Vascular endothelial growth factor A and C gene expression in endometriosis

Angiogenesis is essential for the pathogenesis of endometriosis. Gene expression levels of vascular endothelial growth factor (VEGF) A and C in 10 eutopic endometrial, 23 normal peritoneal, and 62 endometriotic tissues surgically obtained from 47 women with endometriosis (group 2) were compared with those in 12 control eutopic endometrial and 9 normal peritoneal tissues from 15 women without endometriosis (group 1). VEGF-A mRNA expression levels in eutopic endometrium of group 2 were higher than those of group 1 throughout the menstrual cycle (P <0.01) and increased in the secretory phase. VEGF-A gene expression in peritoneal endometriotic lesion was statistically higher than that in normal peritoneum (P <0.01) and similar to that in eutopic endometrium of group 2. In contrast, gene expression levels of VEGF-C were relatively lower than those of VEGF-A in each lesion, and no cyclic variation was found. VEGF-A and C mRNA expression levels were significantly higher in ovarian endometriomas >6 cm in size than in those <6 cm in size. Immunohistochemical expression of VEGF-A and C was detected in the cytoplasm of glandular epithelial and stromal cells of ovarian endometrioma. These results suggest that endometriosis may arise from eutopic endometrium with higher levels of angiogenic activity possibly induced by VEGF-A in women with endometriosis. Moreover, VEGF-C as well as VEGF-A may be involved in the pathogenesis of ovarian endometrioma.     

Expression of angiogenic factors in endometriosis: relationship to fibrinolytic and metalloproteinase systems

BACKGROUND: Endometriosis is a highly prevalent, benign disease in which the angiogenic, fibrinolytic and metalloproteinase (MMP) systems may be implicated. The objective of this study is to analyse mRNA expression and protein levels of several angiogenic factors and to correlate them with several components of the fibrinolytic and MMP systems in samples from 71 women with endometriosis and 50 controls. METHODS AND RESULTS: Eutopic endometrium showed higher mRNA expression of vascular endothelial growth factor (VEGF) in patients than in controls. However, ovarian endometrioma had lower VEGF mRNA levels than did the eutopic endometrium of patients. Similar results were obtained for VEGF protein levels. On the other hand, a significant increase in thrombospondin-1 (TSP-1) levels was observed in ovarian endometrioma than in eutopic endometrium. The peritoneal fluid from women with endometriosis showed a significant increase in VEGF, urokinase-type plasminogen activator (uPA) and MMP-3 levels than that of controls. A significant correlation was observed between the levels of VEGF and uPA in endometrium and in peritoneal fluid. CONCLUSIONS: Endometrium and peritoneal fluid from women with endometriosis have increased levels of VEGF, uPA and MMP-3 levels. Therefore, the development of endometriotic implants at ectopic sites may be facilitated, promoting the progress of the endometriosis.     

雌激素受体不同亚型在卵巢子宫内膜异位症在位内膜与异位内膜中的表达及其意义

目的 研究雌激素受体(ER)不同亚型在子宫内膜异位症的在位和异位内膜中的表达,以寻找其在不同病灶中的分布规律,探讨子宫内膜异位症的发病机制.方法 收集解放军总医院2004年1月-2006年12月行手术治疗的卵巢子宫内膜异位症石蜡标本,包括卵巢子宫内膜异位囊肿60例及其在位内膜60例(增生期各30例、分泌期各30例)以及正常子宫内膜30例(增生期和分泌期各15例).采用免疫组织化学(EnVision)方法检测上述组织中ERα和ERβ的表达.染色结果半定量化,并分析比较各种组织间的表达差异.结果 各组中,ERα和ERβ在腺上皮的表达与它们在间质细胞中的表达呈正相关.ERα蛋白在不同部位的表达:在位内膜ERα的表达(腺上皮和间质细胞阳性率分别为73.3%和76.7%)高于卵巢子宫内膜异位囊肿(腺上皮和问质细胞阳性率分别为43.4%和46.7%)和正常内膜的表达(腺上皮和间质细胞阳性率分别为56.7%和50.0%),均P<0.05.ERβ蛋白在不同部位的表达:卵巢子宫内膜异位囊肿(腺上皮和间质细胞阳性率分别为90.0%和76.7%)高于在位子宫内膜的表达(腺上皮和间质细胞阳性率分别为68.0%和63.3%),后者又高于正常子宫内膜(腺上皮和间质细胞阳性率分别为36.7%和26.7%),P均<0.05.在位内膜的ERα和ERβ蛋白表达在增殖期均高于分泌期,P均<0.05;异位内膜增殖期和分泌期的表达差异无统计学意义.ERα和ERβ蛋白在不同部位表达的比较:在正常内膜中ERα的表达略高于ERβ,但差异无统计学意义,P>0.05;卵巢子宫内膜异位囊肿中ERβ的表达高于ERα,P<0.05;而在位内膜中两种亚型表达差异无统计学意义.结论 子宫内膜异位症患者在位子宫内膜及异位内膜均有ERα和ERβ的表达,但与正常子宫内膜相比,在卵巢子宫内膜异位囊肿中ERβ表达占优势,而ERα表达受限.ERα和ERβ在不同组织中的分布及表达水平与子宫内膜异位症的发生和发展有着密切关系.     

Interleukin 1alpha and tissue-lytic matrix metalloproteinase-1 are elevated in ectopic endometrium of patients with endometriosis

BACKGROUND: Matrix metalloproteinases (MMP) play an essential role in tissue remodelling and menstruation and appear to be regulated by cytokines such as interleukin-1alpha (IL-1alpha). In order to investigate their role in the pathogenesis of endometriosis, the aim of the present study was to compare the protein localization of matrix metalloproteinase-1 (MMP-1) and of its main stimulatory cytokine IL-1alpha in eutopic and dystopic endometrium of patients with endometriosis. METHODS: MMP-1 and IL-1alpha protein localization was analysed retrospectively in paired paraffin-embedded tissue biopsies obtained simultaneously from the endometrial cavity and from endometrial lesions of 37 patients with peritoneal or ovarian endometriosis and in cycling endometria from 37 women without endometriosis. Protein localization was demonstrated by immunohistochemistry; antibody specificity was confirmed by western blot analysis. RESULTS: MMP-1 and IL-1alpha protein staining in women suffering from endometriosis was significantly more pronounced in endometriotic lesions than in eutopic endometrium. This held true for both epithelial MMP-1 and IL-1alpha staining (P < 0.006 and P < 0.001), and for stromal MMP-1 and IL-1alpha staining (P < 0.001 and P < 0.001). Furthermore, stromal MMP-1 and IL-1alpha were significantly co-expressed in dystopic endometriotic tissue (P = 0.045). Endometrial MMP-1 and IL-1alpha protein expression pattern in eutopic endometrium from women suffering from endometriosis, however, did not differ significantly from the pattern seen in healthy women. CONCLUSIONS: The increased expression of both matrix-degrading MMP-1 and its major stimulatory cytokine IL-1alpha in endometriotic lesions and the selective co-expression in the stroma of endometriotic foci clearly suggests their involvement in the pathogenic mechanisms leading to local invasion and tissue destruction.     

子宫内膜及异位灶趋化因子受体转录在子宫内膜异位症发病中的作用

目的：探讨子宫内膜异位症患者在位内膜及异位灶18种趋化因子受体的转录特征，以揭示趋化因子受体及其配体在子宫内膜异位症发生发展中的作用。方法：以正常子宫内膜为对照，半定量RT-PCR检测子宫内膜异位症患者在位内膜及异位灶18种趋化因子受体mRNA的表达水平，并比较其差异。结果：与正常子宫内膜相比，子宫内膜异位症患者在位子宫内膜CCR6、CCR8、CCR9、CX3CR1表达明显升高（P＜0．05）。与在位内膜相比，异位灶CCR4、CCR8、CCR9、CXCR1表达显著升高（P＜0．05）。结论：在位子宫内膜CCR6、CCR8、CCR9、CX3CR1高表达，可能参与子宫内膜异位症的发生；异位灶CCR4、CCR8、CCR9、CXCR1高表达，可能参与子宫内膜异位症的进一步发展。     

Expression of several components of the plasminogen activator and matrix metalloproteinase systems in endometriosis

BACKGROUND: Endometriosis is considered a benign disease that has the ability to invade normal tissue. As in neoplastic growth, local extracellular proteolysis may take place. The aim of this study is to analyse several components of the plasminogen activator (PA) pathway and the matrix metalloproteinase (MMP) system in endometriotic tissue, endometrium and peritoneal fluid from women with and without endometriosis (controls). METHODS AND RESULTS: Thirty-nine women with endometriosis and 35 controls were studied. In eutopic endometrium of women with endometriosis, the antigenic levels of urokinase-type PA (uPA) and MMP-3 were elevated when compared with endometrium from controls. Ovarian endometriotic tissues had higher antigenic levels of PA inhibitor type 1 (PAI-1) and tissue inhibitor of metalloproteinases type 1 (TIMP-1) than endometrium. The peritoneal fluid from women with endometriosis showed a significant increase in uPA levels compared with controls. CONCLUSIONS: The increase in antigenic levels of uPA and MMP-3 in endometrium of women with endometriosis might contribute to the invasive potential of endometrial cells. Once the ovarian endometriotic cyst is developed, an increase in PAI-1 and TIMP-1 is detected and significant proteolytic activity is no longer observed. This increase in inhibitors and decrease in proteolytic activity could explain the frequent clinical finding of isolated endometriotic cyst without invasion of the surrounding ovarian tissue.     

Differential expression and localization of de-novo synthesized endometriotic haptoglobin in endometrium and endometriotic lesions

Endometriosis protein-I (ENDO-I) mRNA expression and protein localization were evaluated using in-situ hybridization and immunohistochemistry in endometriotic lesions and eutopic endometrium from women with endometriosis, and in eutopic endometrium from women without endometriosis (controls). When present, ENDO-I mRNA and protein were observed in the functionalis zone of endometrial stroma and the stroma of endometriotic lesions. Expression and localization differences were scored and statistically analysed. During the secretory stage, ENDO-I mRNA expression by endometriotic lesions and eutopic endometrium from women with disease was significantly greater than ENDO-I mRNA expression by proliferative stage eutopic endometrium from women with disease or eutopic endometrium from controls, regardless of cycle stage (P < 0.001). More ENDO-I protein was localized in endometriotic lesions and eutopic endometrium from women with disease than in eutopic endometrium from controls, regardless of cycle stage (P < 0.001). Differential expression and localization of ENDO-I may help develop minimally invasive diagnostic strategies for endometriosis. Further, as ENDO-I shares nucleotide sequence and amino acid sequence with hepatic haptoglobin-which in certain disease states is immunosuppressive and angiogenic-differences in ENDO-I expression and localization in the peritoneal cavity may contribute to the pathogenesis of endometriosis and/or facilitate development of unprecedented diagnostic or therapeutic approaches for management of this enigmatic disease.     

Endometriotic disease: the role of peritoneal fluid

Peritoneal fluid and the intraovarian milieu are a specific microenvironment. Peritoneal fluid originates mainly as an ovarian exudation product caused by increased vascular permeability, with cyclic variation in volume and steroid hormones which are always higher than in plasma. It contains large amounts of macrophages and their secretion products, and has a large exchange area with plasma through the peritoneum, which is highly permeable for small molecules. Diffusion becomes virtually zero for molecules with a molecular weight of >100000 Da. In women with the luteinized unruptured follicle (LUF) syndrome, concentrations of oestrogens and progesterone are much lower in the luteal phase. Endometriosis is associated with sterile low-grade inflammation, increased concentrations of activated macrophages and many of their secretions, such as cytokines, growth factors and angiogenic factors. Concentrations of CA-125 and of glycodelins are also increased, secreted locally by the endometrial cells. Natural killer (NK) cell function declines, possibly mediated by glycodelins or local intercellular adhesion molecule (ICAM) -1 shedding. The ovary is also a specific microenvironment, with steroid hormone concentrations 1000-fold higher in follicles than in plasma. Endometrial and superficially implanted cells are influenced by peritoneal fluid concentrations so that local environment, rather than inherent cellular differences could explain differences between superficial endometriosis and eutopic endometrium. Differences between superficial implants and endometriotic disease, deep infiltrating or cystic ovarian endometriosis, may thus arise via different endocrine environments. Superficial endometrial implants are regulated by peritoneal fluid factors, whereas deep endometriosis and cystic ovarian endometriosis are influenced by blood or ovarian factors. The endometriotic disease theory considers superficial endometriotic implants and their remodelling as a physiological process in most women, and concentrates on the causes of severe endometriosis such as differences in the eutopic endometrium from women with and without endometriosis (which may indicate hereditary differences), the invasiveness of some endometriotic cells in vitro, focal 'shielding' of endometriotic foci by adhesions, and inhibition of NK activity by ICAM-1 and glycodelins. Endometriotic disease is thus seen as a benign tumour. The type of cellular lesion, hereditary and immunological environments and local hormone concentrations in the ovary and in peritoneal fluid, will decide expression as cystic ovarian endometriosis, deep endometriosis or adenomyosis externa, and whether the latter is associated with adhesions.     

Transcriptional expression of survivin and its splice variants in endometriosis

Survivin is a novel inhibitor of apoptosis (IAP), and the two splice variants of survivin (survivin-2B and survivin-EX3) have been identified. Gene expression levels of survivin, survivin-2B and survivin-EX3 in 56 ectopic (16 peritoneal red and 16 peritoneal black lesions and 24 ovarian endometriomata) and 13 eutopic endometrial tissues surgically obtained from 42 women with endometriosis (group A) were compared with those in 16 control eutopic endometrium from 16 women without endometriosis (group B) by quantitative RT-PCR analysis. Survivin mRNA expression levels in ectopic endometriotic tissues were significantly higher than those in eutopic endometrium of groups A and B over the whole cycle. Red peritoneal lesions had higher gene expression levels of survivin than black lesions. In contrast, all tissue samples examined showed relatively lower gene expression levels of survivin-2B and survivin-EX3. No cyclic variation was found in survivin and the two splice variants, both in ectopic and in eutopic endometrium. Although there was no significant difference in the ratio of survivin-2B/survivin between ectopic and eutopic endometrium, the ratio of survivin-EX3/survivin in peritoneal endometriotic lesions was significantly higher than that of eutopic endometrium of groups A and B. These results suggest that survivin and survivin-EX3 may be closely linked to escape from apoptosis and the development of endometriosis.     

子宫内膜异位症中miR-556-3p的异常表达及其与血管内皮生长因子的关系

目的探索micro RNA-556-3p（mi R-556-3p）在子宫内膜异位症中的表达模式及其与血管内皮生长因子（vascular endothelium growth factor,VEGF）的关系。方法子宫内膜异位症患者15例作为研究组,分别收集在位内膜、卵巢异位内膜及腹膜异位内膜;无子宫内膜病变的妇女16例,收集子宫内膜组织作为对照组。Taqman real-time PCR检测上述组织中mi R-556-3p的水平,Western Blot法检测组织中VEGF蛋白含量,并分析mi R-556-3p与VEGF表达水平之间的相关性。结果与对照组相比较,内异症患者在位内膜及腹膜异位病灶中mi R-556-3p水平显著降低（P〈0.001）,而VEGF含量在内异症在位内膜、卵巢异位囊肿或腹膜异位内膜中均显著升高（P值分别为〈0.001、0.02、〈0.001）;与内异症组在位内膜相比较,卵巢异位病灶中mi R-556-3p显著升高（P〈0.001）,腹膜异位病灶中mi R-556-3p的表达量则显著降低（P〈0.001）,而VEGF显著升高（P〈0.001）;异位症组在位内膜及腹膜异位病灶中mi R-556-3p与VEGF蛋白的表达量呈显著负相关（r值分别为-1.026、-1.819,P值分别为0.01、0.04）。结论内膜组织中mi R-556-3p表达异常可能导致VEGF蛋白表达失调,参与子宫内膜异位症的发生发展。     

The history of endometriosis: identifying the disease.

The history of endometriosis is reviewed in the light of today's clinical and pathological knowledge of this disease. Prior to Sampson's report in 1921, attention was focused on the enclosed type of endometriosis, sited deep in the pelvis and called adenomyosis externa. Sampson's first hypothesis, that rupture of an ovarian endometrioma caused superficial peritoneal endometriosis, was probably changed after this observation that the free, superficial peritoneal implants reacted like eutopic endometrium. These implants were recognized as implants from menstrual blood regurgitated into the pelvic cavity. Adenomyosis externa, ovarian endometrioma and peritoneal endometriosis then came to be regarded as the same disease. In the light of today's knowledge, it may be important to remember this progressive understanding in the nosology of what is now universally called pelvic endometriosis.     

Decreased Progesterone Receptor B/A Ratio in Endometrial Cells by Tumor Necrosis Factor-Alpha and Peritoneal Fluid from Patients with Endometriosis

PurposeProgesterone resistance is thought to be a major factor that contributes to progression of endometriosis. However, it is not clear what causes progesterone resistance in endometriosis. This study aimed to assess whether cytokines or peritoneal fluid can affect progesterone receptor (PR) expression in endometrial cells and to verify whether PR expression is reduced in endometriosis.ResultsThe PR-B/A ratio was significantly decreased by treatment with either TNF-α (p=0.011) or peritoneal fluid from women with advanced-stage endometriosis (p=0.027). Immunoreactivity of PR-B expression was significantly lower during the secretory phase than during the proliferative phase in endometrial tissues from control subjects (p<0.001). PR-B expression was significantly reduced in the eutopic endometrium (p=0.031) and ovarian endometrioma (p=0.036) from women with advanced-stage endometriosis compared with eutopic endometrium tissues from control subjects.ConclusionProgesterone resistance in endometriosis may be caused by proinflammatory conditions in the pelvic peritoneal microenvironment.     

17β-雌二醇和二噁英对子宫内膜间质细胞表达趋化因子IL-8及其受体CXCR1的调控作用

解析内外环境因素对子宫内膜间质细胞表达IL-8及其自分泌作用的调控。采用免疫组化法比较子宫内膜异位症患者异位灶和在位内膜CXCR1翻译水平表达;流式细胞术分析17β-雌二醇和二噁英单独或联合作用对子宫内膜间质细胞表面CXCR1表达的调控作用;ELISA法分析17β-雌二醇和二噁英单独或联合作用对子宫内膜间质细胞分泌IL-8的影响。结果显示CXCR1在子宫内膜异位症患者异位灶组织高表达。17β-雌二醇和二噁英单独作用均抑制子宫内膜间质细胞表面CX-CR1的表达以及IL-8的分泌。二者联合作用能够上调CXCR1的表达,上调幅度与雌二醇浓度呈正相关;但进一步抑制了IL-8的分泌。雌激素与二噁英对子宫内膜间质细胞复合作用抑制其IL-8的分泌及其自分泌作用;子宫内膜异位症患者腹腔液高水平IL-8并非由内外雌激素样物质直接作用于异位灶子宫内膜间质细胞所致。     

Investigation of Matrix Metalloproteinase -1, 2 and tissue inhibitor of matrix metalloproteinases-1 in Endometriosis

Objective: To explore the role of matrix metalloproteinase-1,2 (MMP-1, MMP-2) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in endometriosis. Methods: The eutopic and ectopic endometria from 40 subjects suffering from endometriosis and regular.endometria from 40 subjects (excluding endometriosis) were collected and examined by in situ hybridization technology and western blot assay. Results: Both expressions of MMP-1 and -2 were stronger in ectopic endometrium and eutopic endometrium than in normal endometrium. On the contrary, the expression of TIMP-1 in ectopic endometrium and eutopic endometrium was lower. The differences were significant (P ＜ 0.01). Moreover, there was no relationship among the expressions of MMP-1, 2 and TIMP-1 in ectopic endometrium. Conclusion: The expressions of MMP-1, 2 and TIMP-1 lose balance and lack of periodic changes in ectopic endometrium , which explains the biological invasive behavior of endometriosis. It was suggested that regulating the balance between the MMPs and TIMP-1 should be an ideal therapeutic target to endometriosis.     

mRNA analysis of several components of the plasminogen activator and matrix metalloproteinase systems in endometriosis using a real-time quantitative RT-PCR assay

BACKGROUND: The plasminogen activator (PA) and matrix metalloproteinase (MMP) systems are implicated in the establishment of endometriosis. The mechanisms by which these systems are involved in the pathogenesis of this disease are not well defined and controversial results have been published. The aim of this study was to analyse mRNA and protein levels of several components of the PA and MMP systems in endometriotic tissue and endometrium from women with and without endometriosis. METHODS and RESULTS: Real-time quantitative RT-PCR assays were developed to quantify mRNA levels of these components in 57 women with endometriosis and 32 controls. Endometrium of women with endometriosis showed higher mRNA and antigenic levels of urokinase type-PA (uPA) and MMP-3 than endometrium from controls. In these patients, ovarian endometriotic tissue had higher mRNA and antigenic levels of PA inhibitor type 1 (PAI-1) and MMP inhibitor type 1 (TIMP-1) than endometrium. CONCLUSIONS: The increase in mRNA and protein levels of uPA and MMP-3 observed in endometrium of women with endometriosis may facilitate the attachment of endometrial tissue to the peritoneum and ovarian surface, as well as the invasion of the extracellular matrix. This process would lead to the formation of early endometriotic lesions. Once the ovarian endometriotic cyst is developed, PAI-1 and TIMP-1 would increase which could explain the frequent clinical finding of an endometrioma without invasion of the adjacent ovarian tissue.     

Endometrial cells from women with endometriosis have increased adhesion and proliferative capacity in response to extracellular matrix components: towards a mechanistic model for endometriosis progression

BACKGROUND: Endometriosis, classified as the presence of endometrial cells in ectopic sites, is a debilitating disease causing pain and infertility in approximately 10% of women of reproductive age. It is associated with the aberrant expression of extracellular matrix (ECM) components and their receptors, integrins. METHODS: We analysed the expression of integrins in stromal cells derived from peritoneal, ovarian and deeply infiltrating endometriotic lesions and from endometrium from women with and without endometriosis in vitro, using quantitative immunocytochemistry. The adhesive and proliferative capacity of each of the cell types in response to ECM components was assessed by in vitro assays of cell attachment and DNA synthesis. RESULTS: We demonstrate that eutopic and ectopic endometrial stromal cells from women with endometriosis exhibit an aberrant integrin profile in vitro compared with stromal cells derived from healthy controls. In addition, the former display increased adhesion and proliferative capacity in response to specific ECM components. CONCLUSIONS: We propose that the increased adhesive and proliferative potential of cells from endometriotic lesions may be a key feature in the pathogenesis of endometriosis. Furthermore, the elevated responsiveness of eutopic cells from women with endometriosis may contribute to the predisposition of some women to the disease.     

Ovarian steroid receptor expression in endometriosis and in two potential parent epithelia: endometrium and peritoneal mesothelium.

Endometriosis is an oestrogen dependent condition and it is expected that the tissue of origin of endometriosis will express receptors for the ovarian steroids. Two epithelia, endometrium and peritoneal mesothelium, are the potential parent epithelium. Oestrogen and progesterone receptor expression has been studied immunohistochemically in (i) timed endometrial biopsies from 25 normal subjects and 27 patients with endometriosis, (ii) 25 endometriotic biopsies and (iii) 42 peritoneal biopsies. Endometrium but not peritoneal mesothelium expresses both oestrogen and progesterone receptors. No difference in the intensity of staining between endometria of normal subjects compared with the endometria of patients with endometriosis was noted. In paired endometrial and endometriotic biopsies, the intensity of staining for the oestrogen receptor in stromal cells and for the progesterone receptor in both glandular and stromal cells was less in the endometriotic biopsies. These data provide circumstantial evidence for an endometrial origin for endometriosis although quantitative differences exist in receptor expression between endometrium and endometriosis.     

Expression of interleukin-8 receptors in endometriosis

BACKGROUND: Although the etiology of endometriosis is not well understood, chemokines and their receptors are believed to play a role in its pathogenesis. Therefore, we aimed to investigate the expression and localization of interleukin-8 (IL-8) receptors CXCR1 and CXCR2 in eutopic and ectopic endometrial tissues of women with endometriosis, and in endometrium of women without endometriosis. METHODS: Ectopic (n = 27) and homologous eutopic endometrium (n = 25) from women with endometriosis and endometrium from women without endometriosis (n = 27) were used for immunohistochemical analysis of CXCR1 and CXCR2. RESULTS: In normal endometrium, epithelial CXCR1 and CXCR2 immunostaining intensities were similar in the proliferative and secretory phase. Stromal CXCR1 expression was less then epithelial expression and did not show cyclical difference. No stromal CXCR2 expression was observed. In eutopic endometrium of women with endometriosis compared to endometrium of women without endometriosis, there was a significant increase in both proliferative and secretory phases for epithelial CXCR2 expression, and in proliferative phase for CXCR1 expression (P < 0.05). Both receptor immunoreactivities were significantly increased in the epithelial cells of ectopic endometrial tissues compared to that of normal endometrium (P < 0.05). CONCLUSIONS: These findings suggest that IL-8 and its receptors may be involved in the pathogenesis of endometriosis.     

Eutopic endometrium and peritoneal,ovarian and bowel endometriotic tissues express a different profile of matrix metalloproteinases-2, -3 and -11, and of tissue inhibitor metalloproteinases-1 and -2

Endometriosis is subsequent to the ability of endometrial glands to invade normal tissues. Matrix metalloproteinases (MMPs)—enzymes that mediate normal tissue turnover, including endometrial breakdown during menstruation—appear to be involved in this invasive process. Here, we examined the immunohistochemical expression of MMP-2, MMP-3, MMP-11, tissue inhibitor metalloproteinase (TIMP)-1 and TIMP-2 in endometrium from women with (n=9) or without endometriosis (n=18) in comparison with peritoneal (n=20), ovarian (n=20) and colorectal endometriosis (n=20). Women with endometriosis showed decreased endometrial MMP-2 expression compared with women without endometriosis (mean±SD positive cells: 24.3±28.3% and 69.3±12.1%), together with loss of MMP-3 expression (0 versus 17.5%±20.2). MMP-11, TIMP-1 and TIMP-2 expression was similar in the two groups. Endometrial MMP-2, -3 and -11 expression and TIMP-1 and -2 expression were similar in women with endometriosis and in those with peritoneal endometriosis. MMP-2, -3 and -11 expression was higher in colorectal endometriosis than in ovarian and peritoneal endometriosis. TIMP-2 expression was lower in colorectal endometriosis (P=0.0002) and ovarian endometriotic cysts (P=0.003) than in peritoneal endometriosis. TIMP-1 expression did not vary according to the location of endometriotic lesions. These results suggest that MMP-2 and -3 and TIMP-2 may be involved in the pathogenesis of endometriosis. Interestingly, MMP-2 and -3 overexpression was related to the infiltrative nature of endometriotic lesions, with possible sequential expression from peritoneal to colorectal endometriosis.