PI3K/AKT pathway is altered in the endometriosis patient's endometrium and presents differences according to severity stage.

Based on the inflammatory nature and hormone-dependency of endometriosis, PI3K/AKT signaling appears to influence its progression. Could the endometriosis stages be linked to differential changes in PI3K/AKT pathway regulation? The objective is to evaluate the expression of PI3K, PTEN, AKT and p-AKT in endometrial human biopsies, according to the presence or absence of the disease, and to assess the underlying differences regarding the endometriosis stages. Biopsy specimens of the ectopic and eutopic endometrium were obtained from twenty women with untreated peritoneal endometriosis as well as endometrium biopsies from nine controls. Our study revealed an increased expression of PI3K in eutopic and ectopic endometrium from patients with endometriosis, and a reduced expression of PTEN and increased levels of AKT phosphorylation, compared to control endometrium. Both eutopic and ectopic endometrium from patients with minimal-mild endometriosis expressed a significant reduced PTEN level compared to the respective endometrium from patients with moderate-severe endometriosis. The ratio p-AKT/total AKT showed higher levels of AKT phosphorylation in endometriotic tissue from patients with minimal-mild endometriosis. This study has firmly confirmed the alteration in PI3K/AKT pathway regulation and demonstrated clear differences between the stages of endometriosis, emphasizing the importance of this pathway in the first stage of the disease.

Targeting galectin-1-induced angiogenesis mitigates the severity of endometriosis.

Endometriosis is characterized by the presence of endometrial tissue outside the uterus that causes severe pelvic pain and infertility in women of reproductive age. Although not completely understood, the pathophysiology of the disease involves chronic dysregulation of inflammatory and vascular signalling. In the quest for novel therapeutic targets, we investigated the involvement of galectin-1 (Gal-1), an endogenous glycan-binding protein endowed with both immunosuppressive and pro-angiogenic activities, in the pathophysiology of endometriotic lesions. Here we show that Gal-1 is selectively expressed in stromal and endothelial cells of human endometriotic lesions. Using an experimental endometriosis model induced in wild-type and Gal-1-deficient (Lgals1(-/-) ) mice, we showed that this lectin orchestrates the formation of vascular networks in endometriotic lesions in vivo, facilitating their ectopic growth independently of vascular endothelial growth factor (VEGF) and the keratinocyte-derived CXC-motif (CXC-KC) chemokine. Targeting Gal-1 using a specific neutralizing mAb reduced the size and vascularized area of endometriotic lesions within the peritoneal compartment. These results underline the essential role of Gal-1 during endometriosis and validate this lectin as a possible target for the treatment of disease.

Anastrozole and celecoxib for endometriosis treatment, good to keep them apart?

Endometriosis is a benign gynecological disease. Cyclooxygenase-2 (COX-2) and aromatase proteins have been shown to be overexpressed in eutopic endometrium from women suffering from this disease compared to disease-free women. Furthermore, inhibition of these molecules individually was demonstrated to have antiproliferative and proapoptotic effects both in vitro and in vivo in several models. In this study, the effect of combining celecoxib, a selective COX-2 inhibitor, and anastrozole, an aromatase inhibitor, on the implantation and growth of endometriotic like lesions in a murine model of endometriosis was evaluated. Endometriosis was surgically induced in female BALB/c mice. After 28 days of treatment with celecoxib, anastrozole, or their combination, animals were killed and lesions were counted, measured, excised, and fixed. Immunohistochemistry for proliferating cell nuclear antigen and CD34 was performed for assessment of cell proliferation and vascularization. TUNEL technique was performed for apoptosis evaluation. Celecoxib was the only treatment to significantly reduce the number of lesions established per mouse, their size and vascularized area. In addition, cell proliferation was significantly diminished and apoptosis was significantly enhanced by both individual treatments. When the therapies were combined, they reversed their effects. These results confirm that celecoxib and anastrozole separately decrease endometriotic growth, but when combined they might have antagonizing effects.

A physiological concentration of anandamide promotes the migration of human endometrial fibroblast and the interaction with endothelial cells invitro.

INTRODUCTION: The mechanisms that govern fibroblast behavior during the vascular adaptations of the uterus at early pregnancy remain unknown. Anandamide, an endocannabinoid, binds to cannabinoid receptors (CBs), and regulates gestation and angiogenesis. Its tone is regulated by fatty acid amide hydrolase (FAAH) within the uterus. We investigated the role of anandamide in endometrial fibroblasts migration and whether anandamide modulates fibroblasts-endothelial crosstalk. METHODS: T-hESC and EA.hy926 cell lines were used as models of endometrial stromal and endothelial cells, respectively. T-hESC were incubated with anandamide plus different agents. Migration was tested (wound healing assay and phalloidin staining). Protein expression and localization were studied by Western blot and immunofluorescence. To test fibroblast-endothelial crosstalk, EA.hy926 cells were incubated with fibroblast conditioned media obtained after T-hESC migration. RESULTS: Anandamide 1 nM increased T-hESC migration via CB1 and CB2. Cyclooxygenase-2 participated in anandamide-stimulated fibroblast migration. Prostaglandin F2alpha, and not prostaglandin E2, increased fibroblast wound closure. CB1, CB2, cyclooxygenase-2 and FAAH were expressed in T-hESC. Anandamide did not alter cyclooxygenase-2 localization but induced its cytoplasmic and nuclear expression through CB1 and CB2. URB-597, a FAAH selective inhibitor, also increased T-hESC migration via both CBs, and augmented cyclooxygenase-2 expression. Conditioned media from anandamide-induced T-hESC wound healing closure stimulated endothelial migration and did not alter their proliferation. Soluble factors from cyclooxygenase-2 were secreted by T-hESC and participated in T-hESC-induced EA.hy926 migration. Although anandamide-conditioned media augmented in EA.hy926 the expression of γH2AX, a marker of DNA damage, cyclooxygenase-2 was not involved in this effect. DISCUSSION: Our results provide novel evidence about an active role of anandamide on endometrial fibroblast behavior as a mechanism regulating uterine vascular adaptations in early gestation.

Plants as source of new therapies for endometriosis: a review of preclinical and clinical studies.

BACKGROUND: Given the disadvantages and limitations of current endometriosis therapy, there is a progressive increase in studies focusing on plant-derived agents as a natural treatment option with the intention of achieving high efficiency, avoiding adverse effects and preserving the chance for successful pregnancy. The heterogeneity of these studies in terms of evaluated agents, applied approaches and outcomes illustrates the need for an up-to-date summary and critical view on this rapidly growing field in endometriosis research. OBJECTIVE AND RATIONALE: This review provides a comprehensive overview of plant-derived agents and natural treatment strategies that are under preclinical or clinical investigation and critically evaluates their potential for future endometriosis therapy. SEARCH METHODS: An English language PubMed literature search was performed using variations of the terms 'endometriosis', 'natural therapy', 'herb/herbal', 'plant', 'flavonoid', 'polyphenol', 'phytochemical', 'bioactive', 'Kampo' and 'Chinese medicine'. It included both animal and human studies. Moreover, the Clinicaltrials.gov database was searched with the term 'endometriosis' for clinical trials on plant-derived agents. No restriction was set for the publication date. OUTCOMES: Natural therapies can be assigned to three categories: (i) herbal extracts, (ii) specific plant-derived bioactive compounds and (iii) Chinese herbal medicine (CHM). Agents of the first category have been shown to exert anti-proliferative, anti-inflammatory, anti-angiogenic and anti-oxidant effects on endometrial cells and endometriotic lesions. However, the existing evidence supporting their use in endometriosis therapy is quite limited. The most studied specific plant-derived bioactive compounds are resveratrol, epigallocatechin-3-gallate, curcumin, puerarin, ginsenosides, xanthohumol, 4-hydroxybenzyl alcohol, quercetin, apigenin, carnosic acid, rosmarinic acid, wogonin, baicalein, parthenolide, andrographolide and cannabinoids, with solid evidence about their inhibitory activity in experimental endometriosis models. Their mechanisms of action include pleiotropic effects on known signalling effectors: oestrogen receptor-α, cyclooxygenase-2, interleukin-1 and -6, tumour necrosis factor-α, intercellular adhesion molecule-1, vascular endothelial growth factor, nuclear factor-kappa B, matrix metalloproteinases as well as reactive oxygen species (ROS) and apoptosis-related proteins. Numerous studies suggest that treatment with CHM is a good choice for endometriosis management. Even under clinical conditions, this approach has already been shown to decrease the size of endometriotic lesions, alleviate chronic pelvic pain and reduce postoperative recurrence rates. WIDER IMPLICATIONS: The necessity to manage endometriosis as a chronic disease highlights the importance of identifying novel and affordable long-term safety therapeutics. For this purpose, natural plant-derived agents represent promising candidates. Many of these agents exhibit a pleiotropic action profile, which simultaneously inhibits fundamental processes in the pathogenesis of endometriosis, such as proliferation, inflammation, ROS formation and angiogenesis. Hence, their inclusion into multimodal treatment concepts may essentially contribute to increase the therapeutic efficiency and reduce the side effects of future endometriosis therapy.

Apoptosis is increased and cell proliferation is decreased in out-of-phase endometria from infertile and recurrent abortion patients.

BACKGROUND: Various endometrial abnormalities have been associated with luteal phase deficiency: a significant dyssynchrony in the maturation of the glandular epithelium and the stroma and a prevalence of out-of-phase endometrial biopsy specimens. Out-of phase endometrium is a controversial disorder related to failed implantation, infertility and early pregnancy loss. Given that the regulation of the apoptotic process in endometrium of luteal phase deficiency is still unknown, the aim of this study was to evaluate cell proliferation, apoptosis and the levels of the main effector caspase, caspase-3 in the luteal in-phase and out-of-phase endometrium. METHODS: Thirty-seven endometrial samples from sterile or recurrent abortion patients were included in this study: 21 in-phase samples (controls) and 16 samples with out-of-phase endometrium. Biopsy specimens of eutopic endometrium were obtained from all subjects during days 21-25 of the menstrual cycle. The endometrium with endometrial maturity of cycle day 25 or less at the time of menstruation was considered out-of phase. Endometrial tissues were fixed in 10% buffered formaldehyde. For apoptosis quantification, sections were processed for in situ immunohistochemical localization of nuclei exhibiting DNA fragmentation, by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP digoxygenin nick-end labeling (TUNEL) technique. Expressions of Proliferating Cell Nuclear Antigen (PCNA) as a marker of cell proliferation, and of cleaved caspase-3 as a marker of apoptosis, were assessed by immunohistochemistry in the luteal in-phase and out-of-phase endometrium from infertile and recurrent abortion patients. RESULTS: Luteal out-of-phase endometrium had increased apoptosis levels compared to in-phase endometrium (p < 0.05). Caspase-3 evaluation confirmed these results: the luteal out-of-phase endometrium showed augmented cleaved caspase-3 expression (p < 0.005). As well, our data demonstrated that the luteal out-of-phase endometrium expresses decreased PCNA levels (p < 0.05), showing that cell proliferation is diminished in this tissue. CONCLUSIONS: this study represents the first report describing variations at the cell proliferation and cell death levels in the out-of-phase endometrium in comparison with in-phase endometrium from infertile and recurrent abortion patients. Further studies are needed to elucidate a potential role of these alterations in the physiopathology of luteal phase deficiency.

Inhibition of Hyaluronic Acid Synthesis Suppresses Angiogenesis in Developing Endometriotic Lesions.

BACKGROUND: The development and long-term survival of endometriotic lesions is crucially dependent on an adequate vascularization. Hyaluronic acid (HA) through its receptor CD44 has been described to be involved in the process of angiogenesis. OBJECTIVE: To study the effect of HA synthesis inhibition using non-toxic doses of 4-methylumbelliferone (4-MU) on endometriosis-related angiogenesis. MATERIALS AND METHODS: The cytotoxicity of different in vitro doses of 4-MU on endothelial cells was firstly tested by means of a lactate dehydrogenase assay. The anti-angiogenic action of non-cytotoxic doses of 4-MU was then assessed by a rat aortic ring assay. In addition, endometriotic lesions were induced in dorsal skinfold chambers of female BALB/c mice, which were daily treated with an intraperitoneal injection of 0.9% NaCl (vehicle group; n = 6), 20 mg/kg 4-MU (n = 8) or 80 mg/kg 4-MU (n = 7) throughout an observation period of 14 days. The effect of 4-MU on their vascularization, survival and growth were studied by intravital fluorescence microscopy, histology and immunohistochemistry. MAIN RESULTS: Non-cytotoxic doses of 4-MU effectively inhibited vascular sprout formation in the rat aortic ring assay. Endometriotic lesions in dorsal skinfold chambers of 4-MU-treated mice dose-dependently exhibited a significantly smaller vascularized area and lower functional microvessel density when compared to vehicle-treated controls. Histological analyses revealed a downregulation of HA expression in 4-MU-treated lesions. This was associated with a reduced density of CD31-positive microvessels within the lesions. In contrast, numbers of PCNA-positive proliferating and cleaved caspase-3-positive apoptotic cells did not differ between 4-MU-treated and control lesions. CONCLUSIONS: The present study demonstrates for the first time that targeting the synthesis of HA suppresses angiogenesis in developing endometriotic lesions. Further studies have to clarify now whether in the future this anti-angiogenic effect can be used beneficially for the treatment of endometriosis.

Oral contraceptives suppress cell proliferation and enhance apoptosis of eutopic endometrial tissue from patients with endometriosis.

OBJECTIVE: To evaluate the effects of administering combination oral contraceptives (COCs) to patients with endometriosis on the regulation of cell growth in the eutopic endometrium. DESIGN: Prospective study. SETTING: Research institute and clinical fertility center. PATIENT(S): Thirteen women with untreated endometriosis and 13 controls. INTERVENTION(S): Biopsy specimens of the eutopic endometrium were obtained from all subjects. Apoptosis, cell proliferation, and Bcl-2 and Bax expression were examined at the epithelial and stromal levels in the eutopic endometrium from patients with endometriosis before and after 30 days of daily exposure to COCs and from controls. MAIN OUTCOME MEASURE(S): Apoptotic cells were detected by using the dUTP nick-end labeling assay; Ki-67, Bcl-2, and Bax expressions were assessed by using immunohistochemical techniques. RESULT(S): After exposure to COCs, apoptosis was significantly increased in the eutopic endometrium compared with before COC administration, both at epithelial and stromal levels. Cell proliferation was significantly lowered by COCs. CONCLUSION(S): COCs showed a positive effect on patients with endometriosis by down-regulating cell proliferation and enhancing apoptosis in the eutopic endometrium.

Gonadotropin-releasing hormone agonist induces apoptosis and reduces cell proliferation in eutopic endometrial cultures from women with endometriosis.

OBJECTIVE: There is growing evidence that suggests a direct action of gonadotropin-releasing hormone agonist (GnRH-a) on endometrial growth. Consequently, our purpose was to evaluate the effect of GnRH-a on in vitro eutopic endometrial cell growth and apoptosis. DESIGN: Prospective study. SETTING: Research institute and clinical fertility center. PATIENT(S): Sixteen women with untreated endometriosis and 14 controls. INTERVENTION(S): Biopsy specimens of eutopic endometrium were obtained from all subjects. Apoptosis and cell proliferation were examined in epithelial endometrial cell cultures after incubation with leuprolide acetate (LA), antide, and a combination of both. MAIN OUTCOME MEASURE(S): The percentage of apoptotic cells was evaluated by the acridine orange-ethidium bromide technique; cell proliferation was assessed by (3)H-thymidine incorporation. RESULT(S): Leuprolide acetate (LA) (100 ng/mL) enhanced apoptosis in endometrial cultures from patients with endometriosis and controls, and this effect was reversed by antide 10(-7)M. Cell proliferation was down-regulated by LA at 1, 10, and 100 ng/mL in cultures from women without and with endometriosis. The addition of antide 10(-7)M reversed this inhibition. CONCLUSION(S): GnRH-a appears to have a direct effect by enhancing the apoptotic index and decreasing the cell proliferation in endometrial cells.

Effects of aromatase inhibitors on proliferation and apoptosis in eutopic endometrial cell cultures from patients with endometriosis.

OBJECTIVE: To study the effect of letrozole (Let) and anastrozole (Anas) on apoptosis and cell proliferation in epithelial endometrial cells (EEC) from patients with endometriosis (EDT). DESIGN: Prospective study. SETTING: Research institute and clinical fertility center. PATIENT(S): Eighteen women with untreated EDT. INTERVENTION(S): Biopsy specimens of eutopic endometrium were obtained from all subjects. Apoptosis and cell proliferation were examined in EEC after incubation with Let or Anas. MAIN OUTCOME MEASURE(S): Percentage of apoptotic cells (ApC) was evaluated by the acridine orange-ethidium bromide technique; cell proliferation was assessed by 3H-thymidine incorporation. RESULT(S): Treatment with Let 10 nM and Let 100 nM enhanced values of ApC in cultures from EDT patients. Epithelial endometrial cells treated with Anas 100 nM or Anas 500 nM showed a statistically significant induction on apoptosis levels. Cultures treated with Let 1 nM or Anas 50 nM did not show any significant differences in ApC levels compared with basal conditions. 3H-Thymidine uptake was down regulated by Let 10 nM and Let 100 nM. Similarly, Anas 100 nM and Anas 500 nM showed a significantly lower degree of cell proliferation in EEC. Lower concentrations of Let and Anas did not induce any significant change in cell proliferation rates. CONCLUSION(S): Our results show that Let and Anas produced a significant and positive effect on apoptosis and cell proliferation on EEC from EDT patients. These findings support the further investigation of aromatase inhibitors as a treatment option in EDT.

Effect of GnRH analogues on apoptosis and release of interleukin-1beta and vascular endothelial growth factor in endometrial cell cultures from patients with endometriosis.

BACKGROUND: The aim of the present study was to evaluate the effect of GnRH analogues on the in-vitro eutopic endometrial cell apoptosis and release of interleukin-1beta (IL-1beta) and vascular endothelial growth factor (VEGF). METHODS: Biopsy specimens of eutopic endometrium obtained from 16 women with untreated endometriosis and 14 controls were studied. Apoptosis, IL-1beta and VEGF release were evaluated in epithelial endometrial cell cultures after incubation with leuprolide acetate (LA) as GnRH agonist, antide as GnRH antagonist, and a combination of both. The percentage of apoptotic cells was evaluated by the acridine orange-ethidium bromide technique, and IL-1beta and VEGF concentrations were assessed by using commercial enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: We found that LA (100 ng/ml) enhanced apoptosis in endometrial cell cultures from endometriosis patients and controls and this effect was reversed by antide at 10(-7) mol/l. IL-1beta and VEGF release was downregulated by LA in cultures from controls and endometriosis patients. The addition of antide 10(-7) mol/l reversed this inhibition. Endometrial cultures treated with antide at 10(-7) mol/l did not show any significant effects compared with basal conditions. CONCLUSIONS: GnRH agonists appear to have a direct effect in endometrial cells cultures, by enhancing the percentage of apoptotic cells and decreasing the release of pro-mitogenic cytokines such as IL-1beta and VEGF.

Evaluación y comparación del efecto mitogénico del fluido peritoneal de pacientes con endometriosis mínima y avanzada / Valuation and comparison of mitogenic effect of peritoneal fluid in patients with mild and advanced endometriosis

Objetivo: Evaluar y comparar el efecto mitogénico del fluido peritoneal de mujeres con endometriosis mínima y severa sobre la proliferación de células estronales endometriales en cultivo. Materiales y Métodos: Se establecieron cultivos primarios de células estronales de endometrio humano. Se agregaron concentraciones crecientes de fluido peritoneal de pacientes con endometriosis mínima y severa, y de controles. Se evaluó incorporación de Timidina tritiada (3[H]-Timidina) como parámetro de síntesis de ADN en esas células. Resultados: El fluido peritoneal de mujeres con endometriosis mínima indujo un incremento significativo y dosis-dependiente de la incorporación de 3[H]-Timidina que osciló entre el 580 por ciento y el 1450 por ciento de los controles. El fluido peritoneal de pacientes con endometriosis severa provocó una inhibición del 51 por ciento en promedio de la proliferación celular comparando con células que fueron expuestas a fluidos peritoneales controles o a medio de cultivo suplementado con 2,5 por ciento de suero bovino fetal. Conclusiones: Se hallaron diferencias significativas en cuanto al efecto mitogénico del fluido peritoneal de pacientes con distintos estadíos de endometriosis. Las muestras provenientes de pacientes con endometriosis mínima indujeron un incremento de la proliferación celular, mientras que el fluido peritoneal de endometriosis severa inhibió significativamente el crecimiento de las células endometriales en cultivo

Apoptosis y expresión de Bcl-2 y Bax en el endometrio eutópico de pacientes con endometriosis / Apoptosis and Bcl-2 and Bax in normal endometrium of patients with endometriosis

El objetivo de este trabajo es investigar una posible predisposición de las células endometriales de pacientes con endometriosis (EDT), a ser resistentes a la muerte celular programada. Se evaluó apoptosis y expresión de las proteínas Bcl-2 y Bax en 30 cortes de tejido de endometrio eutópico, 14 de mujeres con EDT y 16 de controles (C). Para la determinación de apoptosis, se utilizó el kit Apoptag-Plus basado en la localización y tinción de los extremos 3'-OH de los fragmentos de ADN. Los resultados se expresan como nº de células apoptóticas (CA)/campo a 630x de aumento. Se detectaron CA sólo en el epitelio glandular. Se observó menor cantidad de CA en tejido endometrial proveniente de pacientes con EDT: 2,26 ñ 0,53 vs 9,37 ñ 1,69 en los C (p<0,001). Esta disminución se conservó a lo largo del ciclo menstrual. En la fase proliferativa tardía, los resultados fueron de: 7,08 ñ 0,92 vs 1,9 ñ 0,73 (p<0,05), para las muestras provenientes de mujeres C y pacientes con EDT respectivamente; mientras que en el endometrio secretorio los niveles de apoptosis detectados fueron de 11,6 ñ 1,74 en los C vs 2,7 ñ 0,82 en EDT (p<0,001). No se observaron diferencias significativas de apoptosis en endometrio de acuerdo al grado de la enfermedad. La evolución de los productos de protooncógenes, bcl-2 y bax se realizó utilizando metodologías de inmunohistoquímica. Se halló incrementada la expresión de la proteína antiapoptótica Bcl-2 en el endometrio proliferativo proveniente de pacientes con EDT comparado con el C. La expresión del antagonista de Bcl-2, Bax, aumentó durante la fase secretoria tanto en muestras provenientes de pacientes como de C, y se halló ausente durante la fase proliferativa. De los resultados se desprende que las células endometriales de pacientes con EDT poseen características apoptóticas alteradas que las harían más susceptibles a crecer en un sitio ectópico. Estas no se ven modificadas a lo largo del ciclo menstrual. La proteína Bcl-2 estaría implicada en la protección de la apoptosis de las células endometriales eutópicas de pacientes con EDT durante la fase proliferativa del ciclo menstrual. La proteína Bax estaría involucrada en la regulación de la muerte celular programada que se produce en el endometrio eutópico previo a la menstruación. La resistencia a la muerte celular programada que posee el endometrio eutópico de pacientes con EDT, estaría relacionada con la etiología y/o fisiopatología de la enfermedad