Increased Estrogen Receptor Research Articles

Genistein activated adenosine 5′-monophosphate-activated protein kinase–sirtuin1/peroxisome proliferator-activated receptor γ coactivator-1α pathway potentially through adiponectin and estrogen receptor β signaling to suppress fat deposition in broiler chickens

Genistein can be used as a dietary additive to control fat deposition in animals, while its mechanism is poorly understood. In this study, a total of 144 male broilers were randomly divided into 4 groups. Birds were fed standard diets supplemented with 0, 50, 100 or 150 mg of genistein/kg from 21 to 42 d of age. Results showed that genistein treatment decreased the relative weight of abdominal fat and triglyceride contents in broiler chickens. Genistein downregulated hepatic lipid droplets accumulation and upregulated the activity of lipoprotein lipase and hepatic lipase and the concentration of adiponectin. Furthermore, the liver X receptor α, sterol regulatory element–binding protein 1c (SREBP-1c), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) mRNA expressions were decreased, whereas adiponectin receptor 2, peroxisome proliferator-activated receptor α, adipose triglyceride lipase, and carnitine palmitoyl transferase-I (CPT-I) mRNA abundances were increased in the liver of broilers treated with genistein. In addition, genistein increased the NAD+ concentration and NAD+/NADH ratio in the liver. Genistein increased estrogen receptor β (ERβ), forkhead box O1, nicotinamide phosphoribosyl transferase, sirtuin1 (SIRT1), phospho (p)-adenosine 5′-monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), p-ACC, and CPT-I protein levels, whereas the SREBP-1c and FAS levels were decreased. These data indicated that genistein might reduce fat accumulation in broiler chickens via activating the AMPK-SIRT1/PGC-1α signaling pathway. The activation of this signaling pathway might be achieved by its direct effect on improving the adiponectin secretion or its indirect effect on upregulation of ERβ expression level through paracrine acting of adiponectin.

Tussilagone promotes osteoclast apoptosis and prevents estrogen deficiency-induced osteoporosis in mice

Osteoporosis is a degenerative disease characterized by reduced bone mass, in which deregulated bone remodeling by osteoclasts and osteoblasts is a main pathogenesis. Although recently tussilagone, a major active component of flower buds of Tussilago farfara, has been shown to inhibit osteoclastogenesis, its effect on estrogen deficiency-induced osteoporosis remains unknown. This study examined the effect of tussilagone on bone loss in ovariectomized mice and further explored its impact on osteoclast apoptosis and osteoblast formation in addition to osteoclastogenesis. Tussilagone suppression of osteoclastogenesis was confirmed in bone marrow derived macrophages, which was observed with the 1/10 concentration of that of the previous study. As demonstrated by ApoPercentage dye staining and Western blotting, tussilagone enhanced apoptosis in differentiated osteoclasts by increasing estrogen receptor α and Fas ligand expression. On the contrary, either osteoblast differentiation or mineralization was not affected by tussilagone. Lastly, administering tussilagone to mice for 6 weeks prevented trabecular microarchitecture impairment in ovariectomized mice compared to vehicle control groups. These findings suggest that tussilagone or Tussilago farfara prevents osteoporotic bone loss by suppressing osteoclast differentiation and inducing osteoclast apoptosis, and that it may therefore offer a possible remedy against resorptive bone diseases.

Disruption of classical estrogenic targets in brown trout primary hepatocytes by the model androgens testosterone and dihydrotestosterone

Estrogenic effects triggered by androgens have been previously shown in a few studies. Aromatization and direct binding to estrogen receptors (ERs) are the most proposed mechanisms. For example, previously, a modulation of vitellogenin A (VtgA) by testosterone (T), an aromatizable androgen, was reported in brown trout primary hepatocytes. The effect was reversed by an ER antagonist. In this study, using the same model the disruption caused by T and by the non-aromatizable androgen - dihydrotestosterone (DHT), was assessed in selected estrogenic targets. Hepatocytes were exposed (96 h) to six concentrations of each androgen. The estrogenic targets were VtgA, ERα, ERβ1 and two zona pellucida genes, ZP2.5 and ZP3a.2. The aromatase CYP19a1 gene and the androgen receptor (AR) were also included. Modulation of estrogenic targets was studied by quantitative real-time PCR and immunohistochemistry, using an HScore system. VtgA and ERα were up-regulated by DHT (1, 10, 100 μM) and T (10, 100 μM). In contrast, ERβ1 was down-regulated by DHT (10, 100 μM), and T (100 μM). ZP2.5 mRNA levels were increased by DHT and T (1, 10, 100 μM), while ZP3a.2 was up-regulated by DHT (100 μM) and T (10, 100 μM). Positive correlations were found between VtgA and ERα mRNA levels and ZPs and ERα, after exposure to both androgens. The mRNA levels of CYP19a1 were not changed, while AR expression tended to increase after micromolar DHT exposures. HScores for Vtg and ZPs corroborated the molecular findings. Both androgens triggered estrogen signaling through direct binding to ERs, most probably ERα.

Maternal high-fat diet up-regulates type-1 cannabinoid receptor with estrogen signaling changes in a sex- and depot- specific manner in white adipose tissue of adult rat offspring.

Obesity and high-fat (HF) diet are associated with over activation of the endocannabinoid system (ECS). We have demonstrated that maternal HF diet induces early obesity and modulates cannabinoid signaling in visceral (VIS) and subcutaneous (SUB) white adipose tissue (WAT) in weanling rat offspring. We hypothesized that perinatal maternal HF diet would program the expression of ECS in adipose tissue in a long-term way in parallel to alterations in epigenetic markers and sex hormone signaling. Progenitor female rats received control diet (C, 9% fat) or isocaloric high-fat diet (HF, 28% fat) for 8weeks before mating, gestation, and lactation. All pups were weaned to C diet and they were euthanized at 180days old. Maternal HF diet induced overweight and increased SUB WAT mass of male and female adult offspring. Maternal HF diet induced hypertrophy of VIS and SUB adipocytes only in female offspring associated with increased type 1 cannabinoid receptor protein (CB1) and mRNA (Cnr1) levels. These changes were associated with increased estrogen receptor α binding to Cnr1 promoter in SUB WAT of adult female offspring, which may contribute to higher expression of Cnr1. Increased CB1 signaling in adipose tissue might contribute to higher adiposity programmed by maternal HF diet because endocannabinoids stimulate the accumulation of fat in the adipose tissue. Our findings provide molecular insights into sex-specific targets for anti-obesity therapies based on the endocannabinoid system.

Genetic analysis of a Taiwanese family identifies a DMRT3-OAS3 interaction that is involved in human sexual differentiation through the regulation of ESR1 expression

To identify the genetic etiology of recurrent disorders of sex development (DSDs) in a Taiwanese family with 46,XY sex reversal and hypospadias. Genetic and functional studies. Academic hospital. A three-generation family consisting of 22 members, with eight cases of 46,XY DSD, of whom four have 46,XY male-to-female sex reversal and four are 46,XY males with hypospadias. None. Results of exome sequencing and invitro protein and RNA analyses. All patients with DSDs were found to carry heterozygous missense mutations in the doublesex and mab-3-related transcription factor 3 (DMRT3; rs187176004, c.A815C, p.K272T) and 2',5'-oligoadenylate synthetase 3 (OAS3; rs16942374, c.G2606A, p.R869H) genes. The DMRT3 mutation increased estrogen receptor 1 (ESR1) expression. Upon binding with the OAS3-RNase L complex, wild-type DMRT3 promoted degradation of ESR1 mRNA. However, the DMRT3A815C-OAS3G2606A complex interacted less strongly with ESR1 mRNA and RNase L, ultimately preventing ESR1 mRNA degradation. The interactions between DMRT3, OAS3, and RNase L were confirmed in the patients' testis. Our results indicate that DMRT3 and OAS3 are involved in human DSDs by controlling ESR1 expression.

Divergent Regulation of Myotube Formation and Gene Expression by E2 and EPA during In-Vitro Differentiation of C2C12 Myoblasts.

Estrogen (E2) and polyunsaturated fatty acids (n-3PUFA) supplements independently support general wellbeing and enhance muscle regeneration in-vivo and myotube formation in-vitro. However, the combined effect of E2 and n-3PUFA on myoblast differentiation is not known. The purpose of the study was to identify whether E2 and n-3PUFA possess a synergistic effect on in-vitro myogenesis. Mouse C2C12 myoblasts, a reliable model to reiterate myogenic events in-vitro, were treated with 10nM E2 and 50μM eicosapentaenoic acid (EPA) independently or combined, for 0–24 h or 0–120 h during differentiation. Immunofluorescence, targeted qPCR and next generation sequencing (NGS) were used to characterize morphological changes and differential expression of key genes involved in the regulation of myogenesis and muscle function pathways. E2 increased estrogen receptor α (Erα) and the expression of the mitogen-activated protein kinase 11 (Mapk11) within 1 h of treatment and improved myoblast differentiation and myotube formation. A significant reduction (p < 0.001) in myotube formation and in the expression of myogenic regulatory factors Mrfs (MyoD, Myog and Myh1) and the myoblast fusion related gene, Tmem8c, was observed in the presence of EPA and the combined E2/EPA treatment. Additionally, EPA treatment at 48 h of differentiation inhibited the majority of genes associated with the myogenic and striated muscle contraction pathways. In conclusion, EPA and E2 had no synergistic effect on myotube formation in-vitro. Independently, EPA inhibited myoblast differentiation and overrides the stimulatory effect of E2 when used in combination with E2.

Epigenetic changes associated with increased estrogen receptor alpha mRNA transcript abundance during reproductive maturation in chicken ovaries

Estrogen receptor alpha (ERα) is a ligand-activated transcription factor that regulates cellular responses to estrogens and transcription processes of target genes. In this study, changes in DNA methylation and histone modifications in the promoter region and Exon 1 of the ERα gene were analyzed to ascertain epigenetic changes associated with increased ERα mRNA abundance during reproductive maturation from 90 (egg production not yet initiated) to 160 (after egg production was initiated) d of age (d post-hatching) in chicken ovaries. The results indicate there was no difference in CpG methylation at the promoter and Exon 1 except at the region analyzed with primer pairs F2 and R2, where percentage of methylated CpG of Sites 2 and 8 after reproductive maturation was greater compared with before reproductive maturation. By using the chromatin immunuoprecipitation (ChIP) assay combined with SYBR green quantitative PCR, effects of histone modifications were evaluated, including histone H3K4 di + tri methylation, H3K9 phosphorylation and trimethylation, H3K36 methylation and H3K27 acetylation on chicken ERα mRNA transcript abundance. The results indicated that there was a greater histone H3K27 acetylation and lesser H3K36 trimethylation associated with increased abundance of ERα mRNA transcript in chicken ovaries after reproductive maturation (90 compared with 160 d of age). In consistent with this finding, the relative abundance of transcriptional coactivator p300 mRNA transcript and protein in the ovaries was markedly greater in reproductively mature than immature chickens. Findings provide insights into the epigenetic regulations of the chicken ERα gene expression that is required for chicken ovarian development.

Immunohistochemical Biomarkers in Ductal Carcinoma &amp;lt;i&amp;gt;In Situ&amp;lt;/i&amp;gt;

Introduction: Breast ductal carcinoma In Situ (DCIS) can be defined as a malignant epithelial proliferation with growth limited by the basal membrane of the ductal epithelium, with no evidence of stromal invasion. There has been a trend of trying to subcategorize DCIS based on cell proliferation assays (Ki67) and the expression of hormone receptors and the human epidermal growth receptor (HER-2) as detected by immunohistochemistry, similar to invasive breast carcinomas (IBC). The aims were to evaluate the expression of breast cancer marker proteins in DCIS by immunohistochemistry to better categorize it. Methods: 46 biopsies from women with DCIS and IBC Luminal A-like were evaluated by immunohistochemistry staining of proteins already known to be biomarkers in IBC. For controls, normal breast tissue from mammoplasty (n = 3) was used. Results: Our results showed an increase of estrogen receptor (ER) and progesterone receptor (PR) expression relative to that in normal tissue samples (p

The steroid receptor coactivator 1 (SRC1) and 3 (SRC3) recruitment as a novel molecular initiating event of 4-n-nonylphenol in estrogen receptor α-mediated pathways.

Recently, the action of steroid receptor coactivators (SRCs) has been recognized to be an important molecular initiating event (MIE) in estrogenic adverse outcome pathways (AOPs). However, the role of SRCs in the molecular mechanisms of many highly concerned environmental estrogens remains poorly understood. In this study, the widely studied environmental estrogen, 4-n-nonylphenol (4-n-NP), was used as a typical pollutant to study SRCs recruitment in its estrogenic effects. In MCF7 cell proliferation (E-SCREEN) assay and MVLN cell assay, 4-n-NP showed significant estrogenic potency that involved an increase in estrogen receptor α (ERα), SRC1 and SRC3 transcript levels. Moreover, 4-n-NP was found to induce estrogen response element (ERE)-mediated activity via ERα in MVLN cells. To investigate the mechanism by which SRCs recruitment is induced by 4-n-NP-ERα, a coactivators recruitment assay was performed, and the results showed that 4-n-NP-ERα recruited both SRC1 and SRC3, whereas it failed to recruit SRC2. Similarly, it had no interaction with SRC2 in the ERα-SRC2 two-hybrid yeast assay. This is the first report to investigate the novel MIE of SRCs recruitment in 4-n-NP-ERα-induced estrogenicity. Overall, our results suggest that the action of 4-n-NP on estrogenic effects involves the following MIEs: the activation of ERα, the recruitment of SRC1 and SRC3, and the induction of ERE-mediated activity. The findings also provide valuable insights into the MIE associated with the different SRCs that are recruited in the adverse outcome pathways of environmental estrogens.

The effect of pregnancy on nitrogen retention, maternal insulin sensitivity, and mRNA abundance of genes involved in energy and amino acid metabolism in gilts.

Twenty-one of each pregnant (P) and nonserviced, nonpregnant (NP) sister-pairs of gilts were selected to investigate the effect of pregnancy on protein deposition (Pd; whole body and maternal), insulin sensitivity, and mRNA abundance of genes involved in energy and AA metabolism. Between breeding (study day 0) and day 111, P and NP gilts received 2.16 kg of the experimental diet (3.34 Mcal ME/kg, 17.6% crude protein, 0.78% standardized ileal digestible lysine) that was formulated to meet the estimated ME requirements of pregnant gilts (and meet or exceed AA requirements). Nitrogen balances were conducted on day 63 and 102 ± 0.2 of the study during 4-d periods. Blood samples were collected on day 43, 56, 71, 85, 98, and 108 ± 0.3 of the study to determine plasma concentrations of fasted IGF-1, estradiol (E2), and estrone sulfate (E1S). Frequently sampled intravenous glucose tolerance tests (FSIGTT) were conducted on day 75 ± 0.7 in 6 P and 5 NP gilts and on day 107 ± 0.4 in 17 P and 17 NP gilts and the MINMOD approach was applied to evaluate whole body insulin sensitivity and pancreatic responsiveness. Longissimus muscle (LM) and s.c. adipose tissue (AD) samples were excised from 12 P and 12 NP gilts at day 111 ± 0.4 of the study after euthanasia to determine mRNA abundance of key genes. Whole body Pd was greater (P < 0.001) at day 102 and maternal Pd was lower (P < 0.002) at day 63 and 102 for P compared to NP gilts. Plasma concentrations of E1S and E2 increased (P < 0.05) with study day for P gilts and remained constant for NP gilts, which coincided with reduced plasma concentrations of IGF-1 and increased estrogen receptor alpha (ESR1) mRNA abundance in LM of P gilts. Glucose effectiveness was not different between P and NP gilts, but whole body insulin sensitivity was lower (P = 0.004) in P compared to NP gilts on day 75 and 107, which corresponded with reduced mRNA abundances of SLC2A4, HK2, SREBF1, and FASN, and increased abundances of PDK4 and PPARGC1A in LM and AD. When fed identically, P gilts had greater whole body Pd at day 102, which reflects Pd in the pregnancy-associated tissues (at the expense of maternal Pd), likely driven by estrogen-stimulated insulin resistance in peripheral tissue and subsequent modulation of gene expression relating to glucose metabolism.

Tamoxifen Inhibits the Progression of Trauma-Induced Heterotopic Ossification in Mice.

BackgroundHeterotopic ossification (HO) is a kind of abnormal mineralized bone which usually occurs in muscle, tendon, or ligament. There are currently no effective drugs for the treatment and prevention of HO. Developing effective drugs that can inhibit HO is of profound significance and would provide new strategies for clinical treatment of this disease. The present investigation evaluated the inhibitory effect of tamoxifen against HO.Material/MethodsUsing an Achilles tendon trauma-induced HO female mice model, we screened different doses of tamoxifen (1, 3, and 9 mg/kg) in mice to determine the optimal dosage on the inhibition of the HO formation. The curative effect of tamoxifen was also illustrated at different HO progression stages including inflammation, chondrogenesis, osteogenesis, and HO maturation.ResultsHeterotopic bone was formed with typical endochondral ossification in Achilles tendons 6 weeks after surgery and continued to enlarge up to 12 weeks. The formation of HO was significantly inhibited with the treatment of tamoxifen at the dosage of 9 mg/kg, whereas 1 mg/kg and 3 mg/kg did not reduce HO bone volume remarkably. The progression of HO was both attenuated by tamoxifen from Day 1 and Week 4 post-surgery, whereas no inhibitory effect was shown at the osteogenesis and maturation stages treated with tamoxifen.ConclusionsTamoxifen exerts an inhibitory effect on the heterotopic bone progression at inflammation and chondrogenesis stages, with the TGF-β signaling pathway suppressed following the increase in estrogen receptor α activity.

Abrupt involution induces inflammation, estrogenic signaling, and hyperplasia linking lack of breastfeeding with increased risk of breast cancer

BackgroundA large collaborative analysis of data from 47 epidemiological studies concluded that longer duration of breastfeeding reduces the risk of developing breast cancer. Despite the strong epidemiological evidence, the molecular mechanisms linking prolonged breastfeeding to decreased risk of breast cancer remain poorly understood.MethodsWe modeled two types of breastfeeding behaviors in wild type FVB/N mice: (1) normal or gradual involution of breast tissue following prolonged breastfeeding and (2) forced or abrupt involution following short-term breastfeeding. To accomplish this, pups were gradually weaned between 28 and 31 days (gradual involution) or abruptly at 7 days postpartum (abrupt involution). Mammary glands were examined for histological changes, proliferation, and inflammatory markers by immunohistochemistry. Fluorescence-activated cell sorting was used to quantify mammary epithelial subpopulations. Gene set enrichment analysis was used to analyze gene expression data from mouse mammary luminal progenitor cells. Similar analysis was done using gene expression data generated from human breast samples obtained from parous women enrolled on a tissue collection study, OSU-2011C0094, and were undergoing reduction mammoplasty without history of breast cancer.ResultsMammary glands from mice that underwent abrupt involution exhibited denser stroma, altered collagen composition, higher inflammation and proliferation, increased estrogen receptor α and progesterone receptor expression compared to those that underwent gradual involution. Importantly, when aged to 4 months postpartum, mice that were in the abrupt involution cohort developed ductal hyperplasia and squamous metaplasia. Abrupt involution also resulted in a significant expansion of the luminal progenitor cell compartment associated with enrichment of Notch and estrogen signaling pathway genes. Breast tissues obtained from healthy women who breastfed for < 6 months vs ≥ 6 months showed significant enrichment of Notch signaling pathway genes, along with a trend for enrichment for luminal progenitor gene signature similar to what is observed in BRCA1 mutation carriers and basal-like breast tumors.ConclusionsWe report here for the first time that forced or abrupt involution of the mammary glands following pregnancy and lack of breastfeeding results in expansion of luminal progenitor cells, higher inflammation, proliferation, and ductal hyperplasia, a known risk factor for developing breast cancer.

Adiposity and estrogen receptor-positive, postmenopausal breast cancer risk: Quantification of the mediating effects of fasting insulin and free estradiol.

Adiposity increases estrogen receptor (ER)-positive postmenopausal breast cancer risk. While mechanisms underlying this relationship are uncertain, dysregulated sex-steroid hormone production and insulin signaling are likely pathways. Our aim was to quantify mediating effects of fasting insulin and free estradiol in the adiposity and ER-positive postmenopausal breast cancer association. We used data from a case-cohort study of sex hormones and insulin signaling nested within the Melbourne Collaborative Cohort Study. Eligible women, at baseline, were not diagnosed with cancer, were postmenopausal, did not use hormone therapy and had no history of diabetes or diabetes medication use. Women with ER-negative disease or breast cancer diagnosis within the first follow-up year were excluded. We analyzed the study as a cumulative sampling case-control study with 149 cases and 1,029 controls. Missing values for insulin and free estradiol were multiply imputed with chained equations. Interventional direct (IDE) and indirect (IIE) effects were estimated using regression-based multiple-mediator approach. For women with body mass index (BMI) >30 kg/m2 compared to women with BMI 18.5-25 kg/m2 , the risk ratio (RR) of breast cancer was 1.75 (95% confidence interval [CI] 1.05-2.91). The estimated IDE (RR) not through the mediators was 1.03 (95% CI 0.43-2.48). Percentage mediated effect through free estradiol was 72% (IIE-RR 1.56; 95% CI 1.11-2.19). There was no evidence for an indirect effect through insulin (IIE-RR 1.12; 95% CI 0.68-1.84; 28% mediated). Our results suggest that circulating free estradiol plays an important mediating role in the adiposity-breast cancer relationship but does not explain all of the association.

1978-P: Possible Regulation between Estrogen and Gas6 Gene in Adipogenesis

Background: The physiological withdrawal of estrogen during menopause brings about changes in fat metabolism. Previous cell-based studies showed estrogen had direct effects on adipocytes. Gas6 is the ligand for the Tyro-3, Axl and Mer (TAM) receptors, and Gas6/TAM signaling stimulates cellular responses. Recent studies indicate that Gas6 gene was involved in adipocyte development, and human Gas6 levels were associated with obesity. Our clinical data showed Gas6 levels were positively correlated with estradiol (E2) levels in the postmenopausal women. However, the regulation mechanism between E2 and Gas6 gene in adipocyte functions is still unknown. In this study, we try to investigate the possible role of Gas6 gene that involved in estrogen effect on adipocyte development. Materials and Methods: Human and mouse adipocyte cell lines, SGBS and 3T3-L1, were used as in vitro cell model and ovariectomy rat was used as the postmenopausal animal model. Results: Our data showed increased estrogen receptor α (ERα) and Gas6 expression after E2 treatment in both SGBS and 3T3-L1 cell lines. Meanwhile, E2 treatment can decrease adipogenesis-related genes expression. Furthermore, we used estrogen antagonism in adipocyte that blocked the ERα and then reduced Gas6 expression and reversed the expression of adipogenesis-related genes. The luciferase assay confirmed that Gas6 gene expression was activated after E2 treatment through the genomic pathway. In addition, estrogen may also regulate Gas6 expression through non-genomic AMPK pathway. Finally, our animal model data showed significantly decreased Gas6 expression in adipose tissue from ovariectomy rats compared to the sham operation group. Interesting, the Gas6 expression in adipose tissue was increased in ovariectomy rats after E2 supplement. Conclusion: Our study first elucidates the E2 effect on adipogenesis-related genes expression and adipocyte function and may partially through genomic and non-genomic pathways to activate Gas6 gene expression. Disclosure C. Lee: None.

Short-term exposure to chrysin promotes proliferative responses in the ventral male prostate and female prostate of adult gerbils.

Chrysin (5,7-dihydroxyflavone) is a bioactive compound found in different fruits, vegetables, honey and propolis. This flavone has been suggested for the treatment of reproductive dysfunction, mainly because of its antioxidant and hormonal properties. However, the effects of this polyphenol on the prostate are still poorly understood. The purpose of this study was to evaluate the effects of short-term chrysin exposure on the ventral male and female prostates of adult gerbils. To evaluate the androgenic potential of chrysin, gerbils were also exposed to testosterone. Male and female gerbils were exposed to chrysin (50mg/kg/day, orally) or testosterone cypionate (1mg/kg/week, subcutaneously) for 3, 7 and 21days. Prostates were dissected for morphological, stereological and immunohistochemical analyses. Serum levels of testosterone and 17β-estradiol were measured by ELISA. Serum testosterone levels were not increased by chrysin supplementation in males or females. However, only females treated with chrysin for 21days showed an increase in estradiol levels. Increased androgen receptor immunoreactivity, higher proliferation rates and glandular hyperplasia were observed in male and female prostates for all chrysin treatment times. Additionally, increased oestrogen receptor alpha immunoreactivity was observed in all chrysin-treated females. Although chrysin and testosterone promoted similar morphological changes in the gerbil prostate, chrysin supplementation was less deleterious to prostate health, since it resulted in lower incidence of hyperplasia and an absence of neoplastic foci.

Both neural and global androgen receptor overexpression affect sexual dimorphism in the mouse brain.

Testosterone is the main endocrine mechanism mediating sexual differentiation of the mammalian brain, although testosterone signalling is complex and important mechanistic questions remain. Notably, the extent to which testosterone acts via androgen receptors (AR) in this process remains unknown and it is also not clear where testosterone acts in the body to produce sexual dimorphisms in neuroanatomy. To address these questions, we used a transgenic mouse model of Cre/loxP-driven AR overexpression in which AR was induced selectively in neural tissue (Nestin-cre) or in all tissues (CMV-cre). We then studied sexually dimorphic features of several well-characterised sexual dimorphisms: calbindin-immunoreactive neurones in the medial preoptic area (CALB-SDN), tyrosine hydroxylase neurones in the anteroventral periventricular nucleus, and vasopressin-immunoreactive neurones originating in the bed nucleus of the stria terminalis and their projections in the lateral septum. We additionally evaluated oestrogen receptor α immunoreactivity in these nuclei. Briefly, we found that global but not neural overexpression of AR resulted in masculinisation of CALB-SDN nucleus volume, cell number and cell size in transgenic females. Furthermore, neural AR overexpression resulted in increased oestrogen receptor α staining in females compared to males in the medial preoptic area. AR overexpression did not affect other measures. Overall, the results of the present study provide support for the hypothesis that androgenic mechanisms external to the nervous system can affect sexual differentiation of the brain.

Activation of Nrf2 attenuates delayed gastric emptying in obesity induced diabetic (T2DM) female mice

Diabetic gastroparesis (GP) is a clinical syndrome characterized by delayed gastric emptying (DGE). Loss of Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) led to reduced nNOSα mediated gastric motility and DGE. The molecular signaling of cinnamaldehyde (CNM) mediated Nrf2 activation and its mechanistic role on DGE were further investigated in obese/T2D female mice. Adult female homozygous Nfe2l2−/− (C57BL/6J) and their wild-type (WT) littermates (Nfe2l2+/+) mice were fed with high fat diet (HFD; Obese/T2D model), or normal diet (ND) with or without CNM (50 mg/kg b.w; i.p). Supplementation of CNM attenuated (p < 0.05) DGE in WT female but not in Nrf2 KO Obese/T2D mice. CNM (1) normalized serum estradiol-17β levels, (2) induced gastric Nrf2 and phase II antioxidant enzymes through extracellular signal-regulated kinase, (ERK)/c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK), (3) reduced glucose synthase kinase 3 beta (GSK3β) and aryl hydrocarbon receptor (AhR) and this was associated with (4) increased estrogen receptor expression, BH4 (Cofactor of nNOS) biosynthesis enzyme GCH-1 and nNOSα dimerization in WT Obese/T2 diabetic female mice. In addition, CNM restored impaired nitrergic relaxation in hyperglycemic conditions. These findings emphasize the importance of Nrf2 in maintaining nNOSα mediated GE and may have a translational relevance to treat obese/diabetic gastroparesis in women.

An increase of estrogen receptor α protein level regulates BDE-209-mediated blood-testis barrier disruption during spermatogenesis in F1 mice.

Deca-bromodiphenyl ether (BDE-209) regulates various aspects of spermatogenesis and male fertility through its effect on estrogen receptor α (ERα), but the underlying mechanism remains unclear. Because molecular mechanisms such as remodeling of the blood-testis barrier (BTB) play crucial roles in spermatogenesis, we investigated the disruptive effects of ERα agonists on the BTB in spermatogenesis. In this study, 0, 300, and 500mg/kg/day of BDE-209 were administered to pregnant adult mice by oral gavage from gestation day 7 to postnatal day 21. SerW3 cells were treated with methylpiperidino pyrazole (MPP) for 30min before being treated with 50μg/mL of BDE-209. BDE-209 increases ERα in time- and dose-dependent manners and decreases formin 1 and BTB-associated protein in F1 male mice. Furthermore, BDE-209 impairs the structure and function of the BTB. Activation of ERα signaling could disrupt the BTB, leading to spermatogenesis dysfunction. The results identified the role of ERα in BTB disruption during spermatogenesis and suggested that BTB disruption occurs because of exposure to BDE-209, which could potentially affect spermatogenesis. In conclusion, Sertoli cells seem to be the primary target of BDE-209 in the perinatal period, and this period constitutes a critical window of susceptibility to BDE-209. Also, the SerW3 cell model may not be a particularly useful cell model for studying the function of the cytoskeleton.

Isopsoralen Enhanced Osteogenesis by Targeting AhR/ERα.

Isopsoralen (IPRN), one of the main effective ingredients in Psoralea corylifolia Linn, has a variety of biological effects, including antiosteoporotic effects. In vivo studies show that IPRN can increase bone strength and trabecular bone microstructure in a sex hormone deficiency-induced osteoporosis model. However, the mechanism underlying this osteogenic potential has not been investigated in detail. In the present study, we investigated the molecular mechanism of IPRN-induced osteogenesis in MC3T3-E1 cells. Isopsoralen promoted osteoblast differentiation and mineralization, increased calcium nodule levels and alkaline phosphatase (ALP) activity and upregulated osteoblast markers, including ALP, runt-related transcription factor 2 (RUNX2), and collagen type I alpha 1 chain (COL1A1). Furthermore, IPRN limited the nucleocytoplasmic shuttling of aryl hydrocarbon receptor (AhR) by directly binding to AhR. The AhR target gene cytochrome P450 family 1 subfamily A member 1 (CYP1A1) was also inhibited in vitro and in vivo. This effect was inhibited by the AhR agonists indole-3-carbinol (I3C) and 3-methylcholanthrene (3MC). Moreover, IPRN also increased estrogen receptor alpha (ERα) expression in an AhR-dependent manner. Taken together, these results suggest that IPRN acts as an AhR antagonist and promotes osteoblast differentiation via the AhR/ERα axis.

NF1 deficiency correlates with estrogen receptor signaling and diminished survival in breast cancer

The key negative regulatory gene of the RAS pathway, NF1, is mutated or deleted in numerous cancer types and is associated with increased cancer risk and drug resistance. Even though women with neurofibromatosis (germline NF1 mutations) have a substantially increased breast cancer risk at a young age and NF1 is commonly mutated in sporadic breast cancers, we have a limited understanding of the role of NF1 in breast cancer. We utilized CRISPR–Cas9 gene editing to create Nf1 rat models to evaluate the effect of Nf1 deficiency on tumorigenesis. The resulting Nf1 indels induced highly penetrant, aggressive mammary adenocarcinomas that express estrogen receptor (ER) and progesterone receptor (PR). We identified distinct Nf1 mRNA and protein isoforms that were altered during tumorigenesis. To evaluate NF1 in human breast cancer, we analyzed genomic changes in a data set of 2000 clinically annotated breast cancers. We found NF1 shallow deletions in 25% of sporadic breast cancers, which correlated with poor clinical outcome. To identify biological networks impacted by NF1 deficiency, we constructed gene co-expression networks using weighted gene correlation network analysis (WGCNA) and identified a network connected to ESR1 (estrogen receptor). Moreover, NF1-deficient cancers correlated with established RAS activation signatures. Estrogen-dependence was verified by estrogen-ablation in Nf1 rats where rapid tumor regression was observed. Additionally, Nf1 deficiency correlated with increased estrogen receptor phosphorylation in mammary adenocarcinomas. These results demonstrate a significant role for NF1 in both NF1-related breast cancer and sporadic breast cancer, and highlight a potential functional link between neurofibromin and the estrogen receptor.