Luminal Epithelial Cell Height Research Articles

A Causal Link Between Disrupted AKT Signaling and Hyperproliferative Endometrial Diseases.

Most endometrial diseases are hyperproliferative and caused by excessive estradiol (E2) signaling, diminished progesterone (P4) signaling, or both. By example, endometriosis, adenomyosis, and type I endometrial cancer are all driven by excessive E2 exposure or aberrant estrogen receptor (ESR1) signaling. Endometriosis is also commonly associated with P4 resistance in which ectopic endometriotic lesions and eutopic endometrium have abnormally low expression of progesterone receptor (PGR). While it is well established that genomic events coordinate many of the most profound and well-studied sex steroid-initiated actions in the endometrium, activation of intracellular phosphorylation cascades, production of rapid calcium transients, changes to luminal epithelial cell height, and edema occur much too rapidly to be caused by the classical pathway, which involves transcription and translation. Work from several laboratories over the past 2 decades has revealed the importance of rapid acting steroid hormone signaling collectively called non-classical signaling. By example, P4 signals rapidly through PGR that is tethered to the plasma membrane by palmitoylate lipid moieties and this activates several phosphorylation cascades (1). Some non-classical E2 signaling events are thought to be mediated by membrane bound ESR1 (mESR1) and mESR2 (1). It is now clear that membrane bound forms of sex steroid receptors (ie, ESR1/2, PGR, androgen receptor) potentiate the actions of their soluble cytosolic/nuclear receptor equivalents through activation of phosphorylation cascades (1, 2). Such phosphorylation cascades result in selective phosphorylation of cytosolic/nuclear isoforms, and this in turn enhances/reduces protein-protein interactions with transcriptional co-activators/repressors to fine-tune genomic responses.

Effects of melatonin on uterine hypertrophy/hyperplasia: A preliminary experimental rat study

Endometrial hyperplasia is a process of endometrial proliferation that results in a thickening of the endometrial tissue. Melatonin might be able to change the pathophysiological process and prognosis into a positive way that might prevent and heal endometrial hyperplasia, which is the first stage of endometrial cancer.For this perspective, we tried to investigate the effect of melatonin on uterine hypertrophy/hyperplasia in an experimental rat model. Forty Wistar-Albino rats were undergone bilateral oophorectomy and randomized into four groups. To create a model of uterine hypertrophy/hyperplasia in all groups, except the control group [C] (n = 10), 4 mg/kg/day estradiol hemihydrate were given for 14 days. The uterine hypertrophy/hyperplasia was evaluated histopathologically in the left uterine horns, then the groups were treated for 14 days as follows; melatonin (10 mg/kg/day/po) [M] (n = 10), melatonin + estradiol hemihydrate (10 mg/kg/day/po and 4 mg/kg/day/po) [M + E] (n = 10), and dark environment [D] (n = 10). Finally, the effects of the melatonin were examined histopathologically in the right uterine horns.An uterine hypertrophy/hyperplasia model was established in all groups compared to the control group (p < 0.05). In the [M] and [M + E] groups, epithelial cell height and luminal epithelial cell height significantly decreased (41μm vs 12μm, p = 0.005; 14μm vs 10μm, p = 0.005, respectively for [M] group) and (32μm vs 14μm, p = 0.012; 17μm vs 10μm, p = 0.017, respectively for [M + E] group). The [D] group exhibited a significant decrease in epithelial cell height (33μm vs 20μm, p = 0.017).With or without estrogen exposure, melatonin-treated and physiologically melatonin-released rats experienced a significant uterine hypertrophy/hyperplasia recovery. Melatonin may have protective effects on endometrial hyperplasia.

Estrogenic Effect of Salvia officinalis Extract on Reproductive Function of Female Mice and Identification of Its Phenolic Content.

Natural Phytoestrogens present in plants are effective hormonal replacement therapy. They are converted to estrogenic substances in the gastrointestinal tract, which is considered as the natural alternative to estrogen substitute treatment for postmenopausal women. Salvia officinalis, a herb traditionally used to ameliorate postmenopausal complications, can provide a safe alternative to synthetic pharmaceuticals for the treatment of menopause. Therefore, it is conceivable to detect the possible estrogenic effect of Salvia Officinalis extract as an estrogen replacement therapy in female mice. Phytochemical, pharmacological, and immune histopathological techniques are adopted in this study. HPLC is used for the identification of extracted constituents of sage herb. The uterotrophic activity of the extract was determined in immature female mice. Moreover, the mean thickness and luminal epithelium and the photomicrographs of the luminal epithelium of the uterus were also studied. HPLC revealed that quercetin is the major extracted constituent (28.6%) of the total components. Saliva officinalis extract produced a significant increase in the uterine dry weight of equal potency to estrogen. The uterus exhibited a significant increase in luminal epithelial cell height (43.3 ± 6.1μm and 36.5 ± 2.5μm) for estradiol and sage extract, respectively, compared with the control group (18.2 ± 3.5μm). Furthermore, the endometrium showed the lining epithelium formed of a single layer of columnar epithelium. The stroma seemed more voluminous with dilated vasculature. Conversely, the myometrium within the uterus was not affected in any of the experimental groups. The sage herbs induced proliferative changes in the uteri of treated mice, which suggest possible estrogenic properties. Saliva officinalis extract can be used as a hormonal replacement for women during menopause and could be further explored for contraceptive use.

Non-Ionizing Radiation Created by Mobile Phone Progresses Endometrial Hyperplasia: An Experimental Rat Study

Non-ionizing radiation is related with many pathologies. Determine association between non-ionizing radiation and endometrial hyperplasia. Fifty oopherectomized Wistar albino rats were administered Estradiol hemihydrate (4mg/kg) to induce hyperplasia, and were exposed to 1800MHz radiation created by a mobile phone and a signal generator working as base station. This study was carried out with 5 groups in two phases. The study groups were. Control group without any exposure; group receiving estrogen in first phase of the study; group receiving estrogen in both phases; group receiving estrogen in the first phase and exposed to non-ionizing radiation during second phase and group taking estrogen in both phases and exposed to non-ionizing radiation during the second phase. Following both phases, uterine horns were excised and evaluated based on glandular density (GD), epithelial cell height (ECH), and luminal epithelial cell height (LECH). Estrogen increased all parameters during both phases (LECH, GD, and ECH values were 12,2 vs. 16,5 (p=0.001), 34 vs. 47 (p <0.001), and 201 vs. 376.6 (p=0.001), respectively during the first phase; LECH, GD and ECH values were 13,2 vs. 20,3 (p <0.001), 35.5 vs. 65,5 (p <0.001), 219.9 vs. 419.6 (p <0.001), respectively, during the second phase).Non-ionizing radiation increased all values without estrogen exposure (LECH, GD and ECH values were 13,2 vs. 17,2 (p=0,074), 35,5 vs. 59 (p=0.074), and 219 vs. 318.3 (p <0.001), respectively) or with estrogen exposure (LECH, GD, and ECH, values were 20,3 vs. 22,8 (p=0,168), 65,5 vs. 77 (p=0,058), and 419,6 vs. 541,6 (p=0.004), respectively). Non-ionizing radiation progressed endometrial hyperplasia in an experimental rat model with/without estrogen exposure.

Chronic Low-Dose Nonylphenol or Di-(2-ethylhexyl) Phthalate has a Different Estrogen-like Response in Mouse Uterus.

Through the development of organic synthetic skill, chemicals that mimic signaling mediators such as steroid hormones have been exposed to the environment. Recently, it has become apparent that this circumstance should be further studied in the field of physiology. Estrogenic action of chronic low-dose nonylphenol (NP) and di-(2-ethylhexyl) phthalate (DEHP) in mouse uterus was assessed in this study. Ten to twelve-week-old female mice (CD-1) were fed drinking water containing NP (50 or 500 μg/L) or DEHP (133 or 1,330 μg/L) for 10 weeks. Uterine diameter, the thickness of myometrium and endometrium, and the height of luminal epithelial cells were measured and the number of glands were counted. The expression levels of the known 17β-estradiol (E2)-regulated genes were evaluated with real-time RT-PCR methodology. The ration of uterine weight to body weight increased in 133 μg/L DEHP. Endometrial and myometrial thickness increased in 133 and 1,330 μg/L DEHP treated groups, and in 50, 500 μg/L NP and 133 μg/L DEHP, respectively. The height of luminal epithelial cell decreased in NP groups. The numbers of luminal epithelial gland were decreased in NP groups but increased in 50 μg/L DEHP group. The histological characters of glands were not different between groups. The mRNA expression profiles of the known 17β-estradiol (E2) downstream genes, Esr1, Esr2, Pgr, Lox, and Muc1, were also different between NP and DEHP groups. The expression levels dramatically increased in some genes by the NP or DEHP. Based on these results, it is suggested that the chronic low-dose NP or DEHP works as estrogen-like messengers in uterus with their own specific gene expression-regulation patterns.

Ginkgo biloba extract (EGb761) did not express estrogenic activity in an immature rat uterotrophic assay

Ginkgo biloba is a dioecious tree that has been used in traditional Chinese medicine for about 5,000 years. In previous studies on Ginkgo biloba extract (EGb761) using in vitro systems, we confirmed that EGb761 has biphasic effects on estrogenicity. In this study, we evaluated the agonistic and antagonistic activities of EGb761 using a uterotrophic assay in immature female rats. To evaluate agonistic and antagonistic effects of EGb761 on uterus, 21-day-old immature Sprague-Dawley (SD) female rats were treated with EGb761 (100, 200, or 400 mg/kg) by oral gavage, 10 μg/kg of estradiol (E2) or 1 mg/kg tamoxifen (TM) by subcutaneous injection, or with EGb761 plus E2 or TM for 3 consecutive days. At the end of the treatment period, animals were sacrificed and their body weights and organ weights (liver, lung, spleen and kidney) were measured. In addition, estrogen-related gene expressions (IGFBP-1 in liver and CaBP-9 in uterus) were determined. During the experiment, no animal showed clinical signs, a change in body weight or died. EGb761 treatment alone had no effect on absolute/relative uterine weight, luminal epithelial cell height (LECH, μm), or luminal circumference (LC, μm). In addition, uterine weights, LECHs, and LC induced by E2 or TM were not significantly changed by EGb761 at any dose. These results collectively suggested EGb761 has no agonistic/antagonistic effects in utero.

Phytoestrogenic effect of Inula racemosa Hook f – A cardioprotective root drug in traditional medicine

Ethnopharmacological relevanceRoots of Inula racemosa are used as a cardio protective in Ayurveda in India, being prescribed as a medicine for precordial chest pain, cough and dyspnoea, both singly and as a poly herbal. AimEvaluation of Phytoestrogenic activity of the root extracts of Inula racemosa and compounds isolated therefrom in vivo, in silico and in vitro. Materials and methodsAlcohol (IrA) and hexane (IrH) extracts characterized by HPTLC/GC-MS analysis respectively and processed for compound isolation were evaluated for estrogenic activity (100 & 250mg/kg bw) by the Immature rat uterotrophic assay using ethinylestradiol (EE −30µg/kg bw) as standard drug. Alantolactone (ALT), Isoalantolactone (IALT) and Stigmasterolglucoside (SG) isolated from the extracts were characterized and screened in silico for ERα, ERβ binding affinity, assessed in vitro for growth modulatory effects on MCF-7 cells by MTT assay and cell cycle distribution analysis using Flow cytometry. RT-PCR analysis evaluated the mRNA expression of pS2 in these cells post exposure to ALT, IALT and SG. ResultsIn the IrA treated groups there has been a statistically significant increase (P < 0.05) in absolute and normalised uterine weight, uterine diameter, endometrial thickness, luminal epithelial cell height,diameter of ovary and in the number of primary and secondary ovarian follicles relative to untreated controls. Presence of ciliated epithelial cells in the oviduct, elevated number of early growing follicles characterized by an increased oocyte diameter, and signs of vascularization in the cortex of ovarian sections in this group relative to EE treated group are indicative of pervasive activation of follicular growth and initiation. Virtual docking demonstrated ERα affinity for IALT, ERβ affinity for ALT, while SG showed a high binding affinity to both with a relatively greater ERβ binding affinity. Dose dependent decrease in cell viability mediated by IALT and SG in the MTT assay is corroborated by a statistically significant increase (p < 0.05) in sub G0-G1 cells by SG at 200 and 400µM in cell cycle analysis and there has been an induction of pS2 by IALT and SG in the ER regulated MCF-7 cells. ConclusionsDemonstration of classical morphological changes induced by estrogen stimulation mediated by IrA in vivo at both the tested doses, isolation of the antioxidant SG from IrA and its dose dependent growth inhibitory effect on estrogen sensitive MCF-7 cells through apoptotic induction and an up regulation of pS2 are suggestive of an anti-estrogenic effect through estrogen receptor binding affinity, typical of phytoestrogens that bind to ER but do not elicit a full estrogenic response. The observed estrogenic effect of IrA suggests a multi mechanistic molecular action involving antioxidant as well as redox signalling pathways acting in consonance with their anti-estrogenic effects owing to the weak estrogen like competitive receptor binding of SG.

Skeletal and Uterotrophic Effects of Endoxifen in Female Rats.

Endoxifen, the primary active metabolite of tamoxifen, is currently being investigated as a novel endocrine therapy for the treatment of breast cancer. Tamoxifen is a selective estrogen receptor modulator that elicits potent anti-breast cancer effects. However, long-term use of tamoxifen also induces bone loss in premenopausal women and is associated with an increased risk of endometrial cancer in postmenopausal women. For these reasons, we have used a rat model system to comprehensively characterize the impact of endoxifen on the skeleton and uterus. Our results demonstrate that endoxifen elicits beneficial effects on bone in ovary-intact rats and protects against bone loss following ovariectomy. Endoxifen is also shown to reduce bone turnover in both ovary-intact and ovariectomized rats at the cellular and biochemical levels. With regard to the uterus, endoxifen decreased uterine weight but maintained luminal epithelial cell height in ovariectomized animals. Within luminal epithelial cells, endoxifen resulted in differential effects on the expression levels of estrogen receptors α and β as well as multiple other genes previously implicated in regulating epithelial cell proliferation and hypertrophy. These studies analyze the impact of extended endoxifen exposure on both bone and uterus using a Food and Drug Administration-recommended animal model. Although endoxifen is a more potent breast cancer agent than tamoxifen, the results of the present study demonstrate that endoxifen does not induce bone loss in ovary-intact rats and that it elicits partial agonistic effects on the uterus and skeleton in ovariectomized animals.

Effects of a glyphosate-based herbicide on the uterus of adult ovariectomized rats.

Glyphosate is the active ingredient of several herbicide formulations. Different reports suggest that glyphosate-based herbicides (GBHs) may act as endocrine disruptors. We evaluated the potential estrogenic effects of a GBH formulation using the uterotrophic assay. Adult ovariectomized rats were sc injected for 3 consecutive days with: saline solution (vehicle control), 2.10-5 g E2 /kg/day (uterotrophic dose; UE2 ), 2.10-7 g E2 /kg/day (nonuterotrophic dose; NUE2 ), or 0.5, 5, or 50mg GBH/kg/day of the. Twenty-four hours after the last injection, the uterus was removed and weighed and processed for histopathology and mRNA extraction. Epithelial cell proliferation and height and expression of estrogen-responsive genes were evaluated (estrogen receptors, ERα and ERβ; progesterone receptor, PR; complement 3, C3). Uterine weight and epithelial proliferation were not affected by GBH. However, the luminal epithelial cell height increased at GBH0.5. ERα mRNA was downregulated by all GBH doses and E2 groups, whereas PR and C3 mRNA were diminished by GBH0.5. GBH5-, GBH50-, and UE2 -treated rats showed downregulated ERα protein expression in luminal epithelial cells, while the receptor was upregulated in the stroma. GBH upregulated ERβ (GBH0.5-50) and PR (GBH5) expressions in glandular epithelial cells, similar effect to that of NUE2 group. These results indicate that, although the uterine weight was not affected, GBH modulates the expression of estrogen-sensitive genes. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1191-1201, 2017.

Assessment of estrogenic potential of diethyl phthalate in female reproductive system involving both genomic and non-genomic actions.

Phthalates are the diverse group of compounds abundantly present in environment. The present study shows the estrogenic potential of diethyl phthalate (DEP). The data showed that DEP increased the transactivation of ER in CHO and MCF-7 cells suggesting its interaction with ER. In vivo parameters like increased uterine epithelial cell height and up regulation of various steroidogenic genes were also observed in adult female rats. Our uterotrophic assay data from immature female rats suggested that DEP treatment resulted in augmentation of uterine weight as well as luminal epithelial cell heights in both vaginal and uterine tissues. Further, DEP was able to upregulate pS2 gene expression with simultaneous activation of MAPK pathway as demonstrated by increased p-ERK/ERK ratio. Taken together, the present data suggests that DEP acts as an estrogenic compound and based on these data further detailed studies would reveal its mode of action at cellular levels.

Comparative uterotrophic effects of endoxifen and tamoxifen in ovariectomized Sprague-Dawley rats.

Endoxifen (4-hydroxy-N-desmethyl-tamoxifen), one of the major active metabolites of tamoxifen, has substantially greater estrogen antagonist properties and antiproliferative effects in breast tumor cells than tamoxifen, a mixed estrogen agonist/antagonist. An associated risk of endometrial cancer and hyperplasia has been linked to the estrogen agonist properties of tamoxifen. We evaluated endoxifen using a classic uterotrophic effects method. Rats were given endoxifen or tamoxifen orally for 3 days. Estradiol was the positive control. Endoxifen and tamoxifen plasma levels exceeded those previously observed clinically. Uterine weight was 3-fold higher in the estradiol group than in the tamoxifen or endoxifen groups, which did not differ from vehicle controls. Tamoxifen and endoxifen caused a greater increase in luminal epithelial cell height than estradiol. Both tamoxifen and endoxifen produced an increase in the stromal BrdU labeling index (LI) that was ≤ estradiol and inversely related to dose, but did not affect luminal epithelial cell BrdU LI. As expected, estradiol increased luminal epithelial cell proliferation. These results indicate that endoxifen induces uterotrophic effects, but is less potent than estradiol in eliciting these effects. Given prior preclinical observations that endoxifen has superior antitumor activity than tamoxifen, the observations of similar uterine effects suggest that the endoxifen risk/benefit ratio may be superior to tamoxifen.

Effects of tamoxifen and ethynylestradiol cotreatment on uterine gene expression in immature, ovariectomized mice

Tamoxifen (TAM), the primary treatment for estrogen receptor (ER)-positive breast cancer, has been associated with an increased incidence of endometrial cancer in postmenopausal, but not premenopausal women. TAM elicits a partial ER-mediated uterotrophic response in immature rodents when compared with ethynylestradiol (EE), a potent ER agonist. However, cotreatment with 1000 microg/kg TAM antagonizes the uterotrophic effect induced by 30 microg/kg EE. To further investigate the anti-uterotrophic activity of TAM, immature, ovariectomized C57BL/6 mice were treated with a single oral dose of EE, TAM, EE+TAM, or vehicle, and harvested at 2, 4, 8, 12, 18, and 24 h or after three daily treatments at 72 h. Significant increases in uterine wet weight (UWW) were observed at 18 h for EE, TAM, and the mixture. However, mixture induction of UWW was significantly lower when compared with EE-induced uterotrophy at 72 h. This inhibitory effect is also reflected in decreases in luminal circumference, yet EE-induced luminal epithelial cell height was unaffected by cotreatment with TAM. Gene expression analysis using a 2 x 2 factorial cDNA microarray study design identified 2518 differentially expressed genes following EE treatment alone. However, only 290 EE-elicited gene expression changes were affected by TAM cotreatment, in a manner consistent with the anti-estrogenic response. These data suggest that TAM antagonism of EE-induced UWW increase involves the selective inhibition of EE-induced genes.

Bisphenol-A exposure during the period of blastocyst implantation alters uterine morphology and perturbs measures of estrogen and progesterone receptor expression in mice

Bisphenol-A (BPA) has estrogenic properties both in vitro and in vivo. We investigated its impacts upon uterine morphology and estrogen and progesterone receptors after injection on gestational days 1–4 in doses known to disrupt pregnancy. Blastocyst implantation was significantly reduced by doses of 6.75 and 10.125 mg/animal. Uterine luminal area expanded substantially in response to increasing doses of BPA. Luminal epithelial cell height increased following exposure to 10.125 mg/animal, whereas there were no differences in the number of corpora lutea among conditions. The proportion of cells staining positively for estrogen receptors was affected non-monotonically, showing highest levels at 3.375 mg/animal and lowest levels at 10.125 mg/animal. Similarly progesterone receptor expression measured through western blots related non-monotonically to dose, being highest at 3.375 mg/animal and diminishing with increasing dose. These results suggest that BPA exposure during early gestation acts at the uterus to disrupt intrauterine implantation, consistent with an estrogenic effect.

In vivo estrogenic potential of 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene, an active metabolite of bisphenol A, in uterus of ovariectomized rat

4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), an active metabolite of bisphenol A (BPA), has more potent estrogenic activity than BPA in vitro, but its activity in vivo is not established. Here, we examined in vivo estrogenic activity of MBP by means of uterotrophic assay in ovariectomized (OVX) female rats. MBP exhibited dose-dependent estrogenic activity, as evaluated in terms of effects on uterus weight, uterine luminal epithelial cell height and myometrium thickness. The highest concentration of MBP (10 mg/kg/day) completely reversed the changes caused by OVX, and its activity was equivalent to that of 5 μg/kg/day 17β-estradiol (E2). We also investigated the effects of MBP on transcription of several estrogen-related genes. The changes of mRNA levels of estrogen receptors α and β, c-fos and insulin-like growth factor 1 in MBP-treated OVX rats were qualitatively similar to those in E2-treated rats. BPA did not show any significant effect on OVX rat in these conditions. This study is the first to demonstrate that MBP, an active metabolite of BPA, has potent in vivo estrogenic activity, being about 500-fold more potent than BPA in OVX rats.

Effects of metformin on mammalian target of rapamycin in a mouse model of endometrial hyperplasia

Objective The effects of metformin on S6K1, which is a crucial effector of mTOR signaling, and on endometrium were studied in a mouse model of endometrial hyperplasia induced by unopposed estradiol or tamoxifen. Study design Forty-eight oophorectomized Balb/c mice were randomly assigned to receive saline, tamoxifen citrate (4 mg/kg), 17-beta estradiol hemihydrate (4 mg/kg), metformin (50 mg/kg), tamoxifen citrate (4 mg/kg) with metformin (50 mg/kg), or estradiol (4 mg/kg) with metformin (50 mg/kg) for 3 days. Histological markers of uterotrophy, including luminal epithelial cell height and density of endometrial glands were quantified for each slide. Immunohistochemical expression of PCNA and S6K1 was evaluated. H-score was used for S6K1 expression. Statistical analysis was performed using Student's t-test for comparison of two continous variables and one-way ANOVA for comparison of multiple variables. Results Mice treated either with tamoxifen or estradiol had significantly increased density of endometrial glands and epithelial heights compared to vehicle-only or metformin-only group ( p < 0.001). Addition of metformin to tamoxifen or estradiol treated mice significantly decreased the density of endometrial glands and epithelial cell heights ( p < 0.05). Addition of metformin to tamoxifen significantly decreased the H-score of S6K1 ( p < 0.05) and the immunohistochemical expression of PCNA ( p < 0.05) in uterine lining epithelium, glandular and stromal cells. Addition of metformin to estradiol significantly decreased the H-score of S6K1 ( p < 0.05) and the immunohistochemical expression of PCNA ( p < 0.05) in uterine lining epithelium, glandular and stromal cells. Conclusion Metformin seems to have possible antiproliferative effects on the endometrium of estradiol or tamoxifen treated mice via inhibiting the mTOR mediated S6K1 activation.

Endosulfan modulates estrogen-dependent genes like a non-uterotrophic dose of 17β-estradiol

The estrogenic activity of environmentally relevant doses of endosulfan was investigated using an animal model. Ovariectomized adult rats were injected once a day for 3 days with sesame oil (control), 0.02 mg/kg/day 17β-estradiol (an uterotrophic dose; UE 2), 0.0002 mg/kg/day 17β-estradiol (a non-uterotrophic dose; NUE 2), or 0.006, 0.06, 0.6 or 6 mg/kg/day endosulfan. After 24 h of treatment, the uteri were weighed (uterotrophic assay) and the luminal epithelial cell height (LECH) and progesterone receptor (PR), and estrogen receptor alpha (ERα) protein levels were measured. PR, ERα, and complement factor-3 (C3) mRNAs were evaluated using real-time PCR. Uterine weight and LECH were only increased in UE 2-treated rats. PR, ERα and C3 expression levels were modified in most of the endosulfan-treated groups, showing an identical pattern of expression to the NUE 2-group. Our results show that the pesticide endosulfan mimics non-uterotrophic E 2 actions, strengthening the hypothesis that endosulfan is a widespread xenoestrogen.

Estrogen‐induced uterine abnormalities in TIMP‐1 deficient mice are associated with elevated plasmin activity and reduced expression of the novel uterine plasmin protease inhibitor serpinb7

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is a multifunctional protein capable of regulating a variety of biological processes in a wide array of tissue and cell types. We have previously demonstrated that TIMP-1 deficient mice exhibit alterations in normal uterine morphology and physiology. Most notably, absence of TIMP-1 is associated with an altered uterine phenotype characterized by profound branching of the uterine lumen and altered adenogenesis. To begin to assess the mechanism by which TIMP-1 may control these uterine events, we utilized steroid-treated ovariectomized wild-type and TIMP-1 null mice exposed to estrogen for 72 hr. Administration of estrogen to TIMP-1 deficient mice resulted in development of an abnormal uterine histo-architecture characterized by increased endometrial gland density, luminal epithelial cell height, and abnormal lumen structure. To determine the mediators which may contribute to the abnormal uterine morphology in the TIMP-1 deficient mice, cDNA microarray analysis was performed. Analysis revealed that expression of two plasmin inhibitors (serpbinb2 and serbinb7) was significantly reduced in the TIMP-1 null mice. Associated with the reduction in expression of these inhibitors was a significant increase in plasmin activity. Localization of the novel uterine serpinb7 revealed that expression was confined to the luminal and glandular epithelial cells. Further, expression of uterine serpinb7 was decreased by estrogen and showed an inverse relationship with plasmin activity. We conclude from these studies that in addition to controlling MMP activity, TIMP-1 may also control activity of serine proteases through modulation of serine protease inhibitors such as serpinb7.

Drinking Water with Uranium below the U.S. EPA Water Standard Causes Estrogen Receptor–Dependent Responses in Female Mice

BackgroundThe deleterious impact of uranium on human health has been linked to its radioactive and heavy metal–chemical properties. Decades of research has defined the causal relationship between uranium mining/milling and onset of kidney and respiratory diseases 25 years later.ObjectiveWe investigated the hypothesis that uranium, similar to other heavy metals such as cadmium, acts like estrogen.MethodsIn several experiments, we exposed intact, ovariectomized, or pregnant mice to depleted uranium in drinking water [ranging from 0.5 μg/L (0.001 μM) to 28 mg/L (120 μM).ResultsMice that drank uranium-containing water exhibited estrogenic responses including selective reduction of primary follicles, increased uterine weight, greater uterine luminal epithelial cell height, accelerated vaginal opening, and persistent presence of cornified vaginal cells. Coincident treatment with the antiestrogen ICI 182,780 blocked these responses to uranium or the synthetic estrogen diethylstilbestrol. In addition, mouse dams that drank uranium-containing water delivered grossly normal pups, but they had significantly fewer primordial follicles than pups whose dams drank control tap water.ConclusionsBecause of the decades of uranium mining/milling in the Colorado plateau in the Four Corners region of the American Southwest, the uranium concentration and the route of exposure used in these studies are environmentally relevant. Our data support the conclusion that uranium is an endocrine-disrupting chemical and populations exposed to environmental uranium should be followed for increased risk of fertility problems and reproductive cancers.

Comparative uterine response of the selective estrogen receptor modulators (SERMs) Bazedoxifene (BZA), raloxifene (RLX) AND lasofoxifene (LFX) in rodent models

Comparative uterine response of the selective estrogen receptor modulators (SERMs) Bazedoxifene (BZA), raloxifene (RLX) AND lasofoxifene (LFX) in rodent models

Comparative temporal and dose-dependent morphological and transcriptional uterine effects elicited by tamoxifen and ethynylestradiol in immature, ovariectomized mice

BackgroundUterine temporal and dose-dependent histopathologic, morphometric and gene expression responses to the selective estrogen receptor modulator tamoxifen (TAM) were comprehensively examined to further elucidate its estrogen receptor-mediated effects. These results were systematically compared to the effects elicited by the potent estrogen receptor ligand 17α-ethynylestradiol (EE) to identify pathways similarly and uniquely modified by each compound.ResultsThree daily doses of 100 μg/kg TAM elicited a dose-dependent increase in uterine wet weight (UWW) in immature, ovariectomized C57BL/6 mice at 72 hrs with concurrent increases in luminal epithelial cell height (LECH), luminal circumference and glandular epithelial tubule number. Significant UWW and LECH increases were detected at 24 hrs after a single dose of 100 μg/kg TAM. cDNA microarray analysis identified 2235 differentially expressed genes following a single dose of 100 μg/kg TAM at 2, 4, 8, 12, 18 and 24 hrs, and at 72 hrs after three daily doses (3 × 24 hrs). Functional annotation of differentially expressed genes was associated with cell growth and proliferation, cytoskeletal organization, extracellular matrix modification, nucleotide synthesis, DNA replication, protein synthesis and turnover, lipid metabolism, glycolysis and immunological responses as is expected from the uterotrophic response. Comparative analysis of TAM and EE treatments identified 1209 common, differentially expressed genes, the majority of which exhibited similar profiles despite a temporal delay in TAM elicited responses. However, several conserved and treatment specific responses were identified that are consistent with proliferation (Fos, Cdkn1a, Anapc1), and water imbibition (Slc30a3, Slc30a5) responses elicited by EE.ConclusionOverall, TAM and EE share similar gene expression profiles. However, TAM responses exhibit lower efficacy, while responses unique to EE are consistent with the physiological differences elicited between compounds.