scholarly journals Glyphosate-based herbicide enhances the uterine sensitivity to estradiol in rats

2018 ◽  
Vol 239 (2) ◽  
pp. 197-213 ◽  
Author(s):  
Marlise Guerrero Schimpf ◽  
María M Milesi ◽  
Enrique H Luque ◽  
Jorgelina Varayoud
Keyword(s):  
Cell Proliferation ◽  
Endometrial Hyperplasia ◽  
Low Dose ◽  
Saline Solution ◽  
Female Rats ◽  
Postnatal Exposure ◽  
Rat Uterus ◽  
Mrna Extraction ◽  
17Β Estradiol ◽  
Prepubertal Rats

In a previous work, we detected that postnatal exposure to a glyphosate-based herbicide (GBH) alters uterine development in prepubertal rats causing endometrial hyperplasia and increasing cell proliferation. Our goal was to determine whether exposure to low dose of a GBH during postnatal development might enhance the sensitivity of the uterus to an estrogenic treatment. Female Wistar pups were subcutaneously injected with saline solution (control) or GBH using the reference dose (2 mg/kg/day, EPA) on postnatal days (PND) 1, 3, 5 and 7. At weaning (PND21), female rats were bilaterally ovariectomized and treated with silastic capsules containing 17β-estradiol (E2, 1 mg/mL) until they were 2 months of age. On PND60, uterine samples were removed and processed for histology, immunohistochemistry and mRNA extraction to evaluate: (i) uterine morphology, (ii) uterine cell proliferation by the detection of Ki67, (iii) the expression of the estrogen receptors alpha (ESR1) and beta (ESR2) and (iv) the expression of WNT7A and CTNNB1. GBH-exposed animals showed increased luminal epithelial height and stromal nuclei density. The luminal and glandular epithelium were markedly hyperplastic in 43% of GBH-exposed animals. GBH exposure caused an increase in E2-induced cell proliferation in association with an induction of both ESR1 and ESR2. GBH treatment decreased membranous and cytoplasmic expression of CTNNB1 in luminal and glandular epithelial cells and increased WNT7A expression in the luminal epithelium. These results suggest that early postnatal exposure to a GBH enhances the sensitivity of the rat uterus to estradiol and induces histomorphological and molecular changes associated with uterine hyperplasia.

scholarly journals The estrogen receptor α Σ3 mRNA splicing variant is differentially regulated by estrogen and progesterone in the rat uterus

2005 ◽  
Vol 186 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J Varayoud ◽  
J G Ramos ◽  
L Monje ◽  
V Bosquiazzo ◽  
M Muñoz-de-Toro ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Alternative Splicing ◽  
Estrous Cycle ◽  
Low Dose ◽  
Estrogen Receptor Α ◽  
Mrna Splicing ◽  
Female Rats ◽  
Rt Pcr ◽  
Mrna Isoforms ◽  
Rat Uterus

The gene for estrogen receptor α (ERα) has been shown to be under complex hormonal control and its activity can be regulated by mRNA alternative splicing. Here we examined the regulation of ERα transcription and translation in the rat uterus by ovarian steroid hormones. We examined whether expression of ERα mRNA splice isoforms is hormonally regulated in ovariectomized (OVX) and cycling rats. Adult OVX female rats were treated daily with 17-β estradiol (E2) (0.05 μg/rat or 5 μg/rat), progesterone (P4) (1 mg/rat) or a combination of both hormones for 4 days. Animals were killed 24 h after the last injection and uterine horns were removed. In order to determine whether ERα mRNA isoforms are differentially expressed under various physiological conditions, animals were evaluated at proestrus, estrus and diestrus. The ERα protein and mRNA were detected by immunohistochemistry and comparative RT-PCR analysis respectively. The presence of ERα mRNA isoforms was evaluated using a nested RT-PCR assay. In OVX control rats, ERα mRNA and protein levels were high, demonstrating a constitutive expression of the ERα gene in the uterus. When animals received P4 or the high dose of E2, a significant decrease in both ERα mRNA and protein was observed in the uterus. However, when rats were protein was treated with the low dose of E2, only the ERα down-regulated; no changes were observed in ERα mRNA expression. In addition to the full-length ERα mRNA, OVX control rat uteri expressed three shorter transcripts: Σ3, Σ4 and Σ3,4 (lacking exon 3, exon 4, or both 3 and 4 respectively). Surprisingly, when OVX animals were treated with P4, the low dose of E2 or a combination of both steroids, expression of the Σ3 isoform was completely abolished. During the estrous cycle, all ERα mRNA splicing variants were detected at proestrus and estrus. However, in diestrus, significant low levels of the Σ3 isoform were observed. In summary, our results suggest a dose-dependent relationship between E2 concentrations and the level of control in the ERα transcription–translation cascade. Moreover, the alternative splicing of the ERα primary transcript is influenced by the hormonal milieu, suggesting that these events could affect the estrogen responsiveness of the rat uterus during the estrous cycle.

scholarly journals Sexual dimorphism and thyroid dysfunction: a matter of oxidative stress?

2014 ◽  
Vol 221 (2) ◽  
pp. R31-R40 ◽  
Author(s):  
Rodrigo S Fortunato ◽  
Andrea C F Ferreira ◽  
Fabio Hecht ◽  
Corinne Dupuy ◽  
Denise P Carvalho
Keyword(s):  
Oxidative Stress ◽  
Cell Proliferation ◽  
Sexual Dimorphism ◽  
Thyroid Dysfunction ◽  
Antioxidant Defense ◽  
Redox Balance ◽  
Female Rats ◽  
Male Rats ◽  
17Β Estradiol ◽  
Thyroid Dysfunctions

Thyroid diseases, such as autoimmune disease and benign and malignant nodules, are more prevalent in women than in men, but the mechanisms involved in this sex difference is still poorly defined. H2O2is produced at high levels in the thyroid gland and regulates parameters such as cell proliferation, migration, survival, and death; an imbalance in the cellular oxidant–antioxidant system in the thyroid may contribute to the greater incidence of thyroid disease among women. Recently, we demonstrated the existence of a sexual dimorphism in the thyrocyte redox balance, characterized by higher H2O2production, due to higher NOX4 and Poldip2 expression, and weakened enzymatic antioxidant defense in the thyroid of adult female rats compared with male rats. In addition, 17β-estradiol administration increasedNOX4mRNA expression and H2O2production in thyroid PCCL3 cells. In this review, we discuss the possible involvement of oxidative stress in estrogen-related thyroid pathophysiology. Our current hypothesis suggests that a redox imbalance elicited by estrogen could be involved in the sex differences found in the prevalence of thyroid dysfunctions.

Gene expression analysis of metabolic markers during bone regeneration in a rat model

2014 ◽  
Vol 23 (03) ◽  
pp. 207-211
Author(s):  
C. Kasch ◽  
A. Osterberg ◽  
Thordis Granitzka ◽  
T. Lindner ◽  
M. Haenle ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Expression Analysis ◽  
Saline Solution ◽  
Female Rats ◽  
Synthesis Rate ◽  
Metabolic Markers ◽  
Expression Levels ◽  
Fibrotic Tissue ◽  
Intermittent Pth ◽  
Lower Expression

SummaryThe RANK/RANKL/OPG system plays an important role in the regulation of bone metabolism and bony integration around implants. The aim of this study was to analyse gene expression of OPG, RANK, and RANKL in regenerating bone during implant integration. Additionally, the effect of intermittent para - thyroid hormone (PTH) treatment was analysed. A titanium chamber was implanted in the proximal tibiae of 48 female rats. The animals received either human PTH or saline solution (NaCl). After 21 and 42 days, RNA was isolated from tissue adjacent to the implant and expression of RANK, RANKL, and OPG was analysed. After 21 days, very low expression levels of all genes were shown. In contrast, increased gene expression after 42 days was determined. Expression of RANK and RANKL was lower than that for OPG. The lower expression levels after 21 days might be due to still ossifying, fibrotic tissue around the titanium chamber. An increased OPG synthesis rate associated with decreased RANKL expression after 42 days revealed bone-forming processes. Despite significant differences in gene expression between the time points, only slight differences were observed between application of intermittent PTH and NaCl after a period of 42 days.

scholarly journals A New Anti-Estrogen Discovery Platform Identifies FDA-Approved Imidazole Anti-Fungal Drugs as Bioactive Compounds against ERα Expressing Breast Cancer Cells

2021 ◽  
Vol 22 (6) ◽  
pp. 2915
Author(s):  
Manuela Cipolletti ◽  
Stefania Bartoloni ◽  
Claudia Busonero ◽  
Martina Parente ◽  
Stefano Leone ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Bioactive Compounds ◽  
Estrogenic Activity ◽  
Estrogen Receptor Α ◽  
Breast Cancers ◽  
Cellular Models ◽  
Cancer Models ◽  
17Β Estradiol ◽  
Approved Drugs ◽  
Anti Fungal

17β-estradiol (E2) exerts its physiological effects through the estrogen receptor α (i.e., ERα). The E2:ERα signaling allows the regulation of cell proliferation. Indeed, E2 sustains the progression of ERα positive (ERα+) breast cancers (BCs). The presence of ERα at the BC diagnosis drives their therapeutic treatment with the endocrine therapy (ET), which restrains BC progression. Nonetheless, many patients develop metastatic BCs (MBC) for which a treatment is not available. Consequently, the actual challenge is to complement the drugs available to fight ERα+ primary and MBC. Here we exploited a novel anti-estrogen discovery platform to identify new Food and Drug Administration (FDA)-approved drugs inhibiting E2:ERα signaling to cell proliferation in cellular models of primary and MBC cells. We report that the anti-fungal drugs clotrimazole (Clo) and fenticonazole (Fenti) induce ERα degradation and prevent ERα transcriptional signaling and proliferation in cells modeling primary and metastatic BC. The anti-proliferative effects of Clo and Fenti occur also in 3D cancer models (i.e., tumor spheroids) and in a synergic manner with the CDK4/CDK6 inhibitors palbociclib and abemaciclib. Therefore, Clo and Fenti behave as “anti-estrogens”-like drugs. Remarkably, the present “anti-estrogen” discovery platform represents a valuable method to rapidly identify bioactive compounds with anti-estrogenic activity.

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