The ellagic acid metabolites urolithin A and B differentially affect growth, adhesion, motility, and invasion of endometriotic cells in vitro.

STUDY QUESTION: What are the effects of plant-derived antioxidant compounds urolithin A (UA) and B (UB) on the growth and pathogenetic properties of an in vitro endometriosis model? SUMMARY ANSWER: Both urolithins showed inhibitory effects on cell behavior related to the development of endometriosis by differentially affecting growth, adhesion, motility, and invasion of endometriotic cells in vitro. WHAT IS KNOWN ALREADY: Endometriosis is one of the most common benign gynecological diseases in women of reproductive age and is defined by the presence of endometrial tissue outside the uterine cavity. As current pharmacological therapies are associated with side effects interfering with fertility, we aimed at finding alternative therapeutics using natural compounds that can be administered for prolonged periods with a favorable side effects profile. STUDY DESIGN, SIZE, DURATION: In vitro cultures of primary endometriotic stromal cells from 6 patients subjected to laparoscopy for benign pathologies with histologically confirmed endometriosis; and immortalized endometrial stromal (St-T1b) and endometriotic epithelial cells (12Z) were utilized to assess the effects of UA and UB on endometriotic cell properties. Results were validated in three-dimensional (3D) in vitro co-culture spheroids of 12Z and primary endometriotic stroma cells of one patient, and organoids from 3 independent donors with endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The effects on cell growth were measured by non-radioactive colorimetric assay to measure cellular metabolic activity as an indicator of cell viability (MTT assay) and flow cytometric cell cycle assay on primary cultures, St-T1b, and 12Z. Apoptosis analyses, the impact on in vitro adhesion, migration, and invasion were evaluated in the cell lines. Moreover, Real-Time Quantitative Reverse Transcription polymerase chain reaction (RT-qPCR) assays were performed on primary cultures, St- T1b and 12Z to evaluate a plausible mechanistic contribution by factors related to proteolysis (matrix metalloproteinase 2, 3 and 9 -MMP2, MMP3, MMP9-, and tissue inhibitor of metalloproteinases -TIMP-1-), cytoskeletal regulators (Ras-related C3 botulinum toxin substrate 1 -RAC1-, Rho-associated coiled-coil containing protein kinase 2 -ROCK2-), and cell adhesion molecules (Syndecan 1 -SDC1-, Integrin alpha V-ITGAV-). Finally, the urolithins effects were evaluated on spheroids and organoids by formation, viability, and drug screen assays. MAIN RESULTS AND THE ROLE OF CHANCE: 40 µM UA and 20 µM UB produced a significant decrease in cell proliferation in the primary endometriotic cell cultures (P < 0.001 and P < 0.01, respectively) and in the St-T1b cell line (P < 0.001 and P < 0.05, respectively). In St-T1b, UA exhibited a mean half-maximum inhibitory concentration (IC50) of 39.88 µM, while UB exhibited a mean IC50 of 79.92 µM. Both 40 µM UA and 20 µM UB produced an increase in cells in the S phase of the cell cycle (P < 0.01 and P < 0.05, respectively). The same concentration of UA also increased the percentage of apoptotic ST-t1b cells (P < 0.05), while both urolithins decreased cell migration after 24 h (P < 0.001 both). Only the addition of 5 µM UB decreased the number of St-T1b adherent cells. TIMP-1 expression was upregulated in response to treating the cells with 40 µM UA (P < 0.05). Regarding the 12Z endometriotic cell line, only 40 µM UA decreased proliferation (P < 0.01); while both 40 µM UA and 20 µM UB produced an increase in cells in the G2/M phase (P < 0.05 and P < 0.01, respectively). In this cell line, UA exhibited a mean IC50 of 40.46 µM, while UB exhibited a mean IC50 of 54.79 µM. UB decreased cell migration (P < 0.05), and decreased the number of adherent cells (P < 0.05). Both 40 µM UA and 20 µM UB significantly decreased the cellular invasion of these cells; and several genes were altered when treating the cells with 40 µM UA and 10 µM UB. The expression of MMP2 was downregulated by UA (P < 0.001), and expression of MMP3 (UA P < 0.001 and UB P < 0.05) and MMP9 (P < 0.05, both) were downregulated by both urolithins. Moreover, UA significantly downregulated ROCK2 (P < 0.05), whereas UB treatment was associated with RAC1 downregulation (P < 0.05). Finally, the matrix adhesion receptors and signaling (co)receptors SDC1 and ITGAV were downregulated upon treatment with either UA or UB (P < 0.01 and P < 0.05, respectively in both cases). Regarding the effects of urolithins on 3D models, we have seen that they significantly decrease the viability of endometriosis spheroids (80 µM UA and UB: P < 0.05 both) as well as affecting their area (40 µM UA: P < 0.05, and 80 µM UA: P < 0.01) and integrity (40 µM UA and UB: P < 0.05, 80 µM UA and UB: P < 0.01). On the other hand, UA and UB significantly inhibited organoid development/outgrowth (40 and 80 µM UA: P < 0.0001 both; 40 µM UB: P < ns-0.05-0.001, and 80 µM UB: P < 0.01-0.001-0.001), and all organoid lines show urolithins sensitivity resulting in decreasing viability (UA exhibited a mean IC50 of 33.93 µM, while UB exhibited a mean IC50 of 52.60 µM). LARGE-SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: This study was performed on in vitro endometriosis models. WIDER IMPLICATIONS OF THE FINDINGS: These in vitro results provide new insights into the pathogenetic pathways affected by these compounds and mark their use as a potential new therapeutic strategy for the treatment of endometriosis. STUDY FUNDING/COMPETING INTEREST(S): This study was funded EU MSCA-RISE-2015 project MOMENDO (691058). The authors have no conflicts of interest to declare.

Reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55 deficient mice.

Endometriosis is a chronic gynecological disease, characterized by growth of endometrial tissue in ectopic sites due to alteration of peritoneal homeostasis and deregulation of apoptosis. Here we have examined whether TNFRp55 deficiency modulates the pro-inflammatory state and the reinnervation of endometriotic-like lesions in mice. Two-month-old female C57BL/6 mice, eight wild type (WT) and eight TNFRp55-/- (KO) were used in the study. Endometriotic-like lesions were induced experimentally. The right uterine horn was removed from the animal, divided longitudinally, cut in three square pieces and sutured to the intestine mesentery. After 4 weeks, the lesions and the peritoneal fluid were collected. The level of TNFα in the peritoneal fluid was evaluated by enzyme-linked immunosorbent assay (EIA). The expressions of COX2, GRα and GRß were evaluated in the lesions by western blot and immunohistochemistry. ß-III TUBULIN, BDNF and NGF protein concentrations were evaluated in the lesions by western blot. Gene expression of Pgp 9.5, SP and Th was analyzed by RT-PCR, whereas relative concentrations of TRKA, NTRp75, phosphorylated NFκB (pNFκB) and total NFκB in lesions were measured by EIA. Compared with the WT group, the KO mice showed lower TNFα levels in the peritoneal fluid and lower numbers of COX2 immunoreactive cells along with increased expression of GRα, ß-III TUBULIN, Pgp 9.5, SP, Th, BDNF, NGF, NTRp75 and pNFκB in the lesions. Future histological studies will be necessary to confirm the sensory/sympathetic imbalance in the endometriotic-like lesions of the KO mice. Our results suggest that a reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55-/- mice. Chronic deregulation of TNF receptors can have serious consequences for women with advanced endometriosis.

Natural therapies assessment for the treatment of endometriosis.

STUDY QUESTION: Can resveratrol and epigallocatechin-3-gallate (EGCG) inhibit the growth and survival of endometriotic-like lesions in vivo in a BALB/c model of endometriosis, and in vitro in primary cultures of human endometrial epithelial cells (EECs)? SUMMARY ANSWER: Resveratrol and EGCG exerted a potent inhibitory effect on the development of endometriosis in a BALB/c murine model and on the survival of EECs. WHAT IS KNOWN ALREADY: Endometriosis is a common condition associated with infertility and pelvic pain in women of reproductive age. Resveratrol and EGCG are two polyphenols with anticarcinogenic and antioxidant properties that have been proposed as natural therapies to treat endometriosis. STUDY DESIGN, SIZE, DURATION: Fifty-six 2-month-old female BALB/c mice underwent surgical induction of endometriosis. Treatments with resveratrol or EGCG started 15 days post-surgery and continued for 4 weeks. Human biopsies were taken with a metal Novak curette from the posterior uterine wall from 16 patients with untreated endometriosis and 15 controls who underwent diagnostic laparoscopy for infertility. MATERIALS, SETTING, METHODS: After the treatments, animals were sacrificed and lesions were counted, measured, excised and fixed. Immunohistochemistry for proliferating cell nuclear antigen and CD34 was performed for cell proliferation and vascularization assessment in the lesions. The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) technique was performed for apoptosis evaluation. Peritoneal fluid was collected to analyze vascular endothelial growth factor levels. Human EECs were purified from proliferative-phase endometrial biopsies and cultured. The effect of both polyphenols on cell proliferation was determined by a colorimetric assay using the CellTiter 96®AQueous One Solution Cell Proliferation Assay kit and on apoptosis by the TUNEL technique, using an In Situ Cell Death Detection Kit with Fluorescein. MAIN RESULTS: In the mouse model, both treatments significantly reduced the mean number (P < 0.05 versus control) and the volume of established lesions (P < 0.05 versus control). Treatments consistently statistically significantly diminished cell proliferation (resveratrol P < 0.01 and EGCG P < 0.05, versus control), reduced vascular density (resveratrol P < 0.01 and EGCG P < 0.001, versus control) and increased apoptosis within the lesions (resveratrol P < 0.01 and EGCG P < 0.05, versus control). Both compounds induced reduction in human EEC proliferation (P < 0.05 versus basal) and increased apoptosis (P < 0.05 versus basal) in primary cultures. LIMITATIONS: In vitro studies were only carried out in epithelial cells from human eutopic endometrium. WIDER IMPLICATIONS OF THE FINDINGS: The present findings are promising and will assist the development of novel natural treatments for endometriosis. STUDY FUNDING: This study was supported by ANPCYT (PICT 6384 BID 1201 OC-AR) and CONICET (PIP 5471), Argentina. None of the authors has any conflict of interest to declare.

Effects of a selective cyclooxygenase-2 inhibitor on endometrial epithelial cells from patients with endometriosis.

BACKGROUND: Celecoxib, a selective cyclooxygenase (COX)-2 inhibitor, also has anti-proliferative properties and pro-apoptotic effects on different in vivo and in vitro models, two actions that may be efficacious in therapy for endometriosis. We evaluated the effects of celecoxib on apoptosis and proliferation, and vascular endothelial growth factor (VEGF) production and COX-2 expression and activity in endometrial epithelial cells (EECs). METHODS AND RESULTS: Thirty-two endometriosis and 13 control women were included in the study. EECs from eutopic endometrium and control biopsies were cultured with different doses of celecoxib. Celecoxib at 50, 75 and 100 microM (versus vehicle control) inhibited EEC proliferation in cultures from controls (P < 0.05, P < 0.01 and P < 0.01, respectively) and patients with endometriosis (P < 0.05, P < 0.01 and P < 0.01), as assessed by (3)H-thymidine uptake. Celecoxib at 50, 75 and 100 microM induced apoptosis in EEC from controls (P < 0.05, P < 0.001 and P < 0.001) and patients with endometriosis (P < 0.001, P < 0.001 and P < 0.01), as revealed by the Acridine Orange-Ethidium Bromide technique. Western blot analysis showed that celecoxib was effective at increasing COX-2 protein at 100 microM in EEC from endometriosis patients (P < 0.05). In EEC from endometriosis patients, celecoxib at 25, 50 and 100 microM was also effective in reducing COX-2 activity, reflected in the reduction of prostaglandin E(2) (PGE(2)) synthesis (P < 0.001), and VEGF secretion (P < 0.001; P < 0.05 and P < 0.001), assessed by enzyme-linked immunosorbent assay. Exogenous PGE(2) did not reverse celecoxib-induced growth inhibition. CONCLUSIONS: This study suggests a direct effect of celecoxib on reduction of endometrial growth and supports further research on selective COX-2 inhibition as a novel therapeutic modality in endometriosis.

Effect of GnRH analogues on apoptosis and expression of Bcl-2, Bax, Fas and FasL proteins in endometrial epithelial cell cultures from patients with endometriosis and controls.

BACKGROUND: Our purpose was to evaluate the effect of the GnRH agonist (GnRHa), leuprolide acetate (LA), and the GnRH antagonist (GnRHant), Antide, on apoptosis and expression of apoptosis-related proteins in endometrial epithelial cell (EEC) cultures from patients with endometriosis and controls (infertile women without endometriosis). METHODS: Biopsy specimens of eutopic endometrium were obtained from 22 patients with endometriosis and from 14 women that served as controls. Apoptosis was examined in EEC after incubation with LA and Antide. Bax, Bcl-2, Fas and FasL expression was evaluated after exposure to LA, Antide or a combination of both. The percentage of apoptotic cells (%ApC) was assessed by the acridine orange-ethidium bromide technique, and protein expression was evaluated by western blot and immunocytochemistry. RESULTS: LA 100 and 1000 ng/ml increased the %ApC in EEC from patients with endometriosis (both P < 0.05) and controls (p < 0.05 and P < 0.01, respectively). Antide 10(-5) M increased the %ApC in EEC from patients with endometriosis and controls (P < 0.01). In EEC from women with endometriosis, Bax expression increased after treatment with LA, Antide and LA + Antide (P < 0.05, P < 0.001 and P < 0.001), whereas Bcl-2 expression decreased after exposure to LA and Antide (P < 0.001 and P < 0.01). FasL expression increased after LA, Antide and LA + Antide treatments (P < 0.01, P < 0.001 and P < 0.01). No significant changes were observed on Fas expression. CONCLUSIONS: GnRH analogues enhanced apoptosis in EEC, and this was accompanied by an increase in expression of the pro-apoptotic proteins Bax and FasL and a decrease in expression of the anti-apoptotic protein Bcl-2.

Apoptosis and expression of Bcl-2 and Bax in eutopic endometrium from women with endometriosis.

OBJECTIVE: To evaluate and compare spontaneous apoptosis and Bcl-2 and Bax expression in eutopic endometrium from women with and without endometriosis. DESIGN: Apoptosis and Bcl-2 and Bax expression were examined in eutopic endometrium from women with and without endometriosis. SETTING: Instituto de Biología y Medicina Experimental-CONICET, Department of Gynecology and Department of Gynecological Pathology, Clínicas University Hospital, Buenos Aires, Argentina. PATIENT(S): Women with untreated endometriosis (n = 14) and controls (n = 16). INTERVENTION(S): Collection of endometrial samples during diagnostic or therapeutic laparoscopy. MAIN OUTCOME MEASURE(S): Apoptotic cells were detected with use of the dUTP nick-end labeling (TUNEL) assay; Bcl-2 and Bax expressions were assessed with use of immunohistochemical techniques. RESULT(S): Spontaneous apoptosis was significantly lower in eutopic endometrium from patients with endometriosis, compared with healthy controls (2.26 +/- 0.53 and 9.37 +/- 1.69 apoptotic cells/field, respectively) and was independent of cycle phase. An increased expression of Bcl-2 protein was found in proliferative eutopic endometrium from patients with endometriosis. Bax expression was absent in proliferative endometrium, whereas there was an increase in its expression in secretory endometrium from both patients and controls. CONCLUSION(S): Women with endometriosis show decreased number of apoptotic cells in eutopic endometrium. The abnormal survival of endometrial cells may result in their continuing growth into ectopic locations.

Functional and phenotypic alterations in peritoneal macrophages from patients with early and advanced endometriosis.

The aim of this study was to elucidate whether peritoneal macrophage (pMO) alterations are a generalized feature in all stages of endometriosis and the effect of hormonal treatment on this leukocyte population. For this purpose we quantified the number of pMO, the expression of HLA-DR antigen (pMO DR+), percentages of pMO that reduced nitro-blue tetrazolium (pMO NBT+), and interleukin-1 (IL-1) and prostaglandin E2 (PGE2) production by pMO from patients with early (stages I/II) and advanced (stages III/IV) endometriosis, we also analyzed some of these properties in pMO from patients which had been treated for 6 months with 800 mg/day of Danazol or gonadotropin releasing hormone agonist (GnRHa). We found that there were a significant increase of the pMO number in both types of patients, though the highest values were obtained in early endometriosis (p < 0.001). Percentages of pMO DR+ were decreased in all patients (p < 0.01) while percentages of pMO NBT+ were significantly increased. Production of IL-1 by early and advanced endometriosis pMO were considerably enhanced. PGE2 release was not altered in early endometriosis pMO but, in advanced endometriosis, pMO PGE2 levels were 100-fold higher than control values. In posttreatment patients, the number of pMO and percentage of pMO NBT+ were similar to early endometriosis patients, though the percentage of pMO DR+ was within the normal range. We conclude that the pMO population, as well as IL-1 and PGE2 production, were altered in all stages of endometriosis, and that these changes could be involved in the pathogenesis of endometriosis and associated infertility. Hormonal treatments do not reverse the pMO changes.

Effect of peritoneal fluid from patients with mild and severe endometriosis on endometrial stromal cell proliferation.

The aim of this study was to evaluate and compare the mitogenic effect of peritoneal fluid (PF) from women with mild and severe endometriosis on the endometrial stromal cell proliferation. Increasing concentrations of PF from women with and without mild or severe endometriosis were added to primary endometrial stromal cell cultures and 3H-thymidine incorporation was used to assess DNA synthesis in these cultures. PF from women with mild endometriosis induced a statistically significant dose-dependent increase in stromal cell thymidine uptake ranged from 5.8 to 14.5 fold, whereas PF from women with severe endometriosis produced an average 51% inhibition of stromal cell proliferation of compared with cells exposed to non-endometriosis PF or exposed to nutrient medium supplemented with 2.5% calf serum alone. PF samples from patients with stage I endometriosis induced a statistically dose-dependent increase in stromal cell proliferation, whereas PF from patients with stage IV endometriosis caused a significant inhibition.

Murine peritoneal macrophages in syngeneic and allogeneic pregnancies.

We have previously observed that some functional characteristics of peritoneal macrophages (MOp) are altered during syngeneic murine pregnancy. To determine if these alterations are related to the immunological stimulation that the embryo produces on the mother, we evaluated MOp activity in allogeneic pregnancy. We also compared expression of the la antigen, ability to phagocyte and reduce nitro blue tetrazolium (NBT) and to produce interleukin-1 (IL-1) in allogeneic and syngeneic pregnancies. We observed that at Day 7 of pregnancy the increment in MOpIa(+) percentages was more evident in allogeneic (P < 0.05) than syngeneic pregnancies, and that these values remained high during the second week of gestation. We also observed a significant decrease in the macrophages that reduced NAT during the first week both in allogeneic and syngeneic pregnancies. Yet, in the former, the percentages of MOpNBT(+) were still low in the last week of pregnancy (P < 0.05). No differences were found in IL-1 production or in estradiol and progesterone levels between the 2 types of pregnancies. Thus, it is possible to postulate that during the first week of pregnancy the strong antigenic challenge that the embryo represents may activate MOp and that this activation could be augmented when major antigenic differences between mother and embryo are present.