Growth Of Ectopic Endometrial Tissue Research Articles

Proangiogenetic molecules, hypoxia-inducible factor-1α and nitric oxide synthase isoforms in ovarian endometriotic cysts

Endometriosis is a common disease characterised by ectopic growth of endometrial tissue outside the uterine cavity. Angiogenesis has been implicated in the pathogenesis of the disease; some molecules, like hypoxia-inducible factor-1alpha (HIF-1alpha) and neuronal, endothelial and inducible nitric oxide synthase isoforms (nNOS, eNOS and iNOS), are known as proangiogenetic factors. We evaluated expression of these molecules by immunohistochemistry in 32 cases of ovarian endometriomas, formalin-fixed and paraffin-embedded. Analysis was focused on the cells composing the inner layer of the cyst, constituted by the ectopic endometrial glands, stromal cells and vessels, and the outer one, constituted by a fibrous layer of fibroblasts and vessels. We found that epithelial glands and capsular vessel endothelial cells showed a correlated expression of NOS isoforms; that expression of nNOS, iNOS and HIF-1alpha was correlated in epithelial glands and capsular fibroblasts; that vessel endothelial cells showed a higher mean expression for all the proangiogenetic molecules in the outer layer than in the inner one; and that capsular fibroblasts showed a higher mean expression for HIF-1alpha, iNOS and eNOS compared to the specialised stromal cells of the inner layer. Our data seem to indicate that angiogenesis is stimulated more in the outer capsule than in the inner layer of ovarian endometriotic cysts. The knowledge of the complex mechanisms associated to angiogenesis might be useful in a therapeutic approach of ovarian endometriosis based on anti-angiogenetic drugs. The therapeutic target would be mainly the capsular vasculature, more than the vasculature of ectopic endometrial tissues.

Mevalonate-Ras Homology (Rho)/Rho-Associated Coiled-Coil-Forming Protein Kinase (ROCK)-Mediated Signaling Pathway as a Therapeutic Target for the Treatment of Endometriosis-Associated Fibrosis

a disease affecting 3-10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue. Histologically, this disease is characterized by endometrial gland and stroma with surrounding dense fibrous tissue. During the development of endometriotic lesions, excess fibrosis may lead to scarring and to altera- tion of the tissue function. It has been suggested that type I collagen is a major contributor to endometriosis-associated fibrosis. One approach to understanding the pathogenesis of endometriosis is to investigate the mechanisms underlying fibrogenesis associated with this disease. Using three-dimensional collagen gel culture model, we have evaluated the extracellular matrix contractility and myofibroblastic differentiation of endometriotic stromal cells. Endometriotic stromal cells showed enhanced extracellular matrix contractility in comparison with normal endometrial stromal cells. Activation of the Ras homology (Rho)/Rho- associated coiled-coil-forming protein kinase (ROCK)-mediated signaling pathway with simultaneously enhanced myofi- broblastic differentiation is involved in this mechanism. We have proposed the mevalonate-Rho/ROCK-mediated signal- ing pathways as possible therapeutic targets for the treatment of endometriosis-associated fibrosis. This paper is a review of the recent information concerning the mechanism of endometriosis-associated fibrosis, focusing on the contractility of endometriotic stromal cells. The modulators of mevalonate-Rho/ROCK signaling pathways were also evaluated as promising agents for the treatment and prevention of endometriosis-associated fibrosis.

Cytological diagnosis of peritoneal endometriosis

Sir, Endometriosis is a common disease characterized by ectopic growth of endometrial tissue that responds to hormonal stimulation. It primarily affects women in the reproductive age group with mixed symptomatology. Cytological features of endometrial cells in peritoneal fluid are not well described, which we wish to highlight. A 30-year-old woman presented with lower abdominal pain and dysmenorrhoea of 1 year duration. On examination, she had mild ascites. Bilateral cysts were seen near the fallopian tube on laparoscopy. Diagnostic considerations included neoplastic process or pelvic endometriosis. A peritoneal wash was performed and 100 mL of haemorrhagic fluid was sent for cytological examination. On microscopy, the fluid showed the presence of endometrial cells. The glandular epithelial cells were arranged in variably sized spheres in which the periphery showed epithelial cells, along the border and as a honeycombed sheet, with a cluster of stromal cells in the centre having hyperchromatic nuclei, scant cytoplasm and indistinct cytoplasmic borders [Figure 1]. There was no nuclear atypia and the nucleoli were inconspicuous. Some of the fragments were arranged in a small ball-like configuration in which there was cytoplasm resembling mesothelial cells [Figure 2]. Their three-dimensional nature and tight grouping set them apart from the loose sheets of mesothelial cells of the peritoneal wash. A few hemosiderin-laden macrophages were identified. A cytological diagnosis of endometriosis was made. Figure 1 Large endometrial fragment in peritoneal wash fluid showing epithelial lining on the outside, seen on the sides and as honeycombed cells as well as compact stromal cells within (PAP, ×400) Figure 2 Small spherule of endometrial cells in three-dimensional arrangement, which has to be differentiated from reactive mesothelial cells (PAP, ×400) The utility of peritoneal wash cytology for diagnosis of endometriosis has been reported.[1,2] In most cases, only hemosiderin-laden macrophages are identified.[2–5] The presence of endometrial cells is more specific but less sensitive than hemosiderin-laden macrophages for the diagnosis of endometriosis. The endometrial cells have been reported in 25%–52% of peritoneal washes done in endometriosis.[1,5] However, recognition of endometrial cells as well as hemosiderin-laden macrophages is essential for diagnosis on morphological basis alone.[6,7] The descriptions, diagnostic features and illustration of endometrial cell morphology in the peritoneal wash fluid is restricted to a few reports.[3,6] The distinction of endometrial cells from mesothelial cells and adenocarcinoma cells is important. Endometrial cells come in three-dimensional fragments that do not resemble mesothelial cells architecturally in washings which are arranged in sheets. However, endometriosis may elicit reactive mesothelial proliferation, which form three-dimensional fragments with calcific concretions, which are difficult to distinguish from endometrial cells.[5] Larger endometrial cell fragments may include stromal cells, which is a useful feature for differentiation as seen in the present case. Presence of hemosiderin-laden macrophages is indirect evidence of endometriosis. In the presence of an adnexal mass, a well-differentiated adenocarcinoma is always a diagnostic consideration and needs to be ruled out by the absence of atypia in the small cells and nuclei of endometrial cells. This distinction becomes difficult if there is reactive mesothelial proliferation in case of endometriosis.[2,5] The use of cell blocks and immunocytochemistry for epithelial and mesothelial cell markers can greatly aid diagnosis in distinction between reactive mesothelial fragments on one side and endometriosis and adenocarcinoma on the other.[2] Correlation with clinical and operative features is essential before cytological diagnosis.

Involvement of resistance to apoptosis in the pathogenesis of endometriosis.

Endometriosis, a disease affecting 3-10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue. Increasingly, endometriosis is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a 'death' signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of anti-apoptotic factors and decreased expression of pre-apoptotic factors. This paper is a review of the recent literature focused on the differential expression of apoptosis-associated molecules in the normal endometria of women without endometriosis, and in the eutopic and ectopic endometria of women with endometriosis. The role of apoptosis in the pathogenesis of endometriosis and the basic and clinical research on the current medical treatment for endometriosis from the view of apoptosis will be discussed.

Endometriosis and Organochlorinated Environmental Pollutants: A Case–Control Study on Italian Women of Reproductive Age

BackgroundEndometriosis is a common gynecologic disease characterized by the ectopic growth of endometrial tissue. In industrialized countries, it affects approximately 10% of women of reproductive age. Its etiology is unclear, but a multifactorial origin is considered to be most plausible. Environmental organochlorinated persistent pollutants, in particular dioxins and polychlorinated biphenyls (PCBs), have been hypothesized to play a role in the disease etiopathogenesis. However, results of studies carried out on humans are conflicting.ObjectiveWe evaluated the exposure to organochlorinated persistent pollutants as a risk factor for endometriosis.MethodsWe conducted a case–control study in Rome on 158 women comprising 80 cases and 78 controls. In all women, serum concentrations of selected non-dioxin-like PCBs (NDL-PCBs) and dioxin-like PCBs (DL-PCBs), 1,1-dichloro-2,2,-bis(4-chlorophenyl)-ethene (p,p′-DDE), and hexachlorobenzene (HCB) were determined by ion-trap mass spectrometry. DR-CALUX bioassay was employed to assess the 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent (TEQ) concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and DL-PCBs.ResultsWe found an increased risk of endometriosis for DL-PCB-118 [odds ratio (OR) = 3.79; 95% confidence interval (CI), 1.61–8.91], NDL-PCB-138 (OR = 3.78; 95% CI, 1.60–8.94), NDL-PCB-153 (OR = 4.88; 95% CI, 2.01–11.0), NDL-PCB-170 (OR = 3.52; 95% CI, 1.41–8.79), and the sum of DL-PCBs and NDL-PCBs (OR = 5.63; 95% CI, 2.25–14.10). No significant associations were observed with respect to HCB or to the sum of PCDDs, PCDFs, and DL-PCBs given as total TEQs.ConclusionsThe results of this study show that an association exists between increased PCB and p,p′-DDE serum concentrations and the risk of endometriosis.

Marked Expression of Macrophage Migration Inhibitory Factor in the Intrauterine Endometrium of Women With Endometriosis Varying With the Disease Stage, the Infertility Status and Pelvic Pain

Marked Expression of Macrophage Migration Inhibitory Factor in the Intrauterine Endometrium of Women With Endometriosis Varying With the Disease Stage, the Infertility Status and Pelvic Pain

Quantitative Assessment of Human Endometriotic Tissue Maintenance and Regression in a Noninvasive Mouse Model of Endometriosis

Endometriosis is a prevalent disease characterized by the estrogen-dependent ectopic growth of endometrial tissue. Most of the current medical therapies consist in inducing a hypoestrogenic state in patients, but these treatments are associated with severe side effects and high recurrence rates. The development of convenient and reliable endometriosis animal models would be instrumental to accelerate the emergence of new therapeutic alternatives. Recently, we developed an improved experimental model for endometriosis, relying on the infection of human endometrial fragments by an adenovirus carrying the green fluorescent protein. Following injection of fluorescent fragments into nude mice, the implantation and growth of endometriotic-like lesions could be followed noninvasively. In the present work, we demonstrate that this model can be used to quantify the size of fluorescent endometriotic lesions by in vivo imaging. To this end, we repeatedly measured lesion size over a 4-week period in mice supplemented or not with estradiol. The model was adequate to confirm previous results showing that estrogen is dispensable for the implantation phase of endometrial tissue, whereas it is required for lesion maintenance. As a proof of concept for inducing regression of established lesions, ganciclovir was used to treat animals implanted with human fluorescent endometrial fragments expressing thymidine kinase. A significant decrease in lesion size was observed by in vivo imaging in ganciclovir-treated mice. Together, the data indicate that the noninvasive animal model described here provides a tool for drug testing and/or gene target validation in endometriosis.

Therapeutic Effect of Angiostatin Gene Transfer in a Murine Model of Endometriosis

Endometriosis, the growth of ectopic endometrial tissue, is a chronic recurrent disease affecting 10% of the female population causing dyspareunia, pelvic pain, dysmenorrhea, and infertility. Suppression of ovarian activity is the cornerstone of medical therapy with limited benefit and severe adverse effects. Angiogenesis plays a major role in the development of endometriosis suggesting that anti-angiogenic therapy would offer a new therapeutic approach. We report successful treatment of endometriosis in estrogen-supplemented ovariectomized mice by transient overexpression (6 to 10 days of duration) of the gene for a natural angiogenesis inhibitor angiostatin, delivered to the peritoneum by a replication-deficient adenovirus vector (AdAngiostatin). Established endometriosis was eradicated in 14 of 14 AdAngiostatin-treated animals, whereas 11 of 13 control animals showed full disease development. Administered to normal cycling mice for the same transient period, AdAngiostatin caused impaired ovarian function with suppressed corpus luteum development, decreased production of estradiol and progesterone, decreased ovarian and uterine weight, and increased body weight. AdAngiostatin treatment lowered the levels of sex steroids but did not induce total castration. Gene therapy with angiogenic inhibitors is a highly effective treatment for endometriosis, even in a host with preserved estrogen levels. However, local or targeted delivery of the gene must be considered to avoid prolonged systemic effects and impaired ovarian function.

Endometrial anomalies in women with endometriosis.

Endometriotic lesions are defined by extrauterine growth of endometrial glands and stroma. Retrograde menstruation with subsequent attachment, invasion, and neovascularization are believed to give rise to the endometriotic lesions. As most women exhibit some degree of retrograde menstruation, some other unidentified factor(s) must render certain women susceptible to attachment and growth of ectopic endometrial tissue. A variety of theories have been proposed to account for this susceptibility, including genetic predisposition, aberrant immunological response, and an altered peritoneal environment. Ectopic endometriotic lesions are histologically similar to their putative eutopic precursors, yet significant biochemical differences exist between these two tissues. Less information is available regarding differences between eutopic endometrium from women with or without endometriosis. This report describes anomalies in structure, proliferation, immune components, adhesion molecules, proteolytic enzymes and inhibitors, steroid and cytokine production and responsiveness, and gene expression and protein production that have been identified in eutopic endometrium from women with endometriosis.