Lipoxin A₄ prevents the progression of de novo and established endometriosis in a mouse model by attenuating prostaglandin E₂ production and estrogen signaling

Endometriosis, a leading cause of pelvic pain and infertility, is characterized by ectopic growth of endometrial-like tissue and affects approximately 176 million women worldwide. The pathophysiology involves inflammatory and angiogenic mediators as well as estrogen-mediated signaling and novel, improved therapeutics targeting these pathways are necessary. The aim of this study was to investigate mechanisms leading to the establishment and progression of endometriosis as well as the effect of local treatment with Lipoxin A₄ (LXA₄), an anti-inflammatory and pro-resolving lipid mediator that we have recently characterized as an estrogen receptor agonist. LXA₄ treatment significantly reduced endometriotic lesion size and downregulated the pro-inflammatory cytokines IL-1β and IL-6, as well as the angiogenic factor VEGF. LXA₄ also inhibited COX-2 expression in both endometriotic lesions and peritoneal fluid cells, resulting in attenuated peritoneal fluid Prostaglandin E₂ (PGE₂) levels_. Besides its anti-inflammatory effects, LXA₄ differentially regulated the expression and activity of the matrix remodeling enzyme matrix metalloproteinase (MMP)-9 as well as modulating transforming growth factor (TGF)-β isoform expression within endometriotic lesions and in peritoneal fluid cells. We also report for first time that LXA₄ attenuated aromatase expression, estrogen signaling and estrogen-regulated genes implicated in cellular proliferation in a mouse model of disease. These effects were observed both when LXA₄ was administered prior to disease induction and during established disease. Collectively, our findings highlight potential targets for the treatment of endometriosis and suggest a pleotropic effect of LXA₄ on disease progression, by attenuating pro-inflammatory and angiogenic mediators, matrix remodeling enzymes, estrogen metabolism and signaling, as well as downstream proliferative pathways.

[Efficacy observation on the combination of acupuncture and Chinese medication in prevention of the recurrence of endometriosis after laparoscopic surgery]

OBJECTIVE

To evaluate the efficacy and safety of acupuncture-moxibustion combined with modified Mojie tablet (see text) in the prevention of the recurrence of endometriosis (EMS) after laparoscopic surgery.

METHODS

After laparoscopic surgery, 120 cases of EMS were randomized into an acupuncture-moxibustion group, a western medication group, a Chinese medication group and a combined therapy of acupuncture-moxibustion and Chinese medication group (combined therapy group), 30 cases in each one. In the acupuncture-moxibustion group, acupuncture was applied at Xuehai (SP 10), Sanyinjiao (SP 6) and Guanyuan (CV 4); the isolated moxibustion with ginger was used at Guanyuan (CV 4), once a day, twice a week. In the western medication group, gestrinone was prescribed for oral administration, 2.5 mg, once a day, twice a week. In the Chinese medication group, the self-prepared Mojie tablet were prescribed for oral administration. In the combined therapy group, acupuncture, moxibustion and modified Mojie tablet for oral administration were used in combination. The therapeutic methods were same as the acupuncture-moxibustion group and the Chinese medication group. Totally, the treatment of 3 months was required. Separately, before treatment, after treatment, in 3 months after treatment and in 6 months after treatment, EHP-5 score (endometriosis health profile-5), the abdominal/vaginal ultrasound examination, serum CA125 detection and safety index (ALT detection) were compared in patients among 4 groups.

RESULTS

In 3 and 6 months after treatment, the positive rates of EHP-5 score were 0% (0/30) in the combined therapy group and 0% (0/30) in the acupuncture-moxibuston group, which were all lower significantly than 13.3% (4/30) in the western medication group (both P < 0.05). In follow-up stage of 6 months after treatment, there was no recurrence case in abdominal lviginal ultrasound examination in the combined therapy group, which was lower than 13.3% (4/30) in the western medication group (P < 0.05); the serum CA125 detection in the combined therapy group did not find any abnormal case, which was lower than 16.7% (5/30) in the western medication group (P < 0.05). At the end of treatment session and in the follow-up stage of 3 months after treatment, the abnormal rate of ALT were 20.0% (6/30) and 13.3% (4/30) in the western medication group, which were higher than those in any of the rest groups (P < 0.05). In the follow-up stage of 6 months after treatment, there were 3 abnormal cases of ALT in the western medication group, but which was not different significantly as compared with the rest groups (P > 0.05).

CONCLUSION

Acupuncture and moxibustion combined with modified Mojie tablet effectively prevent from the recurrence of EMS after laparoscopic surgery and improve the life quality of the patients. This combined therapy brings less damage on the liver as compared with the western medication of gestrinone and indicates its definite efficacy and safety.

[Influence of feeding rumen-protected choline to transition dairy cows. Part 2: Health and reproduction]

OBJECTIVE

To determine the effects of rumen-protected choline (RPC) on health and reproduction in dairy cows.

MATERIAL AND METHODS

A total of 298 primi- and multiparous German Holstein cows of a high-production dairy herd (average daily milk yield: 32 l) were assigned randomly to a control or treatment group and were hand fed with 0 or 60 g/d of RPC as ReaShure®, respectively, from 21 days before expected calving to 21 days post partum (p. p.) as a top dressing. Health data was analyzed for the incidence of fever within the first 10 days in milk (DIM) as well as the incidence of diseases and the culling rate within the first 200 DIM. Reproduction data were evaluated in terms of the calving data, uterine involution on days 10, 21 and 42 p. p., uterine cytology at day 42 p. p., progesterone concentrations during weeks 3 and 5 p. p. and certain fertility measures. In the statistical analysis, it was differentiated between the control and treatment groups and between primi- and multiparous animals, and their interactions were analyzed.

RESULTS

The treatment group had less cows with subclinical endometritis, higher sickness rates after day 100 p. p., lower numbers of stillbirths and more cyclic cows in week 5 p. p. compared to the control group (p  <  0.05). Primipara in contrast to multipara had fever more frequently, higher rates of subclinical ketosis p. p., metritis and lameness, higher numbers of sick cows in the first 30 DIM, higher rates of stillbirths and dystocia, showed impaired involution of the uterus on day 10 p. p., fewer animals were cyclic during week 5 p. p. and less animals were culled (p < 0.05). Statistically significant interactions indicated that more heifers of the treatment group were lame, more heifers of the control group developed fever and subclinical endometritis, cows of the treatment group suffered more metritis and were sick more often in the first 30 DIM, and cows of the control group had more dystocia (p < 0.05).

CONCLUSION

Overall, supplementing RPC had only minor effects on the health status and reproduction. Further research in other dairy herds should focus on this topic.

Factors associated with the laterality of recurrent endometriomas after conservative surgery

We evaluated the laterality of primary endometrioma and characteristics of patients according to the laterality of recurrent endometrioma in 140 women with recurrent endometrioma after conservative surgery. Histologically confirmed recurrent endometriomas were found on the left side in 49 patients (35.0%), the right in 44 (31.4%) and bilaterally in 47 (33.6%). The sites of primary endometrioma were not associated with those of recurrent endometrioma, and the recurrence rate in the treated ovary (59.8%) was similar to that of the intact ovary (69.0%) at the primary surgery. Proportions of stage IV endometriosis and posterior cul-de-sac obliteration were higher in patients with bilateral recurrence than in those with unilateral recurrence (p < 0.01 for all comparisons) and in patients with contralateral recurrence than in those with ipsilateral recurrence (p < 0.05 for all comparisons), but no differences were found in other characteristics of participants according to the laterality or pattern of recurrence. In conclusion, the lateral distribution of recurrent endometrioma was not associated with that of the primary lesion, and endometrioma did not recur more frequently in the treated ovary. An advanced stage and the presence of posterior cul-de-sac obliteration were factors associated with bilateral or contralateral recurrence of endometrioma.

Dairy-food, calcium, magnesium, and vitamin D intake and endometriosis: a prospective cohort study

The etiology of endometriosis is poorly understood, and few modifiable risk factors have been identified. Dairy foods and some nutrients can modulate inflammatory and immune factors, which are altered in women with endometriosis. We investigated whether intake of dairy foods, nutrients concentrated in dairy foods, and predicted plasma 25-hydroxyvitamin D (25(OH)D) levels were associated with incident laparoscopically confirmed endometriosis among 70,556 US women in Nurses' Health Study II. Diet was assessed via food frequency questionnaire. A score for predicted 25(OH)D level was calculated for each participant. During 737,712 person-years of follow-up over a 14-year period (1991-2005), 1,385 cases of incident laparoscopically confirmed endometriosis were reported. Intakes of total and low-fat dairy foods were associated with a lower risk of endometriosis. Women consuming more than 3 servings of total dairy foods per day were 18% less likely to be diagnosed with endometriosis than those reporting 2 servings per day (rate ratio = 0.82, 95% confidence interval: 0.71, 0.95; P(trend) = 0.03). In addition, predicted plasma 25(OH)D level was inversely associated with endometriosis. Women in the highest quintile of predicted vitamin D level had a 24% lower risk of endometriosis than women in the lowest quintile (rate ratio = 0.76, 95% confidence interval: 0.60, 0.97; P(trend) = 0.004). Our findings suggest that greater predicted plasma 25(OH)D levels and higher intake of dairy foods are associated with a decreased risk of endometriosis.

Levonorgestrel-releasing intrauterine device (LNG-IUD) for symptomatic endometriosis following surgery

BACKGROUND

Various options exist for treating endometriosis, including surgical, medical, such as ovarian suppression, or a combination of these strategies. Surgical treatment of endometriosis aims to remove visible areas of endometriosis. The aim of medical therapy is to inhibit growth of endometriotic implants by induction of a hypo-estrogenic state. Treatment with a hormone-releasing intrauterine device, using levonorgestrel (LNG-IUD), has also been suggested.

OBJECTIVES

To determine whether postoperative LNG-IUD insertion in women with endometriosis improves pain and reduces recurrence of symptoms compared with no postoperative treatment, postoperative insertion of a placebo, or postoperative therapy.

SEARCH METHODS

The following databases were searched from inception to June 2012: Cochrane Menstrual Disorders and Subfertility Group Specialised Register of controlled trials, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, CINAHL, and the World Health Organization (WHO) International Clinical Trials Registry Platform. EMBASE was searched from 2010 to June 2012. The citation lists of relevant publications, review articles, abstracts of scientific meetings, and included studies were also searched.

SELECTION CRITERIA

Trials were included if they compared women undergoing surgical treatment for endometriosis with uterine preservation and then randomised within three months to LNG-IUD insertion versus no postoperative treatment, placebo (inert IUD), or other treatment. Diagnostic laparoscopy alone was not considered suitable treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted data to allow for an intention-to-treat analysis. For dichotomous data, the risk ratio (RR) and 95% confidence interval (CI) were calculated using the Mantel-Haenszel random-effects method. For continuous data, the mean difference (MD) and 95% CI were calculated using the inverse variance random-effects method.

MAIN RESULTS

Three randomised controlled trials were included. In two trials, there was a statistically significant reduction in the recurrence of painful periods in the LNG-IUD group compared with expectant management (RR 0.22, 95% CI 0.08 to 0.60, 95 women, I(2) = 0%, moderate strength of evidence). The proportion of women who were satisfied with their treatment was also higher in the LNG-IUD group but did not reach statistical significance (RR 1.21, 95% CI 0.80 to 1.82, 95 women, I(2) = 0%). The number of women reporting a change in menstruation was significantly higher in the LNG-IUD group (RR 37.80, 95% CI 5.40 to 264.60, 95 women, I(2) = 0%) but the number of women not completing the allocated treatment did not differ between groups (RR 0.66, 95% CI 0.08 to 5.25, I(2) = 43%).In one trial, women receiving LNG-IUD noted lower pain scores compared with women receiving gonadotrophin-releasing hormone agonists (MD -0.16, 95% CI -2.02 to 1.70, 40 women) but this did not reach statistical significance.

AUTHORS' CONCLUSIONS

There is limited but consistent evidence showing that postoperative LNG-IUD use reduces the recurrence of painful periods in women with endometriosis. Further well-designed RCTs are needed to confirm these findings.

Curcumin delays endometriosis development by inhibiting MMP-2 activity

Endometriosis is a common reproductive disorder believed to be associated with matrix metalloproteinases (MMPs) activities for invasion and remodeling of endometrial tissues. Ectopic endometrium has higher capacity to produce proMMP-2 than eutopic tissues; however, the role of MMP-2 during early phase of endometriosis development is still unclear. In the present study, we investigated the role of MMP-2 in establishment and development of endometriosis in mouse model. The effect of curcumin on regression of endometriosis through protease/antiprotease balance between MMP-2 and TIMP-2 was also examined. After endometrial inoculation into peritoneum, we observed a significant elevation of proMMP-2 activity from day 2 onwards. This increased MMP-2 activity was associated with decreased expression of tissue inhibitor of MMP (TIMP)-2, while a significant up-regulation of active MMP-2 activity was observed from day 3 onwards. The activation of proMMP-2 to active MMP-2 was associated with increased expression of membrane type 1 matrix metalloproteinase (MT1MMP). Curcumin at a dose of 48 mg/kg b.w. repressed the MMP-2 activity via up-regulation of bound TIMP-2 expression, thus delayed endometriosis development. In addition, curcumin inhibited production of active MMP-2 by down-regulating MT1MMP expression. Moreover, endometriotic progression was directly linked with increased MMP-2/TIMP-2 ratio which was delayed by curcumin pretreatment. In summary, our study documents the regulation of MMP-2 activity by TIMP-2 during the early phase of endometriosis development and inhibitory action of curcumin thereon.

Macrophage migration inhibitory factor antagonist blocks the development of endometriosis in vivo

Endometriosis, a disease of reproductive age women, is a major cause of infertility, menstrual disorders and pelvic pain. Little is known about its etiopathology, but chronic pelvic inflammation is a common feature in affected women. Beside symptomatic treatment of endometriosis-associated pain, only two main suboptimal therapeutic approaches (hormonal and invasive surgery) are generally recommended to patients and no specific targeted treatment is available. Our studies led to the detection of a marked increase in the expression of macrophage migration inhibitory factor (MIF) in the eutopic endometrium, the peripheral blood and the peritoneal fluid of women with endometriosis, and in early, vascularized and active endometriotic lesions. Herein, we developed a treatment model of endometriosis, where human endometrial tissue was first allowed to implant into the peritoneal cavity of nude mice, to assess in vivo the effect of a specific antagonist of MIF (ISO-1) on the progression of endometriosis and evaluate its efficacy as a potential therapeutic tool. Administration of ISO-1 led to a significant decline of the number, size and in situ dissemination of endometriotic lesions. We further showed that ISO-1 may act by significantly inhibiting cell adhesion, tissue remodeling, angiogenesis and inflammation as well as by altering the balance of pro- and anti-apoptotic factors. Actually, mice treatment with ISO-1 significantly reduced the expression of cell adhesion receptors αv and ß3 integrins (P<0.05), matrix metalloproteinases (MMP) 2 and 9 (P<0.05), vascular endothelial cell growth factor (VEGF) (P<0.01), interleukin 8 (IL8) (P<0.05), cyclooxygenease (COX)2 (P<0.001) and the anti-apoptotic protein Bcl2 (P<0.01), but significantly induced the expression of Bax (P<0.05), a potent pro-apoptotic protein. These data provide evidence that specific inhibition of MIF alters endometriotic tissue growth and progression in vivo and may represent a promising potential therapeutic avenue.

[Medical treatment of endometriosis: an obligation rather than a mere option!]

The aim of this article is to argue the usefulness of the systematic administration of medical treatment in women managed for endometriosis, either alone or associated with the surgery. The authors dispute seven frequent objections against the medical treatment: the lack of curative effect, the lack of primary prevention and the risk of delaying the diagnostic, the contraceptive effect in women wishing to conceive, the adverse effects, the risk of occurrence of new lesions following the arrest of the treatment, the lack of proof favourable to the efficient prevention of recurrences and the cost of the treatment. The authors conclude that to date the therapeutic amenorrhea represents an indispensable tool in the management of the endometriosis, in women both benefiting or not from surgical procedures.

Activation of mutated K-ras in donor endometrial epithelium and stroma promotes lesion growth in an intact immunocompetent murine model of endometriosis

Endometriosis is a common chronic gynaecological condition, affecting 5-10% of women of child-bearing age. Its study has been hampered by lack of genetically tractable models. We transplanted steroid-manipulated, menstrual-like endometrium from K-ras(G12V/+) /Ah-Cre(+/+) /ROSA26R-LacZ(+/+) mice into gonad-intact immunocompetent wild-type mice. This led to endometriosis-like lesion development. Long-term lesion survival depended on the presence of the activated K-ras in the small proportion of the cells in the mature lesion that had undergone Cre-mediated K-ras activation. LacZ activity demonstrated Cre-mediated recombination in both endometrial epithelial cells and stromal cells, and transgenic K-ras expression was confirmed by RT-PCR. The endometriosis lesions developed without exogenous oestradiol supplementation and anti-oestrogen (fulvestrant, ICI 182780) treatment greatly suppressed their growth. Immunohistochemistry confirmed that as in human endometriosis, there was invasion and activation of fibroblasts, endothelial cells, and macrophages, with marked collagen deposition in the lesions. This model provides an opportunity to investigate endometriosis lesion establishment, growth, and regression in genetically tractable, immunocompetent, and hormonally intact mice. Furthermore, for the first time it provides a suitable model to test clinically validated driver genes in a faithful mouse model of the predisposing endometriotic lesion, thus providing the correct cellular context and microenvironment for ovarian clear cell carcinogenesis.

Peroxisome proliferator-activated receptor-(gamma) receptor ligand partially prevents the development of endometrial explants in baboons: a prospective, randomized, placebo-controlled study

A prospective, randomized, placebo-controlled study was conducted in a baboon model to determine if a thiazolidinedione agonist of peroxisome proliferator-activated receptor-gamma, pioglitazone, can impede the development of endometriosis. Endometriosis was induced using laparoscopic, intrapelvic injection of eutopic menstrual endometrium, previously incubated with placebo or pioglitazone for 30 min, in 12 female baboons with a normal pelvis that had undergone at least one menstrual cycle since the time of captivity. At this point, the 12 baboons were randomized into two groups and treated from the day of induction. They received either PBS tablets (n = 6, placebo control, placebo tablets once a day by mouth) or pioglitazone (n = 6, test drug, 7.5 mg by mouth each day). A second and final laparoscopy was performed in the baboons to record the extent of endometriotic lesions between 24 and 42 d after induction (no difference in length of treatment between the two groups, P = 0.38). A videolaparoscopy was performed to document the number and surface area of endometriotic lesions. The surface area and volume of endometriotic lesions were significantly lower in pioglitazone treated baboons than the placebo group (surface area, 48.6 vs. 159.0 mm(2), respectively, P = 0.049; vol, 23.7 vs. 131.8 mm(3), respectively, P = 0.041). The surface area (3.5 vs. 17.8 mm(2), P = 0.017, pioglizatone vs. placebo) and overall number (1.5 vs. 9.5, P = 0.007, pioglizatone vs. placebo) of red lesions were lower in the pioglitazone group. A peroxisome proliferator-activated receptor-gamma ligand, pioglitazone, effectively reduced the initiation of endometriotic disease in the baboon endometriosis model. Using this animal model, we have shown that thiazolidinedione is a promising drug for preventive treatment of endometriosis.

Adult physical activity and endometriosis risk

BACKGROUND

Regular exercise has been associated with a 40%-80% reduction in risk for endometriosis in several case-control studies. However, women experiencing symptoms prior to their diagnosis may be less likely to exercise than healthy controls, thus biasing the observed association.

METHODS

Using data collected from the Nurses' Health Study II, a prospective cohort study of premenopausal US nurses that began in 1989, we have attempted to clarify this relation. Data are updated every 2 years with follow-up for these analyses through 2001. In 1989, 1991, and 1997 women reported average amount of time per week engaging in various physical activities. A metabolic equivalent (MET) score was assigned to each activity, and these were summed to estimate total activity.

RESULTS

A total of 102,197 premenopausal women contributed 996,422 person-years of follow-up with 2703 cases of laparoscopically confirmed endometriosis. After adjusting for BMI at age 18, current BMI, smoking, parity, infertility status, oral contraceptive use, age at menarche, and menstrual cycle length and pattern in college, we observed only a slight reduction in the incidence of endometriosis, comparing the highest level of activity (>or=42 MET hours/week) to the lowest (<3 MET hours/week) (rate ratio = 0.89 [95% confidence interval = 0.77-1.03]). The association was limited to participants with no past or concurrent infertility (P = 0.002, test for heterogeneity). No associations were seen with inactivity.

CONCLUSIONS

In this first prospective assessment, we did not find evidence of the strong inverse association previously reported, although we cannot rule out a modest inverse association.

Perioperative antibiotic prophylaxis for nonlaboring cesarean delivery

OBJECTIVE

To estimate the efficacy of antibiotic prophylaxis at the time of nonlaboring cesarean delivery in reducing postpartum infection-related complications.

METHODS

We performed a secondary analysis of an observational study of cesarean deliveries performed at 13 centers from 1999-2000. Patients were included if they had cesarean delivery before labor, did not have intrapartum infection, and were not given antibiotics at delivery for reasons other than prophylaxis. The occurrence of postpartum endometritis, wound infection, and other, less common infection-related complications was compared between those who did and did not receive antibiotic prophylaxis. Results were adjusted for smoking, payer status, gestational age and body mass index at delivery, race, diabetes, antepartum infections, presence of anemia, operative time, type of cesarean delivery (primary or repeat), and center.

RESULTS

Of the 9,432 women who met study criteria, the 6,006 (64%) who received antibiotic prophylaxis were younger, heavier at delivery, and were more likely to be African American, receive public insurance, and have diabetes. Patients who received antibiotic prophylaxis were less likely to develop postpartum endometritis (121 [2.0%] compared with 88 [2.6%], adjusted odds ratio [OR] 0.40, 95% confidence interval [CI] 0.28-0.59) or wound infection (31 [0.52%] compared with 33 [0.96%], adjusted OR 0.49, 95% CI 0.28-0.86).

CONCLUSION

Antibiotic prophylaxis at the time of nonlaboring cesarean delivery significantly reduces the risks of postpartum endometritis and wound infection.

LEVEL OF EVIDENCE

III.

Endometriosis and the role of reproductive medicine

Endometriosis is a complex trait with significant environmental and genetic influences that are likely to affect its phenotype. Natural history of the disease varies from one individual to another. The gold standard of surgical diagnosis is limited in accuracy by visibility and recognition of lesions by the attending surgeon. Several lines of evidence suggest that pelvic endometriosis results from the reflux of viable endometrial tissue through the fallopian tubes. Endometriosis is an inflammatory disease that nuclear factor kappa B pathway may play an important role in its pathogenesis. Endometriotic lesions demonstrate increased aromatase expression in association with increased cyclo-oxygenase-2 expression, especially in red lesions which represent earlier stages of inflammation. Estrogen and progesterone receptor expressions vary according to the morphology and the inflammatory status of the endometriotic lesions. Normal endometrial tissue fragments can adhere and implant to peritoneum. Aromatase expression, a possible intrinsic survival factor for endometrial tissue, is inducible in human endometrial fragments by androstenedione at physiological concentrations found in peritoneal fluid. Inflammatory response to ectopic endometrial tissue, which may vary in each individual seems to be important in disease progression. Current therapies for endometriosis include surgical and medical approaches aimed at cytoreduction or hormonal suppression. However, the disease have tendency to recur in many symptomatic women. Although new management approaches are emerging, properly designed clinical trials are desperately needed in treatment of pain and subfertility associated with endometriosis. Future studies should also focus on identifying risk population to develop preventive strategies, since the treatment of endometriosis is costly and challenging.

Simvastatin protects against the development of endometriosis in a nude mouse model

CONTEXT

Endometriosis is a common condition associated with infertility and pelvic pain in women. Recent in vitro studies have shown that statins decrease proliferation of endometrial stroma (ES) and inhibit angiogenesis.

OBJECTIVE

The aim was to evaluate effects of simvastatin on development of endometriosis in a nude mouse model.

METHODS

Proliferative phase human endometrial biopsies were obtained from healthy donors and established as organ cultures or used to isolate ES cells. To establish endometriosis in the nude mouse, endometrial tissues were maintained in 1 nm estradiol (E) for 24 h and subsequently injected into ovariectomized nude mice. Mice (n = 37) were treated with E (8 mg, SILASTIC capsule implants; made in author laboratory) alone or with E plus simvastatin (5 or 25 mg/kg x d) for 10 d beginning 1 d after tissue injection (from three donors). Mice were killed and examined for disease. Effects of simvastatin on matrix metalloproteinase-3 (MMP-3) were evaluated in cultures of ES cells.

PRIMARY OUTCOME

The number and size of endometriotic implants were measured.

RESULTS

Simvastatin induced a dose-dependent decrease of the number and size of endometrial implants in mice. At the highest dose of simvastatin, the number of endometrial implants decreased by 87%, and the volume by 98%. Simvastatin also induced a concentration-dependent decrease in MMP-3 in the absence and presence of inflammatory challenge (using IL-1alpha).

CONCLUSIONS

Simvastatin exerted a potent inhibitory effect on the development of endometriosis in the nude mouse. Mechanisms of action of simvastatin may include inhibition of MMP-3. The present findings may lead to the development of novel treatments of endometriosis involving statins.

Vaginal parturition decreases recurrence of endometriosis

OBJECTIVE

To evaluate the role of parturition in the recurrence of endometriosis.

DESIGN

Retrospectively analyzed, prospectively obtained data.

SETTING

Unit of Physiopathology of Reproduction, Health Care Unit of Rimini, and University of Bologna Cervesi General Hospital, Cattolica, Italy.

PATIENT(S)

Three hundred forty-five patients with stage II-IV endometriosis, dysmenorrhea, and infertility were treated for endometriosis and divided into four groups according to parity and mode of parturition.

INTERVENTION(S)

The patients were laparoscopically treated for endometriosis upon the occurrence and recurrence of the disease. Ultrasound measurements of the uterine internal ostium (IOS) were performed at each study interval.

MAIN OUTCOME MEASURE(S)

Degree of dysmenorrhea, occurrence and recurrence of endometriosis, and uterine IOS measurements were established and related to parity and mode of parturition.

RESULT(S)

After parturition, dysmenorrhea recurrence was significantly higher in nulliparous women than in women with vaginal parturition. The endometriosis recurrence rate was higher in women who did not have vaginal parturition. The IOS significantly enlarged after vaginal delivery but not after cesarean delivery. There were significant negative correlations between IOS and the recurrence of endometriosis and dysmenorrhea. Odds ratios indicated that as the IOS enlarged, the risk of recurrence decreased.

CONCLUSION(S)

Vaginal parturition plays a protective role in the recurrence of endometriosis.

The role of iron in the pathogenesis of endometriosis

BACKGROUND

Endometriosis may cause symptoms including chronic pelvic pain and infertility, and increases susceptibility to the development of ovarian cancer. Genomic studies have started to delineate the wide array of mediators involved in the development of endometriosis. Understanding the mechanisms of endometriosis development and elucidating its pathogenesis and pathophysiology are intrinsic to prevention and the search for effective therapies.

METHOD OF STUDY

The present article reviews the English language literature for biological, pathogenetic and pathophysiological studies on endometriosis. Several recent genomic studies are discussed in the context of endometriosis biology.

RESULTS

Severe hemolysis occurring during the development of endometriosis results in high levels of free heme and iron. These compounds oxidatively modify lipids and proteins, leading to cell and DNA damage, and subsequently fibrosis development. Recent studies based on genome-wide expression analysis technology have noted specific expression of heme/iron-dependent mediators in endometriosis. The heme/iron-dependent signaling pathway of endometriosis, which is providing new insights into the regulation of inflammation, detoxification and survival, is discussed.

CONCLUSION

Several important endometriosis-specific genes overlap with those known to be regulated by iron. Other genes are involved in oxidative stress. Iron has a significant impact on endometriotic-cell gene expression. This review summarizes recent advances in the heme/iron-mediated signaling and its target genes, outlines the potential challenges to understanding of the pathogenesis and pathophysiology of endometriosis, and proposes a possible novel model.

[Preventive and therapeutic effect of E-leng capsule on post-operation recurrence of ovarian endometriotic cysts and its influence on expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in eutopic and ectopic endometrium]

OBJECTIVE

To investigate the effect and mechanism of E-leng Capsule (ELC) in preventing and treating post-operation recurrence of ovarian endometriotic cysts (OEC).

METHODS

A total of 60 patients enrolled were the inpatients, who underwent cystectomy of OEC in the Gynecological Department of Guangdong Provincial Hospital of Traditional Chinese Medicine from 2002 to 2004. They were randomly assigned to two groups, the treatment group and the control group. Patients in the treatment group were administered with ELC before operation and after operation (starting from the 7th day post-operation), each for 3 months, while patients in the control group were untreated before operation and administered with Danazol from the 7th day post-operation for 3 months. Specimens of eutopic and ectopic endometrium in all patients of both groups were taken during the operation for detecting expressions of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNA by polymerase chain reaction (PCR), and the incidence of post-operation recurrence was observed 12 months later.

RESULTS

The 12-month follow-up showed that recurrence presented in 1 patient in the treatment group (3.3%), and 6 in the control group (20.0%), showing significant difference between them (P<0.05). The expressions of TIMP-1 mRNA in eutopic and ectopic endometrium were 0.85 +/- 0.36 and 0.76 +/- 0.57 in the treatment group, and 0.71 +/- 0.33 and 0.56 +/- 0.39 in the control group, while the expressions of MMP-9 mRNA were 0.36 +/- 0.40 and 0.35 +/- 0.35 vs 0.36 +/- 0.33 and 0.72 +/- 0.59, respectively. The expression of endometrial TIMP-1 mRNA, either eutopic or ectopic, was significantly higher, and the expression of ectopic endometrial MMP-9 mRNA was lower in the treatment group than that in the control group (P<0.01).

CONCLUSION

ELC can reduce the invasive ability of endometrium tissue probably by regulating the balance of MMP/TIMP, namely, increase the expression of eutopic and ectopic endometrial TIMP-1 and decrease the expression of ectopic endometrial MMP-9, and thus to achieve its preventive and therapeutic effect on recurrence of OEC.

Role of melatonin in regulating matrix metalloproteinase-9 via tissue inhibitors of metalloproteinase-1 during protection against endometriosis

Endometriosis is a gynecological disease of women and plausibly regulated by matrix metalloproteinases (MMPs). However, mechanisms of alterations in MMPs during endometriosis remain unclear. Human endometriotic tissues possessing varying degrees of severity were examined for expression of MMPs and tissue inhibitors of metalloproteinase (TIMP)-1. In addition, endometriosis was generated in mice and endometriotic tissues were tested for MMP-9 activity. Results show significant upregulation of secreted and synthesized proMMP-9 activity with duration and severity of endometriosis. Along with upregulation of activity, the expression of proMMP-9 was found increased while TIMP-1 expression followed an inverse trend. The effect of melatonin, a major secretory product of the pineal gland, on endometriosis was examined in preventive and therapeutic models in mice. The results show that melatonin arrested lipid peroxidation and protein oxidation and downregulated proMMP-9 activity and expression in a time and dose-dependent manner while protecting and regressing peritoneal endometriosis. Moreover, the attenuated activity and expression of proMMP-9 were associated with subsequent elevation in the expression of TIMP-1. Our study reveals for the first time the role of melatonin in arresting peritoneal endometriosis in mice and a novel marker, expression ratio of proMMP-9 versus TIMP-1, was identified for assessing severity and progression of endometriosis.

Lifting the curse

Adenomyosis is a condition most women have never heard of. Yet it can cause severe menstrual cramping and heavy bleeding.

Effects of a protein kinase C inhibitor on the initial development of ectopic implants in a syngeneic mouse model of endometriosis

OBJECTIVE

To evaluate the effect of protein kinase C inhibition on surgically induced endometriosis in mice.

DESIGN

Prospective, randomized study.

SETTING

Academic facility.

ANIMALS

Sixty adult female C57BJ6 mice.

INTERVENTION(S)

On day -7, oral gavage of a vehicle alone or of a protein kinase C inhibitor (100 mg/kg/day, once a day) was started and continued for 1 week in donor groups A and B, respectively. On day 0, uterine fragments from donor group A were implanted into recipient mice. Recipient mice were divided randomly into two groups: group 1 (vehicle) and group 2 (protein kinase C inhibitor). Uterine fragments from donor group B were implanted into recipient mice, and they were divided randomly into two groups: group 3 (vehicle) and group 4 (protein kinase C inhibitor). Oral gavage of a protein kinase C inhibitor (100 mg/kg/day, once a day) or vehicle was continued for 1 week.

MAIN OUTCOME MEASURE(S)

Presence and number of ectopic implants.

RESULT(S)

The number of mice that developed ectopic implants was significantly lower in groups 3 (40%) and 4 (30%) than in group 1 (100%). The number of ectopic implants was significantly lower in groups 2, 3, and 4 than in group 1.

CONCLUSION(S)

Protein kinase C inhibitor use partially prevented the development of ectopic implants in a mouse model of endometriosis.

Genistein causes regression of endometriotic implants in the rat model

OBJECTIVE

To determine the effects of raloxifene and genistein on experimentally induced endometriosis in a rat model.

DESIGN

Prospective, randomized animal study.

SETTING

Animal surgery laboratory in a university hospital.

ANIMAL(S)

Thirty-three adult, mature female Wistar-Albino rats in which endometriotic implants were induced by transplanting autologous uterine tissue to ectopic sites on the peritoneum.

INTERVENTION(S)

After the endometriotic implants were formed surgically, the 33 rats were randomly divided into three groups. Group 1 (genistein group, 10 rats) were given 500 mg/kg per day of oral genistein. Group 2 (raloxifene group, 10 rats) were given 10 mg/kg per day of oral raloxifene. Group 3 were given no medication and served as controls (13 rats). All the rats continued to receive treatment for 21 days, and then were killed to assess the implants' size and for histologic examination.

MAIN OUTCOME MEASURE(S)

The surface area of the endometriotic implants and the score of histologic analysis.

RESULT(S)

At the beginning of the medical treatment, the mean surface areas of the endometriotic implants were comparable in all three groups. At the end of the medical treatment, the mean surface area of implants in groups 1 and 2 was smaller than that of implants in the control group. The decrease in the surface area of the endometriotic implants was greater in group 1 and group 2 than found in the control group. The histologic assessment revealed that the mean of the histopathologic score of the implants at the end of the treatment was lower in groups 1 and 2 when compared with the control group.

CONCLUSION(S)

Genistein caused a statistically significant regression of endometriotic implants.

PPAR-gamma receptor ligand induces regression of endometrial explants in baboons: a prospective, randomized, placebo- and drug-controlled study

OBJECTIVE

To determine the effects of a thiazolidinedione (TZD) agonist of peroxisome proliferator-activated receptor (PPAR)-gamma, rosiglitazone, in a baboon model of established endometriosis.

DESIGN

Prospective, randomized, placebo-controlled study.

SETTING

Experimental surgery laboratory at the Institute of Primate Research in Nairobi, Kenya.

ANIMAL(S)

Endometriosis was induced using intrapelvic injection of eutopic menstrual endometrium in 12 female baboons with a normal pelvis that had undergone at least one menstrual cycle since the time of captivity.

INTERVENTION(S)

Induction of endometriosis by laparoscopy was performed in 12 baboons with a normal pelvis. Endometrial tissue was extracted from each baboon by curettage, and a standard amount of endometrium was then seeded onto several peritoneal sites. About 34-68 days after the induction of laparoscopy, a pretreatment laparoscopy (baseline disease assessment) was performed in the baboons to record the extent of endometriotic lesions. The 12 baboons were randomized into three groups and treated from the day after the staging laparoscopy for a total duration of 30 days. They received phosphate-buffered saline tablets (n = 4, placebo control; placebo tablets once a day by mouth for 30 days), GnRH-antagonists (n = 4, active control; ganirelix acetate 125 microg/day for 30 days), or rosiglitazone (n = 4, test drug, 2 mg by mouth each day for 30 days). A third and final laparoscopy on day 30 after the start of treatment was performed to record the extent of endometriosis. The type of lesion (typical, red, white, or suspicious) was recorded. Biopsies were obtained to confirm the histological presence of endometriosis.

MAIN OUTCOME MEASURE(S)

A videolaparoscopy was performed 30 days after treatment to document the number and surface area of endometriotic lesions as well as to calculate the revised American Society for Reproductive Medicine score and stage.

RESULT(S)

The surface area of endometriotic lesions was statistically significantly lower in rosiglitazone-treated baboons when compared with the placebo group. Baboons treated with rosiglitazone or ganirelix had a greater negative relative change in surface area of peritoneal endometriotic lesions than controls. The overall weighted appearance of the lesion types suggests that rosiglitazone may deter the development of newer endometriotic lesions.

CONCLUSION(S)

A PPAR-gamma ligand, rosiglitazone, effectively diminishes the burden of endometriosis disease in a baboon endometriosis model. This animal model holds promise that a TZD drug may be helpful in women with endometriosis.

Effect of soy isoflavones on endometriosis: interaction with estrogen receptor 2 gene polymorphism

BACKGROUND

Progression of endometriosis is considered estrogen-dependent. Dietary soy isoflavones may affect the risk of endometriosis, and polymorphisms in estrogen receptor genes may modify this association. We examined associations among soy isoflavone intake, estrogen receptor 2 (ESR2) gene polymorphisms and risk of endometriosis.

METHODS

We recruited women age 20-45 years old who had consulted a university hospital for infertility in Tokyo, Japan in 1999 or 2000. A total of 138 eligible women were diagnosed laparoscopically and classified into 3 subgroups: control (no endometriosis), early endometriosis (stage I-II) and advanced endometriosis (stage III-IV). We measured urinary levels of genistein and daidzein as markers for dietary intake of soy isoflavones, and genotyped ESR2 gene RsaI polymorphisms.

RESULTS

Higher levels of urinary genistein and daidzein were associated with decreased risk of advanced endometriosis (P for trend = 0.01 and 0.06, respectively) but not early endometriosis. For advanced endometriosis, the adjusted odds ratio for the highest quartile group was 0.21 (95% confidence interval = 0.06-0.76) for genistein and 0.29 (0.08-1.03) for daidzein, when compared with the lowest group. Inverse associations were also noted between urinary isoflavones and the severity of endometriosis (P for trend = 0.01 for genistein and 0.07 for daidzein). For advanced endometriosis, ESR2 gene RsaI polymorphism appeared to modify the effects of genistein (P for interaction = 0.03).

CONCLUSIONS

Dietary isoflavones may reduce the risk of endometriosis among Japanese women.