ResearchPad - steroid-and-nuclear-receptors https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[SUN-736 Knockout of Membrane Androgen Receptor ZIP9 Results in Reduced Female Fecundity and Abnormal Egg Activation in Zebrafish]]> https://www.researchpad.co/article/elastic_article_8746 Recently, our research group cloned and characterized a putative membrane androgen receptor from teleost ovarian tissue that was found to be homologous with the zinc transporter protein ZIP9 (Slc39a9). To date, ZIP9 is the only zinc transporter that is known to be ligand activated or possess steroid receptor activity. Since the discovery of its androgen receptor activity, ZIP9 has been found to mediate androgen actions in a variety of tissues including teleost ovarian follicle cells, human cancer cell lines, and murine Sertoli cells. However, ZIP9 has not been examined in an in vivo model so the precise physiological functions of this receptor remain unclear. A ZIP9-mutant strain of zebrafish was developed using a CRISPR-Cas9 system in order to examine the role of the protein in teleost reproduction. While ZIP9-mutant males had similar breeding occurrence and fertilization rates to wild-type fish, mutant females exhibited severe reductions in fecundity compared to wild-type fish. ZIP9-mutant females spawn significantly fewer eggs of which a high proportion failed to undergo chorion elevation, a characteristic of normal egg activation. Eggs that showed this failed chorion elevation phenotype had significantly lower fertilization rates and produced larvae that exhibit a high incidence of pericardial/yolk sac edema and reduced growth compared to larvae hatched from wild-type eggs. However, no differences were observed in the proportions of oocytes at later stages of development between ZIP9-mutant and wild-type fish, suggesting the observed phenotypes are not related to abnormal oogenesis. We observed that mature wild-type eggs have numerous cortically located vesicles that are autofluorescent under ultraviolet light and decrease in number when the eggs undergo activation, suggesting they undergo exocytosis during the cortical reaction. While zinc is known to be stored in vesicles that undergo exocytosis in mammalian eggs, the role of zinc in teleost egg activation is currently unknown. In eggs from wild-type fish, we observed an increase in extracellular zinc levels upon egg activation and treatment with a zinc ionophore (zinc pyrithione) significantly reduced the number of eggs that undergo normal chorion elevation when activated. This suggests a role for zinc in zebrafish egg activation similar to that observed in mammals. Of interest, ZIP9-mutant eggs that did not undergo chorion elevation had significantly smaller vesicles than those found in wild-type fish eggs. This abnormal vesicle morphology and failure to undergo chorion elevation suggest a role of ZIP9 in egg activation. Additional insight into the role of zinc in zebrafish egg activation and the mechanism by which ZIP9 disruption leads to abnormal cortical vesicles and egg activation will help determine if ZIP9 plays a role in zinc transport and flux in zebrafish eggs during activation.

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<![CDATA[SUN-LB136 A Comparison of Androgen Receptor Splice Variant, AR-V7, and Glucocorticoid Receptor Activity in Prostate Cancer]]> https://www.researchpad.co/article/elastic_article_8702 Prostate Cancer (PCa) is an androgen dependent disease and patients with metastatic PCa are treated with androgen deprivation therapy (ADT). Although most tumors respond initially, tumors become resistant and are termed castration resistant prostate cancer (CRPC). There is compelling evidence that most of these tumors retain androgen receptor (AR) dependence and some data to suggest that, in some cases, the glucocorticoid receptor (GR) substitutes for AR. AR, itself, is re-activated through a variety of mechanisms including the expression of constitutively active AR splice variants that lack the ligand binding domain (LBD) of AR. Expression of one variant, AR-V7, which contains the amino-terminal domain and DNA binding domain of AR and 16 unique amino-acids, has been correlated with resistance to second line ADT. Although there has been some debate regarding the role of AR-V7, whether it is only a partial substitute for AR or has unique activities, our studies of engineered cell lines treated to express levels of AR-V7 equivalent to AR, clearly show that while the AR isoforms have common targets, they each also have unique targets. Consistent with this, the cistromes of the two show many unique sites as well as common sites. AR-V7 binding is enriched near the transcription start site (TSS) and we have identified a novel de novo binding motif. These findings suggest the possibility of developing a gene signature unique to AR-V7.Because GR activity in PCa has also been suggested as an escape mechanism in response to ADT, and GR binds to the same consensus response elements, we sought to identify a GR signature in PCa, to compare it with the AR and AR-V7 signatures, and to ask whether the AR-V7 and/or GR signatures are enriched in CRPC. Because much of the gene signatures are cell line dependent, we sought to compare GR and AR-V7 action in cells that express both. LN-95 cells express both AR-V7 and GR. MDA-PCa-2b cells, a cell line derived from an African American patient, expresses GR, but not AR-V7. The parental line was infected with a lentivirus that expresses AR-V7 in response to doxycycline. Transcriptomes were determined for AR, GR, and AR-V7 in these lines using RNA-Seq. Overall the magnitude of regulation of gene expression was generally lower than in the LNCaP AR-V7 and VCaP-AR-V7 lines, but there was good overlap of the MDA-PCa-2b AR-V7 regulated with the LNCaP AR-V7 regulated genes. Genes induced by GR overlapped with AR and isoform common genes, but did not overlap with AR-V7 specific genes. A comparison of AR-V7 specific genes common to the LNCaP and VCaP models as well as to publicly available data sets for LN-95 and 22RV1 AR-V7 signatures, show a strong correlation with CRPC compared to primary tumors when analyzed in the Grasso data set.

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<![CDATA[SUN-739 Next Generation AR Antagonists Increase Systemic Active Glucocorticoid Exposure by Altering Glucocorticoid Metabolism]]> https://www.researchpad.co/article/elastic_article_8693 Enzalutamide and apalutamide are potent next-generation androgen receptor (AR) antagonists used in metastatic and non-metastatic prostate cancer. Despite the increased survival benefits of these agents, resistance normally occurs and the disease transitions to its lethal form. We hypothesized that enzalutamide and apalutamide suppress 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2), which normally converts cortisol to cortisone, leading to elevated cortisol concentrations and increased ratio of active to inactive glucocorticoids. We measured cortisol and cortisol/cortisone ratio (substrate/product of 11β-HSD2) in serum using mass spectrometry before and 1 month on-treatment in 3 clinical trials: 1) neoadjuvant apalutamide + leuprolide (n=25) 2) enzalutamide +/- PROSTVAC for metastatic castration-resistant prostate cancer (n=54) and 3) enzalutamide +/- PROSTVAC for non-metastatic castration-sensitive prostate cancer (n=38 patients). Progression-free survival (PFS) was determined in the metastatic CRPC study of enzalutamide +/- PROSTVAC for those with glucocorticoid changes above and below the median. A statistically significant rise in cortisol concentration and cortisol/cortisone ratio with AR antagonist treatment occurred uniformly across all 3 clinical trials. For example, a rise in cortisol/cortisone ratio occurred in 23/25 (92%) patients (p < 0.001), 36/54 (67%) patients (p < 0.001), and 30/38 (79%) patients (p = 0.051), in the 3 respective trials. In the trial of enzalutamide +/- PROSTVAC for metastatic CRPC, high cortisol/cortisone ratio in the enzalutamide arm was associated with significantly improved PSA progression-free survival and radiographic progression-free survival. However, in the enzalutamide + PROSTVAC arm, the opposite trend was observed. In conclusion, treatment with enzalutamide or apalutamide increases systemic exposure to active glucocorticoids. These findings have potential consequences for immune suppression and the efficacy of treatment combinations using next-generation AR antagonists. On-treatment, glucocorticoid changes might serve as a pharmacodynamic biomarker.

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<![CDATA[OR12-06 Nuclear Receptor CAR Protects Female Mice from the Development of Diet-Induced Nonalcoholic Fatty Liver Disease]]> https://www.researchpad.co/article/elastic_article_8689 NAFLD (Non Alcoholic Fatty Liver Disease) has become the most common cause of chronic liver disease in many developed countries worldwide and represents a major health concern. The prevalence of NAFLD is sexually dimorphic with men suspected to be more susceptible to the development of hepatic steatosis than women. Women are mostly protected until hormonal imbalance induced by menopause. Nuclear receptor CAR (Constitutive Androstan Receptor) is at the crossroads between endocrine and metabolic regulations and could therefore represent an interesting therapeutic target. It is primarily expressed in the liver and involved in the catabolism of hormones such as thyroid hormones, corticosteroids and estrogens. In addition, several studies reveal a metabolic role of CAR through regulation of major hepatic pathways such as neoglucogenesis, beta-oxidation and de novo lipogenesis. Our research is aimed at better understanding the role of CAR using a mouse model genetically deficient for CAR. To explore the metabolic functions of CAR, knock-out male and female mice were subjected to a high fat diet (HFD) for 16 weeks. Concomitant CAR deletion and high fat diet induces sexually dimorphic metabolic disorders. Knock-out of CAR in males exacerbates HFD-induced fasted hyperglycemia whereas in females, it aggravates body weight gain and adipose tissue accumulation. In accordance with epidemiological studies revealing a protection of women from the development of hepatic steatosis, HFD-fed WT female mice present less important hepatic steatosis than HFD-fed WT male mice. However, following CAR deletion, HFD-fed female mice develop a severe steatosis along with important hepatic injury. Ongoing studies aim to understand the transcriptomic and endocrine dysregulations that may explain these phenotypes. These results reveal a previously unrecognized dimorphic role of CAR in energy homeostasis and highlights its involvement in the protection of female mice towards the development of hepatic steatosis. Overall, this research provides further insights in the pathogenesis of NAFLD and its dimorphic prevalence.

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<![CDATA[SUN-740 Low-Dose Dihydrotestosterone Lowers Lipogenic Master Regulator in Liver and Adipose Tissue from Female Mice]]> https://www.researchpad.co/article/elastic_article_8687 Hyperandrogenemia (HA) and insulin resistance (IR) are hallmarks of polycystic ovary syndrome (PCOS), a common endocrine disorder that affects 1 in 10 women. These hallmarks are also integral elements of non-alcoholic liver disease (NALFD), a disorder that is common in women with PCOS. Administering low dose dihydrotestosterone (DHT) induced a lean female mouse model with a PCOS-like phenotype, displaying IR and NAFLD. The molecular mechanism of HA-induced NAFLD has not been determined. We hypothesized that low dose DHT would interrupt hepatic lipid metabolism leading to NAFLD. To investigate the role of androgens on the master regulator of lipogenesis, sterol regulatory element-binding protein 1 (SREBP1), we extracted white adipose tissue (WAT), liver, and skeletal muscle from wild-type, control and low dose DHT female mice; and performed Western blot and real-time quantitative PCR (qRT-PCR) analysis of lipogenic intermediates of the tissue homogenates. Low-dose DHT lowered the active form of cytosolic SREBP1 in the liver and WAT compared to controls. Additionally, low dose DHT lowered inactive SREBP1 in the liver. However, the condition did not alter the levels of the active and inactive forms of SREBP2 in the liver and WAT, though the active form was lowered in skeletal muscle. Further, p-ACC levels were unaltered in liver and WAT. FAS levels were unchanged in WAT and skeletal muscle. Taken together, our findings support the hypothesis that cytosolic SREBP1 decreased due to its translocation to the nucleus, where it regulates lipogenic protein levels. We speculate that low-dose DHT promotes the translocation of SREBP1 from the cytosol to the nucleus to influence lipogenic gene expression leading to increased lipogenesis contributing to NAFLD.

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<![CDATA[SUN-735 Functional Analysis of Testis-Specific Noncoding Genes in Estrogen-Dependent Transcription]]> https://www.researchpad.co/article/elastic_article_8635 Emerging studies have shown that germ cell (GC)-specific genes play critical roles in several cancers. The expression of these genes is tightly regulated and restricted to testis; however, many of them escape regulation and become aberrantly expressed in tumors. Interestingly, our genomic analysis suggests that several of these genes are long noncoding RNAs (lncRNAs) and are located at regions previously considered to be gene deserts in the human genome. In this regard, we used an integrated genomic approach to identify GC-lncRNA genes that are overexpressed in breast cancer. Further, by incorporating gene expression analysis from RNA-seq data from MCF-7 and T47D breast cancer cells, we generated a comprehensive list of estrogen-regulated GC-lncRNA genes. We hypothesize that GC-lncRNA genes regulate estrogen-dependent signaling in breast cancer. The selected genes: (a) CAERRC (Chromatin Associated Estrogen-Regulated RNA in Cancer, (b) LncRNA568, (c) LncRNA16 are primate-specific, and exclusively expressed in testis. All of them are regulated by estrogen, and their expression predicts poor outcome in ERα+ breast cancer patients. They have now been fully annotated (transcription start and stop site, 5’ cap, polyA tail, and exon/intron structure), and cloned. Further, we have created gene-specific KO MCF-7 cell lines using CRISPR to study their molecular roles. Our data suggest that these genes regulate estrogen-dependent gene expression and tumor growth in breast cancer cells. Genome-wide analysis of ERα binding and gene expression data indicate that they play a critical role in the estrogen-dependent transcription. Collectively, our results suggest that GC-genes, including CAERRC, LncRNA568, and LncRNA16, are excellent targets with prognostic and therapeutic potential in ER+ breast cancers.

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<![CDATA[OR12-03 Mineralocorticoid and Glucocorticoid Receptors Adopt Distinct Quaternary Structures and Can Form Heteromultimers That Affect Chromatin-Binding Profiles]]> https://www.researchpad.co/article/elastic_article_8612 The mineralocorticoid and glucocorticoid receptors (MR and GR) are evolutionarily related nuclear receptors with high sequence conservation and a shared hormone response element (HRE). Both receptors are activated by glucocorticoids, but MR can be selectively activated by aldosterone. Using the imaging technique Number & Brightness (N&B) it has recently been proposed that liganded GR dimers form tetramers upon binding to HREs in live cells. We now show that agonist-bound MR adopts a tetrameric organization in the nucleoplasm and forms complexes with an average of 7 receptor units upon binding an HRE. Interestingly, MR antagonists eplerenone and spironolactone induced intermediate oligomerization arrangements, strongly suggesting that higher order oligomerization is essential for receptor activity. Site-directed mutagenesis and deletion analysis suggest that the N-terminus of MR is a main determinant of higher order oligomerization. Both with corticosterone and aldosterone, GR can incorporate into MR complexes partially displacing MR monomers. Genome-wide chromatin binding studies suggest that the presence of GR in the same cells profoundly change MR interaction with distinct sets of enhancers in a ligand-dependent way, contributing to receptor-specific signaling. Certain genes respond to only one receptor while others respond to both receptors. The interaction of these two closely related receptors has important implications for the mechanisms for glucocorticoid signaling and transcription factors in general.

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<![CDATA[SUN-LB134 Androgen Receptor Phosphorylated at Serine 815 in Mouse and Human Prostates]]> https://www.researchpad.co/article/elastic_article_6854 Androgen receptor (AR) regulates male sexual development and maintenance. AR forms a homodimer in the cytoplasm and monomerizes following hormonal activation, translocating to the nucleus in Cos-1 cells (Shizu et al. Scientific reports. 2019). Utilizing Ser815 of AR, the conserved phosphorylation residue within the ligand binding domains of steroid hormone receptors (NR3C), whether and how this phosphorylation regulates AR functions was investigated. While, like AR WT, a phosphomimic AR S815D mutant formed a homodimer in the cytoplasm, unlike the WT, this mutant remained as a homodimer in the cytoplasm even after hormone treatment. Apparently, Ser815 phosphorylation disabled AR’s capability to monomerize and nuclear translocate in Cos-1 cells. A phospho-Ser815 peptide antibody was used to detect phosphorylation of endogenous AR in mouse as well as human prostates. Immunohistochemistry showed phosphorylation present in both the cytoplasm and nucleus. Mouse prostates were cell fractionated in cell membrane, mitochondria, endoplasmic reticulum (ER) and cytosolic fractions for subsequent Western blot analysis. While AR was found in all of these fractions, phosphorylated AR was only detected in the ER and cytosolic fractions. A cDNA microarray analysis of PC-3 cells with ectopic expression of AR S815D suggested that phosphorylated AR may regulate ER stress.

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<![CDATA[OR12-04 Regulatory Sharing between Estrogen Receptor Alpha Bound Enhancers]]> https://www.researchpad.co/article/elastic_article_6850 Mammalian genomes encode an order of magnitude more gene expression enhancers than promoters, suggesting that most genes are regulated by combinations of enhancers. We previously found that neighboring estrogen-responsive enhancers exhibit cooperative/synergistic contributions to an estrogenic transcriptional response1. However, when the same combinations of enhancers are targeted with synthetic activators in the absence of estrogens, then the regulatory regions exhibit independent effects on gene expression2. Taken together, these findings indicate that estrogen receptor alpha (ER) bound enhancers cooperate with each other in cis but influence target gene promoters independently. To determine the molecular underpinnings of enhancer cooperativity, we generated genetic deletions of individual ER bound enhancers. We discovered “regulatory sharing” between enhancers in which loci containing full estrogen response elements (EREs) contribute ER binding to neighboring sites, while enhancers with pre-existing histone acetylation/accessibility contribute this permissible chromatin environment to the neighboring enhancers upon estrogen induction. Genome engineering revealed that a cluster of two half ERE enhancers could not compensate for a full ERE site loss within the cluster. However, two full ERE enhancers produced a transcriptional response greater than the wild-type locus, suggesting that combinations of enhancers are not necessarily configured for a maximal response. By swapping genomic sequences, we found that the genomic location in which a full ERE resides strongly influences enhancer activity. Our results lead to a model in which a full ERE is critical for ER recruitment, but the presence of pre-existing histone acetylation and accessibility within an enhancer cluster is also needed in order for estrogen-induced gene regulation to occur.

References 1. Carleton JB, Berrett KC, Gertz J (2017). Multiplex Enhancer Interference Reveals Collaborative Control of Gene Regulation by Estrogen Receptor α-Bound Enhancers. Cell Syst, 5(4), 333-344.e5.2. 2. Ginley-Hidinger M, Carleton JB, Rodriguez AC, Berrett KC, Gertz J. Sufficiency analysis of estrogen responsive enhancers using synthetic activators. Life Sci Alliance, 2(5).

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<![CDATA[SUN-746 Thyroid Hormone Receptor Alpha Sumoylation Is Important for the Development of Adipose Tissue]]> https://www.researchpad.co/article/elastic_article_6632 Thyroid hormone (TH) plays an essential role in normal development. TH action requires binding to its receptor. There are two types of thyroid hormone receptor, alpha (THRA) and beta (THRB). THRB is important for regulation of the Hypothalamic-Pituitary-Thyroid axis and regulating cholesterol metabolism. THRA is involved in the development and the function of brain, adipose tissue, small intestine, bone and heart. Both THRA and THRB are post-translationally modified by small ubiquitin-like modifier (SUMO). Previously, we showed in an in vitro model that mutation of a THRA sumoylation motif impairs proliferation and differentiation of human primary white adipocytes. This is due to interference of the desumolyated THRA in the cell cycle at G1/S phase and disruption of PPAR signaling. To determine the in vivo effects of a desumoylated THRA, we generated a mouse model carrying a mutation of the THRA gene, which eliminates SUMO conjugation at lysine (K) 283. At 12 weeks of age, there was no difference in body composition (body weight, fat mass, and lean mass) in THRA mutant mice compared to wild-type (WT). From 12 weeks onward mutant mice and WT did not have significant change body weight compared to Wt mice. However, THRA sumoylation mutant mice had much lower percent body fat. Dissected WAT fat pads from mutant mice were significantly smaller compared to WT mice. Histological analysis showed that the cell size of white adipose tissue in mutant mice was significantly smaller than that in Wt mice as well. Serum leptin levels in the mutant mice were significantly lower than that in mice, consistent with reduced fat mass. We isolated fat stem cells from stromal vesicular fraction of 6 week old mice and found that the number of fat stem cells was significant less in mutant mice compared to those in WT mice. This data suggest that de-sumoylated THRA is associated with reduced fat stem cells at a young age, resulting in reduced adipose tissue mass in adult. THRA sumoylation is important for thyroid hormone modulation of fat mass.

Reference: (1) Yan-Yun Liu et al, JBC 2012 (2) Yan-Yun Liu et al., JBC 2015

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<![CDATA[SUN-743 Understanding the Role of Pancreas and Testis Specific lncRNA86 in Estrogen-Dependent Signaling in Breast Cancer]]> https://www.researchpad.co/article/elastic_article_6596 Long noncoding RNAs (lncRNAs) are emerging as key regulators of diverse cellular processes, but their roles in breast cancer biology are just beginning to be elucidated. In this study, integration of powerful techniques, RNA-seq data from subcellular fractionated RNA with GRO-seq data has yielded a comprehensive catalog of estrogen-regulated lncRNAs in MCF-7 cells. Analysis of RNA-seq data from samples representing molecular subtypes of breast cancer and normal tissue types, revealed that many lncRNAs (such as lincRNA86) show distinct expression patterns. LincRNA86 shows highest normal expression in pancreas followed by testis in normal human tissues. The hypothesis is lincRNA86 regulate estrogen-dependent signaling in breast cancer. In functional assays, knockdown of lncRNA86 inhibits the growth of ER-positive breast cancer cells. Amplified expression of lncRNA86 in breast cancer correlates with clinical outcome. LncRNA86 have now been fully annotated (transcription start and stop site, 5’ cap, polyA tail, and exon/intron structure), and cloned. We are now performing detailed molecular analyses to better understand the underlying mechanisms of action of the lncRNA. We are also currently have experiments underway to view cancer phenotypes: estrogen-dependent tumor growth. Collectively, our preliminary results suggest that lincRNA86 plays a critical role in ERα-dependent pathways.

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<![CDATA[SUN-747 Steroid Hormone Metabolism Mediated Racial Disparity in Men with Benign Prostatic Hyperplasia]]> https://www.researchpad.co/article/elastic_article_5940 Introduction and Objective: Racial disparity in prostate cancer has been well established, with African American (AA) men having higher rates of diagnoses and death from the disease compared to Caucasian American (CA) men. AA men also have a high incidence of benign prostatic hyperplasia (BPH), a disease associated with lower urinary tract symptoms (LUTS) that affect >210 million men worldwide. Furthermore, AA men with BPH have an increased incidence of non-surgical treatment failure, larger prostates at time of surgery, and surgery occurring at a younger age. The use of selective estrogen receptor modulators (SERMs) in the treatment of BPH has been proposed, as an increase in ERα has been associated with disease progression. AA men have higher levels of circulating estrogens as compared to CA leading to an increased prenatal exposure to estrogens. Estrogen exposure has been shown to alter the epigenetic landscape of genes, and this prenatal exposure to estrogens could sensitize the AA men to altered steroid homeostasis leading to an increase susceptibility to BPH and an altered response to treatment. In this study, we examine the prostate expression and localization changes in estrogen receptors (ERα, ERβ) as well as steroid metabolism genes in AA and CA with or without BPH. Methods: To examine the impact of race on BPH, we examined prostate tissue from 66 men. We utilized 21 normal transition zone controls from radical prostatectomies, 8 normal transition zone controls from organ donors, and 37 BPH samples divided between CA and AA men. Using multispectral quantitative multiplex IHC, we examined the steroid hormone related protein expression of ERα, ERβ, CYP7B1, and AKR1C1 on each FFPE tissue section. We quantified the optical density of each protein of interest as well as examined colocalization and coexpression through cell and tissue segmentation. Results: In CA men, there is a dysregulation of ERα:ERβ homeostasis with BPH relative to normal as an increase in ERα and a decrease in ERβ expression was observed. Furthermore, an increase in CYP7B1, an enzyme that degrades ERβ ligands, was also observed. In AA men, we observed no difference between normal and BPH states, however in both normal and BPH prostate tissues, ERα and ERβ were increased relative to CA men. In addition, there is a decrease in AKR1C1, the enzyme that metabolizes DHT to an ERβ ligand. Conclusions: Our study supports the concept that differences in hormone pathways exist between AA and CA men. Understanding how these racial difference in steroid metabolism enzymes as well as ERs between CA and AA men with BPH could enhance treatment strategies for men with BPH.

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<![CDATA[SUN-737 Induction of the Pro-Diabetic Gene DPP4 by Glucocorticoids: New Evidence of Pro-Inflammatory Effects in Macrophages]]> https://www.researchpad.co/article/N6cd13fc5-defb-42a7-b484-72d038643213 Glucocorticoids are potent endogenous anti-inflammatory molecules, with its receptor (GR) expressed in nearly all immune cells. Macrophages are heterogeneous cells having a central role in both tissue homeostasis and inflammation. Paradoxically glucocorticoids have a limited efficacy controlling these processes and inflammation resolution of macrophage-related diseases, such as type 2 diabetes, atherosclerosis and rheumatoid arthritis. To address this issue, we explored new glucocorticoid target genes in macrophages with potential clinical and therapeutic implications for these diseases. Analysis of genomic platforms identified the pro-diabetic exopeptidase dipeptidyl peptidase 4 (DPP4) as a novel glucocorticoid-responsive gene. GR directly induces its expression by binding to two glucocorticoid-responsive elements within the DPP4 promoter. Unexpectedly, DPP4 mediated the glucocorticoid-induced spontaneous macrophage migration. These actions were blocked by both GR and DPP4 siRNA knockdowns. Furthermore, two DPP4 inhibitors, Sitagliptin and Linagliptin, used clinically for the treatment of diabetes inhibited glucocorticoid-induced mobility of macrophages. DPP4 induction by glucocorticoids was also observed in murine peritoneal macrophages and pro-inflammatory M1 polarized macrophages and was associated with an increase in their migratory properties. Provocatively, DPP4 has been shown to be involved in the inflammatory macrophage profile associated with type 2 diabetes, obesity and atherosclerosis. Since macrophages require efficient cell movement for all their functions, such as sensing of Pattern Associated Molecular Patterns (PAMPs), phagocytosis and the antigen presentation, the DPP4 induction by glucocorticoids could potentiate the macrophage infiltration and their activation in chronic inflammatory tissues and diabetes.

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<![CDATA[SUN-738 Establishing the Link Between Genetic Variations of Estrogen Receptor 2 and Unexplained Infertility]]> https://www.researchpad.co/article/N63ea47ab-eaa0-40cb-982a-b2419a3ce3e6 Abstract Background: Unexplained or idiopathic infertility comprises approximately 30% of couples who present with infertility. This has led to investigations seeking to determine the cause(s) of this important diagnosis of exclusion. Estrogen’s role in reproduction has been well- established. Estrogens bind to two hormone receptors (namely estrogen receptor-alpha and estrogen receptor-beta), which are distributed differentially throughout the body. Specifically, the estrogen receptor-beta, coded by the Estrogen Receptor 2 (ESR2) gene, is highly expressed in granulosa cells and growing follicles. The one female patient reported with an ESR2 mutation presented with hypergonadotropic hypogonadism. However, subfertility with inefficient ovulation and resistance to exogenous ovulatory stimulation is seen in an ESR2 knockout mouse model. We therefore hypothesized that less severe ESR2 variants could lead to a normal female phenotype and pubertal development but could be a cause subfertility. Methods: DNA samples from 200 women with unexplained infertility were obtained from the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) clinical trial, which investigated optimal ovulation induction medications for unexplained infertility. These samples were subjected to targeted next-generation sequencing (NGS) for the ESR2 gene. Likely pathogenic variants that occurred with a minor allele frequency of < 0.01 in the gnomAD database and a Combined Annotation Dependent Depletion (CADD) score of > 20 were selected for confirmation by Sanger sequencing. Results: From the 200 patient samples, five heterozygous missense variants and one heterozygous in-frame deletion identified by targeted NGS were confirmed by Sanger sequencing. Further studies will need to be performed in vitro to confirm the likely pathogenicity of these variants.Conclusion: These studies raise the possibility that If these variants in ESR2 that impair estrogen signaling, they could be a potential newly recognized etiology of unexplained infertility in women with unexplained infertility. Conclusion: These studies raise the possibility that variants in ESR2 that impair estrogen signaling could be a potential newly recognized etiology of unexplained infertility in women. ]]> <![CDATA[SUN-734 The Role of Chromatin-Associated LncRNA161 in Estrogen-Dependent Transcription]]> https://www.researchpad.co/article/N350b711f-a215-4936-a41b-add80aeff4e7 <![CDATA[SUN-LB138 Dynamic Structural Model of Testosterone Entry Into the Unliganded Androgen Receptor]]> https://www.researchpad.co/article/N04a04b68-f16b-4614-8eb1-d7fdb3138ca8 <![CDATA[SUN-737 Induction of the Pro-Diabetic Gene DPP4 by Glucocorticoids: New Evidence of Pro-Inflammatory Effects in Macrophages]]> https://www.researchpad.co/article/N7946508a-2040-46be-a9b4-6d657f9ae93c

Abstract

Glucocorticoids are potent endogenous anti-inflammatory molecules, with its receptor (GR) expressed in nearly all immune cells. Macrophages are heterogeneous cells having a central role in both tissue homeostasis and inflammation. Paradoxically glucocorticoids have a limited efficacy controlling these processes and inflammation resolution of macrophage-related diseases, such as type 2 diabetes, atherosclerosis and rheumatoid arthritis. To address this issue, we explored new glucocorticoid target genes in macrophages with potential clinical and therapeutic implications for these diseases. Analysis of genomic platforms identified the pro-diabetic exopeptidase dipeptidyl peptidase 4 (DPP4) as a novel glucocorticoid-responsive gene. GR directly induces its expression by binding to two glucocorticoid-responsive elements within the DPP4 promoter. Unexpectedly, DPP4 mediated the glucocorticoid-induced spontaneous macrophage migration. These actions were blocked by both GR and DPP4 siRNA knockdowns. Furthermore, two DPP4 inhibitors, Sitagliptin and Linagliptin, used clinically for the treatment of diabetes inhibited glucocorticoid-induced mobility of macrophages. DPP4 induction by glucocorticoids was also observed in murine peritoneal macrophages and pro-inflammatory M1 polarized macrophages and was associated with an increase in their migratory properties. Provocatively, DPP4 has been shown to be involved in the inflammatory macrophage profile associated with type 2 diabetes, obesity and atherosclerosis. Since macrophages require efficient cell movement for all their functions, such as sensing of Pattern Associated Molecular Patterns (PAMPs), phagocytosis and the antigen presentation, the DPP4 induction by glucocorticoids could potentiate the macrophage infiltration and their activation in chronic inflammatory tissues and diabetes.

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<![CDATA[OR12-07 Full Antagonism of Breast Cancer Cell Proliferation Can Result from Many Ligand-Induced Conformational Distortions of the Estrogen Receptor Ligand Binding Domain]]> https://www.researchpad.co/article/Ndebb1ea9-c247-4e4a-b893-14ef00d0b813 <![CDATA[SUN-751 RORγ Is a Master Regulator of Tumor Lipid Metabolism]]> https://www.researchpad.co/article/N91f154de-95ef-48ca-a46c-22961dd3781d <![CDATA[SUN-742 Roles of Progesterone Receptor Isoform B in Non-Small Cell Lung Cancer Tumor Progression]]> https://www.researchpad.co/article/Ne68308de-651d-4522-b208-7c3d8865cc17