Steroid Hormone Receptor Signals as Prognosticators for Urothelial Tumor

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Hiroki Ide

2015-01-01

Full Text Available There is a substantial amount of preclinical or clinical evidence suggesting that steroid hormone receptor-mediated signals play a critical role in urothelial tumorigenesis and tumor progression. These receptors include androgen receptor, estrogen receptors, glucocorticoid receptor, progesterone receptor, vitamin D receptor, retinoid receptors, peroxisome proliferator-activated receptors, and others including orphan receptors. In particular, studies using urothelial cancer tissue specimens have demonstrated that elevated or reduced expression of these receptors as well as alterations of their upstream or downstream pathways correlates with patient outcomes. This review summarizes and discusses available data suggesting that steroid hormone receptors and related signals serve as biomarkers for urothelial carcinoma and are able to predict tumor recurrence or progression.

Efficacy of chemotherapy after hormone therapy for hormone receptor-positive metastatic breast cancer.

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Mori, Ryutaro; Nagao, Yasuko

2014-01-01

According to the guidelines for metastatic breast cancer, hormone therapy for hormone receptor-positive metastatic breast cancer without life-threatening metastasis should be received prior to chemotherapy. Previous trials have investigated the sensitivity of chemotherapy for preoperative breast cancer based on the efficacy of neoadjuvant hormone therapy. In this retrospective study, we investigated the efficacy of chemotherapy for metastatic breast cancer in hormone therapy-effective and hormone therapy-ineffective cases. Patients who received chemotherapy after hormone therapy for metastatic breast cancer between 2006 and 2013 at our institution were investigated. A total of 32 patients received chemotherapy after hormone therapy for metastatic breast cancer. The median patient age was 59 years, and most of the primary tumors exhibited a T2 status. A total of 26 patients had an N(+) status, while 7 patients had human epidermal growth factor receptor 2-positive tumors. A total of 13 patients received clinical benefits from hormone therapy, with a rate of clinical benefit of subsequent chemotherapy of 30.8%, which was not significantly different from that observed in the hormone therapy-ineffective patients (52.6%). A total of 13 patients were able to continue the hormone therapy for more than 1 year, with a rate of clinical benefit of chemotherapy of 38.5%, which was not significantly different from that observed in the short-term hormone therapy patients (47.4%). The luminal A patients were able to continue hormone therapy for a significantly longer period than the non-luminal A patients (median survival time: 17.8 months vs 6.35 months, p = 0.0085). However, there were no significant differences in the response to or duration of chemotherapy. The efficacy of chemotherapy for metastatic breast cancer cannot be predicted based on the efficacy of prior hormone therapy or tumor subtype, and clinicians should administer chemotherapy in all cases of

Revisiting available knowledge on teleostean thyroid hormone receptors.

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Lazcano, Iván; Orozco, Aurea

2018-03-21

Teleosts are the most numerous class of living vertebrates. They exhibit great diversity in terms of morphology, developmental strategies, ecology and adaptation. In spite of this diversity, teleosts conserve similarities at molecular, cellular and endocrine levels. In the context of thyroidal systems, and as in the rest of vertebrates, thyroid hormones in fish regulate development, growth and metabolism by actively entering the nucleus and interacting with thyroid hormone receptors, the final sensors of this endocrine signal, to regulate gene expression. In general terms, vertebrates express the functional thyroid hormone receptors alpha and beta, encoded by two distinct genes (thra and thrb, respectively). However, different species of teleosts express thyroid hormone receptor isoforms with particular structural characteristics that confer singular functional traits to these receptors. For example, teleosts contain two thra genes and in some species also two thrb; some of the expressed isoforms can bind alternative ligands. Also, some identified isoforms contain deletions or large insertions that have not been described in other vertebrates and that have not yet been functionally characterized. As in amphibians, the regulation of some of these teleost isoforms coincides with the climax of metamorphosis and/or life transitions during development and growth. In this review, we aimed to gain further insights into thyroid signaling from a comparative perspective by proposing a systematic nomenclature for teleost thyroid hormone receptor isoforms and summarize their particular functional features when the information was available. Copyright © 2018 Elsevier Inc. All rights reserved.

Application of hormone receptor assay for clinical chemistry

International Nuclear Information System (INIS)

Sato, Seiya

1978-01-01

A conception of hormone receptors was explained to understand radioreceptor assay (RRA), and various problems in the operation of this method were described mainly. The principle of RRA is the same as that of RIA and CPBA, and measured values by RRA resembled to those by bioassay more closely than those by RIA. However, the sensitivity of RRA was inferior to that of RIA. It was important in using this method especially for measurement of peptide hormone not to deactivate biological the base by radioactivation. As the significance of this method in clinical chemistry, it was mentioned that this method was one kind of experiment to observe the biological activity of hormones, and that properties analysis of receptors, studies on action mechanism, the structure and function of hormone, the pathological analysis of endocrine abnormalities, and the development of drugs and treatment methods for receptors may become possible by this method. The other usefulness of this method was also mentioned. (Kanao, N.)

Application of hormone receptor assay for clinical chemistry

Energy Technology Data Exchange (ETDEWEB)

Sato, S [Kitasato Univ. Hospital, Sagamihara, Kanagawa (Japan)

1978-06-01

A conception of hormone receptors was explained to understand radioreceptor assay (RRA), and various problems in the operation of this method were described mainly. The principle of RRA is the same as that of RIA and CPBA, and measured values by RRA resembled to those by bioassay more closely than those by RIA. However, the sensitivity of RRA was inferior to that of RIA. It was important in using this method especially for measurement of peptide hormone not to deactivate biological the base by radioactivation. As the significance of this method in clinical chemistry, it was mentioned that this method was one kind of experiment to observe the biological activity of hormones, and that properties analysis of receptors, studies on action mechanism, the structure and function of hormone, the pathological analysis of endocrine abnormalities, and the development of drugs and treatment methods for receptors may become possible by this method. The other usefulness of this method was also mentioned.

Grain Filling Characteristics and Their Relations with Endogenous Hormones in Large- and Small-Grain Mutants of Rice.

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Zhang, Weiyang; Cao, Zhuanqin; Zhou, Qun; Chen, Jing; Xu, Gengwen; Gu, Junfei; Liu, Lijun; Wang, Zhiqin; Yang, Jianchang; Zhang, Hao

2016-01-01

This study determined if the variation in grain filling parameters between two different spikelet types of rice (Oryza sativa L.) is regulated by the hormonal levels in the grains. Two rice mutants, namely, a large-grain mutant (AZU-M) and a small-grain mutant (ZF802-M), and their respective wild types (AZU-WT and ZF802-WT) were grown in the field. The endosperm cell division rate, filling rate, and hormonal levels: zeatin + zeatin riboside (Z+ZR), indo-3-acetic acid (IAA), polyamines (PAs), and abscisic acid (ABA) were determined. The results showed that there was no significant difference between the filling and endosperm cell division rates. These rates were synchronous between the superior and inferior spikelets for both mutants. However, the abovementioned parameters were significantly different between the two spikelet types for the two wild types. The superior spikelets filled faster and their filling rate was higher compared to the inferior ones. Changes in the concentrations of plant hormones were consistent with the observed endosperm cell division rate and the filling rate for both types of spikelets of mutant and wild type plants. Regression analysis showed a significant positive correlation between cell division and filling rates with the concentrations of the investigated hormones. Exogenous chemical application verified the role of ABA, IAA, and PAs in grain filling. The results indicate that poor filling of inferior spikelets in rice occurs primarily due to the reduced hormone concentrations therein, leading to lower division rate of endosperm cells, fewer endosperm cells, slower filling rate, and smaller grain weight.

Grain Filling Characteristics and Their Relations with Endogenous Hormones in Large- and Small-Grain Mutants of Rice.

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Weiyang Zhang

Full Text Available This study determined if the variation in grain filling parameters between two different spikelet types of rice (Oryza sativa L. is regulated by the hormonal levels in the grains. Two rice mutants, namely, a large-grain mutant (AZU-M and a small-grain mutant (ZF802-M, and their respective wild types (AZU-WT and ZF802-WT were grown in the field. The endosperm cell division rate, filling rate, and hormonal levels: zeatin + zeatin riboside (Z+ZR, indo-3-acetic acid (IAA, polyamines (PAs, and abscisic acid (ABA were determined. The results showed that there was no significant difference between the filling and endosperm cell division rates. These rates were synchronous between the superior and inferior spikelets for both mutants. However, the abovementioned parameters were significantly different between the two spikelet types for the two wild types. The superior spikelets filled faster and their filling rate was higher compared to the inferior ones. Changes in the concentrations of plant hormones were consistent with the observed endosperm cell division rate and the filling rate for both types of spikelets of mutant and wild type plants. Regression analysis showed a significant positive correlation between cell division and filling rates with the concentrations of the investigated hormones. Exogenous chemical application verified the role of ABA, IAA, and PAs in grain filling. The results indicate that poor filling of inferior spikelets in rice occurs primarily due to the reduced hormone concentrations therein, leading to lower division rate of endosperm cells, fewer endosperm cells, slower filling rate, and smaller grain weight.

Transcriptional activation by the thyroid hormone receptor through ligand-dependent receptor recruitment and chromatin remodelling.

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Grøntved, Lars; Waterfall, Joshua J; Kim, Dong Wook; Baek, Songjoon; Sung, Myong-Hee; Zhao, Li; Park, Jeong Won; Nielsen, Ronni; Walker, Robert L; Zhu, Yuelin J; Meltzer, Paul S; Hager, Gordon L; Cheng, Sheue-yann

2015-04-28

A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co-repressors and facilitates recruitment of co-activators to activate transcription. Here we show that in addition to hormone-independent TR occupancy, ChIP-seq against endogenous TR in mouse liver tissue demonstrates considerable hormone-induced TR recruitment to chromatin associated with chromatin remodelling and activated gene transcription. Genome-wide footprinting analysis using DNase-seq provides little evidence for TR footprints both in the absence and presence of hormone, suggesting that unliganded TR engagement with repressive complexes on chromatin is, similar to activating receptor complexes, a highly dynamic process. This dynamic and ligand-dependent interaction with chromatin is likely shared by all steroid hormone receptors regardless of their capacity to repress transcription in the absence of ligand.

Study of goldfish (Carassius auratus) growth hormone structure-function relationship by domain swapping.

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Chan, Y H; Cheng, C H K; Chan, K M

2007-03-01

Using goldfish as a model, the structure-function relationship of goldfish growth hormone was studied using the strategy of homologous domain swapping. Chimeric mutants were constructed by exchanging homologous regions between goldfish growth hormone (gfGH II) and goldfish prolactin (gfPRL) with their cloned complementary DNAs. Six mutants, with their domain-swapped, were generated to have different combinations of three target regions, including the helix a, helix d and the large section in between these helices (possess the helices b, c and other random coiled regions). After expression in E. coli and refolding, these mutants were characterized by using competitive receptor binding assay (RRA) and growth hormone responding promoter activation assay. The different activity profiles of mutants in Spi 2.1 gene promoter assays from that in RRA shows that, for gfGH, receptor binding dose not confer receptor signal activations. When either helices a or d of gfGH was maintained with other helices replaced by their gfPRL counterparts, both receptor binding and hence gene activation activities are reduced. In mutants with helices b and c in gfGH maintained, containing the gfGH middle section, and helices a and d swapped with gfPRL, the had reduced RRA activities but the promoter activation activities retained. In conclusion, as in the case of human GH, the gfGH molecule possesses two functional sites: one of them is composed of discontinuous epitopes located on the target regions of this study and is for receptor binding; another site is located on the middle section of the molecule that helices a and d are not involved, and it is for activation of GH receptor and intracellular signals.

Endocrine therapy use among elderly hormone receptor-pos...

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U.S. Department of Health & Human Services — Clinical guidelines recommend that women with hormone-receptor positive breast cancer receive endocrine therapy (selective estrogen receptor modulators or aromatase...

Characterization of the hormone-binding domain of the chicken c-erbA/thyroid hormone receptor protein

DEFF Research Database (Denmark)

Muñoz, A; Zenke, M; Gehring, U

1988-01-01

mutations present in the carboxy-terminal half of P75gag-v-erbA co-operate in abolishing hormone binding, and that the ligand-binding domain resides in a position analogous to that of steroid receptors. Furthermore, a point mutation that is located between the putative DNA and ligand-binding domains of P75......To identify and characterize the hormone-binding domain of the thyroid hormone receptor, we analyzed the ligand-binding capacities of proteins representing chimeras between the normal receptor and P75gag-v-erbA, the retrovirus-encoded form deficient in binding ligand. Our results show that several......gag-v-erbA and that renders it biologically inactive fails to affect hormone binding by the c-erbA protein. These results suggest that the mutation changed the ability of P75gag-v-erbA to affect transcription since it also had no effect on DNA binding. Our data also suggest that hormone...

Steroidal Hormone Receptor Expression in Male Breast Cancer

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Fatemeh Homaei-Shandiz

2014-01-01

Full Text Available Introduction: The etiology of male breast cancer is unclear, but hormonal levels may play a role in development of this disease. It seems that the risk of male breast cancer related to increased lifelong exposure to estrogen or reduced androgen. The aim of this study was to investigate the expression of the steroid hormone receptors including estrogen receptor (ER and progesterone receptor (PR in Iranian cases with male breast cancer. Methods: This is a prospective review of 18 cases of male breast cancer in in Omid Hospital, Mashhad, North East of Iran, between October 2001 and October 2006. ER and PR were measured by immunohistochemistry. Clinicopathologic features and family history were obtained by interview. Data were analyzed with SPSS 13 using descriptive statistics.  Results: The median age was 63.2 year. All the cases were infiltrating ductal carcinoma. A high rate of expression of ER (88.8% and PR (66.6% was found in the studied cases. Conclusion: Cancers of the male breast are significantly more likely than cancers of the female breast to express hormonal receptors.

Structure and proteolysis of the growth hormone receptor on rat hepatocytes

International Nuclear Information System (INIS)

Yamada, K.; Lipson, K.E.; Donner, D.B.

1987-01-01

125 I-Labeled human growth hormone is isolated in high molecular weight (M/sub r/) (300,000, 220,000, and 130,000) and low molecular weight complexes on rat hepatocytes after affinity labeling. The time-dependent formation of low molecular weight complexes occurred at the expense of the higher molecular weight species and was inhibited by low temperature or inhibitors of serine proteinases. Exposure to reducing conditions induced loss of M/sub r/ 300,000 and 220,000 species and augmented the amount of M/sub r/ 130,000 complexes. The molecular weight of growth hormone (22,000) suggests that binding had occurred with species of M/sub r/ 280,000, 200,000, and 100,000. Two-dimensional gel electrophoresis demonstrated that the 100,000-dalton receptor subunit is contained in both the 280,000- and 200-000-dalton species. Reduction of interchain disulfide bonds in the growth hormone receptor did not alter its elution from gel filtration columns, but intact, high molecular weight receptor constituents were separated from lower molecular weight degradation products. Digestion of affinity-labeled growth hormone-receptor complexes with neuraminidase increased the mobility of receptor constituents on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These observations show that the growth hormone receptor is degraded by hepatic serine proteinases to low molecular weight degradation products which can be separated from intact receptor by gel filtration. Intact hormone-receptor complexes are aggregates of 100,000-dalton sialoglycoprotein subunits held together by interchain disulfide bonds and by noncovalent forces

The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects

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Farhad Dehkhoda

2018-02-01

Full Text Available The growth hormone receptor (GHR, although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK–signal transducer and activator of transcription (STAT signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK–STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.

Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.

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Martari, Marco; Salvatori, Roberto

2009-01-01

The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.

Radioreceptor assays: plasma membrane receptors and assays for polypeptide and glycoprotein hormones

International Nuclear Information System (INIS)

Schulster, D.

1977-01-01

Receptors for peptide, protein and glycoprotein hormones, and the catecholamines are located on the plasma membranes of their target cells. Preparations of the receptors may be used as specific, high-affinity binding agents for these hormones in assay methodology akin to that for radioimmunoassay. A particular advantage of the radioreceptor assay is that it has a specificity directed towards the biologically active region of the hormone, rather than to some immunologically active region that may have little (or no) involvement in the expression of hormonal activity. Methods for hormone receptor preparation vary greatly, and range from the use of intact cells (as the source of hormone receptor) to the use of purified or solubilized membrane receptors. Receptors isolated from plasma membranes have proved to be of variable stability, and may be damaged during preparation and/or storage. Moreover, since they are present in relatively low concentration in the cell, their preparation in sufficient quantity for use in a radioreceptor assay may present technical problems. In general, there is good correlation between radioreceptor assays and in-vitro bioassays; differences between results from radioreceptor assays and radioimmunoassays are similar to those noted between in-vitro bioassays and radioimmunoassays. The sensitivity of the method is such that normal plasma concentrations of various hormones have been assayed by this technique. (author)

Interaction of a non-peptide agonist with angiotensin II AT1 receptor mutants

DEFF Research Database (Denmark)

Costa-Neto, Claudio M; Miyakawa, Ayumi A; Pesquero, João B

2002-01-01

and inositol phosphate turnover assays in COS-7 cells transiently transfected with the wild-type and mutant forms of the receptor. Mutant receptors bore modifications in the extracellular region: T88H, Y92H, G1961, G196W, and D278E. Compound L-162,313 displaced [125I]-Sar1,Leu8-AngII from the mutants G196I...... and G196W with IC50 values similar to that of the wild-type. The affinity was, however, slightly affected by the D278E mutation and more significantly by the T88H and Y92H mutations. In inositol phosphate turnover assays, the ability of L-162,313 to trigger the activation cascade was compared...... with that of angiotensin II. These assays showed that the G196W mutant reached a relative maximum activation exceeding that of the wild-type receptor; the efficacy was slightly reduced in the G1961 mutant and further reduced in the T88H, Y92H, and D278E mutants. Our data suggest that residues of the extracellular domain...

Mutations in the estrogen receptor alpha hormone binding domain promote stem cell phenotype through notch activation in breast cancer cell lines.

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Gelsomino, L; Panza, S; Giordano, C; Barone, I; Gu, G; Spina, E; Catalano, S; Fuqua, S; Andò, S

2018-04-24

The detection of recurrent mutations affecting the hormone binding domain (HBD) of estrogen receptor alpha (ERα/ESR1) in endocrine therapy-resistant and metastatic breast cancers has prompted interest in functional characterization of these genetic alterations. Here, we explored the role of HBD-ESR1 mutations in influencing the behavior of breast cancer stem cells (BCSCs), using various BC cell lines stably expressing wild-type or mutant (Y537 N, Y537S, D538G) ERα. Compared to WT-ERα clones, mutant cells showed increased CD44 + /CD24 - ratio, mRNA levels of stemness genes, Mammosphere Forming Efficiency (MFE), Self-Renewal and migratory capabilities. Mutant clones exhibited high expression of NOTCH receptors/ligands/target genes and blockade of NOTCH signaling reduced MFE and migratory potential. Mutant BCSC activity was dependent on ERα phosphorylation at serine 118, since its inhibition decreased MFE and NOTCH4 activation only in mutant cells. Collectively, we demonstrate that the expression of HBD-ESR1 mutations may drive BC cells to acquire stem cell traits through ER/NOTCH4 interplay. We propose the early detection of HBD-ESR1 mutations as a challenge in precision medicine strategy, suggesting the development of tailored-approaches (i.e. NOTCH inhibitors) to prevent disease development and metastatic spread in BC mutant-positive patients. Copyright © 2018 Elsevier B.V. All rights reserved.

RECEPTOR POTENTIAL AND LIGHT-INDUCED MITOCHONDRIAL ACTIVATION IN BLOWFLY PHOTORECEPTOR MUTANTS

NARCIS (Netherlands)

MOJET, MH; TINBERGEN, J; STAVENGA, DG

1991-01-01

1. Simultaneous measurements of the receptor potential and the light-induced mitochondrial activation were performed in white-eyed blowflies Calliphora vicina, mutant chalky, and Lucilia cuprina, mutants w(F) and w'nss. The intensity dependence and the temporal dynamics were investigated. 2. The

Bacteriophage-resistant mutants in Yersinia pestis: identification of phage receptors and attenuation for mice.

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Andrey A Filippov

Full Text Available BACKGROUND: Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD₅₀ and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. CONCLUSIONS/SIGNIFICANCE: We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis.

Thyroid hormone and retinoic acid nuclear receptors: specific ligand-activated transcription factors

International Nuclear Information System (INIS)

Brtko, J.

1998-01-01

Transcriptional regulation by both the thyroid hormone and the vitamin A-derived 'retinoid hormones' is a critical component in controlling many aspects of higher vertebrate development and metabolism. Their functions are mediated by nuclear receptors, which comprise a large super-family of ligand-inducible transcription factors. Both the thyroid hormone and the retinoids are involved in a complex arrangement of physiological and development responses in many tissues of higher vertebrates. The functions of 3,5,3'-triiodothyronine (T 3 ), the thyromimetically active metabolite of thyroxine as well as all-trans retinoic acid, the biologically active vitamin A metabolite are mediated by nuclear receptor proteins that are members of the steroid/thyroid/retinoid hormone receptor family. The functions of all members of the receptor super family are discussed. (authors)

Anti-idiotypic antibody: A new strategy for the development of a growth hormone receptor antagonist.

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Lan, Hainan; Zheng, Xin; Khan, Muhammad Akram; Li, Steven

2015-11-01

In general, traditional growth hormone receptor antagonist can be divided into two major classes: growth hormone (GH) analogues and anti-growth hormone receptor (GHR) antibodies. Herein, we tried to explore a new class of growth hormone receptor (GHR) antagonist that may have potential advantages over the traditional antagonists. For this, we developed a monoclonal anti-idiotypic antibody growth hormone, termed CG-86. A series of experiments were conducted to characterize and evaluate this antibody, and the results from a competitive receptor-binding assay, Enzyme Linked Immunosorbent Assays (ELISA) and epitope mapping demonstrate that CG-86 behaved as a typical Ab2β. Next, we examined its antagonistic activity using in vitro cell models, and the results showed that CG-86 could effectively inhibit growth hormone receptor-mediated signalling and effectively inhibit growth hormone-induced Ba/F3-GHR638 proliferation. In summary, these studies show that an anti-idiotypic antibody (CG-86) has promise as a novel growth hormone receptor antagonist. Furthermore, the current findings also suggest that anti-idiotypic antibody may represent a novel strategy to produce a new class of growth hormone receptor antagonist, and this strategy may be applied with other cytokines or growth factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

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Schaefer, G B; Rosenbloom, A L; Guevara-Aguirre, J; Campbell, E A; Ullrich, F; Patil, K; Frias, J L

1994-01-01

Facial morphometry using computerised image analysis was performed on patients with growth hormone receptor deficiency (Laron syndrome) from an inbred population of southern Ecuador. Morphometrics were compared for 49 patients, 70 unaffected relatives, and 14 unrelated persons. Patients with growth hormone receptor deficiency showed significant decreases in measures of vertical facial growth as compared to unaffected relatives and unrelated persons with short stature from other causes. This report validates and quantifies the clinical impression of foreshortened facies in growth hormone receptor deficiency. Images PMID:7815422

EP3 receptors inhibit antidiuretic-hormone-dependent sodium transport across frog skin epithelium

DEFF Research Database (Denmark)

Rytved, Klaus A.; Nielsen, Robert

1999-01-01

Antidiuretic hormone; tight epithelium; prostaglandin receptors; sulprostone; misoprostol; cAMP; cellular Ca2+......Antidiuretic hormone; tight epithelium; prostaglandin receptors; sulprostone; misoprostol; cAMP; cellular Ca2+...

Hormone action. Part I. Peptide hormones

International Nuclear Information System (INIS)

Birnbaumer, L.; O'Malley, B.W.

1985-01-01

The major sections of this book on the hormonal action of peptide hormones cover receptor assays, identification of receptor proteins, methods for identification of internalized hormones and hormone receptors, preparation of hormonally responsive cells and cell hybrids, purification of membrane receptors and related techniques, assays of hormonal effects and related functions, and antibodies in hormone action

Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

International Nuclear Information System (INIS)

Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

1987-01-01

Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

Steroid hormone receptors: long- and short-term integrators of the internal milieu and the external environment.

Science.gov (United States)

Blaustein, J D

2012-07-01

Many of the influences of estrogens and progestins on the brain and behavior are mediated by estrogen receptors and progestin receptors, acting as transcriptional regulators. The homologous and heterologous regulation of the concentrations of these receptors by cognate hormones is well established. However, although they were discovered and characterized based on their binding to cognate hormone and their role in transcriptional regulation, steroid hormone receptors have a more complex role and serve many more functions than originally suspected. First, besides being regulated by steroid hormones, the intracellular concentrations of brain steroid hormone receptors are regulated by neurotransmitters, a pathway by which stimuli from the environment, including from conspecific animals, can modulate the concentration of particular steroid hormone receptors in subsets of cells. Further, besides being activated by cognate steroid hormones, the receptors can be activated by a variety of neurotransmitters and phosphorylation pathways, providing a route through which environmental stimulation can activate steroid-receptor-dependent functions in specific cells. In addition, the transcription factor, estrogen receptor-α, produced from the estrogen receptor-α gene, can be modified to be targeted to membranes, where it can signal via kinase pathways. Finally, developmental experiences, such as particular stressors during the pubertal period, can permanently remodel the brain's response to ovarian hormones, most likely by long-term changes in regulation of the receptors mediating those responses. In addition to their function in responding to cognate ligand, it is now more appropriate to think of steroid hormone receptors as integrators of a wide variety of signaling pathways. © Georg Thieme Verlag KG Stuttgart · New York.

Structural and functional plasticity of the luteinizing hormone/choriogonadotrophin receptor.

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Troppmann, Britta; Kleinau, Gunnar; Krause, Gerd; Gromoll, Jörg

2013-01-01

BACKGROUND In recent years it became evident that several types of the luteinizing hormone/choriogonadotrophin receptor (LHCGR) exist. In addition to the classical receptor type known in rodents, an LHCGR type containing an additional exon is present in primates and humans. This specific exon 6A introduces a hitherto unknown regulatory pathway of the LHCGR at the transcriptional level which can lead to the expression of an alternative protein covering the extracellular part only. Furthermore, an LHCGR type lacking exon 10 at the mRNA and protein levels has been described in the New World primate lineage, giving rise to an additional receptor type in which amino acids of the extracellular hinge region connecting the leucine-rich repeat domain and transmembrane domain are missing. METHODS Topic-related information was retrieved by systematic searches using Medline/PubMed. Structural homology models were retrieved from a glycoprotein hormone receptors web application and from recent publications. RESULTS In a novel approach, we combine functional aspects with three-dimensional properties of the LHCGR and the different receptor types to deduce causative relationships between these two parameters. On this basis, the physiological impact and patho-physiological consequences of the different LHCGR types are inferred. CONCLUSIONS The complex system of different LHCGR types and two corresponding hormones (LH and CG) represents a major challenge for future studies on selective hormone binding, signal transduction and receptor regulation. The presence of these naturally occurring LHCGR types requires re-examining of our present view on receptor function, experimental set-ups and data interpretation, but also offers new clinical approaches to interfere with LH/CG action in humans.

Pentadecapeptide BPC 157 Enhances the Growth Hormone Receptor Expression in Tendon Fibroblasts

Directory of Open Access Journals (Sweden)

Chung-Hsun Chang

2014-11-01

Full Text Available BPC 157, a pentadecapeptide derived from human gastric juice, has been demonstrated to promote the healing of different tissues, including skin, muscle, bone, ligament and tendon in many animal studies. However, the underlying mechanism has not been fully clarified. The present study aimed to explore the effect of BPC 157 on tendon fibroblasts isolated from Achilles tendon of male Sprague-Dawley rat. From the result of cDNA microarray analysis, growth hormone receptor was revealed as one of the most abundantly up-regulated genes in tendon fibroblasts by BPC 157. BPC 157 dose- and time-dependently increased the expression of growth hormone receptor in tendon fibroblasts at both the mRNA and protein levels as measured by RT/real-time PCR and Western blot, respectively. The addition of growth hormone to BPC 157-treated tendon fibroblasts dose- and time-dependently increased the cell proliferation as determined by MTT assay and PCNA expression by RT/real-time PCR. Janus kinase 2, the downstream signal pathway of growth hormone receptor, was activated time-dependently by stimulating the BPC 157-treated tendon fibroblasts with growth hormone. In conclusion, the BPC 157-induced increase of growth hormone receptor in tendon fibroblasts may potentiate the proliferation-promoting effect of growth hormone and contribute to the healing of tendon.

Hormone receptor densities in relation to 10B neutron capture therapy

International Nuclear Information System (INIS)

Hechter, O.; Schwartz, I.L.

1982-01-01

This presentation is a theoretical discussion of the possibility that appropriate steroid-carborane derivatives might be used to selectively deliver boron-10 ( 10 B) to tumor cells with sex-hormone receptors in sufficient concentration for effective neutron capture theory (NCT) of hormone-dependent mammary and prostatic cancer. The results indicate the concentrations of androgen receptors (AR) and progesterone receptors (PR) in malignant prostatic cells or of estrogen receptors (ER) in malignant mammary cells are two low to achieve nuclear 10 B concentrations of 1 + g per g of tumor by using a steroid ligand coupled to a single carborane cage

Sex Hormones and Their Receptors Regulate Liver Energy Homeostasis

Directory of Open Access Journals (Sweden)

Minqian Shen

2015-01-01

Full Text Available The liver is one of the most essential organs involved in the regulation of energy homeostasis. Hepatic steatosis, a major manifestation of metabolic syndrome, is associated with imbalance between lipid formation and breakdown, glucose production and catabolism, and cholesterol synthesis and secretion. Epidemiological studies show sex difference in the prevalence in fatty liver disease and suggest that sex hormones may play vital roles in regulating hepatic steatosis. In this review, we summarize current literature and discuss the role of estrogens and androgens and the mechanisms through which estrogen receptors and androgen receptors regulate lipid and glucose metabolism in the liver. In females, estradiol regulates liver metabolism via estrogen receptors by decreasing lipogenesis, gluconeogenesis, and fatty acid uptake, while enhancing lipolysis, cholesterol secretion, and glucose catabolism. In males, testosterone works via androgen receptors to increase insulin receptor expression and glycogen synthesis, decrease glucose uptake and lipogenesis, and promote cholesterol storage in the liver. These recent integrated concepts suggest that sex hormone receptors could be potential promising targets for the prevention of hepatic steatosis.

Evolutionary aspects of growth hormones and prolactins and their receptors

International Nuclear Information System (INIS)

Tarpey, J.F.

1986-01-01

The interactions of GH's, PRL's and PL's with receptors for GH and PRL were examined from a comparative and evolutionary viewpoint. The binding of 125 I-bGH to membrane preparations from liver of representatives of the major classes of non-mammalian vertebrates was also studied. Only hepatic membranes from sturgeon and Gillichthys had significant bGH binding and were further characterized and compared with male rabbit liver membranes in terms of time, temperature, pH, and membrane concentration to optimize binding conditions. The binding of several members of the GH, PRL, PL family of hormones to GH receptors from liver of sturgeon, Gillichthys, rabbit, mouse and rat was investigated. in terms of hormonal specificity, the mammalian receptors and the sturgeon binding sites were similar, while Gillichthys receptors had a different pattern of hormonal specificity. The binding of 125 I-oPRL to renal membranes of the turtle, Pseudemys scripta elegans, was characterized and compared to PRL binding sites of kidney membranes of the bullfrog, Rana catesbeiana, and the tiger salamander, Ambystoma tigrinum

A mutation in the receptor Methoprene-tolerant alters juvenile hormone response in insects and crustaceans.

Science.gov (United States)

Miyakawa, Hitoshi; Toyota, Kenji; Hirakawa, Ikumi; Ogino, Yukiko; Miyagawa, Shinichi; Oda, Shigeto; Tatarazako, Norihisa; Miura, Toru; Colbourne, John K; Iguchi, Taisen

2013-01-01

Juvenile hormone is an essential regulator of major developmental and life history events in arthropods. Most of the insects use juvenile hormone III as the innate juvenile hormone ligand. By contrast, crustaceans use methyl farnesoate. Despite this difference that is tied to their deep evolutionary divergence, the process of this ligand transition is unknown. Here we show that a single amino-acid substitution in the receptor Methoprene-tolerant has an important role during evolution of the arthropod juvenile hormone pathway. Microcrustacea Daphnia pulex and D. magna share a juvenile hormone signal transduction pathway with insects, involving Methoprene-tolerant and steroid receptor coactivator proteins that form a heterodimer in response to various juvenoids. Juvenile hormone-binding pockets of the orthologous genes differ by only two amino acids, yet a single substitution within Daphnia Met enhances the receptor's responsiveness to juvenile hormone III. These results indicate that this mutation within an ancestral insect lineage contributed to the evolution of a juvenile hormone III receptor system.

Transcriptional activation by the thyroid hormone receptor through ligand-dependent receptor recruitment and chromatin remodelling

DEFF Research Database (Denmark)

Grøntved, Lars; Waterfall, Joshua J; Kim, Dong Wook

2015-01-01

A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co...

Precocious metamorphosis in the juvenile hormone-deficient mutant of the silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Takaaki Daimon

Full Text Available Insect molting and metamorphosis are intricately governed by two hormones, ecdysteroids and juvenile hormones (JHs. JHs prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it attains the proper size for metamorphosis. In the silkworm, Bombyx mori, several "moltinism" mutations have been identified that exhibit variations in the number of larval molts; however, none of them have been characterized molecularly. Here we report the identification and characterization of the gene responsible for the dimolting (mod mutant that undergoes precocious metamorphosis with fewer larval-larval molts. We show that the mod mutation results in complete loss of JHs in the larval hemolymph and that the mutant phenotype can be rescued by topical application of a JH analog. We performed positional cloning of mod and found a null mutation in the cytochrome P450 gene CYP15C1 in the mod allele. We also demonstrated that CYP15C1 is specifically expressed in the corpus allatum, an endocrine organ that synthesizes and secretes JHs. Furthermore, a biochemical experiment showed that CYP15C1 epoxidizes farnesoic acid to JH acid in a highly stereospecific manner. Precocious metamorphosis of mod larvae was rescued when the wild-type allele of CYP15C1 was expressed in transgenic mod larvae using the GAL4/UAS system. Our data therefore reveal that CYP15C1 is the gene responsible for the mod mutation and is essential for JH biosynthesis. Remarkably, precocious larval-pupal transition in mod larvae does not occur in the first or second instar, suggesting that authentic epoxidized JHs are not essential in very young larvae of B. mori. Our identification of a JH-deficient mutant in this model insect will lead to a greater understanding of the molecular basis of the hormonal control of development and metamorphosis.

Growth hormone-releasing hormone as an agonist of the ghrelin receptor GHS-R1a.

Science.gov (United States)

Casanueva, Felipe F; Camiña, Jesus P; Carreira, Marcos C; Pazos, Yolanda; Varga, Jozsef L; Schally, Andrew V

2008-12-23

Ghrelin synergizes with growth hormone-releasing hormone (GHRH) to potentiate growth hormone (GH) response through a mechanism not yet fully characterized. This study was conducted to analyze the role of GHRH as a potential ligand of the ghrelin receptor, GHS-R1a. The results show that hGHRH(1-29)NH(2) (GHRH) induces a dose-dependent calcium mobilization in HEK 293 cells stably transfected with GHS-R1a an effect not observed in wild-type HEK 293 cells. This calcium rise is also observed using the GHRH receptor agonists JI-34 and JI-36. Radioligand binding and cross-linking studies revealed that calcium response to GHRH is mediated by the ghrelin receptor GHS-R1a. GHRH activates the signaling route of inositol phosphate and potentiates the maximal response to ghrelin measured in inositol phosphate turnover. The presence of GHRH increases the binding capacity of (125)I-ghrelin in a dose dependent-fashion showing a positive binding cooperativity. In addition, confocal microscopy in CHO cells transfected with GHS-R1a tagged with enhanced green fluorescent protein shows that GHRH activates the GHS-R1a endocytosis. Furthermore, the selective GHRH-R antagonists, JV-1-42 and JMR-132, act also as antagonists of the ghrelin receptor GHS-R1a. Our findings suggest that GHRH interacts with ghrelin receptor GHS-R1a, and, in consequence, modifies the ghrelin-associated intracellular signaling pathway. This interaction may represent a form of regulation, which could play a putative role in the physiology of GH regulation and appetite control.

Recurrent nonsense mutations in the growth hormone receptor from patients with Laron dwarfism.

Science.gov (United States)

Amselem, S; Sobrier, M L; Duquesnoy, P; Rappaport, R; Postel-Vinay, M C; Gourmelen, M; Dallapiccola, B; Goossens, M

1991-01-01

In addition to its classical effects on growth, growth hormone (GH) has been shown to have a number of other actions, all of which are initiated by an interaction with specific high affinity receptors present in a variety of tissues. Purification of a rabbit liver protein via its ability to bind GH has allowed the isolation of a cDNA encoding a putative human growth hormone receptor that belongs to a new class of transmembrane receptors. We have previously shown that this putative growth hormone receptor gene is genetically linked to Laron dwarfism, a rare autosomal recessive syndrome caused by target resistance to GH. Nevertheless, the inability to express the corresponding full-length coding sequence and the lack of a test for growth-promoting function have hampered a direct confirmation of its role in growth. We have now identified three nonsense mutations within this growth hormone receptor gene, lying at positions corresponding to the amino terminal extremity and causing a truncation of the molecule, thereby deleting a large portion of both the GH binding domain and the full transmembrane and intracellular domains. Three independent patients with Laron dwarfism born of consanguineous parents were homozygous for these defects. Two defects were identical and consisted of a CG to TG transition. Not only do these results confirm the growth-promoting activity of this receptor but they also suggest that CpG doublets may represent hot spots for mutations in the growth hormone receptor gene that are responsible for hereditary dwarfism. Images PMID:1999489

Variations in steroid hormone receptor content throughout age and menopausal periods, and menstrual cycle in breast cancer patients

International Nuclear Information System (INIS)

Nikolic-Vukosavljevic, D.; Vasiljevic, N.; Brankovic-Magic, M.; Polic, D.

1996-01-01

Variations in steroid hormone receptor contents throughout age and menopausal periods define three breast carcinoma groups: younger pre-menopausal carcinomas (aged up to 45), middle-aged carcinomas (aged up to 45), middle-aged carcinomas (pre-, peri-, and postmenopausal aged 45-59) and older postmenopausal carcinomas (aged over 59). Age-related steroid hormone receptor contents within pre-menopausal and postmenopausal carcinoma groups are characterized by the important increase of both receptor contents, while menopausal-related steroid hormone receptor contents within middle-aged carcinoma group (aged 45-59) are characterized by the important decrease of progesterone receptor content and estrogen receptor functionality. No variations in steroid hormone receptor contents throughout menstrual cycle within the follicular and the luteal phases were obtained. The important cycle within the follicular and the luteal phases were obtained. The important decrease of estrogen receptor content in the mid-cycle phase versus the peri-menstrual phase was found. Variations in steroid hormone receptor contents throughout age and menopausal periods, as well as throughout menstrual cycle could nod be associated with variations in the blood steroid hormone concentrations. However, important association between steroid hormone receptor contents and the blood steroid hormone concentrations was found within the luteal phase carcinoma group and within older postmenopausal carcinoma group. It is interesting that within carcinoma group with the highest concentration of progesterone, progesterone receptor content increases with an increase of the ration of estradiol and progesterone blood concentrations, while within carcinoma group with the lowest steroid hormone concentration and the highest content of estrogen receptor content, estrogen receptor content decreases with an increase of either the blood estradiol concentration or the ratio of the blood estradiol and progesterone blood

Allosteric activation of the follicle-stimulating hormone (FSH) receptor by selective, nonpeptide agonists.

Science.gov (United States)

Yanofsky, Stephen D; Shen, Emily S; Holden, Frank; Whitehorn, Erik; Aguilar, Barbara; Tate, Emily; Holmes, Christopher P; Scheuerman, Randall; MacLean, Derek; Wu, May M; Frail, Donald E; López, Francisco J; Winneker, Richard; Arey, Brian J; Barrett, Ronald W

2006-05-12

The pituitary glycoprotein hormones, luteinizing hormone and follicle-stimulating hormone (FSH), act through their cognate receptors to initiate a series of coordinated physiological events that results in germ cell maturation. Given the importance of FSH in regulating folliculogenesis and fertility, the development of FSH mimetics has been sought to treat infertility. Currently, purified and recombinant human FSH are the only FSH receptor (FSH-R) agonists available for infertility treatment. By screening unbiased combinatorial chemistry libraries, using a cAMP-responsive luciferase reporter assay, we discovered thiazolidinone agonists (EC50's = 20 microm) of the human FSH-R. Subsequent analog library screening and parallel synthesis optimization resulted in the identification of a potent agonist (EC50 = 2 nm) with full efficacy compared with FSH that was FSH-R-selective and -dependent. The compound mediated progesterone production in Y1 cells transfected with the human FSH-R (EC50 = 980 nm) and estradiol production from primary rat ovarian granulosa cells (EC50 = 10.5 nm). This and related compounds did not compete with FSH for binding to the FSH-R. Use of human FSH/thyroid-stimulating hormone (TSH) receptor chimeras suggested a novel mechanism for receptor activation through a binding site independent of the natural hormone binding site. This study is the first report of a high affinity small molecule agonist that activates a glycoprotein hormone receptor through an allosteric mechanism. The small molecule FSH receptor agonists described here could lead to an oral alternative to the current parenteral FSH treatments used clinically to induce ovarian stimulation for both in vivo and in vitro fertilization therapy.

Differential binding of prohibitin-2 to estrogen receptor α and to drug-resistant ERα mutants

Energy Technology Data Exchange (ETDEWEB)

Chigira, Takeru, E-mail: 8120661875@mail.ecc.u-tokyo.ac.jp [Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Nagatoishi, Satoru, E-mail: nagatoishi@bioeng.t.u-tokyo.ac.jp [Department of Bioengineering, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan); Tsumoto, Kouhei, E-mail: tsumoto@bioeng.t.u-tokyo.ac.jp [Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Department of Bioengineering, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan)

2015-08-07

Endocrine resistance is one of the most challenging problems in estrogen receptor alpha (ERα)-positive breast cancer. The transcriptional activity of ERα is controlled by several coregulators, including prohibitin-2 (PHB2). Because of its ability to repress the transcriptional activity of activated ERα, PHB2 is a promising antiproliferative agent. In this study, were analyzed the interaction of PHB2 with ERα and three mutants (Y537S, D538G, and E380Q) that are frequently associated with a lack of sensitivity to hormonal treatments, to help advance novel drug discovery. PHB2 bound to ERα wild-type (WT), Y537S, and D538G, but did not bind to E380Q. The binding thermodynamics of Y537S and D538G to PHB2 were favorably altered entropically compared with those of WT to PHB2. Our results show that PHB2 binds to the ligand binding domain of ERα with a conformational change in the helix 12 of ERα. - Highlights: • Molten globule-likeness of an ERα repressor Prohibitin-2 (PHB2) is identified. • The thermodynamics is validated for the interaction between ERα and PHB2. • PHB2 binds to Y537S and D538G mutants of ERα commonly found in breast cancer. • ERα WT and mutants showed different thermodynamic parameters in the binding to PHB2. • ERα binds to PHB2 with conformational change involving packing of helix 12.

Internalization and recycling of receptor-bound gonadotropin-releasing hormone agonist in pituitary gonadotropes

International Nuclear Information System (INIS)

Schvartz, I.; Hazum, E.

1987-01-01

The fate of cell surface gonadotropin-releasing hormone (GnRH) receptors on pituitary cells was studied utilizing lysosomotropic agents and monensin. Labeling of pituitary cells with a photoreactive GnRH derivative, [azidobenzoyl-D-Lys6]GnRH, revealed a specific band of Mr = 60,000. When photoaffinity-labeled cells were exposed to trypsin immediately after completion of the binding, the radioactivity incorporated into the Mr = 60,000 band decreased, with a concomitant appearance of a proteolytic fragment (Mr = 45,000). This fragment reflects cell surface receptors. Following GnRH binding, the hormone-receptor complexes underwent internalization, partial degradation, and recycling. The process of hormone-receptor complex degradation was substantially prevented by lysosomotropic agents, such as chloroquine and methylamine, or the proton ionophore, monensin. Chloroquine and monensin, however, did not affect receptor recycling, since the tryptic fragment of Mr = 45,000 was evident after treatment with these agents. This suggests that recycling of GnRH receptors in gonadotropes occurs whether or not the internal environment is acidic. Based on these findings, we propose a model describing the intracellular pathway of GnRH receptors

Ultradian hormone stimulation induces glucocorticoid receptor-mediated pulses of gene transcription.

Science.gov (United States)

Stavreva, Diana A; Wiench, Malgorzata; John, Sam; Conway-Campbell, Becky L; McKenna, Mervyn A; Pooley, John R; Johnson, Thomas A; Voss, Ty C; Lightman, Stafford L; Hager, Gordon L

2009-09-01

Studies on glucocorticoid receptor (GR) action typically assess gene responses by long-term stimulation with synthetic hormones. As corticosteroids are released from adrenal glands in a circadian and high-frequency (ultradian) mode, such treatments may not provide an accurate assessment of physiological hormone action. Here we demonstrate that ultradian hormone stimulation induces cyclic GR-mediated transcriptional regulation, or gene pulsing, both in cultured cells and in animal models. Equilibrium receptor-occupancy of regulatory elements precisely tracks the ligand pulses. Nascent RNA transcripts from GR-regulated genes are released in distinct quanta, demonstrating a profound difference between the transcriptional programs induced by ultradian and constant stimulation. Gene pulsing is driven by rapid GR exchange with response elements and by GR recycling through the chaperone machinery, which promotes GR activation and reactivation in response to the ultradian hormone release, thus coupling promoter activity to the naturally occurring fluctuations in hormone levels. The GR signalling pathway has been optimized for a prompt and timely response to fluctuations in hormone levels, indicating that biologically accurate regulation of gene targets by GR requires an ultradian mode of hormone stimulation.

Introduction of exogenous growth hormone receptors augments growth hormone-responsive insulin biosynthesis in rat insulinoma cells

DEFF Research Database (Denmark)

Billestrup, N; Møldrup, A; Serup, P

1990-01-01

The stimulation of insulin biosynthesis in the pancreatic insulinoma cell line RIN5-AH by growth hormone (GH) is initiated by GH binding to specific receptors. To determine whether the recently cloned rat hepatic GH receptor is able to mediate the insulinotropic effect of GH, we have transfected ...

Dietary modification of metabolic pathways via nuclear hormone receptors.

Science.gov (United States)

Caiozzi, Gianella; Wong, Brian S; Ricketts, Marie-Louise

2012-10-01

Nuclear hormone receptors (NHRs), as ligand-dependent transcription factors, have emerged as important mediators in the control of whole body metabolism. Because of the promiscuous nature of several members of this superfamily that have been found to bind ligand with lower affinity than the classical steroid NHRs, they consequently display a broader ligand selectivity. This promiscuous nature has facilitated various bioactive dietary components being able to act as agonist ligands for certain members of the NHR superfamily. By binding to these NHRs, bioactive dietary components are able to mediate changes in various metabolic pathways, including, glucose, cholesterol and triglyceride homeostasis among others. This review will provide a general overview of the nuclear hormone receptors that have been shown to be activated by dietary components. The physiological consequences of such receptor activation by these dietary components will then be discussed in more detail. Copyright © 2012 John Wiley & Sons, Ltd.

(−) Arctigenin and (+) Pinoresinol Are Antagonists of the Human Thyroid Hormone Receptor β

Science.gov (United States)

2015-01-01

Lignans are important biologically active dietary polyphenolic compounds. Consumption of foods that are rich in lignans is associated with positive health effects. Using modeling tools to probe the ligand-binding pockets of molecular receptors, we found that lignans have high docking affinity for the human thyroid hormone receptor β. Follow-up experimental results show that lignans (−) arctigenin and (+) pinoresinol are antagonists of the human thyroid hormone receptor β. The modeled complexes show key plausible interactions between the two ligands and important amino acid residues of the receptor. PMID:25383984

Identifying neuropeptide and protein hormone receptors in Drosophila melanogaster by exploiting genomic data

DEFF Research Database (Denmark)

Hauser, Frank; Williamson, Michael; Cazzamali, Giuseppe

2006-01-01

insect genome, that of the fruitfly Drosophila melanogaster, was sequenced in 2000, and about 200 GPCRs have been annnotated in this model insect. About 50 of these receptors were predicted to have neuropeptides or protein hormones as their ligands. Since 2000, the cDNAs of most of these candidate...... receptors have been cloned and for many receptors the endogenous ligand has been identified. In this review, we will give an update about the current knowledge of all Drosophila neuropeptide and protein hormone receptors, and discuss their phylogenetic relationships. Udgivelsesdato: 2006-Feb...

A single amino acid substitution in the exoplasmic domain of the human growth hormone (GH) receptor confers familial GH resistance (Laron syndrome) with positive GH-binding activity by abolishing receptor homodimerization.

Science.gov (United States)

Duquesnoy, P; Sobrier, M L; Duriez, B; Dastot, F; Buchanan, C R; Savage, M O; Preece, M A; Craescu, C T; Blouquit, Y; Goossens, M

1994-01-01

Growth hormone (GH) elicits a variety of biological activities mainly mediated by the GH receptor (GHR), a transmembrane protein that, based on in vitro studies, seemed to function as a homodimer. To test this hypothesis directly, we investigated patients displaying the classic features of Laron syndrome (familial GH resistance characterized by severe dwarfism and metabolic dysfunction), except for the presence of normal binding activity of the plasma GH-binding protein, a molecule that derives from the exoplasmic-coding domain of the GHR gene. In two unrelated families, the same GHR mutation was identified, resulting in the substitution of a highly conserved aspartate residue by histidine at position 152 (D152H) of the exoplasmic domain, within the postulated interface sequence involved in homodimerization. The recombinant mutated receptor protein was correctly expressed at the plasma membrane. It displayed subnormal GH-binding activity, a finding in agreement with the X-ray crystal structure data inferring this aspartate residue outside the GH-binding domain. However, mAb-based studies suggested the critical role of aspartate 152 in the proper folding of the interface area. We show that a recombinant soluble form of the mutant receptor is unable to dimerize, the D152H substitution also preventing the formation of heterodimers of wild-type and mutant molecules. These results provide in vivo evidence that monomeric receptors are inactive and that receptor dimerization is involved in the primary signalling of the GH-associated growth-promoting and metabolic actions. Images PMID:8137822

Status of sex steroid hormone receptors in large bowel cancer

NARCIS (Netherlands)

Meggouh, F.; Lointier, P.; Pezet, D.; Saez, S.

1991-01-01

To determine the potential role of sex steroid hormones in the development of colorectal tumors in humans, specific androgen (AR), estrogen (ER), and progesterone (PGR) receptors were investigated in normal mucosa (NM) and in tumor (T) paired biopsy specimens from 94 patients. Androgen receptors

Role of ELA region in auto-activation of mutant KIT receptor: a molecular dynamics simulation insight.

Science.gov (United States)

Purohit, Rituraj

2014-01-01

KIT receptor is the prime target in gastrointestinal stromal tumor (GISTs) therapy. Second generation inhibitor, Sunitinib, binds to an inactivated conformation of KIT receptor and stabilizes it in order to prevent tumor formation. Here, we investigated the dynamic behavior of wild type and mutant D816H KIT receptor, and emphasized the extended A-loop (EAL) region (805-850) by conducting molecular dynamics simulation (∼100 ns). We analyzed different properties such as root mean square cutoff or deviation, root mean square fluctuation, radius of gyration, solvent-accessible surface area, hydrogen bonding network analysis, and essential dynamics. Apart from this, clustering and cross-correlation matrix approach was used to explore the conformational space of the wild type and mutant EAL region of KIT receptor. Molecular dynamics analysis indicated that mutation (D816H) was able to alter intramolecular hydrogen bonding pattern and affected the structural flexibility of EAL region. Moreover, flexible secondary elements, specially, coil and turns were dominated in EAL region of mutant KIT receptor during simulation. This phenomenon increased the movement of EAL region which in turn helped in shifting the equilibrium towards the active kinase conformation. Our atomic investigation of mutant KIT receptor which emphasized on EAL region provided a better insight into the understanding of Sunitinib resistance mechanism of KIT receptor and would help to discover new therapeutics for KIT-based resistant tumor cells in GIST therapy.

Expansion of microsatellite in the thyroid hormone receptor-alpha1 gene linked to increased receptor expression and less aggressive thyroid cancer

DEFF Research Database (Denmark)

Onda, Masamitsu; Li, Daisy; Suzuki, Shinichi

2002-01-01

PURPOSE: The purpose of this study was to determine whether the length of the THRA1 microsatellite, which resides in a noncoding portion of the thyroid hormone receptor-alpha1 gene, affects receptor expression and is linked to clinicopathological parameters in thyroid cancer. EXPERIMENTAL DESIGN......: In 30 cases of surgically resected sporadic thyroid cancer, the length of the THRA1 microsatellite was determined by DNA sequence analysis, and expression of thyroid hormone receptor-alpha1 was assessed immunohistochemically in thin sections cut from tumor blocks. The length of THRA1 and expression...... of thyroid hormone receptor-alpha1 were also assessed in seven cancer cell lines. Regression analysis was used to gauge the correlation between the size of THRA1 and receptor expression. Multivariate analysis was used to test for links to the clinical parameters of gender, age, histology, stage, nodal...

Use of hormone receptors in scintigraphy of the ovaries

International Nuclear Information System (INIS)

Kairento, A.L.; Karonen, S.L.; Adlercreutz, H.

1981-01-01

Based on the mechanism of hormone receptors, luteinizing hormone (LH) labelled with 123-iodine was used as tracer in scintigraphy of rabbit ovaries. The ovaries were visualized in static pictures 6-15 min after injection except in the case where the rabbit was pre-injected with 10 μg of cold LH. 3.1% of the injected activity was found in the ovaries 14 h after injection. (orig.) [de

Hormonal receptors and vascular endothelial growth factor in juvenile nasopharyngeal angiofibroma: immunohistochemical and tissue microarray analysis.

Science.gov (United States)

Liu, Zhuofu; Wang, Jingjing; Wang, Huan; Wang, Dehui; Hu, Li; Liu, Quan; Sun, Xicai

2015-01-01

This work demonstrated that juvenile nasopharyngeal angiofibromas (JNAs) express high levels of hormone receptors and vascular endothelial growth factor (VEGF) compared with normal nasal mucosa. The interaction between hormone receptors and VEGF may be involved in the initiation and growth of JNA. JNA is a rare benign tumor that occurs almost exclusively in male adolescents. Although generally regarded as a hormone-dependent tumor, this has not been proven in previous studies. The aim of this study was to investigate the role of hormone receptors in JNA and the relationship with clinical characteristics. Standard immunohistochemical microarray analysis was performed on 70 JNA samples and 10 turbinate tissue samples. Specific antibodies for androgen receptor (AR), estrogen receptor-α (ER-α), estrogen receptor-β (ER-β), progesterone receptor (PR), and VEGF were examined, and the relationships of receptor expression with age, tumor stage, and bleeding were evaluated. RESULTS showed that JNA expressed ER-α (92.9%), ER-β (91.4%), AR (65.7%), PR (12.8%), and VEGF (95.7%) at different levels. High level of VEGF was linked to elevated ER-α and ER-β. There was no significant relationship between hormonal receptors and age at diagnosis, tumor stage or bleeding. However, overexpression of ER-α was found to be an indicator of poor prognosis (p = 0.031).

Adipokinetic hormones and their G protein-coupled receptors emerged in Lophotrochozoa

DEFF Research Database (Denmark)

Li, Shizhong; Hauser, Frank; Skadborg, Signe K.

2016-01-01

the neuropeptide systems used by proto- or deuterostomes. An exception, however, are members of the gonadotropin-releasing hormone (GnRH) receptor superfamily, which occur in both evolutionary lineages, where GnRHs are the ligands in Deuterostomia and GnRH-like peptides, adipokinetic hormone (AKH), corazonin...

Ligand-independent Thrombopoietin Mutant Receptor Requires Cell Surface Localization for Endogenous Activity*

OpenAIRE

Marty, Caroline; Chaligné, Ronan; Lacout, Catherine; Constantinescu, Stefan N.; Vainchenker, William; Villeval, Jean-Luc

2009-01-01

The activating W515L mutation in the thrombopoietin receptor (MPL) has been identified in primary myelofibrosis and essential thrombocythemia. MPL belongs to a subset of the cytokine receptor superfamily that requires the JAK2 kinase for signaling. We examined whether the ligand-independent MPLW515L mutant could signal intracellularly. Addition of the endoplasmic reticulum (ER) retention KDEL sequence to the receptor C terminus efficiently locked MPLW515L within its na...

A transcriptionally active estrogen receptor mutant is a novel type of dominant negative inhibitor of estrogen action.

Science.gov (United States)

McInerney, E M; Ince, B A; Shapiro, D J; Katzenellenbogen, B S

1996-12-01

We have characterized a human estrogen receptor (ER) mutant, V364E, which has a single amino acid substitution in its hormone-binding domain. This ER mutant is fully active or even superactive at saturating levels of estradiol (10(-8) M E2) yet has the capacity to act as a strong dominant negative inhibitor of the wild type ER. In transient transfection assays using ER-negative Chinese hamster ovary (CHO) cells and two different estrogen response element (ERE)-containing promoter reporter genes, V364E treated with 10(-8) M E2 exhibited approximately 250% and 100% of the activity of the wild type ER with these two promoter contexts, respectively. Despite the high activity of V364E when present alone in cells, coexpression of both V364E and wild type ER causes a significant decrease in overall ER-mediated transcriptional activity. On the TATA promoter, where V364E was more inhibitory, estrogen-stimulated activity was reduced by approximately 50% at a 1:1 ratio of mutant to wild type ER expression vector, and at a 10:1 ratio, 75% of ER activity was inhibited. V364E was expressed at lower levels than wild type ER and has a approximately 40-fold lower affinity for E2 compared with wild type ER. In promoter interference assays, V364E exhibited a strict dependence upon E2 for binding to an ERE. Surprisingly, even when V364E was unable to bind to ERE DNA (i.e. either at low E2 concentration or by mutation of its DNA-binding domain), this mutant retained full dominant negative activity. This highly active ER mutant is, thus, able to repress ER-mediated transcription when the mutant and wild type ER are present together in cells, even without DNA binding. Since competition for ERE binding and the formation of inactive heterodimers cannot fully account for the dominant negative activity of V364E, it is probable that altered interactions with proteins important in ER-mediated transcription play a key role in the repression of transcription by V364E. The properties and probable

The ABA receptors -- we report you decide.

Science.gov (United States)

McCourt, Peter; Creelman, Robert

2008-10-01

The plant hormone abscisic acid (ABA) has been implicated in a variety of physiological responses ranging from seed dormancy to stomatal conductance. Recently, three groups have reported the molecular identification of three disparate ABA receptors. Unlike the identification of other hormone receptors, in these three cases high affinity binding to ABA rather than the isolation of ABA insensitive mutants led to these receptor genes. Interestingly, two of the receptors encode genes involved in floral timing and chlorophyll biosynthesis, which are not considered traditional ABA responses. And the third receptor has been clouded in issues of its molecular identity. To clearly determine the roles of these genes in ABA perception it will require placing of these ABA-binding proteins into the rich ABA physiological context that has built up over the years.

Expression profile and prognostic role of sex hormone receptors in gastric cancer

International Nuclear Information System (INIS)

Gan, Lu; He, Jian; Zhang, Xia; Zhang, Yong-Jie; Yu, Guan-Zhen; Chen, Ying; Pan, Jun; Wang, Jie-Jun; Wang, Xi

2012-01-01

Increasing interest has been devoted to the expression and possible role of sex hormone receptors in gastric cancer, but most of these findings are controversial. In the present study, the expression profile of sex hormone receptors in gastric cancer and their clinicopathological and prognostic value were determined in a large Chinese cohort. The mRNA and protein expression of estrogen receptor alpha (ERα), estrogen receptor beta (ERβ), progesterone receptor (PR), and androgen receptor (AR) in primary gastric tumors and corresponding adjacent normal tissues from 60 and 866 Chinese gastric cancer patients was detected by real-time quantitative PCR and immunohistochemistry method, respectively. The expression profile of the four receptors was compared and their associations with clinicopathological characteristics were assessed by using Chi-square test. The prognostic value of the four receptors in gastric cancer was evaluated by using univariate and multivariate Cox regression analysis. The presence of ERα, ERβ, PR, and AR in both gastric tumors and normal tissues was confirmed but their expression levels were extremely low except for the predominance of ERβ. The four receptors were expressed independently and showed a decreased expression pattern in gastric tumors compared to adjacent normal tissues. The positive expression of the four receptors all correlated with high tumor grade and intestinal type, and ERα and AR were also associated with early TNM stage and thereby a favorable outcome. However, ERα and AR were not independent prognostic factors for gastric cancer when multivariate survival analysis was performed. Our findings indicate that the sex hormone receptors may be partly involved in gastric carcinogenesis but their clinicopathological and prognostic significance in gastric cancer appears to be limited

A common polymorphism of the growth hormone receptor is associated with increased responsiveness to growth hormone.

Science.gov (United States)

Dos Santos, Christine; Essioux, Laurent; Teinturier, Cécile; Tauber, Maïté; Goffin, Vincent; Bougnères, Pierre

2004-07-01

Growth hormone is used to increase height in short children who are not deficient in growth hormone, but its efficacy varies largely across individuals. The genetic factors responsible for this variation are entirely unknown. In two cohorts of short children treated with growth hormone, we found that an isoform of the growth hormone receptor gene that lacks exon 3 (d3-GHR) was associated with 1.7 to 2 times more growth acceleration induced by growth hormone than the full-length isoform (P < 0.0001). In transfection experiments, the transduction of growth hormone signaling through d3-GHR homo- or heterodimers was approximately 30% higher than through full-length GHR homodimers (P < 0.0001). One-half of Europeans are hetero- or homozygous with respect to the allele encoding the d3-GHR isoform, which is dominant over the full-length isoform. These observations suggest that the polymorphism in exon 3 of GHR is important in growth hormone pharmacogenetics.

Sex Hormones and Cardiometabolic Health: Role of Estrogen and Estrogen Receptors.

Science.gov (United States)

Clegg, Deborah; Hevener, Andrea L; Moreau, Kerrie L; Morselli, Eugenia; Criollo, Alfredo; Van Pelt, Rachael E; Vieira-Potter, Victoria J

2017-05-01

With increased life expectancy, women will spend over three decades of life postmenopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions. Copyright © 2017 Endocrine Society.

Novel growth hormone receptor gene mutation in a patient with Laron syndrome.

Science.gov (United States)

Arman, Ahmet; Yüksel, Bilgin; Coker, Ajda; Sarioz, Ozlem; Temiz, Fatih; Topaloglu, Ali Kemal

2010-04-01

Growth Hormone (GH) is a 22 kDa protein that has effects on growth and glucose and fat metabolisms. These effects are initiated by binding of growth hormone (GH) to growth hormone receptors (GHR) expressed in target cells. Mutations or deletions in the growth hormone receptor cause an autosomal disorder called Laron-type dwarfism (LS) characterized by high circulating levels of serum GH and low levels of insulin like growth factor-1 (IGF-1). We analyzed the GHR gene for genetic defect in seven patients identified as Laron type dwarfism. We identified two missense mutations (S40L and W104R), and four polymorphisms (S473S, L526I, G168G and exon 3 deletion). We are reporting a mutation (W104R) at exon 5 of GHR gene that is not previously reported, and it is a novel mutation.

Prolactin receptor, growth hormone receptor, and putative somatolactin receptor in Mozambique tilapia: tissue specific expression and differential regulation by salinity and fasting.

Science.gov (United States)

Pierce, A L; Fox, B K; Davis, L K; Visitacion, N; Kitahashi, T; Hirano, T; Grau, E G

2007-01-01

In fish, pituitary growth hormone family peptide hormones (growth hormone, GH; prolactin, PRL; somatolactin, SL) regulate essential physiological functions including osmoregulation, growth, and metabolism. Teleost GH family hormones have both differential and overlapping effects, which are mediated by plasma membrane receptors. A PRL receptor (PRLR) and two putative GH receptors (GHR1 and GHR2) have been identified in several teleost species. Recent phylogenetic analyses and binding studies suggest that GHR1 is a receptor for SL. However, no studies have compared the tissue distribution and physiological regulation of all three receptors. We sequenced GHR2 from the liver of the Mozambique tilapia (Oreochromis mossambicus), developed quantitative real-time PCR assays for the three receptors, and assessed their tissue distribution and regulation by salinity and fasting. PRLR was highly expressed in the gill, kidney, and intestine, consistent with the osmoregulatory functions of PRL. PRLR expression was very low in the liver. GHR2 was most highly expressed in the muscle, followed by heart, testis, and liver, consistent with this being a GH receptor with functions in growth and metabolism. GHR1 was most highly expressed in fat, liver, and muscle, suggesting a metabolic function. GHR1 expression was also high in skin, consistent with a function of SL in chromatophore regulation. These findings support the hypothesis that GHR1 is a receptor for SL. In a comparison of freshwater (FW)- and seawater (SW)-adapted tilapia, plasma PRL was strongly elevated in FW, whereas plasma GH was slightly elevated in SW. PRLR expression was reduced in the gill in SW, consistent with PRL's function in freshwater adaptation. GHR2 was elevated in the kidney in FW, and correlated negatively with plasma GH, whereas GHR1 was elevated in the gill in SW. Plasma IGF-I, but not GH, was reduced by 4 weeks of fasting. Transcript levels of GHR1 and GHR2 were elevated by fasting in the muscle. However

MEL-18 loss mediates estrogen receptor-α downregulation and hormone independence.

Science.gov (United States)

Lee, Jeong-Yeon; Won, Hee-Young; Park, Ji-Hye; Kim, Hye-Yeon; Choi, Hee-Joo; Shin, Dong-Hui; Kang, Ju-Hee; Woo, Jong-Kyu; Oh, Seung-Hyun; Son, Taekwon; Choi, Jin-Woo; Kim, Sehwan; Kim, Hyung-Yong; Yi, Kijong; Jang, Ki-Seok; Oh, Young-Ha; Kong, Gu

2015-05-01

The polycomb protein MEL-18 has been proposed as a tumor suppressor in breast cancer; however, its functional relevance to the hormonal regulation of breast cancer remains unknown. Here, we demonstrated that MEL-18 loss contributes to the hormone-independent phenotype of breast cancer by modulating hormone receptor expression. In multiple breast cancer cohorts, MEL-18 was markedly downregulated in triple-negative breast cancer (TNBC). MEL-18 expression positively correlated with the expression of luminal markers, including estrogen receptor-α (ER-α, encoded by ESR1). MEL-18 loss was also associated with poor response to antihormonal therapy in ER-α-positive breast cancer. Furthermore, whereas MEL-18 loss in luminal breast cancer cells resulted in the downregulation of expression and activity of ER-α and the progesterone receptor (PR), MEL-18 overexpression restored ER-α expression in TNBC. Consistently, in vivo xenograft experiments demonstrated that MEL-18 loss induces estrogen-independent growth and tamoxifen resistance in luminal breast cancer, and that MEL-18 overexpression confers tamoxifen sensitivity in TNBC. MEL-18 suppressed SUMOylation of the ESR1 transactivators p53 and SP1, thereby driving ESR1 transcription. MEL-18 facilitated the deSUMOylation process by inhibiting BMI-1/RING1B-mediated ubiquitin-proteasomal degradation of SUMO1/sentrin-specific protease 1 (SENP1). These findings demonstrate that MEL-18 is a SUMO-dependent regulator of hormone receptors and suggest MEL-18 expression as a marker for determining the antihormonal therapy response in patients with breast cancer.

The diversity of abnormal hormone receptors in adrenal Cushing's syndrome allows novel pharmacological therapies

Directory of Open Access Journals (Sweden)

Lacroix A.

2000-01-01

Full Text Available Recent studies from several groups have indicated that abnormal or ectopic expression and function of adrenal receptors for various hormones may regulate cortisol production in ACTH-independent hypercortisolism. Gastric inhibitory polypeptide (GIP-dependent Cushing's syndrome has been described in patients with either unilateral adenoma or bilateral macronodular adrenal hyperplasia; this syndrome results from the large adrenal overexpression of the GIP receptor without any activating mutation. We have conducted a systematic in vivo evaluation of patients with adrenal Cushing's syndrome in order to identify the presence of abnormal hormone receptors. In macronodular adrenal hyperplasia, we have identified, in addition to GIP-dependent Cushing's syndrome, other patients in whom cortisol production was regulated abnormally by vasopressin, ß-adrenergic receptor agonists, hCG/LH, or serotonin 5HT-4 receptor agonists. In patients with unilateral adrenal adenoma, the abnormal expression or function of GIP or vasopressin receptor has been found, but the presence of ectopic or abnormal hormone receptors appears to be less prevalent than in macronodular adrenal hyperplasia. The identification of the presence of an abnormal adrenal receptor offers the possibility of a new pharmacological approach to control hypercortisolism by suppressing the endogenous ligands or by using specific antagonists for the abnormal receptors.

Molecular mechanism of action of pharmacoperone rescue of misrouted GPCR mutants: the GnRH receptor.

Science.gov (United States)

Janovick, Jo Ann; Patny, Akshay; Mosley, Ralph; Goulet, Mark T; Altman, Michael D; Rush, Thomas S; Cornea, Anda; Conn, P Michael

2009-02-01

The human GnRH receptor (hGnRHR), a G protein-coupled receptor, is a useful model for studying pharmacological chaperones (pharmacoperones), drugs that rescue misfolded and misrouted protein mutants and restore them to function. This technique forms the basis of a therapeutic approach of rescuing mutants associated with human disease and restoring them to function. The present study relies on computational modeling, followed by site-directed mutagenesis, assessment of ligand binding, effector activation, and confocal microscopy. Our results show that two different chemical classes of pharmacoperones act to stabilize hGnRHR mutants by bridging residues D(98) and K(121). This ligand-mediated bridge serves as a surrogate for a naturally occurring and highly conserved salt bridge (E(90)-K(121)) that stabilizes the relation between transmembranes 2 and 3, which is required for passage of the receptor through the cellular quality control system and to the plasma membrane. Our model was used to reveal important pharmacophoric features, and then identify a novel chemical ligand, which was able to rescue a D(98) mutant of the hGnRHR that could not be rescued as effectively by previously known pharmacoperones.

Calcium-Induced Activation of a Mutant G-Protein-Coupled Receptor Causes In Vitro Transformation of NIH/3T3 Cells

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Ana O. Hoff

1999-12-01

Full Text Available The calcium-sensing receptor (CaR is a G-proteincoupled receptor that is widely expressed, has tissuespecific functions, regulates cell growth. Activating mutations of this receptor cause autosomal dominant hypocalcemia, a syndrome characterized by hypocalcemia and hypercalciuria. The identification of a family with an activating mutation of the CaR (Thr151 Met in which hypocalcemia cosegregates with several unusual neoplasms led us to examine the transforming effects of this mutant receptor. Transfection of NIH/3T3 cells with the mutant but not the normal receptor supported colony formation in soft agar at subphysiologic calcium concentrations. The mutant CaR causes a calcium-dependent activation of the extracellular signal-regulated protein kinase (ERK 1/2 and Jun-N-terminal kinase/stress-activated (JNK/ SAPK pathways, but not P38 MAP kinase. These findings contribute to a growing body of information suggesting that this receptor plays a role in the regulation of cellular proliferation, that aberrant activation of the mutant receptor in this family may play a role in the unusual neoplastic manifestations.

Desensitization of parathyroid hormone receptors on cultured bone cells

International Nuclear Information System (INIS)

Pun, K.K.; Ho, P.W.; Nissenson, R.A.; Arnaud, C.D.

1990-01-01

Administration of excessive amounts of parathyroid hormone (PTH) in the treatment of osteoporosis can reverse the beneficial effects of a low-dose, intermittent regime. To investigate the direct actions and the possible cellular mechanisms of PTH in inducing desensitization of PTH receptors, we studied the effects of desensitization on rat osteoblastic UMR-106 cells. When the osteoblasts were preincubated with bPTH-(1-34), complete refractoriness to a subsequent challenge with the hormone developed within 1 h and at hormone concentrations as low as 5 nM. When osteoblasts thus desensitized were incubated in hormone-free medium, recovery of the cAMP responses began within 2 h and reached maximum after 16 h. Cycloheximide did not affect the process of desensitization. [Nle8,Nle18,Tyr34]bPTH-(3-34)amide significantly impaired the desensitization process by PTH-(1-34) but did not have stimulatory effect on cAMP responses. No significant heterologous desensitization was obvious after preincubation with isoprenaline (50 microM), prostaglandin E1 (50 microM), or prostaglandin E2 (50 microM) for 2 h. Binding experiments with [125I]PLP-(1-36)amide after desensitization revealed that there was an approximate twofold decrease in receptor affinities as analyzed by Scatchard analysis, showing that the decrease in affinity was prominent in the process of desensitization. When the cells were treated with monensin during desensitization, PTH challenge after desensitization produced significantly lower cyclic AMP responses. Recovery after desensitization occurred over a period of 16 h. Inclusion of monensin, but not cycloheximide, impaired the recovery. The results show that homologous desensitization of rat osteoblasts to PTH is brought about by the occupancy of receptors by PTH-(1-34) but not by cAMP generation itself

The Hypercoagulable state in Hyperthyroidism is mediated via the Thyroid Hormone β Receptor pathway

NARCIS (Netherlands)

Elbers, Laura P. B.; Moran, Carla; Gerdes, Victor E. A.; van Zaane, Bregje; Meijers, Joost C. M.; Endert, Erik; Lyons, Greta; Chatterjee, V. Krishna; Bisschop, Peter H.; Fliers, Eric

2016-01-01

Hyperthyroidism is associated with a hypercoagulable state, but the underlying mechanism is unknown. Patients with resistance to thyroid hormone (RTH) due to defective thyroid hormone receptor β (TRβ) exhibit elevated circulating thyroid hormones (TH) with refractoriness to TH action in

Evidence for cooperative signal triggering at the extracellular loops of the TSH receptor.

Science.gov (United States)

Kleinau, Gunnar; Jaeschke, Holger; Mueller, Sandra; Raaka, Bruce M; Neumann, Susanne; Paschke, Ralf; Krause, Gerd

2008-08-01

The mechanisms governing transition of the thyroid stimulating hormone (TSH) receptor (TSHR) from basal to active conformations are poorly understood. Considering that constitutively activating mutations (CAMs) and inactivating mutations in each of the extracellular loops (ECLs) trigger only partial TSHR activation or inactivation, respectively, we hypothesized that full signaling occurs via multiple extracellular signal propagation events. Therefore, individual CAMs in the extracellular region were combined to create double and triple mutants. In support of our hypothesis, combinations of mutants in the ECLs are in some cases additive, while in others they are even synergistic, with triple mutant I486A/I568V/V656F exhibiting a 70-fold increase in TSH-independent signaling. The proximity but likely different spatial orientation of the residues of activating and inactivating mutations in each ECL supports a dual functionality to facilitate signal induction and conduction, respectively. This is the first report for G-protein coupled receptors, suggesting that multiple and cooperative signal propagating events at all three ECLs are required for full receptor activation. Our findings provide new insights concerning molecular signal transmission from extracellular domains toward the transmembrane helix bundle of the glycoprotein hormone receptors.

Research resource: novel structural insights bridge gaps in glycoprotein hormone receptor analyses.

Science.gov (United States)

Kreuchwig, Annika; Kleinau, Gunnar; Krause, Gerd

2013-08-01

The first version of a glycoprotein hormone receptor (GPHR) information resource was designed to link functional with structural GPHR information, in order to support sequence-structure-function analysis of the LH, FSH, and TSH receptors (http://ssfa-gphr.de). However, structural information on a binding- and signaling-sensitive extracellular fragment (∼100 residues), the hinge region, had been lacking. A new FSHR crystal structure of the hormone-bound extracellular domain has recently been solved. The structure comprises the leucine-rich repeat domain and most parts of the hinge region. We have not only integrated the new FSHR/FSH structure and the derived homology models of TSHR/TSH, LHCGR/CG, and LHCGR/LH into our web-based information resource, but have additionally provided novel tools to analyze the advanced structural features, with the common characteristics and distinctions between GPHRs, in a more precise manner. The hinge region with its second hormone-binding site allows us to assign functional data to the new structural features between hormone and receptor, such as binding details of a sulfated tyrosine (conserved throughout the GPHRs) extending into a pocket of the hormone. We have also implemented a protein interface analysis tool that enables the identification and visualization of extracellular contact points between interaction partners. This provides a starting point for comparing the binding patterns of GPHRs. Together with the mutagenesis data stored in the database, this will help to decipher the essential residues for ligand recognition and the molecular mechanisms of signal transduction, extending from the extracellular hormone-binding site toward the intracellular G protein-binding sites.

Desethylamiodarone is a competitive inhibitor of the binding of thyroid hormone to the thyroid hormone alpha 1-receptor protein

NARCIS (Netherlands)

van Beeren, H. C.; Bakker, O.; Wiersinga, W. M.

1995-01-01

Desethylamiodarone (DEA), the major metabolite of the potent antiarrythmic drug amiodarone, is a non-competitive inhibitor of the binding of thyroid hormone (T3) to the beta 1-thyroid hormone receptor (T3R). In the present study, we investigated whether DEA acts in a similar way with respect to the

Analysis of the hormone-binding domain of steroid receptors using chimeras generated by homologous recombination

International Nuclear Information System (INIS)

Martinez, Elisabeth D.; Pattabiraman, Nagarajan; Danielsen, Mark

2005-01-01

The glucocorticoid receptor and the mineralocorticoid receptor are members of the steroid receptor family that exhibit ligand cross-reactivity. Specificity of steroid receptor action is investigated in the present work by the construction and characterization of chimeras between the glucocorticoid receptor and the mineralocorticoid receptor. We used an innovative approach to make novel steroid receptor proteins in vivo that in general, contrary to our expectations, show increased ligand specificity compared to the parental receptors. We describe a receptor that is specific for the potent synthetic glucocorticoid triamcinolone acetonide and does not bind aldosterone. A further set of chimeras has an increased ability to discriminate between ligands, responding potently to mineralocorticoids and only very weakly to synthetic glucocorticoids. A chimera with the fusion site in the hinge highlights the importance of the region between the DNA-binding and the hormone-binding domains since, unlike both the glucocorticoid and mineralocorticoid receptors, it only responds to mineralocorticoids. One chimera has reduced specificity in that it acts as a general corticoid receptor, responding to glucocorticoids and mineralocorticoids with similar potency and efficacy. Our data suggest that regions of the glucocorticoid and mineralocorticoid receptor hormone-binding domains are functionally non-reciprocal. We present transcriptional, hormone-binding, and structure-modeling evidence that suggests that receptor-specific interactions within and across domains mediate aspects of specificity in transcriptional responses to steroids

Actin-Sorting Nexin 27 (SNX27)-Retromer Complex Mediates Rapid Parathyroid Hormone Receptor Recycling*

Science.gov (United States)

McGarvey, Jennifer C.; Xiao, Kunhong; Bowman, Shanna L.; Mamonova, Tatyana; Zhang, Qiangmin; Bisello, Alessandro; Sneddon, W. Bruce; Ardura, Juan A.; Jean-Alphonse, Frederic; Vilardaga, Jean-Pierre; Puthenveedu, Manojkumar A.; Friedman, Peter A.

2016-01-01

The G protein-coupled parathyroid hormone receptor (PTHR) regulates mineral-ion homeostasis and bone remodeling. Upon parathyroid hormone (PTH) stimulation, the PTHR internalizes into early endosomes and subsequently traffics to the retromer complex, a sorting platform on early endosomes that promotes recycling of surface receptors. The C terminus of the PTHR contains a type I PDZ ligand that binds PDZ domain-containing proteins. Mass spectrometry identified sorting nexin 27 (SNX27) in isolated endosomes as a PTHR binding partner. PTH treatment enriched endosomal PTHR. SNX27 contains a PDZ domain and serves as a cargo selector for the retromer complex. VPS26, VPS29, and VPS35 retromer subunits were isolated with PTHR in endosomes from cells stimulated with PTH. Molecular dynamics and protein binding studies establish that PTHR and SNX27 interactions depend on the PDZ recognition motif in PTHR and the PDZ domain of SNX27. Depletion of either SNX27 or VPS35 or actin depolymerization decreased the rate of PTHR recycling following agonist stimulation. Mutating the PDZ ligand of PTHR abolished the interaction with SNX27 but did not affect the overall rate of recycling, suggesting that PTHR may directly engage the retromer complex. Coimmunoprecipitation and overlay experiments show that both intact and mutated PTHR bind retromer through the VPS26 protomer and sequentially assemble a ternary complex with PTHR and SNX27. SNX27-independent recycling may involve N-ethylmaleimide-sensitive factor, which binds both PDZ intact and mutant PTHRs. We conclude that PTHR recycles rapidly through at least two pathways, one involving the ASRT complex of actin, SNX27, and retromer and another possibly involving N-ethylmaleimide-sensitive factor. PMID:27008860

Modulation of thyroid hormone receptor transactivation by the early region 1A (E1A-like inhibitor of differentiation 1 (EID1

Directory of Open Access Journals (Sweden)

Diana Vargas

2008-01-01

Full Text Available Transcriptional activation (TA mediated by the effect of thyroid hormones on target genes requires co-activator proteins such as the early region 1A (E1A associated 300 kDa binding protein (p300 and the cAMP response element binding protein (CREB binding protein (CBP, known as the p300/CBP complex, which acetylate histones 3 and 4 to allow transcriptional machinery access to the target gene promoter. Little is known on the role of p300 in thyroid hormone receptor (TR mediated TA but the E1A-like inhibitor of differentiation 1 (EID1, an inhibitor of p300 histone acetyltransferase (HAT, is a functional homolog of E1A and may inhibit myogenic differentiation factor D (MyoD transcriptional activity and reduces muscle cell differentiation. We evaluated the influence of EID1 on TR-mediated transcriptional activity using transfection and mammalian two-hybrid studies to show that EID1 may partially reduces TA activity of the TR receptor, probably due to p300 blockage since EID1 mutants cannot reduce TR-mediated TA. The EID1 does not affect the function of p160 co-activator proteins (160 kDa proteins of steroid receptor co-activators and is functionally independent of co-repressor proteins or TR binding. Summarizing, EID1 reduces TR-mediated transcriptional activity by blocking p300 and may play an important role in thyroid receptor activity in muscle and other tissues.

Steroid hormone and epidermal growth factor receptors in meningiomas.

Science.gov (United States)

Horsfall, D J; Goldsmith, K G; Ricciardelli, C; Skinner, J M; Tilley, W D; Marshall, V R

1989-11-01

A prospective study of steroid hormone and epidermal growth factor receptor expression in 57 meningiomas is presented. Scatchard analysis of radioligand binding identified 20% of meningiomas as expressing classical oestrogen receptors (ER) at levels below that normally accepted for positivity, the remainder being negative. ER could not be visualized in any meningioma using immunocytochemistry. Alternatively, 74% of meningiomas demonstrated the presence of progesterone receptors (PR) by Scatchard analysis, the specificity of which could not be attributed to glucocorticoid or androgen receptors. Confirmation of classical PR presence was determined by immunocytochemical staining. The presence of epidermal growth factor receptor (EGFR) was demonstrated in 100% of meningiomas using immunocytochemical staining. These data are reviewed in the context of previously reported results and are discussed in relation to the potential for medical therapy as an adjunct to surgery.

Evidence for association of the cloned liver growth hormone receptor with a tyrosine kinase

DEFF Research Database (Denmark)

Wang, X; Uhler, M D; Billestrup, N

1992-01-01

The ability of the cloned liver growth hormone (GH) receptor, when expressed in mammalian cell lines, to copurify with tyrosine kinase activity and be tyrosyl phosphorylated was examined. 125I-human growth hormone-GH receptor complexes isolated from COS-7 cells transiently expressing high levels...... of tyrosine kinase activity with cloned liver GH receptor. The level of phosphorylation of the GH receptor was very low, as compared with the endogenous GH receptor in 3T3-F442A cells, suggesting that tyrosine kinase activity is not intrinsic to the cloned GH receptor but rather resides with a kinase present...... in a variety of cell types. The finding that the level of phosphorylation of GH receptor appears to vary with cell type is consistent with the cloned liver GH receptor being a substrate for an associated tyrosine kinase and with the amount of such a GH receptor-associated tyrosine kinase being cell type-specific....

Polymorphism of growth hormone receptor (GHR gene in Holstein Friesian dairy cattle

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Restu Misrianti

2011-12-01

Full Text Available Growth hormone gene have a critical role in the regulation of lactation, mammary gland development and growth process through its interaction with a specific receptor. Growth hormone (GH is an anabolic hormone which is synthesized and secreted by somatotrop cell in pituitary anterior lobe, and interacts with a specific receptor on the surface of the target cells. Growth hormone receptor (GHR has been suggested as candidate gene for traits related to milk production in Bovidae. The purpose of this study was to identify genetic polymorphism of the Growth Hormone Receptor (GHR genes in Holstein Friesian (HF cattle. Total of 353 blood samples were collected from five populations belonging to Cikole Dairy Cattle Breeding Station (BPPT-SP Cikole (88 samples, Pasir Kemis (95 samples, Cilumber (98 samples, Cipelang Livestock Embryo Center (BET Cipelang (40 samples, Singosari National Artificial Insemination Centre (BBIB Singosari (32 samples and 17 frozen semen samples from Lembang Artificial Insemination Center (BIB Lembang. Genomic DNAs were extracted by a standard phenol-chloroform protocol and amplified by a polymerase chain reaction (PCR techniques then PCR products were genotyped by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP methods. There were two allele dan three genotypes were found namely: allele A and G, Genotype AA, AG and GG repectively. Allele A frequency (0.70-0.82 relatively higher than allele G frequency (0.18-0.30. Chi square test show that on group of BET Cipelang, BIB Lembang and BBIB Singosari population were not significantly different (0.00-0.93, while on group of BET Cipelang, BIB Lembang dan BBIB Singosari population were significantly different (6.02-11.13. Degree of observed heterozygosity (Ho ranged from 0.13-0.42 and expected heterozygosity (He ranged from 0.29-0.42.

A novel Arabidopsis CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) mutant with enhanced pathogen-induced cell death and altered receptor processing.

Science.gov (United States)

Petutschnig, Elena K; Stolze, Marnie; Lipka, Ulrike; Kopischke, Michaela; Horlacher, Juliane; Valerius, Oliver; Rozhon, Wilfried; Gust, Andrea A; Kemmerling, Birgit; Poppenberger, Brigitte; Braus, Gerhard H; Nürnberger, Thorsten; Lipka, Volker

2014-12-01

Plants detect pathogens by sensing microbe-associated molecular patterns (MAMPs) through pattern recognition receptors. Pattern recognition receptor complexes also have roles in cell death control, but the underlying mechanisms are poorly understood. Here, we report isolation of cerk1-4, a novel mutant allele of the Arabidopsis chitin receptor CERK1 with enhanced defense responses. We identified cerk1-4 in a forward genetic screen with barley powdery mildew and consequently characterized it by pathogen assays, mutant crosses and analysis of defense pathways. CERK1 and CERK1-4 proteins were analyzed biochemically. The cerk1-4 mutation causes an amino acid exchange in the CERK1 ectodomain. Mutant plants maintain chitin signaling capacity but exhibit hyper-inducible salicylic acid concentrations and deregulated cell death upon pathogen challenge. In contrast to chitin signaling, the cerk1-4 phenotype does not require kinase activity and is conferred by the N-terminal part of the receptor. CERK1 undergoes ectodomain shedding, a well-known process in animal cell surface proteins. Wild-type plants contain the full-length CERK1 receptor protein as well as a soluble form of the CERK1 ectodomain, whereas cerk1-4 plants lack the N-terminal shedding product. Our work suggests that CERK1 may have a chitin-independent role in cell death control and is the first report of ectodomain shedding in plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Do unliganded thyroid hormone receptors have physiological functions?

Science.gov (United States)

Chassande, O

2003-08-01

Thyroid hormone (TH) is required for the development of vertebrates and exerts numerous homeostatic functions in adults. TH acts through nuclear receptors which control the transcription of target genes. Unliganded and liganded thyroid hormone receptors (TRs) have been shown to exert opposite effects on the transcription of target genes in vitro. However, the occurance of an aporeceptor activity in vivo and its potential physiological significance has not been clearly addressed. Several data generated using experimental hypothyroidism and thyrotoxicosis in wild type and TR knockout mice support the notion that apoTRs have an intrinsic activity in several tIssues. ApoTRs, and in particular TRalpha1, are predominant during the early stages of vertebrate development and must be turned into holoTRs for post-natal development to proceed normally. However, the absence of striking alterations of embryonic and fetal development in mice devoid of TRs indicates that apoTRs do not play a fundamental role. During development, as well as in adults, apoTRs rather appears as a system which increases the range of transcriptional responses to moderate variations of T3.

Hormonal regulation of AMPA receptor trafficking and memory formation

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Harmen J Krugers

2009-10-01

Full Text Available Humans and rodents retain memories for stressful events very well. The facilitated retention of these memories is normally very useful. However, in susceptible individuals a variety of pathological conditions may develop in which memories related to stressful events remain inappropriately present, such as in post-traumatic stress disorder. The memory enhancing effects of stress are mediated by hormones, such as norepinephrine and glucocorticoids which are released during stressful experiences. Here we review recently identified molecular mechanisms that underlie the effects of stress hormones on synaptic efficacy and learning and memory. We discuss AMPA receptors as major target for stress hormones and describe a model in which norepinephrine and glucocorticoids are able to strengthen and prolong different phases of stressful memories.

Growth hormone receptor deficiency (Laron syndrome) in black ...

African Journals Online (AJOL)

Non-Caucasians with growth honnone receptor (GHR) deficiency/Lamn syndrome among the .... 4,3 cm (-2,4 SOS for bone age 8,5 years at age 12); the girl's height at age 7 years was 77,5 cm (-8,0 SOS, height ... of serum incubated with '25I-labelled human growth hormone and expressed as relative specific binding ...

Study of change of sex hormone receptors in diabetic impotent patients

International Nuclear Information System (INIS)

Zhang Yong; Chen Weizhen; Zhang Zikang; Hu Xiaoke

2002-01-01

To study the relationship between diabetic impotence and sex hormones as well as sex hormone receptors. 32 diabetic impotent patients, 32 diabetic patients with normal sex function, 32 impotent patients without diabetes, and 40 healthy men were enrolled. The plasma sex hormone levels were examined by radioimmunoassay, and sex hormone receptors in white blood cells by radioreceptor assay. Compared with healthy men and impotent patients without diabetes, PRL levels in both diabetic impotent patients and diabetic patients with normal sex function increased markedly, T and AR levels decreased, and the ratio of E 2 /T and ER/AR increased. Compared with diabetic patients with normal sex function, while there was no significant difference in PRL, T and E 2 /T ratio, the AR level of diabetic impotent patients further decreased, and the ER/AR ratio further increased. Negative correlation was found between age and AR as well as T. The decline of AR and the increase of ER/AR ratio might be one main cause of diabetic impotence. And the decline of T and AR might be an important cause of the increase of diabetic impotence incidence with age

Growth hormone (GH)-independent dimerization of GH receptor by a leucine zipper results in constitutive activation

DEFF Research Database (Denmark)

Behncken, S N; Billestrup, Nils; Brown, R

2000-01-01

Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers of the gro......Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers...

Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease.

Science.gov (United States)

Khalil, Raouf A

2013-12-15

Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. Copyright © 2013 Elsevier Inc. All rights reserved.

Structural Basis for a Switch in Receptor Binding Specificity of Two H5N1 Hemagglutinin Mutants

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Xueyong Zhu

2015-11-01

Full Text Available Avian H5N1 influenza viruses continue to spread in wild birds and domestic poultry with sporadic infection in humans. Receptor binding specificity changes are a prerequisite for H5N1 viruses and other zoonotic viruses to be transmitted among humans. Previous reported hemagglutinin (HA mutants from ferret-transmissible H5N1 viruses of A/Vietnam/1203/2004 and A/Indonesia/5/2005 showed slightly increased, but still very weak, binding to human receptors. From mutagenesis and glycan array studies, we previously identified two H5N1 HA mutants that could more effectively switch receptor specificity to human-like α2-6-linked sialosides with avidity comparable to wild-type H5 HA binding to avian-like α2-3-linked sialosides. Here, crystal structures of these two H5 HA mutants free and in complex with human and avian glycan receptor analogs reveal the structural basis for their preferential binding to human receptors. These findings suggest continuous surveillance should be maintained to monitor and assess human-to-human transmission potential of H5N1 viruses.

Negative regulation of parathyroid hormone-related protein expression by steroid hormones

International Nuclear Information System (INIS)

Kajitani, Takashi; Tamamori-Adachi, Mimi; Okinaga, Hiroko; Chikamori, Minoru; Iizuka, Masayoshi; Okazaki, Tomoki

2011-01-01

Highlights: → Steroid hormones repress expression of PTHrP in the cell lines where the corresponding nuclear receptors are expressed. → Nuclear receptors are required for suppression of PTHrP expression by steroid hormones, except for androgen receptor. → Androgen-induced suppression of PTHrP expression appears to be mediated by estrogen receptor. -- Abstract: Elevated parathyroid hormone-related protein (PTHrP) is responsible for humoral hypercalcemia of malignancy (HHM), which is of clinical significance in treatment of terminal patients with malignancies. Steroid hormones were known to cause suppression of PTHrP expression. However, detailed studies linking multiple steroid hormones to PTHrP expression are lacking. Here we studied PTHrP expression in response to steroid hormones in four cell lines with excessive PTHrP production. Our study established that steroid hormones negatively regulate PTHrP expression. Vitamin D receptor, estrogen receptor α, glucocorticoid receptor, and progesterone receptor, were required for repression of PTHrP expression by the cognate ligands. A notable exception was the androgen receptor, which was dispensable for suppression of PTHrP expression in androgen-treated cells. We propose a pathway(s) involving nuclear receptors to suppress PTHrP expression.

Antitumor Responses Stimulated by Dendritic Cells Are Improved by Triiodothyronine Binding to the Thyroid Hormone Receptor β.

Science.gov (United States)

Alamino, Vanina A; Mascanfroni, Iván D; Montesinos, María M; Gigena, Nicolás; Donadio, Ana C; Blidner, Ada G; Milotich, Sonia I; Cheng, Sheue-Yann; Masini-Repiso, Ana M; Rabinovich, Gabriel A; Pellizas, Claudia G

2015-04-01

Bidirectional cross-talk between the neuroendocrine and immune systems orchestrates immune responses in both physiologic and pathologic settings. In this study, we provide in vivo evidence of a critical role for the thyroid hormone triiodothyronine (T3) in controlling the maturation and antitumor functions of dendritic cells (DC). We used a thyroid hormone receptor (TR) β mutant mouse (TRβPV) to establish the relevance of the T3-TRβ system in vivo. In this model, TRβ signaling endowed DCs with the ability to stimulate antigen-specific cytotoxic T-cell responses during tumor development. T3 binding to TRβ increased DC viability and augmented DC migration to lymph nodes. Moreover, T3 stimulated the ability of DCs to cross-present antigens and to stimulate cytotoxic T-cell responses. In a B16-OVA mouse model of melanoma, vaccination with T3-stimulated DCs inhibited tumor growth and prolonged host survival, in part by promoting the generation of IFNγ-producing CD8(+) T cells. Overall, our results establish an adjuvant effect of T3-TRβ signaling in DCs, suggesting an immediately translatable method to empower DC vaccination approaches for cancer immunotherapy. ©2015 American Association for Cancer Research.

Rapid, portable detection of endocrine disrupting chemicals through ligand-nuclear hormone receptor interactions.

Science.gov (United States)

Hunt, J Porter; Schinn, Song-Min; Jones, Matthew D; Bundy, Bradley C

2017-12-04

Endocrine disrupting chemicals (EDC) are structurally diverse compounds that can interact with nuclear hormone receptors, posing significant risk to human and ecological health. Unfortunately, many conventional biosensors have been too structure-specific, labor-intensive or laboratory-oriented to detect broad ranges of EDC effectively. Recently, several technological advances are providing more rapid, portable, and affordable detection of endocrine-disrupting activity through ligand-nuclear hormone receptor interactions. Here, we overview these recent advances applied to EDC biosensors - including cell lyophilization, cell immobilization, cell-free systems, smartphone-based signal detection, and improved competitive binding assays.

Sex Steroid Hormone Receptor Expression Affects Ovarian Cancer Survival

DEFF Research Database (Denmark)

Jönsson, Jenny-Maria; Skovbjerg Arildsen, Nicolai; Malander, Susanne

2015-01-01

BACKGROUND AND AIMS: Although most ovarian cancers express estrogen (ER), progesterone (PR), and androgen (AR) receptors, they are currently not applied in clinical decision making. We explored the prognostic impact of sex steroid hormone receptor protein and mRNA expression on survival...... in epithelial ovarian cancer. METHODS: Immunohistochemical stainings for ERα, ERβ, PR, and AR were assessed in relation to survival in 118 serous and endometrioid ovarian cancers. Expression of the genes encoding the four receptors was studied in relation to prognosis in the molecular subtypes of ovarian cancer...... in ovarian cancer and support that tumors should be stratified based on molecular as well as histological subtypes in future studies investigating the role of endocrine treatment in ovarian cancer....

Estradiol potentiation of gonadotropin-releasing hormone responsiveness in the anterior pituitary is mediated by an increase in gonadotropin-releasing hormone receptors

International Nuclear Information System (INIS)

Menon, M.; Peegel, H.; Katta, V.

1985-01-01

In order to investigate the mechanism by which 17 beta-estradiol potentiates the action of gonadotropin-releasing hormone on the anterior pituitary in vitro, cultured pituitary cells from immature female rats were used as the model system. Cultures exposed to estradiol at concentrations ranging from 10(-10) to 10(-6) mol/L exhibited a significant augmentation of luteinizing hormone release in response to a 4-hour gonadotropin-releasing hormone (10 mumol/L) challenge at a dose of 10(-9) mol/L compared to that of control cultures. The estradiol augmentation of luteinizing hormone release was also dependent on the duration of estradiol exposure. When these cultures were incubated with tritium-labeled L-leucine, an increase in incorporation of radiolabeled amino acid into total proteins greater than that in controls was observed. A parallel stimulatory effect of estradiol on iodine 125-labeled D-Ala6 gonadotropin-releasing hormone binding was observed. Cultures incubated with estradiol at different concentrations and various lengths of time showed a significant increase in gonadotropin-releasing hormone binding capacity and this increase was abrogated by cycloheximide. Analysis of the binding data showed that the increase in gonadotropin-releasing hormone binding activity was due to a change in the number of gonadotropin-releasing hormone binding sites rather than a change in the affinity. These results suggest that (1) estradiol treatment increases the number of pituitary receptors for gonadotropin-releasing hormone, (2) the augmentary effect of estradiol on luteinizing hormone release at the pituitary level might be mediated, at least in part, by the increase in the number of binding sites of gonadotropin-releasing hormone, and (3) new protein synthesis may be involved in estradiol-mediated gonadotropin-releasing hormone receptor induction

Regulation of C. elegans fat uptake and storage by acyl-CoA synthase-3 is dependent on NR5A family nuclear hormone receptor nhr-25

DEFF Research Database (Denmark)

Mullaney, Brendan C; Blind, Raymond D; Lemieux, George A

2010-01-01

Acyl-CoA synthases are important for lipid synthesis and breakdown, generation of signaling molecules, and lipid modification of proteins, highlighting the challenge of understanding metabolic pathways within intact organisms. From a C. elegans mutagenesis screen, we found that loss of ACS-3...... mutant phenotypes require the nuclear hormone receptor NHR-25, a key regulator of C. elegans molting. Our findings suggest that ACS-3-derived long-chain fatty acyl-CoAs, perhaps incorporated into complex ligands such as phosphoinositides, modulate NHR-25 function, which in turn regulates an endocrine...... program of lipid uptake and synthesis. These results reveal a link between acyl-CoA synthase function and an NR5A family nuclear receptor in C. elegans....

Structural Stereochemistry of Androstene Hormones Determines Interactions with Human Androgen, Estrogen, and Glucocorticoid Receptors

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Thomas L. Shaak

2013-01-01

Full Text Available DHEA, 17α-AED, 17β-AED, and 17β-AET exhibit strong biological activity that has been attributed to androgenic, estrogenic, or antiglucocorticoid activity in vivo and in vitro. This study compared DHEA, 17α-AED, 17β-AED, and 17β-AET for their ability to activate the human AR, ER, and GR and determine the relative androgenicity, estrogenicity, and glucocorticoid activity. The results show that, at the receptor level, these androstene hormones are weak AR and even weaker ER activators. Direct androstene hormone activation of the human AR, ERα, and ERβ may not be essential for their biological function. Similarly, these hormones indirectly activated the human GR, only in the presence of high dexamethasone concentrations. These results underscore the major difference between androstene hormone interactions with these nuclear receptors and their biological effects.

Radioactive probes for adrenocorticotropic hormone receptors

International Nuclear Information System (INIS)

Hofmann, K.; Romovacek, H.; Stehle, C.J.; Finn, F.M.; Bothner-By, A.A.; Mishra, P.K.

1986-01-01

Our attempts to develop adrenocorticotropic hormone (ACTH) analogues that can be employed for ACTH receptor identification and isolation began with the synthesis of ACTH fragments containing N epsilon-(dethiobiotinyl)lysine (dethiobiocytin) amide in position 25 to be used for affinity chromatographic purification of hormone-receptor complexes on Sepharose-immobilized avidin resins. Because labeling ACTH or ACTH fragments by conventional iodination techniques destroys biological activity due to oxidation of Met4 and incorporation of iodine into Tyr2, we have prepared [Phe2,Nle4]ACTH1-24, [Phe2,Nle4,biocytin25]ACTH1-25 amide, and [Phe2,Nle4,dethiobiocytin25]ACTH1-25 amide by conventional synthetic techniques. The HPLC profiles and amino acid analyses of the final products indicate that the materials are of a high degree of purity. The amount of tertiary butylation of the Trp residue in the peptides was assessed by NMR and was found to be less than 0.5%. All three peptides are equipotent with the standard ACTH1-24 as concerns their ability to stimulate steroidogenesis and cAMP formation in bovine adrenal cortical cells. Iodination of [Phe2,Nle4]ACTH1-24, with iodogen as the oxidizing agent, has been accomplished without any detectable loss of biological activity. The mono- and diiodo derivatives of [Phe2,Nle4]ACTH1-24 have been prepared, separated by HPLC, and assayed for biological activity. Both peptides have the full capacity to stimulate steroidogenesis and cAMP production in bovine adrenal cortical cells

A radioreceptor assay of luteinizing hormone-releasing hormone receptor and characterization of LHRH binding to pituitary receptors in Shao duck

International Nuclear Information System (INIS)

Yang Peixin; Wu Meiwen; Chen Ziyuan

2000-01-01

The properties of Shao duck pituitary luteinizing hormone-releasing hormone (LHRH) receptors were analyzed in pituitary membrane preparation and isolated pituitary cells prepared by enzymatic dispersion with collagenase and trypsin, by using a super-agonist analog of (D-Lys 6 ) LHRH. High binding of 125 I-(D-Lys 6 ) LHRH to 10 6 cultured cells of Shao duck was observed after a 90 minute incubation at 4 degree C, while binding was significantly reduced after a 24h incubation. Binding of the radioligand was a function of tissue concentration of Shao duck pituitary membrane preparation, with a positive correlation over the range of 1-2 pituitary per-tube. Specific binding for 125 I-(D-Lys 6 ) LHRH increased with the increase in the amount of 125 I-(D-Lys 6 ) LHRH. The Scatchard analysis of data revealed a linear relationship between the amount of specific binding and the ratio of specific binding to free 1 '2 5 I(D-Lys 6 )LHRH, indicating a single class of high affinity sites. Equilibrium dissociation constant (Kd) was 0.34 nM in pituitary membrane preparation and 0.43 nM in isolated pituitary cells. Both Kd values were near and the maximum binding capacity (B max ) was great in isolated cells, suggesting no significant loss of the LHRH receptor population caused by the enzymatic procedure employed for cell dispersion in the present study. Addition of 9D-Lys 6 ) LHRH displaced bound 125 I-(D-Lys 6 ) LHRH. These results demonstrated the presence and provided characterization of LHRH receptors in Shao duck pituitary

A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

KAUST Repository

Melcher, Karsten

2009-12-03

Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

A gate-latch-lock mechanism for hormone signalling by abscisic acid receptors

KAUST Repository

Melcher, Karsten; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Xu, Yong; Suino-Powell, Kelly M.; Park, Sang-Youl; Weiner, Joshua J.; Fujii, Hiroaki; Chinnusamy, Viswanathan; Kovach, Amanda; Li, Jun; Wang, Yonghong; Li, Jiayang; Peterson, Francis C.; Jensen, Davin R.; Yong, Eu-Leong; Volkman, Brian F.; Cutler, Sean R.; Zhu, Jian-Kang; Xu, H. Eric

2009-01-01

Abscisic acid (ABA) is a ubiquitous hormone that regulates plant growth, development and responses to environmental stresses. Its action is mediated by the PYR/PYL/RCAR family of START proteins, but it remains unclear how these receptors bind ABA and, in turn, how hormone binding leads to inhibition of the downstream type 2C protein phosphatase (PP2C) effectors. Here we report crystal structures of apo and ABA-bound receptors as well as a ternary PYL2-ABA-PP2C complex. The apo receptors contain an open ligand-binding pocket flanked by a gate that closes in response to ABA by way of conformational changes in two highly conserved ?-loops that serve as a gate and latch. Moreover, ABA-induced closure of the gate creates a surface that enables the receptor to dock into and competitively inhibit the PP2C active site. A conserved tryptophan in the PP2C inserts directly between the gate and latch, which functions to further lock the receptor in a closed conformation. Together, our results identify a conserved gate-latch-lock mechanism underlying ABA signalling. © 2009 Macmillan Publishers Limited. All rights reserved.

Expression of insulin-like growth factor-1 and insulin-like growth factor-1 receptors in EL4 lymphoma cells overexpressing growth hormone.

Science.gov (United States)

Weigent, Douglas A; Arnold, Robyn E

2005-03-01

Almost all of the previous studies with growth hormone (GH) have been done with exogenously supplied GH and, therefore, involve actions of the hormone through its receptor. However, the actions of endogenous or lymphocyte GH are still unclear. In a previous study, we showed that overexpression of GH (GHo) in a lymphoid cell line resulted in protection of the cells to apoptosis mediated by nitric oxide (NO). In the present study, we show that the protection from apoptosis could be transferred to control cells with culture fluids obtained from GHo cells and blocked by antibodies to the insulin-like growth factor-1 (IGF-1) or antibodies to the IGF-1-receptor (IGF-1R). Northern and Western blot analysis detected significantly higher levels of IGF-1 in cells overexpressing GH. An increase in the expression of the IGF-1R in GHo cells was also detected by Western blot analysis, (125)I-IGF-1 binding and analysis of IGF-1R promoter luciferase constructs. Transfection of GHo cells with a dominant negative IGF-1R mutant construct blocked the generation of NO and activation of Akt seen in GHo cells compared to vector alone control EL4 cells. The results suggest that one of the consequences of the overexpression of GH, in cells lacking the GH receptor, is an increase in the expression of IGF-1 and the IGF-1R which mediate the protection of EL4 lymphoma cells from apoptosis.

Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus.

Directory of Open Access Journals (Sweden)

Janice K V Tam

Full Text Available The evolutionary trajectories of growth hormone-releasing hormone (GHRH receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP receptor (PRPR. In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2 had the highest expression in brain, and interestingly, X. laevis(GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.

Pituitary resistance to thyroid hormone associated with a base mutation in the hormone-binding domain of the human 3, 5,3[prime]-triiodothyronine receptor-[beta

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Shigekazu; Nakamura, Hirotoshi; Tagami, Tetsuya; Miyoshi, Yohzi; Nogimori, Tsuyoshi; Mitsuma, Terunori; Imura, Hiroo (Kyoto Univ. School of Medicine, Aichi (Japan))

1993-05-01

Point mutations in the human T[sub 3] receptor-[beta] (TR[beta]) gene causing single amino acid substitutions have been identified in several different kindred with generalized resistance to thyroid hormone. Until now, no study has been reported on the TR gene in cases of pituitary resistance (PRTH). In the present study, the authors analyzed the TR[beta] gene in a 30-yr-old Japanese female with PRTH. She exhibited clinical features of hyperthyroidism, elevated serum thyroid hormone levels accompanied by inappropriately increased secretion of TSH, mildly elevated basal metabolic rate, and increased urinary excretion of hydroxyproline. No pituitary tumor was detected. DNA fragments of exons 3-8 of the geonomic TR[beta] gene were generated by the polymerase chain reaction and analyzed by a single stranded conformation polymorphism method. Exon 7 of the patient's TR[beta] gene showed an abnormal band, suggesting the existence of mutation(s). By subcloning and sequencing the DNA, a point mutation was identified in one allele at nucleotide 1297 (C to T), which altered the 333rd amino acid, arginine, to tryptophan. Neither of her apparently normal parents had any mutations of the TR[beta] gene. In vitro translation products of the mutant TR[beta] gene showed remarkably decreased T[sub 3]-binding activity (K[sub a], 2.1 [times] 10[sup 8] M[sup [minus]1]; normal TR[beta] K[sub a], 1.1 [times] 10[sup 10] M[sup [minus]1]). Since the molecular defect detected in a patient with PRTH is similar to that seen in subjects with generalized resistance to thyroid hormone, both types of the syndrome may represent a continuous spectrum of the same etiological defect with variable tissue resistance to thyroid hormone.

Sex Hormone Receptor Expression in the Human Vocal Fold Subunits.

Science.gov (United States)

Kirgezen, Tolga; Sunter, Ahmet Volkan; Yigit, Ozgur; Huq, Gulben Erdem

2017-07-01

The study aimed to evaluate the existence of sex hormone receptors in the subunits of vocal fold. This is a cadaver study. The androgen, estrogen, and progesterone receptors were examined in the epithelium (EP), superficial layer of the lamina propria (SLP), vocal ligament (VL), and macula flava (MF) of the vocal folds from 42 human cadavers (21 male, 21 female) by immunohistochemical methods. Their staining ratios were scored and statistically compared. The androgen receptor score was significantly higher for the MF than for the EP and SLP (P vocal fold, mostly in the MF and VLs. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Pharmacologic management of bone-related complications and bone metastases in postmenopausal women with hormone receptor-positive breast cancer

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Yardley DA

2016-05-01

Full Text Available Denise A Yardley1,2 1Sarah Cannon Research Institute, Nashville, TN, USA; 2Tennessee Oncology, Nashville, TN, USA Abstract: There is a high risk for bone loss and skeletal-related events, including bone metastases, in postmenopausal women with hormone receptor-positive breast cancer. Both the disease itself and its therapeutic treatments can negatively impact bone, resulting in decreases in bone mineral density and increases in bone loss. These negative effects on the bone can significantly impact morbidity and mortality. Effective management and minimization of bone-related complications in postmenopausal women with hormone receptor-positive breast cancer remain essential. This review discusses the current understanding of molecular and biological mechanisms involved in bone turnover and metastases, increased risk for bone-related complications from breast cancer and breast cancer therapy, and current and emerging treatment strategies for managing bone metastases and bone turnover in postmenopausal women with hormone receptor-positive breast cancer. Keywords: breast cancer, bone metastases, hormone receptor-positive, bone-related complications, interventions, management and management strategies, estrogen receptor-positive

Prostate-specific antigen and hormone receptor expression in male and female breast carcinoma

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Cohen Cynthia

2010-09-01

Full Text Available Abstract Background Prostate carcinoma is among the most common solid tumors to secondarily involve the male breast. Prostate specific antigen (PSA and prostate-specific acid phosphatase (PSAP are expressed in benign and malignant prostatic tissue, and immunohistochemical staining for these markers is often used to confirm the prostatic origin of metastatic carcinoma. PSA expression has been reported in male and female breast carcinoma and in gynecomastia, raising concerns about the utility of PSA for differentiating prostate carcinoma metastasis to the male breast from primary breast carcinoma. This study examined the frequency of PSA, PSAP, and hormone receptor expression in male breast carcinoma (MBC, female breast carcinoma (FBC, and gynecomastia. Methods Immunohistochemical staining for PSA, PSAP, AR, ER, and PR was performed on tissue microarrays representing six cases of gynecomastia, thirty MBC, and fifty-six FBC. Results PSA was positive in two of fifty-six FBC (3.7%, focally positive in one of thirty MBC (3.3%, and negative in the five examined cases of gynecomastia. PSAP expression was absent in MBC, FBC, and gynecomastia. Hormone receptor expression was similar in males and females (AR 74.1% in MBC vs. 67.9% in FBC, p = 0.62; ER 85.2% vs. 68.5%, p = 0.18; and PR 51.9% vs. 48.2%, p = 0.82. Conclusions PSA and PSAP are useful markers to distinguish primary breast carcinoma from prostate carcinoma metastatic to the male breast. Although PSA expression appeared to correlate with hormone receptor expression, the incidence of PSA expression in our population was too low to draw significant conclusions about an association between PSA expression and hormone receptor status in breast lesions.

Model of the complex of Parathyroid hormone-2 receptor and Tuberoinfundibular peptide of 39 residues

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Persson Bengt

2010-10-01

Full Text Available Abstract Background We aim to propose interactions between the parathyroid hormone-2 receptor (PTH2R and its ligand the tuberoinfundibular peptide of 39 residues (TIP39 by constructing a homology model of their complex. The two related peptides parathyroid hormone (PTH and parathyroid hormone related protein (PTHrP are compared with the complex to examine their interactions. Findings In the model, the hydrophobic N-terminus of TIP39 is buried in a hydrophobic part of the central cavity between helices 3 and 7. Comparison of the peptide sequences indicates that the main discriminator between the agonistic peptides TIP39 and PTH and the inactive PTHrP is a tryptophan-phenylalanine replacement. The model indicates that the smaller phenylalanine in PTHrP does not completely occupy the binding site of the larger tryptophan residue in the other peptides. As only TIP39 causes internalisation of the receptor and the primary difference being an aspartic acid in position 7 of TIP39 that interacts with histidine 396 in the receptor, versus isoleucine/histidine residues in the related hormones, this might be a trigger interaction for the events that cause internalisation. Conclusions A model is constructed for the complex and a trigger interaction for full agonistic activation between aspartic acid 7 of TIP39 and histidine 396 in the receptor is proposed.

Hormonally-mediated Epigenetic Changes to Steroid Receptors in the Developing Brain: Implications for Sexual Differentiation

Science.gov (United States)

Nugent, Bridget M.; Schwarz, Jaclyn M.; McCarthy, Margaret M.

2010-01-01

The establishment of sex-specific neural morphology, which underlies sex-specific behaviors, occurs during a perinatal sensitive window in which brief exposure to gonadal steroid hormones produces permanent masculinization of the brain. In the rodent, estradiol derived from testicular androgens is a principle organizational hormone. The mechanism by which transient estradiol exposure induces permanent differences in neuronal anatomy has been widely investigated, but remains elusive. Epigenetic changes, such as DNA methylation, allow environmental influences to alter long-term gene expression patterns and therefore may be a potential mediator of estradiol-induced organization of the neonatal brain. Here we review data that demonstrate sex and estradiol-induced differences in DNA methylation on the estrogen receptor α (ERα), estrogen receptor β (ERβ), and progesterone receptor (PR) promoters in sexually dimorphic brain regions across development. Contrary to the overarching view of DNA methylation as a permanent modification directly tied to gene expression, these data demonstrate that methylation patterns on steroid hormone receptors change across the life span and do not necessarily predict expression. Although further exploration into the mechanism and significance of estradiol-induced alterations in DNA methylation patterns in the neonatal brain is necessary, these results provide preliminary evidence that epigenetic alterations can occur in response to early hormone exposure and may mediate estradiol-induced organization of sex differences in the neonatal brain. PMID:20800064

The Dwarfs of Sindh: severe growth hormone (GH) deficiency caused by a mutation in the GH-releasing hormone receptor gene.

Science.gov (United States)

Baumann, G; Maheshwari, H

1997-11-01

We report the discovery of a cluster of severe familial dwarfism in two villages in the Province of Sindh in Pakistan. Dwarfism is proportionate and occurs in members of a kindred with a high degree of consanguinity. Only the last generation is affected, with the oldest dwarf being 28 years old. The mode of inheritance is autosomal recessive. Phenotype analysis and endocrine testing revealed isolated growth hormone deficiency (GHD) as the reason for growth failure. Linkage analysis for the loci of several candidate genes yielded a high lod score for the growth hormone-releasing hormone receptor (GHRH-R) locus on chromosome 7. Amplification and sequencing of the GHRH-R gene in affected subjects demonstrated an amber nonsense mutation (GAG-->TAG; Glu50-->Stop) in exon 3. The mutation, in its homozygous form, segregated 100% with the dwarf phenotype. It predicts a truncation of the GHRH-R in its extracellular domain, which is likely to result in a severely disabled or non-existent receptor protein. Subjects who are heterozygous for the mutation show mild biochemical abnormalities in the growth hormone-releasing hormone (GHRH)--growth hormone--insulin-like growth factor axis, but have only minimal or no growth retardation. The occurrence of an offspring of two dwarfed parents indicates that the GHRH-R is not necessary for fertility in either sex. We conclude that Sindh dwarfism is caused by an inactivating mutation in the GHRH-R gene, resulting in the inability to transmit a GHRH signal and consequent severe isolated GHD.

Selective Negative Allosteric Modulation Of Metabotropic Glutamate Receptors - A Structural Perspective of Ligands and Mutants

DEFF Research Database (Denmark)

Harpsøe, Kasper; Isberg, Vignir; Tehan, Benjamin G

2015-01-01

modulators. In this analysis, we make the first comprehensive structural comparison of all metabotropic glutamate receptors, placing selective negative allosteric modulators and critical mutants into the detailed context of the receptor binding sites. A better understanding of how the different m......Glu allosteric modulator binding modes relates to selective pharmacological actions will be very valuable for rational design of safer drugs....

Specific regulation of thermosensitive lipid droplet fusion by a nuclear hormone receptor pathway.

Science.gov (United States)

Li, Shiwei; Li, Qi; Kong, Yuanyuan; Wu, Shuang; Cui, Qingpo; Zhang, Mingming; Zhang, Shaobing O

2017-08-15

Nuclear receptors play important roles in regulating fat metabolism and energy production in humans. The regulatory functions and endogenous ligands of many nuclear receptors are still unidentified, however. Here, we report that CYP-37A1 (ortholog of human cytochrome P450 CYP4V2), EMB-8 (ortholog of human P450 oxidoreductase POR), and DAF-12 (homolog of human nuclear receptors VDR/LXR) constitute a hormone synthesis and nuclear receptor pathway in Caenorhabditis elegans This pathway specifically regulates the thermosensitive fusion of fat-storing lipid droplets. CYP-37A1, together with EMB-8, synthesizes a lipophilic hormone not identical to Δ7-dafachronic acid, which represses the fusion-promoting function of DAF-12. CYP-37A1 also negatively regulates thermotolerance and lifespan at high temperature in a DAF-12-dependent manner. Human CYP4V2 can substitute for CYP-37A1 in C. elegans This finding suggests the existence of a conserved CYP4V2-POR-nuclear receptor pathway that functions in converting multilocular lipid droplets to unilocular ones in human cells; misregulation of this pathway may lead to pathogenic fat storage.

Thyrotropin-luteinizing hormone/chorionic gonadotropin receptor extracellular domain chimeras as probes for thyrotropin receptor function

International Nuclear Information System (INIS)

Nagayama, Yuji; Wadsworth, H.L.; Chazenbalk, G.D.; Russo, D.; Seto, Pui; Rapoport, B.

1991-01-01

To define the sites in the extracellular domain of the human thyrotropin (TSH) receptor that are involved in TSH binding and signal transduction the authors constructed chimeric thyrotropin-luteinizing hormone/chorionic gonadotropin (TSH-LH/CG) receptors. The extracellular domain of the human TSH receptor was divided into five regions that were replaced, either singly or in various combinations, with homologous regions of the rat LH/CG receptor. The chimeric receptors were stably expressed in Chinese hamster ovary cells. The data obtained suggest that the carboxyl region of the extracellular domain (amino acid residues 261-418) and particularly the middle region (residues 171-260) play a role in signal transduction. The possibility is also raised of an interaction between the amino and carboxyl regions of the extracellular domain in the process of signal transduction. In summary, these studies suggest that the middle region and carboxyl half of the extracellular domain of the TSH receptor are involved in signal transduction and that the TSH-binding region is likely to span the entire extracellular domain, with multiple discontinuous contact sites

Expression and role of gonadotropin-releasing hormone 2 and its receptor in mammals

Science.gov (United States)

Gonadotropin-releasing hormone (GnRH1) and its receptor (GnRHR1) drive mammalian reproduction via regulation of the gonadotropins. Yet, a second form of GnRH (GnRH2) and its receptor (GnRHR2) also exist in some mammals. GnRH2 has been completely conserved throughout 500 million years of evolution, s...

Thyroid Hormone Receptor Antagonists: From Environmental Pollution to Novel Small Molecules.

Science.gov (United States)

Mackenzie, Louise S

2018-01-01

Thyroid hormone receptors (TRs) are nuclear receptors which control transcription, and thereby have effects in all cells within the body. TRs are an important regulator in many basic physiological processes including development, growth, metabolism, and cardiac function. The hyperthyroid condition results from an over production of thyroid hormones resulting in a continual stimulation of thyroid receptors which is detrimental for the patient. Therapies for hyperthyroidism are available, but there is a need for new small molecules that act as TR antagonists to treat hyperthyroidism. Many compounds exhibit TR antagonism and are considered detrimental to health. Some drugs in the clinic (most importantly, amiodarone) and environmental pollution exhibit TR antagonist properties and thus have the potential to induce hypothyroidism in some people. This chapter provides an overview of novel small molecules that have been specifically designed or screened for their TR antagonist activity as novel treatments for hyperthyroidism. While novel compounds have been identified, to date none have been developed sufficiently to enter clinical trials. Furthermore, a discussion on other sources of TR antagonists is discussed in terms of side effects of current drugs in the clinic as well as environmental pollution. © 2018 Elsevier Inc. All rights reserved.

Knockin mouse with mutant Gα11 mimics human inherited hypocalcemia and is rescued by pharmacologic inhibitors

DEFF Research Database (Denmark)

Roszko, Kelly L; Bi, Ruiye; Gorvin, Caroline M

2017-01-01

in patients with autosomal-dominant hypocalcemia type 2 (ADH2), an inherited disorder of hypocalcemia, low parathyroid hormone (PTH), and hyperphosphatemia. We have generated knockin mice harboring the point mutation GNA11 c.C178T (p.Arg60Cys) identified in ADH2 patients. The mutant mice faithfully replicated...... human ADH2. They also exhibited low bone mineral density and increased skin pigmentation. Treatment with NPS 2143, a negative allosteric modulator of the calcium-sensing receptor (CASR), increased PTH and calcium concentrations in WT and mutant mice, suggesting that the gain-of-function effect of GNA11...

Interaction between body mass index and hormone-receptor status as a prognostic factor in lymph-node-positive breast cancer.

Directory of Open Access Journals (Sweden)

Il Yong Chung

Full Text Available The aim of this study was to determine the relationship between the body mass index (BMI at a breast cancer diagnosis and various factors including the hormone-receptor, menopause, and lymph-node status, and identify if there is a specific patient subgroup for which the BMI has an effect on the breast cancer prognosis. We retrospectively analyzed the data of 8,742 patients with non-metastatic invasive breast cancer from the research database of Asan Medical Center. The overall survival (OS and breast-cancer-specific survival (BCSS outcomes were compared among BMI groups using the Kaplan-Meier method and Cox proportional-hazards regression models with an interaction term. There was a significant interaction between BMI and hormone-receptor status for the OS (P = 0.029, and BCSS (P = 0.013 in lymph-node-positive breast cancers. Obesity in hormone-receptor-positive breast cancer showed a poorer OS (adjusted hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 0.92 to 2.48 and significantly poorer BCSS (HR = 1.80, 95% CI = 1.08 to 2.99. In contrast, a high BMI in hormone-receptor-negative breast cancer revealed a better OS (HR = 0.44, 95% CI = 0.16 to 1.19 and BCSS (HR = 0.53, 95% CI = 0.19 to 1.44. Being underweight (BMI < 18.50 kg/m2 with hormone-receptor-negative breast cancer was associated with a significantly worse OS (HR = 1.98, 95% CI = 1.00-3.95 and BCSS (HR = 2.24, 95% CI = 1.12-4.47. There was no significant interaction found between the BMI and hormone-receptor status in the lymph-node-negative setting, and BMI did not interact with the menopause status in any subgroup. In conclusion, BMI interacts with the hormone-receptor status in a lymph-node-positive setting, thereby playing a role in the prognosis of breast cancer.

Analysis and functional characterization of sequence variations in ligand binding domain of thyroid hormone receptors in autism spectrum disorder (ASD) patients.

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Kalikiri, Mahesh Kumar; Mamidala, Madhu Poornima; Rao, Ananth N; Rajesh, Vidya

2017-12-01

Autism spectrum disorder (ASD) is a neuro developmental disorder, reported to be on a rise in the past two decades. Thyroid hormone-T3 plays an important role in early embryonic and central nervous system development. T3 mediates its function by binding to thyroid hormone receptors, TRα and TRβ. Alterations in T3 levels and thyroid receptor mutations have been earlier implicated in neuropsychiatric disorders and have been linked to environmental toxins. Limited reports from earlier studies have shown the effectiveness of T3 treatment with promising results in children with ASD and that the thyroid hormone levels in these children was also normal. This necessitates the need to explore the genetic variations in the components of the thyroid hormone pathway in ASD children. To achieve this objective, we performed genetic analysis of ligand binding domain of THRA and THRB receptor genes in 30 ASD subjects and in age matched controls from India. Our study for the first time reports novel single nucleotide polymorphisms in the THRA and THRB receptor genes of ASD individuals. Autism Res 2017, 10: 1919-1928. ©2017 International Society for Autism Research, Wiley Periodicals, Inc. Thyroid hormone (T3) and thyroid receptors (TRα and TRβ) are the major components of the thyroid hormone pathway. The link between thyroid pathway and neuronal development is proven in clinical medicine. Since the thyroid hormone levels in Autistic children are normal, variations in their receptors needs to be explored. To achieve this objective, changes in THRA and THRB receptor genes was studied in 30 ASD and normal children from India. The impact of some of these mutations on receptor function was also studied. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Vegetable and fruit consumption and the risk of hormone receptor-defined breast cancer in the EPIC cohort.

Science.gov (United States)

Emaus, Marleen J; Peeters, Petra H M; Bakker, Marije F; Overvad, Kim; Tjønneland, Anne; Olsen, Anja; Romieu, Isabelle; Ferrari, Pietro; Dossus, Laure; Boutron-Ruault, Marie Christine; Baglietto, Laura; Fortner, Renée T; Kaaks, Rudolf; Boeing, Heiner; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Masala, Giovanna; Pala, Valeria; Panico, Salvatore; Tumino, Rosario; Polidoro, Silvia; Skeie, Guri; Lund, Eiliv; Weiderpass, Elisabete; Quirós, J Ramón; Travier, Noémie; Sánchez, María-José; Chirlaque, Maria-Dolores; Ardanaz, Eva; Dorronsoro, Miren; Winkvist, Anna; Wennberg, Maria; Bueno-de-Mesquita, H Bas; Khaw, Kay-Tee; Travis, Ruth C; Key, Timothy J; Aune, Dagfinn; Gunter, Marc; Riboli, Elio; van Gils, Carla H

2016-01-01

The recent literature indicates that a high vegetable intake and not a high fruit intake could be associated with decreased steroid hormone receptor-negative breast cancer risk. This study aimed to investigate the association between vegetable and fruit intake and steroid hormone receptor-defined breast cancer risk. A total of 335,054 female participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort were included in this study (mean ± SD age: 50.8 ± 9.8 y). Vegetable and fruit intake was measured by country-specific questionnaires filled out at recruitment between 1992 and 2000 with the use of standardized procedures. Cox proportional hazards models were stratified by age at recruitment and study center and were adjusted for breast cancer risk factors. After a median follow-up of 11.5 y (IQR: 10.1-12.3 y), 10,197 incident invasive breast cancers were diagnosed [3479 estrogen and progesterone receptor positive (ER+PR+); 1021 ER and PR negative (ER-PR-)]. Compared with the lowest quintile, the highest quintile of vegetable intake was associated with a lower risk of overall breast cancer (HRquintile 5-quintile 1: 0.87; 95% CI: 0.80, 0.94). Although the inverse association was most apparent for ER-PR- breast cancer (ER-PR-: HRquintile 5-quintile 1: 0.74; 95% CI: 0.57, 0.96; P-trend = 0.03; ER+PR+: HRquintile 5-quintile 1: 0.91; 95% CI: 0.79, 1.05; P-trend = 0.14), the test for heterogeneity by hormone receptor status was not significant (P-heterogeneity = 0.09). Fruit intake was not significantly associated with total and hormone receptor-defined breast cancer risk. This study supports evidence that a high vegetable intake is associated with lower (mainly hormone receptor-negative) breast cancer risk. © 2016 American Society for Nutrition.

Characterization of a family of gamma-ray-induced CHO mutants demonstrates that the ldlA locus is diploid and encodes the low-density lipoprotein receptor

International Nuclear Information System (INIS)

Sege, R.D.; Kozarsky, K.F.; Krieger, M.

1986-01-01

The ldlA locus is one of four Chinese hamster ovary (CHO) cell loci which are known to be required for the synthesis of functional low-density lipoprotein (LDL) receptors. Previous studies have suggested that the ldlA locus is diploid and encodes the LDL receptor. To confirm this assignment, we have isolated a partial genomic clone of the Chinese hamster LDL receptor gene and used this and other nucleic acid and antibody probes to study a family of ldlA mutants isolated after gamma-irradiation. Our analysis suggests that there are two LDL receptor alleles in wild-type CHO cells. Each of the three mutants isolated after gamma-irradiation had detectable deletions affecting one of the two LDL receptor alleles. One of the mutants also had a disruption of the remaining allele, resulting in the synthesis of an abnormal receptor precursor which was not subject to Golgi-associated posttranslational glycoprotein processing. The correlation of changes in the expression, structure, and function of LDL receptors with deletions in the LDL receptor genes in these mutants directly demonstrated that the ldlA locus in CHO cells is diploid and encodes the LDL receptor. In addition, our analysis suggests that CHO cells in culture may contain a partial LDL receptor pseudogene

Toll-like receptor 4 mutant and null mice retain morphine-induced tolerance, hyperalgesia, and physical dependence.

Directory of Open Access Journals (Sweden)

Theresa Alexandra Mattioli

Full Text Available The innate immune system modulates opioid-induced effects within the central nervous system and one target that has received considerable attention is the toll-like receptor 4 (TLR4. Here, we examined the contribution of TLR4 in the development of morphine tolerance, hyperalgesia, and physical dependence in two inbred mouse strains: C3H/HeJ mice which have a dominant negative point mutation in the Tlr4 gene rendering the receptor non-functional, and B10ScNJ mice which are TLR4 null mutants. We found that neither acute antinociceptive response to a single dose of morphine, nor the development of analgesic tolerance to repeated morphine treatment, was affected by TLR4 genotype. Likewise, opioid induced hyperalgesia and opioid physical dependence (assessed by naloxone precipitated withdrawal were not altered in TLR4 mutant or null mice. We also examined the behavioural consequence of two stereoisomers of naloxone: (- naloxone, an opioid receptor antagonist, and (+ naloxone, a purported antagonist of TLR4. Both stereoisomers of naloxone suppressed opioid induced hyperalgesia in wild-type control, TLR4 mutant, and TLR4 null mice. Collectively, our data suggest that TLR4 is not required for opioid-induced analgesic tolerance, hyperalgesia, or physical dependence.

Shaping policy: the Canadian Cancer Society and the Hormone Receptor Testing Inquiry.

Science.gov (United States)

Mathews, M; Newbury, J; Housser, E M

2011-08-01

In 2007, the Government of Newfoundland and Labrador established the Commission of Inquiry on Hormone Receptor Testing to examine problems with estrogen and progesterone hormone receptor tests conducted in the province between 1997 and 2005. Using the Inquiry as a case study, we examine the knowledge transfer activities used by the Canadian Cancer Society - Newfoundland and Labrador Division (CCS-NL) to shape policy and improve cancer control in the province. CCS-NL established a panel to advise its legal counsel and asked academic researchers to prepare papers to submit to the Commission. CCS-NL also interviewed patients to better inform its legal arguments, used its province-wide networks to raise awareness of the Inquiry, and provided a toll-free number that people could call. It also provided basic information, resources, and contact information for people who were affected by the flawed hormone receptor tests. The effectiveness of CCS-NL's activities is reflected by the inclusion of its key messages in the Commission's recommendations, and the investment in cancer care following the Inquiry. The success of the CCS-NL knowledge transfer efforts stemmed from its reputation as an advocate for cancer patients and its long-standing relationship with researchers, especially at the local level. The case illustrates real-world application of knowledge transfer practices in the development of public policy, and describes how community-based non-government organizations can identify and draw attention to important issues that otherwise might not have been addressed.

Pharmacological characterization of homobaclofen on wild type and mutant GABA(B)1b receptors coexpressed with the GABA(B)2 receptor

DEFF Research Database (Denmark)

Jensen, Anders A.; Madsen, Bo E.; Krogsgaard-Larsen, P

2001-01-01

homogenate and in an assay of electrically induced contractions of guinea pig ileum. The results from the two tissues did, however, not correlate very well, and in order to further investigate these discrepancies, we have pharmacologically characterized these enantiomers on recombinant wild type and mutant...... rat GABA(B)1b receptors coexpressed with rat GABA(B)2 receptors. The results from this study correlate nicely with the binding data from rat brain. (R)-Homobaclofen was shown to act like (R)-baclofen albeit with 20-fold less potency, and (S)-homobaclofen was inactive on the receptor. The discrepancies...

Selective thyroid hormone receptor modulators

Directory of Open Access Journals (Sweden)

Girish Raparti

2013-01-01

Full Text Available Thyroid hormone (TH is known to have many beneficial effects on vital organs, but its extrapolation to be used therapeutically has been restricted by the fact that it does have concurrent adverse effects. Recent finding of various thyroid hormone receptors (TR isoforms and their differential pattern of tissue distribution has regained interest in possible use of TH analogues in therapeutics. These findings were followed by search of compounds with isoform-specific or tissue-specific action on TR. Studying the structure-activity relationship of TR led to the development of compounds like GC1 and KB141, which preferentially act on the β1 isoform of TR. More recently, eprotirome was developed and has been studied in humans. It has shown to be effective in dyslipidemia by the lipid-lowering action of TH in the liver and also in obesity. Another compound, 3,5-diiodothyropropionic acid (DITPA, binds to both α- and β-type TRs with relatively low affinity and has been shown to be effective in heart failure (HF. In postinfarction models of HF and in a pilot clinical study, DITPA increased cardiac performance without affecting the heart rate. TR antagonists like NH3 can be used in thyrotoxicosis and cardiac arrhythmias. However, further larger clinical trials on some of these promising compounds and development of newer compounds with increased selectivity is required to achieve higher precision of action and avoid adverse effects seen with TH.

Breast cancer with Her-22 hormone receptor-positive neu: primary systemic treatment, sentinel node biopsy and hormone

International Nuclear Information System (INIS)

Lopez C, Nayara; Sanchez M, Jose Ignacio; De Santiago G, Javier

2013-01-01

Neoadjuvant chemotherapy is an interesting option in the therapy of some breast cancer cases. Cases in which the timing for sentinel lymph node biopsy is controversial. Co-expression of estrogen receptors and Her2/neu (cc-erbB-2) in breast cancer may imply hormone resistance, especially to tamoxifen. We present a clinic case with co-expression of estrogen receptors and Her2/neu that was treated with neoadjuvant chemotherapy and previous sentinel lymph node biopsy followed by breast tumorectomy with axillar lympha- denectomy, radiotherapy and hormonotherapy with letrozol, geserelina and trastuzumab. A good treatment response as found

Differences in signal activation by LH and hCG are mediated by the LH/CG receptor`s extracellular hinge region

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Paul eGrzesik

2015-09-01

Full Text Available The human lutropin/choriogonadotropin receptor (LHCGR can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG - secreted by the placenta, and lutropin (LH - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich repeat domain (LRRD, as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting mutations. These helix preserving modifications showed no effect on hormone induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10 deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region s. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge region

Expression of the growth hormone receptor gene in insulin producing cells

DEFF Research Database (Denmark)

Møldrup, Annette; Billestrup, N; Nielsen, Jens Høiriis

1990-01-01

Growth hormone (GH) plays a dual role in glucose homeostasis. On the one hand, it exerts an insulin antagonistic effect on the peripheral tissue, on the other hand, it stimulates insulin biosynthesis and beta-cell proliferation. The expression of GH-receptors on the rat insulinoma cell line RIN-5...

Cytoplasmic sequences of the growth hormone receptor necessary for signal transduction

DEFF Research Database (Denmark)

Goujon, L; Allevato, G; Simonin, G

1994-01-01

To study structure-function relationships of the growth hormone (GH) receptor (GHR), two functional systems have been developed. CHO cells were transiently cotransfected with the cDNA encoding the full-length rat GHR and with a construct consisting of the 5' flanking region of one of two GH...

Mutant with diphtheria toxin receptor and acidification function but defective in entry of toxin

International Nuclear Information System (INIS)

Kohno, Kenji; Hayes, H.; Mekada, Eisuke; Uchida, Tsuyoshi

1987-01-01

A mutant of Chinese hamster ovary cells, GE1, that is highly resistant to diphtheria toxin was isolated. The mutant contains 50% ADP-ribosylatable elongation factor 2, but its protein synthesis was not inhibited by the toxin even at concentrations above 100 μg/ml. 125 I-labeled diphtheria toxin was associated with GE1 cells as well as with the parent cells but did not block protein synthesis of GE1 cells even when the cells were exposed to low pH in the presence or absence of NH 4 Cl. The infections of GE1 cells and the parent cells by vesicular stomatitis virus were similar. GE1 cells were cross-resistant to Pseudomonas aeruginosa exotoxin A and so were about 1,000 times more resistant to this toxin than the parent cells. Hybrids of GE1 cells and the parent cells or mutant cells lacking a functional receptor were more sensitive to diphtheria toxin than GE1 cells. These results suggest that entry of diphtheria toxin into cells requires a cellular factor(s) in addition to those involved in receptor function and acidification of endosomes and that GE1 cells do not express this cellular factor. This character is recessive in GE1 cells

Nuclear Import and Export of the Thyroid Hormone Receptor.

Science.gov (United States)

Zhang, Jibo; Roggero, Vincent R; Allison, Lizabeth A

2018-01-01

The thyroid hormone receptors, TRα1 and TRβ1, are members of the nuclear receptor superfamily that forms one of the most abundant classes of transcription factors in multicellular organisms. Although primarily localized to the nucleus, TRα1 and TRβ1 shuttle rapidly between the nucleus and cytoplasm. The fine balance between nuclear import and export of TRs has emerged as a critical control point for modulating thyroid hormone-responsive gene expression. Mutagenesis studies have defined two nuclear localization signal (NLS) motifs that direct nuclear import of TRα1: NLS-1 in the hinge domain and NLS-2 in the N-terminal A/B domain. Three nuclear export signal (NES) motifs reside in the ligand-binding domain. A combined approach of shRNA-mediated knockdown and coimmunoprecipitation assays revealed that nuclear entry of TRα1 is facilitated by importin 7, likely through interactions with NLS-2, and importin β1 and the adapter importin α1 interacting with both NLS-1 and NLS-2. Interestingly, TRβ1 lacks NLS-2 and nuclear import depends solely on the importin α1/β1 heterodimer. Heterokaryon and fluorescence recovery after photobleaching shuttling assays identified multiple exportins that play a role in nuclear export of TRα1, including CRM1 (exportin 1), and exportins 4, 5, and 7. Even single amino acid changes in TRs dramatically alter their intracellular distribution patterns. We conclude that mutations within NLS and NES motifs affect nuclear shuttling activity, and propose that TR mislocalization contributes to the development of some types of cancer and Resistance to Thyroid Hormone syndrome. © 2018 Elsevier Inc. All rights reserved.

Molecular characterization of thyroid hormone receptors from the leopard gecko, and their differential expression in the skin.

Science.gov (United States)

Kanaho, Yoh-Ichiro; Endo, Daisuke; Park, Min Kyun

2006-06-01

Thyroid hormones (THs) play crucial roles in various developmental and physiological processes in vertebrates, including squamate reptiles. The effect of THs on shedding frequency is interesting in Squamata, since the effects on lizards are quite the reverse of those in snakes: injection of thyroxine increases shedding frequency in lizards, but decreases it in snakes. However, the mechanism underlying this differential effect remains unclear. To facilitate the investigation of the molecular mechanism of the physiological functions of THs in Squamata, their two specific receptor (TRalpha and beta) cDNAs, which are members of the nuclear hormone receptor superfamily, were cloned from a lizard, the leopard gecko, Eublepharis macularius. This is the first molecular cloning of thyroid hormone receptors (TRs) from reptiles. The deduced amino acid sequences showed high identity with those of other species, especially in the C and E/F domains, which are characteristic domains in nuclear hormone receptors. Expression analysis revealed that TRs were widely expressed in many tissues and organs, as in other animals. To analyze their role in the skin, temporal expression analysis was performed by RT-PCR, revealing that the two TRs had opposing expression patterns: TRalpha was expressed more strongly after than before skin shedding, whereas TRbeta was expressed more strongly before than after skin shedding. This provides good evidence that THs play important roles in the skin, and that the roles of their two receptor isoforms are distinct from each other.

Social information changes stress hormone receptor expression in the songbird brain.

Science.gov (United States)

Cornelius, Jamie M; Perreau, Gillian; Bishop, Valerie R; Krause, Jesse S; Smith, Rachael; Hahn, Thomas P; Meddle, Simone L

2018-01-01

Social information is used by many vertebrate taxa to inform decision-making, including resource-mediated movements, yet the mechanisms whereby social information is integrated physiologically to affect such decisions remain unknown. Social information is known to influence the physiological response to food reduction in captive songbirds. Red crossbills (Loxia curvirostra) that were food reduced for several days showed significant elevations in circulating corticosterone (a "stress" hormone often responsive to food limitation) only if their neighbors were similarly food restricted. Physiological responses to glucocorticoid hormones are enacted through two receptors that may be expressed differentially in target tissues. Therefore, we investigated the influence of social information on the expression of the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) mRNA in captive red crossbill brains. Although the role of MR and GR in the response to social information may be highly complex, we specifically predicted social information from food-restricted individuals would reduce MR and GR expression in two brain regions known to regulate hypothalamic-pituitary-adrenal (HPA) activity - given that reduced receptor expression may lessen the efficacy of negative feedback and release inhibitory tone on the HPA. Our results support these predictions - offering one potential mechanism whereby social cues could increase or sustain HPA-activity during stress. The data further suggest different mechanisms by which metabolic stress versus social information influence HPA activity and behavioral outcomes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Down-regulation of parathyroid hormone (PTH) receptors in cultured bone cells is associated with agonist-specific intracellular processing of PTH-receptor complexes.

Science.gov (United States)

Teitelbaum, A P; Silve, C M; Nyiredy, K O; Arnaud, C D

1986-02-01

Exposure of cultured embryonic chicken bone cells to the PTH agonists bovine (b) PTH-(1-34) and [8Nle, 18Nle, 34Tyr]bPTH-(1-34)amide [bPTH-(1-34)A] reduces the subsequent cAMP response to the hormone and decreases the specific binding of 125I-labeled PTH to these cultures. To determine whether PTH receptor down-regulation in cultured bone cells is mediated by cellular internalization of PTH-receptor complexes, we measured the uptake of [125I]bPTH-(1-34) into an acid-resistant compartment. Uptake of radioactivity into this compartment was inhibited by incubating cells at 4 C with phenylarsineoxide and unlabeled bPTH-(1-34). Tracer uptake into the acid-resistant compartment at any time was directly proportional to total cell binding at 22 C. Thus, it is likely that PTH-receptor complexes are internalized by bone cells. This mechanism may explain the loss of cell surface receptors after PTH pretreatment. To determine whether internalized PTH-receptor complexes are reinserted into the plasma membrane, we measured PTH binding and PTH stimulation of cAMP production after cells were exposed to monensin, a known inhibitor of receptor recycling. Monensin (25 microM) had no effect on PTH receptor number or affinity and did not alter PTH-stimulated cAMP accumulation. However, monensin (25 microM) incubated with cells pretreated with various concentrations of bPTH-(1-34) for 1 h potentiated the effect of the hormone to reduce subsequent [125I]bPTH-(1-34) binding and PTH-stimulated cAMP accumulation by more than 2 orders of magnitude. Chloroquine also potentiated PTH-induced down-regulation of PTH receptors. By contrast, neither agent influenced PTH binding or PTH-stimulated cAMP production in cells pretreated with the antagonist bPTH-(3-34)A. Thus, monensin potentiated PTH receptor loss only in cells pretreated with PTH agonists, indicating that antagonist-occupied receptors may be processed differently from agonist-occupied receptors in bone cells. The data further suggest

Rescue of a pathogenic mutant human glucagon receptor by pharmacological chaperones.

Science.gov (United States)

Yu, Run; Chen, Chun-Rong; Liu, Xiaohong; Kodra, János T

2012-10-01

We have previously demonstrated that a homozygous inactivating P86S mutation of the glucagon receptor (GCGR) causes a novel human disease of hyperglucagonemia, pancreatic α-cell hyperplasia, and pancreatic neuroendocrine tumors (Mahvash disease). The mechanisms for the decreased activity of the P86S mutant (P86S) are abnormal receptor localization to the endoplasmic reticulum (ER) and defective interaction with glucagon. To search for targeted therapies for Mahvash disease, we examined whether P86S can be trafficked to the plasma membrane by pharmacological chaperones and whether novel glucagon analogs restore effective receptor interaction. We used enhanced green fluorescent protein-tagged P86S stably expressed in HEK 293 cells to allow fluorescence imaging and western blotting and molecular modeling to design novel glucagon analogs in which alanine 19 was replaced with serine or asparagine. Incubation at 27 °C largely restored normal plasma membrane localization and normal processing of P86S but osmotic chaperones had no effects. The ER stressors thapsigargin and curcumin partially rescued P86S. The lipophilic GCGR antagonist L-168,049 also partially rescued P86S, so did Cpd 13 and 15 to a smaller degree. The rescued P86S led to more glucagon-stimulated cAMP production and was internalized by glucagon. Compared with the native glucagon, the novel glucagon analogs failed to stimulate more cAMP production by P86S. We conclude that the mutant GCGR is partially rescued by several pharmacological chaperones and our data provide proof-of-principle evidence that Mahvash disease can be potentially treated with pharmacological chaperones. The novel glucagon analogs, however, failed to interact with P86S more effectively.

Vitamin D receptor displays DNA binding and transactivation as a heterodimer with the retinoid X receptor, but not with the thyroid hormone receptor.

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Thompson, P D; Hsieh, J C; Whitfield, G K; Haussler, C A; Jurutka, P W; Galligan, M A; Tillman, J B; Spindler, S R; Haussler, M R

1999-12-01

The vitamin D receptor (VDR) is a transcription factor believed to function as a heterodimer with the retinoid X receptor (RXR). However, it was reported [Schräder et al., 1994] that, on putative vitamin D response elements (VDREs) within the rat 9k and mouse 28k calcium binding protein genes (rCaBP 9k and mCaBP 28k), VDR and thyroid hormone receptor (TR) form heterodimers that transactivate in response to both 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and triiodothyronine (T(3)). We, therefore, examined associations of these receptors on the putative rCaBP 9k and mCaBP 28k VDREs, as well as on established VDREs from the rat osteocalcin (rOC) and mouse osteopontin (mOP) genes, plus the thyroid hormone response element (TRE) from the rat myosin heavy chain (rMHC) gene. In gel mobility shift assays, we found no evidence for VDR-TR heterodimer interaction with any tested element. Further, employing these hormone response elements linked to reporter genes in transfected cells, VDR and TR mediated responses to their cognate ligands only from the rOC/mOP and rMHC elements, respectively, while the CaBP elements were unresponsive to any combination of ligand(s). Utilizing the rOC and mOP VDREs, two distinct repressive actions of TR on VDR-mediated signaling were demonstrated: a T(3)-independent action, presumably via direct TR-RXR competition for DNA binding, and a T(3)-dependent repression, likely by diversion of limiting RXR from VDR-RXR toward the formation of TR-RXR heterodimers. The relative importance of these two mechanisms differed in a response element-specific manner. These results may provide a partial explanation for the observed association between hyperthyroidism and bone demineralization/osteoporosis. Copyright 1999 Wiley-Liss, Inc.

Flow cytometric measurement of DNA level and steroid hormone receptor assay in breast cancer

International Nuclear Information System (INIS)

Zubrikhina, G.N.; Kuz'mina, Eh.V.; Bassalyk, L.S.; Murav'eva, N.I.

1989-01-01

DNA level measured by flow cytometry and estrogen and progesteron receptors assayed in tissue samples obtained from 85 malignant and 16 benign lesions of the breast. All the benign tumors revealed 2c DNA content and most of them were receptor-negative, while 74.1% of breast carcinomas displayed aneuploidy. Three patients (3.5%) had two lines of aneuploid cells. Many aneuploid tumors were receptor-negative. Preoperative radiation treatmet (14-20 Gy) did not significantly influence the level of steroid hormone receptors in tumors. Estrogen receptor level was higher in menopausal patients than in premenopausal ones

THYROID HORMONE RECEPTOR BETA GENE MUTATION (P453A) IN A TURKISH FAMILY PRODUCING RESISTANCE TO THYROID HORMONE

Science.gov (United States)

Bayraktaroglu, Taner; Noel, Janet; Mukaddes, Nahit Motavalli; Refetoff, Samuel

2018-01-01

Two members of a Turkish family, a mother and son, had thyroid function tests suggestive of resistance to thyroid hormone (RTH). The clinical presentation was, however, different. The mother (proposita) had palpitation, weakness, tiredness, nervousness, dry mouth and was misdiagnosed as having multinodular toxic goiter which was treated with antithyroid drugs and partial thyroidectomy. Her younger son had attention deficit hyperactivity disorder and primary encopresis, but normal intellectual quotient. Both had elevated serum iodothyronine levels with nonsuppressed thyrotropin. A mutation in one allele of the thyroid hormone receptor beta gene (P453A) was identified, providing a genetic confirmation for the diagnosis of RTH. PMID:18561095

Hepatic receptors for homologous growth hormone in the eel

International Nuclear Information System (INIS)

Hirano, T.

1991-01-01

The specific binding of 125I-labeled eel growth hormone (eGH) to liver membranes of the eel was examined. The specific binding to the 10,000g pellet was greater than that to the 600g pellet. The specific binding was linear up to about 100 mg fresh tissue, and was saturable with increasing amounts of membrane. The specific binding was pH-, temperature-, and time-dependent, with the optimum pH at 7.4, and greater specific binding was obtained at 15 and 25 degrees than at 35 degrees. Scatchard analysis of liver binding gave an association constant of 1.1 x 10(9) M-1 and a capacity of 105 fmol/mg protein. The receptor preparation was highly specific for GHs. Natural and recombinant eel GHs as well as recombinant salmon GH competed equally with 125I-eGH for the receptor sites of the 10,000g liver membrane. Ovine GH was more potent in displacing the labeled eGH than the homologous eel hormone. Tilapia GH and ovine prolactin (PRL) were needed in greater amounts (40 times) than eGH to displace the labeled eGH. Salmon and tilapia PRLs were still less potent (500 times) than eGH. There was no displacement with eel PRL. No significant change in the specific binding was seen 1 week after hypophysectomy, whereas injection of eGH into the hypophysectomized eel caused a significant reduction after 24 hr. The binding to the membrane fractions from gills, kidney, muscle, intestine, and brain was low and exclusively nonspecific, indicating the presence of specific GH receptors predominantly in the liver

Growth Hormone Receptor Signaling Pathways and its Negative Regulation by SOCS2

DEFF Research Database (Denmark)

Fernández Pérez, Leandro; Flores-Morales, Amilcar; Guerra, Borja

2016-01-01

Growth hormone (GH) is a critical regulator of linear body growth during childhood but continues to have important metabolic actions throughout life. The GH receptor (GHR) is ubiquitously expressed, and deficiency of GHR signaling causes a dramatic impact on normal physiology during somatic devel...

UV filters induce transcriptional changes of different hormonal receptors in Chironomus riparius embryos and larvae.

Science.gov (United States)

Ozáez, Irene; Aquilino, Mónica; Morcillo, Gloria; Martínez-Guitarte, José-Luis

2016-07-01

Organic ultraviolet (UV) filters are emerging contaminants that are ubiquitous in fresh and marine aquatic systems due to their extensive use in cosmetics, plastics, paints, textiles, and many other industrial products. The estrogenic effects of organic UV filters have been long demonstrated in vertebrates, and other hormonal activities may be altered, according to more recent reports. The impact of UV filters on the endocrine system of invertebrates is largely unknown. We have previously reported that some UV filters may affect ecdysone-related genes in the aquatic insect Chironomus riparius, an ecotoxicologically important model organism. To further analyze other possible effects on endocrine pathways, we first characterized four pivotal genes related with hormonal pathways in insects; thereafter, these genes were assessed for alterations in transcriptional activity after exposure to 4-methylbenzylidene camphor (4MBC) or benzophenone-3 (BP-3), two extensively used sunscreens. We found that both chemicals disturbed the expression of all four genes analyzed: hormonal receptor 38 (HR38), methoprene-tolerant (Met), membrane-associate progesterone receptor (MAPR) and insulin-like receptor (INSR), measured by changes in mRNA levels by real-time PCR. An upregulatory effect at the genomic level was detected in different developmental stages. Interestingly, embryos appeared to be more sensitive to the action of the UV filters than larvae. Our results suggest that the risk of disruption through different endocrine routes is not negligible, considering the significant effects of UV filters on key hormonal receptor and regulatory genes. Further effort is needed to develop environmental risk assessment studies on these pollutants, particularly for aquatic invertebrate model organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differences between lutropin-mediated and choriogonadotropin-mediated receptor activation.

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Grzesik, Paul; Teichmann, Anke; Furkert, Jens; Rutz, Claudia; Wiesner, Burkhard; Kleinau, Gunnar; Schülein, Ralf; Gromoll, Jörg; Krause, Gerd

2014-03-01

The human lutropin/choriogonadotropin receptor (hLHR) for the gonadotropic hormones human luteinizing hormone (hLH; lutropin) and human choriogonadotropin (hCG) is crucial for normal sexual development and fertility. We aimed to unravel differences between the two hLHR hormones in molecular activation mechanisms at hLHR. We utilized a specific hLHR variant that lacks exon 10 (hLHR-delExon10), which maintains full cAMP signaling by hCG, but decreases hLH-induced receptor signaling, resulting in a pathogenic phenotype. Exon 10 encodes 27 amino acids within the hinge region, which is an extracellular segment that is important for signaling and hormone interaction. Initially, we assumed that the lack of exon 10 might disturb intermolecular trans-activation of hLH, a mechanism that has been reported for hCG at hLHR. Coexpression of signaling-deficient hLHR and binding-deficient hLHR can be used to examine the mechanisms of receptor signaling, in particular intermolecular cooperation and intramolecular cis-activation. Therefore, hLHR-delExon10 was combined with the hLHR Lys605→Glu mutant, in which signaling is abolished, and the hLHR mutant Cys131→Arg, in which binding is deficient. We found that hCG signaling was partially rescued, indicating trans-activation. However, the hLH signal could not be restored via forced trans-activation with any construct. Fluorescence cross-correlation spectroscopy detected oligomerization in all combinations, indicating that these functional differences cannot be explained by monomerization of hLHR-delExon10. Thus, our data demonstrate not only that the different behavior of hLH at hLHR-delExon10 is unlikely to be related to modified intermolecular receptor activation, but also that hLH may exclusively stimulate the targeted hLHR by cis-activation, whereas hCG is also capable of inducing trans-activation. © 2014 FEBS.

Receptors of Hypothalamic-Pituitary-Ovarian-Axis Hormone in Uterine Myomas

Directory of Open Access Journals (Sweden)

Danuta Plewka

2014-01-01

Full Text Available In this study the expression of GnRH, FSH, LH, ER-α, ER-β, and PR receptors was examined in uterine myomas of women in reproductive and perimenopausal age. In cases of GnRH and tropic hormones a membranous and cytoplasmic immunohistochemical reaction was detected, in cases of ER-α and PR the reaction was located in cell nucleus, and in the case of ER-β it manifested also a cytoplasmic location. In some of the examined cases the expression was detected in endometrium, myocytes, and endothelium of blood vessels, in uterine glands and myoma cells. In myometrium the level of GnRH and LH receptors increases with age, whereas the level of progesterone and both estrogen receptors decreases. In myomas of women in reproductive age, independently of their size, expression of GnRH, FSH, and LH receptors was more pronounced than in myometrium. In women of perimenopausal age, independently of myoma size, expression of LH and estrogen α receptors was higher while expression of GnRH receptors was lower than in myometrium. FSH receptor expression was not observed. Expression of estrogen receptor β was not affected by age of the woman or size of myoma. Analysis of obtained results indicates on existing in small myomas local feedback axis between GnRH-LH-progesterone.

Machine learning approaches to decipher hormone and HER2 receptor status phenotypes in breast cancer.

Science.gov (United States)

Adabor, Emmanuel S; Acquaah-Mensah, George K

2017-10-16

Breast cancer prognosis and administration of therapies are aided by knowledge of hormonal and HER2 receptor status. Breast cancer lacking estrogen receptors, progesterone receptors and HER2 receptors are difficult to treat. Regarding large data repositories such as The Cancer Genome Atlas, available wet-lab methods for establishing the presence of these receptors do not always conclusively cover all available samples. To this end, we introduce median-supplement methods to identify hormonal and HER2 receptor status phenotypes of breast cancer patients using gene expression profiles. In these approaches, supplementary instances based on median patient gene expression are introduced to balance a training set from which we build simple models to identify the receptor expression status of patients. In addition, for the purpose of benchmarking, we examine major machine learning approaches that are also applicable to the problem of finding receptor status in breast cancer. We show that our methods are robust and have high sensitivity with extremely low false-positive rates compared with the well-established methods. A successful application of these methods will permit the simultaneous study of large collections of samples of breast cancer patients as well as save time and cost while standardizing interpretation of outcomes of such studies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular cloning and functional characterization of the diapause hormone receptor in the corn earworm Helicoverpa zea

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The diapause hormone (DH) in the heliothine moth has shown its activity in termination of pupal diapause, while the orthology in the silkworm is known to induce embryonic diapause. In the current study, we cloned the diapause hormone receptor from the corn earworm Helicoverpa zea (HzDHr) and tested ...

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

International Nuclear Information System (INIS)

Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus

Gender and the use of hormonal contraception in women are not associated with cerebral cortical 5-HT 2A receptor binding

DEFF Research Database (Denmark)

Frokjaer, V G; Erritzoe, D; Madsen, J

2009-01-01

to frontolimbic 5-HT(2A) receptor binding and to be more pronounced in women, again, the effect of gender was not significant (P=0.42, n=127). Also, the use of hormonal contraception (n=14) within the group of pre-menopausal women (total n=29) was not associated with cortical 5-HT(2A) receptor binding (P=0.......31). In conclusion, neither gender, nor the use of hormonal contraception in premenopausal women was associated with cortical 5-HT(2A) receptor binding....... binding it is not clear if gender or use of hormonal contraception exhibits associations with 5-HT(2A) receptor binding. We found no significant effect of gender on cortical 5-HT(2A) receptor binding (P=0.15, n=132). When adjusting for the personality trait neuroticism, known to be positively correlated...

Crystallization and preliminary X-ray crystallographic analysis of the receptor-uncoupled mutant of Gαi1

International Nuclear Information System (INIS)

Morikawa, Tomohito; Muroya, Ayumu; Nakajima, Yoshitaka; Tanaka, Takeshi; Hirai, Keiko; Sugio, Shigetoshi; Wakamatsu, Kaori; Kohno, Toshiyuki

2007-01-01

The K349P mutant of Gα i1 , which is unable to couple to G-protein-coupled receptors, has been crystallized and analyzed. The same crystallization conditions were applicable irrespective of the identity of the bound nucleotide or of the presence of the mutation. In order to understand the molecular mechanisms by which G-protein-coupled receptors (GPCRs) activate G proteins, the K349P mutant of Gα i1 (K349P), which is unable to couple to the muscarinic acetylcholine receptor, was prepared and its crystals were grown along with those of wild-type Gα i1 protein (WT). The two proteins were crystallized under almost identical conditions, thus enabling a detailed structural comparison. The crystallization conditions performed well irrespective of the identity of the bound nucleotide (GDP or GTPγS) and the crystals diffracted to resolutions of 2.2 Å (WT·GDP), 2.8 Å (WT·GTPγS), 2.6 Å (K349P·GDP) and 3.2 Å (K349P·GTPγS)

The Arabidopsis cax1 mutant exhibits impaired ion homeostasis, development, and hormonal responses and reveals interplay among vacuolar transporters.

Science.gov (United States)

Cheng, Ning-Hui; Pittman, Jon K; Barkla, Bronwyn J; Shigaki, Toshiro; Hirschi, Kendal D

2003-02-01

The Arabidopsis Ca(2+)/H(+) transporter CAX1 (Cation Exchanger1) may be an important regulator of intracellular Ca(2+) levels. Here, we describe the preliminary localization of CAX1 to the tonoplast and the molecular and biochemical characterization of cax1 mutants. We show that these mutants exhibit a 50% reduction in tonoplast Ca(2+)/H(+) antiport activity, a 40% reduction in tonoplast V-type H(+)-translocating ATPase activity, a 36% increase in tonoplast Ca(2+)-ATPase activity, and increased expression of the putative vacuolar Ca(2+)/H(+) antiporters CAX3 and CAX4. Enhanced growth was displayed by the cax1 lines under Mn(2+) and Mg(2+) stress conditions. The mutants exhibited altered plant development, perturbed hormone sensitivities, and altered expression of an auxin-regulated promoter-reporter gene fusion. We propose that CAX1 regulates myriad plant processes and discuss the observed phenotypes with regard to the compensatory alterations in other transporters.

The Arabidopsis cax1 Mutant Exhibits Impaired Ion Homeostasis, Development, and Hormonal Responses and Reveals Interplay among Vacuolar Transporters

Science.gov (United States)

Cheng, Ning-Hui; Pittman, Jon K.; Barkla, Bronwyn J.; Shigaki, Toshiro; Hirschi, Kendal D.

2003-01-01

The Arabidopsis Ca2+/H+ transporter CAX1 (Cation Exchanger1) may be an important regulator of intracellular Ca2+ levels. Here, we describe the preliminary localization of CAX1 to the tonoplast and the molecular and biochemical characterization of cax1 mutants. We show that these mutants exhibit a 50% reduction in tonoplast Ca2+/H+ antiport activity, a 40% reduction in tonoplast V-type H+-translocating ATPase activity, a 36% increase in tonoplast Ca2+-ATPase activity, and increased expression of the putative vacuolar Ca2+/H+ antiporters CAX3 and CAX4. Enhanced growth was displayed by the cax1 lines under Mn2+ and Mg2+ stress conditions. The mutants exhibited altered plant development, perturbed hormone sensitivities, and altered expression of an auxin-regulated promoter-reporter gene fusion. We propose that CAX1 regulates myriad plant processes and discuss the observed phenotypes with regard to the compensatory alterations in other transporters. PMID:12566577

Molecular Cloning, Genomic Organization and Developmental Regulation of a Novel Receptor from Drosophila melanogaster Structurally Related to Gonadotropin-Releasing Hormone Receptors from Vertebrates

DEFF Research Database (Denmark)

Hauser, Frank; Søndergaard, Leif; Grimmelikhuijzen, Cornelis J.P.

1998-01-01

After screening the data base of the BerkeleyDrosophilaGenome Project with a sequence coding for the transmembrane region of a G protein-coupled receptor, we found thatDrosophilamight contain a gene coding for a receptor that is structurally related to the Gonadotropin-Releasing Hormone (GnRH) re...

Gene specific actions of thyroid hormone receptor subtypes.

Directory of Open Access Journals (Sweden)

Jean Z Lin

Full Text Available There are two homologous thyroid hormone (TH receptors (TRs α and β, which are members of the nuclear hormone receptor (NR family. While TRs regulate different processes in vivo and other highly related NRs regulate distinct gene sets, initial studies of TR action revealed near complete overlaps in their actions at the level of individual genes. Here, we assessed the extent that TRα and TRβ differ in target gene regulation by comparing effects of equal levels of stably expressed exogenous TRs +/- T(3 in two cell backgrounds (HepG2 and HeLa. We find that hundreds of genes respond to T(3 or to unliganded TRs in both cell types, but were not able to detect verifiable examples of completely TR subtype-specific gene regulation. TR actions are, however, far from identical and we detect TR subtype-specific effects on global T(3 response kinetics in HepG2 cells and many examples of TR subtype specificity at the level of individual genes, including effects on magnitude of response to TR +/- T(3, TR regulation patterns and T(3 dose response. Cycloheximide (CHX treatment confirms that at least some differential effects involve verifiable direct TR target genes. TR subtype/gene-specific effects emerge in the context of widespread variation in target gene response and we suggest that gene-selective effects on mechanism of TR action highlight differences in TR subtype function that emerge in the environment of specific genes. We propose that differential TR actions could influence physiologic and pharmacologic responses to THs and selective TR modulators (STRMs.

Receptors and effects of gut hormones in three osteoblastic cell lines

Directory of Open Access Journals (Sweden)

Wilson Peter JM

2011-07-01

Full Text Available Abstract Background In recent years the interest on the relationship of gut hormones to bone processes has increased and represents one of the most interesting aspects in skeletal research. The proportion of bone mass to soft tissue is a relationship that seems to be controlled by delicate and subtle regulations that imply "cross-talks" between the nutrient intake and tissues like fat. Thus, recognition of the mechanisms that integrate a gastrointestinal-fat-bone axis and its application to several aspects of human health is vital for improving treatments related to bone diseases. This work analysed the effects of gut hormones in cell cultures of three osteoblastic cell lines which represent different stages in osteoblastic development. Also, this is the first time that there is a report on the direct effects of glucagon-like peptide 2, and obestatin on osteoblast-like cells. Methods mRNA expression levels of five gut hormone receptors (glucose-dependent insulinotropic peptide [GIP], glucagon-like peptide 1 [GLP-1], glucagon-like peptide 2 [GLP-2], ghrelin [GHR] and obestatin [OB] were analysed in three osteoblastic cell lines (Saos-2, TE-85 and MG-63 showing different stages of osteoblast development using reverse transcription and real time polymerase chain reaction. The responses to the gut peptides were studied using assays for cell viability, and biochemical bone markers: alkaline phosphatase (ALP, procollagen type 1 amino-terminal propeptides (P1NP, and osteocalcin production. Results The gut hormone receptor mRNA displayed the highest levels for GIP in Saos-2 and the lowest levels in MG-63, whereas GHR and GPR39 (the putative obestatin receptor expression was higher in TE-85 and MG-63 and lower in Saos-2. GLP-1 and GLP-2 were expressed only in MG-63 and TE-85. Treatment of gut hormones to cell lines showed differential responses: higher levels in cell viability in Saos-2 after GIP, in TE-85 and MG-63 after GLP-1, GLP-2, ghrelin and

Solubilization and molecular size of atrial natriuretic hormone (ANH) receptors from rabbit aorta, renal cortex and adrenal

International Nuclear Information System (INIS)

Budzik, G.P.; Bush, E.N.; Holleman, W.H.

1986-01-01

ANH(1-28) is presumed to regulate blood pressure and fluid balance via membrane receptors coupled to particulate guanylate cyclase. ANH receptors were solubilized from rabbit aorta, renal cortex and adrenal, primary ANH targets. Plasma membranes extracted with 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate(CHAPS) yield solubilized receptors with high affinity binding of 125 I-Tyr 28 -ANH. Degradation of hormone was minimized with a broad spectrum of protease inhibitors. 125 I-ANH binding reached maximum by 1 hr at 0 0 C and was stable for at least an additional 2 hrs. Bound was separated from free ligand by HPLC gel filtration on TSK-3000SW in PBS/CHAPS. Bound hormone eluted at a MW of ∼ 200KD in each tissue preparation and was displaced by unlabelled ANH. The concentration of solubilized binding sites was proportional to densities in intact plasma membranes, i.e., adrenal > renal > aorta. Following separation of free hormone, 125 I-ANH-receptors complexes were coupled using bifunctional crosslinking reagents. SDS-PAGE analysis and autoradiography indicated a major labelled band at ∼ 150KD in each tissue preparation. The mobility of this labelled band was not sensitive to reduction before SDS-PAGE. Although these results suggest that solubilized ANH receptors from primary target tissues are very similar, microheterogeneity affecting binding affinity or signal transduction cannot as yet be excluded

Requirement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor for selected GH-stimulated function

DEFF Research Database (Denmark)

Lobie, P E; Allevato, G; Norstedt, G

1995-01-01

We have examined the involvement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor in the cellular response to GH. Stable Chinese hamster ovary (CHO) cell clones expressing a receptor with tyrosine residues at position 333 and 338 of the receptor substituted for phenylalanine (...

Expression and function of the human estrogen receptor in yeast

International Nuclear Information System (INIS)

White, J.H.; Metzger, D.; Chambon, P.

1988-01-01

Gene expression in eukaryotes is regulated at many levels. Moreover, there is increasing evidence that the basic control mechanisms of transcription initiation have been conserved across the range of eukaryotes from yeast to man. In vertebrates, the nuclear receptors, whose activity is dependent on the binding of specific ligands, stimulate transcription by interacting with specific cis-acting sequences and display all of the hallmarks of inducible enhancer factors. Alignment of their amino acid sequences indicates that they are composed of a series of conserved domains. The domain structure of the human estrogen receptor (hER) is typical of receptor proteins. Region C, containing two putative zinc fingers, comprises the DNA-binding domain responsible for specific recognition of estrogen response elements (ERE). Region E contains the hormone-binding domain and domain(s) responsible for transcription activation. A mutant of the hER, called HE15, which lacks the hormone-binding domain, binds DNA in vivo and in vitro but activates transcription only poorly in a constitutive manner in vivo in HeLa cells. A series of studies have demonstrated that the hormone- and DNA-binding domains of the nuclear receptors function independently. Chimeric proteins consisting of the DNA-binding domain of yeast GAL4 coupled to the hormone-binding domains of either the hER or glucocorticoid receptor element (GRE) will stimulate transcription in HeLa cells when bound to a UAS. Taken together, these results demonstrate that the hER and other nuclear receptors, as well as GAL4 and GCN4 proteins of yeast, consist of discrete and separable DNA-binding and transcription-activation functions. To investigate these striking parallels further, the authors have expressed the hER in the yeast Saccharomyces cerevisiae and have analyzed its hormone- and DNA-binding properties in vitro and its ability to stimulate transcription in vivo

Enhanced thyroid hormone breakdown in hepatocytes by mutual induction of the constitutive androstane receptor (CAR, NR1I3) and arylhydrocarbon receptor by benzo[a]pyrene and phenobarbital

International Nuclear Information System (INIS)

Schraplau, Anne; Schewe, Bettina; Neuschäfer-Rube, Frank; Ringel, Sebastian; Neuber, Corinna; Kleuser, Burkhard; Püschel, Gerhard P.

2015-01-01

Xenobiotics may interfere with the hypothalamic-pituitary-thyroid endocrine axis by inducing enzymes that inactivate thyroid hormones and thereby reduce the metabolic rate. This induction results from an activation of xeno-sensing nuclear receptors. The current study shows that benzo[a]pyrene, a frequent contaminant of processed food and activator of the arylhydrocarbon receptor (AhR) activated the promoter and induced the transcription of the nuclear receptor constitutive androstane receptor (CAR, NR1I3) in rat hepatocytes. Likewise, phenobarbital induced the AhR transcription. This mutual induction of the nuclear receptors enhanced the phenobarbital-dependent induction of the prototypic CAR target gene Cyp2b1 as well as the AhR-dependent induction of UDP-glucuronosyltransferases. In both cases, the induction by the combination of both xenobiotics was more than the sum of the induction by either substance alone. By inducing the AhR, phenobarbital enhanced the benzo[a]pyrene-dependent reduction of thyroid hormone half-life and the benzo[a]pyrene-dependent increase in the rate of thyroid hormone glucuronide formation in hepatocyte cultures. CAR ligands might thus augment the endocrine disrupting potential of AhR activators by an induction of the AhR

The Fifth Transmembrane Domain of Angiotensin II Type 1 Receptor Participates in the Formation of the Ligand-binding Pocket and Undergoes a Counterclockwise Rotation upon Receptor Activation*

Science.gov (United States)

Domazet, Ivana; Martin, Stéphane S.; Holleran, Brian J.; Morin, Marie-Ève; Lacasse, Patrick; Lavigne, Pierre; Escher, Emanuel; Leduc, Richard; Guillemette, Gaétan

2009-01-01

The octapeptide hormone angiotensin II exerts a wide variety of cardiovascular effects through the activation of the angiotensin II Type 1 (AT1) receptor, which belongs to the G protein-coupled receptor superfamily. Like other G protein- coupled receptors, the AT1 receptor possesses seven transmembrane domains that provide structural support for the formation of the ligand-binding pocket. The role of the fifth transmembrane domain (TMD5) was investigated using the substituted cysteine accessibility method. All of the residues within Thr-190 to Leu-217 region were mutated one at a time to cysteine, and after expression in COS-7 cells, the mutant receptors were treated with the sulfhydryl-specific alkylating agent methanethiosulfonate-ethylammonium (MTSEA). MTSEA reacts selectively with water-accessible, free sulfhydryl groups of endogenous or introduced point mutation cysteines. If a cysteine is found in the binding pocket, the covalent modification will affect the binding kinetics of the ligand. MTSEA substantially decreased the binding affinity of L197C-AT1, N200C-AT1, I201C-AT1, G203C-AT1, and F204C-AT1 mutant receptors, which suggests that these residues orient themselves within the water-accessible binding pocket of the AT1 receptor. Interestingly, this pattern of acquired MTSEA sensitivity was altered for TMD5 reporter cysteines engineered in a constitutively active N111G-AT1 receptor background. Indeed, mutant I201C-N111G-AT1 became more sensitive to MTSEA, whereas mutant G203C-N111G-AT1 lost some sensitivity. Our results suggest that constitutive activation of AT1 receptor causes an apparent counterclockwise rotation of TMD5 as viewed from the extracellular side. PMID:19773549

The fifth transmembrane domain of angiotensin II Type 1 receptor participates in the formation of the ligand-binding pocket and undergoes a counterclockwise rotation upon receptor activation.

Science.gov (United States)

Domazet, Ivana; Martin, Stéphane S; Holleran, Brian J; Morin, Marie-Eve; Lacasse, Patrick; Lavigne, Pierre; Escher, Emanuel; Leduc, Richard; Guillemette, Gaétan

2009-11-13

The octapeptide hormone angiotensin II exerts a wide variety of cardiovascular effects through the activation of the angiotensin II Type 1 (AT(1)) receptor, which belongs to the G protein-coupled receptor superfamily. Like other G protein- coupled receptors, the AT(1) receptor possesses seven transmembrane domains that provide structural support for the formation of the ligand-binding pocket. The role of the fifth transmembrane domain (TMD5) was investigated using the substituted cysteine accessibility method. All of the residues within Thr-190 to Leu-217 region were mutated one at a time to cysteine, and after expression in COS-7 cells, the mutant receptors were treated with the sulfhydryl-specific alkylating agent methanethiosulfonate-ethylammonium (MTSEA). MTSEA reacts selectively with water-accessible, free sulfhydryl groups of endogenous or introduced point mutation cysteines. If a cysteine is found in the binding pocket, the covalent modification will affect the binding kinetics of the ligand. MTSEA substantially decreased the binding affinity of L197C-AT(1), N200C-AT(1), I201C-AT(1), G203C-AT(1), and F204C-AT(1) mutant receptors, which suggests that these residues orient themselves within the water-accessible binding pocket of the AT(1) receptor. Interestingly, this pattern of acquired MTSEA sensitivity was altered for TMD5 reporter cysteines engineered in a constitutively active N111G-AT(1) receptor background. Indeed, mutant I201C-N111G-AT(1) became more sensitive to MTSEA, whereas mutant G203C-N111G-AT(1) lost some sensitivity. Our results suggest that constitutive activation of AT(1) receptor causes an apparent counterclockwise rotation of TMD5 as viewed from the extracellular side.

Thyroid Hormone Receptor α Mutation Causes a Severe and Thyroxine-Resistant Skeletal Dysplasia in Female Mice

Science.gov (United States)

Bassett, J. H. Duncan; Boyde, Alan; Zikmund, Tomas; Evans, Holly; Croucher, Peter I.; Zhu, Xuguang; Park, Jeong Won

2014-01-01

A new genetic disorder has been identified that results from mutation of THRA, encoding thyroid hormone receptor α1 (TRα1). Affected children have a high serum T3:T4 ratio and variable degrees of intellectual deficit and constipation but exhibit a consistently severe skeletal dysplasia. In an attempt to improve developmental delay and alleviate symptoms of hypothyroidism, patients are receiving varying doses and durations of T4 treatment, but responses have been inconsistent so far. Thra1PV/+ mice express a similar potent dominant-negative mutant TRα1 to affected individuals, and thus represent an excellent disease model. We hypothesized that Thra1PV/+ mice could be used to predict the skeletal outcome of human THRA mutations and determine whether prolonged treatment with a supraphysiological dose of T4 ameliorates the skeletal abnormalities. Adult female Thra1PV/+ mice had short stature, grossly abnormal bone morphology but normal bone strength despite high bone mass. Although T4 treatment suppressed TSH secretion, it had no effect on skeletal maturation, linear growth, or bone mineralization, thus demonstrating profound tissue resistance to thyroid hormone. Despite this, prolonged T4 treatment abnormally increased bone stiffness and strength, suggesting the potential for detrimental consequences in the long term. Our studies establish that TRα1 has an essential role in the developing and adult skeleton and predict that patients with different THRA mutations will display variable responses to T4 treatment, which depend on the severity of the causative mutation. PMID:24914936

Constitutive activation of the thyroid-stimulating hormone receptor (TSHR by mutating Ile691 in the cytoplasmic tail segment.

Directory of Open Access Journals (Sweden)

Zheng Liu

Full Text Available BACKGROUND: Autosomal dominant non-autoimmune hyperthyroidism (ADNAH is a rare genetic disorder of the endocrine system. Molecular genetic studies in ADNAH have revealed heterozygous germline mutations in the TSHR. To data, mutations leading to an increase in the constitutive activation of the TSHR have been described in the transmembrane segments, exoloops and cytoplasmic loop of TSHR. These mutations result in constitutive activation of the G(αs/cAMP or G(αq/11/inositol phosphate (IP pathways, which stimulate thyroid hormone production and thyroid proliferation. METHODOLOGY/PRINCIPAL FINDINGS: In a previous study, we reported a new TSHR mutation located in the C-terminal domain of TSHR, which results in a substitution of the conserved Ile(691 for Phe. In this study, to address the question of whether the I691F mutated receptor could be responsible for G(αs/cAMP or G(αq/11/IP constitutive activity, wild-type and TSHR mutants were expressed in COS-7 cells to determine cAMP constitutive activity and IP formation. Compared to the cell surface with expression of the A623V mutated receptor as positive control, the I691F mutated receptor showed a slight increase of cAMP accumulation. Furthermore, I691F resulted in constitutive activation of the G(αq/11/IP signaling pathway. CONCLUSIONS/SIGNIFICANCE: Our results indicate that Ile(691 not only contributes to keeping TSHR inactive in the G(αs/cAMP pathways but also in the G(αq/11/IP cascade.

The liver taxis of receptor mediated lactosaminated human growth hormone

International Nuclear Information System (INIS)

Chen Zelian; Shi Lin; Li Tongling; Pang Qijie; He Juying; Guan Changtian

2002-01-01

Radiography imaging is used to assess liver taxis mechanism of anti-dwarfism drug lactosaminated human growth hormone (L-rhGH). Both L-rhGH and rhGH labelled with 131 I are used to study their biodistribution in animals (including rabbits, cocks and rats). The results show that L-rhGH is of specific hepatic targeting property, and the maximum hepatic concentration rate is 76.8%, which is two times of rhGH. Its hepatic binding is receptor mediated

The polymorphic insertion of the luteinizing hormone receptor "insLQ" show a negative association to LHR gene expression and to the follicular fluid hormonal profile in human small antral follicles

DEFF Research Database (Denmark)

Borgbo, T; Chrudimska, J; Macek, M

2018-01-01

(AMHR2) and LHCGR, respectively, were observed for insLQ/insLQ compared to -/insLQ and the -/- genotypes. Moreover, LHCGR and CYP19a1 together with oestradiol and inhibin-B were significantly increased in -/insLQ compared to the -/- genotype. The homozygous insLQ genotype showed strong significant......The luteinizing hormone receptor (LHCGR) has a little studied polymorphic 6 bp insertion (rs4539842/insLQ). This study has evaluated the insLQ polymorphism in relation to potential associations with hormonal characteristics of human small antral follicles (hSAFs). In total, 310 hSAFs were collected...... from 86 women undergoing fertility preservation. Analysis included hormonal profile of 297 follicular fluid (FF) samples and 148 corresponding granulosa cells samples were evaluated by qPCR for selected genes. Significantly reduced and non-detectable mRNA levels of anti-Müllerian hormone receptor II...

Signal transduction by normal isoforms and W mutant variants of the Kit receptor tyrosine kinase.

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Reith, A D; Ellis, C; Lyman, S D; Anderson, D M; Williams, D E; Bernstein, A; Pawson, T

1991-09-01

Germline mutations at the Dominant White Spotting (W) and Steel (Sl) loci have provided conclusive genetic evidence that c-kit mediated signal transduction pathways are essential for normal mouse development. We have analysed the interactions of normal and mutant W/c-kit gene products with cytoplasmic signalling proteins, using transient c-kit expression assays in COS cells. In addition to the previously identified c-kit gene product (Kit+), a second normal Kit isoform (KitA+) containing an in-frame insertion, Gly-Asn-Asn-Lys, within the extracellular domain, was detected in murine mast cell cultures and mid-gestation placenta. Both Kit+ and KitA+ isoforms showed increased autophosphorylation and enhanced association with phosphatidylinositol (PI) 3' kinase and PLC gamma 1, when stimulated with recombinant soluble Steel factor. No association or increase in phosphorylation of GAP and two GAP-associated proteins, p62 and p190, was observed. The two isoforms had distinct activities in the absence of exogenous soluble Steel factor; Kit+, but not KitA+, showed constitutive tyrosine phosphorylation that was accompanied by a low constitutive level of association with PI-3' kinase and PLC gamma 1. Introduction of the point substitutions associated with W37 (Glu582----Lys) or W41 (Val831----Met) mutant alleles into c-kit expression constructs abolished (W37) or reduced (W41) the Steel factor-induced association of the Kit receptor with signalling proteins in a manner proportional to the overall severity of the corresponding W mutant phenotype. These data suggest a diversity of normal Kit signalling pathways and indicate that W mutant phenotypes result from primary defects in the Kit receptor that affect its interaction with cytoplasmic signalling proteins.

Effects of growth hormone treatment on the pituitary expression of GHRH receptor mRNA in uremic rats.

Science.gov (United States)

Ferrando, Susana; Rodríguez, Julián; Santos, Fernando; Weruaga, Ana; Fernández, Marta; Carbajo, Eduardo; García, Enrique

2002-09-01

A decreased ability of pituitary cells to secrete growth hormone (GH) in response to growth hormone releasing hormone (GHRH) stimulation has been shown in young uremic rats. The aim of the current study was to examine the effect of uremia and GH treatment on pituitary GHRH receptor expression. Pituitary GHRH receptor mRNA levels were analyzed by RNase protection assay in young female rats made uremic by subtotal nephrectomy, either untreated (UREM) or treated with 10 IU/kg/day of GH (UREM-GH), and normal renal function animals fed ad libitum (SAL) or pair-fed with the UREM group (SPF). Rats were sacrificed 14 days after the second stage nephrectomy. Renal failure was confirmed by concentrations (X +/- SEM) of serum urea nitrogen (mmol/L) and creatinine (micromol/L) in UREM (20 +/- 1 and 89.4 +/- 4.5) and UREM-GH (16 +/- 1 and 91.4 +/- 6.9) that were much higher (P growth retarded as shown by a daily longitudinal tibia growth rate below (P growth rate acceleration (213 +/- 6 microm/day). GHRH receptor mRNA levels were no different among the SAL (0.43 +/- 0.03), SPF (0.43 +/- 0.08) and UREM (0.44 +/- 0.04) groups, whereas UREM-GH rats had significantly higher values (0.72 +/- 0.07). The status of pituitary GHRH receptor is not modified by nutritional deficit or by severe uremia causing growth retardation. By contrast, the growth promoting effect of GH administration is associated with stimulated GHRH receptor gene expression.

Discrepancy between molecular structure and ligand selectivity of a testicular follicle-stimulating hormone receptor of the African catfish (Clarias gariepinus)

NARCIS (Netherlands)

Bogerd, J.; Blomenröhr, M.; Andersson, E.; van der Putten, H.; Tensen, C.P.; Vischer, H F; Granneman, Joke C M; Janssen-Dommerholt, C; Goos, H.J.; Schulz, Rüdiger W

A putative FSH receptor (FSH-R) cDNA was cloned from African catfish testis. Alignment of the deduced amino acid sequence with other (putative) glycoprotein hormone receptors and analysis of the African catfish gene indicated that the cloned receptor belonged to the FSH receptor subfamily. Catfish

Triiodothyronine affects the alternative splicing of thyroid hormone receptor alpha mRNA

NARCIS (Netherlands)

Timmer, D. C.; Bakker, O.; Wiersinga, W. M.

2003-01-01

The c-erbAalpha gene encodes two thyroid hormone receptors, TRalpha1 and TRalpha2, that arise from alternative splicing of the TRalpha pre-mRNA. TRalpha2 is not able to bind triiodothyronine (T-3) and acts as a weak antagonist of TRs. It has been suggested that the balance of TRalpha1 to TRalpha2 is

Screening of hormone-like activities in bottled waters available in Southern Spain using receptor-specific bioassays.

Science.gov (United States)

Real, Macarena; Molina-Molina, José-Manuel; Jiménez-Díaz, Inmaculada; Arrebola, Juan Pedro; Sáenz, José-María; Fernández, Mariana F; Olea, Nicolás

2015-01-01

Bottled water consumption is a putative source of human exposure to endocrine-disrupting chemicals (EDCs). Research has been conducted on the presence of chemicals with estrogen-like activity in bottled waters and on their estrogenicity, but few data are available on the presence of hormonal activities associated with other nuclear receptors (NRs). The aim of this study was to determine the presence of endocrine activities dependent on the activation of human estrogen receptor alpha (hERa) and/or androgen receptor (hAR) in water in glass or plastic bottles sold to consumers in Southern Spain. Hormone-like activities were evaluated in 29 bottled waters using receptor-specific bioassays based on reporter gene expression in PALM cells [(anti-)androgenicity] and cell proliferation assessment in MCF-7 cells [(anti-)estrogenicity] after optimized solid phase extraction (SPE). All of the water samples analyzed showed hormonal activity. This was estrogenic in 79.3% and anti-estrogenic in 37.9% of samples and was androgenic in 27.5% and anti-androgenic in 41.3%, with mean concentrations per liter of 0.113pM 17β-estradiol (E2) equivalent units (E2Eq), 11.01pM anti-estrogen (ICI 182780) equivalent units (ICI 182780Eq), 0.33pM methyltrienolone (R1881) equivalent units (R1881Eq), and 0.18nM procymidone equivalent units (ProcEq). Bottled water consumption contributes to EDC exposure. Hormone-like activities observed in waters from both plastic and glass bottles suggest that plastic packaging is not the sole source of contamination and that the source of the water and bottling process may play a role, among other factors. Further research is warranted on the cumulative effects of long-term exposure to low doses of EDCs. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Clinical relevance of ESR1 circulating mutations detection in hormone receptor positive metastatic breast cancer].

Science.gov (United States)

Clatot, Florian; Perdrix, Anne; Sefrioui, David; Sarafan-Vasseur, Nasrin; Di Fiore, Frédéric

2018-01-01

If hormone therapy is a key treatment for hormone receptor positive advanced breast cancers, secondary resistance occurs as a rule. Recently, acquired alterations of the ESR1 gene have been identified as a mechanism of resistance on aromatase inhibitor (AI) treatment. The selective pressure by AI exposure during the metastatic setting triggers the emergence of ESR1 activating mutations. In that context, the "liquid biopsy" concept has been used to detect this molecular resistance before progression. Thus, the ESR1 circulating mutation detection will soon be used in daily practice to help monitoring patients on AI treatment and provide an early change for specific therapies that still have to be determined in prospective clinical trials. This review will present the acquired ESR1 mutations, as well as the methods used for their detection in blood and the potential clinical impact of this approach for hormone receptor positive breast cancer management. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Ligand-independent Thrombopoietin Mutant Receptor Requires Cell Surface Localization for Endogenous Activity*

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Marty, Caroline; Chaligné, Ronan; Lacout, Catherine; Constantinescu, Stefan N.; Vainchenker, William; Villeval, Jean-Luc

2009-01-01

The activating W515L mutation in the thrombopoietin receptor (MPL) has been identified in primary myelofibrosis and essential thrombocythemia. MPL belongs to a subset of the cytokine receptor superfamily that requires the JAK2 kinase for signaling. We examined whether the ligand-independent MPLW515L mutant could signal intracellularly. Addition of the endoplasmic reticulum (ER) retention KDEL sequence to the receptor C terminus efficiently locked MPLW515L within its natural ER/Golgi maturation pathway. In contrast to cells expressing the parental MPLW515L, MPLW515L-KDEL-expressing FDC-P1 cells were unable to grow autonomously and to produce tumors in nude mice. When observed, tumor nodules resulted from in vivo selection of cells leaking the receptor at their surface. JAK2 co-immunoprecipitated with MPLW515L-KDEL but was not phosphorylated. We generated disulfide-bonded MPLW515L homodimers by the S402C substitution, both in the normal and KDEL context. Unlike MPLW515L-KDEL, MPLW515L-S402C-KDEL signaled constitutively and exhibited cell surface localization. These data establish that MPLW515L with appended JAK2 matures through the ER/Golgi system in an inactive conformation and suggest that the MPLW515L/JAK2 complex requires membrane localization for JAK2 phosphorylation, resulting in autonomous receptor signaling. PMID:19261614

Increased circulating interleukin-8 in patients with resistance to thyroid hormone receptor alpha

NARCIS (Netherlands)

van der Spek, Anne H.; Surovtseva, Olga V.; Aan, Saskia; Tool, Anton T. J.; van de Geer, Annemarie; Demir, Korcan; van Gucht, Anja L. M.; van Trotsenburg, A. S. Paul; van den Berg, Timo K.; Fliers, Eric; Boelen, Anita

2017-01-01

Innate immune cells have recently been identified as novel thyroid hormone (TH) target cells in which intracellular TH levels appear to play an important functional role. The possible involvement of TH receptor alpha (TR alpha), which is the predominant TR in these cells, has not been studied to

Enhanced thyroid hormone breakdown in hepatocytes by mutual induction of the constitutive androstane receptor (CAR, NR1I3) and arylhydrocarbon receptor by benzo[a]pyrene and phenobarbital.

Science.gov (United States)

Schraplau, Anne; Schewe, Bettina; Neuschäfer-Rube, Frank; Ringel, Sebastian; Neuber, Corinna; Kleuser, Burkhard; Püschel, Gerhard P

2015-02-03

Xenobiotics may interfere with the hypothalamic-pituitary-thyroid endocrine axis by inducing enzymes that inactivate thyroid hormones and thereby reduce the metabolic rate. This induction results from an activation of xeno-sensing nuclear receptors. The current study shows that benzo[a]pyrene, a frequent contaminant of processed food and activator of the arylhydrocarbon receptor (AhR) activated the promoter and induced the transcription of the nuclear receptor constitutive androstane receptor (CAR, NR1I3) in rat hepatocytes. Likewise, phenobarbital induced the AhR transcription. This mutual induction of the nuclear receptors enhanced the phenobarbital-dependent induction of the prototypic CAR target gene Cyp2b1 as well as the AhR-dependent induction of UDP-glucuronosyltransferases. In both cases, the induction by the combination of both xenobiotics was more than the sum of the induction by either substance alone. By inducing the AhR, phenobarbital enhanced the benzo[a]pyrene-dependent reduction of thyroid hormone half-life and the benzo[a]pyrene-dependent increase in the rate of thyroid hormone glucuronide formation in hepatocyte cultures. CAR ligands might thus augment the endocrine disrupting potential of AhR activators by an induction of the AhR. Copyright © 2014. Published by Elsevier Ireland Ltd.

Identification of phenylalanine 346 in the rat growth hormone receptor as being critical for ligand-mediated internalization and down-regulation

DEFF Research Database (Denmark)

Allevato, G; Billestrup, N; Goujon, L

1995-01-01

The functional significance of growth hormone (GH) receptor (GHR) internalization is unknown; therefore, we have analyzed domains and individual amino acids in the cytoplasmic region of the rat GHR required for ligand-mediated receptor internalization, receptor down-regulation, and transcriptiona...

H-2RIIBP, a member of the nuclear hormone receptor superfamily that binds to both the regulatory element of major histocompatibility class I genes and the estrogen response element.

Science.gov (United States)

Hamada, K; Gleason, S L; Levi, B Z; Hirschfeld, S; Appella, E; Ozato, K

1989-11-01

Transcription of major histocompatibility complex (MHC) class I genes is regulated by the conserved MHC class I regulatory element (CRE). The CRE has two factor-binding sites, region I and region II, both of which elicit enhancer function. By screening a mouse lambda gt 11 library with the CRE as a probe, we isolated a cDNA clone that encodes a protein capable of binding to region II of the CRE. This protein, H-2RIIBP (H-2 region II binding protein), bound to the native region II sequence, but not to other MHC cis-acting sequences or to mutant region II sequences, similar to the naturally occurring region II factor in mouse cells. The deduced amino acid sequence of H-2RIIBP revealed two putative zinc fingers homologous to the DNA-binding domain of steroid/thyroid hormone receptors. Although sequence similarity in other regions was minimal, H-2RIIBP has apparent modular domains characteristic of the nuclear hormone receptors. Further analyses showed that both H-2RIIBP and the natural region II factor bind to the estrogen response element (ERE) of the vitellogenin A2 gene. The ERE is composed of a palindrome, and half of this palindrome resembles the region II binding site of the MHC CRE. These results indicate that H-2RIIBP (i) is a member of the superfamily of nuclear hormone receptors and (ii) may regulate not only MHC class I genes but also genes containing the ERE and related sequences. Sequences homologous to the H-2RIIBP gene are widely conserved in the animal kingdom. H-2RIIBP mRNA is expressed in many mouse tissues, in agreement with the distribution of the natural region II factor.

Frequency of mutant T lymphocytes defective in the expression of the T-cell antigen receptor gene among radiation-exposed people

International Nuclear Information System (INIS)

Kyoizumi, Seishi; Umeki, Shigeko; Akiyama, Mitoshi

1991-06-01

The frequency of mutant T lymphocytes defective in T-cell receptor gene (α or β) expression was measured using the two-color flow cytometric technique. Results for a total of 203 atomic bomb survivors, 78 of whom were proximally exposed (DS86 doses of ≥ 1.5 Gy) and 125 of whom were distally exposed (DS86 doses of 228 Th formerly used for radiodiagnosis. In addition, thyroid disease patients treated with 131 I showed a dose-related increase of mutant frequency. It was suggested that the present T-cell receptor mutation assay has a unique characteristic as a biological dosimeter for the measurement of recent exposures to genotoxic agents. (author)

Identification of a novel modulator of thyroid hormone receptor-mediated action.

Directory of Open Access Journals (Sweden)

Bernhard G Baumgartner

Full Text Available BACKGROUND: Diabetes is characterized by reduced thyroid function and altered myogenesis after muscle injury. Here we identify a novel component of thyroid hormone action that is repressed in diabetic rat muscle. METHODOLOGY/PRINCIPAL FINDINGS: We have identified a gene, named DOR, abundantly expressed in insulin-sensitive tissues such as skeletal muscle and heart, whose expression is highly repressed in muscle from obese diabetic rats. DOR expression is up-regulated during muscle differentiation and its loss-of-function has a negative impact on gene expression programmes linked to myogenesis or driven by thyroid hormones. In agreement with this, DOR enhances the transcriptional activity of the thyroid hormone receptor TR(alpha1. This function is driven by the N-terminal part of the protein. Moreover, DOR physically interacts with TR( alpha1 and to T(3-responsive promoters, as shown by ChIP assays. T(3 stimulation also promotes the mobilization of DOR from its localization in nuclear PML bodies, thereby indicating that its nuclear localization and cellular function may be related. CONCLUSIONS/SIGNIFICANCE: Our data indicate that DOR modulates thyroid hormone function and controls myogenesis. DOR expression is down-regulated in skeletal muscle in diabetes. This finding may be of relevance for the alterations in muscle function associated with this disease.

Capacity for cooperative binding of thyroid hormone (T3) receptor dimers defines wild type T3 response elements.

Science.gov (United States)

Brent, G A; Williams, G R; Harney, J W; Forman, B M; Samuels, H H; Moore, D D; Larsen, P R

1992-04-01

Thyroid hormone response elements (T3REs) have been identified in a variety of promoters including those directing expression of rat GH (rGH), alpha-myosin heavy chain (rMHC), and malic enzyme (rME). A detailed biochemical and genetic analysis of the rGH element has shown that it consists of three hexamers related to the consensus [(A/G)GGT(C/A)A]. We have extended this analysis to the rMHC and rME elements. Binding of highly purified thyroid hormone receptor (T3R) to T3REs was determined using the gel shift assay, and thyroid hormone (T3) induction was measured in transient tranfections. We show that the wild type version of each of the three elements binds T3R dimers cooperatively. Mutational analysis of the rMHC and rME elements identified domains important for binding T3R dimers and allowed a direct determination of the relationship between T3R binding and function. In each element two hexamers are required for dimer binding, and mutations that interfere with dimer formation significantly reduce T3 induction. Similar to the rGH element, the rMHC T3RE contains three hexameric domains arranged as a direct repeat followed by an inverted copy, although the third domain is weaker than in rGH. All three are required for full function and T3R binding. The rME T3RE is a two-hexamer direct repeat T3RE, which also binds T3R monomer and dimer. Across a series of mutant elements, there was a strong correlation between dimer binding in vitro and function in vivo for rMHC (r = 0.99, P less than 0.01) and rME (r = 0.67, P less than 0.05) T3REs. Our results demonstrate a similar pattern of T3R dimer binding to a diverse array of hexameric sequences and arrangements in three wild type T3REs. Addition of nuclear protein enhanced T3R binding but did not alter the specificity of binding to wild type or mutant elements. Binding of purified T3R to T3REs was highly correlated with function, both with and without the addition of nuclear protein. T3R dimer formation is the common

Putative thyroid hormone receptors in red blood cells of some reptiles.

Science.gov (United States)

Wong, C C; Chiu, K W

1987-06-01

Putative triiodothyronine (T3) receptors have been detected in the nuclei of red blood cells (RBC) in a number of reptile species. The binding characteristics of T3 receptors in vitro were dissociation constant (Kd) 9.1 to 28.58, 36.8 and 40, and 11.12 and 11.36 pM, and binding capacity (Bmax) 0.12 to 0.37, 0.17 and 0.24, and 0.19 and 0.28 fmol per million cells in the rat snake (Ptyas korros), soft-shelled turtle (Trionyx sinensis), and tokay gecko (Gekko gecko), respectively. These data were obtained in all species using in vitro incubation of whole cell according to current receptor studies on living cells. With modified technique in subsequent experiments, these values of the binding characteristics were seemingly low. The discrepancy was ascribed to the assessment of "free" fraction of hormone which would be used in subsequent calculation.

Diverse growth hormone receptor gene mutations in Laron syndrome.

Science.gov (United States)

Berg, M A; Argente, J; Chernausek, S; Gracia, R; Guevara-Aguirre, J; Hopp, M; Pérez-Jurado, L; Rosenbloom, A; Toledo, S P; Francke, U

1993-01-01

To better understand the molecular genetic basis and genetic epidemiology of Laron syndrome (growth-hormone insensitivity syndrome), we analyzed the growth-hormone receptor (GHR) genes of seven unrelated affected individuals from the United States, South America, Europe, and Africa. We amplified all nine GHR gene exons and splice junctions from these individuals by PCR and screened the products for mutations by using denaturing gradient gel electrophoresis (DGGE). We identified a single GHR gene fragment with abnormal DGGE results for each affected individual, sequenced this fragment, and, in each case, identified a mutation likely to cause Laron syndrome, including two nonsense mutations (R43X and R217X), two splice-junction mutations, (189-1 G to T and 71 + 1 G to A), and two frameshift mutations (46 del TT and 230 del TA or AT). Only one of these mutations, R43X, has been previously reported. Using haplotype analysis, we determined that this mutation, which involves a CpG dinucleotide hot spot, likely arose as a separate event in this case, relative to the two prior reports of R43X. Aside from R43X, the mutations we identified are unique to patients from particular geographic regions. Ten GHR gene mutations have now been described in this disorder. We conclude that Laron syndrome is caused by diverse GHR gene mutations, including deletions, RNA processing defects, translational stop codons, and missense codons. All the identified mutations involve the extracellular domain of the receptor, and most are unique to particular families or geographic areas. Images Figure 1 Figure 2 PMID:8488849

Follicle-stimulating hormone (FSH) activates extracellular signal-regulated kinase phosphorylation independently of beta-arrestin- and dynamin-mediated FSH receptor internalization

Science.gov (United States)

Piketty, Vincent; Kara, Elodie; Guillou, Florian; Reiter, Eric; Crepieux, Pascale

2006-01-01

Background The follicle-stimulating hormone receptor (FSH-R) is a seven transmembrane spanning receptor (7TMR) which plays a crucial role in male and female reproduction. Upon FSH stimulation, the FSH-R activates the extracellular signal-regulated kinases (ERK). However, the mechanisms whereby the agonist-stimulated FSH-R activates ERK are poorly understood. In order to activate ERK, some 7 TMRs require beta-arrestin-and dynamin-dependent internalization to occur, whereas some others do not. In the present study, we examined the ability of the FSH-activated FSH-R to induce ERK phosphorylation, in conditions where its beta-arrestin- and dynamin-mediated internalization was impaired. Methods Human embryonic kidney (HEK) 293 cells were transiently transfected with the rat FSH-R. Internalization of the FSH-R was manipulated by co-expression of either a beta-arrestin (319–418) dominant negative peptide, either an inactive dynamin K44A mutant or of wild-type beta-arrestin 1 or 2. The outcomes on the FSH-R internalization were assayed by measuring 125I-FSH binding at the cell surface when compared to internalized 125I-FSH binding. The resulting ERK phosphorylation level was visualized by Western blot analysis. Results In HEK 293 cells, FSH stimulated ERK phosphorylation in a dose-dependent manner. Co-transfection of the beta- arrestin (319–418) construct, or of the dynamin K44A mutant reduced FSH-R internalization in response to FSH, without affecting ERK phosphorylation. Likewise, overexpression of wild-type beta-arrestin 1 or 2 significantly increased the FSH-R internalization level in response to FSH, without altering FSH-induced ERK phosphorylation. Conclusion From these results, we conclude that the FSH-R does not require beta-arrestin- nor dynamin-mediated internalization to initiate ERK phosphorylation in response to FSH. PMID:16787538

Ghrelin: much more than a hunger hormone

Science.gov (United States)

Ghrelin is a multifaceted gut hormone that activates its receptor, growth hormone secretagogue receptor (GHS-R). Ghrelin's hallmark functions are its stimulatory effects on growth hormone release, food intake and fat deposition. Ghrelin is famously known as the 'hunger hormone'. However, ample recen...

The Second Transmembrane Domain of the Human Type 1 Angiotensin II Receptor Participates in the Formation of the Ligand Binding Pocket and Undergoes Integral Pivoting Movement during the Process of Receptor Activation*

Science.gov (United States)

Domazet, Ivana; Holleran, Brian J.; Martin, Stéphane S.; Lavigne, Pierre; Leduc, Richard; Escher, Emanuel; Guillemette, Gaétan

2009-01-01

The octapeptide hormone angiotensin II (AngII) exerts a wide variety of cardiovascular effects through the activation of the angiotensin II type-1 (AT1) receptor, which belongs to the G protein-coupled receptor superfamily. Like other G protein-coupled receptors, the AT1 receptor possesses seven transmembrane domains that provide structural support for the formation of the ligand-binding pocket. In order to identify those residues in the second transmembrane domain (TMD2) that contribute to the formation of the binding pocket of the AT1 receptor, we used the substituted cysteine accessibility method. All of the residues within the Leu-70 to Trp-94 region were mutated one at a time to a cysteine, and, after expression in COS-7 cells, the mutant receptors were treated with the sulfhydryl-specific alkylating agent methanethiosulfonate-ethylammonium (MTSEA). MTSEA reacts selectively with water-accessible, free sulfhydryl groups of endogenous or introduced point mutation cysteines. If a cysteine is found in the binding pocket, the covalent modification will affect the binding kinetics of the ligand. MTSEA substantially decreased the binding affinity of D74C-AT1, L81C-AT1, A85C-AT1, T88C-AT1, and A89C-AT1 mutant receptors, which suggests that these residues orient themselves within the water-accessible binding pocket of the AT1 receptor. Interestingly, this pattern of acquired MTSEA sensitivity was altered for TMD2 reporter cysteines engineered in a constitutively active N111G-AT1 receptor background. Indeed, mutant D74C-N111G-AT1 became insensitive to MTSEA, whereas mutant L81C-N111G-AT1 lost some sensitivity and mutant V86C-N111G-AT1 became sensitive to MTSEA. Our results suggest that constitutive activation of the AT1 receptor causes TMD2 to pivot, bringing the top of TMD2 closer to the binding pocket and pushing the bottom of TMD2 away from the binding pocket. PMID:19276075

The second transmembrane domain of the human type 1 angiotensin II receptor participates in the formation of the ligand binding pocket and undergoes integral pivoting movement during the process of receptor activation.

Science.gov (United States)

Domazet, Ivana; Holleran, Brian J; Martin, Stéphane S; Lavigne, Pierre; Leduc, Richard; Escher, Emanuel; Guillemette, Gaétan

2009-05-01

The octapeptide hormone angiotensin II (AngII) exerts a wide variety of cardiovascular effects through the activation of the angiotensin II type-1 (AT(1)) receptor, which belongs to the G protein-coupled receptor superfamily. Like other G protein-coupled receptors, the AT(1) receptor possesses seven transmembrane domains that provide structural support for the formation of the ligand-binding pocket. In order to identify those residues in the second transmembrane domain (TMD2) that contribute to the formation of the binding pocket of the AT(1) receptor, we used the substituted cysteine accessibility method. All of the residues within the Leu-70 to Trp-94 region were mutated one at a time to a cysteine, and, after expression in COS-7 cells, the mutant receptors were treated with the sulfhydryl-specific alkylating agent methanethiosulfonate-ethylammonium (MTSEA). MTSEA reacts selectively with water-accessible, free sulfhydryl groups of endogenous or introduced point mutation cysteines. If a cysteine is found in the binding pocket, the covalent modification will affect the binding kinetics of the ligand. MTSEA substantially decreased the binding affinity of D74C-AT(1), L81C-AT(1), A85C-AT(1), T88C-AT(1), and A89C-AT(1) mutant receptors, which suggests that these residues orient themselves within the water-accessible binding pocket of the AT(1) receptor. Interestingly, this pattern of acquired MTSEA sensitivity was altered for TMD2 reporter cysteines engineered in a constitutively active N111G-AT(1) receptor background. Indeed, mutant D74C-N111G-AT(1) became insensitive to MTSEA, whereas mutant L81C-N111G-AT(1) lost some sensitivity and mutant V86C-N111G-AT(1) became sensitive to MTSEA. Our results suggest that constitutive activation of the AT(1) receptor causes TMD2 to pivot, bringing the top of TMD2 closer to the binding pocket and pushing the bottom of TMD2 away from the binding pocket.

Crystal structure of the PAC1R extracellular domain unifies a consensus fold for hormone recognition by class B G-protein coupled receptors.

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Shiva Kumar

Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP is a member of the PACAP/glucagon family of peptide hormones, which controls many physiological functions in the immune, nervous, endocrine, and muscular systems. It activates adenylate cyclase by binding to its receptor, PAC1R, a member of class B G-protein coupled receptors (GPCR. Crystal structures of a number of Class B GPCR extracellular domains (ECD bound to their respective peptide hormones have revealed a consensus mechanism of hormone binding. However, the mechanism of how PACAP binds to its receptor remains controversial as an NMR structure of the PAC1R ECD/PACAP complex reveals a different topology of the ECD and a distinct mode of ligand recognition. Here we report a 1.9 Å crystal structure of the PAC1R ECD, which adopts the same fold as commonly observed for other members of Class B GPCR. Binding studies and cell-based assays with alanine-scanned peptides and mutated receptor support a model that PAC1R uses the same conserved fold of Class B GPCR ECD for PACAP binding, thus unifying the consensus mechanism of hormone binding for this family of receptors.

Molecular conformation, receptor binding, and hormone action of natural and synthetic estrogens and antiestrogens.

Science.gov (United States)

Duax, W L; Griffin, J F; Weeks, C M; Korach, K S

1985-01-01

The X-ray crystallographic structural determinations of synthetic estrogens and antiestrogens provide reliable information on the global minimum energy conformation of these molecules or a local minimum energy conformation that is within 1 or 2 kcal/mole of the global minimum. In favorable cases, state-of-the-art molecular mechanics calculations provide quantitative agreement with X-ray results and information on the relative energy of other local minimum energy conformations not observed crystallographically. Because the conformation of diethylstilbestrol (DES) observed in solvated crystals has an overall conformation and dipole moment more similar to estradiol it is the form more likely to bind to the receptor and produce hormone activity. Either phenol ring of DES can successfully mimic the estradiol A-ring in binding to the receptor. Indenestrol A (INDA) and indenestrol B (INDB) have nearly identical fully extended planar conformations. Either the alpha or gamma rings of these compounds may mimic the A ring of estradiol and compete for the estrogen receptor. Although there are eight distinct ways in which molecules of a racemic mixture of INDA or INDB can bind to the receptor, not all of them may be able to elicit a hormonal response. This may account for the reduced biological activity of the compounds despite their successful competition for receptor binding. The minimum energy conformations of Z-pseudodiethylstilbestrol (ZPD) and E-pseudodiethylstilbestrol (EPD) are bent in a fashion similar to that of indanestrol (INDC). These molecules have good binding affinity suggesting that the receptor does not require a flat molecule. Therefore these conformations would appear to be compatible with receptor binding, but only the Z isomer has an energetically allowed extended conformation that accounts for its observed biological activity relative to DES. PMID:3905370

The Arabidopsis NPR1 Protein Is a Receptor for the Plant Defense Hormone Salicylic Acid

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Yue Wu

2012-06-01

Full Text Available Salicylic acid (SA is an essential hormone in plant immunity, but its receptor has remained elusive for decades. The transcriptional coregulator NPR1 is central to the activation of SA-dependent defense genes, and we previously found that Cys521 and Cys529 of Arabidopsis NPR1's transactivation domain are critical for coactivator function. Here, we demonstrate that NPR1 directly binds SA, but not inactive structural analogs, with an affinity similar to that of other hormone-receptor interactions and consistent with in vivo Arabidopsis SA concentrations. Binding of SA occurs through Cys521/529 via the transition metal copper. Mechanistically, our results suggest that binding of SA causes a conformational change in NPR1 that is accompanied by the release of the C-terminal transactivation domain from the N-terminal autoinhibitory BTB/POZ domain. While NPR1 is already known as a link between the SA signaling molecule and defense-gene activation, we now show that NPR1 is the receptor for SA.

Cloning and characterization of the adipokinetic hormone receptor from the cockroach Periplaneta americana

DEFF Research Database (Denmark)

Hansen, Karina K; Hauser, Frank; Cazzamali, Giuseppe

2006-01-01

Cockroaches have long been used as insect models to investigate the actions of biologically active neuropeptides. Here, we describe the cloning and functional expression in Chinese hamster ovary cells of an adipokinetic hormone (AKH) G protein-coupled receptor from the cockroach Periplaneta...... americana. This receptor is only activated by various insect AKHs (we tested eight) and not by a library of 29 other insect or invertebrate neuropeptides and nine biogenic amines. Periplaneta has two intrinsic AKHs, Pea-AKH-1, and Pea-AKH-2. The Periplaneta AKH receptor is activated by low concentrations...... of both Pea-AKH-1 (EC50, 5 x 10(-9)M), and Pea-AKH-2 (EC50, 2 x 10(-9)M). Insects can be subdivided into two evolutionary lineages, holometabola (insects with a complete metamorphosis during development) and hemimetabola (incomplete metamorphosis). This paper describes the first AKH receptor from...

Prognostic value of sex-hormone receptor expression in non-muscle-invasive bladder cancer.

Science.gov (United States)

Nam, Jong Kil; Park, Sung Woo; Lee, Sang Don; Chung, Moon Kee

2014-09-01

We investigated sex-hormone receptor expression as predicting factor of recurrence and progression in patients with non-muscle invasive bladder cancer. We retrospectively evaluated tumor specimens from patients treated for transitional cell carcinoma of the bladder at our institution between January 2006 and January 2011. Performing immunohistochemistry using a monoclonal androgen receptor antibody and monoclonal estrogen receptor-beta antibody on paraffin-embedded tissue sections, we assessed the relationship of immunohistochemistry results and prognostic factors such as recurrence and progression. A total of 169 patients with bladder cancer were evaluated in this study. Sixty-threepatients had expressed androgen receptors and 52 patients had estrogen receptor beta. On univariable analysis, androgen receptor expression was significant lower in recurrence rates (p=0.001), and estrogen receptor beta expression was significant higher in progression rates (p=0.004). On multivariable analysis, significant association was found between androgen receptor expression and lower recurrence rates (hazard ratio=0.500; 95% confidence interval, 0.294 to 0.852; p=0.011), but estrogen receptor beta expression was not significantly associated with progression rates. We concluded that the possibility of recurrence was low when the androgen receptor was expressed in the bladder cancer specimen and it could be the predicting factor of the stage, number of tumors, carcinoma in situ lesion and recurrence.

Role of cysteine residues in the carboxyl-terminus of the follicle-stimulating hormone receptor in intracellular traffic and postendocytic processing

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Brenda Melo-Nava

2016-07-01

Full Text Available Posttranslational modifications occurring during the biosynthesis of G protein-coupled receptors include glycosylation and palmitoylation at conserved cysteine residues located in the carboxyl-terminus (Ctail of the receptor. In a number of these receptors, these modifications play an important role in receptor function and particularly, in intracellular trafficking. In the present study, the three cysteine residues present in the carboxyl-terminus of the human FSHR were replaced with glycine by site-directed mutagenesis. Wild-type and mutant (Cys627/629/655Gly FSHRs were then transiently expressed in HEK-293 cells and analyzed for cell-surface plasma membrane expression, agonist-stimulated signaling and internalization, and postendocytic processing in the abscence and presence of lysosome and/or proteasome inhibitors. Compared with the wild-type FSHR, the triple mutant FSHR exhibited ~70% reduction in plasma membrane expression as well as a profound attenuation in agonist-stimulated cAMP production and ERK1/2 phosphorylation. Incubation of HEK-293 cells expressing the wild-type FSHR with 2-bromopalmitate (palmitoylation inhibitor for 6 h, decreased plasma membrane expression of the receptor by ~30%. The internalization kinetics and β-arrestin 1 and 2 recruitment were similar between the wild-type and triple mutant FSHR as disclosed by assays performed in non-equilibrium binding conditions and by confocal microscopy. Cells expressing the mutant FSHR recycled the internalized FSHR back to the plasma membrane less efficiently than those expressing the wild-type FSHR, an effect that was counteracted by proteasome but not by lysosome inhibition. These results indicate that replacement of the cysteine residues present in the carboxyl-terminus of the FSHR, impairs receptor trafficking from the endoplasmic reticulum/Golgi apparatus to the plasma membrane and its recycling from endosomes back to the cell surface following agonist

Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

International Nuclear Information System (INIS)

Gradishar, William J

2016-01-01

Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed

Autoradiographic localization of thyrotropin releasing hormone (TRH) receptors in the central nervous system

International Nuclear Information System (INIS)

Manaker, S.

1985-01-01

Quantitative autoradiography was used to examine the distribution of thyrotropin-releasing hormone (TRH) receptors in the rat and human central nervous system (CNS). The binding of [ 3 H]-3-methyl-histidine 2 -TRH ([ 3 H]-MeTRH) to TRH receptors was saturable, of a high affinity (K/sub d/ = 5 nM), and specific for TRH analogs. Studies with neurotoxins ibotenic acid and 6-hydroxydopamine (6-OHDA) suggest that TRH receptors within the amygdala are predominantly located on cell bodies, and not nerve terminals. Finally, an examination was made of the concentrations of TRH receptors in spinal cords of patients with amyotrophic lateral sclerosis (ALS), a degenerative disease of the motor neurons located in Lamina IX. Large decreases in TRH receptors were noted in ALS spinal cords, when compared to non-neurological controls, probably reflecting the loss of motor neurons. In addition, decreases in the TRH receptor concentration of Lamina II were observed. This finding may reflect the sensitivity of neurons throughout the CNS to the pathophysiologic mechanisms of neuronal degeneration which cause ALS

Preparation and Characterization of an Antibody Antagonist That Targets the Porcine Growth Hormone Receptor

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Huanzhong Cui

2016-10-01

Full Text Available A series of antagonists specifically targeting growth hormone receptors (GHR in different species, such as humans, rats, bovines, and mice, have been designed; however, there are currently no antagonists that target the porcine growth hormone (GH. Therefore, in this study, we developed and characterized a porcine GHR (pGHR antibody antagonist (denoted by AN98 via the hybridoma technique. The results from enzyme-linked immunosorbent assay, fluorescence activated cell sorter, indirect immunoinfluscent assay, and competitive receptor binding analysis showed that AN98 could specifically recognize pGHR, and further experiments indicated that AN98 could effectively inhibit pGH-induced signalling in CHO-pGHR cells and porcine hepatocytes. In addition, AN98 also inhibited GH-induced insulin-like growth factor-1 (IGF-1 secretion in porcine hepatocytes. In summary, these findings indicated that AN98, as a pGHR-specific antagonist, has potential applications in pGH-pGHR-related research on domestic pigs.

Seasonal Relationship between Gonadotropin, Growth Hormone, and Estrogen Receptor mRNA Expression in the Pituitary Gland of Largemouth Bass

OpenAIRE

Martyniuk, Christopher J; Kroll, Kevin J.; Porak, Wesley F.; Steward, Cheree; Grier, Harry J.; Denslow, Nancy D.

2009-01-01

The objectives of this study were to investigate the seasonal changes in pituitary gonadotropins, growth hormone (GH), and estrogen receptor (ER) isoform mRNA in wild female and male largemouth bass (LMB) (Micropterus salmoides) from an unpolluted habitat to better understand reproductive physiology in this ecologically important species. Female pituitary luteinizing hormone (LH) β subunit and follicle-stimulating hormone (FSH) β subunit mRNA showed significant seasonal variation with levels ...

Radioanalytical methods for the measurement of melanin concentrating hormone (MCH) and detection its receptor in rat tissues

International Nuclear Information System (INIS)

Lelesz, B.; Szilvassy, Z.; Varga, A.; Juhasz, B.; Nemeth, J.; Toth, G.K.; Toth, A.; Enyedi, A.; Felszeghy, E.

2016-01-01

In the present paper the development and application of a novel melanin concentrating hormone radioimmunoassay and receptor-binding assay are described. 125 I-labeling of melanin concentrating hormone (MCH) was performed by iodogen and the mono-iodinated peptide was separated by reversed-phase high performance liquid chromatography. Detection limit of the MCH specific assay was 0.2 fmol/ml. As a practical application of the novel radioimmunoassay, we measured the MCH concentration in different rat organs. High MCH concentrations were detected in the small intestine, pancreas, kidney, liver, trachea, hypothalamus and spinal cord. 125 I-MCH was also suitable for RBA to demonstrate the presence of MCH receptors in the rat brain. (author)

Melanin concentrating hormone receptor 1 (MCHR1) antagonists - Still a viable approach for obesity treatment?

DEFF Research Database (Denmark)

Högberg, T.; Frimurer, T.M.; Sasmal, P.K.

2012-01-01

Obesity is a global epidemic associated with multiple severe diseases. Several pharmacotherapies have been investigated including the melanin concentrating hormone (MCH) and its receptor 1. The development of MCHR1 antagonists are described with a specific perspective on different chemotypes...

Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism)

Energy Technology Data Exchange (ETDEWEB)

Daughaday, W.H.; Trivedi, B.

1987-07-01

It has recently been recognized that human serum contains a protein that specifically binds human growth hormone (hGH). This protein has the same restricted specificity for hGH as the membrane-bound GH receptor. To determine whether the GH-binding protein is a derivative of, or otherwise related to, the GH receptor, the authors have examined the serum of three patients with Laron-type dwarfism, a condition in which GH refractoriness has been attributed to a defect in the GH receptor. The binding of /sup 125/I-labeled hGH incubated with serum has been measured after gel filtration of the serum through an Ultrogel AcA 44 minicolumn. Results are expressed as percent of specifically bound /sup 125/I-hGH and as specific binding relative to that of a reference serum after correction is made for endogenous GH. The mean +/- SEM of specific binding of sera from eight normal adults (26-46 years of age) was 21.6 +/- 0.45%, and the relative specific binding was 101.1 +/- 8.6%. Sera from 11 normal children had lower specific binding of 12.5 +/- 1.95% and relative specific binding of 56.6 +/- 9.1%. Sera from three children with Laron-type dwarfism lacked any demonstrable GH binding, whereas sera from 10 other children with other types of nonpituitary short stature had normal relative specific binding. They suggest that the serum GH-binding protein is a soluble derivative of the GH receptor. Measurement of the serum GH-binding protein may permit recognition of other abnormalities of the GH receptor.

Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism)

International Nuclear Information System (INIS)

Daughaday, W.H.; Trivedi, B.

1987-01-01

It has recently been recognized that human serum contains a protein that specifically binds human growth hormone (hGH). This protein has the same restricted specificity for hGH as the membrane-bound GH receptor. To determine whether the GH-binding protein is a derivative of, or otherwise related to, the GH receptor, the authors have examined the serum of three patients with Laron-type dwarfism, a condition in which GH refractoriness has been attributed to a defect in the GH receptor. The binding of 125 I-labeled hGH incubated with serum has been measured after gel filtration of the serum through an Ultrogel AcA 44 minicolumn. Results are expressed as percent of specifically bound 125 I-hGH and as specific binding relative to that of a reference serum after correction is made for endogenous GH. The mean +/- SEM of specific binding of sera from eight normal adults (26-46 years of age) was 21.6 +/- 0.45%, and the relative specific binding was 101.1 +/- 8.6%. Sera from 11 normal children had lower specific binding of 12.5 +/- 1.95% and relative specific binding of 56.6 +/- 9.1%. Sera from three children with Laron-type dwarfism lacked any demonstrable GH binding, whereas sera from 10 other children with other types of nonpituitary short stature had normal relative specific binding. They suggest that the serum GH-binding protein is a soluble derivative of the GH receptor. Measurement of the serum GH-binding protein may permit recognition of other abnormalities of the GH receptor

Thyroid Hormone, Cancer, and Apoptosis.

Science.gov (United States)

Lin, Hung-Yun; Chin, Yu-Tan; Yang, Yu-Chen S H; Lai, Husan-Yu; Wang-Peng, Jacqueline; Liu, Leory F; Tang, Heng-Yuan; Davis, Paul J

2016-06-13

Thyroid hormones play important roles in regulating normal metabolism, development, and growth. They also stimulate cancer cell proliferation. Their metabolic and developmental effects and growth effects in normal tissues are mediated primarily by nuclear hormone receptors. A cell surface receptor for the hormone on integrin [alpha]vβ3 is the initiation site for effects on tumor cells. Clinical hypothyroidism may retard cancer growth, and hyperthyroidism was recently linked to the prevalence of certain cancers. Local levels of thyroid hormones are controlled through activation and deactivation of iodothyronine deiodinases in different organs. The relative activities of different deiodinases that exist in tissues or organs also affect the progression and development of specific types of cancers. In this review, the effects of thyroid hormone on signaling pathways in breast, brain, liver, thyroid, and colon cancers are discussed. The importance of nuclear thyroid hormone receptor isoforms and of the hormone receptor on the extracellular domain of integrin [alpha]vβ3 as potential cancer risk factors and therapeutic targets are addressed. We analyze the intracellular signaling pathways activated by thyroid hormones in cancer progression in hyperthyroidism or at physiological concentrations in the euthyroid state. Determining how to utilize the deaminated thyroid hormone analog (tetrac), and its nanoparticulate derivative to reduce risks of cancer progression, enhance therapeutic outcomes, and prevent cancer recurrence is also deliberated. © 2016 American Physiological Society. Compr Physiol 6:1221-1237, 2016. Copyright © 2016 John Wiley & Sons, Inc.

Prostate-Derived Ets Transcription Factor Overexpression is Associated with Nodal Metastasis, Hormone Receptor Positivity in Invasive Breast Cancer

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Simon Turcotte

2007-10-01

Full Text Available Prostate-derived Ets transcription factor (PDEF has recently been associated with invasive breast cancer, but no expression profile has been defined in clinical specimens. We undertook a comprehensive PDEF transcriptional expression study of 86 breast cancer clinical specimens, several cell lines, normal tissues. PDEF expression profile was analyzed according to standard clinicopathologic parameters, compared with hormonal receptor, HER-2/neu status, to the expression of the new tumor biomarker Dikkopf-1 (DKK1. Wide ranging PDEF overexpression was observed in 74% of tested tumors, at higher levels than the average expression found in normal breasts. High PDEF expression was associated with hormone receptor positivity (P < .001, moderate to good differentiation (less than grade III, P = .01, dissemination to axillary lymph nodes (P = .002. PDEF was an independent risk factor for nodal involvement (multivariate analysis, odds ratio 1.250, P = .002. It was expressed in a different subgroup compared to DKK1-expressing tumors (P < .001. Our data imply that PDEF mRNA expression could be useful in breast cancer molecular staging. Further insights into PDEF functions at the protein level, possible links with hormone receptors biology, bear great potential for new therapeutic avenues.

Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

Energy Technology Data Exchange (ETDEWEB)

Beildeck, Marcy E. [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States); Gelmann, Edward P. [Columbia University, Department of Medicine, New York, NY (United States); Byers, Stephen W., E-mail: byerss@georgetown.edu [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States)

2010-07-01

Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

International Nuclear Information System (INIS)

Beildeck, Marcy E.; Gelmann, Edward P.; Byers, Stephen W.

2010-01-01

Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

A hormone pulse induces transient changes in the subcellular distribution and leads to a lysosomal accumulation of the estradiol receptor alpha in target tissues.

Science.gov (United States)

Qualmann, B; Kessels, M M; Thole, H H; Sierralta, W D

2000-06-01

An intrauterine pulse-stimulation with estradiol induced changes in the subcellular localization of estrogen receptor alpha in porcine endometrium, as detected with F(ab') fragments of various anti-receptor antibodies covalently linked to nanogold. The low-sterically hindered immunoreagents--recognizing different epitopes within the hormone binding domain--allowed for an efficient immunolabeling of estradiol receptor alpha, detecting it both in the cytoplasm and the nucleus of nonstimulated epithelium cells. In the cytoplasm, the receptor often seemed to be associated with actin filaments and the endoplasmatic reticulum. After the stimulation with estradiol, a predominantly nuclear localization and a labeling of nucleoli was observed. Our immunoelectron microscopy study demonstrates a localization of the receptor in cytoplasmic organelles that increased after the hormone pulse. These organelles exhibited the morphological properties of lysosomes and relocated to the perinuclear area. In analogous cytoplasmic organelles, the presence of cathepsin D was detected via indirect immunogold labeling, justifying their classification as lysosomes. Quantitative examinations revealed that not only the number of lysosomes in the proximity of the nucleus but also their immunostaining for estradiol receptor alpha increased significantly after the hormone pulse. Thus, estradiol induces both the rapid shift of receptor into the nucleus, a slower perinuclear accumulation of lysosomes and an increase of lysosomal ERalpha-immunoreactivity. These results suggest a role for lysosomes in the degradation of receptor shuttling out of the nucleus. This could serve as termination of the estradiol receptor alpha-dependent activation of target cells. This hypothesis is strengthened by the fact that the receptor content in uterine tissue declined drastically few hours after the hormone pulse.

Luteinizing hormone-releasing hormone inactivation by purified pituitary plasma membranes: effects of receptor-binding studies.

Science.gov (United States)

Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C

1979-05-01

Inactivation of LHRH by purified bovine pituitary plasma membranes was studied in vitro. After incubation of [125I]iodo-LHRH with plasma membranes, the amount of tracer bound to the pellet was measured, and the integrity of the unbound tracer in the supernatant was assessed. Reduction in ability to bind to anti-LHRH serum and to rebind to plasma membranes together with altered electrophoretic mobility on polyacrylamide gels showed that the unbound [125I]iodo-LHRH was inactivated. LHRH inactivation occurred rapidly and was dependent upon membrane concentration and incubation temperature. These results indicate that hormone inactivation must be taken into account in the interpretation of LHRH-receptor interactions. During 37 C incubations, the apparent absence of specific LHRH binding can be explained by inactivation of tracer hormone. Significant LHRH inactivation also occurred at 0 C, which in part explains the insensitivity of LHRH receptor assays. Assessment of LHRH inactivation by different particulate subcellular fractions of pituitary tissue showed that the inactivating enzyme was associated with the plasma membranes; other organelles did not alter LHRH. The enzyme appeared to be an integral part of the plasma membrane structure, since enzymic activity could not be removed by washing without reducing specific LHRH binding. Additionally, reduction of LHRH inactivation by the inhibitors Bacitracin and Trasylol and by magnesium was also accompanied by reduced LHRH binding. Previous studies have shown that the majority of LHRH binding to pituitary plasma membranes is to the low affinity site (approximately 10(-6) M), but the significance of this binding has been uncertain. Our findings indicate that low affinity binding probably represents binding of LHRH to the inactivating enzyme. The LHRH analog, D-Ser6(TBu), des Gly10, ethylamide, has greater biological activity than LHRH and is not inactivated to a significant extent by pituitary plasma membranes. The

Low concentrations of bisphenol a suppress thyroid hormone receptor transcription through a nongenomic mechanism

International Nuclear Information System (INIS)

Sheng, Zhi-Guo; Tang, Yuan; Liu, Yu-Xiang; Yuan, Ye; Zhao, Bao-Quan; Chao, Xi-Juan; Zhu, Ben-Zhan

2012-01-01

Bisphenol (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Various rodent and in vitro studies have shown that thyroid hormone (TH) function can be impaired by BPA. However, it is still unknown if low concentrations of BPA can suppress the thyroid hormone receptor (TR) transcription. The present study aims to investigate the possible suppressing effects of low concentrations of BPA on TR transcription and the involved mechanism(s) in CV-1 cells derived from cercopithecus aethiops monkey kidneys. Using gene reporter assays, BPA at concentrations as low as 10 −9 M suppresses TR or steroid receptor coactivator-1(SRC-1)-enhanced TR transcription, but not reducing TR/SRC-1 interaction in mammalian two-hybrid and glutathione S-transferase pull-down studies. It has been further shown that both nuclear receptor co-repressor (N-CoR) and silencing mediator for retinoid and thyroid hormone receptors (SMRT) are recruited to the TR-β1 by BPA in the presence of physiologic concentrations of T3 or T4. However, the overexpression of β3 integrin or c-Src significantly reduces BPA-induced recruitment of N-CoR/SMRT to TR or suppression of TR transcription. Furthermore, BPA inhibits the T3/T4-mediated interassociation of the β3 integrin/c-Src/MAPK/TR-β1 pathways by the co-immunoprecipitation. These results indicate that low concentrations of BPA suppress the TR transcription by disrupting physiologic concentrations of T3/T4-mediated β3 integrin/c-Src/MAPK/TR-β1 pathways, followed by recruiting N-CoR/SMRT to TR-β1, providing a novel insight regarding the TH disruption effects of low concentration BPA. -- Highlights: ► Environmentally relevant concentrations of BPA suppress TR transcription. ► BPA recruits the N-CoR/SMRT to TR under the physiologic concentrations of T3/T4. ► BPA disrupts T3/T4-mediated β3 integrin/c-Src/MAPK/TR-β1 pathways.

Low concentrations of bisphenol a suppress thyroid hormone receptor transcription through a nongenomic mechanism

Energy Technology Data Exchange (ETDEWEB)

Sheng, Zhi-Guo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Tang, Yuan [Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, 30 Yanzheng Street, Chongqing 400038 (China); Liu, Yu-Xiang [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Yuan, Ye; Zhao, Bao-Quan [Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850 (China); Chao, Xi-Juan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu, Ben-Zhan, E-mail: bzhu@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

2012-02-15

Bisphenol (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Various rodent and in vitro studies have shown that thyroid hormone (TH) function can be impaired by BPA. However, it is still unknown if low concentrations of BPA can suppress the thyroid hormone receptor (TR) transcription. The present study aims to investigate the possible suppressing effects of low concentrations of BPA on TR transcription and the involved mechanism(s) in CV-1 cells derived from cercopithecus aethiops monkey kidneys. Using gene reporter assays, BPA at concentrations as low as 10{sup −9} M suppresses TR or steroid receptor coactivator-1(SRC-1)-enhanced TR transcription, but not reducing TR/SRC-1 interaction in mammalian two-hybrid and glutathione S-transferase pull-down studies. It has been further shown that both nuclear receptor co-repressor (N-CoR) and silencing mediator for retinoid and thyroid hormone receptors (SMRT) are recruited to the TR-β1 by BPA in the presence of physiologic concentrations of T3 or T4. However, the overexpression of β3 integrin or c-Src significantly reduces BPA-induced recruitment of N-CoR/SMRT to TR or suppression of TR transcription. Furthermore, BPA inhibits the T3/T4-mediated interassociation of the β3 integrin/c-Src/MAPK/TR-β1 pathways by the co-immunoprecipitation. These results indicate that low concentrations of BPA suppress the TR transcription by disrupting physiologic concentrations of T3/T4-mediated β3 integrin/c-Src/MAPK/TR-β1 pathways, followed by recruiting N-CoR/SMRT to TR-β1, providing a novel insight regarding the TH disruption effects of low concentration BPA. -- Highlights: ► Environmentally relevant concentrations of BPA suppress TR transcription. ► BPA recruits the N-CoR/SMRT to TR under the physiologic concentrations of T3/T4. ► BPA disrupts T3/T4-mediated β3 integrin/c-Src/MAPK/TR-β1 pathways.

Site-specific PEGylation of human thyroid stimulating hormone to prolong duration of action.

Science.gov (United States)

Qiu, Huawei; Boudanova, Ekaterina; Park, Anna; Bird, Julie J; Honey, Denise M; Zarazinski, Christine; Greene, Ben; Kingsbury, Jonathan S; Boucher, Susan; Pollock, Julie; McPherson, John M; Pan, Clark Q

2013-03-20

Recombinant human thyroid stimulating hormone (rhTSH or Thyrogen) has been approved for thyroid cancer diagnostics and treatment under a multidose regimen due to its short circulating half-life. To reduce dosing frequency, PEGylation strategies were explored to increase the duration of action of rhTSH. Lysine and N-terminal PEGylation resulted in heterogeneous product profiles with 40% or lower reaction yields of monoPEGylated products. Eleven cysteine mutants were designed based on a structure model of the TSH-TSH receptor (TSHR) complex to create unique conjugation sites on both α and β subunits for site-specific conjugation. Sequential screening of mutant expression level, oligomerization tendency, and conjugation efficiency resulted in the identification of the αG22C rhTSH mutant for stable expression and scale-up PEGylation. The introduced cysteine in the αG22C rhTSH mutant was partially blocked when isolated from conditioned media and could only be effectively PEGylated after mild reduction with cysteine. This produced a higher reaction yield, ~85%, for the monoPEGylated product. Although the mutation had no effect on receptor binding, PEGylation of αG22C rhTSH led to a PEG size-dependent decrease in receptor binding. Nevertheless, the 40 kDa PEG αG22C rhTSH showed a prolonged duration of action compared to rhTSH in a rat pharmacodynamics model. Reverse-phase HPLC and N-terminal sequencing experiments confirmed site-specific modification at the engineered Cys 22 position on the α-subunit. This work is another demonstration of successful PEGylation of a cysteine-knot protein by an engineered cysteine mutation.

Theoretical Analysis of Allosteric and Operator Binding for Cyclic-AMP Receptor Protein Mutants

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Einav, Tal; Duque, Julia; Phillips, Rob

2018-02-01

Allosteric transcription factors undergo binding events both at their inducer binding sites as well as at distinct DNA binding domains, and it is often difficult to disentangle the structural and functional consequences of these two classes of interactions. In this work, we compare the ability of two statistical mechanical models - the Monod-Wyman-Changeux (MWC) and the Koshland-N\\'emethy-Filmer (KNF) models of protein conformational change - to characterize the multi-step activation mechanism of the broadly acting cyclic-AMP receptor protein (CRP). We first consider the allosteric transition resulting from cyclic-AMP binding to CRP, then analyze how CRP binds to its operator, and finally investigate the ability of CRP to activate gene expression. In light of these models, we examine data from a beautiful recent experiment that created a single-chain version of the CRP homodimer, thereby enabling each subunit to be mutated separately. Using this construct, six mutants were created using all possible combinations of the wild type subunit, a D53H mutant subunit, and an S62F mutant subunit. We demonstrate that both the MWC and KNF models can explain the behavior of all six mutants using a small, self-consistent set of parameters. In comparing the results, we find that the MWC model slightly outperforms the KNF model in the quality of its fits, but more importantly the parameters inferred by the MWC model are more in line with structural knowledge of CRP. In addition, we discuss how the conceptual framework developed here for CRP enables us to not merely analyze data retrospectively, but has the predictive power to determine how combinations of mutations will interact, how double mutants will behave, and how each construct would regulate gene expression.

The C'-terminal interaction domain of the thyroid hormone receptor confers the ability of the DNA site to dictate positive or negative transcriptional activity

International Nuclear Information System (INIS)

Holloway, J.M.; Glass, C.K.; Adler, S.; Nelson, C.A.; Rosenfeld, M.G.

1990-01-01

To investigate mechanisms responsible for positive and negative transcriptional control, the authors have utilized two types of promoters that are diffferentially regulated by thyroid hormone (T 3 ) receptors. Promoters containing the palindromic T 3 response element TCAGGTCA TGACCTGA are positively regulated by the T 3 receptor after the administration of T 3 , whereas otherwise identical promoters containing the estrogen response element TCAGGTCA CTG TGACCTGA can be regulated negatively; converse effects are observed with the estrogen receptor. They describe evidence that the transcriptional inhibitory effects of the T 3 or estrogen receptors on the estrogen or T 3 response elements, respectively, are imposed by amino acid sequences in the C'-terminal region that colocalize with dimerization and hormone-binding domains and that these sequences can transfer inhibitory functions to other classes of transcription factors. Removal of the C'-terminal dimerization and hormone-binding domains of either the αT 3 or estrogen receptors permits each receptor to act constitutively to enhance transcription on both T 3 and estrogen response elements. It is, therefore, suggested that protein-protein interactions between receptor C' termini limit the subset of DNA binding sites on which transcriptional activation occurs

17-AAG increases autophagic removal of mutant androgen receptor in spinal and bulbar muscular atrophy.

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Rusmini, Paola; Simonini, Francesca; Crippa, Valeria; Bolzoni, Elena; Onesto, Elisa; Cagnin, Monica; Sau, Daniela; Ferri, Nicola; Poletti, Angelo

2011-01-01

Several types of motorneuron diseases are linked to neurotoxic mutant proteins. These acquire aberrant conformations (misfolding) that trigger deleterious downstream events responsible for neuronal dysfunction and degeneration. The pharmacological removal of misfolded proteins might thus be useful in these diseases. We utilized a peculiar motorneuronal disease model, spinobulbar muscular atrophy (SBMA), in which the neurotoxicity of the protein involved, the mutant androgen receptor (ARpolyQ), can be modulated by its ligand testosterone (T). 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) has already been proven to exert beneficial action in SBMA. Here we demonstrated that 17-AAG exerts its pro-degradative activity on mutant ARpolyQ without impacting on proteasome functions. 17-AAG removes ARpolyQ misfolded species and aggregates by activating the autophagic system. We next analyzed the 17-AAG effects on two proteins (SOD1 and TDP-43) involved in related motorneuronal diseases, such as amyotrophic lateral sclerosis (ALS). In these models 17-AAG was unable to counteract protein aggregation. Copyright © 2010 Elsevier Inc. All rights reserved.

Corticotropin-Releasing Hormone Receptor Type 1 (CRHR1 Clustering with MAGUKs Is Mediated via Its C-Terminal PDZ Binding Motif.

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Julia Bender

Full Text Available The corticotropin-releasing hormone receptor type 1 (CRHR1 plays an important role in orchestrating neuroendocrine, behavioral, and autonomic responses to stress. To identify molecules capable of directly modulating CRHR1 signaling, we performed a yeast-two-hybrid screen using the C-terminal intracellular tail of the receptor as bait. We identified several members of the membrane-associated guanylate kinase (MAGUK family: postsynaptic density protein 95 (PSD95, synapse-associated protein 97 (SAP97, SAP102 and membrane associated guanylate kinase, WW and PDZ domain containing 2 (MAGI2. CRHR1 is co-expressed with the identified MAGUKs and with the additionally investigated PSD93 in neurons of the adult mouse brain and in primary hippocampal neurons, supporting the probability of a physiological interaction in vivo. The C-terminal PDZ (PSD-95, discs large, zona occludens 1 binding motif of CRHR1 is essential for its physical interaction with MAGUKs, as revealed by the CRHR1-STAVA mutant, which harbors a functionally impaired PDZ binding motif. The imitation of a phosphorylation at Thr413 within the PDZ binding motif also disrupted the interaction with MAGUKs. In contrast, distinct PDZ domains within the identified MAGUKs are involved in the interactions. Expression of CRHR1 in primary neurons demonstrated its localization throughout the neuronal plasma membrane, including the excitatory post synapse, where the receptor co-localized with PSD95 and SAP97. The co-expression of CRHR1 and respective interacting MAGUKs in HEK293 cells resulted in a clustered subcellular co-localization which required an intact PDZ binding motif. In conclusion, our study characterized the PDZ binding motif-mediated interaction of CRHR1 with multiple MAGUKs, which directly affects receptor function.

Action of Specific Thyroid Hormone Receptor alpha(1) and beta(1) Antagonists in the Central and Peripheral Regulation of Thyroid Hormone Metabolism in the Rat

NARCIS (Netherlands)

van Beeren, Hermina C.; Kwakkel, Joan; Ackermans, Mariëtte T.; Wiersinga, Wilmar M.; Fliers, Eric; Boelen, Anita

2012-01-01

Background: The iodine-containing drug amiodarone (Amio) and its noniodine containing analogue dronedarone (Dron) are potent antiarrhythmic drugs. Previous in vivo and in vitro studies have shown that the major metabolite of Amio, desethylamiodarone, acts as a thyroid hormone receptor (TR) alpha(1)

The role of nuclear hormone receptors in cutaneous wound repair.

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Rieger, Sandra; Zhao, Hengguang; Martin, Paige; Abe, Koichiro; Lisse, Thomas S

2015-01-01

The cutaneous wound repair process involves balancing a dynamic series of events ranging from inflammation, oxidative stress, cell migration, proliferation, survival and differentiation. A complex series of secreted trophic factors, cytokines, surface and intracellular proteins are expressed in a temporospatial manner to restore skin integrity after wounding. Impaired initiation, maintenance or termination of the tissue repair processes can lead to perturbed healing, necrosis, fibrosis or even cancer. Nuclear hormone receptors (NHRs) in the cutaneous environment regulate tissue repair processes such as fibroplasia and angiogenesis. Defects in functional NHRs and their ligands are associated with the clinical phenotypes of chronic non-healing wounds and skin endocrine disorders. The functional relationship between NHRs and skin niche cells such as epidermal keratinocytes and dermal fibroblasts is pivotal for successful wound closure and permanent repair. The aim of this review is to delineate the cutaneous effects and cross-talk of various nuclear receptors upon injury towards functional tissue restoration. Copyright © 2014 John Wiley & Sons, Ltd.

Genetic polymorphisms and protein structures in growth hormone, growth hormone receptor, ghrelin, insulin-like growth factor 1 and leptin in Mehraban sheep.

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Bahrami, A; Behzadi, Sh; Miraei-Ashtiani, S R; Roh, S-G; Katoh, K

2013-09-15

The somatotropic axis, the control system for growth hormone (GH) secretion and its endogenous factors involved in the regulation of metabolism and energy partitioning, has promising potentials for producing economically valuable traits in farm animals. Here we investigated single nucleotide polymorphisms (SNPs) of the genes of factors involved in the somatotropic axis for growth hormone (GH1), growth hormone receptor (GHR), ghrelin (GHRL), insulin-like growth factor 1 (IGF-I) and leptin (LEP), using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods in 452 individual Mehraban sheep. A nonradioactive method to allow SSCP detection was used for genomic DNA and PCR amplification of six fragments: exons 4 and 5 of GH1; exon 10 of GH receptor (GHR); exon 1 of ghrelin (GHRL); exon 1 of insulin-like growth factor-I (IGF-I), and exon 3 of leptin (LEP). Polymorphisms were detected in five of the six PCR products. Two electrophoretic patterns were detected for GH1 exon 4. Five conformational patterns were detected for GH1 exon 5 and LEP exon 3, and three for IGF-I exon 1. Only GHR and GHRL were monomorphic. Changes in protein structures due to variable SNPs were also analyzed. The results suggest that Mehraban sheep, a major breed that is important for the animal industry in Middle East countries, has high genetic variability, opening interesting prospects for future selection programs and preservation strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

Arabidopsis CPR5 regulates ethylene signaling via molecular association with the ETR1 receptor.

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Wang, Feifei; Wang, Lijuan; Qiao, Longfei; Chen, Jiacai; Pappa, Maria Belen; Pei, Haixia; Zhang, Tao; Chang, Caren; Dong, Chun-Hai

2017-11-01

The plant hormone ethylene plays various functions in plant growth, development and response to environmental stress. Ethylene is perceived by membrane-bound ethylene receptors, and among the homologous receptors in Arabidopsis, the ETR1 ethylene receptor plays a major role. The present study provides evidence demonstrating that Arabidopsis CPR5 functions as a novel ETR1 receptor-interacting protein in regulating ethylene response and signaling. Yeast split ubiquitin assays and bi-fluorescence complementation studies in plant cells indicated that CPR5 directly interacts with the ETR1 receptor. Genetic analyses indicated that mutant alleles of cpr5 can suppress ethylene insensitivity in both etr1-1 and etr1-2, but not in other dominant ethylene receptor mutants. Overexpression of Arabidopsis CPR5 either in transgenic Arabidopsis plants, or ectopically in tobacco, significantly enhanced ethylene sensitivity. These findings indicate that CPR5 plays a critical role in regulating ethylene signaling. CPR5 is localized to endomembrane structures and the nucleus, and is involved in various regulatory pathways, including pathogenesis, leaf senescence, and spontaneous cell death. This study provides evidence for a novel regulatory function played by CPR5 in the ethylene receptor signaling pathway in Arabidopsis. © 2017 Institute of Botany, Chinese Academy of Sciences.

Quantification of three steroid hormone receptors of the leopard gecko (Eublepharis macularius), a lizard with temperature-dependent sex determination: their tissue distributions and the effect of environmental change on their expressions.

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Endo, Daisuke; Park, Min Kyun

2003-12-01

Sex steroid hormones play a central role in the reproduction of all vertebrates. These hormones function through their specific receptors, so the expression levels of the receptors may reflect the responsibility of target organs. However, there was no effective method to quantify the expression levels of these receptors in reptilian species. In this study, we established the competitive-PCR assay systems for the quantification of the mRNA expression levels of three sex steroid hormone receptors in the leopard gecko. These assay systems were successfully able to detect the mRNA expression level of each receptor in various organs of male adult leopard geckoes. The expression levels of mRNA of these receptors were highly various depending on the organs assayed. This is the first report regarding the tissue distributions of sex steroid hormone receptor expressions in reptile. The effects of environmental conditions on these hormone receptor expressions were also examined. After the low temperature and short photoperiod treatment for 6 weeks, only the androgen receptor expression was significantly increased in the testes. The competitive-PCR assay systems established in this report should be applicable for various studies of the molecular mechanism underlying the reproductive activity of the leopard gecko.

Microsomal receptor for steroid hormones: functional implications for nuclear activity.

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Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

1988-01-01

Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of

Identification of tyrosine residues in the intracellular domain of the growth hormone receptor required for transcriptional signaling and Stat5 activation

DEFF Research Database (Denmark)

Hansen, L. H.; Wang, X.; Kopchick, J J

1996-01-01

The binding of growth hormone (GH) to its receptor results in its dimerization followed by activation of Jak2 kinase and tyrosine phosphorylation of the GH receptor itself, as well as Jak2 and the transcription factors Stat1, -3, and -5. In order to study the role of GH receptor tyrosine phosphor...

Trialkyltin rexinoid-X receptor agonists selectively potentiate thyroid hormone induced programs of xenopus laevis metamorphosis

NARCIS (Netherlands)

Mengeling, Brenda J.; Murk, Albertinka J.; Furlow, J.D.

2016-01-01

The trialkyltins tributyltin (TBT) and triphenyltin (TPT) can function as rexinoid-X receptor (RXR) agonists. We recently showed that RXR agonists can alter thyroid hormone (TH) signaling in a mammalian pituitary TH-responsive reporter cell line, GH3.TRE-Luc. The prevalence of TBT and TPT in the

A novel growth hormone receptor gene deletion mutation in a patient with primary growth hormone insensitivity syndrome (Laron syndrome).

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Yamamoto, Hiroyasu; Kouhara, Haruhiko; Iida, Keiji; Chihara, Kazuo; Kasayama, Soji

2008-04-01

Growth hormone (GH) insensitivity syndrome (Laron syndrome) is known to be caused by genetic disorders of the GH-IGF-1 axis. Although many mutations in the GH receptor have been identified, there have been only a few reports of deletions of the GH receptor gene. A Japanese adult female patient with Laron syndrome was subjected to chromosome analysis with basic G-banding and also with a high accuracy technique. Each exon of the GH receptor gene was amplified by means of PCR. Since this patient was diagnosed with osteoporosis, the effects of alendronate on bone mineral density (BMD) were also examined. The chromosome analysis with the high accuracy technique demonstrated a large deletion of the short arm in one allele of chromosome 5 from p11 to p13.1 [46, XX, del (5) (p11-p13.1)]. PCR amplification of exons of the GH receptor gene showed that only exons 2 and 3 were amplified. Low-dose IGF-1 administration (30microg/kg body weight) failed to increase her BMD, whereas alendronate administration resulted in an increase associated with a decrease in urinary deoxypyridinoline (DPD) and serum osteocalcin concentrations. The GH receptor gene of the patient was shown to lack exons 4-10. To the best of our knowledge, this is the third case report of Laron syndrome with large GH receptor deletion. Alendronate was effective for the enhancement of BMD.

Melanin-concentrating hormone and its receptor are expressed and functional in human skin.

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Hoogduijn, Martin J; Ancans, Janis; Suzuki, Itaru; Estdale, Siân; Thody, Anthony J

2002-08-23

In this study, we have demonstrated the presence of melanin-concentrating hormone (MCH) and melanin-concentrating hormone receptor (MCHR1) transcripts in human skin. Sequence analysis confirmed that the transcripts of both genes were identical to those previously found in human brain. In culture, endothelial cells showed pro-MCH expression whereas no signal was found in keratinocytes, melanocytes, and fibroblasts. MCHR1 expression was restricted to melanocytes and melanoma cells. Stimulation of cultured human melanocytes with MCH reduced the alpha-MSH-induced increase in cAMP production. Furthermore, the melanogenic actions of alpha-MSH were inhibited by MCH. We propose that the MCH/MCHR1 signalling system is present in human skin and may have a role with the melanocortins in regulating the melanocyte.

Neurotrophins and their receptors in the rat pituitary gland: regulation of BDNF and trkB mRNA levels by adrenal hormones.

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Kononen, J; Soinila, S; Persson, H; Honkaniemi, J; Hökfelt, T; Pelto-Huikko, M

1994-12-01

We studied the expression of messenger ribonucleic acids (mRNAs) for neurotrophins and neurotrophin receptors in the rat pituitary gland and examined the influence of adrenal hormones on their mRNA levels, using in situ hybridization and Northern blot analysis. The only neurotrophin present at detectable levels in the pituitary was brain-derived neurotrophic factor (BDNF), which was observed in the anterior and intermediate lobes. Several transcripts of the putative receptor for BDNF, trkB, were present in the anterior and posterior lobes of the pituitary. A low amount of trkC mRNA was found in both the anterior and the intermediate lobe. Dexamethasone treatment decreased both BDNF and trkB mRNA levels in the anterior lobe of the pituitary. Adrenalectomy had no effect on trkB expression, but it decreased BDNF mRNA levels in comparison to the control animals. This effect could not be reversed by dexamethasone substitution, suggesting that BDNF, mRNA levels may be regulated not only by glucocorticoids but also by other adrenal hormones. These results demonstrate that BDNF, trkB and trkC are expressed in the pituitary gland and that glucocorticoids and possibly other adrenal hormones may modulate pituitary functions by regulating the expression of neurotrophic factors and their receptors. Whether BDNF acts as a secreted hormone, a trophic factor, or has autocrine/paracrine functions within the pituitary through its receptor, trkB, remains to be studied.

Mutations and polymorphisms in FSH receptor: functional implications in human reproduction.

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Desai, Swapna S; Roy, Binita Sur; Mahale, Smita D

2013-12-01

FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.

The Neuroendocrine Functions of the Parathyroid Hormone 2 Receptor

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Arpad eDobolyi

2012-10-01

Full Text Available The G-protein coupled parathyroid hormone 2 receptor (PTH2R is concentrated in endocrine and limbic regions in the forebrain. Its endogenous ligand,tuberoinfundibular peptide of 39 residues (TIP39, is synthesized in only 2 brain regions, within the posterior thalamus and the lateral pons. TIP39-expressing neurons have a widespread projection pattern, which matches the PTH2R distribution in the brain. Neuroendocrine centers including the preoptic area, the periventricular, paraventricular, and arcuate nuclei contain the highest density of PTH2R-positive networks. The administration of TIP39 and an antagonist of the PTH2R as well as the investigation of mice that lack functional TIP39 and PTH2R revealed the involvement of the PTH2R in a variety of neural and neuroendocrine functions. TIP39 acting via the PTH2R modulates several aspects of the stress response. It evokes corticosterone release by activating corticotropin-releasing hormone-containing neurons in the hypothalamic paraventricular nucleus. Block of TIP39 signaling elevates the anxiety state of animals and their fear response, and increases stress-induced analgesia. TIP39 has also been suggested to affect the release of additional pituitary hormones including arginine vasopressin and growth hormone. A role of the TIP39-PTH2R system in thermoregulation was also identified. TIP39 may play a role in maintaining body temperature in a cold environment via descending excitatory pathways from the preoptic area. Anatomical and functional studies also implicated the TIP39-PTH2R system in nociceptive information processing. Finally, TIP39 induced in postpartum dams may play a role in the release of prolactin during lactation. Potential mechanisms leading to the activation of TIP39 neurons and how they influence the neuroendocrine system are also described. The unique TIP39-PTH2R neuromodulator system provides the possibility for developing drugs with a novel mechanism of action to control

Characterization of hormonal receptors and human epidermal growth factor receptor-2 in tissues of women with breast cancer at Muhimbili National Hospital, Dar es salaam, Tanzania.

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Mwakigonja, Amos Rodger; Lushina, Nyanda Elias; Mwanga, Ally

2017-01-01

Breast cancer is a leading cause of morbidity and deaths among women worldwide. In Tanzania there is no published data on human epidermal growth receptor-2 (HER2/neu) expression in breast carcinoma. Hormonal receptors and HER2/neu status reportedly influence post-mastectomy adjuvant therapy and predict treatment outcome and prognosis. Here we evaluate hormonal receptors and HER-2 status in biopsies of women with breast cancer at Muhimbili National Hospital (MNH). A cross-sectional study of female breast post-modified radical mastectomy (MRM)/incisional biopsies confirmed to be carcinoma at the Histopathology Unit (January-December 2013). Tissue blocks having poor morphology, without tumor, secondary tumors, cases outside the study period and male patients were excluded. Routine staining was done followed by immunohistochemistry for estrogen (ER), and progesterone (PgR) receptors and HER2. Data analyzed using Statistical Package for Social Sciences (SPSS). A total of 218 cases were confirmed to be carcinoma including 70 meeting inclusion criteria. Age at diagnosis ranged 18-75 years and mean age was 48.36 years. Majority (64.3%) were in the 36-55 years age-group. Histologically, most (88.6%) women had invasive ductal carcinoma including 43.1% of intermediate grade. A great majority (78%) were stage three. Due to logistical constrains, 75.7% ( n  = 53/70) cases where immunostained for hormones including 43.4% (ER+), 26.4% (PgR+), and 28% (ER+/PgR+). Furthermore, 65.7% ( n  = 46/70) cases were immunostained for HER-2 and 15.2% ( n  = 7/46) were positive, 45.6% were triple negative (ER-,PgR-,HER2-), 23.9% (ER+,PgR+,HER2-) or luminal B, 2.2% (ER+,PgR-,HER2+),13% (ER-,PgR-,HER2+) and 15% (ER+,PgR-,HER2-) with none being triple positive. Hormonal receptors and HER2 expression at MNH appears to be comparable to previous Africans/African Americans reports but not with studies among Caucasians and the current proportion of triple negative breast carcinomas (TNBC) is

Characterization of hormonal receptors and human epidermal growth factor receptor-2 in tissues of women with breast cancer at Muhimbili National Hospital, Dar es salaam, Tanzania

Directory of Open Access Journals (Sweden)

Amos Rodger Mwakigonja

2017-11-01

Full Text Available Abstract Background Breast cancer is a leading cause of morbidity and deaths among women worldwide. In Tanzania there is no published data on human epidermal growth receptor-2 (HER2/neu expression in breast carcinoma. Hormonal receptors and HER2/neu status reportedly influence post-mastectomy adjuvant therapy and predict treatment outcome and prognosis. Here we evaluate hormonal receptors and HER-2 status in biopsies of women with breast cancer at Muhimbili National Hospital (MNH. Methods A cross-sectional study of female breast post-modified radical mastectomy (MRM/incisional biopsies confirmed to be carcinoma at the Histopathology Unit (January–December 2013. Tissue blocks having poor morphology, without tumor, secondary tumors, cases outside the study period and male patients were excluded. Routine staining was done followed by immunohistochemistry for estrogen (ER, and progesterone (PgR receptors and HER2. Data analyzed using Statistical Package for Social Sciences (SPSS. Results A total of 218 cases were confirmed to be carcinoma including 70 meeting inclusion criteria. Age at diagnosis ranged 18–75 years and mean age was 48.36 years. Majority (64.3% were in the 36–55 years age-group. Histologically, most (88.6% women had invasive ductal carcinoma including 43.1% of intermediate grade. A great majority (78% were stage three. Due to logistical constrains, 75.7% (n = 53/70 cases where immunostained for hormones including 43.4% (ER+, 26.4% (PgR+, and 28% (ER+/PgR+. Furthermore, 65.7% (n = 46/70 cases were immunostained for HER-2 and 15.2% (n = 7/46 were positive, 45.6% were triple negative (ER-,PgR-,HER2-, 23.9% (ER+,PgR+,HER2- or luminal B, 2.2% (ER+,PgR-,HER2+,13% (ER-,PgR-,HER2+ and 15% (ER+,PgR-,HER2- with none being triple positive. Conclusions Hormonal receptors and HER2 expression at MNH appears to be comparable to previous Africans/African Americans reports but not with studies among Caucasians and the current proportion

Synthesis and in vitro anti-cancer evaluation of luteinizing hormone-releasing hormone-conjugated peptide.

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Deng, Xin; Qiu, Qianqian; Ma, Ke; Huang, Wenlong; Qian, Hai

2015-11-01

Luteinizing hormone-releasing hormone (LHRH) is a decapeptide hormone released from the hypothalamus and shows high affinity binding to the LHRH receptors. It is reported that several cancer cells also express LHRH receptors such as breast, ovarian, prostatic, bladder and others. In this study, we linked B1, an anti-cancer peptide, to LHRH and its analogs to improve the activity against cancer cells with LHRH receptor. Biological evaluation revealed that TB1, the peptide contains triptorelin sequence, present favorable anti-cancer activity as well as plasma stability. Further investigations disclosed that TB1 trigger apoptosis by activating the mitochondria-cytochrome c-caspase apoptotic pathway, it also exhibited the anti-migratory effect on cancer cells.

Glycine receptor mutants of the mouse: what are possible routes of inhibitory compensation?

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Natascha eSchaefer

2012-10-01

Full Text Available Defects in glycinergic inhibition result in a complex neuromotor disorder in humans known as hyperekplexia (OMIM 149400 with similar phenotypes in rodents characterized by an exaggerated startle reflex and hypertonia. Analogous to genetic defects in humans, single point mutations, microdeletions, or insertions in the Glra1 gene but also in the Glrb gene underlie the pathology in mice. The mutations either localized in the α (spasmodic, oscillator, cincinnati, Nmf11 or the β (spastic subunit of the GlyR are much less tolerated in mice than in humans, leaving the question for the existence of different regulatory elements of the pathomechanisms in humans and rodents. In addition to the spontaneous mutations, new insights into understanding of the regulatory pathways in hyperekplexia or glycine encephalopathy arose from the constantly increasing number of knock-out as well as knock-in mutants of GlyRs. Over the last five years, various efforts using in vivo whole cell recordings provided a detailed analysis of the kinetic parameters underlying glycinergic dysfunction. Presynaptic compensation as well as postsynaptic compensatory mechanisms in these mice by other GlyR subunits or GABAA receptors, and the role of extra-synaptic GlyRs is still a matter of debate. A recent study on the mouse mutant oscillator, displayed a novel aspect for compensation of functionality by complementation of receptor domains that fold independently. This review focuses on defects in glycinergic neurotransmission in mice discussed with the background of human hyperekplexia en route to strategies of compensation.

The effect of the intracervical application of follicle-stimulating hormone or luteinizing hormone on the pattern of expression of gonadotrophin receptors in the cervix of non-pregnant ewes.

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Leethongdee, S; Khalid, M; Scaramuzzi, R J

2014-08-01

During the periovulatory period, the cervix relaxes in response to changes in circulating concentrations of reproductive hormones. The present study investigated the role of gonadotrophins in cervical function by examining the expression of follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) and their mRNAs following intracervical treatment with either FSH or LH. Eighteen ewes were assigned to four groups, and they were then treated with progestagen sponges and PMSG to synchronize their oestrous cycles. Intracervical treatments were given 24 h after sponge removal as follows: Group 1: FSH 2 mg; Group 2: LH 2 mg; Group 3: Vehicle and Group 4: Control. Cervices were collected 54 h after sponge removal and then divided into three regions. The expression of FSHR and LHR was determined by immunohistochemistry and FSHR mRNA and LH mRNA by in situ hybridization. The expression of LHR, FSHR and their respective mRNAs was compared in six tissue layers (luminal epithelium, subepithelial stroma, circular, longitudinal and transverse muscle and serosa) and in three cervical regions (vaginal, mid and uterine). The results showed that FSH increased transcription of the FSHR gene and the levels of its receptor, but only in subepithelial stroma of the cervix. FSH also increased the levels of LHR in the cervix, but only in the muscle layers. LH had no effect on the levels of FSHR despite the fact that it did increase the level of transcription of the FSHR gene and LH also increased the levels of its own receptor in the cervix, but only in the muscle layers, and this action was independent of increased levels of transcription of the LHR gene. These findings suggest multiple levels of regulation of cervical LH and FSH receptors and that the gonadotrophins may have a role in relaxation of the cervix during oestrus by regulating their own receptors. © 2014 Blackwell Verlag GmbH.

Characterization of pituitary growth hormone and its receptor in the green iguana (Iguana iguana).

Science.gov (United States)

Ávila-Mendoza, José; Carranza, Martha; Pérez-Rueda, Ernesto; Luna, Maricela; Arámburo, Carlos

2014-07-01

Pituitary growth hormone (GH) has been studied in most vertebrate groups; however, only a few studies have been carried out in reptiles. Little is known about pituitary hormones in the order Squamata, to which the green iguana (gi) belongs. In this work, we characterized the hypophysis of Iguana iguana morphologically. The somatotrophs (round cells of 7.6-10 μm containing 250- to 300-nm secretory granules where the giGH is stored) were found, by immunohistochemistry and in situ hybridization, exclusively in the caudal lobe of the pars distalis, whereas the lactotrophs were distributed only in the rostral lobe. A pituitary giGH-like protein was obtained by immuno-affinity chromatography employing a heterologous antibody against chicken GH. giGH showed molecular heterogeneity (22, 44, and 88 kDa by SDS-PAGE/Western blot under non-reducing conditions and at least four charge variants (pIs 6.2, 6.5, 6.9, 7.4) by isoelectric focusing. The pituitary giGH cDNA (1016 bp), amplified by PCR and RACE, encodes a pre-hormone of 218 aa, of which 190 aa correspond to the mature protein and 28 aa to the signal peptide. The giGH receptor cDNA was also partially sequenced. Phylogenetic analyses of the amino acid sequences of giGH and giGHR homologs in vertebrates suggest a parallel evolution and functional relationship between the GH and its receptor. Copyright © 2014 Elsevier Inc. All rights reserved.

Pegvisomant: a growth hormone receptor antagonist used in the treatment of acromegaly.

Science.gov (United States)

Tritos, Nicholas A; Biller, Beverly M K

2017-02-01

To review published data on pegvisomant and its therapeutic role in acromegaly. Electronic searches of the published literature were conducted using the keywords: acromegaly, growth hormone (GH) receptor (antagonist), pegvisomant, therapy. Relevant articles (n = 141) were retrieved and considered for inclusion in this manuscript. Pegvisomant is a genetically engineered, recombinant growth hormone receptor antagonist, which is effective in normalizing serum insulin-like growth factor 1 (IGF-1) levels in the majority of patients with acromegaly and ameliorating symptoms and signs associated with GH excess. Pegvisomant does not have direct antiproliferative effects on the underlying somatotroph pituitary adenoma, which is the etiology of GH excess in the vast majority of patients with acromegaly. Therefore, patients receiving pegvisomant monotherapy require regular pituitary imaging in order to monitor for possible increase in tumor size. Adverse events in patients on pegvisomant therapy include skin rashes, lipohypertrophy at injection sites, and idiosyncratic liver toxicity (generally asymptomatic transaminitis that is reversible upon drug discontinuation), thus necessitating regular patient monitoring. Pegvisomant is an effective therapeutic agent in patients with acromegaly who are not in remission after undergoing pituitary surgery. It mitigates excess GH action, as demonstrated by IGF-1 normalization, but has no direct effects on pituitary tumors causing acromegaly. Regular surveillance for possible tumor growth and adverse effects (hepatotoxicity, skin manifestations) is warranted.

Effect of thyrotrophin releasing hormone on opiate receptors of the rat brain

Energy Technology Data Exchange (ETDEWEB)

Balashov, A.M.; Shchurin, M.R.

1987-01-01

It has recently been shown that the hypothalamic thyrotropin releasing hormone (TRH) has the properties of a morphine antagonist, blocking its inhibitory action on respiration and, to a lesser degree, its analgesic action. This suggests that the antagonistic effects of TRH are mediated through its interaction with opiate receptors. The aim of this paper is to study this hypothesis experimentally. Tritium-labelled enkephalins in conjunction with scintillation spectroscopy were used to assess the receptor binding behavior. The results indicate the existence of interconnections between the opiate systems and TRH. Although it is too early to reach definite conclusions on the mechanisms of this mutual influence and its physiological significance it can be tentatively suggested that TRH abolishes the pharmacological effects of morphine by modulating the functional state of opiate reception.

Growth hormone secretagogue receptor (GHS-R1a) knockout mice exhibit improved spatial memory and deficits in contextual memory.

Science.gov (United States)

Albarran-Zeckler, Rosie G; Brantley, Alicia Faruzzi; Smith, Roy G

2012-06-15

Although the hormone ghrelin is best known for its stimulatory effect on appetite and regulation of growth hormone release, it is also reported to have beneficial effects on learning and memory formation in mice. Nevertheless, controversy exists about whether endogenous ghrelin acts on its receptors in extra-hypothalamic areas of the brain. The ghrelin receptor (GHS-R1a) is co-expressed in neurons that express dopamine receptor type-1 (DRD1a) and type-2 (DRD2), and we have shown that a subset of GHS-R1a, which are not occupied by the agonist (apo-GHSR1a), heterodimerize with these two receptors to regulate dopamine signaling in vitro and in vivo. To determine the consequences of ghsr ablation on brain function, congenic ghsr -/- mice on the C57BL6/J background were subjected to a battery of behavioral tests. We show that the ghsr -/- mice exhibit normal balance, movement, coordination, and pain sensation, outperform ghsr +/+ mice in the Morris water maze, but show deficits in contextual fear conditioning. Copyright © 2012 Elsevier B.V. All rights reserved.

[Advanced luminal breast cancer (hormone receptor-positive, HER2 negative): New therapeutic options in 2015].

Science.gov (United States)

Vanacker, Hélène; Bally, Olivia; Kassem, Loay; Tredan, Olivier; Heudel, Pierre; Bachelot, Thomas

2015-06-01

Despite improvements in early detection, surgery and systemic therapy, metastatic breast cancer remains a major cause of death. Luminal type breast cancers expressing hormone estrogen receptor (ER) or progesterone (PR) and without HER2 overexpression are generally sensitive to endocrine therapy, but raise the issue of the occurrence of resistance to treatment, particularly at metastatic stage. A better understanding of hormone resistance may guide the development of new therapeutics. New strategies aim at enhancing and prolonging of endocrine sensitivity, by optimizing existing schemes, or by combining an endocrine therapy with a targeted therapies specific to hormone resistance pathways: ER signaling, PI3K/AKT/mTOR and Cyclin Dependent Kinase (CDK). Key corners of 2014 include confirmation of benefit of high dose fulvestrant, and commercialization of everolimus as the first mTOR inhibitor in this indication. Other strategies are being tested dealing with new endocrine therapies or new molecular targets such as PI3K inhibitors, insulin-like growth factor receptor (IGF-R) and histone deacetylase (HDAC) inhibitors. Coming years may be fruitful and might radically change our way to treat these patients. Copyright © 2015 Société Françise du Cancer. Publié par Elsevier Masson SAS. Tous droits réservés. Published by Elsevier Masson SAS. All rights reserved.

Role of corticosteroid hormones in the dentate gyrus.

NARCIS (Netherlands)

Joëls, M.

2007-01-01

Dentate granule cells are enriched with receptors for the stress hormone corticosterone, i.e., the high-affinity mineralocorticoid receptor (MR), which is already extensively occupied with low levels of the hormone, and the glucocorticoid receptor (GR), which is particularly activated after stress.

Increased melanin concentrating hormone receptor type I in the human hypothalamic infundibular nucleus in cachexia

NARCIS (Netherlands)

Unmehopa, Unga A.; van Heerikhuize, Joop J.; Spijkstra, Wenda; Woods, John W.; Howard, Andrew D.; Zycband, Emanuel; Feighner, Scott D.; Hreniuk, Donna L.; Palyha, Oksana C.; Guan, Xiao-Ming; Macneil, Douglas J.; van der Ploeg, Lex H. T.; Swaab, Dick F.

2005-01-01

Melanin-concentrating hormone (MCH) exerts a positive regulation on appetite and binds to the G protein-coupled receptors, MCH1R and MCH2R. In rodents, MCH is produced by neurons in the lateral hypothalamus with projections to various hypothalamic and other brain sites. In the present study, MCH1R

Increased melanin concentrating hormone receptor type I in the human hypothalamic infundibular nucleus in cachexia.

NARCIS (Netherlands)

Unmehopa, U.A.; Heerikhuize, J.J. van; Spijkstra, W.; Woods, J.W.; Howard, A.D.; Zycband, E.; Feighner, S.D.; Hreniuk, D.L.; Palyha, O.C.; Guan, X.-M.; MacNeil, D.J.; Ploeg, L.H.T.; Swaab, D.F.

2005-01-01

Melanin-concentrating hormone (MCH) exerts a positive regulation on appetite and binds to the G protein-coupled receptors, MCH1R and MCH2R. In rodents, MCH is produced by neurons in the lateral hypothalamus with projections to various hypothalamic and other brain sites. In the present study, MCH1R

Internalization of Rat FSH and LH/CG Receptors by rec-eCG in CHO-K1 Cells.

Science.gov (United States)

Park, Jong-Ju; Seong, Hun-Ki; Kim, Jeong-Soo; Munkhzaya, Byambaragchaa; Kang, Myung-Hwa; Min, Kwan-Sik

2017-06-01

Equine chorionic gonadotropin (eCG) is a unique molecule that elicits the response characteristics of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in other species. Previous studies from this laboratory had demonstrated that recombinant eCG (rec-eCG) from Chinese hamster ovary (CHO-K1) cells exhibited both FSH- and LH-like activity in rat granulosa and Leydig cells. In this study, we analyzed receptor internalization through rec-eCGs, wild type eCG (eCGβ/α) and mutant eCG (eCGβ/αΔ56) with an N-linked oligosaccharide at Asn 56 of the α-subunit. Both the rec-eCGs were obtained from CHO-K1 cells. The agonist activation of receptors was analyzed by measuring stimulation time and concentrations of rec-eCGs. Internalization values in the stably selected rat follicle-stimulating hormone receptor (rFSHR) and rat luteinizing/chorionic gonadotropin receptor (rLH/CGR) were highest at 50 min after stimulation with 10 ng of rec-eCGβ/α. The dose-dependent response was highest when 10 ng of rec-eCGβ/α was used. The deglycosylated eCGβ/αΔ56 mutant did not enhance the agonist-stimulated internalization. We concluded that the state of activation of rFSHR and rLH/CGR could be modulated through agonist-stimulated internalization. Our results suggested that the eLH/CGRs are mostly internalized within 60 min by agonist-stimulation by rec-eCG. We also suggested that the lack of responsiveness of the deglycosylated eCGβ/ αΔ56 was likely because the site of glycosylation played a pivotal role in agonist-stimulated internalization in cells expressing rFSHR and rLH/CGR.

Hormone Receptor Expression Analyses in Neoplastic and Non-Neoplastic Canine Mammary Tissue by a Bead Based Multiplex Branched DNA Assay: A Gene Expression Study in Fresh Frozen and Formalin-Fixed, Paraffin-Embedded Samples.

Directory of Open Access Journals (Sweden)

Annika Mohr

Full Text Available Immunohistochemistry (IHC is currently considered the method of choice for steroid hormone receptor status evaluation in human breast cancer and, therefore, it is commonly utilized for assessing canine mammary tumors. In case of low hormone receptor expression, IHC is limited and thus is complemented by molecular analyses. In the present study, a multiplex bDNA assay was evaluated as a method for hormone receptor gene expression detection in canine mammary tissues. Estrogen receptor (ESR1, progesterone receptor (PGR, prolactin receptor (PRLR and growth hormone receptor (GHR gene expressions were evaluated in neoplastic and non-neoplastic canine mammary tissues. A set of 119 fresh frozen and 180 formalin-fixed, paraffin-embedded (FFPE was comparatively analyzed and used for assay evaluation. Furthermore, a possible association between the hormone receptor expression in different histological subtypes of canine malignant mammary tumors and the castration status, breed and invasive growth of the tumor were analyzed. The multiplex bDNA assay proved to be more sensitive for fresh frozen specimens. Hormone receptor expression found was significantly decreased in malignant mammary tumors in comparison to non-neoplastic tissue and benign mammary tumors. Among the histological subtypes the lowest gene expression levels of ESR1, PGR and PRLR were found in solid, anaplastic and ductal carcinomas. In summary, the evaluation showed that the measurement of hormone receptors with the multiplex bDNA assay represents a practicable method for obtaining detailed quantitative information about gene expression in canine mammary tissue for future studies. Still, comparison with IHC or quantitative real-time PCR is needed for further validation of the present method.

Novel growth hormone receptor mutation in a Chinese patient with Laron syndrome.

Science.gov (United States)

Hui, Hamilton N T; Metherell, Louise A; Ng, K L; Savage, Martin O; Camacho-Hübner, Cecilia; Clark, Adrian J L

2005-02-01

Laron syndrome, growth hormone (GH) insensitivity syndrome, caused by a mutation of the GH receptor (GHR) gene, is extremely rare in the Chinese population. We report a Chinese girl diagnosed with Laron syndrome at age 1.9 years with height -4.9 SDS, basal GH 344 mIU/ml, IGF-I <12 ng/ml, IGFBP-3 <0.2 mg/ml, and undetectable GHBP. A novel mutation of the GHR, not previously described, was identified at the donor splice site of intron 6.

Identification of a novel mutation in the human growth hormone receptor gene (GHR) in a patient with Laron syndrome.

Science.gov (United States)

Gennero, Isabelle; Edouard, Thomas; Rashad, Mona; Bieth, Eric; Conte-Aurio, Françoise; Marin, Françoise; Tauber, Maithé; Salles, Jean Pierre; El Kholy, Mohamed

2007-07-01

Deletions and mutations in the growth hormone receptor (GHR) gene are the underlying etiology of Laron syndrome (LS) or growth hormone (GH) insensitivity syndrome (GHIS), an autosomal recessive disease. Most patients are distributed in or originate from Mediterranean and Middle-Eastern countries. Sixty mutations have been described so far. We report a novel mutation in the GHR gene in a patient with LS. Genomic DNA sequencing of exon 5 revealed a TT insertion at nucleotide 422 after codon 122. The insertion resulted in a frameshift introducing a premature termination codon that led to a truncated receptor. We present clinical, biochemical and molecular evidence of LS as the result of this homozygous insertion.

Transcriptomic and phenotypic profiling in developing zebrafish exposed to thyroid hormone receptor agonists

Energy Technology Data Exchange (ETDEWEB)

Haggard, Derik E.; Noyes, Pamela D.; Waters, Katrina M.; Tanguay, Robert L.

2018-04-01

There is a need to develop novel, high-throughput screening and prioritization methods to identify chemicals with adverse estrogen, androgen, and thyroid activity to protect human health and the environment and is of interest to the Endocrine Disruptor Screening Program. The current aim is to explore the utility of zebrafish as a testing paradigm to classify endocrine activity using phenotypically anchored transcriptome profiling. Transcriptome analysis was conducted on embryos exposed to 25 estrogen-, androgen-, or thyroid-active chemicals at a concentration that elicited adverse malformations or mortality at 120 hours post-fertilization in 80% of the animals exposed. Analysis of the top 1000 significant differentially expressed transcripts across all treatments identified a unique transcriptional and phenotypic profile for thyroid hormone receptor agonists, which can be used as a biomarker screen for potential thyroid hormone agonists.

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

OpenAIRE

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2006-01-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnR...

Resistance to thyroid hormone due to defective thyroid receptor alpha.

Science.gov (United States)

Moran, Carla; Chatterjee, Krishna

2015-08-01

Thyroid hormones act via nuclear receptors (TRα1, TRβ1, TRβ2) with differing tissue distribution; the role of α2 protein, derived from the same gene locus as TRα1, is unclear. Resistance to thyroid hormone alpha (RTHα) is characterised by tissue-specific hypothyroidism associated with near-normal thyroid function tests. Clinical features include dysmorphic facies, skeletal dysplasia (macrocephaly, epiphyseal dysgenesis), growth retardation, constipation, dyspraxia and intellectual deficit. Biochemical abnormalities include low/low-normal T4 and high/high-normal T3 concentrations, a subnormal T4/T3 ratio, variably reduced reverse T3, raised muscle creatine kinase and mild anaemia. The disorder is mediated by heterozygous, loss-of-function, mutations involving either TRα1 alone or both TRα1 and α2, with no discernible phenotype attributable to defective α2. Whole exome sequencing and diagnostic biomarkers may enable greater ascertainment of RTHα, which is important as thyroxine therapy reverses some metabolic abnormalities and improves growth, constipation, dyspraxia and wellbeing. The genetic and phenotypic heterogeneity of RTHα and its optimal management remain to be elucidated. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

An ochre mutation in the vitamin D receptor gene causes hereditary 1,25-dihydroxyvitamin D3-resistant rickets in three families

International Nuclear Information System (INIS)

Ritchie, H.H.; Hughes, M.R.; Thompson, E.T.; Pike, J.W.; O'Malley, B.W.; Malloy, P.J.; Feldman, D.; Hochberg, Z.

1989-01-01

Hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets is a rare autosomal-recessive disease resulting from target-organ resistance to the action of the active hormonal form of vitamin D. Four affected children from three related families with the classical syndrome of hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets and the absence of detectable binding to the vitamin D receptor (VDR) in cultured fibroblasts or lymphoblasts were examined for genetic abnormalities in the VDR gene. Genomic DNA from Epstein-Barr virus-transformed lymphoblasts of eight family members was isolated and amplified by polymerase chain reaction techniques. Amplified fragments containing the eight structural exons encoding the VDR protein were sequenced. The DNA from all affected children exhibited a single C → A base substitution within exon 7 at nucleotide 970. Although the affected children were all homozygotic for the mutation, the four parents tested all exhibited both wild-type and mutant alleles, indicating a heterozygous state. Recreated mutant receptor exhibited no specific 1,25-[ 3 H]dihydroxyvitamin D 3 binding and failed to activate a cotransfected VDR promoter-reporter gene construct. Thus these findings identify an ochre mutation in a human steroid hormone receptor in patients with hereditary 1,25-dihydroxyvitamin D 3 -resistant rickets

Silencing neuronal mutant androgen receptor in a mouse model of spinal and bulbar muscular atrophy.

Science.gov (United States)

Sahashi, Kentaro; Katsuno, Masahisa; Hung, Gene; Adachi, Hiroaki; Kondo, Naohide; Nakatsuji, Hideaki; Tohnai, Genki; Iida, Madoka; Bennett, C Frank; Sobue, Gen

2015-11-01

Spinal and bulbar muscular atrophy (SBMA), an adult-onset neurodegenerative disease that affects males, results from a CAG triplet repeat/polyglutamine expansions in the androgen receptor (AR) gene. Patients develop progressive muscular weakness and atrophy, and no effective therapy is currently available. The tissue-specific pathogenesis, especially relative pathological contributions between degenerative motor neurons and muscles, remains inconclusive. Though peripheral pathology in skeletal muscle caused by toxic AR protein has been recently reported to play a pivotal role in the pathogenesis of SBMA using mouse models, the role of motor neuron degeneration in SBMA has not been rigorously investigated. Here, we exploited synthetic antisense oligonucleotides to inhibit the RNA levels of mutant AR in the central nervous system (CNS) and explore its therapeutic effects in our SBMA mouse model that harbors a mutant AR gene with 97 CAG expansions and characteristic SBMA-like neurogenic phenotypes. A single intracerebroventricular administration of the antisense oligonucleotides in the presymptomatic phase efficiently suppressed the mutant gene expression in the CNS, and delayed the onset and progression of motor dysfunction, improved body weight gain and survival with the amelioration of neuronal histopathology in motor units such as spinal motor neurons, neuromuscular junctions and skeletal muscle. These findings highlight the importance of the neurotoxicity of mutant AR protein in motor neurons as a therapeutic target. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The little women of Loja--growth hormone-receptor deficiency in an inbred population of southern Ecuador.

Science.gov (United States)

Rosenbloom, A L; Guevara Aguirre, J; Rosenfeld, R G; Fielder, P J

1990-11-15

Laron-type dwarfism, which is characterized by the clinical appearance of isolated growth hormone deficiency with elevated serum levels of growth hormone and decreased serum levels of insulin-like growth factor I (IGF-I), has been described in approximately 50 patients. This condition is caused by a deficiency of the cellular receptor for growth hormone, and it is transmitted as an autosomal recessive trait, as indicated by an equal sex distribution and a high rate of consanguinity in affected families. We studied 20 patients (19 females and 1 male, 2 to 49 years of age), from an inbred Spanish population in southern Ecuador, who had the clinical features of Laron-type dwarfism. Seventeen patients were members of two large pedigrees. Among the 13 affected sibships, there were 19 affected and 24 unaffected female siblings and 1 affected and 21 unaffected male siblings. The patients' heights ranged from 10.0 to 6.7 SD below the normal mean height for age in the United States. In addition to the previously described features, 15 patients had limited elbow extensibility, all had blue scleras, affected adults had relatively short extremities, and all four affected women over 30 years of age had hip degeneration. Basal serum concentrations of growth hormone were elevated in all affected children (30 to 160 micrograms per liter) and normal to moderately elevated in the adults. The serum level of growth hormone-binding protein ranged from 1 to 30 percent of normal; IGF-I concentrations were low--less than or equal to 7 micrograms per liter in the children and less than or equal to 66 micrograms per liter in the adults (normal for Ecuadorean women, 98 to 238). Serum levels of IGF-II and growth hormone-dependent IGF-binding protein-3 were also low. We describe an inbred population with a high incidence of growth hormone-receptor deficiency resulting in a clinical picture resembling Laron-type dwarfism but differing principally in showing a marked predominance of affected

A growth hormone receptor SNP promotes lung cancer by impairment of SOCS2-mediated degradation

DEFF Research Database (Denmark)

Chhabra, Y.; Wong, H. Y.; Nikolajsen, Louise Fletcher

2018-01-01

Both humans and mice lacking functional growth hormone (GH) receptors are known to be resistant to cancer. Further, autocrine GH has been reported to act as a cancer promoter. Here we present the first example of a variant of the GH receptor (GHR) associated with cancer promotion, in this case lu......-mesenchymal transition and metastases (TWIST1, SNAI2, EGFR, MYC and CCND1) at 2 h after a GH pulse. This is consistent with prolonged GH signalling acting to promote cancer progression in lung cancer.Oncogene advance online publication, 2 October 2017; doi:10.1038/onc.2017.352....

Review of hormonal treatment of breast cancer | Abdulkareem ...

African Journals Online (AJOL)

This critical review focuses on the role of steroid hormones and their receptors in the development and treatment of breast cancer, with special reference to estrogen receptors, as well as mechanisms of receptor.ligand interactions, response or resistance to hormonal therapy against breast cancer, in conjunction with other ...

Effects of Asn318 and Asp87Asn318 mutations on signal transduction by the gonadotropin-releasing hormone receptor and receptor regulation.

Science.gov (United States)

Awara, W M; Guo, C H; Conn, P M

1996-02-01

GnRH receptor (GnRH-R) contains Asn87 and Asp318 instead of the more frequently observed Asp87 and Asn318 found in other G protein-coupled receptors. In the present study, site-directed mutagenesis was used to introduce Asn318 and Asp87Asn318 into GnRH-R. The effect on coupling and regulation of GnRH-R was studied by stable expression of wild and mutant mouse GnRH-R in the lactotropic GH3 cells; these normally release PRL in response to TRH stimulation. The responses to Buserelin (a metabolically stable GnRH analog) in three different cell lines, M1, N8, and ND1 (expressing wild-type, Asn318 mutant, and Asp87Asn318 mutant mouse GnRH-R, respectively) were compared with that observed in the previously characterized GGH3-1' cells, which stably express rat GnRH-R. The Asn318 and Asp87Asn318 mutations had no measurable effect on ligand binding, but abolished the initial down-regulation of receptor that was observed in M1 and GGH3-1' cells, suggesting that the normal location of Asn87 and Asp318 in GnRH-R is involved in the regulation of GnRH-R. In N8 and ND1 cells, Buserelin-stimulated inositol phosphate (IP) production was attenuated, but the release of both cAMP and PRL was stimulated in a dose- and time-dependent manner. These mutations apparently impaired the coupling between GnRH-R and G proteins involved in IP production, but not those involved in cAMP release. In M1 cells, Buserelin stimulation produced a significant increase in IP production, but neither cAMP nor PRL release was significantly stimulated. These findings are consistent with the previous suggestion that GnRH-stimulated PRL release is mediated by a cAMP second messenger system in transfected GGH3 cells.

Neuronal M3 muscarinic acetylcholine receptors are essential for somatotroph proliferation and normal somatic growth.

Science.gov (United States)

Gautam, Dinesh; Jeon, Jongrye; Starost, Matthew F; Han, Sung-Jun; Hamdan, Fadi F; Cui, Yinghong; Parlow, Albert F; Gavrilova, Oksana; Szalayova, Ildiko; Mezey, Eva; Wess, Jürgen

2009-04-14

The molecular pathways that promote the proliferation and maintenance of pituitary somatotrophs and other cell types of the anterior pituitary gland are not well understood at present. However, such knowledge is likely to lead to the development of novel drugs useful for the treatment of various human growth disorders. Although muscarinic cholinergic pathways have been implicated in regulating somatotroph function, the physiological relevance of this effect and the localization and nature of the receptor subtypes involved in this activity remain unclear. We report the surprising observation that mutant mice that selectively lack the M(3) muscarinic acetylcholine receptor subtype in the brain (neurons and glial cells; Br-M3-KO mice) showed a dwarf phenotype associated with a pronounced hypoplasia of the anterior pituitary gland and a marked decrease in pituitary and serum growth hormone (GH) and prolactin. Remarkably, treatment of Br-M3-KO mice with CJC-1295, a synthetic GH-releasing hormone (GHRH) analog, rescued the growth deficit displayed by Br-M3-KO mice by restoring normal pituitary size and normal serum GH and IGF-1 levels. These findings, together with results from M(3) receptor/GHRH colocalization studies and hypothalamic hormone measurements, support a model in which central (hypothalamic) M(3) receptors are required for the proper function of hypothalamic GHRH neurons. Our data reveal an unexpected and critical role for central M(3) receptors in regulating longitudinal growth by promoting the proliferation of pituitary somatotroph cells.

An ochre mutation in the vitamin D receptor gene causes hereditary 1,25-dihydroxyvitamin D sub 3 -resistant rickets in three families

Energy Technology Data Exchange (ETDEWEB)

Ritchie, H.H.; Hughes, M.R.; Thompson, E.T.; Pike, J.W.; O' Malley, B.W. (Baylor College of Medicine, Houston, TX (USA)); Malloy, P.J.; Feldman, D. (Stanford Univ. School of Medicine, CA (USA)); Hochberg, Z. (Rambam Medical Center, Haifa (Israel))

1989-12-01

Hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets is a rare autosomal-recessive disease resulting from target-organ resistance to the action of the active hormonal form of vitamin D. Four affected children from three related families with the classical syndrome of hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets and the absence of detectable binding to the vitamin D receptor (VDR) in cultured fibroblasts or lymphoblasts were examined for genetic abnormalities in the VDR gene. Genomic DNA from Epstein-Barr virus-transformed lymphoblasts of eight family members was isolated and amplified by polymerase chain reaction techniques. Amplified fragments containing the eight structural exons encoding the VDR protein were sequenced. The DNA from all affected children exhibited a single C {yields} A base substitution within exon 7 at nucleotide 970. Although the affected children were all homozygotic for the mutation, the four parents tested all exhibited both wild-type and mutant alleles, indicating a heterozygous state. Recreated mutant receptor exhibited no specific 1,25-({sup 3}H)dihydroxyvitamin D{sub 3} binding and failed to activate a cotransfected VDR promoter-reporter gene construct. Thus these findings identify an ochre mutation in a human steroid hormone receptor in patients with hereditary 1,25-dihydroxyvitamin D{sub 3}-resistant rickets.

Relationship between the functional exon 3 deleted growth hormone receptor polymorphism and symptomatic osteoarthritis in women

NARCIS (Netherlands)

Claessen, K. M. J. A.; Kloppenburg, M.; Kroon, H. M.; Bijsterbosch, J.; Pereira, A. M.; Romijn, J. A.; van der Straaten, T.; Nelissen, R. G. H. H.; Hofman, A.; Uitterlinden, A. G.; Duijnisveld, B. J.; Lakenberg, N.; Beekman, M.; van Meurs, J. B.; Slagboom, P. E.; Biermasz, N. R.; Meulenbelt, I.

2014-01-01

Background Several studies suggest a role of the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis in the pathophysiology of primary osteoarthritis (OA). A common polymorphism of the GH receptor (exon 3 deletion, d3-GHR) is associated with increased GH/IGF-1 activity. Objective To study

Crystal structure of an affinity-matured prolactin complexed to its dimerized receptor reveals the topology of hormone binding site 2

DEFF Research Database (Denmark)

Broutin, Isabelle; Jomain, Jean-Baptiste; Tallet, Estelle

2010-01-01

We report the first crystal structure of a 1:2 hormone.receptor complex that involves prolactin (PRL) as the ligand, at 3.8-A resolution. Stable ternary complexes were obtained by generating affinity-matured PRL variants harboring an N-terminal tail from ovine placental lactogen, a closely relate...... and prostate cancer.......We report the first crystal structure of a 1:2 hormone.receptor complex that involves prolactin (PRL) as the ligand, at 3.8-A resolution. Stable ternary complexes were obtained by generating affinity-matured PRL variants harboring an N-terminal tail from ovine placental lactogen, a closely related...... PRL receptor (PRLR) ligand. This structure allows one to draw up an exhaustive inventory of the residues involved at the PRL.PRLR site 2 interface, consistent with all previously reported site-directed mutagenesis data. We propose, with this description, an interaction model involving three structural...

Zebrafish bandoneon mutants display behavioral defects due to a mutation in the glycine receptor β-subunit

Science.gov (United States)

Hirata, Hiromi; Saint-Amant, Louis; Downes, Gerald B.; Cui, Wilson W.; Zhou, Weibin; Granato, Michael; Kuwada, John Y.

2005-01-01

Bilateral alternation of muscle contractions requires reciprocal inhibition between the two sides of the hindbrain and spinal cord, and disruption of this inhibition should lead to simultaneous activation of bilateral muscles. At 1 day after fertilization, wild-type zebrafish respond to mechanosensory stimulation with multiple fast alternating trunk contractions, whereas bandoneon (beo) mutants contract trunk muscles on both sides simultaneously. Similar simultaneous contractions are observed in wild-type embryos treated with strychnine, a blocker of the inhibitory glycine receptor (GlyR). This result suggests that glycinergic synaptic transmission is defective in beo mutants. Muscle voltage recordings confirmed that muscles on both sides of the trunk in beo are likely to receive simultaneous synaptic input from the CNS. Recordings from motor neurons revealed that glycinergic synaptic transmission was missing in beo mutants. Furthermore, immunostaining with an antibody against GlyR showed clusters in wild-type neurons but not in beo neurons. These data suggest that the failure of GlyRs to aggregate at synaptic sites causes impairment of glycinergic transmission and abnormal behavior in beo mutants. Indeed, mutations in the GlyR β-subunit, which are thought to be required for proper localization of GlyRs, were identified as the basis for the beo mutation. These data demonstrate that GlyRβ is essential for physiologically relevant clustering of GlyRs in vivo. Because GlyR mutations in humans lead to hyperekplexia, a motor disorder characterized by startle responses, the zebrafish beo mutant should be a useful animal model for this condition. PMID:15928085

α-Helical element at the hormone-binding surface of the insulin receptor functions as a signaling element to activate its tyrosine kinase.

Science.gov (United States)

Whittaker, Jonathan; Whittaker, Linda J; Roberts, Charles T; Phillips, Nelson B; Ismail-Beigi, Faramarz; Lawrence, Michael C; Weiss, Michael A

2012-07-10

The primary hormone-binding surface of the insulin receptor spans one face of the N-terminal β-helix of the α-subunit (the L1 domain) and an α-helix in its C-terminal segment (αCT). Crystallographic analysis of the free ectodomain has defined a contiguous dimer-related motif in which the αCT α-helix packs against L1 β-strands 2 and 3. To relate structure to function, we exploited expanded genetic-code technology to insert photo-activatable probes at key sites in L1 and αCT. The pattern of αCT-mediated photo-cross-linking within the free and bound receptor is in accord with the crystal structure and prior mutagenesis. Surprisingly, L1 photo-probes in β-strands 2 and 3, predicted to be shielded by αCT, efficiently cross-link to insulin. Furthermore, anomalous mutations were identified on neighboring surfaces of αCT and insulin that impair hormone-dependent activation of the intracellular receptor tyrosine kinase (contained within the transmembrane β-subunit) disproportionately to their effects on insulin binding. Taken together, these results suggest that αCT, in addition to its hormone-recognition role, provides a signaling element in the mechanism of receptor activation.

Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor's Extracellular Hinge Region.

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Grzesik, Paul; Kreuchwig, Annika; Rutz, Claudia; Furkert, Jens; Wiesner, Burkhard; Schuelein, Ralf; Kleinau, Gunnar; Gromoll, Joerg; Krause, Gerd

2015-01-01

The human lutropin (hLH)/choriogonadotropin (hCG) receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG) - secreted by the placenta, and lutropin (LH) - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich-repeat domain (LRRD), as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on hormone-induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10-deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge

Removal of reproductive suppression reveals latent sex differences in brain steroid hormone receptors in naked mole-rats, Heterocephalus glaber.

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Swift-Gallant, Ashlyn; Mo, Kaiguo; Peragine, Deane E; Monks, D Ashley; Holmes, Melissa M

2015-01-01

Naked mole-rats are eusocial mammals, living in large colonies with a single breeding female and 1-3 breeding males. Breeders are socially dominant, and only the breeders exhibit traditional sex differences in circulating gonadal steroid hormones and reproductive behaviors. Non-reproductive subordinates also fail to show sex differences in overall body size, external genital morphology, and non-reproductive behaviors. However, subordinates can transition to breeding status if removed from their colony and housed with an opposite-sex conspecific, suggesting the presence of latent sex differences. Here, we assessed the expression of steroid hormone receptor and aromatase messenger RNA (mRNA) in the brains of males and females as they transitioned in social and reproductive status. We compared in-colony subordinates to opposite-sex subordinate pairs that were removed from their colony for either 1 day, 1 week, 1 month, or until they became breeders (i.e., produced a litter). Diencephalic tissue was collected and mRNA of androgen receptor (Ar), estrogen receptor alpha (Esr1), progesterone receptor (Pgr), and aromatase (Cyp19a1) was measured using qPCR. Testosterone, 17β-estradiol, and progesterone from serum were also measured. As early as 1 week post-removal, males exhibited increased diencephalic Ar mRNA and circulating testosterone, whereas females had increased Cyp19a1 mRNA in the diencephalon. At 1 month post-removal, females exhibited increased 17β-estradiol and progesterone. The largest changes in steroid hormone receptors were observed in breeders. Breeding females had a threefold increase in Cyp19a1 and fivefold increases in Esr1 and Pgr, whereas breeding males had reduced Pgr and increased Ar. These data demonstrate that sex differences in circulating gonadal steroids and hypothalamic gene expression emerge weeks to months after subordinate animals are removed from reproductive suppression in their home colony.

Levels of central oxytocin and glucocorticoid receptor and serum adrenocorticotropic hormone and corticosterone in mandarin voles with different levels of sociability.

Science.gov (United States)

Qiao, Xufeng; Yan, Yating; Tai, Fadao; Wu, Ruiyong; Hao, Ping; Fang, Qianqian; Zhang, Shuwei

2014-11-01

Sociability is the prerequisite to social living. Oxytocin and the hypothalamo-pituitary-adrenocortical axis mediate various social behaviors across different social contexts in different rodents. We hypothesized that they also mediate levels of non-reproductive social behavior. Here we explored naturally occurring variation in sociability through a social preference test and compared central oxytocin, glucocorticoid receptors, serum adrenocorticotropic hormone and corticosterone in mandarin voles with different levels of sociability. We found that low-social voles showed higher levels of anxiety-like behavior in open field tests, and had more serum adrenocorticotropic hormone and corticosterone than high-social voles. High-social individuals had more glucocorticoid receptor positive neurons in the hippocampus and more oxytocin positive neurons in the paraventricular nuclei and supraoptic nuclei of the hypothalamus than low-social individuals. Within the same level of sociability, females had more oxytocin positive neurons in the paraventricular nuclei and supraoptic nuclei of the hypothalamus than males. These results indicate that naturally occurring social preferences are associated with higher levels of central oxytocin and hippocampus glucocorticoid receptor and lower levels of anxiety and serum adrenocorticotropic hormone and corticosterone. Copyright © 2014 Elsevier B.V. All rights reserved.

Fanconi Anemia a Is a Nucleocytoplasmic Shuttling Molecule Required for Gonadotropin-Releasing Hormone (GnRH) Transduction of the GnRH Receptor

OpenAIRE

Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela

2006-01-01

GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR) located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common α- and hormone-specific β-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the LβT2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60%...

Liver X receptor β controls thyroid hormone feedback in the brain and regulates browning of subcutaneous white adipose tissue.

Science.gov (United States)

Miao, Yifei; Wu, Wanfu; Dai, Yubing; Maneix, Laure; Huang, Bo; Warner, Margaret; Gustafsson, Jan-Åke

2015-11-10

The recent discovery of browning of white adipose tissue (WAT) has raised great research interest because of its significant potential in counteracting obesity and type 2 diabetes. Browning is the result of the induction in WAT of a newly discovered type of adipocyte, the beige cell. When mice are exposed to cold or several kinds of hormones or treatments with chemicals, specific depots of WAT undergo a browning process, characterized by highly activated mitochondria and increased heat production and energy expenditure. However, the mechanisms underlying browning are still poorly understood. Liver X receptors (LXRs) are one class of nuclear receptors, which play a vital role in regulating cholesterol, triglyceride, and glucose metabolism. Following our previous finding that LXRs serve as repressors of uncoupling protein-1 (UCP1) in classic brown adipose tissue in female mice, we found that LXRs, especially LXRβ, also repress the browning process of subcutaneous adipose tissue (SAT) in male rodents fed a normal diet. Depletion of LXRs activated thyroid-stimulating hormone (TSH)-releasing hormone (TRH)-positive neurons in the paraventricular nucleus area of the hypothalamus and thus stimulated secretion of TSH from the pituitary. Consequently, production of thyroid hormones in the thyroid gland and circulating thyroid hormone level were increased. Moreover, the activity of thyroid signaling in SAT was markedly increased. Together, our findings have uncovered the basis of increased energy expenditure in male LXR knockout mice and provided support for targeting LXRs in treatment of obesity.

Comparative Functional Alanine Positional Scanning of the α-Melanocyte Stimulating Hormone and NDP-Melanocyte Stimulating Hormone Demonstrates Differential Structure-Activity Relationships at the Mouse Melanocortin Receptors.

Science.gov (United States)

Todorovic, Aleksandar; Ericson, Mark D; Palusak, Ryan D; Sorensen, Nicholas B; Wood, Michael S; Xiang, Zhimin; Haskell-Luevano, Carrie

2016-07-20

The melanocortin system has been implicated in the regulation of various physiological functions including melanogenesis, steroidogenesis, energy homeostasis, and feeding behavior. Five melanocortin receptors have been identified to date and belong to the family of G protein-coupled receptors (GPCR). Post-translational modification of the proopiomelanocortin (POMC) prohormone leads to the biosynthesis of the endogenous melanocortin agonists, including α-melanocyte stimulating hormone (α-MSH), β-MSH, γ-MSH, and adrenocorticotropic hormone (ACTH). All the melanocortin agonists derived from the POMC prohormone contain a His-Phe-Arg-Trp tetrapeptide sequence that has been implicated in eliciting the pharmacological responses at the melanocortin receptors. Herein, an alanine (Ala) positional scan is reported for the endogenous α-MSH ligand and the synthetic, more potent, NDP-MSH peptide (Ac-Ser(1)-Tyr(2)-Ser(3)-Nle(4)-Glu(5)-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-Lys(11)-Pro(12)-Val(13)-NH2) at the cloned mouse melanocortin receptors to test the assumption that the structure-activity relationships of one ligand would apply to the other. Several residues outside of the postulated pharmacophore altered potency at the melanocortin receptors, most notably the 1560-, 37-, and 15-fold potency loss when the Glu(5) position of α-MSH was substituted with Ala at the mMC1R, mMC3R, and mMC4R, respectively. Importantly, the altered potencies due to Ala substitutions in α-MSH did not necessarily correlate with equivalent Ala substitutions in NDP-MSH, indicating that structural modifications and corresponding biological activities in one of these melanocortin ligands may not be predictive for the other agonist.

Receptor-mediated endocytosis of polypeptide hormones is a regulated process: inhibition of [125I]iodoinsulin internalization in hypoinsulinemic diabetes of rat and man

International Nuclear Information System (INIS)

Carpentier, J.L.; Robert, A.; Grunberger, G.; van Obberghen, E.; Freychet, P.; Orci, L.; Gorden, P.

1986-01-01

Much data suggest that receptor-mediated endocytosis is regulated in states of hormone excess. Thus, in hyperinsulinemic states there is an accelerated loss of cell surface insulin receptors. In the present experiments we addressed this question in hypoinsulinemic states, in which insulin binding to cell surface receptors is generally increased. In hepatocytes obtained from hypoinsulinemic streptozotocin-induced diabetic rats, [ 125 I]iodoglucagon internalization was increased, while at the same time [ 125 I]iodoinsulin internalization was decreased. The defect in [ 125 I]iodoinsulin internalization was corrected by insulin treatment of the animal. In peripheral blood monocytes from patients with type I insulinopenic diabetes, internalization of [ 125 I]iodoinsulin was impaired; this defect was not present in insulin-treated patients. These data in the hypoinsulinemic rat and human diabetes suggest that receptor-mediated endocytosis is regulated in states of insulin deficiency as well as insulin excess. Delayed or reduced internalization of the insulin-receptor complex could amplify the muted signal caused by deficient hormone secretion

Nuclear hormone receptor expression in mouse kidney and renal cell lines.

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Daisuke Ogawa

Full Text Available Nuclear hormone receptors (NHRs are transcription factors that regulate carbohydrate and lipid metabolism, immune responses, and inflammation. Although several NHRs, including peroxisome proliferator-activated receptor-γ (PPARγ and PPARα, demonstrate a renoprotective effect in the context of diabetic nephropathy (DN, the expression and role of other NHRs in the kidney are still unrecognized. To investigate potential roles of NHRs in the biology of the kidney, we used quantitative real-time polymerase chain reaction to profile the expression of all 49 members of the mouse NHR superfamily in mouse kidney tissue (C57BL/6 and db/m, and cell lines of mesangial (MES13, podocyte (MPC, proximal tubular epithelial (mProx24 and collecting duct (mIMCD3 origins in both normal and high-glucose conditions. In C57BL/6 mouse kidney cells, hepatocyte nuclear factor 4α, chicken ovalbumin upstream promoter transcription factor II (COUP-TFII and COUP-TFIII were highly expressed. During hyperglycemia, the expression of the NHR 4A subgroup including neuron-derived clone 77 (Nur77, nuclear receptor-related factor 1, and neuron-derived orphan receptor 1 significantly increased in diabetic C57BL/6 and db/db mice. In renal cell lines, PPARδ was highly expressed in mesangial and proximal tubular epithelial cells, while COUP-TFs were highly expressed in podocytes, proximal tubular epithelial cells, and collecting duct cells. High-glucose conditions increased the expression of Nur77 in mesangial and collecting duct cells, and liver x receptor α in podocytes. These data demonstrate NHR expression in mouse kidney cells and cultured renal cell lines and suggest potential therapeutic targets in the kidney for the treatment of DN.

Chromosomal localization of the gonadotropin-releasing hormone receptor gene to human chromosome 4q13. 1-q21. 1 and mouse chromosome 5

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Kaiser, U.B.; Dushkin, H.; Beier, D.R.; Chin, W.W. (Harvard Medical School, Boston, MA (United States)); Altherr, M.R. (Los Alamos National Lab., NM (United States))

1994-04-01

The gonadotropin-releasing hormone receptor (GRHR) is a G-protein-coupled receptor on the cell surface of pituitary gonadotropes, where it serves to transduce signals from the extracellular ligand, the hypothalamic factor gonadotropin-releasing hormone, and to modulate the synthesis and secretion of luteinizing hormone and follicle-stimulating hormone. The authors have localized the GRHR gene to the q13.1-q21.1 region of the human chromosome 4 using mapping panels of human/rodent somatic cell hybrids containing different human chromosomes or different regions of human chromosome 4. Furthermore, using linkage analysis of single-strand conformational polymorphisms, the murine GRHR gene was localized to mouse chromosome 5, linked to the endogenous retroviral marker Pmv-11. This is consistent with the evolutionary conservation of homology between these two regions, as has been previously suggested from comparative mapping of several other loci. The localization of the GRHR gene may be useful in the study of disorders of reproduction. 22 refs., 2 figs.

Altered lipid homeostasis in Drosophila InsP3 receptor mutants leads to obesity and hyperphagia

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Manivannan Subramanian

2013-05-01

Obesity is a complex metabolic disorder that often manifests with a strong genetic component in humans. However, the genetic basis for obesity and the accompanying metabolic syndrome is poorly defined. At a metabolic level, obesity arises from an imbalance between the nutritional intake and energy utilization of an organism. Mechanisms that sense the metabolic state of the individual and convey this information to satiety centers help achieve this balance. Mutations in genes that alter or modify such signaling mechanisms are likely to lead to either obese individuals, who in mammals are at high risk for diabetes and cardiovascular disease, or excessively thin individuals with accompanying health problems. Here we show that Drosophila mutants for an intracellular calcium signaling channel, the inositol 1,4,5-trisphosphate receptor (InsP3R store excess triglycerides in their fat bodies and become unnaturally obese on a normal diet. Although excess insulin signaling can rescue obesity in InsP3R mutants to some extent, we show that it is not the only cause of the defect. Through mass spectrometric analysis of lipids we find that homeostasis of storage and membrane lipids are altered in InsP3R mutants. Possibly as a compensatory mechanism, InsP3R mutant adults also feed excessively. Thus, reduced InsP3R function alters lipid metabolism and causes hyperphagia in adults. Together, the metabolic and behavioral changes lead to obesity. Our results implicate altered InsP3 signaling as a previously unknown causative factor for metabolic syndrome in humans. Importantly, our studies also suggest preventive dietary interventions.

GAR22: A novel target gene of thyroid hormone receptor causes growth inhibition in human erythroid cells

Czech Academy of Sciences Publication Activity Database

Gamper, I.; Koh, K.-R.; Ruau, D.; Ullrich, K.; Bartůňková, Jana; Piroth, D.; Hacker, C.; Bartůněk, Petr; Zenke, M.

2009-01-01

Roč. 37, č. 5 (2009), s. 539-548 ISSN 0301-472X R&D Projects: GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z50520514 Keywords : Thyroid hormone receptor * GAR22 * erythropoiesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.106, year: 2009

Growth hormone-specific induction of the nuclear localization of porcine growth hormone receptor in porcine hepatocytes.

Science.gov (United States)

Lan, H N; Hong, P; Li, R N; Shan, A S; Zheng, X

2017-10-01

The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat, and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR's nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR's nuclear localization were analyzed and demonstrated that pGHR's nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR's nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, whereas further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal. Copyright © 2017 Elsevier Inc. All rights reserved.

Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V.

1989-01-01

Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer and prostate cancer cell lines in vitro. Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides

Thyroid hormones upregulate apolipoprotein E gene expression in astrocytes

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Roman, Corina; Fuior, Elena V.; Trusca, Violeta G. [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania); Kardassis, Dimitris [University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, Crete (Greece); Simionescu, Maya [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania); Gafencu, Anca V., E-mail: anca.gafencu@icbp.ro [Institute of Cellular Biology and Pathology “Nicolae Simionescu”, Bucharest (Romania)

2015-12-04

Apolipoprotein E (apoE), a protein mainly involved in lipid metabolism, is associated with several neurodegenerative disorders including Alzheimer's disease. Despite numerous attempts to elucidate apoE gene regulation in the brain, the exact mechanism is still uncovered. The mechanism of apoE gene regulation in the brain involves the proximal promoter and multienhancers ME.1 and ME.2, which evolved by gene duplication. Herein we questioned whether thyroid hormones and their nuclear receptors have a role in apoE gene regulation in astrocytes. Our data showed that thyroid hormones increase apoE gene expression in HTB14 astrocytes in a dose-dependent manner. This effect can be intermediated by the thyroid receptor β (TRβ) which is expressed in these cells. In the presence of triiodothyronine (T3) and 9-cis retinoic acid, in astrocytes transfected to overexpress TRβ and retinoid X receptor α (RXRα), apoE promoter was indirectly activated through the interaction with ME.2. To determine the location of TRβ/RXRα binding site on ME.2, we performed DNA pull down assays and found that TRβ/RXRα complex bound to the region 341–488 of ME.2. This result was confirmed by transient transfection experiments in which a series of 5′- and 3′-deletion mutants of ME.2 were used. These data support the existence of a biologically active TRβ binding site starting at 409 in ME.2. In conclusion, our data revealed that ligand-activated TRβ/RXRα heterodimers bind with high efficiency on tissue-specific distal regulatory element ME.2 and thus modulate apoE gene expression in the brain. - Highlights: • T3 induce a dose-dependent increase of apoE expression in astrocytes. • Thyroid hormones activate apoE promoter in a cell specific manner. • Ligand activated TRβ/RXRα bind on the distal regulatory element ME.2 to modulate apoE. • The binding site of TRβ/RXRα heterodimer is located at 409 bp on ME.2.

Thyroid hormones upregulate apolipoprotein E gene expression in astrocytes

International Nuclear Information System (INIS)

Roman, Corina; Fuior, Elena V.; Trusca, Violeta G.; Kardassis, Dimitris; Simionescu, Maya; Gafencu, Anca V.

2015-01-01

Apolipoprotein E (apoE), a protein mainly involved in lipid metabolism, is associated with several neurodegenerative disorders including Alzheimer's disease. Despite numerous attempts to elucidate apoE gene regulation in the brain, the exact mechanism is still uncovered. The mechanism of apoE gene regulation in the brain involves the proximal promoter and multienhancers ME.1 and ME.2, which evolved by gene duplication. Herein we questioned whether thyroid hormones and their nuclear receptors have a role in apoE gene regulation in astrocytes. Our data showed that thyroid hormones increase apoE gene expression in HTB14 astrocytes in a dose-dependent manner. This effect can be intermediated by the thyroid receptor β (TRβ) which is expressed in these cells. In the presence of triiodothyronine (T3) and 9-cis retinoic acid, in astrocytes transfected to overexpress TRβ and retinoid X receptor α (RXRα), apoE promoter was indirectly activated through the interaction with ME.2. To determine the location of TRβ/RXRα binding site on ME.2, we performed DNA pull down assays and found that TRβ/RXRα complex bound to the region 341–488 of ME.2. This result was confirmed by transient transfection experiments in which a series of 5′- and 3′-deletion mutants of ME.2 were used. These data support the existence of a biologically active TRβ binding site starting at 409 in ME.2. In conclusion, our data revealed that ligand-activated TRβ/RXRα heterodimers bind with high efficiency on tissue-specific distal regulatory element ME.2 and thus modulate apoE gene expression in the brain. - Highlights: • T3 induce a dose-dependent increase of apoE expression in astrocytes. • Thyroid hormones activate apoE promoter in a cell specific manner. • Ligand activated TRβ/RXRα bind on the distal regulatory element ME.2 to modulate apoE. • The binding site of TRβ/RXRα heterodimer is located at 409 bp on ME.2.

Differential Expression of Claudin Family Proteins in Mouse Ovarian Serous Papillary Epithelial Adenoma in Aging FSH Receptor-Deficient Mutants

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Jayaprakash Aravindakshan

2006-12-01

Full Text Available Ovarian cancer is a deadly disease with long latency. To understand the consequences of loss of folliclestimulating hormone receptor (FSH-R signaling and to explore why the atrophic and anovulatory ovaries of follitropin receptor knockout (FORKO mice develop different types of ovarian tumors, including serous papillary epithelial adenoma later in life, we used mRNA expression profiling to gain a comprehensive view of misregulated genes. Using real-time quantitative reverse transcription-polymerase chain reaction, protein analysis, and cellular localization, we show, for the first time, in vivo evidence that, in the absence of FSH-R signaling, claudin-3, claudin-4, and claudin-11 are selectively upregulated, whereas claudin-1 decreases in ovarian surface epithelium and tumors in comparison to wild type. In vitro experiments using a mouse ovarian surface epithelial cell line derived from wild-type females reveal direct hormonal influence on claudin proteins. Although recent studies suggest that cell junction proteins are differentially expressed in ovarian tumors in women, the etiology of such changes remains unclear. Our results suggest an altered hormonal environment resulting from FSH-R loss as a cause of early changes in tight junction proteins that predispose the ovary to late-onset tumors that occur with aging. More importantly, this study identifies claudin-11 overexpression in mouse ovarian serous cystadenoma.

Evaluation of Therapy Management and Patient Compliance in Postmenopausal Patients with Hormone Receptor-positive Breast Cancer Receiving Letrozole Treatment: The EvaluateTM Study

Science.gov (United States)

Fasching, P. A.; Fehm, T.; Kellner, S.; de Waal, J.; Rezai, M.; Baier, B.; Baake, G.; Kolberg, H.-C.; Guggenberger, M.; Warm, M.; Harbeck, N.; Würstlein, R.; Deuker, J.-U.; Dall, P.; Richter, B.; Wachsmann, G.; Brucker, C.; Siebers, J. W.; Fersis, N.; Kuhn, T.; Wolf, C.; Vollert, H.-W.; Breitbach, G.-P.; Janni, W.; Landthaler, R.; Kohls, A.; Rezek, D.; Noesslet, T.; Fischer, G.; Henschen, S.; Praetz, T.; Heyl, V.; Kühn, T.; Krauß, T.; Thomssen, C.; Kümmel, S.; Hohn, A.; Tesch, H.; Mundhenke, C.; Hein, A.; Rauh, C.; Bayer, C. M.; Jacob, A.; Schmidt, K.; Belleville, E.; Hadji, P.; Wallwiener, D.; Grischke, E.-M.; Beckmann, M. W.; Brucker, S. Y.

2014-01-01

Introduction: The EvaluateTM study (Evaluation of therapy management and patient compliance in postmenopausal hormone receptor-positive breast cancer patients receiving letrozole treatment) is a prospective, non-interventional study for the assessment of therapy management and compliance in the routine care of postmenopausal women with invasive hormone receptor-positive breast cancer receiving letrozole. The parameters for inclusion in the study are presented and discussed here. Material and Methods: Between January 2008 and December 2009 a total of 5045 patients in 310 study centers were recruited to the EvaluateTM study. Inclusion criteria were hormone receptor-positive breast cancer and adjuvant treatment or metastasis. 373 patients were excluded from the analysis for various reasons. Results: A total of 4420 patients receiving adjuvant treatment and 252 patients with metastasis receiving palliative treatment were included in the study. For 4181 patients receiving adjuvant treatment, treatment with the aromatase inhibitor letrozole commenced immediately after surgery (upfront). Two hundred patients had initially received tamoxifen and started aromatase inhibitor treatment with letrozole at 1–5 years after diagnosis (switch), und 39 patients only commenced letrozole treatment 5–10 years after diagnosis (extended endocrine therapy). Patient and tumor characteristics were within expected ranges, as were comorbidities and concurrent medication. Conclusion: The data from the EvaluateTM study will offer a good overview of therapy management in the routine care of postmenopausal women with hormone receptor-positive breast cancer. Planned analyses will look at therapy compliance and patient satisfaction with how information is conveyed and the contents of the conveyed information. PMID:25568468

Effect of long-term treatment with steroid hormones or tamoxifen on the progesterone receptor and androgen receptor in the endometrium of ovariectomized cynomolgus macaques

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Cline J Mark

2003-02-01

Full Text Available Abstract The progesterone receptor (PR and androgen receptor (AR belong to the nuclear receptor superfamily. Two isoforms of PR (A and B have been identified with different functions. The expression of AR, each isoform of PR and their involvement in long-term effects on the endometrium after hormonal replacement therapy (HRT or tamoxifen (TAM treatment is not known. The aims of this study were to determine PR(A+B, PRB and AR distribution by immunohistochemistry in the macaque (Macaca fascicularis endometrium. Ovariectomized (OVX animals were orally treated continuously for 35 months with either conjugated equine estrogens (CEE; medroxyprogesterone acetate (MPA; the combination of CEE/MPA; or TAM. Treatment with CEE/MPA tended to down-regulate PR in the superficial glands, but increased it in the stroma. TAM treatment increased both the PR and PRB levels in the stroma. Overall, less than 20% of the cells were positive for the PRB isoform and less variation was observed after steroid treatment. AR was found in the stroma, mainly distributed in the basal layer of the endometrium in the OVX and steroid treated groups, but was absent in the TAM treated group. No AR was found in the glandular epithelium. The present data show that long-term hormone treatment affects the PR level, and also the ratio between PRA and PRB in the endometrium.

Thyroid hormone signaling in the hypothalamus

NARCIS (Netherlands)

Alkemade, Anneke; Visser, Theo J.; Fliers, Eric

2008-01-01

PURPOSE OF REVIEW: Proper thyroid hormone signaling is essential for brain development and adult brain function. Signaling can be disrupted at many levels due to altered thyroid hormone secretion, conversion or thyroid hormone receptor binding. RECENT FINDINGS: Mutated genes involved in thyroid

Participation of the endoplasmic reticulum protein chaperone thio-oxidoreductase in gonadotropin-releasing hormone receptor expression at the plasma membrane

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W. Lucca-Junior

2009-02-01

Full Text Available Chaperone members of the protein disulfide isomerase family can catalyze the thiol-disulfide exchange reaction with pairs of cysteines. There are 14 protein disulfide isomerase family members, but the ability to catalyze a thiol disulfide exchange reaction has not been demonstrated for all of them. Human endoplasmic reticulum protein chaperone thio-oxidoreductase (ERp18 shows partial oxidative activity as a protein disulfide isomerase. The aim of the present study was to evaluate the participation of ERp18 in gonadotropin-releasing hormone receptor (GnRHR expression at the plasma membrane. Cos-7 cells were cultured, plated, and transfected with 25 ng (unless indicated wild-type human GnRHR (hGnRHR or mutant GnRHR (Cys14Ala and Cys200Ala and pcDNA3.1 without insert (empty vector or ERp18 cDNA (75 ng/well, pre-loaded for 18 h with 1 µCi myo-[2-3H(N]-inositol in 0.25 mL DMEM and treated for 2 h with buserelin. We observed a decrease in maximal inositol phosphate (IP production in response to buserelin in the cells co-transfected with hGnRHR, and a decrease from 20 to 75 ng of ERp18 compared with cells co-transfected with hGnRHR and empty vector. The decrease in maximal IP was proportional to the amount of ERp18 DNA over the range examined. Mutants (Cys14Ala and Cys200Ala that could not form the Cys14-Cys200 bridge essential for plasma membrane routing of the hGnRHR did not modify maximal IP production when they were co-transfected with ERp18. These results suggest that ERp18 has a reduction role on disulfide bonds in wild-type hGnRHR folding.

Diminished hepatic growth hormone receptor binding in sex-linked dwarf broiler and leghorn chickens.

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Leung, F C; Styles, W J; Rosenblum, C I; Lilburn, M S; Marsh, J A

1987-02-01

Hepatic growth hormone (GH) receptor binding was compared in normal and sex-linked dwarfs (SLD) from both Hubbard and Cornell strain chickens. At 6, 8, and 20 weeks of age, hepatic GH receptor binding in the Hubbard SLD chickens was significantly lower than that of normal fast-growing birds. At 20 weeks of age, only 2 of 22 SLD chickens in the Hubbard broiler strain showed positive binding at a high enough level to allow for Scatchard analysis. The affinity constants and binding capacities of these two SLD chickens were numerically (but not significantly) lower than those of the normal fast-growing birds. We further examined hepatic GH receptor binding in two closely related White Leghorn strains of chickens that have been maintained as closed breeding populations for many years. We observed no detectable hepatic GH binding in the Cornell SLD chickens (N = 20), as compared to the normal-growing control strain (K strain). In both SLD strains, pretreatment with 4 M MgCl2 did not enhance GH binding, suggesting that there was no endogenous GH binding to the receptor. Based on these data, we suggest that the lack, or greatly reduced number, of GH receptors may be a major contributing factor to the dwarfism observed in these strains.

Hormone Therapy for Breast Cancer

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... Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer ... sensitive breast cancer cells contain proteins called hormone receptors that become activated when hormones bind to them. ...

From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

Science.gov (United States)

Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

2015-09-01

Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cellular androgen content influences enzalutamide agonism of F877L mutant androgen receptor

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Coleman, Daniel J.; Van Hook, Kathryn; King, Carly J.; Schwartzman, Jacob; Lisac, Robert; Urrutia, Joshua; Sehrawat, Archana; Woodward, Josha; Wang, Nicholas J.; Gulati, Roman; Thomas, George V.; Beer, Tomasz M.; Gleave, Martin; Korkola, James E.; Gao, Lina; Heiser, Laura M.; Alumkal, Joshi J.

2016-01-01

Prostate cancer is the most commonly diagnosed and second-most lethal cancer among men in the United States. The vast majority of prostate cancer deaths are due to castration-resistant prostate cancer (CRPC) – the lethal form of the disease that has progressed despite therapies that interfere with activation of androgen receptor (AR) signaling. One emergent resistance mechanism to medical castration is synthesis of intratumoral androgens that activate the AR. This insight led to the development of the AR antagonist enzalutamide. However, resistance to enzalutamide invariably develops, and disease progression is nearly universal. One mechanism of resistance to enzalutamide is an F877L mutation in the AR ligand-binding domain that can convert enzalutamide to an agonist of AR activity. However, mechanisms that contribute to the agonist switch had not been fully clarified, and there were no therapies to block AR F877L. Using cell line models of castration-resistant prostate cancer (CRPC), we determined that cellular androgen content influences enzalutamide agonism of mutant F877L AR. Further, enzalutamide treatment of AR F877L-expressing cell lines recapitulated the effects of androgen activation of F877L AR or wild-type AR. Because the BET bromodomain inhibitor JQ-1 was previously shown to block androgen activation of wild-type AR, we tested JQ-1 in AR F877L-expressing CRPC models. We determined that JQ-1 suppressed androgen or enzalutamide activation of mutant F877L AR and suppressed growth of mutant F877L AR CRPC tumors in vivo, demonstrating a new strategy to treat tumors harboring this mutation. PMID:27276681

Ovarian hormones modify anxiety behavior and glucocorticoid receptors after chronic social isolation stress.

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Ramos-Ortolaza, Dinah L; Doreste-Mendez, Raura J; Alvarado-Torres, John K; Torres-Reveron, Annelyn

2017-06-15

Chronic social isolation could lead to a disruption in the Hypothalamic-Pituitary-Adrenal (HPA) axis, resulting in anxiety and depressive-like behaviors but cycling estrogens could modify these behaviors. The aim of this study was to determine if changes in ovarian hormones during the normal cycle could interact with social isolation to alter anxiety and depressive-like behaviors. In parallel, we examined the expression of glucocorticoid receptor (GR) and synaptic vesicle protein synaptophysin in the hippocampus and hypothalamus of Sprague Dawley normal cycling female rats. We assigned rats to either isolated or paired housing for 8 weeks. To assess anxiety and depressive-like behaviors, we used the open field test and forced swim test, respectively. Female rats were tested at either diestrus, estrus, or proestrus stage of the estrous cycle. After behaviors, rats were perfused and brains collected. Brain sections containing hippocampus and hypothalamus were analyzed using immunohistochemistry for synaptophysin and glucocorticoid receptor (GR) levels. We found an increase in depressive-like behaviors for isolated animals compared to paired housed rats, regardless of the estrous cycle stage. Interestingly, we found a decrease in anxiety behaviors in females in the estrus stage accompanied by a decrease in GR expression in hippocampal DG and CA3. However, no changes in synaptophysin were observed in any of the areas of studied. Our results support the beneficial effects of circulating ovarian hormones in anxiety, possibly by decreasing GR expression. Copyright © 2017 Elsevier B.V. All rights reserved.

The adiponectin receptor homologs in C. elegans promote energy utilization and homeostasis

DEFF Research Database (Denmark)

Svensson, Emma; Olsen, Louise Cathrine Braun; Mörck, Catarina

2011-01-01

in the nematode C. elegans, named paqr-1, paqr-2 and paqr-3. These are differently expressed in the intestine (the main fat-storing tissue), hypodermis, muscles, neurons and secretory tissues, from which they could exert systemic effects. Analysis of mutants revealed that paqr-1 and -2 are novel metabolic...... regulators in C. elegans and that they act redundantly but independently from paqr-3. paqr-2 is the most important of the three paqr genes: mutants grow poorly, fail to adapt to growth at low temperature, and have a very high fat content with an abnormal enrichment in long (C20) poly-unsaturated fatty acids...... when combined with the paqr-1 mutation. paqr-2 mutants are also synthetic lethal with mutations in nhr-49, sbp-1 and fat-6, which are C. elegans homologs of nuclear hormone receptors, SREBP and FAT-6 (a Δ9 desaturase), respectively. Like paqr-2, paqr-1 is also synthetic lethal with sbp-1. Mutations...

Growth hormone receptor-deficient pigs resemble the pathophysiology of human Laron syndrome and reveal altered activation of signaling cascades in the liver

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Arne Hinrichs

2018-05-01

Full Text Available Objective: Laron syndrome (LS is a rare, autosomal recessive disorder in humans caused by loss-of-function mutations of the growth hormone receptor (GHR gene. To establish a large animal model for LS, pigs with GHR knockout (KO mutations were generated and characterized. Methods: CRISPR/Cas9 technology was applied to mutate exon 3 of the GHR gene in porcine zygotes. Two heterozygous founder sows with a 1-bp or 7-bp insertion in GHR exon 3 were obtained, and their heterozygous F1 offspring were intercrossed to produce GHR-KO, heterozygous GHR mutant, and wild-type pigs. Since the latter two groups were not significantly different in any parameter investigated, they were pooled as the GHR expressing control group. The characterization program included body and organ growth, body composition, endocrine and clinical-chemical parameters, as well as signaling studies in liver tissue. Results: GHR-KO pigs lacked GHR and had markedly reduced serum insulin-like growth factor 1 (IGF1 levels and reduced IGF-binding protein 3 (IGFBP3 activity but increased IGFBP2 levels. Serum GH concentrations were significantly elevated compared with control pigs. GHR-KO pigs had a normal birth weight. Growth retardation became significant at the age of five weeks. At the age of six months, the body weight of GHR-KO pigs was reduced by 60% compared with controls. Most organ weights of GHR-KO pigs were reduced proportionally to body weight. However, the weights of liver, kidneys, and heart were disproportionately reduced, while the relative brain weight was almost doubled. GHR-KO pigs had a markedly increased percentage of total body fat relative to body weight and displayed transient juvenile hypoglycemia along with decreased serum triglyceride and cholesterol levels. Analysis of insulin receptor related signaling in the liver of adult fasted pigs revealed increased phosphorylation of IRS1 and PI3K. In agreement with the loss of GHR, phosphorylation of STAT5 was

The diageotropica mutant of tomato lacks high specific activity auxin sites

International Nuclear Information System (INIS)

Hicks, G.R.; Lomax, T.L.; Rayle, D.L.

1989-01-01

Tomato (Lycopersicum esculentum, Mill) plants homozygous for the single gene diageotropica (dgt) mutation have reduced shoot growth, abnormal vascular tissue, altered leaf morphology, and lack of lateral root branching. These and other morphological and physiological abnormalities suggest that dgt plants are unable to respond to the plant growth hormone auxin (indole-3-acetic acid, IAA). The photoaffinity auxin analogue 3 H-5N 3 -IAA specifically labels a polypeptide doublet of 40 ad 42 kD in membrane preparations from stems of the parental variety VFN8, but not from stems of dgt. In elongation tests, excised dgt roots respond in the same manner to IAA an VFN8 roots. These data suggest that the two polypeptides are part of a physiologically important auxin receptor system which is altered in a tissue-specific manner in the mutant

Mathematical modeling of gonadotropin-releasing hormone signaling.

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Pratap, Amitesh; Garner, Kathryn L; Voliotis, Margaritis; Tsaneva-Atanasova, Krasimira; McArdle, Craig A

2017-07-05

Gonadotropin-releasing hormone (GnRH) acts via G-protein coupled receptors on pituitary gonadotropes to control reproduction. These are G q -coupled receptors that mediate acute effects of GnRH on the exocytotic secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as the chronic regulation of their synthesis. GnRH is secreted in short pulses and GnRH effects on its target cells are dependent upon the dynamics of these pulses. Here we overview GnRH receptors and their signaling network, placing emphasis on pulsatile signaling, and how mechanistic mathematical models and an information theoretic approach have helped further this field. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Characterisation of prostate cancer lesions in heterozygous Men1 mutant mice

International Nuclear Information System (INIS)

Seigne, Christelle; Fontanière, Sandra; Carreira, Christine; Lu, Jieli; Tong, Wei-Ming; Fontanière, Bernard; Wang, Zhao-Qi; Zhang, Chang Xian; Frappart, Lucien

2010-01-01

Mutations of the MEN1 gene predispose to multiple endocrine neoplasia type 1 (MEN1) syndrome. Our group and others have shown that Men1 disruption in mice recapitulates MEN1 pathology. Intriguingly, rare lesions in hormone-dependent tissues, such as prostate and mammary glands, were also observed in the Men1 mutant mice. To study the occurrence of prostate lesions, we followed a male mouse cohort of 47 Men1 +/- mice and 23 age-matched control littermates, starting at 18 months of age, and analysed the prostate glands from the cohort. Six Men1 +/- mice (12.8%) developed prostate cancer, including two adenocarcinomas and four in situ carcinomas, while none of the control mice developed cancerous lesions. The expression of menin encoded by the Men1 gene was found to be drastically reduced in all carcinomas, and partial LOH of the wild-type Men1 allele was detected in three of the five analysed lesions. Using immunostaining for the androgen receptor and p63, a basal epithelial cell marker, we demonstrated that the menin-negative prostate cancer cells did not display p63 expression and that the androgen receptor was expressed but more heterogeneous in these lesions. Furthermore, our data showed that the expression of the cyclin-dependent kinase inhibitor CDKN1B (p27), a Men1 target gene known to be inactivated during prostate cell tumorigenesis, was notably decreased in the prostate cancers that developed in the mutant mice. Our work suggests the possible involvement of Men1 inactivation in the tumorigenesis of the prostate gland

Regulation of 1, 4, 5-triphosphate receptor channel gating dynamics by mutant presenilin in Alzheimer's disease cells

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Wei, Fang; Li, Xiang; Cai, Meichun; Liu, Yanping; Jung, Peter; Shuai, Jianwei

2017-06-01

In neurons of patients with Alzheimer's disease, the intracellular Ca2+ concentration is increased by its release from the endoplasmic reticulum via the inositol 1, 4, 5-triphosphate receptor (IP3R). In this paper, we discuss the IP3R gating dynamics in familial Alzheimer's disease (FAD) cells induced with presenilin mutation PS1. By fitting the parameters of an IP3R channel model to experimental data of the open probability, the mean open time and the mean closed time of IP3R channels, in control cells and FAD mutant cells, we suggest that the interaction of presenilin mutation PS1 with IP3R channels leads the decrease in the unbinding rates of IP3 and the activating Ca2+ from IP3Rs. As a result, the increased affinities of IP3 and activating Ca2+ for IP3R channels induce the increase in the Ca2+ signal in FAD mutant cells. Specifically, the PS1 mutation decreases the IP3 dissociation rate of IP3R channels significantly in FAD mutant cells. Our results suggest possible novel targets for FAD therapeutic intervention.

Association of Exon 10A and 10B inactivating mutation of follicle stimulating hormone receptor gene (FSHR) and Polycystic Ovarian Syndrome in Vellore cohort

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Sekar, Nishu; Kulkarni, Rucha; Ozalkar, Sharvari; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

2017-11-01

Polycystic ovarian syndrome is the most common heterogenous endocrine disorder in women. Follicle stimulating hormone receptor is associated with normal development as well as maturation of follicles and triggers estrogen production in granulosa cells of the ovary. Inactivating mutation in FSHR gene correlated with reduction of ovarian function in women is due to damage to receptor function. This study aims to investigate whether inactivating mutations, in follicle stimulating hormone receptor gene is related to polycystic ovarian morphology in women with PCOS. Genomic DNA isolated from 15 subjects from Sandhya Hospital, Vellore (10 patients with PCOS and 5 healthy controls) was taken for this study. Patient data included a clinical report, hormonal levels, and ovarian morphological details. DNA isolation was followed by DNA amplification by polymerase chain reaction using Exon 10 A and Exon 10 B primers. The PCR-RFLP analysis was performed using Dde1 restriction enzyme. Here we discuss inactivating mutation found in Exon 10 of FSHR gene in patients with PCOS.The absence of inactivating mutation was observed through PCR-RFLP study on Exon 10A and Exon 10B.

A Bacterial Receptor PcrK Senses the Plant Hormone Cytokinin to Promote Adaptation to Oxidative Stress

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Fang-Fang Wang

2017-12-01

Full Text Available Summary: Recognition of the host plant is a prerequisite for infection by pathogenic bacteria. However, how bacterial cells sense plant-derived stimuli, especially chemicals that function in regulating plant development, remains completely unknown. Here, we have identified a membrane-bound histidine kinase of the phytopathogenic bacterium Xanthomonas campestris, PcrK, as a bacterial receptor that specifically detects the plant cytokinin 2-isopentenyladenine (2iP. 2iP binds to the extracytoplasmic region of PcrK to decrease its autokinase activity. Through a four-step phosphorelay, 2iP stimulation decreased the phosphorylation level of PcrR, the cognate response regulator of PcrK, to activate the phosphodiesterase activity of PcrR in degrading the second messenger 3′,5′-cyclic diguanylic acid. 2iP perception by the PcrK-PcrR remarkably improves bacterial tolerance to oxidative stress by regulating the transcription of 56 genes, including the virulence-associated TonB-dependent receptor gene ctrA. Our results reveal an evolutionarily conserved, inter-kingdom signaling by which phytopathogenic bacteria intercept a plant hormone signal to promote adaptation to oxidative stress. : How pathogenic bacteria use receptors to recognize the signals of the host plant is unknown. Wang et al. have identified a bacterial receptor histidine kinase that specifically senses the plant hormone cytokinin. Through a four-step phosphorelay, cytokinin perception triggers degradation of a second messenger, c-di-GMP, to activate the bacterial response to oxidative stress. Keywords: histidine kinase, ligand, cytokinin, autokinase activity, phosphorelay, response regulator, two-component signal transduction system, Xanthomonas campestris pv. campestris, virulence, oxidative stress

Nuclear translocation and retention of growth hormone

DEFF Research Database (Denmark)

Mertani, Hichem C; Raccurt, Mireille; Abbate, Aude

2003-01-01

We have previously demonstrated that GH is subject to rapid receptor-dependent nuclear translocation. Here, we examine the importance of ligand activation of the GH-receptor (GHR)-associated Janus kinase (JAK) 2 and receptor dimerization for hormone internalization and nuclear translocation by use...... of cells stably transfected with cDNA for the GHR. Staurosporine and herbimycin A treatment of cells did not affect the ability of GH to internalize but resulted in increased nuclear accumulation of hormone. Similarly, receptor mutations, which prevent the association and activation of JAK2, did not affect...... the ability of the hormone to internalize or translocate to the nucleus but resulted in increased nuclear accumulation of GH. These results were observed both by nuclear isolation and confocal laser scanning microscopy. Staurosporine treatment of cells in which human GH (hGH) was targeted to the cytoplasm...

Differentially expressed genes in the head of the 2nd instar pre-molting larvae of the nm2 mutant of the silkworm, Bombyx mori.

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Pingyang Wang

Full Text Available Molting is an important physiological process in the larval stage of Bombyx mori and is controlled by various hormones and peptides. The silkworm mutant that exhibits the phenotype of non-molting in the 2nd instar (nm2 is incapable of molting in the 2nd instar and dies after seven or more days. The ecdysone titer in the nm2 mutant is lower than that in the wildtype, and the mutant can be rescued by feeding with 20E and cholesterol. The results of positional cloning indicated that structural alteration of BmCPG10 is responsible for the phenotype of the nm2 mutant. To explore the possible relationship between BmCPG10 and the ecdysone titer as well as the genes affected by BmCPG10, digital gene expression (DGE profile analysis was conducted in the nm2 mutant, with the wildtype strain C603 serving as the control. The results revealed 1727 differentially expressed genes, among which 651 genes were upregulated and 1076 were downregulated in nm2. BLASTGO analysis showed that these differentially expressed genes were involved in various biological processes, cellular components and molecular functions. KEGG analysis indicated an enrichment of these differentially expressed genes in 240 pathways, including metabolic pathways, pancreatic secretion, protein digestion and absorption, fat digestion and absorption and glycerolipid metabolism. To verify the accuracy of the DGE results, quantitative reverse transcription PCR (qRT-PCR was performed, focusing on key genes in several related pathways, and the results were highly consistent with the DGE results. Our findings indicated significant differences in cuticular protein genes, ecdysone biosynthesis genes and ecdysone-related nuclear receptors genes, but no significant difference in juvenile hormone and chitin biosynthesis genes was detected. Our research findings lay the foundation for further research on the formation mechanism of the nm2 mutant.

Luteinizing hormone receptors in human ovarian follicles and corpora lutea during the menstrual cycle

International Nuclear Information System (INIS)

Yamoto, M.; Nakano, R.; Iwasaki, M.; Ikoma, H.; Furukawa, K.

1986-01-01

The binding of 125 I-labeled human luteinizing hormone (hLH) to the 2000-g fraction of human ovarian follicles and corpora lutea during the entire menstrual cycle was examined. Specific high affinity, low capacity receptors for hLH were demonstrated in the 2000-g fraction of both follicles and corpora lutea. Specific binding of 125 I-labeled hLH to follicular tissue increased from the early follicular phase to the ovulatory phase. Specific binding of 125 I-labeled hLH to luteal tissue increased from the early luteal phase to the midluteal phase and decreased towards the late luteal phase. The results of the present study indicate that the increase and decrease in receptors for hLH during the menstrual cycle might play an important role in the regulation of the ovarian cycle

Crosstalk between thyroid hormone receptor and liver X receptor in the regulation of selective Alzheimer's disease indicator-1 gene expression.

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Emi Ishida

Full Text Available Selective Alzheimer's disease (AD indicator 1 (Seladin-1 has been identified as a gene down-regulated in the degenerated lesions of AD brain. Up-regulation of Seladin-1 reduces the accumulation of β-amyloid and neuronal death. Thyroid hormone (TH exerts an important effect on the development and maintenance of central nervous systems. In the current study, we demonstrated that Seladin-1 gene and protein expression in the forebrain was increased in thyrotoxic mice compared with that of euthyroid mice. However, unexpectedly, no significant decrease in the gene and protein expression was observed in hypothyroid mice. Interestingly, an agonist of liver X receptor (LXR, TO901317 (TO administration in vivo increased Seladin-1 gene and protein expression in the mouse forebrain only in a hypothyroid state and in the presence of mutant TR-β, suggesting that LXR-α would compensate for TR-β function to maintain Seladin-1 gene expression in hypothyroidism and resistance to TH. TH activated the mouse Seladin-1 gene promoter (-1936/+21 bp and site 2 including canonical TH response element (TRE half-site in the region between -159 and -154 bp is responsible for the positive regulation. RXR-α/TR-β heterodimerization was identified on site 2 by gel-shift assay, and chromatin immunoprecipitation assay revealed the recruitment of TR-β to site 2 and the recruitment was increased upon TH administration. On the other hand, LXR-α utilizes a distinct region from site 2 (-120 to -102 bp to activate the mouse Seladin-1 gene promoter. Taking these findings together, we concluded that TH up-regulates Seladin-1 gene expression at the transcriptional level and LXR-α maintains the gene expression.

Intracellular postsynaptic cannabinoid receptors link thyrotropin-releasing hormone receptors to TRPC-like channels in thalamic paraventricular nucleus neurons.

Science.gov (United States)

Zhang, L; Kolaj, M; Renaud, L P

2015-12-17

In rat thalamic paraventricular nucleus of thalamus (PVT) neurons, activation of thyrotropin-releasing hormone (TRH) receptors enhances excitability via concurrent decrease in G protein-coupled inwardly-rectifying potassium (GIRK)-like and activation of transient receptor potential cation (TRPC)4/5-like cationic conductances. An exploration of intracellular signaling pathways revealed the TRH-induced current to be insensitive to phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitors, but reduced by D609, an inhibitor of phosphatidylcholine-specific PLC (PC-PLC). A corresponding change in the I-V relationship implied suppression of the cationic component of the TRH-induced current. Diacylglycerol (DAG) is a product of the hydrolysis of PC. Studies focused on the isolated cationic component of the TRH-induced response revealed a reduction by RHC80267, an inhibitor of DAG lipase, the enzyme involved in the hydrolysis of DAG to the endocannabinoid 2-arachidonoylglycerol (2-AG). Further investigation revealed enhancement of the cationic component in the presence of either JZL184 or WWL70, inhibitors of enzymes involved in the hydrolysis of 2-AG. A decrease in the TRH-induced response was noted in the presence of rimonabant or SR144528, membrane permeable CB1 and CB2 receptor antagonists, respectively. A decrease in the TRH-induced current by intracellular, but not by bath application of the membrane impermeable peptide hemopressin, selective for CB1 receptors, suggests a postsynaptic intracellular localization of these receptors. The TRH-induced current was increased in the presence of arachidonyl-2'-chloroethylamide (ACEA) or JWH133, CB1 and CB2 receptor agonists, respectively. The PI3-kinase inhibitor LY294002, known to inhibit TRPC translocation, decreased the response to TRH. In addition, a TRH-induced enhancement of the low-threshold spike was prevented by both rimonabant, and SR144528. TRH had no influence on excitatory or inhibitory miniature

Involvement of Human Estrogen Related Receptor Alpha 1 (hERR Alpha 1) in Breast Cancer and Hormonally Insensitive Disease

Science.gov (United States)

2001-08-01

Identification of a new class of steroid hormone receptors. Nature, 331: 91-94, 1988. 4. Vanacker , J. M ., Pettersson, K., Gustafsson, J. A., and...Lippman, M . E., Thompson, E. B., Simon, R., Barlock, A., Green, L., Huff, K. K., Do, H. M ., Aitken, S. C., and Warren, R. Estrogen receptor status: an...important variable in predicting response to endocrine therapy in metastatic breast cancer. Eur J Cancer, 16: 323-331, 1980. 2. Clark, G. M . and

TBLR1 regulates the expression of nuclear hormone receptor co-repressors

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Brown Stuart

2006-08-01

Full Text Available Abstract Background Transcription is regulated by a complex interaction of activators and repressors. The effectors of repression are large multimeric complexes which contain both the repressor proteins that bind to transcription factors and a number of co-repressors that actually mediate transcriptional silencing either by inhibiting the basal transcription machinery or by recruiting chromatin-modifying enzymes. Results TBLR1 [GenBank: NM024665] is a co-repressor of nuclear hormone transcription factors. A single highly conserved gene encodes a small family of protein molecules. Different isoforms are produced by differential exon utilization. Although the ORF of the predominant form contains only 1545 bp, the human gene occupies ~200 kb of genomic DNA on chromosome 3q and contains 16 exons. The genomic sequence overlaps with the putative DC42 [GenBank: NM030921] locus. The murine homologue is structurally similar and is also located on Chromosome 3. TBLR1 is closely related (79% homology at the mRNA level to TBL1X and TBL1Y, which are located on Chromosomes X and Y. The expression of TBLR1 overlaps but is distinct from that of TBL1. An alternatively spliced form of TBLR1 has been demonstrated in human material and it too has an unique pattern of expression. TBLR1 and the homologous genes interact with proteins that regulate the nuclear hormone receptor family of transcription factors. In resting cells TBLR1 is primarily cytoplasmic but after perturbation the protein translocates to the nucleus. TBLR1 co-precipitates with SMRT, a co-repressor of nuclear hormone receptors, and co-precipitates in complexes immunoprecipitated by antiserum to HDAC3. Cells engineered to over express either TBLR1 or N- and C-terminal deletion variants, have elevated levels of endogenous N-CoR. Co-transfection of TBLR1 and SMRT results in increased expression of SMRT. This co-repressor undergoes ubiquitin-mediated degradation and we suggest that the stabilization of

Immunodetection of Thyroid Hormone Receptor (Alpha1/Alpha2) in the Rat Uterus and Oviduct

International Nuclear Information System (INIS)

Öner, Jale; Öner, Hakan

2007-01-01

The aim of this study was to investigate the immunolocalization and the existence of thyroid hormone receptors (THR) (alpha1/alpha2) in rat uterus and oviduct. For this purpose 6 female Wistar albino rats found in estrous period were used. Tissue samples fixed in 10% neutral formalin were examined immunohistochemically. Sections were incubated with primary mouse-monoclonal THR (alpha1/alpha2) antibody. In uterus, THR (alpha1/alpha2) immunoreacted strongly with uterine luminal epithelium, endometrial gland epithelium and endometrial stromal cells and, moderately with myometrial smooth muscle. In oviduct, they were observed moderately in the epithelium of the tube and the smooth muscle cells of the muscular layer. In conclusion, the presence of THR in uterus and oviduct suggests that these organs are an active site of thyroid hormones

Transcriptome changes associated wtih delayed flower senescence on transgenic petunia by inducing expression of etr1-1, a mutant ethylene receptor

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Flowers of ethylene-sensitive ornamental plants transformed with ethylene-insensitive 1-1(etr 1-1), a mutant ethylene receptor first isolated from Arabidopsis, are known to have longer shelf lives. We have generated petunia plants in which the etr 1-1 gene was over-expressed under the control of a c...

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

OpenAIRE

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2010-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

Role of adipokinetic hormone and adenosine in the anti-stress response in Drosophila melanogaster.

Science.gov (United States)

Zemanová, Milada; Stašková, Tereza; Kodrík, Dalibor

2016-01-01

The role of adipokinetic hormone (AKH) and adenosine in the anti-stress response was studied in Drosophila melanogaster larvae and adults carrying a mutation in the Akh gene (Akh(1)), the adenosine receptor gene (AdoR(1)), or in both of these genes (Akh(1) AdoR(1) double mutant). Stress was induced by starvation or by the addition of an oxidative stressor paraquat (PQ) to food. Mortality tests revealed that the Akh(1) mutant was the most resistant to starvation, while the AdoR(1) mutant was the most sensitive. Conversely, the Akh(1) AdoR(1) double mutant was more sensitive to PQ toxicity than either of the single mutants. Administration of PQ significantly increased the Drome-AKH level in w(1118) and AdoR(1) larvae; however, this was not accompanied by a simultaneous increase in Akh gene expression. In contrast, PQ significantly increased the expression of the glutathione S-transferase D1 (GstD1) gene. The presence of both a functional adenosine receptor and AKH seem to be important for the proper control of GstD1 gene expression under oxidative stress, however, the latter appears to play more dominant role. On the other hand, differences in glutathione S-transferase (GST) activity among the strains, and between untreated and PQ-treated groups were minimal. In addition, the glutathione level was significantly lower in all untreated AKH- or AdoR-deficient mutant flies as compared with the untreated control w(1118) flies and further declined following treatment with PQ. All oxidative stress characteristics modified by mutations in Akh gene were restored or even improved by 'rescue' mutation in flies which ectopically express Akh. Thus, the results of the present study demonstrate the important roles of AKH and adenosine in the anti-stress response elicited by PQ in a D. melanogaster model, and provide the first evidence for the involvement of adenosine in the anti-oxidative stress response in insects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Brain receptors for thyrotropin releasing hormone in morphine tolerant-dependent rats

Energy Technology Data Exchange (ETDEWEB)

Bhargava, H.N.; Das, S.

1986-03-01

The effect of chronic treatment of rats with morphine and its subsequent withdrawal on the brain receptors for thyrotropin releasing hormone (TRH) labeled with /sup 3/H-(3MeHis/sup 2/)TRH (MeTRH). Male Sprague Dawley rats were implanted with 4 morphine pellets (each containing 75 mg morphine base) during a 3-day period. Placebo pellet implanted rats served as controls. Both tolerance to and dependence on morphine developed as a result of this procedure. For characterization of brain TRH receptors, the animals were sacrificed 72 h after the implantation of first pellet. In another set of animals the pellets were removed and were sacrificed 24 h later. The binding of /sup 3/H-MeTRH to membranes prepared from brain without the cerebellum was determined. /sup 3/H-MeTRH bound to brain membranes prepared from placebo pellet implanted rats at a single high affinity site with a B/sub max/ value of 33.50 +/- 0.97 fmol/mg protein and a K/sub d/ of 5.18 +/- 0.21 nM. Implantation of morphine pellets did not alter the B/sub max/ value of /sup 3/H-MeTRH but decreased the K/sub d/ value significantly. Abrupt or naloxone precipitated withdrawal of morphine did not alter B/sub max/ or the K/sub d/ values. The binding of /sup 3/H-MeTRH to brain areas was also determined. The results suggest that the development of tolerance to morphine is associated with enhanced sensitivity of brain TRH receptors, however abrupt withdrawal of morphine does not change the characteristics of brain TRH receptors.

[Common physicochemical characteristics of endogenous hormones-- liberins and statins].

Science.gov (United States)

Zamiatnin, A A; Voronina, O L

1998-01-01

The common chemical features of oligopeptide releasing-hormones and release inhibiting hormones were investigated with the aid of computer methods. 339 regulatory molecules of such type have been extracted out of data from computer bank EROP-Moscow. They contain from 2 to 47 amino acid residues and their sequences include short sites, which play apparently a decisive role in realization of interactions with the receptors. The analysis of chemical radicals shows that all liberins and statins contain positively charged group and cyclic radical of some amino acids or hydrophobic group. Results of this study indicate that the most chemical radicals of hormones are open for the interaction with potential receptors of target-cells. The mechanism of hormone ligand and receptors binding and conceivable role of amino acid and neurotransmitter radicals in hormonal properties of liberins and statins is discussed.

Central dopamine D2 receptors regulate growth-hormone-dependent body growth and pheromone signaling to conspecific males.

Science.gov (United States)

Noaín, Daniela; Pérez-Millán, M Inés; Bello, Estefanía P; Luque, Guillermina M; Casas Cordero, Rodrigo; Gelman, Diego M; Peper, Marcela; Tornadu, Isabel García; Low, Malcolm J; Becú-Villalobos, Damasia; Rubinstein, Marcelo

2013-03-27

Competition between adult males for limited resources such as food and receptive females is shaped by the male pattern of pituitary growth hormone (GH) secretion that determines body size and the production of urinary pheromones involved in male-to-male aggression. In the brain, dopamine (DA) provides incentive salience to stimuli that predict the availability of food and sexual partners. Although the importance of the GH axis and central DA neurotransmission in social dominance and fitness is clearly appreciated, the two systems have always been studied unconnectedly. Here we conducted a cell-specific genetic dissection study in conditional mutant mice that selectively lack DA D2 receptors (D2R) from pituitary lactotropes (lacDrd2KO) or neurons (neuroDrd2KO). Whereas lacDrd2KO mice developed a normal GH axis, neuroDrd2KO mice displayed fewer somatotropes; reduced hypothalamic Ghrh expression, pituitary GH content, and serum IGF-I levels; and exhibited reduced body size and weight. As a consequence of a GH axis deficit, neuroDrd2KO adult males excreted low levels of major urinary proteins and their urine failed to promote aggression and territorial behavior in control male challengers, in contrast to the urine taken from control adult males. These findings reveal that central D2Rs mediate a neuroendocrine-exocrine cascade that controls the maturation of the GH axis and downstream signals that are critical for fitness, social dominance, and competition between adult males.

CHARACTERIZATION OF THE RECEPTOR FOR GONADOTROPIN-RELEASING HORMONE IN THE PITUITARY OF THE AFRICAN CATFISH, CLARIAS-GARIEPINUS

NARCIS (Netherlands)

de Leeuw, R.; Conn, P. M.; van't Veer, C.; Goos, H. J.; van Oordt, P. G.

1988-01-01

Receptors for gonadotropin-releasing hormone (GnRH) were characterized using a radioligand prepared from a superactive analog of salmon GnRH (sGnRH), D-Arg(6)-Pro(9)-sGnRH-NEt (sGnRHa). Binding of(125)I-sGnRHa to catfish pituitary membrane fractions reached equilibrium after 2 h incubation at 4°C.

rigor mortis encodes a novel nuclear receptor interacting protein required for ecdysone signaling during Drosophila larval development.

Science.gov (United States)

Gates, Julie; Lam, Geanette; Ortiz, José A; Losson, Régine; Thummel, Carl S

2004-01-01

Pulses of the steroid hormone ecdysone trigger the major developmental transitions in Drosophila, including molting and puparium formation. The ecdysone signal is transduced by the EcR/USP nuclear receptor heterodimer that binds to specific response elements in the genome and directly regulates target gene transcription. We describe a novel nuclear receptor interacting protein encoded by rigor mortis (rig) that is required for ecdysone responses during larval development. rig mutants display defects in molting, delayed larval development, larval lethality, duplicated mouth parts, and defects in puparium formation--phenotypes that resemble those seen in EcR, usp, E75A and betaFTZ-F1 mutants. Although the expression of these nuclear receptor genes is essentially normal in rig mutant larvae, the ecdysone-triggered switch in E74 isoform expression is defective. rig encodes a protein with multiple WD-40 repeats and an LXXLL motif, sequences that act as specific protein-protein interaction domains. Consistent with the presence of these elements and the lethal phenotypes of rig mutants, Rig protein interacts with several Drosophila nuclear receptors in GST pull-down experiments, including EcR, USP, DHR3, SVP and betaFTZ-F1. The ligand binding domain of betaFTZ-F1 is sufficient for this interaction, which can occur in an AF-2-independent manner. Antibody stains reveal that Rig protein is present in the brain and imaginal discs of second and third instar larvae, where it is restricted to the cytoplasm. In larval salivary gland and midgut cells, however, Rig shuttles between the cytoplasm and nucleus in a spatially and temporally regulated manner, at times that correlate with the major lethal phase of rig mutants and major switches in ecdysone-regulated gene expression. Taken together, these data indicate that rig exerts essential functions during larval development through gene-specific effects on ecdysone-regulated transcription, most likely as a cofactor for one or more

The chicken c-erbA alpha-product induces expression of thyroid hormone-responsive genes in 3,5,3'-triiodothyronine receptor-deficient rat hepatoma cells

DEFF Research Database (Denmark)

Muñoz, A; Höppner, W; Sap, J

1990-01-01

To determine the capacity of the chicken c-erbA (cTR-alpha) gene product in regulating expression of known thyroid hormone-responsive genes, both the cTR-alpha and the viral v-erbA genes were expressed in FAO cells, a rat hepatoma cell line defective for functional thyroid hormone receptors. Upon...

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

International Nuclear Information System (INIS)

Deusing, Dorothé Jenni; Beyrer, Melanie; Fitzenberger, Elena; Wenzel, Uwe

2015-01-01

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation

Carnitine protects the nematode Caenorhabditis elegans from glucose-induced reduction of survival depending on the nuclear hormone receptor DAF-12

Energy Technology Data Exchange (ETDEWEB)

Deusing, Dorothé Jenni, E-mail: Dorothe.J.Deusing@ernaehrung.uni-giessen.de; Beyrer, Melanie, E-mail: m.beyrer@web.de; Fitzenberger, Elena, E-mail: Elena.Fitzenberger@ernaehrung.uni-giessen.de; Wenzel, Uwe, E-mail: uwe.wenzel@ernaehrung.uni-giessen.de

2015-05-08

Besides its function in transport of fatty acids into mitochondria in order to provide substrates for β-oxidation, carnitine has been shown to affect also glucose metabolism and to inhibit several mechanisms associated with diabetic complications. In the present study we used the mev-1 mutant of the nematode Caenorhabditis elegans fed on a high glucose concentration in liquid media as a diabetes model and tested the effects of carnitine supplementation on their survival under heat-stress. Carnitine at 100 μM completely prevented the survival reduction that was caused by the application of 10 mM glucose. RNA-interference for sir-2.1, a candidate genes mediating the effects of carnitine revealed no contribution of the sirtuin for the rescue of survival. Under daf-12 RNAi rescue of survival by carnitine was abolished. RNA-interference for γ-butyrobetaine hydroxylase 2, encoding the key enzyme for carnitine biosynthesis did neither increase glucose toxicity nor prevent the rescue of survival by carnitine, suggesting that the effects of carnitine supplementation on carnitine levels were significant. Finally, it was demonstrated that neither the amount of lysosomes nor the proteasomal activity were increased by carnitine, excluding that protein degradation pathways, such as autophagy or proteasomal degradation, are involved in the protective carnitine effects. In conclusion, carnitine supplementation prevents the reduction of survival caused by glucose in C. elegans in dependence on a nuclear hormone receptor which displays high homologies to the vertebrate peroxisomal proliferator activated receptors. - Highlights: • Carnitine protects from glucose-induced reduction of stress-resistance. • Carnitine acts via the PPAR homolog DAF-12 on glucose toxicity. • Carnitine protects from glucose toxicity independent of protein degradation.

Stress induces pain transition by potentiation of AMPA receptor phosphorylation.

Science.gov (United States)

Li, Changsheng; Yang, Ya; Liu, Sufang; Fang, Huaqiang; Zhang, Yong; Furmanski, Orion; Skinner, John; Xing, Ying; Johns, Roger A; Huganir, Richard L; Tao, Feng

2014-10-08

Chronic postsurgical pain is a serious issue in clinical practice. After surgery, patients experience ongoing pain or become sensitive to incident, normally nonpainful stimulation. The intensity and duration of postsurgical pain vary. However, it is unclear how the transition from acute to chronic pain occurs. Here we showed that social defeat stress enhanced plantar incision-induced AMPA receptor GluA1 phosphorylation at the Ser831 site in the spinal cord and greatly prolonged plantar incision-induced pain. Interestingly, targeted mutation of the GluA1 phosphorylation site Ser831 significantly inhibited stress-induced prolongation of incisional pain. In addition, stress hormones enhanced GluA1 phosphorylation and AMPA receptor-mediated electrical activity in the spinal cord. Subthreshold stimulation induced spinal long-term potentiation in GluA1 phosphomimetic mutant mice, but not in wild-type mice. Therefore, spinal AMPA receptor phosphorylation contributes to the mechanisms underlying stress-induced pain transition. Copyright © 2014 the authors 0270-6474/14/3413737-10$15.00/0.

Colocalization of corticotropin-releasing hormone and oestrogen receptor-alpha in the paraventricular nucleus of the hypothalamus in mood disorders

NARCIS (Netherlands)

Bao, Ai-Min; Hestiantoro, Andon; van Someren, Eus J. W.; Swaab, Dick F.; Zhou, Jiang-Ning

2005-01-01

Oestrogens may modulate the activity of the hypothalamic-pituitary-adrenal (HPA) axis. The present study was to investigate whether the activity of the HPA axis in mood disorders might be directly modulated by oestrogens via oestrogen receptors (ORs) in the corticotropin-releasing hormone (CRH)

Thyroid hormones regulate selenoprotein expression and selenium status in mice.

Directory of Open Access Journals (Sweden)

Jens Mittag

Full Text Available Impaired expression of selenium-containing proteins leads to perturbed thyroid hormone (TH levels, indicating the central importance of selenium for TH homeostasis. Moreover, critically ill patients with declining serum selenium develop a syndrome of low circulating TH and a central downregulation of the hypothalamus-pituitary-thyroid axis. This prompted us to test the reciprocal effect, i.e., if TH status would also regulate selenoprotein expression and selenium levels. To investigate the TH dependency of selenium metabolism, we analyzed mice expressing a mutant TH receptor α1 (TRα1+m that confers a receptor-mediated hypothyroidism. Serum selenium was reduced in these animals, which was a direct consequence of the mutant TRα1 and not related to their metabolic alterations. Accordingly, hyperthyroidism, genetically caused by the inactivation of TRβ or by oral TH treatment of adult mice, increased serum selenium levels in TRα1+m and controls, thus demonstrating a novel and specific role for TRα1 in selenium metabolism. Furthermore, TH affected the mRNA levels for several enzymes involved in selenoprotein biosynthesis as well as serum selenoprotein P concentrations and the expression of other antioxidative selenoproteins. Taken together, our results show that TH positively affects the serum selenium status and regulates the expression of several selenoproteins. This demonstrates that selenium and TH metabolism are interconnected through a feed-forward regulation, which can in part explain the rapid parallel downregulation of both systems in critical illness.

Methylation of the thyroid stimulating hormone receptor: diagnostic marker of malignity in thyroid cancer

International Nuclear Information System (INIS)

Marrero Rodriguez, Maria Teresa

2007-01-01

The methylation state of the gene promoter for the receptor of the thyroid stimulating hormone (TSH) in the diagnosis of thyroid tumors of epithelial origin was analyzed. The study was conducted in thyroid tissue obtained from paraffin blocks of different thyroid pathologies (papillary, follicular and undifferentiated carcinoma and follicular adenomas). The work was done by using the DNA modification technique with sodium bisulfite, and polymerase chain reaction was applied to analyze the gene methylation state. Methylation of the promoter for the gene of the TSH receptor was found in the papillary carcinomas (33 of 40; 82.5 %), in 10 undifferentiated carcinomas (100 %), and in 10 of the 15 follicular carcinomas analyzed (66.6 %). No methylation was observed in the 8 follicular adenomas under study. The methylation of the gene for the TSH receptor was proposed as a new diagnostic marker of malignity and as a basis for using demethylating agents together with radioiodine therapy in patients with thyroid cancer of epithelial origin that do not respond to therapy. (Author)

The Endocannabinoid System and Sex Steroid Hormone-Dependent Cancers

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Thangesweran Ayakannu

2013-01-01

Full Text Available The “endocannabinoid system (ECS” comprises the endocannabinoids, the enzymes that regulate their synthesis and degradation, the prototypical cannabinoid receptors (CB1 and CB2, some noncannabinoid receptors, and an, as yet, uncharacterised transport system. Recent evidence suggests that both cannabinoid receptors are present in sex steroid hormone-dependent cancer tissues and potentially play an important role in those malignancies. Sex steroid hormones regulate the endocannabinoid system and the endocannabinoids prevent tumour development through putative protective mechanisms that prevent cell growth and migration, suggesting an important role for endocannabinoids in the regulation of sex hormone-dependent tumours and metastasis. Here, the role of the endocannabinoid system in sex steroid hormone-dependent cancers is described and the potential for novel therapies assessed.

Thyroid hormone increases fibroblast growth factor receptor expression and disrupts cell mechanics in the developing organ of corti

Science.gov (United States)

2013-01-01

Background Thyroid hormones regulate growth and development. However, the molecular mechanisms by which thyroid hormone regulates cell structural development are not fully understood. The mammalian cochlea is an intriguing system to examine these mechanisms, as cellular structure plays a key role in tissue development, and thyroid hormone is required for the maturation of the cochlea in the first postnatal week. Results In hypothyroid conditions, we found disruptions in sensory outer hair cell morphology and fewer microtubules in non-sensory supporting pillar cells. To test the functional consequences of these cytoskeletal defects on cell mechanics, we combined atomic force microscopy with live cell imaging. Hypothyroidism stiffened outer hair cells and supporting pillar cells, but pillar cells ultimately showed reduced cell stiffness, in part from a lack of microtubules. Analyses of changes in transcription and protein phosphorylation suggest that hypothyroidism prolonged expression of fibroblast growth factor receptors, and decreased phosphorylated Cofilin. Conclusions These findings demonstrate that thyroid hormones may be involved in coordinating the processes that regulate cytoskeletal dynamics and suggest that manipulating thyroid hormone sensitivity might provide insight into the relationship between cytoskeletal formation and developing cell mechanical properties. PMID:23394545

Genetic evidence that thyroid hormone is indispensable for prepubertal insulin-like growth factor-I expression and bone acquisition in mice.

Science.gov (United States)

Xing, Weirong; Govoni, Kristen E; Donahue, Leah Rae; Kesavan, Chandrasekhar; Wergedal, Jon; Long, Carlin; Bassett, J H Duncan; Gogakos, Apostolos; Wojcicka, Anna; Williams, Graham R; Mohan, Subburaman

2012-05-01

Understanding how bone growth is regulated by hormonal and mechanical factors during early growth periods is important for optimizing the attainment of peak bone mass to prevent or postpone the occurrence of fragility fractures later in life. Using genetic mouse models that are deficient in thyroid hormone (TH) (Tshr(-/-) and Duox2(-/-)), growth hormone (GH) (Ghrhr(lit/lit)), or both (Tshr(-/-); Ghrhr(lit/lit)), we demonstrate that there is an important period prior to puberty when the effects of GH are surprisingly small and TH plays a critical role in the regulation of skeletal growth. Daily administration of T3/T4 during days 5 to 14, the time when serum levels of T3 increase rapidly in mice, rescued the skeletal deficit in TH-deficient mice but not in mice lacking both TH and GH. However, treatment of double-mutant mice with both GH and T3/T4 rescued the bone density deficit. Increased body fat in the TH-deficient as well as TH/GH double-mutant mice was rescued by T3/T4 treatment during days 5 to 14. In vitro studies in osteoblasts revealed that T3 in the presence of TH receptor (TR) α1 bound to a TH response element in intron 1 of the IGF-I gene to stimulate transcription. In vivo studies using TRα and TRβ knockout mice revealed evidence for differential regulation of insulin-like growth factor (IGF)-I expression by the two receptors. Furthermore, blockade of IGF-I action partially inhibited the biological effects of TH, thus suggesting that both IGF-I-dependent and IGF-I-independent mechanisms contribute to TH effects on prepubertal bone acquisition. Copyright © 2012 American Society for Bone and Mineral Research.

Growth hormone preferentially induces the rapid, transient expression of SOCS-3, a novel inhibitor of cytokine receptor signaling

DEFF Research Database (Denmark)

Adams, T E; Hansen, J A; Starr, R

1998-01-01

Four members (SOCS-1, SOCS-2, SOCS-3, and CIS) of a family of cytokine-inducible, negative regulators of cytokine receptor signaling have recently been identified. To address whether any of these genes are induced in response to growth hormone (GH), serum-starved 3T3-F442A fibroblasts were incuba...

Luteinizing hormone receptors in human ovarian follicles and corpora lutea during the menstrual cycle

Energy Technology Data Exchange (ETDEWEB)

Yamoto, M.; Nakano, R.; Iwasaki, M.; Ikoma, H.; Furukawa, K.

1986-08-01

The binding of /sup 125/I-labeled human luteinizing hormone (hLH) to the 2000-g fraction of human ovarian follicles and corpora lutea during the entire menstrual cycle was examined. Specific high affinity, low capacity receptors for hLH were demonstrated in the 2000-g fraction of both follicles and corpora lutea. Specific binding of /sup 125/I-labeled hLH to follicular tissue increased from the early follicular phase to the ovulatory phase. Specific binding of /sup 125/I-labeled hLH to luteal tissue increased from the early luteal phase to the midluteal phase and decreased towards the late luteal phase. The results of the present study indicate that the increase and decrease in receptors for hLH during the menstrual cycle might play an important role in the regulation of the ovarian cycle.

Cerebellar Expression of the Neurotrophin Receptor p75 in Naked-Ataxia Mutant Mouse

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Maryam Rahimi Balaei

2016-01-01

Full Text Available Spontaneous mutation in the lysosomal acid phosphatase 2 (Acp2 mouse (nax—naked-ataxia mutant mouse correlates with severe cerebellar defects including ataxia, reduced size and abnormal lobulation as well as Purkinje cell (Pc degeneration. Loss of Pcs in the nax cerebellum is compartmentalized and harmonized to the classic pattern of gene expression of the cerebellum in the wild type mouse. Usually, degeneration starts in the anterior and posterior zones and continues to the central and nodular zones of cerebellum. Studies have suggested that the p75 neurotrophin receptor (NTR plays a role in Pc degeneration; thus, in this study, we investigated the p75NTR pattern and protein expression in the cerebellum of the nax mutant mouse. Despite massive Pc degeneration that was observed in the nax mouse cerebellum, p75NTR pattern expression was similar to the HSP25 pattern in nax mice and comparable with wild type sibling cerebellum. In addition, immunoblot analysis of p75NTR protein expression did not show any significant difference between nax and wild type sibling (p > 0.5. In comparison with wild type counterparts, p75NTR pattern expression is aligned with the fundamental cytoarchitecture organization of the cerebellum and is unchanged in the nax mouse cerebellum despite the severe neurodevelopmental disorder accompanied with Pc degeneration.

Anti-Muellerian hormone, inhibin A, gonadotropins, and gonadotropin receptors in bull calves after partial scrotal resection, orchidectomy, and Burdizzo castration.

Science.gov (United States)

Scarlet, Dragos; Aurich, Christine; Ille, Natascha; Walter, Ingrid; Weber, Corinna; Pieler, Dagmar; Peinhopf, Walter; Wohlsein, Peter; Aurich, Jörg

2017-01-01

Eight-week-old calves were either castrated by partial scrotal resection (SR) without removing the testes (n = 10), Burdizzo (BZ) clamp (n = 10), orchidectomy (OR; n = 10), or were left gonad intact as controls (CO; n = 10). Concentrations of anti-Muellerian hormone (AMH), inhibin A, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in plasma were determined from 16 to 48 weeks of age. At 18 months, testes of SR, BZ, and CO bulls were obtained and the immunolocalization of LH and FSH receptors and AMH analyzed. Concentration of AMH in plasma of CO and SR bulls decreased with increasing age (P < 0.001). A similar AMH profile in CO and SR indicates that SR did not induce a true cryptorchid state. In groups OR and BZ, AMH was undetectable. Plasma inhibin concentration was higher in groups CO and SR than BZ and OR (P < 0.001). Plasma LH and FSH concentrations decreased over time (P < 0.001) and were higher in groups BZ and OR than SR and CO (P < 0.001). In the testes, immunolabeling for AMH existed in Sertoli cells of CO and SR but not BZ bulls. FSH receptors were localized in Sertoli cells, Leydig cells, spermatocytes, and the epididymis of CO and SR animals, whereas LH receptors were restricted to Leydig cells. In BZ animals, FSH and LH receptors and AMH were absent, indicating complete testicular degeneration. In conclusion, AMH is a more reliable marker for the presence of testicular tissue in bulls than inhibin. Scrotal resection did not induce a true inguinal cryptorchid state but affected testicular responsiveness to gonadotropic stimulation. Copyright © 2016 Elsevier Inc. All rights reserved.

Sex-specific hormone receptors in urothelial carcinomas of the human urinary bladder: a comparative analysis of clinicopathological features and survival outcomes according to receptor expression.

Science.gov (United States)

Tuygun, Can; Kankaya, Duygu; Imamoglu, Abdurrahim; Sertcelik, Ayse; Zengin, Kursad; Oktay, Murat; Sertcelik, Nurettin

2011-01-01

To investigate the expression of sex-specific hormone receptors in normal bladder urothelium and urothelial carcinomas (UCs) of the bladder, and to analyze clinicopathological features and survival outcomes according to receptor expression. We evaluated the clinical data and tumor specimens of 139 patients with bladder cancer (BC). In addition, 72 samples of normal urothelium were included. Immunohistochemistry was performed using streptavidin-biotin peroxidase method, a monoclonal androgen receptor (AR), and an estrogen receptor-β (ERβ) antibody on paraffin-embedded tissue sections. Expression levels of each receptor were assessed by evaluating 500 tumor cells for each case and the percentage of positively-stained nuclei was recorded. None of the 58 male control cases showed any AR and ERβ expression. Five (35, 71%) of the 14 female control cases expressed ERβ. Of the 139 patients with UCs, 71 (51, 07%) expressed AR (62 male vs. 9 female; P = 0.413) and 44 (31, 65%) (39 male vs. 5 female; P = 0.402) showed ERβ expression (P receptors alone cannot be responsible for gender differences in BC rates because they were expressed in similar rates in both sexes. Copyright © 2011 Elsevier Inc. All rights reserved.

Mechanisms of action of nonpeptide hormones on resveratrol-induced antiproliferation of cancer cells.

Science.gov (United States)

Lin, Hung-Yun; Hsieh, Meng-Ti; Cheng, Guei-Yun; Lai, Hsuan-Yu; Chin, Yu-Tang; Shih, Ya-Jung; Nana, André Wendindondé; Lin, Shin-Ying; Yang, Yu-Chen S H; Tang, Heng-Yuan; Chiang, I-Jen; Wang, Kuan

2017-09-01

Nonpeptide hormones, such as thyroid hormone, dihydrotestosterone, and estrogen, have been shown to stimulate cancer proliferation via different mechanisms. Aside from their cytosolic or membrane-bound receptors, there are receptors on integrin α v β 3 for nonpeptide hormones. Interaction between hormones and integrin α v β 3 can induce signal transduction and eventually stimulate cancer cell proliferation. Resveratrol induces inducible COX-2-dependent antiproliferation via integrin α v β 3 . Resveratrol and hormone-induced signals are both transduced by activated extracellular-regulated kinases 1 and 2 (ERK1/2); however, hormones promote cell proliferation, while resveratrol induces antiproliferation in cancer cells. Hormones inhibit resveratrol-stimulated phosphorylation of p53 on Ser15, resveratrol-induced nuclear COX-2 accumulation, and formation of p53-COX-2 nuclear complexes. Subsequently, hormones impair resveratrol-induced COX-2-/p53-dependent gene expression. The inhibitory effects of hormones on resveratrol action can be blocked by different antagonists of specific nonpeptide hormone receptors but not integrin α v β 3 blockers. Results suggest that nonpeptide hormones inhibit resveratrol-induced antiproliferation in cancer cells downstream of the interaction between ligand and receptor and ERK1/2 activation to interfere with nuclear COX-2 accumulation. Thus, the surface receptor sites for resveratrol and nonpeptide hormones are distinct and can induce discrete ERK1/2-dependent downstream antiproliferation biological activities. It also indicates the complex pathways by which antiproliferation is induced by resveratrol in various physiological hormonal environments. . © 2017 New York Academy of Sciences.

Amenorrhea secondary to a vismodegib-induced blockade of follicle-stimulating hormone-receptor activation.

Science.gov (United States)

Strasswimmer, John; Latimer, Benjamin; Ory, Steven

2014-08-01

To report a novel mechanism suggestive of early ovarian failure secondary to the anti-tumor hedgehog-pathway inhibitor vismodegib. Case report and literature review. Academic and private dermatology and fertility practices. A 34-year-old nulliparous woman with locally advanced basal cell carcinomas who became amenorrheic while receiving oral therapy with vismodegib. Physical examination and endocrine evaluation. Elevated follicle-stimulating hormone (FSH) and low estrogen in the setting of a normal anti-Müllerian hormone. FSH was elevated; estrogen was low. Preantral follicles were detected and anti-Müllerian hormone activity was normal. Menses resumed 5 weeks after cessation of therapy. Vismodegib, a first-in-class inhibitor of the hedgehog signaling pathway is indicated for advanced basal cell carcinoma and is associated with amenorrhea. The mechanism is unknown; it has some features of ovarian failure but preserves ovarian potential through blockading of FSH-receptor-dependent signal transduction. This effect appears to be rapidly reversible upon cessation of therapy. Vismodegib and related compounds may have potential for a role in intervention for gynecologic and endocrine disorders and in therapy for other issues involving FSH-dependent function. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Covalent modification of mutant rat P2X2 receptors with a thiol-reactive fluorophore allows channel activation by zinc or acidic pH without ATP.

Directory of Open Access Journals (Sweden)

Shlomo S Dellal

Full Text Available Rat P2X2 receptors open at an undetectably low rate in the absence of ATP. Furthermore, two allosteric modulators, zinc and acidic pH, cannot by themselves open these channels. We describe here the properties of a mutant receptor, K69C, before and after treatment with the thiol-reactive fluorophore Alexa Fluor 546 C(5-maleimide (AM546. Xenopus oocytes expressing unmodified K69C were not activated under basal conditions nor by 1,000 µM ATP. AM546 treatment caused a small increase in the inward holding current which persisted on washout and control experiments demonstrated this current was due to ATP independent opening of the channels. Following AM546 treatment, zinc (100 µM or acidic external solution (pH 6.5 elicited inward currents when applied without any exogenous ATP. In the double mutant K69C/H319K, zinc elicited much larger inward currents, while acidic pH generated outward currents. Suramin, which is an antagonist of wild type receptors, behaved as an agonist at AM546-treated K69C receptors. Several other cysteine-reactive fluorophores tested on K69C did not cause these changes. These modified receptors show promise as a tool for studying the mechanisms of P2X receptor activation.

A Macrocyclic Agouti-Related Protein/[Nle4, DPhe7]α-Melanocyte Stimulating Hormone Chimeric Scaffold Produces Sub-nanomolar Melanocortin Receptor Ligands

OpenAIRE

Ericson, Mark D.; Freeman, Katie T.; Schnell, Sathya M.; Haskell-Luevano, Carrie

2017-01-01

The melanocortin system consists of five receptor subtypes, endogenous agonists, and naturally occurring antagonists. These receptors and ligands have been implicated in numerous biological pathways including processes linked to obesity and food intake. Herein, a truncation structure-activity relationship study of chimeric agouti-related protein (AGRP)/[Nle4, DPhe7]α-Melanocyte Stimulating Hormone (NDP-MSH) ligands is reported. The tetrapeptide His-DPhe-Arg-Trp or tripeptide DPhe-Arg-Trp repl...

Thyroid hormone and retinoid X receptor function and expression during sea lamprey (Petromyzon marinus) metamorphosis.

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Manzon, Lori A; Youson, John H; Holzer, Guillaume; Staiano, Leopoldo; Laudet, Vincent; Manzon, Richard G

2014-08-01

Sea lampreys (Petromyzon marinus) are members of the ancient class Agnatha and undergo a metamorphosis that transforms blind, sedentary, filter-feeding larvae into free-swimming, parasitic juveniles. Thyroid hormones (THs) appear to be important for lamprey metamorphosis, however, serum TH concentrations are elevated in the larval phase, decline rapidly during early metamorphosis and remain low until metamorphosis is complete; these TH fluctuations are contrary to those of other metamorphosing vertebrates. Moreover, thyroid hormone synthesis inhibitors (goitrogens) induce precocious metamorphosis and exogenous TH treatments disrupt natural metamorphosis in P. marinus. Given that THs exert their effects by binding to TH nuclear receptors (TRs) that often act as heterodimers with retinoid X receptors (RXRs), we cloned and characterized these receptors from P. marinus and examined their expression during metamorphosis. Two TRs (PmTR1 and PmTR2) and three RXRs (PmRXRs) were isolated from P. marinus cDNA. Phylogenetic analyses group the PmTRs together on a branch prior to the gnathostome TRα/β split. The three RXRs also group together, but our data indicated that these transcripts are most likely either allelic variants of the same gene locus, or the products of a lamprey-specific duplication event. Importantly, these P. marinus receptors more closely resemble vertebrate as opposed to invertebrate chordate receptors. Functional analysis revealed that PmTR1 and PmTR2 can activate transcription of TH-responsive genes when treated with nanomolar concentrations of TH and they have distinct pharmacological profiles reminiscent of vertebrate TRβ and TRα, respectively. Also similar to other metamorphosing vertebrates, expression patterns of the PmTRs during lamprey metamorphosis suggest that PmTR1 has a dynamic, tissue-specific expression pattern that correlates with tissue morphogenesis and biochemical changes and PmTR2 has a more uniform expression pattern. This TR

Lateral septum growth hormone secretagogue receptor affects food intake and motivation for sucrose reinforcement.

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Terrill, Sarah J; Wall, Kaylee D; Medina, Nelson D; Maske, Calyn B; Williams, Diana L

2018-03-28

The hormone ghrelin promotes eating and is widely considered to be a hunger signal. Ghrelin receptors, growth hormone secretagogue receptors (GHSRs), are found in a number of specific regions throughout the brain, including the lateral septum (LS), an area not traditionally associated with the control of feeding. Here we investigated whether GHSRs in the LS play a role in the control of food intake. We examined the feeding effects of ghrelin and the GHSR antagonists ([D-Lys3]-GHRP-6 and JMV 2959), at doses subthreshold for effect when delivered to the lateral ventricle. Intra-LS ghrelin significantly increased chow intake during the mid-light phase, suggesting that pharmacologic activation of LS GHSRs promotes feeding. Conversely, GHSR antagonist delivered to the LS shortly before dark onset significantly reduced chow intake. These data support the hypothesis that exogenous and endogenous stimulation of GHSRs in the LS influence feeding. Ghrelin is known to affect motivation for food, and the dorsal subdivision of LS (dLS) has been shown to play a role in motivation. Thus, we investigated the role of dLS GHSRs in motivation for food reward by examining operant responding for sucrose on a progressive ratio (PR) schedule. Intra-dLS ghrelin increased PR responding for sucrose, while blockade of LS GHSRs did not affect responding in either a fed or fasted state. Together these findings for the first time substantiate the LS as a site of action for ghrelin signaling in the control of food intake.

Influence of music on steroid hormones and the relationship between receptor polymorphisms and musical ability: a pilot study.

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Fukui, Hajime; Toyoshima, Kumiko

2013-01-01

Studies have shown that music confers plasticity to the brain. In a preliminary pilot study, we examined the effect of music listening on steroid hormones and the relationship between steroid hormone receptor polymorphisms and musical ability. Twenty-one subjects (10 males and 11 females) were recruited and divided into musically talented and control groups. The subjects selected (1) music they preferred (chill-inducing music) and (2) music they did not like. Before and after the experiments, saliva was collected to measure the levels of steroid hormones such as testosterone, estradiol, and cortisol. DNA was also isolated from the saliva samples to determine the androgen receptor (AR) and arginine vasopressin receptor 1A genotypes. Advanced Measures of Music Audiation (AMMA) was used to determine the musical ability of the subjects. With both types of music, the cortisol levels decreased significantly in both sexes. The testosterone (T) levels declined in males when they listened to both types of music. In females, the T levels increased in those listening to chill-inducing music but declined when they listened to music they disliked. However, these differences were not significant. The 17-beta estradiol levels increased in males with both types of music, whereas the levels increased with chill-inducing music but declined with disliked music in females. The AMMA scores were higher for the short repeat length-type AR than for the long repeat length-type. Comparisons of AR polymorphisms and T levels before the experiments showed that the T levels were within the low range in the short repeat length-type group and there was a positive relationship with the repeat length, although it was not significant. This is the first study conducted in humans to analyze the relationships between the AR gene, T levels, and musical ability.

Disruption of growth hormone receptor gene causes diminished pancreatic islet size and increased insulin sensitivity in mice.

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Liu, Jun-Li; Coschigano, Karen T; Robertson, Katie; Lipsett, Mark; Guo, Yubin; Kopchick, John J; Kumar, Ujendra; Liu, Ye Lauren

2004-09-01

Growth hormone, acting through its receptor (GHR), plays an important role in carbohydrate metabolism and in promoting postnatal growth. GHR gene-deficient (GHR(-/-)) mice exhibit severe growth retardation and proportionate dwarfism. To assess the physiological relevance of growth hormone actions, GHR(-/-) mice were used to investigate their phenotype in glucose metabolism and pancreatic islet function. Adult GHR(-/-) mice exhibited significant reductions in the levels of blood glucose and insulin, as well as insulin mRNA accumulation. Immunohistochemical analysis of pancreatic sections revealed normal distribution of the islets despite a significantly smaller size. The average size of the islets found in GHR(-/-) mice was only one-third of that in wild-type littermates. Total beta-cell mass was reduced 4.5-fold in GHR(-/-) mice, significantly more than their body size reduction. This reduction in pancreatic islet mass appears to be related to decreases in proliferation and cell growth. GHR(-/-) mice were different from the human Laron syndrome in serum insulin level, insulin responsiveness, and obesity. We conclude that growth hormone signaling is essential for maintaining pancreatic islet size, stimulating islet hormone production, and maintaining normal insulin sensitivity and glucose homeostasis.

Growth inhibition of tumor cells in vitro by using monoclonal antibodies against gonadotropin-releasing hormone receptor.

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Lee, Gregory; Ge, Bixia

2010-07-01

As the continuation of a previous study, synthetic peptides corresponding to the extracellular domains of human gonadotropin-releasing hormone (GnRH) receptor were used to generate additional monoclonal antibodies which were further characterized biochemically and immunologically. Among those identified to recognize GnRH receptor, monoclonal antibodies designated as GHR-103, GHR-106 and GHR-114 were found to exhibit high affinity (Kd L37), when cancer cells were incubated with GnRH or GHR-106. The widespread expressions of GnRH receptor in almost all of the studied human cancer cell lines were also demonstrated by RT-PCR and Western blot assay, as well as indirect immunofluorescence assay with either of these monoclonal antibodies as the primary antibody. In view of the longer half life of antibodies as compared to that of GnRH or its analogs, anti-GnRH receptor monoclonal antibodies in humanized forms could function as GnRH analogs and serve as an ideal candidate of anti-cancer drugs for therapeutic treatments of various cancers in humans as well as for fertility regulations.

Clathrin-dependent internalization, signaling, and metabolic processing of guanylyl cyclase/natriuretic peptide receptor-A.

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Somanna, Naveen K; Mani, Indra; Tripathi, Satyabha; Pandey, Kailash N

2018-04-01

Cardiac hormones, atrial and brain natriuretic peptides (ANP and BNP), have pivotal roles in renal hemodynamics, neuroendocrine signaling, blood pressure regulation, and cardiovascular homeostasis. Binding of ANP and BNP to the guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) induces rapid internalization and trafficking of the receptor via endolysosomal compartments, with concurrent generation of cGMP. However, the mechanisms of the endocytotic processes of NPRA are not well understood. The present study, using 125 I-ANP binding assay and confocal microscopy, examined the function of dynamin in the internalization of NPRA in stably transfected human embryonic kidney-293 (HEK-293) cells. Treatment of recombinant HEK-293 cells with ANP time-dependently accelerated the internalization of receptor from the cell surface to the cell interior. However, the internalization of ligand-receptor complexes of NPRA was drastically decreased by the specific inhibitors of clathrin- and dynamin-dependent receptor internalization, almost 85% by monodansylcadaverine, 80% by chlorpromazine, and 90% by mutant dynamin, which are specific blockers of endocytic vesicle formation. Visualizing the internalization of NPRA and enhanced GFP-tagged NPRA in HEK-293 cells by confocal microscopy demonstrated the formation of endocytic vesicles after 5 min of ANP treatment; this effect was blocked by the inhibitors of clathrin and by mutant dynamin construct. Our results suggest that NPRA undergoes internalization via clathrin-mediated endocytosis as part of its normal itinerary, including trafficking, signaling, and metabolic degradation.

Serotonin hyperinnervation and upregulated 5-HT2A receptor expression and motor-stimulating function in nigrostriatal dopamine-deficient Pitx3 mutant mice.

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Li, Li; Qiu, Guozhen; Ding, Shengyuan; Zhou, Fu-Ming

2013-01-23

The striatum receives serotonin (5-hydroxytryptamine, 5-HT) innervation and expresses 5-HT2A receptors (5-HT2ARs) and other 5-HT receptors, raising the possibility that the striatal 5-HT system may undergo adaptive changes after chronic severe dopamine (DA) loss and contribute to the function and dysfunction of the striatum. Here we show that in transcription factor Pitx3 gene mutant mice with a selective, severe DA loss in the dorsal striatum mimicking the DA denervation in late Parkinson's disease (PD), both the 5-HT innervation and the 5-HT2AR mRNA expression were increased in the dorsal striatum. Functionally, while having no detectable motor effect in wild type mice, the 5-HT2R agonist 2,5-dimethoxy-4-iodoamphetamine increased both the baseline and l-dopa-induced normal ambulatory and dyskinetic movements in Pitx3 mutant mice, whereas the selective 5-HT2AR blocker volinanserin had the opposite effects. These results demonstrate that Pitx3 mutant mice are a convenient and valid mouse model to study the compensatory 5-HT upregulation following the loss of the nigrostriatal DA projection and that the upregulated 5-HT2AR function in the DA deficient dorsal striatum may enhance both normal and dyskinetic movements. Copyright © 2012 Elsevier B.V. All rights reserved.

Candesartan decreases the sympatho-adrenal and hormonal response to isolation stress

Directory of Open Access Journals (Sweden)

Ines Armando

2001-03-01

Full Text Available A change from group housing to isolation in unfamiliar metabolic cages represents, for rodents, a significant emotional stress. We studied the effect of candesartan, a peripheral and central angiotensin II AT1-receptor antagonist, on the hormonal and sympathetic response to acute isolation. We pretreated rats with 1 mg/kg/day candesartan for 13 days via subcutaneously implanted osmotic minipumps, followed by 24-hour isolation in individual metabolic cages. We measured brain, pituitary and adrenal angiotensin II (Ang II receptor binding by quantitative autoradiography and adrenal hormones and catecholamines by RIA and HPLC. Isolation increased adrenal catecholamines, aldosterone and corticosterone, AT1-receptor binding in the zona glomerulosa and AT2-receptor binding in the adrenal medulla. Candesartan pretreatment decreased adrenal catecholamines, aldosterone and corticosterone, AT1-receptor binding in adrenal zona glomerulosa and medulla, pituitary gland and the hypothalamic paraventricular nucleus, and AT2-receptor binding in adrenal medulla, but increased AT2-receptor binding in zona glomerulosa. We conclude that peripheral and central AT1-receptor blockade with candesartan decreases the sympatho-adrenal and hormonal response to acute stress. Our results indicate that Ang II is an important stress hormone and suggest that blockade of the physiologically active AT 1-receptors could influence stress-related disorders.

Circulating sex hormones and gene expression of subcutaneous adipose tissue oestrogen and alpha-adrenergic receptors in HIV-lipodystrophy: implications for fat distribution

DEFF Research Database (Denmark)

Andersen, Ove; Pedersen, Steen B; Svenstrup, Birgit

2007-01-01

of alpha2A-adrenergic-receptor correlated positively with expression of oestrogen-receptor-alpha. CONCLUSIONS: The results fit the hypothesis that sex hormones play a role in altered fat distribution and insulin sensitivity of male patients with HIV-lipodystrophy. The effect of oestradiol...... patients, correlated positively with both plasma oestradiol and testosterone (n = 31). Glycerol concentration during clamp (a marker of lipolysis) correlated inversely with expression of alpha2A-adrenergic-receptor, ratio of subcutaneous to total abdominal fat mass, and limb fat, respectively. Expression...

Vitamin-caused faulty perinatal hormonal imprinting and its consequences in adult age.

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Csaba, G

2017-09-01

Lipid-soluble vitamins (vitamins A, D, E, and K) are actually hormones (exohormones), as they can be directly bound by hormone receptors or are in connection with molecules, which influence hormone receptors. Vitamin D is a transition between endo- and exohormones and the possibility of similar situation in case of other lipid-soluble hormones is discussed. The perinatal exposition with these "vitamins" can cause faulty perinatal hormonal imprinting with similar consequences as the faulty imprinting by the synthetic endohormones, members of the same hormone family or industrial, communal, or medical endocrine disruptors. The faulty imprinting leads to late (lifelong) consequences with altered hormone binding by receptors, altered sexuality, brain function, immunity, bone development, and fractures, etc. In addition, as hormonal imprinting is an epigenetic process, the effect of a single exposure by fat-soluble vitamins is inherited to the progeny generations. As vitamins are handled differently from hormones; however, perinatal treatments take place frequently and sometimes it is forced, the negative late effect of faulty perinatal vitamin-caused hormonal imprinting must be considered.

The gene encoding the melanin-concentrating hormone receptor 1 is associated with schizophrenia in a Danish case-control sample

DEFF Research Database (Denmark)

Demontis, Ditte; Nyegaard, Mette; Christensen, Jane H

2012-01-01

OBJECTIVE: The MCHR1 gene encoding the melanin-concentrating hormone receptor 1 is located on chromosome 22q13.2 and has previously been associated with schizophrenia in a study of cases and controls from the Faroe Islands and Scotland. Herein we report an association between variations in the MCHR...

Gastrointestinal hormone research - with a Scandinavian annotation

DEFF Research Database (Denmark)

Rehfeld, Jens F

2015-01-01

Gastrointestinal hormones are peptides released from neuroendocrine cells in the digestive tract. More than 30 hormone genes are currently known to be expressed in the gut, which makes it the largest hormone-producing organ in the body. Modern biology makes it feasible to conceive the hormones...... as a blood-borne hormone, a neurotransmitter, a local growth factor or a fertility factor. The targets of gastrointestinal hormones are specific G-protein-coupled receptors that are expressed in the cell membranes also outside the digestive tract. Thus, gut hormones not only regulate digestive functions...

Nuclear hormone receptor NHR-49 controls fat consumption and fatty acid composition in C. elegans.

Directory of Open Access Journals (Sweden)

Marc R Van Gilst

2005-02-01

Full Text Available Mammalian nuclear hormone receptors (NHRs, such as liver X receptor, farnesoid X receptor, and peroxisome proliferator-activated receptors (PPARs, precisely control energy metabolism. Consequently, these receptors are important targets for the treatment of metabolic diseases, including diabetes and obesity. A thorough understanding of NHR fat regulatory networks has been limited, however, by a lack of genetically tractable experimental systems. Here we show that deletion of the Caenorhabditis elegans NHR gene nhr-49 yielded worms with elevated fat content and shortened life span. Employing a quantitative RT-PCR screen, we found that nhr-49 influenced the expression of 13 genes involved in energy metabolism. Indeed, nhr-49 served as a key regulator of fat usage, modulating pathways that control the consumption of fat and maintain a normal balance of fatty acid saturation. We found that the two phenotypes of the nhr-49 knockout were linked to distinct pathways and were separable: The high-fat phenotype was due to reduced expression of enzymes in fatty acid beta-oxidation, and the shortened adult life span resulted from impaired expression of a stearoyl-CoA desaturase. Despite its sequence relationship with the mammalian hepatocyte nuclear factor 4 receptor, the biological activities of nhr-49 were most similar to those of the mammalian PPARs, implying an evolutionarily conserved role for NHRs in modulating fat consumption and composition. Our findings in C. elegans provide novel insights into how NHR regulatory networks are coordinated to govern fat metabolism.

Nuclear hormone receptor NHR-49 controls fat consumption and fatty acid composition in C. elegans.

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Van Gilst, Marc R; Hadjivassiliou, Haralambos; Jolly, Amber; Yamamoto, Keith R

2005-02-01

Mammalian nuclear hormone receptors (NHRs), such as liver X receptor, farnesoid X receptor, and peroxisome proliferator-activated receptors (PPARs), precisely control energy metabolism. Consequently, these receptors are important targets for the treatment of metabolic diseases, including diabetes and obesity. A thorough understanding of NHR fat regulatory networks has been limited, however, by a lack of genetically tractable experimental systems. Here we show that deletion of the Caenorhabditis elegans NHR gene nhr-49 yielded worms with elevated fat content and shortened life span. Employing a quantitative RT-PCR screen, we found that nhr-49 influenced the expression of 13 genes involved in energy metabolism. Indeed, nhr-49 served as a key regulator of fat usage, modulating pathways that control the consumption of fat and maintain a normal balance of fatty acid saturation. We found that the two phenotypes of the nhr-49 knockout were linked to distinct pathways and were separable: The high-fat phenotype was due to reduced expression of enzymes in fatty acid beta-oxidation, and the shortened adult life span resulted from impaired expression of a stearoyl-CoA desaturase. Despite its sequence relationship with the mammalian hepatocyte nuclear factor 4 receptor, the biological activities of nhr-49 were most similar to those of the mammalian PPARs, implying an evolutionarily conserved role for NHRs in modulating fat consumption and composition. Our findings in C. elegans provide novel insights into how NHR regulatory networks are coordinated to govern fat metabolism.

Neuroprotective Actions of Ghrelin and Growth Hormone Secretagogues

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Frago, Laura M.; Baquedano, Eva; Argente, Jesús; Chowen, Julie A.

2011-01-01

The brain incorporates and coordinates information based on the hormonal environment, receiving information from peripheral tissues through the circulation. Although it was initially thought that hormones only acted on the hypothalamus to perform endocrine functions, it is now known that they in fact exert diverse actions on many different brain regions including the hypothalamus. Ghrelin is a gastric hormone that stimulates growth hormone secretion and food intake to regulate energy homeostasis and body weight by binding to its receptor, growth hormone secretagogues–GH secretagogue-receptor, which is most highly expressed in the pituitary and hypothalamus. In addition, ghrelin has effects on learning and memory, reward and motivation, anxiety, and depression, and could be a potential therapeutic agent in neurodegenerative disorders where excitotoxic neuronal cell death and inflammatory processes are involved. PMID:21994488

Extended and structurally supported insights into extracellular hormone binding, signal transduction and organization of the thyrotropin receptor.

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Gerd Krause

Full Text Available The hormone thyrotropin (TSH and its receptor (TSHR are crucial for the growth and function of the thyroid gland. The TSHR is evolutionary linked with the receptors of follitropin (FSHR and lutropin/choriogonadotropin (LHR and their sequences and structures are similar. The extracellular region of TSHR contains more than 350 amino acids and binds hormone and antibodies. Several important questions related to functions and mechanisms of TSHR are still not comprehensively understood. One major reason for these open questions is the lack of any structural information about the extracellular segment of TSHR that connects the N-terminal leucine-rich repeat domain (LRRD with the transmembrane helix (TMH 1, the hinge region. It has been shown experimentally that this segment is important for fine tuning of signaling and ligand interactions. A new crystal structure containing most of the extracellular hFSHR region in complex with hFSH has recently been published. Now, we have applied these new structural insights to the homologous TSHR and have generated a structural model of the TSHR LRRD/hinge-region/TSH complex. This structural model is combined and evaluated with experimental data including hormone binding (bTSH, hTSH, thyrostimulin, super-agonistic effects, antibody interactions and signaling regulation. These studies and consideration of significant and non-significant amino acids have led to a new description of mechanisms at the TSHR, including ligand-induced displacements of specific hinge region fragments. This event triggers conformational changes at a convergent center of the LRRD and the hinge region, activating an "intramolecular agonistic unit" close to the transmembrane domain.

Extended and structurally supported insights into extracellular hormone binding, signal transduction and organization of the thyrotropin receptor.

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Krause, Gerd; Kreuchwig, Annika; Kleinau, Gunnar

2012-01-01

The hormone thyrotropin (TSH) and its receptor (TSHR) are crucial for the growth and function of the thyroid gland. The TSHR is evolutionary linked with the receptors of follitropin (FSHR) and lutropin/choriogonadotropin (LHR) and their sequences and structures are similar. The extracellular region of TSHR contains more than 350 amino acids and binds hormone and antibodies. Several important questions related to functions and mechanisms of TSHR are still not comprehensively understood. One major reason for these open questions is the lack of any structural information about the extracellular segment of TSHR that connects the N-terminal leucine-rich repeat domain (LRRD) with the transmembrane helix (TMH) 1, the hinge region. It has been shown experimentally that this segment is important for fine tuning of signaling and ligand interactions. A new crystal structure containing most of the extracellular hFSHR region in complex with hFSH has recently been published. Now, we have applied these new structural insights to the homologous TSHR and have generated a structural model of the TSHR LRRD/hinge-region/TSH complex. This structural model is combined and evaluated with experimental data including hormone binding (bTSH, hTSH, thyrostimulin), super-agonistic effects, antibody interactions and signaling regulation. These studies and consideration of significant and non-significant amino acids have led to a new description of mechanisms at the TSHR, including ligand-induced displacements of specific hinge region fragments. This event triggers conformational changes at a convergent center of the LRRD and the hinge region, activating an "intramolecular agonistic unit" close to the transmembrane domain.

Not all elevated hormones are toxic: A case of thyroid hormone resistance

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Rajeev Philip

2016-01-01

Full Text Available Resistance to thyroid hormone syndrome (RTH is a rare disorder and is usually inherited as dominantly negative autosomal trait. RTH is caused by mutations in the thyroid hormone receptor beta. Patients with RTH usually do not have signs and symptoms of thyrotoxicosis, but the thyroid function test shows an elevated T3 and T4, which get misinterpreted as hyperthyroidism, resulting in unnecessary treatment.

Investigational hormone receptor agonists as ongoing female contraception: a focus on selective progesterone receptor modulators in early clinical development.

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Nelson, Anita L

2015-01-01

As efforts are made to continue to increase the safety of contraceptive methods, those without estrogen have attracted new attention. Progestin-only options are available in many delivery systems, but most cause disturbed bleeding patterns. For gynecologic patients, selective progesterone receptor modulators (SPRMs) have been approved for medical abortion, for ovulation suppression in emergency contraception, and for the treatment of heavy menstrual bleeding due to leiomyoma. This article discusses the role of SPRMs in controlling fertility on an ongoing basis with particular emphasis on mifepristone and ulipristal acetate (UPA), since none of the other compounds has progressed out of early Phase I - II testing. It also discusses important information about the mechanisms of action and safety of these two SPRMs. Of all the investigational hormone agonist/antagonists, SPRMs have demonstrated the greatest potential as ongoing female contraceptives. They have the ability to suppress ovulation after initiation of the luteinizing hormone (LH) surge without affecting ovarian production of estrogen or inducing any significant metabolic changes. SPRMs may well be able to provide longer term contraception as oral agents, vaginal rings, and perhaps even intrauterine devices. UPA has the greatest promise. Current research needs to be expanded.

Hsp70 cochaperones HspBP1 and BAG-1M differentially regulate steroid hormone receptor function.

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Regina T Knapp

Full Text Available Hsp70 binding protein 1 (HspBP1 and Bcl2-associated athanogene 1 (BAG-1, the functional orthologous nucleotide exchange factors of the heat shock protein 70 kilodalton (Hsc70/Hsp70 chaperones, catalyze the release of ADP from Hsp70 while inducing different conformational changes of the ATPase domain of Hsp70. An appropriate exchange rate of ADP/ATP is crucial for chaperone-dependent protein folding processes. Among Hsp70 client proteins are steroid receptors such as the glucocorticoid receptor (GR, the mineralocorticoid receptor (MR, and the androgen receptor (AR. BAG-1 diversely affects steroid receptor activity, while to date the influence of HspBP1 on steroid receptor function is mostly unknown. Here, we compared the influence of HspBP1 and BAG-1M on Hsp70-mediated steroid receptor folding complexes and steroid receptor activity. Coimmunoprecipitation studies indicated preferential binding of Hsp40 and the steroid receptors to BAG-1M as compared to HspBP1. Furthermore, Hsp70 binding to the ligand-binding domain of GR was reduced in the presence of HspBP1 but not in the presence of BAG-1M as shown by pull-down assays. Reporter gene experiments revealed an inhibitory effect on GR, MR, and AR at a wide range of HspBP1 protein levels and at hormone concentrations at or approaching saturation. BAG-1M exhibited a transition from stimulatory effects at low BAG-1M levels to inhibitory effects at higher BAG-1M levels. Overall, BAG-1M and HspBP1 had differential impacts on the dynamic composition of steroid receptor folding complexes and on receptor function with important implications for steroid receptor physiology.

Binding properties of beetal recombinant caprine growth hormone to ...

African Journals Online (AJOL)

SAM

2014-07-23

Jul 23, 2014 ... The aim of the study was to illustrate the radio-receptor assay of beetal recombinant caprine growth hormone (rcGH) ... interaction with microsomal membrane that shall be beneficial to study hormone receptor interactions of other Bovidae .... adding 1 ml of ice cold assay buffer, followed by 1 ml of 25% (w/v).

Identification of a novel ga-related bush mutant in pumpkin (cucurbita moschata duchesne)

International Nuclear Information System (INIS)

Wu, T.; Cao, J.

2015-01-01

Pumpkin (Cucurbita moschata Duchesne) bush mutant plants were characterized by short stems. The sensitivity of pumpkin bush mutant plants to exogenous hormones was identified in this study. Results revealed that internode elongation of bush mutant plants could respond to gibberellins (GA4+7 and GA3), but not to indole acetic acid (IAA) and brassinosteroids (BR); by contrast, the mutant phenotype of bush mutant plants could not be fully rescued by GA4+7 and GA3. The internode of bush mutant plants yielded a lower KS expression level than that of vine plants. Therefore, pumpkin bush mutant plants were designated as GA-related mutant plants eliciting a partial response to GAs; the action of IAA and BR might not be involved in the internode growth of pumpkin bush mutant plants, specifically Cucurbita moschata Duch. (author)

The Role of Thyroid Hormone Signaling in the Prevention of Digestive System Cancers

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Rosalia C. M. Simmen

2013-08-01

Full Text Available Thyroid hormones play a critical role in the growth and development of the alimentary tract in vertebrates. Their effects are mediated by nuclear receptors as well as the cell surface receptor integrin αVβ3. Systemic thyroid hormone levels are controlled via activation and deactivation by iodothyronine deiodinases in the liver and other tissues. Given that thyroid hormone signaling has been characterized as a major effector of digestive system growth and homeostasis, numerous investigations have examined its role in the occurrence and progression of cancers in various tissues of this organ system. The present review summarizes current findings regarding the effects of thyroid hormone signaling on cancers of the esophagus, stomach, liver, pancreas, and colon. Particular attention is given to the roles of different thyroid hormone receptor isoforms, the novel integrin αVβ3 receptor, and thyroid hormone-related nutrients as possible protective agents and therapeutic targets. Future investigations geared towards a better understanding of thyroid hormone signaling in digestive system cancers may provide preventive or therapeutic strategies to diminish risk, improve outcome and avert recurrence in afflicted individuals.

Components of the CCR4-NOT complex function as nuclear hormone receptor coactivators via association with the NRC-interacting Factor NIF-1.

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Garapaty, Shivani; Mahajan, Muktar A; Samuels, Herbert H

2008-03-14

CCR4-NOT is an evolutionarily conserved, multicomponent complex known to be involved in transcription as well as mRNA degradation. Various subunits (e.g. CNOT1 and CNOT7/CAF1) have been reported to be involved in influencing nuclear hormone receptor activities. Here, we show that CCR4/CNOT6 and RCD1/CNOT9, members of the CCR4-NOT complex, potentiate nuclear receptor activity. RCD1 interacts in vivo and in vitro with NIF-1 (NRC-interacting factor), a previously characterized nuclear receptor cotransducer that activates nuclear receptors via its interaction with NRC. As with NIF-1, RCD1 and CCR4 do not directly associate with nuclear receptors; however, they enhance ligand-dependent transcriptional activation by nuclear hormone receptors. CCR4 mediates its effect through the ligand binding domain of nuclear receptors and small interference RNA-mediated silencing of endogenous CCR4 results in a marked decrease in nuclear receptor activation. Furthermore, knockdown of CCR4 results in an attenuated stimulation of RARalpha target genes (e.g. Sox9 and HoxA1) as shown by quantitative PCR assays. The silencing of endogenous NIF-1 also resulted in a comparable decrease in the RAR-mediated induction of both Sox9 and HoxA1. Furthermore, CCR4 associates in vivo with NIF-1. In addition, the CCR4-enhanced transcriptional activation by nuclear receptors is dependent on NIF-1. The small interference RNA-mediated knockdown of NIF-1 blocks the ligand-dependent potentiating effect of CCR4. Our results suggest that CCR4 plays a role in the regulation of certain endogenous RARalpha target genes and that RCD1 and CCR4 might mediate their function through their interaction with NIF-1.

Phosphorylation of the dimeric cytoplasmic domain of the phytosulfokine receptor, PSKR1

KAUST Repository

Muleya, V.

2016-08-04

Phytosulfokines (PSKs) are plant peptide hormones that co-regulate plant growth, differentiation and defense responses. PSKs signal through a plasma membrane localized leucine-rich repeat receptor-like kinase (phytosulfokine receptor 1, PSKR1) that also contains a functional cytosolic guanylate cyclase with its cyclase catalytic center embedded within the kinase domain. To functionally characterize this novel type of overlapping dual catalytic function, we investigated the phosphorylation of PSKR1 in vitro Tandem mass spectrometry of the cytoplasmic domain of PSKR1 (PSKR1cd) revealed at least 11 phosphorylation sites (8 serines, 2 threonines and 1 tyrosine) within the PSKR1cd. Phosphomimetic mutations of three serine residues (Ser686, Ser696 and Ser698) in tandem at the juxta-membrane position resulted in enhanced kinase activity in the on-mutant that was suppressed in the off-mutant, but both mutations reduced guanylate cyclase activity. Both the on and off phosphomimetic mutations of the phosphotyrosine (Tyr888) residue in the activation loop suppressed kinase activity, while neither mutation affected guanylate cyclase activity. Size exclusion and analytical ultracentrifugation analysis of the PSKR1cd suggest that it is reversibly dimeric in solution, which was further confirmed by biflourescence complementation. Taken together, these data suggest that in this novel type of receptor domain architecture, specific phosphorylation and dimerization are possibly essential mechanisms for ligand-mediated catalysis and signaling.

Phosphorylation of the dimeric cytoplasmic domain of the phytosulfokine receptor, PSKR1

KAUST Repository

Muleya, V.; Marondedze, Claudius; Wheeler, J. I.; Thomas, Ludivine; Mok, Y.-F.; Griffin, M. D. W.; Manallack, D. T.; Kwezi, L.; Lilley, K. S.; Gehring, Christoph A; Irving, H. R.

2016-01-01

Phytosulfokines (PSKs) are plant peptide hormones that co-regulate plant growth, differentiation and defense responses. PSKs signal through a plasma membrane localized leucine-rich repeat receptor-like kinase (phytosulfokine receptor 1, PSKR1) that also contains a functional cytosolic guanylate cyclase with its cyclase catalytic center embedded within the kinase domain. To functionally characterize this novel type of overlapping dual catalytic function, we investigated the phosphorylation of PSKR1 in vitro Tandem mass spectrometry of the cytoplasmic domain of PSKR1 (PSKR1cd) revealed at least 11 phosphorylation sites (8 serines, 2 threonines and 1 tyrosine) within the PSKR1cd. Phosphomimetic mutations of three serine residues (Ser686, Ser696 and Ser698) in tandem at the juxta-membrane position resulted in enhanced kinase activity in the on-mutant that was suppressed in the off-mutant, but both mutations reduced guanylate cyclase activity. Both the on and off phosphomimetic mutations of the phosphotyrosine (Tyr888) residue in the activation loop suppressed kinase activity, while neither mutation affected guanylate cyclase activity. Size exclusion and analytical ultracentrifugation analysis of the PSKR1cd suggest that it is reversibly dimeric in solution, which was further confirmed by biflourescence complementation. Taken together, these data suggest that in this novel type of receptor domain architecture, specific phosphorylation and dimerization are possibly essential mechanisms for ligand-mediated catalysis and signaling.

Association between lifetime exposure to passive smoking and risk of breast cancer subtypes defined by hormone receptor status among non-smoking Caucasian women.

Directory of Open Access Journals (Sweden)

Loreta Strumylaite

Full Text Available Tobacco smoking is inconsistently associated with breast cancer. Although some studies suggest that breast cancer risk is related to passive smoking, little is known about the association with breast cancer by tumor hormone receptor status. We aimed to explore the association between lifetime passive smoking and risk of breast cancer subtypes defined by estrogen receptor and progesterone receptor status among non-smoking Caucasian women. A hospital-based case-control study was performed in 585 cases and 1170 controls aged 28-90 years. Information on lifetime passive smoking and other factors was collected via a self-administered questionnaire. Logistic regression was used for analyses restricted to the 449 cases and 930 controls who had never smoked actively. All statistical tests were two-sided. Adjusted odds ratio of breast cancer was 1.01 (95% confidence interval (CI: 0.72-1.41 in women who experienced exposure to passive smoking at work, 1.88 (95% CI: 1.38-2.55 in women who had exposure at home, and 2.80 (95% CI: 1.84-4.25 in women who were exposed at home and at work, all compared with never exposed regularly. Increased risk was associated with longer exposure: women exposed ≤ 20 years and > 20 years had 1.27 (95% CI: 0.97-1.66 and 2.64 (95% CI: 1.87-3.74 times higher risk of breast cancer compared with never exposed (Ptrend 0.05. There was evidence of interaction between passive smoking intensity and menopausal status in both overall group (P = 0.02 and hormone receptor-positive breast cancer group (P < 0.05. In Caucasian women, lifetime exposure to passive smoking is associated with the risk of breast cancer independent of tumor hormone receptor status with the strongest association in postmenopausal women.

Changes in gonadotropin-releasing hormone and gonadotropin-releasing hormone receptor gene expression after an increase in carbon monoxide concentration in the cavernous sinus of male wild boar and pig crossbread.

Science.gov (United States)

Romerowicz-Misielak, M; Tabecka-Lonczynska, A; Koziol, K; Gilun, P; Stefanczyk-Krzymowska, S; Och, W; Koziorowski, M

2016-06-01

Previous studies indicate that there are at least a few regulatory systems involved in photoperiodic synchronisation of reproductive activity, which starts with the retina and ends at the gonadotropin-releasing hormone (GnRH) pulse generator. Recently we have shown indicated that the amount of carbon monoxide (CO) released from the eye into the ophthalmic venous blood depends on the intensity of sunlight. The aim of this study was to test whether changes in the concentration of carbon monoxide in the ophthalmic venous blood may modulate reproductive activity, as measured by changes in GnRH and GnRH receptor gene expression. The animal model used was mature male swine crossbred from wild boars and domestic sows (n = 48). We conducted in vivo experiments to determine the effect of increased CO concentrations in the cavernous sinus of the mammalian perihypophyseal vascular complex on gene expression of GnRH and GnRH receptors as well as serum luteinizing hormone (LH) levels. The experiments were performed during long photoperiod days near the summer solstice (second half of June) and short photoperiod days near the winter solstice (second half of December). These crossbred swine demonstrated a seasonally-dependent marked variation in GnRH and GnRH receptor gene expression and systemic LH levels in response to changes in CO concentration in ophthalmic venous blood. These results seem to confirm the hypothesis of humoral phototransduction as a mechanism for some of bright light's effects in animal chronobiology and the effect of CO on GnRH and GnRH receptor gene expression.

The axolotl (Ambystoma mexicanum), a neotenic amphibian, expresses functional thyroid hormone receptors.

Science.gov (United States)

Safi, Rachid; Bertrand, Stéphanie; Marchand, Oriane; Duffraisse, Marilyne; de Luze, Amaury; Vanacker, Jean-Marc; Maraninchi, Marie; Margotat, Alain; Demeneix, Barbara; Laudet, Vincent

2004-02-01

Neotenic amphibians such as the axolotl (Ambystoma mexicanum) are often unable to undergo metamorphosis under natural conditions. It is thought that neoteny represents a deviation from the standard course of amphibian ontogeny, affecting the thyroid axis at different levels from the central nervous system to peripheral organs. Thyroid hormone receptors (TRs) that bind the thyroid hormone (TH) T(3) have been described in axolotl. However, the full sequences of TR were needed to better characterize the TH response and to be able to assess their functional capacity at the molecular level. We report that each of the alpha and beta axolotl TRs bind both DNA and TH, and they activate transcription in response to TH in a mammalian cell-based transient transfection assay. Moreover, both TRs are expressed in axolotl tissues. Interestingly, each TR gene generates alternatively spliced isoforms, harboring partial or total deletions of the ligand-binding domain, which are expressed in vivo. Further, we found that in the axolotl, TH regulates the expression of stromelysin 3 and collagenase 3, which are TH target genes in Xenopus. Taken together, these results suggest that axolotl TRs are functional and that the molecular basis of neoteny in the axolotl is not linked to a major defect in TH response in peripheral tissues.

Effects of corticotropin-releasing hormone and its antagonist on the gene expression of gonadotrophin-releasing hormone (GnRH) and GnRH receptor in the hypothalamus and anterior pituitary gland of follicular phase ewes.

Science.gov (United States)

Ciechanowska, Magdalena; Łapot, Magdalena; Malewski, Tadeusz; Mateusiak, Krystyna; Misztal, Tomasz; Przekop, Franciszek

2011-01-01

There is no information in the literature regarding the effect of corticotropin-releasing hormone (CRH) on genes encoding gonadotrophin-releasing hormone (GnRH) and the GnRH receptor (GnRHR) in the hypothalamus or on GnRHR gene expression in the pituitary gland in vivo. Thus, the aim of the present study was to investigate, in follicular phase ewes, the effects of prolonged, intermittent infusion of small doses of CRH or its antagonist (α-helical CRH 9-41; CRH-A) into the third cerebral ventricle on GnRH mRNA and GnRHR mRNA levels in the hypothalamo-pituitary unit and on LH secretion. Stimulation or inhibition of CRH receptors significantly decreased or increased GnRH gene expression in the hypothalamus, respectively, and led to different responses in GnRHR gene expression in discrete hypothalamic areas. For example, CRH increased GnRHR gene expression in the preoptic area, but decreased it in the hypothalamus/stalk median eminence and in the anterior pituitary gland. In addition, CRH decreased LH secretion. Blockade of CRH receptors had the opposite effect on GnRHR gene expression. The results suggest that activation of CRH receptors in the hypothalamus of follicular phase ewes can modulate the biosynthesis and release of GnRH through complex changes in the expression of GnRH and GnRHR genes in the hypothalamo-anterior pituitary unit. © CSIRO 2011 Open Access

Transactivation of a cellular promoter by the NS1 protein of the parvovirus minute virus of mice through a putative hormone-responsive element.

OpenAIRE

Vanacker, J M; Corbau, R; Adelmant, G; Perros, M; Laudet, V; Rommelaere, J

1996-01-01

The promoter of the thyroid hormone receptor alpha gene (c-erbA-1) is activated by the nonstructural protein 1 (NS1) of parvovirus minute virus of mice (prototype strain [MVMp]) in ras-transformed FREJ4 cells that are permissive for lytic MVMp replication. This stimulation may be related to the sensitivity of host cells to MVMp, as it does not take place in parental FR3T3 cells, which are resistant to the parvovirus killing effect. The analysis of a series of deletion and point mutants of the...

Discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems

DEFF Research Database (Denmark)

Hansen, Karina Kiilerich; Stafflinger, Elisabeth; Schneider, Martina

2010-01-01

receptors, this is a prominent example of receptor/ligand co-evolution, probably originating from receptor and ligand gene duplications followed by mutations and evolutionary selection, thereby yielding three independent hormonal systems. The ACP signaling system occurs in the mosquitoes A. gambiae, Aedes...

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

Science.gov (United States)

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2005-01-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridiz-ation showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17β-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates. PMID:16367741

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris).

Science.gov (United States)

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2006-04-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homologue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridization showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17beta-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates.

Thyroid-Stimulating Hormone Receptor Antibodies in Pregnancy: Clinical Relevance

Science.gov (United States)

Bucci, Ines; Giuliani, Cesidio; Napolitano, Giorgio

2017-01-01

Graves’ disease is the most common cause of thyrotoxicosis in women of childbearing age. Approximately 1% of pregnant women been treated before, or are being treated during pregnancy for Graves’ hyperthyroidism. In pregnancy, as in not pregnant state, thyroid-stimulating hormone (TSH) receptor (TSHR) antibodies (TRAbs) are the pathogenetic hallmark of Graves’ disease. TRAbs are heterogeneous for molecular and functional properties and are subdivided into activating (TSAbs), blocking (TBAbs), or neutral (N-TRAbs) depending on their effect on TSHR. The typical clinical features of Graves’ disease (goiter, hyperthyroidism, ophthalmopathy, dermopathy) occur when TSAbs predominate. Graves’ disease shows some peculiarities in pregnancy. The TRAbs disturb the maternal as well as the fetal thyroid function given their ability to cross the placental barrier. The pregnancy-related immunosuppression reduces the levels of TRAbs in most cases although they persist in women with active disease as well as in women who received definitive therapy (radioiodine or surgery) before pregnancy. Changes of functional properties from stimulating to blocking the TSHR could occur during gestation. Drug therapy is the treatment of choice for hyperthyroidism during gestation. Antithyroid drugs also cross the placenta and therefore decrease both the maternal and the fetal thyroid hormone production. The management of Graves’ disease in pregnancy should be aimed at maintaining euthyroidism in the mother as well as in the fetus. Maternal and fetal thyroid dysfunction (hyperthyroidism as well as hypothyroidism) are in fact associated with several morbidities. Monitoring of the maternal thyroid function, TRAbs measurement, and fetal surveillance are the mainstay for the management of Graves’ disease in pregnancy. This review summarizes the biochemical, immunological, and therapeutic aspects of Graves’ disease in pregnancy focusing on the role of the TRAbs in maternal and fetal

Thyroid-Stimulating Hormone Receptor Antibodies in Pregnancy: Clinical Relevance

Directory of Open Access Journals (Sweden)

Ines Bucci

2017-06-01

Full Text Available Graves’ disease is the most common cause of thyrotoxicosis in women of childbearing age. Approximately 1% of pregnant women been treated before, or are being treated during pregnancy for Graves’ hyperthyroidism. In pregnancy, as in not pregnant state, thyroid-stimulating hormone (TSH receptor (TSHR antibodies (TRAbs are the pathogenetic hallmark of Graves’ disease. TRAbs are heterogeneous for molecular and functional properties and are subdivided into activating (TSAbs, blocking (TBAbs, or neutral (N-TRAbs depending on their effect on TSHR. The typical clinical features of Graves’ disease (goiter, hyperthyroidism, ophthalmopathy, dermopathy occur when TSAbs predominate. Graves’ disease shows some peculiarities in pregnancy. The TRAbs disturb the maternal as well as the fetal thyroid function given their ability to cross the placental barrier. The pregnancy-related immunosuppression reduces the levels of TRAbs in most cases although they persist in women with active disease as well as in women who received definitive therapy (radioiodine or surgery before pregnancy. Changes of functional properties from stimulating to blocking the TSHR could occur during gestation. Drug therapy is the treatment of choice for hyperthyroidism during gestation. Antithyroid drugs also cross the placenta and therefore decrease both the maternal and the fetal thyroid hormone production. The management of Graves’ disease in pregnancy should be aimed at maintaining euthyroidism in the mother as well as in the fetus. Maternal and fetal thyroid dysfunction (hyperthyroidism as well as hypothyroidism are in fact associated with several morbidities. Monitoring of the maternal thyroid function, TRAbs measurement, and fetal surveillance are the mainstay for the management of Graves’ disease in pregnancy. This review summarizes the biochemical, immunological, and therapeutic aspects of Graves’ disease in pregnancy focusing on the role of the TRAbs in maternal and

Progress of measurement of hormones

International Nuclear Information System (INIS)

Ohsawa, Nakaaki

1977-01-01

Description was made as to an outline of the theory of radioreceptor assay (RRA) in which hormone receptor was used as specific binding protein, as same as the theory of RIA, and as to its practical use. Meaning of RRA for measurement of hormones in consideration of the site of immunological and biological activation and meaning of difference in measurement values between this method and in RIA in the same materials, were mentioned, and effectiveness of use of this method together with RIA was described. Detection of receptor site, analysis of binding specificity, and numerical calculation were mentioned as receptor analysis by this method. As practical use of these functions, arrangement mechanism of receptor, and analysis of abnormality were mentioned. Especially, analysis of testicular feminization syndrome, insulinresistenter diabetes, hyperthyroidism, and myasthenia gravis, and relationship between these diseases and autoimmune diseases were described, and clinical meaning of this method in internal medicine and surgery was mentioned. (Kanao, N.)

In Situ Hybridization Method Reveals (Pro)renin Receptor Expressing Cells in the Pituitary Gland of Rats: Correlation with Anterior Pituitary Hormones.

Science.gov (United States)

Takahashi, Kazuhiro; Yatabe, Megumi; Fujiwara, Ken; Hirose, Takuo; Totsune, Kazuhito; Yashiro, Takashi

2013-02-28

Expression of (pro)renin receptor ((P)RR), a specific receptor for renin and prorenin, was studied in rat pituitary gland. In situ hybridization showed that cells expressing (P)RR mRNA were widely distributed in the anterior lobe and intermediate lobe of the pituitary gland. Double-staining using in situ hybridization for (P)RR mRNA and immunohistochemistry for the pituitary hormones showed that (P)RR mRNA was expressed in most of the GH cells and ACTH cells in the anterior lobe. (P)RR mRNA was also expressed in a few prolactin cells and TSH cells, but not in LH cells. The present study has shown for the first time the distribution of (P)RR mRNA expressing cells in the rat pituitary gland. These findings suggest that (P)RR plays physiological roles in the pituitary gland, such as the modulation of the pituitary hormone secretion.

In Situ Hybridization Method Reveals (Pro)renin Receptor Expressing Cells in the Pituitary Gland of Rats: Correlation with Anterior Pituitary Hormones

International Nuclear Information System (INIS)

Takahashi, Kazuhiro; Yatabe, Megumi; Fujiwara, Ken; Hirose, Takuo; Totsune, Kazuhito; Yashiro, Takashi

2013-01-01

Expression of (pro)renin receptor ((P)RR), a specific receptor for renin and prorenin, was studied in rat pituitary gland. In situ hybridization showed that cells expressing (P)RR mRNA were widely distributed in the anterior lobe and intermediate lobe of the pituitary gland. Double-staining using in situ hybridization for (P)RR mRNA and immunohistochemistry for the pituitary hormones showed that (P)RR mRNA was expressed in most of the GH cells and ACTH cells in the anterior lobe. (P)RR mRNA was also expressed in a few prolactin cells and TSH cells, but not in LH cells. The present study has shown for the first time the distribution of (P)RR mRNA expressing cells in the rat pituitary gland. These findings suggest that (P)RR plays physiological roles in the pituitary gland, such as the modulation of the pituitary hormone secretion

A radioligand immunoassay for 1,25-dihydroxyvitamin D3 receptors using monoclonal antibody: detection of a phenotypic receptor variant in vitamin D-dependency rickets (type II) which does not bind hormone

International Nuclear Information System (INIS)

Pike, J.W.; Dokoh, Shigeharu; Liberman, U.A.; Eil, C.; Haussler, M.R.; Marx, S.J.

1984-01-01

Vitamin D-dependency rickets, type II (VDDRII), is a well recognized heritable disorder characterized by peripheral target organ resistance to 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), the hormonally active form of the vitamin. Recently, cultured skin fibroblasts obtained from a number of patients with VDDRII have been utilized to characterize the underlying molecular defects associated with this malady. Recently monoclonal antibodies to the vitamin D receptor have been generated, and a radioligand immunoassay (RLIA) for the detection of this molecule has been developed which is independent of its hormone-binding capacity. This report describes the application of the immunoassay in the detection of receptor-like molecules in fibroblasts derived from patients with VDDRII. The results indicate that the molecule is generally present in all patients, and provides a mechanism for individual responsiveness to pharmacologic treatment with vitamin D 3 metabolites. 8 refs.; 3 figs.; 1 table

Thyroid Hormone Receptor β (TRβ) and Liver X Receptor (LXR) Regulate Carbohydrate-response Element-binding Protein (ChREBP) Expression in a Tissue-selective Manner*

Science.gov (United States)

Gauthier, Karine; Billon, Cyrielle; Bissler, Marie; Beylot, Michel; Lobaccaro, Jean-Marc; Vanacker, Jean-Marc; Samarut, Jacques

2010-01-01

Thyroid hormone (TR) and liver X (LXR) receptors are transcription factors involved in lipogenesis. Both receptors recognize the same consensus DNA-response element in vitro. It was previously shown that their signaling pathways interact in the control of cholesterol elimination in the liver. In the present study, carbohydrate-response element-binding protein (ChREBP), a major transcription factor controlling the activation of glucose-induced lipogenesis in liver, is characterized as a direct target of thyroid hormones (TH) in liver and white adipose tissue (WAT), the two main lipogenic tissues in mice. Using genetic and molecular approaches, ChREBP is shown to be specifically regulated by TRβ but not by TRα in vivo, even in WAT where both TR isoforms are expressed. However, this isotype specificity is not found in vitro. This TRβ specific regulation correlates with the loss of TH-induced lipogenesis in TRβ−/− mice. Fasting/refeeding experiments show that TRβ is not required for the activation of ChREBP expression particularly marked in WAT following refeeding. However, TH can stimulate ChREBP expression in WAT even under fasting conditions, suggesting completely independent pathways. Because ChREBP has been described as an LXR target, the interaction of LXR and TRβ in ChREBP regulation was assayed both in vitro and in vivo. Each receptor recognizes a different response element on the ChREBP promoter, located only 8 bp apart. There is a cross-talk between LXR and TRβ signaling on the ChREBP promoter in liver but not in WAT where LXR does not regulate ChREBP expression. The molecular basis for this cross-talk has been determined in in vitro systems. PMID:20615868

Function of the cytoplasmic tail of human calcitonin receptor-like receptor in complex with receptor activity-modifying protein 2

Energy Technology Data Exchange (ETDEWEB)

Kuwasako, Kenji, E-mail: kuwasako@fc.miyazaki-u.ac.jp [Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692 (Japan); Kitamura, Kazuo; Nagata, Sayaka; Hikosaka, Tomomi [Division of Circulation and Body Fluid Regulation, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692 (Japan); Kato, Johji [Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692 (Japan)

2010-02-12

Receptor activity-modifying protein 2 (RAMP2) enables calcitonin receptor-like receptor (CRLR) to form an adrenomedullin (AM)-specific receptor. Here we investigated the function of the cytoplasmic C-terminal tail (C-tail) of human (h)CRLR by co-transfecting its C-terminal mutants into HEK-293 cells stably expressing hRAMP2. Deleting the C-tail from CRLR disrupted AM-evoked cAMP production or receptor internalization, but did not affect [{sup 125}I]AM binding. We found that CRLR residues 428-439 are required for AM-evoked cAMP production, though deleting this region had little effect on receptor internalization. Moreover, pretreatment with pertussis toxin (100 ng/mL) led to significant increases in AM-induced cAMP production via wild-type CRLR/RAMP2 complexes. This effect was canceled by deleting CRLR residues 454-457, suggesting Gi couples to this region. Flow cytometric analysis revealed that CRLR truncation mutants lacking residues in the Ser/Thr-rich region extending from Ser{sup 449} to Ser{sup 467} were unable to undergo AM-induced receptor internalization and, in contrast to the effect on wild-type CRLR, overexpression of GPCR kinases-2, -3 and -4 failed to promote internalization of CRLR mutants lacking residues 449-467. Thus, the hCRLR C-tail is crucial for AM-evoked cAMP production and internalization of the CRLR/RAMP2, while the receptor internalization is dependent on the aforementioned GPCR kinases, but not Gs coupling.

Growth Hormone Receptor Antagonist Treatment Reduces Exercise Performance in Young Males

DEFF Research Database (Denmark)

Goto, K.; Doessing, S.; Nielsen, R.H.

2009-01-01

between the groups in terms of changes in serum free fatty acids, glycerol, (V) over dotO(2), or relative fat oxidation. Conclusion: GH might be an important determinant of exercise capacity during prolonged exercise, but GHR antagonist did not alter fat metabolism during exercise. (J Clin Endocrinol......Context: The effects of GH on exercise performance remain unclear. Objective: The aim of the study was to examine the effects of GH receptor (GHR) antagonist treatment on exercise performance. Design: Subjects were treated with the GHR antagonist pegvisomant or placebo for 16 d. After the treatment...... period, they exercised to determine exercise performance and hormonal and metabolic responses. Participants: Twenty healthy males participated in the study. Intervention: Subjects were treated with the GHR antagonist (n = 10; 10 mg/d) or placebo (n = 10). After the treatment period, they performed...

Cancer risk and clinicopathological characteristics of thyroid nodules harboring thyroid-stimulating hormone receptor gene mutations.

Science.gov (United States)

Mon, Sann Y; Riedlinger, Gregory; Abbott, Collette E; Seethala, Raja; Ohori, N Paul; Nikiforova, Marina N; Nikiforov, Yuri E; Hodak, Steven P

2018-05-01

Thyroid-stimulating hormone receptor (TSHR) gene mutations play a critical role in thyroid cell proliferation and function. They are found in 20%-82% of hyperfunctioning nodules, hyperfunctioning follicular thyroid cancers (FTC), and papillary thyroid cancers (PTC). The diagnostic importance of TSHR mutation testing in fine needle aspiration (FNA) specimens remains unstudied. To examine the association of TSHR mutations with the functional status and surgical outcomes of thyroid nodules, we evaluated 703 consecutive thyroid FNA samples with indeterminate cytology for TSHR mutations using next-generation sequencing. Testing for EZH1 mutations was performed in selected cases. The molecular diagnostic testing was done as part of standard of care treatment, and did not require informed consent. TSHR mutations were detected in 31 (4.4%) nodules and were located in exons 281-640, with codon 486 being the most common. Allelic frequency ranged from 3% to 45%. Of 16 cases (12 benign, 3 FTC, 1 PTC) with surgical correlation, 15 had solitary TSHR mutations and 1 PTC had comutation with BRAF V600E. Hyperthyroidism was confirmed in all 3 FTC (2 overt, 1 subclinical). Of 5 nodules with solitary TSHR mutations detected at high allelic frequency, 3 (60%) were FTC. Those at low allelic frequency (3%-22%) were benign. EZH1 mutations were detected in 2 of 4 TSHR-mutant malignant nodules and neither of 2 benign nodules. We report that TSHR mutations occur in ∼5% thyroid nodules in a large consecutive series with indeterminate cytology. TSHR mutations may be associated with an increased cancer risk when present at high allelic frequency, even when the nodule is hyperfunctioning. Benign nodules were however most strongly correlated with TSHR mutations at low allelic frequency. © 2018 Wiley Periodicals, Inc.

Tritium-labelled steroids, their preparation and application for the determination and location of steroid tissular hormone receptors

International Nuclear Information System (INIS)

Jouquey, Alain; Raynaud, J.P.

1977-01-01

A product is prepared by the action of tritiated methanol on 11β-hydroxy-estra-4,9-dien-3,17-dione, the action of an aromatisation agent on the (11β)-11-methoxy- 3 H 3 -estra-4,9-dien-3,17-dione formed and the action of an ethynylation agent on the resulting (11β)-3-hydroxy-11-methoxy- 3 H 3 -estra-1,3,5(10)-trien-17-one giving (11β, 17α)-11-methoxy- 3 H 3 -19-norpregna-1,3,5(10)-trien-20-yne-3,17 diol, the free hydroxyl function or functions of this product may be etherified or esterified as the case may be. The tritiated methanol acts in the presence of perchloric acid. The aromatisation agent is palladium hydroxide and the operation is carried out in methanol. The ethynylation agent is acetylene and the reaction takes place in the presence of sodium t-amylate in toluene. This product allows the study and determination of the estrogen specific receptor present in the tissue cells of target organs for the action of estrogens: uterus, vagina, hypophysis, hypothalamus and tumours, of the breast and prostate for example, in both animals and man. Not being fixed by the plasma proteins binding such hormones as testosterone and estradiol in women the product is an ideal indicator of the tissular estrogen receptor with which it forms a complex of strong affinity and great stability, especially since it interacts with the tissular receptors of no other steroid hormone groups (glucocorticoids, androgen or progestogen mineralocorticosteroids) [fr

Investigating the association between polymorphism of follicle-stimulating hormone receptor gene and ovarian response in controlled ovarian hyperstimulation

Directory of Open Access Journals (Sweden)

Mohammad Hasan Sheikhha

2011-01-01

Full Text Available Aim : The aim of the study was to investigate the association between follicle-stimulating hormone receptor (FSHR gene polymorphism at Position 680 and the outcomes of controlled ovarian hyperstimulation for in vitro fertilization and embryo transfer (IVF-ET in infertile women. Materials and Methods : One hundred and eight patients under 35 years of age who underwent IVF-ET procedures were included in this study. The hormonal profile and treatment of all patients were analyzed and FSHR polymorphism was examined by polymerase chain reaction-restriction fragment length polymorphism. Women from all groups were classified based on polymorphisms at Position 680, occupied either by asparagines (Asn or serine (Ser as Asn/Asn, Asn/Ser, and Ser/Ser genotype. Result : Our study showed that all patients in the Asn/Asn group were normal responders and in the Asn/Ser group 64.8% were normal responders and 21.1% and 14.1% were poor and hyper responders respectively. In the Ser/Ser group we did not have normal responders and 46.7% of these patients were poor responders and 53.3% were hyper responders. Conclusion : FSH receptor polymorphism is correlated with response to ovarian stimulation.

Adrenocorticotrophic hormone (ACTH) stimulation of sheep fetal adrenal cortex can occur without increased expression of ACTH receptor (ACTH-R) mRNA

DEFF Research Database (Denmark)

Carter, A M; Petersen, Y M; Towstoless, M

2002-01-01

In the present study, it was hypothesized that the adrenocorticotrophin hormone receptor (ACTH-R) would be up-regulated in the adrenal gland of the sheep fetus following infusion of physiological amounts of ACTH, as shown for adrenal cortical cells in culture. In chronically catheterized sheep...

Structural dataset for the PPARγ V290M mutant

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Ana C. Puhl

2016-06-01

Full Text Available Loss-of-function mutation V290M in the ligand-binding domain of the peroxisome proliferator activated receptor γ (PPARγ is associated with a ligand resistance syndrome (PLRS, characterized by partial lipodystrophy and severe insulin resistance. In this data article we discuss an X-ray diffraction dataset that yielded the structure of PPARγ LBD V290M mutant refined at 2.3 Å resolution, that allowed building of 3D model of the receptor mutant with high confidence and revealed continuous well-defined electron density for the partial agonist diclofenac bound to hydrophobic pocket of the PPARγ. These structural data provide significant insights into molecular basis of PLRS caused by V290M mutation and are correlated with the receptor disability of rosiglitazone binding and increased affinity for corepressors. Furthermore, our structural evidence helps to explain clinical observations which point out to a failure to restore receptor function by the treatment with a full agonist of PPARγ, rosiglitazone.

Adjuvant Trastuzumab in HER2-Positive Early Breast Cancer by Age and Hormone Receptor Status: A Cost-Utility Analysis.

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Leung, William; Kvizhinadze, Giorgi; Nair, Nisha; Blakely, Tony

2016-08-01

-effect data by hormone receptor subtype. Heterogeneity was restricted to age and hormone receptor status; tumour size/grade heterogeneity could be explored in future work. This study highlights how cost-effectiveness can vary greatly by heterogeneity in age and hormone receptor subtype. Resource allocation and licensing of subsidised therapies such as trastuzumab should consider demographic and clinical heterogeneity; there is currently a profound disconnect between how funding decisions are made (largely agnostic to heterogeneity) and the principles of personalised medicine.

Adjuvant Trastuzumab in HER2-Positive Early Breast Cancer by Age and Hormone Receptor Status: A Cost-Utility Analysis.

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William Leung

2016-08-01

treatment-effect data by hormone receptor subtype. Heterogeneity was restricted to age and hormone receptor status; tumour size/grade heterogeneity could be explored in future work.This study highlights how cost-effectiveness can vary greatly by heterogeneity in age and hormone receptor subtype. Resource allocation and licensing of subsidised therapies such as trastuzumab should consider demographic and clinical heterogeneity; there is currently a profound disconnect between how funding decisions are made (largely agnostic to heterogeneity and the principles of personalised medicine.

Application of photoshop-based image analysis to quantification of hormone receptor expression in breast cancer.

Science.gov (United States)

Lehr, H A; Mankoff, D A; Corwin, D; Santeusanio, G; Gown, A M

1997-11-01

The benefit of quantifying estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer is well established. However, in routine breast cancer diagnosis, receptor expression is often quantified in arbitrary scores with high inter- and intraobserver variability. In this study we tested the validity of an image analysis system employing inexpensive, commercially available computer software on a personal computer. In a series of 28 invasive ductal breast cancers, immunohistochemical determinations of ER and PR were performed, along with biochemical analyses on fresh tumor homogenates, by the dextran-coated charcoal technique (DCC) and by enzyme immunoassay (EIA). From each immunohistochemical slide, three representative tumor fields (x20 objective) were captured and digitized with a Macintosh personal computer. Using the tools of Photoshop software, optical density plots of tumor cell nuclei were generated and, after background subtraction, were used as an index of immunostaining intensity. This immunostaining index showed a strong semilogarithmic correlation with biochemical receptor assessments of ER (DCC, r = 0.70, p < 0.001; EIA, r = 0.76, p < 0.001) and even better of PR (DCC, r = 0.86; p < 0.01; EIA, r = 0.80, p < 0.001). A strong linear correlation of ER and PR quantification was also seen between DCC and EIA techniques (ER, r = 0.62, p < 0.001; PR, r = 0.92, p < 0.001). This study demonstrates that a simple, inexpensive, commercially available software program can be accurately applied to the quantification of immunohistochemical hormone receptor studies.

Beyond the HPA-axis: The role of the gonadal steroid hormone receptors in modulating stress-related responses in an animal model of PTSD.

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Fenchel, Daphna; Levkovitz, Yechiel; Vainer, Ella; Kaplan, Zeev; Zohar, Joseph; Cohen, Hagit

2015-06-01

The hypothalamic-pituitary-adrenal (HPA) axis, which plays a major role in the response to stress, and the hypothalamic-pituitary-gonadal (HPG) axis are closely linked with the ability to inhibit the other. Testosterone, a product of the HPG, has many beneficial effects beyond its functions as a sex hormone including anti-anxiety properties. In this study we examined the effect of stress exposure on gonadal hormones, and their efficacy in modulating anxiety-like response in an animal model of PTSD. Male rats were exposed to predator scent stress, followed by analysis of brain expression of androgen receptor (AR) receptor and estrogen receptor α (ERα). The behavioral effects of immediate treatment with testosterone, testosterone receptor antagonist (flutamide) or vehicle were evaluated using the elevated plus-maze, acoustic startle response and trauma-cue response. Levels of circulating corticosterone and testosterone were also measured after treatment. The behavioral effects of delayed testosterone treatment were explored in the same manner. We report that animals whose behavior was extremely disrupted (EBR) selectively displayed significant down-regulation of AR and ERα in the hippocampus. Immediate treatment with flutamide or delayed treatment with testosterone significantly increased prevalence rates of minimal behavioral response (MBR) and decreased prevalence of EBR with favorable behavioral results. Testosterone levels were higher in control un-exposed animals, while corticosterone was higher in control exposed animals. This study suggests that gonadal steroid hormones are involved in the neurobiological response to predator scent stress and thus warrant further study as a potential therapeutic avenue for the treatment of anxiety-related disorders. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Hormone-dependent nuclear export of estradiol receptor and DNA synthesis in breast cancer cells

Science.gov (United States)

Lombardi, Maria; Castoria, Gabriella; Migliaccio, Antimo; Barone, Maria Vittoria; Di Stasio, Rosina; Ciociola, Alessandra; Bottero, Daniela; Yamaguchi, Hiroshi; Appella, Ettore; Auricchio, Ferdinando

2008-01-01

In breast cancer cells, cytoplasmic localization of the estradiol receptor α (ERα) regulates estradiol-dependent S phase entry. We identified a nuclear export sequence (NES) in ERα and show that its export is dependent on both estradiol-mediated phosphatidylinositol-3-kinase (PI3K)/AKT activation and chromosome region maintenance 1 (CRM1). A Tat peptide containing the ERα NES disrupts ERα–CRM1 interaction and prevents nuclear export of ERα- and estradiol-induced DNA synthesis. NES-ERα mutants do not exit the nucleus and inhibit estradiol-induced S phase entry; ERα-dependent transcription is normal. ERα is associated with Forkhead proteins in the nucleus, and estradiol stimulates nuclear exit of both proteins. ERα knockdown or ERα NES mutations prevent ERα and Forkhead nuclear export. A mutant of forkhead in rhabdomyosarcoma (FKHR), which cannot be phosphorylated by estradiol-activated AKT, does not associate with ERα and is trapped in the nucleus, blocking S phase entry. In conclusion, estradiol-induced AKT-dependent phosphorylation of FKHR drives its association with ERα, thereby triggering complex export from the nucleus necessary for initiation of DNA synthesis and S phase entry. PMID:18644889

Towards the emerging crosstalk: ERBB family and steroid hormones.

Science.gov (United States)

D'Uva, Gabriele; Lauriola, Mattia

2016-02-01

Growth factors acting through receptor tyrosine kinases (RTKs) of ERBB family, along with steroid hormones (SH) acting through nuclear receptors (NRs), are critical signalling mediators of cellular processes. Deregulations of ERBB and steroid hormone receptors are responsible for several diseases, including cancer, thus demonstrating the central role played by both systems. This review will summarize and shed light on an emerging crosstalk between these two important receptor families. How this mutual crosstalk is attained, such as through extensive genomic and non-genomic interactions, will be addressed. In light of recent studies, we will describe how steroid hormones are able to fine-tune ERBB feedback loops, thus impacting on cellular output and providing a new key for understanding the complexity of biological processes in physiological or pathological conditions. In our understanding, the interactions between steroid hormones and RTKs deserve further attention. A system biology approach and advanced technologies for the analysis of RTK-SH crosstalk could lead to major advancements in molecular medicine, providing the basis for new routes of pharmacological intervention in several diseases, including cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

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Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

2016-04-01

Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

A regulator of G Protein signaling, RGS3, inhibits gonadotropin-releasing hormone (GnRH-stimulated luteinizing hormone (LH secretion

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Musgrove Lois C

2001-11-01

Full Text Available Abstract Background Luteinizing hormone secreted by the anterior pituitary gland regulates gonadal function. Luteinizing hormone secretion is regulated both by alterations in gonadotrope responsiveness to hypothalamic gonadotropin releasing hormone and by alterations in gonadotropin releasing hormone secretion. The mechanisms that determine gonadotrope responsiveness are unknown but may involve regulators of G protein signaling (RGSs. These proteins act by antagonizing or abbreviating interaction of Gα proteins with effectors such as phospholipase Cβ. Previously, we reported that gonadotropin releasing hormone-stimulated second messenger inositol trisphosphate production was inhibited when RGS3 and gonadotropin releasing hormone receptor cDNAs were co-transfected into the COS cell line. Here, we present evidence for RGS3 inhibition of gonadotropin releasing hormone-induced luteinizing hormone secretion from cultured rat pituitary cells. Results A truncated version of RGS3 (RGS3T = RGS3 314–519 inhibited gonadotropin releasing hormone-stimulated inositol trisphosphate production more potently than did RSG3 in gonadotropin releasing hormone receptor-bearing COS cells. An RSG3/glutathione-S-transferase fusion protein bound more 35S-Gqα than any other member of the G protein family tested. Adenoviral-mediated RGS3 gene transfer in pituitary gonadotropes inhibited gonadotropin releasing hormone-stimulated luteinizing hormone secretion in a dose-related fashion. Adeno-RGS3 also inhibited gonadotropin releasing hormone stimulated 3H-inositol phosphate accumulation, consistent with a molecular site of action at the Gqα protein. Conclusions RGS3 inhibits gonadotropin releasing hormone-stimulated second messenger production (inositol trisphosphate as well as luteinizing hormone secretion from rat pituitary gonadotropes apparently by binding and suppressing the transduction properties of Gqα protein function. A version of RGS3 that is amino

Epigenetics of Estrogen Receptor Signaling: Role in Hormonal Cancer Progression and Therapy

International Nuclear Information System (INIS)

Mann, Monica; Cortez, Valerie; Vadlamudi, Ratna K.

2011-01-01

Estrogen receptor (ERα) signaling plays a key role in hormonal cancer progression. ERα is a ligand-dependent transcription factor that modulates gene transcription via recruitment to the target gene chromatin. Emerging evidence suggests that ERα signaling has the potential to contribute to epigenetic changes. Estrogen stimulation is shown to induce several histone modifications at the ERα target gene promoters including acetylation, phosphorylation and methylation via dynamic interactions with histone modifying enzymes. Deregulation of enzymes involved in the ERα -mediated epigenetic pathway could play a vital role in ERα driven neoplastic processes. Unlike genetic alterations, epigenetic changes are reversible, and hence offer novel therapeutic opportunities to reverse ERα driven epigenetic changes. In this review, we summarize current knowledge on mechanisms by which ERα signaling potentiates epigenetic changes in cancer cells via histone modifications

Epigenetics of Estrogen Receptor Signaling: Role in Hormonal Cancer Progression and Therapy

Energy Technology Data Exchange (ETDEWEB)

Mann, Monica; Cortez, Valerie [Department of Cellular and Structural Biology, UTHSCSA, 7703 Floyd Curl Drive, San Antonio, TX 78229 (United States); Vadlamudi, Ratna K., E-mail: vadlamudi@uthscsa.edu [Department of Obstetrics and Gynecology, UTHSCSA, 7703 Floyd Curl Drive, San Antonio, TX 78229 (United States)

2011-03-29

Estrogen receptor (ERα) signaling plays a key role in hormonal cancer progression. ERα is a ligand-dependent transcription factor that modulates gene transcription via recruitment to the target gene chromatin. Emerging evidence suggests that ERα signaling has the potential to contribute to epigenetic changes. Estrogen stimulation is shown to induce several histone modifications at the ERα target gene promoters including acetylation, phosphorylation and methylation via dynamic interactions with histone modifying enzymes. Deregulation of enzymes involved in the ERα -mediated epigenetic pathway could play a vital role in ERα driven neoplastic processes. Unlike genetic alterations, epigenetic changes are reversible, and hence offer novel therapeutic opportunities to reverse ERα driven epigenetic changes. In this review, we summarize current knowledge on mechanisms by which ERα signaling potentiates epigenetic changes in cancer cells via histone modifications.

IGF-1 and insulin as growth hormones.

Science.gov (United States)

Laron, Zvi

2004-01-01

IGF-1 generated in the liver is the anabolic effector and linear growth promoting hormone of the pituitary growth hormone (GH). This is evidenced by dwarfism in states of congenital IGF-1 deficiency, Igf1 gene mutation/deletions or knockouts, and in Laron syndrome (LS), due to GH receptor gene mutations/deletions or IGF-1 receptor blocking. In a positive way, daily IGF-1 administration to stunted patients with LS or hGH gene deletion accelerates linear growth velocity. IGF-1 acts on the proliferative cells of the epiphyseal cartilage. IGF-1 also induces organ and tissue growth; its absence causing organomicria. Insulin shares a common ancestry with IGF-1 and with 45% amino acid homology, as well as very close relationships in the structure of its receptors and post-receptor cascade, also acts as a growth hormone. It has protein anabolic activity and stimulates IGF-1 synthesis. Pancreas agenesis causes short babies, and obese children with hyperinsulinism, with or without pituitary GH, have an accelerated growth rate and skeletal maturation; so do babies with macrosomia. Whether the insulin growth effect is direct, or mediated by IGF-1 or leptin is controversial.

Using paleogenomics to study the evolution of gene families: origin and duplication history of the relaxin family hormones and their receptors.

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Sergey Yegorov

Full Text Available Recent progress in the analysis of whole genome sequencing data has resulted in the emergence of paleogenomics, a field devoted to the reconstruction of ancestral genomes. Ancestral karyotype reconstructions have been used primarily to illustrate the dynamic nature of genome evolution. In this paper, we demonstrate how they can also be used to study individual gene families by examining the evolutionary history of relaxin hormones (RLN/INSL and relaxin family peptide receptors (RXFP. Relaxin family hormones are members of the insulin superfamily, and are implicated in the regulation of a variety of primarily reproductive and neuroendocrine processes. Their receptors are G-protein coupled receptors (GPCR's and include members of two distinct evolutionary groups, an unusual characteristic. Although several studies have tried to elucidate the origins of the relaxin peptide family, the evolutionary origin of their receptors and the mechanisms driving the diversification of the RLN/INSL-RXFP signaling systems in non-placental vertebrates has remained elusive. Here we show that the numerous vertebrate RLN/INSL and RXFP genes are products of an ancestral receptor-ligand system that originally consisted of three genes, two of which apparently trace their origins to invertebrates. Subsequently, diversification of the system was driven primarily by whole genome duplications (WGD, 2R and 3R followed by almost complete retention of the ligand duplicates in most vertebrates but massive loss of receptor genes in tetrapods. Interestingly, the majority of 3R duplicates retained in teleosts are potentially involved in neuroendocrine regulation. Furthermore, we infer that the ancestral AncRxfp3/4 receptor may have been syntenically linked to the AncRln-like ligand in the pre-2R genome, and show that syntenic linkages among ligands and receptors have changed dynamically in different lineages. This study ultimately shows the broad utility, with some caveats, of

Skeletal muscle expression of p43, a truncated thyroid hormone receptor α, affects lipid composition and metabolism.

Science.gov (United States)

Casas, François; Fouret, Gilles; Lecomte, Jérome; Cortade, Fabienne; Pessemesse, Laurence; Blanchet, Emilie; Wrutniak-Cabello, Chantal; Coudray, Charles; Feillet-Coudray, Christine

2018-02-01

Thyroid hormone is a major regulator of metabolism and mitochondrial function. Thyroid hormone also affects reactions in almost all pathways of lipids metabolism and as such is considered as the main hormonal regulator of lipid biogenesis. The aim of this study was to explore the possible involvement of p43, a 43 Kda truncated form of the nuclear thyroid hormone receptor TRα1 which stimulates mitochondrial activity. Therefore, using mouse models overexpressing p43 in skeletal muscle (p43-Tg) or lacking p43 (p43-/-), we have investigated the lipid composition in quadriceps muscle and in mitochondria. Here, we reported in the quadriceps muscle of p43-/- mice, a fall in triglycerides, an inhibition of monounsaturated fatty acids (MUFA) synthesis, an increase in elongase index and an decrease in desaturase index. However, in mitochondria from p43-/- mice, fatty acid profile was barely modified. In the quadriceps muscle of p43-Tg mice, MUFA content was decreased whereas the unsaturation index was increased. In addition, in quadriceps mitochondria of p43-Tg mice, we found an increase of linoleic acid level and unsaturation index. Last, we showed that cardiolipin content, a key phospholipid for mitochondrial function, remained unchanged both in quadriceps muscle and in its mitochondria whatever the mice genotype. In conclusion, this study shows that muscle lipid content and fatty acid profile are strongly affected in skeletal muscle by p43 levels. We also demonstrate that regulation of cardiolipin biosynthesis by the thyroid hormone does not imply p43.

PAC1- and VPAC2 receptors in light regulated behavior and physiology: Studies in single and double mutant mice.

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Jens Hannibal

Full Text Available The two sister peptides, pituitary adenylate cyclase activating polypeptide (PACAP and vasoactive intestinal polypeptide (VIP and their receptors, the PAC1 -and the VPAC2 receptors, are involved in regulation of the circadian timing system. PACAP as a neurotransmitter in the retinohypothalamic tract (RHT and VIP as a neurotransmitter, involved in synchronization of SCN neurons. Behavior and physiology in VPAC2 deficient mice are strongly regulated by light most likely as a result of masking. Consequently, we used VPAC2 and PAC1/VPAC2 double mutant mice in comparison with PAC1 receptor deficient mice to further elucidate the role of PACAP in the light mediated regulation of behavior and physiology of the circadian system. We compared circadian rhythms in mice equipped with running wheels or implanted radio-transmitter measuring core body temperature kept in a full photoperiod ((FPP(12:12 h light dark-cycles (LD and skeleton photo periods (SPP at high and low light intensity. Furthermore, we examined the expression of PAC1- and VPAC2 receptors in the SCN of the different genotypes in combination with visualization of PACAP and VIP and determined whether compensatory changes in peptide and/or receptor expression in the reciprocal knockouts (KO (PAC1 and VPAC2 had occurred. Our data demonstrate that in although being closely related at both ligand and receptor structure/sequence, PACAP/PAC1 receptor signaling are independent of VIP/VPAC2 receptor signaling and vice versa. Furthermore, lack of either of the receptors does not result in compensatory changes at neither the physiological or anatomical level. PACAP/PAC1 signaling is important for light regulated behavior, VIP/VPAC2signaling for stable clock function and both signaling pathways may play a role in shaping diurnality versus nocturnality.

NRSAS: Nuclear Receptor Structure Analysis Servers.

NARCIS (Netherlands)

Bettler, E.J.M.; Krause, R.; Horn, F.; Vriend, G.

2003-01-01

We present a coherent series of servers that can perform a large number of structure analyses on nuclear hormone receptors. These servers are part of the NucleaRDB project, which provides a powerful information system for nuclear hormone receptors. The computations performed by the servers include

ERK, Akt, and STAT5 are differentially activated by the two growth hormone receptors subtypes of a teleost fish (Oncorhynchus mykiss

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Jeffrey eKittilson

2011-09-01

Full Text Available Previously, we found that the teleost fish, rainbow trout, possesses two growth hormone receptor (GHR subtypes that display distinct ligand binding and agonist-induced regulation features. In this study, we used Chinese hamster ovary-K1 cells stably transfected individually with the two trout GHR subtypes, GHR1 and GHR2, to elucidate receptor-effector pathway linkages. Growth hormone (GH stimulated rapid (5-10 min phosphorylation of ERK, Akt, JAk2, and STAT5 in both GHR1- and GHR2-expressing cells; however; STAT5 was activated to a greater extent through GHR1 than through GHR2, whereas ERK and Akt were activated to a greater through GHR2 than through GHR1. Although blockade of the ERK pathway had no effect on the activation of Akt, inhibition of PI3k-Akt partially prevented activation of ERK, suggesting cross-talk between the ERK and PI3K-Akt pathways. JAK2 inhibition completely blocked activation of ERK, Akt, and STAT5, suggesting that all of these pathways link to GHR1 and GHR2 via JAK2. These findings establish important receptor-effector pathway linkages and suggest that the GHR subtypes of teleost fish may be functionally distinct.

A selective androgen receptor modulator for hormonal male contraception.

Science.gov (United States)

Chen, Jiyun; Hwang, Dong Jin; Bohl, Casey E; Miller, Duane D; Dalton, James T

2005-02-01

The recent discovery of nonsteroidal selective androgen receptor modulators (SARMs) provides a promising alternative for testosterone replacement therapies, including hormonal male contraception. The identification of an orally bioavailable SARM with the ability to mimic the central and peripheral androgenic and anabolic effects of testosterone would represent an important step toward the "male pill". We characterized the in vitro and in vivo pharmacologic activity of (S)-3-(4-chloro-3-fluorophenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethylphenyl)propionamide (C-6), a novel SARM developed in our laboratories. C-6 was identified as an androgen receptor (AR) agonist with high AR binding affinity (K(i) = 4.9 nM). C-6 showed tissue-selective pharmacologic activity with higher anabolic activity than androgenic activity in male rats. The doses required to maintain the weight of the prostate, seminal vesicles, and levator ani muscle to half the size of the maximum effects (i.e., ED(50)) were 0.78 +/- 0.06, 0.88 +/- 0.1, and 0.17 +/- 0.04 mg/day, respectively. As opposed to other SARMs, gonadotropin levels in C-6-treated groups were significantly lower than control values. C-6 also significantly decreased serum testosterone concentration in intact rats after 2 weeks of treatment. Marked suppression of spermatogenesis was observed after 10 weeks of treatment with C-6 in intact male rats. Pharmacokinetic studies of C-6 in male rats revealed that C-6 was well absorbed after oral administration (bioavailability 76%), with a long (6.3 h) half-life at a dose of 10 mg/kg. These studies show that C-6 mimicked the in vivo pharmacologic and endocrine effects of testosterone while maintaining the oral bioavailability and tissue-selective actions of nonsteroidal SARMs.

Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

Energy Technology Data Exchange (ETDEWEB)

Jett, J. [Lawrence Livermore National Lab., CA (United States)

1994-12-01

While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors

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Kelly J Culhane

2015-11-01

Full Text Available Although family B G protein-coupled receptors (GPCRs contain only 15 members, they play key roles in transmembrane signal transduction of hormones. Family B GPCRs are drug targets for developing therapeutics for diseases ranging from metabolic to neurological disorders. Despite their importance, the molecular mechanism of activation of family B GPCRs remains largely unexplored due to the challenges in expression and purification of functional receptors to the quantity for biophysical characterization. Currently, there is no crystal structure available of a full-length family B GPCR. However, structures of key domains, including the extracellular ligand binding regions and seven-helical transmembrane regions, have been solved by X-ray crystallography and NMR, providing insights into the mechanisms of ligand recognition and selectivity, and helical arrangements within the cell membrane. Moreover, biophysical and biochemical methods have been used to explore functions, key residues for signaling, and the kinetics and dynamics of signaling processes. This review summarizes the current knowledge of the signal transduction mechanism of family B GPCRs at the molecular level and comments on the challenges and outlook for mechanistic studies of family B GPCRs.

125I-luteinizing hormone (LH) binding to soluble receptors from the primate (Macaca mulatta) corpus luteum: effects of ethanol exposure

International Nuclear Information System (INIS)

Danforth, D.R.; Stouffer, R.L.

1988-01-01

In the current study, we compared the effects of ethanol on gonadotropin receptors solubilized from macaque luteal membranes to those on receptors associated with the lipid bilayer. Treatment with 1% Triton X-100 for 30 min at 4C, followed by precipitation with polyethylene glycol, resulted in recovery of 50% more binding sites for 125 I-human luteinizing hormone (hLH) than were available in particulate preparations. However, the soluble receptors displayed a 3-fold lower affinity for 125 I-hLH. Conditions which enhanced LH binding to particulates, i.e., 1-8% ethanol at 25C, decreased specific 125 I-hLH binding to soluble receptors. Steady-state LH binding to soluble receptors during incubation at 4C was half of that observed at 25C. The presence of 8% ethanol at 4C restored LH binding to levels observed in the absence of ethanol at 25C. Thus, LH binding sites in the primate corpus luteum can be effectively solubilized with Triton X-100. The different binding characteristics of particulate and soluble receptors, including the response to ethanol exposure, suggest that the lipid environment in the luteal membrane modulates the availability and affinity of gonadotropin receptors

Thyroid hormone regulation of epidermal growth factor receptor levels in mouse mammary glands

International Nuclear Information System (INIS)

Vonderhaar, B.K.; Tang, E.; Lyster, R.R.; Nascimento, M.C.

1986-01-01

The specific binding of iodinated epidermal growth factor ([ 125 I]iodo-EGF) to membranes prepared from the mammary glands and spontaneous breast tumors of euthyroid and hypothyroid mice was measured in order to determine whether thyroid hormones regulate the EGF receptor levels in vivo. Membranes from hypothyroid mammary glands of mice at various developmental ages bound 50-65% less EGF than those of age-matched euthyroid controls. Treatment of hypothyroid mice with L-T4 before killing restored binding to the euthyroid control level. Spontaneous breast tumors arising in hypothyroid mice also bound 30-40% less EGF than tumors from euthyroid animals even after in vitro desaturation of the membranes of endogenous growth factors with 3 M MgCl2 treatment. The decrease in binding in hypothyroid membranes was due to a decrease in the number of binding sites, not to a change in affinity of the growth factor for its receptor, as determined by Scatchard analysis of the binding data. Both euthyroid and hypothyroid membranes bound EGF primarily to a single class of high affinity sites [dissociation constant (Kd) = 0.7-1.8 nM]. Euthyroid membranes bound 28.4 +/- (SE) 0.6 fmol/mg protein, whereas hypothyroid membranes bound 15.5 +/- 1.0 fmol/mg protein. These data indicate that EGF receptor levels in normal mammary glands and spontaneous breast tumors in mice are subject to regulation by thyroid status

Growth Hormone Receptor Mutations Related to Individual Dwarfism

Science.gov (United States)

Li, Charles; Zhang, Xiquan

2018-01-01

Growth hormone (GH) promotes body growth by binding with two GH receptors (GHRs) at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin-like growth factor (IGF) synthesis. However, process dysfunctions in the GH–GHR–IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH–GHR–IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature), including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development. PMID:29748515

Growth Hormone Receptor Mutations Related to Individual Dwarfism

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Shudai Lin

2018-05-01

Full Text Available Growth hormone (GH promotes body growth by binding with two GH receptors (GHRs at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin‐like growth factor (IGF synthesis. However, process dysfunctions in the GH–GHR–IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH–GHR–IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature, including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development.