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Sample records for adipokinetic hormone receptors

  1. Characterization of the adipokinetic hormone receptor of the anautogenous flesh fly, Sarcophaga crassipalpis.

    PubMed

    Bil, Magdalena; Timmermans, Iris; Verlinden, Heleen; Huybrechts, Roger

    2016-06-01

    Adipokinetic hormone (AKH) is an insect neuropeptide mainly involved in fat body energy mobilization. In flies (Phormia regina, Sarcophaga crassipalpis), bugs (Pyrrhocoris apterus) and cockroaches (Periplaneta americana) AKH was also demonstrated to be involved in the regulation of digestion. This makes AKH an important peptide for anautogenous female flies that need to feed on a supplementary protein meal to initiate vitellogenesis, the large scale synthesis of yolk proteins and their uptake by the developing oocytes. Flesh fly AKH, originally identified as Phormia terraenovae hypertrehalosemic hormone (PhoteHrTH), functions through activation of the AKH receptor (AKHR). This is a G protein-coupled receptor that is the orthologue of the human gonadotropin-releasing hormone receptor. Pharmacological characterization indicated that the receptor can be activated by two related dipteran AKH ligands with an EC50 value in the low nanomolar range, whereas micromolar concentrations of the Tribolium castaneum AKH were needed. Consistent with the energy mobilizing function of AKH, the receptor transcript levels were most abundant in the fat body tissue. Nonetheless, Sarcophaga crassipalpis AKHR transcript levels were also high in the brain, the foregut and the hindgut. Interestingly, the receptor transcript numbers were reduced in almost all measured tissues after protein feeding. These changes may enforce the use of ingested energy carrying molecules prior to stored energy mobilization.

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

    PubMed Central

    Li, Shizhong; Hauser, Frank; Skadborg, Signe K.; Nielsen, Stine V.; Kirketerp-Møller, Nikolaj; Grimmelikhuijzen, Cornelis J. P.

    2016-01-01

    Most multicellular animals belong to two evolutionary lineages, the Proto– and Deuterostomia, which diverged 640–760 million years (MYR) ago. Neuropeptide signaling is abundant in animals belonging to both lineages, but it is often unclear whether there exist evolutionary relationships between 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, and AKH/corazonin-related peptide (ACP) are the ligands in Protostomia. AKH is a well-studied insect neuropeptide that mobilizes lipids and carbohydrates from the insect fat body during flight. In our present paper, we show that AKH is not only widespread in insects, but also in other Ecdysozoa and in Lophotrochozoa. Furthermore, we have cloned and deorphanized two G protein-coupled receptors (GPCRs) from the oyster Crassostrea gigas (Mollusca) that are activated by low nanomolar concentrations of oyster AKH (pQVSFSTNWGSamide). Our discovery of functional AKH receptors in molluscs is especially significant, because it traces the emergence of AKH signaling back to about 550 MYR ago and brings us closer to a more complete understanding of the evolutionary origins of the GnRH receptor superfamily. PMID:27628442

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

    PubMed

    Li, Shizhong; Hauser, Frank; Skadborg, Signe K; Nielsen, Stine V; Kirketerp-Møller, Nikolaj; Grimmelikhuijzen, Cornelis J P

    2016-01-01

    Most multicellular animals belong to two evolutionary lineages, the Proto- and Deuterostomia, which diverged 640-760 million years (MYR) ago. Neuropeptide signaling is abundant in animals belonging to both lineages, but it is often unclear whether there exist evolutionary relationships between 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, and AKH/corazonin-related peptide (ACP) are the ligands in Protostomia. AKH is a well-studied insect neuropeptide that mobilizes lipids and carbohydrates from the insect fat body during flight. In our present paper, we show that AKH is not only widespread in insects, but also in other Ecdysozoa and in Lophotrochozoa. Furthermore, we have cloned and deorphanized two G protein-coupled receptors (GPCRs) from the oyster Crassostrea gigas (Mollusca) that are activated by low nanomolar concentrations of oyster AKH (pQVSFSTNWGSamide). Our discovery of functional AKH receptors in molluscs is especially significant, because it traces the emergence of AKH signaling back to about 550 MYR ago and brings us closer to a more complete understanding of the evolutionary origins of the GnRH receptor superfamily. PMID:27628442

  4. New insights into adipokinetic hormone signaling.

    PubMed

    Vroemen, S F; Van der Horst, D J; Van Marrewijk, W J

    1998-06-25

    Flight activity of insects comprises one of the most intense biochemical processes known in nature, and therefore provides an attractive model system to study the hormonal regulation of metabolism during physical exercise. In long-distance flying insects, such as the migratory locust, both carbohydrate and lipid reserves are utilized as fuels for sustained flight activity. The mobilization of these energy stores in Locusta migratoria is mediated by three structurally related adipokinetic hormones (AKHs), which are all capable of stimulating the release of both carbohydrates and lipids from the fat body. To exert their effects intracellularly, these hormones induce a variety of signal transduction events, involving the activation of AKH receptors, GTP-binding proteins, cyclic AMP, inositol phosphates and Ca2+. In this review, we discuss recent advances in the research into AKH signaling. This not only includes the effects of the three AKHs on each of the signaling molecules, but also crosstalk between signaling cascades and the degradation rates of the hormones in the hemolymph. On the basis of the observed differences between the three AKHs, we have tried to construct a physiological model for their action in locusts, in order to answer a fundamental question in endocrinology: why do several structurally and functionally related peptide hormones co-exist in locusts (and animals in general), when apparently one single hormone would be sufficient to exert the desired effects? We suggest that the success of the migratory locust in performing long-distance flights is in part based on this neuropeptide multiplicity, with AKH-I being the strongest lipid-mobilizing hormone, AKH-II the most powerful carbohydrate mobilizer and AKH-III, a modulatory entity that predominantly serves to provide the animal with energy at rest. PMID:9723879

  5. Identification of distinct c-terminal domains of the Bombyx adipokinetic hormone receptor that are essential for receptor export, phosphorylation and internalization.

    PubMed

    Huang, Haishan; Deng, Xiaoyan; He, Xiaobai; Yang, Wen; Li, Guo; Shi, Ying; Shi, Liangen; Mei, Lijuan; Gao, Jimin; Zhou, Naiming

    2011-09-01

    Neuropeptides of the adipokinetic hormone (AKH) family play important roles in insect hemolymph sugar homeostasis, larval lipolysis and storage-fat mobilization. Our previous studies have shown that the adipokinetic hormone receptor (AKHR), a Gs-coupled receptor, induces intracellular cAMP accumulation, calcium mobilization and ERK1/2 phosphorylation upon agonist stimulation. However, the underlying molecular mechanisms that regulate the internalization and desensitization of AKHR remain largely unknown. In the current study we made a construct to express AKHR fused with enhanced green fluorescent protein (EGFP) at its C-terminal end to further characterize AKHR internalization. In stable AKHR-EGFP-expressing HEK-293 cells, AKHR-EGFP was mainly localized at the plasma membrane and was rapidly internalized in a dose- and time-dependent manner via the clathrin-coated pit pathway upon agonist stimulation, and internalized receptors were slowly recovered to the cell surface after the removal of AKH peptides. The results derived from RNA interference and arrestin translocation demonstrated that G protein-coupled receptor kinase 2 and 5 (GRK2/5) and β-arrestin2 were involved in receptor phosphorylation and internalization. Furthermore, experiments using deletion and site-directed mutagenesis strategies identified the three residues (Thr356, Ser359 and Thr362) responsible for GRK-mediated phosphorylation and internalization and the C-terminal domain from residue-322 to residue-342 responsible for receptor export from ER. This is the first detailed investigation of the internalization and trafficking of insect G protein-coupled receptors.

  6. Locust adipokinetic hormones mobilize diacylglycerols selectively.

    PubMed

    Tomcala, Ales; Bártů, Iva; Simek, Petr; Kodrík, Dalibor

    2010-05-01

    The diacylglycerols (DG) molecular species and their fatty acid (FA) composition were investigated by electrospray mass spectrometry (ESI-MS) and by gas chromatography with flame ionisation detection (GC-FID) in haemolymph of Locusta migratoria after application of adipokinetic hormones Locmi-AKH-I, -II and -III. The analyses showed (1) a heterogeneous distribution of individual DGs in haemolymph after the hormone application. The results revealed that mobilization of the DGs is molecular species-specific with the highest proportion of 34:1 DG (16:0/18:1 - mw 594Da) for all Locmi-AKHs bearing palmitic acid (C16:0) and oleic acid (C18:1) residues, and forming about 20% of the total mobilized DG content. (2) Analysis of fat body triacylglycerols revealed that all Locmi-AKHs mobilize the DGs selectively with the preference of those possessing the C18 and C16 FAs. The fat body FAs with carbon chain longer than 18 did not participate in the mobilization. (3) A distribution of FAs in the DG structures obtained by LC/ESI-MS, and FA analysis by GC-FID after transmethylation indicated a certain degree of Locmi-AKH selectivity toward the mobilized DGs and hence the FAs. The Locmi-AKH-I significantly prefers mobilization of DGs containing unsaturated FAs, while Locmi-AKH-II and -III prefer mobilization of saturated FAs. PMID:20139028

  7. Energy Homeostasis Control in Drosophila Adipokinetic Hormone Mutants.

    PubMed

    Gáliková, Martina; Diesner, Max; Klepsatel, Peter; Hehlert, Philip; Xu, Yanjun; Bickmeyer, Iris; Predel, Reinhard; Kühnlein, Ronald P

    2015-10-01

    Maintenance of biological functions under negative energy balance depends on mobilization of storage lipids and carbohydrates in animals. In mammals, glucagon and glucocorticoid signaling mobilizes energy reserves, whereas adipokinetic hormones (AKHs) play a homologous role in insects. Numerous studies based on AKH injections and correlative studies in a broad range of insect species established the view that AKH acts as master regulator of energy mobilization during development, reproduction, and stress. In contrast to AKH, the second peptide, which is processed from the Akh encoded prohormone [termed "adipokinetic hormone precursor-related peptide" (APRP)] is functionally orphan. APRP is discussed as ecdysiotropic hormone or as scaffold peptide during AKH prohormone processing. However, as in the case of AKH, final evidence for APRP functions requires genetic mutant analysis. Here we employed CRISPR/Cas9-mediated genome engineering to create AKH and AKH plus APRP-specific mutants in the model insect Drosophila melanogaster. Lack of APRP did not affect any of the tested steroid-dependent processes. Similarly, Drosophila AKH signaling is dispensable for ontogenesis, locomotion, oogenesis, and homeostasis of lipid or carbohydrate storage until up to the end of metamorphosis. During adulthood, however, AKH regulates body fat content and the hemolymph sugar level as well as nutritional and oxidative stress responses. Finally, we provide evidence for a negative autoregulatory loop in Akh gene regulation. PMID:26275422

  8. Energy Homeostasis Control in Drosophila Adipokinetic Hormone Mutants

    PubMed Central

    Gáliková, Martina; Diesner, Max; Klepsatel, Peter; Hehlert, Philip; Xu, Yanjun; Bickmeyer, Iris; Predel, Reinhard; Kühnlein, Ronald P.

    2015-01-01

    Maintenance of biological functions under negative energy balance depends on mobilization of storage lipids and carbohydrates in animals. In mammals, glucagon and glucocorticoid signaling mobilizes energy reserves, whereas adipokinetic hormones (AKHs) play a homologous role in insects. Numerous studies based on AKH injections and correlative studies in a broad range of insect species established the view that AKH acts as master regulator of energy mobilization during development, reproduction, and stress. In contrast to AKH, the second peptide, which is processed from the Akh encoded prohormone [termed “adipokinetic hormone precursor-related peptide” (APRP)] is functionally orphan. APRP is discussed as ecdysiotropic hormone or as scaffold peptide during AKH prohormone processing. However, as in the case of AKH, final evidence for APRP functions requires genetic mutant analysis. Here we employed CRISPR/Cas9-mediated genome engineering to create AKH and AKH plus APRP-specific mutants in the model insect Drosophila melanogaster. Lack of APRP did not affect any of the tested steroid-dependent processes. Similarly, Drosophila AKH signaling is dispensable for ontogenesis, locomotion, oogenesis, and homeostasis of lipid or carbohydrate storage until up to the end of metamorphosis. During adulthood, however, AKH regulates body fat content and the hemolymph sugar level as well as nutritional and oxidative stress responses. Finally, we provide evidence for a negative autoregulatory loop in Akh gene regulation. PMID:26275422

  9. The adipokinetic hormone family in Chrysomeloidea: structural and functional considerations *

    PubMed Central

    Gäde, Gerd; Marco, Heather G.

    2011-01-01

    Abstract The presented work is a hybrid of an overview and an original research paper on peptides belonging to the adipokinetic hormone (AKH) family that are present in the corpora cardiaca of Chrysomeloidea. First, we introduce the AKH/red pigment-concentrating hormone (RPCH) peptide family. Second, we collate the available primary sequence data on AKH peptides in Cerambycidae and Chrysomelidae, and we present new sequencing data (from previously unstudied species) obtained by liquid-chromatography coupled with ion trap electrospray ionisation mass spectrometry. Our expanded data set encompasses the primary structure of AKHs from seven species of Cerambycidae and three species of Chrysomelidae. All of these species synthesise the octapeptide code-named Peram-CAH-I (pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp amide). Whereas this is the sole AKH peptide in Cerambycidae, Chrysomelidae demonstrate a probable event of AKH gene duplication, thereby giving rise to an additional AKH. This second AKH peptide may be either Emppe-AKH (pGlu-Val-Asn-Phe-Thr-Pro-Asn-Trp amide) or Peram-CAH-II (pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp amide). The peptide distribution and structural data suggest that both families are closely related and that Peram-CAH-I is the ancestral peptide. We hypothesise on the molecular evolution of Emppe-AKH and Peram-CAH-II from the ancestral peptide due to nonsynonymous missense single nucleotide polymorphism in the nucleotide coding sequence of prepro-AKH. Finally, we review the biological significance of the AKH peptides as hyperprolinaemic hormones in Chrysomeloidea, i.e. they cause an increase in the circulating concentration of proline. The mobilisation of proline has been demonstrated during flight in both cerambycid and chrysomelid beetles. PMID:22303105

  10. Structure-activity relationship of adipokinetic hormone analogs in the striped hawk moth, Hippotion eson.

    PubMed

    Marco, Heather G; Gäde, Gerd

    2015-06-01

    We showed previously that the sphingid moth Hippotion eson synthesizes the highest number of adipokinetic hormones (AKHs) ever recorded, viz. five, in its corpus cardiacum: two octa-, two nona- and one decapeptide. Further, the endogenous decapeptide (Manse-AKH-II) and the other four AKHs are all active in lipid mobilization, whereas a non-lepidopteran decapeptide (Lacsp-AKH, five amino acid substitutions compared with Manse-AKH-II), was inactive in H. eson. We tested the decapeptide, Lacol-AKH, from a noctuid moth for the first time in a bioassay and it shows a maximal AKH effect in H. eson. Lacol-AKH differs from Manse-AKH-II in three places and from Lacsp-AKH in four places. We, thus, used Lacol-AKH as a lead peptide on which a series of AKH analogs are based to represent: (a) single amino acid replacements (according to the substitutions in Lacsp-AKH), (b) shorter chain lengths, (c) modified termini, and (d) a replacement of Trp in position 8. These analogs, as well as a few naturally occurring AKHs from other lepidopterans were tested in in vivo adipokinetic assays to gain insight into the ligand-receptor interaction in H. eson. Our results show that the second and third amino acids are important for biological activity in the sphingid moth. Analogs with an N-[acetylated]Glu(1) (instead of a pyroGlu), or a free C-terminus, or Ala(8) were not active in the bioassays, while shortened Lacol-AKH analogs and the undecapeptide, non-amidated Vanca-AKH showed very reduced activity (below 25%). This information is important for the consideration of peptide mimetics to combat specific lepidopteran pest insects.

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

    PubMed

    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. PMID:27374982

  12. Trehalose inhibits the release of adipokinetic hormones from the corpus cardiacum in the African migratory locust, Locusta migratoria, at the level of the adipokinetic cells.

    PubMed

    Passier, P C; Vullings, H G; Diederen, J H; Van der Horst, D J

    1997-05-01

    The effect of trehalose at various concentrations on the release of adipokinetic hormones (AKHs) from the adipokinetic cells in the glandular part of the corpus cardiacum of Locusta migratoria was studied in vitro. Pools of five corpora cardiaca or pools of five glandular parts of corpora cardiaca were incubated in a medium containing different concentrations of trehalose in the absence or presence of AKH-release-inducing agents. It was demonstrated that trehalose inhibits spontaneous release of AKH I in a dose-dependent manner. At a concentration of 80 mM, which is the concentration found in the hemolymph at rest, trehalose significantly decreased the release of AKH I induced by 100 microM locustatachykinin 1, 10 microM 3-isobutyl-1-methylxanthine (IBMX) or high potassium concentrations. The specificity of the effect of trehalose was studied by incubating pools of corpora cardiaca with the non-hydrolyzable disaccharide sucrose or with glucose, the degradation product of trehalose, both in the presence and absence of 10 microM IBMX. Sucrose had no effect at all on the release of AKH I, whereas glucose strongly inhibited its release. The results point to the inhibitory effect of trehalose on the release of AKH I being exerted, at least partly, at the level of the adipokinetic cells, possibly after its conversion into glucose. The data presented in this study support the hypothesis that in vivo the relatively high concentration of trehalose (80 mM) at rest strongly inhibits the release of AKHs. At the onset of flight, the demand for energy substrates exceeds the amount of trehalose that can be mobilized from the fat body and consequently the trehalose concentration in the hemolymph decreases. This relieves the inhibitory effect of trehalose on the release of AKHs, which in turn mobilize lipids from the fat body. PMID:9166120

  13. Localization and Functional Characterization of a Novel Adipokinetic Hormone in the Mollusk, Aplysia californica

    PubMed Central

    Johnson, Joshua I.; Kavanaugh, Scott I.; Nguyen, Cindy; Tsai, Pei-San

    2014-01-01

    Increasing evidence suggests that gonadotropin-releasing hormone (GnRH), corazonin, adipokinetic hormone (AKH), and red pigment-concentrating hormone all share common ancestry to form a GnRH superfamily. Despite the wide presence of these peptides in protostomes, their biological effects remain poorly characterized in many taxa. This study had three goals. First, we cloned the full-length sequence of a novel AKH, termed Aplysia-AKH, and examined its distribution in an opisthobranch mollusk, Aplysia californica. Second, we investigated in vivo biological effects of Aplysia-AKH. Lastly, we compared the effects of Aplysia-AKH to a related A. californica peptide, Aplysia-GnRH. Results suggest that Aplysia-AKH mRNA and peptide are localized exclusively in central tissues, with abdominal, cerebral, and pleural ganglia being the primary sites of Aplysia-AKH production. However, Aplysia-AKH-positive fibers were found in all central ganglia, suggesting diverse neuromodulatory roles. Injections of A. californica with Aplysia-AKH significantly inhibited feeding, reduced body mass, increased excretion of feces, and reduced gonadal mass and oocyte diameter. The in vivo effects of Aplysia-AKH differed substantially from Aplysia-GnRH. Overall, the distribution and biological effects of Aplysia-AKH suggest it has diverged functionally from Aplysia-GnRH over the course of evolution. Further, that both Aplysia-AKH and Aplysia-GnRH failed to activate reproduction suggest the critical role of GnRH as a reproductive activator may be a phenomenon unique to vertebrates. PMID:25162698

  14. Unique translational modification of an invertebrate neuropeptide: a phosphorylated member of the adipokinetic hormone peptide family

    PubMed Central

    2005-01-01

    Separation of an extract of corpora cardiaca from the protea beetle, Trichostetha fascicularis, by single-step RP (reverse-phase)-HPLC and monitoring of tryptophan fluorescence resulted in two distinctive peaks, the material of which mobilized proline and carbohydrates in a bioassay performed using the beetle. Material from one of these peaks was; however, inactive in the classical bioassays of locusts and cockroaches that are used for detecting peptides belonging to the AKH (adipokinetic hormone) family. After enzymatically deblocking the N-terminal pyroglutamic acid (pGlu) residue in the peptide material and sequencing by Edman degradation, a partial sequence was obtained: (pGlu)-Ile-Asn-Met-Thr-Xaa-Gly-Trp. The complete sequence was deduced from ESI-MSn (electrospray ionization multi-stage-MS); position six was identified as a phosphothreonine residue and the C-terminus is amidated. The peptide, code-named Trifa-CC, was chemically synthesized and used in confirmatory experiments to show that the primary structure had been correctly assigned. To our knowledge, this is the first report of a phosphorylated invertebrate neuropeptide. Synthetic Trifa-CC co-elutes with the natural peptide, found in the gland of the protea beetle, after RP-HPLC. Moreover, the natural peptide can be dephosphorylated by alkaline phosphatase and the product of that reaction has the same retention time as a synthetic nonphosphorylated octapeptide which has the same sequence as Trifa-CC. Finally, synthetic Trifa-CC has hypertrehalosaemic and hyperprolinaemic biological activity in the protea beetle, but even high concentrations of synthetic Trifa-CC are inactive in locusts and cockroaches. Hence, the correct peptide structure has been assigned. Trifa-CC of the protea beetle is an unusual member of the AKH family that is unique in its post-translational modification. Since it increases the concentration of carbohydrates and proline in the haemolymph when injected into the protea beetle, and

  15. Locust adipokinetic hormones: carrier-independent transport and differential inactivation at physiological concentrations during rest and flight.

    PubMed Central

    Oudejans, R C; Vroemen, S F; Jansen, R F; Van der Horst, D J

    1996-01-01

    Since concomitant release of structurally related peptide hormones with apparently similar functions seems to be a general concept in endocrinology, we have studied the dynamics of the lifetime of the three known adipokinetic hormones (AKHs) of the migratory locust, which control flight-directed mobilization of carbohydrate and lipid from fat body stores. Although the structure of the first member of the AKHs has been known for 20 years, until now, reliable data on their inactivation and removal from the hemolymph are lacking, because measurement requires AKHs with high specific radioactivity. Employing tritiated AKHs with high specific radioactivity, obtained by catalytic reduction with tritium gas of the dehydroLeu2 analogues of the AKHs synthesized by the solid-phase procedure, studies with physiological doses of as low as 1.0 pmol per locust could be conducted. The AKHs appear to be transported in the hemolymph in their free forms and not associated with a carrier protein, despite their strong hydrophobicity. Application of AKHs in their free form in in vivo and in vitro studies therefore now has been justified. We have studied the degradation of the three AKHs during rest and flight. The first cleavage step by an endopeptidase is crucial, since the resulting degradation products lack any adipokinetic activity. Half-lives for AKH-I, -II and -III were 51, 40, and 5 min, respectively, for rest conditions and 35, 37, and 3 min, respectively, during flight. The rapid and differential degradation of structurally related hormones leads to changes in the ratio in which they are released and therefore will have important consequences for concerted hormone action at the level of the target organ or organs, suggesting that each of the known AKHs may play its own biological role in the overall syndrome of insect flight. PMID:8710926

  16. Molecular characterization, tissue distribution, and ultrastructural localization of adipokinetic hormones in the CNS of the firebug Pyrrhocoris apterus (Heteroptera, Insecta).

    PubMed

    Kodrík, Dalibor; Stašková, Tereza; Jedličková, Veronika; Weyda, František; Závodská, Radka; Pflegerová, Jitka

    2015-01-01

    Adipokinetic hormones (AKHs) are a group of insect metabolic neurohormones, synthesized and released from an endocrine retrocerebral gland, the corpus cardiacum (CC). Small amounts of AKH have also been identified in the brain, although their role in this organ is not clear. To address this gap in the knowledge about insect brain biology, we studied the nucleotide sequence, tissue distribution, and subcellular localization of AKHs in the brain and CC of the firebug Pyrrhocoris apterus. This insect expresses two AKHs; the octapeptides Pyrap-AKH and Peram-CAH-II, the presence of which was documented in the both studied organs. In situ hybridization and quantitative reverse-transcription (q-RT)-PCR revealed the expression of the genes encoding for both AKHs not only in the CC, but also in brain. Electron microscopy analysis of the brain revealed the presence of these hormones in specialized secretory granules localized predominantly in the cellular bodies of neurons. The hormones might be transported from the granules into the axons, where they could play a role in neuronal signaling. Under acute stress induced by the injection of 3μmol KCl, the level of AKHs in the brain increased to a greater extent than that in the CC. These results might indicate an enhanced role of brain-derived AKHs in defence reaction under acute stress situations. PMID:25449136

  17. A unique charged tyrosine-containing member of the adipokinetic hormone/red-pigment-concentrating hormone peptide family isolated and sequenced from two beetle species.

    PubMed

    Gäde, G

    1991-05-01

    An identical neuropeptide was isolated from the corpora cardiaca of two beetle species, Melolontha melolontha and Geotrupes stercorosus. Its primary structure was determined by pulsed-liquid-phase sequencing employing Edman chemistry after enzymically deblocking the N-terminal pyroglutamate residue. The C-terminus was also blocked, as indicated by the lack of digestion when the peptide was incubated with carboxypeptidase A. The sequence of this peptide, which is designated Mem-CC, is pGlu-Leu-Asn-Tyr-Ser-Pro-Asp-Trp-NH2. It is a new member of the adipokinetic hormone/red-pigment-concentrating hormone (AKH/RPCH) family of peptides with two unusual structural features: it is charged and contains a tyrosine residue at position 4, where all other family members have a phenylalanine residue. Structure-activity studies in the migratory locust (Locusta migratoria) and the American cockroach (Periplaneta americana) revealed that the peptide was poorly active, owing to its structural uniqueness. PMID:2039445

  18. Isolation and structure of a novel charged member of the red-pigment-concentrating hormone-adipokinetic hormone family of peptides isolated from the corpora cardiaca of the blowfly Phormia terraenovae (Diptera).

    PubMed

    Gäde, G; Wilps, H; Kellner, R

    1990-07-15

    A hypertrehalosaemic neuropeptide from the corpora cardiaca of the blowfly Phormia terraenovae has been isolated by reversed-phase h.p.l.c., and its primary structure was determined by pulsed-liquid phase sequencing employing Edman chemistry after enzymically deblocking the N-terminal pyroglutamate residue. The C-terminus was also blocked, as indicated by the lack of digestion when the peptide was incubated with carboxypeptidase A. The octapeptide has the sequence pGlu-Leu-Thr-Phe-Ser-Pro-Asp-Trp-NH2 and is clearly defined as a novel member of the RPCH/AKH (red-pigment-concentrating hormone/adipokinetic hormone) family of peptides. It is the first charged member of this family to be found. The synthetic peptide causes an increase in the haemolymph carbohydrate concentration in a dose-dependent fashion in blowflies and therefore is named 'Phormia terraenovae hypertrehalosaemic hormone' (Pht-HrTH). In addition, receptors in the fat-body of the American cockroach (Periplaneta americana) recognize the peptide, resulting in carbohydrate elevation in the blood. However, fat-body receptors of the migratory locust (Locusta migratoria) do not recognize this charged molecule, and thus no lipid mobilization is observed in this species. PMID:2386478

  19. Effects of chronic administration of adipokinetic and hypertrehalosemic hormone on animal behavior, BDNF, and CREB expression in the hippocampus and neurogenesis in mice.

    PubMed

    Mutlu, Oguz; Gumuslu, Esen; Kokturk, Sibel; Ulak, Guner; Akar, Furuzan; Erden, Faruk; Kaya, Havva; Tanyeri, Pelin

    2016-02-01

    Neurosecretory cells in corpus cardiacum of insects synthesize a set of hormones that are called adipokinetic, hypertrehalosaemic or hyperprolinaemic, depending on insect in question. This study investigated effects of chronic administration of Anax imperator adipokinetic hormone (Ani-AKH), Libellula auripennis adipokinetic hormone (Lia-AKH), and Phormia-Terra hypertrehalosaemic hormone (Pht-HrTH) on depression, anxiety, analgesy, locomotion in forced swimming (FST), elevated plus-maze (EPM), hot plate, and locomotor activity tests. Ani-AKH (1 and 2 mg/kg), Lia-AKH (1 and 2 mg/kg), and Pht-HrTH (1 and 2 mg/kg) had antidepressant effects in forced swimming test. Lia-AKH (2 mg/kg) and Pht-HrTH (1 and 2 mg/kg) had anxiolytic effects when given chronically in elevated plus-maze test. Ani-AKH (1 and 2 mg/kg) and Pht-HrTH (2 mg/kg) had antinociceptive effects in hot plate test in male balb-c mice. Ani-AKH (2 mg/kg), Lia-AKH (1 and 2 mg/kg), and Pht-HrTH had locomotion-enhancing effects in locomotor activity test in male balb-c mice. Drug treatment significantly increased brain-derived neurotrophic factor (BDNF) and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) gene expression levels compared to control levels. Pht-HrTH and Ani-AKH groups had significantly increased numbers of BrdU-labeled cells, while neurodegeneration was lower in the Pht-HrTH group. Our study showed that AKH/RPCH family peptides may be used in treatment of psychiatric illness such as depression and anxiety, in treatment of pain and in diseases related to locomotion system. AKH/RPCH family peptides increase neurotrophic factors in brain and have potential proliferative and neuroprotective effects in hippocampal neurogenesis and neurodegeneration.

  20. Two novel tyrosine-containing peptides (Tyr(4)) of the adipokinetic hormone family in beetles of the families Coccinellidae and Silphidae.

    PubMed

    Gäde, Gerd; Šimek, Petr; Marco, Heather G

    2015-11-01

    Novel members of the adipokinetic hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one adipokinetic hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC-MS). The multiple MS(N) electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC-MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle adipokinetic peptides, because this feature has not been found in another order other than Coleoptera. PMID:26031827

  1. Two novel tyrosine-containing peptides (Tyr(4)) of the adipokinetic hormone family in beetles of the families Coccinellidae and Silphidae.

    PubMed

    Gäde, Gerd; Šimek, Petr; Marco, Heather G

    2015-11-01

    Novel members of the adipokinetic hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one adipokinetic hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC-MS). The multiple MS(N) electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC-MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

  2. The adipokinetic neuropeptide of Mantodea. Sequence elucidation and evolutionary relationships.

    PubMed

    Gäde, G

    1991-03-01

    A neuropeptide with adipokinetic activity in Locusta migratoria and the mantid Empusa pennata, and hypertrehalosaemic activity in Periplaneta americana, was isolated by reversed-phase high performance liquid chromatography from corpora cardiaca of the mantids E. pennata and Sphodromantis sp. After brief enzymatic digestion by 5-oxoprolylpeptidase the primary structure of the peptide of each species was determined by pulsed-liquid phase sequencing employing Edman degradation. The C-terminus of both peptides was blocked, as indicated by the lack of digestion with carboxypeptidase A. The peptides of both species were identical: a blocked, uncharged octapeptide with the sequence L-Glu-Val-Asn-Phe-Thr-Pro-Asn-Trp-NH2. The peptide is now called mantid adipokinetic hormone (Emp-AKH). The synthetic peptide was chromatographically indistinguishable from the natural compound and increased blood lipids in locusts and blood carbohydrates in cockroaches when administered in low doses. The structural features clearly define the peptide as a novel member of the large AKH/RPCH-family of peptides. Seven amino-acid residues are at identical positions in Emp-AKH when compared with the adipokinetic hormone of a dragonfly (Lia-AKH) and the hypertrehalosaemic hormone I from the American cockroach (Pea-CAH-I). Evolutionary relationships to other insect orders are discussed.

  3. The growth hormone secretagogue receptor.

    PubMed

    Cruz, Conrad Russell Young; Smith, Roy G

    2008-01-01

    The neuroendocrine hormone ghrelin, a recently discovered acylated peptide with numerous activities in various organ systems, exerts most of its known effects on the body through a highly conserved G-protein-coupled receptor, the growth hormone secretagogue receptor (GHSR) type 1a. The GHSR's wide expression in different tissues reflects activity of its ligands in the hypothalamic-pituitary, cardiovascular, immune, gastrointestinal, and reproductive systems. Its extensive cellular distribution along with its important actions on the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis and other neuroendocrine and metabolic systems suggest a pivotal role in governing the mechanisms of aging. A more comprehensive characterization of the receptor, and a more thorough identification of its various agonists and antagonists, will undoubtedly introduce important clinical applications in age-related states like anorexia, cardiovascular pathology, cancer, impaired energy balance, and immune dysfunction. Although present knowledge points to a single functional receptor and a single endogenous ligand, recent investigations suggest the existence of additional GHSR subtypes, as well as other endogenous agonists. It has been more than a decade since the landmark cloning of this ubiquitous, highly conserved receptor, and the considerable extent of its effects on normal physiology and disease states have filled the literature with incredible insights on how organisms regulate various functions through subtle signaling processes. But science has barely scratched the surface, and we can be assured that the mysteries surrounding the precise nature of ghrelin and its receptor(s) are only beginning to unravel. PMID:17983853

  4. [Pathologic manifestations of hormonal receptor mutations].

    PubMed

    Milgrom, E

    2000-01-01

    Mutations of receptor genes are involved in various aspects of thyroid and gonadal pathology. Activating mutations of TSH and LH receptors are associated with hyperthyroidism and premature puberty. These mutations are dominant and lead to the synthesis of a constitutive receptor, i.e. a receptor active even in the absence of hormone. Inactivating mutations of TSH, gonadotropin and GnRH receptors are recessive. They determine either a hypothyroidism or a hypogonadism. In the case of alterations of gonadotropin receptors the hypogonadism is hypergonadotrophic. It is hypogonadotrophic in the case of mutations of the GnRH receptor. PMID:10989556

  5. Rapid steroid hormone actions via membrane receptors.

    PubMed

    Schwartz, Nofrat; Verma, Anjali; Bivens, Caroline B; Schwartz, Zvi; Boyan, Barbara D

    2016-09-01

    Steroid hormones regulate a wide variety of physiological and developmental functions. Traditional steroid hormone signaling acts through nuclear and cytosolic receptors, altering gene transcription and subsequently regulating cellular activity. This is particularly important in hormonally-responsive cancers, where therapies that target classical steroid hormone receptors have become clinical staples in the treatment and management of disease. Much progress has been made in the last decade in detecting novel receptors and elucidating their mechanisms, particularly their rapid signaling effects and subsequent impact on tumorigenesis. Many of these receptors are membrane-bound and lack DNA-binding sites, functionally separating them from their classical cytosolic receptor counterparts. Membrane-bound receptors have been implicated in a number of pathways that disrupt the cell cycle and impact tumorigenesis. Among these are pathways that involve phospholipase D, phospholipase C, and phosphoinositide-3 kinase. The crosstalk between these pathways has been shown to affect apoptosis and proliferation in cardiac cells, osteoblasts, and chondrocytes as well as cancer cells. This review focuses on rapid signaling by 17β-estradiol and 1α,25-dihydroxy vitamin D3 to examine the integrated actions of classical and rapid steroid signaling pathways both in contrast to each other and in concert with other rapid signaling pathways. This new approach lends insight into rapid signaling by steroid hormones and its potential for use in targeted drug therapies that maximize the benefits of traditional steroid hormone-directed therapies while mitigating their less desirable effects. PMID:27288742

  6. Nuclear hormone receptors in podocytes

    PubMed Central

    2012-01-01

    Nuclear receptors are a family of ligand-activated, DNA sequence-specific transcription factors that regulate various aspects of animal development, cell proliferation, differentiation, and homeostasis. The physiological roles of nuclear receptors and their ligands have been intensively studied in cancer and metabolic syndrome. However, their role in kidney diseases is still evolving, despite their ligands being used clinically to treat renal diseases for decades. This review will discuss the progress of our understanding of the role of nuclear receptors and their ligands in kidney physiology with emphasis on their roles in treating glomerular disorders and podocyte injury repair responses. PMID:22995171

  7. Experience with hormone receptors in renal cancer.

    PubMed

    Romics, I; Rüssel, C; Bach, D

    1990-01-01

    The hormone receptor concentrations in tumour tissues from 20 renal carcinoma patients were determined before postoperative medroxyprogesterone acetate (MPA) therapy was started. Except for glucocorticoid receptors, the concentrations were either not measurable or were extremely low. The question is whether MPA therapy, solely on the strength of its character as a general roborant, is still useful in the treatment of renal tumours, even when it fails to exercise primary influence because of the absence of suitable receptors. None of the 20 patients was treated with MPA.

  8. Thyroid hormone receptors bind to defined regions of the growth hormone and placental lactogen genes.

    PubMed Central

    Barlow, J W; Voz, M L; Eliard, P H; Mathy-Harter, M; De Nayer, P; Economidis, I V; Belayew, A; Martial, J A; Rousseau, G G

    1986-01-01

    The intracellular receptor for thyroid hormone is a protein found in chromatin. Since thyroid hormone stimulates transcription of the growth hormone gene through an unknown mechanism, the hypothesis that the thyroid hormone-receptor complex interacts with defined regions of this gene has been investigated in a cell-free system. Nuclear extracts from human lymphoblastoid IM-9 cells containing thyroid hormone receptors were incubated with L-3,5,3'-tri[125I]iodothyronine and calf thymus DNA-cellulose. Restriction fragments of the human growth hormone gene were added to determine their ability to inhibit labeled receptor binding to DNA-cellulose. These fragments encompassed nucleotide sequences from about three kilobase pairs upstream to about four kilobase pairs downstream from the transcription initiation site. The thyroid hormone-receptor complex bound preferentially to the 5'-flanking sequences of the growth hormone gene in a region between nucleotide coordinates -290 and -129. The receptor also bound to an analogous promoter region in the human placental lactogen gene, which has 92% nucleotide sequence homology with the growth hormone gene. These binding regions appear to be distinct from those that are recognized by the receptor for glucocorticoids, which stimulate growth hormone gene expression synergistically with thyroid hormone. The presence of thyroid hormone was required for binding of its receptor to the growth hormone gene promoter, suggesting that thyroid hormone renders the receptor capable of recognizing specific gene regions. PMID:3466175

  9. Immunoprecipitation of the parathyroid hormone receptor

    SciTech Connect

    Wright, B.S.; Tyler, G.A.; O'Brien, R.; Caporale, L.H.; Rosenblatt, M.

    1987-01-01

    An /sup 125/I-labeled synthetic analog of bovine parathyroid hormone, (8-norleucine,18-norleucine,34-tyrosine)PTH-(1-34) amide ((Nle)PTH-(1-34)-NH/sub 2/), purified by high-pressure liquid chromatography (HPLC), was employed to label the parathyroid hormone (PTH) receptor in cell lines derived from PTH target tissues: the ROS 17/2.8 rat osteosarcoma of bone and the CV1 and COS monkey kidney lines. After incubation of the radioligand with intact cultured cells, the hormone was covalently attached to receptors by using either a photoaffinity technique or chemical (affinity) crosslinking. In each case, covalent labeling was specific, as evidenced by a reduction of labeling when excess competing nonradioactive ligand was present. After covalent attachment of radioligand, membranes were prepared form the cells and solubilized in the nonionic detergent Nonidet P-40 or octyl glucoside. Analysis of the immunoprecipitate on NaDod-SO/sub 4//polyacrylamide gel electrophoresis followed by autoradiography revealed the presence of a doublet of apparent molecular mass 69-70 kDa. Specifically labeled bands of approximate molecular mass 95 and 28 kDa were also observed. The anti-PTH IgG was affinity purified by passage over a PTH-Sepharose column and used to made an immunoaffinity column. These studies suggest that the use of an anti-PTH antiserum that binds receptor-bound hormone is likely to be a useful step in the further physicochemical characterization and purification of the PTH receptor.

  10. NUREBASE: database of nuclear hormone receptors.

    PubMed

    Duarte, Jorge; Perrière, Guy; Laudet, Vincent; Robinson-Rechavi, Marc

    2002-01-01

    Nuclear hormone receptors are an abundant class of ligand activated transcriptional regulators, found in varying numbers in all animals. Based on our experience of managing the official nomenclature of nuclear receptors, we have developed NUREBASE, a database containing protein and DNA sequences, reviewed protein alignments and phylogenies, taxonomy and annotations for all nuclear receptors. The reviewed NUREBASE is completed by NUREBASE_DAILY, automatically updated every 24 h. Both databases are organized under a client/server architecture, with a client written in Java which runs on any platform. This client, named FamFetch, integrates a graphical interface allowing selection of families, and manipulation of phylogenies and alignments. NUREBASE sequence data is also accessible through a World Wide Web server, allowing complex queries. All information on accessing and installing NUREBASE may be found at http://www.ens-lyon.fr/LBMC/laudet/nurebase.html.

  11. Nuclear hormone receptors put immunity on sterols

    PubMed Central

    Santori, Fabio R.

    2015-01-01

    Nuclear hormone receptors (NHRs) are transcription factors regulated by small molecules. The functions of NHRs range from development of primary and secondary lymphoid organs, to regulation of differentiation and function of DCs, macrophages and T cells. The human genome has 48 classic (hormone and vitamin receptors) and non-classic (all others) NHRs; 17 non-classic receptors are orphans, meaning that the endogenous ligand is unknown. Understanding the function of orphan NHRs requires the identification of their natural ligands. The mevalonate pathway, including its sterol and non-sterol intermediates and derivatives, is a source of ligands for many classic and non-classic NHRs. For example, cholesterol biosynthetic intermediates (CBIs) are natural ligands for RORγ/γt. CBIs are universal endogenous metabolites in mammalian cells, and to study NHRs that bind CBIs requires ligand-free reporters system in sterol auxotroph cells. Furthermore, RORγ/γt shows broad specificity to sterol lipids, suggesting that RORγ/γt is either a general sterol sensor or specificity is defined by an abundant endogenous ligand. Unlike other NHRs, which regulate specific metabolic pathways, there is no connection between the genetic programs induced by RORγ/γt and ligand biosynthesis. In this review we summarize the roles of non-classic NHRs and their potential ligands in the immune system. PMID:26222181

  12. Nuclear hormone receptors put immunity on sterols.

    PubMed

    Santori, Fabio R

    2015-10-01

    Nuclear hormone receptors (NHRs) are transcription factors regulated by small molecules. The functions of NHRs range from development of primary and secondary lymphoid organs, to regulation of differentiation and function of DCs, macrophages and T cells. The human genome has 48 classic (hormone and vitamin receptors) and nonclassic (all others) NHRs; 17 nonclassic receptors are orphans, meaning that the endogenous ligand is unknown. Understanding the function of orphan NHRs requires the identification of their natural ligands. The mevalonate pathway, including its sterol and nonsterol intermediates and derivatives, is a source of ligands for many classic and nonclassic NHRs. For example, cholesterol biosynthetic intermediates (CBIs) are natural ligands for RORγ/γt. CBIs are universal endogenous metabolites in mammalian cells, and to study NHRs that bind CBIs requires ligand-free reporters system in sterol auxotroph cells. Furthermore, RORγ/γt shows broad specificity to sterol lipids, suggesting that RORγ/γt is either a general sterol sensor or specificity is defined by an abundant endogenous ligand. Unlike other NHRs, which regulate specific metabolic pathways, there is no connection between the genetic programs induced by RORγ/γt and ligand biosynthesis. In this review, we summarize the roles of nonclassic NHRs and their potential ligands in the immune system.

  13. The growth hormone receptor: mechanism of activation and clinical implications.

    PubMed

    Brooks, Andrew J; Waters, Michael J

    2010-09-01

    Growth hormone is widely used clinically to promote growth and anabolism and for other purposes. Its actions are mediated via the growth hormone receptor, both directly by tyrosine kinase activation and indirectly by induction of insulin-like growth factor 1 (IGF-1). Insensitivity to growth hormone (Laron syndrome) can result from mutations in the growth hormone receptor and can be treated with IGF-1. This treatment is, however, not fully effective owing to the loss of the direct actions of growth hormone and altered availability of exogenous IGF-1. Excessive activation of the growth hormone receptor by circulating growth hormone results in gigantism and acromegaly, whereas cell transformation and cancer can occur in response to autocrine activation of the receptor. Advances in understanding the mechanism of receptor activation have led to a model in which the growth hormone receptor exists as a constitutive dimer. Binding of the hormone realigns the subunits by rotation and closer apposition, resulting in juxtaposition of the catalytic domains of the associated tyrosine-protein kinase JAK2 below the cell membrane. This change results in activation of JAK2 by transphosphorylation, then phosphorylation of receptor tyrosines in the cytoplasmic domain, which enables binding of adaptor proteins, as well as direct phosphorylation of target proteins. This model is discussed in the light of salient information from closely related class 1 cytokine receptors, such as the erythropoietin, prolactin and thrombopoietin receptors. PMID:20664532

  14. Steroid Hormone Receptor Signals as Prognosticators for Urothelial Tumor

    PubMed Central

    Ide, Hiroki; Miyamoto, Hiroshi

    2015-01-01

    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. PMID:26770009

  15. Signal transduction by the growth hormone receptor

    SciTech Connect

    Waters, M.J.; Rowlinson, S.W.; Clarkson, R.W.

    1994-12-31

    It has been proposed that dimerization of identical receptor subunits by growth hormone (GH) is the mechanism of signal transduction across the cell membrane. We present here data with analogs of porcine GH (pGH), with GH receptors (GHR) mutated in the dimerization domain and with monoclonal antibodies to the GHR which indicate that dimerization is necessary but not sufficient for transduction. We also report nuclear uptake of GH both in vivo and in vitro, along with nuclear localization of the receptor and GH-binding protein (GHBP). This suggests that GH acts directly at the nucleus, and one possible target for this action is a rapid increase in transcription of C/EBP delta seen in 3T3-F442A cells in response to GH. This tyrosine kinase-dependent event may be an archetype for induction of other immediate early gene transcription factors which then interact to determine the programming of the subsequent transcriptional response to GH. 29 refs., 1 fig., 1 tab.

  16. Evidence for activity-regulated hormone-binding cooperativity across glycoprotein hormone receptor homomers.

    PubMed

    Zoenen, Maxime; Urizar, Eneko; Swillens, Stéphane; Vassart, Gilbert; Costagliola, Sabine

    2012-01-01

    Glycoprotein hormone receptors show strong negative cooperativity. As a consequence, at physiological hormone concentrations, a single agonist binds to a receptor dimer. Here we present evidence that constitutively active receptors lose cooperative allosteric regulation in direct relation with their basal activity. The most constitutive mutants lost nearly all cooperativity and showed an increase of initial tracer binding, reflecting the ability of each protomer to bind with equal affinity. Allosteric interaction between the protomers takes place at the transmembrane domain. The allosteric message resulting from hormone binding to the ectodomain of one protomer travels 'downward' to its transmembrane domain, before affecting the transmembrane domain of the other protomer. This results in transmission of an 'upward' message lowering the binding affinity of the ectodomain of the second protomer. Our results demonstrate a direct relation between the conformational changes associated with activation of the transmembrane domain and the allosteric behaviour of glycoprotein hormone receptors dimers.

  17. Structural Basis for Antibody Discrimination between Two Hormones That Recognize the Parathyroid Hormone Receptor

    SciTech Connect

    McKinstry, William J.; Polekhina, Galina; Diefenbach-Jagger, Hannelore; Ho, Patricia W.M.; Sato, Koh; Onuma, Etsuro; Gillespie, Matthew T.; Martin, T. John; Parker, Michael W.

    2009-08-18

    Parathyroid hormone-related protein (PTHrP) plays a vital role in the embryonic development of the skeleton and other tissues. When it is produced in excess by cancers it can cause hypercalcemia, and its local production by breast cancer cells has been implicated in the pathogenesis of bone metastasis formation in that disease. Antibodies have been developed that neutralize the action of PTHrP through its receptor, parathyroid hormone receptor 1, without influencing parathyroid hormone action through the same receptor. Such neutralizing antibodies against PTHrP are therapeutically effective in animal models of the humoral hypercalcemia of malignancy and of bone metastasis formation. We have determined the crystal structure of the complex between PTHrP (residues 1-108) and a neutralizing monoclonal anti-PTHrP antibody that reveals the only point of contact is an {alpha}-helical structure extending from residues 14-29. Another striking feature is that the same residues that interact with the antibody also interact with parathyroid hormone receptor 1, showing that the antibody and the receptor binding site on the hormone closely overlap. The structure explains how the antibody discriminates between the two hormones and provides information that could be used in the development of novel agonists and antagonists of their common receptor.

  18. Structural Basis for Antibody Discrimination between Two Hormones That Recognize the Parathyroid Hormone Receptor*

    PubMed Central

    McKinstry, William J.; Polekhina, Galina; Diefenbach-Jagger, Hannelore; Ho, Patricia W. M.; Sato, Koh; Onuma, Etsuro; Gillespie, Matthew T.; Martin, T. John; Parker, Michael W.

    2009-01-01

    Parathyroid hormone-related protein (PTHrP) plays a vital role in the embryonic development of the skeleton and other tissues. When it is produced in excess by cancers it can cause hypercalcemia, and its local production by breast cancer cells has been implicated in the pathogenesis of bone metastasis formation in that disease. Antibodies have been developed that neutralize the action of PTHrP through its receptor, parathyroid hormone receptor 1, without influencing parathyroid hormone action through the same receptor. Such neutralizing antibodies against PTHrP are therapeutically effective in animal models of the humoral hypercalcemia of malignancy and of bone metastasis formation. We have determined the crystal structure of the complex between PTHrP (residues 1–108) and a neutralizing monoclonal anti-PTHrP antibody that reveals the only point of contact is an α-helical structure extending from residues 14–29. Another striking feature is that the same residues that interact with the antibody also interact with parathyroid hormone receptor 1, showing that the antibody and the receptor binding site on the hormone closely overlap. The structure explains how the antibody discriminates between the two hormones and provides information that could be used in the development of novel agonists and antagonists of their common receptor. PMID:19346515

  19. An orphan nuclear hormone receptor that lacks a DNA binding domain and heterodimerizes with other receptors.

    PubMed

    Seol, W; Choi, H S; Moore, D D

    1996-05-31

    SHP is an orphan member of the nuclear hormone receptor superfamily that contains the dimerization and ligand-binding domain found in other family members but lacks the conserved DNA binding domain. In the yeast two-hybrid system, SHP interacted with several conventional and orphan members of the receptor superfamily, including retinoid receptors, the thyroid hormone receptor, and the orphan receptor MB67. SHP also interacted directly with these receptors in vitro. In mammalian cells, SHP specifically inhibited transactivation by the superfamily members with which it interacted. These results suggest that SHP functions as a negative regulator of receptor-dependent signaling pathways. PMID:8650544

  20. Palbociclib in Combination With Tamoxifen as First Line Therapy for Metastatic Hormone Receptor Positive Breast Cancer

    ClinicalTrials.gov

    2016-10-04

    Hormone Receptor Positive Malignant Neoplasm of Breast; Human Epidermal Growth Factor 2 Negative Carcinoma of Breast; Estrogen Receptor Positive Breast Cancer; Progesterone Receptor Positive Tumor; Metastatic Breast Cancer

  1. Identification of an estrogenic hormone receptor in Caenorhabditis elegans

    SciTech Connect

    Mimoto, Ai; Fujii, Madoka; Usami, Makoto; Shimamura, Maki; Hirabayashi, Naoko; Kaneko, Takako; Sasagawa, Noboru; Ishiura, Shoichi

    2007-12-28

    Changes in both behavior and gene expression occur in Caenorhabditis elegans following exposure to sex hormones such as estrogen and progesterone, and to bisphenol A (BPA), an estrogenic endocrine-disrupting compound. However, only one steroid hormone receptor has been identified. Of the 284 known nuclear hormone receptors (NHRs) in C. elegans, we selected nhr-14, nhr-69, and nhr-121 for analysis as potential estrogenic hormone receptors, because they share sequence similarity with the human estrogen receptor. First, the genes were cloned and expressed in Escherichia coli, and then the affinity of each protein for estrogen was determined using a surface plasmon resonance (SPR) biosensor. All three NHRs bound estrogen in a dose-dependent fashion. To evaluate the specificity of the binding, we performed a solution competition assay using an SPR biosensor. According to our results, only NHR-14 was able to interact with estrogen. Therefore, we next examined whether nhr-14 regulates estrogen signaling in vivo. To investigate whether these interactions actually control the response of C. elegans to hormones, we investigated the expression of vitellogenin, an estrogen responsive gene, in an nhr-14 mutant. Semi-quantitative RT-PCR showed that vitellogenin expression was significantly reduced in the mutant. This suggests that NHR-14 is a C. elegans estrogenic hormone receptor and that it controls gene expression in response to estrogen.

  2. [Growth hormone receptor antagonist in the treatment of acromegaly].

    PubMed

    Hubina, Erika; Tóth, Agnes; Kovács, Gábor László; Dénes, Judit; Kovács, László; Góth, Miklós

    2011-05-01

    Exploration of construction, function and interaction of human growth hormone and growth hormone receptor in details resulted in the innovation of the new growth hormone receptor antagonist, pegvisomant. Pegvisomant with different mechanism of action extended the tools of medical management of acromegaly. Importance of the novel treatment modality is high. In one hand the necessity of the strict control of growth hormone/insulin-like growth factor-I axis has been proven regarding the mortality of the disease. On the other hand, despite the use of all current modes of treatment (surgery, radiotherapy, dopamine agonists, somatostatin analogs), a significant cohort of patients with acromegaly remains inadequately controlled. Pegvisomant has been registered in 2004. Since 2006, it has been used in Hungary for the treatment of acromegaly in patients who have had an inadequate response to surgery and/or radiation therapy and/or other medical therapies, or for whom these therapies are not appropriate. Clinical use of pegvisomant in the treatment of acromegaly is effective, well tolerated, and safe, based on international Acrostudy database. In order to improve the efficacy of therapy clinical trials started with pegvisomant and somatostatin analog combination treatment. Evidence of several further effects of the growth hormone/insulin-like growth factor-I axis suggests other potential uses of growth hormone receptor antagonists. PMID:21498159

  3. Rational discovery of novel nuclear hormone receptor antagonists

    NASA Astrophysics Data System (ADS)

    Schapira, Matthieu; Raaka, Bruce M.; Samuels, Herbert H.; Abagyan, Ruben

    2000-02-01

    Nuclear hormone receptors (NRs) are potential targets for therapeutic approaches to many clinical conditions, including cancer, diabetes, and neurological diseases. The crystal structure of the ligand binding domain of agonist-bound NRs enables the design of compounds with agonist activity. However, with the exception of the human estrogen receptor-, the lack of antagonist-bound "inactive" receptor structures hinders the rational design of receptor antagonists. In this study, we present a strategy for designing such antagonists. We constructed a model of the inactive conformation of human retinoic acid receptor- by using information derived from antagonist-bound estrogen receptor-α and applied a computer-based virtual screening algorithm to identify retinoic acid receptor antagonists. Thus, the currently available crystal structures of NRs may be used for the rational design of antagonists, which could lead to the development of novel drugs for a variety of diseases.

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

    PubMed Central

    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. We have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. We 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. Images PMID:3475698

  5. Model for growth hormone receptor activation based on subunit rotation within a receptor dimer

    SciTech Connect

    Brown, Richard J.; Adams, Julian J.; Pelekanos, Rebecca A.; Wan, Yu; McKinstry, William J.; Palethorpe, Kathryn; Seeber, Ruth M.; Monks, Thea A.; Eidne, Karin A.; Parker, Michael W.; Waters, Michael J.

    2010-07-13

    Growth hormone is believed to activate the growth hormone receptor (GHR) by dimerizing two identical receptor subunits, leading to activation of JAK2 kinase associated with the cytoplasmic domain. However, we have reported previously that dimerization alone is insufficient to activate full-length GHR. By comparing the crystal structure of the liganded and unliganded human GHR extracellular domain, we show here that there is no substantial change in its conformation on ligand binding. However, the receptor can be activated by rotation without ligand by inserting a defined number of alanine residues within the transmembrane domain. Fluorescence resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET) and coimmunoprecipitation studies suggest that receptor subunits undergo specific transmembrane interactions independent of hormone binding. We propose an activation mechanism involving a relative rotation of subunits within a dimeric receptor as a result of asymmetric placement of the receptor-binding sites on the ligand.

  6. Hormonal receptors in juvenile nasopharyngeal angiofibroma.

    PubMed

    Farag, M M; Ghanimah, S E; Ragaie, A; Saleem, T H

    1987-02-01

    Specific thermostable androgen receptors were detected in the tissues of nasopharyngeal angiofibroma. The receptors seemed to be specific with high affinity toward DHT more than testosterone. No abnormalities in serum levels of DHT, testosterone, and estradiol-17 beta could be detected in the patients studied. A concept of pathogenesis of the tumor in relation to that reported in literature recently is interpreted in the text.

  7. Nuclear hormone receptor coregulator: role in hormone action, metabolism, growth, and development.

    PubMed

    Mahajan, Muktar A; Samuels, Herbert H

    2005-06-01

    Nuclear hormone receptor coregulator (NRC) (also referred to as activating signal cointegrator-2, thyroid hormone receptor-binding protein, peroxisome proliferator activating receptor-interacting protein, and 250-kDa receptor associated protein) belongs to a growing class of nuclear cofactors widely known as coregulators or coactivators that are necessary for transcriptional activation of target genes. The NRC gene is also amplified and overexpressed in breast, colon, and lung cancers. NRC is a 2063-amino acid protein that harbors a potent N-terminal activation domain (AD1) and a second more centrally located activation domain (AD2) that is rich in Glu and Pro. Near AD2 is a receptor-interacting domain containing an LxxLL motif (LxxLL-1), which interacts with a wide variety of ligand-bound nuclear hormone receptors with high affinity. A second LxxLL motif (LxxLL-2) located in the C-terminal region of NRC is more restricted in its nuclear hormone receptor specificity. The intrinsic activation potential of NRC is regulated by a C-terminal serine, threonine, leucine-regulatory domain. The potential role of NRC as a cointegrator is suggested by its ability to enhance transcriptional activation of a wide variety of transcription factors and from its in vivo association with a number of known transcriptional regulators including CBP/p300. Recent studies in mice indicate that deletion of both NRC alleles leads to embryonic lethality resulting from general growth retardation coupled with developmental defects in the heart, liver, brain, and placenta. NRC(-/-) mouse embryo fibroblasts spontaneously undergo apoptosis, indicating the importance of NRC as a prosurvival and antiapoptotic gene. Studies with 129S6 NRC(+/-) mice indicate that NRC is a pleiotropic regulator that is involved in growth, development, reproduction, metabolism, and wound healing.

  8. Neither bovine somatotropin nor growth hormone-releasing factor alters expression of thyroid hormone receptors in liver and mammary tissues.

    PubMed

    Capuco, A V; Binelli, M; Tucker, H A

    2011-10-01

    Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine to specific nuclear receptors. Organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, have been hypothesized to target the action of thyroid hormones on the mammary gland and play a role in mediating or augmenting a galactopoietic response to bovine somatotropin (bST). Additionally, tissue responsiveness to thyroid hormones may be altered by changes in the number or affinity of nuclear receptors for thyroid hormones. In the present study, effects of bST and bovine growth hormone-releasing factor (bGRF) on thyroid hormone receptors in liver and mammary gland were studied. Lactating Holstein cows received continuous infusions of bST or bGRF for 63 d or served as uninfused controls. Nuclei were isolated from harvested mammary and liver tissues and incubated with [(125)I]-triiodothyronine. Treatments did not alter the capacity or affinity of specific binding sites for triiodothyronine in liver or mammary nuclei. Evaluation of transcript abundance for thyroid hormone receptors showed that isoforms of thyroid hormone receptor or retinoid receptor (which may influence thyroid receptor action) expressed in the mammary gland were not altered by bST or bGRF treatment. Data do not support the hypothesis that administration of bST or bGRF alters sensitivity of mammary tissue by changing expression of thyroid hormone receptors.

  9. Nuclear hormone receptor architecture - form and dynamics: The 2009 FASEB Summer Conference on Dynamic Structure of the Nuclear Hormone Receptors.

    PubMed

    McEwan, Iain J; Nardulli, Ann M

    2009-01-01

    Nuclear hormone receptors (NHRs) represent a large and diverse family of ligand-activated transcription factors involved in regulating development, metabolic homeostasis, salt balance and reproductive health. The ligands for these receptors are typically small hydrophobic molecules such as steroid hormones, thyroid hormone, vitamin D3 and fatty acid derivatives. The first NHR structural information appeared approximately 20 years ago with the solution and crystal structures of the DNA binding domains and was followed by the structure of the agonist and antagonist bound ligand binding domains of different NHR members. Interestingly, in addition to these defined structural features, it has become clear that NHRs also possess significant structural plasticity. Thus, the dynamic structure of the NHRs was the topic of a recent stimulating and informative FASEB Summer Research Conference held in Vermont. PMID:20087432

  10. Prediction of nuclear hormone receptor response elements.

    PubMed

    Sandelin, Albin; Wasserman, Wyeth W

    2005-03-01

    The nuclear receptor (NR) class of transcription factors controls critical regulatory events in key developmental processes, homeostasis maintenance, and medically important diseases and conditions. Identification of the members of a regulon controlled by a NR could provide an accelerated understanding of development and disease. New bioinformatics methods for the analysis of regulatory sequences are required to address the complex properties associated with known regulatory elements targeted by the receptors because the standard methods for binding site prediction fail to reflect the diverse target site configurations. We have constructed a flexible Hidden Markov Model framework capable of predicting NHR binding sites. The model allows for variable spacing and orientation of half-sites. In a genome-scale analysis enabled by the model, we show that NRs in Fugu rubripes have a significant cross-regulatory potential. The model is implemented in a web interface, freely available for academic researchers, available at http://mordor.cgb.ki.se/NHR-scan.

  11. DNA bending by retinoid X receptor-containing retinoid and thyroid hormone receptor complexes.

    PubMed Central

    Lu, X P; Eberhardt, N L; Pfahl, M

    1993-01-01

    Retinoid X receptors (RXR) have been identified as common subunits in the regulation of multiple hormonal signaling pathways. Using circular permutation and phasing analysis of specific response elements, we present evidence that RXR-retinoic acid receptor and RXR-thyroid hormone receptor heterodimer or RXR-RXR homodimer complexes induce directed DNA bends when bound to their cognate response elements. The extent of DNA bending induced by the RXR alpha-containing complexes varied and depended on the structure of the DNA-binding sites and the RXR partners. The overall bending orientation for RXR-containing complexes is directed toward the major groove of the DNA helix at the center of hormone response elements. Our observation implicates DNA bending as a possible mechanism underlying transcriptional regulation of distinct retinoid and thyroid hormone responsive genes. Images PMID:8413250

  12. Sex Hormones and Their Receptors Regulate Liver Energy Homeostasis

    PubMed Central

    Shen, Minqian; Shi, Haifei

    2015-01-01

    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. PMID:26491440

  13. Evolutionary aspects of growth hormones and prolactins and their receptors

    SciTech Connect

    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 /sup 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 /sup 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.

  14. Substantial expression of luteinizing hormone-releasing hormone (LHRH) receptor type I in human uveal melanoma

    PubMed Central

    Schally, Andrew V.; Block, Norman L; Dezso, Balazs; Olah, Gabor; Rozsa, Bernadett; Fodor, Klara; Buglyo, Armin; Gardi, Janos; Berta, Andras; Halmos, Gabor

    2013-01-01

    Uveal melanoma is the most common primary intraocular malignancy in adults, with a very high mortality rate due to frequent liver metastases. Consequently, the therapy of uveal melanoma remains a major clinical challenge and new treatment approaches are needed. For improving diagnosis and designing a rational and effective therapy, it is essential to elucidate molecular characteristics of this malignancy. The aim of this study therefore was to evaluate as a potential therapeutic target the expression of luteinizing hormone-releasing hormone (LHRH) receptor in human uveal melanoma. The expression of LHRH ligand and LHRH receptor transcript forms was studied in 39 human uveal melanoma specimens by RT-PCR using gene specific primers. The binding charachteristics of receptors for LHRH on 10 samples were determined by ligand competition assays. The presence of LHRH receptor protein was further evaluated by immunohistochemistry. The expression of mRNA for type I LHRH receptor was detected in 18 of 39 (46%) of tissue specimens. mRNA for LHRH-I ligand could be detected in 27 of 39 (69%) of the samples. Seven of 10 samples investigated showed high affinity LHRH-I receptors. The specific presence of full length LHRH receptor protein was further confirmed by immunohistochemistry. A high percentage of uveal melanomas express mRNA and protein for type-I LHRH receptors. Our results support the merit of further investigation of LHRH receptors in human ophthalmological tumors. Since diverse analogs of LHRH are in clinical trials or are already used for the treatment of various cancers, these analogs could be considered for the LHRH receptor-based treatment of uveal melanoma. PMID:24077773

  15. Estrogen and Progesterone hormone receptor expression in oral cavity cancer

    PubMed Central

    Biegner, Thorsten; Teriete, Peter; Hoefert, Sebastian; Krimmel, Michael; Munz, Adelheid; Reinert, Siegmar

    2016-01-01

    Background Recent studies have shown an increase in the incidence of oral squamous cell carcinoma (OSCC) in younger patients. The hypothesis that tumors could be hormonally induced during pregnancy or in young female patients without the well-known risk factors alcohol or tobacco abuse seems to be plausible. Material and Methods Estrogen Receptor alpha (ERα) and Progesterone Receptor (PR) expression were analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen. OSCCs were stratified in a young female (n=7) study cohort and older patients (n=46). In the young female study cohort three patients (n=3/7) developed OSCC during or shortly after pregnancy. Breast cancer tissues were used as positive control for ERα and PR expression. Results ERα expression was found in four oral precursor lesions (squamous intraepithelial neoplasia, SIN I-III, n=4/35, 11%) and in five OSCC specimen (n=5/46, 11%). The five ERα positive OSCC samples were older male patients. All patients within the young female study cohort were negatively stained for both ERα and PR. Conclusions ER expression could be regarded as a seldom risk factor for OSCC. PR expression seems to be not relevant for the development of OSCC. Key words:Oral squamous cell carcinoma, estrogen receptor, progesterone receptor, hormone receptor. PMID:27475696

  16. Luteinizing hormone/human chorionic gonadotropin receptors in breast cancer.

    PubMed

    Meduri, G; Charnaux, N; Loosfelt, H; Jolivet, A; Spyratos, F; Brailly, S; Milgrom, E

    1997-03-01

    Recent studies have suggested that human choriogonadotropin (hCG), in addition to its function in regulating steroidogenesis, may also play a role as a growth factor. Immunocytochemistry using two different monoclonal antibodies (LHR29 and LHR1055) raised against the human luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor allowed us to detect this receptor in breast cancer cell lines (T47D, MCF7, and ZR75) in individual cancer biopsies and in benign breast lesions. The receptor was also present in epithelial cells of normal human and sow breast. In the latter, its concentration increased after ovulation. The presence of LH/hCG receptor mRNA was confirmed by reverse transcription-PCR using primers extending over exons 2-4, 5-11, and 9-11. The proportion of LH/hCG-receptor positive cells and the intensity of the immunolabeling varied in individual biopsies, but there was no obvious correlation with the histological type of the cancer. These results are compatible with previous studies suggesting that during pregnancy, hCG is involved in the differentiation of breast glandular epithelium and that this hormone may play an inhibitory role in mammary carcinogenesis and in the growth of breast tumors. PMID:9041186

  17. Genetic Models for the Study of Luteinizing Hormone Receptor Function

    PubMed Central

    Narayan, Prema

    2015-01-01

    The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is essential for fertility in men and women. LHCGR binds luteinizing hormone (LH) as well as the highly homologous chorionic gonadotropin. Signaling from LHCGR is required for steroidogenesis and gametogenesis in males and females and for sexual differentiation in the male. The importance of LHCGR in reproductive physiology is underscored by the large number of naturally occurring inactivating and activating mutations in the receptor that result in reproductive disorders. Consequently, several genetically modified mouse models have been developed for the study of LHCGR function. They include targeted deletion of LH and LHCGR that mimic inactivating mutations in hormone and receptor, expression of a constitutively active mutant in LHCGR that mimics activating mutations associated with familial male-limited precocious puberty and transgenic models of LH and hCG overexpression. This review summarizes the salient findings from these models and their utility in understanding the physiological and pathological consequences of loss and gain of function in LHCGR signaling. PMID:26483755

  18. Thyroid hormone receptor can modulate retinoic acid-mediated axis formation in frog embryogenesis.

    PubMed Central

    Banker, D E; Eisenman, R N

    1993-01-01

    Thyroid hormone receptor acts as a hormone-dependent transcriptional transactivator and as a transcriptional repressor in the absence of thyroid hormone. Specifically, thyroid hormone receptor can repress retinoic acid-induced gene expression through interactions with retinoic acid receptor. (Retinoic acid is a potent teratogen in the frog Xenopus laevis, acting at early embryonic stages to interfere with the formation of anterior structures. Endogenous retinoic acid is thought to act in normal anterior-posterior axis formation.) We have previously shown that thyroid hormone receptor RNA (alpha isotype) is expressed and polysome-associated during Xenopus embryogenesis preceding thyroid gland maturation and endogenous thyroid hormone production (D. E. Banker, J. Bigler, and R. N. Eisenman, Mol. Cell. Biol. 11:5079-5089, 1991). To determine whether thyroid hormone receptor might influence the effects of retinoic acid in early frog development, we have examined the results of ectopic thyroid hormone receptor expression on retinoic acid teratogenesis. We demonstrate that microinjections of full-length thyroid hormone receptor RNA protect injected embryos from retinoic acid teratogenesis. DNA binding is apparently essential to this protective function, as truncated thyroid hormone receptors, lacking DNA-binding domains but including hormone-binding and dimerization domains, do not protect from retinoic acid. We have shown that microinjections of these dominant-interfering thyroid hormone receptors, as well as anti-thyroid hormone receptor antibodies, increase retinoic acid teratogenesis in injected embryos, presumably by inactivating endogenous thyroid hormone receptor. This finding suggests that endogenous thyroid hormone receptors may act to limit retinoic acid sensitivity. On the other hand, after thyroid hormone treatment, ectopic thyroid hormone receptor mediates teratogenesis that is indistinguishable from the dorsoanterior deficiencies produced in retinoic acid

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

    PubMed

    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

    2015-01-01

    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-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. PMID:25916672

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

    PubMed

    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

    2015-01-01

    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-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.

  1. Radioiodination of chicken luteinizing hormone without affecting receptor binding potency

    SciTech Connect

    Kikuchi, M.; Ishii, S. )

    1989-12-01

    By improving the currently used lactoperoxidase method, we were able to obtain radioiodinated chicken luteinizing hormone (LH) that shows high specific binding and low nonspecific binding to a crude plasma membrane fraction of testicular cells of the domestic fowl and the Japanese quail, and to the ovarian granulosa cells of the Japanese quail. The change we made from the original method consisted of (1) using chicken LH for radioiodination that was not only highly purified but also retained a high receptor binding potency; (2) controlling the level of incorporation of radioiodine into chicken LH molecules by employing a short reaction time and low temperature; and (3) fractionating radioiodinated chicken LH further by gel filtration using high-performance liquid chromatography. Specific radioactivity of the final {sup 125}I-labeled chicken LH preparation was 14 microCi/micrograms. When specific binding was 12-16%, nonspecific binding was as low as 2-4% in the gonadal receptors. {sup 125}I-Labeled chicken LH was displaced by chicken LH and ovine LH but not by chicken follicle-stimulating hormone. The equilibrium association constant of quail testicular receptor was 3.6 x 10(9) M-1. We concluded that chicken LH radioiodinated by the present method is useful for studies of avian LH receptors.

  2. Immunohistochemical analysis of steroid hormone receptors in nasopharyngeal angiofibromas.

    PubMed

    Gatalica, Z

    1998-05-15

    Juvenile nasopharyngeal angiofibroma arises almost exclusively in pubertal and adolescent men and has potentially aggressive behavior with a spread into adjoining sinuses and bone destruction. It is classically being regarded as an androgen hormone-dependent tumor, but no in situ evaluation of androgen receptors has been done. The author has examined eight nasopharyngeal angiofibromas (six primary and two recurrent tumors) for the expression of androgen receptor (AR), estrogen receptor (ER) and progesterone receptor (PR) using immunohistochemical methods and compared those results with a sex- and age-matched control group consisting of eight samples of nasal turbinates. No ER or PR were found in any of the tumor components, nor have they been detected in control nasal turbinates. Angiofibromas were characterized by variable weak (+) nuclear androgen receptor immunoreactivity found in a minority of endothelial and stromal cells, similar to the normal turbinates. These results argue against the significant role of androgen receptor in the growth of nasal angiofibromas and corroborate previous observations of an unpredictable response of these neoplasms to antiandrogen therapy.

  3. DEHP reduces thyroid hormones via interacting with hormone synthesis-related proteins, deiodinases, transthyretin, receptors, and hepatic enzymes in rats.

    PubMed

    Liu, Changjiang; Zhao, Letian; Wei, Li; Li, Lianbing

    2015-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used extensively in many personal care and consumer products, resulting in widespread nonoccupational human exposure through multiple routes and media. Limited studies suggest that exposure to DEHP may be associated with altered thyroid function, but detailed mechanisms are unclear. In order to elucidate potential mechanisms by which DEHP disturbs thyroid hormone homeostasis, Sprague-Dawley (SD) rats were dosed with DEHP by gavage at 0, 250, 500, and 750 mg/kg/day for 30 days and sacrificed within 24 h after the last dose. Gene expressions of thyroid hormone receptors, deiodinases, transthyretin, and hepatic enzymes were measured by RT-PCR; protein levels of transthyretin were also analyzed by Western blot. Results showed that DEHP caused histological changes in the thyroid and follicular epithelial cell hypertrophy and hyperplasia were observed. DEHP significantly reduced thyroid hormones (T3, T4) and thyrotropin releasing hormone (TRH) levels, whereas thyroid stimulating hormone (TSH) was not affected. After exposure to DEHP, biosynthesis of thyroid hormones was suppressed, and sodium iodide symporter (NIS) and thyroid peroxidase (TPO) levels were significantly reduced. Additionally, levels of deiodinases and transthyretin were also affected. TSH receptor (TSHr) level was downregulated, while TRH receptor (TRHr) level was upregulated. Metabolism of thyroid hormones was accelerated due to elevated gene expression of hepatic enzymes (UDPGTs and CYP2B1) by DEHP. Taken together, observed findings indicate that DEHP could reduce thyroid hormones through influencing biosynthesis, biotransformation, biotransport, receptor levels, and metabolism of thyroid hormones. PMID:25913319

  4. DEHP reduces thyroid hormones via interacting with hormone synthesis-related proteins, deiodinases, transthyretin, receptors, and hepatic enzymes in rats.

    PubMed

    Liu, Changjiang; Zhao, Letian; Wei, Li; Li, Lianbing

    2015-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used extensively in many personal care and consumer products, resulting in widespread nonoccupational human exposure through multiple routes and media. Limited studies suggest that exposure to DEHP may be associated with altered thyroid function, but detailed mechanisms are unclear. In order to elucidate potential mechanisms by which DEHP disturbs thyroid hormone homeostasis, Sprague-Dawley (SD) rats were dosed with DEHP by gavage at 0, 250, 500, and 750 mg/kg/day for 30 days and sacrificed within 24 h after the last dose. Gene expressions of thyroid hormone receptors, deiodinases, transthyretin, and hepatic enzymes were measured by RT-PCR; protein levels of transthyretin were also analyzed by Western blot. Results showed that DEHP caused histological changes in the thyroid and follicular epithelial cell hypertrophy and hyperplasia were observed. DEHP significantly reduced thyroid hormones (T3, T4) and thyrotropin releasing hormone (TRH) levels, whereas thyroid stimulating hormone (TSH) was not affected. After exposure to DEHP, biosynthesis of thyroid hormones was suppressed, and sodium iodide symporter (NIS) and thyroid peroxidase (TPO) levels were significantly reduced. Additionally, levels of deiodinases and transthyretin were also affected. TSH receptor (TSHr) level was downregulated, while TRH receptor (TRHr) level was upregulated. Metabolism of thyroid hormones was accelerated due to elevated gene expression of hepatic enzymes (UDPGTs and CYP2B1) by DEHP. Taken together, observed findings indicate that DEHP could reduce thyroid hormones through influencing biosynthesis, biotransformation, biotransport, receptor levels, and metabolism of thyroid hormones.

  5. Plant nuclear hormone receptors: a role for small molecules in protein-protein interactions.

    PubMed

    Lumba, Shelley; Cutler, Sean; McCourt, Peter

    2010-01-01

    Plant hormones are a group of chemically diverse small molecules that direct processes ranging from growth and development to biotic and abiotic stress responses. Surprisingly, genome analyses suggest that classic animal nuclear hormone receptor homologs do not exist in plants. It now appears that plants have co-opted several protein families to perceive hormones within the nucleus. In one solution to the problem, the hormones auxin and jasmonate (JA) act as “molecular glue” that promotes protein-protein interactions between receptor F-boxes and downstream corepressor targets. In another solution, gibberellins (GAs) bind and elicit a conformational change in a novel soluble receptor family related to hormone-sensitive lipases. Abscisic acid (ABA), like GA, also acts through an allosteric mechanism involving a START-domain protein. The molecular identification of plant nuclear hormone receptors will allow comparisons with animal nuclear receptors and testing of fundamental questions about hormone function in plant development and evolution.

  6. Discovery and Development of Small Molecule Allosteric Modulators of Glycoprotein Hormone Receptors

    PubMed Central

    Nataraja, Selvaraj G.; Yu, Henry N.; Palmer, Stephen S.

    2015-01-01

    Glycoprotein hormones, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid-stimulating hormone (TSH) are heterodimeric proteins with a common α-subunit and hormone-specific β-subunit. These hormones are dominant regulators of reproduction and metabolic processes. Receptors for the glycoprotein hormones belong to the family of G protein-coupled receptors. FSH receptor (FSHR) and LH receptor are primarily expressed in somatic cells in ovary and testis to promote egg and sperm production in women and men, respectively. TSH receptor is expressed in thyroid cells and regulates the secretion of T3 and T4. Glycoprotein hormones bind to the large extracellular domain of the receptor and cause a conformational change in the receptor that leads to activation of more than one intracellular signaling pathway. Several small molecules have been described to activate/inhibit glycoprotein hormone receptors through allosteric sites of the receptor. Small molecule allosteric modulators have the potential to be administered orally to patients, thus improving the convenience of treatment. It has been a challenge to develop a small molecule allosteric agonist for glycoprotein hormones that can mimic the agonistic effects of the large natural ligand to activate similar signaling pathways. However, in the past few years, there have been several promising reports describing distinct chemical series with improved potency in preclinical models. In parallel, proposal of new structural model for FSHR and in silico docking studies of small molecule ligands to glycoprotein hormone receptors provide a giant leap on the understanding of the mechanism of action of the natural ligands and new chemical entities on the receptors. This review will focus on the current status of small molecule allosteric modulators of glycoprotein hormone receptors, their effects on common signaling pathways in cells, their utility for clinical application as demonstrated in preclinical models

  7. A growth hormone receptor mutation impairs growth hormone autofeedback signaling in pituitary tumors.

    PubMed

    Asa, Sylvia L; Digiovanni, Rebecca; Jiang, Jing; Ward, Megan L; Loesch, Kimberly; Yamada, Shozo; Sano, Toshiaki; Yoshimoto, Katsuhiko; Frank, Stuart J; Ezzat, Shereen

    2007-08-01

    Pituitary tumors are a diverse group of neoplasms that are classified based on clinical manifestations, hormone excess, and histomorphologic features. Those that cause growth hormone (GH) excess and acromegaly are subdivided into morphologic variants that have not yet been shown to have pathogenetic significance or predictive value for therapy and outcome. Here, we identify a selective somatic histidine-to-leucine substitution in codon 49 of the extracellular domain of the GH receptor (GHR) in a morphologic subtype of human GH-producing pituitary tumors that is characterized by the presence of cytoskeletal aggresomes. This GHR mutation significantly impairs glycosylation-mediated receptor processing, maturation, ligand binding, and signaling. Pharmacologic GH antagonism recapitulates the morphologic phenotype of pituitary tumors from which this mutation was identified, inducing the formation of cytoskeletal keratin aggresomes. This novel GHR mutation provides evidence for impaired hormone autofeedback in the pathogenesis of these pituitary tumors. It explains the lack of responsiveness to somatostatin analogue therapy of this tumor type, in contrast to the exquisite sensitivity of tumors that lack aggresomes, and has therapeutic implications for the safety of GH antagonism as a therapeutic modality in acromegaly. PMID:17671221

  8. Aromatic Anchor at an Invariant Hormone-Receptor Interface

    PubMed Central

    Pandyarajan, Vijay; Smith, Brian J.; Phillips, Nelson B.; Whittaker, Linda; Cox, Gabriella P.; Wickramasinghe, Nalinda; Menting, John G.; Wan, Zhu-li; Whittaker, Jonathan; Ismail-Beigi, Faramarz; Lawrence, Michael C.; Weiss, Michael A.

    2014-01-01

    Crystallographic studies of insulin bound to fragments of the insulin receptor have recently defined the topography of the primary hormone-receptor interface. Here, we have investigated the role of PheB24, an invariant aromatic anchor at this interface and site of a human mutation causing diabetes mellitus. An extensive set of B24 substitutions has been constructed and tested for effects on receptor binding. Although aromaticity has long been considered a key requirement at this position, MetB24 was found to confer essentially native affinity and bioactivity. Molecular modeling suggests that this linear side chain can serve as an alternative hydrophobic anchor at the hormone-receptor interface. These findings motivated further substitution of PheB24 by cyclohexanylalanine (Cha), which contains a nonplanar aliphatic ring. Contrary to expectations, [ChaB24]insulin likewise exhibited high activity. Furthermore, its resistance to fibrillation and the rapid rate of hexamer disassembly, properties of potential therapeutic advantage, were enhanced. The crystal structure of the ChaB24 analog, determined as an R6 zinc-stabilized hexamer at a resolution of 1.5 Å, closely resembles that of wild-type insulin. The nonplanar aliphatic ring exhibits two chair conformations with partial occupancies, each recapitulating the role of PheB24 at the dimer interface. Together, these studies have defined structural requirements of an anchor residue within the B24-binding pocket of the insulin receptor; similar molecular principles are likely to pertain to insulin-related growth factors. Our results highlight in particular the utility of nonaromatic side chains as probes of the B24 pocket and suggest that the nonstandard Cha side chain may have therapeutic utility. PMID:25305014

  9. Identification of a new hormone-binding site on the surface of thyroid hormone receptor.

    PubMed

    Souza, P C T; Puhl, A C; Martínez, L; Aparício, R; Nascimento, A S; Figueira, A C M; Nguyen, P; Webb, P; Skaf, M S; Polikarpov, I

    2014-04-01

    Thyroid hormone receptors (TRs) are members of the nuclear receptor superfamily of ligand-activated transcription factors involved in cell differentiation, growth, and homeostasis. Although X-ray structures of many nuclear receptor ligand-binding domains (LBDs) reveal that the ligand binds within the hydrophobic core of the ligand-binding pocket, a few studies suggest the possibility of ligands binding to other sites. Here, we report a new x-ray crystallographic structure of TR-LBD that shows a second binding site for T3 and T4 located between H9, H10, and H11 of the TRα LBD surface. Statistical multiple sequence analysis, site-directed mutagenesis, and cell transactivation assays indicate that residues of the second binding site could be important for the TR function. We also conducted molecular dynamics simulations to investigate ligand mobility and ligand-protein interaction for T3 and T4 bound to this new TR surface-binding site. Extensive molecular dynamics simulations designed to compute ligand-protein dissociation constant indicate that the binding affinities to this surface site are of the order of the plasma and intracellular concentrations of the thyroid hormones, suggesting that ligands may bind to this new binding site under physiological conditions. Therefore, the second binding site could be useful as a new target site for drug design and could modulate selectively TR functions.

  10. Neither bST nor Growth Hormone Releasing Factor Alter Expression of Thyroid Hormone Receptors in Liver and Mammary Tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine, to specific nuclear receptors. It has been hypothesized that organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, target the action of thyroid hormones to the mammary...

  11. Effects of aging on pituitary and testicular luteinizing hormone-releasing hormone receptors in the rat.

    PubMed

    Limonta, P; Dondi, D; Maggi, R; Martini, L; Piva, F

    1988-01-01

    Aging exerts profound influences on the function of the hypothalamic-pituitary-testicular-axis. This work has been performed in order to verify whether, in male rats, the decreased secretion of LH and testosterone (T) occurring in old animals is reflected by modifications of luteinizing hormone-releasing hormone (LHRH) receptors at the level of the anterior pituitary and of the testes. To this purpose, the affinity constant (Ka) and the maximal binding capacity (Bmax) for the LHRH analog [D-Ser(tBu)6]des-Gly10-LHRH-N-ethylamide were evaluated, by means of a receptor binding assay, in membrane preparations derived from the anterior pituitary and testicular Leydig cells of male rats of 3 and 19 months of age. Serum levels of LH and T were measured by specific RIAs. The results obtained show that, in aged male rats, the concentration of pituitary LHRH receptors is significantly lower than that found in young animals. On the other hand, the concentration of LHRH binding sites is significantly increased on the membranes of Leydig cells of old rats. In no instance the Ka for the LHRH analog is significantly affected. Serum levels of LH and T are significantly lower in old than in young male rats. In conclusion, these results suggest that the reduced secretion of LH in old male rats may be linked, at least partially, to a decrease of the number of pituitary LHRH receptors. The impaired production of testosterone occurring in aged rats is accompanied by a significant increase of the number of testicular LHRH receptors, indicating that also the intratesticular mechanisms controlling testosterone release undergo significant alterations with aging.

  12. Molecular mechanisms of gonadotropin-releasing hormone receptor gene regulation.

    PubMed

    Norwitz, E R; Jeong, K H; Chin, W W

    1999-01-01

    GnRH plays a critical role in regulating mammalian reproductive development and function. At the level of the anterior pituitary, GnRH binds to the GnRH receptor (GnRHR) on the cell surface of pituitary gonadotropes. Here, it activates intracellular signal transduction pathways to effect both the synthesis and intermittent release of the gonadotropins LH and FSH. These hormones then enter the systemic circulation to regulate gonadal function, including steroid hormone synthesis and gametogenesis. The response of pituitary gonadotropes to GnRH correlates directly with the concentration of GnRHR on the cell surface, which is mediated, at least in part, at the level of gene expression. A number of endocrine, paracrine, and autocrine factors are known to regulate GnRHR gene expression. This article reviews in detail the role of the GnRHR in the hypothalamic-pituitary-gonadal axis and the factors mediating expression of this gene. A better understanding of the molecular mechanisms that regulate transcription of the GnRHR gene will further our knowledge about the role of this receptor in mammalian reproductive physiology in health and disease.

  13. Interaction of sodium molybdate with the thyroid hormone receptor.

    PubMed

    Faure, R; Dussault, J H

    1990-03-01

    The 3,5,3'-triiodothyronine (T3) binding activity of solubilized nuclear proteins from rat liver was decreased when molybdate (10 mM) was present in the incubation medium in the absence of thiol reagents. The equilibrium affinity constant was reduced by 40%. The rate of degradation of T3-receptor complexes at 37 degrees C remained unchanged, but when the extracts were further reincubated in the presence of beta-mercaptoethanol, molybdate had a protective effect after 5 h incubation at 37 degrees C. In contrast, the thyroxine (T4) binding activity was not affected by heating at 37 degrees C or by molybdate. Ion-exchange chromatography confirmed the existence of a molybdate-receptor interaction: the T3-receptor complexes shifted from elution at 0.22 to 0.20 M NaCl with the progressive appearance of a small leader peak, whereas the T4-receptor complexes eluted in a large and split peak (0.22-0.4 M NaCl). The destabilizing effect on T3 binding induced by exogenous dephosphorylation is more efficiently reversed by beta-mercaptoethanol when the extracts were pretreated by molybdate. In controls, the loss of saturable T3 binding activity was recovered by 50% at a 10 mM concentration of beta-mercaptoethanol, but in the presence of molybdate, the loss of T3 binding activity was recovered by 50% at a 5 mM concentration of beta-mercaptoethanol. This molybdate-receptor interaction is similar to that with nuclear receptor models in term of (i) stabilization of hormone binding, (ii) dependency on a thiol, and (iii) reversibility of the destabilizing effect by exogenous dephosphorylation.

  14. The neuroendocrine functions of the parathyroid hormone 2 receptor.

    PubMed

    Dobolyi, Arpád; Dimitrov, Eugene; Palkovits, Miklós; Usdin, Ted B

    2012-01-01

    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 two 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 neuroendocrine disorders.

  15. The Neuroendocrine Functions of the Parathyroid Hormone 2 Receptor

    PubMed Central

    Dobolyi, Arpád; Dimitrov, Eugene; Palkovits, Miklós; Usdin, Ted B.

    2012-01-01

    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 two 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 neuroendocrine disorders

  16. Follicle stimulating hormone receptor in mesenchymal stem cells integrates effects of glycoprotein reproductive hormones.

    PubMed

    Tourkova, Irina L; Witt, Michelle R; Li, La; Larrouture, Quitterie; Liu, Li; Luo, Jianhua; Robinson, Lisa J; Blair, Harry C

    2015-01-01

    Previously we reported that follicle stimulating hormone (FSH) affects bone degradation in human cells and in follicle stimulating hormone receptor (FSH-R) null mice. Here we describe a FSH-R knockout bone-formation phenotype. We used mesenchymal stem cells (MSCs), osteoblast precursors that express FSH-R, to determine whether FSH regulates bone formation. FSH stimulates MSC cell adhesion 1-3 h and proliferation at 24 h after addition. On the basis of phylogenetic and clinical precedents, we also examined effects of pregnant levels of human chorionic gonadotropin (hCG) on MSCs. We found effects similar to those of FSH, and RNAi knockdown of FSH-R abrogated both FSH and hCG effects on MSCs. In contrast to effects on MSCs, neither FSH nor hCG had significant effects on osteoblast maturation. Also in MSCs, short-term treatment by FSH and hCG altered signaling pathways for proliferation, including Erk1/2 phosphorylation. Our results show augmentation of MSC proliferation by either FSH at menopausal levels or hCG at normal pregnant levels. We conclude that FSH-R participates in regulation of MSC precursor pools in response to either FSH or hCG, integrating the effects of these two glycoprotein hormones.

  17. Hepatic receptors for homologous growth hormone in the eel

    SciTech Connect

    Hirano, T. )

    1991-03-01

    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.

  18. Immunoreactivity for sex steroid hormone receptors in pulmonary hamartomas.

    PubMed

    Pelosi, Giuseppe; Rosai, Juan; Viale, Giuseppe

    2006-07-01

    Sex steroid hormone [ie, estrogen (ER), progesterone (PgR), and androgen (AR)] receptors have been identified previously in normal salivary glands and, more variably, in salivary gland and salivary gland-type tumors. No data are available, however, on their expression in pulmonary hamartoma, a benign biphasic tumor consisting of reactive epithelial cells and neoplastic fibromyxoid stroma, cartilage and fat, which shares some morphologic, immunophenotypic, and genotypic features to pleomorphic adenoma of major salivary glands. Thirty pulmonary hamartomas (15 in male patients and 15 in age-matched female patients), were evaluated for ER, PgR, and AR immunoreactivity, and also for mesenchymal, epithelial, and myoepithelial markers, in the fibromyxoid, epithelial, and chondroid components. ER immunoreactivity was encountered in 90% of hamartomas, PgRs in 90%, and ARs in 53% (P<0.001), but not in normal lung tissues. ARs were confined to males (P<0.001), with a marginal prevalence in the fibromyxoid component (P=0.067). PgRs and ERs were instead present in both sex, with the former being restricted to the fibromyxoid stromal component (P<0.001) and the latter preferentially located in epithelial cells (P=0.107). In most cases, fibromyxoid stroma and spindle cells surrounding the chondroid foci displayed simultaneous immunoreactivity for ERs, PgRs, and ARs, along with immunoreactivity for vimentin, S-100 protein, glial fibrillary acid protein, smooth muscle actin, and calponin but lack of staining for cytokeratins. This profile is consistent with an incomplete myoepithelial differentiation of the receptor-expressing mesenchymal cells. In conclusion, sex steroid hormone receptor expression is a nonrandom event in pulmonary hamartoma, and may be related to the development and growth of this tumor.

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

    PubMed

    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.

  20. Targeting Thyroid Hormone Receptor Beta in Triple Negative Breast Cancer

    PubMed Central

    Gu, Guowei; Gelsomino, Luca; Covington, Kyle R.; Beyer, Amanda R.; Wang, John; Rechoum, Yassine; Huffman, Kenneth; Carstens, Ryan; Ando, Sebastiano; Fuqua, Suzanne A.W.

    2015-01-01

    Purpose Discover novel nuclear receptor targets in triple negative breast cancer Methods Expression microarray, western blot, qRT-PCR, MTT growth assay, soft agar anchorage-independent growth assay, TRE reporter transactivation assay, statistical analysis. Results We performed microarray analysis using 227 triple negative breast tumors, and clustered the tumors into five groups according to their nuclear receptor expression. Thyroid hormone receptor beta (TRβ) was one of the most differentially expressed nuclear receptors in group 5 compared to other groups. TRβ low expressing patients were associated with poor outcome. We evaluated the role of TRβ in triple negative breast cancer cell lines representing group 5 tumors. Knockdown of TRβ increased soft agar colony and reduced sensitivity to docetaxel and doxorubicin treatment. Docetaxel or doxorubicin long-term cultured cell lines also expressed decreased TRβ protein. Microarray analysis revealed cAMP/PKA signaling was the only KEGG pathways upregulated in TRβ knockdown cells. Inhibitors of cAMP or PKA, in combination with doxorubicin further enhanced cell apoptosis and restored sensitivity to chemotherapy. TRβ-specific agonists enhanced TRβ expression, and further sensitized cells to both docetaxel and doxorubicin. Sensitization was mediated by increased apoptosis with elevated cleaved PARP and caspase 3. Conclusions TRβ represents a novel nuclear receptor target in triple negative breast cancer; low TRβ levels were associated with enhanced resistance to both docetaxel and doxorubicin treatment. TRβ-specific agonists enhance chemosensitivity to these two agents. Mechanistically enhanced cAMP/PKA signaling was associated with TRβ’s effects on response to chemotherapy. PMID:25820519

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

    SciTech Connect

    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.

  2. Direct and in vitro observation of growth hormone receptor molecules in A549 human lung epithelial cells by nanodiamond labeling

    NASA Astrophysics Data System (ADS)

    Cheng, C.-Y.; Perevedentseva, E.; Tu, J.-S.; Chung, P.-H.; Cheng, C.-L.; Liu, K.-K.; Chao, J.-I.; Chen, P.-H.; Chang, C.-C.

    2007-04-01

    This letter presents direct observation of growth hormone receptor in one single cancer cell using nanodiamond-growth hormone complex as a specific probe. The interaction of surface growth hormone receptor of A549 human lung epithelial cells with growth hormone was observed using nanodiamond's unique spectroscopic signal via confocal Raman mapping. The growth hormone molecules were covalent conjugated to 100nm diameter carboxylated nanodiamonds, which can be recognized specifically by the growth hormone receptors of A549 cell. The Raman spectroscopic signal of diamond provides direct and in vitro observation of growth hormone receptors in physiology condition in a single cell level.

  3. Xenopus laevis alpha and beta thyroid hormone receptors.

    PubMed Central

    Yaoita, Y; Shi, Y B; Brown, D D

    1990-01-01

    The Xenopus laevis genome encodes two genes for the alpha (TR alpha) and two genes for the beta (TR beta) thyroid hormone receptors. The two TR alpha genes closely resemble their rat, human, and chicken counterparts. No alternatively spliced TR alpha cDNA clones were found in the 5' untranslated region (5' UTR). In contrast, complex alternative splicing of TR beta mRNA occurs within the 5' UTR as well as possible alternative transcriptional start sites. As many as eight exons encoding mainly the 5' UTR are alternatively spliced, giving rise to at least two amino termini for each of the two TR beta proteins. The 5' UTR of transcripts from both TR alpha and TR beta genes contain multiple AUG sequences with short open reading frames suggesting translational control mechanisms might play a role in expression of TR genes. Images PMID:2402492

  4. Role of the Extracellular and Intracellular Loops of Follicle-Stimulating Hormone Receptor in Its Function.

    PubMed

    Banerjee, Antara A; Mahale, Smita D

    2015-01-01

    Follicle-stimulating hormone receptor (FSHR) is a leucine-rich repeat containing class A G-protein coupled receptor belonging to the subfamily of glycoprotein hormone receptors (GPHRs), which includes luteinizing hormone/choriogonadotropin receptor (LH/CGR) and thyroid-stimulating hormone receptor. Its cognate ligand, follicle-stimulating hormone binds to, and activates FSHR expressed on the surface of granulosa cells of the ovary, in females, and Sertoli cells of the testis, in males, to bring about folliculogenesis and spermatogenesis, respectively. FSHR contains a large extracellular domain (ECD) consisting of leucine-rich repeats at the N-terminal end and a hinge region at the C-terminus that connects the ECD to the membrane spanning transmembrane domain (TMD). The TMD consists of seven α-helices that are connected to each other by means of three extracellular loops (ELs) and three intracellular loops (ILs) and ends in a short-cytoplasmic tail. It is well established that the ECD is the primary hormone binding domain, whereas the TMD is the signal transducing domain. However, several studies on the ELs and ILs employing site directed mutagenesis, generation of chimeric receptors and in vitro characterization of naturally occurring mutations have proven their indispensable role in FSHR function. Their role in every phase of the life cycle of the receptor like post translational modifications, cell surface trafficking, hormone binding, activation of downstream signaling, receptor phosphorylation, hormone-receptor internalization, and recycling of hormone-receptor complex have been documented. Mutations in the loops causing dysregulation of these processes lead to pathophysiological conditions. In other GPHRs as well, the loops have been convincingly shown to contribute to various aspects of receptor function. This review article attempts to summarize the extensive contributions of FSHR loops and C-terminal tail to its function. PMID:26236283

  5. Association of the genetic variants of luteinizing hormone, luteinizing hormone receptor and polycystic ovary syndrome

    PubMed Central

    2012-01-01

    Background High circulating luteinizing hormone (LH) level is a typical biochemical feature of polycystic ovary syndrome (PCOS) whose pathophysiology is still unclear. Certain mutations of LH and LH receptor (LHR) may lead to changes in bioactivity of these hormones. The aim of this study was determine the role of the LH and LHR polymorphisms in the pathogenesis of PCOS using a genetic approach. Methods 315 PCOS women and 212 controls were screened for the gene variants of LH G1052A and LHR rs61996318 polymorphisms by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Results PCOS patients had significantly more A allele frequency of LH G1052A mutations than controls (p=0.001). Within PCOS group, carriers of LH 1052A allele had lower LH (p=0.05) and higher fasting glucose levels (p=0.04). No subjects were identified with LHR rs61996318 polymorphisms. A new LHR single nucleotide polymorphism (SNP) was found without clear association with PCOS. Conclusions Results suggested LH G1052A mutation might influence PCOS susceptibility and phenotypes. PMID:22546001

  6. Characterization of a thyroid hormone receptor expressed in human kidney and other tissues

    SciTech Connect

    Nakai, A.; Seino, S.; Sakurai, A.; Szilak, I.; Bell, G.I.; DeGroot, L.J.

    1988-04-01

    A cDNA encoding a specific form of thyroid hormone receptor expressed in human liver, kidney, placenta, and brain was isolated from a human kidney library. Identical clones were found in human placenta and HepG2 cDNA libraries. The cDNA encodes a 490-amino acid protein. When expressed and translated in vitro, the protein products binds triiodothyronine with K/sub a/ of 2.3 /times/ 10/sup 9/ M/sup /minus/1/. This protein, designated human thyroid hormone receptor type ..cap alpha..2 (hTR..cap alpha..2), has the same domain structure as other members of the v-erbA-related superfamily of receptor genes. It is similar to thyroid hormone receptor type ..cap alpha.. described in chicken and rat and less similar to human thyroid hormone receptor type ..beta.. (formerly referred to as c-erbA..beta..) from placenta. However, it is distinguished from these receptors by an extension of the C-terminal hormone binding domain making it 80 amino acids longer than rat thyroid hormone receptor type ..cap alpha..1. Different sizes of mRNA found in liver and kidney suggest that there may be tissue-specific processing of the primary transcript of this gene. Identification of human thyroid hormone receptor type ..cap alpha..2 indicates that two or more forms of thyroid hormone receptor exist in human tissues and may explain the normal variation in thyroid hormone responsiveness of various organs and the selective tissue abnormalities found in the thyroid hormone resistance syndromes.

  7. The role of nuclear hormone receptors in cutaneous wound repair

    PubMed Central

    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. PMID:25529612

  8. Flow cytometric monitoring of hormone receptor expression in human solid tumors

    NASA Astrophysics Data System (ADS)

    Krishan, Awtar

    2002-05-01

    Hormone receptor expression in human breast and prostate tumors is of diagnostic and therapeutic importance. With the availability of anti-estrogen, androgen and progesterone antibodies, immunohistochemistry has become a standard tool for determination of receptor expression in human tumor biopsies. However, this method is dependent on examination of a small number of cells under a microscope and the data obtained in most cases is not quantitative. As most of the commercially used anti-hormone antibodies have nuclear specificity, we have developed methods for isolation and antigen unmasking of nuclei from formalin fixed/paraffin embedded archival human tumors. After immunostaining with the antibodies and propidium iodide (for DNA content and cell cycle analysis), nuclei are analyzed by multiparametric laser flow cytometry for hormone receptor expression, DNA content, aneuploidy and cell cycle determination. These multiparametric methods are especially important for retrospective studies seeking to correlate hormone receptor expression with clinical response to anti-hormonal therapy of human breast and prostate tumors.

  9. Activation of erythropoietin receptor in the absence of hormone by a peptide that binds to a domain different from the hormone binding site

    PubMed Central

    Naranda, Tatjana; Wong, Kenneth; Kaufman, R. Ilene; Goldstein, Avram; Olsson, Lennart

    1999-01-01

    Applying a homology search method previously described, we identified a sequence in the extracellular dimerization site of the erythropoietin receptor, distant from the hormone binding site. A peptide identical to that sequence was synthesized. Remarkably, it activated receptor signaling in the absence of erythropoietin. Neither the peptide nor the hormone altered the affinity of the other for the receptor; thus, the peptide does not bind to the hormone binding site. The combined activation of signal transduction by hormone and peptide was strongly synergistic. In mice, the peptide acted like the hormone, protecting against the decrease in hematocrit caused by carboplatin. PMID:10377456

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

    PubMed Central

    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

  11. Growth hormone receptor polymorphism and growth hormone therapy response in children: a Bayesian meta-analysis.

    PubMed

    Renehan, Andrew G; Solomon, Mattea; Zwahlen, Marcel; Morjaria, Reena; Whatmore, Andrew; Audí, Laura; Binder, Gerhard; Blum, Werner; Bougnères, Pierre; Santos, Christine Dos; Carrascosa, Antonio; Hokken-Koelega, Anita; Jorge, Alexander; Mullis, Primus E; Tauber, Maïthé; Patel, Leena; Clayton, Peter E

    2012-05-01

    Recombinant human growth hormone (rhGH) therapy is used in the long-term treatment of children with growth disorders, but there is considerable treatment response variability. The exon 3-deleted growth hormone receptor polymorphism (GHR(d3)) may account for some of this variability. The authors performed a systematic review (to April 2011), including investigator-only data, to quantify the effects of the GHR(fl-d3) and GHR(d3-d3) genotypes on rhGH therapy response and used a recently established Bayesian inheritance model-free approach to meta-analyze the data. The primary outcome was the 1-year change-in-height standard-deviation score for the 2 genotypes. Eighteen data sets from 12 studies (1,527 children) were included. After several prior assumptions were tested, the most appropriate inheritance model was codominant (posterior probability = 0.93). Compared with noncarriers, carriers had median differences in 1-year change-in-height standard-deviation score of 0.09 (95% credible interval (CrI): 0.01, 0.17) for GHR(fl-d3) and of 0.14 (95% CrI: 0.02, 0.26) for GHR(d3-d3). However, the between-study standard deviation of 0.18 (95% CrI: 0.10, 0.33) was considerable. The authors tested by meta-regression for potential modifiers and found no substantial influence. They conclude that 1) the GHR(d3) polymorphism inheritance is codominant, contrasting with previous reports; 2) GHR(d3) genotypes account for modest increases in rhGH effects in children; and 3) considerable unexplained variability in responsiveness remains.

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

    PubMed Central

    Muñoz, A; Zenke, M; Gehring, U; Sap, J; Beug, H; Vennström, B

    1988-01-01

    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 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 P75gag-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-independent activity of P75gag-v-erbA provided a selective advantage to the avian erythroblastosis virus during the original selection for a highly oncogenic strain of the virus. Images PMID:3359993

  13. Role of the Extracellular and Intracellular Loops of Follicle-Stimulating Hormone Receptor in Its Function

    PubMed Central

    Banerjee, Antara A.; Mahale, Smita D.

    2015-01-01

    Follicle-stimulating hormone receptor (FSHR) is a leucine-rich repeat containing class A G-protein coupled receptor belonging to the subfamily of glycoprotein hormone receptors (GPHRs), which includes luteinizing hormone/choriogonadotropin receptor (LH/CGR) and thyroid-stimulating hormone receptor. Its cognate ligand, follicle-stimulating hormone binds to, and activates FSHR expressed on the surface of granulosa cells of the ovary, in females, and Sertoli cells of the testis, in males, to bring about folliculogenesis and spermatogenesis, respectively. FSHR contains a large extracellular domain (ECD) consisting of leucine-rich repeats at the N-terminal end and a hinge region at the C-terminus that connects the ECD to the membrane spanning transmembrane domain (TMD). The TMD consists of seven α-helices that are connected to each other by means of three extracellular loops (ELs) and three intracellular loops (ILs) and ends in a short-cytoplasmic tail. It is well established that the ECD is the primary hormone binding domain, whereas the TMD is the signal transducing domain. However, several studies on the ELs and ILs employing site directed mutagenesis, generation of chimeric receptors and in vitro characterization of naturally occurring mutations have proven their indispensable role in FSHR function. Their role in every phase of the life cycle of the receptor like post translational modifications, cell surface trafficking, hormone binding, activation of downstream signaling, receptor phosphorylation, hormone–receptor internalization, and recycling of hormone–receptor complex have been documented. Mutations in the loops causing dysregulation of these processes lead to pathophysiological conditions. In other GPHRs as well, the loops have been convincingly shown to contribute to various aspects of receptor function. This review article attempts to summarize the extensive contributions of FSHR loops and C-terminal tail to its function. PMID:26236283

  14. Identification of thyroid hormone receptor homologs in the fluke Opisthorchis felineus (Platyhelminthes).

    PubMed

    Pakharukova, Maria Y; Ershov, Nikita I; Vorontsova, Elena V; Shilov, Alexander G; Merkulova, Tatyana I; Mordvinov, Viatcheslav A

    2014-01-01

    The liver fluke, Opisthorchis felineus of the Opisthorchiidae family, is a well-known causative agent of opisthorchiasis in Russia and Europe. The aim of this work was to identify genes encoding thyroid hormone receptors in O. felineus, and to analyze the expression of possible target genes in response to treatment with exogenous thyroid hormones. We identified two genes encoding thyroid hormone receptors in the O. felineus genome, THRA and THRB. The genes were differentially expressed through the life cycle. The maximal level of mRNA expression of THRA1 and THRB was observed in adult worms. Treatment of the worms with triiodothyronine and thyroxine resulted in an increase in glucose 6-phosphatase mRNA expression and a decrease in malate dehydrogenase mRNA expression, potential gene targets of thyroid hormones. These data indicate that thyroid hormone receptors may perform essential roles in physiological processes in adult O. felineus.

  15. Growth hormone receptor/binding protein: Physiology and function

    SciTech Connect

    Herington, A.C.; Ymer, S.I.; Stevenson, J.L.; Roupas, P.

    1994-12-31

    Soluble truncated forms of the growth hormone receptor (GHR) are present in the circulation of many species and are also produced by many tissues/cell types. The major high-affinity forms of these GH-binding proteins (GHBP) are derived by alternative splicing of GHR mRNA in rodents, but probably by proteolytic cleavage in other species. Questions still remain with respect to the origins, native molecular forms(s), physiology, and function of the GHBPs, however. The observation that GH induces dimerization of the soluble GHBP and a membrane GHR, and that dimerization of GHR appears to be critical for GH bioactivity suggests that the presentation of GH to target cells, in an unbound form or as a monomeric or dimeric complex with GHBP, may have significant implications for the ability of GH to activate specific postreceptor signaling pathways (tyrosine kinase, protein kinase C, G-protein pathways) known to be utilized by GH for its diverse biological effects. This minireview addresses some of these aspects and highlights several new questions which have arisen as a result of recent advances in our understanding of the structure, function, and signaling mechanisms of the membrane bound GHR. 43 refs.

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

    SciTech Connect

    Martinez, Elisabeth D.; Pattabiraman, Nagarajan; Danielsen, Mark . E-mail: dan@bc.georgetown.edu

    2005-08-15

    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.

  17. NMDA receptors in the medial zona incerta stimulate luteinizing hormone and prolactin release.

    PubMed

    Bregonzio, Claudia; Moreno, Griselda N; Cabrera, Ricardo J; Donoso, Alfredo O

    2004-06-01

    1. The aim of the present work is to demonstrate the interaction between the glutamatergic/NMDA and dopaminergic systems in the medial zona incerta on the control of luteinizing hormone and prolactin secretion and the influence of reproductive hormones. 2. Proestrus and ovariectomized rats were primed with estrogen and progesterone to induce high or low levels of luteinizing hormone and prolactin. 2-Amino-7-phosphonoheptanoic acid, an NMDA receptor antagonist, and dopamine were injected in the medial zona incerta. Blood samples were withdrawn every hour between 1,600 and 2,000 hours or 2,200 hours via intracardiac catheter from conscious rats. Additional groups of animals injected with the NMDA receptor antagonist were killed 1 or 4 h after injection. Dopamine and its metabolite 3,4-dihydroxyphenylacetic acid were measured in different hypothalamic regions. 3. 2-Amino-7-phosphonoheptanoic acid blocked the ovulatory luteinizing hormone surge in proestrus rats. 2-Amino-7-phosphonoheptanoic acid also blocked the increase in luteinizing hormone induced by ovarian hormones in ovariectomized rats, an effect that was partially reversed by dopamine injection. Conversely, the increased release of luteinizing hormone and prolactin induced by dopamine was prevented by 2-amino-7-phosphonoheptanoic acid. We found that the NMDA antagonist injection decreased the dopaminergic activity--as evaluated by the 3,4-dihydroxyphenylacetic acid/dopamine ratio--in the medio basal hypothalamus and increased in the preoptic area. 4. Our results show an stimulatory role of NMDA receptors on the ovulatory luteinizing hormone release and on luteinizing hormone release induced by sexual hormones and demonstrate that the stimulatory effect of dopamine on luteinizing hormone and prolactin is mediated by the NMDA receptors. These results suggest a close interaction between the glutamatergic and dopaminergic incertohypothalamic systems on the control of luteinizing hormone and prolactin release

  18. Fluoride Exposure, Follicle Stimulating Hormone Receptor Gene Polymorphism and Hypothalamus-pituitary-ovarian Axis Hormones in Chinese Women.

    PubMed

    Zhao, Ming Xu; Zhou, Guo Yu; Zhu, Jing Yuan; Gong, Biao; Hou, Jia Xiang; Zhou, Tong; Duan, Li Ju; Ding, Zhong; Cui, Liu Xin; Ba, Yue

    2015-09-01

    The effects of fluoride exposure on the functions of reproductive and endocrine systems have attracted widespread attention in academic circle nowadays. However, it is unclear whether the gene-environment interaction may modify the secretion and activity of hypothalamus-pituitary- ovarian (HPO) axis hormones. Thus, the aim of this study was to explore the influence of fluoride exposure and follicle stimulating hormone receptor (FSHR) gene polymorphism on reproductive hormones in Chinese women. A cross sectional study was conducted in seven villages of Henan Province, China during 2010-2011. A total of 679 women aged 18-48 years were recruited through cluster sampling and divided into three groups, i.e. endemic fluorosis group (EFG), defluoridation project group (DFPG), and control group (CG) based on the local fluoride concentration in drinking water. The serum levels of gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were determined respectively and the FSHR polymorphism was detected by real time PCR assay. The results provided the preliminary evidence indicating the gene-environment interaction on HPO axis hormones in women.

  19. Fluoride Exposure, Follicle Stimulating Hormone Receptor Gene Polymorphism and Hypothalamus-pituitary-ovarian Axis Hormones in Chinese Women.

    PubMed

    Zhao, Ming Xu; Zhou, Guo Yu; Zhu, Jing Yuan; Gong, Biao; Hou, Jia Xiang; Zhou, Tong; Duan, Li Ju; Ding, Zhong; Cui, Liu Xin; Ba, Yue

    2015-09-01

    The effects of fluoride exposure on the functions of reproductive and endocrine systems have attracted widespread attention in academic circle nowadays. However, it is unclear whether the gene-environment interaction may modify the secretion and activity of hypothalamus-pituitary- ovarian (HPO) axis hormones. Thus, the aim of this study was to explore the influence of fluoride exposure and follicle stimulating hormone receptor (FSHR) gene polymorphism on reproductive hormones in Chinese women. A cross sectional study was conducted in seven villages of Henan Province, China during 2010-2011. A total of 679 women aged 18-48 years were recruited through cluster sampling and divided into three groups, i.e. endemic fluorosis group (EFG), defluoridation project group (DFPG), and control group (CG) based on the local fluoride concentration in drinking water. The serum levels of gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were determined respectively and the FSHR polymorphism was detected by real time PCR assay. The results provided the preliminary evidence indicating the gene-environment interaction on HPO axis hormones in women. PMID:26464260

  20. (-) Arctigenin and (+) pinoresinol are antagonists of the human thyroid hormone receptor β.

    PubMed

    Ogungbe, Ifedayo Victor; Crouch, Rebecca A; Demeritte, Teresa

    2014-11-24

    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

  1. (-) Arctigenin and (+) pinoresinol are antagonists of the human thyroid hormone receptor β.

    PubMed

    Ogungbe, Ifedayo Victor; Crouch, Rebecca A; Demeritte, Teresa

    2014-11-24

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  3. The DEK Oncogene Is a Target of Steroid Hormone Receptor Signaling in Breast Cancer

    PubMed Central

    Privette Vinnedge, Lisa M.; Ho, Shuk-Mei; Wikenheiser-Brokamp, Kathryn A.; Wells, Susanne I.

    2012-01-01

    Expression of estrogen and progesterone hormone receptors indicates a favorable prognosis due to the successful use of hormonal therapies such as tamoxifen and aromatase inhibitors. Unfortunately, 15–20% of patients will experience breast cancer recurrence despite continued use of tamoxifen. Drug resistance to hormonal therapies is of great clinical concern so it is imperative to identify novel molecular factors that contribute to tumorigenesis in hormone receptor positive cancers and/or mediate drug sensitivity. The hope is that targeted therapies, in combination with hormonal therapies, will improve survival and prevent recurrence. We have previously shown that the DEK oncogene, which is a chromatin remodeling protein, supports breast cancer cell proliferation, invasion and the maintenance of the breast cancer stem cell population. In this report, we demonstrate that DEK expression is associated with positive hormone receptor status in primary breast cancers and is up-regulated in vitro following exposure to the hormones estrogen, progesterone, and androgen. Chromatin immunoprecipitation experiments identify DEK as a novel estrogen receptor α (ERα) target gene whose expression promotes estrogen-induced proliferation. Finally, we report for the first time that DEK depletion enhances tamoxifen-induced cell death in ER+ breast cancer cell lines. Together, our data suggest that DEK promotes the pathogenesis of ER+ breast cancer and that the targeted inhibition of DEK may enhance the efficacy of conventional hormone therapies. PMID:23071688

  4. Molecular cloning of the gene encoding the mouse parathyroid hormone/parathyroid hormone-related peptide receptor.

    PubMed Central

    McCuaig, K A; Clarke, J C; White, J H

    1994-01-01

    The parathyroid hormone/parathyroid hormone-related peptide receptor (PTHR) is a G-protein-coupled receptor containing seven predicted transmembrane domains. We have isolated and characterized recombinant bacteriophage lambda EMBL3 genomic clones containing the mouse PTHR gene, including 10 kilobases of the promoter region. The gene spans > 32 kilobases and is divided into 15 exons, 8 of which contain the transmembrane domains. The PTHR exons containing the predicted membrane-spanning domains are heterogeneous in length and three of the exon-intron boundaries fall within putative transmembrane sequences, suggesting that the exons did not arise from duplication events. This arrangement is closely related to that of the growth hormone releasing factor receptor gene, particularly in the transmembrane region, providing strong evidence that the two genes evolved from a common precursor. Transcription is initiated principally at a series of sites over a 15-base-pair region. The proximal promoter region is highly (G+C)-rich and lacks an apparent TATA box or initiator element homologies but does contain CCGCCC motifs. The presumptive amino acid sequence of the encoded receptor is 99%, 91%, and 76% identical to those of the rat, human, and opossum receptors, respectively. There is no consensus polyadenylation signal in the 3' untranslated region. The poly(A) tail of the PTHR transcript begins 32 bases downstream of a 35-base-long A-rich sequence, suggesting that this region directs polyadenylylation. Images PMID:8197183

  5. Lack of hormone binding in COS-7 cells expressing a mutated growth hormone receptor found in Laron dwarfism.

    PubMed Central

    Edery, M; Rozakis-Adcock, M; Goujon, L; Finidori, J; Lévi-Meyrueis, C; Paly, J; Djiane, J; Postel-Vinay, M C; Kelly, P A

    1993-01-01

    A single point mutation in the growth hormone (GH) receptor gene generating a Phe-->Ser substitution in the extracellular binding domain of the receptor has been identified in one family with Laron type dwarfism. The mutation was introduced by site-directed mutagenesis into cDNAs encoding the full-length rabbit GH receptor and the extracellular domain or binding protein (BP) of the human and rabbit GH receptor, and also in cDNAs encoding the full length and the extracellular domain of the related rabbit prolactin (PRL) receptor. All constructs were transiently expressed in COS-7 cells. Both wild type and mutant full-length rabbit GH and PRL receptors, as well as GH and prolactin BPs (wild type and mutant), were detected by Western blot in cell membranes and concentrated culture media, respectively. Immunofluorescence studies showed that wild type and mutant full-length GH receptors had the same cell surface and intracellular distribution and were expressed with comparable intensities. In contrast, all mutant forms (full-length receptors or BPs), completely lost their modify the synthesis ligand. These results clearly demonstrate that this point mutation (patients with Laron syndrome) does not modify the synthesis or the intracellular pathway of receptor proteins, but rather abolishes ability of the receptor or BP to bind GH and is thus responsible for the extreme GH resistance in these patients. Images PMID:8450064

  6. Bioluminescent Ligand-Receptor Binding Assays for Protein or Peptide Hormones.

    PubMed

    Liu, Ya-Li; Guo, Zhan-Yun

    2016-01-01

    Bioluminescence has been widely used in biomedical research due to its high sensitivity, low background, and broad linear range. In recent studies, we applied bioluminescence to ligand-receptor binding assays for some protein or peptide hormones based on a newly developed small monomeric Nanoluciferase (NanoLuc) reporter that has the so far brightest bioluminescence. The conventional ligand-receptor binding assays rely on radioligands that have drawbacks, such as radioactive hazards and short shelf lives. In contrast, the novel bioluminescent binding assays use the NanoLuc-based protein or peptide tracers that are safe, stable, and ultrasensitive. Thus, the novel bioluminescent ligand-receptor binding assay would be applied to more and more protein or peptide hormones for ligand-receptor interaction studies in future. In the present article, we provided detailed protocols for setting up the novel bioluminescent ligand-receptor binding assays using two representative protein hormones as examples. PMID:27424896

  7. Genome-Wide Binding Patterns of Thyroid Hormone Receptor Beta

    PubMed Central

    Ayers, Stephen; Switnicki, Michal Piotr; Angajala, Anusha; Lammel, Jan; Arumanayagam, Anithachristy S.; Webb, Paul

    2014-01-01

    Thyroid hormone (TH) receptors (TRs) play central roles in metabolism and are major targets for pharmaceutical intervention. Presently, however, there is limited information about genome wide localizations of TR binding sites. Thus, complexities of TR genomic distribution and links between TRβ binding events and gene regulation are not fully appreciated. Here, we employ a BioChIP approach to capture TR genome-wide binding events in a liver cell line (HepG2). Like other NRs, TRβ appears widely distributed throughout the genome. Nevertheless, there is striking enrichment of TRβ binding sites immediately 5′ and 3′ of transcribed genes and TRβ can be detected near 50% of T3 induced genes. In contrast, no significant enrichment of TRβ is seen at negatively regulated genes or genes that respond to unliganded TRs in this system. Canonical TRE half-sites are present in more than 90% of TRβ peaks and classical TREs are also greatly enriched, but individual TRE organization appears highly variable with diverse half-site orientation and spacing. There is also significant enrichment of binding sites for TR associated transcription factors, including AP-1 and CTCF, near TR peaks. We conclude that T3-dependent gene induction commonly involves proximal TRβ binding events but that far-distant binding events are needed for T3 induction of some genes and that distinct, indirect, mechanisms are often at play in negative regulation and unliganded TR actions. Better understanding of genomic context of TR binding sites will help us determine why TR regulates genes in different ways and determine possibilities for selective modulation of TR action. PMID:24558356

  8. Recessive resistance to thyroid hormone in mice lacking thyroid hormone receptor beta: evidence for tissue-specific modulation of receptor function.

    PubMed Central

    Forrest, D; Hanebuth, E; Smeyne, R J; Everds, N; Stewart, C L; Wehner, J M; Curran, T

    1996-01-01

    The diverse functions of thyroid hormone (T3) are presumed to be mediated by two genes encoding the related receptors, TRalpha and TRbeta. However, the in vivo functions of TRalpha and TRbeta are undefined. Here, we report that targeted inactivation of the mouse TRbeta gene results in goitre and elevated levels of thyroid hormone. Also, thyroid-stimulating hormone (TSH), which is released by pituitary thyrotropes and which is normally suppressed by increased levels of thyroid hormone, was present at elevated levels in homozygous mutant (Thrb-/-) mice. These findings suggest a unique role for TRbeta that cannot be substituted by TRalpha in the T3-dependent feedback regulation of TSH transcription. Thrb-/- mice provide a recessive model for the human syndrome of resistance to thyroid hormone (RTH) that exhibits a similar endocrine disorder but which is typically caused by dominant TRbeta mutants that are transcriptional inhibitors. It is unknown whether TRalpha, TRbeta or other receptors are targets for inhibition in dominant RTH; however, the analysis of Thrb-/- mice suggests that antagonism of TRbeta-mediated pathways underlies the disorder of the pituitary-thyroid axis. Interestingly, in the brain, the absence of TRbeta may not mimic the defects often associated with dominant RTH, since no overt behavioural or neuroanatomical abnormalities were detected in Thrb-/- mice. These data define in vivo functions for TRbeta and indicate that specificity in T3 signalling is conferred by distinct receptor genes. Images PMID:8670802

  9. Serotonin directly stimulates luteinizing hormone-releasing hormone release from GT1 cells via 5-HT7 receptors.

    PubMed

    Héry, M; François-Bellan, A M; Héry, F; Deprez, P; Becquet, D

    1997-10-01

    Luteinizing hormone-releasing hormone (LHRH release, which serves as the primary drive to the hypothalamic-pituitary gonadal axis, is controlled by many neuromediators. Serotonin has been implicated in this regulation. However, it is unclear whether the central effect of serotonin on LHRH secretion is exerted directly on LHRH neurosecretory neurons or indirectly via multisynaptic pathways. The present studies were undertaken in order to examine whether LHRH secretion from immortalized LHRH cell lines is directly regulated by serotonin and, if so, to identify the receptor subtype involved. 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A/7 receptor agonist, stimulated LHRH release from GT1-1 cells. This effect was blocked by ritanserin, a 5-HT2/7 receptor antagonist, but not by SDZ-216-525, a 5-HT1A antagonist. Basal LHRH release was not affected by the 5-HT2 agonist DOI. Reverse transcription and polymerase chain reaction technique (RT-PCR) was used in order to identify 5-HT1A and 5-HT7 receptor mRNA in immortalized LHRH cell lines. GT1-1 cells express mRNA for the 5-HT7, but not the 5-HT1A receptor subtypes. These results demonstrate a direct stimulatory effect of serotonin on LHRH release via 5-HT7 receptor.

  10. Pentadecapeptide BPC 157 enhances the growth hormone receptor expression in tendon fibroblasts.

    PubMed

    Chang, Chung-Hsun; Tsai, Wen-Chung; Hsu, Ya-Hui; Pang, Jong-Hwei Su

    2014-01-01

    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. PMID:25415472

  11. Hormone Receptors in Serous Ovarian Carcinoma: Prognosis, Pathogenesis, and Treatment Considerations

    PubMed Central

    Voutsadakis, Ioannis A.

    2016-01-01

    A few breakthroughs have been accomplished for the treatment of ovarian cancer, the most deadly gynecologic carcinoma, in the current era of targeted oncologic treatment. The estrogen receptor was the first target of such treatments with the introduction of tamoxifen four decades ago in breast cancer therapeutics. Attempts to duplicate the success of hormonal therapies in ovarian cancer met with mixed results, which may be due to an inferior degree of hormone dependency in this cancer. Alternatively, this may be due to the failure to clearly identify the subsets of ovarian cancer with hormone sensitivity. This article reviews the expression of hormone receptors by ovarian cancer cells, the prognostic value of these expressions, and their predictive capacity for response to hormonal agents. The possible ways ahead are briefly discussed. PMID:27053923

  12. Porcine mononuclear leukocyte nuclear thyroid hormone receptors: Effects of cold exposure on receptor kinetics

    SciTech Connect

    D'Alesandro, M.; Reed, L.; Malik, M.; Quesada, M.; Hesslink, R.; Castro, S.; Homer, L.; Young, B. Univ. of Alberta, Edmonton )

    1991-03-11

    Changes in kinetic characteristics of the triiodothyronine (T{sub 3}) receptor may be a mechanism involved in the thermoregulatory action of T{sub 3} at the nuclear level. To study this, the authors analyzed changes in T{sub 3} nuclear receptor kinetics in cold exposed swine and compared them with similar animals housed at thermoneutral temperature. Receptors were from isolated nuclear extracts of circulating mononuclear leukocytes (MNL). Scatchard analysis indicates the presence of a single class of binding sites. The authors were unable to detect differences in the equilibrium dissociation constant (Kd) or the maximum binding capacity (MBC, fmol/up DNA) between the two groups. The Kd for T{sub 3} in the control group was 1.17 {plus minus} 0.11 nmol/L and 1.25 {plus minus} 0.19 nmol/L in the cold exposed group. The MBC was 0.43 {plus minus} 0.04 fmol/ug DNA in the control group and 0.40 {plus minus} 0.06 fmol/L in the cold exposed group. In competition studies using thyroid hormone analogues, 10{sup {minus}7} M reverse T{sub 3} and 3,5-diiodothyronine resulted in approximately 50% displacement from the porcine receptor. TRIAC and L-T{sub 4} had no effect at 10{sup {minus}7} M. The porcine values for both Kd and MBC are similar to those previously reported for human MNL. Although T{sub 3} production and serum T{sub 3} values in the cold exposed group are nearly double the control group (Reed et al., FASEB 1991), continuous short-term cold exposure had no significant effect on MNL nuclear T{sub 3} receptor kinetics.

  13. [Hypothyroidism Associated to TSH Hormone-Receptor Autoantibodies with Blocking Activity Assessed In Vitro].

    PubMed

    Marques, Pedro; Chikh, Karim; Charrié, Anne; Pina, Rosa; Bugalho, Maria João; Lopes, Lurdes

    2015-01-01

    Thyroid-stimulating hormone-receptor autoantibodies normally causes hyperthyroidism. However, they might have blocking activity causing hypothyroidism. A 11-year-old girl followed due to type 1 diabetes mellitus, celiac disease and euthyroid lymphocytic thyroiditis at diagnosis. Two years after the initial evaluation, thyroid-stimulating hormone was suppressed with normal free T4; nine months later, a biochemical evolution to hypothyroidism with thyroid-stimulating hormone-receptor autoantibodies elevation was seen; the patient remained always asymptomatic. Chinese hamster ovary cells were transfected with the recombinant human thyroid-stimulating hormone -receptor, and then exposed to the patient's serum; it was estimated a 'moderate' blocking activity of these thyroid-stimulating hormone-receptor autoantibodies, and concomitantly excluded stimulating action. In this case, the acknowledgment of the blocking activity of the serum thyroid-stimulating hormone-receptor autoantibodies, supported the hypothesis of a multifactorial aetiology of the hypothyroidism, which in the absence of the in vitro tests, we would consider only as a consequence of the destructive process associated to lymphocytic thyroiditis.

  14. Molecular recognition of parathyroid hormone by its G protein-coupled receptor

    SciTech Connect

    Pioszak, Augen A.; Xu, H. Eric

    2008-08-07

    Parathyroid hormone (PTH) is central to calcium homeostasis and bone maintenance in vertebrates, and as such it has been used for treating osteoporosis. It acts primarily by binding to its receptor, PTH1R, a member of the class B G protein-coupled receptor (GPCR) family that also includes receptors for glucagon, calcitonin, and other therapeutically important peptide hormones. Despite considerable interest and much research, determining the structure of the receptor-hormone complex has been hindered by difficulties in purifying the receptor and obtaining diffraction-quality crystals. Here, we present a method for expression and purification of the extracellular domain (ECD) of human PTH1R engineered as a maltose-binding protein (MBP) fusion that readily crystallizes. The 1.95-{angstrom} structure of PTH bound to the MBP-PTH1R-ECD fusion reveals that PTH docks as an amphipathic helix into a central hydrophobic groove formed by a three-layer {alpha}-{beta}-{beta}{alpha} fold of the PTH1R ECD, resembling a hot dog in a bun. Conservation in the ECD scaffold and the helical structure of peptide hormones emphasizes this hot dog model as a general mechanism of hormone recognition common to class B GPCRs. Our findings reveal critical insights into PTH actions and provide a rational template for drug design that targets this hormone signaling pathway.

  15. Steroid hormone receptors in prostatic hyperplasia and prostatic carcinoma.

    PubMed

    Khalid, B A; Nurshireen, A; Rashidah, M; Zainal, B Y; Roslan, B A; Mahamooth, Z

    1990-06-01

    One hundred and six prostatic tissue samples obtained from transurethral resection were analysed for androgen and estrogen receptors. In 62 of these, progesterone and glucocorticoid receptors were also assayed. Steroid receptors were assayed using single saturation dose 3H-labelled ligand assays. Ninety percent of the 97 prostatic hyperplasia tissues and six of the nine prostatic carcinoma tissues were positive for androgen receptors. Estrogen receptors were only present in 19% and 33% respectively. Progesterone receptors were present in 70% of the tissues, but glucocorticoid receptors were present in only 16% of prostatic hyperplasia and none in prostatic carcinoma. PMID:1725553

  16. Nuclear receptor coactivators facilitate vitamin D receptor homodimer action on direct repeat hormone response elements.

    PubMed

    Takeshita, A; Ozawa, Y; Chin, W W

    2000-03-01

    Vitamin D receptor (VDR) is a ligand-dependent transcription factor that regulates target gene expression. Although VDR forms stable heterodimer complex with retinoid X receptors (RXRs) on vitamin D-response elements (VDREs), it is still not clear whether VDR/RXR heterodimers are the only VDR complexes responsible for vitamin D-mediated gene transcription. In this report, we analyzed the effect of nuclear receptor coactivators (SRC-1 and TRAM-1) on VDR homodimer and VDR/RXR heterodimer formation by electrophoretic mobility shift assay. We found that VDR forms stable homodimers after interaction with the coactivators on a VDRE (DR+3). Of particular note, DR+4 and DR+5 hormone-response elements (HREs) may also support such interactions. Cotransfection experiments revealed further that the coactivators enhance ligand-induced VDR transcription on these elements. Our studies suggest the important role of VDR homodimers, in addition to VDR/RXR heterodimers, in vitamin D-induced transactivation. Thus, specific coactivator-VDR interactions on HREs may determine target gene transactivation.

  17. The hormonal receptor status of uterine carcinosarcomas (mixed müllerian tumours): an immunohistochemical study.

    PubMed Central

    Ansink, A C; Cross, P A; Scorer, P; de Barros Lopes, A; Monaghan, J M

    1997-01-01

    AIM: To investigate the role of oestrogen and progesterone receptor status in uterine carcinosarcomas (mixed Müllerian tumours) to see whether the receptors were identifiable, and if so whether they were of significance clinically. METHODS: 11 cases of uterine carcinosarcoma were identified from clinical and pathology records. An immunohistochemical method was used to demonstrate oestrogen and progesterone hormone receptors on paraffin embedded material, with suitable tissue controls, staining being recorded. RESULTS: 10 of 11 cases showed staining for one or both hormone receptors in normal tissue adjacent to tumour. In four carcinosarcoma cases, staining for one or both receptors was shown within the epithelial component (appearing to correlate with the degree of epithelial differentiation); two of these cases had staining within sarcomatous areas. Two of the three patients still alive had epithelial hormone receptor positivity. CONCLUSIONS: Receptors for oestrogen and progesterone were found in four of 11 cases of uterine carcinosarcoma, using paraffin embedded material. There may be an association between hormone receptor positivity and clinical outcome. Images PMID:9215151

  18. Inflammation influences steroid hormone receptors targeted by progestins in endometrial stromal cells from women with endometriosis.

    PubMed

    Grandi, Giovanni; Mueller, Michael D; Papadia, Andrea; Kocbek, Vida; Bersinger, Nick A; Petraglia, Felice; Cagnacci, Angelo; McKinnon, Brett

    2016-09-01

    Endometriosis is an estrogen-dependent disease characterised by the growth of endometrial epithelial and stromal cells outside the uterus creating a chronic inflammatory environment that further contributes to disease progression. The first choice treatment for endometriosis is currently progestin mediated hormone modulation. In addition to their progestogenic activity however, progestins also have the potential to bind to other nuclear receptors influencing their local activity on endometriotic cells. This local activity will be dependent on the steroid hormone receptor expression that occurs in endometrial cells in a chronic inflammatory environment. We therefore aimed to quantify receptors targeted by progestins in endometrial stromal cells after exposure to inflammation. Using primary endometrial stromal cells isolated from women with endometriosis we examined the mRNA and protein expression of the progesterone receptors A and B, membrane progesterone receptors 1 and 2, androgen receptors, mineralocorticoid receptors and glucocorticoid receptors after exposure to the inflammatory cytokines tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β). The results indicate that both cytokines reduced the expression of progesterone receptors and increased the expression of the glucocorticoid receptors in the endometrial stromal cells. The change in expression of progestin targets in endometrial stromal cells in an inflammatory environment could contribute to the progesterone resistance observed in endometriotic cells and ultimately influence the design of hormonal therapies aimed at treating this disease. PMID:27371899

  19. Dietary regulation of adiponectin by direct and indirect lipid activators of nuclear hormone receptors.

    PubMed

    Rühl, R; Landrier, J F

    2016-01-01

    Adiponectin is an adipokine mainly secreted by adipocytes that presents antidiabetic, anti-inflammatory, and antiatherogenic functions. Therefore, modulation of adiponectin expression represents a promising target for prevention or treatment of several diseases including insulin resistance and type II diabetes. Pharmacological agents such as the nuclear hormone receptor synthetic agonists like peroxisome proliferator activated receptor γ agonists are of particular interest in therapeutic strategies due to their ability to increase the plasma adiponectin concentration. Nutritional approaches are also of particular interest, especially in primary prevention, since some active compounds of our diet (notably vitamins, carotenoids, or other essential nutrients) are direct or indirect lipid-activators of nuclear hormone receptors and are modifiers of adiponectin expression and secretion. The aim of the present review is to summarize current knowledge about the nutritional regulation of adiponectin by derivatives of active compounds naturally present in the diet acting as indirect or direct activators of nuclear hormone receptors.

  20. Receptor-level interrelationships of amino acids and the adequate amino acid type hormones in Tetrahymena: a receptor evolution model.

    PubMed

    Csaba, G; Darvas, Z

    1986-01-01

    Histidine stimulates the phagocytosis of Tetrahymena to the same extent as histamine, and also stimulates its division, which histamine does not. Tyrosine and diiodotyrosine equally stimulate the growth of the Tetrahymena. Both amino acids inhibit the characteristic influence of the adequate amino acid hormone when added to Tetrahymena culture 72 h in advance of it. Primary interaction with diiodotyrosine and tyrosine notably increases the cellular growth rate. Histamine has a similar, although less notable effect than histidine. In the light of these experimental observations there is reason to postulate that the receptors of the amino acid hormones have developed from amino acid receptors.

  1. Fluorescence detection of MSH-receptors in melanoma as a target of hormone-directed photosensitation in PDT

    NASA Astrophysics Data System (ADS)

    Roehrs, Susanne; Moser, Joerg G.; Salomon, Yoram

    1995-01-01

    MSH receptors are one of the possible targets to specifically attack melanoma cells by photodynamically active agents bound to melanotropic hormones. To attack effectively metastatic melanoma the presence of the hormone receptor has to be proven in metastases. Radioactive labeling of melanotropic hormones allows us to check for the presence of intact receptors. We tried to develop a non-radioactive immunological method as a first step to work out therapeutic strategies to attach photodynamically active porphyrins to the surface of melanoma cells.

  2. JNK pathway decreases thyroid hormones via TRH receptor: a novel mechanism for disturbance of thyroid hormone homeostasis by PCB153.

    PubMed

    Liu, Changjiang; Ha, Mei; Cui, Yushan; Wang, Chengmin; Yan, Maosheng; Fu, Wenjuan; Quan, Chao; Zhou, Jun; Yang, Kedi

    2012-12-01

    PCBs, widespread and well-characterized endocrine disruptors, cause the disruption of thyroid hormone (TH) homeostasis in humans and animals. In order to verify the hypotheses that MAPK pathways would play roles in disturbance of TH levels caused by PCBs, and that TH-associated receptors could function in certain MAPK pathway, Sprague-Dawley rats were dosed with PCB153 intraperitoneally (i.p.) at 0, 4, 16 and 32mg/kg for 5 consecutive days, and Nthy-ori 3-1 cells were treated with PCB153 (0, 1, 5, 10μM) for 30min. Results showed that after the treatment with PCB153, serum total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3) and thyrotropin releasing hormone (TRH) were decreased, whereas free triiodothyronine (FT3) and serum thyroid stimulating hormone (TSH) were not altered. In vivo and in vitro studies indicated that JNK pathway was activated after PCB153 exposure. Moreover, TRH receptor (TRHr) level was suppressed after the activation of JNK pathway and was elevated after the inhibition of JNK pathway, but TSH receptor (TSHr) level was not affected by the status of JNK pathway though it was reduced after PCB153 treatment. The activated signs of ERK and P38 pathways were not observed in this study. Taken together, observed effects suggested that JNK pathway could decrease TH levels via TRHr, and that would be one novel mechanism of PCB153-mediated disruption of THs.

  3. Effects of Hormonally Active Agents on Steroid Hormone Receptor Expression and Cell Proliferation in the Myometrium of Ovariectomized Macaques

    PubMed Central

    Hill, Georgette D.; Moore, Alicia B.; Kissling, Grace E.; Flagler, Norris D.; Ney, Elizabeth; Cline, J. Mark; Dixon, Darlene

    2011-01-01

    Hormone replacement therapy and selective estrogen receptor modulators have been controversial treatment options for postmenopausal women because of their potential health benefits and/or risks. In this study, we determine the effects of the hormonally active compounds, conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE + MPA, and tamoxifen (TAM) on the myometrium of ovariectomized macaques. Immunoexpression of estrogen receptor-α (ERα), progesterone receptor (PR), and Ki-67 in the myometrium is assessed. We found no significant difference in ERα myometrial expression in the CEE, MPA, and CEE + MPA treatment groups, but there was a significant decrease in expression in animals administered TAM versus controls. Conjugated equine estrogen−, TAM−, and CEE + MPA-treated animals had significantly increased expression of PR in myometrial cells and there was no difference in PR expression in cells from MPA-treated animals versus control animals. Myometrial cell proliferation did not significantly differ between the controls and any of the treatment groups, although normalized Ki-67 values were somewhat higher in the CEE and TAM groups. These data suggest that ERα and PR expression in the myometrium is influenced by treatment with hormonally active agents. PMID:21411722

  4. Phylogenetic Investigation of Peptide Hormone and Growth Factor Receptors in Five Dipteran Genomes

    PubMed Central

    Vogel, Kevin J.; Brown, Mark R.; Strand, Michael R.

    2013-01-01

    Peptide hormones and growth factors bind to membrane receptors and regulate a myriad of processes in insects and other metazoans. The evolutionary relationships among characterized and uncharacterized (“orphan”) receptors can provide insights into receptor-ligand biology and narrow target choices in deorphanization studies. However, the large number and low sequence conservation of these receptors make evolutionary analysis difficult. Here, we characterized the G-protein-coupled receptors (GPCRs), receptor guanylyl cyclases (RGCs), and protein kinase receptors (PKRs) of mosquitoes and select other flies by interrogating the genomes of Aedes aegypti, Anopheles gambiae, Culex quinquefasciatus, Drosophila melanogaster, and D. mojavensis. Sequences were grouped by receptor type, clustered using the program CLANS, aligned using HMMR, and phylogenetic trees built using PhyML. Our results indicated that PKRs had relatively few orphan clades whereas GPCRs and RGCs had several. In addition, more than half of the Class B secretin-like GPCRs and RGCs remained uncharacterized. Additional studies revealed that Class B GPCRs exhibited more gain and loss events than other receptor types. Finally, using the neuropeptide F family of insect receptors and the neuropeptide Y family of vertebrate receptors, we also show that functional sites considered critical for ligand binding are conserved among distinct family members and between distantly related taxa. Overall, our results provide the first comprehensive analysis of peptide hormone and growth factor receptors for a major insect group. PMID:24379806

  5. A lophotrochozoan-specific nuclear hormone receptor is required for reproductive system development in the planarian.

    PubMed

    Tharp, Marla E; Collins, James J; Newmark, Phillip A

    2014-12-01

    Germ cells of sexually reproducing organisms receive an array of cues from somatic tissues that instruct developmental processes. Although the nature of these signals differs amongst organisms, the importance of germline-soma interactions is a common theme. Recently, peptide hormones from the nervous system have been shown to regulate germ cell development in the planarian Schmidtea mediterranea; thus, we sought to investigate a second class of hormones with a conserved role in reproduction, the lipophilic hormones. In order to study these signals, we identified a set of putative lipophilic hormone receptors, known as nuclear hormone receptors, and analyzed their functions in reproductive development. We found one gene, nhr-1, belonging to a small class of functionally uncharacterized lophotrochozoan-specific receptors, to be essential for the development of differentiated germ cells. Upon nhr-1 knockdown, germ cells in the testes and ovaries fail to mature, and remain as undifferentiated germline stem cells. Further analysis revealed that nhr-1 mRNA is expressed in the accessory reproductive organs and is required for their development, suggesting that this transcription factor functions cell non-autonomously in regulating germ cell development. Our studies identify a role for nuclear hormone receptors in planarian reproductive maturation and reinforce the significance of germline-soma interactions in sexual reproduction across metazoans.

  6. Impaired hair growth and wound healing in mice lacking thyroid hormone receptors.

    PubMed

    Contreras-Jurado, Constanza; García-Serrano, Laura; Martínez-Fernández, Mónica; Ruiz-Llorente, Lidia; Paramio, Jesus M; Aranda, Ana

    2014-01-01

    Both clinical and experimental observations show that the skin is affected by the thyroidal status. In hypothyroid patients the epidermis is thin and alopecia is common, indicating that thyroidal status might influence not only skin proliferation but also hair growth. We demonstrate here that the thyroid hormone receptors (TRs) mediate these effects of the thyroid hormones on the skin. Mice lacking TRα1 and TRβ (the main thyroid hormone binding isoforms) display impaired hair cycling associated to a decrease in follicular hair cell proliferation. This was also observed in hypothyroid mice, indicating the important role of the hormone-bound receptors in hair growth. In contrast, the individual deletion of either TRα1 or TRβ did not impair hair cycling, revealing an overlapping or compensatory role of the receptors in follicular cell proliferation. In support of the role of the receptors in hair growth, TRα1/TRβ-deficient mice developed alopecia after serial depilation. These mice also presented a wound-healing defect, with retarded re-epithelialization and wound gaping, associated to impaired keratinocyte proliferation. These results reinforce the idea that the thyroid hormone nuclear receptors play an important role on skin homeostasis and suggest that they could be targets for the treatment of cutaneous pathologies.

  7. The expression of growth hormone-releasing hormone (GHRH) and splice variants of its receptor in human gastroenteropancreatic carcinomas

    PubMed Central

    Busto, Rebeca; Schally, Andrew V.; Varga, Jozsef L.; Garcia-Fernandez, M. Olga; Groot, Kate; Armatis, Patricia; Szepeshazi, Karoly

    2002-01-01

    Splice variants (SVs) of receptors for growth hormone-releasing hormone (GHRH) have been found in primary human prostate cancers and diverse human cancer cell lines. GHRH antagonists inhibit growth of various experimental human cancers, including pancreatic and colorectal, xenografted into nude mice or cultured in vitro, and their antiproliferative action could be mediated in part through SVs of GHRH receptors. In this study we examined the expression of mRNA for GHRH and for SVs of its receptors in tumors of human pancreatic, colorectal, and gastric cancer cell lines grown in nude mice. mRNA for both GHRH and SV1 isoform of GHRH receptors was expressed in tumors of pancreatic (SW1990, PANC-1, MIA PaCa-2, Capan-1, Capan-2, and CFPAC1), colonic (COLO 320DM and HT-29), and gastric (NCI-N87, HS746T, and AGS) cancer cell lines; mRNA for SV2 was also present in Capan-1, Capan-2, CFPAC1, HT-29, and NCI-N87 tumors. In proliferation studies in vitro, the growth of pancreatic, colonic, and gastric cancer cells was stimulated by GHRH(1–29)NH2 and inhibited by GHRH antagonist JV-1–38. The stimulation of some gastroenteropancreatic cancer cells by GHRH was followed by an increase in cAMP production, and GHRH antagonist JV-1–38 competitively inhibited this effect. Our study indicates the presence of an autocrine/paracrine stimulatory loop based on GHRH and SV1 of GHRH receptors in human pancreatic, colorectal, and gastric cancers. The finding of SV1 receptor in human cancers provides an approach to an antitumor therapy based on the blockade of this receptor by specific GHRH antagonists. PMID:12186980

  8. Receptor domains involved in signal transduction of prolactin and growth hormone

    SciTech Connect

    Kelly, P.A.; Edery, M.; Finidori, J.

    1994-12-31

    Prolactin (PRL) and growth hormone (GH) receptors are members of a superfamily that include receptors for a number of cytokines. GH and its receptor form an unusual homodimer consisting of one molecule of GH and two molecules of receptor. A similar homodimer of the PRL receptor is probably required for biological effects to be seen. Using specific assays to measure the functional activity of PRL and GH receptors, a 25 amino acid juxtamembrane region has been identified as essential but not sufficient for normal action. More detailed studies have limited the region to eight amino acids, rich in prolines, that is highly conserved in many members of the receptor superfamily. Finally, GH and PRL have been shown to induce the rapid tyrosine phosphorylation of an associated kinase, Janus kinase 2, and of the receptor itself. 28 refs., 1 fig.

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

    SciTech Connect

    Billestrup, N.; Moeldrup, A.; Serup, P.; Nielsen, J.H. ); Mathews, L.S.; Norstedt, G. )

    1990-09-01

    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, the authors have transfected a GH receptor cDNA under the transcriptional control of the human metallothionein promoter into RIN5-AH cells. The transfected cells were found to exhibit an increased expression of GH receptors and to contain a specific GH receptor mRNA that was not expressed in the parent cell line. The expression of GH receptors in one clone (1.24) selected for detailed analysis was increased 2.6-fold compared to untransfected cells. The increased GH receptor expression was accompanied by an increased responsiveness to GH. Thus, the maximal GH-stimulated increase of insulin biosynthesis was 4.1-fold in 1.24 cells compared to 1.9-fold in the nontransfected RIN5-AH cells. The expression of the transfected receptor was stimulated 1.6- and 2.3-fold when cells were cultured in the presence of 25 or 50 {mu}M Zn{sup 2+} was associated with an increased magnitude of GH-stimulated insulin biosynthesis. A close stoichiometric relationship between the level of receptor expression and the level of GH-stimulated insulin biosynthesis was observed. They conclude from these results that the hepatic GH receptor is able to mediate the effect of GH on insulin biosynthesis in RIN5-AH cells.

  10. TRα receptor mutations extend the spectrum of syndromes of reduced sensitivity to thyroid hormone.

    PubMed

    Vlaeminck-Guillem, Virginie; Espiard, Stéphanie; Flamant, Frédéric; Wémeau, Jean-Louis

    2015-11-01

    Since 2012, eight different abnormalities have been described in the THRA gene (encoding the TRα1 thyroid hormone receptor) of 14 patients from 9 families. These mutations induce a clinical phenotype (resistance to thyroid hormone type α) associating symptoms of untreated mild congenital hypothyroidism and a near-normal range of free and total thyroid hormones and TSH (the T4/T3 ratio is nevertheless usually low). The phenotype can diversely include short stature (due to growth retardation), dysmorphic syndrome (face and limb extremities), psychoneuromotor disorders, constipation and bradycardia. The identified genetic abnormalities are located within the ligand-binding domain and result in defective T3 binding, an abnormally strong interaction with corepressors and a dominant negative activity against still functional receptors. The identification of patients with consistent phenotypes and the underlying mutations are warranted to better delineate the spectrum of the syndromes of reduced sensitivity to thyroid hormone. PMID:26585273

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

    PubMed

    Tam, Janice K V; Chow, Billy K C; Lee, Leo T O

    2013-01-01

    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.

  12. International Union of Basic and Clinical Pharmacology. XCIII. The parathyroid hormone receptors--family B G protein-coupled receptors.

    PubMed

    Gardella, Thomas J; Vilardaga, Jean-Pierre

    2015-01-01

    The type-1 parathyroid hormone receptor (PTHR1) is a family B G protein-coupled receptor (GPCR) that mediates the actions of two polypeptide ligands; parathyroid hormone (PTH), an endocrine hormone that regulates the levels of calcium and inorganic phosphate in the blood by acting on bone and kidney, and PTH-related protein (PTHrP), a paracrine-factor that regulates cell differentiation and proliferation programs in developing bone and other tissues. The type-2 parathyroid hormone receptor (PTHR2) binds a peptide ligand, called tuberoinfundibular peptide-39 (TIP39), and while the biologic role of the PTHR2/TIP39 system is not as defined as that of the PTHR1, it likely plays a role in the central nervous system as well as in spermatogenesis. Mechanisms of action at these receptors have been explored through a variety of pharmacological and biochemical approaches, and the data obtained support a basic "two-site" mode of ligand binding now thought to be used by each of the family B peptide hormone GPCRs. Recent crystallographic studies on the family B GPCRs are providing new insights that help to further refine the specifics of the overall receptor architecture and modes of ligand docking. One intriguing pharmacological finding for the PTHR1 is that it can form surprisingly stable complexes with certain PTH/PTHrP ligand analogs and thereby mediate markedly prolonged cell signaling responses that persist even when the bulk of the complexes are found in internalized vesicles. The PTHR1 thus appears to be able to activate the Gα(s)/cAMP pathway not only from the plasma membrane but also from the endosomal domain. The cumulative findings could have an impact on efforts to develop new drug therapies for the PTH receptors.

  13. Prolonged signaling at the parathyroid hormone receptor by peptide ligands targeted to a specific receptor conformation

    PubMed Central

    Okazaki, Makoto; Ferrandon, Sebastien; Vilardaga, Jean-Pierre; Bouxsein, Mary L.; Potts, John T.; Gardella, Thomas J.

    2008-01-01

    The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both the amino-terminal extracellular (N) domain, and transmembrane/extracellular loop, or juxtamembrane (J) regions of the receptor. Recently, we found that PTH(1–34), but not PTH-related protein, PTHrP(1–36), or M-PTH(1–14) (M = Ala/Aib1,Aib3,Gln10,Har11,Ala12,Trp14,Arg19), binds to the PTHR in a largely GTPγS-resistant fashion, suggesting selective binding to a novel, high-affinity conformation (R0), distinct from the GTPγS-sensitive conformation (RG). We examined the effects in vitro and in vivo of introducing the M substitutions, which enhance interaction to the J domain, into PTH analogs extended C-terminally to incorporate residues involved in the N domain interaction. As compared with PTH(1–34), M-PTH(1–28) and M-PTH(1–34) bound to R0 with higher affinity, produced more sustained cAMP responses in cells, formed more stable complexes with the PTHR in FRET and subcellular localization assays, and induced more prolonged calcemic and phosphate responses in mice. Moreover, after 2 weeks of daily injection in mice, M-PTH(1–34) induced larger increases in trabecular bone volume and greater increases in cortical bone turnover, than did PTH(1–34). Thus, the putative R0 PTHR conformation can form highly stable complexes with certain PTH ligand analogs and thereby mediate surprisingly prolonged signaling responses in bone and/or kidney PTH target cells. Controlling, via ligand analog design, the selectivity with which a PTH ligand binds to R0, versus RG, may be a strategy for optimizing signaling duration time, and hence therapeutic efficacy, of PTHR agonist ligands. PMID:18946036

  14. Analysis of Paired Primary-Metastatic Hormone-Receptor Positive Breast Tumors (HRPBC) Uncovers Potential Novel Drivers of Hormonal Resistance

    PubMed Central

    Manso, Luis; Mourón, Silvana; Tress, Michael; Gómez-López, Gonzalo; Morente, Manuel; Ciruelos, Eva; Rubio-Camarillo, Miriam; Rodriguez-Peralto, Jose Luis; Pujana, Miguel A.; Pisano, David G.; Quintela-Fandino, Miguel

    2016-01-01

    We sought to identify genetic variants associated with disease relapse and failure to hormonal treatment in hormone-receptor positive breast cancer (HRPBC). We analyzed a series of HRPBC with distant relapse, by sequencing pairs (n = 11) of tumors (primary and metastases) at >800X. Comparative genomic hybridization was performed as well. Top hits, based on the frequency of alteration and severity of the changes, were tested in the TCGA series. Genes determining the most parsimonious prognostic signature were studied for their functional role in vitro, by performing cell growth assays in hormonal-deprivation conditions, a setting that mimics treatment with aromatase inhibitors. Severe alterations were recurrently found in 18 genes in the pairs. However, only MYC, DNAH5, CSFR1, EPHA7, ARID1B, and KMT2C preserved an independent prognosis impact and/or showed a significantly different incidence of alterations between relapsed and non-relapsed cases in the TCGA series. The signature composed of MYC, KMT2C, and EPHA7 best discriminated the clinical course, (overall survival 90,7 vs. 144,5 months; p = 0.0001). Having an alteration in any of the genes of the signature implied a hazard ratio of death of 3.25 (p<0.0001), and early relapse during the adjuvant hormonal treatment. The presence of the D348N mutation in KMT2C and/or the T666I mutation in the kinase domain of EPHA7 conferred hormonal resistance in vitro. Novel inactivating mutations in KMT2C and EPHA7, which confer hormonal resistance, are linked to adverse clinical course in HRPBC. PMID:27195705

  15. Synergistic Induction of Follicle-Stimulating Hormone β-Subunit Gene Expression by Gonadal Steroid Hormone Receptors and Smad Proteins

    PubMed Central

    Thackray, Varykina G.; Mellon, Pamela L.

    2008-01-01

    LH and FSH play crucial roles in mammalian reproduction by mediating steroidogenesis and gametogenesis. Gonadal steroid hormones influence gonadotropin production via feedback to the hypothalamus and pituitary. We previously demonstrated that progesterone and testosterone can stimulate expression of the FSH β-subunit gene in immortalized gonadotrope-derived LβT2 cells. Herein, we investigate how these gonadal steroids modulate activin signaling in the gonadotrope. Cotreatment of LβT2 cells or mouse primary pituitary cells with steroids and activin results in a synergistic induction of FSHβ gene expression. This synergy decreases when DNA-binding mutations are introduced into the steroid receptors or when mutations that reduce steroid hormone responsiveness are introduced into the FSHβ promoter, indicating that synergy requires direct DNA binding of the steroid receptors. Furthermore, classical activin signaling via Smad proteins is necessary for this synergy. In addition, these steroid receptors physically interact with Smads and are sufficient for the synergism to occur on the FSHβ promoter. Disruption of Smad binding to the promoter with a Smad protein lacking the DNA-binding domain or an FSHβ promoter containing mutated activin-response elements prevents the synergistic enhancement of FSHβ transcription. Collectively, our data demonstrate that the molecular mechanism for gonadal steroid hormone action on the FSHβ promoter involves cross-talk between the steroid and activin signaling pathways. They also reveal that this synergism requires binding of both the steroid receptors and Smad proteins to their cognate DNA-binding elements and likely involves a direct protein-protein interaction between the two types of transcription factors. PMID:18079204

  16. Pituitary gonadotrophic hormone synthesis, secretion, subunit gene expression and cell structure in normal and follicle-stimulating hormone β knockout, follicle-stimulating hormone receptor knockout, luteinising hormone receptor knockout, hypogonadal and ovariectomised female mice.

    PubMed

    Abel, M H; Widen, A; Wang, X; Huhtaniemi, I; Pakarinen, P; Kumar, T R; Christian, H C

    2014-11-01

    To investigate the relationship between gonadotroph function and ultrastructure, we have compared, in parallel in female mice, the effects of several different mutations that perturb the hypothalamic-pituitary-gonadal axis. Specifically, serum and pituitary gonadotrophin concentrations, gonadotrophin gene expression, gonadotroph structure and number were measured. Follicle-stimulating hormone β knockout (FSHβKO), follicle-stimulating hormone receptor knockout (FSHRKO), luteinising hormone receptor knockout (LuRKO), hypogonadal (hpg) and ovariectomised mice were compared with control wild-type or heterozygote female mice. Serum levels of LH were elevated in FSHβKO and FSHRKO compared to heterozygote females, reflecting the likely decreased oestrogen production in KO females, as demonstrated by the threadlike uteri and acyclicity. As expected, there was no detectable FSH in the serum or pituitary and an absence of expression of the FSHβ subunit gene in FSHβKO mice. However, there was a significant increase in expression of the FSHβ and LHβ subunit genes in FSHRKO female mice. The morphology of FSHβKO and FSHRKO gonadotrophs was not significantly different from the control, except that secretory granules in FSHRKO gonadotrophs were larger in diameter. In LuRKO and ovariectomised mice, stimulation of LHβ and FSHβ mRNA, as well as serum protein concentrations, were reflected in subcellular changes in gonadotroph morphology, including more dilated rough endoplasmic reticula and fewer, larger secretory granules. In the gonadotophin-releasing hormone deficient hpg mouse, gonadotrophin mRNA and protein levels were significantly lower than in control mice and gonadotrophs were correspondingly smaller with less abundant endoplasmic reticula and reduced numbers of secretory granules. In summary, major differences in pituitary content and serum concentrations of the gonadotrophins LH and FSH were found between control and mutant female mice. These changes were

  17. ERrrr…where are the progenitors? Hormone receptors and mammary cell heterogeneity.

    PubMed

    Tornillo, Giusy; Smalley, Matthew J

    2015-06-01

    The mammary epithelium is a highly heterogenous and dynamic tissue that includes a range of cell types with varying levels of proliferative capacity and differentiation potential, from stem to committed progenitor and mature cells. Generation of mature cells through expansion and specification of immature precursors is driven by hormonal and local stimuli. Intriguingly, although circulating hormones can be directly sensed only by a subset of mammary cells, they also regulate the behaviour of cells lacking their cognate receptors through paracrine mechanisms. Thus, mapping the hormonal signalling network on to the emerging mammary cell hierarchy appears to be a difficult task. Nevertheless, a first step towards a better understanding is the characterization of the hormone receptor expression pattern across individual cell types in the mammary epithelium. Here we review the most relevant findings on the cellular distribution of hormone receptors in the mammary gland, taking into account differences between mice and humans, the methods employed to assess receptor expression as well as the variety of approaches used to resolve the mammary cell heterogeneity.

  18. Nuclear hormone receptor functions in keratinocyte and melanocyte homeostasis, epidermal carcinogenesis and melanomagenesis

    PubMed Central

    Hyter, Stephen; Indra, Arup K

    2013-01-01

    Skin homeostasis is maintained, in part, through regulation of gene expression orchestrated by type II nuclear hormone receptors in a cell and context specific manner. This group of transcriptional regulators is implicated in various cellular processes including epidermal proliferation, differentiation, permeability barrier formation, follicular cycling and inflammatory responses. Endogenous ligands for the receptors regulate actions during skin development and maintenance of tissue homeostasis. Type II nuclear receptor signaling is also important for cellular crosstalk between multiple cell types in the skin. Overall, these nuclear receptors are critical players in keratinocyte and melanocyte biology and present targets for cutaneous disease management. PMID:23395795

  19. CORAL: prediction of binding affinity and efficacy of thyroid hormone receptor ligands.

    PubMed

    Toropova, A P; Toropov, A A; Benfenati, E

    2015-08-28

    Quantitative structure - activity relationships (QSARs) for binding affinity of thyroid hormone receptors based on attributes of molecular structure extracted from simplified molecular input-line entry systems (SMILES) are established using the CORAL software (http://www.insilico.eu/coral). The half maximal inhibitory concentration (IC50) is used as the measure of the binding affinity of thyroid hormone receptors. Molecular features which are statistically reliable promoters of increase and decrease for IC50 are suggested. The examples of modifications of molecular structure which lead to the increase or to the decrease of the endpoint are represented. PMID:26188619

  20. Gustatory perception and fat body energy metabolism are jointly affected by vitellogenin and juvenile hormone in honey bees.

    PubMed

    Wang, Ying; Brent, Colin S; Fennern, Erin; Amdam, Gro V

    2012-06-01

    Honey bees (Apis mellifera) provide a system for studying social and food-related behavior. A caste of workers performs age-related tasks: young bees (nurses) usually feed the brood and other adult bees inside the nest, while older bees (foragers) forage outside for pollen, a protein/lipid source, or nectar, a carbohydrate source. The workers' transition from nursing to foraging and their foraging preferences correlate with differences in gustatory perception, metabolic gene expression, and endocrine physiology including the endocrine factors vitellogenin (Vg) and juvenile hormone (JH). However, the understanding of connections among social behavior, energy metabolism, and endocrine factors is incomplete. We used RNA interference (RNAi) to perturb the gene network of Vg and JH to learn more about these connections through effects on gustation, gene transcripts, and physiology. The RNAi perturbation was achieved by single and double knockdown of the genes ultraspiracle (usp) and vg, which encode a putative JH receptor and Vg, respectively. The double knockdown enhanced gustatory perception and elevated hemolymph glucose, trehalose, and JH. We also observed transcriptional responses in insulin like peptide 1 (ilp1), the adipokinetic hormone receptor (AKHR), and cGMP-dependent protein kinase (PKG, or "foraging gene" Amfor). Our study demonstrates that the Vg-JH regulatory module controls changes in carbohydrate metabolism, but not lipid metabolism, when worker bees shift from nursing to foraging. The module is also placed upstream of ilp1, AKHR, and PKG for the first time. As insulin, adipokinetic hormone (AKH), and PKG pathways influence metabolism and gustation in many animals, we propose that honey bees have conserved pathways in carbohydrate metabolism and conserved connections between energy metabolism and gustatory perception. Thus, perhaps the bee can make general contributions to the understanding of food-related behavior and metabolic disorders.

  1. Receptors bound to antiprogestin from abortive complexes with hormone responsive elements.

    PubMed

    Guiochon-Mantel, A; Loosfelt, H; Ragot, T; Bailly, A; Atger, M; Misrahi, M; Perricaudet, M; Milgrom, E

    1988-12-15

    The mechanism of action of antisteroids is not understood and explanations of their antagonistic activity have been sought at all levels of hormone action. It has been proposed that antisteroids, after binding to receptor, trap it into a non-activated (non DNA-binding) form possibly through interaction with a heat-shock protein of relative molecular mass (Mr) 90,000 (90 K), or that the antisteroids provoke binding of receptor to nonspecific DNA sites but not to hormone responsive elements (HREs), or that the antisteroid-receptor complexes can bind to HREs but form abortive complexes that fail to regulate transcription. We have constructed a deleted cDNA encoding a mutant form of rabbit progesterone receptor which exhibits constitutive activity, that is, binds to HREs in the absence of hormone and thus bypasses the first two steps discussed above. Co-transfection experiments allowed the expression of both constitutive and wild-type receptors in the same recipient cells. Antiprogestin RU486-wild-type receptor complexes completely suppressed the activity of the constitutive receptor on a reporter gene, showing that the inhibition is at the level of their common responsive elements. PMID:3200320

  2. Immunolocalization of steroid hormone receptors in normal and tumour cells: mechanisms of their cellular traffic.

    PubMed

    Perrot-Applanat, M; Guiochon-Mantel, A; Milgrom, E

    1992-01-01

    Experimental conditions are described for the detection of steroid receptors in tissue sections or cells at the light microscope level. Current knowledge about the ultrastructural distribution of these receptors is summarized; the mechanisms of their nuclear localization are described. Karyophilic signals involved in nuclear translocation are characterized by means of in vitro mutagenesis of steroid receptor cDNAs. Studies analysing the subcellular distribution of various transfected receptor mutants in energy depleted cells together with fusion experiments provide evidence for nucleoplasmic shuttling of progesterone receptors. We conclude that the "nuclear" location of the wild type progesterone receptor reflects a dynamic equilibrium between active nuclear import and outward diffusion. We also describe the use of immunocytochemistry in pathology, especially for the detection of steroid receptors in hormone dependent tumours. PMID:1423330

  3. Hormones

    MedlinePlus

    Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

  4. Molecular analysis of the koala reproductive hormones and their receptors: gonadotrophin-releasing hormone (GnRH), follicle-stimulating hormone β and luteinising hormone β with localisation of GnRH.

    PubMed

    Busby, E R; Soeta, S; Sherwood, N M; Johnston, S D

    2014-12-01

    During evolution, reproductive hormones and their receptors in the brain-pituitary-gonadal axis have been altered by genetic mechanisms. To understand how the neuroendocrine control of reproduction evolved in mammals, it is important to examine marsupials, the closest group to placental mammals. We hypothesised that at least some of the hormones and receptors found in placental mammals would be present in koala, a marsupial. We examined the expression of koala mRNA for the reproductive molecules. Koala cDNAs were cloned from brain for gonadotrophin-releasing hormones (GnRH1 and GnRH2) or from pituitary for GnRH receptors, types I and II, follicle-stimulating hormone (FSH)β and luteinising hormone (LH)β, and from gonads for FSH and LH receptors. Deduced proteins were compared by sequence alignment and phylogenetic analysis with those of other vertebrates. In conclusion, the koala expressed mRNA for these eight putative reproductive molecules, whereas at least one of these molecules is missing in some species in the amniote lineage, including humans. In addition, GnRH1 and 2 are shown by immunohistochemistry to be expressed as proteins in the brain.

  5. Molecular analysis of the koala reproductive hormones and their receptors: gonadotrophin-releasing hormone (GnRH), follicle-stimulating hormone β and luteinising hormone β with localisation of GnRH.

    PubMed

    Busby, E R; Soeta, S; Sherwood, N M; Johnston, S D

    2014-12-01

    During evolution, reproductive hormones and their receptors in the brain-pituitary-gonadal axis have been altered by genetic mechanisms. To understand how the neuroendocrine control of reproduction evolved in mammals, it is important to examine marsupials, the closest group to placental mammals. We hypothesised that at least some of the hormones and receptors found in placental mammals would be present in koala, a marsupial. We examined the expression of koala mRNA for the reproductive molecules. Koala cDNAs were cloned from brain for gonadotrophin-releasing hormones (GnRH1 and GnRH2) or from pituitary for GnRH receptors, types I and II, follicle-stimulating hormone (FSH)β and luteinising hormone (LH)β, and from gonads for FSH and LH receptors. Deduced proteins were compared by sequence alignment and phylogenetic analysis with those of other vertebrates. In conclusion, the koala expressed mRNA for these eight putative reproductive molecules, whereas at least one of these molecules is missing in some species in the amniote lineage, including humans. In addition, GnRH1 and 2 are shown by immunohistochemistry to be expressed as proteins in the brain. PMID:25200132

  6. Analysis of androgen receptor and anti-Müllerian hormone pathways in human granulosa cells under luteinizing hormone treatment

    PubMed Central

    2013-01-01

    Background The objective of this study was to determine the gene expression profiles of the androgen/androgen receptor (AR) and anti-Müllerian hormone (AMH)/ Sry-related high-mobility group box 9 (SOX9) pathways in granulosa-luteal cells from patients undergoing standard in vitro fertilization (IVF) with or without recombinant luteinizing hormone (rLH) therapy. Methods Levels of reproductive hormones in the pre-ovulatory follicular fluid and the expression levels of LHR (luteinizing hormone receptor), AR, SOX9, AMH, AR-associated protein 54(ARA54)and ARA70 were determined in granulosa-luteal cells by real-time reverse-transcription PCR. The effects of androgen and rLH treatments on AR and AMH expression levels were also tested in vitro using HO23 cells. Results We collected 35 an 70 granulosa cell samples from patients cycled with and without rLH supplementation, respectively. The clinical outcomes were similar in patients who received rLH therapy and those who did not, though the pre-ovulatory follicular fluid levels of androstenedione, testosterone, and estradiol were significantly higher and progesterone was lower in the rLH supplementation group. Moreover, granulosa-luteal cell mRNA levels of LHR, AR, AMH, and SOX9 were significantly higher in the rLH supplementation group relative to the group that did not receive rLH supplementation. In addition, we observed significant correlations between LHR and AR mRNA expression and among AR, AMH, and SOX9 mRNA expression in granulosa-luteal cells from patients undergoing standard IVF treatment. Conclusions Increased expression of LHR, AR, AMH, and SOX9 is characteristic of granulosa-luteal cells from IVF/ intracytoplasmic sperm injection (ICSI) patients receiving rLH supplementation. PMID:23433069

  7. A new mechanism for growth hormone receptor activation of JAK2, and implications for related cytokine receptors

    PubMed Central

    Waters, Michael J; Brooks, Andrew J; Chhabra, Yash

    2014-01-01

    The growth hormone receptor was the first cytokine receptor to be cloned and crystallized, and provides a valuable exemplar for activation of its cognate kinase, JAK2. We review progress in understanding its activation mechanism, in particular the molecular movements made by this constitutively dimerized receptor in response to ligand binding, and how these lead to a separation of JAK-binding Box1 motifs. Such a separation leads to removal of the pseudokinase inhibitory domain from the kinase domain of a partner JAK2 bound to the receptor, and vice versa, leading to apposition of the kinase domains and transactivation. This may be a general mechanism for class I cytokine receptor action. PMID:25101218

  8. Desensitization, Trafficking, and Resensitization of the Pituitary Thyrotropin-Releasing Hormone Receptor

    PubMed Central

    Hinkle, Patricia M.; Gehret, Austin U.; Jones, Brian W.

    2012-01-01

    The pituitary receptor for thyrotropin-releasing hormone (TRH) is a calcium-mobilizing G protein-coupled receptor (GPCR) that signals through Gq/11, elevating calcium, and activating protein kinase C. TRH receptor signaling is quickly desensitized as a consequence of receptor phosphorylation, arrestin binding, and internalization. Following activation, TRH receptors are phosphorylated at multiple Ser/Thr residues in the cytoplasmic tail. Phosphorylation catalyzed by GPCR kinase 2 (GRK2) takes place rapidly, reaching a maximum within seconds. Arrestins bind to two phosphorylated regions, but only arrestin bound to the proximal region causes desensitization and internalization. Phosphorylation at Thr365 is critical for these responses. TRH receptors internalize in clathrin-coated vesicles with bound arrestin. Following endocytosis, vesicles containing phosphorylated TRH receptors soon merge with rab5-positive vesicles. Over approximately 20 min these form larger endosomes rich in rab4 and rab5, early sorting endosomes. After TRH is removed from the medium, dephosphorylated receptors start to accumulate in rab4-positive, rab5-negative recycling endosomes. The mechanisms responsible for sorting dephosphorylated receptors to recycling endosomes are unknown. TRH receptors from internal pools help repopulate the plasma membrane. Dephosphorylation of TRH receptors begins when TRH is removed from the medium regardless of receptor localization, although dephosphorylation is fastest when the receptor is on the plasma membrane. Protein phosphatase 1 is involved in dephosphorylation but the details of how the enzyme is targeted to the receptor remain obscure. It is likely that future studies will identify biased ligands for the TRH receptor, novel arrestin-dependent signaling pathways, mechanisms responsible for targeting kinases and phosphatases to the receptor, and principles governing receptor trafficking. PMID:23248581

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

    PubMed Central

    2010-01-01

    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. PMID:20979597

  10. Structure of follicle-stimulating hormone in complex with the entire ectodomain of its receptor

    PubMed Central

    Jiang, Xuliang; Liu, Heli; Chen, Xiaoyan; Chen, Po-Han; Fischer, David; Sriraman, Venkataraman; Yu, Henry N.; Arkinstall, Steve; He, Xiaolin

    2012-01-01

    FSH, a glycoprotein hormone, and the FSH receptor (FSHR), a G protein-coupled receptor, play central roles in human reproduction. We report the crystal structure of FSH in complex with the entire extracellular domain of FSHR (FSHRED), including the enigmatic hinge region that is responsible for signal specificity. Surprisingly, the hinge region does not form a separate structural unit as widely anticipated but is part of the integral structure of FSHRED. In addition to the known hormone-binding site, FSHRED provides interaction sites with the hormone: a sulfotyrosine (sTyr) site in the hinge region consistent with previous studies and a potential exosite resulting from putative receptor trimerization. Our structure, in comparison to others, suggests FSHR interacts with its ligand in two steps: ligand recruitment followed by sTyr recognition. FSH first binds to the high-affinity hormone-binding subdomain of FSHR and reshapes the ligand conformation to form a sTyr-binding pocket. FSHR then inserts its sTyr (i.e., sulfated Tyr335) into the FSH nascent pocket, eventually leading to receptor activation. PMID:22802634

  11. Gonadotropin hormone and receptor sequences from model teleost species.

    PubMed

    Wong, Andrew C; Van Eenennaam, Alison L

    2004-01-01

    Fish offer some advantages for the study of vertebrate reproductive physiology. Only a few of the genes encoding the components of the hypothalamic-pituitary-gonadal axis have been identified from model teleosts. This study describes a combination of database searching and molecular approaches to identify the FSH and LH gonadotropin beta-subunits (fshb and lhb, respectively), and the LH receptor (lhr) from two model teleost species: zebrafish (Danio rerio) and Fugu (Takifugu rubripes). Sequence and phylogenetic analyses were used to examine the relationships that exist between gonadotropins and their receptors from species representing several piscine orders. The gonadotropin alpha-subunit (Cga) is highly conserved among teleosts and tetrapods. The presence of a genomic pseudogene (cgap) was also noted in zebrafish. Generally, teleostean FSHbeta protein sequences share less identity with each other than do LHbeta protein sequences, supporting the hypothesis that FSHbeta diverged more rapidly during teleost evolution. Interestingly, and uniquely, zebrafish Fshb lacked two highly conserved cysteine residues in the "determinant loop" which is thought to contribute towards receptor binding and specificity. Teleost gonadotropin receptor sequences clearly diverged into two distinct groups, FSHR and LHR. As has been seen with mammalian gonadotropin receptor transcripts, splice variants of zebrafish lhr were also observed.

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

    PubMed

    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.

  13. Arsenic impacted the development, thyroid hormone and gene transcription of thyroid hormone receptors in bighead carp larvae (Hypophthalmichthys nobilis).

    PubMed

    Sun, Hong-Jie; Xiang, Ping; Tang, Ming-Hu; Sun, Li; Ma, Lena Q

    2016-02-13

    Arsenic (As) contamination in aquatic environment adversely impacts aquatic organisms. The present study assessed the toxicity of different As species and concentrations on bighead carp (Hypophthalmichthys nobilis) at early life stage, a major fish in Yangtze River, China. We measured the changes in embryo and larvae survival rate, larvae aberration, concentrations of thyroid hormone thyroxine, and transcription levels of thyroid hormone receptors (TRs) in fish larvae after exposing to arsenite (AsIII) or arsenate (AsV) at 0, 10, 30, 50, 100, or 150 μg L(-1) for 78 h. As concentrations ≤ 150 μg L(-1) had limited effect on embryo survival rate (6-8% inhibition), but larvae survival rate decreased to 53-57% and larvae aberration rate increased to 20-24% after As exposure. Moreover, thyroxine levels elevated by 23% and 50% at 100 μg L(-1) AsIII and 150 μg L(-1) AsV. Besides, AsIII and AsV decreased the transcriptional levels of TRα by 72 and 53%, and TRβ by 91 and 81% at 150 μg L(-1) As. Our data showed that AsIII and AsV had limited effect on carp embryo survival, but they were both toxic to carp larvae, with AsIII showing more effect than AsV. As concentrations <150μg L(-1) adversely influenced the development of bighead carp larvae and disturbed their thyroid hormone homeostasis. PMID:26513566

  14. Arsenic impacted the development, thyroid hormone and gene transcription of thyroid hormone receptors in bighead carp larvae (Hypophthalmichthys nobilis).

    PubMed

    Sun, Hong-Jie; Xiang, Ping; Tang, Ming-Hu; Sun, Li; Ma, Lena Q

    2016-02-13

    Arsenic (As) contamination in aquatic environment adversely impacts aquatic organisms. The present study assessed the toxicity of different As species and concentrations on bighead carp (Hypophthalmichthys nobilis) at early life stage, a major fish in Yangtze River, China. We measured the changes in embryo and larvae survival rate, larvae aberration, concentrations of thyroid hormone thyroxine, and transcription levels of thyroid hormone receptors (TRs) in fish larvae after exposing to arsenite (AsIII) or arsenate (AsV) at 0, 10, 30, 50, 100, or 150 μg L(-1) for 78 h. As concentrations ≤ 150 μg L(-1) had limited effect on embryo survival rate (6-8% inhibition), but larvae survival rate decreased to 53-57% and larvae aberration rate increased to 20-24% after As exposure. Moreover, thyroxine levels elevated by 23% and 50% at 100 μg L(-1) AsIII and 150 μg L(-1) AsV. Besides, AsIII and AsV decreased the transcriptional levels of TRα by 72 and 53%, and TRβ by 91 and 81% at 150 μg L(-1) As. Our data showed that AsIII and AsV had limited effect on carp embryo survival, but they were both toxic to carp larvae, with AsIII showing more effect than AsV. As concentrations <150μg L(-1) adversely influenced the development of bighead carp larvae and disturbed their thyroid hormone homeostasis.

  15. Gonadotropin-releasing hormone receptor system: modulatory role in aging and neurodegeneration.

    PubMed

    Wang, Liyun; Chadwick, Wayne; Park, Sung-Soo; Zhou, Yu; Silver, Nathan; Martin, Bronwen; Maudsley, Stuart

    2010-11-01

    Receptors for hormones of the hypothalamic-pituitary-gonadal axis are expressed throughout the brain. Age-related decline in gonadal reproductive hormones cause imbalances of this axis and many hormones in this axis have been functionally linked to neurodegenerative pathophysiology. Gonadotropin-releasing hormone (GnRH) plays a vital role in both central and peripheral reproductive regulation. GnRH has historically been known as a pituitary hormone; however, in the past few years, interest has been raised in GnRH actions at non-pituitary peripheral targets. GnRH ligands and receptors are found throughout the brain where they may act to control multiple higher functions such as learning and memory function and feeding behavior. The actions of GnRH in mammals are mediated by the activation of a unique rhodopsin-like G protein-coupled receptor that does not possess a cytoplasmic carboxyl terminal sequence. Activation of this receptor appears to mediate a wide variety of signaling mechanisms that show diversity in different tissues. Epidemiological support for a role of GnRH in central functions is evidenced by a reduction in neurodegenerative disease after GnRH agonist therapy. It has previously been considered that these effects were not via direct GnRH action in the brain, however recent data has pointed to a direct central action of these ligands outside the pituitary. We have therefore summarized the evidence supporting a central direct role of GnRH ligands and receptors in controlling central nervous physiology and pathophysiology.

  16. Dimeric Arrangement of the Parathyroid Hormone Receptor and a Structural Mechanism for Ligand-induced Dissociation

    SciTech Connect

    Pioszak, Augen A.; Harikumar, Kaleeckal G.; Parker, Naomi R.; Miller, Laurence J.; Xu, H. Eric

    2010-06-25

    The parathyroid hormone receptor (PTH1R) is a class B G protein-coupled receptor that is activated by parathyroid hormone (PTH) and PTH-related protein (PTHrP). Little is known about the oligomeric state of the receptor and its regulation by hormone. The crystal structure of the ligand-free PTH1R extracellular domain (ECD) reveals an unexpected dimer in which the C-terminal segment of both ECD protomers forms an {alpha}-helix that mimics PTH/PTHrP by occupying the peptide binding groove of the opposing protomer. ECD-mediated oligomerization of intact PTH1R was confirmed in living cells by bioluminescence and fluorescence resonance energy transfer experiments. As predicted by the structure, PTH binding disrupted receptor oligomerization. A receptor rendered monomeric by mutations in the ECD retained wild-type PTH binding and cAMP signaling ability. Our results are consistent with the hypothesis that PTH1R forms constitutive dimers that are dissociated by ligand binding and that monomeric PTH1R is capable of activating G protein.

  17. Anabolic action of parathyroid hormone regulated by the β2-adrenergic receptor.

    PubMed

    Hanyu, Ryo; Wehbi, Vanessa L; Hayata, Tadayoshi; Moriya, Shuichi; Feinstein, Timothy N; Ezura, Yoichi; Nagao, Masashi; Saita, Yoshitomo; Hemmi, Hiroaki; Notomi, Takuya; Nakamoto, Tetsuya; Schipani, Ernestina; Takeda, Shu; Kaneko, Kazuo; Kurosawa, Hisashi; Karsenty, Gerard; Kronenberg, Henry M; Vilardaga, Jean-Pierre; Noda, Masaki

    2012-05-01

    Parathyroid hormone (PTH), the major calcium-regulating hormone, and norepinephrine (NE), the principal neurotransmitter of sympathetic nerves, regulate bone remodeling by activating distinct cell-surface G protein-coupled receptors in osteoblasts: the parathyroid hormone type 1 receptor (PTHR) and the β(2)-adrenergic receptor (β(2)AR), respectively. These receptors activate a common cAMP/PKA signal transduction pathway mediated through the stimulatory heterotrimeric G protein. Activation of β(2)AR via the sympathetic nervous system decreases bone formation and increases bone resorption. Conversely, daily injection of PTH (1-34), a regimen known as intermittent (i)PTH treatment, increases bone mass through the stimulation of trabecular and cortical bone formation and decreases fracture incidences in severe cases of osteoporosis. Here, we show that iPTH has no osteoanabolic activity in mice lacking the β(2)AR. β(2)AR deficiency suppressed both iPTH-induced increase in bone formation and resorption. We showed that the lack of β(2)AR blocks expression of iPTH-target genes involved in bone formation and resorption that are regulated by the cAMP/PKA pathway. These data implicate an unexpected functional interaction between PTHR and β(2)AR, two G protein-coupled receptors from distinct families, which control bone formation and PTH anabolism. PMID:22538810

  18. Allosteric receptor activation by the plant peptide hormone phytosulfokine.

    PubMed

    Wang, Jizong; Li, Hongju; Han, Zhifu; Zhang, Heqiao; Wang, Tong; Lin, Guangzhong; Chang, Junbiao; Yang, Weicai; Chai, Jijie

    2015-09-10

    Phytosulfokine (PSK) is a disulfated pentapeptide that has a ubiquitous role in plant growth and development. PSK is perceived by its receptor PSKR, a leucine-rich repeat receptor kinase (LRR-RK). The mechanisms underlying the recognition of PSK, the activation of PSKR and the identity of the components downstream of the initial binding remain elusive. Here we report the crystal structures of the extracellular LRR domain of PSKR in free, PSK- and co-receptor-bound forms. The structures reveal that PSK interacts mainly with a β-strand from the island domain of PSKR, forming an anti-β-sheet. The two sulfate moieties of PSK interact directly with PSKR, sensitizing PSKR recognition of PSK. Supported by biochemical, structural and genetic evidence, PSK binding enhances PSKR heterodimerization with the somatic embryogenesis receptor-like kinases (SERKs). However, PSK is not directly involved in PSKR-SERK interaction but stabilizes PSKR island domain for recruitment of a SERK. Our data reveal the structural basis for PSKR recognition of PSK and allosteric activation of PSKR by PSK, opening up new avenues for the design of PSKR-specific small molecules.

  19. Lessons learned from studies with the growth hormone receptor.

    PubMed

    Kopchick, John J

    2016-06-01

    Findings related to GH's biological activities have continued to be a fascinating topic over the past decade. Below, I will review several items related to the actions of GH including the GH/GHR interaction, pegvisomant (a GH receptor antagonist), GHR gene disruptions in mice, and clinical consequences of human GHR gene mutations. PMID:26216709

  20. Normal Morphology and Hormone Receptor Expression in the Male California sea lion (Zalophus californianus) Genital Tract

    PubMed Central

    Colegrove, Kathleen M.; Gulland, Frances M. D.; Naydan, Diane K.; Lowenstine, Linda J.

    2010-01-01

    Histomorphology and estrogen α (ER α), and progesterone receptor (PR) expression were evaluated in free-ranging stranded male California sea lions (Zalophus californianus). Hormone receptor expression was evaluated using an immunohistochemical technique with monoclonal antibodies. Estrogen and progesterone receptors were identified in the efferent ductules, prostate gland, corpus cavernosa, corpus spongiosium, penile urethra, and in the epithelium and stroma of both the penis and prepuce. In the some tissues, ER α expression was more intense in the stroma, emphasizing the importance of the stroma in hormone – mediated growth and differentiation of reproductive organs. To our knowledge, this is the first study to localize ER α and PR to the epithelium of the glans penis. The results of this investigation add to the general knowledge of male California sea lion reproduction and suggest that estrogens could have a role in the function of the male reproductive tract. PMID:19768750

  1. Follicle-stimulating hormone interacts with exoloop 3 of the receptor.

    PubMed

    Sohn, Johann; Ryu, KiSung; Sievert, Gail; Jeoung, MyoungKun; Ji, Inhae; Ji, Tae H

    2002-12-20

    The human follicle-stimulating hormone (FSH) receptor consists of two distinct domains of approximately 330 amino acids, the N-terminal extracellular exodomain and membrane-associated endodomain including three exoloops and seven transmembrane helices. The exodomain binds the hormone with high affinity, and the resulting hormone/exodomain complex modulates the endodomain where receptor activation occurs. It has been an enigma whether the hormone interacts with the endodomain. In a step to address the question, exoloop 3 of (580)KVPLITVSKAK(590) was examined by Ala scan, multiple substitution, assays for hormone binding, cAMP and inositol phosphate (IP) induction, and photoaffinity labeling. We present the evidence for the interaction of FSH and exoloop 3. A peptide mimic of exoloop 3 specifically and saturably photoaffinity-labels FSH alpha but not FSH beta. This is in contrast to photoaffinity labeling of FSH beta by the peptide mimic of the N-terminal region of the receptor. Leu(583) and Ile(584) are crucial for the interaction of FSH and exoloop 3. Substitutions of these two residues enhanced the hormone binding affinity. This is due to the loss of the original side chains but not the introduction of new side chains. The Leu(583) and Ile(584) side chains appear to project in opposite directions. Ile(584) appears to be so specific and to require flexibility and stereo specificity so that no other amino acids can fit into its place. Leu(583) is less specific. The improvement in hormone binding by substitutions was offset by the severe impairment of signal generation of cAMP and/or inositol phosphate. For example, the Phe or Tyr substitution of Leu(583) improved the hormone binding and cAMP induction but impaired IP induction. On the other hand, the substitutions for Ile(584) and Lys(590) abolished the cAMP and IP induction. Our results open a logical question whether Leu(583), Ile(584), and Lys(590) interact with the exodomain and/or the hormone. The answers will

  2. Targeting the Diuretic Hormone Receptor to Control the Cotton Leafworm, Spodoptera littoralis

    PubMed Central

    Apone, Fabio; Ruggiero, Alessandra; Tortora, Assunta; Tito, Annalisa; Grimaldi, Maria Rosaria; Arciello, Stefania; Andrenacci, Davide; Lelio, Ilaria Di; Colucci, Gabriella

    2014-01-01

    The cotton leafworm, Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae), is one of the most devastating pests of crops worldwide. Several types of treatments have been used against this pest, but many of them failed because of the rapid development of genetic resistance in the different insect populations. G protein coupled receptors have vital functions in most organisms, including insects; thus, they are appealing targets for species-specific pest control strategies. Among the insect G protein coupled receptors, the diuretic hormone receptors have several key roles in development and metabolism, but their importance in vivo and their potential role as targets of novel pest control strategies are largely unexplored. With the goal of using DHR genes as targets to control S. littoralis, we cloned a corticotropin-releasing factor-like binding receptor in this species and expressed the corresponding dsRNA in tobacco plants to knock down the receptor activity in vivo through RNA interference. We also expressed the receptor in mammalian cells to study its signaling pathways. The results indicate that this diuretic hormone receptor gene has vital roles in S. littoralis and represents an excellent molecular target to protect agriculturallyimportant plants from this pest. PMID:25368043

  3. Expression of a glycosylphosphatidylinositol-anchored ligand, growth hormone, blocks receptor signalling

    PubMed Central

    Guesdon, François; Kaabi, Yahia; Riley, Aiden H.; Wilkinson, Ian R.; Gray, Colin; James, David C.; Artymiuk, Peter J.; Sayers, Jon R.; Ross, Richard J.

    2012-01-01

    We have investigated the interaction between GH (growth hormone) and GHR (GH receptor). We previously demonstrated that a truncated GHR that possesses a transmembrane domain but no cytoplasmic domain blocks receptor signalling. Based on this observation we investigated the impact of tethering the receptor's extracellular domain to the cell surface using a native lipid GPI (glycosylphosphatidylinositol) anchor. We also investigated the effect of tethering GH, the ligand itself, to the cell surface and demonstrated that tethering either the ecGHR (extracellular domain of GHR) or the ligand itself to the cell membrane via a GPI anchor greatly attenuates signalling. To elucidate the mechanism for this antagonist activity, we used confocal microscopy to examine the fluorescently modified ligand and receptor. GH–GPI was expressed on the cell surface and formed inactive receptor complexes that failed to internalize and blocked receptor activation. In conclusion, contrary to expectation, tethering an agonist to the cell surface can generate an inactive hormone receptor complex that fails to internalize. PMID:23013472

  4. Properties of follicle-stimulating-hormone receptor in cell membranes of bovine testis.

    PubMed Central

    Cheng, K W

    1975-01-01

    A simple method for preparing plasma membranes from bovine testes is described. Bovine testicular receptor has a high affinity and specificity for 125I-labelled human FSH (follicle-stimulating hormone). The specific binding of 125I-labelled human FSH to the plasma membranes is a saturable process with respect to the amounts of receptor protein and FSH added. The association and dissociation of 125I-labelled human FSH are time- and temperature-dependent, and the binding of labelled human FSH to bovine testicular receptor is strong and not readily reversible. Scatchard [Ann. N.Y. Acad. Sci. (1949) 51, 660-672] analysis indicates a dissociation constant, Kd, of 9.8 X10(-11)M, and 5.9 X 10(-14)mol of binding sites/mg of membrane protein. The testicular membrane receptor is heat-labile. Preheating at 40 degrees C for 15 min destroyed 30% of the binding activity. Specific binding is pH-dependent, with an optimum between pH 7.0 and 7.5. Brief exposure to extremes of pH caused irreversible damage to the receptors. The ionic strength of the incubation medium markedly affects the association of 125I-labelled human FSH with its testicular receptor. Various cations at concentrations of 0.1M inhibit almost completely the binding of 125I-labelled human FSH. Nuclectides and steroid hormones at concentrations of 1mM and 5mu/ml respectively have no effect on the binding of FSH to its receptor. Incubation of membranes with and chymotrypsin resulted in an almost complete loss of binding activity, suggesting that protein moieties are essential for the binding of 125I-labelled human FSH. Binding of 125I-labelled human FSH to bovine testicular receptor does not result in destruction or degradation of the hormone. PMID:242318

  5. Glycoprotein Hormones and Their Receptors Emerged at the Origin of Metazoans

    PubMed Central

    Roch, Graeme J.; Sherwood, Nancy M.

    2014-01-01

    The cystine knot growth factor (CKGF) superfamily includes important secreted developmental regulators, including the families of transforming growth factor beta, nerve growth factor, platelet-derived growth factor, and the glycoprotein hormones (GPHs). The evolutionary origin of the GPHs and the related invertebrate bursicon hormone, and their characteristic receptors, contributes to an understanding of the endocrine system in metazoans. Using a sensitive search method with hidden Markov models, we identified homologs of the hormones and receptors, along with the closely related bone morphogenetic protein (BMP) antagonists in basal metazoans. In sponges and a comb jelly, cystine knot hormones (CKHs) with mixed features of GPHs, bursicon, and BMP antagonists were identified using primary sequence and phylogenetic analysis. Also, we identified potential receptors for these CKHs, leucine-rich repeat-containing G protein-coupled receptors (LGRs), in the same species. Cnidarians, such as the sea anemone, coral, and hydra, diverged later in metazoan evolution and appear to have duplicated and differentiated CKH-like peptides resulting in bursicon/GPH-like peptides and several BMP antagonists: Gremlin (Grem), sclerostin domain containing (SOSD), neuroblastoma suppressor of tumorigenicity 1 (NBL1), and Norrie disease protein. An expanded cnidarian LGR group also evolved, including receptors for GPH and bursicon. With the appearance of bilaterians, a separate GPH (thyrostimulin) along with bursicon and BMP antagonists were present. Synteny indicates that the GPHs, Grem, and SOSD have been maintained in a common gene neighborhood throughout much of metazoan evolution. The stable and highly conserved CKGFs are not identified in nonmetazoan organisms but are established with their receptors in the basal metazoans, becoming critical to growth, development, and regulation in all animals. PMID:24904013

  6. Prognostic Value of Sex-Hormone Receptor Expression in Non-Muscle-Invasive Bladder Cancer

    PubMed Central

    Park, Sung Woo; Lee, Sang Don; Chung, Moon Kee

    2014-01-01

    Purpose We investigated sex-hormone receptor expression as predicting factor of recurrence and progression in patients with non-muscle invasive bladder cancer. Materials and Methods 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. Results 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. Conclusion 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. PMID:25048477

  7. Rational Design of Potent Antagonists to the Human Growth Hormone Receptor

    NASA Astrophysics Data System (ADS)

    Fuh, Germaine; Cunningham, Brian C.; Fukunaga, Rikiro; Nagata, Shigekazu; Goeddel, David V.; Wells, James A.

    1992-06-01

    A hybrid receptor was constructed that contained the extracellular binding domain of the human growth hormone (hGH) receptor linked to the transmembrane and intracellular domains of the murine granulocyte colony-stimulating factor receptor. Addition of hGH to a myeloid leukemia cell line (FDC-P1) that expressed the hybrid receptor caused proliferation of these cells. The mechanism for signal transduction of the hybrid receptor required dimerization because monoclonal antibodies to the hGH receptor were agonists whereas their monovalent fragments were not. Receptor dimerization occurs sequentially-a receptor binds to site 1 on hGH, and then a second receptor molecule binds to site 2 on hGH. On the basis of this sequential mechanism, which may occur in many other cytokine receptors, inactive hGH analogs were designed that were potent antagonists to hGH-induced cell proliferation. Such antagonists could be useful for treating clinical conditions of hGH excess, such as acromegaly.

  8. Skeletal receptors for steroid-family regulating glycoprotein hormones: A multilevel, integrated physiological control system.

    PubMed

    Blair, Harry C; Robinson, Lisa J; Sun, Li; Isales, Carlos; Davies, Terry F; Zaidi, Mone

    2011-12-01

    Pituitary glycoprotein hormone receptors, including ACTH-R, TSH-R, and FSH-R, occur in bone. Their skeletal expression reflects that central endocrine control is evolutionarily recent. ACTH receptors, in osteoblasts or the adrenal cortex, drive VEGF synthesis. VEGF is essential to maintain vasculature. In bone, ACTH suppression by glucocorticoids can cause osteonecrosis. TSH receptors occur on osteoblasts and osteoclasts, in both cases reducing activity. Thus, TSH directly reduces skeletal turnover, consistent with evolutionary adaptation to stress. FSH receptors accelerate bone resorption, whereas estrogen promotes bone formation, the forces usually balancing. With ovarian failure, low estrogen with high FSH causes rapid bone loss. The skeletal FSH effect in the menopause seems paradoxical, but it is a logical adaptation in lactation, where prolonged FSH elevation also occurs. In addition to receptors, there is some synthesis of pituitary glycoproteins at distributed sites; this is not well studied, but it may further modify the paradigm of central endocrine regulation.

  9. Autoinduction of thyroid hormone receptor during metamorphosis is reproduced in Xenopus XTC-2 cells.

    PubMed

    Machuca, I; Tata, J R

    1992-09-01

    To determine if the autoinduction of thyroid hormone receptor (TR) alpha and beta mRNAs during metamorphosis in Xenopus tadpoles can be reproduced in cultured cells, we have screened four Xenopus cell lines (XTC-2, XL-177, XL2 and Kr) for receptor transcripts and their response to thyroid hormone. Exposure of XTC-2 cells to 10(-9) M triiodothyronine (T3) for 24 h upregulated TR alpha and beta mRNAs by 2-4- and 10-40-fold, respectively. In view of the marked similarity of the differential distribution of the two transcripts and their upregulation by T3 to the pattern of autoinduction seen in whole tadpoles, the process was studied in greater detail in XTC-2 cells. The time-course of autoinduction of TR alpha and beta mRNAs in these cells also resembled that in vivo, the two transcripts being significantly induced by 3-6 h after T3. Dose-response to T3, and the relative responses to its active and inactive analogs, confirmed that the process of autoinduction was initiated by thyroid hormone receptor with the same functional characteristics as that found in all amphibian and mammalian tissues. Experiments performed with cycloheximide suggested that intermediary protein(s) were involved in autoinduction, so that TR genes cannot be considered as 'immediate early' genes for this process. The possible advantages of studying thyroid hormone action in metamorphosis in XTC-2 cells are briefly discussed.

  10. Research into Specific Modulators of Vascular Sex Hormone Receptors in the Management of Postmenopausal Cardiovascular Disease

    PubMed Central

    do Nascimento, Graciliano R. A.; Barros, Yaskara V. R.; Wells, Amanda K.; Khalil, Raouf A.

    2010-01-01

    Cardiovascular disease (CVD) is more common in men and postmenopausal women than premenopausal women, suggesting vascular benefits of female sex hormones. Studies on the vasculature have identified estrogen receptors ERα, ERβ and a novel estrogen binding membrane protein GPR30, that mediate genomic and/or non-genomic effects. Estrogen promotes endothelium-dependent relaxation by inducing the production/activity of nitric oxide, prostacyclin, and hyperpolarizing factor, and inhibits the mechanisms of vascular smooth muscle contraction including [Ca2+]i, protein kinase C, Rho kinase and mitogen-activated protein kinase. Additional effects of estrogen on the cytoskeleton, matrix metalloproteinases and inflammatory factors contribute to vascular remodeling. However, the experimental evidence did not translate into vascular benefits of menopausal hormone therapy (MHT), and the HERS, HERS-II and WHI clinical trials demonstrated adverse cardiovascular events. The discrepancy has been partly related to delayed MHT and potential changes in the vascular ER amount, integrity, affinity, and downstream signaling pathways due to the subjects' age and preexisting CVD. The adverse vascular effects of MHT also highlighted the need of specific modulators of vascular sex hormone receptors. The effectiveness of MHT can be improved by delineating the differences in phramcokinetics and pharmacodynamics of natural, synthetic, and conjugated equine estrogens. Estriol, “hormone bioidenticals” and phytoestrogens are potential estradiol substitutes. The benefits of low dose MHT, and transdermal or vaginal estrogens over oral preparations are being evaluated. Specific ER modulators (SERMs) and ER agonists are being developed to maximize the effects on vascular ERs. Also, the effects of estrogen are being examined in the context of the whole body hormonal environment and the levels of progesterone and androgens. Thus, the experimental vascular benefits of estrogen can be translated to

  11. The mitochondrion as a primary site of action of steroid and thyroid hormones: presence and action of steroid and thyroid hormone receptors in mitochondria of animal cells.

    PubMed

    Psarra, A-M G; Solakidi, S; Sekeris, C E

    2006-02-26

    Mitochondria are key cellular organelles that regulate events related to energy production and apoptosis. These processes are modulated, in turn, by steroid and thyroid hormones in the course of their actions on metabolism, growth and development. In this context, a direct effect of these hormones on the mitochondrial-linked processes, possibly by way of cognate mitochondrial receptors, has been proposed. In this paper we review data from the literature and present new findings supporting this concept. Receptors for steroid hormones, glucocorticoids and estrogens, and for T(3), have been detected in mitochondria by immunofluorescence labeling and confocal laser microscopy, by Western blotting of mitochondrial proteins and by immunogold electron microscopy. Furthermore, the mitochondrial genome contains nucleotide sequences with high similarity to known hormone-responsive elements, which interact with the appropriate receptors to confer hormone-dependent activation of reporter genes in transfection experiments. Thus, thyroid hormone stimulates mitochondrial transcription mediated by the cognate receptor when added to an in organello mitochondrial system, capable of faithful transcription.

  12. Constitutive negative regulation in the processing of the anti-Müllerian hormone receptor II.

    PubMed

    Hirschhorn, Tal; di Clemente, Nathalie; Amsalem, Ayelet R; Pepinsky, R Blake; Picard, Jean-Yves; Smorodinsky, Nechama I; Cate, Richard L; Ehrlich, Marcelo

    2015-04-01

    The levels and intracellular localization of wild-type transforming growth factor β superfamily (TGFβ-SF) receptors are tightly regulated by endocytic trafficking, shedding and degradation. In contrast, a main regulatory mechanism of mutation-bearing receptors involves their intracellular retention. Anti-Müllerian hormone receptor II (AMHRII, also known as AMHR2) is the type-II receptor for anti-Müllerian hormone (AMH), a TGFβ-SF ligand that mediates Müllerian duct regression in males. Here, we studied AMHRII processing and identified novel mechanisms of its constitutive negative regulation. Immunoblot analysis revealed that a significant portion of AMHRII was missing most of its extracellular domain (ECD) and, although glycosylated, was unfolded and retained in the endoplasmic reticulum. Exogenous expression of AMHRII, but not of type-II TGF-β receptor (TβRII, also known as TGFR2), resulted in its disulfide-bond-mediated homo-oligomerization and intracellular retention, and in a decrease in its AMH-binding capacity. At the plasma membrane, AMHRII differed from TβRII, forming high levels of non-covalent homomeric complexes, which exhibited a clustered distribution and restricted lateral mobility. This study identifies novel mechanisms of negative regulation of a type-II TGFβ-SF receptor through cleavage, intracellular retention and/or promiscuous disulfide-bond mediated homo-oligomerization.

  13. Parathyroid hormone ablation alters erythrocyte parameters that are rescued by calcium-sensing receptor gene deletion.

    PubMed

    Romero, Jose R; Youte, Rodeler; Brown, Edward M; Pollak, Martin R; Goltzman, David; Karaplis, Andrew; Pong, Lie-Chin; Chien, Lawrence; Chattopadhyay, Naibedya; Rivera, Alicia

    2013-07-01

    The mechanisms by which parathyroid hormone (PTH) produces anemia are unclear. Parathyroid hormone secretion is regulated by the extracellular Ca2+ -sensing receptor. We investigated the effects of ablating PTH on hematological indices and erythrocytes volume regulation in wild-type, PTH-null, and Ca2+ -sensing receptor-null/PTH-null mice. The erythrocyte parameters were measured in whole mouse blood, and volume regulatory systems were determined by plasma membrane K+ fluxes, and osmotic fragility was measured by hemoglobin determination at varying osmolarities. We observed that the absence of PTH significantly increases mean erythrocyte volume and reticulocyte counts, while decreasing erythrocyte counts, hemoglobin, hematocrit, and mean corpuscular hemoglobin concentration. These changes were accompanied by increases in erythrocyte cation content, a denser cell population, and increased K+ permeability, which were in part mediated by activation of the K+ /Cl- cotransporter and Gardos channel. In addition we observed that erythrocyte osmotic fragility in PTH-null compared with wild-type mice was enhanced. When Ca2+ -sensing receptor gene was deleted on the background of PTH-null mice, we observed that several of the alterations in erythrocyte parameters of PTH-null mice were largely rescued, particularly those related to erythrocyte volume, K+ fluxes and osmotic fragility, and became similar to those observed in wild-type mice. Our results demonstrate that Ca2+ -sensing receptor and parathyroid hormone are functionally coupled to maintain erythrocyte homeostasis. PMID:23528155

  14. Site-specific basicities regulate molecular recognition in receptor binding: in silico docking of thyroid hormones.

    PubMed

    Tóth, Gergő; Baska, Ferenc; Schretner, András; Rácz, Akos; Noszál, Béla

    2013-09-01

    Interactions between thyroid hormone α and β receptors and the eight protonation microspecies of each of the main thyroid hormones (thyroxine, liothyronine, and reverse liothyronine) were investigated and quantitated by molecular modeling. Flexible docking of the various protonation forms of thyroid hormones and high-affinity thyromimetics to the two thyroid receptors was carried out. In this method the role of the ionization state of each basic site could be studied in the composite process of molecular recognition. Our results quantitate at the molecular level how the ionization state and the charge distribution influence the protein binding. The anionic form of the carboxyl group (i.e., carboxylate site) is essential for protein binding, whereas the protonated form of amino group worsens the binding. The protonation state of the phenolate plays a less important role in the receptor affinity; its protonation, however, alters the electron density and the concomitant stacking propensity of the aromatic rings, resulting in a different binding score. The combined results of docking and microspeciation studies show that microspecies with the highest concentration at the pH of blood are not the strongest binding ones. The calculated binding free energy values can be well interpreted in terms of the interactions between the actual sites of the microspecies and the receptor amino acids. Our docking results were validated and compared with biological data from the literature. Since the thyroid hormone receptors influence several physiologic functions, such as metabolic rate, cholesterol and triglyceride levels, and heart frequency, our binding results provide a molecular basis for drug design and development in related therapeutic indications. PMID:23907234

  15. Identification of Neuropeptide Receptors Expressed by Melanin-Concentrating Hormone Neurons

    PubMed Central

    Parks, Gregory S.; Wang, Lien; Wang, Zhiwei; Civelli, Olivier

    2014-01-01

    Melanin-concentrating Hormone (MCH) is a 19 amino acid cyclic neuropeptide that acts in rodents via the MCH receptor 1 (MCHR1) to regulate a wide variety of physiological functions. MCH is produced by a distinct population of neurons located in the lateral hypothalamus (LH) and zona incerta (ZI) but MCHR1 mRNA is widely expressed throughout the brain. The physiological responses and behaviors regulated by the MCH system have been investigated, but less is known about how MCH neurons are regulated. The effects of most classical neurotransmitters on MCH neurons have been studied, but those of neuropeptides are poorly understood. In order to gain insight into how neuropeptides regulate the MCH system, we investigated which neuropeptide receptors are expressed by MCH neurons using double in situ hybridization. In all, twenty receptors, selected based upon either a suspected interaction with the MCH system or demonstrated high expression levels in the LH and ZI, were tested to determine whether they are expressed by MCH neurons. Overall, eleven neuropeptide receptors were found to exhibit significant colocalization with MCH neurons: Nociceptin / Orphanin FQ Opioid receptor (NOP), MCHR1, both Orexin receptors (ORX), Somatostatin receptor 1 and 2 (SSTR1, SSTR2), the Kisspeptin receotor (KissR1), Neurotensin receptor 1 (NTSR1), Neuropeptide S receptor (NPSR), Cholecystokinin receptor A (CCKAR) and the κ-opioid receptor (KOR). Of these receptors, six have never before been linked to the MCH system. Surprisingly, several receptors thought to regulate MCH neurons displayed minimal colocalization with MCH, suggesting that they may not directly regulate the MCH system. PMID:24978951

  16. Growth hormone receptor antagonists: discovery and potential uses.

    PubMed

    Kopchick, J J; Okada, S

    2001-06-01

    Serum levels of growth hormone (GH) in the human body vary and can influence the levels of insulin-like growth factor I (IGF-1). Low levels of GH can result in a dwarf phenotype and have been positively correlated with an increased life expectancy. High levels of GH can lead to gigantism or a clinical syndrome termed acromegaly, and also have been implicated in diabetic eye and kidney damage. Additionally, it has been postulated that the GH-IGF-I system can be involved in several types of cancers. Overall, both elevated and suppressed circulating levels of GH can have pronounced physiological effects. More than a decade ago a new class of drug, a GH antagonist, was discovered. It is now being tested for its ability to combat the effects of high circulating levels of GH. In this review, we will discuss some of the detrimental actions of GH and how a GH antagonist may be used to combat these effects. PMID:11527080

  17. Ovarian hormones influence corticotropin releasing factor receptor colocalization with delta opioid receptors in CA1 pyramidal cell dendrites

    PubMed Central

    Williams, Tanya J.; Akama, Keith T.; Knudsen, Margarete G.; McEwen, Bruce S.; Milner, Teresa A.

    2011-01-01

    receptor-ir colocalization with DOR-ir in the same neuron using the hormone responsive neuronal cell line NG108-15, which endogenously express DORs, and assayed intracellular cAMP production in response to CRF receptor and DOR agonists. Results demonstrated that short-term application of DOR agonist SNC80 inhibited CRF-induced cAMP accumulation in NG108-15 cells transfected with the CRF receptor. These studies provide new insights on opioid-stress system interaction in the hippocampus of both males and females and establish potential mechanisms through which DOR activation may influence CRF receptor activity. PMID:21549703

  18. Impact of growth hormone resistance on female reproductive function: new insights from growth hormone receptor knockout mice.

    PubMed

    Zaczek, Denise; Hammond, James; Suen, Lii; Wandji, Serge; Service, Darlene; Bartke, Andrzej; Chandrashekar, Varadaraj; Coschigano, Karen; Kopchick, John

    2002-10-01

    We examined multiple aspects of reproductive function in growth hormone receptor gene knockout (GHR-KO) and normal mice to clarify the role of growth hormone in female reproduction. In adult animals, estrous cycle duration was comparable in all mice housed individually but was significantly longer in group-housed GHR-KO females. Histological evaluation of ovaries of adult females at estrus showed that the numbers of preovulatory follicles and corpora lutea were significantly reduced in GHR-KO mice, as was the plasma estradiol level. The number of atretic preovulatory follicles was reduced in GHR gene-ablated animals. Although reverse transcription polymerase chain reaction analysis revealed reduced ovarian insulin-like growth factor I (IGF-I) mRNA expression in GHR-KO females, the expression of several steroidogenic enzyme mRNAs did not differ between groups. The numbers of active corpora lutea and uterine implantation sites were reduced in GHR-KO females at Day 7 of gestation. When young females were mated to normal males, latency to first mating and age of the female at first mating were significantly delayed in GHR-KO females, but maternal age at first conception was similar between groups. Significantly fewer virgin GHR-KO females exhibited pseudopregnancies when initially placed with vasectomized normal males than did normal female counterparts. Growth hormone resistance and IGF-I insufficiency negatively impacted 1) follicular development/ovulation rate, 2) sexual maturation, 3) production of and responsiveness to pheromonal signals, and 4) the ability of virgin females to respond to coitus by activation of luteal function. Although GHR-KO female mice are fertile, they exhibit quantitative deficits in various parameters of reproductive function.

  19. Older individuals heterozygous for a growth hormone-releasing hormone receptor gene mutation are shorter than normal subjects.

    PubMed

    Aguiar-Oliveira, Manuel H; Cardoso-Filho, Marco A; Pereira, Rossana M C; Oliveira, Carla R P; Souza, Anita H O; Santos, Elenilde G; Campos, Viviane C; Valença, Eugênia H O; de Oliveira, Francielle T; Oliveira-Neto, Luiz A; Gois-Junior, Miburge B; Oliveira-Santos, Alecia A; Salvatori, Roberto

    2015-06-01

    Growth hormone (GH)-releasing hormone (GHRH) is the most important stimulus for GH secretion by the pituitary gland. Subjects homozygous for GHRH receptor (GHRHR) gene (GHRHR) inactivating mutations have severe GH deficiency, resulting in severe short stature if not treated. We previously reported that young adults heterozygous for the c.57+1G>A null GHRHR mutation (MUT/N) have reduced weight and body mass index (BMI) but normal stature. Here we have studied whether older MUT/N have an additional phenotype. In a cross-sectional study, we measured height, weight and blood pressure, and calculated BMI in two groups (young, 20-40 years of age) and old (60-80 years) of individuals heterozygous for the same GHRHR mutation, and compared with a large number of individuals of normal genotype residing in the same geographical area. Standard deviation score (SDS) of weight was lower, and BMI had a trend toward reduction in young heterozygous compared with young normals, without significant difference in stature. Conversely, SDS of height was lower in older heterozygous individuals than in controls, corresponding to a reduction of 4.2 cm. These data show a reduced stature in older subjects heterozygous for the c.57+1G>A GHRHR mutation, indicating different effects of heterozygosis through lifespan. PMID:25761575

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

    PubMed

    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. PMID:24099797

  1. Estrogen, Vascular Estrogen Receptor and Hormone Therapy in Postmenopausal Vascular Disease

    PubMed Central

    Khalil, Raouf A.

    2013-01-01

    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. PMID:24099797

  2. Identification of intracellular domains in the growth hormone receptor involved in signal transduction

    SciTech Connect

    Billestrup, N.; Allevato, G.; Moldrup, A.

    1994-12-31

    The growth hormone (GH) receptor belongs to the GH/prolactin/cytokine super-family of receptors. The signal transduction mechanism utilized by this class of receptors remains largely unknown. In order to identify functional domains in the intracellular region of the GH receptor we generated a number of GH receptor mutants and analyzed their function after transfection into various cell lines. A truncated GH receptor missing 184 amino acids at the C-terminus was unable to medite GH effects on transcription of the Spi 2.1 and insulin genes. However, this mutant was fully active in mediating GH-stimulated metabolic effects such as protein synthesis and lipolysis. Furthermore, this mutant GH receptor internalized rapidly following GH binding. Another truncated GH receptor lacking all but five amino acids of the cytoplasmic domain could not mediate any effects of GH nor did it internalize. Deletion of the proline-rich region or changing the four prolines to alanines also resulted in a GH receptor deficient in signaling. Mutation of phenylalanine 346 to alanine resulted in a GH receptor which did not internalize rapidly; however, this mutant GH receptor was capable of mediating GH-stimulated transcription as well as metabolic effects. These results indicate that the intracellular part of the GH receptor can be divided into at least three functional domains: (1) for transcriptional activity, two domains are involved, one located in the C-terminal 184 amino acids and the other in the proline-rich domain; (2) for metabolic effects, a domain located in or near the proline-rich region is of importance; and (3) for internalization, phenylalanine 346 is necessary. 28 refs., 1 fig.

  3. ELABELA: a hormone essential for heart development signals via the apelin receptor.

    PubMed

    Chng, Serene C; Ho, Lena; Tian, Jing; Reversade, Bruno

    2013-12-23

    We report here the discovery and characterization of a gene, ELABELA (ELA), encoding a conserved hormone of 32 amino acids. Present in human embryonic stem cells, ELA is expressed at the onset of zebrafish zygotic transcription and is ubiquitous in the naive ectodermal cells of the embryo. Using zinc-finger-nuclease-mediated gene inactivation in zebrafish, we created an allelic series of ela mutants. ela null embryos have impaired endoderm differentiation potential marked by reduced gata5 and sox17 expression. Loss of Ela causes embryos to develop with a rudimentary heart or no heart at all, surprisingly phenocopying the loss of the apelin receptor (aplnr), which we show serves as Ela's cognate G protein-coupled receptor. Our results reveal the existence of a peptide hormone, ELA, which, together with APLNR, forms an essential signaling axis for early cardiovascular development.

  4. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    PubMed

    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.

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

    PubMed Central

    Plewka, Danuta; Marczyński, Jacek; Morek, Michał; Bogunia, Edyta

    2014-01-01

    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. PMID:25050358

  6. Evolution of physicochemical properties of melanin concentrating hormone receptor 1 (MCHr1) antagonists.

    PubMed

    Johansson, Anders

    2016-10-01

    One pharmacological principle for the treatment of obesity is blockade of the melanin concentrating hormone receptor 1 (MCHr1), which in rodents has been shown to be strongly associated with food intake and energy expenditure. However, discovery of safe and efficacious MCHr1 antagonists has proved to be complex. So far, six compounds have been progressed into clinical trials, but clinical validation of the concept is still lacking. An account of discovery of the three most recent clinical candidates targeting the MCHr1 receptor is given, with an emphasis on their physicochemical properties.

  7. Evolution of physicochemical properties of melanin concentrating hormone receptor 1 (MCHr1) antagonists.

    PubMed

    Johansson, Anders

    2016-10-01

    One pharmacological principle for the treatment of obesity is blockade of the melanin concentrating hormone receptor 1 (MCHr1), which in rodents has been shown to be strongly associated with food intake and energy expenditure. However, discovery of safe and efficacious MCHr1 antagonists has proved to be complex. So far, six compounds have been progressed into clinical trials, but clinical validation of the concept is still lacking. An account of discovery of the three most recent clinical candidates targeting the MCHr1 receptor is given, with an emphasis on their physicochemical properties. PMID:27595423

  8. Investigations of receptor-mediated phagocytosis by hormone-induced (imprinted) Tetrahymena pyriformis.

    PubMed

    Kovács, P; Sundermann, C A; Csaba, G

    1996-08-15

    Receptor-mediated endocytosis by Tetrahvmena pyriformis was studied using tetramethylrhodamine isothiocyanate-labeled concanavalin A (TRITC-Con A) with fluorescence and confocal microscopy. In the presence of insulin, or 24 h after insulin pretreatment (hormonal imprinting), the binding and uptake of TRITC-Con A increased when compared to controls, owing to the binding of TRITC-Con A to sugar oligomers of insulin receptors. Mannose inhibited the binding of Con A, thus demonstrating the specificity of binding. Histamine, a phagocytosis-promoting factor in mammals and Tetrahymena, and galactose, did not influence the uptake of TRITC-Con A.

  9. Steroid hormone receptors in cancer development: a target for cancer therapeutics.

    PubMed

    Ahmad, Nihal; Kumar, Raj

    2011-01-01

    The steroid hormone receptors (SHRs) are ligand-dependent intracellular transcription factors that are known to influence the development and growth of many human cancers. SHRs pass signals from a steroid/hormone to the target genes by interacting with specific response element DNA sequences and various coregulatory proteins that consists of activators and/or corepressors. Disruptions in physiological functions of SHRs leads to several types of malignancies such as breast cancer, leukemia and lymphoma, prostate cancer, ovarian cancer, and lung cancer among others. Steroids/hormones/SHRs and their coregulators have opened up a unique window for novel steroid-based targeted therapies for cancer. Thus, dysregulation of SHR signaling in cancers compared with normal tissues can be exploited to target drugs that prevent and treat human cancers. In recent years, hormonal therapy has made a major contribution to the treatment of several cancers including reduced recurrence rates and longer survival rates. Development of various steroid receptor modulators and their potential therapeutic efficacies has provided us a great opportunity to effectively manage diseases like cancer in future. In this review article, we have summarized up-to-date knowledge of the role of SHRs in the development and progression of cancers, and potential endocrine-based therapeutic approaches to tackle these diseases.

  10. Nuclear receptors for retinoic acid and thyroid hormone regulate transcription of keratin genes.

    PubMed Central

    Tomic, M; Jiang, C K; Epstein, H S; Freedberg, I M; Samuels, H H; Blumenberg, M

    1990-01-01

    In the epidermis, retinoids regulate the expression of keratins, the intermediate filament proteins of epithelial cells. We have cloned the 5' regulatory regions of four human epidermal keratin genes, K#5, K#6, K#10, and K#14, and engineered constructs in which these regions drive the expression of the CAT reporter gene. By co-transfecting the constructs into epithelial cells along with the vectors expressing nuclear receptors for retinoic acid (RA) and thyroid hormone, we have demonstrated that the receptors can suppress the promoters of keratin genes. The suppression is ligand dependent; it is evident both in established cell lines and in primary cultures of epithelial cells. The three RA receptors have similar effects on keratin gene transcription. Our data indicate that the nuclear receptors for RA and thyroid hormone regulate keratin synthesis by binding to negative recognition elements in the upstream DNA sequences of the keratin genes. RA thus has a twofold effect on epidermal keratin expression: qualitatively, it regulates the regulators that effect the switch from basal cell-specific keratins to differentiation-specific ones; and quantitatively, it determines the level of keratin synthesis within the cell by direct interaction of its receptors with the keratin gene promoters. Images PMID:1712634

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

    SciTech Connect

    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

    2010-01-12

    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 β-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.

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

    PubMed

    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. PMID:27089421

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

    PubMed Central

    2010-01-01

    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. PMID:20863373

  14. Gonadotropin-releasing hormone and its receptor in normal and malignant cells.

    PubMed

    Harrison, G S; Wierman, M E; Nett, T M; Glode, L M

    2004-12-01

    Gonadotropin-releasing hormone (GnRH) is the hypothalamic factor that mediates reproductive competence. Intermittent GnRH secretion from the hypothalamus acts upon its receptor in the anterior pituitary to regulate the production and release of the gonadotropins, LH and FSH. LH and FSH then stimulate sex steroid hormone synthesis and gametogenesis in the gonads to ensure reproductive competence. The pituitary requires pulsatile stimulation by GnRH to synthesize and release the gonadotropins LH and FSH. Clinically, native GnRH is used in a pump delivery system to create an episodic delivery pattern to restore hormonal defects in patients with hypogonadotropic hypogonadism. Agonists of GnRH are delivered in a continuous mode to turn off reproductive function by inhibiting gonadotropin production, thus lowering sex steroid production, resulting in medical castration. They have been used in endocrine disorders such as precocious puberty, endometriosis and leiomyomata, but are also studied extensively in hormone-dependent malignancies. The detection of GnRH and its receptor in other tissues, including the breast, ovary, endometrium, placenta and prostate suggested that GnRH agonists and antagonists may also have direct actions at peripheral targets. This paper reviews the current data concerning differential control of GnRH and GnRH receptor expression and signaling in the hypothalamic-pituitary axis and extrapituitary tissues. Using these data as a backdrop, we then review the literature about the action of GnRH in cancer cells, the utility of GnRH analogs in various malignancies and then update the research in novel therapies targeted to the GnRH receptor in cancer cells to promote anti-proliferative effects and control of tumor burden.

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

    PubMed

    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.

  16. Direct modulation of simian virus 40 late gene expression by thyroid hormone and its receptor.

    PubMed

    Zuo, F; Kraus, R J; Gulick, T; Moore, D D; Mertz, J E

    1997-01-01

    Transcription of the late genes of simian virus 40 (SV40) is repressed during the early phase of the lytic cycle of infection of primate cells by the binding of cellular factors, called IBP-s, to the SV40 late promoter; repression is relieved after the onset of viral DNA replication by titration of these repressors (S. R. Wiley, R. J. Kraus, F. R. Zuo, E. E. Murray, K. Loritz, and J. E. Mertz, Genes Dev. 7:2206-2219, 1993). Recently, we showed that IBP-s consists of several members of the steroid/thyroid hormone receptor superfamily (F. Zuo and J. E. Mertz, Proc. Natl. Acad. Sci. USA 92:8586-8590, 1995). Here, we show that the thyroid hormone receptor TRalpha1, in combination with retinoid X receptor alpha (RXRalpha), is specifically bound at the transcriptional initiation site of the major late promoter of SV40. This binding repressed transcription from the SV40 late promoter by preventing the formation of pre-initiation complexes. Addition of the thyroid hormone 3,5,3'-L-triiodothyronine (T3) resulted in reversal of this repression in cotransfected CV-1 cells. Interestingly, repression did not occur when this thyroid response element (TRE) was translocated to 50 bp upstream of the major late initiation site. Binding of TRalpha1/RXRalpha heterodimers to this TRE induced bending of the promoter DNA. We conclude that hormones and their receptors can directly affect the expression of SV40, probably by affecting protein-protein and protein-DNA interactions involved in the formation of functional preinitiation complexes.

  17. DWARF14 is a non-canonical hormone receptor for strigolactone.

    PubMed

    Yao, Ruifeng; Ming, Zhenhua; Yan, Liming; Li, Suhua; Wang, Fei; Ma, Sui; Yu, Caiting; Yang, Mai; Chen, Li; Chen, Linhai; Li, Yuwen; Yan, Chun; Miao, Di; Sun, Zhongyuan; Yan, Jianbin; Sun, Yuna; Wang, Lei; Chu, Jinfang; Fan, Shilong; He, Wei; Deng, Haiteng; Nan, Fajun; Li, Jiayang; Rao, Zihe; Lou, Zhiyong; Xie, Daoxin

    2016-08-25

    Classical hormone receptors reversibly and non-covalently bind active hormone molecules, which are generated by biosynthetic enzymes, to trigger signal transduction. The α/β hydrolase DWARF14 (D14), which hydrolyses the plant branching hormone strigolactone and interacts with the F-box protein D3/MAX2, is probably involved in strigolactone detection. However, the active form of strigolactone has yet to be identified and it is unclear which protein directly binds the active form of strigolactone, and in which manner, to act as the genuine strigolactone receptor. Here we report the crystal structure of the strigolactone-induced AtD14-D3-ASK1 complex, reveal that Arabidopsis thaliana (At)D14 undergoes an open-to-closed state transition to trigger strigolactone signalling, and demonstrate that strigolactone is hydrolysed into a covalently linked intermediate molecule (CLIM) to initiate a conformational change of AtD14 to facilitate interaction with D3. Notably, analyses of a highly branched Arabidopsis mutant d14-5 show that the AtD14(G158E) mutant maintains enzyme activity to hydrolyse strigolactone, but fails to efficiently interact with D3/MAX2 and loses the ability to act as a receptor that triggers strigolactone signalling in planta. These findings uncover a mechanism underlying the allosteric activation of AtD14 by strigolactone hydrolysis into CLIM, and define AtD14 as a non-canonical hormone receptor with dual functions to generate and sense the active form of strigolactone. PMID:27479325

  18. Identification of SRC3/AIB1 as a Preferred Coactivator for Hormone-activated Androgen Receptor

    SciTech Connect

    Zhou, X. Edward; Suino-Powell, Kelly M.; Li, Jun; He, Yuanzheng; MacKeigan, Jeffrey P.; Melcher, Karsten; Yong, Eu-Leong; Xu, H.Eric

    2010-09-17

    Transcription activation by androgen receptor (AR), which depends on recruitment of coactivators, is required for the initiation and progression of prostate cancer, yet the mechanisms of how hormone-activated AR interacts with coactivators remain unclear. This is because AR, unlike any other nuclear receptor, prefers its own N-terminal FXXLF motif to the canonical LXXLL motifs of coactivators. Through biochemical and crystallographic studies, we identify that steroid receptor coactivator-3 (SRC3) (also named as amplified in breast cancer-1 or AIB1) interacts strongly with AR via synergistic binding of its first and third LXXLL motifs. Mutagenesis and functional studies confirm that SRC3 is a preferred coactivator for hormone-activated AR. Importantly, AR mutations found in prostate cancer patients correlate with their binding potency to SRC3, corroborating with the emerging role of SRC3 as a prostate cancer oncogene. These results provide a molecular mechanism for the selective utilization of SRC3 by hormone-activated AR, and they link the functional relationship between AR and SRC3 to the development and growth of prostate cancer.

  19. The Thyroid Hormone Receptors Inhibit Hepatic Interleukin-6 Signaling During Endotoxemia.

    PubMed

    Contreras-Jurado, Constanza; Alonso-Merino, Elvira; Saiz-Ladera, Cristina; Valiño, Arturo José; Regadera, Javier; Alemany, Susana; Aranda, Ana

    2016-08-03

    Decreased thyroidal hormone production is found during lipopolysaccharide (LPS)-induced endotoxic shock in animals as well as in critically ill patients. Here we studied the role of the thyroid hormone receptors (TRs) in activation of STAT3, NF-κB and ERK, which play a key role in the response to inflammatory cytokines during sepsis. TR knockout mice showed down-regulation of hepatic inflammatory mediators, including interleukin 6 (IL-6) in response to LPS. Paradoxically, STAT3 and ERK activity were higher, suggesting that TRs could act as endogenous repressors of these pathways. Furthermore, hyperthyroidism increased cytokine production and mortality in response to LPS, despite decreasing hepatic STAT3 and ERK activity. This suggested that TRs could directly repress the response of the cells to inflammatory mediators. Indeed, we found that the thyroid hormone T3 suppresses IL-6 signalling in macrophages and hepatocarcinoma cells, inhibiting STAT3 activation. Consequently, the hormone strongly antagonizes IL-6-stimulated gene transcription, reducing STAT3 recruitment and histone acetylation at IL-6 target promoters. In conclusion, TRs are potent regulators of inflammatory responses and immune homeostasis during sepsis. Reduced responses to IL-6 should serve as a negative feedback mechanism for preventing deleterious effects of excessive hormone signaling during infections.

  20. The Thyroid Hormone Receptors Inhibit Hepatic Interleukin-6 Signaling During Endotoxemia

    PubMed Central

    Contreras-Jurado, Constanza; Alonso-Merino, Elvira; Saiz-Ladera, Cristina; Valiño, Arturo José; Regadera, Javier; Alemany, Susana; Aranda, Ana

    2016-01-01

    Decreased thyroidal hormone production is found during lipopolysaccharide (LPS)-induced endotoxic shock in animals as well as in critically ill patients. Here we studied the role of the thyroid hormone receptors (TRs) in activation of STAT3, NF-κB and ERK, which play a key role in the response to inflammatory cytokines during sepsis. TR knockout mice showed down-regulation of hepatic inflammatory mediators, including interleukin 6 (IL-6) in response to LPS. Paradoxically, STAT3 and ERK activity were higher, suggesting that TRs could act as endogenous repressors of these pathways. Furthermore, hyperthyroidism increased cytokine production and mortality in response to LPS, despite decreasing hepatic STAT3 and ERK activity. This suggested that TRs could directly repress the response of the cells to inflammatory mediators. Indeed, we found that the thyroid hormone T3 suppresses IL-6 signalling in macrophages and hepatocarcinoma cells, inhibiting STAT3 activation. Consequently, the hormone strongly antagonizes IL-6-stimulated gene transcription, reducing STAT3 recruitment and histone acetylation at IL-6 target promoters. In conclusion, TRs are potent regulators of inflammatory responses and immune homeostasis during sepsis. Reduced responses to IL-6 should serve as a negative feedback mechanism for preventing deleterious effects of excessive hormone signaling during infections. PMID:27484112

  1. The Thyroid Hormone Receptors Inhibit Hepatic Interleukin-6 Signaling During Endotoxemia.

    PubMed

    Contreras-Jurado, Constanza; Alonso-Merino, Elvira; Saiz-Ladera, Cristina; Valiño, Arturo José; Regadera, Javier; Alemany, Susana; Aranda, Ana

    2016-01-01

    Decreased thyroidal hormone production is found during lipopolysaccharide (LPS)-induced endotoxic shock in animals as well as in critically ill patients. Here we studied the role of the thyroid hormone receptors (TRs) in activation of STAT3, NF-κB and ERK, which play a key role in the response to inflammatory cytokines during sepsis. TR knockout mice showed down-regulation of hepatic inflammatory mediators, including interleukin 6 (IL-6) in response to LPS. Paradoxically, STAT3 and ERK activity were higher, suggesting that TRs could act as endogenous repressors of these pathways. Furthermore, hyperthyroidism increased cytokine production and mortality in response to LPS, despite decreasing hepatic STAT3 and ERK activity. This suggested that TRs could directly repress the response of the cells to inflammatory mediators. Indeed, we found that the thyroid hormone T3 suppresses IL-6 signalling in macrophages and hepatocarcinoma cells, inhibiting STAT3 activation. Consequently, the hormone strongly antagonizes IL-6-stimulated gene transcription, reducing STAT3 recruitment and histone acetylation at IL-6 target promoters. In conclusion, TRs are potent regulators of inflammatory responses and immune homeostasis during sepsis. Reduced responses to IL-6 should serve as a negative feedback mechanism for preventing deleterious effects of excessive hormone signaling during infections. PMID:27484112

  2. Luteinizing hormone/human chorionic gonadotrophin receptors in various epidermal structures.

    PubMed

    Venencie, P Y; Méduri, G; Pissard, S; Jolivet, A; Loosfelt, H; Milgrom, E; Misrahi, M

    1999-09-01

    Two different monoclonal antibodies recognizing different epitopes were used to study the localization of luteinizing hormone/human chorionic gonadotrophin (LH/hCG) receptors in human skin. Immunolabelling was observed only in the epidermis and derived structures but not in the dermis. The basal, spinal and granular layers were stained, whereas no receptors were detected in the non-nucleated horny cells. In the growing (anagen) hair, immunostaining was found in the inner root sheath below the level of the sebaceous glands and in the outer root sheath above this level. In the resting (telogen) hair, only the latter staining was observed. In the sebaceous glands, only the thin cells close to the walls of the ducts were immunolabelled. In the eccrine sweat glands, the external clear cells were stained in the secretory portion of the gland, whereas only the cells close to the lumen were labelled in the ducts. The distribution of LH/hCG receptors was compared with that of steroidogenic enzymes (side chain cleavage cytochrome P450, adrenodoxin, 3-beta-hydroxy-5-ene steroid dehydrogenase Delta5-Delta4 isomerase, 17-hydroxylase cytochrome P450 and cytochrome P450 aromatase). Only partial overlaps were observed. The presence of LH receptor mRNA in the skin was confirmed by reverse transcription-polymerase chain reaction. Monoclonal antibodies raised against the human follicle-stimulating hormone receptor failed to detect the latter in the epidermal structures and in the dermis. The role of LH and hCG in skin modifications occurring during pregnancy and after the menopause is unknown. These hormones may possibly act by regulating steroidogenic enzymes or by modulating cell growth and differentiation. PMID:10583046

  3. Immunocytochemical localization of thyroid hormone nuclear receptors in cultured acetylcholinesterase-positive neurons: a correlation between the presence of thyroid hormone nuclear receptors and L-tri-iodothyronine morphological effects.

    PubMed

    Garza, R; Puymirat, J; Dussault, J H

    1990-01-01

    A monoclonal antibody against the rat liver L-tri-iodothyronine nuclear receptor and acetylcholinesterase cytochemistry were used for the localization of thyroid hormone nuclear receptors in acetylcholinesterase-positive cell nuclei in fetal rat cerebral hemisphere neuronal cultures. After 3 days in vitro, the ratio of acetylcholinesterase-positive cells that were immunoreactive for the thyroid hormone nuclear receptor to those not stained for this receptor (74-26%, respectively) remains unchanged despite an increase in the number of acetylcholinesterase-positive cells with time (from day 3 to day 21) in culture. Furthermore, the addition of 3 X 10(-8) L-tri-iodothyronine in culture did not modify this ratio or have an effect on the number of acetylcholinesterase-positive cells, but significantly increased the neurite density in those acetylcholinesterase-positive cells that were immunoreactive for the thyroid hormone receptor. Conversely, no difference in the neurite densities of those acetylcholinesterase-positive cells not stained for this receptor was observed when cultured in the presence or absence of thyroid hormone. In other experiments with the same fetal brain cultures, treatment of cultures for 8 days with L-tri-iodothyronine, beginning on culture day 20, demonstrated the presence of a critical period which occurs in vitro around day 20, since the stimulatory effect of L-tri-iodothyronine on immunoreactive acetylcholinesterase-positive cell neurite density is lost after 20 days in vitro. These results demonstrate, for the first time, the presence of L-tri-iodothyronine nuclear receptors in fetal rat acetylcholinesterase-positive neurons and the existence of a cellular heterogeneity in the distribution of the thyroid hormone receptor. The presence of these receptors in fetal brain acetylcholinesterase-positive neurons suggests that some effects of L-tri-iodothyronine on the maturation of a subpopulation of acetylcholinesterase-positive neurons may result

  4. Hormone Activity of Hydroxylated Polybrominated Diphenyl Ethers on Human Thyroid Receptor-β: In Vitro and In Silico Investigations

    PubMed Central

    Li, Fei; Xie, Qing; Li, Xuehua; Li, Na; Chi, Ping; Chen, Jingwen; Wang, Zijian; Hao, Ce

    2010-01-01

    Background Hydroxylated polybrominated diphenyl ethers (HO-PBDEs) may disrupt thyroid hormone status because of their structural similarity to thyroid hormone. However, the molecular mechanisms of interactions with thyroid hormone receptors (TRs) are not fully understood. Objectives We investigated the interactions between HO-PBDEs and TRβ to identify critical structural features and physicochemical properties of HO-PBDEs related to their hormone activity, and to develop quantitative structure–activity relationship (QSAR) models for the thyroid hormone activity of HO-PBDEs. Methods We used the recombinant two-hybrid yeast assay to determine the hormone activities to TRβ and molecular docking to model the ligand–receptor interaction in the binding site. Based on the mechanism of action, molecular structural descriptors were computed, selected, and employed to characterize the interactions, and finally a QSAR model was constructed. The applicability domain (AD) of the model was assessed by Williams plot. Results The 18 HO-PBDEs tested exhibited significantly higher thyroid hormone activities than did PBDEs (p < 0.05). Hydrogen bonding was the characteristic interaction between HO-PBDE molecules and TRβ, and aromaticity had a negative effect on the thyroid hormone activity of HO-PBDEs. The developed QSAR model had good robustness, predictive ability, and mechanism interpretability. Conclusions Hydrogen bonding and electrostatic interactions between HO-PBDEs and TRβ are important factors governing thyroid hormone activities. The HO-PBDEs with higher ability to accept electrons tend to have weak hydrogen bonding with TRβ and lower thyroid hormone activities. PMID:20439171

  5. Are Estrogen Receptor Genomic Aberrations Predictive of Hormone Therapy Response in Breast Cancer?

    PubMed Central

    Tabarestani, Sanaz; Motallebi, Marzieh; Akbari, Mohammad Esmaeil

    2016-01-01

    Context Breast cancer is the most common cancer in women worldwide. Estrogen receptor (ER) positive breast cancer constitutes the majority of these cancers. Hormone therapy has significantly improved clinical outcomes for early- and late-stage hormone receptor positive breast cancer. Although most patients with early stage breast cancer are treated with curative intent, approximately 20% - 30% of patients eventually experience a recurrence. During the last two decades, there have been tremendous efforts to understand the biological mechanisms of hormone therapy resistance, with the ultimate goal of implementing new therapeutic strategies to improve the current treatments for ER positive breast cancer. Several mechanisms of hormone therapy resistance have been proposed, including genetic alterations that lead to altered ER expression or ERs with changed protein sequence. Evidence Acquisition A Pubmed search was performed utilizing various related terms. Articles over the past 20 years were analyzed and selected for review. Results On the basis of published studies, the frequencies of ESR1 (the gene encoding ER) mutations in ER positive metastatic breast cancer range from 11% to 55%. Future larger prospective studies with standardized mutation detection methods may be necessary to determine the true incidence of ESR1 mutations. ESR1 amplification in breast cancer remains a controversial issue, with numerous studies either confirmed or challenged the reports of ESR1 amplification. The combination of intra-tumor heterogeneity regarding ESR1 copy number alterations and low level ESR1 copy number increase may account for these discrepancies. Conclusions While numerous unknown issues on the role of ESR1 mutations in advanced breast cancer remain, these new findings will certainly deepen current knowledge on molecular evolution of breast cancer and acquired resistance to hormone therapy.

  6. Evidence for Follicle-stimulating Hormone Receptor as a Functional Trimer*

    PubMed Central

    Jiang, Xuliang; Fischer, David; Chen, Xiaoyan; McKenna, Sean D.; Liu, Heli; Sriraman, Venkataraman; Yu, Henry N.; Goutopoulos, Andreas; Arkinstall, Steve; He, Xiaolin

    2014-01-01

    Follicle-stimulating hormone receptor (FSHR), a G-protein coupled receptor, is an important drug target in the development of novel therapeutics for reproductive indications. The FSHR extracellular domains were observed in the crystal structure as a trimer, which enabled us to propose a novel model for the receptor activation mechanism. The model predicts that FSHR binds Asnα52-deglycosylated FSH at a 3-fold higher capacity than fully glycosylated FSH. It also predicts that, upon dissociation of the FSHR trimer into monomers, the binding of glycosylated FSH, but not deglycosylated FSH, would increase 3-fold, and that the dissociated monomers would in turn enhance FSHR binding and signaling activities by 3-fold. This study presents evidence confirming these predictions and provides crystallographic and mutagenesis data supporting the proposed model. The model also provides a mechanistic explanation to the agonist and antagonist activities of thyroid-stimulating hormone receptor autoantibodies. We conclude that FSHR exists as a functional trimer. PMID:24692546

  7. Structure and chromosomal localization of the human antidiuretic hormone receptor gene

    SciTech Connect

    Seibold, A.; Brabet, P.; Rosenthal, W.; Birnbaumer, M. )

    1992-11-01

    Applying a genomic DNA-expression approach, the authors cloned the gene and cDNA coding for the human antidiuretic hormone receptor, also called vasopressin V2 receptor' (V2R). The nucleotide sequence of both cloned DNAs provided the information to elucidate the structure of the isolated transcriptional unit. The structure of this gene is unusual in that it is the first G protein-coupled receptor gene that contains two very small intervening sequences, the second of which separates the region encoding the seventh transmembrane region from the rest of the open reading frame. The sequence information was used to synthesize appropriate oligonucleotides to be used as primers in the PCR. The V2R gene was localized by PCR using DNA from hybrid cells as template. The gene was found to reside in the q28-qter portion of the human X chromosome, a region identified as the locus for congential nephrogenic diabetes insipidus. 27 refs., 4 figs.

  8. A missense mutation in the second transmembrane segment of the luteinizing hormone receptor causes familial male-limited precocious puberty

    SciTech Connect

    Kraaij, R.; Post, M.; Grootegoed, J.A.

    1995-10-01

    Patients with familial male-limited precocious puberty present with early onset of puberty. Several missense mutations in the LH receptor gene that cause amino acid substitutions in the sixth transmembrane segment of the receptor protein have been shown to be a cause of the disorder. We have identified a novel LH receptor gene mutation in a patient with familial male-limited precocious puberty that results in a threonine for methionine substitution at position 398 in the second transmembrane segment of the receptor protein. In vitro expression in human embryonic kidney 293 cells of this LH receptor mutant and two previously described LH receptor mutants showed that cAMP production in the absence of hormone was elevated up to 25-fold compared to the basal level of the wild-type receptor. The ED{sub 50} values of hormone-induced cAMP production was relatively low for mutant receptors. We also produced receptors containing amino acid substitutions in both the second and sixth transmembrane segments. For these double mutants, basal receptor activities were similar to the basal activities observed in single mutants, whereas hormone-induced receptor activation was almost completely abolished. 31 refs., 2 figs.

  9. Steroid hormone receptor in pleural solitary fibrous tumours and CD34+ progenitor stromal cells.

    PubMed

    Bongiovanni, Massimo; Viberti, Laura; Pecchioni, Carla; Papotti, Mauro; Thonhofer, Renè; Hans Popper, Helmut; Sapino, Anna

    2002-10-01

    Solitary fibrous tumours (SFT), originally described in the pleura, were subsequently recognized in numerous extrapleural sites. This suggests that a common stem cell, present in various organs and tissues, may be at the origin of SFT and that specific factors may be involved in the proliferation of such cells. Recently it has been described that steroid hormone receptors, progesterone receptors in particular, are expressed by extrapleural SFT. In addition, progesterone may participate as growth factor in many CD34(+) stromal neoplasms, which express low levels of the hormone receptors. The present study analysed the expression of androgen (AR), oestrogen (ER) and progesterone (PR) receptors in a series of 32 pleural SFT, 10 mesotheliomas and in reactive tissue of chronic pleuritis. ER and AR were never expressed by SFT or by chronic pleuritis, whereas PR were demonstrated in 2/16 "large" (>8 cm) and in 6/16 "small" (< or =8 cm) pleural SFT (all expressing CD34, bcl-2 and CD99). PR(+) SFT had a significantly higher proliferative activity (p = 0.04) (Ki-67 mean value 6.5%) and lower p27(kip1) (mean value 51.5%) expression than the PR(-) cases (Ki-67 mean value 3.81% and p27(kip1) mean value 57.86%). One of the cases expressing a high level of PR (80%) recurred 1 year after first surgery and the recurrence was PR(+) as well, but with a lower percentage of nuclear receptor expression (12%). In addition, in chronically inflamed subserosal tissue, a subpopulation of CD34(+) endothelial and interstitial dendritic cells was identified, which also expressed PR. These findings suggest that the CD34(+) submesothelial interstitial dendritic cells, activated during reactive processes, may be the stem cells that give rise to SFT, and that progesterone might participate in the growth of SFT through modulation of its specific receptors.

  10. Defective membrane expression of human growth hormone (GH) receptor causes Laron-type GH insensitivity syndrome.

    PubMed Central

    Duquesnoy, P; Sobrier, M L; Amselem, S; Goossens, M

    1991-01-01

    Mutations in the growth hormone receptor (GHR) gene can cause growth hormone (GH) resistance. Given the sequence homology between the extracellular domain of the GHR and a soluble GH-binding protein (GH-BP), it is remarkable that GH-BP binding activity is absent from the serum of patients with Laron-type GH insensitivity, a hereditary form of severe dwarfism. We have previously identified a mutation within the extracellular domain of this receptor, replacing phenylalanine by serine at position 96 of the mature protein, in a patient with Laron syndrome. We have now investigated the effect of this Phe----Ser substitution on hormone binding activity by expressing the total human GHR cDNA and mutant form in eukaryotic cells. The wild-type protein expressed was able to bind GH but no plasma membrane binding was detectable on cells transfected with the mutant cDNA; this was also the case of cells transfected with a Phe96----Ala mutant cDNA, suggesting that the lack of binding activity is not due to a posttranslational modification of serine. Examination of the variant proteins in subcellular fractions revealed the presence of specific GH binding activity in the lysosomal fraction, whereas immunofluorescence studies located mutant proteins in the cytosol. Our findings suggest that these mutant GHRs fail to follow the correct intracellular transport pathway and underline the potential importance of this phenylalanine residue, which is conserved among the GH, prolactin, and erythropoietin receptors that belong to the same cytokine receptor superfamily. Images PMID:1719554

  11. Sex hormone receptors in the hypothalamus and their role in sexual differentiation of the male rat brain

    SciTech Connect

    Shishkina, I.V.; Babichev, V.N.; Ozol', L.Yu.

    1986-09-01

    In this investigation, changes in the level of receptors for sex hormones in the hypothalamus and cerebral cortex of male rats were studied on the first through fifth days of postnatal life, and the results obtained were compared with the levels of luteinizing hormone and sex hormones in the peripheral blood in order to discover any correlation between these parameters. 2,4,6,7,-/sup 3/H-estradiol-17..beta.. and 1,2,6,7-/sup 3/H-testosterone were used as labeled hormones. The values of the association constant and concentration of specific binding sites for estradiol and testosterone in hypothalamus and cerebral cortex of male rats during neonatal development is shown. It is found that in male rats on the first day after birth, receptors for estradiol and testosterone are present and they enable the action both of the testicular hormone and that of estradiol to be realized.

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

    SciTech Connect

    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 (/sup 3/H)-3-methyl-histidine/sup 2/-TRH ((/sup 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.

  13. Identification of Thyroid Hormones and Functional Characterization of Thyroid Hormone Receptor in the Pacific Oyster Crassostrea gigas Provide Insight into Evolution of the Thyroid Hormone System.

    PubMed

    Huang, Wen; Xu, Fei; Qu, Tao; Zhang, Rui; Li, Li; Que, Huayong; Zhang, Guofan

    2015-01-01

    Thyroid hormones (THs) play important roles in development, metamorphosis, and metabolism in vertebrates. During the past century, TH functions were regarded as a synapomorphy of vertebrates. More recently, accumulating evidence has gradually convinced us that TH functions also occur in invertebrate chordates. To date, however, TH-related studies in non-chordate invertebrates have been limited. In this study, THs were qualitatively detected by two reliable methods (HPLC and LC/MS) in a well-studied molluscan species, the Pacific oyster Crassostrea gigas. Quantitative measurement of THs during the development of C. gigas showed high TH contents during embryogenesis and that oyster embryos may synthesize THs endogenously. As a first step in elucidating the TH signaling cascade, an ortholog of vertebrate TH receptor (TR), the most critical gene mediating TH effects, was cloned in C. gigas. The sequence of CgTR has conserved DNA-binding and ligand-binding domains that normally characterize these receptors. Experimental results demonstrated that CgTR can repress gene expression through binding to promoters of target genes and can interact with oyster retinoid X receptor. Moreover, CgTR mRNA expression was activated by T4 and the transcriptional activity of CgTR promoter was repressed by unliganded CgTR protein. An atypical thyroid hormone response element (CgDR5) was found in the promoter of CgTR, which was verified by electrophoretic mobility shift assay (EMSA). These results indicated that some of the CgTR function is conserved. However, the EMSA assay showed that DNA binding specificity of CgTR was different from that of the vertebrate TR and experiments with two dual-luciferase reporter systems indicated that l-thyroxine, 3,3',5-triiodothyronine, and triiodothyroacetic acid failed to activate the transcriptional activity of CgTR. This is the first study to functionally characterize TR in mollusks. The presence of THs and the functions of CgTR in mollusks contribute

  14. Identification of Thyroid Hormones and Functional Characterization of Thyroid Hormone Receptor in the Pacific Oyster Crassostrea gigas Provide Insight into Evolution of the Thyroid Hormone System.

    PubMed

    Huang, Wen; Xu, Fei; Qu, Tao; Zhang, Rui; Li, Li; Que, Huayong; Zhang, Guofan

    2015-01-01

    Thyroid hormones (THs) play important roles in development, metamorphosis, and metabolism in vertebrates. During the past century, TH functions were regarded as a synapomorphy of vertebrates. More recently, accumulating evidence has gradually convinced us that TH functions also occur in invertebrate chordates. To date, however, TH-related studies in non-chordate invertebrates have been limited. In this study, THs were qualitatively detected by two reliable methods (HPLC and LC/MS) in a well-studied molluscan species, the Pacific oyster Crassostrea gigas. Quantitative measurement of THs during the development of C. gigas showed high TH contents during embryogenesis and that oyster embryos may synthesize THs endogenously. As a first step in elucidating the TH signaling cascade, an ortholog of vertebrate TH receptor (TR), the most critical gene mediating TH effects, was cloned in C. gigas. The sequence of CgTR has conserved DNA-binding and ligand-binding domains that normally characterize these receptors. Experimental results demonstrated that CgTR can repress gene expression through binding to promoters of target genes and can interact with oyster retinoid X receptor. Moreover, CgTR mRNA expression was activated by T4 and the transcriptional activity of CgTR promoter was repressed by unliganded CgTR protein. An atypical thyroid hormone response element (CgDR5) was found in the promoter of CgTR, which was verified by electrophoretic mobility shift assay (EMSA). These results indicated that some of the CgTR function is conserved. However, the EMSA assay showed that DNA binding specificity of CgTR was different from that of the vertebrate TR and experiments with two dual-luciferase reporter systems indicated that l-thyroxine, 3,3',5-triiodothyronine, and triiodothyroacetic acid failed to activate the transcriptional activity of CgTR. This is the first study to functionally characterize TR in mollusks. The presence of THs and the functions of CgTR in mollusks contribute

  15. Identification of Thyroid Hormones and Functional Characterization of Thyroid Hormone Receptor in the Pacific Oyster Crassostrea gigas Provide Insight into Evolution of the Thyroid Hormone System

    PubMed Central

    Huang, Wen; Xu, Fei; Qu, Tao; Zhang, Rui; Li, Li; Que, Huayong; Zhang, Guofan

    2015-01-01

    Thyroid hormones (THs) play important roles in development, metamorphosis, and metabolism in vertebrates. During the past century, TH functions were regarded as a synapomorphy of vertebrates. More recently, accumulating evidence has gradually convinced us that TH functions also occur in invertebrate chordates. To date, however, TH-related studies in non-chordate invertebrates have been limited. In this study, THs were qualitatively detected by two reliable methods (HPLC and LC/MS) in a well-studied molluscan species, the Pacific oyster Crassostrea gigas. Quantitative measurement of THs during the development of C. gigas showed high TH contents during embryogenesis and that oyster embryos may synthesize THs endogenously. As a first step in elucidating the TH signaling cascade, an ortholog of vertebrate TH receptor (TR), the most critical gene mediating TH effects, was cloned in C. gigas. The sequence of CgTR has conserved DNA-binding and ligand-binding domains that normally characterize these receptors. Experimental results demonstrated that CgTR can repress gene expression through binding to promoters of target genes and can interact with oyster retinoid X receptor. Moreover, CgTR mRNA expression was activated by T4 and the transcriptional activity of CgTR promoter was repressed by unliganded CgTR protein. An atypical thyroid hormone response element (CgDR5) was found in the promoter of CgTR, which was verified by electrophoretic mobility shift assay (EMSA). These results indicated that some of the CgTR function is conserved. However, the EMSA assay showed that DNA binding specificity of CgTR was different from that of the vertebrate TR and experiments with two dual-luciferase reporter systems indicated that l-thyroxine, 3,3′,5-triiodothyronine, and triiodothyroacetic acid failed to activate the transcriptional activity of CgTR. This is the first study to functionally characterize TR in mollusks. The presence of THs and the functions of CgTR in mollusks

  16. Antagonist of GH-releasing hormone receptors alleviates experimental ocular inflammation.

    PubMed

    Qin, Yong Jie; Chan, Sun On; Chong, Kelvin Kam Lung; Li, Benjamin Fuk Loi; Ng, Tsz Kin; Yip, Yolanda Wong Ying; Chen, Haoyu; Zhang, Mingzhi; Block, Norman L; Cheung, Herman S; Schally, Andrew V; Pang, Chi Pui

    2014-12-23

    Disruptions in immunity and occurrence of inflammation cause many eye diseases. The growth hormone-releasing hormone-growth hormone-insulin-like growth factor-1 (GHRH-GH-IGF1) axis exerts regulatory effects on the immune system. Its involvement in ocular inflammation remains to be investigated. Here we studied this signaling in endotoxin-induced uveitis (EIU) generated by LPS. The increase in GHRH receptor (GHRH-R) protein levels was parallel to the increase in mRNA levels of pituitary-specific transcription factor-1, GHRH-R splice variant 1, GHRH, and GH following LPS insult. Elevation of GHRH-R and GH receptor was localized on the epithelium of the iris and ciliary body, and GHRH-R was confined to the infiltrating macrophages and leukocytes in aqueous humor but not to those in stroma. Treatment with GHRH-R antagonist decreased LPS-stimulated surges of GH and IGF1 in aqueous humor and alleviated inflammation by reducing the infiltration of macrophages and leukocytes and the production of TNF-α, IL-1β, and monocyte chemotactic protein-1. Our results indicate that inflammation in the iris and ciliary body involves the activation of GHRH signaling, which affects the recruitment of immune cells and the production of proinflammatory mediators that contribute to EIU pathogenesis. Moreover, the results suggest that GHRH-R antagonists are potential therapeutic agents for the treatment of acute ocular inflammation. PMID:25489106

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

    PubMed

    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.

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

    PubMed

    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. PMID:24769041

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

    PubMed

    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. PMID:26118876

  20. Thyroid hormone regulates vitellogenin by inducing estrogen receptor alpha in the goldfish liver.

    PubMed

    Nelson, Erik R; Habibi, Hamid R

    2016-11-15

    Vitellogenin (Vtg) is an egg-yolk precursor protein that is synthesized in the liver of oviparous species and taken up from the circulation by the ovary. It is well known that Vtg is induced by circulating estrogens. However, other endocrine factors that regulate the expression of Vtg are less well characterized; factors that might play significant roles, especially in seasonal spawners such as the goldfish which require increased quantities of Vtg for the development of hundreds of follicles. In this regard, thyroid hormones have been shown to cycle with the reproductive season. Therefore, we hypothesized that the thyroid hormones might influence the synthesis of Vtg. Treatment of female goldfish with triiodothyronine (T3) resulted in increased Vtg, an observation that was absent in males. Furthermore, T3 failed to induce Vtg in cultured hepatocytes of either sex. Interestingly however, T3 consistently up-regulated the expression of the estrogen receptor alpha (ERα). The T3 mediated upregulation of ERα requires the presence of both thyroid receptor (TR) α-1 and TRβ. When goldfish or cultured hepatocytes were treated with T3 followed by estradiol, there was a synergistic increase in Vtg, a response which is dependent on the presence of ERα. Therefore, by upregulating ERα, T3 serves to prime the liver to subsequent stimuli from estradiol. This cross-talk likely reveals an important physiologic mechanism by which thyroid hormones, whose circulating levels are high during early gonadal recrudescence, facilitate the production of large amounts of Vtg required for egg development. PMID:27585488

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

    PubMed

    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.

  2. The structure and regulation of expression of the mouse growth hormone receptor and binding protein

    SciTech Connect

    Talamantes, F.

    1994-12-31

    The mouse growth hormone receptor (mGHR) and the mouse growth hormone-binding protein (mGHBP) are products of a single gene which are generated alternative splicing. The factors that regulate the expression of mGHR and mGHBP mRNA and protein during pregnancy in the mouse are incompletely understood. During pregnancy in the mouse, there are parallel increases in circulating mouse growth hormone (mGH), liver mGHR, and serum mGHBP. The increase in both hepatic mGHR and serum mGHBP begins on Day 9 of gestation and by late gestation the hepatic mGHR content has increased 8-fold and serum mGHBP has increased 30-fold compared with values in nonpregnant controls. A parallel increase occurs in the steady state levels of liver GHR and GHBP encoding mRNAs. The increase in both messages begins on Day 9 of gestation; however, the GHR mRNA reaches maximum levels by Day 13, while the GHBP mRNA continues to increase until the end of pregnancy. The magnitude of the increase in the GHR-encoding message is 15- to 20-fold between nonpregnant and late pregnant mice, and the magnitude of the increase in the GHBP-encoding message is 30- to 50-fold. Both pituitary mGH and the number of conceptuses influence the receptors and binding protein for mGH during pregnancy. 22 refs.

  3. Effects of growth hormone and feeding level on endocrine measurements, hormone receptors, muscle growth and performance of prepubertal heifers.

    PubMed

    Vestergaard, M; Purup, S; Frystyk, J; Løvendahl, P; Sørensen, M T; Riis, P M; Flint, D J; Sejrsen, K

    2003-09-01

    Prepubertal Friesian heifer calves (n = 24, initial BW = 195 +/- 5 kg) were assigned to a 2 x 2 factorial block design and used to evaluate the effects of daily GH treatment (0 or 15 mg/d) at either a low or a high feeding level in a 5-wk treatment period on endocrine measurements, hormone receptors, muscle growth, and overall performance. In the pretreatment period, a low feeding level was employed for all calves. During the treatment period, animals at the low feeding level had free access to a roughage-based mixture, whereas animals at the high feeding level had free access to a concentrate mixture and were offered 2 kg/d of the roughage-based mixture. Blood samples were collected weekly starting 3 wk before treatment. Longissimus (LM) and supraspinatus (SS) muscles were obtained at slaughter. Metabolizable energy intake was 81% higher, digestible CP intake was 140% higher, and ADG was 115% higher (all P < 0.001) at the high vs. low feeding level. Feed (DMI, ME, and protein) intake was not affected by GH treatment, but ADG was 18% higher (P < 0.13) in GH-treated than in control heifers at both feeding levels. Although of different magnitudes, the muscle anabolic effects of GH treatment and high vs. low feeding level were additive, and both treatments increased carcass weights (P < 0.02 and P < 0.001, respectively), LM (P < 0.05 and P < 0.001), and SS (P < 0.06 and P < 0.003). The anabolic effect of GH treatment was similar in both muscles, whereas the effect of feeding level was most pronounced in LM. Overall, GH treatment increased plasma GH, IGF-I (both P < 0.001), and IGFBP-3 (P < 0.02); however, GH treatment increased total IGF-I, free IGF-I, and IGFBP-3, and decreased IGFBP-2 mainly at the high feeding level (GH x feeding level interaction; P < 0.02, 0.01, 0.03, and 0.10, respectively). The high feeding level increased insulin, free and total IGF-I, and IGFBP-3 (all P < 0.001), but decreased GH and IGFBP-2 (both P < 0.001). High feeding increased type-1 IGF

  4. The Thyroid Hormone Receptor Is a Suppressor of ras-Mediated Transcription, Proliferation, and Transformation

    PubMed Central

    García-Silva, Susana; Aranda, Ana

    2004-01-01

    The thyroid hormone triiodothyronine (T3) has a profound effect on growth, differentiation, and metabolism in higher organisms. Here we demonstrate that T3 inhibits ras-induced proliferation in neuroblastoma cells and blocks induction of cyclin D1 expression by the oncogene. The hormone, at physiological concentrations, strongly antagonizes the transcriptional response mediated by the Ras/mitogen-activated protein kinase/ribosomal-S6 subunit kinase (Rsk) signaling pathway in cells expressing thyroid hormone receptors (TRs). T3 blocks the response to the oncogenic forms of the three ras isoforms (H-, K-, and N-ras) and both TRα and TRβ can mediate this action. The main target for induction of cyclin D1 transcription by oncogenic ras in neuroblastoma cells is a cyclic AMP response element (CRE) located in proximal promoter sequences, and T3 represses the transcriptional activity of b-Zip transcription factors such as CREB (CRE-binding protein) or ATF-2 (activation transcription factor 2) that are direct targets of Rsk2 and bind to this sequence. The hormone also blocks fibroblast transformation by oncogenic ras when TR is expressed. Furthermore, TRs act as suppressors of tumor formation by the oncogene in vivo in nude mice. The TRβ isoform has stronger antitransforming properties than the α isoform and can inhibit tumorigenesis even in hypothyroid mice. These results show the existence of a previously unrecognized transcriptional cross talk between the TRs and the ras oncogene which influences relevant processes such as cell proliferation, transformation, or tumorigenesis. PMID:15314161

  5. [Association of estrogens and selective estrogens receptors modulators: towards a renewal of the hormonal treatment?].

    PubMed

    Valéra, Marie-Cécile; Chantalat, Elodie; Vinel, Alexia; Benoit, Thibaut; Guillaume, Maeva; Game, Xavier; Gourdy, Pierre; Trémollières, Florence; Payrastre, Bernard; Arnal, Jean-François

    2015-01-01

    The life expectancy of women has risen in the past century from 48years to more than 80. The decline of endogenous estrogen production (in particular, the principal circulating physiological hormone, 17β-estradiol) at menopause (which occurs at an average of 51years) is often accompanied by a series of functional disorders that affect quality of life (QoL). This estrogen deficiency affects different tissues and results in an increase in the prevalence of various disorders, including but not limited to osteoporosis and cardiovascular disease. Hormone therapy for menopause is a relatively recent biomedical challenge, which underwent a downturn after the Women Health Initiative study of older postmenopausal women. We will summarize the WHI findings in the first part of this article. At Inserm unit 1048, we are working on understanding the protective effects of estrogen against the development of atherosclerosis and type 2 diabetes in murine models. We have also focused in recent years on modeling the impact of estrogen in thrombosis models, to attempt to clarify the complex relation between estrogen and thrombotic risk. In part II of this article, we will describe a new strategy of hormone therapy for menopause, combining estrogens and selective estrogen receptor modulators (SERM). We review the scientific underpinnings of this strategy, which may enable the renewal of hormone therapy for menopause.

  6. G-protein-coupled receptor kinase 2 terminates G-protein-coupled receptor function in steroid hormone 20-hydroxyecdysone signaling.

    PubMed

    Zhao, Wen-Li; Wang, Di; Liu, Chun-Yan; Zhao, Xiao-Fan

    2016-01-01

    G-protein-coupled receptors (GPCRs) transmit extracellular signals across the cell membrane. GPCR kinases (GRKs) desensitize GPCR signals in the cell membrane. However, the role and mechanism of GRKs in the desensitization of steroid hormone signaling are unclear. In this study, we propose that GRK2 is phosphorylated by protein kinase C (PKC) in response to induction by the steroid hormone 20-hydroxyecdysone (20E), which determines its translocation to the cell membrane of the lepidopteran Helicoverpa armigera. GRK2 protein expression is increased during the metamorphic stage because of induction by 20E. Knockdown of GRK2 in larvae causes accelerated pupation, an increase in 20E-response gene expression, and advanced apoptosis and metamorphosis. 20E induces translocation of GRK2 from the cytoplasm to the cell membrane via steroid hormone ecdysone-responsive GPCR (ErGPCR-2). GRK2 is phosphorylated by PKC on serine 680 after induction by 20E, which leads to the translocation of GRK2 to the cell membrane. GRK2 interacts with ErGPCR-2. These data indicate that GRK2 terminates the ErGPCR-2 function in 20E signaling in the cell membrane by a negative feedback mechanism. PMID:27412951

  7. G-protein-coupled receptor kinase 2 terminates G-protein-coupled receptor function in steroid hormone 20-hydroxyecdysone signaling

    PubMed Central

    Zhao, Wen-Li; Wang, Di; Liu, Chun-Yan; Zhao, Xiao-Fan

    2016-01-01

    G-protein-coupled receptors (GPCRs) transmit extracellular signals across the cell membrane. GPCR kinases (GRKs) desensitize GPCR signals in the cell membrane. However, the role and mechanism of GRKs in the desensitization of steroid hormone signaling are unclear. In this study, we propose that GRK2 is phosphorylated by protein kinase C (PKC) in response to induction by the steroid hormone 20-hydroxyecdysone (20E), which determines its translocation to the cell membrane of the lepidopteran Helicoverpa armigera. GRK2 protein expression is increased during the metamorphic stage because of induction by 20E. Knockdown of GRK2 in larvae causes accelerated pupation, an increase in 20E-response gene expression, and advanced apoptosis and metamorphosis. 20E induces translocation of GRK2 from the cytoplasm to the cell membrane via steroid hormone ecdysone-responsive GPCR (ErGPCR-2). GRK2 is phosphorylated by PKC on serine 680 after induction by 20E, which leads to the translocation of GRK2 to the cell membrane. GRK2 interacts with ErGPCR-2. These data indicate that GRK2 terminates the ErGPCR-2 function in 20E signaling in the cell membrane by a negative feedback mechanism. PMID:27412951

  8. Prognostic Value of Tumor-Associated Macrophages According to Histologic Locations and Hormone Receptor Status in Breast Cancer

    PubMed Central

    Gwak, Jae Moon; Jang, Min Hye; Kim, Dong Il; Seo, An Na; Park, So Yeon

    2015-01-01

    Tumor-associated macrophages (TAMs) are involved in tumor progression by promoting epithelial-mesenchymal transition (EMT), tumor cell invasion, migration and angiogenesis. However, in breast cancer, the clinical relevance of the TAM infiltration according to distinct histologic locations (intratumoral vs. stromal) and hormone receptor status is unclear. We investigated the significance of the levels of TAM infiltration in distinct histologic locations in invasive breast cancer. We also examined the relationship of the TAM levels with the clinicopathologic features of tumors, expression of EMT markers, and clinical outcomes. Finally, we analyzed the prognostic value of TAM levels according to hormone receptor status. High levels of infiltration of intratumoral, stromal and total TAMs were associated with high histologic grade, p53 overexpression, high Ki-67 proliferation index and negative hormone receptor status. Infiltration of TAMs was also correlated with overexpression of vimentin, smooth muscle actin and alteration of β-catenin. Overall, a high level of infiltration of intratumoral TAMs was associated with poor disease-free survival, and was found to be an independent prognostic factor. In subgroup analyses by hormone receptor status, a high level of infiltration of intratumoral TAM was an independent prognostic factor in the hormone receptor-positive subgroup, but not in the hormone-receptor negative subgroup. Our findings suggest that intratumoral TAMs play an important role in tumor progression in breast cancer, especially in the hormone receptor-positive group, and the level of TAM infiltration may be used as a prognostic factor and even a therapeutic target in breast cancer. PMID:25884955

  9. Human oocytes and preimplantation embryos express mRNA for growth hormone receptor.

    PubMed

    Ménézo, Y J; el Mouatassim, S; Chavrier, M; Servy, E J; Nicolet, B

    2003-11-01

    Human genetic expression of growth hormone receptor (GHR) gene was qualitatively analysed using reverse transcription polymerase chain reaction (RT-PCR) in cumulus cells, immature germinal vesicle (GV) and mature metaphase II (MII) stage oocytes and preimplantation human embryos. The transcripts encoding GHR were detected in cumulus cells and also in naked oocytes, either mature or not. In this case, a nested PCR is needed, as for early embryo preimplantation stages, before genomic activation. The GHR gene is highly expressed from the 4-day morula onwards. This suggests that GHR transcription follows a classical scheme associated with genomic activation. It is probable that, in human, growth hormone plays a role in the final stages of oocyte maturation and early embryogenesis as it does for several other mammalian species. PMID:15085728

  10. Internalization and vacuolar targeting of the brassinosteroid hormone receptor BRI1 are regulated by ubiquitination.

    PubMed

    Martins, Sara; Dohmann, Esther M N; Cayrel, Anne; Johnson, Alexander; Fischer, Wolfgang; Pojer, Florence; Satiat-Jeunemaître, Béatrice; Jaillais, Yvon; Chory, Joanne; Geldner, Niko; Vert, Grégory

    2015-01-21

    Brassinosteroids are plant steroid hormones that control many aspects of plant growth and development, and are perceived at the cell surface by the plasma membrane-localized receptor kinase BRI1. Here we show that BRI1 is post-translationally modified by K63 polyubiquitin chains in vivo. Using both artificial ubiquitination of BRI1 and generation of an ubiquitination-defective BRI1 mutant form, we demonstrate that ubiquitination promotes BRI1 internalization from the cell surface and is essential for its recognition at the trans-Golgi network/early endosomes (TGN/EE) for vacuolar targeting. Finally, we demonstrate that the control of BRI1 protein dynamics by ubiquitination is an important control mechanism for brassinosteroid responses in plants. Altogether, our results identify ubiquitination and K63-linked polyubiquitin chain formation as a dual targeting signal for BRI1 internalization and sorting along the endocytic pathway, and highlight its role in hormonally controlled plant development.

  11. Calcium-sensing receptor activation in chronic kidney disease: effects beyond parathyroid hormone control.

    PubMed

    Massy, Ziad A; Hénaut, Lucie; Larsson, Tobias E; Vervloet, Marc G

    2014-11-01

    Secondary hyperparathyroidism (SHPT) is an important complication of advanced chronic kidney disease (CKD). Cinacalcet, an allosteric modulator of the calcium-sensing receptor (CaSR) expressed in parathyroid glands, is the only calcimimetic approved to treat SHPT in patients on dialysis. By enhancing CaSR sensitivity for plasma extracellular calcium (Ca(2+)0), cinacalcet reduces serum parathyroid hormone, Ca(2+)0, and serum inorganic phosphorous concentrations, allowing better control of SHPT and CKD-mineral and bone disorders. Of interest, the CaSR also is expressed in a variety of tissues where its activation regulates diverse cellular processes, including secretion, apoptosis, and proliferation. Thus, the existence of potential off-target effects of cinacalcet cannot be neglected. This review summarizes our current knowledge concerning the potential role(s) of the CaSR expressed in various tissues in CKD-related disorders, independently of parathyroid hormone control.

  12. Targeting the thyroid-stimulating hormone receptor with small molecule ligands and antibodies

    PubMed Central

    Davies, Terry F; Latif, Rauf

    2015-01-01

    Introduction The thyroid-stimulating hormone receptor (TSHR) is the essential molecule for thyroid growth and thyroid hormone production. Since it is also a key autoantigen in Graves’ disease and is involved in thyroid cancer pathophysiology, the targeting of the TSHR offers a logical model for disease control. Areas covered We review the structure and function of the TSHR and the progress in both small molecule ligands and TSHR antibodies for their therapeutic potential. Expert opinion Stabilization of a preferential conformation for the TSHR by allosteric ligands and TSHR antibodies with selective modulation of the signaling pathways is now possible. These tools may be the next generation of therapeutics for controlling the pathophysiological consequences mediated by the effects of the TSHR in the thyroid and other extrathyroidal tissues. PMID:25768836

  13. Hormone stimulation of androgen receptor mediates dynamic changes in DNA methylation patterns at regulatory elements

    PubMed Central

    Dhiman, Vineet K.; Attwood, Kristopher; Campbell, Moray J.; Smiraglia, Dominic J.

    2015-01-01

    DNA methylation is an epigenetic modification that contributes to stable gene silencing by interfering with the ability of transcriptional regulators to bind to DNA. Recent findings have revealed that hormone stimulation of certain nuclear receptors induces rapid, dynamic changes in DNA methylation patterns alongside transcriptional responses at a subset of target loci, over time. However, the ability of androgen receptor (AR) to dynamically regulate gene transcription is relatively under-studied and its role in the regulation of DNA methylation patterns remains to be elucidated. Here we demonstrate in normal prostate cells that hormone stimulated AR activity results in dynamic changes in the transcription rate and DNA methylation patterns at the AR target genes, TIPARP and SGK1. Time-resolved chromatin immunoprecipitation experiments on the SGK1 locus reveals dynamic recruitment of AR and RNA Polymerase II, as well as the recruitment of proteins involved in the DNA demethylation process, TET1 and TDG. Furthermore, the presence of DNA methylation at dynamic regions inhibits protein binding and transcriptional activity of SGK1. These findings establish AR activity as a contributing factor to the dynamic regulation of DNA methylation patterns at target genes in prostate biology and infer further complexity involved in nuclear receptor mediation of transcriptional regulation. PMID:26646795

  14. Freshwater mudsnail (Potamopyrgus antipodarum) estrogen receptor: identification and expression analysis under exposure to (xeno-)hormones.

    PubMed

    Stange, Daniela; Sieratowicz, Agnes; Horres, Ralf; Oehlmann, Jörg

    2012-01-01

    Molluscs are raising attention as ecotoxicological test organisms due to their high diversity and ecological importance. The ovoviviparous prosobranch gastropod Potamopyrgus antipodarum (freshwater mudsnail) responds very sensitively to xenobiotics and has therefore been proposed as OECD standard test organism. Endocrine disrupting chemicals influence the reproduction of P. antipodarum, which can be assessed by embryo numbers in the brood pouch. However, the knowledge about the endocrine system of P. antipodarum is rather limited. The aim of this study was to identify an estrogen receptor in the endocrine system of P. antipodarum and to investigate if this receptor is differentially expressed under exposure to (xeno-)hormones (17α-ethinylestradiol, bisphenol A and 17α-methyltestosterone). The DNA-binding domain of the identified ER-like transcript has an amino acid identity of 92 percent compared to the ER of the gastropod Nucella lapillus (84 percent to human ERα) and 83 percent in the ligand binding domain (38 percent to human ERα). Furthermore, the P. antipodarum ER is transcriptionally regulated as shown by quantitative real-time PCRs of (xeno-)hormone exposed snails. 17α-ethinylestradiol and bisphenol A exposure resulted in a transitory ER-mRNA increase while17α-methyltestosterone caused a transitory reduction of ER-mRNA. In addition the solvent dimethyl sulfoxide had also a modulating effect on the receptor.

  15. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    PubMed

    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. PMID:26976217

  16. Thyroid hormone exerts negative feedback on hypothalamic type 4 melanocortin receptor expression.

    PubMed

    Decherf, Stéphanie; Seugnet, Isabelle; Kouidhi, Soumaya; Lopez-Juarez, Alejandra; Clerget-Froidevaux, Marie-Stéphanie; Demeneix, Barbara A

    2010-03-01

    The type 4 melanocortin receptor MC4R, a key relay in leptin signaling, links central energy control to peripheral reserve status. MC4R activation in different brain areas reduces food intake and increases energy expenditure. Mice lacking Mc4r are obese. Mc4r is expressed by hypothalamic paraventricular Thyrotropin-releasing hormone (TRH) neurons and increases energy usage through activation of Trh and production of the thyroid hormone tri-iodothyronine (T(3)). These facts led us to test the hypothesis that energy homeostasis should require negative feedback by T(3) on Mc4r expression. Quantitative PCR and in situ hybridization showed hyperthyroidism reduces Mc4r mRNA levels in the paraventricular nucleus. Comparative in silico analysis of Mc4r regulatory regions revealed two evolutionarily conserved potential negative thyroid hormone-response elements (nTREs). In vivo ChIP assays on mouse hypothalamus demonstrated association of thyroid hormone receptors (TRs) with a region spanning one nTRE. Further, in vivo gene reporter assays revealed dose-dependent T(3) repression of transcription from the Mc4r promoter in mouse hypothalamus, in parallel with T(3)-dependent Trh repression. Mutagenesis of the nTREs in the Mc4r promoter demonstrated direct regulation by T(3), consolidating the ChIP results. In vivo shRNA knockdown, TR over-expression approaches and use of mutant mice lacking specific TRs showed that both TRalpha and TRbeta contribute to Mc4r regulation. T(3) repression of Mc4r transcription ensures that the energy-saving effects of T(3) feedback on Trh are not overridden by MC4R activation of Trh. Thus parallel repression by T(3) on hypothalamic Mc4r and Trh contributes to energy homeostasis.

  17. Thyroid hormone exerts negative feedback on hypothalamic type 4 melanocortin receptor expression

    PubMed Central

    Decherf, Stéphanie; Seugnet, Isabelle; Kouidhi, Soumaya; Lopez-Juarez, Alejandra; Clerget-Froidevaux, Marie-Stéphanie; Demeneix, Barbara A.

    2010-01-01

    The type 4 melanocortin receptor MC4R, a key relay in leptin signaling, links central energy control to peripheral reserve status. MC4R activation in different brain areas reduces food intake and increases energy expenditure. Mice lacking Mc4r are obese. Mc4r is expressed by hypothalamic paraventricular Thyrotropin-releasing hormone (TRH) neurons and increases energy usage through activation of Trh and production of the thyroid hormone tri-iodothyronine (T3). These facts led us to test the hypothesis that energy homeostasis should require negative feedback by T3 on Mc4r expression. Quantitative PCR and in situ hybridization showed hyperthyroidism reduces Mc4r mRNA levels in the paraventricular nucleus. Comparative in silico analysis of Mc4r regulatory regions revealed two evolutionarily conserved potential negative thyroid hormone-response elements (nTREs). In vivo ChIP assays on mouse hypothalamus demonstrated association of thyroid hormone receptors (TRs) with a region spanning one nTRE. Further, in vivo gene reporter assays revealed dose-dependent T3 repression of transcription from the Mc4r promoter in mouse hypothalamus, in parallel with T3-dependent Trh repression. Mutagenesis of the nTREs in the Mc4r promoter demonstrated direct regulation by T3, consolidating the ChIP results. In vivo shRNA knockdown, TR over-expression approaches and use of mutant mice lacking specific TRs showed that both TRα and TRβ contribute to Mc4r regulation. T3 repression of Mc4r transcription ensures that the energy-saving effects of T3 feedback on Trh are not overridden by MC4R activation of Trh. Thus parallel repression by T3 on hypothalamic Mc4r and Trh contributes to energy homeostasis. PMID:20160073

  18. Patterns of thyroid hormone receptor expression in zebrafish and generation of a novel model of resistance to thyroid hormone action.

    PubMed

    Marelli, Federica; Carra, Silvia; Agostini, Maura; Cotelli, Franco; Peeters, Robin; Chatterjee, Krishna; Persani, Luca

    2016-03-15

    Resistance to thyroid hormone can be due to heterozygous, dominant negative (DN) THRA (RTHα) or THRB (RTHβ) mutations, but the underlying mechanisms are incompletely understood. Here, we delineate the spatiotemporal expression of TH receptors (TRs) in zebrafish and generated morphants expressing equivalent amounts of wild-type and DN TRαs (thraa_MOs) and TRβs (thrb_MOs) in vivo. Both morphants show severe developmental abnormalities. The phenotype of thraa_MOs includes brain and cardiac defects, but normal thyroid volume and tshba expression. A combined modification of dio2 and dio3 expression can explain the high T3/T4 ratio seen in thraa_MOs, as in RTHα. Thrb_MOs show abnormal eyes and otoliths, with a typical RTHβ pattern of thyroid axis. The coexpression of wild-type, but not mutant, human TRs can rescue the phenotype in both morphants. High T3 doses can partially revert the dominant negative action of mutant TRs in morphant fish. Therefore, our morphants recapitulate the RTHα and RTHβ key manifestations representing new models in which the functional consequences of human TR mutations can be rapidly and faithfully evaluated. PMID:26802880

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

    PubMed Central

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

    2011-01-01

    Background 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. Implementation 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. Discussion 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. PMID:21874116

  20. Diversification and coevolution of the ghrelin/growth hormone secretagogue receptor system in vertebrates.

    PubMed

    Tine, Mbaye; Kuhl, Heiner; Teske, Peter R; Tschöp, Matthias H; Jastroch, Martin

    2016-04-01

    The gut hormone ghrelin is involved in numerous metabolic functions, such as the stimulation of growth hormone secretion, gastric motility, and food intake. Ghrelin is modified by ghrelin O-acyltransferase (GOAT) or membrane-bound O-acyltransferase domain-containing 4 (MBOAT4) enabling action through the growth hormone secretagogue receptors (GHS-R). During the course of evolution, initially strong ligand/receptor specificities can be disrupted by genomic changes, potentially modifying physiological roles of the ligand/receptor system. Here, we investigated the coevolution of ghrelin, GOAT, and GHS-R in vertebrates. We combined similarity search, conserved synteny analyses, phylogenetic reconstructions, and protein structure comparisons to reconstruct the evolutionary history of the ghrelin system. Ghrelin remained a single-gene locus in all vertebrate species, and accordingly, a single GHS-R isoform was identified in all tetrapods. Similar patterns of the nonsynonymous (dN) and synonymous (dS) ratio (dN/dS) in the vertebrate lineage strongly suggest coevolution of the ghrelin and GHS-R genes, supporting specific functional interactions and common physiological pathways. The selection profiles do not allow confirmation as to whether ghrelin binds specifically to GOAT, but the ghrelin dN/dS patterns are more similar to those of GOAT compared to MBOAT1 and MBOAT2 isoforms. Four GHS-R isoforms were identified in teleost genomes. This diversification of GHS-R resulted from successive rounds of duplications, some of which remained specific to the teleost lineage. Coevolution signals are lost in teleosts, presumably due to the diversification of GHS-R but not the ghrelin gene. The identification of the GHS-R diversity in teleosts provides a molecular basis for comparative studies on ghrelin's physiological roles and regulation, while the comparative sequence and structure analyses will assist translational medicine to determine structure-function relationships of the

  1. Simulating alpha/beta selectivity at the human thyroid hormone receptor: consensus scoring using multidimensional QSAR.

    PubMed

    Vedani, Angelo; Zumstein, Martin; Lill, Markus A; Ernst, Beat

    2007-01-01

    We present a consensus-scoring study on the human thyroid hormone receptor alpha and beta using two receptor-modeling concepts (software Quasar and Raptor) that are based on multidimensional QSAR and allow for the explicit simulation of induced fit. The binding mode of 82 agonists and indirect antagonists, spanning an activity range of seven orders of magnitude in K(i), was identified through flexible docking to the respective X-ray crystal structures (Yeti software) and represented by a 4D data set with up to four conformations per compound. The receptor surrogates for the thyroid alpha receptor converged at a cross-validated r(2) of 0.846/0.919 (64 training compounds; for Quasar and Raptor, respectively) and yielded a predictive r(2) of 0.812/0.814 (18 test compounds); the models for the thyroid beta receptor resulted in a cross-validated r(2) of 0.823/0.909 and a predictive r(2) of 0.665/0.796, respectively. Consensus was achieved as, on average, the calculated activities of the training set differ only by a factor of 2.2 in K(i) and those of the test set by a factor of 2.8 when predicted by Quasar and Raptor, respectively.

  2. Macrophage/cancer cell interactions mediate hormone resistance by a nuclear receptor derepression pathway.

    PubMed

    Zhu, Ping; Baek, Sung Hee; Bourk, Eliot M; Ohgi, Kenneth A; Garcia-Bassets, Ivan; Sanjo, Hideki; Akira, Shizuo; Kotol, Paul F; Glass, Christopher K; Rosenfeld, Michael G; Rose, David W

    2006-02-10

    Defining the precise molecular strategies that coordinate patterns of transcriptional responses to specific signals is central for understanding normal development and homeostasis as well as the pathogenesis of hormone-dependent cancers. Here we report specific prostate cancer cell/macrophage interactions that mediate a switch in function of selective androgen receptor antagonists/modulators (SARMs) from repression to activation in vivo. This is based on an evolutionarily conserved receptor N-terminal L/HX7LL motif, selectively present in sex steroid receptors, that causes recruitment of TAB2 as a component of an N-CoR corepressor complex. TAB2 acts as a sensor for inflammatory signals by serving as a molecular beacon for recruitment of MEKK1, which in turn mediates dismissal of the N-CoR/HDAC complex and permits derepression of androgen and estrogen receptor target genes. Surprisingly, this conserved sensor strategy may have arisen to mediate reversal of sex steroid-dependent repression of a limited cohort of target genes in response to inflammatory signals, linking inflammatory and nuclear receptor ligand responses to essential reproductive functions.

  3. Effect of reproductive hormones and selective estrogen receptor modulators on mood during menopause.

    PubMed

    Soares, Claudio N; Poitras, Jennifer R; Prouty, Jennifer

    2003-01-01

    Periods of intense hormonal fluctuations have been associated with heightened prevalence and exacerbation of underlying psychiatric illness, particularly the occurrence of premenstrual dysphoria, puerperal depression and depressive symptoms during perimenopause. It has been speculated that sex steroids such as estrogens, progestogens, testosterone and dehydroepiandrosterone (DHEA) exert a significant modulation of brain functioning, possibly through interactions with various neurotransmitter systems. It is therefore intuitive that abrupt alterations of these hormones would interfere with mood and behaviour. On the other hand, accumulating data suggest that hormonal interventions may also promote relief or even remission of depressive symptoms, as already demonstrated in studies with patients experiencing postpartum depression and perimenopausal depressive disorders. The extent to which perimenopause, alone, may increase the risk for depression is unclear. However, existing data strongly suggest that some women are particularly vulnerable to developing significant physical and psychological disturbances when entering perimenopause. This article reviews the effect of sex hormones and selective estrogen receptor modulators (SERMs) on mood among peri- and postmenopausal women. There are preliminary, though promising, data on the use of estradiol (particularly transdermal estradiol) to alleviate depression during perimenopause, use of a combination of estrogens and selective serotonin reuptake inhibitors for depression during the postmenopausal period, and the use of testosterone to improve psychological well-being and increase libido among women with induced menopause. Further studies would help to better delineate the usage of hormones as an antidepressant strategy (monotherapy or augmenting treatment) for peri- and postmenopausal women. A brief review of some nonhormonal interventions for the treatment of menopause-related symptoms that may significantly affect a

  4. Thyroid-stimulating hormone receptor in brown adipose tissue is involved in the regulation of thermogenesis.

    PubMed

    Endo, Toyoshi; Kobayashi, Tetsuro

    2008-08-01

    C.RF- Tshr(hyt/hyt) mice have a mutated thyroid-stimulating hormone receptor (TSHR), and, without thyroid hormone supplementation, these mice develop severe hypothyroidism. When hypothyroid Tshr(hyt/hyt) mice were exposed to cold (4 degrees C), rectal temperature rapidly dropped to 23.9 +/- 0.40 degrees C at 90 min, whereas the wild-type mice temperatures were 37.0 +/- 0.15 degrees C. When we carried out functional rat TSHR gene transfer in the brown adipose tissues by plasmid injection combined with electroporation, there was no effect on the serum levels of thyroxine, although rectal temperature of the mice transfected with pcDNA3.1/Zeo-rat TSHR 90 min after cold exposure remained at 34.6 +/- 0.34 degrees C, which was significantly higher than that of Tshr(hyt/hyt) mice. Transfection of TSHR cDNA increased mRNA and protein levels of uncoupling protein-1 (UCP-1) in brown adipose tissues, and the weight ratio of brown adipose tissue to overall body weight also increased. Exogenous thyroid hormone supplementation to Tshr(hyt/hyt) mice restored rectal temperature 90 min after exposure to cold (36.8 +/- 0.10 degrees C). These results indicate that not only thyroid hormone but also thyroid-stimulating hormone (TSH)/TSHR are involved in the expression mechanism of UCP-1 in mouse brown adipose tissue. TSH stimulates thermogenesis and functions to protect a further decrease in body temperature in the hypothyroid state. PMID:18559984

  5. Isolation and Functional Characterization of Calcitonin-Like Diuretic Hormone Receptors in Rhodnius prolixus

    PubMed Central

    Zandawala, Meet; Li, Shizhong; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Orchard, Ian

    2013-01-01

    Several families of diuretic hormones exist in insects, one of which is the calcitonin-like diuretic hormone (CT/DH) family. CT/DH mediates its effects by binding to family B G-protein coupled receptors (GPCRs). Here we isolate and functionally characterize two R. prolixus CT/DH receptor paralogs (Rhopr-CT/DH-R1 and Rhopr-CT/DH-R2) using a novel heterologous assay utilizing a modified human embryonic kidney 293 (HEK293) cell line. Rhopr-CT/DH-R1 is orthologous to the previously characterized D. melanogaster CT/DH receptor (CG17415) while Rhopr-CT/DH-R2 is orthologous to the D. melanogaster receptor (CG4395), an orphan receptor whose ligand was unknown until now. We determine the cDNA sequences of three splice variants encoding Rhopr-CT/DH-R1 (Rhopr-CT/DH-R1-A, Rhopr-CT/DH-R1-B and Rhopr-CT/DH-R1-C) and two splice variants encoding Rhopr-CT/DH-R2 (Rhopr-CT/DH-R2-A and Rhopr-CT/DH-R2-B). Rhopr-CT/DH-R1-A and Rhopr-CT/DH-R2-A encode truncated receptors that lack six and seven of the characteristic seven transmembrane domains, respectively. Rhopr-CT/DH-R1-B and Rhopr-CT/DH-R1-C, which only differ by 2 amino acids in their C-terminal domain, can both be activated by Rhopr-CT/DH at equal sensitivities (EC50 = 200-300nM). Interestingly, Rhopr-CT/DH-R2-B is much more sensitive to Rhopr-CT/DH (EC50 = 15nM) compared to Rhopr-CT/DH-R1-B/C and also yields a much greater response (amplitude) in our heterologous assay. This is the first study to reveal that insects possess at least two CT/DH receptors, which may be functionally different. Quantitative PCR demonstrates that Rhopr-CT/DH-R1 and Rhopr-CT/DH-R2 have distinct expression patterns, with both receptors expressed centrally and peripherally. Moreover, the expression analysis also identified novel target tissues for this neuropeptide, including testes, ovaries and prothoracic glands, suggesting a possible role for Rhopr-CT/DH in reproductive physiology and development. PMID:24312424

  6. Correlation between hormone dependency and the regulation of epidermal growth factor receptor by tumor promoters in human mammary carcinoma cells.

    PubMed Central

    Roos, W; Fabbro, D; Küng, W; Costa, S D; Eppenberger, U

    1986-01-01

    The effects of the tumor promoter phorbol 12-tetradecanoate 13-acetate (TPA) on the epidermal growth factor (EGF) receptor levels were investigated in hormone-dependent (MCF-7, T-47-D, and ZR-75-1) and hormone-independent (MDA-MB-231, HBL-100, and BT-20) human mammary carcinoma cell lines. In the absence of TPA, hormone-independent cell lines contained high concentrations of low-affinity EGF receptors (apparent Kd = 8 X 10(-10) M), whereas hormone-dependent cell lines exhibited low concentrations of high-affinity receptors (apparent Kd = 1 X 10(-10) M). TPA causes a change of the receptor from a high- to the low-affinity state in hormone-dependent cell lines (MCF-7, T-47-D, and ZR-75-1), as well as in the hormone-independent HBL-100, whereas the affinity remained unchanged in MDA-MB-231 and BT-20 cells. In addition, progesterone receptor levels are decreased after TPA treatment in the hormone-dependent cell lines MCF-7, T-47-D, and ZR-75-1, whereas the estrogen receptor levels remained unchanged. Tumor promoters such as TPA or teleocidin inhibited the proliferation of these cell lines at concentrations above 10 microM with the exception of the T-47-D cells. The most sensitive cell line towards growth inhibition by tumor promoter was the hormone-dependent MCF-7 cell line. Evaluation of different TPA analogs indicated a positive correlation between the growth-inhibitory effects and their ability to stimulate the subcellular redistribution of protein kinase C activity in MCF-7 cells. These data suggest a protein kinase C-mediated down-regulation of the progesterone receptor concentration and of the EGF receptor affinity, which is supposed to mediate the mitogenic response. Furthermore, these results support the hypothesis that the tumor-derived growth factors induced by estradiol act via the EGF receptor in hormone-dependent mammary carcinoma cells. PMID:3006036

  7. The relationship between growth hormone polymorphism and growth hormone receptor genes with milk yield and reproductive performance in Holstein dairy cows

    PubMed Central

    Hadi, Z; Atashi, H; Dadpasand, M; Derakhshandeh, A; Ghahramani Seno, M. M

    2015-01-01

    The aim of this study was to investigate the potential association between growth hormone GH/AluI and growth hormone receptor GHR/AluI polymorphisms with milk yield and reproductive performances in Holstein dairy cows in Iran. Blood samples of 150 Holstein cows were collected and their genomic DNA was extracted using Gene-Fanavaran DNA extracting kit. Fragments of the 428 bp of exon 5 growth hormone (GH) gene and the 342 bp of exon 10 growth hormone receptor (GHR) gene were amplified using the polymerase chain reaction (PCR) method. PCR products were digested by the AluI restriction enzyme and electrophoresed on 3% agarose gel. Continuous and categorical data were analyzed using linear mixed models through Proc MIXED and logistic regression models through Proc GENMOD of SAS software, respectively. The results showed no relationship between the examined traits and GH/AluI or GHR/AluI genes. A significant relationship was found between GH/AluI polymorphism and dystocia, but the presence of the GH-L allele reduced the incidence of dystocia. The results suggest that the GH-LL genotype reduces dystocia probably by affecting the release of growth hormone; nevertheless, further studies will be needed to examine the relationship between dystocia and GH genotypes. PMID:27175183

  8. Gonadotrophin-releasing activity of neurohypophysial hormones: II. The pituitary oxytocin receptor mediating gonadotrophin release differs from that of corticotrophs.

    PubMed

    Evans, J J; Catt, K J

    1989-07-01

    Neurohypophysial hormones stimulate gonadotrophin release from dispersed rat anterior pituitary cells in vitro, acting through receptors distinct from those which mediate the secretory response to gonadotrophin-releasing hormone (GnRH). The LH response to oxytocin was not affected by the presence of the phosphodiesterase inhibitor, methyl isobutylxanthine, but was diminished in the absence of extracellular calcium and was progressively increased as the calcium concentration in the medium was raised to normal. In addition, the calcium channel antagonist, nifedipine, suppressed oxytocin-stimulated secretion of LH. It is likely that the mechanisms of LH release induced by GnRH and neurohypophysial hormones are similar, although stimulation of gonadotrophin secretion is mediated by separate receptor systems. Oxytocin was more active than vasopressin in releasing LH, but less active in releasing ACTH. The highly selective oxytocin agonist, [Thr4,Gly7]oxytocin, elicited concentration-dependent secretion of LH but had little effect on corticotrophin secretion. The neurohypophysial hormone antagonist analogues, [d(CH2)5Tyr(Me)2]vasopressin, [d(CH2)5Tyr(Me)2,Orn8]vasotocin and [d(CH2)5D-Tyr(Et)2Val4,Cit8]vasopressin, inhibited the LH response to both oxytocin and vasopressin. However, [d(CH2)5Tyr(Me)2]vasopressin was much less effective in inhibiting the ACTH response to the neurohypophysial hormones, and [d(CH2)5Tyr-(Me)2,Orn8]vasotocin and [d(CH2)5D-Tyr(Et)2,Val4,Cit8]vasopressin exhibited no inhibitory activity against ACTH release. Thus, agonist and antagonist analogues of neurohypophysial hormones display divergent activities with regard to LH and ACTH responses, and the neuropeptide receptor mediating gonadotroph activation is clearly different from that on the corticotroph. Whereas the corticotroph receptor is a vasopressin-type receptor an oxytocin-type receptor is responsible for gonadotrophin release by neurohypophysial hormones.

  9. Perfluorooctane sulfonate (PFOS) affects hormone receptor activity, steroidogenesis, and expression of endocrine-related genes in vitro and in vivo.

    PubMed

    Du, Guizhen; Hu, Jialei; Huang, Hongyu; Qin, Yufeng; Han, Xiumei; Wu, Di; Song, Ling; Xia, Yankai; Wang, Xinru

    2013-02-01

    Perfluorooctane sulfonate (PFOS) is a widespread and persistent chemical in the environment. We investigated the endocrine-disrupting effects of PFOS using a combination of in vitro and in vivo assays. Reporter gene assays were used to detect receptor-mediated (anti-)estrogenic, (anti-)androgenic, and (anti-)thyroid hormone activities. The effect of PFOS on steroidogenesis was assessed both at hormone levels in the supernatant and at expression levels of hormone-induced genes in the H295R cell. A zebrafish-based short-term screening method was developed to detect the effect of PFOS on endocrine function in vivo. The results indicate that PFOS can act as an estrogen receptor agonist and thyroid hormone receptor antagonist. Exposure to PFOS decreased supernatant testosterone (T), increased estradiol (E2) concentrations in H295R cell medium and altered the expression of several genes involved in steroidogenesis. In addition, PFOS increased early thyroid development gene (hhex and pax8) expression in a concentration-dependent manner, decreased steroidogenic enzyme gene (CYP17, CYP19a, CYP19b) expression, and changed the expression pattern of estrogen receptor production genes (esr1, esr2b) after 500 µg/L PFOS treatment in zebrafish embryos. These results indicate that PFOS has the ability to act as an endocrine disruptor both in vitro and in vivo by disrupting the function of nuclear hormone receptors, interfering with steroidogenesis, and altering the expression of endocrine-related genes in zebrafish embryo.

  10. Perfluorooctane sulfonate (PFOS) affects hormone receptor activity, steroidogenesis, and expression of endocrine-related genes in vitro and in vivo.

    PubMed

    Du, Guizhen; Hu, Jialei; Huang, Hongyu; Qin, Yufeng; Han, Xiumei; Wu, Di; Song, Ling; Xia, Yankai; Wang, Xinru

    2013-02-01

    Perfluorooctane sulfonate (PFOS) is a widespread and persistent chemical in the environment. We investigated the endocrine-disrupting effects of PFOS using a combination of in vitro and in vivo assays. Reporter gene assays were used to detect receptor-mediated (anti-)estrogenic, (anti-)androgenic, and (anti-)thyroid hormone activities. The effect of PFOS on steroidogenesis was assessed both at hormone levels in the supernatant and at expression levels of hormone-induced genes in the H295R cell. A zebrafish-based short-term screening method was developed to detect the effect of PFOS on endocrine function in vivo. The results indicate that PFOS can act as an estrogen receptor agonist and thyroid hormone receptor antagonist. Exposure to PFOS decreased supernatant testosterone (T), increased estradiol (E2) concentrations in H295R cell medium and altered the expression of several genes involved in steroidogenesis. In addition, PFOS increased early thyroid development gene (hhex and pax8) expression in a concentration-dependent manner, decreased steroidogenic enzyme gene (CYP17, CYP19a, CYP19b) expression, and changed the expression pattern of estrogen receptor production genes (esr1, esr2b) after 500 µg/L PFOS treatment in zebrafish embryos. These results indicate that PFOS has the ability to act as an endocrine disruptor both in vitro and in vivo by disrupting the function of nuclear hormone receptors, interfering with steroidogenesis, and altering the expression of endocrine-related genes in zebrafish embryo. PMID:23074026

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

    SciTech Connect

    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.

  12. Evolution of Parathyroid Hormone Receptor Family and Their Ligands in Vertebrate

    PubMed Central

    On, Jason S. W.; Chow, Billy K. C.; Lee, Leo T. O.

    2015-01-01

    The presence of the parathyroid hormones in vertebrates, including PTH, PTH-related peptide (PTHrP), and tuberoinfundibular peptide of 39 residues (TIP39), has been proposed to be the result of two rounds of whole genome duplication in the beginning of vertebrate diversification. Bioinformatics analyses, in particular chromosomal synteny study and the characterization of the PTH ligands and their receptors from various vertebrate species, provide evidence that strongly supports this hypothesis. In this mini-review, we summarize recent advances in studies regarding the molecular evolution and physiology of the PTH ligands and their receptors, with particular focus on non-mammalian vertebrates. In summary, the PTH family of peptides probably predates early vertebrate evolution, indicating a more ancient existence as well as a function of these peptides in invertebrates. PMID:25806022

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

    SciTech Connect

    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.

  14. Effects of perinatal exposure to low-dose cadmium on thyroid hormone-related and sex hormone receptor gene expressions in brain of offspring.

    PubMed

    Ishitobi, Hiromi; Mori, Kohki; Yoshida, Katsumi; Watanabe, Chiho

    2007-07-01

    Perinatal cadmium (Cd) exposure has been shown to alter behaviors and reduce learning ability of offspring. A few studies have shown that Cd reduced serum thyroid hormones (THs), which are important for brain development during the perinatal period. Brain specific genes, neurogranin (RC3) and myelin basic protein (BMP), are known to be regulated by TH through TH receptors (TR). It has been suggested that RC3 may play roles in memory and learning. In addition, Cd has been suggested to have estrogen-like activity. To evaluate the effects of perinatal low-dose exposure to Cd on thyroid hormone-related gene (RC3, TR-beta1, MBP, RAR-beta) and sex hormone receptor gene (ER-alpha, ER-beta and PgR) expressions in the brain and on behaviors of offspring, mice were administered with 10ppm Cd (from gestational day 1 to postnatal day 10) and/or 0.025% methimazole (MMI; anti-thyroid drug) (from gestational day 12 to postnatal day 10) in drinking water. Also, 0.1% MMI was administered as a positive control (high MMI group). RC3 mRNA expression was reduced in the female brain of combined exposure and high MMI groups and was negatively correlated with the activity in the open-field. ER-alpha, ER-beta and PgR mRNA expressions were decreased in male and female Cd, and female Cd+MMI groups, respectively; among these changes the reduced expression of PgR was opposite to estrogenic action. These results suggested that perinatal exposure to Cd disrupted the gene expressions of sex hormone receptors, which could not be considered to be a result of estrogenic action. Our study indicates that alteration in the gene expressions of RC3 and sex hormone receptors in the brain induced by perinatal Cd and MMI exposure might be one mechanism of developmental toxicity of Cd. PMID:17408746

  15. Evidence for impaired retinoic acid receptor-thyroid hormone receptor AF-2 cofactor activity in human lung cancer.

    PubMed Central

    Moghal, N; Neel, B G

    1995-01-01

    Retinoic acid (RA) is required for normal airway epithelial cell growth and differentiation both in vivo and in vitro. One of the earliest events following the exposure of bronchial epithelial cells to RA is the strong induction of RA receptor beta (RAR beta) mRNA. Previous work established that many lung cancer cell lines and primary tumors display abnormal RAR beta mRNA expression, most often absence or weak expression of the RAR beta 2 isoform, even after RA treatment. Restoration of RAR beta 2 into RAR beta-negative lung cancer cell lines has been reported to inhibit tumorigenicity. Since RAR beta 2 inactivation may contribute to lung cancer, we have investigated the molecular mechanism of defective RAR beta 2 expression. Nuclear run-on assays and transient transfections with RAR beta 2 promoter constructs indicate the presence of trans-acting transcriptional defects in most lung cancer cell lines, which map to the RA response element (RARE). These defects cannot be complemented by RAR-retinoid X receptor cotransfection and can be separated into two types: (i) one affecting transcription from direct repeat RAREs, but not palindromic RAREs, and (ii) another affecting transcription from both types of RARE. Studies using chimeras between RAR alpha, TR alpha, and other transcription factors suggest the existence of novel RAR-thyroid hormone receptor AF-2-specific cofactors, which are necessary for high levels of transcription. Furthermore, these factors may be frequently inactivated in human lung cancer. PMID:7791800

  16. Cannabinoid CB1 receptor mediates glucocorticoid effects on hormone secretion induced by volume and osmotic changes.

    PubMed

    Ruginsk, S G; Uchoa, E T; Elias, L L K; Antunes-Rodrigues, J

    2012-02-01

    The present study provides the first in vivo evidence that the cannabinoid CB(1) receptor mediates the effects of dexamethasone on hormone release induced by changes in circulating volume and osmolality. Male adult rats were administered with the CB(1) receptor antagonist rimonabant (10 mg/Kg, p.o.), followed or not in 1 hour by dexamethasone (1 mg/Kg, i.p.). Extracellular volume expansion (EVE, 2 mL/100 g of body weight, i.v.) was performed 2 hours after dexamethasone or vehicle treatment using either isotonic (I-EVE, 0.15 mol/L) or hypertonic (H-EVE, 0.30 mol/L) NaCl solution. Five minutes after EVE, animals were decapitated and trunk blood was collected for all plasma measurements. Rimonabant potentiated oxytocin (OT) secretion induced by H-EVE and completely reversed the inhibitory effects of dexamethasone in response to the same stimulus. These data suggest that glucocorticoid modulation of OT release is mediated by the CB(1) receptor. Although dexamethasone did not affect vasopressin (AVP) secretion induced by H-EVE, the administration of rimonabant potentiated AVP release in response to the same stimulus, supporting the hypothesis that the CB(1) receptor regulates AVP secretion independently of glucocorticoid-mediated signalling. Dexamethasone alone did not affect atrial natriuretic peptide (ANP) release stimulated by I-EVE or H-EVE. However, pretreatment with rimonabant potentiated ANP secretion induced by H-EVE, suggesting a possible role for the CB(1) receptor in the control of peripheral factors that modulate cardiovascular function. Rimonabant also reversed the inhibitory effects of dexamethasone on H-EVE-induced corticosterone secretion, reinforcing the hypothesis that the CB(1) receptor may be involved in the negative feedback exerted by glucocorticoids on the activity of the hypothalamic-pituitary-adrenal axis. Collectively, the results of the present study indicate that the CB(1) receptor modulates neurohypophyseal hormone secretion and

  17. Delta opioid receptors are involved in morphine-induced inhibition of luteinizing hormone releasing hormone in SK-N-SH cells.

    PubMed

    Bennett, Lunawati; Ratka, Anna

    2003-10-01

    Opioids play an important role in the regulation of lutenizing hormone releasing hormone (LHRH). In the present study, we attempted to find out the subtype of opioid receptors involved in the inhibitory effect of morphine on LHRH. Experiments were conducted on SK-N-SH neuroblastoma cells that express both micro and delta opioid receptors, LHRH mRNA, and release the LHRH peptide. Enzyme-linked immunosorbent assay (ELISA) was employed to measure the levels of LHRH. LHRH level was decreased by 1000 microM of morphine regardless of the duration of exposure or differentiation status of the SK-N-SH cells and was not reversed by naloxone. Selective antagonism of micro opioid receptors, but not delta opioid receptors, allowed lower concentrations (1-100 microM) of morphine to inhibit LHRH. The results of this study imply that (1) delta opioid receptors may mediate the inhibitory effect of lower concentrations of morphine on LHRH levels in SK-N-SH cells, and (2) inhibition of LHRH level by high concentrations of morphine may involve systems other than opioid receptors.

  18. Juvenile hormone receptors in insect larval epidermis: Identification by photoaffinity labeling

    SciTech Connect

    Palli, S.R.; Osir, E.O.; Edwards, M.; Hiruma, K.; Riddiford, L.M. ); Eng, W.; Boehm, M.F.; Kulscar, P.; Ujvary, I.; Prestwich, G.D. )

    1990-01-01

    Tritiated photoaffinity analogs of the natural lepidopteran juvenile hormones, JH I and II (epoxy({sup 3}H)bishomofarnesyl diazoacetate (({sup 3}H)EHDA) and epoxy({sup 3}H)homofarnesyl diazoacetate (({sup 3}H)EHDA)), and of the JH analog methoprene (({sup 3}H)methoprene diazoketone (({sup 3}H)MDK)) were synthesized and used to identify specific JH binding proteins in the larval epidermis of the tobacco hornworm (Manduca sexta). EBDA and EHDA specifically photolabeled a 29-kDa nuclear protein (pI 5.8). This protein and a second 29-kDa protein (pI 6.0) were labeled by MDK, but excess unlabeled methoprene or MDK only prevented binding to the latter. These 29-kDa proteins are also present in larval fat body but not in epidermis from either wandering stage or allatectomized larvae, which lack high-affinity JH binding sites. A 29-kDa nuclear protein with the same developmental specificity as this JH binder bound the DNA of two larval endocuticle genes. A 38-kDa cytosolic protein was also specifically photolabeled by these photoaffinity analogs. The 29-kDa nuclear protein is likely the high-affinity receptor for JH that mediates its genomic action, whereas the 38-kDa cytosolic protein may serve as an intracellular carrier for these highly lipophilic hormones and hormone analogs.

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

    PubMed Central

    Jiang, Hongbo; Wei, Zhaojun; Nachman, Ronald J.; Park, Yoonseong

    2013-01-01

    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 its ligand specificities in a heterologous reporter system. HzDHr was expressed in Chinese Hamster Ovary (CHO) cells, which were co-transfected with the aequorin reporter, and was used to measure the ligand activities. A total of 68 chemicals, including natural DH analogs and structurally similar peptide mimetics, were tested for agonistic and antagonistic activities. Several peptide mimetics with a 2-amino-7-bromofluorene-succinoyl (2Abf-Suc) N-terminal modification showed strong agonistic activities; these mimetics included 2Abf-Suc-F[dA]PRLamide, 2Abf-Suc-F[dR]PRLamide, 2Abf-Suc-FKPRLamide and 2Abf-Suc-FGPRLamide. Antagonistic activity was found in the ecdysis triggering hormone in Drosophila melanogaster (FFLKITKNVPRLamide). Interestingly, HzDHr does not discriminate between DH (WFGPRLamide C-terminal motif) and another closely related endogenous peptide, pyrokinin 1 (FXPRXamide; a C-terminal motif that is separate from WFGPRLamide). We provide large-scale in vitro data that serve as a reference for the development of agonists and antagonists to disrupt the DH signaling pathway. PMID:24257143

  20. Developing in vitro reporter gene assays to assess the hormone receptor activities of chemicals frequently detected in drinking water.

    PubMed

    Sun, Hong; Si, Chaozong; Bian, Qian; Chen, Xiaodong; Chen, Liansheng; Wang, Xinru

    2012-08-01

    The present study intended to develop receptor-mediated luciferase reporter gene assays to evaluate and compare the estrogen receptor (ER), androgen receptor (AR) and thyroid hormone receptor (TR) activities of target chemicals. Di-2-ethylhexyl-phthalate (DEHP), chlorpyrifos (CPF), 2,4-dichlorophenoxyacetic acid (2,4-D) and bisphenol A (BPA) are some of the most common contaminants in drinking water and are frequently detected in China and worldwide. The chemicals were tested at concentrations of 0.1, 1, 10 and 100 times their maximum contaminant level in drinking water. The results showed that BPA possessed various activities on ER, AR and TR. DEHP and CPF could suppress 17β-estradiol or testosterone activity with different potencies, and DEHP possessed weaker anti-thyroid hormone activity. 2,4-D showed no agonist or antagonist activity against these hormone receptors, but it significantly enhanced the activity of testosterone through AR. Furthermore, the mixture of DEHP and CPF exhibited stronger ER and AR antagonist activities than each single component alone, but their combined effects were less than the expected effects based on the additive model. These results implied that the transcription activation mediated by hormone receptors was the potential endocrine-disrupting mechanism of the test chemicals. Our study also provided useful tools for evaluation of their endocrine disrupting activity.

  1. Host target modification as a strategy to counter pathogen hijacking of the jasmonate hormone receptor.

    PubMed

    Zhang, Li; Yao, Jian; Withers, John; Xin, Xiu-Fang; Banerjee, Rahul; Fariduddin, Qazi; Nakamura, Yoko; Nomura, Kinya; Howe, Gregg A; Boland, Wilhelm; Yan, Honggao; He, Sheng Yang

    2015-11-17

    In the past decade, characterization of the host targets of pathogen virulence factors took a center stage in the study of pathogenesis and disease susceptibility in plants and humans. However, the impressive knowledge of host targets has not been broadly exploited to inhibit pathogen infection. Here, we show that host target modification could be a promising new approach to "protect" the disease-vulnerable components of plants. In particular, recent studies have identified the plant hormone jasmonate (JA) receptor as one of the common targets of virulence factors from highly evolved biotrophic/hemibiotrophic pathogens. Strains of the bacterial pathogen Pseudomonas syringae, for example, produce proteinaceous effectors, as well as a JA-mimicking toxin, coronatine (COR), to activate JA signaling as a mechanism to promote disease susceptibility. Guided by the crystal structure of the JA receptor and evolutionary clues, we succeeded in modifying the JA receptor to allow for sufficient endogenous JA signaling but greatly reduced sensitivity to COR. Transgenic Arabidopsis expressing this modified receptor not only are fertile and maintain a high level of insect defense, but also gain the ability to resist COR-producing pathogens Pseudomonas syringae pv. tomato and P. syringae pv. maculicola. Our results provide a proof-of-concept demonstration that host target modification can be a promising new approach to prevent the virulence action of highly evolved pathogens. PMID:26578782

  2. New Frontier in Glycoprotein Hormones and Their Receptors Structure–Function

    PubMed Central

    Szkudlinski, Mariusz W.

    2015-01-01

    Last two decades of structure–function studies performed in numerous laboratories provided substantial progress in understanding basic science, physiological, pathophysiological, pharmacological, and comparative aspects of glycoprotein hormones (GPHs) and their cognate receptors. Multiple concepts and models developed based on experimental data in the past stood the test of time and have been, at least in part, confirmed and/or remained compatible with the new structures resolved at the atomic level. Major advances in understanding of the ligand–receptor relationships are heralding the dawn of a new era for GPHs and their receptors, although many basic questions still remain unanswered. This article examines retrospectively several basic science aspects of GPH super-agonists and related “biosuperiors” in a broader context of the advances in the ligand–receptor structure–function relationships and new mechanistic models generated based on the structure elucidation. Due to selective focus of my comments and perspectives in certain parts, the reader is directed to the most relevant publications and reviews in the field for more comprehensive analyses. PMID:26539160

  3. Host target modification as a strategy to counter pathogen hijacking of the jasmonate hormone receptor

    PubMed Central

    Zhang, Li; Yao, Jian; Withers, John; Xin, Xiu-Fang; Banerjee, Rahul; Fariduddin, Qazi; Nakamura, Yoko; Nomura, Kinya; Howe, Gregg A.; Boland, Wilhelm; Yan, Honggao; He, Sheng Yang

    2015-01-01

    In the past decade, characterization of the host targets of pathogen virulence factors took a center stage in the study of pathogenesis and disease susceptibility in plants and humans. However, the impressive knowledge of host targets has not been broadly exploited to inhibit pathogen infection. Here, we show that host target modification could be a promising new approach to “protect” the disease-vulnerable components of plants. In particular, recent studies have identified the plant hormone jasmonate (JA) receptor as one of the common targets of virulence factors from highly evolved biotrophic/hemibiotrophic pathogens. Strains of the bacterial pathogen Pseudomonas syringae, for example, produce proteinaceous effectors, as well as a JA-mimicking toxin, coronatine (COR), to activate JA signaling as a mechanism to promote disease susceptibility. Guided by the crystal structure of the JA receptor and evolutionary clues, we succeeded in modifying the JA receptor to allow for sufficient endogenous JA signaling but greatly reduced sensitivity to COR. Transgenic Arabidopsis expressing this modified receptor not only are fertile and maintain a high level of insect defense, but also gain the ability to resist COR-producing pathogens Pseudomonas syringae pv. tomato and P. syringae pv. maculicola. Our results provide a proof-of-concept demonstration that host target modification can be a promising new approach to prevent the virulence action of highly evolved pathogens. PMID:26578782

  4. Dopamine D1 and corticotrophin-releasing hormone type-2α receptors assemble into functionally interacting complexes in living cells

    PubMed Central

    Fuenzalida, J; Galaz, P; Araya, K A; Slater, P G; Blanco, E H; Campusano, J M; Ciruela, F; Gysling, K

    2014-01-01

    Background and Purpose Dopamine and corticotrophin-releasing hormone (CRH; also known as corticotrophin-releasing factor) are key neurotransmitters in the interaction between stress and addiction. Repeated treatment with cocaine potentiates glutamatergic transmission in the rat basolateral amygdala/cortex pathway through a synergistic action of D1-like dopamine receptors and CRH type-2α receptors (CRF2α receptors). We hypothesized that this observed synergism could be instrumented by heteromers containing the dopamine D1 receptor and CRF2α receptor. Experimental Approach D1/CRF2α receptor heteromerization was demonstrated in HEK293T cells using co-immunoprecipitation, BRET and FRET assays, and by using the heteromer mobilization strategy. The ability of D1 receptors to signal through calcium, when singly expressed or co-expressed with CRF2α receptors, was evaluated by the calcium mobilization assay. Key Results D1/CRF2α receptor heteromers were observed in HEK293T cells. When singly expressed, D1 receptors were mostly located at the cell surface whereas CRF2α receptors accumulated intracellularly. Interestingly, co-expression of both receptors promoted D1 receptor intracellular and CRF2α receptor cell surface targeting. The heteromerization of D1/CRF2α receptors maintained the signalling through cAMP of both receptors but switched D1 receptor signalling properties, as the heteromeric D1 receptor was able to mobilize intracellular calcium upon stimulation with a D1 receptor agonist. Conclusions and Implications D1 and CRF2α receptors are capable of heterodimerization in living cells. D1/CRF2α receptor heteromerization might account, at least in part, for the complex physiological interactions established between dopamine and CRH in normal and pathological conditions such as addiction, representing a new potential pharmacological target. PMID:25073922

  5. Thyroid hormone receptor alpha1 follows a cooperative CRM1/calreticulin-mediated nuclear export pathway.

    PubMed

    Grespin, Matthew E; Bonamy, Ghislain M C; Roggero, Vincent R; Cameron, Nicole G; Adam, Lindsay E; Atchison, Andrew P; Fratto, Victoria M; Allison, Lizabeth A

    2008-09-12

    The thyroid hormone receptor alpha1 (TRalpha) exhibits a dual role as an activator or repressor of its target genes in response to thyroid hormone (T(3)). Previously, we have shown that TRalpha, formerly thought to reside solely in the nucleus bound to DNA, actually shuttles rapidly between the nucleus and cytoplasm. An important aspect of the shuttling activity of TRalpha is its ability to exit the nucleus through the nuclear pore complex. TRalpha export is not sensitive to treatment with the CRM1-specific inhibitor leptomycin B (LMB) in heterokaryon assays, suggesting a role for an export receptor other than CRM1. Here, we have used a combined approach of in vivo fluorescence recovery after photobleaching experiments, in vitro permeabilized cell nuclear export assays, and glutathione S-transferase pull-down assays to investigate the export pathway used by TRalpha. We show that, in addition to shuttling in heterokaryons, TRalpha shuttles rapidly in an unfused monokaryon system as well. Furthermore, our data show that TRalpha directly interacts with calreticulin, and point to the intriguing possibility that TRalpha follows a cooperative export pathway in which both calreticulin and CRM1 play a role in facilitating efficient translocation of TRalpha from the nucleus to cytoplasm. PMID:18641393

  6. Identification and characterization of growth hormone receptors in snakehead fish (Ophiocephalus argus cantor) liver.

    PubMed

    Sun, X; Zhu, S; Chan, S S; Toresson, G; Cheng, C H

    1997-12-01

    The specific binding of 125I-labeled fish growth hormone (GH) to hepatic membranes prepared from several freshwater fish was assessed. A high level of growth hormone receptor (GHR) was detected on the hepatic membranes of the snakehead fish (Ophiocephalus argus Cantor). Scatchard analysis of the binding data showed a single class of high affinity binding site with a binding affinity (Ka) of 1.45 +/- 0.23 x 10(9) M-1 and a binding capacity (Bmax) of 198 +/- 57 fmol/mg protein. The binding was specific for fish GH and was saturable. In addition, the specific binding was temperature- and time-dependent, reaching a steady state after 16 hr of incubation at 25 degrees . The molecular weight of GHR as measured by Sephadex G-200 column chromatography and Western blot analysis using a monoclonal antibody (Mab263) against GHR was found to be 200-400 and 90-93 kDa, respectively. Two bands at 65 and 89 kDa were identified in ligand crosslinking studies of membrane receptors. A sensitive teleost GH radioreceptor assay (RRA) was developed, using recombinant fish GH and a membrane preparation from snakehead fish liver, capable of measuring bioactive GH in fish sera or other samples.

  7. Ghrelin and the growth hormone secretagogue receptor in growth and development.

    PubMed

    Chanoine, J-P; De Waele, K; Walia, P

    2009-04-01

    The pancreas is a major source of ghrelin in the perinatal period, whereas gastric production progressively increases after birth. Loss of function of the genes for ghrelin or for the constitutively activated growth hormone secretagogue receptor (GHSR) does not affect birth weight and early postnatal growth. However, ghrl(-/-) or ghsr(-/-) mice fed a high fat diet starting soon after weaning are resistant to diet-induced obesity, suggesting that ghrelin affects the maturation of the metabolic axes involved in energy balance. In addition, animal and human studies suggest that GHSR plays a physiological role in linear growth. In mice, absence of the GHSR gene is associated with lower insulin-like growth factor 1 concentrations and lower body mass in adult animals, independently of food intake. In humans, a mutation of the GHSR gene that impairs the constitutive activity of the receptor was found in two families with short stature. Administration of acylated ghrelin to rat pups directly does not affect weight gain. In contrast, administration of ghrelin to pregnant or lactating rats results in greater fetal weight and postnatal weight gain, respectively, suggesting that maternal ghrelin may stimulate perinatal growth. These data point toward a physiological role for ghrelin and GHSR in growth and/or in the maturation of hormonal systems involved in the regulation of energy balance.

  8. Thyroid Hormone Receptor α1 Follows a Cooperative CRM1/Calreticulin-mediated Nuclear Export Pathway*

    PubMed Central

    Grespin, Matthew E.; Bonamy, Ghislain M. C.; Roggero, Vincent R.; Cameron, Nicole G.; Adam, Lindsay E.; Atchison, Andrew P.; Fratto, Victoria M.; Allison, Lizabeth A.

    2008-01-01

    The thyroid hormone receptor α1 (TRα) exhibits a dual role as an activator or repressor of its target genes in response to thyroid hormone (T3). Previously, we have shown that TRα, formerly thought to reside solely in the nucleus bound to DNA, actually shuttles rapidly between the nucleus and cytoplasm. An important aspect of the shuttling activity of TRα is its ability to exit the nucleus through the nuclear pore complex. TRα export is not sensitive to treatment with the CRM1-specific inhibitor leptomycin B (LMB) in heterokaryon assays, suggesting a role for an export receptor other than CRM1. Here, we have used a combined approach of in vivo fluorescence recovery after photobleaching experiments, in vitro permeabilized cell nuclear export assays, and glutathione S-transferase pull-down assays to investigate the export pathway used by TRα. We show that, in addition to shuttling in heterokaryons, TRα shuttles rapidly in an unfused monokaryon system as well. Furthermore, our data show that TRα directly interacts with calreticulin, and point to the intriguing possibility that TRα follows a cooperative export pathway in which both calreticulin and CRM1 play a role in facilitating efficient translocation of TRα from the nucleus to cytoplasm. PMID:18641393

  9. Isolation of a thyroid hormone-responsive gene by immunoprecipitation of thyroid hormone receptor-DNA complexes.

    PubMed Central

    Bigler, J; Eisenman, R N

    1994-01-01

    Thyroid hormone (T3) receptor (TR) is a ligand-dependent transcription factor that acts through specific binding sites in the promoter region of target genes. In order to identify new genes that are regulated by T3, we used anti-TR antiserum to immunoprecipitate TR-DNA complexes from GH4 cell nuclei that had previously been treated with a restriction enzyme. Screening of the immunopurified, cloned DNA for TR binding sites by electrophoretic mobility shift assay yielded 53 positive clones. A subset of these clones was specifically immunoprecipitated with anti-TR antiserum and may therefore represent biologically significant binding sites. One of these clones, clone 122, was characterized in detail. It includes sequences highly related to the NICER long terminal repeat-like element and contains three TR binding sites as determined by DNase I footprinting. Two of the clone 122 TR binding sites are located upstream of the TATA box, and one is located downstream. The TR binding site downstream from the promoter was necessary and sufficient to confer T3-dependent regulation in transient transfection experiments. Expression of a reporter construct under the control of the clone 122 promoter region was activated by TR in the absence of ligand and returned to basal levels after T3 addition. Clone 122 sequences hybridize to at least two different mRNAs of approximately 6 and 10 kb from GH4 cells. The levels of both of these mRNAs increased upon removal of T3. Our studies suggest that specific immunoprecipitation of chromatin allows identification of binding sites and target genes for transcription factors. Images PMID:7935476

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

    PubMed Central

    Yardley, Denise A

    2016-01-01

    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. PMID:27217795

  11. Thyroid hormone receptor and IGF1/IGFR systems: possible relations in the human heart.

    PubMed

    Sabatino, Laura; Gliozheni, Enri; Molinaro, Sabrina; Bonotti, Alessandra; Azzolina, Sienne; Popoff, Georges; Carpi, Angelo; Iervasi, Giorgio

    2007-09-01

    Thyroid hormone (TH) and insulin growth factor 1 (IGF1) systems both play crucial roles in the regulation of cardiac remodeling and hypertrophy processes. The mediation of this regulation is attributed to specific thyroid hormone receptors (TRs) and to the IGF1 receptor (IGF1R). In humans, two TR genes are expressed in the heart, TRalpha and TRbeta. Each gene generates two isoforms: TRalpha1, TRalpha2 and TRbeta1, TRbeta2. The aim of the present work was to study the local thyroid hormone and IGF1 signaling in human myocardium through the evaluation of the gene expression of TRalpha1, TRalpha2, TRbeta1 and IGF1R among atrial and ventricular biopsies obtained from patients undergoing cardiac surgery. Moreover, we evaluated possible correlations between TR and IGF1/IGF1R systems. Eighteen clinically and biochemically euthyroid patients (aged 68.3+/-3.2years, mean+/-SEM) without overt heart failure (Ejection Fraction (EF), 46.4+/-2.8%; Left Ventricular End Diastolic Diameter (LVEDD), 54.3+/-1.2mm, mean+/-SEM; NYHA I-II) were enrolled in the study: 13 undergoing aorto-coronary bypass and 5 undergoing valve replacement (aortic/mitral valve). The examination of total RNA, using real time PCR (LightCycler Technology) confirmed the expression of specific mRNAs encoding TRalpha1, TRalpha2, TRbeta1 and both IGF1 and IGF1R. We found that the three TR genes are co-expressed in the human atrium and ventricle. The finding of a strong correlation among IGF1R and the three TR genes expressed in the atrium (p<0.001) and among the three TRs in the atrium (p<0.001) suggests the interesting possibility that the two systems, TRs and IGF1R could also be functionally associated. PMID:17560756

  12. Liver X receptor β: new player in the regulatory network of thyroid hormone and 'browning' of white fat.

    PubMed

    Miao, Yifei; Warner, Margaret; Gustafsson, Jan-Ke

    2016-01-01

    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 II diabetes. 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 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 thyrotropin releasing hormone positive neurons in the paraventricular area of the hypothalamus, and thus stimulated secretion of thyroid-stimulating hormone 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. One unexpected finding of our study is that LXRs are indispensable in the thyroid hormone negative feedback loop at the level of the hypothalamus. LXRs maintain expression of thyroid receptors in the brain and when they are inactivated there is no negative feedback of thyroid hormone in the hypothalamus. Together, our findings have uncovered the basis of increased energy expenditure in male LXR knock-out mice and provided support for targeting LXRs in treatment of obesity. PMID:27386163

  13. Fluorescence Techniques for Measuring Kinetics of Specific Binding of Hormone to Cell Surface Receptors.

    NASA Astrophysics Data System (ADS)

    Hellen, Edward Herbert

    This thesis presents theoretical calculations and technical advances relevant to total internal reflection/ fluorescence photobleaching recovery (tir/fpr), and results from experiments using tir/fpr to measure the dissociation rate constant of epidermal growth factor (egf) hormone interacting with its receptor molecule on A431 cells. The classical electromagnetic calculations describe fluorescence emission from fluorophores near an interface (possibly metal coated). It is well known that an interface alters the emission properties of nearby fluorophores. Most previous classical calculations model the fluorophore as a fixed-amplitude dipole oscillator. However, for fluorophores under steady illumination, a fixed-power dipole is more appropriate. This modification corresponds to normalizing the fixed-amplitude dipole's intensity by its total dissipated power. The results for the fixed-power model differ nontrivially from the fixed-amplitude model. The observation-angle -dependent intensity as a function of the fluorophore's orientation and distance from the surface is calculated. General expressions are derived for the emission power as observed through a circular-aperture collection system located on either side of the interface. A system for maintaining long-term focus of samples under high-magnification quantitative observation in an epi-illumination optical microscope is described. Focus -dependent changes in the backreflection of an off-axis HeNe laser generate negative feedback signals which drive a dc motor coupled to the fine-focus knob of the microscope. This system has several advantages: (1) it is compatible and nonobstructive with concurrent data acqusition of sample intensities; (2) it requires no alteration of the sample, stage, or objective; (3) it monitors the position of sample areas very near to those under observation; (4) it is inexpensive. The system can hold a glass coverslip sample to within 0.5 μm of its preset focus position. Prismless tir

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

    SciTech Connect

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

    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.

  15. Thyroid hormones modulate GABA(A) receptor-mediated currents in hippocampal neurons.

    PubMed

    Puia, G; Losi, G

    2011-06-01

    Thyroid hormones (THs) play a crucial role in the maturation and functioning of mammalian central nervous system. Thyroxine (T4) and 3, 3', 5-L-triiodothyronine (T3) are well known for their genomic effects, but recently attention has been focused on their non genomic actions as modulators of neuronal activity. In the present study we report that T4 and T3 reduce, in a non competitive manner, GABA-evoked currents in rat hippocampal cultures with IC₅₀s of 13±4μM and 12±3μM, respectively. The genomically inactive compound rev-T3 was also able to inhibit the currents elicited by GABA. Blocking PKC or PKA activity, chelating intracellular calcium, or antagonizing the integrin receptor αVβ3 with TETRAC did not affect THs modulation of GABA-evoked currents. THs affect also synaptic activity in hippocampal and cortical cultured neurons. T3 and T4 reduced to approximately 50% the amplitude and frequency of spontaneous inhibitory synaptic currents (sIPSCs), without altering their decay kinetic. Tonic currents evoked by low GABA concentrations were also reduced by T3 (40±5%, n=14), but not by T4. Similarly, T3 decreased currents elicited by low concentrations of THIP, a low affinity GABAA receptor agonist that preferentially activates extrasynaptic receptors, whereas T4 was ineffective. Thus, our data demonstrate that T3 and T4 selectively affect GABAergic phasic and tonic neurotransmission. Since THs concentrations can be regulated at the level of the synapses these data suggest that the network activity of the whole brain could be differently modulated depending on the relative amount of these two hormones. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. PMID:21215272

  16. E6-associated protein (E6-AP) is a dual function coactivator of steroid hormone receptors

    PubMed Central

    Ramamoorthy, Sivapriya; Nawaz, Zafar

    2008-01-01

    Steroid hormone receptors (SHR) belong to a large family of ligand-activated transcription factors that perform their biological functions by enhancing the transcription of specific target genes. The transactivation functions of SHRs are regulated by a specialized group of proteins called coactivators. The SHR coactivators represent a growing class of proteins with various enzymatic activities that serve to modify the chromatin to facilitate the transcription of SHR target genes. The ubiquitin-proteasome pathway enzymes have also been added to the growing list of enzymatic activities that are recruited to the SHR target gene promoters during transcription. One such ubiquitin-proteasome pathway enzyme to be identified and characterized as a SHR coactivator was E6-associated protein (E6-AP). E6-AP is a hect (homologous to E6-associated protein carboxy-terminal domain) domain containing E3 ubiquitin ligase that possesses two independent separable functions; a coactivation function and an ubiquitin-protein ligase activity. Being a component of the ubiquitin-proteasome pathway, it is postulated that E6-AP may orchestrate the dynamics of steroid hormone receptor-mediated transcription by regulating the degradation of the transcriptional complexes. E6-AP has also been shown to be involved in the regulation of various aspects of reproduction such as prostate and mammary gland development. Furthermore, it has been demonstrated that E6-AP expression is down-regulated in breast and prostate tumors and that the expression of E6-AP is inversely associated with that of estrogen and androgen receptors. This review summarizes our current knowledge about the structures, molecular mechanisms, spatiotemporal expression patterns and biological functions of E6-AP. PMID:18432313

  17. Identification of Thyroid Hormone Receptor Active Compounds Using a Quantitative High-Throughput Screening Platform

    PubMed Central

    Freitas, Jaime; Miller, Nicole; Mengeling, Brenda J.; Xia, Menghang; Huang, Ruili; Houck, Keith; Rietjens, Ivonne M.C.M.; Furlow, J. David; Murk, Albertinka J.

    2014-01-01

    To adapt the use of GH3.TRE-Luc reporter gene cell line for a quantitative high-throughput screening (qHTS) platform, we miniaturized the reporter gene assay to a 1536-well plate format. 1280 chemicals from the Library of Pharmacologically Active Compounds (LOPAC) and the National Toxicology Program (NTP) 1408 compound collection were analyzed to identify potential thyroid hormone receptor (TR) agonists and antagonists. Of the 2688 compounds tested, eight scored as potential TR agonists when the positive hit cut-off was defined at ≥10% efficacy, relative to maximal triiodothyronine (T3) induction, and with only one of those compounds reaching ≥20% efficacy. One common class of compounds positive in the agonist assays were retinoids such as all-trans retinoic acid, which are likely acting via the retinoid-X receptor, the heterodimer partner with the TR. Five potential TR antagonists were identified, including the antiallergy drug tranilast and the anxiolytic drug SB 205384 but also some cytotoxic compounds like 5-fluorouracil. None of the inactive compounds were structurally related to T3, nor had been reported elsewhere to be thyroid hormone disruptors, so false negatives were not detected. None of the low potency (>100µM) TR agonists resembled T3 or T4, thus these may not bind directly in the ligand-binding pocket of the receptor. For TR agonists, in the qHTS, a hit cut-off of ≥20% efficacy at 100 µM may avoid identification of positives with low or no physiological relevance. The miniaturized GH3.TRE-Luc assay offers a promising addition to the in vitro test battery for endocrine disruption, and given the low percentage of compounds testing positive, its high-throughput nature is an important advantage for future toxicological screening. PMID:24772387

  18. Identification of two functional guanylin receptors in eel: multiple hormone-receptor system for osmoregulation in fish intestine and kidney.

    PubMed

    Yuge, Shinya; Yamagami, Sayaka; Inoue, Koji; Suzuki, Norio; Takei, Yoshio

    2006-10-01

    Guanylyl cyclase C (GC-C) is a single transmembrane receptor for a family of intestinal hormones, guanylins. In the eel, we previously identified three guanylins, whose gene expression was enhanced in the intestine after transfer from fresh water to seawater. However, only limited information is available about the structure and function of their receptor(s). In the present study, we cloned full-length cDNAs encoding two isoforms of GC-C, named GC-C1 and GC-C2, from eel intestine. The predicted GC-C proteins consisted of extracellular ligand-binding domain, membrane-spanning domain, kinase-like domain and cyclase catalytic domain, in which GC-C-specific sequences were largely conserved. Phylogenetic analyses showed that the cloned membrane GCs are grouped with the GC-C of other vertebrates but not with GC-A and GC-B. However, eel GC-Cs appear to have undergone unique structural evolution compared with other GC-Cs. The three eel guanylins (guanylin, uroguanylin and renoguanylin), but not eel atrial natriuretic peptide, stimulated cGMP production dose-dependently in COS cells expressing either of the cloned cDNAs, providing functional support for assignment as eel guanylin receptors. The potency order for cGMP production was uroguanylin > guanylin > or = renoguanylin for GC-C1; guanylin > or = renoguanylin > uroguanylin for GC-C2. The distinctive ligand selectivity was consistent with the low homology (53%) of the extracellular domain of the two GC-Cs compared with that observed for other domains (74-90%). Both GC-C genes were expressed in the alimentary tract (esophagus, stomach and intestine) and kidney, and their expression was higher in the intestine of seawater-adapted eels than that of freshwater eels just as observed with the guanylin genes. However, the expression of the receptor genes was unchanged for 24h after transfer of eels from fresh water to seawater or vice versa, showing slower response of the receptors to salinity changes than their ligands

  19. The Activation Mechanism of Glycoprotein Hormone Receptors with Implications in the Cause and Therapy of Endocrine Diseases.

    PubMed

    Brüser, Antje; Schulz, Angela; Rothemund, Sven; Ricken, Albert; Calebiro, Davide; Kleinau, Gunnar; Schöneberg, Torsten

    2016-01-01

    Glycoprotein hormones (GPHs) are the main regulators of the pituitary-thyroid and pituitary-gonadal axes. Selective interaction between GPHs and their cognate G protein-coupled receptors ensure specificity in GPH signaling. The mechanisms of how these hormones activate glycoprotein hormone receptors (GPHRs) or how mutations and autoantibodies can alter receptor function were unclear. Based on the hypothesis that GPHRs contain an internal agonist, we systematically screened peptide libraries derived from the ectodomain for agonistic activity on the receptors. We show that a peptide (p10) derived from a conserved sequence in the C-terminal part of the extracellular N terminus can activate all GPHRs in vitro and in GPHR-expressing tissues. Inactivating mutations in this conserved region or in p10 can inhibit activation of the thyroid-stimulating hormone receptor by autoantibodies. Our data suggest an activation mechanism where, upon extracellular ligand binding, this intramolecular agonist isomerizes and induces structural changes in the 7-transmembrane helix domain, triggering G protein activation. This mechanism can explain the pathophysiology of activating autoantibodies and several mutations causing endocrine dysfunctions such as Graves disease and hypo- and hyperthyroidism. Our findings highlight an evolutionarily conserved activation mechanism of GPHRs and will further promote the development of specific ligands useful to treat Graves disease and other dysfunctions of GPHRs.

  20. Purification, characterization, and amino-terminal sequence of rat ovarian receptor for luteinizing hormone/human choriogonadotropin.

    PubMed

    Roche, P C; Ryan, R J

    1989-03-15

    The luteinizing hormone (LH)/human choriogonadotropin (hCG) receptor of rat ovary was solubilized with Lubrol PX in the presence of 20% glycerol and protease inhibitors, and purified by one-step affinity chromatography. Purified receptor had a specific hCG binding capacity of 4900 pmol/mg protein, and displayed a single class of high affinity binding sites (Ka = 6.20 X 10(9) M-1). An 11,200-fold purification over the starting crude homogenate was achieved. The purified LH/hCG receptor was identified by sodium dodecyl sulfate-gel electrophoresis and silver staining as a single protein of 92 kDa. The ability of the purified 92-kDa protein to specifically bind hormone was demonstrated by electroblotting onto Immobilon P membrane, incubation with 125I-labeled hCG, and autoradiography of the blot. In addition to a 92-kDa band, ligand blotting also yielded a 170-kDa band representing receptor dimer. Covalent cross-linking of hCG, with isotope in either the alpha- or beta-subunit, to membrane-bound receptor produced complexes that contained a single receptor component of approximately 92 kDa. The cross-linking studies indicated that both subunits interact with receptor and also suggested receptor dimer formation. Following sodium dodecyl sulfate-electrophoresis, purified receptor was electroblotted onto polyethylenimine-treated glass fiber filters for direct microsequencing in a gas-phase sequenator. Eleven cycles of sequence analysis yielded the unique sequence: NH2-Arg-Glu-Leu-Ser-Gly-Ser-Leu-XXX-Pro-Glu-Pro-COOH. These results indicate that the rat ovarian LH/hCG receptor is a protein of 92 kDa which can be easily purified in microgram amounts. This study also describes a relatively simple technique for electroblotting and microsequencing that should be applicable to other membrane-bound hormone receptors. PMID:2925659

  1. Application of photoshop-based image analysis to quantification of hormone receptor expression in breast cancer.

    PubMed

    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.

  2. A new variant in signal peptide of the human luteinizing hormone receptor (LHCGR) affects receptor biogenesis causing leydig cell hypoplasia.

    PubMed

    Vezzoli, Valeria; Duminuco, Paolo; Vottero, Alessandra; Kleinau, Gunnar; Schülein, Ralf; Minari, Roberta; Bassi, Ivan; Bernasconi, Sergio; Persani, Luca; Bonomi, Marco

    2015-11-01

    The human luteinizing hormone/chorionic gonadotropin receptor (LHCGR) plays a fundamental role in male and female reproduction. In males, loss-of-function mutations in LHCGR have been associated with distinct degrees of impairment in pre- and postnatal testosterone secretion resulting in a variable phenotypic spectrum, classified as Leydig cell hypoplasia (LCH) type 1 (complete LH resistance and disorder of sex differentiation) and type 2 (partial LH resistance with impaired masculinization and fertility). Here, we report the case of an adolescent who came to the pediatric endocrinologist at the age of 12 years old for micropenis and cryptorchidism. Testis biopsy showed profound LCH and absent germinal line elements (Sertoli-only syndrome). The sequence analysis of the LHCGR gene showed the presence of a compound heterozygosity, being one variation, c.1847C>A p.S616Y, already described in association to Hypergonadotropic Hypogonadism, and the other, c.29 C>T p.L10P, a new identified variant in the putative signal peptide (SP) of LHCGR. Functional and structural studies provide first evidence that LHCGR have a functional and cleavable SP required for receptor biogenesis. Moreover, we demonstrate the pathogenic role of the novel p.L10P allelic variant, which has to be considered a loss-of-function mutation significantly contributing, in compound heterozygosity with p.S616Y, to the LCH type 2 observed in our patient.

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

    PubMed

    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

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

    PubMed Central

    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. PMID:27006520

  5. Synthesis and bioassay of radiolabeled, chiral probes for juvenile hormone receptor study

    SciTech Connect

    Eng, W.

    1987-01-01

    Four different types of compounds were synthesized for the detailed study on interactions between insect juvenile hormone (JH) and the corresponding binding proteins, receptor proteins and catabolic enzymes: (1) High specific activity /sup 3/H-labeled, chiral alkyldiazoacetates with their skeletons approaching those of natural JH I and JH II were synthesized as photoaffinity labels for probing JH receptor proteins in Lepidoptera. Compared with epoxy farnesyl diazoacetate (EFDA), epoxy bishomofarnesyl diazoacetate (EBDA) and epoxy homofarnesyl diazoacetate (EHDA) have largely increased affinity to Manduca sexta JH binding proteins (JHBP) as demonstrated by gel electrophoresis. (2) Chiral JH I and JH II acids, as well as 12-hydroxy-JH I and JH II were synthesized. The hydroxy groups in these compounds provide tether points for attachment to proteins to serve as antigens with most of the recognition sites preserved to be used in JH radioimmunoassays. (3) The first radioiodine-labeled JH, (/sup 125/I)-12-iodo-JH I, was synthesized, both in no-carrier-added and carrier-added forms, as one of the probes for JH receptor study. (4) Four alkylthioltrifluoropropanones with skeletons approaching that of JH III and functional groups mimicking the JH epoxide moiety were synthesized as inhibitors for JH esterase (JHE).

  6. Estrogen receptor-β in the gonadotropin-releasing hormone neuron.

    PubMed

    Wolfe, Andrew; Wu, Sheng

    2012-01-01

    Estrogen regulation of gonadotropin-releasing hormone (GnRH) neuronal activity plays a crucial role in homeostatic regulation of the hypothalamic-pituitary-gonadal axis. Estrogen also coordinates a complex series of physiological changes culminating with a surge of gonadotropin secretion that triggers ovulation of a developed follicle from the ovary. The coordinated functions of estrogen ensure that the female will elaborate appropriate reproductive behaviors ultimately designed to deliver sperm to the oocyte and to provide a receptive uterine environment for the fertilized embryo. Although the effects of estrogen on GnRH neuronal function have long been proposed to be indirect due to the presumed lack of estrogen receptors in GnRH neurons, the identification of alternative estrogen signaling pathways, including estrogen receptor (ER)β and membrane ERs such as GPR30, has put the focus back on estrogen's effect at the level of the GnRH neuron itself. One candidate to mediate the effects of estrogen is the β isoform of the estrogen receptor. We review the evidence for a role for ERβ-mediated regulation of GnRH neuronal function.

  7. Hormonal regulation of prolactin receptors in male rat target tissues: the effect of hypothyroidism and adrenalectomy.

    PubMed

    Kharroubi, A T; Slaunwhite, W R

    1984-10-01

    The effects of hypothyroidism and adrenalectomy (ADX) on PRL receptors as well as the subcellular distribution of PRL-binding sites in adult male rat target tissues were investigated. In ventral prostate, kidney, and adrenal, PRL-binding activity was enriched in the 15,000 X g pellet (mitochondrial/Golgi fraction). The zona fasiculata/reticularis plus medulla of the adrenal had higher PRL-binding activity than the zona glomerulosa (plus capsule). Propylthiouracil-induced hypothyroidism significantly decreased PRL binding to kidney (65%) and testis (50%), and 16-h replacement with T4 restored PRL binding to control levels. T4 was, however, without effect on renal PRL binding in hypothyroid castrated rats, indicating that androgen may be required for this response. The increase in PRL binding to ventral prostate and adrenal due to hypothyroidism was not reversed within 16 h of T4 injection, whereas T3 injection decreased PRL binding to ventral prostate within 12 h. ADX increased PRL binding to rat testis (38%) and kidney (18%), and 5-day replacement with dexamethasone decreased PRL binding to levels lower than those in control rats. ADX had no effect, and dexamethasone treatment decreased (16-20%) PRL binding to ventral prostate and hCG binding to rat testis. The modulation of PRL receptors by hypothyroidism and ADX suggests that thyroid and adrenal hormones play a role in the regulation of PRL receptors. PMID:6090097

  8. Steroid hormone receptors and prostate cancer: role of structural dynamics in therapeutic targeting

    PubMed Central

    Kumar, Raj

    2016-01-01

    Steroid hormone receptors (SHRs) act in cell type- and gene-specific manner through interactions with coregulatory proteins to regulate numerous physiological and pathological processes at the level of gene regulation. Binding of steroid receptor modulator (SRM) ligand leads to allosteric changes in SHR to exert positive or negative effects on the expression of target genes. Due, in part, to the fact that current SRMs generally target ligand binding domain (LBD)/AF2 and neglect intrinsically disordered (ID) N-terminal domain (NTD)/AF1, clinically relevant SRMs lack selectivity and are also prone to the development of resistance over time. Therefore, to maximize the efficacy of SHR-based therapeutics, the possibility of developing unique modulators that act to control AF1 activity must be considered. Recent studies targeting androgen receptor's (AR's) ID AF1 domain for the castration-resistant prostate cancer has provided the possibility of therapeutically targeting ID NTD/AF1 surfaces by allosteric modulations to achieve desired effects. In this review article, we discuss how inter- and intra- molecular allosteric regulations controlled by AR's structural flexibility and dynamics particularly the ID NTD/AF1 is an emerging area of investigation, which could be exploited for drug development and therapeutic targeting of prostate cancer. PMID:27364545

  9. Thyroid hormone regulation of epidermal growth factor receptor levels in mouse mammary glands

    SciTech Connect

    Vonderhaar, B.K.; Tang, E.; Lyster, R.R.; Nascimento, M.C.

    1986-08-01

    The specific binding of iodinated epidermal growth factor ((/sup 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.

  10. Serotonergic receptor mechanisms underlying antidepressant-like action in the progesterone withdrawal model of hormonally induced depression in rats.

    PubMed

    Li, Yan; Raaby, Kasper F; Sánchez, Connie; Gulinello, Maria

    2013-11-01

    Hormonally induced mood disorders such as premenstrual dysphoric disorder (PMDD) are characterized by a range of physical and affective symptoms including anxiety, irritability, anhedonia, social withdrawal and depression. Studies demonstrated rodent models of progesterone withdrawal (PWD) have a high level of constructive and descriptive validity to model hormonally-induced mood disorders in women. Here we evaluate the effects of several classes of antidepressants in PWD female Long-Evans rats using the forced swim test (FST) as a measure of antidepressant activity. The study included fluoxetine, duloxetine, amitriptyline and an investigational multimodal antidepressant, vortioxetine (5-HT(3), 5-HT(7) and 5-HT(1D) receptor antagonist; 5-HT(1B) receptor partial agonist; 5-HT(1A) receptor agonist; inhibitor of the serotonin transporter (SERT)). After 14 days of administration, amitriptyline and vortioxetine significantly reduced immobility in the FST whereas fluoxetine and duloxetine were ineffective. After 3 injections over 48 h, neither fluoxetine nor duloxetine reduced immobility, whereas amitriptyline and vortioxetine significantly reduced FST immobility during PWD. When administered acutely during PWD, the 5-HT(1A) receptor agonist, flesinoxan, significantly reduced immobility, whereas the 5-HT(1A) receptor antagonist, WAY-100635, increased immobility. The 5-HT(3) receptor antagonist, ondansetron, significantly reduced immobility, whereas the 5-HT(3) receptor agonist, SR-57227, increased immobility. The 5-HT(7) receptor antagonist, SB-269970, was inactive, although the 5-HT(7) receptor agonist, AS-19, significantly increased PWD-induced immobility. None of the compounds investigated (ondansetron, flesinoxan and SB-269970) improved the effect of fluoxetine during PWD. These data indicate that modulation of specific 5-HT receptor subtypes is critical for manipulating FST immobility in this model of hormone-induced depression.

  11. International Union of Basic and Clinical Pharmacology. XCIII. The Parathyroid Hormone Receptors—Family B G Protein–Coupled Receptors

    PubMed Central

    Vilardaga, Jean-Pierre

    2015-01-01

    The type-1 parathyroid hormone receptor (PTHR1) is a family B G protein–coupled receptor (GPCR) that mediates the actions of two polypeptide ligands; parathyroid hormone (PTH), an endocrine hormone that regulates the levels of calcium and inorganic phosphate in the blood by acting on bone and kidney, and PTH-related protein (PTHrP), a paracrine-factor that regulates cell differentiation and proliferation programs in developing bone and other tissues. The type-2 parathyroid hormone receptor (PTHR2) binds a peptide ligand, called tuberoinfundibular peptide-39 (TIP39), and while the biologic role of the PTHR2/TIP39 system is not as defined as that of the PTHR1, it likely plays a role in the central nervous system as well as in spermatogenesis. Mechanisms of action at these receptors have been explored through a variety of pharmacological and biochemical approaches, and the data obtained support a basic “two-site” mode of ligand binding now thought to be used by each of the family B peptide hormone GPCRs. Recent crystallographic studies on the family B GPCRs are providing new insights that help to further refine the specifics of the overall receptor architecture and modes of ligand docking. One intriguing pharmacological finding for the PTHR1 is that it can form surprisingly stable complexes with certain PTH/PTHrP ligand analogs and thereby mediate markedly prolonged cell signaling responses that persist even when the bulk of the complexes are found in internalized vesicles. The PTHR1 thus appears to be able to activate the Gαs/cAMP pathway not only from the plasma membrane but also from the endosomal domain. The cumulative findings could have an impact on efforts to develop new drug therapies for the PTH receptors. PMID:25713287

  12. Human insulin analogues modified at the B26 site reveal a hormone conformation that is undetected in the receptor complex

    SciTech Connect

    Žáková, Lenka; Kletvíková, Emília; Lepšík, Martin; Collinsová, Michaela; Watson, Christopher J.; Turkenburg, Johan P.; Jiráček, Jiří; Brzozowski, Andrzej M.

    2014-10-01

    [AsnB26]- and [GlyB26]-insulin mutants attain a B26-turn like fold without assistance of chemical modifications. Their structures match the insulin receptor interface and expand the spectrum of insulin conformations. The structural characterization of the insulin–insulin receptor (IR) interaction still lacks the conformation of the crucial B21–B30 insulin region, which must be different from that in its storage forms to ensure effective receptor binding. Here, it is shown that insulin analogues modified by natural amino acids at the TyrB26 site can represent an active form of this hormone. In particular, [AsnB26]-insulin and [GlyB26]-insulin attain a B26-turn-like conformation that differs from that in all known structures of the native hormone. It also matches the receptor interface, avoiding substantial steric clashes. This indicates that insulin may attain a B26-turn-like conformation upon IR binding. Moreover, there is an unexpected, but significant, binding specificity of the AsnB26 mutant for predominantly the metabolic B isoform of the receptor. As it is correlated with the B26 bend of the B-chain of the hormone, the structures of AsnB26 analogues may provide the first structural insight into the structural origins of differential insulin signalling through insulin receptor A and B isoforms.

  13. The thyroid hormone nuclear receptor TRα1 controls the Notch signaling pathway and cell fate in murine intestine.

    PubMed

    Sirakov, Maria; Boussouar, Amina; Kress, Elsa; Frau, Carla; Lone, Imtiaz Nisar; Nadjar, Julien; Angelov, Dimitar; Plateroti, Michelina

    2015-08-15

    Thyroid hormones control various aspects of gut development and homeostasis. The best-known example is in gastrointestinal tract remodeling during amphibian metamorphosis. It is well documented that these hormones act via the TR nuclear receptors, which are hormone-modulated transcription factors. Several studies have shown that thyroid hormones regulate the expression of several genes in the Notch signaling pathway, indicating a possible means by which they participate in the control of gut physiology. However, the mechanisms and biological significance of this control have remained unexplored. Using multiple in vivo and in vitro approaches, we show that thyroid hormones positively regulate Notch activity through the TRα1 receptor. From a molecular point of view, TRα1 indirectly controls Notch1, Dll1, Dll4 and Hes1 expression but acts as a direct transcriptional regulator of the Jag1 gene by binding to a responsive element in the Jag1 promoter. Our findings show that the TRα1 nuclear receptor plays a key role in intestinal crypt progenitor/stem cell biology by controlling the Notch pathway and hence the balance between cell proliferation and cell differentiation.

  14. Molecular and biological interaction between major histocompatibility complex class I antigens and luteinizing hormone receptors or beta-adrenergic receptors triggers cellular response in mice.

    PubMed Central

    Solano, A R; Cremaschi, G; Sánchez, M L; Borda, E; Sterin-Borda, L; Podestá, E J

    1988-01-01

    Purified IgG from BALB/c mouse anti-C3H serum exerts positive inotropic and chronotropic effects in C3H mouse atria and induces testosterone synthesis in C3H mouse Leydig cells. The effect depends on IgG concentration and can be abolished by beta-adrenergic-receptor and luteinizing hormone-receptor antagonists. IgG interferes with the binding of dihydroalprenolol and luteinizing hormone. Monoclonal antibodies against major histocompatibility complex class I antigens were active on the Leydig cells of C3H and BALB/c mice. There was a parallelism between the effect of each individual monoclonal antibody with specificity for a particular haplotype and the response of the target cell from the strains carrying such haplotypes. These antibodies could precipitate the soluble luteinizing hormone-receptor complex. The results suggested that bound hormone triggers the association of major histocompatibility class I antigen with the receptor, thereby activating the respective target cells. PMID:2839829

  15. Parathyroid hormone receptor signalling in osterix-expressing mesenchymal progenitors is essential for tooth root formation.

    PubMed

    Ono, Wanida; Sakagami, Naoko; Nishimori, Shigeki; Ono, Noriaki; Kronenberg, Henry M

    2016-04-12

    Dental root formation is a dynamic process in which mesenchymal cells migrate toward the site of the future root, differentiate and secrete dentin and cementum. However, the identities of dental mesenchymal progenitors are largely unknown. Here we show that cells expressing osterix are mesenchymal progenitors contributing to all relevant cell types during morphogenesis. The majority of cells expressing parathyroid hormone-related peptide (PTHrP) are in the dental follicle and on the root surface, and deletion of its receptor (PPR) in these progenitors leads to failure of eruption and significantly truncated roots lacking periodontal ligaments. The PPR-deficient progenitors exhibit accelerated cementoblast differentiation with upregulation of nuclear factor I/C (Nfic). Deletion of histone deacetylase-4 (HDAC4) partially recapitulates the PPR deletion root phenotype. These findings indicate that PPR signalling in dental mesenchymal progenitors is essential for tooth root formation, underscoring importance of the PTHrP-PPR system during root morphogenesis and tooth eruption.

  16. The first intron of the human growth hormone gene contains a binding site for glucocorticoid receptor.

    PubMed Central

    Moore, D D; Marks, A R; Buckley, D I; Kapler, G; Payvar, F; Goodman, H M

    1985-01-01

    Glucocorticoid receptor (GCR) protein stimulates transcription from a variety of cellular genes. We show here that GCR partially purified from rat liver binds specifically to a site within the first intron of the human growth hormone (hGH) gene, approximately 100 base pairs downstream from the start of hGH transcription. GCR binding is selectively inhibited by methylation of two short, symmetrically arranged clusters of guanine residues within this site. A cloned synthetic 24-base-pair deoxyoligonucleotide containing the predicted GCR binding sequence interacts specifically with GCR. The hGH binding site shares sequence homology with a GCR binding site upstream from the human metallothionein II gene and a subset of GCR binding sites from mouse mammary tumor virus. All of these binding sites for this eukaryotic transcriptional regulatory protein show remarkable similarity in overall geometry to the binding sites for several prokaryotic transcriptional regulatory proteins. Images PMID:2983311

  17. Pharmacological Activation of Thyroid Hormone Receptors Elicits a Functional Conversion of White to Brown Fat.

    PubMed

    Lin, Jean Z; Martagón, Alexandro J; Cimini, Stephanie L; Gonzalez, Daniel D; Tinkey, David W; Biter, Amadeo; Baxter, John D; Webb, Paul; Gustafsson, Jan-Åke; Hartig, Sean M; Phillips, Kevin J

    2015-11-24

    The functional conversion of white adipose tissue (WAT) into a tissue with brown adipose tissue (BAT)-like activity, often referred to as "browning," represents an intriguing strategy for combating obesity and metabolic disease. We demonstrate that thyroid hormone receptor (TR) activation by a synthetic agonist markedly induces a program of adaptive thermogenesis in subcutaneous WAT that coincides with a restoration of cold tolerance to cold-intolerant mice. Distinct from most other browning agents, pharmacological TR activation dissociates the browning of WAT from activation of classical BAT. TR agonism also induces the browning of white adipocytes in vitro, indicating that TR-mediated browning is cell autonomous. These data establish TR agonists as a class of browning agents, implicate the TRs in the browning of WAT, and suggest a profound pharmacological potential of this action.

  18. [The correlations between polymorphism of growth hormone receptor gene and butcher traits in rabbit].

    PubMed

    Deng, Xiao-Song; Wan, Jie; Chen, Shi-Yi; Wang, Yan; Lai, Song-Jia; Jiang, Mei-Shan; Xu, Min

    2008-11-01

    Five rabbit populations (Belgian hare, Tianfu black rabbit, Great line of Zika rabbit, Harbin white rabbit, and California rabbit) were used to analyze the polymorphism of growth hormone receptor (GHR) gene by PCR-SSCP. Results indicated that there were two mutation sites (C705T and C810T) in the 5 populations. The least square analyses showed that the live weight, visceraste weight, and slaughter percentage of AA and MM genotypes were significantly lower than BB and NN genotypes (P<0.05). In contrast, the GHR polymorphism had no significant difference for least squares means of feed transformation efficiency (P>0.05). It suggested that GHR gene may be a candidate gene responsible for butcher trait in rabbit.

  19. Parathyroid hormone receptor signalling in osterix-expressing mesenchymal progenitors is essential for tooth root formation

    PubMed Central

    Ono, Wanida; Sakagami, Naoko; Nishimori, Shigeki; Ono, Noriaki; Kronenberg, Henry M.

    2016-01-01

    Dental root formation is a dynamic process in which mesenchymal cells migrate toward the site of the future root, differentiate and secrete dentin and cementum. However, the identities of dental mesenchymal progenitors are largely unknown. Here we show that cells expressing osterix are mesenchymal progenitors contributing to all relevant cell types during morphogenesis. The majority of cells expressing parathyroid hormone-related peptide (PTHrP) are in the dental follicle and on the root surface, and deletion of its receptor (PPR) in these progenitors leads to failure of eruption and significantly truncated roots lacking periodontal ligaments. The PPR-deficient progenitors exhibit accelerated cementoblast differentiation with upregulation of nuclear factor I/C (Nfic). Deletion of histone deacetylase-4 (HDAC4) partially recapitulates the PPR deletion root phenotype. These findings indicate that PPR signalling in dental mesenchymal progenitors is essential for tooth root formation, underscoring importance of the PTHrP–PPR system during root morphogenesis and tooth eruption. PMID:27068606

  20. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications.

    PubMed

    Kopchick, John J; List, Edward O; Kelder, Bruce; Gosney, Elahu S; Berryman, Darlene E

    2014-04-01

    The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant's preclinical and clinical trials, and provide data suggesting pegvisomant's therapeutic value in selected types of cancer. PMID:24035867

  1. Age- and sex-associated plasma proteomic changes in growth hormone receptor gene-disrupted mice.

    PubMed

    Ding, Juan; Berryman, Darlene E; Jara, Adam; Kopchick, John J

    2012-08-01

    Growth hormone receptor gene-disrupted (GHR-/-) mice are dwarf, insulin sensitive, and long lived despite being obese. In order to identify characteristics associated with their increased longevity, we studied age-related plasma proteomic changes in these mice. Male and female GHR-/- mice and their littermate controls were followed longitudinally at 8, 16, and 24 months of ages for plasma proteomic analysis. Relative to control littermates, GHR-/- mice had increased levels of apolipoprotein A-4 and retinol-binding protein-4 and decreased levels of apolipoprotein E, haptoglobin, and mannose-binding protein-C. Female GHR-/- mice showed decreased inflammatory cytokines including interleukin-1β and monocyte chemotactic protein-1. Additionally, sex differences were found in specific isoforms of apolipoprotein E, RBP-4, haptoglobin, albumin, and hemoglobin subunit beta. In conclusion, we find plasma proteomic changes in GHR-/- mice that favor a longer life span as well as sex differences indicative of an improved health span in female mice. PMID:22156438

  2. Kisspeptin directly stimulates gonadotropin-releasing hormone release via G protein-coupled receptor 54.

    PubMed

    Messager, Sophie; Chatzidaki, Emmanouella E; Ma, Dan; Hendrick, Alan G; Zahn, Dirk; Dixon, John; Thresher, Rosemary R; Malinge, Isabelle; Lomet, Didier; Carlton, Mark B L; Colledge, William H; Caraty, Alain; Aparicio, Samuel A J R

    2005-02-01

    We have recently described a molecular gatekeeper of the hypothalamic-pituitary-gonadal axis with the observation that G protein-coupled receptor 54 (GPR54) is required in mice and men for the pubertal onset of pulsatile luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion to occur. In the present study, we investigate the possible central mode of action of GPR54 and kisspeptin ligand. First, we show that GPR54 transcripts are colocalized with gonadotropin-releasing hormone (GnRH) neurons in the mouse hypothalamus, suggesting that kisspeptin, the GPR54 ligand, may act directly on these neurons. Next, we show that GnRH neurons seem anatomically normal in gpr54-/- mice, and that they show projections to the median eminence, which demonstrates that the hypogonadism in gpr54-/- mice is not due to an abnormal migration of GnRH neurons (as occurs with KAL1 mutations), but that it is more likely due to a lack of GnRH release or absence of GnRH neuron stimulation. We also show that levels of kisspeptin injected i.p., which stimulate robust LH and FSH release in wild-type mice, have no effect in gpr54-/- mice, and therefore that kisspeptin acts directly and uniquely by means of GPR54 signaling for this function. Finally, we demonstrate by direct measurement, that the central administration of kisspeptin intracerebroventricularly in sheep produces a dramatic release of GnRH into the cerebrospinal fluid, with a parallel rise in serum LH, demonstrating that a key action of kisspeptin on the hypothalamo-pituitary-gonadal axis occurs directly at the level of GnRH release. The localization and GnRH release effects of kisspeptin thus define GPR54 as a major control point in the reproductive axis and suggest kisspeptin to be a neurohormonal effector.

  3. Identification and Molecular Interaction Studies of Thyroid Hormone Receptor Disruptors among Household Dust Contaminants.

    PubMed

    Zhang, Jin; Li, Yaozong; Gupta, Arun A; Nam, Kwangho; Andersson, Patrik L

    2016-08-15

    Thyroid hormone disrupting chemicals (THDCs), often found abundantly in the environment, interfere with normal thyroid hormone signaling and induce physiological malfunctions, possibly by affecting thyroid hormone receptors (THRs). Indoor dust ingestion is a significant human exposure route of THDCs, raising serious concerns for human health. Here, we developed a virtual screening protocol based on an ensemble of X-ray crystallographic structures of human THRβ1 and the generalized Born solvation model to identify potential THDCs targeting the human THRβ1 isoform. The protocol was applied to virtually screen an in-house indoor dust contaminant inventory, yielding 31 dust contaminants as potential THRβ1 binders. Five predicted binders and one negative control were tested using isothermal titration calorimetry, of which four, i.e., 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether (BADGE-HCl-H2O), 2,2',4,4'-tetrahydroxybenzophenone (BP2), and 2,4-dichlorophenoxyacetic acid (2,4-D), were identified as THRβ1 binders with binding affinities ranging between 60 μM and 460 μM. Molecular dynamics (MD) simulations were employed to examine potential binding modes of these binders and provided a rationale for explaining their specific recognition by THRβ1. The combination of in vitro binding affinity measurements and MD simulations allowed identification of four new potential THR-targeting THDCs that have been found in household dust. We suggest using the developed structure-based virtual screening protocol to identify and prioritize testing of potential THDCs. PMID:27410513

  4. Thyroid hormone receptor inhibits hepatoma cell migration through transcriptional activation of Dickkopf 4

    SciTech Connect

    Chi, Hsiang-Cheng; Liao, Chen-Hsin; Huang, Ya-Hui; Wu, Sheng-Ming; Tsai, Chung-Ying; Liao, Chia-Jung; Tseng, Yi-Hsin; Lin, Yang-Hsiang; Chen, Cheng-Yi; Chung, I-Hsiao; Wu, Tzu-I; Chen, Wei-Jan; Lin, Kwang-Huei

    2013-09-13

    Highlights: •T{sub 3} affects DKK4 mRNA and protein expression in HepG2-TR cells. •Regulation of DKK4 by T{sub 3} is at transcriptional level. •DKK4 overexpression suppresses hepatoma cell metastasis. -- Abstract: Triiodothyronine (T{sub 3}) is a potent form of thyroid hormone mediates several physiological processes including cellular growth, development, and differentiation via binding to the nuclear thyroid hormone receptor (TR). Recent studies have demonstrated critical roles of T{sub 3}/TR in tumor progression. Moreover, long-term hypothyroidism appears to be associated with the incidence of human hepatocellular carcinoma (HCC), independent of other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein that antagonizes the canonical Wnt signaling pathway, is induced by T{sub 3} at both mRNA and protein levels in HCC cell lines. However, the mechanism underlying T{sub 3}-mediated regulation of DKK4 remains unknown. In the present study, the 5′ promoter region of DKK4 was serially deleted, and the reporter assay performed to localize the T{sub 3} response element (TRE). Consequently, we identified an atypical direct repeat TRE between nucleotides −1645 and −1629 conferring T{sub 3} responsiveness to the DKK4 gene. This region was further validated using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Stable DKK4 overexpression in SK-Hep-1 cells suppressed cell invasion and metastatic potential, both in vivo andin vitro, via reduction of matrix metalloproteinase-2 (MMP-2) expression. Our findings collectively suggest that DKK4 upregulated by T{sub 3}/TR antagonizes the Wnt signal pathway to suppress tumor cell progression, thus providing new insights into the molecular mechanism underlying thyroid hormone activity in HCC.

  5. Phosphorylation of the androgen receptor by PIM1 in hormone refractory prostate cancer.

    PubMed

    Ha, S; Iqbal, N J; Mita, P; Ruoff, R; Gerald, W L; Lepor, H; Taneja, S S; Lee, P; Melamed, J; Garabedian, M J; Logan, S K

    2013-08-22

    Integration of cellular signaling pathways with androgen receptor (AR) signaling can be achieved through phosphorylation of AR by cellular kinases. However, the kinases responsible for phosphorylating the AR at numerous sites and the functional consequences of AR phosphorylation are only partially understood. Bioinformatic analysis revealed AR serine 213 (S213) as a putative substrate for PIM1, a kinase overexpressed in prostate cancer. Therefore, phosphorylation of AR serine 213 by PIM1 was examined using a phosphorylation site-specific antibody. Wild-type PIM1, but not catalytically inactive PIM1, specifically phosphorylated AR but not an AR serine-to-alanine mutant (S213A). In vitro kinase assays confirmed that PIM1 can phosphorylate AR S213 in a ligand-independent manner and cell type-specific phosphorylation was observed in prostate cancer cell lines. Upon PIM1 overexpression, AR phosphorylation was observed in the absence of hormone and was further increased in the presence of hormone in LNCaP, LNCaP-abl and VCaP cells. Moreover, phosphorylation of AR was reduced in the presence of PIM kinase inhibitors. An examination of AR-mediated transcription showed that reporter gene activity was reduced in the presence of PIM1 and wild-type AR, but not S213A mutant AR. Androgen-mediated transcription of endogenous PSA, Nkx3.1 and IGFBP5 was also decreased in the presence of PIM1, whereas IL6, cyclin A1 and caveolin 2 were increased. Immunohistochemical analysis of prostate cancer tissue microarrays showed significant P-AR S213 expression that was associated with hormone refractory prostate cancers, likely identifying cells with catalytically active PIM1. In addition, prostate cancers expressing a high level of P-AR S213 were twice as likely to be from biochemically recurrent cancers. Thus, AR phosphorylation by PIM1 at S213 impacts gene transcription and is highly prevalent in aggressive prostate cancer.

  6. Androgen receptor repression of gonadotropin-releasing hormone gene transcription via enhancer 1.

    PubMed

    Brayman, Melissa J; Pepa, Patricia A; Mellon, Pamela L

    2012-11-01

    Gonadotropin-releasing hormone (GnRH) plays a major role in the hypothalamic-pituitary-gonadal (HPG) axis, and synthesis and secretion of GnRH are regulated by gonadal steroid hormones. Disruptions in androgen levels are involved in a number of reproductive defects, including hypogonadotropic hypogonadism and polycystic ovarian syndrome. Androgens down-regulate GnRH mRNA synthesis in vivo and in vitro via an androgen receptor (AR)-dependent mechanism. Methyltrienolone (R1881), a synthetic AR agonist, represses GnRH expression through multiple sites in the proximal promoter. In this study, we show AR also represses GnRH transcription via the major enhancer (GnRH-E1). A multimer of the -1800/-1766 region was repressed by R1881 treatment. Mutation of two bases, -1792 and -1791, resulted in decreased basal activity and a loss of AR-mediated repression. AR bound to the -1796/-1791 sequence in electrophoretic mobility shift assays, indicating a direct interaction with DNA or other transcription factors in this region. We conclude that AR repression of GnRH-E1 acts via multiple AR-responsive regions, including the site at -1792/-1791.

  7. Androgen receptor repression of gonadotropin-releasing hormone gene transcription via enhancer 1.

    PubMed

    Brayman, Melissa J; Pepa, Patricia A; Mellon, Pamela L

    2012-11-01

    Gonadotropin-releasing hormone (GnRH) plays a major role in the hypothalamic-pituitary-gonadal (HPG) axis, and synthesis and secretion of GnRH are regulated by gonadal steroid hormones. Disruptions in androgen levels are involved in a number of reproductive defects, including hypogonadotropic hypogonadism and polycystic ovarian syndrome. Androgens down-regulate GnRH mRNA synthesis in vivo and in vitro via an androgen receptor (AR)-dependent mechanism. Methyltrienolone (R1881), a synthetic AR agonist, represses GnRH expression through multiple sites in the proximal promoter. In this study, we show AR also represses GnRH transcription via the major enhancer (GnRH-E1). A multimer of the -1800/-1766 region was repressed by R1881 treatment. Mutation of two bases, -1792 and -1791, resulted in decreased basal activity and a loss of AR-mediated repression. AR bound to the -1796/-1791 sequence in electrophoretic mobility shift assays, indicating a direct interaction with DNA or other transcription factors in this region. We conclude that AR repression of GnRH-E1 acts via multiple AR-responsive regions, including the site at -1792/-1791. PMID:22877652

  8. Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

    PubMed Central

    Segers, F. H. I. D.; Berishvili, G.; Taborsky, B.

    2012-01-01

    Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid (Simochromis pleurospilus). The expression levels of one of them, the growth hormone receptor (GHR), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis. PMID:21752823

  9. Growth hormone activity in mitochondria depends on GH receptor Box 1 and involves caveolar pathway targeting

    SciTech Connect

    Perret-Vivancos, Cecile; Abbate, Aude; Ardail, Dominique; Raccurt, Mireille; Usson, Yves; Lobie, Peter E.; Morel, Gerard . E-mail: gerard.morel@univ-lyon1.fr

    2006-02-01

    Growth hormone (GH) binding to its receptor (GHR) initiates GH-dependent signal transduction and internalization pathways to generate the biological effects. The precise role and way of action of GH on mitochondrial function are not yet fully understood. We show here that GH can stimulate cellular oxygen consumption in CHO cells transfected with cDNA coding for the full-length GHR. By using different GHR cDNA constructs, we succeeded in determining the different parts of the GHR implicated in the mitochondrial response to GH. Polarography and two-photon excitation fluorescence microscopy analysis showed that the Box 1 of the GHR intracellular domain was required for an activation of the mitochondrial respiration in response to a GH exposure. However, confocal laser scanning microscopy demonstrated that cells lacking the GHR Box 1 could efficiently internalize the hormone. We demonstrated that internalization mediated either by clathrin-coated pits or by caveolae was able to regulate GH mitochondrial effect: these two pathways are both essential to obtain the GH stimulatory action on mitochondrial function. Moreover, electron microscopic and biochemical approaches allowed us to identify the caveolar pathway as essential for targeting GH and GHR to mitochondria.

  10. MEK5/ERK5 signaling suppresses estrogen receptor expression and promotes hormone-independent tumorigenesis.

    PubMed

    Antoon, James W; Martin, Elizabeth C; Lai, Rongye; Salvo, Virgilo A; Tang, Yan; Nitzchke, Ashley M; Elliott, Steven; Nam, Seung Yoon; Xiong, Wei; Rhodes, Lyndsay V; Collins-Burow, Bridgette; David, Odile; Wang, Guandi; Shan, Bin; Beckman, Barbara S; Nephew, Kenneth P; Burow, Matthew E

    2013-01-01

    Endocrine resistance and metastatic progression are primary causes of treatment failure in breast cancer. While mitogen activated protein kinases (MAPKs) are known to promote ligand-independent cell growth, the role of the MEK5-ERK5 pathway in the progression of clinical breast carcinoma remains poorly understood. Here, we demonstrated increased ERK5 activation in 30 of 39 (76.9%) clinical tumor samples, as well as across breast cancer cell systems. Overexpression of MEK5 in MCF-7 cells promoted both hormone-dependent and hormone-independent tumorigenesis in vitro and in vivo and conferred endocrine therapy resistance to previously sensitive breast cancer cells. Expression of MEK5 suppressed estrogen receptor (ER)α, but not ER-β protein levels, and abrogated downstream estrogen response element (ERE) transcriptional activity and ER-mediated gene transcription. Global gene expression changes associated with upregulation of MEK5 included increased activation of ER-α independent growth signaling pathways and promotion of epithelial-to-mesenchymal transition (EMT) markers. Taken together, our findings show that the MEK5-ERK5 pathway mediates progression to an ER(-), mesenchymal and endocrine therapy resistant phenotype. Given the need for new clinical therapeutic targets, our results demonstrate the therapeutic potential of targeting the MEK5-ERK5 pathway in breast cancer.

  11. Structural Basis for Hormone Recognition by the Human CRFR2[alpha] G Protein-coupled Receptor

    SciTech Connect

    Pal, Kuntal; Swaminathan, Kunchithapadam; Xu, H. Eric; Pioszak, Augen A.

    2012-05-09

    The mammalian corticotropin releasing factor (CRF)/urocortin (Ucn) peptide hormones include four structurally similar peptides, CRF, Ucn1, Ucn2, and Ucn3, that regulate stress responses, metabolism, and cardiovascular function by activating either of two related class B G protein-coupled receptors, CRFR1 and CRFR2. CRF and Ucn1 activate both receptors, whereas Ucn2 and Ucn3 are CRFR2-selective. The molecular basis for selectivity is unclear. Here, we show that the purified N-terminal extracellular domains (ECDs) of human CRFR1 and the CRFR2{alpha} isoform are sufficient to discriminate the peptides, and we present three crystal structures of the CRFR2{alpha} ECD bound to each of the Ucn peptides. The CRFR2{alpha} ECD forms the same fold observed for the CRFR1 and mouse CRFR2{beta} ECDs but contains a unique N-terminal {alpha}-helix formed by its pseudo signal peptide. The CRFR2{alpha} ECD peptide-binding site architecture is similar to that of CRFR1, and binding of the {alpha}-helical Ucn peptides closely resembles CRF binding to CRFR1. Comparing the electrostatic surface potentials of the ECDs suggests a charge compatibility mechanism for ligand discrimination involving a single amino acid difference in the receptors (CRFR1 Glu104/CRFR2{alpha} Pro-100) at a site proximate to peptide residue 35 (Arg in CRF/Ucn1, Ala in Ucn2/3). CRFR1 Glu-104 acts as a selectivity filter preventing Ucn2/3 binding because the nonpolar Ala-35 is incompatible with the negatively charged Glu-104. The structures explain the mechanisms of ligand recognition and discrimination and provide a molecular template for the rational design of therapeutic agents selectively targeting these receptors.

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

    SciTech Connect

    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.

  13. Thyroid hormone receptor binding to DNA and T3-dependent transcriptional activation are inhibited by uremic toxins

    PubMed Central

    Santos, Guilherme M; Pantoja, Carlos J; Costa e Silva, Aluízio; Rodrigues, Maria C; Ribeiro, Ralff C; Simeoni, Luiz A; Lomri, Noureddine; Neves, Francisco AR

    2005-01-01

    Background There is a substantial clinical overlap between chronic renal failure (CRF) and hypothyroidism, suggesting the presence of hypothyroidism in uremic patients. Although CRF patients have low T3 and T4 levels with normal thyroid-stimulating hormone (TSH), they show a higher prevalence of goiter and evidence for blunted tissue responsiveness to T3 action. However, there are no studies examining whether thyroid hormone receptors (TRs) play a role in thyroid hormone dysfunction in CRF patients. To evaluate the effects of an uremic environment on TR function, we investigated the effect of uremic plasma on TRβ1 binding to DNA as heterodimers with the retinoid X receptor alpha (RXRα) and on T3-dependent transcriptional activity. Results We demonstrated that uremic plasma collected prior to hemodialysis (Pre-HD) significantly reduced TRβ1-RXRα binding to DNA. Such inhibition was also observed with a vitamin D receptor (VDR) but not with a peroxisome proliferator-activated receptor gamma (PPARγ). A cell-based assay confirmed this effect where uremic pre-HD ultrafiltrate inhibited the transcriptional activation induced by T3 in U937 cells. In both cases, the inhibitory effects were reversed when the uremic plasma and the uremic ultrafiltrate were collected and used after hemodialysis (Post-HD). Conclusion These results suggest that dialyzable toxins in uremic plasma selectively block the binding of TRβ1-RXRα to DNA and impair T3 transcriptional activity. These findings may explain some features of hypothyroidism and thyroid hormone resistance observed in CRF patients. PMID:15807894

  14. Effect of gonadotropin-releasing hormone II receptor (GnRHR-II) knockdown on testosterone secretion in the boar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unlike the classical gonadotropin-releasing hormone (GnRH-I), the second mammalian GnRH isoform (GnRH-II; His5, Trp7, Tyr8) is a poor stimulator of gonadotropin secretion. In addition, GnRH-II is ubiquitously expressed, with transcript levels highest in tissues outside of the brain. A receptor speci...

  15. ICON 2013: practical consensus recommendations for hormone receptor-positive Her2-negative advanced or metastatic breastcancer.

    PubMed

    Parikh, P M; Gupta, S; Dawood, S; Rugo, H; Bhattacharyya, G S; Agarwal, A; Chacko, R; Sahoo, T P; Babu, G; Agarwal, S; Munshi, A; Goswami, C; Smruti, B K; Bondarde, S; Desai, C; Rajappa, S; Somani, N; Singh, M; Nimmagadda, R; Pavitran, K; Mehta, A; Parmar, V; Desai, S; Nair, R; Doval, D

    2014-01-01

    The management of hormone receptor-positive Her2-negative breast cancer patients with advanced or metastatic disease is a common problem in India and other countries in this region. This expert group used data from published literature, practical experience, and opinion of a large group of academic oncologists, to arrive at practical consensus recommendations for use by the community oncologists.

  16. Adult Body Size, Hormone Receptor Status, and Premenopausal Breast Cancer Risk in a Multiethnic Population

    PubMed Central

    John, Esther M.; Sangaramoorthy, Meera; Phipps, Amanda I.; Koo, Jocelyn; Horn-Ross, Pamela L.

    2011-01-01

    Large body size has been associated with a reduced risk of premenopausal breast cancer in non-Hispanic white women. Data on other racial/ethnic populations are limited. The authors examined the association between premenopausal breast cancer risk and adult body size in 672 cases and 808 controls aged ≥35 years from a population-based case-control study conducted in 1995–2004 in the San Francisco Bay Area (Hispanics: 375 cases, 483 controls; African Americans: 154 cases, 160 controls; non-Hispanic whites: 143 cases, 165 controls). Multivariate adjusted odds ratios and 95% confidence intervals were calculated using unconditional logistic regression. Height was associated with increased breast cancer risk (highest vs. lowest quartile: odds ratio = 1.77, 95% confidence interval: 1.23, 2.53; Ptrend < 0.01); the association did not vary by hormone receptor status or race/ethnicity. Body mass index (measured as weight (kg) divided by height (m) squared) was inversely associated with risk in all 3 racial/ethnic groups, but only for estrogen receptor– and progesterone receptor–positive tumors (body mass index ≥30 vs. <25: odds ratio = 0.42; 95% confidence interval: 0.29, 0.61). Other body size measures (current weight, body build, adult weight gain, young adult weight and body mass index, waist circumference, and waist-to-height ratio) were similarly inversely associated with risk of estrogen receptor– and progesterone receptor–positive breast cancer but not estrogen receptor– and progesterone receptor–negative disease. Despite racial/ethnic differences in body size, inverse associations were similar across the 3 racial/ethnic groups when stratified by hormone receptor status. PMID:21084558

  17. Modulation of ovarian function in female dogs immunized with bovine luteinizing hormone receptor.

    PubMed

    Saxena, B B; Clavio, A; Singh, M; Rathnam, P; Bukharovich, Y; Reimers, T; Saxena, A; Perkins, Scott

    2002-02-01

    Adult female dogs were immunized with 0.5 mg bovine luteinizing hormone receptor (LH-R) encapsulated in a silastic subdermal implant and subsequently with four intramuscular booster injections of 0.1 mg LH-R each. Circulating LH-R antibody was detected in the sera 3 weeks post-implant. The appearance of LH-R antibody was associated with a decline in the serum progesterone concentrations to a range of 0-0.5 ng/ml until day 365 in the immunized dogs in comparison with a range of 5-10 ng in the control animals, suggesting a lack of ovulation and corpus luteum function in immunized dogs. The immunized dogs did not show signs of 'standing heat' and failed to ovulate when induced by LH-RH challenge. Serum oestradiol levels, however, remained in the range of 30-40 pg/ml in both the immunized and the control dogs. With the decline in the antibody titres, the hormonal profile and vaginal cytology returned to a fertile state and the dogs exhibited signs of 'standing heat', as well as vaginal bleeding. Dogs immunized with LH-R did not show any serious metabolic, local or systemic adverse effects. The hypothalamic--pituitary gonadal axis remained intact as indicated by little difference in pituitary LH levels between control and immunized animals, and by the release of LH by LH-RH challenge. These studies demonstrate that active immunization of female dogs with LH-R could immunomodulate ovarian function to cause a reversible state of infertility. It may be postulated that, due to extensive interspecies homology, a recombinant LH receptor-based immunocontraceptive vaccine may also be effective in other vertebrates.

  18. Association of follicle stimulating hormone receptor promoter with ovarian response in IVF-ET patients

    PubMed Central

    Dan, Wang; Jing, Gao; Liangbin, Xia; Ting, Zhang; Ying, Zeng

    2015-01-01

    Background: Poor ovarian response phenomenon has been observed in some of the in vitro fertilization-embryo transfer patients. Some investigations found that follicle stimulating hormone receptor (FSHR) gene plays a role in the process, but no direct evidence shows the correlation between genotypes of FSHR and ovarian response. Objective: Exploring the molecular mechanism behind the mutation of FSHR promoter association with ovarian granulosa cells and poor ovarian response. Materials and Methods: This cross sectional study was performed using 158 women undergoing the controlled short program ovarian stimulation for IVF treatment. The 263 bp DNA fragments before the follicle stimulating hormone (FSH) receptor 5' initiation site were sequenced in the patients under IVF cycle, 70 of which had poor ovarian response and 88 showed normal ovarian responses. Results: With a mutation rate of 40%, 63 in 158 cases showed a 29th site G→A point mutation; among the mutated cases, the mutation rate of the poor ovarian responders was significantly higher than the normal group (60% versus 23.9%; χ2=21.450, p<0.001). Besides, the variability was also obvious in antral follicle count, and ovum pick-ups. The estradiol peak values and the number of mature eggs between the two groups had significant difference. However, there was no obvious variability (t=0.457, p=0.324) in the basic FSH values between the two groups (normal group, 7.2±2.3 U/L; mutation group, 7.1±2.0 U/L). Conclusion: The activity of FSHR promoter is significantly affected by the 29th site G→A mutation that will weaken promoter activity and result in poor response to FSH. PMID:26730247

  19. TBLR1 regulates the expression of nuclear hormone receptor co-repressors

    PubMed Central

    Zhang, Xin-Min; Chang, Qing; Zeng, Lin; Gu, Judy; Brown, Stuart; Basch, Ross S

    2006-01-01

    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 the co-repressors by TBLR1

  20. Identification of thyroid hormone receptor binding sites in developing mouse cerebellum

    PubMed Central

    2013-01-01

    Background Thyroid hormones play an essential role in early vertebrate development as well as other key processes. One of its modes of action is to bind to the thyroid hormone receptor (TR) which, in turn, binds to thyroid response elements (TREs) in promoter regions of target genes. The sequence motif for TREs remains largely undefined as does the precise chromosomal location of the TR binding sites. A chromatin immunoprecipitation on microarray (ChIP-chip) experiment was conducted using mouse cerebellum post natal day (PND) 4 and PND15 for the thyroid hormone receptor (TR) beta 1 to map its binding sites on over 5000 gene promoter regions. We have performed a detailed computational analysis of these data. Results By analysing a recent spike-in study, the optimal normalization and peak identification approaches were determined for our dataset. Application of these techniques led to the identification of 211 ChIP-chip peaks enriched for TR binding in cerebellum samples. ChIP-PCR validation of 25 peaks led to the identification of 16 true positive TREs. Following a detailed literature review to identify all known mouse TREs, a position weight matrix (PWM) was created representing the classic TRE sequence motif. Various classes of promoter regions were investigated for the presence of this PWM, including permuted sequences, randomly selected promoter sequences, and genes known to be regulated by TH. We found that while the occurrence of the TRE motif is strongly correlated with gene regulation by TH for some genes, other TH-regulated genes do not exhibit an increased density of TRE half-site motifs. Furthermore, we demonstrate that an increase in the rate of occurrence of the half-site motifs does not always indicate the specific location of the TRE within the promoter region. To account for the fact that TR often operates as a dimer, we introduce a novel dual-threshold PWM scanning approach for identifying TREs with a true positive rate of 0.73 and a false positive

  1. Structural rearrangements in the thyroid hormone receptor hinge domain and their putative role in the receptor function.

    PubMed

    Nascimento, Alessandro S; Dias, Sandra Martha Gomes; Nunes, Fábio M; Aparício, Ricardo; Ambrosio, Andre L B; Bleicher, Lucas; Figueira, Ana Carolina M; Santos, Maria Auxiliadora M; de Oliveira Neto, Mário; Fischer, Hannes; Togashi, Marie; Craievich, Aldo F; Garratt, Richard C; Baxter, John D; Webb, Paul; Polikarpov, Igor

    2006-07-14

    The thyroid hormone receptor (TR) D-domain links the ligand-binding domain (LBD, EF-domain) to the DNA-binding domain (DBD, C-domain), but its structure, and even its existence as a functional unit, are controversial. The D domain is poorly conserved throughout the nuclear receptor family and was originally proposed to comprise an unfolded hinge that facilitates rotation between the LBD and the DBD. Previous TR LBD structures, however, have indicated that the true unstructured region is three to six amino acid residues long and that the D-domain N terminus folds into a short amphipathic alpha-helix (H0) contiguous with the DBD and that the C terminus of the D-domain comprises H1 and H2 of the LBD. Here, we solve structures of TR-LBDs in different crystal forms and show that the N terminus of the TRalpha D-domain can adopt two structures; it can either fold into an amphipathic helix that resembles TRbeta H0 or form an unstructured loop. H0 formation requires contacts with the AF-2 coactivator-binding groove of the neighboring TR LBD, which binds H0 sequences that resemble coactivator LXXLL motifs. Structural analysis of a liganded TR LBD with small angle X-ray scattering (SAXS) suggests that AF-2/H0 interactions mediate dimerization of this protein in solution. We propose that the TR D-domain has the potential to form functionally important extensions of the DBD and LBD or unfold to permit TRs to adapt to different DNA response elements. We also show that mutations of the D domain LXXLL-like motif indeed selectively inhibit TR interactions with an inverted palindromic response element (F2) in vitro and TR activity at this response element in cell-based transfection experiments.

  2. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

    PubMed

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S; Je, Yeon Ho; Shin, Sang Woon

    2015-02-10

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides.

  3. Blocking Estrogen Signaling After the Hormone: Pyrimidine-Core Inhibitors of Estrogen Receptor-Coactivator Binding

    PubMed Central

    Parent, Alexander A.; Gunther, Jillian R.; Katzenellenbogen, John A.

    2009-01-01

    As an alternative approach to blocking estrogen action, we have developed small molecules that directly disrupt the key estrogen receptor (ER)/coactivator interaction necessary for gene activation. The more direct, protein-protein nature of this disruption might be effective even in hormone-refractory breast cancer. We have synthesized a pyrimidine-core library of moderate size, members of which act as α-helix mimics to block ERα/coactivator interaction. Structure- activity relationships have been explored with various C, N, O and S-substituents on the pyrimidine core. Time-resolved fluorescence resonance energy transfer and cell-based reporter gene assays show that the most active members inhibit the ERα/steroid receptor coactivator interaction with Ki’s in the low micromolar range. Through these studies, we have obtained a refined pharmacophore model for activity in this pyrimidine series. Furthermore, the favorable activities of several of these compounds support the feasibility that this coactivator binding inhibition mechanism for blocking estrogen action might provide a potential alternative approach to endocrine therapy. PMID:18785725

  4. Development of Follicle-Stimulating Hormone Receptor Binding Probes to Image Ovarian Xenografts

    PubMed Central

    Lee, Chung-Wein; Guo, Lili; Matei, Daniela; Stantz, Keith

    2015-01-01

    The Follicle-Stimulating Hormone Receptor (FSHR) is used as an imaging biomarker for the detection of ovarian cancer (OC). FSHR is highly expressed on ovarian tumors and involved with cancer development and metastatic signaling pathways. A decapeptide specific to the FSHR extracellular domain is synthesized and conjugated to fluorescent dyes to image OC cells in vitro and tumors xenograft model in vivo. The in vitro binding curve and the average number of FSHR per cell are obtained for OVCAR-3 cells by a high resolution flow cytometer. For the decapeptide, the measured EC50 was 160 μM and the average number of receptors per cell was 1.7 × 107. The decapeptide molecular imaging probe reached a maximum tumor to muscle ratio five hours after intravenous injection and a dose-dependent plateau after 24–48 hours. These results indicate the potential application of a small molecular weight imaging probe specific to ovarian cancer through binding to FSHR. Based on these results, multimeric constructs are being developed to optimize binding to ovarian cells and tumors. PMID:26779384

  5. QSAR study of selective ligands for the thyroid hormone receptor beta.

    PubMed

    Liu, Huanxiang; Gramatica, Paola

    2007-08-01

    In this paper, an accurate and reliable QSAR model of 87 selective ligands for the thyroid hormone receptor beta 1 (TRbeta1) was developed, based on theoretical molecular descriptors to predict the binding affinity of compounds with receptor. The structural characteristics of compounds were described wholly by a large amount of molecular structural descriptors calculated by DRAGON. Six most relevant structural descriptors to the studied activity were selected as the inputs of QSAR model by a robust optimization algorithm Genetic Algorithm. The built model was fully assessed by various validation methods, including internal and external validation, Y-randomization test, chemical applicability domain, and all the validations indicate that the QSAR model we proposed is robust and satisfactory. Thus, the built QSAR model can be used to fast and accurately predict the binding affinity of compounds (in the defined applicability domain) to TRbeta1. At the same time, the model proposed could also identify and provide some insight into what structural features are related to the biological activity of these compounds and provide some instruction for further designing the new selective ligands for TRbeta1 with high activity.

  6. Diofenolan induces male offspring production through binding to the juvenile hormone receptor in Daphnia magna.

    PubMed

    Abe, Ryoko; Toyota, Kenji; Miyakawa, Hitoshi; Watanabe, Haruna; Oka, Tomohiro; Miyagawa, Shinichi; Nishide, Hiroyo; Uchiyama, Ikuo; Tollefsen, Knut Erik; Iguchi, Taisen; Tatarazako, Norihisa

    2015-02-01

    Juvenile hormone (JH) and JH agonists have been reported to induce male offspring production in various daphnid species including Daphnia magna. We recently established a short-term in vivo screening assay to detect chemicals having male offspring induction activity in adult D. magna. Diofenolan has been developed as a JH agonist for insect pest control, but its male offspring induction activity in daphnids has not been investigated yet. In this study, we found that the insect growth regulator (IGR) diofenolan exhibited a potent male offspring induction activity at low ng/L to μg/L concentrations, as demonstrated by the short-term in vivo screening assay and the recently developed TG211 ANNEX 7 test protocol. A two-hybrid assay performed using the D. magna JH receptor confirmed that diofenolan had a strong JH activity. Global whole body transcriptome analysis of D. magna exposed to 10 ng/L diofenolan showed an up-regulation of JH-responsive genes and modulation of several genes involved in the ecdysone receptor signaling pathway. These results clearly demonstrate that diofenolan has strong JH activity and male offspring induction activity, and that a combination of modified standardized regulatory testing protocols and rapid in vitro and in vivo screening assays are able to identify potential endocrine disruptors in D. magna. The observation that diofenolan modulates multiple endocrine signaling pathways in D. magna suggests that further investigation of potential interference with growth, development and reproduction is warranted.

  7. The Glu727 Allele of Thyroid Stimulating Hormone Receptor Gene is Associated with Osteoporosis

    PubMed Central

    Liu, Ren-De; Chen, Rui-Xiong; Li, Wen-Rui; Huang, Yu-Liang; Li, Wen-Hu; Cai, Guang-Rong; Zhang, Heng

    2012-01-01

    Background: Published data indicate that thyroid stimulating hormone receptor (TSHR) activities are associated with osteoporosis in some patients. Aim: This study aimed to elucidate whether a given polymorphism of the TSHR gene is associated with osteoporosis. Materials and Methods: One hundred and fifty subjects with osteoporosis were recruited in this study. The diagnosis of osteoporosis was performed with quantitative ultrasound system. The TSHR gene polymorphism was examined by polymerase chain reaction–restriction fragment length polymorphism. Results: The results showed a nucleotide substitution in the first position of codon 36 of the TSHR gene. The nucleotide substitution was from G to C, leading to a 36D → 36H change (D36H) in the predicted amino acid sequence of the receptor. The change did not show significance between healthy subjects and patients with osteoporosis (P > 0.05). On the other hand, we identified another single nucleotide polymorphism that is a C-to-G substitution at codon 727 (GAC to GAG); its frequency was significantly higher in patients with osteoporosis than that in healthy subjects. Using logistic regression analysis, significant correlation was revealed between the genotype D727E and the serum levels of TSH, or the quantitative ultrasound value of the calcaneal bone. Conclusions: The present study suggests that the genotype D727E of the TSHR, but not the genotype D36H, may be a genetic risk factor for osteoporosis. PMID:22866266

  8. Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors

    PubMed Central

    Culhane, Kelly J.; Liu, Yuting; Cai, Yingying; Yan, Elsa C. Y.

    2015-01-01

    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. PMID:26594176

  9. Research Resource: Identification of Novel Coregulators Specific for Thyroid Hormone Receptor-β2

    PubMed Central

    Hahm, Johnnie B.

    2013-01-01

    Thyroid hormone receptors (TRs) are expressed as a series of interrelated isoforms that perform distinct biological roles. The TRβ2 isoform is found predominantly in the hypothalamus, pituitary, retina, and cochlea and displays unique transcriptional properties relative to the other TR isoforms. To more fully understand the isoform-specific biological and molecular properties of TRβ2, we have identified a series of previously unrecognized proteins that selectively interact with TRβ2 compared with the more widely expressed TRβ1. Several of these proteins preferentially enhance the transcriptional activity of TRβ2 when coexpressed in cells and are likely to represent novel, isoform-specific coactivators. Additional proteins were also identified in our screen that bind equally to TRβ1 and TRβ2 and may function as isoform-independent auxiliary proteins for these and/or other nuclear receptors. We propose that a combination of isoform-specific recruitment and tissue-specific expression of these newly identified coregulator candidates serves to customize TR function for different biological purposes in different cell types. PMID:23558175

  10. Spinal cord thyrotropin releasing hormone receptors of morphine tolerant-dependent and abstinent rats

    SciTech Connect

    Rahmani, N.H.; Gulati, A.; Bhargava, H.N. )

    1990-07-01

    The effect of chronic administration of morphine and its withdrawal on the binding of 3H-(3-MeHis2)thyrotropin releasing hormone (3H-MeTRH) to membranes of the spinal cord of the rat was determined. Male Sprague-Dawley rats were implanted with either 6 placebo or 6 morphine pellets (each containing 75-mg morphine base) during a 7-day period. Two sets of animals were used. In one, the pellets were left intact at the time of sacrificing (tolerant-dependent) and in the other, the pellets were removed 16 hours prior to sacrificing (abstinent rats). In placebo-pellet-implanted rats, 3H-MeTRH bound to the spinal cord membranes at a single high affinity binding site with a Bmax of 21.3 +/- 1.6 fmol/mg protein, and an apparent dissociation constant Kd of 4.7 +/- 0.8 nM. In morphine tolerant-dependent or abstinent rats, the binding constants of 3H-MeTRH to spinal cord membranes were unaffected. Previous studies from this laboratory indicate that TRH can inhibit morphine tolerance-dependence and abstinence processes without modifying brain TRH receptors. Together with the present results, it appears that the inhibitory effect of TRH on morphine tolerance-dependence and abstinence is probably not mediated via central TRH receptors but may be due to its interaction with other neurotransmitter systems.

  11. Expression of female sex hormone receptors in human middle-ear cholesteatomas.

    PubMed

    Raynov, Alexander Markov; Choung, Yun-Hoon; Moon, Sung-Kyun; Park, Keehyun

    2005-12-01

    The purpose of this study was to establish the eventual presence of progesterone receptor (PGR) and oestrogen receptor (EGR) in human middle-ear cholesteatoma (MECh) tissues and to compare their expression between male and female patients. An immunohistochemical technique was employed for detection of PGR- and EGR-specific immunoreactivity in MECh samples using formalin-fixed paraffin-embedded tissue sections. The positive results were verified with reverse transcriptase polymerase chain reaction (RT-PCR). The morphological study revealed stable expression of PGR in suprabasal layers of all cholesteatoma samples. Weaker immunoreactivity for PGR was demonstrated in external auditory canal skin (EACS) samples in comparison with MECh, while PGR-specific staining was not observed in retroauricular skin (RAS) samples. EGR was detected only at mRNA levels. Stronger expression of EGR PCR products was disclosed in female cholesteatoma samples, while PGR mRNA was predominantly detected in male cholesteatoma specimens. Our preliminary experimental results give us ground to assume that female sex hormones may stimulate proliferation and affect differentiation of MECh keratinocytes.

  12. Antagonist of GH-releasing hormone receptors alleviates experimental ocular inflammation

    PubMed Central

    Qin, Yong Jie; Chan, Sun On; Chong, Kelvin Kam Lung; Li, Benjamin Fuk Loi; Ng, Tsz Kin; Yip, Yolanda Wong Ying; Chen, Haoyu; Zhang, Mingzhi; Block, Norman L.; Cheung, Herman S.; Schally, Andrew V.; Pang, Chi Pui

    2014-01-01

    Disruptions in immunity and occurrence of inflammation cause many eye diseases. The growth hormone-releasing hormone–growth hormone–insulin-like growth factor-1 (GHRH–GH–IGF1) axis exerts regulatory effects on the immune system. Its involvement in ocular inflammation remains to be investigated. Here we studied this signaling in endotoxin-induced uveitis (EIU) generated by LPS. The increase in GHRH receptor (GHRH-R) protein levels was parallel to the increase in mRNA levels of pituitary-specific transcription factor-1, GHRH-R splice variant 1, GHRH, and GH following LPS insult. Elevation of GHRH-R and GH receptor was localized on the epithelium of the iris and ciliary body, and GHRH-R was confined to the infiltrating macrophages and leukocytes in aqueous humor but not to those in stroma. Treatment with GHRH-R antagonist decreased LPS-stimulated surges of GH and IGF1 in aqueous humor and alleviated inflammation by reducing the infiltration of macrophages and leukocytes and the production of TNF-α, IL-1β, and monocyte chemotactic protein-1. Our results indicate that inflammation in the iris and ciliary body involves the activation of GHRH signaling, which affects the recruitment of immune cells and the production of proinflammatory mediators that contribute to EIU pathogenesis. Moreover, the results suggest that GHRH-R antagonists are potential therapeutic agents for the treatment of acute ocular inflammation. PMID:25489106

  13. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

    PubMed

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S; Je, Yeon Ho; Shin, Sang Woon

    2015-02-10

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides. PMID:25624480

  14. Alpha-melanocyte-stimulating hormone down-regulates CXC receptors through activation of neutrophil elastase.

    PubMed

    Manna, Sunil K; Sarkar, Abira; Sreenivasan, Yashin

    2006-03-01

    Considering the role of interleukin-8 (IL-8) in a large number of acute and chronic inflammatory diseases, the regulation of IL-8-mediated biological responses is important. Alpha-melanocyte-stimulating hormone (alpha-MSH), a tridecapeptide, inhibits most forms of inflammation by an unknown mechanism. In the present study, we have found that alpha-MSH interacts predominantly with melanocortin-1 receptors and inhibits several IL-8-induced biological responses in macrophages and neutrophils. It down-regulated receptors for IL-8 but not for TNF, IL-4, IL-13 or TNF-related apoptosis-inducing ligand (TRAIL) in neutrophils. It down-regulated CXCR type 1 and 2 but not mRNA levels. alpha-MSH did not inhibit IL-8 binding in purified cell membrane or affinity-purified CXCR. IL-8 or anti-CXCR Ab protected against alpha-MSH-mediated inhibition of IL-8 binding. The level of neutrophil elastase, a specific serine protease, but not cathepsin G or proteinase 3 increased in alpha-MSH-treated cells, and restoration of CXCR by specific neutrophil elastase or serine protease inhibitors indicates the involvement of elastase in alpha-MSH-induced down-regulation of CXCR. These studies suggest that alpha-MSH inhibits IL-8-mediated biological responses by down-regulating CXCR through induction of serine protease and that alpha-MSH acts as a potent immunomodulator in neutrophil-driven inflammatory distress. PMID:16479540

  15. Primary cilia enhance kisspeptin receptor signaling on gonadotropin-releasing hormone neurons

    PubMed Central

    Koemeter-Cox, Andrew I.; Sherwood, Thomas W.; Green, Jill A.; Steiner, Robert A.; Berbari, Nicolas F.; Yoder, Bradley K.; Kauffman, Alexander S.; Monsma, Paula C.; Brown, Anthony; Askwith, Candice C.; Mykytyn, Kirk

    2014-01-01

    Most central neurons in the mammalian brain possess an appendage called a primary cilium that projects from the soma into the extracellular space. The importance of these organelles is highlighted by the fact that primary cilia dysfunction is associated with numerous neuropathologies, including hyperphagia-induced obesity, hypogonadism, and learning and memory deficits. Neuronal cilia are enriched for signaling molecules, including certain G protein-coupled receptors (GPCRs), suggesting that neuronal cilia sense and respond to neuromodulators in the extracellular space. However, the impact of cilia on signaling to central neurons has never been demonstrated. Here, we show that the kisspeptin receptor (Kiss1r), a GPCR that is activated by kisspeptin to regulate the onset of puberty and adult reproductive function, is enriched in cilia projecting from mouse gonadotropin-releasing hormone (GnRH) neurons. Interestingly, GnRH neurons in adult animals are multiciliated and the percentage of GnRH neurons possessing multiple Kiss1r-positive cilia increases during postnatal development in a progression that correlates with sexual maturation. Remarkably, disruption of cilia selectively on GnRH neurons leads to a significant reduction in kisspeptin-mediated GnRH neuronal activity. To our knowledge, this result is the first demonstration of cilia disruption affecting central neuronal activity and highlights the importance of cilia for proper GPCR signaling. PMID:24982149

  16. Magnesium modulates parathyroid hormone secretion and upregulates parathyroid receptor expression at moderately low calcium concentration

    PubMed Central

    Rodríguez-Ortiz, Maria E.; Canalejo, Antonio; Herencia, Carmen; Martínez-Moreno, Julio M.; Peralta-Ramírez, Alan; Perez-Martinez, Pablo; Navarro-González, Juan F.; Rodríguez, Mariano; Peter, Mirjam; Gundlach, Kristina; Steppan, Sonja; Passlick-Deetjen, Jutta; Muñoz-Castañeda, Juan R.; Almaden, Yolanda

    2014-01-01

    Background The interest on magnesium (Mg) has grown since clinical studies have shown the efficacy of Mg-containing phosphate binders. However, some concern has arisen for the potential effect of increased serum Mg on parathyroid hormone (PTH) secretion. Our objective was to evaluate the direct effect of Mg in the regulation of the parathyroid function; specifically, PTH secretion and the expression of parathyroid cell receptors: CaR, the vitamin D receptor (VDR) and FGFR1/Klotho. Methods The work was performed in vitro by incubating intact rat parathyroid glands in different calcium (Ca) and Mg concentrations. Results Increasing Mg concentrations from 0.5 to 2 mM produced a left shift of PTH–Ca curves. With Mg 5 mM, the secretory response was practically abolished. Mg was able to reduce PTH only if parathyroid glands were exposed to moderately low Ca concentrations; with normal–high Ca concentrations, the effect of Mg on PTH inhibition was minor or absent. After 6-h incubation at a Ca concentration of 1.0 mM, the expression of parathyroid CaR, VDR, FGFR1 and Klotho (at mRNA and protein levels) was increased with a Mg concentration of 2.0 when compared with 0.5 mM. Conclusions Mg reduces PTH secretion mainly when a moderate low calcium concentration is present; Mg also modulates parathyroid glands function through upregulation of the key cellular receptors CaR, VDR and FGF23/Klotho system. PMID:24103811

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

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26504234

  19. Digestive physiology of the pig symposium: G protein-coupled receptors in nutrient chemosensation and gastrointestinal hormone secretion.

    PubMed

    Liou, A P

    2013-05-01

    The gastrointestinal tract is a highly effective and efficient organ system that digests and absorbs nutrients, contributes to the regulation of glucose homeostasis, and signals postprandial satiety. A network of enteroendocrine cells orchestrates these events through the release of neuropeptide hormones secreted in response to the specific nutrient components within the intraluminal milieu. Nutrient chemosensing by these cells is mediated by cell membrane proteins that have been localized to hormone-producing cells. However, functional studies of the nutrient detection abilities of the endocrine cell population have been limited due to its rare and singly distributed cell type. Recent technological advances have enabled investigations with primary endocrine cells that promise to enhance our current understanding of enteroendocrine cell biology. This review focuses on a particular subset of chemosensing receptors, the G protein-coupled receptors (GPCR), that have been identified as putative nutrient sensors of the major macronutrients, lipids, proteins, and carbohydrates by enteroendocrine cells. The contributions of these receptors in directly activating and stimulating hormone secretion in several subsets of enteroendocrine cells will be discussed, based on evidence gathered by functional studies in animal models, in vitro studies in endocrine cell lines, and newly described findings in primary endocrine cells. Key insights in chemosensory detection and hormone secretion from enteroendocrine cells may help further the studies in larger animal models and guide the formulation of feed or supplements to influence the gastrointestinal signals regulating optimal food intake, absorptive capacity, and growth. PMID:23230119

  20. A new point mutation (C446R) in the thyroid hormone receptor-{beta} gene of a family with resistance to thyroid hormone

    SciTech Connect

    Weiss, R.E.; Chyna, B.; Hayashi, Yoshitaka; Sunthornthepvarakul, T.; Refetoff, S.; Duell, P.B.

    1994-05-01

    Resistance to thyroid hormone (RTH) is a condition of impaired end-organ responsiveness to thyroid hormone characterized by goiter and elevated thyroid hormone levels with an appropriately normal TSH. RTH has been associated with mutations in the thyroid hormone receptor-{beta} (TR{beta}) gene. The authors report studies carried out in 21 members of a family (F119), 12 of whom exhibited the RTH phenotype. A point mutation was detected in the T{sub 3}-binding domain of the TR{beta} gene. It resulted in replacement of the normal cysteine-446 with an arginine (C446R) that has not been previously reported. The clinical characteristics of this family are similar to those reported in other families with RTH, namely goiter, tachycardia, and learning disabilities. Thyroid function tests are also typical of other subjects with RTH. The mean values ({+-}SD) in untreated affected subjects compared to those in unaffected family members were: free T{sub 4} index, 250 {+-} 21 vs. 108 {+-} 13; total T{sub 3}, 4.3 {+-} 0.4 vs. 2.4 {+-} 0.4 nmol/L; and TSH, 4.5 {+-} 1.1 vs. 2.4 {+-} 1.1 mU/L. DNA samples from 18 family members were screened for the TR{beta} mutation, which results in the loss of a BsmI restriction site, and each of the 11 subjects with abnormal thyroid function tests were heterozygous for the mutant allele. The mutant TR{beta} expressed in Cos-I cells did not bind T{sub 3} (K{sub a} of C446R/wild-type, <0.05). T{sub 3} at a concentration up to 100 nmol/L failed to enhance the transactivation of a reporter gene, and the mutant receptor inhibited the T{sub 3}-mediated transcriptional activation of the wild-type TR{beta}. 17 refs., 3 figs., 1 tab.

  1. HMG-CoAR expression in male breast cancer: relationship with hormone receptors, Hippo transducers and survival outcomes

    PubMed Central

    Di Benedetto, Anna; Mottolese, Marcella; Sperati, Francesca; Ercolani, Cristiana; Di Lauro, Luigi; Pizzuti, Laura; Vici, Patrizia; Terrenato, Irene; Shaaban, Abeer M.; Sundara-Rajan, Sreekumar; Humphries, Matthew P.; Barba, Maddalena; Speirs, Valerie; De Maria, Ruggero; Maugeri-Saccà, Marcello

    2016-01-01

    Male breast cancer (MBC) is a rare hormone-driven disease often associated with obesity. HMG-CoAR is the central enzyme of the mevalonate pathway, a molecular route deputed to produce cholesterol and steroid-based hormones. HMG-CoAR regulates the oncogenic Hippo transducers TAZ/YAP whose expression was previously associated with shorter survival in MBC. 225 MBC samples were immunostained for HMG-CoAR and 124 were considered eligible for exploring its relationship with hormone receptors (ER, PgR, AR), Hippo transducers and survival outcomes. HMG-CoAR was positively associated with the expression of hormone receptors (ER, PgR, AR) and Hippo transducers. Overall survival was longer in patients with HMG-CoAR-positive tumors compared with their negative counterparts (p = 0.031). Five- and 10-year survival outcomes were better in patients whose tumors expressed HMG-CoAR (p = 0.044 and p = 0.043). Uni- and multivariate analyses for 10-year survival suggested that HMG-CoAR expression is a protective factor (HR 0.50, 95% CI: 0.25–0.99, p = 0.048 and HR 0.53, 95% CI: 0.26–1.07, p = 0.078). Results were confirmed in a sensitivity analysis by excluding uncommon histotypes (multivariate Cox: HR 0.45, 95% CI: 0.21–0.97, p = 0.043). A positive relationship emerged between HMG-CoAR, hormone receptors and TAZ/YAP, suggesting a connection between the mevalonate pathway, the hormonal milieu and Hippo in MBC. Moreover, HMG-CoAR expression may be a favorable prognostic indicator. PMID:27713571

  2. Effects of female pheromones on gonadotropin-releasing hormone gene expression and luteinizing hormone release in male wild-type and oestrogen receptor-alpha knockout mice.

    PubMed

    Gore, A C; Wersinger, S R; Rissman, E F

    2000-12-01

    Pheromones are an important class of environmental cues that affect the hypothalamic-pituitary-gonadal axis in a variety of vertebrate species, including humans. When male mice contact female-soiled bedding, or urine, they display a reflexive luteinizing hormone (LH) surge within 30 min. Aside from the requirement that males have gonads to show this response, the physiological mechanisms that underlie this pituitary response are unknown. In this experiment, we asked if female pheromones acted at the level of gonadotropin-releasing hormone (GnRH) gene expression to affect this hormone response. In addition, we also examined the contribution of one of the oestrogen receptors (ERalpha) by studying this neuroendocrine reflex in wild-type and oestrogen receptor-alpha knockout (ERalphaKO) males. Both ERalphaKO and wild-type males showed the expected LH surge, 45 and 90 min after contact with female pheromones. Males housed in clean bedding or bedding soiled by another adult male did not display the LH elevation. Interestingly, this dramatic change in LH concentrations was not accompanied by any alterations in GnRH mRNA expression or levels of primary transcript in the preoptic area-anterior hypothalamus. The one exception to this was a significant increase in GnRH mRNA expression in tissue collected from wild-type males exposed to bedding from another male. This is particularly intriguing since LH was not elevated in these males. These data replicate and extend our previous finding that ERalphaKO males do exhibit an LH surge in response to female pheromones. Thus, this neuroendocrine response is regulated by a steroid receptor other than ERalpha and does not require alterations in GnRH mRNA expression.

  3. Constitutive activation of gene expression by thyroid hormone receptor results from reversal of p53-mediated repression.

    PubMed Central

    Qi, J S; Desai-Yajnik, V; Yuan, Y; Samuels, H H

    1997-01-01

    Thyroid hormone receptor (T3R) is a member of the steroid hormone receptor gene family of nuclear hormone receptors. In most cells T3R activates gene expression only in the presence of its ligand, L-triiodothyronine (T3). However, in certain cell types (e.g., GH4C1 cells) expression of T3R leads to hormone-independent constitutive activation. This activation by unliganded T3R occurs with a variety of gene promoters and appears to be independent of the binding of T3R to specific thyroid hormone response elements (TREs). Previous studies indicate that this constitutive activation results from the titration of an inhibitor of transcription. Since the tumor suppresser p53 is capable of repressing a wide variety of gene promoters, we considered the possibility that the inhibitor is p53. Evidence to support this comes from studies indicating that expression of p53 blocks T3R-mediated constitutive activation in GH4C1 cells. In contrast with hormone-independent activation by T3R, p53 had little or no effect on T3-dependent stimulation which requires TREs. In addition, p53 mutants which oligomerize with wild-type p53 and interfere with its function also increase promoter activity. This enhancement is of similar magnitude to but is not additive with the stimulation mediated by unliganded T3R, suggesting that they target the same factor. Since p53 mutants are known to target wild-type p53 in the cell, this suggests that T3R also interacts with p53 in vivo and that endogenous levels of p53 act to suppress promoter activity. Evidence supporting both functional and physical interactions of T3R and p53 in the cell is presented. The DNA binding domain (DBD) of T3R is important in mediating constitutive activation, and the receptor DBD appears to functionally interact with the N terminus of p53 in the cell. In vitro binding studies indicate that the T3R DBD is important for interaction of T3R with p53 and that this interaction is reduced by T3. These findings are consistent with

  4. Nuclear hormone receptors: Roles of xenobiotic detoxification and sterol homeostasis in healthy aging.

    PubMed

    Hoffmann, Julia Marianne; Partridge, Linda

    2015-01-01

    Health during aging can be improved by genetic, dietary and pharmacological interventions. Many of these increase resistance to various stressors, including xenobiotics. Up-regulation of xenobiotic detoxification genes is a transcriptomic signature shared by long-lived nematodes, flies and mice, suggesting that protection of cells from toxicity of xenobiotics may contribute to longevity. Expression of genes involved in xenobiotic detoxification is controlled by evolutionarily conserved transcriptional regulators. Three closely related subgroups of nuclear hormone receptors (NHRs) have a major role, and these include DAF-12 and NHR-8 in C. elegans, DHR96 in Drosophila and FXR, LXRs, PXR, CAR and VDR in mammals. In the invertebrates, these NHRs have been experimentally demonstrated to play a role in extension of lifespan by genetic and environmental interventions. NHRs represent critical hubs in that they regulate detoxification enzymes with broad substrate specificities, metabolizing both endo- and xeno-biotics. They also modulate homeostasis of steroid hormones and other endogenous cholesterol derivatives and lipid metabolism, and these roles, as well as xenobiotic detoxification, may contribute to the effects of NHRs on lifespan and health during aging, an issue that is being increasingly addressed in C. elegans and Drosophila. Disentangling the contribution of these processes to longevity will require more precise understanding of the molecular mechanisms by which each is effected, including identification of ligands and co-regulators of NHRs, patterns of tissue-specificity and mechanisms of interaction between tissues. The roles of vertebrate NHRs in determination of health during aging and lifespan have yet to be investigated.

  5. Hormonal regulation of type II glucocorticoid receptor messenger ribonucleic acid in rat brain.

    PubMed

    Peiffer, A; Lapointe, B; Barden, N

    1991-10-01

    Differences in the regulation of type II glucocorticoid receptor (GR) mRNA levels in female rat brain regions involved in the control of the hypothalamic-pituitary-adrenal axis were studied by Northern blot analysis after chronic administration of corticosterone or dexamethasone to adrenalectomized (ADX), ovariectomized (OVX), and ADX/OVX animals. The effect of chronic estradiol or progesterone treatment of intact animals was also studied. Our results show that type II GR mRNA levels of ADX animals were significantly increased above control values in amygdala (140%) and hippocampus (196%), but not in hypothalamus. These increased transcript levels were down-regulated by corticosterone or dexamethasone, with the exception of those in the amygdala, where corticosterone had no effect. Ovariectomy significantly increased hypothalamic GR mRNA content (174%) over control values, and this increase was sensitive to dexamethasone. The combined effect of adrenalectomy/ovariectomy on GR mRNA levels was greater than that of adrenalectomy only in amygdala. Corticosterone increased amygdala transcript levels in OVX and ADX/OVX animals. Estradiol administration to intact animals raised the GR mRNA content of amygdala, while progesterone treatment had no effect on any of the brain regions studied. We conclude that there exists heterogeneity with respect to type II GR mRNA regulation by corticosterone and dexamethasone in brain regions of ADX female rats, and that certain limbic structures show greater sensitivity to these hormonal manipulations, suggesting a more prominent role in the regulation of the hypothalamic-pituitary-adrenal axis. Our results also suggest that circulating estrogens can influence the sensitivity of brain structures (i.e. hypothalamus and amygdala) to glucocorticoids by altering GR mRNA levels. These regions may represent integration sites at which gonadal steroids are able to alter stress hormone secretion.

  6. Estrogenic compounds decrease growth hormone receptor abundance and alter osmoregulation in Atlantic salmon

    USGS Publications Warehouse

    Lerner, Darren T.; Sheridan, Mark A.; McCormick, Stephen D.

    2012-01-01

    Exposure of Atlantic salmon smolts to estrogenic compounds is shown to compromise several aspects of smolt development. We sought to determine the underlying endocrine mechanisms of estrogen impacts on the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis. Smolts in freshwater (FW) were either injected 3 times over 10 days with 2 μg g−1 17β-estradiol (E2) or 150 μg g−1 4-nonylphenol (NP). Seawater (SW)-acclimated fish received intraperitoneal implants of 30 μg g−1 E2 over two weeks. Treatment with these estrogenic compounds increased hepatosomatic index and total plasma calcium. E2 and NP reduced maximum growth hormone binding by 30–60% in hepatic and branchial membranes in FW and SW, but did not alter the dissociation constant. E2 and NP treatment decreased plasma levels of IGF-I levels in both FW and SW. In FW E2 and NP decreased plasma GH whereas in SW plasma GH increased after E2 treatment. Compared to controls, plasma chloride concentrations of E2-treated fish were decreased 5.5 mM in FW and increased 10.5 mM in SW. There was no effect of NP or E2 on gill sodium–potassium adenosine triphosphatase (Na+/K+-ATPase) activity in FW smolts, whereas E2 treatment in SW reduced gill Na+/K+-ATPase activity and altered the number and size of ionocytes. Our data indicate that E2 downregulates the GH/IGF-I-axis and SW tolerance which may be part of its normal function for reproduction and movement into FW. We conclude that the mechanism of endocrine disruption of smolt development by NP is in part through alteration of the GH/IGF-I axis via reduced GH receptor abundance.

  7. Effects of plasticizers and their mixtures on estrogen receptor and thyroid hormone functions.

    PubMed

    Ghisari, Mandana; Bonefeld-Jorgensen, Eva Cecilie

    2009-08-25

    Plasticizers are additives used to increase the flexibility or plasticity of the material to which they are added, normally rigid plastic and as additives in paint and adhesives. They are suspected to interfere with the endocrine system, including the estrogen and the thyroid hormone (TH) systems. We investigated in vitro the thyroid hormone-like and estrogenic activities of a range of widely used plasticizers and phenols including benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), di(2-ethylhexyl) phthalate (DEHP), bis(2-ethylhexyl) adipate (DEHA), 4-tert-octylphenol (tOP), 4-chloro-3-methylphenol (CMP), 2,4-dichlorophenol (2,4-DCP), 2-phenylphenol (2-PP) and resorcinol. The TH disrupting potential was determined by the effect on the TH-dependent rat pituitary GH3 cell proliferation (T-screen). The estrogenic activities of the compounds were assessed in MVLN cells, stably transfected with an estrogen receptor (ER) luciferase reporter vector. Furthermore, the combined effect of a multi-components mixture of six plasticizers was evaluated for its estrogenic and TH-like activities. All the tested compounds, but 2-PP, significantly affected the GH3 cell proliferation. tOP, BBP and DBP activated ER transactivity, whereas DEHP antagonized the 17beta-estradiol induced ER function. The mixture significantly induced ER transactivity in an additive manner, whereas in the T-screen, the observed mixture effect was lower than predicted, suggesting a potential antagonizing effect of the mixture. In conclusion, the tested plasticizers and phenols elicited endocrine-disrupting potential that can be mediated via interference with the estrogen and TH systems. Moreover, the observed mixture effect stresses the importance of considering the combined effect of the compounds for risk assessment of human health. PMID:19463926

  8. Cathepsin H regulated by the thyroid hormone receptors associate with tumor invasion in human hepatoma cells.

    PubMed

    Wu, S-M; Huang, Y-H; Yeh, C-T; Tsai, M-M; Liao, C-H; Cheng, W-L; Chen, W-J; Lin, K-H

    2011-04-28

    Thyroid hormone, 3, 3', 5-triiodo-L-thyronine (T(3)), mediates cell growth, development and differentiation by binding to its nuclear receptors (TRs). The role of TRs in cancer is still undefined. Notably, hyperthyroxinemia has been reported to influence the rate of colon cancer in an experimental model of carcinogenesis in rats. Previous microarray analysis revealed that cathepsin H (CTSH) is upregulated by T(3) in HepG2-TR cells. We verified that mRNA and protein expression of CTSH are induced by T(3) in HepG2-TR cells and in thyroidectomized rats following administration of T(3). The possible thyroid hormone-responsive elements of the CTSH promoter localized to the nucleotides -2038 to -1966 and -1565 to -1501 regions. An in vitro functional assay showed that CTSH can increase metastasis. J7 cells overexpressing CTSH were inoculated into severe combined immune-deficient mice and these J7-CTSH mice displayed a greater metastatic potential than did J7-control mice. The clinicopathologic significance of CTSH expression in hepatocellular carcinoma (HCC) was also investigated. The CTSH overexpressing in HCC was associated with the presence of microvascular invasion (P=0.037). The microvascular invasion characteristic is closely related to our in vitro characterization of CTSH function. Our results show that T(3)-mediated upregulation of CTSH led to matrix metallopeptidase or extracellular signal-regulated kinase activation and increased cell migration. This study demonstrated that CTSH overexpression in a subset hepatoma may be TR dependent and suggests that this overexpression has an important role in hepatoma progression. PMID:21217776

  9. Amphetamine reward in food restricted mice lacking the melanin-concentrating hormone receptor-1.

    PubMed

    Geuzaine, Annabelle; Tyhon, Amélie; Grisar, Thierry; Brabant, Christian; Lakaye, Bernard; Tirelli, Ezio

    2014-04-01

    Chronic food restriction (FR) and maintenance of low body weight have long been known to increase the rewarding and motor-activating effects of addictive drugs. However, the neurobiological mechanisms through which FR potentiates drug reward remain largely unknown. Melanin-concentrating hormone (MCH) signaling could be one of these mechanisms since this peptide is involved in energy homeostasis and modulates mesolimbic dopaminergic transmission. The purpose of the present study was to test this hypothesis by investigating the impact of FR on amphetamine reward in wild-type (WT) and knockout mice lacking the melanin-concentrating hormone receptor-1 (MCHR1-KO). The rewarding effects of amphetamine (0.75-2.25 mg/kg, i.p.) were measured with the conditioned place preference (CPP) technique. The food of the mice was restricted to maintain their body weight at 80-85% of their free-feeding (FF) weight throughout the entire CPP experiment. Locomotor activity of the animals was recorded during the conditioning sessions. Our results show that locomotion of all the food-restricted mice treated with saline or amphetamine increased over the sessions whatever the genotype. On the place preference test, the amplitude of CPP induced by 0.75 mg/kg amphetamine was higher in food restricted WT mice than in free-fed WT mice and food restricted MCHR1-KO mice. However, FR did not affect amphetamine reward in MCHR1-KO mice. The present results indicate that MCH signaling could be involved in the ability of FR to increase amphetamine-induced CPP.

  10. Interactions between Two Different G Protein-Coupled Receptors in Reproductive Hormone-Producing Cells: The Role of PACAP and Its Receptor PAC1R

    PubMed Central

    Kanasaki, Haruhiko; Oride, Aki; Hara, Tomomi; Mijiddorj, Tselmeg; Sukhbaatar, Unurjargal; Kyo, Satoru

    2016-01-01

    Gonadotropin-releasing hormone (GnRH) and gonadotropins are indispensable hormones for maintaining female reproductive functions. In a similar manner to other endocrine hormones, GnRH and gonadotropins are controlled by their principle regulators. Although it has been previously established that GnRH regulates the synthesis and secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—both gonadotropins—from pituitary gonadotrophs, it has recently become clear that hypothalamic GnRH is under the control of hypothalamic kisspeptin. Prolactin, which is also known as luteotropic hormone and is released from pituitary lactotrophs, stimulates milk production in mammals. Prolactin is also regulated by hypothalamic factors, and it is thought that prolactin synthesis and release are principally under inhibitory control by dopamine through the dopamine D2 receptor. In addition, although it remains unknown whether it is a physiological regulator, thyrotropin-releasing hormone (TRH) is a strong secretagogue for prolactin. Thus, GnRH, LH and FSH, and prolactin are mainly regulated by hypothalamic kisspeptin, GnRH, and TRH, respectively. However, the synthesis and release of these hormones is also modulated by other neuropeptides in the hypothalamus. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a hypothalamic peptide that was first isolated from sheep hypothalamic extracts based on its ability to stimulate cAMP production in anterior pituitary cells. PACAP acts on GnRH neurons and pituitary gonadotrophs and lactotrophs, resulting in the modulation of their hormone producing/secreting functions. Furthermore, the presence of the PACAP type 1 receptor (PAC1R) has been demonstrated in these cells. We have examined how PACAP and PAC1R affect GnRH- and pituitary hormone-secreting cells and interact with their principle regulators. In this review, we describe our understanding of the role of PACAP and PAC1R in the regulation of GnRH neurons

  11. Structure of Liver Receptor Homolog-1 (NR5A2) with PIP3 hormone bound in the ligand binding pocket.

    PubMed

    Sablin, Elena P; Blind, Raymond D; Uthayaruban, Rubatharshini; Chiu, Hsiu-Ju; Deacon, Ashley M; Das, Debanu; Ingraham, Holly A; Fletterick, Robert J

    2015-12-01

    The nuclear receptor LRH-1 (Liver Receptor Homolog-1, NR5A2) is a transcription factor that regulates gene expression programs critical for many aspects of metabolism and reproduction. Although LRH-1 is able to bind phospholipids, it is still considered an orphan nuclear receptor (NR) with an unknown regulatory hormone. Our prior cellular and structural studies demonstrated that the signaling phosphatidylinositols PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3) bind and regulate SF-1 (Steroidogenic Factor-1, NR5A1), a close homolog of LRH-1. Here, we describe the crystal structure of human LRH-1 ligand binding domain (LBD) bound by PIP3 - the first phospholipid with a head group endogenous to mammals. We show that the phospholipid hormone binds LRH-1 with high affinity, stabilizing the receptor LBD. While the hydrophobic PIP3 tails (C16/C16) are buried inside the LRH-1 ligand binding pocket, the negatively charged PIP3 head group is presented on the receptor surface, similar to the phosphatidylinositol binding mode observed in the PIP3-SF-1 structure. Thus, data presented in this work reinforce our earlier findings demonstrating that signaling phosphatidylinositols regulate the NR5A receptors LRH-1 and SF-1. PMID:26416531

  12. Flow cytometry analysis of hormone receptors on human peripheral blood mononuclear cells to identify stress-induced neuroendocrine effects

    NASA Technical Reports Server (NTRS)

    Meehan, R. T.

    1986-01-01

    Understanding the role of circulating peptide hormones in the pathogenesis of space-flight induced disorders would be greatly facilitated by a method which monitors chronic levels of hormones and their effects upon in vivo cell physiology. Single and simultaneous multiparameter flow cytometry analysis was employed to identify subpopulations of mononuclear cells bearing receptors for ACTH, Endorphin, and Somatomedin-C using monoclonal antibodies and monospecific antisera with indirect immunofluorescence. Blood samples were obtained from normal donors and subjects participating in decompression chamber studies (acute stress), medical student academic examination (chronic stress), and a drug study (Dexamethasone). Preliminary results indicate most ACTH and Endorphin receptor positive cells are monocytes and B-cells, exhibit little diurnal variation but the relative percentages of receptor positive cells are influenced by exposure to various stressors and ACTH inhibition. This study demonstrates the capability of flow cytometry analysis to study cell surface hormone receptor regulation which should allow insight into neuroendocrine modulation of the immune and other cellular systems during exposure to stress or microgravity.

  13. US Incidence of Breast Cancer Subtypes Defined by Joint Hormone Receptor and HER2 Status

    PubMed Central

    Altekruse, Sean F.; Li, Christopher I.; Chen, Vivien W.; Clarke, Christina A.; Ries, Lynn A. G.; Cronin, Kathleen A.

    2014-01-01

    Background In 2010, Surveillance, Epidemiology, and End Results (SEER) registries began collecting human epidermal growth factor 2 (HER2) receptor status for breast cancer cases. Methods Breast cancer subtypes defined by joint hormone receptor (HR; estrogen receptor [ER] and progesterone receptor [PR]) and HER2 status were assessed across the 28% of the US population that is covered by SEER registries. Age-specific incidence rates by subtype were calculated for non-Hispanic (NH) white, NH black, NH Asian Pacific Islander (API), and Hispanic women. Joint HR/HER2 status distributions by age, race/ethnicity, county-level poverty, registry, stage, Bloom–Richardson grade, tumor size, and nodal status were evaluated using multivariable adjusted polytomous logistic regression. All statistical tests were two-sided. Results Among case patients with known HR/HER2 status, 36810 (72.7%) were found to be HR+/HER2−, 6193 (12.2%) were triple-negative (HR−/HER2−), 5240 (10.3%) were HR+/HER2+, and 2328 (4.6%) were HR−/HER2+; 6912 (12%) had unknown HR/HER2 status. NH white women had the highest incidence rate of the HR+/HER2− subtype, and NH black women had the highest rate of the triple-negative subtype. Compared with women with the HR+/HER2− subtype, triple-negative patients were more likely to be NH black and Hispanic; HR+/HER2+ patients were more likely to be NH API; and HR−/HER2+ patients were more likely to be NH black, NH API, and Hispanic. Patients with triple-negative, HR+/HER2+, and HR−/HER2+ breast cancer were 10% to 30% less likely to be diagnosed at older ages compared with HR+/HER2− patients and 6.4-fold to 20.0-fold more likely to present with high-grade disease. Conclusions In the future, SEER data can be used to monitor clinical outcomes in women diagnosed with different molecular subtypes of breast cancer for a large portion (approximately 28%) of the US population. PMID:24777111

  14. Central and direct regulation of testicular activity by gonadotropin-inhibitory hormone and its receptor.

    PubMed

    Ubuka, Takayoshi; Son, You Lee; Tobari, Yasuko; Narihiro, Misato; Bentley, George E; Kriegsfeld, Lance J; Tsutsui, Kazuyoshi

    2014-01-01

    Gonadotropin-inhibitory hormone (GnIH) was first identified in Japanese quail to be an inhibitor of gonadotropin synthesis and release. GnIH peptides have since been identified in all vertebrates, and all share an LPXRFamide (X = L or Q) motif at their C-termini. The receptor for GnIH is the G protein-coupled receptor 147 (GPR147), which inhibits cAMP signaling. Cell bodies of GnIH neurons are located in the paraventricular nucleus (PVN) in birds and the dorsomedial hypothalamic area (DMH) in most mammals. GnIH neurons in the PVN or DMH project to the median eminence to control anterior pituitary function via GPR147 expressed in gonadotropes. Further, GnIH inhibits gonadotropin-releasing hormone (GnRH)-induced gonadotropin subunit gene transcription by inhibiting the adenylate cyclase/cAMP/PKA-dependent ERK pathway in an immortalized mouse gonadotrope cell line (LβT2 cells). GnIH neurons also project to GnRH neurons that express GPR147 in the preoptic area (POA) in birds and mammals. Accordingly, GnIH can inhibit gonadotropin synthesis and release by decreasing the activity of GnRH neurons as well as by directly inhibiting pituitary gonadotrope activity. GnIH and GPR147 can thus centrally suppress testosterone secretion and spermatogenesis by acting in the hypothalamic-pituitary-gonadal axis. GnIH and GPR147 are also expressed in the testis of birds and mammals, possibly acting in an autocrine/paracrine manner to suppress testosterone secretion and spermatogenesis. GnIH expression is also regulated by melatonin, stress, and social environment in birds and mammals. Accordingly, the GnIH-GPR147 system may play a role in transducing physical and social environmental information to regulate optimal testicular activity in birds and mammals. This review discusses central and direct inhibitory effects of GnIH and GPR147 on testosterone secretion and spermatogenesis in birds and mammals.

  15. Fruit, Vegetable, and Animal Food Intake and Breast Cancer Risk by Hormone Receptor Status

    PubMed Central

    Bao, Ping-Ping; Shu, Xiao-Ou; Zheng, Ying; Cai, Hui; Ruan, Zhi-Xian; Gu, Kai; Su, Yinghao; Gao, Yu-Tang; Zheng, Wei; Lu, Wei

    2013-01-01

    Background The effects of diet on breast cancer are controversial and whether the effects vary with hormone receptor status has not been well investigated. This study evaluated the associations of dietary factors with risk for breast cancer overall and by hormone receptor status of tumors among Chinese women. Methods The Shanghai Breast Cancer Study, a large, population-based, case-control study, enrolled 3,443 cases and 3,474 controls in 1996–1998 (phase I) and 2002–2004 (phase II); 2,676 cases had ER and PR data. Dietary intake was assessed using a validated, quantitative, food frequency questionnaire (FFQ). Odds ratios (ORs) and 95% confidence intervals (95% CI) were derived from multivariate, polychotomous, unconditional logistic regression models. Results Total vegetable intake was inversely related to breast cancer risk, with an adjusted OR for the highest quintile of 0.80 (95% CI = 0.67–0.95; P trend=0.02). Reduced risk was also related to high intake of allium vegetables (P trend = 0.01) and fresh legumes (P trend = 0.0008). High intake of citrus fruits and rosaceae fruits were inversely associated with breast cancer risk (P trend = 0.003 and P trend = 0.004, respectively), although no consistent association was seen for total fruit intake. Elevated risk was observed for all types of meat and fish intake (all P trend <0.05), while intakes of eggs and milk were associated with a decreased risk of breast cancer (both P trend <0.05). There was little evidence that associations with dietary intakes varied across the four tumor subtypes or between ER+/PR+ and ER−/PR− tumors (P for heterogeneity >0.05). Conclusion Our results suggest that high intake of total vegetables, certain fruits, milk, and eggs may reduce the risk of breast cancer, while high consumption of animal-source foods may increase risk. The dietary associations did not appear to vary by ER/PR status. PMID:22860889

  16. Assembly and structural characterization of an authentic complex between human follicle stimulating hormone and a hormone-binding ectodomain of its receptor

    PubMed Central

    Fan, Qing R.; Hendrickson, Wayne A.

    2007-01-01

    Follicle stimulating hormone (FSH) is secreted from the pituitary gland to regulate reproduction in vertebrates. FSH signals through a G-protein coupled receptor (FSHR) on the target cell surface. We describe here the strategy to produce a soluble FSH-FSHR complex that involves the co-secretion of a truncated FSHR ectodomain (FSHRHB) and a covalently-linked FSHαβ heterodimer from baculovirus-infected insect cells. FSH binds to FSHRHB with a high affinity comparable to that for the full-length receptor. The crystal structure of the FSH-FSHRHB complex provides explanations for the high affinity and specificity of FSH interaction with FSHR, and it shows an unexpected dimerization of these complexes. Here we also compare the crystal structure with theoretical models of the FSH-FSHR binding mode. We conclude that the FSH-FSHRHB structure gives an authentic representation of FSH binding to intact FSHR. PMID:17045735

  17. Simian virus 40 late gene expression is regulated by members of the steroid/thyroid hormone receptor superfamily.

    PubMed

    Zuo, F; Mertz, J E

    1995-09-12

    Transcription of the late genes of simian virus 40 (SV40) is repressed during the early phase of the lytic cycle of infection of binding of cellular factors, called IBP-s, to the SV40 late promoter; repression is relieved after the onset of viral DNA replication by titration of these repressors. Preliminary data indicated that one of the major components of IBP-s was human estrogen-related receptor 1 (hERR1). We show here that several members of the steroid/thyroid hormone receptor superfamily, including testis receptor 2, thyroid receptor alpha 1 in combination with retinoid X receptor alpha, chicken ovalbumin upstream promoter transcription factors 1 and 2 (COUP-TF1 and COUP-TF2), as well as hERR1, possess the properties of IBP-s. These receptors bind specifically to hormone receptor binding sites present in the SV40 major late promoter. Recombinant COUP-TF1 specifically represses transcription from the SV40 major late promoter in a cell-free transcription system. Expression of COUP-TF1, COUP-TF2, or hERR1 in monkey cells results in repression of the SV40 late promoter, but not the early promoter, in the absence of the virally encoded large tumor antigen. Overexpression of COUP-TF1 leads to a delay in the early-to-late switch in SV40 gene expression during the lytic cycle of infection. Thus, members of this superfamily can play major direct roles in regulating expression of SV40. Possibly, natural or synthetic ligands to these receptors can serve as antiviral drugs. Our findings also provide the basis for the development of assays to screen for the ligands to testis receptor 2 and hERR1.

  18. Growth Hormone Induces Recurrence of Infantile Hemangiomas After Apparent Involution: Evidence of Growth Hormone Receptors in Infantile Hemangioma.

    PubMed

    Munabi, Naikhoba C O; Tan, Qian Kun; Garzon, Maria C; Behr, Gerald G; Shawber, Carrie J; Wu, June K

    2015-01-01

    Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence.

  19. Alanine-261 in intracellular loop III of the human gonadotropin-releasing hormone receptor is crucial for G-protein coupling and receptor internalization.

    PubMed Central

    Myburgh, D B; Millar, R P; Hapgood, J P

    1998-01-01

    Gonadotropin-releasing hormone (GnRH) is a decapeptide that regulates reproductive function via binding to the GnRH receptor, which is a G-protein-coupled receptor (GPCR). For several members of this family, the C-terminal domain of intracellular loop III is important in ligand-mediated coupling to G-proteins; mutations in that region can lead to constitutive activity. A specific alanine residue is involved in certain GPCRs, the equivalent of which is Ala-261 in the GnRH receptor. Mutation of this residue to Leu, Ile, Lys, Glu or Phe in the human GnRH receptor did not result in constitutive activity and instead led to complete uncoupling of the receptor (failure to support GnRH-stimulated inositol phosphate production). When this residue was mutated to Gly, Pro, Ser or Val, inositol phosphate production was still supported. All the mutants retained the ability to bind ligand, and the affinity for ligand, where measured, was unchanged. These results show that Ala-261 cannot be involved in ligand binding but is critical for coupling of the receptor to its cognate G-protein. Coupling is also dependent on the size of the residue in position 261. When the amino acid side chain has a molecular mass of less than 40 Da efficient coupling is still possible, but when its molecular mass exceeds 50 Da the receptor is uncoupled. Internalization studies on the Ala261-->Lys mutant showed a marked decrease in receptor internalization compared with the wild type, indicating that coupling is necessary for effective receptor internalization in the GnRH receptor system. Activation of protein kinase C (with PMA), but not protein kinase A (with forskolin) markedly increased the internalization of the mutant receptor while having a small effect on the wild-type receptor. PMID:9560319

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

    PubMed Central

    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. PMID:27468248

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

    PubMed

    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. PMID:27468248

  2. Targeting pioneering factor and hormone receptor cooperative pathways to suppress tumor progression

    PubMed Central

    Shah, Supriya; Prasad, Shikha; Knudsen, Karen E.

    2012-01-01

    Nuclear receptors and pioneer factors drive the development and progression of prostate cancer. In this disease, aggressive disease phenotypes and hormone therapy failures result from resurgent activity of androgen receptor (AR) and the upregulation of coactivator protein p300 and pioneer factors (e.g. GATA2 and FOXA1). Thus, a major current emphasis in the field is to identify mechanisms by which castrate-resistant AR activity and pioneer factor function can be combinatorially suppressed. Here we show that the turmeric spice isoflavone curcumin suppresses p300 and CBP occupancy at sites of AR function. Curcumin reduced the association of histone acetylation and pioneer factors, thereby suppressing AR residence and downstream target gene expression. Histone deacetylase inhibitors reversed the effects of curcumin on AR activity, further underscoring the impact of curcumin on altering the chromatin landscape. These functions precluded pioneer factor occupancy, leading ultimately to a suppression of ligand-dependent and ligand-independent AR residence on chromatin. Moreover, these functions were conserved even in cells with heightened pioneer factor activity, thus identifying a potential strategy to manage this subclass of tumors. Biological relevance was further identified using in vivo xenograft models mimicking disease progression. Curcumin cooperated in vivo with androgen deprivation as indicated by illustrated by a reduction in tumor growth and delay to the onset of castrate-resistant disease. Together, our results demonstrate the combinatorial impact of targeting AR and histone modification in prostate cancer, setting the stage for further development of curcumin as a novel agent to target AR signaling. PMID:22258452

  3. Differential social regulation of two pituitary gonadotropin-releasing hormone receptors.

    PubMed

    Au, Teresa M; Greenwood, Anna K; Fernald, Russell D

    2006-06-30

    In many vertebrates, social interactions regulate reproductive capacity by altering the activity of the hypothalamic-pituitary-gonadal (HPG) axis. To better understand the mechanisms underlying social regulation of reproduction, we investigated the relationship between social status and one main component of the HPG axis: expression levels of gonadotropin-releasing hormone receptor (GnRH-R). Social interactions dictate reproductive capacity in the cichlid fish Astatotilapia burtoni. Reproductively active territory holders suppress the HPG axis of non-territorial males through repeated aggressive encounters. To determine whether the expression of GnRH-R is socially regulated, we quantified mRNA levels of two GnRH-R variants in the pituitaries and brains of territorial (T) and non-territorial (NT) A. burtoni males. We found that T males had significantly higher levels of pituitary GnRH-R1 mRNA than NT males. In contrast, GnRH-R2 mRNA levels in the pituitary did not vary with social status. Pituitaries from both T and NT males expressed significantly higher mRNA levels of GnRH-R1 than GnRH-R2. GnRH mRNA levels in the brain correlated positively with GnRH-R1 mRNA levels in the pituitary but did not correlate with pituitary GnRH-R2. Measurements of GnRH-R1 and GnRH-R2 mRNA levels across the whole brain revealed no social status differences. These results show that, in addition to the known effects of social status on other levels of the HPG axis, GnRH receptor in the pituitary is also a target of social regulation.

  4. Endogenous interleukin-12: relationship with angiogenic factors, hormone receptors and nodal status in human breast carcinoma.

    PubMed

    Toi, M; Gion, M; Saji, H; Asano, M; Dittadi, R; Gilberti, S; Locopo, N; Gasparini, G

    1999-12-01

    Interleukin-12 (IL-12) is known to be a key cytokine for regulating immune response, but it is also known to provide some other biological function including inhibition of angiogenesis. We have determined using an enzymatic immunoassay the endogenous levels of IL-12 in 390 cytosols of primary breast cancers previously tested also for the angiogenic peptides, vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP). The concentration of IL-12 ranged from 0 to 7.6 ng/mg protein, and 124 (31.8%) out of 390 cancers showed a detectable dose (>0.1 ng/ml). There was no statistical association of IL-12 levels with tumor size and menopausal status. IL-12 levels tended to be higher in the tumors of node-positive patients as compared to those of node-negative ones (t-test, p=0.082). In addition, IL-12 levels were inversely associated with hormone receptor status, particularly progesterone receptor expression (p=0.0013). There was a significant inverse association between IL-12 and TP concentration (p=0.0007). The proportion of tumors with detectable levels of IL-12 and low levels of either VEGF or TP was higher among the patients with node-negative as compared to those with node-positive disease. On the contrary, the proportion of tumors with no detectable IL-12 and high levels of either VEGF or TP was higher in node-positive versus node-negative cancers. In conclusion, our study evaluated the balance between pro-angiogenic factors (TP and VEGF) and IL-12, as a detectable naturally occurring inhibitor of angiogenesis, in the same series of node-negative and node-positive breast cancers. Further studies are warranted to investigate the biological and clinical significance of the co-determination of pro and contra angiogenic factors in human breast carcinoma.

  5. Optimizing control of acromegaly: integrating a growth hormone receptor antagonist into the treatment algorithm.

    PubMed

    Clemmons, David R; Chihara, Kazuo; Freda, Pamela U; Ho, Ken K Y; Klibanski, Anne; Melmed, Shlomo; Shalet, Stephen M; Strasburger, Christian J; Trainer, Peter J; Thorner, Michael O

    2003-10-01

    Acromegaly is associated with significant morbidities and a 2- to 3-fold increase in mortality because of the excessive metabolic action of GH and IGF-I, a marker of GH output. Reductions in morbidity correspond with decreases in IGF-I, and mortality is lowered following normalization of IGF-I or GH levels. Therefore, this has become an important end point. Current guidelines for the treatment of acromegaly have not considered recent advances in medical therapy, in particular, the place of pegvisomant, a GH receptor antagonist. Treatment goals include normalizing biochemical markers, controlling tumor mass, preserving pituitary function, and relieving signs and symptoms. Surgery reduces tumor volume and is considered first-line therapy. Radiation reduces tumor volume and GH and IGF-I levels, but the onset of action is slow and hypopituitarism typically develops. Therefore, pharmacotherapy is often used following surgery or as first-line therapy for nonresectable tumors. Dopamine agonists can be considered in patients exhibiting minimal disease or those with GH-prolactin-cosecreting tumors but will not achieve hormone normalization in most patients. Somatostatin analogs effectively suppress GH and IGF-I in most patients, but intolerance (e.g. diarrhea, cramping, gallstones) can occur. Pegvisomant, the newest therapeutic option, blocks GH action at peripheral receptors, normalizes IGF-I levels, reduces signs and symptoms, and corrects metabolic defects. Pegvisomant does not appear to affect tumor size and has few adverse effects. Pegvisomant is the most effective drug treatment for acromegaly in normalizing IGF-I and producing a clinical response; it is the preferred agent in patients resistant to or intolerant of somatostatin analogs.

  6. Hormonal profile and androgen receptor study in prepubertal girls with hypertrichosis

    PubMed Central

    2014-01-01

    Background Prepubertal hypertrichosis is a reportedly benign condition characterized by an excessive growth of vellous hair in non-androgen dependent areas of the body compared to the amount usually present in normal subjects of the same age, race and sex. Although this condition is usually considered idiopathic and regarded as benign, it may be very disturbing cosmetically, causing significant patient and parental anxiety. Method We performed a hormonal and androgen receptor study in 42 prepubertal girls with hypertrichosis and 29 control girls from 2 to 8 years of age. Both groups underwent a determination of basal LH, FSH, 17OH progesterone, androstenedione, testosterone, estradiol and SHBG, abdominal ultrasound to assess ovarian morphology, and the number of androgen receptor CAG/GGC repeats in DNA obtained from peripheral leukocytes. Results The hypertrichosis score was higher in the cases compared to controls. Serum gonadotropins and sex steroids were similar in both groups, but SHBG was significantly lower in the girls with hypertrichosis (71.1 ± 2.9 vs 81.9 ± 3.0 nmol/L, p < 0.02). The distribution of shorter, larger and total alleles was not statistically different between cases and controls. The combined analysis of CAG/GGC, however, showed a significantly higher prevalence of the most androgen-sensitive haplotypes (1–2: <22CAG + 17/17GGC- < 14CAG + 17/18GGC) in girls with hypertrichosis compared to controls. Conclusions We conclude that girls with hypertrychosis exhibit AR(s) with enhanced sensitivity, which may facilitate the growth of their body hair. PMID:24745883

  7. Select steroid hormone glucuronide metabolites can cause Toll-like receptor 4 activation and enhanced pain

    PubMed Central

    Lewis, Susannah S.; Hutchinson, Mark R.; Frick, Morin M.; Zhang, Yingning; Maier, Steven F.; Sammakia, Tarek; Rice, Kenner C.; Watkins, Linda R.

    2014-01-01

    We have recently shown that several classes of glucuronide metabolites, including the morphine metabolite morphine-3-glucuronide and the ethanol metabolite ethyl glucuronide, cause toll like receptor 4 (TLR4)-dependent signalling in vitro and enhanced pain in vivo. Steroid hormones, including estrogens and corticosterone, are also metabolized through glucuronidation. Here we demonstrate that in silico docking predicts that corticosterone, corticosterone-21-glucuronide, estradiol, estradiol-3-glucuronide and estradiol-17-glucuronide all dock with the MD-2 component of the TLR4 receptor complex. In addition to each docking with MD-2, the docking of each was altered by pre-docking with (+)-naloxone, a TLR4 signaling inhibitor. As agonist versus antagonist activity cannot be determined from these in silico interactions, an in vitro study was undertaken to clarify which of these compounds can act in an agonist fashion. Studies using a cell line transfected with TLR4, necessary co-signaling molecules, and a reporter gene revealed that only estradiol-3-glucuronide and estradiol-17-glucuronide increased reporter gene product, indicative of TLR4 agonism. Finally, in in vivo studies, each of the 5 drugs was injected intrathecally at equimolar doses. In keeping with the in vitro results, only estradiol-3-glucuronide and estradiol-17-glucuronide caused enhanced pain. For both compounds, pain enhancement was blocked by the TLR4 antagonist lipopolysaccharide from Rhodobacter sphaeroides, evidence for the involvement in TLR4 in the resultant pain enhancement. These findings have implications for several chronic pain conditions, including migraine and tempromandibular joint disorder, in which pain episodes are more likely in cycling females when estradiol is decreasing and estradiol metabolites are at their highest. PMID:25218902

  8. Distribution of Tuberoinfundibular Peptide of 39 Residues and Its Receptor, Parathyroid Hormone 2 Receptor, in the Mouse Brain

    PubMed Central

    FABER, CATHERINE A.; DOBOLYI, ARPÁD; SLEEMAN, MARK; USDIN, TED B.

    2010-01-01

    Tuberoinfundibular peptide of 39 residues (TIP39) was identified as a potent parathyroid hormone 2 receptor (PTH2R) agonist. Existing anatomical data also support the suggestion that TIP39 is the PTH2R’s endogenous ligand, but a comprehensive comparison of TIP39 and PTH2R distributions has not been performed. In the present study, we compared the distributions of TIP39 and PTH2R on adjacent mouse brain sections. In addition, we determined the locations of PTH2R-expressing cell bodies by in situ hybridization histochemistry and by labeling β-galactosidase driven by the PTH2R promoter in knockin mice. An excellent correlation was found between the distributions of TIP39-containing fibers and PTH2R-containing cell bodies and fibers throughout the brain. TIP39 and the PTH2R are abundant in medial prefrontal, insular, and ectorhinal cortices, the lateral septal nucleus, the bed nucleus of the stria terminalis, the fundus striati, the amygdala, the ventral subiculum, the hypothalamus, midline and intralaminar thalamic nuclei, the medial geniculate body, the periaqueductal gray, the ventral tegmental area, the superior and inferior colliculi, the parabrachial nuclei, the locus coeruleus, subcoeruleus and periolivary areas, and the nucleus of the solitary tract. Furthermore, even the subregional distribution of TIP39- and PTH2R-immunoreactive fibers in these regions showed remarkable similarities, providing anatomical evidence that TIP39 may act on the PTH2R. Based on these observations and on previous pharmacological data, we propose that TIP39 is an endogenous ligand of the PTH2R and that they form a neuromodulator system, which is optimally positioned to regulate limbic, endocrine, and auditory brain functions. PMID:17394159

  9. Distribution of tuberoinfundibular peptide of 39 residues and its receptor, parathyroid hormone 2 receptor, in the mouse brain.

    PubMed

    Faber, Catherine A; Dobolyi, Arpád; Sleeman, Mark; Usdin, Ted B

    2007-06-01

    Tuberoinfundibular peptide of 39 residues (TIP39) was identified as a potent parathyroid hormone 2 receptor (PTH2R) agonist. Existing anatomical data also support the suggestion that TIP39 is the PTH2R's endogenous ligand, but a comprehensive comparison of TIP39 and PTH2R distributions has not been performed. In the present study, we compared the distributions of TIP39 and PTH2R on adjacent mouse brain sections. In addition, we determined the locations of PTH2R-expressing cell bodies by in situ hybridization histochemistry and by labeling beta-galactosidase driven by the PTH2R promoter in knockin mice. An excellent correlation was found between the distributions of TIP39-containing fibers and PTH2R-containing cell bodies and fibers throughout the brain. TIP39 and the PTH2R are abundant in medial prefrontal, insular, and ectorhinal cortices, the lateral septal nucleus, the bed nucleus of the stria terminalis, the fundus striati, the amygdala, the ventral subiculum, the hypothalamus, midline and intralaminar thalamic nuclei, the medial geniculate body, the periaqueductal gray, the ventral tegmental area, the superior and inferior colliculi, the parabrachial nuclei, the locus coeruleus, subcoeruleus and periolivary areas, and the nucleus of the solitary tract. Furthermore, even the subregional distribution of TIP39- and PTH2R-immunoreactive fibers in these regions showed remarkable similarities, providing anatomical evidence that TIP39 may act on the PTH2R. Based on these observations and on previous pharmacological data, we propose that TIP39 is an endogenous ligand of the PTH2R and that they form a neuromodulator system, which is optimally positioned to regulate limbic, endocrine, and auditory brain functions. Published 2007 Wiley-Liss, Inc.

  10. Low intelligence but not attention deficit hyperactivity disorder is associated with resistance to thyroid hormone caused by mutation R316H in the thyroid hormone receptor {beta} gene

    SciTech Connect

    Weiss, R.E.; Stein, M.A.; Chyna, B.; Phillips, W.; O`Brien, T.; Gutermuth, L.; Refetoff, S.; Duck, S.C.

    1994-06-01

    Resistance to thyroid hormone (RTH) is a syndrome of reduced responsiveness of tissues to thyroid hormone. The clinical manifestations are variable and 46-50% of children with RTH have attention deficit hyperactivity disorder (ADD). The authors present a new family with RTH (F120) found to have a mutation R316H in the thyroid hormone receptor {beta} (TR{beta}) gene identical for that reported in an unrelated family. Assignment of the mutant allele and haplotyping based on CA repeat polymorphism were done on 16 family members. Semistructured diagnostic interviews and psychometric testing were used to determine the psychiatric diagnosis of 12 family members by examiners blinded to the genotype. Three subjects were identified to have the R316H allele as well as mildly elevated free T{sub 4} index (168 {+-} 12; normal range 77-135) and nonsuppressed TSH (4.1 {+-} 1.7 mU/L). Only 2 of the subjects with RTH were found to have ADD, while one family member homozygous for the wild type TR{beta} and normal thyroid function tests also had ADD. Unaffected family members had higher full scale intelligence quotients ({vert_bar}Q) (93 {+-} 7) than any of the 3 family members with RTH (77 {+-} 5, p = 0.006). These data do not support the genetic linkage of ADD and RTH, but do suggest that RTH is associated with lower IQ scores that may confer a high likelihood of exhibiting ADD symptoms. 20 refs., 2 figs., 2 tabs.

  11. Functional Authentication of a Novel Gastropod Gonadotropin-Releasing Hormone Receptor Reveals Unusual Features and Evolutionary Insight

    PubMed Central

    Kavanaugh, Scott I.

    2016-01-01

    A gonadotropin-releasing hormone (GnRH)-like molecule was previously identified in a gastropod, Aplysia californica, and named ap-GnRH. In this study, we cloned the full-length cDNA of a putative ap-GnRH receptor (ap-GnRHR) and functionally authenticated this receptor as a bona fide ap-GnRHR. This receptor contains two potential translation start sites, each accompanied by a Kozak sequence, suggesting the translation of a long and a short form of the receptor is possible. The putative ap-GnRHR maintains the conserved structural motifs of GnRHR-like receptors and shares 45% sequence identity with the octopus GnRHR. The expression of the putative ap-GnRHR short form is ubiquitous in all tissues examined, whereas the long form is only expressed in parts of the central nervous system, osphradium, small hermaphroditic duct, and ovotestis. The cDNA encoding the long or the short receptor was transfected into the Drosophila S2 cell line and subject to a radioreceptor assay using 125I-labeled ap-GnRH as the radioligand. Further, the transfected cells were treated with various concentrations of ap-GnRH and measured for the accumulation of cAMP and inositol monophosphate (IP1). Radioreceptor assay revealed that only the long receptor bound specifically to the radioligand. Further, only the long receptor responded to ap-GnRH with an increased accumulation of IP1, but not cAMP. Our studies show that despite the more prevalent expression of the short receptor, only the long receptor is the functional ap-GnRHR. Importantly, this is only the second report on the authentication of a protostome GnRHR, and based on the function and the phylogenetic grouping of ap-GnRHR, we suggest that this receptor is more similar to protostome corazonin receptors than chordate GnRHRs. PMID:27467252

  12. Functional Authentication of a Novel Gastropod Gonadotropin-Releasing Hormone Receptor Reveals Unusual Features and Evolutionary Insight.

    PubMed

    Kavanaugh, Scott I; Tsai, Pei-San

    2016-01-01

    A gonadotropin-releasing hormone (GnRH)-like molecule was previously identified in a gastropod, Aplysia californica, and named ap-GnRH. In this study, we cloned the full-length cDNA of a putative ap-GnRH receptor (ap-GnRHR) and functionally authenticated this receptor as a bona fide ap-GnRHR. This receptor contains two potential translation start sites, each accompanied by a Kozak sequence, suggesting the translation of a long and a short form of the receptor is possible. The putative ap-GnRHR maintains the conserved structural motifs of GnRHR-like receptors and shares 45% sequence identity with the octopus GnRHR. The expression of the putative ap-GnRHR short form is ubiquitous in all tissues examined, whereas the long form is only expressed in parts of the central nervous system, osphradium, small hermaphroditic duct, and ovotestis. The cDNA encoding the long or the short receptor was transfected into the Drosophila S2 cell line and subject to a radioreceptor assay using 125I-labeled ap-GnRH as the radioligand. Further, the transfected cells were treated with various concentrations of ap-GnRH and measured for the accumulation of cAMP and inositol monophosphate (IP1). Radioreceptor assay revealed that only the long receptor bound specifically to the radioligand. Further, only the long receptor responded to ap-GnRH with an increased accumulation of IP1, but not cAMP. Our studies show that despite the more prevalent expression of the short receptor, only the long receptor is the functional ap-GnRHR. Importantly, this is only the second report on the authentication of a protostome GnRHR, and based on the function and the phylogenetic grouping of ap-GnRHR, we suggest that this receptor is more similar to protostome corazonin receptors than chordate GnRHRs. PMID:27467252

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

    SciTech Connect

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

    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.

  14. Multifunctional receptor model for dioxin and related compound toxic action: possible thyroid hormone-responsive effector-linked site.

    PubMed Central

    McKinney, J D

    1989-01-01

    Molecular/theoretical modeling studies have revealed that thyroid hormones and toxic chlorinated aromatic hydrocarbons of environmental significance (for which dioxin or TCDD is the prototype) have similar structural properties that could be important in molecular recognition in biochemical systems. These molecular properties include a somewhat rigid, sterically accessible and polarizable aromatic ring and size-limited, hydrophobic lateral substituents, usually contained in opposite adjoining rings of a diphenyl compound. These molecular properties define the primary binding groups thought to be important in molecular recognition of both types of structures in biochemical systems. Similar molecular reactivities are supported by the demonstration of effective specific binding of thyroid hormones and chlorinated aromatic hydrocarbons with four different proteins, enzymes, or receptor preparations that are known or suspected to be involved in the expression of thyroid hormone activity. These binding interactions represent both aromatic-aromatic (stacking) and molecular cleft-type recognition processes. A multiple protein or multifunctional receptor-ligand binding mechanism model is proposed as a way of visualizing the details and possible role of both the stacking and cleft type molecular recognition factors in the expression of biological activity. The model suggests a means by which hormone-responsive effector-linked sites (possible protein-protein-DNA complexes) can maintain highly structurally specific control of hormone action. Finally, the model also provides a theoretical basis for the design and conduct of further biological experimentation on the molecular mechanism(s) of action of toxic chlorinated aromatic hydrocarbons and thyroid hormones. Images FIGURE 3. A FIGURE 3. B FIGURE 3. C FIGURE 3. D PMID:2551666

  15. Lipoprotein receptor-related protein 6 is required for parathyroid hormone-induced Sost suppression.

    PubMed

    Li, Changjun; Wang, Weishan; Xie, Liang; Luo, Xianghang; Cao, Xu; Wan, Mei

    2016-01-01

    Parathyroid hormone (PTH) suppresses the expression of the bone formation inhibitor sclerostin (Sost) in osteocytes by inducing nuclear accumulation of histone deacetylases (HDACs) to inhibit the myocyte enhancer factor 2 (MEF2)-dependent Sost bone enhancer. Previous studies revealed that lipoprotein receptor-related protein 6 (LRP6) mediates the intracellular signaling activation and the anabolic bone effect of PTH. Here, we investigated whether LRP6 mediates the inhibitory effect of PTH on Sost using an osteoblast-specific Lrp6-knockout (LRP6-KO) mouse model. An increased level of Sost mRNA expression was detected in femur tissue from LRP6-KO mice, compared to wild-type littermates. The number of osteocytes expressing sclerostin protein was also increased in bone tissue of LRP6-KO littermates, indicating a negative regulatory role of LRP6 on Sost/sclerostin. In wild-type littermates, intermittent PTH treatment significantly suppressed Sost mRNA expression in bone and the number of sclerostin(+) osteocytes, while the effect of PTH was much less significant in LRP6-KO mice. Additionally, PTH-induced downregulation of MEF2C and 2D, as well as HDAC changes in osteocytes, were abrogated in LRP6-KO mice. These data indicate that LRP6 is required for PTH suppression of Sost expression.

  16. Regulation of the growth hormone (GH) receptor and GH-binding protein mRNA

    SciTech Connect

    Kaji, Hidesuke; Ohashi, Shin-Ichirou; Abe, Hiromi; Chihara, Kazuo

    1994-12-31

    In fasting rats, a transient increase in growth hormone-binding protein (GHBP) mRNA levels was observed after 1 day, in muscle, heart, and liver, but not in fat tissues. The liver GH receptor (GHR) mRNA level was significantly increased after 1 day (but not after 5 days) of bovine GH (bGH) treatment in fed rats. Both the liver GHR mRNA level and the net increment of plasma IGF-I markedly decreased after 5 days of bGH administration in fasting rats. These findings suggest that GHR and GHBP mRNAs in the liver are expressed in a different way and that the expression of GHBP mRNA is regulated differently between tissues, at least in rats. The results also suggest that refractoriness to GH in a sustained fasting state might be beneficial in preventing anabolic effects of GH. In humans, GHR mRNA in lymphocytes, from subjects with either GH-deficiency or acromegaly, could be detected by the reverse transcription-polymerase chain reaction method. In one patient with partial GH insensitivity, a heterozygous missense mutation (P561T) was identified in the cytoplasmic domain of GHR. 15 refs., 4 figs.

  17. Growth hormone receptor exon 3 isoforms and their implication in growth disorders and treatment.

    PubMed

    Jorge, Alexander A L; Arnhold, Ivo J P

    2009-04-01

    Human recombinant growth hormone (hGH) has been used to treat short stature in several different conditions, but considerable inter-individual variation in short- and long-term growth response exists. Pharmacogenomics can provide important insights into hGH therapy. The GH receptor (GHR) is the first key molecule mediating GH action. In the past 3 years, a common GHR polymorphism reflecting the presence (GHRfl) or absence (GHRd3) of exon 3 has been under intensive investigation regarding its influence on the response to hGH therapy. Studies that evaluated response to GH treatment determined by these two GHR isoforms in children with GH deficiency, girls with Turner syndrome, children born small for gestational age and patients with acromegaly showed that patients carrying the GHRd3 allele demonstrated a greater GH sensitivity than patients homozygous for the GHRfl allele. Other studies presented contradictory data, however, which may be caused by confounding factors such as small sample sizes and differences in experimental design. This GHR exon 3 genotype is the first identified genetic factor found to modulate the individual response to GH therapy. This article reviews the historical aspects and pharmacogenetic studies published to date in relation to this GHR polymorphism. The analyses of present and future validation studies may define the use of this and other polymorphisms in clinical practice, moving from pharmacogenetics to routine application and allowing individualization of hGH doses to optimize final outcome.

  18. Targeted chromatin binding and histone acetylation in vivo by thyroid hormone receptor during amphibian development.

    PubMed

    Sachs, L M; Shi, Y B

    2000-11-21

    Amphibian metamorphosis is marked by dramatic, thyroid hormone (TH)-induced changes involving gene regulation by TH receptor (TR). It has been postulated that TR-mediated gene regulation involves chromatin remodeling. In the absence of ligand, TR can repress gene expression by recruiting a histone deacetylase complex, whereas liganded TR recruits a histone acetylase complex for gene activation. Earlier studies have led us to propose a dual function model for TR during development. In premetamorphic tadpoles, unliganded TR represses transcription involving histone deacetylation. During metamorphosis, endogenous TH allows TR to activate gene expression through histone acetylation. Here using chromatin immunoprecipitation assay, we directly demonstrate TR binding to TH response genes constitutively in vivo in premetamorphic tadpoles. We further show that TH treatment leads to histone deacetylase release from TH response gene promoters. Interestingly, in whole animals, changes in histone acetylation show little correlation with the expression of TH response genes. On the other hand, in the intestine and tail, where TH response genes are known to be up-regulated more dramatically by TH than in most other organs, we demonstrate that TH treatment induces gene activation and histone H4 acetylation. These data argue for a role of histone acetylation in transcriptional regulation by TRs during amphibian development in some tissues, whereas in others changes in histone acetylation levels may play no or only a minor role, supporting the existence of important alternative mechanisms in gene regulation by TR.

  19. Differential network analysis reveals the genome-wide landscape of estrogen receptor modulation in hormonal cancers

    PubMed Central

    Hsiao, Tzu-Hung; Chiu, Yu-Chiao; Hsu, Pei-Yin; Lu, Tzu-Pin; Lai, Liang-Chuan; Tsai, Mong-Hsun; Huang, Tim H.-M.; Chuang, Eric Y.; Chen, Yidong

    2016-01-01

    Several mutual information (MI)-based algorithms have been developed to identify dynamic gene-gene and function-function interactions governed by key modulators (genes, proteins, etc.). Due to intensive computation, however, these methods rely heavily on prior knowledge and are limited in genome-wide analysis. We present the modulated gene/gene set interaction (MAGIC) analysis to systematically identify genome-wide modulation of interaction networks. Based on a novel statistical test employing conjugate Fisher transformations of correlation coefficients, MAGIC features fast computation and adaption to variations of clinical cohorts. In simulated datasets MAGIC achieved greatly improved computation efficiency and overall superior performance than the MI-based method. We applied MAGIC to construct the estrogen receptor (ER) modulated gene and gene set (representing biological function) interaction networks in breast cancer. Several novel interaction hubs and functional interactions were discovered. ER+ dependent interaction between TGFβ and NFκB was further shown to be associated with patient survival. The findings were verified in independent datasets. Using MAGIC, we also assessed the essential roles of ER modulation in another hormonal cancer, ovarian cancer. Overall, MAGIC is a systematic framework for comprehensively identifying and constructing the modulated interaction networks in a whole-genome landscape. MATLAB implementation of MAGIC is available for academic uses at https://github.com/chiuyc/MAGIC. PMID:26972162

  20. Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.

    PubMed

    Sulaica, Elisabeth; Han, Tiffany; Wang, Weiqun; Bhat, Raksha; Trivedi, Meghana V; Niravath, Polly

    2016-06-01

    Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients.

  1. Unliganded thyroid hormone receptor regulates metamorphic timing via the recruitment of histone deacetylase complexes.

    PubMed

    Shi, Yun-Bo

    2013-01-01

    Anuran metamorphosis involves a complex series of tissue transformations that change an aquatic tadpole to a terrestrial frog and resembles the postembryonic perinatal period in mammals. Thyroid hormone (TH) plays a causative role in amphibian metamorphosis and its effect is mediated by TH receptors (TRs). Molecular analyses during Xenopus development have shown that unliganded TR recruits histone deacetylase (HDAC)-containing N-CoR/SMRT complexes and causes histone deacetylation at target genes while liganded TR leads to increased histone acetylations and altered histone methylations at target genes. Transgenic studies involving mutant TR-cofactors have shown that corepressor recruitment by unliganded TR is required to ensure proper timing of the onset of metamorphosis while coactivator levels influence the rate of metamorphic progression. In addition, a number of factors that can influence cellular free TH levels appear to contribute the timing of metamorphic transformations of different organs by regulating the levels of unliganded vs. liganded TR in an organ-specific manner. Thus, the recruitment of HDAC-containing corepressor complexes by unliganded TR likely controls both the timing of the initiation of metamorphosis and the temporal regulation of organ-specific transformations. Similar mechanisms likely mediate TR function in mammals as the maturation of many organs during postembryonic development is dependent upon TH and resembles organ metamorphosis in amphibians.

  2. Carboxylesterases Are Uniquely Expressed among Tissues and Regulated by Nuclear Hormone Receptors in the Mouse

    PubMed Central

    Jones, Ryan D.; Taylor, Anna M.; Tong, Ernest Y.

    2013-01-01

    Carboxylesterases (CES) are a well recognized, yet incompletely characterized family of proteins that catalyze neutral lipid hydrolysis. Some CES have well-defined roles in xenobiotic clearance, pharmacologic prodrug activation, and narcotic detoxification. In addition, emerging evidence suggests other CES may have roles in lipid metabolism. Humans have six CES genes, whereas mice have 20 Ces genes grouped into five isoenzyme classes. Perhaps due to the high sequence similarity shared by the mouse Ces genes, the tissue-specific distribution of expression for these enzymes has not been fully addressed. Therefore, we performed studies to provide a comprehensive tissue distribution analysis of mouse Ces mRNAs. These data demonstrated that while the mouse Ces family 1 is highly expressed in liver and family 2 in intestine, many Ces genes have a wide and unique tissue distribution defined by relative mRNA levels. Furthermore, evaluating Ces gene expression in response to pharmacologic activation of lipid- and xenobiotic-sensing nuclear hormone receptors showed differential regulation. Finally, specific shifts in Ces gene expression were seen in peritoneal macrophages following lipopolysaccharide treatment and in a steatotic liver model induced by high-fat feeding, two model systems relevant to disease. Overall these data show that each mouse Ces gene has its own distinctive tissue expression pattern and suggest that some CES may have tissue-specific roles in lipid metabolism and xenobiotic clearance. PMID:23011759

  3. Deficiency of the calcium-sensing receptor in the kidney causes parathyroid hormone-independent hypocalciuria.

    PubMed

    Toka, Hakan R; Al-Romaih, Khaldoun; Koshy, Jacob M; DiBartolo, Salvatore; Kos, Claudine H; Quinn, Stephen J; Curhan, Gary C; Mount, David B; Brown, Edward M; Pollak, Martin R

    2012-11-01

    Rare loss-of-function mutations in the calcium-sensing receptor (Casr) gene lead to decreased urinary calcium excretion in the context of parathyroid hormone (PTH)-dependent hypercalcemia, but the role of Casr in the kidney is unknown. Using animals expressing Cre recombinase driven by the Six2 promoter, we generated mice that appeared grossly normal but had undetectable levels of Casr mRNA and protein in the kidney. Baseline serum calcium, phosphorus, magnesium, and PTH levels were similar to control mice. When challenged with dietary calcium supplementation, however, these mice had significantly lower urinary calcium excretion than controls (urinary calcium to creatinine, 0.31±0.03 versus 0.63±0.14; P=0.001). Western blot analysis on whole-kidney lysates suggested an approximately four-fold increase in activated Na(+)-K(+)-2Cl(-) cotransporter (NKCC2). In addition, experimental animals exhibited significant downregulation of Claudin14, a negative regulator of paracellular cation permeability in the thick ascending limb, and small but significant upregulation of Claudin16, a positive regulator of paracellular cation permeability. Taken together, these data suggest that renal Casr regulates calcium reabsorption in the thick ascending limb, independent of any change in PTH, by increasing the lumen-positive driving force for paracellular Ca(2+) transport.

  4. Effects of perfluoroalkyl acids on the function of the thyroid hormone and the aryl hydrocarbon receptor.

    PubMed

    Long, Manhai; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

    2013-11-01

    Perfluoroalkyl acids (PFAAs) are perfluorinated compounds that widely exist in the environment and can elicit adverse effects including endocrine disruption in humans and animals. This study investigated the effect of seven PFAAs on the thyroid hormone (TH) system assessing the proliferation of the 3,3',5-triiodo-L-thryonine (T3)-dependent rat pituitary GH3 cells using the T-screen assay and the effect on the aryl hydrocarbon receptor (AhR) transactivation in the AhR-luciferase reporter gene bioassay. A dose-dependent impact on GH3 cells was observed in the range 1×10(-9)-1×10(-4) M: seven PFAAs (perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA)) inhibited the GH3 cell growth, and four PFAAs (PFOS, PFHxS, PFNA, and PFUnA) antagonized the T3-induced GH3 cell proliferation. At the highest test concentration, PFHxS showed a further increase of the T3-induced GH3 growth. Among the seven tested PFAAs, only PFDoA and PFDA elicited an activating effect on the AhR. In conclusion, PFAAs possess in vitro endocrine-disrupting potential by interfering with TH and AhR functions, which need to be taken into consideration when assessing the impact on human health. PMID:23539207

  5. Reproductive factors and hormone receptor status among very young (<35 years) breast cancer patients.

    PubMed

    Jia, Xiaoqing; Liu, Guangyu; Mo, Miao; Cheng, Jingyi; Shen, Zhenzhou; Shao, Zhimin

    2015-09-15

    The prognosis for breast cancer occurs in young women is usually poor. The impact of different reproductive factors on disease characteristics is still largely unknown. We analyzed 261 patients aged ≤35 years old who were treated at the Cancer Hospital of Fudan University, Shanghai, China. The relationships between certain reproductive factors (age at menarche, parity, number of children, breastfeeding, history of abortion, age at first full-term pregnancy and oral contraceptive (OC) use) and disease characteristics were evaluated. Compared with patients who experienced fewer full-term pregnancies (<2 times), the patients with more full-term pregnancies (≥2 times) exhibited higher percentage of ER-positive tumors (61.5%) (P = 0.015), and patients whose age of menarche was ≥15 years exhibited a greater chance of PR-positive tumors (64.8%) (P = 0.036) compared with those whose age of menarche was <15 years old. Additionally, patients who had taken OCs were more likely to present with late-stage tumors (II stage or later) (87.5%) (P = 0.002) than patients who had never taken OCs. Our study provides evidence that women with more full-term pregnancies and later age at menarche are more possible to exhibit hormone receptor-positive tumors. Additionally, patients who have taken OCs are more likely to present with advanced disease.

  6. Tuberoinfundibular peptide of 39 residues (TIP39): molecular structure and activity for parathyroid hormone 2 receptor.

    PubMed

    Della Penna, K; Kinose, F; Sun, H; Koblan, K S; Wang, H

    2003-01-01

    The neuropeptide TIP39 was recently purified from bovine hypothalamus based on the ability of the peptide to activate the parathyroid hormone 2 receptor (PTH2R) ( Nat. Neurosci. 2 (1999) 941). PTH2R is abundantly expressed in the nervous system, and its expression pattern suggests that it may play a role in modulation of pituitary function and in nociception. Towards understanding the physiological role of TIP39 and PTH2R, we cloned human, mouse and rat TIP39 gene. Our results revealed that: (1) the mature peptide is processed from a precursor; (2) TIP39 peptide is highly conserved among species; and (3) TIP39 from all species activates adenylyl cyclase and elevates intracellular calcium levels through PTH2R. We also defined and compared the structure-activity relationship of TIP39 on both activation of adenylyl cyclase and calcium mobilization pathways through PTH2R, finding common and differential determinants of TIP39 that are required for these pathways. Furthermore, we observed that TIP39 elevates intracellular calcium levels in primary dorsal root ganglion neurons whereas the peptide inactive on PTH2R do not, suggesting that TIP39 may activate these neurons important for nociception in vivo through PTH2R-dependent mechanisms.

  7. Broad-spectrum therapeutic suppression of metastatic melanoma through nuclear hormone receptor activation.

    PubMed

    Pencheva, Nora; Buss, Colin G; Posada, Jessica; Merghoub, Taha; Tavazoie, Sohail F

    2014-02-27

    Melanoma metastasis is a devastating outcome lacking an effective preventative therapeutic. We provide pharmacologic, molecular, and genetic evidence establishing the liver-X nuclear hormone receptor (LXR) as a therapeutic target in melanoma. Oral administration of multiple LXR agonists suppressed melanoma invasion, angiogenesis, tumor progression, and metastasis. Molecular and genetic experiments revealed these effects to be mediated by LXRβ, which elicits these outcomes through transcriptional induction of tumoral and stromal apolipoprotein-E (ApoE). LXRβ agonism robustly suppressed tumor growth and metastasis across a diverse mutational spectrum of melanoma lines. LXRβ targeting significantly prolonged animal survival, suppressed the progression of established metastases, and inhibited brain metastatic colonization. Importantly, LXRβ activation displayed melanoma-suppressive cooperativity with the frontline regimens dacarbazine, B-Raf inhibition, and the anti-CTLA-4 antibody and robustly inhibited melanomas that had acquired resistance to B-Raf inhibition or dacarbazine. We present a promising therapeutic approach that uniquely acts by transcriptionally activating a metastasis suppressor gene.

  8. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications

    PubMed Central

    Kopchick, John J.; List, Edward O.; Kelder, Bruce; Gosney, Elahu S.; Berryman, Darlene E.

    2013-01-01

    The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant’s preclinical and clinical trials, and provide data suggesting pegvisomant’s therapeutic value in selected types of cancer. PMID:24035867

  9. Thyroid status affects number and localization of thyroid hormone receptor expressing mast cells in bone marrow.

    PubMed

    Siebler, T; Robson, H; Bromley, M; Stevens, D A; Shalet, S M; Williams, G R

    2002-01-01

    Thyroid hormone (T(3)) plays a key role in endochondral ossification. The process relies on the coordinated synthesis and degradation of cartilage matrix and is disrupted in juvenile hypothyroidism, leading to abnormal skeletal development. Mast cells synthesize and store matrix-degrading enzymes. We examined whether thyroid status influences skeletal mast cell distribution in growing rats to determine whether they might modulate the actions of T(3) in bone. Tibiae were collected for histological, histochemical, immunohistochemical, and immunofluorescence analysis. Mast cells were increased throughout the bone marrow in hypothyroid rats compared with euthyroid, thyrotoxic, and hypothyroid-thyroxine replaced animals. Large numbers were present in metaphyseal marrow adjacent to the growth plate in hypothyroid animals and cells were distributed evenly throughout the marrow. Very few mast cells were present in metaphyseal marrow in other groups, but their numbers increased with increasing distance from the growth plate. T(3) receptor alpha1 (TRalpha1) was expressed in the nucleus and cytoplasm of skeletal mast cells, whereas TRalpha2 and TRbeta1 were restricted to the cytoplasm. Localization of TRs was not affected by altered thyroid status. Thus, disrupted endochondral ossification in hypothyroidism may be mediated in part by skeletal mast cells, which express TR proteins and may function as T(3) target cells.

  10. Phospholipase D2-dependent inhibition of the nuclear hormone receptor PPARgamma by cyclic phosphatidic acid.

    PubMed

    Tsukahara, Tamotsu; Tsukahara, Ryoko; Fujiwara, Yuko; Yue, Junming; Cheng, Yunhui; Guo, Huazhang; Bolen, Alyssa; Zhang, Chunxiang; Balazs, Louisa; Re, Fabio; Du, Guangwei; Frohman, Michael A; Baker, Daniel L; Parrill, Abby L; Uchiyama, Ayako; Kobayashi, Tetsuyuki; Murakami-Murofushi, Kimiko; Tigyi, Gabor

    2010-08-13

    Cyclic phosphatidic acid (1-acyl-2,3-cyclic-glycerophosphate, CPA), one of nature's simplest phospholipids, is found in cells from slime mold to humans and has a largely unknown function. We find here that CPA is generated in mammalian cells in a stimulus-coupled manner by phospholipase D2 (PLD2) and binds to and inhibits the nuclear hormone receptor PPARgamma with nanomolar affinity and high specificity through stabilizing its interaction with the corepressor SMRT. CPA production inhibits the PPARgamma target-gene transcription that normally drives adipocytic differentiation of 3T3-L1 cells, lipid accumulation in RAW264.7 cells and primary mouse macrophages, and arterial wall remodeling in a rat model in vivo. Inhibition of PLD2 by shRNA, a dominant-negative mutant, or a small molecule inhibitor blocks CPA production and relieves PPARgamma inhibition. We conclude that CPA is a second messenger and a physiological inhibitor of PPARgamma, revealing that PPARgamma is regulated by endogenous agonists as well as by antagonists. PMID:20705243

  11. The fax-1 nuclear hormone receptor regulates axon pathfinding and neurotransmitter expression.

    PubMed

    Much, J W; Slade, D J; Klampert, K; Garriga, G; Wightman, B

    2000-02-01

    Specification of neuron identity requires the activation of a number of discrete developmental programs. Among these is pathway selection by growth cones: in order for a neuron's growth cone to respond appropriately to guidance cues presented by other cells or the extracellular matrix, the neuron must express genes to mediate the response. The fax-1 gene of C. elegans is required for pathfinding of axons that extend along the ventral nerve cord. We show that fax-1 is also required for pathfinding of axons in the nerve ring, the largest nerve bundle in the nematode, and for normal expression of FMRFamide-like neurotransmitters in the AVK interneurons. The fax-1 gene encodes a member of the superfamily of nuclear hormone receptors and has a DNA-binding domain related to the human PNR and Drosophila Tailless proteins. We observe fax-1 expression in embryonic neurons, including the AVK interneurons, just prior to axon extension, but after neurogenesis. These data suggest that fax-1 coordinately regulates the transcription of genes that function in the selection of axon pathways, neurotransmitter expression and, perhaps, other aspects of the specification of neuron identity.

  12. Intracellular colocalization of HAP1/STBs with steroid hormone receptors and its enhancement by a proteasome inhibitor

    SciTech Connect

    Fujinaga, Ryutaro; Takeshita, Yukio; Yoshioka, Kazuhiro; Nakamura, Hiroyuki; Shinoda, Shuhei; Islam, Md. Nabiul; Jahan, Mir Rubayet; Yanai, Akie; Kokubu, Keiji; Shinoda, Koh

    2011-07-15

    The stigmoid body (STB) is a cytoplasmic inclusion containing huntingtin-associated protein 1 (HAP1), and HAP1/STB formation is induced by transfection of the HAP1 gene into cultured cells. In the present study, we examined the intracellular colocalization of HAP1/STBs with steroid hormone receptors (SHRs), including the androgen receptor (AR), estrogen receptor, glucocorticoid receptor (GR), and mineralocorticoid receptor, in COS-7 cells cotransfected with HAP1 and each receptor. We found that C-terminal ligand-binding domains of all SHRs had potential for colocalization with HAP1/STBs, whereas only AR and GR were clearly colocalized with HAP1/STBs when each full-length SHR was coexpressed with HAP1. In addition, it appeared that HAP1/STBs did not disrupt GR and AR functions because the receptors on HAP1/STBs maintained nuclear translocation activity in response to their specific ligands. When the cells were treated with a proteasome inhibitor, GR and AR localized outside HAP1/STBs translocated into the nucleus, whereas the receptors colocalized with HAP1/STBs persisted in their colocalization even after treatment with their ligands. Therefore, HAP1/STBs may be involved in cytoplasmic modifications of the nuclear translocation of GR and AR in a ubiquitin-proteasome system.

  13. Fascin, an actin-bundling protein associated with cell motility, is upregulated in hormone receptor negative breastancer

    PubMed Central

    Grothey, A; Hashizume, R; Sahin, A A; McCrea, P D

    2000-01-01

    Loss of hormone receptor (HR) status in breast carcinomas is associated with increased tumour cell motility and invasiveness. In an immunohistological study of 58 primary breast cancers, oestrogen (ER) and progesterone (PR) receptor levels were inversely correlated with the expression of fascin, an actin-bundling protein associated with cell motility (P< 0.0001 and P = 0.0019, respectively). In addition, fascin was preferentially expressed in non-diploid tumours (P = 0.03). In summary, the upregulation of fascin in HR-negative breast cancers may contribute to their more aggressive behaviour. © 2000 Cancer Research Campaign PMID:10970687

  14. Functional analysis of a proline to serine mutation in codon 453 of the thyroid hormone receptor {beta}1 gene

    SciTech Connect

    Ozata, M.; Suzuki, Satoru; Takeda, Teiji

    1995-10-01

    Mutations in the gene encoding human thyroid hormone receptor {beta}(hTR{beta}) have been associated with generalized resistance to thyroid hormone (GRTH). This disorder is associated with significant behavoral abnormalities. We examined the hTR{beta} gene in a family with members who manifest inappropriately normal TSH, elevated free T{sub 4}, and free and total T{sub 3}. Sequence analysis showed a cytosine to thymine transition at nucleotide 1642 in one allele of the index patient`s genomic DNA. This altered proline to serine at codon 453. The resulting mutant receptor when expressed in vitro bound DNA with high affinity, but the T{sub 3} affinity of the receptor was impaired. The mutant TR demonstrated a dominant negative effect when cotransfected with two isoforms of wild-type receptor and also in the presence of TR variant {alpha}2 in COS-1 cells. Mutations of codon 453 occur more frequently than at other sites, and four different amino acid substitutions have been reported. Significant differences in phenotype occur among affected individuals, varying from normality to moderately severe GRTH. There is no clear correlation between K{sub a} or in vitro function of the mutant receptor, and phenotype. This study extends the association between GRTH and illness, and indicates that early diagnosis and counseling are needed in families with TR{beta}1 abnormalities. 34 refs., 5 figs., 2 tabs.

  15. Expression of gonadotropin-releasing hormone receptor and effect of gonadotropin-releasing hormone analogue on proliferation of cultured gastric smooth muscle cells of rats

    PubMed Central

    Chen, Lei; He, Hong-Xuan; Sun, Xu-De; Zhao, Jing; Liu, Li-Hong; Huang, Wei-Quan; Zhang, Rong-Qing

    2004-01-01

    AIM: To investigate the expression of gonadotropin-releasing hormone (GnRH) receptor and the effects of GnRH analog (alarelin) on proliferation of cultured gastric smooth muscle cells (GSMC) of rats. METHODS: Immunohistochemical ABC methods and in situ hybridization methods were used to dectect protein and mRNA expression of GnRH receptor in GSMC, respectively. Techniques of cell culture, OD value of MTT test, measure of 3H-TdR incorporation, average fluorescent values of proliferating cell nuclear antigen (PCNA) and flow cytometric DNA analysis were used in the experiment. RESULTS: The cultured GSMC of rats showed immunoreactivity for GnRH receptor; positive staining was located in cytoplasm. GnRH receptor mRNA hybridized signals were also detected in cytoplasm. When alarelin (10-9, 10-7, 10-5 mol/L) was administered into the medium and incubated for 24 h, OD value of MTT, 3H-TdR incorporation and average fluorescent values of PCNA all decreased significantly as compared with the control group (P < 0.05). The maximum inhibitory effect on cell proliferation was achieved a concentration of 10-5 mol/L and it acted in a dose-dependent manner. Flow cytometric DNA analysis revealed that alarelin could significantly enhance ratio of G1 phase and decrease ratio of S phase of GSMC of rats (P < 0.05).The maximum inhibitory effect on ratio of S phase was at the concentration of 10-5 mol/L and also acted in a dose-dependent manner. CONCLUSION: Our data suggest that GnRH receptor can be expressed by GSMC of rats. GnRH analogue can directly inhibit proliferation and DNA synthesis of rat GSMC through GnRH receptors. PMID:15188505

  16. Demonstration of the insulin receptor in vivo in rabbits and its possible role as a reservoir for the plasma hormone.

    PubMed Central

    Zeleznik, A J; Roth, J

    1978-01-01

    Based on studies of the interaction of insulin with its receptors in vitro, we calculated that a receptor compartment should be measurable directly in vivo. For this purpose, rabbits were injected intravenously with a labeled insulin that has low affinity for receptors in combination with a radioiodinated insulin that has high affinity for receptors. Plasma concentrations of labeled insulins were measured at selected intervals after injection. Apparent volumes of distribution were calculated by extrapolation of plasma distribution were calculated by extrapolation of plasma disappearance curves; high affinity insulins consistently distributed into spaces that were two-three times greater than those of the low affinity insulins. Injections of unlabeled pork insulin before tracer insulins decreased the distribution space of the high affinity insulin in a dose-dependent manner while having little or no effect on the distribution space of the low affinity labeled insulin. When unlabeled insulin was injected after the tracer insulins, there was an immediate rise in the plasma concentration of the high affinity insulin with only a slight change in the plasma concentration of the low affinity insulin. These results demonstrate that high affinity insulins distribute into a body compartment which has many properties of the insulin receptor previously studied in vitro. This receptor compartment: (a) recognizes insulins based on their biological potencies; (b) is saturated by elevated concentrations of insulin; and (c) insulin bound to receptors is in equilibrium with free hormone in plasma. Further, the bound to free ratios for hormone, calculated from these data, suggest that in vivo greater than 50% of the extrapancreatic insulin is bound to receptors during normal physiological states. PMID:659598

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

    PubMed

    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.

  18. Expression and hormonal regulation of membrane progesterone receptors in human astrocytoma cells.

    PubMed

    Valadez-Cosmes, Paulina; Germán-Castelán, Liliana; González-Arenas, Aliesha; Velasco-Velázquez, Marco A; Hansberg-Pastor, Valeria; Camacho-Arroyo, Ignacio

    2015-11-01

    Progesterone (P) participates in the regulation of the growth of several tumors, including astrocytomas, the most common and malignant human brain tumors. It has been reported that P induces astrocytomas growth in part by its interaction with its intracellular receptors (PR). Recently, it has been reported that membrane progesterone receptors (mPRs) are expressed in ovarian and breast cancer cells, and that P could exert some actions through these receptors, however, it is unknown whether mPRs are expressed in astrocytomas. In this work, U251 and U87 cell lines derived from human astrocytomas grade IV were used to study the expression, localization and hormonal regulation of three mPRs subtypes. Using RT-qPCR and Western blot techniques, we found that mPRα and mPRβ are clearly expressed at mRNA and protein levels in astrocytoma cells whereas mPRγ was barely expressed in these cells. Immunofluorescence staining showed that mPRα and mPRβ were mainly located in the cell surface. Flow cytometry assays demonstrated that in U251 and U87 cells, mPRβ is expressed by a higher percentage of both permeabilized and non-permeabilized cells as compared with mPRα. The percentage of cells expressing mPRγ was very low. P and estradiol (E) (10, 100 nM and 1 μM) decreased mPRα protein content at 12 h. In contrast, both P (100 nM and 1 μM) and E (10 and 100 nM) increased mPRβ content. Finally, by in silico analysis, we identified that mPRα, mPRβ and mPRγ promoters contain several progesterone and estrogen response elements. Our results indicate that mPRs are expressed in human astrocytoma cells, exhibiting a differential regulation by E and P. These data suggest that some P actions in astrocytoma cells may be mediated by mPRs. PMID:26275946

  19. Modulation of primary cilia length by melanin-concentrating hormone receptor 1.

    PubMed

    Hamamoto, Akie; Yamato, Shogo; Katoh, Yohei; Nakayama, Kazuhisa; Yoshimura, Kentaro; Takeda, Sen; Kobayashi, Yuki; Saito, Yumiko

    2016-06-01

    Melanin-concentrating hormone (MCH) receptor 1 (MCHR1) is a class A G-protein-coupled receptor (GPCR). The MCH-MCHR1 system has been implicated in the regulation of feeding, emotional processing, and sleep in rodents. Recent work revealed that MCHR1 is selectively expressed in neuronal primary cilia of the central nervous system. Cilia have various chemosensory functions in many types of cell, and ciliary dysfunction is associated with ciliopathies such as polycystic kidney disease and obesity. Although dynamic modulation of neuronal cilia length is observed in obese mice, the functional interaction of neuronal ciliary GPCR and its endogenous ligand has not yet been elucidated. We report here that MCH treatment significantly reduced cilia length in hTERT-RPE1 cells (hRPE1 cells) transfected with MCHR1. Quantitative analyses indicated that MCH-induced cilia shortening progressed in a dose-dependent manner with an EC50 lower than 1nM when cells were treated for 6h. Although the assembly and disassembly of primary cilia are tightly coupled to the cell cycle, cell cycle reentry was not a determinant of MCH-induced cilia shortening. We confirmed that MCH elicited receptor internalization, Ca(2+) mobilization, ERK and Akt phosphorylation, and inhibition of cyclic AMP accumulation in MCHR1-expressing hRPE1 cells. Among these diverse pathways, we revealed that Gi/o-dependent Akt phosphorylation was an important component in the initial stage of MCH-induced cilia length shortening. Furthermore, induction of fewer cilia by Kif3A siRNA treatment significantly decreased the MCH-mediated phosphorylation of Akt, indicating the functional importance of the MCHR1-Akt pathway in primary cilia. Taken together, the present data suggest that the MCH-MCHR1 axis may modulate the sensitivity of cells to external environments by controlling the cilia length. Therefore, further characterization of MCHR1 as a ciliary GPCR will provide a potential molecular mechanism to link cilia length

  20. The CB1 receptor mediates the peripheral effects of ghrelin on AMPK activity but not on growth hormone release.

    PubMed

    Kola, Blerina; Wittman, Gábor; Bodnár, Ibolya; Amin, Faisal; Lim, Chung Thong; Oláh, Márk; Christ-Crain, Mirjam; Lolli, Francesca; van Thuijl, Hinke; Leontiou, Chrysanthia A; Füzesi, Tamás; Dalino, Paolo; Isidori, Andrea M; Harvey-White, Judith; Kunos, George; Nagy, György M; Grossman, Ashley B; Fekete, Csaba; Korbonits, Márta

    2013-12-01

    This study aimed to investigate whether the growth hormone release and metabolic effects of ghrelin on AMPK activity of peripheral tissues are mediated by cannabinoid receptor type 1 (CB1) and the central nervous system. CB1-knockout (KO) and/or wild-type mice were injected peripherally or intracerebroventricularly with ghrelin and CB1 antagonist rimonabant to study tissue AMPK activity and gene expression (transcription factors SREBP1c, transmembrane protein FAS, enzyme PEPCK, and protein HSL). Growth hormone levels were studied both in vivo and in vitro. Peripherally administered ghrelin in liver, heart, and adipose tissue AMPK activity cannot be observed in CB1-KO or CB1 antagonist-treated mice. Intracerebroventricular ghrelin treatment can influence peripheral AMPK activity. This effect is abolished in CB1-KO mice and by intracerebroventricular rimonabant treatment, suggesting that central CB1 receptors also participate in the signaling pathway that mediates the effects of ghrelin on peripheral tissues. Interestingly, in vivo or in vitro growth hormone release is intact in response to ghrelin in CB1-KO animals. Our data suggest that the metabolic effects of ghrelin on AMPK in peripheral tissues are abolished by the lack of functional CB1 receptor via direct peripheral effect and partially through the central nervous system, thus supporting the existence of a possible ghrelin-cannabinoid-CB1-AMPK pathway.

  1. PCB153 and p,p'-DDE disorder thyroid hormones via thyroglobulin, deiodinase 2, transthyretin, hepatic enzymes and receptors.

    PubMed

    Liu, Changjiang; Ha, Mei; Li, Lianbing; Yang, Kedi

    2014-10-01

    Polychlorinated biphenyls (PCBs) and DDT are widespread environmental persistent organic pollutants that have various adverse effects on reproduction, development and endocrine function. In order to elucidate effects of PCBs and DDT on thyroid hormone homeostasis, Sprague-Dawley rats were dosed with PCB153 and p,p'-DDE intraperitoneally (ip) for five consecutive days and sacrificed within 24 h after the last dose. Results indicated that after combined exposure to PCB153 and p,p'-DDE, total thyroxine , free thyroxine, total triiodothyronine, and thyroid-stimulating hormone in serum were decreased, whereas free triiodothyronine and thyrotropin-releasing hormone were not affected. Thyroglobulin and transthyretin levels in serum were significantly reduced. mRNA expression of deiodinases 2 (D2) was also suppressed, while D1 and D3 levels were not significantly influenced after combined exposure. PCB153 and p,p'-DDE induced hepatic enzymes, UDPGTs, CYP1A1, CYP2B1, and CYP3A1 mRNA expressions being significantly elevated. Moreover, TRα1, TRβ1, and TRHr expressions in the hypothalamus displayed increasing trends after combined exposure to PCB153 and p,p'-DDE. Taken together, observed results indicate that PCB153 and p,p'-DDE could disorder thyroid hormone homeostasis via thyroglobulin, deiodinase 2, transthyretin, hepatic enzymes, and hormone receptors. PMID:24878560

  2. Expression of the putative gonadotropin-inhibitory hormone receptor, NPFFR1, in the anterior pituitary gland of the gilt is affected by age and sexual maturation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gonadotropin-inhibitory hormone (GnIH) purportedly suppresses secretion of luteinizing hormone (LH) by acting through a G-protein coupled receptor (NPFFR1) in the anterior pituitary gland and hypothalamus. The objective of these studies was to determine if expression of mRNA for NPFFR1 in the reprod...

  3. Antidepressant/anxiolytic potential and adverse effect liabilities of melanin-concentrating hormone receptor 1 antagonists in animal models.

    PubMed

    Chaki, Shigeyuki; Shimazaki, Toshiharu; Nishiguchi, Mariko; Funakoshi, Takeo; Iijima, Michihiko; Ito, Akie; Kanuma, Kosuke; Sekiguchi, Yoshinori

    2015-08-01

    Melanin-concentrating hormone receptor 1 (MCH1 receptor) is known to be involved in the control of mood and stress, in addition to the regulation of feeding. Here, we report further evidence that the blockade of the MCH1 receptor exhibits antidepressant and anxiolytic-like effects in a variety of animal models using TASP0382650 and TASP0489838, newly synthesized MCH1 receptor antagonists, with different scaffolds. Both TASP0382650 and TASP0489838 exhibited high affinities for human MCH1 receptor with IC50 values of 7.13 and 3.80nM, respectively. Both compounds showed potent antagonist activities at the MCH1 receptor, as assessed using MCH-increased [(35)S]GTPγS binding to human MCH1 receptor and an MCH-induced [Ca(2+)]i assay in rat MCH1 receptor expressing cells. In contrast, neither TASP0382650 nor TASP0489838 showed an affinity for the MCH2 receptor, another MCH receptor subtype. The oral administration of TASP0382650 or TASP0489838 significantly reduced the immobility time during the forced swimming test in rats, and reduced hyperemotionality induced by an olfactory bulbectomy, both of which are indicative of an antidepressant-like potential. In the olfactory bulbectomy model, the antidepressant effect of TASP0382650 appeared following a single administration, suggesting a faster onset of action, compared with current medications. Moreover, both TASP0382650 and TASP0489838 exhibited anxiolytic effects in several animal models of anxiety. In contrast, both TASP0382650 and TASP0489838 did not affect spontaneous locomotor activity, motor function, spatial memory during the Morris water maze task, or the convulsion threshold to pentylenetetrazole. These findings provide additional evidence that the blockade of the MCH1 receptor exhibits antidepressant- and anxiolytic activities with no adverse effects in experimental animal models.

  4. Activators of the nuclear hormone receptors PPARalpha and FXR accelerate the development of the fetal epidermal permeability barrier.

    PubMed Central

    Hanley, K; Jiang, Y; Crumrine, D; Bass, N M; Appel, R; Elias, P M; Williams, M L; Feingold, K R

    1997-01-01

    Members of the superfamily of nuclear hormone receptors which are obligate heterodimeric partners of the retinoid X receptor may be important in epidermal development. Here, we examined the effects of activators of the receptors for vitamin D3 and retinoids, and of the peroxisome proliferator activated receptors (PPARs) and the farnesoid X-activated receptor (FXR), on the development of the fetal epidermal barrier in vitro. Skin explants from gestational day 17 rats (term is 22 d) are unstratified and lack a stratum corneum (SC). After incubation in hormone-free media for 3-4 d, a multilayered SC replete with mature lamellar membranes in the interstices and a functionally competent barrier appear. 9-cis or all-trans retinoic acid, 1,25 dihydroxyvitamin D3, or the PPARgamma ligands prostaglandin J2 or troglitazone did not affect the development of barrier function or epidermal morphology. In contrast, activators of the PPARalpha, oleic acid, linoleic acid, and clofibrate, accelerated epidermal development, resulting in mature lamellar membranes, a multilayered SC, and a competent barrier after 2 d of incubation. The FXR activators, all-trans farnesol and juvenile hormone III, also accelerated epidermal barrier development. Activities of beta-glucocerebrosidase and steroid sulfatase, enzymes previously linked to barrier maturation, also increased after treatment with PPARalpha and FXR activators. In contrast, isoprenoids, such as nerolidol, cis-farnesol, or geranylgeraniol, or metabolites in the cholesterol pathway, such as mevalonate, squalene, or 25-hydroxycholesterol, did not alter barrier development. Finally, additive effects were observed in explants incubated with clofibrate and farnesol together in suboptimal concentrations which alone did not affect barrier development. These data indicate a putative physiologic role for PPARalpha and FXR in epidermal barrier development. PMID:9239419

  5. Combined effects of levonorgestrel and quinestrol on reproductive hormone levels and receptor expression in females of the Mongolian gerbil (Meriones unguiculatus).

    PubMed

    Lv, Xiaohui; Shi, Dazhao

    2012-01-01

    The effects of treatment with a combination of levonorgestrel and quinestrol (EP-1; ratio of 2:1) on reproductive hormone levels and the expression of their receptors in female Mongolian gerbils were examined. We show that serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) decreased, whereas serum estradiol (E2) and progesterone (P4) increased after EP-1 treatment. EP1 down-regulated mRNA expression of the follicle-stimulating hormone receptor (FSHR) and the estrogen receptor (ER) βin the ovary. EP-1 up-regulated the mRNA expression of the luteinizing hormone receptor (LHR) and the progesterone receptor (PR) in the ovary as well as ERα and PR in the uterus of Mongolian gerbils. The effects were time-dependent and dose-dependent. EP-1 had no obvious effects on ERα mRNA expression in the ovary. The current study demonstrates that the effect of EP-1 on the expression of ER subtypes is tissue-specific in Mongolian gerbils. EP-1 disrupted the reproductive endocrinology of the Mongolian gerbil. These findings suggest that the effects of EP-1 on reproductive hormone levels and their receptor expression in Mongolian gerbils may be the result of synergistic actions of levonorgestrel and quinestrol, with quinestrol playing the major role. PMID:22233494

  6. Structural Basis for Parathyroid Hormone-related Protein Binding to the Parathyroid Hormone Receptor and Design of Conformation-selective Peptides

    SciTech Connect

    Pioszak, Augen A.; Parker, Naomi R.; Gardella, Thomas J.; Xu, H. Eric

    2009-12-01

    Parathyroid hormone (PTH) and PTH-related protein (PTHrP) are two related peptides that control calcium/phosphate homeostasis and bone development, respectively, through activation of the PTH/PTHrP receptor (PTH1R), a class B G protein-coupled receptor. Both peptides hold clinical interest for their capacities to stimulate bone formation. PTH and PTHrP display different selectivity for two distinct PTH1R conformations, but how their binding to the receptor differs is unclear. The high resolution crystal structure of PTHrP bound to the extracellular domain (ECD) of PTH1R reveals that PTHrP binds as an amphipathic {alpha}-helix to the same hydrophobic groove in the ECD as occupied by PTH, but in contrast to a straight, continuous PTH helix, the PTHrP helix is gently curved and C-terminally 'unwound.' The receptor accommodates the altered binding modes by shifting the side chain conformations of two residues within the binding groove: Leu-41 and Ile-115, the former acting as a rotamer toggle switch to accommodate PTH/PTHrP sequence divergence, and the latter adapting to the PTHrP curvature. Binding studies performed with PTH/PTHrP hybrid ligands having reciprocal exchanges of residues involved in different contacts confirmed functional consequences for the altered interactions and enabled the design of altered PTH and PTHrP peptides that adopt the ECD-binding mode of the opposite peptide. Hybrid peptides that bound the ECD poorly were selective for the G protein-coupled PTH1R conformation. These results establish a molecular model for better understanding of how two biologically distinct ligands can act through a single receptor and provide a template for designing better PTH/PTHrP therapeutics.

  7. Hair-cycle-dependent expression of parathyroid hormone-related protein and its type I receptor: evidence for regulation at the anagen to catagen transition.

    PubMed

    Cho, Yong Mee; Woodard, Grant L; Dunbar, Maureen; Gocken, Todd; Jimènez, Juan A; Foley, John

    2003-05-01

    The humoral hypercalcemia factor parathyroid hormone-related protein is a paracrine-signaling molecule that regulates the development of several organ systems, including the skin. In pathologic circumstances such as hypercalcemia and in development, parathyroid hormone-related protein signaling appears to be mediated by the type I parathyroid hormone/parathyroid hormone-related protein receptor. In order to clarify the role of the ligand and receptor pair in cutaneous biology, gene expression was monitored in a series of murine skin samples ranging from embryonic day 14 to 2 y with in situ hybridization and RNase protection. In all samples, high levels of parathyroid hormone-related protein transcripts were exclusively expressed in the developing and adult hair follicle but were not observed in the interfollicular epidermis. In the adult, parathyroid hormone-related protein mRNA expression was dynamically regulated as a function of the murine hair cycle in a way similar to other signaling molecules that regulate the anagen to catagen transition. PTH receptor transcripts were abundantly expressed in the developing dermis. In the adult skin, PTH receptor mRNA was markedly reduced, but again demonstrated hair-cycle-dependent expression. The dorsal skin of the keratin 14-parathyroid hormone-related protein mouse was used to evaluate the impact of overexpression of the peptide on the murine hair cycle. All types of hair were 30-40% shorter in adult keratin 14-parathyroid hormone-related protein mice as compared with wild-type littermates. This appeared to result from a premature entry into the catagen phase of the hair cycle. Finally, the relationship between parathyroid hormone-related protein signaling and other growth factors that regulate the hair cycle was examined by cross-breeding experiments employing keratin 14-parathyroid hormone-related protein mice and fibroblast growth factor-5-knockout mice. It appears that parathyroid hormone-related protein and

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

    PubMed

    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.

  9. Tolerability of Therapies Recommended for the Treatment of Hormone Receptor-Positive Locally Advanced or Metastatic Breast Cancer.

    PubMed

    Ohno, Shinji

    2016-08-01

    For women with hormone receptor-positive advanced breast cancer, endocrine therapies, including the selective estrogen receptor modulator tamoxifen, the aromatase inhibitors anastrozole, letrozole, and exemestane, and the selective estrogen receptor degrader fulvestrant, are recommended in clinical guidelines. The addition of targeted agents such as everolimus or palbociclib to aromatase inhibitors are also recommended as treatment options. Chemotherapy remains an option, although clinical guidelines have recommended these agents be reserved for patients with immediately life-threatening disease or if resistance to endocrine therapy is known or suspected. The present review has consolidated the tolerability profiles of the agents approved for use in the treatment of hormone receptor-positive advanced or metastatic breast cancer based on phase III registration trial data. Endocrine therapies are generally well tolerated, although the addition of targeted therapies to aromatase inhibitors or fulvestrant appears to increase the proportion of patients experiencing adverse events, and palbociclib and chemotherapy appear to be more closely associated with serious adverse events, including neutropenia. PMID:27151773

  10. Association of mammographic density with hormone receptors in invasive breast cancers: results from a case-only study.

    PubMed

    Heusinger, Katharina; Jud, Sebastian M; Häberle, Lothar; Hack, Carolin C; Adamietz, Boris R; Meier-Meitinger, Martina; Lux, Michael P; Wittenberg, Thomas; Wagner, Florian; Loehberg, Christian R; Uder, Michael; Hartmann, Arndt; Schulz-Wendtland, Rüdiger; Beckmann, Matthias W; Fasching, Peter A

    2012-12-01

    For many breast cancer (BC) risk factors, there is growing evidence concerning molecular subtypes for which the risk factor is specific. With regard to mammographic density (MD), there are inconsistent data concerning its association with estrogen receptor (ER) and progesterone receptor (PR) expression. The aim of our study was to analyze the association between ER and PR expression and MD. In our case-only study, data on BC risk factors, hormone receptor expression and MD were available for 2,410 patients with incident BC. MD was assessed as percent MD (PMD) using a semiautomated method by two readers for every patient. The association of ER/PR and PMD was studied with multifactorial analyses of covariance with PMD as the target variable and including well-known factors that are also associated with MD, such as age, parity, use of hormone replacement therapy, and body mass index (BMI). In addition to the commonly known associations between PMD and age, parity, BMI and hormone replacement therapy, a significant inverse association was found between PMD and ER expression levels. Patients with ER-negative tumors had an average PMD of 38%, whereas patients with high ER expression had a PMD of 35%. A statistical trend toward a positive association between PMD and PR expression was also seen. PMD appears to be inversely associated with ER expression and may correlate positively with PR expression. These effects were independent of other risk factors such as age, BMI, parity, and hormone replacement therapy, possibly suggesting other pathways that mediate this effect.

  11. Biological regulation of receptor-hormone complex concentrations in relation to dose-response assessments for endocrine-active compounds.

    PubMed

    Andersen, M E; Barton, H A

    1999-03-01

    Some endocrine-active compounds (EACs) act as agonists or antagonists of specific hormones and may interfere with cellular control processes that regulate gene transcription. Many mechanisms controlling gene expression are universal to organisms ranging from unicellular bacteria to more complex plants and animals. One mechanism, coordinated control of batteries of gene products, is critical in adaptation of bacteria to new environments and for development and tissue differentiation in multi-cellular organisms. To coordinately activate sets of genes, all living organisms have devised molecular modules to permit transitions, or switching, between different functional states over a small range of hormone concentration, and other modules to stabilize the new state through homeostatic interactions. Both switching and homeostasis are regulated by controlling concentrations of hormone-receptor complexes. Molecular control processes for switching and homeostasis are inherently nonlinear and often utilize autoregulatory feedback loops. Among the biological processes contributing to switching phenomena are receptor autoinduction, induction of enzymes for ligand synthesis, mRNA stabilization/activation, and receptor polymerization. This paper discusses a variety of molecular switches found in animal species, devises simple quantitative models illustrating roles of specific molecular interactions in creating switching modules, and outlines the impact of these switching processes and other feedback loops for risk assessments with EACs. Quantitative simulation modeling of these switching mechanisms made it apparent that highly nonlinear dose-response curves for hormones and EACs readily arise from interactions of several linear processes acting in concert on a common control point. These nonlinear mechanisms involve amplification of response, rather than multimeric molecular interactions as in conventional Hill relationships. PMID:10330682

  12. Hormonal regulation of delta opioid receptor immunoreactivity in interneurons and pyramidal cells in the rat hippocampus

    PubMed Central

    Williams, Tanya J.; Torres-Reveron, Annelyn; Chapleau, Jeanette D.; Milner, Teresa A.

    2011-01-01

    Clinical and preclinical studies indicate that women and men differ in relapse vulnerability to drug-seeking behavior during abstinence periods. As relapse is frequently triggered by exposure of the recovered addict to objects previously associated with drug use and the formation of these associations requires memory systems engaged by the hippocampal formation (HF), studies exploring ovarian hormone modulation of hippocampal function are warranted. Previous studies revealed that ovarian steroids alter endogenous opioid peptide levels and trafficking of mu opioid receptors in the HF, suggesting cooperative interaction between opioids and estrogens in modulating hippocampal excitability. However, whether ovarian steroids affect the levels or trafficking of delta opioid receptors (DORs) in the HF is unknown. Here, hippocampal sections of adult male and normal cycling female Sprague-Dawley rats were processed for quantitative immunoperoxidase light microscopy and dual label fluorescence or immunoelectron microscopy using antisera directed against the DOR and neuropeptide Y (NPY). Consistent with previous studies in males, DOR-immunoreactivity (-ir) localized to select interneurons and principal cells in the female HF. In comparison to males, females, regardless of estrous cycle phase, show reduced DOR-ir in the granule cell layer of the dentate gyrus and proestrus (high estrogen) females, in particular, display reduced DOR-ir in the CA1 pyramidal cell layer. Ultrastructural analysis of DOR-labeled profiles in CA1 revealed that while females generally show fewer DORs in the distal apical dendrites of pyramidal cells, proestrus females, in particular, exhibit DOR internalization and trafficking towards the soma. Dual label studies revealed that DORs are found in NPY-labeled interneurons in the hilus, CA3, and CA1. While DOR colocalization frequency in NPY-labeled neuron somata was similar between animals in the hilus, proestrus females had fewer NPY-labeled neurons that

  13. Molecular cloning, expression, and signaling pathway of four melanin-concentrating hormone receptors from Xenopus tropicalis.

    PubMed

    Kobayashi, Yuki; Hamamoto, Akie; Hirayama, Tomo; Saito, Yumiko

    2015-02-01

    Melanin-concentrating hormone (MCH) mainly regulates feeding in mammals and pigmentation in teleosts. It acts via two G-protein-coupled receptors, MCH receptor 1 (MCHR1) and MCHR2. Although many studies exploring the MCH system in teleosts and mammals have been carried out, studies on other organisms are limited. In this study, we cloned and characterized four MCHR subtypes from the diploid species Xenopus tropicalis (X-MCHRs; X-MCHR1a, R1b, R2a, and R2b). According to a phylogenetic tree of the X-MCHRs, X-MCHR1a and R2a are close to mammalian MCHRs, while X-MCHR1b and R2b are close to teleostean MCHRs. We previously reported that the G-protein coupling capacity of the MCHR subtypes differed between mammals (R1: Gαi/o and Gαq; R2: Gαq) and teleosts (R1: Gαq; R2: Gαi/o and Gαq) in mammalian cell-based assays. By using Ca(2+) mobilization assays with pertussis toxin in CHO dhfr(-) cells, we found that X-MCHR1a promiscuously coupled to both Gαi/o and Gαq, while X-MCHR1b and R2a exclusively coupled to Gαq. However, no Ca(2+) influx was detected in cells transfected with X-MCHR2b. Reverse transcription-PCR showed that the X-MCHR mRNAs were expressed in various tissues. In particular, both X-MCHR1b and R2b were exclusively found in melanophores of the dorsal skin. In skin pigment migration assays, melanophores were weakly aggregated at low concentrations but dispersed at high concentrations of MCH, suggesting possible interactions between X-MCHR1b and R2b for the regulation of body color. These findings demonstrate that X. tropicalis has four characteristic MCHRs and will be useful for elucidating the nature of MCHR evolution among vertebrates.

  14. Hormonal regulation of delta opioid receptor immunoreactivity in interneurons and pyramidal cells in the rat hippocampus.

    PubMed

    Williams, Tanya J; Torres-Reveron, Annelyn; Chapleau, Jeanette D; Milner, Teresa A

    2011-02-01

    Clinical and preclinical studies indicate that women and men differ in relapse vulnerability to drug-seeking behavior during abstinence periods. As relapse is frequently triggered by exposure of the recovered addict to objects previously associated with drug use and the formation of these associations requires memory systems engaged by the hippocampal formation (HF), studies exploring ovarian hormone modulation of hippocampal function are warranted. Previous studies revealed that ovarian steroids alter endogenous opioid peptide levels and trafficking of mu opioid receptors in the HF, suggesting cooperative interaction between opioids and estrogens in modulating hippocampal excitability. However, whether ovarian steroids affect the levels or trafficking of delta opioid receptors (DORs) in the HF is unknown. Here, hippocampal sections of adult male and normal cycling female Sprague-Dawley rats were processed for quantitative immunoperoxidase light microscopy and dual label fluorescence or immunoelectron microscopy using antisera directed against the DOR and neuropeptide Y (NPY). Consistent with previous studies in males, DOR-immunoreactivity (-ir) localized to select interneurons and principal cells in the female HF. In comparison to males, females, regardless of estrous cycle phase, show reduced DOR-ir in the granule cell layer of the dentate gyrus and proestrus (high estrogen) females, in particular, display reduced DOR-ir in the CA1 pyramidal cell layer. Ultrastructural analysis of DOR-labeled profiles in CA1 revealed that while females generally show fewer DORs in the distal apical dendrites of pyramidal cells, proestrus females, in particular, exhibit DOR internalization and trafficking towards the soma. Dual label studies revealed that DORs are found in NPY-labeled interneurons in the hilus, CA3, and CA1. While DOR colocalization frequency in NPY-labeled neuron somata was similar between animals in the hilus, proestrus females had fewer NPY-labeled neurons that

  15. Migraine and possible etiologic heterogeneity for hormone-receptor-negative breast cancer.

    PubMed

    Shi, Min; DeRoo, Lisa A; Sandler, Dale P; Weinberg, Clarice R

    2015-01-01

    Migraine headache is often timed with the menstrual cycle. Some studies have reported reduced risk of breast cancer in migraineurs but most of those did not distinguish menstrually-related from non-menstrually-related migraine. To examine the possible associations between breast cancer and migraine overall and between cancer subcategories and the two migraine subtypes, we used a cohort study of 50,884 women whose sister had breast cancer and a sister-matched case-control study including 1,418 young-onset (<50 years) breast cancer cases. We analyzed the two studies individually and also in tandem via a hybrid Cox model, examining subcategories of breast cancer in relation to menstrually-related and non-menstrually-related migraine. History of migraine was not associated with breast cancer overall. Migraine showed an inverse association with ductal carcinoma in situ (HR = 0.77; 95% CI (0.62,0.96)). Also, women with non-menstrually-related migraine had increased risk (HR = 1.30, 95% CI (0.93,1.81)) while women with menstrually-related migraine had decreased risk (HR = 0.63, 95% CI (0.42,0.96)) of hormone-receptor-negative (ER-/PR-) cancer, with a significant contrast in estimated effects (P = 0.005). While replication of these subset-based findings will be needed, effect specificity could suggest that while migraine has little overall association with breast cancer, menstrual migraine may be associated with reduced risk of ER-/PR- breast cancer.

  16. Parathyroid hormone induces the Nrna family of nuclear orphan receptors in vivo

    SciTech Connect

    Pirih, Flavia Q. . E-mail: fqpirih@ucla.edu; Aghaloo, Tara L. . E-mail: taghaloo@ucla.edu; Bezouglaia, Olga . E-mail: obezougl@ucla.edu; Nervina, Jeanne M. . E-mail: jnervina@ucla.edu; Tetradis, Sotirios; E-mail: sotirist@dent.ucla.edu

    2005-07-01

    Parathyroid hormone (PTH) has both anabolic and catabolic effects on bone metabolism, although the molecular mechanisms mediating these effects are largely unknown. Among the transcription factors induced by Pth in osteoblasts are the nerve growth factor-inducible factor B (NR4A; NGFI-B) family of orphan nuclear receptors: Nurr1, Nur77, and NOR-1. PTH induces NR4A members through the cAMP-protein kinase A (PKA) pathway in vitro. We report here that PTH rapidly and transiently induced expression of all three NR4A genes in PTH-target tissues in vivo. In calvaria, long bones, and kidneys, NR4A induction was maximal 0.5-1 h after a single intraperitoneal (i.p.) injection of 80 {mu}g/kg PTH. Nur77 demonstrated the highest expression, followed, in order, by Nurr1 and NOR-1. In calvaria and long bone, PTH-induced expression of each NR4A gene was detectable at 10 {mu}g/kg i.p. with maximum induction at 40-80 {mu}g/kg. PTH (3-34) did not induce NR4A mRNA levels in calvaria, long bone, and kidney in vivo, confirming our in vitro results that NR4A genes are induced primarily through the cAMP-PKA pathway. The magnitude of PTH-induced NR4A expression was comparable in vivo and in vitro. However, NR4A mRNA levels peaked and returned to baseline faster in vivo. Both in vivo and in vitro, PTH induced NR4A pre-mRNA levels suggesting that induction of these genes is, at least in part, through activation of mRNA synthesis. The in vivo induction of the NR4A family members by PTH suggests their involvement in, at least some, PTH-induced changes in bone metabolism.

  17. Transient congenital hypothyroidism due to thyroid-stimulating hormone receptor blocking antibodies: a case series.

    PubMed

    Evans, Carol; Gregory, John W; Barton, John; Bidder, Christopher; Gibbs, John; Pryce, Rebekah; Al-Muzaffar, Iyad; Ludgate, Marian; Warner, Justin; John, Rhys; Moat, Stuart J

    2011-07-01

    We describe seven infants with transient congenital hypothyroidism (CH) due to maternal thyroid-stimulating hormone receptor (TSH-R) blocking antibodies (TRAb) identified over three decades of newborn screening for CH in Wales, UK that represents a minimum incidence of 1.6% of CH cases. Infants with transient CH due to maternal TRAb presented with a spectrum of clinical and biochemical hypothyroidism. Blood spot TSH concentrations ranged 60.5-332 mIU/L. CH was confirmed by plasma thyroid function tests in all cases (plasma TSH ranged 21-752 mIU/L). The seven infants belonged to five different families. On examination, four infants were clinically hypothyroid. Five infants had a thyroid ultrasound, of which three were abnormal. All infants were treated with thyroxine, which was subsequently withdrawn from three. Following thyroxine withdrawal, one infant resumed normal thyroid function and two developed compensated hypothyroidism. Of the five mothers, two had undiagnosed hypothyroidism and three were receiving thyroxine for longstanding hypothyroidism. Thyroid peroxidase antibody (aTPO) was measured in four and was negative in two, borderline positive in one and strongly positive in another. TRAb was measured in all five women and was strongly positive in all of them. This case series highlights the importance of identifying CH due to TRAb by investigating both the infant and the mother following a raised TSH found on newborn screening. The identification of those infants with transient CH caused by maternal transfer of TRAb is essential for optimizing management during childhood (including potential withdrawal of thyroxine replacement in the longer term) and in any subsequent pregnancy.

  18. Unliganded Thyroid Hormone Receptor α Regulates Developmental Timing via Gene Repression in Xenopus tropicalis

    PubMed Central

    Choi, Jinyoung; Suzuki, Ken-ichi T.; Sakuma, Tetsushi; Shewade, Leena; Yamamoto, Takashi

    2015-01-01

    Thyroid hormone (TH) receptor (TR) expression begins early in development in all vertebrates when circulating TH levels are absent or minimal, yet few developmental roles for unliganded TRs have been established. Unliganded TRs are expected to repress TH-response genes, increase tissue responsivity to TH, and regulate the timing of developmental events. Here we examined the role of unliganded TRα in gene repression and development in Xenopus tropicalis. We used transcription activator-like effector nuclease gene disruption technology to generate founder animals with mutations in the TRα gene and bred them to produce F1 offspring with a normal phenotype and a mutant phenotype, characterized by precocious hind limb development. Offspring with a normal phenotype had zero or one disrupted TRα alleles, and tadpoles with the mutant hind limb phenotype had two truncated TRα alleles with frame shift mutations between the two zinc fingers followed by 40–50 mutant amino acids and then an out-of-frame stop codon. We examined TH-response gene expression and early larval development with and without exogenous TH in F1 offspring. As hypothesized, mutant phenotype tadpoles had increased expression of TH-response genes in the absence of TH and impaired induction of these same genes after exogenous TH treatment, compared with normal phenotype animals. Also, mutant hind limb phenotype animals had reduced hind limb and gill responsivity to exogenous TH. Similar results in methimazole-treated tadpoles showed that increased TH-response gene expression and precocious development were not due to early production of TH. These results indicate that unliganded TRα delays developmental progression by repressing TH-response genes. PMID:25456067

  19. Urocortin 3 modulates social discrimination abilities via corticotropin-releasing hormone receptor type 2.

    PubMed

    Deussing, Jan M; Breu, Johannes; Kühne, Claudia; Kallnik, Magdalena; Bunck, Mirjam; Glasl, Lisa; Yen, Yi-Chun; Schmidt, Mathias V; Zurmühlen, Regine; Vogl, Annette M; Gailus-Durner, Valérie; Fuchs, Helmut; Hölter, Sabine M; Wotjak, Carsten T; Landgraf, Rainer; de Angelis, Martin Hrabé; Holsboer, Florian; Wurst, Wolfgang

    2010-07-01

    Urocortin 3 (UCN3) is strongly expressed in specific nuclei of the rodent brain, at sites distinct from those expressing urocortin 1 and urocortin 2, the other endogenous ligands of corticotropin-releasing hormone receptor type 2 (CRH-R2). To determine the physiological role of UCN3, we generated UCN3-deficient mice, in which the UCN3 open reading frame was replaced by a tau-lacZ reporter gene. By means of this reporter gene, the nucleus parabrachialis and the premammillary nucleus were identified as previously unknown sites of UCN3 expression. Additionally, the introduced reporter gene enabled the visualization of axonal projections of UCN3-expressing neurons from the superior paraolivary nucleus to the inferior colliculus and from the posterodorsal part of the medial amygdala to the principal nucleus of the bed nucleus of the stria terminalis, respectively. The examination of tau-lacZ reporter gene activity throughout the brain underscored a predominant expression of UCN3 in nuclei functionally connected to the accessory olfactory system. Male and female mice were comprehensively phenotyped but none of the applied tests provided indications for a role of UCN3 in the context of hypothalamic-pituitary-adrenocortical axis regulation, anxiety- or depression-related behavior. However, inspired by the prevalent expression throughout the accessory olfactory system, we identified alterations in social discrimination abilities of male and female UCN3 knock-out mice that were also present in male CRH-R2 knock-out mice. In conclusion, our results suggest a novel role for UCN3 and CRH-R2 related to the processing of social cues and to the establishment of social memories.

  20. The growth hormone receptor polymorphism in patients with acromegaly: relationship to BMI and glucose metabolism.

    PubMed

    Turgut, Sebahat; Akın, Fulya; Ayada, Ceylan; Topsakal, Senay; Yerlikaya, Emrah; Turgut, Günfer

    2012-09-01

    The aim of this study was to investigate association between the frequencies of Growth Hormone receptor (d3GHR) gene polymorphisms and some clinical parameters of acromegalic patients. Total of 35 acromegalic patients were enrolled to study. The d3GHR polymorphism was identified by using polymerase chain reaction from peripheral blood samples. The levels of systolic and diastolic blood pressure, BMI, fasting plasma glucose (FPG), Fasting insulin, HOMA-IR, IGF-I, GH, IGFBP3, triglyceride, HDL and LDL cholesterol concentrations were evaluated. The frequencies of d3GHR genotypes were found as follows; 5 (14.3%) subjects had d3/d3, 11 (31.4%) had d3/fl and 19 (54.3%) had fl/fl in patients. The prevalence of the d3 and fl alleles was 30 and 70%, respectively. Systolic blood pressure, fasting insulin and HOMA-IR was found significantly increased in homozygote d3GHR genotype group compared to d3/fl subjects (P < 0.05). In addition, BMI was observed significantly different among three genotypes (P = 0.007) and in the subjects with d3/d3 genotype, BMI was found significantly higher than d3/fl and fl/fl genotypes groups. As well as, no significant difference was found between the d3 and fl alleles group in terms of the clinical parameters except for BMI (P = 0.002). It can be said that the d3GHR gene polymorphism may affect BMI, systolic blood pressure and insulin regulation. At the same time we can say homozygote d3GHR genotype and d3 allele carriers may have more risk than other genotypes for high BMI.

  1. Racial disparities in breast cancer diagnosis and treatment by hormone receptor and HER2 status

    PubMed Central

    Chen, Lu; Li, Christopher I.

    2015-01-01

    Background African American and Hispanic women are more likely to be diagnosed with aggressive forms of breast cancer. Disparities within each subtype of breast cancer have not been well documented. Methods Using data from 18 SEER cancer registries, we identified 102,064 women aged 20 years or older, diagnosed with invasive breast cancer in 2010–2011, and with known stage, hormone receptor (HR) and HER2 status. Associations between race/ethnicity and cancer stage and receipt of guideline concordant treatment were evaluated according to HR/HER2 status. Results Overall, African American and Hispanic women were 30–60% more likely to be diagnosed with stage II–IV breast cancer compared to Non-Hispanic whites. African American women had 40–70% higher risks of stage IV breast cancer across all four subtypes. American Indian/Alaska Native women had a 3.9-fold higher risk of stage IV triple negative breast cancer. African American and Hispanic whites were 30–40% more likely to receive non-guideline concordant treatment for breast cancer overall and across subtypes. Conclusions Women in several racial/ethnic groups are more likely to be diagnosed with more advanced stage breast cancer. African American and American Indian/Alaska native women in particular had the highest risk of being diagnosed with stage IV triple negative breast cancer. African American and Hispanic women were also consistently at higher risk of not receiving guideline concordant treatment across subtypes. Impact These findings provide important characterization of which subtypes of breast cancer racial/ethnic disparities in stage and treatment persist. PMID:26464428

  2. Hepatic growth hormone and glucocorticoid receptor signaling in body growth, steatosis and metabolic liver cancer development.

    PubMed

    Mueller, Kristina M; Themanns, Madeleine; Friedbichler, Katrin; Kornfeld, Jan-Wilhelm; Esterbauer, Harald; Tuckermann, Jan P; Moriggl, Richard

    2012-09-25

    Growth hormone (GH) and glucocorticoids (GCs) are involved in the control of processes that are essential for the maintenance of vital body functions including energy supply and growth control. GH and GCs have been well characterized to regulate systemic energy homeostasis, particular during certain conditions of physical stress. However, dysfunctional signaling in both pathways is linked to various metabolic disorders associated with aberrant carbohydrate and lipid metabolism. In liver, GH-dependent activation of the transcription factor signal transducer and activator of transcription (STAT) 5 controls a variety of physiologic functions within hepatocytes. Similarly, GCs, through activation of the glucocorticoid receptor (GR), influence many important liver functions such as gluconeogenesis. Studies in hepatic Stat5 or GR knockout mice have revealed that they similarly control liver function on their target gene level and indeed, the GR functions often as a cofactor of STAT5 for GH-induced genes. Gene sets, which require physical STAT5-GR interaction, include those controlling body growth and maturation. More recently, it has become evident that impairment of GH-STAT5 signaling in different experimental models correlates with metabolic liver disease, ranging from hepatic steatosis to hepatocellular carcinoma (HCC). While GH-activated STAT5 has a protective role in chronic liver disease, experimental disruption of GC-GR signaling rather seems to ameliorate metabolic disorders under metabolic challenge. In this review, we focus on the current knowledge about hepatic GH-STAT5 and GC-GR signaling in body growth, metabolism, and protection from fatty liver disease and HCC development.

  3. Cardioselective Dominant-negative Thyroid Hormone Receptor (Δ337T) Modulates Myocardial Metabolism and Contractile Dfficiency

    SciTech Connect

    Hyyti, Outi M.; Olson, Aaron; Ge, Ming; Ning, Xue-Han; Buroker, Norman E.; Chung, Youngran; Jue, Thomas; Portman, Michael A.

    2008-06-03

    Dominant- negative thyroid hormone receptors (TRs) show elevated expression relative to ligand-binding TRs during cardiac hypertrophy. We tested the hypothesis that overexpression of a dominant-negative TR alters cardiac metabolism and contractile efficiency (CE). We used mice expressing the cardioselective dominant-negative TRβ1 mutation Δ337T. Isolated working Δ337T hearts and nontransgenic control (Con) hearts were perfused with 13C-labeled free fatty acids (FFA), acetoacetate (ACAC), lactate, and glucose at physiological concentrations for 30 min. 13C NMR spectroscopy and isotopomer analyses were used to determine substrate flux and fractional contributions (Fc) of acetyl-CoA to the citric acid cycle (CAC). Δ337T hearts exhibited rate depression but higher developed pressure and CE, defined as work per oxygen consumption (MV˙ O2). Unlabeled substrate Fc from endogenous sources was higher in Δ337T, but ACAC Fc was lower. Fluxes through CAC, lactate, ACAC, and FFA were reduced in Δ337T. CE and Fc differences were reversed by pacing Δ337T to Con rates, accompanied by an increase in FFA Fc. Δ337T hearts lacked the ability to increase MV˙ O2. Decreases in protein expression for glucose transporter-4 and hexokinase-2 and increases in pyruvate dehydrogenase kinase-2 and -4 suggest that these hearts are unable to increase carbohydrate oxidation in response to stress. These data show that Δ337T alters the metabolic phenotype in murine heart by reducing substrate flux for multiple pathways. Some of these changes are heart rate dependent, indicating that the substrate shift may represent an accommodation to altered contractile protein kinetics, which can be disrupted by pacing stress.

  4. In vitro and in vivo human metabolism of degarelix, a gonadotropin-releasing hormone receptor blocker.

    PubMed

    Sonesson, Anders; Rasmussen, Birgitte Buur

    2013-07-01

    Degarelix is a decapeptide that shows high affinity/selectivity to human gonadotropin-releasing hormone receptors and has been approved for the treatment of advanced prostate cancer in the United States, European Union, and Japan. To investigate the metabolism of degarelix in humans, in vitro metabolism was addressed in liver tissue and in vivo metabolism was studied in plasma and excreta samples collected in clinical studies. In addition, drug transporter interaction potential of degarelix with selected efflux transporters and uptake transporters was studied using in vitro membrane vesicle-based assays and whole cell-based assays. In vitro degradation was observed in fresh hepatocytes; less than 25% of the initial concentration of degarelix remained after incubation at 37°C for 2 hours. One metabolite was detected, representing a truncated nonapeptide of degarelix. The same metabolite was also detected at low concentrations in plasma. The in vivo investigations also showed that degarelix is excreted unchanged via the urine but is undergoing extensive sequential peptidic degradation during its elimination via the hepato-biliary pathway. No unique human metabolites of degarelix were detected in the circulation or in the excreta. Degarelix did not show any interaction with selected efflux transporters and uptake transporters up to concentrations representing 200 times the clinical concentration. Because degarelix does not seem to interact with the cytochrome P450 enzyme system as substrate, inhibitor, or inducer and does not show any interaction with hepatic and renal uptake and efflux transporters, the risk for pharmacokinetic drug-drug interactions with this compound is highly unlikely.

  5. Steroid hormone modulation of cAMP production in response to beta adrenergic receptor stimulation in genital tract myocytes.

    PubMed

    DiGiovanni, L; Austin, R; Phillippe, M

    1992-01-01

    beta-Adrenergic receptor stimulation results in smooth muscle relaxation through activation of adenylyl cyclase and subsequent cyclic AMP (cAMP) production. The present study was performed to evaluate the effects of steroid hormones (i.e. testosterone and hydrocortisone) on beta 2-adrenergic receptors and their signal transduction in the DDT1 MF-2 genital tract myocyte. Radioligand binding studies demonstrated that these two steroid hormones produced a 70 to 80% increase in the density of beta 2-adrenergic receptors in these myocytes. Stimulation of the beta 2-adrenergic receptors with isoproterenol resulted in a significant increase of cAMP in control myocytes; cells treated with testosterone for 24 h demonstrated a comparable response to isoproterenol, whereas hydrocortisone for 24 h resulted in a 50% greater cAMP response. In contrast to the response at 24 h, stimulation of myocytes after testosterone treatment for 48 h resulted in a cAMP response comparable to that seen in response to hydrocortisone at 24 h. Studies performed using theophylline demonstrated similar cAMP responses at 24 h between the control and testosterone-treated myocytes, thereby ruling out the possibility that the delayed increase of the cAMP response after testosterone was caused by stimulation of phosphodiesterase. Direct stimulation with forskolin resulted in greater cAMP production in the testosterone-treated myocytes compared to controls, thereby refuting the possibility that testosterone directly suppresses adenylyl cyclase activity at 24 h. These findings suggest that although both testosterone and hydrocortisone produce a twofold increase in beta 2-adrenergic receptor density in the DDT1 myocytes, beta 2-adrenergic receptors expressed in response to hydrocortisone appear functional at 24 h resulting in increased cAMP production, whereas those expressed in response to testosterone require 48 h to demonstrate increased functional activity.

  6. Developmental expression, differential hormonal regulation and evolution of thyroid and glucocorticoid receptor variants in a marine acanthomorph teleost (Sciaenops ocellatus).

    PubMed

    Applebaum, Scott L; Finn, Roderick Nigel; Faulk, Cynthia K; Joan Holt, G; Scott Nunez, B

    2012-03-01

    Interactions between the thyroid hormone (TH) and corticosteroid (CS) hormone axes are suggested to regulate developmental processes in vertebrates with a larval phase. To investigate this hypothesis, we isolated three nuclear receptors from a larval acanthomorph teleost, the red drum (Sciaenops ocellatus), and established their orthologies as thraa, thrb-L and gra-L using phylogenomic and functional analyses. Functional characterization of the TH receptors in COS-1 cells revealed that Thraa and Thrb-L exhibit dose-dependent transactivation of a luciferase reporter in response to T3, while SoThraa is constitutively active at a low level in the absence of ligand. To test whether interactions between the TH and CS systems occur during development, we initially quantified the in vivo receptor transcript expression levels, and then examined their response to treatment with triiodothyronine (T3) or cortisol. We find that sothraa and sothrb-L are autoregulated in response to exogenous T3 only during early larval development. T3 did not affect sogra-L expression levels, nor did cortisol alter levels of sothraa or sothrb-L at any stage. While differential expression of the receptors in response to non-canonical ligand hormone was not observed under the conditions in this study, the correlation between sothraa and sogra-L transcript abundance during development suggests a coordinated function of the TH and CS systems. By comparing the findings in the present study to earlier investigations, we suggest that the up-regulation of thraa may be a specific feature of metamorphosis in acanthomorph teleosts. PMID:22226731

  7. Ovary ecdysteroidogenic hormone requires a receptor tyrosine kinase to activate egg formation in the mosquito Aedes aegypti

    PubMed Central

    Vogel, Kevin J.; Brown, Mark R.; Strand, Michael R.

    2015-01-01

    Mosquitoes are major disease vectors because most species must feed on blood from a vertebrate host to produce eggs. Blood feeding by the vector mosquito Aedes aegypti triggers the release of two neurohormones, ovary ecdysteroidogenic hormone (OEH) and insulin-like peptides (ILPs), which activate multiple processes required for egg formation. ILPs function by binding to the insulin receptor, which activates downstream components in the canonical insulin signaling pathway. OEH in contrast belongs to a neuropeptide family called neuroparsins, whose receptor is unknown. Here we demonstrate that a previously orphanized receptor tyrosine kinase (RTK) from A. aegypti encoded by the gene AAEL001915 is an OEH receptor. Phylogenetic studies indicated that the protein encoded by this gene, designated AAEL001915, belongs to a clade of RTKs related to the insulin receptor, which are distinguished by an extracellular Venus flytrap module. Knockdown of AAEL001915 by RNAi disabled OEH-mediated egg formation in A. aegypti. AAEL001915 was primarily detected in the mosquito ovary in association with follicular epithelial cells. Both monomeric and dimeric AAEL001915 were detected in mosquito ovaries and transfected Drosophila S2 cells. Functional assays further indicated that OEH bound to dimeric AAEL001915, which resulted in downstream phosphorylation of Ak strain transforming factor (Akt). We hypothesize that orthologs of AAEL001915 in other insects are neuroparsin receptors. PMID:25848040

  8. The human gonadotropin releasing hormone type I receptor is a functional intracellular GPCR expressed on the nuclear membrane.

    PubMed

    Re, Michelle; Pampillo, Macarena; Savard, Martin; Dubuc, Céléna; McArdle, Craig A; Millar, Robert P; Conn, P Michael; Gobeil, Fernand; Bhattacharya, Moshmi; Babwah, Andy V

    2010-07-08

    The mammalian type I gonadotropin releasing hormone receptor (GnRH-R) is a structurally unique G protein-coupled receptor (GPCR) that lacks cytoplasmic tail sequences and displays inefficient plasma membrane expression (PME). Compared to its murine counterparts, the primate type I receptor is inefficiently folded and retained in the endoplasmic reticulum (ER) leading to a further reduction in PME. The decrease in PME and concomitant increase in intracellular localization of the mammalian GnRH-RI led us to characterize the spatial distribution of the human and mouse GnRH receptors in two human cell lines, HEK 293 and HTR-8/SVneo. In both human cell lines we found the receptors were expressed in the cytoplasm and were associated with the ER and nuclear membrane. A molecular analysis of the receptor protein sequence led us to identify a putative monopartite nuclear localization sequence (NLS) in the first intracellular loop of GnRH-RI. Surprisingly, however, neither the deletion of the NLS nor the addition of the Xenopus GnRH-R cytoplasmic tail sequences to the human receptor altered its spatial distribution. Finally, we demonstrate that GnRH treatment of nuclei isolated from HEK 293 cells expressing exogenous GnRH-RI triggers a significant increase in the acetylation and phosphorylation of histone H3, thereby revealing that the nuclear-localized receptor is functional. Based on our findings, we conclude that the mammalian GnRH-RI is an intracellular GPCR that is expressed on the nuclear membrane. This major and novel discovery causes us to reassess the signaling potential of this physiologically and clinically important receptor.

  9. Age-Related Hearing Loss and Degeneration of Cochlear Hair Cells in Mice Lacking Thyroid Hormone Receptor β1.

    PubMed

    Ng, Lily; Cordas, Emily; Wu, Xuefeng; Vella, Kristen R; Hollenberg, Anthony N; Forrest, Douglas

    2015-10-01

    A key function of the thyroid hormone receptor β (Thrb) gene is in the development of auditory function. However, the roles of the 2 receptor isoforms, TRβ1 and TRβ2, expressed by the Thrb gene are unclear, and it is unknown whether these isoforms promote the maintenance as well as development of hearing. We investigated the function of TRβ1 in mice with a Thrb(b1) reporter allele that expresses β-galactosidase instead of TRβ1. In the immature cochlea, β-galactosidase was detected in the greater epithelial ridge, sensory hair cells, spiral ligament, and spiral ganglion and in adulthood, at low levels in the hair cells, support cells and root cells of the outer sulcus. Although deletion of all TRβ isoforms causes severe, early-onset deafness, deletion of TRβ1 or TRβ2 individually caused no obvious hearing loss in juvenile mice. However, over subsequent months, TRβ1 deficiency resulted in progressive loss of hearing and loss of hair cells. TRβ1-deficient mice had minimal changes in serum thyroid hormone and thyrotropin levels, indicating that hormonal imbalances were unlikely to cause hearing loss. The results suggest mutually shared roles for TRβ1 and TRβ2 in cochlear development and an unexpected requirement for TRβ1 in the maintenance of hearing in adulthood.

  10. Osteopontin deficiency enhances parathyroid hormone/ parathyroid hormone related peptide receptor (PPR) signaling-induced alteration in tooth formation and odontoblastic morphology.

    PubMed

    Morishita, Maki; Ono, Noriaki; Miyai, Kentano; Nakagawa, Tomomi; Hanyu, Ryo; Nagao, Masashi; Kamolratanakul, Paksinee; Notomi, Takuya; Rittling, Susan R; Denhardt, David T; Kronenberg, Henry M; Ezura, Yoichi; Hayata, Tadayoshi; Nakamoto, Tetsuya; Noda, Masaki

    2011-06-01

    Parathyroid hormone/parathyroid hormone-related protein receptor (PPR) signaling is known to be involved in tooth development. In bone, extracellular matrix protein osteopontin (OPN) is a negative regulator of PPR signaling in bone formation. However, the role of OPN in modulation of PPR action in tooth development is not understood. Therefore, we examined the tooth in double mutant mice. Constitutively active PPR was expressed specifically in the odontoblasts and osteoblasts (caPPR-tg) in the presence or absence of OPN. Radiographic analysis indicated that the length of the third molar (M3) and the incisor was decreased in the caPPR-tg mice compared to wild type, and such reduction in molar and incisor length was further enhanced in the absence of OPN (caPPR-tg OPN-KO). With respect to histology of incisors, caPPR-tg induced high cellularity and irregularity in odontoblastic shape and this was enhanced by the absence of OPN. These morphological observations suggest that OPN modulates PPR signaling that are involved in tooth formation.

  11. The association of chemotherapy versus hormonal therapy and health outcomes among patients with hormone receptor-positive, HER2-negative metastatic breast cancer: experience from the patient perspective.

    PubMed

    Gupta, Shaloo; Zhang, Jie; Jerusalem, Guy

    2014-12-01

    This study aimed to characterize the impact of metastatic breast cancer (MBC) and cancer treatments on health-related quality of life, treatment satisfaction, and daily productivity from the patient perspective. This was a cross-sectional survey of patients with MBC (USA, n = 200; EU, n = 160). Post-menopausal women aged ≥50 years with hormone receptor positive (HR+), HER2-negative (HER2-) MBC, currently using hormonal therapy (HT) or using chemotherapy (CT) for ≤1 year were recruited. Fifty three percent (n = 191) reported CT and 47% (n = 169) reported HT use. Adjusting for covariates, HT users reported greater health-related quality of life (p < 0.05), greater satisfaction with treatment and better feelings about side-effects (p < 0.001). HT users reported less bother with treatment side-effects (0-5 scale, p < 0.001) and less activity impairment than CT users (p < 0.001). HT was associated with better patient-reported outcomes than CT in first-line MBC management. These findings should be taken into consideration while making treatment decisions for HR+/HER2- MBC.

  12. Conserved Anti-Müllerian Hormone: Anti-Müllerian Hormone Type-2 Receptor Specific Interaction and Intracellular Signaling in Teleosts.

    PubMed

    Rocha, Ana; Zanuy, Silvia; Gómez, Ana

    2016-06-01

    In higher vertebrates, anti-Müllerian hormone (AMH) is required for Müllerian duct regression in fetal males. AMH is also produced during postnatal life in both sexes regulating steroidogenesis and early stages of folliculogenesis. Teleosts lack Müllerian ducts, but Amh has been identified in several species including European sea bass. However, information on Amh type-2 receptor (Amhr2), the specific receptor for Amh binding, is restricted to a couple of fish species. Here, we report on cloning sea bass amhr2, the production of a recombinant sea bass Amh, and the functional analysis of this ligand-receptor couple. Phylogenetic analysis revealed that sea bass amhr2 segregates with Amhr2 from other vertebrates. This piscine receptor is capable of activating Smad proteins. Antibodies raised against sea bass Amh were used to study native and recombinant Amh, revealing proteins in the range of 66-70 kDa corresponding to the full length Amh. Once proteolytically treated, recombinant sea bass Amh generates a 12 kDa C-terminal mature protein, suggesting that contrary to what has been described for other fish Amh proteins, this protein is processed in a similar way as mammalian AMH. The mature sea bass Amh is a biologically active protein able to bind sea bass Amhr2 and, surprisingly, also human AMHR2. In prepubertal sea bass testes, Amh was detected by immunohistochemistry mostly in Sertoli cells surrounding early germ-cell generations. During spermatogenesis, a weaker staining signal could be observed in Sertoli cells surrounding spermatocytes. PMID:27226310

  13. Atrazine inhibits pulsatile luteinizing hormone release without altering pituitary sensitivity to a gonadotropin-releasing hormone receptor agonist in female Wistar rats.

    PubMed

    Foradori, Chad D; Hinds, Laura R; Hanneman, William H; Legare, Marie E; Clay, Colin M; Handa, Robert J

    2009-07-01

    Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-tri-azine] is one of the most commonly used herbicides in the United States. Atrazine has been shown to suppress luteinizing hormone (LH) release and can lead to a prolongation of the estrous cycle in the rat. The objectives of this study were to examine the effects of atrazine on normal tonic release of LH and to elucidate the site of action of atrazine in the hypothalamic-pituitary-gonadal axis. Episodic release of gonadotropin-releasing hormone (GnRH) and the corresponding release of LH from the anterior pituitary gland are required for normal reproductive function. To determine if atrazine affects pulsatile LH release, ovariectomized adult female Wistar rats were administered atrazine (50, 100, or 200 mg/kg of body weight daily by gavage) or vehicle control for 4 days. On the final day of atrazine treatment, blood samples were obtained using an indwelling right atrial cannula. In the group receiving 200 mg/kg, there was a significant reduction in LH pulse frequency and a concomitant increase in pulse amplitude. To determine if the effects of atrazine on LH release were due to changes at the level of the pituitary, animals were passively immunized against endogenous GnRH, treated with atrazine, and challenged with a GnRH receptor agonist. Atrazine failed to alter pituitary sensitivity to the GnRH receptor agonist at any dose used. Taken together, these findings demonstrate that high doses of atrazine affect the GnRH pulse generator in the brain and not at the level of gonadotrophs in the pituitary.

  14. Thyroid Hormone Receptor α Plays an Essential Role in Male Skeletal Muscle Myoblast Proliferation, Differentiation, and Response to Injury.

    PubMed

    Milanesi, Anna; Lee, Jang-Won; Kim, Nam-Ho; Liu, Yan-Yun; Yang, An; Sedrakyan, Sargis; Kahng, Andrew; Cervantes, Vanessa; Tripuraneni, Nikita; Cheng, Sheue-yann; Perin, Laura; Brent, Gregory A

    2016-01-01

    Thyroid hormone plays an essential role in myogenesis, the process required for skeletal muscle development and repair, although the mechanisms have not been established. Skeletal muscle develops from the fusion of precursor myoblasts into myofibers. We have used the C2C12 skeletal muscle myoblast cell line, primary myoblasts, and mouse models of resistance to thyroid hormone (RTH) α and β, to determine the role of thyroid hormone in the regulation of myoblast differentiation. T3, which activates thyroid hormone receptor (TR) α and β, increased myoblast differentiation whereas GC1, a selective TRβ agonist, was minimally effective. Genetic approaches confirmed that TRα plays an important role in normal myoblast proliferation and differentiation and acts through the Wnt/β-catenin signaling pathway. Myoblasts with TRα knockdown, or derived from RTH-TRα PV (a frame-shift mutation) mice, displayed reduced proliferation and myogenic differentiation. Moreover, skeletal muscle from the TRα1PV mutant mouse had impaired in vivo regeneration after injury. RTH-TRβ PV mutant mouse model skeletal muscle and derived primary myoblasts did not have altered proliferation, myogenic differentiation, or response to injury when compared with control. In conclusion, TRα plays an essential role in myoblast homeostasis and provides a potential therapeutic target to enhance skeletal muscle regeneration.

  15. Crosstalk between Integrin αvβ3 and Estrogen Receptor-α Is Involved in Thyroid Hormone-Induced Proliferation in Human Lung Carcinoma Cells

    PubMed Central

    Meng, Ran; Tang, Heng-Yuan; Westfall, Jennifer; London, David; Cao, James H.; Mousa, Shaker A.; Luidens, Mary; Hercbergs, Aleck; Davis, Faith B.; Davis, Paul J.; Lin, Hung-Yun

    2011-01-01

    A cell surface receptor for thyroid hormone that activates extracellular regulated kinase (ERK) 1/2 has been identified on integrin αvβ3. We have examined the actions of thyroid hormone initiated at the integrin on human NCI-H522 non-small cell lung carcinoma and NCI-H510A small cell lung cancer cells. At a physiologic total hormone concentration (10−7 M), T4 significantly increased proliferating cell nuclear antigen (PCNA) abundance in these cell lines, as did 3, 5, 3′-triiodo-L-thyronine (T3) at a supraphysiologic concentration. Neutralizing antibody to integrin αvβ3 and an integrin-binding Arg-Gly-Asp (RGD) peptide blocked thyroid hormone-induced PCNA expression. Tetraiodothyroacetic acid (tetrac) lacks thyroid hormone function but inhibits binding of T4 and T3 to the integrin receptor; tetrac eliminated thyroid hormone-induced lung cancer cell proliferation and ERK1/2 activation. In these estrogen receptor-α (ERα)-positive lung cancer cells, thyroid hormone (T4>T3) caused phosphorylation of ERα; the specific ERα antagonist ICI 182,780 blocked T4-induced, but not T3-induced ERK1/2 activation, as well as ERα phosphorylation, proliferating-cell nuclear antigen (PCNA) expression and hormone-dependent thymidine uptake by tumor cells. Thus, in ERα-positive human lung cancer cells, the proliferative action of thyroid hormone initiated at the plasma membrane is at least in part mediated by ERα. In summary, thyroid hormone may be one of several endogenous factors capable of supporting proliferation of lung cancer cells. Activity as an inhibitor of lung cancer cell proliferation induced at the integrin receptor makes tetrac a novel anti-proliferative agent. PMID:22132110

  16. A NOVEL CELL LINE, MDA-KB2, THAT STABLY EXPRESSES AN ANDROGEN AND GLUCOCORTICOID RESPONSIVE REPORTER FOR THE DETECTION OF HORMONE RECEPTOR AGONISTS AND ANTAGONISTS

    EPA Science Inventory

    The U.S. Environmental Protection Agency has proposed that in vitro assays for estrogen receptor (ER) and androgen receptor (AR) mediated actions be included in a Tier I screening battery to detect hormonally active chemicals. Herein we describe the development of a novel stab...

  17. The PI3K/Akt and ERK pathways elevate thyroid hormone receptor β1 and TRH receptor to decrease thyroid hormones after exposure to PCB153 and p,p'-DDE.

    PubMed

    Liu, Changjiang; Li, Lianbing; Ha, Mei; Qi, Suqin; Duan, Peng; Yang, Kedi

    2015-01-01

    PCBs and DDT cause the disturbance of thyroid hormone (TH) homeostasis in humans and animals. To test the hypothesis that the PI3K/Akt and MAPK pathways would play significant roles in TH imbalance caused by PCBs and DDT, Sprague-Dawley rats were dosed with PCB153 and p,p'-DDE intraperitoneally for 5 consecutive days, and human thyroid follicular epithelial (Nthy-ori 3-1 cell line) were treated with PCB153 and p,p'-DDE for different time. Results showed that serum total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3) and thyroid stimulating hormone (TSH) were decreased, whereas serum free triiodothyronine (FT3) and thyrotropin releasing hormone (TRH) were not changed. The PI3K/Akt and ERK pathways were activated in vivo and in vitro after the treatment with PCB153 and p,p'-DDE. Moreover, TH receptor β1 (TRβ1) was elevated after the activation of the PI3K/Akt pathway and was depressed after the inhibition of the PI3K/Akt pathway; TRH receptor (TRHr) was increased after the activation of the ERK pathway and was decreased after the inhibition of the ERK pathway. Though TH receptor α1 (TRα1) level was increased in the hypothalamus, TRα1 and TSHr were not influenced by the status of signaling pathways in in vitro study. Taken together, after exposure to PCB153 and p,p'-DDE, activated PI3K/Akt and ERK pathways disrupt the hypothalamic-pituitary-thyroid (HPT) axis via TRβ1 and TRHr and then decrease TH levels, and that would be a potential mechanism by which PCBs and DDT disturb TH homeostasis.

  18. The atypical antipsychotic, olanzapine, potentiates ghrelin-induced receptor signaling: An in vitro study with cells expressing cloned human growth hormone secretagogue receptor.

    PubMed

    Tagami, Keita; Kashiwase, Yohei; Yokoyama, Akinobu; Nishimura, Hitomi; Miyano, Kanako; Suzuki, Masami; Shiraishi, Seiji; Matoba, Motohiro; Ohe, Yuichiro; Uezono, Yasuhito

    2016-08-01

    The growth hormone secretagogue receptor (GHS-R) belongs to Gαq-coupled G protein-coupled receptor (GPCR) that mediates growth hormone release, food intake, appetite, glucose metabolism and body composition. Ghrelin has been identified as an endogenous ligand for GHS-R, and it is the only orexigenic peptide found in the peripheral organs. Olanzapine, an atypical antipsychotic agent that binds to and inhibits the activation of GPCR for several neurotransmitters, has metabolic side effects such as excessive appetite and weight gain. Recently, studies have revealed that the orexigenic mechanism of olanzapine is mediated via GHS-R signaling, although the precise mechanisms have not been clarified. In this study, we investigated the effect of olanzapine on ghrelin-mediated GHS-R signaling by using an electrical impedance-based receptor biosensor assay system (CellKey™). Olanzapine at concentrations of 10(-7) and 10(-6)mol/L enhanced ghrelin-induced (10(-10)-10(-8)mol/L) GHS-R activation. A Ca(2+) imaging assay revealed that olanzapine (10(-7) and 10(-6)mol/L) enhanced ghrelin (10(-7) M)-induced GHS-R activity. In contrast, haloperidol (an antipsychotic agent) failed to enhance this ghrelin-mediated GHS-R activation, as demonstrated by both the CellKey™ and Ca(2+) imaging assays. Together, these results suggest that olanzapine, but not haloperidol, promotes appetite by enhancing ghrelin-mediated GHS-R signaling. PMID:26775231

  19. The emergence of the vasopressin and oxytocin hormone receptor gene family lineage: Clues from the characterization of vasotocin receptors in the sea lamprey (Petromyzon marinus).

    PubMed

    Mayasich, Sally A; Clarke, Benjamin L

    2016-01-15

    The sea lamprey (Petromyzon marinus) is a jawless vertebrate at an evolutionary nexus between invertebrates and jawed vertebrates. Lampreys are known to possess the arginine vasotocin (AVT) hormone utilized by all non-mammalian vertebrates. We postulated that the lamprey would possess AVT receptor orthologs of predecessors to the arginine vasopressin (AVP)/oxytocin (OXT) family of G protein-coupled receptors found in mammals, providing insights into the origins of the mammalian V1A, V1B, V2 and OXT receptors. Among the earliest animals to diverge from the vertebrate lineage in which these receptors are characterized is the jawed, cartilaginous elephant shark, which has genes orthologous to all four mammalian receptor types. Therefore, our work was aimed at helping resolve the critical gap concerning the outcomes of hypothesized large-scale (whole-genome) duplication events. We sequenced one partial and four full-length putative lamprey AVT receptor genes and determined their mRNA expression patterns in 15 distinct tissues. Phylogenetically, three of the full-coding genes possess structural characteristics of the V1 clade containing the V1A, V1B and OXT receptors. Another full-length coding gene and the partial sequence are part of the V2 clade and appear to be most closely related to the newly established V2B and V2C receptor subtypes. Our synteny analysis also utilizing the Japanese lamprey (Lethenteron japonicum) genome supports the recent proposal that jawless and jawed vertebrates shared one-round (1R) of WGD as the most likely scenario.

  20. Locust flight activity as a model for hormonal regulation of lipid mobilization and transport.

    PubMed

    Van der Horst, Dick J; Rodenburg, Kees W

    2010-08-01

    Flight activity of insects provides a fascinating yet relatively simple model system for studying the regulation of processes involved in energy metabolism. This is particularly highlighted during long-distance flight, for which the locust constitutes a long-standing favored model insect, which as one of the most infamous agricultural pests additionally has considerable economical importance. Remarkably many aspects and processes pivotal to our understanding of (neuro)hormonal regulation of lipid mobilization and transport during insect flight activity have been discovered in the locust; among which are the peptide adipokinetic hormones (AKHs), synthesized and stored by the neurosecretory cells of the corpus cardiacum, that regulate and integrate lipid (diacylglycerol) mobilization and transport, the functioning of the reversible conversions of lipoproteins (lipophorins) in the hemolymph during flight activity, revealing novel concepts for the transport of lipids in the circulatory system, and the structure and functioning of the exchangeable apolipopotein, apolipophorin III, which exhibits a dual capacity to exist in both lipid-bound and lipid-free states that is essential to these lipophorin conversions. Besides, the lipophorin receptor (LpR) was identified and characterized in the locust. In an integrative approach, this short review aims at highlighting the locust as an unrivalled model for studying (neuro)hormonal regulation of lipid mobilization and transport during insect flight activity, that additionally has offered a broad and profound research model for integrative physiology and biochemistry, and particularly focuses on recent developments in the concept of AKH-induced changes in the lipophorin system during locust flight, that deviates fundamentally from the lipoprotein-based transport of lipids in the circulation of mammals. Current studies in this field employing the locust as a model continue to attribute to its role as a favored model organism, but

  1. Structure of a Thyroid Hormone Receptor DNA-Binding Domain Homodimer Bound to an Inverted Palindrome DNA Response Element

    SciTech Connect

    Chen, Yi; Young, Matthew A.

    2010-10-22

    Thyroid hormone receptor (TR), as a member of the nuclear hormone receptor family, can recognize and bind different classes of DNA response element targets as either a monomer, a homooligomer, or a heterooligomer. We report here the first crystal structure of a homodimer TR DNA-binding domain (DBD) in complex with an inverted repeat class of thyroid response element (TRE). The structure shows a nearly symmetric structure of the TR DBD assembled on the F2 TRE where the base recognition contacts in the homodimer DNA complex are conserved relative to the previously published structure of a TR-9-cis-retinoic acid receptor heterodimer DNA complex. The new structure also reveals that the T-box region of the DBD can function as a structural hinge that enables a large degree of flexibility in the position of the C-terminal extension helix that connects the DBD to the ligand-binding domain. Although the isolated TR DBDs exist as monomers in solution, we have measured highly cooperative binding of the two TR DBD subunits onto the inverted repeat DNA sequence. This suggests that elements of the DBD can influence the specific TR oligomerization at target genes, and it is not just interactions between the ligand-binding domains that are responsible for TR oligomerization at target genes. Mutational analysis shows that intersubunit contacts at the DBD C terminus account for some, but not all, of the cooperative homodimer TR binding to the inverted repeat class TRE.

  2. Green fluorescent protein fused to peptide agonists of two dissimilar G protein-coupled receptors: novel ligands of the bradykinin B2 (rhodopsin family) receptor and parathyroid hormone PTH1 (secretin family) receptor.

    PubMed

    Charest-Morin, Xavier; Fortin, Jean-Philippe; Bawolak, Marie-Thérèse; Lodge, Robert; Marceau, François

    2013-10-01

    We hypothesized that peptide hormone sequences that stimulate and internalize G protein-coupled receptors (GPCRs) could be prolonged with a functional protein cargo. To verify this, we have selected two widely different pairs of peptide hormones and GPCRs that nevertheless share agonist-induced arrestin-mediated internalization. For the parathyroid hormone (PTH) PTH1 receptor (PTH1R) and the bradykinin (BK) B2 receptor (B2R), we have designed fusion proteins of the agonists PTH1-34 and maximakinin (MK, a BK homologue) with the enhanced green fluorescent protein (EGFP), thus producing candidate high molecular weight ligands. According to docking models of each hormone to its receptor, EGFP was fused either at the N-terminus (MK) or C-terminus (PTH1-34) of the ligand; the last construction is also secretable due to inclusion of the preproinsulin signal peptide and has been produced as a conditioned medium. EGFP-MK has been produced as a lysate of transfected cells. Using an enzyme-linked immunosorbent assay (ELISA) for GFP, average concentrations of 1.5 and 1670 nmol/L, respectively, of ligand were found in these preparations. The functional properties and potential of these analogs for imaging receptor-expressing cells were examined. Microscopic and cytofluorometric evidence of specific binding and internalization of both fusion proteins was obtained using recipient HEK 293a cells that expressed the cognate recombinant receptor. Endosomal colocalization studies were conducted (Rab5, Rab7, β-arrestin1). Evidence of agonist signaling was obtained (expression of c-Fos, cyclic AMP responsive element (CRE) reporter gene for PTH1-34-EGFP). The constructs PTH1-34-EGFP and EGFP-MK represent bona fide agonists that support the feasibility of transporting protein cargoes inside cells using GPCRs.

  3. Water scorpions (Heteroptera, Nepidae) and giant water bugs (Heteroptera, Belostomatidae): sources of new members of the adipokinetic hormone/red pigment-concentrating hormone family.

    PubMed

    Gäde, Gerd; Simek, Petr; Marco, Heather G

    2007-07-01

    Two novel octapeptide members of the AKH/RPCH family have been identified from the corpora cardiaca (CC) of two species of water bugs. The giant water bug Lethocerus indicus (family: Belostomatidae) contains a peptide code-named Letin-AKH with the sequence pGlu-Val-Asn-Phe-Ser-Pro-Tyr-Trp amide, and the water scorpion Nepa cinerea (family: Nepidae) has the peptide code-named Nepci-AKH with the sequence pGlu-Leu/Ile-Asn-Phe-Ser-Ser-Gly-Trp amide. The sequences were deduced from the multiple MS(N) electrospray mass data from crude CC extracts. Synthetic peptides were made and co-elution on reversed-phase high performance liquid chromatography (RP-HPLC) with the natural peptide from crude gland extract confirmed the accuracy of the deduced sequence for Letin-AKH and demonstrated that Nepci-AKH contains a Leu residue at position 2 and not an Ile residue. A previously characterized member of the AKH/RPCH family was identified in the stick water scorpion Ranatra linearis by mass spectrometry: Grybi-AKH (pGlu-Val-Asn-Phe-Ser-Thr-Gly-Trp amide) has the same mass (919 Da) as Nepci-AKH and differs in two positions from Nepci-AKH (residues 2 and 6). The apparent function of the peptides is to achieve lipid mobilization in the species under investigation; indications for this came from conspecific bioassays using the appropriate synthetic peptides for injecting into the insects. This function is very likely linked to dispersal flight metabolism of water bugs. Swimming activity in N. cinerea also results in an increase in lipid concentration in the hemolymph.

  4. Comparative peptidomics of four related hemipteran species: Pyrokinins, myosuppressin, corazonin, adipokinetic hormone, sNPF, and periviscerokinins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We performed the first comprehensive peptidomic analysis of neurohormones from hemipteran insects by analyzing the neuropeptides of two major neurohemal organs, namely the corpora cardiaca and abdominal perisympathetic organs. For the experiments we selected four related species of polyphagous stin...

  5. Luteal versus follicular phase surgical oophorectomy plus tamoxifen in premenopausal women with metastatic hormone receptor positive breast cancer

    PubMed Central

    Love, Richard R.; Hossain, Syed Mozammel; Hussain, Md. Margub; Mostafa, Mohammad Golam; Laudico, Adriano V.; Siguan, Stephen Sixto S.; Adebamowo, Clement; Sun, Jing-zhong; Fei, Fei; Shao, Zhi-Ming; Yunjiang, Liu; Akram Hussain, Syed Md.; Zhang, Baoning; Lin, Cheng; Panigaro, Sonar; Walta, Fardiana; Chuan, Jiang Hong; Mirasol-Lumague, Maria Rica; Yip, Cheng-Har; Navarro, Narciso S.; Huang, Chiun-sheng; Lu, Yen-shen; Ferdousy, Tahmina; Salim, Reza; Akhter, Chameli; Nahar, Shamsun; Uy, Gemma; Young, Gregory S.; Hade, Erinn M.; Jarjoura, David

    2016-01-01

    Purpose In premenopausal women with metastatic hormone receptor positive breast cancer, hormonal therapy is the first line therapy. GnRH + tamoxifen therapies have been found to be more effective. The pattern of recurrence risk over time after primary surgery suggests that peri-operative factors impact recurrence. Secondary analyses of an adjuvant trial suggested that the luteal phase timing of surgical oophorectomy in the menstrual cycle simultaneous with primary breast surgery favorably influenced long-term outcomes. Methods 249 premenopausal women with incurable or metastatic hormone receptor positive breast cancer entered a trial in which they were randomized to historical mid-luteal or mid-follicular phase surgical oophorectomy followed by oral tamoxifen treatment. Kaplan-Meier methods, the log-rank test, and multivariable Cox regression models were used to assess overall and progression free survival in the two randomized groups and by hormone confirmed menstrual cycle phase. Results Overall survival (OS) and progression-free survival were not demonstrated to be different in the two randomized groups. In a secondary analysis, OS appeared worse in luteal phase surgery patients with progesterone levels of <2ng/ml (anovulatory patients) (adjusted hazard ratio 1.46, 95% CI: 0.89–2.41, p=0.14) compared to patients in luteal phase with progesterone 2ng/ml or higher. Median overall survival was 2.0 years (95% CI: 1.7 – 2.3) and OS at 4 years was 26%. Conclusions The history-based timing of surgical oophorectomy in the menstrual cycle did not influence outcomes in this trial of metastatic patients. ClinicalTrials.gov number NCT 00293540 PMID:27107325

  6. MRI Kinetics With Volumetric Analysis in Correlation With Hormonal Receptor Subtypes and Histologic Grade of Invasive Breast Cancers

    PubMed Central

    Leong, Lester Chee Hao; Gombos, Eva C.; Jagadeesan, Jayender; Fook-Chong, Stephanie Man Chung

    2016-01-01

    OBJECTIVE The aim of this study was to assess whether computer-assisted detection–processed MRI kinetics data can provide further information on the biologic aggressiveness of breast tumors. MATERIALS AND METHODS We identified 194 newly diagnosed invasive breast cancers presenting as masses on contrast-enhanced MRI by a HIPAA-compliant pathology database search. Computer-assisted detection–derived data for the mean and median peak signal intensity percentage increase, most suspicious kinetic curve patterns, and volumetric analysis of the different kinetic patterns by mean percentage tumor volume were compared against the different hormonal receptor (estrogen-receptor [ER], progesterone-receptor [PR], ERRB2 (HER2/neu), and triple-receptor expressivity) and histologic grade subgroups, which were used as indicators of tumor aggressiveness. RESULTS The means and medians of the peak signal intensity percentage increase were higher in ER-negative, PR-negative, and triple-negative (all p ≤ 0.001), and grade 3 tumors (p = 0.011). Volumetric analysis showed higher mean percentage volume of rapid initial enhancement in biologically more aggressive ER-negative, PR-negative, and triple-negative tumors compared with ER-positive (64% vs 53.6%, p = 0.013), PR-positive (65.4% vs 52.5%, p = 0.001), and nontriple-negative tumors (65.3% vs 54.6%, p = 0.028), respectively. A higher mean percentage volume of rapid washout component was seen in ERRB2-positive tumors compared with ERRB2-negative tumors (27.5% vs 17.9%, p = 0.020). CONCLUSION Peak signal intensity percentage increase and volume analysis of the different kinetic patterns of breast tumors showed correlation with hormonal receptor and histologic grade indicators of cancer aggressiveness. Computer-assisted detection–derived MRI kinetics data have the potential to further characterize the aggressiveness of an invasive cancer. PMID:25714321

  7. Structure of the human luteinizing hormone-choriogonadotropin receptor gene: unusual promoter and 5' non-coding regions.

    PubMed

    Atger, M; Misrahi, M; Sar, S; Le Flem, L; Dessen, P; Milgrom, E

    1995-06-01

    The complete organization of the human luteinizing hormone-choriogonadotropin (LH/CG) receptor (LH/CGR) gene and the structure of 1591 bp of its 5' flanking region have been determined. This gene spans over 70 kbp and contains 11 exons. The first ten exons and part of the last exon encode the extracellular domain of the receptor while the transmembrane and intracellular domains are encoded by the remaining part of the last exon. The gene encodes a 701 amino acids long preprotein, contrary to a previous report of 699 amino acids. Primer extension experiments and polymerase chain reaction (PCR) mapping allowed definition of the transcription initiation site, which is located 1085 bp upstream from the initiation codon. The 5' non-coding region is thus unusually long. The promoter region which is different from the murine LH/CG receptor promoter, contains two putative TATA boxes at positions -34 and -47 and a CAAT box consensus sequence at position -89. A consensus sequence corresponding to a cAMP responsive element is found at position -697. Seven API consensus sequences are also found in the 5' flanking region of the gene. Southern blot experiments demonstrated an informative biallelic polymorphism within the human LH/CG receptor gene locus using BglI