Hepatocyte growth factor may be involved in cellular changes to the peritoneal mesothelium adjacent to pelvic endometriosis

The role of innate and adaptive immunity in endometriosis

The innate and adaptive immune systems are the two key branches that determine host protection at all mucosal surfaces in human body, including the female reproductive tract. The pattern recognition receptors within the host that recognize pathogen-associated molecular patterns are expressed on the cells of the innate immune system. Rapidly reactive, theinnate immune system, responds immediately to the presence of infectious or other non-self agents, thereby launching an inflammatory response to protect the host until the activation of slower adaptive immune system. Macrophages, dendritic cells, and toll-like receptors are integral components of the innate immune system. In contrast, T-helper (Th1/Th2/Th17) cells and regulatory T (Treg) cells are the primary components of adaptive immune system. Studies showed that the growth and progression of endometriosis continue even in unilateral ovariectomized animal suggesting that besides ovarian steroid hormones, the growth of endometriosis could be regulated by innate/adaptive immune systems in pelvic environment. Recent reports demonstrated a potential role of Th1/Th2/Th17/Treg cells either individually or collectively in the initiation, maintenance, and progression of endometriosis. Herewe review the fundamental knowledge of innate and adaptive immunity and elaborate the role of innate and adaptive immunity in endometriosis based on both human and experimental data.

Mesothelial Cells Participate in Endometriosis Fibrogenesis Through Platelet-Induced Mesothelial-Mesenchymal Transition

CONTEXT

While fibrosis in endometriosis has recently loomed prominently, the sources of myofibroblasts, the principal effector cell in fibrotic diseases, remain largely obscure. Mesothelial cells (MCs) can be converted into myofibroblasts through mesothelial-mesenchymal transition (MMT) in many fibrotic diseases and adhesion.

OBJECTIVE

To evaluate whether MCs contribute to the progression and fibrogenesis in endometriosis through MMT.

SETTING, DESIGN, PATIENTS, INTERVENTION, AND MAIN OUTCOME MEASURES

Dual immunofluorescence staining and immunohistochemistry using antibodies against calretinin, Wilms' tumor-1 (WT-1), and α-smooth muscle actin (α-SMA) were performed on lesion samples from 30 patients each with ovarian endometrioma (OE) and deep endometriosis (DE), and 30 normal endometrial (NE) tissue samples. Human pleural and peritoneal MCs were co-cultured with activated platelets or control medium with and without neutralization of transforming growth factor β1 (TGF-β1) and/or platelet-derived growth factor receptor (PDGFR) and their morphology, proliferation, and expression levels of genes and proteins known to be involved in MMT were evaluated, along with their migratory and invasive propensity, contractility, and collagen production.

RESULTS

The number of calretinin/WT-1 and α-SMA dual-positive fibroblasts in OE/DE lesions was significantly higher than NE samples. The extent of lesional fibrosis correlated positively with the lesional α-SMA staining levels. Human MCs co-cultured with activated platelets acquire a morphology suggestive of MMT, concomitant with increased proliferation, loss of calretinin expression, and marked increase in expression of mesenchymal markers. These changes coincided with functional differentiation as reflected by increased migratory and invasive capacity, contractility, and collagen production. Neutralization of TGF-β1 and PDGFR signaling abolished platelet-induced MMT in MCs.

CONCLUSIONS

MCs contribute to lesional progression and fibrosis through platelet-induced MMT.

INC280, an orally available small molecule inhibitor of c-MET, reduces migration and adhesion in ovarian cancer cell models

5-year survival rates for ovarian cancer are approximately 40%, and for women diagnosed at late stage (the majority), just 27%. This indicates a dire need for new treatments to improve survival rates. Recent molecular characterization has greatly improved our understanding of the disease and allowed the identification of potential new targets. One such pathway of interest is the HGF/c-MET axis. Activation of the HGF/c-MET axis has been demonstrated in certain ovarian tumours, and been found to be associated with decreased overall survival, suggesting its potential as a therapeutic target. The objective of this study was to determine the efficacy of a novel, highly potent, orally-bioavailable c-MET inhibitor, INC280, in blocking cell phenotypes important in ovarian cancer metastasis. Using in vitro and ex vivo models, we demonstrate that INC280 inhibits HGF-induced c-MET, and reduces downstream signalling. HGF-stimulated chemotactic and random migration are decreased by INC280 treatment, to levels seen in non-stimulated cells. Additionally, HGF-induced adhesion of cancer cells to peritoneal tissue is significantly decreased by INC280 treatment. Overall, these data indicate that INC280 inhibits many cell behaviours that promote ovarian cancer metastasis, and merits further investigation as a therapeutic candidate in the treatment of patients with ovarian cancer.

Decreased expression of human heat shock protein 70 in the endometria and pathological lesions of women with adenomyosis and uterine myoma after GnRH agonist therapy

OBJECTIVE

A prominent stress reaction in the pelvis of women with endometriosis and the role of human heat shock protein 70 (HSP70) in inflammation and the growth of endometriosis has been recently demonstrated. We report here expression of HSP70 in tissues derived from GnRH agonist (GnRHa)-untreated and -treated women with adenomyosis and uterine myoma.

STUDY DESIGN

This is a case-controlled biological study. Biopsy specimens were collected from pathological lesions and eutopic endometria/autologous myometria of 30 women with adenomyosis, 35 women with uterine myoma and 15 control women during laparoscopy, laparotomy and hysteroscopy. Fourteen women with adenomyosis and 20 women with uterine myoma were treated with GnRHa for a variable period of 3-6 months before surgery. The immunoexpressions of HSP70 and CD68-positive Mϕ in endometria, lesions/myometria were examined by immunohistochemistry. The immunoreactivity of HSP70 in tissues was analyzed by quantitative-histogram (Q-H) scores.

RESULTS

Comparing to control women, HSP70 immunoexpression was significantly higher in endometria/myometria and pathological lesions of women with adenomyosis and myoma. A significant positive correlation between Q-H scores of HSP70 and CD68-positive Mϕ numbers was found in the endometria derived from women with adenomyosis (r=0.388). Treatment with GnRHa significantly decreased Q-H scores of HSP70 in pathological lesions and endometria/myometria of women with adenomyosis and uterine myoma comparing to similar tissues derived from GnRHa-untreated women.

CONCLUSION

A variable amount of tissue stress reaction occurred in endometria and pathological lesions of women adenomyosis and uterine myoma that can be effectively suppressed after GnRHa treatment.

The peritoneum is both a source and target of TGF-β in women with endometriosis

Transforming growth factor-β (TGF-β) is believed to play a major role in the aetiology of peritoneal endometriosis. We aimed to determine if the peritoneum is a source of TGF-β and if peritoneal TGF-β expression, reception or target genes are altered in women with endometriosis. Peritoneal fluid, peritoneal bushings and peritoneal biopsies were collected from women with and without endometriosis. TGF-β1, 2 and 3 protein concentrations were measured in the peritoneal fluid. TGF-β1 was measured in mesothelial cell conditioned media. Control peritoneum and peritoneum prone to endometriosis (within Pouch of Douglas) from women without disease (n = 16) and peritoneum distal and adjacent to endometriosis lesions in women with endometriosis (n = 15) and were analysed for TGF-β expression, reception and signalling by immunohistochemistry, qRT-PCR and a TGF-β signalling PCR array. TGF-β1 was increased in the peritoneal fluid of women with endometriosis compared to those without disease (P<0.05) and peritoneal mesothelial cells secrete TGF-β1 in-vitro. In women with endometriosis, peritoneum from sites adjacent to endometriosis lesions expressed higher levels of TGFB1 mRNA when compared to distal sites (P<0.05). The TGF-β-stimulated Smad 2/3 signalling pathway was active in the peritoneum and there were significant increases (P<0.05) in expression of genes associated with tumorigenesis (MAPK8, CDC6), epithelial-mesenchymal transition (NOTCH1), angiogenesis (ID1, ID3) and neurogenesis (CREB1) in the peritoneum of women with endometriosis. In conclusion, the peritoneum, and in particular, the peritoneal mesothelium, is a source of TGF-β1 and this is enhanced around endometriosis lesions. The expression of TGF-β-regulated genes is altered in the peritoneum of women with endometriosis and this may promote an environment favorable to lesion formation.

Occult microscopic endometriosis: undetectable by laparoscopy in normal peritoneum

STUDY QUESTION

Is there any occurrence of hidden (occult) endometriotic lesions in normal peritoneum of women with and without visible endometriosis?

SUMMARY ANSWER

We detected a slightly higher occurrence of occult microscopic endometriosis (OME) in normal peritoneum of women with visible endometriosis than in control women.

WHAT IS KNOWN ALREADY

Based on a small number of cases, the concept of invisible microscopic endometriosis in visually normal peritoneum has been reported for more than a decade but there is controversy regarding their tissue activity and clinical significance.

STUDY DESIGN, SIZE, DURATION

This case-controlled research study was conducted with prospectively collected normal peritoneal samples from 151 women with and 62 women without visible endometriosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Normal peritoneal biopsy specimens from different pelvic sites of were collected during laparoscopy. A histological search of all peritoneal biopsy specimens for the detection of invisible endometriosis was done by immunoreaction to Ber-EP4 (epithelial cell marker), CD10 (stromal cell marker) and Calretinin (mesothelial cell marker). Tissue expression of estrogen/progesterone receptors (ER/PR) and cell proliferation marker, Ki-67, was performed by immunohistochemistry to identify tissue activity.

MAIN RESULTS AND THE ROLE OF CHANCE

Three different patterns of OME were detected based on (I) the presence of typical gland/stroma, (II) reactive hyperplastic change of endometrioid epithelial cells with surrounding stroma and (III) single-layered epithelium-lined cystic lesions with surrounding stroma. A higher tendency toward the occurrence of OME was found in women with visible endometriosis (15.2%, 23/151) compared with control women (6.4%, 4/62) (P = 0.06, χ(2) test). The epithelial cells and/or stromal cells of OME lesions were immunoreactive to Ber-EP4 and CD10 but not reactive to Calretinin. ER and PR expression was observed in all patterns of OME lesions. Ki-67 index was significantly higher in pattern I/II OME lesions than in pattern III OME lesions (P< 0.05 for each).

LIMITATIONS, REASONS FOR CAUTION

Bias in the incidence rate of OME lesions in this study cannot be ignored, because we could not analyze biopsy specimens from the Pouch of Douglas of women with revised classification of the American Society of Reproductive Medicine Stage III-IV endometriosis due to the presence of adhesions in the pelvis.

WIDER IMPLICATIONS OF THE FINDINGS

We re-confirmed a decade long old concept of invisible (occult) endometriosis in visually normal peritoneum of women with visible endometriosis. The existence of a variable amount of tissue activity in these occult lesions may contribute to the recurrence/occurrence of endometriosis or persistence/recurrence of pain manifestation in women even after successful ablation or excision of visible lesions by laparoscopy.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by Grants-in-aid for Scientific Research from the Japan Society for the Promotion of Science. There is no conflict of interest related to this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Pelvic pain in women with ovarian endometrioma is mostly associated with coexisting peritoneal lesions

STUDY QUESTION

Is the occurrence of pelvic pain in women with ovarian endometrioma associated with coexisting peritoneal lesions (PLs)?

SUMMARY ANSWER

Pelvic pain in women with ovarian endometrioma is usually associated with coexisting PLs. An increased tissue inflammatory reaction with elevated prostaglandin (PG) production may be responsible for the generation of pain.

WHAT IS KNOWN ALREADY

Severe pelvic pain in women with ovarian endometrioma is reported to be associated with deeply infiltrating endometriosis. However, information on pelvic pain in women with ovarian endometriosis with and without coexistent peritoneal superficial lesions is limited.

STUDY DESIGN, SIZE AND DURATION

Retrospective clinical study with case-controlled biological research using prospectively collected tissue samples derived from women with and without endometriosis and their retrospective evaluation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed a retrospective cohort study conducted in 2988 cases who had laparoscopic surgery for indications of ectopic pregnancy, tubal infertility and other benign gynecologic diseases. We analyzed the occurrence of pelvic pain in the cases with ovarian endometrioma according to the distribution of coexisting PLs and pattern of intrapelvic adhesions. Inflammatory reaction of eutopic and ectopic endometria was measured by immunoreaction to macrophage marker, CD68. The tissue expression of cyclooxygenase (COX) 2 was examined by immunohistochemistry and tissue concentrations of PG F2α were measured by ELISA.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 2988 surgical cases, 350 (11.7%) were found to have ovarian endometrioma at laparoscopy. Coexisting PLs were present in 269 of these women and in this group 85.4% of cases experienced pelvic pain and 14.6% had no pain. In contrast, among the 81 women with ovarian endometrioma only, 38.3% cases experienced pelvic pain and 61.7% cases had no pain and the difference between the groups was statistically significant (P < 0.01). The infiltration of CD68-immunoreactive macrophages was significantly higher in the eutopic and ectopic endometria of women with peritoneal endometriosis than in ovarian endometrioma. The tissue expression of COX2 and levels of PGF2α were significantly higher in both the eutopic and ectopic endometria derived from women with peritoneal endometriosis than in similar tissues derived from women with ovarian endometrioma.

LIMITATIONS, REASONS FOR CAUTIONS

Lack of evaluation in the detection of general or disseminated deeply infiltrating endometriosis in the pelvic cavity could be a bias or limitation in this study. Further multicenter prospective studies are needed to strengthen our current findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings may provide some new insights to understand the physiopathology of pelvic pain in women with ovarian cystic endometriosis and may hint at proper surgical manipulation to prevent the recurrence of pelvic pain in these women.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Sports, Culture, Science and Technology of Japan. There is no conflict of interest related to this study.

TRIAL REGISTRATION NUMBER

Not applicable.

Evaluation of endometrial biomarkers for semi-invasive diagnosis of endometriosis

OBJECTIVE

To test the hypothesis that specific proteins and peptides are expressed differentially in eutopic endometrium of women with and without endometriosis and at specific stages of the disease (minimal, mild, moderate, or severe) during the secretory phase.

DESIGN

Patients with endometriosis were compared with controls.

SETTING

University hospital.

PATIENT(S)

A total of 29 patients during the secretory phase were selected for this study on the basis of cycle phase and presence or absence of endometriosis.

INTERVENTION(S)

Endometriosis was confirmed laparoscopically and histologically in 19 patients with endometriosis of revised American Society for Reproductive Medicine stages (9 minimal-mild and 10 moderate-severe), and the presence of a normal pelvis was documented by laparoscopy in 10 controls.

MAIN OUTCOME MEASURE(S)

Protein expression of endometrium was evaluated with use of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. The differential expression of protein mass peaks was analyzed with use of support vector machine algorithms and logistic regression models.

RESULT(S)

Data preprocessing resulted in differential expression of 73, 30, and 131 mass peaks between controls and patients with endometriosis (all stages), with minimal-mild endometriosis, and with moderate-severe endometriosis, respectively. Endometriosis was diagnosed with high sensitivity (89.5%) and specificity (90%) with use of five down-regulated mass peaks (1.949 kDa, 5.183 kDa, 8.650 kDa, 8.659 kDa, and 13.910 kDa) obtained after support vector machine ranking and logistic regression classification. With use of a similar analysis, minimal-mild endometriosis was diagnosed with four mass peaks (two up-regulated: 35.956 kDa and 90.675 kDa and two down-regulated: 1.924 kDa and 2.504 kDa) with maximal sensitivity (100%) and specificity (100%). The 90.675-kDa and 35.956-kDa mass peaks were identified as T-plastin and annexin V, respectively.

CONCLUSION(S)

Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry analysis of secretory phase endometrium combined with bioinformatics puts forward a prospective panel of potential biomarkers with sensitivity of 100% and specificity of 100% for the diagnosis of minimal to mild endometriosis.

Immunopathogenesis of pelvic endometriosis: role of hepatocyte growth factor, macrophages and ovarian steroids

Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology of endometriosis is still elusive. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by innate immune system in pelvic microenvironment by their interaction with endometrial cells and immune cells. We conducted a series of studies in perspectives of pelvic inflammation that is triggered primarily by bacterial endotoxin (lipopolysaccharide) and is mediated by toll-like receptor 4 and showed their involvement in the development of pelvic endometriosis. As a cellular component of innate immune system, macrophages were found to play a central role in inducing pelvic inflammatory reaction. We further report here that peritoneal macrophages retain receptors encoding for estrogen and progesterone and ovarian steroids also participate in producing an inflammatory response in pelvic cavity and are involved in the growth of endometriosis either alone or in combination with hepatocyte growth factor (HGF). As a pleiotropic growth factor, HGF retains multifunctional role ometriosis. We describe here the individual and step-wise role of HGF, macrophages and ovarian steroid hormones and their orchestrated involvement in the immunopathogenesis of pelvic endometriosis.

Targeting mast cells in endometriosis with janus kinase 3 inhibitor, JANEX-1

Endometriosis (EMS) is a chronic inflammatory disease of multifactorial etiology characterized by implantation and growth of endometrial glands and stroma outside the uterine cavity. EMS is a significant public health issue as it affects 15-20% of women in their reproductive age. Clinical symptoms may include pelvic pain, dysmenorrhea, dyspareunia, pelvic/abdominal masses, and infertility. Symptomatic treatments such as surgical resection and/or hormonal suppression of ovarian function and analgesics are not as effective as desired. Consequently, there is an enormous unmet need to develop effective medical therapy capable of preventing the occurrence and recurrence of EMS without undesirable side-effects. EMS-associated intra-abdominal bleeding episodes, local inflammation, adhesions, and i.p. immunologic dysfunction leads to pelvic nociception and pelvic pain. Increasing evidence supports the involvement of allergic-type inflammation in EMS. Invasion of mast cells, degranulation, and proliferation of interstitial component are observed in endometriotic lesions. Presence of activated and degranulating mast cells within the nerve structures can contribute to the development of pain and hyperalgesia by direct effects on primary nociceptive neurons. Therefore, treatments targeting endometrial mast cells may prove effective in preventing or alleviating EMS-associated symptoms. The Janus kinase 3 (JAK3) is abundantly expressed in mast cells and is required for the full expression of high-affinity IgE receptor-mediated mast cell inflammatory sequelae. JANEX-1/WHI-P131 is a rationally designed novel JAK3 inhibitor with potent anti-inflammatory activity in several cellular and in vivo animal models of inflammation, including mouse models of peritonitis, colitis, cellulitis, sunburn, and airway inflammation with favorable toxicity and pharmacokinetic profile. We hypothesize that JAK3 inhibitors, especially JANEX-1, may prove useful to prevent or alleviate the symptoms of EMS.

Differential infiltration of macrophages and prostaglandin production by different uterine leiomyomas

BACKGROUND

The association between uterine myoma and infertility is still controversial. The anatomical defect of endometrium by uterine fibroids could be a factor for reducing pregnancy rates and increasing miscarriage rates. However, pregnancy and implantation rates were found to be significantly lower in women with intramural myomas (IMMs), when there was no deformity of uterine cavity. This could be due to other biological factors such as increased accumulation of inflammatory cells within fibroid tissue and corresponding endometrium that might impair fertility. Therefore, we tried to investigate the pattern of macrophage (Mvarphi) accumulation in different uterine fibroids and the production of chemokine and prostaglandin (PG) by these tissues.

METHODS

The selection criteria of uterine fibroids were based on the classification of European Society of Hysteroscopy. Biopsy specimens were collected from respective nodules and autologous endometrium of 20 women with submucosal myoma (SMM), 29 women with IMM and 18 women with subserosal myoma (SSM). CD68 immunoreactive Mvarphis were identified in these tissues by immunohistochemistry. A fraction of corresponding tissues were homogenized, and levels of monocyte chemotactic protein-1 (MCP-1) and PGF(2alpha) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Mvarphi infiltration in the myoma nodule and corresponding endometrium of women with SMM and IMM was significantly higher than that of women with SSM or control women (P<0.01 and P<0.05, respectively). This tissue accumulation of inflammatory cells was independent of the sizes of the myoma nodules and phases of menstrual cycle. The tissue concentration of MCP-1 corresponded to increased Mvarphi infiltration and was significantly higher in women with SMM and IMM than that in women with SSM (P<0.05 for each). A positive correlation was observed between MCP-1 concentration and accumulated Mvarphi numbers in the endometrium of women with SMM and IMM but not in women with SSM. The tissue levels of PGF2alpha were also significantly higher in the nodule and corresponding endometrium of women with SMM and IMM than that in SSM or control women (P<0.05 for each).

CONCLUSIONS

Higher production of MCP-1 could be responsible for the increased accumulation of Mvarphi in women with SMM and IMM. The augmented inflammatory reaction in endometrium and increased PGF2alpha levels might be detrimental to reproductive outcome in women with SMM or IMM.

Interleukin-6- and tumour necrosis factor alpha-mediated expression of hepatocyte growth factor by stromal cells and its involvement in the growth of endometriosis

BACKGROUND

We investigated the expression of the hepatocyte growth factor (HGF) gene and protein by the stromal cells derived from women with or without endometriosis and its regulation by interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFalpha).

METHODS

Stromal cells immunoreactive to vimentin were isolated from the eutopic and ectopic endometrium of 18 infertile women with endometriosis and 12 women without endometriosis. The production of HGF in the culture media of basal and IL-6- or TNFalpha-stimulated stromal cells was examined with an enzyme-linked immunosorbent assay. The mRNA expression of HGF and its receptor c-Met in the stroma was investigated by RT-PCR. The localization of HGF and c-Met in isolated stromal cells and in intact tissue was examined by immunohistochemistry. The effect of HGF on the growth of stromal cells alone or in combination with IL-6 or TNFalpha was examined in a bromodeoxyuridine (BrdU) incorporation study.

RESULTS

The production of HGF in the culture medium of stromal cells was significantly increased after single or combined treatment with either IL-6 or TNFalpha when compared with non-treated cells. The production of HGF by stromal cells derived from the eutopic endometrium of women with endometriosis was significantly higher than that of cells from women without endometriosis. This effect was paralleled by increased expression of HGF and c-Met mRNA, as demonstrated by RT-PCR. The BrdU incorporation study indicated that the addition of HGF enhanced the growth of endometrial and endometriotic stroma alone or in combination with IL-6 or TNFalpha.

CONCLUSION

IL-6 and TNFalpha are involved in the production of HGF by endometrial stromal cells and may be involved in the growth of endometriosis by an autocrine mechanism.

Regulation of hepatocyte growth factor by basal and stimulated macrophages in women with endometriosis

BACKGROUND

The different macromolecules as secreted by macrophages in the pelvic environment are believed to enhance the growth of endometriosis. However, the possible mediator that stimulates macrophages for the production of different growth factors is not well described. Therefore, we investigated the possible production of hepatocyte growth factor (HGF) by the basal and lipopolysaccharide (LPS)-stimulated macrophages derived from women with or without endometriosis.

METHODS

Using primary culture and 4-well chamber slides, adherent macrophages immunoreactive to CD68 were isolated from the peritoneal fluid (PF) of 20 infertile women with endometriosis and 12 women without endometriosis. The proliferation of basal and LPS-treated macrophages was investigated by the dimethylthiazole tetrazolioum bromide (MTT) assay. The production of HGF in the culture media of basal and LPS-stimulated macrophages was examined by enzyme-linked immunosorbent assay. The expression of mRNA for HGF and its receptor, c-Met, in the macrophages was investigated by RT-PCR. The effect of HGF on the growth of endometrial cells and macrophages was analysed by bromodeoxyuridine (BrdU) incorporation.

RESULTS

A >100% increase in the proliferation of peritoneal macrophages derived from women with endometriosis, and particularly of those harbouring dominant red lesions, was observed after treatment with LPS (P<0.05). A 4- and 3-fold increase in the production of HGF was observed by the LPS-treated macrophages derived from women with stage I-II endometriosis and stage III-IV endometriosis, respectively, when compared with non-LPS-treated macrophages (P<0.001). At the transcriptional level, we found a 5-fold increase in HGF mRNA expression in LPS-treated macrophages versus basal macrophages in women with endometriosis (P<0.001). The BrdU incorporation study indicates that 10-100 ng/ml of HGF enhanced the growth of endometrial epithelial cells, stroma and macrophages (approximately 50% increase) derived from women with endometriosis (all P<0.05).

CONCLUSION

LPS could be an inflammatory mediator of macrophage stimulation in the pelvic microenvironment. Besides mesenchymal cells, HGF is also produced by peritoneal macrophages and is possibly involved in the growth of endometriosis.

Estrogen and progesterone receptor expression in macrophages and regulation of hepatocyte growth factor by ovarian steroids in women with endometriosis

BACKGROUND

Information regarding macrophage-mediated regulation of hepatocyte growth factor (HGF) by ovarian steroid hormones in women with endometriosis is limited. Therefore, we investigated the regulation of HGF by steroid hormones in isolated macrophages and stromal cells derived from women with or without endometriosis.

METHODS

We isolated CD68 immunoreactive adherent macrophages in vitro from 46 women with endometriosis and 30 women without endometriosis. Estrogen receptor (ER) and progesterone receptor (PR) expression in macrophages was demonstrated by immunohistochemistry and RT-PCR. Production of HGF in the culture media of basal and ovarian steroid-stimulated macrophages was examined by enzyme-linked immunosorbent assay. Expression of mRNA for HGF and its receptor, c-Met in macrophages and stromal cells in response to ovarian steroid was investigated by RT-PCR. The single and combined effect of HGF and estrogen on the growth of macrophages and stromal cells was analysed by bromodeoxyuridine (BrdU) incorporation.

RESULTS

ER and PR were expressed in isolated macrophages and intact tissue at the protein and mRNA levels. Macrophages derived from women with endometriosis produced significantly higher concentration of HGF (352.2 +/- 4.9 pg/ml) in conditioned media after treatment with estradiol (10(-8) mol/l) than that of basal macrophages (221.5 +/- 32.8 pg/ml, P<0.05) or women without endometriosis (170.6 +/- 2.6 pg/ml, P<0.05). These effects were less evident after treatment with progesterone. Treatment with tamoxifen (10(-6) mol/l) reversed the production of HGF and other macromolecules. Secretion of HGF in response to ovarian steroids was further enhanced after activation with lipopolysaccharide. The mRNA expressions of HGF and its receptor, c-Met, were also detected in macrophages and stroma in response to estrogen, suggesting an autocrine regulation. HGF mRNA expression was higher in cells of women with endometriosis than non-endometriosis women. Bromodeoxyuridine incorporation indicated that exogenous stimulation with HGF and estrogen, either alone or in combination, significantly increased the cell proliferation of both endometrial stroma and macrophages compared to that of non-endometriosis or non-treated cells.

CONCLUSION

These results suggest that besides other inflammatory mediators, ovarian steroids also participate in the production of HGF by peritoneal macrophages which may be involved in the growth of endometriosis either alone or in combination with estrogen.