, in particular exosomes, have recently gained interest as novel drug delivery vectors due to their biological origin and inherent intercellular biomolecule delivery capability. An in-depth knowledge of their in vivo biodistribution is therefore essential. This work aimed to develop a novel, reliable and universal method to radiolabel exosomes to study their in vivo biodistribution.

Methods: Melanoma (B16F10) cells were cultured in bioreactor flasks to increase exosome yield. B16F10-derived exosomes (Exo_B16) were isolated using ultracentrifugation onto a single sucrose cushion, and were characterised for size, yield, purity, exosomal markers and morphology using nanoparticle tracking analysis (NTA), protein measurements, flow cytometry and electron microscopy. Exo_B16 were radiolabelled using 2 different approaches - intraluminal labelling (entrapment of ¹¹¹Indium via tropolone shuttling); and membrane labelling (chelation of ¹¹¹Indium via covalently attached bifunctional chelator DTPA-anhydride). Labelling efficiency and stability was assessed using gel filtration and thin layer chromatography. Melanoma-bearing immunocompetent (C57BL/6) and immunodeficient (NSG) mice were injected intravenously with radiolabelled Exo_B16 (1x10¹¹ particles/mouse) followed by metabolic cages study, whole body SPECT-CT imaging and ex vivo gamma counting at 1, 4 and 24 h post-injection.

Results: Membrane-labelled Exo_B16 showed superior radiolabelling efficiency and radiochemical stability (19.2 ± 4.53 % and 80.4 ± 1.6 % respectively) compared to the intraluminal-labelled exosomes (4.73 ± 0.39 % and 14.21 ± 2.76 % respectively). Using the membrane-labelling approach, the in vivo biodistribution of Exo_B16 in melanoma-bearing C57Bl/6 mice was carried out, and was found to accumulate primarily in the liver and spleen (~56% and ~38% ID/gT respectively), followed by the kidneys (~3% ID/gT). Exo_B16 showed minimal tumour i.e. self-tissue accumulation (~0.7% ID/gT). The membrane-labelling approach was also used to study Exo_B16 biodistribution in melanoma-bearing immunocompromised (NSG) mice, to compare with that in the immunocompetent C57Bl/6 mice. Similar biodistribution profile was observed in both C57BL/6 and NSG mice, where prominent accumulation was seen in liver and spleen, apart from the significantly lower tumour accumulation observed in the NSG mice (~0.3% ID/gT).

Conclusion: Membrane radiolabelling of exosomes is a reliable approach that allows for accurate live imaging and quantitative biodistribution studies to be performed on potentially all exosome types without engineering parent cells.

Adhesion in Physiological, Benign and Malignant Proliferative States of the Endometrium: Microenvironment and the Clinical Big Picture

Although the developments in cellular and molecular biology over the last few decades have significantly advanced our understanding of the processes and players that regulate invasive disease, many areas of uncertainty remain. This review will discuss the contribution of dysregulated cell⁻cell and cell⁻matrix adhesion to the invasion in both benign and malignant contexts. Using the endometrium as an illustrative tissue that undergoes clinically significant invasion in both contexts, the adhesion considerations in the cells ("seed") and their microenvironment ("soil") will be discussed. We hope to orientate this discussion towards translational relevance for the diagnosis and treatment of endometrial conditions, which are currently associated with significant morbidity and mortality.

Genetic Variation at Chromosome 2q13 and Its Potential Influence on Endometriosis Susceptibility Through Effects on the IL-1 Family

Endometriosis is characterized by the growth of epithelial and stromal cells outside the uterine cavity. It has a complex etiology and affects ∼10% of reproductive age women. It is accompanied by a chronic inflammatory response with substantial evidence to indicate genetic susceptibility. The causal genes and their pathways leading to endometriosis, however, are still unknown. Recently, genomewide association studies on endometriosis identified 14 genomic risk loci in women of European and Japanese ancestry. It is becoming increasingly clear that these risk regions are intergenic and thus contribute to disease susceptibility through regulatory mechanisms, most likely mediated through regulation of genes within a restricted distance from the risk variants. One endometriosis risk locus has been detected at chromosome 2q13 within an inflammatory-rich region of gene transcripts and thus may play a role in the inflammation component of the disease. We carried out detailed analysis of the genomic region 250 kb on either side of sentinel SNP rs10167914 and identified 21 transcripts which contained 6 interleukin (IL)-1 family genes, 3 previously reported coding genes that have a relationship to inflammation, 4 novel coding, or pseudogenes, and 8 noncoding RNA transcripts. Through an extensive literature search, we examined the roles these genes and their resultant proteins play in endometriosis pathogenesis. The results suggest alteration in the expression the IL-1 family transcripts either alone or as a complex milieu could have a significant influence on endometriosis and should be prioritized for future study on the implications of inflammation on endometriotic lesions.

Hypoxia Promotes Ectopic Adhesion Ability of Endometrial Stromal Cells via TGF-β1/Smad Signaling in Endometriosis

Hypoxia plays a vital role in the progression of endometriosis. Additionally, integrin-mediated aberrant adhesion is also essential for establishment of endometriotic lesions. In this study, we sought to determine the function of hypoxia in integrin-mediated adhesion of endometrial stromal cells (ESCs) in endometriosis. The expressions of adhesion molecule integrins (integrin α5, integrin αV, integrin β3, and integrin β5) were determined in 15 normal endometria and 15 paired eutopic and ectopic endometria by immunohistochemistry. Thirteen primary ESCs from patients with peritoneal endometriosis in the proliferative phase were cultured under a hypoxic (1% O2) or normoxic (21% O2) environment, and the expression levels of hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β1, and integrins were detected by quantitative reverse transcription polymerase chain reaction and western blot. The alteration of integrins in endometriotic mouse models were also explored. Our results demonstrated that HIF-1α and integrins were highly expressed in ESCs of endometriotic lesions compared with ESCs of eutopic and normal endometrium. Hypoxia treatment significantly increased ESC adhesion abilities and integrin expression, which were positively correlated with TGF-β1 expression. Both TGF-β1 and hypoxia enhanced ESC adhesion properties, whereas hypoxia combined with TGF-β1 receptor inhibitor inhibited ESC adhesion. Knockdown of HIF-1α attenuated TGF-β1/Smad signaling activation and integrin expression and reduced ESC adhesion. Higher expression levels of HIF-1α, TGF-β1, and integrins were detected in endometriotic cysts from mice models. Our findings provide a novel insight of endometriosis that the hypoxic microenvironment stimulates ESCs to produce excessive TGF-β1 and activates the TGF-β1/Smad signaling pathway, thus enhancing integrin expression and the adhesion ability of ESCs.

A Prospective Study of Inflammatory Markers and Risk of Endometriosis

Much evidence suggests a role for inflammation in the pathogenesis of endometriosis. Although investigators in numerous case-control studies have found elevation of inflammatory markers in patients with endometriosis, results were not consistent, and no prior prospective study is known to exist. We conducted a case-control study nested within the Nurses' Health Study II in which we examined associations between levels of plasma inflammatory markers (interleukin-1 beta, interleukin-6, soluble tumor necrosis factor α receptors 1 and 2, and high-sensitivity C-reactive protein) and the risk of laparoscopically confirmed endometriosis. From blood collections in 1996-1999 and 2007, we ascertained 350 cases patients with incident endometriosis and 694 matched controls. Women with interleukin-1 beta levels in quintiles 2-4 had a higher risk of endometriosis (for the second quintile, relative risk (RR) = 3.30, 95% confidence interval (CI): 1.06, 10.3; for the third quintile, RR = 3.36, 95% CI: 1.09, 10.4; and for the fourth quintile, RR = 4.64, 95% CI: 1.58, 13.6; P for trend = 0.62), which suggested an association beginning at 0.47 pg/mL or greater. A significant nonlinear association with levels of soluble tumor necrosis factor α receptor 2 was observed, with elevated risk of endometriosis at concentrations greater than 3,400 pg/mL. Plasma interleukin-6, soluble tumor necrosis factor α receptor 1, and high-sensitivity C-reactive protein levels were not associated with endometriosis risk. Further research in larger studies with younger age at blood collection and longer time from blood to surgical diagnosis are required to confirm these associations.

The role of TGF-β in the pathophysiology of peritoneal endometriosis

BACKGROUND

Endometriosis is estimated to affect 6-10% of women of reproductive age and it is associated with chronic pelvic pain, dysmenorrhoea and subfertility. It is currently managed surgically or medically but symptoms recur in up to 75% of cases and available medical treatments have undesirable side effects. Endometriosis is defined as the presence of endometrial tissue outside the uterus with lesions typically found on the peritoneum. The aetiology of endometriosis is uncertain but there is increasing evidence that transforming growth factor (TGF)-β plays a major role.

OBJECTIVE AND RATIONALE

A descriptive review was undertaken of the published literature on the expression pattern of TGF-β ligands and signalling molecules in women with and without endometriosis, and on the potential roles of TGF-β signalling in the development and progression of peritoneal endometriosis. The current understanding of the TGF-β signalling pathway is summarized.

SEARCH METHODS

We searched the Pubmed database using the terms 'transforming growth factor beta' and 'endometriosis' for studies published between 1995 and 2016. The initial search identified 99 studies and these were used as the basic material for this review. We also extended our remit for important older publications. In addition, we searched the reference lists of studies used in this review for additional studies we judged as relevant. Studies which were included in the review focused on peritoneal endometriosis only as increasing evidence suggests that ovarian and deep endometriosis may have a differing pathophysiology. Thus, a final 95 studies were included in the review.

OUTCOMES

TGF-β1 is reported to be increased in the peritoneal fluid, serum, ectopic endometrium and peritoneum of women with endometriosis compared to women without endometriosis, and TGF-β1-null mice have reduced endometriosis lesion growth when compared to their wild-type controls. Studies in mice and women have indicated that increasing levels of TGF-β ligands are associated with decreased immune cell activity within the peritoneum, together with an increase in ectopic endometrial cell survival, attachment, invasion and proliferation, during endometriosis lesion development. TGF-β1 has been associated with changes in ectopic endometrial and peritoneal cell metabolism and the initiation of neoangiogenesis, further fuelling endometriosis lesion development.

WIDER IMPLICATIONS

Together these studies suggest that TGF-β1 plays a major role in the development of peritoneal endometriosis lesions and that targeting this pathway may be of therapeutic potential.

Expression and Role of Peptides, Proteins and Growth Factors in the Pathogenesis of Endometriosis

Growing evidence is demonstrating that several peptides (corticotrophin-releasing factor, urocortins, ghrelin), proteins (leptin, adiponectin) and growth factors (vascular endothelial growth factor; epidermal growth factor family of growth factors and receptors, fibroblast growth factor, insulin like growth factor and insulin like growth factor-binding proteins, transforming growth factor-β and, activin A and related proteins) are expressed in endometriotic implants, and locally play a relevant role in affecting the biological mechanisms leading to endometriosis. They establish a complex network of interactions by which they are therefore able to stimulate angiogenesis, inflammatory cell recruitment and reaction, the growth of endometriotic tissue and its survival through the modulation of the narrow immune system. This review will evaluate the role played by several regulatory peptides, proteins and growth factors in affecting endometrial physiology and the putative mechanisms advocated to explain endometriosis (angiogenesis, cellular and humoral immunity, inflammatory response, endometrial cell proliferation, activation, motility, adhesion and invasion).

Involvement of Iron, Nuclear Factor-Kappa B (NF-κB) and Prostaglandins in the Pathogenesis of Peritoneal Endometriosis-Associated Inflammation: A Review

Peritoneal endometriosis is a chronic pelvic inflammatory disease, characterized by increased numbers of peritoneal macrophages and their secreted products such as cytokines, growth and angiogenic factors in peritoneal fluid. Inflammation plays a major role in pain and infertility associated with endometriosis, but is also extensively involved in the molecular and cellular processes that lead to peritoneal endometriotic lesion development. Several inflammatory mediators have therefore been studied in the context of endometriosis over the last few years.

The aim of this review is to focus on three that have been clearly implicated in the pathogenesis of endometriosis and may be linked: peritoneal iron metabolism, nuclear factor-kappa B (NF-κB) activation, and prostaglandin biosynthesis.

Peritoneal iron overload has been conclusively demonstrated in endometriosis patients and may induce oxidative stress in the peritoneal cavity. Oxidative stress and proinflammatory cytokines are well known to be potent activators of the NF-κB pathway, which has recently been implicated in peritoneal endometriosis. Induced NF-κB activation leads to expression of numerous proinflammatory genes such as cytokines, which may provide positive feedback to the pathway, self-perpetuating the inflammatory response. Other important NF-κB-regulated molecules are prostaglandin biosynthesis enzymes, and cyclooxygenase-2 (COX-2) in particular. Increased concentrations of prostaglandins have been evidenced in the peritoneal fluid of endometriosis patients and COX-2 inhibitors have proved to be effective in ‘in vitro’ and ‘in vivo’ experimental models.

In the light of available data collected from patient biopsies, as well as ‘in vitro’ and ‘in vivo’ studies, the respective implication and potential molecular association of iron, NF-κB and prostaglandins in the pathogenesis of endometriosis are discussed. The key role of peritoneal macrophages is emphasized and potential therapeutic targets are examined.

ID2 mediates the transforming growth factor-β1-induced Warburg-like effect seen in the peritoneum of women with endometriosis

STUDY QUESTION

Is inhibitor of DNA-binding protein 2 (ID2) a mediator of the transforming growth factor (TGF)-β1-induced Warburg-like effect seen in the peritoneum of women with endometriosis?

SUMMARY ANSWER

The TGF-β1-induced changes in the metabolic phenotype of peritoneal mesothelial cells from women with endometriosis are mediated through the ID2 pathway.

WHAT IS KNOWN ALREADY

TGF-β1 induces the metabolic conversion of glucose to lactate via aerobic glycolysis (the 'Warburg effect') in the peritoneum of women with endometriosis, through increased expression of the transcription factor hypoxia inducible factor α (HIF-1α). ID proteins are transcriptional targets of TGF-β1.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Expression of ID2 was investigated in luteal phase peritoneal biopsies from women with regular menstrual cycles, with and without endometriosis (n = 8-10 each group) by quantitative RT-PCR (qRT-PCR) and immunohistochemistry. ID2 mRNA expression in primary human peritoneal mesothelial cells (HPMC) and immortalized mesothelial cells (MeT-5A) was assessed by qRT-PCR (n = 6). The effects of TGF-β1 and ID2 siRNA on HIF-1α mRNA expression and lactate secretion was assessed using qRT-PCR and a colorimetric lactate assay.

MAIN RESULTS AND THE ROLE OF CHANCE

ID2 is localized to peritoneal mesothelial and stromal cells of women with and without endometriosis. ID2 mRNA expression is lower in peritoneum adjacent to the endometriosis lesions compared to distal sites (P < 0.01). Exposure of HPMC and MeT-5A cells to physiological concentrations of TGF-β1 decreases ID2 mRNA expression (P < 0.01, P < 0.001, respectively, versus control). ID2 knockdown increases HIF-1α mRNA expression (P < 0.01) and lactate secretion (P < 0.05 versus scrambled control) to the same degree as with exposure to TGF-β1.

LIMITATIONS, REASONS FOR CAUTION

Primary human cell cultures and a cell line were used in this study, and thus the results may not fully represent the situation in vivo. The results should also be replicated using a larger number of samples.

WIDER IMPLICATIONS OF THE FINDINGS

Novel therapeutics that target the TGFβ/ID pathway offer a potential role in the treatment of endometriosis.

LARGE SCALE DATA

None.

STUDY FUNDING AND COMPETING INTERESTS

This work was funded by a Wellbeing of Women research grant (R42533) awarded to A.W.H., J.K.B. and W.C.D.; and an MRC Centre Grant G1002033. V.J.Y. received grant support from Federation of Women Graduates (134225) and a PhD studentship from the College of Medicine and Veterinary Medicine at the University of Edinburgh. There are no competing interests to declare.

Endometriosis and ovarian cancer: a review of clinical, pathologic, and molecular aspects

Endometriosis is a chronic disease that affects millions of reproductive-age women. Despite the destructive and invasive nature of endometrioses, most cases are perpetually benign or eventually regress; however, atypical endometriosis is a precursor lesion and can lead to certain types of ovarian cancer. Endometriosis induced inflammation and auto- and paracrine production of sex steroid hormones contribute to ovarian tumorigenesis. These changes provide microenvironment necessary to accumulate enough genetic alterations for endometriosis associated malignant transformation. It takes years for endometriosis to undergo the pathophysiological progression that begins with atypical epithelial proliferation (atypical endometriosis and metaplasia), and then is followed by the formation of well-defined borderline tumors, and finally culminates in fully malignant ovarian cancer. This study is a review of the natural history of endometriosis and the role of microenvironments that favor the accumulation of genetic alterations and endometriosis-associated ovarian cancer progression.

Association of body mass index with severity of endometriosis in Korean women

OBJECTIVE

To investigate the relationship between endometriosis severity and body mass index (BMI).

METHODS

Of 481 women seen for endometriosis at a university hospital in Korea, 153 had stage I, 113 had stage II, 110 had stage III, and 105 had stage IV disease. The patients' BMIs were categorized according to World Health Organization criteria for Asian-Pacific populations.

RESULTS

Women with early or mild endometriosis (stages I or II) had a significantly higher BMI than those with advanced disease (stages III or IV) (P<0.001). After adjusting for age, parity, and menstrual factors, an association between BMI and disease stage remained significant (P<0.001).

CONCLUSION

Women with advanced-stage endometriosis had lower BMIs than those with minimal or mild disease, and BMI was significantly associated with disease severity.

Increased activation of nuclear factor-kappa B (NF-κB) in isolated peritoneal macrophages of patients with endometriosis

Endometriosis is characterized by pelvic inflammation that shows an increased number of activated peritoneal macrophages and their secreted products such as cytokines, growth factors, and angiogenic factors. Our results show that activation of nuclear factor-kappa B (NF-kappaB), a pro-inflammatory transcription factor, is statistically significantly increased in peritoneal macrophages from patients with endometriosis when compared with controls.

[Pathogenesis of endometriosis]

Endometriosis, defined by the development of endometrial tissue outside the uterus, is a benign disease responsible for infertility and pelvic pain. The diagnosis based on a detailed gynecological history and a careful clinical examination should be done as early as possible in order to treat patients correctly. Medical treatment is not appropriate in all cases and surgical treatment should be proposed but morbidity is related to the severity of the lesion. Ectopic implantation of endometrial cells needs complex interactions between host tissue and epithelial endometrial cells. The conditions for the development of endometriosis are estrogeno-dependent growth of endometrial cells, induction of angiogenesis and lymphangiogenesis. Principal cellular and molecular factors of angiogenesis, lymphangiogenesis and fibrosis should be identified in order to develop new therapeutic strategies of endometriosis.

Neuroendocrine-immune disequilibrium and endometriosis: an interdisciplinary approach

Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity, affects one fourth of young women and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology and effective treatment strategies of endometriosis is still largely elusive. Inadequate immune and neuroendocrine responses are significantly involved in the pathophysiology of endometriosis, and key findings are summarized in the present review. We discuss here the role of different immune mechanisms particularly adhesion molecules, proteinglycan interactions, and pro-angiogenic mediators in the development and progression of the disease. Finally, we introduce the concept of endometrial dissemination as result of a neuroendocrine-immune disequilibrium in response to high levels of perceived stress caused by cardinal clinical symptoms of endometriosis.

Tumour necrosis factor-alpha, interleukin-6 and interleukin-8 do not promote adhesion of human endometrial epithelial cells to mesothelial cells in a quantitative in vitro model

BACKGROUND

A key factor in the pathogenesis of endometriosis is the endometrial-peritoneal adhesion. To study the pathogenesis of endometriosis, a quantitative in vitro assay (QIVA) was developed to measure in vitro adhesion between human endometrial epithelial cells and mesothelial cells using commercially available cell lines. Using the QIVA, the hypothesis was tested that tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) promote adhesion of endometrial epithelial cells to mesothelial cells.

METHODS

Mesothelial cells were pre-treated with TNF-alpha, IL-6 or IL-8 in various concentrations (ranging from 0 to 1000 IU/ml) for 24 h. Confluent endometrial epithelial cells were labelled with [35S]methionine, added to the confluent mesothelial cells and incubated for 1 h. After incubation, non-adhering cells were removed and adherent cells were solubilized and their [35S]methionine radioactivity was counted to quantify the adherence of endometrial epithelial cells to mesothelial cells.

RESULTS

The in vitro adhesion of human endometrial epithelial cells to human mesothelial cells was inhibited in a dose-dependent manner by TNF-alpha (P=0.0007), IL-6 (P<0.0001) and IL-8 (P=0.0004).

CONCLUSIONS

Using a quantitative in vitro adhesion assay, we were unable to confirm our hypothesis that TNF-alpha, IL-6 and IL-8 promote the in vitro adhesion between endometrial epithelial cells and mesothelial cells.

The Effect of Chinese Herbs on the Cytokines of Rats with Endometriosis

OBJECTIVE

The aim of this study was to study the regulatory function of Chinese medicine-YiWeiNing (YWN) on the cytokines of endometriosis (EM) model rats.

MATERIALS AND METHODS

After successfully creating EM models of rats, all were separated randomly into five groups: high dose of YWN (5.4 g/100 g), low dose of YWN (1.8 g/100 g), Danazol group (3.6 mg/100 g), a model group, and a false-operation group. They were then reviewed for the variation of the amount of TNF-alpha (tumor necrosis factor-alpha), interleukin-6 (IL-6), and interleukin-8 (IL-8).

RESULTS

The content of TNF-alpha, IL-6, and IL-8 in the peripheral blood of the model group was apparently higher than the false-operation group (p < 0.01), and YWN reduced the amount of TNF-alpha, IL-6, and IL-8 in the serums of the model group's rats. This made these cytokines tend toward normal levels without an apparent variation, when compared with the false-operation group (p > 0.05).

CONCLUSIONS

YWN can prevent the growth of ectopic endometrium by inhibiting the synthesis and secretion of TNF-alpha, IL-6, and IL-8.

Efficacy of three adhesion-preventing agents in reducing severe peritoneal trauma induced by bipolar coagulation in a laparoscopic rat model

OBJECTIVE

To compare the antiadhesion efficacy of three agents (4% icodextrin, ferric hyaluronate gel, and Ringer's lactate) in severe peritoneal trauma caused by bipolar coagulation in a laparoscopic rat model.

DESIGN

Prospective, randomized, blinded experimental study.

SETTING

International Laparoscopic Surgery Centre, Clermont-Ferrand, France.

ANIMAL(S)

Female Sprague-Dawley rats.

INTERVENTIONS

Animals were prospectively randomized to receive one of the three agents or to be controls. Coagulation of the parietal peritoneum was performed using a bipolar 40-W current followed by administration of an antiadhesion agent. Postoperative adhesion assessment was carried out on day 7 in 42 rats.

MAIN OUTCOME MEASURE(S)

Adhesions were scored according to their extent and severity.

RESULT(S)

Adhesions occurred in all rats, however, adhesion and vascular adhesion rate scores were significantly higher in controls compared with treated groups. Adhesions were more likely to be filmy and easily separable in the 4% icodextrin group compared with the Ringer's lactate solution group.

CONCLUSION(S)

Adhesion scores were decreased by the use of antiadherent agents. However, no rats were found to be free of adhesions after severe peritoneal trauma induced by 40-W bipolar coagulation of the peritoneum.

Reduction of apoptosis and proliferation in endometriosis

OBJECTIVE

To evaluate whether endometriosis could be related to an impaired balance between apoptosis and proliferation, two processes which could be modulated by hormonal status.

DESIGN

Immunohistochemical study.

SETTING

Academic research laboratory.

INTERVENTION(S)

Endometriotic samples obtained from peritoneum of women aged 26-40 years who were undergoing laparoscopy for pain or infertility.

MAIN OUTCOME MEASURE(S)

Apoptotic cells were detected with the use of the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. The production of p53 and bcl-2, estrogen and Progesterone (P) receptors, and cellular proliferation were assessed by immunohistochemistry in eutopic and ectopic endometria from 30 patients with endometriosis throughout the menstrual cycle. Results were compared with those from normal endometria from 15 fertile patients.

RESULT(S)

Endometriotic lesions were characterized by reduced TUNEL and p53 stainings and by enhanced bcl-2 staining. No correlation between apoptosis and estrogen receptor or P receptor levels was found. A lower amount of steroid receptor was found in endometriotic tissues, without cyclic modulation, compared with the eutopic endometrium.

CONCLUSION(S)

Our results suggest that when endometrial tissue is located at ectopic locations, it differs from eutopic endometrium by its proliferation rate, steroid hormone levels, and markers of apoptosis. A reduced sensitivity of endometriotic cells to apoptosis could promote the dissemination and implantation of these cells to ectopic sites.