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Sample records for receptors regulate steroid

  1. Mitochondrial benzodiazepine receptors regulate steroid biosynthesis

    International Nuclear Information System (INIS)

    Mukhin, A.G.; Papadopoulos, V.; Costa, E.; Krueger, K.E.

    1989-01-01

    Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine binding sites were tested for their effects on a well-established steroidogenic model system, the Y-1 mouse adrenal tumor cell line. 4'-Chlorodiazepam, PK 11195, and PK 14067 stimulated steroid production by 2-fold in Y-1 cells, whereas diazepam, flunitrazepam, zolpidem, and PK 14068 displayed a lower (1.2- to 1.5-fold) maximal stimulation. In contrast, clonazepam and flumazenil did not stimulate steroid synthesis. The potencies of these compounds to inhibit 3 H-labeled PK 11195 binding to peripheral-type benzodiazepine recognition sites correlated with their potencies to stimulate steroid production. Similar findings were observed in bovine and rat adrenocortical cell preparations. These results suggest that ligands of the peripheral-type benzodiazepine recognition site acting on this mitochondrial receptor can enhance steroid production. This action may contribute specificity to the pharmacological profile of drugs preferentially acting on the benzodiazepine recognition site associated with the outer membrane of certain mitochondrial populations

  2. Mitochondrial benzodiazepine receptors regulate steroid biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Mukhin, A.G.; Papadopoulos, V.; Costa, E.; Krueger, K.E. (Georgetown Univ. School of Medicine, Washington, DC (USA))

    1989-12-01

    Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine binding sites were tested for their effects on a well-established steroidogenic model system, the Y-1 mouse adrenal tumor cell line. 4{prime}-Chlorodiazepam, PK 11195, and PK 14067 stimulated steroid production by 2-fold in Y-1 cells, whereas diazepam, flunitrazepam, zolpidem, and PK 14068 displayed a lower (1.2- to 1.5-fold) maximal stimulation. In contrast, clonazepam and flumazenil did not stimulate steroid synthesis. The potencies of these compounds to inhibit {sup 3}H-labeled PK 11195 binding to peripheral-type benzodiazepine recognition sites correlated with their potencies to stimulate steroid production. Similar findings were observed in bovine and rat adrenocortical cell preparations. These results suggest that ligands of the peripheral-type benzodiazepine recognition site acting on this mitochondrial receptor can enhance steroid production. This action may contribute specificity to the pharmacological profile of drugs preferentially acting on the benzodiazepine recognition site associated with the outer membrane of certain mitochondrial populations.

  3. Mitochondrial benzodiazepine receptors regulate steroid biosynthesis.

    OpenAIRE

    Mukhin, A G; Papadopoulos, V; Costa, E; Krueger, K E

    1989-01-01

    Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine bin...

  4. Ovarian steroids regulate tachykinin and tachykinin receptor gene expression in the mouse uterus

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    Patak Eva

    2009-07-01

    Full Text Available Abstract Background In the mouse uterus, pregnancy is accompanied by changes in tachykinin and tachykinin receptor gene expression and in the uterotonic effects of endogenous tachykinins. In this study we have investigated whether changes in tachykinin expression and responses are a result of changes in ovarian steroid levels. Methods We quantified the mRNAs of tachykinins and tachykinin receptors in uteri from ovariectomized mice and studied their regulation in response to estrogen and progesterone using real-time quantitative RT-PCR. Early (3 h and late (24 h responses to estrogen were evaluated and the participation of the estrogen receptors (ER, ERalpha and ERbeta, was analyzed by treating mice with propylpyrazole triol, a selective ERalpha agonist, or diarylpropionitrile, a selective agonist of ERbeta. Results All genes encoding tachykinins (Tac1, Tac2 and Tac4 and tachykinin receptors (Tacr1, Tacr2 and Tacr3 were expressed in uteri from ovariectomized mice. Estrogen increased Tac1 and Tacr1 mRNA after 3 h and decreased Tac1 and Tac4 expression after 24 h. Tac2 and Tacr3 mRNA levels were decreased by estrogen at both 3 and 24 h. Most effects of estrogen were also observed in animals treated with propylpyrazole triol. Progesterone treatment increased the levels of Tac2. Conclusion These results show that the expression of tachykinins and their receptors in the mouse uterus is tightly and differentially regulated by ovarian steroids. Estrogen effects are mainly mediated by ERalpha supporting an essential role for this estrogen receptor in the regulation of the tachykinergic system in the mouse uterus.

  5. Steroid receptor coactivator-3 regulates glucose metabolism in bladder cancer cells through coactivation of hypoxia inducible factor 1α.

    Science.gov (United States)

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-04-18

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as "Warburg effect," to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy.

  6. Hormonal regulation of steroid receptor coactivator-1 mRNA in the male and female green anole brain.

    Science.gov (United States)

    Kerver, H N; Wade, J

    2015-03-01

    Green anole lizards are seasonal breeders, with male sexual behaviour primarily regulated by an annual increase in testosterone. Morphological, biochemical and behavioural changes associated with reproduction are activated by testosterone, generally with a greater effect in the breeding season (BS) than in the nonbreeding season (NBS). The present study investigates the possibility that differences in a steroid receptor coactivator may regulate this seasonal difference in responsiveness to testosterone. In situ hybridisation was used to examine the expression of steroid receptor coactivator-1 (SRC-1) in the brains of gonadally intact male and female green anoles across breeding states. A second experiment examined gonadectomised animals with and without testosterone treatment. Gonadally intact males had more SRC-1 expressing cells in the preoptic area and larger volumes of this region as defined by these cells than females. Main effects of both sex and season (males > females and BS > NBS) were present in cell number and volume of the ventromedial hypothalamus. An interaction between sex and season suggested that high expression in BS males was driving these effects. In hormone-manipulated animals, testosterone treatment increased both the number of SRC-1 expressing cells in and volumes of the preoptic area and amygdala. These results suggest that testosterone selectively regulates SRC-1, and that this coactivator may play a role in facilitating reproductive behaviours across both sexes. However, changes in SRC-1 expression are not likely responsible for the seasonal change in responsiveness to testosterone. © 2014 British Society for Neuroendocrinology.

  7. The regulation of steroid receptors by epigallocatechin-3-gallate in breast cancer cells

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    Hallman K

    2017-05-01

    Full Text Available Kelly Hallman,* Katie Aleck,* Meghan Quigley, Brigitte Dwyer, Victoria Lloyd, Monica Szmyd, Sumi Dinda Biomedical Diagnostic and Therapeutic Sciences, School of Health Sciences, Center for Biomedical Research, Oakland University, Rochester, MI, USA *These authors contributed equally to this work Abstract: It has been reported that phytoestrogen epigallocatechin gallate (EGCG suppresses cancer cell proliferation and may have antitumor properties. In this study, we analyzed the effects of EGCG on estrogen receptor α (ERα and progesterone receptor in hormone-dependent T-47D breast cancer cells. Western blot analysis revealed EGCG induced a concentration-dependent decrease in ERα protein levels, with a 56% reduction occurring with 60 µM EGCG when compared to controls. Downregulation of ERα protein levels was observed after 24-hour co-treatment of T-47D cells with 60 µM EGCG and 10 nM 17β-estradiol (E2. The proliferative effect of E2 on cell viability was reversed when treated in combination with EGCG. In contrast, the combination of EGCG with the pure ER antagonist, ICI 182, 780, showed no further reduction in cell number as only 5% of the cells were viable after 6 days of treatment. These studies may provide further understanding of the interactions among flavonoids and steroid receptors in breast cancer cells. Keywords: phytoestrogen, ER, PR, T-47D, antiestrogens

  8. Hsp70 cochaperones HspBP1 and BAG-1M differentially regulate steroid hormone receptor function.

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    Regina T Knapp

    Full Text Available Hsp70 binding protein 1 (HspBP1 and Bcl2-associated athanogene 1 (BAG-1, the functional orthologous nucleotide exchange factors of the heat shock protein 70 kilodalton (Hsc70/Hsp70 chaperones, catalyze the release of ADP from Hsp70 while inducing different conformational changes of the ATPase domain of Hsp70. An appropriate exchange rate of ADP/ATP is crucial for chaperone-dependent protein folding processes. Among Hsp70 client proteins are steroid receptors such as the glucocorticoid receptor (GR, the mineralocorticoid receptor (MR, and the androgen receptor (AR. BAG-1 diversely affects steroid receptor activity, while to date the influence of HspBP1 on steroid receptor function is mostly unknown. Here, we compared the influence of HspBP1 and BAG-1M on Hsp70-mediated steroid receptor folding complexes and steroid receptor activity. Coimmunoprecipitation studies indicated preferential binding of Hsp40 and the steroid receptors to BAG-1M as compared to HspBP1. Furthermore, Hsp70 binding to the ligand-binding domain of GR was reduced in the presence of HspBP1 but not in the presence of BAG-1M as shown by pull-down assays. Reporter gene experiments revealed an inhibitory effect on GR, MR, and AR at a wide range of HspBP1 protein levels and at hormone concentrations at or approaching saturation. BAG-1M exhibited a transition from stimulatory effects at low BAG-1M levels to inhibitory effects at higher BAG-1M levels. Overall, BAG-1M and HspBP1 had differential impacts on the dynamic composition of steroid receptor folding complexes and on receptor function with important implications for steroid receptor physiology.

  9. Dynamic Regulation of FoxA1 by Steroid Receptors | Center for Cancer Research

    Science.gov (United States)

    The estrogen receptor (ER) is a key regulator in breast cancer initiation and progression. A widely discussed model proposes that forkhead box protein A1 (FoxA1) acts as a pioneer factor in cancer by binding and penetrating closed chromatin to allow access by transcription factors (TFs), including ER.

  10. 3D model of amphioxus steroid receptor complexed with estradiol

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Michael E., E-mail: mbaker@ucsd.edu [Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0693 (United States); Chang, David J. [Department of Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0693 (United States)

    2009-08-28

    The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.

  11. Effects of estradiol and progestogens on human breast cells: Regulation of sex steroid receptors

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    Fang-Ping Chen

    2013-09-01

    Conclusions: The combination of E2 and various progestogens resulted in diverging effects on ERs and PRs expressions, which induced different effects on MCF-7 cell growth. Compared with P4, aberrant hormone and biological activity of synthetic progestin, by way of altered receptor expression, may be an important factor in affecting breast cell growth.

  12. Neuroactive Steroids: Receptor Interactions and Responses

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    Kald Beshir Tuem

    2017-08-01

    Full Text Available Neuroactive steroids (NASs are naturally occurring steroids, which are synthesized centrally as de novo from cholesterol and are classified as pregnane, androstane, and sulfated neurosteroids (NSs. NASs modulate many processes via interacting with gamma-aminobutyric acid (GABA, N-methyl-d-aspartate, serotonin, voltage-gated calcium channels, voltage-dependent anion channels, α-adrenoreceptors, X-receptors of the liver, transient receptor potential channels, microtubule-associated protein 2, neurotrophin nerve growth factor, and σ1 receptors. Among these, NSs (especially allopregnanolone have high potency and extensive GABA-A receptors and hence demonstrate anticonvulsant, anesthetic, central cytoprotectant, and baroreflex inhibitory effects. NSs are also involved in mood and learning via serotonin and anti-nociceptive activity via T-type voltage-gated Ca2+ channels. Moreover, they are modulators of mitochondrial function, synaptic plasticity, or regulators of apoptosis, which have a role in neuroprotective via voltage-dependent anion channels receptors. For proper functioning, NASs need to be in their normal level, whereas excess and deficiency may lead to abnormalities. When they are below the normal, NSs could have a part in development of depression, neuro-inflammation, multiple sclerosis, experimental autoimmune encephalitis, epilepsy, and schizophrenia. On the other hand, stress and attention deficit disorder could occur during excessive level. Overall, NASs are very important molecules with major neuropsychiatric activity.

  13. Steroid receptors and their ligands: Effects on male gamete functions

    International Nuclear Information System (INIS)

    Aquila, Saveria; De Amicis, Francesca

    2014-01-01

    In recent years a new picture of human sperm biology is emerging. It is now widely recognized that sperm contain nuclear encoded mRNA, mitochondrial encoded RNA and different transcription factors including steroid receptors, while in the past sperm were considered incapable of transcription and translation. One of the main targets of steroid hormones and their receptors is reproductive function. Expression studies on Progesterone Receptor, estrogen receptor, androgen receptor and their specific ligands, demonstrate the presence of these systems in mature spermatozoa as surface but also as nuclear conventional receptors, suggesting that both systemic and local steroid hormones, through sperm receptors, may influence male reproduction. However, the relationship between the signaling events modulated by steroid hormones and sperm fertilization potential as well as the possible involvement of the specific receptors are still controversial issues. The main line of this review highlights the current research in human sperm biology examining new molecular systems of response to the hormones as well as specific regulatory pathways controlling sperm cell fate and biological functions. Most significant studies regarding the identification of steroid receptors are reported and the mechanistic insights relative to signaling pathways, together with the change in sperm metabolism energy influenced by steroid hormones are discussed.The reviewed evidences suggest important effects of Progesterone, Estrogen and Testosterone and their receptors on spermatozoa and implicate the involvement of both systemic and local steroid action in the regulation of male fertility potential. - Highlights: • One of the main targets of steroid hormones and their receptors is reproductive function. • Pg/PR co-work to stimulate enzymatic activities to sustain a capacitation process. • E2/ERs regulate sperm motility, capacitation and acrosome reaction and act as survival factors. • Androgens

  14. Steroid receptors and their ligands: Effects on male gamete functions

    Energy Technology Data Exchange (ETDEWEB)

    Aquila, Saveria; De Amicis, Francesca, E-mail: francesca.deamicis@unical.it

    2014-11-01

    In recent years a new picture of human sperm biology is emerging. It is now widely recognized that sperm contain nuclear encoded mRNA, mitochondrial encoded RNA and different transcription factors including steroid receptors, while in the past sperm were considered incapable of transcription and translation. One of the main targets of steroid hormones and their receptors is reproductive function. Expression studies on Progesterone Receptor, estrogen receptor, androgen receptor and their specific ligands, demonstrate the presence of these systems in mature spermatozoa as surface but also as nuclear conventional receptors, suggesting that both systemic and local steroid hormones, through sperm receptors, may influence male reproduction. However, the relationship between the signaling events modulated by steroid hormones and sperm fertilization potential as well as the possible involvement of the specific receptors are still controversial issues. The main line of this review highlights the current research in human sperm biology examining new molecular systems of response to the hormones as well as specific regulatory pathways controlling sperm cell fate and biological functions. Most significant studies regarding the identification of steroid receptors are reported and the mechanistic insights relative to signaling pathways, together with the change in sperm metabolism energy influenced by steroid hormones are discussed.The reviewed evidences suggest important effects of Progesterone, Estrogen and Testosterone and their receptors on spermatozoa and implicate the involvement of both systemic and local steroid action in the regulation of male fertility potential. - Highlights: • One of the main targets of steroid hormones and their receptors is reproductive function. • Pg/PR co-work to stimulate enzymatic activities to sustain a capacitation process. • E2/ERs regulate sperm motility, capacitation and acrosome reaction and act as survival factors. • Androgens

  15. A novel ecdysone receptor mediates steroid-regulated developmental events during the mid-third instar of Drosophila.

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    Benjamin F B Costantino

    2008-06-01

    Full Text Available The larval salivary gland of Drosophila melanogaster synthesizes and secretes glue glycoproteins that cement developing animals to a solid surface during metamorphosis. The steroid hormone 20-hydroxyecdysone (20E is an essential signaling molecule that modulates most of the physiological functions of the larval gland. At the end of larval development, it is known that 20E--signaling through a nuclear receptor heterodimer consisting of EcR and USP--induces the early and late puffing cascade of the polytene chromosomes and causes the exocytosis of stored glue granules into the lumen of the gland. It has also been reported that an earlier pulse of hormone induces the temporally and spatially specific transcriptional activation of the glue genes; however, the receptor responsible for triggering this response has not been characterized. Here we show that the coordinated expression of the glue genes midway through the third instar is mediated by 20E acting to induce genes of the Broad Complex (BRC through a receptor that is not an EcR/USP heterodimer. This result is novel because it demonstrates for the first time that at least some 20E-mediated, mid-larval, developmental responses are controlled by an uncharacterized receptor that does not contain an RXR-like component.

  16. Ligand-independent recruitment of steroid receptor coactivators to estrogen receptor by cyclin D1

    NARCIS (Netherlands)

    Zwijsen, R.M.L.; Buckle, R.S.; Hijmans, E.M.; Loomans, C.J.M.; Bernards, R.A.

    1998-01-01

    The estrogen receptor (ER) is an important regulator of growth and differentiation of breast epithelium. Transactivation by ER depends on a leucine-rich motif, which constitutes a ligand-regulated binding site for steroid receptor coactivators (SRCs). Cyclin D1 is frequently amplified in breast

  17. The First Fifteen Years of Steroid Receptor Research in Zebrafish; Characterization and Functional Analysis of the Receptors

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    Marcel J. M. Schaaf

    2017-07-01

    Full Text Available Steroid hormones regulate a wide range of processes in our body, and their effects are mediated by steroid receptors. In addition to their physiological role, these receptors mediate the effects of endocrine disrupting chemicals (EDCs and are widely used targets for dugs involved in the treatment of numerous diseases, ranging from cancer to inflammatory disorders. Over the last fifteen years, the zebrafish has increasingly been used as an animal model in steroid receptor research. Orthologues of all human steroid receptor genes appear to be present in zebrafish. All zebrafish steroid receptors have been characterized in detail, and their expression patterns have been analyzed. Functional studies have been performed using morpholino knockdown of receptor expression and zebrafish lines carrying mutations in one of their steroid receptor genes. To investigate the activity of the receptors in vivo, specific zebrafish reporter lines have been developed, and transcriptomic studies have been carried out to identify biomarkers for steroid receptor action. In this review, an overview of research on steroid receptors in zebrafish is presented, and it is concluded that further exploitation of the possibilities of the zebrafish model system will contribute significantly to the advancement of steroid receptor research in the next decade.

  18. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways.

    Science.gov (United States)

    Narayanan, Ramesh; Coss, Christopher C; Yepuru, Muralimohan; Kearbey, Jeffrey D; Miller, Duane D; Dalton, James T

    2008-11-01

    Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.

  19. Specific DNA-binding proteins and DNA sequences involved in steroid hormone regulation of gene expression

    International Nuclear Information System (INIS)

    Spelsberg, T.; Hora, J.; Horton, M.; Goldberger, A.; Littlefield, B.; Seelke, R.; Toyoda, H.

    1987-01-01

    Steroid hormones circulate in the blood and are taken by target cells via complexes with intracellular binding proteins termed receptors, that are hormone and tissue specific. Each receptor binds it specific steroid with very high affinity, having an equilibrium dissociation constant (K/sub d/) in the range of 10 -9 to 10 -10 M. Once bound by their specific steroid hormones, the steroid receptors undergo a conformational change which allows them to bind with high affinity to sites on chromatin, termed nuclear acceptor sites. There are estimated 5,000 to 10,000 of these sites expressed with an equal number not expressed (''masked'') in intact chromatin. The result of the binding to nuclear acceptor sites is an alteration of gene transcription or, in some cases, gene expression as measured by the changing levels of specific RNAs and proteins in that target tissue. Each steroid regulates specific effects on the RNA and protein profiles. The chronology of the above mechanism of action after injection of radiolabelled steroid as is follows: Steroid-receptor complex formation (1 minute), nuclear acceptor sites (2 minutes), effects on RNA synthesis (10 to 30 minutes), and finally the changing protein profiles via changes in protein synthesis and protein turnover (1 to 6 hours). Thus steroid receptors represent one of the first identified intracellular gene regulation proteins. The receptor molecules themselves are regulated by the presence or absence of the steroid molecule

  20. Steroid receptor expression in the fish inner earvaries with sex, social status, and reproductive state

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    Fernald Russell D

    2010-04-01

    Full Text Available Abstract Background Gonadal and stress-related steroid hormones are known to influence auditory function across vertebrates but the cellular and molecular mechanisms responsible for steroid-mediated auditory plasticity at the level of the inner ear remain unknown. The presence of steroid receptors in the ear suggests a direct pathway for hormones to act on the peripheral auditory system, but little is known about which receptors are expressed in the ear or whether their expression levels change with internal physiological state or external social cues. We used qRT-PCR to measure mRNA expression levels of multiple steroid receptor subtypes (estrogen receptors: ERα, ERβa, ERβb; androgen receptors: ARα, ARβ; corticosteroid receptors: GR2, GR1a/b, MR and aromatase in the main hearing organ of the inner ear (saccule in the highly social African cichlid fish Astatotilapia burtoni, and tested whether these receptor levels were correlated with circulating steroid concentrations. Results We show that multiple steroid receptor subtypes are expressed within the main hearing organ of a single vertebrate species, and that expression levels differ between the sexes. We also show that steroid receptor subtype-specific changes in mRNA expression are associated with reproductive phase in females and social status in males. Sex-steroid receptor mRNA levels were negatively correlated with circulating estradiol and androgens in both males and females, suggesting possible ligand down-regulation of receptors in the inner ear. In contrast, saccular changes in corticosteroid receptor mRNA levels were not related to serum cortisol levels. Circulating steroid levels and receptor subtype mRNA levels were not as tightly correlated in males as compared to females, suggesting different regulatory mechanisms between sexes. Conclusions This is the most comprehensive study of sex-, social-, and reproductive-related steroid receptor mRNA expression in the peripheral

  1. Steroid Hormone Receptor Signals as Prognosticators for Urothelial Tumor

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    Hiroki Ide

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    1988-01-01

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

  4. Unraveling the mechanisms underlying the rapid vascular effects of steroids: sorting out the receptors and the pathways.

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    Feldman, Ross D; Gros, Robert

    2011-07-01

    Aldosterone, oestrogens and other vasoactive steroids are important physiological and pathophysiological regulators of cardiovascular and metabolic function. The traditional view of the cardiovascular actions of these vasoactive steroids has focused on their roles as regulators of transcription via activation of their 'classical' receptors [mineralocorticoid receptors (MR) and oestrogen receptors (ER)]. However, based on a series of observations going back more than half a century, scientists have speculated that a range of steroids, including oestrogen and aldosterone, might have effects on regulation of smooth muscle contractility, cell growth and differentiation that are too rapid to be accounted for by transcriptional regulation. Recent studies performed in our laboratories (and those of others) have begun to elucidate the mechanism of rapid steroid-mediated cardiometabolic regulation. GPR30, now designated as GPER-1 (http://www.iuphar-db.org/DATABASE/FamilyIntroductionForward?familyId=22), a newly characterized 'orphan receptor', has been implicated in mediating the rapid effects of estradiol and most recently those of aldosterone. Studies to date have taught us that to understand the rapid vascular mechanisms of steroids, one must (i) know which vascular 'compartment' the steroid is acting; (ii) know which receptor the steroid hormone is activating; and (iii) not assume the receptor specificity of a steroid receptor ligand based solely on its selectivity for its traditional 'transcriptional' steroid receptor. Our newfound appreciation of the rapid effects of steroids such as aldosterone and oestrogens opens up a new vista for advancing our understanding of the biology and pathobiology of vascular regulation. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  5. Steroids as central regulators of organismal development and lifespan.

    Directory of Open Access Journals (Sweden)

    Siu Sylvia Lee

    Full Text Available Larvae of the nematode Caenorhabditis elegans must choose between reproductive development and dauer diapause. This decision is based on sensing of environmental inputs and dauer pheromone, a small molecule signal that serves to monitor population density. These signals are integrated via conserved neuroendocrine pathways that converge on steroidal ligands of the nuclear receptor DAF-12, a homolog of the mammalian vitamin D receptor and liver X receptor. DAF-12 acts as the main switch between gene expression programs that drive either reproductive development or dauer entry. Extensive studies in the past two decades demonstrated that biosynthesis of two bile acid-like DAF-12 ligands, named dafachronic acids (DA, controls developmental fate. In this issue of PLoS Biology, Wollam et al. showed that a conserved steroid-modifying enzyme, DHS-16, introduces a key feature in the structures of the DAF-12 ligands, closing a major gap in the DA biosynthesis pathway. The emerging picture of DA biosynthesis in C. elegans enables us to address a key question in the field: how are complex environmental signals integrated to enforce binary, organism-wide decisions on developmental fate? Schaedel et al. demonstrated that pheromone and DA serve as competing signals, and that a positive feedback loop based on regulation of DA biosynthesis ensures organism-wide commitment to reproductive development. Considering that many components of DA signaling are highly conserved, ongoing studies in C. elegans may reveal new aspects of bile acid function and lifespan regulation in mammals.

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

    Science.gov (United States)

    Blaustein, J D

    2012-07-01

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

  7. Status of sex steroid hormone receptors in large bowel cancer

    NARCIS (Netherlands)

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

    1991-01-01

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

  8. Revealing a steroid receptor ligand as a unique PPAR[gamma] agonist

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shengchen; Han, Ying; Shi, Yuzhe; Rong, Hui; Zheng, Songyang; Jin, Shikan; Lin, Shu-Yong; Lin, Sheng-Cai; Li, Yong (Pitt); (Xiamen)

    2012-06-28

    Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) regulates metabolic homeostasis and is a molecular target for anti-diabetic drugs. We report here the identification of a steroid receptor ligand, RU-486, as an unexpected PPAR{gamma} agonist, thereby uncovering a novel signaling route for this steroid drug. Similar to rosiglitazone, RU-486 modulates the expression of key PPAR{gamma} target genes and promotes adipocyte differentiation, but with a lower adipogenic activity. Structural and functional studies of receptor-ligand interactions reveal the molecular basis for a unique binding mode for RU-486 in the PPAR{gamma} ligand-binding pocket with distinctive properties and epitopes, providing the molecular mechanisms for the discrimination of RU-486 from thiazolidinediones (TZDs) drugs. Our findings together indicate that steroid compounds may represent an alternative approach for designing non-TZD PPAR{gamma} ligands in the treatment of insulin resistance.

  9. Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data

    Directory of Open Access Journals (Sweden)

    Fernandez Pedro L

    2005-08-01

    Full Text Available Abstract Background We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. Results Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1 highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. Conclusion Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3. Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer.

  10. Preparation, preliminary screening of new types of steroid conjugates and their activities on steroid receptors

    Czech Academy of Sciences Publication Activity Database

    Jurášek, M.; Džubák, P.; Sedlák, David; Dvořáková, H.; Hajduch, M.; Bartůněk, Petr; Drasar, P.

    2013-01-01

    Roč. 78, č. 3 (2013), s. 356-361 ISSN 0039-128X R&D Projects: GA MŠk(CZ) LC06077; GA ČR(CZ) GAP503/11/0616; GA ČR(CZ) GAP304/10/1951 Institutional support: RVO:68378050 Keywords : click chemistry * steroid ribbons * cytotoxic activity * steroid receptor reporter assay * 2,6-bis((1H-1,2,3-triazol-1-yl)methyl)pyridine Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.716, year: 2013

  11. Synthetic anabolic agents: steroids and nonsteroidal selective androgen receptor modulators.

    Science.gov (United States)

    Thevis, Mario; Schänzer, Wilhelm

    2010-01-01

    The central role of testosterone in the development of male characteristics, as well as its beneficial effects on physical performance and muscle growth, has led to the search for synthetic alternatives with improved pharmacological profiles. Hundreds of steroidal analogs have been prepared with a superior oral bioavailability, which should also possess reduced undesirable effects. However, only a few entered the pharmaceutical market due to severe toxicological incidences that were mainly attributed to the lack of tissue selectivity. Prominent representatives of anabolic-androgenic steroids (AAS) are for instance methyltestosterone, metandienone and stanozolol, which are discussed as model compounds with regard to general pharmacological aspects of synthetic AAS. Recently, nonsteroidal alternatives to AAS have been developed that selectively activate the androgen receptor in either muscle tissue or bones. These so-called selective androgen receptor modulators (SARMs) are currently undergoing late clinical trials (IIb) and will be prohibited by the World Anti-Doping Agency from January 2008. Their entirely synthetic structures are barely related to steroids, but particular functional groups allow for the tissue-selective activation or inhibition of androgen receptors and, thus, the stimulation of muscle growth without the risk of severe undesirable effects commonly observed in steroid replacement therapies. Hence, these compounds possess a high potential for misuse in sports and will be the subject of future doping control assays.

  12. Steroid hormone and epidermal growth factor receptors in meningiomas.

    Science.gov (United States)

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

    1989-11-01

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

  13. Ablation of Steroid Receptor Coactivator-3 resembles the human CACT metabolic myopathy

    OpenAIRE

    York, Brian; Reineke, Erin L.; Sagen, Jørn V.; Nikolai, Bryan C.; Zhou, Suoling; Louet, Jean-Francois; Chopra, Atul R.; Chen, Xian; Reed, Graham; Noebels, Jeffrey; Adesina, Adekunle M.; Yu, Hui; Wong, Lee-Jun C.; Tsimelzon, Anna; Hilsenbeck, Susan

    2012-01-01

    Oxidation of lipid substrates is essential for survival in fasting and other catabolic conditions, sparing glucose for the brain and other glucose-dependent tissues. Here we show Steroid Receptor Coactivator-3 (SRC-3) plays a central role in long chain fatty acid metabolism by directly regulating carnitine/acyl-carnitine translocase (CACT) gene expression. Genetic deficiency of CACT in humans is accompanied by a constellation of metabolic and toxicity phenotypes including hypoketonemia, hypog...

  14. Steroid metabolism and steroid receptors in dimethylbenz(a)anthracene-induced rat mammary tumors

    International Nuclear Information System (INIS)

    Eechaute, W.; de Thibault de Boesinghe, L.; Lacroix, E.

    1983-01-01

    Mammary tumors were induced in rats by treatment with dimethylbenz(a)anthracene. Cytosol receptors for 17 beta-estradiol and progesterone were estimated by means of sucrose density gradient centrifugation, and the metabolism of [ 14 C]progesterone, [ 14 C]testosterone, and 17 beta-[ 14 C]estradiol by minced tumor tissue was studied. The estradiol receptor (ER) and progesterone receptor (PR) levels of the tumors varied considerably from less than 5 to 48 fmol/mg protein for ER and to 243 fmol/mg protein for PR. Considering a receptor level lower than 5 fmol/mg protein to be negative, four groups of tumors were found: ER-negative and PR-negative; ER-positive and PR-negative; ER-negative and PR-positive; ER-positive and PR-positive. In dimethylbenz(a)anthracene-induced tumor tissue, high 5 alpha-reductase and 20 alpha-hydroxysteroid dehydrogenase activities and somewhat lower 3 alpha-hydroxysteroid dehydrogenase and 6 alpha-hydroxylase activities were found. No aromatization was detectable. Steroids, especially estradiol, were also metabolized in a high degree to unextractable metabolites. It was concluded that steroid metabolism of dimethylbenz(a)anthracene-induced rat mammary tumors was not related to the ER and/or PR concentration of tumor tissue

  15. Sex Steroid Hormone Receptor Expression Affects Ovarian Cancer Survival

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  16. Mediator and p300/CBP-Steroid Receptor Coactivator Complexes Have Distinct Roles, but Function Synergistically, during Estrogen Receptor α-Dependent Transcription with Chromatin Templates

    OpenAIRE

    Acevedo, Mari Luz; Kraus, W. Lee

    2003-01-01

    Ligand-dependent transcriptional activation by nuclear receptors involves the recruitment of various coactivators to the promoters of hormone-regulated genes assembled into chromatin. Nuclear receptor coactivators include histone acetyltransferase complexes, such as p300/CBP-steroid receptor coactivator (SRC), as well as the multisubunit mediator complexes (“Mediator”), which may help recruit RNA polymerase II to the promoter. We have used a biochemical approach, including an in vitro chromat...

  17. Developmental reprogramming of reproductive and metabolic dysfunction in sheep: native steroids vs. environmental steroid receptor modulators

    Science.gov (United States)

    Padmanabhan, Vasantha; Sarma, Hiren N.; Savabieasfahani, Mozhgan; Steckler, Teresa L.; Veiga-Lopez, Almudena

    2014-01-01

    The inappropriate programming of developing organ systems by exposure to excess native or environmental steroids, particularly the contamination of our environment and our food sources with synthetic endocrine disrupting chemicals that can interact with steroid receptors, is a major concern. Studies with native steroids have found that in utero exposure of sheep to excess testosterone, an estrogen precursor, results in low birth weight offspring and leads to an array of adult reproductive / metabolic deficits manifested as cycle defects, functional hyperandrogenism, neuroendocrine / ovarian defects, insulin resistance, and hypertension. Furthermore, the severity of reproductive dysfunction is amplified by excess postnatal weight gain. The constellation of adult reproductive and metabolic dysfunction in prenatal testosterone-treated sheep is similar to features seen in women with polycystic ovary syndrome. Prenatal dihydrotestosterone treatment failed to result in similar phenotype suggesting that many effects of prenatal testosterone excess are likely facilitated via aromatization to estradiol. Similarly, exposure to environmental steroid imposters such as bisphenol A (BPA) and methoxychlor (MXC) from days 30-90 of gestation had long-term but differential effects. Exposure of sheep to BPA, which resulted in maternal levels of 30-50 ng/ml BPA, culminated in low birth-weight offspring. These female offspring were hypergonadotropic during early postnatal life and characterized by severely dampened preovulatory LH surges. Prenatal MXC-treated females had normal birth weight and manifested delayed but normal amplitude LH surges. Importantly, the effects of BPA were evident at levels, which approximated twice the highest levels found in human maternal circulation of industrialized nations. These findings provide evidence in support of developmental origin of adult reproductive and metabolic diseases and highlight the risk posed by exposure to environmental endocrine

  18. Sex steroid receptor expression in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Mehrad, Mitra; Trejo Bittar, Humberto E; Yousem, Samuel A

    2017-08-01

    Usual interstitial pneumonia (UIP) is characterized by progressive scarring of the lungs and is associated with high morbidity and mortality despite therapeutic interventions. Sex steroid receptors have been demonstrated to play an important role in chronic lung conditions; however, their significance is unknown in patients with UIP. We retrospectively reviewed 40 idiopathic UIP cases for the expression of hormonal receptors. Forty cases including 10 normal lung, 10 cryptogenic organizing pneumonia, 10 idiopathic organizing diffuse alveolar damage, 7 hypersensitivity pneumonitis, and 3 nonspecific interstitial pneumonitis served as controls. Immunohistochemistry for estrogen receptor α, progesterone receptor (PR), and androgen receptor was performed in all groups. Expression of these receptors was assessed in 4 anatomic/pathologic compartments: alveolar and bronchiolar epithelium, arteries/veins, fibroblastic foci/airspace organization, and old scar. All UIPs (100%) stained positive for PR in myofibroblasts in the scarred areas, whereas among the control cases, only 1 nonspecific interstitial pneumonitis case stained focally positive and the rest were negative. PR was positive in myocytes of the large-sized arteries within the fibrotic areas in 31 cases (77.5%). PR was negative within the alveolar and bronchial epithelium, airspace organization, and center of fibroblastic foci; however, weak PR positivity was noted in the peripheral fibroblasts of the fibroblastic foci where they merged with dense fibrous connective tissue scar. All UIP and control cases were negative for androgen receptor and estrogen receptor α. This is the first study to show the expression of PR within the established fibrotic areas of UIP, indicating that progesterone may have profibrotic effects in UIP patients. Hormonal therapy by targeting PR could be of potential benefit in patients with UIP/IPF. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Steroid receptor profiling of vinclozolin and its primary metabolites

    International Nuclear Information System (INIS)

    Molina-Molina, Jose-Manuel; Hillenweck, Anne; Jouanin, Isabelle; Zalko, Daniel; Cravedi, Jean-Pierre; Fernandez, Mariana-Fatima; Pillon, Arnaud; Nicolas, Jean-Claude; Olea, Nicolas; Balaguer, Patrick

    2006-01-01

    Several pesticides and fungicides commonly used to control agricultural and indoor pests are highly suspected to display endocrine-disrupting effects in animals and humans. Endocrine disruption is mainly caused by the interference of chemicals at the level of steroid receptors: it is now well known that many of these chemicals can display estrogenic effects and/or anti-androgenic effects, but much less is known about the interaction of these compounds with other steroid receptors. Vinclozolin, a dicarboximide fungicide, like its primary metabolites 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1), and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2), is known to bind androgen receptor (AR). Although vinclozolin and its metabolites were characterized as anti-androgens, relatively little is known about their effects on the function of the progesterone (PR), glucocorticoid (GR), mineralocorticoid (MR) or estrogen receptors (ERα and ERβ). Objectives of the study were to determine the ability of vinclozolin and its two primary metabolites to activate AR, PR, GR, MR and ER. For this purpose, we used reporter cell lines bearing luciferase gene under the control of wild type or chimeric Gal4 fusion AR, PR, GR, MR or ERs. We confirmed that all three were antagonists for AR, whereas only M2 was found a partial agonist. Interestingly, M2 was also a PR, GR and MR antagonist (MR >> PR > GR) while vinclozolin was an MR and PR antagonist. Vinclozolin, M1 and M2 were agonists for both ERs with a lower affinity for ERβ. Although the potencies of the fungicide and its metabolites are low when compared to natural ligands, their ability to act via more than one mechanism and the potential for additive or synergistic effect must be taken into consideration in the risk assessment process

  20. Steroid receptor profiling of vinclozolin and its primary metabolites.

    Science.gov (United States)

    Molina-Molina, José-Manuel; Hillenweck, Anne; Jouanin, Isabelle; Zalko, Daniel; Cravedi, Jean-Pierre; Fernández, Mariana-Fátima; Pillon, Arnaud; Nicolas, Jean-Claude; Olea, Nicolás; Balaguer, Patrick

    2006-10-01

    Several pesticides and fungicides commonly used to control agricultural and indoor pests are highly suspected to display endocrine-disrupting effects in animals and humans. Endocrine disruption is mainly caused by the interference of chemicals at the level of steroid receptors: it is now well known that many of these chemicals can display estrogenic effects and/or anti-androgenic effects, but much less is known about the interaction of these compounds with other steroid receptors. Vinclozolin, a dicarboximide fungicide, like its primary metabolites 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1), and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2), is known to bind androgen receptor (AR). Although vinclozolin and its metabolites were characterized as anti-androgens, relatively little is known about their effects on the function of the progesterone (PR), glucocorticoid (GR), mineralocorticoid (MR) or estrogen receptors (ERalpha and ERbeta). Objectives of the study were to determine the ability of vinclozolin and its two primary metabolites to activate AR, PR, GR, MR and ER. For this purpose, we used reporter cell lines bearing luciferase gene under the control of wild type or chimeric Gal4 fusion AR, PR, GR, MR or ERs. We confirmed that all three were antagonists for AR, whereas only M2 was found a partial agonist. Interestingly, M2 was also a PR, GR and MR antagonist (MR>PR>GR) while vinclozolin was an MR and PR antagonist. Vinclozolin, M1 and M2 were agonists for both ERs with a lower affinity for ERbeta. Although the potencies of the fungicide and its metabolites are low when compared to natural ligands, their ability to act via more than one mechanism and the potential for additive or synergistic effect must be taken into consideration in the risk assessment process.

  1. Steroidal Hormone Receptor Expression in Male Breast Cancer

    Directory of Open Access Journals (Sweden)

    Fatemeh Homaei-Shandiz

    2014-01-01

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

  2. Effect of presurgical radiotherapy on the steroid receptor concentrations in primary breast carcinoma

    International Nuclear Information System (INIS)

    Janssens, J. Ph.; Bonte, J.; Drochmans, A.; Mulier, J.; Rutten, J.; Wittevrongel, C.; Loecker, W. de

    1981-01-01

    With age, oestradiol receptor concentrations increased in primary breast carcinoma while age did not seem to affect the progesterone receptor levels. Above the age of 70, all tumours examined proved to be hormone-dependent. Analysis by light microscope did not allow correlation of the receptor-positive tumours to any specific or predominant cellular structure. Presurgical radiotherapy of 20 gray significantly reduced the oestradiol and to an even greater extent the progesterone receptor concentrations in the tumours. Prebioptic irradiation with 8 gray accentuated the inhibition of steroid receptor proteins. This reduction in receptor concentration after radiotherapy should be taken into account when interpreting steroid receptor values. (author)

  3. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qun-Yi; Zhang, Meng [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Hallis, Tina M.; DeRosier, Therese A. [Cell Systems Division, Invitrogen, Madison, WI (United States); Yue, Jian-Min; Ye, Yang [State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Mais, Dale E. [The National Center for Drug Screening, Shanghai (China); MPI Research, Mattawan, MI (United States); Wang, Ming-Wei, E-mail: wangmw@mail.shcnc.ac.cn [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China)

    2010-01-15

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K{sub i} = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  4. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    International Nuclear Information System (INIS)

    Li, Qun-Yi; Zhang, Meng; Hallis, Tina M.; DeRosier, Therese A.; Yue, Jian-Min; Ye, Yang; Mais, Dale E.; Wang, Ming-Wei

    2010-01-01

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K i = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  6. Steroids

    Science.gov (United States)

    ... return of symptoms and sometimes joint pain. SIDE EFFECTS Steroids can cause a wide range of unwanted effects. ... please talk with your doctor. MANAGING COMMON SIDE EFFECTS WEIGHT GAIN AND INCREASED BLOOD SUGAR LEVELS Steroids increase the appetite and often cause weight gain. ...

  7. Age related changes in steroid receptors on cultured lung fibroblasts

    International Nuclear Information System (INIS)

    Barile, F.A.; Bienkowski, R.S.

    1986-01-01

    The number of high affinity glucocorticoid receptors (Ro) on human fetal lung fibroblasts decreases as the cells age in vitro, and it has been suggested that these cell systems may be useful models of age-related changes in vivo. They examined the relation between change in Ro with in vitro aging and donor age. Confluent monolayers of lung fibroblasts at various population doubling levels (PDL), were incubated with ( 3 H)-dexamethasone (( 3 H)Dex) either alone or with excess (.01 mM) Dex. Specific binding was calculated as the difference between radioactivity in cells incubated with and without unlabeled Dex; Scatchard plots were used to analyze the data. Ro, measured as fmol ( 3 H)Dex/10 6 cells, for two lines of human fetal cells (HFL-1 and MRC-5) decreased with increasing age in vitro. However, human newborn (CRL-1485) and adult (CCL-201) cells and fetal rabbit cells (FAB-290), showed increases in Ro with continuous passage. For each cell line, the affinity constant (K/sub d/) did not change significantly with passage. They conclude that the direction of changes in steroid receptor levels on cells aging in vitro is influenced by donor age and species. Caution should be used in applying results obtained from model systems to aging organisms

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  9. Identification of steroid-binding and phosphorylated sites within the glucocorticoid receptor

    International Nuclear Information System (INIS)

    Smith, L.I.

    1989-01-01

    The primary goal of these studies was to localize the steroid-binding and phosphorylated sites of the glucocorticoid receptor. The synthetic steroid, dexamethasone 21-mesylate (DM) forms a covalent thioether bond via the sulfhydryl group of a cysteine residue in the receptor. To determine the covalent site of attachment of this ligand, receptors in WEHI-7 mouse thymoma cells were labeled with [ 3 H]DM and purified with a monoclonal antibody. The receptor was completely digested with trypsin and a single peptide covalently labeled with steroid identified by reversed-phase HPLC. This peptide was analyzed by automated Edman degradation to determine the location of the steroid-labeled residue. A similar analysis was performed on an overlapping peptide produced by Staphylococcus aureus protease digestion. Analysis of tryptic peptides from receptors labeled with both [ 3 H]DM and L-[ 35 S]methionine indicated that this peptide contained methionine. These analyses, coupled with the published amino acid sequence of the receptor, identified Cysteine-644 in the steroid-binding domain of the mouse glucocorticoid receptor as the residue involved in covalent steroid-binding. A synthetic peptide representing amino acids 640-650 of the mouse receptor was prepared and analyzed to confirm the identification. These biochemical studies represent a direct demonstration of an amino acid important in receptor function. It has been proposed that the receptor functions through a phosphorylation-dephosphorylation cycle to explain the dependence of hormone binding capacity upon cellular ATP. The glucocorticoid receptor has been shown to be a phosphoprotein. As an initial step to identifying a role of phosphorylation in receptor action, phosphorylated sites within the functional domains of the protein were identified

  10. Role of sex steroid receptors in pathobiology of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Mamta Kalra; Jary Mayes; Senait Assefa; Anil K Kaul; Rashmi Kaul

    2008-01-01

    The striking gender disparity observed in the incidence of hepatocellular carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise role of sex hormones and the significance of their receptors in HCC still remain poorly understood and perhaps contribute to current controversies about the potential use of hormonal therapy in HCC. A comprehensive review of the existing literature revealed several shortcomings associated with the studies on estrogen receptor (ER) and androgen receptor (AR) in normal liver and HCC. These shortcomings include the use of less sensitive receptor ligand binding assays and immunohistochemistry studies for ERα alone until 1996 when ERβ isoform was identified. The animal models of HCC utilized for studies were primarily based on chemical-induced hepatocarcinogenesis with less similarity to virus-induced HCC pathogenesis. However, recent in vitro studies in hepatoma cells provide newer insights for hormonal regulation of key cellular processes including interaction of ER and AR with viral proteins. In light of the above facts, there is an urgent need for a detailed investigation of sex hormones and their receptors in normal liver and HCC. In this review, we systematically present the information currently available on androgens, estrogens and their receptors in normal liver and HCC obtained from in vitro, in vivo experimental models and clinical studies. This information will direct future basic and clinical research to bridge the gap in knowledge to explore the therapeutic potential of hormonal therapy in HCC. 2008 The WJG Press. All rights reserved.

  11. Cyclodextrin dimers as receptor molecules for steroid sensors

    NARCIS (Netherlands)

    de Jong, M.R.; Engbersen, Johannes F.J.; Huskens, Jurriaan; Reinhoudt, David

    2000-01-01

    The dansyl-modified dimer 9 complexes strongly with the steroidal bile salts. Relative to native -cyclodextrin, the binding of cholate (1 a) and deoxycholate (1 b) salts is especially enhanced. These steroids bind exclusively in a 1:1 fashion. For other bile salts (1 c-1 e) both 1:1 and 1:2

  12. Steroids

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Steroids KidsHealth ... athletes, and why not? It's fun to think about being the very best in your favorite sport, not to mention earning a big salary. But ...

  13. Steroids

    Science.gov (United States)

    ... of aggression and hostility Increased risk of heart disease, liver damage Addiction Read More about Steroids Be Informed. Search for information about a drug View Popular Searches: POT , HEROIN , METH Previous Pause Next Marijuana Featured Articles What You Should Know About Marijuana ...

  14. Effects of sex steroids on expression of genes regulating growth-related mechanisms in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Cleveland, Beth M; Weber, Gregory M

    2015-05-15

    Effects of a single injection of 17β-estradiol (E2), testosterone (T), or 5β-dihydrotestosterone (DHT) on expression of genes central to the growth hormone (GH)/insulin-like growth factor (IGF) axis, muscle-regulatory factors, transforming growth factor-beta (TGFβ) superfamily signaling cascade, and estrogen receptors were determined in rainbow trout (Oncorhynchus mykiss) liver and white muscle tissue. In liver in addition to regulating GH sensitivity and IGF production, sex steroids also affected expression of IGF binding proteins, as E2, T, and DHT increased expression of igfbp2b and E2 also increased expression of igfbp2 and igfbp4. Regulation of this system also occurred in white muscle in which E2 increased expression of igf1, igf2, and igfbp5b1, suggesting anabolic capacity may be maintained in white muscle in the presence of E2. In contrast, DHT decreased expression of igfbp5b1. DHT and T decreased expression of myogenin, while other muscle regulatory factors were either not affected or responded similarly for all steroid treatments. Genes within the TGFβ superfamily signaling cascade responded to steroid treatment in both liver and muscle, suggesting a regulatory role for sex steroids in the ability to transmit signals initiated by TGFβ superfamily ligands, with a greater number of genes responding in liver than in muscle. Estrogen receptors were also regulated by sex steroids, with era1 expression increasing for all treatments in muscle, but only E2- and T-treatment in liver. E2 reduced expression of erb2 in liver. Collectively, these data identify how physiological mechanisms are regulated by sex steroids in a manner that promotes the disparate effects of androgens and estrogens on growth in salmonids. Published by Elsevier Inc.

  15. Two panels of steroid receptor luciferase reporter cell lines for compound profiling

    Czech Academy of Sciences Publication Activity Database

    Sedlák, David; Paguio, A.; Bartůněk, Petr

    2011-01-01

    Roč. 14, č. 2 (2011), s. 248-266 ISSN 1386-2073 R&D Projects: GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z50520514 Keywords : nuclear hormone receptor * steroid receptor * cell-based luciferase reporter assay Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.785, year: 2011

  16. Glucocorticoid Regulation of the Vitamin D Receptor

    Science.gov (United States)

    Hidalgo, Alejandro A.; Trump, Donald L.; Johnson, Candace S.

    2010-01-01

    Many studies indicate calcitriol has potent anti-tumor activity in different types of cancers. However, high levels of vitamin D can produce hypercalcemia in some patients. Glucocorticoids are used to ameliorate hypercalcemia and to enhance calcitriol anti-tumor activity. Calcitriol in combination with the glucocorticoid dexamethasone (Dex) increased vitamin D receptor (VDR) protein levels and ligand binding in squamous cell carcinoma VII (SCC). In this study we found that both calcitriol and Dex induce VDR- and glucocorticoid receptor (GR)-mediated transcription respectively, indicating both hormone receptors are active in SCC. Pre-treatment with Dex increases VDR-mediated transcription at the human CYP24A1 promoter. Whereas, pre-treatment with other steroid hormones, including dihydrotestosterone and R1881, has no effect on VDR-mediated transcription. Real-time PCR indicates treatment with Dex increases Vdr transcripts in a time-dependent manner, suggesting Dex may directly regulate expression of Vdr. Numerous putative glucocorticoid response elements (GREs) were found in the Vdr gene. Chromatin immunoprecipitation (ChIP) assay demonstrated GR binding at several putative GREs located within the mouse Vdr gene. However, none of the putative GREs studied increase GR-mediated transcription in luciferase reporter assays. In an attempt to identify the response element responsible for Vdr transcript regulation, future studies will continue to analyze newly identified GREs more distal from the Vdr gene promoter. PMID:20398752

  17. Identification of hormone-interacting amino acid residues within the steroid-binding domain of the glucocorticoid receptor in relation to other steroid hormone receptors

    International Nuclear Information System (INIS)

    Carlstedt-Duke, J.; Stroemstedt, P.E.; Persson, B.; Cederlund, E.; Gustafsson, J.A.; Joernvall, H.

    1988-01-01

    Purified rat liver glucocorticoid receptor was covalently charged with [ 3 H]glucocorticoid by photoaffinity labeling (UV irradiation of [ 3 H]triamcinolone acetonide-glucocorticoid receptor) or affinity labeling (incubation with [ 3 H]dexamethasone mesylate). After labeling, separate samples of the denatured receptor were cleaved with trypsin (directly or after prior succinylation), chymotrypsin, and cyanogen bromide. Labeled residues in the peptides obtained were identified by radiosequence analysis. The peaks of radioactivity corresponded to Met-622 and Cys-754 after photoaffinity labeling with [ 3 H]triamcinolone acetonide and Cys-656 after affinity labeling with [ 3 H]dexamethasone mesylate. The labeled residues are all positioned within hydrophobic segments of the steroid-binding domain. The patterns of hydropathy and secondary structure for the glucocorticoid receptor are highly similar to those for the progestin receptor and similar but less so to those for the estrogen receptor and to those for c-erb A

  18. Steroid hormone regulation of EMP2 expression and localization in the endometrium

    Directory of Open Access Journals (Sweden)

    Williams Carmen J

    2008-04-01

    Full Text Available Abstract Background The tetraspan protein epithelial membrane protein-2 (EMP2, which mediates surface display of diverse proteins, is required for endometrial competence in blastocyst implantation, and is uniquely correlated with poor survival from endometrial adenocarcinoma tumors. Because EMP2 is differentially expressed in the various stages of the murine and human estrous cycle, we tested the hypothesis that the steroid hormones progesterone and estrogen influence EMP2 expression and localization. Methods Frozen human proliferative and secretory endometrium were collected and analyzed for EMP2 expression using SDS-PAGE/Western blot analysis. The response of EMP2 to progesterone and estradiol was determined using a combination of real-time PCR, SDS-PAGE/Western blot analysis, and confocal immunofluorescence in the human endometrial carcinoma cell line RL95-2. To confirm the in vitro results, ovariectomized mice were treated with progesterone or estradiol, and EMP2 expression was analyzed using immunohistochemistry. Results Within normal human endometrium, EMP2 expression is upregulated in the secretory phase relative to the proliferative phase. To understand the role of steroid hormones on EMP2 expression, we utilized RL95-2 cells, which express both estrogen and progesterone receptors. In RL95-2 cells, both estradiol and progesterone induced EMP2 mRNA expression, but only progesterone induced EMP2 protein expression. To compare steroid hormone regulation of EMP2 between humans and mice, we analyzed EMP2 expression in ovarectomized mice. Similar to results observed in humans, progesterone upregulated endometrial EMP2 expression and induced EMP2 translocation to the plasma membrane. Estradiol did not promote translocation to the cell surface, but moderately induced EMP2 expression in cytoplasmic compartments in vivo. Conclusion These findings suggest that targeting of EMP2 to specific locations under the influence of these steroid hormones may

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  1. Testosterone regulation of sex steroid-related mRNAs and dopamine-related mRNAs in adolescent male rat substantia nigra

    Directory of Open Access Journals (Sweden)

    Purves-Tyson Tertia D

    2012-08-01

    Full Text Available Abstract Background Increased risk of schizophrenia in adolescent males indicates that a link between the development of dopamine-related psychopathology and testosterone-driven brain changes may exist. However, contradictions as to whether testosterone increases or decreases dopamine neurotransmission are found and most studies address this in adult animals. Testosterone-dependent actions in neurons are direct via activation of androgen receptors (AR or indirect by conversion to 17β-estradiol and activation of estrogen receptors (ER. How midbrain dopamine neurons respond to sex steroids depends on the presence of sex steroid receptor(s and the level of steroid conversion enzymes (aromatase and 5α-reductase. We investigated whether gonadectomy and sex steroid replacement could influence dopamine levels by changing tyrosine hydroxylase (TH protein and mRNA and/or dopamine breakdown enzyme mRNA levels [catechol-O-methyl transferase (COMT and monoamine oxygenase (MAO A and B] in the adolescent male rat substantia nigra. We hypothesized that adolescent testosterone would regulate sex steroid signaling through regulation of ER and AR mRNAs and through modulation of aromatase and 5α-reductase mRNA levels. Results We find ERα and AR in midbrain dopamine neurons in adolescent male rats, indicating that dopamine neurons are poised to respond to circulating sex steroids. We report that androgens (T and DHT increase TH protein and increase COMT, MAOA and MAOB mRNAs in the adolescent male rat substantia nigra. We report that all three sex steroids increase AR mRNA. Differential action on ER pathways, with ERα mRNA down-regulation and ERβ mRNA up-regulation by testosterone was found. 5α reductase-1 mRNA was increased by AR activation, and aromatase mRNA was decreased by gonadectomy. Conclusions We conclude that increased testosterone at adolescence can shift the balance of sex steroid signaling to favor androgenic responses through promoting

  2. Steroid-binding receptors in fungi: implication for systemic mycoses

    Directory of Open Access Journals (Sweden)

    Mostafa chadeganipour

    2015-03-01

    Full Text Available It has been shown that some of the mycotic infections especially systemic mycoses show increased male susceptibility and some steroids have been known to influence the immune response. Researchers found that some fungi including yeasts use "message molecules" including hormones to elicit certain responses, especially in the sexual cycle, but until recently no evidence was available to link specific hormonal evidence to this pronounced sex ratio. More evidence needed to demonstrate that a steroid (s might in some manner influence the pathogenicity of the fungus in vivo. Therefore, the aim of this review paper is to shed some light on this subject along with effort to make mycologists more aware of this research as a stimulus for the explore of new ideas and design further research in this area of medical mycology.

  3. Steroids induce acetylcholine receptors on cultured human muscle: Implications for myasthenia gravis

    International Nuclear Information System (INIS)

    Kaplan, I.; Blakely, B.T.; Pavlath, G.K.; Travis, M.; Blau, H.M.

    1990-01-01

    Antibodies to the acetylcholine receptor (AChR), which are diagnostic of the human autoimmune disease myasthenia gravis, block AChR function and increase the rate of AChR degradation leading to impaired neuromuscular transmission. Steroids are frequently used to alleviate symptoms of muscle fatigue and weakness in patients with myasthenia gravis because of their well-documented immunosuppressive effects. The authors show here that the steroid dexamethasone significantly increases total surface AChRs on cultured human muscle exposed to myasthenia gravis sera. The results suggest that the clinical improvement observed in myasthenic patients treated with steroids is due not only to an effect on the immune system but also a direct effect on muscle. They propose that the identification and development of pharmacologic agents that augment receptors and other proteins that are reduced by human genetic or autoimmune disease will have broad therapeutic applications

  4. Steroids induce acetylcholine receptors on cultured human muscle: Implications for myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, I.; Blakely, B.T.; Pavlath, G.K.; Travis, M.; Blau, H.M. (Stanford Univ. School of Medicine, CA (USA))

    1990-10-01

    Antibodies to the acetylcholine receptor (AChR), which are diagnostic of the human autoimmune disease myasthenia gravis, block AChR function and increase the rate of AChR degradation leading to impaired neuromuscular transmission. Steroids are frequently used to alleviate symptoms of muscle fatigue and weakness in patients with myasthenia gravis because of their well-documented immunosuppressive effects. The authors show here that the steroid dexamethasone significantly increases total surface AChRs on cultured human muscle exposed to myasthenia gravis sera. The results suggest that the clinical improvement observed in myasthenic patients treated with steroids is due not only to an effect on the immune system but also a direct effect on muscle. They propose that the identification and development of pharmacologic agents that augment receptors and other proteins that are reduced by human genetic or autoimmune disease will have broad therapeutic applications.

  5. PET Imaging of Steroid Receptor Expression in Breast and Prostate Cancer

    NARCIS (Netherlands)

    Hospers, G. A. P.; Helmond, F. A.; Dierckx, R. A.; de Vries, Emma; de Vries, Erik

    2008-01-01

    The vast majority of breast and prostate cancers express specific receptors for steroid hormones, which play a pivotal role in tumor progression. Because of the efficacy of endocrine therapy combined with its relatively mild side-effects, this intervention has nowadays become the treatment of choice

  6. Differences in postmortem stability of sex steroid receptor immunoreactivity in rat brain

    NARCIS (Netherlands)

    Fodor, Mariann; van Leeuwen, Fred W.; Swaab, Dick F.

    2002-01-01

    Difficulties in demonstrating sex steroid receptors in the human brain by immunohistochemistry (IHC) may depend on postmortem delay and a long fixation time. The effect of different postmortem times was therefore studied in rat brain kept in the skull at room temperature for 0, 6, or 24 hr after

  7. IL-7 Receptor Mutations and Steroid Resistance in Pediatric T cell Acute Lymphoblastic Leukemia: A Genome Sequencing Study.

    Directory of Open Access Journals (Sweden)

    Yunlei Li

    2016-12-01

    -type and mutant IL7R signaling molecules in two steroid-sensitive T-ALL cell lines (SUPT1 and P12 Ichikawa cells using inducible lentiviral expression constructs. We found that expressing mutant IL7R, JAK1, or NRAS, or wild-type NRAS or AKT, specifically induced steroid resistance without affecting sensitivity to vincristine or L-asparaginase. In contrast, wild-type IL7R, JAK1, and JAK3, as well as mutant JAK3 and mutant AKT, had no effect. We then performed a functional study to examine the mechanisms underlying steroid resistance and found that, rather than changing the steroid receptor's ability to activate downstream targets, steroid resistance was associated with strong activation of MEK-ERK and AKT, downstream components of the IL7R signaling pathway, thereby inducing a robust antiapoptotic response by upregulating MCL1 and BCLXL expression. Both the MEK-ERK and AKT pathways also inactivate BIM, an essential molecule for steroid-induced cell death, and inhibit GSK3B, an important regulator of proapoptotic BIM. Importantly, treating our cell lines with IL7R signaling inhibitors restored steroid sensitivity. To address clinical relevance, we treated primary T-ALL cells obtained from 11 patients with steroids either alone or in combination with IL7R signaling inhibitors; we found that including a MEK, AKT, mTOR, or dual PI3K/mTOR inhibitor strongly increased steroid-induced cell death. Therefore, combining these inhibitors with steroid treatment may enhance steroid sensitivity in patients with ALL. The main limitation of our study was the modest cohort size, owing to the very low incidence of T-ALL.Using an unbiased sequencing approach, we found that specific mutations in IL7R signaling molecules underlie steroid resistance in T-ALL. Future prospective clinical studies should test the ability of inhibitors of MEK, AKT, mTOR, or PI3K/mTOR to restore or enhance steroid sensitivity and improve clinical outcome.

  8. Ablation of steroid receptor coactivator-3 resembles the human CACT metabolic myopathy.

    Science.gov (United States)

    York, Brian; Reineke, Erin L; Sagen, Jørn V; Nikolai, Bryan C; Zhou, Suoling; Louet, Jean-Francois; Chopra, Atul R; Chen, Xian; Reed, Graham; Noebels, Jeffrey; Adesina, Adekunle M; Yu, Hui; Wong, Lee-Jun C; Tsimelzon, Anna; Hilsenbeck, Susan; Stevens, Robert D; Wenner, Brett R; Ilkayeva, Olga; Xu, Jianming; Newgard, Christopher B; O'Malley, Bert W

    2012-05-02

    Oxidation of lipid substrates is essential for survival in fasting and other catabolic conditions, sparing glucose for the brain and other glucose-dependent tissues. Here we show Steroid Receptor Coactivator-3 (SRC-3) plays a central role in long chain fatty acid metabolism by directly regulating carnitine/acyl-carnitine translocase (CACT) gene expression. Genetic deficiency of CACT in humans is accompanied by a constellation of metabolic and toxicity phenotypes including hypoketonemia, hypoglycemia, hyperammonemia, and impaired neurologic, cardiac and skeletal muscle performance, each of which is apparent in mice lacking SRC-3 expression. Consistent with human cases of CACT deficiency, dietary rescue with short chain fatty acids drastically attenuates the clinical hallmarks of the disease in mice devoid of SRC-3. Collectively, our results position SRC-3 as a key regulator of β-oxidation. Moreover, these findings allow us to consider platform coactivators such as the SRCs as potential contributors to syndromes such as CACT deficiency, previously considered as monogenic. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Neurobeachin regulates neurotransmitter receptor trafficking to synapses

    NARCIS (Netherlands)

    Nair, R.; Lauks, J.; Jung, S; Cooke, N.E.; de Wit, H.; Brose, N.; Kilimann, M.W.; Verhage, M.; Rhee, J.

    2013-01-01

    The surface density of neurotransmitter receptors at synapses is a key determinant of synaptic efficacy. Synaptic receptor accumulation is regulated by the transport, postsynaptic anchoring, and turnover of receptors, involving multiple trafficking, sorting, motor, and scaffold proteins. We found

  10. IL-7 Receptor Mutations and Steroid Resistance in Pediatric T cell Acute Lymphoblastic Leukemia: A Genome Sequencing Study

    Science.gov (United States)

    Stubbs, Andrew P.; Vroegindeweij, Eric M.; Smits, Willem K.; van Marion, Ronald; Dinjens, Winand N. M.; Horstmann, Martin; Kuiper, Roland P.; Zaman, Guido J. R.; van der Spek, Peter J.; Pieters, Rob; Meijerink, Jules P. P.

    2016-01-01

    Background Pediatric acute lymphoblastic leukemia (ALL) is the most common childhood cancer and the leading cause of cancer-related mortality in children. T cell ALL (T-ALL) represents about 15% of pediatric ALL cases and is considered a high-risk disease. T-ALL is often associated with resistance to treatment, including steroids, which are currently the cornerstone for treating ALL; moreover, initial steroid response strongly predicts survival and cure. However, the cellular mechanisms underlying steroid resistance in T-ALL patients are poorly understood. In this study, we combined various genomic datasets in order to identify candidate genetic mechanisms underlying steroid resistance in children undergoing T-ALL treatment. Methods and Findings We performed whole genome sequencing on paired pre-treatment (diagnostic) and post-treatment (remission) samples from 13 patients, and targeted exome sequencing of pre-treatment samples from 69 additional T-ALL patients. We then integrated mutation data with copy number data for 151 mutated genes, and this integrated dataset was tested for associations of mutations with clinical outcomes and in vitro drug response. Our analysis revealed that mutations in JAK1 and KRAS, two genes encoding components of the interleukin 7 receptor (IL7R) signaling pathway, were associated with steroid resistance and poor outcome. We then sequenced JAK1, KRAS, and other genes in this pathway, including IL7R, JAK3, NF1, NRAS, and AKT, in these 69 T-ALL patients and a further 77 T-ALL patients. We identified mutations in 32% (47/146) of patients, the majority of whom had a specific T-ALL subtype (early thymic progenitor ALL or TLX). Based on the outcomes of these patients and their prednisolone responsiveness measured in vitro, we then confirmed that these mutations were associated with both steroid resistance and poor outcome. To explore how these mutations in IL7R signaling pathway genes cause steroid resistance and subsequent poor outcome, we

  11. Regulation of phase I and phase II steroid metabolism enzymes by PPARα activators

    International Nuclear Information System (INIS)

    Fan Liqun; You Li; Brown-Borg, Holly; Brown, Sherri; Edwards, Robert J.; Corton, J. Christopher

    2004-01-01

    Peroxisome proliferators (PP) are a large class of structurally diverse chemicals that mediate their effects in the liver mainly through the peroxisome proliferator-activated receptor α (PPARα). Exposure to some PP results in alterations of steroid levels that may be mechanistically linked to adverse effects in reproductive organs. We hypothesized that changes in steroid levels after PP exposure are due to alterations in the levels of P450 enzymes that hydroxylate testosterone and estrogen. In testosterone hydroxylase assays, exposure to the PP, WY-14,643 (WY), gemfibrozil or di-n-butyl phthalate (DBP) led to compound-specific increases in 6β and 16β-testosterone and androstenedione hydroxylase activities and decreases in 16α, 2α-hydroxylase activities by all three PP. The decreases in 16α and 2α-testosterone hydroxylase activity can be attributed to a 2α and 16α- testosterone hydroxylase, CYP2C11, which we previously showed was dramatically down-regulated in these same tissues (Corton et al., 1998; Mol. Pharmacol. 54, 463-473). To explain the increases in 6β- and 16β-testosterone hydroxylase activities, we examined the expression of P450 family members known to carry out these functions. Alterations in the 6β-testosterone hydroxylases CYP3A1, CYP3A2 and the 16β-testosterone hydroxylase, CYP2B1 were observed after exposure to some PP. The male-specific estrogen sulfotransferase was down-regulated in rat liver after exposure to all PP. The mouse 6β-testosterone hydroxylase, Cyp3a11 was down-regulated by WY in wild-type but not PPARα-null mice. In contrast, DEHP increased Cyp3a11 in both wild-type and PPARα-null mice. These studies demonstrate that PP alter the expression and activity of a number of enzymes which regulate levels of sex steroids. The changes in these enzymes may help explain why exposure to some PP leads to adverse effects in endocrine tissues that produce or are the targets of sex hormones

  12. Immunohistochemical localization of steroid receptor coactivators in chondrosarcoma: an in vivo tissue microarray study.

    Science.gov (United States)

    Li, Wei; Fu, Jingshu; Bian, Chen; Zhang, Jiqiang; Xie, Zhao

    2014-12-01

    Chondrosarcoma is the second most common type of primary bone malignancy following up osteosarcoma, characterized by resistance to conventional chemotherapeutic agents and radiation regimens. The p160 family members steroid receptor coactivator-1 and -3 (SRC-1 and SRC-3) have been implied in the regulation of cancer growth, migration, invasion, metastasis and chemotherapeutic resistance; but we still lack detailed information about the levels of SRCs in chondrosarcoma. In this study, expression of SRC-1 and SRC-3 in chondrosarcoma was examined by immunohistochemistry with tissue microarrays; the four score system (0, 1, 2 and 3) was used to evaluate the staining. The results showed that there were no gender-, site- or age-differences regarding the expression of SRC-1 or SRC-3 (p>0.05); organ (bone or cartilage) -differences were only detected for SRC-1 but not SRC-3 (pchondrosarcoma, may be novel targets for the prognosis and/or treatment of chondrosarcoma, would have opened a new avenue and established foundation for studying chondrosarcoma. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Suppression of Rapidly Progressive Mouse Glomerulonephritis with the Non-Steroidal Mineralocorticoid Receptor Antagonist BR-4628.

    Science.gov (United States)

    Ma, Frank Y; Han, Yingjie; Nikolic-Paterson, David J; Kolkhof, Peter; Tesch, Greg H

    2015-01-01

    Steroidal mineralocorticoid receptor antagonists (MRAs) are effective in the treatment of kidney disease; however, the side effect of hyperkalaemia, particularly in the context of renal impairment, is a major limitation to their clinical use. Recently developed non-steroidal MRAs have distinct characteristics suggesting that they may be superior to steroidal MRAs. Therefore, we explored the benefits of a non-steroidal MRA in a model of rapidly progressive glomerulonephritis. Accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was induced in groups of C57BL/6J mice which received no treatment, vehicle or a non-steroidal MRA (BR-4628, 5mg/kg/bid) from day 0 until being killed on day 15 of disease. Mice were examined for renal injury. Mice with anti-GBM glomerulonephritis which received no treatment or vehicle developed similar disease with severe albuminuria, impaired renal function, glomerular tuft damage and crescents in 40% of glomeruli. In comparison, mice which received BR-4628 displayed similar albuminuria, but had improved renal function, reduced severity of glomerular tuft lesions and a 50% reduction in crescents. The protection seen in BR-4628 treated mice was associated with a marked reduction in glomerular macrophages and T-cells and reduced kidney gene expression of proinflammatory (CCL2, TNF-α, IFN-γ) and profibrotic molecules (collagen I, fibronectin). In addition, treatment with BR-4626 did not cause hyperkalaemia or increase urine Na+/K+ excretion (a marker of tubular dysfunction). The non-steroidal MRA (BR-4628) provided substantial suppression of mouse crescentic glomerulonephritis without causing tubular dysfunction. This finding warrants further investigation of non-steroidal MRAs as a therapy for inflammatory kidney diseases.

  14. Suppression of Rapidly Progressive Mouse Glomerulonephritis with the Non-Steroidal Mineralocorticoid Receptor Antagonist BR-4628.

    Directory of Open Access Journals (Sweden)

    Frank Y Ma

    Full Text Available Steroidal mineralocorticoid receptor antagonists (MRAs are effective in the treatment of kidney disease; however, the side effect of hyperkalaemia, particularly in the context of renal impairment, is a major limitation to their clinical use. Recently developed non-steroidal MRAs have distinct characteristics suggesting that they may be superior to steroidal MRAs. Therefore, we explored the benefits of a non-steroidal MRA in a model of rapidly progressive glomerulonephritis.Accelerated anti-glomerular basement membrane (GBM glomerulonephritis was induced in groups of C57BL/6J mice which received no treatment, vehicle or a non-steroidal MRA (BR-4628, 5mg/kg/bid from day 0 until being killed on day 15 of disease. Mice were examined for renal injury.Mice with anti-GBM glomerulonephritis which received no treatment or vehicle developed similar disease with severe albuminuria, impaired renal function, glomerular tuft damage and crescents in 40% of glomeruli. In comparison, mice which received BR-4628 displayed similar albuminuria, but had improved renal function, reduced severity of glomerular tuft lesions and a 50% reduction in crescents. The protection seen in BR-4628 treated mice was associated with a marked reduction in glomerular macrophages and T-cells and reduced kidney gene expression of proinflammatory (CCL2, TNF-α, IFN-γ and profibrotic molecules (collagen I, fibronectin. In addition, treatment with BR-4626 did not cause hyperkalaemia or increase urine Na+/K+ excretion (a marker of tubular dysfunction.The non-steroidal MRA (BR-4628 provided substantial suppression of mouse crescentic glomerulonephritis without causing tubular dysfunction. This finding warrants further investigation of non-steroidal MRAs as a therapy for inflammatory kidney diseases.

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

    Directory of Open Access Journals (Sweden)

    Cline J Mark

    2003-02-01

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

  16. Molecular characterization of kiss2 and differential regulation of reproduction-related genes by sex steroids in the hypothalamus of half-smooth tongue sole (Cynoglossus semilaevis).

    Science.gov (United States)

    Wang, Bin; Liu, Quan; Liu, Xuezhou; Xu, Yongjiang; Song, Xuesong; Shi, Bao

    2017-11-01

    Kisspeptin (Kiss) plays a critical role in mediating gonadal steroid feedback to the gonadotropin-releasing hormone (GnRH) neurons in mammals. However, little information regarding the regulation of kisspeptin gene by sex steroids is available in teleosts. In this study, we examined the direct actions of estradiol (E2) and testosterone (T) on hypothalamic expression of kisspeptin and other key factors involved in reproductive function of half-smooth tongue sole. As a first step, a partial-length cDNA of kiss2 was identified from the brain of tongue sole and kiss2 transcript levels were shown to be widely expressed in various tissues, notably in the ovary. Then, the actions of sex steroids on kiss2 and other reproduction-related genes were evaluated using a primary hypothalamus culture system. Our results showed that neither kiss2 nor its receptor kiss2r mRNA levels were significantly altered by sex steroids. Moreover, sex steroids did not modify hypothalamic expression of gonadotropin-inhibitory hormone (gnih) and its receptor gnihr mRNAs, either. However, E2 markedly stimulated both gnrh2 and gnrh3 mRNAs levels. Overall, this study provides insights into the role of sex steroids in the reproductive function of Pleuronectiform teleosts. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Steroid receptor coactivators 1 and 2 mediate fetal-to-maternal signaling that initiates parturition

    OpenAIRE

    Gao, Lu; Rabbitt, Elizabeth H.; Condon, Jennifer C.; Renthal, Nora E.; Johnston, John M.; Mitsche, Matthew A.; Chambon, Pierre; Xu, Jianming; O’Malley, Bert W.; Mendelson, Carole R.

    2015-01-01

    The precise mechanisms that lead to parturition are incompletely defined. Surfactant protein-A (SP-A), which is secreted by fetal lungs into amniotic fluid (AF) near term, likely provides a signal for parturition; however, SP-A–deficient mice have only a relatively modest delay (~12 hours) in parturition, suggesting additional factors. Here, we evaluated the contribution of steroid receptor coactivators 1 and 2 (SRC-1 and SRC-2), which upregulate SP-A transcription, to the parturition process...

  18. Tritium-labelled steroids, their preparation and application for the determination and location of steroid tissular hormone receptors

    International Nuclear Information System (INIS)

    Jouquey, Alain; Raynaud, J.P.

    1977-01-01

    A product is prepared by the action of tritiated methanol on 11β-hydroxy-estra-4,9-dien-3,17-dione, the action of an aromatisation agent on the (11β)-11-methoxy- 3 H 3 -estra-4,9-dien-3,17-dione formed and the action of an ethynylation agent on the resulting (11β)-3-hydroxy-11-methoxy- 3 H 3 -estra-1,3,5(10)-trien-17-one giving (11β, 17α)-11-methoxy- 3 H 3 -19-norpregna-1,3,5(10)-trien-20-yne-3,17 diol, the free hydroxyl function or functions of this product may be etherified or esterified as the case may be. The tritiated methanol acts in the presence of perchloric acid. The aromatisation agent is palladium hydroxide and the operation is carried out in methanol. The ethynylation agent is acetylene and the reaction takes place in the presence of sodium t-amylate in toluene. This product allows the study and determination of the estrogen specific receptor present in the tissue cells of target organs for the action of estrogens: uterus, vagina, hypophysis, hypothalamus and tumours, of the breast and prostate for example, in both animals and man. Not being fixed by the plasma proteins binding such hormones as testosterone and estradiol in women the product is an ideal indicator of the tissular estrogen receptor with which it forms a complex of strong affinity and great stability, especially since it interacts with the tissular receptors of no other steroid hormone groups (glucocorticoids, androgen or progestogen mineralocorticosteroids) [fr

  19. Structural characteristics of anabolic androgenic steroids contributing to binding to the androgen receptor and to their anabolic and androgenic activities. Applied modifications in the steroidal structure.

    Science.gov (United States)

    Fragkaki, A G; Angelis, Y S; Koupparis, M; Tsantili-Kakoulidou, A; Kokotos, G; Georgakopoulos, C

    2009-02-01

    Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone introduced for therapeutic purposes providing enhanced anabolic potency with reduced androgenic effects. Androgens mediate their action through their binding to the androgen receptor (AR) which is mainly expressed in androgen target tissues, such as the prostate, skeletal muscle, liver and central nervous system. This paper reviews some of the wide spectrum of testosterone and synthetic AAS structure modifications related to the intended enhancement in anabolic activity. The structural features of steroids necessary for effective binding to the AR and those which contribute to the stipulation of the androgenic and anabolic activities are also presented.

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

    Science.gov (United States)

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

    2010-01-01

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

  1. Expression of steroid receptors in ameloblasts during amelogenesis in rat incisors

    Directory of Open Access Journals (Sweden)

    Sophia Houari

    2016-11-01

    Full Text Available Endocrine disrupting chemicals (EDCs play a part in the modern burst of diseases and interfere with the steroid hormone axis. Bisphenol A (BPA, one of the most active and widely used EDCs, affects ameloblast functions, leading to an enamel hypomineralization pattern similar to that of Molar Incisor Hypomineralization (MIH. In order to explore the molecular pathways stimulated by BPA during amelogenesis, we thoroughly investigated the receptors known to directly or indirectly mediate the effects of BPA. The expression patterns of high affinity BPA receptors (ERRγ, GPR30, of ketosteroid receptors (ERs, AR, PGR, GR, MR, of the retinoid receptor RXRα and PPARγ were established using RT-qPCR analysis of RNAs extracted from microdissected enamel organ of adult rats. Their expression was dependent on the stage of ameloblast differentiation, except that of ERβ and PPARγ which remained undetectable. An additional large scale microarray analysis revealed three main groups of receptors according to their level of expression in maturation stage ameloblasts. The expression level of RXRα was the highest, similar to the vitamin D receptor (VDR, whereas the others were 13 to 612 fold lower, with AR and GR being intermediate. Immunofluorescent analysis of VDR, ERα and AR confirmed their presence mainly in maturation- stage ameloblasts. These data provide further evidence that ameloblasts express a specific combination of hormonal receptors depending on their developmental stage. This study represents the first step towards understanding dental endocrinology as well as some of the effects of EDCs on the pathophysiology of amelogenesis.

  2. Expression of Steroid Receptors in Ameloblasts during Amelogenesis in Rat Incisors.

    Science.gov (United States)

    Houari, Sophia; Loiodice, Sophia; Jedeon, Katia; Berdal, Ariane; Babajko, Sylvie

    2016-01-01

    Endocrine disrupting chemicals (EDCs) play a part in the modern burst of diseases and interfere with the steroid hormone axis. Bisphenol A (BPA), one of the most active and widely used EDCs, affects ameloblast functions, leading to an enamel hypomineralization pattern similar to that of Molar Incisor Hypomineralization (MIH). In order to explore the molecular pathways stimulated by BPA during amelogenesis, we thoroughly investigated the receptors known to directly or indirectly mediate the effects of BPA. The expression patterns of high affinity BPA receptors (ERRγ, GPR30), of ketosteroid receptors (ERs, AR, PGR, GR, MR), of the retinoid receptor RXRα, and PPARγ were established using RT-qPCR analysis of RNAs extracted from microdissected enamel organ of adult rats. Their expression was dependent on the stage of ameloblast differentiation, except that of ERβ and PPARγ which remained undetectable. An additional large scale microarray analysis revealed three main groups of receptors according to their level of expression in maturation-stage ameloblasts. The expression level of RXRα was the highest, similar to the vitamin D receptor (VDR), whereas the others were 13 to 612-fold lower, with AR and GR being intermediate. Immunofluorescent analysis of VDR, ERα and AR confirmed their presence mainly in maturation- stage ameloblasts. These data provide further evidence that ameloblasts express a specific combination of hormonal receptors depending on their developmental stage. This study represents the first step toward understanding dental endocrinology as well as some of the effects of EDCs on the pathophysiology of amelogenesis.

  3. Vestigialization of an allosteric switch: genetic and structural mechanisms for the evolution of constitutive activity in a steroid hormone receptor.

    Directory of Open Access Journals (Sweden)

    Jamie T Bridgham

    2014-01-01

    Full Text Available An important goal in molecular evolution is to understand the genetic and physical mechanisms by which protein functions evolve and, in turn, to characterize how a protein's physical architecture influences its evolution. Here we dissect the mechanisms for an evolutionary shift in function in the mollusk ortholog of the steroid hormone receptors (SRs, a family of biologically essential transcription factors. In vertebrates, the activity of SRs allosterically depends on binding a hormonal ligand; in mollusks, however, the SR ortholog (called ER, because of high sequence similarity to vertebrate estrogen receptors activates transcription in the absence of ligand and does not respond to steroid hormones. To understand how this shift in regulation evolved, we combined evolutionary, structural, and functional analyses. We first determined the X-ray crystal structure of the ER of the Pacific oyster Crassostrea gigas (CgER, and found that its ligand pocket is filled with bulky residues that prevent ligand occupancy. To understand the genetic basis for the evolution of mollusk ERs' unique functions, we resurrected an ancient SR progenitor and characterized the effect of historical amino acid replacements on its functions. We found that reintroducing just two ancient replacements from the lineage leading to mollusk ERs recapitulates the evolution of full constitutive activity and the loss of ligand activation. These substitutions stabilize interactions among key helices, causing the allosteric switch to become "stuck" in the active conformation and making activation independent of ligand binding. Subsequent changes filled the ligand pocket without further affecting activity; by degrading the allosteric switch, these substitutions vestigialized elements of the protein's architecture required for ligand regulation and made reversal to the ancestral function more complex. These findings show how the physical architecture of allostery enabled a few large

  4. Vestigialization of an Allosteric Switch: Genetic and Structural Mechanisms for the Evolution of Constitutive Activity in a Steroid Hormone Receptor

    Science.gov (United States)

    Bridgham, Jamie T.; Keay, June; Ortlund, Eric A.; Thornton, Joseph W.

    2014-01-01

    An important goal in molecular evolution is to understand the genetic and physical mechanisms by which protein functions evolve and, in turn, to characterize how a protein's physical architecture influences its evolution. Here we dissect the mechanisms for an evolutionary shift in function in the mollusk ortholog of the steroid hormone receptors (SRs), a family of biologically essential transcription factors. In vertebrates, the activity of SRs allosterically depends on binding a hormonal ligand; in mollusks, however, the SR ortholog (called ER, because of high sequence similarity to vertebrate estrogen receptors) activates transcription in the absence of ligand and does not respond to steroid hormones. To understand how this shift in regulation evolved, we combined evolutionary, structural, and functional analyses. We first determined the X-ray crystal structure of the ER of the Pacific oyster Crassostrea gigas (CgER), and found that its ligand pocket is filled with bulky residues that prevent ligand occupancy. To understand the genetic basis for the evolution of mollusk ERs' unique functions, we resurrected an ancient SR progenitor and characterized the effect of historical amino acid replacements on its functions. We found that reintroducing just two ancient replacements from the lineage leading to mollusk ERs recapitulates the evolution of full constitutive activity and the loss of ligand activation. These substitutions stabilize interactions among key helices, causing the allosteric switch to become “stuck” in the active conformation and making activation independent of ligand binding. Subsequent changes filled the ligand pocket without further affecting activity; by degrading the allosteric switch, these substitutions vestigialized elements of the protein's architecture required for ligand regulation and made reversal to the ancestral function more complex. These findings show how the physical architecture of allostery enabled a few large-effect mutations

  5. Steroid hormones as regulators of the proliferative activity of normal and neoplastic intestinal epithelial cells (review).

    Science.gov (United States)

    Tutton, P J; Barkla, D H

    1988-01-01

    Glucocorticoid and mineralocorticoid receptors are present in normal epithelial cells of both the small and large intestine and there have also been contentious reports of androgen, oestrogen and progesterone receptors in the epithelium of the normal large intestine. The majority of reports suggest that stimulation of the intestinal glucocorticoid receptors results in increased proliferation of epithelial cells in the small bowel, as does stimulation of androgen receptors and possibly mineralocorticoid receptors. The proliferative response of the normal intestine to oestrogens is difficult to evaluate and that to progestigens appears not to have been reported. Epidemiological studies reveal a higher incidence of bowel cancer in premenopausal women than in men of the same age and yet there is a lower incidence of these tumors in women of higher parity. These findings have been atributted to a variety of non-epithelial gender characteristic such as differences in bile metabolism, colonic bacterial and fecal transit times. In experimental animals, androgens have also been shown to influence carcinogenesis and this could well be attributed to changes in food intake etc. However, many studies have now revealed steroid hormone receptors on colorectal tumor cells and thus a direct effect of the steroid hormones on the epithelium during and after malignant transformation must now be considered.

  6. CDNA CLONING OF FATHEAD MINNOW (PIMEPHALES PROMELAS) ESTROGEN AND ANDROGEN RECEPTORS FOR USE IN STEROID RECEPTOR EXTRAPOLATION STUDIES FOR ENDOCRINE DISRUPTING CHEMICALS

    Science.gov (United States)

    cDNA Cloning of Fathead minnow (Pimephales promelas) Estrogen and Androgen Receptors for Use in Steroid Receptor Extrapolation Studies for Endocrine Disrupting Chemicals. Wilson, V.S.1,, Korte, J.2, Hartig P. 1, Ankley, G.T.2, Gray, L.E., Jr 1, , and Welch, J.E.1. 1U.S...

  7. Steroid receptor status in breast cancer: the roles of radioreceptor assay and immunohistochemistry

    International Nuclear Information System (INIS)

    Myint Aye Mu; Ch'ong

    1997-01-01

    A total of 24 cases of female breast cancer were reviewed, typed and graded based on the WHO classification. The steroid receptors (oestrogen and progesterone receptors) status was assessed using radio-receptor assay (RRA) and immunohistochemical (IH) method. The data showed that there were 21 cases of infiltrating ductal carcinoma of the breast and 3 cases of medullary carcinoma. The age of the patients ranged from 36 to 71 years and 4 patients were post-menopausal. The oestrogen receptor (ER) and progesteronc receptor (PR) status were analyzed by radio-receptor assay using 'H-oestradiol and 3 H-ORG respectively, and also by IH using immunoperoxidase detection assay (DAKO LSAB 2 Kit. Peroxidase K 677). Primary antibodies used were also procured from Dako Corp. and these were mouse anti-human ER and rabbit anti-human PR antibodies. On RRA analysis, 22 (95.7%) cases showed ER positivity (i.e. >20 fmol/mg of cytosol protien), and the ER content ranged from 16.64 to 297.8 fmovmg of cytosol protein. All cases showed PR positivity, and PR content ranged from 20.56 to 364 fmoumg of cytosol protein. A significant positive correlation was found between the ER content and PR content of tumour tissues (r = 0.7132, p<0.003). No significant association was found between ER content and menopausal status or histological grade IH showed that 10 of 24 cases (41.67%) showed ER positivity of which 8 were also PR positive. PR status was negative in all ER negative tissues. A decreasing trend in ER positivity was observed with worsening in histological grade (67% positivity in Grade 1, 50% positivity in Grade 11, and 33% positivity in Grade 111). ER and PR positivity occurred more frequently in pre-menopausal women. The results of this study showed that the result derived from IH method were found to have association with grade of tumour and confirmed findings by other workers. These findings revealed that although the quantitative data from radio-receptor assay for estimation of

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

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Reverting doxorubicin resistance in colon cancer by targeting a key signaling protein, steroid receptor coactivator.

    Science.gov (United States)

    Xiong, Sang; Xiao, Gong-Wei

    2018-04-01

    Although there have been notable improvements in treatments against cancer, further research is required. In colon cancer, nearly all patients eventually experience drug resistance and stop responding to the approved drugs, making treatment difficult. Steroid receptor coactivator (SRC) is an oncogenic nuclear receptor coactivator that serves an important role in drug resistance. The present study generated a doxorubicin-resistant colon cancer cell line, in which the upregulation/activation of SRC was responsible for drug resistance, which in turn activated AKT. Overexpression of receptor tyrosine kinase-like epidermal growth factor receptor and insulin-like growth factor 1 receptor also induced SRC expression. It was observed that doxorubicin resistance in colon cancer also induced epithelial to mesenchymal transition, a decrease in expression of epithelial marker E-cadherin and an increase in the expression of mesenchymal markers, including N-cadherin and vimentin. Additionally, the present study indicated that SRC acts as a common signaling node, and inhibiting SRC in combination with doxorubicin treatment in doxorubicin-resistant cells aids in reversing the resistance. Thus, the present study suggests that activation of SRC is responsible for doxorubicin resistance in colon cancer. However, further research is required to understand the complete mechanism of how drug resistance occurs and how it may be tackled to treat patients.

  10. Sustained expression of steroid receptor coactivator SRC-2/TIF-2 is associated with better prognosis in malignant pleural mesothelioma.

    LENUS (Irish Health Repository)

    Jennings, Cormac J

    2012-02-01

    INTRODUCTION: Estrogen receptor beta (ERbeta) overexpression by malignant pleural mesothelioma (MPM) tumor cells correlates with enhanced patient survival. ER-regulated transcription is mediated by the p160 family of steroid receptor coactivators (SRCs), and SRC isoform overexpression is associated with worse prognosis in many steroid-related malignancies. The aim of this study was to establish whether SRC isoform expression varied between individual MPM tumors with positive or negative prognostic significance. METHODS: Immunohistochemical analysis of tumor biopsies from 89 subjects with confirmed histological diagnosis of MPM and biopsies from 3 normal control subjects was performed to detect the expression of SRC-1, SRC-2 (TIF-2), SRC-3 (AIB-1), and ERbeta. Allred scores for expression of ERbeta and each of the SRCs were determined, and Kaplan-Meier survival curves were calculated to correlate biomarker expression, gender, and histology type with postdiagnosis survival. RESULTS: ERbeta and all the SRCs were expressed at high levels in normal pleural mesothelium, and expression of each biomarker was reduced or lost in a subset of the MPM subjects; however, postdiagnosis survival only significantly correlated with TIF-2 expression. Low or intermediate expression of TIF-2 correlated with reduced median postdiagnosis survival (9 months) compared with those subjects whose tumors highly expressed TIF-2 (20 months) (p = 0.036, log-rank test). CONCLUSIONS: Maintained high expression of TIF-2 in tumor cells is a positive prognostic indicator for postdiagnosis survival in patients with confirmed MPM. This is the first clinical study to correlate high TIF-2 expression with improved patient prognosis in any malignancy.

  11. The relationship between ovarian steroids and uterine estrogen receptors during late pregnancy

    International Nuclear Information System (INIS)

    Cathey, T.M.; Chung, Kyung W.

    1991-01-01

    Although a direct interdependence exists between the ovarian steroids, estrogen and progesterone, the exact role of these two hormones during pregnancy, especially late pregnancy, is not completely understood. Investigations have been conducted to determine whether the circulating levels of progesterone and estrogen or changes in the ratio of progesterone/estrogen in relation to the concentration of uterine estrogen receptors are associated with triggering parturition. Ninety-day old female rats were sacrificed at gestation days 14, 16, 18, 20 and two days post-partum. The plasma levels of estradiol and progesterone were measured by solid-phase radioimmunoassay. Uterine cytosol was subjected to a charcoal binding assay to determine the concentration of estrogen receptors. Our findings demonstrate that there is a significant drop in both plasma progesterone and estradiol during late pregnancy. Also indicated is a significant increase in uterine estrogen receptors throughout late pregnancy. Finally, during this period there is a direct correlation between the shift in the progesterone/estrogen ratio and the increase in the concentration of uterine estrogen receptors in late pregnancy

  12. The relationship between ovarian steroids and uterine estrogen receptors during late pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Cathey, T.M.; Chung, Kyung W. (Univ. of Oklahoma, Oklahoma City (USA))

    1991-01-01

    Although a direct interdependence exists between the ovarian steroids, estrogen and progesterone, the exact role of these two hormones during pregnancy, especially late pregnancy, is not completely understood. Investigations have been conducted to determine whether the circulating levels of progesterone and estrogen or changes in the ratio of progesterone/estrogen in relation to the concentration of uterine estrogen receptors are associated with triggering parturition. Ninety-day old female rats were sacrificed at gestation days 14, 16, 18, 20 and two days post-partum. The plasma levels of estradiol and progesterone were measured by solid-phase radioimmunoassay. Uterine cytosol was subjected to a charcoal binding assay to determine the concentration of estrogen receptors. Our findings demonstrate that there is a significant drop in both plasma progesterone and estradiol during late pregnancy. Also indicated is a significant increase in uterine estrogen receptors throughout late pregnancy. Finally, during this period there is a direct correlation between the shift in the progesterone/estrogen ratio and the increase in the concentration of uterine estrogen receptors in late pregnancy.

  13. Regucalcin expression in bovine tissues and its regulation by sex steroid hormones in accessory sex glands.

    Directory of Open Access Journals (Sweden)

    Laura Starvaggi Cucuzza

    Full Text Available Regucalcin (RGN is a mammalian Ca2+-binding protein that plays an important role in intracellular Ca2+ homeostasis. Recently, RGN has been identified as a target gene for sex steroid hormones in the prostate glands and testis of rats and humans, but no studies have focused on RGN expression in bovine tissues. Thus, in the present study, we examined RGN mRNA and protein expression in the different tissues and organs of veal calves and beef cattle. Moreover, we investigated whether RGN expression is controlled through sex steroid hormones in bovine target tissues, namely the bulbo-urethral and prostate glands and the testis. Sex steroid hormones are still illegally used in bovine husbandry to increase muscle mass. The screening of the regulation and function of anabolic sex steroids via modified gene expression levels in various tissues represents a new approach for the detection of illicit drug treatments. Herein, we used quantitative PCR, western blot and immunohistochemistry analyses to demonstrate RGN mRNA and protein expression in bovine tissues. In addition, estrogen administration down-regulated RGN gene expression in the accessory sex glands of veal calves and beef cattle, while androgen treatment reduced RGN gene expression only in the testis. The confirmation of the regulation of RGN gene expression through sex steroid hormones might facilitate the potential detection of hormone abuse in bovine husbandry. Particularly, the specific response in the testis suggests that this tissue is ideal for the detection of illicit androgen administration in veal calves and beef cattle.

  14. Beyond T and DHT - novel steroid derivatives capable of wild type androgen receptor activation.

    Science.gov (United States)

    Mostaghel, Elahe A

    2014-01-01

    While androgen deprivation therapy (ADT) remains the primary treatment for metastatic prostate cancer (PCa), castration does not eliminate androgens from the prostate tumor microenvironment, and residual intratumoral androgens are implicated in nearly every mechanism by which androgen receptor (AR)-mediated signaling promotes castration-resistant disease. The uptake and intratumoral (intracrine) conversion of circulating adrenal androgens such as dehydroepiandrosterone sulfate (DHEA-S) to steroids capable of activating the wild type AR is a recognized driver of castration resistant prostate cancer (CRPC). However, less well-characterized adrenal steroids, including 11-deoxcorticosterone (DOC) and 11beta-hydroxyandrostenedione (11OH-AED) may also play a previously unrecognized role in promoting AR activation. In particular, recent data demonstrate that the 5α-reduced metabolites of DOC and 11OH-AED are activators of the wild type AR. Given the well-recognized presence of SRD5A activity in CRPC tissue, these observations suggest that in the low androgen environment of CRPC, alternative sources of 5α-reduced ligands may supplement AR activation normally mediated by the canonical 5α-reduced agonist, 5α-DHT. Herein we review the emerging data that suggests a role for these alternative steroids of adrenal origin in activating the AR, and discuss the enzymatic pathways and novel downstream metabolites mediating these effects. We conclude by discussing the potential implications of these findings for CRPC progression, particularly in context of new agents such as abiraterone and enzalutamide which target the AR-axis for prostate cancer therapy.

  15. Structural analysis of the evolution of steroid specificity in the mineralocorticoid and glucocorticoid receptors

    Directory of Open Access Journals (Sweden)

    Ollikainen Noah

    2007-02-01

    Full Text Available Abstract Background The glucocorticoid receptor (GR and mineralocorticoid receptor (MR evolved from a common ancestor. Still not completely understood is how specificity for glucocorticoids (e.g. cortisol and mineralocorticoids (e.g. aldosterone evolved in these receptors. Results Our analysis of several vertebrate GRs and MRs in the context of 3D structures of human GR and MR indicates that with the exception of skate GR, a cartilaginous fish, there is a deletion in all GRs, at the position corresponding to Ser-949 in human MR. This deletion occurs in a loop before helix 12, which contains the activation function 2 (AF2 domain, which binds coactivator proteins and influences transcriptional activity of steroids. Unexpectedly, we find that His-950 in human MR, which is conserved in the MR in chimpanzee, orangutan and macaque, is glutamine in all teleost and land vertebrate MRs, including New World monkeys and prosimians. Conclusion Evolution of differences in the responses of the GR and MR to corticosteroids involved deletion in the GR of a residue corresponding to Ser-949 in human MR. A mutation corresponding to His-950 in human MR may have been important in physiological changes associated with emergence of Old World monkeys from prosimians.

  16. Metabotropic Regulation of Extrasynaptic GABAA Receptors

    Directory of Open Access Journals (Sweden)

    William Martin Connelly

    2013-10-01

    Full Text Available A large body of work now shows the importance of GABAA receptor-mediated tonic inhibition in regulating CNS function. However, outside of pathological conditions, there is relatively little evidence that the magnitude of tonic inhibition is itself under regulation. Here we review the mechanisms by which tonic inhibition is known to be modulated, and outline the potential behavioural consequences of this modulation. Specifically, we address the ability of protein kinase A and C to phosphorylate the extrasynaptic receptors responsible for the tonic GABAA current, and how G-protein coupled receptors can regulate tonic inhibition through these effectors. We then speculate about the possible functional consequences of regulating the magnitude of the tonic GABAA current.

  17. Pharmacological profile of CS-3150, a novel, highly potent and selective non-steroidal mineralocorticoid receptor antagonist.

    Science.gov (United States)

    Arai, Kiyoshi; Homma, Tsuyoshi; Morikawa, Yuka; Ubukata, Naoko; Tsuruoka, Hiyoyuki; Aoki, Kazumasa; Ishikawa, Hirokazu; Mizuno, Makoto; Sada, Toshio

    2015-08-15

    The present study was designed to characterize the pharmacological profile of CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist. In the radioligand-binding assay, CS-3150 inhibited (3)H-aldosterone binding to mineralocorticoid receptor with an IC50 value of 9.4nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 36 and 713nM, respectively. CS-3150 also showed at least 1000-fold higher selectivity for mineralocorticoid receptor over other steroid hormone receptors, glucocorticoid receptor, androgen receptor and progesterone receptor. In the reporter gene assay, CS-3150 inhibited aldosterone-induced transcriptional activation of human mineralocorticoid receptor with an IC50 value of 3.7nM, and its potency was superior to that of spironolactone and eplerenone, whose IC50s were 66 and 970nM, respectively. CS-3150 had no agonistic effect on mineralocorticoid receptor and did not show any antagonistic or agonistic effect on glucocorticoid receptor, androgen receptor and progesterone receptor even at the high concentration of 5μM. In adrenalectomized rats, single oral administration of CS-3150 suppressed aldosterone-induced decrease in urinary Na(+)/K(+) ratio, an index of in vivo mineralocorticoid receptor activation, and this suppressive effect was more potent and longer-lasting than that of spironolactone and eplerenone. Chronic treatment with CS-3150 inhibited blood pressure elevation induced by deoxycorticosterone acetate (DOCA)/salt-loading to rats, and this antihypertensive effect was more potent than that of spironolactone and eplerenone. These findings indicate that CS-3150 is a selective and highly potent mineralocorticoid receptor antagonist with long-lasting oral activity. This agent could be useful for the treatment of hypertension, cardiovascular and renal disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Role of sphingosine 1-phosphate receptor expression in eosinophils of patients with allergic rhinitis, and effect of topical nasal steroid treatment on this receptor expression.

    LENUS (Irish Health Repository)

    Mackle, T

    2008-12-01

    Recent research has indicated that sphingosine 1-phosphate plays a role in allergy. This study examined the effect of allergen challenge on the expression of sphingosine 1-phosphate receptors on the eosinophils of allergic rhinitis patients, and the effect of steroid treatment on this expression.

  19. A Drosophila Genome-Wide Screen Identifies Regulators of Steroid Hormone Production and Developmental Timing

    DEFF Research Database (Denmark)

    Thomas Danielsen, E.; E. Møller, Morten; Yamanaka, Naoki

    2016-01-01

    Steroid hormones control important developmental processes and are linked to many diseases. To systematically identify genes and pathways required for steroid production, we performed a Drosophila genome-wide in vivo RNAi screen and identified 1,906 genes with potential roles in steroidogenesis...... and developmental timing. Here, we use our screen as a resource to identify mechanisms regulating intracellular levels of cholesterol, a substrate for steroidogenesis. We identify a conserved fatty acid elongase that underlies a mechanism that adjusts cholesterol trafficking and steroidogenesis with nutrition...... and developmental programs. In addition, we demonstrate the existence of an autophagosomal cholesterol mobilization mechanism and show that activation of this system rescues Niemann-Pick type C1 deficiency that causes a disorder characterized by cholesterol accumulation. These cholesterol-trafficking mechanisms...

  20. Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

    Science.gov (United States)

    Norris, J S; Kohler, P O

    1978-01-01

    Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

  1. Acceleration of the glycolytic flux by steroid receptor coactivator-2 is essential for endometrial decidualization.

    Directory of Open Access Journals (Sweden)

    Ramakrishna Kommagani

    2013-10-01

    Full Text Available Early embryo miscarriage is linked to inadequate endometrial decidualization, a cellular transformation process that enables deep blastocyst invasion into the maternal compartment. Although much of the cellular events that underpin endometrial stromal cell (ESC decidualization are well recognized, the individual gene(s and molecular pathways that drive the initiation and progression of this process remain elusive. Using a genetic mouse model and a primary human ESC culture model, we demonstrate that steroid receptor coactivator-2 (SRC-2 is indispensable for rapid steroid hormone-dependent proliferation of ESCs, a critical cell-division step which precedes ESC terminal differentiation into decidual cells. We reveal that SRC-2 is required for increasing the glycolytic flux in human ESCs, which enables rapid proliferation to occur during the early stages of the decidualization program. Specifically, SRC-2 increases the glycolytic flux through induction of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3, a major rate-limiting glycolytic enzyme. Similarly, acute treatment of mice with a small molecule inhibitor of PFKFB3 significantly suppressed the ability of these animals to exhibit an endometrial decidual response. Together, these data strongly support a conserved mechanism of action by which SRC-2 accelerates the glycolytic flux through PFKFB3 induction to provide the necessary bioenergy and biomass to meet the demands of a high proliferation rate observed in ESCs prior to their differentiation into decidual cells. Because deregulation of endometrial SRC-2 expression has been associated with common gynecological disorders of reproductive-age women, this signaling pathway, involving SRC-2 and PFKFB3, promises to offer new clinical approaches in the diagnosis and/or treatment of a non-receptive uterus in patients presenting idiopathic infertility, recurrent early pregnancy loss, or increased time to pregnancy.

  2. Role of the BAHD1 Chromatin-Repressive Complex in Placental Development and Regulation of Steroid Metabolism.

    Directory of Open Access Journals (Sweden)

    Goran Lakisic

    2016-03-01

    Full Text Available BAHD1 is a vertebrate protein that promotes heterochromatin formation and gene repression in association with several epigenetic regulators. However, its physiological roles remain unknown. Here, we demonstrate that ablation of the Bahd1 gene results in hypocholesterolemia, hypoglycemia and decreased body fat in mice. It also causes placental growth restriction with a drop of trophoblast glycogen cells, a reduction of fetal weight and a high neonatal mortality rate. By intersecting transcriptome data from murine Bahd1 knockout (KO placentas at stages E16.5 and E18.5 of gestation, Bahd1-KO embryonic fibroblasts, and human cells stably expressing BAHD1, we also show that changes in BAHD1 levels alter expression of steroid/lipid metabolism genes. Biochemical analysis of the BAHD1-associated multiprotein complex identifies MIER proteins as novel partners of BAHD1 and suggests that BAHD1-MIER interaction forms a hub for histone deacetylases and methyltransferases, chromatin readers and transcription factors. We further show that overexpression of BAHD1 leads to an increase of MIER1 enrichment on the inactive X chromosome (Xi. In addition, BAHD1 and MIER1/3 repress expression of the steroid hormone receptor genes ESR1 and PGR, both playing important roles in placental development and energy metabolism. Moreover, modulation of BAHD1 expression in HEK293 cells triggers epigenetic changes at the ESR1 locus. Together, these results identify BAHD1 as a core component of a chromatin-repressive complex regulating placental morphogenesis and body fat storage and suggest that its dysfunction may contribute to several human diseases.

  3. Steroidal regulation of Ihh and Gli1 expression in the rat uterus.

    Science.gov (United States)

    Kubota, Kaiyu; Yamauchi, Nobuhiko; Yamagami, Kazuki; Nishimura, Sho; Gobaru, Takafumi; Yamanaka, Ken-ichi; Wood, Chris; Soh, Tomoki; Takahashi, Masashi; Hattori, Masa-aki

    2010-05-01

    Ovarian steroid hormones, progesterone (P4), and estradiol (E2) strictly regulate the endometrial tissue remodeling required for successful embryo implantation. Indian hedgehog (Ihh) is up-regulated by P4 and critically mediates uterine receptivity in the mouse. However, the regulation of Ihh expression during the implantation period still remains unclear. The present study was conducted to elucidate the mechanism of the steroidal regulation in the expression of Ihh and Gli1, the mediator of the Ihh pathway. Ihh mRNA was expressed in the rat uterus on 3.5-5.5 days post-coitus (dpc), while Gli1 expression transiently increased at 3.5 dpc but decreased significantly on 5.5 dpc (P Ihh was induced by the implantation-induced E2 treatment in the primed rat uterus. In contrast, expression of Gli1 was significantly decreased by E2 treatment (P = 0.016). In the case of ICI182.780 (ICI) treatment, Ihh expression was eliminated by ICI, whilst Gli1 expression increased. These results suggest that Ihh expression is maintained at a high level until the initiation of implantation, while the expression of Gli1 is decreased just prior to the initiation of implantation depending on the E2 action. This observation aids in the understanding of the Ihh signaling pathway mediating uterine remodeling for implantation.

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

    Science.gov (United States)

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

    2015-01-01

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

  5. Obesity-induced down-regulation of the mitochondrial translocator protein (TSPO) impairs placental steroid production.

    Science.gov (United States)

    Lassance, Luciana; Haghiac, Maricela; Minium, Judi; Catalano, Patrick; Hauguel-de Mouzon, Sylvie

    2015-01-01

    Low concentrations of estradiol and progesterone are hallmarks of adverse pregnancy outcomes as is maternal obesity. During pregnancy, placental cholesterol is the sole source of sex steroids. Cholesterol trafficking is the limiting step in sex steroid biosynthesis and is mainly mediated by the translocator protein (TSPO), present in the mitochondrial outer membrane. The objective of the study was to investigate the effects of maternal obesity in placental sex steroid biosynthesis and TSPO regulation. One hundred forty-four obese (body mass index 30-35 kg/m(2)) and 90 lean (body mass index 19-25 kg/m(2)) pregnant women (OP and LP, respectively) recruited at scheduled term cesarean delivery. Placenta and maternal blood were collected. This study was conducted at MetroHealth Medical Center (Cleveland, Ohio). Maternal metabolic components (fasting glucose, insulin, leptin, estradiol, progesterone, and total cholesterol) and placental weight were measured. Placenta (mitochondria and membranes separated) and cord blood cholesterol values were verified. The expression and regulation of TSPO and mitochondrial function were analyzed. Plasma estradiol and progesterone concentrations were significantly lower (P < .04) in OP as compared with LP women. Maternal and cord plasma cholesterol were not different between groups. Placental citrate synthase activity and mitochondrial DNA, markers of mitochondrial density, were unchanged, but the mitochondrial cholesterol concentrations were 40% lower in the placenta of OP. TSPO gene and protein expressions were decreased 2-fold in the placenta of OP. In vitro trophoblast activation of the innate immune pathways with lipopolysaccharide and long-chain saturated fatty acids reduced TSPO expression by 2- to 3-fold (P < .05). These data indicate that obesity in pregnancy impairs mitochondrial steroidogenic function through the negative regulation of mitochondrial TSPO.

  6. Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

    Science.gov (United States)

    Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

    2014-09-01

    Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (pyoung muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid administration. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. A multimedia teaching software for self directed training in steroid receptor assay

    International Nuclear Information System (INIS)

    Ch'ong, S.L.; Myint Aye Mu; Ch'ng, H.M.; Pathmanathan, R.

    1997-01-01

    Use of information technology as one of the instructional tools in problem based learning in the discipline of chemical pathology is receiving widespread interest (1). This will hopefully speed up the process of information access, retrieval, rehearsal, cognitive apprenticeship which will ultimately improve the understanding of chemical pathology and the optimal uses of laboratory investigation techniques. This program is written for self-directed training in steroid receptor assay (we believe to be the first of its kind) with a multimedia software Authorware (purchased from Macromedia, Inc. ) to create a rich blend of animation, colours, graphics, sounds and interactive questions (without giving the answer away). It is hoped that this software can assist the trainee in the process of learning by presenting to him/her sequence of 'related' problems with feedback for success or failure-learning from error, but with assistance - in a real-world job problem or case situated learning- cognitive apprenticeship to assist the trainee in appropriate neuro-networking to make the appropriate response

  8. Hypothalamic transcriptional expression of the kisspeptin system and sex steroid receptors differs among polycystic ovary syndrome rat models with different endocrine phenotypes.

    Science.gov (United States)

    Marcondes, Rodrigo Rodrigues; Carvalho, Kátia Cândido; Giannocco, Gisele; Duarte, Daniele Coelho; Garcia, Natália; Soares-Junior, José Maria; da Silva, Ismael Dale Cotrim Guerreiro; Maliqueo, Manuel; Baracat, Edmund Chada; Maciel, Gustavo Arantes Rosa

    2017-08-01

    Polycystic ovary syndrome is a heterogeneous endocrine disorder that affects reproductive-age women. The mechanisms underlying the endocrine heterogeneity and neuroendocrinology of polycystic ovary syndrome are still unclear. In this study, we investigated the expression of the kisspeptin system and gonadotropin-releasing hormone pulse regulators in the hypothalamus as well as factors related to luteinizing hormone secretion in the pituitary of polycystic ovary syndrome rat models induced by testosterone or estradiol. A single injection of testosterone propionate (1.25 mg) (n=10) or estradiol benzoate (0.5 mg) (n=10) was administered to female rats at 2 days of age to induce experimental polycystic ovary syndrome. Controls were injected with a vehicle (n=10). Animals were euthanized at 90-94 days of age, and the hypothalamus and pituitary gland were used for gene expression analysis. Rats exposed to testosterone exhibited increased transcriptional expression of the androgen receptor and estrogen receptor-β and reduced expression of kisspeptin in the hypothalamus. However, rats exposed to estradiol did not show any significant changes in hormone levels relative to controls but exhibited hypothalamic downregulation of kisspeptin, tachykinin 3 and estrogen receptor-α genes and upregulation of the gene that encodes the kisspeptin receptor. Testosterone- and estradiol-exposed rats with different endocrine phenotypes showed differential transcriptional expression of members of the kisspeptin system and sex steroid receptors in the hypothalamus. These differences might account for the different endocrine phenotypes found in testosterone- and estradiol-induced polycystic ovary syndrome rats.

  9. Computer program for Scatchard analysis of protein: Ligand interaction - use for determination of soluble and nuclear steroid receptor concentrations

    International Nuclear Information System (INIS)

    Leake, R.; Cowan, S.; Eason, R.

    1998-01-01

    Steroid receptor concentration may be determined routinely in biopsy samples of breast and endometrial cancer by the competition method. This method yields data for both the soluble and nuclear fractions of the tissue. The data are usually subject to Scatchard analysis. This Appendix describes a computer program written initially for a PDP-11. It has been modified for use with IBM, Apple Macintosh and BBC microcomputers. The nature of the correction for competition is described and examples of the printout are given. The program is flexible and its use for different receptors is explained. The program can be readily adapted to other assays in which Scatchard analysis is appropriate

  10. Oligoadenylate synthetase 1 (OAS1 expression in human breast and prostate cancer cases, and its regulation by sex steroid hormones

    Directory of Open Access Journals (Sweden)

    Cláudio Jorge Maia

    2016-06-01

    Full Text Available Oligoadenylate synthetase 1 (OAS1 is an interferon-induced protein characterised by its capacity to catalyse the synthesis of 2ʹ-5ʹ-linked oligomers of adenosine from adenosine triphosphate (2-5A. The 2-5A binds to a latent Ribonuclease L (RNase L, which subsequently dimerises into its active form and may play an important role in the control of cell growth, differentiation and apoptosis. Previously, our research group identified OAS1 as a differentially-expressed gene in breast and prostate cancer cell lines when compared to normal cells. This study evaluates: i the expression of OAS1 in human breast and prostate cancer specimens; and ii the effect of sex steroid hormones in regulating the expression of OAS1 in breast (MCF-7 and prostate (LNCaP cancer cell lines. The obtained results showed that OAS1 expression was down-regulated in human infiltrative ductal carcinoma of breast, adenocarcinoma of prostate, and benign prostate hyperplasia, both at mRNA and protein level. In addition, OAS1 expression was negatively correlated with the progression of breast and prostate cancer. With regards to the regulation of OAS1 gene, it was demonstrated that 17β-estradiol (E2 down-regulates OAS1 gene in MCF-7 cell lines, an effect that seems to be dependent on the activation of oestrogen receptor (ER. On the other hand, 5α-dihydrotestosterone (DHT treatment showed no effect on the expression of OAS1 in LNCaP cell lines. The lower levels of OAS1 in breast and prostate cancer cases indicated that the OAS1/RNaseL apoptotic pathway may be compromised in breast and prostate tumours. Moreover, the present findings suggested that this effect may be enhanced by oestrogen in ER-positive breast cancers.

  11. Steroid receptor coactivators 1 and 2 mediate fetal-to-maternal signaling that initiates parturition.

    Science.gov (United States)

    Gao, Lu; Rabbitt, Elizabeth H; Condon, Jennifer C; Renthal, Nora E; Johnston, John M; Mitsche, Matthew A; Chambon, Pierre; Xu, Jianming; O'Malley, Bert W; Mendelson, Carole R

    2015-07-01

    The precise mechanisms that lead to parturition are incompletely defined. Surfactant protein-A (SP-A), which is secreted by fetal lungs into amniotic fluid (AF) near term, likely provides a signal for parturition; however, SP-A-deficient mice have only a relatively modest delay (~12 hours) in parturition, suggesting additional factors. Here, we evaluated the contribution of steroid receptor coactivators 1 and 2 (SRC-1 and SRC-2), which upregulate SP-A transcription, to the parturition process. As mice lacking both SRC-1 and SRC-2 die at birth due to respiratory distress, we crossed double-heterozygous males and females. Parturition was severely delayed (~38 hours) in heterozygous dams harboring SRC-1/-2-deficient embryos. These mothers exhibited decreased myometrial NF-κB activation, PGF2α, and expression of contraction-associated genes; impaired luteolysis; and elevated circulating progesterone. These manifestations also occurred in WT females bearing SRC-1/-2 double-deficient embryos, indicating that a fetal-specific defect delayed labor. SP-A, as well as the enzyme lysophosphatidylcholine acyltransferase-1 (LPCAT1), required for synthesis of surfactant dipalmitoylphosphatidylcholine, and the proinflammatory glycerophospholipid platelet-activating factor (PAF) were markedly reduced in SRC-1/-2-deficient fetal lungs near term. Injection of PAF or SP-A into AF at 17.5 days post coitum enhanced uterine NF-κB activation and contractile gene expression, promoted luteolysis, and rescued delayed parturition in SRC-1/-2-deficient embryo-bearing dams. These findings reveal that fetal lungs produce signals to initiate labor when mature and that SRC-1/-2-dependent production of SP-A and PAF is crucial for this process.

  12. Gonadotrophin-inhibitory hormone receptor expression in the chicken pituitary gland: potential influence of sexual maturation and ovarian steroids.

    Science.gov (United States)

    Maddineni, S; Ocón-Grove, O M; Krzysik-Walker, S M; Hendricks, G L; Proudman, J A; Ramachandran, R

    2008-09-01

    Gonadotrophin-inhibitory hormone (GnIH), a hypothalamic RFamide, has been found to inhibit gonadotrophin secretion from the anterior pituitary gland originally in birds and, subsequently, in mammalian species. The gene encoding a transmembrane receptor for GnIH (GnIHR) was recently identified in the brain, pituitary gland and gonads of song bird, chicken and Japanese quail. The objectives of the present study are to characterise the expression of GnIHR mRNA and protein in the chicken pituitary gland, and to determine whether sexual maturation and gonadal steroids influence pituitary GnIHR mRNA abundance. GnIHR mRNA quantity was found to be significantly higher in diencephalon compared to either anterior pituitary gland or ovaries. GnIHR mRNA quantity was significantly higher in the pituitaries of sexually immature chickens relative to sexually mature chickens. Oestradiol or a combination of oestradiol and progesterone treatment caused a significant decrease in pituitary GnIHR mRNA quantity relative to vehicle controls. GnIHR-immunoreactive (ir) cells were identified in the chicken pituitary gland cephalic and caudal lobes. Furthermore, GnIHR-ir cells were found to be colocalised with luteinising hormone (LH)beta mRNA-, or follicle-stimulating hormone (FSH)beta mRNA-containing cells. GnIH treatment significantly decreased LH release from anterior pituitary gland slices collected from sexually immature, but not from sexually mature chickens. Taken together, GnIHR gene expression is possibly down regulated in response to a surge in circulating oestradiol and progesterone levels as the chicken undergoes sexual maturation to allow gonadotrophin secretion. Furthermore, GnIHR protein expressed in FSHbeta or LHbeta mRNA-containing cells is likely to mediate the inhibitory effect of GnIH on LH and FSH secretion.

  13. In vitro and in vivo binding of neuroactive steroids to the sigma-1 receptor as measured with the positron emission tomography radioligand [18F]FPS.

    Science.gov (United States)

    Waterhouse, Rikki N; Chang, Raymond C; Atuehene, Nana; Collier, Thomas Lee

    2007-07-01

    Sigma-1 receptors are widely expressed in the mammalian brain and also in organs of the immune, endocrine and reproductive systems. Based on behavioral and pharmacological assessments, sigma-1 receptors are important in memory and cognitive processes, and are thought to be involved in specific psychiatric illnesses, including schizophrenia, depression, and drug addiction. It is thought that specific neuroactive steroids are endogenous ligands for these sites. In addition, several sigma-1 receptor binding steroids including progesterone, dihydroepiandrosterone (DHEA), and testosterone are being examined clinically for specific therapeutic purposes; however, their mechanisms of action have not been clearly defined. We previously described the high affinity sigma-1 receptor selective PET tracer [(18)F]FPS. This study examines the effect of neuroactive steroids on [(18)F]FPS binding in vitro and in vivo. Inhibition constants were determined in vitro for progesterone, testosterone, DHEA, estradiol, and estriol binding to the [(18)F]FPS labeled receptor. The affinity order (K(i) values) for these steroids ranged from 36 nM for progesterone to >10,000 nM for estrodiol and estriol. Biodistribution studies revealed that i.v. coadministration of progesterone (10 mg/kg), testosterone (20 mg/kg), or DHEA (20 mg/kg) significantly decreased [(18)F]FPS uptake (%ID/g) by up to 50% in nearly all of eight brain regions examined. [(18)F]FPS uptake in several peripheral organs that express sigma-1 receptors (heart, spleen, muscle, lung) was also reduced (54-85%). These studies clearly demonstrate that exogenously administered steroids can occupy sigma-1 receptors in vivo, and that [(18)F]FPS may provide an effective tool for monitoring sigma-1 receptor occupancy of specific therapeutic steroids during clinical trials.

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

    Science.gov (United States)

    Fukui, Hajime; Toyoshima, Kumiko

    2013-01-01

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

  15. The anabolic steroid nandrolone alters cannabinoid self-administration and brain CB1 receptor density and function.

    Science.gov (United States)

    Struik, Dicky; Fadda, Paola; Zara, Tamara; Zamberletti, Erica; Rubino, Tiziana; Parolaro, Daniela; Fratta, Walter; Fattore, Liana

    2017-01-01

    Clinical and pre-clinical observations indicate that anabolic-androgenic steroids can induce neurobiological changes that alter the rewarding effects of drugs of abuse. In this study, we investigated the effect of the anabolic steroid nandrolone on the rewarding properties of the cannabinoid CB 1 receptor agonist WIN55,212-2 (WIN) in rats. Lister Hooded male rats were treated intramuscularly with nandrolone (15mg/kg) or vehicle for 14 consecutive days, and then allowed to self-administer WIN (12.5μg/kg/infusion) intravenously. After reaching stable drug intake, self-administration behavior was extinguished to examine drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Other behavioral parameters presumed to influence drug-taking and drug-seeking behaviors were examined to gain more insight into the behavioral specificity of nandrolone treatment. Finally, animals were sacrificed for analysis of CB 1 receptor density and function in selected brain areas. We found that nandrolone-treated rats self-administered up to 2 times more cannabinoid than vehicle-treated rats, but behaved similarly to control rats when tested for drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Enhanced cannabinoid intake by nandrolone-treated rats was not accompanied by changes in locomotor activity, sensorimotor gating, or memory function. However, our molecular data show that after chronic WIN self-administration nandrolone-treated rats display altered CB 1 receptor density and function in selected brain areas. We hypothesize that increased cannabinoid self-administration in nandrolone-treated rats results from a nandrolone-induced decrease in reward function, which rats seem to compensate by voluntarily increasing their cannabinoid intake. Altogether, our findings corroborate the hypothesis that chronic exposure to anabolic-androgenic steroids induces dysfunction of the reward pathway in rats and might represent a potential risk factor for abuse of

  16. In polycystic ovary syndrome, adrenal steroids are regulated differently in the morning versus in response to nutrient intake

    Science.gov (United States)

    The objective of this study was to investigate adrenal steroid regulation in Polycystic Ovary Syndrome (PCOS). A 5-h oral glucose tolerance test (OGTT) and a 3-h frequently sampled-intravenous glucose tolerance test (FSIVGTT) were administered to 30 patients with PCOS. Anthropometric parameters (hei...

  17. Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

    Directory of Open Access Journals (Sweden)

    Azevedo R.B.

    2001-01-01

    Full Text Available Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%. Removal of the gonads in both males and females (comparison between castrated groups increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48% CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

  18. Vitamin D receptor gene TaqI and Apal polymorphisms and steroid responsiveness in childhood idiopathic nephrotic syndrome

    Directory of Open Access Journals (Sweden)

    Al-Eisa AA

    2016-08-01

    Full Text Available Amal A Al-Eisa, Mohammad Z Haider Department of Pediatrics, Faculty of Medicine, Kuwait University, Safat, Kuwait Background: Vitamin D activity is controlled by vitamin D receptors (VDRs, which are affected by different genetic polymorphisms, including TaqI and Apal restriction fragment length polymorphisms (RFLPs, which have been reported to be associated with several diseases. The aim of this study was to determine the frequency and the association of VDR gene polymorphisms with idiopathic nephrotic syndrome (INS and steroid responsiveness in Kuwaiti children. Subjects and methods: Genotypes of the VDR TaqI gene polymorphism and the Apal gene polymorphism were analyzed using polymerase chain reaction-RFLP in 78 INS patients and 56 matched controls. Results: A total of 78 INS (62 steroid sensitive [SS] and 16 steroid resistant [SR] patients with a mean age of 6.5±3.1 years were studied. Male:female ratio was 2:1. The TT genotype of VDR–TaqI polymorphism was detected in 41% of the INS patients compared to 42% of the controls (P=0.816. The heterozygous TC genotype was detected in 33% of INS patients compared to 46% of the controls (P=0.462. The CC genotype was detected in 25.6% of INS patients and 21% of the controls (P=0.719. The C-allele frequency, in its homozygous and heterozygous forms, was 71% in INS patients compared to 63% in the controls (P=0.342. Similarly, no significant difference was detected in terms of VDR–Apal polymorphism in INS patients compared to the controls for all the three genotypes (P=0.76, P=0.207, and P=0.364, respectively, for GG, GT, and TT genotypes. The T-allele frequency, in its homozygous and heterozygous forms, was 89% in INS patients compared to 93% in the controls (P=0.076. No significant difference was found in any of the allele frequencies between SS and SR subgroups when compared with each other or when compared to the controls. Conclusion: Our data do not support the use of VDR–TaqI or

  19. Distinctly different dynamics and kinetics of two steroid receptors at the same response elements in living cells.

    Directory of Open Access Journals (Sweden)

    Hatice Z Nenseth

    Full Text Available Closely related transcription factors (TFs can bind to the same response elements (REs with similar affinities and activate transcription. However, it is unknown whether transcription is similarly orchestrated by different TFs bound at the same RE. Here we have compared the recovery half time (t1/2, binding site occupancy and the resulting temporal changes in transcription upon binding of two closely related steroid receptors, the androgen and glucocorticoid receptors (AR and GR, to their common hormone REs (HREs. We show that there are significant differences at all of these levels between AR and GR at the MMTV HRE when activated by their ligands. These data show that two TFs bound at the same RE can have significantly different modes of action that can affect their responses to environmental cues.

  20. Steroids Regulate CXCL4 in the Human Endometrium During Menstruation to Enable Efficient Endometrial Repair.

    Science.gov (United States)

    Maybin, Jacqueline A; Thiruchelvam, Uma; Madhra, Mayank; Saunders, Philippa T K; Critchley, Hilary O D

    2017-06-01

    Repair of the endometrial surface at menstruation must be efficient to minimize blood loss and optimize reproductive function. The mechanism and regulation of endometrial repair remain undefined. To determine the presence/regulation of CXCL4 in the human endometrium as a putative repair factor at menses. Endometrial tissue was collected throughout the menstrual cycle from healthy women attending the gynecology department. Menstrual blood loss was objectively measured in a subset, and heavy menstrual bleeding (HMB) was defined as >80 mL per cycle. Monocytes were isolated from peripheral blood. CXCL4 messenger RNA (mRNA) and protein were identified by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The function/regulation of endometrial CXCL4 was explored by in vitro cell culture. CXCL4 mRNA concentrations were significantly increased during menstruation. Intense staining for CXCL4 was detected in late secretory and menstrual tissue, localized to stromal, epithelial and endothelial cells. Colocalization identified positive staining in CD68+ macrophages. Treatment of human endometrial stromal and endothelial cells (hESCs and HEECs, respectively) with steroids revealed differential regulation of CXCL4. Progesterone withdrawal resulted in significant increases in CXCL4 mRNA and protein in hESCs, whereas cortisol significantly increased CXCL4 in HEECs. In women with HMB, CXCL4 was reduced in endothelial cells during the menstrual phase compared with women with normal menstrual bleeding. Cortisol-exposed macrophages displayed increased chemotaxis toward CXCL4 compared with macrophages incubated with estrogen or progesterone. These data implicate CXCL4 in endometrial repair after menses. Reduced cortisol at the time of menses may contribute to delayed endometrial repair and HMB, in part by mechanisms involving aberrant expression of CXCL4. Copyright © 2017 by the Endocrine Society

  1. Direct binding and activation of protein kinase C isoforms by steroid hormones.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2008-10-01

    The non-genomic action of steroid hormones regulates a wide variety of cellular responses including regulation of ion transport, cell proliferation, migration, death and differentiation. In order to achieve such plethora of effects steroid hormones utilize nearly all known signal transduction pathways. One of the key signalling molecules regulating the non-genomic action of steroid hormones is protein kinase C (PKC). It is thought that rapid action of steroids hormones results from the activation of plasma membrane receptors; however, their molecular identity remains elusive. In recent years, an increasing number of studies have pointed at the selective binding and activation of specific PKC isoforms by steroid hormones. This has led to the hypothesis that PKC could act as a receptor as well as a transducer of the non-genomic effects of these hormones. In this review we summarize the current knowledge of the direct binding and activation of PKC by steroid hormones.

  2. Identifying a Mechanism for Crosstalk Between the Estrogen and Glucocorticoid Receptors | Center for Cancer Research

    Science.gov (United States)

    Estrogen has long been known to play important roles in the development and progression of breast cancer. Its receptor (ER), a member of the steroid receptor family, binds to estrogen response elements (EREs) in DNA and regulates gene transcription. More recently, another steroid receptor family member, the glucocorticoid receptor (GR), has been implicated in breast cancer

  3. Regulation of connexin26 and connexin43 expression in rat endometrium by ovarian steroid hormones.

    Science.gov (United States)

    Grümmer, R; Chwalisz, K; Mulholland, J; Traub, O; Winterhager, E

    1994-12-01

    A distinct spatial and temporal pattern of connexin26 and connexin43 (cx26 and cx43) expression was observed in the rat endometrium in response to embryo implantation; however, connexin expression was suppressed during the preimplantation period. Pseudopregnant rats did not show connexin mRNA, while artificial decidualization induced by a scratch led to a strong expression of cx26 and cx43 in the endometrium of these animals. In order to examine the regulatory effects of ovarian steroid hormones on connexin expression, ovariectomized rats were treated with progesterone (P) and/or estradiol-17 beta (E2). Untreated, ovariectomized animals expressed mRNA for cx43, but not for cx26. Endometrial expression of mRNA for both connexins was strongly enhanced by E2 treatment; immunolabeling revealed protein for cx26 in the uterine luminal epithelial cells and for cx43 in the uterine stromal cells. P treatment, either alone or in combination with E2, suppressed expression of connexin mRNA. P suppression in the presence of E2 was reversible when P was withdrawn. When administered on Days 0-2 of pregnancy, the antiprogestin onapristone inhibited the effect of P and gave rise to strong expression of both connexin transcripts. These results demonstrate that expression of cx26 and cx43 in the rat uterine endometrium is differentially regulated by E2 and P during early pregnancy.

  4. Identification and transcriptional modulation of the largemouth bass, Micropterus salmoides, vitellogenin receptor during oocyte development by insulin and sex steroids.

    Science.gov (United States)

    Dominguez, Gustavo A; Quattro, Joseph M; Denslow, Nancy D; Kroll, Kevin J; Prucha, Melinda S; Porak, Wesley F; Grier, Harry J; Sabo-Attwood, Tara L

    2012-09-01

    Fish vitellogenin synthesized and released from the liver of oviparous animals is taken up into oocytes by the vitellogenin receptor. This is an essential process in providing nutrient yolk to developing embryos to ensure successful reproduction. Here we disclose the full length vtgr cDNA sequence for largemouth bass (LMB) that reveals greater than 90% sequence homology with other fish vtgr sequences. We classify LMB Vtgr as a member of the low density lipoprotein receptor superfamily based on conserved domains and categorize as the short variant that is devoid of the O-glycan segment. Phylogenetic analysis places LMB Vtgr sequence into a well-supported monophyletic group of fish Vtgr. Real-time PCR showed that the greatest levels of LMB vtgr mRNA expression occurred in previtellogenic ovarian tissues. In addition, we reveal the effects of insulin, 17beta-estradiol (E(2)), and 11-ketotestosterone (11-KT) in modulation of vtgr, esr, and ar mRNAs in previtellogenic oocytes. Insulin increased vtgr expression levels in follicles ex vivo while exposure to E(2) or 11-KT did not result in modulation of expression. However, both steroids were able to repress insulin-induced vtgr transcript levels. Coexposure with insulin and E(2) or of insulin and 11-KT increased ovarian esr2b and ar mRNA levels, respectively, which suggest a role for these nuclear receptors in insulin-mediated signaling pathways. These data provide the first evidence for the ordered stage-specific expression of LMB vtgr during the normal reproductive process and the hormonal influence of insulin and sex steroids on controlling vtgr transcript levels in ovarian tissues.

  5. Beyond the HPA-axis: The role of the gonadal steroid hormone receptors in modulating stress-related responses in an animal model of PTSD.

    Science.gov (United States)

    Fenchel, Daphna; Levkovitz, Yechiel; Vainer, Ella; Kaplan, Zeev; Zohar, Joseph; Cohen, Hagit

    2015-06-01

    The hypothalamic-pituitary-adrenal (HPA) axis, which plays a major role in the response to stress, and the hypothalamic-pituitary-gonadal (HPG) axis are closely linked with the ability to inhibit the other. Testosterone, a product of the HPG, has many beneficial effects beyond its functions as a sex hormone including anti-anxiety properties. In this study we examined the effect of stress exposure on gonadal hormones, and their efficacy in modulating anxiety-like response in an animal model of PTSD. Male rats were exposed to predator scent stress, followed by analysis of brain expression of androgen receptor (AR) receptor and estrogen receptor α (ERα). The behavioral effects of immediate treatment with testosterone, testosterone receptor antagonist (flutamide) or vehicle were evaluated using the elevated plus-maze, acoustic startle response and trauma-cue response. Levels of circulating corticosterone and testosterone were also measured after treatment. The behavioral effects of delayed testosterone treatment were explored in the same manner. We report that animals whose behavior was extremely disrupted (EBR) selectively displayed significant down-regulation of AR and ERα in the hippocampus. Immediate treatment with flutamide or delayed treatment with testosterone significantly increased prevalence rates of minimal behavioral response (MBR) and decreased prevalence of EBR with favorable behavioral results. Testosterone levels were higher in control un-exposed animals, while corticosterone was higher in control exposed animals. This study suggests that gonadal steroid hormones are involved in the neurobiological response to predator scent stress and thus warrant further study as a potential therapeutic avenue for the treatment of anxiety-related disorders. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

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

    OpenAIRE

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

    2010-01-01

    The establishment of sex-specific neural morphology, which underlies sex-specific behaviors, occurs during a perinatal sensitive window in which brief exposure to gonadal steroid hormones produces permanent masculinization of the brain. In the rodent, estradiol derived from testicular androgens is a principle organizational hormone. The mechanism by which transient estradiol exposure induces permanent differences in neuronal anatomy has been widely investigated, but remains elusive. Epigeneti...

  7. Disruption of histone modification and CARM1 recruitment by arsenic represses transcription at glucocorticoid receptor-regulated promoters.

    Science.gov (United States)

    Barr, Fiona D; Krohmer, Lori J; Hamilton, Joshua W; Sheldon, Lynn A

    2009-08-26

    Chronic exposure to inorganic arsenic (iAs) found in the environment is one of the most significant and widespread environmental health risks in the U.S. and throughout the world. It is associated with a broad range of health effects from cancer to diabetes as well as reproductive and developmental anomalies. This diversity of diseases can also result from disruption of metabolic and other cellular processes regulated by steroid hormone receptors via aberrant transcriptional regulation. Significantly, exposure to iAs inhibits steroid hormone-mediated gene activation. iAs exposure is associated with disease, but is also used therapeutically to treat specific cancers complicating an understanding of iAs action. Transcriptional activation by steroid hormone receptors is accompanied by changes in histone and non-histone protein post-translational modification (PTM) that result from the enzymatic activity of coactivator and corepressor proteins such as GRIP1 and CARM1. This study addresses how iAs represses steroid receptor-regulated gene transcription. PTMs on histones H3 and H4 at the glucocorticoid receptor (GR)-activated mouse mammary tumor virus (MMTV) promoter were identified by chromatin immunoprecipitation analysis following exposure to steroid hormone+/-iAs. Histone H3K18 and H3R17 amino acid residues had significantly different patterns of PTMs after treatment with iAs. Promoter interaction of the coactivator CARM1 was disrupted, but the interaction of GRIP1, a p160 coactivator through which CARM1 interacts with a promoter, was intact. Over-expression of CARM1 was able to fully restore and GRIP1 partially restored iAs-repressed transcription indicating that these coactivators are functionally associated with iAs-mediated transcriptional repression. Both are essential for robust transcription at steroid hormone regulated genes and both are associated with disease when inappropriately expressed. We postulate that iAs effects on CARM1 and GRIP1 may underlie some

  8. Enhanced Androgen Signaling with Androgen Receptor Overexpression in the Osteoblast Lineage Controls Skeletal Turnover, Matrix Quality and Bone Architecture

    Science.gov (United States)

    2009-12-01

    Fu , M. , and Pestell , R. ( 2006 ). Epigenetic regulation of nuclear steroid receptors . Biochem. Pharmacol. 72 , 1589 – 1596...2006;38:1289–1297. 21. Leader J, Wang C, Fu M, Pestell R. Epigenetic regulation of nuclear steroid receptors. Biochem Pharmacol 2006;72:1589–1596. 22...Nat Genet 2006;38:1289-97. 21. Leader J, Wang C, Fu M, Pestell R. Epigenetic regulation of nuclear steroid receptors. Biochem Pharmacol 2006;72

  9. Regulation of the sperm calcium channel CatSper by endogenous steroids and plant triterpenoids.

    Science.gov (United States)

    Mannowetz, Nadja; Miller, Melissa R; Lishko, Polina V

    2017-05-30

    The calcium channel of sperm (CatSper) is essential for sperm hyperactivated motility and fertility. The steroid hormone progesterone activates CatSper of human sperm via binding to the serine hydrolase ABHD2. However, steroid specificity of ABHD2 has not been evaluated. Here, we explored whether steroid hormones to which human spermatozoa are exposed in the male and female genital tract influence CatSper activation via modulation of ABHD2. The results show that testosterone, estrogen, and hydrocortisone did not alter basal CatSper currents, whereas the neurosteroid pregnenolone sulfate exerted similar effects as progesterone, likely binding to the same site. However, physiological concentrations of testosterone and hydrocortisone inhibited CatSper activation by progesterone. Additionally, testosterone antagonized the effect of pregnenolone sulfate. We have also explored whether steroid-like molecules, such as the plant triterpenoids pristimerin and lupeol, affect sperm fertility. Interestingly, both compounds competed with progesterone and pregnenolone sulfate and significantly reduced CatSper activation by either steroid. Furthermore, pristimerin and lupeol considerably diminished hyperactivation of capacitated spermatozoa. These results indicate that ( i ) pregnenolone sulfate together with progesterone are the main steroids that activate CatSper and ( ii ) pristimerin and lupeol can act as contraceptive compounds by averting sperm hyperactivation, thus preventing fertilization.

  10. ent-Steroids: Novel Tools for Studies of Signaling Pathways

    OpenAIRE

    Covey, Douglas F.

    2008-01-01

    Membrane receptors are often modulated by steroids and it is necessary to distinguish the effects of steroids at these receptors from effects occurring at nuclear receptors. Additionally, it may also be mechanistically important to distinguish between direct effects caused by binding of steroids to membrane receptors and indirect effects on membrane receptor function caused by steroid perturbation of the membrane containing the receptor. In this regard, ent-steroids, the mirror images of natu...

  11. Inhaled Steroids

    Science.gov (United States)

    ... considerations when your dosage changes. What about side effects and inhaled steroids? The most common side effects with inhaled steroids ... inhaled steroid has much less potential for side effects than steroid pills or syrups. There have been concerns regarding ...

  12. Androgen regulation of the androgen receptor coregulators

    International Nuclear Information System (INIS)

    Urbanucci, Alfonso; Waltering, Kati K; Suikki, Hanna E; Helenius, Merja A; Visakorpi, Tapio

    2008-01-01

    The critical role of the androgen receptor (AR) in the development of prostate cancer is well recognized. The transcriptional activity of AR is partly regulated by coregulatory proteins. It has been suggested that these coregulators could also be important in the progression of prostate cancer. The aim of this study was to identify coregulators whose expression is regulated by either the androgens and/or by the expression level of AR. We used empty vector and AR cDNA-transfected LNCaP cells (LNCaP-pcDNA3.1, and LNCaP-ARhi, respectively), and grew them for 4 and 24 hours in the presence of dihydrotestosterone (DHT) at various concentrations. The expression of 25 AR coregulators (SRC1, TIF2, PIAS1, PIASx, ARIP4, BRCA1, β-catenin, AIB3, AIB1, CBP, STAT1, NCoR1, AES, cyclin D1, p300, ARA24, LSD1, BAG1L, gelsolin, prohibitin, JMJD2C, JMJD1A, MAK, PAK6 and MAGE11) was then measured by using real-time quantitative RT-PCR (Q-RT-PCR). Five of the coregulators (AIB1, CBP, MAK, BRCA1 and β-catenin) showed more than 2-fold induction and 5 others (cyclin D1, gelsolin, prohibitin, JMJD1A, and JMJD2C) less than 2-fold induction. Overexpression of AR did not affect the expression of the coregulators alone. However, overexpression of AR enhanced the DHT-stimulated expression of MAK, BRCA1, AIB1 and CBP and reduced the level of expression of β-catenin, cyclinD1 and gelsolin. In conclusion, we identified 5 coactivators whose expression was induced by androgens suggesting that they could potentiate AR signaling. Overexpression of AR seems to sensitize cells for low levels of androgens

  13. The Endocannabinoid System and Sex Steroid Hormone-Dependent Cancers

    Directory of Open Access Journals (Sweden)

    Thangesweran Ayakannu

    2013-01-01

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

  14. Sex steroid receptors and apoptosis-related proteins are differentially expressed in polycystic ovaries of adult dogs.

    Science.gov (United States)

    Chuffa, Luiz Gustavo de Almeida; Lupi Júnior, Luiz Antonio; da Maia Lima, Alfredo Feio

    2016-02-01

    In Polycystic Ovaries (PCOs), the dynamics of sex hormone receptors and follicle-related apoptotic signaling remain unknown. In this study, we investigated the expression of androgen receptors (AR), estrogen receptors (ERα and ERβ), and apoptosis-related molecules (BAX, active caspase-3, Bcl-2 and Survivin) on different follicular stages of PCOs in adult dogs. Clinical evidences of high estradiol and testosterone levels, persistent estrus and vaginal discharge were observed. Inhibin B immunolabeling was increased in primary and 2 to 5-mm follicles, and a marked epithelial hyperplasia was common in the ovarian surface. Ovarian epithelia and primary follicles showed low expression of AR, ERα, and ERβ, whereas a moderate immunoexpression of AR was found in theca cells of secondary follicles and cysts. In PCOs, growing follicles displayed ERα expression, and secondary follicles exhibited higher ERβ expression. In addition, while few ERα-positive cells were found in the cysts, ERβ was moderately expressed in growing follicles and cysts. BAX was upregulated in the ovarian epithelium, primary follicles, and in the wall of follicular cysts. Active caspase-3 was significantly downregulated in the epithelium, primary follicles, and follicular cysts, whereas growing follicles had a strong immunoexpression in the granulosa cells. Bcl-2 and survivin were increased in the epithelium and primary follicles, and only survivin was upregulated in secondary and growing follicles. While Bcl-2 had a diffuse immunexpression in the follicular cysts, survivin was overexpressed by these cells. We concluded that sex steroid receptors and apoptotic proteins are differentially expressed in the follicles of adult dogs with PCOs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Zebrafish (Danio rerio) androgen receptor: sequence homology and up-regulation by the fungicide vinclozolin.

    Science.gov (United States)

    Smolinsky, Amanda N; Doughman, Jennifer M; Kratzke, Liên-Thành C; Lassiter, Christopher S

    2010-03-01

    Steroid hormones regulate gene expression in organisms by binding to receptor proteins. These hormones include the androgens, which signal through androgen receptors (ARs). Endocrine disrupters (EDCs) are chemicals in the environment that adversely affect organisms by binding to nuclear receptors, including ARs. Vinclozolin, a fungicide used on fruit and vegetable crops, is a known anti-androgen, a type of EDC that blocks signals from testosterone and its derivatives. In order to better understand the effects of EDCs, further research on androgen receptors and other hormone signaling pathways is necessary. In this study, we demonstrate the evolutionary conservation between the genomic structure of the human and zebrafish ar genes and find that ar mRNA expression increases in zebrafish embryos exposed to vinclozolin, which may be evolutionarily conserved as well. At 48 and 72 h post-fertilization, vinclozolin-treated embryos express ar mRNA 8-fold higher than the control level. These findings suggest that zebrafish embryos attempt to compensate for the presence of an anti-androgen by increasing the number of androgen receptors available.

  16. Regulation of extracellular matrix vesicles via rapid responses to steroid hormones during endochondral bone formation.

    Science.gov (United States)

    Asmussen, Niels; Lin, Zhao; McClure, Michael J; Schwartz, Zvi; Boyan, Barbara D

    2017-12-09

    Endochondral bone formation is a precise and highly ordered process whose exact regulatory framework is still being elucidated. Multiple regulatory pathways are known to be involved. In some cases, regulation impacts gene expression, resulting in changes in chondrocyte phenotypic expression and extracellular matrix synthesis. Rapid regulatory mechanisms are also involved, resulting in release of enzymes, factors and micro RNAs stored in extracellular matrisomes called matrix vesicles. Vitamin D metabolites modulate endochondral development via both genomic and rapid membrane-associated signaling pathways. 1α,25-dihydroxyvitamin D3 [1α,25(OH) 2 D 3 ] acts through the vitamin D receptor (VDR) and a membrane associated receptor, protein disulfide isomerase A3 (PDIA3). 24R,25-dihydroxyvitamin D3 [24R,25(OH) 2 D 3 ] affects primarily chondrocytes in the resting zone (RC) of the growth plate, whereas 1α,25(OH) 2 D 3 affects cells in the prehypertrophic and upper hypertrophic cell zones (GC). This includes genomically directing the cells to produce matrix vesicles with zone specific characteristics. In addition, vitamin D metabolites produced by the cells interact directly with the matrix vesicle membrane via rapid signal transduction pathways, modulating their activity in the matrix. The matrix vesicle payload is able to rapidly impact the extracellular matrix via matrix processing enzymes as well as providing a feedback mechanism to the cells themselves via the contained micro RNAs. Copyright © 2017. Published by Elsevier Inc.

  17. Modeling Canadian Quality Control Test Program for Steroid Hormone Receptors in Breast Cancer: Diagnostic Accuracy Study.

    Science.gov (United States)

    Pérez, Teresa; Makrestsov, Nikita; Garatt, John; Torlakovic, Emina; Gilks, C Blake; Mallett, Susan

    The Canadian Immunohistochemistry Quality Control program monitors clinical laboratory performance for estrogen receptor and progesterone receptor tests used in breast cancer treatment management in Canada. Current methods assess sensitivity and specificity at each time point, compared with a reference standard. We investigate alternative performance analysis methods to enhance the quality assessment. We used 3 methods of analysis: meta-analysis of sensitivity and specificity of each laboratory across all time points; sensitivity and specificity at each time point for each laboratory; and fitting models for repeated measurements to examine differences between laboratories adjusted by test and time point. Results show 88 laboratories participated in quality control at up to 13 time points using typically 37 to 54 histology samples. In meta-analysis across all time points no laboratories have sensitivity or specificity below 80%. Current methods, presenting sensitivity and specificity separately for each run, result in wide 95% confidence intervals, typically spanning 15% to 30%. Models of a single diagnostic outcome demonstrated that 82% to 100% of laboratories had no difference to reference standard for estrogen receptor and 75% to 100% for progesterone receptor, with the exception of 1 progesterone receptor run. Laboratories with significant differences to reference standard identified with Generalized Estimating Equation modeling also have reduced performance by meta-analysis across all time points. The Canadian Immunohistochemistry Quality Control program has a good design, and with this modeling approach has sufficient precision to measure performance at each time point and allow laboratories with a significantly lower performance to be targeted for advice.

  18. Identification of the molecular switch that regulates access of 5alpha-DHT to the androgen receptor.

    Science.gov (United States)

    Penning, Trevor M; Bauman, David R; Jin, Yi; Rizner, Tea Lanisik

    2007-02-01

    Pairs of hydroxysteroid dehydrogenases (HSDs) govern ligand access to steroid receptors in target tissues and act as molecular switches. By acting as reductases or oxidases, HSDs convert potent ligands into their cognate inactive metabolites or vice versa. This pre-receptor regulation of steroid hormone action may have profound effects on hormonal response. We have identified the HSDs responsible for regulating ligand access to the androgen receptor (AR) in human prostate. Type 3 3alpha-hydroxysteroid dehydrogenase (aldo-keto reductase 1C2) acts solely as a reductase to convert 5alpha-dihydrotestosterone (DHT), a potent ligand for the AR (K(d)=10(-11)M for the AR), to the inactive androgen 3alpha-androstanediol (K(d)=10(-6)M for the AR); while RoDH like 3alpha-HSD (a short-chain dehydrogenase/reductase (SDR)) acts solely as an oxidase to convert 3alpha-androstanediol back to 5alpha-DHT. Our studies suggest that aldo-keto reductase (AKRs) and SDRs function as reductases and oxidases, respectively, to control ligand access to nuclear receptors.

  19. Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs

    Science.gov (United States)

    Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

    2016-01-01

    Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete’s urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as ‘T-equivalent’ concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact. PMID:26998755

  20. Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs.

    Science.gov (United States)

    Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

    2016-01-01

    Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete's urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as 'T-equivalent' concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact.

  1. DNA methylation of specific CpG sites in the promoter region regulates the transcription of the mouse oxytocin receptor.

    Directory of Open Access Journals (Sweden)

    Shimrat Mamrut

    Full Text Available Oxytocin is a peptide hormone, well known for its role in labor and suckling, and most recently for its involvement in mammalian social behavior. All central and peripheral actions of oxytocin are mediated through the oxytocin receptor, which is the product of a single gene. Transcription of the oxytocin receptor is subject to regulation by gonadal steroid hormones, and is profoundly elevated in the uterus and mammary glands during parturition. DNA methylation is a major epigenetic mechanism that regulates gene transcription, and has been linked to reduced expression of the oxytocin receptor in individuals with autism. Here, we hypothesized that transcription of the mouse oxytocin receptor is regulated by DNA methylation of specific sites in its promoter, in a tissue-specific manner. Hypothalamus-derived GT1-7, and mammary-derived 4T1 murine cell lines displayed negative correlations between oxytocin receptor transcription and methylation of the gene promoter, and demethylation caused a significant enhancement of oxytocin receptor transcription in 4T1 cells. Using a reporter gene assay, we showed that methylation of specific sites in the gene promoter, including an estrogen response element, significantly inhibits transcription. Furthermore, methylation of the oxytocin receptor promoter was found to be differentially correlated with oxytocin receptor expression in mammary glands and the uterus of virgin and post-partum mice, suggesting that it plays a distinct role in oxytocin receptor transcription among tissues and under different physiological conditions. Together, these results support the hypothesis that the expression of the mouse oxytocin receptor gene is epigenetically regulated by DNA methylation of its promoter.

  2. Cyclin D3 interacts with vitamin D receptor and regulates its transcription activity

    International Nuclear Information System (INIS)

    Jian Yongzhi; Yan Jun; Wang Hanzhou; Chen Chen; Sun Maoyun; Jiang Jianhai; Lu Jieqiong; Yang Yanzhong; Gu Jianxin

    2005-01-01

    D-type cyclins are essential for the progression through the G1 phase of the cell cycle. Besides serving as cell cycle regulators, D-type cyclins were recently reported to have transcription regulation functions. Here, we report that cyclin D3 is a new interacting partner of vitamin D receptor (VDR), a member of the superfamily of nuclear receptors for steroid hormones, thyroid hormone, and the fat-soluble vitamins A and D. The interaction was confirmed with methods of yeast two-hybrid system, in vitro binding analysis and in vivo co-immunoprecipitation. Cyclin D3 interacted with VDR in a ligand-independent manner, but treatment of the ligand, 1,25-dihydroxyvitamin D3, strengthened the interaction. Confocal microscopy analysis showed that ligand-activated VDR led to an accumulation of cyclin D3 in the nuclear region. Cyclin D3 up-regulated transcriptional activity of VDR and this effect was counteracted by overexpression of CDK4 and CDK6. These findings provide us a new clue to understand the transcription regulation functions of D-type cyclins

  3. Stress and Cognition: the relevance of timing, steroid receptors and sex differences

    NARCIS (Netherlands)

    Cornelisse, S.

    2013-01-01

    In response to a stressful situation the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis are activated, eventually leading to the release of catecholamines and corticosteroids. These stress hormones bind to different receptors in the brain (in case of corticosteroids,

  4. Brain nuclear receptors and body weight regulation

    Science.gov (United States)

    Neural pathways, especially those in the hypothalamus, integrate multiple nutritional, hormonal, and neural signals, resulting in the coordinated control of body weight balance and glucose homeostasis. Nuclear receptors (NRs) sense changing levels of nutrients and hormones, and therefore play essent...

  5. Novel, non-steroidal, selective androgen receptor modulators (SARMs) with anabolic activity in bone and muscle and improved safety profile.

    Science.gov (United States)

    Rosen, J; Negro-Vilar, A

    2002-03-01

    A novel approach to the treatment of osteoporosis in men, and possibly women, is the development of selective androgen receptor modulators (SARMs) that can stimulate formation of new bone with substantially diminished proliferative activity in the prostate, as well as reduced virilizing activity in women. Over the last several years, we have developed a program to discover and develop novel, non-steroidal, orally-active selective androgen receptor modulators (SARMs) that provide improved therapeutic benefits and reduce risk and side effects. In recent studies, we have used a skeletally mature orchiectomized (ORX) male rat as an animal model of male hypogonadism for assessing the efficacy of LGD2226, a nonsteroidal, non-aromatizable, and non-5alpha-reducible SARM. We assessed the activity of LGD2226 on bone turnover, bone mass and bone strength, and also evaluated the effects exerted on classic androgen-dependent targets, such as prostate, seminal vesicles and muscle. A substantial loss of bone density was observed in ORX animals, and this loss was prevented by SARMs, as well as standard androgens. Biochemical markers of bone turnover revealed an early increase of bone resorption in androgen-deficient rats that was repressed in ORX animals treated with the oral SARM, LGD2226, during a 4-month treatment period. Differences in architectural properties and bone strength were detected by histomorphometric and mechanical analyses, demonstrating beneficial effects of LGD2226 on bone quality in androgen-deficient rats. Histomorphometric analysis of cortical bone revealed distinct anabolic activity of LGD2226 in periosteal bone. LGD2226 was able to prevent bone loss and maintain bone quality in ORX rats by stimulating bone formation, while also inhibiting bone turnover. LGD2226 also exerted anabolic activity on the levator ani muscle. Taken together, these results suggest that orally-active, non-steroidal SARMs may be useful therapeutics for both muscle and bone in elderly

  6. Distribution of aromatase and sex steroid receptors in the baculum during the rat life cycle: effects of estrogen during the early development of the baculum.

    Science.gov (United States)

    Yonezawa, Tomohiro; Higashi, Mayuko; Yoshioka, Kazuki; Mutoh, Ken-ichiro

    2011-07-01

    The baculum, also called os penis, plays an important role during copulation. However, the hormonal regulation of its development remains to be elucidated. To determine the direct involvement of sex steroids in the development of the baculum of rats, the distributions of androgen receptors (ARs), aromatase, and estrogen receptor alpha (ESR1) were observed immunohistochemically. On Postnatal Day 1, the rudiment of the baculum expressed ARs, aromatase, and ESR1. In the proximal segment of the baculum of neonatal rats, ARs were expressed in the parosteal layer but not in the periosteum or osteoblasts. Aromatase was expressed from the parosteal layer to the endosteum, particularly in the inner osteogenic layer. ESR1 was also abundantly expressed in almost all cells from the parosteal layer to the endosteum. ARs, aromatase, and ESR1 were all abundantly expressed during the neonatal period in the hyaline cartilage of the proximal segment and in fibrocartilage of the distal segment of the baculum. Expression in all the tissues was attenuated in an age-dependent manner and became quite weak at puberty. To determine the effect of estrogen on the growth of the baculum, the aromatase inhibitor 1,4,6-androstatrien-3,17-dione (ATD) was subcutaneously injected daily into pregnant rats from Days 19 to 23 of gestation and into pups on postnatal Days 1, 3, 5, 7, and 9. On Day 10, the length of the baculum in the ATD-treated rats was significantly shorter than that in the controls, although the body weight did not change. These findings suggest that not only androgen but also locally aromatized estrogen is involved in the early growth and development of the baculum.

  7. SOCS proteins in regulation of receptor tyrosine kinase signaling

    DEFF Research Database (Denmark)

    Kazi, Julhash U.; Kabir, Nuzhat N.; Flores Morales, Amilcar

    2014-01-01

    Receptor tyrosine kinases (RTKs) are a family of cell surface receptors that play critical roles in signal transduction from extracellular stimuli. Many in this family of kinases are overexpressed or mutated in human malignancies and thus became an attractive drug target for cancer treatment....... The signaling mediated by RTKs must be tightly regulated by interacting proteins including protein-tyrosine phosphatases and ubiquitin ligases. The suppressors of cytokine signaling (SOCS) family proteins are well-known negative regulators of cytokine receptors signaling consisting of eight structurally similar...

  8. Palmitoylation as a Functional Regulator of Neurotransmitter Receptors

    Directory of Open Access Journals (Sweden)

    Vladimir S. Naumenko

    2018-01-01

    Full Text Available The majority of neuronal proteins involved in cellular signaling undergo different posttranslational modifications significantly affecting their functions. One of these modifications is a covalent attachment of a 16-C palmitic acid to one or more cysteine residues (S-palmitoylation within the target protein. Palmitoylation is a reversible modification, and repeated cycles of palmitoylation/depalmitoylation might be critically involved in the regulation of multiple signaling processes. Palmitoylation also represents a common posttranslational modification of the neurotransmitter receptors, including G protein-coupled receptors (GPCRs and ligand-gated ion channels (LICs. From the functional point of view, palmitoylation affects a wide span of neurotransmitter receptors activities including their trafficking, sorting, stability, residence lifetime at the cell surface, endocytosis, recycling, and synaptic clustering. This review summarizes the current knowledge on the palmitoylation of neurotransmitter receptors and its role in the regulation of receptors functions as well as in the control of different kinds of physiological and pathological behavior.

  9. Molecular mechanisms of platelet P2Y(12) receptor regulation.

    Science.gov (United States)

    Cunningham, Margaret R; Nisar, Shaista P; Mundell, Stuart J

    2013-02-01

    Platelets are critical for haemostasis, however inappropriate activation can lead to the development of arterial thrombosis, which can result in heart attack and stroke. ADP is a key platelet agonist that exerts its actions via stimulation of two surface GPCRs (G-protein-coupled receptors), P2Y(1) and P2Y(12). Similar to most GPCRs, P2Y receptor activity is tightly regulated by a number of complex mechanisms including receptor desensitization, internalization and recycling. In the present article, we review the molecular mechanisms that underlie P2Y(1) and P2Y(12) receptor regulation, with particular emphasis on the structural motifs within the P2Y(12) receptor, which are required to maintain regulatory protein interaction. The implications of these findings for platelet responsiveness are also discussed.

  10. Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer

    International Nuclear Information System (INIS)

    Moi, Line L Haugan; Flågeng, Marianne Hauglid; Gjerde, Jennifer; Madsen, Andre; Røst, Therese Halvorsen; Gudbrandsen, Oddrun Anita; Lien, Ernst A; Mellgren, Gunnar

    2012-01-01

    Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0.001). The expression of SRCs and HER-2 and -3 is stimulated

  11. Versican Proteolysis by ADAMTS Proteases and Its Influence on Sex Steroid Receptor Expression in Uterine Leiomyoma.

    Science.gov (United States)

    Gueye, Ndeye-Aicha; Mead, Timothy J; Koch, Christopher D; Biscotti, Charles V; Falcone, Tommaso; Apte, Suneel S

    2017-05-01

    Leiomyomas have abundant extracellular matrix (ECM), with upregulation of versican, a large proteoglycan. We investigated ADAMTS (a disintegrin-like and metalloprotease with thrombospondin type 1 motifs) protease-mediated versican cleavage in myometrium and leiomyoma and the effect of versican knockdown in leiomyoma cells. We used quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, immunohistochemistry, and RNA in situ hybridization for analysis of myometrium, leiomyoma and immortalized myometrium and leiomyoma cells. Short interfering RNA (siRNA) was used to knockdown versican in leiomyoma cells. This study was performed in an academic laboratory. Study subjects were women with symptomatic or asymptomatic leiomyoma. We quantified messenger RNAs (mRNAs) for versican splice variants. We identified ADAMTS-cleaved versican in myometrium and leiomyoma and ADAMTS messenger RNAs and examined the effect of VCAN siRNA on smooth muscle differentiation and expression of estrogen and progesterone receptors. The women in the symptomatic group (n = 7) had larger leiomyoma (P = 0.01), heavy menstrual bleeding (P leiomyomas of symptomatic versus asymptomatic women (P = 0.03 and P = 0.04, respectively). Abundant cleaved versican was detected in leiomyoma and myometrium, as well as in myometrial and leiomyoma cell lines. ADAMTS4 (P = 0.03) and ADAMTS15 (P = 0.04) were upregulated in symptomatic leiomyomas. VCAN siRNA did not effect cell proliferation, apoptosis, or smooth muscle markers, but reduced ESR1 and PR-A expression (P = 0.001 and P = 0.002, respectively). Versican in myometrium, leiomyomas and in the corresponding immortalized cells is cleaved by ADAMTS proteases. VCAN siRNA suppresses production of estrogen receptor 1 and progesterone receptor-A. These findings have implications for leiomyoma growth. Copyright © 2017 by the Endocrine Society

  12. Ovarian steroid hormones modulate the expression of progesterone receptors and histone acetylation patterns in uterine leiomyoma cells.

    Science.gov (United States)

    Sant'Anna, Gabriela Dos Santos; Brum, Ilma Simoni; Branchini, Gisele; Pizzolato, Lolita Schneider; Capp, Edison; Corleta, Helena von Eye

    2017-08-01

    Uterine leiomyomas are the most common benign smooth muscle cell tumors in women. Estrogen (E2), progesterone (P4) and environmental factors play important roles in the development of these tumors. New treatments, such as mifepristone, have been proposed. We evaluated the gene expression of total (PRT) and B (PRB) progesterone receptors, and the histone acetyltransferase (HAT) and deacetylase (HDAC) activity after treatment with E2, P4 and mifepristone (RU486) in primary cell cultures from uterine leiomyoma and normal myometrium. Compared to myometrium, uterine leiomyoma cells showed an increase in PRT mRNA expression when treated with E2, and increase in PRB mRNA expression when treated with E2 and P4. Treatment with mifepristone had no significant impact on mRNA expression in these cells. The HDAC activity was higher in uterine leiomyoma compared to myometrial cells after treatment with E2 and E2 + P4 + mifepristone. HAT activity was barely detectable. Our results suggest that ovarian steroid hormones modulate PR, and mifepristone was unable to decrease PRT and PRB mRNA. The higher activity of HDAC leiomyoma cells could be involved in transcriptional repression of genes implicated in normal myometrium cell function, contributing to the maintenance and growth of uterine leiomyoma.

  13. New method for recognition of sterol signalling molecules: Methinium salts as receptors for sulphated steroids

    Czech Academy of Sciences Publication Activity Database

    Kejík, Z.; Bříza, T.; Králová, Jarmila; Mikula, I.; Poučková, P.; Martásek, P.; Král, V.

    2015-01-01

    Roč. 94, February 2015 (2015), s. 15-20 ISSN 1878-5867 R&D Projects: GA TA ČR(CZ) TE01020028; GA ČR(CZ) GAP303/11/1291; GA MŠk(CZ) LH14008; GA MŠk(CZ) CZ.1.07/2.300/30.0060; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : Polymethinium salts * Sulphated sterols * Molecular recognition * Synthetic receptors Subject RIV: EB - Genetics ; Molecular Biology

  14. Sex steroid hormones matter for learning and memory: estrogenic regulation of hippocampal function in male and female rodents

    Science.gov (United States)

    Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

    2015-01-01

    Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17β-estradiol (E2), affect hippocampal morphology, plasticity, and memory in male and female rodents. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory. This review describes the effects of E2 on hippocampal spinogenesis, neurogenesis, physiology, and memory, with particular attention paid to the effects of E2 in male rodents. The estrogen receptors, cell-signaling pathways, and epigenetic processes necessary for E2 to enhance memory in female rodents are also discussed in detail. Finally, practical considerations for working with female rodents are described for those investigators thinking of adding females to their experimental designs. PMID:26286657

  15. Conformational regulation of urokinase receptor function

    DEFF Research Database (Denmark)

    Gårdsvoll, Henrik; Jacobsen, Benedikte; Kriegbaum, Mette C

    2011-01-01

    PA per se into the hydrophobic ligand binding cavity of uPAR that modulates the function of this receptor. Based on these data, we now propose a model in which the inherent interdomain mobility in uPAR plays a major role in modulating its function. Particularly one uPAR conformation, which is stabilized...

  16. Pharmacology of anabolic steroids.

    Science.gov (United States)

    Kicman, A T

    2008-06-01

    Athletes and bodybuilders have recognized for several decades that the use of anabolic steroids can promote muscle growth and strength but it is only relatively recently that these agents are being revisited for clinical purposes. Anabolic steroids are being considered for the treatment of cachexia associated with chronic disease states, and to address loss of muscle mass in the elderly, but nevertheless their efficacy still needs to be demonstrated in terms of improved physical function and quality of life. In sport, these agents are performance enhancers, this being particularly apparent in women, although there is a high risk of virilization despite the favourable myotrophic-androgenic dissociation that many xenobiotic steroids confer. Modulation of androgen receptor expression appears to be key to partial dissociation, with consideration of both intracellular steroid metabolism and the topology of the bound androgen receptor interacting with co-activators. An anticatabolic effect, by interfering with glucocorticoid receptor expression, remains an attractive hypothesis. Behavioural changes by non-genomic and genomic pathways probably help motivate training. Anabolic steroids continue to be the most common adverse finding in sport and, although apparently rare, designer steroids have been synthesized in an attempt to circumvent the dope test. Doping with anabolic steroids can result in damage to health, as recorded meticulously in the former German Democratic Republic. Even so, it is important not to exaggerate the medical risks associated with their administration for sporting or bodybuilding purposes but to emphasize to users that an attitude of personal invulnerability to their adverse effects is certainly misguided.

  17. Odor memories regulate olfactory receptor expression in the sensory periphery.

    Science.gov (United States)

    Claudianos, Charles; Lim, Julianne; Young, Melanie; Yan, Shanzhi; Cristino, Alexandre S; Newcomb, Richard D; Gunasekaran, Nivetha; Reinhard, Judith

    2014-05-01

    Odor learning induces structural and functional modifications throughout the olfactory system, but it is currently unknown whether this plasticity extends to the olfactory receptors (Or) in the sensory periphery. Here, we demonstrate that odor learning induces plasticity in olfactory receptor expression in the honeybee, Apis mellifera. Using quantitative RT-PCR analysis, we show that six putative floral scent receptors were differentially expressed in the bee antennae depending on the scent environment that the bees experienced. Or151, which we characterized using an in vitro cell expression system as a broadly tuned receptor binding floral odorants such as linalool, and Or11, the specific receptor for the queen pheromone 9-oxo-decenoic acid, were significantly down-regulated after honeybees were conditioned with the respective odorants in an olfactory learning paradigm. Electroantennogram recordings showed that the neural response of the antenna was similarly reduced after odor learning. Long-term odor memory was essential for inducing these changes, suggesting that the molecular mechanisms involved in olfactory memory also regulate olfactory receptor expression. Our study demonstrates for the first time that olfactory receptor expression is experience-dependent and modulated by scent conditioning, providing novel insight into how molecular regulation at the periphery contributes to plasticity in the olfactory system. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Andrographolide regulates epidermal growth factor receptor and transferrin receptor trafficking in epidermoid carcinoma (A-431) cells

    Science.gov (United States)

    Tan, Y; Chiow, KH; Huang, D; Wong, SH

    2010-01-01

    Background and purpose: Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor trafficking will allow us to better understand new mechanisms by which andrographolide may cause death in cancer cells. Experimental approach: We utilized the well-characterized epidermal growth factor receptor (EGFR) and transferrin receptor (TfR) expressed in epidermoid carcinoma (A-431) cells as a model to study the effect of andrographolide on receptor trafficking. Receptor distribution, the total number of receptors and surface receptors were analysed by immunofluorescence, Western blot as well as flow-cytometry respectively. Key results: Andrographolide treatment inhibited cell growth, down-regulated EGFRs on the cell surface and affected the degradation of EGFRs and TfRs. The EGFR was internalized into the cell at an increased rate, and accumulated in a compartment that co-localizes with the lysosomal-associated membrane protein in the late endosomes. Conclusion and implications: This study sheds light on how andrographolide may affect receptor trafficking by inhibiting receptor movement from the late endosomes to lysosomes. The down-regulation of EGFR from the cell surface also indicates a new mechanism by which andrographolide may induce cancer cell death. PMID:20233216

  19. Sex Hormones and Their Receptors Regulate Liver Energy Homeostasis

    Directory of Open Access Journals (Sweden)

    Minqian Shen

    2015-01-01

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

  20. Localización extra nuclear de receptores esteroides y activación de mecanismos no genómicos Extra nuclear localization of steroid receptors and non genomic activation mechanisms

    Directory of Open Access Journals (Sweden)

    María Cecilia Bottino

    2010-04-01

    Full Text Available Los receptores de hormonas esteroides han sido considerados históricamente como factores de transcripción nucleares. Sin embargo, en los últimos años surgieron evidencias que indican que su activación desencadena eventos rápidos, independientes de la transcripción y que involucran a diferentes segundos mensajeros; muchos de estos receptores han sido localizados en la membrana celular. Por otra parte, se han caracterizado varios receptores de hormonas esteroides noveles, de estructura molecular diferente al receptor clásico, localizados principalmente en la membrana celular. Esta revisión enfoca los diferentes efectos iniciados por los glucocorticoides, mineralocorticoides, andrógenos, estrógenos y progesterona, y los posibles receptores involucrados en los mismos.Steroid hormone receptors have been historically considered as nuclear transcription factors. Nevertheless, in the last years, many of them have been detected in the cellular membrane. It has been postulated that their activation can induce transcription independent rapid events involving different second messengers. In addition, several novel steroid hormone receptors, showing a different molecular structure than the classical ones, have also been characterized and most of them are also located in the plasmatic membrane. This review focuses on the variety of effects initiated by glucocorticoids, mineralocorticoids, androgens, estrogens and progesterone, and the possible receptors involved mediating these effects.

  1. Recent Progress in Understanding Subtype Specific Regulation of NMDA Receptors by G Protein Coupled Receptors (GPCRs

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2014-02-01

    Full Text Available G Protein Coupled Receptors (GPCRs are the largest family of receptors whose ligands constitute nearly a third of prescription drugs in the market. They are widely involved in diverse physiological functions including learning and memory. NMDA receptors (NMDARs, which belong to the ionotropic glutamate receptor family, are likewise ubiquitously expressed in the central nervous system (CNS and play a pivotal role in learning and memory. Despite its critical contribution to physiological and pathophysiological processes, few pharmacological interventions aimed directly at regulating NMDAR function have been developed to date. However, it is well established that NMDAR function is precisely regulated by cellular signalling cascades recruited downstream of G protein coupled receptor (GPCR stimulation. Accordingly, the downstream regulation of NMDARs likely represents an important determinant of outcome following treatment with neuropsychiatric agents that target selected GPCRs. Importantly, the functional consequence of such regulation on NMDAR function varies, based not only on the identity of the GPCR, but also on the cell type in which relevant receptors are expressed. Indeed, the mechanisms responsible for regulating NMDARs by GPCRs involve numerous intracellular signalling molecules and regulatory proteins that vary from one cell type to another. In the present article, we highlight recent findings from studies that have uncovered novel mechanisms by which selected GPCRs regulate NMDAR function and consequently NMDAR-dependent plasticity.

  2. Physicochemical and biological properties of novel amide-based steroidal inhibitors of NMDA receptors

    Czech Academy of Sciences Publication Activity Database

    Adla, Santosh Kumar; Slavíková, Barbora; Šmídková, Markéta; Tloušťová, Eva; Svoboda, Martin; Vyklický, Vojtěch; Krausová, Barbora; Hubálková, Pavla; Nekardová, Michaela; Holubová, Kristína; Valeš, Karel; Buděšínský, Miloš; Vyklický ml., Ladislav; Chodounská, Hana; Kudová, Eva

    2017-01-01

    Roč. 117, Jan (2017), s. 52-61 ISSN 0039-128X. [Conference on Isoprenoids /23./. Minsk, 04.09.2016-07.09.2016] R&D Projects: GA TA ČR(CZ) TE01020028; GA ČR(CZ) GAP303/12/1464; GA MŠk LO1302; GA MZd(CZ) NV15-29370A; GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388963 ; RVO:67985823 Keywords : neurosteroid * NMDA receptor * structure-activity relationship * amide * blood-brain-barrier permeability * Caco-2 assay Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry; Organic chemistry (FGU-C) Impact factor: 2.282, year: 2016

  3. Nature and regulation of the insulin receptor: structure and function

    International Nuclear Information System (INIS)

    Czech, M.P.

    1985-01-01

    Native, cell-surface insulin receptor consists of two glycoprotein subunit types with apparent masses of about 125,000 daltons (alpha subunit) and 90,000 daltons (beta subunit). The alpha and beta insulin-receptor subunits seem to have distinct functions such that alpha appears to bind hormone whereas beta appears to possess intrinsic tyrosine kinase activity. In detergent extracts, insulin activates receptor autophosphorylation of tyrosine residues on its beta subunit, whereas in the presence of reductant, the alpha subunit is also phosphorylated. In intact cells, insulin activates serine/threonine phosphorylation of insulin receptor beta subunit as well as tyrosine phosphorylation. The biological role of the receptor-associated tyrosine kinase is not known. The insulin receptor kinase is regulated by beta-adrenergic agonists and other agents that elevate cAMP in adipocytes, presumably via the cAMP-dependent protein kinase. Such agents decrease receptor affinity for insulin and partially uncouple receptor tyrosine kinase activity from activation by insulin. These effects appear to contribute to the biological antagonism between insulin and beta-agonists. These data suggest the hypothesis that a complex network of tyrosine and serine/threonine phosphorylations on the insulin receptor modulate its binding and kinase activities in an antagonistic manner

  4. Effects of cypermethrin on the ligand-independent interaction between androgen receptor and steroid receptor coactivator-1

    International Nuclear Information System (INIS)

    Pan, Chen; Liu, Ya-Peng; Li, Yan-Fang; Hu, Jin-Xia; Zhang, Jin-Peng; Wang, Hong-Mei; Li, Jing; Xu, Li-Chun

    2012-01-01

    The pyrethroid insecticide, cypermethrin has been considered as an environmental anti-androgen by interfering with the androgen receptor (AR) transactivation. In order to clarify the effects of cypermethrin on the ligand-independent interaction between the AR and SRC-1, the mammalian two-hybrid assay has been developed in the study. The AR N-terminal domain 1–660 amino acid residues were subcloned into the plasmid pVP16 to construct the vector pVP16-ARNTD. The SRC-1 C-terminal domain 989–1240 amino acid residues were subcloned into the plasmid pM to construct the vector pM-SRC-1. The fusion vectors pVP16-ARNTD, pM-SRC-1 and the pG5CAT Reporter Vector were cotransfected into the CV-1 cells. The AR AF1 interacted with SRC-1 in the absence of exogenous ligand 5α-dihydrotestosterone (DHT). Furthermore, DHT did not enhance the interaction between AR AF-1 and SRC-1 at the concentrations from 10 −10 M to 10 −8 M. Cypermethrin inhibited the interaction between the AR AF1 and SRC-1, and the significant reduction was detected at the concentration of 10 −5 M. It is suggested that the interaction between the AR AF1 and SRC-1 is ligand-independent. Cypermethrin inhibits AR activity by disrupting the ligand-independent AR–SRC-1 interaction.

  5. The anabolic steroid nandrolone alters cannabinoid self-administration and brain CB1 receptor density and function

    NARCIS (Netherlands)

    Struik, Dicky; Fadda, Paola; Zara, Tamara; Zamberletti, Erica; Rubino, Tiziana; Parolaro, Daniela; Fratta, Walter; Fattore, Liana

    Clinical and pre-clinical observations indicate that anabolic-androgenic steroids can induce neurobiological changes that alter the rewarding effects of drugs of abuse. In this study, we investigated the effect of the anabolic steroid nandrolone on the rewarding properties of the cannabinoid CBI

  6. Botanical compounds and their regulation of nuclear receptor action: the case of traditional Chinese medicine.

    Science.gov (United States)

    Li, Ling; Bonneton, François; Chen, Xiao Yong; Laudet, Vincent

    2015-02-05

    Nuclear receptors (NRs) are major pharmacological targets that allow an access to the mechanisms controlling gene regulation. As such, some NRs were identified as biological targets of active compounds contained in herbal remedies found in traditional medicines. We aim here to review this expanding literature by focusing on the informative articles regarding the mechanisms of action of traditional Chinese medicines (TCMs). We exemplified well-characterized TCM action mediated by NR such as steroid receptors (ER, GR, AR), metabolic receptors (PPAR, LXR, FXR, PXR, CAR) and RXR. We also provided, when possible, examples from other traditional medicines. From these, we draw a parallel between TCMs and phytoestrogens or endocrine disrupting chemicals also acting via NR. We define common principle of action and highlight the potential and limits of those compounds. TCMs, by finely tuning physiological reactions in positive and negative manners, could act, in a subtle but efficient way, on NR sensors and their transcriptional network. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Combined Ligand/Structure-Based Virtual Screening and Molecular Dynamics Simulations of Steroidal Androgen Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Yuwei Wang

    2017-01-01

    Full Text Available The antiandrogens, such as bicalutamide, targeting the androgen receptor (AR, are the main endocrine therapies for prostate cancer (PCa. But as drug resistance to antiandrogens emerges in advanced PCa, there presents a high medical need for exploitation of novel AR antagonists. In this work, the relationships between the molecular structures and antiandrogenic activities of a series of 7α-substituted dihydrotestosterone derivatives were investigated. The proposed MLR model obtained high predictive ability. The thoroughly validated QSAR model was used to virtually screen new dihydrotestosterones derivatives taken from PubChem, resulting in the finding of novel compounds CID_70128824, CID_70127147, and CID_70126881, whose in silico bioactivities are much higher than the published best one, even higher than bicalutamide. In addition, molecular docking, molecular dynamics (MD simulations, and MM/GBSA have been employed to analyze and compare the binding modes between the novel compounds and AR. Through the analysis of the binding free energy and residue energy decomposition, we concluded that the newly discovered chemicals can in silico bind to AR with similar position and mechanism to the reported active compound and the van der Waals interaction is the main driving force during the binding process.

  8. Receptor localization of steroid hormones and drugs: discoveries through the use of thaw-mount and dry-mount autoradiography

    Directory of Open Access Journals (Sweden)

    Stumpf W.E.

    1998-01-01

    Full Text Available The history of receptor autoradiography, its development and applications, testify to the utility of this histochemical technique for localizing radiolabeled hormones and drugs at cellular and subcellular sites of action in intact tissues. Localization of diffusible compounds has been a challenge that was met through the introduction of the "thaw-mount" and "dry-mount" autoradiographic techniques thirty years ago. With this cellular receptor autoradiography, used alone or combined with other histochemical techniques, sites of specific binding and deposition in vivo and in vitro have been characterized. Numerous discoveries, some reviewed in this article, provided information that led to new concepts and opened new areas of research. As an example, in recent years more than fifty target tissues for vitamin D have been specified, challenging the conventional view about the main biological role of vitamin D. The functions of most of these vitamin D target tissues are unrelated to the regulation of systemic calcium homeostasis, but pertain to the (seasonal regulation of endo- and exocrine secretion, cell proliferation, reproduction, neural, immune and cardiovascular responses, and adaptation to stress. Receptor autoradiography with cellular resolution has become an indispensable tool in drug research and development, since information can be obtained that is difficult or impossible to gain otherwise

  9. Characterization of Steroid Receptor RNA Activator Protein Function in Modulating the Estrogen Signaling Pathway

    Science.gov (United States)

    2008-03-01

    two opposite directions. Material and methods Alignment of SRAP sequences: Putative SRAP sequence from Homo sapiens , Bos Taurus, Mus musculus...0.5 1 1.5 2 control IP IP +V5 competition R el at iv e H D A C a ct iv ity IP IP + V5 * MCF-7cont MCF-7 SRAP-V5 High.A cells Fig 7 Appendix 5...1 0 1 2 3 PRO WT NONE RNA UT D el ta C T ** A B C Figure 4: SRAP down regulates the ERbeta expression in mRNA level. A) Four plenti-SRA constructs

  10. Steroidogenesis and early response gene expression in MA-10 Leydig tumor cells following heterologous receptor down-regulation and cellular desensitization

    Directory of Open Access Journals (Sweden)

    Tsuey-Ming Chen

    2016-03-01

    Full Text Available The Leydig tumor cell line, MA-10, expresses the luteinizing hormone receptor, a G protein-coupled receptor that, when activated with luteinizing hormone or chorionic gonadotropin (CG, stimulates cAMP production and subsequent steroidogenesis, notably progesterone. These cells also respond to epidermal growth factor (EGF and phorbol esters with increased steroid biosynthesis. In order to probe the intracellular pathways along with heterologous receptor down-regulation and cellular desensitization, cells were preincubated with EGF or phorbol esters and then challenged with CG, EGF, dibutryl-cyclic AMP, and a phorbol ester. Relative receptor numbers, steroid biosynthesis, and expression of the early response genes, JUNB and c-FOS, were measured. It was found that in all cases but one receptor down-regulation and decreased progesterone production were closely coupled under the conditions used; the exception involved preincubation of the cells with EGF followed by addition of CG where the CG-mediated stimulation of steroidogenesis was considerably lower than the level of receptor down-regulation. In a number of instances JUNB and c-FOS expression paralleled the decreases in receptor number and progesterone production, while in some cases these early response genes were affected little if at all by the changes in receptor number. This finding may indicate that even low levels of activated signaling kinases, e.g. protein kinase A, protein kinase C, or receptor tyrosine kinase, may suffice to yield good expression of JUNB and c-FOS, or it may suggest alternative pathways for regulating expression of these two early response genes.

  11. Role of endocrine disrupting chemicals on the tissue levels of AhR and sex steroid receptors in breast tumours

    Directory of Open Access Journals (Sweden)

    Sepideh Arbabi Bidgoli

    2016-09-01

    Full Text Available Breast cancer affects Iranian women at least one decade younger than their counterparts in other countries and the incidence of breast fibroadenoma is growing in the last two decades in Tehran. This study aimed to compare the AhR levels in premenopausal breast cancer and breast fibroadnemo with appropriate normal groups. Possible associations of AhR with lifestyle and reproductive risk factors and other fundamental genes of breast cancer and reproductive disorders were the other major goals of present study. To conduct the comparisons all possible reproductive, environmental and lifestyle risk factors of mentioned diseases were recorded in 100 breast cancer, 100 breast fibroadenoma and compared with 400 women in normal group from 2009 to 2011. AhR overexpression in epithelial cells of premenopausal patients emphasized the susceptibility of these cells to environmental induced reproductive disorders. The AhR overexpression was contributed to ER-/PgR- immunophenotype in malignant tissues. Weight gain (after 18 and after pregnancy, long term (>5yrs OCP consumption, smoking, severe stress ,history of ovarian cysts, hormonal deregulations, living near PAHs producing sources, were correlated with increased risk of breast cancer and reproductive disorders and were correlated with elevated tissue levels of AhR. It seems that increased risk of breast cancer and other reproductive tumours in Tehran may be the result of exposure to environmental endocrine disruptors. Long term exposure to environmental estrogens can increase the tissue levels of AhR and deregulate the expression pattern of sex steroid receptors and other genes in target tissues.

  12. N-glycosylation of the β2 adrenergic receptor regulates receptor function by modulating dimerization.

    Science.gov (United States)

    Li, Xiaona; Zhou, Mang; Huang, Wei; Yang, Huaiyu

    2017-07-01

    N-glycosylation is a common post-translational modification of G-protein-coupled receptors (GPCRs). However, it remains unknown how N-glycosylation affects GPCR signaling. β 2 adrenergic receptor (β 2 AR) has three N-glycosylation sites: Asn6, Asn15 at the N-terminus, and Asn187 at the second extracellular loop (ECL2). Here, we show that deletion of the N-glycan did not affect receptor expression and ligand binding. Deletion of the N-glycan at the N-terminus rather than Asn187 showed decreased effects on isoproterenol-promoted G-protein-dependent signaling, β-arrestin2 recruitment, and receptor internalization. Both N6Q and N15Q showed decreased receptor dimerization, while N187Q did not influence receptor dimerization. As decreased β 2 AR homodimer accompanied with reduced efficiency for receptor function, we proposed that the N-glycosylation of β 2 AR regulated receptor function by influencing receptor dimerization. To verify this hypothesis, we further paid attention to the residues at the dimerization interface. Studies of Lys60 and Glu338, two residues at the receptor dimerization interface, exhibited that the K60A/E338A showed decreased β 2 AR dimerization and its effects on receptor signaling were similar to N6Q and N15Q, which further supported the importance of receptor dimerization for receptor function. This work provides new insights into the relationship among glycosylation, dimerization, and function of GPCRs. Peptide-N-glycosidase F (PNGase F, EC 3.2.2.11); endo-β-N-acetylglucosaminidase A (Endo-A, EC 3.2.1.96). © 2017 Federation of European Biochemical Societies.

  13. Quantitative immunolocalization of {mu} opioid receptors: regulation by naltrexone

    Energy Technology Data Exchange (ETDEWEB)

    Evans, C.J.; Lam, H.; To, T.; Anton, B. [Department of Psychiatry and Biobehavioral Sciences, Neuropsychiatric Institute, University of California, Los Angeles, CA (United States); Unterwald, E.M. [Department of Psychiatry, New York University Medical Center, New York, NY (United States)

    1998-04-24

    observable change in the total number of receptors. Quantitative receptor immunodetection together with ligand autoradiography provides a new approach for investigating the regulation of {mu} opioid receptors on tissue sections. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Quantitative immunolocalization of μ opioid receptors: regulation by naltrexone

    International Nuclear Information System (INIS)

    Evans, C.J.; Lam, H.; To, T.; Anton, B.; Unterwald, E.M.

    1998-01-01

    of receptors. Quantitative receptor immunodetection together with ligand autoradiography provides a new approach for investigating the regulation of μ opioid receptors on tissue sections. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Steroid receptor coactivator 1 deficiency increases MMTV-neu mediated tumor latency and differentiation specific gene expression, decreases metastasis, and inhibits response to PPAR ligands

    International Nuclear Information System (INIS)

    Han, Ji Seung; Crowe, David L

    2010-01-01

    The peroxisome proliferator activated receptor (PPAR) subgroup of the nuclear hormone receptor superfamily is activated by a variety of natural and synthetic ligands. PPARs can heterodimerize with retinoid X receptors, which have homology to other members of the nuclear receptor superfamily. Ligand binding to PPAR/RXRs results in recruitment of transcriptional coactivator proteins such as steroid receptor coactivator 1 (SRC-1) and CREB binding protein (CBP). Both SRC-1 and CBP are histone acetyltransferases, which by modifying nucleosomal histones, produce more open chromatin structure and increase transcriptional activity. Nuclear hormone receptors can recruit limiting amounts of coactivators from other transcription factor binding sites such as AP-1, thereby inhibiting the activity of AP-1 target genes. PPAR and RXR ligands have been used in experimental breast cancer therapy. The role of coactivator expression in mammary tumorigenesis and response to drug therapy has been the subject of recent studies. We examined the effects of loss of SRC-1 on MMTV-neu mediated mammary tumorigenesis. SRC-1 null mutation in mammary tumor prone mice increased the tumor latency period, reduced tumor proliferation index and metastasis, inhibited response to PPAR and RXR ligands, and induced genes involved in mammary gland differentiation. We also examined human breast cancer cell lines overexpressing SRC-1 or CBP. Coactivator overexpression increased cellular proliferation with resistance to PPAR and RXR ligands and remodeled chromatin of the proximal epidermal growth factor receptor promoter. These results indicate that histone acetyltransferases play key roles in mammary tumorigenesis and response to anti-proliferative therapies

  16. Dynamic regulation of Drosophila nuclear receptor activity in vivo.

    Science.gov (United States)

    Palanker, Laura; Necakov, Aleksandar S; Sampson, Heidi M; Ni, Ruoyu; Hu, Chun; Thummel, Carl S; Krause, Henry M

    2006-09-01

    Nuclear receptors are a large family of transcription factors that play major roles in development, metamorphosis, metabolism and disease. To determine how, where and when nuclear receptors are regulated by small chemical ligands and/or protein partners, we have used a 'ligand sensor' system to visualize spatial activity patterns for each of the 18 Drosophila nuclear receptors in live developing animals. Transgenic lines were established that express the ligand binding domain of each nuclear receptor fused to the DNA-binding domain of yeast GAL4. When combined with a GAL4-responsive reporter gene, the fusion proteins show tissue- and stage-specific patterns of activation. We show that these responses accurately reflect the presence of endogenous and exogenously added hormone, and that they can be modulated by nuclear receptor partner proteins. The amnioserosa, yolk, midgut and fat body, which play major roles in lipid storage, metabolism and developmental timing, were identified as frequent sites of nuclear receptor activity. We also see dynamic changes in activation that are indicative of sweeping changes in ligand and/or co-factor production. The screening of a small compound library using this system identified the angular psoralen angelicin and the insect growth regulator fenoxycarb as activators of the Ultraspiracle (USP) ligand-binding domain. These results demonstrate the utility of this system for the functional dissection of nuclear receptor pathways and for the development of new receptor agonists and antagonists that can be used to modulate metabolism and disease and to develop more effective means of insect control.

  17. Cellular localization of steroid hormone-regulated proteins during sexual development in achlya

    International Nuclear Information System (INIS)

    Brunt, S.A.; Silver, J.C.

    1986-01-01

    In the fungus Achlya ambisexualis sexual development in the male strain E87 is controlled by the steroid hormone antheridiol. To investigate the effects of antheridiol on the synthesis and/or accumulation of specific cellular proteins we have analyzed [ 35 S]methionine-labeled proteins from control and hormone-treated cells using both one-dimensional (1D) and two-dimensional (2D) PAGE. The addition of the hormone antheridiol to vegetatively growing cells of Achlya E87 was found to result in changes in the synthesis and/or accumulation of at least 16 specific proteins, which could be localized to the cytoplasmic, nuclear or cell was/cell membrane fractions. The most prominent changes observed in the hormone-treated cells included the appearance in the cytoplasmic fraction of labeled proteins at 28.4 and 24.3kD which were not detectable in control cells, and a significant enrichment in the labeling of a 24.3kD protein in the cell wall/cell membrane fraction. Quantitative changes in the [ 35 S]methionine labeling of several other proteins were noted in all three cell fractions

  18. Gonadotropins, their receptors, and the regulation of testicular functions in fish

    NARCIS (Netherlands)

    Schulz, Rüdiger W; Vischer, H F; Cavaco, J E; Dos Santos Rocha, M.E.; Tyler, R.C.; Goos, H.J.; Bogerd, J.

    The pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) regulate steroidogenesis and spermatogenesis by activating receptors expressed by Leydig cells (LH receptor) and Sertoli cells (FSH receptor), respectively. This concept is also valid in fish, although the

  19. Regulation of G Protein-Coupled Receptors by Ubiquitination

    Directory of Open Access Journals (Sweden)

    Kamila Skieterska

    2017-04-01

    Full Text Available G protein-coupled receptors (GPCRs comprise the largest family of membrane receptors that control many cellular processes and consequently often serve as drug targets. These receptors undergo a strict regulation by mechanisms such as internalization and desensitization, which are strongly influenced by posttranslational modifications. Ubiquitination is a posttranslational modification with a broad range of functions that is currently gaining increased appreciation as a regulator of GPCR activity. The role of ubiquitination in directing GPCRs for lysosomal degradation has already been well-established. Furthermore, this modification can also play a role in targeting membrane and endoplasmic reticulum-associated receptors to the proteasome. Most recently, ubiquitination was also shown to be involved in GPCR signaling. In this review, we present current knowledge on the molecular basis of GPCR regulation by ubiquitination, and highlight the importance of E3 ubiquitin ligases, deubiquitinating enzymes and β-arrestins. Finally, we discuss classical and newly-discovered functions of ubiquitination in controlling GPCR activity.

  20. Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

    International Nuclear Information System (INIS)

    Wang, Yandi; Zhao, Yong; Yu, Shuai; Feng, Yanni; Zhang, Hongfu; Kou, Xin; Chu, Meiqiang; Cui, Liantao; Li, Lan; Zhang, Pengfei; Shen, Wei; Min, Lingjiang

    2016-01-01

    Although it is well known that cysteamine is a potent chemical for treating many diseases including cystinosis and it has many adverse effects, the effect of cysteamine on spermatogenesis is as yet unknown. Therefore the objective of this investigation was to explore the effects of cysteamine on spermatogenesis and the underlying mechanisms. Sheep were treated with vehicle control, 10 mg/kg or 20 mg/kg cysteamine for six months. After that, the semen samples were collected to determine the spermatozoa motility by computer-assisted sperm assay method. Blood samples were collected to detect the levels of hormones and the activity of enzymes. Spermatozoa and testis samples were collected to study the mechanism of cysteamine's actions. It was found that the effects of cysteamine on spermatogenesis were dose dependent. A low dose (10 mg/kg) cysteamine treatment increased ovine spermatozoa motility; however, a higher dose (20 mg/kg) decreased both spermatozoa concentration and motility. This decrease might be due to a reduction in steroid hormone production by the testis, a reduction in energy in the testis and spermatozoa, a disruption in the blood-testis barrier, or a breakdown in the vital signaling pathways involved in spermatogenesis. The inhibitory effects of cysteamine on sheep spermatogenesis may be used to model its effects on young male patients with cystinosis or other diseases that are treated with this drug. Further studies on spermatogenesis that focus on patients treated with cysteamine during the peripubertal stage are warranted. - Highlights: • Dose dependent effects of cysteamine on spermatogenesis • A low dose (10 mg/kg) increased spermatozoa motility. • A higher dose (20 mg/kg) decreased both concentration and motility of spermatozoa. • Disruption in the blood-testis barrier caused reduction in concentration and motility.

  1. Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yandi [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhao, Yong [Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109 (China); Yu, Shuai; Feng, Yanni [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhang, Hongfu [State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing (China); Kou, Xin [Shouguang Hongde Farmer Co., Weifang 262700 (China); Chu, Meiqiang; Cui, Liantao; Li, Lan [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhang, Pengfei [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109 (China); Shen, Wei [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Min, Lingjiang, E-mail: mlj020963@hotmail.com [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China)

    2016-12-15

    Although it is well known that cysteamine is a potent chemical for treating many diseases including cystinosis and it has many adverse effects, the effect of cysteamine on spermatogenesis is as yet unknown. Therefore the objective of this investigation was to explore the effects of cysteamine on spermatogenesis and the underlying mechanisms. Sheep were treated with vehicle control, 10 mg/kg or 20 mg/kg cysteamine for six months. After that, the semen samples were collected to determine the spermatozoa motility by computer-assisted sperm assay method. Blood samples were collected to detect the levels of hormones and the activity of enzymes. Spermatozoa and testis samples were collected to study the mechanism of cysteamine's actions. It was found that the effects of cysteamine on spermatogenesis were dose dependent. A low dose (10 mg/kg) cysteamine treatment increased ovine spermatozoa motility; however, a higher dose (20 mg/kg) decreased both spermatozoa concentration and motility. This decrease might be due to a reduction in steroid hormone production by the testis, a reduction in energy in the testis and spermatozoa, a disruption in the blood-testis barrier, or a breakdown in the vital signaling pathways involved in spermatogenesis. The inhibitory effects of cysteamine on sheep spermatogenesis may be used to model its effects on young male patients with cystinosis or other diseases that are treated with this drug. Further studies on spermatogenesis that focus on patients treated with cysteamine during the peripubertal stage are warranted. - Highlights: • Dose dependent effects of cysteamine on spermatogenesis • A low dose (10 mg/kg) increased spermatozoa motility. • A higher dose (20 mg/kg) decreased both concentration and motility of spermatozoa. • Disruption in the blood-testis barrier caused reduction in concentration and motility.

  2. Sex Steroid Actions in Male Bone

    Science.gov (United States)

    Laurent, Michaël R.; Claessens, Frank; Gielen, Evelien; Lagerquist, Marie K.; Vandenput, Liesbeth; Börjesson, Anna E.; Ohlsson, Claes

    2014-01-01

    Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority. PMID:25202834

  3. Regulation of AMPA Receptor Trafficking by Protein Ubiquitination

    Directory of Open Access Journals (Sweden)

    Jocelyn Widagdo

    2017-10-01

    Full Text Available The molecular mechanisms underlying plastic changes in the strength and connectivity of excitatory synapses have been studied extensively for the past few decades and remain the most attractive cellular models of learning and memory. One of the major mechanisms that regulate synaptic plasticity is the dynamic adjustment of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA-type glutamate receptor content on the neuronal plasma membrane. The expression of surface AMPA receptors (AMPARs is controlled by the delicate balance between the biosynthesis, dendritic transport, exocytosis, endocytosis, recycling and degradation of the receptors. These processes are dynamically regulated by AMPAR interacting proteins as well as by various post-translational modifications that occur on their cytoplasmic domains. In the last few years, protein ubiquitination has emerged as a major regulator of AMPAR intracellular trafficking. Dysregulation of AMPAR ubiquitination has also been implicated in the pathophysiology of Alzheimer’s disease. Here we review recent advances in the field and provide insights into the role of protein ubiquitination in regulating AMPAR membrane trafficking and function. We also discuss how aberrant ubiquitination of AMPARs contributes to the pathogenesis of various neurological disorders, including Alzheimer’s disease, chronic stress and epilepsy.

  4. Identification of selected in vitro generated phase-I metabolites of the steroidal selective androgen receptor modulator MK-0773 for doping control purposes.

    Science.gov (United States)

    Lagojda, Andreas; Kuehne, Dirk; Krug, Oliver; Thomas, Andreas; Wigger, Tina; Karst, Uwe; Schänzer, Wilhelm; Thevis, Mario

    2016-01-01

    Research into developing anabolic agents for various therapeutic purposes has been pursued for decades. As the clinical utility of anabolic-androgenic steroids has been found to be limited because of their lack of tissue selectivity and associated off-target effects, alternative drug entities have been designed and are commonly referred to as selective androgen receptor modulators (SARMs). While most of these SARMs are of nonsteroidal structure, the drug candidate MK-0773 comprises a 4-aza-steroidal nucleus. Besides the intended therapeutic use, SARMs have been found to be illicitly distributed and misused as doping agents in sport, necessitating frequently updated doping control analytical assays. As steroidal compounds reportedly undergo considerable metabolic transformations, the phase-I metabolism of MK-0773 was simulated using human liver microsomal (HLM) preparations and electrochemical conversion. Subsequently, major metabolic products were identified and characterized employing liquid chromatography-high-resolution/high- accuracy tandem mass spectrometry with electrospray (ESI) and atmospheric pressure chemical ionization (APCI) as well as nuclear magnetic resonance (NMR) spectroscopy. MK-0773 produced numerous phase-I metabolites under the chosen in vitro incubation reactions, mostly resulting from mono- and bisoxygenation of the steroid. HLM yielded at least 10 monooxygenated species, while electrochemistry-based experiments resulted predominantly in three monohydroxylated metabolites. Elemental composition data and product ion mass spectra were generated for these analytes, ESI/APCI measurements corroborated the formation of at least two N-oxygenated metabolites, and NMR data obtained from electrochemistry-derived products supported structures suggested for three monohydroxylated compounds. Hereby, the hydroxylation of the A-ring located N- bound methyl group was found to be of particular intensity. In the absence of controlled elimination studies, the

  5. Classical and Nonclassical Estrogen Receptor Action on Chromatin Templates

    National Research Council Canada - National Science Library

    Nordeen, Steven

    2000-01-01

    .... Using newly-developed approaches, I investigated mechanisms of estrogen/estrogen receptor action on chromatin templates in vitro in order to better understand the role of chromatin in steroid-regulated gene expression...

  6. Classical and Nonclassical Estrogen Receptor Action on Chromatin Templaces

    National Research Council Canada - National Science Library

    Nordeen, Steve

    2001-01-01

    .... Using newly-developed approaches, I investigated mechanisms of estrogen/estrogen receptor action on chromatin templates in vitro in order to better understand the role of chromatin in steroid-regulated gene expression...

  7. Regulation of AMPA receptor localization in lipid rafts

    Science.gov (United States)

    Hou, Qingming; Huang, Yunfei; Amato, Stephen; Snyder, Solomon H.; Huganir, Richard L.; Man, Heng-Ye

    2009-01-01

    Lipid rafts are special microdomains enriched in cholesterol, sphingolipids and certain proteins, and play important roles in a variety of cellular functions including signal transduction and protein trafficking. We report that in cultured cortical and hippocampal neurons the distribution of lipid rafts is development-dependent. Lipid rafts in mature neurons exist on the entire cell-surface and display a high degree of mobility. AMPA receptors co-localize and associate with lipid rafts in the plasma membrane. The association of AMPARs with rafts is under regulation; through the NOS–NO pathway, NMDA receptor activity increases AMPAR localization in rafts. During membrane targeting, AMPARs insert into or at close proximity of the surface raft domains. Perturbation of lipid rafts dramatically suppresses AMPA receptor exocytosis, resulting in significant reduction in AMPAR cell-surface expression. PMID:18411055

  8. Steroidal Saponins

    Science.gov (United States)

    Sahu, N. P.; Banerjee, S.; Mondal, N. B.; Mandal, D.

    The medicinal activities of plants are generally due to the secondary metabolites (1) which often occur as glycosides of steroids, terpenoids, phenols etc. Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. The cardiac glycosides also possess this, property but are classified separately because of their specific biological activity. Unlike the cardiac glycosides, saponins generally do not affect the heart. These are classified as steroid or triterpenoid saponins depending on the nature of the aglycone. Steroidal glycosides are naturally occurring sugar conjugates of C27 steroidal compounds. The aglycone of a steroid saponin is usually a spirostanol or a furostanol. The glycone parts of these compounds are mostly oligosaccharides, arranged either in a linear or branched fashion, attached to hydroxyl groups through an acetal linkage (2, 3). Another class of saponins, the basic steroid saponins, contain nitrogen analogues of steroid sapogenins as aglycones.

  9. In silico comparative genomic analysis of GABAA receptor transcriptional regulation

    Directory of Open Access Journals (Sweden)

    Joyce Christopher J

    2007-06-01

    Full Text Available Abstract Background Subtypes of the GABAA receptor subunit exhibit diverse temporal and spatial expression patterns. In silico comparative analysis was used to predict transcriptional regulatory features in individual mammalian GABAA receptor subunit genes, and to identify potential transcriptional regulatory components involved in the coordinate regulation of the GABAA receptor gene clusters. Results Previously unreported putative promoters were identified for the β2, γ1, γ3, ε, θ and π subunit genes. Putative core elements and proximal transcriptional factors were identified within these predicted promoters, and within the experimentally determined promoters of other subunit genes. Conserved intergenic regions of sequence in the mammalian GABAA receptor gene cluster comprising the α1, β2, γ2 and α6 subunits were identified as potential long range transcriptional regulatory components involved in the coordinate regulation of these genes. A region of predicted DNase I hypersensitive sites within the cluster may contain transcriptional regulatory features coordinating gene expression. A novel model is proposed for the coordinate control of the gene cluster and parallel expression of the α1 and β2 subunits, based upon the selective action of putative Scaffold/Matrix Attachment Regions (S/MARs. Conclusion The putative regulatory features identified by genomic analysis of GABAA receptor genes were substantiated by cross-species comparative analysis and now require experimental verification. The proposed model for the coordinate regulation of genes in the cluster accounts for the head-to-head orientation and parallel expression of the α1 and β2 subunit genes, and for the disruption of transcription caused by insertion of a neomycin gene in the close vicinity of the α6 gene, which is proximal to a putative critical S/MAR.

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

    Science.gov (United States)

    Endo, Daisuke; Park, Min Kyun

    2003-12-01

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

  11. BNN27, a 17-Spiroepoxy Steroid Derivative, Interacts With and Activates p75 Neurotrophin Receptor, Rescuing Cerebellar Granule Neurons from Apoptosis.

    Science.gov (United States)

    Pediaditakis, Iosif; Kourgiantaki, Alexandra; Prousis, Kyriakos C; Potamitis, Constantinos; Xanthopoulos, Kleanthis P; Zervou, Maria; Calogeropoulou, Theodora; Charalampopoulos, Ioannis; Gravanis, Achille

    2016-01-01

    Neurotrophin receptors mediate a plethora of signals affecting neuronal survival. The p75 pan-neurotrophin receptor controls neuronal cell fate after its selective activation by immature and mature isoforms of all neurotrophins. It also exerts pleiotropic effects interacting with a variety of ligands in different neuronal or non-neuronal cells. In the present study, we explored the biophysical and functional interactions of a blood-brain-barrier (BBB) permeable, C17-spiroepoxy steroid derivative, BNN27, with p75 NTR receptor. BNN27 was recently shown to bind to NGF high-affinity receptor, TrkA. We now tested the p75 NTR -mediated effects of BNN27 in mouse Cerebellar Granule Neurons (CGNs), expressing p75 NTR , but not TrkA receptors. Our findings show that BNN27 physically interacts with p75 NTR receptors in specific amino-residues of its extracellular domain, inducing the recruitment of p75 NTR receptor to its effector protein RIP2 and the simultaneous release of RhoGDI in primary neuronal cells. Activation of the p75 NTR receptor by BNN27 reverses serum deprivation-induced apoptosis of CGNs resulting in the decrease of the phosphorylation of pro-apoptotic JNK kinase and of the cleavage of Caspase-3, effects completely abolished in CGNs, isolated from p75 NTR null mice. In conclusion, BNN27 represents a lead molecule for the development of novel p75 NTR ligands, controlling specific p75 NTR -mediated signaling of neuronal cell fate, with potential applications in therapeutics of neurodegenerative diseases and brain trauma.

  12. New insights into how trafficking regulates T cell receptor signaling

    Directory of Open Access Journals (Sweden)

    Jieqiong Lou

    2016-07-01

    Full Text Available AbstractThere is emerging evidence that exocytosis plays an important role in regulating T cell receptor (TCR signaling. The trafficking molecules involved in lytic granule (LG secretion in cytotoxic T lymphocytes (CTL have been well studied due to the immune disorder known as familial hemophagocytic lymphohisiocytosis (FHLH. However, the knowledge of trafficking machineries regulating the exocytosis of receptors and signaling molecules remains quite limited. In this review, we summarize the reported trafficking molecules involved in the transport of the TCR and downstream signaling molecules to the cell surface. By combining this information with the known knowledge of LG exocytosis and general exocytic trafficking machinery, we attempt to draw a more complete picture of how the TCR signaling network and exocytic trafficking matrix are interconnected to facilitate T cell activation. This also highlights how membrane compartmentalization facilitates the spatiotemporal organization of cellular responses that are essential for immune functions.

  13. TTP specifically regulates the internalization of the transferrin receptor

    DEFF Research Database (Denmark)

    Tosoni, Daniela; Puri, Claudia; Confalonieri, Stefano

    2005-01-01

    Different plasma membrane receptors are internalized through saturable/noncompetitive pathways, suggesting cargo-specific regulation. Here, we report that TTP (SH3BP4), a SH3-containing protein, specifically regulates the internalization of the transferrin receptor (TfR). TTP interacts...... with endocytic proteins, including clathrin, dynamin, and the TfR, and localizes selectively to TfR-containing coated-pits (CCP) and -vesicles (CCV). Overexpression of TTP specifically inhibits TfR internalization, and causes the formation of morphologically aberrant CCP, which are probably fission impaired....... This effect is mediated by the SH3 of TTP, which can bind to dynamin, and it is rescued by overexpression of dynamin. Functional ablation of TTP causes a reduction in TfR internalization, and reduced cargo loading and size of TfR-CCV. Tyrosine phosphorylation of either TTP or dynamin prevents...

  14. Nuclear Progestin Receptor (Pgr Knockouts in Zebrafish Demonstrate Role for Pgr in Ovulation But Not in Rapid Nongenomic Steroid Mediated Meiosis Resumption

    Directory of Open Access Journals (Sweden)

    Yong eZhu

    2015-03-01

    Full Text Available Progestins, progesterone derivatives, are the most critical signaling steroid for initiating final oocyte maturation (FOM and ovulation, in order to advance fully-grown immature oocytes to become fertilizable eggs in basal vertebrates. It is well-established that progestin induces FOM via an elusive membrane receptor and a nongenomic steroid signaling process, which precedes progestin triggered ovulation that is mediated through a nuclear progestin receptor (Pgr and genomic signaling pathway. To determine whether Pgr plays a role in a nongenomic signaling mechanism during FOM, we knocked out Pgr in zebrafish using transcription activator-like effector nucleases (TALENs and studied the oocyte maturation phenotypes of Pgr knockouts (Pgr-KOs. Three TALENs-induced mutant lines with different frame shift mutations were generated. Homozygous Pgr-KO female fish were all infertile while no fertility effects were evident in homozygous Pgr-KO males. Oocytes developed and underwent FOM normally in vivo in homozygous Pgr-KO female compared to the wildtype controls, but these mature oocytes were trapped within the follicular cells and failed to ovulate from the ovaries. These oocytes also underwent normal germinal vesicle breakdown (GVBD and FOM in vitro, but failed to ovulate even after treatment with human chronic gonadotropin (HCG or progestin (17alpha,20beta-dihydroxyprogesterone or DHP, which typically induce FOM and ovulation in wildtype oocytes. The results indicate that anovulation and infertility in homozygous Pgr-KO female fish was, at least in part, due to a lack of functional Pgr-mediated genomic progestin signaling in the follicular cells adjacent to the oocytes. Our study of Pgr-KO supports previous results that demonstrate a role for Pgr in steroid-dependent genomic signaling pathways leading to ovulation, and the first convincing evidence that Pgr is not essential for initiating nongenomic progestin signaling and triggering meiosis resumption.

  15. DMPD: Toll-like receptors regulation of viral infection and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280610 Toll-like receptors regulation of viral infection and disease. Thompson JM...how Toll-like receptors regulation of viral infection and disease. PubmedID 18280610 Title Toll-like recepto...rs regulation of viral infection and disease. Authors Thompson JM, Iwasaki A. Pub

  16. Adrenal medullary regulation of rat renal cortical adrenergic receptors

    International Nuclear Information System (INIS)

    Sundaresan, P.R.; Guarnaccia, M.M.; Izzo, J.L. Jr.

    1987-01-01

    The role of the adrenal medulla in the regulation of renal cortical adrenergic receptors was investigated in renal cortical particular fractions from control rats and rats 6 wk after adrenal demedullation. The specific binding of [ 3 H]prazosin, [ 3 H]rauwolscine, and [ 125 I]iodocyanopindolol were used to quantitate α 1 -, α 2 -, and β-adrenergic receptors, respectively. Adrenal demedullation increased the concentration of all three groups of renal adrenergic receptors; maximal number of binding sites (B max , per milligram membrane protein) for α 1 -, and α 2 -, and β-adrenergic receptors were increased by 22, 18.5, and 25%, respectively. No differences were found in the equilibrium dissociation constants (K D ) for any of the radioligands. Plasma corticosterone and plasma and renal norepinephrine levels were unchanged, whereas plasma epinephrine was decreased 72% by adrenal demedullation, renal cortical epinephrine was not detectable in control or demedullated animals. The results suggest that, in the physiological state, the adrenal medulla modulates the number of renal cortical adrenergic receptors, presumably through the actions of a circulating factor such as epinephrine

  17. SRC-1 regulates blood pressure and aortic stiffness in female mice

    Science.gov (United States)

    Framingham Heart Study suggests that dysfunction of steroid receptor coactivator-1 may be involved in the development of hypertension. However, there is no functional evidence linking steroid receptor coactivator-1 to the regulation of blood pressure. We used immunohistochemistry to map the expressi...

  18. Oral contraceptives and neuroactive steroids.

    Science.gov (United States)

    Rapkin, Andrea J; Biggio, Giovanni; Concas, Alessandra

    2006-08-01

    A deregulation in the peripheral and brain concentrations of neuroactive steroids has been found in certain pathological conditions characterized by emotional or affective disturbances, including major depression and anxiety disorders. In this article we summarize data pertaining to the modulatory effects of oral contraceptive treatment on neuroactive steroids in women and rats. Given that the neuroactive steroids concentrations are reduced by oral contraceptives, together with the evidence that a subset of women taking oral contraceptives experience negative mood symptoms, we propose the use of this pharmacological treatment as a putative model to study the role of neuroactive steroids in the etiopathology of mood disorders. Moreover, since neuroactive steroids are potent modulators of GABA(A) receptor function and plasticity, the treatment with oral contraceptives might also represent a useful experimental model to further investigate the physiological role of these steroids in the modulation of GABAergic transmission.

  19. Sex steroids and neurogenesis.

    Science.gov (United States)

    Heberden, Christine

    2017-10-01

    The brain has long been known as a dimorphic organ and as a target of sex steroids. It is also a site for their synthesis. Sex steroids in numerous ways can modify cerebral physiology, and along with many processes adult neurogenesis is also modulated by sex steroids. This review will focus on the effects of the main steroids, estrogens, androgens and progestogens, and unveil some aspects of their partly disclosed mechanisms of actions. Gonadal steroids act on different steps of neurogenesis: cell proliferation seems to be increased by estrogens only, while androgens and progestogens favor neuronal renewal by increasing cell survival; differentiation is a common target. Aging is characterized by a cognitive deficiency, paralleled by a decrease in the rate of neuronal renewal and in the levels of circulating gonadal hormones. Therefore, the effects of gonadal hormones on the aging brain are important to consider. The review will also be expanded to related molecules which are agonists to the nuclear receptors. Sex steroids can modify adult neuronal renewal and the extensive knowledge of their actions on neurogenesis is essential, as it can be a leading pathway to therapeutic perspectives. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Steroid modulation of the chloride ionophore in rat brain: structure-activity requirements, regional dependence and mechanism of action

    Energy Technology Data Exchange (ETDEWEB)

    Gee, K.W.; Bolger, M.B.; Brinton, R.E.; Coirini, H.; McEwen, B.S.

    1988-08-01

    Further in vitro studies of steroids active at the gamma-aminobutyric acidA (GABAA) receptor regulated Cl- channel labeled by (35S)-t-butylbicyclophosphorothionate ((35S)TBPS) reveal additional structural requirements necessary for activity. Evaluation of selected steroids for activity against TBPS-induced convulsions show similar requirements for activity. Interestingly, steroids (e.g., 5 alpha-pregnan-3 alpha, 20 alpha-diol) were identified that have high potency but limited efficacy as modulators of (35S)TBPS binding. These characteristics are reminiscent of the clinically useful benzodiazepines (BZs) such as clonazepam. However, interactions between the prototypical anesthetic-barbiturate, sodium pentobarbital, and steroids active at the Cl- channel suggest that they do not share a common site of action as allosteric modulators of (35S)TBPS and BZ receptor binding. The most potent steroid evaluated, 5 alpha-pregnan-3 alpha-ol-20-one, modulates (35S)TBPS binding at low concentrations (IC50 approximately 17 nM) in a regionally dependent manner. All (35S)TBPS binding sites appear to be functionally coupled to a steroid modulatory site. Because several of the active steroids are metabolites of progesterone, their ability to inhibit the binding of (3H)promegestrone to the cytosolic progestin receptor in rat uterus was evaluated. Those steroids showing potent activity at the GABAA receptor-Cl- ionophore were inactive at the intracellular progestin receptor. Such specificity coupled with their high potency provide additional support for the hypothesis that some of these steroids may be involved in the homeostatic regulation of brain excitability via the GABAA-BZ receptor complex.

  1. Steroid osteopathy

    Energy Technology Data Exchange (ETDEWEB)

    Conway, J.J.; Weiss, S.C.

    1984-01-01

    Patients receiving steroids or having disease processes which increase natural steroid production often demonstrate ''the classic x-ray changes'' of avascular necrosis of bone. Bone scintigraphy in these patients most frequently demonstrates an increased radionuclide localization. The literature suggests that the increased activity is related to healing of the avascular process. In a recent study of Legg-Calve-Perthes Disease (LCPD), 37 of the children had multiple studies and increased activity within the epiphysis during revascularization was extremely rare. Not only are the scintigraphic findings in steroid osteopathy dissimilar to that in healing LCPD, but the time interval for healing is much to short for that of a vascular necrosis and no patients demonstrated an avascular phase on bone scintigraphy. Of 15 children with renal transplants on steroid therapy, 9 demonstrated x-ray and clinical findings of osteopathy. In 8 of 9 instances, bone scintigraphy showed increased localization of radionuclide in the affected bone. Improvement or a return to normal occurred in those patients in whom steroids were discontinued. The following is a proposed mechanism for steroid osteopathy. Steroids affect the osteoblastic and osteoclastic activity of bone and weaken its internal structure. Ordinary stress produces microtrabecular fractures. Fractures characteristically stimulate reactive hyperemia and increase bone metabolism. The result is increased bone radiopharmaceutical localization. The importance of recognizing this concept is that steroid osteopathy is preventable by reducing the administered steroid dose. As opposed to avascular necrosis, bone changes are reversible.

  2. Steroid osteopathy

    International Nuclear Information System (INIS)

    Conway, J.J.; Weiss, S.C.

    1984-01-01

    Patients receiving steroids or having disease processes which increase natural steroid production often demonstrate ''the classic x-ray changes'' of avascular necrosis of bone. Bone scintigraphy in these patients most frequently demonstrates an increased radionuclide localization. The literature suggests that the increased activity is related to healing of the avascular process. In a recent study of Legg-Calve-Perthes Disease (LCPD), 37 of the children had multiple studies and increased activity within the epiphysis during revascularization was extremely rare. Not only are the scintigraphic findings in steroid osteopathy dissimilar to that in healing LCPD, but the time interval for healing is much to short for that of a vascular necrosis and no patients demonstrated an avascular phase on bone scintigraphy. Of 15 children with renal transplants on steroid therapy, 9 demonstrated x-ray and clinical findings of osteopathy. In 8 of 9 instances, bone scintigraphy showed increased localization of radionuclide in the affected bone. Improvement or a return to normal occurred in those patients in whom steroids were discontinued. The following is a proposed mechanism for steroid osteopathy. Steroids affect the osteoblastic and osteoclastic activity of bone and weaken its internal structure. Ordinary stress produces microtrabecular fractures. Fractures characteristically stimulate reactive hyperemia and increase bone metabolism. The result is increased bone radiopharmaceutical localization. The importance of recognizing this concept is that steroid osteopathy is preventable by reducing the administered steroid dose. As opposed to avascular necrosis, bone changes are reversible

  3. Ovarian steroids alter dopamine receptor populations in the medial preoptic area of female rats: implications for sexual motivation, desire, and behaviour.

    Science.gov (United States)

    Graham, M Dean; Gardner Gregory, James; Hussain, Dema; Brake, Wayne G; Pfaus, James G

    2015-12-01

    Dopamine (DA) transmission in the medial preoptic area (mPOA) plays a critical role in the control of appetitive sexual behaviour in the female rat. We have shown previously that a DA D1 receptor (D1R)-mediated excitatory state appears to occur in females primed with estradiol benzoate (EB) and progesterone (P), whereas a DA D2 receptor (D2R)-mediated inhibitory state appears to occur in females primed only with EB. The present experiment employed three techniques to better understand what changes occur to DA receptors (DARs) in the mPOA under different hormonal profiles. Ovariectomized females were randomly assigned to one of three steroid treatment groups: EB + P (10 and 500 μg, respectively), EB + Oil, or the control (Oil + Oil), with hormone injections administered at 48 and 4 h prior to euthanizing. First, the number of neurons in the mPOA that contained D1R or D2R was assessed using immunohistochemistry. Second, the mPOA and two control areas (the prelimbic cortex and caudate putamen) were analysed for DAR protein levels using western blot, and DAR functional binding levels using autoradiography. Ovarian steroid hormones affected the two DAR subtypes in opposite ways in the mPOA. All three techniques supported previous behavioural findings that females primed with EB have a lower D1R : D2R ratio, and thus a D2R-mediated system, and females primed with EB + P have a higher D1R : D2R ratio, and thus a D1R-mediated system. This provides strong evidence for a DA-driven pathway of female sexual motivation, desire, and behaviour that is modified by different hormone priming regimens. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Identification and Transcriptional Modulation of the Largemouth Bass, Micropterus salmoides, Vitellogenin Receptor During Oocyte Development by Insulin and Sex Steroids1

    Science.gov (United States)

    Dominguez, Gustavo A.; Quattro, Joseph M.; Denslow, Nancy D.; Kroll, Kevin J.; Prucha, Melinda S.; Porak, Wesley F.; Grier, Harry J.; Sabo-Attwood, Tara L.

    2012-01-01

    ABSTRACT Fish vitellogenin synthesized and released from the liver of oviparous animals is taken up into oocytes by the vitellogenin receptor. This is an essential process in providing nutrient yolk to developing embryos to ensure successful reproduction. Here we disclose the full length vtgr cDNA sequence for largemouth bass (LMB) that reveals greater than 90% sequence homology with other fish vtgr sequences. We classify LMB Vtgr as a member of the low density lipoprotein receptor superfamily based on conserved domains and categorize as the short variant that is devoid of the O-glycan segment. Phylogenetic analysis places LMB Vtgr sequence into a well-supported monophyletic group of fish Vtgr. Real-time PCR showed that the greatest levels of LMB vtgr mRNA expression occurred in previtellogenic ovarian tissues. In addition, we reveal the effects of insulin, 17beta-estradiol (E2), and 11-ketotestosterone (11-KT) in modulation of vtgr, esr, and ar mRNAs in previtellogenic oocytes. Insulin increased vtgr expression levels in follicles ex vivo while exposure to E2 or 11-KT did not result in modulation of expression. However, both steroids were able to repress insulin-induced vtgr transcript levels. Coexposure with insulin and E2 or of insulin and 11-KT increased ovarian esr2b and ar mRNA levels, respectively, which suggest a role for these nuclear receptors in insulin-mediated signaling pathways. These data provide the first evidence for the ordered stage-specific expression of LMB vtgr during the normal reproductive process and the hormonal influence of insulin and sex steroids on controlling vtgr transcript levels in ovarian tissues. PMID:22786822

  5. Regulation of neuronal communication by G protein-coupled receptors.

    Science.gov (United States)

    Huang, Yunhong; Thathiah, Amantha

    2015-06-22

    Neuronal communication plays an essential role in the propagation of information in the brain and requires a precisely orchestrated connectivity between neurons. Synaptic transmission is the mechanism through which neurons communicate with each other. It is a strictly regulated process which involves membrane depolarization, the cellular exocytosis machinery, neurotransmitter release from synaptic vesicles into the synaptic cleft, and the interaction between ion channels, G protein-coupled receptors (GPCRs), and downstream effector molecules. The focus of this review is to explore the role of GPCRs and G protein-signaling in neurotransmission, to highlight the function of GPCRs, which are localized in both presynaptic and postsynaptic membrane terminals, in regulation of intrasynaptic and intersynaptic communication, and to discuss the involvement of astrocytic GPCRs in the regulation of neuronal communication. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  6. TAM receptors regulate multiple features of microglial physiology.

    Science.gov (United States)

    Fourgeaud, Lawrence; Través, Paqui G; Tufail, Yusuf; Leal-Bailey, Humberto; Lew, Erin D; Burrola, Patrick G; Callaway, Perri; Zagórska, Anna; Rothlin, Carla V; Nimmerjahn, Axel; Lemke, Greg

    2016-04-14

    Microglia are damage sensors for the central nervous system (CNS), and the phagocytes responsible for routine non-inflammatory clearance of dead brain cells. Here we show that the TAM receptor tyrosine kinases Mer and Axl regulate these microglial functions. We find that adult mice deficient in microglial Mer and Axl exhibit a marked accumulation of apoptotic cells specifically in neurogenic regions of the CNS, and that microglial phagocytosis of the apoptotic cells generated during adult neurogenesis is normally driven by both TAM receptor ligands Gas6 and protein S. Using live two-photon imaging, we demonstrate that the microglial response to brain damage is also TAM-regulated, as TAM-deficient microglia display reduced process motility and delayed convergence to sites of injury. Finally, we show that microglial expression of Axl is prominently upregulated in the inflammatory environment that develops in a mouse model of Parkinson's disease. Together, these results establish TAM receptors as both controllers of microglial physiology and potential targets for therapeutic intervention in CNS disease.

  7. Hypochlorite Oxidation of Select Androgenic Steroids

    Science.gov (United States)

    Steroid hormones are vital for regulation of various biological functions including sexual development. Elevated concentrations of natural and synthetic androgenic steroids have been shown to adversely affect normal development in indigenous aqueous species. Androgens and their s...

  8. Genetic variations in the androgen receptor are associated with steroid concentrations and anthropometrics but not with muscle mass in healthy young men.

    Directory of Open Access Journals (Sweden)

    Hélène De Naeyer

    Full Text Available OBJECTIVE: The relationship between serum testosterone (T levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings. DESIGN: 677 men (25-45 years were recruited in a cross-sectional, population-based sibling pair study. METHODS: Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs, sex steroid levels (by LC-MS/MS, body composition (by DXA, muscle cross-sectional area (CSA (by pQCT, muscle force (isokinetic peak torque, grip strength and anthropometrics were studied using linear mixed-effect modelling. RESULTS: Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT and free T (FT levels were positively related to muscle CSA, whereas estradiol (E2 and free E2 (FE2 concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E2 and FE2 concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats. CONCLUSIONS: Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR

  9. Nuclear receptor 5A (NR5A) family regulates 5-aminolevulinic acid synthase 1 (ALAS1) gene expression in steroidogenic cells.

    Science.gov (United States)

    Ju, Yunfeng; Mizutani, Tetsuya; Imamichi, Yoshitaka; Yazawa, Takashi; Matsumura, Takehiro; Kawabe, Shinya; Kanno, Masafumi; Umezawa, Akihiro; Kangawa, Kenji; Miyamoto, Kaoru

    2012-11-01

    5-Aminolevulinic acid synthase 1 (ALAS1) is a rate-limiting enzyme for heme biosynthesis in mammals. Heme is essential for the catalytic activities of P450 enzymes including steroid metabolic enzymes. Nuclear receptor 5A (NR5A) family proteins, steroidogenic factor-1 (SF-1), and liver receptor homolog-1 (LRH-1) play pivotal roles in regulation of steroidogenic enzymes. Recently, we showed that expression of SF-1/LRH-1 induces differentiation of mesenchymal stem cells into steroidogenic cells. In this study, genome-wide analysis revealed that ALAS1 was a novel SF-1-target gene in differentiated mesenchymal stem cells. Chromatin immunoprecipitation and reporter assays revealed that SF-1/LRH-1 up-regulated ALAS1 gene transcription in steroidogenic cells via binding to a 3.5-kb upstream region of ALAS1. The ALAS1 gene was up-regulated by overexpression of SF-1/LRH-1 in steroidogenic cells and down-regulated by knockdown of SF-1 in these cells. Peroxisome proliferator-activated receptor-γ coactivator-1α, a coactivator of nuclear receptors, also strongly coactivated expression of NR5A-target genes. Reporter analysis revealed that peroxisome proliferator-activated receptor-γ coactivator-1α strongly augmented ALAS1 gene transcription caused by SF-1 binding to the 3.5-kb upstream region. Finally knockdown of ALAS1 resulted in reduced progesterone production by steroidogenic cells. These results indicate that ALAS1 is a novel NR5A-target gene and participates in steroid hormone production.

  10. Ligand Receptor-Mediated Regulation of Growth in Plants.

    Science.gov (United States)

    Haruta, Miyoshi; Sussman, Michael R

    2017-01-01

    Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

  11. Glucocorticoid Receptor Interacting Co-regulators: Putative Candidates for Future Drug Targeting Therapy.

    Science.gov (United States)

    Di Silvestre, Alessia; Lucafo, Marianna; De Iudicibus, Sara; Ventura, Alessandro; Martelossi, Stefano; Stocco, Gabriele; Decorti, Giuliana

    2017-01-01

    Glucocorticoids (GCs) are largely used in different inflammatory, autoimmune and proliferative diseases. To date their mechanism of action is not completely clear and more studies are necessary, in particular to explain the great interindividual variability in clinical response. In this panorama the glucocorticoid receptor (GR) has an important role: in fact it regulates the pharmacological response thanks to the capability to interact with different molecules (DNA, RNA, ncRNA and proteins) that are known to influence its activity. In this review our aim is to highlight the knowledge about the role of protein-protein, RNAprotein interactions and epigenetic modifications on the GR and the consequent response to GCs. The characteristics of these interactions with the GR and their effects on the pharmacological activity of GCs will be examined. This information could contribute to the prediction of individual sensitivity to steroids through the identification of new markers of GC resistance. In addition this knowledge may be used in developing new strategies for targeted therapy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. DMPD: Receptor tyrosine kinases and the regulation of macrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14726496 Receptor tyrosine kinases and the regulation of macrophage activation. Cor...osine kinases and the regulation of macrophage activation. PubmedID 14726496 Title Receptor tyrosine...rell PH, Morrison AC, Lutz MA. J Leukoc Biol. 2004 May;75(5):731-7. Epub 2004 Jan 14. (.png) (.svg) (.html) (.csml) Show Receptor tyr

  13. Serotonin 2c receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis

    Science.gov (United States)

    Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor a...

  14. Oral Steroids (Steroid Pills and Syrups)

    Science.gov (United States)

    ... steroid bursts can cause a number of side effects. Steroid side effects usually occur after long-term use ... how the dosage of steroids is determined; side effects of inhaled steroids, and some recommendations to decrease or prevent side ...

  15. Modeling of non-steroidal anti-inflammatory drug effect within signaling pathways and miRNA-regulation pathways.

    Directory of Open Access Journals (Sweden)

    Jian Li

    Full Text Available To date, it is widely recognized that Non-Steroidal Anti-Inflammatory Drugs (NSAIDs can exert considerable anti-tumor effects regarding many types of cancers. The prolonged use of NSAIDs is highly associated with diverse side effects. Therefore, tailoring down the NSAID application onto individual patients has become a necessary and relevant step towards personalized medicine. This study conducts the systemsbiological approach to construct a molecular model (NSAID model containing a cyclooxygenase (COX-pathway and its related signaling pathways. Four cancer hallmarks are integrated into the model to reflect different developmental aspects of tumorigenesis. In addition, a Flux-Comparative-Analysis (FCA based on Petri net is developed to transfer the dynamic properties (including drug responsiveness of individual cellular system into the model. The gene expression profiles of different tumor-types with available drug-response information are applied to validate the predictive ability of the NSAID model. Moreover, two therapeutic developmental strategies, synthetic lethality and microRNA (miRNA biomarker discovery, are investigated based on the COX-pathway. In conclusion, the result of this study demonstrates that the NSAID model involving gene expression, gene regulation, signal transduction, protein interaction and other cellular processes, is able to predict the individual cellular responses for different therapeutic interventions (such as NS-398 and COX-2 specific siRNA inhibition. This strongly indicates that this type of model is able to reflect the physiological, developmental and pathological processes of an individual. The approach of miRNA biomarker discovery is demonstrated for identifying miRNAs with oncogenic and tumor suppressive functions for individual cell lines of breast-, colon- and lung-tumor. The achieved results are in line with different independent studies that investigated miRNA biomarker related to diagnostics of cancer

  16. Comparative metabolomics reveals endogenous ligands of DAF-12, a nuclear hormone receptor regulating C. elegans development and lifespan

    Science.gov (United States)

    Mahanti, Parag; Bose, Neelanjan; Bethke, Axel; Judkins, Joshua C.; Wollam, Joshua; Dumas, Kathleen J.; Zimmerman, Anna M.; Campbell, Sydney L.; Hu, Patrick J.; Antebi, Adam; Schroeder, Frank C.

    2014-01-01

    SUMMARY Small-molecule ligands of nuclear hormone receptors (NHRs) govern the transcriptional regulation of metazoan development, cell differentiation, and metabolism. However, the physiological ligands of many NHRs remain poorly characterized primarily due to lack of robust analytical techniques. Using comparative metabolomics, we identified endogenous steroids that act as ligands of the C. elegans NHR, DAF-12, a vitamin-D and liver-X receptor homolog regulating larval development, fat metabolism, and lifespan. The identified molecules feature unexpected chemical modifications and include only one of two DAF-12 ligands reported earlier, necessitating a revision of previously proposed ligand biosynthetic pathways. We further show that ligand profiles are regulated by a complex enzymatic network including the Rieske oxygenase DAF-36, the short-chain dehydrogenase DHS-16, and the hydroxysteroid dehydrogenase, HSD-1. Our results demonstrate the advantages of comparative metabolomics over traditional candidate-based approaches and provide a blueprint for the identification of ligands for other C. elegans and mammalian NHRs. PMID:24411940

  17. Autocrine regulation of ecdysone synthesis by β3-octopamine receptor in the prothoracic gland is essential for Drosophila metamorphosis.

    Science.gov (United States)

    Ohhara, Yuya; Shimada-Niwa, Yuko; Niwa, Ryusuke; Kayashima, Yasunari; Hayashi, Yoshiki; Akagi, Kazutaka; Ueda, Hitoshi; Yamakawa-Kobayashi, Kimiko; Kobayashi, Satoru

    2015-02-03

    In Drosophila, pulsed production of the steroid hormone ecdysone plays a pivotal role in developmental transitions such as metamorphosis. Ecdysone production is regulated in the prothoracic gland (PG) by prothoracicotropic hormone (PTTH) and insulin-like peptides (Ilps). Here, we show that monoaminergic autocrine regulation of ecdysone biosynthesis in the PG is essential for metamorphosis. PG-specific knockdown of a monoamine G protein-coupled receptor, β3-octopamine receptor (Octβ3R), resulted in arrested metamorphosis due to lack of ecdysone. Knockdown of tyramine biosynthesis genes expressed in the PG caused similar defects in ecdysone production and metamorphosis. Moreover, PTTH and Ilps signaling were impaired by Octβ3R knockdown in the PG, and activation of these signaling pathways rescued the defect in metamorphosis. Thus, monoaminergic autocrine signaling in the PG regulates ecdysone biogenesis in a coordinated fashion on activation by PTTH and Ilps. We propose that monoaminergic autocrine signaling acts downstream of a body size checkpoint that allows metamorphosis to occur when nutrients are sufficiently abundant.

  18. Regulation of Liver Energy Balance by the Nuclear Receptors Farnesoid X Receptor and Peroxisome Proliferator Activated Receptor α.

    Science.gov (United States)

    Kim, Kang Ho; Moore, David D

    2017-01-01

    The liver undergoes major changes in substrate utilization and metabolic output over the daily feeding and fasting cycle. These changes occur acutely in response to hormones such as insulin and glucagon, with rapid changes in signaling pathways mediated by protein phosphorylation and other post-translational modifications. They are also reflected in chronic alterations in gene expression in response to nutrient-sensitive transcription factors. Among these, the nuclear receptors farnesoid X receptor (FXR) and peroxisome proliferator activated receptor α (PPARα) provide an intriguing, coordinated response to maintain energy balance in the liver. FXR is activated in the fed state by bile acids returning to the liver, while PPARα is activated in the fasted state in response to the free fatty acids produced by adipocyte lipolysis or possibly other signals. Key Messages: Previous studies indicate that FXR and PPARα have opposing effects on each other's primary targets in key metabolic pathways including gluconeogenesis. Our more recent work shows that these 2 nuclear receptors coordinately regulate autophagy: FXR suppresses this pathway of nutrient and energy recovery, while PPARα activates it. Another recent study indicates that FXR activates the complement and coagulation pathway, while earlier studies identify this as a negative target of PPARα. Since secretion is a very energy- and nutrient-intensive process for hepatocytes, it is possible that FXR licenses it in the nutrient-rich fed state, while PPARα represses it to spare resources in the fasted state. Energy balance is a potential connection linking FXR and PPARα regulation of autophagy and secretion, 2 seemingly unrelated aspects of hepatocyte function. FXR and PPARα act coordinately to promote energy balance and homeostasis in the liver by regulating autophagy and potentially protein secretion. It is quite likely that their impact extends to additional pathways relevant to hepatic energy balance, and

  19. Synaptic activity regulates AMPA receptor trafficking through different recycling pathways

    Science.gov (United States)

    Zheng, Ning; Jeyifous, Okunola; Munro, Charlotte; Montgomery, Johanna M; Green, William N

    2015-01-01

    Changes in glutamatergic synaptic strength in brain are dependent on AMPA-type glutamate receptor (AMPAR) recycling, which is assumed to occur through a single local pathway. In this study, we present evidence that AMPAR recycling occurs through different pathways regulated by synaptic activity. Without synaptic stimulation, most AMPARs recycled in dynamin-independent endosomes containing the GTPase, Arf6. Few AMPARs recycled in dynamin-dependent endosomes labeled by transferrin receptors (TfRs). AMPAR recycling was blocked by alterations in the GTPase, TC10, which co-localized with Arf6 endosomes. TC10 mutants that reduced AMPAR recycling had no effect on increased AMPAR levels with long-term potentiation (LTP) and little effect on decreased AMPAR levels with long-term depression. However, internalized AMPAR levels in TfR-containing recycling endosomes increased after LTP, indicating increased AMPAR recycling through the dynamin-dependent pathway with synaptic plasticity. LTP-induced AMPAR endocytosis is inconsistent with local recycling as a source of increased surface receptors, suggesting AMPARs are trafficked from other sites. DOI: http://dx.doi.org/10.7554/eLife.06878.001 PMID:25970033

  20. Sex steroid-related candidate genes in psychiatric disorders.

    Science.gov (United States)

    Westberg, Lars; Eriksson, Elias

    2008-07-01

    Sex steroids readily pass the blood-brain barrier, and receptors for them are abundant in brain areas important for the regulation of emotions, cognition and behaviour. Animal experiments have revealed both important early effects of these hormones on brain development and their ongoing influence on brain morphology and neurotransmission in the adult organism. The important effects of sex steroids on human behaviour are illustrated by, for example, the effect of reduced levels of these hormones on sexual drive and conditions such as premenstrual dysphoric disorder, perimenopausal dysphoria, postpartum depression, postpartum psychosis, dysphoria induced by oral contraceptives or hormonal replacement therapy and anabolic steroid-induced aggression. The fact that men and women (as groups) differ with respect to the prevalence of several psychiatric disorders, certain aspects of cognitive function and certain personality traits may possibly also reflect an influence of sex steroids on human behaviour. The heritability of most behavioural traits, including personality, cognitive abilities and susceptibility to psychiatric illness, is considerable, but as yet, only few genes of definite importance in this context have been identified. Given the important role of sex steroids for brain function, it is unfortunate that relatively few studies so far have addressed the possible influence of sex steroid-related genes on interindividual differences with respect to personality, cognition and susceptibility to psychiatric disorders. To facilitate further research in this area, this review provides information on several such genes and summarizes what is currently known with respect to their possible influence on brain function.

  1. Nogo receptor 1 regulates formation of lasting memories

    Science.gov (United States)

    Karlén, Alexandra; Karlsson, Tobias E.; Mattsson, Anna; Lundströmer, Karin; Codeluppi, Simone; Pham, Therese M.; Bäckman, Cristina M.; Ögren, Sven Ove; Åberg, Elin; Hoffman, Alexander F.; Sherling, Michael A.; Lupica, Carl R.; Hoffer, Barry J.; Spenger, Christian; Josephson, Anna; Brené, Stefan; Olson, Lars

    2009-01-01

    Formation of lasting memories is believed to rely on structural alterations at the synaptic level. We had found that increased neuronal activity down-regulates Nogo receptor-1 (NgR1) in brain regions linked to memory formation and storage, and postulated this to be required for formation of lasting memories. We now show that mice with inducible overexpression of NgR1 in forebrain neurons have normal long-term potentiation and normal 24-h memory, but severely impaired month-long memory in both passive avoidance and swim maze tests. Blocking transgene expression normalizes these memory impairments. Nogo, Lingo-1, Troy, endogenous NgR1, and BDNF mRNA expression levels were not altered by transgene expression, suggesting that the impaired ability to form lasting memories is directly coupled to inability to down-regulate NgR1. Regulation of NgR1 may therefore serve as a key regulator of memory consolidation. Understanding the molecular underpinnings of synaptic rearrangements that carry lasting memories may facilitate development of treatments for memory dysfunction. PMID:19915139

  2. The role of steroids in follicular growth

    Directory of Open Access Journals (Sweden)

    Drummond Ann E

    2006-04-01

    Full Text Available Abstract The steroidogenic pathway within the ovary gives rise to progestins, androgens and oestrogens, all of which act via specific nuclear receptors to regulate reproductive function and maintain fertility. The role of progestins in follicular growth and development is limited, its action confined largely to ovulation, although direct effects on granulosa cell function have been reported. Consistent with these findings, progesterone receptor knockout mice are infertile because they cannot ovulate. Androgens have been shown to promote early follicular growth, but also to impede follicular development by stimulating atresia and apoptosis. The inability of androgens to transduce a signal in mice lacking androgen receptors culminates in reduced fertility. Oestrogens are known to exert effects on granulosa cell growth and differentiation in association with gonadotrophins. Studies with oestrogen receptor knockouts and oestrogen depleted mice have shown us that oestrogen is essential for folliculogenesis beyond the antral stage and is necessary to maintain the female phenotype of ovarian somatic cells. In summary, the action of steroids within the ovary is based on the developmental status of the follicle. In the absence of any single sex steroid, ovarian function and subsequently fertility, are compromised.

  3. Cloning and initial characterization of nuclear and membrane progesterone receptors in the Fathead Minnow, Pimephales promelas

    Science.gov (United States)

    Both native progestagens and synthetic progestins have important effects on reproduction that are mediated through progesterone receptors (PRs). They regulate gamete maturation and can serve as precursors for other steroid hormones in vertebrates and act as reproductive pheromone...

  4. RAGE, receptor of advanced glycation endoproducts, negatively regulates chondrocytes differentiation.

    Directory of Open Access Journals (Sweden)

    Tatsuya Kosaka

    Full Text Available RAGE, receptor for advanced glycation endoproducts (AGE, has been characterized as an activator of osteoclastgenesis. However, whether RAGE directly regulates chondrocyte proliferation and differentiation is unclear. Here, we show that RAGE has an inhibitory role in chondrocyte differentiation. RAGE expression was observed in chondrocytes from the prehypertrophic to hypertrophic regions. In cultured cells, overexpression of RAGE or dominant-negative-RAGE (DN-RAGE demonstrated that RAGE inhibited cartilaginous matrix production, while DN-RAGE promoted production. Additionally, RAGE regulated Ihh and Col10a1 negatively but upregulated PTHrP receptor. Ihh promoter analysis and real-time PCR analysis suggested that downregulation of Cdxs was the key for RAGE-induced inhibition of chondrocyte differentiation. Overexpression of the NF-κB inhibitor I-κB-SR inhibited RAGE-induced NF-κB activation, but did not influence inhibition of cartilaginous matrix production by RAGE. The inhibitory action of RAGE was restored by the Rho family GTPases inhibitor Toxin B. Furthermore, inhibitory action on Ihh, Col10a1 and Cdxs was reproduced by constitutively active forms, L63RhoA, L61Rac, and L61Cdc42, but not by I-κB-SR. Cdx1 induced Ihh and Col10a1 expressions and directly interacted with Ihh promoter. Retinoic acid (RA partially rescued the inhibitory action of RAGE. These data combined suggests that RAGE negatively regulates chondrocyte differentiation at the prehypertrophic stage by modulating NF-κB-independent and Rho family GTPases-dependent mechanisms.

  5. Identification of Human P2X1 Receptor-interacting Proteins Reveals a Role of the Cytoskeleton in Receptor Regulation*

    Science.gov (United States)

    Lalo, Ulyana; Roberts, Jonathan A.; Evans, Richard J.

    2011-01-01

    P2X1 receptors are ATP-gated ion channels expressed by smooth muscle and blood cells. Carboxyl-terminally His-FLAG-tagged human P2X1 receptors were stably expressed in HEK293 cells and co-purified with cytoskeletal proteins including actin. Disruption of the actin cytoskeleton with cytochalasin D inhibited P2X1 receptor currents with no effect on the time course of the response or surface expression of the receptor. Stabilization of the cytoskeleton with jasplakinolide had no effect on P2X1 receptor currents but decreased receptor mobility. P2X2 receptor currents were unaffected by cytochalasin, and P2X1/2 receptor chimeras were used to identify the molecular basis of actin sensitivity. These studies showed that the intracellular amino terminus accounts for the inhibitory effects of cytoskeletal disruption similar to that shown for lipid raft/cholesterol sensitivity. Stabilization of the cytoskeleton with jasplakinolide abolished the inhibitory effects of cholesterol depletion on P2X1 receptor currents, suggesting that lipid rafts may regulate the receptor through stabilization of the cytoskeleton. These studies show that the cytoskeleton plays an important role in P2X1 receptor regulation. PMID:21757694

  6. Therapeutic targeting of angiotensin II receptor type 1 to regulate androgen receptor in prostate cancer.

    Science.gov (United States)

    Takahashi, Satoru; Uemura, Hiroji; Seeni, Azman; Tang, Mingxi; Komiya, Masami; Long, Ne; Ishiguro, Hitoshi; Kubota, Yoshinobu; Shirai, Tomoyuki

    2012-10-01

    With the limited strategies for curative treatment of castration-resistant prostate cancer (CRPC), public interest has focused on the potential prevention of prostate cancer. Recent studies have demonstrated that an angiotensin II receptor blocker (ARB) has the potential to decrease serum prostate-specific antigen (PSA) level and improve performance status in CRPC patients. These facts prompted us to investigate the direct effects of ARBs on prostate cancer growth and progression. Transgenic rat for adenocarcinoma of prostate (TRAP) model established in our laboratory was used. TRAP rats of 3 weeks of age received ARB (telmisartan or candesartan) at the concentration of 2 or 10 mg/kg/day in drinking water for 12 weeks. In vitro analyses for cell growth, ubiquitylation or reporter gene assay were performed using LNCaP cells. We found that both telmisartan and candesartan attenuated prostate carcinogenesis in TRAP rats by augmentation of apoptosis resulting from activation of caspases, inactivation of p38 MAPK and down-regulation of the androgen receptor (AR). Further, microarray analysis demonstrated up-regulation of estrogen receptor β (ERβ) by ARB treatment. In both parental and androgen-independent LNCaP cells, ARB inhibited both cell growth and AR-mediated transcriptional activity. ARB also exerted a mild additional effect on AR-mediated transcriptional activation by the ERβ up-regulation. An intervention study revealed that PSA progression was prolonged in prostate cancer patients given an ARB compared with placebo control. These data provide a new concept that ARBs are promising potential chemopreventive and chemotherapeutic agents for prostate cancer. Copyright © 2012 Wiley Periodicals, Inc.

  7. Steroids facing emotions

    NARCIS (Netherlands)

    Putman, P.L.J.

    2006-01-01

    The studies reported in this thesis have been performed to gain a better understanding about motivational mediators of selective attention and memory for emotionally relevant stimuli, and about the roles that some steroid hormones play in regulation of human motivation and emotion. The stimuli used

  8. Investigating the Interactive Effects of Sex Steroid Hormones and Brain-Derived Neurotrophic Factor during Adolescence on Hippocampal NMDA Receptor Expression

    Directory of Open Access Journals (Sweden)

    Cushla R. McCarthny

    2018-01-01

    Full Text Available Sex steroid hormones have neuroprotective properties which may be mediated by brain-derived neurotrophic factor (BDNF. This study sought to determine the interactive effects of preadolescent hormone manipulation and BDNF heterozygosity (+/− on hippocampal NMDA-R expression. Wild-type and BDNF+/− mice were gonadectomised, and females received either 17β-estradiol or progesterone treatment, while males received either testosterone or dihydrotestosterone (DHT treatment. Dorsal (DHP and ventral hippocampus (VHP were dissected, and protein expression of GluN1, GluN2A, GluN2B, and PSD-95 was assessed by Western blot analysis. Significant genotype × OVX interactions were found for GluN1 and GluN2 expression within the DHP of female mice, suggesting modulation of select NMDA-R levels by female sex hormones is mediated by BDNF. Furthermore, within the DHP BDNF+/− mice show a hypersensitive response to hormone treatment on GluN2 expression which may result from upstream alterations in TrkB phosphorylation. In contrast to the DHP, the VHP showed no effects of hormone manipulation but significant effects of genotype on NMDA-R expression. Castration had no effect on NMDA-R expression; however, androgen treatment had selective effects on GluN2B. These data show case distinct, interactive roles for sex steroid hormones and BDNF in the regulation of NMDA-R expression that are dependent on dorsal versus ventral hippocampal region.

  9. Regulation of behaviour by the nuclear receptor TLX.

    Science.gov (United States)

    O'Leary, J D; O'Leary, O F; Cryan, J F; Nolan, Y M

    2018-03-01

    The orphan nuclear receptor Tlx (Nr2e1) is a key regulator of both embryonic and adult hippocampal neurogenesis. Several different mouse models have been developed which target Tlx in vivo including spontaneous deletion models (from birth) and targeted and conditional knockouts. Although some conflicting findings have been reported, for the most part studies have demonstrated that Tlx is important in regulating processes that underlie neurogenesis, spatial learning, anxiety-like behaviour and interestingly, aggression. More recent data have demonstrated that disrupting Tlx during early life induces hyperactivity and that Tlx plays a role in emotional regulation. Moreover, there are sex- and age-related differences in some behaviours in Tlx knockout mice during adolescence and adulthood. Here, we discuss the role of Tlx in motor-, cognitive-, aggressive- and anxiety-related behaviours during adolescence and adulthood. We examine current evidence which provides insight into Tlx during neurodevelopment, and offer our thoughts on the function of Tlx in brain and behaviour. We further hypothesize that Tlx is a key target in understanding the emergence of neurobiological disorders during adolescence and early adulthood. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  10. Expression of Androgen Receptor Is Negatively Regulated By p53

    Directory of Open Access Journals (Sweden)

    Fatouma Alimirah

    2007-12-01

    Full Text Available Increased expression of androgen receptor (AR in prostate cancer (PC is associated with transition to androgen independence. Because the progression of PC to advanced stages is often associated with the loss of p53 function, we tested whether the p53 could regulate the expression of AR gene. Here we report that p53 negatively regulates the expression of AR in prostate epithelial cells (PrECs. We found that in LNCaP human prostate cancer cells that express the wild-type p53 and AR and in human normal PrECs, the activation of p53 by genotoxic stress or by inhibition of p53 nuclear export downregulated the expression of AR. Furthermore, forced expression of p53 in LNCaP cells decreased the expression of AR. Conversely, knockdown of p53 expression in LNCaP cells increased the AR expression. Consistent with the negative regulation of AR expression by p53, the p53-null HCT116 cells expressed higher levels of AR compared with the isogenic HCT116 cells that express the wildtype p53. Moreover, we noted that in etoposide treated LNCaP cells p53 bound to the promoter region of the AR gene, which contains a potential p53 DNA-binding consensus sequence, in chromatin immunoprecipitation assays. Together, our observations provide support for the idea that the loss of p53 function in prostate cancer cells contributes to increased expression of AR.

  11. Sex Steroid Hormones Matter for Learning and Memory: Estrogenic Regulation of Hippocampal Function Inmale and Female Rodents

    Science.gov (United States)

    Frick, Karyn M.; Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

    2015-01-01

    Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17ß-estradiol (E[subscript 2]), affect hippocampal morphology, plasticity, and memory in male and female rodents. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory. This review describes…

  12. ent-Steroids: novel tools for studies of signaling pathways.

    Science.gov (United States)

    Covey, Douglas F

    2009-07-01

    Membrane receptors are often modulated by steroids and it is necessary to distinguish the effects of steroids at these receptors from effects occurring at nuclear receptors. Additionally, it may also be mechanistically important to distinguish between direct effects caused by binding of steroids to membrane receptors and indirect effects on membrane receptor function caused by steroid perturbation of the membrane containing the receptor. In this regard, ent-steroids, the mirror images of naturally occurring steroids, are novel tools for distinguishing between these various actions of steroids. The review provides a background for understanding the different actions that can be expected of steroids and ent-steroids in biological systems, references for the preparation of ent-steroids, a short discussion about relevant forms of stereoisomerism and the requirements that need to be fulfilled for the interaction between two molecules to be enantioselective. The review then summarizes results of biophysical, biochemical and pharmacological studies published since 1992 in which ent-steroids have been used to investigate the actions of steroids in membranes and/or receptor-mediated signaling pathways.

  13. Prostanoid Receptors Involved in Regulation of the Beating Rate of Neonatal Rat Cardiomyocytes

    Science.gov (United States)

    Mechiche, Hakima; Grassin-Delyle, Stanislas; Robinet, Arnaud; Nazeyrollas, Pierre; Devillier, Philippe

    2012-01-01

    Although prostanoids are known to be involved in regulation of the spontaneous beating rate of cultured neonatal rat cardiomyocytes, the various subtypes of prostanoid receptors have not been investigated in detail. In our experiments, prostaglandin (PG)F2α and prostanoid FP receptor agonists (fluprostenol, latanoprost and cloprostenol) produced a decrease in the beating rate. Two prostanoid IP receptor agonists (iloprost and beraprost) induced first a marked drop in the beating rate and then definitive abrogation of beating. In contrast, the prostanoid DP receptor agonists (PGD2 and BW245C) and TP receptor agonists (U-46619) produced increases in the beating rate. Sulprostone (a prostanoid EP1 and EP3 receptor agonist) induced marked increases in the beating rate, which were suppressed by SC-19220 (a selective prostanoid EP1 antagonist). Butaprost (a selective prostanoid EP2 receptor agonist), misoprostol (a prostanoid EP2 and EP3 receptor agonist), 11-deoxy-PGE1 (a prostanoid EP2, EP3 and EP4 receptor agonist) did not alter the beating rate. Our results strongly suggest that prostanoid EP1 receptors are involved in positive regulation of the beating rate. Prostanoid EP1 receptor expression was confirmed by western blotting with a selective antibody. Hence, neonatal rat cardiomyocytes express both prostanoid IP and FP receptors (which negatively regulate the spontaneous beating rate) and prostanoid TP, DP1 and EP1 receptors (which positively regulate the spontaneous beating rate). PMID:22984630

  14. Elevated glucocorticoid receptor binding in cultured human lymphoblasts following hydroxyurea treatment: lack of effect on steroid responsiveness

    International Nuclear Information System (INIS)

    Littlefield, B.A.; Hoagland, H.C.; Greipp, P.R.

    1986-01-01

    While studying the effects of chemotherapy on glucocorticoid receptor (GR) binding levels in hematological malignancies, we observed a sizable increase in nuclear GR binding of [ 3 H]dexamethasone in peripheral leukocytes from a chronic basophilic leukemia patient following treatment with hydroxyurea plus prednisone, but not after prednisone alone. This apparent clinical effect of hydroxyurea led to an examination of hydroxyurea effects on GR binding and sensitivity in the glucocorticoid-sensitive human lymphoblast cell line GM4672A. GR binding levels in GM4672A cells were measured following a 3-day exposure to 50 microM hydroxyurea, a concentration chosen to have a minimal but measurable effect on cellular growth rates with little or no effect on cellular viability. Under these conditions, nuclear [ 3 H]dexamethasone receptor binding measured by Scatchard analysis using a whole-cell assay was elevated 2.4-fold over control values (P less than 0.05), while cytosolic residual receptor binding (measured at 37 0 C) remained unchanged. Thus, the total cellular content of measurable GR was increased, and this increase was totally accounted for by GR capable of nuclear binding. Hydroxyurea treatment of GM4672A cells had no effect on the affinity of nuclear or cytosolic GR for [ 3 H]dexamethasone. The increase in measurable nuclear-bound receptors occurred in a time-dependent manner over a period of 3 days and was fully reversible within 3 days following removal of hydroxyurea. The increase in receptor binding could not be explained by the slight alterations in cell cycle kinetics which occur at this low level of hydroxyurea. Despite increased receptor binding, cellular glucocorticoid responsiveness was unaltered as assessed by dexamethasone inhibition of cell growth and dexamethasone inhibition of a urokinase-like plasminogen activator

  15. Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

    Science.gov (United States)

    Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

    2005-02-28

    Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

  16. Intracellular actions of steroid hormones and their therapeutic value, including the potential of radiohalosteroids against ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J.A. (Chicago Univ. (United States). Dept. of Obstetrics and Gynecology); Scharl, A. (Koeln Univ., Cologne (Germany). Frauen-Klinik); Kullander, S. (Lund Univ. (Sweden). Womens Hospital Malmoe); Beckmann, M.W. (Johann Wolfgang von Goethe Univ., Frankfurt am Main (Germany). Zentrum fuer Frauenheilkunde und Geburtshilfe)

    1992-01-01

    With recombinant cDNA technology, yeast and cultured animal cells can be made to express mammalian cDNA steroid receptors from cDNA clones that contain deletions and substitutions. Among the leading problems addressed in these models is the characterization of sequences that promote association or interaction with other transcription regulating molecules, including oncogene products. Recently it has been found that heat shock proteins may serve not only to stabilize the receptor proteins but also to precondition the activation imparted by ligand binding. Aberrant receptor proteins can be found in ovarian cancer. Whether aberrant receptor proteins are associated with transformation in general or with a variable clinical response to steroidal or anti-steroidal therapy is not known. Even after chemotherapy, steroid receptors are expressed in the metastases of ovarian cancers seen clinically, and they may have potential use for localization and treatment of receptor-rich cancers. Radioligand pharmaceuticals appropriate for imaging or for site-directed radiocytotoxicity can be sequestered to the nuclei of receptor-rich cancers. Initial clinical imaging and therapy trials with such pharmaceuticals have been approved and begun. In the use of halogenated estrogen radiopharmaceuticals, liver metabolism and enterohepatic recirculation are important considerations. Ascites prolongs retention of radiohalogenated estrogen in the abdominal cavity. Distant metastases have been localized with [[sup 123]I]-estrogen in breast cancer patients in pre-operative procedures. Receptor-mediated cytotoxicity occurs when estrogen receptor radioligand pharmaceuticals that are Auger electron emitters are used in vitro. (au) (119 refs., 3 figs.).

  17. The AMPA receptor-associated protein Shisa7 regulates hippocampal synaptic function and contextual memory

    NARCIS (Netherlands)

    Schmitz, Leanne J M; Klaassen, Remco V; Ruiperez-Alonso, Marta; Zamri, Azra Elia; Stroeder, Jasper; Rao-Ruiz, Priyanka; Lodder, Johannes C; van der Loo, Rolinka J; Mansvelder, Huib D; Smit, August B; Spijker, Sabine; Verhage, Matthijs

    2017-01-01

    Glutamatergic synapses rely on AMPA receptors (AMPARs) for fast synaptic transmission and plasticity. AMPAR auxiliary proteins regulate receptor trafficking, and modulate receptor mobility and its biophysical properties. The AMPAR auxiliary protein Shisa7 (CKAMP59) has been shown to interact with

  18. Functional properties of Virus-Encoded and Virus-Regulated 7TM Receptors

    DEFF Research Database (Denmark)

    Spiess, Katja; Rosenkilde, Mette Marie

    2014-01-01

    During co-evolution with their hosts, viruses have developed several survival strategies that involve exploitation of 7TM receptors. These include virus-encoded 7TM receptors and ligands and viral regulation of endogenous receptors. Many functional properties have been ascribed to virus-exploited...

  19. Nitrophenols isolated from diesel exhaust particles regulate steroidogenic gene expression and steroid synthesis in the human H295R adrenocortical cell line

    International Nuclear Information System (INIS)

    Furuta, Chie; Noda, Shiho; Li Chunmei; Suzuki, Akira K; Taneda, Shinji; Watanabe, Gen; Taya, Kazuyoshi

    2008-01-01

    Studies of nitrophenols isolated from diesel exhaust particles (DEPs), 3-methyl-4-nitrophenol (PNMC) and 4-nitro-3-phenylphenol (PNMPP) have revealed that these chemicals possess estrogenic and anti-androgenic activity in vitro and in vivo and that PNMC accumulate in adrenal glands in vivo. However, the impacts of exposure to these compounds on adrenal endocrine disruption and steroidogenesis have not been investigated. To elucidate the non-receptor mediated effects of PNMC and PNMPP, we investigated the production of the steroid hormones progesterone, cortisol, testosterone, and estradiol-17β and modulation of nine major enzyme genes involved in the synthesis of steroid hormones (CYP11A, CYP11B1, CYP17, CYP19, 17βHSD1, 17βHSD4, CYP21, 3βHSD2, StAR) in human adrenal H295R cells supplied with cAMP. Exposure to 10 -7 to 10 -5 M PNMC and 1 mM 8-Br-cAMP for 48 h decreased testosterone, cortisol, and estradiol-17β levels and increased progesterone secretion. At 10 -5 M, PNMC with 1 mM 8-Br-cAMP significantly stimulated expression of the 17βHSD4 and significantly suppressed expression of 3βHSD2. In comparison, 10 -7 to 2 x 10 -5 M PNMPP with 1 mM 8-Br-cAMP for 48 h decreased concentrations of estradiol-17β, increased progesterone levels, but did not affect testosterone and cortisol secretion due to the significant suppression of CYP17 and the non-significant but obvious suppression of CYP19. Our results clarified steroidogenic enzymes as candidates responsible for the inhibition or stimulation for the production of steroid hormones in the steroidogenic pathway, thus providing the first experimental evidence for multiple mechanisms of disruption of endocrine pathways by these nitrophenols

  20. CaMKII Regulation of Cardiac Ryanodine Receptors and Inositol Triphosphate Receptors

    Directory of Open Access Journals (Sweden)

    Emmanuel eCamors

    2014-05-01

    Full Text Available Ryanodine receptors (RyRs and inositol triphosphate receptors (InsP3Rs are structurally related intracellular calcium release channels that participate in multiple primary or secondary amplified Ca2+ signals, triggering muscle contraction and oscillatory Ca2+ waves, or activating transcription factors. In the heart, RyRs play an indisputable role in the process of excitation-contraction coupling as the main pathway for Ca2+ release from sarcoplasmic reticulum (SR, and a less prominent role in the process of excitation-transcription coupling. Conversely, InsP3Rs are believed to contribute in subtle ways, only, to contraction of the heart, and in more important ways to regulation of transcription factors. Because uncontrolled activity of either RyRs or InsP3Rs may elicit life-threatening arrhythmogenic and/or remodeling Ca2+ signals, regulation of their activity is of paramount importance for normal cardiac function. Due to their structural similarity, many regulatory factors, accessory proteins, and posttranslational processes are equivalent for RyRs and InsP3Rs. Here we discuss regulation of RyRs and InsP3Rs by CaMKII phosphorylation, but touch on other kinases whenever appropriate. CaMKII is emerging as a powerful modulator of RyR and InsP3R activity but interestingly, some of the complexities and controversies surrounding phosphorylation of RyRs also apply to InsP3Rs, and a clear-cut effect of CaMKII on either channel eludes investigators for now. Nevertheless, some effects of CaMKII on global cellular activity, such as SR Ca2+ leak or force-frequency potentiation, appear clear now, and this constrains the limits of the controversies and permits a more tractable approach to elucidate the effects of phosphorylation at the single channel level.

  1. Estrogen-related receptor beta interacts with Oct4 to positively regulate Nanog gene expression

    NARCIS (Netherlands)

    D.L.C. van den Berg (Debbie); W. Zhang (Wensheng); A. Yates (Adam); M.P. Engelen (Erik); K. Takacs (Katalin); K. Bezstarosti (Karel); J.A.A. Demmers (Jeroen); I. Chambers (Ian); R.A. Poor (Raymond)

    2008-01-01

    textabstractEmbryonic stem (ES) cell self-renewal is regulated by transcription factors, including Oct4, Sox2, and Nanog. A number of additional transcriptional regulators of ES cell self-renewal have recently been identified, including the orphan nuclear receptor estrogen-related receptor beta

  2. Sex steroid receptor expression in the oviduct and uterus of sheep with estrus synchronized with progestagen or prostaglandin analogues.

    Science.gov (United States)

    García-Palencia, P; Sánchez, M A; Nieto, A; Vilar, M P; González, M; Veiga-Lopez, A; González-Bulnes, A; Flores, J M

    2007-01-01

    The objective of this study was to investigate differences in the expression of estrogen receptor-alpha (ERalpha), progesterone receptor (PR) and the proliferative indexes (Ki-67), in the uterus and oviduct of sheep with estrus synchronized either by prostaglandin analogues (Group PA, n=27) or by treatment with progestagens (Group P, n=29) on days 4 and 7 (day 0=estrus), when the embryos were collected. Immunohistochemical methods were used to quantify ERalpha, PR and Ki-67 in six superficial and deep compartments in the uterus and oviduct. The expression of ERalpha was significantly (Pprogesterone treated ewes than in the PA Group in the superficial gland (Psheep with synchronization of estrus with progestagens showed a reduction of ERalpha and PR protein expression in most of oviductal and uterine cells.

  3. Effect of pregnancy on endometrial sex steroid receptors and on prostaglandin F2α release after uterine biopsy in heifers

    International Nuclear Information System (INIS)

    Meikle, A.; Garofalo, E.G.; Sahlin, L.; Thatcher, W.W.; Kindahl, H.; Forsberg, M.

    2005-01-01

    The effect of pregnancy on oestrogen receptor (ER) and progesterone receptor (PR) endometrial expression in heifers was studied. Holstein heifers were not inseminated (controls, n = 8) or inseminated (n = 21). Endometrial biopsies were taken at Day 17 h from the uterine horn ipsilateral to the corpus luteum. Hourly samples were taken on the day of the biopsy in 12 animals (controls = 4 and inseminated = 8) to analyze 15-ketodihydro-PGF 2α (PGFM) and progesterone concentrations. Pregnancy determined by ultrasonography diagnosed 6 pregnant cows. The uterine biopsy increased PGFM concentrations, which remained high for 2 to 4 hours, followed by a transient decrease in progesterone concentrations, but the procedure neither provoked luteolysis nor blocked pregnancy. PGFM concentrations were higher in cyclic than in pregnant cows. No differences in PR mRNA expression were observed among groups, but ER mRNA in pregnant heifers tended to be lower than controls, suggesting that this pathway is implicated in maintenance of pregnancy. (author)

  4. Reelin secreted by GABAergic neurons regulates glutamate receptor homeostasis.

    Directory of Open Access Journals (Sweden)

    Cecilia Gonzalez Campo

    Full Text Available BACKGROUND: Reelin is a large secreted protein of the extracellular matrix that has been proposed to participate to the etiology of schizophrenia. During development, reelin is crucial for the correct cytoarchitecture of laminated brain structures and is produced by a subset of neurons named Cajal-Retzius. After birth, most of these cells degenerate and reelin expression persists in postnatal and adult brain. The phenotype of neurons that bind secreted reelin and whether the continuous secretion of reelin is required for physiological functions at postnatal stages remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Combining immunocytochemical and pharmacological approaches, we first report that two distinct patterns of reelin expression are present in cultured hippocampal neurons. We show that in hippocampal cultures, reelin is secreted by GABAergic neurons displaying an intense reelin immunoreactivity (IR. We demonstrate that secreted reelin binds to receptors of the lipoprotein family on neurons with a punctate reelin IR. Secondly, using calcium imaging techniques, we examined the physiological consequences of reelin secretion blockade. Blocking protein secretion rapidly and reversibly changes the subunit composition of N-methyl-D-aspartate glutamate receptors (NMDARs to a predominance of NR2B-containing NMDARs. Addition of recombinant or endogenously secreted reelin rescues the effects of protein secretion blockade and reverts the fraction of NR2B-containing NMDARs to control levels. Therefore, the continuous secretion of reelin is necessary to control the subunit composition of NMDARs in hippocampal neurons. CONCLUSIONS/SIGNIFICANCE: Our data show that the heterogeneity of reelin immunoreactivity correlates with distinct functional populations: neurons synthesizing and secreting reelin and/or neurons binding reelin. Furthermore, we show that continuous reelin secretion is a strict requirement to maintain the composition of NMDARs. We propose

  5. Developmental regulation of human truncated nerve growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    DiStefano, P.S.; Clagett-Dame, M.; Chelsea, D.M.; Loy, R. (Abbott Laboratories, Abbott Park, IL (USA))

    1991-01-01

    Monoclonal antibodies (designated XIF1 and IIIG5) recognizing distinct epitopes of the human truncated nerve growth factor receptor (NGF-Rt) were used in a two-site radiometric immunosorbent assay to monitor levels of NGF-Rt in human urine as a function of age. Urine samples were collected from 70 neurologically normal subjects ranging in age from 1 month to 68 years. By using this sensitive two-site radiometric immunosorbent assay, NGF-Rt levels were found to be highest in urine from 1-month old subjects. By 2.5 months, NGF-Rt values were half of those seen at 1 month and decreased more gradually between 0.5 and 15 years. Between 15 and 68 years, urine NGF-Rt levels were relatively constant at 5% of 1-month values. No evidence for diurnal variation of adult NGF-Rt was apparent. Pregnant women in their third trimester showed significantly elevated urine NGF-Rt values compared with age-matched normals. Affinity labeling of NGF-Rt with 125I-NGF followed by immunoprecipitation with ME20.4-IgG and gel autoradiography indicated that neonatal urine contained high amounts of truncated receptor (Mr = 50 kd); decreasingly lower amounts of NGF-Rt were observed on gel autoradiograms with development, indicating that the two-site radiometric immunosorbent assay correlated well with the affinity labeling technique for measuring NGF-Rt. NGF-Rt in urines from 1-month-old and 36-year-old subjects showed no differences in affinities for NGF or for the monoclonal antibody IIIG5. These data show that NGF-Rt is developmentally regulated in human urine, and are discussed in relation to the development and maturation of the peripheral nervous system.

  6. Developmental regulation of human truncated nerve growth factor receptor

    International Nuclear Information System (INIS)

    DiStefano, P.S.; Clagett-Dame, M.; Chelsea, D.M.; Loy, R.

    1991-01-01

    Monoclonal antibodies (designated XIF1 and IIIG5) recognizing distinct epitopes of the human truncated nerve growth factor receptor (NGF-Rt) were used in a two-site radiometric immunosorbent assay to monitor levels of NGF-Rt in human urine as a function of age. Urine samples were collected from 70 neurologically normal subjects ranging in age from 1 month to 68 years. By using this sensitive two-site radiometric immunosorbent assay, NGF-Rt levels were found to be highest in urine from 1-month old subjects. By 2.5 months, NGF-Rt values were half of those seen at 1 month and decreased more gradually between 0.5 and 15 years. Between 15 and 68 years, urine NGF-Rt levels were relatively constant at 5% of 1-month values. No evidence for diurnal variation of adult NGF-Rt was apparent. Pregnant women in their third trimester showed significantly elevated urine NGF-Rt values compared with age-matched normals. Affinity labeling of NGF-Rt with 125I-NGF followed by immunoprecipitation with ME20.4-IgG and gel autoradiography indicated that neonatal urine contained high amounts of truncated receptor (Mr = 50 kd); decreasingly lower amounts of NGF-Rt were observed on gel autoradiograms with development, indicating that the two-site radiometric immunosorbent assay correlated well with the affinity labeling technique for measuring NGF-Rt. NGF-Rt in urines from 1-month-old and 36-year-old subjects showed no differences in affinities for NGF or for the monoclonal antibody IIIG5. These data show that NGF-Rt is developmentally regulated in human urine, and are discussed in relation to the development and maturation of the peripheral nervous system

  7. Localization of mineralocorticoid receptors at mammalian synapses.

    Directory of Open Access Journals (Sweden)

    Eric M Prager

    Full Text Available In the brain, membrane associated nongenomic steroid receptors can induce fast-acting responses to ion conductance and second messenger systems of neurons. Emerging data suggest that membrane associated glucocorticoid and mineralocorticoid receptors may directly regulate synaptic excitability during times of stress when adrenal hormones are elevated. As the key neuron signaling interface, the synapse is involved in learning and memory, including traumatic memories during times of stress. The lateral amygdala is a key site for synaptic plasticity underlying conditioned fear, which can both trigger and be coincident with the stress response. A large body of electrophysiological data shows rapid regulation of neuronal excitability by steroid hormone receptors. Despite the importance of these receptors, to date, only the glucocorticoid receptor has been anatomically localized to the membrane. We investigated the subcellular sites of mineralocorticoid receptors in the lateral amygdala of the Sprague-Dawley rat. Immunoblot analysis revealed the presence of mineralocorticoid receptors in the amygdala. Using electron microscopy, we found mineralocorticoid receptors expressed at both nuclear including: glutamatergic and GABAergic neurons and extra nuclear sites including: presynaptic terminals, neuronal dendrites, and dendritic spines. Importantly we also observed mineralocorticoid receptors at postsynaptic membrane densities of excitatory synapses. These data provide direct anatomical evidence supporting the concept that, at some synapses, synaptic transmission is regulated by mineralocorticoid receptors. Thus part of the stress signaling response in the brain is a direct modulation of the synapse itself by adrenal steroids.

  8. Regulation of G protein-coupled receptor signalling: focus on the cardiovascular system and regulator of G protein signalling proteins

    NARCIS (Netherlands)

    Hendriks-Balk, Mariëlle C.; Peters, Stephan L. M.; Michel, Martin C.; Alewijnse, Astrid E.

    2008-01-01

    G protein-coupled receptors (GPCRs) are involved in many biological processes. Therefore, GPCR function is tightly controlled both at receptor level and at the level of signalling components. Well-known mechanisms by which GPCR function can be regulated comprise desensitization/resensitization

  9. Regulated internalization of NMDA receptors drives PKD1-mediated suppression of the activity of residual cell-surface NMDA receptors.

    Science.gov (United States)

    Fang, Xiao-Qian; Qiao, Haifa; Groveman, Bradley R; Feng, Shuang; Pflueger, Melissa; Xin, Wen-Kuan; Ali, Mohammad K; Lin, Shuang-Xiu; Xu, Jindong; Duclot, Florian; Kabbaj, Mohamed; Wang, Wei; Ding, Xin-Sheng; Santiago-Sim, Teresa; Jiang, Xing-Hong; Salter, Michael W; Yu, Xian-Min

    2015-11-19

    Constitutive and regulated internalization of cell surface proteins has been extensively investigated. The regulated internalization has been characterized as a principal mechanism for removing cell-surface receptors from the plasma membrane, and signaling to downstream targets of receptors. However, so far it is still not known whether the functional properties of remaining (non-internalized) receptor/channels may be regulated by internalization of the same class of receptor/channels. The N-methyl-D-aspartate receptor (NMDAR) is a principal subtype of glutamate-gated ion channel and plays key roles in neuronal plasticity and memory functions. NMDARs are well-known to undergo two types of regulated internalization - homologous and heterologous, which can be induced by high NMDA/glycine and DHPG, respectively. In the present work, we investigated effects of regulated NMDAR internalization on the activity of residual cell-surface NMDARs and neuronal functions. In electrophysiological experiments we discovered that the regulated internalization of NMDARs not only reduced the number of cell surface NMDARs but also caused an inhibition of the activity of remaining (non-internalized) surface NMDARs. In biochemical experiments we identified that this functional inhibition of remaining surface NMDARs was mediated by increased serine phosphorylation of surface NMDARs, resulting from the activation of protein kinase D1 (PKD1). Knockdown of PKD1 did not affect NMDAR internalization but prevented the phosphorylation and inhibition of remaining surface NMDARs and NMDAR-mediated synaptic functions. These data demonstrate a novel concept that regulated internalization of cell surface NMDARs not only reduces the number of NMDARs on the cell surface but also causes an inhibition of the activity of remaining surface NMDARs through intracellular signaling pathway(s). Furthermore, modulating the activity of remaining surface receptors may be an effective approach for treating receptor

  10. Both mineralocorticoid and glucocorticoid receptors regulate emotional memory in mice

    NARCIS (Netherlands)

    Zhou, M.; Bakker, E.H.M.; Velzing, E.; Berger, S.; Oitzl, M.; Joëls, M.; Krugers, H.J.

    2010-01-01

    Corticosteroid hormones are thought to promote optimal behavioral adaptation under fearful conditions, primarily via glucocorticoid receptors (GRs). Here, we examined - using pharmacological and genetic approaches in mice - if mineralocorticoid receptors (MRs) also play a role in fearful memory

  11. Antisense-mediated isoform switching of steroid receptor coactivator-1 in the central nucleus of the amygdala of the mouse brain

    Directory of Open Access Journals (Sweden)

    Zalachoras Ioannis

    2013-01-01

    Full Text Available Abstract Background Antisense oligonucleotide (AON-mediated exon skipping is a powerful tool to manipulate gene expression. In the present study we investigated the potential of exon skipping by local injection in the central nucleus of the amygdala (CeA of the mouse brain. As proof of principle we targeted the splicing of steroid receptor coactivator-1 (SRC-1, a protein involved in nuclear receptor function. This nuclear receptor coregulator exists in two splice variants (SRC-1a and SRC-1e which display differential distribution and opposing activities in the brain, and whose mRNAs differ in a single SRC-1e specific exon. Methods For proof of principle of feasibility, we used immunofluorescent stainings to study uptake by different cell types, translocation to the nucleus and potential immunostimulatory effects at different time points after a local injection in the CeA of the mouse brain of a control AON targeting human dystrophin with no targets in the murine brain. To evaluate efficacy we designed an AON targeting the SRC-1e-specific exon and with qPCR analysis we measured the expression ratio of the two splice variants. Results We found that AONs were taken up by corticotropin releasing hormone expressing neurons and other cells in the CeA, and translocated into the cell nucleus. Immune responses after AON injection were comparable to those after sterile saline injection. A successful shift of the naturally occurring SRC-1a:SRC-1e expression ratio in favor of SRC-1a was observed, without changes in total SRC-1 expression. Conclusions We provide a proof of concept for local neuropharmacological use of exon skipping by manipulating the expression ratio of the two splice variants of SRC-1, which may be used to study nuclear receptor function in specific brain circuits. We established that exon skipping after local injection in the brain is a versatile and useful tool for the manipulation of splice variants for numerous genes that are relevant

  12. Nuclear and Membrane Actions of Estrogen Receptor Alpha: Contribution to the Regulation of Energy and Glucose Homeostasis.

    Science.gov (United States)

    Guillaume, Maeva; Montagner, Alexandra; Fontaine, Coralie; Lenfant, Françoise; Arnal, Jean-François; Gourdy, Pierre

    2017-01-01

    Estrogen receptor alpha (ERα) has been demonstrated to play a key role in reproduction but also to exert numerous functions in nonreproductive tissues. Accordingly, ERα is now recognized as a key regulator of energy homeostasis and glucose metabolism and mediates the protective effects of estrogens against obesity and type 2 diabetes. This chapter attempts to summarize our current understanding of the mechanisms of ERα activation and their involvement in the modulation of energy balance and glucose metabolism. We first focus on the experimental studies that constitute the basis of the understanding of ERα as a nuclear receptor and more specifically on the key roles played by its two activation functions (AFs). We depict the consequences of the selective inactivation of these AFs in mouse models, which further underline the prominent role of nuclear ERα in the prevention of obesity and diabetes, as on the reproductive tract and the vascular system. Besides these nuclear actions, a fraction of ERα is associated with the plasma membrane and activates nonnuclear signaling from this site. Such rapid effects, called membrane-initiated steroid signals (MISS), have been characterized in a variety of cell lines and in particular in endothelial cells. The development of selective pharmacological tools that specifically activate MISS as well as the generation of mice expressing an ERα protein impeded for membrane localization has just begun to unravel the physiological role of MISS in vivo and their contribution to ERα-mediated metabolic protection. Finally, we discuss novel perspectives for the design of tissue-selective ER modulators.

  13. Ovarian steroid regulation of monoamine oxidase-A and -B mRNAs in the macaque dorsal raphe and hypothalamic nuclei.

    Science.gov (United States)

    Gundlah, Chrisana; Lu, Nick Z; Bethea, Cynthia L

    2002-03-01

    The serotonin neural system plays a pivotal role in mood, affective regulation and integrative cognition, as well as numerous autonomic functions. We have shown that ovarian steroids alter the expression of several genes in the dorsal raphe of macaques, which may increase serotonin synthesis and decrease serotonin autoinhibition. Another control point in aminergic neurotransmission involves degradation by MAO. This enzyme occurs in two isoforms, A and B, which have different substrate preferences. We questioned the effect of ovarian steroid hormones on MAO-A and MAO-B mRNA expression in the dorsal raphe nucleus and hypothalamus using in situ hybridization in non-human primates. Rhesus monkeys ( Macaca mulatta; n=5/group) were spayed and either placebo treated (controls), estrogen (E) treated (28 days), progesterone (P) treated (14 days placebo+14 days P), or E+P treated (14 days E+14 days E+P). Perfusion-fixed sections (25 microm) were hybridized with a 233 bp MAO-A, or a 373 bp MAO-B, radiolabeled-antisense monkey specific probes. Autoradiographic films were analyzed by densitometry, which was performed with NIH Image Software. MAO-A and -B mRNAs were detected in the dorsal raphe nucleus (DRN) and in the hypothalamic suprachiasmatic nucleus (SCN), preoptic area (POA), paraventricular nucleus (PVN), supraoptic nucleus (SON), lateral hypothalamus (LH) and ventromedial nucleus (VMN). MAO-A mRNA optical density was significantly decreased by E, P, and E+P in the DRN and in the hypothalamic PVN, LH and VMN. Ovarian hormones had no effect on MAO-B mRNA expression in the DRN. However, there was a significant decrease in MAO-B optical density in the hypothalamic POA, LH and VMN with E, P or E+P treatment. Pixel area generally reflected optical density. Ovarian steroids decreased MAO-A, but not B, in the raphe nucleus. However, both MAO-A and B were decreased in discrete hypothalamic nuclei by hormone replacement. These data suggest that the transcriptional regulation of

  14. Org 214007-0: a novel non-steroidal selective glucocorticoid receptor modulator with full anti-inflammatory properties and improved therapeutic index.

    Science.gov (United States)

    van Lierop, Marie-José C; Alkema, Wynand; Laskewitz, Anke J; Dijkema, Rein; van der Maaden, Hans M; Smit, Martin J; Plate, Ralf; Conti, Paolo G M; Jans, Christan G J M; Timmers, C Marco; van Boeckel, Constant A A; Lusher, Scott J; McGuire, Ross; van Schaik, Rene C; de Vlieg, Jacob; Smeets, Ruben L; Hofstra, Claudia L; Boots, Annemieke M H; van Duin, Marcel; Ingelse, Benno A; Schoonen, Willem G E J; Grefhorst, Aldo; van Dijk, Theo H; Kuipers, Folkert; Dokter, Wim H A

    2012-01-01

    Glucocorticoids (GCs) such as prednisolone are potent immunosuppressive drugs but suffer from severe adverse effects, including the induction of insulin resistance. Therefore, development of so-called Selective Glucocorticoid Receptor Modulators (SGRM) is highly desirable. Here we describe a non-steroidal Glucocorticoid Receptor (GR)-selective compound (Org 214007-0) with a binding affinity to GR similar to that of prednisolone. Structural modelling of the GR-Org 214007-0 binding site shows disturbance of the loop between helix 11 and helix 12 of GR, confirmed by partial recruitment of the TIF2-3 peptide. Using various cell lines and primary human cells, we show here that Org 214007-0 acts as a partial GC agonist, since it repressed inflammatory genes and was less effective in induction of metabolic genes. More importantly, in vivo studies in mice indicated that Org 214007-0 retained full efficacy in acute inflammation models as well as in a chronic collagen-induced arthritis (CIA) model. Gene expression profiling of muscle tissue derived from arthritic mice showed a partial activity of Org 214007-0 at an equi-efficacious dosage of prednisolone, with an increased ratio in repression versus induction of genes. Finally, in mice Org 214007-0 did not induce elevated fasting glucose nor the shift in glucose/glycogen balance in the liver seen with an equi-efficacious dose of prednisolone. All together, our data demonstrate that Org 214007-0 is a novel SGRMs with an improved therapeutic index compared to prednisolone. This class of SGRMs can contribute to effective anti-inflammatory therapy with a lower risk for metabolic side effects.

  15. Proximal Tubular Cannabinoid-1 Receptor Regulates Obesity-Induced CKD.

    Science.gov (United States)

    Udi, Shiran; Hinden, Liad; Earley, Brian; Drori, Adi; Reuveni, Noa; Hadar, Rivka; Cinar, Resat; Nemirovski, Alina; Tam, Joseph

    2017-12-01

    Obesity-related structural and functional changes in the kidney develop early in the course of obesity and occur independently of hypertension, diabetes, and dyslipidemia. Activating the renal cannabinoid-1 receptor (CB 1 R) induces nephropathy, whereas CB 1 R blockade improves kidney function. Whether these effects are mediated via a specific cell type within the kidney remains unknown. Here, we show that specific deletion of CB 1 R in the renal proximal tubule cells did not protect the mice from obesity, but markedly attenuated the obesity-induced lipid accumulation in the kidney and renal dysfunction, injury, inflammation, and fibrosis. These effects associated with increased activation of liver kinase B1 and the energy sensor AMP-activated protein kinase, as well as enhanced fatty acid β -oxidation. Collectively, these findings indicate that renal proximal tubule cell CB 1 R contributes to the pathogenesis of obesity-induced renal lipotoxicity and nephropathy by regulating the liver kinase B1/AMP-activated protein kinase signaling pathway. Copyright © 2017 by the American Society of Nephrology.

  16. The aryl hydrocarbon receptor (AHR) transcription factor regulates megakaryocytic polyploidization.

    Science.gov (United States)

    Lindsey, Stephan; Papoutsakis, Eleftherios T

    2011-02-01

    We propose that the aryl hydrocarbon receptor (AHR) is a novel transcriptional regulator of megakaryopoietic polyploidization. Functional evidence was obtained that AHR impacts in vivo megakaryocytic differentiation and maturation; compared to wild-type mice, AHR-null mice had lower platelet counts, fewer numbers of newly synthesized platelets, increased bleeding times and lower-ploidy megakaryocytes (Mks). AHR mRNA increased 3·6-fold during ex vivo megakaryocytic differentiation, but reduced or remained constant during parallel isogenic granulocytic or erythroid differentiation. We interrogated the role of AHR in megakaryopoiesis using a validated Mk model of megakaryopoiesis, the human megakaryoblastic leukaemia CHRF cell line. Upon CHRF Mk differentiation, AHR mRNA and protein levels increased, AHR protein shifted from the cytoplasm to the nucleus and AHR binding to its consensus DNA binding sequence increased. Protein and mRNA levels of the AHR transcriptional target HES1 also increased. Mk differentiation of CHRF cells where AHR or HES1 was knocked-down using RNAi resulted in lower ploidy distributions and cells that were incapable of reaching ploidy classes ≥16n. AHR knockdown also resulted in increased DNA synthesis of lower ploidy cells, without impacting apoptosis. Together, these data support a role for AHR in Mk polyploidization and in vivo platelet function, and warrant further detailed investigations. © 2011 Blackwell Publishing Ltd.

  17. Regulation of Innate Lymphoid Cells by Aryl Hydrocarbon Receptor

    Science.gov (United States)

    Li, Shiyang; Bostick, John W.; Zhou, Liang

    2018-01-01

    With striking similarity to their adaptive T helper cell counterparts, innate lymphoid cells (ILCs) represent an emerging family of cell types that express signature transcription factors, including T-bet+ Eomes+ natural killer cells, T-bet+ Eomes− group 1 ILCs, GATA3+ group 2 ILCs, RORγt+ group 3 ILCs, and newly identified Id3+ regulatory ILC. ILCs are abundantly present in barrier tissues of the host (e.g., the lung, gut, and skin) at the interface of host–environment interactions. Active research has been conducted to elucidate molecular mechanisms underlying the development and function of ILCs. The aryl hydrocarbon receptor (Ahr) is a ligand-dependent transcription factor, best known to mediate the effects of xenobiotic environmental toxins and endogenous microbial and dietary metabolites. Here, we review recent progresses regarding Ahr function in ILCs. We focus on the Ahr-mediated cross talk between ILCs and other immune/non-immune cells in host tissues especially in the gut. We discuss the molecular mechanisms of the action of Ahr expression and activity in regulation of ILCs in immunity and inflammation, and the interaction between Ahr and other pathways/transcription factors in ILC development and function with their implication in disease. PMID:29354125

  18. Regulation of Innate Lymphoid Cells by Aryl Hydrocarbon Receptor

    Directory of Open Access Journals (Sweden)

    Shiyang Li

    2018-01-01

    Full Text Available With striking similarity to their adaptive T helper cell counterparts, innate lymphoid cells (ILCs represent an emerging family of cell types that express signature transcription factors, including T-bet+ Eomes+ natural killer cells, T-bet+ Eomes− group 1 ILCs, GATA3+ group 2 ILCs, RORγt+ group 3 ILCs, and newly identified Id3+ regulatory ILC. ILCs are abundantly present in barrier tissues of the host (e.g., the lung, gut, and skin at the interface of host–environment interactions. Active research has been conducted to elucidate molecular mechanisms underlying the development and function of ILCs. The aryl hydrocarbon receptor (Ahr is a ligand-dependent transcription factor, best known to mediate the effects of xenobiotic environmental toxins and endogenous microbial and dietary metabolites. Here, we review recent progresses regarding Ahr function in ILCs. We focus on the Ahr-mediated cross talk between ILCs and other immune/non-immune cells in host tissues especially in the gut. We discuss the molecular mechanisms of the action of Ahr expression and activity in regulation of ILCs in immunity and inflammation, and the interaction between Ahr and other pathways/transcription factors in ILC development and function with their implication in disease.

  19. Nuclear Receptors in atherosclerosis: a superfamily with many 'Goodfellas'

    NARCIS (Netherlands)

    Kurakula, Kondababu; Hamers, Anouk A. J.; de Waard, Vivian; de Vries, Carlie J. M.

    2013-01-01

    Nuclear Receptors form a superfamily of 48 transcription factors that exhibit a plethora of functions in steroid hormone signaling, regulation of metabolism, circadian rhythm and cellular differentiation. In this review, we describe our current knowledge on the role of Nuclear Receptors in

  20. Liver X receptor α and farnesoid X receptor are major transcriptional regulators of OATP1B1.

    Science.gov (United States)

    Meyer Zu Schwabedissen, Henriette E; Böttcher, Kerstin; Chaudhry, Amarjit; Kroemer, Heyo K; Schuetz, Erin G; Kim, Richard B

    2010-11-01

    Organic anion transporting polypeptide 1B1 (OATP1B1) is a liver-enriched transporter involved in the hepatocellular uptake of many endogenous molecules and several structurally divergent drugs in clinical use. Although OATP1B1 coding region polymorphisms are known to make an impact on substrate drug disposition in humans, little is known regarding the mechanisms underlying the transcriptional regulation of this transporter. In this study, we note that messenger RNA (mRNA) expression of OATP1B1 in a large human liver bank exhibited marked interindividual variability that was not associated with coding region polymorphisms. Accordingly, we hypothesized that such variability in expression is reflective of nuclear receptor-mediated transcriptional regulation of this transporter. We tested prototypical ligands for the nuclear receptors pregnane X receptor (PXR), constitutive androstane receptor (CAR), liver X receptor (LXR) α, and farnesoid X receptor (FXR) in a human hepatoma-derived cell line and noted induction of OATP1B1 mRNA when the cells were treated with LXRα or FXR ligands. To confirm a direct role for LXRα and FXR to OATP1B1 expression, we performed detailed promoter analysis and cell-based reporter gene assays resulting in the identification of two functional FXR response elements and one LXRα response element. The direct interaction between nuclear receptors with the identified response elements was assessed using chromatin immunoprecipitation assays. Using isolated primary human hepatocytes, we show that LXRα or FXR agonists, but not PXR or CAR agonists, are capable of OATP1B1 induction. We note that OATP1B1 transcriptional regulation is under dual nuclear receptor control through the oxysterol sensing LXRα and the bile acid sensor FXR. Accordingly, the interplay between OATP1B1 and nuclear receptors may play an important and heretofore unrecognized role during cholestasis, drug-induced liver injury, and OATP1B1 induction-related drug interactions.

  1. Phallusiasterol C, A New Disulfated Steroid from the Mediterranean Tunicate Phallusia fumigata

    Directory of Open Access Journals (Sweden)

    Concetta Imperatore

    2016-06-01

    Full Text Available A new sulfated sterol, phallusiasterol C (1, has been isolated from the Mediterranean ascidian Phallusia fumigata and its structure has been determined on the basis of extensive spectroscopic (mainly 2D NMR analysis. The possible role in regulating the pregnane X receptor (PXR activity of phallusiasterol C has been investigated; although the new sterol resulted inactive, this study adds more items to the knowledge of the structure-PXR regulating activity relationships in the case of sulfated steroids.

  2. Postmenopausal Serum Sex Steroids and Risk of Hormone Receptor-Positive and -Negative Breast Cancer : a Nested Case-Control Study

    NARCIS (Netherlands)

    James, Rebecca E.; Lukanova, Annekatrin; Dossus, Laure; Becker, Susen; Rinaldi, Sabina; Tjonneland, Anne; Olsen, Anja; Overvad, Kim; Mesrine, Sylvie; Engel, Pierre; Clavel-Chapelon, Francoise; Chang-Claude, Jenny; Vrieling, Alina; Boeing, Heiner; Schuetze, Madlen; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Palli, Domenico; Krogh, Vittorio; Panico, Salvatore; Tumino, Rosario; Sacerdote, Carlotta; Rodriguez, Laudina; Buckland, Genevieve; Sanchez, Maria-Jose; Amiano, Pilar; Ardanaz, Eva; Bueno-de-Mesquita, Bas; Ros, Martine M.; van Gils, Carla H.; Peeters, Petra H.; Khaw, Kay-Tee; Wareham, Nick; Key, Timothy J.; Allen, Naomi E.; Romieu, Isabelle; Siddiq, Afshan; Cox, David; Riboli, Elio; Kaaks, Rudolf

    2011-01-01

    Prediagnostic endogenous sex steroid hormone levels have well established associations with overall risk of breast cancer. While evidence toward the existence of distinct subtypes of breast cancer accumulates, few studies have investigated the associations of sex steroid hormone levels with risk of

  3. Postmenopausal serum sex steroids and risk of hormone receptor-positive and -negative breast cancer: a nested case-control study

    NARCIS (Netherlands)

    James, R.E.; Lukanova, A.; Dossus, L.; Becker, S.; Rinaldi, S.; Tjonneland, A.; Olsen, A.; Overvad, K.; Mesrine, S.; Engel, P.; Clavel-Chapelon, F.; Chang-Claude, J.; Vrieling, A.; Boeing, H.; Schutze, M.; Trichopoulou, A.; Lagiou, P.; Trichopoulos, D.; Palli, D.; Krogh, V.; Panico, S.; Tumino, R.; Sacerdote, C.; Rodriguez, L.; Buckland, G.; Sanchez, M.J.; Amiano, P.; Ardanaz, E.; Bueno-de-Mesquita, B.; Ros, M.M.; Gils, C.H. van; Peeters, P.H.M.; Khaw, K.T.; Wareham, N.; Key, T.J.; Allen, N.E.; Romieu, I.; Siddiq, A.; Cox, D.; Riboli, E.; Kaaks, R.

    2011-01-01

    Prediagnostic endogenous sex steroid hormone levels have well established associations with overall risk of breast cancer. While evidence toward the existence of distinct subtypes of breast cancer accumulates, few studies have investigated the associations of sex steroid hormone levels with risk of

  4. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...) Show The negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne...gative regulation of Toll-like receptor and associated pathways. Authors Lang T,

  5. Role of estrogen receptors in the regulation of reactive gliosis

    Directory of Open Access Journals (Sweden)

    Luis Miguel Garcia-Segura

    2015-02-01

    Full Text Available Although estradiol may directly act on neurons to promote neuroprotection in vitro, the participation of other cell types is also necessary to maintain global tissue homeostasis in vivo (Arevalo et al., 2010; Johann and Beyer, 2013; Acaz-Fonseca et al., 2014. Thus, estradiol acts on glial and endothelial cells to maintain the function of the neurovascular unit, regulates gliosis and the inflammatory response of astrocytes and microglia to control neuroinflammation and acts on neurons, astrocytes and oligodendrocytes to maintain the function and propagating properties of neuronal circuits (Garcia-Ovejero et al., 2005; Tapia-Gonzalez et al., 2008; Barrerto et al., 2009; Cerciat et al., 2010; López Rodríguez et al., 2011; Barreto et al., 2014. Glial cells express estrogen receptors (ERs, including ERalpha, ERbeta and G protein-coupled estrogen receptor-1 (GPER (Garcia-Ovjero et al., 2005; Dhandapani and Brann, 2007 and brain injury induces both the synthesis of estradiol in both reactive astrocytes and the expression of ERs in these cells (Garcia-Ovejero et al., 2002. This suggests that astrocytes may play an important role in the neuroprotective actions of estradiol. Indeed, recent studies, using conditional KO mice for ERalpha and ERbeta, have shown that in an experimental model of multiple sclerosis the protective action of estradiol is mediated by ERalpha expressed in astrocytes, but not by ERalpha expressed in neurons or ERbeta expressed in astrocytes or neurons (Spence et al., 2013. ERs in glial cells activate several neuroprotective mechanisms in response to estradiol, including the release of factors that have trophic effects on neurons and other cell types and the control of neuroinflammation, edema and extracellular glutamate levels. Classical ERs associated with the plasma membrane of astrocytes are involved in the estradiol-induced release of transforming growth factor (TGF-beta, through the activation of the PI3K/Akt signaling

  6. C/EBP maintains chromatin accessibility in liver and facilitates glucocorticoid receptor recruitment to steroid response elements

    DEFF Research Database (Denmark)

    Grøntved, Lars; John, Sam; Baek, Songjoon

    2013-01-01

    -binding sites are occupied by C/EBPβ. At the majority of these sites, chromatin is preaccessible suggesting a priming function of C/EBPβ for GR recruitment. Disruption of C/EBPβ binding to chromatin results in attenuation of pre-programmed chromatin accessibility, GR recruitment and GR-induced chromatin...... remodelling specifically at sites co-occupied by GR and C/EBPβ. Collectively, we demonstrate a highly cooperative mechanism by which C/EBPβ regulates selective GR binding to the genome in liver tissue. We suggest that selective targeting of GR in other tissues is likely mediated by the combined action of cell...

  7. Proteolytic regulation of Notch1 receptor activity in cancer

    NARCIS (Netherlands)

    van Tetering, Geert

    2011-01-01

    The Notch receptor is part of a highly conserved signaling pathway essential in development and disease in embryos and adults. Notch proteins coordinate cell-cell communication through receptor-ligand interactions between adjacent cells. First Notch is cleaved in the Golgi by furin at Site-1 (S1)

  8. Glycosylation as a Main Regulator of Growth and Death Factor Receptors Signaling

    Directory of Open Access Journals (Sweden)

    Inês Gomes Ferreira

    2018-02-01

    Full Text Available Glycosylation is a very frequent and functionally important post-translational protein modification that undergoes profound changes in cancer. Growth and death factor receptors and plasma membrane glycoproteins, which upon activation by extracellular ligands trigger a signal transduction cascade, are targets of several molecular anti-cancer drugs. In this review, we provide a thorough picture of the mechanisms bywhich glycosylation affects the activity of growth and death factor receptors in normal and pathological conditions. Glycosylation affects receptor activity through three non-mutually exclusive basic mechanisms: (1 by directly regulating intracellular transport, ligand binding, oligomerization and signaling of receptors; (2 through the binding of receptor carbohydrate structures to galectins, forming a lattice thatregulates receptor turnover on the plasma membrane; and (3 by receptor interaction with gangliosides inside membrane microdomains. Some carbohydrate chains, for example core fucose and β1,6-branching, exert a stimulatory effect on all receptors, while other structures exert opposite effects on different receptors or in different cellular contexts. In light of the crucial role played by glycosylation in the regulation of receptor activity, the development of next-generation drugs targeting glyco-epitopes of growth factor receptors should be considered a therapeutically interesting goal.

  9. Alterations in the steroid hormone receptor co-chaperone FKBPL are associated with male infertility: a case-control study

    LENUS (Irish Health Repository)

    Sunnotel, Olaf

    2010-03-08

    Abstract Background Male infertility is a common cause of reproductive failure in humans. In mice, targeted deletions of the genes coding for FKBP6 or FKBP52, members of the FK506 binding protein family, can result in male infertility. In the case of FKBP52, this reflects an important role in potentiating Androgen Receptor (AR) signalling in the prostate and accessory glands, but not the testis. In infertile men, no mutations of FKBP52 or FKBP6 have been found so far, but the gene for FKBP-like (FKBPL) maps to chromosome 6p21.3, an area linked to azoospermia in a group of Japanese patients. Methods To determine whether mutations in FKBPL could contribute to the azoospermic phenotype, we examined expression in mouse and human tissues by RNA array blot, RT-PCR and immunohistochemistry and sequenced the complete gene from two azoospermic patient cohorts and matching control groups. FKBPL-AR interaction was assayed using reporter constructs in vitro. Results FKBPL is strongly expressed in mouse testis, with expression upregulated at puberty. The protein is expressed in human testis in a pattern similar to FKBP52 and also enhanced AR transcriptional activity in reporter assays. We examined sixty patients from the Japanese patient group and found one inactivating mutation and one coding change, as well as a number of non-coding changes, all absent in fifty-six controls. A second, Irish patient cohort of thirty showed another two coding changes not present in thirty proven fertile controls. Conclusions Our results describe the first alterations in the gene for FKBPL in azoospermic patients and indicate a potential role in AR-mediated signalling in the testis.

  10. Alterations in the steroid hormone receptor co-chaperone FKBPL are associated with male infertility: a case-control study

    Directory of Open Access Journals (Sweden)

    Barton David

    2010-03-01

    Full Text Available Abstract Background Male infertility is a common cause of reproductive failure in humans. In mice, targeted deletions of the genes coding for FKBP6 or FKBP52, members of the FK506 binding protein family, can result in male infertility. In the case of FKBP52, this reflects an important role in potentiating Androgen Receptor (AR signalling in the prostate and accessory glands, but not the testis. In infertile men, no mutations of FKBP52 or FKBP6 have been found so far, but the gene for FKBP-like (FKBPL maps to chromosome 6p21.3, an area linked to azoospermia in a group of Japanese patients. Methods To determine whether mutations in FKBPL could contribute to the azoospermic phenotype, we examined expression in mouse and human tissues by RNA array blot, RT-PCR and immunohistochemistry and sequenced the complete gene from two azoospermic patient cohorts and matching control groups. FKBPL-AR interaction was assayed using reporter constructs in vitro. Results FKBPL is strongly expressed in mouse testis, with expression upregulated at puberty. The protein is expressed in human testis in a pattern similar to FKBP52 and also enhanced AR transcriptional activity in reporter assays. We examined sixty patients from the Japanese patient group and found one inactivating mutation and one coding change, as well as a number of non-coding changes, all absent in fifty-six controls. A second, Irish patient cohort of thirty showed another two coding changes not present in thirty proven fertile controls. Conclusions Our results describe the first alterations in the gene for FKBPL in azoospermic patients and indicate a potential role in AR-mediated signalling in the testis.

  11. Regulation of P2Y1 receptor traffic by sorting Nexin 1 is retromer independent.

    Science.gov (United States)

    Nisar, Shaista; Kelly, Eamonn; Cullen, Pete J; Mundell, Stuart J

    2010-04-01

    The activity and traffic of G-protein coupled receptors (GPCRs) is tightly controlled. Recent work from our laboratory has shown that P2Y(1) and P2Y(12) responsiveness is rapidly and reversibly modulated in human platelets and that the underlying mechanism requires receptor trafficking as an essential part of this process. However, little is known about the molecular mechanisms underlying P2Y receptor traffic. Sorting nexin 1 (SNX1) has been shown to regulate the endosomal sorting of cell surface receptors either to lysosomes where they are downregulated or back to the cell surface. These functions may in part be due to interactions of SNX1 with the mammalian retromer complex. In this study, we investigated the role of SNX1 in P2Y receptor trafficking. We show that P2Y(1) receptors recycle via a slow recycling pathway that is regulated by SNX1, whereas P2Y(12) receptors return to the cell surface via a rapid route that is SNX1 independent. SNX1 inhibition caused a dramatic increase in the rate of P2Y(1) receptor recycling, whereas inhibition of Vps26 and Vps35 known to be present in retromer had no effect, indicating that SNX1 regulation of P2Y(1) receptor recycling is retromer independent. In addition, inhibition of SNX4, 6 and 17 proteins did not affect P2Y(1) receptor recycling. SNX1 has also been implicated in GPCR degradation; however, we provide evidence that P2Y receptor degradation is SNX1 independent. These data describe a novel function of SNX1 in the regulation of P2Y(1) receptor recycling and suggest that SNX1 plays multiple roles in endocytic trafficking of GPCRs.

  12. Epigenetic control of vasopressin expression is maintained by steroid hormones in the adult male rat brain

    Science.gov (United States)

    Auger, Catherine J.; Coss, Dylan; Auger, Anthony P.; Forbes-Lorman, Robin M.

    2011-01-01

    Although some DNA methylation patterns are altered by steroid hormone exposure in the developing brain, less is known about how changes in steroid hormone levels influence DNA methylation patterns in the adult brain. Steroid hormones act in the adult brain to regulate gene expression. Specifically, the expression of the socially relevant peptide vasopressin (AVP) within the bed nucleus of the stria terminalis (BST) of adult brain is dependent upon testosterone exposure. Castration dramatically reduces and testosterone replacement restores AVP expression within the BST. As decreases in mRNA expression are associated with increases in DNA promoter methylation, we explored the hypothesis that AVP expression in the adult brain is maintained through sustained epigenetic modifications of the AVP gene promoter. We find that castration of adult male rats resulted in decreased AVP mRNA expression and increased methylation of specific CpG sites within the AVP promoter in the BST. Similarly, castration significantly increased estrogen receptor α (ERα) mRNA expression and decreased ERα promoter methylation within the BST. These changes were prevented by testosterone replacement. This suggests that the DNA promoter methylation status of some steroid responsive genes in the adult brain is actively maintained by the presence of circulating steroid hormones. The maintenance of methylated or demethylated states of some genes in the adult brain by the presence of steroid hormones may play a role in the homeostatic regulation of behaviorally relevant systems. PMID:21368111

  13. Dopamine D3 receptors regulate reconsolidation of cocaine memory.

    Science.gov (United States)

    Yan, Y; Kong, H; Wu, E J; Newman, A H; Xu, M

    2013-06-25

    Memories of learned associations between the rewarding properties of drugs of abuse and environmental cues contribute to craving and relapse in humans. Disruption of reconsolidation dampens or even erases previous memories. Dopamine (DA) mediates the acquisition of reward memory and drugs of abuse can pathologically change related neuronal circuits in the mesolimbic DA system. Previous studies showed that DA D3 receptors are involved in cocaine-conditioned place preference (CPP) and reinstatement of cocaine-seeking behavior. However, the role of D3 receptors in reconsolidation of cocaine-induced reward memory remains unclear. In the present study, we combined genetic and pharmacological approaches to investigate the role of D3 receptors in reconsolidation of cocaine-induced CPP. We found that the mutation of the D3 receptor gene weakened reconsolidation of cocaine-induced CPP in mice triggered by a 3-min (min) retrieval. Furthermore, treatment of a selective D3 receptor antagonist PG01037 immediately following the 3-min retrieval disrupted reconsolidation of cocaine-induced CPP in wild-type mice and such disruption remained at least 1 week after the 3-min retrieval. These results suggest that D3 receptors play a key role in reconsolidation of cocaine-induced CPP in mice, and that pharmacological blockade of these receptors may be therapeutic for the treatment of cocaine craving and relapse in clinical settings. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Environmental impacts on the gonadotropic system in female Atlantic salmon (Salmo salar) during vitellogenesis: Photothermal effects on pituitary gonadotropins, ovarian gonadotropin receptor expression, plasma sex steroids and oocyte growth.

    Science.gov (United States)

    Taranger, Geir Lasse; Muncaster, Simon; Norberg, Birgitta; Thorsen, Anders; Andersson, Eva

    2015-09-15

    The gonadotropic system and ovarian growth and development were studied during vitellogenesis in female Atlantic salmon subjected to either simulated natural photoperiod and ambient water temperature (NL-amb), or an accelerating photoperiod (short day of LD8:16 from May 10) combined with either warmed (ca 2°C above ambient; 8L-warm) or cooled water (ca 2°C below ambient; 8L-cold) from May to September. Monthly samples were collected from 10 females/group for determination of transcript levels of pituitary gonadotropin subunits (fshb and lhb) and ovarian gonadotropin receptors (fshr and lhr), plasma sex steroids (testosterone: T and estradiol-17β: E2), gonadosomatic index (GSI) and oocyte size. Short day in combination with either warmed or cooled water induced an earlier increase in pituitary fshb and lhb levels compared with NL-amb controls, and advanced ovarian growth and the seasonal profiles of T, E2. By contrast only minor effects were seen of the photothermal treatments on ovarian fshr and lhr. The 8L-cold had earlier increase in fshb, lhb and E2, but similar oocyte and gonadal growth as 8L-warm, suggesting that the 8L-cold group tried to compensate for the lower water temperature during the period of rapid gonadal growth by increasing fshb and E2 production. Both the 8L-warm and 8L-cold groups showed incomplete ovulation in a proportion of the females, possibly due to the photoperiod advancement resulting in earlier readiness of spawning occurring at a higher ambient temperature, or due to some reproductive dysfunction caused by photothermal interference with normal neuroendocrine regulation of oocyte development and maturation. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. The role of the 5-HT1a receptor in central cardiovascular regulation

    NARCIS (Netherlands)

    G.H. Dreteler

    1991-01-01

    textabstractThe aim of the studies describe~ in this thesis is to further clarify the role of the 5- HT1A receptor in central cardiovascular regulation. The hypotensive action of 5-HT1A receptor agonists is mainly due to differential sympatho-inhibition resulting in an increase in total

  16. PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner

    NARCIS (Netherlands)

    Sjöqvist, M.; Antfolk, D.; Ferraris, S.; Rraklli, V.; Haga, C.; Antila, C.; Mutvei, A.; Imanishi, S.Y.; Holmberg, J.; Jin, S.; Eriksson, J.E.; Lendahl, U.; Sahlgren, C.M.

    Activation of Notch signaling requires intracellular routing of the receptor, but the mechanisms controlling the distinct steps in the routing process is poorly understood. We identify PKCζ as a key regulator of Notch receptor intracellular routing. When PKCζ was inhibited in the developing chick

  17. DNA Repair, Redox Regulation and Modulation of Estrogen Receptor Alpha Mediated Transcription

    Science.gov (United States)

    Curtis-Ducey, Carol Dianne

    2009-01-01

    Interaction of estrogen receptor [alpha] (ER[alpha]) with 17[beta]-estradiol (E[subscript 2]) facilitates binding of the receptor to estrogen response elements (EREs) in target genes, which in turn leads to recruitment of coregulatory proteins. To better understand how estrogen-responsive genes are regulated, our laboratory identified a number of…

  18. Ligand-mediated negative regulation of a chimeric transmembrane receptor tyrosine phosphatase

    DEFF Research Database (Denmark)

    Desai, D M; Sap, J; Schlessinger, J

    1993-01-01

    CD45, a transmembrane protein tyrosine phosphatase (PTPase), is required for TCR signaling. Multiple CD45 isoforms, differing in the extracellular domain, are expressed in a tissue- and activation-specific manner, suggesting an important function for this domain. We report that a chimeric protein...... that ligand-mediated regulation of receptor-PTPases may have mechanistic similarities with receptor tyrosine kinases....

  19. Selective Androgen Receptor Down-Regulators (SARDs): A New Prostate Cancer Therapy

    National Research Council Canada - National Science Library

    Bhattacharyya, Rumi S

    2007-01-01

    The androgen receptor (AR) plays a key role in the development and progression of prostate cancer Targeting the AR for down-regulation would be a useful strategy for treating prostate cancer, especially hormone-refractory...

  20. GABAB receptor phosphorylation regulates KCTD12-induced K+ current desensitization

    DEFF Research Database (Denmark)

    Adelfinger, L; Turecek, R; Ivankova, K

    2014-01-01

    released from the G-protein. Receptor-activated K+ currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K+ currents integrates distinct mechanistic underpinnings. GABAB receptor activity reduces protein kinase-A activity, which...... reduces phosphorylation of serine-892 in GABAB2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G......-protein βγ subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast...

  1. Molecular Mechanisms of β2-Adrenergic Receptor Function and Regulation

    OpenAIRE

    McGraw, Dennis W.; Liggett, Stephen B.

    2005-01-01

    It is now clear that the β2-adrenergic receptor continuously oscillates between various conformations in the basal state, and that agonists act to stabilize one or more conformations. It is conceivable that synthetic agonists might be engineered to preferentially confine the receptor to certain conformations deemed clinically important while having a less stabilizing effect on unwanted conformations. In addition, studies of genetically engineered mice have revealed previously unrecognized cro...

  2. The allosteric site regulates the voltage sensitivity of muscarinic receptors.

    Science.gov (United States)

    Hoppe, Anika; Marti-Solano, Maria; Drabek, Matthäus; Bünemann, Moritz; Kolb, Peter; Rinne, Andreas

    2018-01-01

    Muscarinic receptors (M-Rs) for acetylcholine (ACh) belong to the class A of G protein-coupled receptors. M-Rs are activated by orthosteric agonists that bind to a specific site buried in the M-R transmembrane helix bundle. In the active conformation, receptor function can be modulated either by allosteric modulators, which bind to the extracellular receptor surface or by the membrane potential via an unknown mechanism. Here, we compared the modulation of M 1 -Rs and M 3 -Rs induced by changes in voltage to their allosteric modulation by chemical compounds. We quantified changes in receptor signaling in single HEK 293 cells with a FRET biosensor for the G q protein cycle. In the presence of ACh, M 1 -R signaling was potentiated by voltage, similarly to positive allosteric modulation by benzyl quinolone carboxylic acid. Conversely, signaling of M 3 -R was attenuated by voltage or the negative allosteric modulator gallamine. Because the orthosteric site is highly conserved among M-Rs, but allosteric sites vary, we constructed "allosteric site" M 3 /M 1 -R chimeras and analyzed their voltage dependencies. Exchanging the entire allosteric sites eliminated the voltage sensitivity of ACh responses for both receptors, but did not affect their modulation by allosteric compounds. Furthermore, a point mutation in M 3 -Rs caused functional uncoupling of the allosteric and orthosteric sites and abolished voltage dependence. Molecular dynamics simulations of the receptor variants indicated a subtype-specific crosstalk between both sites, involving the conserved tyrosine lid structure of the orthosteric site. This molecular crosstalk leads to receptor subtype-specific voltage effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Determination of estradiol, estrone and progesterone in serum and human endometrium in correlation to the content of steroid receptors and 17β-hydroxysteroid dehydrogenase activity during menstrual cycle

    International Nuclear Information System (INIS)

    Schmidt-Gollwitzer, M.; Eiletz, J.; Pachaly, J.

    1977-01-01

    A study has been carried out to compare the influence of estradiol estrone and progesterone on the estradiol and progesterone receptor levels and 17β-hydroxysteroid dehydrogenase (17β-HSD) activity in human endometrium. The steroid hormone concentrations were measured simultaneously in both serum and endometrial tissue. The estradiol receptor levels were highest during the early proliferative phase and were inversely correlated to the endometrial tissue and serum concentrations of estradiol and progesterone. The highest progesterone binding capacity was found in endometrical cytosol during the late proliferative phase (midcycle) of the menstrual cycle. The midcycle peak of the progesterone receptor level correlated well with the first peak of the serum and tissue concentrations of estradiol. During,the luteal phase, in contrast to the proliferative phase, the progesterone receptor level decreased whereas serum progesterone concentrations were high. Estrone concentrations were higher in secretory than proliferative endometrium and were correlated to the increase of progesterone receptor content and 17β-HSD activity during early secretory phase. The 17β-HSD activity was approximately 10-fold higher during the early secretory than during the proliferative phase. The progesterone receptor level was highly correlated to the specific 17β-HSD activity of the microsomal fraction whereas a significant inverse correlation between the enzyme activity and the estradiol receptor level was observed. (orig.) [de

  4. GABA_A receptor function is regulated by lipid bilayer elasticity

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Werge, Thomas; Berthelsen, Camilla

    2006-01-01

    ( s) underlying these effects are poorly understood. DHA and Triton X-100, at concentrations that affect GABAA receptor function, increase the elasticity of lipid bilayers measured as decreased bilayer stiffness using gramicidin channels as molecular force transducers. We have previously shown...... reduced the peak amplitude of the GABA-induced currents and increased the rate of receptor desensitization. The effects of the amphiphiles did not correlate with the expected changes in monolayer spontaneous curvature. We conclude that GABAA receptor function is regulated by lipid bilayer elasticity....... PUFAs may generally regulate membrane protein function by affecting the elasticity of the host lipid bilayer....

  5. Serotonin 2A receptors contribute to the regulation of risk-averse decisions

    DEFF Research Database (Denmark)

    Macoveanu, Julian; Rowe, James B; Hornboll, Bettina

    2013-01-01

    Pharmacological studies point to a role of the neurotransmitter serotonin (5-HT) in regulating the preference for risky decisions, yet the functional contribution of specific 5-HT receptors remains to be clarified. We used pharmacological fMRI to investigate the role of the 5-HT2A receptors...... in processing negative outcomes and regulating risk-averse behavior. During fMRI, twenty healthy volunteers performed a gambling task under two conditions: with or without blocking the 5-HT2A receptors. The volunteers repeatedly chose between small, likely rewards and large, unlikely rewards. Choices were...

  6. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Science.gov (United States)

    Liu, Qiang; Zhang, Juan; Zerbinatti, Celina; Zhan, Yan; Kolber, Benedict J; Herz, Joachim; Muglia, Louis J; Bu, Guojun

    2011-01-11

    Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  7. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    2011-01-01

    Full Text Available Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  8. Light regulation of the insulin receptor in the retina.

    Science.gov (United States)

    Rajala, Raju V S; Anderson, Robert E

    2003-10-01

    The peptide hormone insulin binds its cognate cell-surface receptors to activate a coordinated biochemical-signaling network and to induce intracellular events. The retina is an integral part of the central nervous system and is known to contain insulin receptors, although their function is unknown. This article, describes recent studies that link the photobleaching of rhodopsin to tyrosine phosphorylation of the insulin receptor and subsequent activation of phosphoinositide 3- kinase (PI3K). We recently found a light-dependent increase in tyrosine phosphorylation of the insulin receptor-beta-subunit (IR beta) and an increase in PI3K enzyme activity in isolated rod outer segments (ROS) and in anti-phosphotyrosine (PY) and anti-IR beta immunoprecipitates of retinal homogenates. The light effect, which was localized to photoreceptor neurons, is independent of insulin secretion. Our results suggest that light induces tyrosine phosphorylation of IR beta in outer-segment membranes, which leads to the binding of p85 through its N-terminal SH2 domain and the generation of PI-3,4,5-P3. We suggest that the physiological role of this process may be to provide neuroprotection of the retina against light damage by activating proteins that protect against stress-induced apoptosis. The studies linking PI3K activation through tyrosine phosphorylation of IR beta now provide physiological relevance for the presence of these receptors in the retina.

  9. Arrestin scaffolds NHERF1 to the P2Y12 receptor to regulate receptor internalization.

    Science.gov (United States)

    Nisar, Shaista P; Cunningham, Margaret; Saxena, Kunal; Pope, Robert J; Kelly, Eamonn; Mundell, Stuart J

    2012-07-13

    We have recently shown in a patient with mild bleeding that the PDZ-binding motif of the platelet G protein-coupled P2Y(12) receptor (P2Y(12)R) is required for effective receptor traffic in human platelets. In this study we show for the first time that the PDZ motif-binding protein NHERF1 exerts a major role in potentiating G protein-coupled receptor (GPCR) internalization. NHERF1 interacts with the C-tail of the P2Y(12)R and unlike many other GPCRs, NHERF1 interaction is required for effective P2Y(12)R internalization. In vitro and prior to agonist stimulation P2Y(12)R/NHERF1 interaction requires the intact PDZ binding motif of this receptor. Interestingly on receptor stimulation NHERF1 no longer interacts directly with the receptor but instead binds to the receptor via the endocytic scaffolding protein arrestin. These findings suggest a novel model by which arrestin can serve as an adaptor to promote NHERF1 interaction with a GPCR to facilitate effective NHERF1-dependent receptor internalization.

  10. Selective suppression of endothelial cytokine production by progesterone receptor

    OpenAIRE

    Goddard, Lauren M.; Ton, Amy N.; Org, Tõnis; Mikkola, Hanna K.A.; Iruela-Arispe, M. Luisa

    2013-01-01

    Steroid hormones are well-recognized suppressors of the inflammatory response, however, their cell- and tissue-specific effects in the regulation of inflammation are far less understood, particularly for the sex-related steroids. To determine the contribution of progesterone in the endothelium, we have characterized and validated an in vitro culture system in which human umbilical vein endothelial cells constitutively express human progesterone receptor (PR). Using next generation RNA-sequenc...

  11. UDP/P2Y6 receptor signaling regulates IgE-dependent degranulation in human basophils

    Directory of Open Access Journals (Sweden)

    Manabu Nakano

    2017-10-01

    Conclusions: This study showed that UDP/P2Y6 receptor signaling is involved in the regulation of IgE-dependent degranulation in basophils, which might stimulate the P2Y6 receptor via the autocrine secretion of UTP. Thus, this receptor represents a potential target to regulate IgE-dependent degranulation in basophils during allergic diseases.

  12. Differential Regulation of Receptor Activation and Agonist Selectivity by Highly Conserved Tryptophans in the Nicotinic Acetylcholine Receptor Binding Site

    OpenAIRE

    Williams, Dustin K.; Stokes, Clare; Horenstein, Nicole A.; Papke, Roger L.

    2009-01-01

    We have shown previously that a highly conserved Tyr in the nicotinic acetylcholine receptor (nAChR) ligand-binding domain (LBD) (α7 Tyr188 or α4 Tyr195) differentially regulates the activity of acetylcholine (ACh) and the α7-selective agonist 3-(4-hydroxy,2-methoxybenzylidene)anabaseine (4OH-GTS-21) in α4β2 and α7 nAChR. In this study, we mutated two highly conserved LBD Trp residues in human α7 and α4β2 and expressed the receptors in Xenopus laevis oocytes. α7 Re...

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

    Science.gov (United States)

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

    2007-01-01

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

  14. HR38, an ortholog of NR4A family nuclear receptors, mediates 20-hydroxyecdysone regulation of carbohydrate metabolism during mosquito reproduction.

    Science.gov (United States)

    Dong, Dujuan; Zhang, Yang; Smykal, Vlastimil; Ling, Lin; Raikhel, Alexander S

    2018-05-01

    The Aedes aegypti mosquito is the principal vector for many dangerous human viral diseases. Carbohydrate metabolism (CM) is essential for supplying the energy necessary for host seeking, blood digestion and rapid egg development of this vector insect. The steroid hormone 20-hydroxyecdysone (20E) and the ecdysone receptor (EcR) are important regulators of CM, coordinating it with female reproductive events. We report here that the NR4A nuclear receptor AHR38 plays a critical role in mediating these actions of 20E and EcR. AHR38 RNA interference (RNAi) depletion in female mosquitoes blocked the transcriptional activation of CM genes encoding phosphoglucomutase (PGM) and trehalose-6-phophate synthase (TPS); it caused an increase of glycogen accumulation and a decrease of the circulating sugar trehalose. This treatment also resulted in a dramatic reduction in fecundity. Considering that these phenotypes resulting from AHR38 RNAi depletion are similar to those of EcR RNAi, we investigated a possible connection between these transcription factors in CM regulation. EcR RNAi inhibits the AHR38 gene expression. Moreover, the 20E-induced EcR complex directly activates AHR38 by binding to the ecdysone response element (EcRE) in the upstream regulatory region of this gene. The present work has implicated AHR38 in the 20E-mediated control of CM and provided new insight into mechanisms of 20E regulation of metabolism during female mosquito reproduction. © 2018 Published by Elsevier Ltd.

  15. Melanocortin 4 receptor is not required for estrogenic regulations on energy homeostasis and reproduction

    Science.gov (United States)

    Brain estrogen receptor-a (ERa) is essential for estrogenic regulation of energy homeostasis and reproduction. We previously showed that ERa expressed by pro-opiomelanocortin (POMC) neurons mediates estrogen's effects on food intake, body weight, negative regulation of hypothalamic–pituitary–gonadal...

  16. In vivo regulation of the serotonin-2 receptor in rat brain

    International Nuclear Information System (INIS)

    Stockmeier, C.A.; Kellar, K.J.

    1986-01-01

    Serotonin-2 (5-HT-2) receptors in brain were measured using ( 3 H)ketanserin. The authors examined the effects of amitriptyline, an anti-depressant drug, of electroconvulsive shock (ECS) and of drug-induced alterations in presynaptic 5-HT function on ( 3 H)ketanserin binding to 5-HT-2 receptors in rat brain. The importance of intact 5-HT axons to the up-regulation of 5-HT-2 receptors by ECS was also investigated, and an attempt was made to relate the ECS-induced increase in this receptor to changes in 5-HT presynaptic mechanisms. Twelve days of ECS increased the number of 5-HT-2 receptors in frontal cortex. Neither the IC 50 nor the Hill coefficient of 5-HT in competing for ( 3 H)ketanserin binding sites was altered by ECS. Repeated injections of amitriptyline reduced the number of 5-HT-2 receptors in frontal cortex. Reserpine, administered daily for 12 days, caused a significant increase in 5-HT-2 receptors, but neither daily injections of p-chlorophenylalanine (PCPA) nor lesions of 5-HT axons with 5,7-dihydroxytryptamine (5,7-DHT) affected 5-HT-2 receptors. However, regulation of 5-HT-2 receptors by ECS was dependent on intact 5-HT axons since ECS could not increase the number of 5-HT-2 receptors in rats previously lesioned with 5,7-DHT. Repeated ECS, however, does not appear to affect either the high-affinity uptake of ( 3 H)5-HT or ( 3 H)imipramine binding, two presynaptic markers of 5-HT neuronal function. 5-HT-2 receptors appear to be under complex control. ECS or drug treatments such as reserpine or amitriptyline, which affect several monoamine neurotransmission systems including 5-HT, can alter 5-HT-2 receptors. 28 references, 1 figure, 7 tables

  17. Insulin-like growth factor-II receptors in cultured rat hepatocytes: regulation by cell density

    International Nuclear Information System (INIS)

    Scott, C.D.; Baxter, R.C.

    1987-01-01

    Insulin-like growth factor-II (IGF-II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate [ 125 I]IGF-II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. IGF-II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. We conclude that rat hepatocytes in primary culture contain specific IGF-II receptors and that both cell surface and intracellular receptors are regulated by cell density

  18. Ghrelin receptor regulates adipose tissue inflammation in aging

    Science.gov (United States)

    Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth ho...

  19. Regulation of HIV receptor expression in cervical epithelial cells by ...

    African Journals Online (AJOL)

    Background. Sexually transmitted infections (STIs) caused by the Gram-negative bacteria Chlamydia trachomatis and Neisseria gonorrhoeae are associated with an increased risk of HIV acquisition in South African women. HIV infection involves binding of the virus to CD4+ receptors on host cells and subsequent binding to ...

  20. The role of adenosine receptor agonists in regulation of hematopoiesis

    Czech Academy of Sciences Publication Activity Database

    Hofer, Michal; Pospíšil, Milan; Weiterová, Lenka; Hoferová, Zuzana

    2011-01-01

    Roč. 16, č. 1 (2011), s. 675-685 ISSN 1420-3049 R&D Projects: GA MO OVBIOFYZ20101; GA ČR(CZ) GA305/08/0158 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : adenosine receptors * hematopoiesis * myelosuppression Subject RIV: BO - Biophysics Impact factor: 2.386, year: 2011

  1. Negative regulation of Toll-like receptor signalling 

    Directory of Open Access Journals (Sweden)

    Halina Antosz

    2013-04-01

    Full Text Available The mechanism of innate immunity is based on the pattern recognition receptors (PRR that recognize molecular patterns associated with pathogens (PAMPs. Among PRR receptors Toll-like receptors (TLR are distinguished. As a result of contact with pathogens, TLRs activate specific intracellular signaling pathways. It happens through proteins such as adaptor molecules, e.g. MyD88, TIRAP, TRIF, TRAM, and IPS-1, which participate in the cascade activation of kinases (IKK, MAP, RIP-1, TBK-1 as well as transcription factors (NF-κB, AP-1 and regulatory factor (IRF3. The result of this activation is the production of active proinflammatory cytokines, chemokines, interferons and enzymes. The PRR pathways are controlled by extra – and intracellular molecules to prevent overexpression of PRR. They include soluble receptors (sTLR, transmembrane proteins (ST2, SIGIRR, RP105, TRAIL-R and intracellular inhibitors (SOCS-1, SOCS-3, sMyD88, TOLLIP, IRAK-M, SARM, A20, β-arrestin, CYLD, SHP. These molecules maintain the balance between activation and inhibition and ensure balancing of the beneficial and adverse effects of antigen recognition.

  2. Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

    Science.gov (United States)

    Yuan, Wei-Qi; Zhang, Rong-Rong; Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-05-24

    Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants.

  3. Ethylene Regulates Levels of Ethylene Receptor/CTR1 Signaling Complexes in Arabidopsis thaliana*

    Science.gov (United States)

    Shakeel, Samina N.; Gao, Zhiyong; Amir, Madiha; Chen, Yi-Feng; Rai, Muneeza Iqbal; Haq, Noor Ul; Schaller, G. Eric

    2015-01-01

    The plant hormone ethylene is perceived by a five-member family of receptors in Arabidopsis thaliana. The receptors function in conjunction with the Raf-like kinase CTR1 to negatively regulate ethylene signal transduction. CTR1 interacts with multiple members of the receptor family based on co-purification analysis, interacting more strongly with receptors containing a receiver domain. Levels of membrane-associated CTR1 vary in response to ethylene, doing so in a post-transcriptional manner that correlates with ethylene-mediated changes in levels of the ethylene receptors ERS1, ERS2, EIN4, and ETR2. Interactions between CTR1 and the receptor ETR1 protect ETR1 from ethylene-induced turnover. Kinetic and dose-response analyses support a model in which two opposing factors control levels of the ethylene receptor/CTR1 complexes. Ethylene stimulates the production of new complexes largely through transcriptional induction of the receptors. However, ethylene also induces turnover of receptors, such that levels of ethylene receptor/CTR1 complexes decrease at higher ethylene concentrations. Implications of this model for ethylene signaling are discussed. PMID:25814663

  4. Internalization and down-regulation of the human epidermal growth factor receptor are regulated by the carboxyl-terminal tyrosines

    DEFF Research Database (Denmark)

    Helin, K; Beguinot, L

    1991-01-01

    with receptors in which 1, 2, or all 3 tyrosines were changed to phenylalanines. The triple point mutant EGF-R, expressed in NIH-3T3, exhibited low autophosphorylation in vivo, low biological and reduced kinase activities. Single and double point mutants were down-regulated, as well as wild type EGF......-R in response to EGF showing a half-life of about 1 h. Degradation of the triple point mutant, however, was impaired and resulted in a half-life of 4 h in the presence of EGF. EGF-dependent down-regulation of surface receptors was decreased in the triple point mutant EGF-R as was internalization and degradation...... of EGF. The specific rate of internalization of the triple point mutant was reduced. By contrast, intracellular processing of ligand previously internalized at 20 degrees C was similar between wild type and mutant receptors. Taken together the data indicate that the delay in degradation observed in cells...

  5. Natural compounds regulate energy metabolism by the modulating the activity of lipid-sensing nuclear receptors.

    Science.gov (United States)

    Goto, Tsuyoshi; Kim, Young-Il; Takahashi, Nobuyuki; Kawada, Teruo

    2013-01-01

    Obesity causes excess fat accumulation in various tissues, most notoriously in the adipose tissue, along with other insulin-responsive organs such as skeletal muscle and the liver, which predisposes an individual to the development of metabolic abnormalities. The molecular mechanisms underlying obesity-induced metabolic abnormalities have not been completely elucidated; however, in recent years, the search for therapies to prevent the development of obesity and obesity-associated metabolic disorders has increased. It is known that several nuclear receptors, when activated by specific ligands, regulate carbohydrate and lipid metabolism at the transcriptional level. The expression of lipid metabolism-related enzymes is directly regulated by the activity of various nuclear receptors via their interaction with specific response elements in promoters of those genes. Many natural compounds act as ligands of nuclear receptors and regulate carbohydrate and lipid metabolism by regulating the activities of these nuclear receptors. In this review, we describe our current knowledge of obesity, the role of lipid-sensing nuclear receptors in energy metabolism, and several examples of food factors that act as agonists or antagonists of nuclear receptors, which may be useful for the management of obesity and the accompanying energy metabolism abnormalities. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Cell-Type-Specific Regulation of the Retinoic Acid Receptor Mediated by the Orphan Nuclear Receptor TLX†

    Science.gov (United States)

    Kobayashi, Mime; Yu, Ruth T.; Yasuda, Kunio; Umesono, Kazuhiko

    2000-01-01

    Malformations in the eye can be caused by either an excess or deficiency of retinoids. An early target gene of the retinoid metabolite, retinoic acid (RA), is that encoding one of its own receptors, the retinoic acid receptor β (RARβ). To better understand the mechanisms underlying this autologous regulation, we characterized the chick RARβ2 promoter. The region surrounding the transcription start site of the avian RARβ2 promoter is over 90% conserved with the corresponding region in mammals and confers strong RA-dependent transactivation in primary cultured embryonic retina cells. This response is selective for RAR but not retinoid X receptor-specific agonists, demonstrating a principal role for RAR(s) in retina cells. Retina cells exhibit a far higher sensitivity to RA than do fibroblasts or osteoblasts, a property we found likely due to expression of the orphan nuclear receptor TLX. Ectopic expression of TLX in fibroblasts resulted in increased sensitivity to RA induction, an effect that is conserved between chick and mammals. We have identified a cis element, the silencing element relieved by TLX (SET), within the RARβ2 promoter region which confers TLX- and RA-dependent transactivation. These results indicate an important role for TLX in autologous regulation of the RARβ gene in the eye. PMID:11073974

  7. Cell-type-specific regulation of the retinoic acid receptor mediated by the orphan nuclear receptor TLX.

    Science.gov (United States)

    Kobayashi, M; Yu, R T; Yasuda, K; Umesono, K

    2000-12-01

    Malformations in the eye can be caused by either an excess or deficiency of retinoids. An early target gene of the retinoid metabolite, retinoic acid (RA), is that encoding one of its own receptors, the retinoic acid receptor beta (RARbeta). To better understand the mechanisms underlying this autologous regulation, we characterized the chick RARbeta2 promoter. The region surrounding the transcription start site of the avian RARbeta2 promoter is over 90% conserved with the corresponding region in mammals and confers strong RA-dependent transactivation in primary cultured embryonic retina cells. This response is selective for RAR but not retinoid X receptor-specific agonists, demonstrating a principal role for RAR(s) in retina cells. Retina cells exhibit a far higher sensitivity to RA than do fibroblasts or osteoblasts, a property we found likely due to expression of the orphan nuclear receptor TLX. Ectopic expression of TLX in fibroblasts resulted in increased sensitivity to RA induction, an effect that is conserved between chick and mammals. We have identified a cis element, the silencing element relieved by TLX (SET), within the RARbeta2 promoter region which confers TLX- and RA-dependent transactivation. These results indicate an important role for TLX in autologous regulation of the RARbeta gene in the eye.

  8. Peroxisome proliferator-activated receptor α agonist-induced down-regulation of hepatic glucocorticoid receptor expression in SD rats

    International Nuclear Information System (INIS)

    Chen Xiang; Li Ming; Sun Weiping; Bi Yan; Cai Mengyin; Liang Hua; Yu Qiuqiong; He Xiaoying; Weng Jianping

    2008-01-01

    It was reported that glucocorticoid production was inhibited by fenofibrate through suppression of type-1 11β-hydroxysteroid dehydrogenase gene expression in liver. The inhibition might be a negative-feedback regulation of glucocorticoid receptor (GR) activity by peroxisome proliferator-activated receptor alpha (PPARα), which is quickly induced by glucocorticoid in the liver. However, it is not clear if GR expression is changed by fenofibrate-induced PPARα activation. In this study, we tested this possibility in the liver of Sprague-Dawley rats. GR expression was reduced by fenofibrate in a time- and does-dependent manner. The inhibition was observed in liver, but not in fat and muscle. The corticosterone level in the blood was increased significantly by fenofibrate. These effects of fenofibrate were abolished by PPARα inhibitor MK886, suggesting that fenofibrate activated through PPARα. In conclusion, inhibition of GR expression may represent a new molecular mechanism for the negative feedback regulation of GR activity by PPARα

  9. PTP1B regulates Eph receptor function and trafficking

    OpenAIRE

    Nievergall, Eva; Janes, Peter W.; Stegmayer, Carolin; Vail, Mary E.; Haj, Fawaz G.; Teng, Shyh Wei; Neel, Benjamin G.; Bastiaens, Philippe I.; Lackmann, Martin

    2010-01-01

    Eph receptors orchestrate cell positioning during normal and oncogenic development. Their function is spatially and temporally controlled by protein tyrosine phosphatases (PTPs), but the underlying mechanisms are unclear and the identity of most regulatory PTPs are unknown. We demonstrate here that PTP1B governs signaling and biological activity of EphA3. Changes in PTP1B expression significantly affect duration and amplitude of EphA3 phosphorylation and biological function, whereas confocal ...

  10. A Cholesterol-Sensitive Regulator of the Androgen Receptor

    Science.gov (United States)

    2010-07-01

    Oncogene (2010) 29, 3745–3747; doi:10.1038/onc.2010.132; published online 3 May 2010 Cholesterol is a sterol that serves as a metabolic precursor to other...bioactive sterols , such as nuclear receptor ligands, and also has a major role in plasma membrane structure. Cholesterol and long- chain...cholesterol synthesis (these drugs are generically termed ‘statins’), have been reported to inhibit cancer incidence or progres- sion in some studies. Although

  11. Regulation of AMPA receptor localization in lipid rafts

    OpenAIRE

    Hou, Qingming; Huang, Yunfei; Amato, Stephen; Snyder, Solomon H.; Huganir, Richard L.; Man, Heng-Ye

    2008-01-01

    Lipid rafts are special microdomains enriched in cholesterol, sphingolipids and certain proteins, and play important roles in a variety of cellular functions including signal transduction and protein trafficking. We report that in cultured cortical and hippocampal neurons the distribution of lipid rafts is development-dependent. Lipid rafts in mature neurons exist on the entire cell-surface and display a high degree of mobility. AMPA receptors co-localize and associate with lipid rafts in the...

  12. Hypocretin/Orexin Regulation of Dopamine Signaling and Cocaine Self-Administration Is Mediated Predominantly by Hypocretin Receptor 1

    OpenAIRE

    Prince, Courtney D.; Rau, Andrew R.; Yorgason, Jordan T.; Espa?a, Rodrigo A.

    2014-01-01

    Extensive evidence suggests that the hypocretins/orexins influence cocaine reinforcement and dopamine signaling via actions at hypocretin receptor 1. By comparison, the involvement of hypocretin receptor 2 in reward and reinforcement processes has received relatively little attention. Thus, although there is some evidence that hypocretin receptor 2 regulates intake of some drugs of abuse, it is currently unclear to what extent hypocretin receptor 2 participates in the regulation of dopamine s...

  13. Regulation of dopamine D2 receptors in a novel cell line (SUP1)

    International Nuclear Information System (INIS)

    Ivins, K.J.; Luedtke, R.R.; Artymyshyn, R.P.; Molinoff, P.B.

    1991-01-01

    A prolactin-secreting cell line, SUP1, has been established from rat pituitary tumor 7315a. In radioligand binding experiments, the D2 receptor antagonist (S)-(-)-3- 125 I iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2- pyrrolidinyl)methyl]benzamide ( 125 I IBZM) labeled a single class of sites in homogenates of SUP1 cells (Kd = 0.6 nM; Bmax = 45 fmol/mg of protein). The sites displayed a pharmacological profile consistent with that of D2 receptors. Inhibition of the binding of 125 I IBZM by dopamine was sensitive to GTP, suggesting that D2 receptors in SUP1 cells are coupled to guanine nucleotide-binding protein(s). In the presence of isobutylmethylxanthine, dopamine decreased the level of cAMP accumulation in SUP1 cells. Dopamine also inhibited prolactin secretion from SUP1 cells. Both the inhibition of cAMP accumulation and the inhibition of prolactin secretion were blocked by D2 receptor antagonists, suggesting that these effects of dopamine were mediated by an interaction with D2 receptors. The regulation of D2 receptors in SUP1 cells by D2 receptor agonists was investigated. Exposure of SUP1 cells to dopamine or to the D2 receptor agonist N-propylnorapomorphine led to increased expression of D2 receptors, with no change in the affinity of the receptors for 125 I IBZM. An increase in the density of D2 receptors in SUP1 cells was evident within 7 hr of exposure to dopamine. Spiroperidol, a D2 receptor antagonist, blocked the effect of dopamine on receptor density. These results suggest that exposure of D2 receptors in SUP1 cells to agonists leads to an up-regulation of D2 receptors. Dopamine retained the ability to inhibit cAMP accumulation in SUP1 cells exposed to dopamine for 24 hr, suggesting that D2 receptors in SUP1 cells are not desensitized by prolonged exposure to agonist

  14. DMPD: Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17667936 Structure, function and regulation of the Toll/IL-1 receptor adaptor prote... (.svg) (.html) (.csml) Show Structure, function and regulation of the Toll/IL-1 receptor adaptor proteins. ...PubmedID 17667936 Title Structure, function and regulation of the Toll/IL-1 recep

  15. Investigating the Regulation of Estrogen Receptor-Mediated Transcription

    National Research Council Canada - National Science Library

    Thackray, Varykina

    2002-01-01

    ...-mediated regulation of specific target genes are still lacking. We have developed an estrogen responsive system in the fruit fly, Drosophila melanogaster in order to explore the functional interactions between ER and other cellular proteins...

  16. Investigating the Regulation of Estrogen Receptor-Mediated Transcription

    National Research Council Canada - National Science Library

    Thackray, Varykina

    2001-01-01

    ...-mediated regulation of specific target genes are still lacking. We have developed an estrogen responsive system in the fruit fly, Drosophila melanogaster in order to explore the functional interactions between ER and other cellular proteins...

  17. Screening and association testing of common coding variation in steroid hormone receptor co-activator and co-repressor genes in relation to breast cancer risk: the Multiethnic Cohort

    Directory of Open Access Journals (Sweden)

    Stallcup Michael R

    2009-01-01

    Full Text Available Abstract Background Only a limited number of studies have performed comprehensive investigations of coding variation in relation to breast cancer risk. Given the established role of estrogens in breast cancer, we hypothesized that coding variation in steroid receptor coactivator and corepressor genes may alter inter-individual response to estrogen and serve as markers of breast cancer risk. Methods We sequenced the coding exons of 17 genes (EP300, CCND1, NME1, NCOA1, NCOA2, NCOA3, SMARCA4, SMARCA2, CARM1, FOXA1, MPG, NCOR1, NCOR2, CALCOCO1, PRMT1, PPARBP and CREBBP suggested to influence transcriptional activation by steroid hormone receptors in a multiethnic panel of women with advanced breast cancer (n = 95: African Americans, Latinos, Japanese, Native Hawaiians and European Americans. Association testing of validated coding variants was conducted in a breast cancer case-control study (1,612 invasive cases and 1,961 controls nested in the Multiethnic Cohort. We used logistic regression to estimate odds ratios for allelic effects in ethnic-pooled analyses as well as in subgroups defined by disease stage and steroid hormone receptor status. We also investigated effect modification by established breast cancer risk factors that are associated with steroid hormone exposure. Results We identified 45 coding variants with frequencies ≥ 1% in any one ethnic group (43 non-synonymous variants. We observed nominally significant positive associations with two coding variants in ethnic-pooled analyses (NCOR2: His52Arg, OR = 1.79; 95% CI, 1.05–3.05; CALCOCO1: Arg12His, OR = 2.29; 95% CI, 1.00–5.26. A small number of variants were associated with risk in disease subgroup analyses and we observed no strong evidence of effect modification by breast cancer risk factors. Based on the large number of statistical tests conducted in this study, the nominally significant associations that we observed may be due to chance, and will need to be confirmed in other

  18. Screening and association testing of common coding variation in steroid hormone receptor co-activator and co-repressor genes in relation to breast cancer risk: the Multiethnic Cohort

    International Nuclear Information System (INIS)

    Haiman, Christopher A; Stallcup, Michael R; Greene, Geoffrey L; Press, Michael F; Garcia, Rachel R; Hsu, Chris; Xia, Lucy; Ha, Helen; Sheng, Xin; Le Marchand, Loic; Kolonel, Laurence N; Henderson, Brian E

    2009-01-01

    Only a limited number of studies have performed comprehensive investigations of coding variation in relation to breast cancer risk. Given the established role of estrogens in breast cancer, we hypothesized that coding variation in steroid receptor coactivator and corepressor genes may alter inter-individual response to estrogen and serve as markers of breast cancer risk. We sequenced the coding exons of 17 genes (EP300, CCND1, NME1, NCOA1, NCOA2, NCOA3, SMARCA4, SMARCA2, CARM1, FOXA1, MPG, NCOR1, NCOR2, CALCOCO1, PRMT1, PPARBP and CREBBP) suggested to influence transcriptional activation by steroid hormone receptors in a multiethnic panel of women with advanced breast cancer (n = 95): African Americans, Latinos, Japanese, Native Hawaiians and European Americans. Association testing of validated coding variants was conducted in a breast cancer case-control study (1,612 invasive cases and 1,961 controls) nested in the Multiethnic Cohort. We used logistic regression to estimate odds ratios for allelic effects in ethnic-pooled analyses as well as in subgroups defined by disease stage and steroid hormone receptor status. We also investigated effect modification by established breast cancer risk factors that are associated with steroid hormone exposure. We identified 45 coding variants with frequencies ≥ 1% in any one ethnic group (43 non-synonymous variants). We observed nominally significant positive associations with two coding variants in ethnic-pooled analyses (NCOR2: His52Arg, OR = 1.79; 95% CI, 1.05–3.05; CALCOCO1: Arg12His, OR = 2.29; 95% CI, 1.00–5.26). A small number of variants were associated with risk in disease subgroup analyses and we observed no strong evidence of effect modification by breast cancer risk factors. Based on the large number of statistical tests conducted in this study, the nominally significant associations that we observed may be due to chance, and will need to be confirmed in other studies. Our findings suggest that common coding

  19. Loss of steroid hormone receptors is common in malignant pleural and peritoneal effusions of breast cancer patients treated with endocrine therapy

    NARCIS (Netherlands)

    Schrijver, Willemijne A.M.E.; Schuurman, Karianne G.; Van Rossum, Annelot; Peeters, Ton; Hoeve, Natalie Ter; Zwart, Wilbert; van Diest, Paul J.; Moelans, Cathy B.; Linn, Sabine

    2017-01-01

    Discordance in estrogen receptor alpha (ERa), progesterone receptor (PR), androgen receptor (AR) and human epidermal growth factor receptor 2 (HER2) status between primary breast cancers and solid distant metastases ("conversion") has been reported previously. Even though metastatic spread to the

  20. Safety and tolerability of the novel non-steroidal mineralocorticoid receptor antagonist BAY 94-8862 in patients with chronic heart failure and mild or moderate chronic kidney disease

    DEFF Research Database (Denmark)

    Pitt, Bertram; Kober, Lars; Ponikowski, Piotr

    2013-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve outcomes in patients with heart failure and reduced left ventricular ejection fraction (HFrEF), but their use is limited by hyperkalaemia and/or worsening renal function (WRF). BAY 94-8862 is a highly selective and strongly potent non-steroida......Mineralocorticoid receptor antagonists (MRAs) improve outcomes in patients with heart failure and reduced left ventricular ejection fraction (HFrEF), but their use is limited by hyperkalaemia and/or worsening renal function (WRF). BAY 94-8862 is a highly selective and strongly potent non......-steroidal MRA. We investigated its safety and tolerability in patients with HFrEF associated with mild or moderate chronic kidney disease (CKD)....

  1. Eph receptor interclass cooperation is required for the regulation of cell proliferation

    International Nuclear Information System (INIS)

    Jurek, Aleksandra; Genander, Maria; Kundu, Parag; Catchpole, Timothy; He, Xiao; Strååt, Klas; Sabelström, Hanna; Xu, Nan-Jie; Pettersson, Sven; Henkemeyer, Mark; Frisén, Jonas

    2016-01-01

    Cancer often arises by the constitutive activation of mitogenic pathways by mutations in stem cells. Eph receptors are unusual in that although they regulate the proliferation of stem/progenitor cells in many adult organs, they typically fail to transform cells. Multiple ephrins and Eph receptors are often co-expressed and are thought to be redundant, but we here describe an unexpected dichotomy with two homologous ligands, ephrin-B1 and ephrin-B2, regulating specifically migration or proliferation in the intestinal stem cell niche. We demonstrate that the combined activity of two different coexpressed Eph receptors of the A and B class assembled into common signaling clusters in response to ephrin-B2 is required for mitogenic signaling. The requirement of two different Eph receptors to convey mitogenic signals identifies a new type of cooperation within this receptor family and helps explain why constitutive activation of a single receptor fails to transform cells. - Highlights: • We demonstrate that ephrin-B1 and ephrin-B2 have largely non-overlapping functions in the intestinal stem cell niche. • Ephrin-B1 regulates cell positioning and ephrin-B2 regulates cell proliferation in the intestinal stem cell niche. • EphA4/B2 receptor cooperation in response to ephrin-B2 binding is obligatory to convey mitogenic signals in the intestine. • EphA4 facilitates EphB2 phosphorylation in response to ephrin-B2 in SW480 adenocarcinoma cells. • Ephrin-B1 and ephrin-B2 induce phosphorylation and degradation of the EphB2 receptor with different kinetics.

  2. Eph receptor interclass cooperation is required for the regulation of cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Jurek, Aleksandra; Genander, Maria [Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77 Stockholm (Sweden); Kundu, Parag [Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, SE-171 77 Stockholm (Sweden); Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Lee Kong Chian School of Medicine, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Catchpole, Timothy [Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas TX 75390 (United States); He, Xiao; Strååt, Klas; Sabelström, Hanna [Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77 Stockholm (Sweden); Xu, Nan-Jie [Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas TX 75390 (United States); Pettersson, Sven [Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, SE-171 77 Stockholm (Sweden); Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Lee Kong Chian School of Medicine, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); The National Cancer Centre, Singapore General Hospital (Singapore); Henkemeyer, Mark [Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas TX 75390 (United States); Frisén, Jonas, E-mail: jonas.frisen@ki.se [Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77 Stockholm (Sweden)

    2016-10-15

    Cancer often arises by the constitutive activation of mitogenic pathways by mutations in stem cells. Eph receptors are unusual in that although they regulate the proliferation of stem/progenitor cells in many adult organs, they typically fail to transform cells. Multiple ephrins and Eph receptors are often co-expressed and are thought to be redundant, but we here describe an unexpected dichotomy with two homologous ligands, ephrin-B1 and ephrin-B2, regulating specifically migration or proliferation in the intestinal stem cell niche. We demonstrate that the combined activity of two different coexpressed Eph receptors of the A and B class assembled into common signaling clusters in response to ephrin-B2 is required for mitogenic signaling. The requirement of two different Eph receptors to convey mitogenic signals identifies a new type of cooperation within this receptor family and helps explain why constitutive activation of a single receptor fails to transform cells. - Highlights: • We demonstrate that ephrin-B1 and ephrin-B2 have largely non-overlapping functions in the intestinal stem cell niche. • Ephrin-B1 regulates cell positioning and ephrin-B2 regulates cell proliferation in the intestinal stem cell niche. • EphA4/B2 receptor cooperation in response to ephrin-B2 binding is obligatory to convey mitogenic signals in the intestine. • EphA4 facilitates EphB2 phosphorylation in response to ephrin-B2 in SW480 adenocarcinoma cells. • Ephrin-B1 and ephrin-B2 induce phosphorylation and degradation of the EphB2 receptor with different kinetics.

  3. Allosteric regulation by oleamide of the binding properties of 5-hydroxytryptamine7 receptors.

    Science.gov (United States)

    Hedlund, P B; Carson, M J; Sutcliffe, J G; Thomas, E A

    1999-12-01

    Oleamide belongs to a family of amidated lipids with diverse biological activities, including sleep induction and signaling modulation of several 5-hydroxytryptamine (5-HT) receptor subtypes, including 5-HT1A, 5-HT2A/2C, and 5-HT7. The 5-HT7 receptor, predominantly localized in the hypothalamus, hippocampus, and frontal cortex, stimulates cyclic AMP formation and is thought to be involved in the regulation of sleep-wake cycles. Recently, it was proposed that oleamide acts at an allosteric site on the 5-HT7 receptor to regulate cyclic AMP formation. We have further investigated the interaction between oleamide and 5-HT7 receptors by performing radioligand binding assays with HeLa cells transfected with the 5-HT7 receptor. Methiothepin, clozapine, and 5-HT all displaced specific [3H]5-HT (100 nM) binding, with pK(D) values of 7.55, 7.85, and 8.39, respectively. Oleamide also displaced [3H]5-HT binding, but the maximum inhibition was only 40% of the binding. Taking allosteric (see below) cooperativity into account, a K(D) of 2.69 nM was calculated for oleamide. In saturation binding experiments, oleamide caused a 3-fold decrease in the affinity of [3H]5-HT for the 5-HT7 receptor, without affecting the number of binding sites. A Schild analysis showed that the induced shift in affinity of [3H]5-HT reached a plateau, unlike that of a competitive inhibitor, illustrating the allosteric nature of the interaction between oleamide and the 5-HT7 receptor. Oleic acid, the product of oleamide hydrolysis, had a similar effect on [3H]5-HT binding, whereas structural analogs of oleamide, trans-9,10-octadecenamide, cis-8,9-octadecenamide, and erucamide, did not alter [3H]5-HT binding significantly. The findings support the hypothesis that oleamide acts via an allosteric site on the 5-HT7 receptor regulating receptor affinity.

  4. Steroid radioimmunoassays

    International Nuclear Information System (INIS)

    Shinde, Y.; Hacker, R.R.; Ntunde, B.; Smith, V.G.

    1981-01-01

    An estrogen radioimmunoassay was used to study the problem of blanks in steroid assays. Negligible binding (1.5 percent) in the non-antibody tubes prevailed throughout the study. The assay was validated using accepted procedures. Both water and solvent blanks had estrogen concentrations of 7-9 pg/tube. However, neither water nor solvent blanks showed a dose-related response, indicating that they were 'real' blanks. Exogenous estradiol, when added to water and solvent in quantities less than the estimated blank, was not quantitatively recovered. However, exogenous estradiol added to the water solvent in quantities greater than the blank estimate was quantitatively recovered. The sensitivity of the reference standard curve was 6-10 pg/tube, approximately the same as the blank estimate. These results indicated that the estimates of water and solvent blanks were measures of the assay sensitivity. In such circumstances, it is suggested that blank estimates should not be subtracted from sample values. If the blank estimates are high, attention should be directed towards improving the sensitivity of the assay

  5. Regulation versus modulation in GnRH receptor function

    International Nuclear Information System (INIS)

    Zolman, J.C.; Theodoropoulos, T.J.

    1985-01-01

    Serum luteinizing hormone (LH) concentration after exposure to gonadotropin-releasing hormone (GnRH) indicates that an instantaneous increase occurs in the rate of release of LH directly from the anterior pituitary, as measured dynamically during superfusion in vitro. On the other hand, estradiol-17 beta (E2) alone shows no such instantaneous effect on LH release rate (at least for the first four hours), in either physiologic or pharmacologic concentrations. At the same time, brief (ten to 30 minute) exposure of isolated anterior pituitary plasma membranes to physiologic concentrations of E2 significantly alters the binding of a fully biologically active 125 I-GnRH to its plasma membrane receptor protein. In order to characterize the effect of E2 on GnRH binding further, dispersed bovine anterior pituitary cells were preincubated for six hours in the presence or absence of physiologic concentrations of E2 (10(-10)M). Following preincubation in the presence of E2, the cell suspension was incubated for 30 minutes with physiologic concentrations (5 x 10(-11) - 5 x 10(-10)M) of a fully biologically active 125 I-GnRH. The treatment, at least, doubled the number of biologically important high affinity GnRH binding sites (Kd's . 7.5 x -10(-11) - 4.5 x 10(-10)M), and changed the binding capacity of some of the binding sites up to three fold, which altered the cooperativity of GnRH-receptor interaction. Thus, the interaction of E2 with GnRH at the level of GnRH receptor is mandatory for the short-term pituitary effect of E2 on LH release in vitro and in vivo

  6. Interleukin-6 receptor expression in contracting human skeletal muscle: regulating role of IL-6

    DEFF Research Database (Denmark)

    Keller, Pernille; Penkowa, Milena; Keller, Charlotte

    2005-01-01

    Contracting muscle fibers produce and release IL-6, and plasma levels of this cytokine are markedly elevated in response to physical exercise. We recently showed autocrine regulation of IL-6 in human skeletal muscle in vivo and hypothesized that this may involve up-regulation of the IL-6 receptor....... Infusion of rhIL-6 to humans had no effect on the mRNA level of the IL-6 receptor, whereas there was an increase at the protein level. IL-6 receptor mRNA increased similarly in muscle of both IL-6 KO mice and wild-type mice in response to exercise. In conclusion, exercise increases IL-6 receptor production....... Therefore, we investigated IL-6 receptor regulation in response to exercise and IL-6 infusion in humans. Furthermore, using IL-6-deficient mice, we investigated the role of IL-6 in the IL-6 receptor response to exercise. Human skeletal muscle biopsies were obtained in relation to: 3 h of bicycle exercise...

  7. Phytomelatonin receptor PMTR1-mediated signaling regulates stomatal closure in Arabidopsis thaliana.

    Science.gov (United States)

    Wei, Jian; Li, Dong-Xu; Zhang, Jia-Rong; Shan, Chi; Rengel, Zed; Song, Zhong-Bang; Chen, Qi

    2018-04-27

    Melatonin has been detected in plants in 1995; however, the function and signaling pathway of this putative phytohormone are largely undetermined due to a lack of knowledge about its receptor. Here, we discovered the first phytomelatonin receptor (CAND2/PMTR1) in Arabidopsis thaliana and found that melatonin governs the receptor-dependent stomatal closure. The application of melatonin induced stomatal closure through the heterotrimeric G protein α subunit-regulated H 2 O 2 and Ca 2+ signals. The Arabidopsis mutant lines lacking AtCand2 that encodes a candidate G protein-coupled receptor were insensitive to melatonin-induced stomatal closure. Accordingly, the melatonin-induced H 2 O 2 production and Ca 2+ influx were completely abolished in cand2. CAND2 is a membrane protein that interacts with GPA1 and the expression of AtCand2 was tightly regulated by melatonin in various organs and guard cells. CAND2 showed saturable and specific 125 I-melatonin binding, with apparent K d (dissociation constant) of 0.73 ± 0.10 nmol/L (r 2  = .99), demonstrating this protein is a phytomelatonin receptor (PMTR1). Our results suggest that the phytomelatonin regulation of stomatal closure is dependent on its receptor CAND2/PMTR1-mediated H 2 O 2 and Ca 2+ signaling transduction cascade. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. AMPA receptor mediated excitotoxicity in neocortical neurons is developmentally regulated and dependent upon receptor desensitization

    DEFF Research Database (Denmark)

    Jensen, J B; Schousboe, A; Pickering, D S

    1998-01-01

    with a fast and rapidly desensitizing response, this could explain the relatively low toxicity produced by 500 microM AMPA. This was investigated by blocking AMPA receptor desensitization with cyclothiazide. Using a lower concentration (25 microM) of AMPA, addition of 50 microM cyclothiazide increased...... the AMPA induced excitotoxicity in cultured cortical neurons at all DIV except for DIV 2. This combination of AMPA + cyclothiazide yielded 77% cell death for DIV 12 cultures. In contrast to the results observed with 500 microM AMPA, the neurotoxicity mediated directly by AMPA receptors when desensitization...

  9. Xenobiotic Receptor-Mediated Regulation of Intestinal Barrier Function and Innate Immunity

    Directory of Open Access Journals (Sweden)

    Harmit S. Ranhotra

    2016-07-01

    Full Text Available The molecular basis for the regulation of the intestinal barrier is a very fertile research area. A growing body of knowledge supports the targeting of various components of intestinal barrier function as means to treat a variety of diseases, including the inflammatory bowel diseases. Herein, we will summarize the current state of knowledge of key xenobiotic receptor regulators of barrier function, highlighting recent advances, such that the field and its future are succinctly reviewed. We posit that these receptors confer an additional dimension of host-microbe interaction in the gut, by sensing and responding to metabolites released from the symbiotic microbiota, in innate immunity and also in host drug metabolism. The scientific evidence for involvement of the receptors and its molecular basis for the control of barrier function and innate immunity regulation would serve as a rationale towards development of non-toxic probes and ligands as drugs.

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

    Science.gov (United States)

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

    2017-11-01

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

  11. Toll-like receptor 3 signalling up-regulates expression of the HIV co-receptor G-protein coupled receptor 15 on human CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Miriam Kiene

    Full Text Available BACKGROUND: Many HIV-2 and SIV isolates, as well as some HIV-1 strains, can use the orphan 7-transmembrane receptor GPR15 as co-receptor for efficient entry into host cells. GPR15 is expressed on central memory and effector memory CD4(+ T cells in healthy individuals and a subset of these cells is susceptible to HIV-1 and SIV infection. However, it has not been determined whether GPR15 expression is altered in the context of HIV-1 infection. RESULTS: Here, we show that GPR15 expression in CD4(+ T cells is markedly up-regulated in some HIV-1 infected individuals compared to the rest of the infected patients and to healthy controls. Infection of the PM1 T cell line with primary HIV-1 isolates was found to up-regulate GPR15 expression on the infected cells, indicating that viral components can induce GPR15 expression. Up-regulation of GPR15 expression on CD4(+ T cells was induced by activation of Toll-like receptor 3 signalling via TIR-domain-containing adapter-inducing interferon-β (TRIF and was more prominent on gut-homing compared to lymph node-homing CD4(+ T cells. CONCLUSION: These results suggest that infection-induced up-regulation of GPR15 expression could increase susceptibility of CD4(+ T cells to HIV infection and target cell availability in the gut in some infected individuals.

  12. Ghrelin receptor regulates adipose tissue inflammation in aging.

    Science.gov (United States)

    Lin, Ligen; Lee, Jong Han; Buras, Eric D; Yu, Kaijiang; Wang, Ruitao; Smith, C Wayne; Wu, Huaizhu; Sheikh-Hamad, David; Sun, Yuxiang

    2016-01-01

    Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), increases in adipose tissues during aging, and old Ghsr(-/-) mice exhibit a lean and insulin-sensitive phenotype. Macrophages are major mediators of adipose tissue inflammation, which consist of pro-inflammatory M1 and anti-inflammatory M2 subtypes. Here, we show that in aged mice, GHS-R ablation promotes macrophage phenotypical shift toward anti-inflammatory M2. Old Ghsrp(-/-) mice have reduced macrophage infiltration, M1/M2 ratio, and pro-inflammatory cytokine expression in white and brown adipose tissues. We also found that peritoneal macrophages of old Ghsrp(-/-) mice produce higher norepinephrine, which is in line with increased alternatively-activated M2 macrophages. Our data further reveal that GHS-R has cell-autonomous effects in macrophages, and GHS-R antagonist suppresses lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Collectively, our studies demonstrate that ghrelin signaling has an important role in macrophage polarization and adipose tissue inflammation during aging. GHS-R antagonists may serve as a novel and effective therapeutic option for age-associated adipose tissue inflammation and insulin resistance.

  13. Adipocyte glucocorticoid receptor is important in lipolysis and insulin resistance due to exogenous steroids, but not insulin resistance caused by high fat feeding

    Directory of Open Access Journals (Sweden)

    Yachen Shen

    2017-10-01

    Conclusions: Our data suggest that the GR plays a role in normal adipose physiology via effects on lipolysis and mediates at least some of the adverse effects of exogenous steroids on metabolic function. The data also indicate that intra-adipocyte GR plays less of a role than previously believed in the local and systemic pathology associated with overnutrition.

  14. Modification of behavioral effects of drugs in mice by neuroactive steroids

    NARCIS (Netherlands)

    Ungard, JT; Beekman, M; Gasior, M; Carter, RB; Dijkstra, D; Witkin, JM

    Rationale: Neuroactive steroids represent a novel class of potential therapeutic agents (epilepsy, anxiety, migraine, drug dependence) thought to act through positive allosteric modulation of the GABA(A) receptor A synthetically derived neuroactive steroid, ganaxolone (3 alpha-hydroxy-3

  15. Regulation of ion transport via apical purinergic receptors in intact rabbit airway epithelium

    DEFF Research Database (Denmark)

    Poulsen, Asser Nyander; Klausen, Thomas Levin; Pedersen, Peter Steen

    2005-01-01

    and unidirectional Cl- fluxes decreased significantly. The results suggest that nucleotides released to the airway surface liquid exert an autocrine regulation of epithelial NaCl absorption mainly by inhibiting the amiloride-sensitive epithelial Na+ channel (ENaC) and paracellular anion conductance via a P2Y......We investigated purinergic receptors involved in ion transport regulation in the intact rabbit nasal airway epithelium. Stimulation of apical membrane P2Y receptors with ATP or UTP (200 microM) induced transient increases in short-circuit current (Isc) of 13 and 6% followed by sustained inhibitions...

  16. Quantitative Impact of Plasma Clearance and Down-regulation on GLP-1 Receptor Molecular Imaging.

    Science.gov (United States)

    Zhang, Liang; Thurber, Greg M

    2016-02-01

    Quantitative molecular imaging of beta cell mass (BCM) would enable early detection and treatment monitoring of type 1 diabetes. The glucagon-like peptide-1 (GLP-1) receptor is an attractive target due to its beta cell specificity and cell surface location. We quantitatively investigated the impact of plasma clearance and receptor internalization on targeting efficiency in healthy B6 mice. Four exenatide-based probes were synthesized that varied in molecular weight, binding affinity, and plasma clearance. The GLP-1 receptor internalization rate and in vivo receptor expression were quantified. Receptor internalization (54,000 receptors/cell in vivo) decreased significantly within minutes, reducing the benefit of a slower-clearing agent. The multimers and albumin binding probes had higher kidney and liver uptake, respectively. Slow plasma clearance is beneficial for GLP-1 receptor peptide therapeutics. However, for exendin-based imaging of islets, down-regulation of the GLP-1 receptor and non-specific background uptake result in a higher target-to-background ratio for fast-clearing agents.

  17. Co-regulation of a large and rapidly evolving repertoire of odorant receptor genes

    Directory of Open Access Journals (Sweden)

    Lane Robert P

    2007-09-01

    Full Text Available Abstract The olfactory system meets niche- and species-specific demands by an accelerated evolution of its odorant receptor repertoires. In this review, we describe evolutionary processes that have shaped olfactory and vomeronasal receptor gene families in vertebrate genomes. We emphasize three important periods in the evolution of the olfactory system evident by comparative genomics: the adaptation to land in amphibian ancestors, the decline of olfaction in primates, and the delineation of putative pheromone receptors concurrent with rodent speciation. The rapid evolution of odorant receptor genes, the sheer size of the repertoire, as well as their wide distribution in the genome, presents a developmental challenge: how are these ever-changing odorant receptor repertoires coordinated within the olfactory system? A central organizing principle in olfaction is the specialization of sensory neurons resulting from each sensory neuron expressing only ~one odorant receptor allele. In this review, we also discuss this mutually exclusive expression of odorant receptor genes. We have considered several models to account for co-regulation of odorant receptor repertoires, as well as discussed a new hypothesis that invokes important epigenetic properties of the system.

  18. Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis.

    Science.gov (United States)

    Berglund, Eric D; Liu, Chen; Sohn, Jong-Woo; Liu, Tiemin; Kim, Mi Hwa; Lee, Charlotte E; Vianna, Claudia R; Williams, Kevin W; Xu, Yong; Elmquist, Joel K

    2013-12-01

    Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor agonists on energy and glucose homeostasis are unknown. Here, we show that mice lacking serotonin 2C receptors (Htr2c) specifically in pro-opiomelanocortin (POMC) neurons had normal body weight but developed glucoregulatory defects including hyperinsulinemia, hyperglucagonemia, hyperglycemia, and insulin resistance. Moreover, these mice did not show anorectic responses to serotonergic agents that suppress appetite and developed hyperphagia and obesity when they were fed a high-fat/high-sugar diet. A requirement of serotonin 2C receptors in POMC neurons for the maintenance of normal energy and glucose homeostasis was further demonstrated when Htr2c loss was induced in POMC neurons in adult mice using a tamoxifen-inducible POMC-cre system. These data demonstrate that serotonin 2C receptor-expressing POMC neurons are required to control energy and glucose homeostasis and implicate POMC neurons as the target for the effect of serotonin 2C receptor agonists on weight-loss induction and improved glycemic control.

  19. Signal transduction by VEGF receptors in regulation of angiogenesis and lymphangiogenesis

    International Nuclear Information System (INIS)

    Shibuya, Masabumi; Claesson-Welsh, Lena

    2006-01-01

    The VEGF/VPF (vascular endothelial growth factor/vascular permeability factor) ligands and receptors are crucial regulators of vasculogenesis, angiogenesis, lymphangiogenesis and vascular permeability in vertebrates. VEGF-A, the prototype VEGF ligand, binds and activates two tyrosine kinase receptors: VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). VEGFR1, which occurs in transmembrane and soluble forms, negatively regulates vasculogenesis and angiogenesis during early embryogenesis, but it also acts as a positive regulator of angiogenesis and inflammatory responses, playing a role in several human diseases such as rheumatoid arthritis and cancer. The soluble VEGFR1 is overexpressed in placenta in preeclampsia patients. VEGFR2 has critical functions in physiological and pathological angiogenesis through distinct signal transduction pathways regulating proliferation and migration of endothelial cells. VEGFR3, a receptor for the lymphatic growth factors VEGF-C and VEGF-D, but not for VEGF-A, regulates vascular and lymphatic endothelial cell function during embryogenesis. Loss-of-function variants of VEGFR3 have been identified in lymphedema. Formation of tumor lymphatics may be stimulated by tumor-produced VEGF-C, allowing increased spread of tumor metastases through the lymphatics. Mapping the signaling system of these important receptors may provide the knowledge necessary to suppress specific signaling pathways in major human diseases

  20. Hormonal regulation of AMPA receptor trafficking and memory formation

    Directory of Open Access Journals (Sweden)

    Harmen J Krugers

    2009-10-01

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

  1. A pair of pharyngeal gustatory receptor neurons regulates caffeine-dependent ingestion in Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Jaekyun Choi

    2016-07-01

    Full Text Available The sense of taste is an essential chemosensory modality that enables animals to identify appropriate food sources and control feeding behavior. In particular, the recognition of bitter taste prevents animals from feeding on harmful substances. Feeding is a complex behavior comprised of multiple steps, and food quality is continuously assessed. We here examined the role of pharyngeal gustatory organs in ingestion behavior. As a first step, we constructed a gustatory receptor-to-neuron map of the larval pharyngeal sense organs, and examined corresponding gustatory receptor neuron projections in the larval brain. Out of 22 candidate bitter compounds, we found 14 bitter compounds that elicit inhibition of ingestion in a dose-dependent manner. We provide evidence that certain pharyngeal gustatory receptor neurons are necessary and sufficient for the ingestion response of larvae to caffeine. Additionally, we show that a specific pair of pharyngeal gustatory receptor neurons, DP1, responds to caffeine by calcium imaging. In this study we show that a specific pair of gustatory receptor neurons in the pharyngeal sense organs coordinates caffeine sensing with regulation of behavioral responses such as ingestion. Our results indicate that in Drosophila larvae, the pharyngeal gustatory receptor neurons have a major role in sensing food palatability to regulate ingestion behavior. The pharyngeal sense organs are prime candidates to influence ingestion due to their position in the pharynx, and they may act as first level sensors of ingested food.

  2. Regulation of steroid 5-{alpha} reductase type 2 (Srd5a2) by sterol regulatory element binding proteins and statin

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young-Kyo [Department of Molecular Biology and Biochemistry, 3244 McGaugh Hall, University of California, UC Irvine, Irvine, CA 92697-3900 (United States); Zhu, Bing [Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0144 (United States); Jeon, Tae-Il [Department of Molecular Biology and Biochemistry, 3244 McGaugh Hall, University of California, UC Irvine, Irvine, CA 92697-3900 (United States); Osborne, Timothy F., E-mail: tfosborn@uci.edu [Department of Molecular Biology and Biochemistry, 3244 McGaugh Hall, University of California, UC Irvine, Irvine, CA 92697-3900 (United States)

    2009-11-01

    In this study, we show that sterol regulatory element binding proteins (SREBPs) regulate expression of Srd5a2, an enzyme that catalyzes the irreversible conversion of testosterone to dihydroxytestosterone in the male reproductive tract and is highly expressed in androgen-sensitive tissues such as the prostate and skin. We show that Srd5a2 is induced in livers and prostate from mice fed a chow diet supplemented with lovastatin plus ezitimibe (L/E), which increases the activity of nuclear SREBP-2. The three fold increase in Srd5a2 mRNA mediated by L/E treatment was accompanied by the induction of SREBP-2 binding to the Srd5a2 promoter detected by a ChIP-chip assay in liver. We identified a SREBP-2 responsive region within the first 300 upstream bases of the mouse Srd5a2 promoter by co-transfection assays which contain a site that bound SREBP-2 in vitro by an EMSA. Srd5a2 protein was also induced in cells over-expressing SREBP-2 in culture. The induction of Srd5a2 through SREBP-2 provides a mechanistic explanation for why even though statin therapy is effective in reducing cholesterol levels in treating hypercholesterolemia it does not compromise androgen production in clinical studies.

  3. Regulation of steroid 5-α reductase type 2 (Srd5a2) by sterol regulatory element binding proteins and statin

    International Nuclear Information System (INIS)

    Seo, Young-Kyo; Zhu, Bing; Jeon, Tae-Il; Osborne, Timothy F.

    2009-01-01

    In this study, we show that sterol regulatory element binding proteins (SREBPs) regulate expression of Srd5a2, an enzyme that catalyzes the irreversible conversion of testosterone to dihydroxytestosterone in the male reproductive tract and is highly expressed in androgen-sensitive tissues such as the prostate and skin. We show that Srd5a2 is induced in livers and prostate from mice fed a chow diet supplemented with lovastatin plus ezitimibe (L/E), which increases the activity of nuclear SREBP-2. The three fold increase in Srd5a2 mRNA mediated by L/E treatment was accompanied by the induction of SREBP-2 binding to the Srd5a2 promoter detected by a ChIP-chip assay in liver. We identified a SREBP-2 responsive region within the first 300 upstream bases of the mouse Srd5a2 promoter by co-transfection assays which contain a site that bound SREBP-2 in vitro by an EMSA. Srd5a2 protein was also induced in cells over-expressing SREBP-2 in culture. The induction of Srd5a2 through SREBP-2 provides a mechanistic explanation for why even though statin therapy is effective in reducing cholesterol levels in treating hypercholesterolemia it does not compromise androgen production in clinical studies.

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

    Science.gov (United States)

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

    2017-08-15

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

  5. TAM receptors affect adult brain neurogenesis by negative regulation of microglial cell activation.

    Science.gov (United States)

    Ji, Rui; Tian, Shifu; Lu, Helen J; Lu, Qingjun; Zheng, Yan; Wang, Xiaomin; Ding, Jixiang; Li, Qiutang; Lu, Qingxian

    2013-12-15

    TAM tyrosine kinases play multiple functional roles, including regulation of the target genes important in homeostatic regulation of cytokine receptors or TLR-mediated signal transduction pathways. In this study, we show that TAM receptors affect adult hippocampal neurogenesis and loss of TAM receptors impairs hippocampal neurogenesis, largely attributed to exaggerated inflammatory responses by microglia characterized by increased MAPK and NF-κB activation and elevated production of proinflammatory cytokines that are detrimental to neuron stem cell proliferation and neuronal differentiation. Injection of LPS causes even more severe inhibition of BrdU incorporation in the Tyro3(-/-)Axl(-/-)Mertk(-/-) triple-knockout (TKO) brains, consistent with the LPS-elicited enhanced expression of proinflammatory mediators, for example, IL-1β, IL-6, TNF-α, and inducible NO synthase, and this effect is antagonized by coinjection of the anti-inflammatory drug indomethacin in wild-type but not TKO brains. Conditioned medium from TKO microglia cultures inhibits neuron stem cell proliferation and neuronal differentiation. IL-6 knockout in Axl(-/-)Mertk(-/-) double-knockout mice overcomes the inflammatory inhibition of neurogenesis, suggesting that IL-6 is a major downstream neurotoxic mediator under homeostatic regulation by TAM receptors in microglia. Additionally, autonomous trophic function of the TAM receptors on the proliferating neuronal progenitors may also promote progenitor differentiation into immature neurons.

  6. Up-regulated dipeptidyl-peptidase IV (CD26) on monocytes was unaffected by effective DMARD treatment in early steroid and DMARD-naive rheumatoid arthritis

    DEFF Research Database (Denmark)

    Ellingsen, Torkell Juulsgaad; Hansen, I; Thorsen, J

    2012-01-01

    To study the CD26 density on monocytes and CD4+ T-lymphocytes in steroid and DMARD-naïve, early rheumatoid arthritis (RA) patients and to analyse for correlations with disease activity, including long-term radiographic progression.......To study the CD26 density on monocytes and CD4+ T-lymphocytes in steroid and DMARD-naïve, early rheumatoid arthritis (RA) patients and to analyse for correlations with disease activity, including long-term radiographic progression....

  7. Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor

    International Nuclear Information System (INIS)

    Yan Zhencheng; Liu Daoyan; Zhang Lili; Shen Chenyi; Ma Qunli; Cao Tingbing; Wang Lijuan; Nie Hai; Zidek, Walter; Tepel, Martin; Zhu Zhiming

    2007-01-01

    Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-δ (PPAR-δ)-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p < 0.05). Adipocyte hypertrophy induced by high-fat diet was accompanied by increased CB1 expression in adipose tissue, whereas exercise significantly reduced CB1 expression (each p < 0.05). CB1 receptor expression and adipocyte differentiation were directly regulated by PPAR-δ. Adipocyte hypertrophy induced by high-fat diet was accompanied by reduced PPAR-δ. Furthermore, selective silencing of PPAR-δ by RNA interference in 3T3-L1-preadipocyte cells significantly increased CB1 expression from 1.00 ± 0.06 (n = 3) to 1.91 ± 0.06 (n = 3; p < 0.01) and increased adipocyte differentiation, whereas adenovirus-mediated overexpression of PPAR-δ significantly reduced CB1 expression to 0.39 ± 0.03 (n = 3; p < 0.01) and reduced adipocyte differentiation. In the presence of the CB1 antagonist rimonabant adipocyte differentiation in stimulated 3T3 L1 preadipocyte cells was significantly reduced. The study indicates that high-fat diet-induced hypertrophy of adipocytes is associated with increased CB1 receptor expression which is directly regulated by PPAR-δ. Both CB1 and PPAR-δ are intimately involved in therapeutic interventions against a most important cardiovascular risk factor

  8. Up-regulation of Toll-like receptors 2, 3 and 4 in allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Uddman Rolf

    2005-09-01

    Full Text Available Abstract Background Toll-like receptors enable the host to recognize a large number of pathogen-associated molecular patterns such as bacterial lipopolysaccharide, viral RNA, CpG-containing DNA and flagellin. Toll-like receptors have also been shown to play a pivotal role in both innate and adaptive immune responses. The role of Toll-like receptors as a primary part of our microbe defense system has been shown in several studies, but their possible function as mediators in allergy and asthma remains to be established. The present study was designed to examine the expression of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with intermittent allergic rhinitis, focusing on changes induced by exposure to pollen. Methods 27 healthy controls and 42 patients with seasonal allergic rhinitis volunteered for the study. Nasal biopsies were obtained before and during pollen season as well as before and after allergen challenge. The seasonal material was used for mRNA quantification of Toll-like receptors 2, 3 and 4 with real-time polymerase chain reaction, whereas specimens achieved in conjunction with allergen challenge were used for immunohistochemical localization and quantification of corresponding proteins. Results mRNA and protein representing Toll-like receptors 2, 3 and 4 could be demonstrated in all specimens. An increase in protein expression for all three receptors could be seen following allergen challenge, whereas a significant increase of mRNA only could be obtained for Toll-like receptor 3 during pollen season. Conclusion The up-regulation of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with symptomatic allergic rhinitis supports the idea of a role for Toll-like receptors in allergic airway inflammation.

  9. Differential regulation of dopamine receptors after chronic typical and atypical antipsychotic drug treatment

    International Nuclear Information System (INIS)

    Creese, I.; Florijn, W.J.; Tarazi, F.I.

    1997-01-01

    Changes in dopamine receptor subtype binding in different brain regions were examined after 28 days treatment of rats with haloperidol, raclopride, clozapine or SCH23390 using in vitro receptor autoradiography. [ 3 H]7-hydroxy-N,N-di-n-propyl-2-aminotetralin binding to dopamine D 3 receptors was not changed in any brain region by any of the drug treatments. [ 3 H]SCH23390 was only increased by chronic SCH23390 treatment. Haloperidol significantly increased [ 3 H]nemonapride and [ 3 H]spiperone binding to dopamine D 2 -like receptors in the caudate-putamen. In contrast, haloperidol caused a small, significant increase in [ 3 H]raclopride binding in the lateral caudate-putamen only. Raclopride also elevated, but to a lesser extent [ 3 H]nemonapride and [ 3 H]spiperone binding in caudate-putamen, whereas it did not affect [ 3 H]raclopride binding. Clozapine did not significantly change D 2 -like striatal binding of [ 3 H]nemonapride, [ 3 H]spiperone or [ 3 H]raclopride. The differences in radioligand binding suggest that [ 3 H]nemonapride and [ 3 H]spiperone may be binding to additional subsets of dopamine D 2 -like receptors (including D 4 -like receptors) that are not recognized by [ 3 H]raclopride, which has high affinity for D 2 and D 3 receptors only.Quantification of [ 3 H]nemonapride or [ 3 H]spiperone binding in the presence of 300 nM raclopride (to block D 2 and D 3 receptors) revealed that haloperidol, raclopride and clozapine up-regulated D 4 -like receptors in the caudate-putamen using either radioligand. These results suggest that D 4 -like receptors may be a common site of action of both typical and atypical antipsychotics. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling

    Directory of Open Access Journals (Sweden)

    Song eQin

    2014-04-01

    Full Text Available Neural stem cells (NSCs are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates BMP-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.

  11. Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling.

    Science.gov (United States)

    Qin, Song; Niu, Wenze; Iqbal, Nida; Smith, Derek K; Zhang, Chun-Li

    2014-01-01

    Neural stem cells (NSCs) are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates bone morphogenetic protein (BMP)-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP) and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.

  12. Positioning of AMPA Receptor-Containing Endosomes Regulates Synapse Architecture

    Directory of Open Access Journals (Sweden)

    Marta Esteves da Silva

    2015-11-01

    Full Text Available Lateral diffusion in the membrane and endosomal trafficking both contribute to the addition and removal of AMPA receptors (AMPARs at postsynaptic sites. However, the spatial coordination between these mechanisms has remained unclear, because little is known about the dynamics of AMPAR-containing endosomes. In addition, how the positioning of AMPAR-containing endosomes affects synapse organization and functioning has never been directly explored. Here, we used live-cell imaging in hippocampal neuron cultures to show that intracellular AMPARs are transported in Rab11-positive recycling endosomes, which frequently enter dendritic spines and depend on the microtubule and actin cytoskeleton. By using chemically induced dimerization systems to recruit kinesin (KIF1C or myosin (MyosinV/VI motors to Rab11-positive recycling endosomes, we controlled their trafficking and found that induced removal of recycling endosomes from spines decreases surface AMPAR expression and PSD-95 clusters at synapses. Our data suggest a mechanistic link between endosome positioning and postsynaptic structure and composition.

  13. Mechanism of allosteric regulation of β2-adrenergic receptor by cholesterol

    DEFF Research Database (Denmark)

    Manna, Moutusi; Niemelä, Miia; Tynkkynen, Joona

    2016-01-01

    ) - a prototypical G protein-coupled receptor - is modulated by cholesterol in an allosteric fashion. Extensive atomistic simulations show that cholesterol regulates b2AR by limiting its conformational variability. The mechanism of action is based on the binding of cholesterol at specific high-affinity sites located...... near the transmembrane helices 5-7 of the receptor. The alternative mechanism, where the β2AR conformation would be modulated by membrane-mediated interactions, plays only a minor role. Cholesterol analogues also bind to cholesterol binding sites and impede the structural flexibility of β2AR, however...... cholesterol generates the strongest effect. The results highlight the capacity of lipids to regulate the conformation of membrane receptors through specific interactions....

  14. Antidiabetic phospholipid-nuclear receptor complex reveals the mechanism for phospholipid-driven gene regulation

    Energy Technology Data Exchange (ETDEWEB)

    Musille, Paul M; Pathak, Manish C; Lauer, Janelle L; Hudson, William H; Griffin, Patrick R; Ortlund, Eric A [Emory-MED; (Scripps)

    2013-01-31

    The human nuclear receptor liver receptor homolog-1 (LRH-1) has an important role in controlling lipid and cholesterol homeostasis and is a potential target for the treatment of diabetes and hepatic diseases. LRH-1 is known to bind phospholipids, but the role of phospholipids in controlling LRH-1 activation remains highly debated. Here we describe the structure of both apo LRH-1 and LRH-1 in complex with the antidiabetic phospholipid dilauroylphosphatidylcholine (DLPC). Together with hydrogen-deuterium exchange MS and functional data, our studies show that DLPC binding is a dynamic process that alters co-regulator selectivity. We show that the lipid-free receptor undergoes previously unrecognized structural fluctuations, allowing it to interact with widely expressed co-repressors. These observations enhance our understanding of LRH-1 regulation and highlight its importance as a new therapeutic target for controlling diabetes.

  15. Vitamin D receptor–retinoid X receptor heterodimer signaling regulates oligodendrocyte progenitor cell differentiation

    Science.gov (United States)

    de la Fuente, Alerie Guzman; Errea, Oihana; van Wijngaarden, Peter; Gonzalez, Ginez A.; Kerninon, Christophe; Jarjour, Andrew A.; Lewis, Hilary J.; Jones, Clare A.; Nait-Oumesmar, Brahim; Zhao, Chao; Huang, Jeffrey K.; ffrench-Constant, Charles

    2015-01-01

    The mechanisms regulating differentiation of oligodendrocyte (OLG) progenitor cells (OPCs) into mature OLGs are key to understanding myelination and remyelination. Signaling via the retinoid X receptor γ (RXR-γ) has been shown to be a positive regulator of OPC differentiation. However, the nuclear receptor (NR) binding partner of RXR-γ has not been established. In this study we show that RXR-γ binds to several NRs in OPCs and OLGs, one of which is vitamin D receptor (VDR). Using pharmacological and knockdown approaches we show that RXR–VDR signaling induces OPC differentiation and that VDR agonist vitamin D enhances OPC differentiation. We also show expression of VDR in OLG lineage cells in multiple sclerosis. Our data reveal a role for vitamin D in the regenerative component of demyelinating disease and identify a new target for remyelination medicines. PMID:26644513

  16. Age-related changes in expression and signaling of TAM receptor inflammatory regulators in monocytes.

    Science.gov (United States)

    Wang, Xiaomei; Malawista, Anna; Qian, Feng; Ramsey, Christine; Allore, Heather G; Montgomery, Ruth R

    2018-02-09

    The multifactorial immune deterioration in aging--termed "inflamm-aging"--is comprised of a state of low-grade, chronic inflammation and complex dysregulation of responses to immune stimulation. The TAM family (Tyro 3, Axl, and Mer) of receptor tyrosine kinases are negative regulators of Toll like receptor-mediated immune responses that broadly inhibit cytokine receptor cascades to inhibit inflammation. Here we demonstrate elevated expression of TAM receptors in monocytes of older adults, and an age-dependent difference in signaling mediator AKT resulting in dysregulated responses to signaling though Mer. Our results may be especially significant in tissue, where levels of Mer are highest, and may present avenues for modulation of chronic tissue inflammation noted in aging.

  17. A genome-wide association meta-analysis of circulating sex hormone-binding globulin reveals multiple Loci implicated in sex steroid hormone regulation.

    Directory of Open Access Journals (Sweden)

    Andrea D Coviello

    Full Text Available Sex hormone-binding globulin (SHBG is a glycoprotein responsible for the transport and biologic availability of sex steroid hormones, primarily testosterone and estradiol. SHBG has been associated with chronic diseases including type 2 diabetes (T2D and with hormone-sensitive cancers such as breast and prostate cancer. We performed a genome-wide association study (GWAS meta-analysis of 21,791 individuals from 10 epidemiologic studies and validated these findings in 7,046 individuals in an additional six studies. We identified twelve genomic regions (SNPs associated with circulating SHBG concentrations. Loci near the identified SNPs included SHBG (rs12150660, 17p13.1, p = 1.8 × 10(-106, PRMT6 (rs17496332, 1p13.3, p = 1.4 × 10(-11, GCKR (rs780093, 2p23.3, p = 2.2 × 10(-16, ZBTB10 (rs440837, 8q21.13, p = 3.4 × 10(-09, JMJD1C (rs7910927, 10q21.3, p = 6.1 × 10(-35, SLCO1B1 (rs4149056, 12p12.1, p = 1.9 × 10(-08, NR2F2 (rs8023580, 15q26.2, p = 8.3 × 10(-12, ZNF652 (rs2411984, 17q21.32, p = 3.5 × 10(-14, TDGF3 (rs1573036, Xq22.3, p = 4.1 × 10(-14, LHCGR (rs10454142, 2p16.3, p = 1.3 × 10(-07, BAIAP2L1 (rs3779195, 7q21.3, p = 2.7 × 10(-08, and UGT2B15 (rs293428, 4q13.2, p = 5.5 × 10(-06. These genes encompass multiple biologic pathways, including hepatic function, lipid metabolism, carbohydrate metabolism and T2D, androgen and estrogen receptor function, epigenetic effects, and the biology of sex steroid hormone-responsive cancers including breast and prostate cancer. We found evidence of sex-differentiated genetic influences on SHBG. In a sex-specific GWAS, the loci 4q13.2-UGT2B15 was significant in men only (men p = 2.5 × 10(-08, women p = 0.66, heterogeneity p = 0.003. Additionally, three loci showed strong sex-differentiated effects: 17p13.1-SHBG and Xq22.3-TDGF3 were stronger in men, whereas 8q21.12-ZBTB10 was stronger in women. Conditional analyses identified additional signals at the SHBG gene that together almost double the proportion

  18. Stress-induced release of anterior pituitary hormones: Effect of H3 receptor-mediated inhibition of histaminergic activity or posterior hypothalamic lesion

    DEFF Research Database (Denmark)

    Knigge, U.; Søe-Jensen, P.; Jørgensen, Henrik

    1999-01-01

    Histamine receptors, corticotropin, *Gb-endorphin, prolactin, adrenal steroids, stress, endotoxin, serotonin......Histamine receptors, corticotropin, *Gb-endorphin, prolactin, adrenal steroids, stress, endotoxin, serotonin...

  19. Endothelin-1 and endothelin-3 regulate endothelin receptor expression in rat coronary arteries

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Kilic, Semsi; Edvinsson, Lars

    2015-01-01

    In ischaemic hearts, endothelin (ET) levels are increased, and vasoconstrictor responses to ET-1 are greatly enhanced. We previously reported that ETB receptors are up-regulated in the smooth muscle layer of coronary arteries after myocardial ischaemia-reperfusion and that the MEK-ERK1/2 signalli...

  20. Growth Hormone Receptor Signaling Pathways and its Negative Regulation by SOCS2

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  1. Scratching the surface: Regulation of cell surface receptors in cholesterol metabolism

    NARCIS (Netherlands)

    Nelson, J.K.

    2016-01-01

    Elevated plasma levels of low density lipoprotein cholesterol (LDL) are an established risk factor for the development of atherosclerosis and cardiovascular diseases. The LDL-Receptor is a key determinant in regulating LDL levels in plasma, and current lipid-lowering strategies aim to increase its

  2. Melanocortin receptor 4 deficiency affects body weight regulation, grooming behavior, and substrate preference in the rat

    NARCIS (Netherlands)

    Mul, J.D.; van Boxtel, R.; Bergen, D.J.; Brans, M.A.; Brakkee, J.H.; Toonen, P.W.; Garner, K.M.; Adan, R.A.; Cuppen, E.

    2012-01-01

    Obesity is caused by an imbalance between energy intake and expenditure and has become a major health-care problem in western society. The central melanocortin system plays a crucial role in the regulation of feeding and energy expenditure, and functional loss of melanocortin receptor 4 (MC4R) is

  3. VMAT2-mediated neurotransmission from midbrain leptin receptor neurons in feeding regulation

    Science.gov (United States)

    Leptin receptors (LepRs) expressed in the midbrain contribute to the action of leptin on feeding regulation. The midbrain neurons release a variety of neurotransmitters including dopamine (DA), glutamate and GABA. However, which neurotransmitter mediates midbrain leptin action on feeding remains unc...

  4. CB1 cannabinoid receptor expression in the striatum: Association with corticostriatal circuits and developmental regulation

    Directory of Open Access Journals (Sweden)

    Vincent eVan Waes

    2012-03-01

    Full Text Available Corticostriatal circuits mediate various aspects of goal-directed behavior and are critically important for basal ganglia-related disorders. Activity in these circuits is regulated by the endocannabinoid system via stimulation of CB1 cannabinoid receptors. CB1 receptors are highly expressed in projection neurons and select interneurons of the striatum, but expression levels vary considerably between different striatal regions (functional domains. We investigated CB1 receptor expression within specific corticostriatal circuits by mapping CB1 mRNA levels in striatal sectors defined by their cortical inputs in rats. We also assessed changes in CB1 expression in the striatum during development. Our results show that CB1 expression is highest in juveniles (P25 and then progressively decreases towards adolescent (P40 and adult (P70 levels. At every age, CB1 receptors are predominantly expressed in sensorimotor striatal sectors, with considerably lower expression in associative and limbic sectors. Moreover, for most corticostriatal circuits there is an inverse relationship between cortical and striatal expression levels. Thus, striatal sectors with high CB1 expression (sensorimotor sectors tend to receive inputs from cortical areas with low expression, while striatal sectors with low expression (associative/limbic sectors receive inputs from cortical regions with higher expression (medial prefrontal cortex. In so far as CB1 mRNA levels reflect receptor function, our findings suggest differential CB1 signaling between different developmental stages and between sensorimotor and associative/limbic circuits. The regional distribution of CB1 receptor expression in the striatum further suggests that, in sensorimotor sectors, CB1 receptors mostly regulate GABA inputs from local axon collaterals of projection neurons, whereas in associative/limbic sectors, CB1 regulation of GABA inputs from interneurons and glutamate inputs may be more important.

  5. Prostate cancer cells differ in testosterone accumulation, dihydrotestosterone conversion, and androgen receptor signaling response to steroid 5α-reductase inhibitors.

    Science.gov (United States)

    Wu, Yue; Godoy, Alejandro; Azzouni, Faris; Wilton, John H; Ip, Clement; Mohler, James L

    2013-09-01

    Blocking 5α-reductase-mediated testosterone conversion to dihydrotestosterone (DHT) with finasteride or dutasteride is the driving hypothesis behind two prostate cancer prevention trials. Factors affecting intracellular androgen levels and the androgen receptor (AR) signaling axis need to be examined systematically in order to fully understand the outcome of interventions using these drugs. The expression of three 5α-reductase isozymes, as determined by immunohistochemistry and qRT-PCR, was studied in five human prostate cancer cell lines. Intracellular testosterone and DHT were analyzed using mass spectrometry. A luciferase reporter assay and AR-regulated genes were used to evaluate the modulation of AR activity. Prostate cancer cells were capable of accumulating testosterone to a level 15-50 times higher than that in the medium. The profile and expression of 5α-reductase isozymes did not predict the capacity to convert testosterone to DHT. Finasteride and dutasteride were able to depress testosterone uptake in addition to lowering intracellular DHT. The inhibition of AR activity following drug treatment often exceeded the expected response due to reduced availability of DHT. The ability to maintain high intracellular testosterone might compensate for the shortage of DHT. The biological effect of finasteride or dutasteride appears to be complex and may depend on the interplay of several factors, which include testosterone turnover, enzymology of DHT production, ability to use testosterone and DHT interchangeably, and propensity of cells for off-target AR inhibitory effect. © 2013 Wiley Periodicals, Inc.

  6. DMPD: Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031251 Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory...l) (.csml) Show Toll-like receptor (TLR)-based networks regulate neutrophilic inflammation inrespiratory dis...utrophilic inflammation inrespiratory disease. Authors Sabroe I, Whyte MK. Publication Biochem Soc Trans. 20

  7. Up-regulation of the Neuronal Nicotinic Receptor α7 by HIV Glycoprotein 120

    Science.gov (United States)

    Ballester, Leomar Y.; Capó-Vélez, Coral M.; García-Beltrán, Wilfredo F.; Ramos, Félix M.; Vázquez-Rosa, Edwin; Ríos, Raymond; Mercado, José R.; Meléndez, Roberto I.; Lasalde-Dominicci, José A.

    2012-01-01

    Approximately 30–50% of the >30 million HIV-infected subjects develop neurological complications ranging from mild symptoms to dementia. HIV does not infect neurons, and the molecular mechanisms behind HIV-associated neurocognitive decline are not understood. There are several hypotheses to explain the development of dementia in HIV+ individuals, including neuroinflammation mediated by infected microglia and neuronal toxicity by HIV proteins. A key protein associated with the neurological complications of HIV, gp120, forms part of the viral envelope and can be found in the CSF of infected individuals. HIV-1-gp120 interacts with several receptors including CD4, CCR5, CXCR4, and nicotinic acetylcholine receptors (nAChRs). However, the role of nAChRs in HIV-associated neurocognitive disorder has not been investigated. We studied the effects of gp120IIIB on the expression and function of the nicotinic receptor α7 (α7-nAChR). Our results show that gp120, through activation of the CXCR4 chemokine receptor, induces a functional up-regulation of α7-nAChRs. Because α7-nAChRs have a high permeability to Ca2+, we performed TUNEL staining to investigate the effects of receptor up-regulation on cell viability. Our data revealed an increase in cell death, which was blocked by the selective antagonist α-bungarotoxin. The in vitro data are supported by RT-PCR and Western blot analysis, confirming a remarkable up-regulation of the α7-nAChR in gp120-transgenic mice brains. Specifically, α7-nAChR up-regulation is observed in mouse striatum, a region severely affected in HIV+ patients. In summary, CXCR4 activation induces up-regulation of α7-nAChR, causing cell death, suggesting that α7-nAChR is a previously unrecognized contributor to the neurotoxicity associated with HIV infection. PMID:22084248

  8. 2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Karman, Bethany N., E-mail: bklement@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbshivapur@gmail.com; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2012-05-15

    The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1–100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3–4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. -- Highlights: ►TCDD disrupts sex steroid hormone levels, but not growth of antral follicles. ►Pregnenolone co-treatment by-passes TCDD-induced steroid hormone disruption. ►TCDD affects steroid hormone levels through an AHR pathway in antral follicles.

  9. Phosphatidylserine Sensing by TAM Receptors Regulates AKT-Dependent Chemoresistance and PD-L1 Expression.

    Science.gov (United States)

    Kasikara, Canan; Kumar, Sushil; Kimani, Stanley; Tsou, Wen-I; Geng, Ke; Davra, Viralkumar; Sriram, Ganapathy; Devoe, Connor; Nguyen, Khanh-Quynh N; Antes, Anita; Krantz, Allen; Rymarczyk, Grzegorz; Wilczynski, Andrzej; Empig, Cyril; Freimark, Bruce; Gray, Michael; Schlunegger, Kyle; Hutchins, Jeff; Kotenko, Sergei V; Birge, Raymond B

    2017-06-01

    Tyro3, Axl, and Mertk (collectively TAM receptors) are three homologous receptor tyrosine kinases that bind vitamin K-dependent endogenous ligands, Protein S (ProS), and growth arrest-specific factor 6 (Gas6), and act as bridging molecules to promote phosphatidylserine (PS)-mediated clearance of apoptotic cells (efferocytosis). TAM receptors are overexpressed in a vast array of tumor types, whereby the level of expression correlates with the tumor grade and the emergence of chemo- and radioresistance to targeted therapeutics, but also have been implicated as inhibitory receptors on infiltrating myeloid-derived cells in the tumor microenvironment that can suppress host antitumor immunity. In the present study, we utilized TAM-IFNγR1 reporter lines and expressed TAM receptors in a variety of epithelial cell model systems to show that each TAM receptor has a unique pattern of activation by Gas6 or ProS, as well as unique dependency for PS on apoptotic cells and PS liposomes for activity. In addition, we leveraged this system to engineer epithelial cells that express wild-type TAM receptors and show that although each receptor can promote PS-mediated efferocytosis, AKT-mediated chemoresistance, as well as upregulate the immune checkpoint molecule PD-L1 on tumor cells, Mertk is most dominant in the aforementioned pathways. Functionally, TAM receptor-mediated efferocytosis could be partially blocked by PS-targeting antibody 11.31 and Annexin V, demonstrating the existence of a PS/PS receptor (i.e., TAM receptor)/PD-L1 axis that operates in epithelial cells to foster immune escape. These data provide a rationale that PS-targeting, anti-TAM receptor, and anti-PD-L1-based therapeutics will have merit as combinatorial checkpoint inhibitors. Implications: Many tumor cells are known to upregulate the immune checkpoint inhibitor PD-L1. This study demonstrates a role for PS and TAM receptors in the regulation of PD-L1 on cancer cells. Mol Cancer Res; 15(6); 753-64. ©2017 AACR

  10. Large-Scale Phosphoproteomics Reveals Shp-2 Phosphatase-Dependent Regulators of Pdgf Receptor Signaling

    DEFF Research Database (Denmark)

    Batth, Tanveer S; Papetti, Moreno; Pfeiffer, Anamarija

    2018-01-01

    Despite its low cellular abundance, phosphotyrosine (pTyr) regulates numerous cell signaling pathways in health and disease. We applied comprehensive phosphoproteomics to unravel differential regulators of receptor tyrosine kinase (RTK)-initiated signaling networks upon activation by Pdgf-ββ, Fgf-2...... of Pdgfr pTyr signaling. Application of a recently introduced allosteric Shp-2 inhibitor revealed global regulation of the Pdgf-dependent tyrosine phosphoproteome, which significantly impaired cell migration. In addition, we present a list of hundreds of Shp-2-dependent targets and putative substrates...

  11. DMPD: Translational mini-review series on Toll-like receptors: networks regulated byToll-like receptors mediate innate and adaptive immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17223959 Translational mini-review series on Toll-like receptors: networks regulate...ol. 2007 Feb;147(2):199-207. (.png) (.svg) (.html) (.csml) Show Translational mini-review series on Toll-lik... immunity. PubmedID 17223959 Title Translational mini-review series on Toll-like receptors: networks regulat

  12. Regulation of pyruvate dehydrogenase kinase expression by the farnesoid X receptor

    International Nuclear Information System (INIS)

    Savkur, Rajesh S.; Bramlett, Kelli S.; Michael, Laura F.; Burris, Thomas P.

    2005-01-01

    The pyruvate dehydrogenase complex (PDC) functions as an important junction in intermediary metabolism by influencing the utilization of fat versus carbohydrate as a source of fuel. Activation of PDC is achieved by phosphatases, whereas, inactivation is catalyzed by pyruvate dehydrogenase kinases (PDKs). The expression of PDK4 is highly regulated by the glucocorticoid and peroxisome proliferator-activated receptors. We demonstrate that the farnesoid X receptor (FXR; NR1H4), which regulates a variety of genes involved in lipoprotein metabolism, also regulates the expression of PDK4. Treatment of rat hepatoma cells as well as human primary hepatocytes with FXR agonists stimulates the expression of PDK4 to levels comparable to those obtained with glucocorticoids. In addition, treatment of mice with an FXR agonist significantly increased hepatic PDK4 expression, while concomitantly decreasing plasma triglyceride levels. Thus, activation of FXR may suppress glycolysis and enhance oxidation of fatty acids via inactivation of the PDC by increasing PDK4 expression

  13. Steroids (For Parents)

    Science.gov (United States)

    ... build muscle, steroids can have very serious side effects. Using steroids for a long time can harm the reproductive ... Teen girls and women risk these additional side effects: male-type facial and body ... risks, kids who use steroids without a prescription are breaking the law. Drug ...

  14. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  15. Dopamine D2 receptors preferentially regulate the development of light responses of the inner retina

    Science.gov (United States)

    Tian, Ning; Xu, Hong-ping; Wang, Ping

    2014-01-01

    Retinal light responsiveness measured via electroretinography undergoes developmental modulation and is thought to be critically regulated by both visual experience and dopamine. The primary goal of this study is to determine whether the dopamine D2 receptor regulates the visual experience-dependent functional development of the retina. Accordingly, we recorded electroretinograms from wild type mice and mice with a genetic deletion of the gene that encodes the dopamine D2 receptor raised under normal cyclic light conditions and constant darkness. Our results demonstrate that mutation of the dopamine D2 receptors preferentially increases the amplitude of the inner retinal light responses evoked by high intensity light measured as oscillatory potentials in adult mice. During postnatal development, all three major components of electroretinograms, the a-wave, b-wave and oscillatory potentials, increase with age. Comparatively, mutation of the dopamine D2 receptors preferentially reduces the age-dependent increase of b-waves evoked by low intensity light. Light deprivation from birth reduces the amplitude of b-waves and completely diminishes the increased amplitude of oscillatory potentials. Taken together, these results demonstrate that the dopamine D2 receptor plays an important role in the activity-dependent functional development of the mouse retina. PMID:25393815

  16. ARF6-dependent regulation of P2Y receptor traffic and function in human platelets.

    Science.gov (United States)

    Kanamarlapudi, Venkateswarlu; Owens, Sian E; Saha, Keya; Pope, Robert J; Mundell, Stuart J

    2012-01-01

    Adenosine diphosphate (ADP) is a critical regulator of platelet activation, mediating its actions through two G protein-coupled receptors, the P2Y(1) and P2Y(12) purinoceptors. Recently, we demonstrated that P2Y(1) and P2Y(12) purinoceptor activities are rapidly and reversibly modulated in human platelets, revealing that the underlying mechanism requires receptor internalization and subsequent trafficking as an essential part of this process. In this study we investigated the role of the small GTP-binding protein ADP ribosylation factor 6 (ARF6) in the internalization and function of P2Y(1) and P2Y(12) purinoceptors in human platelets. ARF6 has been implicated in the internalization of a number of GPCRs, although its precise molecular mechanism in this process remains unclear. In this study we show that activation of either P2Y(1) or P2Y(12) purinoceptors can stimulate ARF6 activity. Further blockade of ARF6 function either in cell lines or human platelets blocks P2Y purinoceptor internalization. This blockade of receptor internalization attenuates receptor resensitization. Furthermore, we demonstrate that Nm23-H1, a nucleoside diphosphate (NDP) kinase regulated by ARF6 which facilitates dynamin-dependent fission of coated vesicles during endocytosis, is also required for P2Y purinoceptor internalization. These data describe a novel function of ARF6 in the internalization of P2Y purinoceptors and demonstrate the integral importance of this small GTPase upon platelet ADP receptor function.

  17. ARF6-dependent regulation of P2Y receptor traffic and function in human platelets.

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Kanamarlapudi

    Full Text Available Adenosine diphosphate (ADP is a critical regulator of platelet activation, mediating its actions through two G protein-coupled receptors, the P2Y(1 and P2Y(12 purinoceptors. Recently, we demonstrated that P2Y(1 and P2Y(12 purinoceptor activities are rapidly and reversibly modulated in human platelets, revealing that the underlying mechanism requires receptor internalization and subsequent trafficking as an essential part of this process. In this study we investigated the role of the small GTP-binding protein ADP ribosylation factor 6 (ARF6 in the internalization and function of P2Y(1 and P2Y(12 purinoceptors in human platelets. ARF6 has been implicated in the internalization of a number of GPCRs, although its precise molecular mechanism in this process remains unclear. In this study we show that activation of either P2Y(1 or P2Y(12 purinoceptors can stimulate ARF6 activity. Further blockade of ARF6 function either in cell lines or human platelets blocks P2Y purinoceptor internalization. This blockade of receptor internalization attenuates receptor resensitization. Furthermore, we demonstrate that Nm23-H1, a nucleoside diphosphate (NDP kinase regulated by ARF6 which facilitates dynamin-dependent fission of coated vesicles during endocytosis, is also required for P2Y purinoceptor internalization. These data describe a novel function of ARF6 in the internalization of P2Y purinoceptors and demonstrate the integral importance of this small GTPase upon platelet ADP receptor function.

  18. Negative Regulation of Receptor Tyrosine Kinase (RTK Signaling: A Developing Field

    Directory of Open Access Journals (Sweden)

    Fernanda Ledda

    2007-01-01

    Full Text Available ophic factors control cellular physiology by activating specific receptor tyrosine kinases (RTKs. While the over activation of RTK signaling pathways is associated with cell growth and cancer, recent findings support the concept that impaired down-regulation or deactivation of RTKs may also be a mechanism involved in tumor formation. Under this perspective, the molecular determinants of RTK signaling inhibition may act as tumor-suppressor genes and have a potential role as tumor markers to monitor and predict disease progression. Here, we review the current understanding of the physiological mechanisms that attenuate RTK signaling and discuss evidence that implicates deregulation of these events in cancer.Abbreviations: BDP1: Brain-derived phosphatase 1; Cbl: Casitas B-lineage lymphoma; CIN-85: Cbl-interacting protein of 85 kDa; DER: Drosophila EGFR; EGFR: Epidermal growth factor receptor; ERK 1/2: Extracellular signal-regulated kinase 1/2; Grb2: Growth factor receptor-bound protein 2; HER2: Human epidermal growth factor receptor 2; LRIG: Leucine-rich repeats and immunoglobulin-like domain 1; MAPK: Mitogen-activated protein kinase; Mig 6: Mitogen-inducible gene 6; PTEN: Phosphatase and tensin homologue; RET: Rearranged in transformation; RTK: Receptor tyrosine kinase. SH2 domain: Src-homology 2 domain; SH3 domain: Src-homology 3 domain; Spry: Sprouty.

  19. Beyond the reproductive effect of sex steroids: their role during immunity to helminth parasite infections.

    Science.gov (United States)

    Hernández-Bello, R; Nava-Castro, K; Muñiz-Hernández, S; Nava-Luna, P; Trejo-Sánchez, Itztli; Tiempos-Guzmán, N; Mendoza-Rodríguez, Y; Morales-Montor, J

    2012-10-01

    During the helminth infections, the immune system tends to be modulated by host's sex hormones. Actually, many studies show the reciprocal relationship between sex steroids, the immune system and the elimination or establishment of helminth parasites. Is well known that innate immune response determines the type of adaptive immune response, so the effects in the innate immune response by hormones may affect subsequent adaptive immunity. The sex steroids as estrogens, progesterone and testosterone regulate growth, differentiation, survival and function of many cell types that could be involved in process like homeostasis and immunity, but also have a direct effect on the helminthes, that may probably be mediated by specific receptors on these parasites. Sex steroids, parasites and immunity are closely connected, and their interconnection is involved in the maintenance of elimination or establishment of helminthes in an immunocompetent host. For that reason, understanding the action's mechanisms of sex steroids on immune cells and its direct effect on helminth parasites is important for further progress in the development of novel therapies for chronic helminth diseases associated to immune dysregulation. In this review, we will describe the effects of sex steroids on the immune response during helminth infections as well as the direct effect in these parasites, and the possible implications of these effects on the incidence of several helminth infections.

  20. Human neural progenitors express functional lysophospholipid receptors that regulate cell growth and morphology

    Directory of Open Access Journals (Sweden)

    Callihan Phillip

    2008-12-01

    Full Text Available Abstract Background Lysophospholipids regulate the morphology and growth of neurons, neural cell lines, and neural progenitors. A stable human neural progenitor cell line is not currently available in which to study the role of lysophospholipids in human neural development. We recently established a stable, adherent human embryonic stem cell-derived neuroepithelial (hES-NEP cell line which recapitulates morphological and phenotypic features of neural progenitor cells isolated from fetal tissue. The goal of this study was to determine if hES-NEP cells express functional lysophospholipid receptors, and if activation of these receptors mediates cellular responses critical for neural development. Results Our results demonstrate that Lysophosphatidic Acid (LPA and Sphingosine-1-phosphate (S1P receptors are functionally expressed in hES-NEP cells and are coupled to multiple cellular signaling pathways. We have shown that transcript levels for S1P1 receptor increased significantly in the transition from embryonic stem cell to hES-NEP. hES-NEP cells express LPA and S1P receptors coupled to Gi/o G-proteins that inhibit adenylyl cyclase and to Gq-like phospholipase C activity. LPA and S1P also induce p44/42 ERK MAP kinase phosphorylation in these cells and stimulate cell proliferation via Gi/o coupled receptors in an Epidermal Growth Factor Receptor (EGFR- and ERK-dependent pathway. In contrast, LPA and S1P stimulate transient cell rounding and aggregation that is independent of EGFR and ERK, but dependent on the Rho effector p160 ROCK. Conclusion Thus, lysophospholipids regulate neural progenitor growth and morphology through distinct mechanisms. These findings establish human ES cell-derived NEP cells as a model system for studying the role of lysophospholipids in neural progenitors.

  1. Interactions between Type III receptor tyrosine phosphatases and growth factor receptor tyrosine kinases regulate tracheal tube formation in Drosophila

    Directory of Open Access Journals (Sweden)

    Mili Jeon

    2012-04-01

    The respiratory (tracheal system of the Drosophila melanogaster larva is an intricate branched network of air-filled tubes. Its developmental logic is similar in some ways to that of the vertebrate vascular system. We previously described a unique embryonic tracheal tubulogenesis phenotype caused by loss of both of the Type III receptor tyrosine phosphatases (RPTPs, Ptp4E and Ptp10D. In Ptp4E Ptp10D double mutants, the linear tubes in unicellular and terminal tracheal branches are converted into bubble-like cysts that incorporate apical cell surface markers. This tube geometry phenotype is modulated by changes in the activity or expression of the epidermal growth factor receptor (Egfr tyrosine kinase (TK. Ptp10D physically interacts with Egfr. Here we demonstrate that the Ptp4E Ptp10D phenotype is the consequence of the loss of negative regulation by the RPTPs of three growth factor receptor TKs: Egfr, Breathless and Pvr. Reducing the activity of any of the three kinases by tracheal expression of dominant-negative mutants suppresses cyst formation. By competing dominant-negative and constitutively active kinase mutants against each other, we show that the three RTKs have partially interchangeable activities, so that increasing the activity of one kinase can compensate for the effects of reducing the activity of another. This implies that SH2-domain downstream effectors that are required for the phenotype are likely to be able to interact with phosphotyrosine sites on all three receptor TKs. We also show that the phenotype involves increases in signaling through the MAP kinase and Rho GTPase pathways.

  2. Insulin and IGF receptors are developmentally regulated in the chick embry eye lens

    International Nuclear Information System (INIS)

    Bassas, L.; Zelenka, P.S.; Serrano, J.; de Pablo, F.

    1987-01-01

    The authors have previously reported that insulin-like growth factor (IGF) receptors appear to predominate over insulin receptors in early stages of embryogenesis in the chick (days 2-3 whole embryo membranes). Overall, [ 125 I]IGF and II binding to specific receptors was maximal when the rate of brain growth is highest. In the present study they used the embryonic chick lens, a well-defined tissue composed of a single type of cell, to analyze whether changes of insulin and IGFI binding are correlated with changes in growth rate and differentiation state of the cells. They show that both insulin receptors and IGF receptors are present in the lens epithelial cells, and that each type is distinctly regulated throughout development. While there is a direct correlation between IFG-binding capability and growth rate of the cells, there is less relation to differentiation status and embryo age. Insulin receptors, by contrast, appear to be mostly related to the differentiated state of cells, decreasing sharply in fibers, irrespective of their developmental age

  3. Bicaudal-D1 regulates the intracellular sorting and signalling of neurotrophin receptors.

    Science.gov (United States)

    Terenzio, Marco; Golding, Matthew; Russell, Matthew R G; Wicher, Krzysztof B; Rosewell, Ian; Spencer-Dene, Bradley; Ish-Horowicz, David; Schiavo, Giampietro

    2014-07-17

    We have identified a new function for the dynein adaptor Bicaudal D homolog 1 (BICD1) by screening a siRNA library for genes affecting the dynamics of neurotrophin receptor-containing endosomes in motor neurons (MNs). Depleting BICD1 increased the intracellular accumulation of brain-derived neurotrophic factor (BDNF)-activated TrkB and p75 neurotrophin receptor (p75(NTR)) by disrupting the endosomal sorting, reducing lysosomal degradation and increasing the co-localisation of these neurotrophin receptors with retromer-associated sorting nexin 1. The resulting re-routing of active receptors increased their recycling to the plasma membrane and altered the repertoire of signalling-competent TrkB isoforms and p75(NTR) available for ligand binding on the neuronal surface. This resulted in attenuated, but more sustained, AKT activation in response to BDNF stimulation. These data, together with our observation that Bicd1 expression is restricted to the developing nervous system when neurotrophin receptor expression peaks, indicate that BICD1 regulates neurotrophin signalling by modulating the endosomal sorting of internalised ligand-activated receptors. © 2014 The Authors.

  4. Endogenous ligands for C-type lectin receptors: the true regulators of immune homeostasis.

    Science.gov (United States)

    García-Vallejo, Juan J; van Kooyk, Yvette

    2009-07-01

    C-type lectin receptors (CLRs) have long been known as pattern-recognition receptors implicated in the recognition of pathogens by the innate immune system. However, evidence is accumulating that many CLRs are also able to recognize endogenous 'self' ligands and that this recognition event often plays an important role in immune homeostasis. In the present review, we focus on the human and mouse CLRs for which endogenous ligands have been described. Special attention is given to the signaling events initiated upon recognition of the self ligand and the regulation of glycosylation as a switch modulating CLR recognition, and therefore, immune homeostasis.

  5. Metabolic Action Of Sex Steroids: The Effects Of Testosterone and ...

    African Journals Online (AJOL)

    It has been widely reported that sex steroids affect carbohydrate metabolism and may have influences on hepatic enzymes. There have also been reports that glucocorticoids and sex steroids sometimes bind to similar receptors. All these suggest possible functional similarities or antagonism between glucocorticoids and ...

  6. Effect of electro-acupuncture on ovarian expression of α (1- and β (2-adrenoceptors, and p75 neurotrophin receptors in rats with steroid-induced polycystic ovaries

    Directory of Open Access Journals (Sweden)

    Holmäng Agneta

    2005-06-01

    Full Text Available Abstract Background Estradiol valerate (EV-induced polycystic ovaries (PCO in rats is associated with an increase in ovarian sympathetic outflow. Low-frequency (2 Hz electro-acupuncture (EA has been shown to modulate sympathetic markers as well as ovarian blood flow as a reflex response via the ovarian sympathetic nerves, in rats with EV-induced PCO. Methods In the present study, we further tested the hypothesis that repeated 2 Hz EA treatments modulate ovarian sympathetic outflow in rats with PCO, induced by a single i.m. injection of EV, by investigating the mRNA expression, the amount and distribution of proteins of α1a-, α1b-, α1d-, and β2-adrenoceptors (ARs, as well as the low-affinity neurotrophin receptor (p75NTR. Results It was found that EV injection results in significantly higher mRNA expression of ovarian α1b- and α1d-AR in PCO rats compared to control rats. The p75NTR and β2-ARs mRNA expression were unchanged in the PCO ovary. Low-frequency EA resulted in a significantly lower expression of β2-ARs mRNA expression in PCO rats. The p75NTR mRNA was unaffected in both PCO and control rats. PCO ovaries displayed significantly higher amount of protein of α1a-, α1b- and α1d-ARs, and of p75NTR, compared to control rats, that were all counteracted by repeated low-frequency EA treatments, except for α1b-AR. Conclusion The present study shows that EA normalizes most of the EV-induced changes in ovarian ARs. Furthermore, EA was able to prevent the EV-induced up regulation of p75NTR, probably by normalizing the sympathetic ovarian response to NGF action. Our data indicate a possible role of EA in the regulation of ovarian responsiveness to sympathetic inputs and depict a possible complementary therapeutic approach to overcoming sympathetic-related anovulation in women with PCOS.

  7. Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated?

    Science.gov (United States)

    Paitz, Ryan T; Duffield, Kristin R; Bowden, Rachel M

    2017-12-15

    All vertebrate embryos are exposed to maternally derived steroids during development. In placental vertebrates, metabolism of maternal steroids by the placenta modulates embryonic exposure, but how exposure is regulated in oviparous vertebrates is less clear. Recent work in oviparous vertebrates has demonstrated that steroids are not static molecules, as they can be converted to more polar steroid sulfates by sulfotransferase enzymes. Importantly, these steroid sulfates can be converted back to the parent compound by the enzyme steroid sulfatase (STS). We investigated when and where STS was present during embryonic development in the red-eared slider turtle, Trachemys scripta We report that STS is present during all stages of development and in all tissues we examined. We conclude that STS activity may be particularly important for regulating maternal steroid exposure in oviparous vertebrates. © 2017. Published by The Company of Biologists Ltd.

  8. Pancreatic acini possess endothelin receptors whose internalization is regulated by PLC-activating agents.

    Science.gov (United States)

    Hildebrand, P; Mrozinski, J E; Mantey, S A; Patto, R J; Jensen, R T

    1993-05-01

    Endothelin-1 (ET-1) and ET-3 mRNA have been found in the pancreas. We investigated the ability of ET-1, ET-2, and ET-3 to interact with and alter dispersed rat pancreatic acinar cell function. Radiolabeled ETs bound in a time- and temperature-dependent fashion, which was specific and saturable. Analysis demonstrated two classes of receptors, one class (ETA receptor) had a high affinity for ET-1 but a low affinity for ET-3, and the other class (ETB receptor) had equally high affinities for ET-1 and ET-3. No specific receptor for ET-2 was identified. Pancreatic secretagogues that activate phospholipase C (PLC) inhibited binding of 125I-labeled ET-1 (125I-ET-1) or 125I-ET-3, whereas agents that act through adenosine 3',5'-cyclic monophosphate (cAMP) did not. A23187 had no effect on 125I-ET-1 or 125I-ET-3 binding, whereas the phorbol ester 12-O-tetradecanoylphorbol 13-acetate reduced binding. The effect of cholecystokinin octapeptide (CCK-8) was mediated through its own receptor. Stripping of surface bound ligand studies demonstrated that both 125I-labeled ET-1 and 125I-labeled ET-3 were rapidly internalized. CCK-8 decreased the internalization but did not change the amount of surface bound ligand. Endothelins neither stimulate nor alter changes in enzyme secretion, intracellular calcium, cAMP, or [3H]inositol trisphosphate (IP3). This study demonstrates the presence of ETA and ETB receptors on rat pancreatic acini; occupation of both receptors resulted in rapid internalization, which is regulated by PLC-activating secretagogues. Occupation of either ET receptor did not alter intracellular calcium, cAMP, IP3, or stimulate amylase release.

  9. Nuclear receptor 4a3 (nr4a3 regulates murine mast cell responses and granule content.

    Directory of Open Access Journals (Sweden)

    Gianni Garcia-Faroldi

    Full Text Available Nuclear receptor 4a3 (Nr4a3 is a transcription factor implicated in various settings such as vascular biology and inflammation. We have recently shown that mast cells dramatically upregulate Nuclear receptor 4a3 upon activation, and here we investigated the functional impact of Nuclear receptor 4a3 on mast cell responses. We show that Nuclear receptor 4a3 is involved in the regulation of cytokine/chemokine secretion in mast cells following activation via the high affinity IgE receptor. Moreover, Nuclear receptor 4a3 negatively affects the transcript and protein levels of mast cell tryptase as well as the mast cell's responsiveness to allergen. Together, these findings identify Nuclear receptor 4a3 as a novel regulator of mast cell function.

  10. Neuropilin 1 Receptor Is Up-Regulated in Dysplastic Epithelium and Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Shahrabi-Farahani, Shokoufeh; Gallottini, Marina; Martins, Fabiana; Li, Erik; Mudge, Dayna R; Nakayama, Hironao; Hida, Kyoko; Panigrahy, Dipak; D'Amore, Patricia A; Bielenberg, Diane R

    2016-04-01

    Neuropilins are receptors for disparate ligands, including proangiogenic factors such as vascular endothelial growth factor and inhibitory class 3 semaphorin (SEMA3) family members. Differentiated cells in skin epithelium and cutaneous squamous cell carcinoma highly express the neuropilin-1 (NRP1) receptor. We examined the expression of NRP1 in human and mouse oral mucosa. NRP1 was significantly up-regulated in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). NRP1 receptor localized to the outer suprabasal epithelial layers in normal tongue, an expression pattern similar to the normal skin epidermis. However, dysplastic tongue epithelium and OSCC up-regulated NRP1 in basal and proliferating epithelial layers, a profile unseen in cutaneous squamous cell carcinoma. NRP1 up-regulation is observed in a mouse carcinogen-induced OSCC model and in human tongue OSCC biopsies. Human OSCC cell lines express NRP1 protein in vitro and in mouse tongue xenografts. Sites of capillary infiltration into orthotopic OSCC tumors correlate with high NRP1 expression. HSC3 xenografts, which express the highest NRP1 levels of the cell lines examined, showed massive intratumoral lymphangiogenesis. SEMA3A inhibited OSCC cell migration, suggesting that the NRP1 receptor was bioactive in OSCC. In conclusion, NRP1 is regulated in the oral epithelium and is selectively up-regulated during epithelial dysplasia. NRP1 may function as a reservoir to sequester proangiogenic ligands within the neoplastic compartment, thereby recruiting neovessels toward tumor cells. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  11. Differential regulation of renal prostaglandin receptor mRNAs by dietary salt intake in the rat

    DEFF Research Database (Denmark)

    Jensen, B L; Mann, Birgitte; Skøtt, O

    1999-01-01

    and cells by ribonuclease protection assay and reverse transcription-polymerase chain reaction analysis. Functional correlates were studied by measurement of PGE2-induced cAMP formation and renin secretion in juxtaglomerular (JG) cells isolated from animals on various salt intakes. RESULTS: EP1 and EP3......BACKGROUND: In this study, we tested the hypothesis that prostaglandin (PG) receptor expression in the rat kidney is subject to physiological regulation by dietary salt intake. METHODS: Rats were fed diets with 0.02 or 4% NaCl for two weeks. PG receptor expression was assayed in kidney regions...... did not affect the expression of EP1 or IP receptors, whereas EP4 transcripts in glomeruli were increased twofold by salt deprivation. Consistent with this, we found that PGE2-evoked cAMP production and renin secretion by JG cells from salt-deprived animals were significantly higher compared...

  12. Guanine nucleotide regulation of α1-adrenergic receptors of muscle and kidney eptihelial cells

    International Nuclear Information System (INIS)

    Terman, B.I.; Hughes, R.J.; Slivka, S.R.; Insel, P.A.

    1986-01-01

    The authors have examined the effect of guanine nucleotides on the interaction of adrenergic agents with α 1 -adrenergic receptors of two cell lines, the Madin-Darby Canine Kidney (MDCK) and BC3H-1 muscle cells. While gaunylylimidodiphosphoate (Gpp(NH)p) had no effect on the affinity or the total number of [ -3 H]prazosin binding sites in membranes prepared from these cells, the nucleotide decreased the apparent affinity of the agonist epinephrine in competing for [ 3 H]prazosin binding sites in both cell types. The EC 50 of Gpp(NH)p was ∼100 μM, and a maximal effect was seen at 500 μM. In contrast, 100 μM Gpp(NH)p yielding maximal shifts in binding of epinephrine to β-adrenergic receptors in BC3H-1 cell membranes. Guanine nucleotides were significantly more effective than adenine nucleotides in shifting agonist affinity for the α 1 -receptor and Mg ++ was required to observe a maximal effect. α 1 -receptor agonists activated phosphatidylinositol (PI) hydrolysis in both cell types, but have no direct effect on membrane adenylate cyclase activity. In intact BC3H-1 cells, α 1 -agonists inhibited β-adrenergic cAMP production, an effect which appears in preliminary studies not to result from enhanced phosphodieterase activity. These results show that agonist binding to α 1 -adrenergic receptors in mammalian kidney and muscle cells is regulated by guanine nucleotides. This regulation and inturn transmembrane signalling (PI hydrolysis) by these receptors appear to involve a guanine nucleotide binding (G) protein, which may be different than G/sub s/ and G/sub i/

  13. Involvement of spinal serotonin receptors in the regulation of intraspinal acetylcholine release.

    Science.gov (United States)

    Kommalage, Mahinda; Höglund, A Urban

    2005-02-21

    Stimulation of spinal serotonin (5-HT) receptors results in analgesia and release of acetylcholine. We investigated the involvement of 5-HT1, 5-HT2, and 5-HT3 receptor subtypes in the regulation of spinal acetylcholine release. A spinal microdialysis probe was placed dorsally at about the C5 level in anaesthetized rats. The selective serotonin reuptake inhibitor citalopram was found to increase acetylcholine release when infused via the microdialysis probe. Several doses of the 5-HT receptor agonists 8-hydroxy-2-(di-n-propylamino)tetraline (8-OH-DPAT, 5-HT1A), 1,4-dihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl)-5H-pyrrolo[3,2-b]pyridin-5-one dihydrochloride (CP93129, 5-HT1B), alpha-methyl-5-hydroxytryptamine maleate (m5-HT, 5-HT2), 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 5-HT2C), and 1-(m-chlorophenyl)-biguanide (5-HT3) were subsequently infused via the microdialysis probe. Only 8-OH-DPAT, CP93129, and m5-HT increased acetylcholine release dose dependently. The 5-HT1A receptor selective antagonist (S)-N-tert-butyl-3-(4-(2-methoxyphenyl)piperazine-1-yl)-2-phenylpropanamide hydrochloride and the 5-HT2A receptor selective antagonist ketanserin tartrate inhibited the 8-OH-DPAT and the m5-HT induced acetylcholine release. The results suggest that 5-HT1A and the 5-HT2A receptors are involved in the regulation of acetylcholine release in the spinal cord.

  14. Ghrelin receptor regulates appetite and satiety during aging in mice by regulating meal frequency and portion size but not total food intake

    Science.gov (United States)

    Aging is often associated with overweight and obesity. There exists a long-standing debate about whether meal pattern also contributes to the development of obesity. The orexigenic hormone ghrelin regulates appetite and satiety by activating its receptor, growth hormone secretagogue receptor (GHS-R)...

  15. Regulation of retinoid X receptor gamma expression by fed state in mouse liver

    International Nuclear Information System (INIS)

    Park, Sangkyu; Lee, Yoo Jeong; Ko, Eun Hee; Kim, Jae-woo

    2015-01-01

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα

  16. Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Joanna Bandoła

    2017-08-01

    Full Text Available Plasmacytoid dendritic cells (pDCs regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR by the antigen-presenting pDCs, mediated by toll-like receptor (TLR 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

  17. Metabolite-Sensing G Protein-Coupled Receptors-Facilitators of Diet-Related Immune Regulation.

    Science.gov (United States)

    Tan, Jian K; McKenzie, Craig; Mariño, Eliana; Macia, Laurence; Mackay, Charles R

    2017-04-26

    Nutrition and the gut microbiome regulate many systems, including the immune, metabolic, and nervous systems. We propose that the host responds to deficiency (or sufficiency) of dietary and bacterial metabolites in a dynamic way, to optimize responses and survival. A family of G protein-coupled receptors (GPCRs) termed the metabolite-sensing GPCRs bind to various metabolites and transmit signals that are important for proper immune and metabolic functions. Members of this family include GPR43, GPR41, GPR109A, GPR120, GPR40, GPR84, GPR35, and GPR91. In addition, bile acid receptors such as GPR131 (TGR5) and proton-sensing receptors such as GPR65 show similar features. A consistent feature of this family of GPCRs is that they provide anti-inflammatory signals; many also regulate metabolism and gut homeostasis. These receptors represent one of the main mechanisms whereby the gut microbiome affects vertebrate physiology, and they also provide a link between the immune and metabolic systems. Insufficient signaling through one or more of these metabolite-sensing GPCRs likely contributes to human diseases such as asthma, food allergies, type 1 and type 2 diabetes, hepatic steatosis, cardiovascular disease, and inflammatory bowel diseases.

  18. Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

    Directory of Open Access Journals (Sweden)

    Shanna L. Bowman

    2015-03-01

    Full Text Available How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP, a neuropeptide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R receptor, increases the post-endocytic recycling of the mu-opioid receptor (MOR in trigeminal ganglion (TG neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeostatic interaction between the pain and analgesic systems.

  19. Regulation of retinoid X receptor gamma expression by fed state in mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangkyu, E-mail: 49park@cku.ac.kr [Department of Biochemistry, College of Medicine, Catholic Kwandong University, Gangneung 210-701 (Korea, Republic of); Lee, Yoo Jeong [Division of Metabolic Disease, Center for Biomedical Sciences, National Institute of Health Korea, Osong 361-709 (Korea, Republic of); Ko, Eun Hee [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jae-woo [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752 (Korea, Republic of)

    2015-02-27

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα.

  20. Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells.

    Science.gov (United States)

    Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

    2017-01-01

    Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

  1. Regulation of platelet activating factor receptor coupled phosphoinositide-specific phospholipase C activity

    International Nuclear Information System (INIS)

    Morrison, W.J.

    1988-01-01

    The major objectives of this study were two-fold. The first was to establish whether binding of platelet activating factor (PAF) to its receptor was integral to the stimulation of polyphosphoinositide-specific phospholipase C (PLC) in rabbit platelets. The second was to determine regulatory features of this receptor-coupled mechanism. [ 3 H]PAF binding demonstrated two binding sites, a high affinity site with a inhibitory constant (Ki) of 2.65 nM and a low affinity site with a Ki of 0.80 μM. PAF receptor coupled activation of phosphoinositide-specific PLC was studied in platelets which were made refractory, by short term pretreatments, to either PAF or thrombin. Saponin-permeabilized rabbit platelets continue to regulate the mechanism(s) coupling PAF receptors to PLC stimulation. However, TRPγS and GDPβS, which affect guanine nucleotide regulatory protein functions, were unable to modulate the PLC activity to any appreciable extent as compared to PAF. The possible involvement of protein kinase C (PKC) activation in regulating PAF-stimulated PLC activity was studied in rabbit platelets pretreated with staurosporine followed by pretreatments with PAF or phorbol 12-myristate 13-acetate (PMA)

  2. Role of LRRK2 in the regulation of dopamine receptor trafficking.

    Directory of Open Access Journals (Sweden)

    Mauro Rassu

    Full Text Available Mutations in LRRK2 play a critical role in both familial and sporadic Parkinson's disease (PD. Up to date, the role of LRRK2 in PD onset and progression remains largely unknown. However, experimental evidence highlights a critical role of LRRK2 in the control of vesicle trafficking that in turn may regulate different aspects of neuronal physiology. We have analyzed the role of LRRK2 in regulating dopamine receptor D1 (DRD1 and D2 (DRD2 trafficking. DRD1 and DRD2 are the most abundant dopamine receptors in the brain. They differ in structural, pharmacological and biochemical properties, as well as in localization and internalization mechanisms. Our results indicate that disease-associated mutant G2019S LRRK2 impairs DRD1 internalization, leading to an alteration in signal transduction. Moreover, the mutant forms of LRRK2 affect receptor turnover by decreasing the rate of DRD2 trafficking from the Golgi complex to the cell membrane. Collectively, our findings are consistent with the conclusion that LRRK2 influences the motility of neuronal vesicles and the neuronal receptor trafficking. These findings have important implications for the complex role that LRRK2 plays in neuronal physiology and the possible pathological mechanisms that may lead to neuronal death in PD.

  3. Cell-Autonomous Regulation of Mu-Opioid Receptor Recycling by Substance P

    Science.gov (United States)

    Bowman, Shanna L.; Soohoo, Amanda L.; Shiwarski, Daniel J.; Schulz, Stefan; Pradhan, Amynah A.; Puthenveedu, Manojkumar A.

    2015-01-01

    SUMMARY How neurons coordinate and reprogram multiple neurotransmitter signals is an area of broad interest. Here, we show that substance P (SP), a neuropep-tide associated with inflammatory pain, reprograms opioid receptor recycling and signaling. SP, through activation of the neurokinin 1 (NK1R) receptor, increases the post-endocytic recycling of the muopioid receptor (MOR) in trigeminal ganglion (TG) neurons in an agonist-selective manner. SP-mediated protein kinase C (PKC) activation is both required and sufficient for increasing recycling of exogenous and endogenous MOR in TG neurons. The target of this cross-regulation is MOR itself, given that mutation of either of two PKC phosphorylation sites on MOR abolishes the SP-induced increase in recycling and resensitization. Furthermore, SP enhances the resensitization of fentanyl-induced, but not morphine-induced, antinociception in mice. Our results define a physiological pathway that cross-regulates opioid receptor recycling via direct modification of MOR and suggest a mode of homeo-static interaction between the pain and analgesic systems. PMID:25801029

  4. Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model.

    Science.gov (United States)

    Casey, F P; Baird, D; Feng, Q; Gutenkunst, R N; Waterfall, J J; Myers, C R; Brown, K S; Cerione, R A; Sethna, J P

    2007-05-01

    We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incorporates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (beta -Pix) and the Rho family G protein Cdc42. The complex has been suggested to be important in disrupting receptor down-regulation. We demonstrate that the model interactions can accurately reproduce the experimental observations, that they can be used to make predictions with accompanying uncertainties, and that we can apply ideas of optimal experimental design to suggest new experiments that reduce the uncertainty on unmeasurable components of the system.

  5. Regulation of cytokine receptors by Golgi N-glycan processing and endocytosis.

    Science.gov (United States)

    Partridge, Emily A; Le Roy, Christine; Di Guglielmo, Gianni M; Pawling, Judy; Cheung, Pam; Granovsky, Maria; Nabi, Ivan R; Wrana, Jeffrey L; Dennis, James W

    2004-10-01

    The Golgi enzyme beta1,6 N-acetylglucosaminyltransferase V (Mgat5) is up-regulated in carcinomas and promotes the substitution of N-glycan with poly N-acetyllactosamine, the preferred ligand for galectin-3 (Gal-3). Here, we report that expression of Mgat5 sensitized mouse cells to multiple cytokines. Gal-3 cross-linked Mgat5-modified N-glycans on epidermal growth factor and transforming growth factor-beta receptors at the cell surface and delayed their removal by constitutive endocytosis. Mgat5 expression in mammary carcinoma was rate limiting for cytokine signaling and consequently for epithelial-mesenchymal transition, cell motility, and tumor metastasis. Mgat5 also promoted cytokine-mediated leukocyte signaling, phagocytosis, and extravasation in vivo. Thus, conditional regulation of N-glycan processing drives synchronous modification of cytokine receptors, which balances their surface retention against loss via endocytosis.

  6. Do cysteine residues regulate transient receptor potential canonical type 6 (TRPC6) channel protein expression?

    DEFF Research Database (Denmark)

    Thilo, Florian; Liu, Ying; Krueger, Katharina

    2012-01-01

    The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed that patie......The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed...... that patients with chronic renal failure had significantly elevated homocysteine levels and TRPC6 mRNA expression levels in monocytes compared to control subjects. We further observed that administration of homocysteine or acetylcysteine significantly increased TRPC6 channel protein expression compared...... to control conditions. We therefore hypothesize that cysteine residues increase TRPC6 channel protein expression in humans....

  7. Innate scavenger receptor-A regulates adaptive T helper cell responses to pathogen infection

    Science.gov (United States)

    Xu, Zhipeng; Xu, Lei; Li, Wei; Jin, Xin; Song, Xian; Chen, Xiaojun; Zhu, Jifeng; Zhou, Sha; Li, Yong; Zhang, Weiwei; Dong, Xiaoxiao; Yang, Xiaowei; Liu, Feng; Bai, Hui; Chen, Qi; Su, Chuan

    2017-01-01

    The pattern recognition receptor (PRR) scavenger receptor class A (SR-A) has an important function in the pathogenesis of non-infectious diseases and in innate immune responses to pathogen infections. However, little is known about the role of SR-A in the host adaptive immune responses to pathogen infection. Here we show with mouse models of helminth Schistosoma japonicum infection and heat-inactivated Mycobacterium tuberculosis stimulation that SR-A is regulated by pathogens and suppresses IRF5 nuclear translocation by direct interaction. Reduced abundance of nuclear IRF5 shifts macrophage polarization from M1 towards M2, which subsequently switches T-helper responses from type 1 to type 2. Our study identifies a role for SR-A as an innate PRR in regulating adaptive immune responses. PMID:28695899

  8. Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

    International Nuclear Information System (INIS)

    Zhang, Yu; Cheng, Jung-Chien; Huang, He-Feng; Leung, Peter C.K.

    2013-01-01

    Highlights: •HOXA7 regulates MCF7 cell proliferation. •HOXA7 up-regulates ERα expression. •HOXA7 mediates estrogen-induced MCF7 cell proliferation. -- Abstract: Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited. In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells

  9. Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou 310006 (China); Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 (Canada); Cheng, Jung-Chien [Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 (Canada); Huang, He-Feng, E-mail: huanghefg@hotmail.com [Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou 310006 (China); Leung, Peter C.K., E-mail: peter.leung@ubc.ca [Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou 310006 (China); Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 (Canada)

    2013-11-01

    Highlights: •HOXA7 regulates MCF7 cell proliferation. •HOXA7 up-regulates ERα expression. •HOXA7 mediates estrogen-induced MCF7 cell proliferation. -- Abstract: Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited. In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells.

  10. 5α-Bile alcohols function as farnesoid X receptor antagonists

    International Nuclear Information System (INIS)

    Nishimaki-Mogami, Tomoko; Kawahara, Yosuke; Tamehiro, Norimasa; Yoshida, Takemi; Inoue, Kazuhide; Ohno, Yasuo; Nagao, Taku; Une, Mizuho

    2006-01-01

    The farnesoid X receptor (FXR) is a bile acid/alcohol-activated nuclear receptor that regulates lipid homeostasis. Unlike other steroid receptors, FXR binds bile acids in an orientation that allows the steroid nucleus A to face helix 12 in the receptor, a crucial domain for coactivator-recruitment. Because most naturally occurring bile acids and alcohols contain a cis-oriented A, which is distinct from that of other steroids and cholesterol metabolites, we investigated the role of this 5β-configuration in FXR activation. The results showed that the 5β-(A/B cis) bile alcohols 5β-cyprinol and bufol are potent FXR agonists, whereas their 5α-(A/B trans) counterparts antagonize FXR transactivation and target gene expression. Both isomers bound to FXR, but their ability to induce coactivator-recruitment and thereby induce transactivation differed. These findings suggest a critical role for the A orientation of bile salts in agonist/antagonist function

  11. Vitamin D Receptor Negatively Regulates Bacterial-Stimulated NF-κB Activity in Intestine

    OpenAIRE

    Wu, Shaoping; Liao, Anne P.; Xia, Yinglin; Li, Yan Chun; Li, Jian-Dong; Sartor, R. Balfour; Sun, Jun

    2010-01-01

    Vitamin D receptor (VDR) plays an essential role in gastrointestinal inflammation. Most investigations have focused on the immune response; however, how bacteria regulate VDR and how VDR modulates the nuclear factor (NF)-κB pathway in intestinal epithelial cells remain unexplored. This study investigated the effects of VDR ablation on NF-κB activation in intestinal epithelia and the role of enteric bacteria on VDR expression. We found that VDR−/− mice exhibited a pro-inflammatory bias. After ...

  12. The Drosophila DHR96 nuclear receptor binds cholesterol and regulates cholesterol homeostasis

    OpenAIRE

    Horner, Michael A.; Pardee, Keith; Liu, Suya; King-Jones, Kirst; Lajoie, Gilles; Edwards, Aled; Krause, Henry M.; Thummel, Carl S.

    2009-01-01

    Cholesterol homeostasis is required to maintain normal cellular function and avoid the deleterious effects of hypercholesterolemia. Here we show that the Drosophila DHR96 nuclear receptor binds cholesterol and is required for the coordinate transcriptional response of genes that are regulated by cholesterol and involved in cholesterol uptake, trafficking, and storage. DHR96 mutants die when grown on low levels of cholesterol and accumulate excess cholesterol when maintained on a high-choleste...

  13. Small leucine zipper protein functions as a negative regulator of estrogen receptor α in breast cancer.

    Directory of Open Access Journals (Sweden)

    Juyeon Jeong

    Full Text Available The nuclear transcription factor estrogen receptor α (ERα plays a critical role in breast cancer progression. ERα acts as an important growth stimulatory protein in breast cancer and the expression level of ERα is tightly related to the prognosis and treatment of patients. Small leucine zipper protein (sLZIP functions as a transcriptional cofactor by binding to various nuclear receptors, including glucocorticoid receptor, androgen receptor, and peroxisome proliferator-activated receptor γ. However, the role of sLZIP in the regulation of ERα and its involvement in breast cancer progression is unknown. We found that sLZIP binds to ERα and represses the transcriptional activity of ERα in ERα-positive breast cancer cells. sLZIP also suppressed the expression of ERα target genes. sLZIP disrupted the binding of ERα to the estrogen response element of the target gene promoter, resulting in suppression of cell proliferation. sLZIP is a novel co-repressor of ERα, and plays a negative role in ERα-mediated cell proliferation in breast cancer.

  14. Expression and nutritional regulation of the (pro)renin receptor in rat visceral adipose tissue.

    Science.gov (United States)

    Achard, V; Tassistro, V; Boullu-Ciocca, S; Grino, M

    2011-12-01

    Early life nutritional environment plays an important role in the development of visceral adipose tissue and interacts with nutritional regulations in adulthood, leading to metabolic dysregulations. We hypothesized that the renin-angiotensin system may play a role in the programming-induced development of visceral adipose tissue. We studied, using a model of programming of overweight and glucose intolerance, obtained by post-natal overfeeding with consecutive highfat diet, the status of plasma renin activity and mesenteric adipose renin-angiotensin system, including the recently identified (pro)renin receptor, in adult rats. Post-natal overfeeding or high-fat feeding lead to overweight with increased visceral fat mass and adipocytes surface. When both paradigms were associated, adipocytes surface showed a disproportionate increase. A strong immunoreactivity for (pro)renin receptor was found in stromal cells. Plasma renin activity increased in programmed animals whereas (pro)renin receptor expressing cells density was stimulated by high-fat diet. There was a positive, linear relationship between plasma renin activity and (pro)renin receptor expressing cells density and adipocytes surface. Our experiments demonstrate that association of post-natal overfeeding and high-fat diet increased plasma renin activity and adipose (pro)renin receptor expression. Such phenomenon could explain, at least in part, the associated disproportionate adipocyte hypertrophy and its accompanying increased glucose intolerance.

  15. Therapeutic potential of α7 nicotinic receptor agonists to regulate neuroinflammation in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Laura Foucault-Fruchard

    2017-01-01

    Full Text Available Neurodegenerative diseases, such as Alzheimer's, Parkinson's and Huntington's diseases, are all characterized by a component of innate immunity called neuroinflammation. Neuronal loss and neuroinflammation are two phenomena closely linked. Hence, the neuroinflammation is a relevant target for the management of the neurodegenerative diseases given that, to date, there is no treatment to stop neuronal loss. Several studies have investigated the potential effects of activators of alpha 7 nicotinic acetylcholine receptors in animal models of neurodegenerative diseases. These receptors are widely distributed in the central nervous system. After activation, they seem to mediate the cholinergic anti-inflammatory pathway in the brain. This anti-inflammatory pathway, first described in periphery, regulates activation of microglial cells considered as the resident macrophage population of the central nervous system. In this article, we shortly review the agonists of the alpha 7 nicotinic acetylcholine receptors that have been evaluated in vivo and we focused on the selective positive allosteric modulators of these receptors. These compounds represent a key element to enhance receptor activity only in the presence of the endogenous agonist.

  16. Stargazin regulates AMPA receptor trafficking through adaptor protein complexes during long-term depression

    Science.gov (United States)

    Matsuda, Shinji; Kakegawa, Wataru; Budisantoso, Timotheus; Nomura, Toshihiro; Kohda, Kazuhisa; Yuzaki, Michisuke

    2013-11-01

    Long-term depression (LTD) underlies learning and memory in various brain regions. Although postsynaptic AMPA receptor trafficking mediates LTD, its underlying molecular mechanisms remain largely unclear. Here we show that stargazin, a transmembrane AMPA receptor regulatory protein, forms a ternary complex with adaptor proteins AP-2 and AP-3A in hippocampal neurons, depending on its phosphorylation state. Inhibiting the stargazin-AP-2 interaction disrupts NMDA-induced AMPA receptor endocytosis, and inhibiting that of stargazin-AP-3A abrogates the late endosomal/lysosomal trafficking of AMPA receptors, thereby upregulating receptor recycling to the cell surface. Similarly, stargazin’s interaction with AP-2 or AP-3A is necessary for low-frequency stimulus-evoked LTD in CA1 hippocampal neurons. Thus, stargazin has a crucial role in NMDA-dependent LTD by regulating two trafficking pathways of AMPA receptors—transport from the cell surface to early endosomes and from early endosomes to late endosomes/lysosomes—through its sequential binding to AP-2 and AP-3A.

  17. Communication over the network of binary switches regulates the activation of A2A adenosine receptor.

    Directory of Open Access Journals (Sweden)

    Yoonji Lee

    2015-02-01

    Full Text Available Dynamics and functions of G-protein coupled receptors (GPCRs are accurately regulated by the type of ligands that bind to the orthosteric or allosteric binding sites. To glean the structural and dynamical origin of ligand-dependent modulation of GPCR activity, we performed total ~ 5 μsec molecular dynamics simulations of A2A adenosine receptor (A2AAR in its apo, antagonist-bound, and agonist-bound forms in an explicit water and membrane environment, and examined the corresponding dynamics and correlation between the 10 key structural motifs that serve as the allosteric hotspots in intramolecular signaling network. We dubbed these 10 structural motifs "binary switches" as they display molecular interactions that switch between two distinct states. By projecting the receptor dynamics on these binary switches that yield 2(10 microstates, we show that (i the receptors in apo, antagonist-bound, and agonist-bound states explore vastly different conformational space; (ii among the three receptor states the apo state explores the broadest range of microstates; (iii in the presence of the agonist, the active conformation is maintained through coherent couplings among the binary switches; and (iv to be most specific, our analysis shows that W246, located deep inside the binding cleft, can serve as both an agonist sensor and actuator of ensuing intramolecular signaling for the receptor activation. Finally, our analysis of multiple trajectories generated by inserting an agonist to the apo state underscores that the transition of the receptor from inactive to active form requires the disruption of ionic-lock in the DRY motif.

  18. α5-GABAA receptors negatively regulate MYC-amplified medulloblastoma growth

    Science.gov (United States)

    Sengupta, Soma; Weeraratne, Shyamal Dilhan; Sun, Hongyu; Phallen, Jillian; Rallapalli, Sundari K.; Teider, Natalia; Kosaras, Bela; Amani, Vladimir; Pierre-Francois, Jessica; Tang, Yujie; Nguyen, Brian; Yu, Furong; Schubert, Simone; Balansay, Brianna; Mathios, Dimitris; Lechpammer, Mirna; Archer, Tenley C.; Tran, Phuoc; Reimer, Richard J.; Cook, James M.; Lim, Michael; Jensen, Frances E.; Pomeroy, Scott L.; Cho, Yoon-Jae

    2013-01-01

    Neural tumors often express neurotransmitter receptors as markers of their developmental lineage. Although these receptors have been well characterized in electrophysiological, developmental and pharmacological settings, their importance in the maintenance and progression of brain tumors, and importantly, the effect of their targeting in brain cancers remains obscure. Here, we demonstrate high levels of GABR5, which encodes the α-subunit of the GABAA receptor complex, in aggressive MYC-driven, “Group 3” medulloblastomas. We hypothesized that modulation of α-GABAA receptors alters medulloblastoma cell survival and monitored biological and electrophysiological responses of GABR5-expressing medulloblastoma cells upon pharmacological targeting of the GABAA receptor. While antagonists, inverse agonists and non-specific positive allosteric modulators had limited effects on medulloblastoma cells, a highly specific and potent α5-GABAA receptor agonist, QHii066, resulted in marked membrane depolarization and a significant decrease in cell survival. This effect was GABR5 dependent and mediated through the induction of apoptosis as well as accumulation of cells in S and G2 phases of the cell cycle. Chemical genomic profiling of QHii066-treated medulloblastoma cells confirmed inhibition of MYC-related transcriptional activity and revealed an enrichment of HOX5 target gene expression. siRNA-mediated knockdown of HOX5 markedly blunted the response of medulloblastoma cells to QHii066. Furthermore, QHii066 sensitized GABR5 positive medulloblastoma cells to radiation and chemotherapy consistent with the role of HOX5 in directly regulating p53 expression and inducing apoptosis. Thus, our results provide novel insights into the synthetic lethal nature of α5-GABAA receptor activation in MYC-driven/Group 3 medulloblastomas and propose its targeting as a novel strategy for the management of this highly aggressive tumor. PMID:24196163

  19. γ-Aminobutyric Acid Type B (GABAB) Receptor Internalization Is Regulated by the R2 Subunit*

    Science.gov (United States)

    Hannan, Saad; Wilkins, Megan E.; Dehghani-Tafti, Ebrahim; Thomas, Philip; Baddeley, Stuart M.; Smart, Trevor G.

    2011-01-01

    γ-Aminobutyric acid type B (GABAB) receptors are important for slow synaptic inhibition in the CNS. The efficacy of inhibition is directly related to the stability of cell surface receptors. For GABAB receptors, heterodimerization between R1 and R2 subunits is critical for cell surface expression and signaling, but how this determines the rate and extent of receptor internalization is unknown. Here, we insert a high affinity α-bungarotoxin binding site into the N terminus of the R2 subunit and reveal its dominant role in regulating the internalization of GABAB receptors in live cells. To simultaneously study R1a and R2 trafficking, a new α-bungarotoxin binding site-labeling technique was used, allowing α-bungarotoxin conjugated to different fluorophores to selectively label R1a and R2 subunits. This approach demonstrated that R1a and R2 are internalized as dimers. In heterologous expression systems and neurons, the rates and extents of internalization for R1aR2 heteromers and R2 homomers are similar, suggesting a regulatory role for R2 in determining cell surface receptor stability. The fast internalization rate of R1a, which has been engineered to exit the endoplasmic reticulum, was slowed to that of R2 by truncating the R1a C-terminal tail or by removing a dileucine motif in its coiled-coil domain. Slowing the rate of internalization by co-assembly with R2 represents a novel role for GPCR heterodimerization whereby R2 subunits, via their C terminus coiled-coil domain, mask a dileucine motif on R1a subunits to determine the surface stability of the GABAB receptor. PMID:21724853

  20. α5-GABAA receptors negatively regulate MYC-amplified medulloblastoma growth.

    Science.gov (United States)

    Sengupta, Soma; Weeraratne, Shyamal Dilhan; Sun, Hongyu; Phallen, Jillian; Rallapalli, Sundari K; Teider, Natalia; Kosaras, Bela; Amani, Vladimir; Pierre-Francois, Jessica; Tang, Yujie; Nguyen, Brian; Yu, Furong; Schubert, Simone; Balansay, Brianna; Mathios, Dimitris; Lechpammer, Mirna; Archer, Tenley C; Tran, Phuoc; Reimer, Richard J; Cook, James M; Lim, Michael; Jensen, Frances E; Pomeroy, Scott L; Cho, Yoon-Jae

    2014-04-01

    Neural tumors often express neurotransmitter receptors as markers of their developmental lineage. Although these receptors have been well characterized in electrophysiological, developmental and pharmacological settings, their importance in the maintenance and progression of brain tumors and, importantly, the effect of their targeting in brain cancers remains obscure. Here, we demonstrate high levels of GABRA5, which encodes the α5-subunit of the GABAA receptor complex, in aggressive MYC-driven, "Group 3" medulloblastomas. We hypothesized that modulation of α5-GABAA receptors alters medulloblastoma cell survival and monitored biological and electrophysiological responses of GABRA5-expressing medulloblastoma cells upon pharmacological targeting of the GABAA receptor. While antagonists, inverse agonists and non-specific positive allosteric modulators had limited effects on medulloblastoma cells, a highly specific and potent α5-GABAA receptor agonist, QHii066, resulted in marked membrane depolarization and a significant decrease in cell survival. This effect was GABRA5 dependent and mediated through the induction of apoptosis as well as accumulation of cells in S and G2 phases of the cell cycle. Chemical genomic profiling of QHii066-treated medulloblastoma cells confirmed inhibition of MYC-related transcriptional activity and revealed an enrichment of HOXA5 target gene expression. siRNA-mediated knockdown of HOXA5 markedly blunted the response of medulloblastoma cells to QHii066. Furthermore, QHii066 sensitized GABRA5 positive medulloblastoma cells to radiation and chemotherapy consistent with the role of HOXA5 in directly regulating p53 expression and inducing apoptosis. Thus, our results provide novel insights into the synthetic lethal nature of α5-GABAA receptor activation in MYC-driven/Group 3 medulloblastomas and propose its targeting as a novel strategy for the management of this highly aggressive tumor.

  1. The role of steroids in the management of uveitic macular edema

    NARCIS (Netherlands)

    de Smet, Marc D.; Julian, Karina

    2010-01-01

    Purpose. To review the role of steroids in the management of uveitic macular edema. Methods. Review of recent literature on the physiopathology of macular edema and clinical trials involving steroids as main treatment of uveitic macular edema. Results. The steroid-glucocorticoid receptor complex

  2. Involvement of 1,25D{sub 3}-MARRS (membrane associated, rapid response steroid-binding), a novel vitamin D receptor, in growth inhibition of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Richard, Cynthia L. [Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G2W1 (Canada); Farach-Carson, Mary C.; Rohe, Ben [Department of Biological Sciences, University of Delaware, Newark, DE 19716 (United States); Nemere, Ilka [Department of Nutrition and Food Sciences, Center for Integrated BioSystems, Utah State University, Logan, UT 84322 8700 (United States); Meckling, Kelly A., E-mail: kmecklin@uoguelph.ca [Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G2W1 (Canada)

    2010-03-10

    In addition to classical roles in calcium homeostasis and bone development, 1,25 dihydroxyvitamin D{sub 3} [1,25(OH){sub 2}D{sub 3}] inhibits the growth of several cancer types, including breast cancer. Although cellular effects of 1,25(OH){sub 2}D{sub 3} traditionally have been attributed to activation of a nuclear vitamin D receptor (VDR), a novel receptor for 1,25(OH){sub 2}D{sub 3} called 1,25D{sub 3}-MARRS (membrane-associated, rapid response steroid-binding) protein was identified recently. The purpose of this study was to determine if the level of 1,25D{sub 3}-MARRS expression modulates 1,25(OH){sub 2}D{sub 3} activity in breast cancer cells. Relative levels of 1,25D{sub 3}-MARRS protein in MCF-7, MDA MB 231, and MCF-10A cells were estimated by real-time RT-PCR and Western blotting. To determine if 1,25D{sub 3}-MARRS receptor was involved in the growth inhibitory effects of 1,25(OH){sub 2}D{sub 3} in MCF-7 cells, a ribozyme construct designed to knock down 1,25D{sub 3}-MARRS mRNA was stably transfected into MCF-7 cells. MCF-7 clones in which 1,25D{sub 3}-MARRS receptor expression was reduced showed increased sensitivity to 1,25(OH){sub 2}D{sub 3} ( IC{sub 50} 56 {+-} 24 nM) compared to controls (319 {+-} 181 nM; P < 0.05). Reduction in 1,25D{sub 3}-MARRS receptor lengthened the doubling time in transfectants treated with 1,25(OH){sub 2}D{sub 3}. Knockdown of 1,25D{sub 3}-MARRS receptor also increased the sensitivity of MCF-7 cells to the vitamin D analogs KH1060 and MC903, but not to unrelated agents (all-trans retinoic acid, paclitaxel, serum/glucose starvation, or the isoflavone, pomiferin). These results suggest that 1,25D{sub 3}-MARRS receptor expression interferes with the growth inhibitory activity of 1,25(OH){sub 2}D{sub 3} in breast cancer cells, possibly through the nuclear VDR. Further research should examine the potential for pharmacological or natural agents that modify 1,25D{sub 3}-MARRS expression or activity as anticancer agents.

  3. Extracellular and intracellular steroid binding proteins

    International Nuclear Information System (INIS)

    Wagner, R.K.

    1978-01-01

    Steroid hormone binding proteins can be measured, after the removal of endogenous steroids, as specific complexes with radio-labelled hormones. In this study all the requirements for a quantitative determination of steroid hormone binding proteins are defined. For different methods, agargel electrophoresis, density gradient centrifugation, equilibrium dialysis and polyacrylamide electrophoresis have been evaluated. Agar electrophoresis at low temperature was found to be the simplest and most useful procedure. With this method the dissociation rates of high affinity complexes can be assessed and absolute binding protein concentrations can be determined. The dissociation rates of the oestradiol-oestrogen receptor complex and the R-5020-progestin receptor complex are low (1-2% per h run time.) In contrast, that of complexes between androgen receptor and dihydrotestosterone (17β-hydroxy-5α-androstan-3-one (DHT), progestin receptor and progesterone, corticosteroid binding globulin (CBG) and cortisol or progesterone and sex hormone binding globulin (SHBG) and DHT were hign (16-27% per h run time). Target tissue extracts (cytosols) contain, besides soluble tissue proteins, large amounts of plasma proteins. The extent of this plasma contamination can be determined by measuring the albumin concentration in cytosols by immunodiffusion. In cytosols of 4 different human target tissues the albumin content varied from 20-30% corresponding to an even higher whole plasma concentration. Steroid binding plasma proteins, such as CBG and SHBG are constituents of this containment. (author)

  4. The effects of black cohosh on the regulation of estrogen receptor (ERα) and progesterone receptor (PR) in breast cancer cells.

    Science.gov (United States)

    Szmyd, Monica; Lloyd, Victoria; Hallman, Kelly; Aleck, Katie; Mladenovik, Viktoria; McKee, Christina; Morse, Mia; Bedgood, Tyler; Dinda, Sumi

    2018-01-01

    The North American plant Cimicifuga racemosa , also known as black cohosh (BC), is a herb that recently has gained attention for its hormonal effects. As the usage of hormone replacement therapy is declining due to its adverse effects in women with cancer, many are turning to herbal remedies like BC to treat menopausal symptoms. It is crucial to determine whether the effects of BC involve estrogen receptor-alpha (ERα). Previous studies from our laboratory have shown ERα to be a possible molecular target for BC. In this study, we examined the effects of BC (8% triterpene glycosides) alone and in combination with hormones and antihormones on the cellular viability, expression of ERα and progesterone receptor (PR)-A/B, and cytolocalization of ERα in ER (+) and PR-A/B (+) T-47D breast cancer cells. Cells were cultured and proteins were extracted and quantified. Western blot analysis revealed alterations in the expression of ERα and PR after treatment with BC (5-100 µM). BC induced a concentration-dependent decrease in ERα and PR protein levels when compared to the control. Image cytometric analysis with propidium iodide staining was used to enumerate changes in T-47D cell number and viability. A decrease in T-47D cell viability was observed upon treatment with 5-100 µM BC. The ideal concentration of BC (100 µM) was used in combination with hormones and antihormones in an effort to further understand the possible similarities between this compound and other known effectors of ERα and PR. After a 24-hour concomitant treatment with and/or in combination of BC, estradiol, ICI 182, 780, and Tamoxifen, downregulation of ERα and PR protein levels was observed. Delineating the role of BC in the regulation of ERα, PR, as well as its mechanisms of action, may be important in understanding the influence of BC on hormone receptors in breast cancer.

  5. Regulation of CYP3A4 by pregnane X receptor: The role of nuclear receptors competing for response element binding

    Energy Technology Data Exchange (ETDEWEB)

    Istrate, Monica A., E-mail: monicai@scripps.edu [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany); Nussler, Andreas K., E-mail: nuessler@uchir.me.tum.de [Department of Traumatology, Technical University Munich, Ismaningerstr. 22, 81675 Munich (Germany); Eichelbaum, Michel, E-mail: michel.eichelbaum@ikp-stuttgart.de [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany); Burk, Oliver, E-mail: oliver.burk@ikp-stuttgart.de [Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany, and University of Tuebingen, Auerbachstr. 112, D-70376 Stuttgart (Germany)

    2010-03-19

    Induction of the major drug metabolizing enzyme CYP3A4 by xenobiotics contributes to the pronounced interindividual variability of its expression and often results in clinically relevant drug-drug interactions. It is mainly mediated by PXR, which regulates CYP3A4 expression by binding to several specific elements in the 5' upstream regulatory region of the gene. Induction itself shows a marked interindividual variability, whose underlying determinants are only partly understood. In this study, we investigated the role of nuclear receptor binding to PXR response elements in CYP3A4, as a potential non-genetic mechanism contributing to interindividual variability of induction. By in vitro DNA binding experiments, we showed that several nuclear receptors bind efficiently to the proximal promoter ER6 and distal xenobiotic-responsive enhancer module DR3 motifs. TR{alpha}1, TR{beta}1, COUP-TFI, and COUP-TFII further demonstrated dose-dependent repression of PXR-mediated CYP3A4 enhancer/promoter reporter activity in transient transfection in the presence and absence of the PXR inducer rifampin, while VDR showed this effect only in the absence of treatment. By combining functional in vitro characterization with hepatic expression analysis, we predict that TR{alpha}1, TR{beta}1, COUP-TFI, and COUP-TFII show a strong potential for the repression of PXR-mediated activation of CYP3A4 in vivo. In summary, our results demonstrate that nuclear receptor binding to PXR response elements interferes with PXR-mediated expression and induction of CYP3A4 and thereby contributes to the interindividual variability of induction.

  6. Wnt5a regulates hematopoietic stem cell proliferation and repopulation through the Ryk receptor.

    Science.gov (United States)

    Povinelli, Benjamin J; Nemeth, Michael J

    2014-01-01

    Proper regulation of the balance between hematopoietic stem cell (HSC) proliferation, self-renewal, and differentiation is necessary to maintain hematopoiesis throughout life. The Wnt family of ligands has been implicated as critical regulators of these processes through a network of signaling pathways. Previously, we have demonstrated that the Wnt5a ligand can induce HSC quiescence through a noncanonical Wnt pathway, resulting in an increased ability to reconstitute hematopoiesis. In this study, we tested the hypothesis that the Ryk protein, a Wnt ligand receptor that can bind the Wnt5a ligand, regulated the response of HSCs to Wnt5a. We observed that inhibiting Ryk blocked the ability of Wnt5a to induce HSC quiescence and enhance short-term and long-term hematopoietic repopulation. We found that Wnt5a suppressed production of reactive oxygen species, a known inducer of HSC proliferation. The ability of Wnt5a to inhibit ROS production was also regulated by Ryk. From these data, we propose that Wnt5a regulates HSC quiescence and hematopoietic repopulation through the Ryk receptor and that this process is mediated by suppression of reactive oxygen species. © 2013 AlphaMed Press.

  7. β-Adrenergic Receptors Regulate the Acquisition and Consolidation Phases of Aversive Memory Formation Through Distinct, Temporally Regulated Signaling Pathways.

    Science.gov (United States)

    Schiff, Hillary C; Johansen, Joshua P; Hou, Mian; Bush, David E A; Smith, Emily K; Klein, JoAnna E; LeDoux, Joseph E; Sears, Robert M

    2017-03-01

    Memory formation requires the temporal coordination of molecular events and cellular processes following a learned event. During Pavlovian threat (fear) conditioning (PTC), sensory and neuromodulatory inputs converge on post-synaptic neurons within the lateral nucleus of the amygdala (LA). By activating an intracellular cascade of signaling molecules, these G-protein-coupled neuromodulatory receptors are capable of recruiting a diverse profile of plasticity-related proteins. Here we report that norepinephrine, through its actions on β-adrenergic receptors (βARs), modulates aversive memory formation following PTC through two molecularly and temporally distinct signaling mechanisms. Specifically, using behavioral pharmacology and biochemistry in adult rats, we determined that βAR activity during, but not after PTC training initiates the activation of two plasticity-related targets: AMPA receptors (AMPARs) for memory acquisition and short-term memory and extracellular regulated kinase (ERK) for consolidating the learned association into a long-term memory. These findings reveal that βAR activity during, but not following PTC sets in motion cascading molecular events for the acquisition (AMPARs) and subsequent consolidation (ERK) of learned associations.

  8. Differential regulation of dopamine receptors after chronic typical and atypical antipsychotic drug treatment

    Energy Technology Data Exchange (ETDEWEB)

    Creese, I; Florijn, W J; Tarazi, F I [Center for Molecular and Behavioral Neuroscience, Rutgers University, 197 University Avenue, Newark, NJ (United States)

    1997-04-14

    Changes in dopamine receptor subtype binding in different brain regions were examined after 28 days treatment of rats with haloperidol, raclopride, clozapine or SCH23390 using in vitro receptor autoradiography. [{sup 3}H]7-hydroxy-N,N-di-n-propyl-2-aminotetralin binding to dopamine D{sub 3} receptors was not changed in any brain region by any of the drug treatments. [{sup 3}H]SCH23390 was only increased by chronic SCH23390 treatment. Haloperidol significantly increased [{sup 3}H]nemonapride and [{sup 3}H]spiperone binding to dopamine D{sub 2}-like receptors in the caudate-putamen. In contrast, haloperidol caused a small, significant increase in [{sup 3}H]raclopride binding in the lateral caudate-putamen only. Raclopride also elevated, but to a lesser extent [{sup 3}H]nemonapride and [{sup 3}H]spiperone binding in caudate-putamen, whereas it did not affect [{sup 3}H]raclopride binding. Clozapine did not significantly change D{sub 2}-like striatal binding of [{sup 3}H]nemonapride, [{sup 3}H]spiperone or [{sup 3}H]raclopride. The differences in radioligand binding suggest that [{sup 3}H]nemonapride and [{sup 3}H]spiperone may be binding to additional subsets of dopamine D{sub 2}-like receptors (including D{sub 4}-like receptors) that are not recognized by [{sup 3}H]raclopride, which has high affinity for D{sub 2} and D{sub 3} receptors only.Quantification of [{sup 3}H]nemonapride or [{sup 3}H]spiperone binding in the presence of 300 nM raclopride (to block D{sub 2} and D{sub 3} receptors) revealed that haloperidol, raclopride and clozapine up-regulated D{sub 4}-like receptors in the caudate-putamen using either radioligand. These results suggest that D{sub 4}-like receptors may be a common site of action of both typical and atypical antipsychotics. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Positive regulation of raphe serotonin neurons by serotonin 2B receptors.

    Science.gov (United States)

    Belmer, Arnauld; Quentin, Emily; Diaz, Silvina L; Guiard, Bruno P; Fernandez, Sebastian P; Doly, Stéphane; Banas, Sophie M; Pitychoutis, Pothitos M; Moutkine, Imane; Muzerelle, Aude; Tchenio, Anna; Roumier, Anne; Mameli, Manuel; Maroteaux, Luc

    2018-06-01

    Serotonin is a neurotransmitter involved in many psychiatric diseases. In humans, a lack of 5-HT 2B receptors is associated with serotonin-dependent phenotypes, including impulsivity and suicidality. A lack of 5-HT 2B receptors in mice eliminates the effects of molecules that directly target serotonergic neurons including amphetamine derivative serotonin releasers, and selective serotonin reuptake inhibitor antidepressants. In this work, we tested the hypothesis that 5-HT 2B receptors directly and positively regulate raphe serotonin neuron activity. By ex vivo electrophysiological recordings, we report that stimulation by the 5-HT 2B receptor agonist, BW723C86, increased the firing frequency of serotonin Pet1-positive neurons. Viral overexpression of 5-HT 2B receptors in these neurons increased their excitability. Furthermore, in vivo 5-HT 2B -receptor stimulation by BW723C86 counteracted 5-HT 1A autoreceptor-dependent reduction in firing rate and hypothermic response in wild-type mice. By a conditional genetic ablation that eliminates 5-HT 2B receptor expression specifically and exclusively from Pet1-positive serotonin neurons (Htr2b 5-HTKO mice), we demonstrated that behavioral and sensitizing effects of MDMA (3,4-methylenedioxy-methamphetamine), as well as acute behavioral and chronic neurogenic effects of the antidepressant fluoxetine, require 5-HT 2B receptor expression in serotonergic neurons. In Htr2b 5-HTKO mice, dorsal raphe serotonin neurons displayed a lower firing frequency compared to control Htr2b lox/lox mice as assessed by in vivo extracellular recordings and a stronger hypothermic effect of 5-HT 1A -autoreceptor stimulation was observed. The increase in head-twitch response to DOI (2,5-dimethoxy-4-iodoamphetamine) further confirmed the lower serotonergic tone resulting from the absence of 5-HT 2B receptors in serotonin neurons. Together, these observations indicate that the 5-HT 2B receptor acts as a direct positive modulator of serotonin Pet1

  10. Identification and Transcriptional Modulation of the Largemouth Bass, Micropterus salmoides, Vitellogenin Receptor During Oocyte Development by Insulin and Sex Steroids1

    OpenAIRE

    Dominguez, Gustavo A.; Quattro, Joseph M.; Denslow, Nancy D.; Kroll, Kevin J.; Prucha, Melinda S.; Porak, Wesley F.; Grier, Harry J.; Sabo-Attwood, Tara L.

    2012-01-01

    Fish vitellogenin synthesized and released from the liver of oviparous animals is taken up into oocytes by the vitellogenin receptor. This is an essential process in providing nutrient yolk to developing embryos to ensure successful reproduction. Here we disclose the full length vtgr cDNA sequence for largemouth bass (LMB) that reveals greater than 90% sequence homology with other fish vtgr sequences. We classify LMB Vtgr as a member of the low density lipoprotein receptor superfamily based o...

  11. Steroid influences on GABAergic neurotransmission: A behavioral and biochemical approach

    International Nuclear Information System (INIS)

    McCarthy, M.M.

    1989-01-01

    Steroid influences on GABAergic neurotransmission are varied and complex. However, there has been little investigation into the behavioral relevance of steroid effects on GABA. GABA had been implicated in the control of lordosis, a steroid dependent posture exhibited by sexually receptive female rats, but with conflicting results. This data demonstrated that GABA plays a dual role in the regulation of lordosis; stimulation of GABAergic transmission in the medial hypothalamus enhances lordosis whereas stimulation of GABA in the preoptic area inhibits lordosis. In separate experiments it was determined that progesterone enhances binding of the GABA A agonist, muscimol, in an in vitro exchange assay utilizing synaptic membranes prepared from the hypothalamus of ovariectomized rats. Scatchard analysis revealed a difference in affinity of the GABA A receptor between ovariectomized, receptive and post receptive females. In the preoptic area there was a significant decrease in the binding of 3 H-muscimol in receptive females versus post-receptive and ovariectomized rats. In other behavioral experiments, the influence of estrogen and progesterone on GABA-induced analgesia was assessed. Intrathecal infusion of a low dose of muscimol at the lumbar level of the spinal cord did not alter nociceptive thresholds in ovariectomized rats. However, when intact females were administered the same dose of muscimol, they exhibited differential responses over the estrous cycle. Females in estrus were analgesic after muscimol, whereas diestrus females did not differ from ovariectomized controls. Ovariectomized rats injected s.c. with progesterone (2mg) exhibited a pronounced analgesia after intrathecal muscimol beginning 15 minutes after steroid treatment, whereas similar treatment with estrogen (10ug) was without effect

  12. Cellular and behavioural effects of a new steroidal inhibitor of the N-methyl-d-aspartate receptor 3α5β-pregnanolone glutamate

    Czech Academy of Sciences Publication Activity Database

    Rambousek, Lukáš; Bubeníková-Valešová, V.; Kačer, P.; Syslová, K.; Kenney, Jana; Holubová, Kristína; Najmanová, V.; Zach, P.; Svoboda, Jan; Stuchlík, Aleš; Chodounská, Hana; Kapras, Vojtěch; Adamusová, Eva; Borovská, Jiřina; Vyklický ml., Ladislav; Valeš, Karel

    2011-01-01

    Roč. 61, 1-2 (2011), s. 61-68 ISSN 0028-3908 R&D Projects: GA MZd(CZ) NS10365; GA MZd(CZ) NR9180; GA ČR(CZ) GA309/07/0271; GA ČR(CZ) GA203/08/1498; GA ČR(CZ) GA309/09/0286; GA MŠk(CZ) 1M0517; GA MŠk(CZ) LC554 Grant - others:EC(XE) LSMH-CT-2007-037765 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40550506 Keywords : neuroactive steroid * NMDA * neuroprotectivity Subject RIV: FH - Neurology Impact factor: 4.814, year: 2011

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

    Directory of Open Access Journals (Sweden)

    Emi Ishida

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

  14. Regulation of formyl peptide receptor binding to rabbit neutrophil plasma membranes. Use of monovalent cations, guanine nucleotides, and bacterial toxins to discriminate among different states of the receptor

    International Nuclear Information System (INIS)

    Feltner, D.E.; Marasco, W.A.

    1989-01-01

    The regulation by monovalent cations, guanine nucleotides, and bacterial toxins of [3H]FMLP binding to rabbit neutrophil plasma membranes was studied by using dissociation techniques to identify regulatory effects on separate receptor states. Under conditions of low receptor occupancy (1 nM [3H]FMLP) and in both Na+ and K+ buffers, dissociation is heterogenous, displaying two distinct, statistically significant off rates. [3H]FMLP binding was enhanced by substituting other monovalent cations for Na+. In particular, enhanced binding in the presence of K+ relative to Na+ was caused by additional binding to both rapidly and slowly dissociating receptors. Three receptor dissociation rates, two of which appear to correspond to the two affinity states detected in equilibrium binding studies, were defined by specific GTP and pertussis toxin (PT) treatments. Neither GTP, nor PT or cholera toxins (CT) had an effect on the rate of dissociation of [3H]FMLP from the rapidly dissociating form of the receptor. Both 100 microM GTP and PT treatments increased the percentage of rapidly dissociating receptors, correspondingly decreasing the percentage of slowly dissociating receptors. The observed changes in the rapidly and slowly dissociating receptors after GTP, PT, and CT treatments were caused by an absolute decrease in the amount of binding to the slowly dissociating receptors. However, complete inhibition of slowly dissociating receptor binding by GTP, PT, or both was never observed. Both GTP and PT treatments, but not CT treatment, increased by two-fold the rate of dissociation of 1 nM [3H]FMLP from the slowly dissociating form of the receptor, resulting in a third dissociation rate. Thus, slowly dissociating receptors comprise two different receptor states, a G protein-associated guanine nucleotide and PT-sensitive state and a guanine nucleotide-insensitive state

  15. Endogenous GAS6 and Mer receptor signaling regulate prostate cancer stem cells in bone marrow.

    Science.gov (United States)

    Jung, Younghun; Decker, Ann M; Wang, Jingcheng; Lee, Eunsohl; Kana, Lulia A; Yumoto, Kenji; Cackowski, Frank C; Rhee, James; Carmeliet, Peter; Buttitta, Laura; Morgan, Todd M; Taichman, Russell S

    2016-05-03

    GAS6 and its receptors (Tryo 3, Axl, Mer or "TAM") are known to play a role in regulating tumor progression in a number of settings. Previously we have demonstrated that GAS6 signaling regulates invasion, proliferation, chemotherapy-induced apoptosis of prostate cancer (PCa) cells. We have also demonstrated that GAS6 secreted from osteoblasts in the bone marrow environment plays a critical role in establishing prostate tumor cell dormancy. Here we investigated the role that endogenous GAS6 and Mer receptor signaling plays in establishing prostate cancer stem cells in the bone marrow microenvironment.We first observed that high levels of endogenous GAS6 are expressed by disseminated tumor cells (DTCs) in the bone marrow, whereas relatively low levels of endogenous GAS6 are expressed in PCa tumors grown in a s.c. Interestingly, elevated levels of endogenous GAS6 were identified in putative cancer stem cells (CSCs, CD133+/CD44+) compared to non-CSCs (CD133-/CD44-) isolated from PCa/osteoblast cocultures in vitro and in DTCs isolated from the bone marrow 24 hours after intracardiac injection. Moreover, we found that endogenous GAS6 expression is associated with Mer receptor expression in growth arrested (G1) PCa cells, which correlates with the increase of the CSC populations. Importantly, we found that overexpression of GAS6 activates phosphorylation of Mer receptor signaling and subsequent induction of the CSC phenotype in vitro and in vivo.Together these data suggest that endogenous GAS6 and Mer receptor signaling contribute to the establishment of PCa CSCs in the bone marrow microenvironment, which may have important implications for targeting metastatic disease.

  16. Ly49Q, an ITIM-bearing NK receptor, positively regulates osteoclast differentiation

    International Nuclear Information System (INIS)

    Hayashi, Mikihito; Nakashima, Tomoki; Kodama, Tatsuhiko; Makrigiannis, Andrew P.; Toyama-Sorimachi, Noriko; Takayanagi, Hiroshi

    2010-01-01

    Osteoclasts, multinucleated cells that resorb bone, play a key role in bone remodeling. Although immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling is critical for osteoclast differentiation, the significance of immunoreceptor tyrosine-based inhibitory motif (ITIM) has not been well understood. Here we report the function of Ly49Q, an Ly49 family member possessing an ITIM motif, in osteoclastogenesis. Ly49Q is selectively induced by receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) stimulation in bone marrow-derived monocyte/macrophage precursor cells (BMMs) among the Ly49 family of NK receptors. The knockdown of Ly49Q resulted in a significant reduction in the RANKL-induced formation of tartrate-resistance acid phosphatase (TRAP)-positive multinucleated cells, accompanied by a decreased expression of osteoclast-specific genes such as Nfatc1, Tm7sf4, Oscar, Ctsk, and Acp5. Osteoclastogenesis was also significantly impaired in Ly49Q-deficient cells in vitro. The inhibitory effect of Ly49Q-deficiency may be explained by the finding that Ly49Q competed for the association of Src-homology domain-2 phosphatase-1 (SHP-1) with paired immunoglobulin-like receptor-B (PIR-B), an ITIM-bearing receptor which negatively regulates osteoclast differentiation. Unexpectedly, Ly49Q deficiency did not lead to impaired osteoclast formation in vivo, suggesting the existence of a compensatory mechanism. This study provides an example in which an ITIM-bearing receptor functions as a positive regulator of osteoclast differentiation.

  17. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling.

    Science.gov (United States)

    Miller, Eileen; Czopek, Alicja; Duthie, Karolina M; Kirkby, Nicholas S; van de Putte, Elisabeth E Fransen; Christen, Sibylle; Kimmitt, Robert A; Moorhouse, Rebecca; Castellan, Raphael F P; Kotelevtsev, Yuri V; Kuc, Rhoda E; Davenport, Anthony P; Dhaun, Neeraj; Webb, David J; Hadoke, Patrick W F

    2017-02-01

    The role of smooth muscle endothelin B (ET B ) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ET B receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ET B receptors were selectively deleted from smooth muscle by crossing floxed ET B mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ET B deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ET B was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ET B -mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ET B -mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ET B knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ET B blockade-mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ET B -mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ET B knockout mice. In the absence of other pathology, ET B receptors in vascular smooth muscle make a small but significant contribution to ET B -dependent regulation of BP. These ET B receptors have no effect on vascular contraction or neointimal remodeling. © 2016 The Authors.

  18. Deciphering the regulation of P2X4 receptor channel gating by ivermectin using Markov models.

    Directory of Open Access Journals (Sweden)

    Laurent Mackay

    2017-07-01

    Full Text Available The P2X4 receptor (P2X4R is a member of a family of purinergic channels activated by extracellular ATP through three orthosteric binding sites and allosterically regulated by ivermectin (IVM, a broad-spectrum antiparasitic agent. Treatment with IVM increases the efficacy of ATP to activate P2X4R, slows both receptor desensitization during sustained ATP application and receptor deactivation after ATP washout, and makes the receptor pore permeable to NMDG+, a large organic cation. Previously, we developed a Markov model based on the presence of one IVM binding site, which described some effects of IVM on rat P2X4R. Here we present two novel models, both with three IVM binding sites. The simpler one-layer model can reproduce many of the observed time series of evoked currents, but does not capture well the short time scales of activation, desensitization, and deactivation. A more complex two-layer model can reproduce the transient changes in desensitization observed upon IVM application, the significant increase in ATP-induced current amplitudes at low IVM concentrations, and the modest increase in the unitary conductance. In addition, the two-layer model suggests that this receptor can exist in a deeply inactivated state, not responsive to ATP, and that its desensitization rate can be altered by each of the three IVM binding sites. In summary, this study provides a detailed analysis of P2X4R kinetics and elucidates the orthosteric and allosteric mechanisms regulating its channel gating.

  19. The brain cytoplasmic RNA BC1 regulates dopamine D-2 receptor-mediated transmission in the striatum

    OpenAIRE

    Centonze, Diego; Rossi, Silvia; Napoli, Ilaria; Mercaldo, Valentina; Lacoux, Caroline; Ferrari, Francesca; Ciotti, Maria Teresa; De Chiara, Valentina; Prosperetti, Chiara; Maccarrone, Mauro; Fezza, Filomena; Calabresi, Paolo; Bernardi, Giorgio; Bagni, Claudia

    2007-01-01

    Dopamine D-2 receptor (D2DR)-mediated transmission in the striatum is remarkably flexible, and changes in its efficacy have been heavily implicated in a variety of physiological and pathological conditions. Although receptor-associated proteins are clearly involved in specific forms of synaptic plasticity, the molecular mechanisms regulating the sensitivity of D-2 receptors in this brain area are essentially obscure. We have studied the physiological responses of the D2DR stimulations in mice...

  20. Pregnenolone biosynthesis in C6-2B glioma cell mitochondria: regulation by a mitochondrial diazepam binding inhibitor receptor.

    OpenAIRE

    Papadopoulos, V; Guarneri, P; Kreuger, K E; Guidotti, A; Costa, E

    1992-01-01

    The C6-2B glioma cell line, rich in mitochondrial receptors that bind with high affinity to benzodiazepines, imidazopyridines, and isoquinolinecarboxamides (previously called peripheral-type benzodiazepine receptors), was investigated as a model to study the significance of the polypeptide diazepam binding inhibitor (DBI) and the putative DBI processing products on mitochondrial receptor-regulated steroidogenesis. DBI and its naturally occurring fragments have been found to be present in high...

  1. Homeostatic regulation of excitatory synapses on striatal medium spiny neurons expressing the D2 dopamine receptor.

    Science.gov (United States)

    Thibault, Dominic; Giguère, Nicolas; Loustalot, Fabien; Bourque, Marie-Josée; Ducrot, Charles; El Mestikawy, Salah; Trudeau, Louis-Éric

    2016-05-01

    Striatal medium spiny neurons (MSNs) are contacted by glutamatergic axon terminals originating from cortex, thalamus and other regions. The striatum is also innervated by dopaminergic (DAergic) terminals, some of which release glutamate as a co-transmitter. Despite evidence for functional DA release at birth in the striatum, the role of DA in the establishment of striatal circuitry is unclear. In light of recent work suggesting activity-dependent homeostatic regulation of glutamatergic terminals on MSNs expressing the D2 DA receptor (D2-MSNs), we used primary co-cultures to test the hypothesis that stimulation of DA and glutamate receptors regulates the homeostasis of glutamatergic synapses on MSNs. Co-culture of D2-MSNs with mesencephalic DA neurons or with cortical neurons produced an increase in spines and functional glutamate synapses expressing VGLUT2 or VGLUT1, respectively. The density of VGLUT2-positive terminals was reduced by the conditional knockout of this gene from DA neurons. In the presence of both mesencephalic and cortical neurons, the density of synapses reached the same total, compatible with the possibility of a homeostatic mechanism capping excitatory synaptic density. Blockade of D2 receptors increased the density of cortical and mesencephalic glutamatergic terminals, without changing MSN spine density or mEPSC frequency. Combined blockade of AMPA and NMDA glutamate receptors increased the density of cortical terminals and decreased that of mesencephalic VGLUT2-positive terminals, with no net change in total excitatory terminal density or in mEPSC frequency. These results suggest that DA and glutamate signaling regulate excitatory inputs to striatal D2-MSNs at both the pre- and postsynaptic level, under the influence of a homeostatic mechanism controlling functional output of the circuit.

  2. Regulation of ENaC in mice lacking renal insulin receptors in the collecting duct

    Science.gov (United States)

    Pavlov, Tengis S.; Ilatovskaya, Daria V.; Levchenko, Vladislav; Li, Lijun; Ecelbarger, Carolyn M.; Staruschenko, Alexander

    2013-01-01

    The epithelial sodium channel (ENaC) is one of the central effectors involved in regulation of salt and water homeostasis in the kidney. To study mechanisms of ENaC regulation, we generated knockout mice lacking the insulin receptor (InsR KO) specifically in the collecting duct principal cells. Single-channel analysis in freshly isolated split-open tubules demonstrated that the InsR-KO mice have significantly lower ENaC activity compared to their wild-type (C57BL/6J) littermates when animals were fed either normal or sodium-deficient diets. Immunohistochemical and Western blot assays demonstrated no significant changes in expression of ENaC subunits in InsR-KO mice compared to wild-type littermates. Insulin treatment caused greater ENaC activity in split-open tubules isolated from wild-type mice but did not have this effect in the InsR-KO mice. Thus, these results suggest that insulin increases ENaC activity via its own receptor affecting the channel open probability. To further determine the mechanism of the action of insulin on ENaC, we used mouse mpkCCDc14 principal cells. Insulin significantly augmented amiloride-sensitive transepithelial flux in these cells. Pretreatment of the mpkCCDc14 cells with phosphatidylinositol 3-kinase (LY294002; 10 μM) or mTOR (PP242; 100 nM) inhibitors precluded this effect. This study provides new information about the importance of insulin receptors expressed in collecting duct principal cells for ENaC activity.—Pavlov, T. S., Ilatovskaya, D. V., Levchenko, V., Li, L., Ecelbarger, C. M., Staruschenko, A. Regulation of ENaC in mice lacking renal insulin receptors in the collecting duct. PMID:23558339

  3. Towards an understanding of the evolution of the chorioallantoic placenta: steroid biosynthesis and steroid hormone signaling in the chorioallantoic membrane of an oviparous reptile.

    Science.gov (United States)

    Cruze, Lori; Kohno, Satomi; McCoy, Michael W; Guillette, Louis J

    2012-09-01

    Amniotes, mammals, reptiles, and birds form common extraembryonic membranes during development to perform essential functions, such as protection, nutrient transfer, gas exchange, and waste removal. Together with the maternal uterus, extraembryonic membranes of viviparous (live-bearing) amniotes develop as an endocrine placenta that synthesizes and responds to steroid hormones critical for development. The ability of these membranes to synthesize and respond to steroid hormone signaling has traditionally been considered an innovation of placental amniotes. However, our laboratory recently demonstrated that this ability extends to the chorioallantoic membrane (CAM) of an oviparous (egg-laying) amniote, the domestic chicken, and we hypothesized that steroidogenic extraembryonic membranes could be an evolutionarily conserved characteristic of all amniotes because of similarities in basic structure, function, and shared evolutionary ancestry. In this study, we examined steroid hormone synthesis and signaling in the CAM of another oviparous amniote, the American alligator (Alligator mississippiensis). We quantified mRNA expression of a steroidogenic factor involved in the regulation of steroidogenesis (NR5A1), the key steroidogenic enzymes involved in the synthesis of progestins (HSD3B1), androgens (CYP17A1), and estrogens (CYP19A1), and the receptors involved in the signaling of progestins (PR), androgens (AR), estrogens (ESR1 and ESR2), and glucocorticoids (GR). Furthermore, we performed protein immunolocalization for PR and ESR1. Collectively, our findings indicate that the alligator CAM has the capability to regulate, synthesize, and respond to steroid hormone signaling, thus, supporting our hypothesis that the extraembryonic membranes of Amniota share a unifying characteristic, that is, the ability to synthesize and respond to steroid hormones.

  4. Hypocretin/Orexin regulation of dopamine signaling and cocaine self-administration is mediated predominantly by hypocretin receptor 1.

    Science.gov (United States)

    Prince, Courtney D; Rau, Andrew R; Yorgason, Jordan T; España, Rodrigo A

    2015-01-21

    Extensive evidence suggests that the hypocretins/orexins influence cocaine reinforcement and dopamine signaling via actions at hypocretin receptor 1. By comparison, the involvement of hypocretin receptor 2 in reward and reinforcement processes has received relatively little attention. Thus, although there is some evidence that hypocretin receptor 2 regulates intake of some drugs of abuse, it is currently unclear to what extent hypocretin receptor 2 participates in the regulation of dopamine signaling or cocaine self-administration, particularly under high effort conditions. To address this, we examined the effects of hypocretin receptor 1, and/or hypocretin receptor 2 blockade on dopamine signaling and cocaine reinforcement. We used in vivo fast scan cyclic voltammetry to test the effects of hypocretin antagonists on dopamine signaling in the nucleus accumbens core and a progressive ratio schedule to examine the effects of these antagonists on cocaine self-administration. Results demonstrate that blockade of either hypocretin receptor 1 or both hypocretin receptor 1 and 2 significantly reduces the effects of cocaine on dopamine signaling and decreases the motivation to take cocaine. In contrast, blockade of hypocretin receptor 2 alone had no significant effects on dopamine signaling or self-administration. These findings suggest a differential involvement of the two hypocretin receptors, with hypocretin receptor 1 appearing to be more involved than hypocretin receptor 2 in the regulation of dopamine signaling and cocaine self-administration. When considered with the existing literature, these data support the hypothesis that hypocretins exert a permissive influence on dopamine signaling and motivated behavior via preferential actions on hypocretin receptor 1.

  5. P2Y2 and P2Y4 receptors regulate pancreatic Ca²+-activated K+ channels differently

    DEFF Research Database (Denmark)

    Klærke, Susanne Edeling Hede; Amstrup, Jan; Klærke, Dan Arne

    2005-01-01

    Extracellular ATP is an important regulator of transepithelial transport in a number of tissues. In pancreatic ducts, we have shown that ATP modulates epithelial K+ channels via purinergic receptors, most likely the P2Y2 and P2Y4 receptors, but the identity of the involved K+ channels was not cle...

  6. G protein-coupled receptor kinase 2 negatively regulates chemokine signaling at a level downstream from G protein subunits

    NARCIS (Netherlands)

    Jimenez-Sainz, MC; Murga, C; Kavelaars, A; Jurado-Pueyo, M; Krakstad, BF; Heijnen, CJ; Mayor, F; Aragay, AM

    The G protein-coupled receptor kinase 2 (GRK2) phosphorylates and desensitizes ligand-activated G protein-coupled-receptors. Here, evidence is shown for a novel role of GRK2 in regulating chemokine-mediated signals. The presence of increased levels of GRK2 in human embryonic kidney (HEK) 293 cells

  7. Mechanism of Ca2+/calmodulin-dependent kinase II regulation of AMPA receptor gating

    DEFF Research Database (Denmark)

    Kristensen, Anders Skov; Jenkins, Meagan A; Banke, Tue G

    2011-01-01

    The function, trafficking and synaptic signaling of AMPA receptors are tightly regulated by phosphorylation. Ca(2+)/calmodulin-dependent kinase II (CaMKII) phosphorylates the GluA1 AMPA receptor subunit at Ser831 to increase single-channel conductance. We show that CaMKII increases the conductanc...

  8. Neuroprotection of Sex Steroids

    Science.gov (United States)

    Liu, Mingyue; Kelley, Melissa H.; Herson, Paco S.; Hurn, Patricia D.

    2011-01-01

    Sex steroids are essential for reproduction and development in animals and humans, and sex steroids also play an important role in neuroprotection following brain injury. New data indicate that sex-specific responses to brain injury occur at the cellular and molecular levels. This review summarizes the current understanding of neuroprotection by sex steroids, particularly estrogen, androgen, and progesterone, based on both in vitro and in vivo studies. Better understanding of the role of sex steroids under physiological and pathological conditions will help us to develop novel effective therapeutic strategies for brain injury. PMID:20595940

  9. A Non-Nuclear Role of the Estrogen Receptor Alpha in the Regulation of Cell-Cell Interactions

    National Research Council Canada - National Science Library

    Darimont, Beatrice D

    2006-01-01

    .... The actions of estrogens are mediated by the estrogen receptors ERalpha and ERbeta. These hormone-regulated transcription factors translate the presence of estrogen into changes in gene expression...

  10. Carbachol does not down-regulate substance P receptors in pancreatic acini.

    Science.gov (United States)

    Patto, R J; Vinayek, R; Jensen, R T; Gardner, J D

    1992-01-01

    In a previous study, we found that first incubating guinea pig pancreatic acini with carbachol caused desensitization of the enzyme secretory response to cholecystokinin-octapeptide (CCK-8), bombesin, and carbachol but not that to substance P. This carbachol-induced desensitization could be accounted for by carbachol-induced down-regulation of receptors for CCK-8, bombesin, and carbachol. Although carbachol did not desensitize the enzyme secretory response to substance P, an effect of carbachol on substance P receptors was not examined. In the present study, in dispersed acini from guinea pig pancreas, substance P caused a twofold increase in amylase secretion. Stimulation was half-maximal at 0.7 nM and was maximal at 10 nM. Analysis of the ability of substance P to inhibit binding of 125I-substance P to substance P receptors indicated that acini possess a single class of receptors for substance P (Kd = 0.8 +/- 0.1 nM; Bmax = 1,037 +/- 145 fmol/mg of DNA). There was a close correlation between the relative potency with which substance P stimulated amylase secretion (0.7 nM) and the potency for inhibiting binding of 125I-substance P (Kd = 0.8 nM). First incubating pancreatic acini with carbachol did not alter either substance P-stimulated enzyme secretion or binding of 125I-substance P to substance P receptors, whereas in the same experiments, carbachol reduced binding of 125I-CCK-8 to cholecystokinin receptors by 50% and decreased in CCK-8-stimulated enzyme secretion by 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Differential regulation of. mu. , delta, kappa opioid receptors by Mn/sup + +/

    Energy Technology Data Exchange (ETDEWEB)

    Szuecs, M.; Oetting, G.M.; Coscia, C.J.

    1986-03-05

    Differential effects of Mn/sup + +/ on three opioid receptor subtypes of rat brain membranes were evaluated. Concentration dependency studies performed with 0.05-20 mM Mn/sup + +/ revealed that only the delta receptors are stimulated at any concentration. The binding of 1 nM /sup 3/H-DAGO was not stimulated by low concentrations (< 1mM) of Mn/sup + +/, and was significantly inhibited at higher concentrations (40% at 20 mM). 1 nM /sup 3/H-EKC (+100nM DAGO and 100nM DADLE) binding was inhibited by Mn/sup + +/ in the entire concentration range. While regulation of ..mu.. receptor binding did not change during postnatal development, delta and kappa binding displayed a pronounced developmental time-dependency. Kappa sites were hardly affected by Mn/sup + +/ at day 5, and adult levels of inhibition were reached only after the third week postnatal. In contrast, 1 nM /sup 3/H-DADLE (+10nM DAGO) binding was most sensitive to Mn/sup + +/ on day 5 after birth (100% stimulation with 5-20 mM). The ED/sub 50/ of Mn/sup + +/ stimulation was unchanged during maturation. These immature delta sites displayed a similar extent of Mn/sup + +/ reversal of Gpp(NH)p inhibition as seen in microsomes, which represent a good model of N/sub i/-uncoupled receptors. These data suggest that ..mu.., delta and kappa receptors are differently coupled to N/sub i/. Moreover, a second divalent cation binding site, in addition to that on N/sub i/ might exist for delta receptors.

  12. Selective androgen receptor modulators (SARMs) negatively regulate triple-negative breast cancer growth and epithelial:mesenchymal stem cell signaling.

    Science.gov (United States)

    Narayanan, Ramesh; Ahn, Sunjoo; Cheney, Misty D; Yepuru, Muralimohan; Miller, Duane D; Steiner, Mitchell S; Dalton, James T

    2014-01-01

    The androgen receptor (AR) is the most highly expressed steroid receptor in breast cancer with 75-95% of estrogen receptor (ER)-positive and 40-70% of ER-negative breast cancers expressing AR. Though historically breast cancers were treated with steroidal androgens, their use fell from favor because of their virilizing side effects and the emergence of tamoxifen. Nonsteroidal, tissue selective androgen receptor modulators (SARMs) may provide a novel targeted approach to exploit the therapeutic benefits of androgen therapy in breast cancer. Since MDA-MB-453 triple-negative breast cancer cells express mutated AR, PTEN, and p53, MDA-MB-231 triple-negative breast cancer cells stably expressing wildtype AR (MDA-MB-231-AR) were used to evaluate the in vitro and in vivo anti-proliferative effects of SARMs. Microarray analysis and epithelial:mesenchymal stem cell (MSC) co-culture signaling studies were performed to understand the mechanisms of action. Dihydrotestosterone and SARMs, but not bicalutamide, inhibited the proliferation of MDA-MB-231-AR. The SARMs reduced the MDA-MB-231-AR tumor growth and tumor weight by greater than 90%, compared to vehicle-treated tumors. SARM treatment inhibited the intratumoral expression of genes and pathways that promote breast cancer development through its actions on the AR. SARM treatment also inhibited the metastasis-promoting paracrine factors, IL6 and MMP13, and subsequent migration and invasion of epithelial:MSC co-cultures. 1. AR stimulation inhibits paracrine factors that are important for MSC interactions and breast cancer invasion and metastasis. 2. SARMs may provide promise as novel targeted therapies to treat AR-positive triple-negative breast cancer.

  13. Selective androgen receptor modulators (SARMs negatively regulate triple-negative breast cancer growth and epithelial:mesenchymal stem cell signaling.

    Directory of Open Access Journals (Sweden)

    Ramesh Narayanan

    Full Text Available The androgen receptor (AR is the most highly expressed steroid receptor in breast cancer with 75-95% of estrogen receptor (ER-positive and 40-70% of ER-negative breast cancers expressing AR. Though historically breast cancers were treated with steroidal androgens, their use fell from favor because of their virilizing side effects and the emergence of tamoxifen. Nonsteroidal, tissue selective androgen receptor modulators (SARMs may provide a novel targeted approach to exploit the therapeutic benefits of androgen therapy in breast cancer.Since MDA-MB-453 triple-negative breast cancer cells express mutated AR, PTEN, and p53, MDA-MB-231 triple-negative breast cancer cells stably expressing wildtype AR (MDA-MB-231-AR were used to evaluate the in vitro and in vivo anti-proliferative effects of SARMs. Microarray analysis and epithelial:mesenchymal stem cell (MSC co-culture signaling studies were performed to understand the mechanisms of action.Dihydrotestosterone and SARMs, but not bicalutamide, inhibited the proliferation of MDA-MB-231-AR. The SARMs reduced the MDA-MB-231-AR tumor growth and tumor weight by greater than 90%, compared to vehicle-treated tumors. SARM treatment inhibited the intratumoral expression of genes and pathways that promote breast cancer development through its actions on the AR. SARM treatment also inhibited the metastasis-promoting paracrine factors, IL6 and MMP13, and subsequent migration and invasion of epithelial:MSC co-cultures.1. AR stimulation inhibits paracrine factors that are important for MSC interactions and breast cancer invasion and metastasis. 2. SARMs may provide promise as novel targeted therapies to treat AR-positive triple-negative breast cancer.

  14. Randomized controlled trial of toremifene 120 mg compared with exemestane 25 mg after prior treatment with a non-steroidal aromatase inhibitor in postmenopausal women with hormone receptor-positive metastatic breast cancer.

    Science.gov (United States)

    Yamamoto, Yutaka; Ishikawa, Takashi; Hozumi, Yasuo; Ikeda, Masahiko; Iwata, Hiroji; Yamashita, Hiroko; Toyama, Tatsuya; Chishima, Takashi; Saji, Shigehira; Yamamoto-Ibusuki, Mutsuko; Iwase, Hirotaka

    2013-05-16

    After the failure of a non-steroidal aromatase inhibitor (nsAI) for postmenopausal patients with metastatic breast cancer (mBC), it is unclear which of various kinds of endocrine therapy is the most appropriate. A randomized controlled trial was performed to compare the efficacy and safety of daily toremifene 120 mg (TOR120), a selective estrogen receptor modulator, and exemestane 25 mg (EXE), a steroidal aromatase inhibitor. The primary end point was the clinical benefit rate (CBR). The secondary end points were objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and toxicity. Initially, a total of 91 women was registered in the study and randomly assigned to either TOR120 (n = 46) or EXE (n = 45) from October 2008 to November 2011. Three of the 46 patients in the TOR120 arm were not received treatment, 2 patients having withdrawn from the trial by their preference and one having been dropped due to administration of another SERM. When analyzed after a median observation period of 16.9 months, the intention-to-treat analysis showed that there were no statistical difference between TOR120 (N = 46) and EXE (n = 45) in terms of CBR (41.3% vs. 26.7%; P = 0.14), ORR (10.8% vs. 2.2%; P = 0.083), and OS (Hazard ratio, 0.60; P = 0.22). The PFS of TOR120 was longer than that of EXE, the difference being statistically significant (Hazard ratio, 0.61, P = 0.045). The results in treatment-received cohort (N = 88) were similar to those in ITT cohort. Both treatments were well-tolerated with no severe adverse events, although the treatment of 3 of 43 women administered TOR120 was stopped after a few days because of nausea, general fatigue, hot flush and night sweating. TOR120, as a subsequent endocrine therapy for mBC patients who failed non-steroidal AI treatment, could potentially be more beneficial than EXE. UMIN000001841.

  15. Randomized controlled trial of toremifene 120 mg compared with exemestane 25 mg after prior treatment with a non-steroidal aromatase inhibitor in postmenopausal women with hormone receptor-positive metastatic breast cancer

    International Nuclear Information System (INIS)

    Yamamoto, Yutaka; Yamamoto-Ibusuki, Mutsuko; Iwase, Hirotaka; Ishikawa, Takashi; Hozumi, Yasuo; Ikeda, Masahiko; Iwata, Hiroji; Yamashita, Hiroko; Toyama, Tatsuya; Chishima, Takashi; Saji, Shigehira

    2013-01-01

    After the failure of a non-steroidal aromatase inhibitor (nsAI) for postmenopausal patients with metastatic breast cancer (mBC), it is unclear which of various kinds of endocrine therapy is the most appropriate. A randomized controlled trial was performed to compare the efficacy and safety of daily toremifene 120 mg (TOR120), a selective estrogen receptor modulator, and exemestane 25 mg (EXE), a steroidal aromatase inhibitor. The primary end point was the clinical benefit rate (CBR). The secondary end points were objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and toxicity. Initially, a total of 91 women was registered in the study and randomly assigned to either TOR120 (n = 46) or EXE (n = 45) from October 2008 to November 2011. Three of the 46 patients in the TOR120 arm were not received treatment, 2 patients having withdrawn from the trial by their preference and one having been dropped due to administration of another SERM. When analyzed after a median observation period of 16.9 months, the intention-to-treat analysis showed that there were no statistical difference between TOR120 (N = 46) and EXE (n = 45) in terms of CBR (41.3% vs. 26.7%; P = 0.14), ORR (10.8% vs. 2.2%; P = 0.083), and OS (Hazard ratio, 0.60; P = 0.22). The PFS of TOR120 was longer than that of EXE, the difference being statistically significant (Hazard ratio, 0.61, P = 0.045). The results in treatment-received cohort (N = 88) were similar to those in ITT cohort. Both treatments were well-tolerated with no severe adverse events, although the treatment of 3 of 43 women administered TOR120 was stopped after a few days because of nausea, general fatigue, hot flush and night sweating. TOR120, as a subsequent endocrine therapy for mBC patients who failed non-steroidal AI treatment, could potentially be more beneficial than EXE. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function

  16. Post-translational regulation of P2X receptor channels: modulation by phospholipids

    Directory of Open Access Journals (Sweden)

    Louis-Philippe eBernier

    2013-11-01

    Full Text Available P2X receptor channels mediate fast excitatory signaling by ATP and play major roles in sensory transduction, neuro-immune communication and inflammatory response. P2X receptors constitute a gene family of calcium-permeable ATP-gated cation channels therefore the regulation of P2X signaling is critical for both membrane potential and intracellular calcium homeostasis. Phosphoinositides (PIPn are anionic signaling phospholipids that act as functional regulators of many types of ion channels. Direct PIPn binding was demonstrated for several ligand- or voltage-gated ion channels, however no generic motif emerged to accurately predict lipid-protein binding sites. This review presents what is currently known about the modulation of the different P2X subtypes by phospholipids and about critical determinants underlying their sensitivity to PIPn levels in the plasma membrane.All functional mammalian P2X subtypes tested, with the notable exception of P2X5, have been shown to be positively modulated by PIPn, i.e. homomeric P2X1, P2X2, P2X3, P2X4, and P2X7, as well as heteromeric P2X1/5 and P2X2/3 receptors. Based on various results reported on the aforementioned subtypes including mutagenesis of the prototypical PIPn-sensitive P2X4 and PIPn-insensitive P2X5 receptor subtypes, an increasing amount of functional, biochemical and structural evidence converges on the modulatory role of a short polybasic domain located in the proximal C-terminus of P2X subunits. This linear motif, semi-conserved in the P2X family, seems necessary and sufficient for encoding direct modulation of ATP-gated channels by PIPn. Furthermore, the physiological impact of the regulation of ionotropic purinergic responses by phospholipids on pain pathways was recently revealed in the context of native crosstalks between phospholipase C-linked metabotropic receptors and P2X receptor channels in DRG sensory neurons and microglia.

  17. The FKBP51 Glucocorticoid Receptor Co-Chaperone: Regulation, Function, and Implications in Health and Disease.

    Science.gov (United States)

    Fries, Gabriel R; Gassen, Nils C; Rein, Theo

    2017-12-05

    Among the chaperones and co-chaperones regulating the glucocorticoid receptor (GR), FK506 binding protein (FKBP) 51 is the most intensely investigated across different disciplines. This review provides an update on the role of the different co-chaperones of Hsp70 and Hsp90 in the regulation of GR function. The development leading to the focus on FKBP51 is outlined. Further, a survey of the vast literature on the mechanism and function of FKBP51 is provided. This includes its structure and biochemical function, its regulation on different levels-transcription, post-transcription, and post-translation-and its function in signaling pathways. The evidence portraying FKBP51 as a scaffolding protein organizing protein complexes rather than a chaperone contributing to the folding of individual proteins is collated. Finally, FKBP51's involvement in physiology and disease is outlined, and the promising efforts in developing drugs targeting FKBP51 are discussed.

  18. The β-Arrestins: Multifunctional Regulators of G Protein-coupled Receptors.

    Science.gov (United States)

    Smith, Jeffrey S; Rajagopal, Sudarshan

    2016-04-22

    The β-arrestins (βarrs) are versatile, multifunctional adapter proteins that are best known for their ability to desensitize G protein-coupled receptors (GPCRs), but also regulate a diverse array of cellular functions. To signal in such a complex fashion, βarrs adopt multiple conformations and are regulated at multiple levels to differentially activate downstream pathways. Recent structural studies have demonstrated that βarrs have a conserved structure and activation mechanism, with plasticity of their structural fold, allowing them to adopt a wide array of conformations. Novel roles for βarrs continue to be identified, demonstrating the importance of these dynamic regulators of cellular signaling. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Liver X Receptor (LXR) activation negatively regulates visfatin expression in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Mayi, Therese Hervee; Rigamonti, Elena [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Pattou, Francois [Univ Lille Nord de France, F-59000 Lille (France); Department of Endocrine Surgery, University Hospital, Lille (France); U859 Biotherapies for Diabetes, INSERM, Lille (France); Staels, Bart, E-mail: bart.staels@pasteur-lille.fr [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Chinetti-Gbaguidi, Giulia [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France)

    2011-01-07

    Research highlights: {yields} Synthetic LXR ligands decreased visfatin expression in human macrophages. {yields} LXR activation leads to a modest and transient decrease of NAD{sup +} concentration. {yields} LXR activation decreased PPAR{gamma}-induced visfatin in human macrophages. -- Abstract: Adipose tissue macrophages (ATM) are the major source of visfatin, a visceral fat adipokine upregulated during obesity. Also known to play a role in B cell differentiation (pre-B cell colony-enhancing factor (PBEF)) and NAD biosynthesis (nicotinamide phosphoribosyl transferase (NAMPT)), visfatin has been suggested to play a role in inflammation. Liver X Receptor (LXR) and Peroxisome Proliferator-Activated Receptor (PPAR){gamma} are nuclear receptors expressed in macrophages controlling the inflammatory response. Recently, we reported visfatin as a PPAR{gamma} target gene in human macrophages. In this study, we examined whether LXR regulates macrophage visfatin expression. Synthetic LXR ligands decreased visfatin gene expression in a LXR-dependent manner in human and murine macrophages. The decrease of visfatin mRNA was paralleled by a decrease of protein secretion. Consequently, a modest and transient decrease of NAD{sup +} concentration was observed. Interestingly, LXR activation decreased the PPAR{gamma}-induced visfatin gene and protein secretion in human macrophages. Our results identify visfatin as a gene oppositely regulated by the LXR and PPAR{gamma} pathways in human macrophages.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

    The specific binding of iodinated epidermal growth factor ([ 125 I]iodo-EGF) to membranes prepared from the mammary glands and spontaneous breast tumors of euthyroid and hypothyroid mice was measured in order to determine whether thyroid hormones regulate the EGF receptor levels in vivo. Membranes from hypothyroid mammary glands of mice at various developmental ages bound 50-65% less EGF than those of age-matched euthyroid controls. Treatment of hypothyroid mice with L-T4 before killing restored binding to the euthyroid control level. Spontaneous breast tumors arising in hypothyroid mice also bound 30-40% less EGF than tumors from euthyroid animals even after in vitro desaturation of the membranes of endogenous growth factors with 3 M MgCl2 treatment. The decrease in binding in hypothyroid membranes was due to a decrease in the number of binding sites, not to a change in affinity of the growth factor for its receptor, as determined by Scatchard analysis of the binding data. Both euthyroid and hypothyroid membranes bound EGF primarily to a single class of high affinity sites [dissociation constant (Kd) = 0.7-1.8 nM]. Euthyroid membranes bound 28.4 +/- (SE) 0.6 fmol/mg protein, whereas hypothyroid membranes bound 15.5 +/- 1.0 fmol/mg protein. These data indicate that EGF receptor levels in normal mammary glands and spontaneous breast tumors in mice are subject to regulation by thyroid status

  1. Rab5 regulates internalisation of P2X4 receptors and potentiation by ivermectin.

    Science.gov (United States)

    Stokes, Leanne

    2013-03-01

    The P2X4 receptor is an ATP-gated ion channel expressed in neurons, endothelia and immune cells. Plasma membrane expression of P2X4 is regulated by dynamin-dependent endocytosis, and this study identifies a Rab5-dependent pathway of receptor internalisation. Expression of Rab5 constructs altered the distribution of P2X4 in HEK-293 cells, and both constitutive internalisation and agonist-induced desensitisation of P2X4 were increased by co-expression of wild-type Rab5 or constitutively active Rab5 (Q79L). Expression of inactive dynamin K44A and Rab5 S34N constructs abolished agonist-induced desensitisation, suggesting internalisation as the underlying mechanism. Blocking P2X4 internalisation in this way also abolished potentiation of ATP-induced currents by the allosteric modulator ivermectin. This suggests that the dynamin-Rab5 internalisation pathway is essential for the ivermectin potentiation effect. In agreement with this hypothesis, the co-expression of wild-type dynamin, wild-type Rab5 or active Rab5 (Q79L) could increase the potentiation of the ATP-induced P2X4 response by ivermectin. These findings highlight Rab5 GTPase as a key regulator of P2X4 receptor cell surface expression and internalisation.

  2. Rapamycin down-regulates LDL-receptor expression independently of SREBP-2

    International Nuclear Information System (INIS)

    Sharpe, Laura J.; Brown, Andrew J.

    2008-01-01

    As a key regulator of cholesterol homeostasis, sterol-regulatory element binding protein-2 (SREBP-2) up-regulates expression of genes involved in cholesterol synthesis (e.g., 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) Reductase) and uptake (the low density lipoprotein (LDL)-receptor). Previously, we showed that Akt, a critical kinase in cell growth and proliferation, contributes to SREBP-2 activation. However, the specific Akt target involved is unknown. A potential candidate is the mammalian target of rapamycin, mTOR. Rapamycin can cause hyperlipidaemia clinically, and we hypothesised that this may be mediated via an effect of mTOR on SREBP-2. Herein, we found that SREBP-2 activation and HMG-CoA Reductase gene expression were unaffected by rapamycin treatment. However, LDL-receptor gene expression was decreased by rapamycin, suggesting that this may contribute to the hyperlipidaemia observed in rapamycin-treated patients. Rapamycin did not affect mRNA stability, so the decrease in LDL-receptor gene expression is likely to be occurring at the transcriptional level, although independently of SREBP-2

  3. Micromolar-Affinity Benzodiazepine Receptors Regulate Voltage-Sensitive Calcium Channels in Nerve Terminal Preparations

    Science.gov (United States)

    Taft, William C.; Delorenzo, Robert J.

    1984-05-01

    Benzodiazepines in micromolar concentrations significantly inhibit depolarization-sensitive Ca2+ uptake in intact nerve-terminal preparations. Benzodiazepine inhibition of Ca2+ uptake is concentration dependent and stereospecific. Micromolar-affinity benzodiazepine receptors have been identified and characterized in brain membrane and shown to be distinct from nanomolar-affinity benzodiazepine receptors. Evidence is presented that micromolar, and not nanomolar, benzodiazepine binding sites mediate benzodiazepine inhibition of Ca2+ uptake. Irreversible binding to micromolar benzodiazepine binding sites also irreversibly blocked depolarization-dependent Ca2+ uptake in synaptosomes, indicating that these compounds may represent a useful marker for identifying the molecular components of Ca2+ channels in brain. Characterization of benzodiazepine inhibition of Ca2+ uptake demonstrates that these drugs function as Ca2+ channel antagonists, because benzodiazepines effectively blocked voltage-sensitive Ca2+ uptake inhibited by Mn2+, Co2+, verapamil, nitrendipine, and nimodipine. These results indicate that micromolar benzodiazepine binding sites regulate voltage-sensitive Ca2+ channels in brain membrane and suggest that some of the neuronal stabilizing effects of micromolar benzodiazepine receptors may be mediated by the regulation of Ca2+ conductance.

  4. Dopamine D2L receptor-interacting proteins regulate dopaminergic signaling

    Directory of Open Access Journals (Sweden)

    Norifumi Shioda

    2017-10-01

    Full Text Available Dopamine receptor family proteins include seven transmembrane and trimeric GTP-binding protein-coupled receptors (GPCRs. Among them, the dopamine D2 receptor (D2R is most extensively studied. All clinically used antipsychotic drugs serve as D2R antagonists in the mesolimbic dopamine system, and their ability to block D2R signaling is positively correlated with antipsychotic efficiency. Human genetic studies also show a significant association of DRD2 polymorphisms with disorders including schizophrenia and Parkinson's disease. D2R exists as two alternatively spliced isoforms, the long isoform (D2LR and the short isoform (D2SR, which differ in a 29-amino acid (AA insert in the third cytoplasmic loop. Importantly, previous reports demonstrate functional diversity between the two isoforms in humans. In this review, we focus on binding proteins that specifically interact with the D2LR 29AA insert. We discuss how D2R activities are mediated not only by heterotrimeric G proteins but by D2LR-interacting proteins, which in part regulate diverse D2R activities. Keywords: Dopamine D2L receptor, Antipsychotic drugs, DRD2 polymorphisms, Alternatively spliced isoforms, D2LR-interacting proteins

  5. Region-specific proteolysis differentially regulates type 1 inositol 1,4,5-trisphosphate receptor activity.

    Science.gov (United States)

    Wang, Liwei; Wagner, Larry E; Alzayady, Kamil J; Yule, David I

    2017-07-14

    The inositol 1,4,5 trisphosphate receptor (IP 3 R) is an intracellular Ca 2+ release channel expressed predominately on the membranes of the endoplasmic reticulum. IP 3 R1 can be cleaved by caspase or calpain into at least two receptor fragments. However, the functional consequences of receptor fragmentation are poorly understood. Our previous work has demonstrated that IP 3 R1 channels, formed following either enzymatic fragmentation or expression of the corresponding complementary polypeptide chains, retain tetrameric architecture and are still activated by IP 3 binding despite the loss of peptide continuity. In this study, we demonstrate that region-specific receptor fragmentation modifies channel regulation. Specifically, the agonist-evoked temporal Ca 2+ release profile and protein kinase A modulation of Ca 2+ release are markedly altered. Moreover, we also demonstrate that activation of fragmented IP 3 R1 can result in a distinct functional outcome. Our work suggests that proteolysis of IP 3 R1 may represent a novel form of modulation of IP 3 R1 channel function and increases the repertoire of Ca 2+ signals achievable through this channel. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. The Cell Surface Estrogen Receptor, G Protein- Coupled Receptor 30 (GPR30, is Markedly Down Regulated During Breast Tumorigenesis

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    Indira Poola

    2008-01-01

    Full Text Available Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity. Deregulation of the events mediated by GPR30 could contribute to tumorigenesis.Methods: To understand the role of GPR30 in the deregulation of estrogen signaling processes during breast carcinogenesis, we have undertaken this study to investigate its expression at mRNA levels in tumor tissues and their matched normal tissues. We compared its expression at mRNA levels by RT quantitative real-time PCR relative to GAPDH in ERα”—positive (n = 54 and ERα”—negative (n = 45 breast cancer tissues to their matched normal tissues.Results: We report here, for the first time, that GPR30 mRNA levels were significantly down-regulated in cancer tissues in comparison with their matched normal tissues (p 0.0001 by two sided paired t-test. The GPR30 expression levels were significantly lower in tumor tissues from patients (n = 29 who had lymph node metastasis in comparison with tumors from patients (n = 53 who were negative for lymph node metastasis (two sample t-test, p 0.02, but no association was found with ERα, PR and other tumor characteristics.Conclusions: Down-regulation of GPR30 could contribute to breast tumorigenesis and lymph node metastasis.

  7. Receptor-targeted metalloradiopharmaceuticals. Final technical report

    International Nuclear Information System (INIS)

    Green, Mark A.

    2000-01-01

    Copper (II) and platinum (II) coordination complexes were prepared and characterized. These complexes were designed to afford structural homology with steroidal and non-steroidal estrogens for possible use as receptor-targeted radiopharmaceuticals. While weak affinity for the estrogen receptor was detectable, none would appear to have sufficient receptor-affinity for estrogen-receptor-targeted imaging or therapy

  8. N-wasp is essential for the negative regulation of B cell receptor signaling.

    Directory of Open Access Journals (Sweden)

    Chaohong Liu

    2013-11-01

    Full Text Available Negative regulation of receptor signaling is essential for controlling cell activation and differentiation. In B-lymphocytes, the down-regulation of B-cell antigen receptor (BCR signaling is critical for suppressing the activation of self-reactive B cells; however, the mechanism underlying the negative regulation of signaling remains elusive. Using genetically manipulated mouse models and total internal reflection fluorescence microscopy, we demonstrate that neuronal Wiskott-Aldrich syndrome protein (N-WASP, which is coexpressed with WASP in all immune cells, is a critical negative regulator of B-cell signaling. B-cell-specific N-WASP gene deletion causes enhanced and prolonged BCR signaling and elevated levels of autoantibodies in the mouse serum. The increased signaling in N-WASP knockout B cells is concurrent with increased accumulation of F-actin at the B-cell surface, enhanced B-cell spreading on the antigen-presenting membrane, delayed B-cell contraction, inhibition in the merger of signaling active BCR microclusters into signaling inactive central clusters, and a blockage of BCR internalization. Upon BCR activation, WASP is activated first, followed by N-WASP in mouse and human primary B cells. The activation of N-WASP is suppressed by Bruton's tyrosine kinase-induced WASP activation, and is restored by the activation of SH2 domain-containing inositol 5-phosphatase that inhibits WASP activation. Our results reveal a new mechanism for the negative regulation of BCR signaling and broadly suggest an actin-mediated mechanism for signaling down-regulation.

  9. X-ray structures of progesterone receptor ligand binding domain in its agonist state reveal differing mechanisms for mixed profiles of 11beta-substituted steroids.

    NARCIS (Netherlands)

    Lusher, S.J.; Raaijmakers, H.C.A.; Vu-Pham, D.; Kazemier, B.; Bosch, R.; McGuire, R.; Azevedo, R.; Hamersma, H.; Dechering, K.; Oubrie, A.; Duin, M. van; Vlieg, J. de

    2012-01-01

    We present here the x-ray structures of the progesterone receptor (PR) in complex with two mixed profile PR modulators whose functional activity results from two differing molecular mechanisms. The structure of Asoprisnil bound to the agonist state of PR demonstrates the contribution of the ligand

  10. Cyproterone acetate enhances TRAIL-induced androgen-independent prostate cancer cell apoptosis via up-regulation of death receptor 5.

    Science.gov (United States)